Drug-related Effects Research Articles

Emergence of Neuroleptic Malignant Syndrome While Switching Between Risperidone and Paliperidone

Emergence of Neuroleptic Malignant Syndrome While Switching Between Risperidone and Paliperidone

Corticotropin-Releasing Factor Receptor 1 Antagonist Alters Regional Activation and Effective Connectivity in an Emotional–Arousal Circuit during Expectation of Abdominal Pain

Alterations in corticotropin-releasing factor (CRF) signaling pathways have been implicated in irritable bowel syndrome (IBS) pathophysiology. We aimed to (1) determine the effect of the selective CRF receptor 1 antagonist (CRF(1)) GW876008 relative to placebo, on regional activation and effective connectivity of a stress-related emotional-arousal circuit during expectation of abdominal pain using functional magnetic resonance imaging in human subjects with a diagnosis of IBS and healthy controls (HCs), and (2) examine GW876008 effects on state-trait anxiety and hypothalamic-pituitary-adrenal (HPA) axis response. Although there were no drug-related effects on peripheral HPA activity, significant central effects were observed in brain regions associated with the stress response. Effective connectivity analysis showed drug-induced normalizations between key regions of the emotional-arousal circuit in patients. During pain expectation, orally administered GW876008 relative to placebo produced significant blood oxygen level-dependent (BOLD) signal reductions in the amygdala, hippocampus, insula, anterior cingulate, and orbitomedial prefrontal cortices across groups. Patients showed significantly greater BOLD responses in the left locus coeruleus and hypothalamus after placebo compared with HCs, and BOLD signal decreases in the left hypothalamus after drug. The inhibitory effects of GW876008 in the hypothalamus in patients were moderated by anxiety; patients having average and high levels of state anxiety showed drug-related BOLD decreases. GW876008 represents a novel tool for elucidating the neuronal mechanisms and circuitry underlying hyperactivation of CRF/CRF(1) signaling and its role in IBS pathophysiology. The unique state anxiety effects observed suggest a potential pathway for therapeutic benefit of CRF(1) receptor antagonism for patients with stress-sensitive disorders.

Effects of Inhaled Mometasone Furoate on Growth Velocity and Adrenal Function: A Placebo-Controlled Trial in Children 4–9 Years Old with Mild Persistent Asthma

Objective. To assess the effects of long-term mometasone furoate delivered via a dry powder inhaler (MF-DPI) on growth velocity and hypothalamic–pituitary–adrenal axis function in children with asthma. Study design. Children aged 4–9 years with asthma (n = 187) were randomized to MF-DPI 100 μg (delivered dose; actuated dose is 110 μg) once daily in the morning (QD AM), 100 μg twice daily (BID), 200 μg QD AM, or placebo for 52 weeks followed by a 3-month follow-up period. The primary outcome was growth velocity calculated from stadiometric heights recorded at each visit. Secondary outcomes included serum and 12-h urinary cortisol, serum osteocalcin, and urinary N-telopeptide. Results. MF-DPI 100 μg QD AM treatment did not significantly affect growth velocity compared with placebo (–0.10 ± 0.31 cm/y, p = 0.76). When the effect of a total daily dose of 200 μg MF-DPI on growth velocity was examined, no significant effect was demonstrated for MF-DPI 100 μg BID compared with placebo (–0.64 ± 0.39 cm/y, p = 0.10), although the change in mean growth velocity with MF-DPI 200 μg QD AM reached statistical significance (–0.70 ± 0.29 cm/y, p = 0.02). The effects of all examined doses of MF-DPI on mean plasma cortisol levels were similar to cortisol changes seen in the placebo group, suggesting an absence of drug-related effects. No differences in 12-h urinary cortisol or other outcomes were observed between groups. Conclusions. One year of treatment with a total daily dose of 100 μg of MF-DPI in the morning resulted in no significant difference, whereas a total daily dose of 200 μg of MF-DPI was associated with some changes in growth velocity when compared with placebo. The differences in growth velocity, and the absence of drug-related cortisol effects, support the use of a total daily dose of 100 μg of MF-DPI in children aged 4–9 years with mild persistent asthma.

The novel use of decorin in prevention of the development of proliferative vitreoretinopathy (PVR)

The cytokine transforming growth factor-ß (TGF-ß) is a pivotal contributor to tissue fibrosis and a key cytokine in the pathogenesis of cellular transdifferentiation, epithelial-mesenchymal transition (EMT), and cell adhesion. This study evaluates the effect of decorin, a naturally occurring TGF-ß inhibitor, in an experimental rabbit model for proliferative vitreoretinopathy (PVR). Traumatic PVR was induced in 50 rabbits divided into ten groups (n = 5). One group (GI) reveals a control with no treatment after trauma. Groups (GII-GIV) consisted of subgroups receiving phacovitrectomy at three different time points; (a) at the time of trauma, (b) 1 week following trauma, and (c) 2 weeks following trauma. GIII and GIV received 100 μg or 200 μg decorin, respectively. PVR severity was scored from 0 to 4. The amount of fibrosis was quantified using JMicroVision© software. The control group GI developed severe PVR with tractional retinal detachment (TRD); (PVR score ≥2) in four rabbits out of five. Vitrectomy had a positive effect (p < 0.05) on PVR development when preformed immediately, however the developed fibrosis was high. The best results were obtained when surgery was used in conjunction with decorin that reduced both the PVR score and fibrosis development significantly (p < 0.05). Depending on dosage and time of vitrectomy, PVR could be completely avoided (PVR score = 0) in 16 rabbits out of 30. TRD was prevented in 13 rabbits out of 15 in GIII to 14 rabbits out of 15 in GIV. In decorin-treated eyes, vitrectomy outcome was best when preformed at 1 week after trauma. There were no drug-related toxic effects evident on clinical and histopathological examination. In conclusion, in this rabbit model of PVR, adjuvant decorin application during vitrectomy effectively reduces fibrosis and TRD development. In conjunction with no obvious histopathological toxicity signs, decorin represents a promising substance to inhibit PVR reactions.

Biodistribution and human dosimetry of enantiomer-1 of the synthetic leucine analog anti-1-amino-2-fluorocyclopentyl-1-carboxylic acid

The enantiomerically enriched (ee=90%, enantiomer 1) synthetic amino acid (R,S)-anti-1-amino-2-fluorocyclopentyl-1-carboxylic acid (anti-2-[(18)F]FACPC-1) accumulates in malignant cells by elevated transport through the sodium-independent system-L (leucine preferring) amino acid transporter. The purpose of this study was to evaluate in vivo uptake and single-dose toxicity of anti-2-[(18)F]FACPC-1 in animals as well as the individual organ and whole-body dose in humans. A DU145 xenograft rodent model was used to measure anti-2-[(18)F]FACPC-1 uptake at 15, 30 and 60 min post-injection. Animals were sacrificed and organs harvested to measure the percent injected activity per organ and to calculate residence time. Anti-2-[(18)F]FACPC-1 toxicity was assessed using a single microdose (37-74 MBq/kg) in nonhuman primates. Their vital signs were monitored for 2 h post-injection for drug-related effects. Human biodistribution studies were collected by sequential whole-body PET/CT scans on six healthy volunteers (three male and three female) for 120 min following a single 247±61 MBq bolus injection of anti-2-[(18)F]FACPC-1. Estimates of radiation dose from anti-2-[(18)F]FACPC-1 to the human body were calculated using recommendations of the MIRD committee and MIRDOSE 3.0 software. High anti-2-[(18)F]FACPC-1 residence time was observed in the pancreas of the rodent model compared to the human data. No abnormal treatment-related observations were made in the nonhuman primate toxicity studies. Human venous blood showed no metabolites of anti-2-[(18)F]FACPC-1 in the first 60 min post-injection. All volunteers showed initially high uptake in the kidneys followed by a rapid washout phase. The estimated effective dose equivalent was 0.0196 mSv/MBq. Anti-2-[(18)F]FACPC-1 showed low background uptake in the brain, thoracic and abdominal cavities of humans, suggesting a possible use for detecting malignant tissues in these regions.

Atypical antipsychotics and effects of muscarinic, serotonergic, dopaminergic and histaminergic receptor binding on insulin secretion in vivo: An animal model

The atypical antipsychotics (AAPs) have been associated with increased risk of type-2 diabetes. Evidence suggests direct, drug-related effects independent of weight gain and although mechanisms underlying this phenomenon are unclear, it has been suggested that the heterogeneous receptor binding profile of the AAPs may influence receptors implicated in glucose metabolism. This study aimed to clarify weight gain-independent mechanisms of AAP-induced changes in insulin secretion by deconstructing their binding profile with representative antagonists. Healthy rats were pretreated with a single subcutaneous dose of darifenacin 6 mg/kg (n = 10), a selective M 3 muscarinic antagonist; ketanserin 2 mg/kg (n = 10), a 5HT 2A antagonist; raclopride 0.3 mg/kg (n = 11) a selective D 2/D 3 antagonist; terfenadine 20 mg/kg (n = 9) a selective H 1 antagonist; or, vehicle (n = 11). Hyperglycemic clamps were employed following injection, providing an index of secretory capacity of pancreatic β-cells. Acute treatment with darifenacin and ketanserin significantly decreased insulin response to glucose challenge as compared to controls, which was confirmed in the darifenacin group by reduced C-peptide levels. Treatment with raclopride resulted in an increased insulin response and a strong tendency to increased C-peptide levels. H 1 blockade did not result in effects on insulin or C-peptide. Results suggest that the effects of antipsychotics on glucose dysregulation may be related to direct inhibitory effects of muscarinic (M 3) and serotonergic (5HT 2) antagonism on insulin secretion. Based on the expression of D 2-like receptors in β-cells, which mediate inhibition of insulin secretion, we propose that prolonged D 2 blockade with antipsychotics may predispose to depletion of insulin stores and an eventual defect in pancreatic compensation.

Targeting PIM kinase activity significantly augments the efficacy of cytarabine

Targeting PIM kinase activity significantly augments the efficacy of cytarabine

Results of toxicology studies with MPC-3100, an oral HSP90 inhibitor.

e13016 Background: MPC-3100, an orally bioavailable synthetic inhibitor of HSP90, has demonstrated efficacy in animal models and is currently in a phase I clinical study in cancer patients. Toxicology studies were conducted to support the long term safety of MPC-3100. Methods: MPC-3100 was administered to rats daily by gavage at 50, 100, or 200 mg/kg for 28 consecutive days or at 25, 50, or 100 mg/kg for 117 days. In cynomolgus monkeys, MPC-3100 was given daily at 10, 25, or 50/35 mg/kg for 28 days or at 6.25, 12.5, or 25 mg/kg for 113 days. Endpoints included weight gain, food consumption, clinical chemistries, hematology, urinalysis, pathologic, and histopathologic evaluation. ECGs were performed on monkeys and ophthalmoscopic examinations were conducted on all animals. Results: Daily doses of 200 mg/kg for 28 days or 100 mg/kg for 117 days exceeded the maximum tolerated dose in rats. Clinical observations were limited to gastrointestinal effects. Generalized lymphoid depletion, mild to moderate hepatobiliary effects, mild changes in hematology, electrolytes, AST/ALT, and changes in the nonglandular stomach and intestine were noted at doses ≥100 mg/kg/day. Toxicity was greater in males. All of the observations were reversible with cessation of treatment. The no observable adverse effect level (NOAEL) after 28 or 117 days was 100 and 50 mg/kg/day, respectively. In monkeys, mortality was noted following 4 days of treatment at 50 mg/kg and 20 days of treatment with dose reduction to 35 mg/kg. Inappetance and diarrhea were associated with gastrointestinal effects. Additional effects were lymphoid depletion, decreased erythrocytes, hemoglobin, hematocrit, and mild changes in electrolytes. Reticulocytes tended to be higher. There were no drug-related effects on clinical pathology parameters at doses up to 25 mg/kg for 113 days or changes to qualitative or quantitative ECG parameters in either study. The NOAEL was 25 or 12.5 mg/kg/day for 28 or 113 days of administration. There were no ocular findings in rats or monkeys. Conclusions: Long term administration of MPC-3100 to rats or monkeys at high doses may result in lymphoid depletion and mild changes in hematology and/or electrolytes. All adverse effects appeared to be reversible upon cessation of treatment.

Phase I safety, pharmacokinetic and pharmacodynamic trial of BMS-599626 (AC480), an oral pan-HER receptor tyrosine kinase inhibitor, in patients with advanced solid tumors.

ABSTRACT Purpose We studied the safety, tolerability, and recommended dose of BMS-599626, an orally bioavailable inhibitor of the human epidermal growth factor receptor (HER) family of receptor tyrosine kinases. Patients and methods Patients with advanced solid tumors that expressed epidermal growth factor receptor (EGFR) and/or HER-2 were recruited and enrolled in a phase I, open-label, dose escalation trial of oral BMS-599626 starting at 100 mg/day given once daily for at least 28 days. Results Forty-five patients received BMS-599626 (100–660 mg/day). Dose-limiting toxic effects were reported at 660 mg/day (grade 3 elevation of hepatic transaminases [two patients] and QTc interval prolongation [one patient]), therefore the recommended maximum tolerated dose was 600 mg/day. The most frequent drug-related toxic effects were diarrhea (30% of patients), anorexia (13%), asthenia (30%), and cutaneous toxic effects, including skin rash (30%). Pharmacokinetic analysis demonstrated Cmax and exposure to BMS-599626 in patients increased with dose. Eleven patients had stable disease and received BMS-599626 for ≥4 months. Serial skin and tumor biopsies taken before and after treatment revealed expected changes in pharmacodynamic biomarkers, indicating that the EGFR and HER-2 pathways were affected. Positron emission tomography imaging showed a metabolic response in 2 of 10 patients evaluated. Conclusion BMS-599626 was generally well tolerated, with disease stabilization across a range of tumor types and doses.

Repeat-Dose Toxicology Evaluation in Cynomolgus Monkeys of AVI-4658, a Phosphorodiamidate Morpholino Oligomer (PMO) Drug for the Treatment of Duchenne Muscular Dystrophy

AVI-4658 is a phosphorodiamidate morpholino oligomer (PMO) drug designed to restore dystrophin expression in a subset of patients with Duchenne muscular dystrophy (DMD). Previous reports demonstrated this clinical proof-of-principle in patients with DMD following intramuscular injection of AVI-4658. This preclinical study evaluated the toxicity and toxicokinetic profile of AVI-4658 when administered either intravenously (IV) or subcutaneously (SC) to cynomolgus monkeys once weekly over 12 weeks, at doses up to the maximum feasible dose of 320 mg/kg per injection. No drug-related effects were noted on survival, clinical observations, body weight, food consumption, opthalmoscopic or electrocardiographic evaluations, hematology, clinical chemistry, urinalysis, organ weights, and macroscopic evaluations. Drug-related microscopic renal effects were dose-dependent, apparently reversible, and included basophilic granules (minimal), basophilic tubules (minimal to moderate), and tubular vacuolation (minimal to mild). These data establish the tolerability of AVI-4658 at doses up to and including the maximum feasible dose of 320 mg/kg by IV bolus or SC injection.

HIV infection, body composition changes and related metabolic complications: contributing factors and evolving management strategies

Metabolic toxicities in HIV patients are common and contribute to clinical status and long-term sequelae. Body fat mass alterations, of multifactorial causes, continue to occur, despite use of antiretroviral drugs associated with fewer metabolic side-effects. The role of HIV itself in the development of these changes is being better defined and a deeper understanding of perturbations in intermediary metabolic processes is emerging. Treatment options are also being identified. HIV itself may be a direct causal factor in the accelerated atherosclerosis and decreased levels of high-density lipoprotein that occur and contribute to increased cardiovascular complications. Antiretroviral drug-related and inflammation-related effects can cause mitochondrial toxicity and are an emerging area of research. The association of increased visceral adipose tissue with both drug-related and chronic inflammation-related factors is now better understood. The role of accelerated aging as a paradigm is useful to understand long-term outcome risks for patients. The use of growth hormone-releasing factor as a viable treatment option for increased visceral abdominal tissue has recently been confirmed for selected patients. Metabolic issues persist in HIV patients who are otherwise stable. Understanding the various inter-related contributing factors has allowed for rapid improvement in patients' clinical status, but long-term consequences are of concern and require ongoing investigation in order to prevent limiting the otherwise important clinical achievements that have recently occurred.

Safety and Toxicology of Cyclosporine in Propylene Glycol after 9-Month Aerosol Exposure to Beagle Dogs

Cyclosporine inhalation solution (CIS) delivered via nebulization is under evaluation for the prevention of chronic rejection post-lung transplant. A 300-patient randomized, controlled clinical trial (CYCLIST) is expected to be completed late in 2011. In support of this trial, a chronic inhalation toxicology study in dogs has been completed. To mimic the clinical setting, animals (four/sex/dose plus two/sex/dose in the control and high dose recovery groups) were exposed to aerosolized CIS, via nose-only exposure, three times per week for 9 months at targeted inhaled doses of 0 (air), 4, 12, and 24 mg/kg. In addition, the potential for persistence or reversibility of any toxic effects were assessed after a 6-week recovery period. The toxicological endpoints included clinical observations, body-weight, food consumption, toxicokinetics, clinical chemistry, and histopathology. All dogs receiving CIS completed the study with the only consistent observations being excessive salivation and changes in minute ventilation. There was no limiting lung or systemic toxicity associated with exposure to CIS, and the only possible drug-related effect was an observation of benign fibroadenoma tissue in the mammary glands of the high-dose female recovery group. Toxicokinetic data showed that cyclosporine is initially absorbed rapidly with little drug remaining in lung tissue or blood 24 h after the end of dosing. The study supports the pulmonary and systemic safety of aerosolized CIS at expected lung dose levels/kg of up to 12 times greater than the average dose patients are receiving in the CYCLIST trial.

Multicenter Independent Assessment of Outcomes in Chronic Myeloid Leukemia Patients Treated With Imatinib

Imatinib slows development of chronic myeloid leukemia (CML). However, available information on morbidity and mortality is largely based on sponsored trials, whereas independent long-term field studies are lacking. Consecutive CML patients who started imatinib treatment before 2005 and who were in complete cytogenetic remission (CCyR) after 2 years (± 3 months) were eligible for enrollment in the independent multicenter Imatinib Long-Term (Side) Effects (ILTE) study. Incidence of the first serious and nonserious adverse events and loss of CCyR were estimated according to the Kaplan-Meier method and compared with the standard log-rank test. Attainment of negative Philadelphia chromosome hematopoiesis was assessed with cytogenetics and quantitative polymerase chain reaction. Cumulative incidence of death related or unrelated to CML progression was estimated, accounting for competing risks, according to the Kalbleisch-Prentice method. Standardized incidence ratios were calculated based on population rates specific for sex and age classes. Confidence intervals were calculated by the exact method based on the χ(2) distribution. All statistical tests were two-sided. A total of 832 patients who were treated for a median of 5.8 years were enrolled. There were 139 recorded serious adverse events, of which 19.4% were imatinib-related. A total of 830 nonserious adverse events were observed in 53% of patients; 560 (68%) were imatinib-related. The most frequent were muscle cramps, asthenia, edema, skin fragility, diarrhea, tendon, or ligament lesions. Nineteen patients (2.3%) discontinued imatinib because of drug-related toxic effects. Forty-five patients lost CCyR, at a rate of 1.4 per 100 person-years. Durable (>1 year) negative Philadelphia chromosome hematopoiesis was attained by 179 patients. Twenty deaths were observed, with a 4.8% mortality incidence rate (standardized incidence ratio = 0.7; 95% confidence interval = 0.40 to 1.10, P = .08), with only six (30%) associated with CML progression. In this study, CML-related deaths were uncommon in CML patients who were in CCyR 2 years after starting imatinib, and survival was not statistically significantly different from that of the general population.

Prospective memory functioning among ecstasy/polydrug users: evidence from the Cambridge Prospective Memory Test (CAMPROMPT)

Prospective memory (PM) deficits in recreational drug users have been documented in recent years. However, the assessment of PM has largely been restricted to self-reported measures that fail to capture the distinction between event-based and time-based PM. The aim of the present study is to address this limitation. Extending our previous research, we augmented the range laboratory measures of PM by employing the CAMPROMPT test battery to investigate the impact of illicit drug use on prospective remembering in a sample of cannabis only, ecstasy/polydrug and non-users of illicit drugs, separating event and time-based PM performance. We also administered measures of executive function and retrospective memory in order to establish whether ecstasy/polydrug deficits in PM were mediated by group differences in these processes. Ecstasy/polydrug users performed significantly worse on both event and time-based prospective memory tasks in comparison to both cannabis only and non-user groups. Furthermore, it was found that across the whole sample, better retrospective memory and executive functioning was associated with superior PM performance. Nevertheless, this association did not mediate the drug-related effects that were observed. Consistent with our previous study, recreational use of cocaine was linked to PM deficits. PM deficits have again been found among ecstasy/polydrug users, which appear to be unrelated to group differences in executive function and retrospective memory. However, the possibility that these are attributable to cocaine use cannot be excluded.

Economic considerations of antifungal prophylaxis in patients undergoing surgical procedures

Fungi are a frequent cause of nosocomial infections, with an incidence that has increased significantly in recent years, especially among critically ill patients who require intensive care unit (ICU) admission. Among ICU patients, postsurgical patients have a higher risk of Candida infections in the bloodstream. In consideration of the high incidence of fungal infections in these patients, their strong impact on mortality rate, and of the difficulties in Candida diagnosis, some experts suggest the use of antifungal prophylaxis in critically ill surgical patients. A clinical benefit from this strategy has been demonstrated, but the economic impact of the use of antifungal prophylaxis in surgical patients has not been systematically evaluated, and its cost–benefit ratio has not been defined. Whereas the costs associated with treating fungal infections are very high, the cost of antifungal drugs varies from affordable (ie, the older azoles) to expensive (ie, echinocandins, polyenes, and the newer azoles). Adverse drug-related effects and the possibly increased incidence of fluconazole resistance and of isolates other than Candida albicans must also be taken into account. From the published studies of antifungal prophylaxis in surgical patients, a likely economic benefit of this strategy could be inferred, but its usefulness and cost–benefits should be evaluated in light of local data, because the available evidence does not permit general recommendations.

Formal adult infectious disease specialist consultations in the outpatient setting at a comprehensive cancer center (1998–2008): Diverse and impactful

The literature on the impact of infectious disease (ID) consulations in the outpatient treatment of cancer is scarce. The medical records of consecutive adult patients with cancer formally evaluated by two board-certified ID specialists in an outpatient setting at our institution over a 10-year period (1998-2008) were reviewed retrospectively. The patients' demographics, referring departments, purposes for consultation, ID specialist recommendations, and overall impact of consultations on outcome were analyzed. We identified 598 patients who underwent ID specialist consultations. Most of them had solid tumors (53%), predominantly breast cancer, whereas non-Hodgkin's lymphoma was the most common hematologic malignancy. Almost half of the patients (45%) had active malignancies, but few of them were severely neutropenic (8%) or had been receiving high doses of corticosteroids (17%). The most frequent requests for consultation were culture or serologic test (15%), and treatment of cellulitis and/or surgical wound infections (14%). Of 337 isolated pathogens, the most prevalent were methicillin-resistant Staphylococcus aureus (13%) and Pseudomonas aeruginosa (8%), as well as atypical mycobacteria (16%) and Aspergillus species (11%). ID specialists provided alternative diagnoses in 53% of the cases, including identification of a different infection (46%), a noninfectious etiology (29%), colonization (16%), and drug-related toxic effects (9%). Overall, we deemed the contribution of the ID specialist to be significant in 62% of the consultations. ID specialists contribute significantly to the outpatient care of individuals with cancer.

Resveratrol reduces myofibroblast arrhythmogenicity

Background: Among grape skin polyphenols, trans-resveratrol (RES) has been reported to slow the development of cardiac fibrosis and to affect myofibroblast (MFB) differentiation. Because MFBs induce slow conduction and ectopic activity following heterocellular gap junctional coupling to cardiomyocytes, we investigated whether RES and its main metabolites affect arrhythmogenic cardiomyocyte-MFB interactions. Methods: Experiments were performed with patterned growth strands of neonatal rat ventricular cardiomyocytes coated with cardiac MFBs. Impulse propagation characteristics were measured optically using voltage-sensitive dyes. Long-term video recordings served to characterize drug-related effects on ectopic activity. Data are given as means ± S.D. (n = 4–20). Results: Exposure of pure cardiomyocyte strands to RES at concentrations up to 10 µmol/L had no significant effects on impulse conduction velocity (θ) and maximal action potential upstroke velocities (dV/dtmax). By contrast, in MFB-coated strands exhibiting slow conduction, RES enhanced θ with an EC50 of ~10 nmol/L from 226 ± 38 to 344 ± 24 mm/s and dV/dtmax from 48 ± 7 to 69 ± 2%APA/ms, i.e., to values of pure cardiomyocyte strands (347 ± 33 mm/s; 75 ± 4%APA/ms). Moreover, RES led to a reduction of ectopic activity over the course of several hours in heterocellular preparations. RES is metabolized quickly in the body; therefore, we tested the main known metabolites for functional effects and found them similarly effective in normalizing conduction with EC50s of ~10 nmol/L (3-OH-RES), ~20 nmol/L (RES-3-O-β-glucuronide) and ~10 nmol/L (RES-sulfate), respectively. At these concentrations, neither RES nor its metabolites had any effects on MFB morphology and α-smooth muscle actin expression. This suggests that the antiarrhythmic effects observed were based on mechanisms different from a change in MFB phenotype. Conclusions: The results demonstrate that RES counteracts MFB-dependent arrhythmogenic slow conduction and ectopic activity at physiologically relevant concentrations. Because RES is rapidly metabolized following intestinal absorption, the finding of equal antiarrhythmic effectiveness of the main RES metabolites warrants their inclusion in future studies of potentially beneficial effects of these substances on the heart.

Impact of iris pigment and pupil size in ultraviolet radiation cataract in rat

To investigate the effect of iris pigment and pupil size in ultraviolet radiation (UVR)-induced cataract. Brown-Norway rats (pigmented) and Fischer-344 rats (non-pigmented) were unilaterally exposed in vivo to 5 kJ/m(2) UVR. Each strain was split into two groups, each receiving either mydriatic (tropicamide) or miotic (pilocarpine) eye-drops. One week after exposure, the degree of ocular inflammation and damage in the anterior segment was determined. The lenses were extracted, photographed and the degree of forward light scattering (cataract) was quantified. The cataract types differed between the two strains. All Fischer rats developed macroscopically identifiable UVR cataract while only 41% of Brown-Norway rats did so. All groups except the miotic Brown-Norway developed significant light scattering. The Fischer rats developed 3-4-fold more lens light scattering than the Brown-Norway rats. The miotic Fischer group exhibited significantly more light scattering than the mydriatic Fischer group. There was no significant difference in light scattering between the two Brown-Norway groups. There was a correlation between ocular inflammation and degree of light scattering, with Brown-Norway rats exhibiting less inflammation and lens light scattering. Pigmented rats develop less UVR cataract and less ocular inflammation than non-pigmented rats. Pupil size plays a smaller role in UVR cataract development in pigmented rats than in non-pigmented. The role of UVR-induced ocular inflammation in cataract development is still ambiguous.

Pneumopathie interstitielle induite par la mésalazine

We report the case of a 57-year-old woman with ulcerative colitis since eight years who developed a diffuse interstitial pneumonia linked to mesalazine (oral and enemas). The adverse drug-related effect to mesalazine was strongly suggested regarding improvement upon discontinuation and relapse after reinstitution of mesalazine. To date, after 8 years, the patient has not any respiratory symptom which is another argument for the adverse drug-related effect to mesalazine.

Action of tacrolimus on Wistar rat kidneys implanted with Walker 256 carcinosarcoma

To evaluate the development of Walker 256 tumor in male Wistar rats treated with tacrolimus using an experimental kidney tumor model. 40 male Wistar rats were divided into four groups: Tumor group (TU) (n=10), Tacrolimus-Tumor group (TT) (n=10), Tacrolimus group (TC) (n=10) and Control group (C) (n=10). Treatment with tacrolimus was performed in groups TT and TC. Under anesthesia, the right kidney of each animal of TU and TT was accessed through a supraumbilical incision and inoculated with a 0.1 mL solution containing 2 x 10(6) tumor cells (Walker 256 carcinosarcoma tumor cells). Group TC was treated with a saline solution. All the animals of groups TC and TT were treated with tacrolimus (5mg/kg/day) by gavage for 15 days. TU group animals received saline by gavage for 15 days. On the 15th postoperative day, all animals were submitted to euthanasia and blood sampling for analysis of serum creatinine (Cr) and blood urea nitrogen (BUN). Abdominal gross examination was performed, the right kidney removed and prepared for histological analysis by hematoxylin-eosin staining. The resulting data were submitted to statistical analysis by ANOVA. Statistical significance was found when comparing creatinine level between groups TU, TT and TC -TT group culminated with a marked increased in creatinine levels (Cr=1.013 + or - 0.3028 mg/mL), TU group (Cr=0.5670 + or - 0.03536 mg/dL) P=0.00256, TC group (Cr =0.711 + or - 0.1653 mg/mL) P= 0.02832. Statistical significance was found when comparing BUN levels in TT group (71.32 + or - 17.14 mg/mL), compared with TU group (45.83 + or - 5.046 mg/dL), P=0.000318. There were no statistically significant differences between groups TT and TC (61.23 + or - 9.503 mg/mL) P=0.7242. Histological analysis showed a poor evolution in TT group with multiple foci of hemorrhage and cortical invasion by the Walker tumor. The Tacrolimus-treated group developed a more aggressive tumor and a drug-related nephrotoxic effect.