Vitamin B12 Excretion in Patients with Various Skin Diseases

The excretion in the urine of ⁵⁸Co after an oral dose of ⁵⁸Co vitamin B₁₂ given together with intrinsic factor has been found to be reduced in a number of patients with psoriasis, eczema, and other less common dermatoses. There is a correlation between the abnormality and the extent of the rash. A reduced glomerular filtration rate was found in a few of the patients in whom it was measured, and this must have been responsible, at least in part, for the reduced excretion of vitamin B₁₂ in these patients, but abnormal vitamin B₁₂ excretion also occurred in the absence of impaired renal function. Our evidence is insufficient to show whether malabsorption or increased tissue utilization of vitamin B₁₂ was the explanation in other cases. Certainly a number of patients had steatorrhoea, and in these it is most likely that malabsorption was the major factor. In patients without steatorrhoea a lone malabsorption of vitamin B₁₂ cannot be excluded. A decreased serum concentration of vitamin B₁₂ was found in only one of the patients.     

Patterns of death among avalanche fatalities: a 21-year review

Background

Avalanches are a significant cause of winter recreational fatalities in mountain regions. The purpose of this study was to determine the relative contributions of trauma and asphyxia to avalanche deaths.

Methods

We reviewed all avalanche fatalities between 1984 and 2005 that had been investigated by the offices of the British Columbia Coroners Service and the Chief Medical Examiner of Alberta. In addition, we searched the database of the Canadian Avalanche Centre for fatal avalanche details. We calculated injury severity scores for all victims who underwent autopsy.

Results

There were 204 avalanche fatalities with mortality information over the 21-year study period. Of these, 117 victims underwent autopsy, and 87 underwent forensic external examination. Asphyxia caused 154 (75%) deaths. Trauma caused 48 (24%) deaths, with the rate of death from trauma ranging from 9% (4/44) for snowmobilers to 42% (5/12) for ice climbers. In addition, 13% (12/92) of the asphyxia victims who underwent autopsy had major trauma, defined as an injury severity score of greater than 15. Only 48% (23/48) of victims for whom trauma was the primary cause of death had been completely buried.

Interpretation

Asphyxia and severe trauma caused most avalanche fatalities in western Canada. The relative rates differed between snowmobilers and those engaged in other mountain activities. Our findings should guide recommendations for safety devices, safety measures and resuscitation.Over the past 30 years (1978–2007), avalanches have been responsible for 329 deaths in Canada, with a recent rate of 14 deaths per year.¹ Avalanches kill a disproportionate number of young people, with victims most commonly being in their 20s.^2–5 Outdoor recreation accounts for 92% of avalanche deaths in Canada, and 88% of deaths occur in the provinces of British Columbia and Alberta.¹Mountain rescue agencies emphasize avalanche avoidance strategies but also make recommendations for safety devices and resuscitation techniques.^6,7 One such safety device, an airbag designed to increase flotation and prevent burial, reduced the mortality rate in a European study.⁸ However, the results of that study may not be generalizable to Canada, as it used Swiss and Austrian data, which reflect the European preponderance of avalanche deaths from asphyxia and a reported rate of trauma death of 5.6%.⁹ In contrast, a National Research Council study of human and property loss in Canada reported that trauma was the cause of death in 27% of avalanche deaths in this country.¹⁰ Snowmobilers have become the fastest growing and probably the largest activity group exposed to avalanches in North America,^11–13 yet this activity is not common in Europe. Similarly, so-called helicat skiers, who use helicopters or snowcats (vehicles with an enclosed cab and tracks for travelling on snow) to reach their starting point, are not represented in European statistics.Our purpose was to determine the relative contributions of trauma and asphyxia to avalanche deaths in western Canada and to determine whether this varies between different activity groups.     

CD14 C-159T and early infection with Pseudomonas aeruginosa in children with cystic fibrosis

Early acquisition of Pseudomonas aeruginosa is associated with a poorer prognosis in patients with cystic fibrosis. We investigated whether polymorphisms in CD14, the lipopolysaccharide receptor, increase the risk of early infection. Forty-five children with cystic fibrosis were investigated with annual bronchoalveolar lavage (BAL) and plasma sCD14 levels. Plasma sCD14 levels were significantly lower in children from whom P.aeruginosa was subsequently isolated (492.75 μg/ml vs. 1339.43 μg/ml, p = 0.018). Those with the CD14 -159CC genotype had a significantly increased risk of early infection with P.aeruginosa suggesting that CD14 C-159T plays a role in determining the risk of early infection with P.aeruginosa.     

Fluoride Exposure Aggravates the Testicular Damage and Sperm Quality in Diabetic Mice: Protective Role of Ginseng and Banaba

The current study was conducted to investigate the effects of dietary zinc oxide (ZnO) on the antioxidant capacity, small intestine development, and jejunal gene expression in weaned piglets. Ninety-six 21-day-old piglets were randomly assigned to three dietary treatments. Each treatment had eight replicates with four piglets per replicate. The piglets were fed either control diet (control) or control diet supplemented with in-feed antibiotics (300 mg/kg chlortetracycline and 60 mg/kg colistin sulfate) or pharmacological doses of ZnO (3000 mg/kg). The experiment lasted 4 weeks. Blood samples were collected at days 14 and 28, while intestinal samples were harvested at day 28 of the experiment. Dietary high doses of ZnO supplementation significantly increased the body weight (BW) at day 14 and average daily gain (ADG) of days 1 to 14 in weaned piglets, when compared to control group (P < 0.05). The incidence of diarrhea of piglets fed ZnO-supplemented diets, at either days 1 to 14, days 14 to 28, or the overall experimental period, was significantly decreased in comparison with those in other groups (P < 0.05). Supplementation with ZnO increased the villus height of the duodenum and ileum in weaned piglets and decreased the crypt depth of the duodenum, when compared to the other groups (P < 0.05). Dietary ZnO supplementation decreased the malondialdehyde (MDA) concentration at either day 14 or day 28, but increased total superoxide dismutase (T-SOD) at day 14, when compared to that in the control (P < 0.05). ZnO supplementation upregulated the messenger RNA (mRNA) expression of zonula occludens-1 (ZO-1) and occludin in the jejunum mucosa of weaned piglets, compared to those in the control (P < 0.05). The pro-inflammatory cytokine interleukin-lβ (IL-1β) mRNA expression in the jejunum mucosa was downregulated in the ZnO-supplemented group, compared with the control (P < 0.05). Both in-feed antibiotics and ZnO supplementation decreased the mRNA expression of interferon-γ (IFN-γ), but increased the mRNA expression of transforming growth factor-β (TGF-β), in the jejunum mucosa of piglets, when compared to those in the control (P < 0.05). In summary, supplemental ZnO was effective on the prevention of post-weaning diarrhea (PWD) in weaned piglets and showed comparative growth-promoting effect on in-feed antibiotics, probably by the mechanism of improvement of the antioxidant capacity, restoration of intestinal barrier function and development, and modulation of immune functions.     

Genetically informed ecological niche models improve climate change predictions

We examined the hypothesis that ecological niche models (ENMs) more accurately predict species distributions when they incorporate information on population genetic structure, and concomitantly, local adaptation. Local adaptation is common in species that span a range of environmental gradients (e.g., soils and climate). Moreover, common garden studies have demonstrated a covariance between neutral markers and functional traits associated with a species’ ability to adapt to environmental change. We therefore predicted that genetically distinct populations would respond differently to climate change, resulting in predicted distributions with little overlap. To test whether genetic information improves our ability to predict a species’ niche space, we created genetically informed ecological niche models (gENMs) using Populus fremontii (Salicaceae), a widespread tree species in which prior common garden experiments demonstrate strong evidence for local adaptation. Four major findings emerged: (i) gENMs predicted population occurrences with up to 12‐fold greater accuracy than models without genetic information; (ii) tests of niche similarity revealed that three ecotypes, identified on the basis of neutral genetic markers and locally adapted populations, are associated with differences in climate; (iii) our forecasts indicate that ongoing climate change will likely shift these ecotypes further apart in geographic space, resulting in greater niche divergence; (iv) ecotypes that currently exhibit the largest geographic distribution and niche breadth appear to be buffered the most from climate change. As diverse agents of selection shape genetic variability and structure within species, we argue that gENMs will lead to more accurate predictions of species distributions under climate change.     

Molecular phylogenetics reveal multiple tertiary vicariance origins of the African rain forest trees

Background  

Tropical rain forests are the most diverse terrestrial ecosystems on the planet. How this diversity evolved remains largely unexplained. In Africa, rain forests are situated in two geographically isolated regions: the West-Central Guineo-Congolian region and the coastal and montane regions of East Africa. These regions have strong floristic affinities with each other, suggesting a former connection via an Eocene pan-African rain forest. High levels of endemism observed in both regions have been hypothesized to be the result of either 1) a single break-up followed by a long isolation or 2) multiple fragmentation and reconnection since the Oligocene. To test these hypotheses the evolutionary history of endemic taxa within a rain forest restricted African lineage of the plant family Annonaceae was studied. Molecular phylogenies and divergence dates were estimated using a Bayesian relaxed uncorrelated molecular clock assumption accounting for both calibration and phylogenetic uncertainties.     

Genetic variation in a desert aquatic snail (Nymphophilus minckleyi) from Cuatro Ciénegas, Coahuila, Mexico

The effect of rising salinity levels on freshwater ecosystems is of concern in many parts of the world, including Australia and southern Africa. Most studies on the salinity tolerance of freshwater macroinvertebrates only consider older life-stages, which are suspected of being more tolerant than early life-stages, such as eggs and hatchlings. The salinity tolerances of ten taxa from south-east Australia and two taxa from South Africa, to the artificial seawater, Ocean Nature, were investigated. From the Barwon River in south-west Victoria, the following taxa were tested Amarinus lacustris (Hymenosomatidae), Paratya australiensis (Atyidae) Physa acuta (Physidae), Lymnaeidae, Plectrocnemia sp. (Polycentropodidae), Anisocentropus sp. (Calamoceratidae), Hydrobiosidae, unidentified Polycentropodidae and Dinotoperla thwaitesi (Gripopterygidae). Chironomus tepperi (Chironomidae) from a laboratory colony stocked from central New South Wales was also investigated. The South African limpets Burnupia stenochorias (Ancylidae) were collected in the Eastern Cape and shrimps Caridina nilotica (Atyidae) from a colony stocked from Kwazulu-Natal were studied. The salinity tolerances of the eggs and hatchlings ranged from 0.8 to >47 mS cm^?1 with a mean of 17 mS cm^?1. Where reliable estimates are available, the eggs or hatchlings had a salinity tolerance between 5% and 100% of the 72-hour LC₅₀ of older stages, although for insects this was <50%. This study has thus confirmed that salinity tolerances of young stages can be less than the acute tolerances of older stages.     

Synthesis and SAR of new pyrrolo[2,1-f][1,2,4]triazines as potent p38 alpha MAP kinase inhibitors

A novel series of compounds based on the pyrrolo[2,1-f][1,2,4]triazine ring system have been identified as potent p38 alpha MAP kinase inhibitors. The synthesis, structure-activity relationships (SAR), and in vivo activity of selected analogs from this class of inhibitors are reported. Additional studies based on X-ray co-crystallography have revealed that one of the potent inhibitors from this series binds to the DFG-out conformation of the p38 alpha enzyme.     

Sexual selection favors female-biased sex ratios: the balance between the opposing forces of sex-ratio selection and sexual selection

In a verbal model, Trivers and Willard proposed that, whenever there is sexual selection among males, natural selection should favor mothers that produce sons when in good condition but daughters when in poor condition. The predictions of this model have been the subject of recent debate. We present an explicit population genetic model for the evolution of a maternal-effect gene that biases offspring sex ratio. We show that, like local mate competition, sexual selection favors female-biased sex ratios whenever maternal condition affects the reproductive competitive ability of sons. However, Fisherian sex-ratio selection, which favors a balanced sex ratio, is an opposing force. We show that the evolution of maternal sex-ratio biasing by these opposing selection forces requires a positive covariance across environments between the sex-ratio bias toward sons (b) and the mating success of sons (r). This covariance alone is not a sufficient condition for the evolution of maternal sex-ratio biasing; it must be sufficiently positive to outweigh the opposing sex-ratio selection. To identify the necessary and sufficient conditions, we partition total evolutionary change into three components: (1) maternal sex-ratio bias, (2) sexual selection on sons, and (3) sex-ratio selection. Because the magnitude of the first component asymmetrically affects the strength of the second, biasing broods toward females in a poor environment evolves faster than the same degree of bias toward males in a good environment. Consequently, female-biased sex ratios, rather than male-biased sex ratios, are more likely to evolve. We discuss our findings in the context of the primary sex-ratio biases observed in strongly sexually selected species and indicate how this perspective can assist the experimental study of sex ratio evolution.     

Genomic organization and chromosomal localization of a new repeat MS7, specific for heterochromatin of sex chromosomes in Microtus species voles of the arvalis group

The tandemly arranged MS4 repeat with monomeric units of 4.1 kb is species-specifically distributed in heterochromatin of sex chromosomes of four common vole species of genus Microtus, group arvalis [1, 2]. In this work, we studied the genomic organization of the MS4 homolog in euchromatin of the X chromosome of M. arvalis. It has been shown by analyzing the phage genomic clones that one MS4 copy makes a part of a monomeric unit exceeding 8.5 kb that also includes a new MS7 repeat and, possibly, LINE fragments. MS7 is located together with MS4 in heterochromatin of common vole sex chromosomes, but in a substantially lesser amount. Probably, as a result of an evolutionary transition of an original repeat from euchromatin of the X chromosome to heterochromatin of the Y chromosome, MS4 underwent multiple amplification, and MS7 spread throughout heterochromatin, being surrounded by the MS4 tandem arrays.