Detection of antibodies specific to an antigenic cell wall galactomannoprotein for serodiagnosis of Aspergillus fumigatus aspergillosis

Aspergilloma and invasive aspergillosis are important opportunistic infections caused by Aspergillus species, among which Aspergillus fumigatus is the most common species associated with human disease. We developed an enzyme-linked immunosorbent assay (ELISA)-based antibody assay with Afmp1p, a purified recombinant antigenic cell wall galactomannoprotein of A. fumigatus. Evaluation of the test with guinea pig sera against A. fumigatus and other pathogenic fungi indicated that this assay was specific for A. fumigatus. Clinical evaluation revealed that the assay was 100% sensitive for patients with aspergilloma and 33.3% sensitive for patients with invasive aspergillosis. No false-positive results were found for serum samples from 80 healthy blood donors, 6 patients with typhoid fever, 4 patients with melioidosis, 20 patients with penicilliosis marneffei, 5 patients with candidiasis, and 4 patients with cryptococcosis, indicating a high specificity of the test. Thus, this ELISA-based test for the detection of anti-Afmp1p antibody can be of significant value as a diagnostic for aspergillosis.     

Systemic autoimmune disease induced by dendritic cells that have captured necrotic but not apoptotic cells in susceptible mouse strains

Systemic lupus erythematosus (SLE) is an autoimmune disorder of a largely unknown etiology. Anti-double-stranded (ds) DNA antibodies are a classic hallmark of the disease, although the mechanism underlying their induction remains unclear. We demonstrate here that, in both lupus-prone and normal mouse strains, strong anti-dsDNA antibody responses can be induced by dendritic cells (DC) that have ingested syngeneic necrotic (DC/nec), but not apoptotic (DC/apo), cells. Clinical manifestations of lupus were evident, however, only in susceptible mouse strains, which correlate with the ability of DC/nec to release IFN-gamma and to induce the pathogenic IgG2a anti-dsDNA antibodies. Injection of DC/nec not only accelerated disease progression in the MRL/MpJ-lpr/lpr lupus-prone mice but also induced a lupus-like disease in the MRL/MpJ-+/+ wild-type control strain. Immune complex deposition was readily detectable in the kidneys, and the mice developed proteinuria. Strikingly, female MRL/MpJ-+/+ mice that had received DC/nec, but not DC/apo, developed a 'butterfly' facial lesion resembling a cardinal feature of human SLE. Our study therefore demonstrates that DC/nec inducing a Th1 type of responses, which are otherwise tightly regulated in a normal immune system, may play a pivotal role in SLE pathogenesis.     

Evaluation of a Selective Transport Medium for Gastric Biopsy Specimens To Be Cultured for Helicobacter pylori

Since the means of culturing Helicobacter pylori may not be available in some laboratories, prolonging the survival of this organism during transportation is a major concern in terms of improving detection rates. A selective transport medium was evaluated for the preservation of H. pylori from 254 gastric biopsy specimens collected from a rural area in China where culturing is not feasible. Gastric biopsy specimens were inoculated in sterile broth consisting of brain heart infusion (BHI) broth, horse serum, and yeast extract supplemented with vancomycin, amphotericin B, and nalidixic acid (VAN). Of the 254 biopsy specimens, 238 were identified by histology to have H. pylori infection. Total rates of recovery of H. pylori from the H. pylori-positive gastric biopsy specimens stored in the BHI-VAN broth ranged from 76 to 46% after storage of specimens for 5 to 9 days. In conclusion, the selective medium is useful for prolonging the survival of H. pylori in gastric biopsy specimens for which immediate culture is not feasible.     

Studies in the enhancement of tumour immunity by coupling strong antigens to tumour cells (''heterogenization of tumours''). Helper T cell clones against PPD help other T cells mount anti-tumour responses to PPD-coupled tumour cells

PPD-reactive T cell clones have been used to analyse the nature of T lymphocytes that are involved in the 'heterogenization' of tumour cells. This is a phenomenon where coupling tumour cells to a strong antigen (in this case PPD) causes an enhanced immune response to tumour-specific antigens to be elicited providing that the host shows T cell immunity to the strong antigen (in this case is BCG positive). Clones of T cells with the Lyt1+2- phenotype which were unable to mediate delayed-type hypersensitivity but which provided efficient help to hapten-primed B cells were found to potentiate anti-tumour immunity in BCG-negative syngeneic mice when immunized with Con-A-PPD coupled, X-irradiated MC6A tumour cells. There therefore appears to be a mechanism whereby a helper T cell response to one antigen can provide help for the generation of a T cell response to a linked antigen which is analogous to the well-known phenomenon of help to hapten primed B cells. Furthermore the clones of T cells that help B cells the best are those that give maximal augmentation of T cell immunity.     

Cytopathic effects of Treponema denticola chymotrypsin-like proteinase on migrating and stratified epithelial cells.

The effects of Treponema denticola and its outer membrane-bound chymotrypsin-like proteinase on periodontal ligament epithelial cell cultures at different stages of maturity were studied. In sparse cultures with migrating epithelial cells, large intracellular vacuoles were formed rapidly following exposure to live T. denticola. Treponemes showing structural damage were seen occasionally inside membrane-bound vesicles. Intensive membrane blebbing occurred in infected cells and continued for up to 48 h before the cell died. Blebbing could also be induced by a purified chymotrypsin-like proteinase of T. denticola. Cortical actin and alpha-actinin of the bacterium-treated cells showed disorganization, and pericellular fibronectin was degraded by both whole T. denticola and the isolated proteinase. Epithelial cells with well-formed lateral cell contacts appeared to be more resistant to the effects of T. denticola than migrating isolated cells. In multilayer epithelial cultures, adhesion of T. denticola and membrane blebbing were observed infrequently. There was no evidence of invasion of T. denticola into epithelial multilayers. However, immunogold electron microscopy showed rapid transport of T. denticola chymotrypsin-like proteinase into newly formed large intracellular vacuoles within the epithelial layers. These vacuoles were lined by membranes studded with ribosomes. T. denticola-treated epithelial multilayers had loose cell contacts, collapsed intercellular spaces, and increased permeability. Through its capacity to cause these unique cytopathic effects, the chymotrypsin-like proteinase of T. denticola has the potential to contribute to the initiation of periodontal disease.     

Skin Cancer Risk Associated with Immunosuppressive Therapy in Organ Transplant Recipients

The aim of this review is to summarise the available literature regarding the epidemiology and proposed mechanisms of skin cancer development in organ transplant recipients who are receiving lifelong treatment with immunosuppressive therapy and to review the different strategies for managing complications in this group of patients. Organ transplantation is complicated by an increased incidence of certain cancers, of which non-Hodgkin's lymphoma, Kaposi's sarcoma and squamous cell carcinoma are the most common. The most important risk factor for these cancers is immunosuppressive therapy. The relative importance of different immunosuppressive therapy regimens in relation to the development of skin cancer is still unclear. Immunosuppression per se may play the most important role, but other mechanisms, which are independent of host immunity and which may be different for the various agents used, may also be of importance for the increased risk of cancer. Apart from immunosuppressive therapy, exposure to sunlight and infection with human papillomaviruses are believed to be the most important risk factors for the development of cutaneous squamous cell carcinoma in organ transplant recipients. Human papillomaviruses, no doubt, benefit considerably from immunosuppression, as is indicated by the large number of warts found in these patients, but many questions remain unanswered about their significance in cutaneous oncogenesis. The E6 protein from a range of cutaneous human papillomavirus types effectively inhibits apoptosis in response to ultraviolet light damage. It is, therefore, conceivable that the development of skin cancer in organ transplant recipients is the result of a complex interplay between exposure to ultraviolet radiation, human papillomavirus infection and genetic predisposition. Measures for protection from the sun are important for reducing the risk of skin cancer in organ transplant recipients. Regular surveillance of patients with skin problems and easy access to a dermatologist for these patients is advised. Changing the immunosuppressive regimen from azathioprine to cyclosporin or vice versa does not seem to relieve the skin problems. Tapering the immunosuppressive therapy to the lowest possible dose may be of some advantage. Oral retinoids, e.g. acitretin, have some effect in reducing the number of keratotic skin lesions and in the prevention of skin cancer in organ transplant recipients. Resurfacing the back of the hand can be a successful treatment for patients with multiple skin cancers on the back of the hand and can be used prophylactically in patients with severely actinically damaged skin.     

Immunohistochemical and ultrastructural correlates of muscle-actin expression in pleomorphic adenomas and myoepitheliomas based on comparison of formalin and methanol fixation

Summary The degree and range of differentiation of the cells referred to as myoepithelial-like in pleomorphic adenomas and the tumour cells of myoepitheliomas are not definitely established. This type of information is critical for establishing reliable diagnostic criteria, such as expression of muscle-specific actin and ultrastructural identification of myofilaments, in these and other salivary gland tumours. Pleomorphic adenomas (18) and myoepitheliomas (5), of which 10 cases were fixed only in formalin and 13 cases where tissues were fixed in both formalin and methanol/acetic acid, were studied. Each tumour and normal accompanying parotid was immunostained with two monoclonal antibodies for smooth muscle actin, HHF35 and MSA. Staining of myoepithelial cells was absent in certain samples of normal gland with both HHF35 (15%) and MSA (69%) when formalin-fixed tissue was used. Using formalin-fixed tissue from 15 pleomorphic adenomas/myoepitheliomas, 2 (14%) had focal positivity with HHF35, while 8 cases (57%) were positive with MSA. However, a certain degree of false positivity was suspected since in samples of normal parotid, both acinar and duct cells were frequently stained, particularly with MSA. With methanol/ acetic acid-fixed tissue only 4 of 13 cases (31%) were positive with either MSA or HHF35 and 2 of these only had a minor proportion of the tumour cells expressing muscle-specific actin. Using alcohol-fixed tissue, myoepithelial cells were strongly stained in all examples of normal parotid gland with both anti-actin antibodies. In 5 cases examined by electron microscopy, there was no apparent correlation between immunohistochemical results and the presence or absence of cytoplasmic filament accumulation. The results indicate considerable tumour cell heterogeneity in muscle-specific actin expression and suggest that non-luminal cells in pleomorphic adenomas and the tumour cells in myoepitheliomas may differentiate as classical myoepithelial cells, as partially differentiated (i.e. modified myoepithelial cells) or as the counterpart of basal cells present in the intra- and interlobular ducts of normal salivary gland.     

肝素酶和碱性成纤维细胞生长因子与非小细胞肺癌转移和预后的关系

目的 探讨肝素酶(heparanase)和碱性成纤维细胞生长因子(bFGF)在人非小细胞肺癌(NSCLC)组织中表达的临床意义及其与肺癌转移和预后的关系。方法 采用免疫组织化学、原位杂交和Western blot方法,检测115例人NSCLC石蜡切片和45例新鲜肺癌及对应癌旁正常组织中肝素酶和bFGF的表达情况。采用χ^2检验、t检验、生存曲线和Cox比例风险回归等方法分析肝素酶和bFGF分别表达及共表达的意义。结果 免疫组织化学染色证实肝素酶(91／115)和bFGF(89／115)主要表达在癌细胞质和(或)细胞膜中,在正常肺泡上皮和支气管上皮中则呈阴性表达。Western blot也证实肝素酶在肺癌中的表达明显增高(P=0．041)。统计分析结果显示：肝素酶和bFGF的表达具有明显的一致性(P：0．0001),二者单独表达和共表达均与肺癌的分期、血管侵袭、淋巴结转移、微血管密度和预后有关,其中,二者共表达时与分期和微血管密度的相关性更显著;另外,bFGF还与肺癌的分化程度有关。多因素分析结果显示,肺癌的分化程度、血管浸润、淋巴结转移和bFGF的表达可以作为判断肺癌预后的危险因素,但肝素酶不是影响预后的独立因素。结论 肝素酶和bFGF均与肺癌的转移、血管生成和预后密切相关。     

Systemic oxidative and antioxidative status in Chinese patients with asthma

BACKGROUND: Patients with asthma generate an increased amount of reactive oxygen species from peripheral blood cells. Reactive oxygen species produce many of the pathophysiologic changes associated with asthma and may contribute to its pathogenesis. OBJECTIVE: We investigated changes in antioxidant enzyme activities and oxidized glutathione (glutathione disulfide; GSSG) levels in erythrocytes from a group of healthy control Chinese subjects (n=135) and patients with asthma (n=106). METHODS: Baseline pulmonary function was measured for all subjects. Antioxidant status was evaluated by measuring erythrocyte superoxide dismutase, catalase, and glutathione peroxidase activities. Oxidative stress was also measured in terms of GSSG in erythrocytes with a kinetic microassay. RESULTS: Patients with asthma had significantly increased erythrocyte superoxide dismutase and catalase activities compared with controls (61.10 +/- 1.30 U/g hemoglobin [Hb] vs 55.51 +/- 1.82 U/g Hb [P=.018] and 0.0637 +/- 0.0021 U/g Hb vs 0.0257 +/- 0.0120 U/g Hb [P <.001] for the asthma and control groups, respectively). Conversely, erythrocyte glutathione peroxidase activity decreased (44.21 +/- 1.33 mU/g Hb vs 50.07 +/- 1.39 mU/g Hb for the asthma and control groups, respectively; P=.003). Patients with asthma also had significantly higher GSSG levels in erythrocyte hemolysates compared with controls (167.40 +/- 2.93 micromol/L vs 44.98 +/- 0.44 micromol/L for the asthma and control groups, respectively; P <.001), indicating increased oxidative stress. CONCLUSIONS: Asthma is accompanied by an alteration in systemic antioxidant status due to possible oxidative stress in this disease.     

Synergistic effect of IL-4 and TNF-alpha in the induction of monocytic differentiation of a mouse myeloid leukaemic cell line (WEHI-3B JCS).

We have previously shown that non-cytotoxic concentrations (600-1200 U/ml) of recombinant mouse tumour necrosis factor-alpha (TNF-alpha) can induce differentiation of a subclone (JCS) of the WEHI-3B myelomonocytic leukaemia cell line into mature cells with the characteristics of macrophages. In the present study, the effects of recombinant mouse interleukin-4 (IL-4), either alone or in combination with mouse TNF-alpha, on the growth and differentiation of JCS cells were examined. IL-4 alone (20-5000 U/ml) inhibited the growth of JCS cells in a dose-dependent manner but did not induce cell differentiation. However, combinations of IL-4 and TNF-alpha acted in synergy to inhibit cell proliferation and induce monocytic differentiation of JCS cells, as shown by increased expression of the macrophage differentiation antigens (F4/80, Mac-1), stimulation of phagocytic activity, induction of non-specific esterase and NBT-reducing activities, increased plastic adherence and morphological criteria. Similar synergistic interactions were also shown by human TNF-alpha and mouse IL-4, indicating that TNF-alpha might exert its effects through the low-affinity (p55) TNF receptors. Moreover, the clonogenicity of JCS cells in vitro and their tumorigenicity in vivo were significantly reduced by combined TNF-alpha and IL-4 treatment. Our results indicate that TNF-alpha can act as a differential signal for JCS cells and that its effects are modulated by IL-4. Therefore, the combination of TNF-alpha and IL-4 may be useful in the treatment of some forms of myelomonocytic leukaemia.