PubMed Health⌕ Search

Biomedical subjects

K Takeuchi

Publications and source records attributed to K Takeuchi.

At least 181 records · Page 10Linked to original sources
PubMed2001

Quantitative determination of the role of lettuce leaf structures in protecting Escherichia coli O157:H7 from chlorine disinfection.

Viability of Escherichia coli O157:H7 cells on lettuce leaves after 200 mg/liter (200 ppm) chlorine treatment and the role of lettuce leaf structures in protecting cells from chlorine inactivation were evaluated by confocal scanning microscopy (CSLM). Lettuce samples (2 by 2 cm) were inoculated by immersing in a suspension containing 10(9) CFU/ml of E. coli O157: H7 for 24+/-1 h at 4 degrees C. Rinsed samples were treated with 200 mg/liter (200 ppm) chlorine for 5 min at 22 degrees C. Viability of E. coli O157:H7 cells was evaluated by CSLM observation of samples stained with Sytox green (dead cell stain) and Alexa 594 conjugated antibody against E. coli O157:H7. Quantitative microscopic observations of viability were made at intact leaf surface, stomata, and damaged tissue. Most E. coli O157:H7 cells (68.3+/-16.2%) that had penetrated 30 to 40 microm from the damaged tissue surface remained viable after chlorine treatment. Cells on the surface survived least (25.2+/-15.8% survival), while cells that penetrated 0 to 10 microm from the damaged tissue surface or entered stomata showed intermediate survival (50.8 +/-13.5 and 45.6+/-9.7% survival, respectively). Viability was associated with the depth at which E. coli O157:H7 cells were in the stomata. Although cells on the leaf surface were mostly inactivated, some viable cells were observed in cracks of cuticle and on the trichome. These results demonstrate the importance of lettuce leaf structures in the protection of E. coli O157:H7 cells from chlorine inactivation.

Chlorine↗
PubMed2001

Expression of red-shifted green fluorescent protein by Escherichia coli O157:H7 as a marker for the detection of cells on fresh produce.

Escherichia coli O157:H7 was transformed with a plasmid vector red-shifted green fluorescence protein (pEGFP) to express red-shifted green fluorescence protein (EGFP) from Aequorea victoria. The EGFP expression among total cells and nonviable cells was determined at the cellular level by microscopic observation of immunostained and membrane-impermeable, dye-stained cultures, respectively. E. coli O157:H7 retained pEGFP during frozen storage at -80 degrees C. The percentage of EGFP expression was improved by repeated subculturing, reaching 83.4 +/- 0.1%, although the fluorescence intensity varied among cells. A low percentage of EGFP-expressing cells was nonviable. The percentage of EGFP decreased when the culture plate was kept at 4 degrees C, suggesting that some cells lost pEGFP during refrigeration. The storage of the culture suspension in sterile deionized water at 4 degrees C for 24 h reduced the percentage of EGFP expression, indicating that some EGFP was denatured. The application of EGFP as a marker for E. coli O157:H7 on green leaf lettuce, cauliflower, and tomato was evaluated using confocal scanning laser microscopy. EGFP-transformed cells were readily visible under confocal scanning laser microscopy on all produce types. The numbers of E. coli O157:H7 cells detected with EGFP were equivalent to those detected with immunostaining for green leaf lettuce and cauliflower but less for tomato. E. coli O157:H7 attached preferentially to damaged tissues of green leaf lettuce and tomato over intact tissue surfaces and to flowerets of cauliflower than to stem surfaces. EGFP can serve as a marker to characterize E. coli O157:H7 attachment on green leaf lettuce and cauliflower but may not be suitable on tomato.

Brassica↗
PubMed2001

Direct microscopic observation of lettuce leaf decontamination with a prototype fruit and vegetable washing solution and 1% NaCl-NaHCO3.

Efficacy of a prototype, food-grade alkaline surfactant washing solution and 1% NaCl-NaHCO3 (pH 10.0) against Escherichia coli O157:H7 cells on lettuce leaves was evaluated. Lettuce was inoculated with 10(9) CFU/ml of E. coli O157:H7 for 24 +/- 1 h at 4 degrees C. Samples were rinsed and treated with the prototype washing solution containing lauryl sodium sulfate or NaCl-NaHCO3 for 3 min at 22 degrees C. Viability of E. coli O157:H7 cells was examined by plate counts at the surface and cut edge, and by confocal scanning microscopic (CSLM) observation of samples stained with Sytox green and Alexa 594 conjugated antibody against E. coli O157:H7 at intact leaf surface, stomata, and damaged tissue (0 to 10, 30 to 40, and 0 to 40 microm from the cut surface). Although both treatments caused significant log reductions in CFU at the surface and cut edge, log reductions were greater for the prototype washing solution (0.7 to 1.1 log CFU/cm2) than for NaCl-NaHCO3 (0.2 to 0.4 log CFU/cm2) (P < 0.05). Percentage of viability determined by CSLM for prototype washing solution was significantly greater at 30 to 40 microm from cut surfaces than at 0 to 10 and 0 to 40 microm from cut surfaces and intact surfaces (P < 0.05). Stomata provided moderate protection. NaCl-NaHCO3 was less effective than the prototype washing solution, and high percentages of E. coli O157:H7 cells remained viable at all sites except at the surface. The percent viabilities determined by CSLM were not significantly different from those determined by plate counts for NaCl-NaHCO3 treatment (P > 0.05). However, CSLM indicated significantly greater percent viability than plate counts for lettuce treated with the prototype washing solution (P < 0.05). Surfactant-containing washing solutions warrant additional testing for decontamination of fresh produce.

Colony Count, Microbial↗
PubMed2001

Expression of matrix metalloproteinase 3 in experimental atherosclerotic plaques.

In atherosclerotic lesions, matrix metalloproteinases produced by foam cells (macrophages) are thought to increase plaque instability, promote plaque rupture, by degradating extracellular matrix. To investigate the relationship between the expression of these proteinases and the histologic appearance of atheromas, immunohistochemical analysis of matrix metalloproteinase 3 and cell-type markers was performed in atherosclerotic plaques induced in rabbit abdominal aortas by high-cholesterol diets and mechanical injury. In addition to an antibody against matrix metalloproteinase 3, RAM-11 and HHF-35 were used to detect macrophages and smooth muscle cells, respectively. Matrix metalloproteinase 3 was expressed diffusely within the plaques with a fibrofatty histologic pattern. In plaques with foam cell accumulation, matrix metalloproteinase 3 was seen in areas rich in foam cells and the smooth muscle cells near the lumen. In the plaques with fewer macrophages, the proteinase was expressed only in such smooth muscle cells. Matrix metalloproteinase 3 was expressed in the smooth muscle cells in plaques of all histologic types, and macrophages also expressed the metalloproteinase when present in significant numbers. These findings suggest that macrophage accumulation plays an important pathophysiologic role in causing the instability of atherosclerotic lesions by increasing the levels of matrix metalloproteinase 3.

Animals↗
PubMed2001

[Desmoid tumor of the chest wall infiltrating into the brachial plexus: report of a resected case].

We report a case of a desmoid tumor which developed in the apex of the chest wall. A 18-year-old woman was admitted with left shoulder pain. Chest X-ray showed a mass shadow in the left upper lung field. Chest MRI demonstrated the mass infiltrated into the left brachial plexus. A desmoid tumor was suspected on percutaneous needle biopsy. Resection of the tumor was performed. The mass was 13 x 9 x 5 cm in size and diagnosed pathologically as desmoid tumor. Adjunctive postoperative radiation therapy of 60 Gy was done. Postoperative course was uneventful except motor disturbances of the left fingers. At 15 months postoperatively, there was no evidence of recurrence.

Adolescent↗
PubMed2001

Stimulation by nitric oxide of gastric acid secretion in bullfrog fundic mucosa in vitro.

We examined the effect of NO on acid secretion in vitro using isolated preparations of Bullfrog stomach. The bullfrog fundic mucosa was bathed in unbuffered Ringer solution gassed with 100% O2 on the mucosal side and HCO3- Ringer's solution gassed with 95% O2/5% CO2 on the serosal side, and the acid secretion was measured at pH 5.0 using the pH-stat method and by adding 5 mM NaOH. Serosal addition of a NO donor NOR-3 (10(-5) approximately 10(-3) M: (+/-)-(E)-ethyl-2-[(E)-hydroxyimino]-5-nitro-3-hexnamine) caused an increase of acid secretion in a dose-dependent manner, the effect lasting about 1 hr and reaching a maximal level of 2-fold the basal values. The acid stimulatory effect of NOR-3 was mimicked by another NO donor SNAP (10(-3) mol/L: S-nitroso-O-N-acetyl-penicillamine) and markedly and markedly inhibited by prior administration of cimetidine (10(-5) mol/L) as well as compound 48/80 (the mast cell degranulator). Likewise, the increased acid response to NOR-3 was significantly mitigatd by pretreatment with carboxy-PTIO (a NO scavenger) or superoxide dismutase (SOD), but not by indomethacin or methylene blue (a guanylyl cyclase inhibitor). Neoither L-NAME, L-arginine nor dibutyryl guanosine-3',5'-cyclic monophosphate (dbcGMP) has any effect on the basal acid secretion. Serosal addition of NOR-3 caused a significant increase in the luminal release of histamine, and this response was inhibited by pretreatment with either compound 48/80, carboxy-PTIO or SOD. These results suggest that the NO donor increases gastric acid secretion in the isolated frog stomach in vitro, and this action is mediated by endogenous histamine released from mast cells, the process being cGMP-independent but requiring the presence of superoxide radicals. In addition, it was speculated that the histamine releasing action of NO may be due to peroxynitrite produced by NO and superoxide radicals.

Animals↗
PubMed2001

Adaptive gastric cytoprotection is mediated by prostaglandin EP1 receptors: a study using rats and knockout mice.

Endogenous prostaglandins (PGs) play a central role in adaptive cytoprotection induced in the stomach by mild irritants. In the present study, we used taurocholate (TC) as a mild irritant in both rats and EP-receptor knockout mice, and examined which EP receptor is responsible for the adaptive gastric cytoprotection. Gastric lesions were induced by p.o. administration of HCl/ethanol (60% ethanol in 150 mM HCl). TC (5-20 mM) or PGE2 was administered p.o. 30 min before HCl/ethanol. HCl/ethanol-induced gastric lesions were dose dependently prevented by TC, and the effect at 20 mM was equivalent to that induced by PGE2 at 0.3 mg/kg. The protective effect of TC was significantly attenuated by indomethacin as well as ONO-AE-829, the EP1 antagonist, but not by either NS-398, the selective cyclooxygenase (COX)-2 inhibitor, or chemical ablation of capsaicin-sensitive sensory neurons. Likewise, the protective action of PGE2 was also antagonized by ONO-AE-829 but not chemical deafferentation. TC significantly increased PGE2 contents in the stomach, with or without chemical deafferentation, and this effect was blocked in the presence of indomethacin but not NS-398 or ONO-AE-829. TC increased the mucosal PGE2 contents similarly in both wild-type and knockout mice lacking EP1 or EP3 receptors, yet the protective action of TC against HCl/ethanol was observed in both wild-type and EP3 receptor knockout mice, but not in mice lacking EP1 receptors. The present findings confirmed a role for endogenous PGE2 produced by COX-1 in adaptive gastric cytoprotection and suggested that this action is mediated by activation of EP1-receptors but not associated with capsaicin-sensitive afferent neurons.

Adaptation, Physiological↗
PubMed2001

[The measurement of immature reticulocyte fractions and clinical significance].

We evaluated automated analysis for the measurement of immature reticulocyte fraction(IRF) in 222 blood samples. IRF was performed by R-3000 & XE-2100(Sysmex), VEGA RETIC LC141(Horiba), ADVIA 120(Bayer medical), CELL DYN4000(Abbott) or GEN'S(Coulter), and compared with measurements obtained by visual counting. A subfraction of IRF was also determined using different modalities on all analyzers. The values of IRF were stable after blood storage for 48 hours at 4 degrees C and 8 hours at room temperature. A good correlation of IRF among these analyzers was obtained(r = 0.629-0.869), but the normal ranges in the percentage of IRF varied according to analyzers. However, an elevation in the percentage of IRF is the first sign of bone marrow recovery after chemotherapy and the bone marrow transplantation in the majority of leukemic patients. We suggest that IRF counting is useful for the estimation of early phase erythropoiesis in patients who have successful bone marrow engraftment following bone marrow transplantation.

Hematologic Diseases↗
PubMed2001

[Effect of actarit combination therapy in patients with active rheumatoid arthritis resistant to gold agents].

We investigated the utility of combination therapy of actarit with gold agents in patients with active rheumatoid arthritis resistant to gold agents even after the administration of gold agents for longer than 24 weeks in principle. 1. In the final global improvement rate by the combination therapy of actarit with gold agents, the ratio of "improved" and/or better was 30.8% (12/39). 2. The clinical evaluation items which showed significant improvement were grip strength, ESR, number of painful joints, number of swollen joints, active joint count, duration of morning stiffness and Lansbury's activity index. 3. ADRs were observed in 6 patients per 75 patients (8.0%), but there was no serious ADR.

Aged↗
PubMed2001

Rupture of the spleen as an unusual complication of laparoscopy. A case report.

BACKGROUND: Laparoscopic surgery has many advantages but is not without complications, such as viscus perforation and intraabdominal hemorrhage. CASE: A rare and severe complication, massive abdominal bleeding due to splenic rupture, became symptomatic after an uneventful laparoscopy. Tearing away of delicate peritoneal reflections or small adhesions on the splenic capsule due to induction of pneumoperitoneum can result in sudden rupture and hemorrhage. CONCLUSION: This possibility should be remembered when laparoscopy is necessary in patients with a history of blunt abdominal trauma.

Abdominal Injuries↗
PubMed2001

Clinical significance of antibiotic therapy in guided tissue regeneration with a resorbable membrane.

This study was designed to evaluate the clinical significance of antibiotic therapy combined with guided tissue regeneration (GTR) therapy with a collagen membrane. The subjects were 20 adults diagnosed with periodontitis (20 intrabony periodontal defects). Ten patients were treated with GTR alone (control group) and the other 10 patients were treated with a combination of GTR and antibiotics (antibiotic group). In the antibiotic group, minocycline ointment was applied locally before GTR therapy, and doxycycline and amoxyline were systemically administered after GTR therapy. Clinical manifestations, the presence or absence of exposed membrane, and microbiological findings were assessed 1 month before, immediately after, and 2 weeks, 6 weeks, and 3 months after GTR therapy. The results showed no significant differences in reduction of probing depth, probing attachment gain (PAG), or the ratio of PAG to intraoperative depth of the intrabony defect (vertical relative attachment gain) between the antibiotic group and the control group before and 3 months after GTR therapy. A DNA probe test and specific enzymatic activity test revealed no significant differences in the improvement and the rate of bacterial negativity before, and 6 weeks and 3 months after, GTR therapy. These findings indicate that antibiotic therapy is not clinically beneficial when combined with GTR therapy with a collagen membrane.

Absorbable Implants↗
PubMed2001

[Therapeutic plasmapheresis for the prevention of congenital complete heart block associated with anti-SS-A/Ro antibody and anti-SS-B/La antibody].

OBJECTIVES: Neonatal lupus erythematosus is characterized by transient lupus abnormalities, various systemic and hematological abnormalities, and congenital complete heart block (CCHB). It is well known that anti-SS-A/Ro antibody (52 kD/60 kD) and anti-SS-B/La antibody are associated with CCHB. This study was conducted to evaluate the effects of the removal of anti-SS-A/Ro antibody (52 kD/60 kD) and anti-SS-B/La antibody from plasma in pregnant women whose fetuses are at a high risk of developing CCHB. MATERIALS & METHODS: Fifteen pregnant patients positive for anti-SS-A/Ro antibody and anti-SS-B/Laantibody were subjected weekly to double filtration plasmapheresis to remove both antibodies. Antibody titers were measured by double immunodiffusion (DID) and ELISA. RESULTS: As a result, all women gave birth to live babies, but CCHB was recognized in one baby. No transient lupus abnormalities were recognized in any of the babies. Fourteen patients showed decreased antibody titers by ELISA during plasmapheresis. However, the patient who was delivered of a baby with CCHB showed an increase of antibody titers by ELISA while the DID method showed a decrease of antibody titers. CONCLUSION: Our study suggested that plasmapheresis prevents CCHB associated with anti-SS-A/Ro and anti-SS-B/La antibody. Also, it is important to monitor the antibody titer regularly during the course of pregnancy, because it may increase due to worsening of the mother's primary disease.

Adult↗
PubMed2001

[A high aged case of herpes simplex viral encephalitis associated with progressive cerebral white matter lesion].

An 80-year-old male without abnormal past medical history presented with coma, general seizures, and fever subsequent to abnormal behavior. The pressure of the cerebrospinal fluid(CSF) elevated(13.5-20.5 cm H2O), and CSF examination revealed pleocytosis with predominant mononuclear cells(80-879/mm3) and elevated protein level(32-130 mg/dl). DNAs of herpes simplex virus(HSV) type 1 and 2 in CSF were not confirmed by polymerase chain reaction method in the acute phase. The HSV(type 1) antibody(HSV-1 Ab) ratio of serum to CSF(= [serum HSV-1 Ab]/[CSF HSV-1 Ab]) was 0.98 and HSV-1 Ab index(= [CSF HSV-1 Ab]/[serum HSV-1 Ab] divided by [CSF albumin]/[serum albumin]) was 62.4. Initial fluid attenuated inversion recovery(FLAIR) (TR/TE/TI = 6,882/110/1,700 msec) axial magnetic resonance(MR) imaging showed hyperintensity in the subfrontal area, inferomedial portions of the temporal lobes, cingulate gyri, and insular cortices bilaterally. Meningoencephalitis caused by HSV-1 was diagnosed based on the values of HSV-1 Ab ratio of serum to CSF(less than 20), of HSV-1 Ab index(larger than 1.91), and the findings of MR imaging. Diffuse white matter lesions manifesting hyperintensity on FLAIR imaging in the bilateral frontal and temporal lobes close to the affected cortices developed approximately six weeks after the onset despite administration of antiviral agent and steroid. The lesion extensively involved the white matter of the bilateral frontal and temporal lobes finally. The initial value of myelin basic protein(MBP) in CSF was 0.9 ng/ml (normal value: less than 4 ng/ml). Subsequent measurement of MBP in CSF about two, six weeks, two, three, and six months after the onset showed a marked increase of 233.9 ng/ml followed by a gradual decrease of 25.4 ng/ml, 18.4 ng/ml, 7.4 ng/ml and 4.3 ng/ml, respectively. Therefore, demyelination of the lesion in the cerebral white matter was suggested by the chronological change in FLAIR imaging and MBP in CSF.

Aged↗
PubMed2001

[A case of bronchogenic cyst which developed from negative findings to a thin-walled cavity for about 6 years].

A 56-year-old man whose chest radiograph in 1993 was normal was referred to our hospital because of a productive cough in 1997. Chest radiographs showed a thin-walled cavity filled with air. We followed his condition radiographically for three years and observed enlargement of the diameter of the lesion and appearance of an air fluid level, and we therefore decided to perform thoracoscopic middle lobe resection in 1999. Histological examination showed a communication between the cavity and a bronchus. As far as we know, there are no previous reports about intrapulmonary bronchogenic cysts which on radiographic observation developed from negative findings to a thin-walled cavity filled with air over a 6-year period.

Bronchogenic Cyst↗
PubMed2001

[Spinal cord sarcoidosis without abnormal shadows on chest radiography or chest CT diagnosed by transbronchial lung biopsy].

The patient was a woman aged 56 years. In February 1998, she complained of fatigability of the right upper limb and disturbed extension of the right fourth finger. Because her condition deteriorated gradually and myelopathic signs such as difficulty in walking developed, she was hospitalized in May 1999 for close examination and appropriate treatment; and she was a few days later transferred to our hospital because of progressive myelopathy. In T2-weighted MR images of the cervical spine, the high-intensity area ranged between C2 and Th1, and in Gd-DTPA enhanced MRI the high-intensity area was seen between C3 and C7. Although chest radiographs and chest CT scans were normal, spinal cord sarcoidosis could not be ruled out, and therefore, bronchoscopic examination was performed. Specimens obtained from transbronchial lung biopsy (TBLB) revealed non-caseating epithelioid cell granulomas, and so and the disease was diagnosed as spinal cord sarcoidosis. Both symptoms and MRI findings were improved by treatment with corticosteroids. It is suggested that, in patients suspected of spinal cord sarcoidosis from MRI findings. TBLB should be aggressively attempted, even if chest radiographs and chest CT scans are normal.

Biopsy↗
PubMed2000

Myosin light-chain kinase regulates endothelial calcium entry and endothelium-dependent vasodilation.

Activation of smooth muscle myosin light-chain kinase (MLCK) causes contraction. Here we have proven that MLCK controls Ca2+ entry (CE) in endothelial cells (ECs): MLCK antisense oligonucleotides strongly prevented bradykinin (BK)- and thapsigargin (TG)-induced endothelial Ca2+ response, while MLCK sense did not. We also show that the relevant mechanism is not phosphorylation of myosin light-chain (MLC): MLC phosphorylation by BK required CE, but MLC phosphorylation caused by the phosphatase inhibitor calyculin A did not trigger Ca2+ response. Most important, we provide for the first time strong evidence that, in contrast to its role in smooth muscle cells, activation of MLCK in ECs stimulates the production of important endothelium-derived vascular relaxing factors: MLCK antisense and MLCK inhibitors abolished BK- and TG-induced nitric oxide production, and MLCK inhibitors substantially inhibited acetylcholine-stimulated hyperpolarization of smooth muscle cell membrane in rat mesenteric artery. These results indicate that MLCK controls endothelial CE, but not through MLC phosphorylation, and unveils a hitherto unknown physiological function of the enzyme: vasodilation through its action in endothelial cells. The study discovers a counter-balancing role of MLCK in the regulation of vascular tone.

Acetylcholine↗