Physiological aspects of menopausal hot flush

Eighteen hot flushes experimenced by eight menopausal women were studied and compared with the effects of warming in six premenopausal women. The hot flushes were associated with an acute rise in skin temperature, peripheral vasodilatation, a transient increase in heart rate, fluctuations in the electrocardiographic (ECG) baseline, and a pronounced decrease in skin resistence. Although premenopausal women had greater maximum increases in skin temperature and peripheral vasodilatation, they showed a much smaller decrease in skin resistance and no changes in heart rate or ECG baseline. These findings suggest that the onset of the hot flush is associated with a sudden and transient increase in sympathetic drive. Further investigations may lead to the development of a more specific alternative to oestrogen for relieving menopausal hot flushes.     

Physiological and pharmacological aspects of adrenergic receptor classification

The questions raised are: what is the physiological or pharmacological basis for the differentiation into β₁- and β₂-, and α₁- and α₂-adrenergic receptors?; and do the neurotransmitter norepinephrine and the hormone epinephrine differ in their receptors? On the basis of a preference of β₂- and α₂-adrenergic receptors for epinephrine, the hormone, and of β₁- and α₁-receptors for norepinephrine, the neurotransmitter, it was postulated that the α₂- and β₂-receptors are predominantly epinephrinergic in nature and located extrajunctionally and presynaptically whereas the α₁- and β₁-receptors are predominantly norepinephrinergic in nature and located postsynaptically in the sympathetic terminal junction. The α₂- and β₂-character of the presynaptic receptors matches that of the corresponding extrajunctional receptors. This indicates that a circulating catecholamine, namely epinephrine, is involved in the regulation of adrenergic transmitter release.     

Physiological and neuropharmacological aspects of the central respiratory mechanisms

The present physiological and neuropharmacological views and the essentials of the experimental results on the anatomical localization, functional and neuronal organization of the central respiratory mechanisms, classically expressed as the respiratory centers, in the brain stem were reviewed and discussed. The brain stem neural mechanism for central regulation of breathing is regarded as a complex neuronal mechanism consisting of several functional subsystems subserving different functions. One of its functions is the generation of respiratory rhythm. The subsystem for respiratory rhythm-generating mechanisms is located in the medullary reticular formation outside the DRG and VRG regions, which are thought to be premotor neuron pools. Rhythmic activity originating in the medulla is dominant in terms of the spontaneity over other rhythmic activity in the pontine and spinal cord mechanisms. Evidences for heterogeneity of the functional properties of brain stem respiratory neurons have been demonstrated. Neuronal mechanisms involving respiratory neurons identified as members of the primary respiratory neuron population or neuronal networks consisting of different types of respiratory neurons located in the lateral region of the bulbar reticular formation may play important roles in the generation of respiratory rhythms. These aspects contribute to the understanding of the neurophysiological basis, providing important prerequisites for further neuropharmacological studies on neurotransmission within the neuronal network of the central respiratory mechanisms.     

Clinical-pharmacological aspects, application and effectiveness of total parenteral nutrition in surgical patients.

The term "total parenteral nutrition" (TPN) refers to the maintenance of an adequate nutritional status, normal body weight and positive nitrogen balance solely by intravenous means. It requires solutions providing calories, amino acids and other nutrients in amounts much greater than those indicated for maintenance of normal body weight. Nutrient solutions have been studied, selected and prepared in our Hospital Pharmacological Service utilizing a sterile closed system, which allows large-volume filtering, sterilizing and bottling devices. For maintenance of weight gain in adults, a basic formula is employed, which provides 1,100 Kcal/1 with pure crystalline amino acids mixed with 50% anhydrous dextrose in water in a ratio of 5.8:1 (160 Kcal:1 g nitrogen). Minerals and vitamins are added to the base solution prior to use and may be increased or decreased by simple addition or omission depending on the patient's condition. This paper is based on 192 surgical patients who received TPN and have been followed in strict cooperation between the Hospital Pharmacological Service and the Surgical Department. The patients, ranging from 23 to 79 years of age, with life threatening diseases and unable to maintain adequate nutrition by the oral route, received TPN through a central catheter inserted via subclavian puncture (146 cases) or through a surgically created internal A-V fistula (46 cases). The condition of the patients generally improved within a few days after starting TPN; and weight gain, wound healing, general improvement and a shorter period of hospitalization were observed. TPN could be efficiently combined with oncologic treatment, and a significant improvement of the patients' performance status and decrease of toxic side-effects due to chemotherapeutic agents were observed. TPN has been successfully applied also in patients with fistulas of the alimentary tract obtaining spontaneous closure and in patients with ulcerative colitis, showing its beneficial effect in allowing complete bowel rest for healing. No major complications or deaths could be attributed to TPN or to the route of administration.     

Physiological and environmental aspects of drinking stimulated by chronic exposure to amphetamine in rats

• 1.1. To examine whether the hyperdipsic response to chronic administration of d, l-amphetamine (AMPH) is associated with modification of salt appetite, rats were allowed to choose between tap water and a 1.7% NaCl solution.
• 2.2. Under AMPH rats preferred water to saline throughout the experiment.
• 3.3. By testing rats in a distinct test cage environmental influences on AMPH-mediated hyperdipsia were also evaluated.
• 4.4. In the test cage hyperdipsia was suppressed, but preference for tap water was preserved.
• 5.5. Finally, the role of α₂-adrenoceptors in the drinking response to AMPH was evaluated by studying the effects of clonidine and yohimbine on water intake.
• 6.6. We conclude that AMPH-induced preference for tap water over saline is unrelated to hyperdipsia but, being also induced by yohimbine, it may depend on noradrenergic mechanisms.

     

Insulin and insulin-like growth factor receptors in the brain: Physiological and pathological aspects

The involvement of insulin, the insulin-like growth factors (IGF1, IGF2) and their receptors in central nervous system development and function has been the focus of scientific interest for more than 30 years. The insulin-like peptides, both locally-produced proteins as well as those transported from the circulation into the brain via the blood–brain barrier, are involved in a myriad of biological activities. These actions include, among others, neuronal survival, neurogenes, angiogenesis, excitatory and inhibitory neurotransmission, regulation of food intake, and cognition. In recent years, a linkage between brain insulin/IGF1 and certain neuropathologies has been identified. Epidemiological studies have demonstrated a correlation between diabetes (mainly type 2) and Alzheimer׳s disease. In addition, an aberrant decline in IGF1 values was suggested to play a role in the development of Alzheimer׳s disease. The present review focuses on the expression and function of insulin, IGFs and their receptors in the brain in physiological and pathological conditions.     

Several aspects of mineral/protein nutrition in relation to consumption of an oil involved in the toxic syndrome

An oil involved in the 'toxic syndrome' and two similar mixtures of oils, one with and the other without added oleoanilides, were studied for their effects on the utilization of protein, calcium, magnesium, phosphorus, sodium, potassium and zinc. Forty-eight female Wistar rats initially weighing about 75 g were fed for 28 days on the same semi-synthetic diet containing: virgin olive oil, or a mixture of canbra oil (50%), refined olive-pomace oil (20%), grapeseed oil (20%) and animal fat (10%), or the same dietary mixture supplemented with either 700 ppm oleoanilides or the alleged toxic oil. Weight, food intake and nutritional balances were monitored. The food intake of the animals fed the toxic oil began to decrease at the end of the trial, producing a reduction in the amount of nutrients ingested, but no weight loss. This oil also negatively affected the digestion of protein, potassium, sodium and zinc, the mechanism of which, in the case of the first two, appears to be related to the source of the fat. It also decreased metabolic utilization while favouring protein catabolism and the elimination of phosphorus, magnesium and potassium. No substantial modifications were noted in the animals' bones.     

肠外与肠内联合营养支持是营养支持治疗的发展方向

营养不良是医院内普遍存在且没有得到充分解决的问题。能量负平衡与并发症和死亡率的关系密切。并发症的增加将导致住院时间延长和医疗总费用增加。尽管早期肠内营养支持是首选，但早期肠内营养支持治疗往往不能为处于高分解代谢状态下的患者提供足够的能量和营养。     

Self-management of nutrition

Eleven overweight subjects received a behavioral treatment program for weight loss and a nutritional self-management program during a 10-week treatment period. The nutritional self-management program was evaluated using a multiple-baseline across-groups design. The results indicated that caloric restriction without the nutritional self-management program did not result in the consumption of a well-balanced diet. Introduction of the nutritional self-management program led to improvement of nutritional consumption across six food groups. Self-control of caloric intake within certain food groups, i.e., fruit and vegetable, was better than for others. These findings are discussed in terms of the methodological difficulties involved in managing nutrition and the significance of nutritional self-management for health problems other than obesity.     

全胃切除术后早期肠内外营养的临床研究

目的探讨全胃切除术后早期肠外营养(TPN)与肠内营养(EN)的疗效。方法将因胃癌行全胃切除术的48例随机分为TPN组与EN组,每组24例。观察两组患者术后临床症状、并发症、平均住院时间、手术前后各组血清蛋白的变化及免疫功能状况指标。结果 EN组与TPN组比较术后肛门排气时间早、并发症低、住院时间短,两组比较差异有统计学意义(P<0.05);术后第3天及术后第14天,EN组的总蛋白、白蛋白、转铁蛋白水平明显高于TPN组(P<0.05);术后第7天两组CD4+T细胞、NK细胞、IgM、IgG均明显升高,两组比较差异有统计学意义(P<0.05)。结论全胃切除术后早期EN是安全、有效的营养支持途径,可迅速恢复患者的免疫状态,缩短肠道功能恢复时间和住院时间。