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Biomedical subjects

B C Barker

Publications and source records attributed to B C Barker.

At least 19 recordsLinked to original sources
PubMed1990

Iodinated contrast media effects on extravascular lung water, central blood volume, and cardiac output in humans.

Intravascular contrast media produce pulmonary edema in one rat model, but not in dogs or pigs. In humans, pulmonary edema after contrast media is rarely diagnosed, but subclinical edema could be more frequent than believed previously. Therefore, the authors prospectively studied the effects of diatrizoate (n = 5) and ioxaglate (n = 5) on extravascular lung water, central blood volume, and cardiac output in ten patients undergoing routine radiographic procedures. Variables were measured by thermal-dye dilution before and every 5 minutes after completion of the procedure for four repetitions. Extravascular lung water and central blood volume did not change significantly, indicating that pulmonary edema or pulmonary congestion did not occur. Cardiac output was elevated by 10.6% immediately after the procedure, but returned to baseline during the 10 following minutes. The authors conclude from this preliminary study in a small number of patients that intraarterial contrast media (less than 1.5 g/kg body weight of iodine) did not produce pulmonary edema or pulmonary congestion, even at a subclinical level.

Blood Volume↗
PubMed1990

Independence of intrapericardial right and left ventricular performance in septic pulmonary hypertension.

To study the effect of septic pulmonary hypertension on right/left ventricular intrapericardial interactions thirteen trauma patients, seven septic and six non-septic controls, were compared. Ventricular volumes were derived from first-pass or gated equilibrium radionuclide angiocardiography, and related to body surface area. Systemic and pulmonary pressures were measured invasively. Pulmonary arterial pressure was significantly increased in the sepsis group. Although right ventricular end-diastolic volumes were higher in sepsis, left ventricular end-diastolic volumes were not decreased. In terms of intrapericardial right/left ventricular interactions these results indicate that the right and left ventricles operate independently in septic pulmonary hypertension.

Adult↗
PubMed1989

Post-traumatic changes in, and effect of colloid osmotic pressure on the distribution of body water.

The aim of this study was to define the post-traumatic changes in body fluid compartments and to evaluate the effect of plasma colloid osmotic pressure (COP) on the partitioning of body fluid between these compartments. Forty-two measurements of plasma volume (green dye), extracellular volume (bromine), and total body water (deuterium) were done in ten traumatized patients (mean Injury Severity Score, ISS, = 34) and 23 similar control studies were done in eight healthy volunteers who were in stable fluid balance. Interstitial volume, intracellular volume, and blood volume were calculated from measured fluid spaces and hematocrit; COP was directly measured. Studies in volunteers on consecutive days indicated good reproducibility, with coefficients of variation equal to 3.5% for COP, 6.3% for plasma volume, 4.5% for extracellular volume, and 4.9% for total body water. COP values extended over the entire range seen clinically, from 10 to 30 mmHg. Interstitial volume was increased by 55% in patients, but intracellular volume was decreased by 10%. We conclude (1) that posttraumatic peripheral edema resulting from hemodilution is located in the interstitial compartment, with no intracellular space expansion; and (2) that interstitial volume, but not intracellular volume, is closely related to plasma COP.

Blood Proteins↗
PubMed1981

The pterygoideus proprius muscle.

An anomalous muscle was found in the infratemporal fossa of a male cadaver of advanced age. This formation passed between fixed bony attachments at the infratemporal crest (greater wing of the sphenoid) and the inferior part of the lateral pterygoid plate. The muscle was not atrophied but functional significance was not clear.

Humans↗
PubMed1980

Pulpal pain.

Explore the source record for details and available documents.

Dental Pulp↗
PubMed1977

Histology of external and internal resorption.

Seven cases of resorption in teeth have been described. Three had large internal cavities penetrating the dentine to or from the exterior. One had internal resorption in two separate locations and another had internal resorption which may have been precipitated by carious involvement of the pulp. Two cases of external resoprtion were quite dissimilar, one possibly a reaction to canal infection, the other idiopathic. Various types of calcified material were found in the areas of resorption and odontoclasts were found in one case.

Adolescent↗
PubMed1976

A rare local anesthetic misadventure. Case report and anatomic considerations.

When the mouth is fully opened, the depth to which the needle is inserted need not be great in order to pass through the submandibular gland capsule, and insertion of the needle behind the second molar tooth would result in passage behind the posterior border of the my-ohyoid muscle. The discussion indicates the relative ease with which fluid may penetrate the parapharyngeal space, particularly if pressure is used in injecting. Fluid diffusing into the region of the carotid triangle may have been responsible for the various symptoms, and anesthesia of the hypoglossal nerve, nerve, thyrohyoid nerve, internal and external laryngeal nerves, and carotid body possibly occurred. Anesthesia of the vagus is a remote possibility.

Adult↗
PubMed1975

Some unusual cases of apexification subsequent to trauma.

Three cases are reported in which apexification occurred without the benefit of endodontic treatment. These reports illustrate that immature teeth which are avulsed and replanted, dislocated and repositioned, or traumatized with pulp necrosis supervening, may progress to form complete apices without intracanal therapy. The value of using calcium hydroxide is not in question, but may not be as essential an aid to apical closure as was previously thought. In one case, the appearance of isolated apixes forming, deep in the bone after loss of very immature lateral incisors poses the question of whether this event does not occur more frequently after extraction of newly erupted or young impacted teeth.

Adolescent↗
PubMed1975

Anatomy of root canals. IV deciduous teeth.

The root canal systems of the deciduous teeth have been demonstrated by the epoxy resin injection technique. A major difference is noted between the simplicity of that seen in the incisors and the molars.

Child↗
PubMed1975

Relation of the alveolus to the cemento-enamel junction following attritional wear in aboriginal skulls. An enquiry into normality of cementum exposure with aging.

With tooth attrition, the height of the alveolar crest does not increase to keep pace with active tooth eruption and the cemento-enamel junction-alveolar crest distance increases slightly with age in aboriginal skulls. But there is no atrophy of the alveolar bony margin. Some decrease in interalveolar height does occur. This does not necessarily mean that passive eruption with exposure of cementum is normal. Rather it is postulated that the epithelial attachment proliferates onto cementum, inhibiting alveolar crest addition, while the base of the gingival sulcus remains at the cemento-enamel junction. During the course of this investigation, it was found that the distance between the cemento-enamel junction and alveolar crest increased more rapidly with advancing wear in the lower molar region than in the upper. In the lower first molar region, the lingual distance was significantly greater than that between cemento-enamel junction and alveolar crest on the buccal aspect during each stage of wear. The size of the tooth, as reflected in the robustness index, had no influence on the processes or rate of active eruption, bone deposition at the alveolar crest, or measurements taken between cemento-enamel junction and alveolar crest.

Aging↗