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Biomedical subjects

D E Potts

Publications and source records attributed to D E Potts.

16 recordsLinked to original sources
PubMed1992

Transformation and inheritance of a hygromycin phosphotransferase gene in maize plants.

Embryogenic maize (Zea mays L.) callus cultures were transformed by microprojectile bombardment with a chimeric hygromycin phosphotransferase (HPT) gene and three transformed lines were obtained by selecting for hygromycin resistance. All lines contained one or a few copies of the intact HPT coding sequence. Fertile, transgenic plants were regenerated and the transmission of the chimeric gene was demonstrated through two complete generations. One line inherited the gene in the manner expected for a single, dominant locus, whereas two did not.

Base Sequence↗
PubMed1979

Emergency room intubations--complications and survival.

Forty-three consecutive patients requiring endotracheal intubation in an emergency room were studied prospectively to define the complications associated with intubation and the survival of these patients, and to evaluate emergency room policies. The indications for intubation were acute respiratory failure (ARF) in 22 patients and cardiopulmonary arrest (CPA) in 21 patients. Thirty-eight complications occurred in 24 of the 43 patients. The department or level of training of the intubator did not affect the rate of complications. Furthermore, specific complications did not influence survival. Seventeen patients survived, all in the ARF group. Age less than 40 years and admission PaO2 greater than 40 mm Hg also were associated with increased survival. We conclude that the complication rate of emergency room intubations is high and would not appear to be lowered by limiting intubations to physicians from specific departments or with certain levels of training. The underlying diagnosis and condition on admission to the emergency room appear to be more important factors relating to survival than complications during intubation.

Acute Disease↗
PubMed1979

The pH of sclerosing agents: a determinant of pleural symphysis.

The rate of success in producing pleural symphysis with intrapleural instillation of sclerosing agents has been variable. Differences in the designs of studies probably account for some of the variability, but the reasons for the remainder are not clear. Since a low pH of the pleural fluid is associated with pleural adhesions and loculations, the pH of the commonly used solutions of sclerosing agents was determined, both in their usual concentrations and when diluted with large quantities of exudative pleural fluid. The buffered solution of tetracycline hydrochloride had the most acidic pH (2.0) and showed little change when diluted by pleural fluid. A 0.5 percent solution of sodium hydroxide had the highest pH (13.0). The remainder of the sclerosing solutions showed a range of pH from 4.3 to 8.7. Experimental and clinical experience suggests that tetracycline consistently has the highest rate of success in producing pleural symphysis. It appears that when proper technique is employed, the pH of the solution of the sclerosing agent is an important determinant of the production of pleural symphysis.

Animals↗
PubMed1978

Thyrotoxicosis: comparison of effects of thyroid ablation and beta-adrenergic blockade on metabolic rate and ventilatory control.

To elucidate the role of the beta-sympathetic system in thyrotoxicosis (THY), we examined cardiac sensitivity to infused beta-agonist and compared the effect of beta-blockade with that of resolution of the hyperthyroid state. Beta-sympathetic (beta-SYM) sensitivity was measured as the heart rate response to isoproterenol in THY patients and in normal subjects. The patients with THY showed both lower threshold (P less than 0.05) and increased slope (P less than 0.05) of the heart rate-isoproterenol response, suggesting beta-SYM hypersensitivity. The beta-SYM like features of THY were measured in 7 patients before and 7 days after beta-SYM blockade with propranolol (mean dose 411 +/- 32 mg/day [SEM]) which was shown to block the heart rate response to isoproterenol. These results were compared with those in a similar group of thyrotoxic patients rendered euthyroid with 131I. During beta-SYM blockade, heart rate decreased from 101 +/- 6.3 to 78 +/- 4.6 (P less than 0.01), but the elevated metabolic rate (V02), resting ventilation (VE), and increased hypoxic and hypercapnic ventilatory responses were not significantly affected. In the group rendered euthyroid with 131I, heart rate decreased from 110 +/- 3.5 to 76 +/- 7.8 (P less than 0.02), but in contrast to the result of beta-SYM blockade, a 28% decrease in VO2 (P less than 0.01), 41% decrease in VE (P less than 0.05), a 38% decrease in hypercapnic ventilatory response (P less than 0.05), and a 66% decrease in hypoxic response (P less than 0.03) occurred. During THY, beta-SYM mechanisms are responsible for part of the tachycardia, but the metabolic and ventilatory abnormalities are not beta-SYM mediated.

Adult↗
PubMed1978

The glucose-pH relationship in parapneumonic effusions.

Both a low pleural fluid glucose concentration and pleural fluid acidosis are markers of severe pleural inflammation, but the relationship between these phenomena has not been defined clearly. Therefore, we measured simultaneous pleural fluid glucose concentrations and pH in 25 consecutive parapneumonic pleural fluids. Seventeen effusions had a glucose concentration greater than 60 mg/dl (group 1, 126 +/- 7 mg/dl, mean +/- SEM), while eight had a pleural fluid glucose less than 60 mg/dl (group 2, 15 +/- 3 mg/dl, P less than .01). Pleural fluid pH was 7.35 +/- 0.03 in group 1 compared with 6.83 +/- 0.09 in group 2 (P less than .01). A significant correlation between pleural fluid glucose and pH was found (r = .81, P less than .01). Low-glucose, low-pH effusions were complicated (either loculated or empyemas). Uncomplicated effusions had glucose concentrations greater than 60 mg/dl and a pleural fluid pH greater than 7.30. The concomitant occurrence of low pleural fluid glucose and pH suggests that the mechanisms leading to these phenomena are interrelated.

Glucose↗
PubMed1978

Acid-base disturbances in the salicylate-intoxicated adult.

This study examined the acid-base disturbances in 67 adults with salicylate intoxication. On admission, 66 patients had an acid-base distrubance. In contract to previous suggestions, however, only 25% of the patients had simple respiratory alkalosis. Unlike salicylate intoxication in children, 33% of these adults with salicylate intoxication had ingested additional drugs. These additional drugs generally were CNS depressants and were important determinants of the variety of the acid-base disturbance. Those patients who ingested additional drugs had a significantly lower incidence of respiratory alkalosis (P less than .005) and a higher incidence of respiratory acidosis (P less than .005) and acidemia (P less than 0.25). The incidence of acidemia correlated with the presence of neurological symptoms.

Acid-Base Imbalance↗
PubMed1976

Abdominal manifestations of pulmonary embolism.

The cardiopulmonary manifestations of acute pulmonary embolism are well known. However, abdominal manifestations of thromboembolic disease are less well appreciated. We recently encountered three patients with pulmonary emboli who also had complications of abdominal signs and symptoms. Two patients initially had abdominal complaints that obscured the diagnosis. In the other patient, symptoms and signs developed that were indistinguishable from an acute surgical condition of the abdomen after the diagnosis of massive pulmonary embolism was established. Abdominal manifestations alone may be the presenting features of pulmonary embolism or may complicate the clinical course.

Abdomen, Acute↗
PubMed1976

Pleural fluid pH in parapneumonic effusions.

The pH and carbon dioxide tension were measured in 24 consecutive parapneumonic effusions, along with the leukocyte count, leukocytic differential count, and levels of glucose and protein. Three categories of parapneumonic effusions were characterized: (1) empyemas; (2) benign (nonloculated) effusions; and (3) loculated effusions. A pH greater than 7.30 was present in all ten benign effusions, and spontaneous resolution occurred in each case. All ten empyemas and the four loculated effusions had a pH less than 7.30. All four loculated effusions required drainage with a chest tube for resolution. The pH of the pleural fluid alone separated the empyemas and loculated effusions from benign effusions. The early separation of parapneumonic effusions on the basis of the pleural fluid appears useful. If the pH is greater than 7.30, a benign effusion is present, and spontaneous resolution is likely. If the pH is less than 7.30, loculation of the pleural space may occur regardless of whether the effusion fulfills the criteria for empyema.

Drainage↗
PubMed1976

Unrecognized adult salicylate intoxication.

Adult salicylate intoxication has been considered to be easily recognized and assciated with low morbidity and mortality. In the present study of 73 consecutive adults hospitalized with salicylate intoxication, 27% of patients were undiagnosed for as long as 72 h after admission. The initial physical findings and laboratory data in patients not diagnosed on admission did not markedly differ from the findings in patients diagnosed on admission, and included tachypnea and acid-based disturbances as well as the frequent occurrence of neurologic abnormalities. However, patients with a delayed diagnosis of salicylate intoxication were older, rarely had a previous history of drug overdose, and more often became accidentally intoxicated while ingesting salicylate for associated medical illnesses when compared with patients diagnosed on admission. Moratlity was encountered with significantly greater frequency in patients with delayed diagnosis, and, consequently, delayed therapy, when compared with patients diagnosed on admission.

Adolescent↗
PubMed1975

Syndrome and pancreatic disease, subcutaneous fat necrosis and polyserositis. Case report and review of literature.

Immunologic evaluation of a patient with pancreatitis, subcutaneous fat necrosis, pleuritis, pericarditis and synovitis is presented. The previously recognized syndrome of pancreatic disease, subcutaneous fat necrosis and arthritis is reviewed. Based on analysis of all the cases described in the English language literature it is suggested that this syndrome be expanded to include polyserositis rather than arthritis alone. Although experimental and clinical evidence tends to implicate physiocochemical tissue injury by pancreatic lipase as the primary pathogenic mechanism in this syndrome, studies in our patient suggest the possible contribution of immune-mediated injury. Supporting data include eosinophilia, biopsy demonstration of vasculitis antedating the subcutaneous fat necrosis, immunofluorescent identification of immunoglobulin G (IgG) and C3 in the pleura, and reduced levels of total hemolytic complement in the serum, and pleural and pericardial effusions.

Adipose Tissue↗
PubMedDate not supplied

Cellular content of the normal rabbit pleural space.

The cellular content of the pleural space of five normal rabbits was studied by three cytopreparative techniques using different methods of collection (aspiration, irrigation) and fixation (95% ethyl alcohol, 50% alcohol: 1% polyethylene glycol). The method using aspiration, 95% ethyl alcohol fixation, and the Papanicolaou stain was simple and provided the best cytologic detail. With this method 70.1% of pleural fluid cells were monocytic, 7.5% were monocytic with morphologic features typical of macrophages, 10.5% were lymphocytes, 8.9% were mesothelial cells and 1.9% were polymorphonuclear leukocytes. Other methods were technically more difficult and provided less cytologic detail. The cellular content of the normal rabbit pleural space is described, providing baseline information for the study of experimental pleural disease.

Animals↗