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Biomedical subjects

J L Graham

Publications and source records attributed to J L Graham.

At least 19 recordsLinked to original sources
PubMed2004

MTBE oxidation byproducts from the treatment of surface waters by ozonation and UV-ozonation.

In recent years, there has been considerable concern over the release of methyl tert-butyl ether (MTBE), a gasoline additive, into the aquifers used as potable water sources. MTBE readily dissolves in water and has entered the environment via gasoline spills and leaking storage tanks. In this paper, we investigate ozonation and UV-ozonation for treatment of MTBE in contaminated drinking water sources. We report the test protocol and results of using solid-phase microextraction (SPME) to determine the level of MTBE and its oxidation byproducts in samples drawn from laboratory-scale ozone and UV-ozone reactors being evaluated at a US EPA research facility. Analysis of a prepared MTBE standard indicated a detection limit on the order of 0.1 microgl(-1) with a repeatability of +/-0.4%. Results show that the overall rate of removal of MTBE via UV-ozonation in a relatively turbid surface water (15 ntu) is twice that of ozonation alone. In addition, GC-MS analysis of decomposition products showed that tert-butyl formate (TBF), methyl acetate, butene, acetone, and acetaldehyde were produced by both processes. TBF and butene reach similar maximum yields from the two processes, but are more efficiently degraded by UV-ozonation treatment. This indicates that these treatment processes also degrade these byproducts. In contrast, the remaining byproducts (methyl acetate, acetone, and acetaldehyde) are formed at similar levels during treatment, but are not degraded once formed. These byproducts may be resistant to hydrogen abstraction by hydroxyl radical.

Chromatography, High Pressure Liquid↗
PubMed2001

Social support and avoidant coping: correlates of depressed mood during pregnancy in minority women.

INTRODUCTION: The purpose of this study was to evaluate several psychosocial correlates of depressed mood during pregnancy. The psychosocial factors examined included background characteristics (socioeconomic status, planning of pregnancy), perceived social support, and coping styles. METHODS: One hundred fifty pregnant lower income, minority women were recruited from an obstetrics clinic at an urban hospital. Patients completed a battery of psychosocial measures including measures of social support, coping style, and depressed mood. RESULTS: Perceived social support and an avoidant coping style were the most salient psychosocial correlates of depressed mood during pregnancy, accounting for 34% of the variance in the model. More specifically, women who reported less social support satisfaction experienced greater avoidant coping strategies, which was then associated with higher levels of depressed mood. CONCLUSIONS: This study suggests that women who perceive less social support satisfaction utilize more avoidant coping strategies and experience greater depression mood. Thus, although these associations are not indicative of a causal relationship, results raise the possibility that women at-risk for depressed mood during pregnancy can be identified by assessing perceived social support and coping styles. Future prospective studies are needed to test the causal relationships among these variables. Clinical interventions to target these psychosocial factors during pregnancy are discussed.

Adaptation, Psychological↗
PubMed1997

The vital dye Evans blue mimics limbic seizures induced by kainate or pilocarpine.

Evans blue dye, given i.c.v. in rats in a dose of 208 nmol, causes electrical and behavioural seizures which resemble those induced by the glutamate analogue, kainate, or by electrical kindling of the amygdala. Chicago sky blue, 201 nmol i.c.v., produces similar seizures. The principal elements of the seizures are wet-rat-shakes, facial and forelimb clonus, rearing and spike-and-waves in the EEG. A non-NMDA receptor antagonist, GYKI 52466 and a benzodiazepine, diazepam, significantly delay the onset to the occurrence of the first forelimb clonus. The cholinergic antagonist, scopolamine, significantly reduces the delay to onset of first facial clonus. The competitive NMDA receptor antagonist, D-CPPene, the non-specific dopamine antagonist, haloperidol, and the purinergic agonist, 2-chloroadenosine, have no effect on the measured parameters. During the induction of seizures by Evans blue, the average extracellular glutamate concentration in hippocampus or cortex does not increase statistically significantly in comparison to pre-seizure values. Histological examination of limbic areas indicates that the moderate to severe Evans blue-induced cell damage is similar to that seen after limbic seizures induced by pilocarpine and in the hippocampus is partially preventable by D-CPPene but not by diazepam or GYKI 52466. It is proposed that Evans blue-induced seizures may be useful as a new model for studying the mechanisms of intractable epilepsy of the complex partial seizure type.

Animals↗
PubMed1995

Intermittent pneumatic compression effect on eccentric exercise-induced swelling, stiffness, and strength loss.

OBJECTIVE: The purpose was to determine if intermittent pneumatic compression (IPC) affects muscle swelling, stiffness, and strength loss resulting from eccentric exercise-induced injury of the elbow flexors. We hypothesized that the compression would decrease swelling and stiffness. DESIGN: Repeated measures design with a before-after trial comparison within each day. SETTING: Conducted at a university Somatic Dysfunction Laboratory. SUBJECTS: Twenty-two college women students were studied. They had not been lifting weights or otherwise participating in regular arm exercise for the 6 months before the study. They had no history of upper extremity injury or cardiovascular disease. INTERVENTIONS: Subjects performed one bout of eccentric exercise at a high load to induce elbow flexor muscle injury. Uniform IPC was applied on the day of exercise and daily for 5 days at 60mmHg, 40 seconds inflation, 20 deflation for 20 minutes. MAIN OUTCOME MEASURES: Measurements of arm circumference, stiffness, and isometric strength were recorded before exercise, then before and after IPC for 5 days after exercise. Passive muscle stiffness was measured on a device that extends the elbow stepwise and records the torque required to hold the forearm at each elbow angle. RESULTS: Circumference and stiffness increased and strength decreased during the 5 days post-exercise (p < .05). IPC significantly decreased circumference and stiffness most notably on days 2 and 3 after exercise (p < .05). The strength loss was not affected by IPC. CONCLUSION: IPC is effective in temporarily decreasing the swelling and stiffness after exercise-induced muscle injury.

Adult↗
PubMed1994

Effect of the non-NMDA receptor antagonist GYKI 52466 on the microdialysate and tissue concentrations of amino acids following transient forebrain ischaemia.

The effect of the non-N-methyl-D-aspartate (non-NMDA) receptor antagonist 1-(4-aminophenyl)-4-methyl-7,8-methylenedioxy-5H-2,3-benzodiazepine hydrochloride (GYKI 52466) on ischaemia-induced changes in the microdialysate and tissue concentrations of glutamate, aspartate, and gamma-aminobutyric acid (GABA) was studied in rats. Twenty minutes of four-vessel occlusion resulted in a transient increase in microdialysate levels of glutamate, aspartate, and GABA in striatum, cortex, and hippocampus. Administration of GYKI 52466 (10 mg/kg bolus + 10 mg/kg/60 min intravenously starting 20 min before onset of ischaemia) inhibited ischaemia-induced increases in microdialysate glutamate and GABA in striatum without affecting the increases in hippocampus or cortex. Twenty minutes of four-vessel occlusion resulted in immediate small decreases and larger delayed (72 h) decreases in tissue levels of glutamate and aspartate. Transient increases in tissue levels of GABA were shown in all three structures at the end of the ischaemic period. At 72 h, after the ischaemic period, significantly reduced GABA levels were observed in striatum and hippocampus. GYKI 52466, given under identical conditions as above, augmented the ischaemia-induced decrease in striatal tissue levels of glutamate and aspartate, without significantly affecting the decreases in hippocampus and cortex. Twenty minutes of ischaemia resulted in a large increase in microdialysate dopamine in striatum. GYKI 52466 failed to inhibit this increase. Kainic acid (500 microM infused through the probe for 20 min) caused increases in microdialysate glutamate and aspartate in the striatum. GYKI 52466 (10 mg/kg bolus + 10 mg/kg/60 min) completely inhibited the kainic acid-induced glutamate release. In conclusion, the action of the non-NMDA antagonist, GYKI 52466, in the striatum is different from that in the cortex and hippocampus. The inhibition by GYKI 52466 of ischaemia-induced and kainate-induced increases in microdialysate glutamate concentration in the striatum may be related to the neuroprotection provided by GYKI 52466 in this region.

Amino Acids↗
PubMed1988

Nalbuphine and pentazocine in an opioid-benzodiazepine sedative technique: a double-blind comparison.

Sedation by a combination of an opioid drug such as pentazocine with a benzodiazepine is commonly used for minor surgical and investigative procedures. Nalbuphine is a newer drug which, like pentazocine, is an opioid agonist-antagonist. Its actions are similar, but it has theoretical advantages in its profile of cardiovascular side effects. Nalbuphine or pentazocine in combination with diazepam were compared as components of a sedative technique for invasive radiology. The doses used were in the ratio of 2.5:1--ie nalbuphine 0.2 mg kg-1 and pentazocine 0.5 mg kg-1. Both regimens gave satisfactory results, and no difference could be detected between them in terms of sedation, analgesic efficacy, cardiovascular or respiratory changes, or recovery. Nalbuphine provides a safe and effective alternative to pentazocine in this situation. The study confirmed the need for caution because of the respiratory depressant effects of both drugs.

Aged↗
PubMed1982

Receptor--ion channel interactions in Torpedo electric organ: influence of thiol group modification.

The influence of sulfhydryl and disulfide reagents on nicotinic cholinergic receptors and ion channels and their interactions was investigated using specific probes for receptor and channel binding sites in electric organs from Torpedo californica. N-ethylmaleimide, a sulfhydryl alkylating agent, did not alter receptor or ion channel binding, or receptor-mediated ion channel binding activation or desensitization. Alteration of receptor--ion channel coupling produced by treatment with an organic sulfhydryl, dithiothreitol, could be accounted for on the basis of decreases in receptor affinity for agonists. These changes were reversed by exposure to an oxidizing agent. Following reduction by dithiothreitol, N-ethylmaleimide treatment produced large decreases in the extent and affinity of both receptor and channel binding. No evidence for a direct role of thiol groups in ion channel function was obtained.

Animals↗
PubMed1982

The respiratory depression of epidural morphine. Time course and effect of posture.

In order to investigate the time course of the late respiratory depression which has been reported following epidural opiates, the response to CO2 was measured in 11 patients. Epidural morphine 2 mg was given 1 hour after operation under bupivacaine epidural anaesthesia, and the patients nursed supine. The results show a consistent pattern of respiratory depression commencing at approximately 48 hours, and continuing until 18-24 hours after administration of morphine. A similar group of 10 patients nursed in a sitting position did not show the same degree of depression, and a modifying effect of posture on the development of central effects is suggested.

Carbon Dioxide↗
PubMed1980

Health education: focusing on the video show.

In his second article on patient education Dr J. L. Graham, chief administrative medical officer, Forth Valley Health Board, describes how six short videotapes are being produced and evaluated in a research project. The research consists of four main areas: preliminary work, exploratory work, production of the videotape and, lastly, evaluation of its effectiveness.

Evaluation Studies as Topic↗
PubMed1980

Health education: message and medium.

During 1979, 1980 and 1981, the Scottish Health Education Unit of the Scottish Health Service Common Services Agency is funding a research project involving the production and evaluation of six video recorded health education programmes. The project is being undertaken by the Department of Community Medicine of the Forth Valley Health Board and the Department of Continuing Medicine, Stirling University. In the first of two articles, Dr J.L. Graham, Chief Administrative Medical Officer, Forth Valley Health Board, and Chairman of the project's steering committee, describes the benefits of this approach.

Audiovisual Aids↗
PubMed1980

Postoperative pain relief using epidural morphine.

In postoperative prostatectomy patients, morphine 2 mg in 10 ml 0.9% saline was given epidurally for pain relief and its effectiveness compared with bupivacaine. The duration of analgesia with morphine was approximately double that with bupivacaine. Significant hypotension occurred in approximately 5% of the patients receiving bupivacaine, but was not seen following morphine. These seem to be important advantages in the use of morphine by this route.

Anesthesia, Epidural↗
PubMed1977

Topical clotrimazole in tinea pedis.

Clotrimazole is a new antifungal agent which is effective topically in dermatophytosis, cutaneous candidiasis, and tinea vesicolor. The authors performed a controlled double-blind clinical trial comparing topical clotrimazole with its vehicle in the treatment of 66 patients with dermatophytic infections of the skin of the feet. Clotrimazole proved to be effective in the treatment of tinea pedis of both the interdigital and the plantar hyperkeratotic types.

Administration, Topical↗