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Biomedical subjects

M Itoh

Publications and source records attributed to M Itoh.

At least 595 records · Page 33Linked to original sources
PubMed1995

Anatomical study on valves of human facial veins.

The valves of the facial veins of 39 sides from 20 cadavers, aged 54-95 years, were investigated. Anatomical study of the valves is important, because the facial veins can be used for microvascular anastomosis in reconstruction in the head and neck. The present study confirmed that valves existed in the human facial veins, and were most frequently observed around the lower border of the mandible. When valves were classified into 5 types according to the morphology of the lobules, bicuspid valves were the most common (93.5%), followed by traced valves (4.1%), valve preparation (1.3%), and unicuspid valves (0.9%). However, no tricuspid valves were observed. Valves appeared most often (82.9%) at confluences with the facial veins. The length of valves in the trunk of the facial veins was twice the size of the inner diameter of the vessels in 78.4% of the cases. Therefore, when valves were observed at the anastomosis sites, the present results indicated that these valves could be avoided by resecting a length of about twice the inner diameter.

Aged↗
PubMed1995

Em18 and Em16, new serologic marker epitopes for alveolar echinococcosis in western blot analysis, are the only two epitopes recognized by commercially available weak positive (cut off) sera for Em2plus-ELISA.

The assay system for antibody responses against Em2, the most specific antigen for serodiagnosis of alveolar echinococcosis (AE), has been established by enzyme-linked immunosorbent assay (ELISA) but not by Western blot assay, since Em2 antigen is not protein but carbohydrate in nature. Recently we reported that previously undescribed protein epitopes, designated Em18 and Em16 due to their molecular weights, were good serologic markers for AE by Western blot analysis. It has been shown that Em18 and Em16 are the only two epitopes recognized by commercially available weak positive (cut off) sera for the Em2plus-ELISA.

Antibodies, Helminth↗
PubMed1995

Carcinoma ex pleomorphic adenoma of the soft palate.

A case of carcinoma ex pleomorphic adenoma arising in the soft palate is reported. The tumour presented had enlarged gradually over 10 years and finally occupied the oral cavity. The patient was admitted to our hospital due to disturbance of her speech and swallowing, and a sudden haemorrhage from the tumour. The initial pathological diagnosis by open biopsy was benign pleomorphic adenoma. After total resection, histological examination revealed that the tumour was composed partly of benign pleomorphic adenoma and partly of an adenocarcinomatous component. The carcinoma cells with prominent nucleoli were spheroid or polygonal in shape, and frequently formed ductal structures with areas of necrosis. Mitoses were also found. These findings showed that this tumour was a secondary carcinoma which had developed in a preexisting pleomorphic adenoma.

Adenocarcinoma↗
PubMed1995

Effect of aphidicolin on DNA synthesis in cultured human thyroid cells.

To investigate whether partial inhibition of DNA synthesis affects the growth of thyroid cells, human thyroid cells were cultured in the presence of aphidicolin for 24h. After removal of aphidicolin, the growth of thyroid cells was evaluated by [3H] thymidine uptake and analysis of cell cycle by flow cytometry. In Graves' thyroid cells, [3H] thymidine uptake and the percentage of cells in S+G2/M phase increased during 24 hours after washout of aphidicolin, whereas those were not augmented in normal thyroid cells. Thus, the acceleration of DNA synthesis occurred after the partial inhibition of it by aphidicolin in Graves' thyroid cells, but not in the normal thyroid cells. This phenomenon might, at least in part, explain the difference of growth regulation between Graves' and normal thyroid cells.

Aphidicolin↗
PubMed1995

Mechanism of chromium(VI) toxicity in Escherichia coli: is hydrogen peroxide essential in Cr(VI) toxicity?

To investigate the role of hydrogen peroxide in Cr(VI) toxicity in vivo toward bacterial cells, we examined the effect of Cr(VI), hydrogen peroxide, sodium azide, and mannitol on the viability of Escherichia coli. Bacterial cells were incubated for 1 h with shaking in the presence of Cr(VI), hydrogen peroxide, sodium azide as catalase inhibitor, and/or mannitol as radical scavenger. The colony-forming ability and double-strand DNA degradation were examined. The viability assays revealed that Cr(VI) toxicity depended on hydroxyl radicals generated in the reaction involving hydrogen peroxide and chromium. Moreover, incubation of E. coli cells with 10 mM Cr(VI) and 3 mM hydrogen peroxide caused the degradation of double-strand DNA in vivo, which was suppressed by the addition of mannitol. These results indicated that hydroxyl radicals generated in the incubation degraded DNA of E. coli cells, resulting in cell death. In the absence of added hydrogen peroxide, the intracellular concentration of hydrogen peroxide in E. coli was low (below 1 microM). A catalase-defective strain incubated in the absence of added hydrogen peroxide remained fully viable after 1 h but showed decreased viability after prolonged incubation (4-8 h). The addition of mannitol suppressed this decrease, suggesting that hydroxyl radicals may be involved in the expression of Cr(VI) toxicity even without added hydrogen peroxide.

Acatalasia↗
PubMed1995

Histamine H1 receptor occupancy in human brains after single oral doses of histamine H1 antagonists measured by positron emission tomography.

1. Histamine H1 receptor occupancy in the human brain was measured in 20 healthy young men by positron emission tomography (PET) using [11C]-doxepin. 2. (+)-Chlorpheniramine, a selective and classical antihistamine, occupied 76.8 +/- 4.2% of the averaged values of available histamine H1 receptors in the frontal cortex after its administration in a single oral dose of 2 mg. Intravenous administration of 5 mg (+)-chlorpheniramine almost completely abolished the binding of [11C]-doxepin to H1 receptors (H1 receptor occupancy: 98.2 +/- 1.2%). 3. Terfenadine, a nonsedative antihistamine, occupied 17.2 +/- 14.2% of the available H1 receptors in the human frontal cortex after its administration in a single oral dose of 60 mg. 4. There was no correlation between H1 receptor occupancy by terfenadine and the plasma concentration of the active acid metabolite of terfenadine in each subject. 5. PET data on human brain were essentially compatible with those on H1 receptor occupancy in guinea-pig brain determined by in vivo binding techniques, although for the same H1 receptor occupancy the dose was less in human subjects than in guinea-pigs. 6. The PET studies demonstrated the usefulness of measuring H1 receptor occupancy with classical and second-generation antihistamines in human brain to estimate their unwanted side effects such as sedation and drowsiness quantitatively.

Administration, Oral↗
PubMed1995

Urinary excretion of podocalyxin indicates glomerular epithelial cell injuries in glomerulonephritis.

Immunofluorescent study of urine sediments was performed to detect glomerular epithelial cell injuries using specific monoclonal antibody against podocalyxin, a glycoprotein that is prominently expressed on glomerular epithelial cells. Three kinds of structures (casts, granules and cells) were stained in urine sediments from various glomerular diseases. The presence of podocalyxin in urines was confirmed by absorption test, immunoelectron microscopy and Western blotting. Podocalyxin was detected in the urinary sediments of patients with various forms of glomerulonephritis, particularly those with acute onset. The amount of their urinary excretion apparently indicates the degree of the glomerular epithelial cell injuries in glomerular diseases.

Adolescent↗
PubMed1995

Sequential changes in the prostatic fluid level of latamoxef in patients with acute bacterial prostatitis.

The sequential expressed prostatic secretion (EPS) levels of latamoxef (LMOX) were measured in 14 patients with acute bacterial prostatitis to evaluate the diffusion of this antibiotic from the plasma into the prostatic fluid. All patients received 2 g of LMOX on the 1st, 4th, and 7th days of hospitalization. The mean LMOX level in EPS and the EPS/serum ratio were 16.4 micrograms/ml and 0.24 on the 1st day, 5.5 micrograms/ml and 0.08 on the 4th day, and 3.5 micrograms/ml and 0.04 on the 7th day, respectively. The mean value of prostatic fluid was 7.7, 7.8, and 7.8, respectively. Thus, both the EPS level of LMOX and the EPS/serum ratio decreased along with the recovery from acute bacterial prostatitis and did not correlate with the pH gradient between prostatic fluid and plasma.

Acute Disease↗
PubMed1995

Pattern of cytokine production by T cells from adolescents with asthma in remission, after stimulation with Dermatophagoides farinae antigen.

Children with asthma usually become asymptomatic by the time they reach age 20 y. To clarify the immunologic mechanisms responsible for this phenomenon, we studied patients in remission and others who still had frequent asthma attacks. Patients were grouped by clinical status, and three variables were measured: serum levels of IgE, production of IL4 and interferon (IFN)-gamma, and the activation of T cells induced by Dermatophagoides farinae (Df) antigen. Df-induced activation of T cells (as measured by antigen-induced IL2 responsiveness) or IL2 synthesis itself was induced in patients with active asthma but not in normal subjects. These responses were much weaker in patients in remission. When stimulated by Df antigen in vitro, lymphocytes from patients with active asthma produced much more IL4 than did the cells from normal subjects, and cells from patients in remission produced only a small amount. In contrast, under similar conditions lymphocytes from patients with active asthma produced less IFN-gamma than did the cells from normal subjects. Production of IFN-gamma stimulated by Df antigen was high in patients in remission but not in normal subjects. Thus, upregulated IFN-gamma production after exposure to Df antigen might reduce IL4 secretion, which would suppress IgE production and would improve clinical status. Df antigen may suppress Df-induced allergic responses in patients with asthma in remission.

Adolescent↗
PubMed1995

Cell-to-cell adherens junction formation and actin filament organization: similarities and differences between non-polarized fibroblasts and polarized epithelial cells.

Cadherin has an intimate spatial relationship with actin filaments (AF) in various types of cells, forming the cell-to-cell adherens junction (AJ). We compared the AJ/AF relationship between non-polarized fibroblasts (NRK cells) and polarized epithelial cells (MTD-1A cells). E/P-cadherin, alpha-catenin, ZO-1 and vinculin were localized with reference to AF in these cells using laser scan microscopy as well as conventional light and electron microscopy. NRK cells adhered to each other at the tips of thin cellular processes, where spot-like AJ were formed, where P-cadherin, alpha-catenin, ZO-1 and vinculin were concentrated. Some stress-fiber-like AF bundles ran axially in these processes and terminated at spot-like AJ on their tips. At the electron microscopic level these spot-like AJ were seen as aggregates of small 'units' of AJ, where AF were densely and perpendicularly associated with the plasma membrane. In MTD-1A cells, the AJ/AF relationship was investigated during the cell polarization process after replating or wounding. At the early stage, the AJ/AF relationship was quite similar to that in NRK cells. As polarization proceeded, the spot-like AJs were gradually fused side by side with the concomitant shortening of the associated stress-fiber-like AF bundles. Finally, the belt-like AJ was established, which was lined with circumferential AF bundles. The similarities and differences in the AJ/AF relationship between non-polarized fibroblasts and polarized epithelial cells are discussed.

3T3 Cells↗
PubMed1995

Spontaneous transfer of viral protein from membrane of influenza virus-infected cells to liposomes is dependent on the diameter of receiver.

Spontaneous transfer of protein from either influenza virus-infected or uninfected cells to dimyristoylphosphatidylcholine (DMPC) liposomes was examined. The amount of transferred protein of liposomes incubated with influenza virus-infected cells (I-lipo) was more than that of liposomes incubated with uninfected cells (U-lipo). The ratio of the amount of spontaneous transferred protein of I-lipo to that of U-lipo increased in proportion to the diameter of liposomes except for small unilamellar vesicles.

Animals↗
PubMed1995

Macrophage stimulation activity of the polysaccharide fraction from a marine alga (Porphyra yezoensis): structure-function relationships and improved solubility.

The polysaccharide fraction from Porphyra yezoensis (PASF) has already been shown to stimulate murine phagocytic functions in vivo and in vitro [Y. Yoshizawa et al., Biosci. Biotech. Biochem., 57, 1862-1866 (1993)]. In this study, various treatments were applied to PASF to assess its structure-function relationships. Desulfation of PASF decreased in vitro macrophage-stimulation activity, while further sulfation of PASF did not change the activity. Among 7 fractions obtained by anion-exchange chromatography of PASF, stronger activity was found in the fractions having a lower or higher sulfate content than in those having a medium sulfate content. Digests of PASF with beta-agarase showed higher activity and solubility, and lower viscosity, than undigested PASF. These results indicate that the sulfate groups in PASF, probably porphyran, contributed to the macrophage stimulating activity, although a larger number of sulfate groups did not always cause stronger activity.

Animals↗
PubMed1995

Morphological demonstration of the immune privilege in the testis using adjuvants: tissue responses of male reproductive organs in mice injected with Bordetella pertussigens.

The testis, the epididymis and the prostate are immunologically suppressed organs in which allogeneic tissue grafts can survive for a long time. In the present study, morphological features of these three organs after systemic administration of immunopotentiators was investigated in mice to determine whether or not this treatment can affect their immunosuppressive circumstances. The animals were intravenously injected with adjuvants, Bordetella pertussigens, then killed 7-10 days later for histological examination. The results showed that the testicular interstitium was completely free from leukocyte infiltration but that the accessory glands (the prostate, the coagulating gland and the seminal vesicle), the vas deferens, the epididymis and the ductuli efferentes received extravasation of leukocytes into their interstitial tissues. This indicates that the testis is resistant to leukocyte infiltration compared with the epididymis and the prostate.

Adjuvants, Immunologic↗
PubMed1995

Insulin autoimmune syndrome after the third therapy with methimazole.

In 1986, a 26-year-old female had been diagnosed as having Graves' disease and had been treated with methimazole for four months. After the treatment with propylthiouracil for another four months, she had been treated with methimazole once again. She was in complete remission for two years. She again experienced symptoms of hyperthyroidism, and treatment with methimazole was started again. On the thirteenth day after treatment, she experienced hypoglycemic attacks with skin eruption. The plasma glucose was 57 mg/dl, 125I-Insulin binding 69%, free IRI 196 microU/ml. The patient had the HLA-DRB1*0406.

Adult↗
PubMed1995

Midbrain paralemniscal projections to the facial nucleus: an anatomical and immunohistochemical study.

Serial 30 microns-thick sections through the midbrain tegmentum were stained with cresyl violet. The PL was found to be situated along the medial edge of the lateral lemniscus. The PL consisted of small- (10-15 microns) and medium-sized neurons (25-35 microns), and was the most prominent at the caudal level of the superior colliculus. In order to confirm the existence of the inhibitory paralemniscal-facial pathway, a combined HRP and immunohistochemical technique was use in the rat. This experiment revealed that 10.9% of the total number of GABA immunoreactive PL neurons also labeled with HRP after HRP injection was made in the medial part of the facial nucleus (FN). Electron microscopic observations were carried out on the medial part of the facial nucleus (FN) after kainic acid injection was made into the contralateral PL in the cat. The majority of degenerating PL fibers were ranged from 0.5 to 3.1 microns in diameter and made synaptic contacts with somata, proximal dendrites and dendritic profiles. These fibers, containing either round or pleomorphic vesicles, formed asymmetrical or symmetrical synapses. It was of particular interest in the present study that 40.7% of the total number of degenerating fibers make synaptic contacts with large dendrites more than 3.0 microns in diameter.

Animals↗
PubMed1995

Ultrastructure of spinal relay of hypoglossal afferents to the parabrachial nucleus.

Wheat germ agglutinin-conjugated horseradish peroxidase (WGA-HRP) injection into the hypoglossal nerve mainly resulted in retrograde labeling in the superior ganglia of the glossopharyngeal and vagal nerves ipsilaterally. Anterogradely labeled fibers were found in lamina I of the ipsilateral upper cervical spinal cord with a few distribution to laminae IV-V and VII-VIII. WGA-HRP injection into the PBN revealed intensive labeling of lamina I neurons of the upper cervical spinal cord ipsilaterally. These light microscopic observations appear to indicate the hypoglossal sensory inputs to the PBN through the spinal cord. In order to investigate the synaptic nature of this spinal relay, electron microscopic observations were carried out on lamina I of the first and second cervical spinal cord after cutting the hypoglossal nerve and WGA-HRP injection into the PBN in the same animal. The spinoparabrachial projection neurons were demonstrated to show a low cytoplasmic/nuclear ratio and have an oval or deeply indented nucleus with a centrally located nucleolus. Furthermore, dark and light type degenerating fibers were observed to make synaptic contacts with HRP-labeled somata and dendritic profiles.

Afferent Pathways↗
PubMed1995

Expression of the proliferative cell nuclear antigen (PCNA) in adenocarcinoma of the gallbladder, and its relationship to prognosis.

Proliferative cell nuclear antigen (PCNA) has been correlated with degree of differentiation in some tumours, but information on PCNA expression in adenocarcinoma of the gallbladder is currently limited. Therefore, we examined PCNA expression in adenocarcinoma of the gallbladder, and its relationship to prognosis. The expression of PCNA was studied by immunohistochemistry in 70 formalin-fixed, paraffin-embedded specimens of surgically removed adenocarcinomas of the gallbladder. The percentage of stained nuclei was recorded, and the PCNA-labelling index (LI) was expressed as the ratio of labelled nuclei to the total number of nuclei counted. In all histological types, the PCNA-LI in the invasive zone of the tumour was higher than that in the luminal zone of the tumour (p < 0.05). The PCNA-LI showed a stepwise increase with decreasing degrees of differentiation in both the invasive and the luminal zone of the tumour (p < 0.01). In advanced adenocarcinomas, patients whose tumours had a PCNA-LI of less than 35 in the invasive zone had significantly longer survival rates than those with PCNA-LI equal to or greater than 35 (p < 0.01). Multivariate analysis, using the Cox proportional hazards model, indicated that a PCNA-LI > or = 35 in the invasive zone of the tumour was a significantly unfavourable prognostic factor (p = 0.002). The PCNA-LI of routinely processed specimens of adenocarcinoma of the gallbladder may be helpful for the evaluation of cell proliferation and prognosis.

Adenocarcinoma↗