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Biomedical subjects

V Diaz

Publications and source records attributed to V Diaz.

26 records · Page 2Linked to original sources
PubMed1988

Total creatine kinase (CK) and CK-B activity in maternal blood and cord-blood samples after vaginal and cesarean births.

We studied variations in the activity of total creatine kinase (CK; EC 2.7.3.2) and of CK-B in maternal and cord-blood samples, comparing data obtained for vaginal and cesarean births. CK-B activity was determined with an immunoinhibition assay. In all cases, there was a significant postpartum increase in total CK and in CK-B activity in maternal sera, whereas cord-blood samples showed no significant differences between activities in arterial and venous blood for either vaginal or cesarean births. Statistically significant differences were found in CK-B activity, but not in total CK, between cord-blood samples from vaginal births and those from cesareans.

Cesarean Section↗
PubMed1987

Teratogenicity of cocaine in humans.

To study teratogenicity of cocaine in humans, we studied three groups of pregnant women and their offspring: group 1, 50 women who abused cocaine only; group 2, 110 women who were polydrug abusers; and group 3, 340 who were drug free. All three groups were similar for socioeconomic status, cigarette smoking, and ethnicity. Maternal age of group 1 was similar to that of group 3, but group 2 mothers were significantly older. Gravidity was significantly higher in groups 1 and 2 compared with group 3. No statistical difference was found in spontaneous abortion rate among the three groups, but the stillbirth rate was significantly higher in group 1 (chi 2 = 6.89, P less than or equal to 0.01). All stillbirths were related to abruptio placentae. Birth weight, length, and head circumference were significantly decreased in infants in groups 1 and 2 compared with group 3 (P less than or equal to 0.0001), but no statistical difference was found between groups 1 and 2. The congenital malformation rate was significantly higher in group 1 compared with group 3 (chi 2 = 7.07, P less than or equal to 0.01). We conclude that cocaine abuse in humans significantly reduces weight of the fetus, increases the stillbirth rate related to abruptio placentae, and is associated with a higher malformation rate.

Abnormalities, Drug-Induced↗
PubMed1987

Site-finding and pairing of Echinostoma revolutum (Trematoda) on the chick chorioallantois.

Site-finding of 14-day-old Echinostoma revolutum from the domestic chick was studied by inoculating single worms into various sites on the chorioallantoic membrane (CAM) of 13-day-old chick embryos. Regardless of the site of inoculation, single worms were attracted significantly to the area of the CAM above the embryo. More worms were found in this site at 24 than at 1 hr postinoculation. Worm-pairing was studied in chick embryos by inoculating 2 worms in separate windows, 2 cm apart. Worm-pairing, i.e., worms in contact or within 5 mm of each other, was very evident at 24 hr. The percentage of paired worms on the CAM above the embryo was considerably less than single worms.

Allantois↗
PubMed1986

Influence of mebendazole on insulin secretion from isolated rat islets.

The antihelminthic drug mebendazole (MEB) has been reported to elevate circulating insulin levels in vivo. By using isolated perifused rat islets we tested the acute effects of this drug directly on the beta cell in the absence or presence of exogenous glucose. In the absence of glucose, MEB (40 micrograms/ml) caused a delayed but sustained increase in insulin output from the islet. Release induced by this concentration of MEB was not influenced by either forskolin (10 microM), a compound that increases islet cyclic AMP levels and potentiates glucose-induced secretion, or the absence of extracellular calcium. In the presence of a submaximal stimulatory glucose concentration (8 mM), release was dramatically potentiated by the further addition of 10 to 40 micrograms/ml of MEB. The potentiating effect of the drug on glucose-induced release was readily reversible and abolished by the omission of extracellular calcium or the addition of 10 mM mannoheptulose, a compound that blocks glucose phosphorylation. Despite its positive effects on hormone secretion, MEB did not affect glucose metabolism. MEB may prove useful for investigating the factors that regulate insulin secretion.

Animals↗
PubMed1984

Purification and subunit structure of RNA polymerase II from different stages of Artemia development.

RNA polymerase II has been purified from different stages of Artemia development: cryptobiotic gastrulae, developing embryos and nauplii. RNA polymerase from dormant and developing embryos consists of 12 subunits of 205 000, 140 000, 32 500, 25 600, 22 000, 19 400, 18 000, 16 800, 147 000, 14 000, 12 700 and 11 500 daltons, as determined by dodecyl sulphate polyacrylamide gel electrophoresis. The enzyme from larvae contains the same polypeptides except for the higher-molecular-mass component: the larval enzyme has a subunit of 172 kDa instead of the 205-kDa subunit present in the enzyme purified from embryos. Incubation of embryonic RNA polymerase II with larval extracts results in the conversion of the 205-kDa subunit into the 172-kDa one. This conversion is inhibited by soybean trypsin inhibitor, a compound which inhibits three proteases induced during Artemia early larval development. RNA polymerase II purified from a mixture of embryos and larvae contain only the 172-kDa subunit. Our results indicate that the 172-kDa subunit present in RNA polymerase II purified from larvae is produced by proteolysis of the 205-kDa subunit during the extraction and purification of the enzyme and therefore that Artemia has only one class of RNA polymerase II.

Animals↗
PubMed1980

Plasma levels and urinary excretion of orally administered propantheline bromide in man.

After a single oral dose of 30 or 60 mg of propantheline bromide peak plasma levels of the drug were reached within 2 h in six healthy men. Mean peak plasma concentrations were 20.6 and 53.1 ng/ml after 30 mg and 60 mg respectively. The mean apparent absorption and elimination half-lives after 30 mg dose were 0.22 and 1.57 h respectively, and similar half-lives were found at the higher dose level. There was a dose related change in plasma levels and AUCinfinity of the drug, and some 3% to 4% of the administered dose of propantheline bromide was excreted unchanged in urine at each dose level. Comparison of the plasma levels and urinary excretion of the drug with those seen after i.v. administration in an earlier study indicated an apparently low systemic availability of orally administered propantheline bromide. There was tentative evidence of a qualitative relationship between the oral dose administered, plasma concentrations and the effects of propantheline bromide on salivary excretion.

Administration, Oral↗