Geographic variation in declining ischemic heart disease mortality in the United States, 1968-1978. I. Rates and change, whites aged 35-74 years

Despite the well known geographic pattern for heart disease mortality, studies of the decline in ischemic heart disease have not provided a comprehensive examination of its spatial component. In this study, the authors computed and mapped mean rates and per cent change in ischemic heart disease mortality for whites aged 35-74 years, for the period of the Eighth Revision (1968-1978) of the International Classification of Diseases. Visual evidence of clustering and markedly different spatial patterns were found for mean rate and per cent change among the state economic areas of the United States.

The hypolipidemic activity of furoic Acid and furylacrylic Acid derivatives in rodents

2-Furoic acid, 3-furoic acid, 3,4-furan dicarboxylic acid and furyl-acrylic acid were evaluated for hypolipidemic activity in mice and rats. 2-Furoic acid was the most potent agent of the four tested, lowering serum cholesterol levels 41 % and serum triglyceride levels 56 % at 20 mg/kg/day in mice and serum cholesterol 50 % and serum triglyceride levels 42 % in rats. 2-Furoic acid effectively suppressed liver mitochondrial citrate exchange, ATP dependent citrate lyase, acetyl CoA synthetase, acyl CoA cholesterol acyl transferase, sn-glycerol-3-phosphate acyl transferase, phosphatidate phosphohydrolase and hepatic lipoprotein lipase enzymatic activities. Lipid levels after 16 days in mice were reduced in the liver. In the rat cholesterol content of the HDL fraction was elevated and lowered in the chylomicron fraction. 2-Furoic acid administration for 14 days resulted in a large portion of (3)H-cholesterol being excreted by the biliary route. The furoic acid derivatives appear to have promise as hypolipidemic agents and further studies on their ability to lower lipids are warranted.

Hypolipidemic activity of 6-amino-2-mercapto-5-methyl-pyrimidine-4-carboxylic acid and related derivatives in rodents

6-Amino-2-mercapto-5-methylpyrimidine-4-carboxylic acid proved to be a potent hypolipidemic agent in rodents at the low dose of 20 mg/kg/d. The agent effectively reduced the liver enzyme activities required for the synthesis of triglycerides and cholesterol. Lower lipid levels in tissue were observed in mice but not in rats. Preliminary studies indicate that the agent accelerated the excretion of cholesterol and its metabolites from the body. The agents lowered the low-density lipoprotein (LDL) cholesterol content and raised the high-density lipoprotein (HDL) cholesterol content. These changes in lipoprotein cholesterol content suggest that the agent may be helpful in protecting against coronary disease. The agent is more effective than the commercially available agent, i.e., clofibrate at 150 mg/kg/d.

Serum retinol and risk of subsequent cancer: extension of the Evans County, Georgia, study

A previous report from the Evans County, Ga., cohort correlated low base-line retinol levels in 1960-62 to an increased risk of cancer developing in the following 12-14 years. So that this inverse association could be retested, retinol determinations were performed on sera in 135 incident cancer cases, identified during a vital status follow-up in 1981, and in 237 controls matched by race, sex, age, and date of venipuncture. The serum was drawn during the second cohort examination between 1967 and 1969 and stored at -20 degrees C until analysis by high-pressure liquid chromatography in January 1982. Eligible for the study were patients whose initial cancer diagnosis was established more than 24 months after venipuncture. Base-line retinol levels of subsequent cancer cases and their matched controls were similar in the 4 race-sex groups. The risk of cancer at all sites associated with the lowest retinol quintile was similar to that associated with the highest quintile. In multivariate analysis, with control for age, cholesterol, body mass, smoking status, and social class, no significant relationship of serum retinol and case status was found. In summary, these data fail to confirm the strong dose-response relationship between baseline retinol levels and subsequent cancer reported in the previous study.

Bioelectric properties and ion flow across excised human bronchi

Bioelectric properties and ion transport of excised human segmental/subsegmental bronchi were measured in specimens from 40 patients. Transepithelial electric potential difference (PD), short-circuit current (Isc), and conductance (G), averaged 5.8 mV (lumen negative), 51 microA X cm-2, and 9 mS X cm-2, respectively. Na+ was absorbed from lumen to interstitium under open- and short-circuit conditions. Cl- flows were symmetrical under short-circuit conditions. Isc was abolished by 10(-4) M ouabain. Amiloride inhibited Isc (the concentration necessary to achieve 50% of the maximal effect = 7 X 10(-7) M) and abolished net Na+ transport. PD and Isc were not reduced to zero by amiloride because a net Cl- secretion was induced that reflected a reduction in Cl- flow in the absorptive direction (Jm----sCl-). Acetylcholine (10(-4) M) induced an electrically silent, matched flow of Na+ (1.7 mueq X cm-1 X h-1) and Cl- (1.9 mueq X cm-12 X h-1) toward the lumen. This response was blocked by atropine. Phenylephrine (10(-5) M) did not affect bioelectric properties or unidirectional ion flows, whereas isoproterenol (10(-5) M) induced a small increase in Isc (10%) without changing net ion flows significantly. We conclude that 1) Na+ absorption is the major active ion transport across excised human bronchi, 2) Na+ absorption is both amiloride and ouabain sensitive, 3) Cl- secretion can be induced by inhibition of the entry of luminal Na+ into the epithelia, and 4) cholinergic more than adrenergic agents modulate basal ion flow, probably by affecting gland output.

Relative ion permeability of normal and cystic fibrosis nasal epithelium

The raised transepithelial electric potential difference (PD) across respiratory epithelia in cystic fibrosis (CF) has suggested an abnormality in ion permeation. We characterized this abnormality further by measuring in the nasal epithelia of CF and normal subjects the concentration-PD relationship for amiloride, an inhibitor of cell Na+ permeability, and PD responses to superfusion with solutions of different composition. Amiloride was more efficacious in the CF subjects but the ED50 was not different from that of normals (approximately 2 X 10(-6) M). Na+ replacement by choline induced effects similar to those of amiloride, i.e. a greater depolarization in CF subjects. A 10-fold increase in the K+ concentration of the perfusate induced a small (less than 10 mV) depolarization in both subject populations. When Cl- in the perfusate was replaced by gluconate or SO2-(4) the nasal PD of normal subjects hyperpolarized (lumen became more negative) by approximately 35 mV. A significantly smaller response (less than 17 mV) was induced in CF homozygotes but not in heterozygotes (38 mV). The smaller response of CF subjects appears to reflect an absolute decrease in luminal surface Cl- permeability because pretreatment with amiloride did not increase the response to Cl- free solution (7 mV). Accordingly, three abnormalities (decreased Cl- permeability, raised PD, greater amiloride efficacy) have been identified in CF respiratory epithelia. Whereas "excessive" active Na+ transport can account for these abnormalities and the dessication of airway surface liquid, it is possible that a lower lumenal cell membrane Cl- permeability and inhibition of a potential path of Cl- secretion can also explain the observations.

Increased bioelectric potential difference across respiratory epithelia in cystic fibrosis

To investigate respiratory epithelial function in cystic fibrosis, we measured the transepithelial electrical potential difference across the upper and lower respiratory mucosa in patients with cystic fibrosis and control subjects. The nasal potential difference in the 24 patients with cystic fibrosis exceeded by more than 3 standard deviations the mean voltage in healthy controls, subjects with other diseases, and subjects heterozygous for cystic fibrosis. Potential differences in lower airways were measured in four patients and were significantly greater than in controls (P less than 0.05). Superfusion of the luminal surface with amiloride, an inhibitor of active sodium absorption, induced greater reductions in both nasal and airway potential difference in patients than in controls. We conclude that the increased respiratory-epithelial potential differences appear to be a specific abnormality in homozygotes for cystic fibrosis. The greater reduction in potential difference in response to amiloride suggests that absorption of excess salt and perhaps liquid from respiratory epithelial surfaces contributes to the pathogenesis of lung disease in cystic fibrosis.