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Biomedical subjects

O Martin

Publications and source records attributed to O Martin.

54 records · Page 3Linked to original sources
PubMed1986

Normal ovarian function in a mild form of late-onset 3 beta-hydroxysteroid dehydrogenase deficiency.

Late-onset 3 beta-hydroxysteroid dehydrogenase (HSD) deficiency was diagnosed in a 30-year-old woman with hirsutism and normal menstrual cycles. No genital abnormalities were present. Elevated basal serum levels of delta 5-3 beta-hydroxysteroids were demonstrated. Serum pregnenolone (P5) was 3.0 ng/ml, and dehydroepiandrosterone sulphate (DHEA-S) 3245 ng/ml. Basal serum levels of delta 4 steroids were low or within normal limits. Serum progesterone (P) was 0.5 ng/ml, 17 alpha-hydroxyprogesterone (17-OHP) 0.2 ng/ml, androstenedione (delta 4A) 0.4 ng/ml, and testosterone (T) 0.1 ng/ml. All delta 5/delta 4 steroid ratios were elevated. Dexamethasone (DEX) administration normalized the elevated levels of delta 5-3 beta-hydroxysteroids, whereas delta 4-3-ketometabolites exhibited only minor modifications. The DHEA-S/delta 4A ratio increased more than five times over the basal ratio, and P5/P and 17 alpha-hydroxypregnenolone (17-OHP5)/17-OHP ratios did not increase after adrenocorticotrophic hormone ACTH stimulation. Studies of basal ovarian function revealed 17 beta-estradiol (E2) and gonadotropins within normal limits according to the menstrual cycle. In the follicular phase, follicle-stimulating hormone (FSH) was 101.3 ng/ml, luteinizing hormone (LH) 46.0 ng/ml, and E2 49.7 pg/ml; in the luteal phase, FSH was 180.0 ng/ml, LH 69.3 ng/ml, and E2 50.1 pg/ml. The presence of ovulatory cycles was documented on the basis of the biphasic pattern of the basal body temperature cycles and the increment in P levels. This case demonstrates the existence of normal ovulatory function in a woman with late-onset of a mild form of HSD.

3-Hydroxysteroid Dehydrogenases↗
PubMed1983

Modification of digoxin induced arrhythmogenicity in adult rats following atropine administration.

Atropine alone in the two lower doses (20mg/kg and 40mg/kg) did not produce any arrhythmias while 80mg/kg of atropine produced arrhythmias in 33% of animals after 31.0 +/- 7.5 min. Only 11% of these rats developed paroxysmal atrial tachycardia. Atropine in lower doses (20,40mg/kg) with digoxin (40mg/kg) decreased the total percent of digoxin induced arrhythmias, delayed their onset, and changed the type of arrhythmias as compared with the digoxin group alone. Atropine given in higher dosage (80mg/kg) with digoxin (40mg/kg) produced arrhythmias in 100% of rats as did digoxin alone, but significantly shortened their onset and modified the types of arrhythmias seen. In conclusion, atropine in varying doses significantly modified digoxin toxicity.

Animals↗
PubMed1982

Plasminogen activator production by trophoblast cells in vitro: effect of steroid hormones and protein synthesis inhibitors.

Variations in the production of plasminogen activator (PA), a proteolytic enzyme that has been associated with trophoblast invasiveness, may be critical to the success or failure of placentation. To understand better the mechanisms regulating PA production we have cultured human trophoblast cells and measured the effect of steroid hormones and protein synthesis inhibitors upon their capacity to lyse 125I-fibrinogen. Progesterone (P) and 17 beta-estradiol (E2) at concentrations of 10(-8)M, 10(-7)M, and 10(-5)M did not cause significant changes in PA or chorionic gonadotropin (hCG) production by the trophoblast cells. In contrast, dexamethasone (10(-8)M and 10(-5)M) caused a significant, dose-dependent decrease in PA production. There was no significant difference in PA and hCG production between trophoblast cultures treated with cytosine arabinoside (1 mg/ml) and untreated cultures. When actinomycin D (0.5 microgram/ml) was added to cultures at time zero, the production of PA and hCG during the first 24 hours of incubation was not significantly different from that of untreated cultures. After 24 hours, however, PA and hCG disappeared from the actinomycin-treated cultures while both substances continued to be released in the untreated controls. These experiments indicate that trophoblastic PA and hCG production in vitro are independent of DNA replication and not under P or E2 control. They also show that PA and hCG are stored within the trophoblast cells and released into the medium during the first 24 hours of incubation; after this period the presence of PA and hCG in the medium represents de novo synthesis. The data also suggest that, similar to hCG, PA is produced continuously in vitro as long as the trophoblast cell is functionally active.

Animals↗
PubMed1982

Quantitative electrocardiographic effects of digoxin in newborn and adult rats.

We investigated the age and dose-specific quantitative electrocardiographic effects of digoxin in the rat. Adult female rats (n = 26) and one-day-old newborns (n = 20) were anesthetized with pentobarbital and injected subcutaneously with varying doses of digoxin. Electrocardiograms (ECG) were monitored continuously for four and one-half hours following digoxin administration. PR, QT, and RR intervals, QRS duration (msec), and T amplitude (mm) were measured every 15 minutes in all animals. QTc and PTQ index using the method of Joubert were calculated. Newborns demonstrated significant prolongation of the PR, QT, and RR intervals, an increase in the PTQ index, and a decrease in QTc when compared to adults (receiving the same dosage of digoxin) (P less than or equal to 0.05). In addition they developed toxic changes at much lower doses. Adults developed various tachycardias (tachyarrhythmias) compared to severe sinus bradycardias in the newborns. In conclusion, the newborn rat is much more sensitive to digoxin toxicity than the adult as demonstrated by ECG criteria. The newborns seem to be primarily "parasympathetic" responders as compared to adults who seem to be mainly "sympathetic" responders.

Age Factors↗
PubMed1981

[Isolated intimal stenosis of the renal artery and curable arterial hypertension in Recklinghausen's disease. Association of hypoplastic stenosis of the aortic and pulmonary trunks and sigmoid aortic regurgitation].

The case of a patient with Von Recklinghausen's disease with multiple localisations, cardiac, aortic, pulmonary and renal artery is reported. Neurofibromatosis was confirmed by the presence of a "royal" tumour on the left elbow and of many "café au lait" spots of over 15 mm diameter. There was no craniofacial dysmorphism or intellectual impairment. The karyotype was normal. The cardiovascular lesions comprised: - stenosis of the left renal artery resulting in renovascular hypertension. This was due to pure intimal hyperplasia; - supravalvular aortic stenosis with hypoplasia of the ascending aorta. There was no craniofacial dysmorphism or intellectual impairment. The karyotype was normal. The cardiovascular lesions comprised: - stenosis of the left renal artery resulting in renovascular hypertension. This was due to pure intimal hyperplasia; - supravalvular aortic stenosis with hypoplasia of the ascending aorta. There was no craniofacial dysmorphism or intellectual impairment. The karyotype was normal. The cardiovascular lesions comprised: - stenosis of the left renal artery resulting in renovascular hypertension. This was due to pure intimal hyperplasia; - supravalvular aortic stenosis with hypoplasia of the ascending aorta, severe aortic regurgitation with dilatation of the aortic ring without rheumatic valvular thickening; - supra valvular pulmonary stenosis which was atypical in site, extension and in the absence of post stenotic dilatation. The pressure gradient was mild (22 mm Hg). There was a striking similarity between the pulmonary and aortic lesions. This new syndrome may be classified amongst the genetic cardiocutaneous syndromes such as the Gorlin or "leopard" syndrome, Watson's syndrome and Noonan's syndrome. Unusual features are the absence of craniofacial abnormalities, normal intelligence, and the left-sided dominance aggravated by hypertension due to curable intimal stenosis of the renal artery.

Adolescent↗
PubMed1980

Plasma levels and urinary excretion of orally administered propantheline bromide in man.

After a single oral dose of 30 or 60 mg of propantheline bromide peak plasma levels of the drug were reached within 2 h in six healthy men. Mean peak plasma concentrations were 20.6 and 53.1 ng/ml after 30 mg and 60 mg respectively. The mean apparent absorption and elimination half-lives after 30 mg dose were 0.22 and 1.57 h respectively, and similar half-lives were found at the higher dose level. There was a dose related change in plasma levels and AUCinfinity of the drug, and some 3% to 4% of the administered dose of propantheline bromide was excreted unchanged in urine at each dose level. Comparison of the plasma levels and urinary excretion of the drug with those seen after i.v. administration in an earlier study indicated an apparently low systemic availability of orally administered propantheline bromide. There was tentative evidence of a qualitative relationship between the oral dose administered, plasma concentrations and the effects of propantheline bromide on salivary excretion.

Administration, Oral↗
PubMed1979

Is the low fertility rate after vasovasostomy caused by nerve resection during vasectomy?

Cross-sections of human spermatic cords and vasectomy specimens were prepared and the number and cross-sectional area of nerves were determined. On average, about one-half of all nerves in the near neighborhood of the vas deferens were resected during vasectomy. The total cross-sectional area of the nerves along the vasectomy specimens amounted to about one-half of the total area in the spermatic cord samples. The data support the hypothesis that removing nerves to the vas deferens during vasectomy could result in poor functional results after vasovasostomy, i.e., that powerful contraction of the proximal vas deferens and epididymis could be lacking.

Denervation↗
PubMed1979

The history of the artificial eye.

The history of the artificial eye, from antiquity to the present, is described. Around the beginning of the nineteenth century, glass eyes replaced the earlier metal ones--not always well tolerated. In 1835, cryolite glass was used instead of lead glass; to this day it remains the lightest and most desirable substance for making artificial eyes.

Eye, Artificial↗
PubMed1977

[Residual dyslipoproteinemias after ethanol-weaning in alcoholic hyperlipidemic patients (author's transl)].

Twenty-two hyperlipidemic and long-term alcoholic patients were chosen as subjects with a chronic alcohol-dependent hyperlipoproteinemia, since their lipidemia was getting normal after they stopped alochol ingestion. After ethanol-weaning of these subjects, we found quantitative abnormalities of lipidemia (hypocholesterolemia in 5 cases among 22) and qualitative abnormal electrophoretic patterns in all cases: There is always a VLDL stain, a reduction of the LDL and VLDL migration. These facts suggest that exists in these patients a constant abnormality either in the enzymatic, or in the lipoprotein structures, which is induced or revealed by alcohol ingestion.20

Alcoholism↗