Volume 120  ·   Issue 05  ·  2007

Abstract：Background Recent studies have suggested that mature T cells can change their specificity through reexpression of recombination-activating genes (RAG) and RAG-mediated V(D)J recombination. This process is named receptor revision and has been observed in mature peripheral T cells from transgenic mice and human donors. However, whether the receptor revision in mature T cells is a random or orientated process remains poorly understood. Here we used the Jurkat human T cell line, which represents a mature stage of T cell development, as a model to investigate the regulation of T cell receptor (TCR) gene recombination.Methods TCR Dβ-Jβ signal joint T cell receptor excision DNA circles (sjTRECs) were determined by nested and seminested PCR. Double-strand DNA breaks at recombination signal sequences (RSSs) in the TCRVβ chain locus were detected by ligation-mediated-PCR. Further analysis of the complementarity-determining region 3 (CDR3) size of the TCRVβ chain was examined by the TCR GeneScan technique.Results RAG1, RAG2, and three crucial components of the nonhomologous DNA end-joining (NHEJ) pathway were readily detected in Jurkat. Characteristics of junctional diversity of Dβ2-Jβ2 signal joints and ds RSS breaks associated with the Dβ25' and Dβ 23' sites were detected in DNA from Jurkat cells. CDR3 size and the gene sequences of the TCRVβ chain did not change during cell proliferation.Conclusions RAG1 and RAG2 and ongoing TCR gene recombination are coexpressed in Jurkat cells, but the ongoing recombination process may not play a role in modification of the TCR repertoire. However, the results suggest that Jurkat could be used as a model for studying the regulation of RAGs and V(D)J recombination and as a "special" model of the coexistence of TCR gene rearrangements and "negative" receptor revision。

Abstract：Background Both p16INK4 and p21Waf1 are tumor suppressors with similar biological functions in the regulation of cellular senescence. Previous reports showed that p16INK4 could be activated by p21Waf1 through transcriptional factor Sp1 in HeLa cells. This study was undertaken to determine the effects of p16INK4 on the expression and functions of p21Waf1.Methods Human diploid fibroblast 2BS cells were stably transfected with sense (2BS/p16INK4), antisense p16INK4(2BS/asp16INK4) or empty vector (2BS/neo) .Then they were assayed by reverse-transcription polymerase chain reaction (RT-PCR), fluorescence activated cell sorting (FACS) and Western blot.Results 2BS/p16INK4 cells exhibited cell cycle arrest in both G1 and G2/M phases. Endogenous p21Waf1 protein levels increased twofold in the 2BS/p16INK4 cells, but not decreased in the 2BS/asp16INK4 cells. p21Waf1 mRNA levels were not affected in neither 2BS/p16INK4 nor 2BS/asp16INK4 cells.Conclusion p16INK4 may play an important role in the regulation of cellular senescence by modulating the p21Waf1protein level via the posttranscriptional mechanism。

Abstract：Background Osteosarcoma is one of the most common primary malignant tumors of bone with poor prognosis.TNF-related apoptosis inducing ligand (TRAIL) is a member of the tumor necrosis factor (TNF) cytokine family. TRAIL induces apoptosis in various tumor cell lines but is not found to be cytotoxic to many normal cell types in vitro. We investigated the cytotoxic activity of TRAIL and chemotherapeutic agents, including methotrexate (MTX), doxorubicin(DOX) and cisplatin (CDDP), on established osteosarcoma cell line-OS-732.Methods OS-732 cells were incubated with chemotherapeutic agents MTX,DOX and CDDP at various peak plasma concentrations(PPC), 0.1PPC,1PPC and 10PPC, alone or with 100 ng/ml of TRAIL for 24 hours or 48 hours. MTT was used to evaluate the cytotoxic activity of different agents on OS-732. The apoptosis proportion was assayed by flow cytometry. Cellular morphologic changes were observed by phase contrast microscope, scan electron microscope, and transmission electron microscope.Results The inhibitory rate was (24.438±3.414)% with TRAIL of 100 ng/ml for 24 hours. The cells were responsive to DOX and CDDP with a dose-effect relationship (P＜0.05). In OS-732 cells, DOX and CDDP cooperated synergistically with TRAIL when incubated the cells with them for 24 hours (the combined inhibitory rate is (58.360±2.146)% and (54.101 ±2.721)%, respectively). TRAIL alone or drugs alone induced the apoptosis rate was less than 25% (P＜0.05).However, the combination of TRAIL and MTX did not present synergistic effects on OS-732 cells (P＞0.05, compared with TRAIL alone).Conclusions Osteosarcoma OS-732 cells were not responsive to TRAIL-induced apoptosis. DOX and CDDP sensitize osteosarcoma OS-732 cells to TRAIL-induced apoptosis. The combination of TRAIL and MTX presented no synergistic effects on killing OS-732 cells。

Abstract：Background Preconditioning with repeated electroacupuncture (EA) could mimic ischemic preconditioning to induce cerebral ischemic tolerance in rats. The present study was designed to investigate whether mu(μ)-, delta(δ)- or kappa(κ)-opioid receptors are involved in the neuroprotection induced by repeated EA preconditioning.Methods The rats were pretreated with naltrindole (NTI), nor-binaltorphimine (nor-BNI) or D-Phe-Cys-Tyr-D-Trp-Orn-Thr-Pen-Thr-NH2 (CTOP), which is a highly selective δ-, κ- or μ-opioid receptor antagonist respectively, before each EA preconditioning (30 minutes per day, 5 days). Twenty-four hours after the last EA treatment, the middle cerebral artery occlusion (MCAO) was induced for 120 minutes. The brain infarct volume was determined with 2,3,5-triphenyltetrazolium chloride staining at 24 hours after MCAO and compared with that in rats which only received EA preconditioning. In another experiment, the met-enkephalin-like immunoreactivity in rat brain was investigated by immunohistochemistry in both EA preconditioning and control rats.Results The EA preconditioning reduced brain infarct volume compared with the control rats (P=0.000). Administration of both NTI and CTOP attenuated the brain infarct volume reduction induced by EA preconditioning, presenting with larger infarct volume than that in the EA preconditioning rats (P＜0.001). But nor-BNI administration did not block the infarct volume reduction induced by EA preconditioning, presenting with smaller infarct volume than the control group rats(P=0.000). The number of met-enkephalin-like immunoreactivity positive neurons in the EA preconditioning rats was more than that of the control rats (P=0.000).Conclusion Repeated EA preconditioning stimulates the release of enkephalins, which may bind δ- and μ-opioid receptors to induce the tolerance against focal cerebral ischemia。

Abstract：Background Hypertension is a common disease of the cardiovascular system. So far, the pathogenesis of primary hypertension remains unclear. The elaboration of its pathogenesis is an important topic in the field which calls for urgent resolution. The aim of this study was to probe into the metabolic imbalance of homocysteine (Hcy) and hydrogen sulfide(H2S) in children with essential hypertension, and its significance in the pathogenesis of essential hypertension.Methods Twenty-five children with essential hypertension and 30 healthy children with normal blood pressure were enrolled in the study. The medical history was investigated and a physical examination was conducted on the subjects.Plasma Hcy content was examined by fluorescence polarization immunoassay (FPIA). The plasma H2S level was detected by a modified method with a sulfide electrode. Data were presented as mean±standard deviation. The t test was applied to the mean values of both groups. Pearson linear correlation analysis was applied to the plasma Hcy and H2S as well as to the systolic pressure against the plasma H2S/Hcy ratio.Results Plasma Hcy, an intermittent metabolite of the endogenous methionine pathway, was markedly increased but plasma H2S, a final product of this pathway was significantly decreased in hypertensive cases when compared with normal subjects ((Hcy: (12.68±9.69) μmol/L vs (6.62±4.79) μmol/L (t=2.996, P＜0.01); H2S: (51.93±6.01) μmol/L vs(65.70±5.50) μmol/L) (t=-8.670, P＜0.01)). The ratio of plasma H2S/Hcy in children with hypertension was 5.83±2.91,while that of the control group was 11.60±3.30, and the difference is significant with a t=-6.610 and P＜0.01. A negative correlation existed between plasma Hcy and H2S concentrations, r=-0.379, P＜0.05. And a negative correlation was found between systolic blood pressure and the plasma H2S/Hcy ratio, r=-0.687, P＜0.05.Conclusion There was a metabolic imbalance of homocysteine and hydrogen sulfide in essential hypertensive children。

Abstract：Background In the past decade, there has been increasing breast reconstructions after mastectomy. The ideal material for reconstruction of a breast is fat and skin. The transverse rectus abdominis myocutaneous (TRAM) flap has been the gold standard for breast reconstruction until recently. Abdominal wall function is a major concern for plastic surgeons in breast reconstruction with TRAM flaps. The deep inferior epigastric perforator (DIEP) free flap spares the whole rectus abdominis muscle, includes skin and fat only, and therefore preserves adequate abdominal wall competence. The aim of this study was to summarize our experience in breast reconstruction with DIEP flap.Methods Between March 2000 and August 2005, a total of 43 breast reconstructions were performed on 40 patients by our surgeons using DIEP flap (3 patients had bilateral procedures), 14 of them were immediate surgeries and 26 were delayed. Abdominal function, satisfaction with the donor site and reconstructed breast, and the sensation recovery was assessed respectively during follow-up.Results The mean age of the patients was 38.6 years (range, 28-50). The size of the flaps was 11 cm×26 cm in average (height 10-12 cm, width 15-33 cm). The mean length of the vascular pedicles was 9.3 cm (range, 7-12). The patients were followed up for a mean of 16 months (range, 6-30 months). During the follow-up, 2 (5%) patients had total flap loss, 2 (5%) had partial necrosis, 4 (9%) had wound edge necrosis in the abdomen, and 1 had axillary seroma. None of the patients had hernia, and all of them were able to resume their daily activities after the operation. Patient satisfaction with the reconstructed breast rated high, 95% of the patients achieved spontaneous return of sensation in the reconstructed breast, but none of them had a sensation equivalent or approximate to the normal.Conclusions The DIEP flap has the same benefits as the TRAM flap without destroying the continuity of the rectus muscle. It can reduce donor-site morbidity and provide an aesthetic refinement in breast reconstruction。

Abstract：Background Fascin, an actin binding protein, usually expressed at a low level in normal epithelium, but is significantly increased in transformed epithelial cells and several common carcinomas. In this study, we examined the expression of fascin by immunohistochemistry in sinonasal epithelium with chronic inflammation (control group), exophytic papilloma(EP), inverted papilloma (IP) with dysplasia and cancerated IP (including carcinoma in situ and invasive squamous cell carcinoma, SCC), and furthermore investigated the relationship between fascin expression and formation of malignant IP.Methods Fascin expression was immunohistochemically detected using monoclonal antibody against fascin in 86paraffin embedded tissues, including 10 cases of sinonasal mucosa with chronic inflammation, 10 of EP, 45 of IP with dysplasia (45 cases were divided into three groups: IP with mild dysplasia, IP with moderate dysplasia, and IP with severe dysplasia, 15 cases each), and 21 of cancerated IP.Results The level of fascin expression was significantly higher in the neoplastic tissue than that in control group. Fascin expression increased gradually with the progression from sinonasal epithelium with chronic inflammation, IP with mild dysplasia, IP with moderate dysplasia, IP with severe dysplasia, to cancerated IP, and significant difference of fascin expression was observed between any two groups of the five.Conclusion Precancerous lesions of IP exhibit elevated levels of fascin that may be associated with carcinogenesis of IP. Fascin may play a role in the formation of IP and EP。

Abstract：Background The primary objectives of the treatment for the lower urinary tract symptoms (LUTS) associated with benign prostatic hyperplasia (BPH) are to produce rapid, sustained, and safe improvements in the symptoms that affect the quality of life in the majority of men over 50. In this study, we evaluated the efficacy and safety of the combined therapy with terazosin (α1-adrenergic receptor antagonist) and tolterodine (anticholinergic agent) for LUTS associated with BPH.Methods This combination study included 69 patients diagnosed with LUTS associated with BPH based on the International Prostate Symptom Scores (IPSS), urinary flow rate, prostate volume, urinary residual, and their serum prostate-specific antigen levels. Initially, 191 patients were treated with terazosin 2 mg once daily for one week. Those patients with continued LUTS after the initial treatment were allocated randomly into two groups: terazosin group (n=36)in which patients were treated with terazosin 2 mg once daily for six weeks, and combination group (n=33) in which patients were treated with both terazosin 2 mg once daily and tolterodine 2 mg twice daily for 6 weeks.Results The IPSS were significantly improved in both groups after treatment, and the reduction of IPSS in the combination group was significantly greater than that in the terazosin group (P＜0.01). A decrease in urgency, frequency and nocturia were the main contributory factors causing the reduction of IPSS in the combination group. The differences about the peak urinary flow rate and the residual urine from the baseline values were noted in both groups after treatment,but were not significant between the two groups. The incidence of adverse effects in the combination group was higher than that in the terazosin group. As expected the most common adverse effect was mouth dryness which was associated with anticholinergic drugs such as tolterodine.Conclusions Patients with LUTS associated BPH appear the improved IPSS after combined therapy with terazosin and tolterodine. This study, although short term and limited numbers of patients, provides evidence that the combined therapy with terazosin plus tolterodine is a good approach for meeting the objectives of rapid, sustained, and safe improvements in the LUTS associated with BPH. And the profile of patients in this study might be used as the indication of such combined therapy for LUTS associated with BPH without urodynamic evaluation。

Abstract：Background Myofibroblastic sarcoma was used to be a controversial neoplasm. This study investigated the clinicopathological features of 20 cases of myofibroblastic sarcoma arising in different locations.Methods The paraffin-embedded tissue samples from 20 cases of patients with myofibroblastic sarcoma were stained immunohistochemically, and 5 cases examined by electron microscopy. Student's t test was used to analyze the difference of Ki-67 labeling index between grade 1 and grade 2 myofibroblastic sarcomas.Results Histologically, the tumors were composed of slender spindle cells with eosinophilic cytoplasm, and fusiform,tapering, wavy, or plump ovoid; vesicular nuclei and a small central eosinophilic nucleoli. Immunohistochemically, the tumor cells expressed smooth muscle actin (18/20), muscle specific actin (16/20), fibronectin (20/20) and desmin (2/20).Ultrastructurally, the tumor cells revealed abundant rough endoplasmic reticulum and longitudinally arranged fine filaments with focal densities in the cytoplasm. A clinical follow-up of 19 patients showed that 2 cases experienced local recurrence and distant metastasis 6 months to 4 years after the initial operation. Nine cases recurred locally 17 to 46 months after the initial excision, and 9 cases were alive with no evidence of disease.Conclusions Myofibroblastic sarcomas, which exhibit diverse histological appearance, can easily be misdiagnosed as benign tumors. Myofibroblastic sarcomas are local destructive lesions with frequent recurrence, and may metastase distantly。

Abstract：Background Atherosclerosis as a cardiovascular disease was found to begin even in the fetal period. However,information about risk factors of pre-clinical atherosclerosis in childhood has been limited. Hence, this study was aimed to find out the risk factors of atherosclerosis by measuring the carotid artery intima-media thickness in children. High resolution B-mode ultrasound used to examine the carotid artery intima-media thickness was demonstrated to be useful in finding the early carotid structural changes.Methods The study included 79 children who were divided into two groups according to their ages: group Ⅰ consisted of 42 children with ages from 5 to 9 years and group Ⅱ consisted of 37 children with ages from 10 to 18 years, Among them,23 had a positive family history for risk, such as hypertension, obesity or dyslipidemia. Blood samples were collected and total cholesterol, triglycerides, high density lipoprotein and low density lipoprotein were assayed. The carotid artery intima-media thickness was measured by ultrasound. Comparisons were done between the two groups using Student's t tests and Chi-square analysis. Body mass index, blood pressure, levels of lipids, family history and the carotid artery intima-media thickness were calculated by conditional logistic regression analysis.Results Compared with the children without a positive family history, the incidence of the increased carotid artery intima-media thickness was significantly high (x2=4.364, P＜0.05). There were no statistically significant differences between left and right carotid arteries in carotid artery intima-media thickness (P＞0.05). In this study, diastolic blood pressure and the atherosclerosis index were suggested to be the risk factors to the thickened carotid artery intima-media thickness. In group I the diastolic blood pressure's odds radio was 1.187 (P=0.035) and the atherosclerosis index odds radio was 37.165 (P=0.001); in group Ⅱ the diastolic blood pressure's odds radio was 1.371 (P=0.009) and the atherosclerosis index odds radio was 30.724 (P=0.015).Conclusion The diastolic blood pressure and atherosclerosis index were the risk factors in pre-clinical arthrosclerosis.Regularly monitoring the high-risk children for the development and progression of vascular lesion would be of great value in avoiding and preventing cardiovascular disease。

Abstract：Background Laryngeal carcinoma is a common malignant tumor of the upper respiratory tract, and in 95% of cases the tumor is laryngeal squamous cell carcinoma (LSCC). The abnormity of SH3-domain GRB2-like 2 (SH3GL2) gene was found in LSCC. In order to clarify the relationship between SH3GL2 gene and LSCC, we evaluated the expression of the SH3GL2 gene in LSCC.Method Real-time PCR, immunohistochemistry and Western blotting were used to detect the mRNA and protein expression and find the various rules of SH3GL2 gene in LSCC.Results The result of real-time PCR showed that the expression level of SH3GL2 mRNA in LSCC tissue was apparently down-regulated; immunohistochemical analysis showed that SH3GL2 protein was mainly located in cytoplasm, the rate of positive cells and SH3GL2 protein expression level were fluctuated with the pathological classification of LSCC; the result of Western blotting showed that SH3GL2 protein was down-regulated significantly in LSCC samples, especially in metastatic lymph nodes.Conclusions These results suggest that SH3GL2 is a LSCC related gene and its expression level is fluctuated with the pathological classification which indicate that SH3GL2 participates in the development and progression of LSCC. And it may be considered as a novel tumor marker to find both a new anti-oncogene and relative factors of invasion and metastasis of laryngeal carcinoma。

Parkinson's disease is a neurodegenerative disorder mainly caused by degeneration of the dopaminergic neurons in the substantia nigral pars compacta (SNpc)。

Abstract：Objective To review the recent research progress in lectin-like oxidized low-density lipoprotein receptor-1 (LOX-1)including its protein, ligands, expression and pathophysiological significance.Data sources Information included in this article was identified by searching of PUBMED (1997-2006) online resources using the key term LOX-1.Study selection Mainly original milestone articles and critical reviews written by major pioneer investigators of the field were selected.Results The key issues related to the LOX-1 protein as well as ligands for LOX-1. Factors regulating the expression of LOX-1 were summarized. The pathophysiological functions of LOX-1 in several diseases were discussed.Conclusions Identification of LOX-1 and a definition of its biological role in pathophysiologic states provide deeper insight into the pathogenesis of some cardiovascular diseases especially in atherosclerosis and provide a potential selective therapeutic approach. LOX-1 is unlocking and drugs targeting LOX-1 might be a promising direction to explore。

Over 75% of patients with acute hepatitis C (HCV)will develop into chronic infection associated with chronic hepatitis, end stage liver disease or hepatocellular carcinoma.1,2

Vascular endothelial growth factor (VEGF) is an angiogenic regulator that stimulates endothelial cell migration, proliferation, and angiogenesis。

Management of patients with aortic dissection includes medical and surgical treatments。

Traumatic or iatrogenic metallic foreign body retained in the heart is not a rare entity. Infective endocarditis associated with a retained nonmetallic foreign body is exceptionally rare。