Maternal obesity is associated with a reduction in placental taurine transporter activity.

BACKGROUND/OBJECTIVES: Maternal obesity increases the risk of poor pregnancy outcome including stillbirth, pre-eclampsia, fetal growth restriction and fetal overgrowth. These pregnancy complications are associated with dysfunctional syncytiotrophoblast, the transporting epithelium of the human placenta. Taurine, a ß-amino acid with antioxidant and cytoprotective properties, has a role in syncytiotrophoblast development and function and is required for fetal growth and organ development. Taurine is conditionally essential in pregnancy and fetal tissues depend on uptake of taurine from maternal blood. We tested the hypothesis that taurine uptake into placental syncytiotrophoblast by the taurine transporter protein (TauT) is lower in obese women (body mass index (BMI)⩾30 kg m(-)(2)) than in women of ideal weight (BMI 18.5-24.9 kg m(-)(2)) and explored potential regulatory factors. SUBJECTS/METHODS: Placentas were collected from term (37-42-week gestation), uncomplicated, singleton pregnancies from women with BMI 19-49 kg m(-)(2). TauT activity was measured as the Na(+)-dependent uptake of (3)H-taurine into placental villous fragments. TauT expression in membrane-enriched placental samples was investigated by western blot. In vitro studies using placental villous explants examined whether leptin or IL-6, adipokines/cytokines that are elevated in maternal obesity, regulates TauT activity. RESULTS: Placental TauT activity was significantly lower in obese women (BMI⩾30) than women of ideal weight (P<0.03) and inversely related to maternal BMI (19-49 kg m(-)(2); P<0.05; n=61). There was no difference in TauT expression between placentas of ideal weight and obese class III (BMI⩾40) subjects. Long-term exposure (48 h) of placental villous explants to leptin or IL-6 did not affect TauT activity. CONCLUSIONS: Placental TauT activity at term is negatively related to maternal BMI. We propose that the reduction in placental TauT activity in maternal obesity could lower syncytiotrophoblast taurine concentration, compromise placental development and function, and reduce the driving force for taurine efflux to the fetus, thereby increasing the risk of poor pregnancy outcome.

Bat community species richness and composition in a restinga protected area in Southeastern Brazil.

In Brazil, restingas are under severe human-induced impacts resulting in habitat degradation and loss and remain one of the less frequently studied ecosystems. The main objectives of the present study are to describe the bat community in a restinga in Paulo Cesar Vinha State Park, Guarapari municipality, state of Espírito Santo, southeastern Brazil. Fieldwork was conducted twice a month from August 2004 to September 2005. A total sampling effort of 40,300 m(2)/h, represents the largest sampling effort for sampling bats in restingas to date. Bats were sampled in five different vegetational types in the area. Captured bats were processed recording information on species, sex, age, forearm length and weight. Shannon Diversity and Jaccard indexes were used to analyse diversity and similarity among habitats in the Park. A total of 554 captures belonging to 14 species and two families were obtained. Noctilio leporinus was recorded through direct observation and an ultra-sound detector also registered the presence of individuals from the family Molossidae, without being possible to distinguish it at specific level. Frugivores were the most representative guild. Richness was higher in Clusia shrubs (11 species) and Caraís lagoon (10 species). Shannon diversity index was estimated at H' = 1.43 for the overall sample, with Caraís lagoon representing the most diverse habitat (H' = 1.60). The greater similarity (J = 0.714) was observed for the two areas under high human influence.

Extrapontine myelinolysis presenting as acute parkinsonism.

BACKGROUND: Extrapontine myelinolysis presenting with extra pyramidal features suggestive of parkinsonism may be a challenging clinical syndrome. Clinicians should maintain their vigilance while correcting electrolyte imbalances, especially with associated co-morbidity. CASE PRESENTATION: A 41-year-old woman presented with acute parkinsonism like features while on a holiday. This followed slow correction of hyponatraemia after repeated vomiting. MRI changes were suggestive of Extrapontine myelinolysis(EPM). This case is at variance with four previous cases reported in the medical literature in that the patient made a full clinical recovery and the MR changes resolved with symptomatic support alone. CONCLUSION: Extrapontine myelinolysis could make a complete recovery with symptomatic support alone. During hyponatraemia correction, rapid osmotic shifts of fluid that cause hypernatremia, causes myelinolysis rather than absolute serum sodium level. Even gradual correction of hyponatraemia can produce myelinolysis, especially with pre-existing malnourishment, alcoholism, drug misuse, Addison's disease and immuno-suppression. Pallidial sparing is typical of EPM in MRI scans.

Multiple intracranial aneurysms presenting with epistaxis.

Although epistaxis secondary to rupture of a post-traumatic, false aneurysm is well documented, true intracavernous carotid artery aneurysms presenting with epistaxis are very rare. We present such a case in a patient with multiple aneurysms. The aneurysm was treated by endovascular techniques and the patient made a good recovery. This case highlights the need to distinguish between true and false aneurysms for both diagnostic and therapeutic reasons.

Mapping the distribution of the interstitial telomeric (TTAGGG)n sequences in eight species of Brazilian marsupials (Didelphidae) by FISH and the correlation with constitutive heterochromatin. Do ITS represent evidence for fusion events in American marsupials?

The C-band pattern and the distribution of the (TTAGGG)(n) sequence after fluorescence in situ hybridization (FISH), were studied in eight species of Didelphidae marsupials: four species with 2n = 14 (Marmosops parvidens, Marmosops incanus, Marmosa murina and Metachirus nudicaudatus), two species with 2n = 18 (Monodelphis domestica and M. americana), and two with 2n = 22 (Didelphis marsupialis and Lutreolina crassicaudata). The hybridization signals were observed at both termini telomeres of all chromosomes. In addition, interstitial sequences were detected in the pericentromeric region of all chromosomes of Marmosops parvidens, in five chromosome pairs of M. incanus, and in the first pair of Monodelphis domestica. These sites always occur in the region of constitutive heterochromatin, even though C-band positive regions do not always present interstitial telomeric sequences (ITS). We suggest that the interstitial (TTAGGG)(n) sequences are associated with satellite DNA and do not necessarily arise through chromosomal rearrangements.

The comparative phylogeography of neotropical mammals: patterns of intraspecific mitochondrial DNA variation among bats contrasted to nonvolant small mammals.

The major aim of this study was to compare the phylogeographic patterns of codistributed bats and small nonvolant Neotropical mammals. Cytochrome b sequences (mitochondrial DNA) were obtained for a total of 275 bats representing 17 species. The tissue samples were collected in coastal Brazil, and were available from Mexico and the Guyana. The study concentrates on four species (Artibeus lituratus, Carollia perspicillata, Sturnira lilium and Glossophaga soricina) which were well represented. The other 13 species were sequenced to test the generality of the patterns observed. In general, sequence divergence values within species were low, with most bat species presenting less than 4% average sequence divergence, and usually between 1 and 2.5%. Clades of highly similar haplotypes enjoyed broad distribution on a continental scale. These clades were not usually geographically structured, and at a given locality the number of haplotypes was high (8-10). As distance increased, some moderately divergent clades were found, although the levels of divergence were low. This suggests a geographical effect that varied depending on species and scale. Small nonvolant mammals almost invariably have high levels of sequence divergence (> 10%) for cytochrome b over much shorter distances (< 1000 km). The grain of intraspecific variation found in small nonvolant mammals is much finer than in bats. Low levels of geographical structuring cannot be attributed to a slower evolutionary rate of bat DNA in relation to other mammalian taxa. The phylogeographic pattern of bats contrasts sharply with the pattern found for Neotropical rodents and marsupials.

The time of divergence between the two species of uacari monkeys: Cacajao calvus and Cacajao melanocephalus.

It has been suggested in the literature that primates of the genus Cacajao have been restricted to flooded-forest habitats of western Amazonia since their split from the Chiropotes line in the Tertiary. It has been proposed further that the differentiation of the two species of this genus, Cacajao melanocephalus and Cacajao calvus, occurred during the Pleistocene period as a result of the fragmentation of the Amazon forest and the isolation of populations in these forest fragments or refuges. However, recent evidence has shown that at least C. melanocephalus is not dependent on flooded-forest habitats, and molecular analysis of mitochondrial DNA shows that the two species had already differentiated during the Pliocene, thus Pleistocene glaciations do not explain the speciation in Cacajao. Considering that C. melanocephalus and its closest relative, Chiropotes, inhabit terra firme forests, it is suggested that preference for flooded-forest habitats may be an apomorphy in C. calvus.

Analysis of the changes in the proportion of clustered labelled cells in epidermis.

A new cell kinetic approach is presented from which the duration of the S and G2 + M phases can be estimated. The technique involves an analysis of the spatial distribution of labelled cells in sections or sheets of epithelium (i.e. an analysis of clustered labelled cells). The technique is largely independent of the absolute number of labelled cells and hence is not influenced by factors which affect the absolute number of labelled cells. The technique is described and experimental data from dorsal murine skin are presented. The technique has also been simulated mathematically so that the phase durations and their variances could be estimated. The advantages of the technique are: it is technically simple; it provides at least two independent estimates of the phase durations; unlabelled cells need not be counted (compare with LI or PLM analysis); it is independent of variations in the absolute yield of labelled cells, and it is applicable if the LI is low and the S phase is short (where the PLM technique tends to fail).