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Biomedical subjects

B K Das

Publications and source records attributed to B K Das.

At least 109 records · Page 6Linked to original sources
PubMed1994

Clinical evaluation of Tc-99m cystine. A new renal radiopharmaceutical.

Tc-99m cystine has been proved to be a good renal agent in animals. Its clinical evaluation has not been reported. In this study, Tc-99m cystine is used for evaluation of renal function in normal subjects and patients with chronic renal failure as well as in renal transplant patients. The results are compared with similar studies using Tc-99m DTPA and Tc-99m GHA. The clearance values also are compared with I-131 OIH. The results show that Tc-99m cystine has good radiopharmaceutical characteristics suitable for evaluation of both renal function as well as morphology.

Cystine↗
PubMed1994

Clinical evaluation of Tc-99m cystine. A new renal radiopharmaceutical.

Tc-99m cystine has been proven to be a good renal agent in animals, but its clinical evaluation has not been reported. In this study, Tc-99m cystine was used for evaluation of renal function in normal subjects and patients with chronic renal failure as well as in renal transplant patients. The results are compared with similar studies that used Tc-99m DTPA and Tc-99m GHA. The clearance values also have been compared with I-131 OIH clearance. The results show that Tc-99m cystine has good radiopharmaceutical characteristics suitable for evaluation of both renal function as well as morphology.

Cystine↗
PubMed1994

High prevalence of rotavirus infection among neonates born at hospitals in Delhi, India: predisposition of newborns for infection with unusual rotavirus.

Although rotavirus is the most common cause of diarrhea in children older than 3 months of age, neonatal infections, which are asymptomatic, have rarely been surveyed and have been identified in only a few discrete nosocomial outbreaks. After such a nosocomial outbreak of rotavirus infection among newborns at a hospital in Delhi, we screened infants born at five other nurseries in the immediate area to assess the prevalence of neonatal infections and to determine whether the unique neonatal rotavirus strain, 116E, previously identified in Delhi, was present in other settings. Infection was documented in 43 to 78% of hospitalized infants between 4 and 6 days of life born at five of the six hospitals. Infection with strains related to 116E were the most common, but other unusual strains and no strains common in the community were detected. In addition a shift in genotype was observed among specimens collected from two of these hospitals during a 2-year period. Our observation that neonatal rotavirus infections are more common than recognized previously would encourage the administration of rotavirus vaccines during the newborn period and suggests that the low efficacy of vaccines observed during trials in developing countries may be caused by early natural exposure of infants before immunization. The extraordinary predisposition of neonates for unusual rotavirus strains not commonly found in the community should encourage others to screen neonates for this infection, characterize the strains more fully and attempt to understand at a molecular level the unique relationship between the infecting strain type and the age of the host.

Feces↗
PubMed1994

Gastric emptying in patients with gallstone disease with or without dyspepsia: effect of cholecystectomy.

Dyspepsia is a common complaint in patients presenting with gallstone disease. Since the stomach appears to be its site of origin, the present study was undertaken to assess gastric emptying in patients with gallstone disease and to find out its correlation with dyspeptic symptoms before and after cholecystectomy. Gastric emptying (t1/2) was prospectively assessed in 43 patients with symptomatic gallstones (29 with and 14 without dyspepsia). These data were compared with that of 20 healthy volunteers (control group). Delayed gastric emptying (> 112 min: mean + 2 s.d. of the control group) was observed in 18 patients (42%; P < 0.002), 10 of whom presented with dyspepsia and eight without (NS). Re-evaluation in 18 of the 29 patients with dyspepsia, 3 months after cholecystectomy, revealed complete disappearance of symptoms in three, improvement in 11 and no change in four patients. After 6 months, two patients had reverted back to their pre-operative dyspeptic status; resulting in three patients completely cured, nine partially cured and six without any change in their dyspeptic status at this time. Gastric emptying was delayed in nine of the 18 patients before cholecystectomy. After cholecystectomy, normal emptying was observed in all but one patient (P < 0.005). Dyspeptic symptoms, however, completely disappeared in one patient, improved in five and remained unchanged in three. In the remaining nine patients, gastric emptying was normal both before and after cholecystectomy. Gallstone disease is associated with delayed gastric emptying but this delay was not the cause of dyspepsia in these patients. Cholecystectomy normalizes gastric emptying, a finding that has not been reported previously.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

Characterization of rotavirus strains from newborns in New Delhi, India.

Between 1986 and 1993, 72% of rotavirus strains isolated from newborns at five hospitals in New Delhi, India, had long electropherotypes, subgroup II VP6 antigens, and G and P genotypes (G9P11) identical to those of prototype strain 116E. A novel strain with a G9P6 genotype, representing 13% of the isolates, was identified. These results demonstrate that G9P11 and G9P6 rotavirus strains are common in nurseries in New Delhi.

Base Sequence↗
PubMed1994

99m Tc DTPA scan as a diagnostic marker of acute rejection in renal transplantation.

Forty renal transplant recipients were subjected to 99m Technicium Diethylene triamine pentacetic acid (DTPA)scans at regular intervals & whenever there was suspection of rejection. Serial scans of a group of 15 recipients from immediate post transplant period till withdrawal of cyclosporine were analysed separately & the results compared to with single scan analysis. The sensitivity & specificity of DTPA scan in the absence of acute tubular necrosis (ATN) was 94.1% & 87.5%, while the positive & negative predictive values were 88.8 & 93.3% respectively. Sensitivity & specificity of serial scan analysis (88.8% and 75%) in early post transplant period was higher than that of interpretation of single scan (75% & 66%). Serial scan changes predated clinical rejection during cyclosporine withdrawal period. We conclude that DTPA scan is both a sensitive & specific non-invasive diagnostic marker of acute rejection in absence of ATN & serial scans during early post transplant period & at the time of cyclosporine withdrawal are helpful in detecting the rejection accurately & at the earliest.

Adult↗
PubMed1994

Male gonadal function in Hodgkin's disease before and after treatment.

Twenty eight histologically confirmed cases of Hodgkin's disease were evaluates with regard to libido, sperm count, FSH, LH and urinary ketosteroid levels, before and during different stages of chemotherapy along with testicular biopsy on 16 cases. Decrease in libido during therapy improved following treatment, 50% cases who were oligospermic before treatment became azospermic, Serum FSH levels increased significantly (p 0.001) during the course of treatment. There was no significant change in LH and urinary ketosteroid levels (p 0.05). Testicular biopsy, normal initially, showed germ cell aplasia and absence of spermatogenesis after therapy. Drug induced testicular change leads to sterility.

17-Ketosteroids↗
PubMed1993

Similarity of the VP4 protein of human rotavirus strain 116E to that of the bovine B223 strain.

Rotavirus strain 116E was isolated from the fecal specimen of a newborn infant from New Delhi who had no symptoms of diarrhea. The strain could not be P typed using the PCR method recently developed in our laboratory so we have sequenced the 4th gene segment that encodes the VP4 protein using viral transcript RNA prepared in vitro. This gene is 2353 base pairs in length and codes for a protein 772 amino acids long which begins with a methionine initiation codon at nucleotides 11 to 13 and ends with a single termination codon at nucleotides 2327 to 2329. Northern blot analysis demonstrates that the VP4 protein of this strain is encoded by genome segment 4. This gene is closely related to the VP4 gene of the bovine B223 strain (P type 11) at both the nucleotide (90.8% identity) and amino acid (92.2% identity) levels, but is unique from those of strains from P types 1 to 10. The close relatedness of the VP4 proteins of strains 116E and B223 is demonstrated by the amino acid composition of the potential trypsin cleavage sites and their flanking sequences, the size of the cleavage fragments, and conservation of most cysteine and proline residues. Comparative amino acid analyses of the variable regions thought to be important in VP4 antigenicity are consistent with the hypothesis that strain 116E may represent the first reported human P type 11 strain.

Amino Acid Sequence↗
PubMed1993

Characterization of the G serotype and genogroup of New Delhi newborn rotavirus strain 116E.

We recently reported that the culture-adapted neonatal rotavirus strain 116E represented the first P type 11 human rotavirus, based on the close relationship of its VP4 protein to that of the bovine serotype G10P11 strain B223. In this study, we demonstrated by sequence analysis and cross-neutralization studies that the VP7 protein of 116E is closely related to those of the human serotype G9 strains, F45 and WI61, but distinct from B223 and other rotaviruses. Low-level cross-neutralization was also observed between strains 116E and B223, probably because of the antigenic similarity of their VP4 proteins. We have demonstrated by RNA-RNA hybridization that strain 116E is a reassortant between strains from the Wa and bovine (KK3-like) genogroups, deriving at least seven genes from the former and at least one gene from the latter. Together with the recent identification of serotype G10P11 newborn rotavirus strains in Bangalore, India (M. Das et al., Virology, 194, 374-379, 1993), these results are consistent with the hypothesis that reassortment may be an important mechanism for generation of rotavirus strains of newborns.

Amino Acid Sequence↗
PubMed1993

Protection conferred by neonatal rotavirus infection against subsequent rotavirus diarrhea.

A cohort of newborns in New Delhi who were nosocomially infected with rotavirus during their first days of life were followed twice weekly for 14-23 months to determine whether neonatal infection protected them against subsequent episodes of rotavirus diarrhea. Infection occurred in 60% by the fourth day of life, was asymptomatic, and was caused predominantly by an unusual rotavirus strain (G9 P11) not previously identified in humans. The 148 children with neonatal rotavirus infection had 46% fewer attacks of rotavirus diarrhea in the follow-up period than the 56 infants without nosocomial infection (0.23 vs. 0.42 episodes/child-year, P < .05). This protection was concentrated among infants in their first year of life and was not associated with a significant decrease in disease severity. Consideration of this strain as a vaccine candidate will require further assessment of its natural protection under field conditions.

Cohort Studies↗
PubMed1993

Skeletal scintigraphic findings in endemic skeletal fluorosis.

Endemic skeletal fluorosis is characterized by bone, joint and muscle pain, progressive ankylosis of various joints and crippling deformities. Whole body skeletal scintigraphy with 99Tcm-methylene diphosphonate was performed for 17 symptomatic subjects suffering from this disorder. The fluoride content of drinking water ranged from 4.1 to 12.9 mg l-1 (normal < 1 mg l-1). Urinary and serum fluoride levels were markedly elevated. Serum calcium (total and ionized), inorganic phosphorus, creatinine and albumin were essentially normal while serum alkaline phosphatase was elevated in six subjects (mean +/- S.D. 206 +/- 106; range 22-1072 IU l-1). Skeletal radiology revealed a wide spectrum of bony abnormalities. Skeletal scintigraphy revealed a picture similar to metabolic 'superscan' in all subjects, i.e. increased tracer uptake in axial and appendicular skeleton, reduced soft tissue uptake, poor or absent renal images, prominent costochondral junction and 'tie' sign in sternum. Increased uptake was present in all subjects irrespective of age, water fluoride content, serum alkaline phosphatase level and radiological abnormalities. Our findings suggest the presence of a high bone turnover state in endemic skeletal fluorosis irrespective of other variables.

Adolescent↗
PubMed1993

Evaluation of the fluorescence actin staining test for detection of enteropathogenic Escherichia coli.

Enteropathogenic Escherichia coli (EPEC) strains designated on the basis of their serotypes are epidemiologically associated with diarrhea. They adhere to the intestinal mucosa, producing the characteristic attaching and effacing (AE) lesion in an in vitro organ culture system. EPEC manifest localized adherence (LA) in the HEp-2 cell assay, and this is commonly used for clinical diagnosis. Recently, the fluorescence actin staining (FAS) test was proposed for the identification of E. coli causing the AE lesion. We therefore compared the FAS test with the HEp-2 cell assay and the EPEC adherence factor (EAF) probe assay for the detection of EPEC strains. Among 240 stool samples from children with diarrhea examined, 176 yielded E. coli and 14 of these strains showed the LA pattern in the HEp-2 cell assay; 11 of these were positive by both the EAF and the FAS tests. By using the HEp-2 cell assay as the "gold standard," the FAS test gave a sensitivity of 78.5% and a specificity of 100%. The three localized adherent FAS-negative strains tested subsequently were positive by the enteroaggregative E. coli DNA Probe and failed to produce the AE lesions characteristic of EPEC. When these strains were not considered, the sensitivity of the FAS test for detecting isolates that manifest LA was 100%. Against the EAF probe, the sensitivity and specificity of the FAS test were 91.6 and 100%, respectively. The FAS test avoids infrequent but nevertheless important phenotypic misclassifications in the HEp-2 cell assay, and it may therefore serve as a confirmatory test for EPEC.

Actins↗
PubMed1993

Comparative outcome of low birth weight babies.

One hundred and fifty six babies with birth weight between 1500-2000 g and 103 full term-appropriate for gestational age (FT-AGA) babies delivered at University Hospital, District Hospital and village homes were included for a comparative study of mortality, morbidity and growth pattern. The low birth weight (LBW) babies from the three centres had similar birth weight and gestational age. Neonatal mortality rates for the LBW babies were similar at the three centres. The main cause of death were infections and aspiration with rates again being similar. Diarrhea and respiratory tract infections were common causes of morbidity. The mortality rates for the LBW babies were significantly higher as compared to FT-AGA babies irrespective of the place of delivery. The incidence of morbidities like diarrhea and respiratory infections were also higher in LBW babies. However, the differences were statistically significant mostly in the preterm group. The weight gain of all LBW babies was similar up to 3 months of age. The findings of an identical outcome for the LBW babies at village level to those managed at hospitals is an encouraging trend to increasing domiciliary care for LBW babies.

Fetal Growth Retardation↗
PubMed1992

Identification of group A rotavirus gene 4 types by polymerase chain reaction.

Five genetically distinct human rotavirus (HRV) gene 4 groups have been described on the basis of comparative nucleotide sequencing and the predicted amino acid sequences, and at least four of them represent distinct VP4 antigenic types. To identify each gene 4 type and investigate its distribution in HRV isolates from patients with diarrhea, we developed a polymerase chain reaction (PCR) typing method using sequence information available for four genetically distinct gene 4 types. Rotavirus double-stranded RNAs (dsRNAs) isolated from stool samples were first reverse transcribed and amplified by PCR by using two oligonucleotide primers that correspond to regions that are highly conserved among all known HRV gene 4 types. The 876-bp dsDNA products were then reamplified by PCR in the presence of a cocktail containing one conserved plus-sense primer and four type-specific minus-sense primers (selected from the hypervariable region of gene 4), resulting in products of 345, 483, 267, and 391 bp corresponding to gene 4 types 1, 2, 3, and 4, respectively. This method reliably identified the gene 4 types of 16 well-characterized HRV isolates. Our results were independently confirmed for all 16 strains by reverse transcription and PCR amplification of HRV dsRNA in the presence of alternate type-specific primer pairs. For direct gene 4 typing of HRV in stool samples, we developed a method to extract rotavirus dsRNA from stool specimens by using glass powder. Our results suggest that gene 4 typing will be useful in providing more a complete characterization of HRV strains of epidemiologic or vaccine-related interest.

Base Sequence↗