Changes in MAP2 and clathrin immunoreactivity were studied in gerbil hippocampus after transient cerebral ischemia. MAP2 immuno-reactivity decreased significantly by 1 h in the subiculum-CA1 and CA2 areas which correspond to reactive change, while no decrease was observed in CA1 until day 4. Before the initiation of delayed neuronal death, MAP2 immunoreactivity was not changed in CA1. On the other hand clathrin immunoreactivity increased in the pyramidal cell layer of CA1 by 3 h after ischemia and remained high for 2 days. Clathrin immunoreactivity in the pyramidal cell layer of CA1 diminished after delayed neuronal death. The transient change of clathrin was noted especially in CA1 in the period prior to delayed neuronal death. These results imply an abnormal change in clathrin turnover after ischemia, which may participate in the pathogenesis of delayed neuronal death. 相似文献
Background: Ketamine has been shown to suppress platelet aggregation, but its mechanisms of action have not been defined. The purpose of the current study is to clarify the effects of ketamine on human platelet aggregation and to elucidate the underlying mechanisms of its action.
Methods: Platelet aggregation was measured using an eight-channel aggregometer, and cytosolic free calcium concentration was measured in Fura-2/AM-loaded platelets using a fluorometer. Inositol 1,4,5-triphosphate (IP3) was measured with use of a commercially available IP3 assay kit. To estimate thromboxane A2 (TXA2) receptor binding affinity and expression, Scatchard analysis was performed using [3H]S145, a specific TXA2 receptor antagonist. TXA2 agonist binding assay was also performed. The membrane-bound guanosine 5'-triphosphatase activity was determined using [[gamma]-32P]guanosine triphosphate by liquid scintillation analyzer.
Results: Ketamine (500 [mu]m) suppressed aggregation induced by adenosine diphosphate (0.5 [mu]m), epinephrine (1 [mu]m), (+)-9,11-epithia-11,12-methano-TXA2 (STA2) (0.5 [mu]m), and thrombin (0.02 U/ml) to 39.1 +/- 30.9, 46.3 +/- 4.3, -2.0 +/- 16.8, and 86.6 +/- 1.4% of zero-control, respectively. Ketamine (250 [mu]m-1 mm) also suppressed thrombin- and STA2-induced cytosolic free calcium concentration increase dose dependently. Although ketamine (2 mm) had no effect on TXA2 receptor expression and its binding affinity, it (1 mm) suppressed intracellular peak IP3 concentrations induced by thrombin and STA2 from 6.60 +/- 1.82 and 4.39 +/- 2.41 to 2.41 +/- 0.98 and 1.90 +/- 0.86 pmol/109 platelets, respectively, and it suppressed guanosine triphosphate hydrolysis induced by thrombin (0.02 units/ml) and STA2 (0.5 [mu]m) to 50.3 +/- 3.2 and 67.5 +/- 5.5%versus zero-control, respectively. 相似文献
SeveralChlorellavirus CVK2 proteins had chitosanase and/or chitinase activities. A gene coding for an ORF of 328 amino acids (aa) with a predicted molecular mass of 36,769 Da was cloned from the viral genome. The predicted amino acid sequence of an N′-portion (174 aa) of this gene product (vChta-1) showed 22 to 25% identity with various bacterial chitosanases. A glutathioneS-transferase (GST)–vChta-1 fusion protein had strong chitosanase activity. Western blot analysis with antisera raised against the vChta-1 protein identified two proteins of 37 and 65 kDa in virus-infectedChlorellacells beginning at 240 min postinfection and continuing until cell lysis. The larger protein was packaged in the virion, while the smaller one remained in the cell lysate. Both chitosanase proteins were produced from the single gene,vChta-1,by a mechanism of alternative gene expression. 相似文献
Forty-nine pathologically proven gallbladder lesions were evaluated in 45 patients using dynamic MRI with a spoiled gradient pulse sequence (SPGR), to access the ability of this technique to differentiate benign from malignant gallbladder lesions. The studies were reviewed retrospectively. Signal intensity of the lesions were measured. Twenty-one malignant and 28 benign lesions were classified into three categories: polypoid, diffuse wall thickening, and exophytic. Early and delayed enhancement patterns were evaluated. For the polypoid masses, malignant lesions (n = 9) demonstrated early and prolonged enhancements, whereas benign lesions (n = 14) had early enhancement with subsequent washout (P < .05). For diffuse gallbladder wall thickening, malignant lesions (n = 6) demonstrated early and prolonged enhancement and benign lesions (n = 14) showed relatively slow, prolonged enhancement (P < .05). The exophytic masses (n = 6) all were malignant and demonstrated early and prolonged enhancement. Dynamic MRI can help differentiate benign from malignant gallbladder lesions. 相似文献
Bistropolone derivatives (4-12) containing differing lengths of linkage between the two tropolone rings were prepared and examined for their antitumor activity in in vitro (KB cell) and in vivo (leukemia P388 in mice) systems. Parent compound 3, related compounds previously prepared, and the new compounds 4-12 were evaluated for inhibitory activity against ribonucleotide reductase by indirect means to measure their effects on the dNTP pool imbalance. Present structure-activity relationship results would suggest that potently active bistropolones in vivo inhibit intracellular ribonucleotide reductase through chelating with the two irons at the two active sites of the enzyme. 相似文献
We evaluated a 1-year course of a newly developed immunosuppressant, mizoribine (at a dosage of 3 mg/kg body weight per day),
in nine children with steroid-dependent nephrotic syndrome. Steroid treatment could be discontinued in two patients and the
maintenance dosage of steroid could be reduced to less than half of that given before mizoribine therapy in a third. There
were no beneficial effects in the remaining six patients. No adverse effects of mizoribine were observed during the course
of therapy.
Received September 20, 1996; received in revised form and accepted April 24, 1997 相似文献
This study was designed to determine the influence of ileal pouch capacity and anal sphincteric function on the clinical outcome
after ileal pouch-anal anastomosis. A total of 24 patients who had undergone ileal pouch-anal anastomosis (J pouch) for ulcerative
colitis were studied. The 24-hour stool frequency was found to be inversely correlated with the sensitivity threshold volume
(STV), maximal tolerance volume (MTV), and distensibility, but was independent of the maximal resting pressure and maximal
squeeze pressure. Patients experiencing nocturnal fecal incontinence had maximal resting pressures that were significantly
lower than those of nocturnally continent patients. Among the patients with fecal incontinence, those with frequent soiling
had lower resting pressures, STV, and distensibility than the patients with intermittent spotting. In addition, the STV in
patients needing nocturnal evacuation were lower than those of patients who did not evacuate after falling asleep. The conclusions
are as follows. Both stool frequency and the need for nocturnal pouch evacuation correlated directly with pouch volume. Anal
incontinence was more common in patients with low internal sphincteric function. In addition, frequent and gross nocturnal
incontinent patients demonstrate a worse function in both the anal sphincter and reservoir than those with intermittent spotting. 相似文献
We describe the case of a 61-year-old woman diagnosed with primary Sj?gren's syndrome (SS) after an 8-year history of IgA nephropathy and a 3-year history of recurrent purpuric rashes. Her two daughters had previously been diagnosed with other autoimmune diseases. One daughter had Graves' disease and the other had Hashimoto's disease and systemic lupus erythematosus. The diagnosis of SS was made based on dryness of mucous membranes, Shirmer test, and parotid sialography. Thrombocytopenia, high platelet-aggregated IgG (PA-IgG) level, and normal megakaryocytes count in bone marrow suggested that her recurrent purpuric rashes were due to idiopathic thrombocytopenic purpura (ITP). Patients with SS may develop other autoimmune diseases. This case aids understanding of the immune pathogenesis and genetic background of SS. 相似文献