Inhibitory G-protein Modulation of CNS Excitability.

Epilepsy represents a major health burden upon society. Approximately 30% of patients still remain symptomatic despite therapy. While not a current medicinal target for epilepsy, the family of inhibitory G-proteins appears to play an important role in this disease, as blocking their function in animal models increases both acute seizure susceptibility and the rate of spontaneous seizure development in kindling, a research model with parallels to epilepsy. The most abundant inhibitory G-protein in the brain is Go, composing roughly 2% of membrane bound protein. To further clarify the role of Go in epilepsy a Gnao1 gain-of-function mouse line (RGSi/G184S) was employed. Hippocampal slices from Gnao1 +/RGSi mice show enhanced epinephrine-mediated suppression of epileptiform burst firing of neurons demonstrating that Gnao1 +/RGSi mice have enhanced Go signaling. The aforementioned work lead me to hypothesize that C57BL/6J Gnao1 +/RGSi mice would be protected from kindling. In fact, the mice experience premature death, enhanced kindling susceptibility and over a ten-fold increase in frequency of electrical disturbances within their brain. C57BL/6J Gnao1 +/RGSi mice also display an unexpected loss of inhibitory signaling within specific brain regions. Interestingly, the mutation is only lethal on the C57BL/6J background. The progenitor 129S1/SvImJ strain demonstrates no change in seizure susceptibility or viability. A genome-wide SNP analysis identified a region on chromosome 17 between 41-70 megabases that affords protection from spontaneous lethality. Further, this region also reduces the rate at which mice develop seizures in response to kindling. This region was further refined to a subregion from 41-51 megabases which was found sufficient to afford protection to kindling. Consequently, I have identified two genomic loci, Gnao1 and the Chr17 modifier which I term Mogs1 (modifier of G-protein seizures), that should be examined as candidates in human epilepsy. Additionally, future use of this model should prove informative in assessing the utility of novel therapeutics to prevent the progression of epilepsy.PHDPharmacologyUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/107120/1/jkehrl_1.pd

Pulmonary responses in current smokers and ex-smokers following a two hour exposure at rest to clean air and fine ambient air particles

Abstract Background Increased susceptibility of smokers to ambient PM may potentially promote development of COPD and accelerate already present disease. Objectives To characterize the acute and subacute lung function response and inflammatory effects of controlled chamber exposure to concentrated ambient fine particles (CAFP) with MMAD ≤ 2.5 microns in ex-smokers and lifetime smokers. Methods Eleven subjects, aged 35–74 years, came to the laboratory 5 times; a training day and two exposure days separated by at least 3 weeks, each with a post-exposure visit 22 h later. Double-blind and counterbalanced exposures to “clean air” (mean 1.5 ± 0.6 μg/m3) or CAFP (mean 108.7 ± 24.8 μg/m3 ) lasted 2 h with subjects at rest. Results At 3 h post-exposure subjects’ DTPA clearance half-time significantly increased by 6.3 min per 100 μg/m3 of CAFP relative to “clean air”. At 22 h post-exposure they showed significant reduction of 4.3% per 100 μg/m3 in FEV1 and a significant DLCO decrease by 11.1% per 100 μg/m3 of CAFP relative to “clean air”. At both 3 h and 22 h the HDL cholesterol level significantly decreased by 4.5% and 4.1%, respectively. Other blood chemistries and markers of lung injury, inflammation and procoagulant activity were within the normal range of values at any condition. Conclusions The results suggest that an acute 2 h resting exposure of smokers and ex-smokers to fine ambient particulate matter may transiently affect pulmonary function (spirometry and DLCO) and increase DTPA clearance half-time. Except for a post exposure decrease in HDL no other markers of pulmonary inflammation, prothrombotic activity and lung injury were significantly affected under the conditions of exposure

Low-level ozone exposure induces airways inflammation and modifies cell surface phenotypes in healthy humans

The effects of low-level ozone exposure (0.08 ppm) on pulmonary function in healthy young adults are well known; however, much less is known about the inflammatory and immunomodulatory effects of low-level ozone in the airways. Techniques such as induced sputum and flow cytometry make it possible to examine airways inflammatory responses and changes in immune cell surface phenotypes following low-level ozone exposure. The purpose of this study was to determine if exposure to 0.08 parts per million ozone for 6.6 h induces inflammation and modifies immune cell surface phenotypes in the airways of healthy adult subjects. Fifteen normal volunteers underwent an established 0.08 part per million ozone exposure protocol to characterize the effect of ozone on airways inflammation and immune cell surface phenotypes. Induced sputum and flow cytometry were used to assess these endpoints 24 h before and 18 h after exposure. The results showed that exposure to 0.08 ppm ozone for 6.6 h induced increased airway neutrophils, monocytes, and dendritic cells and modified the expression of CD14, HLA-DR, CD80, and CD86 on monocytes 18 h following exposure. Exposure to 0.08 parts per million ozone is associated with increased airways inflammation and promotion of antigen-presenting cell phenotypes 18 hours following exposure. These findings need to be replicated in a similar experiment that includes a control air exposure

ICF, An Immunodeficiency Syndrome: DNA Methyltransferase 3B Involvement, Chromosome Anomalies, and Gene Dysregulation

The immunodeficiency, centromeric region instability, and facial anomalies syndrome (ICF) is the only disease known to result from a mutated DNA methyltransferase gene, namely, DNMT3B. Characteristic of this recessive disease are decreases in serum immunoglobulins despite the presence of B cells and, in the juxtacentromeric heterochromatin of chromosomes 1 and 16, chromatin decondensation, distinctive rearrangements, and satellite DNA hypomethylation. Although DNMT3B is involved in specific associations with histone deacetylases, HP1, other DNMTs, chromatin remodelling proteins, condensin, and other nuclear proteins, it is probably the partial loss of catalytic activity that is responsible for the disease. In microarray experiments and real-time RT-PCR assays, we observed significant differences in RNA levels from ICF vs. control lymphoblasts for pro- and anti-apoptotic genes (BCL2L10, CASP1, and PTPN13); nitrous oxide, carbon monoxide, NF-κB, and TNFa signalling pathway genes (PRKCH, GUCY1A3, GUCY1B3, MAPK13; HMOX1, and MAP4K4); and transcription control genes (NR2F2 and SMARCA2). This gene dysregulation could contribute to the immunodeficiency and other symptoms of ICF and might result from the limited losses of DNA methylation although ICF-related promoter hypomethylation was not observed for six of the above examined genes. We propose that hypomethylation of satellite 2at1qh and 16qh might provoke this dysregulation gene expression by trans effects from altered sequestration of transcription factors, changes in nuclear architecture, or expression of noncoding RNAs

Development of automotive engineering managers

Thesis: M.S., Massachusetts Institute of Technology, School of Industrial Management, 1960Includes bibliographical references (leaves [69]-71).by Howard H. Kehrl.M.S.M.S. Massachusetts Institute of Technology, School of Industrial Managemen