海风藤酚、甲基海风藤酚、海风藤醇A和海风藤醇B对兔血小板聚集的影响

海风藤酚、甲基海风藤酚、海风藤醇Ａ和海风藤醇Ｂ均有抑制血小板激活因子（ＰＡＦ）诱导的兔血小板聚集作用，ＩＣ_（５０）分别为１７．９、９．２、１４２．０、１４．０μｍｏｌ·Ｌ~（－１）。经阿司匹林（ＡＳＡ）、磷酸肌酸／磷酸肌酸激酶（ＣＰ／ＣＰＫ）预处理的兔洗涤血小板，甲基海风藤酚和海风藤醇Ｂ仍能抑制ＰＡＦ诱导的兔血小板聚集，ＩＣ_（５０）为９．０、１６．５μｍｏｌ·Ｌ~（－１）。同时，４种成分对于二磷酸腺苷（ＡＤＰ），花生四烯酸（ＡＡ）诱导的血小板聚集抑制作用较弱，海风藤Ｂ能使ＰＡＦ诱导血小板聚集量－效曲线平行右移，ＥＣ_（５０）由１．５９ｎｍｏｌ·Ｌ~（－１）升为２０．６ｎｍｏｌ·Ｌ~（－１）。结果表明：４种成分能选择性拮抗ＰＡＦ对兔血小板的聚集作用。     

Characterization of high-affinity receptors for bombesin/gastrin releasing peptide on the human prostate cancer cell lines PC-3 and DU-145: Internalization of receptor bound 125I-(Tyr4) bombesin by tumor cells

Specific receptors for bombesin/gastrin releasing peptide (GRP) on the androgen-independent human prostate cancer cell lines PC-3 and DU-145 were characterized. No specific binding of ¹²⁵I-[Tyr⁴]-bombesin to the androgen-dependent human prostate cancer cell line LNCaP was detectable. The binding of ¹²⁵I-[Tyr⁴]-bombesin to PC-3 and DU-145 cells was found to be time- and temperature-dependent, saturable, and reversible. Scatchard analysis revealed a single class of binding sites with high affinity (K_d 9.8 × 10^?11 M for PC-3, and 9.1 × 10-¹¹ M for DU-145 cells at 25°C) and with a binding capacity of 44,000 binding sites/cell and 19,000 binding sites/cell, respectively. Bound ¹²⁵I-[Tyr⁴]-bombesin was rapidly internalized by PC-3 cells. The nonhydrolyzable GTP analog GTP-gamma-S caused a dose-dependent inhibition of ¹²⁵I-[Tyr⁴]-bombesin binding to PC-3 and DU-145 cells, indicating that a G-protein (guanine nucleotide-binding protein) couples the bombesin receptor to intracellular effector systems. Bombesin and GRP(14-27) inhibited the binding of ¹²⁵I-[Tyr⁴]-bombesin to both cell lines in a dose-dependent manner with inhibition constants (K_i of 0.5 nM and 0.4 nM, respectively. Both cell lines express the bombesin/GRP preferring bombesin receptor subtype, since, in displacement studies, neuromedin B was more than 200 times less potent than bombesin and GRP(14-27) in inhibiting the binding of ¹²⁵I-[Tyr⁴]-bombesin. Two synthetic bombesin/GRP antagonists, RC-3095 and RC-3110, powerfully inhibited the specific binding of ¹²⁵I-[Tyr⁴]-bombesin with K_i 0.92 nM and 0.26 nM on PC-3 cells, and 3.3 nM and 0.89 nM on DU-145 cells, respectively. These findings indicate that the PC-3 and DU-145 human prostate cancer cell lines possess specific high-affinity receptors for bombesin/GRP, and are suitable models for the evaluation of the antineoplastic activity of new bombesin/GRP antagonists in the treatment of androgen-independent prostate cancer. © 1994 Wiley-Liss, Inc.     

PRIMARY LYMPHOMA OF THE PANCREAS

Lymphoma of the pancreas is uncommon. Secondary invasion from contiguous, retroperitoneal lymph node disease is the predominant mode of involvement. Lymphoma originating in and remaining localized to the pancreas is very rare. A case of primary lymphoma confined to the pancreas, in a 35 year old man, is described. Only two other similar cases could be found in the English literature.     

乙型肝炎病毒免疫逃避株表面抗原决定簇编码区的序列分析

应用聚合酶链反应（ＰＣＲ）产物直接测序，在国内首次发现１例持续高滴度乙型肝炎表面抗原（ＨＢｓＡｇ）和抗一ＨＢｓ共存者携带的乙型肝炎病毒ＤＮＡ第５３２位碱基Ａ被Ｇ取代，推导其“ａ”决定簇中第１２６位苏氨酸被丙氨酸取代，提示该株“ａ”决定簇第一个结构环疏水性增加，由此可能导致其抗原性改变，而诱发免疫逃避株形成。     

Failure of intensive chemotherapy in poor prognosis non-Hodgkin's lymphoma

In an attempt to improve response and survival rates in patients with non-Hodgkin's lymphoma, a relatively intense six drug regimen MATCOP was developed comprising four-weekly cycles of methotrexate (100mg/m², IV_Y day 8), Adriamycin (30mg/m², IV_Y days 1,2), teniposide (75 mg/rn², IV, day 1), cyclophophamide (300 mg/m², po, days one to five), Oncovin (1.4 mg/m², IV: maximum 2 mg, days 8,15) and prednisolone (100 mg, po, days one to five). A randomised trial was conducted comparing MATCOP with the standard CHOP regimen, comprising three-weekly cycles of cyclophosphamide (750 mg/m², IV, day 1), Adriamycin (50 mg/m², IV, day 1), Oncovin (1.4 mg/m² IV: maximum 2 mg, day 1) and prednisolone (100 mg, PO, days two to six). Eighty patients with large cell lymphoma, diffuse mixed small cleaved and large cell lymphoma or diffuse small cleaved cell lymphoma were randomised, 47 to MATCOP and 33 to CHOP. MATCOP patients experienced increased granulocytopenia, thrombocytopenia (p 0.0001), mucositis (p= 0.002) and infections (p= 0.01) compared to CHOP patients. Complete response rates were similar: 66% for MATCOP patients and 61% for CHOP patients. There were no apparent differences in the time to relapse for patients achieving CR, the time to treatment failure or the overall survival time. Thus despite an increase in toxicity, the more intense regimen MATCOP failed to confer any therapeutic benefit compared with the standard CHOP regimen. Survival was not influenced but toxicity was increased by dose intensification. (Aust NZ J Med 1992; 22: 123–128.)     

Fine-needle aspiration cytology of an endometrioid-like variant of yolk sac tumor.

A 36-year-old male with a history of immature teratoma and embryonal carcinoma of the testis was admitted to the hospital for abdominal pain and fever. A CT scan revealed a large right abdominal mass. The patient's serum alpha-fetoprotein (AFP) was 46.8 ng/ml (reference < 25 ng/ml). Fine-needle aspiration (FNA) of the mass revealed malignant glandular cells. Chemotherapy was instituted, followed by resection of the large abdominal mass. The tumor was grossly encapsulated, consisting of large areas of necrotic, hemorrhagic tissue surrounded by smaller, multiloculated cysts. Microscopically, the tumor had a villoglandular pattern and variably stratified tall columnar cells. A prominent feature of the columnar cells was supranuclear and subnuclear vacuolization. Intracytoplasmic PAS-positive, diastase-resistant hyaline globules were occasionally present. AFP by immunoperoxidase was prominent within the tumor. This recurrence of the previously diagnosed testicular teratoma with embryonal carcinoma represents a yolk sac tumor with components strongly resembling endometrioid carcinoma, a variant only recently described in eight cases of ovarian origin (Clement et al.: Am J Surg Pathol 1987; 11(10):767-778). We believe this is the first reported case of an endometrioid-like variant of testicular yolk sac tumor and also the first report of the FNA cytology findings in this variant.     

Treatment of chronic hepatitis B

SUMMARY. Chronic infection with the hepatitis B virus (HBV) is a major cause of worldwide morbidity and mortality. A large number of therapeutic approaches has been tried, including interferon (IFN), nucleoside analogues and immunomodulators. To date controlled clinical trials have shown that only IFN is of long-term value but many patients fail to respond to treatment. New approaches to treating patients with IFN-resistant hepatitis B are currently undergoing clinical and experimental evaluation, and it seems likely that new therapeutic agents will be available in the near future.     

Buoyant density characterization of neoplastic cell populations in patients with chronic B-lymphocytic leukemia

Leukemic cells from a series of patients with chronic B-lymphocytic leukemia (CLL) were analyzed for their buoyant density on discontinuous Percoll gradients. The density profile varied markedly between different patients and also between samples from different body compartments within the same patient. A good correlation was observed between buoyant density and maturation stage of the leukemic clones as judged by Ig-expression and their reactivity with a panel of monoclonal antibodies. Phorbol-ester-induced changes in the leukemic cells were found to be accompanied by a general decrease in their buoyant density. No correlation between density and clinical parameters such as cell counts, clinical stage and survival could be noted. Buoyant density characterization of leukemic B-cell populations is seen as a useful, rapid and simple marker of compartmentalization within the B-lymphocyte maturation spectrum but its clinical relevance remains to be established.     

Detection of Epstein Barr virus in an hepatic leiomyomatous neoplasm in an adult human immunodeficiency virus 1-infected patient

We report the first case of a human immunodeficiency virus (HIV)-related primary hepatic leiomyoma in an adult patient. The diagnosis was made at autopsy and confirmed by immunohistochemistry. Epstein Barr virus (EBV) was identified in tumour cells by in situ hybridization. Review of the literature revealed 13 cases of visceral myogenic tumours occuring in acquired immunodeficiency syndrome children, and only 2 cases in adults. One was a spinal epidural leiomyoma, the other multiple smooth muscle tumours of the colon and adrenal gland. This is the first report of EBV in smooth muscle neoplastic cells in an HIV-infected adult patient.     

Human xenoreactive natural antibodies of the IgM isotype activate pig endothelial cells

Abstract: Preformed, xenoreactive natural antibodies (XNA) and complement (C) are involved in the initiation of vascular rejection of organs transplanted between discordant species, presumably by stimulating donor organ endothelial cells (EC). Although C is known to play a role in the activation of EC, it has not been clear whether the antibodies serve only to anchor the initial components of C, and thus permit the C cascade to proceed, or whether the antibodies themselves deliver a signal to the EC. We have tested affinity-purified human IgM containing XNA (IgM-XNA) for its ability to stimulate in vitro the up-regulation of genes in pig EC. Northern blot analysis shows that IgM, which contains XNA, stimulates mRNA accumulation for certain genes (including IL-8, PAI-1, and ECI-7, a new gene that we have found is associated with EC activation), but not others known to be up-regulated in response to TNF, IL-1 or LPS. Our results show that XNA provide a signal to EC, and thus may themselves participate in activation of EC and consequent vascular rejection.