Treatment of hypercholesterolemia with Secholex. A long-term clinical trial and comparison with cholestyramine

Quantitation of in vivo human folate metabolism

BACKGROUND

A quantitative understanding of human folate metabolism is needed.

OBJECTIVE

The objective was to quantify and interpret human folate metabolism as it might occur in vivo.

DESIGN

Adults (n = 13) received 0.5 nmol [(14)C]pteroylmonoglutamate (100 nCi radioactivity) plus 79.5 nmol pteroylmonoglutamate in water orally. (14)C was measured in plasma, erythrocytes, urine, and feces for >/=40 d. Kinetic modeling was used to analyze and interpret the data.

RESULTS

According to the data, the population was healthy and had a mean dietary folate intake of 1046 nmol/d, and the apparent dose absorption of (14)C was 79%. The model predictions showed that only 0.25% of plasma folate was destined for marrow, mean bile folate flux was 5351 nmol/d, and the digestibility of the mix (1046 + 5351 nmol/d) was 92%. About 33% of visceral pteroylmonoglutamate was converted to the polyglutamate form, most of the body folate was visceral (>99%), most of the visceral folate was pteroylpolyglutamate (>98%), total body folate was 225 micromol, and pteroylpolyglutamate synthesis, recycling, and catabolism were 1985, 1429, and 556 nmol/d, respectively. Mean residence times were 0.525 d as visceral pteroylmonoglutamate, 119 d as visceral pteroylpolyglutamate, 0.0086 d as plasma folate, and 0.1 d as gastrointestinal folate.

CONCLUSIONS

Across subjects, folate absorption, bile folate flux, and body folate stores were larger than prior estimates. Marrow folate uptake and pteroylpolyglutamate synthesis, recycling, and catabolism are saturable processes. Visceral pteroylpolyglutamate was an immediate precursor of plasma p-aminobenzoylglutamate. The model is a working hypothesis with derived features that are explicitly model-dependent. It successfully quantitated folate metabolism, encouraging further rigorous testing.

Biodegradable positively charged ion exchange beads: a novel biomaterial for enhancing soft tissue repair

Previous work in the area of vulnerary agents is extensive. One material of focus has been positively charged ion exchange beads, which have been shown to promote a variety of wound-healing responses in several models. The goal of this work was to improve upon the clinical utility of positively charged dextran beads by creating a biodegradable version that maintains the material's inherent efficacy. A chemical method consisting of a sodium periodate oxidation was used to create a degradable diethylaminoethanol crosslinked dextran bead. The ability of this process to create a degradable bead was verified in vitro and in vivo. Furthermore, efficacy was shown in a rat linear incision model for a variety of beads exhibiting different degradation rates. The results show that efficacy is maintained by a degradable bead, but there is a diminution of the magnitude of the response as the mass loss rate is increased. Efficacy also was investigated for a moderate but completely degrading bead material over time and dose. Wound breaking strength was evaluated at days 7, 10, 14, 21, and 28 for degradable beads at doses of 10 mg/mL and 50 mg/mL. Although little difference in efficacy was noted for the increased dose, statistically significant increases over control were seen at days 7, 10, and 14 for the 10 mg/mL dose and at days 10 and 14 for the 50 mg/mL dose. At days 21 and 28 there were no differences between treated and control wounds.

Cholestyramine in type IIa hyperlipoproteinemia. Is low-dose treatment feasible?

The present study was undertaken to evaluate the possible lipid-lowering effects of low-dose cholestyramine medication in type IIa hyperlipoproteinemia. A total of 16 patients, 8 with heterozygous familial hypercholesterolemia and 8 with polygenic hypercholesterolemia, were investigated. After an initial 3-month period of dietary treatment, 8 of the patients were randomly selected for medication with 4 g of cholestyramine twice daily, and the other 8 received a dose of 8 g twice daily for 2 months. The regimens were then exchanged, and the patients followed for a further 2 months. Plasma lipids and lipoprotein cholesterol were determined at intervals of 4 weeks. Total plasma cholesterol was reduced by 17% during treatment with 8 g and somewhat more (26%) during treatment with 16 g of cholestyramine daily. The decrease in plasma LDL cholesterol did not differ during treatment with 8 g (27%) and 16 g (31%); no changes in plasma triglycerides, VLDL- or HDL-cholesterol were seen. Although plasma LDL-cholesterol was higher in patients with familial hypercholesterolemia, there was no obvious influence of the genetic origin of hypercholesterolemia on the response. It is concluded that low-dose treatment with cholestyramine lowers, and sometimes normalizes, LDL-cholesterol in hypercholesterolemia. Furthermore, the LDL-cholesterol level obtained during the 16-g dose could be predicted from the response seen during treatment with 8 g of cholestyramine daily.

What can experimental colorectal cancer tell us about colorectal cancer in man?

From a survey of the etiology of colorectal cancer, consideration of the basic pathologic characteristics of ulcerative colitis and familial polyposis of the colon suggests that they might be sister diseases. Similarities in the primary and secondary target organs and in fecal steroid metabolism might be more than coincidental. Thus, it would seem reasonable to pay particular attention to several groups of patients who are receiving therapy or have had operations that alter bile acid and/or cholesterol metabolism: 1) patients who have had jejunoileal bypass procedures for morbid obesity or hypercholesterolemia, 2) patients taking cholestyramine and/or other anti-hyperlipidemic agents, 3) patients receiving chenodeoxycholic therapy to dissolve gallstones, 4) patients taking the birth control pill, and 5) young patients who have had a cholecystectomy. Proponents of such therapy and physicians treating patients who develop colonic cancer or polypoid disease after having had such therapy are encouraged to provide accurate reports.

[Drug treatment of primary hyperlipoproteinemia (author's transl)]

Cardiovascular disease has become the major cause of death in the Western countries. There is strong evidence that elevations of serum lipids contribute to the pathogenesis of premature atherosclerosis. The classification of the hyperlipoproteinemias has been most beneficial as a guide to development of dietary and pharmacological regimens for lowering serum lipid concentrations. The results of dietary and drug prevention trials are discussed. Insight into the mechanisms involved in lipoprotein metabolism as well as the mode of action and of side-effects of hypolipidemic drugs is reviewed. Using present knowledge of heart disease research, it is reasonable to suggest dietary and drug treatments for the high risk patient.

Cholestyramine and ileal by-pass in the treatment of familial hypercholesterolaemia

A comparison was made of the therapeutic effectiveness of cholestyramine and an ileal by-pass operation as hypocholesterolaemic measures in thirteen patients with familial xanthomatotic type II hypercholesterolaemia. Serum cholesterol and faecal steroids were measured before and at the end of a 10 day course of cholestyramine (32 g/day), and subsequently after an ileal by-pass operation. The mean decrease in serum cholesterol caused by cholestyramine (-17%) was significantly less than that caused by the surgical procedure (-33%). The increase in faecal steroid excretion, mainly as bile acids, was lower with cholestyramine (1.261 g/day) than after the ileal exclusion (2.176 g/day) and a positive correlation was found between the decrease in serum cholesterol and the increase in the faecal elimination of steroids of cholesterol origin. However, even though the increase in faecal steroids with cholestyramine was positively correlated with that resulting from ileal by-pass, the correlation between the corresponding changes in serum cholesterol level was not significant. The findings indicate that ileal by-pass decreases serum cholesterol and increases faecal elimination of cholesterol more effectively than cholestyramine, and that the decrease in the serum cholesterol level induced by ileal exclusion is not consistently predictable by the serum cholesterol response to the preceding cholestyramine treatment.