Impact of blood cell counts and volumes on glucose concentration in uncentrifuged serum and lithium-heparin blood tubes.

BACKGROUND: Although it is known that glucose concentration exhibits a time-dependent decay in uncentrifuged serum and lithium-heparin blood tubes, no evidence exists on how this variation may depend on blood cell counts (CBC) and volumes. METHODS: Venous blood was drawn from 30 non fasting healthy volunteers into three serum and three lithium-heparin tubes. One serum and lithium-heparin tubes were centrifuged within 15 min after collection and glucose was measured with a hexokinase assay. The second and third serum and lithium-heparin tubes were maintained at room temperature for 1 and 2 h after the first tubes were centrifuged. These other tubes were then centrifuged and glucose was measured. CBC was performed in the first lithium-heparin tube, before centrifugation. RESULTS: The mean decrease of glucose was higher in lithium-heparin plasma than in serum (0.33 vs. 0.24 mmol/L/h; p<0.001). Glucose concentration decreased by 7% and 5% per hour in lithium-heparin plasma and serum, respectively. In univariate analysis, the absolute decrease of glucose concentration was associated with sex (higher in men than in women), red blood cell (RBC) count, hematocrit, white blood cell (WBC) count, neutrophils and monocytes in both lithium-heparin plasma and serum. In multivariate analysis, the decrease of glucose concentration remained independently associated with RBC, WBC, neutrophils and monocytes in both sample matrices. No significant association was found with platelet number and erythrocyte or platelet volume. CONCLUSIONS: Glucose concentration decrease in uncentrifuged lithium-heparin and serum tubes depends on the baseline number of RBC, WBC, neutrophils and monocytes within the tubes.

Three years of paediatric regulation in the European Union.

PURPOSE: To investigate whether the Paediatric Regulation has already succeeded in addressing the needs of the paediatric population both quantitatively with respect to paediatric development plans and trials, and qualitatively with respect to the content of the plans. The Paediatric Regulation No 1901/2006 entered into force in Europe on 26 January 2007, with the aim to improve the development of medicinal products, to address the lack of age-appropriate formulations and to provide information on efficacy, safety and dosing for the paediatric population. The Regulation requires applications for marketing authorisations to be accompanied by either a product-specific waiver or a paediatric investigation plan, to be agreed by the Paediatric Committee (PDCO) of the European Medicines Agency (EMA). METHODS: A retrospective analysis of the applications for Paediatric Investigation Plans (PIPs) and Waivers submitted to the EMA, from 2007 until end of 2009, was performed. The content of scientific opinions adopted by the Paediatric Committee was compared to the proposals submitted by industry, and the paediatric clinical trials registered in the European Union Drug Regulating Authorities Clinical Trials (EudraCT) database were examined. RESULTS: An increasing paediatric medicine development can be expected following the adoption of this legal framework. The highest number of PIPs was in the fields of endocrinology (13.4%), oncology (11%) and infectious (10.8%) and cardiovascular diseases (7.1%), but most therapeutic areas now benefit from paediatric development. A large number of PIPs include measures for the development of age-appropriate formulations (23%), and most include studies on dosing, efficacy and safety to cover the respective paediatric subsets, including the mostly neglected neonates (26%). In many proposals (38%), however, the PDCO had to request major modifications to the proposed PIPs to ensure that the results will meet the needs, in particular by requesting better methodology. The proportion of paediatric trials as a percentage of all clinical trials has moderately increased (from 8.2 to 9.4% of all trials), and this may reflect the fact that paediatric trials are generally deferred (82%) until after adult development. CONCLUSIONS: This is the first analysis of the general impact of the Paediatric Regulation on the development of medicinal products in Europe. Three years after the implementation of the Paediatric Regulation, we were able to identify that the PIPs address the main gaps in knowledge on paediatric medicines. The key objective of the Paediatric Regulation, namely, the availability of medicines with age-appropriate information, is going to be achieved. It is clear also that modifications of the initial proposals as requested by the PDCO are necessary to ensure the quality of paediatric developments. The impact on the number of clinical trials performed remains modest at this point in time, and it will be of high interest to monitor this performance indicator, which will also inform us whether paediatric medicine research takes place in Europe or elsewhere.

No association between lithium full responders and the DRD1, DRD2, DRD3, DAT1, 5-HTTLPR and HTR2A genes in a Sardinian sample.

Polymorphisms within the DRD1, DRD2, DRD3, DAT1, 5-HTTLPR and HTR2A genes are being studied for association with lithium prophylaxis in a sample of 155 Sardinian unrelated probands affected by bipolar disorder (BP). No significant association was shown between the polymorphisms of the genes studied and response to lithium treatment.

Association study in a Sardinian sample between bipolar disorder and the nuclear receptor REV-ERBalpha gene, a critical component of the circadian clock system.

OBJECTIVE: The aim of our study was to investigate the association between REV-ERBalpha gene (NR1D1) single nucleotide polymorphisms (SNPs) and bipolar disorder (BP) in a case-control sample of Sardinian ancestry and evaluate its effect on age at onset (AAO) of BP. METHODS: We genotyped SNPs rs12941497 (SNP1) and rs939347 (SNP2), located, respectively, in the first intron and in the 5'UTR region of the gene, in a sample comprised of 300 bipolar patients and 300 healthy controls of Sardinian ancestry. We also studied AAO by means of admixture analysis, obtaining a cutoff point of age 22 and then carrying out association analysis between the two AAO groups. RESULTS: In the case-control comparison, single marker analysis showed no association for any of the SNPs tested. Haplotype analysis showed a nominally significant association for two haplotypes of SNPs 1-2. Comparing the early- and later-onset groups, nominal association was found for SNP1. Haplotype analysis showed that one haplotype was nominally associated with the later-onset group. CONCLUSIONS: Our results, indicating a nominal association of the REV-ERBalpha gene with BP, suggest a possible role of REV-ERBalpha in the pathogenesis of BP. Further investigation of larger independent samples and different populations is warranted.

[Evaluation of lithium treatment response in Sardinian bipolar patients]. / Valutazione della risposta ai sali di litio in pazienti sardi affetti da disturbo bipolare.

AIM: Bipolar disorder (BP) is a mood disorder with a prevalence of 1-2% in the general population. Lithium is the most widely used and best characterized long-term treatment for BP. The aim of this study is the evaluation of the effectiveness of lithium treatment in a naturalistic setting. Moreover we investigated if a number of clinical markers were positively or negatively associated with treatment response. METHODS: We evaluated 199 outpatients affected by BP (according to DSM-IV criteria), who had continuously received lithium for at least one year. Life course of illness in each patient was graphically depicted with the NIMH Life Chart method which allowed us to apply the Retrospective Evaluation of Prophylactic Treatment Response Scale in order to assess the treatment outcome. This scale rates the degree of improvement in the course of treatment weighted by the likelihood of response being attributable to the treatment, rather than other factors. RESULTS: Full Responders to lithium were 29% of the sample. Bipolar II (BPII) patients were significantly overrepresented in the Full Responders group (p = 0.035). In addition, psychotic symptoms were significantly associated to a poorer treatment outcome (p = 0.0197). CONCLUSIONS: This study supports the effectiveness of lithium treatment in a naturalistic setting, suggesting that BPII patients could also benefit from lithium treatment. Finally, it suggests that the use of another mood stabilizer or of a combination treatment could represent a valuable therapeutic choice in the management of bipolar patients with psychotic symptoms.

The PDLIM5 gene and lithium prophylaxis: an association and gene expression analysis in Sardinian patients with bipolar disorder.

A number of studies support the notion that lithium interacts with the protein kinase C (PKC) pathway, an important mediator of several intracellular responses to neurotransmitter signaling. PDLIM5 (PDZ and LIM domain 5; LIM) is an adaptor protein that selectively binds the isozyme PKC(epsilon) to N-type Ca(2+) channels in neurons. We tested for an association between three single nucleotide polymorphisms (SNPs) at the PDLIM5 gene and lithium prophylaxis in a Sardinian sample comprised of 155 bipolar patients treated with lithium. In order to evaluate whether PDLIM5 expression interacts with lithium response, we carried out gene expression analysis in lymphoblastoid cells of 30 bipolar patients. No association was shown between PDLIM5 polymorphisms and lithium response. When PDLIM5 expression was evaluated, no significant differences were detected between Full Responders to lithium (total score>or=7) and other patients (total score

Age at onset in Sardinian bipolar I patients: evidence for three subgroups.

OBJECTIVE: We studied age at onset (AAO) in order to assess the presence of different subgroups in a homogeneous genetic population, such as the Sardinian population. METHODS: Admixture analysis was applied in order to identify a model of separate normal distribution of AAO characterized by different means, variances and population proportions to allow for evaluation of different subgroups in a sample of 181 unrelated patients of Sardinian origin with bipolar disorder (BP) type I. The Mann-Whitney test was used to compare the means of AAO between subjects with a history of suicide attempts and subjects with no such history. RESULTS: The best-fitting model had three components with means (SD) of 18.1 (2.3), 24.3 (5.3) and 41 (11.5) years, comprising 36%, 39% and 25% of the sample, respectively. We obtained two cut-off points at 21 and 33 years, enabling the sample to be divided into three subgroups. The Mann-Whitney test revealed a difference between the mean AAO of subjects with a positive history of suicide attempts and that of subjects with no such history (p = 0.041). CONCLUSIONS: We found three AAO sub-groups in our sample of BP I patients of Sardinian origin. Our findings add further support to the hypothesis whereby AAO acts as a clinical marker of biological heterogeneity in BP.