Effect of gene polymorphims on the warfarin treatment at initial stage

The adverse reactions of warfarin that were found mainly occurred in the first month. This study was carried out to observe the effect of gene polymorphisms on the warfarin therapy at the initial stage. Four-hundred and sixty Chinese patients began warfarin treatment with daily 2.5 mg after heart valve replacement operations were enrolled. The daily international normalized ratio (INR) for anticoagulation were recorded till the seventh day. Blood samples were collected and used to detect genotypes for VKORC1 rs7294, CYP2C9 rs1057910, CYP4F2 rs2108622 and ORM1 rs17650. INR and their changes were compared among genotypes. INR was partially correlated with the VKORC1 rs7294, CYP2C9 rs1057910, CYP4F2 rs2108622 and ORM1 rs17650 polymorphisms from the third, fourth and sixth day on, respectively. VKORC1 rs7294 and CYP4F2 rs2108622 carriers responded lower than the wild genotype, whereas CYP2C9 rs1057910 and ORM1 rs17650 carriers responded higher, respectively. Fifty percent of AA/*1*3/CC/*S*S patients and 16% of AA/*1*1/CC/*S*S patients were over anticoagulation treated with INR >4.0 at the third day. Ninety percent of VKORC1 rs7294 carrier patients have INR <1.63, a mark of the 25% of lower responders of the wild genotype. Our study provided another kind of evidence that VKORC1 rs7294, CYP2C9 rs1057910, CYP4F2 rs2108622 and ORM1 rs17650 affected the action of warfarin in different styles. Patients with AA/*1*1/CC/*S*S, AA/*1*3/CC/*S*S should use a less initial dosage to avoid over anticoagulation, and patients with VKORC1 rs7294 should use larger initial dose to proof an effective therapy.

[Assessment of quality of life after multiple arthroplasty]

OBJECTIVE

To evaluate the effectiveness of conducting multiple arthroplasty to treat multiple joints disease in terms of quality of life (QOL) and function improvement.

METHODS

We compared our results with the reported results of single and dual arthroplasty to see if there is any improvement in QOL, functional scores or complications. In this study, 13 patients admitted to Department of Adult Reconstructive Surgery, Beijing Jishuitan hospital from 2005 to 2009 were included. Questionnaires SF-36 were used to evaluate the QOL. Harris hip score, American Knee Society Score (KSS) were used to evaluate the joint function. The patients were evaluated before surgery to the latest follow up.

RESULTS

SF-36 has changed as follow: physical function 4.17 ± 14.43 → 65.83 ± 24.76, role physical 25.00 ± 26.11 → 60.42 ± 45.8, bodily pain 23.83 ± 21.41 → 76.88 ± 20.89, general health 53.33 ± 33.87 → 76.67 ± 14.67, vitality 50.42 ± 17.25 → 71.67 ± 16.28, social functioning 29.17 ± 33.50 → 73.96 ± 33.90, role emotional 22.08 ± 35.61 → 77.77 ± 41.03, mental health 53.33 ± 25.70 → 82.67 ± 14.41, which indicated that they all improved greatly after the surgery (P < 0.05). Harris score increased from 37.68 ± 14.71 before the surgery to 83.36 ± 13.54 after the surgery. KSS has also showed sharp improvement (P < 0.001) in both clinical score (42.52 ± 23.83 → 77.74 ± 20.67) and function score (-2.61 ± 22.56 → 65.65 ± 30.76).

CONCLUSION

Multiple arthroplasty is one of the most effective methods which can markedly improve the quality of life in patients with multiple joints disease. But complications are common and joint functions are relatively poor.

[Comparative study of total hip arthroplasty with subtrochanteric osteotomy for treating Hartofilakidis types C1 and C2 developmental dysplasia of the hip]

OBJECTIVE

To compare efficacies and complications of total hip arthroplasty (THA) with subtrochanteric osteotomy for treating patients with Hartofilakidis types C1 and C2 developmental dysplasia of the hip (DDH).

METHODS

Retrospective analysis was performed in 32 patients with DDH who underwent THA. These patients were divided into two groups according to Hartofilakidis classification, 17 patients in type C1 and 15 in type C2. Their HSS and WOMAC scores, leg length discrepancy (LLD), hip joint image data and complications were evaluated.

RESULTS

HSS scores in type C1 was changed from preoperative 43.7±4.6 to postoperative 87.2±7.1 (P<0.001), together with WOMAC scores 43.6±4.3 to 87.5±6.7 (P<0.001). HSS scores in type C2 was changed from preoperative 44.4±5.4 to postoperative 86.5±8.0 (P<0.001), together with WOMAC scores 44.1±4.1 to 86.7±8.1 (P<0.001). Four cases in type C2 and one case in type C1 presented intraoperative fracture which all healed during the postoperative follow-up. The postoperative X-ray films showed that the joint prosthesis location was satisfactory, the surrounding bone was not dissolved and the bone at femur osteotomy site healed with no infection.

CONCLUSION

For unilateral high dislocation DDH patients, THA with femur osteotomy can be effective and safe. No significant differences were found between types C1 and C2, however intraoperative fracture in type C2 should be paid attention to.

Acute rejection correlates with expression of major histocompatibility complex class I antigens on peripheral blood CD3(+)CD8(+) T-lymphocytes following skin transplantation in mice

This study investigated major histocompatibility complex class I (MHC-I) antigen expression on peripheral blood T-cells after transplantation to assess its potential as an early marker of acute graft rejection (AGR). Using a mouse model with or without immunosuppressive treatment, the expression of MHC-I antigens on CD3(+)CD8(+) T-lymphocytes was assessed by flow cytometry following syngeneic graft (n = 138) or allograft (n = 138) skin transplantation. The occurrence of AGR was assessed by examining the degree of lymphocyte and monocyte infiltration in transplant biopsies. During AGR, expression of MHC-I antigens increased significantly compared with pre-transplant levels in the allograft group, even with immunosuppressive treatment. The highest expression of MHC-I antigens occurred 5 - 6 days before macroscopic rejection. These results suggest that expression of MHC-I antigens on peripheral blood CD3(+)CD8(+) T-lymphocytes could be used as an early marker for predicting AGR.

Long-term outcomes following repair or replacement in degenerative mitral valve disease

BACKGROUND

We studied whether mitral valvuloplasty (MVP) was superior to mitral valve replacement (MVR) in patients with degenerative mitral regurgitation (MR), and analyzed the independent risk factors for survival and reoperation.

METHODS

326 patients with degenerative MR underwent MVP (n = 241), mitral valve replacement (MVR) (n = 78) or emergent MVR due to failure of repair (EMVR). Clinical data were analyzed retrospectively.

RESULTS

Thirty-day mortality was lower after MVP (2.5 %) compared to MVR (9.0 %) ( P < 0.05). Late survival at 1 and 5 years in the MVP group was 94.4 % and 84.3 % versus 80.4 % and 64.6 % in the MVR group ( P < 0.05), respectively. After adjusting the baseline characteristics by the propensity score method, a significant survival benefit was found for patients who underwent MVP. Multivariable analysis showed that MVR was an independent predictor of thirty-day mortality and survival. There was no significant difference in thirty-day mortality and survival between the EMVR and MVR groups. The need for reoperation was not significantly different between the MVP and MVR groups. In the MVP group, the risk factors for survival and reoperation were identified.

CONCLUSIONS

MVP is superior to MVR for the treatment of degenerative MR despite the impact of repair failure. Age less than 60 years, ring size to body surface area greater than 19.0, absence of a prosthetic ring and residual MR at the end of surgery (≥ 1/4) reduce the durability of MVP.

Safe zone for transacetabular screw fixation in prosthetic acetabular reconstruction of high developmental dysplasia of the hip

BACKGROUND

Prosthetic reconstruction of hips with Crowe type-IV developmental dysplasia (a high complete dislocation) is technically demanding. Insufficient osseous coverage and osteopenic bone stock frequently necessitate transacetabular screw fixation to augment primary stability of the metal acetabular shell. We sought to determine whether a previously reported quadrant system for screw fixation of the acetabular cup can be applied in patients with high dislocation of the hip and to define a specialized safe zone for screw fixation in these hips, if needed.

METHODS

Using volumetric computed tomographic data and image-processing software, we made three-dimensional reconstructions of the osseous and vascular structures in eighteen hips in twelve patients. We virtually reconstructed a cup in the true acetabulum and dynamically simulated transacetabular screw fixation. We mapped the hemispheric cup into several areas and, for each, measured the distance between the virtual screw and the external iliac (femoral) and obturator blood vessels. In the six patients with unilateral high dislocation of the hip and a relatively normal, contralateral hip, the six relatively normal hips served as controls.

RESULTS

Reconstruction of the cup at the level of the true acetabulum shifted the center of rotation anteroinferiorly in the hips with a high, complete dislocation. Screws guided by the quadrant system frequently injured the obturator blood vessels in the hips with a high dislocation. In these patients, the safe zone shifted as a result of moving the prosthetic cup.

CONCLUSIONS

The quadrant system, although helpful in determining screw placement in hips with a normal center of rotation, can be misleading and of less value in guiding screw insertion to augment acetabular shells for hips with a high dislocation. We believe that a safe zone specific to hips with a high dislocation should be used to guide transacetabular screw fixation.

Scavenger Receptor Class B Type I Mediates Cell Entry of Hepatitis C Virus

This study assessed the functional role of human scavenger receptor class B type I (SR-BI) as a putative hepatitis C virus (HCV) receptor using Chinese hamster ovary (CHO) cells transfected with human SR-BI (CHO–huSR-BI). The expression of SR-BI by primary Tupaia hepatocytes (PTHs), human hepatocarcinoma cell line (HepG2) cells, untransfected CHO cells and CHO–huSR-BI cells was analysed by Western blotting. Receptor competition assays showed that anti-SR-BI antibodies that block the binding of soluble envelope glycoprotein E2 could prevent HCV infection. Pre-incubation of CHO–huSR-BI and HepG2 cells with anti-SR-BI antibodies resulted in marked inhibition of E2 binding. After incubation with HCV RNA-positive serum from a patient with chronic HCV infection, however, HCV infection could not be detected in CHO–huSR-BI cells, but was detected in PTHs. These results demonstrate that, whilst SR-BI represents an important cell surface molecule for HCV infection, the presence of SR-BI alone is insufficient for HCV entry.

Current through single conjugated molecules: calculations versus measurements

We use density functional theory based nonequilibrium Green's function to calculate the current through the different rodlike molecules at the finite temperatures self-consistently, which was compared to the experimental measurements presented by Reichert et al. [Phys. Rev. Lett. 88, 176804 (2002)] and by Mayor et al. [Angew. Chem. Int. Ed. 42, 5834 (2003)], respectively. Our results agree with the measurements very well, especially for the bias around +/-1.0 V. The investigation of the topological effect for the symmetrical molecule reveals the fact that the para position compound provides a considerably larger conductance than the meta one.

Ab initiostudy of single-molecule rotation switch based on nonequilibrium Green’s function theory

The bistable molecular switches have been studied theoretically based on the first-principles calculation. The geometry structures of the switches studied in this paper can be triggered between two symmetrical structures by using an external applied electric field. I-V characteristic curves of the different molecule configurations have been calculated, and distinguishability of these characteristic curves indicates a switching behavior, the performance of which can be improved significantly by some suitable donors and acceptors.

Validation of the mainland Chinese version of the Inflammatory Bowel Disease Questionnaire (IBDQ) for ulcerative colitis and Crohn's disease

BACKGROUND

Inflammatory bowel disease affects the quality of a patient's life in many ways, but no validated instrument for measuring disease-specific quality of life in these patients is available for use in Mainland China. The aim of our study was to develop and validate the Mainland Chinese translation of the Inflammatory Bowel Disease Questionnaire for ulcerative colitis (UC) and Crohn's disease (CD) by assessing its construct validity, discriminant ability, reliability, and sensitivity to change.

METHODS

We administered a developed Mainland Chinese version of the Inflammatory Bowel Disease Questionnaire (IBDQ). Ninety-two Mainland Chinese patients (52 with UC and 40 with CD) completed the Mainland Chinese version of the IBDQ, the Chinese version of SF-36, and the global scale for general well-being. A subgroup of 71 patients also completed the Mainland Chinese version of the IBDQ and the global scales for general well-being on a second occasion. Clinical activity was assessed by the Walmsley and Harvey-Bradshaw simple indices.

RESULTS

The Mainland Chinese IBDQ scores correlated well with the related SF-36 dimensional scores for all 4 domains (r = 0.51-0.82), SF-36 total scores (r = 0.58-0.87), the colitis activity index (r = -0.56-0.74), and the CD activity index (r = -0.64-0.78) as well as with the global scales. The Mainland Chinese IBDQ was able to discriminate between active and inactive disease. Cronbach's alpha was 0.95 in UC and 0.94 in CD. Test-retest reliability was excellent (intraclass correlation coefficient 0.69-0.93) when it was repeated in patients whose clinical activity index was stable. In contrast, there was a significant difference between the baseline and follow-up measurements in patients whose clinical activity index was changed.

CONCLUSIONS

The Mainland Chinese IBDQ proved to be a valid, discriminative, and reliable instrument for assessing health-related quality of life in patients with UC and CD in Mainland China.

VEGF-Targeted RNA Interference Suppresses Angiogenesis and Tumor Growth of Retinoblastoma

Vascular endothelial growth factor (VEGF) is one of the most important angiogenic growth factors for tumor angiogenesis which has been verified to be involved in neovascularization of retinoblastoma. Here, we sought to explore whether RNA interference (RNAi) targeting VEGF could inhibit retinoblastoma angiogenesis and tumor growth. Stable transfection of the two human retinoblastoma cell lines SO-RB50 and HXO-RB44 with VEGF-targeted small interfering RNA (siRNA) expression plasmid significantly inhibited VEGF expression determined by real-time polymerase chain reaction (PCR), enzyme-linked immunosorbent assay and Western blot, whereas the control transfection showed no effects. The chemically synthesized VEGF siRNA dramatically suppressed tumor angiogenesis (CD34 immunohistochemistry) and tumor growth in the SO-RB50 subcutaneous xenograft model. Significant downregulation of VEGF expression both on messenger RNA and protein levels in VEGF-siRNA-treated SO-RB50 subcutaneous xenograft was confirmed by real-time PCR and Western blot compared to control. Our data demonstrate the suppression function on angiogenesis and tumor growth of retinoblastoma by VEGF-targeted RNAi. This novel therapeutic strategy promises to play a part in the clinical management of retinoblastoma.

Self-consistent study of single molecular transistor modulated by transverse field

We use a self-consistent method to study the current of the single molecular transistor modulated by the transverse field in the level of the density functional theory and the nonequilibrium Green function method. The numerical results show that both the polyacene-dithiol molecules and the fused-ring thiophene molecules are the potential high-frequency molecular transistors controlled by the transverse field. The longer molecules of the polyacene-dithiol or the fused-ring thiophene are in favor of realizing the gate-bias controlled molecular transistor. The theoretical results suggest the related experiments.

[Determination of evodiamine and rutaecarpine in Evodia rutaecarpa (Juss.) Benth after compatibility with Coptis chinensis Franch]

OBJECTIVE

To studying changes of evodiamine and rutaecarpine in E. rutaecarpa after compatibility with C. chinensis.

METHOD

An YWG C18 column was used with a mobile phase of CH3CN-H2O(40:60), the flow rate was 1.0 ml.min-1 and the detection wavelength was 290 nm.

RESULT

The average recovery was 97.82% and 97.00%, the relative standard deviation was 0.81% and 1.10% for evodiamine and rutaecarpine respectively.

CONCLUSION

The amounts of evodiamine and rutaecarpine were decreased after compatibility with C. chinensis.

Injury to the ligamentum teres. Mechanism, findings, and results of treatment

In this article we discuss the role of the ligamentum teres in relation to the hip joint. The anatomy of the ligamentum teres is used to help with an understanding of the mechanism of the ligament's actions. This action and the modes of injury to the ligament are explored. We describe a simple classification system for injuries to the ligamentum teres, such that Group I are complete tears to the ligament; Group II are partial tears; and Group III are degenerative tears. As more experience is gained with the diagnosis and treatment of injuries to this integral structure, the clearer will be our understanding of the role of the ligamentum teres in the hip joint.

Phosphonate ester probes for proteolytic antibodies

The reactivity of phosphonate ester probes with several available proteolytic antibody (Ab) fragments was characterized. Irreversible, active site-directed inhibition of the peptidase activity was evident. Stable phosphonate diester-Ab adducts were resolved by column chromatography and denaturing electrophoresis. Biotinylated phosphonate esters were applied for chemical capture of phage particles displaying Fv and light chain repertoires. Selected Ab fragments displayed enriched catalytic activity inhibitable by the selection reagent. Somewhat unexpectedly, a phosphonate monoester also formed stable adducts with the Abs. Improved catalytic activity of phage Abs selected by monoester binding was evident. Turnover values (kcat) for a selected Fv construct and a light chain against their preferred model peptide substrates were 0.5 and 0.2 min(-1), respectively, and the corresponding Michaelis-Menten constants (Km) were 10 and 8 microm. The covalent reactivity of Abs with phosphonate esters suggests their ability to recapitulate the catalytic mechanism utilized by classical serine proteases.

[HPLC fingerprints identification of Panax ginseng C. A. Mey., P. quinquefolin L. and P. notoginseng (Burk. F. H. Chen)]

OBJECTIVE

The method was established to identify Panax ginseng, P. quinquefolium and P. notoginseng.

METHOD

Polaris C18-A analytical column (250 mm x 4.6 mm, 5 microns); acetonitrile-water as gradient eluent, flow rate 1.5 ml.min-1, detective wavelength at 203 nm.

RESULT AND CONCLUSION

The fingerprints of P. ginseng, P. quinquefolium and P. notoginseng were obtained, and all ginsenosides were analyzed perfectly. The peak height ratio of ginsenoside Rg1 and ginsenoside Re was a suitable character to differentiate the three species from each other.

Inhibiting effect of antisense oligonucleotides phosphorthioate on gene expression of TIMP-1 in rat liver fibrosis

AIM

To observe the inhibition of antisense oligonucleotides (asON) phosphorthioate to the tissue inhibitors metalloproteinase-1 (TIMP-1) gene and protein expression in the liver tissue of immunologically induced hepatic fibrosis rats. The possibility of reversing hepatic fibrosis through gene therapy was observed.

METHODS

Human serum albumin (HSA) was used to attack rats, as hepatic fibrosis model, in which asONs were used to block the gene and protein expressing TIMP-1. According to the analysis of modulator, structure protein, coding series of TIMP-1 genome, we designed four different asONs. These asONs were injected into the hepatic fibrosis models through coccygeal vein. The results was observed by RT-PCR for measuring TIMP-1 mRNA expression, immunohistochemistry and in situ hybridization for collagen I, II, special staining of collagen fiber, and electron microscopic examination.

RESULTS

Hepatic fibrosis could last within 363 days in our modified model. The expressing level of TIMP-1 was high during hepatic fibrosis process. It has been proved by the immunohistochemical and the electron microscopic examination that the asON phosphorthioate of TIMP-1 could exactly express in vivo. The effect of colchicine was demonstrated to inhibit the expressing level of mRNA and the content of collagen I, III in the liver of experimental hepatic fibrosis rats. However, the electron microscopy research and the pathologic grading of hepatic fibrosis showed that there was no significant difference between the treatment group and the model group (P> 0.05).

CONCLUSION

The experimental rat model of hepatic fibrosis is one of the preferable models to estimate the curative effect of anti-hepatic fibrosis drugs. The asON phosphorthioate of TIMP-1 could block the gene and protein expression of TIMP-1 in the liver of experimental hepatic fibrosis rats at the mRNA level. It is possible to reverse hepatic fibrosis, and it is expected to study a new drug of antihepatic fibrosis on the genetic level. Colchicine has very limited therapeutic effect on hepatic fibrosis, furthermore, its toxicity and side effects are obvious.

[Contents of total flavonoids in Rhizoma Arisaematis]

OBJECTIVE

Comparing the contents of total flavonoides of Rhizoma Arisaematis, which collected in different time, regions, different varieties and processed.

METHOD

Determining the contents by ultraviolet spectro-photometry.

RESULT AND CONCLUSION

The contents were found in the following sequence: 1. the end of July, the begin of July, August, September; 2. Beijing, Shanxi, Sichuan, Anhui; 3. Arisaema erubenscens, A. heterophyllum, A. amurense; 4. unprocessed product, processed product.

Spinocerebellar ataxia type 1 in China: molecular analysis and genotype-phenotype correlation in 5 families

BACKGROUND

Twelve genetic types of autosomal dominant hereditary ataxia have been recently identified and the genes responsible for most of them cloned. Molecular identification of the type of ataxia is important to determine the disease prevalence and its natural history in various populations.

OBJECTIVES

To perform molecular analysis of 75 Chinese families affected with spinocerebellar ataxia (SCA) and to evaluate the spectrum of mutations in these genes and the correlation between genotypes and phenotypes in Chinese patients.

SETTING

Neurogenetics Unit, China-Japan Friendship Hospital, Beijing, China.

METHODS

One hundred nine patients from 75 kindreds diagnosed as having autosomal dominant SCA, 16 patients with sporadic SCA or spastic paraplegia, 280 control chromosomes of the Chinese population, and 120 control chromosomes of the Sakha population were selected for this study. We conducted detailed mutational analysis by direct sequencing of polymerase chain reaction products amplified from genomic DNA.

RESULTS

Spinocerebellar ataxia type 1 (SCA1) was identified in 5 families with 12 studied patients. All affected family members were heterozygous for a CAG repeat expansion in the SCA1 gene containing 51 to 64 trinucleotide repeats. Normal alleles had 26 to 35 repeats. Spinocerebellar ataxia type 1 accounted for 7% of the studied Chinese families with ataxia. In addition, we determined the frequency of a single vs double CAT interruption in 120 control chromosomes of the Siberian Sakha population, which has the highest known prevalence of SCA1, and compared this with 280 control chromosomes from the Chinese populations. The results show that 64.7% of the Siberian normal alleles contain a single CAT interruption, whereas 92% of the Chinese had more than 1 interruption.

CONCLUSIONS

Spinocerebellar ataxia type 1 is responsible for 7% of affected families in the Chinese population. A correlation between the prevalence of SCA1 and the number of CAT interruptions in the trinucleotide chain suggests that a CAT-to-CAG substitution may have been the initial event contributing to the generation of expanded alleles and influencing relative prevalence of SCA1.

[Studies on the fingerprint of radix notoginseng and its preparation]

OBJECTIVE

A fingerprint of raw material, extracted and injections of radix notoginseng has been studied and provides the quality information.

METHOD

Polaris C18-A column was used, with mixtures of acetonitrile and water as mobile phase in a gradient mode. The wavelength of measurement was 203 nm.

RESULT

According to the selected chromatographic conditions, a good fingerprint of radix notoginseng and its extract, preparation has been described.

CONCLUSION

The method is simple, accurate with good reproducibility. It may be practical value for the quality control of sample for radix notoginseng and its preparation.

A Pro250Arg substitution in mouse Fgfr1 causes increased expression of Cbfa1 and premature fusion of calvarial sutures

Pfeiffer syndrome is a classic form of craniosynostosis that is caused by a proline-->arginine substitution at amino acid 252 (Pro252Arg) in fibroblast growth factor receptor 1 (FGFR1). Here we show that mice carrying a Pro250Arg mutation in Fgfr1, which is orthologous to the Pfeiffer syndrome mutation in humans, exhibit anterio-posteriorly shortened, laterally widened and vertically heightened neurocraniums. Analysis of the posterior and anterior frontal, sagittal and coronal sutures of early post-natal mutant mice revealed premature fusion. The sutures of mutant mice had accelerated osteoblast proliferation and increased expression of genes related to osteoblast differentiation, suggesting that bone formation at the sutures is locally increased in Pfeiffer syndrome. Of note, dramatically increased expression of core-binding transcription factor alpha subunit type 1 (Cbfa1) accompanied premature fusion, suggesting that Cbfa1 may be a downstream target of Fgf/Fgfr1 signals. This was confirmed in vitro, where we demonstrate that transfection with wild-type or mutant Fgfr1 induces Cbfa1 expression. The induced expression was also observed using Fgf ligands (Fgf2 and Fgf8). These studies provide direct genetic evidence that the Pro252Arg mutation in FGFR1 causes human Pfeiffer syndrome and uncovers a molecular mechanism in which Fgf/Fgfr1 signals regulate intramembraneous bone formation by modulating Cbfa1 expression.

Haploid loss of the tumor suppressor Smad4/Dpc4 initiates gastric polyposis and cancer in mice

The tumor suppressor SMAD4, also known as DPC4, deleted in pancreatic cancer, is a central mediator of TGF-beta signaling. It was previously shown that mice homozygous for a null mutation of Smad4 (Smad4-/-) died prior to gastrulation displaying impaired extraembryonic membrane formation and endoderm differentiation. Here we show that Smad4+/- mice began to develop polyposis in the fundus and antrum when they were over 6 - 12 months old, and in the duodenum and cecum in older animals at a lower frequency. With increasing age, polyps in the antrum show sequential changes from hyperplasia, to dysplasia, in-situ carcinoma, and finally invasion. These alterations are initiated by a dramatic expansion of the gastric epithelium where Smad4 is expressed. However, loss of the remaining Smad4 wild-type allele was detected only in later stages of tumor progression, suggesting that haploinsufficiency of Smad4 is sufficient for tumor initiation. Our data also showed that overexpression of TGF-beta1 and Cyclin D1 was associated with increased proliferation of gastric polyps and tumors. These studies demonstrate that Smad4 functions as a tumor suppressor in the gastrointestinal tract and also provide a valuable model for screening factors that promote or prevent gastric tumorigenesis.

Spinocerebellar ataxia type 2 in China: molecular analysis and genotype-phenotype correlation in nine families

Sixteen patients from nine Chinese families with spinocerebellar ataxia type 2 (SCA2) were heterozygous for a CAG repeat expansion in the SCA2 gene containing 37 to 56 repeats, whereas the normal alleles carried 14 to 28 repeats. One or two CAA triplets within the CAG tract were seen in normal, but not in the expanded alleles. A strong inverse correlation was established between the number of CAG repeats and the age of disease onset. SCA2 accounted for 12% of the known Chinese families with spinocerebellar ataxia.

Machado-Joseph disease in four Chinese pedigrees: molecular analysis of 15 patients including two juvenile cases and clinical correlations

Machado-Joseph disease (MJD) is an autosomal dominant neurodegenerative disorder associated with the expansion of a (CAG)n array in the MJD1 gene. We analyzed the sizes of the (CAG)n array using DNA samples from 61 members of four Chinese MJD families and 18 Chinese normal control subjects and confirmed that the (CAG)n array in 15 MJD chromosomes was expanded to 72-86 repeat units. There were no subjects with (CAG)n array sizes intermediate between those of normal and MJD affected groups. Meanwhile, we found a significant negative correlation between the age of onset of symptoms and (CAG)n array size. The largest (CAG)n array of 86 repeat units was in the youngest patient, whose age of onset was 5 years. The intergenerational increase in number of CAG repeat units was associated with the clinical phenomenon of anticipation.

Intergenerational instability of the CAG repeat of the gene for Machado-Joseph disease (MJD1) is affected by the genotype of the normal chromosome: implications for the molecular mechanisms of the instability of the CAG repeat

Machado-Joseph disease (MJD) is an autosomal dominant neurodegenerative disorder caused by unstable expansion of a CAG repeat in the MJD1 gene at 14q32.1. To identify elements affecting the intergenerational instability of the CAG repeat, we investigated whether the CGG/GGG polymorphism at the 3' end of the CAG repeat affects intergenerational instability of the CAG repeat. The [expanded (CAG)n-CGG]/[normal (CAG)n-GGG] haplotypes were found to result in significantly greater instability of the CAG repeat compared to the [expanded (CAG)n-CGG]/[normal (CAG)n-CGG] or [expanded (CAG)nGGG]/[normal (CAG)n-GGG] haplotypes. Multiple stepwise logistic regression analysis revealed that the relative risk for a large intergenerational change in the number of CAG repeat units (< -2 or > 2) is 7.7-fold (95% CI: 2.5-23.9) higher in the case of paternal transmission than in that of maternal transmission and 7.4-fold (95% CI: 2.4-23.3) higher in the case of transmission from a parent with the [expanded (CAG)n-CGG]/[normal (CAG)n-GGG] haplotypes than in that of transmission from a parent with the [expanded (CAG)n-CGG]/[normal (CAG)n-CGG] or [expanded (CAG)n-GGG]/[normal (CAG)n-GGG] haplotypes. The combination of paternal transmission and the [expanded (CAG)n-CGG]/[normal (CAG)n-GGG] haplotypes resulted in a 75.2-fold (95% CI: 9.0-625.0) increase in the relative risk compared with that of maternal transmission and the [expanded (CAG)n-CGG]/[normal (CAG)n-CGG] or [expanded (CAG)n-GGG]/[normal (CAG)n-GGG] haplotypes. The results suggest that an inter-allelic interaction is involved in the intergenerational instability of the expanded CAG repeat.