PubMed Health⌕ Search

Biomedical subjects

N Nakao

Publications and source records attributed to N Nakao.

At least 19 recordsLinked to original sources
PubMed1992

Effectiveness of Lipiodol in transcatheter arterial embolization of hepatocellular carcinoma.

The effectiveness of Lipiodol (iodized oil) in transcatheter arterial embolization (TAE) of hepatocellular carcinoma (HCC) was retrospectively evaluated using statistical analysis. A total of 343 HCC patients who underwent TAE at 5 institutions between 1984 and 1989 were divided into 2 groups: the GS-TAE group underwent TAE with Gelfoam sponge alone, whereas the LP-TAE group was given Lipiodol (LP) immediately before GS-TAE. The statistical T value calculated for the LP-TAE group showed that the administration of LP, the tumor size, intrahepatic metastasis, portal vein infiltration, and serum total bilirubin and alpha-fetoprotein levels significantly (P < 0.01) affected the patients' survival. Both the cumulative survival determined using the Kaplan-Meier model and the cumulative hazard calculated using Cox's proportional hazard model differed significantly (P < 0.01) between the GS-TAE group and the LP-TAE group (log-rank test). These results confirmed the effectiveness of LP used in combination with Gelfoam sponge for TAE of HCC.

Aged↗
PubMed1992

A possible involvement of central atrial natriuretic peptide in cerebral cortical microcirculation.

The possible involvement of atrial natriuretic peptide (ANP) in cerebral cortical microcirculation was investigated in rats by means of laser-Doppler flowmetry and immunohistochemistry. In the laser-Doppler study, local cerebral blood flow (LCBF) changes after the administration of 10(-6) to 10(-8) mol/LANP solution or vehicle (saline solution) as an intracortical injection for 5 minutes were continuously monitored throughout the 30 minutes of the study and were expressed as percentages of preinjection values represented as 0%. The administration of 10(-6) to 10(-8) mol/LANP caused a significant decrease in LCBF; the onset of LCBF responses occurred within a few minutes after the start of the injection and the decrease in LCBF reached the maximum level within 7 to 10 minutes after the completion of the administration, after which LCBF gradually recovered. In the immunohistochemical study, no specific ANP immunoreactivity was found associated with the intraparenchymal blood vessels; however, ANP-immunoreactive neurons were observed primarily in the hypothalamus and septum, in which high concentrations of ANP-containing neurons have been identified. The data from the laser-Doppler study suggest that central ANP may produce a vasoconstriction of the intraparenchymal blood vessels, regardless of whether through direct action on these vessels or through the mediation by some system in the central nervous system. Because there is no evidence for ANP-containing nerves around these vessels, the role of central ANP in the cerebral circulation must await identification of the source of perivascular ANP.

Animals↗
PubMed1992

Cranial metastasis of hepatocellular carcinoma associated with chronic epidural hematoma--case report.

A case of cranial metastasis of hepatocellular carcinoma associated with epidural hematoma in a 58-year-old male is presented. The epidural hematoma demonstrated an unusual chronic clinical course and computed tomographic appearance. Associated bleeding from either the diploic marrow or emissary veins might be a cause of the slowly expanding hematoma, and the outward displacement of the artificial bone-flap implanted previously may also have contributed to the chronic course.

Carcinoma, Hepatocellular↗
PubMed1992

High resistance of cultured Mongolian gerbil cells to X-ray-induced killing and chromosome aberrations.

The Mongolian gerbil (Meriones unguiculatus) is known to be one of the most radioresistant animals. We have examined the X-ray sensitivity of normal diploid fibroblasts from Mongolian gerbil embryos compared with those of cultured embryo cells obtained from various laboratory animals and a normal human. There was a wide difference in X-ray sensitivity for cell killing among different mammalian species. The D0 values for Mongolian gerbil cells ranged from 2.08 to 2.28 Gy, values which are twice as high as those for human cells. The mean D0 value for human cells was 1.06 Gy. Mouse, rat, Chinese hamster, and Syrian/golden hamster cells showed similar D0 values ranging from 1.30 to 1.56 Gy. When cells were irradiated with X rays, ten times more chromosome aberrations were detected in human cells than in Mongolian gerbil cells. The frequencies of chromosome aberrations in other rodent cells were between the values for cells from humans and those from gerbils. These data indicate that the Mongolian gerbil cells are resistant to X-ray-induced cell killing and chromosome aberrations, and that the radiation sensitivity of mammalian cells in primary culture may be reflected by their radioresistance in vivo.

Animals↗
PubMed1992

[Diseases of the autonomic nervous system. General aspect of symptomatology].

The human internal environment is regulated by the autonomic nervous system (ANS), endocrine glands and neuropeptides as well as the integrated activity of these three systems. The ANS is divided into thoraco-lumbar (sympathetic) and cranio-sacral (parasympathetic) divisions. They comprise two neurons: pre- and post-ganglionic fibers. The limbic system and hypothalamus are known to regulate the peripheral ANS through descending pathways in the brain stem and spinal cord. Cardinal semiologies of the ANS disorders are classified as follows: cardiovascular (orthostatic hypotension, a variety of syncopes, postprandial hypotension, Raynaud's phenomenon), pupillomotor (paralytic mydriasis, Adie's tonic pupil, Horner's syndrome), urodynamic (urinary retention and incontinence), and sexual (impotence, hyper- and hyposexuality).

Animals↗
PubMed1992

[Autonomic facio-cephalalgia].

Autonomic facio-cephalalgia was first described by Brickner et al. in 1935. At that time, it's clinical picture was characterized as pain seizure in the head or face unilaterally with various autonomic signs, such as swelling, redness and hyperthermia of the painful regions. After the first case was described, few cases have been reported, including our two cases. Thus, it's definite clinical entity can not be determined at present. In this review, the history, symptoms, signs, differential diagnosis of this disease and details of two our cases are described. The clinical entity of this disease, on bases of present knowledge is discussed.

Adult↗
PubMed1991

Multiple growths of primary calvarial meningiomas.

The authors present the case of a 68-year-old woman with multiple growths of primary calvarial meningiomas. Histological examination revealed one tumor arising in the left parietal bone that showed some malignant aspects, including hypercellularity, cellular pleomorphism, necrotic foci, and some mitoses; the tumor partially had a meningotheliomatous pattern. Two other tumors in the right parietal bone were meningotheliomatous meningiomas without any malignant features. With a review of the literature, the pathogenesis of the multiplicity is discussed.

Aged↗
PubMed1991

Unusual posttraumatic porencephaly--case report.

An unusual case of posttraumatic porencephaly preceded by neither overt cerebral contusion nor hemorrhage is reported. The cerebral cortex just above the porencephalic cyst was found intra-operatively to be partially herniated into a fracture line, while the cortex elsewhere was completely intact. The porencephalic cyst communicated with the lateral ventricle. Apparently, brain herniation and the cyst-ventricle communication can be causative factors in the occurrence and growth of posttraumatic porencephaly.

Adult↗
PubMed1991

Effect of oxiracetam on cerebrovascular impairment in rats.

The effect of oxiracetam (CGP 21690E, CAS 62613-82-5) on cerebrovascular impairment was investigated in rats. 1. After injection of tranylcypromine (a MAO inhibitor), spontaneously hypertensive rats (SHR) which had been previously infused with norepinephrine (NE) for 14 days displayed stroke-related behaviour including kangaroo-like posture, seizures and death. Administration of oxiracetam at doses of 400 and 800 mg/kg/d p.o. for 14 days before tranylcypromine injection inhibited the stroke-related behaviour. 2. Bilateral common carotid and vertebral artery occlusion induced electroencephalogram (EEG) flattening, the EEG recovering gradually after re-perfusion of cerebral blood flow. Oxiracetam administered after the re-perfusion at a dose of 100 mg/kg, i.v. accelerated the recovery. This facilitatory effect was not seen when either piracetam (50 and 100 mg/kg i.v.) or idebenone (50 and 100 mg/kg i.v.) were administered. 3. Occlusion of middle cerebral artery produced cerebral infarction and disturbed the circadian rhythm of spontaneous motor activity with an relative increase of activity in the light period. Treatment with oxiracetam (400 mg/kg/d p.o.) for 14 days after the occlusion showed a tendency to an improvement in the disturbed circadian rhythm but did not influence the size of brain infarction. From these results, oxiracetam is thought to have a protective effect in cerebrovascular impairment.

Animals↗
PubMed1991

[Semiquantitative histological evaluation of IgA nephropathy and Cox's proportional Hazzard model analysis].

In order to examine the relationship between microscopic findings and the prognosis of patients with IgA nephropathy, a multiple regression lifetable analysis was performed using a Cox's proportional Hazzard model. Histological changes were evaluated on the basis of nine parameters. By using the changes in serum creatinine concentration (S-Cr) as the criterion for assessing the prognosis, calculations were made at two points, the first point of S-Cr reached 2 mg/dl and the second of 4 mg/dl following the biopsy. As a result, the following conclusions were obtained: 1) At the S-Cr value of 2 mg/dl, two regression coefficients for mesangial lesions and crescent formations showed a correlation (P less than 0.10) with respective risk ratios of 4.517 and 9.970. 2) At the S-Cr value of 4 mg/dl, the regression coefficient for complete glomerular sclerosis was statistically significant (P less than 0.05) with a risk ratio of 6.527. Mesangial lesions and tubulo-interstitial lesions had a risk ratio ranging from 3.0 to 4.0. 3) In assessing renal histological findings in IgA nephropathy, it is important to take consideration into the variations in the severity and the stage of the renal dysfunction. 4) Although statistical significance of the pathological findings could not be achieved, such speculation as described before was made. More definitive conclusions may be attained by the longer following up on the clinical course, increasing the number of patients to be examined, and devising a more appropriate method for the evaluation of renal tissue lesions.

Glomerular Mesangium↗
PubMed1991

[Massive osteolysis of the skull--case report and review of the literature].

The authors describe a rare case of massive osteolysis of the skull, along with a brief review of the literature. A 11 year-old female was admitted with a complaint of a painless depression in the right parietal region, which had been slowly enlarging for several years. Skull x-ray films revealed a radiolucent area with irregular and non-sclerotic margin in the right parietal bone. Plain CT showed an osteolytic lesion involving the outer table and diploë with absence of new bone formation. On 99mTc scintigrams, there were no abnormal accumulation in the whole skeletal system including the skull. Blood examinations including serum calcium, phosphate, and alkaline phosphatase were entirely normal. In the differential diagnosis of lytic skull lesion, the long, inactive course without any corroborative local or systemic evidence of illness, and the absence of new bone formation on radiological examinations clinch the diagnosis of massive osteolysis.

Alkaline Phosphatase↗
PubMed1991

[A case of sphenoid ridge meningioma presenting as subarachnoid hemorrhage].

The authors present a case of sphenoid ridge meningioma presenting as subarachnoid hemorrhage. A 56-year-old man came to our hospital with a complaint of severe headache developed during evacuation of the bowels. Computed tomogram on admission revealed a mass lesion of high density, which was homogeneously enhanced with contrast media, in the medial part of the left sphenoid ridge, but no evidence of the intracranial hemorrhage. Nevertheless, the cerebrospinal fluid obtained by lumbar puncture was bloody, indicating the occurrence of subarachnoid hemorrhage. Cerebral angiograms showed no abnormality except for the downward displacement of the suprachnoidal segment of the left internal carotid artery. During the operation, the adhesion between the tumor and the cortical vein was observed and the subarachnoid hemorrhage was recognized exclusively around the vein. These findings indicates that the present hemorrhage may be derived from the vein. In the previous reports of meningioma associated with intracranial hemorrhage, the origin of hemorrhage and the pathophysiological mechanism for hemorrhage have been speculated from both operative and histological findings. In consideration of these speculations, we discussed the possible mechanism for the breakdown of the cortical vein in the present case.

Humans↗
PubMed1990

Effect of atrial natriuretic peptide on ischaemic brain oedema.

We investigated the effect of intraventricularly administered atrial natriuretic peptide (ANP) on the brain water, sodium and potassium contents in ischaemic brain oedema. Global ischaemia (15 min) followed by recirculation (30 min) produced by a three vessel occlusion in the rat served as a model for induction of ischaemic cerebral oedema. Water content was measured by a drying-weighing method. Sodium and potassium contents were measured by means of flame photometry. The effect of ANP was evaluated by comparing these parameters of the ANP-treated group (5 micrograms/kg and 10 micrograms/kg atriopeptin) with those of the control group (administration of 0.9% NaCL). ANP did not significantly change the content of water, sodium and potassium in the preischaemic or ischaemic brain. Intraventricularly administered ANP (5 micrograms/kg and 10 micrograms/kg) caused significant decrease in the brain water (p less than 0.02) and sodium (p less than 0.01) contents after 15 min of ischaemia and 30 min of recirculation, while the brain potassium content remained unaltered. Serum osmolality, and sodium and potassium concentrations were not influenced by administration of ANP. Accordingly, ANP acts directly on the central nervous system to inhibit brain water and sodium accumulation in ischaemic brain oedema.

Animals↗
PubMed1990

Type I familial amyloid polyneuropathy. A pathological study of the peripheral nervous system.

The neuropathological changes were examined in 2 cases of type I familial amyloid polyneuropathy (FAP), confirmed by a genetic study with human transthyretin (prealbumin) cDNA. These cases were from different foci of type I FAP in Japan, but showed a similar pathology in the peripheral nerves. Loss of dorsal root and sympathetic ganglion neurons, predominantly those of small size, was prominent, whereas ventral horn cells were well preserved. Distally accentuated axonal loss with marked axonal sprouting was the principal feature. Fibre sprouts were ubiquitous throughout the nerves and affected the fibre size distribution. Segmental demyelination and remyelination were prominent in the proximal portions of nerves, but axonal degeneration was more conspicuous in the distal portions. The centrally-directed branches of the primary sensory neurons did not show distally-accentuated axonal loss in the dorsal columns. Amyloid deposits were present universally in the endoneurial spaces of the peripheral nerves, but more prominently in the dorsal root ganglia, sympathetic ganglia and more proximal portions of the nerves, and the distribution correlated well with the occurrence of the pathology of peripheral nerves. Neurofilamentous accumulation was frequent in the proximal axons and neuronal cell bodies of the sensory and sympathetic neurons. Schwann cells and satellite cells to which amyloid deposits were attached frequently showed disappearance of basement membrane and proliferation of distorted processes. The findings in the present cases suggest that the Schwann and satellite cells may be directly affected by the amyloid deposits, but the pathogenetic mechanism of marked axonal and neuronal involvement still remains to be elucidated.

Adult↗
PubMed1990

Effect of atrial natriuretic peptide on ischemic brain edema: changes in brain water and electrolytes.

The effects of intraventricularly administered atrial natriuretic peptide (ANP) on the brain water, sodium, and potassium contents in ischemic brain edema were investigated. By use of a three-vessel occlusion model, ischemic brain edema was produced in the rat brain by 15 minutes of global ischemia followed by recirculation. Water content was measured by means of a drying/weighing method; sodium and potassium contents were measured by means of flame photometry. The effects of intraventricular administration of ANP were evaluated by a comparison between the groups given 2 and 5 micrograms of atriopeptin II (treated) and those given 0.9% NaCl (sham-treated). The treated groups showed significant decreases in brain water (P less than 0.02) and sodium (P less than 0.01) contents at 15 and 30 minutes after recirculation, whereas the brain potassium contents remained unaltered. Before ischemia and immediately after 15 minutes of ischemia, intraventricularly administered ANP did not significantly change the brain water, sodium, or potassium contents. There was no significant difference in the effect on the amount of brain water and sodium between the two doses (2 and 5 micrograms). These effects of ANP were thought not to be mediated by primary changes in serum osmolality and sodium and potassium concentrations, because intraventricular administration of ANP did not change them significantly. The present results reveal that, in ischemic brain edema, ANP may act directly on the central nervous system to inhibit brain water and sodium accumulation.

Animals↗
PubMed1990

[Barotraumatic cerebral air embolism following scuba diving].

The authors report a case of barotraumatic cerebral air embolism following scuba diving, in which air embolism was diagnosed by CT. This kind of disorder becomes more frequent with the greater popularity of scuba diving. A healthy 24-year old woman made a rapid ascent with breath hold after a scuba dive to 8 meters for 20 minutes. On surfacing, she felt chest pain radiating to the cervical region. Shortly thereafter, she developed visual obscuration and weakness in the right arm and leg. On admission, neurological examination revealed right hemiparesis with hemisensory disturbance. Visual acuity was counting fingers at 1 meter in the right eye and only perception of hand movement in the left. CT obtained 10 hours after the onset revealed no abnormality except for a small area of air density. A chest x-ray film revealed mediastinal emphysema tracking into the neck. T2-weighted MRI 22 hours after the onset revealed multiple areas of high intensity, suggesting ischemic lesions, in the left hemispheric white matter. The visual disturbance, probably due to air embolism in the retinal vessels, was gradually improved and completely disappeared 24 hours after the onset. Nevertheless, there was no change in the motor and sensory disturbance of the extremities. The patient was transferred to an institution with hyperbaric facilities and was given hyperbaric oxygen therapy 30 hours after the accident with almost complete recovery of neurological function.

Adult↗
PubMed1990

[Autonomic dysfunction in vasculitic neuropathy--special reference to sudomotor function].

We examined autonomic functions in 14 patients with peripheral neuropathy caused by necrotizing vasculitis. These patients consisted of three allergic granulomatous angitis (Churg-Strauss syndrome, AGA), two systemic lupus erythematosus (SLE), two progressive systemic sclerosis (PSS), one mixed connective tissue disease (MCTD), one polyarteritis nodosa (PN) and five nonsystemic vasculitis. All of them were proven to have a vasculitis by sural nerve, muscle or skin biopsy. Sixteen age- and sex-matched healthy volunteers were also examined. Local sweating induced by intradermal injection of pilocarpine and nicotine (a concentration of 10(-4) g/dl, 0.1 ml) was measured with ventilated capsular method on the forearm and lower lateral leg at 23 degrees C of room temperature and 40% of relative humidity. Other autonomic functions including skin temperature at rest and after cold loading (15 degrees C, 6 minutes), variation in the R-R interval of heart beat (CV%), orthostatic hypotension and bladder dysfunction were also monitored. A decrease in sweat rate and recovery rate of skin temperature after cold-loading was seen more frequently in patients with necrotizing vasculitis than normal volunteers. Abnormality in the local sweat response against nicotine and pilocarpine was more frequently present in the involved area of somato-sensory and motor nerves as compared with those in the non-involved area. An occurrence of decrease in recovery rate of skin temperature after cold-loading also well correlated to the region of somato-sensory- and motor involvement. So far other autonomic dysfunction, only one patient had orthostatic hypotension, impotence and bladder dysfunction.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗