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Biomedical subjects

S S Rana

Publications and source records attributed to S S Rana.

At least 19 recordsLinked to original sources
PubMed2006

Sonoenteroclysis: a new technique for the diagnosis of small bowel diseases.

BACKGROUND: Radiologic evaluation of small bowel is usually done by barium examination, which involves considerable radiation exposure. A new sonographic method, sonoenteroclysis, is a promising technique for diagnosing small intestinal disorders. In this study the applicability, performance, and diagnostic yield of sonoenteroclysis were assessed and the results of this novel method were compared with those of barium enteroclysis. METHODS: Forty-five consecutive patients with suspected small bowel disorder were studied. All patients underwent abdominal ultrasound before and after infusion of an isotonic nonabsorbable electrolyte solution containing polyethylene glycol through a nasojejunal tube (modified Billbao Dotter tube), and images at various levels were obtained. Small bowel wall thickness, luminal narrowing, intestinal dilatation, peristalsis, and extraintestinal complications were noted. It was followed by barium enteroclysis and findings were recorded. Findings of sonoenteroclysis were compared with those of barium enteroclysis. RESULTS: Satisfactory distention of the intestinal lumen was obtained with sequential visualization of jejunoileal loops in 34.4 +/- 18.4 min. Of 45 patients, 10 showed normal small bowel on sonoenteroclysis and barium enteroclysis. These 10 patients served as controls. Sonoenteroclysis displayed normal diameters smaller than 3.0 and 2.0 cm for the jejunum and ileum, respectively. Bowel wall thickness was 1.7 to 3.0 mm and all five layers of bowel wall could be well appreciated. Valvulae conniventes were clearly visualized with a fold thickness between 1.4 and 2.0 mm. The remaining 35 patients showed abnormalities in the form of strictures, matted bowel loops, dilated loops, thickened folds, deformed ileocecal junction, mass lesions, etc., on sonoenteroclysis and barium enteroclysis. In addition, sonoenteroclysis showed thickened bowel wall with loss of stratification. Extraintestinal findings such as enlarged lymph nodes and ascites were also disclosed at the time of sonography. These were diagnosed subsequently as cases of tuberculosis (n = 23), celiac disease (n = 6), adenocarcinoma (n = 2), leiomyoma (n = 2), Immunoproliferative small intestinal disease (n = 1), and segmental enteritis (n = 1). CONCLUSIONS: The diagnostic accuracy of sonoenteroclysis for detecting small bowel lesions is comparable to that of barium enteroclysis. This new, widely available, inexpensive, and undemanding technique can be used as an initial investigation in the evaluation of patients with small bowel disorders.

Adolescent↗
PubMed2004

Immunogenicity of low-dose and conventional-dose recombinant hepatitis B vaccines in healthy adolescents in India.

INTRODUCTION: The recombinant hepatitis B vaccine, at a conventional dose of 20 microgrammes, is highly effective in a majority of the population. Recent studies have reported that a 10-microgramme dose is as effective as the conventional dose, especially in young adolescents. This study compares the effect of two different doses of recombinant hepatitis B vaccine (Enivac HB) in healthy adolescents. METHODS: Ninety-two adolescents were randomised into two equal groups to receive either 10 microgrammes (group 1) or 20 microgrammes (group 2) of vaccine using the vaccination schedule of 0, one and six months. Blood samples were collected at 30, 60, 90, 180 and 210 days to detect anti-HBs antibodies. At each interval, geometric mean titres were calculated for seroconverted subjects. RESULTS: After the initial doses of the vaccine, greater proportion of subjects receiving the higher dose seroconverted. However, at six months, all subjects who received the low dose seroconverted, as did those who received the conventional dose. Furthermore, there were significant differences in the anti-HBs geometric mean titres for seroconverters at 180 days (218.27 versus 111.43) and 210 days (345.14 versus 133.35). The difference in the overall reactogenicity for the two dose levels was not remarkable, although the higher dose produced more local symptoms. CONCLUSION: 10-microgramme recombinant vaccine can be used in routine immunisation in healthy adolescents. If quick immunisation is needed, as in high-risk groups, the conventional dose should be administered, as it results in earlier seroconversion with higher anti-HBs geometric mean titres.

Adolescent↗
PubMed2003

The prevalence of hepatitis C virus antibodies among the voluntary blood donors of New Delhi, India.

Infection with hepatitis C virus (HCV) is a major cause of transfusion-associated hepatitis, cirrhosis and hepatocellular carcinoma. The present study was conducted with an objective to evaluate the prevalence of anti-HCV antibody in New Delhi, India using a large number of healthy voluntary blood donors. A total of 15,898 healthy voluntary blood donors were subjected to anti-HCV testing (using a commercially available third generation anti-HCV ELISA kit) and 249 were found to be reactive for anti-HCV antibody, yielding an overall prevalence of 1.57%. No significant difference was found between the HCV positivity rate of male (1.57%; 238/15,152) vs. female (1.47%; 11/746) donors, family (1.58%; 213/13,521) vs. altruistic (1.51%; 36/2377) donors and first-time (1.55%; 180/11,605) vs. repeat (1.61%; 69/4293) donors. The age distribution of anti-HCV reactivity showed a maximum prevalence rate of 1.8% in the age group of 20-29 years. In addition, there was a clear trend of decreasing positivity for anti-HCV with increasing age and this trend was statistically significant. The results of the present study show that the prevalence of anti-HCV antibodies in the healthy voluntary blood donors of New Delhi, India is considerably higher than the reported seroprevalence of HCV in majority of the industrialized nations and this represents a large reservoir of infection capable of inflicting significant disease burden on the society. In addition, donors of New Delhi, India showed a trend of decreasing seroprevalence with increasing age, possibly implying a higher exposure rate to HCV in younger subjects.

Adolescent↗
PubMed2002

Serological study of hepatitis A virus infection amongst the students of a medical college in Delhi & evaluation of the need of vaccination.

BACKGROUND & OBJECTIVES: Recent seroepidemiological studies have demonstrated a decrease in the seroprevalence of hepatitis A virus (HAV) infection, thereby increasing the pool of susceptible adult population. Health care workers, especially those working in paediatric wards and nurseries, are at an increased risk of developing HAV infection. The present study was undertaken to determine the prevalence of antibody against HAV (IgG anti-HAV) among a batch of medical students of the Maulana Azad Medical College, New Delhi, so as to identify the proportion of students who would be susceptible to HAV infection and hence would benefit from a vaccination programme against HAV. METHODS: A total of 91 medical students were enrolled and divided into groups on the basis of sex. The serum samples were evaluated for the presence of immunoglobulin (IgG) against HAV (IgG anti-HAV) using a commercially available enzyme linked immunosorbent assay (ELISA) kit. RESULTS: The mean age of all the subjects was 19.9 +/- 1.5 yr and the male: female ratio was 1.2: 1. Fifty seven (62.6 +/- 5.1%) students were positive for IgG anti-HAV while 34 (37.4%) were seronegative and hence susceptible to HAV infection. No statistically significant difference was observed in the seroprevalence of HAV between males and females [64 +/- 6.7% (32/50) versus 60.9 +/- 7.6% (25/41)]. INTERPRETATION & CONCLUSION: our results indicate that more than one-third of the medical students were seronegative for IgG anti-HAV and hence at an increased risk of developing HAV infection as a result of occupational exposure. Therefore, we suggest that students in a health care set up should undergo vaccination against HAV after pre-vaccination immunity screening.

Adolescent↗
PubMed1997

Acute onset of colchicine myoneuropathy in cardiac transplant recipients: case studies of three patients.

Colchicine causes both muscle and peripheral nerve toxicity of subacute onset in patients with renal insufficiency. We report three cardiac transplant recipients, treated with colchicine for cyclosporin A (CyA)-induced gout, who developed acute weakness due to colchicine myoneuropathy. The onset of disabling weakness occurred over a 1-2 week period. All three patients had concomitant renal insufficiency and an elevated serum creatine kinase and two elevated CyA levels at the time of presentation. Electromyography revealed features of myopathy and motor axonal neuropathy in all three patients. Two underwent muscle biopsy which confirmed the presence of sarcoplasmic vacuoles characteristic of colchicine-induced myopathy. All patients rapidly improved with either colchicine dose reduction or drug discontinuation. In conclusion, cardiac transplant recipients treated with CyA and colchicine may be at increased risk of developing colchicine-induced myoneuropathy especially in the setting of concurrent renal insufficiency. In patients with post-transplantation gouty arthritis, other treatment modalities are suggested; and if colchicine is administered, the dose should be reduced, CyA levels should be monitored closely and patients should be assessed for signs of neuromuscular toxicity.

Acute Disease↗
PubMed1997

Evaluation of visual function following argon laser photocoagulation in central serous retinopathy.

The authors of previous studies on the role of photocoagulation for central serous chorioretinopathy (CSR) have based their deductions on the premise that a Snellen visual acuity of 6/6 is the end point of recovery. It is now known that patients with a visual acuity of 6/6 may have defective contrast sensitivity indicative of a visual function deficit. The present study was a prospective, controlled, and randomized evaluation of patients suffering from their first attack of CSR, in which contrast sensitivity was used to determine the effectiveness of argon laser photocoagulation as compared with more conservative treatment. Although long-term studies are necessary, the results of this study showed that while photocoagulation increases the rate of recovery for visual acuity, it is also linked with significant loss and slower recovery of contrast sensitivity.

Adult↗
PubMed1996

Closed mitral valvotomy for mitral restenosis: experience in 113 consecutive cases.

The costs of heart operations and the problems related to anticoagulation after prosthetic valve replacement are among the limitations faced by patients in nonindustrialized countries with mitral stenosis caused by chronic rheumatic heart disease. The young age at which these patients are seen also compels the surgeon to preserve the native valve. The least costly and optimal way to achieve this objective is by closed mitral valvotomy. After closed mitral valvotomy, mitral restenosis is commonly encountered. We report here our 10-year experience with operation on 113 consecutive patients with mitral restenosis. Closed transventricular revalvotomy was performed with Tubbs dilator in 105 of 113 patients. Mean age was 343 years, with a male to female ratio of 1:1.5. Most patients were in New York Heart Association functional classes III and IV (74.3% and 19.4%, respectively). Mean interval between first and second valvotomy was 9.4 years, Hospital mortality rate was 2.8%, trivial postoperative mitral regurgitation occurred in 16.1%, and moderately severe regurgitation occurred in 1.9%. Early postoperative systemic embolism occurred in 3.8% of the cases. Moderate to excellent symptomatic improvement was noted in 89.4% of the cases and poor results were seen in 10.2%. Late follow-up of 76 patients ranged from 2 to 10 years (mean 3.8 years), with 39.4% patients in New York Heart Association class I and 50% in class II. Close mitral revalvotomy is thus an economical, simple, and safe palliative procedure that carries good long-term results.

Adolescent↗
PubMed1987

Structures of the sialylated oligosaccharide chains in swine tracheal mucin glycoproteins.

The structures of the major sialylated oligosaccharide chains in swine tracheal mucin glycoprotein were established. The oligosaccharide chains were released by treatment with alkaline borohydride and isolated by gel filtration on Bio-Gel P6 columns and chromatography on DEAE-cellulose. The neutral oligosaccharide chains in this glycoprotein have been characterized in previous studies (Rana, S.S., Chandrasekaran, E.V., Kennedy, J., and Mendicino, J. (1984) J. Biol. Chem. 259, 12899-12907; Chandrasekaran, E.V., Rana, S.S., Davila, M., and Mendicino, J. (1984) J. Biol. Chem. 259, 12908-12914). The present study reports the isolation of four monosialylated chains ranging in length from 6 to 14 sugar units, two disialylated chains containing 6 and 12 sugar units, and one trisialylated chain containing 9 sugar units. The structure of the sialylated oligosaccharides was determined by permethylation analysis and sequential hydrolysis with specific exoglycosidases. The following structures (where GalNAcol is N-acetylgalactosaminitol) were assigned to these oligosaccharides.

Animals↗
PubMed1987

Changes in erythroid membrane proteins during erythropoietin-mediated terminal differentiation.

Membrane and membrane skeleton proteins were examined in erythroid progenitor cells during terminal differentiation. The employed model system of erythroid differentiation was that in which proerythroblasts from mice infected with the anemia-inducing strain of Friend virus differentiate in vitro in response to erythropoietin (EP). With this system, developmentally homogeneous populations of cells can be examined morphologically and biochemically as they progress from proerythroblasts through enucleated reticulocytes. alpha and beta spectrins, the major proteins of the erythrocyte membrane skeleton, are synthesized in the erythroblasts both before and after EP exposure. At all times large portions of the newly synthesized spectrins exist in and are turned over in the cytoplasm. The remaining newly synthesized spectrin is found in a cellular fraction containing total membranes. Pulse-chase experiments show that little of the cytoplasmic spectrins become membrane associated, but that the proportion of newly synthesized spectrin which is membrane associated increases as maturation proceeds. A membrane fraction enriched in plasma membranes has significant differences in the stoichiometry of spectrin accumulation as compared to total cellular membranes. Synthesis of band 3 protein, the anion transporter, is induced only after EP addition to the erythroblasts. All of the newly synthesized band 3 is membrane associated. A two-dimensional gel survey was conducted of newly synthesized proteins in the plasma membrane enriched fraction of the erythroblasts as differentiation proceeded. A majority of the newly synthesized proteins remain in the same proportion to each other during maturation; however, a few newly synthesized proteins greatly increase following EP induction while others decrease markedly. Of the radiolabeled proteins observed in two dimensional gels, only the spectrins, band 3 and actin become major proteins of the mature erythrocyte membrane. Examination of total proteins of the plasma membrane enriched fractions of EP-treated erythroblasts using silver staining and 32P autoradiography show that many proteins and phosphoproteins are selectively eliminated from this fraction late in the course of differentiation during the reticulocyte stage. The selective removal of many proteins at the reticulocyte stage of development combined with previous selective synthesis and accumulation of some specific proteins such as alpha and beta spectrin and band 3 in the differentiating erythroblasts lead to the final mammalian erythrocyte membrane structure.

Animals↗
PubMed1986

Lysosomal-enzyme targeting: the phosphorylation of synthetic D-mannosyl saccharides by UDP-N-acetyl-glucosamine:lysosomal-enzyme N-acetylglucosamine-phosphotransferase from rat-liver microsomes and fibroblasts.

Phosphorylation of the D-mannose residues of lysosomal enzymes is essential for the uptake and intracellular transport of these enzymes to lysosomes. The GlcNAc-P-transferase which is involved in the phosphorylation reaction seems to recognize a signal, probably a protein conformation, common to many lysosomal enzymes. To evaluate the role of the carbohydrate portion of the enzyme in these phosphorylation reactions, the acceptor specificity of GlcNAc-P-transferase from rat-liver microsomes and fibroblasts was examined with the aid of synthetic D-mannosyl disaccharides and derivatives that are closely related to the high-mannose type of oligosaccharides. Four methyl D-mannobiosides were synthesized, and their structures were established by 13C-n.m.r. spectroscopy. Of all the D-mannosyl saccharides tested, alpha-D-Man-(1----2)-alpha-D-Man-(1----OMe) was found to be the best acceptor, thereby suggesting that oligosaccharide structure may also have a role to play in recognition by this enzyme.

Animals↗
PubMed1986

Synthesis of methyl 2-O- and 3-O-alpha-D-talopyranosyl-alpha-D-mannopyranoside.

Methyl 3,4,6-tri-O-benzyl-2-O-[6-O-(tert-butyldiphenylsilyl)-alpha-D- mannopyranosyl]-alpha-D-mannopyranoside (2) was synthesized by treatment of methyl 3,4,6-tri-O-benzyl-2-O-alpha-D-mannopyranosyl-alpha-D-mannopyranoside with tert-butylchlorodiphenylsilane in the presence of imidazole. Isopropylidenation, followed by oxidation with pyridinium chlorochromate, and stereoselective reduction with sodium borohydride, converted 2 into methyl 3,4,6-tri-O-benzyl-2-O-[6-O-(tert-butyldiphenylsilyl)-2,3-O-isopro pylidene- alpha-D-talopyranosyl]-alpha-D-mannopyranoside (5). Treatment of 5 with a molar solution of tetrabutylammonium fluoride in dry oxolane produced a diol which, on O-de-isopropylidenation followed by catalytic hydrogenolysis, afforded the disaccharide glycoside methyl 2-O-alpha-D-talopyranosyl-alpha-D-mannopyranoside. Synthesis of methyl 3-O-alpha-D-talopyranosyl-alpha-D-mannopyranoside was accomplished by a similar reaction-sequence. The structures of the final disaccharides, and of various other intermediates, were established by 1H- and 13C-n.m.r. spectroscopy.

Disaccharides↗
PubMed1984

Purification and structures of oligosaccharide chains in swine trachea and Cowper's gland mucin glycoproteins.

Mucin glycoproteins were purified from extracts of swine trachea mucosa and Cowper's gland. The gelatinous extracts were solubilized by reduction and carboxymethylation and then purified by chromatography on Sepharose CL-6B and DEAE-Sepharose. The structure of some of the carbohydrate units in these glycoproteins were determined and compared. Alkaline borohydride treatment indicated that more than 85% of the carbohydrate chains in these glycoproteins were linked to serine or threonine residues in the polypeptide chain through O-glycosidic bonds with N-acetylgalactosamine. Reduced oligosaccharides released by treatment with alkaline borohydride were isolated by gel filtration on Bio-Gel P-6 and chromatography on DEAE-cellulose and paper. The structures of the oligosaccharides were established by methylation analysis, gas chromatography, and sequential hydrolysis with specific exoglycosidases. The major oligosaccharides in Cowper's gland mucin glycoproteins were sialylated short chains: NeuAc alpha 2,6GalNAcol and NeuAc alpha 2,3Gal beta 1,3(NeuAc alpha 2,6)GalNAcol. In marked contrast, branched chains containing a Gal beta 1,3(GlcNAc beta 1,6)GalNAc core unit were the major components of trachea mucin glycoprotein. Ten of these chains had the following structures: (Formula: see text).

Amino Acids↗
PubMed1984

Structures of the oligosaccharide chains in swine trachea mucin glycoproteins.

The structures of large O-glycosidically linked oligosaccharides derived from swine trachea mucin glycoprotein were established. Reduced oligosaccharides released by treatment with alkaline borohydride were separated by gel filtration on Bio-Gel P-6 and the neutral oligosaccharides were isolated by chromatography on DEAE-cellulose. Eight oligosaccharides (DIa to BII), ranging in length from 8 to 15 sugar units, were isolated. On the basis of carbohydrate composition and analytical data from sequential treatment with exoglycosidases and permethylation analysis, the following structures were assigned to these oligosaccharides: (Formula: see text).

Animals↗
PubMed1984

Synthesis of some oligosaccharides containing the O-alpha-L-fucopyranosyl-(1----2)-D-galactopyranosyl unit.

A practical approach for the synthesis of oligosaccharides containing the O-alpha-L-fucopyranosyl-(1----2)-D-galactopyranosyl unit has been developed by utilizing the readily accessible 3,4,6-tri-O-acetyl-2-O-(2,3,4-tri-O-acetyl-alpha-L- fucopyranosyl)-alpha-D-galactopyranosyl bromide (1). Thus, condensation of bromide 1 with 8-(methoxycarbonyl)octanol in benzene, in the presence of mercuric cyanide, afforded, after column-chromatographic separation, the anomers (3 and 4) of 8-(methoxycarbonyl)octyl 3,4,6-tri-O-acetyl-2-O-(2,3,4-tri-O-acetyl-alpha-L-fucopyranosyl)-D- galactopyranoside in the ratio of 13:4. On the basis of their specific rotations, compounds 3 and 4 were tentatively assigned the alpha and beta configuration, respectively. Similarly, bromide 1 was allowed to react with some other, appropriately protected sugars having a free alcohol group, to afford the corresponding alpha and beta anomers of a galactopyranosyl residue having an alpha-L-fucopyranosyl substituent at O-2. Column-chromatographic separation of the anomeric mixtures, followed by systematic removal of the protecting groups, then provided the final oligosaccharides desired. In this manner, the synthesis of the following oligosaccharides has been accomplished: alpha-L-Fuc-(1----2)-alpha-D-Gal-1----O(CH2)8CO2Me (5), alpha-L-Fuc-(1----2)-beta-D-Gal-1----O(CH2)8CO2Me (6), alpha-L-Fuc-(1----2)-alpha-D-Gal-(1----3)-beta-D-GlcNAc-1----OC6H4NO2 -p (11), alpha-L-Fuc-(1----2)-beta-D-Gal-(1----3)-beta-D-GlcNAc-1----OC6H4NO2+ ++-p (13), alpha-L-Fuc-(1----2)-alpha-D-Gal-(1----3)-alpha-D-GalNAc-1----OC6H4NO 2-o, and alpha-L-Fuc-(1----2)-beta-D-Gal-(1----3)-alpha-D-GalNAc-1----OC6H4NO2 -o (18).(ABSTRACT TRUNCATED AT 250 WORDS)

ABO Blood-Group System↗