Transjugular percutaneous inoue balloon mitral commissurotomy in a patient with inferior vena cava obstruction after liver transplantation.

Percutaneous transvenous mitral commissurotomy was performed successfully via the transjugular approach in a patient with severe rheumatic mitral stenosis and obstruction of the inferior vena cava due to prior liver transplantation. This case demonstrates the advantage of the jugular approach in patients with difficult anatomy.     

HIV epidemic in Central African Republic: high prevalence rates in both rural and urban areas

A sentinel serosurveillance study was conducted in Central African Republic to estimate the prevalence of HIV seropositivity in the general adult population in each province so that the public health authorities can target HIV prevention programmes to the priority areas. Blood samples were collected from women attending 48 antenatal clinics in urban and rural areas of the Central African Republic. These samples were tested for HIV antibodies in an anonymous and unlinked manner using strategy II recommended by WHO. The data were extrapolated to all women of reproductive age in Central African Republic by use of a parity-based adjustment involving the application of correction factors to the observed prevalence rates. A total of 9,305 pregnant women were recruited from November 2001 to October 2002. HIV seroprevalence was high in all age groups (12% in the less than 20 year age group to 17% in the 25-29 year age group). The median prevalence of HIV in antenatal clinics was similar for rural areas, for Bangui and for other urban areas (16.5, 15.0, and 12.5% respectively). Adjustment for parity and fertility pattern increased the prevalence of HIV in all antenatal clinics except in Bangui. This first national study of HIV prevalence in Central African Republic revealed that the HIV epidemic is continuing to spread in both urban and rural areas. Thus, efforts to reduce transmission should be made in every part of the country.     

CTLA-4 is required for the induction of high dose oral tolerance

Mucosal and systemic administrations of high dose antigens induce long- lasting peripheral T cell tolerance. We and others have shown that high dose peripheral T cell tolerance is mediated by anergy or deletion and is preceded by T cell activation. Co-stimulatory molecules B7-1 (CD80)/B7-2 (CD86) and their counter-receptors CD28/CTLA-4 play pivotal roles in T cell activation and immune regulation. In the present study, we examined the roles of the B7 co-stimulation pathway in the generation of high dose peripheral T cell tolerance. We found that blocking B7:CD28/CTLA-4 interaction at the time of tolerance induction partially prevented T cell tolerance, whereas selective blockade of B7:CTLA-4 interaction completely abrogated peripheral T cell tolerance induced by either oral or i.p. antigens. These results suggest that CTLA-4-mediated feedback regulation plays a crucial role in the induction of high dose peripheral T cell tolerance.      

Molecular genetic characterization of XRCC4 function

XRCC4 is a generally expressed protein of 334 amino acids that is involved in the repair of DNA double-strand breaks and in V(D)J recombination, but its function is unknown. In this study, we have used a mutational approach and the yeast two-hybrid method to perform an initial characterization of this protein. We show that the XRCC4 protein is located in the nucleus. We also demonstrate that several potential phosphorylation sites are not required for XRCC4 function in a transient V(D)J recombination assay. In addition, we show that XRCC4 forms a homodimer in vivo with the homodimerization domain being located within amino acids 115-204. Finally, we define a core domain of XRCC4 that functions in V(D)J recombination and comprises amino acids 18-204. Potential functions of XRCC4 are discussed.      

Immunohematological reference ranges for adult Ethiopians

A cross-sectional survey was carried out with 485 healthy working adult Ethiopians who are participating in a cohort study on the progression of human immunodeficiency virus type 1 (HIV-1) infection to establish hematological reference ranges for adult HIV-negative Ethiopians. In addition, enumeration of absolute numbers and percentages of leukocyte subsets was performed for 142 randomly selected HIV-negative individuals. Immunological results were compared to those of 1,356 healthy HIV-negative Dutch blood donor controls. Immunohematological mean values, medians, and 95th percentile reference ranges were established. Mean values were as follows: leukocyte (WBC) counts, 6.1 x 10(9)/liter (both genders); erythrocyte counts, 5.1 x 10(12)/liter (males) and 4.5 x 10(12)/liter (females); hemoglobin, 16.1 (male) and 14.3 (female) g/dl; hematocrit, 48.3% (male) and 42.0% (female); platelets, 205 x 10(9)/liter (both genders); monocytes, 343/microl; granulocytes, 3, 057/microl; lymphocytes, 1,857/microl; CD4 T cells, 775/microl; CD8 T cells, 747/microl; CD4/CD8 T-cell ratio, 1.2; T cells, 1, 555/microl; B cells, 191/microl; and NK cells, 250/microl. The major conclusions follow. (i) The WBC and platelet values of healthy HIV-negative Ethiopians are lower than the adopted reference values of Ethiopia. (ii) The absolute CD4 T-cell counts of healthy HIV-negative Ethiopians are considerably lower than those of the Dutch controls, while the opposite is true for the absolute CD8 T-cell counts. This results in a significantly reduced CD4/CD8 T-cell ratio for healthy Ethiopians, compared to the ratio for Dutch controls.     

Inhibition of experimental autoimmune encephalomyelitis in Lewis rats by nasal administration of encephalitogenic MBP peptides: synergistic effects of MBP 68-86 and 87-99

Induction of mucosal tolerance by inhalation of soluble peptides with defined T cell epitopes is receiving much attention as a means of specifically down-regulating pathogenic T cell reactivities in autoimmune and allergic disorders. Experimental autoimmune encephalomyelitis (EAE) induced in the Lewis rat by immunization with myelin basic protein (MBP) and Freund's adjuvant (CFA) is mediated by CD4+ T cells specific for the MBP amino acid sequences 68-86 and 87-99. To further define the principles of nasal tolerance induction, we generated three different MBP peptides (MBP 68-86, 87-99 and the non- encephalitogenic peptide 110-128), and evaluated whether their nasal administration on day -11, -10, -9, -8 and -7 prior to immunization with guinea pig MBP (gp-MBP) + CFA confers protection to Lewis rat EAE. Protection was achieved with the encephalitogenic peptides MBP 68-86 and 87-99, MBP 68-86 being more potent, but not with MBP 110-128. Neither MBP 68-86 nor 87-99 at doses used conferred complete protection to gp-MBP-induced EAE. In contrast, nasal administration of a mixture of MBP 68-86 and 87-99 completely blocked gp-MBP-induced EAE even at lower dosage compared to that being used for individual peptides. Rats tolerized with MBP 68-86 + 87-99 nasally showed decreased T cell responses to MBP reflected by lymphocyte proliferation and IFN-gamma ELISPOT assays. Rats tolerized with MBP 68-86 + 87-99 also had abrogated MBP-reactive IFN-gamma and tumor necrosis factor-alpha mRNA expression in lymph node cells compared to rats receiving MBP 110-128 nasally, while similar low levels of MBP-reactive transforming growth factor-beta and IL-4 mRNA expressing cells were observed in the two groups. Nasal administration of MBP 68-86 + 87-99 only slightly inhibited guinea pig spinal cord homogenate-induced EAE, and passive transfer of spleen mononuclear cells from MBP 68-86 + 87-99-tolerized rats did not protect naive rats from EAE. Finally, we show that nasal administration of MBP 68-86 + 87-99 can reverse ongoing EAE induced with gp-MBP, although higher doses are required compared to the dosage needed for prevention. In conclusion, nasal administration of encephalitogenic MBP peptides can induce antigen-specific T cell tolerance and confer incomplete protection to gp-MBP-induced EAE, and MBP 68-86 and 87-99 have synergistic effects. Non-regulatory mechanisms are proposed to be responsible for tolerance development after nasal peptide administration.      

恶性肿瘤患者血清与尿液中一氧化氮含量测定

0 引言一氧化氮（Nitric oxide,NO）是一种具有活跃生物化学性质的无机小分子. NO对许多肿瘤细胞和微生物有细胞毒性［1］,为探讨NO与肿瘤的关系,我们检测了119例恶性肿瘤患者血清及尿液中的NO.