Effects of Low Molecular Weight Sulfated Galactan Fragments From <Emphasis Type="Italic">Botryocladia Occidentalis</Emphasis> on the Pharmacological and Enzymatic Activity of Spla2 From <Emphasis Type="Italic">Crotalus Durissus Cascavella</Emphasis>

Low molecular weight fragments of sulfated galactans (Boc-5 and Boc-10) from the red algae Botryocladia occidentalis significantly inhibited Crotalus durissus cascavella sPLA2 enzymatic activity. Equimolar ratios of sPLA2 to Boc-5 or Boc-10 resulted in allosteric inhibition of sPLA2. Under the conditions tested, we observed that both Boc-5 and Boc-10 strongly decreased edema, myonecrosis, and neurotoxicity induced by native sPLA2.     

Epidemiology and molecular characterization of hepatitis B virus in Luanda, Angola

An estimated 360 million people are infected with hepatitis B virus (HBV) worldwide. Among these, 65 million live in Africa. Despite the high levels of hepatitis B in Africa, HBV epidemiology is still poorly documented in most African countries. In this work, the epidemiological and molecular characteristics of HBV infection were evaluated among the staff, visitors and adult patients (n = 508) of a public hospital in Luanda, Angola. The overall prevalence of hepatitis B core antibody (anti-HBc) and hepatitis B surface antigen was 79.7% and 15.1%, respectively. HBV infection was higher in males and was more prevalent in individuals younger than 50 years old. HBV-DNA was detected in 100% of HBV "e" antigen-positive serum samples and in 49% of anti-hepatitis Be antibody-positive samples. Thirty-five out of the 40 HBV genotypes belonged to genotype E. Circulation of genotypes A (4 samples) and D (1 sample) was also observed. The present study demonstrates that HBV infection is endemic in Luanda, which has a predominance of genotype E. This genotype is only sporadically found outside of Africa and is thought to have emerged in Africa at a time when the trans-Atlantic slave trade had stopped.     

Soybean physiology and gene expression during drought

Soybean genotypes MG/BR46 (Conquista) and BR16, drought-tolerant and -sensitive, respectively, were compared in terms of morphophysiological and gene-expression responses to water stress during two stages of development. Gene-expression analysis showed differential responses in Gmdreb1a and Gmpip1b mRNA expression within 30 days of water-deficit initiation in MG/BR46 (Conquista) plants. Within 45 days of initiating stress, Gmp5cs and Gmpip1b had relatively higher expression. Initially, BR16 showed increased expression only for Gmdreb1a, and later (45 days) for Gmp5cs, Gmdefensin and Gmpip1b. Only BR16 presented down-regulated expression of genes, such as Gmp5cs and Gmpip1b, 30 days after the onset of moisture stress, and Gmgols after 45 days of stress. The faster perception of water stress in MG/BR46 (Conquista) and the better maintenance of up-regulated gene expression than in the sensitive BR16 genotype imply mechanisms by which the former is better adapted to tolerate moisture deficiency.     

O-Methylated mannogalactan from the microalga Coccomyxa mucigena, symbiotic partner of the lichenized fungus Peltigera aphthosa

A structural study of the carbohydrates from Coccomyxa mucigena, the symbiotic algal partner of the lichenized fungus Peltigera aphthosa, was carried out. It produced an O-methylated mannogalactan, with a (1 → 6)-linked β-galactopyranose main-chain partially substituted at O-3 by β-Galp, 3-OMe-α-Manp or α-Manp units. There were no similarities with polysaccharides previously found in the lichen thallus of P. aphthosa. Moreover, the influence of lichenization in polysaccharide production by symbiotic microalgae and the nature of the photobiont in carbohydrate production in lichen symbiosis are also discussed.     

Using dynamic pupillometry as a simple screening tool to detect autonomic neuropathy in patients with diabetes: a pilot study

Background  

Autonomic neuropathy is a common and serious complication of diabetes. Early detection is essential to enable appropriate interventional therapy and management. Dynamic pupillometry has been proposed as a simpler and more sensitive tool to detect subclinical autonomic dysfunction. The aim of this study was to investigate pupil responsiveness in diabetic subjects with and without cardiovascular autonomic neuropathy (CAN) using dynamic pupillometry in two sets of experiments.     

Kin structure and shoal composition dynamics in the guppy, Poecilia reticulata

Although kin associations between fish can develop in the laboratory, the importance of kin structure in natural social groups remains uncertain. Guppies ( Poecilia reticulata ) possess many behavioural and life-history traits that promote kin structure, and so constitute ideal candidates for testing its general significance amongst fish. We collected 25 adult only shoals from ∼150 m stretches along two Trinidadian rivers. The 272 sampled fish were genotyped from a pool of seven hypervariable microsatellite loci. Although mark-recapture experiments have previously detected male-biased dispersal, which is predicted from the guppy mating system and which may have important implications for population differentiation, we found no sex-biases in dispersal between shoals. Because sex-biased dispersal was not evident, males and females were pooled in analyses of kin structure. Relatedness levels within each shoal did not differ significantly from zero, indicating that kin selection does not contribute to gross structure. Instead, our data is more consistent with the hypothesis that individual-level selection underlies shoal composition dynamics. These dynamics have important implications for the evolution of cooperative behaviour in guppies.