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Biomedical subjects

Raymond E Jackson

Publications and source records attributed to Raymond E Jackson.

14 recordsLinked to original sources
PubMed2005

Isolation of chromosomal mutations that affect carotenoid production in Escherichia coli: mutations alter copy number of ColE1-type plasmids.

Chromosomal mutants were isolated in Escherichia coli that altered carotenoid production from transformed carotenoid biosynthesis genes on a pACYC-derived plasmid (pPCB15). The mutations were mapped by sequencing. One group of mutations appeared to affect the cell metabolism without changing the copy number of the carotenoid synthesis plasmid. The other group of mutations either increased or decreased the copy number of the pPCB15 plasmid as determined by real-time PCR. The copy number change in most mutants was likely specific for ColE1-type plasmids for which copy number is controlled by a small antisense RNA. This collection of host strains would be useful for fine tuning expression of proteins and adjusting production of desired molecules without recloning to different vectors.

Bacterial Proteins↗
PubMed2005

Directed evolution of copy number of a broad host range plasmid for metabolic engineering.

Random mutagenesis and directed evolution has been successfully used to improve desired properties of enzymes for biocatalysis and metabolic engineering. Here we employ the method to increase copy number of a pBBR-based broad host range plasmid, which can be used to express desired enzymes in a variety of microbial hosts. Localized random mutagenesis was performed in the replication control region of a pBBR-derived plasmid containing a beta-carotene reporter. Mutant plasmids were isolated that showed increased beta-carotene production. Real-time PCR analysis confirmed that the copy number of the mutant plasmids increased 3-7 fold. Sequence of the 10 mutant plasmids indicated that each plasmid contained single or multiple mutations in the rep gene or the flanking regions. Single amino acid change of serine to leucine at codon 100 of the replication protein and single nucleotide change of C to T at 46 bp upstream of the rep gene caused the increase of plasmid copy number. The utility of the mutant plasmids for metabolic engineering were further demonstrated by increased beta-carotene production, when an isoprenoid pathway gene (dxs) was co-expressed on a compatible plasmid. The mutant plasmids were tested in Agrobacterium tumefaciens. Increase of plasmid copy number and beta-carotene production was also observed in the non-Escherichia coli host.

Directed Molecular Evolution↗
PubMed2005

Proposed involvement of a soluble methane monooxygenase homologue in the cyclohexane-dependent growth of a new Brachymonas species.

High-throughput mRNA differential display (DD) was used to identify genes induced by cyclohexane in Brachymonas petroleovorans CHX, a recently isolated beta-proteobacterium that grows on cyclohexane. Two metabolic gene clusters were identified multiple times in independent reverse transcription polymerase chain reactions (RT-PCR) in the course of this DD experiment. These clusters encode genes believed to be required for cyclohexane metabolism. One gene cluster (8 kb) encodes the subunits of a multicomponent hydroxylase related to the soluble butane of Pseudomonas butanovora and methane monooxygenases (sMMO) of methanotrophs. We propose that this butane monooxygenase homologue carries out the oxidation of cyclohexane into cyclohexanol during growth. A second gene cluster (11 kb) contains almost all the genes required for the oxidation of cyclohexanol to adipic acid. Real-time PCR experiments confirmed that genes from both clusters are induced by cyclohexane. The role of the Baeyer-Villiger cyclohexanone monooxygenase of the second cluster was confirmed by heterologous expression in Escherichia coli.

Adipates↗
PubMed2003

Use of pulse oximetry to predict in-hospital complications in normotensive patients with pulmonary embolism.

PURPOSE: A simple method is needed to risk stratify normotensive patients with pulmonary embolism. We studied whether bedside clinical data can predict in-hospital complications from pulmonary embolism. METHODS: We performed a multicenter derivation phase, followed by validation in a single center. All patients were normotensive; the diagnosis of pulmonary embolism was established by objective imaging. Classification and regression analysis was performed to derive a decision tree from 27 parameters recorded from 207 patients. The validation study was conducted on a separate group of 96 patients to determine the derived criterion's diagnostic accuracy for in-hospital complications (cardiogenic shock, respiratory failure, or death). RESULTS: Mortality in the derivation phase was 4% (n = 8) at 24 hours and 10% (n = 21) at 30 days. A room-air pulse oximetry reading <95% was the most important predictor of death; mortality was 2% (95% confidence interval [CI]: 0% to 6%) in patients with pulse oximetry >or=95% versus 20% (95% CI: 12% to 29%) with pulse oximetry <95%. In the validation phase, the room-air pulse oximetry was <95% at the time of diagnosis in 9 of 10 patients who developed an in-hospital complication (sensitivity, 90%) and >or=95% in 55 of 86 patients without complications (specificity, 64%). CONCLUSION: Mortality from pulmonary embolism in normotensive patients is high. A room-air pulse oximetry reading >or=95% at diagnosis is associated with a significantly lower probability of in-hospital complications from pulmonary embolism.

Blood Pressure↗
PubMed2003

A randomized controlled trial of chest compression only CPR for older adults-a pilot study.

UNLABELLED: Older people are trained infrequently in cardiopulmonary resuscitation (CPR), yet are more likely to witness a cardiac arrest. Older people who are CPR trained perform CPR when witnessing a cardiac arrest. OBJECTIVE: To assess whether elderly adults (>55 years) who receive chest-compression only cardiopulmonary resuscitation (CC-CPR) training display equivalent skill retention rates compared with those who receive traditional CPR instruction. We also identified factors associated with 3 months skill retention at 3 months in both groups. METHODS: Older adults in a suburban hospital Older Adult Services program were invited to participate in an experimental CPR course. The 2 h course was modelled after the AHA Friends and Family course, and used one of two standardized video scenarios. Seventy four subjects were randomized to CC-CPR (n=36) or traditional CPR (n=38) training. Participation consisted of initial training, followed by a 3 months return videotaped assessment. Three months skill competence was assessed either by consensus between two video evaluators, or the on-site evaluator. Chi square and Kappa tests were used for analysis, and unadjusted odds ratios and 95% confidence intervals are reported. RESULTS: Skill retention assessments were completed on 29 (81%) CC-CPR and 26 (68%) CPR trainees. Subjects were elderly (71.5+/-6.69 years), and had a high rate of previous CPR training (58.0%). Groups were similar in demographic characteristics. After training, participants exhibited high rates of perceived competence (86.4%), although the overall 3 months skill retention was low (43.6%). CC-CPR training resulted in equivalent skill retention rates as compared with traditional CPR training (51.7 vs. 44.4%; P=0.586). No participant factors were associated with skill retention, including age, previous CPR training, education level, medical history, or perceived physical ability to perform. CONCLUSION: We identified low rates of CPR skill retention in this elderly population. CC-CPR instruction was associated with equivalent skill retention rates compared with traditional CPR instruction. No demographic factors were associated with successful skill retention.

Aged↗
PubMed2003

Intramuscular versus oral dexamethasone for the treatment of moderate-to-severe croup: a randomized, double-blind trial.

UNLABELLED: Glucocorticoids are an effective treatment for croup, although the most beneficial route of administration remains unclear. Recent studies have concluded that both intramuscular dexamethasone and oral dexamethasone are effective treatments, but there are few data directly comparing the two for moderate-to-severe croup. OBJECTIVES: The authors' primary objective was to determine whether there is a difference in proportion of children with resolution of symptoms attributable to croup at 24 hours, when treated with oral or intramuscular dexamethasone. Secondarily, the authors sought to estimate whether there is a difference in proportion of children with resolution of symptoms attributable to croup at 10 days and to estimate the interval to complete resolution of symptoms between these two routes. METHODS: The authors performed a prospective, randomized, double-blind trial involving children aged 3-84 months with moderate-to-severe croup, presenting to a suburban teaching emergency department (ED). Patients were eligible for enrollment if they had inspiratory stridor or a barky cough and a croup score of 2 or greater after 10-15 minutes of cool mist therapy. The patients were randomized to one of two intervention groups. In both groups, the parents were not present in the treatment room during study drug administration. One group received 0.6 mg/kg of intramuscular dexamethasone and an oral placebo, while the other group received 0.6 mg/kg of oral dexamethasone and direct pressure on their thigh with the hub of a syringe. A nurse placed a Band-Aid on the site of the real or mock injection. Parents were contacted by telephone approximately 1 and 10 days after the index visit to ask about their child's symptoms using a standardized questionnaire. Data were analyzed using an intention-to-treat approach. RESULTS: Of 126 patients eligible, 96 were recruited, with complete follow-up on 95. The groups were similar in all baseline characteristics, treatments received in the ED, and disposition. At 24 hours and 10 days after the visit, there were no statistical differences between the groups for the proportion with stridor, expiratory sounds, barky cough, sleep pattern, the degree of improvement, or the proportion with complete resolution of symptoms at one day. CONCLUSIONS: No statistical differences for any parameters were observed between intramuscular and oral dexamethasone treatments for children with moderate-to-severe croup at 24 hours or at any time the week after treatment. The durations of symptoms were similar between the treatment groups.

Administration, Oral↗
PubMed2003

Perceived self-efficacy in performing and willingness to learn cardiopulmonary resuscitation in an elderly population in a suburban community.

BACKGROUND: Older persons are the group most likely to respond to cardiac arrests in private residences. OBJECTIVE: To characterize the knowledge about, attitudes toward, and perceived self-efficacy of older persons in learning and providing cardiopulmonary resuscitation. METHODS: A total of 2743 surveys were mailed to adults 55 years and older who resided in a single Michigan suburb. Data were collected on demographics, medical history, training in and willingness to provide cardiopulmonary resuscitation, and concerns about providing this intervention. RESULTS: The 631 persons (24.6%) who responded were elderly (mean age, 73.5 years) and had a mean of 1.7 occupants per household. More than one third lived alone. Of all respondents, 275 (43.6%) had received training in cardiopulmonary resuscitation, 370 (58.6%) indicated a willingness to learn cardiopulmonary resuscitation, and 412 (65.3%) thought that they had the ability to perform this intervention. Respondents 80 years or younger were significantly more likely than respondents more than 80 years old to be willing to learn cardiopulmonary resuscitation (65.7% vs 19.0%, P < .001) and perceived themselves as able to perform it (73.0% vs 34.0%, P < .001). The absence of mouth-to-mouth ventilation as part of training had minimal impact on the willingness of either age group to receive training (61.2% vs 58.6%, P = .19). Perceived ability to learn and perform cardiopulmonary resuscitation did not vary with the medical history of the respondent or the respondent's spouse. CONCLUSION: Adults 56 to 80 years old perceive themselves as able to perform cardiopulmonary resuscitation and are interested in receiving training.

Aged↗
PubMed2002

Estimated cost effectiveness of a police automated external defibrillator program in a suburban community: 7 years experience.

OBJECTIVE: To estimate the cost effectiveness of a 7-year police automatic external defibrillator (AED) program in four suburban communities. METHOD: 10-year retrospective study (7/89-7/99) of patients of four suburban communities during two study periods: (1) police first response and advanced life support (ALS) care (No-AED) and; (2) AED equipped police first response (P-AED) with subsequent ALS care. Using the perspective of the communities, we obtained costs of AED program from police agencies. We estimated cost/life saved and cost/year lives saved using decreased time to VF shock by EMS. We performed a sensitivity analysis for estimates of potential benefit using estimated improved survival as a result of decreased EMS response interval and obtained survival data. We used literature-based estimates of life expectancy after cardiac arrest survival to estimate cost/year life saved. We used student's t-test and chi(2) to estimate differences between groups. RESULTS: During the 10-year study period 208 patients met study criteria; (81 No-AED, 128 P-AED). The two groups were not different by patient age, ALS response interval, percent in VF, percent witnessed (WIT), or arrest location. Interval to first defibrillator equipped EMS vehicle arrival was less in the P-AED group (2.0 vs. 5.4 min, P<0.001) as was the interval from the emergency (911) call to first VF shock (6.6 vs. 8.4 min, P=0.02). Survival to DC was not statistically different with P-AED (11.9 vs. 9.9%, P=0.66) but this study was not powered to detect a difference. Estimated cost per life saved with P-AED varied from $23542 to $70342 and cost per year life saved ranged from $1582 to $16060. CONCLUSION: Police AED appears to be a cost-effective intervention in these suburban communities which have relatively rapid EMS response intervals.

Aged↗
PubMed2002

Painful discrimination: the differential use of analgesia in isolated lower limb injuries.

Our primary objective was to compare use of analgesia for patients with and without fracture as a result of isolated lower extremity trauma, in the emergency department (ED). Our secondary objective was to compare the analgesic practices of emergency physicians (EPs) with that of physician assistants (PAs). We performed a prospective, blinded cohort study with the presence of fracture as the risk factor and provision of any pain medication while in the ED as the primary outcome. Included in the study were all patients who presented to a 90,000 visit suburban teaching hospital with an isolated lower extremity injury who received a radiograph of the foot or ankle over a 9-week period. We excluded patients without trauma, with multiple trauma, admitted, or seen by one of the investigators. Patients admitted and those with multiple trauma were excluded because these patients had contacts with multiple physicians and it is unlikely they would be able to differentiate which physician prescribed medication and if they were emergency personnel. We defined analgesia as any pain medication at any dose. One investigator preformed follow-up interviews using a standardized questionnaire 3 days after the visit. Patients expressed their recollection of their degree of pain using a verbal analog scale of 1 to 10. We report crude and adjusted odds ratios (OR). Of 516 consecutive patients, 111 met exclusion criteria and 3 had incomplete data. Of the remaining 405, we contacted 384 (95%) in an average of 3 +/- 1 days. Patients with and without fractures recalled their initial degree of pain similarly, with the mean initial pain scores on the verbal analog scale of 6.6 +/- 2.5 versus 6.8 +/- 2.1 respectively. Patients with a fracture were more likely to receive pain medication while in the ED (23% v 15% P =.047, OR 1.75 (CI 95% 1.02, 2.99). EPs gave some form of ED analgesia to 29% of patients, as compared with 10% of patients seen by PAs (OR = 3.58 CI 95% 2.05, 6.24). EPs provided a prescription to 44% of patients versus 21% of patients seen by PAs (OR = 2.91 CI 95% 1.85, 4.57). Our estimated adjusted ORs for providing analgesia in the ED were: fracture = 2.0 (CI 95% 1.13, 3.58); EP: 3.52 (CI 95% 1.98, 2.99); and for every additional point on the verbal pain scale: 1.28 (CI 95% 1.11, 1.48). Patients with fracture were more likely to receive pain, despite reporting identical degree of pain. EPs were more likely to provide analgesia than PAs.

Adolescent↗
PubMed2002

Criteria for the safe use of D-dimer testing in emergency department patients with suspected pulmonary embolism: a multicenter US study.

STUDY OBJECTIVE: We derive a decision rule to partition emergency department patients with suspected pulmonary embolism (PE) into a small, high-risk group (>40% pretest probability) that is unsafe for D -dimer testing and a larger group that is safe to have PE ruled out with either a whole-blood D -dimer plus alveolar deadspace measurement or a quantitative D -dimer assay. METHODS: Nine hundred thirty-four patients with suspected PE were studied at 7 urban EDs in the United States. Patients were prospectively interviewed and examined for recognized symptoms, signs, and risk factors associated with PE. These data were collected before standard objective imaging for PE. Selected variables were analyzed by multivariate logistic analysis to determine factors associated with PE (P <.05). A decision rule was then constructed to categorize approximately 80% of ED patients as safe for D -dimer testing. RESULTS: Pretest prevalence of PE was 19.4% (181/934; 95% confidence interval [CI] 16.3% to 21.7%). Six variables found to be significant on multivariate analysis were used to construct the decision rule. Unsafe patients had either a shock index (heart rate/systolic blood pressure) more than 1.0 or age older than 50 years, together with any one of the following conditions: unexplained hypoxemia (SaO (2) <95%; no prior lung disease), unilateral leg swelling, recent major surgery, or hemoptysis. These criteria were met by 197 (21.0%) of 934 patients, and 83 of 197 (42.1%; 95% CI 35.3% to 49.6%) patients had PE. Exclusion of these 197 unsafe patients significantly decreased the probability of PE in the remaining 737 (79.0%) safe patients to 13.3% (95% CI 10.9% to 15.9%). CONCLUSION: Simple clinical criteria can permit safe D -dimer testing in the majority of ED patients with suspected PE. These criteria warrant prospective validation.

Adult↗
PubMed2002

An emergency department observation unit protocol for acute-onset atrial fibrillation is feasible.

STUDY OBJECTIVE: We sought to describe the feasibility of an emergency department observation unit (EDOU) treatment protocol for the management of uncomplicated acute-onset atrial fibrillation (AAF). METHODS: This descriptive case series took place at a major suburban, university-affiliated teaching hospital. Patients were prospectively enrolled in an EDOU treatment protocol if they had uncomplicated AAF that failed initial ED attempts to convert to sinus rhythm. In the EDOU, patients underwent ECG monitoring, serial creatine kianse MB measurements, and further rate control with optional electrical cardioversion. Primary outcomes measured were EDOU rate of conversion to sinus rhythm, rate of discharge home, length of stay, positive diagnostic outcomes, complications of AAF, and 7-day return visits. RESULTS: Sixty-seven patients were studied. Patients were symptomatic for a median of 4.0 hours, had mean initial ED pulse rates of 137+/-23 beats/min, and spent 4.7+/-2.2 hours in the ED before transfer to the EDOU. While in the EDOU, 55 (82%) patients converted to sinus rhythm. Five (7%) patients were admitted because of positive test results: 2 for myocardial infarction, 2 for fever, and 1 for ventricular tachycardia. Twelve (18%) patients remained in atrial fibrillation, with 9 admitted and 3 discharged. Overall, 81% of patients were discharged in 11.8+/-7.0 hours, and 19% were admitted after 17.6+/-9.5 hours of observation. Three discharged patients returned within 7 days, 2 for uncomplicated recurrent AAF and 1 for chest pain subsequently found to be noncardiac in origin. There were no major complications attributable to the EDOU protocol. CONCLUSION: Selected patients with AAF for whom initial ED management fails can subsequently be managed in an EDOU with a high short-term conversion and discharge rate.

Acute Disease↗
PubMed2002

Reliability of assigning correct current procedural terminology-4 E/M codes.

STUDY OBJECTIVES: We determine the degree of interagency and intra-agency agreement on Current Procedural Terminology-4 (CPT-4) coding levels for emergency department medical records. We hypothesized that the level of agreement among coding agencies would be poor, but the distribution of codes would be similar and not significantly different. METHODS: We performed a prospective observational study consisting of 3 separate randomized, blinded trials: 2 interagency comparisons and 1 intra-agency comparison. The setting was 2 suburban academic EDs. In the 2 interagency audits, 4 coding agencies were used. In the intra-agency comparison, we used 5 individual coders from within our own internal agency. The main outcome measures were the level of agreement not due to chance estimated with the multiple-rater weighted kappa statistic and the Kendall tau-b. We measured the distribution of codes by agency or by individual coders with the chi(2) test. RESULTS: Our sample for the 2 interagency audits consisted of 194 and 195 records, respectively. We observed poor agreement in the level of coding assigned to individual charts among the 4 coding agencies, with kappa values of 0.28 (95% confidence interval [CI] 0.275 to 0.285) and 0.287 (95% CI 0.283 to 0.291). Our intra-agency comparison consisted of 100 records. The agreement in the intra-agency review was significantly better but still fair (kappa=0.436; 95% CI 0.428 to 0.444). The distribution of CPT-4 codes was significantly different for all 3 comparisons (P <.001). CONCLUSION: For our patient population, group of physicians, and methods of documentation, we identified poor-to-fair agreement in coding of emergency charts between coding agencies. Only fair agreement was measured in the intra-agency sample. The distribution of assigned CPT-4 codes was significantly different in each comparison. These findings have important financial and legal implications regarding the reliability of coding methods.

Centers for Medicare and Medicaid Services, U.S.↗