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Biomedical subjects

C E Barr

Publications and source records attributed to C E Barr.

At least 37 records · Page 2Linked to original sources
PubMed1986

The electroencephalographic pattern during electroconvulsive therapy. III. Analysis of frontotemporal and nasopharyngeal spectral energy.

This study analyzes the frontotemporal and nasopharyngeal spectral energy of an ECT-induced seizure, in order to investigate the origin of the final Phase III activity, which contains most of the seizure's energy. Data supports these findings: energy in the delta frequency band is responsible for the generation, propagation, and maintenance of Phase III of the ECT-induced seizure; the synchronous "delta-firing" depolarizations of Phase III are recurrently initiated by an ECT-induced "generator" process; higher magnitudes of energy are generated centrally than are generated laterally during Phase III; and the lessened memory impairment associated with nondominant unilateral ECT is attributable to the markedly lower peak and total energies observed in the unstimulated temporal lobe.

Brain↗
PubMed1985

Cytomegalovirus presence and salivary composition in acquired immunodeficiency syndrome.

Parotid and whole saliva was collected from nine patients with acquired immunodeficiency syndrome (AIDS) and nine controls. Cytomegalovirus (CMV) was cultured from both salivary samples in six of the AIDS patients but was not present in any of the controls. In the AIDS samples parotid sodium (p less than 0.05), IgG (p less than 0.01), and albumin (p less than 0.05) were higher than in control samples. Parotid potassium (p less than 0.05) and total protein (p less than 0.05) were lower than control values, whereas flow rate, lactoferrin, lysozyme, IgA, and IgM levels were similar in both sets of samples. AIDS does not appear to affect secretory IgA levels. Sodium (p less than 0.01) and IgA (p less than 0.05) were higher in the whole saliva of AIDS patients. Serum IgG, IgM (p less than 0.01), and IgA (p less than 0.05) were also elevated when compared with the controls. The prevalence of CMV in parotid and whole saliva of AIDS patients is consistent with the known susceptibility of this group to adventitious infection and the predilection of this virus for the salivary glands. The changes in salivary composition suggest a low level of inflammation, which occurs independently of the virus.

Acquired Immunodeficiency Syndrome↗
PubMed1984

Reduction of digoxin effect during the digoxin-quinidine interaction.

The effects of the digoxin-quinidine interaction on cardiac function was examined in healthy subjects. Our results indicate that while serum digoxin levels were elevated, the improved cardiac function due to digoxin declined during combined therapy. Our data also provide an alternate explanation for the changes previously interpreted as "enhanced digitalis effects" during the interaction.

Adult↗
PubMed1983

Myopathy in acromegaly. A case study.

The muscle findings in a patient with acromegaly of 20 years duration are presented. The patient demonstrated mild muscular weakness and atrophy. Standard needle electromyography was normal and single fiber electromyography showed normal motor unit densities. Muscle biopsy revealed normal size type-I muscle fibers, but three populations of type-II fibers - hypertrophied, atrophied, and normal-sized fibers. Hypertrophy of type-II fibers may be the direct result of the excess growth hormone, while the atrophic fibers may result from the disturbance of other endocrine function.

Acromegaly↗
PubMed1983

A practicum for oral cancer teaching.

This article describes a hospital-based method for teaching oral cancer to general practice residents, which involves the use of patients for whom the residents are responsible. The residents present prepared cases of patients of the hospital dental department according to a predetermined protocol. These conferences begin with a talk on a subject germane to the cases being presented and include complete documentation of clinical history and laboratory findings, photographs, projection of microscope slides of the lesion, and a thorough discussion of therapy and rehabilitation. The residents have had significant contact with the cancer patients from the time of initial patient complaint to completion of therapy. The practicum is based on thorough case review and builds on didactic information provided in the undergraduate dental school curriculum.

Education, Dental↗
PubMed1982

H Uptake and Extrusion by Nitella clavata.

Very high rates of H(+) extrusion by internodal cells of Nitella clavata Kutz were measured after acid loading at pH 4.6. The highest rate observed, 160 picomoles per square centimeter per second, was more than twice the rate of photosynthetic bicarbonate utilization under saturating light. These results are consistent with the recently proposed hypothesis that bicarbonate is not taken in directly but is protonated at the exterior surface; the CO(2) thereby formed diffuses preferentially into the cell because of the asymmetric concentration gradient.The H(+) taken up, about 150 nanomoles per square centimeter in 2 hours, was distributed in three fractions: 30% in the cell wall, 40% in the cytoplasm, and 30% in the vacuole. This was concluded from the kinetics of the H(+) release by intact cells and isolated walls, and from the pH decrease of the vacuolar sap.The cytoplasmic H(+) was extruded rapidly, with a half-time of about 2 minutes when the external pH was 5.7 or higher. The extrusion of the vacuolar H(+) only proceeded at a measurable rate when the [K(+)] in the medium was raised to 20 millimolar; the half-time was about 100 minutes. There was little H(+) extruded when the external pH was 5.0.

Journal Article↗
PubMed1982

The electroencephalographic pattern during electroconvulsive therapy II. Preliminary analysis of spectral energy.

Computer assisted energy-spectral analyses were obtained on EEG recordings of unilateral non-dominant hemisphere ECT-induced seizures using the different pre-ECT anesthetic agents methohexital (Brevital), Innovar, and ketamine (Ketalar). The previously postulated predominance of electrical energy over the stimulated (right) hemisphere early in ECT-induced seizures is confirmed. There appears to be marked reduction in total seizure energy with methohexital anesthesia, whereas ketamine anesthesia appears to be associated with increased overall seizure energy. The greatest right to left energy transfer during the seizure occurred with Innovar anesthesia.

Adult↗
PubMed1980

Metastatic mucous-producing adenocarcinoma of the gingiva.

An unusual metastasis of adenocarcinoma of the lung to the gingival mucosa in a 75-year-old man is reported. The case presents an interesting differential clinical assessment as the gingival lesions seem to be of local nature and involve a combined endodontic-periodontic causation.

Adenocarcinoma, Mucinous↗
PubMed1979

A simplified method for intracavitary radiation for recurrent nasopharyngeal carcinoma.

A simplified method for constructing a custom-made mold to hold radium for intracavitary radiation therapy of recurrent nasopharyngeal carcinoma was developed. The technique for fabrication and insertion of the mold in a single operative procedure is described. Computer dose distributions were obtained and the applications were well tolerated by the patients.

Acrylic Resins↗
PubMed1978

Potassium transference in Nitella.

Transmembrane movements of K+ and Cl- were studied under a variety of experimental conditions. Potassium was found to carry more than 50% of an externally applied inward positive current. The increase in K+ influx was much greater than that predicted by the purely passive model. The increase in Cl- efflux accounted for less than 10% of the applied current, in agreement with the value predicted for passive movement. 2,4-Dinitrophenol (DNP) caused an 80% reduction in K+ transference and a corresponding increase in the measured electrical resistance of the membrane. DNP also reduced the isotopically measured resting K+ influx and caused a substantial increase in both Cl- influx and efflux. Lowering of the pH from 5.7 to 4.7 also reduced the net K+ influx but without drastically altering the membrane resistance. It appears the major portion of an externally applied current does not travel through passive channels, but rather is shunted through a different membrane component. In conjunction with evidence previously establishing the H+ pump as the primary ion pump in Nitella, the data presented here are consistent with a K+/H+ exchange mechanism which can account for the observed net K+ accumulation and maintenance of the membrane potential above the electrochemical equilibrium potential of the major ions. This mechanism appears to be a likely candidate for the current shunt.

Biological Transport, Active↗