Shazia Rafique

The changing epidemiology pattern and frequency distribution of hepatitis C virus in Pakistan.

Information regarding the changing pattern in hepatitis C virus (HCV) genotypes/subtypes and resulting disease outcome is not well known. The specific objective of this study was to find out the frequency distribution of HCV genotypes and changing pattern of various HCV genotypes overtime in well-characterized Pakistani HCV isolates. The genotype distribution of HCV from all the four provinces of Pakistan was tracked for a period of 10 years (2000-2009) on total 20,552 consecutive anti-HCV and HCV RNA positive patients sample using type-specific genotyping assay. Of these, 16,891 (82.2%) samples were successfully genotyped. Of these 11,189 (54.4%) were males and 9363 (45.55%) were females. Of the successfully genotyped samples, 12,537 (74.2%) were with 3a, 1834 (10.9%) with 3b, 50 (0.24%) with 3c, 678 (3.3%) with 1a, 170 (0.83%) with 1b, 49 (0.24%) with 1c, 431 (2.1%) with 2a, 48 (0.23%) with 2b, 3 (0.01%) with 2c, 13 (0.06%) with 5a, 12 (0.06%) with 6a, 101 (0.49%) with 4, and 965 (4.7%) were with mixed-genotype infection. A changing pattern of HCV genotypes prevalence was observed in Pakistan overtime, with an increase in the relative proportion of genotype 3a and mixed genotypes and a decrease of genotypes 3b, 2b, 4, 5a and 2a. This changed HCV genotype pattern might have direct impact on HCV disease outcome and new therapeutic strategies may be needed.

Global expansion of chikungunya virus: mapping the 64-year history

Chikungunya virus (CHIKV) is a mosquito-transmitted alphavirus that is emerging as a global threat because of the highly debilitating nature of the associated disease and unprecedented magnitude of its spread. Chikungunya originated in Africa and has since spread across the entire globe causing large numbers of epidemics that have infected millions of people in Asia, the Indian subcontinent, Europe, the Americas, and Pacific Islands. Phylogenetic analysis has identified four different genotypes of CHIKV: Asian, West African, East/Central/South African (ECSA), and Indian Ocean Lineage (IOL). In the absence of well-designed epidemiological studies, the aim of this review article was to summarize the global epidemiology of CHIKV and to provide baseline data for future research on the treatment, prevention, and control of this life-threatening disease.

M-Polynomial and Degree-Based Topological Indices of Polyhex Nanotubes

The discovery of new nanomaterials adds new dimensions to industry, electronics, and pharmaceutical and biological therapeutics. In this article, we first find closed forms of M-polynomials of polyhex nanotubes. We also compute closed forms of various degree-based topological indices of these tubes. These indices are numerical tendencies that often depict quantitative structural activity/property/toxicity relationships and correlate certain physico-chemical properties, such as boiling point, stability, and strain energy, of respective nanomaterial. To conclude, we plot surfaces associated to M-polynomials and characterize some facts about these tubes.

M-Polynomial and Related Topological Indices of Nanostar Dendrimers

Dendrimers are highly branched organic macromolecules with successive layers of branch units surrounding a central core. The M-polynomial of nanotubes has been vastly investigated as it produces many degree-based topological indices. These indices are invariants of the topology of graphs associated with molecular structure of nanomaterials to correlate certain physicochemical properties like boiling point, stability, strain energy, etc. of chemical compounds. In this paper, we first determine M-polynomials of some nanostar dendrimers and then recover many degree-based topological indices.

Seroepidemiology of dengue fever in Khyber Pakhtunkhawa, Pakistan

BACKGROUND Dengue is the most important vector-borne disease in many different parts of the world and is expanding into other areas of the globe without hindrance. The morbidity and mortality due to dengue complications are increasing globally at an alarming rate. Although transmission of the dengue virus has been documented in well-characterized areas of Pakistan, its incidence in Khyber Pakhtunkhawa has not been characterized. To address this issue we aimed to determine the seroprevalence of dengue (IgM and IgG) antibodies and the disease symptoms in the population of Khyber Pakhtunkhawa, and to investigate the incidence of dengue fever in different seasons and in urban as well as in rural areas. METHODS From August to October 2011, data of suspected dengue patients were collected from different primary, secondary, and tertiary collection centers situated in Khyber Pakhtunkhawa in order to determine the actual seroprevalence of dengue antibodies (IgM and IgG) in Khyber Pakhtunkhawa. RESULTS A total 612 subjects with a suspected infection were enrolled in our study. Of the 612 suspected cases, 319 were found positive for dengue IgG, IgM, or both IgG and IgM. The overall weighted prevalence of dengue-specific antibodies (IgM and/or IgG) was 52.12%. Overall, of the 52.12%, 31.86% (95% confidence interval (CI) 28.17-35.55) were positive for dengue IgM and 20.26% (95% CI 17.03-23.39) were positive for dengue IgG. Only 23 (3.75%) samples showed both IgG and IgM antibodies. A higher prevalence of IgM (39.35%, 95% CI 32.84-45.86) and IgG (22.42%, 95% CI 16.86-27.98) antibodies was found in the age group 21-30 years as compared to the children age group (≤10 years) and the oldest age group (≥51 years). The mean age of the febrile cohort was 53.16 ± 44.22 years, ranging from 4 to 85 years. Age group was not statistically associated with IgM (p=0.64) or IgG (p=0.49) positivity. A higher seroprevalence of IgM (37.24%, 95%CI 32.84-45.86) was observed in males as compared to females (IgM 17.88%, 95% CI 11.11-24.65) while higher seroprevalnce of IgG (22.76%, 95% CI 15.35-30.17) was seen in females as compared to males (IgG 17.58%, 95% CI 14.21-20.95). Gender was not significantly associated with IgM (p=0.06) or IgG (p=0.53) positivity. Dengue IgM (35.38%, 95% CI 38.61-62.91) and IgG (50.76%, 95% CI 38.61-62.91) were higher in patients who had a history of travel to a dengue endemic area as compared to those who did not (IgM 33%, 95% CI 29.06-36.94, and IgG 15%, 95% CI 12.01-17.99). History of travel to an endemic area was significantly associated with IgM (p=0.023) and IgG (p=0.041) positivity. A higher incidence of IgM (41.13%, 95% CI 35.55-46.71) and IgG (27.42%, 95% CI 22.36-32.48) was observed in urban areas than in rural areas (IgM 23%, 95% CI 18.34- 27.66, and IgG 13.41%, 95% CI 9.63-17.19). IgM (p=0.0005) and IgG (p=0.0007) positivity was significantly associated with area of residence. Symptoms including fever (p=0.007), headache (p=0.001), Skin rash (0.005), joint pain (0.004) and Fatigue were significantly linked to dengue fever. IgM and IgG antibodies were more frequently seen in the post-monsoon season (68.33%) than in the monsoon period (31.68%). The death ratio in the overall weighted prevalence was 2.19%. CONCLUSION The results of the present cohort study of febrile subjects show that young people and males are more susceptible to dengue fever. Dengue infection was most prominent in the post-monsoon season, in urban areas, and in patients with a history of travel to an endemic locality. Furthermore seven deaths were found in our cohort study.

M-Polynomials and Topological Indices of Titania Nanotubes

Titania is one of the most comprehensively studied nanostructures due to their widespread applications in the production of catalytic, gas sensing, and corrosion-resistant materials. M-polynomial of nanotubes has been vastly investigated, as it produces many degree-based topological indices, which are numerical parameters capturing structural and chemical properties. These indices are used in the development of quantitative structure-activity relationships (QSARs) in which the biological activity and other properties of molecules, such as boiling point, stability, strain energy, etc., are correlated with their structure. In this report, we provide M-polynomials of single-walled titania (SW TiO2) nanotubes and recover important topological degree-based indices to theoretically judge these nanotubes. We also plot surfaces associated to single-walled titania (SW TiO2) nanotubes.

Erratum: Towards peptide vaccines against Zika virus: Immunoinformatics combined with molecular dynamics simulations to predict antigenic epitopes of Zika viral proteins

The recent outbreak of Zika virus (ZIKV) infection in Brazil has developed to a global health concern due to its likely association with birth defects (primary microcephaly) and neurological complications. Consequently, there is an urgent need to develop a vaccine to prevent or a medicine to treat the infection. In this study, immunoinformatics approach was employed to predict antigenic epitopes of Zika viral proteins to aid in development of a peptide vaccine against ZIKV. Both linear and conformational B-cell epitopes as well as cytotoxic T-lymphocyte (CTL) epitopes were predicted for ZIKV Envelope (E), NS3 and NS5 proteins. We further investigated the binding interactions of altogether 15 antigenic CTL epitopes with three class I major histocompatibility complex (MHC I) proteins after docking the peptides to the binding groove of the MHC I proteins. The stability of the resulting peptide-MHC I complexes was further studied by molecular dynamics simulations. The simulation results highlight the limits of rigid-body docking methods. Some of the antigenic epitopes predicted and analyzed in this work might present a preliminary set of peptides for future vaccine development against ZIKV.

New Insights into the Epigenetics of Hepatocellular Carcinoma

Hepatocellular Carcinoma (HCC) is one of the most predominant malignancies with high fatality rate. This deadly cancer is rising at an alarming rate because it is quite resistant to radio- and chemotherapy. Different epigenetic mechanisms such as histone modifications, DNA methylation, chromatin remodeling, and expression of noncoding RNAs drive the cell proliferation, invasion, metastasis, initiation, progression, and development of HCC. These epigenetic alterations because of potential reversibility open way towards the development of biomarkers and therapeutics. The contribution of these epigenetic changes to HCC development has not been thoroughly explored yet. Further research on HCC epigenetics is necessary to better understand novel molecular-targeted HCC treatment and prevention. This review highlights latest research progress and current updates regarding epigenetics of HCC, biomarker discovery, and future preventive and therapeutic strategies to combat the increasing risk of HCC.

M-Polynomials and topological indices of V-Phenylenic Nanotubes and Nanotori

V-Phenylenic nanotubes and nanotori are most comprehensively studied nanostructures due to widespread applications in the production of catalytic, gas-sensing and corrosion-resistant materials. Representing chemical compounds with M-polynomial is a recent idea and it produces nice formulas of degree-based topological indices which correlate chemical properties of the material under investigation. These indices are used in the development of quantitative structure-activity relationships (QSARs) in which the biological activity and other properties of molecules like boiling point, stability, strain energy etc. are correlated with their structures. In this paper, we determine general closed formulae for M-polynomials of V-Phylenic nanotubes and nanotori. We recover important topological degree-based indices. We also give different graphs of topological indices and their relations with the parameters of structures.

Change in demographic pattern of dengue virus infection: evidence from 2011 dengue outbreak in Punjab, Pakistan

Dengue viral infection is a global challenge. Due to global distribution of its vector (Aedes), interepidemic phases have condensed andmore serious cases of dengue illness are being reported, especially in South America and Asia where it has become endemic. Dengue epidemics have been reported occasionally in Pakistan, with involvement of all four serotypes. The first documented outbreak of dengue viral infection occurred in Karachi in 1994, followed by another epidemic in 2005. Most reported deaths in a major outbreak of dengue infection in 2006 in Karachi were due to Serotypes 2 and 3. There have beenmany sporadic cases of dengue viral infection in Punjab,with amajor outbreak in 2003.Many cases of dengue fever have subsequently been reported in this province. Age and gender are considered to be major factors in dengue viral infection. Many studies have reported an age