46 HYPOTHERMIC STORAGE FOR 10 DAYS OF BOVINE EMBRYOS USING TYPE III ANTIFREEZE PROTEIN

Recently, we developed a medium that enabled bovine embryos to be held for up to 7 days at 4°C (Tsuchiya et al. 2014 IETS meeting). To be of practical value, mammalian embryo preservation at hypothermic temperatures must be able to maintain viability for periods longer than 7 days. Antifreeze proteins (AFP) were discovered in various organisms (such as fish, insects, plants, and bacteria) living in cold regions. They show a unique ability to protect cold-sensitive cells from hypothermic damage. Here, we found that a biomolecule known as type III AFP solubilised into an optimized solvent can keep alive bovine embryos for a maximum of 10 days at hypothermic temperatures. First, human hepatoma (HepG2) and rat insulinoma (RIN-5F) cells were stored at 4°C in Euro-Collins solution (Kobayashi Seiyaku, Osaka, Japan) supplemented with or without 10 mg mL–1 of type III AFP for 24 h. The viability rate of the cells was assessed by trypan blue (Dojindo, Kumamoto, Japan) dissolved in PBS. Second, high-quality blastocysts produced in vivo were stored at 4°C in a plastic ministraw in 25 mM HEPES medium 199 plus 20% fetal bovine serum (FBS) supplemented with or without 10 mg mL–1 of type III AFP for 10 days. Following hypothermic preservation, the chilled embryos were squeezed out of the straw into PBS and washed 3 times in the same medium. Subsequently, the embryos were cultured in CR1aa medium supplemented with 5% FBS for 48 h at 38.5°C under 5% CO2 in air with high humidity. The viability and hatching rate of the embryos were assessed at the end of the culture period. Finally, 4 embryos stored for 10 days with type III AFP were reloaded into plastic straws with the washing medium and transferred into recipient heifers (1 embryo per recipient). Pregnancy was determined by real-time B-mode ultrasonography (Convex scanner HS-1500, Honda Electronics Co. Ltd., Toyohashi, Japan) on Day 60 of gestation. Data were analysed using chi-squared and Student's t-tests. In the absence of type III AFP, the cell viability values of HepG2 and RIN-5F after hypothermic storage for 24 h were only 5 and 22%, respectively. However, in the presence of type III AFP, the cell viability values were dramatically increased (HepG2: 71%; RIN-5F: 59%) than those measured without type III AFP. To examine the effect of type III AFP for hypothermic preservation of bovine embryos, we used 80 high-quality embryos produced in vivo and assigned them randomly to 2 experimental groups. The viability and hatching rates of the chilled embryos stored with type III AFP for 10 days were significantly higher (58 and 30%, respectively) than those of without type III AFP (28 and 0%, respectively). The pregnancy rate of the chilled embryos stored with type III AFP was 50%: 2 pregnancies continue until now. In conclusion, prolongation of short-term preservation period with AFP-containing fluid will realise LN2-free storage of bovine embryos for a 10-day period. This work was supported by the Program for Promotion of Basic and Applied Research for Innovations in Bio-Oriented Industry.

51 ARTIFICIAL DORMANCY OF BOVINE EMBRYOS FOR A MAXIMUM OF 7 DAYS USING A SIMPLE MEDIUM

The worldwide pregnancy rate using cryopreserved mammalian embryos has not improved over the past 2 decades, probably because the freeze-thawing processes cause significant damage. Therefore, it is now relevant to examine the feasibility of short-term non-freezing preservation, and whether this could be applied to embryos that have high vitality and are to be transferred into recipients within several days. We introduce here an artificial dormancy fluid that can extend the hypothermic storage period of bovine embryos for a maximum of 7 days. First, to examine the effect of different basal media and the optimal concentration of fetal bovine serum (FBS) for hypothermic preservation, bovine blastocysts produced in vitro were stored at 4°C in a plastic ministraw in 1 of the following 3 media: PBS, medium 199, or Leibovitz L15 with various amount of FBS (0, 5, 20, 50, or 100%) for 3 days. Second, to examine the effect of Good's buffers, bovine embryos produced in vivo (morula to blastocyst stages) were stored at 4°C in a plastic ministraw in medium 199 plus 50% FBS supplemented with various Good's buffers [HEPES, TES, piperazine-N,N′-bis(2-ethanesulfonic acid) (PIPES), MOPS, and 4-(2-hydroxyethyl)piperazine-1-propanesulfonic acid (EPPS)] for 7 days. Following hypothermic preservation, the chilled embryos were squeezed out of the straw into PBS and washed 3 times in the same medium. Subsequently, the embryos were cultured in CR1aa medium supplemented with 5% FBS for 48 h at 38.5°C under 5% CO2 in air with high humidity. The viability rate of the embryos was assessed at the end of the culture period. Finally, to observe the pregnancy rate of chilled embryos, 32 embryos produced in vivo were stored at 4°C for 7 days in medium 199 plus 50% FBS supplemented with HEPES. Following hypothermic preservation, the chilled embryos were transferred into recipient heifers (1 embryo per recipient). Pregnancy was determined by real-time B-mode ultrasonography (Convex scanner HS-1500, Honda electronics Co. Ltd, Toyohashi, Japan) on Day 60 of gestation. Data were analysed using the chi-squared test. The viability rate of the embryos after hypothermic storage for 3 days was significantly increased for medium 199 plus 50% FBS [27/30 (90%)] compared with PBS [18/30 (60%)] or Leibovitz L15 [15/30 (50%)] plus 50% FBS (P < 0.05). Chilled embryos stored for 7 days in medium 199 plus 50% FBS supplemented with HEPES had much higher survival than embryos stored in the same medium with other Good's buffers. The pregnancy rate of the chilled embryos stored for 7 days was extremely high [24/32 (75%)] and normal live calves were delivered at term. In conclusion, maintaining artificial dormancy of bovine embryos for 7 days using a simple medium appears to be feasible. This is the first documented success of storing chilled mammalian embryos in a viable state for 7 days. To be of practical value, bovine embryo preservation at hypothermic temperatures must be able to maintain viability for periods longer than 7 days. This work was supported by the Program for Promotion of Basic and Applied Research for Innovations in Bio-Oriented Industry.

Novel electric power-driven hydrodynamic injection system for gene delivery: safety and efficacy of human factor IX delivery in rats

The development of a safe and reproducible gene delivery system is an essential step toward the clinical application of the hydrodynamic gene delivery (HGD) method. For this purpose, we have developed a novel electric power-driven injection system called the HydroJector-EM, which can replicate various time-pressure curves preloaded into the computer program before injection. The assessment of the reproducibility and safety of gene delivery system in vitro and in vivo demonstrated the precise replication of intravascular time-pressure curves and the reproducibility of gene delivery efficiency. The highest level of luciferase expression (272 pg luciferase per mg of proteins) was achieved safely using the time-pressure curve, which reaches 30 mm Hg in 10 s among various curves tested. Using this curve, the sustained expression of a therapeutic level of human factor IX protein (>500 ng ml(-1)) was maintained for 2 months after the HGD of the pBS-HCRHP-FIXIA plasmid. Other than a transient increase in liver enzymes that recovered in a few days, no adverse events were seen in rats. These results confirm the effectiveness of the HydroJector-EM for reproducible gene delivery and demonstrate that long-term therapeutic gene expression can be achieved by automatic computer-controlled hydrodynamic injection that can be performed by anyone.

Identification of chromosome 3q28 and ALPK1 as susceptibility loci for chronic kidney disease in Japanese individuals by a genome-wide association study

BACKGROUND

Although genome-wide association studies (GWASs) have implicated several genes in the predisposition to chronic kidney disease (CKD) in Caucasian or African American populations, the genes that confer susceptibility to CKD in Asian populations remain to be identified definitively. We performed a GWAS to identify genetic variants that confer susceptibility to CKD in Japanese individuals.

METHODS

3851 Japanese individuals from three independent subject panels were examined. Subject panels A, B, and C comprised 252, 910, and 190 individuals with CKD and 249, 838, and 1412 controls, respectively. A GWAS for CKD was performed in subject panel A.

RESULTS

Five single nucleotide polymorphisms (SNPs) at chromosome 3q28, ALPK1, FAM78B, and UMODL1 were significantly (false discovery rate<0.05) associated with CKD by the GWAS. The relation of these five SNPs and of an additional 22 SNPs at these loci to CKD was examined in subject panel B, revealing that rs9846911 at 3q28 was significantly associated with CKD in all individuals and that rs2074381 and rs2074380 in ALPK1 were associated with CKD in individuals with diabetes mellitus. These three SNPs were further examined in subject panel C, revealing that rs2074381 and rs2074380 were significantly associated with CKD. For subject panels B and C combined, rs9846911 was significantly associated with CKD in all individuals and rs2074381 and rs2074380 were associated with CKD in diabetic individuals.

CONCLUSIONS

Chromosome 3q28 may be a susceptibility locus for CKD in Japanese individuals, and ALPK1 may be a susceptibility gene for CKD in such individuals with diabetes mellitus.

156 THE USE OF THE DG29™ ENZYME-LINKED IMMUNOSORBENT ASSAY KIT TO PREDICT PREGNANCY PRIOR TO EMBRYO TRANSFER IN LACTATING HOLSTEIN COWS

Evaluation of postpartum fertility in cows is important for the efficient management of reproduction. DG29™ enzyme-linked immunosorbent assay (ELISA) kit (Conception, Animal Reproduction Technologies, Canada) measures the level of pregnancy–related glycoproteins in blood that are linked to pregnancy in the bovine species. The proteins are known to persist in the postpartum period. Here, we investigated whether the postpartum fertility in Holstein dairy cows can be evaluated through the use of the DG29 kit. We confirmed that genital organs of lactating Holstein cows (n = 119, from Days 56 to 688 postpartum) were normal by a 5.0/7.5-MHz linear array transducer (Tringa, Pie Medical Equipment B.V., Maastricht, The Netherlands), then a progesterone releasing intravaginal device (PRID; CEVA Sante Animale, Libourne, France) was inserted (Day 0) and maintained for 9 days. On Day 7, PGF2α was administered (2 mL Dalmazine, Kyoritsu Seiyaku, Tokyo, Japan). Blood samples were collected from the tail vein or artery into vacuum tubes at the time of PRID insertion. Serum was separated and stored at –30°C until the ELISA was performed. Oestrus (Day 0) was detected by visual observation. Fresh embryos recovered from Japanese Black cows were transferred to 119 recipient cows in various parities (primiparous = 70, biparous = 27, and multiparous = 22) on Days 6 to 8 of oestrous cycle. Pregnancy was diagnosed between Days 40 to 60 by transrectal ultrasonography. The statistical significance of any differences between various parities was assessed by chi-squared and Student’s t-tests. The pregnancy rate was higher for primiparous cows than for biparous and multiparous cows (64.3, 55.6, and 54.5%, respectively), while concentrations of the pregnancy-related glycoproteins in primiparous cows (135.0 ± 29.8 pg mL–1) were significantly lower than those of biparous (389.4 ± 175.9 pg mL–1) and multiparous cows (399.2 ± 203.1 pg mL–1, mean ± SEM; P < 0.05). In primiparous and multiparous cows, the concentrations of pregnancy-related glycoproteins were significantly lower in pregnant cows compared with nonpregnant cows (primiparous: 81.1 ± 29.9 v. 232.6 ± 59.8 pg mL–1; P < 0.05; multiparous: 20.8 ± 16.2 v. 853.4 ± 411.5 pg mL–1; P < 0.05). However, there was no significant difference between pregnant and nonpregnant biparous cows. In conclusion, the DG29 kit may be useful for the prediction of postpartum fertility in lactating Holstein cows. Further studies are needed to test the validity of this observation by using a greater number of various parties’ cows.

Association of polymorphisms of THBS2 and HSPA8 with hypertension in Japanese individuals with chronic kidney disease

The purpose of the present study was to identify gene polymorphisms that confer susceptibility to hypertension in individuals with chronic kidney disease (CKD), thereby contributing to the prediction of genetic risk for this condition. The study population comprised 1824 Japanese individuals with CKD [estimated glomerular filtration rate (eGFR) <60 ml min-1 1.73 m-2], including 1257 subjects with hypertension and 567 controls. The genotypes for 50 polymorphisms of 46 candidate genes were determined using a method that combines the polymerase chain reaction and sequence-specific oligonucleotide probes with suspension array technology. An initial screen of allele frequencies by the χ2 test revealed that two polymorphisms were significantly (false discovery rate <0.05) associated with the prevalence of hypertension in individuals with CKD. Subsequent multivariable logistic regression analysis with adjustment for age, gender and the prevalence of diabetes mellitus revealed that these two polymorphisms, 3949T↷G (3'-UTR) of the thrombospondin 2 gene (THBS2; odds ratio in recessive model, 8.31) and -110A↷C of the heat shock 70-kDa protein 8 gene (HSPA8; odds ratio in recessive model, 0.72) were significantly (P<0.05) associated with the prevalence of hypertension. The variant G allele of THBS2 was a risk factor for hypertension, whereas the variant C allele of HSPA8 was protective against this condition. A stepwise forward selection procedure also demonstrated that the THBS2 and HSPA8 genotypes were significant (P<0.05) and independent determinants of hypertension. Determination of genotypes for these polymorphisms may prove informative for the prediction of genetic risk for hypertension in Japanese individuals with CKD. Validation of these findings will require additional studies with independent subject panels.

Molecular discrimination between alpha-fetoprotein from patients with hepatocellular-carcinoma and nonneoplastic liver-diseases by their carbohydrate structures (review)

Serum alpha-fetoprotein (AFP) is a good marker of HCC. However, this protein also increases moderately in non-neoplastic liver diseases. The serum concentration of AFP in HCC at the time of initial diagnosis has become lower thanks to the advancement of imaging modalities. These clinical circumstances have lead to the need of molecular discrimination of AFP between HCC and benign liver diseases. This has been attained by taking advantage of the reactivity of AFP with various lectins. The relative amount of the Lens culinaris agglutinin (LCA)-reactive species of AFP is significantly greater in HCC than in benign liver diseases. Molecular basis of this variation is the fucosylation of sugar chain at innermost N-acetyl-glucosamine. On the other hand, the concanavalin A (Con A)-nonreactive species of AFP increases in AFP-producing gastrointestinal carcinoma as compared with HCC and benign liver diseases. Molecular basis of Con A-nonreactive variants is the N-acetylglucosaminylation of the mannose residue at the trimannosyl core, although the position to be modified can be different. Therefore, the terms 'fucosylation and glucosaminylation indices' have been introduced to express the percentages of LCA-reactive and Con A-nonreactive species of AFP, respectively. The reactivity of AFP to erythroagglutinating phytohemagglutinin of Phaseolus vulgaris (E-PHA) also provides useful information for discrimination between HCC and benign liver diseases. These indices together with the measurement of E-PHA molecular variants are useful to detect HCC even if the disease is at an early stage. Furthermore, they seem to serve the prediction of HCC in the follow-up course of chronic liver diseases. Thus, not only qualitative but also quantitative measurements of lectin-based molecular variants of AFP provide us valuable information for the differential diagnosis of various liver diseases.

Magnetic compression anastomosis for bile duct stenosis after donor left hepatectomy: a case report

Magnetic compression anastomosis (MCA) provides a minimally invasive treatment creating a nonsurgical, sutureless enteric anastomosis in conjunction with an interventional radiologic technique by using 2 high-power magnets. Recently, the MCA technique has been applied to bile duct strictures after living donor liver transplantation or major hepatectomy. Herein we described use of MCA for bile duct stenosis 5 months after donor left hepatectomy in a 24-year-old man who presented with a stricture at the porta hepatis and intrahepatic bile duct dilatation. Unsuccessful transpapillary biliary drainage and balloon dilatation through a percutaneous transhepatic biliary drainage (PTBD) route led to the MCA. A 4-mm-diameter cylindrical samarium-cobalt (Sm-Co) daughter magnet with a long nylon wire was placed at the superior site of the obstruction through the PTBD route. A 5-mm-diameter Sm-Co parent magnet with an attached nylon handle was endoscopically inserted into the common bile duct and placed at the inferior site of obstruction. The 2 magnets were attracted, sandwiching the stricture and establishing a reanastomosis. In conclusion, the MCA technique was a unique procedure for choledochocholedochostomy in a patient with bile duct stenosis after donor hepatectomy.

Synergistic effects of genetic variants of APOA5 and BTN2A1 on dyslipidemia or metabolic syndrome

We previously showed that the -1131T→C polymorphism (rs662799) of the apolipoprotein A-V gene (APOA5) and the C→T polymorphism (rs6929846) of the butyrophilin, subfamily 2, member A1 gene (BTN2A1) were significantly associated with an increased serum concentration of triglycerides, a decreased serum concentration of high density lipoprotein (HDL)-cholesterol, and the prevalence of metabolic syndrome (MetS) in Japanese individuals. The purpose of the present study was to examine whether these polymorphisms synergistically affect the prevalence of dyslipidemia and MetS in East Asian populations. The study populations comprised 7471 Japanese and 3529 Korean individuals in the dyslipidemia study, and 3474 Japanese and 1671 Korean individuals in the MetS study. Multivariable logistic regression analysis of combined genotypes with adjustment for age, gender and diabetes mellitus revealed that rs662799 and rs6929846 significantly and synergistically affected dyslipidemia. Japanese or Korean individuals with the C allele of APOA5 and the T allele of BTN2A1 had a 2.05- or 1.92-fold increased risk for hypertriglyceridemia and a 1.82- or 1.56-fold increased risk for hypo-HDL-cholesterolemia, respectively, compared to those with the TT genotype of APOA5 and the CC genotype of BTN2A1. Similar analysis with adjustment for age and gender revealed that Japanese individuals, but not Korean individuals, with the C allele of APOA5 and the T allele of BTN2A1 had a 2.87-fold increased risk for MetS compared to those with the TT genotype of APOA5 and the CC genotype of BTN2A1. Genetic variants of APOA5 and BTN2A1 may synergistically affect the prevalence of dyslipidemia in East Asian populations and of MetS in Japanese individuals.

Association of a genetic variant of BTN2A1 with chronic kidney disease in Japanese individuals

AIM

Although recent genetic studies suggested that several genetic variants increase the risk for chronic kidney disease (CKD), the genes that underlie genetic susceptibility to this condition remain to be identified definitively. We showed that the C→T polymorphism (rs6929846) of BTN2A1 and A→G polymorphism (rs2569512) of ILF3 were significantly associated with myocardial infarction in Japanese individuals by a genome-wide association study. The purpose of the present study was to examine a possible association of these polymorphisms (rs6929846, rs2569512) with CKD in Japanese individuals.

METHODS

A total of 7542 Japanese individuals from two independent populations were examined: Subject panel A comprised 971 individuals with CKD (estimated glomerular filtration rate (eGFR) <60 mL/min 1.73 m(-2)) ) and 2269 controls (eGFR ≥60 mL/min 1.73 m(-2) ); and subject panel B comprised 1318 individuals with CKD and 2984 controls.

RESULTS

The χ(2) test revealed that rs6929846 of BTN2A1, but not rs2569512 of ILF3, was significantly related to the prevalence of CKD both in subject panels A (P = 0.0383) and B (P = 0.0477). Multivariable logistic regression analysis with adjustment for covariates revealed that the C→T polymorphism (rs6929846) of BTN2A1 was significantly associated with the prevalence of CKD in subject panels A (P = 0.0422; recessive model; odds ratio, 2.36) and B (P = 0.0386; dominant model; odds ratio, 1.21) with the T allele representing a risk for this condition.

CONCLUSION

Our results suggest that BTN2A1 may be a susceptibility gene for CKD in Japanese individuals.

109 RELATIONSHIP BETWEEN ULTRASONIC MORPHOLOGY OF CORPUS LUTEUM IN HOLSTEIN HEIFERS AND PREGNANCY RATE AFTER EMBRYO TRANSFER

Recipient animals for bovine embryo transfer (ET) are routinely selected according to the morphology of the corpus luteum (CL) estimated by rectal palpation. However, rectal palpation is not a precise method of diagnosing the functional status of a CL. Ovarian ultrasonography (US) may be used to improve such diagnoses. The aim of this study was to evaluate the relationship between ultrasonographic images of CL and pregnancy rates after ET in Holstein heifers to determine whether US can be used to select recipients for ET. Recipient heifers (n = 285) were selected by detection of natural oestrus or following oestrus synchronization using a progesterone-releasing intravaginal device (PRID; ASKA Pharmaceutical, Tokyo, Japan). Transrectal US was performed immediately before ET, on Days 6 to 8 of the oestrous cycle (oestrus = Day 0), using a B-mode scanner (HS1500V; Honda Electronics Co. LTD, Aichi, Japan) equipped with a 7.5-MHz linear-array transducer designed for intrarectal placement. A cross-sectional image of the maximal area of the CL and luteal cavity was obtained. The areas of the CL and luteal cavity were each calculated using the formula for the area of an ellipse (height/2 × width/2 × π). (1) Ultrasonic morphology of CL was classified into 3 types: without cavity (n = 128), with cavity (n = 145) and with blood clot (n = 12). (2) The luteal cavity was categorized into 3 groups: small (<100 mm2, n = 93), medium (100 ≤ x < 200 mm2, n = 32) and large (≥200 mm2, n = 20). (3) Luteinized tissue area (total area of CL minus the area of the luteal cavity) was categorized into 3 groups: small (<250 mm2, n = 61), medium (250 ≤ x < 350 mm2, n = 128) and large (≥350 mm2, n = 84). In vivo–produced embryos were transferred nonsurgically into the uterine horn ipsilateral to the CL. Pregnancy was determined by transrectal US on Days 30 to 40 of gestation. The pregnancy rates of each experimental group were analysed by logistic regression. In this study, the pregnancy rate did not differ significantly in each experimental group: (1) without cavity: 77.3% (99/128), with cavity: 75.2% (109/145) and blood clot: 75.0% (9/12); (2) small cavity: 73.1% (68/93), medium: 75.0% (24/32) and large: 85.0% (17/20). The mean area of the cavity was 100.8 ± 110.3 mm2 (mean ± standard deviation) and recipients with 0 to 539.7 mm2 sized cavities had successful pregnancies (observational range was 0 to 539.7 mm2). (3) The pregnancy rates of recipients that had small, medium and large luteinized tissue were 77.0% (47/61), 75.0% (96/128) and 77.4% (65/84), respectively. The mean area of luteinized tissue was 318.9 ± 90.3 mm2 and 155.0 to 620.0 mm2 sized luteinized tissue had pregnancy success (observational range was 132.8 to 620.0 mm2). In conclusion, the results from this study indicate that the presence of a luteal cavity or blood clot has no detrimental effect on pregnancy success after ET in Holstein heifers. Furthermore, no relationship was found between luteinized tissue area at the time of ET and pregnancy rate.

75 COMPARISON OF THE DG29TM ENZYME-LINKED IMMUNOSORBENT ASSAY KIT COMPARED WITH TRANSRECTAL ULTRASONOGRAPHY FOR EARLY PREGNANCY DIAGNOSIS FOLLOWING TRANSFER OF JAPANESE BLACK CATTLE EMBRYOS

In commercial embryo transfer industry, accurate early detection of pregnant and nonpregnant cows plays a key role in achieving an optimum calving-to-conception interval. The DG29TM enzyme-linked immunosorbent assay (ELISA) kit (Conception, Animal Reproduction Technologies, Beaumont, Canada) measures the level of pregnancy-related glycoproteins in blood that are linked to pregnancy. Here, we compared the DG29 kit with transrectal ultrasonography (TU) to evaluate the possibility of the clinical application of the ELISA kit for early pregnancy diagnosis. Embryos recovered from superovulated Japanese Black cows were transferred to 110 recipient Holstein heifers on Day 6 to 8 of the oestrous cycle (oestrus = Day 0). Pregnancy was diagnosed between Day 29 and Day 40 by TU with a 5.0/7.5-MHz linear array transducer (Tringa, Pie Medical Equipment B.V., Maastricht, the Netherlands). Blood samples were collected from the tail vein or artery into vacuum serum tubes after TU and serum was separated and stored at –30°C until the ELISA was performed. The ELISA results were interpreted as positive (pregnant, >1000 pg mL–1) or negative (nonpregnant, <300 pg mL–1). Ninety-nine of the 110 heifers were judged as pregnant or nonpregnant by TU. Seventy-six of the 99 heifers were judged as pregnant, in which fetuses were visualised clearly in the uterine horn. The following measures, sensitivity, specificity, predictive value and accuracy of pregnancy outcomes based on the ELISA results, were assessed by comparing with those based on the definite TU results. The values for sensitivity and specificity were 100% (76/76) and 91.3% (21/23), the positive and negative predictive value were 97.4% (76/78) and 100% (21/21), respectively and accuracy was 98.0% (97/99). On the other hand, chorioallantoic fluids in 11 of the 110 heifers were detected by TU around Day 30 of gestation, but fetuses were not identified or were unclearly visualised, which suggests that the embryos died during the peri-implantation period after transfer. Ten of the 11 heifers were classified as pregnant by the ELISA, but only 3 heifers were identified as pregnant with reexamination by later TU, which indicates that the pregnancy-related glycoproteins residue from embryo mortality was detected by the DG29 kit. However, the negative predictive value of the DG29 kit was 100% in this study. In conclusion, except for early embryonic death, the DG29 kit was highly accurate and suitable for clinical application in early pregnancy determination following transfer of Japanese Black cattle embryos.

A model to estimate the potential for a physical activity-induced reduction in healthcare costs for the elderly, based on pedometer/accelerometer data from the Nakanojo Study

The rising healthcare costs associated with an aging population have become an urgent fiscal problem. However, evidence of the efficacy of preventive programmes is limited, since almost all studies have involved only small numbers of highly selected participants. This article examines potential physical activity-induced decreases in healthcare expenses, applying a theoretical model to the Nakanojo Study of habitual physical activity and health in an entire elderly community. The Nakanojo Study has shown substantial associations of health with both step count and the duration of moderate effort (intensity >3 metabolic equivalents [METs]). Participants are classed as 'dependent' (n = 800) or 'independent' (n = 4400); the latter category is divided arbitrarily into quartiles, based on physical activity patterns (Q1-Q4; n = 1100 for each quartile). The five groups show a graded prevalence of various morbidities, including dependency, depression, osteoporosis, fractures, hypertension, diabetes mellitus, hyperlipidaemia, ischaemic heart diseases, cerebrovascular diseases, cancer and dementia. Consequently, annual healthcare expenditures (based on 2009 published Japanese costs associated with each of these conditions) differ by about yen (¥)197 900 ($US1979) per person between dependent individuals and those in group Q1, ¥20 700 ($US207) between Q1 and Q2, ¥14 600 ($US146) between Q2 and Q3, and ¥5300 ($US53) between Q3 and Q4. Accepting a causal relationship between physical activity and health, and assuming that an increase in physical activity induces a benefit that is uniform across conditions and diseases, respective morbidity prevalences and associated healthcare costs seem likely to decrease as physical activity increases. Thus, if the physical activity of only 5% of each group could be increased by a single ranking (pedometer/accelerometer scores of 2000 steps/day and 5-10 min/day at >3 METs and/or an adjusted questionnaire score of 10 MET hours/week), one might predict average savings across this population of about ¥12 600 ($US126) per person, or 3.7%, of total medical expenses, including ¥9800 ($US98) of public nursing care insurance costs and an additional ¥2800 ($US28) of national health insurance expenditures. The impact of various changes in the prevalence of physical activity can be simulated using our model. In principle, savings should increase if more people increase their physical activity, and/or the magnitude of individual increases in physical activity is greater. Nevertheless, our analysis suggests that if even a small fraction of individuals in the three least active groups were to make a single-rank increase in their habitual physical activity as a result of focused health support and the promotion of physical activity, a significant reduction in medical expenses might be anticipated, justifying investment in preventive programmes. We now propose to test the validity of the present simulations on a national basis, obtaining accurate and objective evidence of change in individual physical activity patterns using an advanced design of pedometer/accelerometer.

Measurement of human energy expenditure, with particular reference to field studies: an historical perspective

Over the years, techniques for the study of human movement have ranged in complexity and precision from direct observation of the subject through activity diaries, questionnaires, and recordings of body movement, to the measurement of physiological responses, studies of metabolism and indirect and direct calorimetry. This article reviews developments in each of these domains. Particular reference is made to their impact upon the continuing search for valid field estimates of activity patterns and energy expenditures, as required by the applied physiologist, ergonomist, sports scientist, nutritionist and epidemiologist. Early observers sought to improve productivity in demanding employment. Direct observation and filming of workers were supplemented by monitoring of heart rates, ventilation and oxygen consumption. Such methods still find application in ergonomics and sport, but many investigators are now interested in relationships between habitual physical activity and chronic disease. Even sophisticated questionnaires still do not provide valid information on the absolute energy expenditures associated with good health. Emphasis has thus shifted to use of sophisticated pedometer/accelerometers, sometimes combining their output with GPS and other data. Some modern pedometer/accelerometers perform well in the laboratory, but show substantial systematic errors relative to laboratory reference criteria such as the metabolism of doubly labeled water when assessing the varied activities of daily life. The challenge remains to develop activity monitors that are sufficiently inexpensive for field use, yet meet required accuracy standards. Possibly, measurements of oxygen consumption by portable respirometers may soon satisfy part of this need, although a need for valid longer term monitoring will remain.

Association of a polymorphism of BTN2A1 with type 2 diabetes mellitus in Japanese individuals

AIMS

We previously showed that the C→T polymorphism (rs6929846) of BTN2A1 was significantly associated with myocardial infarction in Japanese individuals by a genome-wide association study. Given that diabetes mellitus is an important risk factor for myocardial infarction, the association of rs6929846 of BTN2A1 with myocardial infarction might be attributable, at least in part, to its effect on susceptibility to diabetes. The purpose of this study was to examine the relation of rs6929846 of BTN2A1 to Type 2 diabetes mellitus.

METHODS

A total of 8650 Japanese individuals from two independent subject panels were examined: Panel A comprised 1141 individuals with Type 2 diabetes and 3161 control subjects and panel B comprised 1664 individuals with Type 2 diabetes and 2684 control subjects.

RESULTS

The chi-square test revealed that rs6929846 of BTN2A1 was significantly related to the prevalence of Type 2 diabetes in subject panel A (P = 0.0002) and subject panel B (P=0.006). Multivariable logistic regression analysis with adjustment for age, sex, body mass index and smoking status revealed that rs6929846 was significantly associated with Type 2 diabetes (P = 0.0006; odds ratio 1.25) in all individuals, with the T allele representing a risk factor for this condition. Multiple regression analysis with adjustment for age, sex and body mass index revealed that rs6929846 was significantly (P=0.04) related to blood glycosylated haemoglobin content in control subjects.

CONCLUSIONS

BTN2A1 may be a susceptibility gene for Type 2 diabetes in Japanese individuals.

Association of a polymorphism of BTN2A1 with hypertension in Japanese individuals

BACKGROUND

We previously showed that the C→T polymorphism (rs6929846) in butyrophilin, subfamily 2, member A1 gene (BTN2A1) was associated with myocardial infarction in Japanese individuals. Given that hypertension is a major risk factor for myocardial infarction, the association of rs6929846 of BTN2A1 with myocardial infarction might be attributable, at least in part, to its effect on susceptibility to hypertension. We have thus examined the relation of rs6929846 of BTN2A1 to hypertension in Japanese individuals.

METHODS

A total of 8,567 Japanese individuals from two independent subject panels were examined: Subject panels A and B comprised 2,317 hypertensive individuals and 1,933 controls, and 2,911 hypertensive individuals and 1,406 controls, respectively. The genotype of rs6929846 was determined by a method that combines the PCR and sequence-specific oligonucleotide probes with suspension array technology.

RESULTS

Multivariable logistic regression analysis with adjustment for covariates revealed that rs6929846 of BTN2A1 was significantly associated with hypertension in subject panel A (P = 2.6 × 10(-6); odds ratio, 1.69) and in subject panel B (P = 0.0284; odds ratio, 1.24), with the T allele representing a risk factor for hypertension. The rs6929846 was associated with systolic blood pressure (BP) in subject panels A (P = 0.0063) and B (P = 0.0115) and with diastolic BP in subject panel B (P = 0.0323), with the T allele being related to high BP.

CONCLUSIONS

BTN2A1 may be a susceptibility gene for hypertension in Japanese individuals. Determination of genotype for this polymorphism may prove informative for assessment of the genetic risk for hypertension.

How many steps/day are enough? For older adults and special populations

Older adults and special populations (living with disability and/or chronic illness that may limit mobility and/or physical endurance) can benefit from practicing a more physically active lifestyle, typically by increasing ambulatory activity. Step counting devices (accelerometers and pedometers) offer an opportunity to monitor daily ambulatory activity; however, an appropriate translation of public health guidelines in terms of steps/day is unknown. Therefore this review was conducted to translate public health recommendations in terms of steps/day. Normative data indicates that 1) healthy older adults average 2,000-9,000 steps/day, and 2) special populations average 1,200-8,800 steps/day. Pedometer-based interventions in older adults and special populations elicit a weighted increase of approximately 775 steps/day (or an effect size of 0.26) and 2,215 steps/day (or an effect size of 0.67), respectively. There is no evidence to inform a moderate intensity cadence (i.e., steps/minute) in older adults at this time. However, using the adult cadence of 100 steps/minute to demark the lower end of an absolutely-defined moderate intensity (i.e., 3 METs), and multiplying this by 30 minutes produces a reasonable heuristic (i.e., guiding) value of 3,000 steps. However, this cadence may be unattainable in some frail/diseased populations. Regardless, to truly translate public health guidelines, these steps should be taken over and above activities performed in the course of daily living, be of at least moderate intensity accumulated in minimally 10 minute bouts, and add up to at least 150 minutes over the week. Considering a daily background of 5,000 steps/day (which may actually be too high for some older adults and/or special populations), a computed translation approximates 8,000 steps on days that include a target of achieving 30 minutes of moderate-to-vigorous physical activity (MVPA), and approximately 7,100 steps/day if averaged over a week. Measured directly and including these background activities, the evidence suggests that 30 minutes of daily MVPA accumulated in addition to habitual daily activities in healthy older adults is equivalent to taking approximately 7,000-10,000 steps/day. Those living with disability and/or chronic illness (that limits mobility and or/physical endurance) display lower levels of background daily activity, and this will affect whole-day estimates of recommended physical activity.

Expression profiles of genes associated with viral entry in HCV-infected human liver

Recent studies have demonstrated that several cellular factors are involved in entry of hepatitis C virus (HCV) into host cells. Detailed gene expression profiles of these factors in HCV-infected livers have not been reported for humans. Transcriptional levels of LDL receptor (LDLR), CD81, scavenger receptor class B type I (SR-BI), claudin-1, and occludin genes in liver samples from patients with chronic hepatitis C were investigated. Serum levels of LDL-cholesterol (LDL-C) and HCV core antigen were also evaluated, and expression of claudin-1 and occludin were immunohistochemically analyzed. Compared with normal liver, transcription of LDLR and claudin-1 genes was significantly suppressed (P < 0.0001) and occludin transcription was significantly up-regulated in HCV-infected livers (P < 0.0001). Significant positive correlations were found for LDLR versus occludin, LDLR versus claudin-1, occludin versus claudin-1, and CD81 versus SR-BI in HCV-infected (P = 0.0012, P < 0.0001, P = 0.0004, and P < 0.0001, respectively) and normal livers (P < 0.0001, P = 0.0051, P < 0.0001, and P < 0.0001, respectively). Positive correlation was observed between serum levels of HCV core antigen and LDL-C (P = 0.0147), with their levels negatively correlated to LDLR (P = 0.0270 and P = 0.0021, respectively). Immunohistochemically, hepatocellular expression of claudin-1 and occludin was increased in HCV-infected livers. Different levels of expression were demonstrated at the mRNA and protein levels for occludin and claudin-1 in HCV-infected and normal livers. Correlation of elements associated with viral entry was comparable in HCV-infected and normal livers.

Association of a polymorphism of BTN2A1 with dyslipidemia in East Asian populations

We previously identified rs6929846 of the butyrophilin, subfamily 2, member A1 gene (BTN2A1) as a susceptibility locus for myocardial infarction in Japanese individuals by a genome-wide association study. The aim of the present study was to examine the relation of the rs6929846 polymorphism of BTN2A1 to dyslipidemia in Japanese and Korean populations, given that dyslipidemia is an important risk factor for myocardial infarction. A total of 10,953 individuals from three independent subject panels were examined. The relations of the rs6929846 polymorphism of BTN2A1 to serum concentrations of triglycerides, high-density lipoprotein (HDL)-cholesterol and low-density lipoprotein (LDL)-cholesterol were examined in each subject panel. The C→T polymorphism (rs6929846) of BTN2A1 was significantly associated with serum concentrations of triglycerides in Japanese subject panels A (P=0.0004) and B (P=0.0010), and in the Korean population (P=0.0095), with the minor T allele being related to an increased serum concentration of triglycerides. The rs6929846 was associated with serum concentrations of HDL-cholesterol in Japanese subject panels A (P=0.0047) and B (P=0.0015), with the T allele being related to a decreased serum concentration of HDL-cholesterol, but not in the Korean population. This polymorphism was associated with the serum concentration of LDL-cholesterol only in Japanese subject panel B (P=0.0059), with the T allele being related to an increased serum concentration of LDL-cholesterol. The results suggest that BTN2A1 may be a susceptibility gene for hypertriglyceridemia in East Asian populations and for low serum HDL-cholesterol in the Japanese population.