Sequence analysis of hepatitis B virus genomes from an infant with acute severe hepatitis and a hepatitis B e antigen-positive carrier mother

It is well known that fulminant hepatitis B can occur in infants born to hepatitis B e antigen (HBeAg)-negative hepatitis B virus (HBV) carrier mothers, whereas fulminant hepatitis and severe hepatitis are uncommon in infants born to HBeAg-positive mothers. We have encountered an infant with severe acute hepatitis B born to a HBeAg-positive mother. The aim of this study was to determine whether HBV variants contribute to the pathogenesis of fulminant hepatitis and severe hepatitis in an infant born to an HBeAg-positive mother. The nucleotide sequence of HBV genomes from the infant and his HBeAg-positive carrier mother was analyzed. All HBV isolated from the infant and his mother were subtype adr. The sequences of the cloned HBV genomes, each including a part of the X and precore/core regions, isolated from the infant were almost identical (homology of 99.1-99.9%) to those from his mother. There was no mutation in any of the 17 clones examined at nucleotides 1762 and 1764 in the core promoter, which is reported to be associated with fulminant hepatitis. A point mutation at nucleotide 1758 in the second AT-rich region of the basic core promoter was present in all clones. None of the clones had a point mutation at nucleotide 1896 of the precore region. In this study, no specific HBV variants contributing to the development of neonatal severe hepatitis were found. There is a possibility that host factors rather than viral factors play an important role in some cases of severe neonatal hepatitis B.     

Expression of CD44 splice variants in human skin and epidermal tumours

Splice variants of the adhesion molecule CD44 (CD44v) are important in the lymphatic spread of rat carcinoma cells. In several human tumours expression of CD44v correlates with tumour progression. However, little is known about the physiological functions of distinct variant exons. Here we report on the immunohistological evaluation of CD44 expression in normal human skin and epidermal tumours which do not metastasise, or do so vary rarely. Frozen tissues were stained with a panel of monoclonal antibodies, recognizing epitopes of the CD44 standard isoform, as well as of variant exons v5, v6, v7, v7–v8 and v10. Stratum basale and spinosum as well as the root shaft of hairs reacted strongly with the whole panel of anti-CD44 antibodies. Stratum corneum, acinar cells of sebaceous and eccrine sweat glands stained with anti-CD44v5, anti-CD44v6 and anti-CD44v7, but not with anti-CD44v10, the latter recognizing the epithelial isoform (CD44v8–v10) of CD44. Ductal cells of glands and apocrine glands did not express CD44v. Compared with its expression in normal human skin, CD44v expression was reduced in basal cell carcinoma and squamous cell carcinoma of the skin. This was particularly true of CD44v10. The expression of CD44v in normal skin and dermal appendages indicates that not all combinations of variant exons are involved in tumour progression. Since the epithelial isoform is particularly downregulated in basal cell carcinoma and squamous cell carcinoma of the skin, it is unlikely that exons v8–v10 play a role in tumour progression. Rather, they may be of functional importance in maintenance of the epidermal structure.     

CT引导下经皮穿刺活检术在肺癌诊断中的应用

目的 探讨CT引导下穿刺活检术在肺癌诊断中的准确性和并发症发生率。方法 40例使用弹簧芯状活检针经皮穿刺活检，CT扫描确定并引导穿刺途径，达预定位置取材。结果 37例有明确的病理诊断，诊断准确性92．5％。活检后并发气胸3例，咯血2例。结论 CT引导下经皮穿刺活检可以进一步明确肺癌的病理诊断，提高诊断的准确性，并发症发生率低，可为临床提供治疗依据。     

乙型肝炎病毒C基因在毕赤酵母中的表达

目的:研究乙肝病毒核心(C)基因在毕赤(Pichia pastoris)酵母中的表达,以期获得高效表达的具有良好免疫反应性和特异性的重组乙肝病毒核心蛋白(HBcAg)。方法:采用PCR法从含HBV全基因序列的质粒pHBV1中扩增C基因,亚克隆到pGEM-T载体中,经DNA序列分析后将目的基因定向克隆到酵母表达载体pPIC9中,构建重组质粒pPIC9-cAg。然后用电转法将重组质粒转化入酵母菌GS115,0.5%甲醇诱导表达。采用SDS-PAGE、Western blot和ELISA法对表达产物进行分析。结果:限制性内切酶酶切和DNA序列分析证实HBV C基因已正确克隆到酵母表达载体pPIC9中;SDS-PAGE结果显示重组HBcAg在毕赤酵母细胞中表达;ELISA及Western blot分析表明,表达产物具有良好的免疫反应性和特异性,重组HBcAg的滴度可达1∶12 800。结论:成功构建了pPIC9-cAg重组质粒,并在毕赤酵母中高效表达了具有良好免疫反应性和特异性的重组HBcAg,为进一步研制抗-HBc诊断试剂盒奠定了基础。     

Spinal neuronal inhibition and EEG synchrony by electrical stimulation in subcortical forebrain regions of the cat

Summary In cats anaesthetized with sodium pentobarbital and 70% N₂O, single lumbar dorsal horn neurons were excited by controlled noxious radiant heating of glabrous hindpaw skin. The EEG was recorded from the pericruciate cortex and posterior lateral gyrus. Subcortical forebrain sites where electrical stimulation inhibited dorsal horn neuronal heat-evoked responses contralaterally were identified by mapping the caudate nucleus, internal capsule, septum, nucleus accumbens and basal forebrain regions. Inhibitory sites were mainly located in the ventral forebrain (ventral septum, diagonal band, basal forebrain). The caudate nucleus and internal capsule had a low incidence and effectiveness of inhibitory sites. In the basal forebrain, the incidence and effectiveness of inhibitory sites decreased from caudal to rostral regions. There was a rostral limit of inhibitory sites, both medially and laterally. The magnitude of inhibition increased with graded increases in brain stimulation intensity. The mean incremental increase in inhibition was greater for caudal than for rostral basal forebrain sites. Mean stimulus currents for threshold of inhibition and for inhibition to 50% of control heat responses were lower for caudal than for rostral sites. Responses of the dorsal horn neurons to increasing temperatures of noxious skin heating were monotonic linear functions over the temperature range studied (48–53° C). Stimulation in both rostral and caudal basal forebrain decreased the slope of this stimulus-response function, with a greater decrease for caudal sites. Cortical EEG synchronization was evoked by stimulation in the caudate nucleus and rostral basal forebrain. For both regions, most synchronogenic sites did not produce descending inhibition of dorsal horn neurons. The significance of these findings in relation to descending inhibition from other brain regions and stimulation-produced analgesia is discussed.     

Diagnostic impact of core-needle biopsy on fine-needle aspiration of non-Hodgkin lymphoma

We retrospectively reviewed 74 fine-needle aspiration (FNA) cases of presumptive non-Hodgkin lymphoma (NHL). All the cases had cytology and core-needle biopsy and 53 cases had concurrent flow cytometric analysis. FNA (cytology and flow cytometry) and core-needle biopsy were evaluated independently. FNA was diagnostic of diffuse large B-cell lymphoma (DLBL) in 25% (13/53) of cases and small B-cell NHL in 15% (8/53) of cases, whereas core-needle biopsy was diagnostic of DLBL in 37% (27/74) of cases and small B-cell NHL in 8% (6/74) of cases. Subclassification of small B-cell NHL was reached in 3/6 cases by core-needle biopsy. Insufficient cases were observed in both FNA (47%; 25/53) and core-needle biopsy (28%; 21/74) groups. With the combination of FNA and core-needle biopsy, diagnostic cases of DLBL increased to 43% (32/74) and insufficient samples were reduced to 16% (12/74). There was no clear advantage in the diagnosis and classification of small B-cell NHL by adding core-needle biopsy to FNA (14%; 10/74). We conclude that core-needle biopsy is a useful adjunct to FNA in the diagnosis of DLBL and shall be encouraged. In small B-cell NHL, core-needle biopsy does not add to the diagnostic ability of FNA. Cases insufficient for diagnosis may be seen in both core-needle biopsy and FNA. A combined approach reduces the number of insufficient cases and is recommended in routine FNA practice.