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1.
对杂交鳢(斑鳢♀×乌鳢♂)(Channa maculata ♀×C.argus ♂)及其自交后代的细胞核型进行了初步分析.结果表明,杂交鳢染色体数目为2n=45,核型公式为3m+4sm+6st+32t,染色体臂数(NF)为52;杂交鳢自繁后代群体存在两种染色体核型,一是染色体数目为45,核型公式为3m+4sm+6st+...  相似文献   

2.
Lymphocytes CD8+ have been assayed prospectively in 245 individuals infected with HIV. Percentage and number of CD8+ have been nearly two-fold higher in asymptomatic patients or patients with lymphadenopathy than those in the control group. The number of CD8+ lymphocytes has been rapidly decreasing parallel to the progression of HIV (ARC and AIDS), while their percentage has increased--however insignificantly. There has been a positive correlation between the number of CD4+ and CD8+ cells and all clinical stages of HIV infection.  相似文献   

3.
The binding of Eu3+ with Ca2+-stimulated, Mg2+-dependent adenosine triphosphatase ([Ca2+ + Mg2+]-ATPase) of cardiac sarcoplasmic reticulum (SR) has been investigated using direct laser excited Eu3+ luminescence. Eu3+ is found to inhibit both Ca2+-dependent ATPase activity and Ca2+-uptake in a parallel manner. This is attributed to the binding of Eu3+ to the high affinity Ca2+-binding sites. The Ki for Ca2+-dependent ATPase is approximately 50 nM. The 7F0----5D0 excitation spectrum of Eu3+ in cardiac SR shows a peak at 579.3 nm, as compared to 578.8 nm in potassium-morpholino propane sulfonic acid (K-MOPS) pH 6.8. Upon binding with cardiac SR, Eu3+ shows an increase in fluorescence intensity as well as in lifetime values. The fluorescence decay of bound Eu3+ exhibits a double-exponential curve. The apparent number of water molecules in the first coordination sphere of Eu3+ in SR is 2.8 for the short component and 1.0 for the long component. In the presence of ATP, a further increase in fluorescence lifetimes is observed, and the number of water molecules in the first coordination sphere of Eu3+ is reduced further to 1.3 and 0.5. The double exponential nature of the decay curve and the different number of water molecules coordinated to Eu3+ for both decay components suggest that Eu3+ binds to two sites and that these are heterogeneous. The reduction in the number of H2O ligands in the presence of ATP shows a change in the molecular environment of the Eu3+-binding sites upon phosphoenzyme formation, with a movement of Eu3+ to an occluded site on the enzyme.  相似文献   

4.
应用普通玻璃微电极和离子选择性微电极,对正常及经过胰岛素处理的中华大蟾蜍卵母细胞膜电位、细胞内Na~+、K~+、Cl~-、H~+等活度及膜对Na~+、K~+的转运系数进行了测定。结果表明,胰岛素在促进蟾蜍卵母细胞发育成熟同时,具有使膜电位降低、细胞内Na~+、Cl~-活度增加、K~+、H~+活度减少及K~+转运系数降低等作用。胰岛素的上述作用可能与膜的通透性改变及膜上钠泵活性和Na~+/H~+交换的改变有关。  相似文献   

5.
The SH-groups in Escherichia coli membrane vesicles, prepared from cells grown in fermentation conditions on glucose at slightly alkaline pH, have a role in the F0F1-ATPase operation. The changes in the number of these groups by ATP are observed under certain conditions. In this study, copper ions (Cu2+) in concentration of 0.1 mM were shown to increase the number of SH-groups in 1.5- to 1.6-fold independent from K+ ions, and the suppression of the increased level of SH-groups by ATP was determined for Cu2+ in the presence of K+. Moreover, the increase in the number of SH-groups by Cu2+ was absent as well as the inhibition in ATP-dependent increasing SH-groups number by Cu2+ lacked when vesicles were treated with N-ethylmaleimide (NEM), specific thiol-reagent. Such an effect was not observed with zinc (Zn2+), cobalt (Co2+), or Cu+ ions. The increased level of SH-groups was observed in the hycE or hyfR mutants with defects in hydrogenases 3 or 4, whereas the ATP-dependent increase in the number of these groups was determined in hycE not in hyfR mutants. Both changes in SH-groups number disappeared in the atp or hyc mutants deleted for the F0F1-ATPase or hydrogenase 3 (no activity of hydrogenase 4 was detected in the hyc mutant used). A direct effect of Cu2+ but not Cu+ on the F0F1-ATPase is suggested to lead to conformational changes or damaging consequences, increasing accessible SH-groups number and disturbing disulfide-dithiol interchange within a protein-protein complex, where this ATPase works with K+ uptake system or hydrogenase 4 (Hyd-4); breaks in disulfides are not ruled out.  相似文献   

6.
The highly cooperative nature of Ca2+-dependent exocytosis is very important for the precise regulation of transmitter release. It is not known whether the number of binding sites on the Ca2+ sensor can be modulated or not. We have previously reported that protein kinase C (PKC) activation sensitizes the Ca2+ sensor for exocytosis in pituitary gonadotropes. To further unravel the underlying mechanism of how the Ca2+ sensor is modulated by protein phosphorylation, we have performed kinetic modeling of the exocytotic burst and investigated how the kinetic parameters of Ca2+-triggered fusion are affected by PKC activation. We propose that PKC sensitizes exocytosis by reducing the number of calcium binding sites on the Ca2+ sensor (from three to two) without significantly altering the Ca2+-binding kinetics. The reduction in the number of Ca2+-binding steps lowers the threshold for release and up-regulates release of fusion-competent vesicles distant from Ca2+ channels.  相似文献   

7.
The early activation of Na+,K+-ATPase-mediated ion fluxes after concanavalin A (ConA) stimulation of pig lymphocytes is caused by an increase in intracellular Na+ concentration. A second mechanism of regulation of Na+,K+-ATPase activity becomes apparent between 3 and 5 h after mitogenic stimulation, but prior to onset of increase in cell volume; this consists of an increase (about 75%) in the number of ouabain-binding sites (from 35 X 10(3) +/- 12 X 10(3)/cell in resting to 60 X 10(3) +/- 27 X 10(3)/cell in activated lymphocytes). The increase in ouabain binding was attributed to an increase in the number of active Na+,K+-ATPase molecules, based on the following evidence: there was an increase in the Vmax of ouabain binding, without variation in the Km; the increase in ouabain binding was accompanied by a proportional increase in K+ influx, when the assay was performed in the presence of the Na+ ionophore monesin, which was used to eliminate the difference in intracellular Na+ concentration between resting and activated cells; there was proportionality between ouabain-inhibitable ATPase activity in permeabilized cells and the number of ouabain-binding sites in resting and activated lymphocytes. The ConA-induced increase in ouabain-binding sites was influenced neither by amiloride nor by incubation in low Na+ medium, under conditions which prevented both increase in intracellular Na+ concentration and K+ influx. Increase in intracellular Na+ concentration was ineffective in altering the number of active pump molecules in resting cells. During incubation with ConA, the presence of ouabain did not affect the increase in ouabain-binding sites; thus, regulation of the number of pump sites is independent of the regulation of their activity. The ConA-induced increase in number of ouabain-binding sites did not require protein synthesis; indeed, cycloheximide, anisomycin, and puromycin, under conditions in which they inhibited protein synthesis by by 95%, induced the increase to approximately the same extent as did ConA. This suggests the presence in resting lymphocytes of a rapidly turning over protein that either prevents the ATPase subunits from assembling or from integrating into the membrane.  相似文献   

8.
Twenty-four hour changes in lysozyme level, total plasma protein concentration, gamma-globulin concentration, leucocyte number and different forms of leucocyte in the peripheral blood of male chinchillas and rabbits were investigated. All investigated parameters in both species showed statistically significant 24-hr changes, but only total plasma protein concentration in rabbits and gamma-globulin concentration and leucocyte number in chinchillas have a circadian rhythm character. The cosine curve characteristics for these rhythms are as follows; acrophases 0.45 + 2.18 hr, 10.02 + 4.29 hr, 2.14 + 3.20 hr; amplitudes 0.48 + 0.32 g%, 0.34 + 0.41 g%, 1.12 + 0.88 X 10(3)/min3; mesors 6.10 + 0.22 g%, 2.23 + 0.21 g%, 8.78 + 0.65 X 10(3)/mm3, respectively.  相似文献   

9.
Reported in the present paper are chromosome numbers and karyotypes of three genera of the Gesneriaceae, i.e. Ancylostemon Craib. , Briggsiopsis (Franch.) K. Y. Pan and Lysionotus D. Don. The former two genera are endemic to China. The karyotype of Ancylostemon aureus (Franch.) Burtt is formulated as 2n = 34 = 20m(1sat) + 14sm, with the same chromosome number as its allied species A. convexus Craib. This species is characterized by the interphase nucleus of complex chromocenter type and the proximal type of chromosomes in the mitotic prophase. The chromosome number of the monospecific genus Briggsiopsis is 2n = 34, the same as the lowest chromosome number reported in Briggsia. The karyotype of Briggsiopsis, which is formulated as 2n = 25m + 6sm + 3st, also seems to be primitive among the species of the two genera. Briggsiopsis is characterized by the interphase nucleus of simple-complex chromocenter type and the interstitial-gradient type of chromosomes in the mitotic prophase. The chromosome number of Lysionotus carnosus Hemsl. is the lowest reported in this genus. Its karyotype is formulated as 2n= 30 = 21m + 5sm + 3st + lt. Lysionotus serratus var. pterocaulis, with the karyotype being formulated as 2n= 32 = 2lm + 10sm + lt, has the same chromosome number as var. serratus. These two species show a remarkable differentiation of karyotypes and are characterized by the interphase nuclei of simple-complex chromocenter type and the gradient type of chromosomes in the mitotic prophase. _ .  相似文献   

10.
Endocrine control of follicular growth was studied in mature Romanov ewes carrying (RF+) or not carrying (R+2) the Booroola Fec gene during an oestrous cycle after gonadotrophin-dependent follicles were suppressed by treatment with an antagonist of GnRH (Antarelix, 0.5 mg per day) and superovulatory treatment was administered. The left ovary was removed after 10 days of treatment (saline or Antarelix) and the right ovary was removed at the end of the superovulatory treatment. Ewes of both genotypes treated with Antarelix had lower plasma LH concentrations than did controls from day 0 to day 10. The inhibitory effect of Antarelix on LH concentration increased with day of treatment. The variability in FSH concentrations during the initial 10 days was reduced by Antarelix treatment in both genotypes. Plasma FSH concentrations were higher in RF+ ewes than in R+2 ewes. In both genotypes, FSH concentrations varied significantly with day of treatment, with the lowest concentrations at day 8 and the highest concentrations at day 5. RF+ ewes had a greater total and atretic number of antral follicles 0.62-1.12, 1.12-2.00 and 2.00-3.00 mm in diameter (classes 2, 3 and 4) than did R+2 ewes before and after superovulatory treatment. After superovulatory treatment, the total number of atretic and non-atretic follicles > 3.00 mm in diameter (class 5) increased in both genotypes. Superovulatory treatment also increased the number of total and atretic class 4 follicles in RF+ only. Conversely, superovulatory treatment decreased the mean number of class 3 follicles in both genotypes, while the number of atretic follicles was decreased only in R+2 ewes. Antarelix treatment significantly reduced the percentage of follicles > 2.00 mm in diameter in RF+ but not in R+2 ewes. Antarelix treatment before superovulatory treatment increased the total number of class 4 follicles in both genotypes but the increase was more significant in RF+ than in R+2 ewes. These results indicate that Antarelix pretreatment favours a greater superovulatory response in Romanov ewes carrying the Fec gene because ovulatory follicles are recruited from a wider range of follicular size classes.  相似文献   

11.
The daily change in both percentage and absolute number of circulating major lymphocyte subset was determined with young Japanese monkeys and rhesus monkeys. The blood sample was collected at four hour-intervals beginning at 16:00 for 24 hours under the condition of applying tethering system by which blood samples could be collected without restraint. During the dark period (from 20:00 to 08:00), the number of peripheral lymphocytes increased and that of granulocytes decreased, resulting in no significant change in the number of total peripheral white blood cells. The absolute number of CD4 + T, CD8 + T, and CD20 + B cells showed the significant daily change similar to that in number of peripheral lymphocytes, indicating no proportional change in these subsets. The typical proportional change was observed in CD16 + natural killer (NK) cells and the percentage of CD16 + cells decreased during dark period (from 20:00 to 04:00) and increased in the morning (from 08:00 to 12:00). The NK activity determined by killing K562 target cells showed the same changing pattern as that of percentage in CD16+ NK cells. The changing pattern of both percentage and activity of NK cells was consistent with that of plasma cortisol levels. In addition, the intravenous injection of 300 μg/kg of cortisol induced increase in plasma cortisol levels and decrease in percentage of CD16 + NK cells during the first 60 min after cortisol injection. These results strongly suggest that the levels of peripheral functional CD16 + NK cells might be directly regulated by plasma cortisol level in macaque monkeys.  相似文献   

12.
本文对p=h~2+hk+k~2,T=pf~2,C=10T+2和C=10p(n-1)~2+2几个公式进行了新的推导和计算,并对其公式间的关系和每个参数的数学含义作了说明,进而澄清了一些模糊认识,加深了对公式的理解和运用。  相似文献   

13.
In a model of staphylococcal pneumonia initiated during systemic endotoxemia in BALB/c mice, a significant reduction of the number of circulating CD4+ and CD8+ T-lymphocytes, B-lymphocytes, and NK cells, as well as lung-resident total T- and CD4+ T-lymphocytes was demonstrated. Staphylococcus aureus exposure only induced a similar decrease of lymphocyte subsets in the blood. However, the number of lung-resident total T- and CD4+ T-lymphocytes was increased. More viable bacteria were recovered from the lungs of S. aureus-infected mice than from those animals previously treated with lipopolysaccharide (LPS) followed by a staphylococcal challenge. These results indicate that LPS-induced reduction in the number of circulating lymphocyte subsets and lung-resident total T- and CD4+ T-lymphocytes do not increase susceptibility to staphylococcal respiratory infection. Moreover, LPS challenge prior to S. aureus exposure significantly improves clearance of the bacteria in the lung.  相似文献   

14.
Ouabain-sensitive Rb+ uptake and [3H]ouabain binding were used to measure rates of Na+ pumping and the number of pump sites, respectively, in thoracic aortae from opossums. From the number of Rb+ ions pumped per site per minute, estimates of pump turnover have been made. Values obtained are comparable to those of other species (see Table 1).  相似文献   

15.
We have investigated the possibility that cellular control of membrane excitability involves feedback mechanisms in which the degree of activity of voltage-sensitive Na+ channels regulates the number of these channels. Using two independent assays, channel-mediated Na+ uptake and the specific binding of [3H] saxitoxin, we have studied the effects of pharmacological activation of Na+ channels with batrachotoxin (BTX) on the number and properties of these channels. Upon exposure of cultured muscle cells to BTX (1 microM), the number of surface Na+ channels decreases by approximately 75%, with a half-time of 3-6 h. This decrease is prevented by pharmacological blockade of these channels and does not reflect changes in the apparent affinities towards either BTX or saxitoxin. This reduction is reversible: a gradual increase in surface Na+ channels that is dependent on protein synthesis is observed upon removal of the activator. The BTX-induced decrease in Na+ channels is associated with an enhanced rate of disappearance of surface Na+ channels. These findings point to the existence of a down-regulation mechanism for the modulation of membrane excitability under conditions of elevated Na+ channel activity.  相似文献   

16.

7种铁线莲的染色体研究

  总被引:5,自引:0,他引:5  
本文描述了我国产毛茛科铁线莲属的7个种的染色体数目和形态。其核型公式分别为:芹叶铁线莲和宽芹叶铁线莲为2n(2x)=16=10m+6st(2SAT);黄花铁线莲和棉团铁线莲及山木通为2n(2x)=10m+4st+2t(2SAT);圆锥铁线莲为2n(2x)=32=20m+8st(2SAT)+4t(2SAT);吴兴铁线莲为2n(4x)=32=20m+6st(4SAT)+6t(4SAT);本文还讨论了一些种的分类问题。  相似文献   

17.
豆天蛾田间饲养量及效益研究   总被引:9,自引:0,他引:9  
通过对豆天蛾在田间笼罩条件下的饲养调查观察 ,测定出其幼虫食叶量、食叶率 ,从而计算出每平方米豆田的理论养虫量 ,实际适宜养虫量及对大豆产量损失的影响。笼罩条件养虫量 (x)与食叶率(y1)回归方程 :^y1=2 2 0 + 2 4 1x± 2 874 9,r1=0 9971 ;笼罩条件养虫量 (x)与产量损失率 (y2 )回归方程 :^y2 =1 5 7+ 0 4 2 5x± 0 6 837,r2 =0 994 6 ;笼罩条件养虫量 (x)与结荚损失率 (y3 )回归方程 :^y3 =1 5 7+ 0 33x± 1 785 4 ,r3 =0 94 6 8 。在幼虫饲养量为 1 0~ 1 5头 m2 时 ,综合效益比一般豆田每 6 6 7m2增收 4 73 6元以上。  相似文献   

18.
桃AFLP技术体系的优化及集群分离分析研究   总被引:10,自引:0,他引:10  
在以桃为试材,优化AFLP技术体系及集群分离分析的研究中。研究得出:(1)高质量的基因组DNA、预扩增及选择性扩增模板的适宜浓度足影响分析结果的重要因素;(2)预扩增引物可选择E O/M O或E O/M 1组合。对扩增条带数的影响不显著;(3)选择性扩增引物组合E 2/M 3、E 3/M 3均适合桃基因组比较研究。但从揭示的多态性来说还是前者较高;(4)组建近等基因池的个体数将影响标记的筛选效率,试验叶中由6株个体组成的近等基因池较适宜多态性片段的筛选。  相似文献   

19.

Purpose

FOXP3+ regulatory T cells (Treg) play an essential role in modulating host responses to tumors and infections. The role of these cells in the pathogenesis of MALT lymphomas remains unknown. The aims of the study were to quantify the number of infiltrating FOXP3+ and CD3+ cells in patients with gastric MALT lymphoma at diagnosis and to study kinetics of these cells and CD20+ tumor cells after treatment and during long-term follow-up.

Methods

FOXP3+, CD3+ and CD20+ cells were analyzed by immunohistochemistry and the number of cells was quantified using a micrometric ocular. Samples of 35 patients with gastric MALT lymphoma at diagnosis and after treatment were included. Diagnostic samples were compared to 19 cases of chronic gastritis and diffuse large B-cell lymphoma (DLBCL) of the stomach.

Results

The median number of FOXP3+ infiltrating cells was higher (27 cells/cm2) in gastric MALT patients than in DLBCL (10 cells; p = 0.162) but similar to chronic gastritis (20 cells; p = 0.605). No characteristic or specific distribution pattern of infiltrating FOXP3+ cells was found. Gastric MALT lymphoma patients responding to bacterial eradication therapy had higher number of FOXP3+ cells at study entry. Kinetics of both infiltrating FOXP3+ cells and tumor CD20+ cells were strongly dependent on the treatment administered.

Discussion

Gastric MALT lymphomas have a number of Treg cells more similar to chronic gastritis than to DLBCL. Patients with higher number of tumor infiltrating FOXP3+ cells at study entry seem to have better response to antibiotics. Kinetics of Treg and tumor cells are influenced by type of treatment.  相似文献   

20.
In 93 persons aged 90 to 103 years old the subpopulation compositon of lymphocytes and the level of thymic serum activity (TSA) was studied. In the presence of polymorbidity the low level of TSA was observed in 81% of examinees, with the quantitative deficiency in the relative and absolute number of CD3+CD8+ T-lymphocytes (62% and 78% respectively) and the excess in the number CD3+CD4-CD8- T-lymphocytes (42% and 57% respectively). Among CD3+CD4-CD8- T-lymphocytes cells with phenotypes CD3+/-CD4-CD8-CD16- and CD3+CD4-CD16+ were determined. In prolonged imunomonitoring the reciprocacity of changes in the amount of CD3+/-CD4-CD8-CD16- T-lymphocytes was established in relation to the level of TCA and the number of CD3+CD8+ T-lymphocytes. The reversibility of these changes is indicative of the potential of reactivity of the immune system in longlivers. The positive result of laser therapy in persons with quantitative deficiency of CD3+CD8+ T-lymphocytes and the presence of cells with phenotype CD3+/-CD4-CD8-CD16- was associated with the restoration of the size of CD3+CD8+ subpopulation and a decrease in an amount of CD3+/-CD4-CD8-CD16-. The unfavorable prognostic sign was, seemingly, the quantitative deficiency of CD3+CD8+ T-lymphocytes with the low level of TCA in the absence of CD3+/-CD4-CD8-CD16- T-lymphocytes.  相似文献   

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