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Biomedical subjects

S Murphy

Publications and source records attributed to S Murphy.

At least 559 records · Page 31Linked to original sources
PubMed1969

The metabolism of hexachlorocyclohexanes and pentachlorocyclohexenes in flies and grass grubs.

1. gamma-Hexachlorocyclohexane, gamma-pentachlorocyclohexene and delta-pentachlorocyclohexene were converted by houseflies and grass grubs into metabolites that had chromatographic properties identical with those of S-2,4-dichlorophenylglutathione. 2. The metabolism of gamma-hexachlorocyclohexane and the pentachlorocyclohexene isomers was negligible in newly emerged blowflies, but increased over the next 10 days. 3. The metabolism of both gamma-hexachlorocyclohexane and the pentachlorocyclohexene isomers was inhibited by simultaneous dosage with tetrabromophenolphthalein ethyl ester or Bromophenol Blue in both grass grubs and flies, but only the metabolism of pentachlorocyclohexenes in blowflies was stopped by simultaneous dosage with bis-(N-dimethylaminophenyl)methane. NN-Di-n-butyl-p-chlorobenzenesulphonamide had no effect on the metabolism of pentachlorocyclohexenes by blowflies. 4. The use of these inhibitors and colorimetric assays leads to the conclusion that a pentachlorocyclohexene is not a major intermediary metabolite of gamma-hexachlorocyclohexane in these insects.

Animals↗
PubMedDate not supplied

A comparison of the functional durability of the AMS 800 artificial urinary sphincter between cases with and without an underlying neurogenic aetiology.

AIM: To compare the efficacy and functional durability of the American Medical Systems 800 (AMS 800) artificial urinary sphincter (AUS) device for patients with neurogenic and non-neurogenic incontinence. METHODS: From 1985 to 2000, 38 patients underwent implantation of an AMS 800 AUS at our institution. Thirty of these patients had complete records and follow-up data available. The mean follow-up for these two groups of patients was six years. Seventeen devices (57%) were implanted for non-neurogenic indications including incontinence after prostatectomy or hysterectomy. Thirteen devices (43%) were implanted for neurogenic conditions including spina bifida, spinal cord injury or severe pelvic trauma. The primary end point measured was continence. Secondary end points included mechanical and non-mechanical device failure, re-operation and complication rates between the two groups. RESULTS: In the neurogenic group, only two patients (15%) have their original device in situ without revisions. Only three patients (23%) in this group are entirely dry. In contrast, seven patients (41%) in the non-neurogenic group are completely dry with their original device in situ. A further four (23%) are entirely dry after device revision or replacement surgery. The rates of mechanical failure were not statistically different between the two groups. The rate of non-mechanical failure (NMF) was statistically greater in the neurogenic group in comparison to that in the non-neurogenic group (p < 0.05). CONCLUSIONS: Insertion of an AMS 800 artificial sphincter remains a durable means of regaining urinary continence. Patients who are incontinent as a result of an underlying neurological deficit should be counselled that they might have a higher risk of non-mechanical device failure, requirement for re-operation and that their overall long-term continence rates may be poor.

Adolescent↗
PubMedDate not supplied

How well is peripheral neuropathy investigated? An audit from a regional neurophysiology department.

BACKGROUND: Peripheral neuropathy (PN) is common and increases with age. AIM: To assess how patients with confirmed peripheral neuropathy on nerve conduction studies (NCS) were investigated and to determine whether there was any difference in investigation based on patient age or referral source. DESIGN: Retrospective audit. METHODS: All EMG/NCS reports from a one-year period were analysed. The computer laboratory system was used to determine which blood tests had been performed on those patients with confirmed peripheral neuropathy on NCS. RESULTS: Over 50% of patients referred from within the hospital did not have a basic blood screen to search for the aetiology. There was no significant difference in investigation practise based on patient age or referral source. CONCLUSION: Our results highlight the lack of systematic investigation in a university teaching hospital. As a result of this audit, a protocol has been prepared and is distributed with NCS/EMG reports.

Age Factors↗
PubMedDate not supplied

MSH affects regional perfusion of the brain.

With the single exception of the occipital cortex, the flow of blood to most regions of the brains of conscious, unrestrained rats was reduced within 10 min after intravenous administration of alphaMSH. Though these effects were transitory for most regions of the brain, perfusion of cerebellum, pons and medulla, hippocampus, and parietal cortex was still significantly low by 20 min. Assuming that flow changes reflect functional changes, these early responses to alphaMSH suggest an explanation for the effects of this hormone in which visual learning is improved.

Animals↗
PubMedDate not supplied

Relationships between nitric oxide synthase, vasoactive intestinal peptide and substance P immunoreactivities in neurons of the amphibian intestine.

Nitric oxide synthase (NOS)-containing neurons (localized using NADPH diaphorase histochemistry or NOS immunoreactivity) and vasoactive intestinal peptide-immunoreactive (VIP-IR) neurons were found in the myenteric plexus of the gastrointestinal tract of the amphibian, Bufo marinus. Only limited co-localization of the two substances was observed in nerve cell bodies, about 11% of the NOS-containing neurons were also labelled by VIP-IR and about 37% of VIP-IR nerve cell bodies contained NOS. The relationship between VIP, NOS and SP-IR in nerve fibres in the circular muscle was examined. There was partial co-localization of VIP and NOS, but no co-localization of NOS or VIP with substance P. Of fibres that were immunoreactive for VIP or NOS, fewer than 10% contained VIP alone.

Amino Acid Oxidoreductases↗
PubMedDate not supplied

Projections of nitric oxide synthase- and peptide-containing neurons in the small and large intestines of the toad (Bufo marinus).

The projections of galanin (GAL)- and vasoactive intestinal peptide (VIP)-immunoreactive (IR) and nitric oxide synthase (NOS)-containing neurons in the small and large intestines of the amphibian Bufo marinus were investigated by their reactions to surgical interruption (myotomy). In the small intestine, myotomy caused accumulation of GAL- and VIP-IR and of NADPH diaphorase reaction product (revealing NOS) in cut axons on the oral side of the operation site. On the anal side there was loss of GAL-IR axons from the circular muscle and myenteric plexus and long, anally directed processes could be traced from GAL-IR nerve cell bodies. There was no significant loss of VIP-IR or NADPH diaphorase from nerve fibres in the myenteric plexus or circular muscle layer, although anally-directed axons could be traced from nerve cell bodies on the anal side of the operation sites. In the large intestine, myotomy caused accumulation of VIP-IR and of NADPH diaphorase reaction product in cut axons on the oral side of the operation site. Anal to the cut, although there was no significant loss of these fibres from the muscle or myenteric plexus, anally directed axons could be traced from nerve cell bodies. GAL-IR fibres in the large intestine are of two types: a few contain GAL-IR alone and are thought to arise from enteric neurons; many contain both GAL- and SOM-IR and are thought to arise from nerve cell bodies in the hindgut. Myotomy caused an accumulation of GAL/SOM-IR material in fibres on the anal side of the cut and a substantial decrease in the number of fibres on the oral side. There was no detectable effect of myotomy on the GAL-IR fibres, although an abnormally high density of GAL-IR nerve cell bodies was found oral to the cut. These results indicate that VIP-IR and NOS-containing enteric neurons project in an oral to anal direction in the toad small and large intestines. Some of the neurons have short anal projections to the circular muscle. GAL-IR enteric neurons have similar projections in the small intestine, but their projections could not be determined in the large intestine. GAL/SOM-IR axons in the large intestine project from anal to oral. Myotomy in the large intestine appears to induce an increased or de novo expression of GAL-IR in enteric neurons oral to the cut.

Amino Acid Oxidoreductases↗
PubMedDate not supplied

An analog of ACTH/MSH (4-9), ORG-2766, reduces cerebral uptake of morphine.

The uptake of morphine was significantly reduced in most regions of the brains of conscious, unrestrained rats within 10 minutes after treatment with an analog of ACTH/MSH (4-9), ORG-2766. The effect was most obvious in regions with significant densities of enkephalin receptors, namely basal ganglia, hippocampus and cortex. The results explain, in part, how some fragments and analogs of ACTH/MSH may antagonize behavioral actions of morphine, even though some of these peptides lack significant opiate receptor binding properties. We believe that this effect of ORG-2766 is related to an action on the permeability characteristics of the brain microvasculature. The underlying mechanism is unknown.

Adrenocorticotropic Hormone↗
PubMedDate not supplied

Cerebrovascular permeability and cognition in the aging rat.

Regional cerebrovascular permeability-capillary surface area products (rPS) and brain vascular space (BVS) were measured in aging, conscious, unrestrained Sprague-Dawley rats. Three groups of animals were examined: young-mature (6 months), middle-aged (12-14 months), and old (24-26 months) rats. Complex maze learning had been previously characterized in these same animals. Maze learning declined with age. Brain vascular space did not differ significantly with age in any brain region. However, small, but significant age-dependent decreases in rPS (25-33%) were observed. These decreases occurred mainly in the old animals in the basal ganglia and parietal cortex, and in the middle-aged and old rats in the olfactory bulbs. Significant and unexpected positive average correlations between brain permeability-capillary surface area products (PS) and learning errors occurred primarily in young rats and were attributable mainly to changes in 5 of 14 brain regions; hypothalamus, hippocampus, parietal cortex, septal area and superior colliculus. The higher correlations between maze learning errors and PS in young animals may indicate dynamic regulation of this cerebrovascular parameter which is lessened with aging. Average correlations between PS and cerebral blood flow also were determined and found to be generally small and not significant for most brain regions and age groups.

Aging↗
PubMedDate not supplied

An open randomized trial of artemether versus quinine in the treatment of cerebral malaria in African children.

We have compared the efficacy of artemether versus quinine as treatment for cerebral malaria in children in an open randomized clinical trial in Kenya. Children admitted to hospital with coma and Plasmodium falciparum parasitaemia were treated with either intramuscular artemether (3.2 mg/kg loading dose followed by 1.6 mg/kg daily) or intravenous quinine (20 mg/kg loading dose followed by 10 mg/kg every 8 h). Both drugs were well tolerated and no significant adverse effect was observed. Parasite clearance times (50% and 90%) were shorter in patients treated with artemether (median times [h], with interquartile ranges in brackets, were: 50%, 7.3 [4.2-12.4] vs. 15.5 [9-22]; 90%, 16.9 [13.2-25] vs. 28.5 [22-35]; P < 0.0001). The total mortality in 160 children with cerebral malaria was 16.25%, with no overall significant difference between the 2 treatment groups. In a subgroup of children with respiratory distress, mortality was higher in those treated with artemether (43.7% vs. 11.1%, P < 0.05). The frequency of neurological sequelae and clinical recovery times were similar in both treatment groups. We conclude that there would currently be no advantage in replacing quinine with artemether for the treatment of cerebral malaria in African children.

Antimalarials↗