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Biomedical subjects

A Quintana

Publications and source records attributed to A Quintana.

35 records · Page 2Linked to original sources
PubMed1990

[Intrahepatic cholestasis in pregnancy and perinatal risk].

The main purpose of this study was to analyze the accuracy of severity criteria applied in cholestatic jaundice in pregnancy related to health problems in the newborn. The sample, 209 cases, is formed by the total of hospital patients discharges from the Pathologic Pregnancy Unit. Severe cholestatic jaundice (59.3% of cases) presented early itching and impeding premature delivery as the most frequent severity criteria. We found that the greater number of severity criteria, the worse prognosis for the newborn, as shown by birth weight under 2,500 g and Apgar at the minute of 7 or less. Both differences were statistically significant (p = 0.0001; p = 0.0348). No maternal or perinatal deaths were found. Our conclusions are: 1. Severity criteria used in cholestatic jaundice of pregnancy are valied and 2. Clinical management of cases is appropriate, since the major risk reported (perinatal mortality) was absent and maternal and perinatal morbidity were less than those reported in previous studies.

Birth Weight↗
PubMed1988

Effects of indomethacin and diclofenac on cerebral blood flow in hypercapnic conscious rats.

Cerebral blood flow (CBF) was measured in conscious rats treated with indomethacin, diclofenac or the vehicle for indomethacin during hypercapnia of three different degrees. Similar values were found for CBF in rats treated with diclofenac or vehicle and there was a direct correlation between CBF and the arterial blood carbon dioxide values. In contrast, indomethacin completely blocked the increase of CBF during hypercapnia. These results suggest strongly that prostaglandins are not involved in the hypercapnia-induced cerebral vasodilatation.

Animals↗
PubMed1983

Effects of aspirin and indomethacin on cerebral circulation in the conscious rat: evidence for a physiological role of endogenous prostaglandins.

The purpose of this work was to evaluate the effects of equipotent doses of two different inhibitors of cyclo-oxygenase, indomethacin and aspirin, on cerebral blood flow and cerebral vascular resistances in the conscious undisturbed rat, using the reference sample radioactive microsphere method. We found that both, aspirin (50 mg/kg) and indomethacin (5 mg/kg) at 3, 15 and 60 min after their intravenous administration, increased cerebral vascular resistances and decreased cerebral blood flow to a similar extent. Both drugs completely abolished the hypotensive effect of 5 mg/kg i.v. arachidonic acid and they did not change arterial PO2, PCO2 or pH values. We conclude that the pharmacological inhibition of cyclooxygenase in the conscious undisturbed rat leads to a cerebral vasoconstriction and consequently to a decrease in cerebral blood flow. Our results evidence that prostaglandins are a physiological factor that actively contributes to the maintenance of cerebral circulation.

Animals↗
PubMed1983

Distribution of cardiac output during development of two metastasizing murine tumors.

The study of cardiac output (CO) distribution to tumors and metastases is of interest for a better understanding of tumor biology and for pharmacological approaches. A radioactive microsphere method was developed to asses CO distribution in C57BL/6J mice bearing syngeneic 3LL or BALB/c mice with JWS. At the initial stages of cancer growth, the CO relative fractions per g of tissue (%CO/g) to 3LL and JWS were similar to those in surrounding tissues. In both tumors a positive, significant correlation was found between tumor weight and tumor CO fraction, but %CO/g was lower in 3LL 2 and 3 weeks after transplantation, whereas it did not change in JWS. Indeed, much larger necrotic areas developed in 3LL than in JWS. The %CO/g to the lungs increased in both models when metastases were not yet visible; subsequently, the appearance of lung nodules was accompanied by a decrease of %CO/g in JWS and a further increase in 3LL. This corresponded to the much higher ratio of metastatic to intact lung tissue in JWS than in 3LL. In fact, isolated lung metastases had a significantly lower blood supply than the surrounding tissue. This might be due to a different vascularization pattern and/or smaller amounts of vasodilator substances being produced by metastatic nodules; the latter is suggested by lower generation of prostacyclin activity in isolated lung metastases than in intact pulmonary tissue.

Animals↗
PubMed1983

Cardiac output redistribution induced by noradrenaline in two murine tumor models.

The response of tumor vessels to vasoactive substances could provide useful information on experimental tumor biology. We have studied the effects of noradrenaline (20 micrograms/kg i.v.) on cardiac output (%CO) distribution in C57BL/6J mice bearing syngeneic Lewis lung carcinoma (3LL) and BALB/c mice with JW sarcoma (JWS). Mice were studied at different stages during tumor growth using microspheres labeled with 57Co (basal determination) or 58Co (after noradrenaline or saline). In control C57BL/6J mice noradrenaline induced a redistribution of CO, with an increase in the heart and brain and a decrease in the kidneys and hind limb muscle CO fractions (%CO). In 3LL-bearing mice the %CO to the tumor was not changed by noradrenaline 1 week after implantation but was significantly less after 2 and 3 weeks. %CO to the total lung tissue or to isolated metastases did not change after noradrenaline. In control BALB/c mice noradrenaline increased the %CO to the brain and decreased that to the kidneys and hind limb muscle. In JWS-bearing mice the %CO to the tumor was reduced 2 weeks after implantation, was not changed after 4 weeks and was increased after 6 weeks. These results suggest that tumor vessel reactivity to a vasoactive substance may change markedly during various phases of tumor growth and may differ in different experimental models.

Animals↗
PubMed1978

Effects of pimozide on the response of smooth muscle to non-dopamine agonists and calcium.

Pimozide inhibits acetylcholine and histamine-induced contractions of the isolated guinea-pig ileum and noradrenaline-induced contractions of the isolated rat vas deferens in a non-competitive manner. In order to explore the nature of this inhibitory effect, we investigated pimozide's effects on calcium-induced contractions of deplorized guinea-pig ileum. In this case the antagonism elicited was competitive. Therefore caution is indicated in the use of pimozide to provide indirect proof of the existence of peripheral dopamine receptors.

Acetylcholine↗
PubMed1978

Significance of a new isovolumetric technique for the study of the myometrial dynamics in vitro.

Above usual values for active tension are measured in 10 uterine horns of rat under electric stimulation through an original isovolumetric technique. At the maximum length increase attained were 1.79 +/- 0.2 kg/cm2, with passive tension from 9--10% total tension. These values are within the range for other smooth and striated muscles. The isometric techniques efficacy to record total uterine tension, as well as the application of isometric activity to the analyse of uterine dynamics are discussed.

Animals↗
PubMed1977

Effect of pancuronium bromide on the adrenergic reactivity of the isolated rat vas deferens.

Pancuronium bromide (10(-7) to 10(-4) M) failed to produce contraction of the isolated rat vas deferens. Also, no contractions were seen when the animals were pretreated with an MAO inhibitor (iproniazid 80 mg/kg, p.o.). On the other hand, pancuronium bromide (10(-6) to 10(-4) M) produced 1.62- to 2.65-fold increases in the sensitivity of the vas deferens to noradrenaline. This rules out an indirect adrenergic effect in this preparation and suggests an inhibitory effect on catecholamine uptake.

Animals↗
PubMed1975

Cytogenetics of fetal wastage.

A consecutive series of 50 couples with a histroy of fetal wastage were studied cytogenetically with current banding technics. Fetal wastage was defined as occurring in couples who had more than two early abortions, stillbirth(s) or livebirths(s) or both of infants with multiple congenital anomalies. Three women were found to be balanced reciprocal translocation carriers; all translocations were not detectable by the conventional method but were demonstrable by current banding technics. In addition to the translocation carriers, one woman was found to be a mosaic for 45,X/46,XX/47,XXX. Four of the parents showed increased mitotic instability or chromosome breakage and rearrangement, or both. Parental chromosome abnormalities may therefore account for fetal wastage in between 6 and 16 per cent (or about one in 10) of couples having such a history. Such couples, if identified, can potentially benefit by prenatal monitoring of future pregnancies.

Abnormalities, Multiple↗