大剂量甲氨蝶呤在预防儿童中枢神经系统白血病中的作用

目的：探讨大剂量甲氨蝶呤（ＨＤＭＴＸ）对预防儿童急性淋巴细胞白血病（ＡＬＬ）所致中枢神经系统白血病（ＣＮＳＬ）的作用。方法：１２例患儿ＭＴＸ剂量按３．０ｇ／ｍ２计算，总量１／３加等渗盐水３０ｍｌ于３０ｍｉｎ内静脉推注，余２／３量加入１０％葡萄糖１５００～２０００ｍｌ中２４ｈ静滴，结束后鞘内注射ＭＴＸ加地塞米松１次，２４ｈ后应用四氢叶酸钙解救，剂量为每次１２ｍｇ／ｍ２，每６ｈ肌注１次，共６～８次。结果：血清ＭＴＸ的最高浓度为（０．８７～１．２３）×１０－４ｍｏｌ／Ｌ，用药２４ｈ后有效浓度仍在（１．０～７．０）×１０－７ｍｏｌ／Ｌ范围内。脑脊液的ＭＴＸ浓度在（２．０～８．８）×１０－７ｍｏｌ／Ｌ，足以杀灭中枢内白血病细胞，除１例出现严重中毒外，其余病例不良反应均较轻。９例坚持治疗１８个月，除１例复发外，８例连续完全缓解。结论：ＨＤＭＴＸ治疗有利于减少患儿ＡＬＬ的发复，有提高长期无病生存率的作用     

Formalin-evoked Fos expression in spinal cord is enhanced in morphine-tolerant rats

It has been hypothesized that tolerance to the analgesic effects of morphine results from the development of a compensatory response in neurons that express the opioid receptor or in neural circuits in which those neurons participate. The compensatory response establishes a sensitized state in these neurons. To determine if administration of a noxious stimulus can unmask a sensitization of dorsal horn neurons in morphine-pelleted rats, we injected morphine-tolerant and control rats with formalin into the plantar surface of the hindpaw, counted the number of flinches for 2 h and then processed the lumbar cord for Fos immunocytochemistry. Although there was no significant difference in flinching behavior between the morphine-tolerant and control groups, we recorded significantly increased total Fos-like immunoreactivity at the L4/5 and L2 segments both ipsilateral and contralateral to the site of formalin injection in the morphine-tolerant rats compared to the control rats. These results suggest that lumbar spinal cord neurons are sensitized during the development of tolerance, that the sensitization can be unmasked by the administration of a noxious stimulus and that it is manifested as increased expression of the Fos protein in the lumbar cord.     

Lesions of the central gray block the sensitization of the acoustic startle response in rats

The amplitude of the acoustic startle response (ASR) in rats is increased after administration of footshocks, a phenomenon termed sensitization. The neural circuitry underlying this kind of modulation of the ASR is only partly understood. It has been shown that the central nucleus of the amygdala (cA) and its efferent pathway to the caudal pontine reticular nucleus (PnC), an essential part of the primary startle circuit, is important for the sensitization of the ASR [23]. It was unclear, however, whether the amygdaloreticular pathway directly transfers the effects of footshocks onto the PnC, or whether there exists a relay nucleus within this pathway. The present study tested the hypothesis that the midbrain central gray (CG) is important for the sensitization of the ASR. Neuroanatomical tracing experiments indicate that a descending projection from the medial part of the cA might form synapses in the region of the midbrain CG, where a descending projection to the PnC takes its origin. We lesioned the dorsal and lateral part of the CG with the neurotoxin quinolinic acid and measured the effects of this lesion on the sensitization of the ASR by footshocks. Lesions confined to the dorsal and lateral parts of the CG totally blocked the sensitization of the ASR, without affecting the ASR amplitude in the absence of sensitizing stimuli. These findings suggest a crucial role of the CG for the sensitization of the ASR. The present data are reconciled with other findings from our laboratory and from the literature and we discuss possible mechanisms underlying the mediation of the sensitization of the ASR in rats.     

医院施行会员制的探讨

随着医疗制度的改革和医疗保险制度的建立，病人的自费份额比重增大，病人对医疗价格十分敏感，在医疗水平、医护质量相差不大的情况下，病人主要是根据医疗价格选择医院。采用低价位经营固然能够赢得部分医疗市场，同时也会影响到医院的经济收入和效益。施行会员制既能赢得市场份额又不会造成损失，是一种先进的医院经营方式。它是将商业系统普遍实用的会员制移植到医院中来，利用对会员实行优惠的方式确保医院有稳定的病员群体，靠这一部分稳定的群体保持扩大医院的影响力，吸引更多病人到医院就诊     

Chronic variable stress induces supersensitivity of central α2-adrenoceptors which modulate the jaw-opening reflex in the rat

In a previous study, we found that the sensitivity of central postsynaptic α₂-adrenoceptors which modulate, in an inhibitory way, the activity of the jaw-opening reflex (JOR) is reduced after chronic repeated stress (tail pinch) in the rat. The aim of this study was to assess the effects of exposure to a chronic variable stress regime on these adrenoceptors. To do this, the digastric electromyographic responses elicited by orofacial electrical stimulation after the intravenous administration of cumulative doses (×3.3) of the α₂-adrenoceptor agonist, clonidine (0.1–10 000 μg/kg), were recorded. As expected, in unmanipulated control rats, clonidine inhibited the reflex, in a dose-dependent manner, until abolition (ED₅₀=17.3±2.2 μg/kg). Single tail pinch did not significantly alter the ability of clonidine to abolish the reflex. However, chronic variable stress led to an enhancement of the inhibitory effect of clonidine on the amplitude of JOR, resulting in a shift to the left of the dose-response curve in comparison with that of the control group (ED₅₀ was reduced by 37%, P=0.032), without affecting either the estimated maximum effect for the agonist or the slope of the inhibitory function. This in vivo result indicates that chronic variable stress leads to an increased sensitivity of central α₂-adrenoceptors which modulate JOR, in contrast to the desensitization of these adrenoceptors found after repeated exposure to the same stressor.     

福建省产科制度改革的实施

本文介绍了福建省1991年以来加快产科制度改革的实践与经验。该省以省妇幼保健院改革产科制度为先导,以点带面地推广他们的经验,并积极发挥学术组织的作用,培训基层妇幼保健和有关医疗技术人员,使全省产科制度改革和母乳喂养工作有了新的进展。文章强调了在这项改革中加强领导,进行行政干预的重要性和必要性。     

Superficial siderosis in the central nervous system

We describe a rare entity, superficial siderosis of the central nervous system, due to multiple small episodes of subarachnoid haemorrhage from any source. Non-specific neurological findings are associated with deposition of ironcontaining pigments in the leptomeninges and superficial layers of the cortex. T2-weighted magnetic resonance imaging demonstrates characteristic low signal in the meninges.     

Transformation of 5,6-dimethoxy-2-amino-1-tetralol hydrochloride into 5,6-dimethoxy-2-tetralone

The reduction procedure of 5,6-dimethoxy-2-amino-1-tetralone with sodium bis-(2-methoxy)-aluminum hydride, followed by palladium on charcoal in the presence of HClO₄ gave a major reduction product of 5,6-dimethoxy-2-amino-tetralin, along with a small amount of a transformed 5,6-dimethoxy-2-tetralone. The isolated intermediate, 5,6-dimethoxy-2-amino-1-tetralol hydrochloride yielded exclusively 5,6-dimethoxy-2-tetralone under catalytic acidic conditions (acid treatment). The unusual rearangement was verified on the basis of IR, NMR and the result of elemental analysis. A plausible mechanism for the rearrangement is discussed.     

Corticotropin-releasing hormone microinfusion in the central amygdala diminishes a cardiac parasympathetic outflow under stress-free conditions

The central nucleus of the amygdala (CeA) is known to be involved in the regulation of autonomic, neuroendocrine and behavioural responses in stress situations. The CeA contains large numbers of corticotropin-releasing hormone (CRH) cell bodies. Neuroanatomical studies revealed that the majority of the CRH fibres from the CeA have direct connections with autonomic regulatory nuclei in the brainstem. In the present study, the effects of locally infused CRH (30 ng) into the CeA, in freely moving male Wistar rats under stress-free conditions, were examined. Heart rate, endocrine parameters and behavioural activity were repeatedly measured before, during and after local administration of CRH, pretreated with either artificial CSF or the CRH-receptor antagonist, α-helical CRH (α-CRH). CRH infusion alone caused a long-lasting increases in heart rate without affecting plasma adrenaline and noradrenaline as indicators of sympathetic activity. This CRH-induced tachycardia was effectively blocked by pretreatment with a high dose (1 μg) α-hCRH locally into the CeA, while the pretreatment with low dose (0.1 μg) of the α-hCRH caused a minor blockade of the CRH-induced tachycardia. The results suggest that CRH mechanisms in the CeA regulate the autonomic changes probably only by affecting parasympathetic but not sympathetic output systems. Because CRH is given at the level of the cell body of the CRH neurons in the CeA, we suggest that the reduction of the parasympathetic output may be explained as an autoreceptor-mediated inhibition of CRH neurons from the CeA with parasympathetic-regulating brainstem nuclei.     

Survival from acute renal failure after severe burns

We describe a patient with 50 per cent, third degree flame burns who had a history of paint thinner inhalation for over 10 years. Moreover, chlorpromazine had been administered for the treatment of insomnia caused by chronic thinner intoxication. He developed oliguric acute renal failure soon after the burn injury, although adequate resuscitation therapy was given, and survived following frequent haemodialysis. Although survival from acute renal failure after severe burns is rare, once the diagnosis of acute renal failure has been made, haemodialysis should be instituted as early as possible. Furthermore, in a severely burnt patient with episodes of chronic and acute intoxication from organic chemicals or drugs which may have caused renal damage, acute renal failure may occur, so that careful observation is advised.