Zinc and Copper Concentrations in Human Preterm Milk

Zinc and copper are important trace elements in the nutrition of preterm infants. This study determined and compared the concentrations of zinc and copper in preterm milk of mothers receiving and not receiving zinc supplementation diets. The effects of maternal supplementation on the blood levels and anthropometric parameters were evaluated. Thirty-eight mothers and their preterm infants were enrolled in the study. Eighteen mothers were given a daily supplementation of 50 mg zinc, whereas the other 20 were not. Zinc and copper levels in milk were determined at 15-day intervals, as were blood zinc levels along with anthropometric parameters. Zinc and copper contents were determined by atomic absorption spectrophotometry. No significant differences were found between groups either for zinc values in maternal milk and infant blood or for anthropometric measurements. A pronounced decrease in copper levels was observed in mothers receiving supplemental zinc. Zinc supplementation given to mothers who were breastfeeding preterm infants had no significant effect on zinc secretion in milk.     

Wild Capuchins Show Male-Biased Feeding Tool Use

Relatively few studies have explored sex differences in the use of foraging tools among primates other than apes. Although male primates are thought to be more innovative, researchers have reported a female sex bias in the use of feeding tools in wild chimpanzees. We investigate here the nature and extent of sex differences in foraging tool use over 12 mo in a free-ranging group of bearded capuchins (2 males, 5 females, and 3 juveniles) living in the dry Caatinga forests of the Serra da Capivara National Park, Piaui, Brazil. These capuchins used 3 major types of feeding tools: 1) tools for probing; 2) tools for pounding/cracking; and 3) digging stones to extract tubers or roots. Adult males performed 63% (n = 134) of all events of tool use and used tools significantly more frequently than did females, although male bout lengths across all tools (57 s ± 7.9 SE) were equivalent to those of adult females (47.3 s ± 12.6 SE). Both sexes used digging and cracking tools, although at different rates, whereas adult males used sticks to probe for prey and other rewards far more than females. Differential opportunities to use tools were not apparent: >71% of tool-use events occurred on the ground, and males and females spent equal time on the ground. We suggest that sex differences in tool use may function as opportunities for male signaling of investment quality.     

Structure and dynamics of phytoplankton in an Amazon lake, Brazil

Natural lake systems represent important reservoirs for residential water supply, fish production, recreational activities and enjoyment of their natural beauty. Nevertheless, human impacts may affect their health status resulting in degradation and loss of biodiversity. The aim of the present study was to obtain data on the health status of a natural lake located in an indigenous reservation in the Brazilian Amazon, using the phytoplankton community changes along the rainy (June) and dry (November) seasons of 2006. We collected water (temperature, pH, Secchi depth and conductivity) and phytoplankton samples from the subsurface, middle of the water column, and approximately 30 cm above the bottom, over 24-hour sampling periods, from a central station in the lake. Samples taken from biotic and abiotic variables were correlated using canonical correspondence analysis (CCA). Results showed that the lake exhibited high temperatures in both seasons, and showed thermal stratification only during the rainy season. Dissolved oxygen exhibited a clinograde pattern in the rainy season and high oxygen in the hypolimnion in the dry season. In the rainy season, the water near the bottom was acidic, turbid and had a greater concentration of phosphorus. Dissolved oxygen, conductivity, pH, nitrite, total phosphorus and total dissolved phosphorus exhibited diel variations in the rainy season, whereas water temperature, dissolved oxygen, total nitrogen and total dissolved phosphorus exhibited significant differences between hours of the day in the dry season. The phytoplankton was represented by 39 taxa, and Chlorophyta showed the greatest species richness, totaling 25 taxa. Among Chlorophyta, desmids were the most diverse, accounting 52%. Bacillariophyta (nine species) was the second most diverse group. Cyanophyta was represented by three species, including Merismopedia tenuissima, the most abundant taxon. Despite the occurrence of taxa that indicate organic pollution, their biomass and frequency indicate that the system is not currently threatened. Lake Caracaran? is an oligotrophic system, with low algal density and isolated blooming episodes due to its shallow depth.     

Metallothioneins and trace elements in digestive gland,gills, kidney and gonads of Octopus vulgaris

Metallothionein-like proteins (MT) and V, Cr, Co, Ni, Zn, Cu, As and Cd were determined in digestive gland, gills, kidney and gonads of Octopus vulgaris, from the Portuguese coast. To our knowledge these are the first data on MT in octopus. High concentrations (µg g^− 1, dry mass) of Zn (48050) and Cd (555) were found in digestive gland, and MT reached levels one order of magnitude above the ones registered in wild bivalves. Significantly higher levels of MT in digestive gland and gills of specimens from A and B were in line with elevated Cd concentrations. Principal component analyses (PCA) point to MT-Cd and MT-Cr associations in digestive gland and gills. Despite the high levels of Zn in specimens from B, association with Zn was not obtained. Due to the affinity of MT to various elements, it should not be excluded the possibility of Cd replacing Zn in Zn-MT. Kidney presented higher levels of Cd, Co, Ni and As than gills and gonads, and in the case of As surpassing the levels in digestive gland, but PCA showed no relation with MT. Likewise the MT levels in gonads had no correspondence to the metal concentration variation.     

Taenia solium metacestode immunodominant peptides recognized by IgG antibodies in cerebrospinal fluid and serum paired samples from patients with active and inactive neurocysticercosis

The aim of this study was to test if serological distinction between patients with active and inactive neurocysticercosis (NCC), could be accomplished by the recognition of immunodominant peptides in total saline antigenic extract of Taenia solium metacestodes by IgG antibody in cerebrospinal fluid (CSF) and serum paired samples. CSF and serum samples of 10 each, active NCC patients, inactive NCC, and individuals with other neurological disorders, were used to recognize the antigenic peptides by western blot (WB). In the active NCC the 28-32 and 39-42 kDa peptides were more frequently detected in CSF than in sera (p < 0.05). The 47-52, 64-68, and 70 kDa antigens showed high frequencies in both samples from patients with active NCC. All the CSF samples of inactive NCC and other neurological disorder (control) patients tested negative, while serum samples from these last two groups recognized mainly the 80, 86, 95, and 98 kDa bands. This finding eliminates the use of the high molecular weigh bands (>or= 80 kDa) for diagnosis of NCC. The final conclusions were that the difference between active and inactive NCC may be done with the detection of peptides only in the CSF samples and that the 47-52, 64-68, and 70 kDa bands may be included as specific markers for active NCC when detected in CSF samples by WB using total saline extract of T. solium metacestode.     

Crystal structure of the 16 heme cytochrome from Desulfovibrio gigas: a glycosylated protein in a sulphate-reducing bacterium

Sulphate-reducing bacteria have a wide variety of periplasmic cytochromes involved in electron transfer from the periplasm to the cytoplasm. HmcA is a high molecular mass cytochrome of 550 amino acid residues that harbours 16 c-type heme groups. We report the crystal structure of HmcA isolated from the periplasm of Desulfovibrio gigas. Crystals were grown using polyethylene glycol 8K and zinc acetate, and diffracted beyond 2.1 A resolution. A multiple-wavelength anomalous dispersion experiment at the iron absorption edge enabled us to obtain good-quality phases for structure solution and model building. DgHmcA has a V-shape architecture, already observed in HmcA isolated from Desulfovibrio vulgaris Hildenborough. The presence of an oligosaccharide molecule covalently bound to an Asn residue was observed in the electron density maps of DgHmcA and confirmed by mass spectrometry. Three modified monosaccharides appear at the highly hydrophobic vertex, possibly acting as an anchor of the protein to the cytoplasmic membrane.     

Seroprevalence of Toxoplasma gondii in cats from St. Kitts, West Indies

The prevalence of antibodies to Toxoplasma gondii was determined in sera from 106 domestic cats from St. Kitts, West Indies. Using a modified agglutination test, antibodies to this parasite were found in 90 (84.9%) of the cats, with titers of 1:20 in 23 cats, 1:40 in 34 cats, 1:80 in 18 cats, 1:160 in 2 cats, 1:320 in 1 cat, and 1:1,280 or higher in 11 cats. This is the first report of the prevalence of T. gondii infections in cats on St. Kitts and suggests widespread contamination of the environment with oocysts.     

The capuchin, the howler, and the Caatinga: seed dispersal by monkeys in a threatened Brazilian forest

Regeneration of the Brazilian Caatinga forest may be restricted by the naturally low diversity and density of fruit-eating animals, which has been aggravated by local faunal extinction induced by human activities. We made a preliminary evaluation of the potential seed-dispersal role of capuchin (Cebus apella libidinosus) and howler monkeys (Alouatta caraya) in Serra da Capivara National Park. The monkeys dispersed at least 26 species. Alouatta dispersed larger seeds than Cebus, and the two species apparently dispersed seeds in different local habitats. Seed dispersal by monkeys potentially makes a significant contribution to Caatinga regeneration.