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Biomedical subjects

M Katz

Publications and source records attributed to M Katz.

At least 451 records · Page 25Linked to original sources
PubMed1981

Reduced sex hormone binding globulin and derived free testosterone levels in women with severe acne.

Reduced circulating sex hormone binding globulin (SHBG) levels were found in 54% of a group of women with moderate to severe acne and in 60% of another group of twenty-three women who had acne complicated by hirsutism and/or irregular menstrual cycles. The concentrations of SHBG for the women with acne alone (mean 48 +/- 24 nmol/l) and for those with acne and hirsutes (mean 39 +/- 18 nmol/l) were compared with the SHBG concentrations of fifteen unaffected women with normal menstrual cycles (mean 70 +/- 19 nmol/l). The differences in mean SHBG values for both groups of women with acne were significant (P less than 0.001) on comparison with the mean for the unaffected women. Twenty-nine per cent of the women with acne had elevated testosterone values (mean testosterone concentration for the group 1.5 +/- 0.3 nmol/l) and 41% had elevated 'derived' free testosterone levels (mean 21 +/- 6 pmol/l). Of the women with acne and hirsutes 65% had elevated plasma testosterone levels (mean 2.1 +/- 0.6 nmol/l) and 89% had elevated free testosterone concentrations (mean 31 +/- 10 pmol/l). The mean values for testosterone and free testosterone in the plasma of unaffected women (mean testosterone concentration 1.1 +/- 0.3 nmol/l and free testosterone 13 +/- 4 pmol/l) were significantly lower than in women with acne alone (P less than 0.01 and P less than 0.001) and in women with acne and hirsutism (P less than 0.001). This study indicates that a deficiency in SHBG and an elevation in 'derived' free testosterone is a frequent finding in women with severe acne and may be a significant factor in the aetiology and/or perpetuation of this condition.

Acne Vulgaris↗
PubMed1981

Serological and biological activities of anti-Haemophilus influenzae ribosomal serum.

The antibody content in serum from rabbits immunized with ribosomes from Haemophilus influenzae type b was determined by passive hemagglutination, enzyme-linked immunosorbent assay, and complement fixation. Attempts to use passive hemagglutination to assay anti-ribosomal antibodies were unsuccessful. In the enzyme-linked immunosorbent assay tests, rabbit antiserum was allowed to react with ribosomes that adhered to microtiter plates. The enzyme-linked immunosorbent assay method detected, in two ribosome-immunized rabbits and by 3 days postimmunization, titers which rose to plateaus on days 24 to 31 and declined thereafter. With the complement fixation method, the serum from one immunized rabbit also showed a titer on day 3 and reached a plateau on days 20 to 31. Serum from the other immunized rabbit did not develop a titer until day 11; it reached a lower plateau on days 20 to 24 and then declined on days 27 to 55. Although there were no apparent differences between the two immunized rabbits by the enzyme-linked immunosorbent assay, there were differences between the complement fixation antibodies in these rabbits. Passive protection experiments were performed with these sera. Maximal passive protection was achieved when mice were challenged intraperitoneally with 100 50% lethal doses of H. influenzae and immunized intravenously 1 h later with rabbit serum collected 27 days postimmunization. Rabbit anti-ribosomal sera were evaluated for bactericidal activity. Undiluted immune sera showed bactericidal activity; however, when diluted 1:10, activity was lost. Although bactericidal activities of immune sera were correlated to passive protection activities, it is unlikely that such protection was due to bactericidal antibodies. Immune serum had opsonizing activity since it enhanced phagocytosis of H. influenzae by mouse leukocytes.

Animals↗
PubMed1981

Blood pressure and pressor response to angiotensin II during pregnancy and nursing in the rabbit.

A continuous study to determine blood pressure and pressor response to angiotensin II (A-2) during pregnancy and postpartum was performed in a chronic rabbit preparation. The resting blood pressure during pregnancy was found to be lower than that in the postpartum period. Pressor response to A-2 was diminished during pregnancy and during nursing, but in the absence of nursing, this response returned to normal values by 1 week postpartum. Inhibition of prostaglandin synthetase caused a significant increase in the pressor response to A-2 during gestation, but did not change the resting blood pressure either before or after delivery. The results are discussed in light of previous animal and human studies, and factors which could affect vascular reactivity during gestation and nursing are analyzed.

Angiotensin II↗
PubMed1981

Mutagenicity of Tris(2,3-dibromopropyl) phosphate in mammalian gonad and bone marrow tissue.

The mutagenic and clastogenic (chromosome breaking) effects of the flame retardant Tris(2,3-dibromopropyl) phosphate (Tris-BP) were investigated in two mammalian in vivo assays, the bone marrow micronucleus test and the abnormal sperm head assay. Two potency of Tris-BP was determined in the Salmonella-mammalian microsome assay. Tris-BP was mutagenic in all three assays, in both mammalian tests, nearly toxic doses were required in B6C3F mice for positive mutagenic and clastogenic results. In the micronucleus test, Tris-BP was a weak clastogen, whereas in the abnormal sperm head assay, Tris-BP was observed to be strongly mutagenic. The abnormal sperm head data might imply genetic damage to germ tissue. The data suggested a means for possibly monitoring Tris-BP exposure. Thus besides being a strong mutagen on bacterial systems, Tris-BP was also a weak clastogen as detected in bone marrow cells and was a mutagen to gonad tissue.

Animals↗
PubMed1981

A functional classification of seizures and its distribution in a mentally retarded population.

A functional classification of seizure impairment was described and its distribution examined in a population classified as mentally retarded in childhood and followed to age 22. Twenty-five percent of the sample had some history of seizures up to age 22. Seizure histories were found for 19 percent of these retarded persons in the preschool years and 13 percent in each period of early, late, and postschool years. A drop in minor seizure impairment occurred after age 5. A slightly higher frequency of seizure histories among males was found, largely due to subjects whose IQs were 50 to 59, where 44 percent of the males and 5 percent of the females had seizure histories. No significant association was found between degree of seizure impairment and severity of mental retardation.

Adolescent↗
PubMed1981

Fetal heart rate patterns and scalp blood pH as predictors of fetal distress.

Repeated samplings of scalp blood pH were obtained from 62 fetuses in whom continuous fetal heart rate monitoring was indicative of fetal distress. In all, 182 scalp blood samples were evaluated. Umbilical cord blood pH was determined immediately after delivery in 48 cases. In addition to heart rate abnormalities, fetal metabolic changes were considered in determining the mode of delivery. Vaginal delivery was allowed in 74.2% of the patient in our series and only 25.8% had cesarean sections. Repeated scalp blood pH sampling proved to be an important adjunct to continuous fetal heart rate monitoring in increasing the accuracy of diagnosis of fetal distress.

Apgar Score↗
PubMed1981

Continuous fetal monitoring following third-trimester amniocentesis.

One hundred forty-six patients were monitored for up to 2 hours after third-trimester amniocentesis. The patterns of uterine and fetal activity, as well as fetal heart rate, were analyzed using the criteria for nonstress and contraction stress testing. There was a clear relationship between these observations and perinatal outcome. Postamniocentesis monitoring was associated with an Apgar score of 6 or less in only 10% of cases with reactive patterns, compared with in 75% of cases with nonreactive patterns and reduced variability and in all cases with late-component deceleration. All cases of immediate fetal jeopardy were detected and there was no fetal loss. Postamniocentesis monitoring appears to offer significant prognostic information for perinatal outcome in high-risk pregnancy.

Amniocentesis↗
PubMed1981

[Multiple chemotherapy (MOPP) followed by either focal or selective radiotherapy in clinical stages IA and II2A of Hodgkin's disease: results after four years of the use of prospective schedule (H 7701) in 79 patients (author's transl)].

Seventy-nine patients with clinical stages IA, or II2A of Hodgkin's disease were treated from January 1977 to April 1980 by a multiple therapy schedule, H 7701. Three courses of MOPP chemotherapy were first given to all patients. They were then randomly allocated to two groups: group 7701 S (38 patients) was treated by mantle irradiation, excluding the mediastinum when this was not initially involved, or inverted Y radiotherapy; group 7701 F (41 patients) was treated by focal irradiation only. After follow-up for 9-48 months (median: 26 months), overall survival was 98,6 p. cent and relapse-free duration 94,9 p cent. No statistical difference exists between the two randomized groups. Four patients relapsed; three are now free of disease after further treatment, while one patient has since died. With this chemotherapy-radiotherapy selective of focal sequence, staging laparotomy is not indicated. Results and side effects of this treatment schedule are compared with those of other treatment strategies.

Adolescent↗
PubMed1980

Increased pressor activity in incubated plasma of pregnant rabbits.

A study to measure the pressor activity which is generated in incubated plasma of pregnant and nonpregnant rabbits was performed by means of a recently modified bioassay technique. It was found that plasma of normal pregnant rabbits generated significantly higher amounts of active pressor principle (APP) than those generated by plasma of nonpregnant rabbits. The possible relevance of these results to blood pressure regulation during normal and abnormal pregnancies is discussed.

Animals↗
PubMed1980

Intravenous dexamethasone for prevention of neonatal respiratory distress: A prospective controlled study.

A trial of intravenous dexamethasone for prevention of neonatal respiratory distress syndrome was carried out prospectively. There were 112 treated and 188 control patients, matched for gestational age, birth weight, rupture of membranes, and antepartum diagnosis. No short-term deleterious effects on mother or infant were demonstrable. There was an increased incidence of cesarean section and puerperal infection in the treated patients. This was not related to the steroid therapy. There was no increased incidence of infection in the treated neonates. At 28 to 33 weeks' gestation, the treated newborn infants had one half the perinatal mortality and one fourth the incidence of severe respiratory distress syndrome seen in the controlls. Under 28 weeks, and from 34 to 36 weeks, no difference between treated and control groups was observed. Intravenous dexamethasone is effective in reducing perinatal mortality from respiratory distress syndrome in premature infants delivered between 28 to 33 weeks' gestation.

Bacterial Infections↗
PubMed1980

Skin perfusion in pregnancy.

Skin perfusion was monitored by photoelectric flow sensing in 42 pregnant and 20 nonpregnant women to obtain direct objective measurements of skin blood flow changes in pregnancy. The skin perfusion was found to increase significantly at the sixteenth gestational week and this increase was maintained at least 1 week post partum. The maximum increase, which was 3 to 4 times the control values, occurred between the twentieth and thirtieth week of gestation. No significant differences were found between normal and hypertensive pregnant patients, but significant decreases in skin perfusion were found in the supine position in patients with a positive "supine pressor test." These results indicate a pattern of increase in skin perfusion during pregnancy which appears to vary inversely with the reported increase in peripheral resistance.

Female↗