Effects of long-term fenofibrate therapy on cardiovascular events in 9795 people with type 2 diabetes mellitus (the FIELD study): randomised controlled trial

BACKGROUND

Patients with type 2 diabetes mellitus are at increased risk of cardiovascular disease, partly owing to dyslipidaemia, which can be amenable to fibrate therapy. We designed the Fenofibrate Intervention and Event Lowering in Diabetes (FIELD) study to assess the effect of fenofibrate on cardiovascular disease events in these patients.

METHODS

We did a multinational, randomised controlled trial with 9795 participants aged 50-75 years, with type 2 diabetes mellitus, and not taking statin therapy at study entry. After a placebo and a fenofibrate run-in phase, we randomly assigned patients (2131 with previous cardiovascular disease and 7664 without) with a total-cholesterol concentration of 3.0-6.5 mmol/L and a total-cholesterol/HDL-cholesterol ratio of 4.0 or more or plasma triglyceride of 1.0-5.0 mmol/L to micronised fenofibrate 200 mg daily (n=4895) or matching placebo (n=4900). Our primary outcome was coronary events (coronary heart disease death or non-fatal myocardial infarction); the outcome for prespecified subgroup analyses was total cardiovascular events (the composite of cardiovascular death, myocardial infarction, stroke, and coronary and carotid revascularisation). Analysis was by intention to treat. The study was prospectively registered (number ISRCTN 64783481).

FINDINGS

Vital status was confirmed on all but 22 patients. Averaged over the 5 years' study duration, similar proportions in each group discontinued study medication (10% placebo vs 11% fenofibrate) and more patients allocated placebo (17%) than fenofibrate (8%; p<0.0001) commenced other lipid treatments, predominantly statins. 5.9% (n=288) of patients on placebo and 5.2% (n=256) of those on fenofibrate had a coronary event (relative reduction of 11%; hazard ratio [HR] 0.89, 95% CI 0.75-1.05; p=0.16). This finding corresponds to a significant 24% reduction in non-fatal myocardial infarction (0.76, 0.62-0.94; p=0.010) and a non-significant increase in coronary heart disease mortality (1.19, 0.90-1.57; p=0.22). Total cardiovascular disease events were significantly reduced from 13.9% to 12.5% (0.89, 0.80-0.99; p=0.035). This finding included a 21% reduction in coronary revascularisation (0.79, 0.68-0.93; p=0.003). Total mortality was 6.6% in the placebo group and 7.3% in the fenofibrate group (p=0.18). Fenofibrate was associated with less albuminuria progression (p=0.002), and less retinopathy needing laser treatment (5.2%vs 3.6%, p=0.0003). There was a slight increase in pancreatitis (0.5%vs 0.8%, p=0.031) and pulmonary embolism (0.7%vs 1.1%, p=0.022), but no other significant adverse effects.

INTERPRETATION

Fenofibrate did not significantly reduce the risk of the primary outcome of coronary events. It did reduce total cardiovascular events, mainly due to fewer non-fatal myocardial infarctions and revascularisations. The higher rate of starting statin therapy in patients allocated placebo might have masked a moderately larger treatment benefit.

Hepatic arterial infusion of chemotherapy after resection of hepatic metastases from colorectal cancer

BACKGROUND

Two years after undergoing resection of liver metastases from colorectal cancer, about 65 percent of patients are alive and 25 percent are free of detectable disease. We tried to improve these outcomes by treating patients with hepatic arterial infusion of floxuridine plus systemic fluorouracil after liver resection.

METHODS

We randomly assigned 156 patients at the time of resection of hepatic metastases from colorectal cancer to receive six cycles of hepatic arterial infusion with floxuridine and dexamethasone plus intravenous fluorouracil, with or without leucovorin, or six weeks of similar systemic therapy alone. Patients were stratified according to previous treatment and the number of liver metastases identified at operation. The study end points were overall survival, survival without recurrence of hepatic metastases, and survival without any metastases at two years.

RESULTS

The actuarial rate of overall survival at two years was 86 percent in the group treated with local plus systemic chemotherapy and 72 percent in the group given systemic therapy alone (P=0.03). The median survival was 72.2 months in the combined-therapy group and 59.3 months in the monotherapy group, with a median follow-up of 62.7 months. After two years, the rates of survival free of hepatic recurrence were 90 percent in the monotherapy group and 60 percent in the monotherapy group (P<0.001), and the respective rates of progression-free survival were 57 percent and 42 percent (P=0.07). At two years, the risk ratio for death was 2.34 among patients treated with systemic therapy alone, as compared with patients who received combined therapy (95 percent confidence interval, 1.10 to 4.98; P=0.027), after adjustment for important variables. The rates of adverse effects of at least moderate severity were similar in the two groups, except for a higher frequency of diarrhea and hepatic effects in the combined-therapy group.

CONCLUSIONS

For patients who undergo resection of liver metastases from colorectal cancer, postoperative treatment with a combination of hepatic arterial infusion of floxuridine and intravenous fluorouracil improves the outcome at two years.

Long-term efficacy and safety of canagliflozin over 104 weeks in patients aged 55-80 years with type 2 diabetes

AIMS

The long-term efficacy and safety of canagliflozin, a sodium glucose co-transporter 2 inhibitor, was evaluated over 104 weeks in patients aged 55-80 years with type 2 diabetes mellitus (T2DM) inadequately controlled on a stable antihyperglycaemic agent regimen.

METHODS

In this randomized, double-blind, phase III study, patients received canagliflozin 100 or 300 mg or placebo once daily during a 26-week core period (N = 714) and a 78-week extension period (n = 624). Efficacy endpoints at week 104 included change from baseline in glycated haemoglobin (HbA1c), fasting plasma glucose (FPG) and systolic blood pressure, and percent change from baseline in body weight and fasting plasma lipids. Safety was assessed by adverse event (AE) reports.

RESULTS

At week 104, canagliflozin 100 and 300 mg were associated with reductions in HbA1c versus placebo (-0.32 and -0.43% vs 0.17%, respectively; overall mean baseline, 7.7%) and more patients achieved HbA1c <7.0% with canagliflozin 100 and 300 mg than with placebo (35.8 and 41.9% vs 20.3%, respectively). Reductions in FPG, body weight and systolic blood pressure, and increases in high-density lipoprotein cholesterol (HDL-C) and low-density lipoprotein cholesterol (LDL-C) were seen with canagliflozin compared with placebo. The overall incidence rates of AEs over 104 weeks were 88.0, 89.8 and 86.1% with canagliflozin 100 and 300 mg and placebo, respectively; serious AE rates were low across treatment groups. The incidence rates of urinary tract infections, genital mycotic infections and osmotic diuresis- and volume depletion-related AEs were higher with canagliflozin than with placebo.

CONCLUSION

Canagliflozin improved glycaemic control, reduced body weight and systolic blood pressure, and was generally well tolerated in patients aged 55-80 years with T2DM over 104 weeks.

Novel benzofuran and benzothiophene biphenyls as inhibitors of protein tyrosine phosphatase 1B with antihyperglycemic properties

Insulin resistance in the liver and peripheral tissues, together with a pancreatic cell defect, are the common causes of Type 2 diabetes. It is now appreciated that insulin resistance can result from a defect in the insulin receptor signaling system, at a site post binding of insulin to its receptor. Protein tyrosine phosphatases (PTPases) have been shown to be negative regulators of the insulin receptor. Inhibition of PTPases may be an effective method in the treatment of Type 2 diabetes. We have identified two novel series of benzofuran/benzothiophene biphenyl oxo-acetic acids and sulfonyl-salicylic acids as potent inhibitors of PTP1B with good oral antihyperglycemic activity. To assist in the design of these inhibitors, crystallographic studies have attempted to identify enzyme inhibitor interactions. Resolution of crystal complexes has suggested that the inhibitors bind to the enzyme active site and are held in place through hydrogen bonding and van der Waals interactions formed within two hydrophobic pockets. In the oxo-acetic acid series, hydrophobic substitutents at position-2 of the benzofuran/benzothiophene biphenyl framework interacted with Phe182 of the catalytic site and were very critical to the intrinsic activity of the molecule. The hydrophobic region of the catalytic-site pocket was exploited and taken advantage by hydrophobic substituents at either the alpha-carbon or the ortho aromatic positions of the oxo-acetic acid moiety. Similar ortho aromatic substitutions on the salicylic acid-type inhibitors had no effect, primarily due to the different orientation of these inhibitors in the catalytic site. The most active inhibitors of both series inhibited recombinant human PTP1B with phosphotyrosyl dodecapeptide TRDI(P)YETD(P)Y(P)YRK as the source of the substrate with IC(50) values in the range of 20-50 nM. Compound 68 was one of the most active compounds in vivo, normalizing plasma glucose levels at the 25 mg/kg dose (po) and the 1 mg/kg dose (ip). Compound 68 was also selective against several other PTPases.

Simple, inexpensive, reliable method for differentiation of Candida dubliniensis from Candida albicans

Candida dubliniensis is a recently described pathogenic species which shares many phenotypic features with Candida albicans, including the ability to form germ tubes and chlamydospores. These similarities have caused significant problems in the identification of C. dubliniensis by the average clinical mycology laboratory. To facilitate the differentiation of these species, we investigated the growth of 120 isolates of C. dubliniensis and 98 C. albicans isolates at 42 and 45 degrees C on Emmons' modified Sabouraud glucose agar (SGA) and 10 isolates of each species in yeast-peptone-dextrose broth. None of the C. dubliniensis isolates grew on the agar or in the broth medium at 45 degrees C, while 11 isolates were capable of growing on SGA at 42 degrees C. In contrast, all of the C. albicans isolates but one grew at 45 degrees C on or in either medium. These reproducible results clearly demonstrate that the incubation of isolates suspected to be C. dubliniensis or C. albicans at 45 degrees C provides a simple, reliable, and inexpensive method for the differentiation of the two species.

Phase I Study of Hepatic Arterial Infusion of Floxuridine and Dexamethasone With Systemic Irinotecan for Unresectable Hepatic Metastases From Colorectal Cancer

PURPOSE: To determine the maximum-tolerated dose (MTD) and dose-limiting toxicities of concurrent systemic irinotecan and hepatic arterial infusion (HAI) of floxuridine (FUDR) and dexamethasone in patients with unresectable hepatic metastases from colorectal cancer, to determine the safety of this combination in patients who have undergone cryosurgery, and to evaluate the pharmacokinetic effects of HAI FUDR on the metabolism of irinotecan.

PATIENTS AND METHODS: Forty-six previously treated patients with unresectable liver metastases and no known extrahepatic disease were treated concurrently with intravenous irinotecan weekly for 3 weeks and with HAI of FUDR and dexamethasone for 14 days (both were recycled in 28 days). Parallel cohorts of patients treated with or without cryosurgery were entered at escalating dose levels.

RESULTS: The MTD for patients who did not undergo cryosurgery was 100 mg/m2 of irinotecan weekly for 3 weeks every 4 weeks with concurrent HAI FUDR (0.16 mg/kg/d × pump volume/flow rate) plus dexamethasone for 14 days of a 28-day cycle. The dose-limiting toxicities were diarrhea and neutropenia. The response rate (complete and partial) among all patients who did not undergo cryosurgery was 74%. All patients in the cryosurgery group responded, and seven of the eight cryosurgery patients developed normal positron emission tomography scans after chemotherapy. HAI FUDR had no effect on the metabolism of irinotecan.

CONCLUSION: Combination therapy with HAI FUDR and dexamethasone plus systemic irinotecan may be safely administered to patients with unresectable hepatic metastases from colorectal cancer. The MTD has been reached for patients with unresectable disease, and we continue to investigate the MTD for patients who have undergone cryosurgery. Although the main objective of this study was to evaluate the toxicity of the combined regimen, a high response rate (74%) was observed.

A multicenter, double-blind, one-year study comparing safety and efficacy of atorvastatin versus simvastatin in patients with hypercholesterolemia

We directly compared the safety and efficacy of atorvastatin and simvastatin in hypercholesterolemic patients. This 1-year, randomized, double-blind study was performed at 9 community- and university-based research hospitals in Australia. One-hundred seventy-seven patients between the ages of 18 and 80 years with baseline low-density-lipoprotein (LDL) cholesterol > or = 4.14 and < or = 7.76 mmol/L (160 and 300 mg/dl, respectively) and triglycerides < or = 4.52 mmol/L (400 mg/dl) received once-daily dosing with atorvastatin (Lipitor) 10 mg or simvastatin (Zocor) 10 mg. At week 16, the dose of medication was titrated to atorvastatin 20 mg or simvastatin 20 mg if patients did not meet LDL cholesterol target of < or = 3.36 mmol/L (130 mg/dl). Efficacy was reported as percent change from baseline in LDL cholesterol, total cholesterol, very low density lipoprotein cholesterol, total triglycerides, high-density lipoprotein cholesterol, apolipoproteins AI and B, and lipoprotein(a). Atorvastatin caused significantly greater reductions from baseline than did simvastatin for LDL cholesterol, total cholesterol, very low density lipoprotein cholesterol, triglycerides, and apolipoprotein B (p <0.05). No patient in either treatment group had clinically important elevations in creatine phosphokinase, alanine aminotransaminase, or aspartate aminotransaminase. No serious adverse events were considered associated with treatment. With atorvastatin 10 mg, 46% of the patients achieved LDL cholesterol target goal by week 16, whereas only 27% of the simvastatin patients achieved the target goal at the 10-mg dose. This cholesterol-lowering profile affords utility in many patient types.

Novel spirosuccinimides with incorporated isoindolone and benzisothiazole 1,1-dioxide moieties as aldose reductase inhibitors and antihyperglycemic agents

Compounds from two novel series of spirosuccinimides were prepared. Analogs of series 2 possessed a spiro-fused isoindolone moiety while those of series 3 contained a spiro-fused benzisothiazole S,S-dioxide group. These compounds were evaluated as aldose reductase inhibitors (ARI) in vitro by their ability to inhibit glyceraldehyde reduction using a partially purified bovine lens aldose reductase preparation and in vivo as inhibitors of galactitol accumulation in the lens, sciatic nerve, and diaphragm of galactose-fed rats. Many members from the isoindolone series 2, particularly those containing an isoindolone N-methyl moiety, showed good in vitro and in vivo potency. The most potent member, the 6-chloro analog 32, was resolved, and aldose reductase activity was found to reside almost exclusively in the (+)-enantiomer. Compound 32 was approximately equipotent in the sciatic nerve of the galactose-fed rat to other cyclic imide ARI's of similar in vitro activity, namely sorbinil and ADN-138 and also to tolrestat, an acetic acid-based ARI (ED50's 4-8 mg/kg). Compounds from both series, 2 and 3, were also found to lower plasma glucose levels of genetically obese db/db and ob/ob mice with potency similar to that of ciglitazone. However, members from these series failed to lower insulin levels of the ob/ob mouse at the doses tested.

Widespread geographic distribution of oral Candida dubliniensis strains in human immunodeficiency virus-infected individuals

Candida dubliniensis is a recently identified chlamydospore-positive yeast species associated with oral candidiasis in human immunodeficiency virus (HIV)-infected (HIV+) patients and is closely related to Candida albicans. Several recent reports have described atypical oral Candida isolates with phenotypic and genetic properties similar to those of C. dubliniensis. In this study 10 atypical chlamydospore-positive oral isolates from HIV+ patients in Switzerland, the United Kingdom, and Argentina and 1 isolate from an HIV-negative Irish subject were compared to reference strains of C. albicans and Candida stellatoidea and reference strains of C. dubliniensis recovered from Irish and Australian HIV+ individuals. All 11 isolates were phenotypically and genetically similar to and phylogenetically identical to C. dubliniensis. These findings demonstrate that the geographical distribution of C. dubliniensis is widespread, and it is likely that it is a significant constituent of the normal oral flora with the potential to cause oral candidiasis, particularly in immunocompromised patients.

Oral L-arginine improves endothelium-dependent dilatation and reduces monocyte adhesion to endothelial cells in young men with coronary artery disease

L-Arginine is the physiological substrate for nitric oxide synthesis by the vascular endothelium. In hypercholesterolaemic rabbits, oral L-arginine reduces atheroma, improves endothelium-dependent dilatation and reduces monocyte/endothelial cell adhesion. The effect of oral L-arginine on endothelial physiology is unknown, however, in humans with established atherosclerosis. In a prospective, double-blind, randomised crossover trial, ten men aged 41 +/- 2 years with angiographically proven coronary atherosclerosis took L-arginine (7 g three times per day) or placebo for 3 days each, with a washout period of 10 days. After L-arginine, compared to placebo, plasma levels of arginine were increased (318 +/- 18 vs. 124 +/- 9 mumol/l, P < 0.01) and endothelium-dependent dilatation of the brachial artery (measured as the change in diameter in response to reactive hyperaemia, using external vascular ultrasound) was improved (4.7 +/- 1.1 vs. 1.8 +/- 0.7%, P < 0.04). No changes were seen in endothelium-independent dilatation of the brachial artery (measured as the change in diameter in response to sublingual nitroglycerine), blood pressure, heart rate or fasting lipid levels. Serum from six of the ten subjects after L-arginine and placebo was then added to confluent monolayers of human umbilical vein endothelial cells for 24 h, before human monocytes obtained by countercurrent centrifiguation elutriation were added and cell adhesion assessed by light microscopy. Adhesion was reduced following L-arginine compared to placebo (42 +/- 2 vs. 50 +/- 1%, P < 0.01). In young men with coronary artery disease, oral L-arginine improves endothelium-dependent dilatation and reduces monocyte/endothelial cell adhesion.

Phase I trial of vorinostat and doxorubicin in solid tumours: histone deacetylase 2 expression as a predictive marker

Background:

Histone deacetylase inhibitors (HDACi) can sensitise cancer cells to topoisomerase inhibitors by increasing their access and binding to DNA.

Methods:

This phase I trial was designed to determine the toxicity profile, tolerability, and recommended phase II dose of escalating doses of the HDACi vorinostat, with weekly doxorubicin.

Results:

In total, 32 patients were treated; vorinostat was dosed at 400, 600, 800, or 1000 mg day⁻¹ on days 1–3, followed by doxorubicin (20 mg m⁻²) on day 3 for 3 of 4 weeks. Maximal tolerated dose was determined to be 800 mg day⁻¹ of vorinostat. Dose-limiting toxicities were grade 3 nausea/vomiting (two out of six) and fatigue (one out of six) at 1000 mg day⁻¹. Non-dose-limiting grade 3/4 toxicities included haematological toxicity and venous thromboembolism. Antitumor activity in 24 evaluable patients included two partial responses (breast and prostate cancer). Two patients with melanoma had stable disease for ⩾8 months. Histone hyperacetylation changes in peripheral blood mononuclear and tumour cells were comparable. Histone hyperacetylation seemed to correlate with pre-treatment HDAC2 expression.

Conclusion:

These findings suggest that vorinostat can be combined with weekly doxorubicin in this schedule at a dose of 800 mg day⁻¹. The HDAC2 expression may be a marker predictive of HDAC inhibition. Antitumor activity of this regimen in breast cancer, prostate cancer, and melanoma seems interesting.

Histone deacetylase interacts directly with DNA topoisomerase II

Histone deacetylases (HDACs) modify nucleosomal histones, have a key role in the regulation of gene transcription, and may be involved in cell-cycle regulation, differentiation and human cancer. Purified recombinant human HDAC1 protein was used to screen a cDNA expression library, and one of the clones identified encoded DNA topoisomerase II (Topo II), an enzyme known to have a role in transcriptional regulation and chromatin organization. Coimmunoprecipitation experiments indicate that HDAC1 and HDAC2 are associated with Topo II in vivo under normal physiological conditions. Complexes containing Topo II possess HDAC activities, and complexes containing HDAC1 or HDAC2 possess Topo II activities. HDAC and Topo II modify each other's activity in vitro and in vivo. Our results indicate the existence of a functionally coupled complex between these two enzymes and offer insights into the potential mechanisms of action of both enzymes.

Cholesterol-lowering effects of plant sterol esters differ in milk, yoghurt, bread and cereal

OBJECTIVE

To measure the relative effects of each of four phytosterol ester-enriched low-fat foods (bread, breakfast cereal, milk and yoghurt) on serum lipids, plasma phytosterols and carotenoids.

DESIGN

: Three research centres undertook a randomised, incomplete crossover, single-blind study consisting of four treatment periods of 3 weeks each, one of which was a control period. Each sterol-enriched test food provided 1.6 g/day of phytosterols as sterol esters.

SETTING

General Community.

SUBJECTS

In all 58, free-living men and women with mean age (s.d.) 54 (8) y, moderately elevated plasma total cholesterol 6.2 (0.7) mmol/l and body mass index 26.2 (3.0) kg/m(2).

MAIN OUTCOME MEASURES

Serum lipids, plasma phytosterols and carotenoids.

RESULTS

Serum total and LDL cholesterol levels were significantly lowered by consumption of phytosterol-enriched foods: milk (8.7 and 15.9%) and yoghurt (5.6 and 8.6%). Serum LDL cholesterol levels fell significantly by 6.5% with bread and 5.4% with cereal. They were both significantly less efficacious than sterol-enriched milk (P<0.001). Plasma sitosterol increased by 17-23% and campesterol by 48-52% with phytosterol-enriched milk and bread. Lipid-adjusted beta-carotene was lowered by 5-10% by sterols in bread and milk, respectively.

CONCLUSIONS

This is the first study to demonstrate that cholesterol-lowering effects of plant sterol esters may differ according to the food matrix. Plant sterols in low-fat milk was almost three times more effective than in bread and cereal. Despite phytosterol-enriched cereal products resulting in lower serum cholesterol reductions compared to sterol-enriched milk, the detection of similar changes in plasma phytosterols demonstrated that such products still delivered and released phytosterols to the gut.

Medial restraints to anterior-posterior motion of the knee

We investigated the motion of cadaver knees before and after section of the medial structures and anterior cruciate ligament. The knees were tested using a 5-degrees-of-freedom in vitro knee-testing apparatus that measured anterior-posterior, medial-hateral, and axial displacement as well as internal-external and valgus-varus rotation. The fiexion angle could be varied but was fixed for each individual test. A 125-newton anterior-posterior force was applied perpendicular to the tibial shaft and the resulting motion of the knee was measured. In five knees the anterior cruciate ligament was cut first, followed by progressive cuts of the structures on the medial side (superficial medial collateral ligament, deep medial ligament, oblique fibers of the superficial medial ligament, and the posteromedial part of the capsule). Conversely, in five knees the medial structures were progressively cut first, followed by section of the anterior cruciate ligament. Tests were performed after each cut. With an intact anterior cruciate ligament, progressive cutting of the medial side had no effect on anterior and posterior displacements. When section of the medial structures followed cutting of the anterior cruciate ligament, anterior displacement exceeded that seen after isolated section of the anterior cruciate ligament. The anterior and posterior load-tests were repeated with the tibia fixed in 5 degrees of internal and 5 degrees of external rotation. Fixed external notation had no effect on anterior and posterior displacements. Fixed internal rotation significantly decreased anterior displacement only when both the anterior cruciate ligament and the medial structures were cut. The amounts of tibial rotation and tibial torque resulting from the applied anterior and posterior forces were low compared with our previous results, and we attributed this to decreased constraints on motion of the knee in the current testing apparatus.

CLINICAL RELEVANCE

Athletic injuries of the knee frequently involve both the anterior cruciate ligament and the medial side of the knee. Clinical studies have demonstrated that combined injuries of the anterior cruciate and medial collateral ligaments often cannot be successfully managed conservatively. Our in vitro findings support the clinical data and suggest that injuries to the medial structures further compromise anterior stability when they accompany anterior cruciate injuries.

Diagnostic performance characteristics of architectural features revealed by high spatial-resolution MR imaging of the breast

OBJECTIVE

Our objective was twofold: to determine which architectural features revealed by high spatial-resolution MR imaging of the breast contribute to diagnostic accuracy and to evaluate the diagnostic performance characteristics of those architectural features.

MATERIALS AND METHODS

Eligible patients with suspicious mammographic or palpable findings or both underwent MR imaging. Ninety-three patients whose MR images revealed lesions that corresponded to the mammographically visible or palpable findings were included in the study. Patients were examined with sagittal T1-weighted spin-echo MR imaging, fat-saturated T2-weighted fast spin-echo MR imaging, and dynamically enhanced fat-saturated fast gradient-echo MR imaging. All patients underwent subsequent excisional biopsy or cyst aspiration. Lesions were identified initially by an experienced radiologist who was aware of the patient's clinical or mammographic information. Two radiologists who were unaware of the patients' histories and who had less experience in MR imaging of the breast then independently evaluated each lesion for the architectural-features and predicted each lesion's potential for malignancy.

RESULTS

Architectural features that were highly predictive of benign disease included smooth or lobulated borders (97-100%), the absence of mass enhancement (100%), and enhancement that was less than the enhancement of surrounding breast fibroglandular tissue (93-100%). Nonenhancing internal septations were specific for the diagnosis of fibroadenoma. Architectural features that were highly predictive of malignant disease included spiculated borders (76-88%) and peripheral rim enhancement in the presence of central lesion enhancement (79-92%).

CONCLUSION

Architectural features revealed by high spatial-resolution MR imaging of the breast can help distinguish benign from malignant disease.

Evolution of hepatitis C virus quasispecies in hypervariable region 1 and the putative interferon sensitivity-determining region during interferon therapy and natural infection

To study hepatitis C virus (HCV) genetic mutation during interferon (IFN) therapy, the temporal changes in HCV quasispecies heterogeneity were compared before and after treatment for nine patients infected with HCV genotype 1, including four nonresponders, four responders who relapsed after therapy, and one responder who experienced a breakthrough of viremia during therapy. Nine untreated patients with an average time between specimens of 8.4 years served as controls. Sequences from the second envelope glycoprotein gene hypervariable region 1 (HVR1) and the putative IFN sensitivity-determining region (ISDR) of the nonstructural NS5A gene were analyzed by heteroduplex mobility assays and nucleotide sequencing. A strong positive correlation was found between the percent change in a heteroduplex mobility ratio (HMR) and percent change in nucleotide sequence (r = 0.941, P < 0.001). The rate of fixation of mutations in the HVR1 was significantly higher for IFN-treated patients than for controls (6.97 versus 1.31% change in HMR/year; P = 0.02). Similarly, a higher rate of fixation of mutations was observed in the ISDR for IFN-treated patients than for untreated controls, although the result was not significant (1.45 versus 0.15 amino acid changes/year; P = 0.12). On an individual patient basis, IFN therapy was associated with measurable HVR1 and ISDR mutation in nine of nine (100%) and two of nine (22.2%) patients, respectively. Evolution to IFN-resistant ISDR sequences was observed in only one of nine IFN-treated patients. These data suggest that IFN therapy frequently exerts pressure on the HCV envelope region, while pressure on the ISDR was evident in only a subset of patients. Thus, the selection pressures evoked on HCV genotype 1 quasispecies during IFN therapy appear to differ among different patients.

Oligonucleotide fingerprinting of isolates of Candida species other than C. albicans and of atypical Candida species from human immunodeficiency virus-positive and AIDS patients

Oligonucleotide fingerprinting of genomic DNA from oral isolates of four different Candida species other than C. albicans and atypical chlamydospore-positive isolates from human immunodeficiency virus (HIV)-positive individuals and AIDS patients was investigated as a means for differentiating between isolates within individual species. Oligonucleotides composed of simple repetitive sequence motifs, including (GACA)4, (GATA)4, (GGAT)4, (GTG)5, and (GT)8, all yielded fingerprints suitable for strain segregation of 8 C. tropicalis isolates, 12 Torulopsis (Candida) glabrata isolates, 8 atypical Candida isolates, and, except for (GATA)4, 2 C. krusei probe in turn and so generate several distinct DNA fingerprints of the same DNA sample. However, none of the probes yielded fingerprints suitable for strain segregation with three C. parapsilosis isolates. The (GATA)4 probe was also used to detect restriction fragment length polymorphisms among a genetically closely related group of atypical Candida isolates on primary isolation from an additional HIV-infected patient. These chlamydospore-positive atypical Candida isolates were sucrose positive, were of C. albicans serotype A, hybridized weakly with the C. albicans-specific mid-repeat sequence probe 27A, and yielded fingerprint profiles by random polymorphic DNA analysis that were distinct from those derived from C. albicans isolates. The C. stellatoidea ex-type strain NCPF 3108 was indistinguishable from the atypical Candida isolates in all these tests and also yielded an identical carbohydrate and nitrogen source assimilation profile by using the ID 32C yeast identification system.

Prospective characterization of full-length hepatitis C virus NS5A quasispecies during induction and combination antiviral therapy

The hepatitis C virus (HCV) nonstructural 5A (NS5A) protein has been controversially implicated in the inherent resistance of HCV to interferon (IFN) antiviral therapy in clinical studies. In this study, the relationship between NS5A mutations and selection pressures before and during antiviral therapy and virologic response to therapy were investigated. Full-length NS5A clones were sequenced from 20 HCV genotype 1-infected patients in a prospective, randomized clinical trial of IFN induction (daily) therapy and IFN plus ribavirin combination therapy. Pretreatment NS5A nucleotide and amino acid phylogenies did not correlate with clinical IFN responses and domains involved in NS5A functions in vitro were all well conserved before and during treatment. A consensus IFN sensitivity-determining region (ISDR(237-276)) sequence associated with IFN resistance was not found, although the presence of Ala(245) within the ISDR was associated with nonresponse to treatment in genotype 1a-infected patients (P<0.01). There were more mutations in the 26 amino acids downstream of the ISDR required for PKR binding in pretreatment isolates from responders versus nonresponders in both HCV-1a- and HCV-1b-infected patients (P<0.05). In HCV-1a patients, more amino acid changes were observed in isolates from IFN-sensitive patients (P<0.001), and the mutations appeared to be concentrated in two variable regions in the C terminus of NS5A, that corresponded to the previously described V3 region and a new variable region, 310 to 330. Selection of pretreatment minor V3 quasispecies was observed within the first 2 to 6 weeks of therapy in responders but not nonresponders, whereas the ISDR and PKR binding domains did not change in either patient response group. These data suggest that host-mediated selective pressures act primarily on the C terminus of NS5A and that NS5A can perturb or evade the IFN-induced antiviral response using sequences outside of the putative ISDR. Mechanistic studies are needed to address the role of the C terminus of NS5A in HCV replication and antiviral resistance.

Enhanced peripheral vasodilation in humans after a fatty meal

OBJECTIVES

We sought to study the effects of a fatty meal on vascular reactivity, including endothelial function and maximal vasodilation.

BACKGROUND

Recent reports regarding the physiological changes in peripheral vasculature after eating a fatty meal have been controversial.

METHODS

Twelve volunteers were studied before, 3 h after, and 6 h after a high-fat meal (1030 kcal, 61 g fat) rich in saturated fatty acids, and 10 were restudied after a similar meal rich in monounsaturated fatty acids. Endothelial function was assessed as flow-mediated dilatation (FMD) in the brachial artery using ultrasound. Resting and postischemic forearm blood flow (FBF) were recorded using venous occlusion strain-gauge plethysmography, before, and every 10 to 15 s after, 5 min upper arm ischemia.

RESULTS

Brachial artery basal diameter, resting FBF and postischemic hyperemia increased after high-fat meals (all p<0.001), whereas FMD did not change. The increase in resting FBF correlated with increases in postprandial insulin (r = 0.80, p<0.002) and triglyceride (r = 0.77, p<0.005) levels.

CONCLUSIONS

We concluded that eating a fatty meal induces vasodilation and increases resting and stimulated FBF and that these observations are probably mediated by postprandial changes in insulin and/or triglyceride levels. The metabolic changes that occur after meals are not associated with impaired endothelial nitric oxide release in the conduit arteries.