Search PubMed⌕ Search

Biomedical subjects

S Roy

Publications and source records attributed to S Roy.

At least 667 records · Page 37Linked to original sources
PubMed1987

Intracerebellar schwannoma. Case report.

A rare case of a solitary schwannoma arising within the cerebellum is reported. The diagnosis was confirmed by electron microscopy and immunohistochemical staining.

Adult↗
PubMed1987

Cryptogenic fibrosing alveolitis in children.

Cryptogenic fibrosing alveolitis (CFA) in children is supposedly a rare diffuse lung disease characterized clinically by tachypnoea, cough, poor weight gain, and cyanosis. Histologically, it is characterized by thickening of alveolar walls and infiltration of the alveolar septae with mononuclear cells and fibrous tissue. The condition is more acute in children, with fulminant course. Ten children were diagnosed as having CFA out of three hundred children seen over a period of 3 years. Diagnosis was established by characteristic clinical findings and laboratory evaluation. All the children had tachypnoea at rest and bilateral crepitations in the absence of fever. Diffuse bilateral persistent irregular shadows were noted on the chest X-ray of these children. Pulmonary function studies revealed a restrictive type of abnormality with low transfer factor for carbon monoxide in six children. Open lung biopsy was done in eight children. The biopsy material was graded according to nine morphologic variables. Administration of steroids early in the course of illness resulted in amelioration of symptoms in 60% of the patients.

Adolescent↗
PubMed1987

Suprapubic versus transurethral bladder drainage after surgery for stress urinary incontinence.

Fifty-one patients with clinical and urodynamic diagnoses of stress urinary incontinence were randomly allocated to either suprapubic (N = 24) or transurethral (N = 27) bladder drainage after vaginal surgery for stress incontinence (revised Pereyra procedure). Postoperative use of suprapubic bladder drainage significantly reduced febrile morbidity (calculated as fever index; P less than .01) and length of hospitalization (P less than .05). Postoperative normal bladder functions resumed more quickly when suprapubic drainage was used (P less than .05), so that most patients did not need bladder catheterization upon discharge, as opposed to more than half of those with Foley catheters, who left the hospital with a catheter in place (P less than .05). We conclude that it is both beneficial and cost-effective to use suprapubic bladder drainage after a Pereyra operation for stress urinary incontinence.

Adult↗
PubMed1986

Mechanism of oligonucleotide loop formation in solution.

We have studied the tridecadeoxynucleotide CGCGAATTACGCG (I), which contains an additional A at position 9 compared to the dodecanucleotide of which the crystal structure has been determined. Sequence I exhibits no distinct melting curve and also has a concentration-dependent pattern of peaks on reverse-phase chromatography. This behavior is explained by a slow equilibration between loop and duplex forms in solution. We have characterized this equilibrium by proton NMR spectroscopy and shown that it is fully reversible by monitoring the two thymine methyl resonances, each of which occurs in two environments. Lower temperature and higher concentration favor the duplex; the midpoint of the transition is such that the loop predominates at room temperature. We have measured the van't Hoff enthalpy of formation of the duplex and the activation energy by temperature-jump and saturation-transfer experiments. The results are compared with those for the 17-mer sequence CGCGCGAATTACGCGCG (II), which contains two additional base pairs in the stem of the loop. The thermodynamic parameters and the effect of increasing salt concentration on the rate of conversion of the loop and duplex forms lead us to presume that the mechanism of interconversion involves complete strand separation and re-formation rather than cruciform formation and branch migration.

Base Sequence↗
PubMed1986

Mu-opioid receptor is associated with phosphatase activity.

A preparation of purified mu opioid receptor from bovine brain hydrolyzes p-nitrophenylphosphate. This phosphatase activity has a pH optimum of 9.0, a Km of 9.0 microM, and is stimulated by Mn++ and Mg++ ions. Evidence that the observed activity is not due to a contaminant in the opioid receptor preparation includes 1) the activity is associated primarily with 60,000 molecular weight material which is much smaller than bovine brain alkaline phosphatase; and 2) the activity could not be absorbed by antibodies specific for bovine alkaline phosphatase. Thus this appears to be the first demonstration of enzymatic activity associated with an opioid receptor.

4-Nitrophenylphosphatase↗
PubMed1986

ABA-specific responses are I region restricted by the carriers used for immunization.

Immunization of mice with ABA coupled to carriers to which they are nonresponders gives rise to ABA-specific proliferative responses in lymph node cells. When C3H/HeN and CBA/J nonresponder mice are immunized with ABA on (T,G)-A-L (an I-A-restricted carrier in responder mice), the responses to ABA-tyr and ABA coupled to a variety of unrelated carriers are solely I-A restricted as determined by inhibition with anti-IA and anti-I-E sera. When ABA on GLT (an I-E-restricted carrier in responder mice) is used for immunization, the responses are both I-A and I-E restricted. Thus, ABA-specific responses in nonresponder mice appear in part to be restricted by the carrier used for immunization. B10.S mice, lacking functional I-E molecules, channel their ABA-specific responses entirely through I-A when immunized with ABA-GLT. These results support the hypothesis that the failure in nonresponders lies in a functional deficit in the T cell repertoire rather than an inability of accessory cells to present antigen.

Animals↗
PubMed1986

Functioning oncocytic adenoma of the pituitary.

A case of a functioning invasive pituitary oncocytoma in a 50-year-old man is reported. The serum prolactin was increased and immunocytochemical staining was positive for prolactin. In addition to numerous mitochondria within the neoplastic cells, structurally abnormal mitochondria with crystalline inclusions were also present. Another interesting feature was the presence of about 10 to 15% of non-oncocytic cells which showed prominent RER and Golgi apparatus as found in functioning pituitary adenomas. It is likely that these secretorily active cells were responsible for the functional activity of the tumour.

Adenoma↗
PubMed1986

Treatment of chronic knee effusions with 90yttrium-correlation of in vitro radiation and chemical effects with clinical results at three and six months.

Twenty seven knees, mainly of rheumatoid patients, received intra-articular 90Y for chronic effusions; 24% were effusion-free at 6 months. In vitro chemical, radiation (32P-induced), and combined effects of cold (non-radioactive) yttrium and 32P on synovial fluid mononuclear cells, failed to show any significant correlation with subjective and/or objective clinical effects at 3 or 6 months. If 90Y exerts its therapeutic effect via these cells, it probably does so other than by a direct effect on mononuclear cell viability.

Chronic Disease↗
PubMed1986

Biochemical and histologic effects of sequential estrogen/progestin therapy on the endometrium of postmenopausal women.

Medroxyprogesterone acetate in doses of 10, 5, and 2.5 mg was administered sequentially to three groups of postmenopausal women receiving 0.3 mg, 0.625 mg, and 1.25 mg of conjugated equine estrogens, respectively. Serial endometrial biopsies were performed on these women before therapy, during estrogen therapy alone, and during sequential estrogen-progestin therapy. Endometrial histology and estrogen receptor concentrations were assessed. A linear increase of cytosolic estrogen receptor concentration occurred over the dosage range of conjugated equine estrogen. When medroxyprogesterone acetate was added to the estrogen therapy, the concentrations of estrogen receptors fell. Within the groups of women receiving 0.3 mg and 0.625 mg of conjugated equine estrogen, all doses of medroxyprogesterone acetate were equally effective in reducing the levels of cytosolic receptor to pretreatment levels. However, at the conjugated equine estrogen dose of 1.25 mg, only 5 mg and 10 mg doses were effective in reducing the cytosolic receptor concentration to pretreatment levels. Histologically, little effect was observed from the lowest doses of either drug. However, even though 5 and 10 mg of medroxyprogesterone acetate were identical biochemically, the 10 mg dose was the only one producing a homogeneous, secretory pattern within the endometrium.

Biopsy↗
PubMed1986

Urolithiasis in childhood acute leukemia and nonHodgkin's lymphoma.

Ureteral calculi were found in 5 children who were receiving or had recently completed remission induction therapy for acute leukemia or lymphoma. All 5 patients had abdominal or back pain and 3 had gross hematuria. The diagnosis of urolithiasis was suggested by excretory urograms that showed obstructive uropathy (4 patients) and by computerized tomography scans that demonstrated ureterovesical obstruction (1 patient with acute renal failure and anuria). With a single exception the calculi were not associated with urinary tract infections. Chemical analyses in the 2 patients tested indicated that the stones were composed of calcium, in contrast to the uric acid and xanthine compositions of stones in earlier studies of patients with leukemia or lymphoma. Factors that might have predisposed our patients to calculi formation include corticosteroid therapy, immobilization owing to bed rest and urinary alkalization. Other possible contributing factors were urinary stasis (2 patients) and a familial tendency for renal calculi to develop. There was no evidence of idiopathic hypercalciuria in either patient tested. Prompt detection of urolithiasis in children undergoing induction chemotherapy for a malignant disease may avoid potentially serious consequences from urinary tract obstruction.

Adolescent↗
PubMed1986

Spontaneous deletions of drug-resistance determinants from Salmonella typhimurium in Escherichia coli.

Plasmids isolated from two different clinical isolates of Salmonella typhimurium, both resistant to the antibiotics ampicillin, tetracycline, streptomycin and chloramphenicol, were used to transform Escherichia coli. Segregation of antibiotic-resistance determinants occurred in both cases. Analysis of plasmids from one set of segregants by DNA-DNA hybridisation indicated that the segregation was due to precise deletions in the transforming plasmid.

Ampicillin↗
PubMed1986

Extremely fast hydrogen exchange of ribonuclease-(1-118) as compared with native RNase A and its implication for the conformational energy state.

RNase-(1-118) containing native disulfide bonds is similar in fold to native RNase A but not of lowest Gibbs energy as compared with the isomers containing non-native disulfide bonds. The present n.m.r. studies have indicated a dramatic increase in the exchange rate of all of the 'protected' amide protons of RNase-(1-118) over RNase A. A calculation shows a large increase in the rate of 'opening' of the structure. The exchange rate of the protected amide protons of RNase-(1-120) is slower than RNase-(1-118) but much faster than RNase A. Binding with a synthetic complementing fragment (114-124) markedly reduces the exchange rate of 20 to 25 amide protons of RNase-(1-118). It has previously been shown that binding with a complementing fragment of RNase-(1-118) generates a lowest Gibbs energy state. Thus, using available thermodynamic information for interpretation, we suggest that a) removal of six carboxy terminal residues of RNase A would disrupt coupling between these residues and those distant in the structure (loss of extra stabilizing energy), b) this would, in turn, alter the enthalpy-entropy compensation in such a way that the magnitude of Gibbs energy change favoring folding is significantly reduced without a large change of fold and c) in this activated state the molecule would be highly motile.

Disulfides↗
PubMed1986

Role of elements in pathophysiology of hypertension and antihypertensive drug development.

Cadmium and Zinc levels were determined in 100 patients of Essential hypertension by Atomic Absorption Spectrophotometer. It was shown that the mean levels of Serum cadmium were 43.34% +/- 6.5% higher and zinc were 28.42% +/- 5.4% lower in hypertensive when compared with normotensive controls. A statistically significant relationship between the height of diastolic blood pressure and Serum cadmium levels was observed. Ajmaloon a preparation from Rauvolfia serpentina with corrective herbs lowered the blood pressure effectively and significantly P less than 0.001. The side effects were minimal. It also tends to decrease the elevated serum cadmium levels in hypertensive individuals. A plea for development of Catecholamine depleting agents as drug for hypertension is advanced.

Adult↗