A
bstract
The exclusive photoproduction reactions
γp
→
J/ψ
(1
S
)
p
and
γp
→
ψ
(2
S
)
p
have been measured at an
ep
centre-of-mass energy of 318 GeV with the ZEUS detector at HERA using an integrated ...luminosity of 373 pb
−
1
. The measurement was made in the kinematic range 30
< W <
180 GeV,
Q
2
<
1 GeV
2
and |
t
|
<
1 GeV
2
, where
W
is the photon-proton centre-of-mass energy,
Q
2
is the photon virtuality and
t
is the squared four-momentum transfer at the proton vertex. The decay channels used were
J/ψ
(1
S
)
→ μ
+
μ
−
,
ψ
(2
S
)
→ μ
+
μ
−
and
ψ
(2
S
)
→ J/ψ
(1
S
)
π
+
π
−
with subsequent decay
J/ψ
(1
S
)
→ μ
+
μ
−
. The ratio of the production cross sections,
R
=
σ
ψ
(2
S
)
/σ
J/ψ
(1
S
)
, has been measured as a function of
W
and |
t
| and compared to previous data in photoproduction and deep inelastic scattering and with predictions of QCD-inspired models of exclusive vector-meson production, which are in reasonable agreement with the data.
Chromatography is undoubtedly the workhorse of downstream processes, affording high resolution for bioseparations. At the same time, it has the notoriety of being the single largest cost center in ...downstream processing and of being a low-throughput operation. Consequently, ‘chromatography alternatives’ are an attractive proposition, even if only a reduction in the extent of use of packed beds can be realized. This paper reviews the current state of unit operations posing as chromatography alternatives — including membrane filtration, aqueous two-phase extraction, three-phase partitioning, precipitation, crystallization, monoliths and membrane chromatography — and their potential to do the unthinkable.
There is large literature describing in vitro experiments on heat shock protein (hsp)B1 but understanding of its function in vivo is limited to studies in mice overexpressing human hspB1 protein. ...Experiments in cells have shown that hspB1 has chaperone activity, a cytoprotective role, regulates inflammatory gene expression, and drives cell proliferation. To investigate the function of the protein in vivo we generated hspB1-deficient mice. HspB1-deficient fibroblasts display increased expression of the pro-inflammatory cytokine, interleukin-6, compared to wild-type cells, but reduced proliferation. HspB1-deficient fibroblasts exhibit reduced entry into S phase and increased expression of cyclin-dependent kinase inhibitors p27(kip1) and p21(waf1). The expression of hspB1 protein and mRNA is also controlled by the cell cycle. To investigate the physiological function of hspB1 in regulating inflammation and cell proliferation we used an excisional cutaneous wound healing model. There was a significant impairment in the rate of healing of wounds in hspB1-deficient mice, characterised by reduced re-epithelialisation and collagen deposition but also increased inflammation. HspB1 deficiency augments neutrophil infiltration in wounds, driven by increased chemokine (C-X-C motif) ligand 1 expression. This appears to be a general mechanism as similar results were obtained in the air-pouch and peritonitis models of acute inflammation.
Background Aneurysmal subarachnoid hemorrhage (aSAH) is a devastating problem. Overall, the mortality rate associated with aSAH is 32% to 67%, which makes it the most lethal type of hemorrhagic ...stroke. Once the aneurysm has been treated, cerebral vasospasm is the leading cause of morbidity and mortality associated with aSAH. Thus, ability to effectively prevent or treat cerebral vasospasm could result in significantly improved survival and quality of life for aSAH patients. Unfortunately, partly because of poor understanding of the mechanisms of vasospasm, current diagnosis and treatment can be inconsistent and/or ineffective. Current treatment methods include primarily medical therapy and endovascular methods. Alone, or in combination, these measures can be of benefit in some patients. However, they are not uniformly efficacious and, on an individual basis, they can present significant risks. These risks include stroke, cardiovascular compromise, and death. More effective diagnosis and treatment strategies could significantly improve patient outcomes after aSAH. Unfortunately, clinically reliable biomarker for cerebral vasospasm has yet to be identified. Biomarker discovery may facilitate earlier diagnosis of vasospasm and improved monitoring of the response to treatment. It may help in stratifying patients into categories of risk to develop vasospasm, which could subsequently guide therapy. Indeed, biomarker research may suggest “vasospasm phenotypes” that can be used to guide the most effective type of therapy for that particular patient. The purpose of this manuscript is to review the current cerebral vasospasm biomarker literature. Methods An extensive PubMed literature search was performed. We identified over 100 English language articles with key words cerebral vasospasm and biomarkers. Some of these articles and related references were used as the basis of this review. We focused on related human studies performed within the past 10 years. Results In this review, we focus on recent work identifying molecular markers of cerebral vasospasm following aSAH and the current understanding of the utility of these markers. We highlight novel approaches such as the use of cellular microparticles for the evaluation of cerebral vasospasm. Conclusions Although multiple molecules have been proposed, no single molecule has been shown to be a clinically reliable biomarker for cerebral vasospasm. This is not surprising based on the complex pathogenesis of cerebral vasospasm. Indeed, it is unlikely that a single biomarker will be clinically effective and reliable for predicting cerebral vasospasm. Instead, cerebral vasospasm may be best predicted by a panel of markers and the temporal progression of their relative levels after aSAH. Many such candidate molecules are reviewed herein and can be categorized as markers of cell damage, inflammation, changes in metabolism and vascular tone as well as microparticle-derived biomarkers. Among these, microparticle-derived biomarkers seem to be promising and lend themselves to further study. Biomarker discovery may facilitate earlier diagnosis of vasospasm and improved monitoring of the response to treatment. Ultimately, it may guide in the development of safer and more effective therapies for the most dreaded of aSAH complications.
Adolescent binge alcohol abuse induces long-term changes in gene expression, which impacts the physiological stress response and memory formation, two functions mediated in part by the ventral (VH) ...and dorsal (DH) hippocampus. microRNAs (miRs) are small RNAs that play an important role in gene regulation and are potential mediators of long-term changes in gene expression. Two genes important for regulating hippocampal functions include brain-derived neurotrophic factor (BDNF) and sirtuin-1 (SIRT1), which we identified as putative gene targets of miR-10a-5p, miR-26a, miR-103, miR-495. The purpose of this study was to quantify miR-10a-5p, miR-26a, miR-103, miR-495 expression levels in the dorsal and ventral hippocampus of male Wistar rats during normal pubertal development and then assess the effects of repeated binge-EtOH exposure. In addition, we measured the effects of binge EtOH-exposure on hippocampal Drosha and Dicer mRNA levels, as well as the putative miR target genes, BDNF and SIRT1. Overall, mid/peri-pubertal binge EtOH exposure altered the normal expression patterns of all miRs tested in an age- and brain region-dependent manner and this effect persisted for up to 30 days post-EtOH exposure. Moreover, our data revealed that mid/peri-pubertal binge EtOH exposure significantly affected miR biosynthetic processing enzymes, Drosha and Dicer. Finally, EtOH-induced significant changes in the expression of a subset of miRs, which correlated with changes in the expression of their predicted target genes. Taken together, these data demonstrate that EtOH exposure during pubertal development has long-term effects on miRNA expression in the rat hippocampus.
Adolescence is a dynamic and important period of brain development however, little is known about the long-term neurobiological consequences of alcohol consumption during puberty. Our previous ...studies showed that binge-pattern ethanol (EtOH) treatment during pubertal development negatively dysregulated the responsiveness of the hypothalamo-pituitary-adrenal (HPA) axis, as manifested by alterations in corticotrophin-releasing hormone (CRH), arginine vasopressin (AVP), and corticosterone (CORT) during this time period. Thus, the primary goal of this study was to determine whether these observed changes in important central regulators of the stress response were permanent or transient. In this study, juvenile male Wistar rats were treated with a binge-pattern EtOH treatment paradigm or saline alone for 8 days. The animals were left undisturbed until adulthood when they received a second round of treatments consisting of saline alone, a single dose of EtOH, or a second binge-pattern treatment paradigm. The results showed that pubertal binge-pattern EtOH exposure induced striking long-lasting alterations of many HPA axis parameters. Overall, our data provide strong evidence that binge-pattern EtOH exposure during pubertal maturation has long-term detrimental effects for the healthy development of the HPA axis.
Adolescent binge alcohol exposure has long-lasting effects on the expression of hypothalamic genes that regulate the stress response, even in the absence of subsequent adult alcohol exposure. This ...suggests that alcohol can induce permanent gene expression changes, potentially through epigenetic modifications to specific genes. Epigenetic modifications can be transmitted to future generations therefore, and in these studies we investigated the effects of adolescent binge alcohol exposure on hypothalamic gene expression patterns in the F1 generation offspring. It has been well documented that maternal alcohol exposure during fetal development can have devastating neurological consequences. However, less is known about the consequences of maternal and/or paternal alcohol exposure outside of the gestational time frame. Here, we exposed adolescent male and female rats to a repeated binge EtOH exposure paradigm and then mated them in adulthood. Hypothalamic samples were taken from the offspring of these animals at postnatal day (PND) 7 and subjected to a genome-wide microarray analysis followed by qRT-PCR for selected genes. Importantly, the parents were not intoxicated at the time of mating and were not exposed to EtOH at any time during gestation therefore the offspring were never directly exposed to EtOH. Our results showed that the offspring of alcohol-exposed parents had significant differences compared to offspring from alcohol-naïve parents. Specifically, major differences were observed in the expression of genes that mediate neurogenesis and synaptic plasticity during neurodevelopment, genes important for directing chromatin remodeling, posttranslational modifications or transcription regulation, as well as genes involved in regulation of obesity and reproductive function. These data demonstrate that repeated binge alcohol exposure during pubertal development can potentially have detrimental effects on future offspring even in the absence of direct fetal alcohol exposure.
EtOH exposure in male rats increases corticotropin-releasing hormone (CRH) mRNA in the paraventricular nucleus of the hypothalamus (PVN), a brain region responsible for coordinating stress and ...anxiety responses. In this study we identified the molecular mechanisms involved in mediating these effects by examining the direct effects of EtOH on CRH promoter activity in a neuronal cell line derived from the PVN (IVB). In addition, we investigated the potential interactions of EtOH and glucocorticoids on the CRH promoter by concomitantly treating cells with EtOH and the glucocorticoid receptor (GR) antagonist RU486, and by sequentially deleting GR binding sites within glucocorticoid response element (GRE) on the CRH promoter. Cells were transiently transfected with a firefly luciferase reporter construct containing 2.5 kb of the rat wild type (WT) or mutated CRH promoter. Our results showed that EtOH treatment induced a biphasic response in CRH promoter activity. EtOH exposure for 0.5 h significantly decreased promoter activity compared to vehicle treated controls, whereas promoter activity was significantly increased after 2.0 h of EtOH exposure. Treatment with RU486, or deletion of the GR binding sites 1 and 2 within the GRE, abolished the EtOH-induced increase in the promoter activity, however did not affect EtOH-induced decrease in CRH promoter activity at an earlier time point. Overall, our data suggest that alcohol exposure directly regulates CRH promoter activity by interfering with the normal feedback mechanisms of glucocorticoids mediated by GR signaling at the GRE site of the CRH promoter.
PDF
