Use of HPLC/UPLC-spectrophotometry for detection of formazan in in vitro Reconstructed human Tissue (RhT)-based test methods employing the MTT-reduction assay to expand their applicability to strongly coloured test chemicals.

A number of in vitro test methods using Reconstructed human Tissues (RhT) are regulatory accepted for evaluation of skin corrosion/irritation. In such methods, test chemical corrosion/irritation potential is determined by measuring tissue viability using the photometric MTT-reduction assay. A known limitation of this assay is possible interference of strongly coloured test chemicals with measurement of formazan by absorbance (OD). To address this, Cosmetics Europe evaluated use of HPLC/UPLC-spectrophotometry as an alternative formazan measurement system. Using the approach recommended by the FDA guidance for validation of bio-analytical methods, three independent laboratories established and qualified their HPLC/UPLC-spectrophotometry systems to reproducibly measure formazan from tissue extracts. Up to 26 chemicals were then tested in RhT test systems for eye/skin irritation and skin corrosion. Results support that: (1) HPLC/UPLC-spectrophotometry formazan measurement is highly reproducible; (2) formazan measurement by HPLC/UPLC-spectrophotometry and OD gave almost identical tissue viabilities for test chemicals not exhibiting colour interference nor direct MTT reduction; (3) independent of the test system used, HPLC/UPLC-spectrophotometry can measure formazan for strongly coloured test chemicals when this is not possible by absorbance only. It is therefore recommended that HPLC/UPLC-spectrophotometry to measure formazan be included in the procedures of in vitro RhT-based test methods, irrespective of the test system used and the toxicity endpoint evaluated to extend the applicability of these test methods to strongly coloured chemicals.

Methods to evaluate and improve the injection site tolerability of intravenous formulations prior to first-in-human testing.

INTRODUCTION: Evaluation of infusion site tolerability is required for the development of intravenous formulations of New Molecular Entities and is of particular importance for investigational drugs that have the potential to precipitate on contact with the blood stream. Based on a comprehensive set of in vitro and in vivo studies conducted with JNJ-X, a development stage small molecule investigational drug, with a pH-dependent solubility that showed potential to cause infusion site irritation at high concentrations, we have developed a systematic approach for evaluating and selecting suitable intravenous formulations for compounds that show potential to precipitate at the infusion site. METHODS: Aqueous formulations containing a range of concentrations of JNJ-X with different excipients, and buffering agents at different pHs (3.9-7.4) were evaluated in an in vitro solubility assay, a modified hen's egg test-chorioallantoic membrane assay (HET-CAM(VT)) and in vivo in rabbit, rat, and dog intravenous infusion toxicity studies. RESULTS: The data obtained with JNJ-X in the different in vitro and in vivo studies were compared and used to support the development of an in silico model and to create a systematic approach to screen and identify candidate intravenous formulations with improved tolerability. DISCUSSION/CONCLUSION: This approach provides a framework that can be used to assess the risk for infusion site irritation and identify better tolerated formulations with a reduced need for in vivo testing.

Cosmetics Europe multi-laboratory pre-validation of the SkinEthic™ reconstituted human corneal epithelium test method for the prediction of eye irritation.

Cosmetics Europe, The Personal Care Association, known as Colipa before 2012, conducted a program of technology transfer and assessment of Within/Between Laboratory (WLV/BLV) reproducibility of the SkinEthic™ Reconstituted Human Corneal Epithelium (HCE) as one of two human reconstructed tissue eye irritation test methods. The SkinEthic™ HCE test method involves two exposure time treatment procedures - one for short time exposure (10 min - SE) and the other for long time exposure (60 min - LE) of tissues to test substance. This paper describes pre-validation studies of the SkinEthic™ HCE test method (SE and LE protocols) as well as the Eye Peptide Reactivity Assay (EPRA). In the SE WLV study, 30 substances were evaluated. A consistent outcome with respect to viability measurement across all runs was observed with all substances showing an SD of less than 18%. In the LE WLV study, 44 out of 45 substances were consistently classified. These data demonstrated a high level of reproducibility within laboratory for both the SE and LE treatment procedures. For the LE BLV, 19 out of 20 substances were consistently classified between the three laboratories, again demonstrating a high level of reproducibility between laboratories. The results for EPRA WLV and BLV studies demonstrated that all substances analysed were categorised similarly and that the method is reproducible. The SkinEthic™ HCE test method entered into the experimental phase of a formal ECVAM validation program in 2010.

The sNIHSS-4 predicts outcome in right and left anterior circulation strokes.

BACKGROUND AND PURPOSE: Stroke severity measured by the National Institutes of Health Stroke Scale (NIHSS) is a strong predictor of functional outcome. A short version, the sNIHSS-5, scoring only strength in right and left leg, gaze, visual fields and language, was developed for use in the prehospital setting. Because scoring both legs in anterior circulation strokes is not contributive, we assessed the value of a 4-item score (the sNIHSS-4), omitting the item 'strength in the unaffected leg', in predicting stroke outcome. METHODS: The study population consisted of anterior circulation ischemic stroke patients who participated in the LUB-INT-9 trial. We included all patients in whom the following data were available: NIHSS within 6h after stroke onset and daily between days 2 and 5, and the 12-week modified Rankin Scale (mRS) score. Poor outcome was defined as a mRS score>3. RESULTS: There was an excellent correlation between the NIHSS and sNIHSS-4 at all time points for both left and right-sided strokes. Scores at day 2 were a good predictor of poor outcome. Cutoff scores for NIHSS and sNIHSS-4 at day 2 were 15 and 5 in left hemispheric strokes, and 12 and 4 in right hemispheric strokes. CONCLUSION: The sNIHSS-4 is as good as the NIHSS at predicting stroke outcome in both right and left anterior circulation strokes.

Cosmetics Europe multi-laboratory pre-validation of the EpiOcular™ reconstituted human tissue test method for the prediction of eye irritation.

Cosmetics Europe, The Personal Care Association (known as Colipa before 2012), conducted a program of technology transfer and within/between laboratory reproducibility of MatTek Corporation's EpiOcular™ Eye Irritation Test (EIT) as one of the two human reconstructed tissue test methods. This EIT EpiOcular™ used a single exposure period for each chemical and a prediction model based on a cut-off in relative survival [ ≤60%=irritant (I) (GHS categories 2 and 1); >60%=no classification (NC)]. Test substance single exposure time was 30 min with a 2-h post-exposure incubation for liquids and 90 min with an 18-h post-exposure incubation for solids. Tissue viability was determined by tetrazolium dye (MTT) reduction. Combinations of 20 coded chemicals were tested in 7 laboratories. Standardized laboratory documentation was used by all laboratories. Twenty liquids (11 NC/9 I) plus 5 solids (3 NC/2 I) were selected so that both exposure regimens could be assessed. Concurrent positive (methyl acetate) and negative (water) controls were tested in each trial. In all, 298 independent trials were performed and demonstrated 99.7% agreement in prediction (NC/I) across the laboratories. Coefficients of variation for the% survival for tissues from each treatment group across laboratories were generally low. This protocol has entered in 2010 the experimental phase of a formal ECVAM validation program.

Spinal cord stimulation modulates cerebral function: an fMRI study.

INTRODUCTION: Although spinal cord stimulation (SCS) is widely used for chronic neuropathic pain after failed spinal surgery, little is known about the underlying physiological mechanisms. This study aims to investigate the neural substrate underlying short-term (30 s) SCS by means of functional magnetic resonance imaging in 20 patients with failed back surgery syndrome (FBSS). METHODS: Twenty patients with FBSS, treated with externalized SCS, participated in a blocked functional magnetic resonance imaging design with stimulation and rest phases of 30 s each, repeated eight times in a row. During scanning, patients rated pain intensity over time using an 11-point numerical rating scale with verbal anchors (0 = no pain at all to 10 = worst pain imaginable) by pushing buttons (left hand, lesser pain; right hand, more pain). This scale was back projected to the patients on a flat screen allowing them to manually direct the pain indicator. To increase the signal-to-noise ratio, the 8-min block measurements were repeated three times. RESULTS: Marked deactivation of the bilateral medial thalamus and its connections to the rostral and caudal cingulate cortex and the insula was found; the study also showed immediate pain relief obtained by short-term SCS correlated negatively with activity in the inferior olivary nucleus, the cerebellum, and the rostral anterior cingulate cortex. CONCLUSIONS: Results indicate the key role of the medial thalamus as a mediator and the involvement of a corticocerebellar network implicating the modulation and regulation of averse and negative affect related to pain. The observation of a deactivation of the ipsilateral antero-medial thalamus might be used as a region of interest for further response SCS studies.

Pre-stroke use of beta-blockers does not affect ischaemic stroke severity and outcome.

BACKGROUND AND PURPOSE: It is unclear whether pre-stroke beta-blockers use may influence stroke outcome. This study evaluates the independent effect of pre-stroke use of beta-blockers on ischaemic stroke severity and 3 months functional outcome. METHODS: Pre-stroke use of beta-blockers was investigated in 1375 ischaemic stroke patients who had been included in two placebo-controlled trials with lubeluzole. Stroke severity was assessed by either the National Institute of Health Stroke Scale (NIHSS) or the European Stroke Scale (ESS). A modified Rankin scale (mRS) score of >3 at 3 months was used as measure for the poor functional outcome. RESULTS: Two hundred and sixty four patients were on beta-blockers prior to stroke onset, and 105 patients continued treatment after their stroke. Pretreatment with beta-blockers did not influence baseline stroke severity. There was no difference in stroke severity between nonusers and those on either a selective beta(1)-blocker or a non-selective beta-blocker. The likelihood of a poor outcome at 3 months was not influenced by pre-stroke beta-blocker use or beta-blocker use before and continued after stroke onset. CONCLUSIONS: Pre-stroke use of beta-blockers does not appear to influence stroke severity and functional outcome at 3 months.

Application of human CFU-Mk assay to predict potential thrombocytotoxicity of drugs.

Megakaryocytopoiesis gives rise to platelets by proliferation and differentiation of lineage-specific progenitors, identified in vitro as Colony Forming Unit-Megakaryocytes (CFU-Mk). The aim of this study was to refine and optimize the in vitro Standard Operating Procedure (SOP) of the CFU-Mk assay for detecting drug-induced thrombocytopenia and to prevalidate a model for predicting the acute exposure levels that cause maximum tolerated decreases in the platelets count, based on the correlation with the maximal plasma concentrations (C max) in vivo. The assay was linear under the SOP conditions, and the in vitro endpoints (percentage of colonies growing) were reproducible within and across laboratories. The protocol performance phase was carried out testing 10 drugs (selected on the base of their recognised or potential in vivo haematotoxicity, according to the literature). Results showed that a relationship can be established between the maximal concentration in plasma (C max) and the in vitro concentrations that inhibited the 10-50-90 percent of colonies growth (ICs). When C max is lower than IC10, it is possible to predict that the chemicals have no direct toxicity effect on CFU-Mk and could not induce thrombocytopenia due to bone marrow damage. When the C max is higher than IC90 and/or IC50, thrombocytopenia can occur due to direct toxicity of chemicals on CFU-Mk progenitors.

Characterisation of pleural inflammation occurring after primary spontaneous pneumothorax.

The aim of this study was to examine the inflammatory reaction occurring in the pleural space of patients suffering from primary spontaneous pneumothorax (PSP) using pleural lavage, which was performed in patients with PSP and in healthy control subjects (essential hyperhidrosis patients undergoing thoracoscopy for sympathicolysis treatment). Cellular and solute composition of lavage fluid, peripheral blood and parietal pleural biopsies were analysed. PSP lavage fluid showed an increase in all differentiated leucocytes, but most strikingly eosinophils and neutrophils. In the blood of patients with PSP, the total number of leucocytes and the absolute number of eosinophils, neutrophils and monocytes were also significantly increased. The time in which air was present in the pleural space was positively correlated with the increase of eosinophils in lavage fluid, parietal pleura and blood. Eosinophilic cationic protein was elevated after PSP and strongly correlated with the absolute number of lavage eosinophils. Chemo and cytokine analysis in lavage fluid showed differences in concentrations of interleukin (IL)-5, IL-6, IL-8, IL-12p40, tumour necrosis factor-alpha and RANTES, but not of eotaxin. Surprisingly, high levels of lipopolysaccharide binding protein were also measured. Primary spontaneous pnumothorax is associated with a substantial pleural inflammatory reaction. The authors hypothesise that mechanical stretch factors, lipopolysaccharide binding protein/lipopolysaccharide complexes or other environmental components trigger pleural inflammation after primary spontaneous pnumothorax.

Modulation of phenotype, cytokine production and stimulatory function of CD34+-derived DC by NiCl(2) and SDS.

One of the most promising alternatives to identify the sensitizing potency of new products is the in vitro culture of human dendritic cells (DC). In vivo, dendritic cells present in the skin are highly specialized antigen-presenting cells (APC) of the immune system, which play a crucial role in the induction of allergic reactions. The DC produce specific cytokines and upregulate specific co-stimulatory molecules in addition to the antigen-MHC complex in order to promote an optimal T-cell activation. The aim of our study is to assess the phenotype, cytokine production and autologous T-cell stimulatory capacity of the in vitro CD34+-derived dendritic cells after 24 hours of incubation with the metal allergen NiCl(2) (100-300 microM) and the irritant sodium dodecyl sulfate (SDS; 0.01%), in order to find a sensitive endpoint to discriminate between sensitizers and irritants. After exposure to Ni, a significant increase in the number of CD83+ and CD86+ cells was noticed. The intensity of CD86 as well as the intensity of the HLA-DR molecule on the DC also showed a significant increase. The expression of the co-stimulatory molecule CD80 was not changed after exposure. SDS was not able to increase the expression of any of the analysed markers. The production of IL-6 increased significantly after exposure of dendritic cells to Ni, but not after SDS exposure. Results on tumor necrosis factor-alpha (TNF-alpha) production are somewhat equivocal. Although not statistically significant, TNF-alpha was upregulated in one out of three experiments after 48 hours of exposure to the Ni allergen, but increases were also noticed after exposure to SDS (two out of three experiments). Both exposure to Ni and SDS caused an upregulation (not significant) in the IL-12 production by DC, but the production was higher in Ni-exposed DC compared to SDS-exposed cells. In none of the exposed DC cultures was it possible to detect IL-1 beta. The antigen-presenting capacity of the DC in autologous MLR could not be demonstrated. Nevertheless, T-cell proliferation after DC stimulation was noticed in allogenic MLR.