Rh phenotypes of Chinese blood donors in Hong Kong, with special reference to weak D antigens

Among Hong Kong Chinese blood donors, 99.71 percent were found to be D+. Of these, 55.02 percent were of the phenotype CCDee. The Du phenotype was found to be present in 0.016 percent. Among the 0.27 percent who were apparently D-, 0.079 percent were of the Del phenotype, while the remaining 0.19 percent were "true D-," as defined by a nonreactive eluate obtained by an adsorption and elution procedure using anti-D. The ccdee phenotype constitutes 56.77 percent of the "apparent D-" and 80.24 percent of the true D-. Data show that anti-D rarely occurs in Hong Kong Chinese, and it is postulated that this could be due to the presence of a very weak form of the D antigen among many of those who appear to be D-.     

Cardiovascular disease and mortality in statin-treated patients with familial hypercholesterolemia

Patients with familial hypercholesterolemia (FH) are at an increased risk of premature cardiovascular disease (CVD). The benefits of statin therapy are not well known since no placebo controlled studies have been performed in these patients. The aim of this study was to determine the CVD event and mortality risk in statin-treated patients with FH. A total of 345 FH patients were followed prospectively for 8 years. Mortality from CVD was compared to that of the general population. The absolute risk of CVD in patients without a previous history of CVD was 3% per year for men and 1.6% for women. Mortality from CVD in patients without a previous history was 1.4-fold (95% CI = 0.6-3.3) increased and ischaemic heart disease (IHD) mortality was 2.6-fold (95% CI = 1.1-6.3) higher compared to the general population. This mortality risk was highest in patients aged 40-59 years. Female FH patients had no increased CVD or IHD mortality risk. Over a period of 8 years the event risk of patients with a history of CVD was almost 30% per year under age 40 years and 15% in patients aged 60 years and over. When compared to the general population, mortality from other causes than CVD was lower for patients with FH, the relative risks not reaching statistical significance. The relative risk of mortality from all causes was 1.5 (P < 0.05) for men and 1.0 for women. In conclusion, male patients with FH, treated from middle-age with statins remain at an increased risk of developing CVD.     

Effects of Very Long Chain Versus Long Chain Triglycerides on Gastrointestinal Motility and Hormone Release in Humans

Fish oil (a very long chain triglycerides, VLCT) has received much attention because of its favorable metabolic properties; however, its effect on gastrointestinal function has not been studied. We investigated the effects of intraduodenally administered VLCT on gut-hormone release [cholecystokinin (CCK), neurotensin, peptide YY (PYY)], gallbladder emptying, antroduodenal motility, and small bowel transit time (SBTT) in comparison to intraduodenal administration of saline and long chain triglycerides (LCT, corn oil) in nine healthy volunteers. Gallbladder contraction duration was significantly shorter after VLCT than after LCT (138 ± 16 min vs 233 ± 38 min, P < 0.05). Both fats induced a fed motility pattern, while SBTT was not significantly altered. CCK secretion was significantly reduced after VLCT compared to LCT (36 ± 12 pM × 120 min vs 78 ± 15 pM × 120 min, P < 0.05), whereas PYY and neurotensin release were not significantly different. In conclusion, effects of triglycerides on CCK and gallbladder motility appear to be chain-length dependent, in contrast to the effects on distal gut-hormone release and intestinal motility and transit, which appear to be chain-length independent.     

Murine thymocytes proliferate in direct response to interleukin-7

The ability of interleukin-7 (IL-7) to stimulate murine thymocyte proliferation was investigated. IL-7, either alone or in concert with lectin, induced proliferation of adult thymocytes as well as day 13 fetal and adult CD4-/CD8-thymocytes. The IL-7-induced proliferative response of unfractionated thymocytes could not be inhibited by antibodies to IL-2, or IL-4, IL-6, or the IL-2 receptor. In addition, IL-2, IL-4, and IL-6 were not produced by thymocytes activated with IL- 7, as judged by the absence of biologically active cytokine in IL-7- stimulated culture supernatants. IL-7 could act in concert with IL-2 and IL-4 or with IL-4 to enhance the proliferative response of thymocyte cultures. Thus, IL-7 may cause proliferation of thymocytes directly, not indirectly, through production of IL-2, IL-4, or IL-6. IL- 7 may then play a significant role in differentiation of T lymphocytes.     

Targeted insertions of two exogenous collagen genes into both alleles of their endogenous loci in cultured human cells: the insertions are directed by relatively short fragments containing the promoters and the 5'' ends of the genes.

Previous studies demonstrated that type II procollagen is synthesized by HT-1080 cells that are stably transfected with constructs of the human COL2A1 gene that contain the promoter and 5' end of either the COL2A1 gene or the human COL1A1 gene. Since the host HT-1080 cells were from a human tumor line that synthesizes type IV collagen but not type II or type I procollagen, the results suggested that the constructs were integrated near active enhancers or promoters. Here, however, we demonstrate that a 33-kb construct of the COL2A1 gene containing a 5' fragment from the same gene was inserted into both alleles of the endogenous COL2A1 gene on chromosome 12, apparently by homologous recombination by a nonconservative pathway. In contrast, a similar construct of the COL2A1 gene in which the 5' end was replaced with a 1.9-kb fragment from the 5' end of the COL1A1 gene was inserted into both alleles of the locus for the COL1A1 gene on chromosome 17. Therefore, targeted insertion of the gene construct was not directed by the degree of sequence homology. Instead, it was directed by the relatively short 5' fragment from the COL1A1 gene that contained the promoter and the initially transcribed sequences of the gene. After insertion, both gene constructs were expressed from previously inactive loci.     

皮肤软组织扩张术在颌面部的应用

０　引言　近年来，由于皮肤软组织扩张术的种种优点并随着此项技术的逐渐推广应用，很多医疗单位已将此种方法做为颌面部瘢痕、斑痣、血管瘤及外伤性纹身的首选修复方法．但由于颌面部对术后效果有着较高的美容要求，如何更合理地应用扩张术以达到更好的修复效果，无疑是...     

Role of CD56-expressing immature biliary epithelial cells in biliary atresia

AIM: To analyze the clinical and pathological parameters and expression of the neural cell adhesion molecule(CD56) in patients with biliary atresia(BA).METHODS: Established clinical laboratory markers of hepatic function, including enzyme activity, protein synthesis, and bilirubin metabolism, were evaluated in patients with BA and compared with those in patients with choledochal cysts and neonatal hepatitis. Pathological changes in tissue morphology and fibrosis were examined by histological and tissue collagen staining. Immunohistochemical staining for the biliary epithelial cell markers CD56 and CK19 together with the Notch signaling related molecules Notch1 and Notch2 was performed in the context of alterations in the structure of intrahepatic biliary ducts.RESULTS: Differences in some clinical laboratoryparameters among the three diseases examined were observed, but they did not correlate with the pathological classification of fibrosis in BA. Immunohistochemical staining showed the presence of CD56-positive immature bile ducts in most patients(74.5%) with BA but not in patients with choledochal cysts or neonatal hepatitis. The number of CD56-expressing cells correlated with disease severity, with more positive cells present in the later stages of liver damage(81.8% vs 18.2%). Furthermore, bile plugs were mainly found in CD56-positive immature biliary ducts. Notch signaling was a key regulatory pathway in biliary duct formation and played a role in tissue fibrosis. Notch1 was co-expressed in CD56-positive cells, whereas Notch2 was found exclusively in blood vessels in the portal area of patients with BA. CONCLUSION: The maturation of biliary epithelial cells and the expression of Notch may play a role in the pathogenesis of BA.