The purpose of this study is to evaluate usefulness of X-ray CT, MRI, 2D-echo, and DSA in detecting arteriosclerotic changes. Plain and enhanced CT scans were performed on 413 subjects to evaluate aortic sclerosis. CT revealed aortic wall calcification, atheromatous projection of the intima, and thickened aortic walls. These findings appeared frequently with increasing age, and the ratio of atherosclerotic changes to the circumference of the aorta increased in the patients with cerebrovascular disease, coronary heart disease, hypertension, and diabetes. In 179 patients, plain CT and coronary angiography were performed. Sensitivity, specificity, and predictive value for estimating coronary stenosis by CT-detected coronary calcification were 79% 78%., and 89%, respectively.
MRI also revealed atherosclerotic changes. In 408 subjects MRI was performed using a spinecho method. Although atheromatous intimal changes were found in 4.8% of normal subjects, these findings were demonstrated in 46% of the patients with diabetes, in 32% of patients with hypertension, and in 20% of patients with ischemic heart disease. 2D-echo was useful in detecting atheromatous intimal changes in the carotid artery. DSA was also useful for detecting stenosis of the peripheral arteries of median size.
In conclusion these imaging methods can play an important role in diagnosing arteriosclerosis.

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The non-invasive quantitative determination of atherosclerosis is required in the treatment of risk factors. We evaluated the wall thickening and stenosis rate (ASI), the calcification rate (ACI) and the wall thickening and calcification stenosis rate (SCI) of the lower abdominal aorta calculated by the 12 sector method from simple or enhanced computed tomography.
The intra-observer variation of the calculation of ASI was 5.7% and that of ACI was 2.4%. In 9 patients who underwent an autopsy examination, ACI was significantly correlated with the rate of the calcification dimension to the whole objective area of the abdominal aorta (r=0.856, p<0.01). However, there were no correlations between ASI and the surface involvement or the atherosclerotic index obtained by the point-counting method of the autopsy materials. In the analysis of 40 patients with atherosclerotic vascular diseases, ASI and ACI were also highly correlated with the percentage volume of the arterial wall in relation to the whole volume of the observed artery (r=0.852, p<0.0001) and also the percentage calcification volume (r=0.913, p<0.0001) calculated by the computed method, respectively.
The percentage of atherosclerotic vascular diseases increased in the group of both high ASI (over 10%) and high ACI (over 20%). We used SCI as a reliable index when the progression and regression of atherosclerosis was considered. Among patients of hypercholesterolemia consisting of 15 with familial hypercholesterolemia (FH) and 6 non-FH patients, the change of SCI (d-SCI) was significantly correlated with the change of total cholesterol concentration (d-TC) after the treatment (r=0.466, p<0.05) and the change of the right Achilles' tendon thickening (d-ATT) was also correlated with d-TC (r=0.634, p<0.005). However, no correlation between d-SCI and d-ATT was observed.
In conclusion, CT indices of atherosclerosis were useful as a noninvasive quantitative diagnostic method and we were able to use them to assess the progression and regression of atherosclerosis.

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The stimulation of reverse cholesterol transport (RCT) is important for the prevension and regression of atherosclerosis. The high concentration of plasma HDL and high activity of LCAT seem to stimulate RCT. Esterified cholesterol (EC), produced by LCAT reaction in HDL is transfered directly to the liverr or to VLDL, IDL and LDL by lipid transfer protein (LTP). It is not well defined whether or not the high activity of LTP stimulates RCT. The activities of LCAT and LTP in CHD were assayed first in order to determine their role in atherosclerosis, and the effects of probucol and pravastatin on their activities were estimated for studying the effects of those drugs on reverse cholesterol transport.
Plasma TC, TG and apo B levels were high, and HDL-C and apo AI levels were low in CHD patients as is well known. LCAT activities were significantly higher in CHD than in control subjects but were slightly lower in CHD patients without hyperlipoproteinemia. The activities of LTP were 84±44units (mean±SD; the value of pooled control plasma: 100units) in control subjects and 118±54units in CHD patients. LTP activities were significantly higher in CHD than in control subjects (P<0.05). Plasma lipids level did not affect the correlation.
Probucol reduced plasma TC by 19% and HDL-C by 15% significantly by 12 weeks of treatment, Pravastatin significantly reduced plasma TC by 15% and increased plasma HDL-C by 9% without statistical significance. LCAT activities were 105±18n mol/ml/hr and 87±21n mol/ml/ hr before and after 12 weeks of probucol treatment and were 104±16n mol/ml/hr and 90±20n mol/ ml/hr before and after 12 weeks of pravastatin treatment. The decreases of LCAT activity by probucol and pravastatin were not statistically significant. Probucol significantly increased LTP activity by 26%. Pravastatin tended to decrease LTP activity by 46% without statistical significance.
LCAT activity is affected by plasma lipids levels. Therefore, LCAT activity must be low in CHD when plasma lipids levels are matched. As determined from the results in CHD, the high plasma HDL levels, high LCAT activity and low LTP activity stimulate RCT and prevent atherosclerosis. Probucol reduced plasma HDL levels and increased LTP activity significantly and tended to decrease LCAT activity. Therefore, probucol may inhibit RCT. Pravastatin tended to increase plasma HDL levels and to decrease LTP activity, hence, pravastatin may stimulate RCT. The effects not only on the metabolism of atherogenic lipoproteins but also on RCT must be carefully investigated for the treatment of hyperlipoproteinemia.

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Maximum blood flow velocity (BVmax), mean flow volume (BF), mean diameter (D), and diameter excursion (ΔD) of the common carotid artery were measured by an ultrasonic quantitative flow measurement system. Stiffness parameter β, representing one of the mechanical properties of the vessel, was calculated from measurement of blood pressure, D and ΔD. BVmax and BF were parameters of hemodynamics; D and β were parameters of vessel wall properties. BVmax and BF decreased with aging; D and β increased with aging. In patients with diabetes mellites, hypercholestemia and hypertension, the change in each parameter was found to be significantly greater than in normal subjects. In subjects with cerebral infarction, BF on the diseased side decreased significantly compared with that on the healthy side. BF on the healthy side was almost equal in normal subjects, but β valves on both sides in cerebral infarction cases were higher compared with the β valves in normal subjects. Reliability of BF and β which had been measured in living subjects (n=60) was supported by postmortum pathological findings. BF valves correlated inversely with the stenosis degrees of the carotid and cerebral arteries (r=-0.69, p<0.0001). In cases of BF≤6.4 ml/sec, all such cases had stenosis<50 %. β and common carotid arteriosclerosis had a correlation coefficient of 0.68 (p<0.01). β revealed the degree of common carotid arteriosclerosis present. The maximum limit of β in healthy subjects was 13, but β did not correlate with the stenosis degree of the carotid and cerebral arteries (r=0.18). From these results, we had to measure both BF and β, and the case with BF≤6.4ml/sec or β≥13 was diagnosed as arteriosclerosis.
We have succeeded in quantitatively measuring basal cerebral artery blood flow velocity using transcranial color Doppler tomography (TCDT). TCDT at 2.5MHz was able to recognize the middle cerebral artery (MCA) as a colored blood flow signal in sector images. In determining the angle between the ultrasonic beam and M1 portion of the MCA, a quantitative phasic velocity sonogram was recorded using real-time pulse Doppler. Maximum and mean blood flow velocities were calculated from the sonogram. The inverse correlation between BVmax and age was close, the correlation ratio being -0.64 (p<0.01). In the arteriosclerosis group, the BVmax was significnatly lower than in the same decade in the healh y group. The TCDT method was very useful in diagnosing cerebral arteriosclerosis noninvasively and directly.

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To ascertain the prevalence of abnormal lipid values in an urban population, serum total cholesterol (TC), triglyceride (TG), high-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol (LDL-C calculated by Friedewald's equation) were determined in 48, 167 males and 13, 141 females over the age of 20 years in a general health examination program.
The results of this study demonstrated that this population showed a high number of people with TC values exceeding 200mg/dl, TG values exceeding 150mg/dl, HDL-C values less than 40mg/dl, and LDL-C values exceeding 150mg/dl—these values being the threshold at which medical therapy is deemed necessary. They further indicate from the standpoint of public health an urgent need to develop preventive measures against hyperlipidemia.

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Increases in serum VLDL- and LDL-cholesterol levels and hepatic VLDL-cholesterol secretion were observed in animals fed a diet enriched with 0.1 cholesterol in comparison with control animals.
Addition of dietary palmitic acid accelerated the effect of cholesterol on serum VLDL- and LDL-cholesterol levels and hepatic VLDL-cholesterol secretion.
Dietary linoleic acid accelerated the effect of cholesterol on hepatic VLDL-cholesterol secretion and diminished the effect of cholesterol on the serum LDL-cholesterol level.
Hepatic LDL-receptor activity was suppressed by a control diet containing 0.05% cholesterol, and no further suppression was induced by a diet enriched with 0.1% cholesterol with or without 5% palmitic acid. However, dietary linoleic acid diminished the effect of cholesterol on the suppression of hepatic LDL-receptor activity.
These results suggest that by accelerating hepatic VLDL-cholesterol secretion, dietary palmitic acid augments the effect of cholesterol in elevating the serum LDL-cholesterol level and that dietary linoleic acid diminishes the elevation of serum LDL-cholesterol level by cholesterol by preventing the suppression of hepatic LDL-receptor activity induced by cholesterol. However, the precise mechanism of dietary fatty acids on the regulation of lipoprotein metabolism was not clear.

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The propositus was a 43-year-old Japanese male with a plasma total-chol level of 252mg/dl and a HDL chol level of 169mg/dl. His brother also had a markedly higher HDL-chol level of 149mg/dl. His mother, sister and 3 children had higher HDL-chol levels of 75-91mg/dl. Thus, the subject and his brother were diagnosed as homozygous familial hyperalphalipoproteinemia (FHALP), whereas his mother, sister and 3 children were diagnosed as heterozygous FHALP. None had any clinical signs of atherosclerosis. The subject and his brother (homozygous FHALP) also showed markedly higher levels of plasma apo E (>16mg/dl) and AI (>190mg/dl), and showed a complete deficiency of Cholesteryl ester transfer activity (0.0% transfer/5μl/18hr and 0.3% transfer/5μl/18hr, respectively). It is concluded that this case is a homozygous FHALP caused by a complete deficiency of Cholesteryl ester transfer activity.

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To analyze the characteristics of lipid metabolism in ischemic heart disease, lipoprotein composition, lipoprotein particle size, and activity of enzymes related to lipid metabolism (lecithincholesterol-acyltransferase (LCAT), lipoprotein lipase (LPL), hepatic triglyceride lipase (HTGL)) were studied and compared in patients with myocardial infarction and healthy controls. 24 inpatients with acute myocardial infraction (AMI), 22 outpatients with myocardial infarction in the past (OMI), and 22 healthy controls (C) were analyzed in the study. There was no significant difference in plasma lipid and lipoprotein cholesterol levels among the three groups. Analysis of the lipoprotein composition ratio (as the percentage composition in each lipoprotein fraction LDL and HDL) showed significantly higher HDL-TG% in the OMI group than in C group. HDL particle size was significantly larger in the AMI group than in the C group. LCAT activity was significantly lower in the AMI and OMI groups than in the C group. HTGL activity was lower in the AMI group than in the C group, while LPL activity showed no significant differences among the groups. It is well known that HTGL plays a fundamental role in the delipidation of HDL particle size (changing HDL2 to HDL3). Consequently, low HTGL activity in AMI patients may explain the high HDL-TG% composition and large HDL particle size in this group when compared to the corresponding composition and particle size in the control subjects. On the other hand, low LCAT activity in patients with myocardial infarction is more difficult to understand in light of its primary function. The activity of lipid transfer protein, another important component of lipid exchange reaction, must be analyzed together to elucidate better the mechanisms involved in the lipid metabolism in patients with ischemic heart disease.

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Atherosclerosis is the most common cause of ischemic heart disease and cerebrovascular disorders. However, the mechanism of the development of atherosclerosis has not yet been fully elucidated. The object of the present study was to observe the differences in the architectural damage in the coronary and cerebral atherosclerosis regarding changes in the cellular and intercellular matrices of man. Both the intima, and media were studied. The left anterior-descending coronary arteries were obtained from 97 cases that had undergone an autopsy. Quantitative analyses were done for the following 3 parts of specimens: 1) Intima with a thickening in cases without atheroma, 2) Intima with a thickening of parts with no atheromatous changes in cases with atheroma, 3) Intima with atheromotous changes. In all materials, the number of smooth muscle cells (SMC), and the amount of elastin (EL), collagen (CL), glycosaminoglycans (GAGs) and PAS-positive materials (PAS) were estimated by using a microspectrophotometer.
The following histological differences were also observed in two arteries. In a coronary artery, the intimal thickening was diffuse and circumferential and some elastic fibers were estranged from the intimal elastic lamina; while in the cerebral artery, intimal thickening was localized in some portions and the internal elastic lamina remained thick while showing no destruction. With the progress of arterial sclerosis, the degenerated elastin, GAGS and CL (type I) increased both arteries. The PAS-positive material decreased in coronary arteries and increased in cerebral arteries, thereby suggesting the reduction of glycoproteins in the former and the production of CL (type V) in the latter. The connective tissues in the intima with the atheromatous changes was denser. in the cerebral arteries than in the coronary arteries.

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Rats tend to be resistant to atherosclerosis. Therefore it is rather more difficult to experimentally induce atherosclerosis in rats than in rabbits, pigs, monkeys or birds. We tried to experimentally induce atherosclerotic lesions in rat arteries over a short period. A 2-French balloon catheter was introduced into the rat's left carotid arteries from the iliac arteries and the endothelium was denuded. An atherogenic diet (2% Cholesterol, 0.4% Cholic-Na, 5% Lard, and 0.2% Propyltlziouracil) was provided for 14 days. After fasting overnight, the rats were sacrificed. Samples of the carotid arteries were taken for light and electron microscopy and the rest of the arteries were used to extract cholesterol and the DNA for a quantitative determination. We found that atherosclerotic lesions had formed in the carotid arteries of every examined rat. The induced atherosclerotic lesions significantly resembled human atherosclerosis from the following point of view; 1) observation of intense intimal thickening with a cholesteryl ester accumulation and, 2) the appearance of foam cells laded with lipids.

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Qualitative and quantitative techniques for the histochemical localization of cholesterol in the aorta were developed. It is based on the same principle as conventional enzymatic determination of total cholesterol in serum by the so-called diformazan stain method. The intimal fiat region of the 5th intercostal aorta were obtained from human adults upon autopsy. The aorta were fixed in 10% formalin and were frozen at -120° under liquid N₂ gas delivered through a special nozzle. The aortic slices were prepared using a glass knife and a JB-4 automicrotome. The sections were laid out on the glass slide and were exposed to overhead drops of 1% Triton ×-100 solution and were then stained using an enzymatic total cholesterol reagent (Nikon Shoji). The localization of the cholesterol was observed by microscope, after which 70 points of the percent of extinction in the aortic slices was measured by scanning using a microspectrometer set at a 535nm. To compare the present histochemical method with biochemical cholesterol determination, the same aortic samples were extracted by CHCl₃-MeOH (2:1). The total cholesterol in the aliquots was determined by an enzymatic method. Results by the two methods were similar. The advantages of the histochemical method for total cholesterol include direct deternlinatioll of cholesterol. An assay was also possible with observation of localization and distribution of total cholesterol.

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Diffuse intimal thickening (DIT) has appeared in human coronary arteries in infants. Eccentric intimal thickening (EIT) is raised from DIT, and may develop to atheromatous intimal thickening (plaque). In order to clarify histological changes according to the development from DIT to EIT or plaque, coronary arteries obtained from 95 male autopsy cases were histometrically and immunohistochemically investigated. Histometrival studies were carried out on the main trunk of the right coronary artery (segment 1: seg. 1) and the left descending artery (seg. 6). Thickness of the intima was measured in all cases. In cases over 30 years of age, volume fractions (Vfs) of smooth muscle cells (SMCs), foam cells, blood cells, collagen, elastic fibers, extracellular matrix (ECM) and atheroma in the intima and as well as the number and density of intimal SMCs were analyzed by a point counting method. Immunohistochemical studies were carried out on 12 cases for which postmortem time was less than 4 hrs. The thickness of DIT in both seg. 1 and 6 increased with age. Histometrically collagen fibers were the most major component in these segments, and the collagen Vf also increased with age. Vfs of SMCs, elastic fibers, and ECM decreased with age. The density of SMCs in the intima decreased rapidly in the fourth and fifth decades, and then reafter decreased more slowly. EIT in both seg. 1 and 6 also thickened with age, and the rate of increase was higher than that of DIT. Collagen Vf was the largest, and was most similar to DIT. Atheromas were more frequently seen in seg. 6. Although the number of SMCs in EIT was two times larger than that of DIT in each decade, the density of SMCs in EIT was lower than that of DIT. The density of SMCs in plaque was lower than that of EIT. In contrast, the collagen Vf was higher than that of EIT. In immunohistochernical studies, alot of anti-muscle or anti-macrophage positive foam cells were identified in plaques. Some of them were positively stained with anti-prolyl hydroxylase. The anti-prolyl hydroxylase positive cells were more in plaque than DIT. Anti-β lipoproteins and anti-collagen type I reacted more intensely in plaque than DIT. From these results, EIT could turn into plague because of the accumulation of collagen fibers, and lipid infiltration leading to atheroma formation. In conclusion, in the human coronary artery, EIT, DIT and plaque thickened mainly because of the accumulation of collagen fibers, not by SMCs proliferation, particularly after the fourth decade.

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Serum lipid and lipoprotein concentrations were measured in ninety-five noninsulin-dependent diabetic patients aged 30 to 65 years old with less than 8% glycosylated haemoglobin Alc and with less than 1.3mg/dl serum creatinine. Ninetyfive patients were divided into three groups by their urinary albumin excretion; proteinuria (=persistent microalbuminuria, n=19), microalbuminuria (=albumin excretion ≥1.8mg/dl, n=37), and normoalbuminuria (=albumin excretion<1.8mg/dl, n=39). Control subjects were fourteen healthy volunteers matched for age and BMI (Body Mass Index).
The results were as follows:
1) No significant differences were found in serum lipids and lipoproteins between diabetic patients with normoalbuminuria and contr. of subjects. Abnormalities of serum lipids and lipoproteins were found more in diabetic patients with persistent albuminuria than the other 3 groups.
2) Total cholesterol (TC), triglyceride (TG), low density Lipoprotein cholesterol (LDL-C), apolipoprotein (Apo) B, atherogenic index (AI), LDL-C/high density lipoprotein cholesterol (HDL-C) ratio, and Apo B/Apo A-I ratio in diabetic patients with microalbuminuria were significantly higher than in diabetic patients with normoalbuminuria. In addition, lower HDL-C concentrations were found in the microalbuminuria group than in the normoalbuminuria group.
All these results were consistently observed in diabetic men aged from 30 to 49 years old and in diabetic women aged from 50 to 65 years old.
We conclude that abnormalities of serum lipids and lipoproteins appear in noninsulin-dependent diabetic patients with microalbuminuria.

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Subjects were a total of 24 mature male Japanese white rabbits averaging 38 months of age comprising a healthy normal group of 8 rabbits, a sclerotic group of 9 rabbits, and a therapeutic group of 7 rabbits. For the latter 2 groups, arteriosclerosis was experimentally prepared by combining inhalation of N₂ gas, i. p. injection of noradrenalin, and oral administration of cholesterol (0.5g/day). The therapeutic group was also given Clinofibrate (200mg/day) simultaneously with the start of the above loading. 22 weeks later, all rabbits were sacrificed and the tissue was cut off from a proximal region of the left coronary anterior descending branch. The tissue was then embedded in parafin after 10%-formalin fixation, sliced to a thickness of 4μ by a JB4A Automicrotome, and specially stained for each of 5 arterioarchitectural components: smooth muscle cell (SMC); elastin (EL); collagen (CL); glycosaminoglycans (GAGs); and PAS positive material. The tissue was observed and determined histochemically by microspectrophotometer (MSP). The above coronary components for the sclerotic group showed a significant decrease in SMC and an increase in EL, CL, GAGs, and PAS positive material as compared with the healthy normal group. Compared with the sclerotic group, pathological hyperplasia of SMC and various other connective tissues in the clinofibrate group were inhibited. Overall estimation of the contents of these 5 components by principal-component analysis also revealed approximate characteristics of the therapeutic group to the healthy normal group, suggesting an inhibitory effect of clinofibrate on the progress of coronary arteriosclerosis.

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To search for the mechanisms involved in coronary artery spasm, alcohol provocation tests were performed in patients with variant angina (VA) whose histories suggested a close relationship between anginal attacks and alcohol ingestion. Plasma levels of ethanol, serotonin, catecholamines, prostanoids, and cyclic nucleotides were monitored before and after ingestion of alcohol.
We studied 8 male patients and 8 male control subjects. Four hundred milliliters of rice wine containing 17% ethanol was given to each of them in the evening (7:00-9:00 p.m.). Blood samples were taken every 3 hours to determine plasma levels of ethanol (ETOH), serotonin (SHT), adrenaline (Ad), noradrenaline (NA), thromboxane B₂ (TXB₂), 6-keto PGF_1α (6-Kp), cAMP and cGMP.
Four patients developed angina early in the morning of the next day(3:00-7:20 a.m.), when the plasma levels of ETON were null but increases in those of 5HT, TXB₂, and 6-Kp were noted.
Before and just after alcohol ingestion, plasma levels of 6-Kp in VA were significantly less than those of controls (p<0.05). Before the tune of attacks (3:00 a.m.), the plasma levels of 6-Kp in VA as well. as those of 5HT, Ad, NA, and cAMP did not show significant differences from those in controls.
However, plasma levels of cGMP in VA exhibited gradual decreases after alcohol ingestion to the levels which were significantly lower than those before alcohol ingestion (p<0.01), and also lower than those in the controls (p<0.05).
In summary, plasma levels of 6-keto PGF_1α in patients with variant angina were significantly lower than those of controls before alcohol ingestion. On the other hand, plasma levels of cGMP decreased after alcohol ingestion and showed significant differences between the patients and controls.
We concluded that decreased plasma levels of cGMP and 6-keto PGF_1α may be involved in enhanced arterial tone, which may be associated with induction of coronary artery spasm.

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