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Biomedical subjects

Ron Eliashar

Publications and source records attributed to Ron Eliashar.

At least 19 recordsLinked to original sources
PubMed2007

Endoscopic surgery for sinonasal invasive aspergillosis in bone marrow transplantation patients.

OBJECTIVES/HYPOTHESIS: Sinonasal invasive aspergillosis (IA) is an aggressive fungal infection with high mortality rates. It commonly develops in immunocompromised patients, often after bone marrow transplantation (BMT). Aggressive surgical debridement by an external approach has been considered a central element of treatment. We describe our experience in endoscopic management of IA in BMT patients in a retrospective study. METHODS: Charts of BMT patients with IA in the past 5 years were reviewed. Demographic data, primary disease, comorbidities, signs and symptoms, blood test results, preparation for surgery, surgical technique, and outcome were recorded. RESULTS: Fourteen BMT patients, age ranging from 3 to 56 years, had sinonasal IA. The primary disease was acute myelogenous leukemia in 6, acute lymphoblastic leukemia in 3, chronic myeloblastic leukemia in one, severe combined immunodeficiency disease in 2, and myelodysplastic syndrome in 2 patients. Diagnosis was made by physical examination, biopsy, culture, and computed tomography scan. Treatment, including aggressive endoscopic debridement, a systemic antifungal medication, and local irrigations of amphotericin-B enabled eradication of IA in all patients. Seven patients required two or more operations. None required orbital exenteration or craniotomy. Six patients died of the primary illness or of comorbidities with no evidence of residual disease. Eight patients are alive. CONCLUSION: Early detection of IA in BMT patients enables aggressive treatment before the disease spreads into the orbit or brain. Proper preoperative preparation facilitates safe endoscopic surgery in patients with severe bleeding tendencies. Although sinonasal IA is lethal, endoscopic surgery is feasible and efficient, enabling excellent local control.

Adult↗
PubMed2006

Laryngeal granular cell tumor.

Granular cell tumor (GCT) of the larynx is an uncommon, benign laryngeal neoplasm. Abrikossoff first described the tumor in 1926 as myoblastoma. The origin of this tumor has been debated in the literature. Most of the authors believe that the tumor is of neural origin due to the characteristic immunohistochemical-staining pattern. The authors describe two cases of laryngeal GCTs located in different sites with a review of the histological and clinical features, the differential diagnosis, and the treatment and the prognosis of the tumor.

Adult↗
PubMed2006

CD48 is an allergen and IL-3-induced activation molecule on eosinophils.

Eosinophils are involved in a variety of allergic, parasitic, malignant, and idiopathic disorders by releasing a variety of factors including specific granule proteins, lipid mediators, and proinflammatory and immunoregulatory cytokines and chemokines. In addition, they interact with various cell types in the inflamed tissue. Yet, the mechanism of eosinophil activation is still poorly understood. Recently, we described the expression and function of the CD2-subfamily of receptors and especially 2B4 on human eosinophils. In this study we focus on CD48, the high-affinity ligand of 2B4. CD48 is a GPI-anchored protein involved in cellular activation, costimulation, and adhesion, but has not been studied on eosinophils. We demonstrate that human eosinophils from atopic asthmatics display enhanced levels of CD48 expression and that IL-3 up-regulates CD48 expression. Furthermore, cross-linking CD48 on human eosinophils triggers release of eosinophil granule proteins. Assessment of CD48 expression in a murine model of experimental asthma revealed that CD48 is induced by allergen challenge and partially regulated by IL-3. Additionally, anti-IL-3 reduces CD48 expression and the degree of airway inflammation. Thus, CD48 is an IL-3-induced activating receptor on eosinophils, likely involved in promoting allergic inflammation.

Allergens↗
PubMed2006

Impact of methionine synthase gene and methylenetetrahydrofolate reductase gene polymorphisms on the risk of sudden sensorineural hearing loss.

Idiopathic sudden sensorineural hearing loss (SSNHL) represents a frequently encountered otological disease of unknown etiology. In recent years, several inherited risk factors have been found in the pathogenesis of vascular diseases. In the present study, we determined whether specific polymorphism or the combination of polymorphisms in folate-dependent homocysteine metabolism genes can act as predisposing inherited vascular risk factors in the development of SSNHL. We conducted a prospective case-control study using DNA samples extracted from 81 patients diagnosed as suffering from SSNHL and 264 healthy control subjects. Three functional polymorphisms were analyzed by polymerase chain reaction amplification, restriction enzyme digestion, and DNA fragment separation by electrophoresis: methylenetetrahydrofolate reductase (MTHFR) C677T, MTHFR A1298C, and methionine synthase (MTR) A2756G polymorphisms. The prevalence of the homozygous genotype of MTR 2756GG in the SSNHL patients (9%) was significantly higher than in the control group (4%) (p = 0.011). The allelic frequency of the G allele of the MTR A2756G polymorphism among SSNHL patients (12.5%) was also significantly higher than in the control group (5%) (p = 0.033). The prevalence of patients possessing two polymorphisms (31%) and three polymorphisms (17%) in the SSNHL group was significantly higher than in the control group (23 and 9%, respectively; p = 0.019). The frequency of patients with a very high rank risk (double homozygous) was significantly higher in the SSNHL group, MTHFR 677TT/MTR 2675GG--7%, than the frequency of patients in the control group, MTHFR 677TT/MTR 2675GG--3% (p = 0.030). Certain polymorphisms in genes encoding enzymes in the folate-dependent homocysteine metabolism are associated with SSNHL. In our case-control study, a significant association between MTR 2756GG genotype and SSNHL was found which may represent an inherited vascular risk factor in the pathogenesis of SSNHL.

5-Methyltetrahydrofolate-Homocysteine S-Methyltran↗
PubMed2006

Packing in endoscopic sinus surgery: is it really required?

OBJECTIVE: The aim of this study was to evaluate the routine use of packing or local hemostatic agents in endoscopic sinus surgery (ESS). METHODS: Packing and/or hemostatic agents were used only when necessary in 100 consecutive adult ESS patients in a tertiary academic hospital. Necessity for packing the nose after excessive bleeding was analyzed in relation to demographic characteristics, medical history, previous surgeries, current surgical procedure, type of anesthesia, and amount of intraoperative bleeding. RESULTS: Three patients who required packing because of other reasons (such as bolstering of mucosa) were excluded from the study. The remaining 97 patients included 61 males and 36 females between the ages of 16 to 86 (mean 44). Forty-nine patients underwent only ESS, 40 ESSs associated with nasal polypectomy, and 8 underwent other endoscopic procedures. Fifty-four underwent the operation under general anesthesia and 43 under local anesthesia. Intraoperative blood loss was less than 30 mL in 82 patients (85%), 30 to 50 mL in 11 (11%), and more than 50 mL in 4 (4%). In 89 patients (92%), packing or a hemostatic agent was not used. No patient had bleeding complications postoperatively. A comparison between patients who required packing to those who did not showed that the only statistically significant associations related to general anesthesia (P = 0.0082) and to the amount of intraoperative bleeding (P < 0.001). CONCLUSIONS: Most ESS procedures can be managed without packing or any other hemostatic measures. Local anesthesia, use of local vasoconstrictors, and careful operative technique minimize the need for nose packing, thus reducing patient's discomfort, postoperative complications, and cost of surgery.

Adolescent↗
PubMed2006

Ingestion of caustic substances: a 15-year experience.

OBJECTIVE: The objective of this study was to analyze the circumstance, demographic features, clinical findings, and complications of caustic ingestion in relation to the type and amount of caustic substance. STUDY DESIGN: The authors conducted a retrospective cohort study in a tertiary medical center. METHODS: The authors reviewed medical records from 1988 to 2003 of patients with a history of caustic ingestion and clinical signs of injury to the aerodigestive tract. Parameters examined included age at presentation, gender, demographic status, nature of the caustic substance ingested, amount of substance, circumstance of the event, diagnostic tools, degree of injury, and anatomic distribution of the injury, early and late complications, and requirement for ventilatory support. RESULTS: A total of 50 cases of caustic ingestion were identified (age range, 5 months-71 years). A biphasic distribution of the patients was noted; half were children under 5 years old and the remainder was adults. The most common caustic agent ingested was alkaline (42%) followed by acidic (32%) and chlorine bleach (26%). The most frequent cause for ingestion was accidental (67%) as opposed to attempt suicide (33%). All cases of attempted suicide occurred in adults. Most of them reported ingestion of large amounts of caustic substance. In the pediatric group, an association between the caustic agent and ethnicity was observed. Among Jewish children, alkaline cleaning agents were the most common cause (82%). Acetic acid was the most common substance ingested by the Arab children (100%). The findings of rigid esophagoscopy in 36 patients were as follows: first-degree esophageal injury in 16 (44%), second-degree in 6 (17%), third-degree in 7 (19%), fourth-degree in 6 (17%), and one (3%) was normal. Mucosal injury to the esophagus was worse in the acidic ingestion group as compared with the alkaline substance ingestion group with marginally statistically significant difference in the median degree of injury between the three types of ingested substances (P = .054). Mucosal injury to the esophagus was worse among patients who attempted suicide as compared with accidental ingestion with a statistically significant difference in the median degree of injury between the two reasons for ingestion (P = .002). CONCLUSION: Severity of injury from caustic ingestion damages depend on the type of ingested substance, which varies depending on ethnicity. Ingestion of caustic agents by children involves specific substances according to the season, cultural and religious festivals, and ethnicity. The majority of adult cases are intentional with more serious injuries and a higher rate of complications. In our series, ingestion of acidic substances and ingestion associated with suicide attempt had the most severe consequences.

Accidents↗
PubMed2006

Redefining parapharyngeal space infections.

OBJECTIVES: Our intent was to review the clinical signs, computed tomography (CT) scans, treatment, and outcome of parapharyngeal space infections (PPIs), and to define 2 types of infections of the parapharyngeal space (PPS) according to the location of the infectious process. METHODS: We performed a retrospective analysis of patients hospitalized in a tertiary university hospital with a diagnosis of PPI, abscess, or deep neck abscess between 1988 and 2004. Files and CT scans were reviewed after classification into 2 groups: 1) infection located in the posterior part of the PPS (PostPPI); and 2) infection located in the anterior part of the PPS (AntPPI). RESULTS: Twenty-two patients had a PostPPI; their ages ranged from 10 months to 24 years. Five patients underwent surgical drainage, and 17 others were treated solely with intravenous antibiotic therapy. No pus was found during surgery in 2 patients. The average time of hospitalization was 10 days. Only 1 complication (aspiration pneumonia) was observed. Seven patients had an AntPPI; their ages ranged from 1.5 years to 65 years. All patients underwent surgical drainage, and pus was detected in all cases. The average time of hospitalization was 35 days. Complications (septic shock, respiratory arrest, mediastinitis, pleural empyema, pericarditis) were observed in 4 patients. CONCLUSIONS: The term "parapharyngeal abscess" was assigned long before the CT scan era, and was based on physical examination and plain film radiology. In essence, the entity PPS "abscess" or "infection" is composed of 2 different disorders. Infection located in the posterior part of the PPS with no invasion into the parapharyngeal fat and with no extension into other cervical spaces except the adjacent retropharyngeal space may be termed posterior parapharyngeal infection or parapharyngeal lymphadenitis. This is a relatively benign condition, and nonsurgical treatment should be considered. Infection involving the parapharyngeal fat may be termed parapharyngeal abscess or deep neck abscess. Diffusion into the mediastinum and other severe complications are frequent. Urgent surgical drainage is therefore mandatory.

Abscess↗
PubMed2006

Halofuginone prevents subglottic stenosis in a canine model.

OBJECTIVES: Halofuginone is a low-molecular weight quinazolinone alkaloid coccidiostat that inhibits collagen type I synthesis, extracellular matrix deposition, and angiogenesis. This study was conducted to assess its potential in preventing subglottic stenosis (SGS). METHODS: We induced SGS in 10 dogs randomly divided into 2 groups. Each group received treatment between 3 days before and 21 days after the induction of SGS. One group received oral halofuginone 40 microg/kg, and the other was given placebo. The area of the subglottic lumen was measured at baseline and 3 months later. In addition, human tracheal fibroblasts were cultured. The inhibitory effect of halofuginone was compared to the effect of mitomycin. RESULTS: All dogs survived throughout the study with no side effects. Three months after the operation, no halofuginone-treated dog had SGS, in contrast to a 66% to 80% stenosis rate (mean, 72%) in controls (p < .008). Thick fibrotic tissue was found in the placebo-treated larynges, whereas an almost normal architecture was observed in halofuginone-treated larynges. Halofuginone inhibited the growth of human tracheal fibroblasts by 75%, in comparison with 60% inhibition by mitomycin (no statistically significant difference). CONCLUSIONS: This preliminary study shows that halofuginone is effective in preventing SGS caused by an acute injury. Halofuginone has a potential therapeutic role in preventing SGS in humans.

Animals↗
PubMed2006

Acute external laryngotracheal trauma: diagnosis and management.

Laryngotracheal trauma may result in lifelong complications or even death if diagnosis or treatment is delayed. Emergency room physicians, trauma surgeons, anesthesiologists, and especially otolaryngologists should maintain a high level of awareness of and suspicion for laryngotracheal trauma whenever a patient presents with multiple trauma in general or with cervical trauma in particular. Although there is some controversy regarding care, treatment in experienced hands will usually result in a favorable outcome. In this article, we review and update the diagnosis and management of acute external laryngotracheal trauma.

Airway Obstruction↗
PubMed2005

The inhibitory receptor IRp60 (CD300a) suppresses the effects of IL-5, GM-CSF, and eotaxin on human peripheral blood eosinophils.

Allergic, inflammatory, and immune responses carried out by eosinophils are regulated by the cross talk between activatory and inhibitory signals. While much data has been obtained on activatory signals, inhibitory receptors on these cells have received scant attention. Therefore, we screened the surface of human peripheral blood eosinophils for inhibitory receptors using monoclonal antibodies (mAbs) previously generated to recognize receptors on human natural killer cells. Eosinophils from all of the donors examined expressed the inhibitory receptors IRp60, LIR3/ILT5, FcgammaRIIB, and p75/AIRM but not LIR1/ILT2, p58.1, p58.2, p70, or NKG2A/CD94 (n = 15). Interestingly, 25% of the donors expressed p140. IRp60 cross-linking inhibited eotaxin-dependent transmigration of eosinophils in a calcium-independent fashion. In addition, cross-linking of IRp60 on the eosinophils in the presence of IL-5/GM-CSF inhibited the antiapoptotic effect of these cytokines and blocked the release of TNF-alpha, IL-1beta, IFN-gamma, IL-4, and 3T3 fibroblast proliferation. Cross-linking of IRp60 inhibited IL-5-mediated JAK2 phosphorylation as well as eotaxin- and IL-5/GM-CSF-mediated ERK1/2 and p38 phosphorylation. Furthermore, upon cross-linking, IRp60 underwent tyrosine phosphorylation and recruited SHP-1 but not SHP-2. These findings demonstrate a novel pathway for suppressing the activity of human eosinophils, thus indicating IRp60 as a future potential target for the treatment of allergic and eosinophil-associated diseases.

3T3 Cells↗
PubMed2005

A new surgical technique for primary closure of long-term tracheostomy.

OBJECTIVES: To delineate a technique that avoids the complications associated with surgical closure of long-term or permanent tracheostomy (LTT). Study design A case series that describes the technique and clinical outcomes. METHODS: Thirty-seven of 300 patients with a previously established LTT underwent primary surgical closure of their stoma after their underlying disease had been resolved. The surgical technique combined a turnover flap with medialization of fibroadipose tissue, followed by additional closure with an advancement skin flap. RESULTS: After a mean follow-up of 3.2 years, no patient developed major complications. Four patients developed minor complications, which responded to conservative treatment. In all patients, the functional results were satisfactory, as were the cosmetic results, with the exception of 1 case. None required re-tracheostomy. CONCLUSION AND SIGNIFICANCE: This simple and reliable new surgical technique for closing LTT avoids the potential failures and complications encountered in previously published procedures.

Follow-Up Studies↗
PubMed2005

Michel's aplasia.

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Ear, Inner↗
PubMed2005

The role of the eosinophil in nasal diseases.

PURPOSE OF REVIEW: The eosinophil is involved in physiologic and pathologic processes, such as asthma, parasitic diseases, granulomatous disorders, fibrosis, malignant tumors and several sino-nasal diseases. RECENT DEVELOPMENTS: Recent data on the structure and function of the eosinophil provides additional information regarding the pathophysiology and the treatment options of these diseases. In this paper the most recently acquired data on the role of the eosinophil in allergic rhinitis (with or without bronchial asthma), chronic sinusitis (with or without nasal polyposis) and allergic fungal sinusitis are reviewed. SUMMARY: The data provides evidence regarding the pivotal role of the eosinophil in sino-nasal diseases. Possible ways to target the eosinophils are discussed.

Environmental Pollution↗