Study of Two-Photon Exchange via the Beam Transverse Single Spin Asymmetry in Electron-Proton Elastic Scattering at Forward Angles over a Wide Energy Range.

We report on a new measurement of the beam transverse single spin asymmetry in electron-proton elastic scattering, A_{⊥}^{ep}, at five beam energies from 315.1 to 1508.4 MeV and at a scattering angle of 30°<θ<40°. The covered Q^{2} values are 0.032, 0.057, 0.082, 0.218, 0.613 (GeV/c)^{2}. The measurement clearly indicates significant inelastic contributions to the two-photon-exchange (TPE) amplitude in the low-Q^{2} kinematic region. No theoretical calculation is able to reproduce our result. Comparison with a calculation based on unitarity, which only takes into account elastic and πN inelastic intermediate states, suggests that there are other inelastic intermediate states such as ππN, KΛ, and ηN. Covering a wide energy range, our new high-precision data provide a benchmark to study those intermediate states.

[High incidence of hyperestrogenemia and dyslipidemia in a group of infertile men]. / Elevada incidencia de hiperestrogenemia y de dislipidemia en un grupo de hombres infértiles.

The aim of this paper is to describe metabolic and endocrine alterations in the male, partners of infertile couples. One hundred and six consecutive men were taken in order to analyze their serum samples. Each serum sample was analyzed by duplicate for luteinizing hormone (LH), follicle-stimulating hormone (FSH), estradiol (E2), free-testosterone (T), 17 alpha-hydroxyprogesterone (17OHP), androstenedione (A), dehydroepiandrosterone-sulphate (DHEA-S), prolactin (PRL), insulin, glucose, total cholesterol and triclylcerides. The data analysis evidenced different metabolic or endocrine alterations in the group. A dysplipidemia incidence of 65% was found (isolated hypercholesterolemia, isolated triglyceridemia or both), where 80% of these patients were younger than 40 years. There was no correlation with obesity, overweight any endocrine alteration and the type of sperm alterations. There was a positive correlation between E2 and FSH (r = 0.67, p < 0.0001) in the group of 106 patients, which remained significant in the group of hyperestrogenic men (n = 27, r = 0.68, p < 0.0001), but not in men with normal serum estrogen levels (n = 79, r = 0.10, NS). Other alterations: obesity in 18%, overweight in 30.2%, diabetes mellitus 4.7%, glucose intolerance 15%, hypertension 26% (14/53), hypergonadotropic hypogonadism 3.8% (one of them with an Emty Sella syndrome). Unexpectedly only nine patients (8.4%) out of the 106 consecutive patients recluted did not have any of the metabolic or endodrine abnormalities here described. These are more significant since 83% of the patients are younger than 40 years. The most interesting non previously described finding was the positive correlation observed between E2 and FSH when estradiol levels exceeds 50 pg/mL.

[Obstetric decisions concerning adolescents vs. adults]. / La resolución obstétrica de las adolescentes en comparación con la de las adultas.

Information relative to the frequency of vaginal delivery and cesarean section in adolescent population is limited and contradictory. Some publications refer that cesarean section is practiced more frequently in adolescents than in adults, because teenagers have a biological immaturity and a less medical control during pregnancy; but others show that frequency of cesarean section and vaginal delivery is very similar in adolescents as in adults. The reason of this contradiction is the fact that all studies compare general populations, with or without sistemic pathologies, and with or without obstetric antecedents. Therefore, the authors of this paper consider that if they compare adolescent and adult populations in their first pregnancy and without sistemic pathologies, the frequency of cesarean section and vaginal delivery should be the same in the two groups of women. To confirm their hypothesis, the authors collected original data from 121 adolescent women in their first pregnancy, seventeen years old or younger, without sistemic pathology, attended in the Instituto Nacional de Perinatología, and they compared them with original data collected from 121 adult women also in their first pregnancy, between 20 to 27 years old, without sistemic pathology, attended in the same institution and during the same period. The authors concluded that there were not statistical differences between the two groups in relation to the number of prenatal care visits; the weeks of pregnancy at the time of delivery; the indications of the different obstetric procedures to resolve the delivery; and in the perinatal mortality. Nevertheless, there were differences with high statistical significance between the number of vaginal deliveries and the number of cesarean sections; in fact, the cesarean section was performed more frequently in adult women. The authors considered that in the population of adolescents they studied, the age by itself was not a risk factor; furthermore, it is necessary to perform other studies to confirm and to explain why the cesarean section was performed more frequently in the adult population.

The after breakfast 50-g, 1-hour glucose challenge test in urban Mexican pregnant women: its sensitivity and specificity evaluated by three diagnostic criteria for gestational diabetes mellitus.

BACKGROUND: To study the sensitivity and specificity of the 50-g, 1-hour gestational glucose challenge test performed 1 to 2 hours after a non-standardized home breakfast in urban Mexican women by using three different gestational diabetes mellitus diagnostic criteria. METHODS: Four hundred and forty-five consecutive women of 24-28 weeks gestation were studied. The glucose challenge test was performed in the fed state and a week later a fasting 100-g, 3-hours oral glucose tolerance test was carried out in all of them. Duplicate serum glucose concentrations were determined by a glucose-oxidase method. Sensitivity and specificity were calculated using three different diagnostic criteria for gestational diabetes mellitus. RESULTS: The glucose challenge test performed as indicated, with a cutoff of 7.8 mmol/L, had 88-89% sensitivity and 85-87% specificity when using as diagnostic criteria those proposed by the National Diabetes Data Group and by Carpenter & Coustan; by using Sacks et al. criteria, the values were 82% and 88%, respectively. Considering only pregnant women > or = 25 years of age, the sensitivity increased to 92% with the National Diabetes Data Group criteria. Pregnant women < 25 years of age had significantly lower blood glucose values than those with age > or = 25 years during the glucose tolerance test. CONCLUSIONS: For the general group the sensitivity of the glucose challenge test performed 1 to 2 hours after breakfast was similar, based on the National Diabetes Data Group and the Carpenter & Coustan's diagnostic criteria for gestational diabetes mellitus. However, when pregnant women > or = 25 years of age were considered, the use of the former criteria yielded a slightly better sensitivity.

Effect of quality of care on preventable perinatal mortality.

This study assessed and quantified the effect of quality of care on death preventability, independent of social and biological variables. One hundred and eighty-one avoidable perinatal deaths (cases) were compared to 341 non-avoidable ones (controls). Judgement criteria on death preventability were based predominantly on compliance with explicit hospital medical care standards, determined by peer review. The overall perinatal mortality rate was 24.8 per 1000 births and could be reduced by 35% if all avoidable perinatal deaths were prevented. Sixteen per cent of the deaths presented structural and 31.2% process deficiencies; both predominated among avoidable perinatal deaths (35.4% vs 5.3%, p < 0.000; and 79.3% vs 5.9%, p < 0.000, respectively). Structural deficiencies increased the risk of an avoidable perinatal death eleven-fold (95% confidence interval (CI) 4.1, 26.9; p < 0.001) and process deficiencies eighty-eightfold (95% CI 37.2, 204.5, p < 0.001), after controlling for confounders. The strength of the association between quality of care and preventable perinatal mortality was estimated.

Factors in the pathogenesis of acute schistosomiasis mansoni.

Acute schistosomiasis mansoni was studied in 26 Puerto Rican patients whose clinical presentations differed widely in severity. Severity of illness was found to be positively correlated (r = 0.79) with the intensity of infection as measured by the concentration of eggs of Schistosoma mansoni in stool specimens. However, some patients had severe illness but relatively light infections. The disappearnace of symptoms and return toward normal of laboratory measures of disease activity were not associated with any diminution in the fecal egg count. Elevations of IgG, IgM, IgE, and of titers of anibody in serum indicated that the illness is associated with intense immune activity. The magnitude of the IgG and IgE responses was related to intensity of infection. The fact that incubation periods were shorter than the time needed for schistosomes to reach adulthood and lay eggs suggests that the syndrome can be initiated by parasite stages present before oviposition. No marked changes in complement (C3, C3p, C4, and CH50) and no signs of renal disease were noted in any of these patients.