Acute cocaine results in rapid rises in intracellular free calcium concentration in canine cerebral vascular smooth muscle cells: possible relation to etiology of stroke

We report the outcome of 177 consecutive primary Charnley total hip arthroplasties inserted with Boneloc cement between November 1991 and November 1993. There were 107 women and 70 men. The mean age at the time of the operation was 71 years. 11 patients (13 hips) died during the follow-up period and 3 patients were too weak to attend a follow-up examination. Of the 161 remaining hips, 4 had been revised because of deep infection. The mean follow-up time for the remaining 157 hips was 2 (0.5-3) years. 24 hips had been revised and 6 are waiting for revision because of stem loosening. Of the remaining 127 hips, 72 showed radiographic signs of stem loosening and 2 hips were probably loose. Osteolysis was seen around the femoral component in 56 hips.     

IL-10 impacts autoimmune diabetes via a CD8+ T cell pathway circumventing the requirement for CD4+ T and B lymphocytes

IL-10 is essential for an early phase of diabetes in nonobese diabetic (NOD) mice, but later becomes protective against its development. The mechanism by which IL-10 mediates the pathway to diabetes in these mice is unknown. Herein, we dissected the cellular and costimulation requirements for diabetes in transgenic (tg) NOD mice that expressed IL-10 in their pancreatic islets (IL-10-NOD mice). We found that IL-10 alone did not cause diabetes because the offspring (IL-10-NOD-scid mice) from back-crosses of IL-10-NOD mice with NOD-scid mice had no diabetes. Moreover, these IL-10-NOD-scid mice were free of lymphocytic infiltration. Treatment of IL-10-NOD mice with depleting anti-CD4 mAb or control mAb had no effect on diabetes. Surprisingly, depletion of CD8+ T cells by treatment with the corresponding mAb inhibited diabetes without attenuating insulitis, demonstrating a critical role for CD8+ T cells in the disease process. Interestingly, B cell-deficient IL-10-NOD mice readily developed diabetes with kinetics and incidence similar to those observed in wild-type mice, demonstrating that B lymphocytes as APCs were not required in the disease process. Administration of anti-CD40 ligand (CD40L) mAb did not prevent disease, indicating that CD40/CD40L costimulation is not required for diabetes in IL-10-NOD mice. Immunization of IL-10-NOD mice with CFA or heat-shock protein 65, known to block diabetes in NOD mice, had no effect on their diabetes. We demonstrate that IL-10 contributes early to the pathology of diabetes via a CD8+ T cell pathway, eliminating the requirement for B lymphocytes and CD40-CD40L costimulation. Our findings provide a mechanism for the participation of IL-10 in the early development of diabetes.     

Novel cell imaging techniques show induction of apoptosis and proliferation in mesothelial cells by asbestos

We developed in situ dual-fluorescence detection techniques for measuring apoptosis and proliferation simultaneously in single dishes of cells. The deoxyribonucleic acid (DNA)-specific labeling method, terminal deoxynucleotidyl transferase (TdT)-mediated deoxyuridine triphosphate nick-end labeling (TUNEL), first was used in conjunction with a 4',6-diamidino-2-phenylindole (DAPI) counterstain to detect and measure morphologic characteristics of apoptotic rat pleural mesothelial (RPM) cells isolated from Fischer 344 rats and exposed to 300 microM hydrogen peroxide (H2O2). For this purpose, 100 TUNEL-positive nuclei were measured while being viewed with DAPI counterstaining for area, perimeter, longest diameter, and average diameter, using imaging software and an image-collection apparatus. We then exposed cells to a range of concentrations of crocidolite asbestos and putative apoptotic and mitogenic agents. Exposure to crocidolite asbestos (5 microg/cm2) caused a striking dose-dependent apoptotic response at 24 h, 48 h, and 72 h. The nonfibrous crocidolite analogue riebeckite failed to induce apoptosis. At 24 h, tumor necrosis factor-alpha (TNF-alpha) (10 ng/ml) caused an increase in apoptotic nuclei. A second method, utilizing an antibody to 5'-bromodeoxyridine (BrdU) and oxazole yellow homodimer (YOYO), showed a dose-dependent increase in proliferation occurring in cells exposed to asbestos (5 microg/cm2) at 48 h and 72 h. In addition, increased numbers of rat pleural mesothelial (RPM) cells exposed to 12-O-tetradecanoylphorbol-13-acetate (TPA), TNF-alpha, and epidermal growth factor (EGF) exhibited incorporation of BrdU at these time points, although total numbers of cells per unit area were unchanged. Results indicate a dynamic balance between apoptosis and increased DNA synthesis after exposure of mesothelial cells to asbestos.     

Neurofibroma and cellular neurofibroma with atypia: a report of 14 tumors

The clinical significance of nuclear atypia in neurofibromas that lack necrosis or significant mitotic activity has not been systematically studied. We reviewed 14 neurofibromas from six patients with mild to marked nuclear atypia, with low mitotic activity in some tumors. Five tumors also had areas of increased cellularity consistent with cellular neurofibroma. Necrosis was absent. All patients were treated by conservative excision. Clinical follow-up, ranging from 8 months to 6 years, showed that none of the tumors recurred or metastasized. To further characterize these neoplasms, we assessed p53 expression, proliferation rate, and DNA content because these methods have been suggested by others as useful in differentiating benign from malignant nerve sheath tumors. p53 expression was detected by immunostaining in one tumor with 5% positive cells and in two tumors with rare positive cells (<1%). The remaining 11 tumors were negative. Tumor cell proliferation rate as determined by Ki-67 immunostaining showed <5% positive cells in 13 tumors. In one tumor, 10% of the cells were Ki-67 positive. Using flow cytometry methods and paraffin-embedded tissue, all tumors had diploid DNA content with an S phase fraction ranging from 5.2% to 18.2% (mean 9.4%). No significant differences were observed between the neurofibromas and cellular neurofibromas. For comparison, we studied three malignant peripheral nerve sheath tumors (MPNSTs). All MPNSTs had relatively high p53 (range 10-16%; mean 12%) and Ki-67 (range 32-42%; mean 38.0%) staining. One of the MPNSTs was aneuploid. The S phase fraction of the MPNSTs ranged from 8.1% to 51.8% (mean 28.6%). These results suggest that clinically benign neurofibromas, both usual and cellular types, can have significant cytologic atypia that can be accompanied by low mitotic activity. Conservative surgical excision for these tumors is adequate. The results of p53 and Ki-67 immunostaining and DNA content and S-phase analysis by flow cytometry support this interpretation. In addition, in tumors with borderline histologic findings, results of these ancillary studies may be useful in distinguishing benign from malignant nerve sheath tumors.     

Mutagenic and genotoxic activities of four pesticides: captan, foltaf, phosphamidon and furadan

The mutagenic and genotoxic potential of four pesticides viz. captan, foltaf, phosphamidon and furadan was evaluated by the Ames mutagenicity assay and their DNA damaging ability on radiation repair defective E. coli K-12 strains respectively. The mutagenic spectrum revealed captan to be most mutagenic in the absence of metabolic activation, while the presence of S9 mix led to an attenuated mutagenic response. Foltaf, phosphamidon and furadan were detected as relatively weaker mutagens. A significant decrease in the survival of SOS defective mutants, recA, lexA and pol- of E. coli was observed as compared to their wild-type counterparts in the presence of the pesticides. The role of SOS repair genes gains further support from the Salmonella strains triggering the error-prone SOS response.     

Comparison of subcapsular and total orchiectomy for treatment of metastatic prostate cancer

OBJECTIVES: To determine whether subcapsular orchiectomy provides suboptimal treatment of metastatic prostate cancer when used to avoid the psychologic consequences of the empty scrotum that results from total orchiectomy. METHODS: We compared testosterone and prostate-specific antigen levels and survival of 37 patients who underwent total orchiectomy and 37 patients who underwent subcapsular orchiectomy for metastatic prostate cancer. RESULTS: The two groups of 37 patients were similar by clinical parameters. Postoperatively, testosterone levels were 21 +/- 11 ng/dL for subcapsular versus 21 +/- 9 ng/dL for total orchiectomy patients. Tumor response was similar in the two groups when assessed by prostate-specific antigen measured 3 weeks, 6 months, and 1, 2, and 3 years postoperatively. Survival was similar when assessed using Kaplan-Meier analysis (P = 0.76). CONCLUSIONS: Subcapsular orchiectomy is a viable option for treatment of metastatic prostate cancer.     

F-actin sequesters elongation factor 1alpha from interaction with aminoacyl-tRNA in a pH-dependent reaction

The machinery of eukaryotic protein synthesis is found in association with the actin cytoskeleton. A major component of this translational apparatus, which is involved in the shuttling of aa-tRNA, is the actin-binding protein elongation factor 1alpha (EF-1alpha). To investigate the consequences for translation of the interaction of EF-1alpha with F-actin, we have studied the effect of F-actin on the ability of EF-1alpha to bind to aa-tRNA. We demonstrate that binding of EF-1alpha:GTP to aa-tRNA is not pH sensitive with a constant binding affinity of approximately 0.2 microM over the physiological range of pH. However, the sharp pH dependence of binding of EF-1alpha to F-actin is sufficient to shift the binding of EF-1alpha from F-actin to aa-tRNA as pH increases. The ability of EF-1alpha to bind either F-actin or aa-tRNA in competition binding experiments is also consistent with the observation that EF-1alpha's binding to F-actin and aa-tRNA is mutually exclusive. Two pH-sensitive actin-binding sequences in EF-1alpha are identified and are predicted to overlap with the aa-tRNA-binding sites. Our results suggest that pH-regulated recruitment and release of EF-1alpha from actin filaments in vivo will supply a high local concentration of EF-1alpha to facilitate polypeptide elongation by the F-actin-associated translational apparatus.