Comparative analysis of preoperative diagnostic values of HRCT and CBCT in patients with histologically diagnosed otosclerotic stapes footplates.

This prospective case review was performed with the aim to compare and asses the diagnostic values of cone-beam computed tomography (CBCT) and high-resolution computed tomography (HRCT) in the preoperative evaluation of otosclerosis. A total of 43 patients with histologically confirmed stapedial otosclerosis, who underwent unilateral stapedectomies were analyzed. Preoperative temporal bone CBCT and HRCT scans were performed in all cases. Both CBCT and HRCT imaging were characterized by a slice thickness of 0.4-0.625 mm and multiplanar image reconstruction. Histopathologic examination of the removed stapes footplates was performed in all cases. Findings of CBCT and HRCT were categorized according to the modified Marshall's grading system (fenestral or retrofenestral lesions). Histopathologic results were correlated with multiplanar reconstructed CBCT and HRCT scans, respectively. Negative control groups for CBCT (n = 36) and HRCT (n = 27) examinations consisted of patients, who underwent CBCT imaging due to various dental disorders or HRCT analysis due to idiopathic sudden sensorineural hearing loss. Histologically active foci of otosclerosis (n = 31, 72 %) were identified by both CBCT and HRCT in all cases with a sensitivity of 100 %. However, CBCT could not detect histologically inactive otosclerosis (n = 12, 23 %; sensitivity 0 %). In contrast, HRCT showed inactive otosclerosis with a sensitivity of 59.3 %. According to CBCT results, no retrofenestral lesions were found and the overall sensitivity for hypodense lesions was 61.37 %. In conclusion, CBCT is a robust imaging method in the detection of histologically active fenestral hypodense foci of otosclerosis with high sensitivity and radiologic specificity. In the light of these results, HRCT still remains the basic imaging method in the preoperative diagnosis of otosclerosis, since it has much greater sensitivity and specificity in the detection of retrofenestral hypodense lesions and histologically inactive otosclerotic foci in the oval window niche.

Effects of intranasal steroid treatment on the presence of biofilms in non-allergic patients with chronic rhinosinusitis with nasal polyposis.

Microbial biofilms have been implicated in the pathogenesis of chronic rhinosinusitis with nasal polyposis (CRSwNP). Intranasal application of corticosteroids (INCS) is a reliable option in the management of CRSwNP. INCS medication has been suspected to influence the presence and thickness of microbial biofilms and inflammatory cell patterns in CRSwNP. Two series of identical nasal polyps obtained from non-allergic patients with CRSwNP (n = 56), who underwent endoscopic sinus surgery (ESS), were processed to hematoxylin-eosin (H.E.) and Gram staining, respectively. Patients were recruited into three groups. Group A (n = 21) consisted of patients with continuous preoperative INCS treatment. In group B (n = 17), patients were never treated by INCS, while in group C (n = 18) INCS medication was stopped at least 6 months before ESS. Biofilm positivity varied from 76.4 to 88.8% in different subject groups. These values and average thickness of biofilms did not reach statistically significant levels (Mann-Whitney's U probe, p > 0.05) in different patient groups. In contrast, microscopic pattern and numbers of predominant inflammatory cell populations displayed obvious differences according to INCS treatment (Mann-Whitney's U probe, p < 0.001). According to these observations, INCS treatment does not affect the presence and thickness of microbial biofilms in CRSwNP. In contrast, it has significant effects on the pattern of inflammatory cells infiltrating the subepithelial layer, which might result in beneficially altered extracellular matrix production and cytokine release.

Diagnostic value of cone-beam CT in histologically confirmed otosclerosis.

This retrospective case review was performed with the aim to asses the value of cone-beam computed tomography (CBCT) in the preoperative diagnosis of otosclerosis. A total of 32 patients with histologically confirmed stapedial otosclerosis, who underwent unilateral stapedectomies were analyzed. Preoperative temporal bone CBCT scans were performed in all cases. CBCT imaging was characterized by a slice thickness of 0.3 mm and multiplanar image reconstruction. Histopathologic examination of the removed stapes footplates was performed in all cases. Findings of CBCT were categorized according to Marshall's grading system (from grade 0 to grade 3). Histopathologic results were correlated to multiplanar reconstructed CBCT scans, respectively. Histologically active foci of otosclerosis (n = 21) were identified by CBCT in all cases with a sensitivity of 100 %. However, CBCT was unable to detect histologically inactive otosclerosis (n = 11, sensitivity = 0 %). According to CBCT scans, no retrofenestral lesions were found and all positive cases were recruited into the grade 1 group indicating solely fenestral lesions at the anterior pole of stapes footplates. In conclusion, CBCT is a reliable imaging method with considerably lower radiation dose than high-resolution CT (HRCT) in the preoperative diagnosis of otosclerosis. These results indicate that CBCT has high sensitivity and specificity in the detection of hypodense lesions due to histologically active otosclerosis.

Primary tuberculosis of the middle ear cleft: diagnostic and therapeutic considerations.

Tuberculosis remains one of the most challenging infectious diseases, which rarely manifests in the middle ear cleft exclusively. Typical symptoms of tuberculosis have become more and more confusing due to the genetic evolution of different Mycobacterium species. In the diagnosis of tuberculous otitis media (TOM), clinical suspicion plays a fundamental role, when topical and/or systemic antibiotic treatment cannot lead to improvement in ear discharge and inflammation. If there is no other reason of persisting otorrhea, microbiological sampling and culturing are the subsequent steps of diagnosis. These investigations, however, have low sensitivity; therefore a canal wall-up mastoidectomy is recommended, which includes the removal of necrotic bone and multiple histological sampling from various locations. Currently, histopathological analysis is the most robust and reliable method in the diagnosis of TOM. Tuberculin skin test, Mycobacterium-specific PCR and interferon-gamma release assay cannot distinguish between active, inactive or post-infective conditions. According to these considerations, these methods may serve as supplementary assays for the final diagnosis. Having the appropriate diagnosis after surgical intervention and laboratory analysis, medical management should be continued by anti-tuberculosis chemotherapy. Hereby, we demonstrate two cases with primary TOM and provide an overview of the literature in the light of diagnostic and therapeutic guidelines in the management of TOM.

The presence of CD209 expressing dendritic cells correlates with biofilm positivity in chronic rhinosinusitis with nasal polyposis.

Biofilm-positive cases of chronic rhinosinusitis with nasal polyposis (CRSwNP) may form a separate clinical entity, which is characterized by high recurrence rates and resistance against different therapeutic strategies. This can be explained by a special immunologic phenotype. Biofilm existence has been supposed to correlate with increased amount of dendritic cells that are responsible for antigen presentation in CRSwNP. A total of 20 patients with CRSwNP undergoing endoscopic sinus surgery (ESS) were analyzed. The negative control group consisted of ten patients undergoing septoplasty without CRSwNP. Three series of individual nasal polyps and control specimens were processed to hematoxylin-eosin (HE) and Gram staining and to CD209-specific immunofluorescent assay, respectively. Biofilm was detected in 13 of 20 patients (65 %) with CRSwNP and in none of the ten negative controls. The subepithelial layer of biofilm-positive nasal polyps displayed a statistically significant (p < 0.001) increase in the numbers of CD209-expressing dendritic cells compared to biofilm-negative specimens. It was found that biofilm detectability showed strong correlation to the architecture of respiratory mucosa and to the dominant inflammatory cell type of the subepithelial layer. Persisting bacterial biofilms may affect the type of antigen presentation and consecutive immune reactions in the subepithelial layer of nasal mucosa. This phenomenon may result in different inflammatory pathways with specific cytokine profile compared to biofilm-negative cases. Co-existence of bacterial biofilms and dominant pattern of dendritic cells suggest a biofilm-associated immunologic phenotype in CRSwNP. This can explain the mucosal changes, functional disorders and therapy resistance featuring CRSwNP.

Optical coherence tomography for biofilm detection in chronic rhinosinusitis with nasal polyposis.

Chronic rhinosinusitis with nasal polyposis (CRSwNP) is a multifactorial disease that seems to be associated with the presence of microbial biofilms and corresponding subepithelial inflammatory reactions. Optical coherence tomography (OCT) might be applied to detect bacterial and fungal biofilms in patients with CRSwNP. A total of 27 patients with CRSwNP undergoing endoscopic sinus surgery (ESS) were analyzed. The negative control group consisted of six patients undergoing septoplasty for nasal obstruction without CRSwNP. The nasal polyps and inferior turbinate mucosa specimens applied as negative controls were processed to OCT analysis and H.E. and Gram staining. Biofilm was detected in 22 of 27 patients (81.5 %) with CRSwNP and in none of six negative controls. In our series, OCT scan showed an obvious association with the findings of H.E. and Gram staining and was allocated to be a good predictor of biofilm existence. On OCT images, biofilms were displayed as distinct superficial layers with high optical density. It was found that microscopic architecture of biofilms was strongly associated with the integrity of nasal mucosa and to the cellular pattern of subepithelial inflammatory reaction. This study confirmed the presence of microbial biofilms in patients with CRSwNP according to OCT scans and histological analysis. Since biofilms may affect the severity and recurrence rate of CRS treated by ESS they should be detected preoperatively. In conclusion, single application of OCT analysis or combination with conventional histological protocols provides a robust and reliable method for the detection of bacterial and fungal biofilms in CRSwNP. Level of evidence 3b, individual case-control study.

Perspectives of pharmacological treatment in otosclerosis.

To review our current knowledge of the pathologic bone metabolism in otosclerosis and to discuss the possibilities of non-surgical, pharmacological intervention. Otosclerosis has been suspected to be associated with defective measles virus infection, local inflammation and consecutive bone deterioration in the human otic capsule. In the early stages of otosclerosis, different pharmacological agents may delay the progression or prevent further deterioration of the disease and consecutive hearing loss. Although effective anti-osteoporotic drugs have become available, the use of sodium fluoride and bisphosphonates in otosclerosis has not yet been successful. Bioflavonoids may relieve tinnitus due to otosclerosis, but there is no data available on long-term application and effects on sensorineural hearing loss. In the initial inflammatory phase, corticosteroids or non-steroidal anti-inflammatory drugs may be effective; however, extended systemic application may lead to serious side effects. Vitamin D administration may have effects on the pathological bone loss, as well as on inflammation. No information has been reported on the use of immunosuppressive drugs. Anti-cytokine targeted biological therapy, however, may be feasible. Indeed, one study on the local administration of infliximab has been reported. Potential targets of future therapy may include osteoprotegerin, RANK ligand, cathepsins and also the Wnt-ß-catenin pathway. Finally, anti-measles vaccination may delay the progression of the disease and potentially decrease the number of new cases. In conclusion, stapes surgery remains to be widely accepted treatment of conductive hearing loss due to otosclerosis. Due to lack of solid evidence, the place of pharmacological treatment targeting inflammation and bone metabolism needs to be determined by future studies.

Controversies in RELN/reelin expression in otosclerosis.

Several studies have reported a potential genetic association between disease-specific single nucleotide polymorphism (SNPs) of RELN and otosclerosis and confirmed RELN expression in human stapes footplates. These are conflicting results, since RELN expression has been attributed exclusively to neural tissues and to odontoblasts. Otosclerosis is a disease of complex bone remodeling disorder, which is limited to the human otic capsule. Genetic predisposition has long been suspected, however, the pathogenesis remained unclear. Ankylotic stapes footplates (n = 85), cortical bone fragments (n = 4), hearing ossicles (n = 2) and human brain tissue specimens (n = 4) were processed to RELN-specific RT-PCR and reelin-specific immunofluorescent assay (IFA). The first group of ankylotic stapes footplates (n = 22) showed a consistent positive reaction against reelin by IFA; however, RELN-specific mRNA could not be detected in the second, RT-PCR group (n = 63). Brain specimens were characterized by robust expression of reelin (n = 2) and RELN-specific mRNA (n = 2). In case of bone-specific controls (n = 6), reelin/RELN expression was excluded obviously. Concerning current observations, RELN gene does not show active expression in adult stapes footplates. Since, the otic capsule surrounds a special neural structure (membranous labyrinth), reelin might play a coordinative role in the early embryonic stage of development. As being a part of the otic capsule, stapes footplate might be characterized by persisting reelin detectability without mRNA expression. Between these conditions, the etiologic role of RELN is questionable in the pathogenesis of otosclerosis.

No evidence for disturbed COL1A1 and A2 expression in otosclerosis.

Otosclerosis is a complex bone remodeling disorder of the human otic capsule that might be associated with various mutations of A1 and A2 alleles of type-I collagen. The study herein presented, investigates the possibilty of the genetic involvement of type-I collagen in the pathogenesis of histologically confirmed otosclerosis. A total of 55 ankylotic stapes footplates were analyzed. Cortical bone fragments (n = 30), incus (n = 3) and malleus (n = 2) specimens were employed as negative controls. Specimens were divided into two groups. The first group was processed using conventional H.E. hematoxylin-eosin (H.E.) staining and type-I collagen-specific immunofluorescent assay (IFA), while the second group was examined by COL1A1 and A2-specific RT-PCR. Otosclerotic- (n = 31) and non-otosclerotic stapes footplates (n = 9) as well as cortical bones (n = 20), incus (n = 2) and malleus specimens (n = 1) showed normal and quite similar A1 and A2 allele expression confirmed by IFA. RT-PCR analysis revealed normal and consistent mRNA expression of both alleles in each specimen. Expression levels and patterns of COL1A1/A2 alleles did not show significant correlation with the histological diagnosis of otosclerosis. Type-I collagen is a highly conserved structure protein, which plays a fundamental role in the integritiy of various connective tissues. Mutations of A1 and A2 alleles result in serious systemic disorders of the skeleton, tendons and skin. Since otosclerosis is an organ-specific disease, it is difficult to explain its genetic association with type-I collagen. In conclusion, we found no evidence supporting the putative link of COL1A1 and COL1A2 alleles with otosclerosis.

Biofilm detection in chronic rhinosinusitis by combined application of hematoxylin-eosin and gram staining.

The pathomechanism of chronic rhinosinusitis with nasal polyposis (CRS/NP) seems to be unclear. Bacterial-, fungal- and combined biofilms might play a potential role in the pathogenesis of various inflammatory diseases and recently in CRS/NP. A prospective, blinded observational study was performed to confirm that the combination of conventional hematoxylin-eosin (HE) and Gram staining protocols could be used to detect bacterial and fungal biofilms in patients with CRS/NP. A total of 50 patients with CRS/NP undergoing endoscopic sinus surgery (ESS) were analyzed. The negative control group consisted of 12 patients undergoing septoplasty for nasal obstruction without CRS/NP. The nasal polyps and inferior turbinate mucosa specimens applied as negative controls were processed to HE and Gram staining. Biofilm was detected in 44 of 50 patients with CRS/NP and in none of 12 negative controls. In our series, HE method showed an obvious correlation with the results of Gram staining and was allocated to be a good predictor of biofilm existence. It was found that the microscopic structure and thickness of biofilms were strongly associated with the integrity of nasal mucosa and with the characteristics of subepithelial cellular infiltration. This study confirmed the presence of bacterial and fungal biofilms on the surface of NPs obtained from patients with CRS. Since biofilms may affect the severity and recurrence rate of CRS treated by ESS they should be detected histologically. In conclusion, HE staining combined with Gram protocol is a robust and reliable method for the detection of bacterial and fungal biofilms in CRS/NP.

Osteoprotegerin expression and sensitivity in otosclerosis with different histological activity.

Otosclerosis is a complex bone dystrophy of the human otic capsule leading to conductive and sensorineural hearing loss. Since otosclerosis may, at least in part, be considered as an autoimmune-inflammatory disease, disturbed balance of TNF-alpha and osteoprotegerin (OPG) expression has been implicated in the pathological bone remodeling. It has been supposed that active otosclerosis is characterized by decreased or missing local OPG production with invariable OPG sensitivity of the otosclerotic foci. Ankylotic stapes footplates (n = 41) removed by stapedectomy were processed to histological examination, OPG-specific RT-PCR, tissue culturing and alkaline-phosphatase (AP) activity assessment, respectively. OPG concentration of serum specimens (n = 41) was measured by ELISA. Cortical bone fragments harvested from the external ear canal were used as negative controls of otosclerosis. Among 41 ankylotic stapes footplates, 22 active and 19 inactive otosclerosis cases were histologically diagnosed. OPG expression was significantly lower (p < 0.001) in active otosclerosis compared to inactive cases. Osteoclast cultures originated from active otosclerotic foci showed a considerable susceptibility against external OPG dosage, which resulted in a significant decrease of AP activity (p < 0.001). In contrast, OPG serum levels were in the normal range (5-100 ng/ml) indicating a non-systemic bone resorption. In conclusion, secondary decreased local OPG production might play an important role in the pathogenesis of otosclerotic bone remodeling disorder. As to previous and current results, decreased OPG sensitivity of lesion-forming cells should be excluded. These observations may indicate the potential role of recombinant OPG treatment in early stages of otosclerosis.

Etiopathogenesis of otosclerosis.

The objectives of our study was to review our current knowledge of the etiopathogenesis of otosclerotic bone remodeling including genetics, viral infection, autoimmunity and inflammation and to discuss disease pathogenesis with relevance to pharmacotherapy. Relevant publications on the etiopathogenesis, molecular biology, genetics and histopathology of otosclerosis from 1984 to 2009 were analyzed. Otosclerosis is a bone remodeling disorder of the human otic capsule; however, the etiopathogenesis remains unclear. Genetic predisposition, disturbed bone metabolism, persistent measles virus infection, autoimmunity, and hormonal and environmental factors also may play contributing roles in the pathogenesis of otosclerosis. Since diagnosis of otosclerosis is still based on histopathological examination of the removed stapes footplate, systemic prospective studies based on comprehensive histopathological and molecular biological analysis are necessary to obtain further information on the background of the disease.

Restriction analysis of otosclerosis-associated CD46 splicing variants.

Otosclerosis is a primary bone remodeling disorder of the human otic capsule and is associated with persistent measles virus infection. The human cellular receptor of measles virus is the membrane cofactor protein (MCP, CD46), which has 14 well-described splicing variants. Unique CD46 expression pattern of the otic capsule and the stapes footplate may determine the susceptibility for persistent measles virus infection. A total of 51 surgically removed ankylotic stapes footplates were analyzed by histopathological and molecular biological methods, respectively. Nucleic acids were extracted. Measles virus sequences were detected by nucleoprotein RNA-specific reverse transcriptase polymerase chain reaction (RT-PCR). Alternatively spliced RNA of CD46 isoforms was amplified by RT-PCR; cDNA amplimers were separated by SDS poly-acrylamide gel electrophoresis and were purified from the gel. Complementary DNA of CD46 isoforms was restricted by endonuclease enzymes having CD46-specific recognition sites. The presence of viral RNA was associated exclusively with the histopathological diagnosis of otosclerosis; the stapes specimens with negative measles virus belonged to non-otosclerotic stapes fixations. All specimens (N = 51) were characterized by the consecutive expression of five CD46 variants (c, d, e, f and one shorter unidentified isoform). Histologically confirmed ostosclerotic specimens (N = 21) were characterized by increased expression levels of variant "f" and the unknown isoform. Increased expression levels of these isoforms and special CD46 expression pattern of the human otic capsule might produce modified or pathological intracellular signalization that could create the possibility of persistent measles virus infection.

Otosclerosis: an organ-specific inflammatory disease with sensorineural hearing loss.

Otosclerosis is an inflammatory disease associated with persistent measles virus (MV) infection of the otic capsule. The nature of sensorineural hearing loss (SNHL) related to otosclerosis can be due to the chronic TNF-alpha release from the foci. TNF-alpha enters the inner ear fluid spaces in histologically active stages of otosclerosis and may cause outer hair cell functional disorder and subsequent SNHL without morphological changes of the organ of Corti. On the contrary, non-otosclerotic stapes ankylosis being a non-inflammatory disease is not harmful for hair cells. Theoretically, SNHL should not associate to this type of stapes fixation. Stapes footplates (N = 248) were examined by hematoxylin-eosin staining and corresponding MV-, OPG- and TNF-alpha-specific RT-PCR. Anti-measles IgG levels of serum specimens were measured by ELISA. Preoperative audiological results were correlated with otosclerotic and non-otosclerotic histopathologies. Among patients with stapes fixation, we found 93 active and 67 inactive otosclerosis, and 88 non-otosclerotic stapes ankylosis. MV could only be detected in otosclerotic stapes footplates. Audiometry revealed bone conduction threshold elevation toward the high frequencies in otosclerotic patients, which was associated to the duration of hearing loss. OPG mRNA expression was significantly lower in the TNF-alpha positive specimens, which was independent from virus positivity. In about one-third of stapes fixations, the etiology is non-otosclerotic stapes ankylosis. Histologic otosclerosis exhibits a strong correlation with MV presence in the bone as a sign of persistent MV infection and related inflammation with TNF-alpha release. This causes SNHL in the function of time. Non-otosclerotic stapes fixations do not cause high-frequency SNHL.

Follow-up of HPV DNA copy number in cidofovir therapy of recurrent respiratory papillomatosis.

BACKGROUND: Cidofovir is a cytosine nucleoside analogue antiviral drug given as an adjuvant therapy in recurrent respiratory papillomatosis (RRP). MATERIALS AND METHODS: Intralesional cidofovir therapy was given to a 14-year-old male patient. The papilloma severity score (PSS) of Derkay et al. was used for follow-up. Serial fresh-frozen biopsies were taken from the lesions in the larynx and soft palate prior to therapy and during its course. After human papillomavirus (HPV) typing and the determination of the genomic physical state, the HPV DNA copy number was estimated with real-time PCR. RESULTS: All the papillomas harboured HPV 11 DNA in episomal form. Prior to therapy, the HPV copy number fluctuated with time. In the initial treatment period with 2-week-intervals both the viral load and the PSS decreased and a transient complete remission was observed. Subsequently, when the injections were given at longer intervals, the viral load returned to the initial values or greated, fluctuations reappeared and the RRP recurred at a controlled rate. CONCLUSION: The initial treatment period was successful, as the viral load decreased, and long-term effects of cidofovir might account for the controlled disease as the injection intervals were prolonged.

Chromosomal imbalances are associated with increased proliferation and might contribute to bone destruction in cholesteatoma.

OBJECTIVES: Our aim was to evaluate the copy number alterations of chromosomes 3, 7, 8, and 17 in middle ear cholesteatomas and define the association between the rate of cell proliferation and chromosome number changes. METHODS: Tissues were obtained from 16 patients. Fluorescence in situ hybridization was performed on tumor imprint preparations. Cell proliferation was characterized with Ki-67 monoclonal antibody on cholesteatoma samples and on postauricular skins as control. RESULTS: Different degrees of aneusomy were found for all chromosomes except for chromosome 3. Chromosome copy number alterations were associated with elevated proliferative rate and related also with the aggressiveness of the lesions. CONCLUSIONS: Based on our results, we assume that aneusomy of chromosomes 7, 8, and 17 might play an important role during invasion of the adjacent bony structures of cholesteatoma, as well as associate with increased cell proliferation activity, which might lead to the aggressive behavior of the tissue.

Analysis of KRT1, KRT10, KRT19, TP53 and MMP9 expression in pediatric and adult cholesteatoma.

Cholesteatoma is an epidermal cyst with still unknown pathomechanism. The aim of the current study was to investigate molecular differences in the background of the hyperproliferative property and aggressive behavior typical of the cholesteatoma epithelium. The expression of three cytokeratin genes (KRT1, KRT10 and KRT19), the matrix metalloproteinase 9 gene (MMP9) and the tumor suppressor TP53 gene was measured by qRT-PCR in surgical samples of pediatric and adult cholesteatoma cases and their expression level was compared to that of normal skin samples from the retroauricular region of control individuals. Cholesteatoma samples were stratified according to the age of onset and recurrence for more detailed analysis. Our results showed identical expression pattern for KRT1 and KRT10, their expression was higher in pediatric cases than in adults, especially in pediatric recurrent samples. The expression level of KRT19 was inversely proportional to that of KRT1/KRT10, it was lower in the more invasive recurrent cases both in our pediatric and adult groups. As it was expected from the bone destructive behavior of cholesteatoma, a significantly elevated expression of MMP9 was measured in cholesteatoma samples, the highest level was found in adult recurrent cases. Low expression levels characterize the TP53 gene without significant differences in our samples. These findings demonstrate that cytokeratin expression distinguishes between pediatric/adult, nonrecurrent/recurrent cases, suggesting that distinct differentiation state and cell division potential characterize these cholesteatoma cases. KRT19 with a tumor suppressor potential might restrict the recurrence of cholesteatoma. The differences observed in gene expression profiles between cholesteatoma and control samples support the notion that cholesteatoma is a cystic lesion with tumor-like behavior because it is characterized by invasive, destructive growth and high tendency for recurrence.

Transient visual loss triggered by scuba diving in a patient with a petrous epidermoid and combined thrombotic risk factors.

A 25-year-old woman who developed transient neurological abnormalities after scuba diving is reported. The subsequent day she experienced transient left-side monocular blindness. Arterial ocular occlusion in apparently healthy young women is unusual, and a search for the cause of this devastating vascular event is mandatory. Occlusion of the left branch retinal artery, total occlusion of the left internal carotid artery, and a petrous apex epidermoid were found, together with a shortened prothrombin time (INR: 0.73), a slightly elevated serum cholesterol level (6.1 mmol/l) and combined thrombophilia (elevated FVIIIC plus type 2 sticky platelet syndrome). This case underlines the complex mechanism of thromboembolic diseases, and the importance of the acquired trigger (in the present case scuba diving) in addition to the long-term anatomical and biochemical risk factors.

A new mutation in the human pres gene and its effect on prestin function.

The electromotility of cochlear outer hair cells (OHCs) is a major factor in cochlear amplification that enhances the sensitivity of hearing in humans. Prestin is associated with presumed conformational changes in an integral membrane protein. Prestin knockout (-/-) mice display loss of OHC electromotility and a 40- to 60-dB reduction in cochlear sensitivity in vivo. In the present study we described the results of a direct sequencing mutation in the pres gene that was found in genetic screening performed in 47 patients characterized by non-syndromic, mild-to-moderate hearing impairment (30-70 dB) and in 50 control subjects from Hungary, after exclusion of GJB (GJB2, GJB6) mutations in the background. Only one patient and his normal-hearing father showed a heterozygous missense mutation (R150Q/WT) in the 6th coding exon of the pres gene. None of the 50 control subjects with normal hearing carried this mutation. Electrophysiological studies on the R150Q (homozygous and heterozygous) prestin mutant transiently transfected into reporting cells demonstrated nonlinear capacitance functions (NLC) as a signature of OHC electromotility. The capacitance function in human kidney cell line TSA 201 was similar for wild-type prestin and the mutant. However, for the mutant the voltage where the maximal charge displacement occurred (V1/2) significantly shifted in the hyperpolarizing direction ( approximately 15 mV). This is the first genetic and electrophysiological analysis of a human mutation in a coding exon of the pres gene by 47 patients with non-syndromic, sensorineural, mild-to-moderate hearing impairment; although the pathogenic role of the R150Q mutation is not unambiguous.