Biomedical subjects

Mayumi Yoshioka

Publications and source records attributed to Mayumi Yoshioka.

12 recordsLinked to original sources

PubMed2006

Nutraceutical supplementation: effect of a fermented papaya preparation on redox status and DNA damage in healthy elderly individuals and relationship with GSTM1 genotype: a randomized, placebo-controlled, cross-over study.

Our study group consisted of 54 elderly patients without major invalidating diseases who were randomly divided into two fully matched groups. Group A was given a certified fermented papaya preparation 9 g/day by mouth, while group B received placebo. Treatment was carried out in a cross-over manner with a 3-month supplementation followed by a 6-week washout period. Blood samples were drawn at entry and on a monthly basis to check routine parameters, redox status, and 8-OHdG in circulating leukocyte DNA. Polymorphism analysis of GSTM1 was carried out as well. The glutathune-S transferase M1 (GSTM1) genotype was null (-) in 40% and 46% of groups A and B, respectively. GSTM1 (-) smokers had a significantly higher level of plasma DNA adducts and leukocytes level of 8-OHdG than their GSTM1 (+) counterparts (P < 0.01). There was a weak correlation between cigarettes smoked/day and DNA adduct (r: 0.61, P < 0.05), which also correlated with antioxidant concentrations, but only in GSTM1 (-) smokers (P < 0.01). The fermented papaya preparation (FPP)-supplemented group showed a significant enhancement of the antioxidant protection (P < 0.01 vs. A) within the subgroups with GSTM1 (-) and of plasma DNA adduct, irrespective of the GSTM1 genotype. Only the GSTM1 (-) subgroup was the one that, under FPP treatment, increased lymphocyte 8-OHdG (P < 0.01). Such preliminary data show that FPP is a promising nutraceutical for improving antioxidant-defense in elderly patients even without any overt antioxidant-deficiency state while helping explain some inconsistent results of prior interventional studies.

8-Hydroxy-2'-Deoxyguanosine↗

PubMed2005

Regulation of hypothalamic gene expression by glucocorticoid: implications for energy homeostasis.

The present study investigated the hypothalamic gene expressions regulated by glucocorticoids (GC), key hormones in energy homeostasis. Using the serial analysis of gene expression (SAGE) method, we studied the effects of adrenalectomy (ADX) and GC on the transcriptomes of mouse hypothalamus. Approximately 180,000 SAGE tags, which correspond to 50,000 tag species, were isolated from each group of intact or adrenalectomized mice as well as 1, 3, and 24 h after GC injection. ADX upregulated diazepam binding inhibitor gene expression while downregulating vomeronasal 1 receptor D4, genes involved in mitochondrial phosphorylation (cytochrome-c oxidase 1 and NADH dehydrogenase 3), 3beta-hydroxysteroid dehydrogenase-1, and prostaglandin D2 synthase. GC increased the gene expression levels of dehydrogenase/reductase member 3, prostaglandin D2 synthase, solute carrier family 4 member 4, and five cytoskeletal proteins including myosin light chain phosphorylatable fast and troponin C2 fast. On the other hand, GC reduced the mRNA levels of calmodulin 1 and expressed sequence tag similar to calmodulin 2, ATP synthase F0 subunit 6, and solute carrier family 4 member 3. Moreover, 7 uncharacterized and 43 novel transcripts were modulated by ADX and GC. The present study has identified genes that may regulate hypothalamic systems governing energy balance in response to ADX and GC.

Adrenalectomy↗

PubMed2005

The top 10 most abundant transcripts are sufficient to characterize the organs functional specificity: evidences from the cortex, hypothalamus and pituitary gland.

Using serial analysis of gene expression, we have identified the most abundant mRNA transcripts in parietal cortex, hypothalamus and pituitary gland in adult male mice. High mRNA abundance of neurogranin (cell signalling and communication) was characteristic of the cortex. The common molecular features of cortex and hypothalamus were high abundance of mRNA encoding mitochondrial enzymes such as reduced form of nicotinamide adenine dehydrogenase (NADH) 4 and cytochrome c oxidase 2 (energy metabolism), brain creatine kinase (energy metabolism) and myelin basic protein (cell structure). In the hypothalamus, mRNA levels of apolipoprotein E (lipid metabolism), prostaglandin D2 (cell signalling and communication) and secreted acidic cysteine-rich glycoprotein (extracellular matrix) were especially high. A common molecular feature of the hypothalamus and pituitary was high mRNA abundance of guanine nucleotide binding protein alpha stimulating complex locus (cell signalling and cell communication). The pituitary gland was characterized by high expression of genes encoding hormones such as growth hormone, pro-opiomelanocortin and prolactin, as well as neuronatin (cell differentiation) and four potential novel transcripts. Thus, these results show that the cortex, hypothalamus and pituitary gland can be specifically characterized according to their 10 most abundant transcripts. In addition, the current study serves as a basis for future studies on the potential novel transcripts and the transcripts with unclear functions despite their extremely high abundance, as well as studies on physiology and pathology of the two brain regions and pituitary gland.

Animals↗

PubMed2005

Sexually dimorphic gene expression in the hypothalamus, pituitary gland, and cortex.

We examined sex differences in the transcriptomes of hypothalamus, pituitary gland, and cortex of male and female mice using serial analysis of gene expression. In total 940,669 tags were sequenced. In hypothalamus, 3 transcripts are differentially expressed by gender, including growth hormone (neuromodulation) and 3beta-hydroxysteroid dehydrogenase-1 (steroidogenesis). In pituitary gland, 43 transcripts are differentially expressed, including RAS guanyl-releasing protein 2 (cell signaling), ornithine transporter (mitochondrial transport), H3 histone family 3B (chromatin structure), heterogeneous nuclear ribonucleoprotein U (chromatin remodeling), NADH dehydrogenase (mitochondrial oxidative phosphorylation), neuronatin (cell differentiation), and ribosomal protein S27a (protein metabolism). EST X (inactive)-specific transcript antisense is expressed at a higher level in the three female organs, whereas growth hormone and NADH dehydrogenase are expressed at higher levels in female cortex. Thus, the current study has characterized key sexual dimorphisms in the transcriptomes of the hypothalamus, pituitary, and cortex.

Animals↗

PubMed2005

Regulation of global gene expression by ovariectomy and estrogen in female adipose tissue.

OBJECTIVE: To study the effects of ovariectomy (OVX) and estrogen replacement on global gene expression in white adipose tissue. RESEARCH METHODS AND PROCEDURES: Female mice were randomly divided into four groups: 1) intact, 2) OVX, 3) OVX plus estradiol (E2) injection 3 hours before death (E(2)-3 hours), and 4) E(2)-24 hours. The serial analysis of gene expression was performed to detect the transcriptomic changes. RESULTS: A total of 15 transcripts, including several novel transcripts, were found to be modulated by OVX or E2 (p<0.05). Secreted acidic cysteine-rich glycoprotein, which regulates the extracellular matrix (ECM) components, was increased after OVX. Moreover, OVX up-regulated several transcripts involved in ECM, such as procollagen types Ialpha1 and 2. In cell defense, glutathione peroxidase 3 was lower in OVX than in intact mice. Cytochrome c oxidase I and three novel transcripts were up-regulated by estrogen treatment. DISCUSSION: This study underlines the importance of cell shape and ECM regulation by OVX on adiposity. Moreover, some novel transcripts may also play a relevant role in OVX-induced obesity and estrogen therapy.

Adipose Tissue↗

PubMed2004

Adipose tissue transcriptome by serial analysis of gene expression.

OBJECTIVE: To describe the genomic expression profile or transcriptome of adipose tissue using the serial analysis of gene expression method. RESEARCH METHODS AND PROCEDURES: The serial analysis of gene expression strategy is based on isolation of short sequences (tags), which usually correspond to unique transcripts, and on their concatenation into long DNA molecules, which are then cloned and sequenced. Experiments were performed with mRNA from retroperitoneal adipose tissue of male C57BL6 mice. RESULTS: We isolated 45,996 tags corresponding to more than 17,000 different genes. Eighty-eight genes were expressed at more than 0.1% of the total population and represented 26% of the mRNA population identified. The most expressed genes were: carbonic anhydrase 3 (1.97%), cytochrome c oxidase (COX) 1 (1.47%), COX2 (1.25%), diazepam binding inhibitor (1.04%), a novel transcript (0.87%), COX3 (0.55%), fatty acid-binding protein 4 (0.55%), and NADH dehydrogenase 4 (0.52%). Other genes known to be expressed in adipose tissue, such as uncoupling protein 2, angiotensinogen, adipsin, and insulin-like growth factor 1, were found at a lower level. Several tags corresponding to novel transcripts were also found. DISCUSSION: To our knowledge, the present results provide for the first time a quantitative description of the transcriptome in adipose tissue.

Adipose Tissue↗

PubMed2004

The use of uniaxial accelerometry for the assessment of physical-activity-related energy expenditure: a validation study against whole-body indirect calorimetry.

Assessing the total energy expenditure (TEE) and the levels of physical activity in free-living conditions with non-invasive techniques remains a challenge. The purpose of the present study was to investigate the accuracy of a new uniaxial accelerometer for assessing TEE and physical-activity-related energy expenditure (PAEE) over a 24 h period in a respiratory chamber, and to establish activity levels based on the accelerometry ranges corresponding to the operationally defined metabolic equivalent (MET) categories. In study 1, measurement of the 24 h energy expenditure of seventy-nine Japanese subjects (40 (SD 12) years old) was performed in a large respiratory chamber. During the measurements, the subjects wore a uniaxial accelerometer (Lifecorder; Suzuken Co. Ltd, Nagoya, Japan) on their belt. Two moderate walking exercises of 30 min each were performed on a horizontal treadmill. In study 2, ten male subjects walked at six different speeds and ran at three different speeds on a treadmill for 4 min, with the same accelerometer. O2 consumption was measured during the last minute of each stage and was expressed in MET. The measured TEE was 8447 (SD 1337) kJ/d. The accelerometer significantly underestimated TEE and PAEE (91.9 (SD 5.4) and 92.7 (SD 17.8) % chamber value respectively); however, there was a significant correlation between the two values (r 0.928 and 0.564 respectively; P<0.001). There was a strong correlation between the activity levels and the measured MET while walking (r(2) 0.93; P<0.001). Although TEE and PAEE were systematically underestimated during the 24 h period, the accelerometer assessed energy expenditure well during both the exercise period and the non-structured activities. Individual calibration factors may help to improve the accuracy of TEE estimation, but the average calibration factor for the group is probably sufficient for epidemiological research. This method is also important for assessing the diurnal profile of physical activity.

Acceleration↗

PubMed2004

Maximum tolerable dose of red pepper decreases fat intake independently of spicy sensation in the mouth.

Dietary red pepper suppresses energy intake and modifies macronutrient intake. We have investigated whether a stimulus in the mouth and the sensation of spiciness are necessary for red pepper-induced changes in energy and macronutrient intake in human volunteers. In a preliminary test, sixteen Japanese male volunteers tasted samples of a soup with graded doses of red pepper in order to define a moderate and a maximum tolerable (strong) dose of red pepper. On the day of the experiment, a standardised breakfast was given to the volunteers. At lunchtime, the subjects ingested one of four experimental soups containing either a placebo, a moderate or a strong dose of red pepper plus placebo capsules, or a placebo soup plus capsules delivering a strong dose of red pepper. The rest of the meal was given ad libitum to all subjects. The amount of food, protein and carbohydrate ingested was similar for all conditions. Energy and fat intake were similar after the ingestion of the moderate soup compared with placebo. However, the strong soup significantly lowered fat intake compared with placebo (P=0.043), and ingestion of strong capsules also tended to suppress it (P=0.080). Moreover, energy intake after strong soup and capsules tended to be lower than placebo (P=0.089 and 0.076, respectively). The present results indicate that the maximum tolerable dose is necessary to have a suppressive effect of red pepper on fat intake. The main site of the action of red pepper is not in the mouth.

Adult↗

PubMed2004

The difference between the basal metabolic rate and the sleeping metabolic rate in Japanese.

Previous studies have demonstrated the difference between the basal metabolic rate (BMR) and the sleeping metabolic rate (SMR): however, the difference in the Japanese population has not yet been explored. This study examined the relationship between the BMR and SMR in ninety-four healthy Japanese subjects (37 males and 57 females, 39 +/- 12 y of age and 22.0 +/- 7.4% body fat) in a respiratory chamber. The SMR was significantly lower than the BMR (1416 +/- 245 vs. 1492 +/- 256 kcal/d): however, there was a highly significant correlation between the two (r = 0.867; p < 0.001). The ratio of SMR/BMR largely varied among individuals (0.95 +/-0.08, 8.4% of the coefficient of variation). The ratio was significantly lower in males than in females (0.93 +/- 0.10 vs. 0.97 +/- 0.06, p < 0.05). None of the anthropometric measures (age, weight, body mass index, body surface area or percent body fat) correlated with the ratio. These results showed that SMR was 95%, of BMR on average in a healthy Japanese group. However, when applied over a longer time period (24 h or more), the difference tends to become negligible for most analyses in a group. Although the difference between SMR and BMR will induce a 5% gap of physical activity level defined as the total energy expenditure divided by the BMR or SMR, this factor seems to have little practical importance in epidemiological research.

Adult↗

PubMed2003

Serial analysis of gene expression in the skeletal muscle of endurance athletes compared to sedentary men.

Physical exercise produces several adaptive changes in skeletal muscle. However, the molecular mechanisms of these effects are poorly understood. We performed serial analysis of gene expression (SAGE) to quantify the global gene expression profile in sedentary and endurance-trained muscle. A total of 10869 SAGE tags was sequenced and represented 4727 genes. The genes most expressed in muscle are mainly involved in contraction and energy metabolism. Thirty-three genes were differentially expressed between endurance athletes and sedentary individuals. Four genes such as myosin binding protein C fast-type, glycogen phosphorylase, and pyruvate kinase were expressed less in endurance athletes, whereas eight genes coding for expressed sequence tag similar to (EST) crystallin alpha B, EST myosin light chain 2, EST surfactant pulmonary-associated protein A1, EST thrombospondin, EST fructose-bisphosphate aldolase A, EST cytochrome oxidase 1, NADH dehydrogenase 3, and G8 protein were up-regulated. Most of the up-regulated tags corresponded to novel genes. On the other hand, different isoforms of fructose-bisphosphate aldolase A were also differentially expressed. The current study underlying the most highly expressed genes allows a better understanding of global muscle characteristics in normal and endurance-trained individuals. Moreover, the current data suggest novel candidate genes that may be responsible for enhanced endurance performance.

Adult↗

PubMed2003

The role of exercise physical activity in varying the total energy expenditure in healthy Japanese men 30 to 69 years of age.

This study was designed to examine 1) the role of exercise physical activity (EPA), and then 2) physical fitness and body composition upon variation of the total energy expenditure (TEE) in healthy Japanese men aged 30 to 69 y (n = 40). EPA and TEE were assessed over 14 d using an accelerometer and a doubly labeled water (DLW) method, respectively. Basal metabolic rate (BMR) was measured after 10 h fasting on the morning of the day of DLW dosing. Physical activity-induced energy expenditure (PAEE) was calculated by subtracting BMR and diet-induced thermogenesis (DIT = 101 TEE) from TEE. EPA was subdivided into three intensities: low, moderate and high and the accumulated duration (time expressed in minutes) of each of these was calculated. Body composition and physical fitness (VO2max) were determined using an underwater weighing method and a treadmill exercise test, respectively. BMR (mean +/- SD: 1,459 +/- 181 kcal/d) declined significantly with age (r = -0.37. p < 0.05), but PAEE (946 +/- 320 kcal/d) and TEE (2,672 +/- 369 kcal/d) did not. A multiple stepwise regression analysis was used to develop an empirical model that relates energy expenditure measured by the DLW (TEE) to age, height, body mass index, FM, FFM, percentage body fat, VO2max, and accumulated duration spent for low-, moderate-, and high-intensity EPA. The results revealed that FFM and high-intensity EPA were identified as important determinants of TEE and accounted for 51%. We may therefore conclude that 1) high-intensity EPA appears to be relevant in determining TEE, especially among active individuals, and 2) body composition was more important than physical fitness in determining TEE in this population.

Adult↗

PubMed2002

Validation of three alternative methods to measure total energy expenditure against the doubly labeled water method for older Japanese men.

In a previous study using young Japanese men as subjects, Ebine et al. found that accelerometer (AC) represents a promising technique for measuring free-living total energy expenditure (TEE) when compared to activity records (AR) and heart rate monitoring (HR). Thus, the present study was designed to validate the use of an AC and to determine whether or not the previous findings regarding the three alternative field methods (AC, AR, and HR) could be extended to older Japanese men (n = 24; mean +/- SD age 48 +/- 10 y, body mass index 23.1 +/- 2.7 kg/m2 and body fat 18.7 +/- 4.8%). TEE values obtained over a 3 d period by AR, HR, and AC (3dAC), and AC over a 14 d period (14dAC) were simultaneously validated against TEE measured by the doubly labeled water (DLW) method applied within a 14 d period. TEE values obtained by AR, HR, 3dAC, and 14dAC ranged from 1,750 to 3,447 kcal/d, 1,691 to 5,286 kcal/d, 1,716 to 2,765 kcal/d, and 1,700 to 2,855 kcal/d, respectively. Expenditures obtained by HR were similar to those obtained using the DLW method, with a mean difference of 57 +/- 603 kcal/d (2%), but those obtained using AR, 3dAC, and 14dAC differed substantially from the DLW method, with mean differences of -335 +/- 289 kcal/d (12%), -542 +/- 249kcal/d (-19%), and -566 +/- 223kcal/d (-20%), respectively. AR, HR, 3dAC, and 14dAC were significantly correlated with the DLW method, with r values of 0.76 (p < 0.0001), 0.67 (p < 0.001), 0.78 (p < 0.0001), and 0.83 (p < 0.0001), respectively. Intra-individual variation indicated by the coefficient of variation (CV) was significantly higher for HR (15 +/- 11%, p < 0.001) than for AR (7 +/- 4%), 3dAC (7 +/- 5%), and 14dAC (8 +/- 31%). The same findings were obtained using Bland and Altman plots at the population level. Interestingly, 3dAC and 14dAC were significantly correlated with r = 0.97 (p < 0.0001), with a lower mean difference of 24 kcal/d. These results suggest that, same as the previous study, AC is superior to HR in estimating TEE, and seems to be satisfactory for estimation at both group and individual levels, particularly for large-scale studies of older individuals when compared to the DLW method. However, some modifications of the AC method may be needed to compensate for the underestimation of TEE.

Adult↗