Proof-of-concept human laboratory study for protracted abstinence in alcohol dependence: effects of gabapentin

There is a need for safe medications that can effectively support recovery by treating symptoms of protracted abstinence that may precipitate relapse in alcoholics, e.g. craving and disturbances in sleep and mood. This proof-of-concept study reports on the effectiveness of gabapentin 1200 mg for attenuating these symptoms in a non-treatment-seeking sample of cue-reactive, alcohol-dependent individuals. Subjects were 33 paid volunteers with current Diagnostic and Statistical Manual of Mental Disorders-IV alcohol dependence and a strength of craving rating 1 SD or greater for alcohol than water cues. Subjects were randomly assigned to gabapentin or placebo for 1 week and then participated in a within-subjects trial where each was exposed to standardized sets of pleasant, neutral and unpleasant visual stimuli followed by alcohol or water cues. Gabapentin was associated with significantly greater reductions than placebo on several measures of subjective craving for alcohol as well as for affectively evoked craving. Gabapentin was also associated with significant improvement on several measures of sleep quality. Side effects were minimal, and gabapentin effects were not found to resemble any major classes of abused drugs. Results suggest that gabapentin may be effective for treating the protracted abstinence phase in alcohol dependence and that a randomized clinical trial would be an appropriate next step. The study also suggests the value of cue-reactivity studies as proof-of-concept screens for potential antirelapse drugs.     

Multiplexed expression and screening for recombinant protein production in mammalian cells

Background  

A variety of approaches to understanding protein structure and function require production of recombinant protein. Mammalian based expression systems have advantages over bacterial systems for certain classes of protein but can be slower and more laborious. Thus the availability of a simple system for production and rapid screening of constructs or conditions for mammalian expression would be of great benefit. To this end we have coupled an efficient recombinant protein production system based on transient transfection in HEK-293 EBNA1 (HEK-293E) suspension cells with a dot blot method allowing pre-screening of proteins expressed in cells in a high throughput manner.     

Possible impacts of non-native plant,pathogen, invertebrate and fish taxa on the indigenous ichthyofauna in South African estuaries: a preliminary review

Biological Invasions - We review the possible impacts of non-native biota on the indigenous fishes of South African estuaries, including macrophytes, algae, pathogens, invertebrates, and fishes....     

Chronic rapamycin treatment or lack of S6K1 does not reduce ribosome activity in vivo

Reducing activity of the mTORC1/S6K1 pathway has been shown to extend lifespan in both vertebrate and invertebrate models. For instance, both pharmacological inhibition of mTORC1 with the drug rapamycin or S6K1 knockout extends lifespan in mice. Since studies with invertebrate models suggest that reducing translational activity can increase lifespan, we reasoned that the benefits of decreased mTORC1 or S6K1 activity might be due, at least in part, to a reduction of general translational activity. Here, we report that mice given a single dose of rapamycin have reduced translational activity, while mice receiving multiple injections of rapamycin over 4 weeks show no difference in translational activity compared with vehicle-injected controls. Furthermore, mice lacking S6K1 have no difference in global translational activity compared with wild-type littermates as measured by the percentage of ribosomes that are active in multiple tissues. Translational activity is reduced in S6K1-knockout mice following single injection of rapamycin, demonstrating that rapamycin’s effects on translation can occur independently of S6K1. Taken together, these data suggest that benefits of chronic rapamycin treatment or lack of S6K1 are dissociable from potential benefits of reduced translational activity, instead pointing to a model whereby changes in translation of specific subsets of mRNAs and/or translation-independent effects of reduced mTOR signaling underlie the longevity benefits.     

Characterization in vitro and in vivo of hammerhead ribozymes directed against murine tumor necrosis factoralpha.

A hammerhead ribozyme directed against murine TNFalpha (mTNFalpha) mRNA has been constructed. In vitro studies showed that this ribozyme was released from the parent molecule by flanking cis-acting hammerhead and hairpin ribozymes. This same anti-mTNFalpha ribozyme specifically cleaved both synthetically derived substrate RNA and mTNFalpha mRNA within a pool of total cellular RNA. Endogenous delivery of this anti-mTNFalpha ribozyme via the self-cleaving cassette reduced mTNFalpha mRNA and protein levels in lipopolysaccharide (LPS)-stimulated, stably transfected murine macrophage RAW 264.7 cells. When complexed to liposomes and exogenously delivered to mouse peritoneal macrophages, the same ribozyme, with and without the cis-acting ribozymes, reduced mTNFalpha protein levels. However, an irrelevant ribozyme delivered in an identical fashion was also effective at reducing mTNFalpha protein levels. These data suggest that anti-mTNFalpha ribozymes can be constructed which efficiently cleave mTNFalpha mRNA, but irrelevant RNA/liposome complexes also effectively limit TNFalpha mRNA expression and can mimic functional ribozyme activity under in vitro conditions.     

Characterizing the Data in Online Companion-dog Obituaries to Assess Their Usefulness as a Source of Information about Human–Animal Bonds

Online pet obituary sites host hundreds of obituaries regarding the passing of companion animals. Often composed by the owner or primary caretaker of the animal, they are a potential source of data about human–animal bonds where there were strong positive human emotions surrounding the animal at point of death. The aim of the present study was to characterize on-line pet obituaries and to evaluate their usefulness as a source of information on the human–animal bond. One hundred and thirty full obituaries of dogs were studied. Where the role of the writer could be identified, the majority of obituary writers identified themselves as a female parental figure to the dog (34.6%); however, obituaries were also written by male parental figures (7.7%) and children (5.4%). Most obituaries (60%) fell within the 100-400 words length range. Obituaries were seen to express several key concepts. For instance, dogs were described as “child-like,” “part of the family,” showing “sympathy” and/or “gratitude” to the owner, and having a “sense of humor.” For their part, writers expressed “guilt” over the dog’s death, discussed a concept of the “afterlife” and noted an “instant connection” between themselves and the dog. A high proportion of the obituaries discussed the afterlife (51%) and indicated that the dog was considered part of the family (49%). There were some significant associations between concept usage within obituaries. Dogs that were described as “child-like” were more often perceived to be in an “afterlife” and to have had an “instant connection” with obituary writers (x² = 38.08, p < 0.001). We conclude that online pet obituaries can be a valuable source of information on human feelings surrounding a companion animal death.     

Increased reactivity in the mesenteric artery of spontaneously hypertensive rats to phorbol ester

The contraction responses of mesenteric artery from 10 week old spontaneously hypertensive rats (SHRs) and normotensive Wistar Kyoto controls (WKYs) to phorbol 12, 13 - dibutyrate (PDBu) and agents acting on the potential-operated calcium channels were compared. The vessels from the SHR were significantly more sensitive to PDBu than those from the WKY. The PDBu-induced contractions were inhibited by nifedipine. The vessels from the SHR were also more sensitive to Bay K 8644 and KCl than the WKY. Low concentrations of PDBu (1 nM) potentiated the KCl contraction significantly more in the SHR than the WKY. It is suggested that the increased reactivity to PDBu in the SHR may in part be related to changes in the activity of the potential-operated calcium channels.     

Pyruvate dehydrogenase phosphatase 1 (<Emphasis Type="Italic">PDP1</Emphasis>) null mutation produces a lethal infantile phenotype

Pyruvate dehydrogenase phosphatase deficiency has previously only been confirmed at the molecular level in two brothers and two breeds of dog with exercise intolerance. A female patient, who died at 6 months, presented with lactic acidemia in the neonatal period with serum lactate levels ranging from 2.5 to 17 mM. Failure of dichloroacetate to activate the PDH complex in skin fibroblasts was evident, but not in early passages. A homozygous c.277G > T (p.E93X) nonsense mutation in the PDP1 gene was identified in genomic DNA and immunoblotting showed a complete absence of PDP1 protein in mitochondria. Native PDHC activity could be restored by the addition of either recombinant PDP1 or PDP2. This highlights the role of PDP2, the second phosphatase isoform, in PDP1-deficient patients for the first time. We conclude that the severity of the clinical course associated with PDP1 deficiency can be quite variable depending on the exact nature of the molecular defect.     

Stimulus responsive elastin biopolymers: Applications in medicine and biotechnology

Elastin-like polypeptides (ELPs) are artificial polypeptides, derived from Val-Pro-Gly-Xaa-Gly (VPGXG) pentapeptide repeats found in human tropoelastin, that reversibly coacervate above a critical temperature. Genetically encodable ELPs are monodisperse, stimuli responsive, and biocompatible, properties that make them attractive for drug delivery and tissue engineering. The potential of ELPs to self-assemble into nanostructures in response to environmental triggers is another interesting feature of these polypeptides that promises to lead to a host of new applications.