Benefit of a digital feedback suppression system for acoustical telephone communication

Because hearing instruments have traditionally performed poorly during acoustical telephone use, the benefit of using a Digital Feedback Suppression (DFS) system for acoustical telephone communication was evaluated. For this purpose a special speech test based on the method and material of the Oldenburg Sentence Test was developed, presenting the speech signal via a telephone receiver. The correct coupling of the receiver and the hearing aid was monitored by means of a probe microphone. The word score was determined for two different settings of the hearing aid: (1) DFS activated (2) DFS deactivated. The difference in word score between these two conditions is an indication of the benefit provided by the DFS system. For almost all subjects, speech recognition at the telephone could be improved using the DFS system. This is a significant contribution in increasing end-user overall satisfaction with hearing aids.     

Human heat shock protein 70 peptide complexes specifically activate antimelanoma T cells

Members of the heat shock protein 70 (HSP70) family display a broad cellular localization and thus bind a repertoire of chaperoned peptides potentially derived from proteins of different cellular compartments. In this report, we show that HSP70 purified from human melanoma can activate T cells recognizing melanoma differentiation antigens in an antigen- and HLA class I-dependent fashion. HLA class I-restricted anti-melanoma T cells were susceptible to MHC-restricted, HSP70-dependent stimulation, indicating that HSP70 complexed peptides were able to gain access to the class I HLA presentation pathway. In addition, MHC matching between the melanoma cells used as a source of HSP and the responding T cells were not required, indicating that HSP70 activation may occur across MHC barriers. Besides the MHC-restricted and peptide-dependent activation pathway, HSP70 with no endogenous complexed peptides or HSP70 purified from antigen-negative cells was also able to induce IFN-gamma release by antimelanoma T cells by a MHC-independent mechanism. In this case, however, higher doses of HSP70 were required. The capacity to activate class I-restricted, antitumor T cells as well as antigen-presenting cells, together with the finding that the HSP70 chaperoned peptide repertoire includes melanoma-shared epitopes, holds promise for a HSP70-based cancer vaccine.     

Positional vertigo and cochlear implantation.

OBJECTIVE: To identify patients developing positional vertigo after cochlear implantation. STUDY DESIGN: Prospective study on a cohort of patients undergoing cochlear implantation. SETTING: Academic tertiary referral center. PATIENTS: The study included 70 consecutive patients who underwent vestibular evaluation before and after cochlear implantation. INTERVENTION: Medical record review. MAIN OUTCOME MEASURE: Recorded vestibular symptoms after cochlear implantation. Patients with positional vertigo were considered case subjects, whereas those without vestibular symptoms were considered case controls. RESULTS: Benign paroxysmal positional vertigo (BPPV) occurred in 8 patients (on the cochlear implant [CI] side in 7 patients, and in the other ear in 1). One patient had BPPV of the lateral semicircular canal on the implanted side, and 7 patients had BPPV of the posterior semicircular canal (on the same CI side in 6 patients, and on the opposite side in 1), which were detected and presented during the last examination. In 5 patients, the onset of symptoms varied from 7 to 130 days after implant activation; in 2 patients, the onset occurred before activation. CONCLUSION: Three different mechanisms are proposed for the occurrence of BPPV in patients with CI. The first focuses on the fall of bone dust particles into the cochlea during cochleostomy. In the second, the vibration caused by drilling the cochlea would be sufficient to dislodge otoconia into the labyrinth. The third hypothesis suggests dislodging of an otolith because of the electric stimulation. In our patients, conservative approaches have been used with a minimal invasive cochleostomy and without perilymph suction. Thus, the vibratory trauma affecting the cochlea during cochleostomy seems to play a fundamental role in the development of paroxysmal vertigo in patients with implant.     

HER-2/neu is expressed in human renal cell carcinoma at heterogeneous levels independently of tumor grading and staging and can be recognized by HLA-A2.1-restricted cytotoxic T lymphocytes

The HER-2/neu oncoprotein, a 185 kDa membrane-associated tyrosine kinase with extensive homology to the epidermal growth factor receptor (EGF-R), is overexpressed in breast and ovarian carcinomas. Its overexpression is closely associated with poor prognosis in the course of disease. Here we demonstrate HER-2/neu overexpression in both established cell lines and biopsy material obtained from renal epithelial tumors. Immunohistochemical analysis of human kidney tumor lesions using 2 HER-2/neu-specific antibodies revealed HER-2/neu expression in more than 40% of primary epithelial renal tumors and more than 30% of primary renal cell carcinoma (RCC) specimens. A distinctive HER-2/neu expression pattern was found in different subtypes of kidney tumors with the highest frequency in chromophilic and chromophobic RCC, but neither associated with disease stage nor tumor grade. Eight of 10 RCC cell lines expressed significant levels of HER-2/neu mRNA and protein, but at a lower level compared with HER-2/neu overexpressing ovarian carcinoma cells. To evaluate the immune response against HER-2/neu expressing HLA-A2-positive (HLA-A2(+)) RCC cells, allogeneic HLA-A2-restricted cytotoxic T-lymphocyte (CTL) lines generated by pulsing dendritic cells with 3 different HER-2/neu-derived peptides, (HER-2(9.369), HER-2(9.435) and HER-2(9.689), were utilized in chromium-release assays. Specific lysis of HER-2/neu expressing HLA-A2(+) RCC cell lines was mediated by CTL lines specific for each of these 3 HER-2/neu-derived epitopes. The fine specificity of 2 CTL clones was defined to the epitopes HER-2(9.435) and HER-2(9.689). Their specificity was then confirmed by cold target inhibition assays. In addition, CTL-mediated lysis was enhanced by pulsing tumor cells with exogenous HER-2/neu-specific peptides. Our data suggest that (i) HER-2/neu is heterogeneously expressed in different subtypes of RCC, (ii) HER-2/neu is naturally processed by RCC and (iii) HER-2/neu epitopes presented by RCC can be recognized by HLA-A2-restricted, HER-2/neu-specific CTL.     

Hyaluronan and Hyaluronan-Binding Proteins Accumulate in Both Human Type 1 Diabetic Islets and Lymphoid Tissues and Associate With Inflammatory Cells in Insulitis

Hyaluronan (HA) is an extracellular matrix glycosaminoglycan that is present in pancreatic islets, but little is known about its involvement in the development of human type 1 diabetes (T1D). We have evaluated whether pancreatic islets and lymphoid tissues of T1D and nondiabetic organ donors differ in the amount and distribution of HA and HA-binding proteins (hyaladherins), such as inter-α-inhibitor (IαI), versican, and tumor necrosis factor–stimulated gene-6 (TSG-6). HA was dramatically increased both within the islet and outside the islet endocrine cells, juxtaposed to islet microvessels in T1D. In addition, HA was prominent surrounding immune cells in areas of insulitis. IαI and versican were present in HA-rich areas of islets, and both molecules accumulated in diabetic islets and regions exhibiting insulitis. TSG-6 was observed within the islet endocrine cells and in inflammatory infiltrates. These patterns were only observed in tissues from younger donors with disease duration of <10 years. Furthermore, HA and IαI amassed in follicular germinal centers and in T-cell areas in lymph nodes and spleens in T1D patients compared with control subjects. Our observations highlight potential roles for HA and hyaladherins in the pathogenesis of diabetes.     

Multiple cranial nerve involvement in Bannwarth’s syndrome

Bannwarth's syndrome is a tick-transmitted neurological disease caused by spirochetes of the Borrelia burgdorferi group. Neurological manifestations of the disease occur after skin erythema and include: neuritic pain, lymphocytic pleocytosis without headache and sometimes cranial neuritis. We present the case of a man who complained of a neurological syndrome without evidence of tick bite and concurrent manifestation of the infection, for whom serological analysis only revealed the infection after testing repetitive specimens. We discuss the need to start early therapy when clinical manifestations are suggestive of the disease in endemic areas.     

Microinjection of antisense c-mos oligonucleotides prevents meiosis II in the maturing mouse egg.

Injection of antisense oligonucleotides was used to investigate the function of c-mos in murine oocytes. Oocytes injected with antisense c-mos oligonucleotides completed the first meiotic division but failed to initiate meiosis II. Instead, loss of c-mos function led to chromosome decondensation, reformation of a nucleus after meiosis I, and cleavage to two cells. Therefore, c-mos is required for meiosis II during murine oocyte maturation.