米团花的化学成分研究

从米团花(Leucosceptrum canum Smith)鲜叶中分到三个化学成分,经光谱测定和化学反应已确定它们的化学结构分别为异香紫苏醇(isosclaveol)Ⅰ;柳穿鱼黄素(pectolinarigenin)Ⅱ;β-谷甾醇(β-sitosterol)Ⅲ。其中化合物Ⅰ为新的天然存在的labdane类型二萜化合物。     

左旋四氢巴马汀加强电针对兔大脑皮层牙髓诱发电位的...

Cortical potentials evoked by stimulation of the contralateral tooth-pulp were recorded epidurally from the SI cortex of rabbits anesthetized with urethane and chloralose. It was found that nociceptive components of the evoked potential consisted of P1 and P2 wavelets with a relative stable peak latency of 22.5 +/- 1.2 ms and 66.1 +/- 1.9 ms respectively. Higher intensity of tooth pulp stimulation was required for appearance of P2 than P1. Diazepam, a non-analgesic sedative, reduced P1 but not P2 amplitude. On the contrary, dolantin, an analgesic, suppressed P2 but showed no significant influence on P1. The results suggest that P2, but not P1 might be related to pain. The effects of l-tetrahydropalmatine (1-THP) and electroacupuncture on P2 were observed on 12 animals. The results showed that both iv l-THP 8mg/kg and electroacupuncture brought forth a decrease in P2 amplitude by 40.3 +/- 14% and 59.3 +/- 10% respectively, while electroacupuncture combined with l-THP produce a further decrease in P2 amplitude by 92.8 +/- 7%. Furthermore, the inhibitory periods of P2 amplitude were significantly prolonged after electroacupuncture combined with l-THP. The results indicated that l-THP enhanced the suppression of P2 by electroacupuncture.     

滇紫草愈伤组织中的紫草色素

滇紫草(Onosma paniculatum Bur.et Franch)的幼嫩根茎经二步法诱导产生的愈伤组织.含有较原植物较高的紫草色素。经薄层层析鉴定,此种紫草色素由6种单体组成,其 Rf 值与原植物中的紫草色素各类衍生物非常近似。进一步采用硅胶 H 柱层析进行分离,最后得到4种单体。经结构分析证明它们是:去氧紫色素(deoxyshikonin)、β,β-二甲基丙烯酰阿卡宁(β,β-dimethylacrylalkannin)、乙酰阿卡宁(acetylakannin)和β-乙酰氧基异戊酰阿卡宁(β-acetoxyisovalerylalkannin)。     

3H]prostaglandin uptake in vivo by rabbit uterine tissues and blastocysts

Day-6 pregnant rabbits were anesthetized and subjected to a mid-ventral laparotomy. [3H] Prostaglandin F2alpha) (PGF2alpha) [3H]PGE2, [14C]Urea or [14C]Sucrose were instilled into the uterine lumen via the uterotubal junction. The amounts instilled/uterine horn were respectively 3.7 +/- 0.3, 3.5 +/- 0.3, 5.7 +/- 1.3 and 2.7 +/- 1.6 muCi in 20mul of buffer. Animals were killed at 1, 2, 9, 19 or 21 h after radioactive instillation, and the amounts of radioactivity in blastocysts, uterine tissue, peritoneal cavity washings and urine evaluated by liquid scintillation spectrometry. A gradient of radioactivity was observed from the uterotubal junction to the cervical end of the uterus. Large amounts of [3H]PG were found in the injected horn and associated blastocysts with a considerable crossover to the non-injected horn, but little in the associated blastocysts. Much of the blastocysts associated- [3H]PG remained unmetabolized. Large amounts of metabolized [3 H] were found in urine. [14C]Urea was taken up by uterine tissue in the injected horn, but there was little cross over to the non-injected horn. Urea was also found in urine. Much of the [14C]Sucrose remained in the injected horn, and little was recovered from the urine. It was found that at 9 h, but not at 19 h, after [3 H]PG instillation, the PG was localized at the site of the blastocysts in the injected but not in the contralateral horn. Significantly more [3H]PGF2alpha than [3H]PGE2 was localized in this situation. [14C]Urea was not localized at the site of the blastocysts in urea injected horns. (ABSTRACT TRUNCATED AT 250 WORDS)     

β-thalassemia mutations in the Portuguese population

Summary In this study we have carried out haplotype analysis on the -globin gene cluster and characterized the -thalassemia mutation by oligonucleotide hybridization in 14 patients with thalassemia major and 5 with sickle cell/-thalassemia originating from southern Portugal. We found that three mutations, namely the °-39, ° IVS-1 nt 1 and ⁺ IVS-1 nt 110 are prevalent accounting for 53%, 32% and 10% of the -thalassemia chromosomes respectively. In general each mutation was associated with a specific chromosomal haplotype; the ° mutation, however, was linked to three different haplotypes. These results indicate that three oligo-probes complementary to the most common mutations allow prenatal diagnosis by oligonucleotide analysis in 96% of the couples at risk of having offspring with thalassemia major in southern Portugal.     

Ultraviolet mutagenesis of the cellulase producer Aspergillus niger using protoplasts

Abstract Ultraviolet mutagenesis of Aspergillus niger strain O97 was achieved using protoplasts. Protoplasts of A. niger O97 showed the same ultraviolet killing kinetics as intact cells. After mutagenesis, several mutants were found in regenerated collonies. These mutants differ from the original strain in spore colour and cellulase-producing ability. The most active strain, designated 97V3-3 has an altered spore colour, and its carboxymethylcellose-hydrolysing, filter-paper-degradation, cotton-de-gradation and β-glucosidase activities were increased by 45.4%, 19.1%, 28.2% and 18.2%, respectively.     

Reduction of tumor growth following treatment with a glutamine antimetabolite

Assessment of arterial-venous differences across transplanted methylcholanthrene-induced sarcomas in rats revealed significant decreases in plasma concentrations of glutamine, serine and glucose. Treatment with the glutamine antimetabolite, acivicin, significantly reduced tumor weights by 65% at the conclusion of the experiment 34 days after tumor induction. These results suggest that glutamine is an essential metabolic substrate for tumor growth and that blockade of glutamine utilization can inhibit the growth of these transplantable sarcomas.     

高粱对丝黑穗病的抗性及遗传研究

1981—1985年在人工接种的条件下,对1239份高粱品种资源,进行了抗丝黑穗病性鉴定。与此同时,用17个抗性不同的品种系,按照不完全双列杂交设计,进行了高粱对丝黑穗病的抗性遗传研究。结果表明,高粱对丝黑穗病的抗性遗传方式因品种而异。有的品种系具数量性状遗传特点,有的则具有质量性状遗传特点。抗病性属数量性状遗传的品种系,其抗性主要是受加性基因控制。