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O Sato

Publications and source records attributed to O Sato.

At least 181 records · Page 10Linked to original sources
PubMed1989

A clinicopathologic study of aneurysm formation of glutaraldehyde-tanned human umbilical vein grafts.

To clarify the process of graft degeneration and aneurysm formation we reviewed the angiographic and pathologic findings of three cases where aneurysms developed in glutaraldehyde-tanned human umbilical vein grafts. Seven aneurysms were detected in these three grafts 4 years after implantation. Six aneurysms originated from the bodies of the grafts and one originated from the factory-created anastomosis required for fabrication. Wrinkling and segmentation of the dilated graft documented by arteriography corresponded to mural dissection of the graft wall. Large protrusions near the aneurysms were revealed to be the transmurally dissected graft walls. At the site of dissection, blood escaped through the surrounding mesh of the graft to form a preaneurysmal change. Two aneurysms developed without breakdown of the outer mesh. The aneurysm of factory-created sutures was caused by tearing of the graft wall. Degeneration of human umbilical vein grafts, which appears to ensue inevitably with the passage of time after implantation, leads to the tear of the graft wall and transmural dissection to form aneurysm. In our department, candidates for human umbilical vein graft implantation have recently been restricted to the patients whose life expectancy is limited to only a few years because of the risk of aneurysm formation.

Aged↗
PubMed1989

Innervation of the incisors and periodontal ligament in several rodents: an immunohistochemical study of neurofilament protein and glia-specific S-100 protein.

The present immunohistochemical study by use of antisera against neurofilament protein (NFP) and S-100 protein dealt with the innervation of the upper incisors and periodontal ligament in five species of rodents including the guinea pig, hamster, Mongolian gerbil (Meriones unguicularis), mouse and squirrel (Tamias sibiricus). The innervation pattern of the periodontal ligament and dental pulp in the incisors of five rodents was fundamentally identical to that in the rat, which we have previously demonstrated by the same method. The NFP-positive Ruffini-like corpuscles were concentrated in the middle region of the lingual periodontal ligament in all the species examined, suggesting that this particular arrangement of Ruffini-like corpuscles, possibly stretch receptors, was essential to the rodent incisor. The labial periodontal ligament, on the other hand, contained less numerous NFP-positive nerves, these terminating among collagen fibers as free endings. The gerbil and squirrel in particular possessed only a few nerve fibers in the labial periodontal ligament. It was thus presumed that the labial periodontal ligament might be less significant as a mechanoreceptive site than the lingual periodontal ligament. The NFP-positive pulpal nerves, beaded or smooth in shape, ran parallel to the tooth axis, but never extended to the odontoblastic layer; no subodontoblastic plexus was found in the incisors of any of the rodents. S-100-immunopositive nervous elements were distributed in the periodontal ligament and dental pulp of all the rodent species examined, showing a distribution pattern similar to the NFP-positive nerves. Only in the squirrel did odontoblasts show an intense S-100 immunoreactivity.

Animals↗
PubMed1989

[Biological characteristics of plasmid carrying a repeated deoxyribonucleic acid sequence].

It was found that a plasmid which had a foreign deoxyribonucleic acid (DNA) between two repeated sequences did not multiply in E. coli recBCsbcB, even if it multiplied in wild-type E. coli, E. coli recBC or E. coli recBCsbcBrecF when the insert was longer than 351 base pair. The multiplication of these plasmids were, however, inhibited when a plasmid expressing recF gene was introduced into E. coli recBCsbcBrecF. The inviability of the plasmid carrying the repeated sequence in E. coli recBCsbcB was discussed by the mechanism of recombination, and the functions of recF, recBC and sbcB were speculated. When E. coli recBC was transformed with pDR1 which was a derivative of pBR322 carrying a directly repeated sequence between which a DNA fragment derived from plasmid R6K with its origin was inserted, the intramolecular recombinant appeared. The recombinant recovered was, however, only the plasmid which had the replication origin of pBR322. The result suggests that pBR322 is compatible with pDR1 but R6K is not. The replication origin of R6K seems to be preferrentially used by pDR1.

DNA, Bacterial↗
PubMed1989

Responses of pulpal nerves to cavity preparation in rat molars: an immunohistochemical study using neurofilament protein (NFP) antiserum.

The response of neural elements to a dentin injury was morphologically investigated in rat molars by use of immunostaining for neurofilament protein (NFP). An artificially formed cavity in dentin by drilling rapidly caused the displacement of some odontoblasts into the exposed dentinal tubules, while others were detached from the predentin. The subodontoblastic nerve plexus consisting of NFP-immunoreactive nerves shifted inward together with the separated odontoblasts, while a movement of the nerves into the exposed dentinal tubules was not recognized. The odontoblasts separated from the predentin degenerated and disappeared one day after the cavity preparation; at this time, the subodontoblastic nerve plexus underlying the drilled dentin was remarkably disrupted, presumably losing dentinal sensation of the drilled area. Three days after the cavity preparation, the destroyed odontoblastic layer began to be repaired by newly differentiating odontoblasts; the reparative dentin was produced from 5 to 7 days onward. Numerous NFP-positive nerves, beaded in type, gathered in the odontoblastic layer in accordance with the differentiation of the new odontoblasts. The increased beaded nerve fibers were suggested to represent peptide-containing nerves. In 10-15 days, the reparative dentin accumulated quite remarkably under the cavity area. The NFP-positive subodontoblastic nerve plexus was entirely reconstituted and also regained continuity to its surrounding plexus. The nerve fibers in the reconstituted plexus were mostly non-beaded in type as seen in the control teeth. Since dentinal tubules in the reparative dentin are not normally continuous to the primary dentinal tubules, dentinal sensation may not have been restored.

Animals↗
PubMed1989

[Nasal cavity paraganglioma with intracranial extension. Case report].

A 58-year-old male was admitted following an episode of unconsciousness. Nine years prior to this, he had undergone surgery and radiation therapy for a nasal tumor. Subsequently, he had undergone surgical excision of recurrent nasal tumors and metastases to the cervical lymph nodes. The final pathological diagnosis was paraganglioma. On admission, he had no neurological deficit other than anosmia. Laboratory studies showed no abnormalities in urinary concentrations of vanillylmandelic acid or catecholamines. Computed tomography (CT) demonstrated a calcified, heterogeneously enhanced mass in the anterior ethmoid sinus and bilateral frontal fossa. Cerebral angiography revealed a mesh-like tumor stain. Through a bifrontal craniotomy the intracranial tumor was totally removed. It was hypervascular and clearly demarcated from the surrounding cerebral tissue. The pathological diagnosis was paraganglioma without malignant features. Radiation therapy was administrated postoperatively at a total dose of 5060 rads, and follow-up CT showed regression of the ethmoid sinus tumor. As of 2 years postoperatively, the tumor has not recurred.

Brain Neoplasms↗
PubMed1989

Indications for cisternal drainage in conjunction with early surgery in ruptured aneurysms and timing of its discontinuation.

The efficacy of cisternal drainage in association with early aneurysmal surgery remains highly controversial. The authors attempted to clarify the indications for this procedure and the proper timing of drainage removal in a series of 205 patients with no evidence of intracerebral hematoma who underwent surgical obliteration of bleeding aneurysms within 72 hours after subarachnoid hemorrhage. The 136 patients in whom cisternal drainage was performed constituted Group A and the remaining 69 patients Group B. The acid-base balance and lactate concentration were measured serially in cisternal cerebrospinal fluid (CSF) and arterial blood of 33 patients. Subarachnoid blood demonstrated by computed tomography (CT) was graded according to the system of Fisher et al. The outcome at 6 months did not differ significantly between Groups A and B among patients of preoperative CT grade 2 and clinical grades I-II. However, among patients of CT grade 3 or clinical grade III, those in Group A had better outcomes. The rates of symptomatic vasospasm in Groups A and B were 39.7% and 40.6%, respectively. However, persistent vasospasm was more frequent in Group B (11.8% vs. 26.1%), particularly in CT grade 3 patients. Ventricular enlargement was more prevalent in Group A (33% vs. 17%). CSF pH higher than arterial pH after the 7th postoperative day was associated with a poor outcome and was fairly well correlated with a rise in CSF HCO3- and a fall in CSF PCO2. CSF lactate increased with clinical deterioration but was not well correlated with preoperative CT findings, total volume of CSF outflow, or prognosis.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

[Peripheral superior cerebellar artery aneurysm. Case report].

The patient, a 37-year-old female, was hospitalized with a severe headache. Neurological examination on admission revealed no deficits except for neck stiffness and somnolence. Computed tomography showed a subarachnoid hemorrhage, which was especially prominent in the supracerebellar and quadrigeminal cisterns, but demonstrated no ventriculomegaly. Cerebral angiography on admission revealed no apparent abnormalities, but repeat angiography 8 days later disclosed a saccular aneurysm (2 X 3 mm) arising from the hemispheric branch of the left superior cerebellar artery (SCA). Three days after admission, the patient developed cerebellar dysarthria, which was assumed to be due to vasospasm. On the 24th day after admission, the aneurysm was successfully clipped through the infratentorial-supracerebellar approach. The postoperative course was uneventful and the patient was discharged with no neurological deficit. Nineteen other cases of peripheral SCA aneurysm have been reported in the literature. The presence of this type of aneurysm should be considered in patients who are fairly young and have focal neurological signs, such as third or fourth nerve palsy and/or cerebellar dysfunction. The prognosis for such patients is good, except in cases in which the neurological status is poor at the onset.

Adult↗
PubMed1989

[Low-dose dopamine treatment of patients in nonketotic hyperosmolar hyperglycemic coma].

In the acute neurosurgical setting, nonketotic hyperosmolar hyperglycemic coma (NHC) is thought to be caused by cerebral dehydration therapy and administration of steroids, glycerol, or mannitol. The mortality of this complication is reportedly very high, and is due to acute renal and/or cardiac failure. The authors evaluated the effect of low-dose dopamine (LDD; 1 to 5 micrograms/kg/min) administration in 10 patients with this syndrome. LDD was given to five patients. In these cases, hypovolemia was treated under central venous pressure monitoring with an iso-osmolar hyponatremic lactate solution given in a volume greater than the urine output. After the hypovolemia was corrected, the fluid was administered in a volume equal to the urine output until the serum osmolarity was normalized. In the five patients not given LDD, a large quantity of hypotonic solution was rapidly administered. In all patients treated with LDD, the urinary sodium increased and the urinary output stabilized. Consequently, the excess urea-nitrogen and serum sodium were quite easily washed out. The total net intake volume for the normalization of serum osmolarity was small and the duration of treatment was much shorter than that of patients not treated with LDD. The LDD regimen was not associated with complications, such as aggravation of cerebral edema, renal failure, or cardiac failure. On the other hand, three of the five patients not given LDD died of acute renal and/or cardiac failure without normalization of laboratory data. It is emphasized that this therapy, which results in beta-effect of catecholamine, sodium diuresis, and increased renal blood flow, is a practical means of managing acute neurosurgical cases complicated by NHC.

Adult↗
PubMed1989

[Case report: hemiballism due to a putaminal cavernous hemangioma].

A rare case of reversible hemiballism due to putaminal pathological process in a 51-year-old woman is described. She was hospitalized for evaluation of hemiballism and muscle weakness on the left side. A cranial computed tomography scan demonstrated a high density lesion in the right putamen with enhancement on delayed scan. Angiographic examination revealed no apparent abnormalities. Magnetic resonance imaging with T1 weighted showed a isodense lesion in the right putamen, while T2 weighted image revealed a ring like low signal area around a high signal lesion. These findings were compatible with the diagnosis of cavernous hemangioma. In order to establish the final diagnosis, CT-guided stereotaxic biopsy was carried out. But histological specimen showed only gliosis and calcification. Immediately after the biopsy, a small hemorrhage took place in the right putamen extending to the head of caudate nucleus head. Following this episode, hemiballism ceased, however, it gradually returned along with absorption of hemorrhage. The speculated pathophysiology of this on-and-off hemiballism was as follows; it initially developed as the result of suppression of inhibitory fibers from the striatum to the pallidum by a minor hemorrhage of putaminal cavernous hemangioma, and ceased by declining the activities of the pallidum due to interruption of excitatory fibers from the thalamus and the cortex to the striatum.

Brain Neoplasms↗
PubMed1989

Craniopharyngioma with extension into the cerebellopontine angle. Case report.

A rare case of craniopharyngioma which extended from the suprasellar region into the cerebellopontine angle (CP angle) is reported. This patient, a 18-year-old man who underwent two surgeries for suprasellar craniopharyngioma did not show recurrence during interval studies. However, nine years after the second surgery CT scan and MRI indicated a left CP angle mass when he was submitted to suboccipital craniectomy and tumor resection. He had been on human growth hormone (hGH) regimen for his pituitary dwarfism before tumor recurrence. The authors speculate retrospectively that the tumor growth in the left CP-angle was correlated with hGH therapy in this particular case.

Adolescent↗
PubMed1989

Change in glucose metabolism with time in hydrocephalic rats.

Energy metabolism was studied by measurements of the activity and isozyme pattern of lactate dehydrogenase (LDH) in rats with kaolin-induced hydrocephalus at 1, 2, 4, and 6 weeks after the induction, as well as in normal, control rats. The total LDH activity in hydrocephalic rats was 1.5 times that in controls throughout the examination period. The main LDH isozyme in hydrocephalic rats was LDH 5(M4) at 2 weeks, but the isozyme pattern was the same as in controls at 4 and 6 weeks. These results suggest that the ratio of anaerobic to aerobic glycolysis increases in the acute stage of hydrocephalus and gradually lowers to become similar to that in controls with time.

Anaerobiosis↗
PubMed1988

Filiform papillae as a sensory apparatus in the tongue: an immunohistochemical study of nervous elements by use of neurofilament protein (NFP) and S-100 protein antibodies.

Nervous elements supplying the filiform papillae of the tongue of cattle and rats were investigated using immunohistochemistry against neurofilament protein (NFP) and glia-specific S-100 protein. The rod-shaped bovine filiform papillae were heavily keratinized along their entire length and lacked the connective tissue core that occurs in other mammals. Instead, the core was located posterior to the filiform papilla. The base of the bovine filiform papillae was invaded vertically by laminar connective tissue papillae. The core contained a large number of NFP-positive nerve fibers, most of them terminating as free endings in its anterior margin. NFP-positive nerves gathered around the anterior ridge of the epithelium at the base of the core and occasionally penetrated into the epithelium. The laminar connective tissue papillae at the base of the filiform papilla also contained NFP-positive nerve fibers. The core contained S-100-immunoreactive lamellated corpuscles, which were identified as "simple corpuscles" in electron micrographs. The structure and innervation of the bovine filiform papilla suggest that they represent a specialized sensory apparatus. The pyramidal filiform papillae of the rat were smaller, each containing a simple connective tissue core. Few NFP-positive nerve fibers from the nerve plexus entered the core. Filiform papillae are thus less specialized in rats than in cattle.

Animals↗
PubMed1988

Innervation of periodontal ligament and dental pulp in the rat incisor: an immunohistochemical investigation of neurofilament protein and glia-specific S-100 protein.

Nervous elements in the periodontal ligament and dental pulp of rat incisors were investigated by means of immunohistochemistry for neurofilament protein (NFP) and glia-specific S-100 protein. The periodontal ligament in the incisors was densely innervated by NFP-immunoreactive nerve fibers; the distribution of the nerve fibers and their terminations differed markedly from those in molars. NFP-positive, thick nerve bundles entered the lingual periodontal ligament through slits located in the mid-region of the alveolar socket, and immediately formed numerous Ruffini-like corpuscles. In the labial periodontal ligament, all of the NFP-immunoreactive nerve fibers terminated in free endings. The restricted location of the stretch receptor, Ruffini-like corpuscle, in the lingual periodontal ligament appears to be an essential element, because this region is regularly extended during mastication. The nervous elements were restricted to the alveolar half of the periodontal ligament in every region; they avoided the dental half of the periodontal ligament, which presumably moves continuously with the tooth. Pulpal nerve fibers in incisors also showed a characteristic distribution different from those in molars; individual nerve fibers with beaded structures ran in the center of the pulp toward the incisal edge, and did not form the subodontoblastic nerve plexus of Raschkow. Immunostaining for S-100 protein revealed a distribution pattern of nervous elements similar to that for NFP, suggesting that the nerves supplying the periodontal ligament and dental pulp were mostly covered by a Schwann sheath.

Animals↗