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Kun Chen

Publications and source records attributed to Kun Chen.

At least 19 recordsLinked to original sources
PubMed2026

Papillary Thyroid Carcinoma with Terminal Immune Exhaustion Phenotype Correlates with Increased Risk of Lymph Node Metastasis: An Exploratory Study Combining Flow Cytometry and TCGA.

BACKGROUND: Papillary thyroid carcinoma (PTC) is the most common thyroid malignancy, with lymph node metastasis (LNM) being a key predictor of recurrence and poor prognosis. Preoperative detection of LNM remains challenging due to the limitations of imaging modalities, leading to inadequate surgical resection in 20-30% of patients. While immune checkpoint molecules have been implicated in PTC progression, the heterogeneity of CD8+ T cell exhaustion subsets and their specific association with LNM remain poorly defined. In this study, we aimed to perform an exploratory characterization of the distinct immune landscape of PTC prone to LNM, with a focus on terminal immune exhaustion, in order to generate hypotheses for improved risk stratification and therapeutic strategies. METHODS: Fresh PTC tissues from 40 patients (22 LNM-positive and 18 LNM-negative) were analyzed via flow cytometry (FCM) to quantify immune cell subsets, inflammatory cytokines, and chemokines. Immunohistochemistry (IHC) validated CD45+ immune cell infiltration. Transcriptomic and clinical data from 448 PTC patients in The Cancer Genome Atlas (TCGA-PTC) cohort were used for bioinformatic analysis consistent with the observed phenotype, including Gene Set Variation Analysis (GSVA) of terminal exhaustion gene signatures. RESULTS: LNM-positive PTC exhibited a unique inflammatory milieu with significantly elevated IL-6, IL-1ra, CCL5, and IL-9 levels (all p < 0.05) in tumor interstitial fluid. FCM analysis revealed that LNM-positive PTC had increased infiltration of total CD45+ immune cells, CD3+ T cells, and CD3+CD8+ T cells (all p < 0.05). Critically, terminally exhausted PD-1hiTIM-3+ CD8+ T cells were significantly enriched in LNM-positive PTC (p = 0.022) and positively correlated with extrathyroidal extension (p = 0.044). Additionally, LNM risk was associated with increased CD4+ regulatory T (Treg) cell frequency (p = 0.023) and elevated CTLA-4 expression on CD4+ T cells (p = 0.047). In TCGA-PTC validation, the terminal exhaustion gene signature was predominantly enriched in LNM-positive (p < 0.0001) and advanced-stage PTC (p < 0.001) and strongly correlated with BRAF mutation (predominantly V600E) (p < 0.0001)-the most common oncogenic driver in aggressive PTC. CONCLUSIONS: Our findings suggest a terminal immune exhaustion phenotype (characterized by PD-1hiTIM-3+ CD8+ T cells and Treg enrichment) as a potential key feature associated with LNM-prone PTC. This phenotype shows consistency across clinical samples and TCGA datasets, linking BRAF mutation (predominantly V600E) to immune suppression and metastatic potential. These insights provide a novel exploratory immune-based biomarker for LNM risk stratification and support the potential of combining anti-PD-1/TIM-3 therapy with BRAF inhibitors for high-risk PTC, which should be confirmed in future studies.

lymph node metastasis↗
PubMed2024

Effect of inflammatory cytokines and plasma metabolome on OSA: a bidirectional two- sample Mendelian randomization study and mediation analysis.

BACKGROUND: Obstructive sleep apnea (OSA) is a common sleep disorder. Inflammatory factors and plasma metabolites are important in assessing its progression. However, the causal relationship between them and OSA remains unclear, hampering early clinical diagnosis and treatment decisions. METHODS: We conducted a large-scale study using data from the FinnGen database, with 43,901 cases and 366,484 controls for our discovery MR analysis. We employed 91 plasma proteins from 11 cohorts (totaling 14,824 participants of European descent) as instrumental variables (IVs). Additionally, we conducted a GWAS involving 13,818 cases and 463,035 controls to replicate the MR analysis. We primarily used the IVW method, supplemented by MR Egger, weighted median, simple mode, and weighted mode methods. Meta-analysis was used to synthesize MR findings, followed by tests for heterogeneity, pleiotropy, and sensitivity analysis (LOO). Reverse MR analysis was also performed to explore causal relationships. RESULTS: The meta-analysis showed a correlation between elevated Eotaxin levels and an increased risk of OSA (OR=1.050, 95% CI: 1.008-1.096; p < 0.05). Furthermore, we found that the increased risk of OSA could be attributed to reduced levels of X-11849 and X-24978 (decreases of 7.1% and 8.4%, respectively). Sensitivity analysis results supported the reliability of these findings. CONCLUSIONS: In this study, we uncovered a novel biomarker and identified two previously unknown metabolites strongly linked to OSA. These findings underscore the potential significance of inflammatory factors and metabolites in the genetic underpinnings of OSA development and prognosis.

Female↗
PubMed2007

Supramolecular assemblies of sulfonatocalixarenes with phenanthroline: factors governing capsule formation versus bilayer arrangements.

Four crystalline complexes were prepared by the inclusion complexation of the 1,10-phenanthrolinium ion (Phen) with p-sulfonatothiacalix[4]arene (TCAS) (2 from a solution at pH 1-2 and 4 from 1 M HCl) and with p-sulfonatocalix[5]arene (C5AS) (3 from a solution at pH 1-2 and 5 from 1 M HCl) upon varying the acidity of the solution. By combining the results obtained for complexes 2-5 with those for our previously reported complex (1), p-sulfonatocalix[4]arene (C4AS) complexed to Phen, it was revealed that p-sulfonatocalixarenes (CASs) form "bis-molecular" capsules (1, 2, and 3) around Phen at pH 1-2, whereas complexes 4 and 5 display distinct host-guest inclusion behavior at higher acid concentrations. The degree of compactness of the capsules increases with the enlargement of the calixarene cavity, which is affected significantly by both the penetration depth of Phen and the structure of the Phen dimer. Furthermore, the complexation behavior of TCAS/C5AS with Phen in 1 M DCl was investigated by using NMR spectroscopy, and was discussed in comparison with the previously reported results obtained from solutions at pH 2.0.

Journal Article↗
PubMed2006

Diagnosis of colorectal cancer using Raman spectroscopy of laser-trapped single living epithelial cells.

A single-cell diagnostic technique for epithelial cancers is developed by utilizing laser trapping and Raman spectroscopy to differentiate cancerous and normal epithelial cells. Single-cell suspensions were prepared from surgically removed human colorectal tissues following standard primary culture protocols and examined in a near-infrared laser-trapping Raman spectroscopy system, where living epithelial cells were investigated one by one. A diagnostic model was built on the spectral data obtained from 8 patients and validated by the data from 2 new patients. Our technique has potential applications from epithelial cancer diagnosis to the study of cell dynamics of carcinogenesis.

Adenocarcinoma↗
PubMed2006

The involvement of the antioxidant system in protection of desert cyanobacterium Nostoc sp. against UV-B radiation and the effects of exogenous antioxidants.

In this study, we found that UV-B radiation decreased photosynthetic activity and boosted lipid peroxidation of desert Nostoc sp., and exogenous chemicals (ascorbate acid (ASC), N-acetylcysteine (NAC), and sodium nitroprusside (SNP)) had obvious protective effects on photosynthesis and membranes under UV-B radiation. High-concentration SNP boosted the activities of antioxidant enzymes, but low-concentration SNP reduced the activities of antioxidant enzymes. Both NAC and ASC treatments of cells decreased activities of antioxidant enzymes. The results suggested that those chemicals possibly had different mechanisms of protection of algae cells against UV-B radiation. SNP might play double roles as a signal molecule in the formation of algae cell protection of Photosystem II under UV-B radiation and as a (reactive oxygen species) scavenger, while NAC and ASC might function as antioxidant reagents or precursors of other antioxidant molecules, which could protect cells directly against ROS initiated by UV-B radiation.

Antioxidants↗
PubMed2006

Health risks in infants associated with exposure to perfluorinated compounds in human breast milk from Zhoushan, China.

Recent studies have reported the ubiquitous distribution of perfluorinated compounds (PFCs), especially perfluorooctanesulfonate (PFOS) and perfluorooctanoic acid (PFOA), in wildlife and human whole blood or serum. In 2003 a solid phase extraction method was developed, which allowed the measurement of PFCs in human breast milk. In the present study, PFCs in samples of human breast milk from 19 individuals from Zhoushan, China, were analyzed by modifying a previously established method, based on weak-anion exchange extraction. PFOS and PFOA were the two dominant chemicals detected in all the milk samples. Concentrations of PFOS and PFOA ranged from 45 to 360 ng/L and 47 to 210 ng/L, respectively. The maximum concentrations of other PFCs were 100 ng/L for perfluorohexanesulfonate (PFHxS), 62 ng/L for perfluorononanoate (PFNA), 15 ng/L for perfluorodecanoate (PFDA) and 56 ng/L for perfluoroundecanoate (PFUnDA). Statistically significant correlations between various PFCs suggested a common exposure source to humans. No statistically significant correlation was found between concentrations of either PFOS or PFOA and maternal age, weight, or infant weight. Rate of consumption of fish was found to be positively correlated with PFNA, PFDA, and PFUnDA concentrations. Daily intake of PFOS for the child via breast milk with greater PFOS concentrations exceeded the predicted conservative reference dose in 1 of 19 samples, indicating that there may be a small potential risk of PFOS for the infants in Zhoushan via the consumption of breast milk.

Adult↗
PubMed2006

Melanoma differentiation-associated gene-7, MDA-7/IL-24, selectively induces growth suppression, apoptosis in human hepatocellular carcinoma cell line HepG2 by replication-incompetent adenovirus vector.

AIM: To investigate the effect of replication-incompetent adenovirus vector expressing MDA-7/IL-24 on tumor growth and apoptosis in human hepatocellular carcinoma (HCC) cell line HepG2 and normal liver cell line L02. METHODS: We constructed the recombinant replication-incompetent Ad.mda-7 virus vector and infected it into the human HCC cell line HepG2 and normal liver cell line L02. RT-PCR was performed to detect the mRNA expressing in cells. by ELISA was used to detect MDA-7/IL-24 protein expression in the culture supernatant. The effect of apoptosis induced by Ad.mda-7 was confirmed by Hoechst staining and flow cytometry assay with Annexin-V and PI staining. MTT assay was used to determine growth inhibition of HepG2 cells, and cell-cycle and hypodiploidy analyses were performed by flow cytometry. RESULTS: Recombinant replication-defective virus expressing MDA-7/IL-24 was constructed successfully. RT-PCR showed that the Ad.mda-7 could mediate the expression of the exogenous gene MDA-7/IL-24 into HepG2 and L02. The concentration of MDA-7/IL-24 protein in supernatant was 130 pg/mL and 110 pg/mL in Ad.mda-7-infected L02 and HepG2 cells, respectively. Ad.mda-7 infection obviously induced apoptosis (from 2.60%+/-0.72% to 33.6%+/-13.2%, P=0.00012) and growth suppression in HepG2 (inhibition ratio IR=68%) and an increase in the percentage of specific cancer cell types at the G2/M phase of the cell cycle (from 6.44% to 32.29%, P<0.01), but not in L02 cells. CONCLUSION: These results confirm selectively induction of apoptosis and growth suppression by the mda-7/IL-24 gene with replication-incompetent adenovirus vector in human hepatocellular carcinoma cell line HepG2.

Adenoviridae↗
PubMed2006

Genetic polymorphisms of the uridine diphosphate glucuronosyltransferase 1A7 and colorectal cancer risk in relation to cigarette smoking and alcohol drinking in a Chinese population.

BACKGROUND: The impact of uridine diphosphate glucuronosyltransferase 1A7 (UGT1A7) polymorphisms on genetic susceptibility to digestive system cancer has received close attention since the discovery by Guillemette, the polymorphisms of which may alter enzyme activity. To clarify the allele frequency distribution and its association with risk of colorectal cancer, a population-based case-control study was carried out in Chinese population. METHODS: A total of 140 patients with colorectal cancer and 280 cancer-free frequency-matched controls from a follow-up cohort population established in 1989, were enrolled. For the UGT1A7 polymorphisms analysis, polymerase chain reaction (PCR)-based genotyping techniques including semi-nested PCR, allele-specific PCR and PCR-restriction fragment length polymorphism (RFLP) were developed. RESULTS: The variant allele frequencies in patients and controls were 50.0% and 38.6%, respectively, which were significantly associated with risk of colorectal cancer (odds ratio [OR]: 1.59; 95% confidence interval [CI]: 1.19-2.13). For the variant genotypes analysis, *2/*2 and *3/*3 exhibited a significant association with risk of colorectal cancer (OR: 7.80, 95%CI: 2.66-22.87; OR: 3.47, 95%CI: 1.51-7.97, respectively). Stratification analysis indicated that in previous-current cigarette smoking (cigarette smoking history), current cigarette smoking (current cigarette smoking status), previous-current alcohol drinking (alcohol drinking history) or current alcohol drinking individuals (current alcohol drinking status), the risk developing colorectal cancer increased: OR (95%CI), 2.81 (0.97-8.11), 3.39 (1.19-9.67), 2.89 (0.99-8.46) and 3.14 (1.09-9.09), respectively. CONCLUSIONS: UGT1A7 polymorphisms may have a significant modifying effect on colorectal cancer risk, which may interact with environmental factors, cigarette smoking and alcohol drinking in colorectal carcinogenesis.

Aged↗
PubMed2006

Potential inplications of endogenous aldehydes in beta-amyloid misfolding, oligomerization and fibrillogenesis.

Aldehydes are capable of inducing protein cross-linkage. An increase in aldehydes has been found in Alzheimer's disease. Formaldehyde and methylglyoxal are produced via deamination of, respectively, methylamine and aminoacetone catalyzed by semicarbazide-sensitive amine oxidase (SSAO, EC 1.4.3.6. The enzyme is located on the outer surface of the vasculature, where amyloidosis is often initiated. A high SSAO level has been identified as a risk factor for vascular disorders. Serum SSAO activity has been found to be increased in Alzheimer's patients. Malondialdehyde and 4-hydroxynonenal are derived from lipid peroxidation under oxidative stress, which is also associated with Alzheimer's disease. Aldehydes may potentially play roles in beta-amyloid aggregation related to the pathology of Alzheimer's disease. In the present study, thioflavin-T fluorometry, dynamic light scattering, circular dichroism spectroscopy and atomic force microscopy were employed to reveal the effect of endogenous aldehydes on beta-amyloid at different stages, i.e. beta-sheet formation, oligomerization and fibrillogenesis. Formaldehyde, methylglyoxal and malondialdehyde and, to a lesser extent, 4-hydroxynonenal are not only capable of enhancing the rate of formation of beta-amyloid beta-sheets, oligomers and protofibrils but also of increasing the size of the aggregates. The possible relevance to Alzheimer's disease of the effects of these aldehydes on beta-amyloid deposition is discussed.

Aldehydes↗
PubMed2006

[Association of single nucleotide polymorphisms and haplotypes in DNA repair gene XRCC1 with susceptibility of breast cancer].

OBJECTIVE: To examine the contribution of the three most common single nucleotide polymorphisms (SNPs) in XRCC1 gene, C26304T, G27466A and G28152A, to susceptibility of breast cancer in Chinese Han population. METHODS: In this population-based case control study, 84 cases with breast cancer and 252 controls, matched to the cases in terms of habitation and age (5 years), were genotyped for the XRCC1 C26304T, G27466A and G28152A polymorphisms by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) methods. The haplotype distribution was estimated and compared by EH linkage software 1. 2. RESULT: The distribution of basic characteristics, such as age, alcohol drinking, the family history of malignancy in first and second relatives except cigarette smoking, were not significantly different between cases and controls. However, the percentage of ever or current smokers was significantly higher in cases (7.1%) than that in controls (2.0%). The distributions of allelotype and genotype of C26304T, G27466A and G28152A polymorphisms were also not significantly different between cases and controls. There was no significant association between the risk of breast cancer and these three SNPs of XRCC1 gene. The genetic linkage disequilibrium existed in these three polymorphic sites both in cases and controls, in which the CGG, CGA, CAG and TGG haplotypes were the most common. There was also no significant association of XRCC1 haplotype with risk of breast cancer. CONCLUSION: XRCC1 C26304T, G27466A and G28152A SNPs may not be associated with the susceptibility of breast cancer. The CGG, CGA, CAG and TGG haplotypes might be the most common haplotypes in Chinese Han population.

Adult↗
PubMed2006

[Association between genetic polymorphisms of metabolic enzymes and susceptibility of colorectal cancer].

OBJECTIVE: To investigate the association between CYP1A1, GSTM1, T1, UGT1A7 polymorphisms and colorectal cancer risk. METHODS: A case-control study of 140 patients with cancers and 343 health controls was conducted to investigate the role of CYP1A1, GSTM1, T1, UGT1A7 polymorphisms in colorectal cancer. Gene-gene interactions among CYP1A1, GSTM1, T1, UGT1A7 polymorphisms were detected by case-control study and case-only study. Genotypes of four genes polymorphisms were analyzed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and unconditional logistic regression was adopted to analyze the data. RESULTS: The CC, TC and CC genotypes of CYP1A1 T6235C significantly decreased the colorectal cancer risk as compared to TT genotype (OR = 0.493, 95% CI: 0.254-0.956, OR = 0.638, 95% CI: 0.427-0.952). GSTM1 and GSTT1 null genotype had no significant association with the increased risk of colorectal cancer while the mutant variants of UGT1A7 might increase the risk of colorectal cancer significantly (OR = 2.501, 95% CI: 1.456-4.296). The CORvalue for the gene-gene interactions between CYP1A1 variant and the null genotype of GSTT1, GSTM1-deleted and GSTT1-deleted genotype in the case-only design were 2.617 (95% CI: 1.015-6.752) and 3.935 (95% CI: 1.323-11.706), respectively. There was no significant interaction between CYP1A1 and GSTM1, CYP1A1 and UGT1A7. CONCLUSION: This study suggests that CYP1A1 and UGT1A7 variants might be associated with colorectal cancer. CYP1A1 and GSTM1 might interact on GSTT1 to influence the risk of colorectal cancer.

Cohort Studies↗
PubMed2006

[Molecular typing on Vibrio parahaemolyticus isolates from Hangzhou, China, during 2000-2002].

OBJECTIVE: To study the molecular epidemiology of Vibrio parahaemolyticus isolates from clinical and environmental samples collected in Hangzhou area during 2000 and 2002. METHODS: V. parahaemolyticus isolates from food-poisoning, sporadic diarrhea patients and seafood in market in Hangzhou during 2000 and 2002 were serotyped. From clinical isolates of serotype O3:K6 and environmental isolates of serotype O3:KUT, virulence genes, tdh and trh, were examined by PCR. Molecular typings [including ribotyping, random amplified polymorphic DNA analysis (RAPD), enterobacterial repetitive intergenic consensus PCR (ERIC-PCR)], were also performed. RESULTS: Among 13 food-poisoning outbreaks caused by V. parahaemolyticus, O3:K6 strains with tdh positive and trh negative were detected in 11 episodes (84.6%), and O4:K8 strains with tdh positive and trh negative were responsible for other 2 outbreaks (15.4%). In 34 V. parahaemolyticus isolates from sporadic diarrhea patients, O3:K6, O4:K8, and O1:KUT strains with tdh positive and trh negative were detected with proportions of 26.5% (9/34), 17.6% (6/34), and 38.2% (13/34), respectively, and other 6 strains were not able to be serotyped. Of 64 isolates from seafood in which both tdh and trh were negative except trh was positive in one O1:KUT strain, 37 belonged to 7 serotypes except O3:K6 or O4:K8, and 9 were not able to be serotyped. The fingprintings of ribotyping, ERIC-PCR, and RAPD showed that almost all of O3:K6 isolates from food-poisoning and sporadic diarrhea patients were genetically close to each other and there were obviously genetical difference between O3:K6 isolates from clinic and O3:KUT isolates from environment. CONCLUSION: There was a distinct serotype distribution between V. parahaemolyticus isolates from clinic patients and seafood. One group of close related V. parahaemolyticus O3:K6 strains with tdh positive and trh negative seemed to be prevailing in Hangzhou in those years.

China↗
PubMed2006

[Association between social psychological factors and depressive symptoms among healthcare workers].

OBJECTIVE: To explore the association between the effort-reward imbalance at work and depressive symptoms among healthcare workers. METHODS: The effort-reward imbalance at work was conceptualized in terms of the Chinese version of the effort-reward imbalance (ERI) model. Depressive symptoms were assessed by the Chinese version of the Center of Epidemiology Survey Depression (CES-D) scale. The data came from the cross-sectional survey of 1 179 healthcare workers aged between 18 and 73 employed in 6 affiliated hospitals of Zhejiang University. The questionnaire comprised questions on the effort-reward at work, over-commitment, the full CES-D scale of depression and a range of other characteristics. Univariate analyses were used with Spearman's correlation, Mann-Whitney test, Pearson chi(2) test and likelihood chi(2) test. Multivariate logistic regression analyses was used to discover factors associated with depressive symptoms. RESULTS: The prevalence of depressive symptoms among healthcare workers was 48.12% (95% CI: 45.08% to 51.16%). The prevalence of depressive symptoms among nurses was 52.40% (95% CI: 47.87% to 56.93%) higher than doctors' 44.70% (95% CI: 10.64% to 48.77%) with the significant difference (chi(2) = 6.077, P = 0.014). Positive associations were found between the high effort-low reward, level of work-related over commitment and depressive symptoms (OR = 1.859, 95% CI: 1.337 to 2.585; OR = 2.207, 95% CI: 1.656 to 2.942) among healthcare workers, respectively. CONCLUSION: The high effort-low reward and the work-related over-commitment have a negative impact on healthcare workers' health.

Adolescent↗
PubMed2006

[Adenovirus vector expressing MDA-7/IL-24 selectively induces growth arrests and apoptosis in human hepatocellular carcinoma cell lines independent of the state of p53 gene].

OBJECTIVE: To investigate the effect of melanoma differentiation associated gene-7/interleukin 24 (MDA/IL-24) on human hepatocellular carcinoma cell lines HepG2, MHCC97L and Hep3B and normal liver cell line L02 with a different p53 state. METHODS: The MDA-7/IL-24 gene was transfected into human hepatocellular carcinoma cell lines HepG2, MHCC97L and Hep3B and hepatocyte line L02 with a replication-incompetent adenovirus vector. The mRNA expression of MDA7/IL-24 in HepG2, MHCC97L, Hep3B and L02 cells was confirmed using RT-PCR. Protein expression was confirmed using ELISA assay. MTT assay and flow cytometry were used to study tumor cell proliferation and cell cycle in vitro. Hoechst and flow cytometry assay after annexin-V and PI staining were performed to indicate the apoptosis effect. RESULTS: Exogenous MDA-7/IL-24 gene was expressed in HepG2, MHCC97L, Hep3B and L02 cells. The protein product of MDA-7/IL-24 was confirmed in the supernatant. MTT assay and apoptosis test indicated MDA-7/IL-24 could induce growth suppression and apoptosis of HepG2, MHCC97L and Hep3B but could not in L02. Cell cycle test revealed MDA-7/IL-24 could block those cancer cells in G2/M but not in the normal cell L02. CONCLUSION: MDA-7/IL-24 selectively induces growth suppression and apoptosis in hepatocellular carcinoma lines HepG2, MHCC97L and Hep3B in vitro independent of the state of p53 gene but not in normal liver cell L02. This indicates MDA-7/IL-24 can be a perfect gene for gene therapy in hepatocellular carcinoma.

Adenoviruses, Human↗
PubMed2006

[Association between genetic polymorphisms in folate metabolic enzyme genes and colorectal cancer: a nested case-control study].

OBJECTIVE: To investigate the interrelationship of genetic polymorphisms in folate metabolic enzymes (MTHFRC677T, MTHFRA1298C, MTRA2756G and MTRRA66G) and their combinative effects with colorectal cancer (CRC). METHODS: A nested case-control study was designed and carried out. 140 CRC patients and 343 control subjects were included in this study. Polymorphisms of folate metabolic enzyme genes were genotyped by PCR-restriction fragment length polymorphism method. Risk of CRC was estimated by unconditional logistic model, and P value for interaction was calculated by likelihood test. RESULTS: The allele of MTR2756G showed a positive association with CRC (OR = 2.04, 95% CI = 1.22 - 3.40). Those with MTHFR1298AA and MTR 2756AG/GG genotypes had an elevated risk with CRC (OR = 2.57, 95% CI, 1.42 -4.65), and their combinative effect showed a significant association with CRC (P = 0.04). CONCLUSION: MTR2756G allele may be a risk factor of CRC, and interaction may exsit between polymorphisms of MTHFRA1298C and MTRA2756G. Further studies with larger sample and in different ethnic groups are needed.

5-Methyltetrahydrofolate-Homocysteine S-Methyltran↗
PubMed2006

[Study on the application of classification tree model in screening the risk factors of malignant tumor].

OBJECTIVE: To introduce the partitioning algorithm of classification tree model, and to explore the value of this data mining technique applied in data analysis of multifactorial diseases as malignant tumors. METHODS: Data was analyzed from a survey that conducted on 84 breast cancer patients and 273 cancer-free controls selected randomly in Jiashan county. The classification tree model was constructed using Exhaustive CHAID method and evaluated by the Risk statistics and the area under the ROC curve. RESULTS: 9 out of 105 effect risks factors were selected, in which career was the most important factor indicating that workers, teachers and retirees suffered much more risks than others. Nevertheless, the number of pregnancies, breast examination, reasons for menopause, age at menarche, intake of shrimp, crab, kipper, kelp and laver etc were also risk factors on breast cancer. However, physical exercise played different roles on different people. The Risk statistics of model was 0.174, and the area under the ROC curve was 0.872 which was significantly different from 0.5, suggesting that the classification tree model fit the actuality very well. CONCLUSION: The classification tree model could screen out the major affecting factors quickly and effectively and could also identify the cutting-points for continuous and ordinal variables, as well as revealing the complex interaction among the factors at many levels. This model might become a powerful tool to explore the complexities of the risks on diseases.

Algorithms↗
PubMed2006

[Number needed to be screened in a study: a novel measure for disease screening effect].

OBJECTIVE: To introduce the concept, methods for calculation and application of "number needed to be screened" (NNBS) in epidemiologic studies. METHODS: The concept of "number needed to treat" (NNT) was extended for disease screening strategies. For the purpose of illustration, the values of number needed to invite for screening (NNI) and number needed to be screened (NNBS) were calculated on the basis of the results from two randomized controlled screening trials--Nottingham randomized controlled trial of faecal-occult-blood screening for colorectal cancer and Swedish mammographic screening trial for breast cancer in two counties. RESULTS: In order to prevent one death from the colorectal cancer among local people aged from 45 to 74 during the 14 years of follow-up, the NNI and NNBS for faecal-occult-blood screening program were 1220 and 665, respectively. In addition, in order to prevent one death from breast cancer among local women aged 40-74 during 8 years of follow-up, the NNI and NNBS for mammographic screening program were 1961 and 1494, respectively. CONCLUSION: Compared with the traditional indices, NNBS can evaluate the overall effectiveness of a screening program in an intuitively understandable manner so as to facilitate the communication among medical researchers, health workers, health policy makers and the public.

Breast Neoplasms↗