MALDI Mass Spectrometry Imaging of 1-Methyl-4-phenylpyridinium (MPP+) in Mouse Brain

Parkinson’s disease (PD) is the second most common neurodegenerative disorder affecting ~1 % of the population older than 60 years. The administration of the proneurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) in mice is one of the most widely used approach to elucidate the mechanisms of cell death involved in PD. Its toxicity is attributed to its active metabolite 1-methyl-4-phenylpyridinium (MPP⁺). However, the magnitude of the PD-like neurodegeneration induced by MPTP depends on many variables, including the route of administration. Different groups, including us, demonstrated that intranasal (i.n.) administration of MPTP constitutes a new route of toxin delivery to the brain that mimics environmental exposure to neurotoxins. In particular, our previous data showed that mice submitted to acute i.n. MPTP administration displayed a significant decrease of striatal dopamine (DA) and a loss of dopaminergic (DA) neurons in the substantia nigra pars compacta. However, little is known about the timing and the anatomical distribution of MPP⁺ after i.n. MPTP administration in mice. In the present study, C57BL/6J mice received one dose of i.n. MPTP (1 mg/nostril) and were sacrificed at two different times after the administration. Using matrix-assisted laser desorption–ionization mass spectrometry imaging, a new technique for the detection of endogenous unlabeled molecules in tissue sections, we showed for the first time the MPP⁺ anatomical distribution in different brain regions. We demonstrated that the toxin first reached almost all the brain areas; however, in a second time MPP⁺ remained highly concentrated in the olfactory bulb, the basal ganglia, the ventral mesencephalon, and the locus coeruleus, regions differently affected in PD.     

Study on the effects of some factors that affect sea surface emissivity retrievals

The first aim of this article is to study the impact of some factors (effective wavelength, temperature, and aerial average emission angle) on sea surface emissivity (SSE) retrievals. It is well known that SSE is weakly influenced by these factors when we consider that each one of them acts independently from the others. However, taking them together, these factors are highly significant. The calculation of SSE including these factors has clearly brought out a high level of concordance between a theoretical model and in situ measurements for a wavelength of 11.0 µm especially at observation angles of 55° and 65° for wind speeds of 5 and 10 m s^?1. Wavelengths 8.7 and 12.0 µm also show, in most cases, a near to 0.000 or a negligible negative bias for an observation angle up to 55°. At wavelength 12 µm, the viewing angle of 65° seems to be questionable due to some inconsistencies and element of physics not well determined in practical terms.     

Combining multicriteria decision analysis, ethics and health technology assessment: applying the EVIDEM decisionmaking framework to growth hormone for Turner syndrome patients

Objectives

To test and further develop a healthcare policy and clinical decision support framework using growth hormone (GH) for Turner syndrome (TS) as a complex case study.

Methods

The EVIDEM framework was further developed to complement the multicriteria decision analysis (MCDA) Value Matrix, that includes 15 quantifiable components of decision clustered in four domains (quality of evidence, disease, intervention and economics), with a qualitative tool including six ethical and health system-related components of decision. An extensive review of the literature was performed to develop a health technology assessment report (HTA) tailored to each component of decision, and content was validated by experts. A panel of representative stakeholders then estimated the MCDA value of GH for TS in Canada by assigning weights and scores to each MCDA component of decision and then considered the impact of non-quantifiable components of decision.

Results

Applying the framework revealed significant data gaps and the importance of aligning research questions with data needs to truly inform decision. Panelists estimated the value of GH for TS at 41% of maximum value on the MCDA scale, with good agreement at the individual level (retest value 40%; ICC: 0.687) and large variation across panelists. Main contributors to this panel specific value were "Improvement of efficacy", "Disease severity" and "Quality of evidence". Ethical considerations on utility, efficiency and fairness as well as potential misuse of GH had mixed effects on the perceived value of the treatment.

Conclusions

This framework is proposed as a pragmatic step beyond the current cost-effectiveness model, combining HTA, MCDA, values and ethics. It supports systematic consideration of all components of decision and available evidence for greater transparency. Further testing and validation is needed to build up MCDA approaches combined with pragmatic HTA in healthcare decisionmaking.     

Cyclophosphamide treatment induces rejection of established P815 mastocytoma by enhancing CD4 priming and intratumoral infiltration of P1E/H‐2Kd‐specific CD8+ T cells

There is increasing evidence that the effect of chemotherapy on tumor growth is not cell autonomous but relies on the immune system. The objective of this study was therefore to decipher the cellular and molecular mechanisms underlying the role of innate and adaptive immunity in chemotherapy‐induced tumor rejection. Treatment of DBA/2 mice bearing P815 mastocytoma with cyclophosphamide induced rejection and long‐term protection in a CD4‐ and CD8‐dependent manner. A population of inflammatory‐type dendritic cells was dramatically expanded in the lymph nodes of mice that rejected the tumor and correlated with CD4‐dependent infiltration, in tumor bed, of tumor‐specific CD8⁺ T lymphocytes. Our data point to a major role of CD4⁺ T cells in inducing chemokine expression in the tumor, provoking migration of tumor‐specific CXCR3⁺ CD8⁺ T lymphocytes. Importantly, the analysis of CD8⁺ T cells specific to P1A/H‐2L^d and P1E/H‐2K^d revealed that cyclophosphamide altered the P815‐specific CD8 T repertoire by amplifying the response specific to the mutated P1E antigen.     

Human bone morphogenetic protein‐7 does not counteract aristolochic acid‐induced renal toxicity

Aristolochic acids (AA) are nephrotoxic and profibrotic agents, leading to chronic kidney disease. As some controversial studies have reported a nephroprotective effect of exogenous recombinant human bone morphogenetic protein (rhBMP)‐7 in several models of renal fibrosis, we investigated the putative effect of rhBMP‐7 to prevent progressive tubulointerstitial damage after AA intoxication in vitro and in vivo. In vitro, the toxicity of AA on renal tubular cells was demonstrated by an increase in vimentin as well as a decrease in β‐catenin expressions, reflecting a dedifferentiation process. Increased fibronectin and interleukin‐6 levels were measured in the supernatants. Enhanced α‐SMA mRNA levels associated to decreased E‐cadherin mRNA levels were also measured. Incubation with rhBMP‐7 only prevented the increase in vimentin and the decrease in β‐catenin expressions. In vivo, in a rat model of AA nephropathy, severe tubulointerstitial lesions induced by AA after 10 and 35 days (collagen IV deposition and tubular atrophy), were not prevented by the rhBMP‐7 treatment. Similarly, rhBMP‐7 did not ameliorate the significant increase in urinary concentrations of transforming growth factor‐β. In summary, our in vitro data demonstrated a poor beneficial effect of rhBMP‐7 to reverse cell toxicity while, in vivo, there was no beneficial effect of rhBMP‐7. Therefore, further investigations are needed to confirm the exact role of BMP‐7 in progressive chronic kidney disease. Copyright © 2015 John Wiley & Sons, Ltd.     

Significance of physicochemical forms of storage in microalgae in predicting copper transfer to filter-feeding oysters (Crassostrea gigas)

Copper distribution has been examined in two microalgae (Haslea ostrearia, Diatom; Tetraselmis suecica, Prasinophyceae) exposed to Cu at 30 microg/L(-1). Exchangeable copper linked at the cell surface was desorbed using 8-hydroxyquinoline-5-sulfonate as complexing agent. Then, incorporated copper was separated between soluble and insoluble fractions. In addition, algae were resuspended in acid solutions, the pHs of which covered the range existing in the digestive tract of bivalves. Considering that the soluble fraction is the most easily transferred in the food chain and that exchangeable Cu is easily desorbed, the percentages of Cu potentially available in microalgae have been assessed. These percentages have been compared with those retained in oysters Crassostrea gigas fed with contaminated microalgae in previous studies. In H. ostrearia, the potentially available fraction of Cu (90%) was very similar to the percentage retained by oysters (93%) when the bivalves were acclimated to this food for 3 weeks. Only half (21%) of the potentially available Cu of T. suecica (42%) was readily assimilated in oysters after 3 weeks. This is in agreement with the results of the desorption tests at physiological pHs which showed that only 15-25% of Cu was lost, despite solubilization of other constituents of T. suecica as demonstrated by the decrease in their dry weight. Bioavailability determined from metal speciation in food allows a relevant prediction of the trophic transfer in the case of H. ostrearia, but caution is recommended in generalizing this mode of assessment as shown in the case of T. suecica.     

Ezh2 and Runx1 Mutations Collaborate to Initiate Lympho-Myeloid Leukemia in Early Thymic Progenitors

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A validated capillary electrophoresis method to check for batch-to-batch consistency during recombinant human glycosylated interleukin-7 production campaigns

This work reports the validation of a simple CZE method to be used in quality control of recombinant human glycosylated interleukin-7 (rhIL-7) batches produced in Chinese Hamster Ovary (CHO) cells. The separation buffer was a 25 mM sodium borate at pH 10 containing 12 mM diaminobutane (DAB) used as a dynamic coating agent of the capillary. This method allowed the separation of seven peaks ranging from low to high sialylated glycoforms. An extensive study on conditioning methods of the capillary has been conducted to yield repeatable results. Excellent RSD of EOF mobility (less than 0.6%) was obtained when conditioning included capillary equilibration under virtual analyses and storage in 0.1 M NaOH overnight. Method specificity has been demonstrated to be able to discriminate different rhIL-7 glycoforms produced in CHO from formulation matrix. Linearity was demonstrated between 0.5 and 4 mg/mL. LOQ was 0.5 mg/mL. Repeatability (RSD < 1.4 and 3.3% for t_m and A%, respectively), intermediate precision of inter-day (RSD < 2.1 and 4.5), inter-analyst (RSD < 2.0 and 3.0) and inter-equipment (RSD < 3.8 and 3.7 for electrophoretic mobility and A%, respectively) were all very satisfactory. Evaluation of robustness revealed that pH and DAB concentration are critical parameters in the method while slight alteration of ionic strength of electrolyte or change of capillary source did not affect the results. Finally the method was shown to provide reliable informations to address comparability studies and batch-to-batch consistency of biomanufactured rhIL-7.     

Developmental abnormalities induced by X-irradiation in p53 deficient mice

In order to assess the influence of p53 inactivation on radiation-induced developmental effects, male mice heterozygous for the wild-type p53 allele (mimicking the human Li-Fraumeni syndrome) were crossed with C57BL females, and their heterozygous p53+/- progeny were mated with each other to obtain p53+/-, p53-/- and p53+/+ embryos. Pregnant females were X-irradiated with 0.5 Gy on days 1 (pre-implantation period), 8 or 11 (organogenesis period) of gestation. Dissection of the pregnant females occurred on day 19 of gestation. The p53 genotype of the foetuses was determined by PCR from small pieces of soft tissues. Exencephaly was the only external malformation found in the control group. It affected essentially p53-/- female foetuses. A number of p53+/- and p53+/- control foetuses also showed dwarfism, or underdevelopment. In the group irradiated on day 1, the frequency of abnormal foetuses was, paradoxically, lower than that found in the control group. As in that group, exencephaly and dwarfism constituted the only anomalies that were found. Exencephaly affected only homozygous p53-/- females, while dwarfism concerned either p53-/- or p53+/- foetuses, with a majority of females. Irradiation on day 8 of gestation induced a significant increase in the frequency of abnormal foetuses, compared to the control group. Various malformations were observed in addition to exencephaly, including gastroschisis, polydactyly, cephalic oedema and cleft palate. All malformed foetuses were either homozygous p53-/- or heterozygous p53+/- while most affected foetuses were females, as was the case for dwarf individuals. Irradiation on day 11 did not cause an increase in the frequency of abnormal foetuses, in comparison with the controls. However, a large spectrum of external malformations was again noticed, as in the group irradiated on day 8. All affected foetuses were homozygous p53-/- and there were slightly more abnormal females than males (3 out of 5). No dwarfs were found in this group. Overall, these results confirm the importance of the p53 tumour-suppressor protein for normal embryonic development. They clearly show that homozygous p53-/- (or heterozygous p53+/- to a lesser extent) foetuses are more at risk for radiation-induction of external malformations during the organogenesis period, and that the risk of developing such malformations is much higher for females than for males. In contrast to results published very recently by others, we found that malformed foetuses resulting from an X-irradiation with a low-dose during the highly sensitive period of gastrulation are able to survive to birth.