Brazilian mothers' beliefs, attitudes and practices related to child weight status and early feeding within the context of nutrition transition

With the rapid pace of the nutrition transition worldwide, understanding influences of child feeding practices within a context characterized by the co-existence of overweight and undernutrition in the same population has increasing importance. This qualitative study describes Brazilian mothers' child feeding practices and their perceptions of their association with child weight status and explores the role of socioeconomic, cultural and organizational factors on these relationships. Forty-one women enrolled in the Family Health/Community Health Workers Programme were selected from rural, urban, coastal and indigenous areas in Ceara State, north-east Brazil, to participate in four focus group discussions. Content analysis identified fourteen emergent themes showing mothers' child feeding practices in this setting were influenced by economic resources, mothers' immediate social support networks (e.g. neighbours and family members) and participation in nutrition assistance programmes. Child malnutrition was the most common nutritional concern; nevertheless, mothers were aware of the negative health consequences of obesity but misunderstood its causes (e.g. foods filled with fat would make a person fat; others thought that birth control pills and stimulants given to children were causes of obesity); several reported their own struggles with overweight. Food assistance programmes emerged as an important influence on children's dietary adequacy, especially among mothers describing dire economic situations. The findings have implications for targeting food assistance as well as health and nutrition education strategies in low-income families undergoing the nutrition transition in north-east Brazil.     

Novel genes related to nodulation, secretion systems, and surface structures revealed by a genome draft of Rhizobium tropici strain PRF 81

Rhizobium tropici is representative of the diversity of tropical rhizobia, besides comprising strains very effective in fixing N₂ in symbiosis with the common bean (Phaseolus vulgaris L.). The genome of a Brazilian commercial inoculant R. tropici strain (PRF 81, =SEMIA 4088), estimated at 7.85 Mb, was analyzed through a total of 9,026 shotgun reads, assembled in 1,668 phrap contigs, and covering ≈30% of the genome. Annotation identified 2,135 coding DNA sequences (CDS), and only 57.2% have possible functions. The genome comprises a mosaic of genes, with CDS showing the highest similarities with 134 microorganisms, none of which represents more than 19% of the CDS with putative known functions. The high saprophytic capacity of PRF 81 may reside in a variety of genes related to transport, biodegradation of xenobiotics, defense, and secretion proteins, many of which were reported for the first time in the present study. Novelty was also found in nodulation (nodG, a double nodIJ system, nodT, nolF, nolG) and capsular polysaccharide genes, showing stronger similarities with Sinorhizobium (=Ensifer) than with the main symbionts of the common bean—R. etli and R. leguminosarum—suggesting that the original host of R. tropici might be another tropical legume or emphasizing the highly promiscuous nature of this rhizobial species.     

Sensing muscle ischemia: coincident detection of acid and ATP via interplay of two ion channels

Ischemic pain--examples include the chest pain of a heart attack and the leg pain of a 30 s sprint--occurs when muscle gets too little oxygen for its metabolic need. Lactic acid cannot act alone to trigger ischemic pain because the pH change is so small. Here, we show that another compound released from ischemic muscle, adenosine tri-phosphate (ATP), works together with acid by increasing the pH sensitivity of acid-sensing ion channel number 3 (ASIC3), the molecule used by sensory neurons to detect lactic acidosis. Our data argue that ATP acts by binding to P2X receptors that form a molecular complex with ASICs; the receptor on sensory neurons appears to be P2X5, an electrically quiet ion channel. Coincident detection of acid and ATP should confer sensory selectivity for ischemia over other conditions of acidosis.     

Infection dynamics of the lungworm Rhabdias pseudosphaerocephala in its natural host, the cane toad (Bufo marinus), and in novel hosts (native Australian frogs)

Host-parasite systems have often evolved over time, such that infection dynamics may become greatly modified from the time of initial contact of the host with the parasite. Biological invasions may be useful to clarify processes in the initial contact of hosts with parasites, and allow us to compare parasite uptake between the ancestral (coevolved) host and novel (noncoevolved) hosts. Cane toads (Bufo marinus) are spreading rapidly through tropical Australia, carrying with them a nematode lungworm (Rhabdias pseudosphaerocephala) congeneric with those found in Australian frogs. We investigated the dynamics of infections of the toad parasite by conducting histologic examinations of cane toads and three native Australian frogs (Litoria dahlii, Litoria nasuta, and Opisthodon ornatus) at 2, 6, and 10 days after experimental exposure to the toad lungworm. More worms were found in toads than in frogs, especially at longer periods postexposure. In toads, the infective larvae entered the skin and muscles within 2 days postexposure, passed into the coelom in 6 days, and reached the lungs at 10 days. In frogs, larvae were found in many organs rather than migrating to consistent target tissues; a few larvae reached the lungs of L. dahlii. Migratory larvae caused increasing inflammation (primarily granulomatous admixed with granulocytes then lymphocytes) through time, especially in frogs. Evolution has resulted in an enhanced ability of the lungworm to locate the target organ (the lungs) of the toad, and an increase in rates of parasite survival within this host.     

Hairpin RNA derived from viral NIa gene confers immunity to wheat streak mosaic virus infection in transgenic wheat plants

Wheat streak mosaic virus (WSMV), vectored by Wheat curl mite, has been of great economic importance in the Great Plains of the United States and Canada. Recently, the virus has been identified in Australia, where it has spread quickly to all major wheat growing areas. The difficulties in finding adequate natural resistance in wheat prompted us to develop transgenic resistance based on RNA interference (RNAi). An RNAi construct was designed to target the nuclear inclusion protein ‘a’ (NIa) gene of WSMV. Wheat was stably cotransformed with two plasmids: pStargate‐NIa expressing hairpin RNA (hpRNA) including WSMV sequence and pCMneoSTLS2 with the nptII selectable marker. When T₁ progeny were assayed against WSMV, ten of sixteen families showed complete resistance in transgenic segregants. The resistance was classified as immunity by four criteria: no disease symptoms were produced; ELISA readings were as in uninoculated plants; viral sequences could not be detected by RT‐PCR from leaf extracts; and leaf extracts failed to give infections in susceptible plants when used in test‐inoculation experiments. Southern blot hybridization analysis indicated hpRNA transgene integrated into the wheat genome. Moreover, accumulation of small RNAs derived from the hpRNA transgene sequence positively correlated with immunity. We also showed that the selectable marker gene nptII segregated independently of the hpRNA transgene in some transgenics, and therefore demonstrated that it is possible using these techniques, to produce marker‐free WSMV immune transgenic plants. This is the first report of immunity in wheat to WSMV using a spliceable intron hpRNA strategy.     

Anti-tumor therapy with macroencapsulated endostatin producer cells

Background  

Theracyte is a polytetrafluoroethylene membrane macroencapsulation system designed to induce neovascularization at the tissue interface, protecting the cells from host's immune rejection, thereby circumventing the problem of limited half-life and variation in circulating levels. Endostatin is a potent inhibitor of angiogenesis and tumor growth. Continuous delivery of endostatin improves the efficacy and potency of the antitumoral therapy. The purpose of this study was to determine whether recombinant fibroblasts expressing endostatin encapsulated in Theracyte immunoisolation devices can be used for delivery of this therapeutic protein for treatment of mice bearing B16F10 melanoma and Ehrlich tumors.     

Effects of gamma-hexachlorocyclohexane and L-3,3',5-triiodothyronine on rat liver cytochrome P4502E1-dependent activity and content in relation to microsomal superoxide radical generation

Liver microsomal cytochrome P4502E1-dependent p-nitrophenol (PNP) hydroxylation and expression of cytochrome P4502E1 were studied in rats subjected to gamma-hexachlorocyclohexane (HCCH) or L-3,3,5-triiodothyronine (T3) administration as a possible mechanism contributing to superoxide radical (O2.-) generation. HCCH treatment (a single dose of 40 mg/kg body wt) produced a 43% increase in the content of total cytochrome P450, whereas T3 (daily doses of 0.1 mg/kg body wt for two consecutive days) led to a 37% decrease. NADPH-dependent O2.- generation was elevated by HCCH and T3, expressed as either per mg of protein or per nmol of cytochrome P450, with a 135% enhancement in the O2.- production/superoxide dismutase (SOD) activity ratios being observed in both conditions. This was partly due to depression of SOD activity. Concomitantly, the molecular activity of NADPH-cytochrome p450 reductase was enhanced by 90 and 69% by HCCH and T3, respectively. In these conditions, microsomal PNP hydroxylation showed increases of 58 and 45% in HCCH- and T3-treated rats over control values, respectively, with a parallel 31% (HCCH) and 41% (T3) enhancement in the content of cytochrome P4502E1 assessed by western immunoblotting. We conclude that HCCH and T3 enhance the expression and activity of cytochrome P4502E1 and that of NADPH-cytochrome P450 reductase in rat liver, regardless of the changes in total cytochrome P450 content, representing major contributory mechanisms to microsomal NADPH-dependent O2.- generation.     

Role of magnesium in insulin action,diabetes and cardio-metabolic syndrome X

Magnesium (Mg) is one of the most abundant ions present in living cells and its plasma concentration is remarkably constant in healthy subjects. Plasma and intracellular Mg concentrations are tightly regulated by several factors. Among them, insulin seems to be one of the most important. In vitro and in vivo studies have demonstrated that insulin may modulate the shift of Mg from extracellular to intracellular space. Intracellular Mg concentration has also been shown to be effective in modulating insulin action (mainly oxidative glucose metabolism), offset calcium-related excitation-contraction coupling, and decrease smooth cell responsiveness to depolarizing stimuli. A poor intracellular Mg concentration, as found in noninsulin-dependent diabetes mellitus (NIDDM) and in hypertensive patients, may result in a defective tyrosine-kinase activity at the insulin receptor level and exaggerated intracellular calcium concentration. Both events are responsible for the impairment in insulin action and a worsening of insulin resistance in noninsulin-dependent diabetic and hypertensive patients. By contrast, in NIDDM patients daily Mg administration, restoring a more appropriate intracellular Mg concentration, contributes to improve insulin-mediated glucose uptake. The benefits deriving- from daily Mg supplementation in NIDDM patients are further supported by epidemiological studies showing that high daily Mg intake are predictive of a lower incidence of NIDDM. In conclusion, a growing body of studies suggest that intracellular Mg may play a key role in modulating insulin-mediated glucose uptake and vascular tone. We further suggest that a reduced intracellular Mg concentration might be the missing link helping to explain the epidemiological association between NIDDM and hypertension.     

The Spanish Translation and Cultural Adaptation of Five Mental Health Outcome Measures

In this paper we report on the process of translating five mental health outcome measures into Spanish and adapting them to Latino culture. The instruments considered are the World Health Organization-Disability Assessment Scale, the Burden Assessment Scale, the Family Burden Scale, Lehman's Quality of Life Interview and the Continuity of Care in Mental Health Services Interview. A systematic process of translation and adaptation of the instruments was followed with the goal of achieving cultural equivalence between the English and Spanish versions of the instruments in five dimensions: semantic, content, technical, construct, and criterion equivalence. In this paper we present data about the semantic, content, and technical equivalence. Various steps were taken to achieve equivalence in these dimensions, including the use of a bilingual committee, a multi-national bilingual committee, back-translation, and focus groups with mental health patients and their relatives.