Epidemiological and Biological Evidence for a Compensatory Effect of Connection Domain Mutation N348I on M184V in HIV-1 Reverse Transcriptase

Background. The connection domain mutation N348I confers resistance to zidovudine (AZT) and is associated with the lamivudine (3TC) mutation M184V. We explored the biochemical and virological influence of N348I in the context of M184V. Methods. Genotypic resistance data for patients receiving monotherapy or dual therapy with AZT, lamivudine (3TC), or AZT/3TC were analyzed. Rates of N348I emergence were compared between treatment groups. Mutant reverse transcriptases (RTs) containing M184V and/or N348I were generated to study enzymatic and virological properties. Results. We included 50 AZT-treated, 11 3TC-treated, and 10 AZT/3TC-treated patients. N348I was observed in 3 (6%), 0, and 4 (40%) of these patients, respectively. The rate of N348I emergence was increased by 5-fold in the AZT/3TC group (11.7 instances [95% confidence interval {CI}, 3.2-30.1 instances] per 100 person-years of receipt of AZT), compared with the rate noted for the AZT group (2.3 instances [95% CI, 0.4-6.8 instances] per 100 person-years of receipt of AZT; P = .04). Biochemical data show that N348I can partially compensate for the diminution in processive DNA synthesis and the reduction in AZT excision associated with M184V. Furthermore, virological analyses demonstrate that N348I confers low-level resistance to AZT and partly restores the reduced RT activity of the M184V variant. Conclusion. In vivo selection of N348I is driven by AZT and is further facilitated when 3TC is coadministered. Compensatory interactions between N348I and M184V help to explain these finding

HIV-1 Reverse Transcriptase Connection Domain Mutations: Dynamics of Emergence and Implications for Success of Combination Antiretroviral Therapy

Background. Factors promoting the emergence of human immunodeficiency virus type 1 (HIV-1) reverse transcriptase (RT) connection domain mutations and their effect on antiretroviral therapy (ART) are still largely undetermined.We investigated this matter by analyzing genotypic resistance tests covering 400 amino acid positions in the RT of HIV-1 subtype B viruses and corresponding treatment histories and laboratory measurements. Methods. The emergence of connection domain mutations was studied in 334 patients receiving monotherapy or dual therapy with thymidine analogues at the time of the genotypic resistance test. Response to subsequent combination ART (cART) was analyzed using Cox regression for 291 patients receiving unboosted protease inhibitors. Response was defined by ever reaching an HIV RNA level <50 copies/mL during the first cART. Results. The connection domain mutations N348I, R356K, R358K, A360V, and A371V were more frequently observed in ART-exposed than ART-naive patients, of which only N348I and A360V were nonpolymorphic (with a prevalence of <1.5% in untreated patients). N348I correlated with M184V and predominantly occurred in patients receiving lamivudine and zidovudine concomitantly. A360V was not associated with specific drug combinations and was found to emerge later than M184V or thymidine analogue mutations. Nonpolymorphic connection domain mutations were rarely detected in the absence of established drug resistance mutations in ART-exposed individuals (prevalence, <1%). None of the 5 connection domain mutations associated with treatment showed a statistically significant effect on response to cART. Conclusions. Despite their frequent emergence, connection domain mutations did not show large detrimental effects on response to cART. Currently, routine implementation of connection domain sequencing seems unnecessary for developed health care setting

HIV-1 reverse transcriptase: novel mechanisms of inhibition and drug resistance

The reverse transcriptase (RT) enzyme of human immunodeficiency virus 1 (HIV-1) is an RNA- and DNA-dependent DNA polymerase that also exhibits RNase H activity. The polymerase and RNase H active sites of RT are structurally linked through the connection domain. RT is a major antiretroviral target but the development of viral resistance often leads to therapy failure. Genotyping protocols detect mutations in the polymerase active site that confer resistance to nucleoside analogue RT inhibitors such as zidovudine (AZT). It has been shown however, that mutations outside of this region, such as the N348I substitution in the connection domain, also confer resistance to AZT. Here, we have investigated the mechanism of N348I drug resistance. Our biochemical results have shown that the N348I mutation affects drug susceptibility by reducing nucleic acid substrate binding in the RNase H domain of RT. The N348I mutation also compensates for enzymatic deficits introduced by other resistance-conferring mutations, thus providing a rationale for its selection pattern in vivo.Additionally, we have investigated the mechanism through which INDOPY-1, a newly discovered antiretroviral agent, disrupts RT function. Although INDOPY-1 is not a nucleoside analogue, it can compete with incoming nucleotides and select for mutations at the site of nucleotide binding. Based on these observations, we propose that this antiretroviral agent belongs to a new class of RT inhibitors that we name "Nucleotide-competing RT Inhibitors". Finally, cellular ATP was shown to enhance the potency of INDOPY-1, a property never before seen with any other RT inhibitors. Based on the biochemical properties of this interaction, we propose to describe ATP as an "enhancer" of INDOPY-1-mediated RT inhibition. ATP enhances the binding of INDOPY-1 to RT by "capping" the inhibitor in the polymerase active site.Work presented in this thesis characterizes a novel mechanism of resistance to clinically approved RT inhibitors. It also describes, for the first time, a new class of RT inhibitors that function through a unique mechanism of action.La transcriptase inverse (RT) du VIH-1 est une polymérase d'ADN et d'ARN qui est aussi capable de dégrader l'ARN viral durant la polymérisation. Le domaine de connextion de la RT crée un lien entre le site actif de la polymérase et le site actif d' RNase H de cette enzyme. La RT est une cible majeure de la thérapie contre le SIDA. Mais, à cause du taux de mutation élevé du virus, le développement de résistance aux médicaments est rapide, ce qui engendre la neutralisation des effets avantageux des thérapies antivirales. Les analogues de nucléosides, comme zidovudine (AZT), sont souvent utilisés durant la thérapie anti-SIDA. Les tests génotypiques qui détectent la résistance virale incluent seulement le domaine de la polymérase de la RT. Par contre, il a été démontré que des mutations dans les domaines de la connextion, par example le mutation N348I, peuvent causer la résistance à AZT. Nous avons étudié le mécanisme de résistance à la mutation N348I. Nos resultats biochimiques montrent que N348I a un effet négatif sur l'affinité de l'ARN pour le site actif d'RNase H. Nous montrons aussi que la mutation N348I peut compenser pour des domages causés par d'autres mutations. Ceci peut expliquer l'apparence de cette mutation in vivo. Nous avons aussi étudié le mécanisme d'action d'INDOPY-1, un nouveau agent inhibatoire de la RT. Malgré que l'INDOPY-1 n'est pas un analogue de nucléoside, cet agent peut entrer en compétition avec les nucléotides et les mutations de résistance sont selectionnées dans le site d'association des nucléotides. C'est ainsi que nous avons proposé que l'INDOPY-1 appartient à une nouvelle catégorie d'inhibiteurs que nous nommons «Nucleotide-competing RT inhibitors». Un autre trait caractéristique de l' INDOPY-1 est que sa capacité d'inhibition peut être augmentée par l'ATP cellulaire. Basé sur ceci, nous décrivons l'ATP comme étant le «renforceur» de l'INDOPY-1. Ce mécanisme de renforcement se produit lorsque l'ATP «encapsule» l'INDOPY-1 dans le site actif de la polymérase de la RT.En conclusion, nous avons characterisé un nouveau mécanisme de résistance aux analogues de nucléosides. Nous avons aussi découvert le premier composé d'une nouvelle classe d'agents inhibatoires de la RT

Assessment of the hospital information system in compliance with Certification Commission for Healthcare Information Technology standard at Isfahan University of Medical Sciences' academic hospitals

Introduction: Hospital information system (HIS) plays an important role in improving the quality of treatment in hospitals. These systems are considered as an information system that can have a great influence on the efficiency and effectiveness of hospital management. Assessment system as one of the most important debates in the hospital management system has received great emphasis. The present study was aimed to assess HISs of Isfahan academic hospitals and was performed using Certification Commission for Health Information Technology (CCHIT) standard. Methods: This study is an applied descriptive cross-sectional study, in which 11 academic HISs of Isfahan University of Medical Sciences were surveyed by using a CCHIT standard checklist with three areas (information management, patient management, and technical management). Obtained data were analyzed with SPSS software V. 18 (IBM), and descriptive statistics was used to examine measures of central tendencies. Results: Data analysis revealed that the mean score of information management, patient management, and technical management areas in compliance with CCHIT standard were 66.1, 63.5, and 64.6 percent, respectively. Conclusions: According to the results of this study, it can be expressed that the criteria of HIS has been implemented in a rather favorable way. Hence, to achieve the desired mode, planning must be done on designing systems to increase the efficiency of information management, patient management, and software and technical infrastructures

Cardiovascular diseases risk factors in people with normal body mass index and waist circumference

Background and Aim: Considering the importance of obesity and regarding that only few studies in the field of normal anthropometrics are available in the country, the present .study was conducted to survey cardiovascular diseases (CVD) risk factors in people with normal body mass index and waste circumference. Materials and Methods: Data of this cross-sectional study was obtained from the 1st phase of Isfahan Healthy Heart Program (IHHP), which is a communo-intervening plan on 3718 individuals aged over 19 years, having normal Body Mass Index (BMI) and waist circumference (WC) in Isfahan, Najaf-abad, and Arak. In order to evaluate the association between the quartiles of BMI and WC with CVD risk factors, multiple logistic regression was applied. Results: Out of the population of the study, 2859 were males and 859 females with mean age 34.29±14.29 yrs. The odd ratio (ORs) of dislipidemia in the biggest quartile of BMI in males and females was 1.84 [1.45-2.33] (P<0.001) and 1.56[1.05-2.30] (P<0.05), respectively. Odds ratio of at least two risk factors in the highest W.C. quartile was 2/6 [1.45-4.65] (P=0/001). and In men, the odds ratio of at least one risk factor in the highest WC and BMI quartile were 1.42 [1.12-1.817] (P=0.001) and 1.78[1.90-2.27] (P=0.002), respectively compared with the first quartile. Conclusion: Although normal borderline levels of BMI and WC are used to predict CVD risk factors, but lower borderline levels of these Indexes can also be referred to as a CVD risk predictor

Comparing the Effect of Alendronate and Vitamin D Administration on Lumbosacral Fusion and Severity of Low Back Pain in Patients After Posterior Lumbar Fusion Surgery: A Randomized Clinical Trial

Background and purpose: Bone fusion is a dynamic process and availability of calcium and balance of vitamin D can be effective in post spinal cord fusion. There are contradictory results on this issue, so, we decided to compare the effect of administration of vitamin D and alendronate on lumbosacral vertebral fusion in patients undergoing posterior spinal fusion surgery. Materials and methods: A single-blind clinical trial was carried out in 75 patients. Patients were divided into three groups (n=25 per group) using block randomization: Alendronate group who received 70 mg oral alendronate every two weeks, Vitamin D group to receive vitamin D 50,000 units per month for six months, and control group who received routine treatment after the surgery. After six months, the patients underwent CT scan of the lumbar region for clinical assessment of lumbar fusion. Pain intensity was assessed using Visual Analogue Scale (VAS), one and six months after the surgery. Data analysis was performed in SPSS V16. Results: Before surgery, pain intensity was higher in vitamin D group (6.36 ± 1.3) than the controls and alendronate group (P <0.0001). The last VAS in this group reached 2.12 ± 0.97 indicating decrease in pain intensity. Overall, there was a significant decrease in pain intensity in all three groups (P<0.0001). Non-fusion was found to be more frequent in control group (16%) compared to the vitamin D (12%) and alendronate (8%) groups (P=0.900). Conclusion: In current study, vitamin D and alendronate supplementation slightly improved lumbosacral fusion. Therefore, further studies are needed to investigate the effectiveness of combined treatment with alendronate and vitamin D on pain intensity and lumbosacral fusion in these patients.   (Clinical Trials Registry Number: IRCT20180826040869N2

Lessons Learned from In-Person Conferences in the Times of COVID-19

Scientific societies and conference secretariats have recently resumed in-person meetings after a long pause owing to the COVID-19 pandemic. Some safety measures continue to be implemented at these in-person events to limit the spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). With increased numbers of waves of infection, caused by the emergence of SARS-CoV-2 variants, additional information is needed to ensure maximal safety at in-person events. The MEX-DART case study was conducted at the in-person Hep-DART 2021 conference, which was held in Los Cabos, Mexico, in December 2021. Many COVID-19 safety measures were implemented, and incidence of SARS-CoV-2 infection during the conference was tested onsite. In this study, we highlight the specific conditions and safety measures set in place at the conference. In addition to vaccination requirements, social distancing, and mask wearing, daily rapid testing was implemented for the duration of the conference. At the end of the 4-day meeting, none of the 166 delegates (and family members attending the conference) had tested antigen positive for SARS-CoV-2. Two delegates tested positive in the week after the conference; the timing of their positive test result suggests that they contracted the virus during their travels home or during postconference vacationing. We believe that this model can serve as a helpful template for organizing future in-person meetings in the era of COVID-19 and any other respiratory virus pandemics of the future. While the outcomes of this case study are encouraging, seasonal surges in respiratory virus infections such as SARS-CoV-2, RSV, and influenza virus incidence suggest that continued caution is warranted

Epidemiological and biological evidence for a compensatory effect of connection domain mutation N348I on M184V in HIV-1 reverse transcriptase

BACKGROUND: The connection domain mutation N348I confers resistance to zidovudine (AZT) and is associated with the lamivudine (3TC) mutation M184V. We explored the biochemical and virological influence of N348I in the context of M184V. METHODS: Genotypic resistance data for patients receiving monotherapy or dual therapy with AZT, lamivudine (3TC), or AZT/3TC were analyzed. Rates of N348I emergence were compared between treatment groups. Mutant reverse transcriptases (RTs) containing M184V and/or N348I were generated to study enzymatic and virological properties. RESULTS: We included 50 AZT-treated, 11 3TC-treated, and 10 AZT/3TC-treated patients. N348I was observed in 3 (6%), 0, and 4 (40%) of these patients, respectively. The rate of N348I emergence was increased by 5-fold in the AZT/3TC group (11.7 instances [95% confidence interval {CI}, 3.2-30.1 instances] per 100 person-years of receipt of AZT), compared with the rate noted for the AZT group (2.3 instances [95% CI, 0.4-6.8 instances] per 100 person-years of receipt of AZT; P = .04). Biochemical data show that N348I can partially compensate for the diminution in processive DNA synthesis and the reduction in AZT excision associated with M184V. Furthermore, virological analyses demonstrate that N348I confers low-level resistance to AZT and partly restores the reduced RT activity of the M184V variant. CONCLUSION: In vivo selection of N348I is driven by AZT and is further facilitated when 3TC is coadministered. Compensatory interactions between N348I and M184V help to explain these findings

Improvement of dietary oil consumption following a community trial in a developing country: The role of translational research in health promotion

BACKGROUND: This study aimed to determine the effects of the interventions of Isfahan Healthy Heart Program (IHHP) on the type of oil consumed at the population level. It also tried to assess how this strategy has been effective as a health policy. METHODS: The IHHP, a six-year community intervention program (2001-07), aimed at health promotion through the modification of cardiovascular disease risk factors. It was performed in Isfahan and Najafabad counties (intervention area) and Arak county (reference area), all in central Iran. This study targeted the whole population of over 2,000,000 in the intervention area. The findings of annual independent sample surveys were compared with the reference area. Dietary interventions were performed as educational, environmental, and/or legislative strategies. RESULTS: From 2001 to 2007, the mean of changes for hydrogenated oil consumption was -3.2 and -3.6, and for liquid oil it was 3.6 and 2.8 times per week in the intervention and reference areas, respectively (P &lt; 0.001). According to Commerce office record, the increase in liquid oil distribution during 2000-2007 was significantly higher in Isfahan than Arak (34% vs. 25%). CONCLUSION: The effects of the simple, comprehensive, and integrated action-oriented interventions of our program could influence policy making and its results at the community level. It can be adopted by other developing countries. &nbsp; Keywords: Oil Consumption, Hydrogenated Oil, Liquid Oil, Community Trial</div