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Biomedical subjects

K Morimoto

Publications and source records attributed to K Morimoto.

At least 217 records · Page 12Linked to original sources
PubMed1997

Risk factors for sensitisation to methyltetrahydrophthalic anhydride.

OBJECTIVES: To examine an association between specific IgE to methyltetrahydrophthalic anhydride (MTHPA) and exposure time, atopic history, smoking habits, and total IgE concentrations. METHODS: A cross sectional survey was carried out on a population of 148 workers from two condenser plants using epoxy resin with MTHPA, an acid anhydride curing agent known to cause allergy. RESULTS: Using a Pharmacia CAP system with a MTHPA human serum albumin conjugate, specific IgE antibody was detected in serum from 97 (66%) out of the 148 workers exposed to MTHPA. Stepwise multiple linear regression analysis showed a striking relation between log concentrations of specific and total IgE (P < 0.0001). Furthermore, when the workers were divided into two groups according to a cut-off point (100 IU/ml) between low and high total IgE, current smoking was significantly (P = 0.025) associated with specific IgE production only in the group with low total IgE (< 100 IU/ml). CONCLUSIONS: Smoking is the most significant risk factor for raising specific IgE to MTHPA in the group with low total IgE concentrations.

Adult↗
PubMed1997

Cellular localization of mRNAs for prostaglandin E receptor subtypes in mouse gastrointestinal tract.

Regional and cellular distribution of mRNAs for prostaglandin E (PGE) receptor subtypes was investigated in the mouse gastrointestinal tract by in situ hybridization. Strong signals for EP1 transcripts were detected in cells of the muscularis mucosae layer, especially in the body of the stomach. Intense signals for EP3 transcripts were detected in neurons of the myenteric ganglia throughout the tract. Moderate EP3 mRNA expression was also observed in fundic gland epithelial cells, except for surface mucous cells in the stomach. Expression of EP4 mRNA was moderate in surface epithelial cells of the corpus and in glands from the surface to the base of the antrum. Strong EP4 signals were observed in the epithelium in the duodenum, jejunum, and ileum. In the ileum, signals were only observed in the upper part of the villi. However, no or weak signals for EP2 transcripts were detected. These findings suggest that PGE2 modulates various gastric or intestinal functions via at least three different PGE receptors.

Animals↗
PubMed1997

'Distinct cellular localization' of the messenger ribonucleic acid for prostaglandin E receptor subtypes in the mouse uterus during pseudopregnancy.

As an initial step to clarify the mechanisms of various uterine actions of PGE2, expression patterns of the messenger RNAs (mRNAs) for four subtypes of PGE receptors, EP1, EP2, EP3, and EP4, were investigated in the mouse uterus during pseudopregnancy. Relative expression levels were investigated by Northern blot analysis of mRNA levels in uteri obtained on days 0, 1, 3, 5, 7, and 9 of pseudopregnancy (day 0 = 48 h after PMSG injection), and cellular localization was determined by in situ hybridization in uteri obtained on days 0 and 5. EP2 mRNA was specifically expressed on day 5, and its expression was confined to the luminal epithelium. On the other hand, the level of the EP3 mRNA expression progressively increased until day 5. Cell populations expressing the EP3 mRNA were confined to the longitudinal smooth muscle on day 0, but they changed to the circular smooth muscle on day 5. The expression level of EP4 mRNA was low on days 0 and 1, but it became high on days 3 and 5. On day 0, EP4 mRNA was localized to the luminal epithelium. On day 5, diffuse, but significant, EP4 expression was observed over the endometrial stroma and epithelium. No EP1 mRNA signals were observed. Transient expression of EP2 on day 5 of pseudopregnancy in the luminal epithelium suggests its involvement in blastocyst implantation signaling. EP4 in the endometrial stroma is suggested to be involved in decidual transformation of the stromal cells, whereas EP3 in the myometrium is believed to be involved in regulation of myometrial activity.

Animals↗
PubMed1997

[Analysis of flushing response to alcohol and drinking behavior in Japanese male students].

The purpose of this study is to clarify the relationship between hereditary predisposition and social-psychological factors in terms of drinking behavior of Japanese male students. The subjects were 123 male students who belonged to athletic clubs of K university in 1993. Regular drinking was evaluated as "drinking at home or with intimate friends" and party drinking as "drinking at club parties". On the two drinking occasions, the frequency and amount of drinking, and social drinking behavior were evaluated. Problem drinking behavior was investigated by a modified version of Aoyama's questionnaire (1984). Low Km aldehyde dehydrogenase (ALDH2) activity was evaluated by the facial flushing response to alcohol and the ethanol patch test. Evaluable results of the ethanol test as well as replies of the questionnaire were obtained from 109 students. Twenty-three students positive for both the facial flushing response to alcohol and the ethanol patch test were considered to be flushers, and 42 negative for both to be non-flushers. The non-flushers consumed a higher amount of alcohol than the flushers did on drinking occasions at home or with intimate friends. The number of problem drinking behavior items in the non-flushers was significantly higher than that in the flushers and increased with the amount and frequency of drinking. The ratio of students who had inappropriate drinking motivations, began to drink by themselves, or continued to offer alcohol to drinkers showing flushing even when they declined it, was significantly higher in the non-flushers than in the flushers. In addition, non-flushers showing such social drinking behavior drank more than those not showing such behavior. The frequency of positive or inappropriate drinking behavior was significantly lower in the flushers than in the non-flushers. However, the amount and frequency of drinking and problem drinking behavior were similar in the flushers and non-flushers. These results indicate that social drinking behavior of non-flushers influences not only themselves but also other drinkers, and that drinking of flushers is strongly influenced by social factors.

Adult↗
PubMed1997

Association of expression of mRNA encoding the PGF2 alpha receptor with luteal cell apoptosis in ovaries of pseudopregnant mice.

The relationship between the expression of mRNA encoding the prostaglandin F2 alpha (PGF2 alpha) receptor and luteal cell apoptosis as determined by oligonucleosome formation was determined in mouse corpora lutea on days 2 (early phase), 6 (mid-phase), and 11 and 13 (late phase) of pseudopregnancy. No signals for mRNA encoding the PGF2 alpha receptor were detected in the ovary as shown by RNA blot analysis of pregnant mares' serum gonadotrophin (PMSG)-treated mice. The expression of the mRNA that could be detected in the corpora lutea on day 2 after hCG treatment was low, but it was increased on day 6 and reached a plateau on days 11 and 13. On days 11 and 13, in situ hybridization signals for mRNA encoding the PGF2 alpha receptor were localized to large luteal cells of the corpora lutea, especially the cells in the superficial layer. However, ethidium bromide staining revealed marked oligonucleosome formation in the corpora lutea on days 11 and 13. Similarly, positive signals of in situ nick-DNA-end labelling were also detected in the corpora lutea on days 11 and 13. Analysis of the adjacent sections of the corpora lutea on day 13 showed that both signals for DNA strand breaks and mRNA encoding the PGF2 alpha receptor were co-expressed in the corpus luteum. These results suggest that apoptosis during structural luteolysis closely associates with the increased expression of mRNA encoding the PGF2 alpha receptor in luteal cells of pseudopregnant mice.

Animals↗
PubMed1997

Effect of active oxygen radicals on protein and carbohydrate moieties of recombinant human erythropoietin.

Our previous study showed that active oxygen radicals generated from a Fenton system and a xanthine plus xanthine oxidase system caused serious loss of in vivo bioactivity of recombinant human erythropoietin (EPO), a highly glycosylated protein. In the present study, we characterized the oxidative modifications to the protein and carbohydrate moiety of EPO, which lead to a reduction of its bioactivity. In vitro bioactivity was reduced when EPO was treated with oxygen radicals generated from a Fenton system in the presence of 0.016 mM H2O2, and the reduction was directly proportional to the loss of in vivo bioactivity. SDS-PAGE analysis showed that dimer formation and degradation was observed under more severe conditions (Fenton reaction with 0.16 mM H2O2). The tryptophan destruction was detected at 0.016 mM H2O2 and well correlated with the loss of in vitro bioactivity, whereas loss of other amino acids were occurred under more severe conditions. Treatment with the Fenton system did not result in any specific damage on the carbohydrate moiety of EPO, except a reduction of sialic acid content under severe condition. These results suggest that active oxygen radicals mainly react with the protein moiety rather than the carbohydrate moiety of EPO. Destruction of tryptophan residues is the most sensitive marker of oxidative damage to EPO, suggesting the importance of tryptophan in the active EPO structure. Deglycosylation of EPO caused an increased of susceptibility to oxygen radicals compared to intact EPO. The role of oligosaccharides in EPO may be to protect the protein structure from active oxygen radicals.

Amino Acids↗
PubMed1997

Specific antibodies against methyltetrahydrophthalic anhydride and risk factors for sensitization in occupationally exposed subjects.

OBJECTIVES: Occupational exposure to methyltetrahydrophthalic anhydride (MTHPA) from an epoxy resin was studied to evaluate the nature of reported ocular and nasal complaints and some risk factors for sensitization. METHODS: Seventy-three current and 22 former workers underwent a questionnaire survey and serologic investigations. Total and MTHPA-specific immunoglobulin (Ig)E levels were measured by means of a Pharmacia CAP system, and MTHPA-specific immunoglobulin (Ig)E levels were measured by enzyme immunoassay. RESULTS: Forty-six (63%) of the currently exposed workers has positive MTHPA-specific IgE, and no significant difference was found between those continuously or intermittently exposed (58% and 71%, respectively). Work-related ocular or nasal symptoms were significantly associated with specific IgE but not with specific IgG4. This finding indicates that there is an IgE-mediated mechanism in most cases of work-related symptoms associated with MTHPA exposure. The total IgE levels were significantly (P < 0.005) higher in the specific IgE-positive workers than in the specific IgE-negative workers (geometric mean 101 IU/ml and 44.8 IU/ml, respectively). Multiple logistic regression analysis also revealed that the group with high total IgE levels (> or = 80 IU/ml) had a significant relative risk (RR 4.7) of producing MTHPA-specific IgE as compared with the group with low total IgE levels (< 80 IU/ml). CONCLUSIONS: These results show that MTHPA has a high sensitizing ability and that a high total IgE level is the most significant risk factor for workers exposed to MTHPA. However, to evaluate conclusively the effect of high total IgE levels on sensitization, further prospective studies are necessary.

Adult↗
PubMed1997

[Bacteria isolated from surgical infections and their susceptibilities to antimicrobial agents. Special references to bacteria isolated between July 1995 and June 1996].

Isolated bacteria from infections in general surgery during the period from July 1994 to June 1995 were investigated in a multicenter study in Japan, and the following results were obtained. One hundred and sixty-four strains were isolated from primary infections, and 202 strains were isolated from postoperative infections. From primary infections, anaerobic Gram-positive bacteria were predominant, while from post operative infections, aerobic Gram-positive bacteria were predominant. Among aerobic Gram-positive bacteria, the isolation rate of Enterococcus faecalis was the highest, followed by that of Staphylococcus aureus from postoperative infections. Among anaerobic Gram-positive bacteria, the isolation rate of Peptostreptococcus spp. was the highest from both types of infections. Among anaerobic Gram-negative, Escherichia coli was the most predominantly isolated from primary infections, followed by Klebsiella pneumoniae and Pseudomonas aeruginosa in this order, and from postoperative infections, P. aeruginosa was the most predominantly isolated, followed by Enterobacter spp. and Klebsiella spp. Among anaerobic Gram-negative bacteria, the isolation rate of Bacteroides fragilis group was the highest from both types of infections. We noticed that MICs of cefazolin against three out of 23 strains of E. coli were higher than 100 micrograms/ml. Among anaerobic bacteria, there were many resistant strains against penicillins and cephems with MICs higher than 100 micrograms/ml, and the same trend was observed among other Bacteroides spp. and Prevotella spp.

Bacterial Infections↗
PubMed1997

[Three cases of malignant lymphoma that developed from the chest wall].

Chronic tuberculous pyothrax and the development of non-Hodgkin's lymphoma (NHL) on the chest wall are believed to be closely related. We encountered three patients with NHL involving the chest wall in whom the tumor may have had a different origin Patient 1: A 65-year-old man with a history of pulmonary tuberculosis and right-sided pyothrax at the age of 28 years was found to have a tumor on the right sided of the chest wall, and NHL was diagnosed. Patient 2: A 65-year old woman with a history of right-sided tuberculous pyothrax at the age of 2 years had a left-sided chest-wall tumor, and NHL was diagnosed. Patient 3: A 78-year-old man with a history of tuberclous pleuritis on the left side at the age of 77 years was found to have a left-sided chest-wall tumor, and NHL was diagnosed. In patients 1 and 2, the Epstein-Barr virus was found in tissue specimens by in situ hybridization. These findings suggest that chronic tuberculous pyothrax and the development of NHL on the chest wall were not closely related in these patients, and that the Epstein-Barr virus may play an important role in the development of NHL on the chest wall after tuberculous pyothrax.

Aged↗
PubMed1997

[Isolation rate of Enterococcus spp. from surgical infections and their susceptibilities].

Enterococcus spp. isolated from surgical infections during the period from July 1982 to June 1995 were investigated in a multicenter study involving 19 hospitals in Japan, and the following results were obtained. 1. Though the isolation rate of Enterococcus faecalis and other Enterococcus spp. were not high from primary infections, and from postoperative infections the isolation rate of other Enterococcus spp. was also low, the isolation rate of E. faecalis was highest from postoperative infections after 1993. 2. Vancomycin (VCM) showed strongest activity against E. faecalis, and followed by those of ampicillin (ABPC), imipenem. levofloxacin (LVFX) and meropenem in this order. Against other Enterococcus spp., VCM showed strongest activity, and followed by those of ABPC and LVFX. There were no resistant strains against VCM.

Ampicillin↗
PubMed1997

[Successful treatment with intermittent administration of etoposide for an adult case with recurrent hemophagocytic syndrome, developed in association with chronic EB virus infection related lymphoid hyperplasia in the small intestine].

A 28-year-old man complaining of melena accompanied by high grade fever was previously operated on for two small ulcerative, infiltrative lesions of the small bowel at another hospital in April, 1992. In the resected small intestines an immunohistochemical study was positive for EBV encoded RNA (EBER). It is assumed that Epstein-Barr (EB) virus infection has contributed to the small bowel lesions. In March, 1993, he was diagnosed as having chronic EB virus infection. In October, 1993, he was transferred to our hospital for further examination of high grade fever, rapidly worsening thrombocytemia and severe liver disfunction. Mature histiocytes with hemophagocytosis were detected in the bone marrow and he was diagnosed as having hemophagocytic syndrome (HPS) due to reactivation of chronic EB virus infection. Although treatment by corticosteroids, acyclovir and gamma globulin was not effective administration of etoposide induced remission of the disease. In December, 1993 and January, 1994 HPS recurred, but etoposide was again effective in alleviating the disease. To prevent recurrence of HPS after we discharge the patient, intermittent administration of small doses of etoposide was started. Since then HPS has not recurred, and the drug was eventually discontinued in November, 1995. Our case suggested that Etoposide could change the fulminant course of EB virus-associated HPS and that it is effective to sustained remission.

Adult↗
PubMed1997

[Surgical results of postinfarction ventricular septal perforation: operative planning using "endocardial patch repair with infarct exclusion"].

Between 1983 and 1996, twenty-two consecutive patients underwent surgical repair for postinfarction ventricular perforation (VSP). Overall hospital mortality was 31.8% in the reviewed group. 15 patients were operated upon within two weeks of onset of VSP and hospital mortality was 27.3% in this group. The earlier operation might provide more favorable results in the surgery of VSP. When the preoperative coronary angiography revealed multivessel disease, concomitant myocardial revascularization was performed. In recent 2 cases, we employed the new technique introduced by Komeda and David for the reconstruction of the left ventricule using a single pericardial patch. We found this new technique had many advantages over traditional "Daggett's method". Better operative results could be expected with this technique.

Aged↗
PubMed1996

Possible prevention of postangioplasty restenosis by ascorbic acid.

In this preliminary study to assess the possibility of using ascorbic acid to prevent post-percutaneous transluminal coronary angiography (PTCA) restenosis, the incidence of restenosis was significantly less in 50 patients receiving 500 mg/day of oral ascorbic acid than in 51 control patients. Thus, ascorbic acid, a potent natural antioxidant, appeared to be possibly effective in attenuating post-PTCA restenosis.

Adult↗
PubMed1996

Characterization of epileptiform field potentials recorded in the in vitro perirhinal cortex of amygdala-kindled epileptogenesis.

The perirhinal cortex (PRC) has recently been reported that the excitatory role of this area is important for the generation and the propagation of kindled seizures. In the present study, we investigated the extracellular electrophysiological properties of the circuitry which contribute to the propagation of seizures in the PRC, and examined the hypothesis that amygdala-kindling changes the electrophysiological nature of the rat PRC slice in vitro. Field potentials elicited in the PRC had extended duration (> 200 ms, most approximately equal to 1 s) with overlying spike components. The potentials showed strong synchronizing effect governed by an all-or-none rule. Although spontaneous epileptiform discharges that were equivalent in appearance to synaptically-activated field potentials were observed in the PRC of both amygdala-kindled and control rats, the number of slices showing spontaneous activity was significantly larger in the kindled group than in the control group (chi 2-test, P < 0.01). The occurrence of tetanus-induced afterdischarges in kindled rats was significantly higher than in control rats (chi 2-test, P < 0.01). The afterdischarge durations of control slices were generally short and the afterdischarges did not consist of the typical "tonic-clonic' phases. However, the occurrence of the electrographical seizure in the high K+ ACSF were not affected by amygdala-kindling operation. These results indicate that amygdala-kindling lowers the threshold for transsynaptic excitability and enhances the synchronized activity of the PRC induced by episodic proconvulsive manipulations such as tetanus stimulation.

Amygdala↗
PubMed1996

Intrinsic responses to Borna disease virus infection of the central nervous system.

Immune cells invading the central nervous system (CNS) in response to Borna disease virus (BDV) antigens are central to the pathogenesis of Borna disease (BD). We speculate that the response of the resident cells of the brain to infection may be involved in the sensitization and recruitment of these inflammatory cells. To separate the responses of resident cells from those of cells infiltrating from the periphery, we used dexamethasone to inhibit inflammatory reactions in BD. Treatment with dexamethasone prevented the development of clinical signs of BD, and the brains of treated animals showed no neuropathological lesions and a virtual absence of markers of inflammation, cell infiltration, or activation normally seen in the CNS of BDV-infected rats. In contrast, treatment with dexamethasone exacerbated the expression of BDV RNA, which was paralleled by a similarly elevated expression of mRNAs for egr-1, c-fos, and c-jun. Furthermore, dexamethasone failed to inhibit the increase in expression of mRNAs for tumor necrosis factor alpha, macrophage inflammatory protein 1 beta, interleukin 6, and mob-1, which occurs in the CNS of animals infected with BDV. Our findings suggest that these genes, encoding transcription factors, chemokines, and proinflammatory cytokines, might be directly activated in CNS resident cells by BDV. This result supports the hypothesis that the initial phase of the inflammatory response to BDV infection in the brain may be dependent upon virus-induced activation of CNS resident cells.

Animals↗