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E Colon

Publications and source records attributed to E Colon.

6 recordsLinked to original sources

A method for delivery of precise doses of smoked cocaine-base to humans.

Despite increasing smoked cocaine-base use, there have been relatively few parametric studies in this area. The major reason for the limited number of studies is the lack of a simple procedure for the administration of precise doses of smoked cocaine-base to human volunteers. This paper describes a new method that allows for the delivery of precise doses of smoked cocaine-base. A complete description of the method and the precision of the administration procedure are presented. Furthermore, a study is described which was undertaken to determine: 1) the reproducibility of peak blood cocaine levels when the same dose of cocaine was given on two separate occasions; and 2) the dose-related effects on smoking topography, biochemical, physiological and subjective measures. Subjects (N = 5) were administered three doses of cocaine-base (10, 20 and 40 mg). Four subjects were given repeated doses of cocaine-base. Subjects were blind to the dose and in most cases randomly assigned to different doses. The results showed: 1) a significant correlation of peak whole blood cocaine concentrations among similar doses within subjects (r = .99); 2) no significant effects of dose on smoking topography; and 3) significant dose effects for whole blood cocaine concentrations, heart rate and systolic blood pressure.

Adult

Somatosensory evoked response in controlled A-alpha sensory fiber disease.

In contrast to the distal sensory response, the somatosensory evoked response (SSER) is detectable in patients with A-alpha sensory fiber diseases such as Friedreich's ataxia. In four patients with this disease a combined histological and electro-physiological investigation of sensory propagation was performed. The sural nerve was analyzed in terms of the various fiber diameters and the distal sensory and somatosensory evoked cortical responses recorded after sural and median nerve (finger) stimulation. A distinct evoked response could be detected with rather low amplitudes and retarded latency times, while in general no distal sensory response was found. The anatomical physiological consequences are discussed.

Adult

Changes in carotid flow velocity induced by lowering cerebrospinal fluid pressure in normal pressure hydrocephalus.

This is a report of changes in blood flow velocity in the carotid system induced by lumbar puncture in five patients who had clinical and neuroradiological signs of normal pressure hydrocephalus. After lowering cerebrospinal fluid pressure an increase of carotid flow velocity was found on Doppler hematotachography. These changes of carotid blood flow velocity could not be demonstrated in a control group of four patients with normal cerebrospinal fluid dynamics. This method is easy to perform, does not overtax the patient and seems to be indicated for the diagnosis of NPH. It is presented as a new, simple, reproducible aid to the diagnosis of NPH by Doppler hematotachography.

Adult

Changes in carotid flow velocity induced by direct percutaneous carotid angiography in man.

Quantitative percutaneous flow velocity measurements are possible in carotid arteries. The results of the direct percutaneous angiography were measured by means of a Doppler directional flow velocity device and registered on a polygraphy. The results indicate an increase in the flow velocity of the injected as well as the non-injected carotid system. This implies that there are no local constrictions of the carotid artery following intervention and, furthermore, it implies a systematic effect of the puncture and injection itself, or of the contrast medium, on the whole cerebral circulation. A diffuse vasodilatation, at least in the cerebral circulation, is postulated. The possible implications are discussed.

Adult

Changes in carotid flow velocity during catheterization of the aortic arch and common carotid artery.

Quantitative percutaneous flow velocity measurements are possible in carotid arteries by means of a directional Doppler flow velocity device and registration on a polygraph. Carotid flow velocity changes were recorded during catheterization of the ascending aorta and common carotid artery and after infusion of 20 cc contrast medium in the ascending aorta. The results indicate an increase in the flow velocity in the right common carotid artery after infusion of the contrast medium in the ascending aorta, which is thought to be attributed to a diffuse vasodilatation, at least in the cerebral circulation. The catheterization of the ascending aorta and common carotid artery seems to interfere with the common carotid flow velocity.

Adolescent