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Biomedical subjects

S M Joyce

Publications and source records attributed to S M Joyce.

At least 19 recordsLinked to original sources

Producing human therapeutic proteins in plastids.

Plastid transformation technology is set to become a major player in the production of human therapeutic proteins. Protein expression levels that can be achieved in plant plastids are hundreds of times greater than the expression levels generally obtained via nuclear transformation. Plastids can produce human proteins that are properly folded and are biologically active. Effective protein purification strategies and strategies that can achieve inducible plastid gene expression are being developed within the system. Plastid transformation technology has been extended to edible plant species, which could minimize down-stream processing costs and raises the possibility of "edible protein therapies". The system is limited by the fact that plastid-produced proteins are not glycosylated and that, at the moment, it can be difficult to predict protein stability within the plastid. The high level of protein expression that can be obtained in plastids could make it possible to produce high-value therapeutic proteins in plants on a scale that could be accommodated in contained glasshouse facilities and still be economically viable. Growing plastid-transformed plants under contained conditions, and coupled with the level of bio-safety conferred by maternal inheritance of plastid transgenes, would address many of the social and environmental concerns relating to plant based production of human therapeutic proteins.

Humans↗

Emergency medical services outcomes project I (EMSOP I): prioritizing conditions for outcomes research.

Over the past several years, out-of-hospital EMS have come under increased scrutiny regarding the value of the range of EMS as currently provided. We used frequency data and expert opinion to rank-order EMS conditions for children and adults based on their potential value for the study of effectiveness of EMS care. Relief of discomfort was the outcome parameter EMS professionals identified as having the most potential impact for the majority of children and adults in the top quartile conditions. Future work from this project will identify appropriate severity and outcome measures that can be used to study these priority conditions. The results from the first year of this project will assist those interested in EMS outcomes research to focus their efforts. Furthermore, the results suggest that nonmortality out-come measures, such as relief of discomfort, may be important parameters in determining EMS effectiveness.

Adolescent↗

Poisonous snakebite in Utah.

A retrospective study was done of poisonous snakebite in Utah to determine the current epidemiology and scope of treatment, reviewing emergency department logs and other sources statewide for a 69-month period. Of 61 cases of poisonous snakebite identified, 13 occurred in snake hobbyists or venom laboratory personnel and were considered nonaccidental, and 48 were inflicted by native noncaptive snakes. These bites were considered accidental, and all were presumed to be from rattlesnakes. Nearly three fourths of the victims were male, ranging in age from 2 to 56 years (mean, 22 years). Most accidental bites occurred in areas of high human populations, during the summer months, in the afternoon or evening hours, and during recreational activities. Of the 48 bites, 11 (23%) were provoked. Two thirds of bites were on the upper extremities, and a third were on the lower extremities. More than half of the victims had no first-aid treatment recorded. Of those who did receive first aid, many were subjected to possibly harmful treatments, including tourniquets and ice application. The median time to a hospital was 68 minutes, with a range of 15 to 440 minutes. Swelling and discoloration were the most common signs and pain and paresthesia the most common symptoms. Half the bites resulted in minimal or no envenomation, 17 (35%) produced moderate envenomation, and 6 (12%) severe envenomation. Most patients with moderate or severe envenomation received antivenin, but the dosages given were usually less than recommended dosages. Five patients received surgical treatment based on clinical findings. One child died in a snake-handling incident. Long-term morbidity was unknown due to lack of follow-up. The Utah Poison Control Center was poorly utilized as a reporting and informational resource.

Adolescent↗

An optically scanned EMS reporting form and analysis system for statewide use: development and five years' experience.

Analysis of emergency medical services (EMS) systems data is crucial to planning, education, research, and quality assurance programs. Currently, comparative analysis of EMS data between regions or states is virtually impossible due to wide variations in data collection and analysis methods. To devise a practical and uniform EMS reporting system, we referenced the minimum data set (MDS) established by the federal government in 1974 and surveyed 22 states known to be using uniform reporting systems. In developing our final data set, elements were added based on inclusion in the MDS, national survey results, a review of current EMS literature, and consensus of local EMS providers. This set of 48 elements then was incorporated into a reporting form using narrative and optically scanned formats, allowing automated data collection for computer analysis. After a pilot study, the system was improved to allow high-speed ink reading and large volume data storage and analysis using a microcomputer. This system has subsequently been adopted by seven states. The combined data base exceeds 250,000 cases. Error screening algorithms ensure data integrity and are also used for quality assurance. Customized output reports can be generated within minutes and have assisted in EMS quality assurance, planning, and research. We believe that the successful performance of this system supports the use of the suggested data elements as well as optical scanning and microcomputer analysis of EMS data.

Data Collection↗

A clinical comparison of the performance of four blood glucose reagent strips.

The widespread use of visually read blood glucose reagent strips for initiation of emergent treatment of hypoglycemia and hyperglycemia has produced concern over the accuracy of this method. This study evaluated the accuracy of Chemstrip bG (Bio-Dynamics, Boehringer Mannheim, Indianapolis, IN), Dextrostix (Ames, Miles Laboratories, Elkhart, IN), Glucostix (Ames), and Visidex II (Ames) as compared with hospital laboratory values in an emergency department (ED) setting. Blood samples from 96 ED patients were tested for glucose concentration by each of the four strips and by the hospital laboratory. Each strip was evaluated for sensitivity, specificity, correlation coefficient (r), 95% confidence intervals, and kappa statistic (kappa, a measure of agreement between nonparametric data) using laboratory values as reference. In addition, six observers scored each strip for ease of interpretation using an ordinal scale of 1 (poor) to 4 (excellent). From the samples, no patients were hypoglycemic (less than or equal to 60 mg/dL), 83 were euglycemic (greater than 60 and less than 160 mg/dL), and 13 were hyperglycemic (greater than or equal to 160 mg/dL). Results suggest that over the range of glucose concentration sampled, there is good to excellent correlation with laboratory values for all strips except Dextrostix. The lower r value for Dextrostix is in part artifact due to limitation of its range of measurement to less than or equal to 250 mg/dL. Decreased accuracy for all strips in the hyperglycemic range may have been attributable to small sample size. Chemstrip bG and Visidex II were found to be subjectively easier to interpret.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Glucose↗

Lack of efficacy of 'weighted' radiographs in diagnosing acute acromioclavicular separation.

The efficacy of "weighted" films in diagnosing grade 3 acromioclavicular (AC) sprains not evident on plain (unweighted) films was evaluated. Eighty-three pairs of radiographs, taken with and without weights, of patients with suspected AC injury were studied. The films were read in a randomized and blinded manner by a staff radiologist. Criteria for classifying AC injuries were: grade 1, less than 3 mm (or less than 50%) difference between the AC widths with a normal coracoclavicular (CC) distance; grade 2, greater than or equal to 3 mm (or greater than or equal to 50%) difference between the AC widths with a normal CC distance; and grade 3, greater than or equal to 5 mm (or greater than or equal to 50%) difference in CC distance. In only three cases (4%) did weights cause the injured CC distance to increase and thereby unmask a grade 3 injury not evident on plain films. Further evidence that weights may not reliably elucidate the degree of AC joint injury is suggested by the fact that in several cases the weights actually caused the injured and uninjured CC distance to decrease. We conclude that the use of weighted radiographs lacks efficacy in unmasking grade 3 AC sprains on radiograph and we recommend that routine use of this technique be abandoned.

Acromioclavicular Joint↗

Fetal toxicity associated with maternal carbon monoxide poisoning.

We report six cases of acute carbon monoxide poisoning during pregnancy. All of the women survived with good outcomes, but three cases were associated with fetal mortality. Two fetuses were delivered stillborn within 36 hours of exposure. One fetus remained alive in utero for 20 weeks and was delivered nonviable at 33 weeks gestation with multiple morphologic anomalies. Three pregnancies were carried to term and resulted in normal neonates. Maternal blood carboxyhemoglobin levels did not correlate with the concurrent severity of symptoms in the woman. Maternal symptoms at the site of exposure seemed to predict the risk of associated morbidity to the fetus. A single maternal carboxyhemoglobin level cannot be used to estimate fetal carboxyhemoglobin if the exposure pattern is not known.

Abnormalities, Multiple↗

Cervical spine stabilization in pediatric patients: evaluation of current techniques.

We evaluated the performance of commercially available infant and pediatric cervical collars, both alone and in combination with commonly used supplemental devices (eg, Kendrick Extrication Device, half-spine board). One infant and 11 pediatric-sized collars were tested on mannequins representing an infant and a 5-year old child. Maximum forces generated by cooperative children were measured, then applied to the mannequins to reproduce head and neck flexion, extension, rotation, and lateral motion. Limitation of motion was measured in each direction for each collar and combination method. In general, collars of rigid plastic construction performed better than did foam types. However, when used alone none of the collars provided acceptable immobilization, with even the best allowing 17 degrees flexion, 19 degrees extension, 4 degrees rotation, and 6 degrees lateral motion. When combined with supplemental devices, immobilization to 3 degrees or less in any direction could be achieved. Findings were verified using cooperative children and selected collars. Overall, combination methods were more effective than cervical collars alone (P less than .001) or supplemental devices alone (P less than .05). The modified half-spine board used with a rigid collar and tape was the most effective combination method. We conclude that prehospital cervical spine stabilization in pediatric patients is best accomplished using a rigid-type cervical collar in combination with supplemental devices as described.

Child↗

Beer potomania: an unusual cause of symptomatic hyponatremia.

A 43-year-old woman presented to the emergency department with acute agitation, confusion, and tonic seizures. She had a history of drug abuse, most notably beer, which constituted her major dietary intake. The patient's seizures were at first thought to be factitious in association with an acute psychosis; however, her serum sodium concentration was 110 mEq/L and urine sodium was 14 mEq/L. The patient responded to IV hypertonic saline and subsequently recovered completely. Beer potomania, the most likely etiology for this patient's hyponatremia, is a rare disorder in which dietary sodium and protein insufficiency lead to dilutional hyponatremia.

Adult↗

Sputum analysis and culture.

Sputum analysis and culture is the most common method of specific diagnosis of lower respiratory tract infections. Culture of a properly screened, expectorated sputum sample will identify the pathogen in most cases of bacterial pneumonia. Expectorated sputa, as well as those obtained by aspiration from the upper airway, are subject to oropharyngeal bacterial contamination. Other techniques, such as transtracheal aspiration, are more "sterile," but have a much higher incidence of morbidity. Microscopic screening of expectorated or aspirated sputum samples will reduce the number and increase the diagnostic accuracy of cultures, resulting in considerable cost savings. Mucopurulent material is selected by gross inspection, and microscopic examination of a wet mount and Gram stain yields information about cell type and predominant organism. More important, however, the presence of fewer than 25 squamous epithelial cells per low-power field indicates that true lower respiratory tract secretions have been collected. Culture results must be correlated carefully with semiquantitative grading, initial microscopic screening, clinical presentation, and response to initial therapy. When properly performed and interpreted, sputum analysis and culture are valuable tools in the diagnosis and treatment of lower respiratory tract infection.

Diagnostic Tests, Routine↗

Liquid crystal thermometry for continuous temperature measurement in emergency department patients.

A single temperature measurement recorded on admission to the emergency department provides no information about temperature alterations occurring during the course of evaluation. Continuous monitoring of patients' temperatures in the ED, however, may alter management and decrease morbidity. Our study evaluated the reliability of liquid crystal thermometers (LCTs) and the clinical benefit of continuous temperature monitoring in the ED. Commercially available LCTs (corrected 4 degrees F to reflect core temperature) were applied to the foreheads of randomly selected patients. Serial oral electronic thermometer readings were compared to those obtained by LCT. Fever was defined as a temperature higher than 99.5 F orally or 100 F by LCT. One hundred two patients underwent simultaneous LCT and oral temperature measurements, with a correlation coefficient of 0.661. Hypothermia was not encountered. Eighty-four patients were afebrile, and 18 were febrile by oral measurement on admission. Of the afebrile patients, 13 (15.5%) became febrile while in the ED. The temperature course was identified correctly by LCT in 83.3% of cases. The LCT correctly identified all patients who were febrile on admission, as well as 92.3% of those who developed fever while in the ED. The latter fevers would have been missed by routine single-temperature determination on ED admission. Detection of fever stimulated more aggressive clinical evaluation of these patients. Eight of nine patients who defervesced in response to antipyretic therapy were identified correctly by LCT.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗

Central versus peripheral intravenous routes in cardiopulmonary resuscitation.

The central venous (CV) and peripheral venous (PV) routes of drug administration are generally considered to be equally effective during cardiopulmonary resuscitation (CPR). This canine study compared simulated drug delivery via CV and PV routes during CPR. The CV group dogs had a CV catheter placed via the external jugular vein, and the PV group dogs had a PV catheter placed in the distal forelimb. Thirty seconds after the induction of cardiac arrest with KCl, CPR was begun with a gas-powered chest compressor with ventilations after every fifth compression. Sixty seconds later, a 0.5 ml bolus of technetium 99m-labeled serum albumin was given. Time activity curves were obtained over the right and left ventricles. The mean time for the counts to rise to half the left ventricular peak (T1/2LV) was significantly less for the CV group than for the PV group (P less than 0.05), averaging 11 and 84 seconds, respectively. The time to left ventricular peak (TLV) was also statistically shorter for the CV group than the PV group, averaging 118 versus 258 seconds, respectively. This study demonstrates that central venous administration is more rapid than peripheral venous administration during CPR and supports the preferential use of the central venous route for drug administration clinically.

Animals↗

Comparison of superior vena caval and inferior vena caval access using a radioisotope technique during normal perfusion and cardiopulmonary resuscitation.

Recent studies of thoracic pressure changes during external cardiopulmonary resuscitation (CPR) suggest that there may be a significant difference in the rate of delivery of intravenous drugs when they are administered through the extrathoracic inferior vena cava (IVC) rather than the intrathoracic superior vena cava (SVC). Comparison of delivery of a radionuclide given using superior and inferior vena caval access sites was made during normal blood flow and during CPR. Mean times from injection to peak emission count in each ventricle were determined. There were no significant differences between mean peak times for SVC or IVC routes during normal flow or CPR. When peak times were corrected for variations in cardiac output, there were no significant differences between IVC and SVC peak times during normal flow. During CPR, however, mean left ventricular peak time, when corrected for cardiac output, was significantly shorter (P less than .05) when the SVC route was used. The mean time for the counts to reach half the ventricular peak was statistically shorter (P less than .05) in both ventricles with the SVC route during the low flow of CPR. This suggests that during CPR, increased drug dispersion may occur when drugs are infused by the IVC route and thus may modify the anticipated effect of the drug bolus. These results suggest that during CPR, both the cardiac output and the choice of venous access are important variables for drug delivery.

Animals↗

Effect of a pneumatic antishock garment on drug delivery via distal venous access.

We examined the effect of an inflated pneumatic antishock garment (PASG) on simulated drug delivery through a distally placed venous catheter, during both normal flow and cardiopulmonary resuscitation (CPR). A PASG device was applied to anesthetized mongrel dogs and was inflated to 60 mm Hg. A small bolus of radionuclide was injected through an intravenous catheter placed distal to the PASG. Emission counts were made over both ventricles during conditions of normal flow and then during CPR following cardiac arrest. Mean times from injection to peak counts were determined. A control group of animals with central venous catheters but no PASG was studied similarly. There were no clinically appreciable differences between groups during normal flow. During CPR the PASG animals showed a mean delay of 90 seconds to the left ventricle peak. This difference was not statistically significant. We conclude that, in this canine model, acceptable delivery of drugs can be obtained by venous infusion into a limb with a PASG inflated.

Animals↗