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1984年  第5卷  第2期

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研究论文
Morphological changes of Ancylostoma duodenale and Necator americanus at various development stages in animal hosts (young dogs and golden hamsters) were studied.Both species during their skin and muscle stages are similar to the 3rd stage larvae before entering hosts.In host s lung,N.americanus undergoes some obvious changes but not A.duodenale.In the 4th stage larvae,the length of mouth cavity of A.duodenale is almost equivalent to its width,but that of N.americanus is shorter.At that stage,the vulva of N.americanus is situated at the posterior part of its body;while in the 5th stage larvae and adult,it is at the anterior part.There is a pair of openings on the sub-ventral part of mouth cavity in both species,but more prominent in A.duodenale.Another pair of openings occur in the deep sub-dorsal part of the mouth cavity,more prominent in N.americanus.At the 4th stage,besides tue vulva,worm sex can also be distinguished by its tail.A pair of spiral phasmids are found in the anterior ventral part of bursa.Two pairs of papillae on the dorsal surface of either side of closcal openings are found in both species,but obvious differences in morphology between two species.In addition,it is observed for the first time that there is a pair of small papillae in the position of lateral ray of bursa in male and a tail spicule in female of N.americanus.
The present paper reports two new species of trematodes parasites belonging to Paragono Pearse,1930 (Troglotrematidae,Paragoninae).One was collected from a curlew,Numenius arquata orientalis Brehm and the other,from a herring gull,Larus argentatus vegae Palmen.Both were found in Tianjin.All measurements are in mm.The type specimens are deposited in Nankai University and the new species are characterized as follows.
The changes of DNA and RNA have been determined in the whole body and in several organs of the Eri-silkworm Attacus cynthia ricini.Both DNA and RNA increased rapidly from forth-fifth instar ecdysis to 4 or 5 days of the fifth instar,especially in integument and silkgland.The incorporation of radioactive precursors (3H-thymidine and 3H-uridine) into the nucleic acids of whole body and different organs has been described.
The degrees of methylation of MS[3] gene regions detectable with MS[3] probe were found to be nearly the same in F9 genome and TDM[1] genome.Nuclear transcripts of MS[3] genes were detected not only in F[9] cells but also in TDM[1] cells.These results suggest that the failure of detection of MS[3] RNA in the cytoplasm of differentiated cells may be mainly due to the defect of splicing the nuclear transcripts of MS[3] genes or inability of transfer of the mature MS[3] RNA from nucleus to cytoplasm.
The present paper describes three new species belonging to the family Catantopidae,which were collectad from west Yunnan.The type specimens are all deposited in the collections of Shanghai Institute of Entomology,Academia Sinica.
In this paper,we make anatomical and histological observation on the female reproductive organs of two giant pandas,one in rutting period,the other the pre-oeatrus period.The analyses show the following results:1)On the surface of a four year old female ovary,there are clegts,which are just the same as described by Davis,Dwight D.(1964).But we observe the surface of a ten to fifteen year old female ovay is smooth.2)The primary ovocytes are scattering or in groups on the cortical layer and the secondary follicles,the approximately matured growing follicles and the matured follicles are distributed in the cortical substance and the outer medullary substance layer,or overlapping in groups on the surface of the ovary.3)During the rut period,the left ovary appears bigger than the right one,and its follicules are protruding and overlapping in groups,while the surface of the dexter ovary is smooth,and follicules do not protrude out.4)By analysing the giant panda farrowing records,every female ovulates out 1-2 ova in its rutting period,very raritily 3.A great quantity of approximately matured and matured follicules retrograde into atretic follicules.It is of theoretical significance in the field of mammalian evolution.5)The oviduct is very short and its contortion is small Adult cornus uteri is divided into thick and thin section,its septum developed.The cervix is stratified epithelium,its tunica intima has no gland.
A virulent strain of Escherichia coli had been isolated and found to be the pathogen of piglet dysentery by Mr.Li Xue-liang (Yunnan Institute of Animal Husbandary and Veterinary Medicine).When 6×107 living bacteria of the virulent strain were injected subcutaneously into each mouse,all the injected mice would be killed.Ribosomal preparations were isolated from disrupted cells by a modification of the ammonium sulfate precipitation method described by C.G.Kurland (1966),omitting the ultracentrifugation step.The ribosomal preparation was proved to be highly immunogenic for mice and immunization with the preparation elicited significant protective immunity.The effect was obvious when mice immunized subcutaneously with ribosomal preparation without adjuvant were challenged subcutaneously with 2-2.4×108 living bacteria two weeks after immunization.
A highly dependable method for the detection of in vivo induction of chromosomal aberration has been developed in liver,bone-marrow and spermatogonial cells in mice subjected to partial hepatectomy.The inductivities of chromosomal aberrations by benzene and cyclophosphamide are different.When the partially hepatectomized mice were injected intraparitoneally with freshly prepared cyclophosphamide solution (15 μg/g body wt.),the inductivity to the three target cells is bone-marrow cells>regenerating liver cells>spermatogonial cells,whereas the inductivity of benzene (0.01 ml/mouse,2 subcutaneous injections) is regenerating liver cells>bone-marrow cells>spermatogonial cells.To develop this procedure will facilitate the detection of drug-induced clastogenic activity,particularly those requiring tissue-specific metabolic activated procarcinogens/promutagens and in vivo comparison of clastogenic sensitivity among the three types of tissues.
In November 1981,we collected a fresh-water dinoflagellate-Glenodinium gymnodinium penard from a pool in the suburbs of Kunming.We have succeeded in the culture of this organism in the laboratory.The medium used is a modified artificial medium for growing Volvox globartor,devised by Provasoli and Pintner (1959).The process of culture is divided into three steps:(1) preliminary culture;(2) pure culture and (3) expand culture.The work is carried out under 8-12 hours illumination each day (the intensity of illumination is at 800-1200 Lux) and at temperature 9-26℃ in the common laboratory.So far,the culture of these cells has been carried to more than 300th progeny.After the culture,we also observed the reproduction form,the growth curve and nuclei of this dinoflagellate,the result showed this organism is a rare dinoflagellate both with a mesocaryotic and an eucaryotic nucleus.
As both cortical structures and nuclear apparatus can be displayed simultaneously,protargol technique is used in the study of morphology and the evolutionary process in the development of nuclear apparatus and ciliatures of Tachysoma pellionella during its asexual reproducing cycle.
The specimens of Narcine maculata wer obtained from South Sea of China.