High-Throughput Proteomics Detection of Novel Splice Isoforms in Human Platelets

Alternative splicing (AS) is an intrinsic regulatory mechanism of all metazoans. Recent findings suggest that 100% of multiexonic human genes give rise to splice isoforms. AS can be specific to tissue type, environment or developmentally regulated. Splice variants have also been implicated in various diseases including cancer. Detection of these variants will enhance our understanding of the complexity of the human genome and provide disease-specific and prognostic biomarkers. We adopted a proteomics approach to identify exon skip events - the most common form of AS. We constructed a database harboring the peptide sequences derived from all hypothetical exon skip junctions in the human genome. Searching tandem mass spectrometry (MS/MS) data against the database allows the detection of exon skip events, directly at the protein level. Here we describe the application of this approach to human platelets, including the mRNA-based verification of novel splice isoforms of ITGA2, NPEPPS and FH. This methodology is applicable to all new or existing MS/MS datasets

Acetaminophen (Paracetamol) Induces Hypothermia During Acute Cold Stress.

BACKGROUND Acetaminophen is an over-the-counter drug used to treat pain and fever, but it has also been shown to reduce core temperature (T c) in the absence of fever. However, this side effect is not well examined in humans, and it is unknown if the hypothermic response to acetaminophen is exacerbated with cold exposure. OBJECTIVE To address this question, we mapped the thermoregulatory responses to acetaminophen and placebo administration during exposure to acute cold (10 °C) and thermal neutrality (25 °C). METHODS Nine healthy Caucasian males (aged 20-24 years) participated in the experiment. In a double-blind, randomised, repeated measures design, participants were passively exposed to a thermo-neutral or cold environment for 120 min, with administration of 20 mg/kg lean body mass acetaminophen or a placebo 5 min prior to exposure. T c, skin temperature (T sk), heart rate, and thermal sensation were measured every 10 min, and mean arterial pressure was recorded every 30 min. Data were analysed using linear mixed effects models. Differences in thermal sensation were analysed using a cumulative link mixed model. RESULTS Acetaminophen had no effect on T c in a thermo-neutral environment, but significantly reduced T c during cold exposure, compared with a placebo. T c was lower in the acetaminophen compared with the placebo condition at each 10-min interval from 80 to 120 min into the trial (all p  0.05). CONCLUSION This preliminary trial suggests that acetaminophen-induced hypothermia is exacerbated during cold stress. Larger scale trials seem warranted to determine if acetaminophen administration is associated with an increased risk of accidental hypothermia, particularly in vulnerable populations such as frail elderly individuals

Miocene diatom biostratigraphy at ODP Sites 689, 690, 1088, 1092 (Atlantic sector of the Southern Ocean)

AbstractFour ODP sites located between 64°S and 41°S in the eastern Atlantic sector of the Southern Ocean were investigated to refine the Miocene diatom biostratigraphic zonation tied to the geomagnetic chronology. The Miocene diatom stratigraphy from two sites located on Maud Rise (ODP Leg 113) is revised considering the progress in diatom biostratigraphic research, diatom taxonomy and magnetostratigraphic age assignment during the past 10 years. A new diatom zonation was erected for Site 1092 (ODP Leg 177) located on Meteor Rise integrating a magnetostratigraphic interpretation of the shipboard data. This zonation was also applied to Site 1088 (ODP Leg 177) located on Astrid Ridge. The study is focused to Middle and Upper Miocene sequences. It reveals latitudinal differentiations in stratigraphic species ranges and species occurrence pattern that are related to latitudinal differences in surface water masses reflecting the climatic development of the Antarctic cryosphere. Considering the latitudinal differences two stratigraphic zonations are proposed that are applicable to the northern and southern zone of the Southern Ocean, respectively. The southern Southern Ocean Miocene diatom biostratigraphic zonation consists of 16 zones in which 11 represent new or modified zones. The northern biostratigraphic zonation contains 10 diatom zones allowing a stratigraphic resolution in the range of 0.2 to 2 m.y. This paper also includes the taxonomic transfer of seven Miocene diatom taxa from genus Nitzschia Hassal to Fragilariopsis Hustedt