23 research outputs found
Evidence for a Founder Effect among HIV-infected injection drug users (IDUs) in Pakistan.
Background: We have previously reported a HIV-1 subtype A infection in a community of injection drug users (IDUs) in Karachi, Pakistan. We now show that this infection among the IDUs may have originated from a single source. Methods: Phylogenetic analysis was performed of partial gag sequences, generated using PCR, from 26 HIV-positive IDU samples. Results: Our results showed formation of a tight monophyletic group with an intra-sequence identity of \u3c 98% indicating a founder effect . Our data indicate that the HIV-1 epidemic in this community of IDUs may have been transmitted by an HIV positive overseas contract worker who admitted to having contact with commercial sex workers during stay abroad. Conclusion: Specific measures need to implemented to control transmission of HIV infection in Pakistan through infected migrant workers
Epstein-Barr Virus EBER Transcripts Affect miRNA-Mediated Regulation of Specific Targets and Are Processed to Small RNA Species
The oncogenic Epstein-Barr virus (EBV) expresses 44 mature microRNAs and two non-coding EBER RNAs of 167 (EBER1) and 172 (EBER2) nt length. MiRNA profiling of NK/T cell lines and primary cells and Northern blotting of EBV-infected cell lines and primary tumors revealed processing of EBER1 to short 5′-derived RNAs of approximately 23, 52 and 70 nt (EBER123, EBER152, and EBER170) and of EBER2 to 3′ fragments. The biogenesis of these species is independent of Dicer, and EBER123 does not act like a miRNA OPEN ACCESS Non-Coding RNA 2015, 1 171 to target its complementary sequence. EBER1, EBER2 and EBER123 were bound by the lupus antigen (La), a nuclear and cytoplasmic protein that facilitates RNAi. Consistent with this, the EBERs affect regulation of interleukin 1alpha (IL1α) and RAC1 reporters harboring miR target sequences, targets of miR-142-3p. However, the EBERs have no effect upon another target of miR-142-3p, ADCY9, nor on TOMM22, a target of ebv-miR-BART16, indicative of selective modulation of gene expression by the EBERs
A randomized phase 2 study of trastuzumab and pertuzumab (TP) compared to cetuximab and irinotecan (CETIRI) in advanced/metastatic colorectal cancer (mCRC) with HER2 amplification: SWOG S1613
Background: HER2 (ERBB2) over-expression and amplification (HER2+) is seen in a small but distinct subset (2-3%) of mCRC and is enriched in RAS/BRAF wild type (WT) tumors. This subset is characterized by a limited response to anti-epidermal growth factor receptor monoclonal antibodybased (anti-EGFR) therapy and a promising response to dual-HER2 inhibition.
Methods: In this multicenter, open label, randomized, phase 2 trial, we enrolled 54 patients with RAS/BRAF WT HER2+ mCRC who had had disease progression after 1 or 2 previous therapies. HER2 status was confirmed centrally with immunohistochemistry (IHC) and in-situ hybridization (ISH). HER2+ was defined as IHC 3+ or 2+ and ISH amplified (dual-probe HER2/CEP17 ratio \u3e 2.0). Patients were then randomly assigned in a 1:1 ratio to receive either TP (trastuzumab [loading 8 mg/kg then 6 mg/kg] + pertuzumab [loading 840 mg then 420 mg] every 3 weeks) or CETIRI (cetuximab 500 mg/m2 + irinotecan 180 mg/m2 every 2 weeks). Crossover was allowed for patients on CETIRI arm to TP (cTP) after progression. Restaging (per RECIST v1.1) was performed at 6 and 12 weeks and then every 8 weeks until progression. The primary endpoint was progression-free survival (PFS). Key secondary endpoints were overall response rate (ORR), overall survival (OS) and safety.
Results: A total of 54 (out of planned 62 due to low accrual) patients were randomized to TP (26) and CETIRI (28) between 10/2017 and 12/2021. By 8/18/2022, 20 patients had crossed over to cTP arm. One CETIRI patient was not analyzable. The results for key endpoints by protocol defined stratification factors, prior irinotecan (Piri) (yes or no) and HER2/CEP17 ratio (HCR) (\u3e5 or ≤5), are summarized as of data cut-off of 9/6/2022. PFS did not vary significantly by treatment: medians 4.4 (95%CI: 1.9 - 7.6) months in TP group and 3.7 (95%CI: 1.6 - 6.7) months in CETIRI group (p = 0.35). Grade≥3 adverse events occurred in 23%, 46% and 40% of patients in TP, CETIRI and cTP groups.
Conclusions: Dual-HER2 inhibition with TP appears to be a safe and effective treatment option for patients with RAS/BRAF WT HER2+ mCRC with a promising response rate of31%.Higher level of HER2 amplification may provide a greater degree of clinical benefit from TP compared to CETIRI. Future correlative efforts will explore biomarkers of response/resistance with this strategy
Prevalence of HCV and HIV infections in 2005-Earthquake-affected areas of Pakistan
<p>Abstract</p> <p>Background</p> <p>On October 8, 2005, an earthquake of magnitude 7.6 hit the Northern parts of Pakistan. In the post-earthquake scenario, overcrowding, improper sewage disposal, contamination of food and drinking water, hasty surgical procedures, and unscreened blood transfusions to earthquake victims most likely promotes the spread of infections already prevalent in the area.</p> <p>Objective</p> <p>The objective of the study reported here was to determine the prevalence of Human Immunodeficiency and Hepatitis C viruses (respectively, HIV and HCV) in the earthquake-affected communities of Pakistan. The samples were analyzed 2 months and then again 11 months after the earthquake to estimate the burden of HIV and HCV in these areas, and to determine any rise in the prevalence of these viral infections as a result of the earthquake.</p> <p>Methods</p> <p>Blood samples were initially collected during December, 2005 to March 2006, from 245 inhabitants of the earthquake-affected areas. These samples were screened for HCV and HIV, using immunochromatography and Enzyme-Linked Immuno-Sorbent Assay (ELISA).</p> <p>Results</p> <p>Out of 245 samples tested, 8 (3.26%) were found positive for HCV, and 0 (0.0%) for HIV, indicating the existence of HCV infection in the earthquake-stricken areas. The same methods were used to analyze the samples collected in the second round of screening in the same area, in September, 2006 – 11 months after the earthquake. This time 290 blood samples were collected, out of which 16 (5.51%) samples were positive for HCV, and 0 for HIV.</p> <p>Conclusion</p> <p>A slightly higher prevalence of HCV was recorded 11 months after the earthquake; this increase, however, was not statistically significant. None of the study participants was found HIV-infected.</p
Physical activity, smoking, and genetic predisposition to obesity in people from Pakistan:the PROMIS study
Background: Multiple genetic variants have been reliably associated with obesity-related traits in Europeans, but little is known about their associations and interactions with lifestyle factors in South Asians. Methods: In 16,157 Pakistani adults (8232 controls; 7925 diagnosed with myocardial infarction [MI]) enrolled in the PROMIS Study, we tested whether: a) BMI-associated loci, individually or in aggregate (as a genetic risk score - GRS), are associated with BMI; b) physical activity and smoking modify the association of these loci with BMI. Analyses were adjusted for age, age(2), sex, MI (yes/no), and population substructure. Results: Of 95 SNPs studied here, 73 showed directionally consistent effects on BMI as reported in Europeans. Each additional BMI-raising allele of the GRS was associated with 0.04 (SE = 0.01) kg/m(2) higher BMI (P = 4.5 x 10(-14)). We observed nominal evidence of interactions of CLIP1 rs11583200 (P-interaction = 0.014), CADM2 rs13078960 (P-interaction = 0.037) and GALNT10 rs7715256 (P-interaction = 0.048) with physical activity, and PTBP2 rs11165643 (P-interaction = 0.045), HIP1 rs1167827 (P-interaction = 0.015), C6orf106 rs205262 (P-interaction = 0.032) and GRID1 rs7899106 (P-interaction = 0.043) with smoking on BMI. Conclusions: Most BMI-associated loci have directionally consistent effects on BMI in Pakistanis and Europeans. There were suggestive interactions of established BMI-related SNPs with smoking or physical activity
Study of PKRBD in HCV genotype 3a infected patients in response to interferon therapy in Pakistani population
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Global burden of 288 causes of death and life expectancy decomposition in 204 countries and territories and 811 subnational locations, 1990–2021: a systematic analysis for the Global Burden of Disease Study 2021
BACKGROUND Regular, detailed reporting on population health by underlying cause of death is fundamental for public health decision making. Cause-specific estimates of mortality and the subsequent effects on life expectancy worldwide are valuable metrics to gauge progress in reducing mortality rates. These estimates are particularly important following large-scale mortality spikes, such as the COVID-19 pandemic. When systematically analysed, mortality rates and life expectancy allow comparisons of the consequences of causes of death globally and over time, providing a nuanced understanding of the effect of these causes on global populations. METHODS The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2021 cause-of-death analysis estimated mortality and years of life lost (YLLs) from 288 causes of death by age-sex-location-year in 204 countries and territories and 811 subnational locations for each year from 1990 until 2021. The analysis used 56 604 data sources, including data from vital registration and verbal autopsy as well as surveys, censuses, surveillance systems, and cancer registries, among others. As with previous GBD rounds, cause-specific death rates for most causes were estimated using the Cause of Death Ensemble model-a modelling tool developed for GBD to assess the out-of-sample predictive validity of different statistical models and covariate permutations and combine those results to produce cause-specific mortality estimates-with alternative strategies adapted to model causes with insufficient data, substantial changes in reporting over the study period, or unusual epidemiology. YLLs were computed as the product of the number of deaths for each cause-age-sex-location-year and the standard life expectancy at each age. As part of the modelling process, uncertainty intervals (UIs) were generated using the 2·5th and 97·5th percentiles from a 1000-draw distribution for each metric. We decomposed life expectancy by cause of death, location, and year to show cause-specific effects on life expectancy from 1990 to 2021. We also used the coefficient of variation and the fraction of population affected by 90% of deaths to highlight concentrations of mortality. Findings are reported in counts and age-standardised rates. Methodological improvements for cause-of-death estimates in GBD 2021 include the expansion of under-5-years age group to include four new age groups, enhanced methods to account for stochastic variation of sparse data, and the inclusion of COVID-19 and other pandemic-related mortality-which includes excess mortality associated with the pandemic, excluding COVID-19, lower respiratory infections, measles, malaria, and pertussis. For this analysis, 199 new country-years of vital registration cause-of-death data, 5 country-years of surveillance data, 21 country-years of verbal autopsy data, and 94 country-years of other data types were added to those used in previous GBD rounds. FINDINGS The leading causes of age-standardised deaths globally were the same in 2019 as they were in 1990; in descending order, these were, ischaemic heart disease, stroke, chronic obstructive pulmonary disease, and lower respiratory infections. In 2021, however, COVID-19 replaced stroke as the second-leading age-standardised cause of death, with 94·0 deaths (95% UI 89·2-100·0) per 100 000 population. The COVID-19 pandemic shifted the rankings of the leading five causes, lowering stroke to the third-leading and chronic obstructive pulmonary disease to the fourth-leading position. In 2021, the highest age-standardised death rates from COVID-19 occurred in sub-Saharan Africa (271·0 deaths [250·1-290·7] per 100 000 population) and Latin America and the Caribbean (195·4 deaths [182·1-211·4] per 100 000 population). The lowest age-standardised death rates from COVID-19 were in the high-income super-region (48·1 deaths [47·4-48·8] per 100 000 population) and southeast Asia, east Asia, and Oceania (23·2 deaths [16·3-37·2] per 100 000 population). Globally, life expectancy steadily improved between 1990 and 2019 for 18 of the 22 investigated causes. Decomposition of global and regional life expectancy showed the positive effect that reductions in deaths from enteric infections, lower respiratory infections, stroke, and neonatal deaths, among others have contributed to improved survival over the study period. However, a net reduction of 1·6 years occurred in global life expectancy between 2019 and 2021, primarily due to increased death rates from COVID-19 and other pandemic-related mortality. Life expectancy was highly variable between super-regions over the study period, with southeast Asia, east Asia, and Oceania gaining 8·3 years (6·7-9·9) overall, while having the smallest reduction in life expectancy due to COVID-19 (0·4 years). The largest reduction in life expectancy due to COVID-19 occurred in Latin America and the Caribbean (3·6 years). Additionally, 53 of the 288 causes of death were highly concentrated in locations with less than 50% of the global population as of 2021, and these causes of death became progressively more concentrated since 1990, when only 44 causes showed this pattern. The concentration phenomenon is discussed heuristically with respect to enteric and lower respiratory infections, malaria, HIV/AIDS, neonatal disorders, tuberculosis, and measles. INTERPRETATION Long-standing gains in life expectancy and reductions in many of the leading causes of death have been disrupted by the COVID-19 pandemic, the adverse effects of which were spread unevenly among populations. Despite the pandemic, there has been continued progress in combatting several notable causes of death, leading to improved global life expectancy over the study period. Each of the seven GBD super-regions showed an overall improvement from 1990 and 2021, obscuring the negative effect in the years of the pandemic. Additionally, our findings regarding regional variation in causes of death driving increases in life expectancy hold clear policy utility. Analyses of shifting mortality trends reveal that several causes, once widespread globally, are now increasingly concentrated geographically. These changes in mortality concentration, alongside further investigation of changing risks, interventions, and relevant policy, present an important opportunity to deepen our understanding of mortality-reduction strategies. Examining patterns in mortality concentration might reveal areas where successful public health interventions have been implemented. Translating these successes to locations where certain causes of death remain entrenched can inform policies that work to improve life expectancy for people everywhere. FUNDING Bill & Melinda Gates Foundation
Association of the BB genotype of the ABO gene with the risk of acute myocardial infarction in hospital-based study
Objectives: The ABO gene locus has been identified to be associated with myocardial infarction in patients with coronary heart disease. The primary focus of this hospital-based study was to explore the relationship of ABO blood groups and ABO genotypes with acute myocardial infarction (AMI) in Karachi, Pakistan.Methods: In a comparative cross-sectional study, an equal number of adult AMI patients and healthy controls (n=275 in each group; age range 30-70 years, both males and females) were recruited from the Aga Khan University and NICVD, Karachi, with informed consent. The blood samples were analyzed for ABO blood groups and other biomarkers. PCR followed by RFLP techniques were employed for determining the ABO genotypes. Multinomial regression was used to evaluate the association of genotypes with the risk of AMI.Results: Thirteen different combinations of ABO genotypes were observed while the O2O2 and A2A2 genotypes were not detected. No significant association based on the distribution of blood groups A, B, O and AB among AMI patients and healthy individuals was observed. The odds of AMI were 3.32 times in subjects with BB genotype as compared to subjects with OO genotypes after adjustment of age, gender, body mass index, heart rate, total cholesterol, and waist circumference [AOR (95% CI) =3.32 (1.36-8.08), p-value =0.008].Conclusion: Our hospital-based study indicates that ABO genotype BB was significantly associated with the risk of AMI. This harmful effect of the BB genotype could have a possible relationship with AMI’s development in the Pakistani population
Highly Tunable Electrostatic Nanomechanical Resonators
There has been significant interest toward highly tunable resonators for on-demand frequency selection in modern communication systems. Here, we report highly tunable electrostatically actuated silicon-based nanomechanical resonators. Inplane doubly clamped bridges, slightly curved as shallow arches due to residual stresses are fabricated using standard electron beam lithography and surface nanomachining. The resonators are designed such that the effect of midplane stretching dominates the softening effect of the electrostatic force. This is achieved by controlling the gap-to-thickness ratio and by exploiting the initial curvature of the structure from fabrication. We demonstrate considerable increase in the resonance frequency of nanoresonators with the dc bias voltages up to 108% for 180 nm thick structures with a transduction gap of 1 ae m separating them from the driving/sensing electrodes. The experimental results are found in good agreement with those of a nonlinear analytical model based on the Euler-Bernoulli beam theory. As a potential application, we demonstrate a tunable narrow bandpass filter using two electrically coupled nanomechanical arch resonators with varied dc bias voltages
Tunable nanoelectromechanical resonator for logic computations
There has been remarkable interest in nanomechanical computing elements that can potentially lead to a new era in computation due to their re-configurability, high integration density, and high switching speed. Here we present a nanomechanical device capable of dynamically performing logic operations (NOR, NOT, XNOR, XOR, and AND). The concept is based on the active tuning of the resonance frequency of a doubly-clamped nanoelectromechanical beam resonator through electro-thermal actuation. The performance of this re-configurable logic device is examined at elevated temperatures, ranging from 25 degrees C to 85 degrees C, demonstrating its resilience for most of the logic operations. The proposed device can potentially achieve switching rate in mu s, switching energy in nJ, and an integration density up to 10(6) per cm(2). The practical realization of this re-configurable device paves the way for nano-element-based mechanical computing