Biomedical subjects

Jun Sato

Publications and source records attributed to Jun Sato.

64 records · Page 4Linked to original sources

PubMed2003

The plasma superoxide scavenging activity in canine cancer and hepatic disease.

To clarify the relationship between plasma antioxidant activity and diseases in dogs, plasma samples were collected from 6 healthy dogs and 16 diseased dogs (6 dogs with cancer, 5 dogs with hepatic disease, and 5 dogs with inflammation ), and measured superoxide anion scavenging activities. Antioxidant activities of canine plasma were evaluated by measuring their superoxide anion (O(2)(-.)) scavenging activities with electron spin response spectroscopy combined with spin trapping reagent, 5,5-dimethyl-1-pyrroline-N-oxide (DMPO). Total O(2)(-.) scavenging activities in the presence of plasma of diseased dogs tended to be higher than those in healthy controls, especially significant higher activities in the presence of canine plasma of hepatic disease and inflammation were observed. In diseased dogs, KCN-insensitive activities, suggesting the activity of manganese-containing superoxide dismutase (Mn-SOD), were significantly higher than those in healthy controls. Therefore, it seems that there is a possibility of utilizing of plasma O(2)(-.) scavenging activity as one of clinical indicators for oxidative-related diseases such as cancer, hepatic disease and inflammation in dogs.

Animals↗

PubMed2002

Lowered response threshold and increased responsiveness to mechanical stimulation of cutaneous nociceptive fibers in streptozotocin-diabetic rat skin in vitro--correlates of mechanical allodynia and hyperalgesia observed in the early stage of diabetes.

Rats rendered diabetic by streptozotocin (STZ) show allodynia and hyperalgesia and thus, have been offered as a model of pain in diabetic neuropathy. However, recent electrophysiological studies on these rats found that C-fiber nociceptors were not consistently hyperexcitable to mechanical stimulations by von Frey hairs and that there was no change in their response thresholds. In the present study, we used rat skin-saphenous nerve in vitro preparations, in which the receptive fields of identified single C-polymodal receptors (CPRs) can be accurately stimulated with a servo-controlled mechanical stimulator. Single fiber recordings from CPRs were performed in diabetic rats with an increased behavioral nociceptive response 7-19 days after STZ injection. The proportion of units with spontaneous activity and the magnitude of this activity increased in the diabetic preparations. The response thresholds of CPRs were significantly decreased with ramp-pressure stimulation and their response magnitude to the suprathreshold stimulation was significantly increased in diabetic rats. In addition, the response pattern to mechanical stimulation was also changed to a non-adapting type. These findings suggest that changes in CPRs contribute to the enhanced nociception observed in the early stage of diabetic neuropathy.

Animals↗

PubMed2002

Tissue glucose level modulates the mechanical responses of cutaneous nociceptors in streptozotocin-diabetic rats but not normal rats in vitro.

The maintenance of normoglycemia has been reported to reduce painful sensations in diabetic subjects. This suggests that lowering the tissue glucose concentration might inhibit the increased cutaneous nociceptor activities seen in a diabetic conditin. To test this hypothesis, we studied the effect of changing the glucose concentration in the superfusate of in vitro preparations (high, HG: 20 mM or normal glucose, NG: 6.7 mM) on the mechanical response of C-fiber polymodal receptors (C-polymodal receptors). Single fiber activities of C-polymodal receptors were recorded from skin-nerve in vitro preparations of streptozotocin-induced diabetic and age-matched control rats. Pressure stimulation was applied to the receptive field by a servo-controlled mechanical stimulator. C-polymodal receptors from diabetic preparations superfused with HG-solution showed increased spontaneous activity, lowered response threshold, increased response magnitude and a less adaptive response pattern to mechanical stimulation compared with those from control preparations superfused with NG-solution. C-polymodal receptors from diabetic preparations superfused with NG-solution showed no such changes. The responsiveness of C-polymodal receptors from control preparations was not different in NG- or HG-conditions. These data demonstrated that normalization of the glucose concentration normalized the responsiveness of C-polymodal receptors in diabetic animals. This response may be associated with the fact that normoglycemia reduces painful sensations in diabetic subjects.

Action Potentials↗

PubMed2002

The expression of vascular endothelial growth factor in synovial tissues in patients with internal derangement of the temporomandibular joint.

OBJECTIVE: The aim of this study was to elucidate the expression and localization of vascular endothelial growth factor (VEGF) in synovial tissue taken from the temporomandibular joint (TMJ) with internal derangement (ID) and discuss the role of VEGF in the pathogenesis of ID. STUDY DESIGN: Through the use of an immunohistochemical technique, 39 TMJs in 37 patients were examined. As controls, synovial tissue specimens from 6 joints in 6 patients with habitual dislocation were also examined. RESULTS: In the synovial tissue from 35 of the patients with ID, expression of VEGF was observed in the synovial lining cells, in the endothelial cells of the blood vessels, and in the fibroblasts. In contrast, expression of VEGF was found in the TMJ tissue from only 2 of the controls. The percentage of VEGF-positive cells in the ID specimens was significantly higher than that in the habitual dislocation specimens (P < .02), and the expression of VEGF significantly correlated with the arthroscopic synovitis score (P = .004). CONCLUSION: These results suggest that the expression of VEGF is upregulated and involved in the development of inflammatory changes in synovial tissues in TMJs with ID.

Adolescent↗

PubMed2002

Clinical availability of urinary N-acetyl-beta-D-glucosaminidase index in dogs with urinary diseases.

Urinary excretion of N-acetyl-beta-D-glucosaminidase (NAG) was examined in healthy dogs and dogs with urinary diseases, and its clinical usefulness as an indicator of urinary diseases was discussed. Twenty-eight healthy dogs and 20 dogs with urinary diseases were used. Urinary NAG activity was measured using p-nitrophenyl N-acetyl-beta-D-glucosaminide as substrate, and expressed as units per gram of urinary creatinine (NAG index). Urinary NAG index in urine of healthy dogs was 3.2+/-2.4 U/g, and NAG index in the dogs with chronic renal failure or lower urinary tract infection accompanied by pyelonephritis was higher than that in healthy dogs. However, the dogs with lower urinary tract infection without pyelonephritis showed normal values of NAG index. Some dogs with diabetic mellitus showed elevated values of NAG index when control of blood sugar was not successful. Increase of NAG index was observed in some dogs with pyometra before increases of BUN and serum creatinine concentration. Therefore, NAG index in urine seems to be a good indicator for urinary diseases in dogs.

Acetylglucosaminidase↗

PubMed2002

Urinary excretion of N-acetyl-beta-D-glucosaminidase and its isoenzymes in cats with urinary disease.

The present study was designed to assess the clinical usefulness of measurement of urinary N-acetyl-beta-D-glucosaminidase (NAG) activity and its isoenzymes in cats with urinary disease. Thirty-five healthy cats and 9 cats with renal disease were used. Furthermore, a 5-year-old female cat was administered a large amount of sulfonamide in order to induce acute renal failure, and urine samples were collected for the assay of NAG activity and its isoenzymes. Urinary NAG activity was measured using p-nitrophenyl N-acetyl-beta-D-glucosaminide, and expressed as units per gram of urinary creatinine (NAG index). Urinary NAG isoenzymes were assayed by use of the mini-column method and electrophoresis. The overall mean value of urinary NAG index in healthy cats was 1.6+/-1.5 U/g. Urinary NAG index varied from 6.2 to 35.5 U/g in cats with chronic renal failure. There was no significant correlation between BUN, serum creatinine concentration and urinary NAG index. In cats with feline lower urinary tract disease, normal values of urinary NAG index were observed. In the urine samples of healthy cats, the proportions of NAG isoenzyme A (NAG-A) and isoenzyme B (NAG-B) were 79.1+/-4.4% and 21.0+/-4.4%, respectively, as assayed by the mini-column method. In the assay of NAG isoenzymes by electrophoresis, the proportions of NAG-A and NAG-B in healthy cats were 66.6+/-5.8% and 33.4+/-5.8%, respectively. The proportion of NAG-B as measured by electrophoresis was significantly larger (p<0.05) than that obtained with the mini column method. A feline case of acute renal failure experimentally-induced by sulfonamide showed elevation of urinary NAG index, NAG-A and NAG-B after injection of sulfonamide. The increase in NAG-B was larger than that of NAG-A. From the results reported here, measurement of urinary NAG and its isoenzymes seems to yield information about tubular damage at an early stage in cats with urinary disease.

Acetylglucosaminidase↗

PubMed2002

Serum activities of tartrate-resistant acid phosphatase and bone specific alkaline phosphatase as indices of bone metabolism in the cow.

The correlation between the serum hydroxyproline concentration and serum activity levels of TRAP and BALP was examined in 41 cows. The correlated coefficient (r) was 0.6391 for TRAP and 0.3147 for BALP, respectively. Judging from the significant correlation to the serum hydroxyproline concentration, serum TRAP activity is an index for bone metabolism in cows. Serum TRAP activity was therefore measured in 205 healthy cows (2-9 years old) in order to observe the changes in bone resorption with aging and milk production. TRAP levels differed slightly between group A (< or =4 yrs) and B (5 yrs< or =) at the same stage of lactation. The activity levels rose slightly at the height of lactation stage and during the dry stage.

Acid Phosphatase↗

PubMed2002

Idiopathic thrombocytopenia in Japanese black cattle.

A female Japanese Black cow showed hemorrhage under the mucous membrane of the eye conjunctiva and the vagina, and thrombocytopenia in peripheral blood. The clinical manifestations repeated spontaneously during long-term observation. The clinical findings were stable except for severe periodic bleeding. Prothrombin time, activated partial thromboplastin time and fibrinogen levels were normal. The anti-platelet antibody in the serum was analyzed by indirect platelet coagulation tests. Because the platelets in the micro-plate wells of the subject series showed coagulation up to 1:128, it was judged that anti-platelet antibody was present in the serum. A number of megakaryocytes were recognized in smear samples obtained from bone marrow of the scapula immediately after euthanasia. Therefore, this case was diagnosed as idiopathic thrombocytopenia.

Animals↗

PubMed2002

Effects of adrenoceptor antagonists on the cutaneous blood flow increase response to sympathetic nerve stimulation in rats with persistent inflammation.

There is some evidence that the sympathetic nervous system plays a role in the development and/or maintenance of painful states, and that sympathetic nervous function is altered in these conditions. Our previous experiments showed that electrical stimulation of the lumbar sympathetic trunk (sympathetic stimulation: SS), which normally induces a decrease in blood flow (BF) of plantar skin, induced its BF increase in about 50% of adjuvant-inflamed rats. To investigate the mechanism of this BF-increase response, we examined whether noradrenaline (NA) plays any role in this changed response to SS, and which receptor subtype is involved. We measured paw cutaneous BF response with a laser Doppler flowmeter in rats chronically inflamed with complete Freund's adjuvant. SS induced the BF-increase response in 50-67% of measured sites. Close-arterially injected NA induced the BF-increase response at dosages between 10-100 ng/kg only at the sites with the BF-increase response to SS. The BF-increase and -decrease responses to NA was significantly reduced after the close-arterial injection of either alpha1- or alpha2-adrenoceptor antagonists (p lt; 0.05, respectively). In contrast, although the BF-decrease responses to SS were significantly reduced by administration of alpha1- and alpha2-adrenoceptor antagonist, BF-increase response was reduced only by alpha1-adrenoceptor antagonist, and that only at a higher dose. In addition, the beta-adrenoceptor antagonist had no effects on both responses. These results suggest that the BF-increase response to SS involves, additionally to NA, a non-adrenergic mechanism.

Adrenergic Antagonists↗

PubMedDate not supplied

Mean corpuscular volume (MCV) and the risk of colorectal adenoma in menopausal women.

BACKGROUND/AIMS: It has been reported that alcohol intake and folate deficiency are associated with an increased risk of colorectal adenomas and carcinomas. Mean corpuscular volume is increased under these conditions. We have reported that the mean corpuscular volume was higher in patients with adenoma than without adenoma in middle-aged men. The aim of this study was to assess the association between mean corpuscular volume and risk of colorectal adenoma in menopausal women. METHODOLOGY: The subjects were 415 menopausal women who underwent both barium enema examination and total colonoscopy, and their blood samples were analyzed. The subjects were divided into two groups with or without adenoma, and were divided into four groups according to the mean corpuscular volume value. Various variables were compared among the groups, and the odds ratios of adenoma were calculated. RESULTS: The mean corpuscular volume was higher in patients with adenoma than without adenoma (P = 0.002). As for the mean corpuscular volume value, the odds ratio (95% CI) of patients with adenoma was 1.00 (referent); (mean corpuscular volume (fl) < 90), 1.50 (0.93-2.07); (> or = 90 but < 92.5), 1.52 (0.97-2.07); (> or = 92.5 but < 95) and 2.87 (2.25-3.45); (> or = 95). CONCLUSIONS: Mean corpuscular volume > or = 95 may be used as an index of the risk for colorectal adenomas in menopausal women.

Adenoma↗