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Biomedical subjects

M Kondo

Publications and source records attributed to M Kondo.

At least 937 records · Page 52Linked to original sources
PubMed1989

Measurements of gaze movements while driving.

In this study, gaze movements of drivers driving through an intersection were investigated. Gaze movements of drivers in large vehicles were compared with those in small vehicles. There were both similarities and differences in the visual search behaviors of drivers of large and small vehicles. The two groups were similar in that, when approaching an intersection, drivers made repeated saccadic gaze movements; after entering the intersection, saccadic gaze movements were directed ahead in the direction of turning. Differences arose in the frequency and distribution of gaze movements. The number of gaze movements was significantly greater in drivers of large vehicles. The distribution of gaze movements in driving a large vehicle showed a peak at the point 50 to 60 degrees to the right and left of the median plane of the driver. The distribution of gaze movements of drivers of small vehicles showed no peak across the visual field.

Adult↗
PubMed1989

Role of lipid peroxidation and oxygen radicals in compound 48/80-induced gastric mucosal injury in rats.

Repeated administration of a small dose of compound 48/80 induced acute gastric mucosal injury in rats. Thiobarbituric acid (TBA) reactants in the gastric mucosa were significantly increased and serum alpha-tocopherol was significantly decreased after the treatment. The total area of gastric lesions and the increase in TBA reactants in the gastric mucosa were significantly reduced by pretreatment with superoxide dismutase (SOD) and/or catalase, allopurinol and anti-rat polymorphonuclear leukocytes (PMN) antibody. Lipid peroxidation and oxygen radicals derived from both the xanthine-xanthine oxidase system and PMN may be involved in the pathogenesis of compound 48/80-induced gastric mucosal injury.

Animals↗
PubMed1989

Role of free radicals and lipid peroxidation in gastric mucosal injury induced by ischemia-reperfusion in rats.

Ischemia and reperfusion are of the greatest importance in the pathology of many diseases. We investigated the roles of oxygen-derived free radicals and lipid peroxidation in gastric mucosal injury, such as spotty and linear hemorrhagic erosions, induced in rats by ischemia-reperfusion. The gastric mucosal injury and the increase in thiobarbituric acid (TBA) reactants in the gastric mucosa induced by ischemia-reperfusion were significantly inhibited by treatment with SOD and catalase. These results suggest that oxygen-derived free radicals and lipid peroxidation play important roles in the pathogenesis of acute gastric mucosal lesions induced by ischemia-reperfusion.

Animals↗
PubMed1989

Pathogenesis of platelet-activating factor-induced gastric mucosal damage in rats.

Platelet-activating factor (PAF), given intravenously, induced erosions and hyperemia to the rats stomachs. Gastric mucosal blood flow was decreased and thiobarbituric acid (TBA) reactants (an index of lipid peroxidation) in the gastric mucosa were increased 10 min after PAF injection. Superoxide dismutase plus catalase reduced the gastric mucosal lesions and TBA reactants, but had no influence on gastric mucosal blood flow. A reduction in the number of circulating polymorphonuclear leukocytes (PMN) reduced the gastric mucosal damage and TBA reactants, and inhibited the decrease in gastric mucosal blood flow, as observed 30 and 60 min after PAF injection. PAF induced superoxide production by rat PMN and enhanced that stimulated by opsonized zymosan or phorbol myristate acetate. These results suggest that microcirculatory disturbance and oxygen-derived free radicals generated by PMN play important roles in gastric mucosal lesions induced by PAF.

Animals↗
PubMed1989

Role of oxygen-derived free radicals in gastric mucosal injury induced by ischemia or ischemia-reperfusion in rats.

Oxygen-derived free radicals have been implicated as possible mediators in the development of tissue injury induced by ischemia and reperfusion. Clamping of the celiac artery in rats reduced the gastric mucosal blood flow to 10% of that measured before the clamping. The area of gastric erosions and thiobarbituric acid (TBA) reactants in gastric mucosa were significantly increased 60 and 90 min after clamping. These changes were inhibited by treatment with SOD and catalase. Thirty and 60 min after reoxygenation. produced by removal of the clamps following 30 min of ischemia, gastric mucosal injury and the increase in TBA reactants were markedly aggravated compared with those induced by ischemia alone. SOD and catalase significantly inhibited these changes. The serum alpha-tocopherol/cholesterol ratio, an index of in vivo lipid peroxidation, was significantly decreased after long periods of ischemia (60 and 90 min), or after 30 and 60 min of reperfusion following 30 min of ischemia. These results indicated that active oxygen species and lipid peroxidation may play a role in the pathogenesis of gastric mucosal injury induced by both ischemia alone and ischemia-reperfusion. Although, allopurinol inhibited the formation of gastric mucosal injury and the increase in TBA reactants in gastric mucosa, the depletion of polymorphonuclear leukocytes (PMN) counts induced by an injection of anti-rat PMN antibody did not inhibit these changes. As compared with the hypoxanthine-xanthine oxidase system. PMN seem to play a relatively small part in the formation of gastric mucosal injury induced by ischemia-reperfusion.

Allopurinol↗
PubMed1989

[Megakaryocyte ploidy in patients with myelodysplastic syndrome--by microcytofluorometry with DAPI staining after removal of Wright-Giemsa staining].

In the myelodysplastic syndrome (MDS) patients the ploidy distribution of megakaryocyte DNA was rarely reported. We applied DAPI (4',6-diamidino-2-phenylindole) staining for measuring nuclear DNA content in megakaryocytes which have been morphologically identified on the Wright-Giemsa stained smear in 8 normal subjects and 12 MDS patients. Briefly, megakaryocytes morphologically examined on a Wright-Giemsa stained smear were photographed, and were located. We then removed the Wright-Giemsa stains by immersing it in 50% ethanol, 37 degrees C for 1 hour and 100% methanol, 37 degrees C for 1 hour. The DAPI staining was performed in DAPI solution (DAPI 0.01 mg/ml, pH 7.4 Tris-EDTA-2 Na buffer solution and 0.01 mol 2-mercaptoethylamine hydrochloride were mixed at the ratio of 0.5: 98.5: 1.0) for more than 30 min. The amount of nuclear DNA in the megakaryocyte previously identified was measured by cytofluorometry. The population of megakaryocyte in the normal subjects was the largest in the 16N, and in the 10 cases of the 12 MDS patients was the largest in the 8N, in the other 2 cases was the largest in the 4N. These results represent the development of the megakaryocyte nucleus in the MDS patients may be disturbed.

Adult↗
PubMed1989

[Microcytofluorometrical measurement of DNA content in immunologically identified micromegakaryocytes of human bone marrow].

We have developed a method to microfluorometrically determine the amount of DNA in immunologically identified micromegakaryocytes on bone marrow smears. Bone marrow smears were fixed with acetone-formalin buffer and immunostained with a monoclonal anti-GPIIb/IIIa antibody, followed by FITC conjugated anti-mouse IgG. After the smears were re-fixed with methanol, DAPI (4', 6-diamidino-2-phenylindole) staining was performed. Using an automatic Digital-Microfluorometer (Olympus MMSP-FR-II), megakaryocytes on the smears were identifies by the GPIIb/IIIa immunofluorescence and, after changing the barrier filters, their nuclear DNA content was measured by the intensity of DAPI fluorescence, which is proportional to the amount of DNA. Using this method, we found that the DNA histogram of the megakaryocytes from a patient with myelodysplastic syndrome showed a shift to small ploidy compared with normal controls. This method may be valuable in the measurement of the megakaryocyte DNA content.

Adult↗
PubMed1989

[Clinicopathological study on multiple primary malignant neoplasms, related to the oral-maxillofacial region].

The present study consists of a clinical and histopathological analysis of those cases which were diagnosed as multiple primary malignant neoplasms of the oral-maxillofacial region and the other organs. 9 patients of those multiple primary malignant neoplasms out of 261 patients of malignant neoplasms in the oral-maxillofacial region, who visited in out department from 1975 to 1986, were detected. 3.4% of the incidence rate was calculated. All the cases were male, and these included each 1 case of triple and quadruple. 7 cases were detected prior in the oral-maxillofacial region to the other organs. There seemed to be a preponderance to early detection of a neoplasm in the oral-maxillofacial region. Therefore, the possibility of multiple primary malignant neoplasms should be kept in mind in the routine clinical activities. 2 cases were synchronous, 6 months or less interval between the first and the second neoplasms, the others were metachronous, averaged 5-year interval. The primary sites in the oral-maxillofacial region were tongue (3 cases), floor of the mouth (2), buccal mucosa (2), lower gingiva (1), maxillary sinus (1), all of them were diagnosed as squamous cell carcinomas, histopathologically. The other organs were esophagus (3 cases), stomach (2), colon (2), lung (2), liver (1), urinary bladder (1), hypopharynx (1). Histopathological diagnoses of them were squamous cell carcinomas (3 cases of esophagus, each 1 case of lung, urinary bladder, and hypopharynx), adenocarcinomas (2 cases of stomach and colon, and 1 case of lung), and a hepatoma. It's necessary to differentiate the multiple primary malignant neoplasms from metastases when each of them were diagnosed as squamous cell carcinomas.(ABSTRACT TRUNCATED AT 250 WORDS)

Head and Neck Neoplasms↗
PubMed1989

[Color change by thickness and background color on visible light-cured composite resins].

The effects of thickness and background color on the color of five commercial light-cured composite resins were studied by a dental color meter using the CIE 1976 L*a*b* color system. As thickness increased from 1.0 to 4.0 mm, values of L*a*b* decreased for white and dentin color background but showed no obvious difference in color for a black background. the color of composite resins were not in fluenced by background color in a thickness of 4.0 mm. The values of color difference for 1.0 and 2.0 mm thick samples have a larger value than the same 4.0 mm samples. The color difference was recognized even for the same shade name in five representative kinds of composite resins.

Color↗
PubMed1989

[Chemoembolization with degradable starch microspheres for liver metastases in colorectal cancer].

Transcatheter chemoembolization using Degradable Starch Microspheres (DSM) was performed in 17 patients with liver metastases of colorectal cancer. Mitomycin C mixed with DSM was injected into the proper hepatic artery. Tumor regression of over 50% was observed in 9 of 17 cases (53%). Elevated serum CEA levels (greater than 10 ng/ml) decreased in 10 of 15 cases (67%). One-year survival rate was 50% in 17 cases. One-year survival rate was 100% in 7 cases with several liver metastases (H2). Abdominal pain occurred in 36%, mostly disappearing within 2 hours. No major side effects such as bone marrow suppression or hepatotoxicity were observed. Our results suggest that chemoembolization using DSM is effective and safe in the treatment of liver metastases from colorectal cancer.

Colorectal Neoplasms↗
PubMed1989

Mechanism of polymorphonuclear leukocytes accumulation examined using inhibitors of complement and arachidonic acid cascade in rats treated with OK-432.

When the streptococcal preparation OK-432 was intraperitoneally injected for the treatment of carcinomatous peritonitis, antitumor polymorphonuclear leukocytes (PMNs) accumulated in the peritoneal cavity. We examined the mechanism of this PMN accumulation using an in vivo system in rats. FUT-175, EDTA and K76 inhibited C5a generation by OK-432 in vitro, but EGTA, prednisolone and inhibitors of arachidonic acid cascade did not. In in vivo experiments, EDTA, FUT-175, antirat C3 serum and K76 reduced the accumulation of PMNs onto filter membranes, when these reagents were reacted with OK-432 for 3 h through filter membranes placed on the turned rat peritoneum. EGTA failed to inhibit PMN accumulation. Prednisolone, indomethacin, OKY046 and AA861 inhibited PMN accumulation in a dose-dependent manner. These inhibitions of PMN accumulation were confirmed by histological examination. It was concluded that complement-derived chemotactic factor C5a generated by OK-432 induced PMN accumulation in association with chemotactic arachidonic acid metabolites.

Animals↗
PubMed1989

[Changes of complement in immune complex glomerulonephritis induced by cationized antigen].

Complement system takes an important role in the pathogenesis of immune complex glomerulonephritis. In this study the precise changes of serum complement and its deposition in the glomeruli were investigated in the mice models induced with cationized bovine gamma-globulin (CBGG). Balb/c mice preimmunized with CBGG were injected intravenously with CBGG three times every 24 hours. Proteinuria and hypoalbuminemia have developed from day 3 until the death on day 9-13 of progressed azotemia. This nephritis resembled to mesangial proliferative glomerulonephritis histopathologically. Immunofluorescent study revealed granular deposits of CBGG, IgG, A, M and C3 along the glomerular capillary loop. Serum C3 decreased to about 50% of normal controls within 1 hour after challenge of antigen and plasma C3 conversion evaluated by crossed-immunoelectrophoresis, occurred in accordance with C3 reduction and then decreased. Immunofluorescent study showed a big difference in the mode of deposition among IgG, CBGG and C3. The most intense deposits of C3 in the glomeruli were seen 12 hours after challenge of CBGG, and then gradually decreased until the next challenge. IgG and CBGG antigen deposited most intensely soon after the challenge of antigen, and gradually decreased. These results led us to conclude that there existed two phases of complement activation in this immune complex induced mice glomerulonephritis; an early phase activation of complement by antigen-antibody complexes in the circulation and later phase activation of complement by immune complexes after deposition of them in situ glomeruli.

Animals↗
PubMed1989

[Experience and logic of breast conservation therapy].

One hundred patients with an operable breast cancer were treated with intent of breast conservation in six years. Five patients developed contralateral breast cancers synchronously or metachronously. Therefore, a total of 105 breasts were treated. T1 tumors were seen in 55 breasts, T2 tumors in 45, and T3 in 5. Breast conservation were possible for 95 breasts: 52 with T1 tumors,+ 41 with T2, and 2 with T3. No patients have relapsed yet. There is great concern or even fear for breast conservation among surgeons. We discuss about several issues concerning surgical margin, intraductal carcinoma, multicentricity, radiation injuries including carcinogenesis, racial difference of curability, etc., and try to establish the logic of doing or not-doing this treatment which has been proven by randomized clinical controlled trials. Reasons for conservative attitude expressed by the surgeons are irrelevant or illogical. We conclude that it now is the responsibility for the surgeons to prove survival benefit if they would continue to perform mutilating surgery such as Halsted operation.

Breast Neoplasms↗
PubMed1989

[Chemo-embolization using degradable starch microspheres and regional hyperthermia in unresectable hepatocellular carcinoma].

Antitumor effects and prognosis of the patients with unresectable hepatocellular carcinoma were investigated in the treatment of chemo-embolization using degradable starch microspheres (DSM) and regional hyperthermia. Twenty-six cases were treated with chemo-embolization using DSM alone (Group A) and eighteen cases were treated with combination of chemo-embolization and hyperthermia (Group B). Tumor regression rates over 50% were 42% (11/26) and 56% (10/18) in Group A and Group B, respectively. In the patients with tumors over 7 cm in diameter, no favorable response was obtained in Group A (0/11), but the response rate was increased to 56% (5/9) by the combination of hyperthermia. In the patients with arterio-portal shunt, therapeutic effects were observed in 17% (1/6) and 50% (1/2) of Group A and Group B, respectively. In the patients with portal invasion (Vp2 and Vp3), no favorable response was demonstrated in Group A (0/4), but tumor response was demonstrated in one out of 3 cases in Group B. One- and two-year survival rates were 59% and 53%, respectively, in Group A, and 93% and 45%, respectively, in Group B. The DSM, temporary embolus, is suitable for the combination of hyperthermia because chemo-embolization using DSM can be performed many times. Therefore, these results suggested that chemo-embolization using DSM should be beneficial as combination therapy for unresectable hepatocellular carcinoma.

Carcinoma, Hepatocellular↗
PubMed1989

Interaction of S-activated enkephalin analogs with opiate receptors.

Enkephalin analogs containing a thiol activated by a thiomethyl (SCH3)*** or 3-nitro-2-pyridinesulfenyl (Npys) group were synthesized. Incubation of such S-activated enkephalin analogs as [D-Ala2, Leu(CH2S)SCH(3)5]enkephalin or [D-Ala2,Leu(CH2S)Npys5]enkephalin with guinea pig ileum (GPI) resulted in the continuous stimulation of the mu opiate receptors. This sustained GPI-activity was completely reversed with the antagonist naloxone, while subsequent washings elicited again the full enkephalin activity. When GPI showing full enkephalin activity was incubated with 1 mM dithiothreitol, about 70% of the activity was eliminated. Examination of enkephalin analogs containing Cys(Npys) at position 1, 5, or 6 suggested that no other thiols occur near the enkephalin binding site of the mu receptor. From these results, it is considered that only one thiol group exists near the binding site of the mu receptor in GPI. Similar results were also obtained for the mu receptors in mouse vas deferens.

Animals↗
PubMed1989

[Influences of anti-allergic drugs on superoxide generation from the hypoxanthine-xanthine oxidase system or polymorphonuclear leukocytes].

The influences of anti-allergic drugs on superoxide generation from the hypoxanthine-xanthine oxidase system or polymorphonuclear leukocytes (PMN) were studied by an electron spin resonance assay using 5,5-dimethyl-1-pyrroline-N-oxide (DMPO) as a spin trapper. The intensity of DMPO-OOH signal generated from the hypoxanthine-xanthine oxidase system was not influenced by the presence of azelastine, ketotifen, disodium cromoglycate, mequitazine, or methylprednisolone, but it decreased in the presence of AA-673. A kinetic study showed that the second order rate constant for reaction between AA-673 and superoxide anion at pH 7.4 was 2.9 x 10(8)M-1S-1. The relative intensity of DMPO-OOH spin adduct generated from PMN stimulated with phorbol myristate acetate (PMA) or opsonized zymosan (OZ) significantly decreased in the presence of azelastine: from the PMN-PMA system, with 10.7 microM concentration of molar concentration causing 50% reduction of the signal intensity (IC50), while from the PMN-OZ system, with 10.5 microM concentration of IC50, and also decreased in the presence of mequitazine: from the PMN-PMA system, with 10.8 microM concentration of IC50, while from the PMN-OZ system, less than 2.0 microM concentration of IC50. These results suggest that some anti-allergic drugs may have anti-inflammatory and anti-oxidative actions due to scavenging superoxide radicals or due to inhibiting superoxide production.

Aminopyridines↗
PubMed1989

Fungal flora in rainwater.

We analyzed rainwater samples collected throughout a year for fungal flora and compared the results to those from atmospheric samples. Differences between the seasonal variation in number of fungi in rainwater and that in number of fungi in the atmosphere were found; that is, there was less of a difference among rainfall samples from different sampling points than among atmospheric samples. In the rainwater samples 29 fungal genera were detected, whereas only 17 were detected in the atmospheric samples. The variations in Cladosporium and Penicillium were the determinants of the total number of fungi in rainwater, whereas in air the variation in Cladosporium alone was the determinant. Sampling of rainwater therefore can be expected to provide information on fungal flora in the troposphere that cannot be obtained by means of air sampling.

Air Microbiology↗