Bioequivalence of a New Pediatric Paracetamol Oral Suspension Compared With a Marketed Formulation in Healthy Adults: A Randomized, Open-Label Study.

Background: A new oral paracetamol formulation with the same paracetamol quantity (24 mg/mL) as a marketed formulation but with finer active ingredient particle size and lower amounts of maltitol (5.85 g/dose in the test formulation vs 7.25 g/dose in the reference formulation) and sorbitol (2.4 g/dose vs 2.83 g/dose) was developed. Objective: Establish the bioequivalence of the new pediatric formulation (test treatment) compared with the marketed formulation (reference treatment). Methods: This Phase I, open-label trial assigned healthy adult volunteers to a single 42-mL (1 g para-cetamol) dose of test or reference treatment. Participants received both treatments in a randomized order separated by a 72-hour washout period. The primary endpoints were AUC0-tlast (AUC vs time curve from time 0 to last measurable sampling timepoint), Cmax, and tmax. Safety assessments included adverse event, clinical laboratory, and physical examination data. Results: Thirty-five participants were randomized and treated. The study population was 42.9% women (57.1% men) with a median age of 30 years; most participants were non-Hispanic White. Mean Cmax values were comparable between test and reference products, with a median tmax of 1.00 hour for both. The test/reference ratios (%) (90% CI) for AUC0-tlast and Cmax were 98.69% (96.46, 100.97) and 100.73% (95.63, 106.10), respectively. There were no adverse events or deaths. Conclusions: The new paracetamol formulation is bioequivalent to the marketed formulation.

Unraveling the palindromic and nonpalindromic motifs of retroviral integration site sequences by statistical mixture models.

A weak palindromic nucleotide motif is the hallmark of retroviral integration site alignments. Given that the majority of target sequences are not palindromic, the current model explains the symmetry by an overlap of the nonpalindromic motif present on one of the half-sites of the sequences. Here, we show that the implementation of multicomponent mixture models allows for different interpretations consistent with the existence of both palindromic and nonpalindromic submotifs in the sets of integration site sequences. We further show that the weak palindromic motifs result from freely combined site-specific submotifs restricted to only a few positions proximal to the site of integration. The submotifs are formed by either palindrome-forming nucleotide preference or nucleotide exclusion. Using the mixture models, we also identify HIV-1-favored palindromic sequences in Alu repeats serving as local hotspots for integration. The application of the novel statistical approach provides deeper insight into the selection of retroviral integration sites and may prove to be a valuable tool in the analysis of any type of DNA motifs.

Selected Risk Nutritional Factors for Chemotherapy-Induced Polyneuropathy.

The present study seeks to identify the nutritional risk factors involved in the development of neuropathies induced by chemotherapeutic treatments. Unlike the gastrointestinal or hematological adverse effects of chemotherapy there is no protective treatment strategy for polyneuropathy. The aim of this study was to find possible deficiencies in nutritional factors, which can be used for supplementation in the future for prevention of chemotherapy-induced neuropathy development. We analyzed 70 patients undergoing paclitaxel chemotherapy and evaluated the risk factors involved in chemotherapy-induced peripheral neuropathy (CIPN). Several risk factors were considered in the development of CIPN, including deficiency of vitamin B1, B6, and D and fatty acids. The occurrence of CIPN complication in 60% cases was observed. We found significant differences in vitamin D and saturated fatty acid concentration. Vitamin D levels in the group without CIPN were estimated to be 38.2 (24.95, 47.63) nmol/L, whereas in the group with CIPN it was determined to be 25.6 (19.7, 32.55) nmol/L, p = 0.008. The level of total saturated fatty acids in the group without CIPN was of 32.613 Area % (31.322; 36.262), whereas in the group with CIPN it was of 34.209 Area % (32.86; 39.386), p = 0.01. The obtained results suggest a diet lower in saturated fatty acid content during chemotherapy. The most significant finding was that supplementation of vitamin D before chemotherapy could be an efficient neuroprotective in CIPN prophylaxis, as significantly lower levels 25OH derivative of vitamin D were observed in the CIPN group throughout the study period.

Rapid and clinically significant response to masitinib in the treatment of mucosal primary esophageal melanoma with somatic KIT exon 11 mutation involving brain metastases: A case report.

BACKGROUND: Malignant melanoma in the gastrointestinal tract may be primary or metastatic. Mucosal melanoma is a quite rare and aggressive disease, growing hidden and diagnosed with a certain delay which makes treatment difficult. CASE REPORT: The authors present the first patient with c-kit exon 11 mutated primary esophageal melanoma treated with oral tyrosine kinase inhibitor masitinib. A 55-year-old-man presented with esophageal melanoma metastising into visceral organs and to the brain. The patient showed objective and clinical significant therapeutic response to masitinib. After initiation of masitinib, dysphagia and odynophagia disappeared within 1 week. Following 1 month of treatment, computed tomography showed a regression in the number and size of brain metastatic lesions and regression in visceral lesions. This therapeutic response, despite the aggressive disease on treatment initiation, effectively enabled the patient to have 6 months of quality life. CONCLUSION: This report corroborates the plausibility of treating advanced melanoma carrying a mutation of KIT with masitinib. It also raises the question of masitinib treatment beyond progression. Additionally, the observed masitinib treatment effect on the brain suggests accumulation of therapeutically relevant concentration of masitinib in the central nervous system. This observation has possible ramifications for treatment of intracranial neoplasms.

Kinetically guided neoadjuvant chemoradiotherapy based on 5-Fluorouracil in patients with locally advanced rectal cancer.

BACKGROUND AND PURPOSE: This study estimated patients' early response following neoadjuvant chemoradiotherapy (CHRT) of locally advanced rectal cancer based on 5-fluorouracil (5-FU). The target was to achieve pathological complete response (pCR; residual disease-free stage) and toxicities of grade ≤2, using individual dosing predicted according to the steady-state plasma concentration (C ss) and pharmacokinetic parameters of 5-FU: the area under the time-concentration curve at steady state (AUC) and clearance (CL). PATIENTS AND METHODS: This open-label prospective study enrolled 33 adult patients treated with 5-FU administered as a continuous intravenous infusion over 4-5 weeks, as follows: in Group 1a (N = 6), the patients received a standard dose of 300 mg/m(2)/24 h. In Group 1b (N = 7), the patients were treated with an escalated dose of 400-1,000 mg/m(2)/24 h. In Group 2 (N = 20), the patients were given dosing kinetically guided in order to reach the target range of 5-FU C ss 50-100 µg/L. Tolerability was tested according to Common Terminology Criteria for Adverse Events v3.0 (CTCAE). Radiotherapy was delivered with 10-15 MV photon beams at 1.8 Gy/fraction up to 50.4 Gy in 28 daily fractions for 5 days a week. Surgery followed 4-6 weeks after the completion of CHRT and clinical restaging. The pCR and residual tumour stage were evaluated using preoperative tumour downstaging in magnetic resonance, postoperative histopathological staging and tumour regression rate (residual disease). RESULTS AND CONCLUSION: The cumulative AUC of 5-FU (total exposure to the drug) correlated with cumulative 5-FU dose (r = 0.61; p < 0.001) and residual disease (r s = -0.53; p < 0.005). A higher target pCR rate was reached in patients individually treated (Group 2) who finished the whole 5-week CHRT. The individual daily dose needed to reach the target C ss should be >350 mg/m(2) (up to 600 mg/m(2)) provided that 5-FU metabolic ratio is within the range of 2.5-6 and the cumulative AUC5wks is within 50-100 mg·h/L.

Predictors of irinotecan toxicity and efficacy in treatment of metastatic colorectal cancer.

The colorectal cancer ranks high among the malignant tumours in incidence and mortality and irinotecan is standardly used in palliative treatment of metastatic disease in every therapeutic line. Unfortunately, the treatment with irinotecan is often associated with severe toxicities, especially neutropenia and diarrhea. The majority of the toxic manifestation is caused by the insufficient deactivation (glucuronidation) of irinotecan active metabolite SN-38 by UGT1A enzyme. The elevated SN-38 plasma concentration is responsible for the hematological and gastrointestinal toxicity that can become life-threatening. The patients carrying the mutation of the gene encoding UGT1A enzyme lack the ability of bilirubin glucuronidation, and suffer from the inherited un-conjugated hyperbilirubinemia (Gilbert syndrome, Crigler-Najjar type 1 and 2 syndrome). The mutations in other enzyme systems also play role in the etiopathogenesis of the irinotecan toxicity: CYP3A (cytochrome P-450), ABC family of transmembrane transporters (adenosine-triphosphate binding cassette). The goal of the contemporary research is to determine the predictive factors that will enable the individual adjustment of the individual drug dosage while minimising the adverse effects and maintaining the treatment benefit.

Computer-aided evaluation of screening mammograms based on local texture models.

We propose a new approach to diagnostic evaluation of screening mammograms based on local statistical texture models. The local evaluation tool has the form of a multivariate probability density of gray levels in a suitably chosen search window. First, the density function in the form of Gaussian mixture is estimated from data obtained by scanning of the mammogram with the search window. Then we evaluate the estimated mixture at each position and display the corresponding log-likelihood value as a gray level at the window center. The resulting log-likelihood image closely correlates with the structural details of the original mammogram and emphasizes unusual places. We assume that, in parallel use, the log-likelihood image may provide additional information to facilitate the identification of malignant lesions as atypical locations of high novelty.

Iterative principles of recognition in probabilistic neural networks.

When considering the probabilistic approach to neural networks in the framework of statistical pattern recognition we assume approximation of class-conditional probability distributions by finite mixtures of product components. The mixture components can be interpreted as probabilistic neurons in neurophysiological terms and, in this respect, the fixed probabilistic description contradicts the well known short-term dynamic properties of biological neurons. By introducing iterative schemes of recognition we show that some parameters of probabilistic neural networks can be "released" for the sake of dynamic processes without disturbing the statistically correct decision making. In particular, we can iteratively adapt the mixture component weights or modify the input pattern in order to facilitate correct recognition. Both procedures are shown to converge monotonically as a special case of the well known EM algorithm for estimating mixtures.

Azole antimycotics differentially affect rifampicin-induced pregnane X receptor-mediated CYP3A4 gene expression.

Azole antifungal drug ketoconazole has recently been demonstrated as an inhibitor of a ligand-induced pregnane X receptor (PXR)-mediated transcriptional regulation of the CYP3A4 gene through disruption of PXR interaction with steroid receptor coactivator (SRC)-1. In contrast, other clotrimazole-derived antifungal agents are known as potent inducers of CYP3A4 through PXR. In the present study, we examined effects of azole antimycotics clotrimazole, ketoconazole, econazole, oxiconazole, miconazole, fluconazole, and itraconazole on PXR-mediated expression of CYP3A4. We investigated individual effects of the tested azoles as well as their action on rifampicin-induced PXR-mediated transactivation and expression of CYP3A4 in LS174T cell line and primary human hepatocytes, their interactions with PXR ligand-binding domain, and azole-mediated recruitment of SRC-1 to PXR. In addition, applying the pharmacodynamic approach and dose-response analysis, we aimed to describe the nature of potential interactions of tested azole antimycotics coadministered with a prototypical PXR ligand rifampicin in transactivation of CYP3A4 gene. We describe additive and antagonistic interactions of partial and full agonists of PXR nuclear receptor in the therapeutic group of azole antimycotics in rifampicin-mediated transactivation of CYP3A4. We show that oxiconazole is a highly efficacious activator of CYP3A4 transactivation, which could be antagonized by rifampicin in a competitive manner. In addition, we show that activation of the CYP3A4 promoter is a complex process, which is not exclusively determined by azole-PXR interactions, and we suggest that the ability of some azoles to affect recruitment of SRC-1 to PXR modulates their net effects in transactivation of CYP3A4 both in the absence or presence of rifampicin.

Pharmacokinetics and pharmacodynamics of methotrexate in non-neoplastic diseases.

Low dose pulse methotrexate (LDMTX) therapy has become effective in the treatment of autoimmune and lymphoproliferative diseases. The pharmacokinetics of LDMTX is individually highly variable, resulting in a different systemic exposure to the drug and a variable therapeutic/toxic effect in patients. The improvements and exacerbations of disease activity in relation to the introductions and discontinuations of LDMTX therapy suggest the possible immunosuppresive and anti-inflammatory properties of the drug. Because of a strong correlation between the drug pharmacokinetics and the therapeutic outcomes (pharmacodynamics), it seems to be possible to individualise the LDMTX therapy according to the results of pharmacokinetic/pharmacodynamic analysis. In the case of psoriasis, pharmacokinetic/pharmacodynamic analysis in our local study revealed a highly significant inverse relationship between PASI (expressed as a percent of the initial value) and a steady-state AUC(MTX) (area under the curve of methotrexate plasma concentrations; r(8) = -0.65, p < 0.001). The considerable inter-individual variability and low intra-individual variability in MTX pharmacokinetics, supports a role for therapeutic monitoring and dose individualisation at the start of pharmacotherapy. The results of this study suggest that a steady-state AUC(MTX) value of 700 nmol x h/L and higher are associated with a significantly better success rate of antipsoriatic therapy than lower values. The preliminary results in our follow-up study suggest the statistically higher incidence of unwanted effects depending on maximum plasma concentration of the drug. Moreover, statistically significant correlation was found between the toxic effects and exposure to the drug regarding methotrexate plasma concentrations and intracellular storage in erythrocytes. However, the data are still in the process of being completed and are not yet published.