bluuebunny/crossref_metadata_2025 huggingface dataset:
Glucagon Use for Esophageal Coin Dislodgment in Children: A Prospective, Double‐blind, Placebo‐controlled Trial
Authors: Mehta Devendra I. , Attia Magdy W. , Quintana Eileen C. , Cronan Kathleen M.
Published: January 2008

Abstract. Objective: Prospective evaluation of the use of glucagon in dislodgment of impacted esophageal coins in children. Methods: This was a double‐blind, placebo‐controlled study with an open‐label second phase in children 1 to 8 years of age who presented to a pediatric emergency department with a radiographically confirmed single esophageal coin impaction. One milligram of glucagon or placebo was given intravenously in double‐blinded fashion. Patients were placed in an upright position and asked to drink 2‐3 ounces of water. A repeat radiograph was obtained to check coin position in 30‐60 minutes. Patients who did not respond were given 1 mg of open‐label glucagon intravenously. The glucagon and placebo groups were compared. Results: Fourteen patients were enrolled in the study (the predetermined sample size was not pursued due to inefficacy). Nine patients were in the glucagon group, and five were in the placebo group. Six patients received an additional open‐label glucagon dose. The two groups were not different in age (mean, 5.5 years and 4.5 years, respectively), coin position, time between ingestion and presentation (p = 0.45), or time between treatment and repeat radiograph (p = 0.29). In patients who received glucagon, two of 15 (15%) passed the coin into the stomach. In the placebo group, three of five (60%) passed the coin, an inversely significant ratio. Five of six patients who received open‐label glucagon were from the initial glucagon group. There were no responders among patients in this group. Conclusions: Glucagon does not appear to be effective in the dislodgment of esophageal coins in children.
Central Line Mechanical Complication Rate in Emergency Medicine Patients
Authors: Steele Robert , Irvin Charlene Babcock
Published: January 2008

Abstract. Central line (CL) placement in the emergency department (ED) is a common practice. Previously published small‐scale studies have quoted mechanical complication rates in emergency medicine patients of 10‐15%. Objective: To determine the mechanical complication rate of central venous catheterization in a large (65,000 visits/year) academic urban ED. Methods: This was a retrospective review of all ED‐placed CLs over a three‐year period from May 1995 to May 1998. Data were collected as part of a monthly quality assurance project and analyzed using Fisher's exact test (significance = p < 0.05). Central lines were defined as subclavian, internal jugular, femoral, and interosseous lines. Mechanical complication was defined as a pneumothorax, hematoma, line misplacement, or hemothorax. Results: There were 22 complications of a total of 643 CLs placed [complication rate 3.4% (95% CI = 1.9% to 4.8%)]. The complication rate for patients with a confirmatory chest x‐ray receiving a subclavian or internal jugular CL (excluding all patients who died prior to x‐ray evaluation of CL) was 6.2% (22/355) (95% CI = 3.9% to 9.3%). There were 402 (63%) CLs placed during a code with a complication rate of 2.2% (95% CI = 1.0% to 4.2%), 79% (317/402) medical and 21% (85/402) trauma codes. Thirty‐seven percent (241) of the CLs were placed on an “elective urgent” basis. Residents placed the majority of CLs (567/643), with a complication rate of 3%. There was no statistically significant difference in complication rates based on level of resident training. Conclusions: The CL mechanical complication rate in the ED at this institution is 3.4%. This is substantially lower than previously reported mechanical complication rates.
Cocaine, Ethanol, and Cocaethylene Cardiotoxity in an Animal Model of Cocaine and Ethanol Abuse
Authors: Wilson Lance D. , Jeromin Jennifer , Garvey Lee , Dorbandt Allison
Published: January 2008

Abstract.Objectives:Simultaneous abuse of cocaine and ethanol affects 12 million Americans annually. In combination, these substances are substantially more toxic than either drug alone. Their combined cardiac toxicity may be due to independent effects of each drug; however, they may also be due to cocaethylene (CE), a cocaine metabolite formed only in the presence of ethanol. The purpose of this study was to delineate the role of CE in the combined cardiotoxicity of cocaine and ethanol in a model simulating their abuse.Methods:Twenty‐three dogs were randomized to receive either 1) three intravenous (IV) boluses of cocaine 7.5 mg/kg with ethanol (1 g/kg) as an IV infusion (C+E,n= 8), 2) three cocaine boluses only (C,n= 6), 3) ethanol infusion only (E,n= 5), or 4) placebo boluses and infusion (n= 4). Hemodynamic measurements, electrocardiograms, and serum drug concentrations were obtained at baseline, and then at fixed time intervals after each drug was administered.Results:Two of eight dogs in the C+E group experienced cardiovascular collapse. The most dramatic hemodynamic changes occurred after each cocaine bolus in the C+E and C only groups; however, persistent hemodynamic changes occurred in the C+E group. Peak CE levels were associated with a 45% (SD ± 22%, 95% CI = 22% to 69%) decrease in cardiac output (p < 0.05), a 56% (SD ± 23%, 95% CI = 32% to 80%) decrease in dP/dtmax(p <.006), and a 23% (SD ± 15%, 95% CI = 7% to 49%) decrease in SVO2(p < 0.025). Ventricular arrhythmias were primarily observed in the C+E group, in which four of eight dogs experienced ventricular tachycardia.Conclusions:Cocaine and ethanol in combination were more toxic than either substance alone. Co‐administration resulted in prolonged cardiac toxicity and was dysrhythmogenic. Peak serum cocaethylene concentrations were associated with prolonged myocardial depression.
Modifying a Standard Industry Clinical Trial Consent Form Improves Patient Information Retention as Part of the Informed Consent Process
Authors: Dresden Graham M. , Levitt M. Andrew
Published: January 2008

Abstract. Objective: Informed consent is a required part of clinical research. Industry consent forms may be complex and difficult to understand. A comparison was performed between a standard, industry consent form (IF) and a modified, shortened version of the same form (MF) to determine which allows the patient to retain more information in the immediate postconsent period. Methods: This was a prospective, randomized study performed in an urban, county teaching emergency department (ED). A convenience sample (based on the availability of one of two research assistants being present in the ED) of 100 patients with a history of asthma seen in the ED were enrolled. After reading the consent form, 50 MF and 50 IF patients were given a postconsent test to determine how much information was retained. Mean differences in test scores between the IF and MF were determined. Results: The population had a mean age (±SD) of 39.4 ± 12.1 years (range 18‐80); 52% were female. The overall score for the study population was 9.6 (±2.0), range 2‐12 (maximum 12). The MF score was 10.6 (±1.4) vs the IF score of 8.6 (±2.1); mean difference = 2.0 (95% CI = 1.3 to 2.7, p < 0.0001). The MF group had significantly more correct answers than the IF group with the following questions (MF%, IF%; mean difference in proportions with 95% CIs): purpose (96, 70; 26, 95% CI = 12 to 40); randomization (78, 44; 34, 95% CI = 16 to 52); study duration (94, 70; 24, 95% CI = 10 to 38); risks (92, 74; 18, 95% CI = 4 to 32); benefits (94, 78; 16, 95% CI = 3 to 29); alternative treatments (88, 70; 18, 95% CI = 2 to 34); confidentiality (98, 88; 10, 95% CI = 0.2 to 20); and voluntary participation (74, 54; 20, 95% CI = 2 to 38). Adverse event compensation had the poorest correct rate (54, 38; 13, 95% CI = ‐6 to 32). Subsequently, after taking the postconsent test, 98% wrote that they read the entire MF, while only 68% wrote that they read the entire IF (mean difference in proportions 30%, 95% CI = 17% to 43%). Conclusions: Compared with an industry consent form, a shortened version, focusing on Food and Drug Administration and Department of Health and Human Services informed consent guidelines, allowed patients to retain more information in the immediate postconsent period.
Manual of Emergency Airway Management
Authors: Lynch E. Lea
Published: January 2008

Abstract. By Ron M. Walls, Robert C. Luten, Michael F. Murphy, and Robert E. Schneider. Philadelphia: Lippincott Williams & Wilkins, 2000; 256 pp; $42.95 (softcover).
Rapid Development of Brain Hypothermia Using Femoral—Carotid Bypass
Authors: Mori Kazuhisa , Saito Jota , Kurata Yoshiaki , Takeyama Yoshihiro , Itoh Yasushi , Kaneko Masamitsu , Asai Yasufumi , Renzi Francis P. , Dickson Eric W.
Published: January 2008

Abstract. Objectives: Advances in the field of cardiopulmonary resuscitation have led to an increasing number of patients initially surviving sudden cardiac arrest. Unfortunately, most of these patients do not recover from the resultant anoxic brain insult. Several animal and human trials have suggested that post‐resuscitative brain hypothermia may improve neurologic recovery after cardiopulmonary arrest. Present cooling methods are slow, induce only brain surface cooling, or result in systemic hypothermia. The authors tested the hypothesis that unilateral hypothermic carotid bypass would induce bilateral brain cooling without evoking systemic hypothermia or hemodynamic instability. Methods: Anesthetized, ventilated common swine (n= 6, 24‐37 kg) underwent right femoral and carotid artery bypass cannulation. Central and peripheral hemodynamic parameters were recorded every 2 minutes throughout the procedure. Thermodynamic parameters included bilateral frontal lobe, bilateral nasopharyngeal, pulmonary artery, and rectal temperatures. Hypothermic femoral—carotid bypass was accomplished by drawing blood from the right femoral artery, cooling it to 24°C, and returning it to the right carotid artery at a flow rate of 5 mL/kg/min for 30 minutes. Results: With initiation of cooling, brain temperatures dropped rapidly from baseline of 37.2°C to 30.6°C (right frontal lobe) and 33.1°C (left frontal lobe) at 30 minutes. Pulmonary artery and rectal temperatures also decreased, but never reached mild hypothermic levels (34°C). There was no significant change in any hemodynamic parameters during brain cooling. Conclusions: Femoral—carotid hypothermic bypass rapidly induced a state of selective brain hypothermia without causing systemic hypothermia or hemodynamic instability.
Intranasal Lidocaine for the Treatment of Migraine Headache: A Randomized, Controlled Trial
Authors: Blanda Michelle , Rench Thomas , Gerson Lowell W. , Weigand John V.
Published: January 2008

Abstract. Objective: To evaluate the effect of intranasal lidocaine for immediate relief (5 minutes) of migraine headache pain. Methods: A randomized, double‐blind, placebo‐controlled clinical trial at two university‐affiliated community teaching hospitals enrolled patients 18‐50 years old with migraine headache as defined by the International Headache Society. Patients who were pregnant, lactating, known to abuse alcohol or drugs, or allergic to one of the study drugs, those who used analgesics within two hours, or those with a first headache were excluded. Statistical significance was assessed by using chi‐square or Fisher's exact test for categorical variables and Student's t‐test for continuous variables. Patients rated their pain on a 10‐centimeter visual analog scale (VAS) prior to drug administration and at 5, 10, 15, 20, and 30 minutes after the initial dose. Medication was either 1 mL of 4% lidocaine or normal saline (placebo) intranasally in split doses 2 minutes apart and intravenous prochlorperazine. Medications were packaged so physicians and patients were unaware of the contents. Successful pain relief was achieved if there was a 50% reduction in pain score or a score below 2.5 cm on the VAS. Results: Twenty‐seven patients received lidocaine and 22 placebo. No significant difference was observed between groups in initial pain scores, 8.4 (95% CI = 7.8 to 9.0) lidocaine and 8.6 (95% CI = 8.0 to 9.2) placebo (p = 0.75). Two of 27 patients (7.4%, 95% CI = 0.8, 24.3) in the lidocaine group and three of 22 patients (13.6%, 95% CI = 2.8 to 34.9) in the placebo group had immediate successful pain relief (p = 0.47), with average pain scores of 6.9 (95% CI = 5.9 to 7.8) and 7.0 (95% CI = 5.8 to 8.2), respectively. No difference in pain relief was detected at subsequent measurements. Conclusion: There was no evidence that intranasal lidocaine provided rapid relief for migraine headache pain in the emergency department setting.
Ultrasound‐guided Breast Abscess Aspiration in a Difficult Case
Authors: Blaivas Michael
Published: January 2008

Abstract. Although ultrasound guidance is occasionally used for abscess detection and aspiration by our radiology colleagues, this is still a very uncommon application in the emergency department (ED). A case is presented of a patient with a difficult‐to‐drain, recurrent breast abscess. The consulting surgeon was unable to localize the abscess after 15 attempts at aspiration in the ED and requested ultrasound guidance from the attending emergency physician for the procedure. Drainage of the abscess was successfully completed in one attempt with real‐time visualization and guidance of the needle. The consulting surgeon requested that ultrasound be available at the patient's follow‐up visit to the ED.
Smallpox Vaccination: A National Survey of Emergency Health Care Providers
Authors: Everett Worth W. , Coffin Susan E. , Zaoutis Theoklis , Halpern Scott D. , Strom Brian L.
Published: January 2008

Concerns about bioterrorism have prompted a national voluntary smallpox (SP) vaccination program in the United States. Although emergency health care providers are among the first targeted for vaccination, little is known about how these providers view the risks and benefits of SP vaccination. Objectives: To assess the willingness of emergency health care personnel to receive pre‐event SP vaccination prior to the start of the national program. Methods: The authors conducted a national cross‐sectional, anonymous survey of 1,701 emergency physicians, nurses, and mid‐level practitioners working full time in 13 adult and pediatric academic emergency departments in large U.S. cities in November and December 2002. The main outcome measure was willingness to be vaccinated against SP. Secondary outcomes included the prevalence of self‐reported contraindications, and reasons for and against vaccination. Results: 732 emergency health care providers returned questionnaires (response rate 43%). Overall, 73% (95% CI = 66% to 80%) were willing to receive pre‐event SP vaccination. 18% (95% CI = 14% to 23%) reported contraindications to vaccination, and 50% (95% CI = 39% to 61%) of these providers were willing to receive pre‐event SP vaccination. Self‐protection (72%) was the most common reason cited for desiring vaccination against SP; concern about vaccine‐related adverse events (54%) was the most common reason cited for not wanting immunization. Conclusions: Most emergency health care providers express a willingness to receive pre‐event SP immunization; self‐protection is a principal motivating reason. A subset of health care providers, however, may place themselves at increased risk by desiring vaccination despite contraindications.
Bench to Bedside: Electrophysiologic and Clinical Principles of Noninvasive Hemodynamic Monitoring Using Impedance Cardiography
Authors: Summers Richard L. , Shoemaker William C. , Peacock W. Franklin , Ander Douglas S. , Coleman Thomas G.
Published: January 2008

The evaluation of the hemodynamic state of the severely ill patient is a common problem in emergency medicine. While conventional vital signs offer some insight into delineating the circulatory pathophysiology, it is often impossible to determine the true clinical state from an analysis of blood pressure and heart rate alone. Cardiac output measurements by thermodilution have been the criterion standard for the evaluation of hemodynamics. However, this technology is invasive, expensive, time‐consuming, and impractical for most emergency department environments. Impedance cardiography (ICG) is a noninvasive method of obtaining continuous measurements of hemodynamic data such as cardiac output that requires little technical expertise. ICG technology was first developed by NASA in the 1960s and is based on the idea that the human thorax is electrically a nonhomogeneous, bulk conductor. Variation in the impedance to flow of a high‐frequency, low‐magnitude alternating current across the thorax results in the generation of a measured waveform from which stroke volume can be calculated by a modification of the pulse contour method. To adequately judge the possible role of this technology in the practice of emergency medicine, it is important to have a sufficient understanding of the basic scientific principles involved as well as the clinical validity and limitations of the technique.
Magnesium–Aluminum Hydroxide Suspension for the Treatment of Dermal Capsaicin Exposures
Authors: Lee David C. , Ryan James R.
Published: January 2008

Objectives: To determine whether magnesium–aluminum‐hydroxide–simethicone suspension (MgAl) is an effective treatment for dermal capsaicin exposures. Methods: The authors performed a double‐blind, randomized, controlled, pilot study comparing the effect of MgAl with that of saline in the treatment of dermal capsaicin exposures. Ten volunteers were sprayed with a commercial defensive spray containing 10% capsaicin on the flexor surface of both forearms. A dressing embedded with MgAl (Maalox) suspension was randomly applied to one arm and a saline‐embedded dressing was applied to the other arm. Pain was assessed on a 10‐cm visual analog scale at 0, 10, 20, 30, 60, 90, and 120 minutes. Results: Mean pain scores were significantly lower in the MgAl group as compared with the saline (S) group at 10, 20, and 30 minutes. Differences in pain scores were not statistically significant at times 60, 90, and 120 minutes. Conclusions: During the initial 30 minutes of treatment, there was a statistically significant decrease in pain scores with MgAl as compared with saline treatments. Although the difference in means may have questionable clinical significance, MgAl is cheap and readily available, and has minimal side effects. Thus, MgAl may be an appropriate treatment for dermal capsaicin exposure.
A Cost–Effectiveness Analysis of Treatment Strategies for Acute Uncomplicated Pyelonephritis in Women
Authors: Yen Zui‐Shen , Davis Mark A. , Chen Shyr‐Chyr , Chen Wen‐Jone
Published: January 2008

At least 250,000 episodes of acute uncomplicated pyelonephritis are treated annually in the emergency department (ED). Trimethoprim–sulfamethoxazole (TMP‐SMX) and norfloxacin have both been used as treatments for acute uncomplicated pyelonephritis. Objectives: To investigate the cost–effectiveness of two outpatient treatment strategies, TMP‐SMX and norfloxacin, for acute uncomplicated pyelonephritis in adult women between the ages of 18 and 65 years. Methods: Common principles of cost–effectiveness analysis were used for this evaluation. The authors developed a decision tree to estimate the costs and effectiveness of two different treatment strategies: TMP‐SMX 160/800 mg twice per day for 10 days and norfloxacin 400 mg twice per day for 10 days. The time frame of the decision tree was 11 days. Outcomes were expressed in U.S. dollars, quality‐adjusted life‐days (QALDs), and dollars per QALD. Sensitivity analyses were performed on most variables. Results: Norfloxacin is more effective and less costly than the alternative, TMP‐SMX. Norfloxacin treatment will save $195.85 per patient, resulting in an aggregate saving of more than $40 million annually. Patients are expected to enjoy a better quality of life with an incremental 0.0601 QALD per patient, if they are treated with norfloxacin. These results are robust across a wide range of probabilities and costs. Conclusions: In this analysis, norfloxacin 400 mg twice a day was a more cost‐effective treatment than TMP/SMX 160/800 mg twice a day for women with pyelonephritis.
Teaching Techniques in the Clinical Setting: the Emergency Medicine Perspective
Authors: Wald David A.
Published: January 2008

The emergency department (ED) provides a unique educational experience that is distinct from both inpatient and ambulatory care settings. Because of the high acuity, interesting pathology, and rapid patient turnover, the ED is an ideal location to train medical students. Numerous teaching opportunities exist within the domain of the ED. In the preclinical years, the ED setting provides medical students with an introduction to clinical medicine and may serve as a venue for teaching basic history and physical examination skills. In the clinical years, medical students are exposed to a wide range of undifferentiated patients. Besides common medical and surgical complaints, many medical students will encounter clinical scenarios that they otherwise would have little direct contact with. Encounters such as the acutely poisoned or intoxicated patient, environmental emergencies, interaction with out‐of‐hospital providers, and patients requiring emergency procedures are just a few situations that make emergency medicine a distinct clinical specialty. These and other student–patient encounters can provide the teaching physician an opportunity to focus case‐based teaching on a number of elements including complaint‐directed medical interviewing and physical examination skills, development of case‐specific differential diagnosis, diagnostic evaluation, implementation of patient management plans, and patient disposition. In this review article, the authors discuss various ways to approach and improve clinical teaching of medical students, including: opportunities for teaching in the ED, teaching procedural skills, student case presentations, clinical teaching styles, qualities of an effective clinical teacher, and barriers to effective clinical teaching.
Xanthochromia is not pathognomonic for subarachnoid hemorrhage
Authors: Graves Peter , Sidman Robert
Published: January 2008

Objective: To test the hypothesis that xanthochromia may be observed in traumatic lumbar puncture (LP). Xanthochromia, the yellow discoloration of cerebrospinal fluid (CSF) caused by hemoglobin catabolism, is classically thought to arise within several hours after subarachnoid hemorrhage (SAH). The presence of xanthochromic supernatant is often used to distinguish the elevated red blood cell (RBC) count observed in the CSF of SAH from the elevated RBC count observed after traumatic LP. Methods: The authors developed a model of traumatic LP by adding whole blood to pigment‐free CSF to obtain RBC concentrations of 0, 5,000, 10,000, 20,000, 30,000, and 40,000 RBC/μL. Supernatant from centrifuged samples was assessed for xanthochromia by spectrophotometry. Xanthochromia was considered present if the absorption followed a characteristic oxyhemoglobin curve with a maximal absorption greater than 0.023 at 415 nm. Results: Samples with at least 30,000 RBC/μL demonstrated xanthochromia immediately. Samples with 20,000 RBC/μL demonstrated xanthochromia within one hour, and samples with 10,000 RBC/μL or less, within two hours. Conclusions: Cerebrospinal fluid xanthochromia may be observed within two hours after traumatic LP and sooner in samples with greater than 10,000 RBC/μL. Conversely, xanthochromia in traumatic LP with less than 5,000 RBC warrants further investigation for SAH. When the CSF RBC count is elevated above 10,000 RBC/μL, or the time between sample acquisition and analysis is prolonged, the clinician should not rely on xanthochromia to confirm SAH.
Evolution of an Emergency Department Screening Questionnaire for Severe Acute Respiratory Syndrome
Authors: Foo Chik‐Loon , Tham Kum‐Ying , Seow Eillyne
Published: January 2008

Objectives: To describe the screening tool that was used to screen for severe acute respiratory syndrome (SARS), the three revisions that were made, and the factors that led to these revisions. On March 13, 2003, on receiving notification of an outbreak of atypical pneumonia, nurses from the study emergency department (ED) started screening patients for the disease that became known as SARS. Methods: The ED nurses started with a simple screening tool that was incorporated into triage. The screening tool was later revised into a questionnaire. An outdoor screening station was set up and patients were subsequently screened before triage. After the patients were screened, they were assigned to different risk areas, where triage and treatment were rendered. Two further revisions were made to the questionnaire. Results: From March 13 to May 31, 11,457 patients were screened. Version One of the screening questionnaire was used to screen 72 patients from March 13 to 17, Version Two screened 93 patients from March 18 to 21, Version Three screened 2,909 patients from March 22 to April 8, and Version Four screened 8,383 patients from April 9 to May 31. There was a significant (p < 0.05) downward trend in the proportion of admissions. Among those discharged from the ED, 0.28% reattended and were later confirmed to have SARS. Conclusions: The screening tool underwent three major revisions in response to new information. By keeping it relatively simple, user‐friendly, and regularly updated, nurses were able to screen patients rapidly. Risk categorization ensured that no cross‐infection occurred among patients and that no one contracted SARS in the ED.
Needle Thoracostomy: Implications of Computed Tomography Chest Wall Thickness
Authors: Givens Melissa L. , Ayotte Karen , Manifold Craig
Published: January 2008

Objectives: To determine the length of catheter required to perform a needle thoracostomy, as determined by chest wall thickness, to treat the majority of patients presenting to the emergency department (ED) with a potential tension pneumothorax. Methods: A convenience sample of 111 computed tomography (CT) scans of the chest in trauma and medical resuscitation patients at a military Level 1 trauma center in San Antonio, Texas, was pooled, and the chest wall thickness was measured at the second intercostal space, midclavicular line, to the nearest 0.1 cm. Results: The mean chest wall thickness in the patients studied averaged 4.24 cm (95% confidence interval [CI] = 3.97 to 4.52). Nearly one fourth (25) of the study patients had a chest wall thicker than 5 cm. Women, on average, have thicker chest walls than men (4.90 for women; 4.16 for men; p = 0.022).Conclusions: In this study, a catheter length of 5 cm would reliably penetrate the pleural space of only 75% of patients. A longer catheter should be considered, especially in women.
Diversity of Tn
1546
and Its Role in the Dissemination of Vancomycin-Resistant Enterococci in Portugal
Authors: Novais Carla , Freitas Ana R. , Sousa João C. , Baquero Fernando , Coque Teresa M. , Peixe Luísa V.
Published: January 2008

We characterized the molecular diversity of
vanA
vancomycin-resistant enterococci (VRE; 176 isolates/87 pulsed-field gel electrophoresis types) from different sources and cities in Portugal (1996 to 2004): (i) food animals (FA;
n
= 38 isolates out of 31 samples), hospitalized humans (HH;
n
= 101/101), healthy human volunteers (HV;
n
= 7/4), and environmental sources (
n
= 30/10). Some strains were isolated from different hosts and persistently recovered for years. Twenty-four Tn
1546
variants were identified, all located on plasmids (30 to 250 kb). Some Tn
1546
variants were associated with specific sources such as FA (3 types), HH (11 types), or HV (1 type), while others were recovered from isolates of different origins (8 types). Polymorphisms in the central
vanRSHA
region of Tn
1546
were scarcely detected, while alterations upstream of
vanR
and downstream of
vanA
were frequently identified involving mutations (
vanS
and
vanX
), deletions (
vanY
), insertions (IS
1216V
, IS
Ef1
, and IS
19
; sequences with or without homology with others available in GenBank databases), and different genetic rearrangements. Most Tn
1546
variants contained IS
1216V
(14 types) or IS
Ef1
(6 types). IS
1216V
was found alone or associated with an IS
3
-like element at different orientations and positions in Tn
1546
from human, animal, and environmental samples. IS
Ef1
was located within
vanX
-
vanY
region at nucleotide 9044 of Tn
1546
variants mostly associated with clinical isolates, suggesting a common genetic platform. IS
19
was observed within the
vanX
-
vanY
region in one Tn
1546
variant from poultry. Recent spread of VRE in Portugal reflects a complex epidemiology involving both clonal spread and plasmid dissemination containing a variety of Tn
1546
types. Apparent Tn
1546
heterogeneity among enterococci from human, animal, and environmental sources might reflect frequent genetic exchange events and evolution of particular widely disseminated genetic elements.
Relationship between Antibiotic Use and Incidence of MexXY-OprM Overproducers among Clinical Isolates of
Pseudomonas aeruginosa
Authors: Hocquet Didier , Muller Arno , Blanc Karine , Plésiat Patrick , Talon Daniel , Monnet Dominique Louis , Bertrand Xavier
Published: January 2008

In a university hospital, time-series analysis revealed a significant relationship between antibiotic (aminoglycoside, fluoroquinolone, and cefepime) use and incidence of MexXY-OprM-overproducing
Pseudomonas aeruginosa
. In vitro experiments confirm that such mutants were readily selected from both PAO1 and clinical strains when grown in the presence of these antibiotics.
Increase of Virulence and Its Phenotypic Traits in Drug-Resistant Strains of
Candida albicans
Authors: Angiolella Letizia , Stringaro Anna Rita , De Bernardis Flavia , Posteraro Brunella , Bonito Mariantonietta , Toccacieli Laura , Torosantucci Antonella , Colone Marisa , Sanguinetti Maurizio , Cassone Antonio , Palamara Anna Teresa
Published: January 2008

There is concern about the rise of antifungal drug resistance, but little is known about comparative biological properties and pathogenicity of drug-resistant strains. We generated fluconazole (FLC; CO23
RFLC
)- or micafungin (FK; CO23
RFK
)-resistant strains of
Candida albicans
by treating a FLC- and FK-susceptible strain of this fungus (CO23
S
) with stepwise-increasing concentrations of either drug. Molecular analyses showed that CO23
RFLC
had acquired markedly increased expression of the drug-resistance efflux pump encoded by the
MDR1
gene, whereas CO23
RFK
had a homozygous mutation in the
FSK1
gene. These genetic modifications did not alter to any extent the growth capacity of the drug-resistant strains in vitro, either at 28°C or at 37°C, but markedly increased their experimental pathogenicity in a systemic mouse infection model, as assessed by the overall mortality and target organ invasion. Interestingly, no apparent increase in the vaginopathic potential of the strains was observed with an estrogen-dependent rat vaginal infection. The increased pathogenicity of drug-resistant strains for systemic infection was associated with a number of biochemical and physiological changes, including (i) marked cellular alterations associated with a different expression and content of major cell wall polysaccharides, (ii) more rapid and extensive hypha formation in both liquid and solid media, and (iii) increased adherence to plastic and a propensity for biofilm formation. Overall, our data demonstrate that experimentally induced resistance to antifungal drugs, irrespective of drug family, can substantially divert
C. albicans
biology, affecting in particular biological properties of potential relevance for deep-seated candidiasis.
Antimicrobial Activities of Ceftaroline and ME1036 Tested against Clinical Strains of Community-Acquired Methicillin-Resistant
Staphylococcus aureus
Authors: Sader Helio S. , Fritsche Thomas R. , Jones Ronald N.
Published: January 2008

Two investigational anti-methicillin-resistant
Staphylococcus aureus
(anti-MRSA) β-lactams, ceftaroline (a cephalosporin) and ME1036 (a carbapenem), were subjected to susceptibility testing by reference broth microdilution methods using 152 strains of community-acquired MRSA from the United States (47 medical centers). Ceftaroline and ME1036 were 64- and >128-fold more potent than ceftriaxone, respectively. All isolates had the Panton-Valentine leukocidin genes and staphylococcal cassette chromosome
mec
type IV, while 67.8% of isolates displayed pulsed-field gel electrophoresis clonal type USA300-0114.
Plasmid-Borne
erm
(T) from Invasive, Macrolide-Resistant
Streptococcus pyogenes
Strains
Authors: Woodbury Robyn L. , Klammer Kathryn A. , Xiong Yang , Bailiff Timothy , Glennen Anita , Bartkus Joanne M. , Lynfield Ruth , Van Beneden Chris , Beall Bernard W.
Published: January 2008

Twenty-three isolates of group A streptococci (GAS) recovered from population-based invasive GAS surveillance in the United States were erythromycin resistant, inducibly clindamycin resistant, and lacked known macrolide resistance determinants. These 23 isolates, representing four different clones, contained a broad-host-range plasmid carrying the
erm
(T) methylase gene, which has not been detected in GAS previously.
Distribution and characterization of phototrophic bacteria isolated from the water of Bietri Bay (Ebrie Lagoon, Ivory Coast)
Authors: Caumette Pierre
Published: January 2008

Phototrophic bacteria were observed forming a brown layer, at the interface between aerobic and anaerobic waters, in a stratified tropical lagoon (Bietri Bay, 5°15′ N, 4 °W, Ivory Coast). Within the brown layer (3.2–4 m depth), a stratification of different genera was observed. In the upper part purple bacteria developed, whereas green and brown Chlorobiaceae abounded mostly in a lower layer (3.5–4 m depth). Among the purple bacteria, some species were isolated and identified as Rhodopseudomonas palustris, Chromatium violascens, Chr. vinosum, and Chr. gracile. The green and brown sulfur bacteria were related to Chlorobium vibrioforme and Chl. phaeobacteroides. Chlorobium phaeobacteroides was the most abundant organism in the whole brown layer as well as in the deepest layer. As the phototrophic bacteria isolated were able to grow at different salt concentrations, the stratification observed could be explained by the gradients of sulfide and light. As shown by experimental data, purple bacteria grew under microaerobic conditions and used light intensities higher than green and brown sulfur bacteria whose growths were highly dependent on strict anaerobic conditions. During the dry season, holomixis involved the disappearance of the brown layer. Some phototrophic bacteria were found in the oxygenated water column. However, only brown Chlorobium was isolated. Although this species was found in a microaerobic environment in Bietri Bay, it never grew under microaerobic conditions in the synthetic media. This bacterium (Chlorobium phaeobacteroides strain BI 28) was able to use thiosulfate, as did Chl. vibrioforme isolated from the brown layer.
Osmoregulation in Klebsiella pneumoniae: enhancement of anaerobic growth and nitrogen fixation under stress by proline betaine, γ-butyrobetaine, and other related compounds
Authors: Rudulier Daniel Le , Bernard Theophile , Goas Gabrielle , Hamelin Jack
Published: January 2008

Exogenous proline betaine (stachydrine or N-dimethylproline) or γ-butyrobetaine (γ-trimethylaminobutyrate), at a concentration as low as 1 mM, were found to stimulate the growth rate of Klebsiella pneumoniae, wild type M5A1, in media of inhibitory osmotic strength (0.8 M NaCl). Simultaneously, nitrogen fixation by whole cells, a process particularly sensitive to osmotic stress, was strongly enhanced by these compounds. However, in the absence of sodium chloride, both the growth and nitrogen fixation were not affected by the addition of the methylammonium derivatives in the medium. The sensitivity of the nitrogen fixation to osmotic stress was used as a bioassay to evaluate the potentiality of osmoprotective compound in relation to the number of methyl groups on the nitrogen atom of glycine, proline, and γ-aminobutyrate. Experiments with sarcosine (monomethylglycine), dimethylglycine, and glycine betaine (trimethylglycine), or experiments with mono- and di-methylproline or γ-mono-, γ-di-, γ-tri-methylaminobutyrate, indicated that the greatest stress tolerance was always obtained with the more N-methylated compounds.
Some properties of the endo-(1 → 4)-β-D-glucanase synthesized by the anaerobic cellulolytic rumen bacterium Ruminococcus albus
Authors: Wood Thomas M. , Wilson Catriona A.
Published: January 2008

The extracellular and cell-bound cellulase (CM-cellulase) elaborated by the rumen bacterium Ruminococcus albus SY3 in synthetic medium was an endo-(1 → 4)-β-glucanase in that (i) it produced a rapid fall in the degree of polymerisation (1900 → 300) of H3PO4-swollen cellulose, while causing only 0.5% hydrolysis, and (ii) it released large amounts of cellotriose and smaller amounts of cellotetraose from H3PO4-swollen cellulose. The enzyme appeared in a wide range of molecular weights, which varied according to the culture conditions, but nevertheless focused at pH 6.0–6.1 in all cases in a pH gradient supported in a polyacrylamide gel. Cell-bound enzyme, which was of very large molecular weight (> 1.5 × 106), was excluded from the polyacrylamide gel. Under certain conditions, cellulose swollen in H3PO4 was hydrolysed extensively, but highly ordered cellulosic substrates were poorly hydrolysed. The enzyme acted synergistically with an endwise-acting cellobiohydrolase from the fungus Trichoderma koningii in solubilizing a microcystalline wood α-cellulose preparation (Avicel): the same cooperation was not apparent when Avicel was swollen in H3PO4 or when cellulose in the form of cotton fibre was used.
Viable but nonrecoverable stage of Salmonella enteritidis in aquatic systems
Authors: Roszak D. B. , Grimes D. J. , Colwell R. R.
Published: January 2008

An environmental isolate (13-1BB) of Salmonella enteritidis serogroup C1 was inoculated into sterile Potomac River water microcosms to observe survival and culturability of the organism by employing acridine orange direct count, fluorescent antibody direct count, direct viable count, plate count on veal infusion agar and xylose lysine decarboxylase agar, and indirect enumeration by the most-probable-number method (MPN), using media selective for Salmonella. Loss of culturability on laboratory media was observed within 48 h. However, cultures could be "resuscitated" and cultured on solid media, following addition of nutrients to the microcosms. Cells, resuscitated 4 days after apparent "die-off" (0 colony-forming units (cfu)/mL) using plate count techniques, yielded numbers of cfu in the same order of magnitude as had been observed before the onset of nutrient limitation. Microscopic techniques for direct viable counting indicated that viability is maintained for as long as 60 days after depletion of nutrients, although attempts to culture these cells, by addition of nutrient, after 21 days yielded apparently sterile plates. Thus, longer periods of "dormancy" appear to require conditions other than simple nutrient addition for resumption of cell growth and division.
Protein synthesis in germinating Saccharomyces cerevisiae ascospores
Authors: Armstrong Robert L. , West Thomas P. , Magee Paul T.
Published: January 2008

The uptake and incorporation of macromolecular precursors in germinating Saccharomyces cerevisiae ascospores were investigated. Addition of cycloheximide at various times during germination revealed that protein synthesis can occur within 20 min after the spores are shifted to glucose-containing media. The time of initiation of uptake and incorporation of several amino acids differed; this can be attributed to differing amino acid pool levels in the spores, as well as differing transport activities. Two-dimensional gel electrophoresis of proteins labeled with [35S]methionine for various 20-min periods after germination began showed at least one protein whose synthesis begins well after the bulk of the proteins.
In vitro and in vivo pathologic effects of Vibrio parahaemolyticus on human epithelial cells
Authors: Merrell B. R. , Walker R. I. , Joseph S. W.
Published: January 2008

The initial interaction and adherence of Vibrio parahemolyticus to epithelial tissue culture cells, human buccal epithelial cells, and the ileal mucosa of mice were studied. Using scanning electron microscopy, adherent bacteria were observed only on degenerating human embryonic intestinal, HeLa, and buccal cells; healthy normal cells were devoid of bacteria. Sheared V. parahaemolyticus, i.e., lacking flagella, did not adhere to either normal or degenerating tissue cells. Neither ultraviolet-inactivated organisms nor cell-free culture supernate affected the epithelial cells. Similar findings were observed on the mucosa of the ileum in mice inoculated with V. parahaemolyticus. It appears that V. parahaemolyticus possesses a cytotoxic factor which alters epithelial cells. This factor appears to be closely associated with viable organisms and may be a functional element in the adherence process of flagellated V. parahaemolyticus to mammalian epithelial cells.
Escherichia coli growth on lactose requires cycling of β-galactosidase products into the medium
Authors: Huber R. E. , Hurlburt K. L.
Published: January 2008

Growth on lactose was found to be restricted in an Escherichia coli strain deficient in its ability to transport glucose and galactose. If the latter sugars were removed from the medium as they were being produced, a wild-type strain grew only poorly, while the transport-deficient strain did not grow at all. These results suggested that all of the products of β-galactosidase action on lactose are released into the medium before being metabolized. This contention was strongly supported by the finding that the appearance of products in the medium was equal to lactose disappearance at three limiting lactose concentrations and by an experiment which showed that essentially all of the label from added lactose ([1-14C]glucose) was found in the medium as glucose when chased with unlabelled lactose.
Synthesis of the bulkym-terphenyl phenol Ar*OH (Ar* = C6H3-2,6-Mes2, Mes = 2,4,6-trimethylphenyl) and the preparation and structural characterization of several of its metal complexes
Authors: Dickie Diane A , MacIntosh Ian S , Ino Daisuke D , He Qi , Labeodan Ojisamola A , Jennings Michael C , Schatte Gabriele , Walsby Charles J , Clyburne Jason A.C.
Published: January 2008

The bulky m-terphenyl phenol Ar*OH 1 (Ar* = C6H3-2,6-Mes2, Mes = 2,4,6-trimethylphenyl) was synthesized via the treatment of Ar*Li with nitrobenzene. The phenol 1 is prepared in modest to good yield using this method. Attempts were also made to prepare 1 through oxidation of the bulky boronic acid Ar*B(OH)2with Oxone®, but this reaction was not suitable for preparative-scale reactions. Side products of the reaction between Ar*Li and nitrobenzene were identified as Ar*[N(O)Ph] and [C6H5N(O)]2and were characterized by X-ray crystallography and EPR spectroscopy. A variety of main-group and transition-metal complexes of Ar*OH were prepared, namely Sn(OAr*)2, Ge(OAr*)2, [N(SiMe3)2]Ge(OAr*), [Me2Al(OAr*)]2, and Ti(NMe2)(OAr*)2. All compounds were characterized spectroscopically and most were studied by single-crystal X-ray diffraction as well.Key words: m-terphenyl, main-group compounds, X-ray crystallography, multinuclear NMR spectroscopy, EPR spectroscopy.
Evaluating some financial uncertainties of tree improvement using the capital asset pricing model and dominance analysis
Authors: Thomson Thomas A.
Published: January 2008

Although uncertainty considerations are of prime importance in capital budgeting, forestry investments are often evaluated without comparing their uncertainty level with their rates of return. This paper examines some financial uncertainties of a west coast Douglas-fir tree improvement program. Biophysical uncertainties such as amount of genetic gain or uncertainty of site quality are determined by apriori assumption to be nonmarket; thus, use of expected value adjusts for these risks. The market uncertainties of tree improvement are found to be reasonable, vis-à-vis other investments as sensitivity analysis shows that the financial risks were small, or the measured β was low. This paper concludes that the tree improvement investment is worthwhile, considering its risk as well as return.
The effect of wildfire on soil chemistry in four forest types in interior Alaska
Authors: Dyrness C. T. , Cleve K. Van , Levison J. D.
Published: January 2008

Soil chemical properties were studied after a wildfire in stands of white spruce (Piceaglauca (Moench) Voss), black spruce (Piceamariana (Mill.) B.S.P.), paper birch (Betulapapyrifera Marsh.), and quaking aspen (Populustremuloides Michx.). Samples of the forest floor and surface 5 cm of mineral soil were collected from burned sites and unburned controls and analyzed soon after the fire. With the exception of soil pH, effects of the fire on soil chemistry differed among the four forest types. Generally, amounts of exchangeable K, Ca, and Mg did not appreciably increase in the forest floor and surface mineral soil except in heavily burned areas in white spruce and black spruce. Fire reduced amounts of N by about 50% in white spruce, aspen, and birch forest floors. In black spruce, quantities of N were slightly higher in heavily burned locations. Forest floor C:N ratios were substantially lower in heavily burned locations in white spruce and black spruce than in unburned controls. Burning did not have a marked influence on supplies of available P in the forest floor, except in heavily burned black spruce, where average amounts were 12.50 g/m2 versus only 0.46 g/m2 in the control. Burning caused more moderate gains in available P in surface mineral soils under aspen and white spruce. We concluded that fire caused marked short-term changes in soil chemistry in the four forest types. How long these changes will persist is unknown.
Fire history in a Sequoiasempervirens forest at Salt Point State Park, California
Authors: Finney Mark A. , Martin Robert E.
Published: January 2008

Fire occurrence data between the 12th and 20th centuries were obtained from analysis of fire scars on coast redwood (Sequoiasempervirens (D. Don.) Endl.) and bishop pine (Pinusmuricata D. Don.). Mean fire intervals were calculated for settlement and presettlement periods from fire scar samples individually (point data) and from composites of samples aggregated within three approximately 200-ha study areas. Mean fire intervals from point data (20.5 to 29.0 years) were more than three times greater than mean intervals from composite data (6.1 to 9.3 years). Mean fire intervals derived from point data compared well with values previously reported, although substantial bias ascribed to point data suggests that these values for mean fire intervals in redwood forest communities are too large. A period of significantly longer fire intervals during the 17th century was suggested by analysis of fire intervals by century and using a moving average.