Neisseria lactamica meningitis

Neisseria lactamica was recovered from the blood and cerebrospinal fluid of a 7-month-old girl with acute purulent meningitis. The isolate was identified initially as N meningitidis. However, additional biochemical testing at the Center for Disease Control showed that the organism fermented lactose and produced beta-D-galactosidase, thereby confirming its identity as N lactamica.     

A statistical note on the association of colorectal cancer and lymphoma

The degradation and excretion of 2-14C-uric acid were examined in three adult woolly monkeys (Lagothrix lagothrichia) to determine the basis for the relatively high serum and urinary uric acid concentrations previously reported in this species. Like man and the great apes which lack uricase, but in distinction to most other mammals, these animals converted very little urate to allantoin. Uric acid turnover, as has been reported for other New World monkeys, was several times that of normal man. Renal urate excretion as well as disposition by extrarenal mechanisms may protect Lagothrix vrom hyperuricemia. The capacity to convert urate to allantoin appears to have been lost late in the evolution of New World monkeys. The woolly monkey deserves further study as a primate model for investigations of enzyme replacement strategies.     

On the metabolism of prostaglandins by rat brain homogenate

Using radio-immuno assays for prostaglandins and prostaglandin metabolites, three prostaglandin metabolizing enzymes were found in the 100,000 X g supernatant of rat brain, 15-hydroxy-prostaglandin-dehydrogenase, delta13-reductase and prostaglandin E-9-keto-reductase. Specific activity of the latter enzyme was highest in striatum and midbrain and lowest in cortex, cerebellum and spinal cord.     

Effects of zinc and vitamin A deficient diets on the hepatic mobilization and urinary excretion of vitamin A in rats

Weanling rats were fed diets deficient in zinc (ZD), vitamin A (AD), or both (ZAD) for 3 weeks. Each then received 20 mug of 11,12-3H-retinyl acetate. Plasma retinol was monitored for radioactivity for 5 hours and urine for 6 days. Rats were killed and measurements made of plasma and liver vitamin A and plasma zinc. Plasma vitamin A was depressed but growth was not affected in AD rats compared to pair-fed controls. Radioactivity appeared most rapidly in the plasma retinol fractions of the two vitamin A-depleted groups (AD and ZAD) and was excreted most rapidly in the urine of these same groups. Zinc-deficient diets (ZD and ZAD) caused depressed plasma levels of zinc and vitamin A and growth retardation greater than in pair-fed controls. However zinc deficiency had no effect on mobilization of newly-ingested vitamin A or urinary excretion of labeled metabolites. Liver stores of vitamin A were lower for ZD rats than for controls. The data indicate that zinc deficiency is not a limiting factor in hepatic vitamin A release except as it influences growth and body demand for the vitamin. The data also suggest that newly-absorbed vitamin A is mobilized and utilized in preference to that previously stored in the liver.     

Nitrous oxide "analgesia": resemblance to opiate action

Nitrous oxide produced a dose-related "analgesia" in mice (median effective dose, 55 percent). The analgesia was evaluated by means of a phenylquinone writhing test. Narcotic antagonists or chronic morphinization reduced nitrous oxide analgesia. Either nitrous oxide releases an endogenous analgesic or narcotic antagonists have analgesic antagonist properties heretofore unappreciated.     

Aldosterone secretion during high sodium cerebrospinal fluid perfusion of the brain ventricles

Conscious sheep with permanent indwelling cannulae in the lateral ventricles and the cisterna magna were Na depleted and then perfused for 9 h with an artificial CSF solution. There were 3 experimental groups: Group I (n=5) received perfusion with aritifical CSF containing NA 170 MEq./1, Group II (n=7) received perfusion with artificial CSF containing Na 145 mEq./1, Group III (n=7) received no perfusion. In Group I the blood aldosterone level fell from 26.4 +/- 7.4 to 8.6 +/- 2.3 ng/100 ml by 9 h after perfusion. There was no significant change in plasma [Na] or [K], blood angiotensin II or plasma renin concentration. Blood cortisol and corticosterone levels rose. There was also a fall in post-perfusion. Group III showed no significant change in blood aldosterone concentration. Multivariate statistical analysis showed that the fall in aldosterone levels during 170 mEq./l Na perfusion could not be accounted for by changes, either alone or together, of ACTH as evidenced by alteration in blood cortisol or corticosterone, or by change of plasma [Na], [K] or renin concentrations. This data supports the hypothesis of an additional factor which may be of CNS origin being involved in the control of aldosterone secretion.     

采前喷施保鲜剂对蓝莓贮藏品质的影响

以粉蓝蓝莓为试验材料,通过采前喷施不同保鲜剂(800mg/L纳他霉素、1 000mg/Lε-聚赖氨酸、800mg/L壳聚糖),采后于(0.5±0.5)℃冷藏,研究蓝莓果实生理品质的变化。结果表明:采前不同保鲜剂处理均能降低蓝莓果实的腐烂率,延缓蓝莓鲜果的硬度、可溶性固形物含量、可滴定酸含量及花色苷含量的降低,降低蓝莓鲜果呼吸强度及乙烯生成速率,维持较好的过氧化物酶、过氧化氢酶、脂氧合酶和抗坏血酸过氧化物酶活性,并有效降低蓝莓霉菌及酵母菌的菌落总数。采前喷施800mg/L纳他霉素对蓝莓果实的贮藏效果最好,能有效抑制蓝莓的衰老进程,维持更好的贮藏效果。     

斑马鱼在农药安全评价中的应用

主要介绍了斑马鱼的概况及其在有机氯农药、有机磷农药及杀菌剂类农药安全评价中的应用。斑马鱼作为实验模型动物,广泛应用在胚胎发育、疾病模型、药物筛选以及环境监测等方面。近年来,随着对斑马鱼了解的日趋深入,其在农药安全及环境保护中的应用也越来越被人们重视。