Biomedical subjects

K Ohmori

Publications and source records attributed to K Ohmori.

At least 127 records · Page 7Linked to original sources

PubMed1999

The effect of erdosteine and its active metabolite on reactive oxygen species production by inflammatory cells.

OBJECTIVE: We examined the effect of erdosteine (KW-9144), an expectorant, and related compounds on inflammatory cell-derived reactive oxygen species which are involved in airway inflammation. METHODS: Neutrophils were isolated from peritoneal lavages of casein-injected rats and from peripheral blood of healthy human donors. Eosinophils were isolated from peritoneal lavages of horse serum-injected guinea pigs. These cells were stimulated with phorbol 12-myristate 13-acetate (PMA) and the production of reactive oxygen species was measured with luminol-dependent chemiluminescence (LDCL). RESULTS: M1, an active metabolite of erdosteine, significantly inhibited PMA-induced LDCL of the all cell populations with treatment before stimulation. The effects of S-carboxymethylcysteine (S-CMC), ambroxol and N-acetylcysteine (NAC) on the LDCL response were weaker than those of M1. Furthermore, PMA-induced LDCL was decreased by posttreatment with M1. CONCLUSION: These results suggest that M (an active metabolite of erdosteine) may exert an antiinflammatory effect by scavenging inflammatory cells-derived reactive oxygen species.

Animals↗

PubMed1999

Radiographic evaluation of the lumbosacral disc height.

OBJECTIVE: To establish criteria for the radiographic evaluation of narrowing of the L5-S1 disc height, which varies widely with transition of the L5 vertebra. DESIGN AND PATIENTS: Nondegenerated disc heights of L3-4 to L5-S1 and the thickness and length of the L5 transverse process were measured on plain radiographs of the lumbar spine in 166 outpatients, aged 18-35 years (mean 26.3 years), in whom at least the L3-4 and L5-S1 discs both showed normal signal intensity on magnetic resonance imaging. The level of the iliac crest was recorded semiquantitatively. The disc height was expressed as a percentage of the L3-4 disc height, namely "relative disc height". The ratio of disc height to the sagittal diameter of the overlying vertebral body was termed the "disc height index". RESULTS AND CONCLUSION: The relative disc height and disc height index of L5-S1 showed strong negative correlations with two anatomic variables, which were the relative thickness of the transverse process and the level of the iliac crest (P<0.0001). The results of linear regression analysis suggest that narrowing of the L5-S1 disc height can be evaluated on plain radiographs alone in relation to these anatomic variables.

Adolescent↗

PubMed1999

Further characterization of memory T cells existing in a case of CD8 deficiency.

CD8 deficiency is a rare primary immunodeficiency caused by a defect of ZAP-70, which plays a pivotal role in T cell activation. We previously reported the existence of memory phenotype-CD4+ T cells in a case of CD8 deficiency, which demonstrates that activation signals through ZAP-70 are not essential to the phenotypic conversion of T cells from "naive" to "memory." In this study, we further characterized CD45RO+ T cells in a CD8 deficient patient. We showed that the patient's CD45RO+ T cell population had a wide variety of T cell receptor Vbeta-chain gene usage, and contained few clonally expanded T cells, while many clonally expanded T cells were present in the memory T cell population of age-matched healthy children. These results suggest that various kinds of antigens were involved in the differentiation of the patient's T cells, and that the differentiation into memory T cells was not accompanied by profound T cell proliferation. Moreover, our findings confirmed that the patient's CD45RO+CD4+ T cells had acquired effector-cytokine producing ability, indicating that there exists an alternative activation pathway which is independent of ZAP-70 for the acquisition of effector-cytokine producing ability.

CD8 Antigens↗

PubMed1999

Enhancement of ultrasound-accelerated thrombolysis by echo contrast agents: dependence on microbubble structure.

The combination of ultrasound (US) exposure and ultrasound contrast agent (UCA) further increases the amount of drug-mediated thrombolysis. The aim of this study was to examine the efficacy of the combination of US and UCA on tissue plasminogen activator (tPA) thrombolysis, and the dependence on the microbubble structure. A catheter-type transducer capable of US emission (10 MHz, spatial peak temporal average intensity = 1.02 W/cm2 and peak negative pressure = 0.33 MPa) in the continuous-wave mode was employed. In 28 artificial white thrombi, serial changes in acoustic properties monitored by echography and histopathology during the tPA-mediated thrombolysis were analyzed. The thrombi were assorted to 4 groups; UCA nontreated (Control), sonicated albumin (A)-, SH-U508A (SH)- and dodecafluoropentane emulsion (DDFP)-treated groups. Persistence of microbubble opacification and thrombus weight were also measured. After the sample was suspended in a beaker with tPA (8000U) and 100 mL of saline, the UCA was administered and the mixture exposed to US for 10 min. Weight reduction of the thrombus was greatest in the DDFP Group (-49 +/- 8%), and that in the A Group (-8 +/- 5%) was not significantly different from that in the Control Group (-5 +/- 1%). The persistence of the microbubbles expressed as the decay of the time-intensity curve, was longest in the DDFP Group. The echo intensity of the superficial layer of the thrombus exposed to US was high and weight loss was marked. Multiple cavity formation was observed histopathologically. The stability of the microbubbles was an important factor of the US and UCA enhancement effect on tPA-mediated thrombolysis. This combination therapy has potential for clinical application in patients with thrombotic arterial and venous occlusion and left arterial thrombus.

Adult↗

PubMed1999

Dependence of power Doppler image on a high pass filter instrumented in ultrasound machine.

The aim of this study was to examine the influence of flow velocity, beam incident angle and a wall motion filter on the intensity of power Doppler image of steady flow in vitro. Power Doppler images of flow were recorded using a 7.5-MHz linear transducer with the fixed repetition frequency, gain and frame rate settings at the velocity levels of 15, 20, 35 and 65 cm/s with the beam incident angles of 30 degrees and 60 degrees. The power (P) of received Doppler signal was digitized to 25 gray values (G) for imaging using a wall motion filter with the transfer function: G = a x log P + b (a, b = constant values). Image intensity was measured at the center of the flow image off-line and compared with the flow velocity measured by conventional pulsed wave Doppler. Below the Nyquist limit, G increased as velocity increased, and G with the incident angle 30 degrees was lower than those with 60 degrees. Overall relationship between the Doppler shift frequency and the image intensity exhibited an excellent correlation when fit to the theoretical curve derived from the filter property (r = 0.97). The signal intensity of power Doppler image of flow depends upon the mean Doppler frequency shift or the flow velocity and was clearly affected by the wall motion filter.

Echocardiography, Doppler↗

PubMed1999

Role of radiotherapy for mucoepidermoid carcinoma of salivary gland.

This report analyzes 61 patients with mucoepidermoid carcinomas of the salivary gland treated by surgery alone or by surgery plus radiotherapy. Local control for all 61 patients at 5 and 10 years was achieved for 88.8 and 79.7% of the cases. Although the rate of positive surgical margin was higher in patients treated with surgery and radiotherapy (radiotherapy group) than in patients treated by surgery alone (surgery group), the local control rates of the two groups showed no statistically significant differences. There was no local recurrence in seven patients receiving post-operative radiotherapy above 55 Gy while there were three local relapses among 17 patients receiving 55 Gy or lower doses (P < 0.05). The 5- and 10-year actual survival rates were 73.4 and 63.3% respectively. Histopathologic subtype of mucoepidermoid carcinomas correlated with regional lymph node involvement and survival. There were no differences in the local control and survival rates of patients with major salivary gland tumors and patients with minor salivary gland tumors. Radiotherapy using 55 Gy or more combined with operation achieved local control and survival rates comparable with complete resection of tumors even if a positive surgical margin was more frequent in the radiotherapy groups.

Adolescent↗

PubMed1999

Existence of activated and memory CD4+ T cells in peripheral blood and their skin infiltration in CD8 deficiency.

CD8 deficiency is a rare primary immunodeficiency caused by the defect of a tyrosine kinase, ZAP-70, which transduces signals from the T cell receptor. We report here a case of CD8 deficiency, having CD4+ T cells with a unique phenotype. The patient's T cells did not respond to anti-CD3 stimulation in vitro, suggesting that they were naive. However, many CD4+ T cells with activated and memory phenotypes, which expressed CD45RO+, HLA-DR+ and CD25+, were present in the peripheral blood, and these cells accumulated in the perivascular area of his infiltrative erythematous skin lesions. The patient's T cells could be activated by a high concentration of phytohaemagglutinin (PHA), indicating the presence of an alternate signalling pathway which bypasses ZAP-70 and activates CD4+ T cells in vivo. The origin and role of activated CD4+ T cells in the pathogenesis involved in the skin lesions are discussed.

CD4-Positive T-Lymphocytes↗

PubMed1999

Effect of diacerein on spontaneous polyarthritis in male New Zealand black/KN mice.

OBJECTIVE: Male New Zealand black/KN (NZB/KN) mice spontaneously develop polyarthritis, characterized by destructive damages to the articular cartilage and bone. We assessed effects of diacerein in male NZB/KN mice by radiographic and histopathologic examinations. DESIGN: Diacerein, cyclosporin A or vehicle for the control were orally administered for 7 months, initiating at 8 weeks of age when the arthritis became apparent. RESULTS: At 39 weeks of age, the NZB/KN mice developed polyarthritis in the joints of the forelimbs and hind legs, radiographically characterized by joint space narrowing, deformation of the joint surfaces, and bone erosions. Histopathologic findings showed that the tarsal joints and knee sections from the NZB/KN mice exhibited overt arthritic lesion. Radiographic and histopathologic findings showed that diacerein and cyclosporin A at a dose of 30 mg/kg/day significantly reduced the progression of arthritis. CONCLUSIONS: Diacerein shows articular protecting effects against the development of spontaneous arthritis in male NZB/KN mice and diacerein might be useful in the treatment of chronic inflammatory joint diseases during clinical use.

Animals↗

PubMed1999

Endoscopic correction of pectus excavatum.

Pectus excavatum has been most commonly corrected by either the sternal elevation or turnover methods. Both of these procedures require a long skin incision in the anterior chest wall. Endoscopic techniques have been introduced into the treatment of pectus excavatum since 1994 to minimize the skin incision to approximately 1 inch. Thirty patients with pectus excavatum (25 men and 5 women) underwent surgery employing the centimeter incision method assisted by the endoscope. The mean age at the time of surgery was 11.9 years (range, 4-45 years). The patients were classified as having one of three types of pectus excavatum: Type I (symmetrical and localized) was seen in 18 patients (60%), type II (symmetrical and diffuse) was seen in 5 patients (17%), and type III (localized or diffuse but asymmetrical) was seen in 7 patients (23%). Although the results of the thoracic cage correction achieved using our procedure were excellent overall, the results were best for type I, with clear improvement achieved in the funnel index-0.48 to 0.63. All of the patients recovered well without any severe complications, and both the patients and their families found the results obtained using this method to be quite satisfactory, especially because of the minimal postoperative scar.

Adolescent↗

PubMed1999

Histological examination of regenerated bone through craniofacial bone distraction in clinical studies.

The process of bone formation by distraction osteogenesis of the craniofacial bone has been studied in animals. To our knowledge there are no published findings in which histological examination of craniofacial distraction in humans has been reported. Specimens were obtained from 10 patients who underwent craniofacial distraction: 2 patients who underwent mandibular distraction, 7 patients who underwent midface distraction, and 1 patient who underwent nasal bone distraction. These specimens were examined histologically. The results revealed that 8 of 10 patients exhibited new bone formation. No cartilaginous callus formation was observed in any of the specimens, which strongly suggests that new bone was produced by intramembranous ossification during human craniofacial bone distraction.

Adolescent↗

PubMed1999

Analysis of dural configuration for evaluation of posterior decompression in cervical myelopathy.

OBJECTIVE: The goal of this study was to establish the criteria for sufficient decompression of the cervical spinal cord in laminoplastic surgery. METHODS: Radiological examinations and neurological evaluations were conducted for 63 patients with cervical spondylotic myelopathy (CSM) and 31 patients with ossification of the posterior longitudinal ligament (OPLL) of the cervical spine who underwent suspension laminotomy. RESULTS: The dural configuration in computed tomographic myelograms was evaluated in comparison with the critical value for the dural configuration established from 36 control subjects. Seventy-six of 94 patients were judged to have achieved full decompression. The neurological improvement of patients with full decompression was significantly better than that of patients with insufficient decompression (P<0.01). The postoperative sagittal diameter of the spinal canal was more than 14 mm in most of the sufficiently decompressed cases of CSM and more than 17 mm in OPLL cases. The laminotomy width was more than 70% of the transverse diameter of the spinal canal in both CSM and OPLL cases. There were four OPLL cases with insufficiently decompressed dura mater in the well-enlarged spinal canal after surgery. In these cases, the ossified posterior longitudinal ligament continuously occupied more than 25% of the preoperative spinal canal area over three or more segments. CONCLUSION: The following conditions were considered critical for sufficient decompression of the spinal cord in laminoplastic operations: postoperative sagittal diameter of the spinal canal of more than 14 mm in CSM cases and more than 17 mm in OPLL cases and laminotomy width of more than 70% of the transverse diameter of the spinal canal in both CSM and OPLL cases. However, in cases of extensive OPLL, sufficient decompression could not be obtained through posterior enlargement of the spinal canal.

Adult↗

PubMed1999

Low prevalence of clinicopathologic and sialographic changes in salivary glands of men with Sjögren's syndrome.

Sjögren's syndrome (SS) is uncommon in men and there are few reports that describe their clinical features. In the present study, we investigated salivary gland manifestations in men with SS and compared the results with those in women patients. This study included 12 men and 117 women with SS, and the mean stimulated parotid flow rate in men (4.1 ml/5 min, n = 10) was higher than that of the women (3.1 ml/5 min, n = 101). The prevalence of SS-related sialographic findings, such as globular and punctate sialectasis, was significantly (P<0.05) lower in men (3/11) than in women (72/117). The prevalence of grade 4 cases on labial salivary gland biopsy was also significantly (P<0.01) lower in men (4/11) than in women (82/111). These results indicate a lower prevalence of SS-related clinicopathologic and sialographic changes in men with SS than in women with the same condition.

Arthritis, Rheumatoid↗

PubMed1999

Neurogenic regulation of basal tone of coronary artery with mild atherosclerosis in humans: observation using two-dimensional intravascular ultrasound.

The purpose of this study was to assess the role of the autonomic nervous system in the regulation of basal coronary artery tone in normal and atherosclerotic plaque segments by using intravascular ultrasound in humans. In each of 21 patients, a short-axis image at one site of coronary artery was imaged by means of a 3.2F, 30-MHz intravascular ultrasound before and after intracoronary administration of 2 mg isosorbide dinitrate (ISDN). The authors identified the perimeters of the vessel wall segments with normal or atherosclerotic plaque on ultrasound images and evaluated the basal tone in each segment as a percent increase in each perimeter produced by ISDN. Using heart rate variability analysis for 512 seconds recorded immediately before ISDN administration, they evaluated cardiac sympathetic and vagal activities at rest as the integrated power of fast Fourier transform (FFT) spectrum for the low-frequency (LF: 0.04 to 0.15 Hz), and high-frequency (HF: 0.15 to 0.4 Hz) components, respectively. Of 29 segments examined by ultrasound, 16 were normal and 13 were atherosclerotic plaque. In all 29 segments, ISDN produced an increase in the perimeter of the vessel wall. At the normal 16 segments, the increase in perimeter by ISDN exhibited a significant correlation to the power of HF (r = 0.749, p = 0.0008) but no significant correlation to LF. At 13 plaque segments, however, no significant correlation between the response to ISDN and autonomic nerve activity was observed. In conclusion, the basal tone of normal coronary arterial wall segment is closely related to parasympathetic nerve, whereas the relation is impaired in mild atherosclerotic segments.

Aged↗

PubMed1999

Mucolytic and antitussive effects of erdosteine.

To investigate the influence of erdosteine, a new homocysteine-derived expectorant, on airway clearance we studied the effects of the drug on the viscosity of mucin, on the mucociliary transport rate in quails, on airway secretion in rats and on the cough reflex in guinea-pigs. The active metabolite of erdosteine, M1 (10 microM to 1 mM), significantly reduced the viscosity of porcine stomach mucin. Erdosteine by itself did not reduce viscosity. Erdosteine significantly promoted mucociliary transport in quails and increased airway secretion in rats. The effect was still apparent 24h after administration. Erdosteine significantly suppressed citric acid-induced cough reflexes in guinea-pigs but did not suppress mechanical stimuli-induced cough reflexes. Erdosteine suppressed the reduction of the recovery volume of bronchoalveolar lavage fluid and albumin leakage into the fluid in citric acid-exposed guinea-pigs. These results indicate that erdosteine removes sputum by reducing its viscosity, and by promoting mucociliary transport and sustained enhancement of airway secretion. It also suppressed the chemical stimulation-induced cough reflex and plasma leakage into the airway. These results suggest that erdosteine is an excellent expectorant with several modes of action.

Animals↗

PubMed1999

Effect of 3,6-dimethylpyrazine-2-thiol on androstenedione-induced increase of uterine weight in female rats.

3,6-Dimethylpyrazine-2-thiol administered at 10-70 mg/kg, p.o. was found to suppress androstenedione-induced increase of uterine weight in female rats. This action was weaker than that of aminoglutethimide (3-30 mg/kg, p.o.). After administration of androstenedione, increased plasma estradiol levels were reduced by 3,6-dimethylpyrazine-2-thiol. Moreover, in vitro, production of estradiol in the pregnant mare serum gonadotropin (PMSG)-treated ovary was inhibited by 3,6-dimethylpyrazine-2-thiol. These results suggest that 3,6-dimethylpyrazine-2-thiol has an inhibitory action on aromatase activity.

Aminoglutethimide↗

PubMed1999

Synergistic effect of naphthoquinones on the mutagenicity of nitroarene.

Nitro reduction is a critical step in the mutagenic activation of nitroarene. Nitroarene and quinone are known to be reduced by common enzymes, and thus, naphthoquinone (NQ) was studied for its effects on the mutagenicity of nitroarene in the Ames test using Salmonella typhimurium TA98 without S9. The mutagenicity of 1,3-dinitropyrene in TA98 was found to increase 9- and 6-fold as much in the presence of 70 nmol/plate of 2-methyl-1,4-NQ and 2-hydroxy-1,4-NQ, respectively. Mutagenicity also became greater in 1,3,5-trinitronaphthalene, 1-nitropyrene and 3-nitrofluoranthene. Seventy nmol/plate of 2-methyl-1,4-NQ increased the mutagenicity of 1-nitropyrene by 10.5-fold as much.

Drug Synergism↗

PubMed1999

Histological observations and the process of ultrasound contrast agent enhancement of tissue plasminogen activator thrombolysis with ultrasound exposure.

Although the enhancement of tissue plasminogen activator (tPA) induced thrombolysis by ultrasound has been reported to be augmented by ultrasound contrast agents (UCA), few data exist regarding its process. The present study evaluated the effect of a galactose based UCA on the efficacy of ultrasonic enhancement of tPA thrombolysis and observed the serial changes in the acoustic property and histopathology. A catheter-type transducer capable of ultrasound emission in both continuous (CW) and pulsed wave (PW) was used. The tPA thrombolysis was studied in 30 artificial white thrombi, which were assigned to 4 study groups based on insonation modes and with and without UCA. Each sample was suspended in 100ml saline in a beaker. Five minutes after tPA (8000U) administration, ultrasound was applied for 10min. For the UCA-treated groups, UCA (0.25g) was added 5 min after the start of ultrasound exposure. The alteration of the thrombus was monitored with echography. Weight reduction of the thrombus was -25+/-6% in PW and -30+/-7% in CW, which was significantly enhanced by UCA treatment, 40+/-3% (p<0.005) in PW+UCA and -43+/-7% (p<0.005) in CW+UCA. The area of thrombus echo image minimally decreased with ultrasound alone (-12+/-6%: PW, -23+/-11%: CW). In the UCA groups, UCA induced a remarkable reduction of size (-36+/-3%: PW+UCA, -43+/-7%: CW+UCA) with a high-echo intensity in the superficial layer of the thrombus, where multiple cavity formation was observed by light microscope. UCA markedly enhanced the effect of ultrasound on tPA thrombolysis. The altered acoustic property and corresponding histological microcavity formation in the shallow layer within the thrombus suggests that UCA augmented infiltration of tPA into the thrombus.

Adult↗

PubMed1999

Alteration in aortic wall stiffness and accumulation of collagen during the prediabetic stage of type II diabetes mellitus in rats.

Aortic damage during the prediabetic stage of diabetes mellitus (DM) was investigated in Otsuka Long-Evans Tokushima Fatty (OLETF) rats, as an animal model of type II DM. In 30 OLETF and 30 nonDM rats, an oral glucose tolerance test was performed at 10, 20 and 30 weeks of age. At 15 and 30 weeks, intravascular ultrasound images and aortic pressure were recorded and the stiffness parameter beta was calculated. The aortic walls were excised at 5, 15 and 30 weeks for histopathology and the measurement of hydroxyproline. At 10 weeks, blood glucose (mg/dl) and insulin concentrations (ng/ml) of the OLETF rats (2h; 168+/-30 and 0.82+/-0.15) were significantly high (nonDM: 118+/-15; p = 0.02 and 0.16+/-0.64; p = 0.003). At the prediabetic stage (15 weeks), beta in the OLETF rats (2.5+/-0.9) was larger than in nonDM rats (1.4+/-0.4; p = 0.0006), and the collagen (hydroxyproline) content/dry weight (mg/g) of the aortic wall was significantly higher in OLETF (33.5+/-3.1) than in nonDM rats (28.7+/-3.5; p<.05). Histopathological examination showed that from 15 weeks of age the medial wall thickness increased gradually. In the prediabetic stage, collagen accumulation may contribute to impairment of aortic wall stiffness in the OLETF rats, which would accelerate the aging process in the aortic wall.

Animals↗