Progesterone improves the number and quality of hormone induced Fowler toad (Bufo fowleri) oocytes

Combinations of progesterone, lutenizing hormone releasing hormone analogue (LHRHa), human chorionic gonadotrophin (hCG), and the dopamine-2 (DA2) receptor antagonist 1-[1-[4,4-bis(4-Fluorophenyl)butyl]-4-piperidinyl]-1,3-dihydro-2H-benzimidazol-2-one (Pimozide; Orap) were tested for improvement of spawning rates, oocyte numbers, fertilization and neurulation rates of the Fowler toad (Bufo fowleri). Only treatments combined with progesterone produced large numbers of oocytes. The best treatment on oocyte numbers, neurulation rates, and the number of neurulas was with 5 mg progesterone, 20 mic.g LHRHa, and 0.25 mg Pimozide. Progesterone (5 mg) with 60 mic.g LHRHa gave high spawning rates, oocyte numbers, and fertilization rates but neurulation rates were low. Progesterone alone in high repeated doses did not result in ovulation. High doses of LHRHa (60 mic.g) with hCG, progesterone, and Pimozide gave the greatest number of toads spawning, however, they resulted in low oocyte numbers, fertilization and neurulation rates. A low dose of LHRHa (4 mic.g) with hCG, or hCG alone as a second administration, and progesterone with Pimozide produced few good quality oocytes. Toads were given normal ovulatory doses of hormones 24 or 48 hrs after their initial dose, but these resulted in low oocyte numbers followed by poor fertilization. Overall, these results suggest that progesterone with a dose between 20 mic.g and 60 mic.g of LHRHa may be optimal for the induction of ovulation in these toads. Moreover, Pimozide can supplement low doses of LHRHa but not replace it.     

Concordance between locomotor morphology and foraging mode in lacertid lizards

Foraging behaviors exist along a continuum from highly sedentary, ambush foraging, to more continuous searching, or active foraging. Foraging strategies, or modes, are defined based upon locomotor behaviors (e.g. percent time moving, moves per minute). In lizards, traits correlated with ambush and active foraging have been of interest for some time; however, general patterns of correlated evolution between locomotor morphology and locomotor behavior have only recently begun to be quantified. In this study, variation in hindlimb morphology is investigated in a model group of lizard species that vary between active foraging and more sedentary (or mixed) foraging mode. Canonical variates analysis reveals that the two active foraging species occupy similar regions of the morphospace, while the two more sedentary species occupy different regions. The active foraging species have a narrow pelvis with shorter tibia and femora. The more sedentary species have a wide pelvis, long tibia and femora, and slightly longer metatarsals. Phylogenetic patterns of trait variation were examined through ancestral character state reconstruction and show morphological shifts in concert with foraging mode in these species. The observed shifts in locomotor morphology are discussed in light of published data on sprint speed and endurance in these species. Together, the data show that linking morphological variation to variation in stride length and stride frequency is critical to understanding the evolution of locomotor performance. Much more stride length and frequency data are needed among ambush, mixed, and active foraging species because these parameters, and their morphological components, are likely correlated with variation in food acquisition mode.     

Demography of the Giant Otter (Pteronura brasiliensis) in Manu National Park,South-Eastern Peru: Implications for Conservation

The giant otter (Pteronura brasiliensis) is an endangered semi-aquatic carnivore of South America. We present findings on the demography of a population inhabiting the floodplain of Manu National Park, south-eastern Peru, arising from 14 annual dry season censuses over a 16 year period. The breeding system of territorial groups, including only a single breeding female with non-reproductive adult ‘helpers’, resulted in a low intrinsic rate of increase (0.03) and a slow recovery from decades of hunting for the pelt trade. This is explained by a combination of factors: (1) physiological traits such as late age at first reproduction and long generation time, (2) a high degree of reproductive skew, (3) small litters produced only once a year, and (4) a 50% mortality between den emergence and age of dispersal, as well as high mortality amongst dispersers (especially males). Female and male giant otters show similar traits with respect to average reproductive life-spans (female 5.4 yrs., male 5.2 yrs.) and average cub productivity (female 6.9, male 6.7 cubs per lifetime); the longest reproductive life spans were 11 and 13 years respectively. Individual reproductive success varied substantially and depended mainly on the duration of dominance tenure in the territory. When breeding females died, the reproductive position in the group was usually occupied by sisters or daughters (n = 11), with immigrant male partners. Male philopatry was not observed. The vulnerability of the Manu giant otter population to anthropogenic disturbance emphasises the importance of effective protection of core lake habitats in particular. Riverine forests are the most endangered ecosystem in the Department of Madre de Dios due to the concentration of gold mining, logging and agricultural activities in floodplains, highlighting the need for a giant otter habitat conservation corridor along the Madre de Dios River.     

Oxygen free radicals induced release of lysosomal enzymes in vitro

Summary The effect of oxygen free radicals, generated by xanthine and xanthine oxidase, was studied on the release of lysosomal hydrolase from rat liver lysosomes in vitro. A lysosomal enriched subcellular fraction was prepared, using differential centrifugation technique, from the homogenate of rat liver. The biochemical purity of the lysosomal fraction was established by using the markers of different cellular organelles. Oxygen free radicals were generated in vitro by the addition of xanthine and xanthine oxidase. The release of lysosomal hydrolase (-glucuronidase) from the lysosomal fraction was measured. There was a 3 to 4 fold increase in the release of -glucuronidase activity in the presence of xanthine and xanthine oxidase when compared to that in the absence of xanthine and xanthine oxidase. In the presence of superoxide dismutase (SOD), a scavenger of oxygen free radicals, the xanthine and xanthine oxidase system was unable to induce the release of -glucuronidase activity from the lysosomes. Sonication (2 bursts for 15 sec each) and Lubrol (2 mg/10 mg lysosomal protein) treatment, which are known to cause membrane disruption, also induced the release of -glucuronidase from lysosomal fraction. This release of -glucuronidase by sonication and lubrol treatment was not prevented by SOD. These data indicate that lysosomal disruption is a consequence of oxygen free radicals, generated by xanthine and xanthine oxidase.Abbreviations HEPES N-2-hydroxyethylpiperazine-N-2-ethanesulfonic acid - EGTA Ethylene Glycol Bis-(-aminoethyl ether)N,N,-N,N-tetracetic acid - Tris Tris (hydroxymethyl) aminomethane - SOD Superoxide Dismutase     

Fibroblast growth factor receptor 1-IIIb is dispensable for skin morphogenesis and wound healing

Alternative splicing in the extracellular domain is a characteristic feature of members of the fibroblast growth factor receptor (FGFR) family. This splicing event generates receptor variants, which differ in their ligand binding specificities. A poorly characterized splice variant is FGFR1-IIIb, recently found to be a functional FGF receptor predominantly expressed in the skin. Here we show that FGFR1-IIIb is expressed in normal and wounded mouse skin. Reduced expression of this type of receptor was found in wounds of healing-impaired genetically diabetic mice, suggesting that downregulation of FGFR1-IIIb is associated with wound healing defects. To address this possibility, we deleted the IIIb exon of FGFR1 in mice. The lack of FGFR-IIIb did not alter the expression of either FGFR1-IIIc, other FGF receptor genes or of FGFR1-IIIb ligands in normal and wounded skin. Histological analysis of the skin of FGFR1-IIIb knockout animals did not reveal any obvious abnormalities. Furthermore, full-thickness excisional skin wounds in these mice healed normally and no defects could be observed at the macroscopic or histological level. Finally, several genes that encode key players in wound repair were normally expressed in these animals. These data demonstrate that FGFR1-IIIb is dispensable for skin development and wound repair.     

Seven days of aerobic exercise training improves conduit artery blood flow following glucose ingestion in patients with type 2 diabetes

The vasodilatory effects of insulin account for up to 40% of insulin-mediated glucose disposal; however, insulin-stimulated vasodilation is impaired in individuals with type 2 diabetes, limiting perfusion and delivery of glucose and insulin to target tissues. To determine whether exercise training improves conduit artery blood flow following glucose ingestion, a stimulus for increasing circulating insulin, we assessed femoral blood flow (FBF; Doppler ultrasound) during an oral glucose tolerance test (OGTT; 75 g glucose) in 11 overweight or obese (body mass index, 34 ± 1 kg/m2), sedentary (peak oxygen consumption, 23 ± 1 ml·kg?1·min?1) individuals (53 ± 2 yr) with non-insulin-dependent type 2 diabetes (HbA1c, 6.63 ± 0.18%) before and after 7 days of supervised treadmill and cycling exercise (60 min/day, 60-75% heart rate reserve). Fasting glucose, insulin, and FBF were not significantly different after 7 days of exercise, nor were glucose or insulin responses to the OGTT. However, estimates of whole body insulin sensitivity (Matsuda insulin sensitivity index) increased (P < 0.05). Before exercise training, FBF did not change significantly during the OGTT (1 ± 7, -7 ± 5, 0 ± 6, and 0 ± 5% of fasting FBF at 75, 90, 105, and 120 min, respectively). In contrast, after exercise training, FBF increased by 33 ± 9, 39 ± 14, 34 ± 7, and 48 ± 18% above fasting levels at 75, 90, 105, and 120 min, respectively (P < 0.05 vs. corresponding preexercise time points). Additionally, postprandial glucose responses to a standardized breakfast meal consumed under "free-living" conditions decreased during the final 3 days of exercise (P < 0.05). In conclusion, 7 days of aerobic exercise training improves conduit artery blood flow during an OGTT in individuals with type 2 diabetes.     

A tyrosine-sulfated CCR5-mimetic peptide promotes conformational transitions in the HIV-1 envelope glycoprotein

The HIV-1 envelope glycoprotein is a trimeric complex of heterodimers composed of a surface glycoprotein, gp120, and a transmembrane component, gp41. The association of this complex with CD4 stabilizes the coreceptor-binding site of gp120 and promotes the exposure of the gp41 helical region 1 (HR1). Here, we show that a 15-amino-acid peptide mimetic of the HIV-1 coreceptor CCR5 fused to a dimeric antibody Fc domain (CCR5mim-Ig) bound two gp120 molecules per envelope glycoprotein complex and by itself promoted HR1 exposure. CCR5mim-Ig also stabilized the association of a CD4-mimetic peptide with the envelope glycoprotein. A fusion of the CD4- and CCR5-mimetic peptides, DM1, bound gp120 and neutralized R5, R5X4, and X4 HIV-1 isolates comparably to CD4, and they did so markedly more efficiently than either peptide alone. Our data indicate that the potency of DM1-Ig derives from its avidity for the HIV-1 envelope glycoprotein trimer and from the bidirectional induction of its receptor-mimetic components. DM1 has significant advantages over other inhibitors that target both coreceptor and CD4-binding sites, and it may serve as a lead for a new class of HIV-1 inhibitor peptides.     

Fairness expectations and altruistic sharing in 15-month-old human infants

Human cooperation is a key driving force behind the evolutionary success of our hominin lineage. At the proximate level, biologists and social scientists have identified other-regarding preferences--such as fairness based on egalitarian motives, and altruism--as likely candidates for fostering large-scale cooperation. A critical question concerns the ontogenetic origins of these constituents of cooperative behavior, as well as whether they emerge independently or in an interrelated fashion. The answer to this question will shed light on the interdisciplinary debate regarding the significance of such preferences for explaining how humans become such cooperative beings. We investigated 15-month-old infants' sensitivity to fairness, and their altruistic behavior, assessed via infants' reactions to a third-party resource distribution task, and via a sharing task. Our results challenge current models of the development of fairness and altruism in two ways. First, in contrast to past work suggesting that fairness and altruism may not emerge until early to mid-childhood, 15-month-old infants are sensitive to fairness and can engage in altruistic sharing. Second, infants' degree of sensitivity to fairness as a third-party observer was related to whether they shared toys altruistically or selfishly, indicating that moral evaluations and prosocial behavior are heavily interconnected from early in development. Our results present the first evidence that the roots of a basic sense of fairness and altruism can be found in infancy, and that these other-regarding preferences develop in a parallel and interwoven fashion. These findings support arguments for an evolutionary basis--most likely in dialectical manner including both biological and cultural mechanisms--of human egalitarianism given the rapidly developing nature of other-regarding preferences and their role in the evolution of human-specific forms of cooperation. Future work of this kind will help determine to what extent uniquely human sociality and morality depend on other-regarding preferences emerging early in life.     

Trained immunity: a memory for innate host defense

Immune responses in vertebrates are classically divided into innate and adaptive, with only the latter being able to build up immunological memory. However, although lacking adaptive immune responses, plants and invertebrates are protected against reinfection with pathogens, and invertebrates even display transplant rejection. In mammals, past "forgotten" studies demonstrate cross-protection between infections independently of T and B cells, and more recently memory properties for NK cells and macrophages, prototypical cells of innate immunity, have been described. We now posit that mammalian innate immunity also exhibits an immunological memory of past insults, for which we propose the term "trained immunity." Understanding trained immunity will revolutionize our view of host defense and immunological memory, and could lead to defining a new class of vaccines and immunotherapies.