High Efficiency UV-Emission at 345 nm from InAlGaN Light-Emitting Diodes

Optical and electrical properties of 340 nm-band bright UV-light emitting diodes (LEDs) were compared between In0.03Al0.20Ga0.77N and other active regions. Single peaked and high efficiency ultraviolet (UV) emission at 345 nm from In0.03Al0.20Ga0.77N LEDs is achieved under continuous current injection conditions. Any significant broadening and peak shift of the electroluminescence (EL) spectrum were not observed. We attribute such a good properties to using of high quality InAlGaN-quaternary active layer. The EL intensity of the InAlGaN quaternary-based LED showed more one order of magnitude higher intensity than that of AlGaN and GaN based LEDs. Additionally, The I-L characteristics of the InAlGaN quaternary-based LED showed a linearly increasing of intensity with increasing of injection current density, that is also observed for InGaN based LEDs. This shows the recombination efficiency of the InAlGaN-based LED is as much as that of InGaN based LEDs. From these results InAlGaN quaternary is expected to be a promising material for UV LEDs and LDs.

Fabrication of p-n junction with Mg-doped wide bandgap InAlGaN for application to UV emitters

Mg-doped quaternary InAlGaN is very attractive for use as p-side layers of 300-nm band ultraviolet (UV) light-emitting diodes (LEDs) or laser diodes (LDs), because high hole conductivity is expected to obtain for wide bandgap (~4 eV) InAlGaN with Mg-doping. We fabricated p-n junction diode consisting of Mg-doped In0.02Al0.28Ga0.70N and Si-doped Al0.25Ga0.75N, and demonstrated intense UV emission under CW current injection at room temperature. The rising voltage in I-V curve was around 3.8 V and the breakdown voltage was as high as 10 V. Single peaked intense emission was observed at 340 nm from around InAlGaN/AlGaN p-n junction area without any deep level emission. Also we found that Ni/Au electrode directly fabricated on Mg-doped InAlGaN is useful. From these results, Mg-doped InAlGaN is considered to be very attractive for use as p-side layer of UV-LEDs or LDs.

Association of polymorphisms of BTN2A1 and ILF3 with myocardial infarction in Japanese individuals with or without hypertension, diabetes mellitus or chronic kidney disease

Recent evidence suggests that genetic variants that confer susceptibility to myocardial infarction (MI) may differ between men and women or between individuals with or without conventional risk factors for MI. We previously showed that rs6929846 of BTN2A1 and rs2569512 of ILF3 were significantly associated with MI in Japanese individuals. In the present study, we examined the associations of rs6929846 of BTN2A1 or rs2569512 of ILF3 to MI among individuals stratified by the absence or presence of hypertension, diabetes mellitus (DM) and chronic kidney disease (CKD). The study population was comprised of 5689 unrelated Japanese individuals, including 1626 subjects with MI and 4063 controls with or without hypertension, DM or CKD. Multivariable logistic regression analyses with adjustment for covariates revealed that rs6929846 of BTN2A1 was significantly associated with MI in individuals with (P=0.0001; odds ratio, 1.49) or without (P=1.6x10-7; odds ratio, 2.32) hypertension; in individuals with (P=0.0002; odds ratio, 1.65) or without (P=8.1x10-7; odds ratio, 1.76) DM; and in individuals without CKD (P=6.0x10-11; odds ratio, 2.03), but not in those with CKD. Similar analyses revealed that rs2569512 of ILF3 was significantly associated with MI in individuals with (P=0.0041; odds ratio, 1.26) or without (P=0.0051; odds ratio, 1.78) hypertension; in individuals with (P=0.0200; odds ratio, 1.46) or without (P=0.0174; odds ratio, 1.43) DM; and in individuals with (P=0.0011, odds ratio, 1.47) or without (P=0.0237; odds ratio, 1.34) CKD. Results suggested that the association of rs6929846 in BTN2A1 with MI was more apparent in low-risk individuals than in high-risk individuals, whereas the association of rs2569512 in ILF3 with MI was not influenced by the absence or presence of hypertension, DM or CKD. Stratification of subjects based on hypertension, DM or CKD may thus be informative in order to achieve personalized prevention of MI with the use of genetic information.

Association of polymorphisms of BTN2A1 and ILF3 with myocardial infarction in Japanese individuals with different lipid profiles

Dyslipidemia is an important risk factor for myocardial infarction (MI). We previously showed that gene polymorphisms associated with MI differed among individuals with different lipid profiles. We also showed that rs6929846 of BTN2A1 and rs2569512 of ILF3 were significantly associated with MI in Japanese individuals. In the present study, we examined the relationship between rs6929846 of BTN2A1 or rs2569512 of ILF3 and MI in individuals with low or high serum concentrations of triglycerides, high density lipoprotein (HDL) cholesterol, or low density lipoprotein (LDL) cholesterol, respectively. The study population comprised 5513 unrelated Japanese individuals, including 1537 subjects with MI and 3976 controls. Multivariable logistic regression analyses with adjustment for covariates revealed that rs6929846 of BTN2A1 was significantly associated with MI in individuals with low (P=3.1 x 10-5; odds ratio, OR=1.66) or high (P = 1.1 x 10⁻⁶; OR = 2.09) triglycerides; in individuals with low (P = 0.0082; OR = 1.75) or high (P = 2.0 x 10⁻⁹; OR = 1.85) HDL cholesterol; and in individuals with low (P = 3.2 x 10⁻⁷; OR = 1.75) or high (P = 2.8 x 10⁻⁵; OR =2.18) LDL cholesterol. Similar analyses revealed that rs2569512 of ILF3 was significantly associated with MI in individuals with low (P = 0.0066; OR = 1.47) or high (P = 0.0013; OR = 1.88) triglycerides; in individuals with low (P = 0.0059; OR = 1.96) or high (P = 0.0020; OR = 1.51) HDL cholesterol; and in individuals with low (P = 0.0004, OR = 1.62) LDL cholesterol, but not in those with high LDL cholesterol. The results suggest that the relationship between rs6929846 of BTN2A1 or rs2569512 of ILF3 and MI is influenced by the serum concentrations of HDL and LDL cholesterol, respectively. Stratification of subjects according to lipid profiles may thus be useful for the personalized prevention of MI based on genetic information.

Association of a polymorphism of BTN2A1 with chronic kidney disease in individuals with or without hypertension or diabetes mellitus

Hypertension and diabetes mellitus are important risk factors for chronic kidney disease (CKD). We previously showed that the C→T polymorphism (rs6929846) of BTN2A1 was significantly associated with myocardial infarction. The purpose of the present study was to examine an association of rs6929846 of BTN2A1 with CKD in individuals with or without hypertension or diabetes mellitus, thereby contributing to the personalized prevention of CKD in such individuals separately. The study population comprised 7,542 unrelated individuals, including 2,289 subjects with CKD [estimated glomerular filtration rate (eGFR) <60 ml/min/1.73 m(2)] and 5,253 controls (eGFR ≥60 ml/min/1.73 m(2)) with or without hypertension or diabetes mellitus. The Chi-square test, a multivariable logistic regression analysis with adjustment for covariates, as well as a stepwise forward selection procedure revealed that the C→T polymorphism (rs6929846) of BTN2A1 was significantly associated with CKD in normotensive individuals, in diabetic individuals and in individuals with hypertension and diabetes mellitus, or without either condition, with the T allele representing a risk factor for CKD. Stratification of subjects based on hypertension or diabetes mellitus may thus be important in order to achieve personalized prevention of CKD with the use of genetic information.

114 BOVINE EMBRYO-MATERNAL RECOGNITION MAY OCCUR EARLIER IN AI THAN IN EMBRYO TRANSFER (ET)

Embryo-maternal recognition is known to be mediated by the trophoblast and/or its secretory product during the preimplantation period. However, it was recently proposed that embryo-maternal recognition (along with the maternal immune system) could be activated by zona pellucida-degradation products including oligosaccharide chains from very early stage embryos (Fujiwara et al. 2009 J. Reprod. Immunol. 81, 1–8). If this is true, we predict that mammalian mothers recognise the presence of an embryo immediately after fertilization in vivo. The purpose of the present study was to compare the expressions of immune tolerance genes in bovine endometrial-luminal lymphoid (ELL) cells collected from animals after AI or embryo transfer (ET). ELL cells were collected from recipient cows inseminated with frozen–thawed semen on Day 0 (=oestrus, n = 8) and from cows that received a transferred embryo on Day 7 (n = 8) of the oestrous cycle. On Days 9 and 11, ELL cells ipsilateral to the corpus luteum were flushed non-surgically from four cows of each group using Ringer's solution (500 mL). To eliminate large cell clusters of endometrium and the embryo (blastocyst), the flushing medium was passed through an embryo collection filter (EmCon filter, 75 μm stainless steel screen). A single viable blastocyst was collected from each recipient cow. The recovered flushing medium containing ELL cells was centrifuged. The ELL cells were suspended in PBS and separated by Lympholyte-H (Cedarlane, Ontario, Canada) gradient centrifugation. Using RT-real-time PCR, transcripts for four immune tolerance genes in ELL cells from AI or ET examined were transforming growth factor-β (TGF-β), macrophage-colony stimulating factor (M-CSF), interleukin-10 (IL-10), and forkhead box P3 (Foxp3). Data were normalized to that of an endogenous control (glyceraldehyde-3-phosphate dehydrogenase) and analysed using ANOVA followed by Scheffe′s test. Transcripts for TGF-β, M-CSF, IL-10, and Foxp3 were detected in all RT-samples derived from ELL cells on Days 9 and 11 of the oestrous cycle. Transcript levels of TGF-β, M-CSF and IL-10 in the AI group were the same as those of the ET group (P > 0.05), although the transcript level of Foxp3, a master regulator of the function of regulatory T-cells, in the AI group was significantly higher than that of the ET group on Days 9 and 11 (P < 0.05). Furthermore, the transcript level of Foxp3 in the ET group on Day 11 was significantly higher than that of the ET group on Day 9 (P < 0.05). These results indicate that the embryo-maternal recognition in AI occurs earlier than in ET, and suggest that cows recognise an embryo earlier than those generally believed.

Association of a polymorphism of BTN2A1 with myocardial infarction in East Asian populations

OBJECTIVE

We have performed a genome-wide association study (GWAS) to identify genetic variants that confer susceptibility to myocardial infarction (MI) in Japanese and Korean populations.

METHODS

A total of 17,447 Japanese or Korean individuals from four independent subject panels was examined. Japanese subject panels A, B, and C comprised 134 individuals with MI and 137 controls, 1431 individuals with MI and 3161 controls, and 643 individuals with MI and 1347 controls, respectively, whereas the Korean population comprised 1880 individuals with MI and 8714 controls. A GWAS for MI was performed in Japanese subject panel A with the use of the Affymetrix GeneChip Human Mapping 500K Array Set.

RESULTS

Seventy single nucleotide polymorphisms (SNPs) significantly (P<1.0×10(-7)) associated with MI by the GWAS were examined further in Japanese subject panel B, revealing two SNPs (rs6929846 of BTN2A1, rs2569512 of ILF3) to be significantly (P<0.0007) associated with MI. The rs6929846 SNP of BTN2A1, but not rs2569512 of ILF3, was also significantly associated with MI in Japanese subject panel C. However, the association of neither rs6929846 nor rs2569512 with MI was replicated in the Korean population.

CONCLUSION

BTN2A1 may be a susceptibility gene for MI in Japanese individuals.

Habitual physical activity and health in the elderly: the Nakanojo Study

This article provides a detailed overview of both factors influencing habitual physical activity, and relationships between such activity and health in the elderly. Current cross-sectional data from the Nakanojo Study, which we have been carrying out since 2000, indicate substantial associations between the overall health of participants, and both the year-averaged daily step count and the year-averaged daily duration of effort undertaken at an intensity >3 metabolic equivalents (MET). In men, the extent of health is associated more closely with the daily duration of activity >3 MET than with the daily step count, whereas in women the association is closer for the step count than for the duration of activity >3 MET. In both sexes, the threshold amount of physical activity associated with better health is greater for physical than for mental benefits: >8000 vs >4000 steps/day and/or >20 vs >5 min/day at >3 MET, respectively. In other words, physical health is better in those spending at least 20 min/day in moderate walking (at a pace of around 1.4 m/s [5 km/h]) and a further >60 min of light activity per day. In contrast, better mental health is associated with much smaller amounts of deliberate physical activity. Both the intensity and the total volume of physical activity are influenced by meteorological factors, particularly precipitation and mean ambient temperature. Activity decreases exponentially to about 4000 steps/day as precipitation increases. Excluding the influence of rainfall, the daily step count peaks at a mean outdoor temperature of around 17 degrees C; above and especially below such readings, physical activity decreases as a quadratic function of temperature. Seasonal changes in the microclimate should thus be considered when designing interventions intended to increase the habitual physical activity of older adults. Based on these findings, we are now developing preventive tactics that should contribute to health promotion, disease prevention and thus a reduction in medical expenses for elderly people.

A case of fulminant amebic colitis with multiple large intestinal perforations

Amebic colitis normally causes mucous and bloody diarrhea stool as predominant symptoms, thus leading to a course of chronic colitis. However, though rare, there exists a fulminating type that causes intestinal perforations due to wide necrosis of the large intestine. We encountered a case of fulminant amebic colitis that lead to death due to multiple large intestinal perforations. The patient was a 72-year-old female. The patient was admitted to our hospital with symptoms of fever, abdominal pain, and diarrhea. She continued to have a fever of over 38 degrees C and increased left abdominal pain. An abdominal computed tomography scan revealed free gas on the abdominal side of the kidney. Therefore, gastrointestinal perforations were diagnosed and surgery was performed. In surgery, many perforated parts were observed from the appendix to the descending colon, and subtotal colectomy was performed. However, sepsis and disseminated intravascular coagulation occurred, and the patient died on the eighth postoperative day.

Association of genetic variants with myocardial infarction in Japanese individuals with different lipid profiles

Dyslipidemia is an important risk factor for myocardial infarction (MI). We previously showed that gene polymorphisms associated with MI differed among individuals with different lipid profiles. We further examined whether genetic variants that confer susceptibility to MI might differ among individuals with low or high serum concentrations of triglycerides, high density lipoprotein (HDL)-cholesterol, or low density lipoprotein (LDL)-cholesterol. The study population comprised 5270 Japanese individuals, including 1188 subjects with MI and 4082 controls. The 150 polymorphisms examined in the present study were selected by genome-wide association studies of MI and ischemic stroke with the use of the Affymetrix GeneChip Human Mapping 500K Array Set. The initial Chi-square test revealed that the A->G polymorphism (rs12632110) of SEMA3F was significantly (false discovery rate <0.05) associated with MI among individuals with high serum HDL-cholesterol or among those with low serum LDL-cholesterol. Subsequent multivariable logistic regression analysis with adjustment for covariates revealed that rs12632110 was significantly (P<0.01) associated with MI in individuals with high serum HDL-cholesterol or with low serum LDL-cholesterol. The genetic variants that confer susceptibility to MI differ among individuals with different lipid profiles, and the genetic component for the development of MI is more apparent in individuals at low-risk (high HDL- and low LDL-cholesterol levels) compared to those at high-risk. Stratification of subjects according to lipid profiles may thus be important for personalized prevention of MI based on genetic information.

Association of genetic variants with hemorrhagic stroke in Japanese individuals

Although genetic epidemiological studies have implicated several genetic variants as risk factors for hemorrhagic stroke, the genetic determinants of this condition remain largely unknown. We examined an association of genetic variants with intracerebral or subarachnoid hemorrhage among Japanese individuals. The study population comprised 4,304 unrelated Japanese individuals, including 377 subjects with intracerebral hemorrhage, 205 subjects with subarachnoid hemorrhage, and 3,722 controls. The 150 polymorphisms examined in the present study were selected by genome-wide association studies of ischemic stroke and myocardial infarction with the use of the GeneChip Human Mapping 500K Array Set. The chi-square test, multivariable logistic regression analysis with adjustment for covariates, as well as a stepwise forward selection procedure revealed that the C->T polymorphism (rs1324694) of ERLIN1, the C->T polymorphism (rs12679196) of TRAPPC9, and the G->T polymorphism (rs16936752) of WNK2 were significantly (P<0.05) associated with the prevalence of intracerebral hemorrhage, and that the A->G polymorphism (rs3111754) of ITM2C and the A->G polymorphism (rs10986769) of MAPKAP1 were significantly associated with the prevalence of subarachnoid hemorrhage. Genotypes for ERLIN1, TRAPPC9, and WNK2 may prove informative for assessment of the genetic risk for intracerebral hemorrhage, and those for ITM2C and MAPKAP1 may be beneficial in assessment of the genetic risk for subarachnoid hemorrhage in Japanese individuals.

Genetic risk for myocardial infarction in Japanese individuals with or without chronic kidney disease

Although chronic kidney disease (CKD) is recognized as an important risk factor for myocardial infarction (MI), genetic factors underlying predisposition to MI in individuals with or without CKD remain largely unknown. The aim of the present study was to identify genetic variants that confer susceptibility to MI in individuals with or without CKD in order to allow prediction of genetic risk for such individuals separately. The study population comprised a total of 4344 individuals, including 1247 individuals with CKD (506 subjects with MI and 741 controls) and 3097 individuals without CKD (833 subjects with MI and 2264 controls). The 150 polymorphisms examined in this study were selected by genome-wide association studies of ischemic stroke and MI with the use of the GeneChip Human Mapping 500K Array Set (Affymetrix) and determined by a method that combines the polymerase chain reaction and sequence-specific oligonucleotide probes with suspension array technology. In individuals with CKD, no polymorphism was significantly related to MI. In individuals without CKD, an initial screen by the Chi-square test revealed that the Cyright curved arrow T polymorphism of CLEC16A (rs9925481) and the Aright curved arrow G polymorphism of LAMA3 (rs12373237) were significantly (false discovery rate for allele frequencies of <0.05) associated with MI. Subsequent multivariable logistic regression analysis with adjustment for covariates revealed that the Cright curved arrow T polymorphism of CLEC16A (dominant model; P=0.0003; odds ratio, 0.66) and the Aright curved arrow G polymorphism of LAMA3 (recessive model; P=0.0087; odds ratio, 0.75) were significantly (P<0.05) associated with MI. A stepwise forward selection procedure also revealed that these polymorphisms were significant and independent determinants of MI. CLEC16A and LAMA3 may be susceptibility loci for MI in Japanese individuals without CKD. Determination of genotypes for CLEC16A and LAMA3 may prove informative for assessment of the genetic risk for MI in such individuals.

Association of genetic variants with ischemic stroke in Japanese individuals with or without metabolic syndrome

Although metabolic syndrome has been recognized as a risk factor for ischemic stroke, genetic factors associated with ischemic stroke in individuals with metabolic syndrome remain unknown. We examined an association of genetic variants with ischemic stroke among individuals with or without metabolic syndrome. The study population comprised 4,387 unrelated Japanese individuals, including 1,884 individuals with metabolic syndrome (240 subjects with ischemic stroke and 1,644 controls) and 2,503 individuals without metabolic syndrome (280 subjects with ischemic stroke and 2,223 controls). The 150 polymorphisms examined in the present study were selected by genome-wide association studies of ischemic stroke and myocardial infarction with the use of the GeneChip Human Mapping 500K Array Set (Affymetrix). The initial chi-square test revealed that the Cright curved arrow T polymorphism (rs9925481) of CLEC16A and the Aright curved arrow G polymorphism (rs4923918) of SPTBN5 were significantly (P<0.005) associated with ischemic stroke among individuals with metabolic syndrome. No polymorphism was significantly associated with ischemic stroke among individuals without metabolic syndrome. Multivariable logistic regression analysis with adjustment for covariates and a stepwise forward selection procedure revealed that the Aright curved arrow G polymorphism (rs4923918) of SPTBN5 was significantly (P<0.005), and the Cright curved arrow T polymorphism (rs9925481) of CLEC16A was almost significantly, associated with ischemic stroke in individuals with metabolic syndrome. Genetic variants that confer susceptibility to ischemic stroke may differ among individuals with or without metabolic syndrome. Stratification of subjects according to the presence or absence of metabolic syndrome may thus be important for personalized prevention of ischemic stroke based on genetic information.

226 EFFECT OF AMMONIA IN BOVINE FOLLICULAR FLUID AND OOCYTE MORPHOLOGY DERIVED FROM ABATTOIR OVARIES

In cattle, high intake of crude protein elevates rumen ammonia and blood urea nitrogen and has been associated with decreased fertility. The aim of this study was to analyze the concentration of ammonia in bovine follicular fluid derived from abattoir ovaries and to examine the relation between ammonium concentration and morphology of oocytes from antral follicles. In the first experiment, follicular fluid was collected within 1 h of slaughter from 3919 small (2-5 mm in diameter), 366 medium (6-9 mm), and 159 large (10-20 mm) follicles from 203 ovaries. Ammonium concentration was analyzed in 6 batches pooled from follicular fluids of each size (derived from 15, 39, 7, 36, 81, and 25 ovaries, respectively). Ammonium concentration was measured by the microdiffusion method using an Ami Check Meter kit (Kyoto Daiichi Kagaku Co., Ltd., Japan). In the second experiment, follicular fluids were aspirated from small (2-5 mm) follicles of 38 cows to evaluate the relationship between ammonium concentration and oocyte morphology. Oocytes were classified into 4 morphological categories according to the surrounding cumulus cells (Konishi M et al. 1996 Theriogenology 45, 573-581): grade 1 (≥5 layers); grade 2 (3-4 layers); grade 3 (1-2 layers); and grade 4 (denuded, degenerated cumulus cell mass or ooplasm). The oocyte morphology for the low-ammonium group (<330 μmol, 239 oocytes from 19 cows) and high-ammonia group (≥330 μmol, 255 oocytes from 19 cows) was compared. Statistical significance was tested by chi-square test or t-test Ammonium con- centrations of small (281.8 ± 20.0 μM), medium (175.4 ± 15.8 μM), and large (96.3 ± 9.3 μM) follicles were significantly different (P < 0.0001). Ammonium concentrations in follicular fluid of the 38 cows ranged from 180.6 to 802.4 μM. In a comparison of oocyte morphology between the low- (263.8 ± 41.6 μM) and high-ammonium (423.0 ± 108.9 μM) groups, the number of grade 1, 2, 3, and 4 oocytes in the former (80, 68, 18, and 73, respectively) were not significantly different from the numbers in the latter (96, 61, 27, and 71, respectively; P = 0.30-0.99). These results indicate that, in follicles of different sizes derived from abattoir ovaries, the ammonium concentration was higher in small follicles than in the other sizes of follicles. However, there was no evidence that in vivo exposure of bovine oocytes to ammonium badly influenced oocyte morphology. Further studies are needed to examine the relationship between ammonium concentration and the developmental potential of oocytes.

277 EFFECTS OF ERYTHROCYTE AND ERYTHROCYTE HEMOLYSATE ON BOVINE PREIMPLANTATION EMBRYO DEVELOPMENT IN VITRO UNDER REACTIVE OXYGEN SPECIES CONDITION

Reactive oxygen species (ROS) damage preimplantation embryos by increasing DNA fragmentation, leading to early embryonic death. Erythrocytes have been shown to protect other cells and tissues against ROS. In mice, erythrocytes were recently found to improve the early development of embryos by their antioxidant effect. The purpose of the present study was to examine the effect of erythrocytes on the in vitro development of bovine IVF embryos in medium supplemented with ROS. COCs were aspirated from ovaries collected from a local slaughterhouse and were cultured for 22 h in TCM-199 containing 5% fetal bovine serum. IVF was performed using an IVF100 (Research Institute for the Functional Peptides, Yamagata, Japan) according to the manufacturer’s instructions. In experiment 1, IVF embryos were cultured in CR1aa medium supplemented with an oxidizing agent, 0.5 mM hypoxanthine and 0.01 U mL-1 xanthine oxidase (HX/XOD), in the presence and absence of erythrocytes (5 × 104, 5× 105, 5×106, and 5 × 107 erythrocytes mL-1). In experiments 2 and 3, the development of embryos under the condition without ROS was assessed in the presence and absence of erythrocytes (5 × 106 erythrocytes mL-1) or erythrocyte hemolysate (hemoglobin concentration of 1.9 g L-1), respectively. At 7 days after in vitro culture, the development to the blastocyst stage of IVF embryos was examined using a stereomicroscope. Data were analyzed using Fisher’s PLSD test and Student’s t-test In experiment 1, the presence of HX/XOD significantly inhibited embryo development to the blastocyst stage in vitro (P < 0.05). The addition of erythrocytes to medium supplemented with HX/XOD markedly improved preimplantation development (Table 1). In experiments 2 and 3, supplementation of erythrocytes or erythrocyte hemolysate promoted the development of embryos to the blastocyst stage (experiment 2: erythrocyte 42.4 ± 3.1%, control 28.5 ± 5.7%, P < 0.1; experiment 3: erythrocyte hemolysate 39.1 ± 3.3%, control 30.2 ± 1.0%, P < 0.1). In conclusion, we suggest that the addition of erythrocytes to culture medium can counteract the negative effects of ROS on embryo development and blastocyst formation. Table 1.Effect of HX/XOD and erythrocyte supplementation on embryo development to blastocyst stage

Association of genetic variants with myocardial infarction in individuals with or without hypertension or diabetes mellitus

Hypertension and diabetes mellitus are important risk factors for myocardial infarction (MI). The purpose of the present study was to identify genetic variants that confer susceptibility to MI in individuals with or without hypertension or diabetes mellitus, thereby contributing to the personalized prevention of MI in such individuals. The study population comprised 5,835 unrelated Japanese individuals, including 1,339 subjects with MI and 4,496 controls. The 150 polymorphisms were selected by genome-wide association studies of MI and ischemic stroke with the use of the GeneChip Human Mapping 500K Array Set. The genotypes for these polymorphisms were determined by a method that combines the polymerase chain reaction and sequence-specific oligonucleotide probes with suspension array technology. The chi-square test, multivariable logistic regression analysis with adjustment for covariates, as well as a stepwise forward selection procedure revealed that three different polymorphisms were significantly (P<0.005) associated with the prevalence of MI in individuals with or without hypertension or diabetes mellitus: the C --> T polymorphism of CLEC16A (rs9925481) in individuals without hypertension, the A --> G polymorphism of SEMA3F (rs12632110) in individuals without diabetes mellitus and the A --> G polymorphism of ALOX5 (rs7913948) in individuals without hypertension or diabetes mellitus. No polymorphism was significantly associated with MI in individuals with hypertension, in those with diabetes mellitus, or in those with both conditions. Stratification of subjects based on hypertension or diabetes mellitus may thus be important in order to achieve personalized prevention of MI with the use of genetic information.

Association of gene polymorphisms with chronic kidney disease in Japanese individuals

Chronic kidney disease (CKD) is recognized as a risk factor not only for end-stage renal disease but also for cardiovascular disease. Early detection and treatment of CKD is a likely key factor for prevention of its complications. Although genetic linkage analyses and association studies have implicated several loci and candidate genes in predisposition to CKD, the genes that underlie genetic susceptibility to this condition have remained largely unknown. The purpose of the present study was to identify genetic variants that confer susceptibility to CKD in Japanese individuals. The study population comprised 4,829 Japanese individuals (2,697 men, 2,132 women), including 757 subjects with CKD [464 men, 293 women; estimated glomerular filtration rate (eGFR) <50 ml min 1.73 m(-2)] and 4,072 controls (2,233 men, 1,839 women; eGFR >or=60 ml min 1.73 m(-2)). The genotypes for 40 polymorphisms of 39 candidate genes were determined. The chi-square test, multivariable logistic regression analysis with adjustment for covariates, as well as a stepwise forward selection procedure revealed that six polymorphisms of F10, PITRM1, PCSK2, JPH3, MYO7B, and AKAP12 were related (P<0.05) to the prevalence of CKD. Among these polymorphisms, the Cright curved arrow T polymorphism of F10 (rs5962) was most significantly associated with this condition. Determination of genotypes for the Cright curved arrow T polymorphism of F10 may prove informative for assessment of genetic risk for CKD in Japanese individuals.

Association of genetic variants with chronic kidney disease in individuals with different lipid profiles

The purpose of the present study was to identify genetic variants that confer susceptibility to chronic kidney disease (CKD) in individuals with low or high serum concentrations of triglycerides (TG), high-density lipoprotein (HDL)-cholesterol, or low-density lipoprotein (LDL)-cholesterol, thereby contributing to the personalized prevention of CKD in such individuals. The study population comprised 5944 Japanese individuals, including 1706 subjects with CKD [estimated glomerular filtration rate (eGFR)<60 ml/min/1.73 m2] and 4238 controls (eGFR>or=60 ml/min/1.73 m2). The genotypes for 296 polymorphisms of 202 candidate genes were determined. The Chi-square test, multivariable logistic regression analysis with adjustment for covariates, and a stepwise forward selection procedure revealed that seven different polymorphisms were significantly (P<0.005) associated with the prevalence of CKD in individuals with low or high serum concentrations of TG or HDL- or LDL-cholesterol: the Aright curved arrow G (Glu23Lys) polymorphism of KCNJ11 and the 125592Cright curved arrow A (Thr431Asn) polymorphism of ROCK2 in individuals with low serum TG; the 734Cright curved arrow T (Thr254Ile) polymorphism of ACAT2 and the Cright curved arrow G (Gln27Glu) polymorphism of ADRB2 in individuals with high serum TG; the -1607/1Gright curved arrow 2G polymorphism of MMP1 in individuals with low serum HDL-cholesterol; the Gright curved arrow A (Val158Met) polymorphism of COMT in individuals with low serum LDL-cholesterol; the 584Gright curved arrow A (Gln192Arg) polymorphism of PON1 in individuals with high serum LDL-cholesterol. No polymorphism was associated with CKD in individuals with high serum HDL-cholesterol. These results suggest that polymorphisms associated with CKD may differ among individuals with different lipid profiles. Stratification of subjects according to lipid profiles may thus be important for personalized prevention of CKD based on genetic information.

Habitual physical activity and physical fitness in older Japanese adults: the Nakanojo Study

BACKGROUND

Optimal patterns of habitual physical activity to ensure healthy aging remain unclear because of measurement limitations; most investigators have used either subjective questionnaires, or accelerometer or pedometer measurements limited to a single week, despite evidence of both the limited reliability/validity of questionnaires and seasonal changes in activity patterns.

OBJECTIVE

This study explored possible associations between indicators of physical fitness (walking ability, upper- and lower-extremity isometric strength, and static and dynamic balance) and yearlong pedometer/accelerometer assessments of the quantity and quality of habitual physical activity in ostensibly healthy older adults.

METHODS

Subjects were 76 male and 94 female Japanese aged 65-84 years. Each participant wore a pedometer/accelerometer for 1 year; measurements included the average number of steps taken each day and the duration of activity at an intensity of >3 metabolic equivalents (METs). Compliance was good, the instrument being removed for intervals of >3 h on <5% of days; data for such intervals were excluded from analysis. At the year's end, traditional laboratory techniques assessed preferred and maximal walking speeds, peak handgrip force, peak knee extension torque, total body sway, and maximal functional reach.

RESULTS

After controlling data for age and/or sex, lower-extremity function (walking speeds and knee extension torque) showed significant positive relationships with the daily step count and daily duration of activity at >3 METs, especially in individuals > or = 75 years of age. On the other hand, handgrip force and body sway were unrelated to pedometer/accelerometer measurements. Linear and exponential regressions showed positive associations between walking speeds and pedometer/accelerometer scores up to the observed maxima of 13,700 steps/day and 62 min/day at >3 METs. However, when data were categorized into quartiles, walking speeds were not significantly greater in persons exceeding 7,000-8,000 steps/day and/or 15-20 min/day at >3 METs. With a few exceptions, subjects meeting these levels of habitual activity had walking speeds above the threshold predicting the development of functional dependence.

CONCLUSION

The present data suggest that fitness is well maintained in elderly people who take >7,000-8,000 steps/day and/or spend >15-20 min/day at >3 METs. Nevertheless, the direction of this association merits exploration by longitudinal prospective studies and/or randomized controlled trials.

Association of genetic variants with chronic kidney disease in Japanese individuals with type 2 diabetes mellitus

Although diabetes mellitus has been recognized as a risk factor for chronic kidney disease (CKD), genetic factors for predisposition to CKD in individuals with diabetes mellitus remain elucidated. The purpose of the present study was to identify genetic variants that confer susceptibility to CKD among individuals with type 2 diabetes mellitus. The study population comprised 1742 Japanese individuals, including 636 subjects with CKD [estimated glomerular filtration rate (eGFR)<60 ml/min/1.73 m2] and 1106 controls (eGFR>or=60 ml/min/1.73 m2). The genotypes for 24 polymorphisms of 22 candidate genes were determined. An initial screen of allele frequencies by the Chi-square test revealed that four polymorphisms were significantly (false discovery rate<0.05) associated with the prevalence of CKD in individuals with type 2 diabetes mellitus. Subsequent multivariable logistic regression analysis with adjustment for covariates as well as a stepwise forward selection procedure revealed that the 8733T-->C polymorphism of ALOX5AP (rs3803278), the C-->T (Ser532Leu) polymorphism of IRAK1 (rs1059703), and the 2445G-->A (Ala54Thr) polymorphism of FABP2 (rs1799883) were significantly (P<0.05) associated with the prevalence of CKD. Our results suggest that ALOX5AP, IRAK1, and FABP2 are susceptibility loci for CKD among Japanese individuals with type 2 diabetes mellitus.

Association of gene polymorphisms with chronic kidney disease in high- or low-risk subjects defined by conventional risk factors

The purpose of the present study was to identify genetic variants which confer susceptibility to chronic kidney disease (CKD) in high- or low-risk subjects defined by conventional risk factors separately. The study population comprised 2828 Japanese individuals, including 434 subjects with CKD [estimated glomerular filtration rate (eGFR) <60 ml/min/1.73 m(2)] and 2394 controls (eGFR > or =60 ml/min/ 1.73 m(2)). The 1012 high-risk subjects had both hypertension and diabetes mellitus, and the 1816 low-risk subjects had none of these conditions. The genotypes for 296 polymorphisms of 202 candidate genes were determined. The Chi-square test, multivariable logistic regression analysis with adjustment for covariates, as well as a stepwise forward selection procedure revealed that ten different polymorphisms were associated (P<0.05) with the prevalence of CKD in high- or low-risk subjects: the -519Aright curved arrow G polymorphism of MMP1, the 1061Aright curved arrow G (Ile405Val) polymorphism of CETP, the Aright curved arrow G (Lys45Glu) polymorphism of MMP3, the -219Gright curved arrow T polymorphism of APOE, the Aright curved arrow G (Ile1205Val) polymorphism of COL3A1, the -863Cright curved arrow A polymorphism of TNF, and the 1454Cright curved arrow G (Leu125Val) polymorphism of PECAM1 in high-risk subjects; and the 1167Cright curved arrow T (Asn389Asn) polymorphism of TGFBR2, the 2386Aright curved arrow G (Ile796Val) polymorphism of SCAP, and the TAAAright curved arrow del polymorphism of PDE4D in low-risk subjects. Among these polymorphisms, the -519Aright curved arrow G polymorphism of MMP1 and the 1167Cright curved arrow T (Asn389Asn) polymorphism of TGFBR2 were most significantly associated with CKD in high- or low-risk individuals, respectively. These results suggest that polymorphisms associated with CKD may differ among high- or low-risk subjects. Stratification of subjects according to conventional risk factors may thus be important for personalized prevention of CKD based on genetic information.

Steps per day: the road to senior health?

In older adults, as in younger individuals, habitual moderate-intensity physical activity is associated with a reduced risk of various chronic health conditions, including certain types of cardiovascular and musculoskeletal disease and certain forms of cancer. However, the pattern of physical activity associated with such benefits remains unclear. One problem is that most investigators have examined patterns of physical activity using either subjective questionnaires or accelerometer or pedometer measurements limited to a single week, despite clear evidence of both the unreliability/invalidity of questionnaires and seasonal changes in activity patterns. Since 2000, we have thus conducted an interdisciplinary study examining the habitual physical activity and health of elderly people living in a medium-sized Japanese town (the Nakanojo Study). In about one-tenth of some 5000 available subjects aged > or =65 years, physical activity has already been assessed continuously for 24 h/day for >8 years using a specially adapted pedometer/accelerometer. This device has a storage capacity of 36 days and can distinguish >10 intensities of physical activity (expressed in metabolic equivalents [METs]). Data have to date been summarized as daily step counts and daily durations of activity of <3 and >3 METs, averaged over a 1-year period. This article provides a detailed overview of both factors influencing habitual physical activity and relationships between such activity and health in an elderly population. To date, analyses have been cross-sectional in type. Substantial associations have been noted between the overall health of participants and both the daily duration of effort undertaken at an intensity of >3 METs and the daily step count. In men, the extent of health is associated more closely with the daily duration of activity of >3 METs than with the daily step count, whereas in women, the association is closer for the step count than for the duration of activity >3 METs. In both sexes, the threshold amount of physical activity associated with better health is greater for physical than for mental benefits: >8000 versus >4000 steps/day and/or >20 versus >5 min/day at an intensity >3 METs, respectively. In other words, better physical health is seen in those spending at least 20 min/day in moderate walking (at a pace of around 1.4 m/s [5 km/h]) and a further >60 min of light activity per day. In contrast, better mental health is associated with much smaller amounts of deliberate physical activity. The daily step count and the daily durations of activity of <3 and >3 METs are all influenced by meteorological factors, particularly precipitation and mean ambient temperature. Activity decreases exponentially to about 4000 steps/day as precipitation increases. Excluding the influence of rainfall, the daily step count peaks at a mean outdoor temperature of around 17 degrees C; above and especially below such readings, physical activity decreases as a quadratic function of temperature. Seasonal changes in microclimate should thus be considered when designing interventions intended to increase the habitual physical activity of elderly people. The observed associations between physical activity and health outcomes point to a need for longitudinal analyses; these should examine potential causal interpretations of the current findings and elucidate possible additional mediating variables.

Seasonal variations in physical activity and implications for human health

This review explores the implications of seasonal changes in physical activity for fitness and human health. Photosensitivity and nutrient shortages mediate animal hibernation via the hypothalamus and changes in leptin and ghrelin concentrations. Opportunities for hunting and crop cultivation determine seasonal activity in under-developed human societies, but in developed societies temperature and rainfall are dominant influences, usually over-riding innate rhythms. Both questionnaire data and objective measurements show that many groups from children to the elderly increase their physical activity from winter to spring or summer. Measurements of maximal oxygen intake and muscle strength commonly show parallel seasonal changes. However, potential effects upon body mass and body fat may be counteracted by changes of food intake; subsistence agriculturists sometimes maintain or increase physical activity at the expense of a decrease in body mass. In developed societies, body fat commonly increases during the winter, with parallel changes in blood lipids, blood pressure and blood coagulability; moreover, these changes are not always fully reversed the following summer. Most developed societies show increased all-cause and cardiac mortalities in the winter. Health consequences of seasonal variations in physical activity including an increased vulnerability to cardiac catastrophe and a year-by-year increase in total body fat seem most likely if the average level of physical activity for the year is low. Public health recommendations should underline the importance of maintaining physical activity during adverse environmental conditions by adapting clothing, modifying behaviour and exploiting any available air-conditioned indoor facilities.