Influence of ABCB1 polymorphisms and haplotypes on tacrolimus nephrotoxicity and dosage requirements in children with liver transplant

AIMS
The aim of this study was to investigate the in?uence of genetic polymorphisms in ABCB1 on the incidence of nephrotoxicity and tacrolimus dosage-requirements in paediatric patients following liver transplantation.
METHODS
Fifty-one paediatric liver transplant recipients receiving tacrolimus were genotyped for ABCB1 C1236>T, G2677>T and C3435>T polymorphisms. Dose-adjusted tacrolimus trough concentrations and estimated glomerular ?ltration rates (EGFR) indicative of renal toxicity were determined and correlated with the corresponding genotypes.
RESULTS
The present study revealed a higher incidence of the ABCB1 variant-alleles examined among patients with renal dysfunction (30% reduction in EGFR) at 6 months post-transplantation (1236T allele: 63.3% vs 37.5% in controls,P = 0.019; 2677T allele: 63.3% vs. 35.9%, p = 0.012; 3435T allele: 60% vs. 39.1%,P = 0.057). Carriers of the G2677->T variant allele also had a signi?cant reduction (%) in EGFR at 12 months post-transplant (mean difference = 22.6%; P = 0.031). Haplotype analysis showed a signi?cant association between T-T-T haplotypes and an increased incidence of nephrotoxicity at 6 months post-transplantation (haplotype-frequency = 52.9% in nephrotoxic patients vs 29.4% in controls; P = 0.029). Furthermore, G2677->T and C3435->T polymorphisms and T-T-T haplotypes were signi?cantly correlated with higher tacrolimus dose-adjusted pre-dose concentrations at various time points examined long after drug initiation.
CONCLUSIONS
These ?ndings suggest that ABCB1 polymorphisms in the native intestine signi?cantly in?uence tacrolimus dosage-requirement in the stable phase after transplantation. In addition, ABCB1 polymorphisms in paediatric liver transplant recipients may predispose them to nephrotoxicity over the ?rst year posttransplantation. Genotyping future transplant recipients for ABCB1 polymorphisms, therefore, could have the potential to individualize better tacrolimus immunosuppressive therapy and enhance drug safety

Quality of life and inflammation in exacerbations of bronchiectasis.

Patients with bronchiectasis often have impaired quality of life (QoL), which deteriorates with exacerbations. The aim of this study was to investigate changes in QoL and how these were influenced by changes in airway physiology and inflammation in patients with bronchiectasis before and after resolution of an exacerbation. Sputum induction and a QoL questionnaire were undertaken on the first day, day 14, and 4 weeks after completion of intravenous antibiotics (day 42). Eighteen patients (12 female) were recruited, median (IQ range) age of 54 (47–60) years. There was a trend towards an improvement in lung function from visit 1 to visit 2, but this was not statistically significant. C-reactive protein (CRP) [mean (SEM)] reduced between visit 1 and visit 2 [55.4 (21.5) vs 9.4 (3.1) mg/L, P = 0.03] but did not increase significantly on visit 3 [44.4 (32.9) mg/L, P = 0.27]. The median (interquartile range) sputum cell count (×106 cells/g of sputum) decreased from visit 1 to visit 2 [21.6 (11.8–37.6)–13.3 (6.7–22.9) × 106 cells/g, respectively, P = 0.008] and increased from visit 2 to visit 3 [26.3 (14.1–33.6) × 106 cells/g, P = 0.03]. All soluble markers of inflammation significantly reduced from visit 1 to visit 2 but increased on visit 3 with the exception of TNF-a. Regarding QoL, three of the four domains (dyspnoea, emotional, mastery) significantly improved from visit 1 to visit 2 but did not change between visit 2 and visit 3. The improvements in QoL scores could not be explained by the improvements in lung function or inflammatory markers.

Langerhans cells are critical in the development of atopic dermatitis-like inflammation and symptoms in mice

Genetic or vitamin D3-induced overexpression of thymic stromal lymphopoietin (TSLP) by keratinocytes results in an atopic dermatitis (AD)-like inflammatory phenotype in mice echoing the discovery of high TSLP expression in epidermis from AD patients. Although skin dendritic cells (DC) are suspected to be involved in AD, direct evidence of a pathogenetic role for skin DC in TSLP-induced skin inflammation has not yet been demonstrated. In a mouse model of AD, i.e. mice treated with the low-calcemic vitamin D3 analogue, MC903, we show that epidermal Langerhans cells (LC)-depleted mice treated with MC903 do neither develop AD-like inflammation nor increased serum IgE as compared to vitamin D3 analogue-treated control mice. Accordingly, we show that, in mice treated with MC903 or in K14-TSLP transgenic mice, expression of maturation markers by LC is increased whereas maturation of dermal DC is not altered. Moreover, only LC are responsible for the polarization of naive CD4+ T cells to a Th2 phenotype, i.e. decrease in interferon-gamma and increase in interleukin (IL)-13 production by CD4+ T cells. This effect of LC on T-lymphocytes does not require OX40-L/CD134 and is mediated by a concomitant down-regulation of IL-12 and CD70. Although it was previously stated that TSLP up-regulates the production of thymus and activation-regulated chemokine (TARC)/chemokine (C-C motif) ligand 17 (CCL17) and macrophage-derived chemokine (MDC)/CCL22 by human LC in vitro, our work shows that production of these Th2- cell attracting chemokines is increased only in keratinocytes in response to TSLP overexpression. These results demonstrate that LC are required for the development of AD in mouse models of AD involving epidermal TSLP overexpression.

Runx2, p53, and pRB Status as Diagnostic Parameters for Deregulation of Osteoblast Growth and Differentiation in a New Pre-Chemotherapeutic Osteosarcoma Cell Line (OS1)

Osteosarcomas are the most prevalent primary bone tumors found in pediatric patients. To understand their molecular etiology, cell culture models are used to define disease mechanisms under controlled conditions. Many osteosarcoma cell lines (e.g., SAOS-2, U2OS, MG63) are derived from Caucasian patients. However, patients exhibit individual and ethnic differences in their responsiveness to irradiation and chemotherapy. This motivated the establishment of osteosarcoma cell lines (OS1, OS2, OS3) from three ethnically Chinese patients. OS1 cells, derived from a pre-chemotherapeutic tumor in the femur of a 6-year-old female, were examined for molecular markers characteristic for osteoblasts, stem cells, and cell cycle control by immunohistochemistry, reverse transcriptase-PCR, Western blotting and flow cytometry. OS I have aberrant G-banded karyotypes, possibly reflecting chromosomal abnormalities related to p53 deficiency. OS I had ossification profiles similar to human fetal osteoblasts rather than SAOS-2 which ossifies ab initio, (P

Effect of fruit and vegetable intake on oxidative stress and inflammation in COPD: a randomised controlled trial

Epidemiological evidence supports a positive relationship between fruit and vegetable (FV) intake, lung function and chronic obstructive pulmonary disease (COPD). Increasing FV intake may attenuate the oxidative stress and inflammation associated with COPD.

An exploratory randomised controlled trial to examine the effect of increased consumption of FV on oxidative stress and inflammation in moderate-to-severe COPD was conducted. 81 symptomatically stable patients with a habitually low FV intake (two or fewer portions of FV per day) were randomised to the intervention group (five or more portions of FV per day) or the control group (two or fewer portions of FV per day). Each participant received self-selected weekly home deliveries of FV for 12 weeks.

75 participants completed the intervention. There was a significant between-group change in self-reported FV intake and biomarkers of FV intake (zeaxanthin (p=0.034) and ß-cryptoxanthin (p=0.015)), indicating good compliance; post-intervention intakes in intervention and control groups were 6.1 and 1.9 portions of FV per day, respectively. There were no significant changes in biomarkers of airway inflammation (interleukin-8 and myeloperoxidase) and systemic inflammation (C-reactive protein) or airway and systemic oxidative stress (8-isoprostane).

This exploratory study demonstrated that patients with moderate-to-severe COPD were able to comply with an intervention to increase FV intake; however, this had no significant effect on airway or systemic oxidative stress and inflammation.

Prescribing Practices and Polypharmacy in Kitovu Hospital, Uganda.

This audit of prescribing practices explores recent trends at Kitovu Hospital, Uganda. The average number of drugs prescribed per patient was 2.89 ± 0.11, of which 1.79±0.09 were generics and 0.69±0.06 antibiotics. No injections were prescribed. Patient essential drug knowledge was 100% while the adequacy of labelling was 0%. The number of drugs prescribed correlated positively with patient age, was greater for female patients, similar for doctors and clinical officers but greater in medical (3.30±0.15, n=50) than surgical (2.48±0.13, n=50) outpatient clinics. The mean consultation time was 6.56 min and 10.25 min per patient in medical and surgical outpatient clinics respectively. The patient essential knowledge indicators were greatly improved but only modest reduction in polypharmacy was evident compared to the Ugandan Pharmaceutical Sector national survey of 2002. Antibiotic prescription was high and generic prescribing was found to be low. Policy changes are required to enhance rational drug use in the health sector in Uganda.

Apoptosis and chemotherapy in bladder cancer in bladder cancer

Purpose: To discuss the role of apoptosis, gene directed self-destruction of a cell, in the response of transitional cell carcinoma of the bladder cells to chemotherapy. Methods: A directed MEDLINE literature search of apoptosis, bladder cancer and chemotherapy was performed to extract the relevant information, which was reviewed. The characteristics of apoptotic cells were defined and the methods in common use to detect these traits were described. The role of the key mediators of the apoptotic process in bladder cancer is discussed in the context of chemosensitivity and stage of disease. The importance of induction of apoptosis post chemotherapy is highlighted. Results: On stimulus by appropriate external or internal signals, a cell may alter the expression of genes coding for proteins associated with the apoptotic process. The development of apoptosis depends on the balance between pro- and anti- apoptotic proteins. Key alterations in genes and proteins related to apoptosis within bladder cancer result in a shift away from an ability to undergo apoptosis towards a cell with increased survival properties that is chemoresistant. Conclusions: Much current research in bladder cancer is aimed at restoring chemosensitivity by shifting the balance in a cell towards a pro-apoptotic phenotype. Successful translation of this work into clinical practice may improve survival in patients in whom prognosis is currently poor.

Association of impulsivity with sleep duration and insomnia in an employee population

Clinical studies have linked impulsivity and insomnia in patients, but little is known about this association in non-clinical settings. This study examined whether impulsive temperament is associated with sleep duration and insomnia complaints in a large cohort of hospital employees (535 men and 4014 women). Linear regression models were related to prospective data from two surveys conducted in 1998 and 2000. Adjustments were made for age, marital status, education, shift work, smoking, alcohol consumption, body mass index, physical activity, minor psychiatric morbidity, social support, somatic disease, depression and other psychiatric disease in 1998. In men, higher impulsivity predicted shorter sleep duration and waking up several times per night independent of baseline characteristics. In women, higher impulsivity predicted having difficulty falling asleep and waking up feeling tired after the usual amount of sleep after adjustment for most of covariates. However, these associations turned out to be non-significant after adjustment for somatic and psychiatric disease. These results support the hypothesis that impulsive temperament could be a risk factor for insomnia in men. (c) 2007 Elsevier Ltd. All rights reserved.

Heat shock protein 90 inhibition is cytotoxic to primary AML cells expressing mutant FLT3 and results in altered downstream signalling

Activating mutations of the FMS-like tyrosine kinase 3 gene (FLT3) occur in approximately one-third of patients with acute myeloid leukaemia (AML) and predict for a poor outcome. Heat shock protein 90 (Hsp90) is a molecular chaperone that is frequently used by cancer cells to stabilise mutant oncoproteins. Mutant FLT3 is chaperoned by Hsp90 in primary AML blasts whereas unmutated FLT3 is not, making Hsp90 inhibitors potentially useful therapeutically. The present study showed that inhibition of Hsp90 by 17-allylamino-17-demethoxygeldanamycin (17-AAG) was cytotoxic to primary AML cells expressing mutant FLT3. Inhibition of Hsp90 results in altered downstream signalling effects in primary AML cells with disruption of Janus kinase-signal transducer and activator of transcription (JAK-STAT), mitogen-activated protein kinase and phosphatidylinositol 3/AKT signalling pathways. Co-treatment of blasts with 17-AAG and cytarabine resulted in a synergistic or additive effect in approximately 50% of AML cases tested. Our results confirm that Hsp90 is a valid molecular target in the therapy of AML. Inhibition of Hsp90 in parallel with conventional AML therapies may have particular benefit in those patients with the poor prognostic FLT3 mutant disease.

Visual function and dysfunction in early and late age-related maculopathy

Late age-related maculopathy (ARM) is responsible for the majority of blind registrations in the Western world among persons over 50 years of age. It has devastating effects on quality of life and independence and is becoming a major public health concern. Current treatment options are limited and most aim to slow progression rather than restore vision; therefore, early detection to identify those patients most suitable for these interventions is essential. In this work, we review the literature encompassing the investigation of visual function in ARM in order to highlight those visual function parameters which are affected very early in the disease process. We pay particular attention to measures of acuity, contrast sensitivity (CS), cone function, electrophysiology, visual adaptation, central visual field sensitivity and metamorphopsia. We also consider the impact of bilateral late ARM on visual function as well as the relationship between measures of vision function and self-reported visual functioning. Much interest has centred on the identification of functional changes which may predict progression to neovascular disease; therefore, we outline the longitudinal studies, which to date have reported dark-adaptation time, short-wavelength cone sensitivity, colour-match area effect, dark-adapted foveal sensitivity, foveal flicker sensitivity, slow recovery from glare and slower foveal electroretinogram implicit time as functional risk factors for the development of neovascular disease. Despite progress in this area, we emphasise the need for longitudinal studies designed in light of developments in disease classification and retinal imaging, which would ensure the correct classification of cases and controls, and provide increased understanding of the natural course and progression of the disease and further elucidate the structure-function relationships in this devastating disorder.

Allelic variation at the A218C tryptophan hydroxylase polymorphism influences agitation and aggression in Alzheimer's disease

The behavioural and psychological symptoms of dementia are common, distressing to carers, and directly linked to the requirement for institutional care. Symptoms of aggression and agitation are particularly difficult for carers to tolerate. The origin of these features is unclear although genetic and environmental modification of pre-frontal serotonergic circuitry which regulates the control of negative emotions is proposed. Following the suggestion that the A218C intronic polymorphism of the tryptophan hydroxylase gene influences aggression and anger in non-demented individuals, we tested the influence of A218C on symptoms of agitation/aggression in 396 Alzheimer's disease patients using the Neuropsychiatric Inventory. Overall, 50% of participants experienced agitation/aggression in the month prior to interview. It was observed that male patients with a history of agitation/aggression were more likely to possess C-containing genotypes (P = 0.044, OR = 1.65, CI = 0.98-2.76). We conclude that aggression in male subjects with Alzheimer's disease may be genetically linked to polymorphic variation at the tryptophan hydroxylase gene.

Steps to a better Belfast: physical activity assessment and promotion in primary care

BACKGROUND: Low physical activity (PA) levels which increase the risk of chronic disease are reported by two-thirds of the general UK population. Promotion of PA by primary healthcare professionals is advocated but more evidence is needed regarding effective ways of integrating this within everyday practice. This study aims to explore the feasibility of a randomised trial of a pedometer-based intervention, using step-count goals, recruiting patients from primary care. METHOD: Patients, aged 35-75, attending four practices in socioeconomically deprived areas, were invited to complete a General Practice PA Questionnaire during routine consultations. Health professionals invited 'inactive' individuals to a pedometer-based intervention and were randomly allocated to group 1 (prescribed a self-determined goal) or group 2 (prescribed a specific goal of 2500 steps/day above baseline). Both groups kept step-count diaries and received telephone follow-up at 1, 2, 6 and 11 weeks. Step counts were reassessed after 12 weeks. RESULTS: Of the 2154 patients attending, 192 questionnaires were completed (8.9%). Of these, 83 were classified as 'inactive'; 41(10 men; 31 women) completed baseline assessments, with the mean age of participants being 51 years. Mean baseline step counts were similar in group 1 (5685, SD 2945) and group 2 (6513, SD 3350). The mean increase in steps/day was greater in groups 1 than 2 ((2602, SD 1957) vs (748, SD 1997) p=0.005). CONCLUSIONS: A trial of a pedometer-based intervention using self-determined step counts appears feasible in primary care. Pedometers appear acceptable to women, particularly at a perimenopausal age, when it is important to engage in impact loading activities such as walking to maintain bone mineral density. An increase of 2500 steps/day is achievable for inactive patients, but the effectiveness of different approaches to realistic goal-setting warrants further study.

JAK2V617F homozygosity arises commonly and recurrently in PV and ET, but PV is characterized by expansion of a dominant homozygous subclone

Subclones homozygous for JAK2V617F are more common in polycythemia vera (PV) than essential thrombocythemia (ET), but their prevalence and significance remain unclear. The JAK2 mutation status of 6495 BFU-E, grown in low erythropoietin conditions, was determined in 77 patients with PV or ET. Homozygous-mutant colonies were common in patients with JAK2V617F-positive PV and were surprisingly prevalent in JAK2V617F-positive ET and JAK2 exon 12-mutated PV. Using microsatellite PCR to map loss-of-heterozygosity breakpoints within individual colonies, we demonstrate that recurrent acquisition of JAK2V617F homozygosity occurs frequently in both PV and ET. PV was distinguished from ET by expansion of a dominant homozygous subclone, the selective advantage of which is likely to reflect additional genetic or epigenetic lesions. Our results suggest a model in which development of a dominant JAK2V617F-homzygous subclone drives erythrocytosis in many PV patients, with alternative mechanisms operating in those with small or undetectable homozygous-mutant clones.

Plasma Lipoproteins and Preeclampsia in Women with Type 1 Diabetes: A Prospective Study

Context: In nondiabetic pregnancy, cross-sectional studies have shown associations between maternal dyslipidemia and preeclampsia (PE). In type 1 diabetes mellitus (T1DM), the prevalence of PE is increased 4-fold, but prospective associations with plasma lipoproteins are unknown.

Objectives: The aim of this study was to define lipoprotein-related markers and potential mechanisms for PE in T1DM.

Design and Settings: We conducted a multicenter prospective study in T1DM pregnancy.

Patients: We studied 118 T1DM women (26 developed PE, 92 remained normotensive). Subjects were studied at three visits before PE onset [12.2 1.9, 21.6 1.5, and 31.5 1.7 wk gestation (means SD)] and at term (37.6 2.0 wk). Nondiabetic normotensive pregnant women (n 21) were included for reference.

Main Outcome Measures: Conventional lipid profiles, lipoprotein subclasses [defined by size (nuclear magnetic resonance) and by apolipoprotein content], serum apolipoproteins (ApoAI, ApoB, and ApoCIII), and lipolysis (ApoCIII ratio) were measured in T1DM women with and without subsequent PE.

Results: In women with vs. without subsequent PE, at the first and/or second study visits: lowdensity lipoprotein (LDL)-cholesterol, particle concentrations of total LDL and large (but not small) LDL, serum ApoB, and ApoB:ApoAI ratio were all increased (P 0.05); peripheral lipoprotein lipolysis was decreased (P0.01). These early differences remained significant in covariate analysis (glycated hemoglobin, actual prandial status, gravidity, body mass index, and diabetes duration) but were not present at the third study visit. High-density lipoprotein and very low-density lipoprotein subclasses did not differ between groups before PE onset.

Conclusions: Early in pregnancy, increased cholesterol-rich lipoproteins and an index suggesting decreased peripheral lipolysis were associated with subsequent PE in T1DM women. Background maternal lipoprotein characteristics, perhaps masked by effects of late pregnancy, may influence PE risk.