Cerebral and aortic atherosclerosis in Hisayama, Japan

Apolipoprotein E knockout rabbit model of intracranial atherosclerotic disease

Intracranial atherosclerotic disease (ICAD) is the most common cause of ischemic stroke. Poor understanding of the disease due to limited human data leads to imprecise treatment. Apolipoprotein E knockout (ApoE-KO) rabbits were compared to an existing model, the Watanabe heritable hyperlipidemic (WHHL) rabbit, and wild-type New Zealand white (NZW) rabbit controls. Intracranial artery samples were assessed on histopathology for the presence of ICAD. Logistic and ordinal regression analyses were performed to assess for disease presence and severity, respectively. Eighteen rabbits and 54 artery segments were analyzed. Univariate logistic analysis confirmed the presence of ICAD in model rabbits (P < .001), while no difference was found between WHHL and ApoE-KO rabbits (P = .178). In multivariate analysis, only classification as a model vs wild-type animal (P < .001) was associated with the presence of ICAD. Univariate ordinal regression analysis demonstrated an association between ICAD severity and model animals (P = .001), with no difference was noted between WHHL and ApoE-KO rabbits (P = .528). In multivariate ordinal regression analysis, only classification as a model retained significance (P < .001). ICAD can be reliably produced in ApoE-KO rabbits, developing the disease comparably to the older WHHL model. Further analysis is warranted to optimize accelerated development of ICAD in ApoE-KO rabbits to more efficiently study this disease.

The Origins and Early Evolution of Epidemiologic Research in Cardiovascular Diseases: A Tabular Record of Cohort and Case-Control Studies and Preventive Trials Initiated From 1946 to 1976

This article serves as a ready reference guide to the pioneering formal studies in cardiovascular disease (CVD) epidemiology initiated during 3 decades of the subject's evolution into an established academic field that contributed to the public health. The article is not intended to be a history of CVD epidemiology or an editorial about its significance. The appended tables include the titles and starting dates of the early studies, the names of their principal investigators, and references to a single defining article from each. The early observational studies of CVD epidemiology provided a widely useful CVD risk-factor paradigm. The early clinical trials justified the more definitive preventive trials of the 1980s and beyond. This early research in populations, along with others in clinics and laboratories, led to greater understanding of the causes of CVD, to a vigorous practice of preventive cardiology, and to national policy and programs of health promotion, all of which were coincident with a 50-year decline in CVD mortality rates.

Intracranial Atherosclerosis: From Microscopy to High-Resolution Magnetic Resonance Imaging

Intracranial atherosclerosis is one of the leading causes of ischemic stroke and occurs more commonly in patients of Asian, African or Hispanic origin than in Caucasians. Although the histopathology of intracranial atherosclerotic disease resembles extracranial atherosclerosis, there are some notable differences in the onset and severity of atherosclerosis. Current understanding of intracranial atherosclerotic disease has been advanced by the high-resolution magnetic resonance imaging (HRMRI), a novel emerging imaging technique that can directly visualize the vessel wall pathology. However, the pathological validation of HRMRI signal characteristics remains a key step to depict the plaque components and vulnerability in intracranial atherosclerotic lesions. The purpose of this review is to describe the histological features of intracranial atherosclerosis and to state current evidences regarding the validation of MR vessel wall imaging with histopathology.

Pathologic Study of Intracranial Large Artery Atherosclerosis in 7260 Autopsy Cases

BACKGROUND

Atherosclerotic changes in the cerebral arteries may differ with era of birth. Herein, we analyzed the chronological changes of intracranial atherosclerosis in consecutive autopsy cases.

METHODS

A total of 7260 autopsy cases from 1972 to 2014 were analyzed. Severity of atherosclerosis was classified using a semi-quantitative scale of pathologic observation of each artery after formalin fixation: 0 = no stenosis; .5 = fatty streaks but no stenosis; 1 = <50% stenosis; 2 = 50%-90% stenosis; 3 = ≥90% stenosis. The bilateral vertebral, anterior, middle, and posterior cerebral arteries and the basilar artery were scored. The sum of each individual was defined and compared by age at death, sex, and era of birth.

RESULTS

The atherosclerosis score increased with age at death, as follows: age in the 50s, 0 [0-2]; 60s, 3 [.5-7]; 70s, 5 [2-9.5]; 80s, 6.5 [3.5-11.5]; 90s, 7.75 [4-12]; and 100s, 8 [5.5-13.5] (median value [interquartile range], P< .0001). The percentage of cases with a score of 2 or 3 in each artery also increased with age (P< .0001). Atherosclerosis score was higher in men than women in their 60s at death, and was higher in women than men in their 80s and 90s at death. In each age at death group (from 60s to 100s), the score declined with later year of birth (P < .05).

CONCLUSIONS

Intracranial atherosclerosis advances with age and is more severe in subjects born earlier.

The combination of carotid and lower extremity ultrasonography increases the detection of atherosclerosis in type 2 diabetes patients

OBJECTIVE

To evaluate the prevalence of atherosclerosis detected by both carotid and lower extremity ultrasonography in hospitalized Chinese type 2 diabetic patients and to examine whether plaque formation in the carotid arteries could be an indicator of generalized atherosclerosis in type 2 diabetes mellitus.

METHODS

Totally, 709 hospitalized Chinese type 2 diabetic patients (men 357, women 352) aged from 18 to 88 years were included. Both carotid and lower extremity atherosclerosis were assessed by Doppler ultrasound. Atherosclerosis was defined as the presence of either the carotid or lower extremity plaque in any of the above-mentioned arteries segments. The prevalence of atherosclerosis was calculated, and the risk factors associated with atherosclerosis were evaluated using binary logistic regression.

RESULTS

The prevalence of atherosclerosis was 81.23% in male and 77.56% in female type 2 diabetic patients, respectively. There was no significant difference in the prevalence of atherosclerosis in patients between the sexes. The prevalence of atherosclerosis was significantly higher in the lower extremity arteries than in the carotid arteries (73.91% and 44.43%, respectively, P<.001). Atherosclerosis was significantly associated with smoking, age, duration of diabetes, systolic blood pressure, total number of white blood cells, and mean carotid and femoral intima-media thickness (IMT).

CONCLUSIONS

The prevalence of atherosclerosis was very high in Chinese inpatients with type 2 diabetes. Carotid atherosclerosis could not be an indicator of generalized atherosclerosis in type 2 diabetes. The combination of carotid and lower extremity ultrasound examination can significantly improve the detection of atherosclerosis in type 2 diabetes.

Prevalence of findings compatible with carotid artery calcifications on dental panoramic radiographs

Cerebrovascular accidents are responsible for killing or disabling more than half a million Americans every year. They are the third leading cause of death in this country. In Germany, the annual stroke incidence reaches 182 cases per 100,000 inhabitants. Stroke there is the fourth leading cause of death. There is a need of finding cost-effective means of decreasing stroke mortality and morbidity. Instruments for early diagnosis are of great humanitarian and economic importance. All possible clinical findings should be taken into account. It is not the demand of this study to present the panoramic radiograph as a screening test method for early diagnosis of atherosclerosis. The aim is to show the potential of this radiograph used in everyday clinical dental practice by the prevalence of radiopaque findings in the carotid region. This study included panoramic dental radiographs of 2,557 patients older than 30 years of age. Fifty-nine percent of the patients were women and 41% were men. The radiographs were adjudged for signs compatible with carotid arterial calcifications appearing as a radiopaque nodular mass adjacent to the cervical vertebrae at or below the intervertebral space C3-4. Of all these radiographs, 4.8% showed radiopaque findings compatible with atherosclerotic lesions. The proportion of women reached 64.8% and that of men reached 35.2%. In accordance to recent literature, the results of this study show that about 5% of the patients show radiological findings compatible with carotid arterial calcifications. Some of these patients at risk for a cerebrovascular accident may be identified in the dentist's office by appropriate review of the panoramic dental radiograph. The suspicion of carotid artery calcifications demands an impetuous referral to an appropriate practitioner who can assist in the control of risk factors and if necessary arrange surgical removal of the carotid arterial plaque. So, the dentist should be aware of this problem and able to make a contribution to stroke prevention.

Renoprotective Effects of Rosiglitazone in Stroke-Prone Spontaneously Hypertensive Rats

BACKGROUND/AIMS

Rosiglitazone (RGTZ) has a protective effect against various types of injury. We evaluated the effects of RGTZ on renal injury in a stroke-prone spontaneously hypertensive rat (SHRSP) model.

METHODS

Male SHRSP rats were observed with or without RGTZ treatment for 10 weeks. Age-matched male Wistar-Kyoto rats were used as controls. The effect of RGTZ on hypertensive nephropathy was evaluated by assessing renal function, pathology, pro-inflammatory cytokine (osteopontin), profibrotic cytokine (betaig-h3), apoptotic cell death (TUNEL staining and caspase 3 expression), marker of oxidative stress (8-OHdG) and endothelial damage (eNOS).

RESULTS

RGTZ treatment improved renal function and histopathology compared with SHRSP rats without treatment (p < 0.05). Osteopontin and betaig-h3 were significantly increased in SHRSP rat kidneys, but RGTZ treatment decreased both mediators. Apoptotic cell death was increased in renal tubular cells in the injured area in SHRSP rat kidneys, but RGTZ treatment decreased apoptotic cell death and caspase 3 expression. Increased urinary 8-OHdG excretion and decreased eNOS in SHRSP rats was reversed with RGTZ treatment.

CONCLUSIONS

RGTZ protects hypertensive nephropathy in SHRSP rats.

High fat and high fructose diet induced intracranial atherosclerosis and enhanced vasoconstrictor responses in non-human primate

The present study examined the effect of high fat and high fructose (HFF) diet on the development of atherosclerosis and vascular contractile responses in the cerebral artery and thoracic aorta in non-human primates. Female cynomolgus monkeys (age: 3 to 4 years) were divided into normal control diet (N=5) and HFF diet groups (N=5). Twenty-eight weeks after feeding the HFF diet, total cholesterol and low-density lipoprotein-cholesterol in serum were significantly increased in the HFF diet group compared to the control group. The ultrastructural analyses of the basilar artery and aorta demonstrated the infiltration of lipid-laden foam cells and the appearance of lipid droplet-filled smooth muscle cells in the monkeys fed with the HFF diet. In terms of vascular reactivity, there was significantly greater vasoconstriction of the aorta and basilar artery in response to 5-hydroxytryptamine in the HFF diet group compared to the normal diet-fed group. In addition, KCl-induced vasoconstriction of the basilar arteries was also significantly enhanced in the HFF diet group compared to the normal diet-fed monkeys. In all, our present study has demonstrated that changes in the vascular responsiveness of the cerebral artery and its cellular architecture may manifest into cerebrovascular complications consistent with a pathological state normally observed with the onset and progression of atherosclerosis.

A possible explanation for the racial difference in distribution of large-arterial cerebrovascular disease: ancestral European settlers evolved genetic resistance to atherosclerosis, but confined to the intracranial arteries

The pattern of cerebral atherosclerosis is not the same among different races. White patients rarely have intracranial large arterial steno-occlusive disease even if their systemic arteries are extensively involved, while non-white patients frequently have their intracranial arteries affected. We postulate that during human population diversification, those who settled in Europe had acquired a stroke-suppressor genotype that increases their resistance against atherogenesis, but with protection confined to the intracranial large arteries. The contemporary affluent lifestyle accelerates the development of atherosclerosis. In the whites, it involves the whole arterial bed except the intracranial vessels. People living in non-Western countries used to have a healthier way of living. They did not develop significant atherosclerotic diseases until recently when a westernised lifestyle was adopted. Unlike the whites, their intracranial arteries will not be spared. Atherosclerosis has become a major cause of premature mortality in the modern world, and an anti-atherogenic mechanism would confer a selection advantage. With further adaptive intensification, this protection may extend to the rest of the arterial bed. As a result, future Homo sapiens will be able to tolerate an affluent lifestyle without much adverse sequel such as premature vascular death. Alternatively, if the mediator of this anti-atherogenic mechanism can be identified and applied therapeutically, we will have an ultimate mean to prevent atherosclerosis.

Neurodegenerative diseases: insights into pathogenic mechanisms from atherosclerosis

Increasing evidence indicates that several pathogenic mechanisms promoting atherosclerosis are also involved in neurodegenerative diseases, and that insight into the factors determining the susceptibility to, and long-term progression of, atherosclerosis may be of interest for the evolution of diseases such as Alzheimer's. Furthermore, atherosclerosis of intracranial arteries or thromboembolic consequences of atherosclerotic extracranial arteries are responsible for most ischemic events in the brain. Age-related changes of cerebrovascular atherosclerosis, and atherosclerosis in general, may therefore be important for stroke and neurodegenerative diseases affecting the elderly. In the following, pathogenic mechanism involving increased lipid peroxidation, oxidative stress, inflammation and immune responses, and fetal programming will be discussed in the context of cerebrovascular disease and aging.

Long-term follow-up in japanese public office workers of the influence of blood pressure on ECG changes

BACKGROUND

The relationship between annual changes in blood pressure (BP) and the electrocardiogram (ECG) was studied to clarity what factors give early detection of complications and predict the outcome of therapy.

METHODS AND RESULTS

The influence of BP on the ECG was assessed in 830 Japanese office workers. Those with hypertension (HT) more frequently developed left atrial and ventricular overload compared with normotensive subjects. In addition, those with borderline HT (systolic pressure 140-160 mmHg and/or diastolic pressure 90-95 mmHg) and even those with lower blood pressure (systolic pressure 130-140 mmHg and/or diastolic pressure 85-90 mmHg) developed left atrial and ventricular overload more frequently than normotensive subjects.

CONCLUSIONS

Based on these results, BP should be closely followed up when routine systolic and diastolic pressure levels exceed 130 mmHg and 85 mmHg, respectively, in persons in their 40 s to 50 s and the goal of antihypertensive therapy should be lower than reported previously.

Cerebral atherosclerosis occurs spontaneously in homozygous WHHL rabbits

We demonstrated that selectively bred homozygous WHHL rabbits known to show hypercholesterolemia and severe coronary atherosclerosis also spontaneously develop cerebral atherosclerosis beginning at 9 months of age. These intracranial lesions occurred in the absence of hypertension in 24 of 25 animals at various sites, mainly along arteries at the base of the brain. No lesions were observed in penetrating arteries. Lesions were rich in smooth muscle cells and fibrous tissue, showing only rare fragmentation or disappearance of the internal elastic lamina, and only limited lipid deposition. Few macrophages were observed in these lesions. No significant correlation was seen between severity of cerebral atherosclerosis and age, systolic blood pressure (BP), serum total cholesterol, or triglyceride concentration. Xanthomas of the pia mater were observed in all 25 rabbits. Arterial findings were similar to those in human cerebral atherosclerosis, indicating that the coronary atherosclerosis-prone homozygous WHHL rabbit represents the first animal model for spontaneous cerebral atherosclerosis.

KRH-594, a new angiotensin AT1 receptor antagonist, prevents end-organ damage in stroke-prone spontaneously hypertensive/Izm rats

1. In the present study, we examined whether KRH-594, a new angiotensin AT1 receptor antagonist, would stop the progression of renal failure and end-organ damage and improve the survival rate in salt-loaded stroke-prone spontaneously hypertensive rats (SHRSP/Izm). 2. Oral administration of KRH-594 (3 and 10 mg/kg per day) for 11 weeks significantly reduced systolic blood pressure, urinary total protein, blood urea nitrogen, serum creatinine and urinary N-acetyl glucosaminidase and increased creatinine clearance in SHRSP/Izm. 3. In a histological study, KRH-594 (3 and 10 mg/kg per day) significantly improved the glomerulosclerosis, basophilic change and hyalin cast of tubules, proliferation of afferent arterioles and interlobular artery wall scores of the kidney and the cardiac fibrosis scores of the heart in SHRSP/Izm. KRH-594 (3 and 10 mg/kg per day) also significantly inhibited cardiac hypertrophy. 4. KRH-594 (3 and 10 mg/kg per day) prevented death in SHRSP/Izm during the examination period. 5. These results suggest that KRH-594 improves hypertensive complications, such as renal failure, cardiac hypertrophy and thickening of the artery wall, and prevents death in salt-loaded SHRSP/Izm.

Age-related change of mineral content in the human thoracic aorta and in the human cerebral artery

The relative contents (RCs) of mineral elements in aortae and cerebral arteries from 23 subjects, with ages ranging between 45 and 99 yr, were analyzed by inductively coupled plasma atomic emission spectrometry. The RCs of calcium, phosphorus, and magnesium in the aortae increased markedly after the age of 70. While the RC of sulfur in aortae decreased gradually after that age. It was found that accumulation of calcium and phosphorus occurred primarily in the tunica media of aorta, and secondarily in the tunica intima. Furthermore, the RCs of calcium, phosphorus, and magnesium in cerebral arteries increased markedly after the age of 70, whereas the RC of sulfur in cerebral arteries decreased after age 70. It was found that accumulation of calcium and phosphorus in the cerebral arteries were 30 and 60%, respectively, lower than those in the aortae with ages ranging between 45 and 99 yr.

Cerebral blood flow and metabolism in hypertensive patients with cerebral infarction

The authors investigated, by positron emission tomography, the effect of long-standing hypertension on cerebral blood flow (CBF) and oxygen metabolism in patients with chronic atherothrombotic brain infarction. In the nonbrain infarct (non-BI) group (n = 13, mean age: sixty-two years), the regional CBF (rCBF) was decreased significantly with a rise in the mean arterial blood pressure (MABP) in the cerebral cortexes (r = -0.575) and the deep gray matter (r = -0.451), whereas the regional cerebral metabolic rate for oxygen (rCMRO2) remained unchanged. In the brain infarct (BI) group (n = 22, mean age: fifty-eight years), however, the rCBF as well as the rCMRO2 were reduced even in the normotensive patients and thus did not correlate with the MABP. These results suggest that long-standing hypertension per se causes a reduction in the rCBF but not in the oxygen metabolism with a compensatory increase in the oxygen extraction fraction. On the other hand, patients with brain infarction, even normotensives, show a diffuse decrease in cerebral circulation and metabolism, which is probably due to the more severe sclerotic changes that take place in the cerebral vessels.

The role of platelets in essential hypertension

Recent research is helping us understand the complex interactions that occur between platelets and their environment. The several intracellular events that occur during platelet activation are being identified as ar their effects on other platelets, the endothelium and coagulation factors. Heightened platelet activation is seen early in essential hypertension and probably plays an important role in the initiation and progression of atherosclerosis and the disorders associated with it. This review identifies some of the changes in platelet structure and function in essential hypertension and their role in the pathogenesis of hypertensive vascular disease.

Increase in extracranial atherosclerotic carotid lesions in patients with brain ischemia in Japan. An angiographic study

BACKGROUND AND PURPOSE

Atherosclerotic lesions in the cerebral arteries are distributed heterogeneously among different races. Intracranial carotid lesions are reported to be more common than extracranial carotid lesions among Japanese people, which is in sharp contrast to the pattern of cerebral atherosclerosis in whites. However, several Japanese clinicians have the impression, which has yet to be clinically proven, that extracranial carotid diseases are recently increasing in number.

METHODS

One hundred twenty-one patients who developed ischemic stroke and underwent angiography were examined in the study. Seventy were admitted to our clinic from 1963 to 1965 (early group); the remaining 51 patients were seen from 1989 to 1993 (recent group). Angiographic findings and vascular risk factors were compared between the two groups.

RESULTS

Severe atherosclerotic lesions of the extracranial internal carotid arteries increased significantly during the ensuing 24 years between the end of the first period until the beginning of the second period (from 1965 to 1989), whereas lesions in the intracranial carotid system were similar between the two groups. Severe atherosclerosis in the extracranial internal carotid artery was more frequent in patients with diabetes mellitus, which proved to be the only risk factor that showed a temporal increase.

CONCLUSIONS

The proportion of severe atherosclerosis in Japanese patients with brain ischemia has been increasing in the extracranial internal carotid artery, while that in the intracranial carotid system remains unchanged. Such a temporal change may be the result, at least in part, of an increase in the prevalence of diabetes mellitus.

Drug control of reverse cholesterol transport

Reverse cholesterol transport identifies a series of metabolic events resulting in the transport of excess cholesterol from peripheral tissues to the liver. High-density lipoproteins (HDL) are the vehicle of cholesterol in this reverse transport, a function believed to explain the inverse correlation between plasma HDL levels and atherosclerosis. An attempt to stimulate, by the use of drugs, this transport process may hold promise in the prevention and treatment of arterial disease. Among the agents affecting lipoprotein metabolism, only probucol exerts significant effects on reverse cholesterol transport, by stimulating the activity of the cholesteryl ester transfer protein and, consequently, altering HDL subfraction composition/distribution. Another approach to the stimulation of reverse cholesterol transport consists of raising plasma HDL levels; studies in animals, either by exogenous supplementation or by endogenous overexpression, have shown a consistent benefit in terms of atherosclerosis regression and/or non-progression. Thus, it is time to consider different future treatments of atherosclerosis, combining the classical lipid-lowering treatments with innovative methods to promote cholesterol removal from the arterial wall.

Silent cerebral infarction as a form of hypertensive target organ damage in the brain

The incidence, number, size, and location of silent cerebral infarction on 0.1 T magnetic resonance imaging was investigated in 66 hypertensive patients (63 +/- 9 years old; mean +/- SD) and 42 age-matched normotensive subjects (61 +/- 9 years old) to determine the clinical significance of hypertension in silent cerebral infarction. Cerebrovascular risk factors and the severity of hypertensive changes in other major target organs were also investigated. The incidence of silent infarction in hypertensive patients (47%) tended to be higher than that of normotensive subjects (33%) and increased significantly with advancing age. In hypertensive patients, a significantly higher incidence of silent lesions was noted in patients with hypertensive changes in major target organs (72-73% in patients with organ involvement versus 33-39% in those without). The average number of lesions in hypertensive patients was significantly higher than that in normotensive subjects (6.0 versus 2.1), and the lesions in the hypertensive patients were more frequently detected in the brain areas supplied by perforating arteries than those in normotensive subjects (47% versus 24%). These results clearly demonstrate that silent cerebral infarction is frequently seen in older hypertensive patients, especially when moderate hypertensive changes are noted in major target organs, and suggest that hypertensive arterial changes play a crucial role in the occurrence of silent infarction.

Evaluation of morphological changes of the atherosclerotic aorta by enhanced computed tomography

Enhanced and non-enhanced computed tomography (CT) were performed in 405 subjects (222 men; 183 women; mean age 57 years). Intimal atherosclerotic changes of the aorta were quantified by enhanced CT, revealing the atheromatous intima to be projecting and thick-walled, while non-enhanced CT demonstrated aortic calcification. We measured the degree of aortic intimal changes at various segments of the aorta. In 224 cases, CT was performed from the aortic root to the bifurcation of the abdominal aorta. Intimal changes were found predominantly at the aortic arch, the middle descending thoracic and the infrarenal abdominal aorta. As for the intimal changes, aortic calcification and aortic pulse wave velocity were significant atherosclerotic characteristics. The aortic diameter did not show a significant association with intimal change. Among the various atherosclerotic risk factors, intimal change was significantly associated with age, systolic blood pressure, serum total cholesterol and diabetes mellitus, whereas gender, diastolic blood pressure, relative weight and cigarette use were not significantly related. For coronary artery disease and arteriosclerosis obliterans, aortic intimal changes constituted a significant atherosclerotic feature. In cerebrovascular disease, however, aortic intimal change did not play a significant role.

Effect of aging on contractile response to KCl, norepinephrine and 5-hydroxytryptamine in isolated human basilar artery

1. We investigated the effect of aging on contractile response in human basilar artery. 2. The maximal contraction caused by KCl, norepinephrine and 5-hydroxytryptamine decreased with age. 3. ED50 value for norepinephrine or 5-hydroxytryptamine did not correlate with age. 4. These results suggest that the decrease in contractile response is due to nonspecific changes in the medial structure of the artery.

Experimental cerebral atherosclerosis in the rabbit. Scanning electron microscopic study of the initial lesion site

The development and initial lesion sites of cerebral atherosclerosis were studied in hypertensive rabbits fed 0.5 g/day cholesterol in their diet. The earliest lesions developed at remarkably localized areas of the basilar artery-posterior cerebral artery Y-bifurcation (area A) and vertebral arteries-basilar artery confluence (area B). These findings were obtained from a thorough scanning electron microscopic survey of the dorsal surface of the cerebral artery segment covering from the vertebral arteries to the posterior cerebral arteries. By light microscopy intimal lesions were mainly composed of accumulations of foam cells and smooth muscle cells. Electron microscopically foam cells accumulated in the intima resembled those of a monocyte-macrophage lineage. Early lesions involving only a few endothelial cells with adherent leukocytes occurred at the dividing and confluent portions of the endothelial arrays formed in areas A and B, respectively. The results indicate that hypertension coupled with hypercholesterolemia induces atherosclerosis in particular vulnerable regions of the cerebral arteries.

Cerebral blood flow and metabolism in normotensive and hypertensive patients with transient neurologic deficits

We used positron emission tomography to examine retrospectively the effects of blood pressure on regional cerebral blood flow and oxygen metabolism in seven normotensive and eight hypertensive patients with a history of transient neurologic deficits. In the hypertensive patients, a decrease in regional cerebral blood flow was closely related to blood pressure; these changes were most pronounced in the supratentorial structures, especially the striatum and thalamus. In contrast, the regional cerebral metabolic rate for oxygen was less related to blood pressure. Consequently, the regional oxygen extraction fraction was increased in the hypertensive patients, while regional cerebral blood volume and the regional cerebral blood flow volume ratio were unchanged. Multivariate regression analysis confirmed that hypertension was an independent factor affecting regional cerebral blood flow. The analysis also disclosed that age, sex, hematocrit, smoking, and PaCO2 affected regional cerebral blood flow. These findings suggest that the hemodynamic reserve in hypertensive individuals is reduced, which may predispose them to cerebral ischemia and perhaps stroke, even during small decreases in cerebral perfusion pressure.

A nation-wide study of atherosclerosis in infants, children and young adults in Japan

This paper reports the results of a nation-wide cooperative study of atherosclerosis in young, first generation Japanese with ages ranging from 1 month to 39 years, who were autopsied between 1978 and 1982 in hospitals distributed over the entire archipelago of Japan. Atherosclerotic lesions in 2320 aortas, 1620 coronary arteries and 344 cerebral arteries were classified into fatty streaks, fibrous plaques and complicated lesions and were then quantificated with the point-counting method. Atherosclerosis of aortas, coronary arteries and cerebral arteries, determined by surface involvement (SI) of atherosclerotic lesions and atherosclerotic index (AI), increased with age; the severest were seen in aortas, and then, with decreasing severity, in the coronary and cerebral arteries. Fatty streaks preceded the other lesions and accounted for the largest portion of the lesions in aortas and coronary arteries. Fibrous plaques and complicated lesions developed in the later decades of life. The patients with collagen diseases had a greater severity of aortic atherosclerosis in the 2nd and 3rd decades of life, than those without such disorders. Correlation of antemortem clinical data with SI and AI of each artery were analyzed, using simple correlation analysis and multiple regression analysis. Age, serum cholesterol and blood pressure were significantly and positively correlated with SI and AI of aortas and coronary arteries. Serum cholesterol was more strongly correlated with the extent of fatty streaks than was mean blood pressure and vice versa with that of fibrous plaques. Atherosclerosis of cerebral arteries, however, showed a significant correlation only with the factor of mean blood pressure. Therefore the susceptibility to risk factors varies with the artery in cases of early lesions of atherosclerosis in young Japanese.

A prospective study of cerebral artery atherosclerosis

Atherosclerosis in the circle of Willis and its major branches was studied prospectively in 198 men in the Honolulu Heart Program who were free of cardiovascular disease at the entry examination. The level of atherosclerosis was greater in the large arteries of the circle of Willis than in the small arteries, and autopsy-verified cerebral infarction was strongly associated with increasing severity of atherosclerosis in both. Analyses of the association of atherosclerosis scores with biologic and lifestyle characteristics measured at entry into the study indicated that atherosclerosis in the large arteries was consistently related to age, diastolic blood pressure, serum cholesterol, and height (inversely). Weak trends of association were also found with increasing serum glucose concentration, increasing cigarette use, and decreasing alcohol intake. Atherosclerosis scores in the small arteries were associated with diastolic blood pressure and serum triglyceride concentration. Analysis of dietary intake indicated that atherosclerosis scores were higher for men who reported low intakes of fat and animal protein and high intakes of vegetable protein and total carbohydrates. These patterns were consistent with similar findings on the incidence of clinical stroke in this cohort. Age-adjusted and -specific atherosclerosis scores from both the large and small arteries declined significantly during the period 1965-1983.

Individual variation in susceptibility to extracranial carotid atherosclerosis

Risk factors for coronary disease were assessed and noninvasive methods were used to quantitate the extent of extracranial carotid atherosclerosis in 382 patients free of cerebrovascular symptoms. The ages of the participants ranged from 27 to 80 years. There were 183 men and 199 women, 30 black and 352 white persons. All patients had heart disease symptoms and were hospitalized for coronary angiography. Correlation of risk factors with extent of extracranial carotid atherosclerosis in this series of patients undergoing coronary angiography uncovered individual variability in relationships between risk factors and carotid atherosclerosis that depended on coronary status. Risk factors for carotid atherosclerosis in patients with and without coronary disease differed. Age and hypertension were independently related to carotid atherosclerosis in patients with, as well as those without, coronary disease. However, other risk factors were related to carotid atherosclerosis in only one group or the other. Risk factors correlated strongly with carotid atherosclerosis in patients with coronary disease (r2 = 0.41) but poorly in those with no coronary disease (r2 = 0.21). Certain risk factors (age, pack years of smoking, left ventricular hypertrophy) related differently to the extent of carotid atherosclerosis in patients with, than in those without, coronary disease. Clarification of the role of coronary status in the carotid atherosclerosis response to risk factors may partly explain the results of certain population-based studies that have related race, gender, and other risk factors to carotid atherosclerosis.(ABSTRACT TRUNCATED AT 250 WORDS)

Relation between blood lipids, lipoproteins, and cerebrovascular atherosclerosis. A review

Although blood lipids and lipoproteins are strongly related to coronary atherosclerosis, their association with cerebrovascular atherosclerosis is less clear. A review of more than 20 publications in which a relation was sought between plasma lipid and lipoprotein concentrations and cerebrovascular atherosclerosis leads to the general conclusion that such a relation exists and that it is stronger in older than in younger individuals. A relation was found between blood lipids and/or lipoproteins and the extent and/or severity of cerebrovascular atherosclerosis in all but three of 26 reviewed studies. However, the specific nature of the relation is obscure because the various studies cannot easily be compared with one another. Interstudy variations in lipoprotein fraction analyzed, methodology for the analysis of lipids and lipoproteins, arterial segment examined, population sampled, control selection in case-control studies, statistical analytic approach taken, and methodology for the assessment of arterial disease preclude pooled analyses. There is a clear need for further evaluation of this relation using standardized and up-to-date methodologies both for analyses of lipids and lipoproteins and for assessment of cerebrovascular disease in symptom-free volunteers as well as in symptomatic patients.

Serum lipids and fatty acids in ischemic strokes

Lipid analysis of different constituents in the blood of patients with stroke revealed that an increased level of total serum cholesterol was infrequently (that of triglycerides more frequently) associated with stroke in middle-aged men, whereas the high-density lipoprotein cholesterol content was low in all but young patients with stroke. High contents of cholestanol and low contents of n-6 polyunsaturated fatty acids predict the development of stroke in middle-aged men and are found in both middle-aged men with stroke and elderly patients with multi-infarct dementia. Young patients with unexpected stroke had normal serum sterol, triglyceride, and fatty acid contents but markedly reduced arachidonic acid levels in the platelets, a change that was normalized by treatment with aspirin. The results emphasize that the etiopathogenesis of ischemic brain damage may vary markedly from one age group to another.

Italian multicenter study of reversible cerebral ischemic attacks. Part 5. Risk factors and cerebral atherosclerosis

As part of a prospective study, the influence of several premorbid and environmental factors on the presence, extent and severity of cerebral vessel atherosclerosis was studied in 462 patients with clinical diagnosis of RIA who underwent cerebral angiography. The extent and severity of atherosclerosis of the cerebral vessels was quantified using extracranial and intracranial cerebrovascular scores (ECS, ICS) based on the number and severity of the lesions in 11 extracranial and 21 intracranial arterial segments. Results of univariate and multivariate analyses indicate that the presence of atherosclerotic changes of cerebral vessels, as shown by angiography, was strongly related with age in both sexes. The lesions were more frequent in males, in particular under age 55. Elevated cholesterol was associated with a higher incidence of atherosclerotic lesions. Smoking was associated with a higher incidence of extracranial lesions. Age, smoking and history of hypertension were the best predictors of the extent and severity of cerebral vessel atherosclerosis.

Middle cerebral artery stenosis--a neglected problem?

Transcranial Doppler ultrasonography has great potential for clinical investigations that evaluate flow through the middle cerebral artery in health and disease. This technique will help to elucidate the syndromes of middle cerebral artery stenosis and occlusion, which have been overshadowed by the syndromes of internal carotid artery disease in the past.

Association of atherosclerosis with increased atrophy of brain matter in the elderly

The association of atherosclerosis with brain atrophy was studied in 101 subjects (75 men and 26 women) using computed tomography (CT). A calcification index (CI) was calculated as an indicator of atherosclerosis in the abdominal aorta: the calcified portion along the entire circumference of the abdominal aorta X 80. Both the cerebrospinal fluid (CSF) space volume and the volume percentage of the CSF space to the cranial cavity [brain atrophy index (BAI)] were calculated as indicators of brain atrophy. The CSF space volume increased with increasing age after the 70s. The BAI increased with increasing age after the 60s. Both the CSF space volume and the BAI in the 70s were 1.8 times those in the 40s. The CI increased with increasing age after the 50s very rapidly, and the CI in the 70s was 54 times that in the 40s. Both the CSF space volume and the BAI were greater in atherosclerotic (CI greater than or equal to 3.0) than in nonatherosclerotic (CI less than 3.0) subjects in the 60s and the 70s.

Cerebrovascular diseases and their underlying vascular lesions in Hisayama, Japan--a pathological study of autopsy cases

Frequency of cerebrovascular diseases (CVD) and their underlying vascular lesions were analyzed in 724 autopsy cases, aged 40 years and over, in the community of Hisayama, Japan during the period 1961 to 1981. Cerebral infarction (CI) was more frequently found at autopsy than cerebral hemorrhage (CH) with a ratio of infarction and hemorrhage of 4.4. Small CI occupied 75.7% of the cases with CI. The cases with any type of CVD showed more severe atherosclerosis of the major cerebral arteries than did those without CI or CH. Cerebral atherosclerosis of those with large and medium CI was the greatest, and with decreasing severity in those with small CI and with CH sequentially. Fibrinoid necrosis of the intracerebral small arteries was frequently found in cases with hypertension and particularly associated with CH. The decline in frequency of CH was confirmed; however, changes in frequency of CI were not evident. Fibrinoid necrosis was also reduced, although the severity of cerebral atherosclerosis showed no definite change. The decline of CH seemed to be ascribed to the reduction of fibrinoid necrosis of the intracerebral small arteries.