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Biomedical subjects

J Diaz

Publications and source records attributed to J Diaz.

At least 217 records · Page 12Linked to original sources
PubMed1982

Association of marital status and years of schooling with perinatal outcome: the influence of pre-natal care as an intermediate variable.

The association between mother's education and perinatal mortality, and between marital status and proportion of preterm deliveries was analyzed using data from 20,000 women and newborns delivered at the Hospital Barros Luco-Trudeau in Santiago, Chile. A highly significant correlation was found, but after being controlled by pre-natal care, that association disappeared for those mothers with good pre-natal care, remaining only as a part of the association for women who did not attend the pre-natal clinics or did not follow minimal standards of care. The definition used for "good pre-natal care" was much less demanding than WHO recommendation. We required a minimum of only 5 visits, starting before the 5th month of the pregnancy and with blood pressure and body weight registered at each visit. Pre-natal assistance was provided mostly by registered midwives, with occasional consultation by physicians. The efficiency of a low cost health activity, such as pre-natal care, in improving infant health is held in contrast with the inefficiency of high cost technology when applied to developing countries' health problems.

Chile↗
PubMed1982

Electronically excited species in the spontaneous chemiluminescence of urine and its uses in the detection of pathological conditions.

A relatively simple procedure for the measurement of urinary chemiluminescence is described and some of the variables affecting such measurements are examined. Normal urinary chemiluminescence is due to lipoperoxidation, presumably through the Haber-Weiss reaction, generating singlet oxygen as emitter. It was found that urinary chemiluminescence was higher in normal smokers than in normal non-smokers and very low in cancer patients. Oral distribution of ascorbic acid reduced urinary chemiluminescence of both normal smokers and non-smokers. Presumably, the spontaneous chemiluminescence in the urine could serve as a cancer marker.

Clinical Laboratory Techniques↗
PubMed1981

Intrauterine contraception with levonorgestrel: a comparative randomised clinical performance study.

Two levonorgestrel-releasing intrauterine devices (IUD) with different release rates of levonorgestrel and a 'Nova-T' copper-releasing device were compared in a randomised clinical performance study. 327 women had a levonorgestrel IUD and 156 women a nova-T device inserted postmenstrually. No statistically significant differences in the reasons for termination between the three devices were found in 12 months. The continuation rates for the two levonorgestrel IUDs were 84.1 and 81.4 and for the nova-T device 87.5. Duration of menstrual bleeding and spotting was highly significantly shorter with the levonorgestrel IUDs than with the nova-T device. There were no infections.

Adolescent↗
PubMed1981

Effects of dipropylacetate on brain development.

Dipropylacetate (DPA: valproic acid) is a new anticonvulsant reported to be effective in many types of seizures including those that occur early in life. This study describes the effects of chronic administration of DPA upon a developing organism. Four-day-old rat pups were injected daily with either 75 mg/kg DPA, 200 mg/kg DPA, or vehicle until day 18. Administration of DPA resulted in decreased body and organ weights, with the greatest reductions in the 200 mg/kg group. To control caloric intake, and additional experiment was conducted. Animals were injected with either vehicle or 200 mg/kg DPA. Each animal was implanted with a chronic intragastric cannula and fed through the cannula. The results of this experiment indicated that body and organ weights were the same for both vehicle and drug groups, except for brain. The animals receiving DPA had significant deficits of 12% in total brain weight and 22% in weight of the cerebellum. The data suggest that chronic administration of DPA early in life may have adverse consequences on brain growth.

Animals↗
PubMed1981

A multicenter study of levonorgestrel-estradiol contraceptive vaginal rings. II-Subjective and objective measures of effects. An international comparative trial.

Comparative clinical trials of 2 sizes of contraceptive vaginal rings and of an oral contraceptive were undertaken at 8 investigational sites (9 clinics). More than 500 women enrolled on each of the 3 study regimens. Side effects of the rings and of Nordette, the oral contraceptive, were evaluated by noting spontaneous complaints, by recording medications taken and by physical examination. Inquiries about changes in the frequency of specific conditions were made at the end of the subjects participation in the first year of the study. The incidence of spontaneous complaints was similar among users of the 2 different-sized rings and of the pill.

Adolescent↗
PubMed1981

A multicenter study of levonorgestrel-estradiol contraceptive vaginal rings. III-Menstrual patterns. An international comparative trial.

Menstrual events among users of contraceptive vaginal rings (CVRs), releasing levonorgestrel and estradiol, were studied in comparison with a combined oral contraceptive, Nordette, in multicentered trials. CVRs were made with outside diameters of 50 and 58 mm and released about 250 micrograms and 290 microgram of levonorgestrel and 150 microgram and 180 microgram of estradiol per day, respectively. The CVRs were used continuously for 3 weeks and then removed for 1 week. Both the CVRs and Nordette were perceived to reduce menstrual flow and days of menstrual bleeding. Twenty to 25% of CVR users perceived increased intermenstrual bleeding or spotting. Diaries indicate, however, that on average, CVR users experienced about 1 day per month of bleeding or spotting with the ring in place. CVRs and Nordette produced approximately the same total number of bleeding and spotting days during 6 cycles of use, 27-29, but the small (50-mm OD) ring was associated with somewhat more spotting. This ring was also associated with somewhat more prolonged bleeding and spotting runs and with more prolonged nonbleeding intervals than reported by users of the larger (58-mm OD) ring or of Nordette. Differences among regimens, however, tended to be small even when statistically significant. Evidence from menstrual diaries indicates that these CVRs, and in particular 58-mm ring, provide control over the menstrual cycle comparable to the Nordette.

Adolescent↗
PubMed1981

Altered development of brain by neonatal ethanol exposure: zinc levels during and after exposure.

Neonatal rats, exposed to ethanol by use of an artificial rearing technique during the first postnatal week, have been shown to have a 20% reduction in brain weight compared to littermate controls. The mechanisms responsible for this deficit remain to be determined. One hypothesis, which has been suggested that could be responsible for the microcephaly observed in the Fetal Alcohol Syndrome is that human alcoholics have decreased serum zinc levels. It is well documented that zinc deficiency in rats results in microcephaly. Thus, ethanol administered in the diet could result in lowered zinc levels in serum and brain, and hence be the underlying factor for the brain growth deficiency reported. In these studies, serum and brain zinc levels were determined for animals exposed to ethanol using the artificial rearing procedure, and for their littermate controls, artificially reared on the same formula without ethanol. No differences at any time were found in either serum or brain zinc levels. This would suggest that zinc availability could not account for the effects found on brain growth.

Animals↗
PubMed1980

Impaired brain growth in neonatal rats exposed to ethanol.

Infant rat pups, fed through intragastric cannulas from postnatal day 4 through day 18, showed a 19 percent reduction in total brain weight when ethanol was included in their diet on days 4 through 7. This reduction in brain weight occurred even though body growth in the experimental rats was equal to that of their littermate controls. The ethanol-exposed animals were markedly hypoactive during the period of drug administration, then displayed gross body tremors for 3 to 5 days. Throughout the study, the animals treated with ethanol had poor motor coordination and were hyperresponsive. These brain and behavioral effects appear similar to those seen in fetal alcohol syndrome.

Age Factors↗
PubMed1978

Stages of recovery from central norepinephrine lesions in enriched and impoverished environments: a behavioral and biochemical study.

Adult rats were injected intraventricularly with 6-OHDA and allowed to recover for varying time periods in either an enriched colony environment or in isolation cages. When tested behaviorally in a novel environment, isolated animals showed a cyclical recovery pattern, with behavioral changes at 14 days after lesioning which were different from those seen at 2 and 45 days after lesioning. In contrast, animals housed in a colony environment showed progressive improvement and better recovery than isolates. Biochemical studies of uptake of H3NE and histofluorescence indicated that colony housed animals had enrichment effects (higher cortical NE uptake), but they were also more susceptible to 6-OHDA and did not recover well from the lesions. Isolated animals showed somewhat better recovery of NE uptake following 6-OHDA injections, especially in cortex. Because behavioral recovery from 6-OHDA was dissociated from biochemical indicators of recovery in NE circuitry, these results imply that brain systems other than NE were primarily responsible for the enhanced behavioral recovery which occurs in enriched environments.

Animals↗
PubMed1978

Clinical trial with subdermal implants containing norgestrienone.

Norgestrienone implants delivering approximately 225 microgram/ day were tested clinically for contraceptive effectiveness and acceptability in 145 women. Five pregnancies occurred in 2259 woman-months of use, one in the 11th month, one in the 15th and three in the 16th month of use. Continuation rate at 12 months was 86.7. The number of bleeding runs and bleeding days was increased in approximately 12% of the subjects. Ten percent of the patients had no bleeding in the first 90 days of treatment. Changes in bleeding pattern led to closures in four cases. Headache and signs of mild androgenicity were among the leading side effects. Blood and urine analysis throughout the study showed normal values of 17 different parameters, but a tendency to lower cholesterolemia not associated with changes in thyroid hormone levels, was observed in several patients. Cortisol was found slightly under the lower normal range in one subject without clinical manifestations of hypoadrenalism. It is concluded that norgestrienone implants should be replaced every twelve months for maximal contraceptive effect and because of their efficacy and good acceptability, evaluation of their long term use is warranted.

Adolescent↗
PubMed1977

Phenobarbital-induced brain growth retardation in artificially reared rat pups.

Phenobarbital was administered daily to rat pups during the period of their brain growth spurt. A new technique for artificially rearing rat pups, using chronic intragastric feeding cannulas, was used to prevent drug-induced undernutrition. Rats, receiving neonatal phenobarbital, experienced a marked interruption of early brain growth, although their body weights reflected normal growth.

Animals↗