Pharmacologic preconditioning effects: Prostaglandin E1 induces heat-shock proteins immediately after ischemia/reperfusion of the mouse liver

Prostaglandin E1 (PGE1) has several potential therapeutic effects, including cytoprotection, vasodilation, and inhibition of platelet aggregation. This study investigates the protective action of PGE1 against hepatic ischemia/reperfusion injury in vivo using a complementary DNA microarray. PGE1 or saline was continuously administered intravenously to mice in which the left lobe of the liver was made ischemic for 30 minutes and then reperfused. Livers were harvested 0, 10, and 30 minutes postreperfusion. Messenger RNA was extracted, and the samples were labeled with two different fluorescent dyes and hybridized to the RIKEN set of 18,816 full-length enriched mouse complementary DNA microarrays. Serum alanine aminotransferase and aspartate aminotransferase levels at 180 minutes postreperfusion were significantly lower in the PGE1-treated group than in the saline-treated group. The cDNA microarray analysis revealed that the genes encoding heat-shock protein (HSP) 70, glucose-regulated protein 78, HSP86, and glutathione S-transferase were upregulated at the end of the ischemic period (0 minutes postreperfusion) in the PGE1 group. Our results suggested that PGE1 induces HSPs immediately after ischemia reperfusion. HSPs might therefore play an important role in the protective effects of PGE1 against ischemia/reperfusion injury of the liver.     

医源性桡神经损伤46例分析

目的阐述医源性桡神经损伤的伤因、治疗和预防措施。方法分析1991年～2003年间收治的46例医源性桡神经损伤的病例。结果伤因分为上肢手术误伤，肱骨干和桡骨上端闭合性骨折复位手法不当，头静脉穿刺致桡神经浅支损伤。本组21例保守治疗，22例手术治疗，3例行肌腱转位功能重建。结论手术误伤是医源性桡神经损伤的首要原因；临床医生丰富的解剖知识和细致、轻柔的操作是预防医源性桡神经损伤的关键。     

肌病肾病代谢综合征治疗进展

肌病肾病代谢综合征是急性动脉阻塞致骨骼肌溶解的严重并发症。积极治疗原发病，及早补液扩容、碱化尿液、早期血液净化治疗是降低截肢率、病死率的关键。本文就肌病肾病代谢综合征治疗进展作一综述。     

Use of epr oximetry with india ink to measure the po2 in the liver in vivo in mice

The partial pressure of oxygen (pO₂) of the liver in vivo in unanesthetized mice was determined using electron paramagnetic resonance (EPR) oximetry with India ink. The EPR spectra were obtained using a low-frequency (1.2 GHz) EPR spectrometer with a loop gap cavity resonator. The line width of the India ink used in this experiment was reversibly broadened by oxygen and was particularly sensitive to pO₂ below 30 torr. After the administration of India ink into the tail vein, the India ink particles were taken up mainly by Kupffer cells in the liver and in part by phagocytes in the spleen. The pO₂ measured in the normal liver was about 14 torr and was constant for the 2-week experimental period. The pO₂ decreased when measured at 1, 2, and 6 days after treatment with a hepatotoxin (carbon tetrachloride (CCI₄)); within 2 weeks, it returned almost to the initial level. Measurements by EPR at sacrifice of controls and CCI₄-treated mice indicated that more than 90% of the India ink went to the liver; the spleen contained 4.7% of total amount in control mice and 8.8% in CCI₄-treated mice when measured 2 weeks after the treatment. These data indicate the usefulness of India ink for measuring the pO₂ of the liver in vivo and that the pO₂ in the Kupffer cells is decreased when the liver is damaged by CCI₄.     

Minor,moderate and severe head injury

Summary The future role of the neurosurgeon in the management of head injury is reviewed in terms of the care of patients with minor, moderate and severe head injuries. In minor head injury it is predicted that there will be increasing pressure on the neurosurgeon to undertake the management and follow-up of all patients who have sustained head injury, and this will place a considerable additional load on each neurosurgical unit. This is based on a survey of 1919 head injuries admitted in one calendar year (1981), consisting of 93 severe injuries (GCS < 8), 210 moderate injuries (GCS 8–12), and 1616 minor injuries (GCS 13/14). In moderate injuries CT will assume a major role in detecting hematoma early and identifying contusions. There may yet be a role for steroids in these cases and there should be a greater use of neurorehabilitation, instead of the current overemphasis on the severely injured. In severe injury future efforts will be to prevent early secondary insults and to find better methods of controlling raised intracranial pressure.     

实验冻伤大鼠神经纤维的超微结构改变

为探讨冷冻损伤发生、发展及转归的规律，采用健康Ｗｉｓｔａｒ大鼠，分为冻伤组（２０只）和对照组（５只）。电镜下观察大鼠后肢冷冻至－２０℃后即刻、４小时、２４小时及７２小时时周围神经的超微结构改变。冻后即刻，神经髓鞘即出现轻度变性；冻后１～２４小时，有髓神经雪旺细胞及轴突严重变性，而无髓神经变性较轻；冻后７２小时，神经溃变及修复并存，无髓神经较有髓神经易于修复。     

All-trans retinoic acid suppresses liver injury induced by Propionibacterium acnes and lipopolysaccharide in rats

All-trans retinoic acid (ATRA) has been reported to exert major effects on the immune system, including monocytes/macrophages. The present study was designed to determine whether ATRA would modulate macrophage-associated liver injury induced by Propionibacterium acnes and lipopolysaccharide (LPS) in rats. All-trans retinoic acid administration alleviated the liver injury and reduced the incidence of death following hepatic failure. Serum alanine aminotransferase (ALT) levels 5 h after, and survival rates within 12 h after the administration of LPS were significantly lower in the ATRA-treated group (134 ± 119 IU/L and 72.7%) compared with the control group (713 ± 411 IU/L and 18.2%; P < 0.05). Histological findings supported these results. These effects may be due to suppression of tumour necrosis factor-α (TNF-α) and superoxide anions produced by activated macrophages. Serum levels of TNF-α 1 h after LPS administration were significantly lower in the ATRA-treated group (60.5 ± 7.0 ng/mL) as compared with the control group (105.2 ± 39.3 ng/mL; P < 0.05). Formazan deposition that was generated by the perfusion of the liver with nitroblue tetrazolium, also suggested suppression of the release of superoxide anions from hepatic macrophages. These results suggest that ATRA acts as an immunomodulator in liver injury by suppressing the activation of liver macrophages.     

Attitudes of College Football Officials Regarding NCAA Mouthguard Regulations and Player Compliance

The National Collegiate Athletic Association (NCAA) mandates the use of brightly colored, intraoral mouth- guards by football players to reduce the frequency and severity of craniofacial and intraoral morbidity and mortality, and to enhance the ability of officials to observe player compliance. The purpose of this 12-question mail survey was to determine the attitudes of on-Held game officials regarding current NCAA mouthguard regulations and patterns of utilization by college football players. The sample consisted of all 50 Big East Football Conference officials; a response rate of 100 percent was achieved. Only 42 percent of the officials reported observing all players in compliance, and quarterbacks were identified by others as the least compliant group (52%). The majority (88%) indicated that the 1990 rule for brightly colored mouthguards had been beneficial to them in determining player compliance, and 52 percent reported that this rule had resulted in more frequent use by these athletes. Nearly all officials (96%) indicated that they would issue a warning for noncompliance to the player or coach, rather than charging a timeout for a violation as prescribed by NCAA regulations. The majority (70%) believe current enforcement is appropriate, but expressed the opinion that coaches should be held more accountable for player compliance.