小鼠皮肤超氧化物歧化酶活性与枸杞多糖的干预

目的:观察枸杞多糖对皮肤胶原代谢和自由基产生的影响,探讨其抗皮肤衰老的作用。方法:实验于2005-06/2006-05在广东医学院整形外科研究所完成。①实验材料:清洁级昆明小鼠60只,月龄2个月,体质量16～24g,雌雄各半。②实验分组:将小鼠随机分为正常对照组、衰老模型组和抗衰老模型组,每组20只。③实验干预:模型组每日用D-半乳糖溶液皮下注射制造衰老模型,用量和时间为80mg/(kg·d)7d,120mg/(kg·d)14d,140mg/(kg·d)14d,180mg/(kg·d)7d。正常对照组每日注射同体积的生理盐水。抗衰老模型组在注射D-半乳糖期间以枸杞多糖灌胃,剂量为20mg/(kg·d),正常对照组和衰老组则以同体积的生理盐水代之灌胃。④实验评估:42d后切取小鼠颈背部皮肤,测定超氧化物歧化酶活力、羟脯氨酸和丙二醛含量。结果:56只小鼠进入结果分析(4只死亡)。①小鼠皮肤超氧化物歧化酶活力:与正常对照组相比,衰老组和抗衰老组小鼠皮肤超氧化物歧化酶活力降低,差异有显著性意义(P<0.01);抗衰老组与衰老模型组比较,超氧化物歧化酶活力增加,差异有显著性意义(P<0.01)。②与正常对照组相比,衰老组和抗衰老组小鼠皮肤羟脯氨酸和丙二醛含量增加,差异有显著性意义(P<0.01);抗衰老组与衰老组比较,羟脯氨酸和丙二醛含量均降低,差异有显著性意义(P<0.01)。结论:枸杞多糖改善皮肤老化的作用与提高小鼠皮肤超氧化物歧化酶活力,降低羟脯氨酸、丙二醛含量,影响胶原代谢有关。     

Therapy of patients with human T-cell lymphotrophic virus I-induced adult T-cell leukemia with anti-Tac, a monoclonal antibody to the receptor for interleukin-2

Human T-cell lymphotropic virus I (HTLV-I)-induced adult T-cell leukemia (ATL) cells constitutively express interleukin-2 (IL-2) receptors identified by the anti-Tac monoclonal antibody (MoAb), whereas normal resting cells do not. This observation provided the scientific basis for a trial of intravenous anti-Tac in the treatment of nine patients with ATL. The patients did not suffer untoward reactions and did not have a reduction in the normal formed elements of the blood, and only one of the nine produced antibodies to the anti-Tac MoAb. Three patients had transient mixed, partial, or complete remissions lasting from 1 to more than 8 months after anti-Tac therapy, as assessed by routine hematologic tests, immunofluorescence analysis of circulating cells, and molecular genetic analysis of HTLV-I provirus integration and of the T-cell receptor gene rearrangement. The precise mechanism of the antitumor effects is unclear; however, the use of a MoAb that prevents the interaction of IL-2 with its receptor on ATL cells provides a rational approach for the treatment of this malignancy.     

Efficient retroviral gene transfer to purified long-term repopulating hematopoietic stem cells

Efficient gene delivery to multipotential hematopoietic stem cells would greatly facilitate the development of effective gene therapy for certain hematopoietic disorders. We have recently described a rapid multiparameter sorting procedure for significantly enriching stem cells with competitive long-term lymphomyeloid repopulating ability (CRU) from 5-fluorouracil (5-FU)-treated mouse bone marrow. The sorted cells have now been tested as targets for retrovirus-mediated delivery of a marker gene, NeoR. They were cocultured for 4 days with fibroblasts producing a high titer of retrovirus in medium containing combinations of the hematopoietic growth factors interleukin-3 (IL-3), IL-6, c-kit ligand (KL), and leukemia inhibitory factor (LIF) and then injected into lethally irradiated recipients, together with sufficient "compromised" bone marrow cells to provide short-term support. Over 80% of the transplanted mice displayed high levels (> or = 20%) of donor- derived leukocytes when analyzed 4 to 6 months later. Proviral DNA was detected in 87% of these animals and, in half of them, the majority of the hematopoietic cells were marked. Thus, infection of the stem cells was most effective. The tissue and cellular distribution of greater than 100 unique clones in 55 mice showed that most sorted stem cells had lymphoid as well as myeloid repopulating potential. Secondary transplantation provided strong evidence for infection of very primitive stem cells because, in several instances, different secondary recipients displayed in their marrow, spleen, thymus and day 14 spleen colony-forming cells the same proviral integration pattern as the primary recipient. Neither primary engraftment nor marking efficiency varied for stem cells cultured in IL-3 + IL-6, IL-3 + IL-6 + KL, IL-3 + IL-6 + LIF, or all four factors, but those cultured in IL-3 + IL-6 + LIF appeared to have lower secondary engraftment potential. Provirus expression was detected in 72% of the strongly marked mice, albeit often at low levels. Highly efficient retroviral marking of purified lymphomyeloid repopulating stem cells should enhance studies of stem cell biology and facilitate analysis of genes controlling hematopoietic differentiation and transformation.     

Palmar Type of Median Artery as a Source of Superficial Palmar Arch: A Cadaveric Study with Its Clinical Significance

The superficial palmar arch (SPA) and its contributing arteries are highly variable. The palmar type of median artery (PMA) can be involved in the formation of the SPA by replacing the superficial palmar branch of the radial artery (RA) or the ulnar artery (UA). The present study was undertaken to investigate the presence of the PMA and its contribution in the formation of SPA in 42 cadavers (84 upper limbs) of Indian origin. When there was a PMA, its outer diameter was measured in the carpal tunnel. The PMA was found in 13 upper limbs (15.4%), and of these ten incidences (11.9%), the PMA took part in the formation of SPA, and in three instances (3.5%), the PMA did not make up part of the SPA. Out of the ten cases in which the PMA contributed to the formation of SPA, in six cases (7.1%), the PMA anastomosed with the UA; in three cases (3.5%), the PMA anastomosed with both the UA and the RA, and in one incidence (1.1%), the PMA joined the arteria radialis indicis (deep branch of the RA) to complete the SPA. The outer diameters of the median arteries varied between 0.8 and 2.6 mm with the mean value of 1.7 mm. The present study concludes that the median–ulnar type of SPA was the most common type of SPA when the PMA was encountered as a source of superficial arterial arcade of the hand, followed by the radial–median–ulnar type. The vascular patterns found in this study are important to hand surgeons. The present study of PMA origin, course, and its contribution to the SPA will add to the existing knowledge of the vascular anatomy of forearm and hand.     

Fracture behaviour of zirconia FPDs substructures

Summary The purpose of this study was to evaluate the occurrence of superficial flaws after machining and to identify fracture initiation and propagation in three‐unit heat‐treated machined fixed partial dentures (FPDs) substructures made of hot isostatic pressed (HIPed) yttria‐stabilized tetragonal zirconia polycrystal (Y‐TZP) after loaded to fracture. Four three‐unit HIPed Y‐TZP‐based FPDs substructures were examined. To evaluate the occurrence of superficial flaws after machining, the surfaces were studied utilizing a fluorescent penetrant method. After static loading to fracture, characteristic fracture features on both mating halves of the fractured specimens were studied using a stereomicroscope and a scanning electron microscope. Grinding grooves were clearly visible on the surfaces of the machined FPDs substructures, but no other flaws could be seen with the fluorescent penetrant method. After loading to fracture, the characteristic fracture features of arrest lines, compression curl, fracture mirror, fracture origin, hackle and twist hackle were detected. These findings indicated that the decisive fracture was initiated at the gingival embrasure of the pontic in association with a grinding groove. Thus, in three‐unit heat‐treated machined HIPed Y‐TZP FPDs substructures, with the shape studied in this study, the gingival embrasure of the pontic seems to be a weak area providing a location for tensile stresses when they are occlusally loaded. In this area, fracture initiation may be located to a grinding groove.     

Carriage of Haemophilus influenzae and Streptococcus pneumoniae in healthy Chinese and Vietnamese children in Hong Kong

Nasopharyngeal carriage of Haemophilus influenzae and Streptococcus pneumoniae was studied in 621 healthy Chinese children and 300 healthy Vietnamese children aged from 2 months to 5 years in Hong Kong. The carriage rate of H, influenzae type b in Vietnamese children was 1.3% (CI 0.04-2.63%); it was zero in Chinese. The carriage rate of non-typable H. influenzae was 5.8% (CI 1.4-7.6%) in Chinese and 65.4% (CI 58.9-69.8%) in Vietnamese. The carriage rates of S. pneumoniae were 10.8% (CI 8.3-13.2%) and 55.7% (CI 50.1-61.3%) in Chinese and Vietnamese children, respectively. Univariate and multivariate logistic regression analyses were performed to search for factors associated with differences in carriage rates of both H. influenzae and S. pneumoniae between Chinese and Vietnamese children. Although older age, smaller living area and parental smoking were associated with higher carriage rates, these could not explain the remarkably low carriage rates of both bacteria in Chinese children.     

Genetic Engineering and Medical Ethics

In the introduction I express the need of introducing the point of view of Ethics when we are dealing with problems of science, technology, and especially medicine. In the first part of my presentation I deal with the problem of the value of human life, coming to the conclusion that human life might not be completely absolute, but is extremely important and “ceteris paribus” should be respected, and the problem of when it starts. Some of the main arguments are discussed. In this connection the question of abortion is briefly discussed. In the second part I deal with some problems related to human reproduction. Most people will be willing to support programmes for treating individuals with genetic disease; but at the same time the dangers of increasing depersonalization of the reproductive process are pointed out. In the third part I take up the problem of In Vitro Fertilisation. IVF has certainly brought benefits to some couples suffering from infertility, but at the same time it has raised quite a few human and moral problems. Is it permissible to fertilise an egg with a donor sperm, replacing the embryo in the womb? What about fertilising a donor egg with the husband's sperm? Is it acceptable to store or freeze embryos for future use? Is it moral to implant such an embryo in a woman who has no genetic relationship with the embryo? Is it moral to use surrogate mothers? Is it moral for ‘spare’ embryos to be killed or used as tissue for research? At the end I stress the need of dialogue between life sciences and ethics.     

The proteomics of ageing

Proteomics provides an extremely powerful tool for the study of variations in protein expression between individuals, different disease states and different conditions. One of the major challenges facing the medical profession in the forthcoming decades is to understand the changes that occur in individuals as they become older and to attempt to develop means to improve the quality of life for the otherwise healthy ageing population. The present study describes the first phase of such an investigation in which the andaged protein composition of human skeletal muscle sample from young and aged subjects are compared. These results provide the beginning of a Human Aged Skeletal Muscle Profile reference map which is an essential first step to further investigations. This revised version was published online in July 2006 with corrections to the Cover Date.     

贴报-P2临床毒理学、药理学和疗效研究

5-Flourouracil（5-FU） is one of well known anti-cancer drugs, but its toxicity in normal lymphocytes remains a major problem in chemotherapy. The eastern traditional drug, Bupleuri radix（BR）, has been used for the treatment of liver diseases and contains series of triterpene saponins.