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M Kobayashi

Publications and source records attributed to M Kobayashi.

At least 145 records · Page 8Linked to original sources
PubMed2002

Influence of lactococcal plasmid on the specific growth rate of host cells.

AIMS: To investigate a lactococcal plasmid responsible for a reduction in growth rate of its host cell. METHODS AND RESULTS: Lactococcus lactis subsp. lactis biovar. diacetylactis DRC1 carries a high number of plasmids. The DRC1 wild-type strain was found to grow more slowly than a plasmid-free derivative of DRC1. The plasmids extracted from DRC1 together with an indicator plasmid were cotransformed into the plasmid-free strain DRC1021. A 7.4-kb cryptic plasmid, designated pDR1-1, was found to significantly affect the maximum specific growth rate ( micro max) of the host cell. Polymerase chain reaction (PCR) analysis was carried out in order to detect the presence of pDR1-1 in the other L. lactis strains. The micro max of the single pDR1-1-positive strain was determined to be the same as that of DRC1. SIGNIFICANCE AND IMPACT OF THE STUDY: These results suggest that pDR1-1 (or a pDR1-1-like plasmid) is a critical factor in the reduction of the micro max of DRC1, and that its effect on the micro max is significantly greater than that of any other coexisting plasmid.

Fermentation↗
PubMed2002

Mobilization factors of peripheral blood stem cells in healthy donors.

As a source of hematopoietic stem cells for transplantation, the use of peripheral blood stem cells (PBSCs) has become routine and comparable to that of the use of bone marrow. Recently, elderly patients with hematological malignancies also have been allowed to receive minitransplantations with nonmyeloablative conditioning regimens under sufficient PBSC infusion. As a result of these minitransplantations, elderly donors have been chosen increasingly from the siblings of elderly patients. We analyzed factors influencing the condition of CD34+ cells in the first days of collection in 49 healthy donors from July 1995 to January 2001. The median dose of recombinant human granulocyte colony-stimulating factor was 8 microg/kg/day (range 8 - 10) over 3 days. The target number of CD34+ cells used in this study was > or = 3 x 10(6) cells/kg of recipient body weight. The median apheresis volume was 12 L. Except for one 60 year old man, we obtained an adequate number of stem cells. In the regression analysis, a negative correlation was seen between donor age and the number of CD34+ cells/kg of recipient body weight per 12 L volume (Y = aX + b; a = -0.07507; b = 6.629996; r = -0.50985; p = 0.000252). Significantly higher apheresis results were obtained in donors younger than 45 years compared with donors 45 years old and older (p < 0.0227). There were no correlations among the number of CD34+ cells, donor body weight, and the number of leukocytes in peripheral blood on the first day of apheresis.

Adolescent↗
PubMed2002

Finite element analysis of the stresses around endosseous implants in various reconstructed mandibular models.

PURPOSE: To calculate the location and intensity of the maximum stresses occurring around implants in the reconstructed mandible. MATERIAL AND METHODS: Human preserved mandibles and fibulae were used to design 3-D mandibular models on a Desktop Computer. Various 3-D simulation models representing mandibles were made. Implants (fixtures) and superstructures were then embedded in each model and occlusal pressure was applied to the cantilever portion of the superstructure. Von Mises stress, the maximum and minimum principal stress on each model were calculated using finite element structural analysis software. Finally, evaluation of the stresses around each fixture hole was performed. RESULTS: It appeared that for each fixture hole, the direction and the magnitude of the stresses were influenced by complex factors such as the thickness of the cortical bone where the fixtures were embedded, the degree of vertical displacement under load, and the relationship between adjacent fixtures. CONCLUSION: Location and intensity of the stresses occurring around fixtures differs significantly between various types of mandibular reconstruction. Published by Elsevier Science Ltd.

Bite Force↗
PubMed2002

alpha-Tocopherol Inhibits IL-8 synthesis induced by thrombin and high glucose in endothelial cells.

It has been reported that alpha-tocopherol, an antioxidant agent, may play a role in preventing diabetic angiopathy. However, there is little evidence to show the effect of alpha-tocopherol on the production of pro-inflammatory cytokines in endothelial cells. Therefore, we examined the effect of alpha-tocopherol on the regulation of IL-8 synthesis induced by high glucose and/or thrombin in endothelial cells. Thrombin alone markedly increased the IL-8 release. Furthermore, high glucose levels and thrombin combined had additive effects on IL-8 synthesis, and alpha-tocopherol diminished their effect; alpha-tocopherol also inhibited the phosphorylation of IkappaB-alpha induced by high glucose levels and/or thrombin. Our results suggest that the administration of alpha-tocopherol to diabetic patients may have a beneficial effect for the prevention of diabetic vascular complications by the inhibition of IL-8 synthesis from endothelial cells.

Aorta↗
PubMed2002

Superficial depressed-type cancer monitored by colonoscopy through the early phase of invasion.

Although previous retrospective reports have demonstrated the developmental course of several colorectal tumors, the natural history and progression of depressed carcinoma, especially in the early stage, remains obscure. We report a case of superficial depressed tumor in the transverse colon in a 71-year-old man, which did not change in size and gross configuration through prospective colonoscopic observation over a period of 19 months but which was finally diagnosed as early-stage submucosal invasive cancer. Most depressed cancers have been supposed to arise de novo and grow rapidly, showing aggressive behavior when 10 mm or less in size. However, this case report may suggest that even a depressed tumor may grow to approximately 10 mm within the mucosal layer over a few years and that the growth of colorectal tumors, whether they are polypoid or depressed in configuration, might be fairly slow.

Adenocarcinoma↗
PubMed2002

Influence of alcohol consumption on the association between serum lipids and colorectal adenomas.

BACKGROUND: There have been no reports that low serum cholesterol levels increase the risk of colorectal adenoma, although many studies have shown that they do increase the risk of colorectal cancer. Alcohol intake, which is associated with a risk of colorectal adenomas, and serum cholesterol levels are closely related. The purpose of this study was to evaluate the influence of alcohol consumption on the association between serum cholesterol levels and colorectal adenoma. METHODS: The subjects were 1,349 male patients who underwent both barium enema examination and total colonoscopy. They answered a questionnaire regarding their alcohol consumption history, and their blood samples were analysed. The subjects were divided into three groups: those with no tumour (with neither adenoma nor adenocarcinoma), those with adenoma and those with adenocarcinoma. Among the groups, the serum total cholesterol and triglyceride levels were compared in all the patients, in the patients who did not drink daily and in the patients who did. RESULTS: In all the patients, the serum cholesterol and triglyceride levels did not differ between the patients with and those without adenoma. In the daily drinkers, the serum cholesterol and triglyceride levels were significantly lower in patients with adenoma than in those without. CONCLUSIONS: Significantly lower levels of serum cholesterol and triglycerides were found in daily drinkers with adenoma than in those without.

Adenocarcinoma↗
PubMed2002

Characteristics of mastication in the anodontic mouse.

Teeth and periodontal mechanoreceptors play important roles in regulating jaw movements during mastication. However, little is known concerning how jaw movements develop without tooth eruption. To answer this question, we studied masticatory behavior in the osteopetrotic mouse, where tooth eruption does not occur and periodontal mechanoreceptors are missing. A masticatory sequence of the osteopetrotic mouse was divided into two stages: incision and chewing. Incision is characterized by small amplitude and rapid (7 Hz) open-close jaw movements, while slow (5 Hz) and large amplitude open-close jaw movements characterize chewing. The frequency and properties of jaw movements were comparable with those in the normal mouse, though the osteopetrotic mouse had a higher cycle number during incision than did the normal mouse. These results indicate that conversion from sucking to mastication occurs in the anodontic mouse, and the central pattern generator producing the masticatory rhythm develops almost normally without tooth eruption.

Animals↗
PubMed2002

Analysis of northern distribution of Aedes albopictus (Diptera: Culicidae) in Japan by geographical information system.

Aedes albopictus (Skuse), a mosquito vector of the dengue fever virus, is prevalent in Japan, distributed widely in Honshu Island with its northern limits between latitude 38 degrees to 40 degrees north. The factors affecting distribution of the species in the northern part of Japan were studied using the geographical information system (GIS). During 1998-2000, larval surveillance was carried out in 26 urban and rural areas in the Tohoku district, in the northern part of Honshu Island, by collecting larvae from artificial and natural habitats. Climatological analysis, using the GIS, showed that the following conditions accounted for the current distribution of Ae. albopictus: an annual mean temperature higher than 11 degrees C and a mean temperature of the coldest month, January, higher than -2 degrees C. A period with temperature above 11 degrees C in the confirmed area of the mosquito successively continues for more than 186 d per year. The accumulated temperature calculated from a temperature of 11 degrees C, which may be close to the developmental zero of Ae. albopictus, was over 1,350 degree-days. The relationship between the beginning of short-daylength, inducing egg diapause, and the monthly mean temperature during September and October necessary for successful larval development in the Tohoku district is also discussed. We also show the relationship between the current distribution of Ae. albopictus and the annual mean temperature in the United States. From these results it is predicted that Ae. albpictus will be established in some cities in northeast United States.

Aedes↗
PubMed2002

[Reoperation for metachronous pulmonary or tracheal lesions after pneumonectomy].

Although aggressive reoperation for metachronous multiple primary lung cancer or intrathoracic recurrence without distant metastases have been recommended to the patients of primary lung cancer and metastatic lung tumor, surgical indication after a previous pneumonectomy is restricted because of residual pulmonary function. We report about 3 reoperated cases for metachronous pulmonary or tracheal lesions after left pneumonectomy. Case 1: A 61-year old male who underwent left pneumonectomy for primary lung cancer was reoperated for tracheal cancer 41 months after the pneumonectomy. Case 2: A 61-year old male who underwent left pneumonectomy for primary lung cancer was reoperated for metachronous multiple primary lung cancer 59 months after the pneumonectomy. Case 3: A 59-year old male who underwent left pneumonectomy for metastatic lung tumor from rectal cancer was re-operated for intrathoracic recurrence 28 months after the pneumonectomy. All cases are alive without recurrence.

Humans↗
PubMed2002

Biological and chemical treatment of solid waste from soy sauce manufacture.

To reduce the solid waste in soy sauce refuse (SSR) that is a by-product of soy sauce fermentation, both biological and chemical treatment were examined. When anaerobic digestion of SSR was carried out at the amounts of 25 g/l under 30% (v/v) inocula of thermophilic methanogenic sludge at 50 degrees C, 120 mM of CH4 was produced and 50% (w/v) of mixed-liquor suspended solids in SSR was decreased after 35 days. Although in this culture 30 days' cultivation was required to get 100 mM of CH4, when the same amounts of SSR (25 g/l) were repeatedly added to the culture, the time requirement to get 100 mM of CH4 could be reduced to 20 days and 15 days at second and third batch cultures, respectively. When SSR was treated with 5% (w/v) NaOH for 24 h, the supernatant contained 98% (w/v) of protein that were alkaline-solubilized and insoluble in the intact refuse, and the residual pellet contained insoluble fiber.

Bacteria, Anaerobic↗
PubMed2002

Arterial reconstruction in Buerger's disease: by-pass to disease-free collaterals.

BACKGROUND: Arterial reconstructions for ischemia in patients with Buerger's disease are technically challenging. This retrospective review was conducted to identify the critical factor for a successful outcome in bypass surgery for Buerger's disease. METHODS DESIGN OF STUDY: retrospective review. SETTING: University hospital, hospitalized patients. PATIENTS: since 1993, we performed 10 arterial reconstructions in 8 patients with Buerger's disease. There were 8 tibial artery bypasses and 2 collateral artery bypasses. One bypass was performed in the upper extremity. INTERVENTIONS: bypass surgery with autogenous vein graft. MAIN OUTCOMES MEASUREMENTS: graft patency. RESULTS: Over a mean follow-up period of 41.8 months, there were 3 graft occlusions. Of these, 2 were of bypasses to a patent but diseased tibial artery. One graft was occluded due to a toe stenosis which had been previously detected. The 2 collateral artery bypasses were patent at the last follow-up. CONCLUSIONS: In Buerger's disease, distal arterial reconstruction is frequently necessary to prevent ischemic limb loss. Collateral artery bypass is an option when the main arteries are affected by the disease. A patent but diseased artery should be avoided as a target for reconstruction.

Adult↗
PubMed2002

[The usefulness of induction chemotherapy in cases with tumors showing border-line pathological aspects between thymoma and thymic carcinoma].

We present 2 surgically treated cases with thymoma classified as Masaoka stage III and IV a (type B 3 thymoma), which showed the border-line pathological aspects between the thymoma and thymic carcinoma. Induction chemotherapy [CAV-PVP (cyclophosphamide, adriamycin, vincristine sulfate, etoposide) therapy in one case and ADOC (adriamycin, cisplatin, vincristine sulfate, cyclophosphamide) therapy in another case] preluded their surgical resection resulted in reduction of the tumor's size moderately or severely. After achievement of induction chemotherapy, these tumors were resected with the midsternotomy approach, along with resection of the right upper lobe and the left brachiocephalic vein replacing the expanded pdytetrafluoroethylene (ePTFE) graft following mediastinal lymphnodes dissection in one case and leaving the tumor tissue around the pulmonary trunk in another case. Postoperative irradiation of 40 Gy in one case and 60 Gy in another case were performed in the mediastinal regions. From pathological aspects especially in second case, though the specimen by preoperative needle biopsy stained positive for bcl-2 and strong immunoreactivity (20%) for MIB-1, specimens excised operatively after induction chemotherapy showed negative staining for bcl-2 and little staining (lower than 5%) for MIB-1. This fact indicates that the induction chemotherapy makes the tumor less malignant, in other words, from the face of thymic carcinoma to the face of thymoma. Induction chemotherapy performed for the purpose of reducing the tumor size was very advantage in these 2 cases with type B 3 thymoma.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed2001

Granulocyte-macrophage colony-stimulating factor ensures macrophage survival and generation of the superoxide anion: a study using a monocytic-differentiated HL60 subline.

A large number of constituents, such as growth factors, cytokines, and vasoregulatory molecules, contribute a network of cellular interactions to atherosclerotic lesions, and current evidence suggests that granulocyte-macrophage colony-stimulating factor (GM-CSF) is one of these constituents. We conducted this study to determine whether GM-CSF has an effect on the fate and function of macrophages. We examined the effect of GM-CSF on macrophages in vitro with a highly inducible HL60 subclone (HL60/DU-1) that we recently established. HL60 cells have been reported to preserve functional GM-CSF receptors, but a GM-CSF allele was rearranged and partially deleted. HL60/DU-1 cells were devoid of GM-CSF immunoreactivity and of autocrine stimulation of GM-CSF. HL60/DU-1 cells fated to die soon after terminal differentiation of macrophages by 1, 25-dihydroxy vitamin D(3) treatment. We found cell death to be mediated mainly by necrosis, not apoptosis, as confirmed by DNA fragmentation in agarose gel electrophoresis, morphological observation under a fluorescence microscope, and assay of lactate dehydrogenase release. Exogeneously administered GM-CSF rescued cells from necrotic death and caused them to survive and generate superoxide anions. We also conducted immunohistochemical analysis on an atherosclerotic human artery. Macrophages, endothelial cells, and smooth muscle cells were found to be GM-CSF positive in an atherosclerotic lesion. In summary, GM-CSF, which is produced by macrophages, endothelial cells, and smooth muscle cells, is thought to act in an autocrine and a paracrine fashion as a necrosis-inhibiting factor against arterial macrophages. This unique function may play an important role in ensuring survival and promoting function in atherosclerotic lesions.

Aorta↗
PubMed2001

Lembehyne A, a spongean polyacetylene, induces neuronal differentiation in neuroblastoma cell.

Lembehyne A (LB-A), a spongean polyacetylene, induced neuronal cell differentiation in a neuroblastoma cell line, Neuro 2A. The LB-A treatment of Neuro 2A cells predominantly resulted in a morphological change with bipolar neurites. The acetylcholinesterase activity of Neuro 2A was also increased by the treatment of LB-A. Furthermore, the cell cycle of Neuro 2A cells was found to be specifically blocked at the G1 phase by LB-A. The structure-activity relationship study using the LB-A analogues revealed the importance of the terminal 1-yn-3-ol and unsaturated long-chain alkyl moieties for the neuronal differentiation activity of LB-A.

Acetylcholinesterase↗
PubMed2001

Morphological evidence for lipid peroxidation and protein glycoxidation in spinal cords from sporadic amyotrophic lateral sclerosis patients.

For determining whether both the spinal cord motor neurons and glial cells are exposed to increased oxidative stress in amyotrophic lateral sclerosis (ALS), we performed an immunohistochemical investigation of end products of lipid peroxidation and protein glycoxidation in spinal cords from seven sporadic ALS patients and seven age-matched control individuals. In the ALS spinal cords, immunoreactivities for adducts of 4-hydroxy-2-nonenal-histidine and crotonaldehyde-lysine as markers of lipid peroxidation, N(epsilon)-(carboxymethyl)lysine as a marker of lipid peroxidation or protein glycoxidation, and pentosidine as a marker of protein glycoxidation were localized in the gray matter neuropil and almost all of the motor neurons, reactive astrocytes and microglia/macrophages, whereas none of the immunoreactivities for N(epsilon)-(carboxyethyl)lysine or argpyrimidine as markers of protein glycoxidation or enzymatic glycolysis, or pyrraline or imidazolone as markers of nonoxidative protein glycation were detectable. The control spinal cords displayed no significant immunoreactivities for any of these examined products. Our results indicate that in sporadic ALS, both lipid peroxidation and protein glycoxidation are enhanced in the spinal cord motor neurons and glial cells, and suggest that the formation of certain products in these abnormal reactions is implicated in motor neuron degeneration.

Aged↗
PubMed2001

Ca(2+)-dependent, myosin subfragment 1-induced proximity changes between actin and the inhibitory region of troponin I.

In order to help understand the spatial rearrangements of thin filament proteins during the regulation of muscle contraction, we used fluorescence resonance energy transfer (FRET) to measure Ca(2+)-dependent, myosin-induced changes in distances and fluorescence energy transfer efficiencies between actin and the inhibitory region of troponin I (TnI). We labeled the single Cys-117 of a mutant TnI with N-(iodoacetyl)-N'-(1-sulfo-5-naphthyl)ethylenediamine (IAEDANS) and Cys-374 of actin with 4-dimethylaminophenylazophenyl-4'-maleimide (DABmal). These fluorescent probes were used as donor and acceptor, respectively, for the FRET measurements. We reconstituted a troponin-tropomyosin (Tn-Tm) complex which contained the AEDANS-labeled mutant TnI, together with natural troponin T (TnT), troponin C (TnC) and tropomyosin (Tm) from rabbit fast skeletal muscle. Fluorescence titration of the AEDANS-labeled Tn-Tm complex with DABmal-labeled actin, in the presence and absence of Ca(2+), resulted in proportional, linear increases in energy transfer efficiency up to a 7:1 molar excess of actin over Tn-Tm. The distance between AEDANS on TnI Cys-117 and DABmal on actin Cys-374 increased from 37.9 A to 44.1 A when Ca(2+) bound to the regulatory sites of TnC. Titration of reconstituted thin filaments, containing AEDANS-labeled Tn-Tm and DABmal-labeled actin, with myosin subfragment 1 (S1) decreased the energy transfer efficiency, in both the presence and absence of Ca(2+). The maximum decrease occurred at well below stoichiometric levels of S1 binding to actin, showing a cooperative effect of S1 on the state of the thin filaments. S1:actin molar ratios of approximately 0.1 in the presence of Ca(2+), and approximately 0.3 in the absence of Ca(2+), were sufficient to cause a 50% reduction in normalized transfer efficiency. The distance between AEDANS on TnI Cys-117 and DABmal on actin Cys-374 increased by approximately 7 A in the presence of Ca(2+) and by approximately 2 A in the absence of Ca(2+) when S1 bound to actin. Our results suggest that TnI's interaction with actin inhibits actomyosin ATPase activity by modulating the equilibria among active and inactive states of the thin filament. Structural rearrangements caused by myosin S1 binding to the thin filament, as detected by FRET measurements, are consistent with the cooperative behavior of the thin filament proteins.

Actins↗
PubMed2001

Multiscale computing.

Multiscale computing (MSC) involves the computation, manipulation, and analysis of information at different resolution levels. Widespread use of MSC algorithms and the discovery of important relationships between different approaches to implementation were catalyzed, in part, by the recent interest in wavelets. We present two examples that demonstrate how MSC can help scientists understand complex data. The first is from acoustical signal processing and the second is from computer graphics.

Computer Graphics↗