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Biomedical subjects

N Maehara

Publications and source records attributed to N Maehara.

At least 37 records · Page 2Linked to original sources
PubMed1999

Preparation and partial characterization of monoclonal antibodies against the protective protein antigen of Erysipelothrix rhusiopathiae.

Thirteen mouse monoclonal antibodies (Mabs) against the protective protein antigen (P64) of Erysipelothrix rhusiopathiae were prepared and partially characterized. The titres of the Mabs varied from 200 to 1,638,400 as determined by enzyme-linked immunosorbent assay (ELISA). Of the 13 Mabs 10, two and one belonged to the IgG2a, IgG1 and IgM subclasses, respectively. All Mabs reacted strongly with the 64 kDa protein and weakly with the 43 kDa protein upon Western blotting of the alkaline extract (AE) of E. rhusiopathiae. The protective activity (PD50/ml) of the 13 Mabs against E. rhusiopathiae infection in mice varied from < 50 to > 50,000. These Mabs were classified into three groups, highly protective Mabs, moderately protective Mabs and Mabs which did not possess protective activity, based on the protective index (ratio of the PD50/ml to the antibody titre). These results suggest that the 64 kDa protein is an effective protective antigen, which is easily cleaved into many small proteins, including the 43 kDa protein, and possesses at least two epitopes related to its protective activity and at least one epitope which is not related to protection of mice against E. rhusiopathiae infection.

Animals↗
PubMed1999

New exfoliative toxin produced by a plasmid-carrying strain of Staphylococcus hyicus.

A new serotype of Staphylococcus hyicus exfoliative toxin (SHET), serotype B, was isolated from the culture filtrate of a plasmid-carrying strain of S. hyicus. The new SHET was purified by precipitation with 70% saturated ammonium sulfate, gel filtration on a Sephadex G-75 column, column chromatography on DEAE-Cellulofine A-500, and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The new SHET caused exfoliation of the epidermis as determined by the so-called Nikolsky sign when inoculated into 1-day-old chickens. The new SHET was serologically different from Staphylococcus aureus exfoliative toxins (ETs) (ETA, ETB, and ETC) and from the SHET from the plasmidless strain but showed the same molecular weight as the other serotypes of toxins on SDS-PAGE. It was thermolabile and lost its toxicity after being heated at 60 degrees C for 30 min. We propose that the new SHET be designated SHETB and that the SHET produced by the plasmidless strain be designated SHETA.

Animals↗
PubMed1998

9-Hydroxyellipticine inhibits telomerase activity in human pancreatic cancer cells.

There is increasing interest in identifying potent inhibitors of telomerase because the enzyme plays a crucial role in the development of cellular immortality and carcinogenesis. We hypothesized that 9-hydroxyellipticine (9-HE), an antitumor alkaloid, would inhibit telomerase activity because the drug has a unique mechanism of inhibiting phosphorylation of mutant p53 protein via inhibition of protein kinases, thereby restoring wild-type p53 function. This study was conducted to examine the effect of 9-HE on telomerase activity in human pancreatic cancer cells with differing p53 gene status. 9-HE treatment at relatively high concentrations resulted in rapid, complete inhibition of telomerase activity, irrespective of the p53 status. We conclude that 9-HE may exert a strong inhibitory effect on telomerase activity possibly through inhibition of protein kinases rather than through restoration of functional wild-type p53.

Antimetabolites, Antineoplastic↗
PubMed1998

Use of the protective antigen of Erysipelothrix rhusiopathiae in the enzyme-linked immunosorbent assay and latex agglutination.

To establish a safe and convenient serodiagnostic method for swine erysipelas, a purified protective protein antigen of Erysipelothrix rhusiopathiae, which included a large amount of protective protein (64 kDa protein), was used for enzyme-linked immunosorbent assay (ELISA) and the latex agglutination (LA) test. In the ELISA, the antisera to four different serovars (1a, 2, 5 and 20) of E. rhusiopathiae exhibit a positive reaction, while antisera to other species of bacteria (Listeria monocytogenes, Staphylococcus aureus, Streptococcus suis, Rhodococcus equi and Corynebacterium pseudotuberculosis) exhibit a negative reaction. In the LA test, the antisera to three different serovars (1a, 2 and 5) of E. rhusiopathiae reacted with P64-sensitized latex beads, while the antiserum to serovar 20 (2553 strain) did not. Moreover, the antisera to other species of bacteria (Listeria monocytogenes, Staphylococcus aureus, Streptococcus suis, Rhodococcus equi and Corynebacterium pseudotuberculosis) did not in this test. Comparing the results of the growth agglutination (GA), ELISA and LA tests of 284 swine sera, there was a high degree of correlation among the results. The detection of anti-E. rhusiopathiae antibodies in the GA, ELISA and LA tests were compared using sera from pigs immunized with P64, alkaline extract (AE) and live-cell vaccine (LV). In all three tests, anti-E. rhusiopathiae antibodies could be detected 1 week after immunization. The serum antibody titre as determined by the LA test increased moderately, as did that by the GA test, while that determined by ELISA increased rapidly. These results suggested that ELISA could be used to monitor changes in anti-E. rhusiopathiae antibody titre and the LA test could be used in the screening test for swine erysipelas.

Animals↗
PubMed1998

[Significance of measuring urinary 17-ketosteroid sulfates at the work-place].

We examined availability of urinary 17-KS-S to evaluate work and job strain by presented the results in two field research and one experiment. It became clear that urinary S/OH was a comprehensive parameter of thermal strain, under the combined load condition of temperature and exercise, and as an additional factor, under the various load conditions of air velocity. Significant changes of urinary S/OH before and after the rest break and holiday suggested that the findings reflected fatigue conditions. This suggestion was strongly supported by the finding that the values of urinary S/OH on the first day-off after a mid-night shift and those 1 to 3 days later were not able to recover to the value before the night shift. A ratio between urinary 17-KS-S and 17-OHCS, S/OH, suggests a method of evaluating the degree of strain and the condition of fatigue and over-fatigue by measuring these parameters and thus clarifying the work conditions and work-place environment.

17-Hydroxycorticosteroids↗
PubMed1996

Correlation between occurrence of exudative epidermitis and exfoliative toxin-producing ability of Staphylococcus hyicus.

Staphylococcus hyicus was isolated from healthy pigs and pigs affected with exudative epidermitis (EE). Thirty seven strains (P-7 to P-43) were isolated from pigs affected with EE on 8 farms while 131 strains were isolated from healthy pigs bred on 2 farms in Japan. Isolation rate for pigs affected with EE was 100% while that for healthy pigs was 35.4%. The biochemical and cultural characteristics of the isolates from healthy and diseased pigs were identical except for the Voges-Proskauer reaction. The culture supernatant of many isolates caused skin exfoliation in 1-day-old chickens. Therefore, many isolates were considered to produce S. hyicus exfoliative toxin (shET). The rate of shET production by the isolates from piglets affected with EE was 87.5%, while that of the isolates from healthy pigs was 76.1%. shETs were divided in two serotypes by immunodiffusion. Piglets experimentally infected with shET-producing and nonproducing strains were observed. Local skin erythema at the inoculation site was observed with nonproducing strains and disappeared within 48 h, while the skin erythema at the sites inoculated with shET-producing strains did not disappear until 7 days after inoculation. Typical clinical signs, such as exfoliation, exudation and crusting were observed only in the piglets inoculated with shET-producing strains.

Animals↗
PubMed1996

Improvement of Tsukiji free fish market in Tokyo ("Kaizen" of work environment).

"TSUKIJI" is one of the biggest and most famous Free Fish Markets in the world, but there are many problems on the working condition because it was built about 60 years ago. Our investigation was held 1991 to 1993 to give some improvements regarding layout of buildings, working time, heat condition at refrigerator, working posture, and so on. We used a questionnaire on daily life and health care of workers, time study with measurement of heartbeats, and checklist (using Checklist for Improvement of Safety-Health and Working Conditions,' made by ILO). The main occupations in TSUKIJI were seller, buyer, delivery worker, and refrigerator maintenance worker. Their starting time was early in the morning, usually between 2:00 a.m. and 5:00 a.m., but the hardest one was delivery workers starting at 9:00 p.m. They used auto cargo car for carrying to shops from refrigerator or from auction places many times. Sellers had two different types of work. First, the seller set up the auction, numbering the fish (or cases of seafood), arranging them in order, and so on. The rest of the work was transaction of invoices, sometimes using VDU with almost sitting. These works did not look well balanced. Buyer of tuna cut if like lumber by electric saws did not have guard for protection and there were more than 200 machines. Overlooking the market by checklist, some problems were clarified, and suggestions for improvement include restructuring the whole layout of the market or reforming buildings, standardization of the cases, adjustment of health facilities, safety protection on tools and machines, management of working system, working posture, health care, and so on.

Adult↗
PubMed1995

Malignant lymphoma of the thyroid with evidence of an Epstein-Barr viral infection concomitant with thalassemia minor: report of a case.

We report herein the unusual case of a 53-year-old Japanese man in whom malignant lymphoma of the thyroid was found to coexist with asymptomatic thalassemia minor and an elevated titer (1:80) of immunoglobulin G against the Epstein-Barr viral capsid antigen. A total thyroidectomy with lymphadenectomy was performed, and the thyroid was found to be almost replaced by the neoplasm, the microscopy of which revealed malignant lymphoma of the diffuse, large-cell type. The existence of this case led us to question whether malignant lymphoma of the thyroid and an elevated titer for the Epstein-Barr virus might have a possible mutual association.

Antigens, Viral↗
PubMed1995

Optimum culture conditions for production of exfoliative toxin by Staphylococcus hyicus.

Optimum culture conditions for the production of exfoliative toxin by Staphylococcus hyicus (shET) were examined. High shET activity was obtained from the culture filtrate of HI and TY broth inoculated with S. hyicus. The pH in these two media ranged from 7 to 8.5 during bacterial culture, while the lowest pH in TS and BHI broth was less than 6. shET activity in the culture filtrate from TY broth inoculated with 10(7) CFU of S. hyicus per ml was higher than that in TY broth inoculated with 10(6) and 10(8) CFU of bacteria per ml. When shET activity in the culture filtrate was measured under various shaking conditions, the culture filtrate shaken at 75 oscillations per min had the highest shET activity of the five shaking conditions. shET activity of the culture filtrate of TY broth to which protease inhibitor had been added was the same as that of TY broth without inhibitor. shET activity in a shaking culture in an Erlenmeyer flask was also the same as that in sac culture and that in shaking culture using a shaking (Sakaguchi) flask. shET activity in TY broth supplemented with 100 mM glucose was significantly lower than that in TY broth without glucose. Based on the above results, the optimum culture conditions for the production of shET were as follows: inoculation of 3 x 10(9) CFU of S. hyicus strain P-1 into 300 ml of TY broth in a 2,000-ml Erlenmeyer flask, and incubation at 37 C with shaking at 75 oscillations per min.(ABSTRACT TRUNCATED AT 250 WORDS)

Ammonium Sulfate↗
PubMed1995

Possible receptor for exfoliative toxins produced by Staphylococcus hyicus and Staphylococcus aureus.

Exfoliative toxin produced by Staphylococcus hyicus bound to the GM4-like glycolipid extracted from the skin of 1-day-old chickens but did not bind to glycolipid from adult chickens or suckling mice. Exfoliative toxin produced by Staphylococcus aureus bound to the GM4-like glycolipid extracted from the skin of suckling mice but not to glycolipid from 1-day-old or adult chickens. S. hyicus and S. aureus exfoliative toxins lost their toxicity by preincubation with GM4-like glycolipid from 1-day-old chickens and suckling mice, respectively.

Animals↗
PubMed1993

Detection of alpha-interferon in nasopharyngeal secretions and sera in children infected with respiratory syncytial virus.

We investigated the relationship between respiratory syncytial virus (RSV) antigen and interferon (IFN) in nasopharyngeal secretions (NPS) and sera obtained from 252 patients infected with RSV. A total of 146 (57.9%) of 252 patients had IFN in NPS with a mean titer of 28 units/ml and IFN was detected in 164 (71.6%) of 229 patients in the acute stage sera with a mean titer of 28 units/ml. IFN activities were neutralized with antiserum to IFN-alpha. RSV antigen in NPS decreased on Day 5 and later in parallel with the change of mean titer of IFN in NPS. IFN in NPS was detected in 40 to 60% of the samples with some fluctuation in the acute stage. Within 4 days IFN was detected in more than 70% of the sera whereas on Day 5 and later the IFN positivity rate decreased in sera. RSV antigen in NPS decreased in the older patient groups. No significant change of positive rate of IFN in NPS was observed in different age groups and the mean titer of IFN in NPS and sera did not vary with age, except in those younger than 3 months and older than 3 years of age.

Age Factors↗
PubMed1992

Interferon production during the course of Mycoplasma pneumoniae infection.

In patients infected with Mycoplasma pneumoniae the development of interferon (IFN) was studied in nasopharyngeal secretions and sera. The production of IFN-gamma by lymphocytes was also investigated in response to M. pneumoniae antigen and mumps virus antigen. IFN-alpha was detected in 25 (61.0%) of 41 nasopharyngeal secretion samples and in 25 (59.5%) of 42 serum samples within 6 days after the onset of illness. IFN-alpha was significantly higher in nasopharyngeal secretions than in sera and a significant correlation was observed between the two. In most of the patients lymphocytes produced a larger amount of IFN-gamma in the convalescent stage than in the acute stage, when lymphocytes were stimulated with M. pneumoniae antigen. In some patients, however, lymphocytes did not produce IFN-gamma during the course of illness. Such lymphocytes, negative for IFN-gamma production in response to M. pneumoniae, produced IFN-gamma after the depletion of macrophages, and readdition of macrophages suppressed the production of IFN-gamma by lymphocytes. When lymphocytes were stimulated with heterogeneous antigen (mumps virus), they produced no IFN or a small amount of IFN in the acute stage of M. pneumoniae infection, and IFN production increased in the convalescent stage. Different mechanisms seem to work for homogeneous and heterogeneous antigens in the suppression of IFN production in M. pneumoniae infection.

Adolescent↗
PubMed1990

Production of circulation interferon in children with varicella.

Interferon (IFN) alpha was detected in the serum of children with varicella. The serum IFN was demonstrated in the acute phase of varicella and became negative 7 days after the onset of rash. Serum IFN was detected during the incubation period in two patients tested before the onset of rash. Some correlation was shown between the positive rate of circulating IFN and the severity of illness.

Acute Disease↗
PubMed1990

Evaluation of live trivalent vaccine of measles AIK-C strain, mumps Hoshino strain and rubella Takahashi strain, by virus-specific interferon-gamma production and antibody response.

A trivalent measles-mumps-rubella live virus vaccine, containing measles AIK-C strain, mumps Hoshino strain, and rubella Takahashi strain, was evaluated in 229 children, aged 1 to 5 years. The vaccine induced a high seroconversion rate: 221 (98.7%) out of 224 subjects initially seronegative for measles virus, 167 (93.3%) out of 179 initially seronegative for mumps virus, and 212 (99.1%) out of 214 initially seronegative for rubella virus. It also induced a sufficient cellular immunity against each of the three viruses in over 90% of the subjects, as judged by virus-specific interferon-gamma (IFN-gamma) production. Virus-specific IFN-gamma production was observed 10 days after vaccination by stimulation with measles virus and rubella virus and 14 days after vaccination by stimulation with mumps virus. Mumps-virus-specific IFN-gamma production was observed in 7 out of 12 recipients without seroconversion for mumps virus. And measles-virus-specific IFN-gamma production was demonstrated in one out of three recipients without seroconversion for measles virus. A significant correlation was observed between the serum antibody and IFN-gamma production six weeks after vaccination for measles virus (r = 0.201, P less than 0.01) and for mumps virus (r = 0.174, P less than 0.05) but not for rubella virus (r = -0.045, P less than 0.05). The incidence of febrile reactions of greater than or equal to 37.5 C was quite low, 14.4%, and that of greater than or equal to 39 C occurred in only 1.3% of the recipients. These results suggested that the trivalent vaccine induced sufficient humoral and cellular immunity and yet resulted in no more untoward reaction than observed from the measles vaccine alone.

Antibodies, Viral↗
PubMed1990

[A case of Pneumocystis carinii pneumonia with hyperinfection of Strongyloides stercoralis complicated with smoldering adult T-cell leukemia].

A 43-year-old woman visited a clinic for an attack of bronchial asthma which she had been suffering since her childhood. She was treated with prednisolone which was used for the first time. Two weeks later, she had a fever and her chest X-ray showed diffuse reticulonodular shadows on both middle to lower lung fields. In spite of the use of antibacterial drugs, her symptoms such as cough, dyspnea, malaise and fever increased. It was revealed that she had Stronglyoides sterocoralis in the stool. She was referred to our department for treatment and further examination. Transbronchial lung biopsy (TBLB) was performed, and cyst of Pneumocystis carinii were histologically detected in the lung specimen. Anti-human T-lymphotropic virus type 1 (HTLV-1) antibody in the serum was 1:4,096 less than. Typical adult T-cell leukemia (ATL) cells were also observed in the peripheral blood smear at the rate of 10-15% of leukocytes. The parasite was observed in the sputum too. We diagnosed her as having Pneumocystis carinii pneumonia with hyperinfection of Strongyloides stercoralis complicated with smoldering ATL, and the pneumonia might have been induced by steroid therapy (total doses of 500 mg, for 25 days). After sulfamethoxazole-trimethoprim (ST compound) was used for the Pneumocystis carinii pneumonia, her symptoms markedly subsided, and the chest X-ray findings turned to normal by 45 days after the treatment. Thiabendazole was initially administered for the Strongyloidiasis and the parasite temporarily disappeared from both sputum and stool. Then pyrvinium pamoate and mebendazole were used, but the parasite could not be completely eradicated in the stool. We did not treat the smoldering ATL because there were no symptoms. We have been looking after her as an outpatient now, and she has neither symptoms nor signs.

Adult↗
PubMed1989

Significance of cardiovascular malformations in cystic hygroma: a new interpretation of the pathogenesis.

Fetuses with cystic hygroma or loose skin of the neck were studied chromosomally and phenotypically to clarify the relation between neck abnormality and cardiovascular malformations. Of 12 fetuses, 9 had chromosome abnormalities: 4 with 45,X, 3 with trisomy 21, one each with trisomy 13, dup 6q. One had normal chromosomes. Two cases, in which chromosome analysis was unsuccessful, were morphologically suspected to be trisomy 13. Nine of the 12 fetuses had either bilateral cystic hygroma of the neck (7 cases) or nuchal bleb (2 cases: trisomy 13 and dup 6q). Two of the 3 remaining cases (trisomy 21) had loose skin of the neck, and one had edematous swelling of the skin of the neck. Except for the last case of trisomy 21, 11 fetuses (91.7%) had severe and/or rare cardiovascular malformations. They were divided into 3 major groups: a) spectrum of hypoplastic left heart syndrome (45,X and dup 6q), b) double outlet right ventricle, agenesis of semilunar valve (trisomy 13), and c) abnormality of atrioventricular orifice or valves (trisomy 21). One fetus with normal chromosomes had persistent left superior vena cava instead of absent right one and calcification of myocardium. Histological observation of edematous skin demonstrated the abnormal distribution of lymph vessels, including their absence. Some cases showed hypoplastic thymus. To integrate the findings of the present study and the descriptions in the literature, a pathogenesis is hypothesized in relation to migration of neural crest cells and extracellular matrix.

Abnormalities, Multiple↗
PubMed1989

Polypoid squamous cell carcinoma of the larynx. An immunohistochemical study for ras p21 and cytokeratin.

Polypoid squamous cell carcinoma of the larynx consists of two components, namely, squamous cell carcinoma and sarcomatoid spindle cells. To further investigate the histogenesis of the spindle cell component, we studied two cases of polypoid squamous cell carcinoma of the larynx by immunohistochemistry and ultrastructural analysis. Positive staining for ras oncogene p21 and cytokeratin was demonstrated in both squamous cell carcinoma and spindle cell component. Only the latter component was positive for vimentin. Electron microscopic examination showed well-developed desmosomes in spindle cells. These results suggest that the spindle cell component is epithelial in origin and malignantly neoplastic; it originates from mesenchymal metaplasia or squamous cell carcinoma.

Aged↗