Vagotomy reduces obesity in MSG-treated rats

In order to study the role of vagus nerve activity at the onset of obesity induced by monosodium glutamate (MSG), 30-day-old MSG-rats were vagotomized or sham operated. Body weight and food intake were recorded until animals were 90 days old and then sacrificed. Naso-anal length was recorded for all animals. Periepididymal and retroperitoneal fat pads were isolated and weighed. Reduction of body weight and naso-anal length were registered in 30-day-old MSG-rats. Obesity could also be observed, as increase of Lee index indicated. Results were most evident in 90-day-old MSG-rats. In both groups neither body weight gain nor food intake was changed by vagotomy. However, fat accumulation on tissues was reduced by vagotomy in MSG-rats. The results showed that MSG-obesity is not related to an increment in food intake behavior. Vagotonia might play a role at the onset of MSG-obesity.     

NMR studies on energy metabolism of immobilized primary neurons and astrocytes during hypoxia, ischemia and hypoglycemia

Changes in high-energy phosphate metabolites (ATP and phosphocreatine) were monitored, in real time, by 31P-nuclear magnetic resonance in primary cell cultures of neurons and astrocytes during periods of hypoxia, ischemia and hypoglycemia, and also during the recovery periods following the re-establishment of standard conditions. Cells were immobilized in basement membrane gel threads and perfused with oxygen-depleted medium (oxygen concentration below 30 microM), to create hypoxic conditions, or with aerobic medium (oxygen concentration approximately 460 microM) containing different concentrations of glucose (hypoglycemia). Ischemic conditions were imposed by stopping perfusion for different periods of time (15 min to 2 h). The experimental set-up enabled the acquisition of 31P-spectra with high signal-to-noise ratio within 10-20 min for both cell types. The effect of hypoxia on glucose metabolism was assessed by 13C-NMR using [1-13C]glucose as substrate. The levels of ATP and PCr in astrocytes were unaffected during hypoxia (up to 2 h), but decreased notably under ischemia. In neurons, hypoxic periods caused a sharp drop of the ATP and PCr levels, and considerable damage to the capacity of neurons to replenish the ATP and PCr pools upon returning to normoxic conditions. However, neurons were remarkably less sensitive to ischemic conditions, the ATP and PCr pools being restored quickly, even after 2 h under challenging conditions. The data show that neurons were more resistant to ischemia than astrocytes, and suggest that the capacity to sustain the pools of ATP and PCr was part of the neuronal protective strategy.     

Anatomy of spontaneous splenorenal and gastrorenal venous anastomoses: Review of the literature

Summary Portal hypertension is characterised by the development of a collateral portocaval circulation. Among these venous reroutings, some are situated posteriorly in the left subphrenic compartment. These are the spontaneous splenorenal and gastrorenal anastomoses. Their incidence is estimated at around 16%. On the one hand, there are the direct shunts, which anastomose the spelling v. to the left renal v., of an anecdotal nature, and on the other the spontaneous indirect splenorenal shunts, characterised by the presence of a complete neurovascular pedicle traversing the gastrophrenic ligament. This relates to the gastric collateral v., which is connected to the left renal v. via the inferior v. of the left crus of the diaphragm and the middle capsular v., hence the name gastro-phreno-capsulorenal shunt. At an advanced stage of portal hypertension these splenorenal shunts may acquire a major caliber and behave like actual surgical shunts.

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Anatomie des anastomoses veineuses spléno-rénale et gastro-rénales spontanées: revue de la littérature

Résumé L'hypertension portale se caractérise par le développement d'une circulation collatérale porto-cave. Parmi ces dérivations veineuses, certaines ont une topographie postérieure, localisée dans la loge sous-phrénique gauche. Ce sont les anastomoses spontanées splénorénales et gastro-rénales. Leur prévalence est estimée aux alentours de 16%. On distingue, d'une part, les shunts directs, qui anastomosent la v. splénique à la v. rénale gauche, de constatation anecdotique, non systématisés sur le plan anatomique ; d'autre part, les shunts splénorénaux spontanés indirects caractérisés par l'existence d'un pédicule complet vasculo-nerveux, cheminant dans le ligament gastro-phrénique. Il s'agit de la v. collatérale gastrique qui est reliée à la v. rénale gauche par l'intermédiaire de la v. inférieure du pilier gauche du diaphragme et de la v. capsulaire moyenne, d'où le nom de shunt gastro-phrénocapsulo-rénal. A un stade avancé de l'hypertension portale, ces shunts splénorénaux peuvent acquérir un calibre important et se comporter alors comme de véritables shunts chirurgicaux.

     

Seasonal malaria transmission and variation of anopheline density in two distinct endemic areas in Brazilian Amazonia

Studies on seasonal anopheline fauna variation were performed in two distinct settlements in the State of Rond?nia, Brazil: one at the Madeira River banks (Portuchuelo) with stable native Amazonian population; the other at an inland lumber-extracting farm (Urupá) in dry land, in which adults are mostly migrants. During a 6-yr period (1994-2000), 8,638 adult anophelines were collected: 2,684 in Urupá and 5,954 in Portuchuelo. Anopheles darlingi represented >95% of total mosquitoes caught. Dissection of 4,424 A. darlingi females yielded a very low sporozoite infection index below 0.1%. Oocysts were found in both localities in approximately 0.1% of dissected mosquitoes. Determination of the hour biting rates disclosed seasonal variations in both localities. However, in Portuchuelo, mosquito density peaked at the acme of the rainy season, whereas at Urupá it peaked in the dry season. The increase in mosquito density and incidence of malaria cases were coincident. The high mosquito densities observed in the riverine settlement of Portochuelo sector B, which permits evaluation in > 10,000 mosquitoes' bites/person/year, could explain, in spite of the low mosquito's infection index, the previously described development of natural immunity in the local population that is not observed in the dry land agroindustrial settlement of Urupá.     

Partitioning of whey proteins, bovine serum albumin and porcine insulin in aqueous two-phase systems

Partitioning of the proteins from cheese whey, bovine serum albumin and porcine insulin were analysed using aqueous two-phase systems (ATPS) prepared with PEG-phosphate, PEG-citrate and PEG-maltodextrin (MD). Proteins were quantified through one of the following methods: FPLC, Bradford and spectrophotometry at 280 nm. Results showed that whey proteins partitioned unevenly on the phases of the systems used, with alpha-lactoalbumin (alpha-La) concentrated in the upper phase and beta-lactoglobulin (beta-Lg) in the lower. Albumin in PEG-MD systems concentrated in the MD-rich lower phase. Porcine insulin showed great affinity with the PEG-rich phase, its partition coefficient was always over 10 and increases with PEG molecular mass.     

Differential distribution of estrogen receptor (ER)-alpha and ER-beta in the midbrain raphe nuclei and periaqueductal gray in male mouse: Predominant role of ER-beta in midbrain serotonergic systems

We examined the distribution of estrogen receptor (ER)-alpha and ER-beta immunoreactive (ir) cells in the dorsal (DRN) and median/paramedian (MPRN) raphe nuclei in male mice. ER-alpha ir neurons were scattered across the three subdivisions (ventral, dorsal, and lateral) of the DRN and the MPRN. Robust ER-beta ir cells were observed throughout the raphe nuclei, and were particularly abundant in the ventral and dorsal subdivisions of the DRN. Using dual-label immunocytochemistry for ER-alpha or ER-beta with tryptophan hydroxylase (TPH), the rate-limiting enzyme for 5-hydroxytryptamine (5-HT) synthesis, over 90% of ER-beta ir cells exhibited TPH-ir in all DRN subdivisions, whereas only 23% of ER-alpha ir cells contained TPH. Comparisons of ER-alpha knockout (alphaERKO) as well as ER-beta knockout (betaERKO) mice with their respective wild-type (WT) littermates revealed that gene disruption of either ER-alpha or ER-beta did not affect the other ER subtype expression in the raphe nuclei. In situ hybridization histochemistry revealed that there was a small but statistically significant decrease in TPH mRNA expression in the ventral DRN subdivision in betaERKO mice compared with betaWT mice, whereas TPH mRNA levels were not affected in alphaERKO mice. These findings support a hypothesis that ER-beta activation may contribute to the estrogenic regulation of neuroendocrine and behavioral functions, in part, by acting directly on 5-HT neurons in the raphe nuclei in male mice.     

Recently amplified satellite DNA inCallithrix argentata (Primates,Platyrrhini)

A satellite DNA has been cloned from the neotropical primateCallithrix argentata and designated CarB. The presence of the satellite was assayed in New and Old World primates by blot hybridization: CarB is highly amplified in the genomes of all three species belonging to theC. argentata species group (C. argentata, C. emiliae, C. humeralifer), but is either absent, or present in only minor amounts, in other primates, including the closely related species,C. jacchus. A completely sequenced CarB monomeric unit was 1528 bp in length and mapped to the telomeric C-band-positive regions of manyC. argentata species group chromosomes. Sequence data from eight CarB clones indicated an average difference of 3.5% when base substitutions alone were counted. The hybridization and sequence data suggest that this satellite underwent a period of amplification and dispersal in the genome of a recent ancestor of theC. argentata species group.     

Histopathological aspects of Dengue-2 virus infected mice tissues and complementary virus isolation

The difficulty in studying dengue virus (DENV) infection in humans and in developing a virus vaccine is the absence of a suitable animal model which develops the full spectra of the Dengue haemorrhagic fever (DHF) and Dengue shock syndrome (DSS). Despite the fact that viruses have been found in various animal tissues, we isolated DENV from tissues of adult BALB/c mice, inoculated with DENV serotype 2 (DENV-2) obtained from human serum. Viruses were ultrastructurally identified and immunolocalized by immunofluorescence techniques in C6/36 mosquito cell cultures, inoculated with tissues (liver, lung, kidney and cerebellum) macerate supernatant from mice, 48 h post-infection (p.i.). These organs, collected at the same stage of infection, were examined histologically. The histopathological analysis revealed focal alterations in all tissues examined. Liver contained focal ballooned hepatocytes, but without modifying the average diameter of the majority of hepatocytes. Sinusoidal lumen was significantly diminished at this stage but portal and centrolobular veins became congested. Lungs exhibited hemorrhagic foci in the alveolar space, vascular congestion and focal alveolitis. Cerebellar tissue showed rare foci of neuronal compactation (Purkinje cells) and perivascular oedema. In kidneys it was observed an increase in glomerular volume with augmented endocapillary and mesangial cellularity, with reactivity to anti-IgM in all glomeruli of infected mice. In conclusion, DENV-2 was found in all tissues examined early in the evolution of infection. Presence of viruses in tissues has mainly led to hemodynamic alterations with generalized vascular congestion and increased permeability, and mast cell recruitment in lungs. The latter could participate in the vascular modifications in tissues.     

Genetic association of the PERIOD3 (PER3) Clock gene with extreme obesity

BackgroundObesity has reached epidemic proportions worldwide, affecting life quality and span. Susceptibility to obesity is partly mediated by genetic differences. Indeed, several genes from the clock gene family have already been shown to be intimately associated with obesity in diverse ethnic groups. In the present study, an association between BMI and the rs707467, rs228697 and rs228729 PER3 (Period Circadian Clock 3) polymorphisms in subjects with class II (BMI ≥ 35.0–39.9 kg/m²) and class III obesity (>40 kg/m², extreme obesity) were carried out using TaqMan real-time PCR. Overall, 259 Brazilian adults were genotyped, of whom 122 had class II or III obesity (BMI ≥ 35.0 kg/m²) and 137 were controls having normal weight (BMI > 18.5 and <24.9 kg/m²).ResultsPER3 tag SNP (rs228729) shows a significant association with extreme obesity (1000 permutation p = 0.03 and p = 0.04), for genotype and allele frequency respectively) and a haplotype among the three assessed SNPs (alleles G/T/A, rs228697, rs228729, and rs707467, respectively, 1000 permutation p = 0.03) was significantly more prevalent in the group with obesity.ConclusionThis exploratory association study suggests that PER3 rs228729 may be associated with extreme obesity in Brazilian adults, however, replication is needed.