bluuebunny/crossref_metadata_2025_split huggingface dataset:
Diversity of iron oxidizers in wetland soils revealed by novel 16S rRNA primers targeting Gallionella-related bacteria
Authors: Wang Juanjuan , Muyzer Gerard , Bodelier Paul L E , Laanbroek Hendrikus J 
Published: February 2009

Abstract
Neutrophilic iron-oxidizing bacteria (FeOB) are important catalysts of iron cycling in wetland environments. However, little is known about their diversity and distribution in various environments. The aim of this study was to develop a PCR-DGGE assay enabling the detection of neutrophilic iron oxidizers in wetland habitats. Gradient tubes were used to enrich FeOB. From these enrichments, a clone library was established on the basis of the almost complete 16S rRNA gene using the universal bacterial primers 27f and 1492r. This clone library consisted of mainly α- and β-Proteobacteria, among which two major clusters were closely related to Gallionella spp. Specific probes and primers were developed on the basis of this 16S rRNA gene clone library. The newly designed Gallionella-specific 16S rRNA gene primer set 122f/998r was applied to community DNA obtained from three contrasting wetland environments, followed by Denaturing Gradient Gel Electrophoresis (DGGE) analysis. A second 16S rRNA gene clone library was constructed using the PCR products from one of our sampling sites amplified with the newly developed primer set 122f/998r. The cloned 16S rRNA gene sequences all represented novel culturable iron oxidizers most closely related to Gallionella sp. On the basis of their nucleotide sequences, four groups could be identified that were comparable to the DGGE banding pattern obtained before with the same PCR products as used for the second clone library. Using these Gallionella-specific 16S rRNA gene-based primers, in combination with DGGE, first insights into the diversity and distribution of these bacteria in wetland soils were obtained.
In situ transcriptomic analysis of the globally important keystone N2-fixing taxon Crocosphaera watsonii
Authors: Hewson Ian , Poretsky Rachel S , Beinart Roxanne A , White Angelicque E , Shi Tuo , Bench Shellie R , Moisander Pia H , Paerl Ryan W , Tripp H James , Montoya Joseph P , Moran Mary Ann , Zehr Jonathan P 
Published: February 2009

Abstract
The diazotrophic cyanobacterium Crocosphaera watsonii supplies fixed nitrogen (N) to N-depleted surface waters of the tropical oceans, but the factors that determine its distribution and contribution to global N2 fixation are not well constrained for natural populations. Despite the heterogeneity of the marine environment, the genome of C. watsonii is highly conserved in nucleotide sequence in contrast to sympatric planktonic cyanobacteria. We applied a whole assemblage shotgun transcript sequencing approach to samples collected from a bloom of C. watsonii observed in the South Pacific to understand the genomic mechanisms that may lead to high population densities. We obtained 999 C. watsonii transcript reads from two metatranscriptomes prepared from mixed assemblage RNA collected in the day and at night. The C. watsonii population had unexpectedly high transcription of hypothetical protein genes (31% of protein-encoding genes) and transposases (12%). Furthermore, genes were expressed that are necessary for living in the oligotrophic ocean, including the nitrogenase cluster and the iron-stress-induced protein A (isiA) that functions to protect photosystem I from high-light-induced damage. C. watsonii transcripts retrieved from metatranscriptomes at other locations in the southwest Pacific Ocean, station ALOHA and the equatorial Atlantic Ocean were similar in composition to those recovered in the enriched population. Quantitative PCR and quantitative reverse transcriptase PCR were used to confirm the high expression of these genes within the bloom, but transcription patterns varied at shallower and deeper horizons. These data represent the first transcript study of a rare individual microorganism in situ and provide insight into the mechanisms of genome diversification and the ecophysiology of natural populations of keystone organisms that are important in global nitrogen cycling.
Sclerosing Rhabdomyosarcoma: A Rare Variant With Predilection for the Head and Neck
Authors: Knipe Thomas A. , Chandra Rakesh K. , Bugg M Frederick 
Published: February 2009

AbstractObjectives/Hypothesis: Sclerosing rhabdomyosarcoma is a newly described variant of rhabdomyosarcoma with a predilection for the head and neck. Little has been written on the topic, because of the scarcity of the disease and its recent recognition as a distinct entity. The present report describes the fifth confirmed case of sclerosing rhabdomyosarcoma and is the first report in the otolaryngology literature.Study Design: Case report.Methods: The authors have reported the case of a 66‐year‐old woman with a 35‐year history of heavy cigarette smoking and daily alcohol consumption and a 2‐month history of progressive dysphagia and dysarthria secondary to an enlarging tongue mass. Urgent tracheotomy was performed for impending respiratory embarrassment. Direct laryngoscopy revealed a bulky, exophytic mass involving the base of tongue. Specimens were obtained and submitted for analysis.Results: Initial frozen‐section analysis of the specimens favored carcinoma, although subsequent immunohistochemical analysis disproved this. The diagnosis of sclerosing rhabdomyosarcoma was based on microscopic appearance and patterns of gene expression, including the expression of desmin and myogenin. A search of the literature revealed only four confirmed cases of sclerosing rhabdomyosarcoma. With the inclusion of the oropharyngeal tumor in the present report, three of the five confirmed cases have occurred in the head and neck.Conclusion: Sclerosing rhabdomyosarcoma is a rare variant of rhabdomyosarcoma that has a predilection for the head and neck. The clinical presentation may mimic carcinoma. The otolaryngologist—head and neck surgeon must be familiar with this disease entity.
National Assessment of Business‐of‐Medicine Training and Its Implications for the Development of a Business‐of‐Medicine Curriculum
Authors: Patel Anit T. , Bohmer Richard M. J. , Barbour J Robert , Fried Marvin P. 
Published: February 2009

AbstractObjectives/Hypothesis: The objectives were, first, to determine the current state of business training in otolaryngology residency programs in the United States and, second, to lay the groundwork for development of a business‐of‐medicine (BOM) curriculum.Study Design: Cross‐sectional survey.Methods: A survey concerning methodology and topics for management training of residents was mailed to the chairpersons or program directors of the 102 otolaryngology residency programs. A similar survey was sent to 576 otolaryngology graduates (classes of 2000, 2001, and 2002). An interactive BOM curriculum on CD‐ROM was developed based on the results.Results: The response rate among program directors was 74.5% (76 of 102), and among the otolaryngology graduates, 38.2% (220 of 575). Seventy‐five percent of graduates rated their BOM training as poor or fair. Only 8% rated their BOM training as excellent. Twenty percent of the graduates responded to having a BOM course during residency. Recent graduates reported that a BOM course can best be taught through lectures and apprenticeship/mentoring, whereas program directors reported that a BOM course can best be taught through lectures and outside consultants. Graduates reported that coding compliance was the topic most neglected in residency, whereas program directors reported that coding compliance was the main topic covered in the business training. Both groups agreed that department attending physicians have the most impact on a resident's business training. Program directors reported that correct coding, planning one's entry into medical practice, risk management, and reimbursement issues are the most important topics for residents to learn, whereas recent graduates stated that the most important topics should be correct coding, office management, risk management, and reimbursement.Conclusion: The present study reflects a perceived necessity for improvement of BOM training in otolaryngology residency programs. Based on this finding, the outcome measures from the survey, and the authors' own experience from business courses given in the first author's department, a BOM curriculum was developed that is general enough to target all otolaryngology residents and intended to provide business skills which result in improved use of resources and, ultimately, higher quality of care.
Alterations of Nasal Mucociliary Clearance in Association with HIV Infection and the Effect of Guaifenesin Therapy
Authors: Rosen Elizabeth J. , Calhoun Karen H. 
Published: February 2009

AbstractObjectives: To determine if human immunodeficiency virus (HIV) infection is associated with a prolonged mucociliary clearance time (MCT) and to evaluate the effect of guaifenesin on MCT in HIV+ patients.Study Design: A cross‐sectional study comparing HIV+ and HIV− volunteers followed by a prospective, randomized, double‐blind, placebo‐controlled study of HIV+ patients before and after guaifenesin treatment.Methods: Twenty‐five HIV+ patients and 29 HIV− controls were enrolled and MCT was measured using the saccharin method. A separate group of 20 HIV+ patients participated in the second arm of the study and underwent saccharin testing before and after a 3‐week course of guaifenesin or placebo. All study participants completed a medical history questionnaire, a sinonasal symptom (SNOT‐16) survey, and were examined with both anterior rhinoscopy and rigid nasal endoscopy.Results: There was a significant difference (P < .002) in the MCT between the HIV+ group (13.3 ± SD 7.5 minutes) and the HIV− controls (9.2 ± SD 3.9 minutes). The difference in MCT between the guaifenesin and placebo groups did not reach statistical significance (P >.05). The HIV+ group had a higher SNOT‐16 score compared to HIV− controls (21.1 vs. 7.4, P < .001). Guaifenesin therapy in HIV+ patients led to a significant improvement in the SNOT‐16 score (P < .05).Conclusions: Compared to HIV− controls, HIV+ patients have a prolonged MCT and more sinonasal symptoms as indicated by a higher SNOT‐16 score. Guaifenesin therapy was associated with improved SNOT‐16 scores, although there was not a detectable improvement in MCT. Use of guaifenesin in HIV+ patients with sinonasal disease may lead to improved patient perception of quality of life
Gastrostomy Tubes in Patients with Advanced Head and Neck Cancer
Authors: Ahmed Khwaja Asif , Samant Sandeep , Vieira Francisco 
Published: February 2009

AbstractObjectives: To measure the percentage of patients requiring gastrostomy tubes (G‐tubes) and the timing of their placement, in addition to studying whether pretreatment variables (T stage, tumor site, N stage) and intratreatment variables (weight loss during treatment) are valid predictors for the need for G‐tube placement.Study Design: Retrospective case control study.Methods: Retrospective review of a prospectively collected database with chart reviews was carried out on 477 patients treated on a regimen of intraarterial cisplatin and concurrent radiation. The likelihood of requiring a G‐tube was calculated by studying several independent variables using chi‐square analysis and the unpaired t test.Results: Two hundred twenty (46%) patients had G‐tubes placed, with mean time of placement being on day 20 after the initiation of treatment. Patients with T4 disease were statistically more likely to require a G‐tube (50% vs. 37%, P < .05). Patients were less likely to require a G‐tube when the primary site of tumor involved the larynx or paranasal sinuses (P < .05). There were no statistically significant differences between the two groups with regards to patient age, sex, N stage, and weight changes over the course of treatment. The odds of requiring a G‐tube were highest for tumors involving the hypopharynx (80%), oral cavity (52%), and oropharynx (49%).Conclusions: Although clinical judgment appears to be sufficient for deciding when G‐tube placement is warranted in our population, the threshold for placing a tube should be lower in those patients who had a higher likelihood of requiring a G‐tube during the course of treatment, including those with advanced disease of the oral cavity, oropharynx, and hypopharynx.
Endoscopic Surgery of the Anterior Skull Base
Authors: Casler John D. , Doolittle Andrew M. , Mair Eric A. 
Published: February 2009

AbstractObjectives/Hypothesis: Traditional surgical approaches to the anterior skull base often involve craniotomy, facial incisions, disruption of skeletal framework, tracheotomy, and an extended hospital stay. As experience with endoscopic sinus surgery has grown, the techniques and equipment have been found to be adaptable to treatment of lesions of the anterior and central skull base. A minimally invasive endoscopic approach theoretically offers the advantages of avoiding facial incisions, osteotomies, and tracheotomy; surgery should be less painful, recovery quicker, and hospital stays should be shorter. The study attempted to assess endoscopic approaches to the anterior and central skull base for its ability to achieve those goals.Study Design: Retrospective review of 72 cases performed at a single institution from November 1996 to July 2003. A subgroup of 15 patients who underwent endoscopic approach to their pituitary tumors was compared with a similar group of 15 patients who underwent traditional open trans‐sphenoidal surgery for their pituitary tumors.Methods: Patient records were analyzed and information tabulated for age, sex, disease, location of lesion, operative time, use of image‐guided surgical systems, blood loss, length of intensive care unit stay, duration of operative pain, length of postoperative hospitalization, complications, and completeness of resection.Results: Of the cases, 86.1% were performed exclusively endoscopically, and 13.9% used a combination of endoscopic and open techniques. An image‐guided surgical system was used in 83% of cases. Hospital length of stay was 2.3 days for the exclusively endoscopic group as opposed to 8 days for the combined group. With the patients with pituitary tumors, operative times were similar between the two groups (255.13 vs. 245.73 min), blood loss was less in the endoscopic group (125.33 vs. 243.33 mL), pain duration was shorter in the endoscopic group (10 of 15 patients pain free on postoperative day 1 vs. 2 of 15 patients pain free in the open group), and intensive care unit stay and hospital length of stay were both shorter in the endoscopic group. Complication rates and completeness of resection was similar in both groups, although the open group had a higher rate of complications related to the approach to the sella.Conclusion: The study demonstrated the safety and efficacy of judicious endoscopic approaches to anterior skull base lesions. An outcomes assessment in pituitary surgery demonstrates advantages of an endoscopic approach in appropriate cases.
Intraoperative Intact Parathyroid Hormone Level Monitoring as a Guide to Parathyroid Reimplantation after Thyroidectomy
Authors: Friedman Michael , Vidyasagar Ramakrishnan , Bliznikas Darius , Joseph Ninos J. 
Published: February 2009

AbstractObjective: The goal of this study was to determine whether intraoperative intact parathyroid hormone (IOiPTH) levels can predict the functional status of remaining parathyroids at the end of total thyroidectomy and thereby be a guide for parathyroid autotransplantation when glands are deemed not functional.Study Design: Prospective study involving 23 patients undergoing either total thyroidectomy or completion thyroidectomyMethods: During surgery, an attempt was made to identify all four parathyroid glands. Normal size vascular glands were preserved, whereas avascular glands were microdissected and reimplanted. Serial IOiPTH was measured preoperatively after each parathyroid was identified, manipulated, or removed and serum iPTH measurements were done postoperatively up to 56 days.Results: The sensitivity of low IOiPTH in identifying a devascularized gland was 88.9%, and specificity was 92.9%. A normal IOiPTH level indicates at least two functioning glands. IOiPTH levels between 1.5 and 10 pg/mL indicate only one functional gland. Undetectable IOiPTH levels indicate no residual functioning gland.Conclusions: For patients undergoing total or completion thyroidectomy, IOiPTH should be routinely measured at the end of the procedure, and a level less than 10 pg/mL requires reassessment of remaining parathyroid glands. Vascularized glands should be preserved regardless of IOiPTH levels. Devascularized glands or glands of questionable vascularity should be considered for autotransplantation.
Acoustic Neuromas after Failed Radiation Therapy: Challenges of Surgical Salvage
Authors: Limb Charles J. , Long Donlin M. , Niparko John K. 
Published: February 2009

AbstractObjectives: As stereotactic radiation has emerged as a treatment option for acoustic neuromas, cases that require surgical salvage after unsuccessful radiation have emerged. We present a comparison of the technical challenges faced by the surgeons in the treatment of irradiated versus nonirradiated acoustic neuromas.Study Design: Matched case‐control series.Methods: We identified nine patients with acoustic neuromas that required surgical resection after radiation therapy. Cases were performed with suboccipital and translabyrinthine approaches. Nine nonirradiated case‐control subjects matched for age, sex, tumor size, and surgical approach were identified for purposes of general comparison. Operative findings and outcomes were compared for the two groups.Results: Surgical removal was found to be significantly more difficult after radiation therapy because of increased fibrosis and adhesion to adjacent nervous structures, particularly at the porus acousticus. Excessive scarring hindered identification of the facial nerve and added uncertainty as to the completeness of tumor removal. Decompression of the internal auditory canal (IAC) dura and resection of neoplasm in the IAC before cerebellopontine angle dissection was required for facial nerve identification. Operative time was significantly longer for irradiated cases, and facial nerve outcomes tended to be poorer, particularly when facial nerve dysfunction prompted the salvage procedure.Conclusions: Surgical salvage of acoustic neuromas after radiation therapy is feasible, but it presents technical challenges beyond that associated with primary surgical therapy. Poorer outcomes of postoperative cranial nerve status were caused primarily by anatomic changes at the nerve/tumor interface. As surgical experience with the irradiated acoustic neuroma grows, operative observations should be incorporated into the counsel provided to patients with acoustic neuromas as they weigh different management options.
Experimental and Clinical Studies of Malleus Fixation
Authors: Nakajima Hideko Heidi , Ravicz Michael E. , Rosowski John J. , Peake William T. , Merchant Saumil N. 
Published: February 2009

AbstractObjectives/Hypothesis: Preoperative clinical diagnosis of malleus fixation can be difficult. “Fixation” of the malleus can be caused by various disorders or diseases: fibrous tissue, bony spurs, and neo‐osteogenesis around the malleus head or stiffening of the anterior malleal ligament. The conductive hearing loss produced by these disorders or diseases has not been well characterized. The study goals were 1) to determine the effects of various types of malleus fixation using a cadaveric temporal bone preparation and 2) to assess the clinical utility of umbo velocity measurements in preoperative differential diagnosis of malleus fixation and stapes fixation.Methods: Umbo and stapes velocity were measured in 18 fresh cadaveric human temporal bones with laser vibrometry before and after controlled application of adhesives to the malleus, stapes, or both ossicles.Results: Each simulated pathological condition produced a specific degree of loss in stapes velocity: stiffening of anterior malleal ligament, 0 to 8 dB; fibrous tissue around malleus head, less than 10 dB; bony bar to malleus head, 10 to 30 dB; and extensive neo‐osteogenesis around malleus head, greater than 35 dB. Simulated malleus fixations generally produced similar reductions in both umbo and stapes velocity. Stapes fixation reduced stapes velocity with little change in umbo velocity. Because the change in stapes velocity would be similar to conductive hearing loss, experimental results were directly compared with clinical measurements of umbo velocity in surgically confirmed cases of malleus or stapes fixation. The effects of malleus and stapes fixations between the clinical and experimental data were similar.Conclusion: The study showed that measurements of umbo velocity and air‐bone gap can enable one to diagnose malleus fixation and specifies how to differentiate malleus from stapes fixation.
Time and Dose Effects of Mitomycin C on Extracellular Matrix Fibroblasts and Proteins
Authors: Ferguson Bryce , Gray Steven D. , Thibeault Susan 
Published: February 2009

AbstractObjectives/Hypothesis: The objective was to determine treatment dose and time‐dependent effects of injected mitomycin C on extracellular matrix fibroblasts, collagen, and fibronectin, important mediators in the wound healing response, in a rat cutaneous wound model.Study Design: A prospective, controlled animal study.Methods: Forty rats were injected with three different doses (0.4, 2.3, and 5.0 mg/mL) of mitomycin C at three different wound sites with a fourth wound site receiving saline as a control. The rats were grouped to have their tissue harvested at five different dates ranging from 1 week to 8 weeks. After death, samples from the wound site underwent Western blot analysis for collagen and fibronectin and histological analysis measuring fibroblast apoptosis.Results: Over an 8‐week period, collagen and fibronectin significantly decreased and fibroblast apoptosis significantly increased. No correlation was found between the injected dose of mitomycin C and either the extracellular matrix protein concentration or the rate of fibroblast apoptosis.Conclusion: Mitomycin C demonstrated a long‐term effect in a wound, inhibiting collagen and fibronectin production and inducing apoptosis. Use of mitomycin C in excess of 0.4 mg/mL did not alter protein concentrations or rate of apoptosis.