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.

Staphylococcal nasal carriage in medical students with varying clinical exposure.

Nasal carriage and antibiotic sensitivities of coagulase-positive and coagulase-negative staphylococci were assessed among medical students of three different years. Although carriage rates did not change, there was a trend towards multiple resistance with increasing hospital exposure. Gentamicin resistance in Staphylococcus albus showed a similar trend. The relevance of these findings to current views on the origin of gentamicin resistance is discussed.

Acute compartment syndrome following a minor athletic injury.

An athletic young male presented with right calf pain following a twisting injury during a soccer game. Other than apparently severe calf pain, no symptoms or signs of compartment syndrome were noted. The patient later returned with lateral and anterior compartment syndrome, and suffered partial loss of peroneal nerve and muscle function despite fasciotomy. Although rare, acute compartment syndrome resulting from seemingly minor injury or exertion has been reported. Pain out of proportion to the apparent injury and a history of chronic leg pain with exertion may be helpful in identifying these patients prior to development of more obvious signs and symptoms. The diagnosis of acute compartment syndrome may be confirmed by compartmental pressure measurement. Prompt intervention is indicated once the diagnosis is established.

Beriberi heart disease in a schizophrenic with an unusual diet.

A 37-year-old male presented with peripheral edema of sudden onset. Other signs of heart failure were absent. Subsequent evaluation revealed that the patient was a schizophrenic whose diet consisted almost entirely of carbohydrates. A clinical diagnosis of beriberi heart disease was made and the patient improved dramatically within several days of thiamine supplementation. The presentation of beriberi heart disease in developed countries is discussed. Emphasis is placed on food faddists and psychiatric patients in whom clinical findings may be subtle or absent.

Evaluation of a new cervical immobilization/extrication device.

UNLABELLED: A new cervical immobilization device (the Philadelphia Red E.M. Collar with Head Immobilizer/Stabilizer), has been introduced as an adjunct in extricating potentially neck-injured patients. This study compared the efficacy of immobilization using the collar to that of a short spine board. In addition, experienced EMS personnel rated the collar in simulated field situations. METHODS: In Part I of the study, the collar and a short spine board were applied to 25 adult volunteers in a sitting position, using standard methods. Each subject then exerted maximal force in flexion, extension, rotation, and abduction. Degrees of head motion from neutral position were measured in each direction. Mean values were compared using Student's t-test. For Part II, 10 EMS personnel were asked to apply the collar to volunteers. Each rated the performance of the collar on a scale of 1 (poor) to 4 (excellent) regarding: ease of application (sitting and supine), ease of extrication (lifting, logrolling, transfer), access to patient (chest auscultation, CPR, airway management), storage, and overall utility. RESULTS: The collar was significantly better than the short spine board in both lateral and rotational immobilization (p less than 0.001). There was no significant difference for flexion or extension (p greater than 0.05). The Red E.M. limited motion to a mean of 15 degrees or less in any direction. Ratings by EMS personnel for the device (mean+/- standard error) were: ease of application (sitting) 3.5+/-0.2, (supine) 2.7+/-0.2; ease of extrication 3.1+/-0.2; access to patient 3.4+/-0.2; storage 3.1+/-0.3; and overall utility 3.1+/-0.2.(ABSTRACT TRUNCATED AT 250 WORDS)

Epidemiology of pediatric EMS practice: a multistate analysis.

OBJECTIVE: To describe the epidemiology of pediatric emergency medical services (EMS) practice in a large patient population from several geographic areas. DESIGN: Retrospective computer analysis of EMS databases from four states using a common data set and analysis system. SETTING: Pennsylvania, Tennessee, Mississippi, and Nevada (except Clark County), 1990 through 1992. METHODS: All patient-care reports of patients 14 years old and younger were extracted from the EMS databases and analyzed for the following factors: age, gender, date, elapsed prehospital times, incident type, mechanism of injury, call disposition, illness or injuries encountered, severity of illness/injury (by abnormal vital signs), and basic life support (BLS) and advanced life support (ALS) treatment delivered. RESULTS: A total of 1,512,907 patient care reports were reviewed. Those of 61,132 children were extracted for analysis. These children comprised about 4% of prehospital responses. Male subjects predominated (56%), and children aged 7 through 14 years represented 46% of cases. Most calls occurred in the evening and daylight hours. Children were transported by ambulance in 89% of cases, and care was refused in 7.7%. Mean response time was 9 +/- 16 minutes, mean scene time 12 +/- 14 minutes, and mean transport time 14 +/- 20 minutes. Traumatic incidents predominated at 42%, with motor vehicle accidents and falls the most common mechanisms. Blunt injuries accounted for 94% of trauma, whereas respiratory problems, seizures, and poisoning/overdose were the most common medical problems. Vital signs were obtained in 56% of cases. Abnormal vital signs were noted in 21% of these, and the presumptive causes were similar in distribution to those of the general population, with the addition of cardiac arrest. The most commonly used treatments were spinal immobilization, oxygen administration, intravenous access and several ALS medications. An ALS capability was available in more than half the runs, but ALS treatment was delivered in only 14% of those cases. Outcome data were not available. CONCLUSION: This multistate analysis of pediatric EMS epidemiology confirms findings reported in smaller regional studies, with several exceptions. Excessive scene times were not noted. Few children had serious disorders as evidenced by abnormal vital signs. An ALS treatment, when available, was used infrequently. These findings have implications for EMS planners and educators.

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.

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)

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.

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.

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.

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.

Efficacy of an EMS quality improvement program in improving documentation and performance.

OBJECTIVE: Change from quality assurance (QA) to quality improvement (QI) in EMS has been adopted by many systems. This study sought to determine whether QI is effective in this setting. METHODS: A QI program comprised of prospective, concurrent, and retrospective components was instituted in 1994 by the Salt Lake City Fire Department. The retrospective component of the program consisted of monthly random audits of approximately 6% of EMS patient care reports (PCRs), both ALS and BLS. PCRs were evaluated for adequate documentation of six patient assessment parameters, appropriate treatment, and short-term outcome. Time intervals and adherence to protocol were also evaluated. Overall documentation and performance were rated. Monthly and cumulative QI reports were circulated to all providers, and both positive feedback and negative feedback were provided to specific crews. Continuing medical education sessions were tailored to address problems identified by the QI audits and scene observation. Results of 1,862 reviews from 1994-1995 were compared with baseline figures from 1993. RESULTS: Response, scene, and transport times were acceptable in more than 90% of cases in both the baseline and the study periods. Statistically significant improvements were noted in the following parameters: documentation of patient assessment, protocol compliance, patient disposition, overall documentation, overall performance, and need for further review. In nontransport cases, both appropriateness of the release decision and acquisition of appropriate signatures improved, but not significantly. CONCLUSION: Significant improvements were noted in 13 of 19 parameters and goals were met in 14, with results sustained over the two-year study period. A quality improvement program can effect significant and sustained improvement in documentation and performance in an EMS system.

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.

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.

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)

Outcomes of sudden cardiac arrest treated with defibrillation by emergency medical technicians (EMT-Ds) or paramedics in a two-tiered urban EMS system.

OBJECTIVE: Controversy exists as to the effectiveness of defibrillation by emergency medical technicians (EMT-Ds) in reducing mortality from cardiac arrest in two-tiered EMS systems. This study was performed to assess the impact of EMT-Ds on outcome of sudden cardiac death in a small, urban, modified two-tiered EMS system. METHODS: This was a retrospective, unmatched case-control study comparing the outcomes of patients suffering sudden cardiac death treated by EMT-Ds with paramedic (EMT-P) backup with the outcomes of patients treated by EMT-Ps as first responders. Outcomes were defined as survival to the following endpoints: hospital admission, hospital discharge, and discharge with normal neurologic function (neurologic survival). Differences between groups were considered significant if p < or = 0.05 by Fisher's exact test or t-test. RESULTS: Three hundred twenty-two patients suffered out-of hospital sudden cardiac deaths over a three-year period and met study inclusion criteria. There were no significant differences in mean age, sex distribution, or incidence of ventricular fibrillation as the presenting rhythm between the groups. Rates of survival to admission, survival to discharge, and neurologic survival were 25.8%, 8.1%, and 5.6%, respectively. Corresponding survival rates for 46 patients treated first by EMT-Ds were 19.6%, 8.7%, and 4.3%. For 276 patients treated by EMT-Ps as first responders, the rates were 26.8%, 8.0%, and 5.8%. There were no significant differences in survival rates between the two response modes, despite a significantly shorter response interval for EMT-Ds (3.6 +/- 1.8 min, vs 4.6 +/- 2.0 min for EMT-Ps). There were likewise no significant differences in survival rates between the two response modes when only patients in ventricular fibrillation or ventricular tachycardia were considered. There were no significant differences in survival rates grouped by presenting rhythm, with the exception of 9.6% neurologic survival in witnessed ventricular fibrillation as compared with 0% in asystole. CONCLUSION: EMT defibrillation had no impact on outcome of sudden cardiac death in this small, urban, two-tiered EMS system. Survival rates were similar to those reported for other such systems. However, power to detect significant differences was low, and further study is indicated. Controlled multicenter trials are recommended.

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.

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.