Paracetamol absorption from a feeding jejunostomy.

Disposition of paracetamol oral elixir was determined in two male patients after administration via feeding jejunostomy and compared with four male controls who received the same dose by mouth. Area under the plasma concentration-time curve, elimination half-life, and time to maximum concentration were similar in both groups after 650 mg paracetamol elixir. The absolute amounts and ratio of paracetamol glucuronide to sulphate, the major urinary metabolites after therapeutic paracetamol doses, were similar after jejunal administration as compared to oral administration. Paracetamol is absorbed and biotransformed in a similar manner after either jejunal or oral administration. Therefore, it may be administered effectively via jejunostomy tube in patients who require this route of administration.     

Elaboration by mammalian mesenchymal cells infected with Trypanosoma cruzi of a fibroblast-stimulating factor that may contribute to chagasic cardiomyopathy.

Myocardial fibrosis can occur as a complication of chronic infection of the heart with Trypanosoma cruzi (Chagas' disease) and can lead to serious disability. To assess whether there might be a direct relationship between intracellular parasitization and subsequent tissue fibrosis in this disease, we tested serum-free conditioned media from cultures of fibroblasts, vascular smooth-muscle cells, and myocardial cells for fibroblast-stimulating activity. Conditioned media from all infected cultures, but not from uninfected cultures, stimulated fibroblast [3H]thymidine incorporation, DNA and protein synthesis, and cell proliferation. Fibroblast-stimulating activity was also detected in extracts of amastigotes but not of trypomastigotes or epimastigotes. We conclude that parasitization of mesenchymal cells, including myocardial cells, results in elaboration of a fibroblast-stimulating factor(s), perhaps of parasite origin. We postulate that this factor may play a role in initiation of myocardial fibrosis in Chagas' disease.     

地塞米松对布比卡因诱导小鼠神经元毒性的影响

Objective To investigate the effect of dexamethasone on the toxicity of bupivacaine in murine neurons.Methods Murine neuroblastoma cell line N2a was obtained from ATCC cell bank (USA). The cells were cultured in 10% fetal cow serum/MEM culture medium and divided into 4 groups voup I control (Con); group II bupivacaine ( Bup); group Ⅲ dexamethasone (Dex) and group IV Dex + Bup. The culture medium contained bupivacaine 900 μmol/L in group Bup and dexamethasone 1 μmol/L in group Dex respectively. In group Dex + Bup ( IV ) Bup was added to the culture medium with a final concentration of 900 μmol/L at 12 h after pretreatment with Dex 1 μmol/L. The cells were inoculated in 24 well plates (0.5 ml in each well, 24 wells in each group) and 10 cm culture dishes (7 ml in each dish, 4 dishes in each group). The release rate of LDH was calculated and the morphology of the cells and nucleus condensation (by Hoechst 3334224 fluorescent staining) was detected at 9 h of incubation in 24 well plates. The mitochondrial transmembrane potential (by JC-1 assay) and phosphorylation of Akt and ERKs (by Western blot) were measured at 5 h of incubation in 24 well plates and in culture dishes respectively. ResultsBupivacaine caused severe damage to the N2a cells as evidenced by increase in LDH release and nucleus condensation (apoptosis), dephosphorylation of Akt and ERKs, decrease in mitochondrial transmembrane potential and severe morphological changes. Dexamethasone pretreatment significantly attenuated bupivacaine-induced neurotoxicity. Conclusion Dexamethasone can protect N2a cells from bupivacaine-induced neurotoxicity through stabilization of mitochondrial transmembrane potential and inhibition of dephosphorylation of Akt and ERKs.     

尿激酶溶栓对急性心肌梗死患者单核细胞组织因子表达的影响

目的 :了解冠心病患者外周循环单核细胞组织因子 (TF)表达与冠心病病情的关系 ;观察溶栓治疗对急性心肌梗死患者单核细胞TF表达的影响。方法 :测定了 2 2例稳定型心绞痛 (SA)患者 ,2 1例不稳定型心绞痛(UA)患者 ,1 5例急性心肌梗死 (AMI)患者用尿激酶溶栓前及溶栓后 ,1 8例健康人外周循环单核细胞组织因子阳性率。单核细胞组织因子阳性率测定用免疫荧光染色及流式细胞术。结果 :SAP组 ,UAP组和AMI组单核细胞TF阳性率高于对照组 ,UAP组和AMI组单核细胞TF阳性率高于SAP组 ,单核细胞TF阳性率与冠心病病情显著相关。急性心肌梗死患者溶栓后 2h单核细胞TF阳性率升高。结论 :外周血单核细胞TF的表达与冠心病病情严重程度密切相关 ;急性心肌梗死患者溶栓治疗后单核细胞TF的表达进一步增强 ,这可能是溶栓后凝血酶活化的原因之一。     

Changing attentional demands in left hemispatial neglect.

Seven variations of a letter cancellation test were used to examine how varying attentional demands affect hemispatial neglect in patients with right hemisphere lesions. While the 14 targets always remained in the same location, the number of distractors (zero, nine, 28, or 82) as well as their complexity (one letter or nine different letters) were varied. The percentage of targets canceled in the left hemispace was linearly related to the number of distractors. There were no differences between the complexity conditions. In a second study, the same 14 targets were presented but the distractors (zero, 14, or 41) were all placed on the right. Increasing the number of distractors on the right increased neglect on both sides of the space. Taken together, these results suggest that, while the limited attentional resources of the left hemisphere are biased toward the right hemispace, the absence of contralateral attentional demands allows these resources to be directed ipsilaterally.     

Familial expansile osteolysis: a morphological, histomorphometric and serological study.

Biopsies from the diseased bones of patients with familial expansile osteolysis (FEO) were examined by light and electron microscopy. Focal concentrations of multinuclear osteoclasts were present, and these contained viral-like microcylindrical inclusions which appeared exclusive to their nuclei. No consistent relationship was found between osteoclast size and the number of osteoclast nuclei containing microcylindrical inclusions. Quantitative histomorphometry showed evidence of increased bone remodelling with high bone cell densities and a decrease of the reversal period in bone remodelling. The lesions contained prominent woven bone and fibrovascular tissue, together with mononuclear cells and adipocytes. Little bone was found in the most radiolucent lesions, which were almost totally occupied by adipocytes and fibrovascular tissue. Serology did not reveal any significant differences between the viral antibody titres of patients and their age- and sex-matched controls. The present study suggests that intranuclear viral-like microcylindrical inclusions of osteoclasts are not a specific feature of Paget's disease, and are found in other disorders of osteoclast function, including pycnodysostosis, osteopetrosis, giant cell tumours, and familial expansile osteolysis.