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1998年  第19卷  第4期

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研究论文
An anti-microbial peptide named MSP-Ⅶ,was isolated from the skin secretion of the toad,Bombina maxima,distributed in Yunnan Province of China,by a three step protocol including Sephadex G-75 and G-50 connected with G-25 two steps of the gel filtration and one reverse-phase high-performance liquid chromatography.Fast atom bombardment mass-spectroscopy of MSP-Ⅶ gave a protonated molecular ion m/z 2648 which matched the theoretical molecular weight predicted from the composition of amino acids.It consists of twenty-six amino acid residues determined by automatic amino acid analyzer.MSP-Ⅶ is a water-soluble peptide.MSP-Ⅶ has a strong anti-microbial activity to bacteria,fungi and yeast with a little hemolysis activity.These characterizations of MSP-Ⅶ make it possible to be used as a clinical anti-microbial medicine.We tested its effect on micro-vessel osmosis ability with Evens blue dye.It was found that MSP-Ⅶ made the permeability of some tissues such as lung,liver,small intestine,to Evens blue dye increase.In particular,this peptide obviously increased permeability of lung.In addition,MSP-Ⅶ displayed an effect on the contraction of smooth muscle,which strengthened the contraction ability of rabbit aorta smooth muscle.
Taking S180-bearing mice and EAC-bearing mice as animal models,the antibacterial peptide (ABP) purified from the haemolymph of the silkworm (Bombyx mori) pupae was used to investigate the effects against the turmor in vivo.The results showed the ABP significantly inhibited turmor weight.The inhibitory rate of ABP at dose of 3792,4542,4980 U·(0.5 mL·20 g·d)[-1]×10 d,I.p.were 42.86%,39.13% and 37.89% respectively.ABP had no inhibitory effects on the number of leukocytes.Histopathological assay showed that ABP induced tumor tissue necrosis in large scales and there were lots of inflammatory cells (monocytes,neutrophils and lymphocytes) around tumor cells.It also could obviously reduce EAC peritoneal ascites fluid.
Electrocardiograms (ECG) of Eremias multiocellata were studied at 5-35 ℃ in body temperature.Electrocardiogram wave intervals (R-R,P-R,QRS,T-P,and R-T) shortened while heart rate increased with the increasing of body temperature.The average heart rate was 14.6/min at 5 ℃,whereas it was 201/min at 35 ℃.The duration of wave intervals of ECG and the heart rate were related significantly to the body temperature (P<0.001).Among the components of a cardiac cycle the cardiac rest period (TP intervals) and the atria-ventricular conduction time (PR interval) were affected mostly by body temperature.In the other hand the ventricular depolarization and repolarization (QRS and R-T intervals) were relatively less affected by the body temperature.The increasing of heart rate with body temperature was mainly caused by the shortening of ECG wave intervals,and the T-P interval (the cardiac rest period) was shortened more noticeably than other intervals.
Infant Spraque-Dawley rat pups were divided into three groups and received daily injection of saline,bestatin〔an aminopeptidase inhibitor,1 mg/kg(b.w)〕or naloxone〔2 mg/kg(b.w)〕+bestatin〔1 mg/kg(b.w)〕respectively from postnatal days 1-14.They were trained in the appetitive discrimination learning (ADL) at the age of 16 days,then in the bright discrimination learning of Y-maze (BDL) at 30 days of age.On postnatal days 45,the content of brain protein and zinc in cerebral cortex,hippocampus,cerebellum,pons,and diencephalon of the rats were examined.The results showed that the dose of bestatin inhibited significantly the learning behavior in ADL and BDL,and lowered the content of protein and zinc in hippocampus of the infant rats.Whereas,naloxone reversed partly the effect of bestatin.This suggested that the endogenous opiotide whould regulate some learning behavior through influncing synthesis of protein in hippocampus during postnatal brain development of infant rats.
An avian survey was conducted inside and outside the reserves in Xishuangbanna in December,1992,November,1993 and April through May,1993,During the survey,190 species were recorded.The species diversity was good in Passeriformes but severe in Nonpasseriformes.The diversity inside the reserve was higher than that outside ones.Longshans,the burial grounds of Dai nationality,had pretty good bird diversity,and seemed to play a special role in bird conservation.In limited time and space,habitat diversity was the main force controlling bird species diversity.Using species richness or diversity index as the only parameter might reach a wrong conclusion on evaluating conservation situation in an environment because of a majority of the common species recorded.Thus,it is suggested that the number of special bird species only recorded in one site should also be considered as a parameter in comparing bird diversity situation in different environments.
The salangid fish,Neosalanx taihuensis,has become a major export fish product in Yunnan.In order to approach steady abundant harvest of N.taihuensis with high quality in Lake Dianchi,it is urgent to set an appropriate balance point for the resources of N.taihuensis in the lake.After successive 31-month sampling investigations and applying the Von Bertalanffy growing equation,We obtained N.taihuensis growing eqs.L=6.07〔1-e[-0.198(t-0.225)]〕,W=1.78〔1-e[-0.198(t-0.225)]〕[3] for 1989 and L=7.48〔1-e[-0.173(t+0.064)]〕.W=2.76〔1-e[-0.173(t+0.064)]〕[3] for 1990.Based on the two eqs.We fitted out the correlations between body F=1999.36 C e[-0.2045] C,and finally we deduced the resource-balance point to be 1847 t,correspondingly the body weight 1.0 g per fish;density 1.175 fish/m[3],the fishing season is Aug.These results have been the goal for the Kunming Department of Fishery Management and being tested and improved in practice.
The first study of nutrition effect on musk secretion in musk deer (Moschus berezovskii) was performed after they were introduced into Shanghai,China.The tested deer were bred at Chongming Island,fed separately with silage,silage plus low-protein concentrate,silage plus high-protein concentrate,and compound feed.Then,the influence of forage nutrition on musk secretion was studied.The conclusion was that high nutrition level could promote quantity and quality of musk secretion for breeding forest musk deer.In the compound feed test period,musk secretion reached 13.475 g/ind.,increased 319.78% on previous production,and 14.97%,64.33%,and 8.58% on musk production of populations bred in Anhui Province,Shaanxi Province and Sichuan Province separately,where there were the three largest musk deer breeding farms in China.The prospect for using compound forage to increase musk secretion is magnificent according to this research.
The RLFPs of mtDNA from six Drosophila melanogaster populations in five places (Wuhan,Changsha,Guilin,Nanning and Beihai) were analysed with ten different restriction enzymes,25 restriction types were observed among 56 isofemale lines.By using Nei and Lis mathematic model and UPG method,the phylogenetic trees for both the restriction types and populations were constructed based on their genetic distances.Both of the trees showed three cluster groups,corresponding to three climalic zones:the south,middle and north subtropical zone respectively.The genetic distance within population (π[I]) except a vinegar plant population,increased with the geographic latitude.These results provid important information to study the origin and evolution of Chinese D.melanogaster.
In this paper,a statistical study of PRIBOW and transcription initiation sites in E.coli DNA protein-coding genes was presented.The range over which the two signal sequences extend was assessed,and their information content was evaluated.The results were compared with those obtained from"HUMAN"samples.Statistically significant difference were found for both signals,and were especially for corresponding to the transcription initiation site.
This paper describes three new species of the genus Phaonia R.-D.,1830 from mountainous region of Sichuan Province,China.One of them named as Phaonia redactata sp.nov.is in commemoration of Hong Kong s return to China on l July 1997 year.All the types specimens are kept in the Medical Entomology Collection Gallery,Academy of Military Medical Sciences,Beijing,China.
This paper deals with three new species of the family Cicadellidae from Hainan Province of China.The type specimens are deposited in Guizhou Agricultural College.
Evidence for that nuclear matrix is the structural and functional organizer of eukaryotic chromatins were reviewed here.(1) Chromosomal DNA is looped into domains by attachment of the chromatin fibre to the nuclear matrix.The studies of MAR (matrix-associated region) and of the nuclear matrix proteins that bind specifically to MAR are uncovering the essence of the problem.(2) Nuclear matrix is involved in DNA replication.This has been demonstrated by evidence that replication forks,replication origins and enzymes or factors involved in replication were all matrix-associated.(3) Evidence also showed that nuclear matrix was involved in RNA transcription,processing and transport.(4) Our data showed that nuclear matrix originated very early,it was argued that its origin must be the necessity of providing new structural and functional organizer for eukaryotic chromatins when eukaryotic chromatins evolved from prokaryotic chromatins in the process of origin of the eukaryotic cell.