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Biomedical subjects

Michael Wolf

Publications and source records attributed to Michael Wolf.

At least 19 recordsLinked to original sources
PubMed2007

Clinical safety and diagnostic value of the gadolinium chelate gadoterate meglumine (Gd-DOTA).

OBJECTIVE: The purpose of this study was to assess the diagnostic value and safety of the contrast agent gadoterate meglumine (Gd-DOTA, DOTAREM, Guerbet, Roissy CdG Cedex, France) in the setting of a postmarketing surveillance study. MATERIALS AND METHODS: Between January 2004 and October 2005, radiologists in 61 radiologic institutions were asked to document the routine use of Gd-DOTA in a questionnaire. In addition to assessing the image quality and diagnostic value of the contrast-enhanced magnetic resonance imaging scans, we statistically evaluated and analyzed demographic and safety data. RESULTS: A total of 24,308 patients were intravenously injected with Gd-DOTA for various diagnostic examinations. The examination allowed for establishing a diagnosis in >99% of cases and image quality was rated as "excellent" or "good" in 97.5% of all cases. Adverse events were noted in only 0.4% of the examinations and were mostly rated as minor, such as feeling of warmth or taste alteration. There was one serious adverse event, albeit with complete recovery. CONCLUSION: This postmarketing surveillance study suggests diagnostic efficacy and a favorable clinical safety profile of Gd-DOTA in clinical practice.

Adverse Drug Reaction Reporting Systems↗
PubMed2006

Custom-designed wells and flow chamber for exposing air-liquid interface cultures to wall shear stress.

The effects of mechanical stimuli such as wall shear stresses (WSS) on cellular processes have been studied in vitro in numerous cell types. In order to study WSS effects on cells cultured under air-liquid interface (ALI) conditions, we developed a custom-designed well that can be disassembled into sub-units that allow installation of the cultured cells in a flow chamber, and then, re-assembled for further incubation or biological tests. Human nasal epithelial cells were cultured in the new wells under ALI conditions, and some of their biological characteristics were compared with those cultured in commercial Millicells. The cultured cells from both types of wells secreted the same amount of mucin and had similar cytoskeletal structures. Preliminary WSS experiments demonstrated the advantage of the new wells and provided initial indications that WSS affects the performance of ALI cultured respiratory epithelial cells.

Cell Culture Techniques↗
PubMed2006

The high-mobility-group domain of Sox proteins interacts with DNA-binding domains of many transcription factors.

Sox proteins are widely believed to team up with other transcription factors as partner proteins to perform their many essential functions during development. In this study, yeast two-hybrid screens identified transcription factors as a major group of interacting proteins for Sox8 and Sox10. Interacting transcription factors were very similar for these two group E Sox proteins and included proteins with different types of DNA-binding domains, such as homeodomain proteins, zinc finger proteins, basic helix-loop-helix and leucine zipper proteins. In all cases analyzed, the interaction involved the DNA-binding domain of the transcription factor which directly contacted the C-terminal part of the high-mobility-group (HMG) domain. In particular, the C-terminal tail region behind helix 3 of the HMG domain was shown by mutagenesis to be essential for interaction and transcription factor recruitment. The HMG domain thus not only possesses DNA-binding and DNA-bending but also protein-interacting ability which may be equally important for the architectural function of Sox proteins on their target gene promoters.

Amino Acid Substitution↗
PubMed2006

Safety of iobitridol in the general population and at-risk patients.

The purpose of this study was to review the rate of adverse events after contrast medium administration in the general population and at-risk patients (renal impairment, heart failure (NYHA III or IV), hypotension or hypertension, coronary artery disease, previous reaction to contrast media, asthma and/or allergies, dehydration, diabetes mellitus, poor general condition) under daily practice conditions in a post-marketing surveillance study. Two hundred and ten radiologists conducted various X-ray examinations in 52,057 patients. To document the safety of iobitridol in routine use, all patients undergoing X-ray examinations were included. Exclusion criteria were contraindications listed in the locally approved summary of product characteristics. The adverse event rate was 0.96% (at-risk patients 1.39%); the rate of serious adverse events 0.044% in all patients (at-risk patients 0.057%). Adverse events occurred more often in women than in men (P < 0.001). In patients who had previously reacted to a contrast medium, adverse events were reported in 3.43% with mild to moderate symptoms. In 47.76% of these patients, a premedication was administered. There was no difference in the frequency of adverse events and serious adverse events whether premedicated or not (P = 0.311 and P = 0.295, respectively). Iobitridol was well-tolerated in 99.04% of cases (at-risk patients 98.61%).

Adolescent↗
PubMed2006

Video-assisted mediastinoscopic surgery: clinical feasibility and accuracy of mediastinal lymph node staging.

BACKGROUND: This study was conducted to assess indications, procedures, complications, and clinical feasibility of video-assisted mediastinoscopic surgery (VAMS). It also assessed the accuracy of mediastinal lymph node staging by video-assisted mediastinoscopic lymphadenectomy (VAMLA) with bimanual dissection through the twin-bladed, expanding Linder-Dahan mediastinoscope. METHODS: From 2000 to 2004, we documented and assessed 226 consecutive procedures in a prospective database. RESULTS: A total of 144 VAMLAs for the staging of resectable bronchial carcinoma, and 82 less extensive procedures for other indications were performed, combined with extended mediastinoscopy in 72 patients and with mediastinoscopic sonography in 26. Mean operation time was 54.1 minutes for VAMLA and 36.6 minutes for less extensive procedures. We observed nine complications: five recurrent nerve paralyses, one arterial and two venous injuries, and one mediastinitis. The complication rate was 3.98%, which dropped from 5.3% to 2.6% with growing experience. VAMS detected mediastinal lymph node involvement in 61 (32.8%) of 186 patients with bronchial carcinoma (N2, 45; N3, 16). Mediastinal reassessment at open surgery was done in the 130 resected patients and showed for VAMLA a specificity of 93.75%, a sensitivity of 100%, and a false-negative rate of 0.9%. CONCLUSIONS: In our institutional practice, VAMS has replaced conventional mediastinoscopy for reasons of extended surgical options, safety, precision, education, documentation, and enhanced accuracy of pretherapeutic mediastinal staging. Mediastinal staging of resectable bronchial carcinoma is done by VAMLA, because the accuracy is equal to open lymphadenectomy and the access to the left paratracheal and tracheobronchial lymph nodes is improved. No increase in the complication rate was observed. Prolonged operation time was due to more extended procedures not possible with conventional mediastinoscopy, like VAMLA.

Adolescent↗
PubMed2006

Evaluating the validity of the Voice Handicap Index-10 (VHI-10) among Hebrew speakers.

OBJECTIVE: To evaluate the validity of a translated version of the Voice Handicap Index-10 (VHI-10). STUDY DESIGN AND SETTING: In a parallel group design, 221 patients with different laryngeal pathologies and 172 people with no laryngeal pathology completed a Hebrew version of the VHI-10. Validity and reliability were assessed as well as group differences. RESULTS: Statistical analyses demonstrated high reliability values (Cronbach's Alpha r = 0.949). Responses were not affected by age (P = 0.373) or gender (P = 0.360). The control group received significantly lower scores than all pathological groups (P < 0.05). Within the pathological groups, the "neurogenic" and "mucosa irregularity" groups were rated higher than all other pathological groups (P < 0.05). CONCLUSION: The VHI-10 questionnaire maintains its validity and reliability across translation to Hebrew. Moreover, although the VHI-10 is essentially a unidimensional tool, it provides partial information on the 3 subjective dimensions of the full VHI.

Adolescent↗
PubMed2006

Granular myringitis: Incidence and clinical characteristics.

OBJECTIVE: To examine the incidence and the clinical features of granular myringitis (GM). STUDY DESIGN: A 2-year prospective cohort study. SETTING: A primary otolaryngology clinic affiliated with a tertiary academic referral center. PATIENTS: All-aged patients diagnosed with GM who had no apparent middle ear disease or did not undergo ear surgery. INTERVENTION: Otoscopy and bacteriologic and histopathologic studies. MAIN OUTCOME MEASURES: Granular myringitis was noted in 0.41% of patient's population presenting different forms. RESULTS: Granular myringitis was detected in 26 patients. Recurrent infection occurred in seven (26.9%) and bilateral GM in five patients (19.2%). Perforation of the tympanic membrane (TM) was noted in eight patients (30.7%), six of which closed spontaneously. Otoscopic findings could be classified into three grades: focal de-epithelization (in 10), focal polypoid granulations (in 13), and diffuse polypoid formation over the entire TM (in 3). Histopathologic examination disclosed tiny fragments of granulation tissue infiltrated by nonspecific chronic and acute inflammatory reaction. CONCLUSION: Granular myringitis is encountered not infrequently in primary otolaryngology practice and presented different forms, recurrent episodes, and bilateral involvement. Topical application of antibiotics or caustic agents was successful in all cases. Perforation of the TM may develop and resolve spontaneously during the course of the disease.

Adolescent↗
PubMed2006

Cricotracheal resection for airway reconstruction: The Sheba Medical Center experience.

BACKGROUND: Intubation and tracheostomy are the most common causes of benign acquired airway stenosis. Management varies according to different conceptions and techniques. OBJECTIVES: To review our experience with cricotracheal resection and to assess related pitfalls and complications. METHODS: We examined the records of all patients who underwent CTR in a tertiary referral medical center during the period January 1995 to April 2005. RESULTS: The study included 61 patients (16 women and 45 men) aged 15-81 years. In 17 patients previous interventions had failed, mostly dilatation and T-tube insertion. Complete obstruction was noted in 19 patients and stenosis > 70% in 26. Concomitant lesions included impaired vocal cord mobility (n=8) and tracheo-esophageal fistula (n=5). Cricotracheal anastomosis was performed in 42 patients, thyrotracheal in 12 and tracheotracheal in 7. A staged procedure was planned for quadriplegic patients and for three others with bilateral impaired vocal cord mobility. Restenosis occurred in six patients who were immediately revised with T-tube stenting. Decanulation was eventually achieved in 57 patients (93.4%). Complications occurred in 25 patients, the most common being subcutaneous emphysema (n=5). One patient died of acute myocardial infarction on the 14th postoperative day. CONCLUSIONS: CTR is a relatively safe procedure with a high success rate in primary and revised procedures. A staged procedure should be planned in specific situations, namely, quadriplegics and patients with bilateral impaired vocal cord mobility.

Adolescent↗
PubMed2005

Applying the Voice Handicap Index (VHI) to dysphonic and nondysphonic Hebrew speakers.

OBJECTIVE: To evaluate a translated version of the Voice Handicap Index (VHI) as a diagnostic tool for people with and without a laryngeal pathology, among Hebrew speakers. STUDY DESIGN: Parallel group design. METHODS: The VHI was translated and adapted to Hebrew. The translated version was, then, administered to a group of 182 patients with various laryngeal pathologies and a control group of 171 people with no laryngeal pathology. Based on the participants' responses to the VHI, statistical analyses were, initially, performed to assess validity and reliability, and then to evaluate group differences between the pathological and control groups and among the different pathological groups included in the study. RESULTS: Statistical analyses showed high reliability values of the Hebrew version of the VHI (overall Cronbach's alpha r = 0.976). Participants' scores were not affected by their age (P = 0.156) or gender (P = 0.261). The participants in the control group obtained significantly lower scores on the overall VHI score, as well as on all three subscale scores, in comparison with the pathological group (P < 0.001). In addition, within the pathological group, patients with neurogenic pathologies received higher scores than all other pathological groups, whereas patients with laryngeal inflammation received lower scores than all other pathological groups (P < 0.05). CONCLUSION: The VHI is a powerful tool for quantifying patients' perceptions of their voice handicaps, and it maintained its power across translation. The VHI was shown to be valuable for the assessment of speakers with, as well as without laryngeal pathologies.

Adolescent↗
PubMed2005

An embedded genus-one helicoid.

There exists a properly embedded minimal surface of genus one with a single end asymptotic to the end of the helicoid. This genus-one helicoid is constructed as the limit of a continuous one-parameter family of screw-motion invariant minimal surfaces, also asymptotic to the helicoid, that have genus equal to one in the quotient.

Journal Article↗
PubMed2005

Physical stresses at the air-wall interface of the human nasal cavity during breathing.

The nose is the front line defender of the respiratory system and is rich with mechanoreceptors, thermoreceptors, and nerve endings. A time-dependent computational model of transport through nasal models of a healthy human has been used to analyze the fields of physical stresses that may develop at the air-wall interface of the nasal mucosa. Simulations during quiet breathing revealed wall shear stresses as high as 0.3 Pa in the noselike model and 1.5 Pa in the anatomical model. These values are of the same order of those known to exist in uniform large arteries. The distribution of temperature near the nasal wall at peak inspiration is similar to that of wall shear stresses. The lowest temperatures occur in the vicinity of high stresses due to the narrow passageway in these locations. Time and spatial gradients of these stresses may have functional effects on nasal sensation of airflow and may play a role in the well-being of nasal breathing.

Biomechanical Phenomena↗
PubMed2005

The feasibility of rigid stroboscopy in children.

OBJECTIVE: Voice disorders in children are common but ways of their analysis are limited. We conducted a prospective feasibility study of rigid stroboscopy in children. METHODS: All children referred for voice analysis during the years 2002-2003 were evaluated including subjective perception of voice, voice recording, flexible or rigid laryngoscopy and stroboscopy. Children were prepared by an explanation and visual demonstration. Local anesthesia was introduced through inhalation of Lidocaine (2%) solution prior to examination. Stroboscopy was performed either by a 70 degrees rigid laryngoscope or by a 3.0 mm fiberoptic-flexible endoscope. RESULTS: Forty-two children were analyzed. Rigid stroboscopy was feasible in 31 children of whom 7 were under 10 years of age. Short phonation time (7), gag reflex (6), impaired view due to high and posteriorly inclined epiglottis (4) were the main reasons of failure. CONCLUSIONS: Standard telescopic stroboscopy can be safely and effectively implemented in the majority of children over 10 years of age.

Adolescent↗
PubMed2005

The air-conditioning capacity of the human nose.

The nose is the front line defender of the respiratory system. Unsteady simulations in three-dimensional models have been developed to study transport patterns in the human nose and its overall air-conditioning capacity. The results suggested that the healthy nose can efficiently provide about 90% of the heat and the water fluxes required to condition the ambient inspired air to near alveolar conditions in a variety of environmental conditions and independent of variations in internal structural components. The anatomical replica of the human nose showed the best performance and was able to provide 92% of the heating and 96% of the moisture needed to condition the inspired air to alveolar conditions. A detailed analysis explored the relative contribution of endonasal structural components to the air-conditioning process. During a moderate breathing effort, about 11% reduction in the efficacy of nasal air-conditioning capacity was observed.

Air↗
PubMed2005

Colorectal cancer screening among African-American and white male veterans.

BACKGROUND: Population-based studies from Medicare and privately insured individuals have consistently identified lower rates of colorectal cancer-screening tests among African-American versus white individuals. The purpose of this study was to evaluate whether, at a Veterans Affairs (VA) medical center, similar racial/ethnic differences in colorectal cancer screening could be identified. METHODS: Study participants were male veterans, aged > or =50, attending a general medicine clinic in a VA hospital, who had not had either a fecal occult blood test (FOBT) within the past year or a flexible sigmoidoscopy/colonoscopy within the past 5 years. Based on review of electronic medical records, rates of physician recommendation for FOBT, flexible sigmoidoscopy, or colonoscopy, and patient completion of these tests were obtained and compared by race/ethnicity. RESULTS: Sixty percent of 1599 veterans had not undergone recent colorectal cancer screening. Physicians recommended colorectal screening tests equally among African-American and white patients (71.0% vs 68.2%, p=0.44). African-American patients were 1.3 times more likely than white patients to receive colorectal screening procedures (36.3% vs 28.9%, p=0.03). CONCLUSIONS: In contrast to other settings, in a general medicine clinic at a VA hospital, rates of colorectal cancer-screening tests were not lower for African-American patients compared to white patients.

Black or African American↗
PubMed2005

Anastrazole and oral contraceptives: a novel treatment for endometriosis.

OBJECTIVE: To establish the use of aromatase inhibitors as a therapeutic option for endometriosis. DESIGN: Prospective open-label Food and Drug Administration phase 2 trial with Institutional Review Board approval. SETTING: Outpatient tertiary care centers. PATIENT(S): Fifteen premenopausal patients with documented refractory endometriosis and chronic pelvic pain. INTERVENTION(S): After a 1-month washout of endometriosis hormone therapies, women took 1 mg anastrazole (Arimidex; AstraZeneca, Wilmington, DE) and one tablet of 20 microg ethinyl estradiol/0.1 mg levonorgestrel (Alesse; Wyeth, Madison, NJ) daily for 6 months. MAIN OUTCOME MEASURE(S): An analog pain scale recorded pelvic pain in daily diaries and surveys at baseline and after each treatment month. Side effects, blood counts, liver and renal function tests, cholesterol levels, and bone density were monitored. RESULT(S): Fourteen of 15 patients achieved significant pain reduction. Median pain scores decreased 55% after 6 months, while mean pain scores decreased 40%. Pain reduction comparing each treatment month to baseline achieved statistical significance. Average pain scores began dropping after only 1 treatment month and continued decreasing each additional month. No organ system experienced adverse effects. Estradiol levels were suppressed during treatment. Side effects were mild and improved over time. CONCLUSION(S): Fourteen of 15 patients with refractory endometriosis achieved significant pain relief using anastrazole and 20 microg ethinyl estradiol/0.1 mg levonorgestrel with minimal side effects. This treatment for endometriosis is a promising new modality that warrants further investigation.

Adult↗
PubMed2005

Use of mitomycin C for treatment of keloid: a preliminary report.

OBJECTIVES: Mitomycin C (MC) is an anti-neoplastic agent with an anti-proliferative effect on fibroblasts. We set out to evaluate the effect of MC application following keloid excision. STUDY DESIGN AND SETTING: Patients with keloid in a tertiary referral center were enrolled in a prospective study. The scar was excised and prior to skin closure, a pledget with 1 cc of MC 0.4 mg/mL was applied for 5 minutes. Patient satisfaction and keloid thickness were assessed. RESULTS: All patients were satisfied with the results, although complete disappearance of the keloid was evident only in two. Keloid thickness was measured and ranged from 5 to 26 mm. Following surgery and treatment at 2 months thickness ranged from 0 to 8 mm. CONCLUSIONS: MC application following scar resection appears to be effective in treatment of keloid. SIGNIFICANCE: As no specific effective treatment for keloid is currently available, utilization of this readily available therapeutic agent may improve treatment outcome.

Adolescent↗
PubMed2005

Effects of tracheostomy on well-being and body-image perceptions.

OBJECTIVE: Quality of life after tracheostomy was addressed by measuring its impact on well being and body image perceptions. STUDY DESIGN AND SETTING: A controlled study in a laryngotracheal clinic of a tertiary referral center. Three groups were studied: 24 cannulated, 19 decannulated, and 20 noncannulated patients. They filled up 3 conventional questionnaires. RESULTS: (1) Satisfaction-with-life scale: reduced scores were detected between cannulated and noncannulated patients. (2) Personality traits: neuroticism and extroversion: no differences were noted. (3) Body cathexis scale: both cannulated and decannulated patients scored less than noncannulated. In tracheostomy-specific issues, decannulated patients scored better than cannulated patients. CONCLUSIONS: Reduced scores after tracheostomy indicate an overall diminished quality of life. These changes correlate with personality traits. Decannulated patients exhibited only slight improvement indicating an incomplete psychosocial recovery. SIGNIFICANCE: This is the first report on tracheostomy related quality of life in noncancer patients conducted with specific psychological questionnaires.

Body Image↗