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Biomedical subjects

J W Jackson

Publications and source records attributed to J W Jackson.

At least 19 recordsLinked to original sources
PubMed1991

Common methodological framework for theory construction and evaluation in the social and behavioral sciences.

In this article, we have presented a general methodological framework for the construction and evaluation of social scientific theories in any domain of human ecology. In addition, we have presented some common fallacies and pitfalls in the nature and construction of scientific theories along with a discussion of 10 basic dichotomous issues important for evaluating contemporary theories and models. Finally, for the positive movement of future scientific work, we have summarized seven major weaknesses and needs in contemporary social scientific research and described the application of the proposed framework to the analysis of 46 child abuse and neglect theories to illustrate the importance of a multidisciplinary integration of future theory development and evaluation through the proposed methodological guidelines.

Humans↗
PubMed1982

A bifurcated silicone rubber stent for relief of tracheobronchial obstruction.

Though the techniques for surgical treatment after postintubation tracheal stenoses are well defined, the management of major airway obstruction by tracheal tumor, external compression, or diffuse intrinsic tracheal disease below the thoracic inlet still presents a difficult problem. Existing methods do not provide safe and effective relief at the level of the distal trachea, carina, and main bronchi. This report describes a bifurcated silicone rubber stent initially designed to preserve patency of the airways in a patient after severe and diffuse scalding injury to the trachea and main bronchi. This stent has since been used to provide relief from airway obstruction by tracheal or mediastinal tumors below the thoracic inlet. The method for insertion by tracheostomy with guide bougies passed under direct bronchoscopic vision past the obstructing lesion is described in detail and illustrated by reference to two patients with tracheobronchial obstruction. Once the tube is in place, the patient breathes normally through the mouth and nose and can speak, cough, or clear his own airway by suction if necessary. This method has proved a safe and effective means to restore patency of the major airways and provide relief from asphyxia while further treatment is planned or healing ensues. Our initial experience indicates that the tube may be allowed to remain in position for several months without adverse effects.

Adult↗
PubMed1981

Amino Acid Transport and stimulation by substrates in the absence of a Na2+ electrochemical potential gradient.

Uptake of alpha-aminoisobutyric acid (AIB) was examined in Ehrlich ascites tumor cells treated with the cation-exchange ionophore nigericin (20 microgram/ml). Membrane voltages were measured using the voltage-sensitive dye diethyloxadicarbocyanine (DOCC). In normal phosphate-buffered media, nigericin changed the distribution ratios of Na+ and K+ (the ratio of intra- to extracellular concentrations) nearly to unity, but AIB was still accumulated to a distribution ratio of approximately 9.0. When all but 40 mM Na+ in the medium was replaced by choline, nigericin resulted in K+ loss and Na+ gain and both cation distribution ratios approached 2.8-3.4, as would be expected if both ions were distributing near electrochemical equilibrium with a membrane voltage in the range of -28 to -33 mV. This conclusion was supported by the observation that the addition of 5 X 10(-7) M valinomycin to the nigericin-treated cell suspension produced no change in DOCC absorbance. In spite of the apparent zero electrochemical potential gradients for Na+ and K+, AIB was accumulated to a distribution ratio of 5.4 in the low-Na+ medium. Addition of 0.1 mM oubain or 50 microM vanadate did not alter the extent of AIB accumulation as would have been expected if a large component of the membrane voltage were due to electrogenic operation of the (Na+ + K+)-ATPase. Addition of lactate, pyruvate or glucose increased the AIB distribution ratios to 11.9, 9.4 and 15.3, respectively. The effect of glucose could be explained, at least in part, by an enhanced Na+ electrochemical potential gradient. However, neither lactate nor pyruvate produced any change either in membrane voltage or the intracellular Na+ concentration. Therefore, these results confirm the existence of a metabolic energy source which is coupled to AIB accumulation and operates in addition to the Na+ co-transport mechanism, and which is augmented by metabolic substrates such as lactate and pyruvate.

Amino Acids↗
PubMed1980

Chlordane sampling efficiency with Chromosorb 102 and ethylene glycol.

An organic polymeric solid, Chromosorb 102, has been reported to collect various pesticides from air. In this study the collection efficiency of Chromosorb 102 for chlordane was evaluated. Preparation of sampling tubes containing this medium for field sampling is also discussed.

Absorption↗
PubMed1979

Hypokalemic rhabdomyolysis and acute renal failure. Occurrence following total parenteral nutrition.

A patient experienced severe hypokalemia in the setting of prolonged nasogastric suction and total parenteral nutrition. Severe rhabdomyolysis and acute renal failure ensued. Review of the literature failed to disclose a similar case of hypokalemic rhabdomyolysis and acute renal failure, although the syndrome has been associated with other causes of hypokalemia, and its pathophysiology has been investigated in experimental models. The morbidity associated with extensive myonecrosis and severe, acute renal failure in this patient indicates that hypokalemia and other electrolyte abnormalities should be aggressively corrected in similar clinical settings.

Acute Kidney Injury↗
PubMed1979

The surgical management of malignant tumours of the oesophagus and cardia: a review of the results in 292 patients treated over a 15-year period (1961--75).

Of 292 patients, excision of the tumour with replacement by stomach or jejunum was carried out in 216 in whom the lesion was considered operable on both technical and general grounds, intubation was performed in 45 and the remaining 31 were managed without operation. Of the 216 in whom resection was performed, only 20 per cent were free from local spread, lymph node involvement or secondary deposits at the time of operation. Hospital mortality was 18 per cent and did not significantly differ between one 5-year period and another. Survival at 1 year was 54 per cent, at 2 years 25 per cent and at 5 years 14 per cent. The average length of survival following intubation was 2.6 months and following non-operative management 2.8 months. The poor average survival of between 3.5 and 5 months obtained in those patients with secondary deposits at the time of resection suggests that resection is of questionable value in this group. There was a marked difference in survival following Roux loop procedures compared with upper partial gastrectomy for tumours of the lower third and cardia in patients without lymph node involvement or secondary deposits, strongly suggesting that upper partial gastrectomy, although a rather simpler and quicker operation, is not the operation of choice in these patients. On 31 December 1976, after a minimum follow-up of 1 year, there were only 22 patients still alive of the original 292 (7.5 per cent).

Adult↗