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Biomedical subjects

S Metz

Publications and source records attributed to S Metz.

64 records · Page 4Linked to original sources
PubMed1985

Transdermal clonidine therapy in elderly mild hypertensives: effects on blood pressure, plasma norepinephrine and fasting plasma glucose.

Twenty patients aged 60-74 years entered a study on the effect of transdermal clonidine (Catapres-TTS) as monotherapy for mild hypertension [diastolic blood pressure (DBP) 90-104 mmHg]. Seventeen patients (85%) had a positive therapeutic response (DBP reduced to less than 90 mmHg or by greater than or equal to 5 mmHg). Patient acceptance was high and side effects mild; however, one-quarter of the patients experienced localized skin reactions. A slight increase in fasting plasma glucose level (mean delta = 20 mg/dl) was consistently observed. Transdermal clonidine led to a sustained decline in plasma catecholamine levels although this effect did not seem to be closely related to the observed decreases in blood pressure. Three out of four evaluable patients had a blood pressure 'overshoot' upon discontinuation of therapy to levels above pretreatment values. Transdermal clonidine appears to be effective and generally well tolerated in the treatment of mild hypertension in the elderly; however, more studies designed to investigate effects on glucose tolerance and the possible existence of a rebound syndrome are needed.

Administration, Topical↗
PubMed1984

[Pregnancy and delivery in cystic fibrosis].

The authors report about the course of pregnancy and delivery in two patients with cystic fibrosis. Epidemiology and clinical symptoms of cystic fibrosis, possible problems anticipated during pregnancy, delivery and puerperium in patients with cystic fibrosis, and questions concerning therapeutic abortion and contraceptive counseling are discussed. Important premises to the management of pregnancy and delivery in cystic fibrosis have to be: (1) adequate pre- and postpartal diagnosis and therapy of pulmonary and/or cardiac disease, (2) careful management of nutrition, control of pancreatic insufficiency and electrolyte balance, (3) exclusion of maternal diabetes mellitus, (4) sonographic measurements to supervise the development of the fetus, (5) adequate management of delivery, (6) monitoring of puerperium with regard to maternal cystic fibrosis, (7) exclusion of cystic fibrosis in the newborn.

Adult↗
PubMed1984

A controlled comparison of techniques for locating the internal jugular vein using ultrasonography.

Fifteen techniques for localization of the internal jugular vein ( IJV ) were evaluated in each of 25 subjects using ultrasonography to simulate actual cannulation. Ultrasound images were used to determine puncture of the IJV , puncture of the carotid artery (CA), the distance from the skin to the center of the IJV , the width of the IJV lumen, the relationship of the CA to the IJV , and the lateral distance of the IJV from the axis of the sound beam. No technique proved best in successful IJV puncture. Techniques did differ statistically in rates of CA puncture. Techniques using the CA pulse as a landmark had lower CA puncture rates. Rotation of the head, extension of the neck, and breathholding had no influence on IJV cannulation rates. It is concluded that no one technique is clearly superior to the others. Facility with one technique may be more critical to successful cannulation than the technique itself.

Adult↗
PubMed1983

Lipoxygenase pathway in islet endocrine cells. Oxidative metabolism of arachidonic acid promotes insulin release.

Metabolism of arachidonic acid (AA) via the cyclooxygenase pathway reduces glucose-stimulated insulin release. However, metabolism of AA by the lipoxygenase pathway and the consequent effects on insulin secretion have not been simultaneously assessed in the endocrine islet. Both dispersed endocrine cell-enriched pancreatic cells of the neonatal rat, as well as intact islets of the adult rat, metabolized [(3)H]AA not only to cyclooxygenase products (prostaglandins E(2), F(2alpha), and prostacyclin) but also to the lipoxygenase product 12-hydroxyeicosatetraenoic acid (12-HETE). 12-HETE was identified by coelution with authentic tritiated or unlabeled 12-HETE using four high performance liquid chromatographic systems under eight mobile-phase conditions and its identity was confirmed by gas chromatography/mass spectrometry using selected ion monitoring. The predominant effect of exogenous AA (5 mug/ml) was to stimulate insulin release from pancreatic cells grown in monolayer. This effect was concentration- and time-dependent, and reversible. The effect of AA upon insulin release was potentiated by a cyclooxygenase inhibitor (indomethacin) and was prevented by either of two lipoxygenase inhibitors (5,8,11,14-eicosatetraynoic acid [ETYA] and BW755c). In addition, glucose, as well as two structurally dissimilar agents (the calcium ionophore A23187 and bradykinin), which activate phospholipase(s) and thereby release endogenous AA in several cell systems, also stimulated insulin secretion. The effects of glucose, glucagon, bradykinin and high concentrations of A23187 (5 mug/ml) to augment insulin release were blocked or considerably reduced by lipoxygenase inhibitors. However, a lower concentration of the ionophore (0.25 mug/ml), which did not appear to activate phospholipase, was resistant to blockade. Exogenous 12-HETE (up to 2,000 ng/ml) did not alter glucose-induced insulin release. However, the labile intermediate 12-hydroperoxy-ETE increased insulin release. Furthermore, diethylmaleate (which binds intracellular glutathione and thereby impedes conversion of the lipoxygenase intermediates hydroperoxy-ETE and leukotriene A(4) to HETE and leukotriene C(4), respectively) potentiated the effect of glucose and of exogenous AA. Finally, 5,6-epoxy, 8,11,14-eicosatrienoic acid (a relatively stable epoxide analogue of leukotriene A(4)) as well as two other epoxy-analogues, potentiated glucose-induced insulin release. We conclude that dual pathways of AA metabolism exist in islet endocrine cells and have opposing regulatory effects on the beta cell-an inhibitory cyclooxygenase cascade and a stimulatory lipoxygenase cascade. Labile products of the latter pathway may play a pivotal role in stimulus-secretion coupling in the islet.

12-Hydroxy-5,8,10,14-eicosatetraenoic Acid↗
PubMed1982

Donor-specific transfusion with diminished sensitization.

Fourteen mixed lymphocyte culture (MLC)-reactive haploidentical recipients have received donor specific transfusions (DSTs) with diminished sensitization to HLA antigens. A single unit of donor blood was obtained in CPD-A anticoagulant, packed, and transfused in three aliquots at 1-week intervals when the blood was 1, 3, and 5 weeks old. Transplantation, performed 22 to 149 days after the last DST, has been successful in all patients for 3 to 26 months except for one experiencing hyperacute rejection despite a negative crossmatch. In vitro studies suggest that blood storage results in the loss of T lymphocytes, which are presumably responsible for the sensitization, and preservation of B cells and monocytes, which remain capable of stimulating a cellular immune response in vitro throughout the 30-day storage period. Apparently this change in the cellular characteristics of blood with storage produces the salutory effects of blood transfusion without the undesirable sensitization to HLA antigens. The mechanisms remain under study.

Antilymphocyte Serum↗
PubMed1982

Fresh versus stored blood in donor specific transfusion.

Haploidentical, MLC responsive recipients were randomized to receive either fresh (less than 48 hours old) or stored donor specific transfusions (DST). In the stored DST group, one donor unit obtained with CPD-Adenine anticoagulant was split into three aliquots and administered as packed cells after 1, 3, and 5 weeks of storage. While 3/6 fresh DST recipients became sensitized to their donors, 0/12 receiving stored DSTs developed positive donor crossmatches. Eleven patients (three fresh, eight stored) have been transplanted and have had similar posttransplant courses. None of the stored DST recipients has rejected his transplant. Four recipients of stored DSTs are awaiting transplantation. Leukocyte enumeration and FACS analysis of aliquots of stored blood shown that cells bearing HLA-ABC antigens disappear with time while B cells and monocytes persist. Taken in concert, the observations suggest that favorable recipient conditioning for transplantation can take place without sensitization to HLA antigens by simply storing the blood prior to transfusion.

Adolescent↗
PubMedDate not supplied

Thiopental sodium by single bolus dose compared to infusion for cerebral protection during cardiopulmonary bypass.

The authors previously demonstrated that thiopental sodium infused throughout cardiopulmonary bypass (CPB) considerably reduced persistent but not transient neuropsychiatric complications after open-chamber cardiac operations. Based on the probability that emboli released at the time of aortic declamping cause most postoperative central nervous system (CNS) dysfunction, this study was designed to test whether administration of a single bolus dose of thiopental before aortic declamping provided cerebral protection equal to that of infusion throughout bypass as well as a decrease in unwanted side effects. One hundred adult patients undergoing open-chamber cardiac operations with CPB received either thiopental sodium by infusion throughout CPB (n = 52) or thiopental sodium 15 mg/kg by bolus before aortic declamping (n = 48). In 90% of the patients, thiopental sodium 15 mg/kg produced electroencephalographic (EEG) burst suppression, with more than 60 seconds between bursts. Postoperative CNS dysfunction occurred in 3 (6%) of the infusion group patients (thiopental sodium 36 +/- 10 mg/kg) and 2 (4%) of the bolus group patients (thiopental sodium 16 +/- 2 mg/kg). CNS dysfunction persisting to the tenth postoperative day occurred in only one patient, who was in the infusion group. Requirements for inotropic support on separation from CPB did not differ between groups, but average time to extubation was 2.7 hours shorter in the bolus group. The authors conclude that thiopental sodium 15 mg/kg given as a single bolus immediately before aortic declamping without the need for EEG monitoring provided the same brain protection as larger doses given by infusion titrated to burst suppression, but it did not reduce the need for inotropic support during separation from CPB.

Adult↗
PubMedDate not supplied

[Pregnancy and labor in mucoviscidosis--results of a study in Germany].

Thirty-one pregnancies in 27 women suffering from mucoviscidosis have been studied in Germany, in the period from 1980 to 1991. This analysis is the largest collection of data to date relating to pregnancy and birth with mucoviscidosis after the American-Canadian study of 1980. The German study demonstrated that only women with few weak symptoms became pregnant: typically the pregnant women's mucoviscidosis was diagnosed at an average age of 9.2 years, and 96.5% of the women had a satisfactory pregravid Shwachman-Kulczicki-Score. Only minor complications were observed in these pregnancies, in particular pulmonary exacerbations (in 18 pregnancies) and an insufficient weight gain (average of 7.2 kg). Abortions were induced in five pregnancies and no spontaneous were observed. There were of maternal deaths during pregnancy or childbirth. More than one quarter of the newborns were premature. All the children had normal sweat chloride test results. 21 women could breast-feed successfully. In fifteen cases the mother's state of health deteriorated after pregnancy however only to a minor (ten cases) or moderate degree (four cases). It is noteworthy that of the twenty six infants twenty one were male. In this study we obtained the unexpected result that unaffected heterocygous children of women with mucoviscidosis are mainly male.

Adult↗