Biomedical subjects

F Ozaki

Publications and source records attributed to F Ozaki.

At least 37 records · Page 2Linked to original sources

PubMed1995

[A morphological study of interactions of Candida albicans and Streptococcus mutans].

Denture stomatitis is caused mainly by infection of Candida albicans and Streptococcus mutans, the most predominant members of the bacterial flora on denture surfaces. The purpose of this study was to investigate the adhesion in vitro of C. albicans and of S. mutans to acrylic surfaces and their interactions. Concentrations of C. albicans and of S. mutans (mutational phase I and III in which activities of glucosyltransferases are higher and lower respectively) were of high levels (> or = 5.0 x 107 colony-forming-units per ml; CFU/ml). The colonies in brain-heart-infusion (BHI) broth added 5% sucrose incubated at 37 degrees C for 18 and 72 hours. Then the samples were dried and evaporated, and examined by S-700 and S-4100 SEM (HITACHI). It was found that S. mutans (mutational phase I) synthesized water-insoluble glucans concomitantly with the adhesion of both S. mutans and C. albicans to the acrylic surfaces. Also, adhesion of C. albicans, mediated by cell-to-cell interactions with S. mutans (especially mutational phase III), to the surfaces was observed.

Acrylic Resins↗

PubMed1995

[The effect on higher cortical dysfunction of percutaneous transluminal angioplasty for internal carotid artery stenosis].

Seven patients with internal carotid artery (ICA) stenosis with higher cortical dysfunction due to hemodynamic ischemia were treated by percutaneous transluminal angioplasty (PTA). The patients ranged from 49 to 71 years of age, and included five males and two females. Neuropsychological tests were evaluated before and after PTA. Higher cortical dysfunction improved in all cases after PTA. It is concluded that PTA is effective to improve higher cortical dysfunction in patients who have ICA stenosis associated with hemodynamic compromise, if the ICA is satisfactorily dilated.

Aged↗

PubMed1995

[A case of spinal dural arteriovenous fistula associated with normal pressure hydrocephalus].

A 62-year-old male presented with urinary incontinence, gait disturbance and dementia for 6 months. Neurological examination revealed severe paraparesis (1/5), sensory disturbance below Th10, neurogenic bladder and absence of patellar and achilles tendon reflexes. CT scan showed mild brain atrophy and symmetric ventriculomegaly with periventricular lucency. Magnetic resonance imaging (MRI) showed a linear flow void lesion on the dorsal surface on the back of his swollen lower spinal cord. Myelography showed a filling defect and flow disturbance of contrast medium in lower thoracic levels, suggesting the presence of adhesive arachnoiditis. Spinal angiography demonstrated a fistula formation between dural branches of bilateral L4 lumbar arteries and ventral spinal and radicular veins on the surface of the dura mater of L4/5 levels. Considering his past history of repeated lumbar puncture for tuberculous meningitis at the age of 22 years, a diagnosis of acquired spinal dural arteriovenous fistula probably due to repeated lumbar puncture was made. Fistulas were embolized with N-butyl cyanoacrylate. And normal pressure hydrocephalus was treated by ventriculoperitoneal shunt. Follow-up CT scans showed a decrease of the size of the ventricular system. Etiology of acquired spinal arteriovenous fistula has been reported. In the case, repeated lumbar puncture may be a possible cause of arteriovenous fistula in the lower spinal dura mater. However, the reason why it took so long to form a fistula after the lumbar puncture remains to be elucidated. We suggest that an increased protein concentration due to disturbance of cerebrospinal fluid flow might be a cause of normal pressure hydrocephalus (NPH).

Arteriovenous Fistula↗

PubMed1995

[Effects on cognitive function and activities of daily living after stereotactic thalamotomy for Parkinson's disease].

Stereotactic thalamotomy was performed in ten patients with Parkinson's disease for the suppression of their tremor. After VL-thalamotomy, contralateral tremor and rigidity disappeared or was significantly reduced. Activities of daily living (ADL) measured by functional independence measure and Parkinson's disability score were improved postoperatively in all patients. There was significant improvement in anxiety index. However, other neuropsychological tests showed no significant change postoperatively. ADL improved after thalamotomy. It is concluded that stereotactic VL-thalamotomy is a useful treatment which improves ADL without cognitive dysfunction.

Activities of Daily Living↗

PubMed1994

[Transcortical sensory aphasia in a patient with metastatic brain tumor in the left frontal lobe].

We reported a case of a 62-year-old right-handed woman who had transcortical sensory aphasia caused by a metastatic brain tumor in the left frontal lobe. She had mild right hemiparesis involving the face, without hyperactive tendon reflexes. She had neither sensory disturbance nor other cranial nerve deficits. Her spontaneous speech was fluent, and she sometimes had echolalia. Her object naming, word fluency, verbal comprehension and writing were severely disturbed. This contrasted with full preservation of repetition of phonemes and short sentences. Reading of words was preserved. CT scan revealed a subcortical lesion in the left superior frontal gyrus. Gd-enhanced MRI showed a ring-enhanced mass lesion in the frontal lobe outside of Broca's area. We thereby concluded that transcortical sensory aphasia may be caused by frontal lobe lesion independent of the perisylvian speech areas.

Adenocarcinoma, Papillary↗

PubMed1992

Synthesis and cardiovascular activity of phenylalkylamine derivatives. I. Potential specific bradycardic agents.

A series of acyclic amide derivatives of N-(omega-aminoalkyl)-N-methylhomoveratrylamine was synthesized and evaluated for their bradycardic activity in isolated guinea pig right atria. Among these compounds, (E)-N-[3-[N'-[2-(3,4-dimethoxyphenyl)ethyl]-N'-methylamino]propyl]- 4-[3,4-(methylenedioxy)phenyl]-3-butenamide (35) was the most potent in vitro and was also found to show dose-dependent bradycardia without remarkable reduction of left ventricular dp/dtmax or mean aortic pressure in anesthetized dogs.

Animals↗

PubMed1992

[Studies on caries of Ishibashi rat--III. Experimental caries in Ishibashi rat].

Dental caries was experimentally induced in the Ishibashi rats (ISR) by feeding them with conventional diets or with caries-producing diets, and the pattern and severity of their induced carious lesions were compared with those of the Sprague-Dawley rats (SD). Simultaneously, serum antibody titers against Streptococcus mutans and calcium and phosphorus concentration in the sera and in the femurs were compared between the ISR and SD. The results were as follows: 1. When judged by cavities, ISR showed a higher carious incidence and average number of cavities per one rat than the SD, whichever diet the rats were fed. 2. When judged by fissure caries observed on the thin sections of the teeth, both the carious incidence and average number of fissure lesions in the ISR were not always high compared with those in the SD, and there seemed to be a great variation of caries-susceptibility in the ISR. 3. Caries in the ISR seemed to be more progressive than that in the SD. 4. There were no differences in the serum antibody titers against the S. mutans between the ISR and SD. 5. No differences in the concentration of calcium and phosphorus in the sera and femurs were observed between the ISR and SD, whichever diet they were fed.

Animals↗

PubMed1991

[Studies on caries of Ishibashi rat--I. Dental caries in Ishibashi rat].

Ishibashi rats (ISR), which have been demonstrated to be excellent experimental animals for congenital vertebral anomaly, are often observed to develop extensive dental caries even when maintained with the conventional diets instead of any caries-producing diets. In this study, dental caries produced in the ISR fed the conventional diets, commercial pellets, was examined and the location and severity of the lesions were compared with those of the albino rats fed the same diet. The results were as follows: 1. Although no caries was detected up to 100 days of age, 70-100% of the ISR of 101 days and over in age had carious teeth. In the albino rats, only 7-30% had carious teeth. 2. The severity of the carious lesions was much greater in the ISR than in the albino rats. 3. Only the mandibular molars were attacked by the dental caries, and the lesions occurred most frequently in the second fissure of the second mandibular molar both in the ISR and the albino rats. Extensive destruction of the crowns of the ISR second mandibular molars were observed in some specimens, but such destruction was not observed in the specimens of the albino rats. These results suggested that the ISR were susceptible to dental caries, and the development of the dental lesions of the ISR seemed to be rapid compared with that of the albino rats.

Animals↗

PubMed1991

[Studies on caries of Ishibashi rat--II. Streptococcus mutans population in oral cavity].

Previously, it was demonstrated that extensive carious lesions occurred in the Ishibashi rats (ISR) while they were bred with conventional diets. In this study, specimens from the oral cavity of the ISR were examined for the presence of Streptococcus mutans, and its occurrence and population were compared with those of the Wistar rats. The results were as follows: 1. S. mutans was first found in the mouth of the ISR when the first molars erupt. 2. The number of S. mutans (CFU on the gelatin agar) and its mean percentage of the total streptococci (CFU on the gelatin agar/CFU on the M-S agar) in the mouth of the ISR increased rapidly during the few days after weaning, and this increment was comparable to that of the Wistar rats fed caries-producing diets, 6PMV, after weaning. However, the population of the S. mutans remained low in the mouth of the Wistar rats fed conventional diets. 3. In the aged ISR, the number of S. mutans and its mean percentage of total streptococci were also much higher than in the aged Wistar rats. These data suggested that the ISR harboured increased the number of S. mutans strains in the oral cavity when compared with the Wistar rats.

Age Factors↗

PubMed1989

Cystic arteriovenous malformation. A case report.

The authors report on a rare case of arteriovenous malformation (AVM) associated with cyst formation. Only five similar cases have been reported. CT findings of the cyst are divided into two types: 1) slit-like low density and 2) round one. Three patients showing slit-like cysts had experienced sudden severe headaches, probably due to haemorrhage. In contrast, two patients showing round cystic lesions had not experienced such sudden headaches and they revealed a nodule in the cyst at surgery. These facts suggest that there may be two different mechanisms for cyst formation in AVM's: haemorrhage and exudation. Slit-like cysts may result from old haemorrhage from the AVM nidus. Round cystic lesions may be due to exudation from the AVM nidus.

Adult↗

PubMed1989

[Arteriovenous malformation associated with cyst. Case report].

The authors present the fifth reported case of arteriovenous malformation (AVM) associated with cyst formation. Among these five cases, computed tomography has demonstrated two types of cyst: round, and slit-like with low density. The three patients with slit-like cysts experienced sudden, severe headache, probably due to hemorrhage. The two patients with round cystic lesions did not have sudden headache, and at surgery the cysts were found to contain a mural nodule. These facts suggest that there may be two different mechanisms of cyst formation in the vicinity of an AVM: hemorrhage (slit-like cysts) and exudation (round cysts).

Adult↗

PubMed1989

[Intracranially recorded trigeminal compound action potential: with special reference to trigeminal neuralgia].

To elucidate the origin of the early component of the trigeminal sensory evoked potential (TSEP) we reported in 1985, we recorded evoked potentials on the trigeminal root and the brain stem surface intracranially when suboccipital craniectomy was done for exploration of the C-P angle. Patients consisted of 4 who had idiopathic trigeminal neuralgia with microvascular decompression, 1 with glossopharyngeal neuralgia who also had microvascular decompression of the left glossopharyngeal nerve, and 5 patients with different tumors, specifically, Meckel's cave meningioma, two epidermoid cysts of the cerebello-pontine angle, an acoustic neurinoma and a trigeminal neurinoma. Among the tumor patients, all but the one with acoustic neurinoma had trigeminal neuralgia. So altogether, there were 8 patients with trigeminal neuralgia. Constant electrical current was applied to the lower and upper lip for stimulation of the second and third division, respectively. In some cases the electrical current was applied percutaneously to the infraorbital nerve for the stimulation of the second division. The supraorbital nerve was stimulated percutaneously for stimulation of the first division. To record and analyze the potentials, Evomatic 8000 (Dantec) was used. Analysis time was from 10 to 100 msec and the stimulation was repeated 200 times. Trigeminal compound action potential (TCAP) was recorded on the trigeminal nerve just distal to the entrance point to the pons. For the recording TCAP, a gold ball electrode of 1 mm diameter was used with indifferent needle electrode in the neck muscle. In some cases a digital filter was applied to the recorded TCAP. The TCAP evoked by stimulation of the second division had 2 to 8 positive potentials in 8 patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Action Potentials↗

PubMed1987

Stereotactic operation for brain abscess.

Stereotactic management of brain abscess (stereotactic aspiration with external drainage) was performed in 14 patients. Fifteen abscesses in 14 patients were successfully aspirated by this method. After aspiration of the abscess, all patients underwent external drainage for an average of 14.5 days. No complications during aspiration or during external drainage (such as bleeding or infection, respectively) were encountered in our series. Ten out of 14 patients (71.4%) showed excellent prognosis, and 3 of 14 (21.4%) showed good outcome. Only one patient died after the operation, but this was due to lung cancer. Our operative results are quite satisfactory in comparison with operative results reported by other authors.

Adult↗

PubMed1987