Compatibility of the F-like plasmid FB1drd with standard F-group plasmids in E. coli K12 strains]

Compatibility of depressed F-like plasmid FB1drd integrated into E. coli K12 cell chromosome with standard plasmids of FI-FVI compatibility groups was studied. The results obtained show that such plasmids can stably coexist in the same cell with plasmid FB1drd. On these grounds it is supposed that the latter belongs to the new compatibility group (FVII).     

肝素结合表皮生长因子抑制剂CRM197 对裸鼠卵巢癌移植瘤 的抑制作用

目的:研究CRM197对裸鼠卵巢癌移植瘤生长的抑制作用探讨其对逆转卵巢癌组织耐药作用及其在卵巢癌治疗中的可行性.方法:用人卵巢癌亲本细胞A2780、耐紫杉醇细胞A2780/Taxol及耐顺铂细胞A2780/DDP分别建立裸鼠卵巢癌移植瘤模型,观察注射CRM197组与阴性对照组裸鼠肿瘤生长情况,免疫组化法测定各组裸鼠肿瘤组织中HB-EGF及P-gp表达情况.结果:HB-EGF及P-gp在各肿瘤组织中不同程度的表达,在注射CRM197的裸鼠肿瘤组织中表达明显降低(P＜0.05),差异具有统计学意义.结论:CRM197通过抑制肝素结合表皮生长因子的信号传导通路激活抑制了裸鼠卵巢癌移植瘤的生长,使裸鼠卵巢癌移植瘤HB-EGF及P-gp表达明显降低.     

特异性人端粒酶催化亚单位基因小干扰RNA对HeLa细胞生长的抑制作用

通过设计并化学合成人端粒酶催化亚单位(hTERT)特异性siRNA,观察其对hTERT表达水平及肿瘤细胞生长的影响。将hTERT-siRNA以脂质体法转染入HeLa细胞,应用RT-PCR、实时定量TRAP、Western印迹、软琼脂克隆形成实验、荷瘤裸鼠肿瘤内注射等方法检测细胞内hTERTmRNA、蛋白质表达水平及对肿瘤细胞生长的影响。RT-PCR、实时定量TRAP和Western印迹的结果显示hTERT-siRNA明显降低了HeLa细胞内hTERT的mRNA及蛋白质表达水平并伴随有端粒酶活性的下降。克隆形成实验表明hTERT-siRNA组的体外肿瘤形成能力受到抑制。荷瘤裸鼠肿瘤内注射hTERT-siRNA使肿瘤平均体积显著小于对照组。TUNEL凋亡检测表明hTERT-siRNA转染组的凋亡率明显高于对照组。研究表明hTERT特异性siRNA可以明显抑制HeLa细胞内hTERT的表达水平,对其生长有明显抑制作用,是一种有前途的肿瘤治疗新方法。     

The effects of amiloride on the labellar taste receptor cells of the fleshfly Boettcherisca peregrina

Amiloride is known to inhibit the taste response of vertebrates to salt by blocking the amiloride-sensitive sodium channel. In this study, we investigated electrophysiologically the effect of amiloride on the taste response of the fleshfly Boettcherisca peregrina. When 0.5 mM amiloride was included in taste solutions, the response of the salt receptor cell (salt response) to sodium chloride (NaCl) was not depressed but those of the sugar receptor cell (sugar responses) to sucrose, glucose, fructose, l-valine (l-Val) and l-phenylalanine (l-Phe) were strongly depressed. An inhibitory effect of amiloride on the concentration-response relationship for both sucrose and l-Phe was clearly revealed, but not at high concentrations of sucrose. After pretreatment of a chemosensory seta with 0.15 mM amiloride for 10 min, the salt response to NaCl was not affected. On the other hand, the sugar responses to sucrose, fructose, l-Val and l-Phe were depressed just after amiloride pretreatment. The sugar response to adenosine 5’-diphosphate (ADP) mixed with 0.5 mM amiloride was not depressed, but the response to ADP alone was depressed after amiloride pretreatment. It was therefore observed that amiloride depressed the responses to all stimulants that react with each of the receptor sites of the sugar receptor cell.     

慢性应激抑郁大鼠学习记忆及海马非对称性超微结构的改变

目的：探讨慢性不可预见性应激抑郁模型大鼠大脑海马非对称性超微结构与学习记忆能力的改变。方法：SD雄性大鼠20只,随机分为正常对照组与抑郁模型组,每组10只。采用慢性轻度不可预见性应激21d及单笼饲养方法建立抑郁模型,应激前以及应激21d末对两组大鼠进行旷场实验、液体消耗实验及体重测量,对大鼠进行避暗穿梭实验,测试其学习记忆能力,之后活杀动物,取出大鼠左右海马,制作常规电镜标本,观察海马超微结构的改变。结果：在穿梭变实验中抑郁大鼠学习记忆潜伏期减少,进入暗箱错误积分增多。抑郁大鼠左右侧海马超微结构中左侧海马较正常对照组神经细胞及胶质细胞变化明显,表现为内质网扩张,溶酶体增多。而右侧海马远不及左侧损伤严重。结论：慢性不可预见性应激抑郁大鼠学习记忆能力显著下降,其可能与海马组织在应激过程受到的累积损伤有关,且抑郁大鼠海马损伤呈非对称表现。     

Infection with Bacillus Calmette-Guérin activates murine thymus-independent (B) lymphocytes.

Thymus-independent (B) lymphocytes from BCG-infected mice respond with enhanced or depressed levels of proliferation relative to the nonspecific levels of stimulation induced by tuberculin. The type of response obtained depends on how BCG was administered and the source of the lymphocytes. The proliferation of splenic B lymphocytes was depressed when BCG was given i.v. and unchanged when BCG was given subcutaneously, whereas the lymph node B cell response was enhanced regardless of the route of injecting BCG. BCG was found also to be a mitogen for normal B cells in vitro and to stimulate polyclonal activation of B cells in vivo. Finally, evidence is presented which indicates that the depressed splenic B cell response to tuberculin may be due to the activation of suppressor T cells.     

阿托品压抑疗法和遮盖疗法在治疗小儿弱视中的效果观察

目的:探讨遮盖疗法与阿托品压抑疗法治疗儿童弱视后视功能的变化差异。方法:90例单纯屈光参差弱视儿童随机分为压抑组和遮盖组各45例,两组弱视眼均佩带适矫眼镜,压抑组采用优势眼采用阿托品完全压抑法,遮盖组优势眼6h/日遮盖治疗,均连续治疗6个月,比较两组患儿视力变化情况。结果:治疗后压抑组的视力-0.044±0.137显著优于遮盖组视力-0.217±0.196(P0.05)。压抑组治疗后的P-VEP潜时、P-VEP振幅分别为105.3±4.9(ms)、14.8±3.6(uv)显著优于遮盖组(P0.05)。压抑组的立体视重建疗效分布显著的优于遮盖组(P0.05),压抑组的有效率80%显著的高于遮盖组的60%(P0.05)。压抑组的疗效分布显著的优于遮盖组(P0.05),压抑组的有效率84.44%显著的高于遮盖组的57.78%(P0.05)。结论:阿托品压抑疗法治疗弱视儿童较遮盖疗法具有更加显著的治疗效果。     

The Influence of Specific Bacteria and a Filterable Agent on the Growth of Gnotobiotic Chicks

Growth depression was induced in chicks and a collection of aerobic and anaerobic bacteria was isolated from the crop and caecum. The collection of bacteria was tested in gnotobiotic chickens for its ability to depress growth with and without a bacteria-free faecal filtrate. None of the anaerobic bacteria depressed growth. Aerobic bacteria always depressed growth but only in the case of Streptococcus faecium was this statistically significant. The faecal filtrate also depressed growth. A statistically significant effect was obtained when faecal filtrate was combined with any of the following treatments: (a) the total collection of bacteria, (b) the aerobic group, (c) the anaerobic group, (d) Strep. faecalis var. liquefaciens , (e) Strep, faecium , (f) the unclassified streptococci, and (g) a group containing the lactobacilli and coliform organisms. The largest growth depression was obtained in chickens dosed with Strep, faecium and faecal filtrate.     

Determination of Kupffer cell Fc receptor function in vivo following injury

This study was carried out to determine whether Kupffer cell Fc receptor function is depressed after injury. Three approaches to the determination of Fc receptor function were evaluated: IgG-coated erythrocytes (EIgG) were used as the receptor probe with a perfused liver system, EIgG were used as the receptor probe in vivo, and small aggregates of IgG (AIgG) were used as the receptor probe in vivo. Nearly half of the injected dose of EIgG was taken up by the perfused liver (nonrecirculating, serum-free system). In contrast, only 2.6% of erythrocytes not coated with IgG were taken up, and only 5.6% of erythrocytes coated with IgM were taken up by the perfused liver. Thus, there was little nonspecific or complement-dependent uptake of EIgG by the liver. The uptake of EIgG by the perfused liver was depressed following thermal injury, endotoxemia, and the phagocytosis of EIgG. These results were interpreted as indicating that Kupffer cell Fc receptor function was depressed under these conditions. The results obtained with the hepatic uptake of EIgG in vivo were very similar to those with EIgG in the perfused liver. However, since it was found that complement receptors as well as Fc receptors were probably involved in the in vivo clearance of EIgG, these results could be due to a depression of one or both of these receptors. The hepatic uptake of AIgG was not depressed by complement depletion, but was decreased by the injection of large aggregates of IgG. However, the hepatic uptake of AIgG was not depressed following thermal injury, endotoxemia, or the phagocytosis of EIgG. Thus, AIgG was not sensitive to the effects of injury on Kupffer cell function, whereas the uptake of EIgG by the perfused liver may provide an indication of Kupffer cell Fc receptor function. The depression of Kupffer cell Fc receptor function following injury may contribute to the impairment of host defense caused by injury.     

Some haematological responses of normal and splenectomized rainbow trout Salmo gairdneri to a 12% blood loss

Anaemia can be induced in Rainbow trout by removing 12 % of the blood volume by cardiac puncture. Recovery from such an anaemia has been monitored in both normal and splenectomized fish. After the bleeding there is a decrease in red cell numbers, haematocrit and blood haemoglobin concentration. Although recovery in normal trout was not complete within 27 days, which was the period of the observations, it was seen as a replenishing of red cell numbers, haematocrit and blood haemoglobin concentration. Mean corpuscular haemoglobin (MCH) and mean corpuscular haemoglobin concentration (MCHC), both depressed by the bleeding, did not appear to recover during the experimental period.
Splenectomy reduced erythropoietic intensity. After bleeding all the parameters studied were more depressed than those found in normal trout, and recovery was not noted. Blood haemoglobin and red cell numbers did not have the same post-bleeding pattern as normal individuals; MCH and MCHC values remained markedly depressed.
Splenic involvement was further demonstrated by bleeding trout for a second time from both normal and splenectomized groups. In contrast to the response of normal animals, there was a further deterioration of red cell numbers and blood haemoglobin concentration in splenectomized individuals.     

The specific receptor site for aliphatic carboxylate anion in the labellar sugar receptor of the fleshfly

A two minute treatment of a single sugar receptor cell with 10 mg/ml pronase did not affect its response to d-fructose, but depressed markedly its response to l-valine. This is the first direct evidence for a specific site for certain aliphatic amino acids.All six amino acids that can stimulate the sugar receptor were examined and classified into two groups according to the presence or absence of the inhibitory effects of pronase treatment. Responses to certain aliphatic amino acids and a corresponding fatty acid were depressed whereas responses to phenylalanine and trytophan were not. Further evidence for the existence of two classes of amino acids comes from the fact that the α amino group of valine is not essential whereas that of phenylalanine is. It was concluded that the first class of amino acids react with a specific receptive site for carboxylate anions whereas the second react with the furanose site.     

Assessing psychosocial factors in depressed patients--accordance of patient's and physician's assessment

Aim of this study was to investigate the differences in the assessment of psychosocial factors by depressed and non depressed patients, and their congruence with physicians' assessment for both groups. The cross-sectional study was conducted in three family physicians' practices in Zagreb, Croatia, during 2007. Sample of depressed patients included 76 patients out of 85, and randomized comparison group of 189 out of 235. Questionnaire recommended by the European Guidelines on Cardiovascular Disease Prevention in Clinical Practice was used for the assessment of psychosocial factors. Depressed patients significantly more frequently reported about social isolation (p(alone) = 0.013; p(close confident) = 0.005; p(help) = 0.001), family stress (p < 0.001), work stress (p(appropriate reward) = 0.029) and lower life satisfaction (p < 0.001) than non depressed. Their worse psychosocial functioning was noticed by family physicians who assessed social isolation (p(alone) = 0.013; p(close confident) = 0.032), family stress (p < 0.001) and life satisfaction (p < 0.001) significantly lower for depressed patients than for the random sample. Incongruence between family physicians and depressed patients assessment was valued by physicians to be of higher economic status (p < 0.001), and more intense family stress (p < 0.001). Assessment of psychosocial factors varied within the group of depressed patients and the random sample assessed either by themselves or by physicians. Congruence between family physicians and non depressed patients in the assessment of observed psychosocial factors was better than between physicians and depressed patients.     

Influence of thymosin on E-rosette formation of lymphoid cells in leukemic and nonleukemic children.

The influence of two thymosin and two spleen control preparations on the E-rosette formation of peripheral blood lymphocytes and leukemic cells from non-leukemic children with depressed T cell values and leukemic children was investigated. Both thymosin preparations but also one of the control preparations induced a significant increase in the mean percentage of E-rosette forming PBL in the non-leukemic children with depressed T cell values. Thymosin and spleen preparations, however, did not convert the non-erythrocyte binding blasts to erythrocyte binding cells in either common or pre-T-ALL.     

四周模拟失重大鼠后身动脉平滑肌细胞钾电流的改变

本文采用全细胞膜片钳方法观察4周尾部悬吊大鼠（tail-suspended rats,SUS)隐动脉及肠系膜的动脉第2-6级动脉分支血管平滑肌细胞（vascular smooth muscle cells,VSMCs)钾电流密度的变化,结果表明：SUS大鼠后身动脉VSMCs的静息电位（RP）较对照大鼠（CON）后身动脉VSMCs的RP更负,SUS组隐动脉和肠系膜小鼠后身动脉VSMCs的静息电位（RP）较对照大鼠（CON）后身动脉VSMCs的RP更负,SUS组隐动脉和肠系膜小动脉VSMCs的全细胞钾电流密度较CON组显著增加,其中,SUS组的隐动脉和肠系膜小动脉VSMCs的大电导钙激活钙离子通道（BKca)和电压激活钾离子通道（Kv)电流密度较CON组的BKca和Kv电流密度均显著增加,以上结果提示,VSMCs的超极化及进一步引起的通过电压依赖性钙离子通道的钙内流减少可能是模拟失重引起后身动脉反应性降低的电生理机制之一。     

Effects of the induction of experimental cryptorchidism and subsequent orchidopexy on testicular function in immature rats

Cryptorchidism surgically induced in 14-day-old rats, was allowed to persist until 35 days when one group was killed to assess testicular function. In a second group the cryptorchid testis was returned to the scrotum surgically (orchidopexy) and subsequently killed at 130 days. A third group remained persistently cryptorchid to 130 days, while in a fourth group two sham operations were performed at 14 and 35 days. At 35 days, cryptorchidism resulted in a significant decline in testis weight due to suppressed spermatogenesis. Sertoli cell function as measured by seminiferous tubule fluid (TF) production after unilateral efferent duct ligation and androgen-binding protein (ABP) production was significantly depressed in the cryptorchid group. Serum follicle-stimulating hormone (FSH) and luteinizing hormone (LH) levels were significantly elevated with cryptorchidism but serum testosterone levels were unchanged. Although morphometric measurements showed no change in Leydig cells cross-sectioned area, in vitro human chorionic gonadotropin (hCG)-stimulated testosterone production was significantly increased in the cryptorchid group at higher hCG doses. Similar changes were found in cryptorchid testes at 130 days except that Leydig cell cross-sectional area was now significantly increased. Orchidopexy at 35 days restored spermatogenesis and fertility during test mating was not impaired. TF production, ABP accumulation and serum FSH levels returned to normal following orchidopexy.(ABSTRACT TRUNCATED AT 250 WORDS)     

Role of the endothelial glycocalyx in dromotropic, inotropic, and arrythmogenic effects of coronary flow

Coronary flow regulates cardiac functions, and it has been suggested that endothelial membrane glycosylated proteins are the primary shear stress mechanosensors. Our hypothesis was that if these proteins are the sensors for flow, then intracoronary perfusion of lectins or specific antibodies should differentially depress coronary flow-enhanced responses of different parenchymal cell types such as auricular-ventricular (A-V) nodal cells (dromotropic effect), contractile myocytes (inotropic effect), and junctional Purkinje-muscle cells (spontaneous ventricular rhythm). The coronary flow stimulatory effects on A-V delay and spontaneous ventricular rhythm were selectively depressed by six of eight lectins. None of the lectins depressed the coronary flow inotropic effect. Antibodies against endothelial surface proteins, alpha(v)beta(5)-integrin and sialyl-Lewis(b) glycan, depressed the dromotropic but not the inotropic effects of coronary flow, whereas the vascular cell adhesion molecule 1 antibody had no effect on the dromotropic, but enhanced the inotropic, effect. The fact that lectins and antibodies differentially depressed regional coronary flow effects suggests that there is a chemical distinctiveness in their intravascular endothelial cell surfaces. However, nonselective cross-linking of endothelial glycocalyx proteins with 2,000-kDa dextran-aldehyde or vitronectin indistinctively depressed the dromotropic and inotropic effects of coronary flow. These results indicate that coronary flow-induced stress acts on specific structures located in the capillary intravascular membrane glycocalyx.     

T and B lymphocyte populations of tumor-bearing mice treated with 1,3-bis(chloroethyl)-1-nitrosourea (BCNU) or pyran

Summary The immunostimulator pyran copolymer and the antitumor agent 1,3-bis(2-chloroethyl)-1-nitrosourea (BCNU) have been studied to determine their effect on T and B lymphocytes from BALB/c mice bearing a syngeneic tumor, Madison lung 109 carcinoma. Indirect immunofluorescent and mitogenic assays revealed that the tumor-bearing controls usually had T and B cell populations lower than those observed for the normal controls. The tumor-bearing group treated with BCNU generally had T and B cell levels lower than the tumor controls. The administration of pyran resulted in an increase of T cells and a temporary increase in the B cell population. Although this increase in the B cell population of tumor-bearing mice treated with pyran is higher than that seen for the untreated tumor controls it was never higher than in the normal control mice. The experimental results indicate that pyran appears to reconstitute the depressed T cell population and has a transitory effect on the B cell population resulting from tumor burden.     

Immunotoxicity of repeated low level exposure to T-2 toxin,a trichothecene mycotoxin,in CD-1 mice

Male CD-1 mice were gavaged with T-2 toxin (0.0–5.0 mg/kg body weight) every third day. Body weight gain was depressed by exposure to 2.5 mg/kg, or greater, T-2 toxin; this was not associated with decreased food intake. The weights of the liver, kidney, spleen, and thymus were affected by two weeks exposure to T-2 toxin. However, a persistent effect after four weeks was observed only for the thymus. Peripheral leucocyte counts were elevated in the highest dose groups after two and four weeks. Thymidine uptake by cells not simultaneously exposed to mitogen was increased in splenic cell cultures of mice exposed to 2.5 mg/kg T-2 toxin for two or four weeks. Phytohemagglutinin stimulation of splenic lymphocytes following two weeks of exposure was depressed in the 2.5 mg/kg dose group; this phenomenon was not observed after four weeks exposure. Response to pokeweed mitogen increased after four weeks of exposure to 2.5 mg/kg T-2 toxin. A delayed-type hypersensitivity response decreased following two weeks exposure to levels greater than 0.02 mg/kg. Production of I g M class antibodies by splenic lymphocytes, evaluated by a hemolytic plaque response to sheep erythrocytes, was depressed in the 2.5 mg/kg dose group after two weeks exposure to T-2 toxin. The sensitivity and specificity of T-2 toxin immunotoxicity was indicated by the various parameters evaluated.     

Evidence of active transfer of certain non-electrolytes across the human red cell membrane

1. Permeability of the human erythrocyte to glycerol, as indicated by the course of hemolysis and volume changes, is depressed by Cu(++), Hg(++), I(2), p-chloromercuribenzoate, and phlorhizin, without effecting general permeability changes. In so far as tested (Cu(++), p-ClHgB), these inhibitors delay exit of glycerol from the cell as well as its entry. 2. Permeability to glucose is similarly depressed by I(2) and phlorhizin, and is extremely sensitive to Hg(++) and p-chloromercuribenzoate, but is not affected by Cu(++). An extensive series of other enzyme poisons is without effect in either system. 3. The effects of the sulfhydryl inhibitors are prevented or reversed in the presence of glutathione, cysteine, etc. 4. The kinetics of the volume changes in glucose-saline solutions indicates a mechanism for transport of glucose into the cell, regulated by the existing intracellular concentration, rather than by simple diffusion gradients. 5. The intermediation of a sulfhydryl group at the cell surface, probably an enzymatic phosphorylation, is suggested as an essential step in the passage of glycerol, glucose, and other like substances, across the human red cell membrane.     

Effect of copper on activation of human T cells

Immunomodulatory properties of copper were investigated. Human T cells, isolated from blood of healthy donors, were stimulated with phytohemagglutinin and cultured in vitro. It was found that copper sulphate depressed T cell proliferation when added in concentration of 10(-3) M. A slight increase in the T cell proliferation was shown in presence of 10(-5) M of copper ion while 10(-7)-10(-9) M had no effect on proliferation. Production of interleukin 2 by human T cells was depressed by all investigated doses of copper. The obtained results suggest the direct toxicity of copper on T cell activation.