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INTRODUCTION Recent studies have reported an inverse relationship between bone marrow adipose tissue (BMAT) and bone mineral density (BMD) in human subjects. (1-5) However, it is unknown whether this relationship [...], BACKGROUND/OBJECTIVES: Recent research has shown an inverse relationship between bone marrow adipose tissue (BMAT) and bone mineral density (BMD). There is a lack of evidence at the macro-imaging level to establish whether increased BMAT is a cause or effect of bone loss. This cross-sectional study compared the BMAT and BMD relationship between a younger adult group at or approaching peak bone mass (PBM; age 18.0-39.9 years) and an older group with potential bone loss (PoBL; age 40.0-88.0 years). SUBJECTS/METHODS: Pelvic BMAT was evaluated in 560 healthy men and women with T1-weighted whole-body magnetic resonance imaging. BMD was measured using whole-body dual-energy X-ray absorptiometry. RESULTS: An inverse correlation was observed between pelvic BMAT and pelvic, total and spine BMD in the younger PBM group (r =-0.419 to -0.461, P CONCLUSIONS: Our findings indicate that an inverse relationship between pelvic BMAT and BMD is present both in younger subjects who have not yet experienced bone loss and also in older subjects. These results provide support at the macro-imaging level for the hypothesis that low BMD may be a result of preferential differentiation of mesenchymal stem cells from osteoblasts to adipocytes. European Journal of Clinical Nutrition (2012) 66, 983-988; doi: 10.1038/ejcn.2012.35; published online 11 April 2012 Keywords: body composition; bone marrow adipose tissue; bone mineral density; dual-energy X-ray absorptiometry; magnetic resonance imaging; aging

The urethral rhabdosphincter and pelvic floor muscles are important in maintenance of urinary continence and in preventing descent of pelvic organs [i.e., pelvic organ prolapse (POP)]. Despite its clinical importance and complexity, a comprehensive review of neural control of the rhabdosphincter and pelvic floor muscles is lacking. The present review places historical and recent basic science findings on neural control into the context of functional anatomy of the pelvic muscles and their coordination with visceral function and correlates basic science findings with clinical findings when possible. This review briefly describes the striated muscles of the pelvis and then provides details on the peripheral innervation and, in particular, the contributions of the pudendal and levator ani nerves to the function of the various pelvic muscles. The locations and unique phenotypic characteristics of rhabdosphincter motor neurons located in Onuf's nucleus, and levator ani motor neurons located diffusely in the sacral ventral horn, are provided along with the locations and phenotypes of primary afferent neurons that convey sensory information from these muscles. Spinal and supraspinal pathways mediating excitatory and inhibitory inputs to the motor neurons are described; the relative contributions of the nerves to urethral function and their involvement in POP and incontinence are discussed. Finally, a detailed summary of the neurochemical anatomy of Onuf's nucleus and the pharmacological control of the rhabdosphincter are provided. urethra; incontinence; micturition; defecation; pelvic organ prolapse doi: 10.1152/ajpregu.00111.2010.

The current study investigates whether the spinal pelvic nerve-to-external urethra sphincter (EUS) reflex potentiation can be induced by a mechanical stimulation and whether the glutamatergic mechanism is involved in yielding such a reflex potentiation. The external urethra sphincter electromyogram (EUSE) activity, evoked by a single or by repetitive pelvic nerve stimulation, in 30 anesthetized rats was recorded with/without bladder saline distension. Without saline distension (0 cm[H.sub.2]O), a single pulse nerve stimulation evoked a single action potential in the reflex activity, whereas repetitive pelvic stimulation and saline distension (6-20 cm[H.sub.2]O) both elicited a long-lasting reflex potentiation (20.05 [+ or -] 3.21 and 75.01 [+ or -] 9.87 spikes/ stimulation, respectively). The saline distension-induced pelvic nerve-to-EUS reflex potentiation was abolished by D-2-amino-5-phosphonovalerate [APV; a glutamatergic N-methyl-D-aspartic acid (NMDA) receptor antagonist; 100 [micro]M, 10 [micro]l, 1.72 [+ or -] 0.31 spikes/ stimulation] and attenuated by 2,3-dihydroxy-6-nitro-7-sulfamoylbenzo (F) quinoxaline [NBQX; a glutamatergic [alpha]-amino-3-hydroxy-5-methyl-4-isoxazoleproprionate (AMPA) receptor antagonist; 100 [micro]M, 10 [micro]l, 26.16 [+ or -] 7.27 spikes/stimulation], but was not affected by bicuculline (a GABAergic antagonist; 100 [micro]M, 10 [micro]l, 53.62 [+ or -] 15.54 spikes/stimulation). Intrathecal administration of glutamate (31.12 [+ or -] 8.25 spikes/stimulation, 100 [micro]M, 10 [micro]l) and NMDA (26.25 [+ or -] 4.12 spikes/stimulation, 100 [micro]M, 10 [micro]l) both induced a long-lasting pelvic nerve-to-EUS reflex potentiation without saline distension, which was similar to the findings observed from saline distension only. The duration of the contraction wave of the urethra was elongated by the saline distension-induced pelvic nerve-to-EUS reflex potentiation, whereas the peak pressure of the contraction wave was not affected. Our findings suggest that saline distension in the bladder elicits a pelvic nerve-to-EUS reflex potentiation and the glutamatergic mechanism contributes to the presence of such a reflex potentiation. pelvic nerve; urethra; LTP; AMPA doi: 10.1152/ajprenal.00443.2006

A study was conducted to analyze whether PGE2 increases the release of substance P from renal pelvic sensory nerves. Rats were anesthetized with pentobarbital sodium. The renal pelvic walls were allowed to equilibrate for 130 minutes. Results indicated that PGE2 increases the release of substance P from renal pelvic sensory nerves by a calcium-dependent mechanism that requires influx of calcium via N-type calcium channels.

Changes in pelvic shape in human ontogeny and hominid phylogeny suggest that the heterochronic processes involved differ greatly from the neotenic process traditionally described in the evolution of the skull. The morphology of 150 juvenile and adult pelves of African apes, 60 juvenile and adult pelves of modern humans, two adult pelves and a juvenile hip bone of australopithecines (Sts 14, AL 288, MLD 7) was studied. Multivariate results, ontogenetic allometries, and growth curves confirm that the pelvic growth pattern in humans differs markedly from those of the African apes. The results permit the following conclusions. First, the appearance of a new feature (acetabulo-cristal buttress and cristal tubercle) at the time of human birth allows the addition of traits, such as the attainment of a proportionally narrower pelvis, with more sagittally positioned iliac blades. Pelvic proportions and orientation change progressively in early childhood as bipedalism is practiced. Other changes in pelvic proportions occur later with the adolescent growth spurt. Second, comparison of juvenile and adult australopithecines to modern humans indicates that 1) some pelvic traits of adult Australopithecus resemble those of neonate Homo; 2) the pelvic growth of Australopithecus was probably closer to that of apes, than to that of humans; and 3) prolonged growth in length of hindlimb and pelvis after sexual maturity seems to be a unique feature of Homo. The position of the acetabulo-cristal buttress and of the cristal tubercle on the ilium are similar in adult Australopithecus and neonate Homo suggesting that this feature may have been displaced later during hominid evolution. Progressive displacement of the acetabulo-cristal buttress on the ilium occurs both during hominid evolution (from Australopithecus to Homo sapiens) and human growth (from neonate to adult). This suggests peramorphic evolution of the pelvic morphology of hominids combining three processes of recapitulation (pre-displacement, acceleration and time hypermorphosis). The results lend credence to the hypothesis that no single heterochronic process accounts for all human evolutionary change; rather this reflects a combination of relative changes in growth rhythm and duration, including other perturbations, such as the appearance of new morphological features. KEY WORDS pelvis; ontogeny; heterochrony; allometry; Homo; Australopithecus; Pan; Gorilla

Three experiments were conducted on 20 individuals to determine the effects of pelvic angle variation in using a pelvic support. All experiments were performed with and without pelvic support. The first experiment showed that the use of pelvic support provide more stability on the waist and pelvis. The second experiment, which involves different pelvic angles, showed that most participants displayed no significant change in posture. The last experiment showed that a slope of less than 10 degrees on chair pan surface provide a positive effect, while angles of 20 and 30 degrees had a negative effect.

This study was conducted to determine relative relationships among factors affecting dystocia in Brahman-cross heifers. Body and pelvic measurements were obtained in mid-June (when heifers were approximately 17 mo old), 45 d after a 60-d breeding season. Heifers studied were 207 Red Brangus, 209 Simbrah, and 250 Braford bred to Black Angus bulls; calving began on December 1. Heifers grazed stockpiled bahia and hemarthria grass or ryegrass supplemented with 0.9 kg of 32% protein cottonseed meal and 1.8 kg of mill-run black strap molasses daily during calving. Calvings were scored (1 = no difficulty to 4 = major difficulty). A random sample of birth weights were obtained on 131 and 210 calves in 1992 and 1993. Data were analyzed within year by SAS procedures. Breed differences in dam size and pelvic measurements were highly significant. Residual correlations between body weight and pelvic area were .20 and .35 (both P < .01) for 1991 and 1992. Dystocia incidence was 6.9% in 1992 and 10.5% in 1993, with higher incidence in males than in females (1992, 10.6 vs 3.1%, P = .08; 1993, 15.6 vs 4.2%, P < .01, male vs female, respectively). Male birth weight exceeded (P < .01) that of females (26.7 vs 24.3 kg, 1992; 28.1 vs 26.1 kg, 1993). Correlations among dam size and calf birth weight were not significant. Birth weight was significantly correlated with dystocia score (.19 and .49, 1992 and 1993). Path analyses of influences on dystocia found birth weight, dam heart girth, and body weight significant in 1992, but only birth weight significant in 1993. Regression of calving score on birth weight was curvilinear and significant in both years, with the birth weight inflection point at 22 kg. We conclude that dam body size data obtained following the breeding season were of minor value in determining dystocia, but birth weight was consistently important. Key Words: Dystocia, Pelvic Area, Body Size, Birth Weight, Heifers

Extracellular electrodes attached to 240 cells in the renal pelvis monitored electrical impulses travelling along this region of the kidney. The impulses are generated at one point on the pelvicalyceal border which acts as a pacemaker for a series of impulses that are then carried as wave of conductance throughout the tissue. After a few conductance waves, other cells on the border take on the role of a pacemaker. Conductance blocks also occur randomly along the pelvis.

Sexual dimorphism of the human pelvis is inferentially related to obstetrics. However, researchers disagree in the identification and obstetric significance of pelvic dimorphisms. This study addresses three issues. First, common patterns in dimorphism are identified by analysis of pelvimetrics from six independent samples (Whites and Blacks of known sex and four Amerindian samples of unknown sex). Second, an hypothesis is tested that the index of pelvic dimorphism (female mean X 100/male mean) is inversely related to pelvic variability. Third, the pelvic dimensions of the Neandertal male from Kebara cave, Israel are compared with those of the males in this study. The results show that the pelvic inlet is the plane of least dimorphism in humans. The reason that reports often differ in the identification of dimorphisms for this pelvic plane is that both the length of the pubis and the shape of the inlet are related to nutrition. The dimensions of the pelvis that are most dimorphic (that is, female larger than male) are the measures of posterior space, angulation of sacrum, biischial breadth, and subpubic angle. Interestingly, these dimensions are also the most variable. The hypothesis that variability and dimorphism are inversely related fails to be supported. The factors that influence pelvic variability are discussed. The Kebara 2 pelvis has a spacious inlet and a confined outlet relative to modern males, though the circumferences of both planes in the Neandertal are within the range of variation of modern males. The inference is that outlet circumference in Neandertal females is also small in size, but within the range of variation of modern females. Arguments that Neandertal newborns were larger in size than those of modern humans necessarily imply that birth was more difficult in Neandertals.

For over a century, the pelvis in general and the pubis in particular have been recognized as being highly sexually dimorphic and the best source of information when determining the sex of an unknown individual. However, from its earliest descriptions, the measurement of the pubis length has been poorly defined. Using samples from the Terry Collection (n = 332) and the Coimbra Collection (n = 223), the purpose of this research is to (1), test the reproducibility of an alternative to the traditional measurement of the pubis, and (2) to use the best measurement of the pubis (along with other measurements of the pelvis and femur) to develop a metric method that can be used with confidence to determine the sex of individuals of various geographic origins and time periods. In this study, it was found that, (1) the alternative pubis measurement can be collected more reliably with less mean intraobserver error ([is less than] 0.6%) then the more commonly used manner of measuring the pubis (2.7%); (2) a sex determination method using the new pubis measurement, along with other measurements of the pelvis and femur, discriminates between the sexes across various independent samples with an allocation accuracy of up to 98% (depending on the model used and the manner of testing); and (3) traditional racial categorization was irrelevant to the accuracy of the method.

The Finite Element Method (FEM) can be used to analyze very complex geometries, such as the pelvis, and complicated constitutive behaviors, such as the heterogeneous, nonlinear, and anisotropic behavior of bone tissue or the noncompression, nonbending character of ligaments. Here, FEM was used to simulate the mechanical ability of several external and internal fixations that stabilize pelvic ring disruptions. A customized pelvic fracture analysis was performed by computer simulation to determine the best fixation method for each individual treatment. The stability of open-book fractures with external fixations at either the iliac crests or the pelvic equator was similar, and increased greatly when they were used in combination. However, external fixations did not effectively stabilize rotationally and vertically unstable fractures. Adequate stabilization was only achieved using an internal pubis fixation with two sacroiliac screws. [S0148-0731(00)00905-5]