Search PubMed⌕ Search

Biomedical subjects

K J Ryan

Publications and source records attributed to K J Ryan.

At least 91 records · Page 5Linked to original sources
PubMed1983

Effects of insulin on steroidogenesis in cultured porcine ovarian theca.

The effects of insulin on porcine thecal steroidogenesis were examined in long-term cultures of hyaluronidase-collagenase dispersed thecal cells. The thecal cultures made significant amounts of progesterone (P) and androstenedione (delta 4 A). Testosterone, dihydrotestosterone, estrone, and estradiol could not be detected in the media. Luteinizing hormone (LH) alone significantly increased P and delta 4 A accumulation. Insulin alone increased P accumulation on days 2 to 4 of culture. Insulin alone did not stimulate delta 4 A accumulation. Insulin plus LH resulted in a significantly greater accumulation of P and delta 4 A than LH alone. These results suggest that insulin may be a regulator of ovarian thecal steroidogenesis.

Androstenedione↗
PubMed1983

Determinants of ovarian cancer risk. I. Reproductive experiences and family history.

Reproductive experiences and family history were assessed in 215 white females with epithelial ovarian cancer and in 215 control women matched by age, race, and residence. Pregnancy exerted a strong protective effect against ovarian cancer, which increased with the number of live-born children. After adjustment for parity, an effect of age at first live birth and breast-feeding was not apparent. Menstrual events did not differ significantly between cases and controls, although cases were more likely to have had an earlier menopause and less likely to have had a surgical menopause. Women with ovarian cancer had more frequently used menopausal hormones in cyclic fashion compared to controls. Regarding family history, women with ovarian cancer more frequently reported consanguinity in their ancestry and a highly frequency of primary relatives with cancer of the colon, lung, ovary, and prostate gland.

Consanguinity↗
PubMed1982

Delay in conception for former 'pill' users.

Interview data from 3,214 married women having planned pregnancies and singleton deliveries who had no history of fertility treatment and who conceived more than two weeks after cessation of contraception were analyzed. The interval from cessation of contraception to conception was 13 months or greater for 24.8% of prior "pill" users vs 10.6% for former users of all other methods. As compared with former users of other methods, pill users had a notably lower monthly percentage of conceptions for the first three months and somewhat lower percentage from four to ten months. Results were not altered when potential confounding variables were controlled by logistic regression. At least 15 months of unsuccessful trials might be a more appropriate working definition of infertility for previous pill users rather than the 12-month interval generally accepted for this purpose.

Adult↗
PubMed1982

No association between coffee consumption and adverse outcomes of pregnancy.

We analyzed interview and medical-record data of 12,205 non-diabetic, non-asthmatic women to evaluate the relation between coffee consumption and adverse outcomes of pregnancy. Low birth weight and short gestation occurred more often among offspring of women who drank four or more cups of coffee a day and more often among the offspring of smokers. After controlling for smoking, other habits, demographic characteristics, and medical history by standardization and logistic regression, we found no relation between low birth weight or short gestation and heavy coffee consumption. Furthermore, there was no excess of malformations among coffee drinkers. These negative results suggest that coffee consumption has a minimal effect, if any, on the outcome of pregnancy.

Adult↗
PubMed1982

Endometrial hyperplasia in women on cyclic or continuous estrogen regimens.

Twenty-five symptomatic postmenopausal women with an intact uterus were assigned in random double-blind fashion to receive 0.625 mg of conjugated estrogens on either a cyclic (3 weeks on, 1 week off) or continuous (daily) basis. The incidence of endometrial hyperplasia as demonstrated by screening biopsies at 6 and 12 months of therapy was 4.5 per 100 woman-months in the cyclic group and 3.7 per 100 woman-months in the continuous group (a difference not statistically significant). Thus, in this study, cyclic therapy was found to offer no advantage over continuous therapy. In our opinion, the rate of hyperplasia development in both groups unacceptably high, and efforts must be directed at reducing its incidence primarily.

Biopsy↗
PubMed1982

CGA-72662--a new sheep blowfly insecticide.

The efficiency of 2-cyclopropylamino-4, 6-diamino-s-triazine CGA-72662 (proposed common name: cyromazine) for the control of blowfly strike was tested in fly cage and field trials on sheep. The safety to sheep and physico-chemical properties of the compound as they relate to blowfly control were also assessed. When the sheep were thoroughly jetted with a solution of CGA-72662 containing 1g of active ingredient per litre, the mean incidence of fly strike in 7 field trials was reduced from 16.5% to 1.5% over a period of 9 weeks. The incidence of strike in the treated sheep in 2 insectary tests, which imposed levels of fly activity far in excess of that usually encountered in the field, was reduced from 93% and 73% in untreated sheep to 2% and nil respectively over a period of 8 weeks. Jetting with CGA-72662 solutions 100 times greater than the recommended concentration did not produce any side effects in sheep. Three treatments at twice the recommended concentration during the first trimester did not affect pregnant ewes nor their progeny. The compound was safe to use in combination with common anthelmintics and with sheep dips used for control of lice. CGA-72662 was stable in solution. No stripping occurred in dips and it persisted on wool for a considerable period. A satisfactory alternative to the organophosphorus insecticides has been found in CGA-72662, since it provided a substantial increase in residual protection against blowfly strike with a high degree of safety.

Animals↗
PubMed1982

Rapid automated identification of gram-negative bacilli from blood cultures with the AutoMicrobic system.

Automated identification of gram-negative bacilli directly from blood culture bottles by using the AutoMicrobic System (AMS) was evaluated with a modified procedure for the AMS Enterobacteriaceae-plus nonfermenter identification card. A total of 150 strains were tested (44 clinical and 106 seeded) and compared with a conventional identification procedure. These strains included 107 Enterobacteriaceae and 43 oxidase-positive or glucose-nonfermenting, or both, organisms. AMS identifications on one of these strains were not interpretable owing to equal probability AMS identification values. Of the remaining 149 strains, 138 (92.6%) were correctly identified within 8 to 13 h of the first reading. Of 69 identifications analyzed after 6 h of incubation, 91% were correct. This procedure was found to be rapid, convenient, and nonlabor intensive and is recommended for presumptive identification of gram-negative bacilli in blood cultures.

Bacteria↗
PubMed1982

Determinations of endogenous immunoreactive luteinizing hormone-releasing hormone in human plasma.

A specific and sensitive RIA was developed for measuring immunoreactive LHRH (IR-LHRH) in methanol acid-extracted human plasma. Heparinized blood samples were obtained from normal adult women and men, and the plasma was extracted with methanol, acidified, lyophilized, and stored at -20 C until assayed for LHRH. The lowest detectable levels of IR-LHRH in 1.0-3.5 ml methanol acid-extracted plasma ranged from 0.975-1.95 pg/assay tube, and recovery of synthetic LHRH from plasma averaged 88.6 +/- 2.4% (SE). Gel chromatographic separation analysis revealed comparable elution peaks for endogenous, tritiated, and synthetic LHRH. The plasma extract was also effective in evoking the release of LH and FSH in vitro using isolated rat hemipituitaries. IR-LHRH levels in human peripheral plasma rose 50-fold within seconds after an iv bolus injection of 100 micrograms synthetic LHRH with a return to baseline within 60 min. When the pattern of IR-LHRH secretion in peripheral plasma was studied, episodes of IR-LHRH rise were observed approximately every 60 min in both men and women. The physiochemical and biochemical properties of IR-LHRH suggest that it is an authentic LHRH. The presence of pulses of IR-LHRH suggests that its concentration in peripheral blood reflects changes in levels in the pituitary portal blood.

Adult↗
PubMed1982

Ectopic pregnancy and prior induced abortion.

We compared the prior pregnancy histories of 85 multigravid women with an ectopic pregnancy and 498 multigravid delivery comparison subjects. We found a relationship between the number of prior induced abortions and the risk of ectopic pregnancy: the crude relative risk of ectopic pregnancy was 1.6 for women with one prior induced abortion and 4.0 for women with two or more prior induced abortions; however, use of multivariate techniques to control confounding factors reduced the relative risks to 1.3 (95 per cent confidence interval, 0.6-2.7) and 2.6 (95 per cent confidence interval, 0.9-7.4), respectively. The analysis suggests that induced abortion may be one of several risk factors for ectopic pregnancy, particularly for women who have had abortions plus pelvic inflammatory disease or multiple abortions.

Abortion, Induced↗
PubMed1982

Biochemistry of aromatase: significance to female reproductive physiology.

The formation of estrogens in mammals via aromatase involves the relatively unique capacity to form an aromatic ring de novo in contrast to most other aromatic substances (essential amino acids) which are obtained only in the diet. The reaction is the only example of a cytochrome P450 system which resides in both the mitochondrial and microsomal fractions of the cell. It occurs widely throughout the body in diverse tissues and functions via both de novo synthesis and transformation of prehormones (androstenedione and testosterone). It is found widely in animal species in both the brain and gonads even in phylogenetically primitive species. Placental aromatase appears to be associated with the evolution of viviparity and an extended gestational period in utero. Follicular aromatase which is dependent upon follicle-stimulating hormone stimulation appears to be essential for oogenesis, ovulation, and normal luteal functions while central nervous system aromatase serves to determine sexual behavior and the neurohormonal link to the hypothalamus and pituitary for ovarian cyclicity. While estrogens are the key to pituitary, breast, and endometrial growth and development, this hormone is one of the few examples of an endogenous steroid that has been implicated as a carcinogen or a stimulant for carcinogenesis.

Aromatase↗
PubMed1981

Danazol: endocrine pharmacology and therapeutic applications.

The options for the medical management of endometriosis have been expanded by the introduction of the synthetic steroid, danazol. The results of large clinical studies suggest that danazol treatment produces significant improvement in the symptoms, signs, and laparoscopic findings of endometriosis. The original studies of the pharmacology of danazol concluded that danazol was a strong antigonadotrophin with mild androgenic effects and no other hormonal properties. Recent studies which emphasize the molecular pharmacology of danazol suggest that this steroid has direct effects on hypothalamic-pituitary function, multiple classes of steroid receptors, gonadal steroidogenesis, and endogenous steroid metabolism. These studies demonstrate that: (1) danazol prevents the midcycle surge of luteinizing hormone (LH) and follicle-stimulating hormone (FSH); (2) danazol does not significantly suppress basal LH or FSH in gonadally intact human beings; (3) in castrated animals danazol can prevent the compensatory increase in LH and FSH; (4) danazol binds to androgen, progesterone, and glucocorticoid receptors; (5) danazol does not bind to estrogen receptors; (6) danazol binds to sex hormone-binding globulin and corticosteroid-binding globulin; (7) danazol inhibits multiple enzymes of steroidogenesis; (8) danazol increases the metabolic clearance rate of progesterone; and (9) metabolites of danazol are hormonally active. Given the complex pharmacology of danazol it is inappropriate to continue to refer to danazol as a "selective antigonadotrophin."U

Animals↗
PubMed1981

Objective evidence that placebo and oral medroxyprogesterone acetate therapy diminish menopausal vasomotor flushes.

The vasomotor flush (VMF) is the most common reason for menopausal women to seek hormonal therapy, but the evaluation of therapeutic regimens has been hampered by the observation that placebo therapy can decrease VMF and, until recently, by a lack of objective criteria of measurement of the VMF. Using the objective criteria of temperature elevations (TEs) and luteinizing hormone (LH) pulses, we evaluated the effect of placebo and medroxyprogesterone acetate (MPA) on VMF. MPA and possibly also placebo were found to reduce not only the subjectively noted VMF but also the frequency of TEs recorded. In addition, MPA, but not placebo, significantly reduced the frequency and amplitude of LH pulses. Possible mechanisms of action of MPA and placebo therapy are discussed.

Body Temperature↗
PubMed1981

Catecholamines in human amniotic fluid.

This study was undertaken to determine the amniotic fluid levels of epinephrine (E), norepinephrine (N), and dopamine (D) at different gestational ages in the human. Amniotic fluid obtained from 32 pregnant women undergoing amniocentesis for medical indications was analyzed with a radioenzyme assay for these catecholamines. The gestational ages ranged from 17 to 39 weeks. No patient was in active labor at the time of amniocentesis. The data obtained in this study demonstrated a rise of all three catecholamines at the end of the third trimester: N = 362.7 +/- 61.2 pg/ml (+/- SEM), E = 179.6 +/- 45.4 pg/ml (p < 0.05), and D = 2717.0 +/- 836.6 pg/ml (p < 0.01). The physiologic role for the increasing amounts of catecholamines, especially D, in amniotic fluid is known; however, these amines could be the stimulus for the intrauterine synthesis of prostaglandins as parturition approaches.

Amniotic Fluid↗
PubMed1981

Shigella sepsis.

It is generally believed that bacteremia rarely occurs with enteric Shigella infections. During a five-year period, 110 children were admitted to the University Hospital of the Arizona Health Sciences Center, Tucson, with Shigella enteritis. Eight (7%) had Shigella bacteremia/septicemia, and four of the eight died. An analysis of these patients and their course disclosed clinical characteristics that were of potential prognostic importance. Some of these indicators are identifiable early and hence could be useful in management. The patients at greatest risk were afebrile; 10% or more dehydrated; malnourished, with a low serum albumin level; infected with ampicillin-resistant strains; had leukopenia during the course of the illness; and had persistent watery hemoglobin-positive stools.

Child, Preschool↗