Climate and prevalence of atopic eczema in 6- to 7-year-old school children in Spain. ISAAC PhASE III

Atopic eczema (AE) is a chronic skin disease. Recent reports indicate that the worldwide prevalence of AE is increasing and that various environmental factors are implicated in its aetiology. Climatic conditions have been related with AE prevalence, and Spain has varying climatic conditions. The aim of this study is to document the possible climatic influence on the prevalence of AE in schoolchildren aged 6–7 years in three different climatic regions in Spain. We conducted a cross-sectional population-based survey of 28,394 schoolchildren aged 6–7 years from 10 Spanish centres in three different climatic regions. The mean participation rate was 76.5%. AE prevalence was assessed using the International Study of Asthma and Allergies in Childhood (ISAAC) questionnaire and the Spanish Academy of Dermatology criteria used in Spain to diagnose AE. The data, including annual temperature, precipitation, relative humidity and the annual number of sunny hours per climatic region, were obtained from the Spanish National Institute of Meteorology. Different AE prevalences were found in all three climatic regions studied: Atlantic, 32.9; Mediterranean 28.3; and Continental 31.2 per 100 children studied (p < 0.005). AE was positively associated with precipitation and humidity, and was negatively associated with temperature and the number of sunny hours. The results show that AE is significantly dependent on meteorological conditions.     

Rapid dispersal and establishment of a benthic Ponto-Caspian goby in Lake Erie: diel vertical migration of early juvenile round goby

The round goby, Apollonia melanostoma, a molluscivore specialist, was introduced to the Great Lakes in the early 1990s and rapidly expanded its distribution, especially in Lake Erie. Adult round goby morphology suggests low dispersal and migration potential due to the lack of a swim bladder and benthic life style. Given that the larval stage occurs inside the benthic egg, and juveniles have adult morphologies, it has been suspected that dispersal and invasion potential is low for early life stages also. However, we identified early juvenile round gobies in the nocturnal pelagic in Lake Erie and thus we conducted a sampling study to determine the extent to which this life stage uses the nocturnal pelagic. Replicate ichthyoplankton samples were collected at 3-h intervals (1900–0700 h) at three depths (2 m, 5 m, 8 m) in western Lake Erie (water depth = 10 m) in July and August 2002 and June 2006. Early juvenile round gobies (6–23 mm TL) were present almost exclusively in the nocturnal samples (2200 h, 0100 h, 0400 h) with peak densities approaching 60 individuals per 100 m³ of water sampled. Nocturnal density was also significantly greater at 8-m depth versus 2-m and only the smallest fish (6–8 mm TL) migrated to the surface (2-m). Analyses of diet clearly demonstrated that these fish are foraging on plankton at night and thus may not be light limited for foraging in ship ballast tanks. In ships that take on thousands of tonnes of water for ballast, nocturnal ballasting could easily result in transport of thousands of young round gobies at a time. Additionally, within-lake dispersal at this lifestage is likely common and may facilitate downstream passage across barriers designed to limit range expansion.     

The Pax3-Cre transgene exhibits a rostrocaudal gradient of expression in the skeletal muscle lineage

Pax3-Cre (P3Pro-Cre) transgenic mice have been used for conditional gene deletion and/or lineage tracing in derivatives of neural crest, neural tube, metanephric mesenchyme, and ureteric mesenchyme. However, the extent of its expression in skeletal muscle has not been reported. We investigated the expression of P3Pro-Cre in the skeletal muscle lineage using the R26R reporter and found an unexpected rostrocaudal gradient of expression. By X-gal staining, head, neck, forelimb, diaphragm, and most of the chest wall muscles did not show evidence of Cre expression, whereas all muscle groups posterior of the diaphragm stained blue. Intercostal muscles exhibited a rostrocaudal gradient of staining. The consistency of this expression pattern was demonstrated by using P3Pro-Cre to mutate a conditional dystroglycan allele. The result was loss of dystroglycan from caudal muscles, which exhibited the histological signs of muscle fiber injury and regeneration characteristic of muscular dystrophy. The lack of dystroglycan in regenerating myofibers suggests that the P3Pro-Cre transgene is active in satellite cells and/or in their precursors. In contrast, rostral muscles, including feeding and breathing muscles, maintained dystroglycan expression and were spared from disease. Accordingly, the mutants were viable for over a year. Its unique gradient of activity makes the P3Pro-Cre transgene a previously unappreciated yet powerful tool for manipulating gene expression in skeletal muscle and its precursors.     

Erectile Dysfunction and Essential Hypertension: The Same Aging-related Disorder?

An erection is a mechanical event dependent primarily on corporeal vascular dynamics wherein arterial inflow and storage of blood within the corpora is greater than the egress of blood from the corpora. The most common cause of erectile dysfunction (ED) is the inability of the corporal tissue to store the blood within the corporal sinusoids once inflow into the corpora begins. This failure to store is primarily due to a corporal smooth muscle dysfunction and, in most men, is most likely an aging-related occurrence. Because the corporal smooth muscle is embryologically and physiologically indistinguishable from the smooth muscle within our arterial system, the authors hypothesize that the aging-related dysfunction that occurs within the penis also occurs within the arterial system, and that this smooth muscle dysfunction within the arterial media is most likely the cause of what is called essential hypertension. This panvascular smooth muscle myopathy could explain why hypertension is the most common comorbidity associated with ED and appears to indicate that both ED and essential hypertension are the same disorder, albeit in two different organ systems.Key words: Erection, Endothelium, Smooth muscle, HypertensionAlmost all men recognize at some time in their lives that their erectile function begins to change. For most men, the ability to attain and maintain an erection during the teenage years is second nature. However, by the time men hit the fourth and fifth decade of life, many have recognized that their erectile function has changed, and the ability to maintain an erection during sex has diminished; the refractory period, the time in between erectile events, begins to increase. Although men in their teenage years and young adult lives are able to have multiple erectile events at will, this ability begins to fade as aging sets in. Because the ability to maintain an erection is directly related to the function of the corporal smooth muscle, this increase in the refractory period is a clinical sign that the smooth muscle of the corpora is likely becoming dysfunctional. This review highlights what we know about the corporal smooth muscle cell and demonstrates that what occurs to the corporal smooth muscle cell also occurs to its embryologic sibling, the smooth muscle cell within the media of the peripheral vascular system. As a result of this relationship, changes in the function of the penis can reflect changes in the vascular system.     

The effects of stanozolol and boldenone undecylenate on scrotal width, testis weight, and sperm production in pony stallions

Fifty mature pony stallions were randomly assigned to one of five treatment groups: Group 1- controls (no treatment), Group 2 - 0.55 mg/kg stanozolol weekly for 13 treatments, Group 3 - 1.1 mg/kg stanozolol every 3 weeks for 5 treatments, Group 4 - 1.1 mg/kg boldenone undecylenate every 3 weeks for 5 treatments, and Group 5 - 0.55 mg/kg boldenone undecylenate weekly for 13 treatments. Scrotal widths (SW), combined testis weights (CTW), and daily sperm productions (DSP) were not different between Groups 1 and 2. Ponies in Group 5 had smaller SW (P<0.01), smaller CTW and decreased DSP compared to controls (P < 0.05). Although SW for ponies in Groups 3 and 4 were less than for controls (P < 0.01), CTW and DSP were not different. The only treatment regime that did not alter SW, CTW, and DSP was Group 2 (0.55 mg/kg stanozolol weekly for 13 treatments).     

Declines in sociosexual behavior in golden monkeys (Rhinopithecus roxellana): Associated environmental and social variables

Between February 22 and August 10, 1986, 200 h of systematic observation were conducted on a male and female golden monkey (Rhinopithecus roxellana) at Seattle's Woodland Park Zoo and Portland's Washington Park Zoo. The pair was moved to Portland on May 6, and on July 24 the female unexpectedly gave birth to a male infant, the first such birth in the United States. Dramatic behavioral changes occurred immediately after the pair was moved to Portland, the midpoint of the female's pregnancy, including the disappearance of sexual behavior and a sharp decline in time spent in contact. Explanations for these changes are discussed.     

Sex difference in travel is concentrated in adolescence and tracks reproductive interests

Sexual selection theory suggests that the sex with a higher potential reproductive rate will compete more strongly for access to mates. Stronger intra-sexual competition for mates may explain why males travel more extensively than females in many terrestrial vertebrates. A male-bias in lifetime distance travelled is a purported human universal, although this claim is based primarily on anecdotes. Following sexual maturity, motivation to travel outside the natal territory may vary over the life course for both sexes. Here, we test whether travel behaviour among Tsimane forager–horticulturalists is associated with shifting reproductive priorities across the lifespan. Using structured interviews, we find that sex differences in travel peak during adolescence when men and women are most intensively searching for mates. Among married adults, we find that greater offspring dependency load is associated with reduced travel among women, but not men. Married men are more likely to travel alone than women, but only to the nearest market town and not to other Tsimane villages. We conclude that men''s and women''s travel behaviour reflects differential gains from mate search and parenting across the life course.     

Laminin alpha5 is required for dental epithelium growth and polarity and the development of tooth bud and shape

In tooth development, the oral ectoderm and mesenchyme coordinately and reciprocally interact through the basement membrane for their growth and differentiation to form the proper shape and size of the tooth. Laminin alpha5 subunit-containing laminin-10/11 (LM-511/521) is the major laminin in the tooth germ basement membrane. Here, we have examined the role of laminin alpha5 (Lama5) in tooth development using laminin alpha5-null mouse primary dental epithelium and tooth germ organ cultures. Lama5-null mice develop a small tooth germ with defective cusp formation and have reduced proliferation of dental epithelium. Also, cell polarity and formation of the monolayer of the inner dental epithelium are disturbed. The enamel knot, a signaling center for tooth germ development, is defective, and there is a significant reduction of Shh and Fgf4 expression in the dental epithelium. In the absence of laminin alpha5, the basement membrane in the inner dental epithelium becomes discontinuous. In normal mice, integrin alpha6beta4, a receptor for laminin alpha5, is strongly localized at the basal layer of the epithelium, whereas in mutant mice, integrin alpha6beta4 is expressed around the cell surface. In primary dental epithelium culture, laminin-10/11 promotes cell growth, spreading, and filopodia-like microspike formation. This promotion is inhibited by anti-integrin alpha6 and beta4 antibodies and by phosphatidylinositol 3-kinase inhibitors and dominant negative Rho-GTPase family proteins Cdc42 and Rac. In organ culture, anti-integrin alpha6 antibody and wortmannin reduce tooth germ size and shape. Our studies demonstrate that laminin alpha5 is required for the proliferation and polarity of basal epithelial cells and suggest that the interaction between laminin-10/11-integrin alpha6beta4 and the phosphatidylinositol 3-kinase-Cdc42/Rac pathways play an important role in determining the size and shape of tooth germ.     

Fatty acid transport protein 4 is dispensable for intestinal lipid absorption in mice

FA transport protein 4 (FATP4), one member of a multigene family of FA transporters, was proposed as a major FA transporter in intestinal lipid absorption. Due to the fact that Fatp4(-/-) mice die because of a perinatal skin defect, we rescued the skin phenotype using an FATP4 transgene driven by a keratinocyte-specific promoter (Fatp4(-/-);Ivl-Fatp4(tg/+) mice) to elucidate the role of intestinal FATP4 in dietary lipid absorption. Fatp4(-/-);Ivl-Fatp4(tg/+) mice and wild-type littermates displayed indistinguishable food consumption, growth, and weight gain on either low or high fat (Western) diets, with no differences in intestinal triglyceride (TG) absorption or fecal fat losses. Cholesterol absorption and intestinal TG absorption kinetics were indistinguishable between the genotypes, although Western diet fed Fatp4(-/-);Ivl-Fatp4(tg/+) mice showed a significant increase in enterocyte TG and FA content. There was no compensatory upregulation of other FATP family members or any other FA or cholesterol transporters in Fatp4(-/-);Ivl-Fatp4(tg/+) mice. Furthermore, although serum cholesterol levels were lower in Fatp4(-/-);Ivl-Fatp4(tg/+) mice, there was no difference in hepatic VLDL secretion in-vivo or in hepatic lipid content on either a chow or Western diet. Taken together, our studies find no evidence for a physiological role of intestinal FATP4 in dietary lipid absorption in mice.     

Should I stay or should I go: predator- and conspecific-induced hatching in a marine snail

Predator-induced hatching plasticity has been demonstrated in many species of amphibians. However, animals from other clades (e.g., marine species of molluscs and annelids) also place their embryos in capsules or gelatinous masses and might also exhibit hatching plasticity to predators. To date there is no evidence of predator-induced hatching plasticity from any marine species or a major clade of bilateria animals, the Lophotrochozoa. We studied predator-induced hatching plasticity of Nucella lamellosa, a carnivorous marine snail that deposits embryos in capsules. We used two experiments to investigate the effects of two types of predator, crabs and isopods, on developing embryos. In the first experiment, we quantified proportion of hatched embryos from capsules through time exposed to water-borne chemicals of crabs and isopods. Crabs delayed time-to-hatching, and the effects of predators were additive. In the second experiment, we quantified proportion of hatched embryos from capsules through time, developmental stage, and size of embryos in capsules exposed to water-borne chemicals of crabs and conspecifics. With this experiment, we wanted to answer: (1) whether a delay in hatching corresponded to embryos developing slower, and (2) whether the general products of metabolic waste from organisms can delay hatching. We unexpectedly observed that adult conspecific snails accelerated hatching but not developmental rate—the few past studies on the effects of conspecifics have all demonstrated that conspecifics delay time-to-hatching and rate of development. The results were also inconsistent with metabolic waste in general causing a delay in hatching, although the effect of conspecifics does weaken this inference. This study demonstrates that predators delay time-to-hatching in a marine mollusc, and suggests that predator-induced hatching plasticity is widespread among animals and likely evolved multiple times within the bilateria. In addition, conspecifics accelerated time-to-hatching in a marine mollusc, which suggests that conspecifics, like predators, might commonly influence when embryos hatch.