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Biomedical subjects

N Hayashi

Publications and source records attributed to N Hayashi.

At least 163 records · Page 9Linked to original sources
PubMed2000

Radiologic spectrum of rectal stenosis.

Rectal stenosis is a common condition caused by a wide variety of diseases, including both intrinsic and extrinsic disorders, as well as both malignant and benign pathologies. Barium enema, CT, and MRI are the primary modalities for the evaluation of the disease, and careful observation of the characteristic radiologic features usually leads to correct diagnosis. However, some of the lesions looks very similar and are difficult to differentiate from each other. The purpose of this study is to review the literature on diseases that cause rectal stenosis, to clarify the characteristics of radiologic features, and to suggest the limitations in differential diagnosis. Deliberate analysis of these imaging features and correlation with clinical manifestations can facilitate a more specific diagnosis.

Diagnostic Imaging↗
PubMed2000

Clinicopathologic evaluation of the trend toward histologically poor differentiation with submucosal invasion in superficial early colorectal adenocarcinomas.

We examined differences in the degree of differentiation in intramucosal and submucosal areas of involvement in early colorectal adenocarcinomas of 131 patients and compared these findings with tumor morphology. In addition, K-ras and p53 protein expression was determined in cases where poorly differentiated adenocarcinoma was detected in the submucosa. We identified 6 patients with both intramucosal differentiated (well-to-moderately differentiated) adenocarcinoma and submucosal poorly differentiated adenocarcinoma (MwSp). The morphological tumor type was superficial in all MwSp cases. The observed MwSp adenocarcinomas had a significantly higher frequency of lymphatic invasion than the more common superficial type of adenocarcinoma. Genetic analysis of these MwSp lesions was carried out using the polymerase chain reaction-restriction fragment-length polymorphism (PCR-RFLP) method to detect the presence of K-ras codon 12 point mutations, and an immunologic staining technique was used to identify the presence of p53 protein overexpression. The K-ras mutation rate was 33.3%, and the p53 overexpression rate was 66.7% for the MwSp adenocarcinomas. Our findings suggest that the rapidly reduced histologic differentiation observed in some of these superficial colorectal adenocarcinomas may play a role in their higher degree of invasiveness.

Adenocarcinoma↗
PubMed2000

Successful treatment of recurrent liver metastases from gastric cancer by repeated hepatic resections: report of a case.

We describe herein the case of a patient in whom recurrent liver metastases from gastric cancer were successfully treated by performing repeated hepatic resections. A 63-year-old man underwent a total gastrectomy with regional lymph node dissection for an advanced gastric cancer on November 17, 1992, the pathological findings of which confirmed a diagnosis of well-differentiated tubular adenocarcinoma, ss, INFalpha, ly1, v0, n1(+). Follow-up computer tomography (CT) and ultrasonography scans done 7 months after the gastrectomy revealed a metastasis in the liver S5, and a partial resection of S5 was performed on July 5, 1993. Subsequently, on November 17, 1994, an anterior segmentectomy of the liver was performed for a liver metastasis in the liver S8, then on August 11, 1998, a partial resection of the liver S6 was performed for a metastasis in the liver S6. The pathological findings of each liver specimen resected were compatible with metastatic adenocarcinoma from the primary gastric cancer. The liver tumors were expansive-growing tumors with capsules and massive necrosis. The patient is currently well with no evidence of recurrence on repeat CT scans, 6 years 6 months since-the initial gastrectomy, and 5 years 10 months since the first hepatic resection.

Adenocarcinoma↗
PubMed2000

Multiple inflammatory pseudotumors mimicking liver metastasis from colon cancer: report of a case.

A 54-year-old man underwent an operation for colon cancer histologically diagnosed as moderately differentiated adenocarcinoma with clinical staging of Dukes C. He was prescribed carmofur for adjuvant chemotherapy. A follow-up computed tomography scan done 6 months later revealed two new low-density areas in the liver. A diagnosis of metastatic adenocarcinoma from the previous colon cancer was presumed, based on the patient's history and radiological findings, and resection of the affected area of liver was performed. Histological examination of these tumors revealed that they were inflammatory pseudotumors (IPT). The patient had an excellent postoperative course and has shown no further signs of recurrence in the 3 years since his last operation. IPT of the liver is a rare disease, for which no methods of diagnosis and treatment have been established, since it is difficult to distinguish IPT from hepatocellular carcinoma or metastatic carcinoma. We describe this case with a review of the 101 cases of IPT documented in the Japanese literature, in the hope that it will contribute to the diagnosis and treatment of this unusual disease entity.

Adenocarcinoma↗
PubMed2000

Where does the embryo implant after embryo transfer in humans?

OBJECTIVE: To investigate where human embryos implant after ET. DESIGN: Prospective analysis. SETTING: University hospital. PATIENT(S): Sixty infertile women without uterine fibroids, a major uterine anomaly, or a history of cesarean section. INTERVENTION(S): Transabdominal and transvaginal three-dimensional ultrasound examinations. MAIN OUTCOME MEASURE(S): The location of ET-associated air bubbles in the uterine cavity and the location of the resultant gestational sac. RESULT(S): Sixty ETs resulted in 22 pregnancies, and 32 gestational sacs were located. Twenty-six of the 32 embryos were within or between the area in which the catheter tip was situated and the area over which air bubbles had spread immediately after ET. CONCLUSION(S): In cases of pregnancy achieved through ET, approximately 80% of embryos implant in areas to which they initially are transferred and approximately 20% implant in other areas.

Adult↗
PubMed2000

Ocular histopathologic study of a patient with the T 8993-G point mutation in Leigh's syndrome.

OBJECTIVE: To report the histopathologic findings of eyes from a patient with Leigh's syndrome associated with the T 8993-G point mutation in mitochondrial DNA (mtDNA). DESIGN: Case report. INTERVENTION: A child with hypotonia, developmental delay, persistent lactic acidosis, seizures, and ataxia died of aspiration pneumonia at 15 months of age. Analysis of DNA isolated from blood was positive for the T to G point mutation at position 8993 in mtDNA, and the proportion of mutant genomes was estimated at approximately 95%. The type and distribution of abnormalities seen in the brain at autopsy were consistent with those in patients with Leigh's syndrome. MAIN OUTCOME MEASURES: The left eye was examined by light microscopy, and segments of the right eye were examined by transmission electron microscopy. Genetic analysis on DNA isolated from blood was performed. RESULTS: Thinning of the nerve fiber and ganglion cell layers was present in the nasal aspect of the macula, and mild atrophy of the temporal aspect of the optic nerve head and optic nerve was present. Electron microscopic study disclosed numerous distended mitochondria in all cells, but particularly in the retinal pigment epithelium, nonpigmented ciliary epithelium, and corneal endothelium. CONCLUSION: This is a report of the ocular histopathologic findings in Leigh's syndrome with the T 8993-G point mutation. The light microscopic findings were similar to those of patients with similar features reported previously. In addition, ultrastructural abnormalities of mitochondria were present.

Ciliary Body↗
PubMed2000

Cardiopulmonary cerebral resuscitation using emergency cardiopulmonary bypass, coronary reperfusion therapy and mild hypothermia in patients with cardiac arrest outside the hospital.

OBJECTIVES: The purpose of this study was to evaluate the efficacy of an alternative cardiopulmonary cerebral resuscitation (CPCR) using emergency cardiopulmonary bypass (CPB), coronary reperfusion therapy and mild hypothermia. BACKGROUND: Good recovery of patients with out-of-hospital cardiac arrest is still inadequate. An alternative therapeutic method for patients who do not respond to conventional CPCR is required. METHODS: A prospective preliminary study was performed in 50 patients with out-of-hospital cardiac arrest meeting the inclusion criteria. Patients were treated with standard CPCR and, if there was no response, by emergency CPB plus intra-aortic balloon pumping. Immediate coronary angiography for coronary reperfusion therapy was performed in patients with suspected acute coronary syndrome. Subsequently, in patients with systolic blood pressure above 90 mm Hg and Glasgow coma scale score of 3 to 5, mild hypothermia (34 C for at least two days) was induced by coil cooling. Neurologic outcome was assessed by cerebral performance categories at hospital discharge. RESULTS: Thirty-six of the 50 patients were treated with emergency CPB, and 30 of 39 patients who underwent angiography suffered acute coronary artery occlusion. Return of spontaneous circulation and successful coronary reperfusion were achieved in 92% and 87%, respectively. Mild hypothermia could be induced in 23 patients, and 12 (52%) of them showed good recovery. Factors related to a good recovery were cardiac index in hypothermia and the presence of serious complications with hypothermia or CPB. CONCLUSIONS: The alternative CPCR demonstrated an improvement in the incidence of good recovery. Based upon these findings, randomized studies of this hypothermia are needed.

Adolescent↗
PubMed2000

Isolation of a thermophile degrading poly(butylene succinate-co-butylene adipate).

A thermophile, strain 73, which degrades poly(butylene succinate-co-butylene adipate) (PBSA) film was isolated from 95 soil samples obtained from different locations by cultivation using an enrichment culture technique at 60 degrees C. At this temperature, the strain grew on PBSA and the dissolved total organic carbon (TOC) concentration in the medium changed according to the growth stage, i.e., after the TOC concentration rapidly reached the minimum, it increased rapidly until it reached a peak and then decreased thereafter. During cultivation, PBSA was almost eliminated and the solution viscosity of the residual PBSA decreased markedly. Gel permeation chromatograms of the residual PBSA showed a significant decrease in the main peak and the appearance of a new peak at the low molecular weight region. The strain was identified as Bacillus stearothermophilus, which has an optimum growth temperature of approximately 63 degrees C.

Journal Article↗
PubMed2000

Purification and characterization of polyphenol oxidase from banana (Musa sapientum L.) pulp.

Polyphenol oxidase (EC 1.10.3.1, PPO) in the pulp of banana (Musa sapientum L.) was purified to 636-fold with a recovery of 3.0%, using dopamine as substrate. The purified enzyme exhibited a clear single band on polyacrylamide gel electrophoresis (PAGE) and sodium dodecyl sulfate (SDS)-PAGE. The molecular weight of the enzyme was estimated to be about 41000 and 42000 by gel filtration and SDS-PAGE, respectively. The enzyme quickly oxidized dopamine, and its K(m) value for dopamine was 2.8 mM. The optimum pH was at 6.5, and the enzyme activity was stable in the range of pH 5-11 at 5 degrees C for 48 h. The enzyme had an optimum temperature of 30 degrees C and was stable even after a heat treatment at 70 degrees C for 30 min. The enzyme activity was completely inhibited by L-ascorbic acid, cysteine, sodium diethyldithiocarbamate, and potassium cyanide. Under a low buffer capacity, the enzyme was also strongly inhibited by citric acid and acetic acid at 10 mM.

Catechol Oxidase↗
PubMed2000

A prospective study of interferon therapy modified by pre-treatment viral load in cirrhotic patients. Tokyo-Chiba Hepatitis Research Group.

BACKGROUND/AIMS: The relative role of hepatitis C virus (HCV) load and subtype as predictors of the efficacy of interferon therapy has been clarified in patients with chronic hepatitis C, but the effectiveness of interferon therapy in cirrhotic patients is still unclear. METHODS: To resolve this issue, we undertook a multicenter, randomized, and prospective study of 114 cirrhotic patients with hepatitis C virus infection. The patients were selected to undergo two different periods (6 or 12 months) of IFN therapy according to viral load. Patients with "low" viral load (< or = 10(5.8) copies/ml serum) were randomly divided into three groups, receiving 6 or 9 million units (MU) interferon three times a week for 6 months (total dose: 468 or 702 MU), or of a modified regimen using 6MU of IFN over 6 months (total dose 564 MU), while patients with "high" viral load (< or = 10(6.3) copies/ml serum) were also randomly divided into two groups of 6 or 9 MU of IFN three times a week for 12 months (total dose: 936 or 1,404 MU). RESULTS: HCV-RNA negativity rate at the completion of treatment with 6 or 9 MU IFN was 65% in patients with "low" viral load, in contrast to 14% in patients with "high" viral load. Sustained virological response was found in 40% of patients with "low" viral load irrespective of the three different regimens, in contrast to only 1 out of 35 patients (3%) with "high" viral load. Viral eradication was found in approximately 50% of patients having a low virus load (< or = 10(4.3) copies/ml) and with HCV subtype 2a. Univariate and multivariate analysis revealed that pretreatment viral load was a significant factor contributing to efficacy of IFN therapy. CONCLUSIONS: Sustained response was scarcely achieved in cirrhotic patients with high viral loads even after a 12-month course of intensive IFN therapy. This result indicates that there is a certain cut-off level of HCV RNA load which can not be eradicated.

Adult↗
PubMed2000

A novel strategy for cancer therapy by mutated mammalian degenerin gene transfer.

Mammalian degenerin (MDEG) is a member of the amiloride-sensitive sodium ion channel family, and its site-directed active mutant (MDEG-G430F) induces massive Na+ influx into cells, leading to cell ballooning and cell bursting. We attempted a novel therapeutic approach for gastric cancers by transferring MDEG-G430F into cancer cells using tumor-specific promoters. In carcinoembryonic antigen (CEA)-producing gastric cancer cells, the level of cell death observed when MDEG-G430F was used with a CEA promoter was similar to that observed when using a potent nonspecific promoter such as the cytomegalovirus promoter. In an in vivo study, fusogenic liposome complexes containing MDEG-G430F driven by the CEA promoter were injected intraperitoneally into CEA-producing gastric cancer cells in a mouse peritoneal dissemination model. Although all 15 of the control mice were dead by 50 days postinoculation, 13 of the 15 mice treated with MDEG-G430F survived. These results indicate that transferring MDEG-G430F into cancer tissues using tumor-specific promoters can achieve striking and selective cancer cell death irrespective of the transcriptional efficiency of the promoters used in vivo, and suggest that this approach is a promising new strategy for cancer gene therapy.

Acid Sensing Ion Channels↗
PubMed2000

Common antigenicity between Japanese cedar (Cryptomeria japonica) pollen and Japanese cypress (Chamaecyparis obtusa) pollen, I. H-2 complex affects cross responsiveness to Cry j 1 and Cha o 1 at the T- and B-cell level in mice.

Common antigenicity among two purified Japanese cedar pollen allergens (Cry j 1 and Cry j 2) and one Japanese cypress pollen allergen (Cha o 1) was explored at the T-cell and B-cell level in mice of different H-2 haplotypes. Cry j 2 did not show any common antigenicity with Cry j 1 or Cha o 1. B10.S (H-2S) mice immunized with Cry j 1 or Cha o 1 generated T cells and antibodies reactive to both antigens, indicating the common antigenicity of these antigens. C57BL/6 (H-2b) mice were non-responders to Cry j 1. BALB/c (H-2d) mice immunized with Cry j 1 or Cha o 1 and C57BL/6 mice immunized with Cha o 1 generated T cells that were only reactive with the respective immunogen, but produced antibody reactive to both Cry j 1 and Cha o 1, indicating that Cry j 1 and Cha o 1 share their B-cell epitope but not their T-cell epitope. This finding may provide a clue for the clarification of the T-cell and B-cell epitopes of Cry j 1 and Cha o 1, even though the data are influenced by H-2 complex restriction in mice. Considering that H-2 complex restriction affects cross responsiveness to Cry j 1 and Cha o 1 at the T- and B-cell level in mice, we assessed the possible situation in humans exposed sequentially to Japanese cedar pollen and Japanese cypress pollen.

Allergens↗
PubMed2000

Molecular analysis of hepatitis D virus infection in Miyako Island, a small Japanese island.

The present investigation attempted to determine the exact prevalence of hepatitis D virus (HDV) infection among inhabitants of Miyako Island (a remote island in the Okinawa Prefecture) and the molecular characteristics of the HDV genome that was isolated. Among the 4728 inhabitants, 375 (7.9%) were hepatitis B surface antigen (HBsAg) positive. Antibody to HDV (anti-HDV) was present in 32 (8. 5%) of these 375 subjects, and liver function tests were normal in most subjects. The presence of HDV RNA was analysed by nested polymerase chain reaction (PCR). Thirteen out of the 32 anti-HDV antibody-positive subjects were HDV RNA positive. Thus, 3.5% of HBsAg-positive subjects on Miyako Island were HDV RNA positive. Among the HDV RNA-positive subjects, liver function tests were within normal limits or were mildly abnormal. Nucleotide sequence analysis revealed that the HDV genomes on Miyako Island were similar to the Japanese and Taiwan isolates of HDV genotype II. Taiwan is geographically close to Miyako Island. Even though the races are different, a geographical factor was revealed to be significant with regard to HDV infection, which was spread in a closed environment.

Aged↗
PubMed2000

Clinical characteristics of patients with chronic hepatitis C showing biochemical remission, without hepatitis C virus eradication, as a result of interferon therapy. The Osaka Liver Disease Study Group.

During long-term follow-up of patients chronically infected with the hepatitis C virus (HCV) and treated with interferon (IFN), we identified some who had persistent normalization of serum alanine aminotransferase (ALT) but remained positive for HCV RNA. The aims of this study were to clarify the characteristics of these patients and to examine their clinical outcome after treatment. Nine hundred and ninety-eight patients treated with IFN were followed-up biochemically and virologically, and by liver ultrasound, for 13-95 months. A short-term biochemical sustained response, where ALT remained within the normal range for 6 months after the completion of IFN therapy, was found in 296 patients; in 240 of these patients serum HCV RNA remained undetectable during long-term follow-up. The rate of HCV RNA persistence was 7.09 times greater in short-term biochemical sustained responders with a high viral load than in those with a low viral load (P=0.0001, odds ratio [OR]=7.09), and 3. 70-fold lower in those treated with a large dose of IFN than in those treated with a small dose (P=0.02, OR=0.27). Thirty-three (59%) of 56 patients without HCV eradication showed continuous ALT normalization for 26-80 months after cessation of IFN therapy. Short-term biochemical sustained responders who were older (P=0.009, OR=10.43) and who were male (P=0.03, OR=6.98) had a significantly greater probability of maintaining a normal ALT level, even when serum HCV RNA was positive. When the incidence of HCC was investigated during long-term follow-up in patients without HCV eradication, it was found to be significantly lower in patients with persistently normal ALT levels than in those with abnormal ALT levels (P=0.03). Hence, when HCV is not eradicated as a result of IFN therapy, it may induce a long-term carrier state of HCV infection with normal ALT levels in older or male patients, in whom the cumulative incidence of HCC is markedly decreased.

Adult↗
PubMed2000

Surgery for gastric carcinoma in patients more than 85 years of age.

BACKGROUND: The incidence of gastric carcinoma is increasing in elderly patients. It has not been determined whether surgery improves the quality of life or prolongs survival in patients older than 85 years. This study was designed to evaluate surgery as a treatment option in patients more than 85 years of age. METHODS: The records of 18 patients aged 85 to 91 years (mean 87.3 years), who underwent surgery for gastric carcinoma between 1983 and 1997 were analysed. RESULTS: Three patients had multiple lesions. A total of 21 lesions were examined. Operative procedures included distal gastrectomy (n = 12), total gastrectomy (n = 4), proximal gastrectomy (n = 1), and laparoscopic wedge resection (n = 1). Perigastric lymphadenectomy was performed in 15 patients. No lymph node dissection was performed in three patients. Postoperative complications, including delirium, respiratory dysfunction, cardiac dysfunction, anastomotic leakage, bleeding, and ileus, occurred in 11 patients. There were two hospital deaths in patients who underwent emergency surgery. Survival was neither shortened nor prolonged by surgery as determined by life table analysis. CONCLUSIONS: Surgical treatment should not be avoided based solely on the age of the patient, and quality of life in this population may be improved by surgery. Careful patient selection should include an assessment of the will to live.

Adenocarcinoma↗
PubMed2000

A new staging criterion for bladder carcinoma using gadolinium-enhanced magnetic resonance imaging with an endorectal surface coil: a comparison with ultrasonography.

OBJECTIVE: To evaluate the accuracy of a new staging criterion, submucosal linear enhancement (SLE) on gadolinium-diethylenetriamine-pentaacetic acid-enhanced T1-weighted magnetic resonance imaging (MRI) using an endorectal surface coil (endorectal enhanced MRI), and to compare the accuracy of this method with that of transurethral ultrasonography (TUUS). PATIENTS AND METHODS: The study included 71 patients with bladder tumours (63 men and eight women, mean age 65.5 years, range 31-85). The SLE coincided with abundant submucosal vascular beds, as reported in a previous study. When the SLE beneath the tumour maintained continuity, the tumour was diagnosed as superficial (</= T1), but if the SLE was interrupted by the tumour, the disease was considered invasive (>/= T2a). Superficial muscle invasion (less than half the muscle layer) and deep muscle invasion (more than half the muscle layer) were classified as T2a and T2b, respectively. When the tumour formed an extravesical mass, the tumour was classified as T3b. RESULTS: The staging accuracy for bladder tumours using SLE on endorectal-enhanced MRI or TUUS was 83% and 60%, respectively (P < 0.01). Using the SLE, muscle invasion of bladder tumour was diagnosed with an accuracy of 87%, a sensitivity of 91% and a specificity of 87%; this was significantly better than with TUUS (P < 0.01). CONCLUSION: The criterion of SLE on Gd-DTPA enhanced T1-weighted MRI using an endorectal surface coil is useful for staging bladder tumour, and the staging accuracy is significantly better than with TUUS.

Adult↗