Biomedical subjects

S Kitamura

Publications and source records attributed to S Kitamura.

At least 109 records · Page 6Linked to original sources

PubMed2000

Reduction of hydroxamic acids to the corresponding amides catalyzed by rabbit blood.

1. The hydroxamic acids N-hydroxyphenacetin and N-hydroxy-2-acetylaminofluorene were reduced to the corresponding amides, phenacetin and 2-acetylaminofluorene respectively by rabbit blood supplemented with both NAD(P)H and FAD. These reducing activities were found in erythrocytes but not in plasma, and were sensitive to inhibition by carbon monoxide and oxygen. When blood or erythrocytes were boiled, these activities were not abolished. 2. Haemoproteins such as haemoglobin and catalase exhibited the reductase activity in the presence of both NAD(P)H and FAD under anaerobic conditions. The activity was not abolished when the haemoproteins were boiled. 3. Haematin showed a significant reducing activity in the presence of these cofactors. The activity of haematin was also observed with the photochemically reduced form of FAD. 4. The reduction system in blood was composed of NAD(P)H, FAD and haemoglobin. Reduction appears to proceed in two steps, i.e. the reduction of FAD by NADH or NADPH, followed by the non-enzymatic reduction of the hydroxamic acids to the amides by reduced FAD, catalyzed by the haem group of haemoglobin in rabbit erythrocytes.

2-Acetylaminofluorene↗

PubMed2000

Reduction of stilbene oxide and styrene oxide to the corresponding alkenes by intestinal bacteria.

1. This study provides the first evidence that stilbene oxide and styrene oxide are reductively metabolized to the corresponding alkenes by intestinal bacteria in animals. 2. When trans- or cis-stilbene oxide were incubated with the caecal contents of rat under anaerobic conditions, both trans- and cis-stilbene were isolated from the incubation mixture. Styrene oxide was also reduced to styrene by rat caecal contents. 3. Caecal contents of mouse, hamster and guinea pig also exhibited alkene oxide reductase activities toward cis- and trans-stilbene oxides, and styrene oxide. In contrast, liver microsomes or cytosol exhibited no epoxide reductase activities toward these substrates. 4. Seven pure strains of intestinal bacteria exhibited alkene oxide reductase activities of varying degrees under anaerobic conditions, with the highest activity being observed in Clostridium sporogenes. 5. Cell-free extracts of either the intestinal bacteria in rat caecal contents or C. sporogenes exhibited reductase activity when supplemented with both NAD(P)H and FMN under anaerobic conditions. Reductase activity was also observed on addition of the photochemically reduced form of FMN instead of both NAD(P)H and FMN.

Animals↗

PubMed2000

Highly substituted glucuronoarabinoxylans (hsGAXs) and low-branched xylans show a distinct localization pattern in the tissues of Zea mays L.

Polyclonal antibodies which recognized highly substituted glucuronoarabinoxylans (hsGAXs) and low-branched xylans and did not cross-react with each other, were raised in order to examine localization of these epitopes in internodes of maize. Immunofluorescent labeling revealed different pattern between two succeeding developmental stages. The hsGAX epitope was localized evenly in primary walls in all tissue types, and strongly in unlignified secondary walls in phloem. However, lignified secondary walls in protoxylem, parenchyma and a part of fibers were faintly labeled with this epitope. Moreover, the epitope showed limited binding in lignified parenchyma and fiber walls at ultrastructural level. Low-branched xylan epitope was localized evenly throughout lignified walls in all tissue types. This epitope was also localized only in lignified walls of other organs such as leaf, root apex and dark-grown mesocotyl. Low-branched xylans are significantly related to lignification. Localization of hsGAX epitope in their organs was similar to that in internodes. The hsGAX epitope was distributed both in unlignified walls of all tissues and in lignified walls of parenchyma and annular thickening of protoxylem. We propose that hsGAX has separate functions in lignified and unlignified tissues. In conclusion, at tissue level, hsGAX is localized mainly in unlignified walls, and low-branched xylans in lignified walls.

Antibody Specificity↗

PubMed2000

Development of a novel enzyme-linked immunosorbent assay for blood and urinary eosinophil-derived neurotoxin: a preliminary study in patients with bronchial asthma.

BACKGROUND: Eosinophil-derived neurotoxin (EDN), also called eosinophil protein X (EPX), has been suggested to be a useful marker of eosinophilic inflammation. However, no commercial enzyme-linked immunosorbent assay (ELISA) kit for EDN is available yet. METHODS: EDN was purified from pooled urine from healthy male volunteers. Polyclonal and monoclonal anti-EDN antibodies were subsequently raised, and a sandwich ELISA for EDN was established. EDN levels in serum, plasma and urine from asymptomatic patients with bronchial asthma were measured by the ELISA method. Some of the blood samples were also measured by a commercial radioimmunoassay (RIA) kit. RESULTS: The ELISA method detected human EDN with a minimum detection limit of less than 0.62 ng/ml and did not cross-react with other eosinophil granule cationic proteins including eosinophil cationic protein. The intra- and interassay coefficients of variation of the ELISA method ranged from 2.6 to 3.6% and from 6.5 to 9.4%, respectively. Good linearity was observed with serially diluted different samples, and the recoveries of the purified EDN added to serum samples ranged from 85 to 110%. Median EDN concentrations in serum (36.9 vs. 19.1 ng/ml), plasma (23.0 vs. 14.5 ng/ml) and urine (118.2 vs. 72.1 microg/mmol Cr) were significantly raised in asymptomatic asthmatic patients compared with healthy control subjects. EDN levels in serum, plasma and urine from the patients significantly correlated with the number of peripheral blood eosinophils, but not total serum IgE levels. A significant relationship between EDN values measured by the EPX-RIA kit and the EDN-ELISA method was observed. CONCLUSIONS: We have developed a novel efficient ELISA method to specifically measure blood and urinary EDN, which may be useful to study the role of eosinophils in allergic diseases including bronchial asthma.

Asthma↗

PubMed2000

Concurrence of sarcoidosis and lung cancer. A report of four cases.

Although sarcoidosis and lung cancer are both frequently encountered conditions, their simultaneous occurrence in the same patient is unusual. In this report, we describe 4 cases of their concurrence and discuss the possible pathogenic mechanisms of their concurrent appearance. In particular, in 2 of the cases, both diseases had coexisted for a long period (more than 6 and 4 years, respectively), showing a surprisingly slow growth of cancers. Although the chest computed tomography showed hilar and mediastinal lymphadenopathy, the histopathological findings of the excised lymph nodes of both cases revealed no metastasis. The causal relationship between sarcoidosis and lung cancer remains uncertain, but cases such as these may be helpful in elucidating its precise nature.

Adenocarcinoma↗

PubMed2000

Aerosolized administration of N-acetylcysteine attenuates lung fibrosis induced by bleomycin in mice.

Reactive oxygen species (ROS) play an important role in the pathogenesis of pulmonary fibrosis. We previously demonstrated that N-acetylcysteine (NAC), an antioxidant, inhibited adhesion molecule expression and cytokine production in lung cells. When NAC is inhaled into the alveolar space, it is expected to directly interact with inflammatory cells and to elevate glutathione levels in the epithelial lining fluids. We therefore examined whether inhaled NAC inhibits lung fibrosis induced by bleomycin (BLM). Male ICR mice were given a single intravenous injection of BLM (150 mg/ kg). Thirty milliliters of NAC (70 mg/ml) or saline were inhaled twice a day for 28 d using an ultrasonic nebulizer. In the inflammatory phase (Day 7), NAC administration attenuated the cellular infiltration in both bronchoalveolar lavage fluid (BALF) and alveolar tissues. At Day 28, the fibrotic changes estimated by Aschroft's criteria and hydroxyproline content in the NAC inhalation group were significantly decreased compared with the BLM-only group (p < 0.05). CXC chemokines, macrophage inflammatory protein-2 (MIP-2), cytokine-induced neutrophil chemoattractant (KC), and CC chemokines, macrophage inflammatory protein-1alpha (MIP-1alpha), in BALF were mostly elevated on Day 7 in the BLM-only group; however, these elevations were significantly repressed by NAC inhalation (p < 0.05). Lipid hydroperoxide (LPO) was also quantified in BALF. LPO was markedly increased on Day 3 in the BLM-only group, and this increase was significantly decreased by NAC inhalation (p < 0.05). These results revealed that aerosolized NAC ameliorated acute pulmonary inflammation induced by BLM injection via the repression of chemokines and LPO production, resulting in the attenuation of subsequent lung fibrosis. These findings are limited to the BLM-induced lung fibrosis animal model. However, NAC inhalation will be expected to be a potential therapy for patients with other interstitial pneumonias because ROS are involved in the pathogenesis of lung injury in most interstitial pneumonia.

Acetylcysteine↗

PubMed2000

Reductive metabolism of stilbene oxide and styrene oxide to the olefins in rats.

The present study provides the first evidence that stilbene oxide and styrene oxide are reductively metabolized to the corresponding olefins in rats. When cis- or trans-stilbene oxide was given orally to rats, both cis- and trans-stilbene were isolated from the urine and feces. Styrene was also isolated from the urine and feces of rats given styrene oxide. These metabolites were identified unequivocally by UV and mass spectral comparison with authentic samples, and on the basis of their TLC and HPLC behavior. However, these olefins were not detected in the urine or feces of antibiotics-treated rats dosed with cis- or trans-stilbene oxide. Cecal contents of the untreated rats exhibited olefin oxide reductase activities toward cis- and trans-stilbene oxides under anaerobic conditions. The results suggest that intestinal bacteria play an important role in the reduction of olefin oxides to the corresponding olefins in the animal body.

Alkenes↗

PubMed2000

Pulmonary ventricular outflow reconstruction with a size-reduced cryopreserved pulmonary valve allograft: mid-term follow-up.

Surgical reduction of pulmonary allografts is being performed because of the shortage of allografts of suitable size for pediatric use. However, the outcome of size-reduced pulmonary allografts for pulmonary conduits is unknown. In the present study, cryopreserved pulmonary allografts harvested from adults at the time of kidney donation were size-reduced and used in 4 children, 2 with pulmonary atresia and ventricular septal defect and 2 with atrioventricular discordance, pulmonary atresia and ventricular septal defect. They all had undergone right and/or left modified Blalock-Taussig shunt operations with a 5-mm synthetic graft prior to the reparative operations. They underwent definitive repair with a size-reduced cryopreserved pulmonary allograft valved conduit and were followed up for 2-5 years. Postoperative echocardiographic and cineangiographic assessments revealed excellent function of the pulmonary bicuspidalized valves with a minimal pressure gradient and no, or only trivial, regurgitation. Although the long-term result of a cryopreserved bicuspid pulmonary valved conduit remains unknown, the remodeled bicuspid pulmonary allograft conduits showed excellent hemodynamic characteristics in mid-term follow-up and appear to be a reasonable alternative to other types of conduits when an appropriate-sized allograft is not available.

Adult↗

PubMed2000

Oozing type cardiac rupture repaired with percutaneous injection of fibrin-glue into the pericardial space: case report.

Two patients, a 56-year-old man and an 81-year-old woman who were admitted to hospital because of anteroseptal acute myocardial infarction, were initially treated successfully with direct percutaneous transluminal coronary angioplasty. However, both patients later developed sudden cardiogenic shock due to cardiac tamponade caused by left ventricular free wall rupture (LVFWR). Prompt, life-saving pericardiocentesis was performed, then fibrin-glue was percutaneously injected into the pericardial space. After the procedure, there was no detectable pericardial effusion on echocardiography and the hemodynamic state became stable. The surgical treatment was the standard procedure for LVFWR, but percutaneous fibrin-glue therapy can also be considered for oozing type LVFWR.

Aged↗

PubMed2000

Cardiac transplantation under new legislation for organ transplantation in Japan: report of two cases.

During the past 2 years since new legislation for organ transplantation from brain-dead donors came into effect in Japan, 3 cardiac transplants have been carried out, 2 of which were performed at the National Cardiovascular Center (NCVC). The recipient cases were 46- and 25-year-old male patients who suffered from end-stage dilated cardiomyopathy and had been listed for cardiac transplantation in the Japan Organ Transplantation Network as status I candidates. The first patient was supported by the use of a paracorporeal air-driven left ventricular assist device of the NCVC type, and had a moderate degree of renal and hepatic dysfunction at the time of transplantation. Donor hearts were transported from distant hospitals (Tokyo and Miyagi prefecture) and the transportation time was 1 h 33 min and 2h 4 min, respectively. The operation was performed by the standard technique (Lower-Shumway) in the first patient and by the bicaval anastomosis technique in the second patient. Reperfusion of the transplanted heart was performed retrogradely through the coronary sinus utilizing leukocyte-depleted blood with a gradual increase in temperature. Total ischemic time was 3 h 34 min and 3 h 35 min, respectively. Weaning from the cardiopulmonary bypass was easy and uneventful in each patient. Immunosuppressive therapy was conducted with OKT-3 induction in the first patient because of the coexisting renal dysfunction and with a triple immunosuppressive regimen for both patients. Routine endomyocardial biopsy showed acute rejection of less than grade Ib, and the patients were discharged on the 65th and 46th postoperative day, respectively. At present, both patients are in the NYHA class I state and are ready to return to work. The uneventful recovery seen in these patients shows the advances made in transplant medicine, including the progress and improvement of immunosuppressive therapy, surgical techniques, myocardial protection, and detection and treatment of infection. Further efforts are required to fully establish the cardiac transplantation program in Japan.

Adult↗

PubMed2000

Septic arthritis of the hip associated with atopic dermatitis. A case report.

We report a case of septic arthritis of the hip associated with atopic dermatitis. A 15-year female felt a pain in the right hip with unknown cause on May 11, 1998. The pain subsequently became aggravated, and she was admitted to our hospital on May 18. She has had atopic dermatitis since 4 years of age. She showed generalized dermatitis with desquamation and numerous scratch marks. A culture of both skin and joint fluid revealed Staphylococcus aureus. Physical examination revealed tenderness in Scarpa triangle and restricted range of motion. Immunological serology showed an increase in eosinophils and immunoglobulin E, and a decreased reaction of lymphocyte blastoid transformation. Computed tomography (CT) and MRI showed a joint effusion in the right hip. She was diagnosed as having septic arthritis of the hip. Intravenous drip of Cefazolin of 2g was started on the first day of hospitalization and joint irrigation was done on the second day. CRP became negative at 4 weeks, but joint effusion was shown on CT. Additional joint irrigation with Amicamycin (200 mg) was done. As the joint fluid culture became negative, range of motion exercises were started at 6 weeks. She was discharged with a long-leg brace applied at 8 weeks. At 13 months after onset, she had complete relief of the pain and normal activities of daily living. No destructive changes in the hip were found on X-ray examination or MRI. In the present case, an abnormal immune system associated with atopic dermatitis as well as the habit of scratching eruptions may have led to hematogenous spread of skin infection, and caused septic arthritis of the hip.

Adolescent↗

PubMed2000

High fever, renal failure, disseminated intravascular coagulation and myelodysplasia accompanied with enhanced angiogenesis possibly due to overexpression of vascular endothelial growth factor.

A 44-year-old woman suffered from recurrent fever, edema and fatigue. Laboratory data revealed renal dysfunction, low proteinemia, disseminated intravascular coagulation (DIC) and myelodysplasia. A renal and lymph node biopsy showed a marked angiogenesis. Serum levels of vascular endothelial growth factor (VEGF), and interleukin (IL)-6 were markedly increased, suggesting a pathogenesis related to VEGF-induced angiogenesis. The symptoms were remitted after treatment with cyclosporin A. No evidence of solid tumors, malignant lymphoma, Castleman's disease or POEMS (polyneuropathy, organomegaly, endocrine disorder, M-proteinemia and skin change) syndrome, reported to induce a high serum VEGF level, was obtained. This case may have involved an unknown mechanism which induced an overexpression of VEGF and IL-6.

Adult↗

PubMed2000

Trisomy 10 as the sole abnormality in biphenotypic leukemia.

We observed a case of acute biphenotypic leukemia with trisomy 10 as the sole abnormality. The patient was an adult male diagnosed with ALL(L2), Cell marker studies showed positivity for CD3, CD7, CD13 and CD33, so the phenotypic diagnosis was determined to be biphenotypic leukemia. No case of biphenotypic leukemia with trisomy 10 has been previously reported, until now.

Chromosomes, Human, Pair 10↗

PubMed2000

[Endoscopic approach to pulmonary diseases: Clinical utility of medical thoracoscopy in diagnosis of pleural diseases].

Thoracoscopy is useful for diagnosis of a number of lung diseases. We report our recent experience of medical thoracoscopy performed under local anesthesia in 142 cases. Of 124 patients with pleural effusion, 46 had pleuritis carcinomatosa, 11 had pleuritis tuberculosa, and 10 had malignant mesothelioma. We evaluated the utility of thoracoscopic observation and pleural biopsy in these three diseases. Almost of patients with malignant pleural effusion initially undiagnosed by the cytology of pleural effusion were diagnosed by thoracoscopy. Especially in malignant mesothelioma, thoracoscopy allowed accurate diagnosis. No serious complication was observed. Since medical thoracoscopy under local anesthesia is a rapid, easy, safe, and well-tolerated procedure with an excellent diagnostic yield, it is recommended as a diagnostic procedure for cases with pleural effusion.

Adult↗

PubMed2000

[Hospitalization reduction by an asthma tele-medicine system].

We examined an effectiveness of a new asthma telemedicine system in reducing hospitalizations using a multi-site randomized control study. In this program, a nurse under physician supervision monitors the patient's airway status at home and provides instructions to individuals via the telephone, helping them manage exacerbations as well as reinforcing proper use of a zone-controlled management plan. Patients with a high risk for hospitalization were screened based on the numbers of emergency room visits and hospitalizations found in a previous study and randomly assigned to either the telemedicine or control group. After a six-month study period, an 83% reduction in hospitalization was demonstrated in the telemedicine group versus the control group, with a P value of 0.01. Improvement of peak expiratory flow and symptoms were also shown in the study group. We conclude that the key success factors in home asthma management for poorly controlled asthma patients are early detection of exacerbations through daily peak flow monitoring, compliance with prescribed daily prophylactic anti-inflammatory steroid medications, and immediate action as specified by a zone-controlled action plan upon the first signs of deterioration.

Aged↗

PubMed2000

Semi-automatic ROI placement system for analysis of brain PET images based on elastic model: application to diagnosis of Alzheimer's disease.

UNLABELLED: PET with 18F-fluorodeoxyglucose (FDG) is a useful technique to image cerebral glucose metabolism and to detect patients with Alzheimer's disease in the early stage, in which characteristic temporoparietal hypometabolism is visualized. We have developed a new system, in which the standard brain ROI atlas made of networks of segments is elastically transformed to match the subject brain images, so that standard ROIs defined on the segments are placed on the individual brain images and are used to measure radioactivity over each brain region. We applied this methods to Alzheimer's disease. METHODS: This method was applied to the images of 10 normal subjects (ages 55 +/- 12) and 21 patient clinically diagnosed as Alzheimer's disease (age 61 +/- 10). The FDG uptake reflecting glucose metabolism was evaluated with SUV, i.e. decay corrected radioactivity divided by injected dose per body weight in (Bq/ml)/(Bq/g). RESULTS: The system worked all right in every subject including those with extensive hypometabolism. Alzheimer patients showed markedly lower in the parietal cortex (4.0-4.1). When the threshold value of FDG uptake in the parietal lobe was set as 5(Bq/ml)/(Bq/g), we could discriminate the patients with Alzheimer's disease from the normal subjects. The sensitivity was 86% and the specificity was 90%. CONCLUSIONS: This system can assist diagnosis of FDG images and may be useful for treating data of a large number of subjects; e.g. when PET is applied to health screening.

Adult↗

PubMed2000

Benzodiazepine receptor distribution and cerebral blood flow in early blindness--a PET study.

We studied benzodiazepine receptor (BZR) distribution, which is thought to be affected by neuronal density in the cerebral cortex, and CBF using [11C]flumazenil and [15O]water PET in early blind (EB) and in blindfold sighted control (SC) subjects. PET images were co-registered to the subject's MRI. Using SPM96, MRI images were normalized in the Talairach and Tournoux coordinate system, and accordingly MRI-registered PET images were spatially normalized. Statistical parametric maps were computed on a voxel-by-voxel basis, using the general linear model. CBF for EB was significantly larger in the Brodmann area 17 and 18, especially anterior area, than that for SC, while there was no significant difference in BZR distribution. Our BZR data suggest that the amount of neurons do not change due to early visual deprivation in the visual cortex, in spite of high CBF in visual cortex of EB subjects.

Adult↗

PubMed2000

[An experience with the Ross operation utilizing cryopreserved pulmonary homografts procured by and stored in our homograft valve bank].

Eight patients, 4 males and 4 females ranging in age from 10 to 54 years (mean 27 +/- 13 years) underwent the Ross operation using a cryopreserved pulmonary homograft harvested by and cryopreserved in our institutional "Tissue Bank". Seven patients had a congenital bicuspid aortic valve and 3 patients had had healed infective endocarditis of the aortic valve. Four young female patients wanted to have a baby after operation. The Ross procedure was carried out utilizing aortic root replacement techniques in all patients. All patients survived and are currently in NYHA class 1, but 2 cardiac events occurred in 2 patients during the mean follow-up term of 29 +/- 19 months. The one was the anastomic stenosis between the homograft and distal pulmonary artery treated by balloon dilatation and the other was ventricular tachycardia eventually managed by the insertion of an ICD. Pulmonary autograft valve regurgitation is present in 3 patients, but it is not progressive up to the present time. Pulmonary homograft valves function well in all patients. The Ross operation for adolescents and young adults should become more popular along with more easy availability of homograft valves based upon the establishment of the "Homograft Valve Bank" system in Japan.

Adolescent↗