Volume 119  ·   Issue 06  ·  2006

Abstract：Background Tissue inhibitor of matrix metalloproteinase-1 (TIMP-1) is related to the aging of many organs, but few data are available on the change of TIMP-1 in liver aging. The purpose of this study was to investigate the expression and role of TIMP-1, matrix metalloproteinase-2 (MMP-2) and MMP-9 in the process of natural aging in the livers of normal and transgenic mice, and to detect the effects of TIMP-1 on oxidative level and anti-oxidative ability of the livers of transgenic young mice.Methods Normal and transgenic mice were divided into 3 groups according to their age: 3-month-old group (n=5), 12-month-old group (n=5) and 24-month-old group (n=5). Histopathological changes of the liver were observed after HE and Masson staining. The messenger RNA (mRNA) levels of TIMP-1, MMP-2 and MMP-9 were determined by semi-quantitative reverse transcriptional polymerase chain reaction; protein expression was measured by Western blot in the livers of normal and transgenic mice of various ages. Changes in levels of superoxide dismutase (SOD), monoamine oxidase (MAO), malondialdehyde (MDA) as well as oxidative and anti-oxidative ability were measured.Results Histologically, more fatty degeneration and collagen deposition were found in the aging livers of transgenic mice than in those of the normal mice as their age of months increased. The mRNA and protein expressions of TIMP-1 were significantly high in the oldest animals. The histopathological changes, mRNA and protein expressions of TIMP-1 increased significantly in the liver of transgenic mice as compared with normal mice. The expression of MMP-2 and MMP-9 showed a minor change in the process of aging. Liver change and collagen deposition were not observed in young mice, but the activity of SOD decreased (P<0.05), and the activity of MAO (P<0.01) and the content of MDA increased in the liver of transgenic mice (P<0.01).Conclusions The expression of TIMP-1 is significantly high in the liver of transgenic mouse in the process of aging, indicating that the oxidative level increases and the anti-oxidative ability decreases in the liver of transgenic mouse. TIMP-1 plays an important role in the process of liver aging。

Abstract：Background Resistin, a newly discovered cysteine-rich hormone secreted mainly by adipose tissues, has been proposed to form a biochemical link between obesity and type 2 diabetes. However, the resistin receptor has not yet been identified. This study aimed to identify resistin binding proteins/receptor.Methods Three cDNA fragments with the same 11 bp 5' sequence were found by screening a cDNA phage display library of rat multiple tissues. As the reading frames of the same 11 bp 5' sequence were interrupted by a TGA stop codon, plaque lift assay was consequently used to prove the readthrough phenomenon. The stop codon in the same 11 bp 5' sequence was replaced by tryptophan, and the binding activity of the coded peptide [AWIL, which was designated as resistin binding peptide (RBP)] with resistin was identified by the confocal microscopy technique and the affinity chromatography experiment. pDual GC-resistin and pDual GC-resistin binding peptide were co-transfected into 3T3-L1 cells to confirm the function of resistin binding peptide.Results Three cDNA fragments with the same 11 bp 5' sequence were found. The TGA stop codon in reading frames of the same 11 bp 5' sequence was proved to be readthroughed. The binding activity of RBP with resistin was consequently identified. The expression of the resistin binding peptide in 3T3-L1 preadipocytes expressing pDual GC-resistin significantly inhibited the adipogenic differentiation.Conclusion RBP could effectively rescue the promoted differentiation of resistin overxepressed 3T3-L1 preadipocyte。

Abstract：Background It is known that excessive release of glutamate can induce excitotoxicity in neurons and lead to seizure. Dexamethasone has anti-seizure function. The aim of this study was to investigate glutamate- dexamethasone interaction in the pathogenesis of epilepsy, identify differentially expressed genes in the hippocampus of glutamate-induced epileptic rats by mRNA differential display, and observe the effects of dexamethasone on these genes expression.Methods Seizure models were established by injecting 5 μl (250 μg/μl) monosodium glutamate (MSG) into the lateral cerebral ventricle in rats. Dexamethasone (5 mg/kg) was injected intraperitoneally at 30 minutes after MSG inducing convulsion. The rats' behavior and electroencephalogram (EEG) were then recorded for 1 hour. The effects of dexamethasone on gene expression were observed in MSG-induced epileptic rats at 1 hour and 6 hours after the onset of seizure by mRNA differential display. The differentially expressed genes were confirmed by Dot blot.Results EEG and behaviors showed that MSG did induce seizure, and dexamethasone could clearly alleviate the symptom. mRNA differential display showed that MSG increased the expression of some genes in epileptic rats and dexamethasone could downregulate their expression. From more than 10 differentially expressed cDNA fragments, we identified a 226 bp cDNA fragment that was expressed higher in the hippocampus of epileptic rats than that in the control group. Its expression was reduced after the administration of dexamethasone. Sequence analysis and protein alignment showed that the predicted amino acid sequence of this cDNA fragment kept 43% identity to agmatinase, a member of the ureohydrolase superfamily. Conclusions The results of the current study suggest that the product of the 226 bp cDNA has a function similar to agmatinase. Dexamethasone might relax alleviate seizure by inhibiting expression of the gene。

Abstract：Background Autologous transplantation of the submandibular gland (SMG) into the temporal fossa with microvascular anastomosis has been successfully applied in severe xerophthalmia patients as a permanent tear substitute. However, severe xerophthalmia can be accompanied by salivary gland dysfunction, making such autotransplantation unsuitable. Therefore, SMG allotransplantation might be a solution. The aim of this study was to assess the technical feasibility of submandibular gland allotransplantation.Methods Twelve miniature swine were randomized to serve as donors or recipients. One SMG was transplanted between a donor and a recipient. The donor SMG was revascularized by microvascular anastomosis of its vascular pedicle to the recipient lingual artery and external jugular vein. The secretory duct was implanted into the vestibule of the mouth through a subcutaneous tunnel. No immunosuppressive agent was administered. The results were assessed by visual inspection of the secretion, and histopathological examination of the transplanted SMG.Results Technically, all surgical procedures were successful. Clear secretion flowed out of the duct as soon as blood supply of the transplanted submandibular gland was reestablished. The secretion of the gland lasted for 5 days. As expected, an acute rejection reaction occurred after surgery because no immunosuppressive agents were used. Secretion from the transplanted SMG ceased within 5 days. Conclusions A model of SMG allotransplantation can be established in miniature swine. The technique of submandibular gland allotransplantation is feasible。

Abstract：Background Because of the pivotal role of the human leukocyte antigen (HLA) class II molecules in regulating the immune response and their extensive polymorphism, it is not surprising that particular HLA class II alleles have been implicated in susceptibility to allergic diseases and in restriction of the IgE responses to a variety of allergens. We investigated the relationship between HLA-DRB genotype and allergies to various penicillins and explored HLA-DRB restriction of IgE responses to these derivatives of penicillin.Methods Radioallergosorbent test was used to examine 8 kinds of specific IgE antibodies (4 major and 4 minor antigenic determinants) in the sera of 248 patients with an allergy to penicillins and 101 healthy subjects without any allergic reaction. Some (113 patients and 87 healthy control subjects) were chosen from all subjects to type for HLA-DRB alleles by sequence specific primer-polymerase chain reaction.Results Compared with control subjects, a significantly increased frequency of DR9 was present in 77 patients with allergic reactions, with immediate hypersensitive reaction and with urticaria (P = 0.011; P = 0.019; P = 0.005 respectively). Conversely, a significantly decreased frequency of DR14.1 was found in 80 patients with positive IgE antibodies, with immediate reaction and with urticaria compared with control group (P = 0.024; P = 0.038; P = 0.038). A possible excess of HLA-DR17 was found in subjects who were responsive to benzylpenicilloyl compared with those were not (χ2 = 5.134, P = 0.023), and of HLA-DR4 was found in subjects responsive to phenoxomethylpenicillanyl (PVA, χ2 = 4.057, P = 0.044).Conclusion HLA-DRB gene may be involved in allergy to penicillins through modulating specific serum IgE to penicillins。

Abstract：Background Nominal atrioventricular (AV) interval in dual chamber pacemaker (DDD) is not the best AV delay in the majority of patients with atrioventricular block. To find a simple method for optimizing AV delay adjustment, we assessed surface electrocardiography (ECG) for optimizing AV delay during dual chamber pacing.Methods DDD pacemakers were implanted in 46 patients with complete, or almost complete, AV block. Optimal AV delay was achieved by programming an additional delay of 100 ms, to the width of intrinsic P wave or to the interval between pacing spike to the end of P wave on surface ECG. Left ventricular (LV) end diastolic and end systolic volumes, ejection fraction and diastolic parameters were measured by Doppler echocardiography during both nominal and optimal AV delay pacing.Results Compared to nominal AV delay setting, LV end diastolic volume increased [to (53.2±11.3) ml from (50.2±10.2) ml, P<0.05], end systolic volume decreased [to (26.1±9.0) ml from (27.9±8.2) ml, P<0.05] during adjusted AV delay pacing, resulting in an increase in LV ejection fraction [to (68.2±5.3)% from (64.5±4.3)%, P<0.05]. LV diastolic filling and isovolumic relaxation time were not significantly changed.Conclusion Optimization of AV delay by surface ECG is a simple method to improve LV systolic function during dual chamber pacing。

Abstract：Background Previous clinical studies have suggested that patients with congestive heart failure and intraventricular conduction delay could benefit from cardiac resynchronization therapy (CRT). Implantation of left ventricular lead is a complex procedure with some potential for complications. This study was conducted to analyse the complications of CRT in patients with congestive heart failure.Methods Totally 117 patients, 86 males and 31 females, mean age of 53 years, with congestive heart failure and intraventricular conduction delaywere enrolled in this study. Venography was performed on all patients. Different types of coronary sinus leads were used to pace the left ventricle. Results Left ventricular lead was attempted to implant through coronary sinus for all the 117 patients and was successfully implanted in 111 patients. The success rate was 94.9%. Main complications rate was 6.8%, including coronary sinus dissection in 4 patients, phrenic nerve stimulation required lead repositioning in 2 patients and lead dislodgement in 2 patients. Conclusions It is feasible and safe to pace left ventricle through coronary sinus. However, there are some procedural complications。

Abstract：Background Laparoscopic Heller cardiomyotomy and Dor fundoplication is the surgical procedure of choice for esophageal achalasia. The aim of this study was to investigate the clinical outcome of laparoscopic Heller-Dor procedure in our initial series of 25 patients with achalasia.Methods Between October 2003 and January 2006, a total of 25 patients with achalasia underwent laparoscopic Heller-Dor operation. Among them, 9 were male and 16 were female with an average age of (41.5±5.1) years (21-66). All the patients received upper gastrointestinal series (barium swallow), esophagogastroscopy, esophageal manometry to exclude esophageal carcinoma and to confirm the diagnosis, and 21 patients also had 24-hour ambulatory pH studies. All the patients were operated by laparoscopic modified Heller's myotomy with Dor fundoplication. In addition, 2 of them had combined laparoscopic cholecystectomy + excision of hepatic hemangioma and laparoscopic cholecystectomy, respectively. Results The average operating time was (110.6±12.9) minutes (range, 60-180), operative blood loss averaged (18.6±7.1) ml (5-50), the median time to oral feeding was (1.6±0.4) days (1-4) and the median hospital stay was (12.6±1.2) days (10-20). There was no conversion to open surgery. Intraoperative mucosal perforation was encountered in six patients and was repaired in all of them by laparoscopic suture. All the patients had an uneventful recovery without postoperative complication. After a median follow-up of (10.6±7.2) months (1-27),24 patients were asymptomatic and 1 had mild postoperative dysphagia. Conclusions Laparoscopic Heller-Dor operation had the advantages of reduced compromise of the cardiopulmonary function, with less disruption of the supporting structures (phrenoesophageal membrane) of the antireflux mechanism, requiring simpler general anesthesia and providing excellent exposure permitting an easy fundoplication, less pain and reduced morbidity, shorter hospitalization and faster convalescence。

Background Infections caused by gram-negative bacteria (GNB) often lead to high mortality in common clinical settings. The effect of traditional antibiotic therapy is hindered by drug-resistant bacteria and unneutralizable endotoxin. Few effective methods can protect high risk patients from bacterial infection. This study explored the protection of adeno-associated virus 2 (AAV2)-bacteriacidal permeability increasing protein 700 (BPI700)-fragment crystallizable gamma one 700 (Fcγ1700) chimeric gene transferred mice against the minimal lethal dose (MLD) of E.coli and application of gene therapy for bacterial infection.Methods After AAV2-BPI700-Fcγ1700 virus transfection,dot blotting and Western blotting were used to detect the target gene products in Chinese hamster ovary-K1 cells (CHO-K1cells). Reverse transcription-polymerase chain reaction and immunohistochemical assay were carried out to show the target gene expression in mice. Modified BPI-enzyme linked immunosorbent assay was used to identify the target gene products in murine serum. The protection of BPI700-Fcγ1700 gene transferred mice was examined by survival rate after MLD E. coli challenge. Colony forming unit (CFU) count, limulus amebocyte lysate kit and cytokine kit were used to quantify the bacteria, the level of endotoxin, and proinflammatory cytokine.Results BPI1-199-Fc(1 protein was identified in the CHO-K1 cell culture supernatant, injected muscles and serum of the gene transferred mice. After MLD E. coli challenge, the survival rate of AAV2-BPI700-Fc(1700 gene transferred mice (36.7%) was significantly higher than that of AAV2-enhanced green fluorescent protein (AAV2- EGFP) gene transferred mice (3.3%) and PBS control mice (5.6%). The survival rate of AAV2-BPI700-Fc(1700 gene transferred mice treated with cefuroxime sodium was 65.0%. The bacterium number in main viscera, the levels of endotoxin and proinflammatory cytokine (tumor necrcsis factor-α and interleukin-1β) in serum of the AAV2-BPI700-Fc(1700 gene transferred mice were markedly lower than that of PBS control mice (P<0.01).

Abstract：Background Contrast-enhanced fluid-attenuated inversion-recovery (FLAIR) magnetic resonance imaging (MRI) has been reported to have higher sensitivity for detecting leptomeningeal disease compared with contrast- enhanced T1-weighted MRI (CE T1WI). However, currently there are no studies showing the potential value of clinical applications of contrast-enhanced FLAIR (CE FLAIR) sequence in diagnosing intracranial tumors in a larger group of patients. The purpose of this study was to evaluate the diagnostic value of CE FLAIR in comparison with CE T1WI for intracranial tumors and to provide more information for clinical diagnosis and therapy.Methods One hundred and four consecutive cases of intracranial tumors referred for CE brain MRI were analyzed with regard to FLAIR and T1WI pre- and post-administration of Gd-DTPA. The CE FLAIR and CE T1WI were evaluated independently by two radiologists for the number of examinations with one or more enhanced lesions, the number and location of enhanced lesions per examination, signal-to-noise ratio (SNR) and contrast-enhancement ratio (CER) of lesions, as well as the size and extent of the enhanced lesions. Results In 98 of 104 cases, enhanced lesions were seen both on the FLAIR and T1W images. More lesions were seen on CE T1WI (n=120) than those on CE FLAIR sequence (n=117), but no differences of statistical significance were found between the two sequences (P>0.05). Four lesions were revealed only on the CE FLAIR images whereas 7 lesions were only found on CE T1WI. Enhanced lesions located in the cerebral hemisphere or the forth ventricle were revealed much more on CE T1WI than on CE FLAIR images. However, CE FLAIR images may be useful in showing superficial abnormalities and those located in the sulcus or lateral ventricle. The CER and contrast-to-noise ratio (CNR) on CE T1WI was significantly higher (t=7.10,P=0.00;t=9.67,P=0.00, respectively), but grey matter/white matter contrast was lower (t=2.46,P=0.02) than those on CE FLAIR images. The SNR did not show any statistically significant difference between the two sequences (t=1.1, P=0.27). The size and extent of lesions on the CE FLAIR images were significantly larger than those on CE T1WI (t=4.13, P=0.00). Conclusions CE FLAIR and CE T1WI may complement each other in showing intracranial tumors and the CE FLAIR sequence should be selected as a routine MRI sequence。

Several subsets of T-regulatory (Tr) cells with distinct phenotypes and distinct mechanisms of action have been identified. These include Tr type 1 (Tr1) cells; Th3 cells, which primarily secrete transforming growth factor (TGF)-β; and CD4+CD25+ T cells, which inhibit immune responses through cell to cell contact.1 It has been shown that CD4+CD25+ immunoregulatory T cells induced by the blockade of CD154-CD40 pathway are tolerant to alloantigen, resulting in secondary mixed lymphocyte reaction (MLR) hyporesponsiveness in vitro and tolerance to alloantigen in vivo.2,3 Previous studies mainly paid attention to CD4+CD25+ immunoregulatory T cells induced by CD154-CD40 blockade, but it was unclear whether CD154-CD40 blockade might induce Tr1 or Tr1-like cells。

Trisomy 21, also named Down syndrome was the most frequent autosomal aneuploidy and the most common cause of mental retardation. Fifty percent patients had congenital heart malformation. Every 20 minutes one case of trisomy 21 was born, and the incidence rate was 1 in 600 to 800 newborns in China.1 In two thirds of cases with trisomy 21, there was a spontaneous abortion, so the actual incidence was higher than that obtained postnatally。

The curative effect of CO2 laser in treatment of glottic carcinoma has been focused on for a long time. The oncologic results were based on the comparison with conventional methods, survival rate and laryngeal function outcome. Data in the past literature produced convincing evidence that endoscopic surgery with CO2 laser can be considered as a valid alternative to radiotherapy and open neck surgery (larynfissure cordectomy, vertical partial laryngectomy, etc)。

Simple bone cyst (SBC), also known as a unicameral or solitary cyst, is a benign fluid-filled cavity found primarily at the proximal ends of long bones in children. Treatment is warranted if the pain or a pathologic fracture occurs or if a child is at risk of pathologic fractures. The spectrum of treatments proposed for SBC management ranges from simple Kirschner wire drill-hole, resection or curettage with or without bone grafting to using a cannulated screw for continuous decompression, steroid injection and the latest experience of the use of percutaneous autologous marrow grafting.1-4 However, clinical practice of these treatments is limited because of their unsatisfactory effect and possible compli- cations。

About 40% of patients with thymoma have one or more paraneoplastic syndromes, including myasthenia gravis, pure red cell aplasia (PRCA) or hypogammaglobulinaemia, but Good syndrome occurs in only 5% of these conditions. To our knowledge, only 11 patients (including our cases) of thymoma accompanied with PRCA and Good syndrome have been reported,1 however, no such case was reported in China before 2000。

Professor WANG Qiu-sheng and his colleagues are to be complemented for the excellent results and clinical outcome following laparoscopic cardiomyotomy in their initial experience of 25 patients。