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51.
CONCENTRATIONS OF ENERGY METABOLITES AND CYCLIC NUCLEOTIDES DURING AND AFTER BILATERAL ISCHEMIA IN THE GERBIL CEREBRAL CORTEX 总被引:2,自引:0,他引:2
Abstract— The concentrations of metabolites which reflect energy production or use ( P -creatine, ATP. ADP. 5'AMP, glucose, glycogen and lactate) and cyclic nucleotides (cyclic AMP and cyclic GMP) were measured in gerbil cortex during ischemia and recirculation. Bilateral ischemia of the gerbil brain was chosen as a model to ensure the assessment of short periods of ischemia without ambiguity. The metabolites and cyclic nucleotides were measured after, 1, 5. 20. 30 and 60 min of ischemia; and 1, 5, 30, 60 and 360 min after circulation was reestablished. The greatest changes in metabolites and cyclic nucleotides due to ischemia occurred during the 1st min; ischemia of longer duration had little further effect. However, the restoration of the metabolic profile was altered by the duration of the ischemic period. In general, the longer the period of ischemia, the slower the replenishment of high-energy phosphate compounds and energy sources. Cyclic AMP increased 5- to 13-fold during ischemia; cyclic GMP decreased to as little as one-fifth control values 60min after occlusion. During recirculation, cyclic AMP increased as much as 100-fold, while cyclic GMP increased up to 6-fold. The temporal derangements in cyclic nucleotide concentrations coincide with the loss and restoration of cortical activity; a possible mechanism has been suggested. 相似文献
52.
Summary A patient with acute lymphoblastic leukemia (ALL) whose cells had L3 (Burkitt-type) morphology was found to have a variant translocation t(2;8)(p13;q24), that has been reported only in Burkitt lymphomas. This observation provides additional evidence for a close association of particular karyotypic abnormalities with both Burkitt-type ALL and Burkitt lymphoma. 相似文献
53.
Summary Reticulum cell sarcoma (RCS) cells of SJL/J (H-2s) mice have been shown to express antigens that are cross-reactive with allogeneic cells of the H-2d and H-2b haplotypes by cell-mediated cytotoxicity, antibody-mediated cytotoxicity, immunofluorescence, and quantitative absorption assays. These alien antigens have been detected on both spontaneous and in vivo- and in vitro-passaged RCS cells to varying degrees.The in vitro cell lines were able to stimulate a syngeneic cytotoxic T cell response detected in a 4-h 51Cr release assay. The cytotoxic cells reacted with in vitro RCS tumor targets but not with in vivo or spontaneous RCS tumors. Furthermore, the cytotoxic cells lysed H-2d and to a lesser extent H-2b target cells, but not H-2k, H-2p, or H-2r cells. The cross-reactivity was also observed with SJL/J anti-BALB/c cytotoxic cells, which can lyse in vitro RCS targets effectively. The in vivo tumors were not stimulatory in cytotoxic responses and did not serve as targets.H-2d specificities were also detected in cultured RCS tumor cells by cytotoxic antibody. Both allogeneic SJL/J anti-BALB/c, C57B1/6 anti-BALB/c sera reacted with RCS tumor cells and not normal SJL/J cells. Furthermore, monospecific Dd sera were also cytotoxic against RCS lines. The cytotoxic activity could be absorbed by BALB/c cells and RCS cells but not with normal SJL/J cells. The H-2d specificities were also detected on the in vivo lines by indirect immunofluorescence. The majority (60%) of spontaneously arising tumors expressed either H-2d or H-2b allospecificities in the immunofluorescence assays. Although these antigens may not be inappropriate for the SJL/J strain, their differential expression on tumor cells may be significant in the etiology of the tumor. 相似文献
54.
The Geonemertes problem (Nemertea) 总被引:2,自引:0,他引:2
A new genus of monostiliferous hoplonemerteans, Pantinonemertes gen. nov., provides evidence for the separate evolution of terrestrial nemerteans. The genus is established for two new species found in Australia, P. enalios sp. nov., an intertidal form, and P. winsori sp. nov., which lives in fallen timber in the supralittoral brackish water regions of mangrove swamps. One only of the known species of land nemerteans, Geonemertes agricola from Bermuda, closely resembles these two species morphologically and is transferred to the new genus as Pantinonemertes agricola .
A re-examination of all the known species of Geonemertes has shown that two major groups can be distinguished on the basis of morphological characters. In one group the rhynchocoel musculature is in two distinct layers, a frontal organ is present, the mid-dorsal blood vessel has a single vascular plug, and the flame cells are binucleate and reinforced with cuticular support bars. It comprises the genus Pantinonemertes gen, nov, and the Pelaensis or Indopacific group of terrestrial nemerteans, for which the generic name Geonemertes is retained. In the second major group the rhynchocoel musculature is composed of interwoven longitudinal and circular fibres, there is no frontal organ, the mid-dorsal blood vessel bears two vascular plugs, and the flame cells are mononucleate and lack support bars. Five genera, three of which are new, are distinguished in this group. Australian species are united in the genus Argonemertes gen. nov., and New Zealand forms comprise the genus Antiponemertes gen. nov., while Acteonemertes bathamae from New Zealand and the Auckland and Ocean Islands remains in a separate genus. Geonemertes nightingaleensis is transferred to a new genus, Katechonemertes gen. nov., and for Geonemertes chalicophora a previously used generic name, Leptonemertes , is adopted.
A key to the terrestrial, brackish-water and marine nemertean species described in the present paper is provided. 相似文献
A re-examination of all the known species of Geonemertes has shown that two major groups can be distinguished on the basis of morphological characters. In one group the rhynchocoel musculature is in two distinct layers, a frontal organ is present, the mid-dorsal blood vessel has a single vascular plug, and the flame cells are binucleate and reinforced with cuticular support bars. It comprises the genus Pantinonemertes gen, nov, and the Pelaensis or Indopacific group of terrestrial nemerteans, for which the generic name Geonemertes is retained. In the second major group the rhynchocoel musculature is composed of interwoven longitudinal and circular fibres, there is no frontal organ, the mid-dorsal blood vessel bears two vascular plugs, and the flame cells are mononucleate and lack support bars. Five genera, three of which are new, are distinguished in this group. Australian species are united in the genus Argonemertes gen. nov., and New Zealand forms comprise the genus Antiponemertes gen. nov., while Acteonemertes bathamae from New Zealand and the Auckland and Ocean Islands remains in a separate genus. Geonemertes nightingaleensis is transferred to a new genus, Katechonemertes gen. nov., and for Geonemertes chalicophora a previously used generic name, Leptonemertes , is adopted.
A key to the terrestrial, brackish-water and marine nemertean species described in the present paper is provided. 相似文献
55.
The GABAergic system was investigated in C-6 astrocytoma cells and C-1300 neuroblastoma cells in culture and compared to that in mouse brain. The activities of glutamate decarboxylase, GABA-transaminase, succinic semialdehyde dehydrogenase and glutamate dehydrogenase were measured. In the cultured cells, only glutamate dehydrogenase activity was equal or greater than that of mouse cerebral cortex. Glutamate decarboxylase in both cell lines was 2%, while GABA-transaminase and succinic semialdehyde dehydrogenase activities were less than 20% of those found in brain. In spite of the disparate enzyme activities, GABA, glutamate, and -ketoglutarate concentrations were similar in the cell lines and cerebral cortex. The anticonvulsant drugs sodium valproate and aminooxyacetic acid increased cortical GABA concentrations but either had no effect or decreased GABA in the cells in a complete medium. The convulsant isoniazid decreased GABA in mouse brain but had no effect in either cell line. In the absence of pyridoxal in the medium, some drug effects could be induced in the cultured cells. It is concluded that the differing responses of the GABAergic system in the mouse brain and cell lines may be attributed in part to the fact that the cells do not represent an integrated system and are of tumor origin. 相似文献
56.
Francis L. Marcrina R.Paul Evans Janet Ash Tobian Donna L. Hartley Don B. Clewell Kevin R. Jones 《Gene》1983,25(1):145-150
A novel plasmid vector that is able to replicate both in Escherichia coli and in Streptococcus sanguis is described. This 9.2-kb plasmid, designated pVA856, carries Cmr, Tcr and Emr determinants that are expressed in E. coli. Only the Emr determinant is expressed in S. sanguis. Both the Cmr and the Tcr of pVA856 may be insertionally inactivated. This plasmid affords several different cleavage-ligation strategies for cloning in E. coli followed by subsequent introduction of chimeras in to S. sanguis. In addition, we have modified a previously described E. coli-S. sanguis shuttle plasmid [pVA838; Macrina et al., Gene 19 (1982) 345–353], so that it is unable to replicate in S. sanguis. The utility of such a plasmid for cloning and selecting sequences enabling autonomous replication in S. sanguis is demonstrated. 相似文献
57.
The relative influence of age and weight on the reproductive behaviour of male grey seals Halichoerus grypus 总被引:1,自引:0,他引:1
The breeding behaviour of male grey seals Halichoerus grypus of known age and weight was studied on Sable Island, Nova Scotia. Branded males ranged in age from 8 to 16 years and although there was a positive relationship between age and weight, there was a large overlap between age classes. In general, there was an increase in length of tenure and rates of copulation with increasing male age but this was less marked among males between the ages of 13 and 16 years. Compared to older ones, males of 8 and 12 years were observed at more sites, travelled more extensively around the breeding colony, were transient more frequently and were unable to lie as close to females. There was no correlation between male body weight and either length of tenure or rates of copulation when males of age 8 (the smallest males) were excluded from the analysis. Most agonistic behaviour was made by larger, older males towards smaller, younger ones and appeared to be responsible for the short length of tenure and low reproductive rates of young bulls. 相似文献
58.
Macrocystis pyrifera gametophytes were exposed in batch culture to varying mass concentrations of buried, sewage-contaminated, historically discharged sediment that had been sampled from two sites off Palos Verdes Peninsula, California. Significant gametophytic vegetative growth inhibition was detected in six days, using digital image analysis at sediment loadings ranging from 0.15 to 14.5 g in 500 mL nutrient-enriched seawater. Inhibition declined at low sediment loadings and increased at high loadings as cultures aged. Sediments corresponding to the historic emissions peak taken 2 km from the Joint Water Pollution Control Plant outfall inhibited vegetative growth more than did sediments sampled 13 km distant. Analysis showed elevated aqueous Cd(II), Cr(II) and p,p-DDE concentrations in high sediment-loading culture medium. Inhibition by Zn(II) alone was observed at similar concentrations in other experiments, but synergism or antagonism by other toxicants remains possible. 相似文献
59.
60.
Summary The location of materials containing terminal fucose residues on the surface of axenic and field grown roots of corn has been determined.Binding patterns of FITC-labelled,Lotus purpureus Moench lectin indicate the presence of the fucose residues in the cell walls and mucilage of the peripheral region of the root cap. During development, fucose residues also appear in the outer periclinal walls and overlying mucilage of columnar epidermal cells. Surface material rich in these residues persists between the mature root hairs but is not found on their surface. Fucose-rich mucilage is present on the exposed surface of aerial roots and at the point where they enter the soil. No lectin binding residues are indicated elsewhere in the roots. 相似文献