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(2010)Most new drug molecules discovered today suffer from poor bioavailability. Poor oral bioavailability results mainly from poor dissolution properties of hydrophobic drug molecules, because the drug dissolution is often the rate-limiting event of the drug's absorption through the intestinal wall into the systemic circulation. During the last few years, the use of mesoporous silica and silicon particles as oral drug delivery vehicles has been widely studied, and there have been promising results of their suitability to enhance the physicochemical properties of poorly soluble drug molecules. Mesoporous silica and silicon particles can be used to enhance the solubility and dissolution rate of a drug by incorporating the drug inside the pores, which are only a few times larger than the drug molecules, and thus, breaking the crystalline structure into a disordered, amorphous form with better dissolution properties. Also, the high surface area of the mesoporous particles improves the dissolution rate of the incorporated drug. In addition, the mesoporous materials can also enhance the permeability of large, hydrophilic drug substances across biological barriers. T he loading process of drugs into silica and silicon mesopores is mainly based on the adsorption of drug molecules from a loading solution into the silica or silicon pore walls. There are several factors that affect the loading process: the surface area, the pore size, the total pore volume, the pore geometry and surface chemistry of the mesoporous material, as well as the chemical nature of the drugs and the solvents. Furthermore, both the pore and the surface structure of the particles also affect the drug release kinetics. In this study, the loading of itraconazole into mesoporous silica (Syloid AL-1 and Syloid 244) and silicon (TOPSi and TCPSi) microparticles was studied, as well as the release of itraconazole from the microparticles and its stability after loading. Itraconazole was selected for this study because of its highly hydrophobic and poorly soluble nature. Different mesoporous materials with different surface structures, pore volumes and surface areas were selected in order to evaluate the structural effect of the particles on the loading degree and dissolution behaviour of the drug using different loading parameters. The loaded particles were characterized with various analytical methods, and the drug release from the particles was assessed by in vitro dissolution tests. The results showed that the loaded drug was apparently in amorphous form after loading, and that the loading process did not alter the chemical structure of the silica or silicon surface. Both the mesoporous silica and silicon microparticles enhanced the solubility and dissolution rate of itraconazole. Moreover, the physicochemical properties of the particles and the loading procedure were shown to have an effect on the drug loading efficiency and drug release kinetics. Finally, the mesoporous silicon particles loaded with itraconazole were found to be unstable under stressed conditions (at 38 qC and 70 % relative humidity).
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(2020)Left ventricular hypertrophy (LVH) takes place when cardiomyocytes respond to excessive stress by growing in size. Cardiomyocytes have a very marginal capability to proliferate, which is why hypertrophic growth is almost their only option to meet the requirements of increased workload. In the long run, however, LVH leads to further problems, such as cardiac failure and an increased risk of myocardial infarction. Hypertension is the most prevalent cause of LVH, and its current treatment relies on antihypertensive drugs. They decrease the workload of the heart and therefore alleviate symptoms but have very little effect on the built damage and remodeling. Understanding the details of cellular level signaling pathways and genetic expression in LVH is crucial for future drug development. Regulation of gene expression is a very complex process, which involves more than just DNA being translated into a protein. In this project, two types of factors participating in this regulation were in focus: long non-coding RNAs (lncRNA) and transcription factors GATA4 and FOG2. LncRNAs are RNA sequences of more than 200 nucleotides that do not code for any protein final products themselves but are involved in chromatin remodeling as well as transcriptional and post-transcriptional gene regulation. They are highly organ-selective, which makes them potential targets for drug development. Our group has previously found a selection of cardiomyocyte-selective lncRNAs, which share a similar expression pattern in neonatal mouse hearts. In this project, three of them were silenced in a primary cardiomyocyte culture while simultaneously hormonally inducing hypertrophy. The goal was to see whether these lncRNAs have an effect on the hypertrophic response and apoptosis in the cardiomyocytes. Transcription factors are proteins with partially similar activities to lncRNAs; they regulate, which genes are expressed under certain circumstances. GATA4 is an important transcription factor in the heart as it targets various developmental and functional genes in cardiomyocytes. FOG2 is a cofactor of GATA4; interaction between them regulates the activity of GATA4. Our group has recently developed a selection of compounds that affect protein-protein interaction between GATA4 and NKX2-5, another important transcription factor. The second part of the project was to set up and optimize a compound screening assay for GATA4-FOG2 interaction. The results showed no change in hypertrophic response when the lncRNAs were silenced. Other experimental designs could still reveal if they have effects that could not be seen with these protocols. The silencing had no effect on apoptosis. As for the GATA4-FOG2 interaction experiments, transfecting COS-1 with GATA4 and FOG2 plasmids in a ratio of 10:1 resulted in a signal suitable for compound screening. Initial compound screening results indicated the compounds may have an effect on GATA4-FOG2 interaction, but further studies are needed before drawing conclusions.
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(2015)Susceptibility to antibiotics is constantly developing in bacteria due to selection pressure caused by use of antibiotics. For this reason, finding new antimicrobial substances is imperative. High-throughput screening (HTS) is an important tool to find new active substances. The need to analyse as many substances in as small time as possible is emphasised in modern drug development. Robust methods, suitable for fast throughput of substances, miniaturisation and automation, are particularly useful. In the context of antimicrobial screening, methods utilising bioluminescence can correspond this need, and genetic engineering can help in developing bacterial strains with beneficial features for screening. In this work, two screening methods were developed and optimised using genetically engineered Escherichia coli strains. The screening methods make use of the bioluminescent properties of the strains, and the methods can be used to screen compound libraries for antimicrobials rapidly enough to approach HTS. The strain E. coli WZM120/pCGLS 11 is constitutively luminescent, so weakening of luminescence means the cell viability weakens. The strain E. coli K12/pCSS305, where luminescence is produced by a heat-inducible runaway plasmid, can be used to especially detect compounds inhibiting DNA replication. In developing the method, workflow was optimised and conditions were validated so as to enable possible HTS campaigns. The target was to create as simple, fast and reproducible a method as possible. The Z' values calculated in assessing the performance are excellent for a cell-based method. The signal is readily distinguishable, the bacterial strains are in a stable manner, and the method is well reproducible. It is possible to continue assay development from 96-well format to 384-well format.
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(2012)Natural products have been used as medicines for thousands of years. Of the drugs on the market today a significant proportion are natural products or natural product derivatives. Natural products can be enhanced by the means of chemical modification. Modification of a natural product may result in lesser toxicity, greater efficacy or better chemical stability. Different ways to modify a natural product are represented in the literature review using approved drugs as examples. Biological screening is an important part of a modern drug discovery process. Libraries containing synthetic molecules or natural products can be screened. The literature review discusses different types of natural product libraries and how they differ from synthetic libraries. Natural product libraries are smaller and more laborious to screen compared with synthetic libraries. Natural product libraries contain more hits in proportion of total compounds because natural products have activity in biological systems more often than synthetic molecules. A remarkable part of antibiotics and anti-cancer agents are derived from nature. A need for especially new antibiotics will be notable in the future due to resistant microbial strains and the need can be met with natural product research. The object of the experimental part was to evaluate the bioactivity of eleven synthetic abietic acid derivatives. Antimicrobial activity of the compounds was determined againts six human pathogens which were S.aureus, E.coli, P.aeruginosa, E. aerogenes, E. faecalis and Candida albicans. Cytotoxicity testing on the compounds was performed using mammalian cell lines CaCo-2 and Huh-7. Compounds were tested for albumin binding using bovine serum albumin. The effect of bovine serum albumin on the antimicrobial effect of compounds was studied. Spectrophotometric studies on compound-albumin complexes were carried out using fluorescence and UV absorbance measurement techniques. A primary antimicrobial screening was performed with all the compounds. Minimum inhibitory concentration (MIC) values were determined for compounds that showed antimicrobial activity in the primary screening. Cytotoxicity testing was carried out with all the compounds. Albumin binding was studied only on compounds that showed activity in the antimicrobial screening. Some of the compounds were noticed to have antimicrobial activity against the studied gram-positive bacteria and yeast Candida albicans. Antimicrobially active compounds were noticed to bind to albumin and have cytotoxic effects.
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(2014)This study explores the research, characteristics, manufacturing processes, safety and applications of graphene from the perspective of pharmacy and medicine. The study also examines how graphene research and commercialization has developed in the last ten years (2004-2013), with an emphasis on biomedical research globally and separately in Finland. The methods employed are an extensive literature review of scientific publications, and a survey of the biomedical research emphases, geographical distribution, and funding of graphene research based on article and patent databases. Graphene holds considerable potential in pharmaceutical use. Clinical trials can commence as soon as the manufacturing processes develop to produce graphene of sufficient quality. The variety of biomedical uses of graphene is vast: antibacterial products and coatings, gene therapy, tissue technology, sensor and imaging technology, as well as utilization in drug delivery. Graphene can be used to enhance therapeutic effectiveness by creating instruments for targeted and controlled drug delivery. In addition to uses in therapeutics, graphene offers possibilities for diagnostics. The biomedical research and commercialization of graphene have accelerated in the recent years, but research and patenting activity has concentrated in Asia, and especially in China. The research has been university driven and primarily publicly funded. In Finland, graphene research has focused on electrical applications, whereas research in the fields of pharmacy and medicine has been limited. As a so-called high-tech country, Finland could increase research into graphene as an innovative pharmaceutical instrument.
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(2011)Nearly one fourth of new medicinal molecules are biopharmaceutical (protein, antibody or nucleic acid derivative) based. However, the administration of these compounds is not always that straightforward due to the fragile nature of aforementioned domains in GI-tract. In addition, these molecules often exhibit poor bioavailability when administered orally. As a result, parenteral administration is commonly preferred. In addition, shelf-life of these molecules in aqueous environments is poor, unless stored in low temperatures. Another approach is to bring these molecules to anhydrous form via lyophilization resulting in enhanced stability during storage. Proteins cannot most commonly be freeze dried by themselves so some kind of excipients are nearly always necessary. Disaccharides are commonly utilized excipients in freeze-dried formulations since they provide a rigid glassy matrix to maintain the native conformation of the protein domain. They also act as "sink"-agents, which basically mean that they can absorb some moisture from the environment and still help to protect the API itself to retain its activity and therefore offer a way to robust formulation. The aim of the present study was to investigate how four amorphous disaccharides (cellobiose, melibiose, sucrose and trehalose) behave when they are brought to different relative humidity levels. At first, solutions of each disaccharide were prepared, filled into scintillation vials and freeze dried. Initial information on how the moisture induced transformations take place, the lyophilized amorphous disaccharide cakes were placed in vacuum desiccators containing different relative humidity levels for defined period, after which selected analyzing methods were utilized to further examine the occurred transformations. Affinity to crystallization, water sorption of the disaccharides, the effect of moisture on glass transition and crystallization temperature were studied. In addition FT-IR microscopy was utilized to map the moisture distribution on a piece of lyophilized cake. Observations made during the experiments backed up the data mentioned in a previous study: melibiose and trehalose were shown to be superior over sucrose and cellobiose what comes to the ability to withstand elevated humidity and temperature, and to avoid crystallization with pharmaceutically relevant moisture contents. The difference was made evident with every utilized analyzing method. In addition, melibiose showed interesting anomalies during DVS runs, which were absent with other amorphous disaccharides. Particularly fascinating was the observation made with polarized light microscope, which revealed a possible small-scale crystallization that cannot be observed with XRPD. As a result, a suggestion can safely be made that a robust formulation is most likely obtained by utilizing either melibiose or trehalose as a stabilizing agent for biopharmaceutical freeze-dried formulations. On the other hand, more experiments should be conducted to obtain more accurate information on why these disaccharides have better tolerance for elevating humidities than others.
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(2023)Obesity has increased in our society for decades and is still increasing. It is a burden for individuals and societies. The healthcare costs, disability, illnesses, and deaths caused by it are unfortunately a big burden on global scale. Binge eating disorder is an eating disorder in which a person uncontrollably devours an excessive amount of food due to a lack of self-control. Binge eating disorder is strongly linked to obesity and it further increases the weight of both normal weight and obese people. Many mechanisms influence the regulation of eating. A long-term research subject and affecting the regulation of eating, serotonergic and serotonin receptors, affect the amount of food eaten and the reward system, and disturbances in serotonin signaling have been linked to obesity. Aim of this study was to exam binge-like eating modelled C57Bl/6J mice and their food consumption, while affecting serotonergic signaling. I studied psychoactive LSD and antipsychotic MDL 100907 effects on serotonergic signaling in a binge-like eating model, using drugs both separately and simultaneously. Mice were induced into a stress-free model of binge-like eating by providing high-energy food once a week for 24 hours. When the binge eating model was runnig, once a week the mice were dosed with a drug or substances and given energy-dense food to binge on. In the study, consumed food and water were measured. The mice were also subjected to locomotor tests to ensure that they were able to eat motorically. Induction of the binge-like eating model was successful and a reduction in binge eating was observed in mice under LSD alone at significant time points. MDL reduced binge-like eating at the first time point. No significant changes were observed in the water intake. The locomotor tests ensured a sufficient amount of movement to enable eating. Even though the drugs individually reduced binge-like eating, it should be noted that the properties of the drugs, and especially the trials of their combined use, which did not show significant results, do not promise significant discoveries in terms of similar research.
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(2012)The purpose of this study was to investigate how the mixing time of the magnesium stearate affects on the compressibility of partially pregelatinized maize starch. Pregelatinized maize starch is used in pharmaceuticals as a filler, binder and as disintegrant. Because pregelatinized maize starch has lubricant characteristics itself, it is known to be sensitive for the amount and the mixing time of magnesium stearate. The aim is that magnesium stearate is not totally homogenously mixed on the powder surfaces so that even, clean powder surfaces exist. Homogeneous mixing means that particles are coated with magnesium stearate, which as a hydrophobic ingredient prevents bond formation between plastically and elastically behaving particles. Too much magnesium stearate and/or too long mixing time may cause weakening of tablet tensile strength, laminating and capping. The weakening of the tensile strength of the tablet increases friability, which causes problems during packaging process and the transportation. Too much magnesium stearate may also lengthen the disintegration time and slow down the dissolution. The aim of this study was to compare four different brands of pregelatinized maize starch. The purpose was to find differences affecting the compressibility behavior. Also the effect of the mixing time of magnesium stearate for compression behavior of masses were studied. The brands investigated were C*PharmGel DC 93000, Lycatab® C, Starch 1500® and SuperStarch 200®. First mentioned was a reference product which is not manufactured any more. There was only one batch of the reference product but three batches from other products to be able to investigate also batch to batch variation. The characteristics studied from pregelatinized starch samples were bulk density, apparent density and true density, flowability, moisture sorption, moisture content, pH value, swelling volume and particle size. Also NIR, FTIR and Raman spectroscopy and X-ray powder diffraction method were used. Weight, tensile strength, dimensions, friability, disintegration time and moisture sorption were studied for tablets. The compressibility of the mass and elastic behavior of tablets was studied. Pictures of the tablets were also taken by scanning electron microscope. When the mixing time of magnesium stearate was increased from 2 minutes to 5 minutes, the compression pressure needed for pressing tablets for 80 N strength increased 200-700 N depending on the brand of pregelatinized maize starch. Based on the results the best alternative to replace C*PharmGel DC 93000 was chosen to be SuperStarch 200®. Scanning electron microscope pictures showed that C*PharmGel DC 93000 deviates from other qualities studied by being roundish and regular in shape. SuperStarch 200® and Starch 1500® reminded remarkably each other. Lycatab® C was the biggest in particle size and very irregular in shape. The differences found in tabletting followed the expectations based on the SEM-pictures. SuperStarch 200® showed to best compressibility in lowest strain strength and after C*PharmGel DC 93000 it was least sensitive for mixing time of the magnesium stearate. It also has least elastic recovery. The differences between SuperStarch 200® and Starch 1500® in compression properties were moderate but clear. Lycatab® C had clearly the weakest compression properties.
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(2011)Alphaviruses are positive-stranded RNA-viruses and they belong to the family of Togaviridae. Alphaviruses are spread by mosquitoes of family Aedes. Alphaviruses have spread on all continents except Antarctica. So far 29 alphaviral species have been identified and they can be divided in two groups, Old and New world viruses, by their geographical distribution and by diseases they cause. Chikungunya virus (CHIKV) is one of the Old World alphaviruses and it has been found in Africa and Asia. However, due to the global warming, Chikungunya is also spreading to southern Europe. In humans, it causes fever, headache, rash and joint pain, which can last for several years and be very painful. In small children, Chikungunya can cause neurological symptoms such as encephalitis. Genome of alphaviruses encodes for four structural proteins and four non-structural proteins (nsP), of which nsP3 contains a macro domain. Macro domains are conserved in most kingdoms of life but their function has not been elucidated. It has been shown that macro domains bind ADP-ribose and its derivatives and it has been shown that nsP3-protein has an important role in alphavirus replication. The aim of the study was to study the use of compounds which bind to macro domain protein as antiviral agents. 45 compounds were chosen for antiviral studies by molecular modeling. These compounds were expected to bind to macro domain proteins. In a competitive binding assay five compounds inhibited more than 50 % poly-ADP-ribose (PAR) binding to MDO1-macro domain protein, which was the protein on which the molecular modeling was performed. When the competitive binding assay was performed with SFV macro domain (nsP3), only one compound inhibited poly-ADP-ribose binding more than 50 %. In SFV-antiviral assay seven compounds had inhibition percentage higher than 50 %. In a CHIKV replicon assay five compounds had more than 50 % inhibition on replicon expression. We also studied possible inhibition mechanism by studying whether the compounds inhibit the virus to enter the cell. Almost all compounds included in this assay inhibited the virus entry to some extent. In general, the inhibition of PAR binding and antiviral activity did not correlate among the studied compounds. Even though compounds which had antiviral potency did not inhibit PAR binding to macro domains, potential antiviral agents were found which deserve further investigation as virus entry inhibitors.
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(2013)Brain-derived neurotrophic factor (BDNF) and the receptor mediating its effects, neurotrophin receptor TrkB, seem to have a role in the pathophysiology and treatment of mood disorders such as depression and mania. BDNF is a neurotrophin that regulates the differentiation and survival of neurons and mediates neuronal plasticity. Lithium and valproate are mood stabilizing agents that are commonly used to treat mania but their mechanism of action is still unclear. However, both acute and chronic lithium treatment have been shown to activate TrkB receptor in the rodent anterior cingulate cortex. It has also been shown that chronic lithium and valproate treatment increase the amount of BDNF in the rodent brain. The aim of the experimental part of this master's thesis was to find out what are the effects of lithium and valproate on TrkB receptor activation and on the amount of intracellular BDNF protein levels in vitro on embryonic day 18 (E18) rat primary cortical neurons. In addition, the possible role of neuronal maturation was investigated by conducting the experiments with neuronal cultures aged 7 and 21 days in vitro. The research methods included two different types of enzyme linked immunosorbent assays (ELISA), phospho-Trk ELISA and BDNF ELISA. Western blot was used to confirm the results. Therapeutically relevant concentration of lithiumchloride and valproate blocked BDNFinduced TrkB receptor phosphorylation in immature neurons aged 7 days in vitro. The effect of valproate was detected only with ELISA. In contrast, therapeutically relevant concentration of valproate increased TrkB receptor phosphorylation in immature neurons after one hour treatment. Lithium and valproate did not regulate TrkB receptor phosphorylation in mature neurons aged 21 days in vitro. However, therapeutically relevant concentration of lithium increased BDNF protein content in mature neurons after 24 hours treatment. Therapeutically relevant concentration of valproate did not alter BDNF protein levels. In conclusion, neuronal maturation does have a role on the effects of lithium and valproate on TrkB receptor activation and regulation of BDNF protein levels. It is possible that lithium and valproate are harmful to immature neurons through blocking BDNF-induced TrkB receptor phosphorylation. Since therapeutically relevant concentration of lithium did not activate TrkB receptor as has been shown previously in vivo it seems that certain developmental processes are essential for lithium-induced TrkB receptor activation.
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(2022)Ahmintahäiriö on epätyypillinen syömishäiriö, johon liittyy toistuvia ahmintakohtauksia, joiden aikana syödään hallitsemattomasti suuria määriä ruokaa, vaikka olo olisi jo epämiellyttävän täysi. Mantelitumake on ohimolohkon pohjukassa sijaitseva pelon ja tunteiden, mutta myös ruokahalun ei-homeostaattisen säätelyn, kannalta tärkeä rakenne. Mantelitumakkeen sentraalisen tumakkeen lateraalisen osan (CeL) solut säätelevät muun muassa ruoan palkitsevuutta ja tyydyttyneisyyden tunteen muodostumista ruokailun aikana. Suurin osa CeL:n kolinergisista hermoyhteyksistä on aivorungon pedunculopontisesta tegmentaalisesta tumakkeesta (PPT) projisoituvia hermoratoja. PPT:een kolinergisten hermopäätteiden in vivo optisen aktivaation on aikaisemmissa tutkimuksissa havaittu säätelevän opittua välttämiskäyttäytymistä, mutta optisen aktivaation vaikutusta ruoankulutukseen koe-eläimillä ei ole vielä tutkittu. Tämän pro gradu -tutkielman kokeellisen osan tavoite oli tutkia PPT:sta CeL:aan projisoituvan kolinergisen hermoradan in vivo optisen aktivaation vaikutusta ruoankulutukseen C57BL/6N -hiirillä. Optisen aktivaation vaikutusta tutkittiin sekä homeostaattiseen että ei-homeostaattiseen ruoankulutukseen. Ei-homeostaattisen ruoankulutuksen tutkimiseksi hiirille indusoitiin ahminnan kaltaista syömiskäyttäytymistä tarjoamalla hiirille rasvapitoista ruokaa viikoittain 24 tunnin jaksoissa. Tämän lisäksi tutkittiin ovatko optisen aktivaation vaikutukset kumottavissa asetyylikoliinireseptorien antagonistien mekamyyliamiinin tai skopolamiinin intraperitoneaalisella annostelulla. In vivo optisella aktivaatiolla ei havaittu olevan tilastollisesti merkitsevää vaikutusta ruoankulutukseen C57BL/6N -hiirillä. Tästä johtuen myöskään asetyylikoliinin antagonistien annostelun vaikutusta optisen aktivaation vaikutuksiin ei voitu arvioida. Tulokset viittaavat siihen, että PPT:een ja CeL:n välinen kolinerginen hermorata säätelee koe-eläimillä opittua välttämiskäyttäytymistä, mutta ei ruokahalua. Näin ollen on myös epätodennäköistä, että optisen aktivaation vaikutukset edellyttävät CeL:n proteiinikinaasi C deltaa ilmentäviä soluja. PPT:een kolinergisten hermosolujen vaikutus CeL:n toimintaa hermosolutasolla tulee kuitenkin varmistaa tarkemmissa jatkotutkimuksissa. Vaikka tutkimuksessa ei havaittu tilastollisesti merkitsevää vaikutusta, havaintoihin on kuitenkin suhtauduttava varauksella, sillä tutkimuksen toteuttamiseen liittyneet haasteet voivat rajoittaa havaittujen tuloksien luotettavuutta.
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(2023)The long-term use of antidepressants has increased significantly worldwide in recent decades. Deprescribing and the expertise related to it is an important part of the individual drug treatment optimization, the management of long-term diseases, the avoidance of adverse drug effects and the improvement of treatment outcomes. The aim of this thesis was to examine the information found in the statutory Summary of Product Characteristics (SmPC) and other key information sources for healthcare professionals about antidepressant deprescribing. A qualitative content analysis was conducted on SmPC (n=15) of the antidepressants (escitalopram, mirtazapine, sertraline, citalopram, venlafaxine) selected for the study, three national depression treatment guidelines (Suomalainen Lääkäriseura Duodecim: Depressio Käypä hoito -suositus, American Psychological Association APA: Practice Guideline for the Treatment of Patients with Major Depressive Disorder, United States and National Institute for Health and Care Excellence NICE: Depression in Adults: Treatment and Management, United Kingdom) and one decision supporting deprescribing tool (MedStopper). The content, quantity, and quality of information about antidepressant deprescribing varied between the information sources included in the study. However, the information found in the SmPC and the MedStopper -tool was mostly in line with the information found in the clinical practice guidelines included in the study. Most general information about antidepressant deprescribing or measures that can be used to guide deprescribing was found in the clinical practice guidelines. In all examined sources, antidepressants were recommended to be discontinued in a controlled manner by gradually reducing the dose. However, the recommended duration of the dose reduction varied in different information sources. A detailed dose reduction program was not found in most of the information sources. A detailed dose reduction program was found in only one clinical practice guideline (NICE) and the MedStopper -tool. The continuation of antidepressant treatment after remission and the timing of stopping the medication was discussed in only two clinical practice guidelines (APA and Käypä hoito). However, instructions for action if severe or intolerable discontinuation symptoms appears were found in almost all information sources. Only the clinical practice guidelines mentioned the recurrence of depression as a possible harm when stopping the medication and instructed how to act in the event of a possible relapse. Benefits related to antidepressant discontinuation was not mentioned in any of the examined information sources and only one clinical practice guideline (NICE) discussed barriers related to stopping antidepressants. The information found in individual information sources was insufficient and provided little support for healthcare professionals to guide deprescribing. Current key sources of information for healthcare professionals provide limited information and relatively imprecise guidance on antidepressant deprescribing and how to support the antidepressant discontinuation process. Better randomized clinical trials are needed to develop clearer and more extensive evidence-based guidelines for healthcare professionals on antidepressant deprescribing and to prevent unnecessary long-term antidepressant treatment and patient exposure to possible adverse drug effects.
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(2015)Both primary pharmacokinetic (PK) parameters, volume of distribution (Vd) and clearance (CL), undergo considerable developmental changes in infancy and childhood, necessitating compensatory changes in dosing regimens if therapeutic effect without toxicity is to be reached and maintained. Neonates exhibit higher body water content and decreased plasma binding capacity compared to adults, producing increased Vd values for many drugs. Due to immaturity of glomerular function and low metabolic enzyme expression, CL tends to be significantly decreased in neonates. Both Vd and CL undergo simultaneous but independent maturation during development. Performing pediatric clinical trials is challenging due to ethical and practical constraints. Modeling and simulation approaches, such as population pharmacokinetic (POP-PK) and physiologically based pharmacokinetic (PBPK) modeling, are beneficial aids in planning and performing clinical studies in children. The aim of the literary review is to assess the developmental phenomena that cause pediatric pharmacokinetics to differ from adults, the clinical consequences arising from these differences, and present ways to apply POP-PK and PBPK models in pediatric drug research. In the experimental work, two modeling approaches for the prediction of pediatric pharmacokinetics are explored. First, the performance of the commercial PBPK software Simcyp in simulating a drug-drug interaction between cyclosporine A (CsA) and ketoconazole (KTZ) is assessed. Second, a method for in vitro-in vivo extrapolation (IVIVE) of CL in children is developed and evaluated. The aim is to assess the suitability of both modeling methods in pediatric drug research. Simcyp predicted the general age-related trends in the CsA CL and CsA-KTZ interaction well for the most part. However, the values of the simulated CL terms and magnitude of the simulated interaction were significantly under- and overpredicted, respectively. Due to limited clinical data, though, Simcyp performance could not be fully validated. The method developed here for IVIVE of pediatric CL values yielded successful predictions in most cases, with in vitro data from hepatocytes performing slightly better when compared to microsomal data. Success in extrapolations performed for adults correlated well with success in the pediatric extrapolations. Therefore, in drug development, the method developed in this work would be most useful after adult PK data is available, before the first pediatric clinical studies.
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(2018)Tämä tutkimus esittelee kasviperäisen nanokuituselluloosageelin (NFC; GrowDex®) arvioinnin kolmiulotteisena (3U) kasvualustana rintarauhasen organogeneesin mallinnuksessa. Tutkimuksen tavoitteena oli tarkastella kasviperäisen in vitro -kasvualustan aiheuttamaa solusäätelyä normaalissa rinnan epiteelisessä solulinjassa, sekä selvittää rintakudoksen rauhasrakenteiden muodostumisessa keskeisen laminiini 111:n (LAM-111) alustaan lisäyksen mahdollisia hyötyjä viljelmille. Tutkimuksen koeasetelmassa NFC:n edustamaa kasvunicheä arvioitiin ihmisen rintaepiteelistä eristetyllä -ja tyvikalvon proteiinikontaktien säätelystä riippuvaisella MCF 10A -solulinjalla. Solujen in vitro -nicheympäristön verrokkimallinnuksessa hyödynnettiin epiteelisen tyvikalvon proteiiniympäristöä edustavaa proteiinirikasta Matrigel™-2,5U -kasvualustaa. Viljelynäytteistä tehtiin aikapisteittäin valomikroskooppiset -sekä histologiset hematoksyliini – eosiini (HE) morfologian arvioinnit, e-kadheriinin, vimentiinin ja β4-integriinin ilmentymisten vasta-aine-analyysit, sekä β1-integriinin, Bim:in ja c-FLIP-L:n lähetti-RNA:n reaaliaikaiset PCR-analyysit. Analyyseissä keskityttiin tarkastelemaan rintarauhasen epiteelin polarisoitumistapahtumassa havaittavaa solusäätelyä ja proteiinien eritystä. LAM-111 -lisän havaittiin edistävän jossain määrin NFC:ssä viljeltyjen sferoidien sisämorfologian kavitaatiota sekä eritettyjen proteiinien sijoittumista sferoidien pintarakenteisiin Matrigel™ -kontrollinäytteiden kaltaisesti, muttei yksinään riittänyt tuottamaan Matrigel™ :ssä havaittua viljelmien homogeenisyyttä. Kokeen natiivi-NFC:ssä sekä NFC-LAM-111:ssä kasvaneiden sferoidien PCR-analyyseissä havaittiin polarisaatiotapahtumaan liittyvää solusäätelyä viljelmien loppuvaiheessa päivänä 28, poiketen vastaavan PCR profiilin ilmentymisestä Matrigel™ -viljelmissä jo päivänä kolme. NFC -olosuhteissa havaittiin myös Matrigel™ -viljelmistä puuttuvia ylimääräisiä, epiteelisiltä vaikuttavia rakenteita, joiden määritteleminen vaatii lisätutkimuksia. NFC todettiin jäykkyyden suhteen helposti muokattavaksi sekä mahdollisesti kudoksen mekaanisia ominaisuuksia jäljitteleväksi 3U -kasvualustaksi. Tämän kokeen tuloksien perusteella muokkaamatonta NFC:tä voidaan ehdottaa soveltuvaksi kasvualustaksi tyvikalvoproteiinien säätelystä riippumattomille solutyypeille, sekä solutyypeille, jotka kykenevät tuottamaan ympärilleen oman kudostyypillisen proteiiniympäristönsä. Kliiniseen käyttöön kelpuuttavat standardivaatimukset täyttävä NFC vaikuttaa lupaavalta materiaalilta räätälöitävien in vitro -kasvualustojen suunnitteluun, ja mahdollisesti tarjoaa rakenneosiltaan tarkasti määritellyn, xenovapaan, ja proteiinilisillä eri solutyypeille säädettävän in vitro -kasvunichen tulevaisuuden jatkotutkimuksiin.
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(2024)MDMA is an illegal stimulant known for its empathy-enhancing effects. Its positive effects are mainly based on increasing the concentrations of monoamines such as serotonin (5-HT), dopamine (DA) and norepinephrine (NE). In addition to its positive effects, MDMA can cause adverse effects such as hyperthermia and neurotoxicity. Especially with long-term use, MDMA can cause serotonergic and dopaminergic neurotoxicity. In addition, there are also indications of MDMA-induced neurotoxicity in systems where gamma-aminobutyric acid (GABA) functions as the main neurotransmitter. Glutamate decarboxylase (GAD) 67 is an enzyme that synthesizes GABA from glutamate and is a specific marker for GABAergic cells. The amygdala is a nucleus in the brain that regulates anxiety and fear response. In addition to GABAergic interneurons, there are also glutamatergic cells in the basolateral nucleus (BLA) of the amygdala, however in the central nucleus (CeA) there are only GABAergic cells. Disturbances in the GABAergic system can predispose to psychiatric diseases such as anxiety. The aim of thisstudy was to investigate the effects of MDMA (20 mg/kg) on the number of GAD67-positive cells in two nuclei of the mouse amygdala, BLA and CeA. In addition, this study aimed to examine the importance of the dose (4 or 16 injections) for neurotoxicity and the duration of the effects (2, 7 or 30 days). Adolescent wild type mice were divided into 12 groups according to the treatment (MDMA or saline), dose and timepoint. After euthanasia, the brain sections at the level of the amygdala were collected and stained with an immunohistochemical method and imaged using a confocal microscope. This study showed that MDMA reduced the number of GAD67-positive cells in the BLA when mice were given a total of 4 injections. This effect lasted up to 30 days. In contrast, MDMA did not reduce the number of GAD67-positive cells in the BLA in mice that were given 16 injections. Also, MDMA did not decrease the number of GAD67-positive cells in the CeA, regardless of dose. Statistical significance could have been improved, for example, by using more mice or analysing more sections from each individual animal. It is important to continue studying the effects of MDMA to better treat and prevent its adverse effects. In addition, increased understanding would urge users to exercise caution when using MDMA.
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(2012)Elucidation of transporter- and/or metabolic enzyme-mediated drug interactions is important part of early drug development. However the knowledge about clinical consequences of transporter-mediated drug-drug interactions is still limited and more investigation is needed to improve our understanding. MDR1 transporter, widely distributed on the pharmacokinetic barriers in the body (e.g. intestine) and has been shown no limit the bioavailability of drugs. Substrates of MDR1 are exposed to limited intestinal drug absorption and intestinal drug-drug interactions due to inhibition of the transporter. In predicting the clinical significance of an interaction, the principal obstacle has been the limited ability to appropriately scale the preclinical data into in vivo situation. In vitro-in vivo correlations on the extent of MDR1's influence on absorption and standardized predicting methods for drug-drug interactions using the inhibitory constants (IC50 and Ki) would greatly increase the value of in vitro studies. Current in vitro and in silico methods for prediction of the influence of MDR1 on intestinal absorption and related drug-drug interactions are discussed in the literature review. In addition, the latest regulatory draft guidances (FDA, EMA) are reviewed. Aliskiren has been shown to be a sensitive MDR1 substrate in vivo and high affinity substrate for the transporter in vitro. The objective of the experimental work was to study the MDR1-mediated transport of aliskiren and the related drug-drug interactions in vitro and in silico. Vesicular transport assay was used to obtain kinetic parameters for aliskiren (Km and Vmax) and inhibitor potencies (IC50) for ketoconazole, verapamil, itraconazole and its metabolite hydroxyitraconazole. Ki was further calculated for itraconazole and hydroxyitraconazole. Aliskiren showed high affinity to MDR1 transporter with a Km value 5 µM, consistent to what was reported previously in different assay systems. The interactions between aliskiren and the inhibitors in vitro correlated to the observed interactions in vivo in humans. In addition, hydroxyitraconazole was shown to be a potent inhibitor of MDR1-mediated transport of aliskiren in vitro. This suggests that hydroxyitraconazole may contribute to the pronounced interaction observed between aliskiren and itraconazole in a clinical interaction study. A compartmental absorption and transit (CAT) model with added enterocyte compartments and MDR1 efflux was used to describe the influence of MDR1 on intestinal absorption of aliskiren in humans. The integration of kinetic parameters (Km) from in vitro studies requires further optimization on how to describe the intracellular drug concentrations in the model. Aliskiren is however suitable MDR1 probe substrate to be used in in vitro and in vivo trials in humans and therefore gives a good basis for developing vitro-in vivo predictive models.
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(2017)Multidrug resistance protein 1 (MDR1, p-glycoprotein) belongs to the ATP-binding cassette transporter family and it's encoded by ABCB1/MDR1 gene. It is a protein which transports many different kinds of compounds out of cells, for example from endocytes to the lumen with the use of energy from ATP. MDR1 is there for a restrictive factor for several orally administered drugs. It`s important to have knowledge about MDR1-inhibitors, in order to avoid harmful drug-drug and food-drug interactions that might affect medical treatment. The purpose of this master's thesis was to optimize an in vitro MDR1-vesicle uptake method and use it to screen inhibitors from compound libraries. To optimize the method, the effect of cholesterol loading on ATP-dependent transport of test substrate N-methylquinidine (NMQ) was evaluated, transport kinetics of the vesicles and kinetics of known inhibitors were also tested. With the optimized method, screening was done with a library of 25 food additives and a library of 42 synthetic compounds. The chemical structures of the synthetic compounds were analyzed manually in order to find factors that could explain their ability to inhibit MDR1. Only one inhibitor was found among food additives: curcumin. Other additives didn't increase or decrease the ATP-dependent transport of NMQ. Several inhibitors were found from the library of synthetic compounds, also a couple of compounds were found to increase the active transport of NMQ. Results indicate, that the additives used in this study have low risk to cause MDR1 mediated interactions, if curcumin is excluded. The inhibitory effect of curcumin should be investigated in in vivo-situation, because vesicle-based in vitro-results have tendency to overestimate results. Screening results of the synthetic compounds gives more confirmation to the usefulness of the screening method. The MDR1-inhibition screening method described in this Master`s thesis is valid, and it can be used to screen different compound libraries for MDR1-inhibitors. In the future it could be used to screen different kinds of compounds, which might end up inside humans and cause interactions with drugs.
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(2011)Drug-drug interactions occur when a drug or a drug metabolite modifies the activity of a drug metabolizing enzyme. As a result the concentration of active drug can be too low to be effective or too high and possibly toxic. This is an increasing problem in drug therapy where polypharmacy is rather common today. Therefore, in drug discovery and development significant efforts have been made in order to predict such interactions in advance and avoid them, or at least minimize them. This study is focused on medetomidine, a drug metabolized by UDP-glucuronosyltransferases (UGT). The aim of the study was to find inhibitors for medetomidine glucuronidation. Also the mechanism of possible inhibition was of interest. It is already common to test interactions of a given enzyme substrate with other enzymes of the same family either in phase I or phase II of drug metabolism in humans. It is less common, however, to examine such interactions between enzymes of two different families. In the present study it is tested if the compounds which are possible inhibitors of cytochrome P450 monooxygenase (CYP) also inhibit UGTs. Inhibition of glucuronidation was studied with HPLC method previously developed for medetomidine glucuronidation. First glucuronidation of medetomidine was studied without inhibitor compounds. After that the impact of three possible inhibitors on medetomidine glucuronidation was studied and results were compared with the initial results. Three compounds were found to inhibit glucuronidation of medetomidine. Also an interesting change in UGT's enzyme kinetics after the binding of inhibitor was discovered. It is interesting that same compounds could inhibit both CYPs and UGTs. The results revealed that if a CYP and a UGT could bind for the same compound, it is also likely that structural analogues of that compound will interact with both enzymes. In drug discovery and development it is important to take into account both CYP-enzymes and less studied UGTs, and their possible interactions.
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(2024)Medication safety is critical in health and social care, and community pharmacies significantly participate in managing medication safety risks. The information systems in community pharmacies are pivotal, yet understudied tools supporting this task. This study investigates community pharmacy information system-related medication safety incidents reported by Finnish community pharmacies, focusing on how information systems act as defences or contributing factors to such incidents. The study is based on 1222 information system-related medication safety incident reports from the HaiPro system between October 2022 and September 2023. The structured fields of the incident reports were analysed with descriptive quantitative analysis using Microsoft Excel. An abductive content analysis was performed on narrative texts of the incident reports to identify information system-related risks or defences in the incidents. Reason's human error theory acted as a theoretical framework in this study. Results indicated that in 96% (n=1168) of the incidents, information systems were contributing factors, primarily during the selection of medicinal products for dispensing (n=945). The most common issue was the community pharmacy information system not offering generic substitutes for market-exited medicinal products (n=282). Another notable issue was compatibility problems between community pharmacy information systems and Electronic Patient Record (EPR) systems or between different community pharmacy information systems (n=154). Conversely, barcode recognition emerged as the most reported defence, preventing errors in 96% (n=52) of defensive cases (n=54). The study underscores the dual role of community pharmacy information systems in medication safety both as defences and contributing factors. It highlights the need for continuous system development and possible regulatory changes to enhance their effectiveness as defences. Future research should explore these systems' roles using alternative methodologies to address underreporting and better quantify their impact on medication safety.
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(2019)Conditional reimbursement was introduced in Finland in January 2017 as a temporary addition in the Finnish Health Insurance Act. An agreement can be made between a marketing authorisation holder (MAH) and the Pharmaceuticals Pricing Board. Conditional reimbursement status can be allowed for a medicinal product if the drug is addressing unmet medical need and there are uncertainties associated to the medicinal product considering i.e. therapeutic value or cost-effectiveness, when traditional reimbursement procedures are not suitable. Risk-sharing is an essential part of the agreements and the results are monitored. Types of agreements are divided into financial- and performance-based agreements. Conditional reimbursement in Finland has not yet been studied in a large extent since its introduction. The aim of this study was to create an overview of the medicinal products with conditional reimbursement in Finland, how the unmet medical need is addressed, and which treatment options are available. Also, benefits and risks of the different stakeholders of risk-sharing agreements (RSA), why these agreements are worth to implement, earlier experiences from the European Economic Area (EEA) countries and what pharmaceutical companies should consider prior to negotiations were investigated. A document analysis was performed for investigating the medicinal products with conditional reimbursement status in Finland. A systematic literature review was conducted for collecting information and earlier experiences of RSAs and managed entry agreements (MEA) in the EEA-countries. On February 1st, 2019 there was 19 medicinal products with conditional reimbursement in Finland. These drugs are successfully addressing unmet medical need. All stakeholders of RSAs encounter benefits and risks of these agreements but the MAH is the one carrying the largest responsibilities and risks. Risk-sharing agreements gained in popularity since the early 2000s in the EEA-countries. There is no golden standard for types of agreements made but MEAs are enshrined in legislation in most countries. The pharmaceutical company should as early as possible start shaping details and collect information of the product for which conditional reimbursement will be proposed to. Negotiations might be challenging, but the aim is an agreement in which both the MAH and the payer are content with. Finland is following a similar trend as other EEA-countries, since most of the medicinal products with conditional reimbursement are oncology medicines. The use of the drugs has been limited through reimbursement number codes for certain patients who are most likely to benefit from the treatment. Rationales for introducing RSAs in EEA-countries were similar, e.g. working with finite resources, improving access, reducing uncertainty and prices, managing budget impact and improving cost-effectiveness. It seems like Finland is unique by the temporary introduction of conditional reimbursement in legislation and in other countries it has been introduced as permanent. Starting the preparations early for negotiations could save time and resources. When a RSA is made and the medicinal product shows the benefits expected, this is the ideal situation where all stakeholders benefit.
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