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Biomedical subjects

N Hatano

Publications and source records attributed to N Hatano.

52 records · Page 3Linked to original sources
PubMed1991

[The functional relationship between the cerebral cortex and deep brain areas in normal individuals].

Recent PET or SPECT studies have demonstrated a reduction of blood flow and metabolism in the cortex ipsilateral to a deep-seated lesion, and in the thalamus and/or basal ganglia ipsilateral to a cortical lesion. A close relationship between the cerebral cortex and deep areas of the brain has been shown in pathological conditions, presumably because of functional interconnections between the cortex and deeper area. The present study was designed to investigate the relationship of cerebral blood flow in the cerebral cortex to that in the deep gray matter including the basal ganglia and the thalamus in normal subjects. Twenty-two healthy subjects were studied using SPECT with N-isopropyl-p[123I]iodoamphetamine while in a resting state. The asymmetry index (AI) of blood flow in both the cerebral cortex and deep gray matter was calculated as follows; AI = (R-L)/(R+L)/200 (%) (R: right side, L: left side). The AI in deep gray matter was significantly correlated with the AI values in the upper frontal cortex (r = 0.54, p less than 0.01), and parietal cortex (r = 0.58, p less than 0.01), as well as the mean cortical hemispheric AI (r = 0.48, p less than 0.05). Our results suggest the existence of a functional relationship between the cerebral cortex and deep areas not only in pathological conditions but also in the resting state in normal subjects. This functional relationship is likely to be mediated by neuronal mechanisms through the projectional fiber connections between the cortex and the deep gray matter.

Adult↗
PubMed1991

[Functional relationship between the cerebrum and cerebellum in normal subjects].

To determine whether a functional relationship between the cerebrum and cerebellum exists in normal subjects, the correlation between asymmetry in cerebral blood flow and asymmetry in cerebellar blood flow was investigated. Twenty-one healthy right-handed subjects were studied using SPECT with N-isopropyl-p-(123I)iodoamphetamine while in a resting state. The asymmetry index (AI) for both the cerebral and cerebellar hemisphere was calculated as follows. AI = R - L/R + L/200 (%) (R: right side, L: left side). A negative correlation was found between AI in the cerebellum and AI in cerebrum. Especially, AI in cerebellar hemisphere was significantly correlated with AIs in the upper frontal cortex (r = -0.58, p less than 0.01), middle frontal cortex (r = -0.55, p less than 0.02), lower frontal cortex (r = -0.49, p less than 0.05), and mean cerebral hemisphere (r = -0.52, p less than 0.02). These results suggest the existence of a functional relationship between the cerebral hemisphere and the contralateral cerebellar hemisphere in the resting state of normal subjects. We strongly suspect that the frontal cortex exert an influence on the function in the contralateral cerebellum, probably due to a transneuronal mechanism, mainly through the corticopontocerebellar pathway.

Adult↗
PubMed1990

[Remote effects in cerebral infarction--123I-IMP SPECT study].

We studied the remote effects in 29 patients with middle cerebral artery territory infarction by using single photon emission computed tomography (SPECT) with N-isopropyl-p-[123I]iodoamphetamine. SPECT demonstrated a reduction in blood flow in the cerebellar hemisphere contralateral to the cerebral infarct, the cortex ipsilateral to the subcortical infarct, the visual cortex distal to the optic radiation lesion, and the thalamus ipsilateral to the cortical infarct. In addition to transient neuronal depression identified with diaschisis, our results indicated that persistent phenomena were apparently involved in these remote effects. The degenerative processes might be related to irreversible effects in remote areas. Clinical symptoms corresponding to the areas of hypoperfusion remote from infarcted lesions were not necessarily present.

Aged↗
PubMed1990

[Asymmetry of cerebral blood flow in patients with senile dementia of Alzheimer type by SPECT using I-123 IMP].

Regional cerebral blood flow (rCBF) was determined by single photon emission CT (SPECT) with N-isopropyl-p-[123I]iodoamphetamine in 22 patients with clinically diagnosed senile dementia of Alzheimer type (SDAT) and in 18 age matched controls. We calculated asymmetry indices (AIs) of rCBF for matched right-left regions of interest. rCBF of parietal lobe in SDAT patients was significantly most laterally asymmetrical, but the least in occipital lobe. Lateral asymmetry of rCBF in SDAT patients correlated with asymmetry of language and visuospatial functions; decreased rCBF in the left parietal lobe was associated with language dysfunction, and that in the right parietal lobe, with visuospatial dysfunction. Furthermore cerebellar AIs correlated negatively with those of the cerebral hemisphere and lower frontal region in SDAT patients. The results demonstrate that rCBF measurement by 123I-IMP SPECT is useful to detect lateral asymmetry in reduction of rCBF in SDAT.

Aged↗
PubMed1989

[Clinical study on the relationship between middle cerebral artery lesions and Binswanger type infarction].

To investigate the relationship between middle cerebral artery (MCA) trunk lesions and the etiology of Binswanger type (B type) infarction, which was demonstrated as a diffuse subcortical low density area/high intensity area by CT/MRI, patients with both MCA lesions and B type infarction were studied clinically. Eighteen patients with B type infarction were diagnosed among 224 patients with MCA occlusion/stenosis on angiography accounting for 8%. The incidence was as high as 25% in M2 stenosis. The mean age of B type infarction patients was 64 years and 16 of them were men. Chronologically stepwize/slowly-progressive deterioration of clinical manifestations were observed in 14. All patients had hemiplegia, though half of them were mild or moderate in severity. Furthermore, aphasia, Gerstmann syndrome and dementia were present in 10, 1 and 2 patients, respectively. Twelve had a history of hypertension, while 11 showed transient decreases with marked changes (more than 31 mmHg in mean arterial blood pressure) in arterial blood pressure during their clinical course. Out of 9 patients in whom cerebral blood flow (CBF) was measured by 133Xe injection method/inhalation method, 7 demonstrated mild to moderate decreases in mean CBF (more than 30 ml/100 g/min) with no relation to the severity of MCA lesions. These findings suggested that hemodynamic mechanisms associated with hypoperfusion due to marked fluctuations in blood pressure are accelerating factors of B type infarction and MCA lesions, even though ischemia in the subcortical area due to leptomeningeal anastomosis may be mild or moderate.

Aged↗
PubMed1989

High-energy, low-dose radiation therapy for aneurysmal bone cyst. Report of a case.

Whereas curettage and bone grafting of aneurysmal bone cysts (ABC) are generally accepted, recurrence is not uncommon and surgery is hazardous when the lesion is large and adjacent to the growth plate. High-energy, low-dose radiation in an eight-year-old girl with this lesion of the distal tibia was successful with no recurrence at the three-year follow-up examination. No complications have ensued, and excellent function has been sustained. Further evaluation of this form of radiation treatment is important in similar situations in which surgical excision of ABC may carry high risks.

Bone Cysts↗
PubMed1986

Protective effect of a new prostacyclin analogue OP-2507 against cerebral anoxia and edema in experimental animals.

Protective effects of OP-2507 [15-cis-(4-propylcyclohexyl)-16,17,18,19,20-pentanor-9-deoxy -9 alpha, 6-nitrilo-PGF1 methyl ester] against cerebral anoxia and edema were investigated in a variety of experimental models in mice and rats. OP-2507 given s.c. or p.o. led to a consistent and dose-dependent prolongation of survival time against cerebral anoxia in hypobaric and normobaric hypoxia, KCN-induced anoxia and decapitation-induced gasping. Furthermore, treatment with 0.03-0.1 mg/kg s.c. or 0.3 mg/kg p.o. of OP-2507 was found to be effective against the changes of cerebral energy metabolites and cyclic nucleotides in hypoxic brain. In brain ischemia induced by bilateral ligation of common carotid arteries of rats, a reduction in specific gravity of cortex and an increase in water content of brain were observed, in accordance with changes of cerebral energy metabolites. These edematous and biochemical changes were prevented by the treatment with 0.01-0.03 mg/kg s.c. of OP-2507. These results indicate a potential usefulness of OP-2507 in protecting the brain from oxygen insufficiency resulting from cerebral ischemia.

Animals↗
PubMed1986

Protective effect of prostaglandins D2, E1 and I2 against cerebral hypoxia/anoxia in mice.

The protective effect of prostaglandins (PGs) against cerebral hypoxia/anoxia was investigated with a variety of experimental models in relation to their CNS depressant effects in mice. Furthermore, the effect of PGs on the changes of cerebral energy metabolites and cyclic nucleotide was examined in hypoxic mice. Mice were given s.c. doses of PGs 30 min before tests. Among the PGs tested, treatment with PGD2, PGE1 and PGI2 Na showed a consistent and dose-dependent protection against cerebral anoxia induced by all models studied: histotoxic anoxia by KCN, hypobaric hypoxia, normobaric hypoxia and decapitation-induced gasping. However, PGA1, PGA2, PGB1, PGB2, PGE2, PGF1 alpha, PGF2 alpha and 6-keto-PGF1 alpha at a dose of 3 mg/kg were without effect against normobaric hypoxia and gasping duration. The three PGs, i.e. PGD2, PGE1 and PGI2 which showed anti-hypoxic effects decreased locomotor activity and potentiated hexobarbital-induced sleep. On the other hand, PGE2, PGA1, PGA2 and PGB2 also caused a decrease in locomotor activity. Similarly, PGE2 and PGA1 caused a potentiation of hexobarbital-induced sleep, but interestingly they did not cause clear-cut increase in cerebral resistance to hypoxia, in contrast with the former three PGs. Thus general depression of CNS function appears not to be responsible for the PGD2-, PGE1- and PGI2-induced increase in cerebral resistance to hypoxia. The levels of Cr-P and ATP were significantly reduced and those of ADP and AMP were markedly elevated in hypoxic brain, resulting in a decrease in a calculated energy charge potential. The lactate level and lactate/pyruvate ratio increased and the glucose level decreased markedly.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenine Nucleotides↗
PubMed1986

Effect of the novel orally active angiotensin converting enzyme inhibitor alacepril on cardiovascular system in experimental animals.

Effects of 1-[(S)-3-acetylthio-2-methylpropanoyl]-L-prolyl-L-phenylalanine (alacepril, DU-1219) a new orally active angiotensin converting enzyme (ACE) inhibitor, on cardiovascular system in experimental animals were examined. In conscious renal hypertensive dogs, alacepril (3 mg/kg p.o.) caused a marked reduction in systolic and diastolic blood pressure (SBP and DBP) and total peripheral vascular resistance (TPR), but did not change significantly heart rate (HR), cardiac output (CO), stroke volume (SV), cardiac work (CW) and electrocardiogram (ECG). Captopril (3 mg/kg, p.o.) showed similar changes in cardiovascular parameters as alacepril. In anesthetized open-chest normotensive dogs, alacepril (3-100 micrograms/kg/min for 10 min, i.v. infusion) tended to decrease DBP and TPR, but did not change significantly CO, stroke work (SW), left ventricular end diastolic pressure (LVEDP), dp/dt and HR. Captopril also showed similar effects but these changes were greater in extent than those of alacepril. In conscious renal hypertensive rats, alacepril did not affect the regional cerebral blood flow in the frontal cortex and the dorsal hippocampus after single (3 and 10 mg/kg) and successive (3 mg/kg/d for 7 days) oral administration. Captopril (10 mg/kg) significantly decreased blood flow in the frontal cortex after single oral administration. In conscious normotensive dogs, alacepril (3 and 30 mg/kg p.o.) increased renal plasma flow (RPF), urine volume (UV), urinary sodium excretion (UNaV) and urinary Na+/k+ ratio, but did not change glomerular filtration rate (GFR) and urinary potassium excretion (UKV). Captopril (3 and 30 mg/kg p.o.) also showed similar changes as alacepril. These effects of alacepril on cardiovascular system resemble those of captopril and might be considered as a favourable profile for the antihypertensive agent.

Animals↗
PubMed1980

Pharmacological evaluation of OP 1206, a prostaglandin E1 derivative, as an antianginal agent.

Effects of OP 1206 were studied on the cardiovascular system and platelet functions to assess OP 1206 as an antianginal agent. OP 1206 given orally at more than 100 micrograms/kg relieved vasopressin-induced ST depression of rat electrocardiogram (ECG), an animal model of angina pectoris, concomitant with slight hypotension. Intra-coronary injection of OP 1206 (1-100 ng/kg) in dogs resulted in a remarkable increase of coronary blood flow without any influence on heart rate, blood pressure, myocardial oxygen consumption and redox potential. Resistance in both large and small vessels of dog coronary artery was decreased by intravenous injection of OP 1206 (1-3 micrograms/kg). Platelet aggregation, adhesiveness, bleeding time, and thrombocytopenia induced by ADP and collagen infusion in guinea-pigs were inhibited by oral administration of OP 1206 at the same doses or doses less than those relieving vasopressin-induced ST depression of ECG. These results suggest that OP 1206 contributes to the improvement of cardiac imbalance between oxygen demand and supply, and suppression of thrombus formation in atherosclerotic heart.

Alprostadil↗
PubMed1975

Pharmacological studies of 3-[bis(3,3-diphenylpropyl)-amino]-propan-1-ol hydrochloride, (PF-244), a new cerebral vasodilator.

Pharmacological effects of 3-[bis(3,3-diphenylpropyl)-amino]-propan-1-ol-hydrochloride (PF-244) mainly on cerebral and cardiovascular systems, were studied. PF-244 indicated a potent cerebral vasodilation effect and a marked increase in oxygen supply to cerebral tissue with only weak inotropic action and depressor effect. This cerebral vasodilation was more potent and specific than that of papaverine hydrochloride in regional cerebral flow. PF-244 also indicated an antibarium action, although it did not show the properties related to the cholinergic and/or adrenergic mechanism. PF-244 appears to be one of the potent cerebral vascular dilators, and the nature of its mechanism was discussed.

Animals↗
PubMedDate not supplied

A 3-year prospective multicenter follow-up report on the immediate and delayed-immediate placement of implants.

A total of 264 implants was placed in 143 patients using different immediate or delayed-immediate implant placement techniques in 12 different centers participating in a prospective multicenter study. The reason for tooth extraction was evaluated; bone quality and quantity were classified; socket depths were registered; and data on implant type, size, and position were collected. One hundred thirty-nine suprastructures were placed on 228 implants in 126 patients. A follow-up evaluation was done on 125 patients after 1 year of loading and on 107 patients after 3 years of loading. Clinical parameters (bleeding or not bleeding, pocket depth, and implant mobility) were evaluated after 1 and 3 years, and the marginal bone level after 1 year of loading was measured on radiographs. Clinical comparisons were performed to evaluate implant loss in relation to implant type, size, position, bone quality and quantity, socket depth, reason for tooth extraction, and placement method. In addition, life table analysis was done for cumulative implant survival rates. There was no clinical difference with respect to socket depth or when comparing the different placement methods. A higher failure rate was found for short implants in the posterior region of the maxilla and when periodontitis was cited as a reason for tooth extraction. Mean marginal bone resorption from the time of loading to the 1-year follow-up was 0.8 mm in the maxilla and 0.5 mm in the mandible. Over a period of 3 years, the implant survival rate was 92.4% in the maxilla and 94.7% in the mandible.

Bone Density↗
PubMedDate not supplied

Pancreatic metastasis from renal cell carcinoma causing massive gastrointestinal bleeding in von Hippel-Lindau disease.

Patients with von Hippel-Lindau disease (VHLD) may develop pancreatic lesions, including cysts, serous cystadenomas and islet cell tumors. However, only a few cases of pancreatic metastasis have been reported. We present a case of VHLD with multiple pancreatic metastases from renal cell carcinoma. One of the metastases invaded the duodenum, causing massive bleeding.

Carcinoma, Renal Cell↗