Biomedical subjects

T Takagi

Publications and source records attributed to T Takagi.

1,095 records · Page 61Linked to original sources

PubMedDate not supplied

Gas chromatographic resolution of polyunsaturated wax esters based on their degree of unsaturation on Silar 10C.

Wax esters of C28-C44 chain-lengths, and containing 0-7 double bonds, were characterized with equivalent chain lengths [ECL] obtained by GC using a cyanosiloxane, Silar 10C. The ECL of the unsaturated wax esters is significantly dependent upon the column temperature, and selection of an appropriate column temperature permitted adequate resolution of critical pairs differing in the degree of unsaturation or the position of the double bonds.

Animals↗

PubMedDate not supplied

Development of an implantable artificial anal sphincter by the use of the shape memory alloy.

In this study, we developed and assessed an artificial anal sphincter driven by an shape memory alloy actuator (AS-SMA). The performance characteristics of the device were analyzed with a measurement system. Assessment showed that the AS-SMA could generate a pressure of 55 mm Hg at an atmospheric temperature of 36 degrees C, and displacement of the SMA actuator was 7.5 mm when the temperature of the SMA plate was 55 degrees C. To evaluate opening and closing, we studied a piglet colostomy model, in which the AS-SMA was implanted around the colostomy in the extraperitoneal space. Flow control tests using living porcine intestine revealed that the AS-SMA could maintain fecal continence against an intestinal pressure of 75 mm Hg. The high pressure zone corresponding to the location of the device was demonstrated in a manometric examination. For 6 days after surgery, we activated the AS-SMA twice a day and observed the bowel movements. The animal experiment indicated that the AS-SMA is able to control the bowel movements of patients with fecal incontinence if several problems, such as burning of tissue around the device and compression injury of the intestine, are resolved.

Alloys↗

PubMedDate not supplied

gamma-Glutamyl transpeptidase activity in liver of alcoholics and its localization.

The activity and the histochemical localization of gamma-GTP in the liver of chronic alcoholics were investigated. Mean serum gamma-GTP activity in alcoholics was 542.5 +/- 337.9 milliunits/ml, and that of patients with nonalcoholic liver disease was 34.3 +/- 22.6 milliunits/ml. Hepatic gamma-GTP activity in alcoholics was significantly increased compared to that in control patients (15.62 +/- 9.29 versus 4.04 +/- 2.67 units/g of liver; p less than 0.001). A significant correlation was observed between hepatic and serum gamma-GTP activity. Light microscopically, a marked gamma-GTP activity was found in the bile canaliculi and a diffuse activity in the cytoplasm in alcoholic livers. By contrast, in the livers of nonalcoholic patients, only slight activity was observed in the bile canaliculi. The electron micrographs showed the enzyme was localized in the microvilli of both the bile canalicular and plasma membranes and the endoplasmic reticulum near the mitochondria in alcoholics. But a very low activity was demonstrated in the plasma membranes in the livers of nonalcoholic patients.

Bile Canaliculi↗

PubMedDate not supplied

Efficacy of maternal serum screening in the prenatal detection of fetal chromosome abnormalities in Japanese women.

OBJECTIVE: This prospective study assesses the efficacy of maternal serum screening for use in prenatal diagnosis of fetal anomaly and chromosome imbalance in Japanese women. METHODS: Maternal serum alpha-fetoprotein, human chorionic gonadotropin, and unconjugated estriol were measured in 1,055 singleton pregnant women between 14 and 20 weeks of gestation. A calculated risk for trisomy 21 of >/=1/299 or alpha-fetoprotein >/=2.5 multiples of the median was adopted as positive. RESULTS: Three hundred and seventy-eight of the 1, 055 women screened (35.8%) were identified as positive. Sensitivity, false-positive rate, and positive predictive value in women aged <35 years were 60.0, 10.6, and 6.8%, respectively, and these values were 87.5, 49.3, and 4.2%, respectively, in women aged >/=35 years. The false-positive rate in women aged <35 years was significantly lower than that for women aged >/=35 years (p < 0.001). Chromosomal abnormalities were identified in 21 cases, including 10 with trisomy 21, 5 with trisomy 18, 2 with trisomy 13, and 4 with other chromosomal disorders. Seventeen of the 21 cases (81.0%) showed screen-positive results, and among these all 10 cases with trisomy 21 were detectable. Two cases with trisomy 18, 1 with trisomy 13 and 1 with isochromosome X showed extremely low human chorionic gonadotropin levels (0.4 +/- 0.1 multiples of the median, mean +/- SE), although they were screen negative. Of the 264 women who did not undergo amniocentesis, none had any clinical findings consistent with aneuploidy after birth. CONCLUSIONS: Our results suggest that the evaluation of each serum marker, as well as of the calculated risk, was significantly important in the prenatal detection of fetal aneuploidy.

Adult↗

PubMedDate not supplied

Telomerase activity and expression of telomerase RNA component and catalytic subunits in precancerous and cancerous colorectal lesions.

To investigate the role of telomerase activity in colorectal adenoma-carcinomas, telomerase activity, human telomerase RNA component (hTERC) and human telomerase reverse transcriptase (hTERT) mRNA were quantitatively analyzed in human cancerous and precancerous colorectal tissues. Sixty-six colorectal tumor specimens, including 10 invasive carcinomas, 6 mucosal carcinomas and 50 adenomas were evaluated. Ten specimens of normal tissue were also included in the study. Telomerase activity was assayed by semiquantitative fluorescence using the TRAP-eze(TM) telomerase detection kit. Analysis of the expression of each telomerase subunit gene was performed by real-time PCR amplification. There was a positive correlation between histological atypia and telomerase activity (rho = 0.700, p < 0.0001), hTERT mRNA expression (rho = 0.603, p < 0.0001), and hTERC expression (rho = 0.290, p < 0.05). There was also a positive correlation between the levels of hTERT mRNA and telomerase activity (r = 0.455, p < 0.01). Significant differences in the levels of hTERT mRNA were shown between normal tissues and the adenomas (p < 0.05) and between the mucosal carcinomas and invasive carcinomas (p < 0.05). The values of hTERC expression in neoplastic tissues were significantly higher than in the normal tissues; however, there were no significant differences between the adenomas and the carcinomas. In summary, although upregulation of hTERC expression is an early event in adenoma development, hTERT mRNA expression is gradually upregulated during the adenoma-carcinoma sequence and may be a rate-limiting determinant of telomerase activity.

Adenocarcinoma, Mucinous↗

PubMedDate not supplied

Effect of nimodipine on cerebral functional and metabolic recovery following ischemia in the rat brain.

Whether the calcium entry blocker, nimodipine, prevents the increase in the concentration of free fatty acids and metabolic disturbances during ischemia and promotes functional and metabolic recovery after recirculation were examined. Severe forebrain ischemia in rats was induced by four-vessel occlusion with mild hypotension. After 30 minutes of ischemia, recirculation was started by removal of the arterial clamps and by increasing blood pressure to the preischemic level. Recovery of EEG activity following recirculation was better in the nimodipine-treated group than in the control group. During the ischemic period, there were no significant differences in accumulation of free fatty acids or in depletion of ATP between treated and control groups. At 120 minutes following recirculation, recovery of the ATP level was significantly better in the treated group than in the control group. Therefore, the promotion of functional and metabolic recovery by nimodipine-treatment is suggested to be not due to the prevention of an accumulation of free fatty acids nor to the depletion of ATP during the ischemic period, but to either improvement of postischemic hypoperfusion or a direct action on metabolic processes during reperfusion period.

Adenosine Triphosphate↗

PubMedDate not supplied

Bcl-2 related proteins are dramatically induced at the early stage of differentiation in human liver cancer cells by a histone deacetylase inhibitor projecting an anti-apoptotic role during this period.

Expression of the Bcl-2 family members in a human hepatocellular carcinoma cell line (HCC-T) after sodium butyrate-treatment was investigated. Sodium butyrate, a histone deacetylase inhibitor, induced differentiation of the cell line into its normal counterpart without inducing apoptosis at the concentration of 2 mmol/l. Since sodium butyrate has effects on both differentiation and apoptosis, we investigated the expression profile of bcl-2 related genes in HCC-T. The expression of Bcl-2 and Mcl-1/EAT was up-regulated 4-12 h after the treatment while Bcl-XL was up-regulated 2-3 days after the stimulation. On the other hand, the expression levels of Bax protein remained unchanged during differentiation. The HCC-T cells entered a cell cycle arrest at G1 and showed neither cellular fragmentation nor apoptosis during this period, which was concomitantly associated with up-regulated expression of a cell cycle regulator, p21WAF-1. These results demonstrate that induction of anti-apoptotic bcl-2 related proteins at an early stage of differentiation is important for the maintenance of HCC-T cell differentiation by antagonizing pro-apoptotic molecules such as Bax.

Apoptosis↗

PubMedDate not supplied

CD44 expression on chondrocytes in knees of DBA/1 mice with type II collagen-induced arthritis.

OBJECTIVE: To investigate aspects of CD44 expression in the cartilage destruction of the knees of mice with collagen-induced arthritis. METHODS: DBA/1 mice were immunized with bovine type II collagen emulsified with Freund's incomplete adjuvant. Histological changes in the knees were evaluated in sections stained with hematoxylin and eosin, toluidine blue, and immunostaining using anti-CD44 monoclonal antibodies. RESULTS: CD44 expression was observed in the synovial lining and articular chondrocytes. A total of 10/10 knees had CD44-positive synovial lining cells at 6 weeks after immunization, which was higher than that at 4 weeks (7 of 10 knees, p < 0.05). At 4 weeks 3 of 10 knees with CD44-positive chondrocytes were observed, and 7 of 10 knees at 6 weeks after immunization. The number of knees at 6 weeks was higher than that at 4 weeks (p < 0.01). Nine of 10 knees showed loss of metachromasia on toluidine blue staining at 6 weeks after immunization, which was higher than the number at 4 weeks. The grade of metachromasia loss and the length of time after immunization were significantly correlated (p < 0.05, Spearman rank correlation; p = 0.46). CONCLUSION: These findings suggest that CD44 may play some role in the early stage of cartilage destruction in DBA/1 mice immunized with type II collagen.

Animals↗

PubMedDate not supplied

NF-kappa B and I-kappa B overexpression in articular chondrocytes with progression of type II collagen-induced arthritis in DBA/1 mouse knees.

OBJECTIVE: To investigate the roles of NF-kappa B and I-kappa B in chondrocytes in the cartilage destruction of mouse collagen-induced arthritis. METHODS: DBA/1 mice were immunized with bovine type II collagen (C II) emulsified with Freund's incomplete adjuvant. Histological abnormalities in the mouse knees were evaluated in sections stained with hematoxylin and eosin, or toluidine blue. Immunostaining using anti-NF-kappa B and anti-I-kappa B antibodies was performed to observe the expression and nuclear shift of NF-kappa B and I-kappa B in articular chondrocytes. RESULTS: Loss of metachromasia of perichondrial cartilage was found in 8 out of 10 knees of the mice at 5 weeks, and in all 10 knees at 7 weeks after C II-immunization. The mean percentage of NF-kappa B-positive chondrocytes at 3, 5 and 7 weeks and in the control was 33.6 +/- 7.6, 54.9 +/- 2.7, 75.9 +/- 1.0 and 27.9 +/- 3.8%, respectively. The mean percentage of NF-kappa B-positive nuclei was 9.1 +/- 0.7, 19.5 +/- 3.7, 47.5 +/- 3.0 and 8.6 +/- 0.1%, respectively. NF-kappa B-positive chondrocytes significantly increased from 3 to 7 weeks in a time-dependent manner (p < 0.0001). The percentage of I-kappa B-positive chondrocytes at 3, 5 and 7 weeks and in the control was 15.5 +/- 1.7, 41.1 +/- 2.5, 51.2 +/- 5.7 and 12.1 +/- 2.1%, respectively. I-kappa B-positive chondrocytes significantly increased from 3 to 5 weeks (p < 0.005). CONCLUSION: These findings suggest that nuclear shift of NF-kappa B localization causes cartilage destruction in the early stage of arthritis in DBA/1 mice immunized with C II.

Animals↗

PubMedDate not supplied

[Usefulness and limitations of dobutamine stress echocardiography for detection of coronary artery disease].

The value of dobutamine stress echocardiography for detecting coronary artery disease was evaluated in 67 patients with normal left ventricular wall motion at rest who also underwent quantitative angiography. The overall sensitivity and specificity of dobutamine stress echocardiography for detecting coronary artery disease were 83% and 70%, respectively. The sensitivities for detecting multivessel disease and single vessel disease were 92% and 76%, respectively. The sensitivity of dobutamine stress echocardiography was 91% in patients treated without beta-blocker, and 70% in patients treated with beta-blocker (p < 0.001). The relatively low peak heart rate during dobutamine infusion in patients treated with beta-blocker seems to affect the sensitivity of dobutamine stress echocardiography. There were no severe complications during dobutamine infusion. Dobutamine stress echocardiography is a safe and accurate method for detecting coronary artery disease. However, an additional technique to increase peak heart rate in patients treated with beta-blocker such as injection of atropin should be considered.

Angiography, Digital Subtraction↗

PubMedDate not supplied

[Residual, recurrent mitral regurgitation after mitral valve reconstruction: differences in lesion and operation method].

Patients developing residual or recurrent mitral regurgitation (MR) increased to moderate or severe grade after mitral valve reconstruction for MR were investigated by correlating the lesion and operation method with the echocardiographic course of postoperative MR. Postoperative moderate or severe grade MR [more than 4.0 cm2 color Doppler flow area on postoperative transesophageal echocardiography (TEE)] occurred in 21 of 80 mitral valve reconstruction patients. If residual MR caused more than 2.0 cm2 color Doppler flow area on intraoperative TEE, the MR increased to moderate or severe grade during the follow-up period. Postoperative moderate or severe MR occurred more frequently in lesions of the anterior mitral leaflet than the posterior mitral leaflet (45.8% vs 6.5%, p < 0.001), and in elongated chordae than in torn chordae (52.9% vs 14.3%, p < 0.005). Chordal shortening for elongated chordae could correct MR at operation but MR recurred and increased gradually to moderate or severe grade in half of these cases. Chordal reconstruction with polytetrafluorethylene suture is expected to achieve better results than chordal shortening. The causes of postoperative MR could usually be identified by comparative investigation of echocardiographic course, lesion, and operation method. Postoperative moderate or severe MR occurs more often in lesions of the anterior mitral leaflet or cases of elongated chordae. Residual MR should be suppressed to less than 2.0 cm2 color Doppler flow area on intraoperative TEE.

Aged↗

PubMedDate not supplied

[Improvement of transthoracic pulsed Doppler imaging of pulmonary venous flow by intravenous injection of sonicated albumin].

Enhancement of pulmonary venous Doppler flow signals by intravenous injection of sonicated albumin was evaluated in 200 patients. Baseline pulsed Doppler signals were strong in 153 (77%) patients and weak in 47 patients. After injection of sonicated albumin, adequate pulsed Doppler flow signals were recorded in 44 (94%) of the 47 patients. Pulsed Doppler recordings could therefore achieve quantitative analysis in 197 patients (98%, p < 0.01). Signals were enhanced in proportion to the sonicated albumin dose (p < 0.01). No remarkable symptoms or complications were seen during and after examinations. Intravenous sonicated albumin improves transthoracic pulsed Doppler imaging of pulmonary venous flow. This simple and safe technique will obviate transesophageal recordings of pulmonary venous flow in adult patients and facilitate further studies of its diagnostic and monitoring value.

Albumins↗

PubMedDate not supplied

[Relationship between early peaking of serum myosin light chain 1 level and washout phenomenon of creatine kinase in acute myocardial infarction].

To investigate the serum levels of myosin light chain 1 (MLC1) during the acute phase of myocardial infarction, the MLC1 and creatine kinase (CK) levels were measured in samples from 59 consecutive patients with acute myocardial infarction. The serum concentration of MLC1 increased rapidly, reaching an early peak in 22 of the 59 patients (the MLP + group). Fifteen patients showed rapid increases in MLC1 levels without an early peak (the MLP - group). Serum MLC1 levels remained within normal limits (the MLN group) 10 hours after the onset of symptoms in the remaining 22 patients (but in eight of these serum MLC1 levels were abnormal 16-39 hours after the onset of symptoms). Serum level curves of CK showed a single episode of acute myocardial infarction in all patients. The patterns of MLC1 levels correlated with the washout phenomenon of CK (p < 0.001) and the maximum MLC1 level (p < 0.05). The ratio of serum MLC1 level during the early phase to the maximum level (EMR) decreased in the order of groups MLP+, MLP-, MLN (0.54 +/- 0.28, 0.31 +/- 0.22, 0.13 +/- 0.09, respectively). The EMR was correlated with the washout phenomenon of CK (p < 0.001), but not with the maximum MLC1 level which might reflect the size of the infarction. The patterns of neither MLC1 nor EMR were correlated with the administration of urokinase or the patency of the infarct-related artery at the early phase (within 10 hours of onset).(ABSTRACT TRUNCATED AT 250 WORDS)

Creatine Kinase↗

PubMedDate not supplied

Amino acid imbalance and intracellular protein synthesis.

The effects of amino acid imbalance, created by decreasing the concentrations of specific amino acids in culture media, on intracellular protein synthesis were compared with the findings obtained by restricting all amino acids. Protein-synthesis levels were estimated by measuring the uptake rates of 14C-labeled amino acids by cultured rat hepatoma AH109A cells. The inhibitory activity of a 0.1-fold dilution of valine in DM-160 medium was higher than that resulting from the dilution of all amino acids by 0.1-fold. On the other hand, the dilution of other essential amino acids was not as effective as the dilution of all amino acids, whereas the concurrent dilution of valine and leucine was found to be equivalent in effectiveness to the latter. Protein-synthesis levels in 0.3, 0.1, 0.03, and 0.01 mM valine were maximum at 0.9, 0.3, 0.09, and 0.03 mM leucine, respectively. Valine transport into the cell was found to be inversely proportional to the extracellular leucine concentration. DL-Norvaline and DL-norleucine were not effective. Valine-leucine interactions were suggested to be involved in intracellular protein synthesis.

Amino Acids, Essential↗

PubMedDate not supplied

Leucine and manifestation of antitumor activity by valine-depleted amino acid imbalance.

With a commercially available balanced 10% amino acid solution as control (I), imbalance solutions were prepared by the removal of valine (II), valine and leucine (III), valine and isoleucine (IV), and valine, leucine, and isoleucine (V). The solutions, in combination with total parenteral nutrition, were given to rats with AH-109A hepatoma for 7 consecutive days to evaluate antitumor activity. Although there were no significant differences in carcass weight after treatment among groups I-IV, a decrease was noted in group V. Tumor weights in groups II-V, relative to that in group I, were 39, 57, 43, and 44%, respectively. Antitumor activity was thus noted in all imbalance groups, although activity in group III was lower than that in group II. These results indicate that the concurrent depletion of leucine and/or isoleucine along with valine is undesirable because of lower antitumor activity and an adverse effect on host development. Leucine is thus suggested to play an important role in augmenting the activity of valine-depleted imbalance.

Amino Acids↗