The unmasking of <Emphasis Type="Italic">Pneumocystis jiroveci</Emphasis> pneumonia during reversal of immunosuppression: case reports and literature review

Background  

Pneumocystis jiroveci pneumonia (PCP) is an important opportunistic infection among immunosuppressed patients, especially in those infected with human immunodeficiency virus (HIV). The clinical presentation of PCP in immunosuppressed patients have been well-reported in the literature. However, the clinical importance of PCP manifesting in the setting of an immunorestitution disease (IRD), defined as an acute symptomatic or paradoxical deterioration of a (presumably) preexisting infection, which is temporally related to the recovery of the immune system and is due to immunopathological damage associated with the reversal of immunosuppressive processes, has received relatively little attention until recently.     

The effect of fibrin polymers on thrombin-catalyzed plasma factor XIIIa formation

The effect of fibrin polymers on thrombin-catalyzed factor XIIIa formation was studied in afibrinogenemic plasma. Fibrin polymers derived from des A fibrinogen and des A,B fibrinogen increased sixfold the rate of thrombin-catalyzed factor XIIIa formation in the presence of EDTA. Calcium chloride accelerated factor XIIIa formation 14-fold in the presence of des A,B fibrinogen without increasing the rate of thrombin formation. Fibrinopeptides A and B had no effect on factor XIIIa formation in afibrinogenemic plasma. Des A,B fibrinogen reduced by 20- to 40-fold the thrombin concentration required to activate factor XIII. Glycyl-L-prolyl-L-arginyl-L-proline (gly-pro-arg-pro), a fibrin polymerization inhibitor, inhibited des A and des A,B fibrinogen from enhancing thrombin-catalyzed factor XIIIa formation. Gly-pro-arg- pro did not modify factor XIIIa formation in afibrinogenemic plasma and did not inhibit thrombin cleavage of the chromogenic substrate S-2238. These results demonstrate that fibrin polymers accelerate thrombin- catalyzed plasma factor XIIIa formation.     

AP-1和肿瘤的关系研究进展

转录因子AP-1(activatorprotein1),主要由Jun、Fos、ATF及JDP亚家族组成,亚家族单体以同源或异源二聚体的形式结合DNA靶序列,参与靶基因调节.对基因修饰小鼠和细胞的研究表明,AP-1参与细胞的正常生长和癌性转化过程,其在细胞中的作用取决于细胞类型、AP-1的组成和各组分的相对比例,也与刺激的种类密切相关.AP-1的活性受多种核因子调节,同时单体间也存在相互促进或拮抗作用.AP-1对各种刺激如应激、辐射或生长信号等作出生理或病理应答,参与细胞的增殖、分化和转化等过程,在肿瘤的形成、转移和侵袭中发挥重要作用,已经有学者研究通过抑制AP-1活性来发展抗肿瘤药物.     

Comparison of clinical and self-reported diagnoses for participants on a community-based arthritis self-management programme

OBJECTIVE: With the advent of community-based arthritis education programmes, it is important to determine the accuracy of participants' self-reported diagnoses. The purpose of this study was to determine the level of agreement between general practitioner (GP)-recorded and self- reported diagnoses of participants attending an Arthritis Self- Management Programme (ASMP). METHODS: Participants enrolling on the ASMP were asked to (a) identify their type of arthritis via a self- administered postal questionnaire and (b) obtain a written confirmation of their diagnosis from their GP. The sample (n = 613) comprised mainly women (83%) with a mean age of 58.8 yr (S.D. 12.6) and a mean disease duration of 15.4 yr (S.D. 12.5). RESULTS: Participants' self-reported diagnoses were confirmed by GPs in 534 cases [87.1%, 95% confidence interval (CI): 84.4 89.8%]. Confirmed diagnoses were reported by 86.9% (95% CI: 83.1-90.7%) of those with osteoarthritis (OA) and 96.1% (95% CI: 93.6 98.6%) of those with rheumatoid arthritis (RA). The concordance rate for all other types of arthritis combined was lower at 60.5% (95% CI: 49.5-71.5%). There were no significant differences with respect to age, gender, education, physical functioning, duration of disease and number of GP visits between those who correctly identified their type of arthritis and those who did not. CONCLUSIONS: This study suggests that the majority of RA and OA participants attending an arthritis education programme can correctly identify their specific type of arthritis.      

The functional characterization of interleukin-10 receptor expression on human natural killer cells

Human natural killer (NK) cells are large granular lymphocytes that constitutively express functional forms of the interleukin-2 receptor (IL-2R) and lyse tumor and virally infected cells without prior sensitization. NK cells with high density expression of CD56 (CD56bright) express the high affinity IL-2R and proliferate in response to low (picomolar) concentrations of IL-2. CD56dim NK cells express the intermediate affinity IL-2R and demonstrate enhanced cytotoxic activity without proliferation in response to high (nanomolar) concentrations of IL-2. In the present study, we characterized IL-10R expression on human NK cells and the functional consequences of IL-10 binding directly to highly purified subsets of CD56bright and CD56dim NK cells. Binding studies using 125I-IL-10 indicated that resting human NK cells constitutively express the IL-10 receptor protein at a surface density of approximately 90 receptor sites per cell, with a kd of approximately 1 nmol/L. Alone, IL-10 did not induce proliferation of CD56bright or CD56dim NK cell subsets. However, at low concentrations (0.5 to 5 ng/mL), IL-10 significantly augmented IL-2-induced proliferation of the CD56bright NK cell subset mediated via the high-affinity IL-2R. In the absence of IL-2, IL-10 was able to induce significant NK cytotoxic activity against NK-resistant tumor cell targets in both subsets of NK cells in a dose-dependent fashion. Furthermore, the combination of IL-10 and IL-2 had an additive effect on NK cytotoxic activity, whereas that of IL-10 and IL-12 did not. Production of interferon-gamma, tumor necrosis factor-alpha, and granulocyte-macrophage colony-stimulating factor by IL-2-activated NK cells was also significantly enhanced by IL-10. Neither resting nor activated human NK cells appear to produce human IL-10 protein. In summary, NK cells constitutively express the IL-10R protein in low density, and the functional consequences of IL-10 binding directly to human NK cell subsets appear to be stimulatory and dose-dependent. In contrast to its direct effects on human T cells and monocytes/macrophages, IL-10 potentiates cytokine production by human NK cells.     

The CTLA-4 gene region of chromosome 2q33 is linked to, and associated with, type 1 diabetes. Belgian Diabetes Registry

Susceptibility to autoimmune insulin-dependent (type 1) diabetes mellitus is determined by a combination of environmental and genetic factors, which include variation in MHC genes on chromosome 6p21 (IDDM1) and the insulin gene on chromosome 11p15 (IDDM2). However, linkage to IDDM1 and IDDM2 cannot explain the clustering of type 1 diabetes in families, and a role for other genes is inferred. In the present report we describe linkage and association of type 1 diabetes to the CTLA-4 gene (cytotoxic T lymphocyte associated-4) on chromosome 2q33 (designated IDDM12). CTLA-4 is a strong candidate gene for T cell- mediated autoimmune disease because it encodes a T cell receptor that mediates T cell apoptosis and is a vital negative regulator of T cell activation. In addition, we provide supporting evidence that CTLA-4 is associated with susceptibility to Graves' disease, another organ- specific autoimmune disease.      

Rising incidence of type 1 diabetes in Scottish children, 1984-93. The Scottish Study Group for the Care of Young Diabetics

OBJECTIVES: To calculate the incidence of type 1 diabetes in Scottish children aged less than 15 years between 1984 and 1993; to examine changes in incidence; and to calculate the prevalence of diabetes at the end of this period. DESIGN: Three data sources were used to construct the Scottish Study Group for the Care of Young Diabetics register: active reporting of all new cases; reports from the Scottish Morbidity Register 1; and local registers. SUBJECTS: All children resident in Scotland diagnosed with primary insulin dependent diabetes mellitus when less than 15 years of age between 1984 and 1993. MAIN OUTCOME MEASURES: Annual incidence and prevalence rate for Scotland; time trend in incidence over the 10 years; differences in incidence between the three different age groups; and completeness of the register. RESULTS: The average annual incidence for Scotland was 23.9/100,000 children. The prevalence rate was 1.5/1000 in 1993. A total of 2326 cases was identified from the three sources. Capture-recapture analysis suggests a case ascertainment of 98.6%. The annual incidence rates increased at a rate of 2% each year (rate ratio = 1.02, 95% confidence interval (CI) 1.01 to 1.03). The incidence was higher in boys than girls (rate ratio = 1.08, 95% CI 1.00 to 1.18), and the incidence rates increased with age: 15.3/100,000/year for age 0-4 years, 24.4/ 100,000/year for age 5-9 years, and 31.9/ 100,000/year for age 10-14 years. CONCLUSIONS: The incidence of type 1 diabetes in Scotland is increasing and the prevalence is relatively high. These findings have important implications for health service resource allocation. The Scottish Study Group for the Care of Young Diabetics' register provides a base for monitoring and research.