胎盘组织液氨基酸的含量测定及层析鉴别

本文采用层析法进行鉴定,用氨基酸分析仪测氨基酸的含量,为胎盘组织液的质量标准提供可靠依据。本法准确率为99%。     

Effects of smoking and drinking on excretion of hippuric acid among toluene-exposed workers

Summary In order to investigate possible effects of smoking and drinking on the metabolism of toluence in occupational settings, 206 toluene-exposed men (mean age: 31.4 years) in shoemaking, painting, or surface-coating workshops together with 246 nonexposed control men (36.8 years) were studied for the time-weighted average intensities of exposure to toluene, hippuric acid concentration in shift-end urine samples, and the two social habits of smoking and drinking. The mean daily consumptions of cigarettes and ethanol were about 20 pieces and 10 g among smokers and drinkers, respectively. The geometric mean toluene concentration among the exposed subjects was about 20 ppm, with a maximum of 521 ppm. Regression analysis after classification of the subjects by smoking and drinking clearly demonstrated that the two social habits, when combined, markedly reduce the hippuric acid level in the urine of workers exposed to was a significant association between smoking and drinking habits, which hindered separate evaluation of the effects of the two habits on toluene metabolism. Comparison of the present results with the findings reported in the literature, however, suggested that the observed effects may be attributable to smoking rather than to drinking habits.     

Interaction between bovine collagen and glycolic acid peeling: A proposal of a new protocol

For the past 10 years the alfa-hydroxyacids and the bovine collagen injection have been used for peeling and the correction of multiple skin diseases. Until now, such progressive achievement has occurred in separate parallels just like the indications that have been held distinct. However, the studies carried out in order to clarify the mechanical action of the two substances have shown a common and fundamental denominator: the stimulation of synthesis of the new collagen in the patient's skin. On the basis of these results and the existence of common clinical indications of the use of glycolic acid and collagen, the authors have worked out a protocol involving a combined and contemporary application in progressive steps. They developed the rationales of such protocol and analyzed the results of its application on a number of carefully selected patients for a clinical comparison and on a sample of rats for a histological comparison. They have concluded that the contemporary use of glycolic acid and bovine collagen is a simple and safe method whose synergy action leads to more intense and long-lasting effects than the ones observed in the isolated application of the two substances. The authors have also obtained interesting and significant histological results.     

Evaluation of the safety of a non-animal stabilized hyaluronic acid (NASHA – Q-Medical, Sweden) in European countries: a retrospective study from 1997 to 2001

BACKGROUND: In Europe, several filler devices are currently on the market for use in aesthetic dermatology and some of them cause severe, permanent, adverse reactions. Since 1996 a non-animal stabilized hyaluronic acid (NASHA) from Q-Medical, Sweden, has been introduced and is becoming a leading product in aesthetic dermatology. Hyaluronic acid has no species specificity and skin testing is not recommended before treatment. OBJECTIVE: Our purpose was to evaluate the incidence of adverse reactions from 1997 to 2001 and the safety of NASHA after injections into the skin for aesthetic reasons. METHOD: Surveys were sent to physicians in European countries that agreed to participate. This is a retrospective study. A total of 12 344 syringes were sold by the Q-Medical to these physicians and we evaluated the total number of patients treated to 35% of this number (4320). We separated immediate hypersensitivity reactions from delayed reactions and analysed infectious and other types of reactions. RESULTS: From 1997 until 2001, 34 cases of hypersensitivity were reported: 16 cases of immediate hypersensitivity and 18 cases of delayed. The global risk of sensitivity is 0.8%. Since 2000, the amount of protein in the raw product has decreased and the incidence of hypersensitivity reactions is around 0.6%. As 50% of these reactions are immediate and resolved within less than 3 weeks, the risk of strong but transient, delayed reaction is around 0.3%. Four cases of abscess were reported. They were all sterile. No bacterial infection was found. Herpetic recurrence is possible after lip augmentation according to the technique of injection. No systemic reactions were reported. CONCLUSION: NASHA is a very useful and safe filler product. Skin testing does not seem to be necessary.     

Treatment of essential tremor with the barbiturate T2000 (1,3-dimethoxymethyl-5,5-diphenyl-barbituric acid).

The effect of the barbiturate T2000 (1,3-dimethoxymethyl-5,5-diphenyl-barbituric acid; DMMDPB) on essential tremor, given in twice daily doses of 400 and 300 mg, was assessed in two brief, randomized, placebo-controlled, parallel-group, double-blinded, single-center trials in 12 and 22 patients, respectively. These trials represent the first clinical use of T2000 for a specific indication. The primary endpoint was the change in the mean scores of the treated and control groups based on the Fahn-Tolosa-Marin tremor scale. In the first study of 12 patients treated with 400 mg or placebo twice daily for 14 days, the mean change from baseline at day 14 was 19.3 (P < 0.0001) in the treated group and 9.0 (P = 0.0121) in the control group. Using a two-factor mixed ANOVA model to evaluate within group and between group changes, the effect of T2000 was significantly different from that of the placebo group (P = 0.03). In the second study of 22 patients treated with 300 mg of T2000 or placebo twice daily for 20 days, statistically significant changes were seen in treated patients compared to baseline, but the ANOVA model did not demonstrate a significant treatment effect of T2000 compared to placebo. When the treated groups from each study are compared, the 800-mg daily group is significantly different from the 600-mg daily group (P = 0.02). Some treated patients in each study, but no placebo patients, experienced marked improvement. These results support further evaluation of T2000 in the treatment of essential tremor.     

大鼠脑内儿茶酚胺类递质及其代谢物的同时提取及反向高效液相测定法

目的建立一种操作简便、高效的测定脑组织中去甲肾上腺素(NA)、肾上腺素(AD)、多巴胺(DA)、3,4二羟基苯乙酸(DOPAC)及高香草酸(HVA)的方法,为有关药物作用机理的研究提供实验手段.方法以有机溶剂提取,高效液相色谱--电化学检测器(HPLC-EC)测定大鼠纹状体、皮质、下丘脑NA、AD、DA、DOPAC及HVA的含量.结果测得NA、AD、DA、DOPAC及HVA的绝对回收率依次分别为:80.3%±12.4%,86.5%±14.3%,90.3%±12.1%,89.5%±17.2%、87.6%±[13].2%.线性范围0.2～20ng,批内与批间变异系数分别小于8%及10%.结论该方法具有简便、迅速、回收率较高的特点,便于实验室应用.     

蜂毒素微球经动脉介入治疗大鼠肝癌的实验研究

目的:观察蜂毒素微球(M-MS)经动脉介入对大鼠肝癌的治疗作用.方法:采用改良的复乳-液中干燥法制备蜂毒素-聚乳酸/羟乙酸微球,建立大鼠移植性肝癌模型并随机分为四组,分别经肝动脉灌注生理盐水(NS,1.5ml/kg)、蜂毒素(Melittin,0.35mg/kg)、空白微球(B-MS,10mg/kg)和蜂毒素-聚乳酸/羟乙酸微球(10mg/kg).比较治疗后各组大鼠的肿瘤生长情况、肿瘤坏死程度和生存时间.结果:与生理盐水组比较,Melittin组、B-MS组肿瘤生长受到明显抑制(P<0.01),肿瘤坏死程度以轻中度为主,但两组动物生存时间均未能明显延长(P>0.05).M-MS组与NS组、Melittin组及B-MS组相比,肿瘤生长抑制显著(P<0.01),肿瘤坏死更广泛、更彻底,且经蜂毒素微球治疗的大鼠生存期显著延长(P<0.01).结论:蜂毒素以药物微球的剂型经肝动脉给药,抗肿瘤效果明显优于单纯的蜂毒素和空白微球.     

Glutathione conjugation of chlorobenzylidene malononitriles in vitro and the biotransformation to mercapturic acids in rats

The glutathione conjugation of 2-chloro-, 3-chloro-, 4-chloro- and 2,6-dichlorobenzylidene malononitrile (chloroBMNs) was investigated in vitro. In incubation mixtures containing rat liver cytosol (9000 g), the decrease in the initial amount of glutathione due to the various chloroBMNs ranged from 40 to 60% and occurred both enzymatically and spontaneously at physiological conditions (37°C, pH7.4). 2,6-DichloroBMN, however, depleted glutathione largely spontaneously (38±3%). The steric hindrance of the two chlorosubstituents probably plays an important role during the glutathione-S-transferase catalyzed reaction.The hydrolysis of the chloroBMNs to the corresponding chlorobenzaldehydes and malononitrile was studied in a mixture of buffer pH 7.4 and ethanol. The rate of hydrolysis of 2,6-dichloroBMN was slower than those of the related chloroBMNs. This means that 2,6-dichloroBMN will be the most stable compound in the presence of water.Only IP administration of 2-chloroBMN (CS) to adult male Wistar rats gave enhancement of urinary thioether excretion. A thioether could be isolated and was identified as the N-acetyl-S-[2-chlorobenzyl]-L-cysteine. The quantity of this benzylmercapturic acid in the urine of rats amounted to 4.4% dose (0.07 mmol/kg, n=12).After IP administration of 2-chloro- and 3-chlorobenzaldehyde to rats benzylmercapturic acid excretion in the urine was found to be 7.6 and 1.1% of the dose, respectively. Administration of the related 4-chloro- and 2,6-dichlorobenzaldehyde, however, resulted in _no urinary mercapturic acid excretion.It is very likely that in rats the initial biotransformation of chloroBMNs is mainly hydrolysis to corresponding chlorobenzaldehydes, leading in the case of 3-chloro-, 4-chloro- and 2,6-dichloroBMN to no mercapturic acid excretion in the urine.Nevertheless, 2,6-dichloroBMN will be the most reactive compound with proteins and therefore the best haptene in comparison with the related chloroBMNs.This work was financially supported by a grant from the Dutch Foundation for Medical Research FUNGO, grant no. 13-28-57     

Regulation of neuronal differentiation in neuron-enriched primary cultures from embryonic rat cerebra by platelet activating factor and the structurally related glycerol ether lipid, dodecylglycerol.

Primary cultures enriched in neurons dissociated from embryonic rat cerebra were used to demonstrate that platelet activating factor and the structurally related ether glycerolipid, dodecylglycerol, are readily taken up in small amounts by neurons and that they stimulate the differentiation of neurons. The stimulation of neuronal differentiation was observed as a precocious development of axon-like extensions which correlated with a concentration-dependent increase in neuronal-specific enzyme activities. This stimulation of morphological and neurochemical factors by either platelet activating factor or dodecylglycerol was almost completely abolished by triazolam, a known inhibitor of platelet activating factor function. Neither platelet activating factor nor dodecylglycerol at the concentrations used to achieve stimulation of neuronal differentiation compromised the plasma membrane, as indicated by the lack of leakage of cytoplasmic lactic acid dehydrogenase.     

Reversible shifts in the Ca2+-dependent release of aspartate and glutamate from hippocampal slices with changing glucose concentrations

It is known that low glucose concentrations increase the aspartate and decrease the glutamate content of brain tissue both in vivo and in vitro. To see whether these changes occur in the transmitter compartment or not, the release of aspartate and glutamate evoked by electrical-field stimulation or by high K+ was followed in slices of rat hippocampus superfused with 5 or 0.2 mM glucose. Superfusion with 0.2 mM glucose increased the evoked release of aspartate about ten times and that of glutamate about threefold. This shift in the ratio of aspartate to glutamate released was accompanied by a similar increase in the relative amount of aspartate contained in the slices. The high evoked release of aspartate and glutamate was well maintained, provided 0.5 mM glutamine was added to the medium. Changing the concentration of glucose after the first period of stimulation rapidly altered the relative amounts of aspartate and glutamate released but not the enhanced release of glutamate. The large evoked release of both aspartate and glutamate in 0.2 mM glucose was almost entirely Ca2+-dependent. The relative amounts of aspartate and glutamate released by 50 mM K+ also changed when the glucose concentration was reduced. Results suggest two effects of low glucose concentrations: an increase in the overflow of synaptically released glutamate due to a decreased uptake and an increase in the proportion of aspartate to glutamate formed and released from the transmitter pool. These observations are consistent with the interpretation that these two transmitters can be released in different proportions from the same terminals.