Search PubMed⌕ Search

Biomedical subjects

A Kumar

Publications and source records attributed to A Kumar.

At least 1,693 records · Page 94Linked to original sources
PubMed1988

A colorimetric method for the estimation of serum glycated proteins based on differential reduction of free and bound glucose by sodium borohydride.

A new colorimetric method based on the phenol-sulfuric acid reaction is described for the estimation of serum glycated proteins by the differential reduction of free glucose and hexose bound nonenzymatically with 2.0 and 20 mg of NaBH4 in 0.02 ml of serum, respectively, at room temperature for 15 min. The values (microgram hexose/mg protein) in control subjects (n = 60) and diabetics (n = 90) were estimated to be 5.60 +/- 0.85 and 10.8 +/- 1.6, respectively. The increase was highly significant (P less than 0.001) in diabetics. The serum glycated protein levels correlate well with fasting blood sugar values (r = 0.77, P less than 0.001, n = 25). There was also a highly significant correlation between glycated protein level and glycated albumin value in individual serum samples (r = 0.85, P less than 0.001, n = 25). Values of borohydride reducible glyco-groups bound to serum proteins also correlated well with serum glycated protein levels (r = 0.96, p less than 0.001, n = 20) determined by the thiobarbituric acid assay method. The method is found to be simple and rapid, with a coefficient of variations of +/- 3.8%.

Blood Glucose↗
PubMed1988

Results of surgical reconstruction in patients with renal failure owing to ureteropelvic junction obstruction.

During the last 6 years we managed 20 patients with renal failure owing to bilateral ureteropelvic junction obstruction (12) or ipsilateral ureteropelvic junction obstruction with contralateral renal agenesis, hypoplasia or dysplasia (8). Of the patients 11 underwent emergency dialysis for hyperkalemia, fluid overload or metabolic acidosis. Mean serum creatinine at presentation was 6.5 mg. per cent. Preliminary decompression of the obstructed kidney was done in 14 patients (20 renal units) with a serum creatinine of more than 3 mg. per cent at presentation. Reconstruction was done in all patients (31 of 36 renal units) after decompression and control of infection. Pyeloplasty was done in 24 renal units, vesicopyelostomy in 3 pelvic kidneys and calicoureteroplasty in 2 renal units with an intrarenal pelvis. Two renal units were removed. All patients showed improvement in renal function and the mean postoperative serum creatinine value was 2.05 mg. per cent. The postoperative serum creatinine value showed a significant positive correlation with the initial value as well as with the initial blood urea levels. However, the postoperative serum creatinine value showed no correlation with patient age, duration of symptoms, serum creatinine level after preliminary nephrostomy and presence or absence of urinary infection. Postoperative recovery (on the basis of postoperative serum creatinine levels) in patients who had bilateral ureteropelvic junction obstruction was not different from those with a solitary functioning kidney and ureteropelvic junction obstruction.

Acute Kidney Injury↗
PubMed1988

Inhibition of murine thymidylate synthase and human dihydrofolate reductase by 5,8-dideaza analogues of folic acid and aminopterin.

A series of 5,8-dideaza analogues of folic acid, isofolic acid, aminopterin, and isoaminopterin were evaluated for inhibition of thymidylate synthase, TS, from mouse L1210 leukemia cells with 10-propargyl-5,8-dideazafolic acid, CB3717, 4a, as the reference inhibitor. These compounds were also tested as inhibitors of human dihydrofolate reductase, DHFR, obtained from WIL2 cells. None of the analogues studied were as potent as 4a toward TS; however, 9-methyl-5,8-dideazaisoaminopterin, 6d, was only 2.5-fold less effective. Compound 4a was prepared by direct alkylation of the di-tert-butyl ester of 5,8-dideazafolic acid followed by hydrolysis of the resulting diethyl ester, which resulted from concomitant transesterification. It was found to be identical with a sample of 4a prepared by earlier methodology by using a variety of spectroscopic techniques. Its isomer, 9-propargyl-5,8-dideazaisofolic acid, 4b, which was synthesized by an analogous approach, was found to be dramatically less inhibitory toward TS than 4a. Each of the 2,4-diamino derivatives, including those possessing an allyl or propargyl group at N9, was an excellent inhibitor of DHFR, having a level of potency similar to that of methotrexate, MTX. However, many of these 5,8-dideazaaminopterin analogues were far more inhibitory toward TS than MTX.

Aminopterin↗
PubMed1988

Transcriptional activation of homologous viral long terminal repeats by the human immunodeficiency virus type 1 or the human T-cell leukemia virus type I tat proteins occurs in the absence of de novo protein synthesis.

The genomes of human retroviruses [human immunodeficiency virus type 1 (HIV-1) and human T-cell leukemia virus (HTLV-I)] encode positive trans-activator proteins, named tat. In the presence of tat, the transcriptional activity of the homologous HIV-1 or HTLV-I long terminal repeat (LTR) promoter is markedly increased. We have constructed mammalian cell lines that contain stably integrated copies of a HIV-1 or a HTLV-I LTR-chloramphenicol acetyltransferase (CAT) gene. When presynthesized HIV-1 or HTLV-I tat proteins were separately introduced into these cells in the presence of cycloheximide, we found a strong increase in the steady-state expression of the homologous viral LTR. Nuclear "run-on" assays verified that this tat-mediated enhancement, occurring in the absence of de novo cellular protein synthesis, was due to increased transcriptional initiation at the LTR promoter. We conclude that one aspect of transcriptional trans-activation of viral LTR by the HIV-1 and HTLV-I tat proteins does not require the production of new cellular proteins.

Animals↗
PubMed1988

Conformations of dehydrophenylalanine containing peptides. Nuclear Overhauser effect study of two acyclic tetrapeptides.

Two isomeric, acyclic tetrapeptides containing a Z-dehydrophenylalanine residue (delta Z-Phe) at position 2 or 3, Boc-Leu-Ala-delta Z-Phe-Leu-OMe (1) and Boc-Leu-delta Z-Phe-Ala-Leu-OMe (2), have been synthesized and their solution conformations investigated by 270 MHz 1H n.m.r. spectroscopy. In peptide 1 the Leu(4) NH group appears to be partially shielded from solvent, while in peptide 2 both Ala(3) and Leu(4) NH groups show limited solvent accessibility. Extensive difference nuclear Overhauser effect (n.O.e.) studies establish the occurrence of several diagnostic inter-residue n.O.e.s (Ci alpha H----Ni+1H and NiH----Ni+1H) between backbone protons. The simultaneous observation of "mutually exclusive" n.O.e.s suggests the presence of multiple solution conformations for both peptides. In peptide 1 the n.O.e. data are consistent with a dynamic equilibrium between an -Ala-delta Z-Phe- Type II beta-turn structure and a second species with delta Z-Phe adopting a partially extended conformation with psi values of +/- 100 degrees to +/- 150 degrees. In peptide 2 the results are compatible with an equilibrium between a highly folded consecutive beta-turn structure for the -Leu-delta Z-Phe-Ala- segment and an almost completely extended conformation.

Indicators and Reagents↗
PubMed1988

Benign periurethral mass lesions: the female prostate.

Bladder outflow obstruction in the female is usually a functional complaint, but rarely may be of organic aetiology, due to peri-urethral mass lesions. These lesions are usually midline in location and present clinical and roentgenological features comparable with those of prostate in the male. Two such patients, one of pure fibroma and another of hyperplastic glandular tissue are presented and their management is discussed.

Female↗
PubMed1988

Vesicopyelostomy in the treatment of pelvic kidneys with pelviureteric junction obstruction: long-term follow-up.

The surgical management of 6 male patients with pelvic kidneys with pelviureteric junction obstruction is discussed. Two patients presented in advanced renal failure and 1 had peritonitis and septicaemia due to rupture of the renal pelvis. Vesicopyelostomy was preferred to pyeloplasty in 5 patients because of adhesions, multiple aberrant vessels, multiple stones, malrotation and the low pelvic position, but pyeloplasty was done in 1 case. Though vesicoureteric reflux was observed during voiding cystourethrography in all patients, no deleterious effect on the kidney was seen during the 3- to 5-year follow-up period.

Adolescent↗
PubMed1988

Comparative study of cephalexin hydrochloride and cephalexin monohydrate in the treatment of skin and soft tissue infections.

In two prospective, randomized multicenter double-blind studies with a dosage of either 250 mg given four times a day (study A) or 500 mg given two times a day (study B), the comparative efficacy and safety of cephalexin hydrochloride (LY061188; Keftab) and cephalexin monohydrate (Keflex) for treatment of skin and soft tissue infections were determined. In study A, 97 patients received cephalexin hydrochloride and 101 patients received cephalexin monohydrate. In study B, 75 patients received cephalexin hydrochloride and 70 patients received cephalexin monohydrate. Diagnoses included abscesses, cellulitis, wound infections, and infected dermatitis, and were comparable in the different treatment groups. Pathogens were isolated from 82% of patients enrolled; the majority of isolates were of Staphylococcus aureus, Streptococcus pyogenes, other staphylococcal species, and a few gram-negative bacteria. In study A, 68 of 71 (95.7%) evaluable patients who received cephalexin hydrochloride responded satisfactorily; 73 of 81 (90%) patients who received cephalexin monohydrate also responded satisfactorily. In study B, 56 of 58 (96.5%) evaluable patients who received cephalexin hydrochloride responded satisfactorily; 47 of 50 (94%) patients who received cephalexin monohydrate also responded satisfactorily. An adverse clinical event leading to discontinuation of the treatment drug developed in 17 of 343 (4.95%) patients in both studies. No differences were noted between the two drugs. Skin eruptions, pruritus, and mild gastrointestinal symptoms were the common adverse effects. These data suggest that cephalexin hydrochloride, a new formulation of cephalexin, is a safe and effective antimicrobial agent for treatment of a variety of skin and subcutaneous infections in a dosage of either 250 mg four times a day or 500 mg twice a day.

Adult↗
PubMed1988

Synthesis of functional human immunodeficiency virus tat protein in baculovirus as determined by a cell-cell fusion assay.

The human immunodeficiency virus tat protein is a strong trans-activator of the expression of mRNAs originating from the viral long terminal repeat. We have expressed the first 72 amino acids (coding exon 1) of this protein in eucaryotic Spodoptera frugiperda SF9 cells by using a baculovirus vector, Autographa californica nuclear polyhedrosis virus. We show that the baculovirus vector stably produced the 72-amino-acid form of the tat protein but was unable to stably synthesize a larger 101-amino-acid full-length version of the same polypeptide. The 72-amino-acid tat protein, when introduced into mammalian fibroblasts by using a cell-cell fusion technique, functionally trans-activated the expression of the human immunodeficiency virus long terminal repeat.

Amino Acid Sequence↗
PubMed1988

Cerebellar ataxia in systemic lupus erythematosus: three case reports.

Three patients presented with cerebellar ataxia among 350 cases of systemic lupus erythematosus (SLE) seen over the last 14 years. Cerebellar signs were unilateral in one and bilateral in the other two patients. Other neurological findings were present in all three patients. One initially presented with only cerebellar ataxia; other features of SLE appeared a few years later. Lupus anticoagulant test was positive in one patient. Corticosteroids given in the early stages appeared to benefit these patients by ameliorating cerebellar dysfunction.

Adolescent↗
PubMed1988

Japanese encephalitis--an important cause of acute childhood encephalopathy in Lucknow, India.

Eighty-six randomly selected children between 6 months and 12 years of age admitted with acute unexplained encephalopathy over a one year period were examined for evidence of Japanese encephalitis. One or more indicators of the infection were present in 36 (41.8%). Viral isolation from brain tissue was possible in 2 of 12 patients and from cerebrospinal fluid in 19 out of 62 patients. Serological evidence of probable Japanese encephalitis was found in 21 out of 36 patients. Japanese encephalitis is an important cause of acute childhood encephalopathy in the Lucknow area, where it is probably endemic.

Brain↗
PubMed1988

Carcinoma of the gall bladder--can we do anything?

A retrospective review of 143 cases of carcinoma of the gall bladder is presented. The disease was more common in females in the 5th and 6th decades. Pain, anorexia, weight loss and jaundice were the common presenting symptoms, and hepatomegaly and palpable gall bladder the common signs. Laboratory and radiological investigations were merely confirmatory as the diagnosis in a majority of the cases was clinically obvious. Aspiration cytology and laparoscopic biopsy were of help in obtaining histological diagnosis. Only 47 patients were considered fit enough to undergo laparotomy. In a majority of these patients biopsy alone was possible while palliative procedures were performed in the others. The operative mortality was 18% even in this selected group of patients, due to the poor general condition and the advanced stage of the disease at the time of diagnosis. Curative resection may be possible and long term survival is expected in incidentally found carcinoma at cholecystectomy. The only hope lies in prevention by prompt treatment of patients with benign biliary disease.

Adenocarcinoma↗
PubMed1988

In vitro activity of cefixime (CL284635) and other antimicrobial agents against Haemophilus isolates from pediatric patients.

In vitro activity of cefixime, an experimental oral third-generation cephalosporin and 7 other antimicrobials (ampicillin, augmentin, trimethoprim/sulfamethaxazole, cefamandole, cefotaxime, cefuroxime, and cefaclor) were determined for 150 isolates of Haemophilus obtained from pediatric patients. All (109) non-typeable H. influenzae isolates were sensitive to cefixime and cefotaxime. All (18) isolates of H. parainfluenzae were sensitive to cefotaxime, cefuroxime, cefamandole, cefaclor, and augmentin; 17/18 isolates were sensitive to cefixime. All (23) isolates of H. influenzae-b were sensitive to cefixime, cefotaxime, cefamandole, cefuroxime, cefaclor, and augmentin. Only 10/23 were sensitive to tri/sulfa. 137 of 150 (91.3%) isolates had MBCs equivalent to their MICs for cefixime, compared to 149/150 (99.3%) isolates for cefotaxime. Approximately 95% (143/150) of isolates tested had MICs of less than or equal to 0.06 microgram/ml for cefixime. These data demonstrate that in vitro cefixime has good activity against Haemophilus isolates and it is very similar to the activity of cefotaxime.

Anti-Bacterial Agents↗