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Biomedical subjects

C Singleton

Publications and source records attributed to C Singleton.

18 recordsLinked to original sources
PubMed1999

Clinical use of the Odstock dropped foot stimulator: its effect on the speed and effort of walking.

OBJECTIVE: To assess the clinical effectiveness of the Odstock dropped foot stimulator by analysis of its effect on physiological cost index (PCI) and speed of walking. This functional electrical stimulation (FES) device stimulates the common peroneal nerve during the swing phase of gait. DESIGN: A retrospective study of patients who had used the device for 4 1/2 months. SUBJECTS: One hundred fifty-one patients with a dropped foot resulting from an upper motor neuron lesion. SETTING: A medical physics and biomedical engineering department of a district general hospital specializing in the clinical application of FES and a neurophysiotherapy department at a separate hospital. MAIN OUTCOME MEASURES: Changes in walking speed and effort of walking, as measured by PCI over a 10-meter course. RESULTS: There was a 92.7% compliance with treatment. Stroke patients showed a mean increase in walking speed of 27% (p<.01) and reduction in PCI of 31% (p<.01) with stimulation, and changes of 14% (p<.01) and 19% (p<.01), respectively, while not using the stimulator. Multiple sclerosis patients gained similar orthotic benefit but no "carry-over." CONCLUSIONS: The measured differences in walking with and without stimulation were statistically significant in the stroke and multiple sclerosis groups. In this study use of the stimulator improved walking. Those with stroke demonstrated a short-term "carry-over" effect.

Adult↗
PubMed1999

Clinical audit of 5 years provision of the Odstock dropped foot stimulator.

The Odstock dropped foot stimulator (ODFS) is a foot switch controlled single channel neuromuscular stimulator for correction of dropped foot. Following a randomized controlled trial, the ODFS was recommended for use in the United Kingdom's National Health Service and a clinical service established. The patient performance was assessed by measurement of walking speed over 10 m, physiological cost index (PCI), and by questionnaire. After 4.5 months stroke patients (n = 111) showed a mean increase in walking speed of 27% and reduction in PCI of 31% with stimulation and changes of 14% and 19%, respectively, unassisted. Multiple sclerosis patients (n = 21) gained similar orthotic benefit but no carry over. The principal reason cited for using the equipment was that it reduced the effort of walking. The principal reasons identified for discontinuing were an improvement in mobility, electrode positioning difficulties, and deteriorating mobility. A comprehensive clinical follow-up service is essential to achieve the maximum continuing benefit from FES based orthosis.

Cerebrovascular Disorders↗
PubMed1997

Age-related trends (1986-1993) in the use of thrombolytic agents in patients with acute myocardial infarction. The Worcester Heart Attack Study.

OBJECTIVE: To examine age-related differences and temporal trends in the use of thrombolytic therapy in a community-wide study of patients hospitalized with acute myocardial infarction (AMI) between 1986 and 1993. METHODS: All hospitals in the Worcester, Mass, metropolitan area (1990 census population, 4370000) were included. A total of 3824 patients with validated AMI categorized according to age comprised the study sample: younger than 55 years (n = 577), 55 to 64 years (n = 758), 65 to 74 years (n = 1143), and 75 years or older (n = 1346). RESULTS: Use of thrombolytic therapy increased during the period under study in all patients hospitalized with AMI (9% in 1986; 26% in 1993). In 1986, the majority of treated patients received streptokinase; while increases over time in the use of tissue-type plasminogen activator were noted, streptokinase remained the thrombolytic agent of choice in 1993. Marked age-related trends in the use of thrombolytic therapy were observed, with the most striking increases in the use of thrombolytic therapy over time seen in those aged 65 years or older. Between 1986 and 1993 the relative increases in the use of thrombolytic therapy were observed in the following age groups: younger than 55 years (106%), 55 to 64 years (85%), 65 to 74 years (694%), and 75 years or older (571%). Despite these encouraging trends in the use of thrombolytic therapy in older patients, after controlling for a variety of potential confounding variables elderly patients were significantly less likely to receive thrombolytic therapy during hospitalization for AMI. Compared with patients aged 75 years or older, patients younger than 55 years were 6.4 times (95% confidence interval [CI], 4.8-8.5), patients aged 55 to 64 years were 4.9 times (95% CI, 3.8-6.4), and patients aged 65 to 74 years were 3.0 times (95% CI, 2.3-3.9) significantly more likely to receive thrombolytic therapy. These differences were in part related to the proportion of patients with myocardial infarction satisfying eligibility criteria for the receipt of thrombolytic therapy; patients aged 75 years or older were significantly less likely to meet these criteria (19%) than were those younger than 55 years (49%), those aged 55 to 64 years (38%), and those aged 65 to 74 years (28%). CONCLUSIONS: The present results show that while there have been substantial increases over time in the use of thrombolytic therapy in patients with AMI, most particularly in older individuals, the elderly remain appreciably less likely to receive these agents during hospitalization for AMI. These differences may be due to the smaller percentage of elderly patients satisfying criteria for the use of these agents compared with younger patients with coronary heart disease, as well as to a reluctance by physicians to use these agents in older patients. Continued monitoring of these trends remains important for examining changes in physicians' practice patterns regarding the use of thrombolytic therapy in this vulnerable population.

Age Factors↗
PubMed1996

Wild-type strains of Dictyostelium discoideum can be transformed using a novel selection cassette driven by the promoter of the ribosomal V18 gene.

Almost all methods for transformation of the social ameba Dictyostelium discoideum rely on axenic growth, that is, growth in a synthetic medium, for at least part of the procedure. Axenic growth requires several mutations. Here we describe a procedure that can be used to transform wild-type strains which are able to grow only on the natural food source, bacteria. The method relies on a new selection cassette driven by the V18 promoter, a promoter that we show is substantially more active during growth on bacteria than the actin-6 promoter, which is widely used for axenic transformation. The procedure gives transformation frequencies of about 10(-5) with both strains Ax2 (capable of axenic growth) and NC4 (capable of growth only on bacteria). Using this vector, we have obtained NC4 strains carrying several beta-galactosidase reporter cassettes. Our vector can also be used in axenic transformations.

Actins↗
PubMed1983

Glycolipid crypticity in membranes--not a simple shielding effect of macromolecules.

The potential of membrane-bound macromolecules for shielding glycolipids from involvement in specific binding events was considered in model membranes. Serum albumin and several Dextrans were covalently derivatized with oleic acid so that they adsorbed irreversibly to lipid bilayers. This provided a means of generating bilayer membranes with a considerable layer of attached material. Gangliosides dispersed in such membranes were subjected to attack by the enzyme, neuraminidase, in order to assess their "accessibility'. We were surprised to find that we could not demonstrate any significant reduction in ganglioside hydrolysis in phosphatidylcholine bilayers bearing extensive surface coats of protein or polysaccharide. We conclude that non-specific, physical shielding by macromolecules is an unlikely source of the often-observed "crypticity' of glycolipids at the cell surface. Consistent with this interpretation was a relative lack of headgroup motional restriction seen for spin-labelled ganglioside headgroups in the same bilayers and in cell membranes.

Electron Spin Resonance Spectroscopy↗
PubMed1981

Circadian variation in the head twitch response produced by 5-methoxy-N1,N1-dimethyltryptamine and p-chloroamphetamine in the mouse.

Circadian fluctuations were measured in the head twitch response produced by 5-methoxy-N1,N1-dimethyltryptamine (5-MeODMT) and p-chloroamphetamine (PCA) in male BK. TO mice. The effects of depleting brain 5-hydroxytryptamine (5-HT) with p-chlorophenylalanine (PCPA) on the 5-MeODMT in the mouse were also studied. Changes in brain 5-HT and 5-hydroxyindoleacetic (5-HIAA) were concomitantly determined. PCPA (400 mg/kg IP twice on consecutive days) significantly increased the number of head twitches induced by 5-MeODMT (5 mg/kg IV) on days 3 and 5 after the initial injection of PCPA when 5-HT and 5-HIAA were also significantly reduced. On day 12, there was no significant difference in the number of head twitches between mice administered PCPA and those given saline, and 5-HT and 5-HIAA levels were nearly back to normal. PCPA, using the same dose schedule, significantly reduced the number of head twitches induced by PCA when PCA was administered 24 h after the second injection of PCPA (day 3. Mice maintained on a 12-h light-dark cycle showed a maximum response to the direct 5-HT receptor agonist 5-MeODMT (5 mg/kg IV) towards the end of the dark period, when the 5-HT level was at its lowest. p-Chloroamphetamine, which causes release of 5-HT from pre-synaptic neurones, produced a peak head twitch response in the middle of the light period when 5-HT and 5-HIAA levels were maximal, while the response towards the end of the dark period was significantly less than that at other times tested. It is concluded that 5-HT receptor response shows a circadian rhythm related to both pre-synaptic availability of 5-HT and post-synaptic receptor sensitivity.

Amphetamines↗
PubMedDate not supplied

The reading comprehension abilities of dyslexic students in higher education.

The reading comprehension abilities of a group of dyslexic university students were compared with those of non-dyslexic university students. A 655-word passage, followed by literal and inferential questions, was used to measure reading comprehension. The text was designed to be syntactically complex, yet place relatively modest demands on decoding skills. Although dyslexic students performed at a similar level to the non-dyslexic students on the literal questions, their performance on the inferential questions was poorer. An index of the participants' ability to make inferences was calculated by subtracting the inferential question score from the literal question score. The groups differed significantly on this measure, indicating that the dyslexic students were specifically impaired in constructing inferences when processing complex text. It was concluded that dyslexic students in higher education have reading comprehension difficulties that cannot be accounted for by an inability to decode individual words in the text. The possible contribution that poor lexical automaticity and an impaired working memory make to this impairment is discussed. The implications for the assessment and support of dyslexic students are considered.

Adolescent↗
PubMedDate not supplied

Drugs test cop-out?

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Career Choice↗