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Biomedical subjects

B Spitz

Publications and source records attributed to B Spitz.

At least 55 records · Page 3Linked to original sources
PubMed1991

Measurement of individual plasma angiotensins in normal pregnancy and pregnancy-induced hypertension.

Individual angiotensin peptides were measured by a high pressure liquid chromatography-RIA (HPLC-RIA) technique in the plasma of 20 nonpregnant women, 17 women with normal pregnancy, and 49 with pregnancy-induced hypertension. Immunoreactive angiotensin-II (ANG-II) consisted mainly of ANG-(1-8) octapeptide (greater than 65%), variable proportions (15-25%) of ANG-(4-8) pentapeptide, and small to negligible proportions of ANG-(2-8) heptapeptide and ANG-(3-8) hexapeptide. Levels of ANG-(1-8) were significantly higher in women with normal pregnancy than in both nonpregnant women (P less than 0.0006) and women with pregnancy-induced hypertension (P less than 0.008); in the latter, levels were lower with increasing severity of disease. Levels of ANG-(4-8) were higher in women with normal pregnancy than in women with pregnancy-induced hypertension or nonpregnant women. When expressed as a proportion of ANG-(1-8) levels, however, ANG-(4-8) levels were not higher in normal pregnancy than in women with pregnancy-induced hypertension or nonpregnant women. It is concluded that the well known increase in ANG-II levels in normal pregnancy relates predominantly to the active ANG-(1-8) octapeptide and to a far lesser extent to the smaller ANG peptides. Similarly, lower ANG-II levels in pregnancy-induced hypertension relate predominantly to lower ANG-(1-8) levels.

Adult↗
PubMed1990

Low-dose aspirin. II. Relationship of angiotensin II pressor responses, circulating eicosanoids, and pregnancy outcome.

Forty pregnant women (28 to 32 weeks' gestation) were given low-dose aspirin therapy (81 mg/day) from the time of enrollment until delivery; circulating eicosanoid levels and angiotensin II pressor responses were measured before and after 1 week of aspirin therapy. Subsequent clinical outcome was correlated with these results. All women had significant reductions in serum and plasma thromboxane B2 levels with aspirin treatment (p less than 0.01). Eleven women who remained sensitive to the pressor effects of angiotensin II (effective pressor dose less than 10 ng/kg/min) after 1 week of low-dose aspirin treatment exhibited significant decreases (p less than 0.05) in plasma 6-keto-prostaglandin F1 alpha (264 +/- 119 vs 161 +/- 31 pg/ml, mean +/- SD) and prostaglandin E2 (476 +/- 174 vs 351 +/- 112 pg/ml) levels. In contrast, patients who were either nonsensitive (refractory) to angiotensin II (n = 18; greater than or equal to 10 ng/kg/min) before aspirin or became nonsensitive after aspirin administration (n = 11) had no change in either plasma 6-keto-prostaglandin F1 alpha or prostaglandin E2 concentrations. The occurrence of pregnancy-induced hypertension was 100% in the women who remained angiotensin II sensitive during aspirin therapy as compared with 36% and 39% in the other two groups (x2 = 16.14; p less than 0.001). Thus during low-dose aspirin therapy a failure to develop refractoriness to infused angiotensin II is associated with a nonselective inhibition of eicosanoids and the almost certain development of pregnancy-induced hypertension. These observations may reflect a basic defect in vascular adaptation to pregnancy.

6-Ketoprostaglandin F1 alpha↗
PubMed1990

Perinatal growth hormone (GH) physiology: effect of GH-releasing factor on maternal and fetal secretion of pituitary and placental GH.

To study regulation of the secretion of human pituitary GH (hGH) and placental GH (hPGH) in the pregnant woman and human fetus, the GH-releasing factor Sermorelin [GRF-(1-29)-NH2] was administered to pregnant women at term (n = 5), just before elective cesarean section; saline was administered in control studies (n = 5). The effects of GRF-(1-29)-NH2 administration on maternal and fetal serum concentrations of hGH and GRF-(1-29)-NH2 and maternal serum levels of hPGH were evaluated at birth. The mean time span between injection and birth was 20 min (range, 15-25 min). Cord serum hGH concentrations were similar in infants of GRF-(1-29)-NH2-injected mothers and control infants. GRF-(1-29)-NH2 elicited a consistent but small rise in maternal hGH serum concentrations (P = 0.08), whereas hPGH concentrations remained unaltered. Finally, GRF-(1-29)-NH2 concentrations were undetectable in cord serum, but readily detectable in concomitantly obtained maternal serum. In conclusion, these data suggest that hGH secretion in the pregnant woman at term is suppressed at the pituitary level, that GRF does not affect hPGH secretion, and that fetal hGH secretion is independent of circulating maternal GRF, probably because of lack of transplacental GRF passage.

Cesarean Section↗
PubMed1989

[Direct transfer of obstetrical data by magnetic means in a randomized multicenter trial of the subjective count of fetal movements by the mother-to-be].

Ten Belgian maternity hospitals have collaborated in an international clinical multicenter trial: Multicenter Fetal Movement Trial. Nine maternity hospitals were already managing a computerized data bank before their participation in the trial. In seven of these centers the local team was able to write a program for direct transmission of data, using standard sequential ASCII files. This procedure presents many advantages: there is a gain in time and money, since it is no longer necessary to fill out data collecting forms, or coding at a central level. Transcription errors are avoided, adhesion to strict and standard definitions is guaranteed, the micro-systems are performing in a suitable fashion in each center, modifications of parameters (and corrections) are done very quickly and, automatically carried out, on the basis of clinical data as well as "research" data, transmission by telecommunication is immediately and easily feasible.

Belgium↗
PubMed1989

Severe systemic hypertension during pregnancy.

Severe hypertension during pregnancy remains an important cause of maternal mortality. Cerebral complications are frequently responsible for these deaths. Early detection of preeclampsia and preventive treatment are certainly goals for the future. In the management of severe pregnancy-induced hypertension, central issues are delivery and antihypertensive and anticonvulsive treatment. Cerebral disease consists mainly of bleeding and edema. Antihypertensive therapy can be dangerous and it is essential that hemodynamic control is provided.

Brain Diseases↗
PubMed1989

Predictive value of increased plasma levels of fibronectin in gestational hypertension.

Blood pressure, proteinuria, and plasma fibronectin and plasminogen activator inhibitor-1 levels were measured in 120 apparently healthy normotensive primigravid women during the first, second, and third trimesters of pregnancy and 2 days post partum. Thirty-two women developed hypertension (diastolic blood pressure greater than or equal to 90 mm Hg) that in 17 women was associated with proteinuria (greater than 0.3 gm/day). Fibronectin levels were 83% +/- 22% of normal (mean +/- SD) during the first trimester and 75% +/- 20% at term in the healthy women but increased from 94% +/- 36% to 187% +/- 36% in the women who developed gestational hypertension (with or without proteinuria) (p less than 0.0001). Plasminogen activator inhibitor-1 levels increased from 26 +/- 19 ng/ml to 110 +/- 86 ng/ml in healthy women and from 32 +/- 35 ng/ml to 290 +/- 90 ng/ml in hypertensive women (p less than 0.001). Increased levels of fibronectin at 25 to 36 weeks of pregnancy (greater than or equal to mean + 2 SD of the healthy women, or greater than 140%) were found in 31 of the 32 women with gestational hypertension with or without proteinuria and in 5 of the 88 healthy women (sensitivity 96%, specificity 94%). Fibronectin levels increased 3.6 +/- 1.9 weeks earlier than the onset of hypertension and/or proteinuria. Increased levels of plasminogen activator inhibitor-1 at 25 to 32 weeks (greater than or equal to 280 ng/ml) were found in 16 of the 32 women who developed gestational hypertension with or without proteinuria and in 4 of the 88 healthy women (sensitivity 50%, specificity 95%). We conclude that increased fibronectin levels are the best predictor of gestational hypertension with or without proteinuria and that its level in plasma increases several weeks before the development of hypertension.

Female↗
PubMed1989

Maternal mortality and morbidity in Belgium.

The Belgian maternal mortality rate was 8.6/100,000 births in 1984 but it is probable that underreporting occurred. Data on morbidity from one Belgian hospital are presented. Gestational hypertension occurred in 9% of the women who delivered between 1982 and 1987. Gestational diabetes was observed in 2% of the cases during the same period. Data on antepartum haemorrhage are also discussed.

Belgium↗
PubMed1988

Low-dose aspirin. I. Effect on angiotensin II pressor responses and blood prostaglandin concentrations in pregnant women sensitive to angiotensin II.

Decreased incidence of proteinuric hypertension after low-dose aspirin therapy is hypothesized to be a consequence of selective thromboxane A2 inhibition and sparing of prostacyclin. This study was designed to ascertain if low-dose aspirin therapy (81 mg/day for 1 week) alters vascular refractoriness to angiotensin II and the prostacyclin/thromboxane A2 ratio in pregnant women sensitive to angiotensin II (n = 17). Low-dose aspirin increased the effective pressor dose of angiotensin II from 5.9 +/- 2.4 to 10.2 +/- 5.5 ng/kg/min (p less than 0.01, mean +/- SD). Platelet-derived serum thromboxane B2 (a metabolite of thromboxane A2), a measure of therapy compliance, decreased from 1804 +/- 1771 to 132 +/- 206 pg/ml (p less than 0.01). Plasma thromboxane B2 decreased from 130 +/- 107 to 19 +/- 12 pg/ml (p less than 0.01). Inhibition was not selective because 6-keto-prostaglandin F1 alpha (a metabolite of prostacyclin) also decreased from 243 +/- 90 to 163 +/- 90 pg/ml (p = 0.039) and prostaglandin E2 was reduced from 155 +/- 67 to 95 +/- 40 pg/ml (p = 0.014). Decreases in thromboxane B2, however, were significantly greater (75% +/- 19%) than decreases in 6-keto-prostaglandin F1 alpha (21% +/- 33%) or prostaglandin E2 (29% +/- 36%); thus the 6-keto-prostaglandin F1 alpha/thromboxane B2 ratio increased from 3.1 +/- 2.0 to 12.4 +/- 9.9 (p less than 0.01). Although low-dose aspirin increases the effective pressor dose of angiotensin II, it does not return to normal pregnancy values. This observation is consistent with the hypothesis that this represents only a partial selective prostaglandin inhibition.

Angiotensin II↗
PubMed1987

Fibrinolytic response to venous occlusion and fibrin fragment D-dimer levels in normal and complicated pregnancy.

The fibrinolytic response to venous occlusion was assessed in 29 women with normal or complicated pregnancy, by measurements of total t-PA and free t-PA with specific ELISAs. The release of t-PA from the vessel wall was 11 +/- 9 ng/ml in non-pregnant women (mean +/- SD, n = 6) but was markedly reduced throughout pregnancy. Following venous occlusion, free t-PA increased by 12 +/- 11 ng/ml in non-pregnant women but remained below the detection limit of 2 ng/ml towards the end of pregnancy. A markedly reduced t-PA release with absence of free t-PA was also observed during late pregnancy in patients with insulin-dependent diabetes mellitus, intra-uterine growth retardation and pre-eclampsia. Plasma levels of fragment D-dimer of cross-linked fibrin were measured with a specific ELISA in 79 pregnant women. D-dimer levels were 129 +/- 36 ng/ml (mean +/- SD, n = 8) in non-pregnant women and increased to 400 +/- 170 ng/ml (n = 25) and 440 +/- 220 ng/ml (n = 22) during the second and third trimester of pregnancy respectively. Significantly higher levels than observed in uncomplicated third trimester pregnancies were found in 3 out of 6 diabetic and in 2 out of 7 pre-eclamptic women. It is concluded that the t-PA release after venous occlusion is significantly reduced during pregnancy. In addition, released t-PA is rapidly inhibited. The levels of fragment D-dimer increase during pregnancy, suggesting that, notwithstanding the marked impairment of the fibrinolytic response to venous occlusion, the fibrinolytic system remains functionally active.

Constriction↗
PubMed1987

X-linked centronuclear myopathy as a cause of floppy baby.

Two families with X-linked recessive centro-nuclear myopathy (XLR-CNM) are described. Evidence is accumulating that XLR-CNM forms a distinct entity, in contrast to the commoner later-onset forms. Family history often provides a clue to the diagnosis. Pregnancy is very often complicated by hydramnios and reduced fetal movements. We describe two families with five affected male babies who all died. An isolated case with severe fetal brady-arrhythmias in combination with acute increase in polyhydramnios is mentioned. The neonatal mortality in all recorded cases is 80 percent, with respiratory insufficiency as the cause of death. An attempt is made to establish early prenatal diagnosis and the possibility of carrier detection is briefly discussed.

Adult↗
PubMed1987

Competition, capitation, and case management: barriers to strategic reform.

Political support for competition, capitation, and case management in health services has come from successive Congresses and presidents. Benefits attributed to these organizational/financing strategies are consistent with society's preference for a private market approach. Yet, the promise has not been pursued in effective public policy or program. The systemic barriers to implementation of alternative delivery systems are examined in the context of Medicaid; they are neither trivial nor intractable.

Capitation Fee↗
PubMed1986

Thrombosis and immune disorders.

The purpose of this review has been to draw the attention of clinicians towards the possibility that some of the patients they are treating for thrombosis may have an underlying immune disturbance. This could involve functional abnormalities of the complement system (as in acquired angioneurotic oedema or in paroxysmal nocturnal haemoglobinuria), or cell-mediated immunological damage to the vessel wall (as in Behcet's syndrome or Buerger's disease), or the presence of circulating antibodies (the lupus anticoagulant or antibodies to heparin). While obviously our knowledge on most aspects is still very incomplete, the awareness of the association of thrombosis with certain immune disorders should encourage further detailed studies of mechanisms and enhance our understanding of the role of blood constituents and the vessel wall in thrombogenesis.

Angioedema↗