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Biomedical subjects

B Martin

Publications and source records attributed to B Martin.

At least 451 records · Page 25Linked to original sources
PubMed1978

A film projecting system as a diagnostic and training technique for eye movements of cerebral palsied children.

Films are presented for tracking on a translucent screen after reflection from a galvanometer driven mirror. A wave function generator produces picture displacements of amplitude and velocity capable of stimulating selectively (or simultaneously) the saccadic and smooth pursuit systems. This audiovisual signal permits prolonged eye movement recording and training sessions because of increased motivation and alertness. Optokinetic and vestibulo-ocular reflexes can also be tested. An infra-red photoelectric device monitors the horizontal component of eye movement. Records provide the necessary information for syndrome definition and training progress evaluation. Preliminary results show the technique to be perfectly suitable for the diagnosis of functional disorders and sensory-motor training of the cerebral palsied child's oculomotor system.

Attention↗
PubMed1978

Influence of diet on leg uptake of glucose during heavy exercise.

Four young men each performed three treadmill walks to exhaustion at 70% of their respective O2 uptake maxima. Each walk followed 3 days consumption of either a normal mixed (M), high fat and protein (F-P), or high carbohydrate (CHO) diet. The fractional use of carbohydrates for energy during the initial 1/2-hr of work was significantly reduced following the F-P diet as compared with the M or CHO diets (P less than 0.005), averaging 38.2% (F-P), 69.9% (M), and 71.9 (CHO). Carbohydrates energy production was negatively correlated with blood levels of both free fatty acids ( r = -0.62, P less than 0.05) and beta-OH-butyrate (r = - 0.79, P less than 0.005). Work time to exhaustion was closely correlated with the fractional usage of carbohydrates for energy (r = 0.86, P less than 0.001). The femoral arteriovenous blood glucose difference was directly related to the pre-work dietary carbohydrate fraction, with the 30-min work means 0.25 mM (F-P), 0.34 mM (M), and 0.52 mM (CHO). Estimation of leg arteriovenous O2 difference indicated that leg uptake of blood-borne glucose provided approximately 23 +/- 10% (F-P), 30 +/- 8% (M), and 46 +/- 13% (CHO) of the legs' aerobic substrate during the first 30 min of work. These results provide further evidence for the shift from noncarbohydrate to carbohydrate energy sources during exercise as the carbohydrate fraction of the diet is elevated.

Adult↗
PubMed1978

7,N,N-Trimethyltryptamine: a selective inhibitor of synaptosomal serotonin uptake.

7,N,N-Trimethyltryptamine (TMT) was synthesized and evaluated as an inhibitor of synaptosomal biogenic amine uptake in rat forebrain homogenates. In addition to inhibiting 3H-serotonin uptake (IC50 = 0.4 micrometer), TMT appears to be quite selective and is much less potent in blocking either 3H-norepinephrine or 3H-dopamine uptake (IC50 = 180 micrometer and 61 micrometer, respectively).

Animals↗
PubMed1977

Cataract surgery in eyes predisposed to retinal detachment.

Modifications in cataract surgery technique in patients who have had previous retinal detachment surgery is considered in the following groups: previous "phakic" retinal detachment, in the same eye, in the fellow eye, and previous aphakic retinal detachment in the fellow eye. Prophylactic treatment prior to cataract surgery in these groups is also discussed as well as the prophylaxis of predisposing lesions prior to lens extraction. Finally, the place of cataract surgery in the presence of a retinal detachment is reviewed.

Anesthesia, Inhalation↗
PubMed1977

Hypopigmented sarcoidosis in the negro. Report of eight cases with ultrastructural observations.

The dermatological aspects of eight negro patients with hypopigmented sarcoid lesions are described. Light microscope histochemical studies in patients did not reveal the mechanism of the hypopigmentation. However, electronmicroscopy of lesions in two patients showed melanocytes undergoing changes resembling those observed in other acquired hypopigmentary conditions. It is suggested that in these disorders, melanocytes react morphologically in a similar non-specific manner, whatever the prime pathological process.

Adult↗
PubMed1976

Control, monitor and alarm system for clinical application of a membrane oxygenator.

Membrane oxygenators, now commercially available, are undergoing clinical trials as long-term (days) respiratory support devices for patients in potentially reversible respiratory failure. However, these devices must be used in an integrated system of controls, monitors and alarms if they are to be reliable and easy to operate in the clinical environment. This paper describes such a system. The tubing circuits for blood and for oxygen are described first. Next, details of the blood pump controls are presented. The system features servo control of pump speed to match blood inflow, and deactivation of the pump in the case of excessive output pressure. Gas circuit controls are described which allow the independent adjustment of both oxygen flow through the gas phase of the membrane lung and oxygen pressure developed at the inlet gas port. Audible alarms are provided for low blood inflow to the system, excessive blood outflow pressure, changes in oxygen flow and failure of the electric power supply to the system. In addition to pressure and flow monitors in the blood and gas circuits, blood oxygen saturation is continuously monitored at both input and output of the system. The membrane oxygenator system has proved to be reliable and easy to operate in both animal and human long-term perfusions.

Animals↗
PubMed1976

Dioxygenated metabolites of cannabidiol formed by rat liver.

The metabolism of cannabidiol (CBD) was studied in vitro using a 10 000 g supernatant from rat liver. After removal of unchanged CBD and its monohydroxylated metabolites, a polar fraction remained from which ten dioxygenated metabolites were isolated. Mass spectrometry and nuclear magnetic resonance spectroscopy were used to identify the following metabolites: 6,7-dihydroxy-CBD, 1 inch,7-dihydroxy-CBD, 3 inch,7-dihydroxy-CBD, 4 inch,7-dihydroxy-CBD, 5 inch,7-dihydroxy-CBD, 2 inch,6-dihydroxy-CBD, 3 inch,6beta-dihydroxy-CBD, 4 inch, 6beta-dihydroxy-CBD (tentative), 3 inch-hydroxy-6-oxo-CBD, and 4 inch-hydroxy-6-oxo-CBD. The abundance of isolated dihydroxy metabolites reflected the quantity of monohydroxy metabolites that was previously found. In both series, 7-hydroxylation occurred to the greatest extent. Side chain hydroxylation occurred predominantly at C-4 inch and to a lesser degree at C-3 inch. Trace amounts of metabolites were hydroxylated at C-1 inch,-2 inch, or 5 inch.

Animals↗
PubMed1976

Identification of monohydroxylated metabolites of cannabidiol formed by rat liver.

Cannabidiol (CBD) was metabolized in vitro by rat liver enzymes. Unchanged CBD and eight monohydroxylated metabolites were isolated and positively identified. As previously reported, 7-hydroxy-CBD was the major metabolite. The second most abundant metabolite was 6alpha-hydroxy-CBD; whereas only a trace amount of 6beta-hydroxy-CBD was found. In addition hydroxylation occurred in all positions of the pentyl side chain, 4 inches-hydroxy-CBD being most abundant. 3 inches-Hydroxy-CBD was formed in half of the yield of 4 inches-hydroxy-CBD, while 1 inches-, 2 inches-, 5 inches-hydroxy-CBD were each formed in approximately one fourth of the yield of 4 inches-hydroxy-CBD.

Animals↗
PubMed1976

A comparison of membrane fracture faces of fixed and unfixed glycerinated tissue.

Fixed (glutaraldehyde, 3%) and unfixed specimens of rat buccal epithelium, striated muscle, and liver, were cryoprotected with glycerol, freeze-fractured, and replicated without sublimation. A comparison of fracture faces of general plasma membranes, nuclear membranes, mitochondrial membranes, and membranes of rough endoplasmic reticulum revealed no significant differences as between fixed and unfixed material. Apart from some membranes of liver endoplasmic reticulum, there was no evidence of aggregation or redistribution of intramembranous particles in the unfixed material. The results demonstrate that chemical prefixation of tissues for freeze-fracture is not always necessary, or even desirable, and that glycerol may not be as deeply or directly implicated in particle aggregation as previously thought. Fixation with glutaraldehyde alters the cleaving behaviour of plasma membrane at desmosomes and tight junctions, but not at gap junctions.

Animals↗