Maternal di-(2-ethylhexyl)-phthalate exposure influences essential fatty acid homeostasis in rat placenta.

Maintaining essential fatty acid (EFA) homeostasis during pregnancy is critical for fetal development. As the organ that controls the maternal-to-fetal supply of nutrients, the placenta plays a significant role in guiding EFA transfer to the fetus. Many EFA homeostasis proteins are regulated by peroxisome proliferator-activated receptors (PPARs). The metabolites of di-(2-ethylhexyl)-phthalate (DEHP), a ubiquitous environmental contaminant, might influence EFA homeostasis via trans-activation of PPARs with subsequent downstream effects on EFA transporters and enzymes. To investigate DEHP's effect on placental/fetal EFA homeostasis, female Sprague-Dawley rats were orally gavaged with either vehicle or DEHP at 750 or 1500 mg/kg/day from gestational day (GD) 0 to GD 19. Changes in the expression of several EFA homeostasis regulating proteins were determined in the junctional (JXN) and labyrinthine (LAB) zones of the placenta, including PPAR isoforms (alpha, beta and gamma), fatty acid translocase (FAT/CD36), fatty acid transport protein 1 (FATP1), plasma membrane fatty acid binding protein (FABPpm), heart cytoplasmic fatty acid binding protein (HFABP), cytochrome P450 (CYP) 4A1, and cyclooxygenase (COX)-1 and -2. Additionally, effects of DEHP maternal exposure on the placental transfer and fetal distribution of representative EFAs, arachidonic acid (AA) and docosahexaenoic acid (DHA), and the placental production of prostaglandins (PGs) were investigated. Expression of PPARalpha, PPARgamma, FAT/CD36, FATP1, HFABP and CYP4A1 was up-regulated in JXN and/or LAB while COX-2 was down-regulated in JXN. PPARbeta, FABPpm, and COX-1 demonstrated variable expression. Reduced directional maternal-to-fetal placental transfer and altered fetal distribution of AA and DHA were observed in concordance with a decreased total placental PG production. These results correlate with previous in vitro data, suggesting that DEHP could influence placental EFA homeostasis with potential downstream effects in the developing fetus.

Expression of CYP4A isoforms in developing rat placental tissue and rat trophoblastic cell models.

Maintaining fatty acid homeostasis during pregnancy is critical for normal fetal development. As an organ that controls nutrient supply from the mother to the fetus, the placenta plays a significant role in guiding fatty acid transfer to the developing fetus. The cytochrome P450 4A (CYP4A) subfamily of metabolizing enzymes is a group of structurally and functionally conserved proteins that are specialized in the omega/omega-1 hydroxylation of saturated and unsaturated fatty acids and their derivatives. To understand the function of the CYP4A system in the placenta and its significance in maintaining fetal fatty acid homeostasis, information about the placental expression of individual CYP4A isoforms is required. In the present study, we have elucidated the temporal and spatial patterns of expression of the four known rat CYP4A isoforms (CYP4A1, CYP4A2, CYP4A3, and CYP4A8) in the junctional and labyrinthine zones of the developing rat chorioallantoic placenta as well as two rat trophoblastic cell lines, HRP-1 and Rcho-1, using semi-quantitative RT-PCR and immunohistochemical analyses. The mRNA from the four rat CYP4A isoforms was detected in the developing rat placenta with CYP4A1 exhibiting the strongest expression (4A1 > 4A2 >> 4A3 approximately equal to 4A8). CYP4A1 was also detected by immunohistochemical staining in the developing rat placenta. We also observed CYP4A1 in both HRP-1 and Rcho-1 cells by RT-PCR, suggesting the utility of these cells as in vitro tools to study the effects of xenobiotics on placental fatty acid metabolism. Establishing the expression of CYP4A isoforms in these tissues and cell models provides a framework for further investigation of their functional and physiological significance in guiding proper fetal development.

Expression of PPAR, RXR isoforms and fatty acid transporting proteins in the rat and human gastrointestinal tracts.

Dietary fatty acid (FA) absorption across the gastrointestinal (GI) tract is of critical importance for sustenance, however, excessive FA absorption has also been linked to metabolic syndrome and associated disorders. The expression of isoforms that regulate the dietary FA absorption are not as well characterized in the GI tract as they are elsewhere. Peroxisome proliferator-activated receptors (PPARalpha, beta, and gamma) and 9-cis-retinoic acid receptors (RXRalpha, beta, and gamma) are nuclear hormone transcription factors that control FA homeostasis, in part through the regulation of expression of membrane-bound FA transporting proteins. The present study was designed to elucidate the expression of PPAR and RXR isoforms and FA transporting proteins (FABPpm and FAT/CD36) in the rat and human GI tracts using reverse transcriptase-polymerase chain reaction (RT-PCR), immunoblotting, and immunohistochemical staining. The results revealed rat GI expression of all the PPAR and RXR isoforms, FABPpm and FAT/CD36. PPARalpha, PPARbeta, PPARgamma, RXRalpha, FABPpm, and FAT/CD36 isoforms exhibited ubiquitous expression in human GI tract, whereas RXRbeta was not detected. RXRgamma was observed in a majority of the human GI samples. These results provide a physiological foundation for rational drug design and drug delivery for the mitigation of metabolic syndrome and associated disorders to normalize intestinal FA absorption.

Effect of chlorpyrifos on efflux transporter gene expression and function in Caco-2 cells.

The effect of chlorpyrifos (CPF) and its metabolite, chlorpyrifos-oxon (CPO), on multidrug resistance-1 (MDR1) gene expression and efflux transporter function in Caco-2 cells was determined. The effect of CPF and CPO on gene expression in Caco-2 cells was tested as a function of time using RT-PCR and competitive PCR (compPCR) techniques. The RT-PCR results depicted a maximal effect of CPF exposure on MDR1 expression at 8 h, which decreased at 24 h. Studies with CPO displayed an initial increase in expression at 4 h only. The compPCR assays were conducted with the CPF-treated group to quantify the changes in gene expression levels. The compPCR data confirmed and quantitated the results from the time-course study using semiquantitative RT-PCR. In addition to the gene expression studies, changes in efflux transporter function were investigated using Caco-2 cells grown on semipermeable membranes in Transwell plates. The permeability of verapamil was determined in cells treated for 8 h with CPF. Efflux ratios demonstrated that verapamil was effluxed at a higher rate from the CPF-treated cells as compared to the control group, confirming the inductive action of CPF on transporter function. These results suggest that CPF has the potential to modulate the bioavailability of drugs via changes in expression and function of membrane efflux transporters.

Naiadocystis phykoterion n. gen., n. sp. (Apicomplexa: Eugregarinida: Hirmocystidae), from the Mexican pygmy grasshopper, Paratettix mexicanus (Orthoptera: Tetrigidae), in the Texas big thicket with recognition of three previously described species of Naiadocystis.

Naiadocystis phykoterion n. gen., n. sp. (Apicomplexa: Eugregarinida: Hirmocystidae), is described from the Mexican pygmy grasshopper, Paratettix mexicanus (Orthoptera: Tetrigidae), collected from sandbars along Harmon Creek, Walker County, Texas, in the western edge of the Texas Big Thicket. Naiadocystis n. gen. is distinguished by the form of the epimerite complex, a simple cordoid or toroid epimerite with an interior obconoid structure resembling a funnel that tapers to a distinct axial canal bisecting the protomerite, which is conspicuous in all stages of development, and a satellite protomerite reduced to a linearly crateriform cup or sucker that receives and enfolds posterior end of primite deutomerite. Association is precocious, caudofrontal, and biassociative. Gametocysts are spherical. Sporoducts are present but vestigial and irregular in number. Oocysts are broadly elliptoid with 4 small spherical polar knobs, 1 each at 30 degrees, 150 degrees, 210 degrees, and 330 degrees, and dehisce en masse. The species described herein are differentiated by their overall size and relative proportion of cellular structures. Naiadocystis acantholobae (Hoshide, 1952) n. comb., Naiadocystis acrydiinarum (Semans, 1939) n. comb., and Naiadocystis tetrigis (Corbel, 1968) n. comb. are recognized as members of Naiadocystis previously placed within Gregarina (Apicomplexa: Eugregarinida: Gregarinidae).

Influence of low high-density lipoprotein cholesterol and elevated triglyceride on coronary heart disease events and response to simvastatin therapy in 4S.

BACKGROUND: Patients with low HDL cholesterol (HDL-C) and elevated triglyceride had an increased risk for coronary heart disease (CHD) events and received the greatest benefit with fibrate therapy in substudy analyses of the Helsinki Heart Study and the Bezafibrate Infarction Prevention Study. METHODS AND RESULTS: In this post hoc analysis of the Scandinavian Simvastatin Survival Study, which enrolled patients with elevated LDL cholesterol (LDL-C) and CHD, subgroups defined by HDL-C and triglyceride quartiles were compared to examine the influence of HDL-C and triglyceride on CHD events and response to therapy. Patients in the lowest HDL-C (<1.00 mmol/L [39 mg/dL]) and highest triglyceride (>1.80 mmol/L [159 mg/dL]) quartiles (lipid triad; n=458) had increased proportions of other features of the metabolic syndrome (increased body mass index, hypertension, diabetes), men, prior myocardial infarction, prior revascularization, and beta-blocker use than patients in the highest HDL-C (>1.34 mmol/L [52 mg/dL]) and lowest triglyceride (<1.11 mmol/L [98 mg/dL]) quartiles (isolated LDL-C elevation; n=545). The major coronary event rate was highest in lipid triad patients on placebo (35.9%), and this subgroup had the greatest event reduction (relative risk 0.48, 95% CI 0.33 to 0.69); a significant treatment-by-subgroup interaction (P=0.03) indicated a greater treatment effect in the lipid triad subgroup than the isolated LDL-C elevation subgroup. CONCLUSIONS: Patients with elevated LDL-C, low HDL-C, and elevated triglycerides were more likely than patients with isolated LDL-C elevation to have other characteristics of the metabolic syndrome, had increased risk for CHD events on placebo, and received greater benefit with simvastatin therapy.

Spatial expression patterns of peptide transporters in the human and rat gastrointestinal tracts, Caco-2 in vitro cell culture model, and multiple human tissues.

This study sought to identify the spatial patterns of expression of peptide transporter 1 (PepT1), peptide transporter 3 (PTR3), peptide/histidine transporter 1 (PHT1), and the human peptide transporter 1 (HPT-1) mRNA in complementary DNA (cDNA) libraries of the human and rat gastrointestinal tracts (GIT), Caco-2 in vitro cell culture model, and in a human multiple tissue panel. Human PTR3 and PHT1 are putative peptide transporters recently discovered. Using sequence-specific primers designed to amplify regions of PepT1, PTR3, PHT1, and HPT-1, we were able to identify the expression of mRNA for each of these transporters in human cDNA panels (Clontech, Palo Alto, CA), the rat GIT, and in Caco-2 cDNA libraries by the polymerase chain reaction (PCR) and Southern Blot analysis. These studies suggest that in the human GIT, PepT1 appears to be localized predominantly in the duodenum, with decreasing expression in the jejunum and ileum. In contrast, PTR3 and HPT-1 were widely expressed in the human GIT, with predominant expression in the different regions of the colon. PHT1 appeared to be expressed in low levels throughout the human GI tract. Interestingly, the mRNAs for all 4 peptide transporters were expressed in Caco-2 cells throughout 30 days of culture. PepT1, PTR3, PHT1, and HPT-1 were also widely expressed in the rat GIT. Human tissue cDNA panel screening suggests that PTR3 and PHT1 are more uniformly expressed, whereas PepT1 and HPT-1 demonstrated site-specific expression. These results suggest that PepT1, PTR3, PHT1, and HPT-1 all may act to facilitate the diffusion of peptides and peptide-based pharmaceuticals in the GIT. PTR3, PHT1, and HPT-1 expressions in Caco-2 cell monolayers strongly suggest that their function needs to be further elucidated and their contribution to peptide transport not ignored. Taken together, these results demonstrate the potential for molecular biological characterization in localizing active transporter systems that can potentially be targeted for enhancing the absorption of peptide-based pharmaceuticals.

Clinical predictors of spontaneous acute urinary retention in men with LUTS and clinical BPH: a comprehensive analysis of the pooled placebo groups of several large clinical trials.

OBJECTIVES: To comprehensively evaluate clinical predictors of spontaneous acute urinary retention (AUR) across pooled data of placebo-treated patients from clinical trials conducted in men with lower urinary tract symptoms and clinically diagnosed benign prostatic hyperplasia. METHODS: Data from the placebo-treatment groups of several prospective, randomized clinical trials conducted in the United States (n = 3040), Scandinavia, Canada, and worldwide (n = 2295) were combined in the analyses. More than 110 variables were considered individually and in combination as predictors of AUR using logistic regression analysis and classification and regression tree methods with a split-sample approach to cross-validation. RESULTS: The different methods of analysis identified consistent potential predictors of episodes of AUR. When prostate volume was included in the analyses, it was selected as the initial variable discriminating men with and without subsequent AUR. Omitting prostate volume because of its availability in only a subset of men, a logistic model including serum prostate-specific antigen (PSA), urinating more than every 2 hours, symptom problem index, maximum urinary flow rate, and hesitancy of urination had good predictive properties (area under the receiver-operating characteristic curve [AUC] = 0.742 +/- 0.047), as did a model with PSA (AUC = 0.716 +/- 0.045). A classification and regression decision tree with the same variables predicted AUR (AUC = 0.74, sensitivity = 72%, specificity = 67%) as well as did a tree with PSA alone (AUC = 0.70, sensitivity = 75%, specificity = 64%). CONCLUSIONS: Prostate volume and serum PSA are strong predictors of AUR in placebo-treated men with lower urinary tract symptoms and clinically diagnosed benign prostatic hyperplasia who were screened for prostate cancer. From more than 110 variables, logistic models and decision trees with PSA alone were comparable to expanded models that included PSA, urinary frequency and hesitancy, flow rate parameters, and symptom problem index, and to a scoring algorithm.

Comparison of the efficacy and safety of finasteride in older versus younger men with benign prostatic hyperplasia.

OBJECTIVES: To compare the efficacy and safety of finasteride 5 mg in older (65 years old or older) versus younger (45 to younger than 65 years old) men with benign prostatic hyperplasia (BPH). METHODS: The Proscar Long-Term Efficacy and Safety Study (PLESS) was a 4-year, randomized, double-blind, placebo-controlled trial assessing the efficacy and safety of finasteride 5 mg in 3040 men 45 to 78 years old with symptomatic BPH, enlarged prostates, and no evidence of prostate cancer. The endpoints included urinary symptoms, prostate volume, occurrence of acute urinary retention and/or BPH-related surgery, and safety. RESULTS: In both age cohorts, finasteride treatment led to a 51% reduction (P <0.001) in the relative risk for acute urinary retention and/or BPH-related surgery, a significant (P <0.001) and durable improvement in symptom score, and a significant (P <0.001) and sustained reduction in prostate volume. Within each age cohort, no significant differences were found between the placebo and finasteride-treated patients in the incidence of cardiovascular adverse events. Significant differences were evident between the placebo and finasteride groups in the incidence of the typical, known, drug-related adverse events, but no specific differences were associated with age. No drug interactions of clinical importance were observed in the finasteride-treated patients. CONCLUSIONS: The present analysis from PLESS demonstrates that in both older (65 years old or older) and younger men with symptomatic BPH and enlarged prostates, finasteride is highly effective in improving symptoms and reducing prostate volume in many men and in reducing the risk of acute urinary retention and BPH-related surgery. In addition, the safety profile of finasteride in both older and younger men is similar and no drug interactions of clinical importance were observed.

Follow-up study of patients randomized in the Scandinavian simvastatin survival study (4S) of cholesterol lowering.

The Scandinavian Simvastatin Survival Study (4S) and other randomized clinical trials have demonstrated that cholesterol-lowering treatment with statins improves prognosis in patients with coronary atherosclerosis compared with placebo. The effect of therapy with statins beyond the typical 5 to 6 years' duration of the trials, in particular regarding the risk of cancer, has not been investigated. This study examines the long-term effects of simvastatin for up to 8 years on cause-specific mortality in patients with coronary heart disease (CHD). We performed an observational, government registry-based study of mortality in the groups originally randomized to simvastatin or placebo in the 4S over an additional 2-year follow-up period, so that the median total follow-up period was 7.4 years (range 6.9 to 8.3 in surviving patients). Randomization took place at outpatient clinics at 94 clinical centers in Denmark, Finland, Iceland, Norway, and Sweden from 1988 to 1989. Of 4,444 patients with CHD, 2,223 and 2,221 were randomized to treatment with placebo or simvastatin therapy, respectively. Patients received treatment with simvastatin, starting at 20 mg/day, with titration to 40 mg/day at 12 or 24 weeks if total cholesterol was >5.2 mmol/L (200 mg/dl), or placebo. After the double-blind period, most patients in both treatment groups received simvastatin as open-label prescription. Of the 1,967 patients originally treated with placebo and surviving the double-blind period, 97 (4.9%) died during the following 2 years. In the group randomized to simvastatin the corresponding number was 74 of the 2, 039 survivors (3.6%). Adding these deaths to those occurring during the original trial, the total was 353 (15.9%) and 256 (11.5%) deaths in the groups originally randomized to placebo and simvastatin, respectively. The relative risk was 0.70 (95% confidence interval 0. 60 to 0.82, p = 0.00002). The total number of cancer deaths was 68 (3.1%) in the placebo group and 52 (2.3%) in the simvastatin group (relative risk 0.73, 95% confidence interval 0.51 to 0.05, p = 0. 087), and the numbers of noncardiovascular and other deaths were similar in both groups. We therefore conclude that treatment with simvastatin for up to 8 years in patients with CHD is safe and yields continued survival benefit.

Reduced coronary events in simvastatin-treated patients with coronary heart disease and diabetes or impaired fasting glucose levels: subgroup analyses in the Scandinavian Simvastatin Survival Study.

BACKGROUND: Patients with diabetes mellitus (DM) have a marked increase in coronary heart disease (CHD) events relative to those without DM. In a previous report from the Scandinavian Simvastatin Survival Study using a clinical case definition of DM (n = 202), simvastatin-treated patients had significantly fewer CHD events compared with placebo-treated control subjects. OBJECTIVE: To examine the effect of simvastatin therapy on CHD in patients with DM and impaired fasting glucose levels. METHODS: Using the 1997 American Diabetes Association diagnostic criteria, we assessed the effect of simvastatin therapy post hoc for an average of 5.4 years in Scandinavian Simvastatin Survival Study patients with normal fasting glucose (n = 3237), impaired fasting glucose (n = 678), and DM (n = 483). RESULTS: Simvastatin-treated patients with DM had significantly reduced numbers of major coronary events (relative risk [RR] = 0.58; P = .001) and revascularizations (RR = 0.52; P = .005). Total (RR = 0.79; P = .34) and coronary (RR = 0.72; P = .26) mortality were also reduced in DM, but not significantly, due to small sample size. In impaired fasting glucose (IFG) subjects, simvastatin use significantly reduced the number of major coronary events (RR = 0.62; P = .003), revascularizations (RR = 0.57; P = .009), and total (RR = 0.57; P = .02) and coronary (RR = 0.45; P = .007) mortality. CONCLUSION: Our results extend previous findings in patients with DM to a larger cohort, confirming the benefit of cholesterol lowering with simvastatin treatment on CHD events. In addition, significant decreases in total mortality, major coronary events, and revascularizations were observed in simvastatin-treated patients with impaired fasting glucose levels. These results strongly support the concept that cholesterol lowering with simvastatin therapy improves the prognosis of patients with elevated fasting glucose levels (> or =6.0 mmol/L [> or =110 mg/ dL]) or DM and known CHD.

Serum prostate-specific antigen concentration is a powerful predictor of acute urinary retention and need for surgery in men with clinical benign prostatic hyperplasia. PLESS Study Group.

OBJECTIVES: Prostate-specific antigen (PSA) is produced exclusively in the prostate gland and is currently the most useful clinical marker for the detection of prostate cancer. In this report, we examine whether serum PSA is also a predictor of important benign prostatic hyperplasia (BPH)-related outcomes, acute urinary retention (AUR), and the need for BPH-related surgery. METHODS: Three thousand forty men were treated with either placebo or finasteride in a double-blind, randomized study of 4-year duration. Serum PSA was measured at baseline, and baseline prostate volume was measured in a 10% subset of 312 men. Probabilities and cumulative incidences of AUR and BPH-related surgery, as well as reduction in risk of events with finasteride, were calculated for the entire patient population, stratified by treatment assignment, baseline serum PSA, and prostate volume. RESULTS: The risk of either needing BPH-related surgery or developing AUR ranged from 8.9% to 22.0% during the 4 years in placebo-treated patients stratified by increasing prostate volume and from 7.8% to 19.9% when stratified by increasing serum PSA. In comparison with symptom scores, flow rates, and residual urine volume, receiver operating characteristic curve analyses showed that serum PSA and prostate volume were the most powerful predictors of spontaneous AUR in placebo-treated patients (area under the curve 0.70 and 0.81, respectively). Finasteride treatment reduced the relative risk of needing surgery or developing AUR by 50% to 74% and by 43% to 60% when stratified by increasing prostate volume and serum PSA, respectively. CONCLUSIONS: Serum PSA and prostate volume are powerful predictors of the risk of AUR and the need for BPH-related surgery in men with BPH. Knowledge of baseline serum PSA and/or prostate volume are useful tools to aid physicians and decision makers in predicting the risk of BPH-related outcomes and choosing therapy for BPH.

Treatment with finasteride preserves usefulness of prostate-specific antigen in the detection of prostate cancer: results of a randomized, double-blind, placebo-controlled clinical trial. PLESS Study Group. Proscar Long-term Efficacy and Safety Study.

OBJECTIVES: To evaluate prostate cancer detection and prostate-specific antigen (PSA) among men with benign prostatic hyperplasia treated with finasteride. METHODS: Three thousand forty men 45 to 78 years of age with PSA less than 10 ng/mL and no history of prostate cancer were randomized in a double-blind, placebo-controlled trial to finasteride (n = 1524) or placebo (n = 1516) for up to 4 years. A prerandomization biopsy negative for prostate cancer was obtained in 98% of patients with a screening PSA of 4.0 ng/mL or more, and an end-of-study biopsy was requested of all such patients without a recent second negative biopsy or a prostate cancer diagnosis. RESULTS: Overall, 644 patients (21%) underwent biopsy and 201 (6.6%) underwent transurethral resection of the prostate. Prostate cancer was diagnosed in 4.7% of men on finasteride and 5.1% on placebo (P = 0.7). Elevated PSA prompted diagnosis in 35% of cases on finasteride and 34% on placebo. The area under the receiver operating characteristic curve for last PSA was 0.84 on finasteride and 0.79 on placebo (P = 0.07). Use of an upper limit of normal for last PSA of 2.0 ng/mL for finasteride and 4.0 ng/mL for placebo yielded similar sensitivity (66% versus 70%, P = 0.6), higher specificity (82% versus 74%, P < 0.0001), and a higher likelihood ratio (3.6 versus 2.7, P < 0.05) for finasteride than for placebo. CONCLUSIONS: In men treated with finasteride, multiplying PSA by 2 and using normal ranges for untreated men preserves the usefulness of PSA for prostate cancer detection.

Lipoprotein changes and reduction in the incidence of major coronary heart disease events in the Scandinavian Simvastatin Survival Study (4S)

BACKGROUND: The Scandinavian Simvastatin Survival Study (4S) randomized 4444 patients with coronary heart disease (CHD) and serum cholesterol 5.5 to 8.0 mmol/L (213 to 310 mg/dL) with triglycerides < or =2.5 mmol/L (220 mg/dL) to simvastatin 20 to 40 mg or placebo once daily. Over the median follow-up period of 5.4 years, one or more major coronary events (MCEs) occurred in 622 (28%) of the 2223 patients in the placebo group and 431 (19%) of the 2221 patients in the simvastatin group (34% risk reduction, P<.00001). Simvastatin produced substantial changes in several lipoprotein components, which we have attempted to relate to the beneficial effects observed. METHODS AND RESULTS: The Cox proportional hazards model was used to assess the relationship between lipid values (baseline, year 1, and percent change from baseline at year 1) and MCEs. The reduction in MCEs within the simvastatin group was highly correlated with on-treatment levels and changes from baseline in total and LDL cholesterol, apolipoprotein B, and less so with HDL cholesterol, but there was no clear relationship with triglycerides. We estimate that each additional 1% reduction in LDL cholesterol reduces MCE risk by 1.7% (95% CI, 1.0% to 2.4%; P<.00001). CONCLUSIONS: These analyses suggest that the beneficial effect of simvastatin in individual patients in 4S was determined mainly by the magnitude of the change in LDL cholesterol, and they are consistent with current guidelines that emphasize aggressive reduction of this lipid in CHD patients.

Effect of simvastatin on ischemic signs and symptoms in the Scandinavian simvastatin survival study (4S).

In patients participating in the Scandinavian Simvastatin Survival Study, cholesterol lowering with simvastatin reduced the incidence of carotid bruits and cerebrovascular events as well as new-onset or worsening of angina pectoris and intermittent claudication. These effects suggest that simvastatin may have a general antiatherosclerotic effect not limited to the coronary bed.

Evidence for diminished functional expression of intestinal transporters in Caco-2 cell monolayers at high passages.

PURPOSE: To investigate the effects of passaging on the intrinsic membrane transport parameters of compounds absorbed by means of passive and carrier-mediated processes in the Caco-2 cell line. METHODS: Caco-2 cells at low (28-36) and high (93-108) passage numbers were used to evaluate the transport characteristics of model compounds for paracellular diffusion (mannitol), transcellular diffusion (progesterone) and carrier-mediated transport (cephalexin, cephradine, phenylalanine, proline, and taurocholic acid) using side-by-side diffusion chambers. Intrinsic intestinal transport parameters were determined by correcting the effective permeability for potential biases introduced by the microporous filter and aqueous boundary layer. Intrinsic maximal flux (Jmax), Michaelis constant (K(m)) and carrier permeability (Pc) were determined as a function of passage number. RESULTS: Compared to the low passaged cells, the high passaged Caco-2 cells were characterized by less morphological heterogeneity, higher transepithelial electrical resistance, higher transcellular diffusion, lower paracellular diffusion, lower carrier-mediated transport and lower alkaline phosphatase activity. The use of effective transport parameters overestimated the K(m) and underestimated Pc but had no effect on Jmax. CONCLUSIONS: The current results provide experimental evidence that the passaging process significantly affects the biological characteristics and transport properties of Caco-2 cell monolayers. The effects are consistent with a reduction in the functional expression of a brush border enzyme and several transport proteins as passage number is increased. The underlying basis for this appears to be a selection of fast-growing subpopulations from the original heterogeneous Caco-2 cell line during passaging.

Cholesterol-lowering therapy in women and elderly patients with myocardial infarction or angina pectoris: findings from the Scandinavian Simvastatin Survival Study (4S)

BACKGROUND: The Scandinavian Simvastatin Survival Study (4S) demonstrated pronounced reductions in mortality and major coronary events in a cohort of patients with established coronary heart disease (CHD). The present study provides a detailed, post hoc assessment of the efficacy and safety of simvastatin therapy in the following subgroups of 4S patients: those > or = 65 years of age, those < 65 years of age, women, and men. METHODS AND RESULTS: The 4S cohort of 4444 CHD patients included 827 women and 1021 patients > or = 65 years of age. Total cholesterol at baseline was 5.5 to 8.0 mmol/L with triglycerides < or = 2.5 mmol/L. Patients were randomized to therapy with simvastatin 20 to 40 mg daily or placebo for a median follow-up period of 5.4 years. End points consisted of all-cause and CHD mortality, major coronary events (primarily CHD death and nonfatal myocardial infarction), other acute CHD and atherosclerotic events, hospitalizations for CHD and cardiovascular events, and coronary revascularization procedures. Mean changes in serum lipids were similar in the different subgroups. In patients > or = 65 years of age in the simvastatin group, relative risks (95% confidence intervals) for clinical events were as follows: all-cause mortality, 0.66 (0.48 to 0.90); CHD mortality, 0.57 (0.39 to 0.83); major coronary events, 0.66 (0.52 to 0.84); any atherosclerosis-related event, 0.67 (0.56 to 0.81); and revascularization procedures, 0.59 (0.41 to 0.84). In women, the corresponding figures were 1.16 (0.68 to 1.99); 0.86 (0.42 to 1.74), 0.66 (0.48 to 0.91), 0.71 (0.56 to 0.91), and 0.51 (0.30 to 0.86), respectively. CONCLUSIONS: Cholesterol lowering with simvastatin produced similar reductions in relative risk for major coronary events in women compared with men and in elderly (> or = 65 years of age) compared with younger patients. There were too few female deaths to assess the effects on mortality in women. Because mortality rates increased substantially with age, the absolute risk reduction for both all-cause and CHD mortality in simvastatin-treated subjects was approximately twice as great in the older patients.

Safety and tolerability of cholesterol lowering with simvastatin during 5 years in the Scandinavian Simvastatin Survival Study.

BACKGROUND: Long-term safety is an important consideration in the selection and use of drugs, such as lipid-lowering agents, that are prescribed to reduce the risk of clinical events during long periods. METHODS: The Scandinavian Simvastatin Survival Study was designed to evaluate the effects of cholesterol lowering with simvastatin on mortality and morbidity in patients with coronary heart disease. The 4444 patients aged 35 to 70 years (mean, 58.9 years) with angina pectoris or previous myocardial infarction and serum cholesterol levels of 5.5 to 8.0 mmol/L (213-310 mg/dL) receiving a lipid-lowering diet were randomly assigned to take double-blind treatment with simvastatin, 20 to 40 mg once daily, or placebo. In addition to previously reported end-point events, detailed clinical and laboratory safety data were collected during a median follow-up period of 5.4 years (range in survivors, 4.9-6.2 years). RESULTS: The only clearly drug-related serious adverse event during the 5.4-year median follow-up period was a single reversible case of myopathy. The frequencies of persistent elevations of hepatic aminotransferase levels above 3 times the upper limit of normal and of nonviral hepatitis in the simvastatin and placebo treatment groups were not significantly different. Examination of the lens showed no between-group differences, and no previously unrecognized adverse effects of the drug were observed. There were no significant between-group differences in adverse events in any body system. In particular, the frequency of adverse events related to the central nervous system was similar in both groups. CONCLUSION: The safety profile of simvastatin, 20 to 40 mg daily, over 5 years was excellent.