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Biomedical subjects

B Spitz

Publications and source records attributed to B Spitz.

72 records · Page 4Linked to original sources
PubMed1985

Influence of a vitamin E-deficient diet on prostacyclin production by mesometrial triangles and aortic rings from nondiabetic and diabetic pregnant rats.

We investigated the effect of a vitamin E-deficient diet on the synthesis of prostacyclin in nondiabetic and diabetic pregnant rats. In both groups the diet reduced fetal growth and prostacyclin production by mesometrial triangles; it also increased serum lipid peroxides, which are known to inhibit prostacyclin synthesis. Independently of the diet, mesometrial triangles of diabetic rats produced more prostacyclin than those of control rats, whereas an opposite tendency was found in the aortic rings. Our model seems useful for fundamental and pharmacologic studies of the vascular pathology of pregnancy.

Animals↗
PubMed1985

Selective culture of neurons from rat cerebral cortex: morphological characterization, glutamate uptake and related enzymes during maturation in various culture media.

Dissociated cerebral cortex of fetal rat was grown in a serum-free, chemically defined medium (CDM) (containing insulin, progesterone, estradiol, transferrin, putrescine, selenium and 15 mM KCl) and compared with cultures grown in a medium containing 20% fetal calf serum (SCM). Neurons survived well using either medium, but in the serum-free medium the cellular population was exclusively neuronal (at 96%), while glial cells began to proliferate after one week in the SCM. The various cellular morphologies are described in the present report and the presence of immunological markers characteristic of neurons was investigated. Autoradiographic experiments have been performed after incubation with various putative neurotransmitters and we have shown the presence of a strikingly high proportion of glutamatergic neurons in these cultures. Glutamate high affinity uptake was also greatly increased in neuronal cultures maintained in a CDM compared to a SCM, especially in young cultures. The development of different enzymes involved in the metabolism of glutamate was also studied; the specific activity of glutaminase increased in culture and was found to be higher in a CDM than in a SCM, while the inverse was true for glutamine synthetase. The relative proportion of both enzymes in neurons compared to glial cells was opposite, as neuronal cultures had higher levels of glutaminase and glial cultures were enriched in glutamine synthetase activity. It seems that the proportion of glutamate-neurons increases when cultured in a CDM compared to a SCM and we suggest that this culture procedure may provide a purely neuronal population enriched in mature glutamatergic neurons. It may thus be useful for future in vitro studies on glutamate and GABA metabolism in neurons.

Animals↗
PubMed1983

Prostacyclin production in whole blood throughout normal pregnancy.

In a longitudinal study of twelve normal pregnant women the base-line plasma values of 6-keto prostaglandin (PG)F1 alpha, the stable degradation product of prostacyclin, were determined. At the same time the capacity of their blood to produce prostacyclin was assessed using a stimulation test. When collagen is added to citrated whole blood there is a prompt rise in plasma 6-keto PGF1 alpha, which results from the synthesis of prostacyclin by leukocytes. These cells use cyclic endoperoxides in part coming from activated platelets and in part derived from endogenous substrate to produce prostacyclin. Both the base-line values and the capacity to produce prostacyclin fell significantly after 33 weeks of pregnancy. The decreased capacity to produce prostacyclin in the later stages of pregnancy may help account for the relatively diminished refractoriness to angiotensin II, characterizing the last two months of normal pregnancies.

Blood Platelets↗
PubMed1981

Arterial thrombosis, intrauterine death and "lupus" antiocoagulant: detection of immunoglobulin interfering with prostacyclin formation.

In a 31-year-old woman with a history of recurrent arterial thrombosis, both of whose pregnancies had resulted in intrauterine death at 23 and 24 weeks, a "lupus" anticoagulant was identified. The patient's IgG fraction, containing the lupus anticoagulant, reduced the release of prostacyclin (PGI2) from rat aorta rings or pregnant human myometrium. This inhibitory effect was abolished in the presence of arachidonic acid. The production of 6-keto-PGF1 alpha by cultured bovine endothelial cells was also decreased in the presence of the patient's IgG fraction. The plasma level of 6-keto-PGF1 alpha was reduced. An antibody in this patient may interfere with the production or release of PGI2 by the vessel wall, possibly by interfering with the availability of arachidonic acid. This mechanism could play a role in this patient's arterial disease and obstetric problems.

Adult↗
PubMed1981

"Lupus" anticoagulant and inhibition of prostacyclin formation in patients with repeated abortion, intrauterine growth retardation and intrauterine death.

We discovered a "lupus' anticoagulant in 2 out of 42 women with a history of repeated abortions, intrauterine growth retardation and intrauterine death of unknown origin. The "lupus' anticoagulant was detected by an abnormal dilute tissue thromboplastin assay(prothrombin time performed with dilute thromboplastin). The production of prostacyclin by fresh or exhausted rings of rat aorta was decreased by the plasma of one of these two patients with a "lupus' anticoagulant. In view of the increasing evidence for a physiological role of prostacyclin in pregnancy and fetal life, we suggest that an inhibition of prostacyclin production could compromise fetal outcome.

Abortion, Habitual↗
PubMed1979

When a solution is not a solution: Medicaid and Health Maintenance Organizations.

Health Maintenance Organization (HMOs) are repeatedly described as a general solution to the health care crisis and a specific solution to the problems confronting Medicare and Medicaid. The potential incorporation of HMOs into Medicaid has promised to improve the states' ability to accurately budget program expenditures, simplify management, eliminate abusive practices directly linked to fee-for-service (e.g., billing for undelivered services for providing unnecessary care) and, most important, contain costs. At the same time it has promised to increase access to mainstream medicine. Experience has shown, however, that the promise has often been severely compromised by unethical HMO marketing practices, inadequacy of services and excessive administrative costs. This article examines some of the reasons: the political process which created HMOs, the rhetorical claims which exaggerated the strengths of prepaid group practice and distorted the formulation of policy, and the peculiar characteristics of the Medicaid program which have caused Medicaid HMOs to deviate considerably from theoretical expectations.

Animals↗
PubMed1979

The politics of hospital payment.

This paper analyzes the politics of hospital payment over the last decade. The authors explain how provider interests and judgments became a standard for appropriate hospital payment: the impact of that standard on hospital costs; and the political obstacles to imposing an alternative standard and controlling hospital costs. The authors draw lessons from this experience, here and in other countries, to propose an alternative approach to hospital payment that would allow policymakers, accountable to the public, to make explicit choices about the level and nature of hospital expenditures.

Accounts Payable and Receivable↗
PubMedDate not supplied

Delivery related rupture of the gravid uterus: imaging findings.

Rupture of the gravid uterus is a rare, life-threatening obstetric complication. Major symptoms are hypovolemic shock and abdominal pain during late pregnancy or after vaginal delivery. Immediate surgical therapy is required. We report a case of uterine rupture after vaginal delivery diagnosed by means of ultrasonography and computed tomography.

Abdominal Pain↗