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Biomedical subjects

J Valera

Publications and source records attributed to J Valera.

6 recordsLinked to original sources
PubMed1990

Prevention of high altitude-induced testicular disturbances by previous treatment with cyproheptadine in male rats.

Male rats were exposed to 4,340 m altitude for 4 days. At this time histological alteration in the testes were observed. There were tubules with pyknotic primary spermatocytes and spermatids, necrosis of numerous cells, and sloughing of primary spermatocytes. The damaged areas were limited by normal tissue. Serum testosterone increased significantly after 4 days of exposure. Administration of an anti-serotoninergic compound, cyproheptadine (10 mg/kg body weight), prevented the high altitude-induced changes in both spermatogenesis and serum testosterone. These observations suggest that serotonin is involved in the testicular changes that occurred when rats are acutely exposed to high altitude.

Altitude Sickness↗
PubMed1984

Secular change in growth of native children and adolescents at high altitude Huancayo, Peru (3,280 meters).

Stature and weight of native children, adolescents, and adults at Huancayo , Peru (3,280 meters), were measured in 1977, 1978, and 1982 and compared with mean statures and weights reported in previous studies. The data indicate that in Huancayo there has been a secular increment in child stature, sitting height, and weight from 1937 to 1978-1982. The observed changes in stature are related to a proportionally greater increment in leg length relative to trunk length. It is concluded that the observed secular increase in body size reflects changes in the standard of living and a greater influx of nonnative populations, which are usually characterized by greater stature than natives.

Adolescent↗
PubMed1967

Studies on cholera carriers.

Cholera carrier studies in the Philippines in 1964-66 showed a prevalence rate of 21.7% among household contacts of cholera patients, and 8.4% in occupants of houses next door to one where a cholera patient lived, as opposed to 0.34% in the general population. The duration of the carrier state among 19 household carriers isolated for examination varied from 5 to 19 days. The vibrio concentration in the stool of contact carriers was 10(2)-15(5) per gram, as compared with 10(6)-19(9) per ml of rice-water stool in cholera cases.The agglutinin titre increased with time for carriers, as it does for patients. It declined to a very low level 8-12 weeks after recovery, with the exception of one proved long-term carrier.The strains isolated from carriers were identical in all respects, including virulence in infant rabbits, with strains isolated from patients-except that 3 carrier strains were rough.

Adolescent↗
PubMedDate not supplied

Beliefs, attitudes and the practice of breastfeeding among some urban parturient mothers.

Data on knowledge and beliefs on preparation for breastfeeding, feelings toward breastfeeding, and conditions considered possible or not possible for breastfeeding were obtained from 216 women admitted for delivery in a major hospital. Follow-up questionnaires were sent to them 4-5 weeks after discharge to elicit data on details of feeding. Responses received from 91 women were analyzed to determine relationships among beliefs/knowledge, feelings, conditions, and breastfeeding. Results show that knowledge was positively related to conditions considered possible for breastfeeding and to a lesser extent to feelings, while feelings and conditions were not significantly correlated. Knowledge, intention to breastfeed, husband's support, and friends' support differentiated those who breastfeed from nonbreastfeeders. Knowledge, friends' support, and husband's support were associated with length of breastfeeding. Previous experience, intention, and husband's support was found to explain 44% of the variance in breastfeeding duration.

Age Factors↗