The need for data harmonization—a response to Boden and Ozonoff

Boden and Ozonoff's undercount estimates in their recent Commentary rely on three assumptions for which no quantitative literature references are provided. Alternatively, we show that findings in both studies and published data indicate lower upper-bound estimates for the undercount range. Am. J. Ind. Med. 53:854–855, 2010. © 2010 Wiley-Liss, Inc.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/77520/1/20840_ftp.pd

Dissociation of mitochondrial depolarization from cytochrome c release during apoptosis induced by photodynamic therapy

Photodynamic therapy (PDT) with the phthalocyanine photosensitizer Pc 4 induces rapid apoptosis in mouse lymphoma (LY-R) cells, initiating with the release of cytochrome c from mitochondria. It has been proposed that the opening of the mitochondrial membrane permeability transition pores, which results in the dissipation of the mitochondrial membrane potential (Δψm), is essential for the escape of cytochrome c from mitochondria into the cytosol as well as for apoptotic cell death. Therefore, we have assessed the correlation between the loss of Δψm and the release of cytochrome c following PDT. Treatment of LY-R cells with 300 nM Pc 4 and 60, 90 or 120 mJ/cm2of red light resulted in apoptosis of 80–90% of the cells, accompanied by >20-fold elevation in caspase-3-like activity within one h. At all 3 doses of PDT employed here, the majority of the cytochrome c was released from mitochondria at 15 min after irradiation, as determined by an immunohistochemical method. In contrast, the loss of Δψm following PDT, as monitored by the uptake of JC-1 or Rh-123, depended on the PDT dose and the post-treatment time. In spite of the release of cytochrome c at 15 min after each of the 3 doses, a corresponding loss of Δψm was observed only for those cells that received the highest dose of PDT. Virtually all cells that received one of the lower doses of PDT (300 nM Pc 4 plus 60 or 90 mJ/cm2) maintained normal Δψm. Hence, our results support the conclusion that the release of cytochrome c from mitochondria resulting from Pc 4-PDT-induced photodamage is independent of the loss of Δψm. Therefore, it is important to consider a range of doses of this or other apoptotic stimuli in deciphering the relationship of metabolic responses that contribute to apoptosis. © 2001 Cancer Research Campaign http://www.bjcancer.co

A few key theoretical issues of importance in modern molecular electrochemistry

International audienceThis opinion paper details three typical cases in which new theoretical concepts need to be implemented in molecular electrochemistry in order to rationalize experimental results obtained in nanoscale cells or performed in new electrolytic media such as RTILs

Mathematical Modelling of Nitric Oxide Release Caused by Exocytosis and Determination of a Stellate Neuron Activity Function in Rat Brain

In this work we report the results of the mathematical modelling of NO◦ -release by neurons considering a series of Gaussian bursts, together with its transport in the brain by diffusion. Our analysis relies on the NO◦ -release from a neuron monitored before, during and after its patch-clamp stimulation as detected by an ultramicroelectrode introduced into a slice of living rat’s brain. The parameters of the neuron activity function have been obtained by numerical fitting of experimental data with simulated theoretical results. Within our initial hypothesis about the Gaussian decomposition of NO◦ -release that allowed drawing qualitative and quantitative conclusions about the considered neuron activity function. It is noted that since the activity function can be readily modified this signal processing may be adapted to the treatment of other and maybe more physiologically relevant hypotheses

Theoretical concepts underlying ECL generation

International audienc

Theoretical Modeling and Optimization of the Detection Performance: a New Concept for Electrochemical Detection of Proteins in Microfluidic Channels

In this work, we present a complete theoretical analysis of a new concept of electrochemical detector for application in proteomics upon considering two band microelectrodes performing in generator-collector mode. This concept of an original electrochemical detector is aimed at the detection of proteins following their separation in microfluidic biochips. The theoretical analysis is based on the use of the time-dependent coordinate transformation which allows performing precise modeling for a wide range of the key parameters governing the electrochemical detector performance. This allows defining a precise optimization procedure for its best efficiency upon considering the qualitative and quantitative effects of each of the main operational parameters

The association of the original OSHA chemical hazard communication standard with reductions in acute work injuries/illnesses in private industry and the industrial releases of chemical carcinogens

Background OSHA predicted the original chemical Hazard Communication Standard (HCS) would cumulatively reduce the lost workday acute injury/illness rate for exposure events by 20% over 20 years and reduce exposure to chemical carcinogens. Methods JoinPoint trend software identified changes in the rate of change of BLS rates for days away from work for acute injuries/illnesses during 1992–2009 for manufacturing and nonmanufacturing industries for both chemical, noxious or allergenic injury exposure events and All other exposure events. The annual percent change in the rates was used to adjust observed numbers of cases to estimate their association with the standard. A case‐control study of EPA's Toxic Release Inventory 1988–2009 data compared carcinogen and non‐carcinogens' releases. Results The study estimates that the HCS was associated with a reduction in the number of acute injuries/illnesses due to chemical injury exposure events over the background rate in the range 107,569–459,395 (Hudson method/modified BIC model) depending on whether the HCS is treated as a marginal or sole factor in the decrease. Carcinogen releases have declined at a substantially faster rate than control non‐carcinogens. Discussion The previous HCS standard was associated with significant reductions in chemical event acute injuries/illnesses and chemical carcinogen exposures. Am. J. Ind. Med. 57:138–152, 2014. © 2013 Wiley Periodicals, Inc.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/102719/1/ajim22269.pd