天然角蛋白自身反应性B细胞亚群及功能的分析

目的:明确天然角蛋白反应性B细胞的亚群及解剖定位,初步分析其分泌天然抗角蛋白自身抗体(anti-keratinautoantibody,AKautoAb)的能力。方法:取SPF级C57BL/6小鼠的脾细胞和腹腔细胞,荧光抗体染色后用流式细胞仪分析角蛋白反应性B细胞亚群。将脾脏和腹腔淋巴细胞体外培养后,用ELISA分析AKautoAb的滴度,用ELISPOT法分析分泌AKautoAb的B细胞数。结果:腹腔中几乎所有结合角蛋白的B细胞均为B-1a细胞,脾脏中结合角蛋白的B细胞以边缘带B细胞为主。腹腔细胞中分泌AKautoAb的细胞数显著多于脾细胞,其培养上清中AKautoAb的滴度显著高于脾细胞。结论:角蛋白反应性B细胞存在于3个成熟B细胞亚群:B-1细胞、滤泡B细胞和边缘带B细胞,其中CD5 的B-1a细胞具有活跃的分泌AKautoAb的能力。     

Expression of retinoblastoma protein in human growth hormone-secreting pituitary adenomas

The retinoblastoma gene (RB1) is a tumor-suppressor gene in chromosomal region 13q14.2. Its role in the pathogenesis of pituitary tumors has not been fully clarified. Some studies have shown that losses in this chromosomal region are related to aggressive tumor behavior, although the retinoblastoma protein (pRB) is still expressed. Conversely, lack of expression of pRB was observed in one fourth of GH-secreting pituitary adenomas (GH-tumors). In order to further study the expression of pRB in GH-tumors, we evaluated this protein in 49 tumors from patients with acromegaly (20 noninvasive, 25 invasive, and 4 with no information) and 8 normal pituitaries using immunohistochemistry (IHC). Nuclear staining for pRB ranged from 0 to 90% (median 40%) in the tumors and from 40 to 80% (median 58%) in normal pituitaries. In 10 tumors (20% of total) the adenomatous cells were negative (5 cases) or had very low labeling (5 cases) for pRB. Sixty three percent (31/49) of the tumors showed staining in 10–80% of the cells and in 16% (8/49) of the cases >80% of the adenomatous cells were positive for pRB. The expression of pRB was not different in invasive and noninvasive tumors. In conclusion, pRB is underexpressed in a subgroup of GH-tumors, and this may represent an early event in the pathogenesis of this tumor subtype.     

Anti-HBV effects of CpG oligodeoxynucleotide-activated peripheral blood mononuclear cells from patients with chronic hepatitis B

Unmethylated CpG dinucleotides in bacterial DNA or synthetic oligodeoxynucleotides containing immunostimulatory CpG motifs (CpG ODN) are known as a potent Th1-like immune enhancer in vertebrates. Chronic hepatitis B is the immunocompromising condition. We therefore investigated the effects of CpG ODN on cultured cells from chronic hepatitis B patients and healthy controls. The inhibitory effects of CpG ODN on hepatitis B virus (HBV) were also studied. The secretion of IFN-alpha by CpG ODN-activated peripheral blood mononuclear cells (PBMCs) from chronic hepatitis B patients and healthy controls was significantly increased when compared with PBMCs alone or GpC ODN-stimulated PBMCs. After activation with CpG ODN, the IFN-alpha secretion by chronically HBV-infected patient PBMCs is less than that by healthy control PBMCs. Treatment of HepG2 2.2.15 cells with culture supernatants of PBMCs activated by CpG ODN can significantly suppress the secretion of HBsAg, HBeAg and HBV DNA as compared with that of PBMCs without CpG ODN activation under the same conditions. No inhibitory effect on the replication of HBV was found for CpG ODN treatment alone. Our results indicated that CpG ODN could efficiently enhance the immune response of chronic hepatitis B patients. Moreover, the CpG ODN-activated PBMCs from chronic hepatitis B patients were able to significantly inhibit HBV replication in vitro, suggesting that CpG ODN may be a potential immunoregulator against HBV infection in the future.     

抗病毒治疗对乙型肝炎病毒感染者肾移植术后临床转归的影响

目的 探讨乙型肝炎病毒感染者肾移植术后临床转归及治疗对策.方法 将术前乙肝病毒标志物阳性(HBsAg阳性、HBeAg阳性或HBeAb阳性、HBV DNA阳性或阴性)的32例肾移植术后患者分为抗病毒治疗组和无抗病毒治疗组两组.观察两组(术前1周至术后9年)的肝功能(ALT、AST、TBIL、PT)变化、病毒复制(HBV DNA)及存活情况.结果 抗病毒治疗组23例患者肝功能损害复常率为82.60%,存活率为82.60%,HBV DNA(PCR法)下降(≥2 log10)或保持低复制率为86.95%;未抗病毒组9例患者肝功能损害复常率为22.22%,存活率为11.11%,HBV DNA(PeR法)下降(≥2log10)或保持低复制率为11.11%.抗病毒组肝功能复常率、存活率及HBV DNA下降或保持低复制率高于无抗病毒组,两组比较差异有统计学意义(P<0.05).19例拉米夫定治疗患者6例出现病毒学反弹31.58%,1例加用阿德福韦酯,2例换用恩替卡韦后好转,其余3例肝功能衰竭死亡.结论 持续有效的抗病毒治疗可以有效控制乙肝病毒复制,促进肝功能恢复,减少肝衰竭发生,提高乙肝病毒感染者肾移植术后患者存活率.在治疗过程中出现病毒学反弹应及时换用或加用有效药物减少肝衰竭发生.     

The linear mitochondrial plasmid pAL2-1 of a long-lived Podospora anserina mutant is an invertron encoding a DNA and RNA polymerase

The molecular characterization of an additional DNA species (pAL2-1) which was identified previously in a long-lived extrachromosomal mutant (AL2) of Podospora anserina revealed that this element is a mitochondrial linear plasmid. pAL2-1 is absent from the corresponding wild-type strain, has a size of 8395 bp and contains perfect long terminal inverted repeats (TIRs) of 975 bp. Exonuclease digestion experiments indicated that proteins are covalently bound at the 5 termini of the plasmid. Two long, non-overlapping open reading frames, ORF1 (3,594 bp) and ORF2 (2847 bp), have been identified, which are located on opposite strands and potentially encode a DNA and an RNA polymerase, respectively. The ORF1-encoded polypeptide contains three conserved regions which may be responsible for a 3–5 exonuclease activity and the typical consensus sequences for DNA polymerases of the D type. In addition, an amino-acid sequence motif (YSRLRT), recently shown to be conserved in terminal proteins from various bacteriophages, has been identified in the amino-terminal part of the putative protein. According to these properties, this first linear plasmid identified in P. anserina shares all characteristics with invertrons, a group of linear mobile genetic elements.     

Retinoblastoma and p53 gene product expression in breast carcinoma: Immunohistochemical analysis and clinicopathologic correlation

We examined 100 breast cancers for retinoblastoma (Rb) and p53 protein expression by immunohistochemistry using the PMG3.245 and PAb 1801 antibodies. We assessed percentages of reactive cells and their intensity, as well as staining patterns. The results were correlated with neu protein reactivity and a panel of variables, including age, tumor size and type, nuclear grade, estrogen receptor/progesterone receptor content, and lymph node status. Retinoblastoma protein negativity, either partial or complete, was noted in 47% of cases. Surprisingly, a relatively stronger Rb reaction was seen in some high nuclear grade tumors. p53 positivity was found in 23% of cases and was a significant predictor of Rb loss. p53 also was correlated with poorly differentiated (nuclear grade III) neoplasms and neu expression but not with negative ER status. Tissue distribution profiles for Rb-negative and p53-positive cells were variable in this series, with both uniform and heterogeneous patterns observed. This suggests that Rb and p53 alterations may represent early or late events in transformation. Our findings further implicate Rb and p53 derangements in mammary oncogenesis.     

Acute-phase protein synthesis in human hepatoma cells: differential regulation of serum amyloid A (SAA) and haptoglobin by interleukin-1 and interleukin-6.

Interleukin-6 (IL-6, BSF-2 or IFN-beta 2) is thought to be the major regulator of the acute-phase protein response that follows tissue injury and inflammation, with interleukin-1 (IL-1), tumour necrosis factor and more recently, LIF or HSF III, slightly stimulatory on only certain acute phase proteins. The synthesis of the major acute-phase protein SAA, originally described as being synthesized in response to IL-1, has been claimed recently to be mainly under IL-6 regulation. Our results show that in the human hepatoma cell line HuH-7, IL-1 is the major stimulating cytokine increasing SAA synthesis by a factor in excess of 100-fold. We also show that under most conditions interleukin-6 and tumour necrosis factor stimulate additively in combination with IL-1. Isoelectric focusing has demonstrated that SAA1 and SAA2 alpha are expressed but not SAA2 beta. The HuH-7 cell line is IL-6 responsive since haptoglobin is stimulated mainly by IL-6.     

Occurrence of secretogranin II in the prolactin-immunoreactive neurons of the rat lateral hypothalamus: an in situ hybridization and immunocytochemical study

The occurrence of secretogranin II in a neuron population of the rat lateral hypothalamus specifically detected by an anti-serum to ovine prolactin was examined. As this population was previously reported to synthesize dynorphin, the distribution of neurons recognized by ovine prolactin-, dynorphin B- and secretogranin II anti-sera was investigated on adjacent sections of hypothalami. The prolactin immunoreactive neurons were the only cells in the lateral hypothalamus to be stained by secretogranin II anti-serum. Moreover, coupling immunocytochemical detection and in situ hybridization with an oligonucleotide probe complementary to secretogranin II mRNA showed that these neurons expressed the secretogranin II gene. These new findings should help to study the physiological role of the prolactin immunoreactive neurons of the lateral hypothalamus.