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Biomedical subjects

M Itoh

Publications and source records attributed to M Itoh.

At least 703 records · Page 39Linked to original sources
PubMed1993

Clonal fibroblastic cell lines established from a heavily exposed atomic bomb survivor.

Two clonal fibroblast cell lines with simple chromosome aberrations-one with del(3)(p24) and the other with t(1;16)(q21;q11.2)-were established from a high dose (5.14 Gy) female atomic bomb survivor by serial culture of skin fibroblasts. These two types of clonal cells showed a more extended life span than did the cells with 44 other types of chromosome aberrations and normal cells. In addition to these results, a prominent clonal population was observed in the peripheral blood cells in this subject. It is assumed that these clonal populations arose in vivo as a result of radiation exposure to the atomic bomb.

Aged↗
PubMed1993

Enhancement of various non-specific immune effector functions in mice by local injection of aclacinomycin A adsorbed onto activated carbon particles (ACR-CH).

Local injections of aclacinomycin A adsorbed onto activated carbon particles (ACR-CH) augmented the cytotoxic activities of regional lymph node cells for 7 days. In contrast NK-activity was only slightly augmented by injections of aclacinomycin A (ACR) solution or activated carbon suspension. The effects were found in lymphocytes from all regions tested. NK-activity could only be detected when both adherent and non-adherent cells were present. The cell number of L3T4+ cells in each type of lymph node tested increased, and subset analysis of the lymphocyte subpopulations revealed an increase in the ratio of L3T4+/Lyt2+ cells, suggesting that the ACR-CH selectively increased and stimulated L3T4+ cells. Enhanced capacity of lymph node cells to produce cytokines, tumor necrosis factor (TNF) and interleukin-1 (IL-1) upon restimulation (with LPS) in vitro in the ACR-CH treated group was found. From these results, it appears that the new dosage form of aclacinomycin A, ACR-CH, with superior therapeutic efficacy against lymph node metastases, can also enhance the immune response of regional lymph node cells. The findings reported here will be valuable in the establishment of novel chemoimmunotherapeutic protocols using ACR-CH.

Aclarubicin↗
PubMed1993

Midbrain tegmentum as an intermediate relay station of the periaqueductal-facial pathway in the cat.

Iontophoretic injection of horseradish peroxidase (HRP) into the medial part of the facial nucleus resulted in retrograde labeling in the lateral midbrain tegmentum contralaterally which corresponded to the paralemniscal zone (PL). Further experiments in which HRP was injected iontophoretically into the PL revealed heavy retrograde labeling in the lateral portion of the ipsilateral periaqueductal gray (PAG). These light microscopic studies indicated the possibility of the pathway from the PAG to the facial nucleus via the midbrain PL. The electron microscopic observations were carried out on the lateral midbrain tegmentum containing the PL after kainic acid, and wheat germ agglutinin conjugated HRP injections were made into the PAG and the contralateral facial nucleus in the same animal, respectively. Although in the neuropil many degenerating PAG fibers and retrogradely labeled neurons were observed, it was of particular interest that the degenerating fibers made synaptic contacts with HRP-labeled somata and dendrites.

Animals↗
PubMed1993

Superior cervical ganglionic origin of sympathetic fibers in the facial nerve, and their preganglionic spinal inputs: a WGA-HRP study in Macaca fuscata.

The origin of sympathetic fibers in the facial nerve of Macaca fuscata was demonstrated using the HRP method. WGA-HRP injection into the facial nerve resulted in heavy labeling in the ipsilateral superior cervical ganglion. The majority of labeled neurons in the superior cervical ganglion had sizes ranging from 20 to 35 microns. In the present study it was of particular interest that labeled neurons are also found in the intermediolateral nucleus and lateral funiculus ipsilaterally at the level from the C8 to T4 spinal cord segments. Many labeled neurons in the lateral funiculus were located in close vicinity to the intermediolateral nucleus, and, characteristically, a few of these had a long dendrite extending to the lateral surface of the spinal cord. The labeling in the spinal cord appears to be caused by transneuronal transport of WGA-HRP.

Animals↗
PubMed1993

Assessment of the implantation site by transvaginal ultrasonography.

OBJECTIVE: To investigate the implantation site in a singleton pregnancy. DESIGN: Transvaginal ultrasonography (US) was performed at the mid or late follicular phase and/or at very early gestation before 6 weeks. SETTING, PATIENTS: Ultrasound monitoring was performed on 21 women with spontaneous cycles or treated by administration of 2.5 mg/d bromocriptine mesylate (Parlodel; Sando Co., Tokyo, Japan) for occulted hyperprolactinemia at the Fertility Clinic of the Department of Obstetrics and Gynecology at Gunma University Hospital. MAIN OUTCOME MEASURES: The site of the ovary with a growing follicle and/or a corpus luteum of pregnancy, and the location of a gestational sac in longitudinal and transverse views were observed. RESULTS: When ovulation occurred in the right ovary, 12 of the 14 gestational sacs were located on the right wall, 1 on the midwall, and 1 on the left wall. Ovulation in the left ovary resulted in 5 gestational sacs located in the left wall and 2 on the midwall. That is, of 21 gestational sacs, 17 were located on the ipsilateral uterine wall to the ovulating ovary, 3 on the midwall, and only 1 on the contralateral. CONCLUSION: Implantation occurs on the ipsilateral uterine wall to the ovulating ovary.

Adult↗
PubMed1993

Parapharyngeal abscess associated with the second pharyngeal pouch.

Peritonsillar or parapharyngeal abscess is not at all a rare disease. Usually the abscess is recognized as the underlying consequence of acute tonsillitis. However, the abscess may be caused by an internal fistula related to the second pharyngeal pouch. Presented here are the clinical, radiological and pathological aspects of an internal fistula with a parapharyngeal abscess related to the second pharyngeal pouch.

Abscess↗
PubMed1993

Cerebral circulatory and metabolic changes following EC/IC bypass surgery in cerebral occlusive diseases.

In order to evaluate the effect of extracranial-intracranial (EC/IC) bypass surgery for the patients with ischaemic cerebrovascular disease, fourteen patients were studied for cerebral blood flow (CBF), oxygen extraction fraction (OEF) and cerebral metabolic rate of oxygen (CMRO2) before and after EC/IC bypass using positron emission tomography (PET) and 15O steady state technique. Six patients with carotid lesion received superficial temporal artery (STA)-middle cerebral artery anastomosis, and eight patients with vertebro-basilar lesion underwent STA-superior cerebellar artery anastomosis. In both groups of patients with carotid and vertebro-basilar lesion, significant increase of CBF and decrease of OEF were observed following surgical revascularization. Especially in patients with vertebro-basilar lesion, remarkable improvements were observed not only in the cerebellum but also in the cerebral cortex. In addition, the cases with preoperative higher OEF showed marked increase of CBF and decrease of OEF. It was suggested that EC/IC bypass can be effective when pre-operative uncoupling between cerebral circulation and metabolism are marked and PET study provides useful information for selecting the appropriate candidates for EC/IC bypass surgery.

Adult↗
PubMed1993

Percutaneous transluminal angioplasty of internal carotid artery: a preliminary report of seesaw balloon technique.

Percutaneous transluminal angioplasty (PTA) has become a common neurosurgical procedure. This technique, however, has been rarely used for stenosis of the internal carotid artery because of the resultant embolization with debris following balloon manipulation. We present a case of internal carotid artery stenosis with a complaint of transient mono-ocular blindedness, whose ischaemic attack was relieved by PTA operation. In this case, we applied endovascular treatment for carotid stenosis, known as 'seesaw balloon technique', which prevented cerebral embolization with debris from the lesion. This technique may simplify the endovascular treatment for distally located carotid stenosis and shorten the operation time.

Angioplasty, Balloon↗
PubMed1993

The 220-kD protein colocalizing with cadherins in non-epithelial cells is identical to ZO-1, a tight junction-associated protein in epithelial cells: cDNA cloning and immunoelectron microscopy.

We previously identified a 220-kD constitutive protein of the plasma membrane undercoat which colocalizes at the immunofluorescence microscopic level with cadherins and occurs not only in epithelial M., S. Yonemura, A. Nagafuchi, Sa. Tsukita, and Sh. Tsukita. 1991. J. Cell Biol. 115:1449-1462). To clarify the nature and possible functions of this protein, we cloned its full-length cDNA and sequenced it. Unexpectedly, we found mouse 220-kD protein to be highly homologous to rat protein ZO-1, only a part of which had been already sequenced. This relationship was confirmed by immunoblotting with anti-ZO-1 antibody. As protein ZO-1 was originally identified as a component exclusively underlying tight junctions in epithelial cells, where cadherins are not believed to be localized, we analyzed the distribution of cadherins and the 220-kD protein by ultrathin cryosection immunoelectron microscopy. We found that in non-epithelial cells lacking tight junctions cadherins and the 220-kD protein colocalize, whereas in epithelial cells (e.g., intestinal epithelial cells) bearing well-developed tight junctions cadherins and the 220-kD protein are clearly segregated into adherens and tight junctions, respectively. Interestingly, in epithelial cells such as hepatocytes, which tight junctions are not so well developed, the 220-kD protein is detected not only in the tight junction zone but also at adherens junctions. Furthermore, we show in mouse L cells transfected with cDNAs encoding N-, P-, E-cadherins that cadherins interact directly or indirectly with the 220-kD protein. Possible functions of the 220-kD protein (ZO-1) are discussed with special reference to the molecular mechanism for adherens and tight junction formation.

Amino Acid Sequence↗
PubMed1993

Occludin: a novel integral membrane protein localizing at tight junctions.

Recently, we found that ZO-1, a tight junction-associated protein, was concentrated in the so called isolated adherens junction fraction from the liver (Itoh, M., A. Nagafuchi, S. Yonemura, T. Kitani-Yasuda, Sa. Tsukita, and Sh. Tsukita. 1993. J. Cell Biol. 121:491-502). Using this fraction derived from chick liver as an antigen, we obtained three monoclonal antibodies specific for a approximately 65-kD protein in rats. This antigen was not extractable from plasma membranes without detergent, suggesting that it is an integral membrane protein. Immunofluorescence and immunoelectron microscopy with these mAbs showed that this approximately 65-kD membrane protein was exclusively localized at tight junctions of both epithelial and endothelial cells: at the electron microscopic level, the labels were detected directly over the points of membrane contact in tight junctions. To further clarify the nature and structure of this membrane protein, we cloned and sequenced its cDNA. We found that the cDNA encoded a 504-amino acid polypeptide with 55.9 kDa. A search of the data base identified no proteins with significant homology to this membrane protein. A most striking feature of its primary structure was revealed by a hydrophilicity plot: four putative membrane-spanning segments were included in the NH2-terminal half. This hydrophilicity plot was very similar to that of connexin, an integral membrane protein in gap junctions. These findings revealed that an integral membrane protein localizing at tight junctions is now identified, which we designated as "occludin."

Amino Acid Sequence↗
PubMed1993

Promotion of cholangiocarcinogenesis in the hamster liver by bile duct ligation after dimethylnitrosamine initiation.

Administration of hepatocarcinogenic nitrosamines before or after infection with the liver fluke, Opisthorchis viverrini (OV), results in marked development of cholangiocellular and hepatocellular precancerous and cancerous lesions in the hamster liver. The promoting effects of OV are believed to be exerted either mechanically, chemically or immunologically. To test the influence of possible mechanical effects, Syrian hamsters were initiated with a single i.p. injection of dimethylnitrosamine (DMN) 20 mg/kg and subjected 2 weeks later either to a sham operation or to complete ligation of the extrahepatic bile duct to the left lateral lobe. At the end of week 40, the animals receiving DMN-initiation and ligation had a 60.9% incidence of cholangiofibrosis, 21.7% of mucous cystadenomas and 39.1% of cholangiocarcinomas, whereas the group given DMN alone only developed cholangiofibrosis, limited to 5% of the animals. In the latter case neither cystadenomas nor cholangiocarcinomas were observed. The incidence of hepatocellular nodules did not differ between the two groups and no tumorous lesions developed in either the ligated or the untreated groups without DMN pretreatment. Complete ligation of the bile duct itself led to a series of events; obstruction of bile flow being followed by dilatation, cyst formation, and necrosis of the bile duct epithelium and surrounding affected areas leading to regenerative proliferation. The results are in line with the conclusion that parasite-associated proliferation in target cell populations is, at least in part, responsible for the influence of OV on liver tumor development.

Animals↗
PubMed1993

Phasic muscle activity during REM sleep in infancy-normal maturation and contrastive abnormality in SIDS/ALTE and West syndrome.

The generation of phasic muscle activity during REM sleep is regulated by the brainstem. We proposed two sleep indices for phasic muscle activity during REM sleep, and examine their usefulness in assessing normal brainstem maturation and functional brainstem impairment during infancy. One - the dissociation index (DI) - seems to reflect maturation of the tonic inhibitory system functioning during REM sleep, and the other - % body movements in REMs bursts (%BMs-R) - to reflect that of the phasic one. In normal infants, DI showed a gradual, linear and significant increase with age, whereas %BMs-R showed a gradual and significant decrease with age. In infants with sudden infant death syndrome (SIDS) and one who had experienced apparent life-threatening events (ALTE), the DI values were lower than those in controls, although %BMs-R values were identical in the controls. In contrast, DI was variable in infants with West syndrome (WS), while %BMs-R exceeded normal values. The tonic inhibitory system seemed to be specifically involved in SIDS and ALTE, but the phasic inhibitory one in WS. Anatomical differences between these inhibitory systems are also discussed.

Journal Article↗
PubMed1993

Moyamoya disease associated with bilateral renal artery stenosis.

Recent research has suggested that an association exists between moyamoya disease and fibromuscular dysplasia which involves systemic vessels, including renal arteries. We report a 3 year old girl with moyamoya disease associated with bilateral renal artery stenosis. This case may support the common etiology of these two clinical conditions. To our knowledge this is the youngest case of moyamoya disease associated with bilateral renal artery stenosis.

Aortography↗
PubMed1993

Role of x-linked immunodeficiency (xid) and NK activity in rejection of human tumor xenotransplants in nude mice.

In order to elucidate the factors influencing the takes of human tumor xenografts in nude mice, we compared the transplantability of human tumors in nude mice with additional genetic defects in the immune system. The nude mice strains tested were classified as follows by expression of the beige gene and the x-linked immunodeficiency (xid) gene: 1) high NK nude (C57BL/6N, nu/nu), 2) low NK nude (C57BL/6 bg/bg nu/nu), 3) high NK nude with B-cell defect (CBA/N nu/nu), and 4) low NK nude with B-cell defect (NIH(S)III). Takes of human tumor xenografts including gastric carcinoma, T-cell lymphoma and B-cell lymphoma were better in nude mice with xid (CBA/N and NIH(S) III nude mice) than in nude mice without xid (B6 and beige nude mice). In addition, among the nude mice with xid expression, the takes were slightly better in nude mice with a CBA/N background than in those with a NIH(S) background. Moreover, the xenotransplantation rate in (CBA/N x C57BL/6N)F1 male nude mice with xid expression was higher than in (C57BL/6N x CBA/N)F1 males without xid expression, but did not react the same level as that in CBA/N nude. On the other hand, introduction of the beige gene into nude mice minimally improved the takes of human tumor xenografts under limited experimental conditions (inoculation of 100 x 10(5) T-cell lymphoma and 1 x 10(5) gastric carcinoma cells) despite the reduction of NK activity. In xenotransplantation of human tumors directly from patients, the take rates of the tumors were also better in CBA/N nude mice than in BALB/cA nude mice. The results in the present report confirmed the effect of xid and CBA/N genetic background on human tumor xenografts in nude mice, suggesting the existence of serum factors, possibly present in serum IgM, mediating rejection of the xenografts.

Animals↗
PubMed1993

Localization of gap junction proteins, connexins 32 and 26, in rat and guinea pig liver as revealed by quick-freeze, deep-etch immunoelectron microscopy.

By use of site-specific antibodies against synthetic oligopeptides, we examined the localizations of the gap junction proteins connexin 32 (Cx32) and connexin 26 (Cx26) in rat and guinea pig liver. Double-labeling immunofluorescence microscopy revealed that in guinea pig liver both proteins were spread throughout the liver lobules and seemed to localize together within the same gap junction plaque. In rat liver, co-localization of both Cx32 and Cx26 in the same plaques was also suggested in periportal zones. Quick-freeze, deep-etch immunoelectron microscopy showed that immunolabeling of isolated guinea pig liver gap junction plaques with either Cx32 or Cx26 antiserum yielded complete and dense antibody decoration of the cytoplasmic surface of the plaques. In isolated rat liver plaques, the cytoplasmic surfaces were densely decorated with Cx32 antiserum, whereas Cx26 labeling yielded diffuse decoration with variable intensity of the plaques. In both species we did not observe any focal or patchy clusters of the labeling in any plaques examined. Double-labeling immunoelectron microscopy confirmed that both Cx32 and Cx26 are co-localized in the same gap junction plaques. These results suggest that in hepatocytes expressing both Cx32 and Cx26, both types of gap junction proteins are not segregated but intermingle randomly within the same plaques.

Amino Acid Sequence↗
PubMed1993

Studies on pharmacological activation of human serum immunoglobulin G by chemical modification and active subfragments. IX. Anti-inflammatory activity of completely alkylated heavy chain (C.Fr.I-H).

The anti-inflammatory activity of completely reduced and carboxamide-methylated heavy chain of all disulfide bonds in human serum immunoglobulin G (IgG) (C.Fr.I-H) was investigated using some experimental inflammatory models. C.Fr.I-H significantly inhibited carrageenin-induced paw edema and pleurisy, and serotonin-induced paw edema. The carboxamide-methylated heavy chain of interchain disulfide bonds in IgG (Fr.I-H) exhibited similar inhibitory activities to C.Fr.I-H on carrageenin-induced paw edema and pleurisy, while it was ineffective on serotonin-induced paw edema. These results suggest that complete alkylation of disulfide bonds in a heavy chain caused stronger anti-inflammatory activities than partial alkylation.

Alkylation↗
PubMed1993

Studies on pharmacological activation of human immunoglobulin G by chemical modification and active subfragments. X. Effect of carboxamidemethylated Fc fragment (CM-Fc) from human immunoglobulin G on delayed type hypersensitivity.

The anti-allergic activity of the carboxyamidemethylated Fc fragment (CM-Fc) from human serum immunoglobulin G (IgG) was studied using sheep red blood cell-induced delayed type hypersensitivity in mice (SRBC-DTH). CM-Fc suppressed the DTH response when administered 30 min before, or 4 h after the SRBC challenge, but not when administered 8 h or more after the challenge. The Fc fragment showed no activity. CM-Fc administration 30 min before the challenge was unable to suppress the DTH response in the cyclophosphamide (CY)-treated mice. However, adoptive transfer of splenocytes from mice treated with CM-Fc to CY-pretreated mice caused suppression of the SRBC-DTH response. These results suggest that CM-Fc suppressed the DTH response by mediating the function of CY-susceptible cells.

Animals↗