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21.
After c. 30 years without sighting or capture, Anthias salmopunctatus was rediscovered at the type locality, St Peter and St Paul's Rocks, Mid-Atlantic Ridge. To date, the known distribution is restricted to depths varying from 35 to 55 m in vertical drop offs around the perimeter of the islands ( c. 400 m). This may be the smallest geographic range known for a marine fish species.  相似文献   
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Orthocoelium serpenticaecum n. sp. is described and illustrated from specimens collected from the swamp buffalo (Bubalus bubalis Linnaeus) in the Philippines. It is readily distinguished from all species of the genus by the tortuous dorso-ventral bends of the caeca and the different types of pharynx and terminal genitalium which are described as ‘serpenticaecum types’ (new types). Supported by a research grant (No. 8301 Ag) from the National Science and Technology Authority (NSTA) Assisted University of the Philippines System (UPS) Integrated Research Program.  相似文献   
24.
Cyclopid copepods collected mainly in aquatic microcosms and semiterrestrial habitats in the Juréia Ecological Reserve are studied. Hesperocyclops herbsti and Bryocyclops campaneri are described as new species and their taxonomical relationships discussed. Females of Muscocyclops operculatus (Chappuis) are redescribed and the males described for the first time. An emended diagnosis for Muscocyclops is proposed.  相似文献   
25.
An anionic (pI 4.6) isoenzyme of glutathione transferase was purified to homogeneity from human thyroid by affinity chromatography followed by isoelectric focusing. The content of enzyme was calculated to constitute about 0.2% of soluble proteins. The enzyme is formed by two identical subunits of 23,000 daltons approximately. The thyroid transferase did not catalyze the reduction of peroxides. Physical, catalytic and immunological analyses demonstrated extensive similarities between the thyroid transferase and the transferase from placenta, erythrocytes and breast. On the other hand, the thyroid transferase appears catalytically different from transferase 7-7, even if both cross-react with the antibodies raised against human placenta transferase.  相似文献   
26.
A flow cytometric study of DNA and protein contents was performed on cell suspensions obtained from 73 adult patients with non-Hodgkin lymphoma. Bivariate analysis identified a second subpopulation, not revealed by DNA determination, in 25% of the tumors. Protein heterogeneity was more frequently observed in diffuse than in nodular histology according the Rappaport classification and in high-grade than in low-grade malignancy tumors by the Kiel classification and the Working Formulation, but it was not related to ploidy or cell proliferative rate. The presence of an additional subpopulation, detected by protein analysis, defined as monoclonal by DNA analysis, could adversely affect clinical outcome in terms of response to treatment and overall survival.  相似文献   
27.
Abstract. This study was designed to define some biological aspects of cell suspensions, obtained by mechanical or enzymatic disaggregations, and to verify whether single cell suspensions are representative of original solid tumours. The study was performed on a series of 25 human solid tumours including breast carcinoma, ovarian carcinoma and malignant melanoma. A higher cell viability and a loss of aneuploid subpopulations, or a lower fraction of aneuploid cells, were observed in enzymatically-released samples than in samples obtained by the mechanical procedure. Moreover, the proliferative activity, which was generally similar for the cell suspensions obtained by the two disaggregation procedures, was always markedly lower in the cell suspensions than in solid samples from the same tumour. In conclusion, the results from this study indicate that many changes, such as selective release of cell populations from the tumour matrix, damage and destruction of aneuploid and proliferating cells can be induced to various extents by different disaggregation procedures.  相似文献   
28.
Ultrastructure and division behaviour of dinoflagellate chromosomes   总被引:1,自引:0,他引:1  
Chromosomes of Prorocentrum triestinum and P. micans have similar substructural and morphometrical values as revealed by electron microscopy of thin sections. However, differences were found between the species in mean length, volume and numerical density of chromosomes, and the volume of the chromosome complement, the nuclear volume and the chromosome number. When examined by a whole-mount procedure both Prorocentrum species have left-handed screw-like chromosomes which end in differentiated telomeres. The chromosomes divide sequentially from one telomere towards the other, presenting a Y and finally a V configuration. At the region where each chromosome divides nascent sister chromatids are connected by two bridges. Sister chromatids have similar quantitative values when compared with each other and with the still undivided chromosome, which suggests that both replication and division take place as coupled events.Supported by CAICYT, grant 2409/83  相似文献   
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Viscosity, optical activity, and differential scanning calorimetry data clearly point out that partial and/or total removal of charged substituent groups, i.e. succinate and pyruvyl residues, from succinoglycan lead to water soluble derivatives exhibiting a higher stability order → disorder conformational changes with respect to the native polysaccharide. The new succinoglycan derivatives also exhibit very little, if any, hysteresis upon ‘renaturation’ (cooling) as opposed to the case of the parent polymer. The absence of ionized groups is thus beneficial, thermodynamically and kinetically, to the attainment in dilute aqueous solution of an ordered conformation by the uncharged succinoglycan backbone, as allowed by the regular enchainment of its constituent sugar residues.  相似文献   
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