Browsing by Subject "Chlamydia pneumoniae"
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(2011)Based on earlier studies, it was known that certain 2,1,3-benzoxadiazole molecules were active against Chlamydia pneumoniae -bacterium. The goal of this study was to gather more information about structure-activity relationships of the 2,1,3-benzoxadiazole molecules. The purpose of a research was to develop a synthesis route for 2,1,3-benzoxadiazole molecules and build a molecular library based on the results. Synthesized molecules were tested against Chlamydia pneumoniae -bacterium and Leishmania donovani -parasites. Chlamydia pneumoniae -bacterium causes acute upper and lower respiratory tract infections such as bronchitis. The symptoms of acute inflammation of the Chlamydia pneumoniae can vary considerably. Chlamydia pneumoniae can also cause chronic infections. Chronic infections are linked to economically important diseases such as atherosclerosis and asthma. Leishmaniosis is the second most common parasitic disease in humans after malaria. Leishmania donovani -parasite can cause fatal visceral leishmaniasis. Leishmaniasis kills more than 50 000 people each year. In recent years, medical treatment for leishmaniasis has encountered many problems. Some of the medicines have lost their efficiency and some of them cause serious side effects. Fully functional synthesis route was developed for a 2,1,3-benzoxadiazole derivatives. 4-Amino-2-nitro benzoic acid was used as a starting material. With a oxidative ring-closure reaction 2,1,3-benzoxadiazole-5-carboxyl acid was obtained. 2,1,3-benzoxadiazole-5-carbonitrile was synthesized from the corresponding carboxyl acid via amide intermediate. When 2,1,3-benzoxadiazole-5-carbonitrile was treated with hydroxylamine hydrochloride, carboximidamide was obtained, which was a common intermediate for all the final products. At the final stage N'-hydroxy-2,1,3-benzoxadiazole-5-carboximidamide was let to react with either phenyl isocyanate or phenyl isothiocyanate to give the final products. Development of a synthesis route proved to be challenging so at the end three final products were synthesized. One of the final products was tested against C. pneumoniae -bacterium in the Åbo Akademi, Turku. The test compound did not contain 2,1,3-benzoxadiazole ring structure and the result was in line with expectations. The compound was not active against C. pneumoniae at low concentrations and the results showed that 2,1,3-benzoxadiazole ring is an important part of the activity. Two of the final products were tested against Leishmania donovani parasite in Israel. Only one of the molecules contained 2,1,3-benzoxadiazole ring. The results of the bioactivity test were very encouraging. Compounds were active against the parasite at low concentrations. However, the 2,1,3-benzoxadiazole compound was more active. Also the result of Leishmania test shows that 2,1,3-benzoxadiazole ring structure was found to be an important part of the activity.
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(2020)Making the treatment of these infections even harder is the fact, that Chlamydia pneumoniae can produce persistent forms of itself, which are immune to antibiotic treatment. When the bacteria sense a stress factor, for example the presence of a β-lactam antibiotic or interferon γ, they start producing these persistent forms called aberrant bodies. When the stress factor is removed, the bacteria can switch back to their replicating form and start infecting the tissues again. It is also known, that C. pneumoniae bacteria will trigger persistence when the bacteria migrate from lung epithelia into monocytes. Interestingly the onset of this mode of persistence does not require any other triggers besides the invasion of the monocyte. These persistence mechanisms enable latent, quiet, and recurring infections. This master’s thesis aimed to study the coculture of lung epithelial (HL cells) and monocytes (THP-1 cells), and by utilising the magnetic separation method presented by Kortesoja et al, to find a positive control compound in the prevention of Chlamydia pneumoniae internalisation into the THP-1 cells for said protocol. In these cocultures the inhibitory effect of different compound groups such as lignans present in Schisandra chinensis plant, MAPK-inhibitors, and β2,2-amino acid derivatives in C. pneumoniae migration from HL cells to THP-1 cells was assessed. Statistic relevance was observed in JNK inhibitor SP600125, MAPKAP-kinase-2 inhibitor SB203580, and ERK1/2 inhibitor FR180204 compounds. These compounds inhibited the internalisation of Chlamydia pneumoniae into THP-1 cells in the cell coculture by 61,05 ± 16,63 % (p = 0,0001), 54,06 ± 16,02 % (p = 0,0002), and 36,76 ± 10,33 % (p = 0,009) respectively. SP600125 and SB 203580 compounds also had an inhibitory effect on the internalisation of C. pneumoniae into the THP-1 cells in a cell monoculture (39,98 ± 18,92 %, p = 0,026 and 37,89 ± 19,47 %, p = 0,035 respectively), whereas FR180204 had no statistical significance, even though it inhibited the internalisation of C. pneumoniae into the THP-1 cells in cell monoculture by 27,53 ± 21,17 %. From the compounds used in the experiments, only MAPK inhibitors had an effect in inhibiting the C. pneumoniae internalisation into the THP-1 cells. The most potent compound in said inhibition was the JNK inhibitor SP600125. JNK pathway has been thought to take part in chlamydial infections but only little research has been done. The results of this master’s thesis’ experiments support the thought of JNK enzyme taking part in chlamydial infections but determining how exactly it affects the infection cycle of C. pneumoniae bacteria still needs further investigation.
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(2023)Verensiirtoja tarvitaan monissa erilaisissa tilanteissa, kuten akuutissa verenhukassa, leikkauksissa ja sairauksien hoidoissa. Verivalmisteiden laajan käytön takia, on tärkeää varmistaa veriturvatoiminnalla niiden laatu sekä turvallisuus. Olennainen osa verivalmisteiden laadunvalvontaa on seuloa veren välityksellä leviäviä taudinaiheuttajia. Suomessa veren välityksellä leviävien tautien leviämisen riski on lähes olematon tarkan laadunhallinnan ansioista. Verenluovutusajankohtana oireettomat taudit aiheuttavat kuitenkin riskin laadunhallinnalle. Koska krooninen Chlamydia pneumoniae -infektio voi olla oireeton, on tärkeää tutkia taudin kykyä levitä verivalmisteiden välityksellä. Tätä ennen on kuitenkin tutkittava, löytyykö verivalmisteista edes kyseistä bakteeria. C. pneumoniae on gram-negatiivinen solunsisäinen bakteeri, joka aiheuttaa ihmisillä erilaisia akuutteja hengitystieinfektioita, kuten keuhkokuumetta, nielutulehdusta ja sinuiittiä. Vaikka suurin osa tartunnoista on oireettomia tai lieväoireisia, voi infektio muuttua hoitamattomana krooniseksi. Akuutissa infektiossa C. pneumoniae infektoi pääasiassa keuhkojen epiteelisoluja sekä alveolaarisia makrofageja. Infektion pitkittyessä bakteeri voi levitä muihin elimistön soluihin valkosolujen välityksellä. Tämä bakteerin kyky aiheuttaa kroonista infektiota sen muuttuessa persistenttiin muotoon tekee bakteerista hyvin menestyvän. Tämän tutkimuksen tavoitteena oli selvittää, kuinka paljon C. pneumoniae -bakteeria esiintyy suomalaisessa luovutusveressä. C. pneumoniae -bakteerin DNA:n tunnistamiseen kokoverestä käytettiin kolmea eri PCR-menetelmää: kvantitatiivista PCR:ää, sisäkkäistä PCR:ää ja digitaalista pisara PCR:ää. Työn ensimmäinen vaihe oli suunnitella ja optimoida nämä kolme PCR-menetelmää. Menetelmien pystyttämisen jälkeen 40 verinäytettä tutkittiin kyseisillä PCR-menetelmillä. Lisäksi samoista verinäytteistä määritettiin C. pneumoniae spesifisen vasta-aineen, immunoglobuliini G:n, määrät ELISA-immunomäärityksellä. Verinäytteitä tutkittaessa C. pneumoniae -bakteerin esiintyvyys suomalaisessa luovutusveressä oli hyvin pieni. Vain kahden näytteen (2/40) epäiltiin olevan mahdollisesti positiivisia, sillä nämä antoivat mahdollisia positiivisia tunnistuksia vähintään kahdessa PCR-ajossa. C. pneumoniae spesifisten IgG vasta-aineiden esiintyvyys oli suurempi; näytteistä 50 % oli igG positiivisia. IgG vasta-aineiden esiintyvyyden ei todettu korreloivan iän tai sukupuolen kanssa. Aiemmissa tutkimuksia C. pneumoniae -bakteerin esiintyvyys luovutusveressä on vaihdellut 7–46 %:n välillä. Bakteerin esiintyvyyden jäädessä hyvin alhaiseksi on mahdollista, että PCR-menetelmien detektioherkkyys ei riittänyt tässä tutkimuksessa tunnistamaan toistettavasti mahdollisia positiivisia näytteitä. Näin ollen PCR-menetelmien lisäoptimointi olisi tarpeen.
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