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Biomedical subjects

A Uchiyama

Publications and source records attributed to A Uchiyama.

At least 55 records · Page 3Linked to original sources
PubMed1999

Hepatocyte growth factor and invasion-stimulatory activity are induced in pleural fluid by surgery in lung cancer patients.

Hepatocyte growth factor (HGF) is a stromal cell-derived cytokine that can stimulate matrix invasion by carcinoma cells. We analysed the concentrations of HGF and invasion-stimulatory activity in pleural fluid after lung surgery. The concentration of HGF in pleural fluids was measured by enzyme-linked immunosorbent assay in seven patients who underwent pulmonary resection for primary or metastatic lung cancer. The effect of the pleural fluid on cancer cell invasion across reconstituted basement membrane (Matrigel) was assessed with a Boyden chamber assay using a lung adenocarcinoma cell line, A549. HGF levels in the pleural fluid after lung surgery ranged from 6.0 to 23.0 ng ml(-1) (average: 10.2 +/- 4.3 ng ml(-1)). The matrix invasion of lung carcinoma cells in the presence of the pleural fluid was significantly higher than that in the presence of culture medium alone or sera from normal subjects (P < 0.01). The invasion-stimulatory activity of the pleural fluid was strongly inhibited by HGF-neutralizing antibody. Positive correlation was found between the HGF level and invasion-stimulatory activity in the pleural fluids and normal sera (P = 0.0073). This is the first report demonstrating that the lung surgery induces a considerable amount of HGF, which is closely correlated with the invasion-stimulatory activity of the pleural fluid.

Aged↗
PubMed1999

Adrenoleukodystrophy protein enhances association of very long-chain acyl-coenzyme A synthetase with the peroxisome.

OBJECTIVE: To clarify the function of adrenoleukodystrophy protein (ALDP) using our ALDP-deficient mice established by gene targeting. BACKGROUND: X-linked adrenoleukodystrophy (ALD) is characterized biochemically by the accumulation of very long-chain fatty acids (VLCFA) in tissues and body fluids, and is caused by impairment of peroxisomal beta-oxidation. In ALD, very long-chain acyl-coenzyme A synthetase (VLACS), which is necessary for peroxisomal beta-oxidation, does not function. METHODS: The ALDP-deficient mice and C57BL/6J mice were used. VLACS or ALDP were transiently expressed by lipofection in murine fibroblasts, and VLCFA beta-oxidation was assayed. Liver peroxisomes were purified by sequential centrifugations and a Nycodenz gradient centrifugation. The peroxisomal localization of VLACS was compared between the mutant and control mice using a Western blot analysis. RESULTS: Impairment of VLCFA beta-oxidation in ALDP-deficient fibroblasts was not corrected by the additional expression of VLACS alone but was by the coexpression of VLACS and ALDP. Although the tissue-specific expression of VLACS was similar in ALDP-deficient and normal mice, peroxisomal VLACS was clearly lower in ALDP-deficient than in normal mice. CONCLUSIONS: ALDP plays a role in the peroxisomal localization of VLACS, and VLACS does not function unless localized in the peroxisome.

ATP Binding Cassette Transporter, Subfamily D, Mem↗
PubMed1999

[Postoperative respiratory management in patients undergoing radical surgery with three fields lymph node dissection for thoracic esophageal cancer: clinical benefits of assisted ventilation with mini-tracheostomy].

The benefits of early extubation and assisted ventilation with mini-tracheostomy and preventive positive pressure ventilation in the early stage after thoracic esophageal cancer operation are examined and compared. Subjects were 23 patients who underwent radical operation for thoracic esophageal cancer in our hospital over a 5 year period. Ten patients (A group) underwent positive pressure ventilation with postoperative intubation for a certain period. Thirteen patients (B group) were extubated the day after operation, then immediately mini-tracheostomized, and then intermittent high-frequency jet ventilation during the daytime and pressure controlled ventilation during the nighttime were conducted. There were no differences in background factors between the two groups. The mean period of tracheal intubation was 8.8 days in the A group and 1.6 days in the B group. The mean period of stay in ICU was 13 days in the A group and 7 days in the B group. Both such periods were significantly shorter in the B group than in the A group. Respiratory control by early extubation and mini-tracheostomy after thoracic esophageal cancer operation is considered to have the following two benefits; 1. The method is performed safely, and makes sputum suction easier and assisted respiration conductible. 2. The method reduces the incidence of pulmonary complications and shortens the period of stay in ICU.

Aged↗
PubMed1998

Developmental characteristics in sustained fetal tachycardia in 30 to 41 weeks of gestation.

The aim of the present study is to reveal gestational age-related changes in sustained foetal tachycardia (SFT). 24 h fetal heart rate (FHR) recordings were made on 102 normal pregnant women in 30-41 weeks of gestation. SFT was defined as an increase for 20 or more beats per minute from the FHR-baseline persisting for more than 20 min. In the results, SFTs in 38-39 weeks started during night-time (1900-0700) more frequently than during day-time (0700-1900) (P < 0.01, by chi-square test). The rate and duration were 0% and 0 min in 30-31 weeks of gestation, and increased to 85% and 114 min in 40-41 weeks, respectively. Two critical points were detected by a piecewise linear regression analysis: in the rate between 34-35 weeks and 36-37 weeks, and in the duration between 38-39 to 40-41 weeks. We conclude that gestational age-related changes in SFT depend on the developmental stages.

Behavior↗
PubMed1998

Assessment of c-erbB2 and vascular endothelial growth factor mRNA expression in fine-needle aspirates from early breast carcinomas: pre-operative determination of malignant potential.

AIMS: Although axillary lymph nodes status, tumour size, hormonal-receptor status and histological grade at diagnosis are frequently used to orient the treatment of breast cancer patients, some tumours recur in patients with early stage disease. Pre-operative assessment of individual tumour characteristics, based on oncogenes and growth factors related to tumour growth, invasion or metastasis, may guide the treatment for patients with breast carcinomas. METHODS: We examine here the prognostic significance of cyclin D1, urokinase type plasminogen activator, vascular endothelial growth factor (VEGF), platelet-derived growth factor, and c-erbB2 expression in pre-operatively obtained fine-needle aspirates from breast carcinomas less than or equal to 3 cm in size. Correlation between mRNA expression of these factors and clinicopathological characteristics was analysed. RESULTS: The level of c-erbB2 mRNA expression was significantly higher in tumours with lymph node metastases than in those without lymph node metastases. VEGF mRNA expression positively correlated with the degree of angiogenesis as quantitated by immunohistological staining with a CD31 monoclonal antibody. CONCLUSIONS: Analysis of c-erbB2 and VEGF mRNA expression in fine-needle aspirates may be useful in assessing the malignant potential of individual breast carcinomas, leading to a pre-operative discrimination of a high-risk group.

Actins↗
PubMed1998

Development of a health promotion system for the elderly: Committee of Health Evaluation for Elderly Persons Council of Japan AMHTS Institutions.

A new health promotion approach for elderly persons is required which maintains not only their physical health but also their quality of life. We are developing a health promotion system which makes use of questionnaires dealing with physical conditions and quality of life, and makes health reports. Health evaluation is carried out in three steps. First, detailed information about the physical health of each client is collected. Second, quality of life is evaluated according to five health indicators. Last, health recommendations are generated. An artificial intelligence (AI) program produces detailed questions to collect necessary information for the evaluation of a client's health. The information related to quality of life is converted into five health indicators and presented as a radar-chart in documents and displays. The knowledge-based AI program automatically generates the health recommendation documents. This information is available for physicians and nurses for health counseling.

Aged↗
PubMed1998

Effects of pressure-support ventilation on recovery from acute diaphragmatic fatigue in rabbits.

OBJECTIVES: To examine the effects of pressure-support ventilation on recovery from acute diaphragmatic fatigue. DESIGN: Prospective laboratory trial. SETTING: Experimental laboratory. SUBJECTS: Twenty-one healthy, adult New Zealand white rabbits. INTERVENTIONS: Diaphragmatic fatigue was induced with 50-Hz phrenic nerve stimulation for 30 mins. Recovery was compared between pressure-support ventilation 0 cm H2O (SB), 10 cm H2O (P10), and 20 cm H2O (P20) for 90 mins immediately after the end of the fatigue inducing procedure. MEASUREMENTS AND MAIN RESULTS: After the fatigue-inducing procedure, pressure-support ventilation reduced transdiaphragmatic pressure and integrated diaphragmatic electromyogram both at P20 and P10, but not in SB. Recovery was assessed by airway occlusion pressure (Poccl) generated by high- (100 Hz) and low- (20 Hz) frequency phrenic nerve stimulation. Poccl at 100 Hz was lower in P10 and P20 than in SB (74.6 +/- 6.2 [SEM] %, 66.9 +/- 3.3%, and 94.8 +/- 3.6% of the baseline at 90 mins for P10, P20, and SB, respectively), while those at 20 Hz showed no differences between the three groups. CONCLUSION: Recovery from acute diaphragmatic fatigue might be disturbed with pressure-support ventilation.

Animals↗
PubMed1998

Chitosanase activity of the enzyme previously reported as beta-1,3-1,4-glucanase from Bacillus circulans WL-12.

Chitosanases 33 kDa and 40 kDa in size were detected in the culture supernatant of Bacillus circulans WL-12. One of the two chitosanases, chitosanse 40 (40-kDa chitosanase) has been shown to be identical to the enzyme which has been reported previously as a beta-1,3-1,4-glucanase by Bueno et al. The enzyme has been classified into family 8 glycosyl hydrolases together with the enzymes formally known as cellulase family D. This enzyme named chitosanase 40/beta-1,3-1,4-glucanase hydrolyzed both chitosan and beta-1,3-1,4-glucan with similar efficiency. However, the production of the enzyme was induced with chitosan but not by beta-1,3-1,4-glucan. Therefore, it seems possible that the major substrate of this enzyme is chitosan rather than beta-1,3-1,4-glucan. Analysis of degradation products generated from partially N-acetylated chitosan showed that chitosanase 40/beta-1,3-1,4-glucanse hydrolyzes GlcN-GlcN and GlcN-GlcNAc linkages but not GlcNAc-GlcNAc nor GlcNAc-GlcN. The specificity for hydrolyzing linkages of this enzyme is similar to that of the chitosanase from S. griseus HUT6037.

Bacillus↗
PubMed1998

Simulator for virtual surgery using deformable organ models and force feedback system.

This paper describes a real-time surgery planning system using virtual reality techniques. This system allows us to simulate incision of skin and organs which respond as elastic objects with surgical tools in virtual space. Inner structures such as blood vessels and lesions can be seen and manipulated in the simulation. In addition to these functions we attempted to add a feedback function that responds to the operator's hands. We developed a force feedback device to manipulate the elastic organ model based on pressure from the operator's fingers.

Abdomen↗
PubMed1998

Resistance index of uterine artery and placental location in intrauterine growth retardation.

BACKGROUND: Our aim was to investigate the relationship between placental location and resistance index (RI) of uterine arteries in cases with intrauterine growth retardation (IUGR). METHODS: Placental location and flow velocity waveforms of uterine arteries in 86 normal and 20 IUGR cases from 33 to 38 weeks of gestation were examined using a combined real-time scanner and pulsed Doppler ultrasonography. The location of placenta was classified as lateral when most of it was located to either the right or the left side of the uterine midline. Otherwise it was called central. Cases where the placenta was located in the uterine fundus or in the lower segment were not included. RI values were calculated from the uterine arteries on the placental side, on the non-placental side and in case of central placentas as a mean of both uterine arteries. In normal cases, the calculations were done every second week from 33 to 38 weeks of gestation, and the difference in variance among three gestational ages in each artery was tested by a one-way ANOVA. In IUGR cases, a standard deviation score (SDS) was calculated individually in each artery as (RI - normal mean)/normal SD. Differences in SDS between three categories of uterine arteries were examined by non-parametric tests. RESULTS: In normal cases, there was no significant difference in variance of RIs among three gestational ages in each category of arteries. In IUGR cases, SDSs on the placental side were higher than those on the non-placental side and those in central placenta, (p<0.01, Wilcoxon's and Mann Whitney's tests, respectively). SDSs in five of eight cases with central placentas were below 1.0. Two of 12 cases with lateral placentas had higher SDSs on the non-placental side than on the placental side and resulted in abruptio placentae. CONCLUSIONS: Deviation of RIs in uterine arteries with IUGR could be affected by the pathologic conditions of the utero-placental blood flow on the placental side of lateral placenta rather than in central placenta and might be done by dramatic increase in resistance to flow of the myometrial vessels on the non-placental side.

Female↗
PubMed1998

[Creation of a dynamic digital phantom and its application to a kinetic analysis].

A dynamic digital brain phantom was created from the MRI to evaluate visually the relationship between the noise and the error in the parameter estimates in the PET kinetic analysis. This phantom incorporates the noise level depending on administration dose, camera efficiency and the data acquisition schedule. We simulated a serial dynamic scan with 18F-FDG or 11C-flumazenil, assuming 2-tissue 3-parameter model and 1-tissue 2-parameter model, respectively, and the sampling schedule was determined according to the clinical examination. The noise in the tissue time activity curve in FDG had a peak in the first minute and decreased thereafter, whereas the noise increased gradually in the flumazenil study after the initial peak due to radioactivity decay. We examined the relationship between the noise level and the error in the parameter estimates. Both mean absolute differences between true and estimated values and standard deviation became large, and the quality of the parametric images became poor with increasing noise level. This simulation was compared with human tissue time activity curves and parametric images, which were obtained with 100 MBq administration dose in FDG study and 430 MBq in flumazenil study. We inferred that the noise level in the human study was 10-20% in FDG, and 20-40% in flumazenil, and the error in the estimated parameter of K-complex in FDG study was about 20%, that of DV in flumazenil study was 2%.

Brain↗
PubMed1997

Preoperative assessment of tumor angiogenesis by vascular endothelial growth factor mRNA expression in homogenate samples of breast carcinoma: fine-needle aspirates vs. resection samples.

BACKGROUND AND OBJECTIVES: Tumor angiogenesis is receiving increased attention as a prognostic factor and also as a possible target for new anticancer agents. We investigated whether extent of vascular endothelial growth factor (VEGF) mRNA expression correlated with degree of neovascularization, and whether this expression in fine-needle aspirates could be a marker for assessing angiogenic potential of breast tumors. METHODS: VEGF mRNA expression was semiquantitated by reverse transcriptase-polymerase chain reaction (RT-PCR) followed by Southern blotting. Tumor neovascularization was assessed by immunohistochemical staining with anti-CD31 (PECAM) antibody. RESULTS: There was a positive correlation between degree of neovascularization and semiquantitated VEGF mRNA expression in invasive ductal carcinomas (r2 = 0.346, n = 48, P < 0.05). Extent of VEGF mRNA expression in fine-needle aspirates was closely correlated with that in resected invasive ductal carcinomas equal to or less than 3 cm in size (r2 = 0.874, n = 14, P < 0.05). CONCLUSION: These data suggest that semiquantitation of VEGF mRNA expression in fine-needle aspirates is useful for assessing angiogenic potential of invasive ductal carcinomas.

Biopsy, Needle↗
PubMed1997

The effect of behavioral states on fetal heart rate and middle cerebral artery flow-velocity waveforms in normal full-term fetuses.

OBJECTIVES: To evaluate the effect of fetal behavioral states on the relationship between fetal heart rate (FHR) and middle cerebral artery resistance index (MCA RI) in normal fetuses. METHODS: The FHR and MCA RI of 10 normal cases from 37 to 40 weeks of gestation were recorded consecutively over a 45-min period. Correlations between the MCA RI and FHR during resting and active phases, classified by an actocardiotocogram, were analyzed by simple regression analysis. RESULTS: The mean FHR and MCA RI were significantly higher during the active phase (140.3 +/- 6.6 bpm, 0.79 +/- 0.06) than those during the resting phase (137.4 +/- 6.8 bpm, 0.75 +/- 0.07, P < 0.01, two sample t-test). There was a significant negative correlation (r = - 0.22, n = 2642, P < 0.01) between RI and FHR during the active phase and a significant positive correlation (r = 0.28, n = 2066, P < 0.001) during the resting phase. CONCLUSIONS: The relationship between FHR and the MCA RI during the resting phase is different from during the active phase.

Behavior↗
PubMed1997

Nitric oxide (NO) measurement accuracy.

BACKGROUND: Evaluation of the clinical utility of NO requires accurate assessment of inspired [NO]. Currently, chemiluminescence analyzers are the clinical standard for analysis; however, their performance in the clinical setting has not been systemically evaluated. METHODS: We evaluated the performance of four chemiluminescence analyzers (270B NOA, Sievers Instruments, Inc.; CLA 510S, Horiba Co., Ltd.; CLD 700 AL, Eco Physics Corp.; Model 42, Thermo Environmental Instruments Inc.) in simulated clinical settings. Transport delay and dynamic 95% response time were measured by the balloon in a glass chamber puncture technique. Fluctuating [NO] in a continuous flow of gas and [NO] during mechanical ventilation, where NO was premixed prior to entering the ventilator, were evaluated. RESULTS: Transport delay ranged from 1.02 +/- 0.02 to 24.36 +/- 2.47 s (p < 0.05) and the 95% response time ranged from 0.22 +/- 0.04 to 70.03 +/- 0.03 s (p < 0.05). Accurate analysis of [NO] in a continuous flow system was only possible with the most rapid response analyzer (270B NOA). All other analyzers under reported the maximum [NO] (p < 0.05) and over reported the minimum [NO] (p < 0.05). All analyzers accurately determined [NO] in the inspiratory limb of the ventilator circuit, but none accurately determined [NO] at the airway opening. CONCLUSIONS: Measurements of inhaled [NO] can vary greatly, dependent upon the performance characteristics of the analyzer and the location of NO analysis. All studies evaluating the clinical use of NO should fully describe the technical gas delivery methodology and the response time and transport delay of the chemiluminescence analyzer used.

Administration, Inhalation↗
PubMed1997

Mapping visual field with positron emission tomography by mathematical modeling of the retinotopic organization in the calcarine cortex.

We developed an objective and quantitative method of mapping the human visual field with positron emission tomography (PET) and magnetic resonance image (MRI). The regional cerebral blood flow (rCBF) images were acquired with H2(15)O-PET under visual fixation as well as under visual stimulation with flickering diodes arranged along the ring at 0 degree, 3 degrees, 7 degrees, 14 degrees, 21 degrees, or 29 degrees from the fixation point. After coregistration of PET and MR images, we extracted the surface of the calcarine cortex from the MR images and unfolded it to a two-dimensional (2-D) elliptic plane, on which the activated PET images were superimposed. Then we transformed the unfolded calcarine cortex into the visual field coordinates using the complex logarithmic function proposed by Schwartz. A large individual variation was observed in the retinotopical organization as well as in the morphology of the calcarine cortex. The formula was valid only within 15 degrees from the center of the visual field. The constant parameter in the formula was estimated to be 1.5. The cortical linear magnification factor was 12.1, 2.8, and 1.6 at 0, 5, and 10 degrees, respectively. The areas of the central 10 degrees and 40 degrees in the visual field correspond to 50% and 81% of the calcarine surface, respectively.

Adult↗
PubMed1997

Two novel missense mutations in the ATP-binding domain of the adrenoleukodystrophy gene: immunoblotting and immunocytological study of two patients.

Two novel missense mutations, 1939G to A (R518Q) and 2017A to G (Q544R) were identified in Japanese patients with adrenoleukodystrophy (ALD). They are located in exon 6, which encodes part of the putative adenosine triphosphate binding domain of ALD protein. The ALD protein carrying the R518Q mutation was undetectable in fibroblasts, by immunoblot and immunofluorescence analysis, while the Q544R mutation had no apparent effect on the stability and localization of the ALD protein, but is expected to affect its function.

ATP Binding Cassette Transporter, Subfamily D, Mem↗
PubMed1997

[Comparison of the number of parameters using nonlinear iteration methods for compartment model analysis with 18F-FDG brain PET].

In the analysis of the brain kinetic images with 18F-FDG, compartment models with 3 or 4 parameters and an estimation method of nonlinear least squares (NLS) have been applied. We compared the Simplex method and the modified Marquardt method as an iterative NLS algorithm on the simulation data with variable noise. The estimated k-values were equal in the both algorithms. The calculation with modified Marquardt method was three times faster than that of the Simplex method. The dependence of modified Marquardt estimates on the initial values was larger than that of the Simplex, but the permissible initial value range was wide enough for clinical data. Therefore, the modified Marquardt method was found to be more suitable for the compartment model analysis of 18F-FDG than the Simplex method. We also compared the 3-parameter with 4-parameter models for 45 min and 120 min data acquired after administration. The 3-parameter model was suitable for the 45-minute data acquisition, and the 4-parameter model was suitable for the 120-minute data acquisition.

Algorithms↗