三氧化二砷纳米微粒对抑制兔血管平滑肌细胞增殖作用的实验研究

目的 了解纳米微粒与普通剂型的三氧化二砷（As2O3）对抑制体外培养的兔血管平滑肌细胞（VSMC）增殖作用的差别。方法 对照组为不加药物的细胞，实验组为3μmol／L纳米微粒和普通剂型的As2O3，干预体外培养的兔VSMC细胞72h，进行四唑氮盐（MTT）染色测定细胞吸光度（A）值。用流式细胞仪检测细胞凋亡情况，提取细胞DNA，进行凝胶电泳分析，将3组的结果进行比较。结果 3μmol／L纳米剂型的As2O3，干预细胞，细胞数量随作用时间的延长逐渐减少，细胞生长明显受抑制，而普通剂型干预细胞，生长受抑制程度较纳米剂型弱。24h时，对照组、3μmol／L普通剂型组与纳米组，A值分别为0．68±0．10、0．58±0．12、0．33±0．12，48h时分别为0．79±0．11、0．48±0．14、0．28±0．11，72h时分别为0．96±0．13、0．34±0．15、0．20士0．06，差异均有统计学意义（Ⅳ值分别为10．934、15．039、15．539，P值均〈0．01）。流式细胞仪检测，纳米剂型As2O3、普通剂型As2O3干预及对照组的细胞干预48h，细胞增殖率分别为44．97％、58．54％、74．02％，早期凋亡率分别为16．89％、11．27％、11．20％，晚期凋亡率分别为26．56％、23．60％、12．46％，坏死细胞分别为11．58％、6．59％、2．32％。DNA电泳，As2O3干预细胞，可见凋亡梯形条带，部分细胞坏死，呈模糊的无间隔片状条带。纳米剂型药物作用的细胞DNA条带，梯形条带更多、更模糊。结论 As2O3，可以抑制体外培养的VSMC增殖，且纳米剂型As2O3较普通剂型的As2O3，对细胞抑制作用更强。     

Delayed expression of NADPH-diaphorase in rat brain after administration of the cholinotoxin AF64A

Administration of cholinotoxin etylcholine aziridinium (AF64A) into the brain selectively induces nonrever-sible cholinergic deficit. Wistar rats were injected intracerebroventricularly bilaterally with AF64A at doses of 1–3 nmol/ventricle. 28 days later the number of neurons survived was counted in dorsolateral, intermediate and medial groups of cells of the medial septum. AF64A induced a decrease in neuronal density and expression of cholineacetyl transferase at all doses used as well as in all regions studied. Brain sections were also stained for NADPH-diaphorase representing neuronal NO-synthase. Effects of AF64A on NADPH-diaphorase expression depended on the region studied. The number of NADPH-diaphorase-positive cells increased in the medial cellular group where more cholineacetly transferase-positive cells survived. In contrast, decrease in NADPH-diaphorase expression in the dorsolateral group of cells coincided with low level of cholineacetyltransferase-po-sitive neurons. The data presented suggest that in the AF64A-dependent model of neurodegeneration NO may play a neuroprotective function.     

General and specific cognitive deficits in schizophrenia.

BACKGROUND: It is controversial whether the cognitive deficit in schizophrenia is better characterized as generalized or as reflecting relatively independent deficits in different cognitive domains. The issue has implications for assessment practice, intervention design, and the exploration of schizophrenia genetics. METHODS: We used a specialized structural equation modeling approach, single common factor analysis, to explore the relative importance of generalized versus independent cognitive deficits in schizophrenia. Eighteen subtest scores from the Wechsler Adult Intelligence Scale-III and the Wechsler Memory Scale-III were included in the analysis. We analyzed these data for 97 schizophrenia or schizoaffective disorder outpatients and 87 healthy control subjects. RESULTS: Approximately two thirds of the overall effect of a schizophrenia diagnosis on cognitive performance was mediated through a single common factor. The Wechsler subtest scores showed almost uniformly strong relationships with this factor. The independent associations of group status with the subtest scores were smaller in magnitude and only selectively significant. CONCLUSIONS: The relatively greater magnitude of illness effects mediated through the common factor in this analysis, compared with the specific, independent effects, suggests that a generalized cognitive deficit is a core feature of schizophrenia.     

The laterally extended medial hemisoleus flap for reconstruction of a tibial wound in the distal third of the leg

A soleus flap as a local reconstructive option for soft-tissue coverage of a tibial wound in the distal third of the leg has never been well recognized. In a 2-year period, seven patients underwent reconstruction of a less extensive tibial wound (4 × 3 to 10 × 4 cm) in the distal third of the leg after orthopedic trauma with the laterally extended medial hemisoleus flap. The flap was elevated with emphasis on the preservation of the most distal perforators from the posterior tibial vessels to the flap as possible while allowing adequate rotation of the flap to cover the exposed tibia and/or hardware and on the possible preservation of foot planter flexion by reconstruction of the proximal Achilles’ tendon. In this series, there was no total or partial flap loss. All patients healed their tibial wounds primarily with reliable soft-tissue coverage, evidenced fracture healing, and good cosmetic outcome during follow-up. Thus, the laterally extended medial hemisoleus flap described by the author can be a reliable option for soft-tissue coverage of a less extensive tibial wound in the distal third of the leg. It offers a more cost-effective approach for managing this unique problem and can be performed by most reconstructive surgeons without microsurgical expertise.     

Fusimotor reflexes to antagonistic muscles simultaneously assessed by multi-afferent recordings from muscle spindle afferents

Several single agonist/antagonist primary muscle spindle afferents were simultaneously recorded in chloralose anaesthetized cats. It was shown that their dynamic and static sensitivity to sinusoidal muscle stretches could be increased or decreased via the fusimotor system by extension and flexion of the contralateral hind limb as well as by stretch of ipsilateral muscles and stimulation of ipsilateral skin nerves. The results seem to support the hypothesis that the primary muscle spindle afferents convey complex multisensory messages to the central nervous system (CNS).     

Extensive pectoral muscle necrosis after defibrillation: nonthermal skeletal muscle damage caused by electroporation

A 37-year-old Italian male developed a myocardial infarct with subsequent ventricular fibrillation. He was defibrillated seven times with up to 360 Joules. Thirteen days later the patient died of recurrent myocardial infarct due to thrombotic occlusion of the left circumflex coronary artery. At autopsy, necrosis of the right pectoralis muscle was observed. Electroporation is the pathogenetic mechanism of skeletal muscle damage due to multiple defibrillations with high energy levels. Received: 8 January 1998 Accepted: 15 April 1998     

Lactate/H+ transport kinetics in rat skeletal muscle related to fibre type and changes in transport capacity

 Lactate/H⁺ transport kinetics were determined by means of the pH-sensitive probe BCECF in sarcolemmal giant vesicles, obtained from rat skeletal muscle, and related to variations in lactate/H⁺ transport capacity. Vesicle preparations were made from red and white muscles, mixed muscles, denervated muscles, muscles of old rats and rats that had been subjected to high-intensity training, endurance training, repeated exposure to hypoxia, and hypothyroid or hyperthyroid treatments. The lactate/H⁺ transport capacity of red muscles was greater than that of white muscles, and this difference was associated with a higher maximal transport rate (V _max) in red muscles, whereas the K _m was similar in the two muscle types. High-intensity training and hyperthyroidism increased the lactate/H⁺ transport capacity by enhancing V _max without affecting K _m. Similarly, a reduced transport capacity with old age and hypothyroidism was due to a decrease in V _max. The denervation-induced decline in lactate/H⁺ transport capacity resulted from both an increased K _m and a reduced V _max. The present data show that muscle type differences and most changes in the lactate/H⁺ transport capacity are mediated by modifications in V _max, which is expected to represent the number of membrane transporter molecules. K _m is unaffected by most treatments and appears to be independent of fibre type. Received: 10 February 1998 / Received after revision: 21 April 1998 / Accepted: 24 April 1998     

断肢断腕断掌再植后手内在肌挛缩51例分析

探讨断肢断腕断掌再植术后手内在肌挛缩的发病机理,结合临床经验提出分类、预防和治疗方法。方法:对51例断肢(腕、掌)再植,分别采用术中切开骨间肌肌筋膜、掌腱膜及腕横韧带;术后严重肿胀时早期切开骨筋膜室;缺血时间超过10小时者,除上述措施外尚须切断或部分切除拇收肌和骨间肌肌腹。结果:采用上述预防措施后,手内在肌挛缩的发生率明显降低。结论:本症重在预防,如能及时、果断地采取措施,效果良好。一旦发生中、重度手内在肌挛缩应尽早手术。     

Respiratory muscle rigidity in a preterm infant after use of fentanyl during Caesarean section

Fentanyl is in many neonatal intensive care units the sedative of choice. One side-effect is, however, the possibility of muscle and/or chest wall rigidity. A pregnant woman with a critical pulmonary valve stenosis had a balloon dilatation at 26 weeks of gestation. She was put on propranolol, but went into a severe cardiac failure. In week 31, she developed pregnancy induced hypertension. Periodically absent diastolic flow in the umbilical cord was demonstrated. A Caesarean section was performed using fentanyl as analgesia. A boy weighing 1440 g, had a 1 min Apgar score of 3 without respiratory movements. Mask ventilation was tried, but chest wall expansion was not achieved despite using high pressures. He was intubated and positive pressure ventilation attempted, with the same result. Despite the use of high pressures up to 60–70 cm H₂O, no chest movement could be achieved. An intravenous line was established in order to give naloxone and pancuronium. Just before the drugs were given, chest wall movements were achieved and the heart rate normalized. Conclusion This is the first report on chest wall rigidity in a neonate after administration of fentanyl to the mother during Caesarean section. Received: 15 August 1997 and in revised form 30 January 1998 / Accepted 3 February 1998