bluuebunny/crossref_metadata_2025 huggingface dataset:
Anaerobes in ejaculates of subfertile men
Authors: Eggert-Kruse Waltraud , Rohr Gerhard , Ströck Wolfram , Pohl Susanne , Schwalbach Beate , Runnebaum Benno
Published: January 2004

The clinical significance of micro-organisms in semen samples of asymptomatic subfertile patients is a matter of constant debate. Usually little attention is paid to anaerobic bacteria as they are sensitive to transportation and culturing, and differentiation is difficult, costly and time-consuming. In the present study, special screening was carried out for anaerobes in ejaculates in addition to the routine microbial cultures of genital secretions of both partners. In addition to standard semen analysis and evaluation of sperm ability to penetrate cervical mucus (CM) in vivo (postcoital testing) and in vitro using a standardized test system, semen samples from 126 randomly chosen males of couples with a median duration of infertility of 4 years were examined for colonization with anaerobic bacteria. All couples were without clinical signs or symptoms of genital tract infection. The special care taken for anaerobic growth in semen samples gave a high rate of positive cultures and showed that nearly all ejaculates (99%) were colonized with anaerobic micro-organisms, and potentially pathogenic species were found in 71% of men. This rate was more than four times higher than that obtained with routine cultures and standard transportation (16%). Anaerobic bacterial growth of ≥106 colony forming units (CFU)/ml was seen in 42% (total range 103-108 CFU/ml). In addition, aerobic growth was found in 96%(≥106 CFU/ml in 21%), potentially pathogenic species in 61% of semen specimens. There were no marked differences in the prevalence of anaerobic micro-organisms in patients with reduced or normal sperm count, motility or morphology. Nor was there any significant difference in anaerobic colonization between samples with impaired or good ability to penetrate CM of female partners (in vivo or in vitro), or the CM of fertile donors in the in-vitro sperm-cervical mucus penetration test (SCMPT) in this asymptomatic group of patients. There was no clear association between microbial colonization and subsequent fertility in vivo within an observation period of 6 months. The results of this study suggest that anaerobic bacteria are often not detected when routine methods for microbial evaluation are used. This should be considered during assisted reproduction and in patients with symptoms of genital tract infection and should lead to further studies in infertile patients where subclinical infection or inflammation is indicated by specific markers in semen samples.
Different Endoscopic Surgical Strategies in the Management of Inverted Papilloma of the Sinonasal Tract: Experience with 47 Patients
Authors: Tomenzoli Davide , Castelnuovo Paolo , Pagella Fabio , Berlucchi Marco , Pianta Luca , Delù Giovanni , Maroldi Roberto , Nicolai Piero
Published: January 2004

Objective: To demonstrate the potentials and limitations of three different endoscopic procedures employed for treatment of inverted papilloma (IP) of the sinonasal tract.

Study Design: Retrospective analysis of a cohort of patients treated at two University hospitals.

Methods: From January 1992 to June 2000, 47 patients with IP underwent endoscopic resection. Preoperative workup included multiple biopsies of the lesion and imaging evaluation by computed tomography or magnetic resonance imaging. Massive skull base erosion, intradural or intraorbital extension, extensive involvement of the frontal sinus, abundant scar tissue caused by previous surgery, or the concomitant presence of squamous cell carcinoma were considered absolute contraindications for a purely endoscopic approach. Three types of resection were used: ethmoidectomy with wide antrostomy and sphenoidotomy (type 1) for IPs confined to the middle meatus, medial maxillectomy with ethmoidectomy and sphenoidotomy (type 2) for IPs partially invading the maxillary sinus, and a Sturmann‐Canfield operation (type 3) for IPs involving the mucosa of the alveolar recess or of the anterolateral corner of the maxillary sinus. All patients were followed by periodic endoscopic evaluations.

Results: Type 1, 2, and 3 resections were performed in 26, 15, and 6 patients, respectively. No recurrences were observed after a mean follow‐up of 55 (range 30–132) months. One patient, who underwent a type 2 resection, developed a stenosis of the lacrimal pathways requiring endoscopic dacryocystorhinostomy.

Conclusions: Our experience confirms that endoscopic surgery is an effective and safe method of treatment for most IPs. The availability of different endoscopic techniques allows the entity of the dissection to be modulated in relation to the extent of disease. Strict application of selection criteria, meticulous use of subperiosteal dissection in the involved areas, and regular follow‐up evaluation are key elements for success.
Comparison of Topical Medication Delivery Systems after Sinus Surgery
Authors: Miller Timothy R. , Muntz Harlan R. , Gilbert M Erik , Orlandi Richard R.
Published: January 2004

Objectives: To compare the distribution patterns of topical medication delivery systems in the sinonasal region and upper respiratory tract after functional endoscopic sinus surgery.

Study Design: Prospective descriptive evaluation.

Methods: Four topical delivery systems (spray bottle, atomizer, nebulizer, and bulb syringe) were studied. Using a dye solution as a marker, we independently applied the four topical delivery systems to a population of patients with chronic rhinosinusitis who had undergone functional endoscopic sinus surgery. The anatomic distributions were videotaped using flexible fiberoptic endoscopy. Three blinded observers independently rated the anatomic distribution of dye using a 4 point scale. Statistical analysis was performed using analysis of variance (ANOVA) and Dunn posttesting.

Results: Seven participants completed the study. All participants had undergone bilateral maxillary antrostomies, bilateral total ethmoidectomies, and bilateral sphenoidotomies. Five sinonasal sites and the larynx were evaluated for dye deposition. Interobserver agreement reached 95.6%. There was no statistical difference between the atomizer and spray bottle. The bulb syringe was statistically superior to the nebulizer in all sinonasal sites and statistically superior to the atomizer and spray bottle in the ethmoidal region. Dye was rarely seen within the larynx.

Conclusions: The delivery systems tested were shown to have significant differences in their capability to place dye in specific sinonasal areas. Because topical medications are commonly administered to postoperative patients, these differences may have important clinical implications.
The Effects of Upper Airway Surgery for Obstructive Sleep Apnea on Nasal Continuous Positive Airway Pressure Settings
Authors: Masdon James Lee , Magnuson J Scott , Youngblood Garland
Published: January 2004

Objectives/Hypothesis: The objectives were to determine whether upper airway surgery lowers nasal continuous positive airway pressure (CPAP) settings for patients who require CPAP postoperatively for unresolved obstructive sleep apnea and to assess CPAP tolerability after upper airway surgery.

Study Design: Retrospective chart review.

Methods: Patients who underwent upper airway surgery with preoperative and postoperative polysomnography at the University of Alabama at Birmingham (Birmingham, AL) between 1995 and 2000 were the focus of the study. Upper airway surgery was defined as uvulopalatopharyngoplasty alone or in addition to septoplasty and turbinoplasty. Recommended CPAP settings were recorded from preoperative and postoperative polysomnography studies to determine whether CPAP settings were decreased following surgery. A response to surgery was defined as a decrease of the recommended CPAP setting by at least 1 cm of water. A telephone interview was conducted to determine whether upper airway surgery improved CPAP comfort.

Results: In 51.4% of the patients, CPAP settings were decreased following surgery. Continuous positive airway pressure settings were increased in 28.6% of patients and unchanged in 20%. Of the six patients who consistently used CPAP before and after surgery, four reported increased comfort postoperatively.

Conclusion: Upper airway surgery does not predictably reduce CPAP settings in the patient who requires postoperative CPAP for unresolved obstructive sleep apnea. Upper airway surgery may improve CPAP tolerability.
Outpatient Endoscopic Zenker Diverticulotomy
Authors: Gross Neil D. , Cohen James I. , Andersen Peter E.
Published: January 2004

Objectives/Hypothesis: Staple‐assisted, endoscopic Zenker diverticulotomy has been shown to decrease both cost of treatment and length of convalescence when compared with the standard open approach. Although the endoscopic technique is generally considered to be safe, the feasibility of outpatient endoscopic Zenker diverticulotomy has never been reported.

Study Design: Retrospective cohort study.

Methods: All endoscopic Zenker diverticulotomy procedures performed at Oregon Health and Science University (Portland, OR) between 1998 and 2002 were reviewed. The study group was limited to patients whose surgeries were planned on an outpatient basis. Medical charts were reviewed for indications, demographics, operative findings, complications, and resolution of symptoms.

Results: Of the 51 patients who underwent endoscopic, staple‐assisted Zenker diverticulotomy, 40 were treated with the intent of outpatient management. Thirty‐two cases were primary surgeries, and eight cases were revision treatments. The average patient age was 68 years (age range, 35–91 y), and the mean follow‐up period was 5.9 months (range, 1–37 mo). Eight (20%) complications were noted in the study group. Intraoperative complications included 3 patients (7.5%) with mucosal disruptions. These patients underwent uneventful suture repair of small hypopharyngeal mucosal tears encountered intraoperatively and were temporarily observed in the hospital. One patient was admitted for postoperative urinary retention and another for fever and tachycardia 48 hours after surgery. One patient sustained a myocardial infarction. The remainder of patients were fed immediately and discharged home on the day of surgery. Two patients (5%) had iatrogenic tooth fracture.

Conclusion: Appropriately selected patients undergoing endoscopic, staple‐assisted Zenker diverticulotomy can be managed safely on an outpatient basis. Intraoperative complications, such as a mucosal disruption, warrant conversion to inpatient monitoring.
Endoscopic Vertical Partial Laryngectomy
Authors: Davis R Kim , Hadley Kevin , Smith Marshall E.
Published: January 2004

Objective: To explain the significant difference between microlaryngoscopy with cordectomy and endoscopic vertical partial laryngectomy (EVPL), to describe the efficacy of EVPL on T1b and T2 glottic squamous cell carcinoma, and to evaluate EVPL with postoperative irradiation in T2 glottic cancer with impaired true vocal cord mobility.

Study Design: Retrospective review.

Methods: Twenty‐six patients seen at the University of Utah Health Science Center between 1987 and 2000 with bilateral T1 (T1b) or T2 squamous cell carcinoma of the glottic larynx underwent EVPL. T2 cancers were classified as follows: a = unilateral disease, b = bilateral disease; i = impaired mobility. T1b and T2a glottic cancer patients received surgery alone, whereas impaired mobility patients (T2ai + T2bi) patients received surgery followed by planned postoperative irradiation. Patients were assessed for primary site control, perioperative and long‐term complications, and ultimate cancer control.

Results: Survival in the total group was 88.5%, with local control at 92.3%. The two recurrent patients were salvaged by total laryngectomy. For the whole group, anterior commissure involvement was present in 57.7% (15 of 26). Thirteen T2 (5 T2ai + 8 T2bi) carcinoma patients underwent combined therapy, with 8 (61.5%) of these patients having anterior commissure involvement. Two of these patients were upstaged at surgery, one to T3 and one to T4. Local control was 84.5%. Thirteen patients were treated by surgery only, with five of these patients having failed previous irradiation. Survival was 92.3% and local control 100%. This group included two T2bi patients, two patients upstaged to T4 on the basis of extension beyond the subglottis to the anterior wall of the trachea, 3 T2b, and 6 T2a patients. Anterior commissure involvement was seen in 7 (53.8%) of these patients.

Conclusions: EVPL alone controlled all T1b and T2a glottic cancer patients, even in the presence of greater than 50% anterior commissure involvement. The significant difference between EVPL and classical microlaryngoscopy with cordectomy was carefully described. EVPL with planned postoperative irradiation resulted in an 85% local control rate in clinically staged T2ai and T2bi cancer patients, including the three upstaged patients.
Current Applications of Microarrays in Head and Neck Cancer Research
Authors: Warner Giles C. , Reis Patricia P. , Makitie Antti A. , Sukhai Mahadeo A. , Arora Shilpi , Jurisica Igor , Wells Richard A. , Gullane Patrick , Irish Jonathan , Kamel‐Reid Suzanne
Published: January 2004

Objectives/Hypothesis: The objective was to introduce microarray technology and its applications in cancer research to the head and neck clinician.

Study Design: Literature review combined with methodology and examples from the authors' experiences with microarray analysis of tumors of the head and neck.

Methods: Search of literature and the authors' experience was made for technical details, alternative methods of data analysis, available bioinformatics tools, and applications of microarrays in cancer research.

Results: Microarrays allow the simultaneous analysis of the expression of thousands of genes. The use of a well‐developed microarray study design leads to informative results. There are various bioinformatics resources widely available to aid in the analysis of microarray data. However, there is not yet a gold standard for analysis because this methodology is still evolving.

Conclusion: Microarray studies may allow researchers to identify genetic changes relevant to diagnosis and prognosis in patients with head and neck cancer. Although still relatively new, this powerful methodology has immense potential to aid in understanding of the genetic changes that are important in head and neck cancer.
Myxoma of the Lateral Skull Base: Clinical Features and Management
Authors: Windfuhr J P , Schwerdtfeger F P
Published: January 2004

Objective: To evaluate the clinical features and incidence of true myxomas affecting the lateral skull base.

Material and Methods: Illustrative case report and review of the relevant literature. Included are all reports of myxomas according to the histopathologic definition of Stout.

Results: Despite nine case reports, only four patients matched the histopathologic criteria of a true myxoma growing in the lateral skull base. Facial palsy occurred in three adults with additional otalgia in one and progressive hearing loss (HL) in another patient. Our patient initially presented with signs of recurrent otitis media. The mastoid cavity was involved in all patients.

Conclusion: Differential diagnosis of lesions occurring in the lateral skull base should include true myxoma. Correct diagnosis should be based on immunohistopathology to rule out malignant tumors. Radical surgery is the treatment of choice, but surgeons should respect vital structures and esthetic consequences.
Experimental Sinusitis in a Rhinogenic Model
Authors: Kara Cüneyt Orhan , Çetin Çiğdem Banu , Demirkan Neşe , Şengül Mustafa , Topuz Bülent , Pnar Hilmi Şafak , Pakdemirli Emre
Published: January 2004

Objectives/Hypothesis: The objectives were to determine the optimal sinusitis induction period and to examine microbiological and histopathological changes of sinusitis recovery stage in a rhinogenic sinusitis model.

Methods: A synthetic sponge was inserted into the right‐side nasal cavities of rabbits. The sponge was impregnated with a Streptococcus pneumoniae strain in group 1 and with sterile saline solution in groups 2 and 3. After the fourth day of sponge insertion, sinuses were examined by coronal computed tomography scans at two‐day intervals until any radiological evidence of sinusitis was observed. When sinusitis was detected radiologically, five rabbits each from groups 1 and 2 were killed for histological examination. To determine the recovery period of sinusitis, sponges were removed from the rest of the rabbits in groups 1 and 2. Rabbits were selected randomly and killed on the 15th and the 30th days of the recovery period, immediately after radiological examinations. Group 3 was considered a sham group.

Results: Sinusitis induction was performed in all rabbits in groups 1 and 2 until the 8th day. After the sponges were removed, inflammation persisted until the 30th day of the study.

Conclusion: In a rhinogenic sinusitis model, although histological features of sinusitis were demonstrated, further studies are required to standardize this model and to examine whether or not the studied bacterial strain spreads from nasal cavity into sinus.
Effect of Clarithromycin on Nuclear Factor‐κB and Transforming Growth Factor‐β in Chronic Rhinosinusitis
Authors: Wallwork Ben , Coman William , Mackay‐Sim Alan , Cervin Anders
Published: January 2004

Objectives: Long‐term, low‐dose macrolide therapy is effective in the treatment of chronic rhinosinusitis. It is believed that macrolide antibiotics produce this benefit through an anti‐inflammatory effect. In this study, the effect of clarithromycin treatment on the expression of transforming growth factor (TGF)‐β and the key pro‐inflammatory nuclear transcription factor, NF‐κB, was examined in vitro and in vivo.

Study Design and Methods: In vitro: nasal mucosa was obtained from 10 patients with chronic sinusitis and was cultured for 24 hours in the presence of clarithromycin or control. Cellular expression of TGF‐β and NF‐κB was determined by immunohistochemistry. In vivo: 10 patients with chronic rhinosinusitis were treated for 3 months with clarithromycin. Nasal mucosal biopsies were taken pre‐ and posttreatment. Cellular expression of TGF‐β and NF‐κB was again determined by immunohistochemistry.

Results: Clarithromycin, when applied to nasal biopsies in vitro, reduced cellular expression of TGF‐β and NF‐κB. Nasal biopsies taken before and after clarithromycin treatment showed no differences in cellular expression of NF‐κB or TGF‐β.

Conclusion: Clarithromycin can reduce cellular expression of TGF‐β and NF‐κB when applied in vitro, but its action during clinical therapy is less clear. Clarithromycin is capable of inhibiting pro‐inflammatory cytokines in vitro, and reductions of TGF‐β and NF‐κB may represent additional mechanisms by which macrolides reduce inflammation in chronic airway disease. Discrepancies between the actions of clarithromycin on nasal biopsies in vitro and after clinical therapy warrant further investigation.
Juvenile Angiofibromas: Changing Surgical Concept Over the Last 20 Years
Authors: Mann Wolf J. , Jecker Peter , Amedee Ronald G.
Published: January 2004

Objectives: Nasopharyngeal angiofibroma is a rare tumor. Several surgical approaches have been established, including transpalatal, lateral rhinotomy, craniofacial, and midface degloving procedures. More recently, less invasive endonasal approaches have been used. In a retrospective study, we analyzed the outcome of surgical treatment for angiofibroma to determine whether an endonasal approach was as effective as other, more invasive techniques for removing the tumors.

Methods: Thirty patients with histologically confirmed angiofibromas were treated by surgical removal at two institutions during a 20‐year period. Tumors were staged according to size and extension on the basis of imaging and surgical findings using the Fisch classification. Specific analysis of the operative approaches and recurrence rate by stage were included. Recurrent or residual disease was handled by surgical excision.

Results: The number of patients treated increased during the last 10 years in both institutions, but no major changes in distribution of tumor stages were observed. In the most recent years, the endonasal approach has been favored. All 30 patients remain alive and free of disease.

Conclusions: During the last 12 years, we have undergone a marked shift toward endonasal procedures while the tumor stages of the patients treated remained the same. Our results demonstrate that angiofibromas may be managed successfully using less invasive techniques, thereby reducing morbidity, without increasing the chance of recurrence.
Optimum Tension for Partial Ossicular Replacement Prosthesis Reconstruction in the Human Middle Ear
Authors: Morris David P. , Bance Manohar , van Wijhe Rene G. , Kiefte Michael , Smith Rachael
Published: January 2004

Objective: Hearing results from ossiculoplasty are unpredictable. There are many potentially modifiable parameters. One parameter that has not been adequately investigated in the past is the effect of tension on the mechanical functioning of the prosthesis. Our goal was to investigate this parameter further, with the hypothesis that the mechanical functioning of partial ossicular replacement prostheses (PORP) from the stapes head to the eardrum will be affected by the tension that they are placed under.

Methods: Fresh temporal bones were used to reconstruct a missing incus defect with a PORP‐type prosthesis. Three different lengths of PORP were used, and the stapes vibrations were measured with a laser Doppler vibrometer using a calibrated standard sound in the ear canal. Eight temporal bones were used.

Results: Tension had a very significant effect on stapes vibration. In general, loose prostheses resulted in the best overall vibration transmission. The effects were most marked at the lower frequencies. There was a slight advantage to tight prostheses in the higher frequencies, but much less than the decrement in lower frequencies with tight prostheses.

Conclusion: In ossicular reconstruction, best stapes vibration results in our model are achieved by shorter prostheses, which result in lower tension.
Long‐Term Effects of Cerebellar Retraction in the Microsurgical Resection of Vestibular Schwannomas
Authors: Kim Harold H. , Johnston Ross , Wiet Richard J. , Kumar Arvind
Published: January 2004

Objective: To determine the long‐term effects, if any, of the greater cerebellar retraction that is required for retrosigmoid vestibular schwannoma versus resection as compared with the minimal, if any, cerebellar retraction required for translabyrinthine versus resection.

Study Design: Retrospective case control.

Methods: All patients who underwent retrosigmoid versus resection between 1988 to 2000 by one surgeon were identified. These patients were contacted and asked to complete the Dizziness Handicap Inventory (DHI). These patients were then matched to patients who underwent translabyrinthine versus resection according to age at surgery, age at time of study, sex, and size of tumor. Total DHI and subcategory DHI scores were compared using the Student t test.

Results: Thirty‐three patients underwent the retrosigmoid approach, and 27 were contacted for completion of the survey, with a 81.3% response rate. Forty‐six patients who underwent translabyrinthine versus resection were matched to the retrosigmoid group. Thirty‐six were contacted and completed the survey for a 75% response rate. Twenty‐seven patients that most closely matched the retrosigmoid group comprised the translabyrinthine group used for comparison. Minimal differences were seen between the two groups. Mean total DHI score for the retrosigmoid group was 17.6, which was not significantly different from the mean score of 16.8 seen in the translabyrinthine group (P = .888). When comparing small tumors (<1.5 cm), total DHI scores were not found to be significantly different (P = .859). We observed similar findings in those with intermediate‐sized tumors (1.5–3 cm).

Conclusion: The significantly greater cerebellar retraction that is necessary for retrosigmoid versus resection does not result in greater long‐term balance and disability as compared with those patients who have undergone the translabyrinthine approach.
Ebselen‐Mediated Protection From Single and Repeated Noise Exposure in Rat
Authors: Lynch Eric D. , Gu Rende , Pierce Carol , Kil Jonathan
Published: January 2004

Objectives/Hypothesis: Ebselen, a glutathione peroxidase mimic, is a candidate compound for the prevention of noise‐induced hearing loss.

Study Design: Single‐blinded, placebo‐controlled study.

Methods: Methods included single and repeated noise exposures on F‐344 female rats given oral or injected ebselen or vehicle before and after noise, evoked auditory brainstem responses using click and pure‐tone stimuli, light and fluorescence microscopy of cochleae stained with 4′,6‐Diamidino‐2‐phenylindole (DAPI) and fluorescein isothiocyanate–phalloidin, and statistical power determined by ANOVA.

Results: Auditory brainstem response indicated that ebselen provided significant protection from both temporary and permanent threshold shifts following single and repeated noise exposure. On average, three times more outer hair cells were lost in control versus ebselen‐treated animals.

Conclusion: Ebselen reduces noise‐induced hearing loss in rats.
Vestibular Evoked Myogenic Potentials and Glycerol Testing
Authors: Magliulo Giuseppe , Cuiuli Giuseppe , Gagliardi Mario , Ciniglio‐Appiani Giuseppe , D'Amico Raffaello
Published: January 2004

Objectives/Hypothesis: The objective was to evaluate dizziness as the first symptom of endolymphatic hydrops, which could provide valuable information on the initial stages of endolymphatic hydrops development.

Study Design: The present investigation was specifically designed to establish whether a combination of the traditional glycerol test and the vestibular evoked myogenic potential (VEMP) glycerol test is capable of diagnosing endolymphatic hydrops early and to identify potential Meniere's disease. The study was limited to patients who complained of dizziness as their only vestibular symptom.

Methods: Thirty‐eight consecutive patients with dizziness who had received no treatment were investigated. Each patient underwent glycerol testing measured with both conventional pure‐tone audiometry and vestibular evoked myogenic potential testing. For the vestibular evoked myogenic potential glycerol test, an increase of more than 20% in both latency and amplitude after glycerol intake was considered an improvement.

Results: In one patient, the reappearance of the vestibular evoked myogenic potentials was observed. In another six patients, there was an increase in the vestibular evoked myogenic potential amplitudes, unilaterally in four cases and bilaterally in two. One patient showed a bilateral improvement in amplitude and an unilateral amelioration in latency.

Conclusion: The assumption of saccular dilation as a sign of early Meniere's disease was not supported by the literature, which considered saccular hydrops as the final progression of the dilation of the endolymphatic compartments into the cochlea. These data seem to indicate that in our patients a saccular dysfunction rather than an early saccular hydrops has been documented, confirming vestibular evoked myogenic potential testing as an intriguing diagnostic option for a lesion of this structure. The vestibular evoked myogenic potential glycerol test proved capable of identifying dysfunctions of the saccule that were not otherwise detectable by the routine methods. Therefore, the vestibular evoked myogenic potential glycerol test should be considered as an additional method of diagnosis in patients with vertigo or dizziness.
Audiovestibular Findings in Patients with Mitochondrial A1555G Mutation
Authors: Noguchi Yoshihiro , Yashima Takatoshi , Ito Taku , Sumi Takuro , Tsuzuku Toshihiro , Kitamura Ken
Published: January 2004

Objective: The aims of this study were to explore the prevalence of the A1555G mutation among a group of Japanese patients and to assess the pathophysiology of the hearing impairment associated with the mutation.

Study Design: Genetic study and retrospective chart review.

Methods: We screened for the mitochondrial DNA A1555G mutation in 138 unrelated Japanese deaf patients, including 63 sporadic cases and 75 familial cases with different patterns of inheritance. When available, patients carrying the mutation received audiovestibular examinations, including speech audiometry, distortion‐product otoacoustic emission (DPOAE) testing, electrocochleography (ECochG), and electronystagmography.

Results: One of 63 sporadic cases (1.6%) and 6 of 75 familial cases (8.0%) carried the A1555G mutation. Patients with the mutation and a familial history included two with autosomal recessive inheritance and four with maternal inheritance. In addition, two of six patients (33.3%) presenting with aminoglycoside‐induced sensorineural hearing loss (SNHL) were associated with the A1555G mutation. All but one of the patients carrying the mutation showed high‐frequency SNHL. Distortion‐product levels of DPOAE were reduced to the noise levels, suggesting the A1555G mutation caused cochlear deafness. Cochlear microphonics in ECochG showed elevation of the detection thresholds and corresponding audiometric thresholds. The ECochG data implied that patients with high‐frequency SNHL had impairment of the cochlear hair cells that was most severe toward the basal turn. The electronystagmographic findings indicated no apparent vestibular dysfunction.

Conclusions: Screening for the A1555G mutation, even in patients with idiopathic bilateral SNHL, likely would be useful for preventing further development and/or acceleration of the deafness.
Microbiology of Stents in Laryngotracheal Reconstruction
Authors: Simoni Payman , Wiatrak Brian J.
Published: January 2004

Objectives: Granulation tissue often forms around a laryngotracheal stent, tracheostomy tube, or other airway prosthesis, especially if infection occurs. We studied the types and frequency of organisms colonizing stents used in pediatric laryngotracheal reconstruction.

Study Design: This prospective study included 21 patients undergoing 23 consecutive laryngotracheal reconstructions with stents between 1991 and 1999.

Methods: After endoscopic removal, each laryngotracheal stent was placed immediately in a sterile container and transported to the laboratory. Specimens for culture were obtained from biofilms on the stents and plated on agars for growth of aerobic, anaerobic, and fungal organisms. Culture results were analyzed with regard to patient age, duration of stenting, and graft type.

Results: All stents were colonized with more than one pathogen (range 2–7). The most frequent aerobic isolates were Streptococcus viridians, Pseudomonas aeruginosa, Staphylococcus aureus, Haemophilus influenza, and Neisseria species. Anaerobic organisms were isolated in 26% of cases. Candida species were isolated in 57% of the cases; patients whose stents were colonized with Candida were significantly (P = .007) older (mean 77.5 months) than those not colonized with this organism (mean 26.1 months)

Conclusions: The antibiotic agents currently used for children undergoing laryngotracheal reconstruction target mainly aerobic organisms. Despite prophylactic measures, the incidence of granulation tissue formation is clinically significant, and the prevalence of anaerobic, including fungal, pathogens is high. Antibiotic therapy directed toward controlling anaerobic and fungal organisms could help in controlling local inflammation and thus granulation tissue formation.
Inspiratory Activation of the Vocal Cord Adductor, Part I: Human Study in Patients With Restricted Abduction of the Vocal Cords
Authors: Shiba Keisuke , Isono Shiroh , Sekita Yasuko , Tanaka Atsuko
Published: January 2004

Objectives/Hypothesis: In patients with restricted abduction of the vocal cords, it has generally been accepted that glottis narrowing with laryngeal stridor during inspiration is attributed to static and passive obstruction of the glottis. However, active glottis narrowing can also be contributory. We tested the hypothesis that the vocal cord adductor is activated during inspiration in patients with restricted abduction of the vocal cords.

Study Design: Electromyographic evaluation of vocal cord adductor activity in patients with restricted abduction of the vocal cords.

Methods: Five patients with restricted abduction of the vocal cords who had stridor with mild to severe dyspnea during wakefulness were anesthetized with propofol. We recorded the adductor muscle electromyogram during breathing through a laryngeal mask airway while observing the vocal cord movement endoscopically. In three patients who had undergone tracheostomy, we also recorded adductor firing patterns not only while closing but also while opening the tracheostoma.

Results: The adductor was activated during inspiration, and the glottis was narrowed in accordance with inspiratory stridor. This adductor inspiratory activity was abolished by opening the tracheostoma in the tracheostomized patients.

Conclusion: Not only static or passive glottis narrowing but also active narrowing may contribute to inspiratory flow limitation in patients with restricted abduction of the vocal cords. This active glottis narrowing is probably induced by an airway reflex.
Effect of Astrocytic Energy Metabolism Depressant on 14C-Acetate Uptake in Intact Rat Brain
Authors: Hosoi Rie , Okada Maki , Hatazawa Jun , Gee Antony , Inoue Osamu
Published: January 2004

Fluorocitrate, a selective astrocytic toxin, was microinjected into the right striatum of rat brain, and the regional distribution of 14C-acetate was measured using autoradiography. A significant reduction (more than 80%) in 14C-acetate uptake over a 5-minute period was observed in the right striatum, compared with that in the left striatum (saline infused), 4 hours after fluorocitrate (1 nmol/μL) infusion. This effect was transient, and 14C-acetate uptake had almost returned to normal at 24 hours after the fluorocitrate infusion. In contrast, the regional blood flow in the striatum, as determined using 14C-iodoamphetamine, was significantly increased by the fluorocitrate infusion. The present observations indicate that 14C-acetate uptake might be a useful characteristic for examining astrocytic energy metabolism in the intact brain.
Time Course and Cellular Distribution of Hsp27 and Hsp72 Stress Protein Expression in a Quantitative Gerbil Model of Ischemic Injury and Tolerance: Thresholds for Hsp72 Induction and Hilar Lesioning in the Context of Ischemic Preconditioning
Authors: Nishino Kazuhiko , Nowak Thaddeus S.
Published: January 2004

The distribution and time course of expression of the heat shock/stress proteins, hsp27 and hsp72, were evaluated in a highly controlled gerbil model of ischemic injury and tolerance induction, in which the duration of ischemic depolarization in each hippocampus provides a precise quantitative index of insult severity. Gerbils were subjected to brief priming insults (2- to 3.5-minute depolarization) that produce optimal preconditioning, to severe test insults (6- to 8.5-minute depolarization) that produce complete CA1 neuron loss in naive animals, or to combined insults administered 1 week apart, after which almost complete tolerance to CA1 neuron injury is observed. Immunoreactivities of hsp27, hsp72, glial fibrillary acidic protein and microtubule-associated protein 2 (MAP2) were evaluated in animals perfused at defined intervals after the final insult in each treatment group, using a variation of established antigen-retrieval procedures that significantly improves detection of many proteins in vibratome brain sections. Hsp72 was detected in CA1 neurons of some hippocampi 2 to 4 days after preconditioning, but this was only seen after the longest priming depolarizations, whereas shorter insults that still induced optimal tolerance failed to induce hsp72. Hsp72 was induced after test insults in preconditioned hippocampi, but at a higher depolarization threshold than observed for naive animals. An astrocytic localization of hsp27 was observed in regions of neuron injury, as indicated by reduced MAP2 immunoreactivity, and was primarily restricted to dentate hilus after preconditioning insults. These results establish that limited hilar lesions are characteristic of optimal preconditioning, whereas prior neuronal expression of either hsp72 or hsp27 is not required for ischemic tolerance.
Restriction-mediated Differential Display (RMDD) Identifies pip92 as a Pro-Apoptotic Gene Product Induced during Focal Cerebral Ischemia
Authors: Schneider Armin , Fischer Achim , Weber Daniela , von Ahsen Oliver , Scheek Sigrid , Krüger Carola , Rossner Moritz , Klaussner Bettina , Faucheron Nadine , Kammandel Birgitta , Goetz Bernhard , Herrmann Oliver , Bach Alfred , Schwaninger Markus
Published: January 2004

Studies of gene expression changes after cerebral ischemia can provide novel insight into ischemic pathophysiology. Here we describe application of restriction-mediated differential display to screening for differentially expressed genes after focal cerebral ischemia. This method combines the nonredundant generation of biotin-labeled fragment sets with the excellent resolution of direct blotting electrophoresis, reliable fragment recovery, and a novel clone selection strategy. Using the filament model in mouse with 90 minutes MCA occlusion followed by 2, 6, and 20 hours reperfusion, we have compared gene expression in sham-operated animals to both the ipsi- and contralateral forebrain hemisphere of ischemic mice. Our screening method has resulted in the identification of 70 genes differentially regulated after transient middle cerebral artery occlusion (MCAO), several of which represent unknown clones. We have identified many of the previously published regulated genes, lending high credibility to our method. Surprisingly, we detected a high degree of correspondent regulation of genes in the nonischemic hemisphere. A high percentage of genes coding for proteins in the respiratory chain was found to be up-regulated after ischemia, potentially representing a new mechanism involved in counteracting energy failure or radical generation in cerebral ischemia. One particularly interesting gene, whose upregulation by ischemia has not been described before, is pip92; this gene shows a rapid and long-lasting induction after cerebral ischemia. Here we demonstrate that pip92 induces cell death in primary neurons and displays several hallmarks of pro-apoptotic activity upon overexpression, supporting the notion that we have identified a novel pathophysiological player in cerebral ischemia. In summary, restriction-mediated differential display has proven its suitability for screening complex samples such as brain to reliably identify regulated genes, which can uncover novel pathophysiological mechanisms.
Genome-Wide Gene Expression Analysis for Induced Ischemic Tolerance and Delayed Neuronal Death following Transient Global Ischemia in Rats
Authors: Kawahara Nobutaka , Wang Yan , Mukasa Akitake , Furuya Kazuhide , Shimizu Tatsuya , Hamakubo Takao , Aburatani Hiroyuki , Kodama Tatsuhiko , Kirino Takaaki
Published: January 2004

enome-wide gene expression analysis of the hippocampal CA1 region was conducted in a rat global ischemia model for delayed neuronal death and induced ischemic tolerance using an oligonucleotide-based DNA microarray containing 8,799 probes. The results showed that expression levels of 246 transcripts were increased and 213 were decreased following ischemia, corresponding to 5.1% of the represented probe sets. These changes were divided into seven expression clusters using hierarchical cluster analysis, each with distinct conditions and time-specific patterns. Ischemic tolerance was associated with transient up-regulation of transcription factors (c-Fos, JunB Egr-1, −2, −4, NGFI-B), Hsp70 and MAP kinase cascade-related genes (MKP-1), which are implicated cell survival. Delayed neuronal death exhibited complex long-lasting changes of expression, such as up-regulation of proapoptotic genes (GADD153, Smad2, Dral, Caspase-2 and −3) and down-regulation of genes implicated in survival signaling (MKK2, and PI4 kinase, DAG/PKC signaling pathways), suggesting an imbalance between death and survival signals. Our study provides a differential gene expression profile between delayed neuronal death and induced ischemic tolerance in a genome-wide analysis, and contributes to further understanding of the complex molecular pathophysiology in cerebral ischemia.
Vascular Endothelial Growth Factor Induces Abnormal Microvasculature in the Endoglin Heterozygous Mouse Brain
Authors: Xu Bin , Wu Yong Qin , Huey Madeleine , Arthur Helen M. , Marchuk Douglas A. , Hashimoto Tomoki , Young William L. , Yang Guo-Yuan
Published: January 2004

Hereditary hemorrhagic telangiectasia (HHT), associated with brain arteriovenous malformations, is caused by a loss of function mutation in either the endoglin (HHT1) or activin receptor-like kinase 1 gene (ALK-1, HHT2). Endoglin heterozygous ( Eng+/−)mice have been proposed as a disease model. To better understand the role of endoglin in vascular malformation development, we examined the effect of vascular endothelial growth factor (VEGF) hyperstimulation on microvessels in adult endoglin heterozygous ( Eng+/−) mice using an adenoviral vector to deliver recombinant human VEGF165 cDNA (Ad hVEGF) into basal ganglia. VEGF expression was increased in Ad hVEGF mice compared with the Ad lacZ and saline group ( P < 0.05) and localized to multiple cell types (neurons, astrocytes, endothelial cells, and smooth muscle cells) by double-labeled immunostaining. VEGF overexpression increased microvessel count for up to 4 weeks in both the Eng+/+ and Eng+/+ groups ( Eng+/+ 185 ± 14 vs. Eng+/− 201 ± 10 microvessels/mm2). Confocal microscopic examination revealed grossly abnormal microvessels in eight of nine Eng+/− mouse brains compared with zero of nine in Eng+/+ mice ( P < 0.05). Abnormal microvessels featured enlargement, clustering, twist, or spirals. VEGF receptor Flk-1 and TGF-β receptor 1 (TβR1) expression were reduced in the Eng+/− mouse brain compared with control.

Excessive VEGF stimulation may play a pivotal role in the initiation and development of brain vessel malformations in states of relative endoglin insufficiency in adulthood. These observations are relevant to our general understanding of the maintenance of vascular integrity.
Identification of Potential Stroke Targets by Lentiviral Vector Mediated Overexpression of HIF-1α and HIF-2α in a Primary Neuronal Model of Hypoxia
Authors: Ralph G. S. , Parham S. , Lee S. R. , Beard G. L. , Craigon M. H. , Ward N. , White J. R. , Barber R. D. , Rayner W. , Kingsman S. M. , Mundy C. R. , Mazarakis N. D. , Krige D.
Published: January 2004

The identification of genes differentially regulated by ischemia will lead to an improved understanding of cell death pathways such as those involved in the neuronal loss observed following a stroke. Furthermore, the characterization of such pathways could facilitate the identification of novel targets for stroke therapy. We have used a novel approach to amplify differential gene expression patterns in a primary neuronal model of stroke by employing a lentiviral vector system to specifically bias the transcriptional activation of hypoxically regulated genes. Overexpression of the hypoxia-induced transcription factor subunits HIF-1α and HIF-2α elevated hypoxia-mediated transcription of many known HIF-regulated genes well above control levels. Furthermore, many potentially novel HIF-regulated genes were discovered that were not previously identified as hypoxically regulated. Most of the novel genes identified were activated by a combination of HIF-2α overexpression and hypoxic insult. These included several genes with particular importance in cell survival pathways and of potential therapeutic value. Hypoxic induction of HIF-2α may therefore be a critical factor in mediating protective responses against ischemic injury. Further investigation of the genes identified in this study may provide increased understanding of the neuronal response to hypoxia and may uncover novel therapeutic targets for the treatment of cerebral ischemia.
Acf1 confers unique activities to ACF/CHRAC and promotes the formation rather than disruption of chromatin in vivo
Authors: Fyodorov Dmitry V. , Blower Michael D. , Karpen Gary H. , Kadonaga James T.
Published: January 2004

Chromatin assembly is required for the duplication of chromosomes. ACF (ATP-utilizingchromatin assembly and remodelingfactor) catalyzes the ATP-dependent assembly of periodic nucleosome arrays in vitro, and consists of Acf1 and the ISWI ATPase. Acf1 and ISWI are also subunits of CHRAC (chromatinaccessibilitycomplex), whose biochemical activities are similar to those of ACF. Here we investigate the in vivo function of the Acf1 subunit of ACF/CHRAC inDrosophila. Although most Acf1 null animals die during the larval-pupal transition, Acf1 is not absolutely required for viability. The loss of Acf1 results in a decrease in the periodicity of nucleosome arrays as well as a shorter nucleosomal repeat length in bulk chromatin in embryos. Biochemical experiments with Acf1-deficient embryo extracts further indicate that ACF/CHRAC is a major chromatin assembly factor inDrosophila. The phenotypes of flies lacking Acf1 suggest that ACF/CHRAC promotes the formation of repressive chromatin. Theacf1gene is involved in the establishment and/or maintenance of transcriptional silencing in pericentric heterochromatin and in the chromatin-dependent repression byPolycombgroup genes. Moreover, cells in animals lacking Acf1 exhibit an acceleration of progression through S phase, which is consistent with a decrease in chromatin-mediated repression of DNA replication. In addition,acf1genetically interacts withnap1, which encodes the NAP-1 nucleosome assembly protein. These findings collectively indicate that ACF/CHRAC functions in the assembly of periodic nucleosome arrays that contribute to the repression of genetic activity in the eukaryotic nucleus.
Rad6 plays a role in transcriptional activation through ubiquitylation of histone H2B
Authors: Kao Cheng-Fu , Hillyer Cory , Tsukuda Toyoko , Henry Karl , Berger Shelley , Osley Mary Ann
Published: January 2004

Covalent modifications of the histone N tails play important roles in eukaryotic gene expression. Histone acetylation, in particular, is required for the activation of a subset of eukaryotic genes through the targeted recruitment of histone acetyltransferases. We have reported that a histone C tail modification, ubiquitylation of H2B, is required for optimal expression of several inducible yeast genes, consistent with a role in transcriptional activation. H2B was shown to be ubiquitylated and then deubiquitylated at the GAL1 core promoter following galactose induction. We now show that the Rad6 protein, which catalyzes monoubiquitylation of H2B, is transiently associated with the GAL1 promoter upon gene activation, and that the period of its association temporally overlaps with the period of H2B ubiquitylation. Rad6 promoter association depends on the Gal4 activator and the Rad6-associated E3 ligase, Bre1, but is independent of the histone acetyltransferase, Gcn5. The SAGA complex, which contains a ubiquitin protease that targets H2B for deubiquitylation, is recruited to the GAL1 promoter in the absence of H2B ubiquitylation. The data suggest that Rad6 and SAGA function independently during galactose induction, and that the staged recruitment of these two factors to the GAL1 promoter regulates the ubiquitylation and deubiquitylation of H2B. We additionally show that both Rad6 and ubiquitylated H2B are absent from two regions of transcriptionally silent chromatin but present at genes that are actively transcribed. Thus, like histone H3 lysine 4 and lysine 79 methylation, two modifications that it regulates, Rad6-directed H2B ubiquitylation defines regions of active chromatin.