大鼠肠系膜淋巴结高内皮微静脉与淋巴迷路之间的网状纤维支架的研究

目的 研究大鼠肠系膜淋巴结内高内皮微静脉与淋巴迷路之间淋巴细胞归巢的通路.方法 用镀银染色光镜观察法和冻裂割断扫描电镜观察法观察健康、成熟Wistar大鼠肠系膜淋巴结的基质网状结构.结果 位于高内皮微静脉和淋巴迷路周围有网状纤维支架,在二者相临近部位有密集交织的网状纤维网.结论 淋巴结内高内皮微静脉和淋巴迷路之间密集交织的网状纤维网,为细胞的居留和迁移提供结构支持和适宜的微环境,可能是淋巴细胞归巢的重要通路.     

Lymphokine-activated killer cell function of peripheral blood mononuclear cells, spleen cells and regional lymph node cells in gastric cancer patients.

Lymphokine-activated killer (LAK) cells generated by culture of peripheral blood mononuclear cells (PBMC), spleen cells (SPC) and regional lymph node cells (LNC) with IL-2 for 4 days were examined for their functional capabilities in 29 patients with gastric carcinoma. The cytotoxic activity of LAK cells induced from LNC was significantly lower than that from either PBMC or SPC, although there was no difference between PBMC or SPC. The induction of mRNA of interferon-gamma (IFN-gamma) or tumour necrosis factor-alpha (TNF-alpha) and the production of these cytokines in the non-adherent LAK cells from LNC were also significantly reduced compared with those from PBMC or SPC. Further, the LAK cells from LNC secreted significantly lower levels of these cytokines when stimulated with tumour target, Raji cells, although the production of these cytokines was markedly increased by stimulation with the targets in all three cell populations. Phenotypic analysis of each cell population revealed a decreased proportion of the cells mediating natural killer (NK) activity, including CD16+, CD56+, and CD57+ cells in LNC either before or after culture, although OKIa1+ and CD25+ cells were uniformly increased in all cell populations after culture. Changes in subpopulations of CD4+ and CD8+ cells in LNC were not apparently different from PBMC or SPC. These results indicated the differential reactivity of each lymphocyte population to IL-2 and the reduced LAK cell function of LNC compared with PBMC or SPC in patients with gastric carcinoma.     

结核分枝杆菌联合DNA疫苗初免-BCG加强的免疫效果观察

目的:研究并比较结核分枝杆菌免疫保护性抗原DNA(Ag85A和ESAT-6)疫苗联合免疫,BCG免疫以及联合DNA疫苗初免-BCG加强免疫等不同的免疫策略,诱导免疫应答效果观察.方法:健康雌性BALB/c小鼠24只,随机分成PBS 阴性对照组,DNA初免-BCG异源加强组,DNA(Ag85A和ESAT-6)初免DNA同源加强组和BCG阳性对照组,共进行3次免疫,初免2次,最后1次加强,间隔2周1次.PBS组3次均注射PBS 溶液;DNA/BCG组以质粒DNA免疫2次,最后1次以BCG加强免疫;DNA/DNA组3次均以质粒DNA进行免疫;BCG组则注射PBS溶液2次后以BCG免疫.末次免疫后4、6、8周分别分离血清测定总IgG水平,同时分离小鼠脾细胞,体外经TB-PPD刺激后进行淋巴细胞增殖实验(XTT法)并测定脾细胞培养上清中IFN-γ和IL-4水平.结果:DNA/BCG、DNA/DNA、BCG组体外经TB-PPD刺激后均检测到特异性IgG抗体产生,3组平均效价为1:120、1:160、1:80,DNA/DNA组的抗体效价高于另外2组;小鼠脾细胞体外经TB-PPD刺激后,均能产生特异性淋巴细胞增殖并诱生较强的IFN-γ反应,其中DNA/BCG组IFN-γ的分泌水平高于DNA/DNA组和BCG组(P<0.05).结论:联合DNA疫苗初免-BCG加强的免疫策略能在小鼠体内诱导较强的特异性细胞免疫反应,产生高水平的IFN-γ.     

Detection of mutations in Mycobacterium tuberculosis genome determining resistance to fluoroquinolones by hybridization on biological microchips

We developed a method of identification of Mycobacterium tuberculosis with simultaneous evaluation of the sensitivity to fluoroquinolones on a biological microchip array. The method of multiplex two-staged PCR followed by hybridization of a biochip makes it possible to detect 8 mutant variants of gyrA gene occurring in fluoroquinolone-resistant strains (∼85% all resistant forms) within 1 day. Using this method we analyzed 107 cultures isolated from patients with tuberculosis and 78 sputum samples. Mutations in gyrA gene were detected in 48 (92%) resistant strains. Natural S95T polymorphism in gyrA gene was detected in all resistant and in 76% sensitive strains. The sensitivity and specificity of the proposed method calculated on the basis of the analysis of sputum samples (n=78) were 94 and 100%, respectively. __________ Translated from Byulleten’ Eksperimental’noi Biologii i Meditsiny, Vol. 145, No. 1, pp. 115–120, January, 2008     

The developmentally regulated neural crest-associated glycotope HNK-1 predicts metastasis in cutaneous malignant melanoma

Aberrant glycosylation is a common feature of metastatic sub-clones of malignant tumours and in uveal melanoma in particular, the HNK-1 glycotope has been positively correlated with poor prognosis. So far, no such correlation has been investigated in cutaneous melanoma. In order to do so, HNK-1 expression was evaluated immunohistochemically in 100 primary cutaneous melanomas and correlated with metastasis after up to 10-years' follow-up. Furthermore, HNK-1 expression was analysed in metastatic deposits (19 distant cutaneous metastases and six sentinel lymph node metastases), as well as in benign nevi. Kaplan-Meier analysis revealed a positive association between HNK-1 expression and metastasis (p < 0.005) and multivariate Cox regression analysis adjusted for the standard prognostic markers ulceration and vertical tumour thickness confirmed HNK-1 expression as an independent prognostic marker. HNK-1 expression was preserved in 42% of the distant cutaneous metastases, but metastatic cells in lymph nodes were devoid of HNK-1 immunoreactivity. None of the benign pigmented lesions exhibited HNK-1 immunoreactivity. Expression of the HNK-1 glycotope in cutaneous malignant melanoma is an independent prognostic marker of metastasis. Differential HNK-1 expression at the metastatic sites implies that its expression is modulated by the surrounding environment. As HNK-1 is also transiently expressed during migration of melanocyte precursor cells derived from the neural crest, recapitulation of this transient expression might occur during metastatic spread of cutaneous malignant melanoma.     

HIV coinfections with tuberculosis among HIV-1 infected individuals in old cross river state,Nigeria

ABSTRACT

Human immunodeficiency virus (HIV) and Tuberculosis (TB) are two main global public health threats that dent development in low and middle-income countries. This study evaluated the HIV/TB co-infection rate among HIV-1 infected individuals in old Cross River State, Nigeria. A total of 417 HIV-infected individuals participated in this study, 241 (57.8%) from Calabar, Cross River State, Nigeria and 176 (42.2%) from Uyo, Akwa-Ibom State, Nigeria. The age range of the 417 HIV-1 positive individuals who participated in the study was 4–72 years with an average age of 39.1 years. Plasma samples were analyzed for HIV and TB using fourth-generation Enzyme-Linked immunosorbent Assay. The CD4 count was enumerated using the Partec CyFlow® Counter. Plasma viral loads (PVL) were determined using the Abbott Real-Time HIV-1 assay. Results showed that 230 (55.2%) of the participants were in the 31–45 years age range. The majority (67.4%) of the HIV-1 infected individuals were females and 32.6% were males. An overall prevalence of HIV/TB coinfection in Old Cross River State, Nigeria was 1.4%, with Akwa Ibom State (0.6%) and Cross River State (1.2%). A higher prevalence of HIV/TB coinfection was observed among females (1.8%) than in males (0.7%). Higher prevalences of HIV/TB coinfections was observed in patients above 45 years of age (2.2%), married (2.3%), tertiary education (1.8%) followed by those with secondary education (1.4%), traders and civil servants (3.1%), patients with CD4 counts 200–349 and ≥500 cells/μl (1.9%), and those with viral load <40 copies/mL (2.7%). This study confirmed the presence of HIV/TB co-infection in old Cross River State, Nigeria. Although the prevalence rate of HIV/TB coinfection was low, its presence alone among HIV-1 infected individuals makes it a major source of concern. This finding highlights the need for a well-structured approach to the management of co-infection, and this includes both the social and medical aspects of the problem.     

High antibody levels to the mycobacterial fibronectin-binding antigen of 30-31 kD in tuberculosis and lepromatous leprosy.

Immunoblot assays showed that mycobacterial fibronectin-binding antigens are important targets of the humoral immune response in tuberculosis and leprosy. Using culture filtrate antigens of Mycobacterium tuberculosis, strong reactivity with the fibronectin-binding of 30-31 kD (Fn 30-31) was demonstrated in 55.9% of tuberculosis sera and in 56.5% of lepromatous leprosy sera. Sera from patients with tuberculoid leprosy and control sera gave very weak binding. Reactivity of tuberculosis and lepromatous leprosy sera with the fibronectin-binding antigen of 58-60 kD (Fn 58-60) was less conspicuous. The ability to react with fibronectin of the antigens of 58-60 and 30-31 kD was demonstrated by parallel labelling with a fibronectin-biotin conjugate. Fn 30-31 was purified to homogeneity by a two-step procedure and used for ELISA. Positive titres were found in 63% out of 65 tuberculosis sera and in 60.5% out of 43 lepromatous leprosy sera. Antibody titres in lepromatous leprosy sera were higher than in tuberculosis sera. Our observations indicate indirectly that M. leprae possess a highly immunogenic molecule homologous to M. tuberculosis Fn 30-31, which elicits a high antibody response in lepromatous leprosy but not in tuberculoid leprosy. In this investigation, direct evidence for the presence of this antigen in M. leprae was obtained by immunochemistry of lepromatous leprosy lesions with a monospecific antibody raised against M. tuberculosis Fn 30-31.     

Patterns of major histocompatibility complex class II expression by T cell subsets in different immunological compartments. 2. Altered expression and cell function following activation in vivo

This study characterizes antigen-induced phenotypic and functional aspects of major histocompatibility complex (MHC) class II expression on recirculating T cells in efferent lymph. In vivo secondary, but not primary challenge is associated with both kinetic and phenotypic alterations in class II expression by T cells. All three major T cell subsets, CD4⁺, CD8⁺ and T19⁺ (γδ T cell receptor), show an approximate four fold increase in the level of MHC class II expression during secondary responses. No changes in B cell expression of class II were seen. Resting efferent lymph T cells are predominantly either class II^? or DR⁺DQ^? but this changes to DR⁺DQ⁺ after antigenic challenge. The antigen-presenting function of these class II⁺ T cells was investigated at daily intervals after in vivo antigenic challenge. T cells from non-activated lymph nodes could not induce proliferation of antigen-specific T cells with soluble antigen but were weakly stimulatory in allo-mixed lymphocyte reaction (MLR) at high (> 2:1) stimulator cell ratios. Activated T cells isolated during secondary in vivo responses, and expressing increased quantities of MHC class II, were positive stimulator cells in the MLR. In contrast these cells could not present soluble antigen or trypsin-digested antigen to the T cell lines. In the MLR assays, the relative stimulation by class II⁺ T cells correlates with the levels of class II expression. We conclude from these experiments that both quantitative and qualitative changes in MHC class II, induced on T cells under physiological conditions, play a role in the regulation of the immune response in vivo but that that role is not simply one of presentation of soluble antigen.     

大鼠腘窝淋巴结内淋巴滤泡的生后发育

目的:研究大鼠淋巴结淋巴滤泡的生后发育.方法:采用常规组织学、免疫细胞化学及三维重建技术研究了大鼠腘窝淋巴结内淋巴滤泡的发生.结果:生后18天始,淋巴结浅层皮质内sIgM阳性B淋巴细胞聚集形成初级淋巴滤泡.生后3周ED-5阳性滤泡树突状细胞出现.随着鼠龄及体重的增长,初级淋巴滤泡不断扩大,每个淋巴结内淋巴滤泡数亦增多.生后13周滤泡数达高峰,平均每个淋巴结86个,13周以后体重缓慢增长,淋巴滤泡数逐渐下降.生后8周时,次级淋巴滤泡出现,ED-5阳性滤泡树突状细胞主要分布于亮区.结论:初级淋巴滤泡形成过程中B淋巴细胞聚集可能诱导局部网状细胞分化成滤泡树突状细胞;发育期间淋巴滤泡数随体重增长而增加可能与某些决定机体生长的因素作用有关.     

Monovalent cation conductance of the sustained inward current in rabbit sinoatrial node cells

 Under the whole cell clamp, superfusion of the rabbit sinoatrial node cells with a Na⁺-free solution suppressed the sustained inward current (I_st), and the L-type Ca²⁺ current (I_Ca,L) could be recorded on depolarization less negative than –40 mV from the holding potential of –80 mV. On the other hand, replacement of Ca²⁺ with Mg²⁺ in the external solution suppressed inward-going I_Ca,L and isolated I_st. Under this condition, I_st measured as a nicardipine-sensitive current showed an activation threshold between –60 and –70 mV. The conductance sequence of I_st for monovalent ions was determined as Na⁺ > Li⁺ >> K⁺ @ Cs⁺ by replacing the external Na⁺ with these alkali metal ions. The contribution of I_st to the diastolic depolarization is discussed. Received: 12 June 1996 / Received after revision: 31 July 1996 / Accepted: 7 August 1996