Emiko Suzuki

Green tea catechins prevent low-density lipoprotein oxidation via their accumulation in low-density lipoprotein particles in humans

Green tea is rich in polyphenols, including catechins which have antioxidant activities and are considered to have beneficial effects on cardiovascular health. In the present study, we investigated the effects of green tea catechins on low-density lipoprotein (LDL) oxidation in vitro and in human studies to test the hypothesis that catechins are incorporated into LDL particles and exert antioxidant properties. In a randomized, placebo-controlled, double-blind, crossover trial, 19 healthy men ingested green tea extract (GTE) in the form of capsules at a dose of 1 g total catechin, of which most (>99%) was the gallated type. At 1 hour after ingestion, marked increases of the plasma concentrations of (-)-epigallocatechin gallate and (-)-epicatechin gallate were observed. Accordingly, the plasma total antioxidant capacity was increased, and the LDL oxidizability was significantly reduced by the ingestion of GTE. We found that gallated catechins were incorporated into LDL particles in nonconjugated forms after the incubation of GTE with plasma in vitro. Moreover, the catechin-incorporated LDL was highly resistant to radical-induced oxidation in vitro. An additional human study with 5 healthy women confirmed that GTE intake sufficiently increased the concentration of gallated catechins, mainly in nonconjugated forms in LDL particles, and reduced the oxidizability of LDL. In conclusion, green tea catechins are rapidly incorporated into LDL particles and play a role in reducing LDL oxidation in humans, which suggests that taking green tea catechins is effective in reducing atherosclerosis risk associated with oxidative stress.

Risk Imparted by Various Parameters of Smoking in Japanese Men With Type 2 Diabetes on Their Development of Microalbuminuria Analysis from the Tsukuba Kawai Diabetes Registry

Whether smoking is an independent risk factor for the development of microalbuminuria has yet to be established. Inconsistencies in previous studies (1–12) might have been due to inadequacies in assessing smoking status of patients (i.e., current, ex-, or never) (13). Moreover, although detailed quantitative assessment is critical for evaluating smoking risks (14), the dose effect of smoking on the development of nephropathy is not known (13). Therefore, we examined a wide variety of smoking parameters to clarify their relationship to microalbuminuria in a cohort of Japanese patients with type 2 diabetes. Data were derived from the ongoing Tsukuba Kawai Diabetes Registry database of the Kawai Clinic, which began collecting patient information in 1995. The Kawai Clinic is a typical diabetes clinic located in a suburb of Tokyo. All type 2 diabetic patients were consecutively registered for this study at their first visit. Study protocol was consistent with the Japanese Governments Ethical Guidelines Regarding Epidemiological Studies in accordance with the Declaration of Helsinki. Data from 357 normoalbuminuric male patients with type 2 diabetes (diagnosed according to the World Health Organization criteria [14]) who had been followed for at least 3 years were analyzed. No data from female patients were included because their smoking frequency was quite low (9.4%). Patients were said to be normoalbuminuric if …

Are serum cholesterol levels associated with silent brain infarcts? The Seiryo Clinic Study

OBJECTIVE High levels of serum cholesterol are associated with the risk of stroke. However, the association of serum cholesterol with silent brain infarcts (SBIs) is unclear. We investigated the association between SBI and various clinical factors. METHODS We conducted a cross-sectional study that included 324 apparently healthy Japanese men (mean age 53.8+/-9.2 years). Combinations of three types of scan (T1-weighted, T2-weighted and FLAIR images) were used to detect and discriminate SBI. RESULTS Serum cholesterol was significantly associated with SBI [total cholesterol, odds ratio (OR) 3.75 (95% confidence interval (CI) 1.45-9.68); LDL-cholesterol, OR 2.54 (95% CI 1.03-6.27), and non-HDL-cholesterol, OR 2.54 (95% CI 1.03-6.27)] after adjustment for age, smoking status, serum triglycerides, maximal-intima-media thickness, obesity, hypertension, diabetes mellitus, hyperuricemia, coronary heart disease and lipid-lowering agent use. CONCLUSION Our cross-sectional data suggest that serum cholesterol levels are associated with SBI independently of known confounders.

Branched chain amino acids as source of specific branched chain volatile fatty acids during the fermentation process of fish sauce.

Summary. The source of the formation of branched chain volatile fatty acids (VFA) in fish sauce was investigated. Certain branched VFA were derived from the degradation of specific amino acids as iso-butyric acid from valine and iso-valeric acid from leucine. Short and long straight chain VFA were significantly higher in the linoleic acid added sample than in the control but did not significantly bring changes to the branched chain VFA. It is suggested that straight chain VFA developed from fish fats. Alanine and isoleucine did not have a clear influence on the production of volatile fatty acids.

Effect of streptozotocin-induced diabetes on rat liver mRNA level of antioxidant enzymes

Wistar rats were injected with streptzotocine. Total mRNA was prepared by ultracentrifuge from the liver, and cDNA was synthesized by reverse transcriptase. The mRNA of l-gulonolactone oxidase, catalase and glutathione peroxidase (Gpx) were decreased significantly (p<0.05) measured by competitive reverse transcription-polymerase chain reaction (RT-PCR). The mRNA of plasma alpha 1 proteinase inhibitor 3 was also strongly decreased. CuZn-superoxide dismutase (SOD) mRNA was decreased slightly.

Vitamin C impacts anxiety-like behavior and stress-induced anorexia relative to social environment in SMP30/GNL knockout mice

The role of endogenous vitamin C (VC) in emotion and psychiatric measures has long been uncertain. We aimed to investigate how an individuals VC status impacts his or her mental health. Our hypothesis is that body VC levels modulate anxiety, anorexia, and depressive phenotypes under the influence of psychosocial rearing environments and sex. The VC status of senescence marker protein-30/gluconolactonase knockout mice, which lack the ability to synthesize VC, were continuously shifted from adequate (VC+) to depleted (VC-) by providing a water with or without VC. Despite weight loss in both sexes, suppressed feeding was specifically seen in males only during the VC- phase. Anxiety responses in the novelty-suppressed feeding paradigm were worse during the VC-, especially in females. Sensitivity to the forced swim test as determined by the initial latency was significantly shorter in the socially stable animals compared with socially unstable animals during the VC+ condition. The stress coping underlying depressive phenotypes was assessed by immobility duration in a series of forced swim tests. No significant differences were apparent between contrasting VC status. Homeostatic symptoms following stressful behavioral tests consisted of a great loss of appetite during the VC-. It should be noted that anorexia is extremely serious for the females. We conclude that endogenous VC status is critical for determining vulnerability to anxiety and anorexia in a sex-specific manner.

Characterization of beta-tricalcium phosphate as a novel immunomodulator

Calcium phosphate (CaP) ceramics including hydroxyapatite (HA) and beta-tricalcium phosphate (β-TCP) have been widely used for bone substitution in orthopedic, maxillofacial and dental surgery, as well as in tumor resections. CaP particles are also known to cause inflammatory responses, which are thought to be an unfavorable characteristic of prosthetic coating materials. On the other hand, the immunostimulatory effect of β-TCP induces an anti-tumor effect in xenograft tumor models in athymic mice. To date, in depth analysis of the biological effects of β-TCP has not been studied in mice. In the present study, in vivo biological effects of β-TCP were investigated by subcutaneously injecting β-TCP particles into mice. This induced extensive migration of immune cells to the area surrounding the injection. In addition, we found that in vitro treatment with β-TCP in murine monocyte/macrophage cells (J774A.1) induced up-regulation of surface expression of CD86, and increased production of TNF-α, MIP-1α, and sICAM-1. Furthermore, conditioned medium from J774A.1 cells treated with β-TCP facilitated migration of murine splenocytes in a transwell migration assay. These findings clarify that β-TCP induces an immunostimulatory effect in mice, and suggest a potential for β-TCP as a novel adjuvant for cancer therapy.

Formation of Volatile Acids During Fermentation of Fish Sauce

Fish sauce is a clear brown liquid, hydrolysis product of salted fish and possesses a characteristics odor. It is one of the most popular fermented fish products in Southeast Asia and is known by various names according to the country of origin 
for example, Patis in the Philippines※ Nampla in Thailand※ Ngampi‐pya‐ye in Burma or presently Myanmar※ Shottsuru in Japan※ Ketjap‐ikan in Indonesia※ or Nuocman in Vietnam . It is generally used as condiment, but it is also an important source of protein in the diets of some social classes and in specific areas in the region. Lafont
1955 reported that fish sauces should be considered as a condiments only. Those with 1‥ nitrogen or more could be considered as rather better than condiments. Fish sauces contain 20 g/L of nitrogen, of which 16 g/L are in the form of amino acids.

Effects of beta-tricalcium phosphate particles on primary cultured murine dendritic cells and macrophages

Beta-tricalcium phosphate (β-TCP) is widely used for bone substitution in clinical practice. Particles of calcium phosphate ceramics including β-TCP act as an inflammation mediators, which is an unfavorable characteristic for a bone substituent or a prosthetic coating material. It is thought that the stimulatory effect of β-TCP on the immune system could be utilized as an immunomodulator. Here, in vitro effects of β-TCP on primary cultured murine dendritic cells (DCs) and macrophages were investigated. β-TCP particles enhanced expression of costimulatory surface molecules, including CD86, CD80, and CD40 in DCs, CD86 in macrophages, and MHC class II and class I molecules in DCs. DEC205 and CCR7 were up-regulated in β-TCP-treated DCs. Production of cytokines and chemokines, including CCL2, CCL3, CXCL2, and M-CSF, significantly increased in DCs; CCL2, CCL3, CCL4, CCL5, CXCL2, and IL-11ra were up-regulated in macrophages. The results of the functional assays revealed that β-TCP caused a prominent reduction in antigen uptake by DCs, and that conditioned medium from DCs treated with β-TCP facilitated the migration of splenocytes in the transwell migration assay. Thus, β-TCP induced phenotypical and functional maturation/activation of DCs and macrophages; these stimulating effects may contribute to the observed in vivo effect where β-TCP induced extensive migration of immune cells. When compared to lipopolysaccharide (LPS), an authentic TLR ligand, the stimulatory effect of β-TCP on the immune systems is mild to moderate; however, it may have some advantages as a novel immunomodulator. This is the first report on the direct in vitro effects of β-TCP against bone marrow-derived DCs and macrophages.

The Level of Orally Ingested Vitamin C Affected the Expression of Vitamin C Transporters and Vitamin C Accumulation in the Livers of ODS Rats

We investigated the effects of vitamin C administration on vitamin C-specific transporters in ODS/ShiJcl-od/od rat livers. The vitamin C-specific transporter levels increased in the livers of the rats not administered vitamin C and decreased in the livers of those administered vitamin C at 100 mg/d, indicating that these transporter levels can be influenced by the amount of vitamin C administered.