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Biomedical subjects

M Okamoto

Publications and source records attributed to M Okamoto.

At least 343 records · Page 19Linked to original sources
PubMed1998

Incidence of Prevotella intermedia and Prevotella nigrescens in periodontal health and disease.

The incidence of black-pigmented rods (BPRs), especially Prevotella intermedia and Prevotella nigrescens, in periodontal health and disease were examined. Furthermore, the degradative enzyme activities of P. intermedia were compared among the strains from periodontal health and disease. Microbiological specimens were collected from subgingival crevice or periodontal pocket by paper point. The BPRs were found in 71.1% of periodontally healthy subjects (n=45), and in 47.1% of healthy sites (n=34) and 87.8% of active sites (n=41) among periodontally diseased patients. Porphyromonas gingivalis was detected only in active sites of periodontally diseased patients (17.8% of 180 strains). P. intermedia was the predominant BPR in both healthy and active sites (37.3 and 41.7%, respectively) of the patients. However, P. nigrescens was the predominant BPR (70.5% of 173 strains) in periodontally healthy subjects. The enzyme activities of esterase, esterase-lipase, acid-phosphatase and alpha-fucosidase of P. intermedia strains isolated from active sites in patients were significantly higher (P<0.05) than those of healthy subjects. The results suggest that P. intermedia might increase the activity of degradative enzymes under a certain condition and support the progression of periodontitis.

Adult↗
PubMed1998

Results of transurethral resection plus adjuvant intravesical chemotherapy for superficial bladder cancer.

BACKGROUND: We analyzed the results of conservative therapy for superficial bladder cancer to determine the risk factors for recurrence and progression. METHODS: Between May 1984 and February 1997, 111 patients with primary superficial bladder cancer were treated by a transurethral resection with or without intravesical instillation of chemotherapy, or for patients with concomitant carcinoma in situ (CIS), bacillus Calmette-Guérin. We examined the relationship between tumor stage, grade, incidence of concomitant CIS and recurrence-free survival according to pathologic findings and the drugs instilled. RESULTS: The incidence of concomitant CIS in pT1, grade 3 tumors was significantly higher than that in pTa, grade 1 tumors (42% vs. 3%, P= 0.006). The 5-year recurrence-free survival rate of all patients was 73%. There was no significant difference in recurrence-free survival and pathologic stage, tumor grade, presence of concomitant CIS, or drugs used for instillation. However, the recurrence-free survival in patients with > or = 5 tumors was significantly lower than in patients with less than 5 tumors. Of the 111 patients, only 3 patients demonstrated disease progression and underwent a radical cystectomy, while 1 patient with a pT1b, grade 3 tumor developed a tumor in the ureter. No patient died of bladder cancer. CONCLUSION: Our results indicate that the prognosis of superficial bladder cancer patients with a high-stage, high-grade (pT1, grade 3) tumor is favorable when treated by a transurethral resection and intravesical instillation. Bacillus Calmette-Guérin therapy is useful to prevent the recurrence of tumors with concomitant CIS.

Administration, Intravesical↗
PubMed1998

Relation between radiographic mottle for double and single emulsions.

The radiographic density fluctuations produced by using dual screen-film systems are designated as the radiographic mottle. The density fluctuation of the radiographic mottle for the double emulsions at a density of the double emulsions consists of those for the front and back emulsions on a radiograph. However, the relation between the Wiener spectra of the radiographic mottle for the double and single emulsions had not been studied. Hence we compared the Wiener spectra of the radiographic mottle for the double emulsions with the sum of those for the front and back emulsions on the same radiographs and with the sum of those for the emulsions at the same densities. At all densities of more than 0.62 for lower spatial frequencies (< or = 1 mm-1), the Wiener spectral values of the radiographic mottle for the double emulsions were greater than the sum of those for the front and back emulsions for both comparisons on the same radiographs and at the same densities. In order to investigate the reason of the above phenomena, we separated the Wiener spectral values of the radiographic mottle for various densities into those of the three factors, i.e., quantum mottle, structure mottle, and film granularity, and performed the same comparisons as the radiographic mottle. Also, to explain the results for the three factors, we obtained the Wiener spectral values of the spatial fluctuations of the light exposure or the fluorescence intensity and the gradients of the characteristic curves of the film for the double and single emulsions of the x-ray film. As a result of the investigation, we found that the phenomena on the radiographic mottle were caused by that (1) on the same radiographs the squares of the gradients of the characteristic curves for the double emulsions were about 5.3 times as great as those for the single emulsion at densities of more than 0.62 of the double emulsions, and (2) at the same density of more than 0.62 those were more than about 2.2 times as great as those for the single emulsion.

Biophysical Phenomena↗
PubMed1998

Cloning of a membrane-spanning protein with epidermal growth factor-like repeat motifs from adrenal glomerulosa cells.

The three zones of adrenal cortex are thought to arise from a single multipotential stem cell, but the mechanisms underlying the zonal differentiation during embryonic development of adrenal cortex are poorly understood. Employing subtraction cloning strategy, we isolated three distinct clones that were specifically expressed in the rat glomerulosa zone. One clone, named zona glomerulosa specific clone, encoded a membrane-spanning protein with a signal peptide at the N-terminus, six epidermal growth factor-like repeat motifs, and a transmembrane domain near the C-terminus. It was identified as a rat homolog of preadipocyte factor-1 (Pref-1), a factor involved in maintaining the undifferentiated status of preadipocyte. Immunohistochemical studies confirmed the presence of Pref-1 protein in the glomerulosa zone. Detailed examination revealed that the zone is divided into two layers; the first is a few-cells-thick layer present underneath the capsule (expressing both Pref-1 protein and aldosterone synthase cytochrome P450), and the second layer is beneath the first (containing Pref-1 protein but not aldosterone synthase). Moreover, another cell layer was found beneath the second layer and above the fasciculata zone, whose cells contained no Pref-1 protein, aldosterone synthase, or 11beta-hydroxylase. These findings suggest that a recently reported aldosterone synthase- and 11beta-hydroxylase-less cell layer between the two zones is composed of two kinds of cell: Pref-1 protein-positive and -negative cells. The level of Pref-1 message in the adrenal glands of animals having various pituitary-adrenal axis activities, as well as various plasma salt concentrations, correlated with the total number of glomerulosa cells. However, the specific content of Pref-1 message in a cell was fairly constant. When the adrenal gland was surgically enucleated and the remaining capsule regenerated, the level of Pref-1 transcript was significantly suppressed at the early phase. At this phase, only a minor population of the cortical cells expressed Pref-1 protein, most of these cells already expressing a fasciculata/reticularis-specific marker, inner zone antigen. These findings suggest that the capsular cells, mostly composed of the glomerulosa cells, may have potential for differentiating into other zones' cells, and the down-regulation of Pref-1 expression may be an important step in the adrenal zonal differentiation.

Adrenal Glands↗
PubMed1998

CytA protein, a delta-endotoxin of Bacillus thuringiensis subsp. israelensis is associated with DNA.

CytA protein (27 kDa) is produced by Bacillus thuringiensis subsp. israelensis (BTI) and is contained in its inclusion bodies. We previously reported the isolation of 25 kDa portion of CytA protein (p25-CytA protein) and its strong cytotoxic activity to mammalian cells. When p25-CytA protein was applied to an anion-exchange column for further purification, three fractions (M1, M2 and M3) were separated. M1 and M2 fractions were both shown to be 25 kDa protein, while M3 was a high molecular weight complex composed of 25 kDa protein and DNA. Purification and amino acid sequence analysis showed that M1 and M2 fractions were proteins lacking 29 and 31 N-terminal amino acids from CytA protein, respectively, and M3 was M1 protein associated with DNA. DNA was detected in BTI cells co-localizing with inclusion bodies. Both M1 and M2 proteins could bind to double-stranded DNA of BTI genome in vitro; the DNA binding ability of M1 protein was higher than that of M2 protein. These results suggested that CytA protein has DNA binding ability and is associated with DNA in the mother cell.

Amino Acid Sequence↗
PubMed1998

Time-dependent changes in the ischemic forebrain following the microsphere-induced permanent occlusion of cerebral arterioles in rats.

To evaluate the progression of brain edema without modification by the effect of anesthetics, we examined the local and permanent ischemia model in unanesthetized rats. The forebrain embolism was induced by intra-arterial infusion of microspheres of 50-microm diameter in freely moving rats. From 2 to 48 hr following the injection, the water-, Na- and Ca-contents progressively increased while the K content decreased in the microsphere-injected hemisphere. After the 3rd day, the water- and Na-contents gradually decreased and returned to the normal level on the 14th day. In contrast, the Ca level remained elevated even on the 56th day. The animals showed signs of neurological deficits 24 hr after the injection. In histopathological examination, large infarct areas were present in the microsphere-injected hemisphere after 24 to 48 hr. One to two weeks later, the lateral ventricle was expanded. Eight weeks after the injection, the ventricle remained expanded and newly developed infarct areas were observed in a scattered pattern around the fibrotic area. The results show the close correlation between the development of edema and the increase/decrease of Na/K contents from the onset to the recovery from edema, and their changes are similar to those in human stroke. This model enables us to evaluate not only the acute ischemic insult but also the chronic changes of the forebrain following the stroke.

Animals↗
PubMed1998

[Toxicity study of sodium N-[2-[4-(2,2-dimethylpropionyloxy) phenylsulfonylamino] benzoyl] aminoacetate tetrahydrate (ONO-5046.Na) (5). 6-month repeated dose intravenous toxicity study in dogs with 1-month recovery test].

A 6-month repeated dose toxicity study with 1-month recovery test of sodium N-[2-[4-(2,2-dimethylpropionyloxy) phenylsulfonylamino] benzoyl] aminoacetate tetrahydrate (ONO-5046.Na), a novel neutrophil elastase inhibitor, was conducted in beagle dogs. The dogs of both sexes were administered ONO-5046.Na intravenously at a daily dose of 0 (vehicle control), 7.5, 15 or 30 mg/kg. In the 15 mg/kg and above groups, transient ataxic gait was observed. It is considered that this symptom could be attributed to the pharmacological effect of ONO-5046.Na. Macro- and microscopic hemorrhage at the injection site was observed in the ONO-5046.Na treated groups. However, it is considered that these findings could be attributed to the long-term repeated dosing procedure, and were not toxic changes. There were no treatment-related changes in body weight, food consumption, ophthalmology, urinalysis, hematology, blood chemistry, electrocardiography and organ weights. These results indicate that the NOAEL of ONO-5046.Na in dogs is 30 mg/kg/day for both sexes in this study.

Animals↗
PubMed1998

Clinical manifestations due to a point mutation of the mitochondrial tRNAleu(UUR) gene in five families with diabetes mellitus.

It has been shown that an adenine (A) to guanine (G) transition at position 3243 of the mitochondrial transfer RNA(tRNA)leu(UUR) gene is associated with a subgroup of diabetes mellitus. Therefore, we screened for this transition in 86 patients with non-insulin-dependent diabetes mellitus (NIDDM) in which two or three generations were affected with diabetes, in 14 patients with insulin-dependent diabetes mellitus, and in 9 families with diabetes mellitus and/or associated disorders suggesting mitochondrial gene abnormalities. We failed to identify the mutation in 100 diabetic patients, 86 NIDDM and 14 insulin-dependent diabetes mellitus (IDDM). Out of the latter 9 families, we identified an A to G transition in 14 individuals in 5 families. Diabetes mellitus was shown to be maternally inherited in one family. In 9 of 14 patients with the mutation, insulin was required to treat diabetes mellitus, indicating impaired insulin secretion. A hyperglycemic clamp test performed in one subject revealed significant impairment of insulin secretion, whereas euglycemic clamp test showed normal insulin sensitivity in this patient. The heteroplasmy of the mutant mitochondrial DNA (mtDNA) in leukocytes does not appear to correlate with the severity of diabetes in terms of the insulin therapy required. Body mass index of the affected individuals was less than 23.3. In one family, in addition to diabetes mellitus and hearing loss, hypoparathyroidism was associated with the mutation, suggesting that hypoparathyroidism is caused by the impaired processing and/or secretion of proparathyroid hormone due to the mutation. In addition, the affected subjects presented with proteinuria at the time of diagnosis of diabetes mellitus which appeared not to be related with diabetic nephropathy.

Adolescent↗
PubMed1998

Collateral flow detected by a Doppler guide wire in a case of vasospastic angina.

We could detect recruitable backward collateral flow in systole and diastole by using a Doppler guide wire during coronary artery spasm in a 42-year-old female among 20 patients with documented variant angina. The electrocardiogram (ECG) showed no ST-segment deviation, although she had chest pain and her coronary angiography showed a totally occluded right coronary artery. After administration of isosorbide dinitrate (ISDN) the collateral flow disappeared and the flow pattern recovered to normal. The good collateral flow pattern in patient with totally occluded coronary artery due to spasm was indicated to relieve myocardial ischemia, even when the patient felt chest pain.

Adult↗
PubMed1998

Preventive effect of ACE inhibitor on interstitial myofibroblast formation and matrix deposition in a nephrotic model.

The nephrotic mouse (ICGN strain) is a useful model for progressive nephrotic syndrome (NS). In the present study, we demonstrated the preventive effects of enalapril, an angiotensin converting enzyme (ACE) inhibitor, on the progression of renal dysfunction and tubulo-interstitial fibrosis in the NS mice. Administration of enalapril (5 mg/dL in drinking water) to the 4-week-old NS mice for a 4-week-period did not improve their nephrotic symptoms such as albuminuria and hypoalbuminemia, but significantly suppressed the increases in blood urea nitrogen and serum creatinine levels. Renal histopathology demonstrated that the administration of the ACE inhibitor significantly attenuated the progression of the tubular and interstitial lesions (tubular dilatation, luminal cast accumulation and interstitial expansion) rather than the glomerular sclerotic changes. The suppression of the increase in blood urea nitrogen level by enalapril depended on the attenuated tubular injury rather than on the unchanged glomerular matrix deposition. Immunohistochemical examination revealed that the administration of the ACE inhibitor suppressed the formation of myofibroblasts, identified by the alpha-smooth muscle actin-positive cells, in the interstitial spaces. Consequently, interstitial matrix deposition was significantly reduced in the NS mice treated with enalapril. From the results obtained with the spontaneous nephrotic model, we emphasize a possibility that ACE inhibitor may be effective for attenuating progression of renal dysfunction and fibrosis in human NS, even if the ACE inhibitor fails to improve nephrotic symptoms such as albuminuria and hypoalbuminemia.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed1998

Computerized tomography angiography of ruptured cerebral aneurysms: factors affecting time to maximum contrast concentration.

OBJECT: This study was conducted to assess the diagnostic value of three-dimensional computerized tomography (3-D CT) angiography in demonstrating cerebral aneurysms in 42 consecutive patients presenting with acute subarachnoid hemorrhage (SAH). METHODS: To obtain the volume data for selective visualization of the cerebral arteries without enhancement of the venous system, the time delay was established between the injection of contrast medium and the start of scanning by using two different methods. The circulation time was calculated with Schad's formula in the first 13 cases, but the results were not satisfactory. In the 29 subsequent cases the time delay was established using a single-level dynamic CT prescan. The dynamic prescan demonstrated the statistical differences in peak time with regard to patient age, SAH grade, and the postresuscitation state after cardiopulmonary arrest. The 3-D CT angiograms were generated from the volume data by using a voxel transmission method. Computerized tomography angiography obtained after optimally adjusted time delay demonstrated the contour of the cerebral arteries in 97% of cases, and aneurysms were detected in 93%. Enhancement of the cavernous sinus and major cortical veins was avoided. Even in patients who suffered cardiopulmonary arrest, images of the major arteries were clearly demonstrated after resuscitation. CONCLUSIONS: In an emergency situation, CT angiography with a dynamic prescan may be an alternative to magnetic resonance angiography or digital subtraction angiography in the diagnosis of ruptured aneurysms. This modality would also be useful for the precise assessment of small aneurysms, blebs, and aneurysms adjacent to the cavernous sinus.

Adult↗
PubMed1998

[The reaction of the nasal mucosa in allergic rhinitis to cold saline stimulus].

To clarify the nature of the reaction pattern of the nasal mucosa in allergic rhinitis, nasal lavage using a cold saline solution of 4 degrees C and a warm saline solution was attempted in 8 patients with nasal allergy to the pollen of the Japanese cedar and cypress in a non-scatter season, and the concentration of protein contents in the nasal washings was determined. The concentrations of total protein, albumin and 26 kD protein were higher in cold saline than in the warm saline lavage. In particular, the concentration of 26 kD protein was 5.3 times higher. However, the concentration was not very high compared with the value obtained by warm saline lavage in the scatter season. These findings indicate that the nasal mucosa of patients with allergic rhinitis is reactive to cold saline stimuli even in the non-scatter season.

Adult↗
PubMed1998

[Hearing recovery in sudden deafness with profound hearing loss].

We investigated the hearing recovery in 51 patients with sudden deafness with the initial averaged five-frequency hearing levels worse than or equal to 100 dB. Twenty-two patients were treated in an outpatient setting with a peri-oral steroid, vasodilator, metabolic activator, and vitamin B. The remaining 29 patients were treated in the hospital with additional hyperbaric oxygenation therapy and/or Satellite ganglion block. The results were as follows. 1) The ultimate averaged five-frequency hearing levels were mainly distributed from 55 to 80 dB. Only seven patients showed ultimate hearing levels worse than 100 dB. Two patients achieved complete recovery better than 20 dB. 2) There was no significant difference in the hearing recovery between the patients treated in an outpatient setting and in the hospital. 3) The time interval until the hearing recovery began was distributed broadly between 2 and 28 days from the onset. While most of the patients who began to recover within 14 days from the onset showed ultimate hearing levels better than 80 dB, the patients who recovered after 14 days had worse hearing levels.

Adolescent↗
PubMed1998

[Clinical and histopathological features of hemangiopericytoma-like tumor of the nasal cavity].

A 65-year-old woman consulted our hospital complaining of left nasal obstruction. On nasal examination, a reddish half round tumor arising from the left nasal septum was found. We removed the tumor together with normal septal mucosa. Histologically, the tumor was diagnosed as a hemangiopericytoma-like tumor. It has been reported that a hemangiopericytoma-like tumor is microscopically distinguished from similar type tumors arising from other sites of the body. The most notable microscopic features of intranasal hemangiopericytoma-like tumors are their uniformity of cells and the absence of nuclear or cytoplasmic pleomorphism with a sheetlike arrangement, and no evidence of varying growth phases or necrosis. This is the second case report of this type of tumor in Japan.

Aged↗
PubMed1998

Short report: An imported case of cystic echinococcosis in Japan diagnosed by imaging and serology with confirmation of Echinococcus granulosus-specific DNA sequences.

We report one case of cystic echinococcosis (CE) in Japan in a native of Nepal. Ultrasonography and computed tomography scan of the liver revealed unique cystic lesions with or without daughter cysts of Echinococcus granulosus. Immunoblot analysis using crude antigens of E. multilocularis and cyst fluid of E. granulosus, without reference to these image analyses, strongly suggested this was a case of CE. We found protoscoleces in surgically removed hepatic lesions and analyzed the mitochondrial cytochrome c oxidase subunit I (COI) gene by the polymerase chain reaction. Based on the similarity in DNA sequences of the COI gene of this Echinococcus spp. with that of previously reported sheep-dog strain (GI), the parasite was considered to be the so-called common sheep strain of E. granulosus.

Adult↗
PubMed1998

WA8242A1, A2 and B, novel secretary phospholipase A2 inhibitors produced by Streptomyces violaceusniger. III. Structure elucidation and total synthesis of WA8242B.

The structure of WA8242B, a potent novel inhibitor against phospholipase A2, was fully characterized by spectroscopic methods and chemical degradation. The success of total synthesis of WA8242B confirmed the structure and allowed the pharmacological study of WA8242B. The structures of WA8242A1 and A2 were also described.

Adipates↗