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Biomedical subjects

R Gupta

Publications and source records attributed to R Gupta.

At least 577 records · Page 32Linked to original sources
PubMed1993

Unilateral ataxia following herpes zoster of spinal C4 segment.

Focal lesions of central nervous system are extremely rare following cutaneous herpes zoster. A 55 year old male developed cerebellar speech, right sided ataxia and intention tremor, three weeks after herpes zoster of right spinal C4 segment. Clinical examination and investigations confirmed a focal vascular lesion in the midbrain suggestive of granulomatous angiitis which can cause focal neurological defect after herpes zoster.

Cerebellar Ataxia↗
PubMed1993

DNA sequence-selective binding of head-to-tail linked bis-lexitropsins: relation of phasing to cytotoxic potency.

A series of polymethylene, -(CH2)n-tether-linked head-to-tail bislexitropsins (n = 1-7) have been synthesized in order to assess the effect on DNA binding of phasing, that arises because of lack of dimensional correspondence between oligopeptides and oligonucleotides. Binding constants to poly(dA-dT), estimated from ethidium displacement, are from 0.55 to 16.66 x 10(8) M-1. Comparable Ka values for calf thymus DNA and for poly(dG-dC) are approximately 10(6) and approximately 10(5) M-1, respectively reflecting the anticipated AT preference. Sequence-selective binding was examined by reflecting the anticipated AT preference. Sequence-selective binding was examined by methylethidium propyl ethylenediamine tetraacetic acid (MPE) complementary strand footprinting on an EcoRI/HindIII restriction fragment of pBR322 DNA with r = 0.08 and 0.32. Ligands bearing N-methylpyrrole dipeptide moieties linked by -(CH2)n, where n = 2, 4 or 6, give evidence of bidentate binding in (AT)n-rich sequences from footprinting at r = 0.32. By contrast, those ligands linked by (CH2)n, where n = 1, 3, 5 or 7, bind in a predominantly monodentate fashion. Cystostatic activity against KB human nasopharyngeal cancer cells has shown enhanced potency, compared with distamycin, for those linked bis-lexitropsins with n = 2, 4 and 6. That the increased potency may be attributed to more effective DNA binding in the latter cases is indicated by the fact that the n = 1, 3, 5 and 7 ligand homologues do not exhibit comparable enhanced cytotoxic potency.

Antineoplastic Agents↗
PubMed1993

Ascitic fluid cholesterol in differential diagnosis of ascites.

Cholesterol was estimated in ascitic fluid of 89 patients (29 malignant and 60 non-malignant ascites). Mean ascitic cholesterol level was significantly higher in malignant ascites (89.52 mg/dl) as compared to non-malignant ascites (29.93 mg/dl). At a cut off value of 48 mg/dl, the sensitivity, specificity, positive and negative predictive value and overall diagnostic accuracy for diagnosing malignant ascites is 96.5%, 96.6%, 93.3%, 98.3% and 96.6% respectively. Ascitic fluid cholesterol estimation is an easy and reliable test for differentiating malignant ascites from non-malignant ascites.

Ascites↗
PubMed1993

Prognostic significance of radiographic cardiomegaly in patients with coronary heart disease.

To define the long term prognosis in patients with coronary heart disease (CHD) we have used criteria of radiographic cardiomegaly supplemented by M-mode echocardiography. 74 patients (Group A) with CHD and cardiomegaly were seen from 1980 to 1983 and have been compared to 121 patients (Group B) with normal cardiac size and prior myocardial infarction. Patients in Group A were defined by radiographic cardiomegaly with cardio-thoracic ratio of 0.50 or more. The groups were matched for age, sex and major coronary risk factors like hypertension, total cholesterol levels, smoking and diabetes. The echocardiographic diastolic left ventricular internal dimension of 6.16 +/- 0.34 cm was significantly more in Group A as compared to 4.94 +/- 0.26 cm in Group B (t = 2.03, p < 0.05). Actuarial analysis indicates that mortality or surgical option is significantly higher in patients with cardiomegaly (Logrank test = 59.72, p < 0.001) and the mortality is significantly more during the initial years. Thus, radiographic cardiomegaly indicates a bad prognosis in patients with CHD.

Actuarial Analysis↗
PubMed1993

Induction of myocardial ischaemia by mental stress in coronary heart disease.

To define the importance of mental stress in the genesis of myocardial ischaemia in patients with coronary heart disease, we studied 50 cases in whom ischaemia was provoked by a variety of mental stress tasks: arithmetic calculations, reading aloud and emotionally arousing speech. The haemodynamic responses were compared to those induced by exercise stress tests in 38 of these patients. Thirty four of the 50 patients tested (68%) developed electrocardiographic evidence of ischaemia during mental stress tasks as compared to 29 to 38 patients (76.3%) undergoing treadmill stress test (p > 0.05). The personally relevant emotionally arousing speech task caused more frequent changes as compared to maths and reading tasks (p < 0.01), although reading task provoked more ischaemia than maths task (p < 0.01). The magnitude of ischaemic changes was similar for emotionally arousing speech and treadmill test. On comparison of haemodynamic changes in 38 patients in whom both exercise and speech tasks were performed, it was seen that ischaemic changes occurred at lower heart rates (p < 0.01), lower peak systolic blood pressure (p < 0.01) and a lower double product (p < 0.01) during emotionally arousing speech task than during treadmill stress test.

Coronary Disease↗
PubMed1993

Experience with renal transplantation in Rajasthan.

To determine th usefulness of various immunosuppressive regimens in renal transplantation and to study various complications at a new centre, we analysed 41 patients of end stage renal disease who underwent renal transplantation in our hospital over a period of three years. The first 11 patients (Group I) received azathioprine-prednisolone, the next 30 patients (Group II) received cyclosporin-prednisolone-azathioprine combination therapy. Over a mean followup of 33.36 +/- 8.19 months in group I, the survival rate was 63.6%; in group II over a followup of 14.86 +/- 2.9 months, survival was 86.66%. Kaplan-Meier survival analysis showed a trend to improved survival in group II but results did not reach statistical significance (Log rank test statistic = 2.77, p < 0.1). The incidence of infection was significantly lower in group II (p < 0.05). The major causes of death were infections, rejection, cyclosporin toxicity, acute pancreatitis, and ruptured mycotic aneurysm in one case.

Adult↗
PubMed1993

Effect of high-fat diet on mice intestinal brush border membrane composition.

Effect of feeding high-fat (26% fat) diet to mice for 21 days on intestinal brush border membrane composition was evaluated by comparing with controls fed 10% fat diet. 125I-labelled lectin binding and chemical analysis of fucose, sialic acid, hexoses and hexosamines revealed essentially similar results in control and test groups. Membrane phospholipids, expressed on dry membrane basis, were significantly reduced while total cholesterol was enhanced in experimental group compared to controls. Triglyceride content was not altered under these conditions. [14C]-acetate incorporation studies showed that decrease in phospholipid content was due to reduced synthesis of phospholipid constituents, in particular, phosphatidylcholine and phosphatidylethanolamine, as a result of feeding high fat diet. The results suggest that high amount of fat in the diet of adult mice does not alter sugar content in brush border membrane but affects membrane lipid composition.

Animals↗
PubMed1993

Immunodiagnosis of group-A streptococci by latex agglutination assays with monoclonal or monospecific polyvalent antibodies.

Seven clones of murine monoclonal antibodies specific for group-A streptococci were generated. All of them were of IgM isotypes and recognized trypsinized as well as nontrypsinized group-A streptococci and polysaccharide. These were devoid of reactivity with streptococci-B, -C, -G and Staphylococcus aureus. Polyclonal antibodies against group-A polysaccharide (APS) were also raised in rabbits by linking APS to bovine serum albumin, and rendered monospecific by adsorption. Latex agglutination assays were developed employing both types of antibodies. The assay employing monospecific polyvalent antibodies had a sensitivity of 12.5 ng APS/ml as compared to 1 microgram APS/ml for latex sensitized with monoclonal antibodies. Both assays were specific, as no agglutination was observed with polysaccharides obtained from streptococci-B, -C, -G, Staph. aureus, Cornybacterium diptheriae, Candida albicans, Candida spp., Morexella catarrhalis, Klebsiella pneumoniae, Pseudomonas aeruginosa, Escherichia coli, Streptococcus agalactiae, Strep. pneumoniae. Salmonella typhi and S. paratyphi A and B. Throat swabs from children obtained in duplicate, when tested for the presence of streptococci-A, showed a good correlation of the results obtained by latex agglutination assay with the microbial culture test and serogrouping.

Animals↗
PubMed1993

Dietary management of lactose intolerance--lactase treated milk versus soya milk.

Transient lactose intolerance secondary to infective diarrhoea is common in developing countries, & soya milk formula is commonly prescribed for its management. Lactose predigested milk feeding was done in 70 patients of test group while withdrawing lactose diet & 84.3% had control of motions with absent lactose in stool despite challenge feed, 3 days after withdrawal of lactose diet. 83.3% patients in control group fed soya milk had such improvement but the incidence of feed refusal was 30% in this group as compared to only 2.8% in lactaid group. Vomiting after feed was also found in 10% of babies fed soya milk as compared to none in lactaid group, thus proving superiority of lactaid in management of lactose intolerance diarrhoea.

Female↗
PubMed1992

Structure determination of two new amino acid-containing derivatives of adenosine from tRNA of thermophilic bacteria and archaea.

Two new nucleosides have been identified in unfractionated transfer RNA of two thermophilic bacteria, Thermodesulfobacterium commune, and Thermotoga maritima, six hyperthermophilic archaea, including Pyrobaculum islandicum, Pyrococcus furiosus and Thermococcus sp. and two mesophilic archaea, Methanococcus vannielii and Methanolobus tindarius. Structures were determined primarily by mass spectrometry, as 3-hydroxy-N-[[(9-beta-D-ribofuranosyl-9H-purin-6- yl)amino]carbonyl]norvaline, (hn6A), structure 1, and 3-hydroxy-N-[[(9-beta-D-ribofuranosyl-9H-2-methylthiopurin-6- yl)amino]carbonyl]norvaline (ms2hn6A), 2. The amino acid side chain was characterized as 3-hydroxynorvaline (3) by gas chromatography-mass spectrometry of the trimethylsilyl derivative after cleavage from 1 and 2 by alkaline hydrolysis. Evidence for the amino acid-purine carbamoyl linkage was obtained from the collision-induced dissociation mass spectrum of trimethylsilylated 1, and the total structure was confirmed by chemical synthesis of 1.

Adenosine↗
PubMed1992

Transcription, nucleosome stability, and DNA repair in a yeast minichromosome.

The template strand of the URA3 gene in the minichromosome YRpTRURAP is repaired of UV-induced cyclobutyl pyrimidine dimers (PD) much more efficiently than the nontemplate strand in growth-arrested Saccharomyces cerevisiae cells (Smerdon, M. J., and Thoma, F. (1990) Cell 61, 675). However, other regions of the plasmid are also efficiently repaired. We have examined the transcription and chromatin structure of these regions in growth-arrested cells to allow a more detailed comparison of transcription, nucleosome stability, and excision repair efficiency. Northern analysis, using strand-specific probes, indicates that four different transcripts are made from YRpTRURAP in addition to the URA3 mRNA in both growing and growth-arrested cells. The templates for these transcripts encompass all of the efficiently repaired regions outside of the URA3 gene. Nucleosome mapping indicates that the structure of the minichromosome in growth-arrested cells is indistinguishable from that of growing cells except for two nucleosomes in the region 500-800 base pairs 5' of the URA3 gene which become much less stable in growth-arrested cells. Comparison of the distribution of YRpTRURAP topoisomers in the two states, however, indicates that these nucleosomes are not lost from the majority of plasmid molecules. One of the four transcripts initiates in this region and increases by more than 5-fold in growth-arrested cells. Another transcript extends into a "slowly repaired" region which contains a very stable nucleosome. By determining the stability and relative amounts (at equilibrium) of the RNAs made from YRpTRURAP, transcription rates were determined and compared with the average PD repair rate for the different template regions. The results indicate that: 1) the rate of excision repair increases once a low, basal rate of transcription is achieved; 2) beyond this rate of transcription there is no simple correlation between the rates of transcription and PD repair; 3) nucleosome stability may "override" the coupling between transcription and repair if the transcription rate is low; and 4) at higher transcription rates, repair may be insensitive to nucleosome stability.

Base Sequence↗
PubMed1992

The structure of tracheobronchial mucins from cystic fibrosis and control patients.

Tracheobronchial mucin samples from control and cystic fibrosis patients were purified by gel filtration chromatography on Sephacryl S-1000 and by density gradient centrifugation. Normal secretions contained high molecular weight (approximately 10(7] mucins, whereas the cystic fibrosis secretions contained relatively small amounts of high molecular weight mucin together with larger quantities of lower molecular weight mucin fragments. These probably represent products of protease digestion. Reducing the disulfide bonds in either the control or cystic fibrosis high molecular weight mucin fractions released subunits of approximately 2000 kDa. Treating these subunits with trypsin released glycopeptides of 300 kDa. Trypsin treatment of unreduced mucin also released fragments of 2000 kDa that could be converted into 300-kDa glycopeptides upon disulfide bond reduction. Thus, protease-susceptible linkages within these mucins must be cross-linked by disulfide bonds so that the full effects of proteolytic degradation of mucins remain cryptic until disulfide bonds are reduced. Since various combinations of protease treatment and disulfide bond reduction release either 2000- or 300-kDa fragments, these fragments must represent important elements of mucin structure. The high molecular weight fractions of cystic fibrosis mucins appear to be indistinguishable from control mucins. Their amino acid compositions are the same, and various combinations of disulfide bond reduction and protease treatment release products of identical size and amino acid composition. Sulfate and carbohydrate compositions did vary considerably from sample to sample, but the limited number of samples tested did not demonstrate a cystic fibrosis-specific pattern. Thus, tracheobronchial mucins from cystic fibrosis and control patients are very similar, and both share the same generalized structure previously determined for salivary, cervical, and intestinal mucins.

Amino Acids↗