An evaluation of test methods in the chemotherapy of influenza A virus infections.

The principal aim of this study was to compare a number of in vitro and in vivo systems, to establish the most suitable methods for detecting and quantitating anti-influenzal activity, and with these methods to compare the activity of different compounds. Eight strains of virus, two from each of the 4 sub-types, were used. For in vitro work two primary cell lines, chick embryo and calf kidney cells, and the allantois-on-shell system (AOS) were compared. Antiviral activity was assessed by yield reduction determination under either single or multiple cycle conditions, and by plaque inhibition and reduction tests. Chick tracheal organ cultures were also used on a limited basis to detect activity. For in vivo work mice were used, with activity determined by reductions in virus content of the lungs of infected mice, the results of which were compared with those of mortality tests. The effect of mouse lung passage history of virus on the results was also examined. The three in vitro systems used all proved satisfactory, with the AOS system the easiest to prepare. Plaque inhibition and reduction tests proved useful for detecting and quantitating activity, although single cycle tests were more suitable for comparing the sensitivity of different strains and the results obtained with different cultures. Multiple cycle tests gave rather variable results. In vivo the titrations of the virus content of lungs proved satisfactory for detecting and quantitating activity, and good agreement was obtained with mortality tests. With mouse lung passage history variation in results occurred, and highly adapted strains were found to be most suitable for comparative work. A total of 60 compounds were examined for activity, out of which only amantadine hydrochloride and Ribavirin proved sufficiently active for further work. The activity of amantadine hydrochloride varied in different systems and with different strains of virus. With Ribavirin minor variations occurred between systems, but all 8 strains examined were similar in sensitivity. Overall it was impossible to say which compound was more active, but the differences in activity between the two compounds were generally not great

Design and performance testing of quantitative real time PCR assays for influenza A and B viral load measurement

Background: The antiviral effect of anti-influenza drugs such as zanamivir may be demonstrated in patients as an increased rate of decline in viral load over a time course of treatment as compared with placebo. Historically this was measured using plaque assays, or Culture Enhanced Enzyme Linked Immunosorbent Assay (CE-ELISA). Objectives: to develop and characterise real time quantitative PCR (qPCR) assays to measure influenza A and B viral load in clinical samples, that offer improvements over existing methods, in particular virus infectivity assays. Study design: The dynamic range and robustness were established for the real time qPCR assays along with stability of the assay components. Cross validation of the real time PCR assays with CE-ELISA was performed by parallel testing of both serial dilutions of three different subtypes of cultured virus and a panel of influenza positive throat swab specimens. Results: the assays were specific for influenza A and B and the dynamic ranges were at least seven logs. The assay variability was within acceptable limits but increased towards the lower limit of quantification, which was 3.33 log10 viral cDNA copies/ml of virus transport medium (ten viral RNA copies/PCR). The components of the assay were robust enough to withstand extended storage and several freeze–thawcycles. For the real time PCR assays the limit of quantification was equivalent to the virus infectivity cut off, which equates to a 93-fold increase in sensitivity. Conclusion: Well characterised real time PCR assays offer significant improvements over the existing methods for measuring the viral load of strains of influenza A and B in clinical specimens

The Effects of Sex and Strain on <i>Pneumocystis murina</i> Fungal Burdens in Mice

Many preclinical studies of infectious diseases have neglected experimental designs that evaluate potential differences related to sex with a concomitant over-reliance on male model systems. Hence, the NIH implemented a monitoring system for sex inclusion in preclinical studies. Methods: Per this mandate, we examined the lung burdens of Pneumocystis murina infection in three mouse strains in both male and female animals at early, mid, and late time points. Results: Females in each strain had higher infection burdens compared to males at the later time points. Conclusion: Females should be included in experimental models studying Pneumocystis spp

Genotypic and phenotypic sensitivity of viral isolates, in patients failing to AZT-3TC-141W94

info:eu-repo/semantics/nonPublishe

Stress and anxiety scores in first and repeat IVF cycles: a pilot study.

BACKGROUND: The role of stress in reproduction, particularly during treatment for infertility, has been of considerable interest; however, few studies have objectively measured stress and anxiety over the course of the IVF cycle or compared the experience of first-time and repeat patients. METHODS: This prospective cohort pilot study enrolled 44 women undergoing IVF at a university-based clinic to complete the State-Trait Anxiety Inventory (STAI), Perceived Stress Scale (PSS) and Infertility Self-Efficacy Scale (ISES) at three time points prior to ovarian stimulation (T1), one day prior to oocyte retrieval (T2), and 5-7 days post embryo transfer (T3). RESULTS: Mean STAI State scores were significantly elevated at all three time points (p<0.01). STAI State and PSS mean values did not change over time and did not differ in first-time vs. repeat patients. Self-efficacy (ISES) scores declined over time, with a greater decline for repeat patients. Of the 36 women who completed a cycle, 15 achieved clinical pregnancy. Using logistic regression modeling, all scores at T2 were correlated with pregnancy outcome with lower scores on the STAI State and PSS and higher scores on the ISES associated with higher pregnancy rates. CONCLUSIONS: Stress and anxiety levels remained elevated across all cycles. Women with lower stress and anxiety levels on the day prior to oocyte retrieval had a higher pregnancy rate. These results emphasize the need to investigate stress reduction modalities throughout the IVF cycle

Mutations in HIV-1 reverse transcriptase during therapy with abacavir, lamivudine and zidovudine in HIV-1-infected adults with no prior antiretroviral therapy

SCOPUS: ar.jinfo:eu-repo/semantics/publishe