Predominance of antibodies to hepatitis C virus envelope proteins in various disease statuses of hepatitis C

The antibody profile to various proteins of hepatitis C virus (HCV) was studied in 113 patients positive for HCV RNA in various disease statuses of hepatitis C (HC). A single peptide (E2/NS1, aa 413-436 of HCV polyprotein) chosen from a conserved region at the C-terminus of the hypervariable region (HVR) HVR1 of HCV was found to be sufficient for reliable diagnosis of the infection, even in the acute phase. Six hundred and one suspected HC cases and 200 voluntary blood donors were tested by this peptide. The sensitivity of detection of HCV antibodies by this peptide did not increase with addition of peptides from other HCV proteins. Our results clearly demonstrate that antibodies to HCV envelope proteins occur in a higher percentage of the infected population than those to other proteins. This emphasizes the necessity of using representative sequences from HCV envelope proteins in diagnostic immunoassays of this viral infection.     

Alteration in platelet count during early pregnancy in the mouse

Published reports of pregnancy associated thrombocytopenia in mice have utilized the Quackenbush strain. The inability of some laboratories to verify this observation in other mouse strains prompted us to report our findings by using Swiss Albino ICR mice. In Exp. 1, pregnant and pseudopregnant mice were bled prior to mating (time 0) and daily on day 1 (vaginal plug) through day 7. In Exp. 2, media from 24 hr cultures of 2-cell mouse embryos or media from unfertilized oocytes were injected into splenectomized mice. Animals were bled at time 0 (before injection) and at 30, 60, and 120 min after injection. In Exp. 3, splenectomized mice were treated with either media from 2-cell stage embryos or with media supplemented with synthetic platelet-activating factor (PAF: 0.05, 0.1 or 0.2 micrograms). Animals were bled as in Exp. 2. Platelet numbers were determined in duplicate from each blood sample by using a hemacytometer. In Exp. 4, antagonist (SRI 63-441) or vehicle was administered to mated mice on days 1 through 4 of pregnancy. Animals were examined on day 8 to determine number of developing conceptuses. In Exp. 1-3, data were analyzed by using ANOVA for repeated measures, and in Exp. 4 data were analyzed by chi-square analysis. In Exp. 1, there was a treatment x time interaction (P less than .06) due to transient thrombocytopenia in pregnant but not pseudopregnant mice.(ABSTRACT TRUNCATED AT 250 WORDS)     

Establishment of a human hepatocellular carcinoma cell line releasing hepatitis B virus surface antigen

A new hepatocellular carcinoma cell line, DELSH-5, derived from operative wedge biospy from a HBsAg sero- and tissue-positive patient, has been continuously propagated in vitro for nearly 22 months. The cells not only resemble hepatocytes on light and electron microscopic examination but also possess biosynthetic markers of the latter such as albumin and alpha-foetoprotein which were demonstrated in the supernatant medium as well as in the tumour cell cytoplasm. Karyology of cloned cells shows moderate aneuploidy, the major model chromosome number being 61. Though in the initial few passages HBsAg could not be detected, from the 13th passage onwards this viral component could be consistently demonstrated in small amounts in the concentrated supernatant medium by the macro- and micro-ELISA techniques. The immunohistochemical techniques as well as electron microscopy have failed to demonstrate any virus component inside the cell. The cell line reported here is the third of its kind which will act as a useful laboratory model to obtain pure HBsAg and to study the hepatitis-B-virus--liver-cell interaction with particular reference to the oncogenic potential of the virus.     

Cytopathology of uncommon malignant renal neoplasms in the pediatric age group

Malignant renal neoplasms are common solid tumors in pediatric oncology practice. These include the common Wilms' tumor/nephroblastoma and the uncommon neoplasms such as clear-cell sarcoma of the kidney (CCSK), rhabdoid tumor, renal-cell carcinoma, and others. The aim of this study was to describe in detail the cytopathological features of the histopathologically proven uncommon pediatric renal tumors. Aspirates from Wilms' tumor, which are mesenchyme predominant, show clusters of spindle cells associated with the matrix material. Evidence of rhabdomyoblastic differentiation may be present. CCSK, classic subtype, is characterized by round to oval cells arranged perivascularly and also in sheets and clusters intimately associated with a metachromatic matrix mucopolysaccharide material better appreciated in May-Grunwald-Giemsa (MGG)-stained smears. The cells also have more abundant cytoplasm and may show nuclear grooves. Spindle-cell pattern of CCSK is difficult to diagnose on aspiration cytology. Renal-cell carcinoma of childhood shows similar cytological features as its adult counterpart. Rhabdoid tumor of the kidney is characterized by a monomorphic population of cells with abundant cytoplasm, eccentric nuclei with prominent nucleoli. Intrarenal yolk sac tumor is a rare neoplasm and shows severely pleomorphic cells on aspiration.Awareness of these entities is important for the practicing cytopathologist. Further, non-Wilms' renal malignant neoplasms must be distinguished from the common Wilms' tumor so that appropriate chemotherapy protocols may be instituted in cases where the tumor is in an advanced stage of malignancy.     

从卵巢癌cDNA文库中筛选新的肿瘤标志物

采用SEREX法筛选了自行构建的中国人卵巢癌cDNA表达文库 ,得到 2 7个阳性克隆 ,其中 3个为全长cDNA。序列分析和同源性比对结果表明所获得的 2 7个克隆分属于分化抗原、细胞结构蛋白及功能未知三类。选择其中一个全长cDNAMY OVA 13(该基因编码的蛋白是MAD2 ) ,利用基因工程方法克隆、表达和纯化得到目的蛋白 ,采用点杂交方法检测了MY OVA 13目的蛋白与正常人和肿瘤患者中的血清学反应。MY OVA 13抗体只在肿瘤组中检测到 (5 / 74 ) ,在正常组中均为阴性 ;间接ELISA测定结果显示 ,MY OVA 13抗体的水平在肿瘤组中均高于正常组 ,其中肝癌和前列腺癌组与正常组相比 ,在统计学上有显著差异 ,P值分别 <0 0 1和 <0 0 5。我们的初步结果表明MY OVA 13及其抗体具有一定的肿瘤特异性 ,有可能作为肿瘤诊断的标志物     

Oxidant-mediated activation of cytosolic phospholipase a(2) in pulmonary endothelium: role of protein kinase C alpha and a pertussis toxin-sensitive protein.

The authors have previously demonstrated that the oxidant t-buOOH stimulates phospholipase A(2) (PLA(2)) activity in bovine pulmonary artery endothelial cells (S. Chakraborti et al. American Journal of Physiology, 257, L430-L437, 1989). Herein, the authors sought to investigate the mechanism by which t-buOOH stimulates PLA(2) activity and the role of protein kinase C (PKC) in this scenario. Treatment of bovine pulmonary artery endothelial cells with t-buOOH stimulated an aprotinin-sensitive protease activity, PKC activity, and PLA(2) activity in the cell membrane. Pretreatment with intracellular Ca(2+) chelator (BAPTA-AM), PKCalpha inhibitor (Go6976), cPLA(2) inhibitor (AACOCF(3)), and pertussis toxin prevented t-buOOH-stimulated PLA(2) activity. Immunoblot studies with aprotinin, cPLA(2), PKCalpha, and Gialpha antibodies revealed their presence in the endothelial membrane. Immunoblot studies of the cell membrane isolated from t-buOOH-stimulated cells with cPLA(2) and PKCalpha antibodies elicited an apparent increase in their immunoreactive protein profiles along with an additional 47-kDa immunoreactive fragment in the membrane. t-buOOH caused Gialpha phosphorylation in the membrane and pretreatment with Go6976 prevented the phosphorylation. Overall, these results suggest that t-buOOH stimulates an aprotinin-sensitive protease activity that proteolytically activates PKCalpha and that subsequently phosphorylates a pertussis toxin-sensitive protein, resulting in the stimulation of cPLA(2) activity in the cell membrane.     

Fine-needle aspiration biopsy in diagnosis of follicular lymphoma: cytomorphologic and immunohistochemical analysis

Follicular lymphoma is a relatively uncommon type of non-Hodgkin's lymphoma (NHL) thought to derive from follicular center cells. There are limitations to fine-needle aspiration in the diagnosis of follicular NHL, and very few studies are available on it. We describe here the cytomorphologic features of eight biopsy-proven cases of follicular NHLs and five biopsy-proven cases of intermediate-grade NHLs. Five cases of reactive lymphoid hyperplasia (RLH) diagnosed on cytology were also studied cytomorphologically. Image morphometry was done in follicular and intermediate-grade NHLs, immunocytochemistry was done in follicular and intermediate-grade NHLs, and immunocytochemistry for bcl-2 expression was studied in five cases of follicular NHLs. The aspirate smears of follicular NHL showed the presence of higher grades, many to abundant (++ to +++) monomorphic lymphoid aggregates, with an increased number of mast cells. Lymphohistiocytic tangles and tingeable body macrophages were not observed in any of the cases. Cytomorphologically, all the cases of intermediate-grade NHL showed a predominantly monomorphic population of lymphoid cells with absent or few grades (+) of lymphoid aggregates. Image morphometric data analysis of each cell parameter for follicular and intermediate-grade NHLs were found to be statistically insignificant (P > 0.05) and hence of little help in diagnosis of follicular vs. low-grade NHLs. Immunocytochemistry for bcl-2 expression in follicular NHL showed variable results, ranging from 0-90% (expressed as bcl-2 index). Certain characteristic cytomorphological features such as the presence of monomorphic lymphoid cell aggregates and an increased number of mast cells are soft indicators for the diagnosis of follicular NHL on aspiration smears. Immunocytochemistry for bcl-2 expression may be of help in cases with clinical and cytological suspicion of lymphoma. Image morphometry has a small role in this regard.     

HLA transgenic mice as models of human autoimmune diseases

MHC class II alleles have been linked to several human autoimmune diseases such as rheumatoid arthritis (RA), Type I diabetes, and multiple sclerosis (MS). Although the mechanisms by which expression of certain MHC class II molecules predispose an individual to a particular autoimmune disease are not known, it is clear that increased susceptibility is associated with the polymorphic regions unique to these predisposing HLA alleles. These polymorphic differences may influence susceptibility by selecting potential autoreactive T cells during thymic education. Alternatively, nonsusceptible alleles may either delete or fail to select these potential autoimmune T cells, thus reducing the possibility of developing disease. In the periphery, the unique specificity of the HLA molecule derived from a susceptible allele may then recognize and present an autoantigenic peptide or foreign peptide that may cross-react with an autoantigen, activating these autoreactive T cells and leading to disease. To dissect these possibilities and to determine the exact role of particular HLA-DR or DQ molecules in disease susceptibility, we have generated several lines of HLA-DR and DQ transgenic mice. In this review, we present data summarizing the functions of these HLA class II molecules using well-established mouse models for autoimmune diseases.