Abnormal cortical functional connections in Alzheimer＇s disease： analysis of inter- and intra-hemispheric EEG coherence

To investigate inter- and intra-hemispheric electroencephalography (EEG) coherence at rest and during photic stimulation of patients with Alzheimer‘s disease (AD). Thirty-five patients (12 males, 23 females; 52-64 y) and 33 sex- and age-matched controls (12 males, 21 females; 56-65 y) were recruited in the present study. EEG signals from C3-C4, P3-P4, TS-T6 and O1-O2 electrode pairs resulted from the inter-hemispheric action, and EEG signals from C3-P3, C4-P4, P3-O1, P4-O2, C3-O1, C4-O2, TS-O1 and T6-O2 electrode pairs resulted from the intra-hemispheric action. The influence of inter- and intra-hemispheric coherence on EEG activity with eyes closed was examined, using fast Fourier transformation from the 16 sampled channels. The frequencies of photic stimulation were fixed at 5, l0 and 15 Hz, respectively. The general decrease of AD patients in inter- and intra-hemispheric EEG coherence was more significant than that of the normal controls at the resting EEG, with most striking decrease observed in the alpha-1 (8.0-9.0 Hz) and alpha-2 (9.5-12.5 Hz) bands. During photic stimulation, inter- and intra-hemispheric EEG coherences of the AD patients having lower values in the alpha (9.5-10.5 Hz) band than those of the control group. It suggests that under stimulated and non-stimulated conditions, AD patients had impaired inter- and intra-hemispheric functional connections, indicating failure of brain activation in alpha-related frequency.     

Effect of proximal femoral osteoporosis on cementless hip arthroplasty： A short-term clinical analysis

Objective： The aim of this retrospective investigation was to explore the influence of femoral osteoporosis on short-term curative effects ofcementless hip arthroplasty and to evaluate the femoral metaphyseal bone mineral density （BMD） for femoral osteoporosis in order to guide prosthesis choice and rehabilitation. Methods： We performed 127 total arthroplasty operations between June 1999 to February 2003 and investigated 49 cementless hip replacements with the Metalcancellous cementless Lubeck Ⅱ system being used in all hips. There were twenty men and twenty-nine women whose mean age at the time of the operation was 60 years （range, 52-81 years）. The patients were divided into osteoporosis or normal groups according to the femoral metaphyseal BMD measured preoperatively. The average duration of follow-up was 30 months （range, 8-52 months）. We evaluated all of the patients from a clinical standpoint with use of a standard-terminology questionnaire with respect to the short-term curative effects and patients＇ satisfaction. Hip pain status and functional ability were important indicators of treatment efficacy. Results： Harris hip score and patients＇ satisfaction in femoral osteoporosis patients who underwent noncemented hip arthroplasty were lower （P=0.004, P=0.03） while the incidence of thigh pain was higher （P=0.03） than the patients with non-osteoporosis. Conclusion： The higher incidence of pain, as well as the decrease in function experienced by the patients in osteoporosis group, supports the case that cementless arthroplasty is not a better choice for those patients and that we had better select prosthesis based on the femoral metaphyseal BMD.     

Diffusion tensor imaging of the brain in patients with Alzheimer＇s disease and cerebrovascular lesions

Background： Recent autopsy study showed a high incidence ofcerebrovascular lesions in Alzheimer＇s disease （AD）. To assess the impact of cerebrovascular pathology in AD, we used diffusion tensor imaging （DTI） to study AD patients with and without cerebrovascular lesions. Materials and Methods： Conventional and DTI scans were obtained from 10 patients with probable AD, 10 AD/V patients （probable AD with cerebrovascular lesions） and ten normal controls. Mean diffusivity （D） and fractional anisotropy （FA） values of some structures involved with AD pathology were measured. Results： D value was higher in AD patients than in controls in hippocampus and the cingulate gyrus. In AD/V patients, increased D value was found in the same structures and also in the thalamus and basal ganglia compared to controls. There was a significant difference of D value between AD and AD/V patients. FA value reduced in the white matter of left inferior temporal gyrus and in the bilateral middle cingulate gyrus in patients with AD/V compared with controls. The MMSE （mini-mental state examination） score significantly correlated with FA value in the right hippocampus （r=0.639, P〈0.019）, in the right anterior cingulate gyrus （r=0.587, P〈0.035） and in left parahippocampal gyrus （r=0.559, P〈0.047）. Conclusion： Cerebrovascular pathology had stronger impact on the D value than the AD pathology alone did. Elevated D value in thalamic and basal ganglia may contribute to cognitive decline in AD/V patients. Reduced FA values in AD/V patients may indicate that cerebrovascular pathology induced more severe white matter damage than the AD pathology alone did.     

Association of Graves’ disease and Graves’ ophthalmopathy with the polymorphisms in promoter and exon 1 of cytotoxic T lymphocyte associated antigen-4 gene

INTRODUCTION Graves’ disease (GD) is an autoimmune diseasecharacterized clinically by hyperthyroidism, diffusegoiter, Graves’ ophthalmopathy (GO) and the pres-ence of TSH (thyroid-stimulating hormone) receptorautoantibodies. GD is a multifactorial disease thadevelops as the result of a complex interaction be-tween genetic susceptibility genes and environmentafactors. Multiple genetic factors are believed to in-fluence the autoimmunity evident in GD, but a firmgenetic basis for GD …     

Relationships between endothelial nitric oxide synthase gene polymorphisms and osteoporosis in postmenopausal women

Objective: To investigate the relationships between endothelial nitric oxide synthases (eNOS) G894T and 27 bp-variable number tandem repeat (VNTR) gene polymorphisms and osteoporosis in the postmenopausal women of Chinese Han nationality. Methods: In the present study, 281 postmenopausal women from Xi'an urban area in West China were recruited, and divided into osteoporosis, osteopenia, and normal groups according to the diagnostic criteria of osteoporosis proposed by World Health Organization (WHO). The bone mineral density (BMD) values of lumbar vertebrae and left hips were determined by QDR-2000 dual energy X-ray absorptiometry. Blood samples were tested for plasma biochemical indicators including testosterone, estradiol, calcitonin, osteocalcin, and procollagen type I amino-terminal propeptide by enzyme-linked immunosorbent assay (ELISA), tartrate-resistant acid phosphatase by spectrophotometric method, and the content of nitric oxide by Griess method. Genome DNA was extracted from whole blood, and G894T polymorphism of eNOS gene was analyzed by using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method and 27 bp-VNTR polymorphism of eNOS gene was genotyped by PCR method. Then the relationships between genotypes and biochemical indicators, genotypes and osteoporosis, and haplotypes and osteoporosis were analyzed. Results: The average BMD values of the femoral neck, ward's triangle and lumbar vertebrae 1～4 (L1～L4) in the subjects with T/T genotype in eNOS G894T locus were significantly higher than those in the subjects with G/T and G/G genotypes (P<0.05). The average BMD of the femoral neck in the subjects with a/a genotype of eNOS 27 bp-VNTR locus was evidently higher than that in the subjects with b/b genotype (P<0.05). The plasma testosterone and osteocalcin concentrations in the subjects of eNOS G894T G/T genotype were evidently higher than those in the subjects of other genotypes (P<0.05); the plasma estradiol concentration in the subjects of eNOS 27 bp-VNTR a/a genotype was obviously higher than that in the subjects of b/b genotype (P<0.01). eNOS G/G homozygous frequencies in osteoporosis women, osteopenia women, and normal women were 85.37%, 76.38%, and 83.87%, respectively (P＞0.05). 0% osteoporosis woman, 0.79% osteopenia women, and 3.23% normal women were eNOS a/a homozygous (P<0.05). The frequencies of eNOS 27 bp-VNTR a allele were 5.33% in the osteoporosis group, 10.24% in the osteopenia group, and 16.13% in the normal group (P<0.05, odds ratio (OR)=0.29, 95% confidence interval (CI)=0.11～0.77), suggesting that a/a genotype and a allele might have protective effects on osteoporosis. The haplotype analysis showed that G-b was 87.7% (214/244) in the osteoporosis group (P<0.05, OR=2AS, 95% CI=1.18～5.18). G-a was 5.3% (13/244) in the osteoporosis group (P<0.05, OR=0.29, 95% CI=0.11～0.77). G-b was a risk factor for osteoporosis, and G-a a protective factor. Conclusion: eNOS G894T G/T genotype influenced the plasma testosterone and osteocalcin concentrations, and T/T genotype influenced BMD. eNOS 27 bp-VNTR a/a genotype increased plasma estradiol concentration to have a protective effect on osteoporosis.     

Integrating Gene Ontology and Blast to predict gene functions

A GoBlast system was built to predict gene function by integrating Blast search and Gene Ontology (GO) annotations together. The operation system was based on Debian Linux 3.1, with Apache as the web server and Mysql database as the data storage system. FASTA files with GO annotations were taken as the sequence source for blast alignment, which were formatted by wu-formatdb program. The GoBlast system includes three Bioperl modules in Perl:a data input module, a data process module and a data output module. A GoBlast query starts with an amino acid or nucleotide sequence. It ends with an output in an html page, presenting high scoring gene products which are of a high homology to the queried sequence and listing associated GO terms beside respective gene poducts. A simple click on a GO term leads to the detailed explanation of the specific gene function. This avails gene function prediction by Blast. GoBlast can be a very useful tool for functional genome research and is available for free at http://bioq.org/goblast.     

Elementary Teachers＇ Perceptions About Implementation of Inclusive Education

The Disabilities Education Act was introduced in June, 1997 in the Turkish Education System. The Act states that schools have a duty to educate children with disabilities in general education classrooms. All children with disabilities should be educated with non-disabled children at their own age and have access to the general education curriculum. The philosophy of inclusive education aims at helping all children learn in regular classrooms. Children learn at their own pace and style within a nurturing learning environment because schools are important places for children to develop friendships and learn social skills. Children with and without disabilities learn together and from each other in inclusive classes. On the other hand, when children attend classes that reflect the similarities and differences of people in the real world, they learn to appreciate diversity. The aim of this study is to examine the perceptions of teachers about implementation of inclusive education in elementary schools. In order to collect data for this study, a questionnaire which consisted of eight open-ended questions was developed and administered to 66 elementary school teachers. The teachers worked at primary schools and taught 1-5 grades. They were asked to write their opinions and experiences about the implementation of inclusive education in the elementary schools. Primary school teachers generally have a positive attitude about inclusive education and its philosophical and psychological foundation. However, they express that they encounter some difficulties in implementing inclusive classrooms. A crowded classroom is a main obstacle to obtain desired objectives in educational activities. The levels of students＇ disability are related to effectiveness of classroom management. The effectiveness of inclusive education depends on not only the teachers＇ quality but also the school administrators＇. Some superintendents assess the effectiveness of teachers in inclusive and regular classrooms in the same way.     

Relation of uric acid levels to aortic root dilatation in hypertensive patients with and without metabolic syndrome

Objective:Uric acid(UA) is considered to be a powerful predictor of cardiovascular risk and hyperuricemia might be involved in the metabolic syndrome(MS).This study aims to investigate the relation between UA levels and aortic root dilatation.Methods:A total of 348 hypertensive patients [age(67.5±9.8) years] with or without MS were included in the study.The aortic root diameters at the aortic annulus,the sinuses of Valsalva,the sinotubular junction,and the proximal part of the ascending aorta were measured using a two-dimensional(2D) echocardiography.Serum UA levels were also measured for all patients.Results:A high UA level is independently associated with aortic root diameters at the sinuses of Valsalva(P=0.001) and the proximal ascending aorta(P0.0001) in the hypertensive patients without MS.In contrast,aortic root diameters were not significantly related to UA levels in the hypertensive patients with MS.Furthermore,increased UA levels were associated with an increased risk for aortic root dilatation in the patients without MS(sex-adjusted hazard ratio 1.75,95% confidence intervals(CI) 1.27-2.41),but not in those with MS.Conclusions:This study demonstrated an independent relationship between the aortic root dimensions and increased levels of serum UA in the hypertensive patients without MS.Further understanding of the mechanisms underlying these associations may allow a clearer interpretation of the potential value of specific urate-lowering treatment on cardiovascular disease.     

Association between infection of different strains of <Emphasis Type="Italic">Porphyromonas gingivalis</Emphasis> and <Emphasis Type="Italic">Actinobacillus actinomycetemcomitans</Emphasis> in subgingival plaque and clinical parameters in chronic periodontitis

Objective： The aim of this study was to investigate subgingival infection frequencies ofPorphyromonas gingivalis and Actinobacillus actinomycetemcomitans strains with genetic variation in Chinese chronic periodontitis （CP） patients and to evaluate its correlation with clinical parameters. Methods： Two multiplex polymerase chain reaction （PCR） assays were developed to detect the 16SrDNA, collagenase （prtC） and fimbria （fimA） genes of P. gingivalis and the 16SrDNA, leukotoxin （lktA） and fimbria-associated protein （fap） genes ofA. actinomycetemcomitans in 60 sulcus samples from 30 periodontal healthy subjects and in 122 subgingival plaque samples from 61 patients with CP. The PCR products were further T-A cloned and sent for nucleotide sequence analysis. Results： The 16SrDNA,prtC andfimA genes ofP. gingivalis were detected in 92.6%, 85.2% and 80.3% of the subgingival plaque samples respectively, while the 16SrDNA, lktA andfap genes ofA. actinomycetemcomitans were in 84.4%, 75.4% and 50.0% respectively. Nucleotide sequence analysis showed 98.62%-100% homology of the PCR products in these genes with the reported sequences. P. gingivalis strains with prtC＋/fimA＋ and A. actinomycetemcomitans with lktA＋ were predominant in deep pockets （〉6 mm） or in sites with attachment loss 〉5 mm than in shallow pockets （3-4 mm） or in sites with attachment loss 〈2 mm （P〈0.05）. P. gingivalis strains withprtC＋/fimA＋ also showed higher frequency in gingival index （GI）=3 than in GI=1 group （P〈0.05）. Conclusion： Infection ofP. gingivalis with prtC＋/fimA＋ and A. actinomycetemcomitans with lktA＋ correlates with periodontal destruction of CP in Chinese. Nonetheless P. gingivalis fim4, prtC genes and A. actinomycetem- comitans lktA gene are closely associated with periodontal destruction, while A. actinomycetemcomitansfap gene is not.     

A qualitative investigation of trainees＇ adjustment in Japan：A case study of trainees from Indonesia

In Japan, there is a residence status known as “the trainee”. This is the status for residents who undertake “activities to learn and acquire the technology, skills, or knowledge at public or private organizations in Japan”. With the introduction of the Industrial Training Program in 1993, trainees have been permitted to extend their stay in Japan for education and employment purposes up to a maximum of three years. This study aims to investigate the adjustment styles of trainees and to consider the changes in their attitudes toward Japan in the course of this adjustment. Six male Indonesian trainees （mean age=23.83） were invited to a semi-structured interview. They were employed at the same factory, involved in the manufacture of car components, and were trainees in their first-, second-, and third-years. The interview mainly focused on the trainees＇ Japanese language skills, the changes in their images of Japan or Japanese people, the communication between them and their Japanese colleagues, and the difficulties they encountered during their stay in Japan. The results revealed that there were clear differences between the first, second, and third trainees. As the trainees＇ Japanese language skills improved, their communication with the Japanese colleagues increased. Subsequently, they developed more positive images of Japan and Japanese people and hoped to have more informal communication with Japanese people.     

伴发ATTR型淀粉样沉积的骨关节炎患者的临床和生物学特征分析(英文)简

Objective： Our aim was to investigate clinical and laboratory characteristics of osteoarthritic patients who had amyloid deposition in their knee joints. Methods： Synovial membranes were obtained from 36 patients with knee osteoarthritis （OA） who underwent joint replacement surgery. From this sample, the diagnosis of amyloid was deter- mined by Congo red staining, which demonstrated apple-green birefringence under a polarized microscope. All syn- ovial membranes were immunohistochemically characterized for the expressions of amyloid immunoglobulin light chain （AL-K and AL-,k）, serum amyloid-A （SAA）, amyloidogenic transthyretin （ATTR）, and amyloidogenic 152- microglobulin （A152M）. Matrix-assisted laser desorption-ionizaton/time of flight mass spectrometry （MALDI-TOF MS） was used to analyze transthyretin （TTR） isoforms in the serum of each patient. Results： Nine cases （25%） were found to be amyloid-positive. Immunohistochemicaliy, eight cases （88.9%） had ATTR deposition, and one sample （11.1%） was shown to be AL-K-positive. MALDI-TOF MS identified that the TTR in the serum of the patients was unmodified wild-type TTR, TTR-Cys-S-S-Cys, and TTR-Cys-S-S-CysGly. The age at surgery and the disease duration were sig- nificantly higher in the ATTR-positive group than in the ATTR-negative group. Knee score and function score were significantly lower in the ATTR-positive group than in the ATTR-negative group. Conclusions： Amyloid deposition in synovial membranes of OA patients was found to be ATTR and AL-K. TTR in the serum of the patients was unmodified wild-type TTR together with two isoforms. The high age at surgery, long disease duration, and a deteriorated knee function were associated with ATTR amyloid deposition in the osteoarthritic knee joints.     

Effect of enalapril on plasma homocysteine levels in patients with essential hypertension

Objective:To investigate the effect of enalapril on plasma homocysteine(Hcy) levels and the association of methylenetetrahydrofolate reductase(MTHFR) C677T polymorphism with the changes of Hcy levels in response to enalapril among patients with essential hypertension.Methods:A total of 130 patients with mild-to-moderate essential hypertension were enrolled and enalapril was orally administered at a dose of 10 mg/d for eight weeks.Plasma Hcy levels were measured by denaturing high-performance liquid chromatography(DHPLC) at baseline and after eight weeks of treatment.Genotyping of MTHFR C677T polymorphism was performed by TaqMan probe technique.Results:Compared with baseline,plasma Hcy levels did not change significantly after eight weeks(P=0.81).Stratified by baseline Hcy levels,a significant increase in plasma Hcy levels(P=0.02) among those with Hcy 10 μmol/L was observed,in contrast to no significant changes in plasma Hcy levels(P=0.54) among those with Hcy ≥10 μmol/L.No significant association was observed between MTHFR C677T polymorphism and changes in Hcy levels in response to enalapril.Conclusions:Enalapril may cause an increase in plasma Hcy levels among the hypertensives with low baseline Hcy levels.There was no significant association between MTHFR C677T genotypes and changes in Hcy levels in response to enalapril among subjects with essential hypertension.     

Evaluation of the effect and profitability of gene-assisted selection in pig breeding system

Objective:To evaluate the effect and profitability of using the quantitative trait loci (QTL)-linked direct marker (DR marker) in gene-assisted selection (GAS). Methods: Three populations (100, 200, or 300 sows plus 10 boars within each group) with segregating QTL were simulated stochastically. Five economic traits were investigated, including number of born alive (NBA), average daily gain to 100 kg body weight (ADG), feed conversion ratio (FCR), back fat at 100 kg body weight (BF) and intramuscular fat (IMF). Selection was based on the estimated breeding value (EBV) of each trait. The starting frequencies of the QTL's favorable allele were 0.1, 0.3 and 0.5, respectively. The economic return was calculated by gene flow method. Results: The selection efficiency was higher than 100% when DR markers were used in GAS for 5 traits. The selection efficiency for NBA was the highest, and the lowest was for ADG whose QTL had the lowest variance. The mixed model applied DR markers and obtained higher extra genetic gain and extra economic returns. We also found that the lower the frequency of the favorable allele of the QTL, the higher the extra return obtained. Conclusion: GAS is an effective selection scheme to increase the genetic gain and the eco- nomic returns in pig breeding.     

Stable response of axisymmetric two-phase water-saturated soil

Biot's dynamic consolidation equations and Hankel transform were used to derive the integral solutions of stress and displacement for axisymmetric harmonic excitations in the two-phase saturated soil with subjacent rock-stratum. The influence of the coefficient of permeability and loading frequency on the soil displacement at the ground surface were studied. The results showed that higher loading frequency led to more dynamic characteristics; and that the effect of the soil permeability was more obvious at higher frequencies.     

Patients＇ quality of life after laparoscopic or open cholecystectomy

Objective: This study was aimed at evaluating and comparing the quality of life in patients who underwent laparo-scopic and open cholecystectomy for chronic cholecystolithiasis. Methods: The study included 25 patients with laparoscopic cholecystectomy (LC group) and 26 with open cholecystectomy (OC group). The quality of life was measured with the Gastrointestinal Quality of Life Index (GLQI) preoperatively, thereafter regularly at 2, 5, 10 and 16 weeks after the operation. Results: The mean preoperative overall GLQI scores were 112.5 and 110.3 in LC and OC group respectively (P>0.05). In the LC group, the mean overall GLQI score reduced slightly to 110.0 two weeks after the operation (P>0.05). The LC group showed significant improvement in overall score and in the aspects of symptomatology, emotional and physiological status from 5 to 16 weeks postoperatively. In the OC group, the GLQI score reduced to 102.0 two weeks after surgery (P<0.05). Significant reductions were shown in the aspects of symptomatology, physiological and social status. The GLQI scores returned to the preoperative level of 115.6 ten weeks after the operation (P>0.05). The patients experienced significant improvements of GLQI sixteen weeks after OC operation (P<0.01-0.05). Within the 10 postoperative weeks, the LC group had significantly higher GLQI scores than the OC group (P<0.05). Conclusions: LC can improve the quality of life postoperatively better and more rapidly than OC. The assessment of quality of life assessment is a valid method for measuring the effects of surgical treatment.     

Polymorphisms in genes involved in folate metabolism as maternal risk factors for Down syndrome in China

Objective: To explore the relationship between genetic polymorphisms in methylenetetrahydrofolate reductase (MTHFR), methionine synthase reductase (MTRR), the central enzymes in folate metabolism that affects DNA methylation and synthesis, and the risk of Down syndrome in China. Methods: Genomic DNA was isolated from the peripheral lymphocytes of 64 mothers of children with Down syndrome and 70 age matched control subjects. Polymerase chain reaction and restriction fragment length polymorphism were used to examine the polymorphisms of MTHFR 677C→T, MTRR 66A→G and the relationship between these genotypes and the risk of Down syndrome was analyzed. Results: The results show that the MTHFR 677C→T polymorphism is more prevalent among mothers of children with Down syndrome than among control mothers, with an odds ratio of 3.78 (95% confidence interval (CI), 1.78～8.47). In addition, the homozygous MTRR 66A→G polymorphism was independently associated with a 5.2-fold increase in estimated risk (95% CI, 1.90～14.22). The combined presence of both polymorphisms was associated with a greater risk of Down syndrome than the presence of either alone, with an odds ratio of 6.0 (95% CI, 2.058～17.496).The two polymorphisms appear to act without a multiplicative interaction. Conclusion: MTHFR and MTRR gene mutation alleles are related to Down syndrome, and CT, TT and GG gene mutation types increase the risk of Down syndrome.     

Parent and teacher perceptions of students＇ general scholastic abilities： Effects on involvement and communication

Parents＇ and teachers＇ perceptions of students＇ general scholastic abilities, such as being able to complete their school work, retain what they learn, and achieve sufficiently compared to other students at their ages, were analyzed for how well they predict parents＇ forms of involvement in their children＇s education and teachers＇ forms of communication to parents. Data were collected from parents and teachers in two Title I, public middle schools in a large, urban city in the southwest. Parent involvement and teacher communication practices were measured using the ＂school and family partnerships survey＂. Parents＇ and teachers＇ perceptions of students＇ general scholastic abilities were measured using a teacher-rating version of the ＂perceived competence scale for children＂. Linear regression analyses revealed that parents＇ perceptions did not predict their involvement, nor did teachers＇ perceptions predict their amount of communication as reported by parents. Although parents＇ and teachers＇ perceptions did not predict involvement in this study, perceptions of children＇s general academic abilities should be further explored in relation to family-school partnerships. The results suggest that involvement in middle school occurs in ways distinctive from elementary school. Therefore, improved instruments are needed to more accurately measure parent involvement and teacher communication at grade levels beyond elementary school.     

Methylenetetrahydrofolate reductase C677T polymorphism predicts response and time to progression to gemcitabine-based chemotherapy for advanced non-small cell lung cancer in a Chinese Han population

Objective:The aim of this study was to evaluate the association between the methylenetetrahydrofolate reductase(MTHFR) C677T excision repair cross-complementation group 1(ERCC1) genetic polymorphisms and the clinical efficacy of gemcitabine-based chemotherapy in advanced non-small cell lung cancer(NSCLC).Methods:A total of 135 chemonaive patients with unresectable advanced NSCLC were treated with gemcitabine/platinum regimens.The polymorphisms of MTHFR C677T,ERCC1 C8092A,and ERCC1 C118T were genotyped using the TaqMan methods.Results:The overall response rate was 28.9%.Patients with MTHFR CC genotype had a higher rate of objective response than patients with variant genotype(TT or CT)(41.2% versus 19.1%,P=0.01).Median time to progression(TTP) of patients with MTHFR CC genotype was longer than that of patients with variant genotype(7.6 months versus 5.0 months,P=0.003).No significant associations were obtained between ERCC1 C118T and C8092A polymorphisms and both response and survival.Conclusions:Our data suggest the value of MTHFR C677T polymorphism as a possible predictive marker of response and TTP in advanced NSCLC patients treated with gemcitabine/platinum.     

University students＇ conceptions about the concept of gene： Interest of historical approach

Concepts of genetics are often difficult to teach, specifically the central concept of gene. Even the scientists disagree when defining this concept. This paper investigates university students＇ understanding about the gene and its functions. The results show the dominance of two conceptions of the gene： the Neoclassical model and the Mendelian model. The existence of hybrid conceptions and the lack of the modern model show that students are unable to mobilize the knowledge taught in biology. These results suggest to improve the teaching methods of genetics, for instance, by developing activities that bring students face to face with their conceptions.