Traditional living in the Amazon: Extended breastfeeding,fish consumption,mercury exposure and neurodevelopment

Abstract

Background: Features of traditional living in the Amazon Basin (high fish consumption and long breastfeeding) are likely to expose children to Mercury (Hg).

Aim: To study neurodevelopment in 690 children in relation to prolonged breastfeeding and mercury exposure.

Subjects and methods: Three groups of breastfeeding children were formed: Group 1 (breastfed for 6 months), Group 2 (7–12 months) and Group 3 (extending up to 24 months). Neurodevelopment was assessed as age of walking, age of talking and the Bayley Scales of Infant Development–BSID. Mercury exposure was assessed from Thimerosal-containing vaccines and fish consumption from hair Hg (HHg).

Results and conclusions: HHg increased in children and decreased in mothers at 24 months. Frequency of fish consumption was significantly correlated with maternal HHg at birth (Spearman’s r?=?0.8583; p?=?0.0001); likewise, there was a significant correlation between duration of breastfeeding and children’s HHg (Spearman’s r?=?0.15; p?=?0.0018). Extended breastfeeding did not influence the Mental Development Index–MDI or Psychomotor Development Index–PDI, but maternal education and HHg (marker of fish consumption) interacted positively and significantly with both. Frequency of maternal fish consumption and education had a positive association with BSID scores; it is speculated that maternal education and nutrients in fish have an opposing effect on Hg exposure.     

Fish consumption by traditional subsistence villagers of the Rio Madeira (Amazon): Impact on hair mercury

Abstract

Background: Subsistence ribeirinhos of the Amazon Basin depend on fish for their principal source of protein, but fish availability changes with seasonal high and low waters.

Aim: To assess taxa and quantity of fish consumed and estimate attendant exposure to methyl-Hg in a traditional subsistence high fish-eating community of the Amazon Basin.

Subjects and methods: 120 villagers in 18 households were followed for 6 months (August to February) for weighed portions of fish consumed.

Results: Mean daily per capita fish consumption was high (406 g/day) with fish meals ranging from 4 to 14 times/week and an integrated yearly consumption of 148.2 kg/person. Median total-Hg concentrations in fish ranged from 0.011 to 0.409 ppm; six of the more consumed fish species comprised more than 50% of the fish consumed. The villagers mean hair-Hg concentration was high (17.4 ± 11.5 μg/g), with both inter- and intra-household variation despite similar high fish consumption; only 7% showed hair-Hg concentrations < 5 μg/g, but 75% had hair-Hg levels above 10 μg/g. Maternal hair-Hg was significantly correlated with respective children's hair-Hg (Spearman r = 0.5390; p < 0.0001). The high daily fish intake of these villagers is predominantly of species with much lower Hg concentrations.

Conclusion: In Amazonian lifestyle of ribeirinho communities traditional fish consumption is high and depends on available species; fish is also the principal via of meHg exposure and attendant hair-Hg concentrations.     

Mercury biomarkers and DNA methylation among michigan dental professionals

Modification of the epigenome may be a mechanism underlying toxicity and disease following chemical exposure. Animal and human data suggest that mercury (Hg) impacts DNA methylation. We hypothesize that methylmercury and inorganic Hg exposures from fish consumption and dental amalgams, respectively, may be associated with altered DNA methylation at global repetitive elements (long interspersed elements, LINE‐1) and candidate genes related to epigenetic processes (DNMT1) and protection against Hg toxicity (SEPW1, SEPP1). Dental professionals were recruited at Michigan Dental Association (MDA) meetings in 2009 and 2010. Subjects (n = 131) provided survey data (e.g. exposure sources, demographics) and biological samples for Hg measurement and epigenetic analysis. Total Hg was quantified via atomic absorption spectrophotometry in hair and urine, indicative of methylmercury and inorganic Hg exposures, respectively. Global repetitive and candidate gene methylation was quantified via pyrosequencing of bisulfite converted DNA isolated from buccal mucosa. Hair Hg (geometric mean (95% CI): 0.37 (0.31–0.44) µg/g) and urine Hg (0.70 (0.60–0.83) µg/L) were associated with sources of exposure (fish consumption and dental amalgams, respectively). Multivariable linear regression revealed a trend of SEPP1 hypomethylation with increasing hair Hg levels, and this was significant (P < 0.05) among males. The trend remained when excluding non‐dentists. No significant relationships between urine Hg and DNA methylation were observed. Thus, in a limited cohort, we identified an association between methylmercury exposure and hypomethylation of a potentially labile region of the genome (SEPP1 promoter), and this relationship was gender specific. Environ. Mol. Mutagen. 54:195–203, 2013. © 2013 Wiley Periodicals, Inc.     

The effect of body shape on weight-for-height and mid-upper arm circumference based case definitions of acute malnutrition in Ethiopian children

Background: Nutritional anthropometry surveys from Somalia and Ethiopia have reported that standard weight-for-height z-score (WHZ) and mid-upper arm circumference (MUAC) case definitions return different estimates of the prevalence of acute malnutrition in pastoralist livelihood zones but similar estimates of the prevalence of acute malnutrition in the agrarian livelihood zones. A study undertaken in Somalia to investigate this finding reported that children from pastoralist livelihood zones tended to have longer limbs and lower SSRs than children from agrarian livelihood zones.

Aim: The present study investigated the relationship between weight-for-height and body shape and the relationship between MUAC and body shape in different populations of Ethiopian children.

Subjects and methods: Six cross-sectional nutritional anthropometry surveys were undertaken. The combined survey datasets form the study sample. Data sources were grouped according to the livelihood zone from which data originated (either settled agrarian or semi-nomadic pastoralist). Case definitions of acute malnutrition using WHZ calculated using the NCHS and WHO reference populations and MUAC uncorrected for age or height were used. The SSR was used as an index of body shape. The association between body shape and the different case definitions of acute malnutrition were investigated using standard statistical techniques.

Results: Weight-for-height and MUAC case definitions yielded similar estimates of the prevalence of acute malnutrition in agrarian children but different estimates of the prevalence of acute malnutrition in pastoralist children. These populations also exhibit different SSRs. The SSR is an important predictor of weight-for-height. The SSR is a poor predictor of MUAC.

Conclusion: WHZ and WHZ case status in children are associated with body shape and may overestimate the prevalence of acute malnutrition in some populations. Consideration should be given as to whether WHZ should be replaced by MUAC for the purposes of estimating the prevalence of acute malnutrition.     

Fish oil in infancy protects against food allergy in Iceland—Results from a birth cohort study

Background

Consumption of oily fish or fish oil during pregnancy, lactation and infancy has been linked to a reduction in the development of allergic diseases in childhood.

Methods

In an observational study, Icelandic children (n = 1304) were prospectively followed from birth to 2.5 years with detailed questionnaires administered at birth and at 1 and 2 years of age, including questions about fish oil supplementation. Children with suspected food allergy were invited for physical examinations, allergic sensitization tests, and a double‐blind, placebo‐controlled food challenge if the allergy testing or clinical history indicated food allergy. The study investigated the development of sensitization to food and confirmed food allergy according to age and frequency of postnatal fish oil supplementation using proportional hazards modelling.

Results

The incidence of diagnosed food sensitization was significantly lower in children who received regular fish oil supplementation (relative risk: 0.51, 95% confidence interval: 0.32‐0.82). The incidence of challenge‐confirmed food allergy was also reduced, although not statistically significant (0.57, 0.30‐1.12). Children who began to receive fish oil in their first half year of life were significantly more protected than those who began later (P = .045 for sensitization, P = .018 for allergy). Indicators of allergy severity decreased with increased fish oil consumption (P = .013). Adjusting for parent education and allergic family history did not change the results.

Conclusion

Postnatal fish oil consumption is associated with decreased food sensitization and food allergies in infants and may provide an intervention strategy for allergy prevention.     

Severe asthma in childhood: assessed in 10 year olds in a birth cohort study

Background:  Limited information is available regarding the prevalence of severe asthma in children. The present study aimed at investigating the prevalence of severe asthma in an urban child population; secondarily evaluating the applicability of the chosen definition by clinical characteristics. Methods:  Children enrolled in the prospective birth cohort; the Environment and Childhood Asthma Study in Oslo; were reinvestigated at the age of 10 years (n = 1019). A representative population based cohort of 616 children [mean age 10.9 (SD 0.9) years] with lung function measurements at birth was used for prevalence estimates, whereas all 1019 children (154 with current asthma) attending the 10‐year follow‐up were included for verification of the definition of severe asthma. Clinical investigations included spirometry, tests of bronchial hyperresponsiveness, skin prick tests and exhaled nitric oxide. Severe asthma was defined as poorly controlled asthma despite treatment with ≥ 800 μg budesonide or equivalent; assessed by a detailed structured interview. Results:  The population point prevalence at age 10 years of current severe asthma was 0.5% (three of 616) and among children with current asthma 4.5% (three of 67). The 10/154 children identified as suffering from severe asthma more often had severe bronchial hyperresponsiveness (PD₂₀ methacholine <1 μmol) (60%vs 22%, P = 0.015), lower median forced expiratory volume in 1 s/forced vital capacity ratio (93%vs 99%, P = 0.04) and higher body mass index (mean BMI 22.3 vs 18.3, P < 0.001) than nonsevere current asthmatics. Conclusions:  The prevalence of severe asthma was 0.5% in all 10‐year olds, and 4.5% among current asthmatics. The severe asthma definition applied in this study is supported by results of clinical investigations.     

TP53 polymorphisms and haplotypes in South Amerindians and neo-Brazilians

To evaluate the genetic diversity of Brazilian populations and contribute to the knowledge of their evolutionary history this study investigated three TP53 polymorphisms (BstUI and MspI RFLPs in exon 4 and intron 6, respectively, and a 16bp duplication in intron 3). The populations studied were: 114 Amerindians from five Brazilian Indian tribes (Gavião, Surui, Zoró, Wai-Wai and Xavante), 95 Euro-Brazilians and 70 Afro-Brazilians. The polymorphisms were all analysed using PCR amplifications. Gene frequencies and haplotype prevalences were calculated using the ARLEQUIN software. The genetic affinities of these groups with other world populations were estimated by the D_A distance and neighbour joining method, using the NJBAFD computer program. Neo-Brazilians (immigrants from Europe and Africa) generally presented more variability than Amerindians, Afro-Brazilians being the most variable population. Among Amerindians, Gavião is the only group polymorphic for the three markers. Wai-Wai showed variability in BstUI and MspI RFLPs, while the other tribes were monomorphic for the 16bp A1 and MspI A2 alleles. A rare haplotype (1-2-1) was verified among the Wai-Wai. This haplotype was previously described in a Chinese sample only, but with low frequency. Therefore, either this combination was lost in the other tribes by genetic drift, recombination, or other factor, or it occurs in the Wai-Wai and Chinese by independent events. The Gavião also presented a haplotype (2-1-1) not observed in the other Amerindians; but since it is present in Euro- and Afro-Brazilians, its occurrence there is probably due to interethnic admixture. The relationships of several world populations obtained using TP53 indicates that this marker is very efficient in clustering populations of the same ethnic group.     

Effects of a mixed‐subsistence diet on the growth of Hadza children

Introduction: We investigated the preliminary effects of dietary changes on the anthropometric measurements of child and adolescent Hadza foragers. Methods: We conducted a cross‐sectional study comparing height and weight of participants (aged 0‐17 years) at two time points, 2005 (n = 195) and 2017 (n = 52), from two locations: semi‐nomadic “bush camps” and sedentary “village camps”. World Health Organization (WHO) calculators were used to generate standardized z‐scores for weight‐for‐height (WHZ), weight‐for‐age (WAZ), height‐for‐age (HAZ), and BMI‐for‐age (BMIFAZ). Cross tabulations were constructed for each measurement variable as a function of z‐score categories and the variables year, location, and sex. Results: Residency in a village, and associated mixed‐subsistence diet, was associated with favorable growth, including greater WAZ (P < .001), HAZ (P < .001), and BMIFAZ (P = .004), but not WHZ (P = .717). Regardless of residency location, participants showed an improved WAZ (P = .021) and HAZ (P < .001) in the 2017 study year. We found no sex differences. Discussion and Conclusion: These preliminary findings suggest that a mixed‐subsistence diet may confer advantages over an exclusive wild food diet, a trend also reported among other transitioning foragers.     

Mercury levels and human health in the Amazon Basin

Abstract

Context: Environmental mercury in the Amazon mostly originates from geochemical sources with some from artisanal gold mining (AGM). Geochemical-originated methylmercury (MeHg) reaches the aquatic food chain, ending up in fish. Inorganic Hg used in AGM is responsible for localised environmental contamination and occupational exposure of adults. In addition to this, iatrogenic ethylmercury (EtHg) derived from Thimerosal-containing vaccines (TCVs) exposes immunised infants.

Objective: To understand Hg exposure in the Amazon in relation to environmental fish-MeHg exposure, occupational AGM activities and low-doses of TCV-EtHg.

Methods: Medline and Thomson-Reuter Web of Science were searched to retrieve and select papers addressing Hg exposure and human health.

Results and conclusion: Environmental-Hg studies addressed health effects associated with birth weight, infant linear growth and neurodevelopment, while, in adults, environmental and occupational studies addressed immune and neurological issues. No widespread clinical toxicity was reported due to fish-MeHg. However, mixed results associated with Hg exposure can be found. Reducing children’s exposure to EtHg is possible using Thimerosal-free vaccines, but it is difficult to interfere with fish consumption without consequences to riverine subsistence populations. Policies to diminish Hg exposure should focus on controlling and/or curbing widespread use of Hg (in gold amalgamation) and promotion of Thimerosal-free vaccines for pregnant women and young children.     

Month‐of‐birth effect on height and weight in Polish rural children

This study investigated a hypothesis of dependence of child height and weight on the month of their birth. The sample comprised 1,241 subjects, 568 boys and 673 girls, age 6–20 years, from villages in Olsztyn Province, Northeast Poland. Individuals' height and weight data were standardized by sex and age to allow grouping of individuals born in the same month irrespective of their sex and age at examination. Subjects born in October to March proved to be significantly taller and heavier than those born in April to September. The magnitude of differences between the semiannual groupings equaled 13.1% of a standard deviation (SD) in height (P = 0.03) and 14.2% of SD in weight (P = 0.02). The month‐of‐birth effect was much stronger for children characterized by high socioeconomic status, where these differences amounted to 39.1% of SD in height (P = 0.02) and 49.4% of SD in weight (P = 0.01). There were no regular changes of the effect with age and no differences between the sexes were found. Fitted cosine functions identified the highest values of examined traits for individuals born in December with the lowest values being found in those born in June. Possible explanations of the month‐of‐birth effect are considered in terms of age categorizing, seasonal variety of growth rates, as well as birth‐related or conception‐related global, hemispheric, and local factors. This study rejects the first two possibilities and suggests this effect requires further research to be conducted in various geographical locations, climates, and cultures, on humans as well as on other species. Am. J. Hum. Biol. 16:31–42, 2004. © 2003 Wiley‐Liss, Inc.     

Synthetic pyrethroid insecticides in fish: Analysis by gas chromatography‐mass spectrometry operated in the negative ion chemical ionization mode and ELISA

Brown trout (Salmo trutta) were captured from a headwater stream contaminated with moth‐proofing agents. Synthetic pyrethroid residues within the tissues were obtained by ultrasonic extraction and examined by gas chromatography‐mass spectrometry operated in the negative ion chemical ionization mode (GC/NCI‐MS). Both permethrin and cyfluthrin had been bioaccumulated by the fish and the mean concentrations ( ± standard deviation) recorded were 2046 ( ± 203) μg kg^‐1 and 25.4 ( ± 46.9) μg kg^‐1 respectively. The concentrations of these pyrethroids are the highest recorded for freshwater fish captured from a natural ecosystem. At the time of sampling, permethrin could be detected within the stream water (0.034 μg l^‐1) while cyfluthrin could not. A mean relative bioconcentration factor of approximately 60 000 was derived for the brown trout which was also greater than any previously determined for freshwater fish. The fish tissue extracts were also analyzed through use of an ELISA for permethrin. The ELISA reported consistently lower concentrations than those obtained by GC/NCI‐MS. This was attributed to analyte losses during preparation of the sample extracts in a form suitable for incorporation into the ELISA. The concentrations obtained by ELISA were significantly correlated with those obtained by GC/NCI‐MS (R² = 0.985, n = 5). Overall, the ELISA appeared to be suitable for the detection of permethrin in fish when present at concentrations in excess of the maximum residue level suggested for many foods by the Commission of the European Economic Community.     

Indoor allergen levels and other environmental risk factors for sensitization in Estonian homes

The prevalence of allergic disease is low in Eastern Europe for reasons that are poorly understood. Our study aimed to investigate the levels of exposure to indoor allergens and living conditions among Estonian infants in relation to sensitization. Dust samples were collected during four winter months in 1993/94 from the homes of 197 infants participating in a prospective study of sensitization. Information about living conditions was collected through home visit and interviewing the mothers when the children were 6 weeks old. Three dust samples were collected from each home: i.e., from the infant's mattress, bedroom floor, and living-room carpet. The levels of allergens were determined by ELISA with monoclonal antibodies. The highest allergen level in a home was regarded as the peak value. The peak geometric mean values (±SD) of Der p 1 and Der f 1 were 0.3 (0.07–1.4) μg/g dust, of Can 1, 0.86 (0.23–3.12) μg/g dust, and of Fel d 1, 0.1 (0.01–0.9) μg/g dust. In 12 homes (9%), the peak value of house-dust mite (HDM) allergens exceeded 2 μg/g dust, with Der p 1 as the dominating allergen. Multivariate analyses indicated that high levels of HDM allergens were more common in apartments that were on the ground floor or first floor, that were heated with stoves, and/or that had a dampness problem. The mean allergen levels at home were similar in children sensitized to HDM (n = 17. 0.29 v.s 0.3 μg/g dust), dog (n=5, 0.55 vs 1.06 μg/g dust, and cat (n= 18, 0.21 vs 0.09 μg/g dust) and in children who were not sensitized to these allergens. Most of the sensitized children were exposed to relatively low allergen levels at home; i.e., below 1 μg/g dust. This level was exceeded in the homes of 4/17 mite-, 5/18 cat-, and 0/5 dog-sensitized children. The similar levels of the major indoor allergens in Estonia and in Scandinavia indicate that the large differences in atopy prevalence among children and young adults in the two regions are not due to differences in allergen exposure. No allergen threshold level for sensitization was identified.     

Rodlet cells and the sensory systems in zebrafish (Danio rerio)

This preliminary work was designed to study, using routine procedures for light and transmission electron microscopy, the presence of rodlet cells (RCs) in or near the sensory systems of 12 adult specimens (4.0 ± 1.2 cm, LT ± SD) of zebrafish, Danio rerio Hamilton, 1822. Rodlet cells, characterized by a distinctive cell cortex (range, 0.4–1.5 μm in thickness) and conspicuous inclusions named “rodlets,” have a round to ovoid nucleus with irregular outline. Mature RCs are 11.5 ± 1.2 μm (mean ± SD) long and 7.8 ± 1.1 μm (mean ± SD) wide. These cells are more numerous near neuromasts enclosed by an epithelial roof and/or ossified canal wall. In contrast, very few RCs were noticed near superficial neuromasts. Based on the presence of RCs around the two cranial neuromasts of each fish, a variable number from 1 to 15 rodlet cells was found (10.4 ± 3.6, mean ± SD). The RCs were located 1.5 μm (minimal) to 73.3 μm (maximal) from the neuromast (27.9 ± 17.2, mean ± SD). Moreover, RCs were found in olfactory epithelium and in proximity to some taste buds. Interestingly, RCs were absent in the inner ear, eye, and brain. Anat Rec, 2007. © 2007 Wiley‐Liss, Inc.     

A randomized,double‐blind,placebo‐controlled,dose‐finding trial with Lolium perenne peptide immunotherapy

Background

A novel subcutaneous allergen immunotherapy formulation (gpASIT+?) containing Lolium perenne peptides (LPP) and having a short up‐dosing phase has been developed to treat grass pollen–induced seasonal allergic rhinoconjunctivitis. We investigated peptide immunotherapy containing the hydrolysate from perennial ryegrass allergens for the optimum dose in terms of clinical efficacy, immunogenicity and safety.

Methods

This prospective, double‐blind, placebo‐controlled, phase IIb, parallel, four‐arm, dose‐finding study randomized 198 grass pollen–allergic adults to receive placebo or cumulative doses of 70, 170 or 370 μg LPP. All patients received weekly subcutaneous injections, with the active treatment groups reaching assigned doses within 2, 3 and 4 weeks, respectively. Efficacy was assessed by comparing conjunctival provocation test (CPT) reactions at baseline, after 4 weeks and after completion. Grass pollen–specific immunoglobulins were analysed before and after treatment.

Results

Conjunctival provocation test (CPT) response thresholds improved from baseline to V7 by at least one concentration step in 51.2% (170 μg; P = .023), 46.3% (370 μg), and 38.6% (70 μg) of patients receiving LPP vs 25.6% of patients receiving placebo (modified per‐protocol set). Also, 39% of patients in the 170‐μg group became nonreactive to CPT vs 18% in the placebo group. Facilitated allergen‐binding assays revealed a highly significant (P < .001) dose‐dependent reduction in IgE allergen binding across all treatment groups (70 μg: 17.1%; 170 μg: 18.8%; 370 μg: 26.4%). Specific IgG₄ levels increased to 1.6‐fold (70 μg), 3.1‐fold (170 μg) and 3.9‐fold (370 μg) (mPP).

Conclusion

Three‐week immunotherapy with 170 μg LPP reduced CPT reactivity significantly and increased protective specific antibodies.

     

Exposure and sensitization to dust mite allergens among asthmatic children in Sao Paulo, Brazil

A group of 20 mite allergic asthmatic children aged 6-12 years old. living in Sao Paulo, Brazil, was studied regarding their degree of sensitization to house dust mites and exposure to mite allergens in their homes. In 18 out of 20 houses at least one dust sample was obtained which contained > 10 μg Der p I/g of dust. The highest levels of Dermatophagoides pteronyssinm allergens, Der p I and Group II, were measured in bedding samples (geometric mean 38.4 and 36.6 μg/g, respectively), followed by bedroom floor, TV room and kitchen. Mite allergen levels in Brazilian houses were as high as those reported to be associated with sensitization and acute attacks of asthma in other parts of the world. In keeping with previous reports that D. farinae is rarely found in Brazil, Der fl was undetectable or found in very low levels (<0.5 μg/g). Levels of cat allergen Pel d I of > 8 μg/g of dust were obtained only in 2 houses only. Cockroach allergen Bia g I was detected in five out of 20 houses. Levels of IgE antibodies to D. pteronyssinus were > 200 RAST U/ml in 19 out of 20 children (geometric mean 1588 RAST U/ml). IgE antibodies to cat, cockroach, A. fumigatus, ragweed and rye grass pollens were undetectable or <80 RAST U/ml. IgE antibodies to the mite Blomia tropicalix were also measured, and levels >200 RAST U/ml were observed in 13 out of 20 sera. Immunoabsorption studies demonstrated that the bulk of the IgE- antibody to B. tropicafis (64%) was to species-specific allergens and that 36% were cross-reactive with D. pteronyssinus. The implication of our results is that management of children with asthma in São Paulo should include skin testing for allergy to both Dermatophagoides and B. tropicalis as well as recommendations about environmental control of house dust mite exposure.     

Dental age assessment for Kuwaiti children using Demirjian's method

Background: Dental age can be estimated based on the level of tooth mineralization during the developmental process. Various methods of determining chronological and radiographical stages have been used for dental age estimation.

Aim: To test the validity of the standards of dental maturation of Demirjian and Goldstein (Ann Hum Biol 3:411–421, 1976) when applied to Kuwaiti children.

Subjects and methods: The sample was selected from healthy Kuwaiti children attending the routine and emergency dental clinics of the Faculty of Dentistry, Kuwait University. Good quality rotational pantomographs were obtained for 509 children (263 girls and 246 boys) between 3 and 14 years. Maturation of the seven permanent teeth on the left side of the mandible was determined according to the crown and root development stages described by Demirjian et al. (Hum Biol 45:211–227, 1973).

Results: There were statistically significant differences in the mean of dental maturation between Kuwaiti and French–Canadian children (p<0.0001). Kuwaiti children were dentally delayed compared to the Canadian standards (mean dental maturation difference of 0.69 year, SD=1.25 years, CI=0.58–0.80). The mean delay in girls was 0.67 year (SD=1.30 years, CI=0.51–0.83) and in boys it was 0.71 year (SD=1.18 years, CI=0.56–0.86). Using a non-linear regression model, function formulae were developed for Kuwaiti girls and boys.

Conclusion: The standards of dental maturation described by Demirjian and Goldstein (1976) may not be suitable for Kuwaiti children.     

5-HT1A, but not 5-HT2 and 5-HT7, receptors in the nucleus raphe magnus modulate hypoxia-induced hyperpnoea

Aim: In the present study, we assessed the role of 5‐hydroxytryptamine (5‐HT) receptors (5‐HT_1A, 5‐HT₂ and 5‐HT₇) in the nucleus raphe magnus (NRM) on the ventilatory and thermoregulatory responses to hypoxia. Methods: To this end, pulmonary ventilation (V_E) and body temperature (T_b) of male Wistar rats were measured in conscious rats, before and after a 0.1 μL microinjection of WAY‐100635 (5‐HT_1A receptor antagonist, 3 μg 0.1μL^?1, 56 mm ), ketanserin (5‐HT₂ receptor antagonist, 2 μg 0.1μL^?1, 36 mm ) and SB269970 (5‐HT₇ receptor antagonist, 4 μg 0.1 μL^?1, 103 mm ) into the NRM, followed by 60 min of severe hypoxia exposure (7% O₂). Results: Intra‐NMR microinjection of vehicle (control rats) or 5‐HT antagonists did not affect V_E or T_b during normoxic conditions. Exposure of rats to 7% O₂ evoked a typical hypoxia‐induced anapyrexia after vehicle microinjections, which was not affected by microinjection of WAY‐100635, SB269970 or ketanserin. The hypoxia‐induced hyperpnoea was not affected by SB269970 and ketanserin intra‐NMR. However, the treatment with WAY‐100635 intra‐NRM attenuated the hypoxia‐induced hyperpnoea. Conclusion: These data suggest that 5‐HT acting on 5‐HT_1A receptors in the NRM increases the hypoxic ventilatory response.     

Nutritional assessment and diet quality of visually impaired Spanish children

Background: The visually impaired represents a fairly numerous group in Spain although no data on their nutritional status has previously been published. Aim: This work aims to assess the nutritional state of a sample of visually impaired children and the quality of their diet. Subjects and methods: The sample comprised 229 boys and girls aged between 8 and 18 years (mean?=?14, SD?=?2.6), all of whom had a visual discapacity and were students of the Centros de Recursos Educativos (CREs; Educational Resources Centres) of the Organización Nacional de Ciegos de España (ONCE; Spanish National Organization for the Blind). Results: This sample featured a high prevalence of overweight (25.8%) and obesity (11.8%) according to the international standard. The mean daily energy consumption and the quantity of carbohydrates, fats, proteins and fibre were greater in boys (2604?kcal?day^?1; 290?g of carbohydrates, 126?g of fats and 90?g of proteins) than in girls (2159?kcal?day^?1, 232?g of carbohydrates, 107?g of fats and 80?g of proteins). No differences in diet intake according to degree of visual impairment were found. Their diet was unbalanced in comparison with the nutritional objectives for the Spanish population, since consumption of carbohydrates was low and that of fats was very high. The results relating to the quality of the diet reveal quite large deviations from the Mediterranean model. Only 11.9% of the whole sample had a value corresponding to a good quality diet. Conclusion: The pattern of dietary consumption was the same as that observed in non visually impaired children in Spain in quantity and quality, nevertheless the prevalence of overweight and obesity is higher than in children without visual handicaps.     

Pesticide (hexachlorocyclohexane) inhibition of growth and nitrogen fixation in blue- green algae Anabaenopsis raciborskii and Anabaena aphanizomenoides

The effects of the pesticide hexachlorocyclohexane (HCH) on the nitrogen fixing blue-green algae Anabaenopsis raciborskii and Anabaena aphanizomenoides commonly found as blooms in fish ponds were studied. These algae were very sensitive to HCH, and a distinct decrease in growth rate was observed on prolonged incubation. Lower concentrations (10 μg/ml) were algistatic and higher concentrations (60 μg/ml) were algicidal. The inhibition of nitrogen fixation indicated that the presence of HCH might affect overall nitrogen economy of inland waters.     

Evaluation of rhBMP‐2 and Natural Latex as Potential Osteogenic Proteins in Critical Size Defects by Histomorphometric Methods

This in vivo study evaluated the osteogenic potential of two proteins, recombinant human bone morphogenetic protein‐2 (rhBMP‐2) and a protein extracted from natural latex (Hevea brasiliensis, P‐1), and compared their effects on bone defects when combined with a carrier or a collagen gelatin. Eighty‐four (84) Wistar rats were divided into two groups, with and without the use of collagen gelatin, and each of these were divided into six treatment groups of seven animals each. The treatment groups were: (1) 5 μg of pure rhBMP‐2; (2) 5 μg of rhBMP‐2/monoolein gel; (3) pure monoolein gel; (4) 5 μg of pure P‐1; (5) 5 μg of P‐1/monoolein gel; (6) critical bone defect control. The animals were anesthetized and a 6 mm diameter critical bone defect was made in the left posterior region of the parietal bone. Animals were submitted to intracardiac perfusion after 4 weeks and the calvaria tissue was removed for histomorphometric analysis. In this experimental study, it was concluded that rhBMP‐2 allowed greater new bone formation than P‐1 protein and this process was more effective when the bone defect was covered with collagen gelatin (P < 0.05). Anat Rec, 2010. © 2010 Wiley‐Liss, Inc.