3-Nitropropionic acid induces a spectrum of Huntington's disease-like neuropathology in rat striatum

Systemic administration of the mitochondrial toxin 3-nitropropionic acid (3-NP) to rats results in selective striatal lesions and serves as an experimental model of Huntington's disease (HD). However, the effects of the 3-NP treatment are unpredictable and result in lesions of variable severity. The present study was aimed at further characterizing the variability of the striatal lesions induced by systemic administration of 3-NP using osmotic pumps. Hematoxylin-eosin (HE) and Nissl stains as well as immunohistochemical labelling of astrocytes and striatal neurones were performed to analyse the neurotoxic effects of 3-NP. In general, chronic systemic administration of 3-NP resulted in obvious bilateral striatal lesions, which ranged from mild to severe, together with a subtle, but detectable behavioural lesion. Severe type lesions showed marked neuronal loss and an increased expression of glial fibrillary acidic protein (GFAP) in astrocytes surrounding the lesion area, whereas in the core of the lesion GFAP-immunoreactivity was absent. The mild type lesion was characterized by a substantial loss of striatal neurones and an increased expression of GFAP-positive astrocytes throughout the lesion. In a number of 3-NP-treated animals, neither type of lesion was observed, although these animals demonstrated behavioural changes in the paw test compared to controls. In the striatum of these tested 3-NP-treated animals, compromised rk' neurones were detected, suggestive of subtle and early 3-NP-induced neuronal injury. Similar dark neurones were also detected in mild and severe lesions and were immunocytochemically characterized as gamma-aminobutyric acid (GABA) and substance P containing spiny neurones, which belong to the neuronal population that is affected in early HD. These results indicate that systemic administration of 3-NP to rats may result in a spectrum of striatal pathology of which the morphology of the mild type lesion resembles the characteristic HD neuropathology most closely.     

Reactive oxidant species in piriform cortex extracellular fluid during seizures induced by systemic kainic acid in rats

Kainic acid (KA) administered systemically to rats produces seizures and brain damage. We measured an increase in reactive oxidant species (ROS) during KA-induced seizures in the extracellular fluid (ECF) of the piriform cortex, a brain region known to be subsequently damaged. Intracerebral microdialysis samples were collected and assayed for isoluminol-dependent chemiluminescence before and after injection of KA (16 mg/kg, ip). Hydrogen peroxide (H₂O₂) concentrations were calculated from catalase-sensitive chemiluminescence, the difference between total and catalase-resistant chemiluminescence. During generalized tonic-clonic seizures, both total and catalase-resistant chemiluminescence increased significantly in samples from brain ECF. Catalase-resistant chemiluminescence, most likely produced by ascorbic acid, increased for a full hour during sustained seizure activity. H₂O₂ concentrations showed a trend towards elevation during seizures. Increased ROS suggest that oxidative stress occurs in brain ECF during sustained seizure activity.     

Brain somatostatin: a candidate inhibitory role in seizures and epileptogenesis

Recent evidence shows that neuropeptide expression in the CNS is markedly affected by seizure activity, particularly in the limbic system. Changes in neuropeptides in specific neuronal populations depend on the type and intensity of seizures and on their chronic sequelae (i.e. neurodegeneration and spontaneous convulsions). This paper reviews the effects of seizures on somatostatin-containing neurons, somatostatin mRNA and immunoreactivity, the release of this peptide and its receptor subtypes in the CNS. Differences between kindling and status epilepticus in rats are emphasized and discussed in the light of an inhibitory role of somatostatin on hippocampal excitability. Pharmacological studies show that somatostatin affects electrophysiological properties of neurons, modulates classical neurotransmission and has anticonvulsant properties in experimental models of seizures. This peptidergic system may be an interesting target for pharmacological attempts to control pathological hyperactivity in neurons, thus providing new directions for the development of novel anticonvulsant treatments.     

山区农村散居80岁及以上老年人营养调查

对象与方法：在沂蒙山区对４个乡镇的散居高龄老人１２１人进行营养调查（男５５,女６６）,年龄最高男９６岁,女９２岁;最低男女均为８０岁。以称重法与五日询问回忆法相结合,进行四季动态的膳食调查。结果：其膳食构成以谷类（占总重量６１％～７１％）及蔬菜（１２％～１６％）为主,配有少量豆类（１．８％～４．６％）与动物性食品（６．２％～１２．０％）。按中国营养学会８０岁以上老人ＲＤＡ计算,四季能量摄入男性达到ＲＤＡ的８１％～９１％,女性达到７５％～８４％,蛋白质男性仅达到６７％～７５％,女性５５％～６７％,动物和豆类蛋白质来源不足,低于蛋白质总量的３０％～５０％。钙摄入量只有ＲＤＡ的２０％左右,锌、硒、维生素Ａ、Ｂ１、Ｂ２、Ｃ均明显不足。三大营养素所占能量比例合理,脂肪来源以植物油为主,符合老年人营养要求。营养缺乏病检查发现有维生素不足症状,如皮肤干燥鳞皮占４．１％,口角湿白厚２８．９％,舌腥红２２．３％,味蕾肥大８１．０％,膝反射消失１２．４％等。临界高血压患病率为１６．１％,高血压患病率１４．３％。生化检查：血红蛋白检测１１４人,低于１２０ｇ／Ｌ者１６．７％;血糖检测１１６人,高于正常的占６．９％,低于正常的占４７?     

Rôle du foie dans le métabolisme des nutriments en nutrition artificielle

The liver is a prominent organ in nutritional homeostasis. Due to unique metabolic properties, it plays a main role in the metabolism of the three macronutrients ‘as well as the micronutrients’ (vitamins and minerals) storage. Although it represents only 2.5% of the body mass, it consumes 20% of total resting energy expenditure and a similar percentage of the amino acid mixture absorbed via the gut during and after a meal. Due to a peculiar vascularization (portal vein, the entire gastrointestinal venous flux is directed towards the liver with all hydrosoluble nutrients, only water-unsoluble lipids being excluded from this obligatory ‘first-pass mechanism’). Since it is the location for glycogen storage, VLDL synthesis and ketogenesis, the liver is crucial in the fed-to-fasted metabolic alternation. While fat is not physiologically stored in the liver, it is a very important organ in lipid metabolism. Except immunoglobulins, all plasma proteins are synthetised by the liver together with the constitutive proteins, explaining that it is a very powerful organ for protein synthesis. Finally, due to a very active amino acid metabolism, the liver can reshape the amino acid-mixture coming from the gut in the absorptive state. Such a phenomenon has a major implication in the nutritional physiology of amino acid metabolism according to the route: enteral or parenteral. Indeed, in the latter case the remodelling by the liver does not occurs.     

血清唾液酸测定在预防性体检及肿瘤监测中的应用：唾液酸系统研究

目的　探讨血清总唾液酸（ＴＳＡ） 在预防性体检中应用的可行性及评价其监测恶性肿瘤的临床意义。方法　用化学比色法测定健康年检工人血清ＴＳＡ,分析４８２ 名ＴＳＡ 可疑阳性或阳性工人健康状况,研究２ ３０３ 名交警血清ＴＳＡ 与职业健康监护评定标准的关系、随访１０ ３７３ 名２ ～４ 年前测定血清ＴＳＡ 工人的健康状况、临床观察９４ 例恶性肿瘤患者ＴＳＡ 水平治疗前后变化。结果　（１）ＴＳＡ 在预防性体检中表明：①在４８２ 名ＴＳＡ 可疑阳性或阳性受检者中,肿瘤患者（１０ 例,２－５０ ±０－２１ ｍｍｏｌ／Ｌ） 血清ＴＳＡ 水平高于慢性疾病患者（２４０ 例,２－３９ ±０－２５） ,而后者又明显高于未患病的追踪观察者（２３２ 例,２－１４ ±０－２４） ,Ｐ＜ ０－００１ ;②按照广州市职业健康监护标准发现２ ３０３ 名广州交警血清ＴＳＡ 水平健康组明显低于异常组、追踪观察组和尚健康组,Ｐ＜ ０－０５ 或Ｐ＜ ０－００１ ;③随访发现,原ＴＳＡ 可疑阳性或阳性者新患恶性肿瘤和非恶性肿瘤疾病者明显高于ＴＳＡ 阴性者（ Ｐ＜ ０－００１） 。（２） 在肿瘤监测中发现：９４ 例恶性肿瘤患者ＴＳＡ 水平明显高于健康对照组,病人治疗后病情稳定或好转者ＴＳＡ 明显下     

叶酸拮抗乙酰水杨酸致大鼠卵黄囊毒性作用的研究

以全胚胎培养模型结合免疫组化和电镜技术等探讨了乙酰水杨酸和叶酸对大鼠卵黄囊及胚胎的影响。结果表明：培养基含乙酰水杨酸３００μｇ／ｍｌ组的卵黄囊直径和胚胎体长均显著低于阴性对照组,胚胎畸形率明显增高。组织学检查发现卵黄囊厚度变薄。间质层血岛、微血管数量明显减少,血管壁细胞不连续,血管发育不良。卵黄囊内皮层细胞顶端微绒毛少见。内皮层细胞的溶酶体、内质网及核蛋白体等结构和数量均有明显改变。而６０ｍｇ／ｋｇ叶酸灌胃鼠血清与乙酰水杨酸联合应用后,则卵黄囊的上述毒性作用明显减轻或消失,提示叶酸能明显拮抗乙酰水杨酸致大鼠卵黄囊的毒性作用。     

中国不同地区膳食脂质摄入量的分析

１９９２年中国总膳食研究在１９９０年的基础上做了适当的改进,将城市和农村的样品分别进行分析。本文报道了该项研究中膳食脂质部分的结果（包括总脂肪、胆固醇、脂肪酸）。除南方二区外,同一地区的城市和农村居民在脂肪、胆固醇的摄入量上有较大的差异。北方二区农村居民的脂肪摄入量明显不足,而北方一区城市居民脂质的摄入量较高,胆固醇摄入量已超过每人每日３００ｍ ｇ 的水平。南方居民膳食脂肪中多不饱和脂肪酸所占比例低而单不饱和脂肪酸所占比例高。基于以上分析,作者认为我国居民膳食脂质摄入情况基本合理,但由于地域差异较大,在进行膳食指导时（如关于补充ＥＰＡ,ＤＨＡ 的问题）应对不同地区的情况进行具体分析,有针对性地提出建议