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(2023)Migreeni on toistuvia päänsärkykohtauksia aiheuttava neurologinen sairaus, jonka esiintyvyys on hyvin laajaa – Suomessa migreeniä sairastaa lähes joka kymmenes väestöstä. Migreenin puhkeamisella on tutkimusten mukaan vahva yhteys genetiikkaan, ja migreenin hoidossa käytettyjen lääkevalmisteiden metabolia on oleellisesti sidoksissa geeneihin. Farmakogenetiikka tutkii tieteenalana, miten perintötekijät vaikuttavat lääkeaineiden aineenvaihduntaan ja niistä syntyvään lääkevasteeseen. Tässä tutkimuksessa tarkasteltiin migreenin estolääkkeenä käytetyn trisyklisen masennuslääkkeen, amitriptyliinin, metaboliassa esiintyviä mahdollisia geneettisiä eroja itä- ja länsisuomalaisten välillä. Tutkimus toteutettiin tarkastelemalla yli 10 000 Terveystalon Biopankin biopankkinäytettä, joista määritettiin kolmen CYP-entsyymin (CYP2C9, CYP2C19, CYP2D6) fenotyyppien esiintyvyys itä- ja länsisuomalaisissa. Tutkimustulosten mukaan eroavaisuudet fenotyyppien esiintyvyydessä itä- ja länsisuomalaisten välillä olivat maltillisia. Amitriptyliinin metaboliassa erityisen oleellisen CYP2C19 geenin osalta sekä normaalia hitaampi että hidas metabolia olivat yleisempiä idässä kuin lännessä. Hitaan metabolian riskinä on tavallista suuremmat plasmapitoisuudet ja siten lisääntyneet lääkevalmisteen haittavaikutusriskit. Näin ollen amitriptyliiniä tulisi hitailla metaboloijilla käyttää harkiten, aloittaa vaihtoehtoinen lääkitys tai pienentää aloitusannosta puoleen tavanomaisesta. Oikean annostuksen löytämisessä tulisi hyödyntää laboratorion pitoisuusmäärityskokeita. Lisäksi farmakogeneettisillä testeillä voitaisiin havaita mahdollinen geenien tarkempi polymorfia, ja siten varmistaa sekä turvallinen että tehokas yksilöllinen lääkehoito.
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(2023)Oncolytic adenoviruses are a new cancer treatment platform which aims to eliminate cancer through direct lysis of cancer cells by viral replication and the activation of the immune system by the release of tumor antigens upon oncolysis. In the PeptiCRAd technology, the activation of an anti-cancer immune response is enhanced by the addition of poly-lysine modified cancer peptides, where the antigen presentation to the immune system is improved in comparison to plain oncolytic viruses. PeptiCRAd complexes have been assumed to form solely by electrostatic interactions, but the thermodynamic profiles and mechanisms involved in the complexation have not been previously addressed. Thus, by adding isothermal titration calorimetry as part of the analysis repertoire provides valuable information of the characteristics of PeptiCRAd complexes. In this study, the applicability of isothermal titration calorimetry in PeptiCRAd complexation analyses was evaluated based on initial peptide-to-virus and virus-to-peptide titrations, and a method of analysis was created for the thermodynamics of the interactions of the complex. Optimization of the experimental method (i.e., titration protocol) and the data analysis (i.e., calculation models) remains inconclusive for quantitative analysis as data obtained from the measurements was mainly of bad quality, thus requiring further optimization to obtain reliable data. However, using surface plasmon resonance as an already established method for poly-lysine peptide-virus interaction studies gave robust data and can be used as a base or guideline to further develop isothermal titration calorimetry analyses for characterizing PeptiCRAd complexes. Although isothermal titration calorimetry measurements were unsuccessful for quantification purposes, it was possible to qualitate the mechanisms of PeptiCRAd complexation for four different peptides with fair confidence. The peptides showed low heats of binding, and positive and negative cooperative binding in ionic and non-ionic solutions, respectively. Based on this, the binding of peptides in PeptiCRAd complexes was determined to be driven by hydrophobic inter-peptide interactions on the virus surface, although an electrostatic attraction is indeed present at the virus-peptide interface, initiating the binding event. Also, improvements to the titration protocol for PeptiCRAd analyses with isothermal titration calorimetry are suggested for further optimizations in the future to conclusively determine the applicability of the isothermal titration calorimetry technique for characterizing peptide-virus interactions of PeptiCRAd complexes.
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(2023)Orexin receptors have gained more attention due to increased knowledge of their physiological significance. The successful development of orexin receptor antagonists treating insomnia has enlarged the scope of research leading to an interest in developing small molecule agonists that have drug-like properties and induce activation in the orexinergic system. Transforming this idea into reality has remained an unaccomplished challenge. In this work, molecular mechanism of activation in orexin receptor type 2 is studied by conducting molecular dynamics simulations after capturing coordinates of active and inactive state crystal structures. The crystal structure coordinates define the starting pose for the protein and the ligand in the simulations. Preliminary steps prior to simulation include building the surrounding system and model building in which homology modeling is employed to reconstruct missing loops. A 100-nanosecond simulation is executed for both models. Active and inactive state models display stable binding event characteristics when examining the coordinate changes of every atom during the simulation. No major conformational changes are observed. The most congruent feature relative to the literature is the difference in the interactive role of residue Q3x32 between the simulations. The agonist forms two consistent hydrogen bonds with the upward-shifted Q3x32 while an inactive downward-facing version is observed in the antagonist model. Some residues present unexpected features omitting comparative functions of literature, which along with general inconsistency of protein-ligand contacts undermine the reliability of models heavily. The simulations conducted need to be extended to produce a hypothesis for the activation mechanism because of the defects around simulation protocols and the low quantity of simulation runs.
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(2022)Coronary heart disease is a number one killer in westernized countries and the costs from it will continue to grow in the future. It is caused by atherosclerosis, build-up of plaque and chronic inflammation in the arteries of heart, and endogenous lipoproteins have a special role in its development. Among other atheroprotective properties, High density lipoproteins (HDL) have a role in intrinsic mechanism of the reverse cholesterol transport (RCT), of gathering and removing excess cholesterol from peripheral tissues. There have been several HDL raising strategies in the past for the treatment of atherosclerosis, but their success has been modest. Synthetic HDL (sHDL), comprising of various types of phospholipids and proteins or peptides, have been developed to mimic the properties of endogenous HDL. Despite some success in animal studies, failures in clinical studies have turned the focus on the HDL’s interaction with a specific enzyme lecithin:cholesterol acyl transferase (LCAT), responsible for cholesterol esterification, a key step in RCT. ApoA-I, the most abundant protein component of HDL, acts as LCAT cofactor in cholesterol esterification, and many LCAT activating peptides have been developed to mimic the features of apoA-I. The molecular level understanding behind LCAT activation is however still foggy. During enzymatic activation, LCAT goes through conformational changes specific regions, which are generated by interactions with apoA-I or synthetic peptides. These mechanisms have been studied widely with molecular dynamic simulations, in vitro experiments, and imaging. In this study, we investigated 22A (PVLDLFRELLNELLEALKQKLK), apoA-I mimetic peptide known for its as good LCAT activation potency as apoA-I, and four variations of it (21A, 22A-P, 22A-K22Q, and 22A-R7Q), and combined them with phospholipid DPPC to create sHDL nanodiscs by thermal cycling method. We examined the effect of small changes in peptide sequence on LCAT-sHDL binding strength with quartz crystal microbalance with dissipation (QCM-D). The interest was to further test the suitability of thermal cycling method on nanodisc assembly, test the binding strengths against the hypothesis of the role of salt-bridge forming amino acids R7 and K22 in peptide dimerization and its effect on LCAT binding and activation, and to see if QCM could act as a suitable method for the research of sHDL-LCAT interactions. All peptides formed similar sized sHDL particles with diameter of ~10 nm with thermal cycling method. As expected, the LCAT binding tendency of 22A-sHDL was highest, about double compared to four other peptide nanodiscs with almost identical results. The QCM results suggest that binding tendency between LCAT and sHDL is affected by small, one amino acid change in peptide sequence, but it does not necessarily have a big impact on LCAT’s esterification activity, but based on this experiment alone, we cannot make any further conclusions. Electron microscopy revealed exceptional breakdown of 21A-sHDL incubated with LCAT compared to 22A-sHDL. This phenomenon could indicate high lipolytic rate of LCAT but needs further investigation. There were some challenges with the measurement parameters in the beginning, and the variability between parallel measurements with QCM-D was high, which cause a little doubt about the method’s suitability for these kinds of precise measurements. More research for revealing the molecular mechanism behind LCAT activation is needed for the development of more effective treatments.
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(2022)Safety of pharmacotherapies is an essential part of patient safety that promotes and supports rational use of medicines. Safety of pharmacotherapies can be divided into two areas; Drug safety and medication safety. Drug safety refers to the safety of a medicine as a product, such as the pharmacological properties and the quality of the manufacturing process. Medication safety ensures the safety of a drug therapy process preventing patients from harm during the course of using medicines. Significant inconsistencies have been identified in the terminology related to drug and medication safety. Challenges to terminology are posed by varying synonyms, ambiguity or overlap of concepts, and misclassification of events in the scientific literature. The primary objective of this study was to scope recent peer-reviewed literature related to the drug safety and medication safety terminology from the period pf 2010-2022. A secondary objective was to examine the relationship between the concepts as presented in the literature, including overlaps and differences between the terms. The study was conducted as a scoping review by using Scopus and Ovid Medline databases. The literature search covered studies from January 2010 to January 2022. The search was conducted by using the following phrases; "("medication safety" OR "drug safety" OR pharmacovigilance) W/5 (definition* OR terminology*)" in Scopus and "("medication safety" OR "drug safety" OR pharmacovigilance) ADJ/6 (definition* OR terminology*)" in Ovid Medline. The references of the included articles were reviewed for any additional material. The relevant material was selected by two researchers. A total of 71 articles were identified from the databases, of which two articles met the predefined inclusion criteria. In addition, one article was included in the study from outside the actual search. Two of the included articles were based on drug safety terminology whereas one article was based on medication safety terminology. The results revealed that there is still a considerable heterogeneity of the terms in the literature. The literature shows several terms and definitions for the same phenomenon and no noticeable consistency in the terms. It would be important to define what a uniform and systematically used terminology would require and to establish a commonly accepted guidelines for its use.
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(2022)Multiple Sclerosis (MS) is an incurable autoimmune demyelinating disease affecting the central nervous system (CNS). Although the detailed pathogenesis remains unclear, recent research has highlighted the involvement of B cells. For decades, however, MS research was based on T cell-focused animal models of autoimmune encephalomyelitis (EAE), which do not reflect the involvement of B cells in the pathogenesis. Therefore, B cell-dependent EAE models are hypothesized to allow a better understanding of MS immunohistopathology and may therefore lead to the development of efficient treatments. In our spontaneous relapsing-remitting (RR) EAE model, B cells are recruited from the endogenous repertoire by transgenic myelin oligodendrocyte glycoprotein (MOG) -reactive T cells, causing the development of EAE in 3–4-month-old mice. Interestingly, MOG-specific antibodies are present long before actual onset of clinical disease and can be detected already in 5-week-old RR mice and disease development in RR mice is dependent both on the presence of (presumably MOG-specific) B cells as well as on stimuli provided by intestinal microbiota. Firstly, we evaluated the broader usability of induced germinal center cell (iGB) culture as a model for B cell repertoire studies. Then, by using iGB culture, we studied whether MOG-specific B cells are present in secondary lymphoid organs of younger than 4-week-old and germ-free RR mice. Finally, this study aimed to investigate whether the repertoire of MOG-specific B cells undergoes significant qualitative changes from young healthy mice to older acutely sick RR mice, and whether at the time of disease onset the recruited MOG-specific B cells expand and mature in the cervical nodes (cLN) or in the CNS. To do so, following the hosting-lab’s previous single-cell RNA sequencing (scRNA-seq) of B cells derived from cLN of 5-week-old RR mice, we performed the scRNA-seq of B cells from CNS, spleen, and cLN of acutely sick RR EAE mice. We demonstrated that iGB culture is an unsuitable tool to expand pre-activated B cells, and hence, in our hands it was inappropriate for repertoire studies. However, iGB culture proved to be useful for screening different organs for MOG-specific B lymphocytes, and we found that anti-MOG antibodies were firstly detected in 3-4-week-old RR mice, and MOG-specific B cells were present also in germ-free RR mice. Our scRNA-seq results revealed many highly expanded MOG-specific B cell clonotypes in acutely sick RR mice. Moreover, the B cell repertoire of sick RR mice was more diverse, including IgG1, IgM, IgG2b, IgG2c, and IgG3 isotypes, compared to healthy 5-week-old RR mice that had only IgG1 or IgM isotypes. Two-thirds of the expanded clonotypes were primarily detected in the CNS in sick RR mice, indicating that clonotypes develop further and continue isotype switching within the CNS. We also detected more somatic mutation in the variable region of expanded clones of sick RR mice compared to 5-week-old RR mice. The results of this study clearly show an antigen-driven evolution of the MOG-specific B cell repertoire from healthy young to acutely sick RR mice, which seems to occur mainly in CNS itself. In contrast, cLN are the major initial priming site of MOG-specific B cells in healthy RR mice, even under germ-free conditions. This suggests that commensal microbiota is not required for initial recruitment of MOG-specific B cells, but for the development of EAE. To further validate our encouraging scRNA-Seq results, it is necessary, in future experiments, to confirm the MOG-specificity of expanded clonotypes.
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(2022)Viral promoters are an essential part of a normally functioning virus. Their main task is to drive the transcription of genes which govern hijacking of cell function and replication of viral particles. In addition to supporting normal function of a virus, they can be used to drive the transcription of transgenes which can be used in different therapies. In oncolytic therapies, transgenes can be used to prime the host system against neoplasms which has been shown to generate long term anti-tumour immunity. Human adenoviruses (Ad) are commonly used as a platform for oncolytic virotherapies. Human Ad’s replicate poorly in mouse tumour cell lines, yet some promoters, which are included in the viral constructs to drive the transcription of beneficial transgenes, are able to function. Currently it is unknown whether E3, the native promoter of adenovirus 5 of the E3 region, is capable of functioning in murine cell lines. In this thesis we study whether human cytomegalovirus promoter (CMV) and E3 differ in their efficacy to drive the transcription of the mOX40L and mCD40L transgenes. In the experimental part of this thesis, we compared the efficacies of two viral promoters, AdE3 and AdCVM, in transcribing mOX40Land mCD40L in vitro. Efficacy of transcription was assessed through immunofluorescence and flow cytometry in human and murine cell lines. Furthermore, the effects of promoters on viral infection, killing and replication were evaluated in burst assay and the colorimetric MTS proliferation assay. MTS and burst assay were conducted to confirm if viral infection, killing and replication occurs in human and murine cell lines. Both AdE3 and AdCMV were able to infect and kill human cell lines and cell viability decreased in correlation to the number of viral particles used. In murine cell lines, no decrease in cell viability was detected in the 4T1 cell line. In burst assay, viral replication was observed for both AdE3 and AdCMV in the human MDA-MB-436 cell line. In murine CT26 cell line, no replication was observed for AdE3 or AdCMV constructs. Immunofluorescence assay was performed to visualize transgene expression and localization. Results indicated that mOX40L was localized on cell surface while mCD40L was detected both outside and inside of the cytosolic compartment. Flow cytometry results revealed that both AdE3 and AdCMV constructs are capable of efficiently transcribing mOX40L in human cell lines. In the flow cytometry results for AdE3, two large cell populations with different fluorescence intensities were detected. AdCMV lacked this feature which is postulated to be due to higher lytic activity of the viral construct. In murine cell lines, HCMV could produce mOX40L, but production in murine cell lines was severely attenuated compared to human cell lines. mOX40L produced by the AdE3 construct did not differ from the baseline and was deemed incapable of producing mOX40L in murine cell lines. For the purpose of studying novel virotherapeutics the results of this thesis would indicate that human CMV can be used to drive expression of transgenes in murine cell lines. Despite this, it is preferable to use host specific viruses and promoter sequences for a better translation between mice and humans. Viruksen promoottorit ovat keskeisessä osassa toimintakykyisessä viruksessa. Virus promoottorin päätarkoituksena on geenien transkriptio, mitkä vastaavat solun keskeisten toimintojen kaappaamisesta ja virus partikkeleiden replikaatiosta. Näiden toimintojen lisäksi promoottoreita voidaan käyttää transgeenien transkriptiossa, mitä voidaan hyödyntää sairauksien hoidossa. Onkolyyttisissä terapioissa transgeenejä voidaan käyttää virittämään kehon immuunipuolustus taistelemaan kasvainkudosta vastaan. Ihmisen adenovirusta käytetään usein onkolyyttisten viroterapioiden alustana. Ihmisen adenovirus (Ad) replikoituu hyvin heikosti hiiren syöpäsoluissa, mutta osa adenovirukseen sisälletyistä eksogeenisistä promoottoreista, joita käytetään terapeuttisten transgeenien transkription ajamiseen, kykenee toimimaan ja tuottamaan haluttua proteiinia. Tällä hetkellä ei tiedetä, kykeneekö E3, joka on adenoviruksen E3 lokuksen promoottori, toimimaan hiiren solulinjoissa. Tässä tutkielmassa selvitämme ihmisen sytomegalovirus promoottorin (CMV) ja E3 eroa niiden tehossa ajaa mOX40L ja mCD40L transgeenien transkriptiota. Kokeellisessa osuudessa vertailimme kahden virus promoottorin, E3 ja CMV, eroa niiden tehossa ajaa mCD40L ja mOX40L transkriptiota in vitro. Transkription tehoa tutkittiin immunofluoresenssin ja virtaussytometrian avulla ihmisen ja hiiren syöpäsolulinjoissa. Tämän lisäksi promoottorien vaikutusta virus infektioon, replikaatioon ja kykyyn tappaa soluja arvioitiin burst kokeella ja kolorimetrisellä MTS menetelmällä. MTS ja burst kokeiden avulla varmistettiin AdE3 ja AdCMV virusten kyky infektoida, tappaa ja replikoitua ihmisen ja hiiren syöpäsolulinjoissa. Sekä Ad3 ja AdCMV todettiin kykenevän infektoimaan ja tappamaan ihmissyöpäsoluja ja solujen viabiliteetin lasku korreloi virus partikkeleiden määrän kanssa. Hiiren 4T1 syöpäsoluissa ei todettu solujen viabiliteetin laskevan. Burst kokeessa havaitsimme sekä AdE3 että AdCMV kykenevän replikoitumaan ihmisen MDA-MB-436 solulinjassa. Hiiren CT26 solulinjassa kummankaan viruksen ei havaittu kykenevän replikoitumaan. Immunofluoresenssi kokeessa visualisoimme transgeenien ilmentymisen ja paikantumisen. Tulokset osoittivat, että mOX40L paikantui solun pinnalle. mCD40L havaittiin puolestaan sekä solun ulkopuolella että sytosolissa. Virtaussytometria kokeen tulokset osoittivat, että sekä AdE3 ja AdCMV pystyivät tehokkaasti ilmentämään mOX40L ihmisen solulinjoissa. AdE3 virtausytometria tuloksissa löydettiin kaksi solupopulaatiota, joilla oli toisistaan poikkeavat fluoresenssi intensiteetit. Tätä ilmiötä ei havaittu AdCMV:lla infektoiduilla soluilla, mikä saattoi johtua korkeammasta lyyttisestä aktiivisuudesta. Hiirisolulinjoissa CMV kykeni ilmentämään mOX40L, mutta transkription teho oli selvästi alhaisempi verrattuna ihmissolulinjoihin. E3 promoottorin ilmentämä mOX40L ei eronnut kontrollista ja sen todettiin olevan kykenemätön tuottamaan mOX40L hiirisolulinjoissa. Tuloksemme osoittavat, että ihmisen CMV promoottori kykenee ilmentämään transgeenejä hiiren 4T1 ja CT26 solulinjoissa. On kuitenkin huomattava, että isäntälajille natiivien virusten ja promoottorien käyttö olisi tarkoituksenmukaisempaa tulosten käännettävyyden kannalta hiiristä ihmisiin.
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The Effect of V-MANF on Remyelination in Organotypic Brain Slices and Cuprizone Induced Mouse Model (2022)Multiple sclerosis is a progressive inflammatory disease of the central nervous system that affects young adults. The pathological hallmark of MS is the degradation and loss of oligodendrocytes resulting in demyelination. Damage to axons caused by demyelination severely impairs physical function. Currently there is no cure for MS, but current drugs aim to modify the course of the disease and relieve symptoms. However, they are unable to promote the repair of damaged myelin sheaths, and thus new therapies are needed. In this study, the effect of V-MANF on remyelination was investigated in two commonly used experimental toxin models. V-MANF is a modification of the endoplasmic reticulum located protein MANF, which has been found to have neuroprotective and regenerative properties. Additionally, MANF can regulate ER stress, which contributes to demyelination in MS. The effect of V-MANF on lysolecithin-induced demyelination was examined in organotypic cerebellar brain sections from C57B/6 mice. The study was conducted exceptionally using the brains of adult mice because they are a better model for neurodegenerative diseases. However, when analyzing the results, it was found that there was no demyelination in the tissue cultures, so the effect of V-MANF could not be analyzed. In the other study, C57B/6 mice were given dietary cuprizone for six weeks, followed by daily intranasal administration of either V-MANF or vehicle for seven days. Mice were subjected to behavioral experiments, in which a light/dark box test showed that V-MANFs had a potential anxiolytic effect in mice receiving cuprizone. No significant demyelination was observed by immunohistochemical analysis and therefore the effect of V-MANF on remyelination could not be assessed. However, the results of the study can be utilized in the design of further studies.
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(2022)Native nanofibrillated cellulose is wood-derived, animal-free biocompatible biomaterial which has proved the suitability of nanoscale cellulose fiber based hydrogels for 3D cell culturing and wound healing applications. The problem of freeze-drying nanofibrillated cellulose hydrogel (NFCh) has been the aggregation of the hydrophilic fibrils of the NFC during freeze-drying, which leads deformed freeze-dried cake and unsuccessful reconstitution of the sample. Molecular Dynamic (MD) simulations have been earlier applied in formulation design of NFCh for freeze-drying successfully by screening excipients based on their attraction to the surface of NFCh. The weakness of MD simulations is it can only model the fresh formulation system intend to freeze-dry, but not the actual freeze-drying process and the effect of it and the excipients to the material. To evaluate the protecting properties of excipients and therefore the accuracy of the MD simulations detailed information about changes in the physical state and molecular orientation of the formulation before and after freeze-drying is needed. Non-invasive and label-free Raman spectroscopy can be used to determine vibrational modes of molecules to investigate changes in molecular orientation of the material. The aim of this study was to investigate the possible molecular changes induced by freeze-drying of NFCh-based formulations utilizing Raman spectroscopy and evaluate the connection of the results to MD simulations. NFCh with different excipients was freeze-dried and physicochemical properties, rheology and Raman signal were measured before and after freeze-drying and compared to the literature of MD simulations. The principal component analysis (PCA) was done to the Raman spectra and differences evaluated. The spectra of all formulations differed before and after freeze-drying, and more detailed analysis was done to two most potential 0.8% NFCh based formulations, lactose 300 mM and lactose 250 mM + glycine 50 mM. They had great attraction to NFCh in MD simulations and very similar rheological properties before and after freeze-drying and reconstitution. The spectra of different state of both formulations different on areas between 400 - 500 cm-1 and 850 - 900 cm-1 based on PCA analysis contributing the mutarotation of lactose during freeze-drying and reconstitution. Freeze-drying and the absence of water molecules in NFCh formulation favor different ratios of β and α anomers than the fresh hydrated state which could be detected utilizing Raman spectroscopy. Therefore, Raman spectroscopy was confirmed to be a sensitive option to assess subtle changes in molecular orientation in fresh, freeze-dried, and reconstituted NFCh-based formulations, resulting in a detail knowledge of the molecular behavior of excipients which could be applied in MD simulations and design of better freeze-drying formulations in future.
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(2022)Indomethacin is in a BCS-classification class two drug, meaning it has poor solubility but good permeability. Because of this solubility is a limiting factor for it reaching bloodcirculation. Amorphous form has better solubility than crystalline form. Most common problems with amorphous form are poor stability and process technical problems. In this study Indomethacin was combined with two different kind of polymers that were prepared by hot-melt extrusion. By hot-melt extrusion we can get more stable product than pure amorphous drug. These polymers were polyvinylpyrrolidone (PVPK179 and polyvinylpyrrolidonevinylacetate (PVPVA). They were prepared with Indomethacin 1:1 mass ratio. The aim was to study these extrudates and their stability, cumulative release and especially permeability. By using differential scanning calorimetry, X-ray diffraction and polarized light microscopy it was possible to analyze whether the drug was amorphous or crystalline. In the study it was found that by using hot-melt extrusion it was possible to make amorphous combinations of Indomethacin and polymers. Their permeability was between crystalline and amorphous form. PVPK17-Indomethacin combination had better permeability than PVPVA-Indomethacin combination. On the other hand PVPVA-Indomethacin had better cumulative release than PVPK17-Indomethacin combination
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(2022)There are certain characteristics in children’s medication process, such as weight or body surface area-based drug dosing and off-label use of medications, that expose children to medication errors. Small children especially are prone to physical injuries resulting from medication errors. High-alert medications bear a heightened risk of causing significant, even life-threatening harm to a patient when used in error. The aim of this study was to promote children's medication safety by identifying medication errors and contributing factors to errors associated with the use of high-alert medications in pediatric medication process in a hospital environment. The data of this retrospective register study consisted of voluntary medication error reports (HaiPro) made in the pediatric and adolescent units at Helsinki university hospital (HUS). ISMP's (Institute for Safe Medication Practices) list of high-alert medications in acute care settings was used to limit the data. The data was analyzed by using both quantitative and qualitative methods. The aim of the quantitative analysis was to report the frequencies (n) and proportions (%) of high-alert medications and routes of administration and the aim of the qualitative analysis was to identify the types of medication errors and contributing factors in the data. ISMP’s high-alert medications accounted for approximately one-fifth (19.7%) of all medication error reports made in pediatric and adolescent units in 2018–2020. Twelve medications and intravenous route covered approximately 65.0% of all high-alert medications and routes of administration mentioned in the data. Medication errors were mostly identified in medication administration stage (43.3%) and administration errors were often preceded by prescribing errors. Dosing errors (20.5%) and documenting errors (16.8%) were the most common medication error types in the data. Errors associated with dosing and infusion rate were most often involved in severe medication errors. The most frequently identified contributing factors in the data were associated with the work situation and conditions, documenting and information transfer or medications. More detailed risk analysis considering high-alert medications and the intravenous medication process and targeting preventive barriers to identified risk areas are recommended in pediatric and adolescent units in the future. Barriers should be planned to cover the entire medication process. Among different types of medication errors, multiple dosing errors and errors during the programming of infusion rate require special attention in the future.
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(2022)Operations of pharmaceutical supply chain and medication management practices will be evaluated as part of the ongoing social and health services reform in Finland. One of the goals is to develop digital medication management tools and services to meet the needs of both healthcare professionals and medicine users. The aim of this study was to examine population's willingness to use on new digital services by community pharmacies to promote rational pharmacotherapy and to support cooperation between those involved in the medication use process. The material for this study consisted of the national population survey conducted in 2020 for the VN TEAS report “Activation of price competition for pharmaceutical products and the population's expectations for pharmacy operations” (online survey for 18–79-year-old adults, n = 1650). The survey respondents represented well the target population expect those with higher educational level were over-represented. The current study focused on questions related to digital medication management services provided by community pharmacies, which were divided into the following 4 topics to form sum variables: 1) purchasing and dispensing process of medicines (4 items), 2) customer`s communication with pharmacy and health care personnel (2 items), 3) pharmacy and healthcare personnel`s communication with the customer (4 items) and 4) support services for medication self-management (12 items). The associations of the background variables to the sum variables were calculated using cross-tabulation and the Chi-Square test. Frequencies and percentages were used to present. The majority (85–90%) of the respondents were in favor of the possibility of sending messages electronically between the customer, the community pharmacy and other healthcare personnel by using a shared communication channel, such as My Kanta to update medication information online. Multimorbidity, medication use, and higher medication costs increased the respondent’s positive attitude towards the electronic communication channel. Three-quarters (76%) of respondents were willing to use electronic medicine purchasing and dispensing services. Younger respondents (18–34 years) were more interested in these services than older ones. The electronic medication self-management support services had more discrete opinions among respondents. More than half of the respondents indicated their strong willingness to use at least one of the medication self-management support online services listed in the survey instrument. Those aged 18–34 years (69%), those with higher education (62%), those living in the Province of Southern Finland (60%) and those living in the Helsinki Metropolitan Area (67%) were more positive than others. Of the respondents who opted for pharmacy's remote online services, 55% were willing to seek advice for reconciling their medication list. According to the survey, Finnish adults are willing to use new electronic services by community pharmacies. In particular, they were willing to use a shared electronic communication channel between the customer, the pharmacy and other healthcare personnel, such as MyKanta to update information related to their medication. The willingness to have support self-care support for medication self-management primarily from the pharmacy's online services was lower than the willingness to use online purchasing and dispensing services. Of the remote medication self-management services medication reconciliation had the highest demand. Future research should focus on enhancing use of electronic medication self-management services provided by community pharmacies. Further research should also be targeted to understand medicine user needs for support as it may vary between patient groups, requiring segmentation of services.
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(2022)Etätyö yleistyi maaliskuussa 2020 äkillisesti COVID-19 pandemian seurauksena maailman terveysjärjestö WHO:n suosituksesta. Etätyö on ollut ennen koronapandemiaa harvinaista lääketeollisuudessa, joten etätyötä lääketeollisuudessa on tutkittu hyvin vähän. Etätyön on arvioitu jäävän pysyväksi ratkaisuksi, joten on ajankohtaista tutkia etätyön soveltuvuutta ja tehokkuutta lääketeollisuudessa. Etätyöntekijöiden tuottavuus kasvaa yleensä huomattavasti. Työpaikalla koetaan jatkuvasti keskeytyksiä, melua ja muita häiriötekijöitä, joiden lisäksi työmatkat kuormittavat työntekijöitä. Etätyöntekijät säästyvät suurimmalta osalta näistä ongelmista, jolloin suurempi osa heidän työpäivästään kuluu varsinaiseen työntekoon. Valtaosa etätyöntekijöistä tekee etätyötä osan työajastaan. Tutkimuksen tavoitteena oli selvittää kokemuksia etätyöstä, etätyön soveltuvuutta ja etätyön tehokkuuteen vaikuttavia tekijöitä lääketeollisuudessa. Tutkimus on toteutettu Orion Oyj:n Suomen toimipisteissä. Tutkimuksen toteuttamistapa oli kvantitatiivisen ja kvalitatiivisen kyselytutkimuksen yhdistelmä. Yhdistämällä kvantitatiivisia ja kvalitatiivisia kysymyksiä pyrittiin saamaan tarkempia tietoja kuin pelkällä kvantitatiivisella tutkimuksella voitaisiin saada. Kysely oli avoinna 15.11.–26.11.2021. Vastausprosentiksi saatiin 34,9 %. Etätyön merkittävimmiksi hyödyiksi havaittiin työ- ja vapaa-ajan joustavampi yhteensovittaminen ja se, että etätyössä keskittyminen on parempaa. Kommunikaation koetaan onnistuvan hyvin etätyössä, mutta kasvokkain tapahtuvaa kommunikaatiota pidetään myös tärkeänä. Esimerkiksi kehitys- ja ideointipalaverit olisi hyvä järjestää mahdollisuuksien mukaan kasvokkain. Lisäksi hiljaisen tiedon siirtyminen on vähäisempää etätyössä. Etätyö soveltuu hyvin tutkimus- ja tuotekehitystyöhön, eikä sen koeta heikentävän merkittävästi kykyä innovoida. Tulosten perusteella etätyötä haluttaisiin tehdä enemmän kuin 40 % työajasta ja etätyötä pidetään tehokkaana työskentelytapana. Kyselyssä ei selvitetty, minkälaisia etätyömääriä vastaajat ovat tehneet vahvan etätyösuosituksen aikana. Osa vastaajista on saattanut olla muita enemmän lähitöissä, mikä voi vaikuttaa tuloksiin. Saadut tulokset olivat kuitenkin samansuuntaisia kuin aikaisemmissa tutkimuksissa. Suurin osa tähän kyselyyn osallistuneista oli erittäin kokeneita ja työnsä hyvin osaavia työntekijöitä, mikä voi lisätä etätyömyönteisyyttä tuloksissa.
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(2022)Lääkkeiden saatavuushäiriöt ovat yleistyneet Suomessa ja muualla maailmassa aiheuttaen lisätyötä ja -kustannuksia lääkealan toimijoille. Saatavuushäiriöt voivat aiheuttaa katkoksia lääkehoitoon tai saatetaan joutua turvautumaan muihin hoitovaihtoehtoihin, mikä voi johtaa potilasturvallisuuden vaarantumiseen. Tämän tutkimuksen tavoitteena oli antaa yleiskuva saatavuushäiriöistä ja saatavuushäiriövalmisteiden ominaispiirteistä Suomessa keväällä 2020. Tutkittaviin ominaispiirteisiin kuuluivat mm. lääkkeen terapiaryhmä, myyntiluvan haltija, häiriön kesto, valmisteen hintaluokka, kuuluminen velvoitevarastoitavien valmisteiden tai Maailman terveysjärjestö WHO:n välttämättömien lääkkeiden luetteloon ja myyntiluvan myöntövuoteen perustuva lääkkeen elinkaarivaihe. Saatavuushäiriövalmisteiden (n=879) tiedot kerättiin myyntiluvan haltijoiden Lääkealan turvallisuus- ja kehittämiskeskus Fimealle kahden kuukauden aikana (14.2.–15.4.2020) toimittamista tai voimassa olevista saatavuushäiriöilmoituksista. Aineistoa täydennettiin hinta- ja korvattavuustiedoilla Kansaneläkelaitoksen lääketietokannasta sekä tiedoilla muista markkinoilla olevista pakkauskoista, vahvuuksista ja vaihtokelpoisista lääkevalmisteista. Aineistosta tehtiin kuvaileva tilastollinen analyysi käyttäen perustunnuslukuja ja -jakaumia. Analyysissä keskityttiin pääasiassa avohoidossa käytettäviin reseptivalmisteisiin (n=654). Ihmislääkkeiden saatavuushäiriöt (n=829) koskivat etenkin sairausvakuutuksesta korvattavia reseptivalmisteita (65 % kaikista saatavuushäiriöistä), ja ne keskittyivät suurten potilasryhmien käyttämiin lääkkeisiin, kuten sydän- ja verisuonisairauksien lääkkeisiin (31 %) ja hermostoon vaikuttaviin lääkeaineisiin (28 %). Avohoidon reseptivalmisteiden häiriöistä yli puolet (53 %) kohdistui rinnakkaisvalmisteisiin. Häiriövalmisteet kuuluivat elinkaarivaiheeltaan vanhempiin ja hintaluokaltaan edullisempiin valmisteisiin. Viidennes valmisteista (19 %) kuului velvoitevarastoitavien tai WHO:n välttämättömien lääkkeiden luetteloon. Rinnakkaisvalmiste löytyi 73 prosentille häiriövalmisteista. Vain kolme prosenttia myyntiluvan haltijoista oli tehnyt ilmoituksen saatavuushäiriöstä Fimealle vaadittua kahta kuukautta ennen myynnin keskeytymistä saatavuushäiriön vuoksi. Tulosten perusteella saatavuushäiriöt Suomessa koskevat samankaltaisia lääkevalmisteita kuin muuallakin maailmassa. Tämän osoitti myös tutkielman kirjallisuusosassa toteutettu kansainvälistä empiiristä saatavuushäiriötutkimusta koskenut systemaattinen kirjallisuushaku. Valtaosaan saatavuushäiriöistä on mahdollista reagoida apteekissa toimittamalla rinnakkaisvalmiste, kun taas osa vaatii yhteydenottoa lääkkeen määränneeseen lääkäriin. Saatavuushäiriötiedon linkittämistä sähköiseen reseptijärjestelmään ja lääkevaihdon laajentamista farmasian ammattilaisille voisi harkita toiminnan kehittämiseksi saatavuushäiriötilanteissa. Covid-19-pandemia on lisännyt kansainvälisiä toimia häiriötilanteiden hoitamiseksi. Tätä varten kehitetään yhteisiä toimintatapoja muun muassa Euroopan unionissa, jossa tavoitteena on luoda kaikki jäsenmaat kattava saatavuushäiriöportaali.
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(2022)Parkinson’s disease (PD) is a progressive neurodegenerative disorder with the neuropathological hallmark of intraneuronal inclusions called Lewy bodies (LB). Accumulation of α-synuclein (α-syn) and cellular components into LBs coincides with degeneration of dopaminergic neurons in the midbrain, substantia nigra. Degeneration of dopaminergic neurons eventually leads to motor dysfunctions. Currently, the treatments for PD are symptomatic. For this reason, new disease-modifying treatments are needed to slow down or prevent the disease progression. Neurotrophic factors (NTFs) have been an interest of research for a couple of decades because of their neuroprotective properties. The main aim of this study was to investigate if brain-derived neurotrophic factor (BDNF) reduces pre-formed fibril (PFF) induced aggregation of α-syn in dopaminergic neurons. PFF-model was used to mimic the accumulation of LBs in neurons, as PFFs induce aggregation of endogenous α-syn in neurons. Additionally, the dose dependence of BDNF was tested. The secondary objective was to investigate the interaction of tropomyosin receptor kinase B (TrkB) signaling pathway and α-syn aggregation using TrkB agonists and antagonists. The cultured dopaminergic neurons isolated from the midbrain of mouse embryos were treated with PFFs on the day in vitro (DIV) 8. BDNF or control treatments were added either 1 hour after the PFF-treatment or on DIV 12. Neurons were fixed on DIV 15 and fluorescent immunohistochemistry was performed. After the detection of fluorescence with automated, high-content imaging, image analysis was done for quantifying dopaminergic neurons, and dopaminergic neurons positive for LB-like aggregates by using unbiased image analysis CellProfilerTM software. Both BDNF and positive control glial cell line-derived neurotrophic factor (GDNF) significantly reduced LB-like aggregates in dopaminergic neurons at both timepoints. GDNF was more effective at both timepoints than BDNF. Both tested doses of BDNF lowered the number of LB-like aggregates, but a more robust effect was seen with the higher dose. The highest tested dose for the TrkB agonists was toxic to the cultured dopaminergic neurons, whereas the lower doses did not affect either the survival or the number of LB-like aggregates. BDNF promoted the survival of the dopaminergic neurons despite the survival-reducing adverse effect of TrkB antagonist K252a. This study provided new information on the effects of exogenously added BDNF on PFF-model with primary neuronal culture. Research on the underlying mechanisms of α-syn aggregation and the protective effects of NTFs can forward the development of new therapies against PD.
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(2022)The problems caused by hypromellose in sterile filtration of ophthalmic products in the pharmaceutical industry were investigated. The research project was performed at NextPharma Oy's ophthalmics manufacturing facility in Tampere during the autumn of 2020. Hypromellose is an excipient commonly used in ophthalmic products as a viscosity enhancer to prolong the contact time of the preparation on the eye surface. In the ophthalmics compounding process, hypromellose is first dispersed by slowly sprinkling it into a hot solution and thoroughly mixing, after which the solution is cooled to room temperature. During cooling, the hypromellose dissolves and gels, increasing the viscosity of the solution. Incomplete dispersion or dissolution of hypromellose during the manufacturing process can slow down the filtration rate or even clog the filter completely due to undissolved hypromellose polymer material. Hypromellose is an industrially produced cellulose derivative that often contains some amounts of unreacted cellulose and other sparingly soluble polymer particles as impurities, which can also cause problems in filtration processes. Sterile filtration is a commonly used sterilization method for ophthalmic products, in which the prepared bulk solution is filtered through a 0.1 to 0.2 µm pore size filter membrane into a sterile receiving vessel. Due to the very small pore size, sterile filters are easily clogged if the solution contains poorly dissolved material. The purpose of this work was to collect additional information on the possible causes of clogging caused by hypromellose and to determine whether the filterability of a solution containing hypromellose can be improved by optimizing the manufacturing process parameters. The design of experiments was prepared, creating a two-level full-factorial test matrix without replicates and with three centre points. Four different process parameters were used (mixing time, mixing speed, dispersion temperature, and cooling temperature). Minimum and maximum levels for the parameters were obtained in the initial tests, after which the test solutions were prepared and filtered in a randomized order according to the test matrix. The aim of the screening was to find out which parameters were affecting the filterability and what would be their optimal combination that would maximize the filtration rate and the yield of filtration. Finally, the optimized parameters were used to test different batches of hypromellose, comparing the results to previous filtration tests. Additionally, an alternative hypromellose dispersion method was tested to minimize the amount of insoluble material remained during the dispersion and cooling steps. Of the parameters tested, mixing speed was the least significant, while cooling temperature had the most effect on the filtration results. The solutions with lower cooling temperature had better filtration results, which may be due to reduced aggregation of hypromellose due to increased hydration of the polymer chains. The temperature behaviour of hypromellose solutions could be an interesting subject for further investigation. Longer mixing times and higher dispersion temperatures produced slightly better filtration results on average, but the differences were not statistically significant. Most challenging in the study was controlling the temperature and mixing of the solutions, and the retention of insoluble hypromellose material at the walls of the compounding vessel. The alternative dispersion method gave promising preliminary results, but the method still requires further testing. It would be important to also find the root cause of the filter clogging mechanism e.g., by further analysing the clogged filter membrane. The study provided additional useful information of the behaviour of hypromellose solutions in solution preparations and during sterile filtration, which has been helpful in solving production problems.
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(2022)Drug-induced liver injury (DILI) is a relatively rare hepatic condition that can be classified as predictable and unpredictable. However, DILI is a primary reason for drug withdrawals, post-marketing warnings, and restrictions of use. DILI is a problem for the drug users but also for the pharmaceutical industry and regulatory bodies. From the perspective of patients' and clinicians', DILI is the major cause of acute liver injury. At present, a major problem predicting DILI in drug discovery is a poor understanding of its mechanisms as well as the complexity of DILI pathogenicity. The main mechanism behind DILI are alterations in bile acid homeostasis, oxidative stress, and mitochondrial dysfunction. More than 50 % of drugs causing DILI are causing mitochondrial impairment. If the normal function of mitochondria is disturbed, the energy production of the cell decreases, and cell function decline leading eventually to the cell death. In this study prediction of mitochondrial toxicity was studied using cryopreserved primary hepatocytes of humans and rats. The aim of the study was to clarify if there are interspecies differences in the prediction of toxicity but also investigate possible differences in the mechanisms behind hepatotoxicity by using three well-known compounds toxic to mitochondria. To determine these differences, total cellular ATP was measured after 2- and 24- hour exposure time to gain information on overall viability and possible adaptive responses. Mitochondrial energy pathways were studied as a real-time monitoring acute exposure of test compounds. Morphology, location, and possible adaptive response of mitochondria were studied using a fluorescent probe and antibody staining combined with high content imaging (HCI). Overall, primary rat hepatocytes were more sensitive to the test compounds than human hepatocytes. Also, there were differences between human hepatocyte batches that may reflect the metabolic differences between hepatocyte donors. Immunolabeling did not bring any additional values compared to the fluorescent probe staining in the study of morphology of mitochondria. Additionally, it was noticed that treatment with paraformaldehyde significantly changed the hepatocyte mitochondria morphology. Overall, more effort is needed to develop image analysis of mitochondria morphology. Finally, studying mitochondrial morphology has proven to be difficult, and this study did not unfortunately reveal any information about the adaptive responses of mitochondria for drug-induced liver injury.
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(2022)More and more drugs for the treatment of lung cancer are entering the market with limited research evidence and high cost. However, health care resources are limited. To provide rationale and sustainable treatment for all patients, the need for health technology assessments has increased. International value frameworks with varying uses, structures, and components have also been developed to help assess the value of drug therapies. The purpose of the study is to illustrate how physicians, authorities, and pharmaceutical industry experts define the value and the effectiveness of drug therapy. The study also aims to chart the attitudes of health care professionals towards international value assessment frameworks and to describe the current challenges in health technology assessments focusing on lung cancer therapy. In addition, the purpose of the study is to evaluate the importance of therapeutic and economic evaluation of lung cancer therapies. The research material includes interviews with physicians (n=2), authorities (n=3), and pharmaceutical industry experts (n=5). The interviews were conducted as an individual (n=8) and pair interviews (n=1). The interview method used was a semi-structured thematic interview. The interviews were analyzed by using inductive and abductive content analysis and theming. The theoretical framework in the study was related to the challenges of assessing the therapeutic and economic value of pharmacotherapies. According to the study, the value and effectiveness of drug therapy are determined in a varied and perspective-dependent manner. The value of drug therapy can be divided into three dimensions, which were therapeutic, social, and economic impact. Treatment’s effectiveness was primarily determined by the health benefits gained and by the effects the therapy has on patients, society and care pathways. Based on the data, the current challenges of the therapeutic and economic evaluation of pharmacotherapies are related to the implementation methods and criteria of evaluation and decision-making, resources, cooperation needs, scientific evidence, ethics, the structure of the health care system and legislation. Based on the results, physicians, authorities, and pharmaceutical industry experts have different opinions of the need for cooperation. The interviewees also evaluated differently the status of the current development activities and the importance of international evaluations. There were also differences in the opinions on how important the therapeutic and economic evaluation of lung cancer therapies was considered. If the importance was considered low, the importance of the evaluations was expected to increase only after the refinement of treatment recommendations and guidelines. According to the data, the international value frameworks are not actively used in Finland and their significance will be considered insignificant in the future as well. The usefulness of the value frameworks was primarily limited due to structural factors, the assessment of reliability and the current evaluation system in Finland. The benefits of the value frameworks were primarily related to the coherence of the evaluation process, easing the evaluation process and improving patient equality.
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(2022)Medication related risks have been identified as one of the main threats to patient safety, both internationally and nationally. In Finland, implementation of pharmacotherapy in health services system is guided by the Safe pharmacotherapy -guideline. The guideline instructs work units to implement a pharmacotherapy plan, which is a statu-tory quality management document to describe the unit’s pharmacotherapy process and related responsibilities and obligations. However, there is currently limited research data available on pharmacotherapy plans and their impact on medication safety. The aim of this study was to explore the use of pharmacotherapy plans as a tool for promoting medication safety in the Finnish health services system with an emphasis on systems-based risk management. The research was con-ducted as an electronic survey in November-December 2021. The target group of the survey was health care professionals licensed as nurses and pharmacists who are working in wards or clinics or otherwise participate in drawing up or updating of pharmacotherapy plans. The study analyzed 901 responses. Most respondents (90 %) worked as licensed nurses and 10 % as pharmacists. The majority of the respondents’ units (91,5 %, n=824) had a pharmacotherapy plan. Medication safety practices were comprehensively described in pharmacotherapy plans and no significant differences observed between work environments. The multi-professional development processes of pharmacotherapy plans were not complete, only 11,6 % of the units the writing was done in multi-professional collaboration. Medication safety practices were best implemented in university hospitals (m. 3,87, sd. 0,57), with the difference being statistically significant for primary healthcare wards (m. 3,51, sd. 0,63, p<0,001) and social care housing services units (m. 3,63, sd, 0,68, p=0,018). The comprehensiveness of the content in pharmacotherapy plans and the implementation of medication safety practices were correlated (r=0,60, p<0,001). Pharmacotherapy plan is an important tool for systems-based medication safety promotion in the Finnish health services system. There is need for improvement in the multi-professional collaboration when developing the plans and in training the healthcare staff of practices described in the unit’s pharmacotherapy plans. In the future, special emphasis should be placed on the medication safety and development of primary healthcare wards and social care units.
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(2022)The aim of this master’s thesis was to investigate whether drug-induced inhibition of cytochrome P450 enzymes (CYP), especially time-dependent inhibition (TDI), could be the reason for bioaccumulation of the pharmaceuticals present in the aquatic environment in fish and whether the in vitro method could identify pharmaceuticals causing an environmental risk, which should primarily be investigated more closely. The half-maximal inhibitory concentrations (IC50) of seven antimicrobial drugs detected in the environment (erythromycin, clarithromycin, ketoconazole, clotrimazole, miconazole, ciprofloxacin, and sulfamethoxazole) and three known human time-dependent inhibitors (furafylline, diltiazem and verapamil) chosen for the validation of the method, were determined by EROD (7-ethoxy-resorufin-O-deethylase) and BFCOD (7-benzyloxy-4-trifluoromethyl-coumarin-O-debenzyloxylase) activities. The IC50 shift method and commercially available rainbow trout (Oncorhynchus mykiss) liver microsomes were used in determinations. The known human time-dependent inhibitors chosen for the validation of the method, furafylline (EROD) and diltiazem (BFCOD) proved to be possible time-dependent inhibitors also in rainbow trout in vitro, but this was not observed for verapamil (BFCOD). All antimicrobial drugs, except ciprofloxacin, inhibited more selectively BFCOD-reaction, as in human. In the case of sulfamethoxazole, inhibition was not observed at the concentrations used (0–500 µmol/L). Both enzyme activities (EROD and BFCOD) were inhibited in rainbow trout by ketoconazole, clotrimazole and miconazole. Among antimicrobial drugs acting as time-dependent inhibitors in human, erythromycin inhibited BFCOD activity in a time-dependent manner also in rainbow trout, but this was not observed for clarithromycin. Strongest inhibitors for CYP enzymes of rainbow trout in vitro were ketoconazole (EROD, IC50=4,19 µM and BFCOD, IC50=2,31 µM) and clotrimazole (EROD, IC50=33,78 µM and BFCOD, IC50=1,55 µM). The IC50 values of diltiazem, erythromycin, clarithromycin, ciprofloxacin, and verapamil were of the same order of magnitude as in human. The IC50 values of furafylline, ketoconazole, clotrimazole and miconazole were several times higher in rainbow trout than in human. Based on the results of this study, the IC50-shift method is also valid for fish, but there are differences in the inhibition potencies between human and fish, and the inhibition potency of human CYP enzymes cannot therefore directly predict enzyme inhibition of fish or the mechanism of inhibition. The In vitro measured IC50 values of rainbow trout were several orders of magnitude higher than the average concentrations of the pharmaceutical residues measured in the environment. Exposure to pharmaceutical mixtures is long-term, so interactions and bioaccumulation may still be possible due to inhibition of CYP enzymes. Developing a valid in vitro method for environmental risk assessment would be important, as animal experiments are ethically challenging.
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