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Biomedical subjects

R U Khan

Publications and source records attributed to R U Khan.

12 recordsLinked to original sources
PubMed1997

Evaluation of two simplified methods for genotyping hepatitis C virus.

A number of different approaches have been used for genotyping hepatitis C virus (HCV). Two simplified methods were evaluated, both of which used polymerase chain reaction (PCR) to amplify products from the 5' non-coding region of HCV: non-isotopic restriction fragment length polymorphism (RFLP) analysis and type-specific PCR. Sixty-four viraemic patients suffering from chronic HCV infection were studied using these two techniques; 25/64 samples were further tested with a commercial serotyping ELISA based on synthetic NS4 antigen (Murex, U.K.). The results of the three typing methods were generally in agreement with each other. When only the predominant genotype identified by each method was analysed, the 3 methods had 100% agreement. RFLP did not detect any mixed infections and it was unsuccessful in 16/64 (25%) samples. Both type-specific PCR and serotyping ELISA detected mixed infections. However, serotyping ELISA did not give typeable results in 7/25 (28%) samples, whereas type-specific PCR gave typeable results in all 64 samples. Type-specific PCR detected more mixed infections than serotyping ELISA. Direct sequencing of four PCR products with indeterminate RFLP confirmed changes in restriction enzyme recognition sites. The sequences also confirmed the validity of the predominant genotype in cases of apparent mixed infections. It is possible that some of these cases were artefacts as a result of quasispecies.

Base Sequence↗
PubMed1997

The incidence of uniparental disomy associated with intrauterine growth retardation in a cohort of thirty-five severely affected babies.

OBJECTIVE: Our purpose was to screen for uniparental disomy 35 babies with idiopathic intrauterine growth retardation < 5th percentile. STUDY DESIGN: The placenta and the baby's blood were conventionally karyotyped. Deoxyribonucleic acid from the parents, the baby's blood, and the placenta were then screened for uniparental disomy for 12 candidate chromosomes with use of chromosome-specific polymorphic deoxyribonucleic acid markers. RESULTS: Two cases of maternal uniparental disomy for chromosome 16 were found associated with confined placental mosaicism for chromosome 16. No other uniparental disomy was found for any of the 12 chromosomes tested. Four structural chromosome abnormalities were also found in this cohort through standard karyotyping. CONCLUSION: Uniparental disomy for the chromosomes tested does not explain the etiology of the majority of cases of intrauterine growth retardation < 5th percentile. Maternal uniparental disomy for chromosome 16 accounts for 5% of this cohort. Structural chromosomal abnormalities are also much higher than expected at 11%.

Chromosome Aberrations↗
PubMed1996

Prevalence of seromarkers of HBV and HCV in health care personnel and apparently healthy blood donors.

Ninety-five health care workers and 91 controls were screened for seromarkers of both HBV (HBsAg, HBeAg, Anti-HBc) and HCV (anti-HCV) by ELISA. The control group showed a much higher frequency of seromarkers for both the viruses. HBsAg was positive in 5% of study group (health care personnel) and 14% of controls. Anti-HBc as a marker of past HBV-exposure was positive in 28% of study group as compared to 36% of controls. Overall, 33% of study group and 48% of control showed one or the other marker of HBV Anti-HCV was positive in 4% of study group and 14% of controls. This study suggests that health care workers are not particularly a high risk group as compared to rest of the population.

Adult↗
PubMed1993

Viscous airflow through a rigid tube with a compliant lining: a simple model for the air-mucus interaction in pulmonary airways.

The respiratory tract of mammals is lined with a layer of mucus, described as viscoelastic semi-solid, above a layer of watery serous fluid. The interaction of these compliant layers with pulmonary airflow plays a major role in lung clearance by two-phase gas-liquid flow and in increased flow resistance in patients with obstructive airway diseases such as cystic fibrosis, chronic bronchitis and asthma. Experiments have shown that such coupled systems of flow-compliant-layers are quite susceptible to sudden shear instabilities, leading to formation of relatively large amplitude waves at the interface. Although these waves enhance the lung clearance by mobilizing the secretions, they increase the flow resistance in airways. The objective of this paper is to understand the basic interaction mechanism between the two media better by studying airflow through a rigid pipe that is lined by a compliant layer. The mathematical model that has been developed for this purpose is capable of explaining some of the published experimental observations. Wave instability theory is applied to the coupled air-mucus system to explore the stability of the interface. The results show that the onset flow speed for the initiation of unstable surface waves, and the resulting wavelength, are both very sensitive to mucus thickness. The model predicts that the instabilities initiate in the form of propagating waves for the elastic mucus where the wave speed is about 40 percent of the flow speed. The wavelength and phase speed to air velocity ratio are shown to increase with increasing mucus thickness.(ABSTRACT TRUNCATED AT 250 WORDS)

Air↗
PubMed1984

Bisalbuminemia in nephrotic syndrome (a case report).

A rare case of bisalbuminemia in a patient with minimal lesion glomerulonephritis (MLGN) in which the course of the disease and therapeutic response to steroid were typical of minimal lesion glomerulonephritis, is presented and literature reviewed.

Child↗