TNF alpha and Fas mediate tissue damage and functional outcome after traumatic brain injury in mice.

Tumor necrosis factor-alpha (TNFalpha) and Fas are induced after traumatic brain injury (TBI); however, their functional roles are incompletely understood. Using controlled cortical impact (CCI) and mice deficient in TNFalpha, Fas, or both (TNFalpha/Fas-/-), we hypothesized that TNFalpha and Fas receptor mediate secondary TBI in a redundant manner. Compared with wild type (WT), TNFalpha/Fas-/- mice had improved motor performance from 1 to 4 days (P<0.05), improved spatial memory acquisition at 8 to 14 days (P<0.05), and decreased brain lesion size at 2 and 6 weeks after CCI (P<0.05). Protection in TNFalpha/Fas-/- mice from histopathological and motor deficits was reversed by reconstitution with recombinant TNFalpha before CCI, and TNFalpha-/- mice administered anti-Fas ligand antibodies had improved spatial memory acquisition versus similarly treated WT mice (P<0.05). Tumor necrosis factor-alpha/Fas-/- mice had decreased the numbers of cortical cells with plasmalemma damage at 6 h (P<0.05 versus WT), and reduced matrix metalloproteinase-9 activity in injured brain at 48 and 72 h after CCI. In immature mice subjected to CCI, genetic inhibition of TNFalpha and Fas conferred beneficial effects on histopathology and spatial memory acquisition in adulthood (both P<0.05 versus WT), suggesting that the beneficial effects of TNFalpha/Fas inhibition may be permanent. The data suggest that redundant signaling pathways initiated by TNFalpha and Fas play pivotal roles in the pathogenesis of TBI, and that biochemical mechanisms downstream of TNFalpha/Fas may be novel therapeutic targets to limit neurological sequelae in children and adults with severe TBI.     

Attitudes towards mental illness: testing the contact hypothesis among Chinese student nurses in Hong Kong

This study investigated whether previous contact with mental illness affected the attitudes to mental illness (AMI) of general student nurses in Hong Kong — the contact hypothesis. We employed a quasi-experimental design. We compared the attitudes to mental illness of students who had previous contact with mental illness through having taken a psychiatric secondment with those who had not taken a psychiatric secondment. Also, we compared the AMI of: students who had taken other courses related to mental illness with those who had not; those who had a family history of mental illness with those who had not; and those who lived with a mentally ill relative with those who did not. We found that previous contact with mental illness had no significant effect on the attitudes to mental illness of the students. In other words our findings do not support the contact hypothesis. Our sample expressed positive general attitudes to mental illness when presented with general issues about mental illness. However, their attitudes were less positive when presented with specific issues about mental illness that might impinge upon their daily lives. We discuss the implications of these findings for mental health nursing practice, education and research.     

Posterior beam-stop method for scatter fraction measurement in digital radiography.

The authors presented a new posterior beam-stop (PBS) technique for measuring the ratio of scattered to total-detected photon flux (scatter fraction) in a radiographic examination while preserving the diagnostic quality of the image. The scatter measurement was made using a standard imaging geometry with both beam stops and an additional x-ray detector placed behind the standard imaging detector. This PBS geometry differs from the standard beam-stop (SBS) technique for scatter measurement. With SBS, a beam-stop shadow appears on the image. To evaluate the PBS technique, scatter fraction measurements were performed on an anatomic phantom using both the PBS and SBS techniques. When compared with the standard technique, PBS provided accurate estimation of scatter fractions. Since the measurement can be performed without degrading a standard clinical radiographic examination, the PBS technique allows simultaneous acquisition of scatter measurements from human patients in combination with a standard radiographic examination.     

Effect of exercise on repetitive nerve stimulation studies: new appraisal of an old technique.

Repetitive nerve stimulation (RNS) is a simple and rapid method for evaluation of neuromuscular transmission defects. Although the effect of exercise in conjunction with RNS is well recognized, it has not been standardized in actual patient and control groups. In a prospective study over a period of 1 year, the authors evaluated the effect of exercise in conjunction with RNS in comparison with conventional 3-Hz RNS at rest in the clinical setting. Fifty-four patients who were referred for possible neuromuscular transmission disorders, in addition to 35 healthy control subjects, were studied. Amplitude and area decremental responses with RNS at rest and after 20 seconds of maximal exercise at 1-minute intervals up to 3 minutes were evaluated. The use of RNS with exercise resulted in additional diagnostic yield of up to 36.4% compared with conventional 3-Hz RNS at rest. The standardized use of exercise with RNS is advocated for increasing its diagnostic yield in the neurophysiologic laboratory.     

Acute pseudo-obstruction of the colon following partial splenic artery embolization: report of a case.

This is a case of a 45-year-old woman suffering from liver cirrhosis with hypersplenism who received a partial splenic artery embolization with gelfoam pieces. Thrombocytopenia and leukopenia improved immediately after treatment. Marked abdominal distention, metallic bowel sounds and combined small and large bowel distension with air-fluid levels as shown on a plain abdominal X ray were noted on the fifth day after the embolization procedure. Laparotomy was performed. No mechanical obstruction was found during surgery. Acute pseudo-obstruction of the colon (Ogilvie's syndrome) was diagnosed. This condition was considered to be a complication of the partial splenic artery embolization and has not hitherto been reported.     

传染病研究40年（1955～1995年）

本文综述本校传染病学教研室１９５５～１９９５年间所取得的科研成果。内容包括１０余种传染病与寄生虫病的临床和基础研究，其中以华支睾吸虫病、恙虫病等有广东特色的传染病以及伤寒、痢疾、病毒性肝炎等影响人民健康最普遍的传染病为重点。反映了建国以来各个时期本教研室对防治这些传染病所作的贡献。所取得的成果，相当一部分通过多年来的验证，已获得广大传染病工作者所认同或列为常规，部分已获得部委级奖励。现在重温这些成果，可能起承前启后的意义。     

Astrocytic induction of matrix metalloproteinase-9 and edema in brain hemorrhage.

We tested the hypothesis that astrocytic matrix metalloproteinase-9 (MMP-9) mediates hemorrhagic brain edema. In a clinical case of hemorrhagic stroke, MMP-9 co-localized with astrocytes and neurons in peri-hematoma areas. In a mouse model where blood was injected into striatum, MMP-9 was colocalized with astrocytes surrounding the hemorrhagic lesion. Because MMP-9 is present in blood as well as brain, we compared four groups of wild type (WT) and MMP-9 knockout (KO) mice: WT blood injected into WT brain, KO blood into KO brain, WT blood into KO brain, and KO blood into WT brain. Gel zymography showed that MMP-9 was elevated in WT hemorrhagic brain tissue but absent from KO hemorrhagic brain tissue. Edematous water content was elevated when WT blood was injected into WT brain. However, edema was ameliorated when MMP-9 was absent in either blood or brain or both. To further assess the mechanisms involved in astrocytic induction of MMP-9, we next examined primary mouse astrocyte cultures. Exposure to hemoglobin rapidly upregulated MMP-9 in conditioned media within 1 to 24 h. Hemoglobin-induced MMP-9 was reduced by the free radical scavenger U83836E. Taken together, these data suggest that although there are large amounts of MMP-9 in blood, hemoglobin-induced oxidative stress can trigger MMP-9 in astrocytes and these parenchymal sources of matrix degradation may also be an important factor in the pathogenesis of hemorrhagic brain edema.