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Biomedical subjects

E Ito

Publications and source records attributed to E Ito.

At least 199 records · Page 11Linked to original sources
PubMed1992

An autopsy case of renal cell carcinoma associated with extensive peliosis hepatis.

An autopsy case of renal cell carcinoma with extensive peliosis hepatis is reported. The patient was a 34-year-old female, who had had a left nephrectomy for renal cell carcinoma but died of multiple metastases one year and 4 months after surgery, despite chemotherapy and interferon treatment. At autopsy, the liver was enlarged markedly with multiple metastatic nodules and the non-neoplastic hepatic parenchyma had a spongy appearance, due to diffusely scattered, blood-filled cystic lesions. Histological examination showed the oval to irregular shaped blood-filled spaces were lined by hepatic cell cords and located mainly in the periportal area. In addition, almost all of the sinusoids were dilated and communicated with the cystic blood-filled spaces, which also communicated directly with branches of the portal veins at various levels. Several interlobular portal branches were obstructed. The causative mechanism of peliosis hepatis has yet to be elucidated, although some causative conditions have been proposed. In this case, renal cell carcinoma may have caused the sinusoidal dilatation and the vascular changes in the portal areas, such as obstruction of terminal portal branches, may have contributed to its formation.

Adult↗
PubMed1992

Detection of genomic sequences of respiratory syncytial virus in otitis media with effusion in children.

The reverse transcriptase-polymerase chain reaction and the nested polymerase chain reaction were used for detection of respiratory syncytial virus (RSV) sequences in middle ear effusions collected from children with otitis media. Sequences of RSV were detected in 21 of 34 samples tested. These samples were collected during and/or after natural outbreaks of RSV infection in the community. In those patients from whose nasopharynges RSV was isolated, the viral sequences were highly detectable (75%) in the effusions. These observations suggest RSV as an important factor in the pathogenesis of otitis media with effusion.

Base Sequence↗
PubMed1992

Light and electron microscopic observation of experimental palytoxin poisoning in mice.

The effects of palytoxin on young male ICR mice were compared with the combined effects of palytoxin and ouabain or those of several cations as well as the effects of potassium. The target organs of palytoxin were the heart, kidney, pancreas, small intestine and liver. Pathomorphological changes of the heart induced by palytoxin were similar those of a lethal dose of KC1. However, the KC1-treated animals did not show any changes in the kidney. Mice given ouabain at doses up to 5 mg/kg also showed similar injuries in proximal as well as distal convoluted urinary tubules, while the heart of mice given ouabain at the same doses showed no discernible morphological changes. Ouabain 5 mg/kg did not influence the severity of injuries both in the heart and kidney induced by palytoxin at 4 micrograms/kg. Therefore, it may be assumed that palytoxin poisoning is a symptom-complex of hyperkalemia and causes a profound inhibition of Na+, K(+)-ATPase.

Acrylamides↗
PubMed1991

An approach to imaging of living cell surface topography by scanning tunneling microscopy.

Since a scanning tunneling microscope (STM) was developed, an observation of living cell surface has been one of the final aims in the biological application of STM. By developing a new style of STM which was combined with an optical microscope and with a novel system for the centering of both images, we successfully got the STM images of living cell surface of T24 cells (human bladder cancer cell line) and CHO cells (Chinese hamster ovary fibroblast) cultured on highly oriented pyrolytic graphite under the appropriate condition (V greater than 8.0 V, I less than 0.2 nA). Unexpectedly, the living T24 cell showed a slightly uneven surface with a steep foot slope. The CHO cell showed more rough surface with steeper slope of cell foot. Although the STM system had a fine spatial resolution less than 3 nm, the profile of living cell surface covered with electrolyte was clear only when the scanning area was more than 10 microns square.

Animals↗
PubMed1991

Resistance of Histoplasma capsulatum to killing by human neutrophils. Evasion of oxidative burst and lysosomal-fusion products.

The basis for resistance of yeast form of Histoplasma capsulatum to antifungal activity of human neutrophils was studied. In limiting dilution assays and short term coculture assays human neutrophils were ineffective in killing H. capsulatum whereas Candida albicans was readily killed. By contrast, in a cell free hydrogen peroxide-peroxidase-halide system H. capsulatum was as sensitive to killing as C. albicans. Moreover, lysate of human neutrophils effectively substituted for horse-radish peroxidase in a cell free system for killing H. capsulatum. H. capsulatum elicited significant products of the oxidative burst in human neutrophils as detected by luminol-enhanced chemiluminescence. However, the response was two-fold less (p less than 0.05) than that induced by C. albicans. Transmission electron microscopy studies showed that phagosome-lysosome fusion took place when neutrophils phagocytosed C. albicans or H. capsulatum. Taken together, these findings indicate that, even though H. capsulatum elicits an oxidative burst and phagosome-lysosome fusion within the phagosome, it is capable of evading damage in short term assays.

Cells, Cultured↗
PubMed1991

Light and electron microscopic studies of pathologic changes induced in mice by ciguatoxin poisoning.

Acute poisoning induced by ciguatoxin or ciguatoxin-4c in male ICR mice was examined by light and electron microscopy. Target organs were the heart, medulla of adrenal glands, autonomic nerves and penis. There were no significant differences between the toxicity of ciguatoxin and ciguatoxin-4c. Either i.p. injection or oral administration (0.7 micrograms/kg) resulted in marked swelling and focal necrosis of cardiac muscle cells and effusion into the interstitial space of the heart. Degeneration of cells in the medulla of the adrenal glands was also observed. Continuous erection of the penis was observed in about 15% of the mice suffering from ciguatoxicosis. Although severe diarrhea was brought about by the administration of these phycotoxins, no morphological alterations were seen in the mucosa and muscle layers of the small intestine except in autonomic nerve fibers and synapses. Atropine suppressed the symptoms of diarrhea but had no effect on the injury to the cardiac muscle. Reserpine aggravated the clinical signs and pathological findings. Guanethidine and 5-hydroxy dopamine as well as those undergoing bilateral adrenalectomy had no significant effects on the ciguatoxicosis.

Adrenal Medulla↗
PubMed1991

Developmental assembly of calcium-mobilizing systems for excitatory amino acids in rat cerebellum.

The postnatal development of calcium-mobilizing systems was studied by both microfluorometric imaging analysis of Ca2+ on living rat cerebellar slices and immunohistochemical labeling of phosphatidylinositol 4,5-bisphosphate (PIP2) and inositol 1,4,5-trisphosphate binding protein (IP3BP) in fixed rat cerebellum. Stimulation with quisqualate (QA) or N-methyl-D-aspartate (NMDA) enhanced the Ca2+ level only diffusely on postnatal day (PND) 3, but more discretely on PNDs 7 and 15. On PND 21, QA-induced responses were localized in the molecular layer especially, but not in the granular layer. By contrast, NMDA mobilized Ca2+ prominently in the granular layer, but only weakly in the molecular layer. Localized expression of PIP2 in the molecular layer paralleled QA-induced Ca2+ mobilization, but IP3BP was expressed more diffusely. The present study offers the first direct evidence that PIP2, but not IP3BP, is essential for QA-induced Ca2+ mobilization in the cerebellar cortex.

Amino Acids↗
PubMed1991

A 'macro' image analysis of fura-2 fluorescence to visualize the distribution of functional glutamate receptor subtypes in hippocampal slices.

The distribution of functional glutamate receptor subtypes was visualized as regional changes in intracellular Ca2+ concentration induced by administration of a specific agonist for each subtype. An image of the fura-2 fluorescence from a whole hippocampal slice was directly excited at 340 or 380 nm through an optical fibre and observed via a low-magnification objective lens (x4). A heterogeneous distribution of N-methyl-D-aspartate (NMDA) and non-NMDA subtypes was demonstrated by the ratio of fluorescence intensities before and after administration of each agonist. This 'macro' image analysis can reveal distributions of multiple functional receptors in a living brain slice.

Animals↗
PubMed1991

[Detection of RS viral sequences in otitis media effusion from children].

The role of respiratory syncytial virus (RS virus) in otitis media with effusion was studied. Reverse transcriptase-polymerase chain reaction (RT-PCR) and nested polymerase chain reaction (Nested PCR) were used to provide accurate methods for detection of RS viral sequences in the otitis media effusion from children. We could find RS viral sequences in 10/12 samples tested which had been collected during and even after natural outbreak of RSV in the community. These observations suggest RS virus as an important factor in the pathogenesis of otitis media with effusion. The disturbance of the local humoral and cell-mediated immune response in the middle ear accompanied with RS virus infection may lead to the development of infection-induced inflammation and ventilatory compromise, development of suppurative and effusion, multiplication of low virulence pathogens and subsequent development of mucosal damage.

Base Sequence↗
PubMed1991

Conformational change accompanying formation of oligomycin-induced Na(+)-bound forms and their conversion to ADP-sensitive phosphoenzymes in Na+,K(+)-ATPase.

Oligomycin reduced the fluorescence intensity of an N-(p-(2-benzimidazoly)phenyl) maleimide (BIPM) probe at Cys-964 of the alpha-chain of pig kidney Na+,K(+)-ATPase with increase in the concentration of Na+ with a Hill coefficient of nh = 0.77 with Kh = 231 mM. The maximum fluorescence decrease was around 80% of the value observed after accumulation of ADP-sensitive phosphoenzyme (E1P) in the presence of 2 M Na+. The addition of Mg2+ and ATP with Na+ or choline chloride to give the same final ligand concentration to the Na(+)-enzyme-oligomycin complex formed with 16 mM Na+ + 1,984 mM choline chloride or 2 M Na+ induced rapid phosphorylation (20 or 21/s) and slower fluorescence decrease (12.1 +/- 1.2 or 10.1 +/- 3.2/s). These additions to the Na(+)-enzyme complex formed under the former or the latter conditions induced slow phosphorylation (13/s) prior to a much slower fluorescence decrease (3.4 +/- 0.3 or 8.6 +/- 0.7/s). The addition of Ca2+ and ATP to these enzyme complexes induced rapid fluorescence changes (21-11/s) followed by one order of magnitude slower rates of phosphorylation (1.5-1.3 s). These data suggest that the decrease in BIPM fluorescence induced by ATP with Ca2+ or with Mg2+, reflects the change of the Na+ binding state before or after the formation of E1P, respectively.

Adenosine Diphosphate↗
PubMed1991

[Topographic correlation between basilar artery occlusion and cerebellar involvement--a clinicopathological study].

Nineteen patients (15 men, 4 women) with occlusion of the vertebrobasilar artery were studied in order to identify possible pathomechanism and to define the site of arterial occlusion and the topography of ischemic lesion of the cerebellum. Their mean age at onset was 66.7 years and the final clinicopathological diagnosis were thrombosis of the basilar artery (BA) in 15 patients and embolism in 4. The occlusion of the BA was contiguous to that of the vertebral artery in ten patients. Of these, the occlusion was localized to the caudal portion of the BA in two, to the middle portion in six, and extended to the rostral portion in two. In eight patients, the arterial occlusion was restricted to the BA. Occlusions of the middle portion were observed in four and that of rostral portion in two; in the other two patients, the whole BA was occluded. In one patient, there was no occlusion in the vertebro-basilar artery at the postmortem examination, but infarctions of the base of pons, bilateral cerebellar hemispheres and occipital lobes were confirmed, suggesting recanalization of the occluded BA. Cerebellar lesions were observed in all nineteen patients. Involvements of the area supplied by the superior cerebellar artery (SCA) were found in seventeen, while that of the posterior inferior cerebellar artery (PICA) only in ten. Eight patients had cerebellar lesions supplied by both SCA and PICA. These facts suggest that cerebellar lesions are rather frequent and the SCA areas are more involved than those of the PICA in fatal patients with occlusion of the BA.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

[Clinical study of amaurosis fugax].

Nineteen cases of amaurosis fugax (AF) were analyzed in clinical study undertaken to address the problem of its pathogenetic mechanism. This series comprised 10 male and 9 female with an age range of 26-77 years. In 8 cases, AF was the only clinical manifestation, while in the other 11, AF was accompanied by hemispheric TIA. The attack lasted for a few to 15 minutes on most occasions, occurring on the left side in 7 cases and on the right in 12 cases. On the basis of cerebral angiographic findings and findings on transcranial Doppler blood velocity measurements (TCD), these cases were classified into 4 types of different etiology, i.e. (Group A) micro-embolus via internal carotid artery origin--7 cases (5 with stenosis at the level of siphon, 2 with stenosis of the ophthalmic artery); on TCD the direction of blood flow in ophthalmic artery was normal (forward flow) in 5 cases and antiplatelet therapy proved effective in 4 cases, (Group B) micro-embolus derived via the external carotid artery--5 cases (3 with complete occlusion of internal carotid artery at its origin, 2 with severe stenosis there of); TCD showed blood flow in the ophthalmic artery to be in a direction opposite to the normal (away flow) in 3 cases and 3 cases responded favorably to antiplatelet therapy, (Group C) cerebral hemodynamic crisis--3 cases (severe cardiac hypofunction following myocardial infarction, orthostatic hypotension, and elongation of internal carotid artery), and (Group D) unknown etiology--4 cases; cerebral angiography revealed no abnormalities, suggesting involvement of other factors than cerebrovascular agents.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

[Infiltration and activation of eosinophils during the late phase response in subjects with nasal allergy--from a study of nasal lavage fluid].

On fourteen volunteers with Japanese cedar pollinosis, nasal lavage and the determination of nasal airway resistance (NAR) were carried out periodically for twelve hours after an antigen challenge using antigen disk. The percentage of EG2 positive eosinophils, the number of activated eosinophils (EG2 positive eosinophils) and the amount of ECP in each sample of nasal lavage fluid were determined. 1. The percentage of activated eosinophils increased during the late phase compared with that before the challenge and during the early phase. The number of activated eosinophils and the amount of ECP increased during both phases, but more markedly during the late phase. 2. The number of activated eosinophils and the amount of ECP were compared between the group with late phase response and that without a marked late response. Both the number of activated eosinophils and the amount of ECP showed a tendency to increase in the positive group. 3. There was a statistically significant correlation between the percentage of increase in NAR and the number of activated eosinophils. The correlation coefficient during the late phase was considerably higher than in the early phase. From these findings, the increased number of activated eosinophils observed during the late phase response is assumed to have a significant relationship with increased NAR and also the hyperreactivity of nasal mucosa.

Adult↗