Selenium content in the blood cattle from Venezuela. I. Central and Portugueste zones

Whole blood concentrations of selenium were determined in 776 dairy cows and calves from 28 farms located in three States (Aragua, Carabobo and Guárico) of the central zone of Venezuela and in Portuguesa State. Selenium levels largely varied according to both the geographic distribution and animals breed. Cattle from Guárico State showed the lowest average concentration (0.21 ppm) and those from Portuguesa the highest one (0.67 ppm). A group of animals from Turén (a District of Portuguesa State) showed the highest average concentration (1.64 ppm, range 1.02 +/- to 3.24 ppm). Concentrations of this magnitude in animals under grazing conditions could be related to high levels of selenium either in the soil or in the pasture. It is concluded that such animals are localized inaseleniferous zone (Turén). It must be noted that Jaffé et al. (op. cit.) found high levels of selenium in sesame seeds (Sesamum indicum) from this area and in blood and urine samples of children from Villa Bruzual, a little town of Turén. The results of this wok significantly differ from those obtained in other countries (of Europe and North America), where animals are managed under conditions very different from those of the tropical areas like Venezuela. The role this factor is discussed. This is the first report on blood levels in large animals of economical importance in Venezuela.     

从真空炼硒炉渣中回收硒

采用焙烧浸出净化还原的工艺处理真空蒸硒炉渣，试验结果硒回收率９００９％，硒粉品位＞９９．５％。     

Selenium content in cattle hair in areas with incidence of nutrition-induced muscular dystrophy

In the South Bohemian Region which is an area of enzootic incidence of nutritional muscle dystrophy selenium content in the fur of dairy cows and young cattle was determined. In the breeds in which the "white muscle disease" appeared in the past years in young cattle, lambs and calves the lowest mean selenium values in the fur dry matter found were: 0.18 +/- 0.07, 0.19 +/- 0.06, and 0.21 +/- 0.08 ppm, with repeated findings of mere 0.09 ppm Se. 60 to 100 per cent samples from these farms showed selenium values below the 0.25 ppm level. The fur of heifers which recovered from nutritional muscle dystrophy and were treated 10 days prior to sampling with a selenium preparation in injection form (Selevit inf. SPOFA) contained 0.29 ppm selenium (+/- 0.11). In other breeds 0.30 +/- 0.07 to 3.33 +/- 0.16 ppm selenium was found in the fur of cows and young cattle. The initial field essay of selenium content in cattle fur indicated a relation of low selenium values to the frequency of clinical forms of nutritional muscle dystrophy in domestic ruminants.     

Ectodomain phosphorylation of beta-amyloid precursor protein at two distinct cellular locations

The beta-amyloid precursor protein (betaAPP) is a transmembrane protein that is exclusively phosphorylated on serine residues within its ectodomain. To identify the cellular site of betaAPP phosphorylation, we took advantage of an antibody that specifically detects the free C terminus of beta-secretase-cleaved betaAPP containing the Swedish missense mutation (APPssw-beta). This antibody previously established the cellular location of the beta-secretase cleavage of Swedish betaAPP as a post-Golgi secretory compartment (Haass, C., Lemere, C., Capell, A., Citron, M., Seubert, P., Schenk, D., Lannfelt, L., and Selkoe, D. J. (1995) Nature Med. 1, 1291-1296). We have now localized the selective ectodomain phosphorylation of betaAPP to the same compartment. Moreover, the phosphorylation sites of betaAPP were identified at Ser198 and Ser206 of betaAPP695 by tryptic peptide mapping, mass spectrometry, and site-directed mutagenesis. Intracellular phosphorylation of betaAPP was inhibited by Brefeldin A and by incubating cells at 20 degrees C, thus excluding phosphorylation in the endoplasmic reticulum or trans-Golgi network. Ectodomain phosphorylation within a post-Golgi compartment occurred not only with mutant Swedish betaAPP, but also with wild type betaAPP. In addition to phosphorylation within a post-Golgi compartment, betaAPP was also found to undergo phosphorylation at the cell surface by an ectoprotein kinase. Therefore, this study revealed two distinct cellular locations for betaAPP phosphorylation.     

High temporal, geographic, and income variation in body mass index among adults in Brazil

OBJECTIVES: Population-based data on body mass index for developing countries are scarce. Body mass index data from two Brazilian surveys were examined to determine regional and temporal variations in the prevalences of underweight, overweight, and obesity. METHODS: Nationwide surveys in 1974/75 and 1989 collected anthropometric data in Brazil from 55,000 and 14,455 households, respectively. Trained interviewers used the same methods to measure weight and stature in both surveys, and survey designs were identical. Prevalences of underweight, overweight, and obesity were determined for persons 18 years of age and older. RESULTS: In the 1989 survey, body mass index varied greatly according to region of the country, urbanization, and income. In the wealthier South, the prevalence of overweight/obesity was the highest and the prevalence of underweight was the lowest; in the poorer rural Northeast, these patterns were reversed. For both surveys, overweight/obesity was more common among women than among men and peaked at age 45 to 64 years in both sexes. Over the 15 years between surveys, the prevalence of both overweight and obesity increased strikingly. CONCLUSIONS: In contrast to findings in developed countries, obesity in Brazil was positively associated with income and was much more prevalent among women than among men. For Brazilian women, the overall prevalence of overweight was nearly as high as that among women in the United States.     

某复杂低汞硒渣富集分离回收硒汞试验

采用两次焙烧工艺从某复杂低汞硒渣中富集分离回收硒、汞。首先将该硒汞渣在不制粒情况下,800~850℃空白焙烧1.5h,99%以上的硒、汞挥发进入烟尘而富集,且焙烧渣中汞含量不足0.01%。富集硒、汞的烟尘与石灰(CaO加入量为理论值1.25倍)制粒后在650℃焙烧90 min,固硒率达到99.5%,汞脱除率达到99.41%。     

Toxoplasmosis in naturally infected deer from Brazil

Serum samples from 107 cervids were examined for Toxoplasma gondii antibodies using indirect hemagglutination (IHA), indirect immunofluorescence (IFA), enzyme linked immunosorbent assay (ELISA) and Dot-ELISA. Samples were obtained from 66 marsh deer (Blastocerus dichotomus) in the State of S?o Paulo (Brazil) and from 41 pampas deer (Ozotocerus bezoarticus) in the State of Goiás (Brazil). Antibodies to T. gondii were found in 23 (22%) of the deer, with 18 and 5 positive samples, respectively, for B. dichotomus and O. bezoarticus. The highest prevalence of T. gondii antibodies were young adults (32%), following by adults (27%) and fawns (13%). Only one serum sample (8%) from a newborn fawn was positive in the serological tests. The convenience of the Dot-ELISA test is obvious when compared with other serological tests for both laboratory or field surveys, mainly due to its features of practicability and reagent stability.     

Frequency of schistosomiasis mansoni, of its clinicopathological forms and of the ectopic locations of the parasite in autopsies in Belo Horizonte, Brazil

The frequency of schistosomiasis mansoni, of its clinicopathological forms, and of the distribution of Schistosoma mansoni eggs in ectopic locations in each clinicopathological form were studied in 1863 complete consecutive autopsies performed in Belo Horizonte, Brazil, in the period from 1971 to 1990. Three hundred and thirteen cases of S. mansoni infection (16.8%) were found. The intestinal form was the most frequent (67.4%), followed by the hepatosplenic form without pulmonary hypertension (24.9%). The intestinal form showed a smaller number of ectopic sites and a lower percentage of involvement of these sites compared to the more severe forms, particularly the hepatosplenic form with pulmonary hypertension. The distribution of the frequency of schistosomiasis mansoni cases, of the clinicopathological forms of the disease, and of the ectopic sites of S. mansoni eggs over the decades considered showed a marked reduction in all of these parameters, particularly in the more severe forms. These findings can be explained only by earlier diagnosis of the disease and the greater efficacy of the specific chemotherapy used today, preventing progression to the more severe forms of the parasitosis.     

Analysis of the sorting signals directing NADH-cytochrome b5 reductase to two locations within yeast mitochondria

Mitochondrial NADH-cytochrome b5 reductase (Mcr1p) is encoded by a single nuclear gene and imported into two different submitochondrial compartments: the outer membrane and the intermembrane space. We now show that the amino-terminal 47 amino acids suffice to target the Mcr1 protein to both destinations. The first 12 residues of this sequence function as a weak matrix-targeting signal; the remaining residues are mostly hydrophobic and serve as an intramitochondrial sorting signal for the outer membrane and the intermembrane space. A double point mutation within the hydrophobic region of the targeting sequence virtually abolishes the ability of the precursor to be inserted into the outer membrane but increases the efficiency of transport into the intermembrane space. Import of Mcr1p into the intermembrane space requires an electrochemical potential across the inner membrane, as well as ATP in the matrix, and is strongly impaired in mitochondria lacking Tom7p or Tim11p, two components of the translocation machineries in the outer and inner mitochondrial membranes, respectively. These results indicate that intramitochondrial sorting of the Mcr1 protein is mediated by specific interactions between the bipartite targeting sequence and components of both mitochondrial translocation systems.     

The traditional and emerging role of nuts in healthful diets

Throughout history, nuts have been a staple food providing energy, protein, essential fatty acids, vitamins, and minerals. Today, nuts are classified as part of the USDA Food Guide Pyramid's Meat/ Meat Alternate Group. Foods in this group contribute protein as well as important vitamins and minerals to the diet. Nuts are also being studied for their potential health benefits. Research suggests that there may be a connection between frequent nut consumption and a reduced incidence of coronary heart disease. Thus, tradition and promising scientific evidence combine to support the role of nuts in healthful eating.     

从碲碱渣中分离硒回收碲

广西某有色金属冶炼企业产铜阳极泥,在回收贵金属时产生的碲碱渣含碲量高达32%,现有工艺碲回收率低。针对在阳极泥熔炼生产过程中产出的碲碱渣开展湿法浸出试验,采用水浸—H2SO4中和—HONH3Cl沉硒—Na2SO3还原工艺处理碲碱渣,考察了水浸时间、液固比、温度对碲浸出效率的影响,同时探究盐酸羟胺沉硒温度、时间、盐酸羟胺用量对硒分离效果的影响。结果表明：水浸时间1 h、液固比4、温度55 ℃时,碲浸出效率达到最佳;盐酸羟胺沉硒温度80 ℃、沉硒时间2 h、盐酸羟胺为理论用量的3倍时,沉硒效果达到最佳,其分离率＞99.99%,回收碲粉纯度高达99%以上。该工艺可以有效地分离硒回收碲,具有过程简单、生产环境安全、成本低,高效率的特点,具有产业化前景。     

浅谈贵冶铜阳极泥中硒的回收

针对贵冶铜阳极泥在回转窑硫酸化焙烧蒸硒工序过程中存在二氧化硒吸收不完全、粗硒回收率低等问题,通过强化过程控制和工艺优化,摸索出了回转窑泥酸比、温度、负压三大工艺参数控制模式,采用低泥酸比硫酸化焙烧和烟气高效吸收成套技术,蒸硒渣含硒量稳定在0.15%～0.29%,粗硒回收率提高了20%以上。     

Activation of locations in working memory in cats

Cats saw an object appear and disappear at two successive locations; the movement of the object from one location to the other was not perceived but was indicated by indirect cues and the two disappearances were separated by a 0-sec or a 20-sec interval. Performance was poorer with the 0-sec than with the 20-sec interval. With the 0-sec interval, the percentages of search attempts made at the object's initial and final hiding locations did not differ whereas with the 20-sec interval, more search attempts were made at the final than at the initial location. These results provide additional support to Goulet, Doré and Rousseau's (1994) interpretation of cats' search behaviour in terms of activation of spatial locations in working memory.     

A study of the hydrogen-induced degradation of two steels differing in sulfur content

Two steels with different sulfur contents: 0.003 and 0.024 wt pct, were cathodically charged under three different conditions and brought to fracture in tension immediately after charging or after aging at room temperature. All hydrogen charged specimens showed embrittlement, with a little higher loss of ductility in the high sulfur steel. The hydrogen embrittlement was reversible in both steels when specimens were charged in arsenic-free sulfuric acid solution at room temperature but was irreversible when charged in arsenic-containing acid at the same temperature. After charging in molten salts at 200 °C, some of the low sulfur steel specimens exhibited irreversible hydrogen damage with the appearance of quasicleavage fractures, while all high sulfur steel specimens were restored to the uncharged ductility by aging at room temperature. These results are interpreted by assuming that an increased sulfur content in steel increases the density of trapping sites for hydrogen at the sulfide/matrix interfaces. These traps are inactive above 150 °C and become operative after cooling. Therefore, at the same hydrogen content in steel after cooling, the greater content of sulfur results in a decreased activity of the lattice dissolved hydrogen, hence in reduced embrittlement.     

Charged amino acids at the carboxyl-terminal portions determine the intracellular locations of two isoforms of cytochrome b5

Outer mitochondrial membrane cytochrome b5 (OMb), which is an isoform of cytochrome b5 (cyt b5) in the endoplasmic reticulum, is a typical tail-anchored protein of the outer mitochondrial membrane. We cloned cDNA containing the complete amino acid sequence of OMb and found that the protein has no typical structural feature common to the mitochondrial targeting signal at the amino terminus. To identify the region responsible for the mitochondrial targeting of OMb, various mutated proteins were expressed in cultured mammalian cells, and the subcellular localization of the expressed proteins was analyzed. The deletion of more than 11 amino acid residues from the carboxyl-terminal end of OMb abolished the targeting of the protein to the mitochondria. When the carboxyl-terminal 10 amino acids of OMb were fused to the cyt b5 that was previously deleted in the corresponding 10 residues, the fused protein localized in the mitochondria, thereby indicating that the carboxyl-terminal 10 amino acid residues of OMb have sufficient information to transport OMb to the mitochondria. The replacement of either of the two positively charged residues within the carboxyl-terminal 10 amino acids by alanine resulted in the transport of the mutant proteins to the endoplasmic reticulum. The mutant cyt b5, in which the acidic amino acid in its carboxyl-terminal end was replaced by basic amino acid, could be transported to the mitochondria. It would thus seem that charged amino acids in the carboxyl-terminal portion of these proteins determine their locations in the cell.     

Antimicrobial drug resistance in Staphylococcus aureus isolated from cattle in Brazil

Isolates of Staphylococcus aureus obtained from apparently healthy cattle in the State of Paraiba, Brazil were characterized in relation to resistance to 21 antimicrobial agents. Among the 46 isolates obtained, resistance to penicillin was most frequent, followed by resistance to cadmium, streptomycin, arsenate, tetracycline, mercury, erythromycin and kanamycin/neomycin. All isolates were susceptible to fusidic acid, ethidium bromide, cetrimide, chloramphenicol, benzalkonium chloride, doxycycline, gentamicin, methicillin, minocycline, novobiocin, rifamycin, tylosin and vancomycin. Only six isolates were susceptible to all the drugs tested. With respect to the antibiotics, multi-resistant isolates were uncommon. These results are probably a consequence of the peculiarities of local drug usage pressures. In relation to metal ions, resistance to mercury was rare while resistance to arsenate was relatively frequent, which contrasts with the situation for human Staph. aureus strains. After treatment with ethidium bromide, elimination of resistance to penicillin, tetracycline, streptomycin, erythromycin and cadmium was observed, which was consistent with the genetic determinants being plasmid-borne.     

Do irregular letter combinations attract readers' attention? Evidence from fixation locations in words.

J. Hy?n?, P. Niemi, and G. Underwood (1989) provided evidence suggesting that in reading, the initial fixation lands farther into a word that has an informative as opposed to a redundant ending. The finding points to the potential importance of the within-word information distribution in determining fixation locations in words. However, the reliability of the effect has been recently challenged by K. Rayner and R. Morris (1992). The current study did not find much support for the notion that the relative informativeness of word endings would be a relevant factor in eye guidance. On the other hand, it did show that a highly irregular letter cluster in the beginning of a word attracts a fixation closer toward the word beginning, particularly to the space prior to the word. This finding is discussed in light of visual guidance models that emphasize the relevance of word length and spacing information for governing the eyes through a text. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Prevalence of two species of Litomosoides (Nematoda: Filarioidea) parasites of Akodon cursor (Rodentia: Muridae) from southeastern Brazil

The ATB NH system designed for antibiotic susceptibility testing of Neisseria gonorrhoeae, Neisseria meningitidis and Haemophilus influenzae was evaluated using 94 clinical isolates of gonococci representing a wide variety of serovar/auxotype strains. Using the manufacturer's automated system 55% of the clinical isolates failed to grow, compared with a 33% failure rate for manual processing and visual reading. Growth failure was significantly higher with 1A isolates (73% automated and 69% manual) than with 1B isolates (49% automated and 25% manual). The higher failure rate of 1A isolates correlated with multiple auxotrophy. The inability of the ATB NH system to support the growth of common serovar/auxotypes makes the ATB NH system unsuitable for antibiotic susceptibility testing of N. gonorrhoeae.