Citations

In biomechanics, the knowledge of accurate location of a joint center is essential because equilibration of the external loads and muscular forces about the joint is performed about this specific point. This paper focuses on the location of centers of gleno-humeral joint and scapulo-thoracic joint in a subject moving their arm in the scapular plane with a magnitude of 120°. Biplanar radiography with successive exposures has been used locating anatomical axes of bones. Geometric models of bones were defined allowing access to bone morphology by superposing model projections onto X-ray imaged bone contours. Functional models were used so as to represent the behavior in motion of shoulder joints. These techniques allowed us to access to results describing the linear and angular relative displacements of the shoulder bones between two different postures. The gleno-humeral and scapulo-thoracic finite joint centers (F H and F S ) are first defined through the location of the corresponding helical axis of motion (HAM) moving the joint from positions occupied in initial and final postures. The gleno-humeral and scapulo-thoracic mean joint centers (M H and M S ) are then calculated using a new technique, which defines that each joint center has the point having the smallest migrations while moving continuously from initial to final postures. This allows for the analysis of the linear and angular clearances, which affect joint center migration. The whole continuous movement has been parsed into several steps to test the stability of the mean joint center throughout the motion.

Abstract Background: Recent data suggest that older men with detectable cardiac troponin I (cTnI) concentrations that remain below the 99th percentile concentration cutoff are at increased risk for subsequent cardiovascular events. We designed this study to extend this observation by examining risk prediction in both men and women presenting to an emergency department with chest discomfort. Methods: We obtained data for all-cause mortality and hospital discharges associated with either acute myocardial infarction (AMI) or congestive heart failure (CHF) for up to 8 years after the initial presentation in 448 patients who originally presented in 1996 with acute coronary syndrome (ACS). We performed retrospective analysis for cTnI (AccuTnI™; Beckman Coulter) in frozen plasma samples based on the patients’ reported time from onset of symptoms. Peak cTnI concentration was used for risk assessment. Results: Patients with cTnI concentrations ≥0.02 μg/L (i.e., limit of detection), including those whose peak values remained below the 99th percentile (0.04 μg/L), were at greater risk for death and AMI/CHF readmissions at 2, 5, and 8 years of follow-up compared with those with peak cTnI <0.02 μg/L. All results were statistically significant (P <0.05) except for death within 2 years among patients with normal but detectable cTnI (0.02 to 0.03 μg/L), relative to the group with values <0.02 μg/L. Kaplan–Meier analyses indicated that both men and women with cTnI ≥0.02 μg/L had worse outcomes (P <0.001). Conclusion: Both men and women who present with possible ACS with detectable cTnI concentrations that remain below the 99th percentile are at a greater risk for future adverse events.

Abstract Sterol excretion in the spontaneously atherosclerosis‐susceptible White Carneau (WC) pigeon, the Silver King (SK) pigeon and the Show Racer (SR) pigeon was studied by thin layer chromatography (TLC), argentation TLC and gas liquid chromatography. Unlike man and the chicken, these pigeons excreted no coprostanol or coprostanone derivatives of sterols. Moreover incubation of 14 C‐labeled cholesterol with pigeon feces indicated that, also unlike man and the chicken, these pigeons are unable to convert it to coprostanol. Bacteriologic examination revealed the absence of gram‐negative anaerobic flora and of members of the genus Bifidobacterium in both the WC and SR pigeons. On the other hand, one of the two SK pigeons examined showed evidence of the presence of both Bacteroids fragilis and B. bifidum in the upper intestinal tract. Although no qualitative experiments were performed, no unusual characteristics of the aerobic flora were noted in these pigeons. In addition, analysis of human stool specimens indicated a “normal” bowel flora. The flora of the intestinal tract of the chicken is similar to that of the human. Because of this similarity, it appears that differences in environment (living conditions, diets) between the human and the chicken are of little consequence. The results obtained in this study suggest the possibility that the anaerobic gram‐negative flora and sponsible, at least in part, for the chemical conversion of cholesterol to coprostanol.

We present the case of a 3-year-old girl with acute lymphoblastic leukemia who developed isolated central nervous system relapse while receiving chemotherapy 10 months after diagnosis. The child achieved a second remission on retreatment with systemic and intrathecal chemotherapy. She then underwent myeloablative chemotherapy and radiation therapy followed by infusion of her own umbilical cord blood, which the parents had saved after her delivery. She is now doing well and is in complete remission 20 months after cord blood transplantation. In this first report of autologous cord blood transplantation for treatment of childhood leukemia, we discuss the safety and feasibility of this procedure as well as some of the uncertainties surrounding autologous cord blood collection and usage.

Insulin secretion from the 2,000–3,000 β-cells in an islet is a highly synchronized activity with discharge of insulin in coordinate secretory bursts at approximately 4-min intervals. Insulin secretion progressively declines in type 2 diabetes and following islet transplantation. Both are characterized by the presence of islet amyloid derived from islet amyloid polypeptide (IAPP). In the present studies, we examined the action of extracellular human IAPP (h-IAPP) on morphology and function of human islets. Because oligomers of h-IAPP are known to cause membrane disruption, we questioned if application of h-IAPP oligomers to human islets would lead to disruption of islet architecture (specifically cell-to-cell adherence) and a decrease in coordinate function (e.g., increased entropy of insulin secretion and diminished coordinate secretory bursts). Both hypotheses are affirmed, leading to a novel hypothesis for impaired insulin secretion in type 2 diabetes and following islet transplantation, specifically disrupted cell-to-cell adherence in islets through the actions of membrane-disrupting IAPP oligomers.