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Biomedical subjects

F M Yatsu

Publications and source records attributed to F M Yatsu.

At least 37 records · Page 2Linked to original sources
PubMed1989

Atherosclerosis: current concepts on pathogenesis and interventional therapies.

Atherosclerosis, the primary pathological condition accounting for most stroke syndromes, has been the intense focus of epidemiological, basic, and clinical investigations. Since these studies have direct bearing on the prevention of atherothrombotic brain infarction, this review emphasizes those advances in treatment resulting from their findings. The two most prominent theories on the pathogenesis of atherosclerosis relate to aberrations in lipoprotein metabolism and to enhanced proliferation of smooth muscle cells; likely, the theories are complementary. As a practical guideline for preventive therapy, the importance of using the total cholesterol level is stressed, although finer distinctions must rely on the low-density and high-density lipoprotein concentrations and their normalization. Since prevention of stroke may ultimately be its most effective therapy, consideration of cholesterol level, akin to strategies for preventing coronary heart disease, and efforts to avert platelet adhesion or aggregation and coagulation are warranted.

Arteriosclerosis↗
PubMed1989

Prediction of carotid stenosis progression by lipid and hematologic measurements.

We followed 19 men and 19 women with asymptomatic carotid stenosis up to 30 months to determine whether hematologic or lipid abnormalities could identify those individuals developing progressing carotid atherosclerosis (defined as an increase in mean percent stenosis greater than or equal to 19% or an increase in a single region of greater than or equal to 23%) on B-mode carotid ultrasonography performed at 2- to 6-month intervals. Our patients demonstrated increased beta-thromboglobulin, platelet factor 4, and fibrinogen compared with age-matched controls. Eight patients developed progression of carotid stenosis, and this group had higher baseline low-density lipoprotein (LDL) and fibrinogen than the 30 nonprogressing patients. Multiple regression analyses of age, sex, smoking, coronary artery disease, peripheral vascular disease, diabetes, hypertension, and baseline high-density lipoprotein (HDL), HDL2, HDL3, LDL, beta-thromboglobulin, platelet factor 4, and fibrinogen identified coronary artery disease and elevated LDL and fibrinogen as the only independent variables significantly associated with the progressing group. We conclude that, in patients with carotid atherosclerosis, a combination of coronary artery disease and elevated LDL and fibrinogen will predict with 88% accuracy whether the patient will have progressing carotid stenosis.

Aged↗
PubMed1988

Pentoxifylline in acute nonhemorrhagic stroke. A randomized, placebo-controlled double-blind trial.

The efficacy and safety of pentoxifylline were assessed in 297 adult patients with ischemic stroke in a multicenter, double-blind, randomized and placebo-controlled trial. Treatment was started within 12 hours after the stroke onset. Study medication was administered intravenously continuously (16 mg/kg/day, maximum 1,200 mg/day) for 3 days and per os (400 mg t.i.d.) for the remainder of 28 days. Demographic data were comparable, and functional impairment and mortality (pentoxifylline 12%, placebo 10%) were not different between the two groups. Neurologic deficit scores improved from baseline admission scores during the 4-week study in both groups but did not differ between groups at admission or throughout the study except during the first few days when the consciousness level (Days 1 and 2), motor function (Days 1 and 2), cranial nerve function (Days 1-4), and total neurologic deficit scores (Days 1 and 2) were better in the pentoxifylline group than in the placebo group, especially in a subset of patients with severe deficits at admission. Laboratory values and side effects were also comparable between groups. Our study indicates that pentoxifylline can be given safely in patients with acute ischemic stroke. Although pharmacologic effects were present during the first few days, the clinical benefits were small and not sustained.

Acute Disease↗
PubMed1986

Thromboxane, prostacyclin, and leukotrienes in cerebral ischemia.

Our understanding of the biochemistry and biologic actions of AA metabolites has been greatly expanded in recent years. The discoveries of TXA2, PGI2, and LTs have fostered new concepts of the pathophysiology of cerebral ischemia. New approaches to treatment of ischemia include seeking an optimal dose of aspirin, developing drugs that selectively inhibit or antagonize TXA2 or LTs, and administering PGI2 or its analogues. Altering the dietary content of essential fatty acids for prophylaxis is also being studied. Though the results of this thrust are still preliminary, the exploration of these therapeutic strategies in cerebrovascular disorders based on further understanding of the pathophysiologic roles of TXA2, PGI2, LTs and probably other AA metabolites is anticipated with some optimism.

Blood Platelets↗
PubMed1985

Enhancement of cholesteryl ester metabolism in cultured human monocyte-derived macrophages by verapamil.

The effect of the Ca2+ entry blocker, verapamil, on the biosynthesis of cholesterol and the metabolism of low-density lipoprotein (LDL) was studied in cultured human monocyte-derived macrophages. Addition of verapamil (50 microM) of monocyte-derived macrophages enhanced 125I-LDL and 125I-labelled acetyl-LDL binding and internalization, and increased [2-14C]acetate incorporation into cholesterol. Since higher levels of LDL and modified lipoproteins may be implicated in atherogenesis, the more efficient processing of these lipoproteins by monocyte-derived macrophages in the presence of Ca2+ blocker warrants further assessment for its potential as an antiatherogenic agent.

Cholesterol↗
PubMed1984

Cholesteryl ester hydrolase activity in mononuclear cells from patients with type II hypercholesterolemia.

Cholesteryl ester hydrolase (CEH) activity was measured in freshly isolated mononuclear cells from patients with primary Type II hypercholesterolemia, heterozygous familial hypercholesterolemia (FH) and familial combined hyperlipidemia (CFH). CEH activity was significantly lower in mononuclear cells from Type II patients than in cells from matched normolipidemic individuals. Moreover, the reduced CEH activity in cells from the hypercholesterolemic patients was accompanied by significant accumulation of cholesteryl ester. This pattern of reduced CEH activity and cholesteryl ester accumulation was identical for cells from both the FH and CFH patients. Since low density lipoprotein (LDL) cholesterol concentrations were higher in the Type II patients, we incubated mononuclear cells from normolipidemic individuals with high concentrations of LDL-cholesterol (greater than 150 mg/dl). Under these conditions CEH activity was significantly decreased, cholesteryl ester content increased, and cholesterol linoleate, in particular, accumulated. These data suggest that the intracellular accumulation of cholesteryl esters is determined in part by the extracellular concentrations of LDL-cholesterol and by the activity of CEH within the cells.

Carboxylic Ester Hydrolases↗
PubMed1984

Prostacyclin infusion in acute cerebral infarction.

We gave prostacyclin infusions to seven patients with acute cerebral infarction. Patients without CT evidence of infarction improved, but those who already had hypodensities on CT did not benefit. Increased platelet activity, measured by plasma beta-thromboglobulin, decreased significantly (p less than 0.01) during prostacyclin administration to normal levels, but rose again after the infusion. These results indicate that prostacyclin can be given safely in doses adequate to suppress platelet function. Our findings encouraged us to proceed with a controlled trial of its clinical efficacy.

Acute Disease↗
PubMed1983

Herpes zoster ophthalmicus and delayed ipsilateral cerebral infarction.

We studied five patients who had acute cerebral infarctions 5 weeks to 6 months after herpes zoster ophthalmicus (HZO). All had infarcts of the cerebral hemisphere ipsilateral to the HZO, and one also had a cerebellar infarct. Cerebral arteriography in one patient disclosed narrowing of the middle cerebral artery, occlusion of the anterior cerebral artery ipsilateral to the HZO and narrowing of the opposite anterior cerebral artery. In another case, arteriography revealed occlusion of the distal internal carotid artery on the side of the HZO.

Adolescent↗
PubMed1983

Pharmacologic protection against ischemic brain damage.

Pharmacologic protection should be used cautiously. The author reviews its rationale, use, and recommendations in three clinical conditions associated with ischemic brain damage: stroke, cardiac arrest, and head trauma.

Adult↗