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Biomedical subjects

N Nagase

Publications and source records attributed to N Nagase.

17 recordsLinked to original sources
PubMed2001

Antimicrobial susceptibility of Staphylococcus intermedius isolated from healthy and diseased dogs.

A total of 90 strains of Staphylococcus intermedius isolated from dogs were examined for antimicrobial susceptibility. There were no significant differences in the distribution patterns of MICs between strains from 1982 to 1985 and those from 1999, and between strains from healthy dogs and those from diseased dogs. All of the strains were susceptible to ABPC, DMPPC, CEX, TDM, ERFX, BFLX, and FF at concentrations of 0.05 to 6.25 microg/ml. The MICs of OTC, KM, EM, AIV-TS, and LCM were distributed in a broad range of 0.1 to >100 microg/ml, indicating the existence of resistant as well as susceptible populations of S. intermedius. Thirty-three strains (36.7%) were resistant to one or more anitmicrobial agents such as OTC (n=32), KM (n=9), EM (n=7), AIV-TS (n=7), and LCM (n=7).

Animals↗
PubMed2000

Characterization of Staphylococcus aureus coagulase type VII isolates from staphylococcal food poisoning outbreaks (1980-1995) in Tokyo, Japan, by pulsed-field gel electrophoresis.

Staphylococcus aureus coagulase type VII strains have been the strains most frequently isolated from staphylococcal food poisoning outbreaks in Tokyo, Japan. We applied pulsed-field gel electrophoresis (PFGE) of chromosomal DNA digested with SmaI to characterize 129 coagulase type VII strains. These were isolated from 129 cases occurring in outbreaks in 35 districts during a 16-year period (1980-1995). The 129 outbreak strains were classified into three types, designated A (n = 115), B (n = 10), and C (n = 4). Types A and C were further divided into 33 (A1 to A33) and 4 (C1 to C4) subtypes, respectively. Strains of the same subtypes were isolated from food poisoning cases in the same districts at time intervals of 1 or 2 to 5 years. PFGE typing appears to be a useful method for subdividing strains of S. aureus coagulase type VII. A combination of coagulase typing and PFGE typing would provide more detailed information than the former method alone in epidemiologic investigations of staphylococcal food poisoning.

Bacterial Typing Techniques↗
PubMed1996

Hypertension and serum Mg in the patients with diabetes and coronary heart disease.

Interrelations between hypertension (HT), ischemic heart disease (IHD) and diabetes mellitus (DM) were investigated in the diabetic subjects without IHD (DM group) or with IHD (DM + IHD group) and subjects with IHD (IHD group) which were not complicated with DM. 1. The incidence of hypertension of DM group, DM+IHD group and IHD group is 40, 54, 38% respectively. 2. The incidence of hyperlipidemia of DM group, DM + IHD group and IHD group is 55, 71, 56% respectively. 3. Serum Mg levels of DM (1.9 +/- 0.37 mg/dl), DM + IHD (1.8 +/- 0.23) and IHD (1.9 +/- 0.33) were significantly lower than that of normal control (2.3 +/- 0.32). 4. Serum Mg level of poorly controlled diabetic patients is lower than that of well controlled diabetic patients. These results suggested that Magnesium deficient state is one of the cause of insulin resistancy.

Adult↗
PubMed1989

Distribution and metabolism of norepinephrine, cyclic AMP and cyclic GMP in the atrioventricular conducting tissue of the bovine heart.

The distribution of norepinephrine (NE), cyclic AMP (cAMP) and cyclic GMP (cGMP) and the activities of related enzymes in the atrioventricular (A-V) conducting tissue of the bovine heart were examined. The concentration of NE in the atrium was about twice that in the ventricle. In the A-V conducting tissue, the concentration of NE was highest in the atrioventricular node (AVN) and lowest in the false tendon (FT), with intermediate levels in the bundle of His (HIS) and the right and left bundle branches (RLBB). The activity of monoamine oxidase (MAO) in the atrium was about 2.2 times that in the ventricle. In the A-V conducting tissue, the activity of MAO was highest in the HIS and lowest in the FT. The activity of catechol-o-methyltransferase (COMT) in the atrium and ventricle was similar, and that in the HIS was slightly, but not significantly, higher than that in other regions of the A-V conducting tissue. The concentration of cAMP in the ventricle was about twice that in the atrium. In the A-V conducting tissue, the concentration of cAMP was higher in the AVN and FT than in the HIS and RLBB. The distribution of adenylate cyclase (AC) was similar to that of NE. The phosphodiesterase (PDE) activity in the atrium and ventricle was similar. No significant difference was found in the level of PDE activity in different regions of the A-V conducting tissue. The concentration of cGMP was slightly, but not significantly, higher in the A-V conducting tissue than in the atrium or ventricle. In the A-V conducting tissue, the concentration of cGMP was highest in the FT and the concentrations in the HIS, RLBB and AVN were similar. These findings suggest that in the A-V conduction tissue, the regions that have the higher spontaneous pacemaker rates have higher NE content and AC activity, that is sensitivity to NE. Furthermore, the sensitivity for muscarinic cholinergic stimulation is higher in the conducting tissue (especially in the FT) than in the atrium and ventricle.

Adenylyl Cyclases↗
PubMed1989

Inhibitory factor of actomyosin ATPase in the cardiac conduction system.

ATPase activation and superprecipitation of natural actomyosin in the cardiac conduction system (specialized myocardium) and ventricle were compared. The ATPase activity and superprecipitation of natural actomyosin from the specialized myocardium were much lower than those from the ventricle. The sensitivity of natural actomyosin ATPase to calcium was higher in the specialized myocardium than in the ventricle, whereas the maximum activity of the specialized myocardium was lower than that of the ventricle. The Ca2+-desensitized actomyosin of the specialized myocardium presented scarcely any superprecipitation. Addition of the 0-40% ammonium sulfate fraction (mainly containing myosin and actin) of natural actomyosin from the specialized myocardium to ventricular natural actomyosin inhibited superprecipitation of the latter. On the other hand, addition of the 40-60% ammonium sulfate fraction (mainly containing troponins and tropomyosin) of natural actomyosin from the specialized myocardium enhanced superprecipitation of ventricular natural actomyosin. These results suggested that the specialized myocardium contains some factor(s) that inhibits actin-myosin interaction.

Actomyosin↗
PubMed1989

Myocardial disorders caused by magnesium deficiency in diabetic KK mice.

Studies were made on the diabetic state and the pathogenesis of myocardial disorders in KK mice with the following results: (1) KK mice showed glucose intolerance, hyperinsulinemia and hyperlipidemia; (2) their electrocardiograms (ECGs) showed a marked left-axis deviation of the QRS vector; (3) they showed epicardial calcification and myocardial disorders; (4) the Ca content of their myocardiums was much higher, and the Mg contents in the erythrocytes and myocardiums were much lower than those of control mice; (5) the addition of Mg to the drinking water of KK mice normalized these changes, and suppressed their myocardial disorders, but did not normalize their ECG changes. These results suggested that Mg deficiency plays an important role in the development of myocardial disorders in KK mice.

Animals↗
PubMed1989

[Clinical experiences with intraluminal irradiation using 198Au grains in the treatment of bile duct carcinoma].

Three cases of a bile duct carcinoma were treatment with radiotherapy, using intracatheterized 198Au grains. The intracatheter 198Au grains, placed in an inner tube, were inserted into a percutaneous transhepatic catheter. The number of 198Au grains used depended upon the length of the tumor. Tips of plastic were placed between the grains to improve the spatial and temporal dose allocation. The number of grains used can be changed quite easily, according to the length of the tumor, and the period of insertion in our cases was shorter than for a 192Ir wire. These three patients also received external irradiation and, since completion of treatment, two have continued to do well for the past 5 months. There have been no systemic or local complication.

Aged↗
PubMed1987

[Effectiveness of radiation therapy in metastatic bone tumors].

The effectiveness of radiation therapy for metastatic bone tumor in 61 patients with 80 lesions has been evaluated. Relief from pain resulted in 87% all the treated lesions and this continued for more than two years in eight lesions of seven patients. There was no statistical difference in the pain relief achieved among the sites and the histologies of the primary tumors, and also no difference was noted as to the treated regions. Pain relief from the lesions of a squamous cell carcinoma tended to begin with smaller doses when compared with that of an adenocarcinoma. Our results suggest that radiation therapy in general appears to be an effective technique in achieving long term control of pain, but for some patients those with a generalized metastases or an uncontrolled primary tumor, for example, this tedious treatment has limited value and so should be withheld.

Adenocarcinoma↗
PubMed1986

Distribution of light chains and ATPase activity of myosin in the atrioventricular conducting tissue of bovine heart.

The relations of the light chains of myosins of the atria, ventricles, and atrioventricular conducting tissue (specialized myocardial tissue) and the distribution of the light chains of myosin in different regions of the atrioventricular conducting tissue in bovine heart were examined. Two-dimensional gel electrophoresis showed that the atrial and ventricular myosins each had two light chains (LC1 and LC2). Ventricular LC1 differed from atrial LC1, but ventricular LC2 corresponded to atrial LC2. The specialized myocardial tissue myosin had three light chains (named here SL1, SL2, and SL3). SL1 comigrated with ventricular LC1, SL2 with atrial LC1, and SL3 with ventricular LC2 and atrial LC2. The compositions of the three light chains of myosins in various regions of the atrioventricular conducting tissue were determined by sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis. The percentage proportion of SL1 decreased in the order--atrioventricular node (AVN), right and left bundle branches (RLBB), His bundle (HIS), false tendon (FT) myosin; while the percentage proportion of SL2 decreased in the order--FT and HIS, RLBB, AVN myosin. The percentages of SL3 in these four regions were similar. The Ca2+-activated ATPase activity of myosin was highest in the AVN and lowest in the FT. The activities in the HIS and RLBB were intermediate between those in the AVN and FT. Thus, the composition of the light chains and the Ca2+-activated ATPase activity were different in various regions of the atrioventricular conducting tissue.

Adenosine Triphosphatases↗
PubMed1983

Intact and subcellular form of thymocytes of rats are exceptionally immunogenic in mice for inducing anti-Thy-1 T cell-independent class 2 antibody responses.

Results of the present study show that the primary anti-Thy-1.1 antibody response to rat antigen in Thy-1.2 mice is induced exclusively by thymocyte antigen. Thy-1 antigens of brain and bone marrow, which expressed much Thy-1 antigen, were poorly immunogenic if at all. Brain Thy-1 antigen considerably inhibited the immunogenicity of thymocyte Thy-1. Moreover, we found that subcellular form of thymocytes induce as high antibody responses as intact thymocytes do. The subcellular thymocyte Thy-1 antigen behaved as TI-2 antigen, inducing a good response in athymic nude mice but not in CBA/N mice with a B cell defect. The significance of these findings is discussed in relation to the possible physiological activity of Thy-1 or Thy-1-linked molecules on thymocytes specifically mediating lymphocyte differentiation.

Animals↗
PubMed1983

Cinemicrographic study of cell proliferation pattern and interdivision times of human keratinocytes in primary culture.

The stratified squamous epithelium of the skin, the epidermis, is a renewing cell population. In order for epidermis to remain the same size, each dividing basal cell must produce on an average, one daughter cell that will remain as a germinative cell and another that will perform terminal differentiation (differential mitosis). In order to investigate cell kinetics in the epidermis, the information obtained from in vivo study is limited, and offers only indirect evidence for the determination of cell cycle time and cell proliferation pattern. Keratinocytes in cell culture are unique in formation of a multilayered cellular sheet in which the keratinocytes form a structure resembling the epidermis in vivo, and keratinize at the top. In the early days of the primary culture of human keratinocytes, when the cells proliferate to form a monolayer sheet, direct access to cell proliferation pattern and measurement of interdivision time can be done using techniques of time-lapse cinemicrography. The primary cultures at 8-20 days of incubation were employed for cinemicrographic observation when small polygonal cells appeared in groups, when numerous mitotic figures were observed, and when stratification of the cells had not yet occurred. The appropriate field was marked and followed for up to 6 days. Photographic prints were made from the 16 mm cine film, and dendrograms were made and analyzed for pattern of cell proliferation and interdivision time. Most cells in the field divided two or three times during the period of observation. Sister-sister pairs of the second and third generations divided after approximately the same interdivision times. However, some cells have never divided. Some of the sister-sister pairs differed considerably in their interdivision times. In some cultures synchronous division was quite evident. The average interdivision time was about 26 hr in the majority of cultures, and it is suggested that the estimated long cell cycle time in vivo might be overestimated due to the existence of non-cycling cells in the germinative population.

Cell Division↗
PubMed1982

Metabolism of an aromatic retinoid Ro 10-9359 by cultured human epidermal keratinocytes.

An aromatic retinoid Ro 10-9359 is metabolized after absorption from intestine to form Ro 10-1670 which is an active therapeutic compound. The epidermal keratinocytes, a main target tissue of retinoid therapy in dermatology, was examined in the capacity to metabolize the retinoid. The culture of human epidermal keratinocytes was treated with 10(-6) M Ro 10-9359 and the metabolites released in the medium was analyzed by HPLC. The HPLC profile showed a distinct peak of Ro 10-1670. The human skin fibroblasts, HeLa cells. Chang liver cells and 3T3 cells were less active in metabolizing Ro 10-9359, and only a small amount of Ro 10-1670 was detected in the culture of human skin fibroblasts treated with 10(-6) M Ro 10-9359 for 2 days. When these cells were disrupted by a glass homogenizer, and incubated with Ro 10-9359, no Ro 10-1670 formation was detected.

Acitretin↗
PubMed1982

Alterations in the immunogenic properties of sheep erythrocytes by sonic disruption.

A solubilized sheep red blood cell (SRBC) antigen (supernatant fraction obtained by centrifuging 10(7)-2 x 108 sonicated SRBC at 6 x 10(4) g for 30 min [Sup-SRBC]), whose ability to inhibit anti-SRBC plaque formation was 70% of that of the original sonicated SRBC, was unable to elicit a detectable antibody response in either unprimed or SRBC-primed mice. However, Sup-SRBC as well as intact SRBC antigens generated memory for the secondary response, which was transferable to irradiated syngeneic recipients by injection of immune spleen cells. The memory generated by Sup-SRBC involved helper memory for anti-trinitrophenyl group (TNP) response to challenge with TNP-conjugated SRBC. Increase in the helper T cell memory in the spleens of Sup-SRBC-primed mice was also demonstrated by an in vitro culture experiment and by an adoptive cell transfer experiment. In contrast, no detectable B cell memory was generated by Sup-SRBC. Repeated stimulation with Sup-SRBC never induced significant antibody response but reduced the level of memory. A single injection of a low dose (10(6)) of SRBC also failed to induce a definite primary antibody response generating memory for the secondary response. However, repeated stimulation with this dose of SRBC induced a high antibody response and generated good memory. From these results it is suggested that the intact structure of SRBC is required for the activation of B cells, but is not necessary for the stimulation of T cells.

Animals↗