Comparison of estrogen priming effects with body weight restoration effects on the gonadotropin pattern of patients with anorexia nervosa

Plasma estradiol (E2), serum LH and FSH, and the gonadotropin response to two consecutive LHRH administrations (10 and 100 micrograms with an interval of 2 h) were determined in 19 patients with anorexia nervosa (AN) at the emaciation phase, before and after estradiol benzoate (E2B) injections (3 micrograms/kg/day for 7 days). The same investigations were repeated after weight restoration in 9 AN patients who remained amenorrheic. Both at the emaciation phase and after weight restoration, E2B enhanced the second LH response to LHRH and decreased serum FSH, suggesting that the functional capacities of the pituitary gonadotrophs are normal in AN. Unlike E2B injections, weight restoration increased all the hormone values, suggesting that the weight restoration effects on the abnormal gonadotropin secretory pattern of AN depend on another mechanism than the E2 lowering. That mechanism is probably a disorder of the hypothalamic LHRH secretion, the consequences of which could be reinforced by the low E2 levels.     

Sex-biased dispersal promotes adaptive parental effects

Background  

In heterogeneous environments, sex-biased dispersal could lead to environmental adaptive parental effects, with offspring selected to perform in the same way as the parent dispersing least, because this parent is more likely to be locally adapted. We investigate this hypothesis by simulating varying levels of sex-biased dispersal in a patchy environment. The relative advantage of a strategy involving pure maternal (or paternal) inheritance is then compared with a strategy involving classical biparental inheritance in plants and in animals.     

Molecular Reclassification of Crohn’s Disease: A Cautionary Note on Population Stratification

Complex human diseases commonly differ in their phenotypic characteristics, e.g., Crohn’s disease (CD) patients are heterogeneous with regard to disease location and disease extent. The genetic susceptibility to Crohn’s disease is widely acknowledged and has been demonstrated by identification of over 100 CD associated genetic loci. However, relating CD subphenotypes to disease susceptible loci has proven to be a difficult task. In this paper we discuss the use of cluster analysis on genetic markers to identify genetic-based subgroups while taking into account possible confounding by population stratification. We show that it is highly relevant to consider the confounding nature of population stratification in order to avoid that detected clusters are strongly related to population groups instead of disease-specific groups. Therefore, we explain the use of principal components to correct for population stratification while clustering affected individuals into genetic-based subgroups. The principal components are obtained using 30 ancestry informative markers (AIM), and the first two PCs are determined to discriminate between continental origins of the affected individuals. Genotypes on 51 CD associated single nucleotide polymorphisms (SNPs) are used to perform latent class analysis, hierarchical and Partitioning Around Medoids (PAM) cluster analysis within a sample of affected individuals with and without the use of principal components to adjust for population stratification. It is seen that without correction for population stratification clusters seem to be influenced by population stratification while with correction clusters are unrelated to continental origin of individuals.     

Virtual brain endocast of Antifer (Mammalia: Cervidae), an extinct large cervid from South America

A diverse fossil record of Cervidae (Mammalia) has been documented in the South American Pleistocene, when these animals arrived during the Great American Biotic Interchange. Using computed tomography-scanning techniques, it is possible to access the endocranial morphology of extinct species. Here, we studied the brain endocast of the extinct late Pleistocene cervid Antifer ensenadensis from southern Brazil, one of the largest forms that lived on this continent, using comparative morphology, geometric morphometrics, and encephalization quotients. The analyzed endocasts demonstrate that A. ensenadensis had a gyrencephalic brain, showing a prominent longitudinal sinus (=sagittal superior sinus), which is also observed in the large South American cervid Blastocerus dichotomus. The encephalization quotient is within the variation of extant cervids, suggesting maintenance of the pattern of encephalization from at least the late Pleistocene. Geometric morphometric analysis suggested a clear and linear allometric trend between brain endocast size and shape, and highlights A. ensenadensis as an extreme form within the analyzed cervids regarding brain morphology.     

Electron spin resonance of eumelanin from hair: photoinduced radicals in solid matrix

KBr matrices appear to be convenient media to reveal the radicals formed on light exposure of eumelanin dispersions. The ESR signal of eumelanin dispersed at low concentration in KBr pellets is analyzed during and after irradiation at various wavelengths. Different types of radicals are observed. R'1- and R1-types of radicals are assigned, respectively, to neutral and deprotonated intrinsic phenoxy radicals of eumelanin. R'1 can be oxidized by oxygen as opposite to R1. R2- and R'2-types are formed in the indolic site. Water favours the conversion of R2, unreactive with oxygen, into R'2 which can be oxidized. R'1 and R2 result of an electron photoejection, respectively, from the phenolic and the indolic site. The R3-type radicals are associated with the band-to-band excitation of eumelanin considered as a semiorganized solid.     

Inhibition of follicle-stimulating hormone-induced ovulation by indomethacin in the perfused rat ovary

In isolated, perfused ovaries of rats treated with pregnant mare's serum gonadotropin (PMSG), purified preparations of ovine follicle-stimulating hormone (FSH) (oFSH-211B) and rat FSH (rFSH-I-6), 100 ng/ml, were found to induce ovulations (4.8 +/- 0.9, n = 4, and 6.4 +/- 2.0, n = 5, ovulations per ovary, respectively). Indomethacin (5 micrograms/ml) added to the perfusate inhibited this ovulatory effect and exogenous prostaglandin F2 alpha (PGF2 alpha) (1 microgram/ml), or prostaglandin E2 (PGE2) (0.5 microgram/ml), reversed the blockade. Ovine FSH and rFSH had only a weak stimulatory effect on estradiol release, and only rFSH caused a significant increase in progesterone accumulation. Indomethacin reduced the stimulatory effect of rFSH on progesterone release, and this effect was reversed by PGE2 but not by PGF2 alpha. In a 6-h incubation experiment with preovulatory rat follicles, we tested the biological activity of gonadotropins used to induce oocyte maturation. The concentration of FSH used in the perfusion experiments induced oocyte maturation in more than 88% of the oocytes studied. The data confirm earlier findings that FSH can induce ovulations and show that prostaglandins are involved in this process. The data also indicate that prostaglandins might be involved in the FSH-induced increase of progesterone levels.     

Cytochalasin D inhibits basal body migration and ciliary elongation in quail oviduct epithelium

Summary The effects of cytochalasin D (CD) were studied by scanning (SEM) and transmission (TEM) electron-microscopic examination at different stages of ciliary differentiation in epithelial cells of quail oviduct. Immature quails were prestimulated by estradiol benzoate injections to induce ciliogenesis in the undifferentiated oviduct. After 24 h of CD culture, SEM study revealed inhibition of ciliogenesis and dilation of the apex of non-ciliated cells. TEM study showed that 2 h of CD treatment produced dilation of lateral intercellular spaces, after 6 h of treatment, this resulted in intracellular macrovacuolation. Vacuoles were surrounded by aggregates of dense felt-like material. CD also induced the disappearance of microvilli, and rounding of the apical surface of undifferentiated cells and those blocked in ciliogenesis. Centriologenesis was not inhibited by CD; basal bodies assembled in generative complexes in the supranuclear region after 24 h of treatment. However, the migration of mature basal bodies towards the apical surface was impaired. Instead, they anchored onto the membrane of intracellular vacuoles; growth of cilia was induced in the vacuole lumen. Cilium elongation was disturbed, giving abnormally short cilia with a dilated tip; microtubules failed to organize correctly.     

The chicken dystrophin cDNA: striking conservation of the C-terminal coding and 3'' untranslated regions between man and chicken.

Dystrophin is a very large muscle protein (approximately 400 kd) the deficiency of which is responsible for Duchenne muscular dystrophy. Its function is unknown at present. In order to know whether different domains of the protein are differentially conserved during evolution, we have cloned and sequenced the chicken dystrophin cDNA. The protein coding sequence has almost the same size as in man. The N-terminal region that resembles the actin binding domain of alpha actinin, as well as the large spectrin like domain show 80% and 75% conservation respectively between chicken and man. In contrast, the C-terminal region shows 95% identity over 627 aa suggesting that it is an important region of interaction with other proteins. Comparison of the amino acid sequence of this C-terminal region to other protein sequences shows only marginally significant similarities. Finally we have found a striking conservation of three segments of the 3' untranslated sequence (85% homology over a total of 920 nt) between chicken and man. These also appear to be conserved in other mammals. This high conservation is not linked to open reading frames.     

Low VA/Q areas: arterial-alveolar N2 difference and multiple inert gas elimination technique

In 16 critically ill patients the arterial-alveolar N2 difference and data from the multiple inert gas elimination technique (MIGET) were compared in the evaluation of the contribution of low alveolar ventilation-perfusion ratio (VA/Q) lung regions (0.005 less than VA/Q less than 0.1) to venous admixture (Qva/QT). The arterial-alveolar N2 difference was determined using a manometric technique for the measurement of the arterial N2 partial pressure (PN2). We adopted a two-compartment model of the lung, one compartment having a VA/Q of approximately 1, the other being open, gas filled, unventilated (VA/Q = 0), and in equilibrium with the mixed venous blood. This theoretical single compartment represents all lung regions responsible for the arterial-alveolar N2 difference. The fractional blood flow to this compartment was calculated using an appropriate mixing equation (Q0/QT). There was a weak but significant relationship between Q0/QT and the perfusion fraction to lung regions with low VA/Q (0.005 less than VA/Q less than 0.1) (r = 0.542, P less than 0.05) and a close relationship between Q0/QT and the perfusion fraction to lung regions with VA/Q ratios less than 0.9 (r = 0.862, P less than 0.001) as obtained from MIGET. The difference Qva/QT-Q0/QT yielded a close estimation of the MIGET right-to-left shunt (Qs/QT) (r = 0.962, P less than 0.001). We conclude that the assessment of the arterial-alveolar N2 difference and Q0/QT does not yield a quantitative estimation of the contribution of pathologically low VA/Q areas to QVa/QT because these parameters reflect an unknown combination of pathological and normal (0.1 less than VA/Q less than 0.9) gas exchange units.(ABSTRACT TRUNCATED AT 250 WORDS)