滨蒿内酯对豚鼠气管平滑肌细胞细胞内钙离子浓度的影响

目的：探讨滨蒿内酯（Scop)松弛豚鼠气管平滑肌的机制。方法：进行豚鼠气管平滑肌细胞分离。通过负荷钙离子荧光指示剂fluor-3-AM进行[Ca^2 ]i测定。结果：Scop可直接降低豚鼠气管平滑肌[Ca^2 ]ii，并且能抑制磷酸组织胺（His)和咖啡因（caffeine)对气管平滑肌[Ca^2 ]i的升高作用。结论：Scop松弛豚鼠气管平滑肌的主要作用机制是抑制细胞内钙浓度水平。     

Reduction of prefrontal cortex glucose metabolism common to three types of depression

Using positron emission tomography, we studied cerebral glucose metabolism in drug-free, age- and sex-matched, right-handed patients with unipolar depression (n = 10), bipolar depression (n = 10), obsessive-compulsive disorder (OCD) with secondary depression (n = 10), OCD without major depression (n = 14), and normal controls (n = 12). Depressed patients were matched for depression on the Hamilton Depression Rating Scale, and subjects with OCD without depression and OCD with depression had similar levels of OCD without depression and OCD with depression had similar levels of OCD pathology. We also studied six non-sex-matched patients with mania. Mean (+/- SD) glucose metabolic rates for the left dorsal anterolateral prefrontal cortex, divided by the rate for the ipsilateral hemisphere as a whole (ALPFC/hem), were similar in the primary depressions (unipolar depression = 1.05 +/- 0.05; bipolar depression = 1.04 +/- 0.05), and were significantly lower than those in normal controls (1.12 +/- 0.06) or OCD without depression (1.15 +/- 0.05). Results for the right hemisphere were similar. Values in subjects with OCD with depression (1.10 +/- 0.05) were also significantly lower than in subjects with OCD without depression, and values in subjects with bipolar depression were lower than those in manic subjects (1.12 +/- 0.03) on this measure in the left hemisphere, although results were not significant in the right hemisphere. There was a significant correlation between the HAM-D score and the left ALPFC/hem. With medication for depression (n = 12), the left ALPFC/hem increased significantly and the percentage change in the Hamilton scale score correlated with the percentage change in the left ALPFC/hem.(ABSTRACT TRUNCATED AT 250 WORDS)     

Immuno-electron microscopical demonstration of lysosomes in human blood platelets and megakaryocytes using anti-cathepsin D

Immunocytochemistry with affinity-purified anti-human cathepsin D was applied to ultrathin frozen sections of human bone marrow megakaryocytes and of blood platelets from peripheral blood. The fixative used was paraformaldehyde (concentration gradient 2----8%). Protein A/colloidal gold (5 and 8) particles were used as second label. Cathepsin D was localized in primary and secondary lysosomes in blood platelets and in primary and secondary lysosomes in megakaryocytes. Primary lysosomes in megakaryocytes were identified by their localization on the trans-side of the Golgi complex and secondary lysosomes by the presence of inclusions. The lysosomes in platelets differed from alpha-granules by being smaller, lacking an electron dense core, and by the presence of a transparent submembrane halo. Platelets undergoing a release reaction after stimulation with thrombin showed cathepsin-D staining in the surface-connecting tubules.     

The role of glutathione reductase in maintaining human granulocyte function and sensitivity to exogenous H2O2

Human granulocytes (polymorphonuclear leukocytes, PMN) produce H2O2 and other reactive oxygen species while undergoing phagocytosis. To examine the role of the glutathione cycle in metabolizing H2O2, we incubated PMN with 1,3-bis (2-chloroethyl) nitrosourea (BCNU). Incubation of PMN with BCNU results in a dose-dependent inhibition of PMN glutathione reductase (GRED), with 50% inhibition occurring at approximately 2 micrograms/mL BCNU. PMN hexose monophosphate shunt activity stimulated with an exogenous H2O2-generating system was inhibited only when the GRED activity was reduced to less than 30% of control. BCNU-treated cells contained lower levels of reduced sulfhydryls and reduced glutathione, which decreased even more in the presence of an exogenous H2O2-generating system. The effect of BCNU and exogenous H2O2 on various aspects of phagocytosis were examined. Exposure of BCNU-treated PMN to an H2O2-generating system resulted in an inhibition of chemotactic peptide-induced shape changes and degranulation. The ability of BCNU-treated cells to produce O2- was diminished only when the PMN were incubated with an H2O2-generating system in the presence of cyanide. Ingestion of opsonized bacteria by BCNU-treated PMN was unaffected by incubation in an H2O2-generating system even in the presence of cyanide. We conclude that PMN GRED is inhibited by BCNU, the ability of PMN to metabolize H2O2 is affected only when GRED is reduced more than 70%, this inhibition affects the glutathione content of these cells, and some, but not all of the phagocytic functions of GRED-inhibited PMN are inhibited after exposure to an H2O2-generating system.     

Cell cycle analysis using bromodeoxyuridine: comparison of methods for analysis of total cell transit time

Results are presented supporting the study of cellular proliferation utilizing 5-bromodeoxyuridine (BrdU) incorporation followed by sister chromatid differential staining. In order to determine the relative accuracy of this method in estimating total cell transit time (TC), we utilized a thermosensitive rat embryonic cell line to compare measurement of TC based on the percent differentially labeled (PDLM) technique, with cell cycle measurements using [3H]-thymidine [( 3H]-TdR) incorporation and the percent labeled mitoses (PLM) technique. Results of PLM and PDLM analysis were shown to be highly concordant, indicating the utility of the BrdU method for analysis of Tc. Results are presented suggesting the general application of the PDLM method for estimations of TC in cultures of human tumors.