An updated meta-analysis on the association of TGF-β1 gene promoter -509C/T polymorphism with colorectal cancer risk

AimPublished data on the association between transforming growth factor-β1 (TGF-β1) gene promoter-509C/T polymorphism and colorectal cancer (CRC) risk are inconsistent and inconclusive. To derive a more precise estimation of this association, a meta-analysis was carried out.MethodsMeta-analysis was performed to evaluate reported studies of the relationship between TGF-β1 gene promoter-509C/T polymorphism and colorectal cancer risk using fixed-effects model and random-effects model.ResultsWe observed an increased colorectal cancer risk among subjects carrying TGF-β1 gene promoter-509CC + CT genotype (odds ratio (OR) = 1.18%, 95% confidence interval (95% CI): 1.06–1.32) using 4440/6785 cases/controls in total population. We observed an increased risk of the TGF-β1 gene promoter -509CC, CT and CC + CT polymorphisms for colorectal cancer in population-based study (OR = 1.36, 95% CI: 1.19–1.56, OR = 1.18, 95% CI: 1.03–1.34 and OR = 1.26, 95% CI: 1.12–1.43, respectively) in stratified analysis. We observed an increased colorectal risk among CC and CC + CT carriers in European and American population (OR = 1.22, 95% CI: 1.04–1.43 and OR = 1.18, 95% CI: 1.02–1.38, respectively). We also observed an increased risk of colon cancer among subjects carrying CC + CT genotype (OR = 1.31, 95% CI: 1.05–1.63).ConclusionsThe present meta-analysis results suggest that TGF-β1 gene promoter -509C allele variant is a possible risk factor for developing colorectal cancer. Recommendations for further studies include pooling of individual data to verify results from the study and to facilitate evaluation of multigenic effects and detailed analysis of effect modification by environmental and lifestyle factors.     

No association of monocyte chemoattractant protein-1 −2518 A/G polymorphism with the risk of primary glomerulonephritis in the Polish population

Various studies have indicated that chemokines such as monocyte chemotactic protein-1 (MCP-1) play an important role in the pathogenesis of primary glomerulonephritis (GN) and other glomerular diseases. Moreover, patients with primary GN display aberrant galactosylation of the O-linked carbohydrate moieties of IgA. Therefore, we analysed the distribution of the functional MCP-1 −2518 A > G (rs 1024611) and 1 beta 1,3-galactosyltransferase (C1GalT1) 1365 A > G (rs1047763) polymorphic variants in patients with primary GN (n = 144) and controls (n = 437) in a sample of the Polish population. We did not find a significant difference in the prevalence of the MCP-1 −2518 A > G and C1GalT1 1365 A > G polymorphisms in patients with primary GN and healthy individuals. Odds Ratio (OR) for GN patients with the MCP-1 −2518 GG genotype was 0.869 (95% CI = 0.410–1.840, P = 0.7130), and OR of the −2518 GG and −2518AG genotypes was 1.004 (95% CI = 0.689–1.464, P = 0.9836). OR for C1GalT1 1365AA genotype was 0.484 (95% CI = 0.181–1.293, P = 0.1402) and OR of the 1365AA and 1365AG genotypes was 0.839 (95% CI = 0.573–1.228, P = 0.3651). We also did not observe a difference in the distribution of alleles between patients and controls. The MCP-1 −2518 G allelic OR was 0.976 (95% CI = 0.725–1.314, P = 0.8744). The OR for the C1GalT1 1365A allele was 0.816 (95% CI = 0.596–1.118, P = 0.205). Moreover, there was no significant association between the MCP-1 −2518 A > G and C1GalT1 1365 A > G genotypes with different morphological types of primary GN or clinical manifestations. Our observations indicate that the MCP-1 −2518 A > G and C1GalT1 1365 A > G polymorphisms might not be a risk factor in the incidence of primary GN in the Polish population.     

No association between IL-1β -511 C/T polymorphism and the risk of duodenal ulcer: A meta-analysis of 4667 subjects

Epidemiological studies have evaluated the association between IL-1β -511 C/T polymorphism and duodenal ulcer (DU) risk. However, the results remain conflicting. The aim of this study was to perform a meta-analysis to investigate a more authentic association between IL-1β -511 C/T polymorphism and DU. Systematic searches of electronic databases Embase, PubMed and Web of Science as well as hand searching of the references of identified articles and the meeting abstracts were performed. Study selection, data abstraction and study quality evaluation were independently conducted in duplicate. Statistical analyses were performed using software Stata 11.0. The pooled odds ratios (ORs) with 95% confidence intervals (95% CIs) were performed. Publication bias was tested by Begg's funnel plot and Egger's regression test. A total of 14 studies including 1887 cases and 2780 controls were included in our final meta-analysis. There was no evidence of significant association between IL-1β -511 C/T polymorphism and DU (for T allele vs. C allele: OR=0.93, 95% CI=0.82-1.06; for T/T vs. C/C: OR=0.83, 95% CI=0.64-1.08; for dominant model: OR=0.93, 95% CI=0.80-1.07; and for recessive model: OR=0.87, 95% CI=0.69-1.11). Significant association was found in all genetic models for the PB subgroup and sensitivity analyses. In conclusion, our meta-analysis suggests that there was no evidence of a significant association between IL-1β -511 C/T polymorphism and DU with or without Helicobacter pylori infection, whereas a significant association was found by sensitivity analyses which showed a protective effect of the T allele against DU risk.     

Lack of association between cyclooxygenase 2−765G/C gene polymorphism and breast cancer risk in Ahvaz, west-south Iran

Cyclooxygenases are key enzymes in conversion of arachidonic acid into prostaglandin H2. Cyclooxygenase-2 (COX-2) increases prostaglandins in neoplastic tissue. COX-2 has important roles in cell proliferation cancers, angiogenesis, and alzheimer. COX-2 is up-regulated in several types of cancer, and it is hypothesized that COX-2 expression may be genetically influenced. Our main objective was to evaluated the association of polymorphism COX-2 with risk of breast cancer in khouzestan province, and the second objective of the study was to evaluate the association with biochemistry parameters. This study consisting of 150 patients with breast cancer and 120 normal DNA was extracted from the white blood cells. Polymorphism cox2 gene was detected by polymerase chain reaction according to the standard methods. The profile lipids and estrogen were measured in two groups by standard methods. Chi square analysis showed that there was no association between breast cancer risk and COX-2 ?765G>C genotype and alleles. Also, no association were observed between ?765G>C polymorphism and biochemistry parameters. A multiple logistic regression model with cox2 genotypes and LDL and HDL as covariates revealed that there is no significant association between cox2 genotypes and risk of breast cancer, but higher values of LDL and HDL significantly increase risk of breast cancer.     

Associations of MMP-2 −1306 C/T and MMP-9 −1562 C/T polymorphisms with breast cancer risk among different populations: a meta-analysis

The meta-analysis aims to investigate association between two matrix metalloproteinases (MMPs) polymorphisms (MMP-2 ?1306 C/T and MMP-9 ?1562 C/T) and breast cancer risk. Eligible studies were retrieved from relevant databases, based on predefined criteria. Quality assessment was evaluated by Newcastle–Ottawa Scale. Odds ratio (OR) with its 95% confidence interval (CI) was selected as the effect size for the meta-analysis. As a result, 13 studies were included. MMP-2 ?1306 C/T polymorphism was not significantly associated with breast cancer risk under all genetic models (P > 0.05). However, subgroup analysis stratified by ethnicity showed a significant association between MMP-2 ?1306 C/T polymorphism and reduced breast cancer risk in Asian populations under allelic model (OR 0.60, 95% CI 0.39–0.90, P = 0.02) and dominant model (OR 0.55, 95% CI 0.34–0.89, P = 0.02). MMP-9 ?1562 C/T polymorphism was significantly related to increased breast cancer risk under allelic model (OR 1.50, 95% CI 1.06–2.12, P = 0.02), additive model (OR 1.45, 95% CI 1.02–2.05, P = 0.04) and recessive model (OR 1.54, 95% CI 1.13–2.12, OR 0.007). A significant association between MMP-9 ?1562 C/T polymorphism and increased breast cancer risk in Caucasian was detected under most of the genetic models (P < 0.05). MMP-2 ?1306 C/T polymorphism might be significantly associated with reduced breast cancer risk in Asian, while MMP-9 ?1562 C/T might be closely related to increased breast cancer risk, especially in Caucasian.     

The ?159C/T polymorphism in the CD14 gene and the risk of asthma: a meta-analysis

The -159C/T polymorphism in the CD14 gene has been implicated in susceptibility to asthma, but a large number of studies have reported inconclusive results. The aim of this study is to investigate the association between the -159C/T polymorphism in the CD14 gene and the risk of asthma by meta-analysis. We searched Pubmed, Embase, CNKI database, Wanfang database, Weipu database, and Chinese Biomedical database, covering all publications (last search been performed on April 20, 2010). Statistical analysis was performed by using the softwares Revman 4.2 and STATA 10.0. A total of 17 case-control studies in 17 articles (4,246 cases and 3,631 controls) were included in this meta-analysis. There was no association between this polymorphism and asthma risk in combined analyses (odds ratio (OR)?=?0.86 and 95% confidence interval (95% CI)?=?0.72-1.02, P?=?0.09 for TC?+?TT vs. CC). In the subgroup analysis by age, ethnicity, and atopic status, no significant associations of asthma risks were obtained from age groups, ethnic groups, and atopic groups for TC?+?TT vs. CC comparison. For atopic population, significant decreased atopic asthma risks were found among Asian population (OR?=?0.69, 95% CI 0.52-0.92, P?=?0.01) and children population (OR?=?0.69, 95% CI 0.54-0.89, P?=?0.0004) for TC?+?TT vs. CC comparison. This meta-analysis suggests that CD14 is a candidate gene for atopic asthma susceptibility. The -159C/T polymorphism may be a protective factor for atopic asthma in Asian and children. More studies are needed to validate these associations.     

Association between the MMP-9−1562 C>T polymorphism and the risk of stroke: a meta-analysis

Matrix metalloproteinase (MMP)-9 so far is identified as extremely large and complicated MMP family member. Recently, dozens of studies have explored the association between a promoter polymorphism (?1562 C>T) in MMP-9 and stroke susceptibility. However, the conclusions of these studies still remain equivocal. Therefore, our current meta-analysis was conducted to investigate whether or not the MMP-9 promoter polymorphism is related to the risk of stroke. Electronic databases (PubMed, EMBASE, Web of Science, Cochrane Library and the Chinese Biomedical Literature Database) were searched to obtain all the available studies investigating this polymorphism and stroke from inception to October 2013. Overall and subgroup analyses were rigorously conducted after data extraction. Pooled odds ratio (OR) corresponding to 95 % confidence interval (CI) were estimated. The statistical analysis was performed using Review Manager 5.2. Totally, seven studies involving 1,624 cases and 1,525 controls were identified. The overall results suggested that there was no association of the C?1562T variant on stroke risk under the T allele versus C allele [OR _{T vs. C} 0.98, 95 % CI (0.84, 1.15), P = 0.84], the dominant model [OR _{TT+TC vs. CC} 0.95, 95 % CI (0.81, 1.13), P = 0.59], the recessive model [OR _{TT vs. TC+CC} 1.55, 95 % CI (0.86, 2.81), P = 0.15], the homozygote comparison [OR _{TT vs. CC} 1.48, 95 % CI (0.82, 2.68), P = 0.20] and the heterozygote comparison [OR _{TC vs. CC} 0.93, 95 % CI (0.78, 1.10), P = 0.38]. In the subgroup analyses by ethnicity, age, stroke type and source of controls, no significant relations were observed in any genetic models. Our results indicated that MMP-9?1562 C>T polymorphism was not a risk factor for stroke. Further studies should focus on gene–gene and gene–environment interactions, and provide a more convincing explanation for this association.     

E-cadherin gene 3′-UTR C/T polymorphism in Turkish patients with nephrolithiasis

Nephrolithiasis is a complex disease and many gene polymorphisms have been associated with stone formation. In this study we aimed to investigate another possible relationship between E-cadherin gene (CHD1) 3′-UTR C/T polymorphism and calcium oxalate nephrolithiasis in the Turkish population. Study population was composed of 143 patients with nephrolithiasis and 158 control subjects. CHD1 3′-UTR C/T polymorphism was analysed using polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP) technique. Genotype distribution of the investigated polymorphism was not deviated from Hardy–Weinberg equilibrium (HWE) in patients and control subjects (P > 0.05). C allele frequency was 85.7 and 85.1% in patients and controls, respectively (P = 0.836). Genotype distributions of the CHD1 3′-UTR C/T polymorphism among patients were also not significantly different from those among control subjects (P = 0.636). Our results showed that there is no association between the CHD1 gene 3′-UTR C/T polymorphism and nephrolithiasis in our population.     

Possible association of the allele status of the CS.7/HhaI polymorphism 5′ of the CFTR gene with postnatal female survival

Cystic fibrosis (CF) patients show a high degree of linkage disequilibrium between the CF transmembrane conductance regulator (CFTR) gene and polymorphisms 5′ of that gene. To determine whether the region 5′ of CFTR contains biologically important sequences, the allele frequencies of six CFTR-linked polymorphisms (metH/MspI, XV-2c/TaqI, CS.7/HhaI, KM19/PstI, MP6-d9/MspI, J44/XbaI) were determined in 417 randomly selected elderly individuals (over 75 years of age) from the Czech population. The elderly individuals were considered “escapees” of strong selective pressures that had operated during their lifetime, prior to the introduction of modern health care since 1950. The pooled allele frequencies of the analyzed marker polymorphisms in the elderly did not significantly differ from published data. However, when analyzed by sex, the allele frequencies of markers CS.7/HhaI and KM19/PstI differed significantly (P < 0.05) between elderly females and males. The allele frequencies of the six polymorphisms were then determined in 646 newborns and 345 young adults of reproductive age; these individuals were selected in a similar manner and drawn from the same population. In these control groups, the studied marker polymorphisms exhibited no statistically significant differences between sexes and/or between individuals of the same sex, only between different age groups. A gradual relative increase in the frequency of allele “2” of marker CS.7/HhaI was observed from newborn females to elderly women, the overall difference in allele frequencies of this marker polymorphism between newborn females and elderly women reaching statistical significance (P < 0.05). Interestingly, allele “2” is the major constituent of the extended “B-haplotype”, which is in strong linkage disequilibrium with common CF alleles. Taken together, our data suggest that the region spanning markers CS.7 and KM19 is associated with a genetic factor that influences postnatal female survival, providing a possible mechanism for increasing the frequency of particular mutations in the adjacent CFTR gene. Received: 30 January 1996 / Revised: 16 December 1996     

A systematic review and meta-analysis of the association of transforming growth factor β receptor I 6A/9A gene polymorphism with ovarian cancer risk

Abstract

Ovarian cancer is the leading cause of cancer-related death in women. This meta-analysis was conducted to evaluate the association of transforming growth factor β receptor I (TβR-I) 6A/9A gene polymorphism with ovarian cancer risk. The association literatures were identified from PubMed and Cochrane Library on 1 October 2013, and eligible reports were recruited and synthesized. Four reports were recruited into this meta-analysis for the association of TβR-I 6A/9A gene polymorphism with ovarian cancer risk. 6A allele and 6A/6A genotype of TβR-I were associated with the ovarian cancer risk (6A: OR?=?1.24, 95% CI: 1.02–1.51, p?=?0.03; 6A/6A: OR?=?2.30, 95% CI: 1.01–5.22, p?=?0.05). However, TβR-I 9A/9A genotype was not associated with the risk of ovarian cancer (OR?=?0.82, 95% CI: 0.66–1.02, p?=?0.08). In conclusion, TβR-I 6A allele and 6A/6A genotype are associated with the ovarian cancer risk. However, more studies should be performed to confirm this relationship in the future.     

Association between α1-antichymotrypsin signal peptide −15A/T polymorphism and the risk of Alzheimer’s disease: a meta-analysis

No consensus has been recently reached at the relationship between the α1-antichymotrypsin (ACT) signal peptide −15A/T polymorphism and Alzheimer’s disease (AD) risk. Thus, our study aimed to better assess this association by performing a meta-analysis, including 4,212 cases and 4,039 controls from 29 studies. Odds ratios (ORs) with the 95% confidence interval (CI) were used to assess the strength of relationship between ACT −15A/T polymorphism and AD risk. Overall, a borderline statistically significant association was detected under recessive model comparison in all subjects (AA vs. AT+TT: OR 1.12, 95% CI 1.01–1.25, P = 0.04). But in subgroup analysis by ethnicity, no significant association was found in Caucasians, Asians, or Africans. Moreover, after exclusion of one study which affect the heterogeneity, the ACT A allele and AA genotype were statistically associated with late-onset AD (LOAD) risk (AA vs. TT: OR 1.25, 95% CI 1.06–1.48, P = 0.007, A vs. T: OR 1.12, 95% CI 1.03–1.21, P = 0.008), especially in Caucasians. In conclusion, our study suggests that the common α1-antichymotrypsin signal peptide −15A/T polymorphism may not be a major risk factor for AD. However, the polymorphism is capable of increasing LOAD risk.     

−509C>T polymorphism in the TGF-β1 gene promoter,impact on the hepatocellular carcinoma risk in Chinese patients with chronic hepatitis B virus infection

Hepatocellular carcinoma (HCC) is one of the most common malignant tumors worldwide. The risk for developing HCC increases with severity of inflammation and fibrosis. Transforming growth factor-β1 (TGF-β1) is most frequently upregulated in tumor cells. The most studied −509C>T polymorphism of TGF-β1 gene has been associated with colorectal, gynecologic, and lung cancers. To assess whether this polymorphism in TGF-β1 gene is associated with susceptibility to and/or clinicopathologic characteristics of HBV-related HCC, a total of 575 patients with chronic HBV infection and 299 healthy volunteers with no evidence of recent or remote HBV infection were prospectively enrolled. The patients were divided into two groups: those without (n = 196) and those with HCC (n = 379). These 379 HCC patients with chronic HBV infection were designated as cases, the remaining 196 patients without HCC and 299 healthy volunteers served as disease and healthy controls, respectively. −509C>T polymorphism in the TGF-β1 gene promoter was studied using restriction fragment-length polymorphism. In addition, tumor tissues of liver (n = 60) were obtained from the studied HCC patients for measurement of TGF-β1 mRNA expression levels. We also assessed the plasma TGF-β1 levels of HBV patients without (n = 94) or with HCC (n = 136) and healthy subjects (n = 120). In our study group, the risk of HCC in Chinese patients with HBV infection was significantly lower with the TT genotypes than in those with the CC genotypes at position −509 of TGF-β1 gene (P = 0.01). In addition, in the case group, patients with the CC genotype had a statistically significant higher median plasma TGF-β1 or liver tumor tissue TGF-β1 mRNA level compared with the individuals with the TT genotype. However, in a subsequent analysis of the association between this polymorphism and clinicopathological characteristics including tumor number, size, grade, stage, and invasiveness, there was no significant difference in both the distribution of genotype or allelic frequency within HCC patients, indicating that −509C>T exchange in TGF-β1 gene may play an important role in the occurrence, not the progression of HBV-related HCC through influencing plasma concentrations of TGF-β1 or TGF-β1 mRNA expression of liver tumor tissue.     

Association analysis of the E-selectin 98G > T polymorphism and the risk of childhood ischemic stroke

Genes related to platelet and arterial endothelial function have been recently considered as independent risk factors for stroke. We aimed to analyze a relationship between the E‐selectin 98G > T polymorphism and stroke in children and to observe the transmission of E‐selectin alleles from heterozygous parents to their affected children. We studied 59 children after stroke, 112 parents, and 87 healthy children. The E‐selectin 98G > T polymorphism was analyzed with the polymerase chain reaction‐restriction fragment length polymorphism (PCR‐RFLP) method. The frequency of the 98T allele in patients was almost twofold lower than in controls (5.1% vs. 9.8%, p = 0.145, odds ratios (OR) = 0.49) as well as carriers of the 98T allele (19.5% in controls vs. 8.5% in cases, p = 0.067, OR = 0.38). The G allele of the E‐selectin 98G > T polymorphism was more frequently transmitted to the children after stroke compared to the T allele (68% vs. 32%). In conclusion, we did not confirm the relationship between the 98G > T polymorphism of the E‐selectin gene and childhood ischemic stroke. There is still a need for further studies. Copyright © 2010 John Wiley & Sons, Ltd.     

The functional −94 insertion/deletion ATTG polymorphism in the promoter region of NFKB1 gene increases the risk of sporadic colorectal cancer

Objective: To investigate the allele and genotype frequencies of NFKB1 ?94 ins/del ATTG (rs28720239) polymorphism and to evaluate the association between the polymorphism and colorectal cancer (CRC) risk in Malaysian population. Methods: Genomic DNA was extracted from the peripheral blood samples of 474 study subjects, which consisted of 237 histopathologically confirmed CRC patients and an equal number of cancer-free controls. The NFKB1 ?94 ins/del ATTG (rs28720239) polymorphism was genotyped using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method and confirmed by DNA sequencing. The association between the polymorphic genotypes and CRC risk was evaluated by deriving odds ratios (ORs) and 95% confidence intervals (CIs) using unconditional logistic regression analysis. Results: The frequencies of wildtype (del/del), heterozygous (del/ins) and variant (ins/ins) genotypes in CRC patients were 31.7%, 53.6% and 14.8%, respectively, while those in cancer-free controls were 35.0%, 58.2% and 6.8%, respectively. The frequency of the variant genotype was significantly higher in cases compared to controls (P < 0.01). Evaluation of the risk association of the polymorphic genotypes revealed that the variant genotype could contribute to a significantly increased risk of CRC (OR = 2.42, 95% CI = 1.24–4.73, P < 0.01). Conclusions: The variant allele of NFKB1 ?94 ins/del ATTG (rs28362491) polymorphism is associated with higher risk of sporadic CRC in Malaysian population.     

G-protein β3 subunit gene C825T polymorphism in patients with vesico-ureteric reflux

The C825T polymorphism in the GNB3 gene encoding a β3 subunit from heterotrimeric G-proteins correlates strongly with the variation in activity of the G-proteins. It has so far been associated with a variety of medical conditions, but has not been tested for association with vesico-ureteric reflux (VUR). Primary VUR is a condition of genetic origin that appears to be inherited in an autosomal dominant mode, but with reduced penetrance. The constitutional change in G-protein-mediated cell signaling associated with the C825T polymorphism might be one of the factors that participate in the development of VUR by modifying the effect of still unknown mutated gene(s). A significant difference in genotype frequencies (χ² = 7.38, P = 0.025, df = 2) was observed between patients with primary VUR (33 CC homozygotes, 40 CT heterozygotes, 12 TT homozygotes) and healthy controls with no medical record of reflux (114 CC homozygotes, 88 CT heterozygotes, 18 TT homozygotes). This result suggests that the C825T polymorphism of the GNB3 gene might be associated with the development of VUR.     

No association between the SOCS-1 −1478CA/del polymorphism and ulcerative colitis in Turkish subjects

Suppressor of cytokine signaling (SOCS)-1 is an essential regulator of many cytokine signaling pathways, including those upregulated in the inflamed colonic mucosa of patients with ulcerative colitis. We sought to investigate whether the functional SOCS-1 ?1478CA>del polymorphism is associated with UC susceptibility and its disease phenotype in a Turkish clinical sample. A total of 104 subjects were enrolled in a case–control study (52 UC cases and 52 controls). The SOCS-1 ?1478CA>del polymorphism was genotyped using a polymerase chain reaction-restriction fragment length polymorphism (PCR–RFLP) method. The odds ratio of the del allele for UC relative to the CA allele was not significant (OR = 1.04, 95 % CI 0.59–1.82, P = 0.88). These results did not change after adjustment for age and sex in multivariable regression analysis (OR = 1.07, 95 % CI 0.42–1.69, P = 0.73). When the SOCS-1 ?1478CA>del polymorphism was analyzed among UC patients according to continuous disease and non-continuous disease, the del allele was not associated with disease recurrence (OR = 1.56, 95 % CI 0.78–4.56, P = 0.83). Furthermore, when we divided UC patients into two groups according to a previous history of colectomy, we found no significant effect of the del allele (OR = 1.94, 95 % CI 0.55–5.61, P = 0.91). Taken together, these findings suggest that SOCS-1 ?1478CA>del polymorphism does not contribute to UC susceptibility and its disease phenotype in Turkish subjects.     

Photosynthetic/photorespiratory characteristics of C3−C4 intermediate species

The extent of photorespiration, the inhibition of apparent photosynthesis (APS) by 21% O₂, and the leaf anatomical and ultrastructural features of the naturally occurring C₃–C₄ intermediate species in the diverse Panicum, Moricandia, and Flaveria genera are between those features of representative C₃ and C₄ plants. The greatest differences between the photosynthetic/photorespiratory CO₂ exchange characteristics of the C₃–C₄ intermediates and C₃ plants occur for the parameters which are measured at low pCO₂ (i.e., the CO₂ compensation concentration and rates of CO₂ evolution into CO₂-free air in the light). The rates of APS by the intermediate species at atmospheric pCO₂ are similar to those of C₃ plants.The mechanisms which are responsible for reducing photorespiration in the C₃–C₄ intermediate species are poorly understood, but two proposals have been advanced. One emphasizes the importance of limited C₄ photosynthesis which reduces O₂ fixation by ribulose 1,5-bisphosphate carboxylase/oxygenase, and, thus, reduces photorespiration by a CO₂-concentrating mechanism, while the other emphasizes the importance of the internal recycling of photorespiratory CO₂ evolved from the chloroplast/mitochondrion-containing bundle-sheath cells. There is no evidence from recent studies that limited C₄ photosynthesis is responsible for reducing photorespiration in the intermediate Panicum and Moricandia species. However, preliminary results suggest that some, but not all, of the intermediate Flaveria species may possess a limited C₄ cycle. The importance of a chlorophyllous bundle-sheath layer in the leaves of intermediate Panicum and Moricandia species in a mechanism based on the recycling of photorespiratory CO₂ is uncertain.Therefore, although they have yet to be clearly delineated, different strategies appear to exist in the C₃–C₄ intermediate group to reduce photorespiration. Of major importance is the finding that some mechanism(s) other than Crassulacean acid metabolism or C₄ photosynthesis has (have) evolved in at least the majority of these terrestrial intermediate species to reduce the seemingly wasteful metabolic process of photorespiration.Abbreviations APS apparent (net) photosynthesis - CAM Crassulacean acid metabolism - CE carboxylation efficiency - T CO₂ compensation concentration - IRGA infrared gas analysis - P_i orthophosphate - PEP phosphoenolpyruvate - RuBP ribulose 1,5-bisphosphate Published as Paper No. 7383, Journal Series, Nebraska Agricultural Experiment Station.     

Association of the mitochondrial DNA 5178 A/C polymorphism with serum lipid levels in the Japanese population

As one approach to exploring whether the mitochondrial DNA 5178 adenine/cytosine (mt5178 A/C) polymorphism is associated with atherosclerosis, we genotyped 461 healthy Japanese individuals and studied the relationship of mt5178 A/C genotypes to serum lipid levels. Blood specimens were obtained after at least a 12-h fasting period from the subjects. The mt5178 A/C was genotyped by the polymerase chain reaction/restriction fragment length polymorphism method. The relative frequency of mt5178 A was 41.6% (192/461) and of mt5178 C was 58.4% (269/461). After adjustments for age and body mass index, the high-density lipoprotein cholesterol concentration in males carrying mt5178 A was significantly higher than that in males carrying mt5178 C ( P=0.026). The tryglyceride (TG) concentration in females carrying mt5178 A was significantly lower than that in females carrying mt5178 C ( P=0.012). This difference in the TG level between the two genotypes was more evident in postmenopausal females than in premenopausal females. Mt5178 A seems to have an antiatherogenic effect. This is the first genetic epidemiological report on the association of mt5178 A/C polymorphism with serum lipid levels in the Japanese population.     

Meta-analysis of transforming growth factor β receptor I 6A/9A gene polymorphism and breast cancer risk: the picture remains murky

Abstract

Breast cancer is currently the second most common cancer worldwide and the most frequent malignant tumor among women. However, the exact contribution of various allelic alterations remains unclear. This meta-analysis was conducted to evaluate the association of the transforming growth factor β receptor I 6A/9A (TβR-I 6A/9A) gene polymorphism with breast cancer risk. Relevant studies were identified from PubMed and Cochrane Library on 1 October 2013, and eligible reports were recruited and synthesized. Eleven reports that included a total of 12 studies were recruited into this meta-analysis for the association of the TβR-I 6A/9A gene polymorphism and breast cancer risk. The results indicated that overall the TβR-I 6A allele was associated with breast cancer risk (OR?=?1.33, 95% CI: 1.02–1.73, p?=?0.04). However, the TβR-I 6A/6A and 9A/9A genotypes were not associated with an increased risk of developing breast cancer (6A/6A: OR?=?1.71, 95% CI: 0.95–3.08, p?=?0.07; 9A/9A: OR?=?0.82, 95% CI: 0.66–1.02, p?=?0.08). In the Caucasian population, no such association could be established. In conclusion, the TβR-I 6A allele might represent a risk factor for breast cancer risk, but significantly larger data sets from a larger number of studies, including studies that allow ethnicity, subgroup analysis and environmental impact evaluation, are required to maximize statistical significance and meta-analysis robustness.     

Does childhood experience of attention-deficit hyperactivity disorder symptoms increase sleep/wake cycle disturbances as measured with actigraphy in adult patients with bipolar disorder?

ABSTRACT

Childhood attention-deficit hyperactivity disorder (ADHD) is a common precursor of adult bipolar disorders (BD). Furthermore, actigraphy studies demonstrate that each disorder may be associated with abnormalities in sleep and activity patterns. This study investigates whether the presence or absence of self-reported childhood experiences of ADHD symptoms is associated with different sleep and activity patterns in adults with BD. A sample of 115 euthymic adult patients with BD was assessed for childhood ADHD symptoms using the Wender Utah Rating Scale (WURS) and then completed 21 days of actigraphy monitoring. Actigraphic measures of sleep quantity and variability and daytime activity were compared between BD groups classified as ADHD+ (n = 24) or ADHD? (n = 91), defined according to established cutoff scores for the WURS; then we examined any associations between sleep–wake cycle parameters and ADHD dimensions (using the continuous score on the WURS). Neither approach revealed any statistically significant associations between actigraphy parameters and childhood ADHD categories or dimensions. We conclude that the sleep and activity patterns of adult patients with BD do not differ according to their self-reported history of ADHD symptoms. We discuss the implications of these findings and suggest how future studies might confirm or refute our findings.