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Biomedical subjects

T Tashiro

Publications and source records attributed to T Tashiro.

At least 19 recordsLinked to original sources
PubMed2001

Preoperative immunosuppression: its relationship with high morbidity and mortality in patients receiving thoracic esophagectomy.

The operative procedure for thoracic esophageal cancer, including thoracotomy, laparotomy, and three-field lymph node dissection, is a particularly stressful surgery that is characterized by high morbidity and mortality. The aim of this study was to evaluate the immunologic and nutritional states of patients to determine possible predictive factors of morbidity and mortality in patients receiving thoracic esophagectomy. Patients receiving thoracic esophagectomy were retrospectively divided into two groups. One group had postoperative infectious complications (group C+, n = 27), and the other had no complications (group C-, n = 76). They were treated with total parenteral nutrition or enteral nutrition providing 35-40 kcal. kg(-1). d(-1) of energy and 1.3-1.5 kcal. kg(-1). d(-1) of amino acids throughout the study period. The phytohemagglutinin (PHA)- and concanavalin A (Con A)-induced proliferation of peripheral blood mononuclear cells (PBMC) from the patients were measured before and at days 7 and 21 after the operation. Serum albumin, prealbumin, transferrin, the retinol binding protein, and the C-reactive protein were also evaluated. Three patients out of 27 in group C+ died because of severe infectious complications, whereas none of patients was fatal in group C-. PHA- and Con A-induced proliferation of PBMC was significantly low before the operation and remained suppressed on the 21st postoperative day in group C+. No significant difference was observed in nutritional status during the perioperative days between the two groups. Our results indicate that esophageal cancer patients with preoperative suppression of the cell-mediated immunity can be identified as a higher risk population in the postoperative period. When adequate nutrition is received, however, the correlation between nutritional status and mortality disappears.

Blood Proteins↗
PubMed2000

Body image as a visuomotor transformation device revealed in adaptation to reversed vision.

People adapt with remarkable flexibility to reversal of the visual field caused by prism spectacles. With sufficient time, this adaptation restores visually guided behaviour and perceptual harmony between the visible and tactile worlds. Although it has been suggested that seeing one's own body is crucial for adaptation, the underlying mechanisms are unclear. Here we show that a new representation of visuomotor mapping with respect to the hands emerges in a month during adaptation to reversed vision. The subjects become bi-perceptual, or able to use both new and old representations. In a visual task designed to assess the new hand representation, subjects identified visually presented hands as left or right by matching the picture to the representation of their own hands. Functional magnetic resonance imaging showed brain activity in the left posterior frontal cortex (Broca's area) that was unique to the new hand representations of both hands, together with activation in the intraparietal sulcus and prefrontal cortex. The emergence of the new hand representation coincided with the adaptation of perceived location of visible objects in space. These results suggest that the hand representation operates as a visuomotor transformation device that provides an arm-centred frame of reference for space perception.

Adaptation, Physiological↗
PubMed2000

Gastrointestinal stromal tumor with skeinoid fibers of the ileum.

Gastrointestinal stromal tumor (GIST) is not uncommon among gastrointestinal nonepithelial tumors, but there are few reports describing the cytologic findings. We report a case of GIST with skeinoid fibers in scrape cytology preparation. The patient was a 53-year-old man with a tumor in the small intestine. Scrape preparations from the cut surface of the resected tumor revealed cellular material composed of spindle cells showing loose clusters or single cells. The nuclei were spindled, elongated or cigar-shaped, and relatively uniform. The cytoplasm was fragile and demonstrated a finely fibrillar material. Dense hyaline materials with irregular outline were observed within the loose clusters composed of the tumor cells. The hyaline materials were also observed in the background. Histologic preparation showed spindle cells arranged in a fascicular or storiform pattern. Most eosinophilic globules were distributed between the tumor cells. The globules were positive in periodic acid-Schiff reaction, and were stained blue with Masson's trichrome stain. Immunohistochemically, the tumor cells were strongly and diffusely positive for c-kit, focally and weakly positive for alpha-smooth muscle actin, and negative for CD34 and S-100 protein. We emphasize that skeinoid fibers are characteristic of GIST arising in the small intestine, and their presence predicts a good prognosis, even in malignant GIST.

Gastrointestinal Neoplasms↗
PubMed2000

Adhesion formation can be reduced by the suppression of transforming growth factor-beta1 activity.

Surgery or trauma often results in restrictive adhesions around joints or tendons that cause severe functional impairment. The formation of adhesion is essentially a fibrogenetic process; therefore, peptide growth factors, such as transforming growth factor-beta, are assumed to play central roles in its development. The purpose of this study was to test the hypothesis that suppression of transforming growth factor-beta1 activity reduces adhesion formation. Sixty rabbits were prepared and randomly divided into six groups of 10. Intraarticular adhesions were created in the right knee joints by cortical bone shaving and subsequent cast immobilization for 4 weeks. In animals in three of the six groups, transforming growth factor-beta1 activity was suppressed by continuous administration of the neutralizing antibody in three graded doses; animals in the other three groups were used as controls. Four weeks after the surgery, the casts were removed and the adhesions were assessed macroscopically, histologically, biomechanically, and biochemically. Gross observation showed that the neutralizing antibody had suppressed adhesion formation in a dose-dependent manner. This is consistent with biomechanical measurement results demonstrating that the antibody reduced the flexion contractures. Histologically, the adhesion in our model was fibrous tissue and the adhesions in the animals in the antibody groups were thin and loose in comparison with the controls. Biochemical analyses further supported these results, demonstrating that administration of the antibody reduced collagen content in the adhesions with a predominance of type-I collagen. Thus, this study showed that suppression of the actions of transforming growth factor-beta1 reduced adhesion formation. Considering the various possible measures to control the activity of the growth factor, suppression of transforming growth factor-beta may be a novel, potent approach to preventing adhesions.

Animals↗
PubMed2000

Rathke's cleft cyst associated with hypophysitis: MRI.

We report a symptomatic Rathke's cleft cyst associated with hypophysitis in a 61-year-old woman. We demonstrate the MRI features and discuss the pathophysiology. To the best of our knowledge this is the first description of a Rathke's cleft cyst shrinking after high-dose steroid therapy.

Adrenal Cortex Hormones↗
PubMed2000

Human amniotic epithelial cells are promising transgene carriers for allogeneic cell transplantation into liver.

As human amniotic epithelial tissue is formed on about the eighth day after fertilization, human amniotic epithelial cells (hAEC) may have multipotency to differentiate into various organs, such as brain, heart, or liver. In this study, we showed evidence of the synthesis and excretion of albumin by hAEC, by immunostaining and enzyme-linked immunoassay. Reverse transcription-polymerase chain reaction (RT-PCR) and western blot analyses revealed the expression of albumin mRNA and protein, respectively. In addition, hAEC also demonstrated immunoreactivity to genetic markers of liver lineage, such as human serum albumin and alpha-fetoprotein. Transplanted hAEC to Scid mouse liver showed positive immunoreactivity to albumin and alpha-fetoprotein. Genetically modified cells containing the beta-galactosidase (LacZ) gene (AxCALacZ) were integrated in liver parenchyma. Human polymorphic gene analysis in Scid mouse liver after the implantation of hAEC showed that these Scid mouse livers obviously contained this human-specific gene until day 7 after the cell transplantation. As hAEC do not cause any acute rejection by allotransplantation, we conclude that hAEC may be useful as a transgene carrier to treat patients with inherited liver diseases.

Albumins↗
PubMed2000

Modulating effects of the feeding route on stress response and endotoxin translocation in severely stressed patients receiving thoracic esophagectomy.

Experimental studies have demonstrated that the route of nutritional supply impacts the systemic metabolic responses after surgical injury. Intestinal mucosal atrophy, as induced by total parenteral nutrition (TPN) or prolonged bowel rest, has been reported to enhance bowel endotoxin translocation. The operative procedure for thoracic esophageal cancer, including thoracotomy, laparotomy, and three-field lymph-node dissection, is a particularly stressful surgery that requires long-term aggressive nutritional support and often results in the postoperative hypermetabolic state, leading to perturbation of postoperative immune function. Interleukin-6 (IL-6) plays an important role in host inflammatory responses, whereas IL-10 is linked to suppression of cellular immunity. The aim of this study was to investigate how the antecedent nutritional routes influence systemic IL-6 and IL-10 responses and endotoxin translocation after an operation for thoracic esophageal cancer. Twenty-nine patients who underwent esophagectomy with three-field lymphadenectomy were investigated. They were assigned to groups receiving either TPN (n = 18) or enteral nutrition (EN; n = 11) providing 35 kcal x kg(-1) x d(-1) of energy and approximately 1.2-1.5 g x kg(-1) x d(-1) of amino acids. These nutritional supports were conducted from 1 wk before the operation to 14 d after the operation. Serum IL-6, IL-10, and endotoxin concentration were measured before and during the operation and at 2 h and 1, 3, and 7 d after the operation. IL-6 in sera was significantly higher after the operation in both groups. In the EN group, however, significantly less IL-6 production was observed on the third and seventh postoperative days when compared with those patients in the TPN group. Similarly, serum IL-10 concentration in the TPN group showed a significantly higher level than that in the EN group. Serum IL-6 showed a significant positive correlation with IL-10 at 2 h and at 7 d after the operation, suggesting that the reduced inflammatory responses were related to the inhibition of the development of postoperative immunosuppression. Endotoxin concentration in sera was significantly lower in the EN group after the operation than in the TPN group. Perioperative EN provides better regulation of inflammatory cytokine responses and may contribute less to immunosuppression after major surgery than parenteral nutrition. The attenuated production of endotoxin induced by EN may play an important role in these phenomena.

Bacterial Translocation↗
PubMed2000

Well-differentiated adenocarcinoma of the gallbladder mimicking minimal deviation adenocarcinoma of the cervix.

We report a case of well-differentiated adenocarcinoma of the gallbladder, histologically mimicking minimal deviation adenocarcinoma (MDA) of the cervix. A 71-year-old Japanese male underwent cholecystectomy because of the suggestion of gallbladder carcinoma. The resected gallbladder showed a localized thickening of the gallbladder wall with a polypoid lesion measuring 12x7 mm in diameter. Microscopically, the polypoid lesion proved to be a well-differentiated adenocarcinoma composed of columnar cells with a clear cytoplasm. In the thickened gallbladder wall, well-formed glands were extensively distributed; they were surrounded by a slightly desmoplastic reaction instead of lamina propria, or were directly in contact with smooth muscle cells. The diagnostic criteria for cervical MDA may be useful in distinguishing well-differentiated adenocarcinoma of the gallbladder from benign conditions, such as Rokitansky-Aschoff sinus and adenomyomatosis. It is remarkable that the tumor cells of the present case expressed gastric type mucin which is characteristic of mucinous type cervical MDA.

Adenocarcinoma↗
PubMed2000

Effects of macrophage colony-stimulating factor (M-CSF) on anti-fungal activity of mononuclear phagocytes against Trichosporon asahii.

Trichosporon asahii is an emerging opportunistic pathogen in immunocompromised patients. Little is known about the mechanisms of host defence against T. asahii. We investigated the fungicidal activity of human peripheral blood monocytes and murine peritoneal macrophages against T. asahii isolates, and the effects of M-CSF on the anti-fungal activity of mononuclear phagocytes. We also established a neutropenic mouse model of disseminated trichosporonosis with T. asahii. M-CSF enhanced the phagocytic fungicidal activity of mononuclear cells, and infected mice treated with human M-CSF at 10 x 106 U/kg showed a significant improvement in survival rate, with fewer fungal colony counts in the lung compared with control mice. Mice treated with human M-CSF showed higher concentrations of tumour necrosis factor-alpha (TNF-alpha) in the lung and plasma compared with control mice. The survival rate was significantly reduced in mice treated with anti-mouse TNF-alpha. Our results showed that M-CSF enhanced the fungicidal activity of mononuclear phagocytes partly by production of TNF-alpha, and suggest that the administration of M-CSF to patients with disseminated trichosporonosis may be a useful adjunct to conventional anti-microbial therapy and prophylaxis.

Animals↗
PubMed2000

Selective solubilization of high-molecular-mass neurofilament subunit during nerve regeneration.

A reduction in neurofilament (NF) protein synthesis and changes in their phosphorylation state are observed during nerve regeneration. To investigate how such metabolic changes are involved in the reorganization of the axonal cytoskeleton, we studied the injury-induced changes in the solubility and axonal transport of NF proteins as well as their phosphorylation states in the rat sciatic nerve. In the control nerve, 15-25% of high-molecular-mass NF subunit (NF-H) was recovered in the 1% Triton-soluble fraction when fractionated in the presence of phosphatase inhibitors. After a complete loss of NF proteins distal to the injury site (70-75 mm from the spinal cord) 1 week after injury, NF-H detected in the regenerating sprouts at 2 weeks or later exhibited higher solubility (>50%) and lower C-terminal phosphorylation level than NF-H in the control nerve. Solubility increase was also apparent with L-[35S]methionine-labeled NF-H that was in transit in the proximal axon at the time of injury. The low-molecular-mass subunit remained in the insoluble fraction in both the normal and the regenerating nerves, indicating that selective solubilization of NF-H rather than total filament disassembly occurs during regeneration.

Animals↗
PubMed2000

Combination therapy for chronic Pseudomonas aeruginosa respiratory infection associated with biofilm formation.

There had been no reports of investigations into biofilms in chronic respiratory infection in vivo. Recently, we established a new murine model of chronic respiratory infection with Pseudomonas aeruginosa. In the present study, we examined the bacteriological effect of combined clarithromycin and levofloxacin against chronic respiratory infection with P. aeruginosa. Scanning electron micrograph of the surface of the catheter intubated in mouse bronchus for 7 days demonstrated in vivo formation of a biofilm containing blood cells, complex fibrous structures and bacteria. Treatment with either clarithromycin alone or levofloxacin alone had no statistical effect on the number of viable bacteria in lung. The combined use of both drugs resulted in a significant decrease in the number of viable bacteria. The present experiment demonstrates that the newly established murine model was useful to investigate the treatment of biofilm-associated chronic respiratory infection with P. aeruginosa, and combination therapy with clarithromycin and levofloxacin was effective in biofilm-associated chronic respiratory infection.

Animals↗
PubMed2000

Efficacy of FK463, a (1,3)-beta-D-glucan synthase inhibitor, in disseminated azole-resistant candida albicans infection in mice.

The efficacy of FK463, a new (1,3)-beta-D-glucan synthase inhibitor, against azole-resistant Candida albicans strains has been studied. The MIC of FK463 was lower than those of azoles and amphotericin B against CDR1-expressing C26 and CaMDR-expressing C40 strains. All mice treated with FK463 (1 mg/kg) survived disseminated murine candidiasis. The fungal burden in the kidney after 6 days was markedly reduced after therapy with FK463 and amphotericin B sodium deoxycholate, and plasma (1,3)-beta-D-glucan concentration was found to be lower in FK463-treated mice. In our study, FK463 was found to be a potent antifungal agent against disseminated infection with azole-resistant C. albicans.

Animals↗
PubMed2000

Increased chymase activity in internal thoracic artery of patients with hypercholesterolemia.

Apart from ACE, various angiotensin II (Ang II)-forming serine proteinases (eg, chymase, kallikrein, and cathepsin G) are known to exist in human tissues, but their clinical significance or the regulatory mechanisms that control their activities are not well established. A recent clinical study has shown that chymase activity was significantly increased in human atherosclerotic or aneurysmal aorta. The association between vascular Ang II-forming activities (AIIFAs) in the human internal thoracic artery (ITA) and various clinical parameters was studied with the use of ITAs obtained from 32 patients who underwent coronary artery bypass graft surgery. Total and ACE- and chymase-dependent AIIFAs in homogenates of ITAs were determined. Total AIIFA was 8.67+/-0.86 (nmol Ang II formed. min(-1). mg protein(-1) [U]), and approximately 95% of the activities were due to chymase. Serum total cholesterol level, but no other risk factors, significantly correlated with chymase- (r=0. 60, P<0.001) and ACE- (r=0.35, P<0.05) dependent AIIFAs, respectively. LDL cholesterol level was also correlated with chymase-dependent AIIFAs (r=0.47, P<0.05). Mast cells identified through the use of toluidine blue or immunohistochemical staining appeared in the adventitia but not in the intima or media of ITAs. Our results suggest that an increased plasma LDL cholesterol level may induce increased arterial chymase and ACE activity.

Aged↗
PubMed2000

Aspergillus fumigatus isolated from blood samples of a patient with pulmonary aspergilloma after embolization.

Aspergillus DNA was detected by PCR in the serum sample of a 78-year-old man and galactomannan antigen of Aspergillus by sandwich ELISA was found. However, the infiltrative hyphae were not detected by the histopathologic examination of the lung. He developed hemoptysis, which required embolization of bronchial arteries. Aspergillus fumigatus was isolated from blood samples after embolization by the lysis centrifugation method. To our knowledge, this is probably the first case in which Aspergillus spp. has been isolated from the systemic circulatory blood in a patient with pulmonary aspergilloma after embolization.

Aged↗
PubMed2000

Clinical evaluation of 61 patients with pulmonary aspergilloma.

OBJECTIVE AND METHODS: We retrospectively evaluated 61 cases with pulmonary aspergilloma representing patients admitted to Nagasaki University Hospital between January 1991 to June 1998. RESULTS: Fifty-two (85%) were males and 9 (15%) were females, aged between 14 to 80 years (average, 65 years). Forty-four (72%) patients had history of old pulmonary tuberculosis. Chest radiographs showed "fungus ball" in the cavities in 42 (67%) cases while 16 (26%) cases showed thickening of the cavity wall. Aspergillus fumigatus was isolated in 24 (39%) patients. Aspergillus antigen or antibody was positive in 8 (13%) and 43 (70%) patients, respectively. Oral itraconazole was used in 16 (26%) of patients, and surgical excision was performed in 15 (25%) patients. During hospitalization or after discharge, 19 (31 %) patients died. SUMMARY AND CONCLUSION: Pulmonary aspergilloma usually occurs in elderly patients with old tuberculosis and respiratory failure. Many cases did not respond to antifungal therapy with itraconazole or amphotericin B. Our analysis indicates that more effective and appropriate therapeutic regimens are needed for the treatment of patients with pulmonary aspergilloma.

Adolescent↗
PubMed2000

Off-pump CABG for a patient with a brain tumor.

Coronary artery bypass grafting (CABG) without cardiopulmonary bypass (off-pump CABG) was performed on a patient with a brain tumor. A patient with effort angina of the left anterior descending artery (LAD), and diagonal branch stenosis was referred to us for CABG. He had a mass lesion in the brain that was diagnosed as meningioma involving the internal carotid artery and a middle cerebral artery. To avoid brain complications, we performed off-pump CABG using the internal thoracic and radial arteries to the LAD and a diagonal branch. Off-pump CABG was an effective method to avoid brain complications for patients with a brain tumor involving cerebral vessels.

Aged↗
PubMed1999

Real-time observation of the disassembly of stable neuritic microtubules induced by laser transection: possible mechanisms of microtubule stabilization in neurites.

By dissolving the membrane with detergent perfusion, we have shown that the established neurites of dorsal root ganglion cells cultured for more than 5 days contained microtubules which persisted outside the cell for a few minutes to more than 1h [Tashiro et al., 1997: J. Neurosci. Res. 50:81-93]. To investigate their stabilization mechanism, we transected the exposed microtubules by laser microbeam irradiation and observed their length changes with video-enhanced differential interference contrast microscopy. Microtubule fragments started to shorten on both sides of the transection site. more rapidly from the newly generated plus ends than from the minus ends. The maximal rate as well as the pattern of shortening correlated with the time of transection; microtubules transected later than 30 min after membrane removal shortened at rates less than 20 microm/min and typically with intermittent pauses, while the more labile microtubules included in the earlier transections shortened continuously at higher rates. Microtubules in neurites were thus stabilized by 1) stopping disassembly at local sites including the plus ends, and 2) slowing disassembly along the length. Transection also suggested the presence of specialized points along microtubules which are involved in anchoring microtubules to the substratum. Cell Motil. Cytoskeleton 42:87-100, 1999.

Animals↗