Biomedical subjects

M Torii

Publications and source records attributed to M Torii.

At least 73 records · Page 4Linked to original sources

PubMed1994

[Strongyloidiasis associated with multiple myeloma in Ehime prefecture].

A 76-year-old male with multiple myeloma, who was born and had lived in Ehime Prefecture was admitted to our hospital because of high fever. The chest X-p film showed right middle lobal pneumonia. Eosinophilia was detected and a stool smear examination revealed rhabditis form larvae of the nematode. The filaria form larvae of Strongyloides stercoralis were detected by stool culture. Antibiotics and pyruvinium pamoate were administered to bacterial pneumonia and hyperinfection of the strongyloides, respectively. Consequently, pneumonia and strongyloidiasis were promptly improved. It was considered that he was infected with strongyloides in south-east Asia during World-War II and a little autoinfection of this nematode had continued about 50 years. In addition, it was suggested that hyperinfection of strongyloides resulted from the immunosuppressive state induced by the chemotherapy for multiple myeloma.

Aged↗

PubMed1994

Incorporation of bacterial inhibitor into resin composite.

Attempts to produce resin composite with antibacterial properties by incorporation of an antibacterial agent such as chlorhexidine have been reported, but problems can arise due to release of the inhibitory agent from the composite. Such problems may include toxic effects, influence on mechanical properties, and loss of effectiveness. A new monomer, methacryloyloxydodecylpyridinium bromide (MDPB), was synthesized by combining an antibacterial agent and methacryloyl group. The monomer was incorporated into resin composite to develop a non-releasing antibacterial composite. The ability of composite incorporating MDPB to inhibit growth and plaque accumulation by Streptococcus mutans in vitro was assayed, elution of antibacterial components from the material was investigated, and the influence of incorporation of MDPB on the mechanical properties of composite was studied. Uncured MDPB revealed antibacterial activity against S. mutans and six other species of oral streptococci, with the minimum inhibitory concentration for S. mutans being comparable with that of triclosan. After composite incorporating MDPB was cured, no elution of the antibacterial components was observed from the material, even after 90 days' immersion in water or other solvents. Growth of S. mutans on agar under specimens of MDPB-containing composite was inhibited compared with controls. In a bacterial accumulation study, S. mutans accumulated to a lesser degree on the surface of composite incorporating MDPB (p < 0.05) than on control. Incorporation of MDPB had no significant influence on the mechanical properties of the composite.

Analysis of Variance↗

PubMed1994

Shear bond strength of amalgam adhesives to dentin.

This study compared the bond strength of resinous adhesives used to bond amalgam to dentin. The adhesives were: All-Bond 2 (AB), Liner-F (LF), SuperBond C&B (SB), Amalgambond (AM), Photo Bond (PB), and Panavia (PA). Occlusal surfaces of non-carious molars were ground wet to 600 grit finish, exposing dentin. The dentin surfaces were conditioned and the adhesives were applied according to manufacturers' instructions. Dispersalloy amalgam (D) was condensed onto the adhesive immediately. For comparison, resin composite, Photo Posterior (PO) and Bis-Fil (BIS) were used. After 24 hours of storage in 100% humidity at room temperature, shear bond strengths were determined with a shear testing jig in an Instron testing machine at a crosshead speed of 0.5 mm/minute. The data were compared using ANOVA, P < 0.01. AB, LF, D had significantly higher bond strengths than other amalgam adhesives. There was no significant difference between SB, D and PB, PO. Bond strength of PB, PA, D was significantly higher than PA, D. Thus, there were significant differences among adhesives for bonding amalgams. Amalgam to dentin and composite to dentin bond strength were comparable except for the All-Bond groups. Fracture patterns at the dentin/restoration interfaces were examined by scanning electron microscopy (SEM).

Analysis of Variance↗

PubMed1993

The metabolism of arachidonic acid to prostaglandin E2 in plerocercoids of Spirometra erinacei.

With a simplified method of extracting and purifying prostaglandins, trace prostaglandins (nanogram order) were detected by gas chromatography-mass spectrometry. Arachidonic acid was metabolized to prostaglandin E2 (PGE2) by plerocercoids of Spirometra erinacei, the PGE2 was detected in the medium after incubation with arachidonic acid, and the role of albumin in the absorption of free arachidonic acid by plerocercoids and in the release of its metabolite was investigated. Plerocercoids absorbed arachidonic acid-binding albumin and released PGE2 efficiently. PGE2 is known to suppress the functions of mononuclear cells of the host. The selective release of PGE2 may be related to the escape mechanism of plerocercoids of S. erinacei from the host immune system to become established larva migrans, i.e., sparganosis.

Absorption↗

PubMed1993

Effects of selected surfactants on purified glucosyltransferases from mutans streptococci and cellular adherence to smooth surfaces.

The inhibitory effect of non-ionic, anionic, cationic and ampholytic surfactants on cellular growth of Streptococcus mutans MT8148 and S. sobrinus 6715, on glucan synthesis by the purified glucosyltransferase (GTase) from these organisms, and on bacterial adherence to glass surfaces was examined in vitro. Cationic surfactants exhibited marked bactericidal activities. Anionic and ampholytic compounds were less strongly bactericidal and non-ionic surfactants produced only slight inhibition of cell growth under the conditions tested. Some non-ionic compounds had no effect on this. Glucan synthesis by GTase from mutans streptococci was inhibited by anionic and cationic surfactants. Among various GTase proteins, insoluble glucan synthesising GTases, i.e., S. mutans CA-GTase and S. sobrinus GTase-I were those most effectively inhibited by these agents. However, it was noted that whereas lower concentrations of cationic surfactants enhanced these GTase activities, higher concentrations of the surfactants were inhibitory. Non-ionic detergents stimulated soluble glucan synthesis from S. mutans CF-GTase and cationic and ampholytic surfactants enhanced or inhibited glucan synthesis depending on the concentrations of the surfactants. Sucrose-dependent cellular adherence of resting cells of mutans streptococci to glass surfaces was inhibited by the addition of surfactants that annulled the GTase activities.

Bacterial Adhesion↗

PubMed1993

Disappearance of seasonal variation of sweating responses in exercising man: effect of pre-heating in cold season.

The present study was designed to investigate the seasonal variation in thermal responses during moderate exercise. In winter, exercise was done after pre-heating for 30 min at an ambient temperature of 30 degrees C. Adult healthy men repeated the exercise at 40% of maximal oxygen uptake by a bicycle ergometer in a climatic chamber of an ambient temperature of 30 degrees C (relative humidity, 45%) in winter, spring, summer, and fall. In summer, the sweat rate increased immediately after the exercise started, whereas in winter it took in several minutes. The average sweat rate during exercise was significantly different (p < 0.01) in winter and compared to the other seasons. Significantly (p < 0.01) negative correlations were found between sweat rate and the rate of change of the mean skin temperature in each season. The regression equation was significantly (p < 0.01) different between winter and summer. After the pre-heating in winter, the sweating responses during exercise were similar to the responses in the summer. Thus, by thermal stimuli, the heat dissipation, especially skin evaporation due to sweating, may be stimulated in the cold season. It is suggested that sweating may be facilitated by not only the heat dissipation capacity of the hypothalamic mechanism with the thermal information via skin thermoreceptors but also by a change of peripheral sweat gland activity. Furthermore, the fall in skin temperature during the initial exercise may not be due to increased evaporative cooling, but to the vasoconstriction probably caused by non-thermal factors.

Acclimatization↗

PubMed1993

A comparative study on lipid peroxidation in cerebral cortex of stroke-prone spontaneously hypertensive and normotensive rats.

1. Lipid peroxidation and membrane-related enzyme changes in the cerebral cortex of stroke-prone rats (SHRSP) and normotensive rats were examined at 5 and 20 weeks of age. 2. In vivo formation of thiobarbituric acid-reactant substances was higher in SHRSP at 20 weeks of age and in vitro generation of free malondialdehyde was greater in SHRSP brains, both at 5 and 20 weeks of age, as compared with those in WKY. 3. Membrane-associated enzymes such as Na/K-ATPase and 5'-nucleotidase activities were lower in 20-week-old SHRSP than in age-matched WKY. 4. These results indicate how very prone the SHRSP brain is toward lipid peroxidation and subsequent membrane-related enzyme changes.

Animals↗

PubMed1993

Pharmacological studies on a new dihydrothienopyridine calcium antagonist. 4th communication: prophylactic and therapeutic effects of S-(+)-methyl-4,7-dihydro-3-isobutyl-6-methyl-4-(3-nitrophenyl)thieno[2, 3- b]pyridine-5-carboxylate in stroke-prone spontaneously hypertensive rats.

The prophylactic and therapeutic effects of S-312-d (S-(+)-methyl-4,7-dihydro-3-isobutyl-6-methyl-4-(3-nitrophenyl)thieno[2, 3- b]pyridine-5-carboxylate, CAS 120056-57-7) were compared with those of nimodipine or nicardipine using male stroke-prone spontaneously hypertensive rats (SHRSP). The survival rate of SHRSP was dose-dependently increased by once a day oral administration of S-312-d (0.3, 1, and 3 mg/kg) or nimodipine (10 mg/kg), while all non-treated SHRSP fed with high Na+ diet died within 40 days after the start of the experiment. All SHRSP treated with 3 mg/kg S-312-d survived during the 60-day experiment periods. Marked decreases of body weights and various neurological symptoms were also inhibited with S-312-d or nimodipine. Moderate diuretic effects were observed with S-312-d at doses of 1 and 3 mg/kg. The appearance of urinary occult blood in control SHRSP was markedly inhibited with S-312-d at 1 mg/kg and nimodipine at 10 mg/kg. Histological examination of the brain of SHRSP showed that cerebral stroke lesion including edema, hemorrhage, and/or softening was dose-dependently inhibited with S-312-d. Once a day oral administration of S-312-d (1, 3, or 10 mg/kg) dose-dependently increased the body weights and improved the neurological symptoms of diseased SHRSP. The appearance of proteinuria and of occult blood in the urine of SHRSP were also markedly inhibited with S-312-d or nicardipine. Histological examination of the brain of SHRSP showed that the arbitrary neurotoxic index (ANI) for stroke lesion dose-dependently decreased with S-312-d at 1, 3, and 10 mg/kg as follows: 4.8, 3.0, 2.3. The ANI for non-treated SHRSP was 7.6. The therapeutic effects of nicardipine (ANI 3.9) at 10 mg/kg corresponded to those of S-312-d at 3 mg/kg. Thus, S-312-d can be recommended for the treatment of cerebral insufficiency or vasospasm following stroke as well as in essential hypertension.

Animals↗

PubMed1992

Lipid peroxidation and myocardial vulnerability in hypertrophied SHR myocardium.

In a comparison using age-matched Wistar-Kyoto rats (WKY), 16-week-old male spontaneously hypertensive rat (SHR) hearts were examined histologically and biochemically on the first and fourth day after administration of 20 mg/kg doxorubicin in order to examine whether membrane abnormalities in hypertrophied SHR myocardium are caused by lipid peroxidation. Morphological examination of the SHR revealed focal myocytolysis on the first day and severe cardiomyopathy involving diffuse myocytolysis and vacuolar degeneration in the left ventricle on the fourth day. The activity of a membrane-related enzyme, Na+/K(+)-ATPase, was already lower in control SHR than that of control WKY and was lower in both SHR and WKY than in the respective saline groups on the first day after administration, whereas the enzyme activity in the doxorubicin-treated SHR was not significantly different from that of the treated WKY. A thiobarbituric acid-reactant substance, a lipid peroxidation marker, was significantly higher in treated SHR than it was in the treated WKY on the first day. Furthermore, in comparison with WKY, alpha-tocopherol in the left ventricle in SHR was significantly lower on the fourth day after administration. These results show that a proneness to lipid peroxidation in the membrane system is closely associated with severity of doxorubicin-induced cardiomyopathy in SHR and suggests that membrane lipid peroxidation may cause a higher degree of vulnerability in hypertrophied SHR myocardium.

5'-Nucleotidase↗

PubMed1992

A comparative study on defense systems for lipid peroxidation by free radicals in spontaneously hypertensive and normotensive rat myocardium.

1. Antiperoxidation ability and lipid peroxidation in myocardium were examined in spontaneously hypertensive rats (SHR) and normotensive Wistar-Kyoto rats (WKY) at 6 and 16 weeks of age. 2. Glutathione peroxidase activity was higher in SHR at 6 weeks of age, but lower at 16 weeks compared to that in WKY. alpha-Tocopherol content was lower in SHR at both 6 and 16 weeks of age than in WKY. 3. In vitro formation of free malondialdehyde was more pronounced in SHR myocardium than in WKY. 4. Coincidence of lower antiperoxidation ability and higher peroxidation of membrane phospholipid indicate myocardial cell vulnerability in SHR hypertrophied myocardium.

Aging↗

PubMed1992

Fall in skin temperature of exercising man.

Fall in skin temperature during initial muscular work was investigated in ten healthy men. Bicycle exercise was performed at workloads of 50-150 W in a climatic chamber at ambient temperatures of 10-40 degrees C (relative humidity 45-55%). Skin temperatures at seven or eight points over the body surface were measured using thermography and thermocouple recording systems. Sweat rates were significantly higher at 40 degrees C than at 30 degrees C, whereas the fall in skin temperature was almost equal. The reduction of skin temperature during exercise was the same throughout the year, although sweat rate was significantly higher in summer than in winter. In coloured thermographics of the skin temperature distribution during exercise of both 50 and 150 W at 10 or 20 degrees C, the skin temperature began to decline immediately at the onset of the exercise. Increased work intensities reduced skin temperature. The results suggest that fall in skin temperature during initial exercise was not due to increased evaporative cooling but to vasoconstriction, probably caused by non-thermal factors.

Bicycling↗

PubMed1991

Sex difference in the pattern of lower limb movement during treadmill walking.

To evaluate the characteristics of stereo-typed movement of the lower limb during treadmill walking, the step length and duration of 200 steps were monitored consecutively and calculated by means of a computerized system, consisting of a position sensor, shoes with foot switches and a minicomputer. Eleven male and 10 female subjects walked at various constant speeds ranging from 60-130 m.min-1. Mean, standard deviation (SD) and coefficient of variation (CV) of the time-distance component at each speed were utilized for the assessment of stereotyped movement. When compared with males, females had a tendency to increase their speed by increasing their cadence. The difference of the walking pattern was specifically related to their height. The SD and CV of the time-distance component at a given speed were significantly greater in females than in males. Regression analyses revealed that in the relationship between the walking speeds and the SDs or CVs of the time-distance component, the significant quadratic equations could be fitted. The speed, at which the SD of step length was minimum, was estimated to be about 90 m.min-1 in both males and females. This was regarded as the free walking speed or as the walking speed resulting from a mechanically efficient step length which suited the subject's body size.

Adult↗

PubMed1991

Decrease of liver glycogen content in golden hamsters infected with plerocercoids of Spirometra erinacei.

Liver glycogen content decreased in golden hamsters experimentally infected with plerocercoids of Spirometra erinacei. The activity of glycogen synthase a decreased significantly in infected animals, whereas that of glycogen phosphorylase a was not significantly affected. These observations suggest that changes in glycogen content were not attributable to increased glycogenolysis, but rather resulted from suppressed glycogenesis. Plasma immunoreactive insulin (IRI) concentrations in infected animals were slightly lower than those in controls, but the differences were not statistically significant. Plasma glucagon concentrations were significantly higher in infected animals. These results suggest that the suppression of glycogen synthase activity in S. erinacei-infected hamsters was attributable to enhanced levels of glucagon and that enhanced secretion of glucagon was caused by parasite-induced hypoglycemia.

Animals↗

PubMed1991

The peritrophic membrane as a barrier: its penetration by Plasmodium gallinaceum and the effect of a monoclonal antibody to ookinetes.

We studied the point at which a monoclonal antibody (mAb C5) to a surface protein (Pgs25) on Plasmodium gallinaceum ookinetes blocked the infection of Aedes aegypti mosquitoes. The antibody did not block the development of zygotes to ookinetes in vitro. Development of ookinetes to oocysts in the mosquito was blocked to the same extent whether zygotes grew to ookinetes in the presence of mAb C5 or the antibody was added after the ookinetes had reached full development. When ookinetes developed in vitro in the presence of mAb C5, antibody remained on the surface of the parasite for the next 50 hr and did not block attachment to the peritrophic membrane. When ookinetes were fed to mosquitoes, two subpopulations of mosquitoes were observed (high numbers of oocysts per midgut and low numbers of oocysts per midgut). mAb C5 reduced the number of oocysts per midgut in the subpopulation that had low numbers of oocysts. The subpopulation that had high numbers of oocysts was unaffected by antibody, indicating that the antibody did not block invasion of the midgut epithelium. When mAb C5 was fed with gametocytes, the parasites invaded the epithelium at the same time (between 30 and 35 hr after the blood meal) as in controls, although at a markedly reduced rate. The ultrastructural observations were consistent with a block of parasites within the peritrophic membrane and not with a block at the epithelium, as parasites were not seen to accumulate within the space between the peritrophic membrane and the epithelium. The mechanism by which mAb C5 to Pgs25 of P. gallinaceum blocks the penetration of the peritrophic membrane remains undefined. We present evidence that the parasite modifies the peritrophic membrane during penetration, an observation first made for Babesia microti during penetration of the peritrophic membrane in Ixodes ticks. Ookinetes in the absence of antibodies appeared to disrupt the layers of the peritrophic membrane, suggesting an enzymatic mechanism for penetration.

Aedes↗

PubMed1991

In vitro effects of berberine sulphate on the growth and structure of Entamoeba histolytica, Giardia lamblia and Trichomonas vaginalis.

The plant alkaloid, berberine sulphate, inhibited the growth of Entamoeba histolytica, Giardia lamblia and Trichomonas vaginalis in BI-S-33 medium, and induced morphological changes in the parasites. Exposure of E. histolytica to berberine caused a clumping of chromatin in the nucleus, and the formation of autophagic vacuoles and aggregates of small vacuoles in the cytoplasm. In berberine-treated G. lamblia, an irregularly-shaped vacuole appeared in the cytoplasm and gradually enlarged during culture. The trophozoites became swollen and deposits of glycogen were seen in the cytoplasm. Trichomonas vaginalis was also affected by the berberine; autophagic vacuoles increased in number soon after exposure, and one large vacuole, which was characteristic of treated cells, appeared. These observations demonstrate that, in vitro, this drug was effective against E. histolytica, G. lamblia and T. vaginalis. Another alkaloid, coptisine, was inactive against the three parasites.

Animals↗

PubMed1991

Comparison of immunochemical specificities of Vibrio parahaemolyticus O10 and O12 antigens using monoclonal antibodies.

The monoclonal antibodies against Vibrio parahaemolyticus O10 and O12 antigens (lipopolysaccharide, LPS) were prepared and specificities of the antibodies were examined. Five of six anti-O10 antibodies reacted with O10 antigen, but none of them reacted with O12 antigen. On the contrary all of the five anti-O12 antibodies reacted with O10 antigen as well as homologous O12 antigen. O10 and O12 antigens were subjected to alkali treatment or periodate oxidation, and reactivities of these chemically modified preparations with the monoclonal antibodies were examined. Reactivities of O10 with anti-O10 and anti-O12 antibodies were reduced by the above two chemical treatments, but that of O12 with anti-O12 was not. O-Deacetylation of O10 LPS by the alkaline treatment was confirmed by NMR spectroscopy. These results suggest contributions to O10-specificity of O-acetyl group and periodate sensitive sugar residue. Inhibition experiments of O10 and O12 homologous precipitations were also carried out with various sugars. From the results we concluded that O10 and O12 antigenic determinants were distinct entities, although O10 and O12 antigens have been reported to be similar and cross-reactive.

Antibodies, Monoclonal↗

PubMed1991

[Functional differentiation of thermoregulation, with particular references to seasonal variation of whole body sweat rate of exercising man].

We investigated the seasonal variation of sweating response during exercise. Four adult healthy men repeated a moderate bicycle exercise (60 watts) in a climatic chamber of an ambient temperature of 30 degrees C (relative humidity, 45%) in winter, spring, summer, and fall. In summer, sweat rate immediately increased as soon as the exercise started, whereas in winter in a few minutes. The mean sweat rate during exercise was significantly different between winter and summer. The transient reduction of the Tsk was observed at the beginning of the exercise in winter. The Tsk decreased in proportion to increasing of sweat rate in each season. Significantly negative correlations were found between sweat rate and the rate of change of Tsk during exercise in each season. The slope and intercept of regression line were significantly different between winter and summer. The index of sweating was made available for the relative value, changing rate against annual mean value of total sweat loss (delta SR, %). The relative value rather than the absolute value (i.e., expressed as g.m-2.h-1) corrected well with skin temperature. It is suggested that the present results may reflect adapted changes in the thermoregulatory mechanisms to seasonal acclimatization. Moreover, the fall in skin temperature during exercise may be not due to increased evaporative cooling, but may be the result of vasoconstriction probably caused by non-thermal factors.

Acclimatization↗

PubMed1991

Effects of tryptophane on SHRSP offspring growth.

The effects of tryptophane on growth and hypertension of offspring obtained from mothers given L-tryptophane prior to mating: In the tryptophane group, body weights were heavier and blood pressures were higher than in the control group. Stroke lesion incidence rates were also much higher in the tryptophane group. At 20 weeks of age, brain enzyme activities were lower and serotonin content was higher in the tryptophane group in comparison with the control. These results suggest that dietary tryptophane may affect precocious maturation and as well as affect elevation in blood pressures due to brain serotonin turnover.

Animals↗