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Biomedical subjects

M Itoh

Publications and source records attributed to M Itoh.

At least 415 records · Page 23Linked to original sources
PubMed1998

Properties of inhibitory junctional transmission in smooth muscle of the guinea pig lower esophageal sphincter.

Inhibitory neurotransmission in guinea pig lower esophageal sphincter (LES) muscles was investigated by using electrophysiological methods. Transmural nerve stimulation (TNS) initiated an inhibitory junction potential (i.j.p.); the amplitude increased 35% by atropine (10(-6) M) and converted to a muscarinic excitatory junction potential (e.j.p.) by apamin (10(-7) M) plus Nomega-nitro-L-arginine (L-NNA, 10(-5) M). In atropinized tissue, the i.j.p. amplitude was reduced 58% by guanethidine (5 x 10(-6) M), 41% by L-NNA (10(-5) M), 57% by suramin (10(-4) M), and it was abolished by apamin (10(-7) M), suggesting that this potential was produced by ATP and nitric oxide (NO) released from adrenergic and nitrergic nerves, respectively, through the activation of Ca2+-sensitive K+ channels. Hyperpolarizations produced by ATP and NO were inhibited by apamin. The i.j.p. amplitude was reduced after desensitizing the membrane with ATP. In atropinized tissue, TNS produced a relaxation that was reduced 15% by guanethidine (5 x 10(-6) M), 50% by L-NNA (10(-5) M), and 30% by apamin (10(-7) M). Thus the LES receives cholinergic excitatory and adrenergic and nitrergic inhibitory innervations; the latter two components contribute evenly to the i.j.p. generation. The relaxation is mainly produced by NO in a membrane potential-independent way.

Animals↗
PubMed1998

Brainstem projections of sensory fibers of the lung: a horseradish peroxidase and c-fos-like immunohistochemical study in the rat.

The brainstem projections of sensory fibers of the lung were determined in the rat by using the horseradish peroxidase (HRP) and c-fos immunohistochemical methods. Wheat germ agglutinin conjugated HRP (WGA-HRP) was injected into the parenchyma of the upper lobe of the left lung. This injection resulted in anterograde labeling in the nucleus of the tractus solitarius (NTS), area postrema (AP) and external cuneate nucleus (ECu) with slightly ipsilateral predominance. It was of interest that these labeled sensory fibers are heavily accumulated in the medial subnucleus at the rostral pole of the NTS and in the commissural subnucleus at the caudal pole. In particular, labeled fibers in the medial subnucleus were characterized by division into the ventral and dorsal portions. After formalin was injected into the parenchyma of the upper lobe of the left lung, the expression of c-fos-like immunoreactivity (FOS-LI) was observed in three nuclei of the brainstem mentioned above. In addition, this experiment resulted in the expression in the ventrolateral medulla, nucleus raphe pallidus and dorsal motor nucleus of vagus nerve bilaterally. With respect to the number of the immunoreactive cells, we could draw the conclusion that the most optimum time to induce the expression of FOS-LI is between 1.5 h and 2.0 h after noxious stimuli.

Animals↗
PubMed1998

Occlusion of the femoral artery induced fos-like immunoreactive neurons in the lateral habenular nucleus projecting to the midbrain periaqueductal gray in the rat.

Wheat germ agglutinin conjugated horseradish peroxidase (WGA-HRP) injection into the midbrain periaqueductal gray (PAG) resulted in heavy accumulation of retrogradely labeled neurons in the lateral habenular nucleus (LHb) bilaterally. When the left femoral artery was persistently ligated for 2 h, the expression of Fos-like immunoreactivity (FOS-LI) was also found bilaterally in the LHb. In the present study, by combining the retrograde labeling method of injecting WGA-HRP into the PAG and the immunohistochemical staining of the FOS-LI neurons in the LHb induced by occlusion of the femoral artery, it was demonstrated that there are neurons containing both HRP labeling and FOS-LI. These neurons appeared to be located mainly in the medial part and posterior half of the LHb, and constitute about 24% of the total number of all labeled cells.

Animals↗
PubMed1998

[Clinical effects of sodium ozagrel and urokinase in patients with acute cerebral infarction in the territory of the internal carotid artery].

In this study, the clinical effects were compared between a thromboxane synthetase inhibitor (sodium ozagrel) and a thrombolytic agent (urokinase) in patients with acute cerebral infarction. The subjects consisted of 598 patients admitted on the day of the onset of the cerebral infarction in the territory of the internal carotid artery who showed a low density area on CT images within 5 days. Of these patients, 300 were treated with sodium ozagrel and classified as Group Oz, while the remaining 298 were treated with urokinase and classified as Group Ur. The results were as follows: 1. In group Oz, complete recovery of motor impairment was seen in 209 (69.7%) patients. Complete recovery within 3 weeks after onset was seen in 186 (62.0%) patients. In group Ur, complete recovery of motor impairment was seen in 175 (58.7%) patients. Complete recovery within 3 weeks after onset was seen in 120 (40.3%) patients. Therefore, a higher incidence of complete recovery of the motor impairment was noted in group Oz [p < 0.001: chi 2 test]. Similarly, complete recovery within 3 weeks after onset was more frequent in group Oz [p < 0.001: chi 2 test]. 2. In group Oz, complete recovery was made contribution statistically by Anosognosia (Ag) and unilateral neglect (UN) on admission [multivariate analysis: p < 0.01]. In group Ur, complete recovery was made contribution statistically by Ag (p < 0.01), UN (p < 0.01) and aphasia (p < 0.05). 3. Progressive stroke was observed in 29 (9.5%) patients in the group Oz and in 71 (23.0%) patients in group Ur. There was a higher incidence of progressive stroke in group Ur [p < 0.001: chi 2 test] 4. All patients with progressive stroke had initial evidence of deterioration of neurological deficits within 6 days after the onset in group Oz, and within 5 days after the onset in group Ur. The maximal period from the beginning to the end of the deterioration of neurological deficit was 7 days. 5. In group Oz, progressive stroke was only seen in 29 (29.9%) of the patients who were admitted with motor disturbances and unilateral neglect. In group Ur, progressive stroke was seen in 8 (4.3%) of the 187 patients with motor disturbances without higher cortical dysfunction, in 17 (47.2%) of the 36 patients with motor disturbances and higher cortical dysfunction without unilateral neglect and was seen in 46 (61.3%) of the patients with motor disturbances and unilateral neglect. 6. Hemorrhagic infarction was observed in 14 (4.6%) patients in group Oz and in 31 (10.0%) patients in group Ur. There was a higher incidence of hemorrhagic infarction in group Ur [p < 0.001: chi 2 test]. 7. In group Oz, there was a higher incidence of hemorrhagic infarction among patients with atrial fibrillation (Af) on the ECG [p < 0.001: chi 2 test]. Similarly, in group Ur, hemorrhagic infarction was more frequent among patients with atrial fibrillation (Af) on the ECG [p < 0.001: chi 2 test]. Therefore, sodium ozagrel was clinically more efficient and safer than urokinase in patients with acute cerebral infarction.

Adult↗
PubMed1998

Experience of ABO-incompatible living kidney transplantation after double filtration plasmapheresis.

We achieved success in ABO-incompatible renal allografting after removing anti-A and/or anti-B antibodies from the recipient's plasma using double filtration plasmapheresis (DFPP). We report here the results of our initial 2 cases. Case 1 was a 40-yr-old female whose blood group was A+. The donor was her younger brother, a 37-yr-old male, whose blood group was B+. The human lymphocyte antigens (HLAs) were one haplotype identical, and the stimulation index of the mixed lymphocyte culture (MLC-SI) was 34. Case 2 was a 28-yr-old male whose blood group was B+. The donor was his father, a 58-yr-old male, whose blood group was AB+. The HLAs were one-haplo-type identical as well, and the MLC-SI was 71. We carried out 4 sessions of DFPP pre-operatively; i.e. on days -6, -4, -2 and -1. 2.5 1 of plasma were treated with 500 ml of 4.4% plasma protein fraction in each procedure. The pre-operative target titer of anti-A/B antibody, measured by the saline tube test, was set at less than x 8. We also used 5 kinds of immunosuppressants. Cyclosporine was administered on day -2 beginning with 8 mg/kg/d, and its dose was modified according to the trough level. 500 mg of methylprednisolone were administered intravenously during the operation, and prednisolone was started on day 1 with 60 mg/d and tapered. Azathioprine was started on day -2 with 2 mg/kg/d for 7 d and 1 mg/kg/d thereafter. 5 mg/kg/d of gusperimus was given intravenously from day 0 for 5 d. 30 mg/kg/d of ALG was given intravenously from day 0 for 14 d. Along with these immunosuppressants, 0.1 mg/kg/h of nafamostat mesilate was administered intravenously from day 0 for 3 d, and 4 mg/kg/d of ticlopidine was given orally from day 3. X-Ray irradiation to the renal graft was not done. Following splenectomy standard renal allografting was performed. In Case 1, the titer of anti-B antibody was reduced from x 16 to x 4. In Case 2, the titer of anti-A antibody was reduced from x 32 to x 4. The post-operative courses of these 2 cases were satisfactory. Although our experience is limited, ABO incompatible kidney transplantation can safely be performed using DFPP.

ABO Blood-Group System↗
PubMed1998

Lesion-to-background ratio in nonattenuation-corrected whole-body FDG PET images.

UNLABELLED: The purpose of this study was to compare the diagnostic efficacy of attenuation-corrected and nonattenuation-corrected whole-body 18F-fluorodeoxyglucose (FDG) PET images to determine an adequate method that can semiquantitatively evaluate nonattenuation-corrected images. METHODS: Whole-body PET studies were performed in 24 fasting patients with various tumors (lung cancers, n = 18; mediastinal tumors, n = 4; breast cancers, n = 2) 30-40 min after a bolus injection of 18F-FDG. Transmission scans followed emission data acquisition. Reconstructed attenuation-corrected and uncorrected images were displayed simultaneously and the relative FDG uptake in lesions and corresponding background areas was evaluated by the region of interest method. Both types of images were also compared with X-CT scans and conventional nuclear medicine scans for diagnostic efficacy. RESULTS: Attenuation-corrected and uncorrected images were found to be equally sensitive for detecting lesions. There was a strong linear correlation between lesion-to-background (L/B) ratios calculated on attenuation-corrected and uncorrected images (r = 0.98; p < 0.001). Significant differences in L/B ratios between attenuation-corrected and uncorrected images were present in only 6 of 55 lesions (11%). Standardized uptake ratios (SURs) in attenuation-uncorrected images did not correlate with SURs in attenuation-corrected images nor with L/B ratios in uncorrected images. CONCLUSION: The efficacy of attenuation-uncorrected FDG PET images in evaluating tumors is similar to that using attenuation-corrected images. Uncorrected images provide not only clinically useful but also quantitative information equivalent to that provided by attenuation-corrected images. However the L/B ratio is the only available index that can be used for quantification of uncorrected images.

Breast Neoplasms↗
PubMed1998

[Prediction of survival of terminally ill cancer patients--a prospective study].

Planning effective palliative care requires accurate estimation of survival. A prospective study was performed on 150 hospice inpatients to identify prognostic factors in terminally ill cancer patients. By univariate analysis, eleven factors were found to be significantly associated with shortened survival: poor performance status, dyspnea at rest, death rattle, appetite loss, dysphagia, dry mouth, general malaise, edema, stomatitis, fever, and delirium. Multiple regression analysis showed that five factors were independent predictors of survival: performance status, dyspnea at rest, appetite loss, edema, and delirium. We discussed current problems and future directions of survival prediction for terminally ill cancer patients.

Activities of Daily Living↗
PubMed1998

[A girl with transient psychological disturbance caused by orally administered acyclovir--differentiation between acyclovir neurotoxicity and herpes simplex encephalitis].

A previously healthy 7-year-old girl suffered from oral herpetic gingivostomatitis. After four days, oral administration of acyclovir (ACV), 1,000 mg in five divided doses, was started. She became irritable and intermittently delirious next day. Laboratory tests of blood and cerebrospinal fluid (CSF) were within normal limits and EEG showed no abnormality. Brain CT and MRI demonstrated mild asymmetry of the lateral ventricle. SPECT showed low perfusion area in the bilateral thalamus. The titer of IgG and IgM against herpes simplex virus (HSV) was increased in the serum but not in the CSF. A PCR study of HSV DNA was negative in the CSF. ACV was discontinued after 5 days' administration and she recovered from neurological disorders within 48 hours. ACV neurotoxicity is self-limiting and dose-dependent. It may be distinguished from herpes simplex encephalitis by the lack of fever, headache, focal neurologic signs, and abnormal CSF and neuroradiological findings. However, when the differentiation should be difficult, we believe that the administration of ACV can be carefully continued because the potential fatality of HSE is high while ACV neurotoxicity is reversible.

Acyclovir↗
PubMed1998

[Operative results and long-term prognosis of type A acute aortic dissection].

Between 1983 and 1997, we operated upon 91 patients with type A acute aortic dissection. The dissection was localized in 22 patients and extensive in 69 patients. All patients underwent graft replacement and 61 (67%) patients underwent simultaneous replacement of ascending aorta and total aortic arch. The hospital mortality rate were 9% for the localized dissection and 21% for the extensive dissection. The actuarial survival rates in patients with localized dissection at 5 and at 10 years was 91% and 76%, whereas those in patients with extensive dissection at 5 and at 10 years was 68% and 62%. The freedom from dissection related death or reoperation in operative survivors with localized dissection at 5 and at 10 years was 100% and 83%, whereas those in patients with extensive dissection at 5 and at 10 years was 78% and 56%. The simultaneous replacement of ascending aorta and total aortic arch in patients with extensive dissection was effective to obliteration of the distal false channel, although this extended procedure has to be carefully adopted in high risk patients with associated complications such as acute dissection organ ischemia.

Acute Disease↗
PubMed1998

[Early and long-term outcome for surgical treatment of acute aortic dissection].

This study was undertaken to determine the factors that influence the final outcome after the operation of acute aortic dissection. Twenty-one patients, the median age was 59 years (range 44 to 81), were operated at acute phase in 92 admitted into our hospital during the 13-year period between May 1985 and Jan. 1998. Preoperative complications included cardiac in 5 and ruptured with shock in 7, myocardial ischemia in 3 and stroke in 4. The ascending aortic reconstruction (9, 43%), ascending aorta and arch reconstruction (7, 33%) and other procedures (4, 19%) were performed using cardiopulmonary bypass with deep hypothermia and circulatory arrest or selective cerebral perfusion. The 30-day operative deaths were 6 (29%) and 5 (24%) late death occurred. Three out of 5 were aneurysm related deaths. The cause specific survival rates were 61% at 5 years and 51% at 8 years. The multivariably determined risk factors for death were as follows (p < 0.05): preoperative FDP; bleeding volume; postoperative renal complications; postoperative stroke.

Acute Disease↗
PubMed1998

Rebamipide protects against oxygen radical-mediated gastric mucosal injury in rats.

Rebamipide, a novel antiulcer agent, has been shown to protect against gastric injury by free radicals. The effect of rebamipide was examined using two rat models of mucosal injury: the stomach was exposed to luminal perfusion of 10 mM H2O2 for 10 min or to local ischemia for 30 min. The effect of deferoxamine, a chelator of Fe3+, was also evaluated to determine whether Fe3+-mediated production of hydroxyl radicals contributed to the damage induced by H2O2. The pylorus was ligated and a double-lumen cannula was inserted into the forestomach for luminal perfusion. [51Cr]EDTA was administered intravenously and mucosal integrity was monitored by measuring blood-to-lumen [51Cr]EDTA clearance. Rebamipide reduced the increase in EDTA clearance induced by ischemia or H2O2. Furthermore, deferoxamine attenuated the H2O2-induced increase. These results suggest that rebamipide has a protective effect against oxygen radical-mediated gastric damage and that Fe3+ is involved in the H2O2-induced injury.

Alanine↗
PubMed1998

[A case of neutropenic enterocolitis in high dose chemotherapy with peripheral blood stem cell transplantation for relapsed testicular tumor].

High dose chemotherapy with peripheral blood stem cell transplantation (PBSCT) is safe and useful for the treatment of refractory or relapsed testicular tumors, but is sometimes accompanied by serious complications. We report a case of relapsed testicular tumor complicated by neutropenic enterocolitis during high dose chemotherapy with PBSCT.

Adult↗
PubMed1997

A novel control system for polymerase chain reaction using a RIKEN GS384 thermalcycler.

We have developed a novel high-throughput thermalcycler, the RIKEN GS384, which has a maximum of 1536 wells and whose temperature can be controlled accurately and simultaneously for a very small volume of a reaction mixture. In practice, the reaction is carried out using four 384-well (3.5 mm in diameter) plate formats which can be automatically moved using a robotic arm. To achieve accurate temperature control with high thermo-conductivity, we adopted Teflon-coated aluminum well plates closely sandwiched between silicon sheet-covered lids on top and a graphite sheet below. The lids were kept at a higher temperature (2 to 5 degrees C) than the reaction wells. The temperature of the 1536 sample wells was controlled accurately without temperature variability among the wells or evaporation, even for samples of very small volume (minimum 2 microliters). We also developed a new type of plate format which is similar to the 384-well place in terms of plate size, shape, and material, but which differs in the number (1536) and size (1.6 mm in diameter) of the wells. Since the amplification reactions could be done precisely as well, a total of 6144 reactions can potentially be carried out simultaneously using the GS384 thermalcycler. This is very promising for DNA microfabrication technology. This thermalcycler offers the advantage of high-throughput DNA analysis which should be useful for DNA diagnoses or for the human genome project.

Humans↗
PubMed1997

Estimation of the numerical densities of neurons and synapses in cerebral cortex.

In this paper we discuss a stereological technique, 'the unfolding method', for a quantitative study of the nervous system [1,31]. Stereology implies a geometric analysis of structures and textures, and is a method to derive directly metric properties of structures from two-dimensional sections on the basis of geometrico-statistical reasoning [36,37]. Recent advances in the stereological method allow quantitative analysis [8,19,27,32]. Images on sections provide only two-dimensional information, but the stereological method can offer three-dimensional and quantitative information [19]. The need for quantitative analysis is more important and useful in the central nervous system (CNS) than in other organs. Two functional units, neurons and synapses, are of particular interest in evaluating CNS function. Numerical densities of neurons and synapses in rat visual cortex were estimated using the unfolding method at light and electron microscopic levels, respectively. Once the numerical densities of neurons and synapses were obtained, synapse-to-neuron ratios could be calculated. The ratios are interpreted as a means to obtain an index of interneuronal connectivity [9]. The unfolding method may become a powerful strategy in neuroscience research when numerical estimates are performed in restricted areas such as cortical layers II-IV, because this method is less time-consuming than other stereological methods [6,21,22].

Animals↗
PubMed1997

A point mutation in the Sendai virus accessory C proteins attenuates virulence for mice, but not virus growth in cell culture.

A mutant Sendai virus (SevMVC), which grows much better than its progenitor virus (SeVM) in cell culture, but, in strong contrast to SeVM, is totally avirulent for mice, has been described. SeVMVC contains two amino acid substitutions relative to SeVM, namely, F170S in the C protein and E2050A in the L protein. We have examined which substitutions were responsible for the above phenotypes by exchanging the C gene of our reference strain Z with those of SeVH (another reference strain), SeVM, and SeVMVC, in turn. We have found that the F170S mutation in the CMVC protein is responsible both for enhanced replication in cell culture and for avirulence in mice. Avirulence appeared to be due to restricted viral replication primarily after day 1, implicating some aspect of innate immunity in this process. The SeV C proteins thus appear to be required for multiple cycles of replication in mice.

Animals↗
PubMed1997

Afadin: A novel actin filament-binding protein with one PDZ domain localized at cadherin-based cell-to-cell adherens junction.

A novel actin filament (F-actin)-binding protein with a molecular mass of approximately 205 kD (p205), which was concentrated at cadherin-based cell-to-cell adherens junction (AJ), was isolated and characterized. p205 was purified from rat brain and its cDNA was cloned from a rat brain cDNA library. p205 was a protein of 1,829 amino acids (aa) with a calculated molecular mass of 207,667 kD. p205 had one F-actin-binding domain at 1,631-1,829 aa residues and one PDZ domain at 1,016- 1,100 aa residues, a domain known to interact with transmembrane proteins. p205 was copurified from rat brain with another protein with a molecular mass of 190 kD (p190). p190 was a protein of 1,663 aa with a calculated molecular mass of 188,971 kD. p190 was a splicing variant of p205 having one PDZ domain at 1,009-1,093 aa residues but lacking the F-actin-binding domain. Homology search analysis revealed that the aa sequence of p190 showed 90% identity over the entire sequence with the product of the AF-6 gene, which was found to be fused to the ALL-1 gene, known to be involved in acute leukemia. p190 is likely to be a rat counterpart of human AF-6 protein. p205 bound along the sides of F-actin but hardly showed the F-actin-cross-linking activity. Northern and Western blot analyses showed that p205 was ubiquitously expressed in all the rat tissues examined, whereas p190 was specifically expressed in brain. Immunofluorescence and immunoelectron microscopic studies revealed that p205 was concentrated at cadherin-based cell-to-cell AJ of various tissues. We named p205 l-afadin (a large splicing variant of AF-6 protein localized at adherens junction) and p190 s-afadin (a small splicing variant of l-afadin). These results suggest that l-afadin serves as a linker of the actin cytoskeleton to the plasma membrane at cell-to-cell AJ.

Actins↗