Search PubMed⌕ Search

Biomedical subjects

A Uchiyama

Publications and source records attributed to A Uchiyama.

At least 37 records · Page 2Linked to original sources
PubMed2001

[Quantitative estimation of brain atrophy and function with PET and MRI two-dimensional projection images].

PURPOSE: The purpose of this paper is to estimate the extent of atrophy and the decline in brain function objectively and quantitatively. METHODS: Two-dimensional (2D) projection images of three-dimensional (3D) transaxial images of positron emission tomography (PET) and magnetic resonance imaging (MRI) were made by means of the Mollweide method which keeps the area of the brain surface. A correlation image was generated between 2D projection images of MRI and cerebral blood flow (CBF) or 18F-fluorodeoxyglucose (FDG) PET images and the sulcus was extracted from the correlation image clustered by K-means method. Furthermore, the extent of atrophy was evaluated from the extracted sulcus on 2D-projection MRI and the cerebral cortical function such as blood flow or glucose metabolic rate was assessed in the cortex excluding sulcus on 2D-projection PET image, and then the relationship between the cerebral atrophy and function was evaluated. This method was applied to the two groups, the young and the aged normal subjects, and the relationship between the age and the rate of atrophy or the cerebral blood flow was investigated. This method was also applied to FDG-PET and MRI studies in the normal controls and in patients with corticobasal degeneration. RESULTS: The mean rate of atrophy in the aged group was found to be higher than that in the young. The mean value and the variance of the cerebral blood flow for the young are greater than those of the aged. The sulci were similarly extracted using either CBF or FDG PET images. CONCLUSIONS: The purposed method using 2-D projection images of MRI and PET is clinically useful for quantitative assessment of atrophic change and functional disorder of cerebral cortex.

Adult↗
PubMed2001

Nuclear factor-kappaB p65 (RelA) transcription factor is constitutively activated in human gastric carcinoma tissue.

PURPOSE: Activation of transcription factor nuclear factor-kappaB (NF-kappaB) has been shown to play a role in cell proliferation, apoptosis, cytokine production, and oncogenesis. The purpose of this study was to determine whether NF-kappaB is constitutively activated in human gastric carcinoma tissues and, if so, to determine any correlation between NF-kappaB activity and clinicopathological features of gastric carcinoma. EXPERIMENTAL DESIGN: NF-kappaB activation was determined by immunohistochemical analysis of formalin-fixed, paraffin-embedded specimens from 64 gastric carcinoma patients. We quantified nuclear staining of RelA as a marker of NF-kappaB activation. RESULTS: Nuclear translocation of RelA was significantly high in tumor cells in comparison to that in adjacent normal epithelial cells (22.5 +/- 2.4% versus 8.6 +/- 1.5%, P < 0.0001). There was a significant correlation between NF-kappaB activation (nuclear translocation of RelA) and expression of urokinase-type plasminogen activator, an invasion-related factor and target of NF-kappaB in tumor cells (rho = 0.393; P = 0.0013). NF-kappaB activation was correlated with tumor invasion-related clinicopathological features such as lymphatic invasion of tumor cells (P = 0.0126), depth of invasion (P = 0.0539), peritoneal metastases (P = 0.0538), and tumor size (P = 0.0164). CONCLUSIONS: Collectively, the data show that NF-kappaB is constitutively activated in human gastric carcinoma tissues and suggest that NF-kappaB activity is related to tumor progression due to its transcriptional regulation of invasion-related factors such as urokinase-type plasminogen activator.

Active Transport, Cell Nucleus↗
PubMed2000

Lipopolysaccharide increases cyclo-oxygenase-2 expression in a colon carcinoma cell line through nuclear factor-kappa B activation.

Both nonneoplastic colon epithelium and colon carcinoma cells in situ are continuously exposed to lipopolysaccharide (LPS). Few reports have addressed possible direct effects of LPS in promotion of colon carcinoma and underlying mechanisms. We found evidence that LPS directly stimulated growth of the human colon carcinoma cell line CE-1 through an increase in the production of prostaglandin E2 (PGE2) as a result of cyclo-oxygenase-2 (COX-2) expression. LPS induced significant increases in PGE2 production in CE-1 cells, which were found to express a high-affinity LPS receptor, CD14. Positive correlations were found between PGE2 production and activation of nuclear factor (NF)-kappa B as well as expression of both COX-2 mRNA and protein in LPS-stimulated CE-1 cells. When CE-1 cells were exposed to exogenous PGE2, DNA synthesis increased. These results indicate that LPS may stimulate DNA synthesis in certain colon carcinoma cells as a result of PGE2 production involving increased COX-2 expression that might result in turn from activation of NF-kappa B by LPS. Further investigation of the pathways mediating LPS-induced stimulation of colon carcinoma cells may provide insights into LPS effects in in vivo tumor biology.

Adenocarcinoma↗
PubMed2000

Laparoscopically assisted distal gastrectomy for early gastric cancer: is it superior to open surgery?

BACKGROUND: The purpose of this study was to compare clinical outcomes between laparoscopically assisted and open distal gastrectomy for early gastric cancer. METHODS: The records of 21 patients who underwent laparoscopically assisted distal gastrectomy (LG) for preoperative diagnosis of intramucosal gastric carcinoma between January 1996 and August 1998 were reviewed and compared with those of 31 open distal gastrectomy patients during the same period. RESULTS: Age, gender, and size and histologic differentiation of the lesions were matched. Those located at the body of the stomach (p = 0.011) and those macroscopically depressed (p = 0.049) were subjected more frequently to open surgery. Laparoscopically assisted gastrectomy required significantly longer operative time (p < 0.001) with less extensive lymph node dissection (p < 0.001). However, time to start of walking (p = 0.032), time to flatus (p = 0.002), duration of postoperative fever (p = 0.027), and postoperative hospital stay (p = 0.001) were significantly shorter in the LG group, and this group had a lower white blood cell count on the first postoperative day (p = 0.010). Blood loss and time to oral intake were comparable between the groups. Complications included one conversion to open surgery, one leakage, and one stenosis in the LG group, and two leakages and an atelectasis in the OG group. CONCLUSIONS: Although LG requires longer surgical time, this retrospective study suggests that it is superior to open surgery in terms of faster postoperative recoveries, shorter hospital stays, and cosmetic outcomes.

Adenocarcinoma↗
PubMed2000

Protein-bound polysaccharide PSK inhibits tumor invasiveness by down-regulation of TGF-beta1 and MMPs.

Transforming growth factor beta1 (TGF-beta1) and matrix metalloproteinases (MMPs) produced by tumor cells play important roles in tumor invasion. PSK, a protein-bound polysaccharide, is widely used in Japan as an immunopotentiating biological response modifier for cancer patients. In this study, we focused on the effects of PSK on invasiveness, TGF-beta1 production, and MMPs expression in two human tumor cell lines, pancreatic cancer cell line (NOR-P1) and gastric cancer cell line (MK-1P3). PSK significantly decreased the invasiveness of both cell lines through Matrigel-coated filters but did not affect cell viability, proliferation, or adhesion. Decreased invasion was associated with the inhibition of TGF-beta1, MMP-2, and MMP-9 at both mRNA and protein levels as assessed by reverse transcriptase-polymerase chain reaction, gelatin zymography, and enzyme-linked immunosorbent assay. Antibody against TGF-beta1 neutralized the MMP activities of both cell lines. PSK also suppressed the expression of urokinase plasminogen activator (uPA) and uPA receptor but did not change plasminogen activator inhibitor-1 (PAI-1) expression. Western blot analysis showed that PSK reduced uPA protein expression but not PAI-1 expression in the both cell lines. These results indicate that PSK suppresses tumor cell invasiveness through down-regulation of several invasion-related factors including TGF-beta1, uPA, MMP-2, and MMP-9.

Adjuvants, Immunologic↗
PubMed2000

Optimal level of pressure support ventilation for recovery from diaphragmatic fatigue in rabbits.

OBJECTIVE: To determine whether there is an optimal level of pressure support ventilation (PSV) for recovery from acute diaphragmatic fatigue. DESIGN: Prospective laboratory trial. SETTING: Experimental laboratory. SUBJECTS: Twenty healthy adult New Zealand White rabbits. INTERVENTIONS: Diaphragmatic fatigue was induced with 50 Hz of phrenic nerve stimulation for 30 mins. Recovery was compared between inspiratory load + PSV of 0 cm H2O (L0), inspiratory load + PSV of 60 cm H2O (L60), inspiratory load + PSV of 80 cm H2O (L80), and PSV of 0 cm H2O without inspiratory load (SB) for 90 mins immediately after the end of the fatigue-inducing procedure. To add inspiratory load during the recovery phase, three pressure threshold valves, each having an opening pressure of -20 cm H2O, were used. MEASUREMENTS AND MAIN RESULTS: After the fatigue-inducing procedure, diaphragmatic electromyogram and transdiaphragmatic pressure remained at baseline in both SB and L60, decreased in L80, and increased in L0. Recovery was assessed by abdominal cavity pressure (Pabd) generated by high-frequency (100 Hz) and low-frequency (20 Hz) stimulation. Pabd at 100 Hz recovered to baseline in L60 and SB but not in L0 and L80 (69.1%, 81.3%, 100.3%, and 100.7% of the baseline at 90 mins for L0, L80, L60, and SB, respectively). Pabd at 20 Hz did not differ among ventilatory settings. CONCLUSION: There is an optimal range of PSV assist level to improve recovery from diaphragmatic fatigue. Recovery was hampered not only by inadequate PSV but also by excessive PSV.

Airway Resistance↗
PubMed2000

Very-long-chain fatty acid metabolism in adrenoleukodystrophy protein-deficient mice.

X-linked adrenoleukodystrophy (X-ALD) is characterized by progressive mental and motor deterioration, with demyelination of the central and peripheral nervous system. Its principal biochemical abnormality is the accumulation of very-long-chain fatty acids (VLCFAs) in tissues and body fluids, caused by the impairment of peroxisomal beta-oxidation. The authors have generated a line of mice deficient in ALD protein (ALDP) by gene targeting. ALDP-deficient mice appeared normal clinically, at least up to 12 mo. Western blot analysis showed absence of ALDP in the brain, spinal cord, lung, and kidney. The amounts of C26:0 increased by 240% in the spinal cord. VLCFA beta-oxidation in cultured hepatocytes was reduced to 50% of normal. The authors investigated the roles of ALDP in VLCFA beta-oxidation using the ALDP-deficient mice. Very-long-chain acyl-CoA synthetase (VLACS) is functionally deficient in ALD cells. The impairment of VLCFA beta-oxidation in the ALDP-deficient fibroblasts was not corrected by over-expression of VLACS only, but was done by co-expression of VLACS and ALDP, suggesting that VLACS requires ALDP to function. VLACS was detected in the peroxisomal and microsomal fractions of the liver from both types of mice. Peroxisomal VLACS was clearly decreased in the ALDP-deficient mouse. Thus, ALDP is involved in the peroxisomal localization of VLACS.

ATP Binding Cassette Transporter, Subfamily D, Mem↗
PubMed2000

[Seven patients with stage IVb advanced gastric cancer who were treated with preoperative chemotherapy].

We examined the usefulness of preoperative chemotherapy using 5-FU and low-dose CDDP in patients with stage IVb gastric cancer. Between 1996 and 1998, seven patients with stage IVb gastric cancer who received preoperative chemotherapy achieved complete or partial response. One course of the chemotherapy was as follows: arterial or venous infusion of 5-FU (500 or 250 mg/day on day 1-5) and low-dose CDDP (5-10 mg/day on day 1-5) for three weeks. In addition to preoperative chemotherapy, biological response modifiers such as OK-432 and lentinan were used. We evaluated the response with abdominal or chest CT and tumor markers. Although preoperative chemotherapy did not improve the survival rate significantly, the prognosis of these patients seemed to be relatively good. Only slight side effects were found. These results suggest that preoperative chemotherapy using 5-FU and low-dose CDDP may be useful for patients with stage IVb gastric cancer.

Aged↗
PubMed2000

Subjective symptoms acquisition system in a health promotion system for the elderly. Committee of System Development, Council of Japan AMHTS Institutions.

A previous report was concerned with the evaluation of quality of life using a Health Promotion System for the Elderly. In the present report, we describe one part of that system: a subjective symptoms acquisition and reporting system. The main purpose of this system is to permit any physician or nurse to uniformly employ questionnaires to acquire accurate subjective symptoms. This system is applied in three steps. First, the subjective answers to 21 questions displayed on a personal computer are obtained. These answers correspond to the basic subjective symptoms. Second, if a basic subjective symptom is "positive", more detailed questions are automatically generated. Finally, clear sentences regarding subjective symptoms are generated and output as a "finding report". This information is helpful to physicians and nurses in their health-counseling work. An artificial intelligence (AI) program based on "XpertRule" produces detailed questions which are generated by an interactive questionnaire using branching logical rules.

Aged↗
PubMed2000

[Clinical symptoms and characteristic MR spectroscopic findings in Pelizaeus-Merzbacher disease].

Clinical symptoms and MR spectroscopic findings were studied on 4 cases of Pelizaeus-Merzbacher disease including 1 autopsy case. Common symptoms were severe mental retardation and spastic tetraplegia. These cases had nystagmus, and one had involuntary athetotic movement. Genetical diagnosis revealed in 2 cases, duplication of proteolipid protein (PLP) and deletion in 1, whereas one case had no abnormality of PLP gene. MRI indicated the reversal of signal intensities on T1- and T2-weighed images, a characteristic finding of PMD MR spectroscopy demonstrated a pattern of NAA in 3 cases. This was specific to PMD because other white matter diseases show a decrease in NAA. In conclusion, MRS was useful to differentiate PMD from other white matter diseases.

Adult↗
PubMed1999

An early gastric carcinoma treatment strategy based on analysis of lymph node metastasis.

BACKGROUND: Newly developed therapies for early gastric carcinoma attempt to consider patients' quality of life, but the applicability and effectiveness of these treatments remain undetermined. METHODS: Clinicopathologic data of 612 consecutive patients with early gastric carcinoma, all of whom were treated by D1 and D2 gastrectomy, were analyzed. Patients with and without lymph node metastases were compared in relation to age and gender distributions, surgical procedures, histopathology of the tumors, 5-year prognosis, and in reference to the preoperative and intraoperative assessments. RESULTS: The overall incidence of lymph node metastases was 5.7%. Tumor depth and size were related to lymph node metastases judged by univariate and multivariate analyses. Patients with mucosal tumors showed no relation between metastatic rate and tumor size, whereas those with submucosal tumors showed an increasing metastatic rate with tumor size. In all cases but one, lymph node metastases were confined to lymph node stations defined as Group 1 locations. Preoperative endoscopic ultrasonography showed a 55% diagnostic accuracy in determining tumor depth and a 15% sensitivity in diagnosing lymph node metastases. CONCLUSIONS: Patients with early gastric carcinoma may be candidates for endoscopic mucosal resection if their tumor is confined to the mucosa and measures < 1 cm in greatest dimension. Other limited resections including D1 gastrectomy or standard D2 gastrectomy based on tumor depth and size are appropriate. Based on the current study findings, the authors propose a useful algorithm for managing such patients.

Age Factors↗
PubMed1999

Nitric oxide synthase expression and nitric oxide production in human colon carcinoma tissue.

BACKGROUND AND OBJECTIVES: Nitric oxide (NO), the production of which is dependent on NO synthase (NOS), has been shown to contribute to various pathogeneses in cancer. The aim of this study was to determine whether inducible NO synthase (iNOS) is overexpressed in human colon carcinoma tissue, and whether NO is produced in tumor tissue. METHODS: We investigated iNOS mRNA expression in 24 human colon carcinoma tissue specimens by reverse transcription-polymerase chain reaction (RT-PCR). We then examined the expression of iNOS protein and nitrotyrosine, which indicates NO production in tissue, by immunohistochemistry. The possible immunosuppressive role of NO produced by colon carcinoma cells was analyzed in vitro. RESULTS: Semiquantitative RT-PCR analysis showed that iNOS mRNA expression in carcinoma tissues is elevated significantly compared to that in noncarcinoma tissue. Immunohistochemistry revealed that iNOS and nitrotyrosine are expressed strongly in carcinoma tissues. In vitro experiments showed that the supernatant from a culture of cytokine-treated colon carcinoma cells, which contained high levels of NO, significantly reduced the phytohemagglutinin (PHA)-stimulated, human lymphocyte proliferative response (60% of the control value). CONCLUSIONS: In human colon carcinoma tissue, iNOS mRNA, protein, and NO products are overexpressed and may contribute to tumor-related immunosuppression.

Adenocarcinoma↗
PubMed1999

Benign mediastinal teratoma complicated by cardiac tamponade: report of a case.

We present herein the case of a 48-year-old woman with a benign mediastinal teratoma that had been followed up for 3 years, who developed acute cardiac tamponade. The patient had initially undergone an exploratory sternotomy, at which time the tumor was histologically diagnosed as a benign mature teratoma that could not be resected due to its severe, wide adhesion to the surrounding organs. However, following the development of cardiac tamponade, both sternotomy and right intercostal thoracotomy were employed, and the tumor could be excised with cardiopulmonary bypass standby. High levels of amylase and carbohydrate antigen 19-9 were revealed in the pericardiac effusion fluid. The mRNA expression of inflammatory cytokines including interleukin-1 (IL-1), IL-6, and IL-8 in the tumor tissue was also demonstrated by a reverse transcriptase-polymerase chain reaction analysis. This case illustrates the ultimate natural course of benign mediastinal teratoma and emphasizes the importance of early surgical excision, even when this tumor is asymptomatic.

Base Sequence↗
PubMed1999

Mediastinal lymph node metastasis of colon cancer: report of a case.

We herein describe a patient with mediastinal lymph node metastases which occurred after both a primary sigmoid colon cancer and metachronous ovarian metastasis had been resected. The most likely route of metastases to the mediastinum in this case is the paravertebral venous plexus probably connected to the ovarian metastasis, or so-called remetastasis. This case illustrates that the mediastinum is thus a possible metastatic site in patients with colon cancer. Surgeons should therefore pay attention to the mediastinum as well as the lung fields when checking chest X-ray films during a follow-up of patients after a resection of colon cancer.

Adenocarcinoma↗
PubMed1999

Dynamic measurement of intrinsic PEEP does not represent the lowest intrinsic PEEP.

OBJECTIVE: Dynamic intrinsic PEEP (PEEPi-dyn) is the airway pressure required to overcome expiratory flow and is considered to represent the lowest regional PEEPi. However, there are few data to validate this assumption. We investigated if PEEPi-dyn represents the lowest PEEPi. SETTING: The animal laboratory at the Osaka University Medical School. MEASUREMENTS AND RESULTS: We compared static PEEPi (PEEPi-stat) and PEEPi-dyn in healthy animals. Five adult white rabbits (2.77+/-0.05 kg) were anesthetized, tracheostomized, and intubated with several different sizes of endotracheal tubes (ETT) (2.0, 2.5, 3.0, 3.5, or 4.0 mm i.d.). The animals were paralyzed and ventilated (Siemens Servo 900C). Baseline ventilator settings were at a rate of 50/min, inspiratory:expiratory (I:E) ratio of 2:1 or 4:1, and minute ventilation was manipulated to create 3 or 5 cm H2O PEEPi-stat. PEEPi-stat was measured using the expiratory hold button of the ventilator. PEEPi-dyn showed large variations. In all ventilator settings, PEEPi-dyn was higher than PEEPi-stat (p<0.001). The larger the ETT, the higher the PEEPi-dyn at an I:E ratio of 2:1 (p<0.05). The higher the minute ventilation, the greater the difference between PEEPi-stat and PEEPi-dyn. The tidal volume and the difference showed a significant correlation (r2 = 0.514, p<0.001). CONCLUSIONS: The value of PEEPi-dyn was dependent on ventilatory settings, and PEEPi-dyn does not necessarily represent the lowest regional PEEPi within the lungs.

Animals↗