Serum hepatitis B virus DNA in healthy HBsAg-negative Chinese adults evaluated by polymerase chain reaction

Serum hepatitis B virus (HBV) DNA was assayed using polymerase chain reaction, in 107 HBsAg-negative normal Chinese subjects. The results showed that eight subjects (7.5%) had HBV DNA. In the subgroup with antibody to hepatitis B surface antigen (anti-HBs) and to hepatitis B core antigen (anti-HBc), 7.3% (5/68) were positive for HBV DNA; HBV DNA was not detected in six individuals with anti-HBs only and in nine with anti-HBc only. In four persons with anti-HBc and anti-HBe, one had HBV DNA. In 20 subjects negative for all hepatitis B serological markers, two (10%) were found to have HBV DNA. This study indicates that serological markers are not adequate to rule out HBV infection, and it further implies that present blood donor screening methods may need improving.     

人血管抑素A K(1-3)基因的克隆表达、纯化及活性鉴定

目的 克隆人Angiostatin K(1-3)基因,获得有活性的重组人血管抑素蛋白,为进一步开发应用奠定基础.方法 以人新鲜肝脏组织为材料,通过RT-PCR得到人Angiustatin基因的AK(1-3)片段.构建重组质粒pET30a-Angiostatin,转化表达菌Rosetta(DE3),对转化子进行诱导表达,利用Ni-NTA亲和层析纯化目的 产物,并验证其活性.结果 获得了人Angiostatin基因AK(1-3)片段的正确序列,表达和纯化了人血管抑素蛋白,表达量占菌体总蛋白的30%,纯化后证明表达产物具有较高纯度(达到90%).结论 Anginstatin K(1-3)可在原核融合蛋白表达载体中表达,且得到有活性的目的 蛋白.     

Parental origin of de novo chromosome 9 deletions in del(9p) syndrome

Parental origin of de novo deletions in the short arm of chromosome 9 in patients with a clinical diagnosis of del(9p) syndrome was assessed in 13 patients using polymerase chain reaction (PCR) analysis of highly polymorphic dinucleotide repeat micro-satellite markers located in the putative deleted region. The deletion was found to be of paternal origin in 9 cases and of maternal origin in the remaining 4 cases, suggesting that the molecular event resulting in the deletion occurs in both male and female gametogenesis and that genomic imprinting does not appear to play a role in the patho-genesis of del(9p) syndrome. © 1995 Wiley-Liss, Inc.     

Growth hormone as an early embryonic growth and differentiation factor

In this review we consider the evidence that growth hormone (GH) acts in the embryo as a local growth, differentiation, and cell survival factor. Because both GH and its receptors are present in the early embryo before the functional differentiation of pituitary somatotrophs and before the establishment of a functioning circulatory system, the conditions are such that GH may be a member of the large battery of autocrine/paracrine growth factors that control embryonic development. It has been clearly established that GH is able to exert direct effects, independent of insulin-like growth factor-I (IGF-I), on the differentiation, proliferation, and survival of cells in a wide variety of tissues in the embryo, fetus, and adult. The signaling pathways behind these effects of GH are now beginning to be determined, establishing early extrapituitary GH as a bona fide developmental growth factor.     

人血管抑素A K(1-3)基因的克隆表达、纯化及活性鉴定

目的 克隆人Angiostatin K(1-3)基因,获得有活性的重组人血管抑素蛋白,为进一步开发应用奠定基础.方法 以人新鲜肝脏组织为材料,通过RT-PCR得到人Angiustatin基因的AK(1-3)片段.构建重组质粒pET30a-Angiostatin,转化表达菌Rosetta(DE3),对转化子进行诱导表达,利用Ni-NTA亲和层析纯化目的 产物,并验证其活性.结果 获得了人Angiostatin基因AK(1-3)片段的正确序列,表达和纯化了人血管抑素蛋白,表达量占菌体总蛋白的30%,纯化后证明表达产物具有较高纯度(达到90%).结论 Anginstatin K(1-3)可在原核融合蛋白表达载体中表达,且得到有活性的目的 蛋白.     

A new, simple and rapid method for enumerating human T lymphocytes in full blood: the E. coli (ATCC 11303) rosette test

A new bacterial rosette technique for enumerating T lymphocytes is described. E. coli (strain B; ATCC 11303), fixed in formaldehyde after overnight growth in thioglycolate medium, are mixed with washed whole blood cells (100 μl) and after incubation at 4°C, slides are made, stained and counted. The nature of the lymphocytes forming E. coli rosettes was demonstrated by comparing their cytochemical staining characteristics with those of E rosetted lymphocytes, and by mixed E. coli and E, mouse E rosette and Fc receptor tests, and by mixed E. coli rosette tests and anti-Ig staining. E. coli and E rosette tests in controls and pediatric patients were also compared. The results show that T_μ and T_γ cells rosette with E. coli.     

Chitosan hydrogel as a drug delivery carrier to control angiogenesis

An aqueous solution of photocrosslinkable chitosan containing azide groups and lactose moieties (Az-CH-LA) incorporating paclitaxel formed an insoluble hydrogel within 30 s of ultraviolet light (UV) irradiation. The chitosan hydrogel showed strong potential for use as a new tissue adhesive in surgical applications and wound dressing. The fibroblast growth factor (FGF)-2 molecules retained in the chitosan hydrogel and in an injectable chitosan/IO₄-heparin hydrogel remain biologically active, and were gradually released from the hydrogels as they biodegraded in vivo. The controlled release of biologically active FGF-2 molecules from the hydrogels caused induction of angiogenesis and collateral circulation occurred in healing-impaired diabetic (db/db) mice and in the ischemic limbs of rats. Paclitaxel, which is an antitumor reagent, was also retained in the chitosan hydrogel and remained biologically active as it was released on degradation of the hydrogel in vivo. The chitosan hydrogels incorporating paclitaxel effectively inhibited tumor growth and angiogenesis in mice. The purpose of this review is to describe the effectiveness of chitosan hydrogel as a local drug delivery carrier for agents (e.g., FGF-2 and paclitaxel) to control angiogenesis. It is thus proposed that chitosan hydrogel may be a promising new local carrier for drugs such as FGF-2 and paclitaxel to control vascularization.     

Quantitation of hepatitis B viral DNA by solution hybridization: Comparison with DNA polymerase and hepatitis B e antigen during antiviral therapy

Serological markers of hepatitis B virus (HBV) replication were assessed in a randomized, controlled trial of prednisone withdrawal followed by α -interferon in the treatment of chronic hepatitis B. HBV DNA levels in more than 700 serial serum samples from 41 patients were determined by a sensitive and quantitative solution hybridization assay. Results were compared with HBV DNA polymerase (DNAp) activity and hepatitis B e antigen (HBeAg) in 21 untreated controls and 20 treated patients. Among treated patients, the mean pretherapy HBV DNA values were higher in nonresponders than in responders. During prednisone treatment, DNA levels increased an average of 2.1-fold in responders and 1.4-fold in nonresponders. During the 2-week rest interval between prednisone and interferon, DNA values fell an average of 57% in responders. In contrast, the mean DNA values in nonresponders did not change during the same interval. This early distinction between responders and nonresponders was not apparent from DNAp or HBeAg results. During interferon treatment, HBV DNA became undetectable in responders and remained negative during a 1-year follow-up. DNA in nonresponders declined to 14% of baseline during interferon treatment but increased to pretherapy levels after treatment. DNAp values generally paralleled HBV DNA values, but DNAp activity showed more variability and lower sensitivity than did the hybridization assay results. HBeAg values varied independently of HBV DNA and DNAp with a much delayed decline in responders. These results indicate that HBV DNA, when measured quantitatively by a sensitive solution hybridization assay, is an early predictor of the effects of antiviral agents on replication.     

Correlation between soluble serum CD16 (sCD16) levels and disease stage in patients with multiple myeloma

CD16, the type III receptor for IgG, is expressed on neutrophils, natural killer cells, and some T lymphocytes, mast cells, and activated monocytes but not on cells of the B-lymphocyte lineage including plasma cells. It is also produced in a soluble form found in serum. We analyzed sera from 165 multiple-myeloma patients, 29 patients with monoclonal gammopathies of unknown significance, and 20 normal disease-free donors. We found that the level of soluble CD16 was significantly decreased in sera from patients with multiple myeloma compared to sera from healthy and monoclonal gammopathies of unknown significance donors (P=0.0001). In addition, a stage-dependent decrease in soluble CD16 was observed, with a highly significant difference (P=0.004) between stage I and stage II+III myeloma patients. The correlation between the myeloma stage and the serum level of soluble CD16, which is related to the host response, was found to be more sensitive than that of ₂-microglobulin, which reflects the tumor burden. The concomitant evaluation of the serum levels of these two markers allows better staging and therefore has a more precise prognostic value.