Biomedical subjects

Timothy B McPherson

Publications and source records attributed to Timothy B McPherson.

5 recordsLinked to original sources

PubMed2006

Effect of plant stanol tablets on low-density lipoprotein cholesterol lowering in patients on statin drugs.

The objective of this study was to show that plant sterols in tablet form provide additional low-density lipoprotein (LDL) cholesterol lowering for patients on statin therapy. Dispersible phytosterol tablets were tested in a double-blind, placebo-controlled, parallel clinical trial. Twenty-six patients who were following the American Heart Association Heart Healthy Diet and on long-term statin therapy were studied for 9 weeks. After 3 weeks of placebo treatment, the subjects were randomized to receive either 1.8 g of soy stanols or placebo for 6 weeks in addition to their usual statin regimen. Stanol tablets reduced LDL cholesterol 9.1% (p = 0.007) or 12.2 mg/dl. Total cholesterol was reduced by 12.9 mg/dl (p = 0.03). A strong inverse correlation (r(s) = -0.82, p = 0.0007) was found between the baseline LDL cholesterol and the percent change in LDL cholesterol observed after stanol treatment. The additional LDL cholesterol lowering with stanol/lecithin tablets provided a potential adjunctive therapy for patients who have not reached their target LDL cholesterol goal during statin therapy.

Adult↗

PubMed2005

Phytostanol tablets reduce human LDL-cholesterol.

The feasibility of using solid dosage forms containing stanol lecithin to lower human LDL-cholesterol was investigated. The particle size distribution of a coarse aqueous dispersion of a stanol lecithin mixture was determined at various weight ratios of the components. At a stanol-to-lecithin weight ratio of 1.00-1.50, dispersions could be spray dried and the solid reconstituted with water to produce a particle size distribution that was similar to that of the aqueous dispersion from which it was derived. Two solid dosage forms containing this spray-dried stanol lecithin preparation had different disintegration times--tablets less than 10 min and capsules greater than 45 min. Each delivery system was then tested for LDL-cholesterol reduction activity in a placebo-controlled, double-blind clinical trial containing a total of 52 subjects. After a six-week treatment period, the group that received rapidly disintegrating stanol lecithin tablets (1.26 g stanols daily) experienced a decrease in both LDL-cholesterol and the ratio of LDL-cholesterol to HDL-cholesterol by 10.4% (P = 0.01) and 11.5% (P = 0.03), respectively, relative to placebo. On the other hand, with slowly disintegrating capsules (1.01 g daily) there was no statistically significant difference in any lipid parameter between the active group and placebo group. Taken together, these studies demonstrate that for maximum LDL-cholesterol reduction activity the stanol lecithin formulation must be delivered in a rapidly dispersible form to reach the site of cholesterol absorption.

Administration, Oral↗

PubMed2003

Fat-free foods supplemented with soy stanol-lecithin powder reduce cholesterol absorption and LDL cholesterol.

OBJECTIVE: The objective of this work was to show that fat-free, lecithin-formulated soy stanols lower cholesterol absorption and serum LDL cholesterol. DESIGN: Reduction in cholesterol absorption was measured in paired single-meal tests with or without formulated soy stanols (acute test), and changes in serum lipids were investigated in a 10-week, randomized, double-blind parallel trial in which formulated stanols or lecithin vehicle were given three times daily for the last 4 weeks (chronic test). SUBJECTS/SETTING: Forty-five normal or mildly hypercholesterolemic subjects were recruited for both studies. The 21 subjects (16 female, 5 male; mean age 32.5 years) in the absorption studies had the following mean lipid values: LDL cholesterol, 2.79 mmol/L and total cholesterol, 4.73 mmol/L. For the lipid reduction, 24 subjects (16 female, 8 male; mean age 50.6 years) were enrolled with mean LDL cholesterol and total cholesterol of 3.72 mmol/L and 5.66 mmol/L, respectively. INTERVENTION: Reduction in cholesterol absorption was measured using a lemonade beverage or egg whites that contained 625 mg stanols. Throughout the chronic study, subjects followed the American Heart Association Step I diet. During the 4-week treatment phase, subjects consumed daily a lemonade-flavored beverage containing either placebo or formulated soy stanols (1.9 g). MAIN OUTCOME MEASURES: Inhibition of cholesterol absorption was determined from the difference in plasma deuterated cholesterol enrichment after a test meal containing stanol-lecithin and one with lecithin vehicle only. In the chronic study, the primary endpoints were changes in LDL and total cholesterol. STATISTICAL ANALYSES PERFORMED: Paired or unpaired t tests were used to determine statistical significance. RESULTS: Stanol-lecithin reduced cholesterol absorption by 32.1% (P=.0045, n=10) and by 38.2% (P=.0022, n=11) when delivered in a lemonade-flavored beverage and in egg whites, respectively. Reduction in cholesterol absorption was strongly related to the initial level of absorbed cholesterol tracer in serum (r(s)=-0.739). Stanol-lecithin given in a beverage reduced total serum cholesterol by 10.1% (P=.0019, n=24) and LDL cholesterol by 14.3% (P=.0016, n=24). APPLICATIONS/CONCLUSIONS: Powdered soy stanol-lecithin lowers cholesterol absorption and LDL cholesterol when consumed in fat-free foods.

Adult↗

PubMed2002

The Th2-restricted immune response to xenogeneic small intestinal submucosa does not influence systemic protective immunity to viral and bacterial pathogens.

Implantation of mice with xenogeneic extracellular matrix (ECM) not only results in tissue remodeling but also elicits a strong Th2 immune response. It is possible that the Th2 cytokines induced by ECM act systemically and result in immune suppression to unrelated antigens. In this case, the recipient would be predisposed to immune dysfunction and have increased susceptibility to various pathogens. The purpose of this study was to determine if ECM implantation does, in fact, influence the immune response to other antigens. Four models were examined to determine the effects of ECM implantation on systemic immunity. In the first model, mice were subcutaneously implanted with porcine small intestinal submucosa (SIS) and immunized with a T-dependent subunit vaccine against influenza virus. The antibody response and protection against lethal infection were then measured. The second model consisted of similar experiments performed using a T-independent polysaccharide vaccine against S. pneumoniae. In the third model, mice were implanted and the cell-mediated response to dinitrofluorobenzene (DNFB) challenge was determined. The fourth model involved examining the influence of SIS implantation on rejection of xenogeneic skin grafts. We found that antibody levels of mice vaccinated against influenza virus or S. pneumoniae were not affected by SIS implantation and these mice did not exhibit increased or decreased susceptibility to either infectious agent. Similarly, mice implanted with ECM showed no cell-mediated immune dysfunction upon challenge with DNFB or xenogeneic skin grafts. The results of this study demonstrate that the Th2-restricted response induced by xenogeneic ECM implantation does not cause generalized immune suppression. Therefore, SIS implantation does not increase susceptibility to viral or bacterial pathogenic agents.

Animals↗

PubMedDate not supplied

Prevalence of compounding in independent community pharmacy practice.

OBJECTIVES: To determine the extent of prescription compounding in independent community pharmacies and identify factors that influence the decision of independent pharmacists whether to provide compounding services. DESIGN: Cross-sectional survey. SETTING: Illinois, Missouri, Kansas, and Iowa. PARTICIPANTS: 370 pharmacists in charge. INTERVENTION: Anonymous questionnaire mailed in January 2005. MAIN OUTCOME MEASURES: Percentage of pharmacies that provide compounding; percentage of dispensed prescriptions that require compounding; factors contributing to decisions whether to provide compounding service. RESULTS: Overall, 94% of respondent pharmacies provided compounding services at the time of this survey. Prescriptions that required compounding represented less than 1% of total prescriptions for the majority (58.3%) of respondents. The main reasons for the decision to provide compounding service were wanting to provide full pharmaceutical care to patients (73.8% of compounders) and responding to requests by prescribers (48.7%). Pharmacies that did not provide compounding service cited the main reason as not receiving prescriptions that required compounding (63.6% of noncompounders). CONCLUSION: Compounding remains a component of pharmacy practice in the independent community setting. Prescriptions that required compounding represented 2.3% of all prescriptions dispensed by compounding pharmacies.

Community Pharmacy Services↗