Effect of immunosuppression and splenectomy in transplantation sarcomas in mice

After spontaneous regression of transplanted tumours, marked reduction in number of tumours was found when challenged with isogenic tumour cells. The ALS abrogates this effect. Tumour removal by surgical excision of limb and subsequent time scheduled challenge by tumour cells maximally suppress on the 10th day and continues up to the 42nd day the tumorogenic effect. Splenectomy has no effect if done before a day or 3 days after challenge but marked decrease in tumour development was seen when challenged on the 8th day after splenectomy. Amputation and splenectomy together potentiates tumour formation. Only in tumour extrication, does resistance develop up to the 42nd day from surgery. Challenging at a different site in mice with tumours, resulted in prolongation of the intervals of tumour formation. Challenge after surgical removal of tumour after a time lapse, results in marked reduction in number and size of tumours. Surgical tumour extrication after splenectomy and subsequent challenge on 11th day inhibited tumour formation. Whereas splenectomized tumour bearing mice when challenged at a heterosite did not develop resistance.     

GIS母线中金属异物运动的探讨

介绍GIS母线内部存在金属异物时的影响，对金属异物在不同情况下的运动规律进行了探讨和研究。     

高压自能式灭弧室和操动机构的技术进步(二)

高压SF_6断路器经多次改进在欧洲和日本已发展成第三代产品,第一代为热膨胀式断路器加助吹,将液压机构改为弹簧操动机构和变开距混合式灭弧室。第二代产品为改善开断容性电流特性发展“双容积”灭弧室和新型动态压缩灭弧室,以及双向运行触头系统等,更进一步减少分合闸操作功应用旋弧灭弧原理迫使电弧快速旋转冷却使电流零点时熄灭。第三代产品主要介绍加强操动机构的可靠性和稳定性,传输时无功消耗少,减少机构零件数量等。     

Cervicocephalic kinesthetic sensibility, active range of cervical motion, and oculomotor function in patients with whiplash injury

OBJECTIVE: To investigate cervicocephalic kinesthetic sensibility, active range of cervical motion, and oculomotor function in patients with whiplash injury. DESIGN: A 2-year review of consecutive patients admitted to the emergency unit after whiplash injury. SETTING: An otorhinolaryngology department. PATIENTS AND SUBJECTS: Twenty-seven consecutive patients with diagnosed whiplash injury (14 men and 13 women, mean age, 33.8yrs [range, 18 to 66yrs]). The controls were healthy subjects without a history of whiplash injury. MAIN OUTCOME MEASURES: Oculomotor function was tested at 2 months and at 2 years after whiplash injury. The ability to appreciate both movement and head position was studied. Active range of cervical motion was measured. Subjective intensity of neck pain and major medical symptoms were recorded. RESULTS: Active head repositioning was significantly less precise in the whiplash subjects than in the control group. Failures in oculomotor functions were observed in 62% of subjects. Significant correlations occurred between smooth pursuit tests and active cervical range of motion. Correlations also were established between the oculomotor test and the kinesthetic sensibility test. CONCLUSION: The results suggest that restricted cervical movements and changes in the quality of proprioceptive information from the cervical spine region affect voluntary eye movements. A flexion/extension injury to the neck may result in dysfunction of the proprioceptive system. Oculomotor dysfunction after neck trauma might be related to cervical afferent input disturbances.     

Selective convective brain cooling during normothermic cardiopulmonary bypass in dogs

BACKGROUND: Neurologic complications, primarily resulting from ischemic insults, represent the leading cause of morbidity and disability, and the second most common source of death, after cardiac operations. Previous studies have reported that increases (as occur during the rewarming phase of cardiopulmonary bypass [CPB]) or decreases in brain temperature of a mere 0.5 degrees to 2 degrees C can significantly worsen or improve, respectively, postischemic neurologic outcome. The purpose of the present study was to evaluate a novel approach of selectively cooling the brain during hypothermic CPB and subsequent rewarming. METHODS: Sixteen dogs were anesthetized with either intravenous pentobarbital or inhaled halothane (n = 8 per group). Normocapnia (alpha stat technique) and a blood pressure near 75 mm Hg were maintained. Temperatures were monitored by placing thermistors in the esophagus (i.e., core), parietal epidural space, and brain parenchyma at depths of 1 and 2 cm beneath the dura. During CPB, core temperature was actively cycled from 38 degrees C to 28 degrees C, and then returned to 38 degrees C. Forced air pericranial cooling (air temperature of approximately 13 degrees C) was initiated simultaneous with the onset of CPB, and maintained throughout the bypass period. Brain-to-core temperature gradients were calculated by subtracting the core temperature from regional brain temperatures. RESULTS: In halothane-anesthetized dogs, brain temperatures at all monitoring sites were significantly less than core during all phases of CPB, with one exception (2 cm during systemic cooling). Brain cooling was most prominent during and after systemic rewarming. For example, during systemic rewarming, average temperatures in the parietal epidural space, and 1 and 2 cm beneath the dura, were 3.3 degrees +/- 1.3 degrees C (mean +/- standard deviation), 3.2+/-1.4 degrees C, and 1.6 degrees +/-1.0 degrees C, cooler than the core, respectively. Similar trends, but of a greater magnitude, were noted in pentobarbital-anesthetized dogs. For example, during systemic rewarming, corresponding brain temperatures were 6.5 degrees +/-1.7 degrees C, 6.3 degrees +/-1.6 degrees C, and 4.2+/-1.3 degrees C cooler than the core, respectively. CONCLUSIONS: The magnitude of selective brain cooling observed in both study groups typically exceeded the 0.5 degrees to 2.0 degrees C change previously reported to modulate ischemic injury, and was most prominent during the latter phases of CPB. When compared with previous research from our laboratory, application of cold forced air to the cranial surface resulted in brain temperatures that were cooler than those observed during hypothermic CPB without pericranial cooling. On the basis of the assumption that similar beneficial brain temperature changes can be induced in humans, we speculate that selective convective brain cooling may enable clinicians to improve neurologic outcome after hypothermic CPB.     

Expression and functions of FGF-3 in Xenopus development

We have analyzed the expression pattern of the Xenopus FGF-3 gene during early development and examined its biological activity in three different bioassays using Xenopus embryos. We show that from the early gastrula stage there is a domain of expression around the blastopore which becomes a posterior domain as the blastopore closes. An anterior ectodermal domain becomes detectable from mid-gastrula stages in the prospective hind-brain, and there are several later domains of expression: the midbrain-hindbrain junction, the otocyst, the pharyngeal pouches and the tailbud region. By using double whole-mount in situ hybridizations we show that the XFGF-3 expression in the brain is dynamically regulated both in time and space during development. The anterior domain of early neurula stage embryos corresponds to the prospective rhombomeres 3-5. By the time the neural tube is closed, XFGF-3 expression is restricted to r4 and later a new domain of expression is established at the midbrain/hindbrain junction. In addition, we show that, despite its difference in receptor specificity, XFGF-3 can induce the formation of mesoderm from animal caps similarly to other FGFs. It also displays a posteriorizing activity on whole embryos similar to other FGFs. Although the absence of maternal expression makes it unlikely that XFGF-3 is involved in mesoderm induction in vivo, its posterior domain of expression during gastrulation and its posteriorizing activity suggests that it participates in the maintenance of mesodermal gene expression and in the FGF mediated patterning of the anteroposterior axis during gastrulation.     

Extracorporeal membrane oxygenator support for cardiopulmonary failure. Experience in 28 cases

We have used extracorporeal membrane oxygenation (ECMO) for 28 patients (14 children and 14 adults) over a 5 year period. Nine patients improved on ECMO and 5 were long-term survivors. ECMO was used for pulmonary insufficiency in 24 patients. Initially, only moribund patients were treated, but recently the combination of open lung biopsy and pulmonary insufficiency index (PII) has been used to select patients. The best results have been obtained in newborn cases and the adult capillary leak syndromes; the major problem has been progression to fibrosis despite ECMO support. ECMO was used for cardiac failure in 4 patients. Children with postoperative cardiac failure did the best; profound shock was not reversed with venoarterial bypass. ECMO support is lifesaving in selected cases of pulmonary insufficiency. Initial trials in cardiac failure and the infant age group in this series suggest that ECMO will have an even greater role in those applications.     

Arsenite methylation by methylvitamin B12 and glutathione does not require an enzyme

Although inorganic arsenic is methylated enzymatically by arsenic methyltransferases, which have been found in many mammalian livers, the detection of such enzymes has not been successful in surgically removed human livers. Results of the present experiments demonstrated that methylvitamin B12 (methylcobalamin, CH3B12) in the presence of thiols and inorganic arsenite can produce, in vitro, substantial amounts of monomethylarsonic acid (MMA) and small amounts of dimethylarsinic acid (DMA) in the absence of enzymes. Furthermore, this nonenzymatic methylation of inorganic arsenite by CH3B12 was increased substantially by the presence of dimercaptopropanesulfonate (DMPS) and/or sodium selenite. The actions of DMPS and selenite together were additive. The methylation by CH3B12 was neither inhibited nor stimulated by human liver cytosol. Since the amount of MMA produced by the in vitro system described in this study was not small, these results emphasize the need for a properly designed nutritional study in humans exposed to inorganic arsenic as to the relationship between vitamin B12, selenium, and the metabolism of carcinogenic inorganic arsenic.