Population Pharmacokinetics of Methylphenidate in Healthy Adults Emphasizing Novel and Known Effects of Several Carboxylesterase 1 (<i>CES1</i>) Variants

The aim of this study was to identify demographic and genetic factors that significantly affect methylphenidate (MPH) pharmacokinetics (PK), and may help explain interindividual variability and further increase the safety of MPH. d‐MPH plasma concentrations, demographic covariates, and carboxylesterase 1 (CES1) genotypes were gathered from 122 healthy adults and analyzed using nonlinear mixed effects modeling. The structural model that best described the data was a two‐compartment disposition model with absorption transit compartments. Novel effects of rs115629050 and CES1 diplotypes, as well as previously reported effects of rs71647871 and body weight, were included in the final model. Assessment of the independent and combined effect of CES1 covariates identified several specific risk factors that may result in severely increased d‐MPH plasma exposure

Pharmacokinetics and Safety of Prolonged Paracetamol Treatment in Neonates: An Interventional Cohort Study

Aims To investigate the pharmacokinetics and safety of prolonged paracetamol use (\u3e72 h) for neonatal pain. Methods Neonates were included if they received paracetamol orally or intravenously for pain treatment. A total of 126 samples were collected. Alanine aminotransferase and bilirubin were measured as surrogate liver safety markers. Paracetamol and metabolites were measured in plasma. Pharmacokinetic parameters for the parent compound were estimated with a nonlinear mixed-effects model. Results Forty-eight neonates were enrolled (38 received paracetamol for \u3e72 h). Median gestational age was 38 weeks (range 25–42), and bodyweight at inclusion was 2954 g (range 713–4750). Neonates received 16 doses (range 4–55) over 4.1 days (range 1–13.8). The median (range) dose was 10.1 mg/kg (2.9–20.3). The median oxidative metabolite concentration was 14.6 μmol/L (range 0.12–113.5) and measurable \u3e30 h after dose. There was no significant difference (P \u3e .05) between alanine aminotransferase and bilirubin measures at \u3c72 h or \u3e72 h of paracetamol treatment or the start and end of the study. Volume of distribution and paracetamol clearance for a 2.81-kg neonate were 2.99 L (% residual standard error = 8, 95% confidence interval 2.44–3.55) and 0.497 L/h (% residual standard error = 7, 95% confidence interval 0.425–0.570), respectively. Median steady-state concentration from the parent model was 50.3 μmol/L (range 30.6–92.5), and the half-life was 3.55 h (range 2.41–5.65). Conclusion Our study did not provide evidence of paracetamol-induced liver injury nor changes in metabolism in prolonged paracetamol administration in neonates

Correlation between relative rates of hospital treatment or death due to ischaemic heart disease (IHD) and of IHD-related medication among socio-occupational and economic activities groups in Denmark, 1996–2005

Objective: The aim of the present work was to establish whether or not prescribed medication is a usable risk indicator for work‑related ischaemic heart disease (IHD), in Denmark. Material and Methods: Weighted Spearman rank correlation coefficients (rho) were used to evaluate the agreement between Standardised Hazard Ratios (SHR) for hospital treatment or death due to IHD and SHR for purchase of prescriptions for medicine that may prevent IHD from (re)occurring, among socio-occupational and economic activities groups in Denmark. The SHR were based on a 10-year prospective follow-up of 2 million people in Danish national registers 1996–2005. Results: We found approximately 7 times more cases of medicine usage (N = 411 651) than we did for hospital treatment or death (N = 55 684). The correlations between the 2 types of SHR were strong (rho = 0.94 for the socio-occupational groups; rho = 0.74 for the economic activities groups). We observed, however, one markedly contradictive result; the industrial group entitled ‘general practitioner, dentists etc.’ was associated both with significantly high rates of medicine usage (SHR = 1.15, 95% CI: 1.12–1.19) and significantly low rates of hospital treatment or death due to IHD (SHR = 0.80, 95% CI: 0.71–0.91). Conclusion: Apart from a few caveats, the strong correlations obtained in the present study signify that purchase of a prescription for IHD-related medication is a usable risk indicator for IHD in the working population of Denmark. The usage of medicine data in addition to or instead of the use of death or hospital data in epidemiological studies on work-related IHD risk will bring about a tremendous increase in statistical power

Toll-like receptor 2 expression is decreased on alveolar macrophages in cigarette smokers and COPD patients

BACKROUND: Cigarette smoke exposure including biologically active lipopolysaccharide (LPS) in the particulate phase of cigarette smoke induces activation of alveolar macrophages (AM) and alveolar epithelial cells leading to production of inflammatory mediators. This represents a crucial mechanism in the pathogenesis of chronic obstructive pulmonary disease (COPD). Respiratory pathogens are a major cause of exacerbations leading to recurrent cycles of injury and repair. The interaction between pathogen-associated molecular patterns and the host is mediated by pattern recognition receptors (PRR's). In the present study we characterized the expression of Toll-like receptor (TLR)- 2, TLR4 and CD14 on human AM compared to autologous monocytes obtained from patients with COPD, healthy smokers and non-smokers. METHODS: The study population consisted of 14 COPD patients without evidence for acute exacerbation, 10 healthy smokers and 17 healthy non-smokers stratified according to age. The expression of TLR2, TLR4 and CD14 surface molecules on human AM compared to autologous monocytes was assessed ex vivo using FACS analysis. In situ hybridization was performed on bronchoalveolar lavage (BAL) cells by application of the new developed HOPE-fixative. RESULTS: The expression of TLR2, TLR4 and CD14 on AM from COPD patients, smokers and non-smokers was reduced as compared to autologous monocytes. Comparing AM we detected a reduced expression of TLR2 in COPD patients and smokers. In addition TLR2 mRNA and protein expression was increased after LPS stimulation on non-smokers AM in contrast to smokers and COPD patients. CONCLUSION: Our data suggest a smoke related change in the phenotype of AM's and the cellular response to microbial stimulation which may be associated with impairment of host defenses in the lower respiratory tract

Adaptation to acetaminophen exposure elicits major changes in expression and distribution of the hepatic proteome.

Acetaminophen overdose is the leading cause of acute liver failure. One dose of 10-15 g causes severe liver damage in humans, whereas repeated exposure to acetaminophen in humans and animal models results in autoprotection. Insight of this process is limited to select proteins implicated in acetaminophen toxicity and cellular defence. Here we investigate hepatic adaptation to acetaminophen toxicity from a whole proteome perspective, using quantitative mass spectrometry. In a rat model, we show the response to acetaminophen involves the expression of 30% of all proteins detected in the liver. Genetic ablation of a master regulator of cellular defence, NFE2L2, has little effect, suggesting redundancy in the regulation of adaptation. We show that adaptation to acetaminophen has a spatial component, involving a shift in regionalisation of CYP2E1, which may prevent toxicity thresholds being reached. These data reveal unexpected complexity and dynamic behaviour in the biological response to drug-induced liver injury

A phase II study of the vitamin D analogue Seocalcitol in patients with inoperable hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is a common malignant tumour, which has a poor prognosis. Surgical resection can be curative but most patients are inoperable and most chemotherapy agents have minimal activity in this disease. Seocalcitol, a vitamin D analogue, induces differentiation and inhibits growth in cancer cell lines and in vivo. The vitamin D receptor is expressed in hepatocytes and more abundantly in HCC cells. In total, 56 patients with inoperable advanced HCC were included in an uncontrolled study of oral Seocalcitol treatment for up to 1 year ( with possible extension for responders). The dose was titrated according to serum calcium levels. The treatment effect was evaluated by regular CT scans. Out of 33 patients evaluable for tumour response, two had complete response (CR), 12 stable disease and 19 progressive disease. The CRs appeared after 6 and 24 months of treatment, and lasted for 29 and at least 36 months ( patient still in remission when data censored). Seocalcitol was well tolerated; the most frequent toxicity was hypercalcaemia and related symptoms. Most patients tolerated a daily dose of 10 mug of Seocalcitol. This is the first study showing activity, by reduction in tumour dimensions, of a differentiating agent in patients with an advanced bulky, solid tumour. Seocalcitol may have an effect in the treatment of HCC, especially in early disease when a prolonged treatment can be instituted. The survival benefit with or without tumour response should be determined in controlled studies

Prophylactic ciprofloxacin treatment prevented high mortality, and modified systemic and intestinal immune function in tumour-bearing rats receiving dose-intensive CPT-11 chemotherapy

Infectious complications are a major cause of morbidity and mortality from dose-intensive cancer chemotherapy. In spite of the importance of intestinal bacteria translocation in these infections, information about the effect of high-dose chemotherapy on gut mucosal immunity is minimal. We studied prophylactic ciprofloxacin (Cipro) treatment on irinotecan (CPT-11) toxicity and host immunity in rats bearing Ward colon tumour. Cipro abolished chemotherapy-related mortality, which was 45% in animals that were not treated with Cipro. Although Cipro reduced body weight loss and muscle wasting, it was unable to prevent severe late-onset diarrhoea. Seven days after CPT-11, splenocytes were unable to proliferate (stimulation index=0.10±0.02) and produce proliferative and inflammatory cytokines (i.e., Interleukin (IL)-2, interferon-γ (IFN-γ), tumour necrosis factor-α (TNF-α) IL-1β, IL-6) on mitogen stimulation in vitro (P<0.05 vs controls), whereas mesenteric lymph node (MLN) cells showed a hyper-proliferative response and a hyper-production of pro-inflammatory cytokines on mitogen stimulation. This suggests compartmentalised effects by CPT-11 chemotherapy on systemic and intestinal immunity. Cipro normalised the hyper-responsiveness of MLN cells, and in the spleen, it partially restored the proliferative response and normalised depressed production of IL-1β and IL-6. Taken together, Cipro prevented infectious challenges associated with immune hypo-responsiveness in systemic immune compartments, and it may also alleviate excessive pro-inflammatory responses mediating local gut injury

Analysis of SNPs and Haplotypes in Vitamin D Pathway Genes and Renal Cancer Risk

In the kidney vitamin D is converted to its active form. Since vitamin D exerts its activity through binding to the nuclear vitamin D receptor (VDR), most genetic studies have primarily focused on variation within this gene. Therefore, analysis of genetic variation in VDR and other vitamin D pathway genes may provide insight into the role of vitamin D in renal cell carcinoma (RCC) etiology. RCC cases (N = 777) and controls (N = 1,035) were genotyped to investigate the relationship between RCC risk and variation in eight target genes. Minimum-p-value permutation (Min-P) tests were used to identify genes associated with risk. A three single nucleotide polymorphism (SNP) sliding window was used to identify chromosomal regions with a False Discovery Rate of <10%, where subsequently, haplotype relative risks were computed in Haplostats. Min-P values showed that VDR (p-value = 0.02) and retinoid-X-receptor-alpha (RXRA) (p-value = 0.10) were associated with RCC risk. Within VDR, three haplotypes across two chromosomal regions of interest were identified. The first region, located within intron 2, contained two haplotypes that increased RCC risk by approximately 25%. The second region included a haplotype (rs2239179, rs12717991) across intron 4 that increased risk among participants with the TC (OR = 1.31, 95% CI = 1.09–1.57) haplotype compared to participants with the common haplotype, TT. Across RXRA, one haplotype located 3′ of the coding sequence (rs748964, rs3118523), increased RCC risk 35% among individuals with the variant haplotype compared to those with the most common haplotype. This study comprehensively evaluated genetic variation across eight vitamin D pathway genes in relation to RCC risk. We found increased risk associated with VDR and RXRA. Replication studies are warranted to confirm these findings

Identification and Characterisation of Pseudomonas 16S Ribosomal DNA from Ileal Biopsies of Children with Crohn's Disease

Molecular analysis of bacterial 16S rRNA genes has made a significant contribution to the identification and characterisation of bacterial flora in the human gut. In particular, this methodology has helped characterise bacterial families implicated in the aetiology of inflammatory bowel disease (IBD). In this study we have used a genus specific bacterial 16S PCR to investigate the prevalence and diversity of Pseudomonas species derived from the ileum of children with Crohn's disease (CD), and from control children with non-inflammatory bowel disease (non-IBD) undergoing their initial endoscopic examination. Fifty eight percent of CD patients (18/32) were positive using the Pseudomonas PCR, while significantly fewer children in the non-IBD group, 33% (12/36), were PCR positive for Pseudomonas (p<0.05, Fischer's exact test). Pseudomonas specific 16S PCR products from 13 CD and 12 non-IBD children were cloned and sequenced. Five hundred and eighty one sequences were generated and used for the comparative analysis of Pseudomonas diversity between CD and non-IBD patients. Pseudomonas species were less diverse in CD patients compared with non-IBD patients. In particular P.aeruginosa was only identified in non-IBD patients