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Biomedical subjects

S Subramanian

Publications and source records attributed to S Subramanian.

At least 199 records · Page 11Linked to original sources
PubMed1989

Non-organ specific & organ-specific auto-antibodies in hepatitis-B virus associated glomerulonephropathies.

Eighty eight patients of glomerulonephropathies (HBsAg positive 67; HBsAg negative 21) and 88 matched and healthy controls were screened for non-organ specific autoantibodies-ANA, AMA, ASMA and APCA by indirect immunofluorescent technique. The 2.3 per cent positivity in the test group and the 8 per cent positivity in the control group did not suggest the involvement of hepatitis-B virus (HBV), as an influencing or associated agent. When 48 patients with glomerulonephropathies and 23 controls were screened for liver cell membrane (LMA) and renal cell membrane antibodies (RMA) by indirect immunofluorescent technique using isolated rat hepatocytes and renal cells, 79.2 per cent LMA positivity was seen in the HBsAg positive group and 41.7 per cent in the negative group and RMA positivity was 58 per cent in the positive group and 25 per cent in the negative group. Simultaneous positivity for both LMA and RMA was recorded in 50 per cent of the HBsAg positive patients and 15.7 per cent of the negative ones. The results suggest the possibility of an organ specific autoimmune trigger more frequently in HBV associated glomerulonephropathy.

Antibody Specificity↗
PubMed1988

Effect of Phyllanthus amarus on chronic carriers of hepatitis B virus.

In a preliminary study, carriers of hepatitis B virus were treated with a preparation of the plant Phyllanthus amarus for 30 days. 22 of 37 (59%) treated patients had lost hepatitis B surface antigen when tested 15-20 days after the end of the treatment compared with only 1 of 23 (4%) placebo-treated controls. Some subjects have been followed for up to 9 months. In no case has the surface antigen returned. Clinical observation revealed few or no toxic effects. The encouraging results of this preliminary study recommend continued evaluation of this plant and the active principles isolated from it.

Adolescent↗
PubMed1988

Proton relaxation times in cancer diagnosis.

Proton nuclear magnetic resonance relaxation parameters (T1, T2) were measured for over 100 malignant and normal tissue samples of various organs of the human body. The purpose of this study was to estimate the reliability of the NMR technique in discriminating normal from malignant tissues. Breast and cervix samples were analyzed by using the malignancy index concept and we were able to distinguish malignant and normal tissue in 17 out of 18 breast samples and 5 out of 7 cervix samples. Since the relaxation data of a normal control population of the other organs were not available, the data for these are reported without any further analysis. The distinction between carcinomas and sarcomas was also made by using the estimated relaxation parameters. Malignancy indices of breast tissue samples for linear least-squares and nonlinear two-parameter and three-parameter least-squares procedures were calculated and used to evaluate the relative efficiencies in discriminating malignant from normal tissues.

Breast Neoplasms↗
PubMed1988

A microcomputer-based software interface for automatic acquisition of fetal monitoring data.

At University Hospital, interfaces are being designed to link-stand-alone patient care devices to Hospital Information System (HIS). The objective is to have an integrated HIS comprising of data from bedside patient monitors and from stand-alone devices such as infusion pumps, fetal monitors, and pulse oximeters. Interfaces are implemented with standard hardware and software design tools. The feasibility of designing a general purpose interface hardware based on a common microprocessor has been demonstrated for an IMED model 960 infusion pump. The present paper describes the implementation of the software component of the interface using standard microcomputer software packages. The device of choice was the Corometrics model 115 fetal monitor for implementing the software because it is used extensively at University Hospital and has built-in data communication hardware. The Corometrics model 115 fetal monitor was interfaced to an IBM Personal Computer (PC) model XT. Data acquired from the fetal monitor was used to provide data tables and graphs. The feasibility of designing and implementing a software interface capable of acquiring and processing data received from a stand-alone device (fetal monitor) was demonstrated. A description of the important aspects of the interface software design is presented in this paper. This design will eventually be part of the HIS. A brief discussion about the design modifications necessary to acquire data from multiple devices simultaneously is also included.

Fetal Monitoring↗
PubMed1987

Comparison of the clearances of serum chylomicron triglycerides enriched with eicosapentaenoic acid or oleic acid.

Rat mesenteric lymph chylomicrons containing triglycerides enriched with either [14C]oleic acid (OA) or [14C]-eicosapentaenoic acid (EPA) were prepared by ultracentrifugation of lymph samples collected for 6 hr after a single duodenal infusion of an emulsion containing either fatty acid. These chylomicrons were injected into the jugular vein of recipient rats and, at various time intervals, blood was drawn and serum was assayed for radioactivity. In separate animals, serum lipoprotein fractions were separated by ultracentrifugation, and the redistribution of labeled fatty acid among circulating lipoproteins was determined by liquid scintillation spectrometry. When the early disappearance rates (10 min) of either total serum radioactivity or specifically the chylomicron fraction were compared, there were no differences between the groups receiving OA- or EPA-enriched chylomicrons. However, disappearance rates of EPA-enriched chylomicrons were slower than those of OA-enriched chylomicrons from 25 to 90 min. The small but significant differences in the disappearance rates for the longer time periods cannot be ascertained without further studies. At 5 min after injection of either type of chylomicron, the d less than 1.006 g/ml lipoprotein fraction of serum chylomicrons and very low density lipoproteins contained almost 90% of the original radioactivity. By 240 min, when less than 2% of the radioactivity remained, this radioactivity in the d less than 1.006 g/ml fraction was 43-46%, with concomitant increases in the low and high density lipoprotein fractions and in the lipoprotein-free serum.

Animals↗
PubMed1987

Separation of chymosin and pepsin in calf rennet by dye-ligand affinity chromatography.

When calf rennet containing approximately 15% pepsin was applied to a Cibacron Blue agarose column at pH 5.5 in a low salt medium, pepsin passed through unadsorbed while chymosin was bound to the gel in the column. After washing the column, the bound chymosin was eluted with 1.7 M NaCl or 50% (v/v) aqueous ethylene glycol. The salt eluate was analyzed and found to contain greater than 97% pure chymosin. The fraction that passed through unadsorbed was found to contain greater than 96% pure pepsin. Thus a complete separation of chymosin and pepsin was effected by this technique without having to destroy either enzyme. Both enzymes are highly negatively charged at pH 5.5 but the separation does not arise from anion exchange since the gel functions as a cation exchanger. The separation appears to result from a combination of hydrophobic and electrostatic interactions of chymosin with Blue agarose. It is suggested that the enhanced affinity of chymosin to the Blue gel over pepsin may arise from topographically specified interaction between chymosin and the blue chromophore. Differential surface hydrophobicity may also play a key role, since in the presence of 0.7 M Na2SO4 the same behavior as at low ionic strength is observed.

Adsorption↗
PubMed1987

Paroxysmal nocturnal hemoglobinuria preceding malignant lymphoma.

We diagnosed lymphoma 14 months after the patient presented with paroxysmal nocturnal hemoglobinuria. To our knowledge, this is the first presentation of both conditions in a patient. One possible explanation is that both conditions could be traced to an alteration in the most primitive hemic stem cell. Such an alteration would have resulted in abnormalities of both lymphoid and nonlymphoid cell lines.

Adult↗
PubMed1986

Fate of long-term survivors of Mustard procedure (inflow repair) for simple and complex transposition of the great arteries.

Between 1967 and 1976, 106 children with transposition of the great arteries (TGA) (55 simple, 51 complex) survived the Mustard procedure. Late death occurred in 8 patients (1 simple, 7 complex TGA). Cardiac arrhythmia developed in 31 patients, 6 of whom required a permanent pacemaker. Postoperative cardiac catheterization showed mild superior vena cava obstruction in 4 patients, mild pulmonary venous obstruction in 3, and baffle leak in 4. Only 1 of these patients underwent reoperation elsewhere for a baffle leak. Two other patients had reoperation for subpulmonary stenosis and 1, for tricuspid regurgitation. The actuarial survival at 18 years is 92 +/- 2.3%, and the event-free survival is 83 +/- 3.8% (95% confidence limits). Eighty-seven patients are in New York Heart Association Functional Class I, and 3 are in Class II. The results of this study show that the long-term survival and event-free survival have been satisfactory. Late death was significantly higher in patients with complex TGA (p = .027). Postoperative arrhythmia was common, but only 6 patients required permanent pacemakers and the incidence of late complications and reoperation has been low.

Arrhythmias, Cardiac↗
PubMed1986

Identification of a factor in HeLa cells specific for an upstream transcriptional control sequence of an EIA-inducible adenovirus promoter and its relative abundance in infected and uninfected cells.

Utilizing the gel electrophoresis/DNA binding assay, a factor specific for the upstream transcriptional control sequence of the EIA-inducible adenovirus EIIA-early promoter has been detected in HeLa cell nuclear extract. Analysis of linker-scanning mutants of the promoter by DNA binding assays and methylation-interference experiments show that the factor binds to the 17-nucleotide sequence 5' TGGAGATGACGTAGTTT 3' located between positions -66 and -82 upstream from the cap site. This sequence has been shown to be essential for transcription of this promoter. The EIIA-early-promoter specific factor was found to be present at comparable levels in uninfected HeLa cells and in cells infected with either wild-type adenovirus or the EIA-deletion mutant dl312 under conditions in which the EIA proteins are induced to high levels [7 or 20 hr after infection in the presence of arabinonucleoside (cytosine arabinoside)]. Based on the quantitation in DNA binding assays, it appears that the mechanism of EIA-activated transcription of the EIIA-early promoter does not involve a net change in the amounts of this factor.

Adenovirus Early Proteins↗
PubMed1986

Suppression of the translation defect phenotype specific for a virus-associated RNA-deficient adenovirus mutant in monkey cells by simian virus 40.

Human cells infected with adenovirus type 2 (Ad2) or Ad5 require VAI RNA for efficient translation of viral mRNAs at late times after infection. The Ad5 mutant dl-sub720 synthesized neither virus-associated I (VAI) nor VAII RNAs, and infection of human cells with this mutant resulted in reduced virion polypeptide synthesis. Infection of monkey cells with this mutant also resulted in drastic reduction of polypeptide synthesis compared with wild-type (WT) adenovirus infections. Steady-state levels of hexon-specific mRNA were found to be comparable in WT- and mutant-infected monkey cells. The in vitro translation experiments showed that double-mutant- and WT-infected cells contained comparable levels of translatable hexon mRNA (and other adenovirus late mRNAs), suggesting that the severe inhibition of hexon protein synthesis in the VA mutant involves a translation block. Preinfection of monkey cells with simian virus 40 fully restored the efficient translation of this mRNA in the VA mutant infections to the level observed in WT-infected cultures. These results raise the possibility that simian virus 40 may encode or induce factors that suppress the translation block that occurs during adenovirus infections in the absence of the VA RNAs.

Adenoviruses, Human↗
PubMed1985

Fibrin glue.

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Drug Combinations↗