Epidemiology of Pseudomonas aeruginosa in agricultural areas.

A prevailing opinion is that the strains of Pseudomonas aeruginosa that infects both plants and humans are two separate species. This study strongly disputes that notion until the modern molecular technology proves otherwise. This paper examines a spectrum of strains occurring in nature, their habitats, dissemination, their relationship to clinical strains, and the environmental conditions that favor their colonization of plants. The isolates were obtained from clinical specimens, plants, soil, and water. The identity of these strains was confirmed using pyocin typing and biochemical assays. The data reveal that agricultural soils, potted ornamental plants, hoses, fountains, and faucets frequently harbored P. aeruginosa. However, it was not commonly found in semi-arid areas, suggesting that moisture and high humidity is necessary for colonization and survival. Though found in soil, P. aeruginosa was seldom isolated on edible plant parts. The pathogenicity of various strains on plants was tested by inoculating vegetables, lettuce slices (Lactuca sativa L. "Great Lakes"), celery stalks (Apium graveolens L. var. Dulce], potato tuber slices (Solanum tuberosum L. "Whiterose"), tomato (Lycopersicon esculentum L. Mill), cucumber (Cucumis sativus L.), rutabaga (Brassica campestris L.), and carrot (Daucus carota L. var sativa). There was considerable variation in the strains' ability to cause rot, but no difference was observed between clinical isolates and others from agricultural fields, water, and soil. Two of the clinical isolates from burn patients, P. aeruginosa PA13 and PA14, exhibited the greatest virulence in causing rot in all the plants that were tested, especially on cucumber, lettuce, potato, and tomato. The study discusses how closely the epidemiology of P. aeruginosa relates to many plant pathogens, and the ability of human isolates to colonize plants and food material under favorable conditions. The biochemical and phenotypic similarity among strains from the clinical and agricultural material is strongly indicative that they are the same species and that plants and soil are natural reservoirs for P. aeruginosa.

Use of a Low-fidelity simulator to improve trans-nasal fibre-optic flexible laryngoscopy in the clinical setting: a randomized, single-blinded, prospective study.

BACKGROUND: Trans-nasal flexible fibre-optic laryngoscopy (TFFL) is an essential skill for otolaryngologists. There is evidence to suggest that simulators help residents acquire procedural skills. The objective of this study was to examine the effect of simulation on endoscopy skill acquistion. METHODS: A randomized controlled trial was conducted utilizing medical students and junior residents with limited experience in TFFL. Learners all performed a baseline endoscopy and were then randomized to receive either 45 minutes of simulation training or not. Following this, a second endoscopy was performed. Time to adequate visualization of the glottis, the percentage of time adequate visualization of the airway was maintained, and the number of collisions with mucosa were analyzed. Qualitative assessments were also obtained from the learner, patient, and staff laryngologist. RESULTS: Time to adequate visualization of the glottis and the number of mucosal collisions were significantly less during the second endoscopy, irrespective of the use of simulation (84.8 sec vs. 68 sec, p < 0.01; 5.0 vs. 3.2, p < 0.01, respectively). Analysis using a two-way ANOVA with interaction established that none of the quantitative measures analyzed in this study improved with the addition of simulation. CONCLUSION: Improvements in time to visualization of the glottis and number of mucosal contacts were seen between the first and second endoscopy irrespective of simulator use. No additional benefit was conferred with the use of a low-fidelity simulator.

Polyethylene implants in nasal septal restoration.

IMPORTANCE: Numerous techniques have been described to repair nasal septal perforations (SPs). However, many are technically challenging, with varying degrees of success. OBJECTIVE: To evaluate the use of polyethylene (Medpor; Porex Technologies) implants in the closure of nasal SPs. DESIGN AND SETTING: Prospective cohort study in an academic research setting. PARTICIPANTS: Fourteen patients with a nasal SP were identified between March 1, 2008, and February 1, 2011. INTERVENTION: Each patient underwent repair of the nasal SP with a polyethylene orbital sheet implant. After measuring the size of the SP, the implant was trimmed and shaped to fit appropriately. The implant was then placed between bilateral mucoperichondrial flaps using an endonasal approach. MAIN OUTCOME AND MEASURE: Successful closure of the nasal SP with an intact polyethylene graft and complete remucosalization by the 1-year follow-up visit. RESULTS: The most common initial symptoms of SPs were nasal obstruction, crusting, and epistaxis. The SPs ranged from 0.5 to 4.0 cm in diameter. Thirteen of 14 patients (93%) who underwent repair of their nasal SPs with a polyethylene implant had successful closure. CONCLUSION AND RELEVANCE: The use of polyethylene implants is effective and technically easy and is associated with low patient morbidity because it does not require the harvesting of tissue from other donor sites. LEVEL OF EVIDENCE: 4.

The significance of Streptococcus anginosus group in intracranial complications of pediatric rhinosinusitis.

OBJECTIVE: To assess the significance of the Streptococcus anginosus group in intracranial complications of pediatric patients with rhinosinusitis. DESIGN: Retrospective cohort study. SETTING: Tertiary pediatric hospital. PATIENTS: A 20-year review of medical records identified patients with intracranial complications resulting from rhinosinusitis. In the 50 cases identified, S anginosus was the most commonly implicated bacterial pathogen in 14 (28%). Documented data included demographics, cultured bacteria, immune status, sinuses involved, type of intracranial complication, otolaryngologic surgical and neurosurgical intervention, type and duration of antibiotics used, and resulting neurologic deficits. Complications and outcomes of cases of S anginosus group-associated rhinosinusitis were compared with those of other bacteria. MAIN OUTCOME MEASURES: The severity and outcomes of intracranial complications of pediatric rhinosinusitis due to S anginosus group bacteria compared with other bacteria. RESULTS: Infection caused by the S anginosus group resulted in more severe intracranial complications (P = .001). In addition, patients with S anginosus group-associated infections were more likely to require neurosurgical intervention (P < .001) and develop long-term neurologic deficits (P = .02). Intravenous antibiotics were administered for a longer duration (P < .001) for S anginosus group-associated infections. CONCLUSIONS: Rhinosinusitis associated with the S anginosus group should be considered a more serious infection relative to those caused by other pathogens. Streptococcus anginosus group bacteria are significantly more likely than other bacteria to cause more severe intracranial complications and neurologic deficits and to require neurosurgical intervention. A low threshold for intervention should be used for infection caused by this pathogen.

Evidence-based practice: management of adult sensorineural hearing loss.

Sensorineural hearing loss is a complex disease state influenced by genetics, age, noise, and many other factors. This article reviews our current knowledge regarding the causes of sensorineural hearing loss and reviews the more challenging clinical presentations of sensorineural hearing loss. We have reviewed the latest medical literature in an attempt to provide an evidence-based strategy for the assessment and management of sudden sensorineural hearing loss, rapidly progressive sensorineural hearing loss, and asymmetric/unilateral sensorineural hearing loss.

Impact of newer generation multidetector computed tomography on the diagnosis of abscesses in the head and neck.

OBJECTIVE: To understand how newer generation multidetector computed tomographic (NGCT) scanner technology (≥ 16 slices) has affected the imaging characteristics of head and neck abscesses. DESIGN: Retrospective chart review. SETTING: Tertiary referral centre. METHODS: Forty-eight patients with a head and neck abscess who underwent a soft tissue neck computed tomographic (CT) scan were identified from September 1, 2001, to December 1, 2008. The degree of rim enhancement, delta (Δ), was graded using mean Hounsfield units (HU) from five peripheral points and five central points from a representative CT slice. The difference was then calculated and compared between older generation computed tomography (OGCT; < 16 slices) and newer generation multidetector computed tomography (NGCT; ≥ 16 slices) using the Student t-test. A p value < .05 was considered significant. RESULTS: Forty-eight patients met our inclusion criteria. Of these, 20 were scanned with OGCT and 28 were scanned with NGCT. The mean peripheral point values were OGCT  =  78 HU (95% CI 71-86 HU), NGCT  =  74 HU (95% CI 68-80 HU); p  =  .3. The mean central point values were OGCT  =  24 HU (95% CI 21-28 HU), NGCT  =  26 HU (95% CI 21-31 HU), p  =  0.7. The mean delta values (mean peripheral HU--mean central HU) were OGCT  =  52 HU (95% CI 43-61 HU), NGCT  =  46 HU (95% CI 41-52 HU), p  =  .2. CONCLUSION: There is no significant difference between OGCT and NGCT in the amount of rim enhancement seen on CT scans of head and neck abscesses.

Effectiveness of the heat-activated nitinol smart piston stapes prosthesis in stapedectomy surgery.

OBJECTIVE: To compare the SMart piston stapes prosthesis to a standard manual crimp prosthesis on operative time and air-bone gap (ABG) closure in stapedectomy. DESIGN: Retrospective chart review. SETTING: Tertiary referral centre. METHODS: The charts of patients undergoing stapedectomy for otosclerosis were analyzed. We compared the results of 76 patients (80 ears) who received the autocrimping SMart piston prosthesis to those of 21 patients (21 ears) who received the conventional manual crimp Fisch-type prosthesis. Data were analyzed using t-test, chi-square, or two-way analysis of variance where appropriate. MAIN OUTCOME MEASURE: Operative time with ABG closure as a secondary outcome measure. RESULTS: There was a significant difference in operative time between the Fisch-type prosthesis and the SMart piston prosthesis groups. The operation required 28.9 ± 3.2 minutes when using the Fisch-type prosthesis, whereas 21.2 ± 2.4 minutes were needed when using the SMart piston (p < .001). There was a significant improvement in postoperative ABG for both the Fisch-type piston (28.1 ± 3.1 to 9.0 ± 1.4, p < .001) and the SMart piston (25.1 ± 3.7 to 8.2 ± 2.5, p < .001) groups. CONCLUSIONS: Use of the SMart piston prosthesis results in ABG closure similar to that of the traditional Fisch-type prosthesis but offers the added advantage of reduced operative time.

Identification of bacterial contaminants in sinus irrigation bottles from chronic rhinosinusitis patients.

OBJECTIVE: To determine if sinus irrigation bottles from patients with chronic rhinosinusitis (CRS) harbour bacterial contaminants. DESIGN: Patients with symptoms of CRS who showed no mucopurulent infection and had no history of surgery were enrolled in the study. Patients were instructed on the proper use and cleaning of sinus irrigation bottles and were asked to return their rinse bottle during follow-up visits. METHODS: Bacterial contaminants were cultured from the inner surface of the sinus irrigation bottles obtained from patients. Genomic deoxyribonucleic acid (DNA) was isolated from purified colonies and used to polymerase chain reaction (PCR) amplify the 16S ribosomal ribonucleic acid (rRNA) genes. PCR products were sequenced and analyzed in the Human Oral Microbiome Database (HOMD) for genus and species identification based on 16S ribosomal DNA (rDNA) sequence comparisons. MAIN OUTCOME MEASURES: The outcomes included the recovery of bacterial contaminants and their subsequent identification. RESULTS: In total, 142 bacterial isolates were cultured and identified. The organisms included known oral flora bacteria, as well as pathogens of the upper respiratory tract and sinuses. Thirty-two different bacterial species were identified from 11 patients. There was no correlation between the length of bottle use and the degree of contamination. CONCLUSION: This study highlights the risk of bacterial contamination of sinus irrigation bottles and the potential for patient reinoculation.

The role of the estrogen in neuroprotection: implications for neurodegenerative diseases.

In trying to rectify the differences in the risk, onset, and progression of neurodegenerative diseases between men and women, the gonadal hormone estrogen has been the primary focus of investigation for many years. Although this gender difference may encompass disparate and overlapping reasons, estrogen and signaling events mediated by its receptor have been shown to be neuroprotective in a number of neurodegenerative disease models such as Alzheimer's, Parkinson's, and Schizophrenia. Although data from human studies remains highly controversial, a large body of research findings suggests that this hormone plays a pivotal role in retarding and preventing the formation of neurodegenerative diseases through its receptor. By activating common intracellular signaling pathways and initiating "cross talk" with neurotrophins, estrogen plays an influential role in neuronal survival from injuries induced by ischemia or other environmental insults. Gaining a better understanding of these estrogen receptor mediated neuroprotective mechanisms may lead to new therapeutic strategies for the treatment or prevention of neurodegenerative diseases.

17-beta estradiol down regulates ganglionic microglial cells via nitric oxide release: presence of an estrogen receptor beta transcript.

OBJECTIVES: In earlier studies we have demonstrated that 17-beta-estradiol and an estrogen cell surface receptor can be found on various human cells where they are coupled to nitric oxide release. We also demonstrated the presence of estrogen signaling in Mytilus edulis ganglia. In the present report, we sought to determine a function for these ganglionic estrogen receptors, transcending a reproductive role for estrogen. MATERIAL & METHODS: Ganglionic microglial egress from excised pedal ganglia was examined microscopically following pharmacological treatments designed to determine a role for 17-beta-estradiol in microglial regulation via nitric oxide. Additionally, we examined the tissue by RT-PCR and sequence analysis for the estrogen receptor beta gene. RESULTS: In ganglia incubated with varying concentrations of 17-beta-estradiol-BSA there is a significant drop in microglial egress at the 24 hour observation period (58.7 +/- 7.4 vs. 17-beta-estradiol-BSA exposed = 14.7 +/- 1.5; P<0.01), which can be antagonized by tamoxifen and significantly diminished by L-NAME, a nitric oxide synthase inhibitor. By RT-PCR and sequence analysis Mytilus edulis pedal ganglia was found to express a 266 bp fragment of the estrogen receptor-beta gene, which exhibits 100% sequence identity with the human counterpart. CONCLUSION: These data suggest that 17-beta-estradiol-BSA is working on estrogen cell surface receptors since 17-beta-estradiol-BSA does not enter the cytoplasm and that these receptors are coupled to constitutive nitric oxide release. This study demonstrates that 17-beta-estradiol can down regulate microglial fMLP induced activation and activation following ganglionic excision.

The presence of 17-beta estradiol in Mytilus edulis gonadal tissues: evidence for estradiol isoforms.

OBJECTIVES: In earlier studies, we demonstrate that 17-beta -estradiol and an estrogen cell surface receptor can be found on various human cells, i.e., vascular endothelial, monocytes, and granulocytes, where they are coupled to nitric oxide release. We further demonstrated this phenomenon in the marine mussel Mytilus edulis ganglionic tissues. In the present report we sought to determine if estrogen can be found in M. edulis reproductive tissues. MATERIAL & METHODS: We determined the presence of 17-beta -estradiol via high pressure liquid chromatography (HPLC) and radioimmunoassay (RIA) in the animals gonads. This substance was further identified via nanoelectro-spray ionization quadrupole time of flight mass spectrometry (Q-TOF-MS). RESULTS: 17-beta -estradiol was identified and quantified in Mytilus gonads. Interestingly, we also determined that estradiol isoforms also were present in this tissue. CONCLUSION: These data demonstrate that 17-beta-estradiol and an estradiol isoform is present in M. edulis gonadal tissues, suggesting that they have functions related to reproduction. This further suggests that estrogen's association with reproductive activities has a long evolutionary history and that this association began in invertebrates.

Risk factors for breast cancer and the prognosis of African American women: estrogen's role.

Archival reports demonstrate that black females are in the minority of reported breast cancer cases, yet are given a significantly poorer prognosis than their white counterparts. Numerous studies have been conducted in an attempt to explain this discrepancy. In the past, socio-economic variables such as economic status and access to adequate health care have been the focus of attention. More recently there has been a shift to understanding the racial differences in genotype, as well as hormones related to tumor growth. In the present report, we explore the effects of increased estrogen levels as a precursor to the detrimental effects of breast cancer in African American women when compared to Caucasian women. Furthermore we will explore the effects of increased estrogen levels on the apoptotic events of p53 and Bcl-2 proteins. We conclude with a discussion regarding the antagonistic behavior of varying isoforms of estrogen receptors, and their relationship to nitric oxide (NO) as a free radical. The main focus of this paper is to address the many carcinogenic pathways that are instigated by estrogen and those which may be linked to obesity. By determining the relative concentration of estrogen and related proteins within black and white populations we hope to better understand the above mentioned disparity.

The nongenomic protective effects of estrogen on the male cardiovascular system: clinical and therapeutic implications in aging men.

Although the preponderance of studies investigating the effects of estrogen on vasomotor tone and function have focused on women, a number of recent studies have intriguingly shown that estrogen's rapid vasodilatory properties is also preserved in men. Unlike classical steroid transcription mediated pathways, estrogen's acute vasodilatory effect is mediated by calcium dependent cell surface estrogen receptors that stimulate constitutive endothelial nitric oxide synthase (eNOS) activity. The transient release of eNOS derived nitric oxide exerts profound physiological effects on the vasculature exerting a state of cellular inhibition (i.e. vasodilation). Thus, the partial or complete attenuation of this rapid signaling system can promote endothelial dysfunction, an early pathophysiological event in atherosclerotic development. Consequently, human males experiencing age-related declines in testosterone and aromatase derived estradiol plasma levels may lose a vital cardioprotective mechanism that preserves proper endothelial function. Therapeutic strategies to preserve basal nitric oxide levels through the maintenance of normal physiological estradiol levels may confer cardiovascular benefits to aging males.

Estrogen signaling at the cell surface coupled to nitric oxide release in Mytilus edulis nervous system.

In previous studies we have demonstrated release of nitric oxide (NO) in human tissues following exposure to estrogen. We now designed experiments to determine whether estrogen is present in the neural tissue of Mytilus edulis, a marine mollusk, and whether, as in vertebrates, it stimulates constitutive NO synthase activity. After HPLC purification of 17beta-estradiol (17beta-E(2)) from M. edulis ganglionic tissue, we confirmed the presence of 17beta-E(2) by RIA and ES-Q-TOF-MS analysis. We further found that when either exogenous or endogenous (purified HPLC fraction) 17beta-E(2) was added to pedal ganglia, there was immediate concentration-dependent NO release. Furthermore, 17beta-E(2) conjugated to BSA also stimulated NO release, suggesting mediation by a membrane surface receptor. Tamoxifen, an estrogen receptor antagonist, inhibited the action of both 17beta-E(2) and 17beta-E(2) conjugated to BSA, further supporting the presence of an estrogen receptor. In addition, by Western blot analysis with anti-ER-beta antibodies, we observed a 55-kDa protein in both the membrane and cytosolic fractions in pedal ganglia as well as in human leukocytes (that have been previously shown to express ER-beta). In summary, our results suggest that a physiological dose of estrogen acutely stimulates NO release within pedal ganglia via an estrogen cell surface receptor.