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21.
We have previously reported that the antitumor effect of OK-432, a streptococcal preparation, is markedly augmented when injected intratumorally together with fibrinogen (OK-432/fbg) [1]. In order to elucidate the effects of this immunotherapy on regional lymph nodes (RLN), we carried out both morphological and functional analyses of the RLN from colonic cancer patients treated with OK-432/ fbg. Computer-aided morphometry revealed that the maximal cross-sectional areas and the broadest diameters of the RLN were significantly greater (p<0.01) in patients who had undergone local immunotherapy than in patients who had not. The component structures of RLN, such as sinus, follicle and paracortex, were all enlarged in the OK-432/fbg-treated patients, and necrosis of metastatic tumors was observed. RLN lymphocytes recovered from OK-432/fbg treated patients showed elevated reactivity to phytohemagglutinin (PHA) and the stimulation index was clearly higher than that of control patients. Flow cytometric analysis revealed a predominance of T-cells, especially CD4 subsets, and higher positivity for both CD25 and HLA-DR. Furthermore, RLN lymphocytes killed more effectively K562 and Daudi cells in the patients who had had immunotherapy. These results suggest that the effect of local immunotherapy with OK-432/fbg is not restricted to the site of injection but extends to the lymph nodes, and contributes to tumor regression through the augmentation of cellular immunity.Abbreviations RLN regional lymph node(s) - OK-432/fbg OK-432/fibrinogen solution - PHA phytohemagglutinin - NK natural killer - LAK lymphocyte activated killer  相似文献   
22.
The glucose transport activity solubilized from the basal and plus insulin forms of the Golgi-rich fraction of adipocytes was partially characterized, and the results were compared with those of the activity obtained from the plus insulin form of the plasma membrane-rich fraction. The transport activity was determined in a cell-free, reconstituted, system. Prior to reconstitution, the activities in the three preparations were all (a) stable at 0°C for at least 4 h, but not at 37°C or above; (b) most stable at pH 7–9, and (c) less stable in Tes than in Tris buffer. After reconstitution, the three activities were all (d) stable at 0°C, (e) most active at pH 5.5, (f) mildly stimulated by divalent cations, (g) unaffected by insulin or 1 mM of several SH-blocking agents, (h) inhibited by heavy metal ions, 10–100 mM of monovalent salts, organic solvents, several sugar isomers, and specific sugar-transport inhibitors. The rates of d-glucose uptake by the three liposome preparations were all inhibited more strongly by 2-deoxy-d-glucose or 3-O-methyl-d-glucose than by d-glucose. These data indicate that the general properties of the glucose transport activity in the Golgi-rich fraction are similar to those of the activity in the plasma membrane-rich fraction.  相似文献   
23.
The relationship between adenine-nucleotide levels and metabolism-dependent membrane potential was studied in cells of Nitellopsis obtusa. Effects of ADP and AMP in the presence of ATP on electrogenic pump activity were measured in the dark, using the continuous perfusion method. Both ADP and AMP acte as competitive inhibitors for ATP, the Ki value for either compound being about 0.4 mM. The role of ADP and AMP as regulating factors for the electrogenic pump was investigated under various metabolic conditions. Application of N2 gas in the dark caused a significant membrane depolarization amounting to 90 mV, but cytoplasmic streaming and membrane excitability were not affected. Under anoxia, the ATP level decreased from 1.6 to 0.5 mM; ADP increased but only slightly, and AMP increased greatly. However, the time course of changes in the adenine nucleotides was not concurrent with that of the membrane-potential changes, thus, the adenine-nucleotide level changes cannot fully account for the N2-elicited depolarization. Under light, although the membrane hyperpolarized, no significant changes in the adenine-nucleotide levels were observed. Therefore, the light-induced membrane hyperpolarization cannot be explained solely by changes in adenine-nucleotide levels.Abbreviations APW artificial pond water - Em membrane potential - Rm membrane resistance  相似文献   
24.
Summary Stimulus intensity-response relations (V-log I curves) were electrophysiologically (ERG) determined for the compound eyes of 46 lepidopteran species belonging to five different groups: butterflies (22 species), hesperids (3 species), diurnal sphingids (2 species), diurnal moths (3 species) and nocturnal moths (16 species). The V-log I curves were fitted to the Naka and Rushton equation, in whichn represents the slope of the linear part of each curve. The slopes so determined range fromn=0.35 (the shallowest slope) in nocturnal moths with the greatest dynamic range ton=0.54 (the steepest slope) in diurnal moths andn=0.53 in butterflies both of which have narrow dynamic range. Hesperids (n=0.41) and diurnal sphingids (n=0.38) have intermediate values between butterflies and nocturnal moths.The ratio of rhabdom to retinula volume is significantly higher in nocturnal moths (70–75%), however, those of butterflies and of diurnal moths are very small (2–5%), and hesperids and diurnal sphingids show intermediate ratio (ca. 25%).The slopes of V-log I curves are inversely proportional to the ratio of rhabdom to retinula volume in the various eye types. In all groups except diurnal moths, the light intensities which produce maximal and saturated responses are nearly the same, therefore the nocturnal moths which have the lowest threshold to light increase their sensitivity to dim light mainly by decreasing the slopes of V-log I curves.  相似文献   
25.
Summary The enzymatic characteristics and the mode of hormone-dependent stimulation of cAMP phosphodiesterase are reviewed. The hormone-sensitive phosphodiesterase is a low Km enzyme, which has been found in liver and fat cells. The fat cell enzyme is mostly associated with the endoplasmic reticulum. The liver cell enzyme is also associated with certain subcellular structures.The hormone-sensitive phosphodiesterase appears to have catalytic and regulatory domains and is thought to be attached to subcellular structures at the regulatory portion of the enzyme. The catalytic domain of the fat cell enzyme can be obtained in a soluble form from the microsomal preparation by mild proteolysis or by dithiothreitol treatment at 0–4 °C. The catalytic domain of the liver enzyme can be solubilized by either hypotonic treatment or mild trypsin digestion. The catalytic domains solubilized from the basal and hormonally activated forms of the enzyme are apparently identical.The membrane-bound basal enzyme from adipocytes is activated in a concentrated salt solution without being solubilized. On the other hand, the plus-insulin activity is deactivated in a low salt solution or by a short dithiothreitol treatment at 37°, apparently without suffering any changes in the catalytic domain. In contrast, p-chloromercuriphenyl sulfonate seems to inactivate the enzyme by interacting with SH-groups in the catalytic domain. Although the liver enzyme is not similarly affected by salt concentrations, its catalytic activity is blocked by p-chloromercuribenzoate.The adipocyte enzyme can be solubilized with a mixture of Lubrol WX and Zwittergent 3–14. The apparent Stokes radius of the basal enzyme is approximately 87 A, while that of the hormone-stimulated enzyme is approximately 94 A.Apparently, the same species of phosphodiesterase is activated by both insulin and epinephrine in fat cells and by insulin and glucagon in liver, possibly being mediated by reactions involving phosphorylation. However, it is yet to be ascertained how phosphorylation is involved and how the apparent Stokes radius of the adipocyte enzyme is increased as a result of stimulation.  相似文献   
26.
Pretreatment of Chang liver cells with N-ethylmaleimide (0.5 or 1 mM) stimulated Na+-independent uptake of leucine at low concentrations (?1 mM). The stimulatory effect of N-ethylmaleimide on the uptake of leucine measured in Na+-replete medium was completely blocked by the addition of b-2-aminobicyclo[2,2,1]heptane-2-carboxylate (5 mM), which shows that the L system participates in the stimulation. The Na+-dependent uptake of glycine was depressed by N-ethylmaleimide pretreatment. The stimulation of the Na+-independent component of leucine uptake continued for at least 30 min after N-ethylmaleimide treatment, while the inhibition of glycine uptake was progressive with time and the Na+-dependent uptake of leucine became depressed later, after the treatment. It has been demonstrated that treatment of cells with N-ethylmaleimide is capable of increasing the Na+-independent influx of leucine and at the same time slightly decreasing the efflux of it. These results suggest that N-ethylmaleimide attacks the Na+-independent system of amino acid transport at the reactive SH groups(s) of relevant protein(s) in favor of specific activation of that system in this cell.  相似文献   
27.
Three Athalia sawflies, A. japonica, A. rosae and A. infumata, feeding on cruciferous plants, coexist in Japan. However, it is not known what ecological strategies they use and what environmental factors are crucial to such strategies. I attempted to explain these questions by examining the relationship between the spatio-temporal distribution patterns of three Athalia sawflies and their habitats in three districts (Lowland, Intermediate and Mountain). The three sawflies have different spatio-temporal distribution patterns, though they usually used common cruciferous plants. A. japonica was abundant in spring and autumn but disappeared during summer in all the districts. In the Lowland, populations of A. rosae and A. infumata, like that of A. japonica, crashed in summer. However A. rosae occurred mainly in summer in the Intermediate and Mountain. Although A. infumata occurred in the same seasons as A. rosae in all districts, population levels of A. infumata were always lower than those of A. rosae. The crucial factors controlling their population patterns were the availability of host plants and temperature. Population crashes of A. rosae and A. infumata were due to food depletion, and those of A. japonica were due to heat stress. On the other hand, their population patterns may be interpreted as phenological synchronization with their original host plants, though they all existed on common cruciferous plants. The three sawflies may have evolved different strategies to escape from unfavorable habitat conditions. Such strategies are speculated to be summer diapause in A. japonica, long distance migration in A. rosae, and local dispersal in A. infumata.  相似文献   
28.
We recently reported that by postnatal day 40 the activity of sn-glycerol-3-phosphate dehydrogenase (GPDH) was significantly depressed in the cerebellum of genetic-hypothyroid mutant mice. This mutant mouse-GPDH combination was used in the present study to define the critical time period during which thyroid hormone (T4) and growth hormone (GH) are essential for maturation of Bergmann glial cells. Our findings are that (a) induction of GPDH activity in the Bergmann glial cell is dependent on T4, (b) T4 is most effective when administered during the second 20 days of postnatal life, (c) the effect of GH on GPDH activity is complementary to or synergistic with that of T4, and (d) Bergmann glial cells and radial glial fibers of the mutant mice contain immunoreactive GPDH following various hormonal treatments. These results suggest that T4 is indispensable for the maturation of Bergmann glial cells.  相似文献   
29.
Electron transfer between horse heart and Candida krusei cytochromes c in the free and phosvitin-bound states was examined by difference spectrum and stopped-flow methods. The difference spectra in the wavelength range of 540–560 nm demonstrated that electrons are exchangeable between the cytochromes c of the two species. The equilibrium constants of the electron transfer reaction for the free and phosvitin-bound forms, estimated from these difference spectra, were close to unity at 20°C in 20 mM Tris-HCl buffer (pH 7.4). The electron transfer rate for free cytochrome c was (2–3) · 104 M?1 · s?1 under the same conditions. The transfer rate for the bound form increased with increase in the binding ratio at ratios below half the maximum, and was almost constant at higher ratios up to the maximum. The maximum electron exchange rate was about 2 · 106 M?1 · s?1, which is 60–70 times that for the free form at a given concentration of cytochrome c. The activation energy of the reaction for the bound cytochrome c was equal to that for the free form, being about 10 kcal/mol. The dependence of the exchange rate on temperature, cytochrome c concentration and solvent viscosity suggests that enhancement of the electron transfer rate between cytochromes c on binding to phosvitin is due to increase in the collision frequency between cytochromes c concentrated on the phosvitin molecule.  相似文献   
30.
Abstract: Conventional histological examination of the pituitary does not distinguish Snell dwarf mutants (dw/dw) from their normal littermates (+/?) in the neonatal stage. However, immunohistochemical examination of pituitaries of litters born to heterozygous Snell parents revealed that in approximately 25% of the glands examined, the number of positive cells was very low in the neonatal stage. We attempted to delineate the events resulting in the poor myelination in the brain of the Snell dwarf mouse, and to devise an immunohistochemical method for identifying the mutant neonate. Differences in the brain weights of the dw/dw and +/? mice first became apparent on the 10th day of age, and from this time on no further increase in the weight of the dwarf mouse brain was recorded. Increase in CNPase activity was found to be suppressed in the cerebrum and brain stem throughout the developmental stage, but not in the other parts of the brain. The yield of isolated myelin decreased by 58% in the mutant mouse, but CNPase activity was equivalent to that of control myelin. Differences in DNA content per cerebrum from the dw/dw and +/? mice first became apparent on the 10th day of age. Henceforth, the dw/dw mice showed no further increase, although the +/? mice continued to increase. [3H]Thymidine incorporation into the DNA fraction in vivo on the 7th day of age, when glial cell proliferation in the cerebrum is most active, was suppressed to about 50% of the control level in all parts of the dwarf brain. These findings indicate that the poor myelination found in the mutant cerebrum is a hypomyelination due to reduced oligodendroglial proliferation caused by lack of circulating growth hormone.  相似文献   
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