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Biomedical subjects

A Terashi

Publications and source records attributed to A Terashi.

At least 127 records · Page 7Linked to original sources
PubMed1991

Effect of a new hyperosmotic agent, NIK-242 injection, on brain water content, metabolites and cerebral blood flow in cerebral ischemia in the spontaneously hypertensive rat.

We examined the effects of a new hyperosmotic agent (NIK-242inj.) on brain edema, energy metabolites and regional cerebral blood flow (r-CBF) during acute cerebral ischemia. Cerebral ischemia was induced by bilateral common carotid artery ligation (BLCL) using spontaneously hypertensive rats (SHR). The experimental animals were divided into 4 groups, A:20% NIK-242inj., B:20% mannitol, C:10% glycerol in 5% fructose, D:normal saline. All the animals were administered the agent or saline intravenously beginning at 1h after BLCL and continuing for 2h for a total dose of 6.8 ml/kg body weight. Brain water content and metabolites (ATP, lactate, pyruvate) were determined 3h after BLCL. Regional cerebral blood flow (r-CBF) in thalamus was also measured by the hydrogen clearance technique. The brain water content in the NIK-242inj. group was significantly lower than that of saline group. The concentration of brain ATP in the NIK-242inj. group remained higher than those of saline group. Accumulation of lactate in the NIK-242inj. group was less than in the mannitol and saline groups. The lactate/pyruvate ratio of the NIK-242 inj. group was significantly lower than that of the saline and mannitol groups. At 3h after BLCL, the reduction of r-CBF in the NIK-242inj. group was smaller than that of saline group. The present study suggests that NIK-242inj. as well as glycerol could ameliorate brain edema, disruption of brain energy metabolism and reduction of r-CBF in acutely induced cerebral ischemia.

Animals↗
PubMed1991

[A case of adrenomyeloneuropathy with marked spinal cord atrophy on magnetic resonance imaging].

A 29-year-old man complained of increasing paraplegia and sphincter disturbances. On admission, he was 23 years old. He had moderate pigmentation of the skin, and his neurological examinations revealed spastic paraplegia, hyperreflexia of both legs with Babinski's signs, a pinprick sensation deficit below the L-1 level, loss of vibration sense in the lower extremities and horizontal nystagmus on lateral gaze. Endocrinological examinations revealed adrenocortical insufficiency. CSF, EEG, EMG, brain-CT and myelography did not show any abnormalities, but metrizamide CT myelography at the low thoracic spinal cord revealed decreased cord diameter. Nerve conduction velocities showed impairment in the tibial and peroneal motor fibers. Auditory brain-stem response revealed elongated III-V interval. A cystometrogram disclosed a reflex neurogenic bladder. In the analysis of the fatty acid component of plasma sphingomyelin, the C26/C22, C25/C22, C24/C22 ratios were found to be increased, and the diagnosis of adrenomyeloneuropathy (AMN) was confirmed. The patient's mother was also found to be asymptomatic carrier of AMN on the basis of long chain fatty acid plasma levels. The MRI performed in his age of 29 years, showed marked spinal atrophy from low cervical to low thoracic regions and mild cerebellar atrophy. This findings seems to correspond with chronic progressive demyelination of spinal white matter such as pyramidal tract and fasciculus gracilis.

Adrenoleukodystrophy↗
PubMed1990

CSF beta-endorphin, HVA and 5-HIAA of dementia of the Alzheimer type and Binswanger's disease in the elderly.

Cerebrospinal fluid (CSF) concentration of beta-endorphin (beta-Ep), homovanillic acid (HVA) and 5-hydroxyindoleacetic acid (5-HIAA) was measured in 15 patients with dementia of the Alzheimer type (DAT) and in 16 patients suspected of having Binswanger's disease (BD) by MRI, which sometimes resembles DAT clinically. These were classified into three stages according to severity of dementia, Stage 1 (mild dementia)-Stage 3 (severe dementia). CSF levels of HVA decreased significantly in severe dementia, but the level of 5-HIAA did not correlate with dementia severity in both dementia groups. beta-Ep levels did not differ significantly between any stages of DAT, and among controls. beta-Ep levels, however, in BD Stage 1 (27.5 +/- 5.9 pg/ml) were significantly higher (p less than 0.05), but level in Stage 3 (6.7 +/- 2.0) was significantly lower (p less than 0.001) than in the controls (19.2 +/- 4.5). These results suggest that CSF beta-Ep may depend on the cause of dementia rather than severity of dementia, and could possibly distinguish the closely resembling BD from true DAT.

Alzheimer Disease↗
PubMed1990

Role of platelets as a factor aggravating cerebral ischemia.

In order to clarify the role of platelets as a factor aggravating cerebral ischemia, an experimental model of ischemia was investigated using thrombocytopenic rats. In addition, the prostacyclin derivative (OP-41483) and the thromboxane A2 synthetase inhibitor (OKY-046), both of which inhibit platelet aggregation, were tested for possible beneficial effects on cerebral ischemia. Cerebral ischemia was produced in spontaneously hypertensive male rats using bilateral common carotid artery ligation (BLCL). Thrombocytopenia was produced with an antiplatelet antiserum which reduced the platelet count to less than 6 x 10(4)/microliters by 24 h. OP-41483 was administered four times hourly (500 ng/kg x 4, i.p.), beginning 1 h prior to BLCL. Similarly, OKY-046 was injected four times hourly (10 mg/kg x 4, i.p.). Brain metabolites such as ATP, lactate and pyruvate and water content were determined after 3 h of cerebral ischemia. Brain levels of ATP in the ischemic rats with thrombocytopenia were higher than those of the ischemic rats without thrombocytopenia. In addition, thrombocytopenia reduced the increase of lactate and water content in the ischemic brain. Animals treated with OP-41483 also maintained higher levels of ATP and lower levels of lactate and water compared to animals given a vehicle. OKY-046 significantly reduced brain water content, but had no effect on the ischemic alteration of brain metabolite levels. These results indicate that platelets play an important role in the progression of metabolic change during ischemia.

Adenosine Triphosphate↗
PubMed1990

[The effects of antihypertensive therapy on the aged--an intervention study in a home for the aged].

Excessive antihypertensive therapy can create a risk of brain damage in the aged. Furthermore, no conclusion has been reached regarding treatment goals for systolic blood pressure (SBP). Two hundred elderly people with hypertension (SBP greater than 170 mmHg, average age 74 years) were studied, among them 40 age-sex matched pairs (80 people) were selected for further examination. They were then divided into two groups, and antihypertensive therapy was conducted on each group with systolic blood pressure level goals of 140 mmHg and 160 mmHg, respectively. To set a goal for antihypertensive therapy, we examined Hasegawa's dementia rating scale (HDS) and bilateral common carotid arterial blood flow (CCF), which were measured using the Doppler method. In the group in which the blood pressure was reduced to 160 mmHg level, changes were observed only in right CCF, and there was no change in HDS, but in the group in which the blood pressure was reduced to the 140 mmHg level, changes were observed in both bilateral CCF and HDS. It is recommended that the systolic blood pressure should be set at the 160 mmHg level to maintain the psychological function in the elderly.

Aged↗
PubMed1990

[The correlation between the activity of tissue plasminogen activator (TPA), levels of tissue plasminogen activator inhibitor (PAI-1) antigen and serum lipids in healthy subjects].

It is well known that abnormality of the coagulation-fibrinolytic system and serum lipids plays an important role in the development of thrombi and atherosclerotic disease. In the present study, the correlation between the activity of tissue plasminogen activator (TPA), the levels of tissue plasminogen activator inhibitor (PAI-1) and serum lipids (TC, TG, beta-Lp, HDLC, LDLC and apolipoproteins) were studied in 102 healthy subjects. The activity of TPA showed negative correlation with the obesity rate (r = 0.21, p less than 0.05) but levels of PAI-1 antigen showed a positive correlation with the obesity rate (r = 0.182, p less than 0.1). The activity of TPA showed no correlation with serum lipids including apolipoproteins, while the levels of PAI-1 antigen showed a positive correlation between TG and beta-Lp (r = 0.292, p less than 0.01, r = 0.211, p less than 0.05). The levels of PAI-1 antigen showed a negative correlation with HDLC (r = -0.286, p less than 0.01). These results indicate that TPA and PAI-1 play an important role in the development of thrombotic disease and atherosclerotic disease.

Adult↗
PubMed1990

[Cerebral blood flow and cerebral oxygen metabolism in patients with dementia of frontal lobe type].

This study was designed to investigate the differences in cerebral blood flow (CBF) and cerebral metabolic rate of oxygen (CMRO2) between patients with dementia of frontal lobe type and patients with Alzheimer's disease. Positron emission tomography (PET) using 15O steady state inhalation technique was carried out in 5 patients with a clinical diagnosis of dementia of frontal lobe type and 7 patients with a clinical diagnosis of Alzheimer's disease. CBF and CMRO2 were significantly decreased in the frontal cortex except for precentral region in patients with dementia of frontal lobe type in comparison to those values in patients with Alzheimer's disease. However, in patients with dementia of frontal lobe type CBF and CMRO2 in the parietal cortex and the occipital cortex were relatively preserved when compared with patients with Alzheimer's disease. In comparison with values for CBF and CMRO2 in the posterior part of brain [frontal or temporal/(parietal + occipital)/2 ratio], both values in the frontal cortex were markedly decreased in all 5 patients with dementia of frontal lobe type, but there was no marked reduction in the frontal cortex in patients with Alzheimer's disease. In addition, in 2 patients with dementia of frontal lobe type whose duration of the disease was more than 7 years, CBF and CMRO2 in the temporal cortex were markedly reduced in comparison with values in the posterior part of brain. These results suggested that PET findings of marked reduction in CBF and CMRO2 in the frontal cortex are useful to distinguish dementia of frontal lobe type from Alzheimer's disease.

Adult↗
PubMed1990

Role of arachidonic acid metabolism on ischemic brain edema and metabolism.

Arachidonic acid is liberated from damaged cell membranes during ischemia and is the source of vasoactive prostanoids. In this study, specific drugs that influence AA metabolism were investigated for their effects on brain edema and energy metabolites during ischemia. The agents tested were: methylprednisolone (phospholipase A2 inhibition), indomethacin (cyclooxygenase inhibitor), trapidil (TXA2 synthetase inhibitor), and OP-41483 (prostacyclin derivative). Cerebral ischemia was produced using bilateral common carotid artery occlusion in spontaneously hypertensive rats. Brain water content and concentrations of ATP, pyruvate, and lactate were determined 3 hr after occlusion. Compared with its vehicle, methylprednisolone significantly reduced water content and lactate concentration and maintained high levels of ATP. Indomethacin had no effect on brain water content nor metabolite levels. Trapidil decreased water content and lactate levels and increased levels of ATP and pyruvate. OP-41483 had no effect on water content and lactate, but maintained ATP and pyruvate at high levels. These results indicate that some of the AA metabolites may play an important role in the development of brain edema and in the impairment of energy metabolism.

Animals↗
PubMed1990

Effects of fluosol-DA on brain edema, energy metabolites, and tissue oxygen content in acute cerebral ischemia.

Perfluorochemicals were developed as a blood substitute and were reported to have an advantage in oxygen transport compared with blood. The present study was undertaken to investigate the therapeutic effects of a perfluorochemical, FDA, on brain edema and metabolites in acute cerebral ischemia. Cerebral ischemia was induced in SHR by BLCO followed by recirculation. The FDA administration resulted in (a) the significant inhibition of brain edema as shown by brain water content in the treated group, and (b) significant amelioration of metabolic impairments as shown by lesser degree of ATP and pyruvate decrease and lactate accumulation. The TpO2 was compared between FDA-infused and nontreated group during ischemia. The FDA-infused group had significantly higher TpO2 than nontreated group. These results indicate that the improvement of brain edema and metabolite levels were due to alleviation of ischemic hypoxia by FDA under the same ischemic insult.

Animals↗
PubMed1990

[Measurements of cerebral blood flow and metabolism in patients with Alzheimer's disease].

Positron emission tomography (PET) was used to measure cerebral blood flow (CBF), cerebral metabolic rate of oxygen (CMRO2), and cerebral metabolic rate of glucose (CMRglc) in patients with Alzheimer's disease. In the patients, values for CBF, CMRO2, and CMRglc have been shown to drop by 30-50% in comparison to age-matched normal controls. In the early stage (stage I), reductions in CBF and CMRO2 are prominent in the temporal and the temporoparietal cortices. In stage II, reduction in the parietal cortex also become quite prominent, and in the late stage (stage III) reduction begins prominently in the frontal cortex as well. These PET findings in Alzheimer's disease differ from those in vascular dementia, Pick's disease, and Huntington's disease. In the interrelationship among CBF, CMRO2 and higher brain function, CBF and CMRO2 decrease especially in the left frontal, the left temporal and the left parietal cortices in patients with marked language disability. On the contrary, CBF and CMRO2 decrease in the right temporal and the right parietal cortices in patients with marked apraxia and visuospatial deficits. Cerebral blood flow and metabolism are closely related to the functioning of nerve cells. Therefore we can isolate the region responsible for higher brain dysfunction and similarly evaluate the effects of treatment using cerebral blood flow and metabolism measurements.

Aged↗