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Biomedical subjects

S Roy

Publications and source records attributed to S Roy.

At least 775 records · Page 43Linked to original sources
PubMed1981

Effects of a progesterone-releasing intrauterine contraceptive device on endometrial blood vessels: a morphometric study.

The concentration of microscopically detectable blood vessels was significantly lower in endometrium exposed to progesterone-releasing intrauterine contraceptive devices (IUDs) than in control endometrium (mean vessel density 2.39 and 3.92, respectively). The percentage of vessels with defects was significantly higher in IUD samples (35.0%) than in control samples (13.4%). There was no significant difference in hemostatic response to vessel injury between the IUD and control samples. Although they were more defective than in controls, the blood vessels of progesterone IUD-exposed endometrium were far fewer in number, which may account for significantly less uterine blood loss in the users of these devices. In addition, the progesterone IUDs do not appear to inhibit hemostasis in the endometrium so that blood loss from injured vessels may be minimized.

Endometrium↗
PubMed1981

Purification and properties of mouse pyruvate kinases K and M and of a modified K subunit.

The K4 and M4 isozymes of mouse pyruvate kinase were purified to homogeneity, and their physical, chemical, and kinetic properties were compared. The K isozyme is slightly larger, but a high degree of homology exists as evidenced by a similar amino acid composition, immunotitration value, and two-dimensional arginine peptide pattern after tryptic digestion. Also, the more active conformational form of the K isozyme has kinetic and chromatographic properties similar to those of the M isozyme. Only K subunit could be extracted with antibody from fresh spleen extracts, but this subunit can be cleaved to form a product with the mobility of the M subunit. The cleavage is accomplished by an endogenous enzyme and appears to be the first step in K-enzyme degradation. This product is called Kpm . KpmK hybrid could also be purified to homogeneity. This enzyme has the structure K2pmK2, and both types of subunit have activity. The Kpm form has a higher K0.5S value for phosphoenolpyruvate and a lower K0.5S value for ADP than does either the K or the M type. However, the Kpm and M subunits otherwise have very similar properties and it is speculated that the Kpm subunit is an M-type precursor.

Amino Acids↗
PubMed1981

Pathology of rabies: a light- and electron-microscopical study with particular reference to the changes in cases with prolonged survival.

Light- and electron-microscopical studies were conducted on necropsy material from six cases of rabies encephalitis including three with the unusual feature of surviving for over 14 days as a result of intensive medical care. This included administration of antiviral agents and interferon inducers and prevention of hypoxia by intermittent positive pressure ventilation. In all these cases, typical Negri bodies were demonstrated. Inflammatory reaction was absent or minimal. Unlike the cases with short survival where Negri bodies were infrequently seen and restricted mostly to the hippocampus, in cases with prolonged survival, they were present in large number, widely distributed throughout the grey matter of the brain. The associated inflammatory reaction in these cases, however, did not keep pace with the increase in number of inclusion bodies. Peripheral neuritis was observed in two of these cases, which also showed myelitis involving the cervical region and inflammation of dorsal root ganglia. One of them showed necrosis and severe inflammation of the lower cervical sympathetic ganglion. An electron-microscopical study conducted in four cases showed three forms of the inclusion body in the cytoplasm of neurons.

Brain↗
PubMed1981

A multicenter study of levonorgestrel-estradiol contraceptive vaginal rings. II-Subjective and objective measures of effects. An international comparative trial.

Comparative clinical trials of 2 sizes of contraceptive vaginal rings and of an oral contraceptive were undertaken at 8 investigational sites (9 clinics). More than 500 women enrolled on each of the 3 study regimens. Side effects of the rings and of Nordette, the oral contraceptive, were evaluated by noting spontaneous complaints, by recording medications taken and by physical examination. Inquiries about changes in the frequency of specific conditions were made at the end of the subjects participation in the first year of the study. The incidence of spontaneous complaints was similar among users of the 2 different-sized rings and of the pill.

Adolescent↗
PubMed1981

A multicenter study of levonorgestrel-estradiol contraceptive vaginal rings. III-Menstrual patterns. An international comparative trial.

Menstrual events among users of contraceptive vaginal rings (CVRs), releasing levonorgestrel and estradiol, were studied in comparison with a combined oral contraceptive, Nordette, in multicentered trials. CVRs were made with outside diameters of 50 and 58 mm and released about 250 micrograms and 290 microgram of levonorgestrel and 150 microgram and 180 microgram of estradiol per day, respectively. The CVRs were used continuously for 3 weeks and then removed for 1 week. Both the CVRs and Nordette were perceived to reduce menstrual flow and days of menstrual bleeding. Twenty to 25% of CVR users perceived increased intermenstrual bleeding or spotting. Diaries indicate, however, that on average, CVR users experienced about 1 day per month of bleeding or spotting with the ring in place. CVRs and Nordette produced approximately the same total number of bleeding and spotting days during 6 cycles of use, 27-29, but the small (50-mm OD) ring was associated with somewhat more spotting. This ring was also associated with somewhat more prolonged bleeding and spotting runs and with more prolonged nonbleeding intervals than reported by users of the larger (58-mm OD) ring or of Nordette. Differences among regimens, however, tended to be small even when statistically significant. Evidence from menstrual diaries indicates that these CVRs, and in particular 58-mm ring, provide control over the menstrual cycle comparable to the Nordette.

Adolescent↗
PubMed1981

The effect on lipids and lipoproteins of a contraceptive vaginal ring containing levonorgestrel and estradiol.

Lipids and lipoproteins were studied in controls and women using contraceptive vaginal rings (CVRs). The groups were comparable for race, age, parity, obesity indices, alcohol ingestion, smoking, diet and exercise. Fasting blood samples were obtained twice before CVR treatment, after 2 and 7 weeks of treatment and 1 week thereafter. The women using the CVR had a significant incremental reduction of cholesterol from baseline to treatment which was distributed among all the lipoprotein classes. The cholesterol/HDL-C ratio was significantly increased with treatment. All mena changes were within the reference range. The reduction in HDL and especially in the subclasses HDL 2a and HDL 2b were significant and outside the reference range. The LDL/HDL ratio increased significantly, while the LDL/HDL 2a+2b ratio increased significantly outside the reference range with treatment. Of the lipid and lipoprotein measurements that changed significantly with treatment, HDL-C, HDL, HDL 2a LDL/HDL and LDL/HDL 2a+2b changed significantly towards baseline in the 1-week-off treatment. The potential reduction in predicted coronary risk with the use of the CVR suggested by a reduction in cholesterol was counterbalanced by a reduction in HDL-C and increases in the cholesterol/HDL-C and LDL/HDL ratios. The potential clinical implications of these findings remain to be determined.

Adult↗
PubMed1981

The effect of a contraceptive vaginal ring and oral contraceptives on the vaginal flora.

Premenopausal women seeking a steroid contraceptive method were allowed to choose between a contraceptive vaginal ring (CVR) containing levonorgestrel and estradiol used in a 3-week in, 1-week out regimen (n=20) and an oral contraceptive (OC) containing levonorgestrel and ethinyl estradiol in a 28-day regimen (n = 10). Cultures from the posterior vaginal fornix were obtained before therapy in both groups and monthly for 6 months for the CVR group and after 1, 3, and 6 months for the OC group. These cultures were streaked on specific media to provide quantitative aerobic and anaerobic, lactobacillus, Candida sp., Gardnerella vaginalis and Neisseria gonorrhoeae counts in micro-organisms per milliliter. A comparison of the number and types of organisms isolated from vaginal cultures obtained initially and at 6 months demonstrated no statistically significant differences in colony counts between CVR and OC users. The results of this study suggest that the use of the CVR is not associated with a greater growth of pathogens than is oral administration of a progestin and estrogen combination.

Adult↗
PubMed1981

Termination of early gestation with (15S)-15-methyl prostaglandin F2 alpha methyl ester vaginal suppositories.

Vaginal suppositories containing (15S)-15-methyl prostaglandin F2 alpha methyl ester were administered to 40 subjects, in an attempt to induce an early abortion. All subjects were 49 days or less from their last menstrual period. Ten subjects received a 3-mg suppository followed in 3 hours by a 1 mg suppository, ten subjects received the 1-mg suppository followed in 3 hours by a 3-mg suppository, and twenty subjects received the 3-mg suppository followed in 1 hour by the 1-mg suppository. Twenty-four subjects (60%) had a successful termination of their pregnancy using the two vaginal prostaglandin suppository regimen. All subjects who aborted had 10 percent or less of their pretreatment levels of beta-hCG 7 to 22 days after therapy. Sixteen subjects (40%) did not abort. One of the subjects who failed treatment refused the second suppository due to gastrointestinal side effects and uterine cramping following the insertion of the 1-mg suppository. A second subject had an incomplete abortion and developed mild endometritis. Sixteen subjects reported side effects which included nausea, emesis, diarrhea, uterine cramping requiring analgesia, restlessness, shakiness, and dizziness. The addition of the second vaginal suppository containing this particular prostaglandin analogue did not significantly increase the overall abortifacient activity of this method.

Abortion, Induced↗
PubMed1981

Correlation of Ovutron readings and the basal body temperature (BBT) with serum sex-hormone and luteinizing hormone levels.

Prior studies have produced conflicting results about whether a change in electric potential occurs at the time of ovulation. This study was undertaken to determine whether the Ovutron, a digital voltmeter which displays the sign and magnitude of voltage measured when the index fingers are applied to the electrodes, would produce a mix in polarity, some positive and some negative voltages, with 5 consecutive measurements preceding ovulation. This device was used daily in 10 normally ovulating women to determine whether such a mix in polarity occurred during the menstrual cycle and its relationship to the corresponding daily measurements of luteinizing hormone, total immunoreactive estrogen (IRE) and progesterone heralding and confirming ovulation. In addition, the Ovutron readings were compared to the basal body temperature (BBT) measurements. In 8 of 10 women studied with the Ovutron device, a mix in polarity was observed in 2 of 3 consecutive days preceding ovulation and was associated in all but 2 subjects with a 50 pg/ml/day incremental increase in IRE. By comparison, only 4 of the 10 subjects had a "classic" biphasic BBT curve. This novel device should be evaluated in a large group of women employing these and other additional parameters (e.g., ultrasonography) in order to determine its efficacy and whether it has a role in the treatment of infertility as well as contraception.

Adolescent↗
PubMed1981

In vivo effects of leukotriene B4, C4 and D4. Evidence that changes in blood pressure are mediated by prostaglandins.

Intra-jugular nanomole injections of leukotrienes B4, C4 and D4 (LTB4, LTC4, LTD4) in anesthetized guinea-pigs have been shown to cause dose-dependent increases of the mean arterial blood pressure. While the responses to LTB4 were monophasic, the responses to LTC4 and LTD4 were characterized by a fast (10-50 sec), medium high, first pressor phase followed by a second, longer lasting (3-9 min), more important pressor phase. Like antigen-antibody reactions, leukotrienes induced cardiac effects such as tachycardia and rhythm disturbances as well as respiratory difficulties, convulsions and sometimes death of the animals. The prostaglandin synthesis inhibitor, indomethacin, reduced the pressor response and the tachyarrhythmic effects of LTB4, C4 and D4. These results raise the possibility that leukotrienes produce their hemodynamic effects in guinea-pigs by stimulating the synthesis and release of biologically active derivatives of arachidonic acid.

Animals↗
PubMed1981

The lung parenchymal strip as a sensitive assay for leukotriene B4.

Leukotriene B4 (LTB4) (3 X 10(-11) to 1.5 X 10(-9) mole; 10 ng to 500 ng) contracted the guinea-pig lung parenchymal strips in a dose-dependent manner. The contractile effect of LTB4 was not affected by methysergide (0.2 microgram/ml), propranolol (3.0 microgram/ml), phenoxybenzamine (0.1 microgram/ml), atropine (0.1 microgram/ml), diphenhydramine (0.1 microgram/ml) and FPL-55712 (1.0 microgram/ml), but was nearly completely abolished by indomethacin (20 microgram/ml). It is concluded that the contraction of the parenchymal strip to LTB4 may constitute a simple, sensitive and selective bioassay which could be either used for the determination of LTB4 in biological material or for studies on structure-activity relationship.

Animals↗
PubMed1981

Pharmacological activity of leukotrienes A4, B4, C4 and D4 on selected guinea-pig, rat, rabbit and human smooth muscles.

The myotropic activity of leukotrienes A4, B4, C4, D4 and histamine has been evaluated on selected smooth muscle preparations. LTA4, B4, C4 and D4 were several times more potent than histamine on the guinea-pig lung parenchymal strip, while on the guinea-pig trachea, LTB4 was less active. The guinea-pig ileum either in segments or in strips of longitudinal muscles responses well to LTC4, LTD4 and histamine but not to LTA4 and LTB4. Rat and rabbit lung parenchymal strip showed very little sensitivity for leukotrienes whereas human parenchymal strips and bronchi were nearly as sensitive as the guinea-pig lung.

Animals↗
PubMed1981

Hematuria preceding renal calculus formation in children with hypercalciuria.

Five children were evaluated for painless hematuria; currently recommended diagnostic studies were unsuccessful in determining a diagnosis. A renal calculus subsequently was passed or detected radiographically in each child from 14 to 20 months after the initial evaluation. Hypercalciuria was then demonstrated by quantitation of 24-hour urinary calcium excretion or by measurement of urinary calcium/creatinine ratio. Calculi and hematuria have not recurred following thiazide therapy. We infer that idiopathic hypercalciuria was a probable cause of the unexplained painless hematuria.

Calcium↗
PubMed1981

Poststreptococcal crescenteric glomerulonephritis in children: comparison of quintuple therapy versus supportive care.

Crescenteric glomerulonephritis preceded by a streptococcal infection with creatinine clearance CCr of less than 30 ml/minute/1.73 m2 was treated by supportive care plus three months of quintuple therapy (prednisone, azathioprine, cyclophosphamide, dipyridamole, and heparin followed by warfarin) in five children (Group A) or by supportive care alone in five others (Group B). Of the glomeruli examined, 69.8 +/- 11.7% (mean +/- SE) in Group A and 64.4 +/- 10.6% in Group B had crescents which involved 54.0 +/- 10.8% and 60.0 +/- 10.5% of glomerular circumference, respectively. Clinical and histologic findings supported a recent streptococcal infection in every patient. Two patients from Group A had mild proteinuria and normal CCr at 12 months; one died abruptly of pulmonary hemorrhage after maintaining a normal CCr for 25 months. Following a second episode of poststreptococcal acute glomerulonephritis seven months after the first, one patient from Group B had persistent mild proteinuria for 41 months and hypertension through 56 months of follow-up. Nine surviving patients have maintained normal CCr for eight to 60 months (mean 29.5 months). The findings of this study suggest that this quintuple therapy offers no advantage over supportive care in the clinical management and outcome of children with severe crescenteric glomerulonephritis when an antecedent streptococcal infection is confirmed by serologic and histopathologic criteria.

Adolescent↗