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Human Males (human + male)
Selected AbstractsAdipogenic Effect of Alcohol on Human Bone Marrow-Derived Mesenchymal Stem CellsALCOHOLISM, Issue 7 2004Frederick H. Wezeman Background: In addition to a decrease in bone mass in alcoholics their osteopenic skeletons show an increase in bone marrow adiposity. Human bone marrow mesenchymal stem cells (hMSC) in vivo differentiate into several phenotypes including osteogenic and adipogenic cells, both of which remain as resident populations of bone marrow. In vitro, the lineage commitment and differentiation of hMSC toward the adipogenic pathway can be promoted by alcohol. Methods: Human male and female mesenchymal stem cells from joint replacement surgery were cultured. Cells were grouped as: 1) Control (no additions to the culture medium), 2) EtOH (50 mm alcohol added to the culture medium), 3) OS (osteogenic inducers added to the culture medium), and 4) OS + EtOH (osteogenic inducers and 50 mm alcohol added to the culture medium). Cultures stained with Nile Red confirmed the development of differentiated adipocytes. Population analysis was performed using fluorescence-activated cell sorting. Gene expression of early, middle, late, and terminal differentiation stage markers (PPAR),2, lipoprotein lipase, adipsin, leptin, and adipocyte P2 (aP2)] was studied by Northern hybridization, and protein synthesis of aP2 was determined by Western analysis. Results: Nile red staining confirmed increased adipocyte development 10 days after the onset of treatment with 50 mm alcohol and osteogenic induction. By day 21 the number of adipocytes increased to 13.6% of the total population. Alcohol up-regulated the gene expression of PPAR,2 whereas no up-regulation was observed for the other genes. Protein production of aP2 was significantly increased in hMSC cells by culture in the presence of alcohol. Conclusions: The data suggest that alcohol's adipogenic effect on cultured hMSC is through up-regulation of PPAR,2 at the point of lineage commitment as well as through enhancement of lipid transport and storage through increased aP2 synthesis. The alcohol-induced expression and synthesis changes account for the increased Nile red staining of cultured hMSC. [source] The goals of direct paternal care among a South Amerindian populationAMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY, Issue 3 2009Jeffrey Winking Abstract Human males are remarkable among mammals in the level of investment they provide to their wives and children. However, there has been debate as to the degree to which men actually invest and through which fitness pathways the benefits of familial investment are realized. Much of the previous research exploring these issues has focused on men's roles as providers, but few have explored correlates of men's direct parental care. Although this is reasonable given men's parental emphasis on provisioning, the providing of direct care is more straightforward with a clear provider and recipient and little ambiguity as to the care-giver's intent. Here, we explore contextual correlates of men's direct care among the Tsimane of Bolivia to determine the extent to which such care is patterned to enhance its effectiveness in increasing child wellbeing and the efficient functioning of the family. We also explore whether Tsimane fathers provide care in ways that enhance the positive effect it has on the wife's perception of the care provider. Overall, we find that Tsimane men appear responsive to the needs of children and the family, but show that there is little evidence that men respond to factors expected to increase the impact that men's care has on their reputations with their wives. Am J Phys Anthropol 2009. © 2009 Wiley-Liss, Inc. [source] The postejaculatory refractory period: a neurophysiological study in the human maleBJU INTERNATIONAL, Issue 9 2000U. Yilmaz Objective To investigate changes in the penile sensory threshold, and the variables of cortical somatosensory evoked potential and sacral evoked response tests in the early postejaculatory period in the human male. Subjects and methods Twenty healthy volunteers (mean age 25.3 years, range 17,32) were evaluated before and after ejaculation for penile sensory threshold values, and the variables of sacral evoked response and cortical somatosensory evoked potential tests. Results Three subjects were excluded from the statistical analyses because there were significant differences among the repeated tests. In the remaining 17 subjects the penile sensory threshold was significantly greater in the postejaculatory period (P < 0.05). There were no significant changes in the other variables of both the sacral evoked response and cortical somatosensory evoked potential tests after ejaculation (P > 0.05). Conclusion The postejaculatory refractory period in the human male is accompanied by a greater penile sensory threshold but with no change in the values of the sacral evoked response and cortical somatosensory evoked potential. [source] Biological measurement of estrogenic activity in urine and bile conjugates with the in vitro ER-CALUX reporter gene assayENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 3 2002Juliette Legler Abstract Although estrogens are excreted as biologically inactive conjugates, they can be reconverted to an active form, possibly by bacteria. A simple method was developed to deconjugate estrogen metabolites present in human urine and fish bile back to active estrogens by enzymatic hydrolysis with ,-glucuronidase or live Escherichia coli cells. Deconjugated extracts were tested for estrogenic activity in the in vitro stable estrogen receptor,mediated chemical-activated luciferase gene expression (ER-CALUX) assay. Estrogen glucuronides in urine obtained from human males and females were effectively converted to active forms after incubation with ,-glucuronidase or E. coli. The highest estrogenic activity was found in deconjugated metabolites from urine of a pregnant woman, in which levels up to 3,000 nmol estradiol equivalents per liter of urine were found after overnight incubation of urine with E. coli. Bile sampled from male bream and flounder from various freshwater and marine locations was also deconjugated and a good correlation was found between high biliary estrogenic activity and elevated levels of xenoestrogenic activity in surface water as well as in plasma vitellogenin. Therefore, the measurement of deconjugated bile could form a useful (indirect) biomarker for internal dose of xenoestrogens in male fish. [source] Correlation between gross anatomical topography, sectional sheet plastination, microscopic anatomy and endoanal sonography of the anal sphincter complex in human malesJOURNAL OF ANATOMY, Issue 2 2009S. Al-Ali Abstract This study elucidates the structure of the anal sphincter complex (ASC) and correlates the individual layers, namely the external anal sphincter (EAS), conjoint longitudinal muscle (CLM) and internal anal sphincter (IAS), with their ultrasonographic images. Eighteen male cadavers, with an average age of 72 years (range 62,82 years), were used in this study. Multiple methods were used including gross dissection, coronal and axial sheet plastination, different histological staining techniques and endoanal sonography. The EAS was a continuous layer but with different relations, an upper part (corresponding to the deep and superficial parts in the traditional description) and a lower (subcutaneous) part that was located distal to the IAS, and was the only muscle encircling the anal orifice below the IAS. The CLM was a fibro-fatty-muscular layer occupying the intersphincteric space and was continuous superiorly with the longitudinal muscle layer of the rectum. In its middle and lower parts it consisted of collagen and elastic fibres with fatty tissue filling the spaces between the fibrous septa. The IAS was a markedly thickened extension of the terminal circular smooth muscle layer of the rectum and it terminated proximal to the lower part of the EAS. On endoanal sonography, the EAS appeared as an irregular hyperechoic band; CLM was poorly represented by a thin irregular hyperechoic line and IAS was represented by a hypoechoic band. Data on the measurements of the thickness of the ASC layers are presented and vary between dissection and sonographic imaging. The layers of the ASC were precisely identified in situ, in sections, in isolated dissected specimens and the same structures were correlated with their sonographic appearance. The results of the measurements of ASC components in this study on male cadavers were variable, suggesting that these should be used with caution in diagnostic and management settings. [source] Reduced alpha adrenergic mediated contraction of renal preglomerular blood vessels as a function of gender and agingJOURNAL OF CELLULAR BIOCHEMISTRY, Issue 4 2005John C. Passmore Abstract As human males age, a decline in baroreflex-mediated elevation of blood pressure occurs due, at least in part, to a reduction in alpha-1 adrenergic vasoconstrictor function. Alpha adrenergic constriction is mediated by guanosine triphosphate binding Protein (G Protein) coupled signaling pathways. Alpha-1 A/C, B, and D adrenergic receptor expressions, measured by GeneChip array, are not reduced during aging in renal blood vessels of male or female rats. Alpha-1 A GeneChip expression is greater, at all ages studied, in females than in males. Prazosin binding by alpha-1 adrenergic receptors is greater in young adult female rats than in young adult male rats; however, it is reduced with aging in both male and female rats. G alpha q GeneChip expression declines while expression of adrenergic receptor kinase (GRK2) and tyrosine phosphatases (TyrP) increase with aging in male rats. The declines in alpha-1 adrenergic receptor binding and G alpha q expression and also the increases in GRK2 and TyrP expression likely relate to the age-related decline of vasoconstriction in male rats. The information that the expression of alpha-1 A adrenergic receptors is greater in female rats and (GRK2) expression does not increase during aging could relate to the gender differences in vasoconstrictor function with aging. Gene therapy to ameliorate the age-related decline in renal function could possibly reduce the need for renal dialysis. Signaling pathways such as those reviewed herein may provide an outline of the molecular pathways needed to move toward successful renal gene therapy for aging individuals. J. Cell. Biochem. © 2005 Wiley-Liss, Inc. [source] Sex differences in response to steroids in preterm sheep lungs are not explained by glucocorticoid receptor number or binding affinity,PEDIATRIC PULMONOLOGY, Issue 1 2001Jana Kovar BScHons Abstract We recently reported that prenatal glucocorticoid therapy is less effective at promoting an improvement in lung function in male than in female sheep. This observation, and the higher incidence of respiratory distress syndrome in human males, suggests that the male fetal lung may be less responsive to glucocorticoids than is the female fetal lung. Since glucocorticoids are known to exert their effects via specific cytoplasmic glucocorticoid receptors (GR), we hypothesized that there may be sexual dimorphism in either the number or binding affinity of lung GR. To test the hypothesis, binding of dexamethasone (a synthetic glucocorticoid, 0.5,40 nM) by cytosolic fractions of male (n,=,16) and female (n,=,16) fetal sheep lung was measured at 125 days gestation (term,=,148 days). Scatchard analysis of dexamethasone binding showed that the total number of GR (Bmax) did not significantly differ between male (346,±,42 fmol/mg protein) and female (277,±,23 fmol/mg protein) fetuses. The measured binding affinity (Kd) in male fetal lungs (6.85,±,0.43 nM) was not significantly different from that in females (8.46,±,1.02 nM). In conclusion, this study suggests that sex differences in fetal sheep lung responses to glucocorticoid therapy are not due to differences in the number or binding affinity of lung GR. Pediatr Pulmonol. 2001; 32:8,13. © 2001 Wiley-Liss, Inc. [source] Circadian variation in salivary testosterone across age classes in Ache Amerindian males of ParaguayAMERICAN JOURNAL OF HUMAN BIOLOGY, Issue 2 2010Richard G. Bribiescas Testosterone levels exhibit a circadian rhythm in healthy men, with morning levels tending to be higher compared to evening titers. However, circadian rhythms wane with age. Although this has been described in males living within industrialized settings, age-related changes have not received similar attention in populations outside these contexts. Because many nonindustrialized populations, such as Ache Amerindians of Paraguay, exhibit testosterone levels that are lower than what is commonly reported in the clinical literature and lack age-associated variation in testosterone, it was hypothesized that Ache men would not show age-related variation in testosterone circadian rhythms. Diurnal rhythmicity in testosterone within and between Ache men in association with age (n = 52; age range, 18,64) was therefore examined. A significant negative association was evident between the ratio of morning and evening salivary testosterone and age (r = ,0.28, P = 0.04). Men in their third decade of life exhibited significant diurnal variation (P = 0.0003), whereas older and younger age classes did not. Men between the ages of 30 and 39 also exhibited a higher AM:PM testosterone ratio compared to 40,49 and 50< year old men (P = 0.002, 0.006). Overall, declines in testosterone with aging may not be universal among human males, however, within-individual analyses of diurnal variation capture age-related contrasts in daily testosterone fluctuations. Circadian rhythmicity differs with age among the Ache and may be a common aspect of reproductive senescence among men regardless of ecological context. Am. J. Hum. Biol., 2010. © 2009 Wiley-Liss, Inc. [source] A reassessment of sexual dimorphism in human senescence: Theory, evidence, and causationAMERICAN JOURNAL OF HUMAN BIOLOGY, Issue 2 2006Brent M. Graves Age-specific mortality rates of men are higher than those of women, and men have shorter average life spans than women. This has been interpreted as evidence of sexual dimorphism in rates of senescence. However, because mortality can be caused by numerous factors in addition to senescence, higher mortality rates do not necessarily indicate more rapid senescence. In this paper, we (1) emphasize the necessity of decoupling mortality and senescence when considering sexual dimorphism in senescence, (2) present a theoretical framework for the hypothesis that selection affects senescence in human males and females differently due to different life history characteristics, (3) consider phenotypic evidence from the literature that human males show a later onset of senescence than human females, despite exhibiting higher mortality rates, and (4) discuss the potential roles of mutation accumulation and antagonistic pleiotropy in the evolution of sexual dimorphism in senescence. Am. J. Hum. Biol. 18:161,168, 2006. © 2006 Wiley-Liss, Inc. [source] Fluctuating and directional asymmetry in young human males: Effect of heavy working condition and socioeconomic status,AMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY, Issue 1 2010Özener Abstract Many adverse environmental and genetic factors can affect stability of development during human growth. Although the level of fluctuating asymmetry (FA) may be influenced by environmental and genetic stress encountered during this period, directional asymmetry (DA) is largely attributable to differential mechanical loading during bone growth, for example, handedness. I assessed the effects of heavy working conditions and socioeconomic conditions on asymmetry levels in three groups of young human males: 1) individuals employed in the heavy industry sector (n = 104, mean age = 18.48 ± 0.61 years), 2) individuals who had the same socioeconomic status as the laborers (n = 102, mean age = 18.39 ± 0.58 years) but were not laborers, and 3) nonlaborers from the higher socioeconomic levels of society (n = 103, mean age = 18.43 ± 0.67). For all subjects, hand length, hand width, elbow width, wrist width, knee width, ankle width, foot length, foot width, ear length, and ear width were measured. All measurements of the upper extremities in the labor group appeared to exhibit DA; in the other two groups only hand measurements exhibited DA. According to analysis of FA, subjects living in poor conditions exhibited more FA than their nonlaborer peers living in better conditions. In addition, biomechanical pressures due to heavy working conditions of the labor group appeared to cause increased DA in the upper extremities: DA increased with an increase in the number of years working. Am J Phys Anthropol 143:13,20, 2010. © 2010 Wiley-Liss, Inc. [source] Testosterone, physical activity, and somatic outcomes among Filipino malesAMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY, Issue 4 2010Lee T. Gettler Abstract Testosterone (T) facilitates male investment in reproduction in part through its anabolic effects on skeletal muscle. Traits like muscle and strength are energetically costly but are believed to enhance competitive ability in humans and other mammals. However, there are limited data on relationships between T and somatic outcomes in lean, non-western populations. We evaluate relationships between waking and pre-bed salivary T and adiposity, fat-free mass (FFM), arm muscle area (AMA), and grip strength (GS) in a large, population-based birth cohort of young adult Filipino males (20.8,22.6 years, n = 872). Data were collected as part of the Cebu Longitudinal Health and Nutrition Survey. Neither waking nor evening T predicted FFM, AMA, or GS. However, there were borderline or significant interactions between T and basketball playing (the most common team sport) and weight lifting as predictors of outcomes: higher waking T predicted higher FFM (activity × T interaction P < 0.01), AMA (interaction P < 0.1), and GS (interaction P < 0.02) among frequent basketball players, and GS (interaction P < 0.09) among the smaller sample of weight lifters. In contrast to clinical studies, but consistent with findings in several subsistence-level populations, T was positively related to adiposity in these lean young males, suggesting that energy status might regulate circulating T. Our findings support a role of the prewaking rise in T as a determinant of energetic allocation to lean mass and strength in the context of repeated muscular use and support the hypothesized role of T as a mediator of investment in costly somatic traits in human males. Am J Phys Anthropol 142:590,599, 2010. © 2010 Wiley-Liss, Inc. [source] Interactions between visitors and Formosan macaques (Macaca cyclopis) at Shou-Shan Nature Park, TaiwanAMERICAN JOURNAL OF PRIMATOLOGY, Issue 3 2009Minna J. Hsu Abstract Ecotourism involving feeding wildlife has raised public attention and is a controversial issue, especially concerning nonhuman primates. Between July 2002 and April 2005, the behavior of monkeys and tourists was collected through scan samplings, focal samplings and behavior samplings at the Shou-Shan Nature Park located in Taiwan's second largest city,Kaohsiung. In addition, the number of tourists and monkeys was counted in different hours and places within the park. Four hundred visitors were interviewed using a questionnaire to gather data on sex, age, purpose and frequency of visit to the park. The number of tourists was significantly higher during weekends than in weekdays in all locations. Humans dominated in the initiation of interspecies interactions,the overall ratio of human-initiated and monkey-initiated interactions was 2.44:1. Human,monkey conflicts accounted for only 16.4% of the total interactions (n=2,166), and adult human males and adult male macaques participated in higher rates than other age/sex groups in these conflicts. Visitors showed more affiliative behavior (15.9%) than agonistic behavior (8%) toward the macaques. In response to visitors' threat or attack, the Formosan macaques mostly showed submissive behavior with bared teeth, squealed or ran away to avoid confrontation (69.1%),only few responded with counteraggression (18.7%). This study for the first time provided evidence that food provisioning increased both the frequency and duration of aggression among Formosan macaques (P<0.001). During food provisioning, the average frequency and the duration of agonistic events of macaques were more than 4 times higher compared with those without food provisioning. The average frequency of food provision by tourists was 0.73,times/hr,more than twice the incident that monkeys grabbed the food from tourists (0.34,times/hr). If people refrain from feeding monkeys and destroying the city park's natural vegetation, monkeys can be used to educate public about nature conservation in an urban setting. Am. J. Primatol. 71:214,222, 2009. © 2008 Wiley-Liss, Inc. [source] Is the Male Dog Comparable to Human?ANATOMIA, HISTOLOGIA, EMBRYOLOGIA, Issue 4 2002A Histological Study of the Muscle Systems of the Lower Urinary Tract Because of their superficial anatomical resemblance, the male dog seems to be suitable for studying the physiologic and pathological alterations of the bladder neck of human males. The present study was carried out to compare and contrast the muscular anatomy of the male dog lower urinary tract with that of humans. The complete lower urinary tract, including the surrounding organs (bulb of penis, prostate, rectum and musculature of the pelvic floor) were removed from adult and newborn male dogs and histologically processed using serial section technique. Based on our own histological investigations, three-dimensional (3D)-models of the anatomy of the lower urinary tract were constructed to depict the corresponding structures and the differences between the species. The results of this study confirm that the lower urinary tract of the male dog bears some anatomical resemblance (musculus detrusor vesicae, prostate, prostatic and membranous urethra) to man. As with human males, the two parts of the musculus sphincter urethrae (glaber and transversostriatus) are evident in the canine bladder neck. Nevertheless, considerable differences in formation of individual muscles should be noted. In male dogs, no separate anatomic entity can be identified as vesical or internal sphincter. The individual course of the ventral and lateral longitudinal musculature and of the circularly arranged smooth musculature of the urethra is different to that of humans. Differences in the anatomy of individual muscles of the bladder neck in the male dog and man suggest that physiological interpretations of urethral functions obtained in one species cannot be attributed without qualification to the other. [source] | |||||||||||||