2006年 · 第119卷第04期

Abstract：Background Nitric oxide (NO) is an important mediator in the pathophysiology of many vascular diseases. However, the definite role of NO in human abdominal aortic aneurysm (AAA) formation is unclear. The aim of this study was to investigate production of NO and expression of inducible nitric oxide synthase (iNOS), and their possible role in AAA.Methods A total of 28 patients with AAA, 10 healthy controls, and 8 patients with arterial occlusive disease were enrolled into this study. Standard colorimetric assay was used to examine NO concentration in plasma from patients with AAA and normal controls, and in cultured smooth muscle cells (SMCs). Expression of iNOS in aortas and cultured SMCs were detected by immunochemistry. The correlation of iNOS expression with age of the patient, size of aneurysm, and degree of inflammation was also investigated by Cochran-Mantel-Haenszelχ2 test and Kendall' Tau correlation.Results Expression of iNOS increased significantly in the wall of aneurism in the patients with AAA compared to the healthy controls (P<0.05) and the patients with occlusive arteries (P<0.05). iNOS protein and media NOx (nitrite+nitrate) also increased in cultured SMCs from human AAA (n=4, P<0.05), while plasma NOx decreased in patients with AAA (n=25) compared to the healthy controls (n=20). There was a positive correlation between iNOS protein and degree of inflammation in aneurismal wall (Kendall coefficient=0.5032, P=0.0029)Conclusions SMCs and inflammatory cells were main cellular sources of increased iNOS in AAA, and NO may play a part in pathogenesis in AAA through inflammation。

Abstract：Background It is very difficult and relatively unpredictable to preserve and restore severely weakened pulpless roots. To provide much needed benefit basis for clinical practice, this study was carried out to analyze the stress distribution in weakened roots restored with different cements in combination with titanium alloy posts. Finite element analysis (FEA) was employed in the study.Methods A pseudo three-dimensional model of a maxillary central incisor with flared root canal, theoretically restored with titanium alloy posts in combination with different cements, was established. The analysis was performed by use of ANSYS software. The tooth was assumed to be isotropic, homogenous and elastic. A load of 100 N at an angle of 45°to the longitudinal axis was applied at the palatal surface of the crown. The distributions of stresses in weakened roots filled with cements of different elastic modulus were analyzed by the three-dimensional FEA model.Results Several stress trends were observed when the stress cloud atlas obtained in the study was analyzed. With the increase of the elastic modulus of cements from 1.8 GPa to 22.4 GPa, the stress values in dentin decreased from 39.58 MPa to 31.43 MPa and from 24.51 MPa to 20.76 MPa (respectively, for maximum principle stress values and Von Mises stress values). When Panavia F and zinc phosphate cement were used, the stress peak values in dentin were very small with no significant difference observed, and the Von Mises stress values were 20.87 MPa and 20.76 MPa respectively. On the other hand, maximum principle stress value and Von Mises stress value in cement layer increased with the increase of the elastic modulus of cements.Conclusions The result of this study demonstrated that elastic modulus was indeed one of the important parameters to evaluate property of the cements. Our three-dimensional FEA model study also found that the cement with elastic modulus similar to that of dentin could reinforce weakened root and reduce the stress in dentin. Thus, it may be a better choice for the restoration of weakened roots in clinical practice。

Abstract：Background Placement of an external support has been reported to prevent intimal hyperplasia of vein grafts. However, it is limited by potential complications. In the present study, we investigated the effect of fibrin glue on preventing vein graft failure as perivenous application. Methods Twenty-four rabbits were divided into non-supported group (n=12) and fibrin glue group (n=12). All animals underwent unilateral jugular vein into common carotid artery interposition grafting and then fibrin glue was applied as perivenous support. Samples of tissues were harvested after 4 weeks. Results The vein grafts with fibrin glue demonstrated a statistically significant decrease in proliferating cell nuclear antigen in the medial/intimal region [13.38% (11.26%－15.11%)] compared with non-supported vein grafts [31.22% (27.15%－35.98%)] (P<0.001). Light microscopy showed remarkable attenuation of endothelial cell loss and numerous microvessels in neoadventitia in the fibrin glue group compared with the non-supported group. The smooth muscle cells migrated into adventitia significantly in fibrin glue group, whereas the smooth muscle cells migrated into intima in non-supported group.Conclusion Perivenous support of vein graft with fibrin glue in vivo can attenuate the severe injury encountered in the non-supported vein grafts exposed to artery。

Abstract：Background There were some papers published in the Jonrnal of Science, December 2000 suggesting that one or more important susceptibility genes for late onset Alzheimer's disease (LOAD) were located on the long arm of chromosome 10. Linkage analysis showed maximum lod score close to D10S1225 loci, which indicated the loci might contribute to the etiology of Alzheimer's disease (AD). Methods Fifty-nine LOAD patients and 107 controls were recruited. Apolipoprotein E (ApoE) genotypes were determined by reverse dot blotting hybridization assay. The D10S1225 was genotyped by 12% nondenaturing polyacrylamide gels electrophoresis and analyzed by silver staining. Statistical analysis was used to compare genotype and allele distributions between LOAD group and control group for ApoE and D10S1225 polymorphisms.Results ApoE ε4 was significantly higher in LOAD group in comparison with the control group(χ2=6.530, P =0.011). Seven different alleles of D10S1225 have been identified. The length of these gene fragments were 178 bp, 181 bp, 184 bp, 187 bp, 190 bp, 193 bp, and 196 bp, respectively. A total of 21 different genotypes were observed. There was no relationship between D10S1225 polymorphism and LOAD (χ2=4.488, P>0.05). Conclusion This study suggests that ApoEε4 is a risk factor for LOAD, however, the results indicated that there is not any possible linkage for disequilibria with a nearby AD risk gene near D10S1225。

Abstract：Background Elevated levels of interleukin-7 (IL-7) have been correlated with CD4+ T cell depletion and the emergence of syncytium-inducing (SI) variants in human immunodeficiency virus type-1 (HIV-1) infection, and suggested as an indicator of acquired immunodeficiency syndrome (AIDS) disease progression. Therefore, we investigated the effects of IL-7 on disease progression and virus phenotype in Chinese HIV/AIDS patients. Methods In a cross-sectional study of 71 untreated HIV-1 seropositive individuals and 12 healthy donors, plasma IL-7 levels were determined by an ultra sensitive enzyme-linked immunosorbent assay (ELISA),and its relations to CD4+ T cells, CD8+ T cells, plasma viral loads and HIV phenotypes were analyzed. Results Significant higher IL-7 levels were found in Chinese HIV/AIDS patients [(3.33±3.60) pg/ml] than those of health controls [(1.2±0.81) pg/ml] (P<0.05), and IL-7 levels were inversely associated with CD4+ T cell counts (r=-0.497, P<0.01). Furthermore, IL-7 levels were significant higher in patients with SI variants [(9.12±4.55) pg/ml] than those with non-syncytium-inducing variants [(1.50±2.69) pg/ml] (P<0.01). Conclusions Increased IL-7 levels were found in Chinese HIV/AIDS patients and significantly associated with disease progression, thus increased IL-7 plasma levels may indicate disease progression。

Abstract：Background Nitic oxide (NO) has been implicated in the pathogenesis of various inflammatory diseases, including sunburn and pigmentation induced by ultraviolet irradiation. Epigallocatechin-3-gallate (EGCG) is the major effective component in green tea and can protect skin from ultraviolet-induced damage. The purpose of this study was to investigate the protective mechanisms of EGCG on inducible nitric oxide synthase (iNOS) expression and NO generation by ultraviolet B (UVB) irradiation in HaCaT cells.Methods HaCaT cells were irradiated with UVB 30 mJ/cm2 and pretreated with EGCG at varying concentrations. The iNOS mRNA was detected by reverse transcriptase polymerase chain reaction (RT-PCR) and NO production was quantified by spectrophotometric method. The expression of NF-κB P65 was measured by immunofluorescence cytochemistry staining. Results The expression of iNOS mRNA and generation of NO in HaCaT cells were increased by UVB irradiation. EGCG down regulated the UVB-induced iNOS mRNA synthesis and NO generation in a dose dependent manner. The UVB-induced activation and translocation of NF-κB were also down regulated by EGCG treatment in HaCaT cells (P<0.01).Conclusions Green tea derived-EGCG can inhibit and down regulate the UVB-induced activation and translocation of NF-κB, expression of iNOS mRNA and generation of NO respectively, indicating EGCG may play a protective role from UVB-induced skin damage。

Abstract：Background Our previous research has suggested that genes around D12S1056 in 12q13 may confer susceptibility to ventricular septal defect (VSD) in humans. The present study was to define the chromosome region assignment by transmission disequilibrium test (TDT), and to identify the important candidate gene by family-based association study and haplotype analysis. Methods Surrounding D12S1056, ten microsatellite markers including D12S329, D12S305, D12S1662, D12S1056, D12S1293, D12S334, D12S102, D12S83, D12S1655 and D12S1691 were chosen, and TDT was performed in 62 nuclear family trios each consisting of an affected child and two healty parents. Subsequently, the GLI gene, a positional candidate gene that maps to the target region, was selected for further analysis. Three single nucleotide polymorphisms (SNPs), G11888C, G11388A, and G11625T, were selected for family-based association study and haplotype analysis. Results VSD was significantly associated with all selected markers except D12S1691 [72.2 centi morgen (cM)] and D12S1700 (75.76 cM). VSD was also significantly associated with G11888C (χ2 = 5.918, P = 0.015), G11388A (χ2 = 8.067, P = 0.005), and G11625T (χ2 = 11.842, P = 0.001). Haplotype analysis showed a strong linkage disequilibrium between G11888C and G11388A (D'=0.999), but in significant (χ2 = 1.035, df = 2, P >0.05). Conclusions The susceptibility gene of VSD was mapped to 3.56 cM in 12q13 by TDT, and the GLI gene, an important candidate in the target region, was associated with VSD。

Abstract：Background Dermal papilla cells (DPC) are a group of mesenchyme-derived cells at the base of the hair follicle, where they regulate and control hair follicle growth through the expression and secretion of cytokines. Nevertheless, the role of DPC derived chemokines and other cytokines in the hair follicle biology remain speculative. In this study, we investigated the expression of basic fibroblast growth factor (bFGF), endothelin-1 (ET-1) and stem cell factor (SCF) in different passages of cultured DPC and their effects on the biological behaviour of DPC.Methods The expression of bFGF, ET-1 and SCF in different passages of cultured DPC and their possible effects on the biological behavior of DPC are investigated using in situ hybridization and immunochemistry. In addition, we performed transplantation of hair follicle cells into nude mice. The cultured DPC, dermal sheath cells and fibroblast of human scalp, respectively, were mixed with cells of the hair follicle epithelium in different ratios, and then were cultured in hair follicle organotypic cultures or implanted into the subcutis of nude mice.Results The expression of ET-1 and SCF in early passages of cultured DPC became stronger, but turned weaker and even negative in late passages (>6 passages). Hair follicle-like structures were formed after DPC combined with the cells of hair follicle epithelium cells in hair follicle organotypic cultures. When hair follicle organotypic cultures were implanted into the subcutis of nude mice, the relative intact hair follicles were formed. After the transplantation of hair follicle cells into the nude mice, the hair follicle-like structure was formed in the group that contained DPC mixed with hair follicle epithelium cells. However, no hair follicles were formed in the other two groups. It was found that the higher the expression of ET-1 and SCF in DPC, the stronger the ability of DPC to induce hair follicle regeneration.Conclusions The cultured DPC can induce hair follicle regeneration and sustain hair growth in vivo and in vitro. Moreover, the expression of ET-1 and SCF is correlated with the ability of DPC inducing hair follicle regeneration。

Atrial electrophysiological heterogeneity, which plays an important role in the genesis and maintenance of atrial arrhythmia, is a major determinant of atrial reentrant arrhythmias. Recently, many studies on atrial flutter have demonstrated the anatomic architecture in the right atrium plays an important role in the genesis of atrial reentry.1 The crista terminalis (CT) in the right atrium, which is a unique anatomic structure of the right atrium, provides an area for conduction block and delay, leading to initiation, maintenance, and termination of atrial arrhythmias。

Mucinous cystic neoplasms (MCNs) of the pancreas are a distinct entity, account for 1% of pancreatic exocrine tumors. MCNs can be classified histologically as adenomas, borderline tumors, or carcinomas. Because several evidences showing that mucinous cystadenomas are poten- tially malignant and may transform into cystadeno- carcinomas, particularly if treated by drainage, these tumors should be identified accurately.1

Bone morphogenetic proteins (BMPs) induce ectopic bone formation and promote osteoblast differentiation.1 It has been documented that Smad transcriptional factors function as primary mediators of BMPs activity. Receptor-regulated Smad (Smad1, 5, 8) could be phosphorylated by activated BMPR-I and form complex with Smad4. The Smad complex translocates to the nucleus and regulate target gene transcription.2

Arole for inflammation has become well established over the past decade or more in theories describing the atherosclerotic disease process.1,2 From a pathological viewpoint, all stages, ie, initiation, growth, and complication of the atherosclerotic plaque,3,4 might be considered to be an inflammatory response to injury. Several prospective studies 5-7 recently showed that plasma high sensitivity C-reactive protein (hsCRP) levels, which are one of the markers of systemic inflammation, are a powerful predictor of future myocardial infarction and cardiac death among apparently healthy individuals. However, the association between the plasma hsCRP levels and the extent of coronary stenosis in subjects remains controversial. Some studies previously demon- strated such associations,8,9 whereas other could not found.10,11 Gensini's score assigns a severity score for a stenosed vessel depending on the degree of luminal narrowing and the importance of its location.12

Brucella abortus is a gram-negative, facultative, intracellular bacterium that infects both cattle and humans, causing abortion and infertility in the former and undulant fever, endocarditis, arthritis, and osteomyelitis. Resistance to Brucella depends on acquired cell-mediated immunity (CMI).1 Live attenuated vaccines can stimulate strong CMI response, which are usually very effective against brucellosis and are used to control brucellosis in domestic animals. However, there is no safe and effective vaccine available for human because the vaccine strains used for animals are considered too virulent for humans. A vaccine that will be noninfectious to humans but effective in stimulating a broad protective immune response is needed.2

Penetrating wound of the anal canal is relatively rare, which is often complicated with injuries of the rectum, urinary bladder or posterior urethra. Misdiagnosis and improper treatments of the disease may lead to pelvic abscess, anal stenosis, fecal incontinence, or rectovesical fistula. From 1985 to 2004, 16 patients with penetrating wounds through the anorectum and urinary bladder or posterior urethra were treated in our hospital。

Acute aortic occlusion is an infrequent but dangerous vascular emergency with a mortality rate of 50%,1 resulting from aortic saddle embolus, thrombosis of an atherosclerotic abdominal aorta, or sudden thrombosis of a small abdominal aortic aneurysm。

It has been reported that positive remodeling, regression of neointimal hyperplasia, and late malapposition are associated with brachytherapy, one of the approaches to prevent first-time and recurrent in-stent restenosis.1,2 Recently, some drug-eluting stents have been demonstrated to dramatically reduce restenosis rates.3,4 Despite these promising results, these drug-eluting stents may have the same potential risks as brachytherapy, with some similarities between the 2 technologies in anti- proliferative effects on vascular smooth muscle cells and endothelial cells. We reported a case of late stent malapposition and marked positive vessel remodeling after sirolimus-eluting coronary stent implantation。

Endoscopic vein harvesting (EVH) for coronary artery bypass grafting (CABG) has gained increasing acceptance as a less invasive alternative to conventional open vein harvesting. With this procedure, carbon dioxide (CO2) is insufflated to create a subcutaneous tunnel to facilitate the harvest of the great saphenous vein. The technique seems to be safe because there are no adverse hemodynamic consequences or systemic CO2 absorption during EVH.1,2 We report a case of massive right heart gas embolism which occurred during a routine EVH performance of the saphenous vein。

To the Editor : I read with interest the case report by Shen et al1 of transcatheter treatment of Lutembacher syndrome. Lutembacher syndrome refers to a congenital atrial septal defect (ASD) complicated by acquired mitral stenosis (MS).2 The incidence of MS in patients with ASD is 4%, the incidence of ASD in patients with MS is 0.6%-0.7%.2 Lutembacher syndrome in the past has been overdiagnosed or misdiagnosed because of the presence of a mid-diastolic murmur in patients with ASD, until it was realized that the mid-diastolic murmur was due to excessive flow through the tricuspid valve from the left-to-right interatrial shunt。