贵州石阡县五老山21种牧草生物学性状及营养价值综合评价

在测定贵州石阡县五老山天然生长的21种牧草的生物学性状及养分含量的基础上,利用营养类型划分及系统聚类方法,对植株的生物学性状及营养价值进行综合评价,以期明晰21种天然牧草的生物学性状及营养含量特性,为石阡天然牧草资源的开发利用提供理论依据。结果表明,21种牧草中,单株净产量较高的牧草有金荞麦、葎草等11种,占样本总量的52%;抗逆性较好的牧草有知风草、画眉草等10种,占样本量的49%;营养含量较优的有金荞麦、狼尾草等13种牧草,占样本量的62%,因此,贵州石阡天然牧草有较大的开发、利用价值。以此为基础,将21种牧草划分为N、N-C、C-N、C 4种营养类型,其中N、N-C型牧草较适合对哺乳期、产蛋期等阶段的畜禽进行饲喂,而C-N、C型较适合对育肥期等阶段的畜禽进行饲喂。最后,对13个参试指标进行聚类分析,按农艺特性聚类可分为6类,其中,第Ⅲ、Ⅳ、Ⅴ、Ⅵ类牧草单株净产量较高,可作为高产牧草选育素材或推广种植,但各有特点;按生化特性聚类可分为3类,其中,第Ⅱ类牧草可作为高蛋白、抗逆牧草品种的选育素材,第Ⅲ类牧草可作为抗逆牧草品种的选育素材加以利用;按营养特性聚类可分为5类,其中,第Ⅲ、Ⅳ类牧草可作为高蛋白低脂或低纤维的优质牧草进行选育及利用。

Variations of Ion-Transport Enzyme Activities During Early Development of the Shrimps Fenneropenaeus chinensis and Marsupenaeus japonicus

The ion-transport enzyme activities were studied in the nauplii 1-2, zoea 1-3, mysis 1-3, and postlarva 1-7 of the shrimps Marsupenaeus japonicus and Fenneropenaeus chinensis. The results showed that total ATPase, Na＋-K＋-ATPase, and V-ATPase （V-type H＋-ATPase） activities increased during the early development for both the species, from zero in nauplii to stable levels after zoea stage. The enzyme activities of the latter species were significantly higher than those of the former species after zoea stage （F〉F0.05）. The contributions of Na＋-K＋-ATPase, V-ATPase and HCO3--ATPase to the total ATPase activity of the two species varied in different developmental stages and accounted for 40%-70%, 22%-46% and 2%-13% in M. japonicus from zoea to postlarva stage, whilst the shares of them were 42%-69%, 28%-44% and 2.5%-22%, respectively in Echinensis. These findings suggest the possible culture of the two species with varying water quality, especially the salinity and pH.

GCN5 Acetyltransferase Inhibits PGC1α-induced Hepatitis B Virus Biosynthesis

Hepatitis B virus （HBV） biosynthesis is primarily restricted to hepatocytes due to the governing of liver-enriched nuclear receptors （NRs） on viral RNA synthesis. The liver-enriched NR hepatocyte nuclear factor 4α （HNF4α, the key regulator of genes implicated in hepatic glucose metabolism, is also a primary determinant of HBV pregenomic RNA synthesis and HBV replication. Peroxisome proliferator-activated receptor-r coactivator la （PGCla） coactivates and further enhances the effect of HNF4α on HBV biosynthesis. Here, we showed that the acetyltransferase General Control Non-repressed Protein 5 （GCN5） acetylated PGC 1 α, leading to alteration of PGC 1 α from a transcriptionally active state into an inactive state. As a result, the coactivation activity of PGCla on HBV transcription and replication was suppressed. Apparently, an acetylation site mutant of PGC 1 α （PGC 1 αR13） still had coactivation activity as GCN5 could not suppress the coactivation activity of the mutant. Moreover, a catalytically inactive acetyltransferase mutant GCN5m, due to the loss of acetylation activity, failed to inhibit the coactivation function of PGClα in HBV biosynthesis. Our results demonstrate that GCN5, through its acetyltransferase activity, inhibits PGCla-induced enhancement of HBV transcription and replication both in vitro and in vivo.

Significance and prognostic value of lysosomal enzyme activities measured in surgically operated adenocarcinomas of the gastroesophageal junction and squamous cell carcinomas of the lower third of esophagus

AIM： To establish whether there are fundamental differences in the biochemistries of adenocarcinomas of the gastroesophageal junction （GEJ） and the squamous cell carcinomas of the lower third of the esophagus （LTE）. METHODS： Between February 1, 1997 and February 1, 2000, we obtained tissue samples at the moment of resection from 54 patients for biochemical analysis. The full set of data could be comprehensively analyzed in 47 of 54 patients＇ samples （81%）. Of these, 29 were adenocarcinomas of the GEJ Siewert type Ⅰ （n = 8）, type Ⅱ （n = 12）, type Ⅲ （n = 9）, and 18 presented as squamous cell carcinomas of the LTE. We evaluated the mean values of 11-lysosomal enzyme and 1-cytosol protease activities of the tumorous and surrounding mucosae as well as their relative activities, measured as the ratio of activity in tumor and normal tissues from the same patient. These data were further analyzed to establish the correlation with tumor localization, TNM stage （lymph-node involvement）, histological type （papillary, signet-ring cell, tubular）, state of differentiation （good, moderate, poor）, and survival （≤24 or ≥24 mo）. RESULTS： In adenocarcinomas, the activity of α-mannosidase （AMAN）, cathepsin B （CB） and dipeptidyl-peptidase Ⅰ （DPP Ⅰ） increased significantly as compared to the normal gastric mucosa. In squamous cell carcinomas of the esophagus, we also found a significant difference in the activity of cathepsin L and tripeptidyl-peptidase Ⅰ in addition to these three. There was a statistical correlation of AMAN, CB, and DPP Ⅰ activity between the level of differentiation of adenocarcinomas of the GEJ and lymph node involvement,because tumors with no lymph node metastases histologically confirmed as well-differentiated, showed a significantly lower activity. The differences in CB and DPP Ⅰ activity correlated well with the differences in survival rates, since the CB and DPP Ⅰ values of those who died within 24 mo following surgical intervention were significantly higher than of those who survived for 2 years or more. CONCLUSION： Adenocarcinomas of the GEJ form a homogenous group from a tumor-biochemical aspect, and differ from the biochemical characteristics of squamous cell carcinomas of the LTE on many points. When adenocarcinomas of the GEJs are examined at the preoperative phase, the ratio of the performed AMAN, CB, and DPP Ⅰ enzymatic activity of the tissue sample from the tumor and adjacent intact mucosa within 2 cm of the tumor may have a prognostic value even in the preoperative examination period, and may indicate that ranking of these patients into the neo-adjuvant treatment group should be considered.

Physiological responses of Chinese longsnout catfish to water temperature

We evaluated the effect of water temperature on the growth and physiology of the Chinese longsnout catfish （Leiocassis longirostris Günther）. The fish were reared at four temperatures （20, 25, 30, and 35℃） and sampled on days 7, 20, and 30. We measured plasma levels of insulin, free thyroxine （FT4）, free 3,5,3＇-triiodothyronine （FT3）, lysozyme and leukocyte phagocytic activity. The optimum water temperature for growth was 27.7℃. The plasma levels of insulin and FT4 declined significantly （P〈0.05） on day 30 at temperatures above 20℃. Lysozyme activity was significantly （P〈0.05） lower at 25℃ than at other temperatures. We conclude that final weight, insulin, FT4, and lysozyme were significantly affected by water temperature.

Analysis on Carotenoids Content and Other Quality Traits of 185 Wheat Varieties

In order to provide the reference of improving the nutritional quality traits in carotenoids and screening its resources of wheat varieties, 185 wheat varieties or lines were selected as materials to test the carotenoids content, lipoxygenase activity, whiteness, yellowness and some other quality traits of whole mill in wheat.The results showed that there were highly significant variations in lipoxygenase activity,carotenoids content, whiteness and yellowness among those sample of wheat varieties; carotenoids content was significantly and positively correlated with yellowness.Cluster analysis was performed based on carotenoids content clustered all the varieties or lines into three major groups. Additionally, carotenoids were discussed in the application of nutritional quality improvement in wheat.