Biomedical subjects

Low-Tone Ho

Publications and source records attributed to Low-Tone Ho.

At least 37 records · Page 2Linked to original sources

PubMed2005

Effects of parathyroid hormone on plasma zinc concentration in rat with chronic renal failure.

Although both secondary hyperparathyroidism (HPT) and hypozincemia are commonly observed in humans and animals with chronic renal failure (CRF), the relationship between secondary HPT and hypozincemia is little delineated. The present study was designed to examine whether the elevated plasma parathyroid hormones (PTH) levels do affect the disposition of extrarenal zinc and decrease plasma zinc level in CRF rats. The experiment was performed in normal and CRF rats with intact parathyroid gland and parathyroidectomized (PTX), using an acute zinc load alone or in combination with PTH infusion in five groups of rats: normal control, CRF control, CRF + PTH, CRF + PTX and CRF + PTX + PTH. Five sixths nephrectomy was used to produce CRF. All rats were infused with 0.05 mg/kg/min ZnSO4 alone or in combination with 10 microg/kg/min PTH through intravenous infusion for 90 min with serial monitoring of plasma zinc levels every 30 min. The alteration of plasma interleukin-6 (IL-6) levels and the effect of zinc levels in red blood cells (RBCs), as well as the output of bile juice zinc and urinary zinc excretion during the 90-min infusion were also examined. After 90-min infusion, liver tissue was harvested to determine its contents of zinc and metallothionein (MT). During zinc sulfate infusion, the responses of plasma zinc concentration in PTH-combined infusion groups markedly decreased as compared with those of the non-PTH-combined infusion groups, especially in the CRF rats with PTX. However, when zinc sulfate alone was infused, the response of plasma zinc concentration was found to increase in CRF rats with PTX as compared with that of the CRF control rats. PTH infusion groups significantly increased the levels of plasma IL-6 (P < 0.05), but it did not alter the levels of RBC zinc and the secretion of bile zinc during the 90-min infusion. After 90-min zinc sulfate infusion, higher liver zinc and MT contents were found in CRF control, CRF + PTH and CRF + PTX + PTH rats, but were [corrected] not found in the CRF + PTX rats. Zinc sulfate infused alone was found to increase the excretion of basal zinc in bile juice and urine, in both normal and CRF rats. The percentage of zinc load translocated out from the plasma during 90-min zinc sulfate infusion significantly rises in CRF rats and CRF rats with PTH-combined infusion as compared with normal control rats. However, in CRF rats with PTX, the percentage of zinc load translocated out from plasma during 90-min zinc sulfate infusion was similar to that in the normal control rats. Therefore, we suggested that in CRF rats, the excessive secretion of PTH may play a role in the pathogenesis of hypozincemia because PTH enhanced extrarenal zinc disposal.

Animals↗

PubMed2005

Differential generators for N20m and P35m responses to median nerve stimulation.

To study the spatial and behavioral dynamics of cortical sources for N20m and P35m at varying stimulus intensities, we measured neuromagnetic cortical responses to left electric median nerve stimulation at the wrist in 17 male healthy adults. The stimulus intensity levels were individually determined according to sensory threshold (ST) for perceiving electric pulses. Using equivalent current dipole (ECD) modeling, we analyzed the peak latencies, amplitudes, and locations of ECDs from 14 subjects for N20m and P35m elicited at 2 ST, 3 ST, and 4 ST. Compared with N20m, P35m was localized 3.3 +/- 0.6 mm more superiorly at 2-4 ST, and 2.9 +/- 1.2 mm more medially at 3-4 ST. Superimposed over subjects' own MR images, N20m ECDs were localized in the area of 3b contralateral to stimulus side in all 17 subjects at 3 ST, whereas P35m ECDs were localized either in the postcentral (in 14 subjects) or in the precentral areas (in 3 subjects). We found no clear correlation between N20m and P35m in terms of peak latencies as well as the corresponding growth of activation strengths along with stepwise increase in stimulus intensity. Our results imply that the two early SEF components, N20m and P35m, have differential cortical generators, with distinctive neurophysiological behaviors in response to varying stimulus intensity levels.

Adult↗

PubMed2005

Insulin-like growth factor-1 increases endothelin receptor A levels and action in cultured rat aortic smooth muscle cells.

Insulin is known to cause an increase in endothelin-1 (ET-1) receptors in vascular smooth muscle cells (SMCs), but the effect of insulin-like growth factor 1 (IGF-1) on ET-1 receptor expression is not known. We therefore carried out the present study to determine the effect of IGF-1 on the binding of ET-1 to, and ET type A receptor (ETAR) expression and ET-1-induced 3H-thymidine incorporation in, vascular SMCs. In serum-free medium, IGF-1 treatment increased the binding of 125I-ET-1 to SMC cell surface ET receptors from a specific binding of 20.1%+/-3.1% per mg of protein in control cells to 45.1%+/-8.6% per mg of protein in cells treated with IGF-1 (10 nM). The effect of IGF-1 was dose-related, with a significant effect (1.4-fold) being seen at 1 nM. The minimal time for IGF-1 treatment to be effective was 30 min and the maximal effect was reached at 6 h. Immunoblotting analysis showed that ETAR expression in IGF-1-treated cells was increased by 1.7-fold compared to controls. Levels of ETAR mRNA measured by the RT-PCR method and Northern blotting were also increased by 2-fold in IGF-1-treated SMCs. These effects of IGF-1 were abolished by cycloheximide or genistein. Finally, ET-1-stimulated thymidine uptake and cell proliferation were enhanced by IGF-1 treatment, with a maximal increase of 3.2-fold compared to controls. In conclusion, in vascular SMCs, IGF-1 increases the expression of the ET-1 receptor in a dose- and time-related manner. This effect is associated with increased thymidine uptake and involves tyrosine kinase activation and new protein synthesis. These findings support the role of IGF-1 in the development of atherosclerotic, hypertensive, and diabetic vascular complications.

Animals↗

PubMed2005

Hemispheric balance in coding speech and non-speech sounds in Chinese participants.

To study the role of neuromagnetic auditory approximately 100-ms responses (N100m) in phonetic processing, we recorded N100m in 24 right-handed Chinese participants using a whole-head neuromagnetometer. The stimuli included vowel /a/ and consonant-vowels /ba/ and /da/, spoken by one Chinese speaker, and a 1-kHz tone. N100m to tones was larger in the right hemisphere, whereas that to speech sounds was bilaterally similar. The amplitude ratio of speech to non-speech N100m was larger in the left hemisphere. N100m dipoles in the left hemisphere were approximately 2 mm more anterior for speech than for tone stimuli. The results suggest that N100m reflects both acoustics and phonetic processing. Moreover, the ratio of speech to non-speech activation in individual hemispheres may be useful for language lateralization.

Acoustic Stimulation↗

PubMed2005

Angiotensin II enhances insulin sensitivity in vitro and in vivo.

The renin-angiotensin system plays a critical role in the pathogenesis of obesity, obesity-associated hypertension, and insulin resistance. However, the biological actions of angiotensin II (AII) on insulin sensitivity remain controversial. Because angiotensinogen and AII receptors are expressed on adipose tissue, we investigated the effect of AII on the insulin sensitivity of isolated rat adipocytes. The results of a receptor binding assay showed the maximal AII binding capacity of adipocytes to be 8.3 +/- 0.9 fmol/7 x 10(6) cells and the dissociation constant to be 2.72 +/- 0.11 nM. Substantial expression of both type 1 and 2 AII (AT1 and AT2) receptors was detected by RT-PCR. AII had no effect on basal glucose uptake, but significantly potentiated insulin-stimulated glucose uptake; this effect was abolished by the AT1 antagonist, losartan. In addition, AII did not alter the insulin binding capacity of adipocytes, but increased insulin-stimulated tyrosine phosphorylation of the insulin receptor beta-subunit, Akt phosphorylation, and translocation of glucose transporter 4 to the plasma membrane. AII potentiated insulin-stimulated glucose uptake through the AT1 receptor and by alteration of the intracellular signaling of insulin. Intraperitoneal injection of Sprague Dawley rats with AII increased insulin sensitivity in vivo. In conclusion, we have shown that AII enhances insulin sensitivity both in vitro and in vivo, suggesting that dysregulation of the insulin-sensitizing effect of AII may be involved in the development of insulin resistance.

Adipocytes↗

PubMed2005

Endothelin-1 induces lipolysis in 3T3-L1 adipocytes.

Endothelin-1 (ET-1) affects glucose uptake in adipocytes and may play an important role in adipose physiology. One of the principal functions of adipose tissue is the provision of energy substrate through lipolysis. In the present study, we investigated the effects of ET-1 on lipolysis in 3T3-L1 adipocytes. When glycerol release in the culture medium was measured as an index of lipolysis, the results showed that ET-1 caused a significant increase that was time and dose dependent. With a concentration of 10 nM ET-1, stimulation of glycerol release plateaued after 4 h of exposure. This effect was inhibited by the ETA receptor antagonist BQ-610 (10 microM) but not by the ETB receptor antagonist BQ-788 (10 microM). To further explore the underlying mechanisms of ET-1 action, we examined the involvement of the cAMP-dependent protein kinase A-mediated, phospholipase A2 (PLA2)-mediated, protein kinase C (PKC)-mediated, phosphatidylinositol 3 (PI 3)-kinase-mediated, and the mitogen-activated protein kinase (MAPK)-mediated pathways. Inhibition of adenylyl cyclase activation by SQ-22536 (100 microM) did not block ET-1-induced lipolysis. Pretreatment of adipocytes with the PLA2 inhibitor dexamethasone (100 nM), the PKC inhibitor H-7 (6 microM), or the PI 3-kinase inhibitor wortmannin (100 nM) also had no effect. ET-1-induced lipolysis was blocked by inhibition of extracellular signal-regulated kinase (ERK) activation using PD-98059 (75 microM), whereas a p38 MAPK inhibitor (SB-203580; 20 microM) had no effect. Results of Western blot further demonstrated that ET-1 induced ERK phosphorylation. These data show that ET-1 induces lipolysis in 3T3-L1 adipocytes via a pathway that is different from the conventional cAMP-dependent pathway used by isoproterenol and that involves ERK activation.

3T3-L1 Cells↗

PubMed2005

Resistin mRNA levels are downregulated by estrogen in vivo and in vitro.

Resistin, a hormone secreted by adipocytes, is suggested to be an important link between obesity and diabetes. The aim of this study was to evaluate the regulatory effect of estrogen on adipocyte resistin gene expression in ovariectomized (OVX) rats and in isolated rat adipocytes in vitro. Subcutaneous injection of estradiol benzoate reduced resistin mRNA levels in adipocytes isolated from the inguinal, parametrial, perirenal, retroperitoneal, or periovarian fat deposits of OVX rats, while an in vitro study showed that estradiol treatment decreased resistin mRNA levels in cultured rat periovarian fat adipocytes. Results of Western blotting analysis also showed that estrogen decreased adipose resistin contents in vivo and in vitro. These data suggest that estrogen is a pivotal negative regulator of resistin gene expression.

Adipocytes↗

PubMed2005

Diffuse soft tissue emphysema in anorexia nervosa: a case report.

OBJECTIVE: Anorexia nervosa (AN) is an eating disorder that occurs mainly among young females and its prevalence has increased in recent decades. METHODS: We reported a patient with AN with spontaneous diffuse soft tissue emphysema and bicytopenia, both of which are very rare complications of AN. Our patient, a 20-year-old woman, had lost 41.6% of her previous body weight within 9 months. Her body mass index was 10.8 and amenorrhea had persisted for 5 months. RESULTS: After admission, she was diagnosed with AN-restrictive subtype. She was noted to have crunching sounds in the neck and upper chest wall during hospitalization. A chest X-ray and chest computed tomography scan both revealed diffuse soft tissue emphysema including subcutaneous emphysema, pneumomediastinum, and pneumoretroperitoneum. DISCUSSION: Diffuse soft tissue emphysema improved gradually and completely resolved on the 21st day of hospitalization. This condition seems to be benign and only a short period of hospitalization is required.

Adult↗

PubMed2005

Short-term effect of transdermal estrogen on autonomic nervous modulation in postmenopausal women.

OBJECTIVE: To evaluate the effect of short-term transdermal estradiol-l7b on cardiac autonomic nervous modulation in postmenopausal women. DESIGN: Prospective study. SETTING: A tertiary medical center. PATIENT(S): Twenty-one postmenopausal women. INTERVENTION(S): Transdermal estradiol or placebo therapy for 3 weeks in randomized, double-blinded, crossover fashion. MAIN OUTCOME MEASURE(S): Heart rate variability measures in both time and frequency domains, serum biochemistry, and climacteric symptoms were compared among baseline, placebo and transdermal estrogen therapies. RESULT(S): Plasma concentration of estradiol rose significantly from 11.0 +/- 5.2 pg/ml to 48.2 +/- 34.0 pg/ml after transdermal estrogen. The standard deviation of RR-interval increased significantly from 30.3 +/- 9.9 ms (placebo) to 31.3 +/- 7.4 ms (transdermal estrogen), and the coefficient of variation of RR-interval increased significantly as compared with the baseline session. The total power was marginally increased as compared among baseline, placebo, and transdermal estrogen sessions. The irritability symptom decreased significantly after transdermal estrogen therapy, as compared with baseline and placebo treatment. CONCLUSION(S): Transdermal estradiol for 3 weeks could significantly increase the global heart rate variability and reduce the irritability symptom in the postmenopausal women. Short-term transdermal estrogen for 3 weeks could improve cardiac autonomic nervous modulation and climacteric symptoms, and might have some cardioprotective effect in postmenopausal women.

Administration, Cutaneous↗

PubMed2005

A longitudinal study of growth patterns in schoolchildren in one Taipei District. II: Sitting height, arm span, body mass index and skinfold thickness.

BACKGROUND: It has been suggested that longitudinal rather than cross-sectional growth standards be used to assess individual growth patterns. Thus, the aim of this study was to follow boys and girls throughout their pubertal years, so that a mixed longitudinal growth curve of height, weight, sitting height, arm span, skinfold thickness, body mass index (BMI), and the ratio of sitting height or arm span to stature, could be obtained. METHODS: A defined group of 1,139 healthy schoolchildren (570 boys and 569 girls) from the Shih-Pai district of Taipei were followed longitudinally for 4 years. Anthropometric measurements of height, weight, sitting height, arm span, skinfold thickness, and BMI, were obtained for each child. RESULTS: Peak sitting-height velocities of 6.1 cm/year (boys) and 6.3 cm/year (girls) were seen at 8.5 years. The second peak of sitting-height velocity occurred at a mean age of 12.5 years for boys and 11.5 years for girls. Sitting-height velocity for the whole year covering the second peak was 4.6 cm in boys and 3.2 cm in girls. Peak arm-span velocity was seen at 13.5 years for boys and 8.5 years for girls, and arm-span velocity for the whole year covering this peak was 8.4 cm/year for boys and 8.1 cm/year for girls. CONCLUSION: These data provide growth patterns for Chinese children aged 8-18 years living in a Taipei district, with percentile charts for sitting height, arm span, BMI, and skinfold thickness.

Adolescent↗

PubMed2005

Optimal check size and reversal rate to elicit pattern-reversal MEG responses.

OBJECTIVE: To determine the impact of check size and interstimulus interval (ISI) on neuromagnetic visual cortical responses. METHODS: We recorded visual evoked fields to pattern-reversal stimulation with central occlusion in ten subjects. The -100 ms magnetic activation (P100m) was analyzed by single dipole modeling. RESULTS: With 1 s ISI, P100m strengths increased as check size increased from 15' up to 120' of visual arc, and larger checks elicited less P100m activation. With 120' checks, we found no P100m attenuation as ISI decreased from 4 s to 0.16 s. P100m sources around the calcarine sulcus did not vary with check size or ISI. CONCLUSIONS: The magnitude of cortical activation during visual contrast processing is check size-dependent and the 120' checks are optimum for future studies on neuromagnetic visual cortical functions using central-occluded stimulation. The corresponding neuronal activation demonstrated a short refractory period less than 0.16 s. We also found significantly overlapping cortical representation areas for different check sizes or ISIs.

Adult↗

PubMed2005

Inhibitory effect of norcantharidin, a derivative compound from blister beetles, on tumor invasion and metastasis in CT26 colorectal adenocarcinoma cells.

Norcantharidin (NCTD), a potential anti-cancer drug, is the demethylated analog of cantharidin isolated from blister beetles. The present study investigated the effect of NCTD on tumor invasion and metastasis. A cytotoxicity assay of NCTD in CT26 colorectal adenocarcinoma cells showed a dose- and time-dependent decrease in cell viability. NCTD (50 microM)-treated CT26 cells not only showed an inhibited cell invasion of 65.6%, but also decreased the activity of matrix metalloproteinase-2 and -9. NCTD decreased the adhesive ability of CT26 cells in a dose-dependent manner. At a concentration of 100 microM, NCTD showed a down-expression of several cadherin-catenin adhesion molecules, including Desmoglein, N-cadherin, and alpha- and beta-catenin, while there were no obvious changes in E-cadherin and gamma-catenin. Intraperitoneal injection of NCTD (2 mg/kg/day) in BALB/c mice reduced both the pulmonary metastatic capacity of CT26 cells and prolonged the survival day of the mice. These results demonstrated that it was effective in blocking both tumor invasion and metastasis.

Adenocarcinoma↗

PubMed2004

Serum and follicular resistin levels in women with polycystic ovarian syndrome during IVF-stimulated cycles.

BACKGROUND: Resistin is a hormone linking obesity and insulin resistance. The aim of this study was to compare resistin levels in serum or follicular fluid from women with polycystic ovarian syndrome (PCOS) and controls, both of whom were undergoing IVF. METHODS: We compared serum and follicular resistin levels in 21 PCOS women and in 18 healthy, normal ovulation, age- and body mass index (BMI)-matched non-PCOS women undergoing IVF. Correlations between serum or follicular fluid resistin levels and reproductive outcome were evaluated. RESULTS: There was no significant difference in either serum or follicular resistin levels between the control group and the PCOS group as a whole or those with insulin resistance [homeostasis model assessment of insulin resistance index applied to oral glucose tolerance test (HOMA(OGTT)) <4.7]. However, resistin levels in follicular fluid were unexpectedly significantly lower than serum levels (P<0.0001) in both the PCOS and control groups. No significant correlation was found between resistin levels and BMI, estradiol, LH, or fasting or 2 h glucose or insulin levels or between follicular resistin levels and fertilization rate, implantation rate, clinical pregnancy rate, or early miscarriage rate in PCOS. CONCLUSION: Resistin is unlikely to be a major determining factor in the growth and maturation of oocytes during IVF-stimulated cycles in PCOS.

Adult↗

PubMed2004

Tree-structured supervised learning and the genetics of hypertension.

This paper is about an algorithm, FlexTree, for general supervised learning. It extends the binary tree-structured approach (Classification and Regression Trees, CART) although it differs greatly in its selection and combination of predictors. It is particularly applicable to assessing interactions: gene by gene and gene by environment as they bear on complex disease. One model for predisposition to complex disease involves many genes. Of them, most are pure noise; each of the values that is not the prevalent genotype for the minority of genes that contribute to the signal carries a "score." Scores add. Individuals with scores above an unknown threshold are predisposed to the disease. For the additive score problem and simulated data, FlexTree has cross-validated risk better than many cutting-edge technologies to which it was compared when small fractions of candidate genes carry the signal. For the model where only a precise list of aberrant genotypes is predisposing, there is not a systematic pattern of absolute superiority; however, overall, FlexTree seems better than the other technologies. We tried the algorithm on data from 563 Chinese women, 206 hypotensive, 357 hypertensive, with information on ethnicity, menopausal status, insulin-resistant status, and 21 loci. FlexTree and Logic Regression appear better than the others in terms of Bayes risk. However, the differences are not significant in the usual statistical sense.

Algorithms↗

PubMed2004

Insulin infusion induces endothelin-1-dependent hypertension in rats.

We previously showed that chronic insulin infusion induces insulin resistance, hyperendothelinemia, and hypertension in rats (C. C. Juan, V. S. Fang, C. F. Kwok, J. C. Perng, Y. C. Chou, and L. T. Ho. Metabolism 48: 465-471, 1999). Endothelin-1 (ET-1), a potent vasoconstrictor, is suggested to play an important role in maintaining vascular tone and regulating blood pressure, and insulin increases ET-1 production in vivo and in vitro. In the present study, BQ-610, a selective endothelin A receptor antagonist, was used to examine the role of ET-1 in insulin-induced hypertension in rats. BQ-610 (0.7 mg/ml; 0.5 ml/kg body wt) or normal saline was given intraperitoneally two times daily for 25 days to groups of rats infused with either saline or insulin (2 U/day via sc-implanted osmotic pumps), and changes in plasma levels of insulin, glucose, and ET-1 and the systolic blood pressure were measured over the experimental period, whereas changes in insulin sensitivity were examined at the end of the experimental period. Plasma insulin and ET-1 levels were measured by RIA, plasma glucose levels using a glucose analyzer, systolic blood pressure by the tail-cuff method, and insulin sensitivity by an oral glucose tolerance test. Our studies showed that insulin infusion caused sustained hyperinsulinemia in both saline- and BQ-610-injected rats over the infusion period. After pump implantation (2 wk), the systolic blood pressure was significantly higher in insulin-infused rats than in saline-infused rats in the saline-injected group (133 +/- 3.1 vs. 113 +/- 1.1 mmHg, P < 0.05) but not in the BQ-610-injected group (117 +/- 1.2 vs. 117 +/- 1.8 mmHg). Plasma ET-1 levels in both sets of insulin-infused rats were higher than in saline-infused controls (2.5 +/- 0.6 and 2.5 +/- 0.8 vs. 1.8 +/- 0.4 and 1.7 +/- 0.3 pmol/l, P < 0.05). Oral glucose tolerance tests showed that BQ-610 treatment did not prevent the insulin resistance caused by chronic insulin infusion. No significant changes were found in insulin sensitivity and blood pressure in saline-infused rats treated with BQ-610. In a separate experiment, insulin infusion induced the increase in arterial ET-1 content, hypertension, and subsequent plasma ET-1 elevation in rats. These results suggest that, in the insulin infusion rat model, ET-1 plays a mediating role in the development of hypertension, but not of insulin resistance.

Animals↗

PubMed2004

Effect of green tea supplementation on insulin sensitivity in Sprague-Dawley rats.

Epidemiological observations and laboratory studies have shown that green tea has a variety of health effects, including antitumor, antioxidative, and hypolipidemic activities. The aim of this study was to examine whether it had an effect on glucose tolerance and insulin sensitivity in Sprague-Dawley rats. In experiment 1 (in vivo study), rats were divided into two groups: a control group fed standard chow and deionized distilled water and a "green tea" group fed the same chow diet but with green tea instead of water (0.5 g of lyophilized green tea powder dissolved in 100 mL of deionized distilled water). After 12 weeks of green tea supplementation, the green tea group had lower fasting plasma levels of glucose, insulin, triglyceride, and free fatty acid than the control rats. Insulin-stimulated glucose uptake of, and insulin binding to, adipocytes were significantly increased in the green tea group. In experiment 2 (in vitro study), a tea polyphenol extract was used to determine its effect on insulin activity in vitro. Green tea polyphenols (0.075%) significantly increased basal and insulin-stimulated glucose uptake of adipocytes. Results demonstrated that green tea increases insulin sensitivity in Sprague-Dawley rats and that green tea polyphenol is one of the active components.

Adipocytes↗

PubMed2004

Green tea supplementation ameliorates insulin resistance and increases glucose transporter IV content in a fructose-fed rat model.

BACKGROUND: Sprague-Dawley rats fed a fructose-rich diet exhibit insulin resistance and hypertension, a pathologic status resembling human type II diabetes mellitus, and are an excellent laboratory animal model for research on insulin action and the development of hypertension. Since green tea has numerous beneficial effects, we tested its effect on fructose-fed rats. AIM: The present study was therefore designed to further evaluate the effects of green tea supplementation on insulin resistance, hypertension, and the glucose transporters I and IV contents in adipose tissue in the fructose-fed rat model. METHODS: The animals were divided into three groups and fed for 12 weeks with standard chow and water (control group), a high fructose diet and water (fructose group), or the same high fructose diet, but with green tea (0.5 g of lyophilized green tea powder dissolved in 100 mL of deionized distilled water) instead of water (fructose/green tea group). During the 12 weeks study period, fresh water or green tea was provided daily at 6:00 PM. Blood pressure was measured twice a week, and an oral glucose tolerance test performed after 12 weeks of diet supplementation. At the end of the experiment, plasma triglyceride (TG), free fatty acid (FFA), glucose, and insulin were assayed. The epididymal fat pads from all rats in the same group were pooled and adipocytes isolated and tested for insulin binding, glucose uptake, and their content of glucose transporters I (GLUT I) and IV (GLUT IV). RESULT: Compared to the control group, the fructose group developed fasting hyperglycemia, hyperinsulinemia, and elevated blood pressure. Insulin-stimulated glucose uptake and insulin binding of adipocytes were significantly reduced, and the glucose transporter IV content of adipocytes also decreased. The fructose/green tea group showed improvement in all of these metabolic defects and in insulin resistance and blood pressure. CONCLUSION: Based on these results, we suggest that the amelioration of insulin resistance by green tea is associated with the increased expression of GLUT IV.

Adipose Tissue↗

PubMed2004

Orthographic and phonological processing of Chinese characters: an fMRI study.

The present study used functional magnetic resonance imaging (fMRI) to investigate the neural mechanisms underlying the orthographic and phonological processing of Chinese characters. Four tasks were devised, including one homophone judgment and three physical judgments of characters, pseudo-characters, and Korean-like nonsense figures. While the left occipitotemporal region, left dorsal processing stream, and right middle frontal gyrus constitute a network for orthographic processing, the left premotor gyrus, left middle/inferior frontal gyrus, supplementary motor area (SMA), and the left temporoparietal region work in concert for phonological processing. The ventral part of the left inferior frontal cortex responds specifically to the character stimuli, suggesting a general lexical processing role for this region for linguistic material. The stronger activation of the dorsal visual stream by Chinese homophone judgment pinpoints a tight coupling between phonological representation of Chinese characters and corresponding orthographic percepts. The concomitant engagement of sets of regions for different levels of Chinese orthographic and phonological processing is consistent with the notion of distributed parallel processing.

Adult↗