Biomedical subjects

M Mukai

Publications and source records attributed to M Mukai.

At least 181 records · Page 10Linked to original sources

PubMed1995

Participation of rhop21 in serum-dependent invasion by rat ascites hepatoma cells.

Rat ascites hepatoma cells (MM1 cells) penetrate through a cultured mesothelial cell monolayer (MCL) in the presence of fetal calf serum (FCS), but scarcely do so in its absence. Inactivation of rhop21 of MM1 cells by ADP-ribosyltransferase C3 resulted in the suppression of this serum effect on the penetration, suggesting that the serum effect was mediated by rhop21. To ascertain this assumption MM1 cells were transfected with an activated (Val14) human rhoA cDNA (Neo/RhoA 1-7). The transfectants penetrated MCL extensively even in the absence of FCS and became largely independent of serum for the penetration. These results suggest that serum-induced invasion by MM1 cells is mainly mediated by rhop21.

ADP Ribose Transferases↗

PubMed1995

Calcineurin activation protects T cells from glucocorticoid-induced apoptosis.

In T cell hybridomas, TCR/CD3 complex-mediated stimulation induces apoptosis but inhibits that induced by glucocorticoids. A combination of ionomycin (IM), a calcium ionophore, and PMA, a protein kinase C activator, mimics the effects of the TCR/CD3-mediated stimulation. Glucocorticoid-induced apoptosis is, however, markedly inhibited by IM alone, and less markedly by PMA alone. The immunosuppressant FK506 canceled the inhibition by IM but not that by PMA. As calcineurin (CN) is one of the target molecules of FK506, we examined whether CN activation might have an anti-apoptotic effect. BOG8, a T cell hybridoma, was stably transfected with a mutant CN catalytic subunit with Ca2+/calmodulin-independent, constitutive but FK506-sensitive phosphatase activity. The transfectant clones were fairly resistant to glucocorticoid-induced death. Their resistance, however, was hardly affected by FK506 when added simultaneously with glucocorticoid, but was lost after a prolonged preincubation with FK506. In the parent BOG8 cells, FK506 failed to cancel the inhibitory effect of IM on glucocorticoid-induced death when the addition of FK506 was delayed for 1 h or more. These results suggest that CN activation is required for the resistance only as an early event. The transfectant clones produced IL-2 but failed to undergo apoptosis upon stimulation with PMA alone, whereas apoptosis was induced by a combination of IM and PMA. These results suggest that activation-induced cell death may require a higher level of CN activity than IL-2 production or may require another Ca(2+)-dependent pathway.

Animals↗

PubMed1995

A pilot study of combination therapy of radiation and local administration of OK-432 for esophageal cancer. Five-year survival and local control rate.

BACKGROUND: Combination therapy consisting of radiation and local administration of OK-432 was administered to 73 patients with esophageal cancer without distant metastases. Seventy patients were examined. The average age was 71 years. There were 60 males and 10 females. The mean tumor length was 7.0 cm. METHODS: One mg of OK-432 was administered endoscopically to and around the cancerous lesion at the beginning of radiotherapy and a second dose of 0.5 mg of OK-432 was given in the same manner 2 weeks later. X-ray irradiation was given at a daily dose of 1.6-1.8 Gy, five fractions a week. The average total dose was 61.1 Gy. RESULTS: Complete responses were obtained in 49 of the 70 patients (70.0%), and partial responses (PR) in the remaining 21. The 5-year cause-specific survival rate of the 70 patients was 33.1%. The 5-year survival rate of the 49 patients with CR was 44.9%, and there were no patients with PR who survived more than 2 years. The 5-year survival rate of the 13 patients with T1 (UICC, 1987) was 79.6%, of the 24 patients with T2/3 41.1%, and of the 33 patients with T4 11.6%. The 5-year survival rates of the 18 patients with tumors less than 5 cm in length and the 40 patients with tumors 5 to 10 cm were 59.9 and 37.9%, respectively. In the patients with tumors more than 10 cm in length, the 4-year survival rate was 14.6%. Sixty-nine of the 70 patients were discharged in good condition and were able to take food orally. CONCLUSIONS: This combination therapy may contribute not only to the survival rate, but also to patients' quality of life.

Aged↗

PubMed1995

K-ras gene mutations in early colorectal cancer ... flat elevated vs polyp-forming cancer....

K-ras gene mutations in early colorectal cancer were detected by two-step sensitive polymerase chain reaction (PCR) and enzyme digestion method. Early colorectal cancer was classified into flat elevated cancer or polyp-forming cancer according to morphology and presence of adenomatous components. A total of 60 paraffin-embedded tissue specimens from patients with early colorectal cancer were analysed. K-ras codon 12 mutations were detected in 23.3% (7/30) of flat elevated cancer and 63.3% (19/30) of polyp-forming cancer. The incidence of K-ras codon 12 mutations in flat elevated cancer was significantly lower than in polyp-forming cancer (P < 0.01). These data suggested that K-ras gene mutations may be correlated with morphology or clinical features in flat elevated cancer, and that flat elevated cancer may originate from a pathway different from adenoma-carcinoma sequence.

Base Sequence↗

PubMed1995

p53 gene mutations in early colorectal carcinoma. De novo vs. adenoma-carcinoma sequence.

p53 gene mutations in early and advanced colorectal cancer were detected by PCR-SSCP analysis. Early colorectal cancer was classified into de novo cancer and polyp-forming cancer, respectively, according to morphology and presence of adenomatous components. A total of 94 paraffin-embedded tissue specimens from patients with colorectal cancer were analysed. p53 gene mutations were detected in 40.0% (12/30) of de novo cancer, 36.7% (11/30) of polyp-forming cancer, and 44% (15/34) of advanced cancer. p53 mutations were detected at a high frequency in both types of early colorectal cancer as well as in advanced cancer. No correlations were found between p53 mutations and clinicopathological data. Our data suggest that the p53 gene mutations occurred in the early colorectal cancer stage of carcinogenesis regardless of the pathway.

Adenoma↗

PubMed1995

Relationship between sandblasting and composite resin-alloy bond strength by a silica coating.

Modification of alloys for resin-bonded fixed partial dentures has been suspect since the introduction of the conservative procedure. This study investigated the effect of sandblasting on composite resin-alloy bond strengths with the Silicoating technique. Ag-Pd and Ni-Cr alloys were prepared for casting. The specimens then were sandblasted with 37 microns or 250 microns Al2O3 particles under the following conditions: 3 kg/cm2 for 30 seconds; 5 kg/cm2 for 10 seconds, 30 seconds, and 45 seconds; and 7 kg/cm2 for 30 seconds. After each sandblasting treatment, the surfaces of the alloys were examined with the scanning electron microscope and the wettability of the alloy surfaces was measured. After sandblasting, the alloy surface was silica-coated, and light-cured composite resin then was bonded to the alloy. Specimens were divided, stored in dry air for 1 week, and thermocycled from 4 degrees to 60 degrees C for 10(4) cycles. Bond strength was measured by applying compressive shear stress. It was found that sandblasting made the alloy-water contact angle smaller and wettability greater. The adhesive strength of composite resins with alloys was influenced by sandblasting.

Aluminum Oxide↗

PubMed1995

Effects of acetazolamide on the sleep apnea syndrome and its therapeutic mechanism.

Twenty male patients with sleep apnea syndrome were treated with acetazolamide (AZM), a carbonic anhydrase inhibitor. In 14 of the patient a significant decrease was found in the number of apnea, apnea index and % apnea time (percentage of time spent with apnea to the total sleep time) with improvement in sleep structure, clinical symptoms, such as insomnia, daytime excessive sleepiness and snoring. A significant decrease was also observed in arterial blood pH and HCO-3 in the 14 improved patients. On the other hand, no improvement occurred in the parameters of sleep apnea and sleep with AZM in the remaining six patients. Moreover, metabolic acidosis and an improvement in arterial blood gases did not occur with AZM in the six patients.

Acetazolamide↗

PubMed1995

Blood pressure response to the Valsalva maneuver in pheochromocytoma and pseudopheochromocytoma.

To elucidate whether a difference in blood pressure reactivity exists between patients with pheochromocytoma (n = 8) and pseudopheochromocytoma (n = 22), we evaluated blood pressure changes during a Valsalva maneuver and baroreceptor reflex sensitivity. We also examined the effects of propranolol and prazosin on blood pressure reactivity during a Valsalva maneuver in patients with pseudopheochromocytoma. Pseudopheochromocytoma was defined as a paroxysmal rise in blood pressure accompanying pheochromocytoma-like symptoms and normal catecholamine values. The difference in systolic blood pressure between phase IV of the Valsalva maneuver and baseline (delta SBP) was markedly smaller in the pheochromocytoma patients (8.4 +/- 18.4 mm Hg) than in the essential hypertension patients (n = 30, 30.9 +/- 19.4 mm Hg) and normotensive control subjects (n = 10, 31.3 +/- 11.4 mm Hg), whereas delta SBP in the pseudopheochromocytoma patients (77.8 +/- 11.2 mm Hg) was markedly greater than in the other three groups. delta SBP was markedly suppressed by the administration of both propranolol and prazosin. Baroreceptor reflex sensitivity index was lower in the pheochromocytoma group than in the other three groups. In conclusion, blood pressure reactivity responses to a Valsalva maneuver are disparate between pheochromocytoma and pseudopheochromocytoma. The high blood pressure reactivity to a Valsalva maneuver in pseudopheochromocytoma is due to hyperactivity in both beta- and alpha 1-adrenergic receptor functions, and the low blood pressure reactivity to a Valsalva maneuver in pheochromocytoma seems to be mainly due to the desensitization of both adrenergic systems associated with chronic catecholamine excess. In addition, the impaired baroreceptor function in pheochromocytoma is partially responsible for it.

Adrenal Gland Neoplasms↗

PubMed1995

Acute effect of glyceryl trinitrate on systolic blood pressure and other hemodynamic variables.

The acute effect of glyceryl trinitrate (GTN) is mainly the reduction of systolic blood pressure (SBP) rather than diastolic blood pressure (DBP). To examine the mechanisms for decrease in SBP by GTN, the authors measured arterial compliance (AC), cardiac output (CO), stroke volume (SV), pulmonary capillary wedge pressure, right ventricular end-diastolic pressure, right atrial pressure, and left ventricular end-diastolic pressure before and after administration of GTN. Fourteen patients who underwent cardiac catheterization were included in this study. The change of each variable was estimated by the differences between values just before and at three minutes after GTN. After administration of GTN, SBP was significantly decreased from 158 +/- 21 to 138 +/- 12 mmHg (P < 0.01). AC was significantly increased, and pulmonary capillary wedge pressure, CO, and SV were significantly decreased. The change in SBP was inversely correlated with the change in AC and positively correlated with the change in CO or SV. The authors conclude that the mechanism for decrease in SBP by GTN is associated with both an increase in AC and a decrease in venous return.

Administration, Sublingual↗

PubMed1995

Mechanism of atrial fibrillation and increased incidence of thromboembolism in patients with hypertrophic cardiomyopathy.

To elucidate the morphologic characteristics of the left ventricle in patients with hypertrophic cardiomyopathy who developed atrial fibrillation, we studied left ventricular geometry by two-dimensional echocardiography in 92 patients with hypertrophic cardiomyopathy. These patients were divided into two groups; 24 patients with transient or persistent atrial fibrillation (group I) and 68 patients with sinus rhythm (group II). Left ventricular chamber size in group I was significantly smaller than that in group II. Left ventricular chamber size was correlated positively with stroke volume, and was correlated negatively with left ventricular end-diastolic pressure. The incidence of systemic thromboembolism in group I was 7.1% per patient year. In hypertrophic cardiomyopathy, the size of the left ventricle appears to have major pathophysiologic significance in the development of atrial fibrillation. In addition, since patients with hypertrophic cardiomyopathy who develop atrial fibrillation have a potential risk of systemic thromboembolism, prophylactic anticoagulant therapy should be performed in these patients.

Adult↗

PubMed1995

[The association of the disease activity of rheumatoid factor positive vasculitis and the level of rheumatoid factor].

Rheumatoid factor (RF), an autoantibody against the Fc portion of denatured IgG, has long been recognized as an important biologic marker not only for rheumatoid arthritis but also for other auto-immune diseases. In this study, we measured the level of serum RF in four patients with RF positive systemic vasculitis using laser nephelometry. Three patients were diagnosed as polyarteritis nodosa and the other patient was diagnosed as systemic vasculitis without the finding of typical necrotizing vasculitis from biopsies. In the result, we found that the level of RF paralleled the disease activity in these cases. When active phase of the disease, the level of RF showed very high, and after the treatment combined with plasmapheresis, corticosteroid and immunosuppressive agent, the level of RF decreased in accordance with CRP, ESR and clinical features. These suggested that RF was the disease specific marker for RF positive vasculitis and beneficial informations for proper diagnosis and better treatment could be provided by measurement of the level of RF in patients with RF positive systemic vasculitis.

Adult↗

PubMed1995

[An 80-year-old female with pneumopericardium due to gastric perforation].

An 80-year-old woman was admitted to our hospital because of chest oppression and general malaise. On admission, auscultation of the heart revealed friction rub, so-called water-wheel like murmur. Chest X-ray film and computed tomography showed cardiomegaly and free air in the pericardium. Electrocardiogram showed low voltage with ST elevation in II, III, aVF and V1-V4. These findings suggested that the patient had pneumopericardium with pericarditis. Wenchebach type A-V block and atrial bradycardia appeared. Thus, the ventricular pacing was performed. However, patient died of multiple organ failure. The postmortempericardiography showed the gastro-pericardial fistula with hiatus hernia.

Aged↗

PubMed1995

[Three cases with systemic rheumatic diseases who developed pulmonary lesions suggestive of bronchiolitis obliterans organizing pneumonia].

Three cases with systemic rheumatic diseases who developed lung diseases compatible with BOOP were reported. Underlying diseases of these patients were: RA (1 case), SLE (2 cases). Respiratory symptoms were observed in one case such as dry cough at the time of diagnosis of BOOP. Chest radiography showed multiple infiltrates in 2 cases, bilateral reticular shadow in one case. In one case characteristic finding described as wandering shadow was observed. TBLB was done in 3 cases. Pathohistological findings were compatible with BOOP. Repeated Bacteriological examinations failed to demonstrate specific organisms implicated for lung lesions. Cytological studies of sputum and TBLB specimens were all negative for malignancy. Antibiotic agents including anti-tuberculosis drugs were not effective for pulmonary diseases. Moderate doses of prednisolone were effective in 3 cases. Although the open lung biopsy has been recommended for establishment of diagnosis of BOOP, in patient with systemic rheumatic diseases this invasive procedure is not always easily performed. Further characterizations of clinical and laboratory features are indicated for noninvasive diagnosis of BOOP.

Adult↗

PubMed1995

[A case of pulmonary fibroma].

A 42-year-old man without symptoms was admitted to the hospital because of a well-circumscribed mass in his left upper lung field, which was found on a routine chest X-ray film. CT of the chest revealed a well-defined homogeneous mass in the left upper lobe. Bronchial biopsy yielded material unsatisfactory for diagnosis. On thoracotomy a tumor, entirely within the lung parenchyma, was found to occupy S3. Due to its size and location left upper lobectomy was done. Histologically, the tumor contained interlacing bundles of spindle cells compatible with fibroma, with no indicators of malignancy. Intrapulmonary fibromas are rare and only one report could be found in the Japanese literature.

Adult↗

PubMed1995

Clinical evidence for an association between left ventricular geometric adaptation and extracardiac target organ damage in essential hypertension.

OBJECTIVES: To elucidate an association between left ventricular geometric adaptation to sustained hypertension and preclinical extracardiac target organ damage in essential hypertension. We also studied the clinical significance of neurohumoral factors for cardiovascular structural changes. DESIGN: One hundred and forty patients with essential hypertension were divided into four subgroups, based on left ventricular mass index and relative wall thickness. With respect to extracardiac target organ damage, we measured the funduscopic grade of retinal changes and serum creatinine levels. RESULTS: Among the hypertensive patients, only 19 (14%) had a typical concentric hypertrophy (increase in left ventricular mass index and relative wall thickness). Hypertensive patients with concentric hypertrophy had the most advanced funduscopic abnormalities and the greatest renal involvement, and hypertensive patients without left ventricular hypertrophy had the least extracardiac target organ damage. Plasma renin activity and plasma aldosterone concentration were higher in hypertensive patients with than in those without concentric hypertrophy. In a multiple regression model there was a strongly significant correlation between the degree of left ventricular mass index and the severity of hypertensive retinopathy and renal involvement, independent of office blood pressure. CONCLUSIONS: These results clearly demonstrate that echocardiographically determined left ventricular mass and geometry stratify extracardiac target organ damage in patients with essential hypertension more closely than office blood pressure. The present study also suggests that, in addition to blood pressure load, the renin-angiotensin-aldosterone system appears to play an important role in myocardial hypertrophy and peripheral vascular damage in hypertension.

Aldosterone↗

PubMed1995

Effect of age on left ventricular geometric patterns in hypertensive patients.

OBJECTIVES: To investigate the effect of age on left ventricular structure and geometry in hypertensive patients, we studied the relationship between age and echocardiographic variables in patients with uncomplicated essential hypertension. PATIENTS AND METHODS: We divided 168 patients with hypertension into three groups according to age: young (<40 years), middle-aged (40-59 years) and an elderly group (> or = 60 years). They were further categorized according to relative wall thickness and the left ventricular mass index. We then evaluated the prevalence of left ventricular geometric patterns in these patients according to age. RESULTS: The left ventricular end-diastolic dimension decreased with age, both in normotensive control subjects and in hypertensive patients. The magnitude of this decrease was similar for both. The relative wall thickness and left ventricular mass index were greater in the hypertensive patients than in the normotensive control subjects, and these increased with age both in the controls and the hypertensives. The differences between normotensives and hypertensives in these variables remained unchanged with age. The prevalence of a normal left ventricle (normal relative wall thickness and left ventricular mass index) in the hypertensive patients decreased with age. Conversely, the prevalence of concentric remodeling (increased relative wall thickness with normal left ventricular mass index) and concentric hypertrophy (increased relative wall thickness and left ventricular mass index) increased with age. CONCLUSIONS: These results demonstrate that age significantly affects left ventricular structure both in normotensive control subjects and in hypertensive patients. Thus, the differences in left ventricular geometric patterns with age may have important implications in assessing left ventricular structure and geometric patterns in hypertensive patients.

Adult↗

PubMed1994

Magnesium distribution in human bone.

The present study was undertaken to reveal the magnesium distribution in human bone. Sixty human ribs, obtained from subjects aged 10-80 years of age, were used. Transverse sections were prepared from the middle region of the human ribs. Adjacent sections were ground to a thickness of about 1000 microns. One section was used for magnesium determination by atomic absorption spectrophotometry, and the other was used for analysis with X-ray microanalysis. Thirty micron thick samples were abraded continuously from the periosteal and the endosteal surfaces by abrasive microsampling, as previously described by Weatherell et al. Results showed that magnesium concentrations were higher in both the periosteal and endosteal surfaces and did not change with age in general, although it tended to be higher among teenagers and lower over 80 years old.

Adolescent↗

PubMed1994

Fluoride distribution in dentine and cementum in human permanent teeth with vital and non-vital pulps.

Twenty-two selected permanent teeth [11 with vital pulps and 11 with non-vital (necrotic) pulps] were obtained from patients aged from 20 to 73 yr in Nagoya, Japan. Fluoride (F) profiles in tooth samples were examined by using an abrasive micro-sampling technique. F levels in the pulpal dentine were significantly higher in vital than non-vital teeth for each age group, although there were observed increases of F with age. In the cementum the F levels were strongly related to age and there were few differences in profiles and levels of F between vital and non-vital teeth. It was concluded that vital pulp is an important factor for the pulpal dentine to absorb fluoride.

Adult↗