Blood Cytokines as Biomarkers of In Vivo Toxicity in Preclinical Safety Assessment: Considerations for Their Use

In the drive to develop drugs with well-characterized and clinically monitorable safety profiles, there is incentive to expand the repertoire of safety biomarkers for toxicities without routine markers or premonitory detection. Biomarkers in blood are pursued because of specimen accessibility, opportunity for serial monitoring, quantitative measurement, and the availability of assay platforms. Cytokines, chemokines, and growth factors (here referred to collectively as cytokines) show robust modulation in proximal events of inflammation, immune response, and repair. These are key general processes in many toxicities; therefore, cytokines are commonly identified during biomarker discovery studies. In addition, multiplexed cytokine immunoassays are easily applied to biomarker discovery and routine toxicity studies to measure blood cytokines. However, cytokines pose several challenges as safety biomarkers because of a short serum half-life; low to undetectable baseline levels; lack of tissue-specific or toxicity-specific expression; complexities related to cytokine expression with multiorgan involvement; and species, strain, and interindividual differences. Additional challenges to their application are caused by analytical, methodological, and study design–related variables. A final consideration is the strength of the relationship between changes in cytokine levels and the development of phenotypic or functional manifestations of toxicity. These factors should inform the integrated judgment-based qualification of novel biomarkers in preclinical, and potentially clinical, risk assessment. The dearth of robust, predictive cytokine biomarkers for specific toxicities is an indication of the significant complexity of these challenges. This review will consider the current state of the science and recommendations for appropriate application of cytokines in preclinical safety assessment

Design, statistical analysis and sample size calculation of a phase IIb/III study of linagliptin versus voglibose and placebo

<p>Abstract</p> <p>Background</p> <p>Many patients with diabetes mellitus (DM) require a combination of antidiabetic drugs with complementary mechanisms of action to lower their hemoglobin A_1clevels to achieve therapeutic targets and reduce the risk of cardiovascular complications. Linagliptin is a novel member of the dipeptidyl peptidase-4 (DPP-4) inhibitor class of antidiabetic drugs. DPP-4 inhibitors increase incretin (glucagon-like peptide-1 and gastric inhibitory polypeptide) levels, inhibit glucagon release and, more importantly, increase insulin secretion and inhibit gastric emptying. Currently, phase III clinical studies with linagliptin are underway to evaluate its clinical efficacy and safety. Linagliptin is expected to be one of the most appropriate therapies for Japanese patients with DM, as deficient insulin secretion is a greater concern than insulin resistance in this population. The number of patients with DM in Japan is increasing and this trend is predicted to continue. Several antidiabetic drugs are currently marketed in Japan; however there is no information describing the effective dose of linagliptin for Japanese patients with DM.</p> <p>Methods</p> <p>This prospective, randomized, double-blind study will compare linagliptin with placebo over a 12-week period. The study has also been designed to evaluate the safety and efficacy of linagliptin by comparing it with another antidiabetic, voglibose, over a 26-week treatment period. Four treatment groups have been established for these comparisons. A phase IIb/III combined study design has been utilized for this purpose and the approach for calculating sample size is described.</p> <p>Discussion</p> <p>This is the first phase IIb/III study to examine the long-term safety and efficacy of linagliptin in diabetes patients in the Japanese population.</p> <p>Trial registration</p> <p>Clinicaltrials.gov (NCT00654381).</p

Potential of NIR spectroscopy to predict amygdalin content established by HPLC in intact almonds and classification based on almond bitterness

[EN] In this study, 360 intact almonds, half sweet and half bitter, were assessed by near-infrared (NIR) spectroscopy to predict amygdalin content (established by high performance liquid chromatography (HPLC)) and by applying partial least squares (PLS) to the spectral data. After optimising amygdalin extraction and chromatographic conditions, the amygdalin contents found by HPLC were not detected or below to 350 mg kg-1 for sweet almonds, and between 14,700 and 50,400mg kg 1 for bitter almonds. The intact almond spectra resulted in good predictions of amygdalin content with R2p of 0.939 and RMSEP of 0.373. Almonds were correctly classified into sweet and bitter by linear discriminant analysis (LDA), quadratic discriminant analysis (QDA) and PLS-DA, with sensitivity and specificity values higher than 0.94 for evaluation set samples. Based on these results, it can be concluded that NIR spectroscopy is a good non-destructive alternative to be used as an automatic in-line classification system by food industry.Victoria Cortes Lopez thanks the Spanish Ministry of Education, Culture and Sports for the FPU grant (FPU13/04202). The authors wish to thank the cooperative Agricoop for kindly donating the almonds.Cortes-Lopez, V.; Talens Oliag, P.; Barat Baviera, JM.; Lerma-García, MJ. (2018). Potential of NIR spectroscopy to predict amygdalin content established by HPLC in intact almonds and classification based on almond bitterness. Food Control. 91:68-75. https://doi.org/10.1016/j.foodcont.2018.03.040S68759

Chemical stability study of vitamins thiamine, riboflavin, pyridoxine and ascorbic acid in parenteral nutrition for neonatal use

<p>Abstract</p> <p>Background</p> <p>The objective of this work was to study the vitamins B₁, B₂, B₆and C stability in a pediatric formulation containing high amounts of calcium in the presence of organic phosphate, amino acids, glucose, sodium chloride, magnesium sulfate, pediatric vitamins and trace elements under different conditions using developed and validated analytical methods.</p> <p>Methods</p> <p>The study was carried out during 72 h with formulations packaged in recommended storage temperature (4°C) and 25°C, with and without photoprotection.</p> <p>Results</p> <p>The results showed that the methodologies used for assessing the chemical stability of vitamins B₁, B₂, B₆and C in the formulation were selective, linear, precise and accurate. The vitamins could be considered stable in the formulation during the three days of study if stored at 4°C. When stored at 25°C vitamin C presented instability after 48 h.</p> <p>Conclusion</p> <p>The pediatric formulation containing high amount of calcium in the presence of organic phosphate, amino acids, glucose, sodium chloride, magnesium sulphate, pediatric vitamins and trace elements packaged in bag-type trilaminate presented a shelf life of the 72 h, when maintained under refrigeration, between 2°C and 8°C. This shelf life was measured considering the vitamins studied. Further studies are needed including all the vitamins present in this formulation.</p

Status of national research bioethics committees in the WHO African region

BACKGROUND: The Regional Committee for Africa of the World Health Organization (WHO) in 2001 expressed concern that some health-related studies undertaken in the Region were not subjected to any form of ethics review. In 2003, the study reported in this paper was conducted to determine which Member country did not have a national research ethics committee (REC) with a view to guiding the WHO Regional Office in developing practical strategies for supporting those countries. METHODS: This is a descriptive study. The questionnaire was prepared and sent by diplomatic pouch to all the 46 Member States in the WHO African Region, through the WHO country representatives, for facilitation and follow up. The data were entered in Excel spreadsheet and subsequently exported to STATA for analysis. A Chi-Squared test (χ(2)) for independence was undertaken to test the relationship between presence/absence of Research Ethics Committee (REC) and selected individual socioeconomic and health variables. RESULTS: The main findings were as follows: the response rate was 61% (28/46); 64% (18/28) confirmed the existence of RECs; 36% (10/28) of the respondent countries did not have a REC (although 80% of them reported that they had in place an ad hoc ethical review mechanism); 85% (22/26) of the countries that responded to this question indicated that ethical approval of research proposals was, in principle, required; and although 59% of the countries that had a REC expected it to meet every month, only 44% of them reported that the REC actually met on a monthly basis. In the Chi-Squared test, only the average population in the group of countries with a REC was statistically different (at 5% level of significance) from that of the group of countries without a REC. CONCLUSION: In the current era of globalized biomedical research, good ethics stewardship demands that every country, irrespective of its level of economic development, should have in place a functional research ethics review system in order to protect the dignity, integrity and safety of its citizens who participate in research

Extractive Spectrophotometric Method for the Determination of Tropicamide

Two simple, rapid, and extractive spectrophotometric methods were developed for the determination of tropicamide (TPC). These methods are based on the formation of ionpair complexes between the basic nitrogen of the drug with bromocresol purple (BCP) and methyl orange (MO) in acidic buffer solution. The formed complexes were extracted with chloroform and measured at 408 and 427 nm using BCP and MO, respectively. Beer's law was obeyed in the range 1.0–16 μg ml–1 with correlation coefficient (n=6) ≥0.9991. The molar absorpitivity, Sandell sensitivity, detection, and quantification limits were also calculated. The composition of the ion pairs was found 1:1 by Job's method. The proposed methods have been applied successfully for the analysis of TPC in pure and in its eye drops

Pharmacovigilance of antimalarial treatment in Africa: is it possible?

Pharmacovigilance, defined as "the science and activities relating to the detection, assessment, understanding and prevention of adverse effects or any other possible drug related problem", is increasingly being recognized in Africa. Many African countries have simultaneously adopted artemisinin derivative based combination therapy (ACT) as first-line treatment for uncomplicated malaria, offering an opportunity to assess the safety of these drugs when used widely. While ACTs appear to be safe and well-tolerated, there is little experience with these medicines in Africa, outside clinical trials. Pharmacovigilance for ACTs and other combination treatments in Africa is essential. Malaria transmission intensity is high and antimalarial medicines are used frequently. Presumptive treatment of fever with antimalarials is common, often in the absence of a confirmed diagnosis, using drugs obtained without a prescription. Informal use of antimalarial drugs may increase the risk of incorrect dosing, inappropriate treatment, and drug interactions, which may impact negatively on drug safety. Furthermore, the administration of antimalarial treatments in patients with a concomitant illness, including HIV/AIDs, tuberculosis and malnutrition, is a concern. African countries are being encouraged to establish pharmacovigilance systems as ACTs are rolled out. However, pharmacovigilance is difficult, even in countries with a well-developed health care system. The rationale for pharmacovigilance of antimalarial drugs is discussed here, outlining the practical challenges and proposing approaches that could be adopted in Africa