Dietary and Physical Activity Correlates of Long-Term Weight Loss

Covariations in body mass index (BMI), physical activity, macronutrient intake, and the frequency of consumption of specific foods were examined among 82 men and 75 women participating in a behavioral weight loss program over a period of 18 months. Results of repeated measures analyses of covariance showed that BMI change was inversely related to change in physical activity and change in frequency of vegetable consumption. BMI change was positively related to change in calorie intake from fat and change in frequency of consumption of beef, hot dogs, and sweets. Change in fat calories predicted BMI change better than change in total calories. In addition, change in the frequency of consumption of specific foods accounted for a larger percentage of the variance in BMI change than did change in macronutrients (10.4% vs. 5.2%). No differences were found between predictors of weight loss vs. weight maintenance.     

Dietary and Environmental Correlates of Obesity in a Population Study in China

The patterns and correlates of obesity in China were studied in two panels of a nationwide longitudinal survey conducted in 1989 and 1991 (the China Health and Nutrition Survey). Among the Chinese adults, dietary energy and fat intakes were positively and significantly associated with the Body Mass Index (BMI). Household income and physical activity level were also significantly associated with BMI. Urban residence and higher in come were associated with lower energy intake, higher fat intake, and lower physical activity level compared to rural residence and other income categories. This paper documents an important emerging health problem: the increasing problem of obesity that has been observed in many lower-income countries during the last several decades.     

An Exploration of Molecular Correlates Relevant to Radiation Combined Skin-Burn Trauma

Background

Exposure to high dose radiation in combination with physical injuries such as burn or wound trauma can produce a more harmful set of medical complications requiring specialist interventions. Currently these interventions are unavailable as are the precise biomarkers needed to help both accurately assess and treat such conditions. In the present study, we tried to identify and explore the possible role of serum exosome microRNA (miRNA) signatures as potential biomarkers for radiation combined burn injury (RCBI).

Methodology

Female B6D2F1/J mice were assigned to four experimental groups (n = 6): sham control (SHAM), burn injury (BURN), radiation injury (RI) and combined radiation skin burn injury (CI). We performed serum multiplex cytokine analysis and serum exosome miRNA expression profiling to determine novel miRNA signatures and important biological pathways associated with radiation combined skin-burn trauma.

Principal Findings

Serum cytokines, IL-5 and MCP-1, were significantly induced only in CI mice (p<0.05). From 890 differentially expressed miRNAs identified, microarray analysis showed 47 distinct miRNA seed sequences significantly associated with CI mice compared to SHAM control mice (fold change ≥ 1.2, p<0.05). Furthermore, only two major miRNA seed sequences (miR-690 and miR-223) were validated to be differentially expressed for CI mice specifically (fold change ≥ 1.5, p<0.05).

Conclusions

Serum exosome miRNA signature data of adult mice, following RCBI, provides new insights into the molecular and biochemical pathways associated with radiation combined skin-burn trauma in vivo.     

Communication and Displays of Snakes

With limitations imposed by the lack of appendages and elongatemorphology, snakes exhibit a variety of unique ritualistic behaviorsin the contexts of agonistic encounters and courtship and mating.During male combat rituals, actions involve high vertical displaystances (crotaline) to horizontal stances (colubrid) with eithermale attempting to force the other's head down. Superior positionappears to be important during these encounters. Dominant andsubordinate actions and postures are recognized. Courting snakesexhibit a variety of positions and movements, performed primarilyby the male, which appear to passify the female and induce herreceptivity. Actions involved may be chin rubbing, body jerksor caudocephalic waves, cephalocaudal waves, tail searching,pushing, nudging, biting, and tail raising. Sequences and phasesof the actions used vary with the species. Significant featuresof these behaviors are the different actions taking place separatelyor simultaneously along the elongate cylindrical snake. Visual,tactile, and olfactory communication each play a role.     

A Review of Dietary and Environmental Correlates of Obesity with Emphasis on Developing Countries

The relationships between dietary and environmental factors and obesity are reviewed. Findings from selected population studies of diet and body weight are presented. In general, the results from population studies of diet and obesity have been inconsistent and marked with methodological weaknesses, especially the use of cross-sectional study design. Apart from the diet, several social and economic factors appear to be important correlates of obesity in the population. However, most studies have focused on the socioeconomic status as abroad, composite measure. The relationships between income, education, occupation, place of residence, and obesity are reviewed here, with emphasis on the developing countries. In many developing countries, the changing dietary pattern, along with rising life expectancy and changing socioeconomic environment, has contributed to the increasing problems of obesity and other diet-related chronic diseases that will have an enormous impact on the health and health care resource of these countries in the near future.     

Tracing the Origin of Dietary Protein in Tropical Dry Forest Birds1

Fundamental to our understanding of the ecology of animal communities in the tropics is knowledge of the effect of seasonal changes in the abundance of food sources in consumer diets. We determined stable‐isotope composition (¹³C/¹²C and ¹⁵N/¹⁴N) in whole blood of 14 resident avian species in a tropical dry forest to quantify the origin of their assimilated protein. We used a probabilistic approach (IsoSource) to estimate the relative contribution of C₃ plants, CAM‐C₄ plants, C₃ insects, and CAM‐C₄ insects during the dry and rainy seasons. IsoSource iteratively creates each possible combination of source contribution and produces a distribution of all feasible combinations that adequately predict the observed isotopic signature of the consumer. Granivore–frugivores and granivore–frugivore–insectivores were modeled as predominantly dependent upon plants whereas insectivorous birds were modeled to derive protein almost exclusively from insects. Between these extremes there were several species using mixed diets such as insectivore–frugivores or insectivore–granivores. In most species, virtually all assimilated food was of C₃ origin with the exception of Ruddy Ground‐Doves (Columbina talpacoti) in which CAM or C₄ plants contributed significantly. Seasonal changes in relative food source contribution were followed in eight species of birds. Of these species, White‐tipped Doves (Leptotila verreauxi), Grayish Saltators (Saltator coerulescens), and Social Flycatchers (Myiozetetes similis) increased their use of insects in the rainy season, in contrast to Great Kiskadees (Pitangus sulphuratus), which decreased their use of insects. Our study suggests that that diverse strategies are used by various avian species to obtain dietary proteins within seasonal habitats.     

The Origin and Early Radiation of Archosauriforms: Integrating the Skeletal and Footprint Record

We present a holistic approach to the study of early archosauriform evolution by integrating body and track records. The ichnological record supports a Late Permian–Early Triassic radiation of archosauriforms not well documented by skeletal material, and new footprints from the Upper Permian of the southern Alps (Italy) provide evidence for a diversity not yet sampled by body fossils. The integrative study of body fossil and footprint data supports the hypothesis that archosauriforms had already undergone substantial taxonomic diversification by the Late Permian and that by the Early Triassic archosauromorphs attained a broad geographical distribution over most parts of Pangea. Analysis of body size, as deduced from track size, suggests that archosauriform average body size did not change significantly from the Late Permian to the Early Triassic. A survey of facies yielding both skeletal and track record indicate an ecological preference for inland fluvial (lacustrine) environments for early archosauromorphs. Finally, although more data is needed, Late Permian chirotheriid imprints suggest a shift from sprawling to erect posture in archosauriforms before the end-Permian mass extinction event. We highlight the importance of approaching palaeobiological questions by using all available sources of data, specifically through integrating the body and track fossil record.     

Specializations of the Body Form and Food Habits of Snakes

Viperid snakes have stouter bodies, larger heads, and longerjaws than snakes in other families; there are no major differencesbetween the two subfamilies of vipers in these features. A suiteof morphological characters that facilitates swallowing largeprey finds its greatest expression among vipers, but certainelapid and colubrid snakes have converged upon the same bodyform. The number of jaw movements required to swallow prey islinearly related to the size of a prey item when shape is heldconstant. Very small and very large prey are not disproportionatelydifficult for a snake to ingest. Vipers swallow their prey withfewer jaw movements than do colubrids or boids and can swallowprey that is nearly three times larger in relation to theirown size. Proteolytic venom assists in digestion of prey, andmelanin deposits shield the venom glands from light that woulddegrade the venom stores. Ancillary effects of the morphologicalfeatures of vipers, plus the ability to ingest a very largequantity of food in one meal, should produce quantitative andqualitative differences in the ecology and behavior of vipersand other snakes.     

Pattern and Instability in the Evolving Premaxilla of Boine Snakes

Morphological evidence indicates that within the snake familyBoidae the subfamily Pythoninae is ancestral to the Boinae.The python-boa transition in evolution involves a peculiar rotationof the premaxillary bone. During rotation the ventral processof the premaxilla, the processus palatini, is largely obliteratedbut reconstituted in later Boinae. There exist indications thatthe pattern of the processus palatini is less controlled orstable in boine snakes than in pythonines. Pattern instabilitycan be the result of several factors which include relaxed selectionfor precise form and a disruption in the developmental foundationof the feature which has not fully been reversed. These possiblefactors, though fundamentally different, need not exclude eachother. It is surmised that the pattern instability in boinesis related, at least in part, to the disruption of a morphogeneticparadigm affecting premaxillary shape.     

The Cochlear Duct of Lizards and Snakes

The gross morphology of the cochlear ducts of approximatelyhalf (150) of the living genera of lizards and a third (130)of the living genera of snakes have been studied. The differencesin the structure of the cochlear duct are related to both theacoustical capacities and the taxonomic relationships of certainlizards and snakes. The cochlear duct of lizards consists offairly well joined lagenar and limbic portions. By contrast,the cochlear duct of snakes consists of a lagenar sac somewhatconstricted from the limbus. Each family of lizards has a morphologicallycharacteristic cochlear duct, but taxonomic relationships areindicated by certain anatomical similarities. The cochlear ductof snakes is more primitive than that of lizards, and, unlikelizards, does not exhibit marked specializations of its variousparts. Differences in morphology of the cochlear duct in snakesare much more related to habitat than family. The limbus andpapilla basilaris of snakes regardless of family, are most elongatedin bin rowing species, are only moderately elongated or ovoidin terrestrial species, and are small or reduced in certainarboreal and aquatic species.     

Human Genetic Ancestral Composition Correlates with the Origin of Mycobacterium leprae Strains in a Leprosy Endemic Population

Recent reports have suggested that leprosy originated in Africa, extended to Asia and Europe, and arrived in the Americas during European colonization and the African slave trade. Due to colonization, the contemporary Colombian population is an admixture of Native-American, European and African ancestries. Because microorganisms are known to accompany humans during migrations, patterns of human migration can be traced by examining genomic changes in associated microbes. The current study analyzed 118 leprosy cases and 116 unrelated controls from two Colombian regions endemic for leprosy (Atlantic and Andean) in order to determine possible associations of leprosy with patient ancestral background (determined using 36 ancestry informative markers), Mycobacterium leprae genotype and/or patient geographical origin. We found significant differences between ancestral genetic composition. European components were predominant in Andean populations. In contrast, African components were higher in the Atlantic region. M. leprae genotypes were then analyzed for cluster associations and compared with the ancestral composition of leprosy patients. Two M. leprae principal clusters were found: haplotypes C54 and T45. Haplotype C54 associated with African origin and was more frequent in patients from the Atlantic region with a high African component. In contrast, haplotype T45 associated with European origin and was more frequent in Andean patients with a higher European component. These results suggest that the human and M. leprae genomes have co-existed since the African and European origins of the disease, with leprosy ultimately arriving in Colombia during colonization. Distinct M. leprae strains followed European and African settlement in the country and can be detected in contemporary Colombian populations.     

Mineralized Tissues and Exercise Physiology of Snakes

Previous studies indicate a tight correlation of predatory modes,morphology, and activity physiology in snakes. Active foragerslike the coachwhip (Masticophis flagellum) exhibit great staminaand high rates of aerobiosis and anaerobiosis during intenseexercise. The western rattlesnake (Crotalus viridis), a sit-and-waitpredator, is capable of bouts of intense activity for limitedperiods of time before exhaustion. During maximal activity therattlesnake has moderate powers of anaerobiosis and limitedpowers of aerobiosis. Superior blood buffering capacity in thecoachwhip seems at least partially responsible for its stamina.New evidence presented here indicates that low endurance inthe rattlesnake may be associated with exercise-related bonedissolution, resulting in hypercalcemia. Such hypercalcemiamay function to further debilitate the already poorly developedblood buffering capacity of the rattlesnake.     

钝头蛇类系统学研究进展

钝头蛇类不同类群在外形、色斑及鳞被特征上有很高的相似度,关于其种属划分长期以来一直存在争议。本文根据已有文献资料及笔者自己的研究成果,主要从形态学和分子系统学方面叙述了钝头蛇类分类学的研究进展,从属以上、属级以及种级分类阶元叙述其研究历史及成果,主要进展如下:1整个亚洲食螺蛇类(钝头蛇类)构成一个科,即钝头蛇科(Pareatidae),而非隶属于游蛇科(Colubridae)的钝头蛇亚科(Pareatinae);2单楯蛇属(Aplopeltura)和弱钝头蛇属(Asthenodipsas)为有效属,最大的钝头蛇属(Pareas)理论上可进一步分为两个属,但需要更充分的分子系统学与形态学资料验证;3分子系统学研究结果提示台湾钝头蛇(P.formosensis)与中国钝头蛇(P.chinensis)不构成单系,应恢复后者的有效性;4综合分类学研究恢复了Asthenodipsas tropidonotus的有效性,并设立新种A.lasgalenensis。本文同时提出了钝头蛇类分类学研究中存在的主要问题,即中国钝头蛇种组(Pareas chinensis species group)的内部分类关系需进一步厘定。     

Dietary Pectin Increases Intestinal Crypt Stem Cell Survival following Radiation Injury

Gastrointestinal (GI) mucosal damage is a devastating adverse effect of radiation therapy. We have recently reported that expression of Dclk1, a Tuft cell and tumor stem cell (TSC) marker, 24h after high dose total-body gamma-IR (TBI) can be used as a surrogate marker for crypt survival. Dietary pectin has been demonstrated to possess chemopreventive properties, whereas its radioprotective property has not been studied. The aim of this study was to determine the effects of dietary pectin on ionizing radiation (IR)-induced intestinal stem cell (ISC) deletion, crypt and overall survival following lethal TBI. C57BL/6 mice received a 6% pectin diet and 0.5% pectin drinking water (pre-IR mice received pectin one week before TBI until death; post-IR mice received pectin after TBI until death). Animals were exposed to TBI (14 Gy) and euthanized at 24 and 84h post-IR to assess ISC deletion and crypt survival respectively. Animals were also subjected to overall survival studies following TBI. In pre-IR treatment group, we observed a three-fold increase in ISC/crypt survival, a two-fold increase in Dclk1+ stem cells, increased overall survival (median 10d vs. 7d), and increased expression of Dclk1, Msi1, Lgr5, Bmi1, and Notch1 (in small intestine) post-TBI in pectin treated mice compared to controls. We also observed increased survival of mice treated with pectin (post-IR) compared to controls. Dietary pectin is a radioprotective agent; prevents IR-induced deletion of potential reserve ISCs; facilitates crypt regeneration; and ultimately promotes overall survival. Given the anti-cancer activity of pectin, our data support a potential role for dietary pectin as an agent that can be administered to patients receiving radiation therapy to protect against radiation-induces mucositis.