Immediate hypersensitivity to Malassezia furfur and Candida albicans mannans in vivo and in vitro

BACKGROUND: Elevated and correlative Malassezia furfur (M. furfur) and Candida albicans (C. albicans) mannan-specific IgE have been demonstrated in atopic eczema dermatitis syndrome (AEDS) of the head, neck and shoulder (HNS) region of the skin. The significance of these antibodies in vivo has not been demonstrated. METHODS: Sixty-five AEDS patients with HNS distribution were included. Serum total IgE (S-IgE) and yeast antigen-specific (Cetavlon-purified mannan and whole extract antigens of M. furfur and C. albicans) IgE were measured and skin prick tests (SPT) were performed with the yeast antigens. RESULTS: Mannan-specific IgE and SPT were positive in 51 and 48% of patients with M. furfur and in 42 and 22% with C. albicans, respectively. Whole extract-specific IgE and SPT were positive in 85 and 95% of patients with M. furfur and in 91 and 57% with C. albicans, respectively. The highest correlation between specific IgE and SPT was seen with M. furfur mannan (r = 0.60; P < 0.0001). Both M. furfur mannan-specific IgE (r = 0.76; P < 0.0001) and SPT (r = 0.44; P = 0.0005) correlated with S-IgE. CONCLUSIONS: Mannan-induced immediate hypersensitivity in vivo was demonstrated in SPT. The significant correlation between M. furfur mannan-specific IgE and SPT suggests that mannan is an important allergen in yeast hypersensitive AEDS in vivo.     

Nosocomial vs. community-acquired infective endocarditis in Greece: changing epidemiological profile and mortality risk

Current epidemiological trends of infective endocarditis (IE) in Greece were investigated via a prospective cohort study of all cases of IE that fulfilled the Duke criteria during 2000-2004 in 14 tertiary and six general hospitals in the metropolitan area of Athens. Demographics, clinical data and outcome were compared for nosocomial IE (NIE) and community-acquired IE (CIE). NIE accounted for 42 (21.5%) and CIE for 153 (78.5%) of 195 cases. Intravenous drug use was associated exclusively with CIE, while co-morbidities (cardiovascular disease, diabetes mellitus, chronic renal failure requiring haemodialysis and malignancies) were more frequent in the NIE group (p <0.05). Prosthetic valve endocarditis (PVE) predominated in the NIE group (p 0.006), and >50% of NIE cases had a history of vascular intervention. Coagulase-negative staphylococci and enterococci were more frequent in cases of NIE than in cases of CIE (26.2% vs. 5.2%, p <0.01, and 30.9% vs. 16.3%, p 0.05, respectively). Enterococci accounted for 19.5% of total IE cases and were the leading cause of NIE. Staphylococcus aureus IE was hospital-acquired in only 11.9% of cases. In-hospital mortality was higher for NIE than for CIE (39.5% vs. 18.6%, p 0.02). Cardiac failure (New York Heart Association grade III-IV; OR 13.3, 95% CI 4.9-36.1, p <0.001) and prosthetic valve endocarditis (OR 3.7, 95% CI 1.3-10.6, p 0.01) were the most important predictors of mortality.     

A flow cytometric method for the measurement of phagocytosis by polymorphonuclear leucocytes

A new method for the measurement of phagocytosis of Candida albicans by human polymorphonuclear leucocytes (PMN) is described using a fluorescence activated cell sorter. We have used acridine orange to discriminate between PMN which have internalised yeast particles and those which have not. This method allows accurate measurement of particle phagocytosis as an event distinct from particle adherence. It also permits detailed examination of the kinetics of phagocytosis, the study of which is likely to be of value in the investigation of diseases where abnormalities of PMN function are suspected.     

The significance of blood cultures positive for emerging saprophytic moulds in cancer patients

The significance of blood cultures positive for emerging saprophytic moulds (e.g., Scedosporium apiospermum, Scedosporium prolificans, Paecilomyces spp.) was evaluated in 30 cancer patients (1996-2002). Diagnostic criteria proposed previously for evaluation of aspergillaemia were used. Blood cultures positive for emerging saprophytic moulds represented 1% of all positive fungal cultures. One case of catheter-related fungaemia was excluded. The remaining 29 cases consisted of true (n = 5), probable (n = 1), indeterminate (n = 7) fungaemia, and contamination (n = 16). True fungaemia was seen only in leukaemia patients and allogeneic bone marrow transplant recipients. S. apiospermum and S. prolificans were the commonest causes of true fungaemia.     

用PCR技术直接检测白色念珠菌DNA的实验研究

目的建立和评价直接用PCR从血标本中检测白色念珠菌核酸的方法。方法用红、白细胞裂解液、破壁酶和真菌DNA提取盒直接处理血标本,得到的微量靶DNA用白色念珠菌种特异性引物进行扩增。结果在白色念珠菌制备的人血标本中检测出靶DNA,其敏感性达10个孢子/ml以下,从处理标本到报告结果仅需6h。结论用PCR法可特异、敏感地从血标本中直接检测白色念珠菌核酸,有助于临床快速诊断深部白色念珠菌感染。     

玉米浆用量、渗透压和耗糖速率对甘油发酵的影响

Candida krusei发酵生产甘油过程中,菌体生长由玉米浆限制,菌体对玉米浆的得率为1．63g/g,培养其中玉米浆浓度相同时,增加渗透压或通过流加补料限制生长阶段的菌体生长,可使甘油生产阶段的比耗糖速率减慢,比耗糖速率保持在不很高的水平,可以因消耗的葡萄糖用于生长,维持,甘油和副产物形成所占比例的变化而提高甘油得率。     

Histamine release from basophil leukocytes induced by microbial antigen preparations in patients with AIDS

Type I allergy against some common microorganisms was investigated in 14 patients with AIDS and 11 human immunodeficiency virus (HIV) antibody-positive homosexual men, and in a control group consisting of 13 heterosexual men without HIV antibodies. Basophil histamine release technique was used as a sensitive method to detect type I allergy against Candida albicans (CA), Herpes simplex virus type I (HSV-I) and cytomegalovirus (CMV). Of the 14 AIDS patients 11 (78%) showed significant histamine release when stimulated with CA, and HSV-I caused release in 10 (71%), whereas no response was obtained by CMV. In the group of HIV antibody-positive men only one released histamine when stimulated with CA and HSV-I and this patient also had lymphadenopathia. In contrast to these results, no release of histamine was obtained in the control group consisting of 13 heterosexual men. The histamine release caused by CA and HSV-I is mediated by an immunological reaction, since the release was abolished and regained by removal from and refixation to the cell surface of the cell-bound immunoglobulins. These results suggest an involvement of type I allergy as a pathogenetic co-factor in some infections in AIDS, and allergic type I reactions to CA and HSV-I might be an indicator for the presence of manifest AIDS.     

Epidemiological study of pathogenic fungi in China: 1986 and 1996

目的　研究 1986年 - 1996年 ,我国致病真菌菌群的变化情况。方法　 1986年 1月 1日 - 12月 31日和 1996年 1月 1日 - 12月 31日在全国 2 5个省、市、自治区 4 0多个有代表性的单位对临床或现场确定的致病菌进行了动态研究 ,就病原菌变迁、各区动态情况和具体疾病等作了详细分析。结果　发现 10年间较易治疗的皮肤癣菌比例下降 ,而较难治疗的酵母菌和霉菌比例升高。结论　 10年间致病真菌菌群的变化较大 ,我们应根据变化情况进行相应的研究及制定出相应治疗措施     

83例住院患者念珠菌感染的菌株鉴定及药敏分析

目的 :探讨住院患者念珠菌感染的种类及耐药现状。方法 :用法国生物 -梅里埃公司酵母菌鉴定系统和药敏试纸条进行菌株鉴定和药敏试验。结果 :白色念珠菌检出率最高 (5 0 .6 0 % ) ,热带念珠菌次之 (2 6 .5 1% ) ,高里氏念珠菌、近平滑念珠菌、分别为 9.6 4%和 7.2 3% ,其它念珠菌均在 5 .0 %以下。 6种抗真菌药中 ,5 -氟胞嘧啶、两性霉素B、制霉菌素的耐药率最低 (1.2 0 % ) ,唑类抗真菌的耐药率最高 (8.43～ 18.0 7% )。结论 :结果提示临床医师治疗真菌感染时应先进行培养和药敏试验 ,以便合理治疗 ,预防医院内感染。     

Clonal composition and persistence of antigen-specific circulating T follicular helper cells

T follicular helper (T_FH) cells play an essential role in promoting B cell responses and antibody affinity maturation in germinal centers (GC). A subset of memory CD4⁺ T cells expressing the chemokine receptor CXCR5 has been described in human blood as phenotypically and clonally related to GC T_FH cells. However, the antigen specificity and relationship of these circulating T_FH (cT_FH) cells with other memory CD4⁺ T cells remain poorly defined. Combining antigenic stimulation and T cell receptor (TCR) Vβ sequencing, we found T cells specific to tetanus toxoid (TT), influenza vaccine (Flu), or Candida albicans (C.alb) in both cT_FH and non-cT_FH subsets, although with different frequencies and effector functions. Interestingly, cT_FH and non-cT_FH cells specific for C.alb or TT had a largely overlapping TCR Vβ repertoire while the repertoire of Flu-specific cT_FH and non-cT_FH cells was distinct. Furthermore, Flu-specific but not C.alb-specific PD-1⁺ cT_FH cells had a “GC T_FH-like” phenotype, with overexpression of IL21, CXCL13, and BCL6. Longitudinal analysis of serial blood donations showed that Flu-specific cT_FH and non-cT_FH cells persisted as stable repertoires for years. Collectively, our study provides insights on the relationship of cT_FH with non-cT_FH cells and on the heterogeneity and persistence of antigen-specific human cT_FH cells.