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Biomedical subjects

W H Olson

Publications and source records attributed to W H Olson.

At least 19 recordsLinked to original sources
PubMed1989

Effect of diltiazem on 2,4-D-induced myotonia in rats.

Myotonia is characterized by prolonged contraction (delay in onset of relaxation) of skeletal muscle fibers with characteristic electromyographic findings. Calcium channel blocking drugs may be expected to reduce myotonia, should they promote the onset of relaxation in a contracted skeletal muscle. This study was aimed at evaluating the effect of diltiazem, a calcium channel blocking agent, on myotonia induced by 2,4-dichlorophenoxyacetic acid (2,4-D). In rat diaphragm, exposed to 2.5 mM 2,4-D in a tissue bath, myotonia was quantified by documenting the contraction time in response to direct stimulation with supramaximal electric stimuli. At the peak of myotonia, different concentrations of diltiazem were added to the tissue bath and the effect on evoked contraction studied over a period of 6 minutes. A concentration of 5 x 10(-5) M was found to be the most effective, causing a decrease in contraction time of more than 90% in 3 minutes in 100% of specimens (n = 7). The above findings raise the possibility of using diltiazem as an antimyotonic agent.

2,4-Dichlorophenoxyacetic Acid↗
PubMed1987

Bone marking for biopsy using radionuclide bone imaging.

If bone biopsies are performed after the sites are located under radionuclide guidance, the chances of sampling the pathologic tissue are greatly improved. After bone scanning, two to three areas for biopsy are chosen and locating is done with 0.05 ml of Tc-99m in a tuberculin syringe under an Anger camera. Methylene blue-xylocaine is injected into the skin up to the periosteum for marking the site of the biopsy. Using this technique, 27 biopsies in 20 patients have been performed (four were open and 23 were closed needle). Pathology was found in 25 biopsies (92.6%), cancer in 22 (81.5%), benign lesions in three (11.1%), and normal bone in two (7.4%).

Adult↗
PubMed1986

Temporal stability of sequential pulse defibrillation threshold.

We have shown that sequential pulse defibrillation threshold voltage and total delivered energy do not change with maturation of the electrode tissue interface for up to 12 weeks after implantation of two different electrode configurations. This result is important to predict the future performance of an implantable defibrillator that is tested only at implant.

Animals↗
PubMed1985

Pacemaker diagnostic diagrams.

Dual-chamber pacemakers interact with cardiac rhythms in complex ways. The resultant surface electrocardiograms (ECGs) are often very difficult to interpret. A simple and automatic diagnostic diagram is described that graphically illustrates pacemaker-heart interactions. Pacemaker operation is explained by a continuous series of lines and symbols that interconnect any sequence of paced and sensed events in both chambers. Fixed, programmable, and adaptive pacemaker timing intervals are all shown in a simple format. The pacemaker diagnostic diagram is plotted directly below the ECG to help users interpret the paced cardiac rhythm. The pacemaker diagnostic diagram is generated by software in a pacemaker programmer from: (1) telemetered real-time event markers; (2) fixed and programmable timing parameters (lower rate, AV interval, etc.); (3) pacemaker conditional logic. If this computer analysis of the telemetered event markers is not consistent with normal pacemaker operation, a specific error-message is printed. The pacemaker diagnostic diagram should be useful for instruction, pacemaker follow-up, and troubleshooting.

Arrhythmias, Cardiac↗
PubMed1978

Therapeutic trial of tilorone in ALS: lack of benefit in a double-blind, placebo-controlled study.

Sixteen patients with amyotrophic lateral sclerosis (ALS) participated in a double-blind, placebo-controlled study using tilorone hydrochloride, a drug active against a variety of DNA and RNA viruses in animals. On the basis of neurologic examination, pulmonary function studies, quantitative muscle examination, speech recording, and periodic filming of functional muscle strength, it was concluded that at a dose of 1 gm per week, tilorone did not alter the course of ALS.

Adult↗
PubMed1977

Positive (99mTc) diphosphonate and 67 Ga-citrate scans in ameloblastoma: case report.

Technetium-99m-diphosphonate scintigrams and 67Ga citrate bone scans were performed in a patient with known ameloblastoma of the right mandible. The tumor concentrated both radionuclides avidly. The lesion was larger on the gallium scans, presumably due to inflammation of adjacent soft tissue and to poorer instrument resolution for 67Ga than for technitium. If a single radionuclide is to be selected for evaluating the extent of tumor in ameloblastoma, the bone-imaging agent is preferable.

Adult↗
PubMed1976

Imipramine-serotonin induced myopathy.

Imipramine and serotonin (5-HT) were used to produce a myopathy in rats. Imipramine was used to stimulate a defect in transport of 5-HT observed in the platelets of Duchenne's dystrophy patients. The most effective dosage schedule was imipramine, 10 mg per kilogram, for 7 days followed by 5-HT, 100 mg per kilogram, 6 hours after the final imipramine dose. A single series of injections produced focal groups of necrotic and regenerating muscle fibers. In some rats, multiple series of injections resulted in a chronic myopathy with a predilection for proximal muscles, particularly quadriceps. In addition to skeletal muscle lesions, focal areas of myocardial damage were seen. The affected rats had a marked elevation of plasma creatine phosphokinase (including MB isoenzyme), serum glutamic oxaloacetic transaminase, and lactic dehydrogenase. Femoral nerve section did not affect the development of muscle lesions.

Animals↗
PubMed1975

An improved method for examination of cerebrospinal fluid cells.

A new collection technique allows cytologic examination up to 2 weeks after lumbar puncture without loss of cells or morphologic detail. Cerebrospinal fluid (CSF) was allowed to flow directly from a lumbar puncture needle into a solution of Carbowax in ethanol and was then processed with a cytocentrifuge. Two groups of patients were studied -- those undergoing spinal anesthesia and those having myelography for low back pain. Lymphocytes, polymorphonuclear neutrophils, and ependymal cells were regularly found in the CSF; a definite difference was found in the quantity and cell types in the two patient populations. The proposed method may be sensitive enough to aid in the identification of other neurologic diseases with low cell counts.

Adult↗