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Biomedical subjects

L Peralta

Publications and source records attributed to L Peralta.

25 records · Page 2Linked to original sources
PubMed1999

Cervical ectopy and the transformation zone measured by computerized planimetry in adolescents.

OBJECTIVE: To determine whether cervical ectopy and the transformation (T) zone were larger in adolescents using oral contraceptives (OCs) compared to depot medroxyprogesterone acetate (DMPA). METHOD: Cervical photographs were taken on 91 adolescents in Baltimore, Maryland. Ectopy and T zone size were measured using computerized planimetry. Patients provided reproductive and sexual history. Correlates of ectopy and T zone size were identified by proportional odds and linear regression models, respectively. RESULT: Twenty-five women had no ectopy. Parity was independently associated with greater ectopy (OR 3.9, 95% CI 1.37-11.11). Predictors of smaller ectopy were douching (OR 0.23, 95% CI 0.09-0.65), and shorter sexual history (OR 0.20, 95% CI 0.05-0.74). Neither OC or DMPA were associated with ectopy. Predictors of greater T zone size were years since menarche (13.8 mm2/year, P = 0.003) and OCs (54.7 mm2, P = 0.05). DMPA predicted a smaller T zone (-67.0 mm2, P = 0.01). CONCLUSION: Computerized planimetry provides standardized measurements. Douching and sexual activity may decrease ectopy through increased squamous metaplasia. Hormonal contraceptives were not associated with ectopy in adolescents. However, long-term progestin use may decrease T zone size.

Adolescent↗
PubMed1998

Phosphorylation of endogenous and TEST-yolk buffer proteins by intact human sperm.

Protein kinase activity of intact, motile sperm was assessed by measuring the transfer of the terminal phosphate from [32P]ATP to tricholoroacetic acid (TCA)-precipitable casein. The action of TEST (TES and Tris) yolk buffer (TYB) treatment on phosphorylation of sperm and TYB proteins was studied by detecting labelled phosphoproteins by autoradiography of polyacrylamide gel electrophoresis (PAGE). Results demonstrate that intact, forward-motile sperm have cell surface protein kinase activities. Although the difference between the kinase activity of freshly ejaculated sperm incubated in TYB was not significant, the protein phosphorylation during incubation in TYB showed that: (i) specific sperm surface proteins were phosphorylated to different degrees during the course of treatment; (ii) TYB proteins were phosphorylated by sperm during incubation; (iii) solubilised [32P]-labelled surface proteins were similar in molecular weight to TYB-labelled proteins. Taking into account that specific proteins on the human sperm surface undergo phosphorylation during incubation in TYB and that the sperm enzyme also acts specifically on some TYB proteins that become attached to the surface of the sperm, working hypotheses are proposed that suggest some correlation between the preservation of semen in TYB and the phosphorylation of proteins by intact human sperm.

Adenosine Triphosphate↗
PubMed1994

Chronic paroxysmal hemicrania in a child.

Chronic paroxysmal hemicrania (CPH) is a relatively new condition first described in 1973. Since its first description, over 80 cases have been reported worldwide. Very few cases have been reported in children. We report the presentation of an 8-year-old boy to illustrate the problems in diagnosis and treatment of this rare disease in childhood.

Adult↗
PubMed1993

Diagnoses and symptom patterns in children presenting to a pediatric headache clinic.

The diagnosis of migraine headache in children and adolescents is complex and not well understood. This study was conducted to compare diagnostic rates, using various criteria for pediatric migraine, and specific symptom characteristics in a sample of children referred for care to a specialized pediatric headache clinic. A structured interview was used at the patient's initial assessment visit to elicit symptom patterns and therapies attempted for headache. Clinical diagnoses were based on consensus agreement reached by a multidisciplinary team. Statistically derived diagnostic rates based on International Headache Society (IHS), Prensky, Vahlquist and our own criteria were significantly lower than clinical diagnostic rates. IHS diagnostic rates were differentially distributed as a function of race, but no other effects were found for demographic variables on diagnostic rates. Specific symptom patterns, however, varied as a function of race, gender and age of the child. The results underscore the need for comprehensive, developmentally based models of the evolution of migraine headache as a foundation for future research and the further development of clinically sensitive diagnostic criteria for pediatric migraine.

Adolescent↗