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Background: The dimerization efficiency of FGFR3 transmembrane domain plays a critical role in the formation of a normal skeleton through the negative regulation of bone development. Recently, gain-of-function mutations in the transmembrane domain of FGFR3 has been described associated with an aberrant negative regulation, leading to the development of achondroplasia-group disorders, including achondroplasia (ACH), hypochondroplasia (HCH) and thanatophoric dysplasia (TD). Here, we describe a non-consanguineous Pakistani family with achondroplasia to explain hereditary basis of the disease. Methods: PCR-based linkage analysis using microsatellite markers was employed to localize the disease gene. Gene specific intronic primers were used to amplify the genomic DNA from all affected as well as phenotypically healthy individuals. Amplified PCR products were then subjected to Sanger sequencing and RFLP analysis to identify a potentially pathogenic mutation. The impact of identified mutation on FGFR3 protein's structure and stability was highlighted through different bioinformatics tools. Results: Genetic screening of the family revealed a previously reported heterozygous c.1138 G > A (p.G380R) mutation in the coding exon 8 of FGFR3 gene. Identified genetic variation was confirmed in all affected individuals while healthy individuals and controls were found genotypically normal. The results were further validated by RFLP analysis as c.1138 G > A substitution generates a unique recognition site for SfcI endonuclease. Following SfcI digestion, the electrophoretic pattern of three bands/DNA fragments for each patient is indicative of heterozygous status of the disease allele. In silico studies of the mutant FGFR3 protein predicted to adversely affect the stability of FGFR3 protein. Conclusions: Mutation in the transmembrane domain may adversely affect the dimerization efficiency and overall stability of the FGFR3, leading to a constitutively active protein. As a result, an uncontrolled intracellular signaling or negative bone growth regulation leads to achondroplasia. Our findings support the fact that p.G380R is a common mutation among diverse population of the world and like other countries, can be used as a molecular diagnosis marker for achondroplasia in Pakistan. [ABSTRACT FROM AUTHOR]

Purpose: To determine the prevalence and genetic basis of tetracycline resistance in Staphylococcus aureus. Methods: One hundred and thirty (130) clinical isolates of S. aureus were collected from Khyber Teaching Hospital, Peshawar, Pakistan. Susceptibility to antibiotics (doxycycline, tetracycline and minocycline) was determined by Kirby-Bauer disc diffusion method with minimum inhibitory concentration (MIC) evaluated on Muller-Hinton agar as described by the Clinical and Laboratory Standards Institute (CLSI). The tetracyclineresistant strains (TET-R) were screened by polymerase chain reaction (PCR) for the presence of four common tetracycline resistance determinants, viz, tet(K), tet(L), tet(M) and tet(O). Results: Sixty (46.0 %) of these isolates were methicillin-resistant S. aureus (MRSA) while 70 (54.0 %) were methicillin-susceptible S. aureus (MSSA). Seventy four (56.9 %) strains were resistant to tetracycline (TET-R), 30 (23.1 %) to minocycline and 23 (17.7 %) to doxycycline. A majority of the MRSA were resistant to tetracyclines and all the MSSA were sensitive to doxycycline and minocycline. The tet(K) gene was found in 58 isolates and tet(L) in one isolate. No tet(M) and tet(O) were detected. Conclusion: This study indicates that resistance to tetracyclines is mainly by efflux pumps mediated by tet(K) in S. aureus in northwestern Pakistan. [ABSTRACT FROM AUTHOR]

Abstract: Rotaviruses are among the major causes of gastroenteritis and diarrhea among children in developed as well as the developing countries. The rapidly evolving strain prevalence and circulation have resulted in the emergence of novel strains over the period worldwide. The introduction of G12 prototype in 1987 from Philippines and subsequently re-emergence among most of the Asian countries along with USA and Europe has provoked new research horizons to address the global distribution of rotavirus serotypes. These newly emerging subtypes and their sustenance among the population have posed tremendous challenge to the development of an effectual vaccine with heterotypic protective efficacy. In Pakistan, no data is available regarding the prevalent rotavirus serotypes; therefore, this is the first study to report the prevalence of G12 strain in Pakistan in hospitalized children with diarrhea addressing a dire need of further large-scale epidemiological surveys to resolve the underlying rotavirus isolates in both the hospitalized and the community neonatal and child population before formulating the vaccine introduction policies in the country''s routine immunization program. [Copyright &y& Elsevier]

Uncontrolled exposure of active and passive smokers to trace metals causes increase in health risks. The primary objective of this study was to determine whether local and imported cigarette brands used in Pakistan, have elevated levels of metals or not. Six metals manganese (Mn), cobalt (Co), copper (Cu), cadmium (Cd), lead (Pb) and zinc (Zn) were determined in tobacco of twenty cigarette brands (local and imported) used in Pakistan by flame atomic absorption Spectrophotometry. To overcome contamination chances and for complete digestion of analytes a microwave digester was used. The analytical results showed highest concentration of Mn (84.78 μg/g dry weight), Cd (0.525 μg/g dry weight) and Zn (14.34 μg/g dry weight) metals in imported brands in relation to counterparts from the local brands. Certain elevated levels were observed for Co (3.344 μg/g dry weight), Pb (14.16 μg/g dry weight) and Cu (7.889 μg/g dry weight) metals in local brands. The inter-metal relationships in the tobacco of local and imported cigarette brands showed some integrated variation in the selected metal levels. In view of health risk associated with the above metals, there should be a strict quality control over monitoring of heavy metals during growing, processing and smoking of tobacco. Therefore, it is prudent to minimize exposure to toxic substances whenever possible because smoking and exposure to cigarette smoke is a confounder to be taken into account when carrying out epidemiological studies on human exposure to metals. [ABSTRACT FROM AUTHOR]