Biomedical subjects

Sachiko Takahashi

Publications and source records attributed to Sachiko Takahashi.

7 recordsLinked to original sources

PubMed2005

Iminosugar-producing Thai medicinal plants.

Alpha-1-C-hydroxymethylfagomine (7), 3-O-beta-D-glucopyranosyl-DMDP (12), and 2,5-dideoxy-2,5-imino-D-glucitol (13) were isolated from the Thai traditional crude drug "Non tai yak" (Stemona tuberosa), which also contains a high concentration level of alpha-homonojirimycin (0.1% dry weight). "Thopthaep" (Connarus ferrugineus) and "Cha em thai" (Albizia myriophylla) contained 1-deoxymannojirimycin (DMJ) (10) at levels of 0.083% (dry weight) and 0.17% (dry weight), respectively. 2-O-alpha-D-Galactopyranosyl-DMJ (20), 3-O-beta-D-glucopyranosyl-DMJ (21), 1,4-dideoxymannojirimycin (17), 1,4-dideoxyallonojirimycin (18), and 1,4-dideoxyaltronojirimycin (19) from C. ferrugineus and 2-O-beta-D-glucopyranosyl-DMJ (22) and 4-O-beta-D-glucopyranosyl-DMJ (23) from A. myriophylla were isolated as new compounds.

Alkaloids↗

PubMed2005

Effect of formaldehyde gas exposure in a murine allergic contact hypersensitivity model.

To clarify the effect of formaldehyde (FA) gas exposure on contact hypersensitivity (CHS), CHS reactions against 2,4,6-trinitrochlorobenzene (TNCB) was studied in BALB/c mice with a low dose of FA gas exposure. The TNCB-induced CHS reactions were slightly suppressed by the FA gas exposure immediately after sensitization, whereas they were significantly enhanced and prolonged in mice continuously exposed to FA gas before and after sensitization. We showed that exposure to FA gas enhanced the Th2 dominant responses in draining lymph node (LN) in early stage of CHS. In contrast, T cell subsets and their intracellular cytokine production in the draining LN were similar during the early stage of CHS by FA gas exposure during the sensitization phase. The percentage of CD8+ T cells was increased, and the percentage of CD4+CD25+ T cells was decreased in the FA gas-exposed group at 72 hr after elicitation. These results indicate that FA gas-exposed might influence regulatory T cells. Furthermore, in the chronic CHS model that was repetitively elicited with TNCB, more intensive and prolonged CHS reactions, and increased numbers of mast cells were found in the FA gas-exposed group at 4 hr after elicitation than in the control group, FA gas exposure may alter the intensity of allergic CHS.

Administration, Cutaneous↗

PubMed2005

[A case of chronic renal failure complicated with tuberculous meningitis successfully diagnosed by nested polymerase chain reaction (PCR)].

A 44 year-old woman was diagnosed as having chronic renal failure due to rapidly progressive glomerulonephritis (RPGN) from one year earlier. She has been managed with steroid therapy and hemodialysis. The patient was admitted to our hospital because of fever and sudden disturbance of consciousness with generalized convulsion on October 30, 2003. She showed mild meningeal irritation. Cerebrospinal fluid (CSF) examination demonstrated a cell count of 60/microl, protein level of 70 mg/dl, glucose level of 52 mg/dl, and chloride (Cl) level of 116 mEq/l. Both the CSF culture for Mycobacterium (M.) tuberculosis and the conventional single polymerase chain reaction (PCR) for M. tuberculosis DNA in CSF were negative results on admission. In contrast, nested PCR of preserved CSF samples obtained at admission demonstrated positive results. We diagnosed her conditions as tuberculous meningitis (TBM) and administered a total of 3 anti-tuberculosis agents over a period of about 2 months. Her clinical condition and CSF examinations improved immediately in response to anti-tuberculosis treatment. Serial CSF cultures for M. tuberculosis and the serial single PCRs for M. tuberculosis DNA in CSF were all negative during the course of anti-tuberculosis treatment. However, serial nested PCR results gradually converted from positive to negative, correlating with the improvement in clinical conditions during the course of anti-tuberculosis treatment. Therefore, nested PCRs were much more useful for the rapid and accurate diagnosis of TBM and for assessment of the clinical course and anti-tuberculosis treatment response of TBM than conventional CSF cultures and single PCRs. To the best of our knowledge, there have been few previous reports of diachronic study in which the serial nested PCR was used to test CSF samples obtained earlier in the clinical course of TBM. In conclusion, our findings suggest that nested PCR for M. tuberculosis DNA in CSF was highly useful not only for rapid and accurate diagnosis of TBM, but also for assessment of the antituberculous treatment response in cases highly suspected of TBM despite negative results on conventional cultures and single PCRs.

Adult↗

PubMed2005

Distribution of Chlamydia trachomatis serovars among female prostitutes and non-prostitutes in Thailand, and non-prostitutes in Japan during the mid-90s.

The distribution of Chlamydia trachomatis serovars in Thailand and Japan during the same period of the mid-90s was determined. Seventy-one C . trachomatis specimens isolated from female patients who visited the Venereal Diseases Center at Bangkok, Thailand in 1994 were used in this study. Of these, 56 patients were prostitutes. Forty-seven specimens obtained from female non-prostitutes who attended the Department of Obstetrics and Gynecology, Saitama Medical School, Japan during the period from 1993 to 1995 were also used in this study. DNA was extracted from these specimens and typing of C. trachomatis serovars was performed by the polymerase chain reaction-restriction fragment length polymorphism method. The identified serovars among prostitutes of Thailand (n = 56)/non-prostitutes of Thailand (n = 15)/non-prostitutes of Japan (n = 47) were as follows: Ba 1/0/2, D 8/1/15, E 11/2/8, F 16/9/8, G 4/0/7, H 3/2/3, I 1/0/1, J 3/0/0, and K 10/1/4. Serovar F was most prevalent (35.2%) in both prostitutes and non-prostitutes from Thailand, followed by serovar E (18.3%). On the other hand, serovar D was the most frequent serovar in non-prostitutes in Japan (31.9%) followed by serovars F (17.0%) and E (17.0%). A difference in the distribution of C. trachomatis serovars of Thailand and Japan was noted.

Adolescent↗

PubMed2004

Numerical analysis of the depletion zone formation around a growing protein crystal.

It is expected that a protein depletion zone and an impurity depletion zone are formed around a crystal during protein crystal growth if the diffusion field around the crystal is not disturbed. The growth rate of the crystal may be decreased and the impurity uptake may be suppressed to result in highly ordered crystals if these zones are not disturbed. It is well known that a microgravity environment can reduce convective fluid motion, and this is thought to disturb the depletion zones. Therefore, we expect that crystals grown in space can attain better quality than those grown on the ground. In this study, we estimate the depletion zone formation numerically and discuss the results of crystallization in space experiments. In case of alpha-amylase, most of the crystals form a cluster-like morphology on the ground using PEG 8000 as a precipitant. However, in space, we have obtained a single and high-quality crystal grown from the same sample compositions. We have measured the viscosity of the solution, the diffusion coefficient, and the growth rate of protein crystals on the ground. Applying numerical analysis to these values a significant depletion zone was expected to form mainly due to higher values of the viscosity. This might be one of the main reasons for better quality single crystals grown in space, where the depletion zone is thought to remain undisturbed. For protein crystallization experiments, salts are widely used as a precipitant. However, in that case, reduced concentration depletion zone effects can be expected because of a low viscosity. Therefore, if it is possible to increase the viscosity of the protein solution by means of an additive, the depletion zone formation effect would be enhanced to provide a technique that would be especially effective in space.

Aspergillus oryzae↗

PubMed2003

A simplified counter diffusion method combined with a 1D simulation program for optimizing crystallization conditions.

We developed a new protein crystallization method has been developed using a simplified counter-diffusion method for optimizing crystallization condition. It is composed of only a single capillary, the gel in the silicon tube and the screw-top test tube, which are readily available in the laboratory. The one capillary can continuously scan a wide range of crystallization conditions (combination of the concentrations of the precipitant and the protein) unless crystallization occurs, which means that it corresponds to many drops in the vapor-diffusion method. The amount of the precipitant and the protein solutions can be much less than in conventional methods. In this study, lysozyme and alpha-amylase were used as model proteins for demonstrating the efficiency of this method. In addition, one-dimensional (1-D) simulations of the crystal growth were performed based on the 1-D diffusion model. The optimized conditions can be applied to the initial crystallization conditions for both other counter-diffusion methods with the Granada Crystallization Box (GCB) and for the vapor-diffusion method after some modification.

Capillary Action↗

PubMed2003

Clinical utility and approach to estimate postprandial hypertriglycemia by a newly designed oral fat-loading test.

The objective of this study was to estimate postprandial hypertriglycemia by a newly designed oral fat-loading test. Twenty-three healthy normolipidemic volunteers were orally administered a test meal consisting of a mixture of Telmeal 2.0 and 20 g of salt-free butter after fasting for 12 h. To measure the levels of total cholesterol (T-Cho), triglycerides (TG), high-density lipoprotein-cholesterol (HDL-C), remnant-like particle-cholesterol (RLP-C), lipoprotein (a) [Lp (a)], free fatty acid, apolipoproteins (Apos), plasma glucose (PG), immunoreactive insulin (IRI), and high-sensitivity C-reactive protein (hs-CRP), venous blood samples were collected before the meal and at each hour until 9 h after fat-loading. The levels of both TG and RLP-C were drastically elevated at 2 h after fat-loading and these levels remained high until 4 h (p < 0.01). A significant correlation between TG and RLP-C was also observed at 2, 3 and 4 h, and the values of the correlation coefficients (r) were 0.837, 0.838, and 0.908, respectively. In contrast, the levels of T-Cho, HDL-C, Lp (a), Apos, PG, and hs-CRP did not change. Furthermore, there were no gastrointestinal symptoms during or after the study. These results strongly suggested that this newly designed fat-loading test was very useful for evaluating postprandial hypertriglycemia, including remnant concentrations.

Adult↗