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M E Gibson

Publications and source records attributed to M E Gibson.

13 recordsLinked to original sources
PubMed2001

BAX contributes to apoptotic-like death following neonatal hypoxia-ischemia: evidence for distinct apoptosis pathways.

BACKGROUND: Hypoxic-ischemic (H-I) injury to the neonatal brain has been shown to result in rapid cell death with features of acute excitotoxicity/necrosis as well as prominent delayed cell death with features of apoptosis such as marked caspase-3 activation. BAX, a pro-apoptotic molecule, has been shown to be required for apoptotic neuronal cell death during normal development but the contribution of endogenous BAX in cell death pathways following H-I injury to the developing or adult brain has not been studied. MATERIALS AND METHODS: Bax +/+, +/-, and -/- mice at post-natal day 7 were subjected to unilateral carotid ligation followed by exposure to 45 minutes of 8% oxygen. At different timepoints following H-I, brain tissue was studied by conventional histology, immunohistochemistry, immunofluorescence, Western blotting, and enzymatic assay to determine the extent and type of cell injury as well as the amount of caspase activation. RESULTS: We found that bax -/- mice had significantly less (38%) hippocampal tissue loss than mice expressing bax. Some of the remaining cell death in bax -/- mice, however, still had features of apoptosis including evidence of nuclear shrinkage and caspase-3 activation. Though bax -/- mice had significantly decreased caspase-3 activation as compared to bax expressing mice following H-I, the density of cells with activated caspase-8 in the CA3 region of the hippocampus did not differ between bax +/- and bax -/- mice. CONCLUSIONS: These findings demonstrate that endogenous BAX plays a role in regulating cell death in the central nervous system (CNS) following neonatal H-I, a model of cerebral palsy. In addition, while BAX appears to modulate the caspase-3 activation following neonatal H-I, caspase-8 which is linked to death receptor activation, may contribute to apoptotic-like neuronal death in a BAX-independent manner.

Animals↗
PubMed1992

Synthesis of esters using a nylon-immobilized lipase in batch and continuous reactors.

Direct esterifications using a nylon-immobilized lipase from Candida cylindracea were carried out in batch and continuous-flow reactors. The immobilized enzyme was effective in catalyzing the synthesis of ethylpropionate, isoamylpropionate, and isoamylbutyrate. With ethanol dissolved in hexane as a substrate, the maximum initial esterification rate was 0.02 mole/(h x g of immobilized protein), but the enzyme was stable only when the substrate concentrations were lower than 0.2 M. With isoamyl alcohol in hexane as a substrate, esterification rates as high as 0.085 mole/(h x g of immobilized protein) were observed and the immobilized enzyme was stable over a much broader concentration range. However, in this case, the use of a solvent, such as hexane, was not necessary for esterification, and the enzyme could be employed in equimolar acid/alcohol mixtures. A packed-bed reactor was operated successfully for the continuous synthesis of esters. The reactor was stable for long periods of time, and the steady-state performance could be accurately predicted on the basis of batch reaction experiments.

Candida↗
PubMed1988

Bednets revisited- old idea, new angle.

Bednets, especially nets impregnated with repellant or insecticide, are attracting increasing interest as a key intervention against mosquito-borne parasites. They are relatively cheap and simple to use, and if arranged correctly can give protection against mosquitoes and other nocturnal biting flies. Such ideas however, are far from new, and in this essay, Steve Lindsay and Mary Gibson review some historical highlights of bednet development.

Journal Article↗
PubMed1987

Underestimation of gestational age by conventional crown-rump length dating curves.

Inaccuracies in gestational age assignment based on published crown-rump length data were noted in patients with known ovulation dates. In this study, we tested the hypothesis that crown-rump length data derived from pregnancies with known ovulation dates differ from those of menstrually timed pregnancies. Seventy-two previously infertile women with known dates of ovulation had crown-rump length measurements from 35-79 days postovulation. We transformed the data to menstrual age (gestational age) by adding 14 days to the date of ovulation and compared our crown-rump length values with those of two previous reports. At corresponding crown-rump length values, the gestational ages from our data differed from those in the previous studies. We suggest using crown-rump length dating curves based on ovulation-timed pregnancies because crown-rump length data derived from menstrually dated pregnancies underestimate true gestational age.

Embryonic and Fetal Development↗
PubMedDate not supplied

Transporting the incubator: effects upon a region of the adoption of guidelines for high-risk maternal transport.

OBJECTIVE: To inventory maternal transport practices and develop regional transport guidelines. STUDY DESIGN: A survey was administered to perinatal nursing directors of nine community hospitals in a rural region of Virginia. Items included personnel, training, equipment, vehicle, communication, and protocols. Following the survey, regional guidelines were developed using a collaborative process. Their use was promoted in the region. A post-intervention survey documented changes in transport practices. RESULTS: The pre-intervention survey showed wide variability in training and number of personnel and in availability of emergency equipment. Communication was via radio to a dispatcher. No hospital had standing orders or protocols for transport. Guidelines were developed, which included recommendations for personnel, equipment, vehicle, communication methods, and care protocols. Eight of nine hospitals endorsed the guidelines. A follow-up survey revealed practice changes for standing orders/protocols, communication, and equipment. CONCLUSION: Regionwide practice changes can be successfully implemented. Guidelines may be helpful for other regions using primarily one-way maternal transports.

Emergency Medical Service Communication Systems↗