Location and geometric description of carpal bones in CT images

The carpal regions of ten cadaver extremities were imaged by CT. The images were combined into a 3-dimensional model of the carpus using a technique based on a dynamic programming algorithm to find an optimal estimate of the location of the bone boundaries in the CT images. The resulting set of surface points on each bone was used to compute volumes and principal and antipodal axes for the bones. A spatial coordinate system was established based on the positions of the centroids of three bones in the distal carpal row. The angular orientations of all carpal bones were determined with respect to this system. The principal axes for the same bone among ten wrist specimens proved to be more widely dispersed than the antipodal axes for the same bones. The antipodal axes also correspond more closely to an intuitive notion of the “longest axis” of the bones. We conclude that the antipodal axis is a more reliable and useful measure of bone orientation than the principal axis.     

Lumbar subarachnoid catheterization in rats

An animal model was developed for the study of subarachnoid (spinal) anesthesia and analgesia under unanesthetized, unsedated and unrestrained conditions. Sprague-Dawley rats were anesthetized with intraperitoneal ketamine (75-100 mg.kg-1). A PE10 catheter was inserted under direct vision into the lumbar subarachnoid space, through partial laminectomy of L1 or L2 with or without removal of adjacent intervertebral ligament. One week after surgery, correct position of the catheter was verified by subarachnoid injection of 0.03-0.05 ml of 1.5% lidocaine, which produced temporary hind limb paralysis in all but one animal in 28 consecutive operations. There was neither mortality nor major complication, intraoperatively or postoperatively. Only 2 animals developed minor subcutaneous would infections which responded to incision, drainage and debridement.     

P2X(7) receptors are expressed during mouse nephrogenesis and in collecting duct cysts of the cpk/cpk mouse.

BACKGROUND: Purinergic receptors are cell-surface molecules that bind extracellular nucleotides, notably ATP. The P2X family includes seven nonselective ion channels with one member, P2X(7), implicated in cytolytic pore formation and cell death. MATERIALS AND METHODS: We sought P2X(7) expression in mouse nephrogenesis and cpk/cpk renal cyst growth, conditions in which both proliferation and apoptosis are prominent. RESULTS: P2X(7) immunolocalized to condensed metanephric mesenchyme: both proliferation and apoptosis were detected in this compartment, assessed by proliferating cell nuclear antigen expression and propidium iodide-stained pyknotic nuclei respectively. Later in nephrogenesis, P2X(7) was detected in collecting ducts, a pattern persisting to maturity. A mesenchymal to epithelial shift of P2X(7) expression was also documented in ureter development. In cpk/cpk kidneys, P2X(7)-expressing collecting duct cysts dominated histology from two weeks until four weeks after birth, when animals die from uremia. In polycystic kidneys pyknotic nuclei were rarely identified in P2X(7)-expressing epithelia, but were detected between cysts, consistent with a non-apoptotic role for P2X(7) in cyst enlargement. CONCLUSION: P2X(7) is expressed during normal nephrogenesis and in a model of congenital polycystic kidney disease. Further experiments are necessary to define possible functions of P2X(7) in these settings.     

AMPK在妊娠期糖尿病发病机制中的作用

腺苷酸活化蛋白激酶是一种重要的蛋白激酶,主要作用是协调代谢和能量平衡.腺苷酸活化蛋白激酶被激活后,在增加骨骼肌对葡萄糖摄取、增强胰岛素敏感性、增加脂肪酸氧化以及调节基因转录等方面发挥重要作用.已经证实脂联素有调节糖脂代谢的作用,但其作用机制尚不十分清楚,很可能是通过腺苷酸活化蛋白激酶介导,对脂联素信号转导通路的研究将成为进一步理解脂联素作用的关键所在.而脂联素又是妊娠期糖尿病的预测因子,所以腺苷酸活化蛋白激酶逐渐成为对妊娠期糖尿病研究中的焦点.     

Prospective comparison of plain abdominal radiography with conventional and digital renal tomography in assessing renal extracorporeal shock wave lithotripsy patients

Most publications citing the effectiveness of renal extracorporeal shock wave lithotripsy have used plain abdominal radiography to assess residual calculi after treatment. We compared radiologist sensitivity and specificity in the detection of calculi on plain abdominal radiographs versus conventional film-screen and digital renal tomograms in extracorporeal shock wave lithotripsy patients. Of the patients 50 were imaged before and within 24 hours after lithotripsy. Six radiologists evaluated the resultant 300 studies for the presence and location of calculi. The mean sensitivity for digital tomograms was 83% for pre-lithotripsy and post-lithotripsy studies, which was significantly higher than for plain abdominal radiography and conventional tomography after lithotripsy. However, there were significantly more false positive stone diagnoses associated with digital tomogram interpretation. Signal detection analysis verified the over-all superiority of digital tomography for post-extracorporeal shock wave lithotripsy imaging. Calculus detection by conventional and digital tomography is superior to detection by plain abdominal radiography. However, because we did not perform delayed imaging, it is not possible to say what impact digital tomography might have on the management of extracorporeal shock wave lithotripsy patients.     

Abdominal Pumping

This article reviews the author's experience with a form of interposed abdominal compression cardiopulmonary resuscitation (IAC-CPR) in the United Kingdom. The development of the technique based upon animal resuscitation, including the use of phasic compression (abdominal pumping) for the resuscitation of rats from 30 minutes of cardiac arrest due to hypothermia, is reviewed. A simple technique for clinical use is described. The technique uses a hard-covered book or bean-shaped board applied to the abdomen below the umbilicus and compressed alternately with cardiac massage while respiration is assisted. Anecdotal clinical results suggest that further controlled clinical investigation is warranted.