Suriya Jayawardena

Pseudomonas aeruginosa AmpR Is a Global Transcriptional Factor That Regulates Expression of AmpC and PoxB β-Lactamases, Proteases, Quorum Sensing, and Other Virulence Factors

ABSTRACT In members of the family Enterobacteriaceae, ampC, which encodes a β-lactamase, is regulated by an upstream, divergently transcribed gene, ampR. However, in Pseudomonas aeruginosa, the regulation of ampC is not understood. In this study, we compared the characteristics of a P. aeruginosa ampR mutant, PAOampR, with that of an isogenic ampR+ parent. The ampR mutation greatly altered AmpC production. In the absence of antibiotic, PAOampR expressed increased basal β-lactamase levels. However, this increase was not followed by a concomitant increase in the PampC promoter activity. The discrepancy in protein and transcription analyses led us to discover the presence of another chromosomal AmpR-regulated β-lactamase, PoxB. We found that the expression of P. aeruginosa ampR greatly altered the β-lactamase production from ampC and poxB in Escherichia coli: it up-regulated AmpC but down-regulated PoxB activities. In addition, the constitutive PampR promoter activity in PAOampR indicated that AmpR did not autoregulate in the absence or presence of inducers. We further demonstrated that AmpR is a global regulator because the strain carrying the ampR mutation produced higher levels of pyocyanin and LasA protease and lower levels of LasB elastase than the wild-type strain. The increase in LasA levels was positively correlated with the PlasA, PlasI, and PlasR expression. The reduction in the LasB activity was positively correlated with the PrhlR expression. Thus, AmpR plays a dual role, positively regulating the ampC, lasB, and rhlR expression levels and negatively regulating the poxB, lasA, lasI, and lasR expression levels.

Prescription errors and the impact of computerized prescription order entry system in a community-based hospital

Adverse drug events occur often in hospitals. They can be prevented to a large extent by minimizing the human errors of prescription writing. To evaluate the efficacy of a computerized prescription order entry (CPOE) system with the help of ancillary support in minimizing prescription errors. Retrospective study carried out in a community-based urban teaching hospital in south Brooklyn, NY from January 2004 to January 2005. Errors were categorized into inappropriate dosage adjustment for creatinine clearance, duplication, incorrect orders, allergy verification, and incomplete orders. The pharmacists identified the type of error, the severity of error, the class of drug involved, and the department that made the error. A total of 466,311 prescriptions were entered in the period of 1 year. There were 3513 errors during this period (7.53 errors per 1000 prescriptions). More than half of these errors were made by the internal medicine specialty. In our study, 50% of the errors were severe errors (overdosing medications with narrow therapeutic index or over-riding allergies), 46.28% were moderate errors (overdosing, wrong dosing, duplicate orders, or prescribing multiple antibiotics), and 3.71% were not harmful errors (wrong dosing or incomplete orders). The errors were also categorized according to the class of medication. Errors in antibiotic prescription accounted for 53.9% of all errors. The pharmacist detected all these prescription errors as the prescriptions were reviewed in the CPOE system. Prescription errors are common medical errors seen in hospitals. The CPOE system has prevented and alerted the prescriber and pharmacist to dosage errors and allergies. Involvement of the pharmacist in reviewing the prescription and alerting the physician has minimized prescription errors to a great degree in our hospital setting. The incidence of prescription errors before the CPOE has been reported to range from 3 to 99 per 1000 prescriptions. The disparity could be due to the definition of medical errors, which has changed over the years, and also number of prescriptions included in the study and the study design.

Isolated diffuse hyperplastic gastric polyposis presenting with severe anemia

IntroductionGastric polyps exist in a wide variety of types, most of which are small and often benign. Discovery of gastric polyps during Endoscopy necessitates biopsies.Case presentationWe present a case report of an isolated diffuse hyperplastic gastric polyposis in a 26 years old Hispanic female when she was investigated for profound anemia. The Esophagogastroduodenoscopy revealed numerous gastric polyps filling the entire stomach. She was treated with near-total gastrectomy and her anemia resolvedConclusionIsolated diffuse hyperplasic gastric polyposis with normal gastrin level is a rare entity and can present with severe anemia.

Death Within 48 Hours of Admission to the Emergency Department: The Value of Autopsy

Objective:To identify factors that contribute to patient death within 48 hours of admission to the emergency department. Materials and Methods:A retrospective study of the patients who died within 48 hours of admission to the emergency department, from the years 2000 to 2003. The antemortem diagnosis and postmortem diagnosis were compared. Results:A total of 189 autopsies were performed. The mean age at death for men (41.4 years) was lower than that for women (48.6) (p = 0.02). In both men and women, cardiac system involvement was the leading cause of death (27.5%), with myocardial infarction at 21.2%. The other common causes of death for both genders were blunt trauma (20.1%), intoxication with alcohol and/or other drugs (13.8%), penetrating trauma (gunshot or stab injuries) (13.2%), pulmonary thromboembolism (7.9%), and death caused by other respiratory causes (7.4%). Death caused by pulmonary thromboembolism was more common in women, whereas death caused by strokes, burns, and penetrating trauma were seen almost exclusively in men. Conclusions:Our study found a considerable concordance between the presumed antemortem cause of death and the postmortem findings. Although the mean age of death caused by myocardial infarction in our study was 52.45 years, MI caused a significant number of deaths among adults younger than 40 years of age.

Hypercalcemia-leukocytosis syndrome in a patient with cavitating squamous cell carcinoma of the lung

IntroductionLung cancer is the leading cause of death among the cancers seen in the United States. Hypercalcemia and leukocytosis are two common paraneoplastic syndromes associated with lung cancer. Unfortunately patients presenting with Hypercalcemia- leukocytosis syndrome has a worse prognosis than patients presenting with lung cancer alone.Case presentationWe present a 67 yr old Caucasian male with a history of active smoking presenting as pneumonia being diagnosed as cavitating squamous cell carcinoma of the lung with hypercalcemia-leukocytosis syndromeConclusionThere should be a high degree of suspicion to diagnose lung cancer in patients presenting with symptoms of paraneoplastic syndrome.

Anterolateral papillary muscle rupture caused by myocardial infarction: A case report

BackgroundThe rupture of the anterolateral papillary muscle is less common than the posteromedial papillary muscle since the anterolateral muscle has dual blood supplies, while the posteromedial papillary muscle has a single blood supply.Case presentationWe present a case report of a 42 year old male presenting with heart failure being diagnosed to have mitral regurgitation from the partial rupture of the anterolateral papillary muscle due to coronary artery disease. The patient underwent a mitral valve replacement and concomitant coronary artery bypass grafting of the first and the second obtuse marginal arteries.ConclusionAcute mitral regurgitation can be precipitated by acute myocardial infarction due to rupture of the anterolateral papillary muscle.

Paravalvular mitral valve leakage presenting as congestive heart failure, missed by TTE but diagnosed by TEE: a case report

BackgroundDiagnosis of prosthetic valve leakage by the transthoracic echocardiogram (TTE) technique is more difficult. These limitations are diminished with the use of transesophageal echocardiogram (TEE) techniques.Case reportA 71 year old Caucasian male presented with symptoms and signs of congestive heart failure. Past medical history included a bio-prosthetic mitral valve replacement for severe mitral regurgitation. TTE showed possible mitral regurgitation. As the TTE did not correlate with the finding of a high E-velocity, a TEE was performed, which showed a significant paravalvular leak of moderate severity around the bio-prosthetic mitral valve.ConclusionThere should be a high degree of suspicion to diagnose a paravalvular leak.

Takotsubo cardiomyopathy in a 68-year old Russian female

IntroductionTakotsubo cardiomyopathy also known as transient left ventricular apical ballooning, stress-induced cardiomyopathy can present with retrosternal chest pain with EKG changes that can mimic a myocardial infraction.Case PresentationWe present a 68 female with sudden onset retrosternal squeezing chest pain with positive cardiac enzymes and EKG changes suggestive of acute ST-elevation myocardial infraction. Patient was thrombolysed and cardiac cauterization done later showed normal coronaries with ballooning of the left ventricle apex.ConclusionTakotsubo cardiomyopathy is a very rare disease entity yet can present to the emergency room as acute myocardial infraction.