Distinct QTLs are linked to cardiac left ventricular mass in a sex-specific manner in a normotensive inbred rat intercross

Genetic mapping of the progeny of an F₂ intercross between WKY and WKHA rats had previously allowed us to detect male-specific linkage between locus Cm24 and left ventricular mass index (LVMI). By further expanding that analysis, we detected additional loci that were all linked to LVMI in a sex-specific manner despite their autosomal location. In males, we detected one additional locus (Lvm8) on Chromosome 5 (LOD = 3.4), the two loci Lvm13 (LOD = 4.5) and Lvm9 (LOD = 2.8) on Chromosome 17, and locus Lvm10 (LOD = 4.2) on Chromosome 12. The locus Lvm13 had the same boundaries as locus Cm26 previously reported by others using a different cross. None of these loci showed linkage to LVM in females. In contrast, we identified in females the novel locus Lvm11 on Chromosome 15 (LOD = 2.8) and locus Lvm12 (LOD = 2.7) that had the same boundaries on Chromosome 3 as locus Cm25 detected previously by others using a cross of other normotensive strains. In prepubertal males, there were no differences in the width of cardiomyocytes from WKY and WKHA rats, but cardiomyocytes from WKHA became progressively wider than that of WKY as sexual maturation progressed. Altogether, these results provide evidence that distinct genes may influence LVMI of rats in a sex-dependent manner, maybe by involving sex-specific interactions of sex steroids with particular genes involved in the determination of LVMI and/or cardiomyocyte width.     

The −112G > A polymorphism of the secretoglobin 3A2 (<Emphasis Type="Italic">SCGB3A2</Emphasis>) gene encoding uteroglobin-related protein 1 (UGRP1) increases risk for the development of Graves’ disease in subsets of patients with elevated levels of immunoglobulin E

The human secretoglobin 3A2 (SCGB3A2) gene encoding secretory uteroglobin-related protein 1 (UGRP1) resides on the chromosome region 5q31-33 that harbors a susceptibility locus to several autoimmune and inflammatory diseases, including asthma and Graves’ disease (GD). Recently, association between the marker rs1368408 (−112G > A), located in the promoter region of the SCGB3A2 gene, and susceptibility to GD was found in Chinese and UK Caucasians. The study aim was to evaluate whether this polymorphism confers GD susceptibility in a large population cohort comprising 1,474 Russian GD patients and 1,619 controls. The marker rs1368408 was studied using a TaqMan allele discrimination assay. Serum levels of UGRP1 and immunoglobulin E (IgE) were assessed using enzyme-linked immunosorbent assay (ELISA) analyses. Association between the allele A of SCGB3A2 and a higher risk of GD (odds ratio [OR] = 1.33, P = 2.9 × 10⁻⁵) was shown. Both affected and non-affected carriers of the higher risk genotype A/A had significantly decreased levels of serum UGRP1 compared to the subjects homozygous for G/G (93 ± 37 pg/ml vs. 132 ± 45 pg/ml, P = 0.0011 for GD patients; 77 ± 28 pg/ml vs. 119 ± 33 pg/ml, P = 0.0019 for controls). Serum IgE levels were significantly higher in non-affected subjects homozygous for A/A compared to control individuals homozygous for G/G (153 ± 46 IU/ml vs. 122 ± 40 IU/ml, P = 0.0095). Our data suggest that the carriage of the SCGB3A2 −112A/A variant increases the risk for GD in subsets of patients with elevated levels of IgE, a hallmark of allergic asthma. Therefore, the SCGB3A2 −112G > A polymorphism may be considered as a likely marker linking susceptibility to allergy/asthma and GD on chromosome 5q31-33.     

Genome-wide linkage and peak-wide association study of obesity-related quantitative traits in Caribbean Hispanics

Although obesity is more prevalent in Hispanics than non-Hispanic whites in the United States, little is known about the genetic etiology of the related traits in this population. To identify genetic loci influencing obesity in non-Mexican Hispanics, we performed a genome-wide linkage scan in 1,390 subjects from 100 Caribbean Hispanic families on six obesity-related quantitative traits: body mass index (BMI), body weight, waist circumference, waist-to-hip ratio, abdominal and average triceps skinfold thickness after adjusting for significant demographic and lifestyle factors. We then carried out an association analysis of the linkage peaks and the FTO gene in an independent community-based Hispanic subcohort (N = 652, 64% Caribbean Hispanics) from the Northern Manhattan Study. Evidence of linkage was strongest on 1q43 with multipoint LOD score of 2.45 (p = 0.0004) for body weight. Suggestive linkage evidence of LOD > 2.0 was also identified on 1q43 for BMI (LOD = 2.03), 14q32 for abdominal skinfold thickness (LOD = 2.17), 16p12 for BMI (LOD = 2.27) and weight (LOD = 2.26), and 16q23–24 for average triceps skinfold thickness (LOD = 2.32). In the association analysis of 6,440 single nucleotide polymorphisms (SNPs) under 1-LOD unit down regions of our linkage peaks on chromosome 1q43 and 16p12 as well as in the FTO gene, we found that two SNPs (rs6665519 and rs669231) on 1q43 and one FTO SNP (rs12447427) were significantly associated with BMI or body weight after adjustment for multiple testing. Our results suggest that in addition to FTO, multiple genetic loci, particularly those on 1q43 region, may contribute to the variations in obesity-related quantitative traits in Caribbean Hispanics.     

MHC class II DRB1 gene polymorphism in the pathogenesis of Maedi–Visna and pulmonary adenocarcinoma viral diseases in sheep

Ovine pulmonary adenocarcinoma (OPA) and Maedi–Visna (Maedi) are two chronic respiratory diseases of retroviral origin which occur worldwide. It is known that different host genetic factors influence the outcome of viral infections. To determine if variation in the Mhc-DRB1 gene was associated with progression to these ovine diseases, sheep lungs with and without OPA and Maedi lesions were collected. A sequence-based method was applied and 40 different alleles were detected in the sample analysed. In the allele-by-allele association analysis, allele DRB1*0325 had a significant association with susceptibility to Maedi (P = 0.045). For OPA, DRB1*0143 and DRB1*0323 were significantly associated with susceptibility (P = 0.024 and P = 0.029), and allele DRB1*0702 was significantly associated with resistance (P = 0.012). Based on these results, the Mhc-DRB1 alleles were classified by effect in three categories—susceptible (S), resistant (R) and neutral (N)—and animals were reassigned the genotypes as S/S, S/R, S/N, R/R, R/N and N/N. In a second analysis, penalised logistic regression models including a flock effect were run. In Maedi, significant association was detected for the N/S heterozygote (P = 0.0007), but not for the S/S homozygote, probably as a result of the low number of S/S animals. In OPA, association was detected for both the S/S and R/R homozygotes (P = 0.005 and P = 0.047). This allele grouping method may be applied in association studies with highly variable genes. This is the first study demonstrating significant associations between sheep Mhc-DRB1 alleles and susceptibility to OPA and Maedi. Therefore, both diseases are suitable candidates for more comprehensive genetic studies.     

Genetic Diversity and Geographical Differentiation of <Emphasis Type="Italic">Desmodium triflorum</Emphasis> (L.) DC. in South China Revealed by AFLP Markers

High levels of genetic variation enable species to adapt to changing environments and provide plant breeders with the raw materials necessary for artificial selection. In the present study, six AFLP primer pairs were used to assess the genetic diversity of Desmodium triflorum (L.) DC. from 12 populations in South China. A high percentage of polymorphic loci (P = 76.16%) and high total gene diversity (H _T = 0.310) were found, indicating that the genetic diversity of D. triflorum is high at the species level. Genetic diversity was also relatively high at the population level (P = 55.85%, H _e = 0.230). The coefficient of gene differentiation among populations (G _ST) was 0.255, indicating that while most genetic diversity resided within populations, there was also considerable differentiation among populations. AMOVA also indicated 24.29% of the total variation to be partitioned among populations (Φ_ST = 0.243). UPGMA clustering analysis based on genetic distances showed that the 12 populations could be separated into three subgroups: an eastern, a western, and a central-southern subgroup. However, a Mantel test revealed no significant correlation (r = 0.286, p = 0.983) between the geographical distances and genetic distances separating these populations; mountain barriers to gene flow and human disturbance may have confounded these correlations. The present study has provided some fundamental genetic data that will be of use in the exploitation of D. triflorum.     

Evidence for novel loci for late-onset Parkinson’s disease in a genetic isolate from the Netherlands

We studied patients with idiopathic Parkinson’s disease (PD) from an isolated population in the Netherlands aiming to map gene(s) involved in PD susceptibility. A total of 109 parkinsonism patients were independently ascertained, of whom 62 presented late-onset, idiopathic PD. Genealogical research showed that 45 index cases with idiopathic PD were linked to a common ancestor, indicating familiar clustering among the patients. This strong familial clustering was highly significant (P=0.005) when compared to random controls from the same population. We performed a genome wide scan using 382 polymorphic markers in 44 distantly related PD patients plus 112 unaffected first-degree relatives and spouses. Our genome wide association analysis (DISLAMB) revealed evidence of association at a nominal P-value<0.01 for markers D2S2333, D4S405, D9S158, D13S153. Other regions on chromosomes 3p, 4q, 14q, 17p and 17q were found at a significance level of P<0.05. In a follow-up study, we investigated all the positive regions using a denser marker set and a larger sample (total of 630 individuals including all late-onset PD patients). The strongest evidence for association remained for the 9q and 14q region. A significant association was found for marker D9S1838 (OR=2.0, 95% CI 1.1–3.5, P=0.014) and D14S65 (OR=3.2, 95% CI 1.7–6.1, P<0.001). Moreover, a common haplotype with excess of sharing among late-onset PD cases was observed on both regions. Our results suggest the existence of two loci influencing PD susceptibility on chromosome 9q and 14q.     

Regulation of adiponectin gene expression in adipose tissue by thyroid hormones

Available experimental data suggest that adiponectin and thyroid hormones have biological interaction in vivo. However, the effects of thyroid hormones on adipose adiponectin gene expression in thyroid dysfunction are unclear. We induced hyper- (HYPER) and hypothyroidism (HYPO) by daily administration of a 12 mg/l of levothyroxine and 250 mg/l of methimazole in drinking water of rats, respectively, for 42 days. The white adipose tissues and serum sample were taken on days 15, 28, 42 and also 2 weeks after treatment cessation. Analysis of adiponectin gene expression was performed by real-time PCR and 2^−ΔΔct method. The levels of adipose tissue adiponectin mRNA in the HYPO rats were decreased during the 6-week treatment when compared to control rats (<0.05) and were increased significantly 2 weeks after HYPO cessation (P < 0.05). This decline in adiponectin gene expression occurred in parallel with a decrease in T3, T4, fT3 and fT4 concentrations (P < 0.05). In opposite to HYPO rats, adipose adiponectin gene expression was increased in HYPER rats during the 6-week treatment in parallel with an increase the thyroid hormones concentrations (P < 0.05), and its expression was decreased 2 weeks after HYPER cessation (P < 0.05). Adiponectin gene expression levels showed significant negative correlations with concentrations of LDL (HYPO; r = −0.806, P = 0.001 and HYPER; r = −0.749, P = 0.002), triglyceride (HYPO; r = −0.825, P = 0.001 and HYPER; r = −0.824, P = 0.001) and significant positive correlations with concentrations of glucose (HYPO; r = 0.674, P = 0.004 and HYPER; r = 0.866, P = 0.001) and HDL (HYPO; r = 0.755, P = 0.001 and HYPER; r = 0.839, P = 0.001). The current study provides evidence that adiponectin gene expression in adipose tissue is regulated by thyroid hormones at the translation level and that lipid and carbohydrate disturbances in a patient with thyroid dysfunction may be, in part, due to adiponectin gene expression changes.     

Ranging behaviour and socio-biology of Eurasian otters (Lutra lutra) on lowland mesotrophic river systems

We examined the spatial structure and socio-biology of a native wild population of Eurasian otters (Lutra lutra) on mesotrophic rivers in a mild temperate climate. Radio-tracking of 20 individuals revealed exclusive intra-sexual adult home-ranges. Adult female home-ranges (7.5 km, SD = 1.5 km, n = 7) were inversely related to river width (, F ₆ = 13.5, P = 0.014) and so appeared to be based on food resources. The aquatic area within adult male home-ranges (30.2 ha, SD = 9.5 ha, n = 5) was greater than that within adult female’s (16.8 ha, SD = 7.0 ha) (t ₁₀ = 2.437, P = 0.035), though this result is inconclusive because some males were tracked on oligotrophic rivers. One adult male expanded its range from 10.2 km to 19.3 km within 5 days of the death of the neighbouring male, suggesting that male home-ranges were heavily influenced by conspecifics.     

Spatial and temporal trends in stable carbon and oxygen isotope ratios of juvenile winter flounder otoliths

Isotopic ratios of fish otoliths have been used in numerous studies as natural tags or markers to aid in the study of connectivity among fish populations. We investigated the use of spatial and temporal changes in the stable carbon and oxygen isotope ratios of otoliths to differentiate juvenile habitats of winter flounder (Pseudopleuronectes americanus). Young-of-the-year (YOY) juvenile winter flounder were collected annually over a three-year period from 18 stations along the coast of Rhode Island, USA. Sagittal otoliths were removed from fish and analyzed for stable carbon (¹³C/¹²C or δ¹³C) and oxygen (¹⁸O/¹⁶O or δ¹⁸O) isotope ratios using continuous flow isotope ratio mass spectrometry. Differences in isotope ratios were observed among stations and along salinity gradients in the Narragansett Bay estuary and an estuarine river system (Narrow River). Overall, the isotope ratio patterns observed among stations were consistent over the three sampling years; however, differences were noted in isotope ratios and the magnitude of the isotope ratio gradients among years. Significant positive correlations were noted between salinity and δ¹³C for two of the three years. For each of the three years sampled there was a highly significant positive correlation (2002, r = 0.93, P < 0.01; 2003, r = 0.85, P < 0.01; 2004, r = 0.97, P < 0.01) between δ¹⁸O and the salinity of the collection site. Also, there was a significant negative correlation between the number of months of above average river flow and δ¹⁸O for the three sampling years (r = 0.99, P < 0.05). These findings suggest that yearly changes in the volume of freshwater inputs to these estuarine habitats may be related to the differences observed in otolith δ¹⁸O isotope ratios. Because of these year-to-year differences, sampling of each cohort may be necessary in order to use this isotopic technique for winter flounder connectivity studies.     

Polymorphism in intron 1 of the interferon-gamma gene influences both serum immunoglobulin E levels and the risk for chronic hepatitis B virus infection in Polynesians

Intron 1 of the interferon-gamma (IFNG) gene contains two polymorphisms. The 12 CA-repeat allele of the +875 IFNGCA microsatellite and the T allele of the +A874T single nucleotide polymorphism (SNP) have been associated with increased in vitro IFNG production and a variety of clinical phenotypes. The purpose of this study was to determine whether these polymorphisms influence total serum IgE levels [tsIgE] and the outcome of a hepatitis B virus (HBV) infection. IFNGCA and +A874T were typed in 186 asthmatics of Niuean ancestry and in Polynesian women with a chronic HBV infection (n = 60) and with natural immunity to the HBV (n = 66). The IFNGCA genotype was associated with [tsIgE] in asthmatic children (n = 51, p = 0.004) but not adults (n = 135, p = 0.87). The data were consistent with a co-dominant influence of the 12 CA-repeat allele on high [tsIgE]. The IFNGCA genotype was also associated with the risk for chronic HBV infection (χ ² = 11.6, p = 0.003) because of a dominant effect of the 12 CA-repeat allele on developing natural immunity in homozygotes (OR = 5.8, p = 0.003) and heterozygotes (OR = 2.7, p = 0.01). Similar associations were found for the T allele of the +A874T SNP. The possibility that these associations were due to linked alleles in the adjacent 783 bp of the promoter and 3′-untranslated region of the IFNG gene was excluded by direct sequencing. In summary, high-IFNG-producing alleles in intron 1 of the IFNG locus are associated with high [tsIgE] in asthmatic children from Niue and with natural immunity to the HBV in Polynesian women. These findings are consistent with a previous report of an association between +875 IFNGCA and [tsIgE] and provide preliminary evidence of a new association with the outcome of an HBV infection.     

Facultative hypothermia as a thermoregulatory strategy in the phyllostomid bats, Carollia perspicillata and Sturnira lilium

The present study questions whether hypothermia is an artifact due to captivity-induced stress or a thermoregulatory strategy for bats of the neotropical family Phyllostomidae. In Guanacaste, Costa Rica, Carollia perspicillata and Sturnira lilium exhibited a bimodal distribution of body temperatures when submitted to an ambient temperature of 21 °C. Body temperature was highly correlated with body mass in both species. C. perspicillata of mass ≥20 g and S. lilium of mass ≥17 g remained normothermic (body temperature >37 °C), whereas at masses below 18 g and 13 g, respectively, >80% of individuals were hypothermic (body temperature ≤32 °C). In two treatment groups for each species, we restricted food intake to ca. 20% of body mass on either night 1 or night 4 following capture. Hypothermia was significantly related to food-restriction, but not time in captivity. Metabolic rate (ml O₂ ·  g⁻¹ h⁻¹) at ambient temperature = 21 °C was MR = e ^{(–2.11 + 0.101 Tb)} (r ² = 0.7, P < 0.001) for C. perspicillata and MR = e ^{(−2.62 + 0.115 Tb)} (r ² = 0.89) for S. lilium. Free-ranging, radio tagged C. perspicillata exhibited daily depression of body temperature to 33–34 °C. We conclude that hypothermia is an thermoregulatory strategy that allows phyllostomid bats to adjust metabolic rate to feeding success and the level of fat stores. Accepted: 20 August 1996     

Trace Minerals Status and Antioxidant Enzymes Activities in Calves with Dermatophytosis

The aim of this study was to determine the levels of trace minerals Zn, Cu, and Se, the effect of dermatophytosis on the level of thiobarbituric acid reactive substances (TBARS) as an indicator of lipid peroxidation, the status of enzymatic and nonenzymatic antioxidants, and the relationship between the mentioned trace minerals and antioxidant defense system in calves with dermatophytosis. A total of 21 Holstein calves with clinically established diagnosis of dermatophytosis and an equal number of healthy ones were included in this study. Results showed that 81% of mycotic isolates were Trichophyton verrucosum, while 19% were Trichophyton mentagrophytes. The level of Zn, Cu, Se, and glutathione (GSH) and the activity of the antioxidant enzymes, glutathione peroxidase (GSH-Px), and superoxide dismutase (SOD) were significantly (P ≤ 0.05) lower. The plasma level of TBARS was significantly (P ≤ 0.05) higher in dermatophytic calves compared to healthy controls. SOD activity was fairly correlated with serum Cu and positively correlated with serum Zn in healthy control (r = 0.68, P ≤ 0.05; r = 0.58, P ≤ 0.05) and in calves affected with dermatophytosis (r = 0.73, P ≤ 0.05; r = 0.55, P ≤ 0.05), respectively. GSH-Px activity was highly correlated with whole blood selenium (r = 0.78, P ≤ 0.05) in healthy control and dermatophytic subjects (r = 0.76, P ≤ 0.05). Our results demonstrated that in dermatophytosis, the alteration in the antioxidant enzyme activities might be secondary to changes in their cofactor concentrations.     

Supplementation with organic or inorganic selenium in heat-distressed quail

The present study was carried out to determine the effects of different sources of selenium (Se; sodium selenite [Na₂SeO₃] or selenomethionine [Se-Met]) supplementation on egg production, egg quality, levels of malondialdehyde (MDA), and Se in serum and egg yolk in heat-stressed Japanese quail (Coturnix coturnix japonica). The birds (n = 360; 55 days old) were randomly assigned to 12 treatment groups consisting of six replicates of five birds each in a 2 × 2 × 3 factorial arrangement of treatments (temperatures, selenium sources, selenium levels). Birds were kept in wire cages in a temperature-controlled room at either 22 (thermoneutral) or 34°C (heat stress) for 8 h/day (09:00–17:00; till the end of study) and fed a basal (control) diet or the basal diet supplemented with either 0.15 or 0.30 mg of Na₂SeO₃ or selenomethionine/kg of diet. Heat exposure decreased live weight, feed intake, feed efficiency, egg production, and egg quality when basal diet was fed (P < 0.0001). A linear increase in feed intake (P = 0.001) and body weight (P = 0.001), egg production (P = 0.001), and improvement in feed efficiency (P = 0.001) and egg quality (P = 0.001) were found in Se-supplemented quail reared under heat stress conditions. Serum, egg white, and egg yolk Se (P ≤ 0.001) concentrations increased linearly, whereas serum, liver, and egg yolk MDA concentrations decreased linearly (P = 0.001) as dietary Na₂SeO₃ or Se-Met supplementation increased. An interaction between dietary Se sources, temperature, and levels of supplementation (P ≤ 0.05) for these parameters was detected. Supplementation with Se improved egg production, egg quality, and antioxidant status of birds, and the effects of Se-Met were relatively greater than Na₂SeO₃ in heat-stressed quail. Results of the present study suggest that supplementation with Se-Met can be considered to be more protective than Na₂SeO₃ by reducing the negative effects of oxidative stress induced by heat stress in quail.     

Angiotensin converting enzyme gene polymorphism is associated with severity of coronary artery disease in men with high total cholesterol levels

This study examines whether renin-angiotensin-aldosterone system gene polymorphisms: ACE (encoding for angiotensin converting enzyme) c.2306-117_404 I/D, AGTR1 (encoding for angiotensin II type-1 receptor) c.1080*86A>C and CYP11B2 (encoding for aldosterone synthase) c.-344C>T are associated with the extension of coronary atherosclerosis in a group of 647 patients who underwent elective coronary angiography. The extension of CAD was evaluated using the Gensini score. The polymorphisms were determined by PCR and RFLP assays. The associations between genotypes and the extent of coronary atherosclerosis were tested by the Kruskal-Wallis test, followed by pairwise comparisons using Wilcoxon test. The population has been divided into groups defined by: sex, smoking habit, past myocardial infarction, BMI (>, ≤ 25), age (>, ≤ 55), diabetes mellitus, level of total cholesterol (>, ≤ 200 mg/dl), LDL cholesterol (>, ≤ 130 mg/dl), HDL cholesterol (>, ≤ 40 mg/dl), triglycerides (>, ≤ 150 mg/dl). Significant associations between the ACE c.2306-117_404 I/D polymorphism and the Gensini score in men with high total cholesterol levels (P_{Kruskal-Wallis} = 0.008; P_adjusted = 0.009), high level of LDL cholesterol (P_{Kruskal-Wallis} = 0.016; P_adjusted = 0.028) and low level of HDL cholesterol (P_{Kruskal-Wallis} = 0.04; P_adjusted = 0.055) have been found. No association between the AGTR1 c.1080*86A>C and CYP11B2 c.-344C>T and the Gensini score has been found. These results suggest that men who carry ACE c.2306-117_404 DD genotype and have high total cholesterol, high LDL cholesterol and low HDL cholesterol levels may be predisposed to the development of more severe CAD.     

Repeated batch cultivation of the microalga Spirulina platensis

Summary The cultivation of photosynthetic microorganisms such as the microalga Spirulina platensis can provide an alternative source of food. The water in Mangueira Lagoon (Rio Grande do Sul state, southern Brazil) has several required nutrients for the growth of Spirulina and could be added to culture medium to reduce the cost of producing S. platensis. Although little studied, repeated batch cultivation is a very useful technique because it has a better cost–benefit ratio than other cultivation methods. In a series of runs, we studied the influence of cell concentration, renewal rate and strain on the specific growth rate and biomass productivity of S. platensis during repeated batch cultivation, the runs taking place in 2-l Erlenmeyer flasks for 2160 h at 30 °C and a light intensity of 2500 lux under a 12 h photoperiod. The three factors studied had a significant (P < 0.05) effect on the results (specific growth rate and productivity). Using Zarrouk’s medium, the highest specific growth rate (μ_X) was 0.111 day⁻¹ while the biomass productivity (P _X) was 0.0423 g l⁻¹ day⁻¹, while Mangueira Lagoon water supplemented with 10% Zarrouk’s medium gave μ_X = 0.113 day⁻¹ and a productivity P _X = 0.0467 g l⁻¹ day⁻¹. These values were two to three times higher than the results obtained in batch cultivation, indicating that the repeated batch cultivation of S. platensis is attractive and convenient.     

Hemoglobin Regeneration Efficiency in Anemic Rats: Effects on Bone Mineral Composition and Biomechanical Properties

This study reports the effects of dietary iron (Fe) deficiency and recovery on bone mineral composition and strength in anemic rats submitted to a hemoglobin (Hb) repletion assay. Weanling male Wistar rats were fed a low-Fe diet (12 mg/kg) for 15 days followed by 2 weeks of Fe repletion with diets providing 35 mg Fe/kg as either ferrous sulfate (n = 8) or ferric pyrophosphate (FP; n = 12). At final day of each period (depletion and repletion), Fe-adequate animals were also euthanized. Iron status (blood Hb, Hb Fe pool, Hb regeneration efficiency), tibia mineral concentrations (Ca, Mg, Fe, Cu, and Zn) and biomechanical properties were evaluated. Iron-deficient rats had lower tibia Fe and Mg levels and bone strength when compared to controls. Yield load and resilience were positively related to tibia Mg levels (r = 0.47, P = 0.02 and r = 0.56, P = 0.004, respectively). Iron repletion did not recover tibia Mg concentrations impaired by Fe deficiency. Moreover, bone elastic properties were negatively affected by FP consumption. In conclusion, bone mineral composition and strength were affected by Fe deficiency, whereas dietary Fe source influenced tibia Mg and resistance in the period during which rats were recovering from anemia.     

Linkage between atopy and the IgE high-affinity receptor gene at 11q13 in atopic dermatitis families

Atopic dermatitis is a common skin disease frequently associated with allergic disorders such as allergic rhinitis and asthma. Controversial linkage findings between atopy and markers at chromosome 11q13 led us to search chromosome 11 for genes conferring susceptibility to atopic dermatitis and atopy. Twelve families were investigated using highly polymorphic markers and a powerful model-free linkage test. Two markers gave evidence for linkage, D11S903 (P = 0.02) and FCER1B (P = 0.005). A two-point lod-score analysis between these two markers revealed significant evidence for linkage (z _max = 4.02 at (θ = 0.0). In regard to model-dependent lod-score analyses between atopic disorders and FCER1B, two-point analysis gave a lod score of z = 0.78 whereas two-locus analysis using a recessive-dominant mode of inheritance displayed a significant lod score of z = 3.55. Only 2 of 12 families showed evidence for linkage using the latter oligogenic model. In conclusion, the results of our study map the FCER1B gene in close proximity to D11S903, support the finding of Cookson et al. implicating the IgE high-affinity receptor gene (FCER1B) at 11q13, and furthermore suggest an oligogenic mode of inheritance as well as heterogeneity in the genetic susceptibility to atopy and atopic dermatitis. Received: 6 November 1995 / Accepted: 1 October 1997     

Trichuris Burdens in Zoo-Housed Colobus guereza

Trichuris spp. infect the majority of captive primate species along with an estimated 1049 million people worldwide, making it an important zoonosis [Stephenson, L. S., Holland, C. V., & Cooper, E. S. Parasitology, 121(Suppl.), S73–S95, 2000]. We investigated the efficacy of methods used to evaluate the prevalence of Trichuris spp. in 2 groups (n = 12) of socially housed Abyssinian colobus (Colobus guereza kikuyensis) at Paignton Zoo Environmental Park and the factors that may affect density. We collected individual and group fecal samples over 6 mo and estimated burden (egg counts/g of feces) of Trichuris spp. via the McMaster technique. Shedding was significantly higher in the afternoon than in the morning (matched-pairs t-test: t _[5] = −4.46, p < 0.01) and in dominant adult male colobus (Spearman rank: r _[5] = −0.94, p < 0.01; age: r _[5] = 0.89, p < 0.05). Parasitological studies of zoo-housed primates can be a useful tool to explore factors that may affect burdens of Trichuris spp. in them.     

Contributions of C3 and C4 plants to higher trophic levels in an Amazonian savanna

We studied the energy flow from C₃ and C₄ plants to higher trophic levels in a central Amazonian savanna by comparing the carbon stable-isotope ratios of potential food plants to the isotope ratios of species of different consumer groups. All C₄ plants encountered in our study area were grasses and all C₃ plants were bushes, shrubs or vines. Differences in δ¹³C ratios among bushes (xˉ = −30.8, SD = 1.2), vines (xˉ = −30.7, SD = 0.46) and trees (xˉ = −29.7, SD = 1.5) were small. However the mean δ¹³C ratio of dicotyledonous plants (xˉ = −30.4, SD = 1.3) was much more negative than that of the most common grasses (xˉ = −13.4, SD = 0.27). The insect primary consumers had δ¹³C ratios which ranged from a mean of −29.5 (SD = 0.47) for the grasshopper Tropidacris collaris to a mean of −14.7 (SD = 0.56) for a termite (Nasutitermes sp.), a range similar to that of the vegetation. However, the common insectivorous and omnivorous vertebrates had intermediate values for δ¹³C, indicating that carbon from different autotrophic sources mixes rapidly as it moves up the food chain. Despite this mixing, the frogs and lizards generally had higher values of δ¹³C (xˉ = −21.7, SD = 1.6; xˉ = −21.9, SD = 1.8, respectively) than the birds (xˉ = −24.8, SD = 1.8) and the only species of mammal resident in the savanna (xˉ = −25.4), indicating that they are generally more dependent on, or more able to utilise, food chains based on C₄ grasses. Received: 7 May 1998 / Accepted: 30 November 1998     

Habitual physical activity and peak anaerobic power in elderly women

The aim of this study was to investigate the relationship between maximal anaerobic power (P _max) and corresponding optimal velocity (V _opt) and habitual physical activity (PA) on the one hand and with maximal oxygen consumption (V˙O_2max) on the other hand, in elderly women. Twenty-nine community dwelling, healthy women aged 66–82 years participated in the study. PA was evaluated using the Questionnaire d'Activite Physique Saint-Etienne (QAPSE) and expressed using two QAPSE activity indices: mean habitual daily energy expenditure (MHDEE) and daily energy expenditure corresponding to leisure time sports activities (sports activity). The subjects' P _max and V _opt were measured while they cycled on a friction-loaded non-isokinetic cycle ergometer. P _max was expressed relative to body mass [P _max/kg(W · kg⁻¹)], and relative to the mass of two quadriceps muscles [P _{max /Quadr}(W·kg_Quadr ⁻¹)]. A negative relationship between P _max/kg (Spearman's r = −0.56; P < 0.01), P _max/Quadr (r = −0.53; P < 0.01) and V _opt (r = −0.45; P < 0.05) and age was found. P _max/kg was positively associated with MHDEE (r = 0.51; P < 0.01) and sports activity (r = 0.58; P < 0.01), as were P _max/Quadr and V _opt (r = 0.55; P < 0.01 and r = 0.54; P < 0.01, respectively). P _max/kg, P _max/Quadr and V _opt correlated positively with V˙O_2max. The positive relationship between ergometer measurements and PA indices was similar to that between V˙O_2max and PA. P _max/kg was, moreover, closely related to V _opt (r = 0.77; P < 0.001). When a multiple stepwise regression analysis was used to select the variables influencing ergometer measurements, MHDEE contributed significantly to P _max/kg variance, whereas sports activity contributed to P _max/Quadr and V _opt variances. In conclusion, the data from this cross-sectional study suggest that in healthy elderly women habitual PA, and especially leisure time PA, alleviates the decline of the P _max of the quadriceps muscles. Accepted: 30 January 1997