Phospholipase D- and protein kinase C isoenzyme-dependent signal transduction pathways activated by the calcitonin receptor

The calcitonin receptor expressed by the porcine LLC-PK1 renal tubule cells is a seven-transmembrane domain, G protein-coupled receptor activating adenylyl-cyclase and phospholipase C. Salmon calcitonin stimulated dose- and time-dependent release of the phospholipase D-dependent phosphatidylcholine product [3H] choline with an EC50 = 2.5 +/-0.3 x 10(-8) M, similar to that determined for phosphoinositide metabolism (EC50 = 4.5 +/-1.0 x 10(-8)M). The hormone failed to induce release of [3H]phosphocholine and [3H]glycerophosphocholine, ruling out activation of phosphatydilcholine-specific phospholipase C and phospholipase A. Calcitonin stimulated phosphatidic acid, a product of phospholipase D-dependent phosphatydilcholine hydrolysis. Activation of phospholipase D was confirmed by release of [3H]phosphatydilethanol, a specific and stable product in the presence of a primary alcohol. Activation of calcitonin receptor induced diacylglycerol formation, with a rapid peak followed by a prolonged increase, due to activation of phospholipase C and of phospholipase D. Consequently, the protein kinase-C alpha, but not the delta isoenzyme, was cytosol-to-membrane translocated by approximately 50% after 20 min exposure to calcitonin, whereas protein kinase-C zeta, which was approximately 40% membrane-linked in unstimulated cells, translocated by approximately 19%. The human calcitonin receptor expressed by BIN-67 ovary tumor cells, although displaying higher affinity for calcitonin, failed to activate phospholipase D and protein kinase-C in response to the hormone. This receptor lacks the G protein binding consensus site due to the presence of a 48-bp cassette encoding for a 16-amino acid insert in the predicted first intracellular loop. This modification is likely to prevent the calcitonin receptor from associating to phospholipase-coupled signaling.     

Thoracic discography. A safe and reliable technique

OBJECTIVES: To evaluate the safety and reliability of discography used to investigate thoracic disc degeneration observed on magnetic resonance (MR) imaging studies in patients with clinical pain, we analyzed retrospectively the results of thoracic discograms performed on 100 outpatients. METHODS: After MR imaging, clinically suspect, morphologically abnormal thoracic discs and at least one, nearby, control level were injected with either nonionic contrast or saline, filmed, and individually described by the patient as concordant versus nonconcordant relative to clinical pain and rated in intensity on a scale of 0-10. RESULTS: There were no serious complications in the series, and the authors resolved whether the injected discs related to pain in each case. They found discs with anular tears, intrinsic degeneration, and/or associated vertebral body endplate infractions to be painful approximately 75% of the time. Clinical concordance was approximately 50%. Control levels were usually painless. CONCLUSIONS: They conclude that thoracic discography can be performed safely by experienced individuals as a reliable tertiary diagnostic procedure to determine if degenerated discs on MR studies are related to clinical complaints.     

Conservation of the 168 divIB gene in Bacillus subtilis W23 and B. licheniformis, and evidence for homology to ftsQ of Escherichia coli

Recent reports indicate that combined anterior cruciate ligament/medial collateral ligament (ACL/MCL) knee injuries are usually associated with a lateral meniscus tear. In our center, snow skiing is the athletic activity most frequently associated with this double-ligament injury complex. A sports-specific analysis was undertaken to evaluate the hypothesis that the snow skiing ligament injury is different from similar injuries caused by other athletic activities. Of a total of 64 acute arthroscopically confirmed tears of both the MCL and ACL, 23 were caused by snow skiing and 41 by nonskiing activities. There were fewer lateral meniscus tears in skiers (43%) when compared with the nonskiers (88%). Skiers also had fewer medial meniscus tears (13%) than did nonskiers (37%). No medial meniscus tears occurred in the absence of a lateral meniscus tear. Although 78% of the skiers were women, only 12% of the nonskiers were women. Skiers were older (average age 35 years) than the nonskiers (average age 28 years). The right knee was injured almost twice as frequently as the left. These data suggest that the double (ACL/MCL) ligament injury in skiers might be distinctly different from that in nonskiers.     

Abdominal sonography in asymptomatic executives: prevalence of pathologic findings, potential benefits, and problems

Abdominal ultrasonography was performed on 1000 asymptomatic executives over a period of 6 months as part of a comprehensive health examination. The use of ultrasonography in these persons was evaluated with regard to the prevalence and variety of pathologic conditions detected as well as potential benefits, risks, and use as a screening tool. Significant sonographic diagnoses included renal cell carcinoma in four patients (0.4%) and abdominal aortic aneurysm in four patients (0.4%). Abdominal sonography performed on 7925 asymptomatic executives over a subsequent 2 1/2 year period led to detection of 23 (0.3%) additional renal cell carcinomas. The prevalence of renal cell carcinoma in this population is substantially greater than that of the general population. Abdominal sonography facilitates detection of occult renal neoplasms and aortic aneurysms. The cost effectiveness and potential use of sonography as a screening tool remains to be determined, however, given the relatively low overall prevalence of these pathologic conditions.     

Screening for birth defects: integrating laboratory evaluation, genetic counseling and clinical intervention

The search of inhibitors of the myrosinase enzyme and also enzymes able to transform the glucosinolates into non-toxic combinations has been carried out among the water extracts of the plants row. The inhibitor activity of the water extract of Arctostaphylos uva-ursi and its foresee acting outset-hydroquinone have been discovered. The direct dependence of the glucosinolates decompose degree from concentration of hydroquinone and quinone has been determined. The cultivation of Brassica napus cut seeds by quinone in correlation 1:100 (m:m) stopped the glucosinolates decomposition by endogenous myrosinase for 50%.     

Peripheral nerve allograft preservation improves regeneration and decreases systemic cyclosporin A requirements

Peripheral nerve allografting is limited by the need for long-term systemic immunosuppression. The purpose of this study was to determine if nerve allograft preservation reduced the requirements for systemic Cyclosporin A (CsA) immunosuppression. One hundred twenty Lewis rats were randomized to one of seven experimental groups. Group 1 received a 2-cm Lewis posterior tibial nerve autograft. Groups 2-7 received 2-cm ACI posterior tibial nerve allografts. The allograft group was then further subdivided into three groups of two receiving daily subcutaneous injections of 0, 2.5, or 5.0 mg/kg of CsA for 12 weeks. Within each CsA dose, one group received a fresh while the other received a preserved allograft. Preserved grafts were stored in University of Wisconsin solution for 7 days at 5 degrees C prior to implantation. Animals from each group were sacrificed at 6, 12, and 20 weeks postoperatively. Evaluations included histomorphometry, electrophysiology, and serial walking track analysis. Histology revealed varying degrees of nerve regeneration in all groups at 6, 12, and 20 weeks. For a given CsA dose, the group receiving the preserved graft revealed evidence of better nerve regeneration by all histomorphometric parameters including fiber width and density, percentage neural tissue, and total fiber number. There was no statistical difference in walking track analysis between groups at 4 weeks. By 20 weeks, functional recovery statistically poorer than autograft was seen only in the fresh allograft groups receiving 0 or 2.5 mg/kg of CsA. Identical electrophysiologic findings were seen at 20 weeks. These results suggest that nerve graft preservation may decrease systemic immunosuppression requirements while improving functional recovery. As well, storage of nerve grafts is feasible and would facilitate elective surgery and less costly reconstructive repair.