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Biomedical subjects

J Ogata

Publications and source records attributed to J Ogata.

198 records · Page 11Linked to original sources

Strong and significant relationships between aggregation of major coronary risk factors and the acceleration of carotid atherosclerosis in the general population of a Japanese city: the Suita Study.

BACKGROUND: Carotid arterial intimal-medial thickness (IMT) measured by high-resolution B-mode ultrasonography has come to be used as a noninvasive surrogate end point to measure progression of atherosclerosis. However, there are no detailed data on the relationship between aggregation of coronary risk factors and carotid atherogenesis. METHODS: Cross-sectional assessment of the relationship between carotid atherosclerosis detected by high-resolution ultrasonography and integration of major coronary risk factors by age and sex. Subjects aged 30 to 86 years were randomly selected from Suita, located in Osaka, the second largest urban area of Japan, including 1896 men and 2102 women. Carotid atherosclerosis was evaluated by using our atherosclerotic indexes of IMT, plaque number, plaque score, and percentage of stenosis of the carotid artery assessed using ultrasonography by sex and age group classified by number of major coronary risk factors (ie, hypertension [diastolic blood pressure > or =90 mm Hg and/or systolic blood pressure > or 140 mm Hg or receiving medication], smoking [current smoker], and hypercholesterolemia [serum total cholesterol level > or =5.68 mmol/L [220 mg/dL] or receiving medication]). RESULTS: The mean carotid atherosclerotic index value, especially the mean IMT value, of the subjects with 1 major coronary risk factor was on average 0.028 mm (3.2%) higher for men and 0.025 mm (2.9%) higher for women than that of the subjects without major coronary risk factors; for subjects with 2 risk factors, 0.054 mm (6.3%) higher for men and 0.053 mm (6.2%) higher for women; and for high-risk subjects with 3 major risk factors, 0.135 mm (15.8%) higher for men and 0.137 mm (15.4%) higher for women. The percentage of the subjects with severe stenosis of at least 50% increased stepwise with increases in the number of coronary risk factors and showed a significant difference (P<.05) between men and women, ie, 2.4% vs 0. 6% (P =.01) among the subjects with no risk factors; 6.7% vs 1.5% (P<.001), subjects with 1 risk factor; 10.7% vs 2.7% (P<.001), subjects with 2 risk factors; and 18.6% vs 5.0% (P =.01), high-risk subjects. CONCLUSIONS: Aggregation of established major coronary risk factors strongly influenced carotid atherogenesis in both sexes. There were significant differences between sexes in the acceleration or progression of carotid atherosclerosis.

Adult↗

Vascular dementia: the role of changes in the vessels.

The role of changes in the vessels in vascular dementia (VaD) was reviewed through histopathology. Because Binswanger's subcortical arteriosclerotic encephalopathy is a common type of VaD, and it forms a homogenous group among the subtypes of VaD, arteriopathy in the subcortical structure was the main focus. Fibrohyalinosis and fibrinoid necrosis with segmental arterial disorganization are the two cardinal features of arteriopathy in the subcortical structures. From the viewpoint of neuropathological changes in VaD, notes were made of the areas that need to be explored in future studies and revised clinical criteria for VaD were proposed.

Blood Vessels↗

Cerebral artery thrombosis as a cause of striatocapsular infarction. a histopathological case study.

Striatocapsular infarction is a distinct form of stroke, but few histopathological studies have been performed concerning acute lesions. We report the postmortem findings of a patient with an infarct who died shortly after onset. A 72-year-old man died of acute myocardial infarction 6 days after the onset of left-sided striatocapsular infarction. Autopsy revealed thrombus formation of the left middle cerebral artery (MCA) trunk. The lateral striate arteries irrigating the area of the infarct branched off distal to the arterial segment occluded with a thrombus. The cortical vessels were perfused by leptomeningeal collaterals. This report histopathologically confirmed thrombus formation of the MCA resulting in striatocapsular infarction.

Aged↗

Influence of sex on cerebral ischemia following bilateral carotid occlusion in spontaneously hypertensive rats: a metabolic study.

Cerebral lactate, pyruvate and adenosine triphosphate (ATP), and acid-base balance were measured in male and female spontaneously hypertensive rats (SHR) before, and 1, 3 and 5 hours after bilateral carotid occlusion. In male SHR, cerebral lactate and the lactate/pyruvate (L/P) ratio progressively increased after occlusion, while cerebral ATP decreased. In female SHR, an increase in lactate and the L/P ratio was less marked than in male SHR. Cerebral ATP remained unchanged 5 hours after occlusion. These data suggest that bilateral carotid artery occlusion may cause more pronounced ischemic changes in the brain in male SHR than in female SHR, resulting in a greater increase in lactate with a concomitant decrease in ATP in male SHR. Results suggest that female SHR are more resistant to cerebral ischemia following bilateral carotid occlusion than male SHR. Blood pressure and gonads in the susceptibility to cerebral ischemia are discussed.

Adenosine Triphosphate↗

Brain metabolism following bilateral carotid occlusion in 2 different models of experimental hypertensive rats.

Brain metabolites and arterial acid-base measurements were made one hr after bilateral carotid artery occlusion in 2 different models of hypertensive rats. Animals used included renovascular hypertensive rats (RHR) with an altered renin-angiotensin system and desoxycorticosterone hypertensive rats (DHR) with low plasma renin activity (PRA). The mean value for supratentorial lactate of 7.41 mM/kg in RHR was significantly higher than in DHR (3.90 MM/kg) or in control normotensive rats (3.10 - 2.56 mM/kg). Concomitantly, the lactate/pyruvate ratio tended to increase and ATP to decrease in RHR only. In these same rats (RHR) infratentorial lactate was also increased. The results suggest that bilateral carotid occlusion leads to anaerobic metabolism of the brain in RHR but not in DHR, suggesting that the renin-angiotensin system may play some role in the susceptibility to cerebral ischemia following carotid occlusion in the hypertensive rats.

Adenosine Triphosphate↗

Disruption of blood-brain barrier following bilateral carotid artery occlusion in spontaneously hypertensive rats. A quantitative study.

The present study was designed to clarify the relationship of cerebral blood flow (CBF) to blood-brain barrier (BBB) in the ischemic brains with or without recirculation, which were produced by clipping of both common carotid arteries in spontaneously hypertensive rats. CBF was measured by the hydrogen clearance method and BBB function was evaluated by the permeability of 131I-albumin and Evans blue dye. Cortical CBF was reduced from 48.8 +/- 9.5 to 4.0 +/- 1.2 ml/100 gm/min during 1 hr ischemia and further to 2.6 +/- 0.3 ml/100 gm/min during 3 hrs ischemia, while thalamic CBF was reduced much less from 50.0 +/- 3.6 to 17.9 +/- 6.5 ml/100 gm/min and to 17.5 +/- 11.0 ml/100 gm/min, respectively. There was no increase in permeability to protein tracers observed in such 1 hr or 3 hrs ischemic brain. Both cortical and thalamic CBF were markedly increased 2.5 to 6 fold of resting values at 5 min after recirculation in the 1 hr ischemic brain. In the 3 hrs ischemic brain, however, both CBF were only slightly increased but never restored to the resting level even at 30 min after recirculation. In such reperfused brains, exudation to Evans blue dye was observed in none of 16 animals with 1 hr ischemia, but in 18 of 23 with 3 hrs ischemia. Disruption of BBB was twice more frequent in the cortex (77.8%) than in either thalamus (33.3%) or hippocampus (33.3%). Permeability index of 131I-albumin (brain albumin/blood albumin) was significantly higher in the ischemic areas stained with blue dye (2.07 +/- 0.45%) than in non-ischemic control brain (0.10 +/- 0.01%).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

Cerebral blood flow and tissue metabolism in experimental cerebral ischemia of spontaneously hypertensive rats with hyper-, normo-, and hypoglycemia.

The present study was designed to clarify the effect of blood glucose level on cerebral blood flow and metabolism during and after acute cerebral ischemia induced by bilateral carotid ligation (BCL) in spontaneously hypertensive rats (SHR). Blood glucose levels were varied by intraperitoneal infusion of 50% of glucose (hyperglycemia), insulin with hypertonic saline (hypoglycemia) or hypertonic saline (normoglycemia). Cerebral blood flow (CBF) in the parietal cortex and thalamus was measured by hydrogen clearance technique, and the supratentorial metabolites of the brain frozen in situ were determined by the enzymatic method. In non-ischemic animals, blood glucose levels had no influence on the supratentorial lactate, pyruvate or adenosine triphosphate (ATP) concentrations. In ischemic animals, however, cortical CBF was reduced to less than 1% of the resting value at 3 hours after BCL. However, there were no substantial differences of CBF during and after ischemia among 3 glycemic groups. Cerebral lactate in the ischemic brain greatly increased in hyperglycemia (34.97 +/- 1.29 mmol/kg), moderately in normoglycemia (23.43 +/- 3.13 mmol/kg) and less in hypoglycemia (7.20 +/- 1.54 mmol/kg). In contrast, cerebral ATP decreased in hyperglycemia (0.93 +/- 0.19 mmol/kg) as much as it did in normoglycemia (1.04 +/- 0.25 mmol/kg), while ATP reduction was much greater in hypoglycemia (0.45 +/- 0.05 mmol/kg). At 1-hour recirculation after 3-hour ischemia, ATP tended to increase in all groups of animals, indicating the recovery of energy metabolism. Such metabolic recovery after recirculation was good in hypo- and normoglycemia, and was also evident in hyperglycemia. Our results suggest that hyperglycemia is not necessarily an unfavorable condition in acute incomplete cerebral ischemia.

Adenosine Triphosphate↗

The effect of long-term antihypertensive treatment on medial hypertrophy of cerebral arteries in spontaneously hypertensive rats.

The effects of antihypertensive treatment on the structural changes of middle cerebral arteries (MCA) were studied quantitatively and morphometrically in young spontaneously hypertensive rats (SHR). Fifteen male SHR, 10 weeks of age, were divided into control and experimental groups. In the experimental group, the animals were administered hydralazine and guanethidine for the following 10 weeks. At the age of 20 weeks, mean arterial blood pressure of experimental animals was 177 +/- 9 mm Hg (mean +/- SD), being significantly lower than that of 195 +/- 12 mm Hg in control ones. Media thickness of large (external diameter greater than or equal to 200 micron) and medium sized MCA (150-200 micron) in treated SHR was 12.3 +/- 2.8 and 6.3 +/- 1.1 micron, respectively, being significantly smaller than that of 14.0 +/- 2.2 and 8.5 +/- 2.6 micron, respectively, in control SHR. The media cross-sectional area and the ratio of media thickness to external diameter were also significantly reduced by antihypertensive treatment. In the smaller vessels (75-150 micron), however, vascular morphometry revealed no difference between the two groups. Long-term antihypertensive treatment during the early phase of hypertension attenuates the development of medial hypertrophy in large cerebral arteries.

Animals↗

Artery-to-artery embolism from a thrombus formed in stenotic middle cerebral artery. Report of an autopsy case.

The authors report an autopsy case with repeated transient ischemic attacks and subsequent strokes demonstrating evidence of artery-to-artery embolism from thrombi generated in the stenotic middle cerebral artery to the distal cortical branches. This case substantiates the existence of intracranial artery-to-artery embolism as a cause of transient ischemic attacks and subsequent strokes, and has potential relevance for therapy.

Aged↗

Cerebral infarction following bilateral carotid artery ligation in normotensive and spontaneously hypertensive rats: a pathological study.

A pathological examination was performed on normotensive rats (NTR) and spontaneously hypertensive rats (SHR) following bilateral common carotid artery ligation. After ligation, diffuse and extensive cerebral infarcts in the carotid artery territory occurred frequently in SHR, while NTR occasionally had well-circumscribed small infarcts. The posterior communicating arteries, which are the major anastomotic channels connecting the carotid and vertebrobasilar systems, did not show any anomalies and were well developed in SHR and NTR. Vascular changes secondary to hypertension, such as fibrinoid necrosis or thickening of the wall, were not observed in SHR. Because of the paucity of structural difference of the blood vessels, the more diffuse and extensive cerebral infarcts in SHR after carotid occlusion were attributed to the hemodynamic difference rather than the morphological difference between the two groups. The results of the present experiment suggest that hypertension per se, i.e., hemodynamic factors, may be operative for the development of cerebral infarction.

Animals↗

Prognosis of occlusive cerbrovascular diseases in normotensive and hypertensive subjects.

Comparison of the clinical features, especially prognosis, in cerebral infarction was made between nine normotensive subjects and 16 hypertensive patients with an 80% stenosis or occlusion of the intracranial or extracranial arteries. Our own criteria for evaluating hypertension were employed on the basis of the following items: a past history of hypertension, blood pressure levels on admission and during hospitalization, degree of retinopathy, and ECG changes. In 17 of 25 cases, brain circulation was measured by the intravenous RISA technique. Abnormalities of the EEG and reduction of cranial blood flow were greater, and an early prognosis for neurological deficits in the first two months after the onset of stroke was poorer in the hypertensive group than inthe normotensive group. These results are contradictory to the observations of others.

Adult↗

Effects of acute hypertension on brain metabolism in normotensive, renovascular hypertensive and spontaneously hypertensive rats.

Effects of angiotensin-induced acute hypertension on cerebral metabolism were studied in normotensive (NTR), spontaneously hypertensive (SHR) and experimental renovascular hypertensive rats (RHR). Lactate, pyruvate and adenosine triphosphate (ATP) concentrations in the brain frozen in situ at 18--20 min after angiotensin infusion, which raised mean arterial pressure (MAP) by 28--62% of control, were determined by enzymatic methods. Supratentorial lactate was significantly increased to 135% of control in RHR, its increase being correlated with the degree of hypertension, wherease it remained unchanged in NTR or SHR. Furthermore, RHR showed a tendency toward increase in lactate/pyruvate ratio with a decrease in ATP despite no change of arterial acid-base balance measured simultaneously before and after acute induced hypertension. From the present study, it is postulated that some renal factor seems to contribute ischemic metabolic changes in RHR following acute hypertension. The possible effect of renin on the vascular permeability is discussed as the pathogenesis of hypertensive encephalopathy.

Acute Disease↗

Brain step tumor and otoneurologic manifestations: report of a case with autopsy.

The otoneurologic findings in a 30-year-old male patient who died of a brain stem tumor have been correlated with the histopathology of the temporal bones and brain. The patient was examined on two occasions. A sensorineural hearing loss, which was moderate in the right ear and mild in the left ear, was found. Abnormal vestibular function, indicative of central pathology, was also demonstrated. The right side of the medulla oblongata and pons was largely replaced by the tumor. The cochlear and vestibular nuclei and their connecting fibers were involved with the tumor. Histopathological changes were more prominent in the right cochlea and VII nerve than in the left and were minimal in the vestibular portion of the labyrinths. The otoneurological finding suggested a central nervous system (CNS) lesion, and the morphologic observations confirmed the central origin of the symptoms and signs. Manifestations of lesions of the central auditory and vestibular pathways are discussed.

Adult↗

Primary and metaplastic choriocarcinoma of the bladder. A report of two cases.

Two cases of primary choriocarcinoma arose in the urinary bladder in males aged 72 and 70 years. Human chorionic gonadotropin (hCG) in serum and urine was significantly elevated in both cases. Cytologic features consisted of bizarre mononucleate and multinucleate giant cells with numerous erythrocytes, necrotic cells and neutrophils, indicating the possibility of choriocarcinoma. Histologically, one tumor consisted of an admixture of choriocarcinomatous areas and transitional cell carcinoma (TCC) with or without syncytiotrophoblastic differentiation, and the other was composed of pure choriocarcinoma. Immunohistochemical examination revealed that syncytiotrophoblasts and a small number of TCC cells were intensely positive for hCG in their cytoplasm. The histogenesis of choriocarcinoma arising in the bladder is considered to be metaplasia or retro-differentiation from TCC to trophoblasts because of TCC's differentiating to hCG-positive trophoblasts, as seen in one of the present cases.

Aged↗

Intraarterial infusion of cisplatin with and without preoperative concurrent radiation for urinary bladder cancer: a preliminary report.

We evaluated the clinical efficacy of treating urinary bladder cancer by intraarterial infusion of cisplatin using an implanted reservoir with and without preoperative concurrent radiation. No previous reports have compared the results obtained by these two methods of treatment. Twenty-three patients with bladder cancer were treated by intraarterial infusion of cisplatin using an implanted reservoir with (n = 13) and without (n = 10) concurrent radiation. The cisplatin plus radiation group received intraarterial cisplatin at a total dose of 200-400 mg and concurrent radiation to a total dose to 30 Gy. The cisplatin group received intraarterial cisplatin at a total dose of 100-600 mg. In the cisplatin plus radiation group, the overall tumor response rate was 92%. Seven of 13 (53%) patients obtained complete response (CR), and the 2-year actuarial survival rate was 92%. Only one of the seven complete responders has had a local recurrence. In the cisplatin group, the overall tumor response rate was 90%. Four of 10 (40%) patients obtained CR, and median survival was 8 months. Three of the four complete responders have had local recurrence. There was no significant difference between these two groups in the frequency of side effects. Concurrent radiation therapy with intraarterial cisplatin resulted in a very low rate of recurrence of bladder cancer compared with intraarterial cisplatin therapy alone. This method was useful for urinary bladder cancer and may become the treatment of choice for this type of cancer.

Aged↗