In addition, 60 neonates who succumbed to other diseases were enrolled as controls. The lung tissues were collected within 30 min after death. In situ hybridization was conducted to detect SP-B mRNA expression in the lung. The frequency of SP-B mRNA deficiency was also calculated. Among the RDS groups, the SP-B mRNA levels were significantly higher compared to those in the control group , but were comparable among RDS patients with different gestational ages . Among the control groups, the SP-B mRNA levels increased with the increase in gestational age . In the ≤32-week group, the number of cells positive for SP-B mRNA in RDS patients was markedly reduced as compared to that of the controls . In the 32–36+6-week group, the number of cells positive for SP-B mRNA in RDS patients was significantly smaller compared to that of the controls . In the ≥37-week group, the number of cells positive for SP-B mRNA in RDS patients was markedly smaller compared to that in the controls . Among RDS neonates, SP-B mRNA deficiency was noted in 35 patients with a frequency of 58.3%. In the control group, SP-B mRNA deficiency was noted in 8 patients with a frequency of 13.3%, which was markedly lower compared to that in the RDS group . The results of the present study therefore suggest that SP-B mRNA deficiency is involved in the pathogenesis of RDS.The aim of this study was to investigate whether surfactant-associated protein B (SP-B) mRNA deficiency is involved in the pathogenesis of neonatal respiratory distress syndrome (RDS). A total of 60 unrelated neonates who died of RDS were recruited as the RDS group and subgrouped into a ≤32-, a 32–36 Phospholipids  account for 70–80% these pulmonary surfactants, while pulmonary surfactant-associated proteins including SP-A, SP-B, SP-C and SP-D account for 10% and the remaining 10% are the neutral fat (mainly cholesterol). Pulmonary surfactant is crucial in the reduction of the surface tension at the air-water interface where pulmonary surfactant is degraded and recycled. SP-B is an important pulmonary surfactant-associated protein capable of reducing or altering the surface tension by changing the surface area, preventing alveolar collapse . Studies+6- and ≥37-week group (n=20 per group) on the basis of gestational age. In addition, 60 neonates who succumbed to other diseases, including congenital heart diseases, bronchopulmonary dysplasia and persistent pulmonary hypertension, were enrolled as controls. The controls were also subdivided into gestational age-matched groups (P>0.05). The neonates developed RDS within 30 min to 6 h after birth and progressive dyspnea was the major clinical manifestation. Blood gas analysis showed hypercapnia and hypoxemia. These findings together with the chest X-ray results were employed to confirm the diagnosis of grade III or IV RDS. During the hospitalization, RDS patients were repeatedly treated with pulmonary phospholipids (200 mg/kg) from swine , with high frequency oscillatory mechanical ventilation being performed simultaneously. However, these patients died within 14 days. Informed consent was obtained from relatives and the whole study was approved by the Ethics Committee of General Hospital of Beijing Military Region.A total of 60 unrelated Han neonates in Beijing who succumbed to RDS were recruited from the NICU between July, 2006 and October, 2012 and then subdivided into ≤32-, 32–36in situ hybridization kit for SP-B , and other domestic reagents  were used in the present study. Digoxin-conjugated oligonucleotide probes targeting human SP-B were synthesized at the Department of Molecular Genetics as follows: i) 5′-ATGATGCCAGGTGTGTAGCC-3′; ii) 5′-AGAACCTCCCCATTGGAGC-3′; iii) 5′-GGCCTTGT GTCCAGGGAC-3′.A DAB kit, an Lung tissues were collected within 30 min after death. Samples were collected from the five lobes of RDS patients. In the control group, the lung tissues were randomly selected. The lung tissues were fixed in 4% paraformaldehyde, embedded in paraffin and consecutively cut into 5-μm sections.In situ hybridization was conducted to measure the mRNA expression of SP-B in the lung according to the manufacturer’s instructions, with modification. Sections were routinely deparaffinized and dehydrated and then treated with 3% methanol in H2O2 for 20 min. After washing in distilled water three times (5 min for each), sections were treated with pepsin in 3% citric acid at 37°C for 2 min. The sections were then washed three times in PBS for in situ hybridization (5 min for each) and in distilled water once. Sections were fixed in 1% paraformaldehyde/0.1 MPBS (pH 7.2–7.6) at room temperature for 10 min. The sections were treated with pre-hybridization solution at 42°C for 4 h and then with digoxin-conjugated probes at 42°C for 20 h subsequent to washing three times in distilled water. After washing twice with 2X SSC at 37°C (5 min for each), 0.5X SSC at 37°C for 15 min and 0.2X SSC at 37°C for 10 min, the sections were incubated at 37°C for 30 min. Subsequently, these sections were treated with biotin-conjugated mouse anti-digoxin antibody at 37°C for 90 min. The sections were washed four times in PBS for in situ hybridization (5 min for each) and treated with SABC at 37°C for 30 min. The sections were then incubated with biotin-conjugated peroxidase at 37°C for 30 min after washing three times in PBS for in situ hybridization (5 min for each). Subsequent to washing in PBS for in situ hybridization four times (5 min for each), the sections were visualized with DAB for 5 min, followed by washing in water and counterstaining with hematoxylin for 1 min. The sections were treated with 1% hydrochloric acid in alcohol followed by dehydration and transparentization, and mounted. The cell nucleus was stained blue and the sections were observed under a microscope. Representative images were captured. Of note, no probe or antibody was used, in the negative control group.Positive cells had yellow brown granules in the cytoplasm following staining. Positive cells were counted at a magnification of x400. Three sections were selected from each sample and 10 fields were randomly selected from each section. A total of 30 positive cells was counted in each sample, and the number of SP-B mRNA-positive cells was determined in each subgroup.The lower limit of normal of the number of SP-B mRNA positive cells was the mean - 2 standard deviations (−2SD). The sample with the number of cells lower than the lower limit of normal of the control group was defined as SP-B mRNA deficiency.2 test. P<0.05 was considered statistically significant.Statistical analysis was performed with SPSS version 13.0. Data were shown as the mean ± standard deviation (±SD). The paired t-test was employed to determine comparisons between the two groups, while the one way analysis of variance was performed to determine comparisons among different groups. SP-B mRNA deficiency was analyzed with χRDS developed within 30 min to 12 h after birth and dyspnea progressed rapidly. Results of the blood gas analysis showed hypercapnia and hypoxemia. These findings together with the chest X-ray results confirmed the diagnosis of RDS (grade III or IV). During the hospitalization, pulmonary phospholipids from the swine were repeatedly administered at 200 mg/kg (3–4 times). High frequency oscillatory mechanical ventilation was simultaneously performed. Although comprehensive therapy was also performed, these patients died naturally or refused further treatment due to economic concern. The neonates with grade IV RDS generally died within 7 days after birth.The SP-B mRNA was mainly found in the cytoplasm, stained yellow. The color and the extent of staining were different, varying in the neonates in different groups, with different gestational age and with different severities of RDS. Of 60 patients with RDS, 5 had a gestational age of 24 weeks, 4 had 26 weeks, 4 had 31 weeks, 7 had 34 weeks, 5 had 36 weeks, 4 had 38 weeks and 6 had 42 weeks. The SP-B mRNA expression in the lung in the RDS neonates was markedly lower than that in the gestational age-matched controls. Four neonates with a gestational age of 38 weeks were diagnosed with RDS of grade IV and the SP-B mRNA expression was lower than that in the remaining neonates. In the control group, 5 neonates with a gestational age of 24 weeks and 3 with 26 weeks had a lower SP-B mRNA expression as compared to the lower limit of normal .+6-week group, the SP-B mRNA-positive cells in RDS patients were significantly reduced when compared to those of the controls . In the ≥37-week group, the number of SP-B mRNA-positive cells in RDS patients was markedly lower than that in the controls  . Among the RDS groups, the number of SP-B mRNA-positive cells was comparable among RDS patients with a different gestational age . However, among the controls, the number of SP-B mRNA-positive cells were found to be elevated with the increase in gestational age . In the ≤32-week group, the number of SP-B mRNA-positive cells in RDS patients was markedly reduced as compared to that of the controls . In the 32–36P<0.001) .+6-week group and 10 neonates in the ≥37-week group with a lower SP-B mRNA level as compared to the lower limit of normal in the control group, with a frequency of SP-B mRNA deficiency of 58.3% (35/60). In the control group, there were 5 neonates in the ≤32-week group and 3 neonates in the 34–36+6-week group with a lower SP-B mRNA level as compared to the lower limit of normal, with a frequency of SP-B mRNA deficiency of 13.3% (8/60). Results of the statistical analysis revealed a significant difference in the frequency of SP-B mRNA deficiency in the RDS and control groups .In the RDS group, there were 13 neonates in the ≤32-week group, 12 neonates in the 34–36et al (The deficiency of pulmonary surfactant of any cause is known to potentially cause neonate RDS. Although the SP-B protein accounts for 1–2% of PS compound, SP-B is a crucial SP in the maintenance of normal surfactant function . SP-B haet al  identifiet al . The SP-et al –15.In the present study, the SP-B mRNA expression in the lung was detected in RDS and non-RDS neonates. Results showed that SP-B mRNA was mainly found in the cytoplasm and the SP-B mRNA level varied in different groups, including neonates with different gestational ages and those with RDS of different severities. Of 60 neonates with RDS, the SP-B mRNA expression in the lung was not enhanced with the increase in gestational age. In 5 neonates with a gestational age of 24 weeks, 4 with 26 weeks, 4 with 31 weeks, 7 with 34 weeks, 5 with 36 weeks, 4 with 38 weeks and 6 with 42 weeks, the SP-B mRNA expression was markedly lower than that in the gestational age-matched controls. In addition, four neonates with a gestational age of 38 weeks were diagnosed with RDS of grade IV, with the SP-B mRNA expression being lower than that in the remaining RDS group. Of 60 controls, 5 with a gestational age of 24 weeks and 3 with 26 weeks exhibited a lower SP-B mRNA expression than the lower limit of normal. Furthermore, the frequency of SP-B mRNA deficiency was determined to be 58.3% in the RDS group and 13.3% in the control group. The statistical analysis showed the frequency of SP-B mRNA deficiency in RDS neonates to be markedly higher than that in the controls. Thus, the SP-B protein deficiency may be attributed to the reduced transcription of SP-B mRNA, which is indirectly involved in the pathogenesis of RDS. This finding may be explained as follows: the transcription of SP-B mRNA is reduced, and then the SP-B protein expression is decreased. Thus, the formation of lamellar bodies or tubular myelin is disrupted, the mature SP-B is reduced, and the secondary mature SP-C is also decreased. Consequently, the spread and adherence of the pulmonary surfactant on the air-water interface is reduced, and the activity of pulmonary surfactant is compromised. Subsequently, the ability of the pulmonary surfactant to reduce the alveolar surface tension was compromised resulting in alveolar collapse. The fluid exudates from the capillary into the alveoli. In addition, the reduction of SP-B reduces resistance, and the antimicrobial activity of SP-B in the lung is attenuated or disappears resulting in the presence of neonate RDS. In the present study, we confirmed the hypothesis of our previous study . The altNumerous studies have been conducted to investigate the correlation between SP-B deficiency and some diseases. Results have shown that SP-B deficiency is correlated with certain pulmonary diseases including neonatal RDS and chronic obstructive pulmonary ,18. Rece


Aleocharinae fauna of the Maritime Provinces of Canada, reporting that 203 species were known in the region. They also added 16 new provincial records from the region. Inadvertently, they neglected to provide new provincial records of three species that were indicated as occurring in Nova Scotia in Table 1 (pp. 23-33) of their results. This omission is rectified below wherein Gyrophaena modesta Casey, Gyrophaena subnitens Casey, and Placusa vaga Casey are all newly recorded as occurring in Nova Scotia. Tachyporus nitidulus as occurring in Prince Edward Island. There are no records of this adventive Palaearctic species from the province, although it is more widely distributed in Nova Scotia than hitherto reported. Additional records of Tachyporus nitidulus are provided from Nova Scotia.Gyrophaena modesta Casey, 1906NOVA SCOTIA: Kings County: Wolfville, 19 September 1998, J. Ogden, sweeping grasses .Gyrophaena modesta is newly recorded from Nova Scotia . It was reported from Alberta and New Brunswick by PageBreakous and mixed forests on fresh gilled fungi, and occasionally on decaying gilled fungi and Pleurotus sp. fungi on a log .Gyrophaena subnitensis newly recorded from Nova Scotia . It was reported from Manitoba and Ontario by Quercus rubra) forest  forest . In NovaPlacusa vaga Casey, 1911NOVA SCOTIA: Kings County: North Alton, 2 June 2005, D.H. Webster, under bark of Populus tremuloides windfall .Placusa vaga is newly recorded from Nova Scotia . The specimen collected in North Alton was found in association with Carpophilus sayi Parsons (Nitidulidae) (abundant) and Corticeus tenuis (LeConte) (Tenebrionidae) (infrequent). Placusa vaga was reported from British Columbia and Québec by Tachyporus nitidulus NOVA SCOTIA: Halifax County: Halifax, 19 June 2009, S. MacIvor, open area, pitfall trap ; Hants County: Upper Rawdon, 24 June 2008, 25 June 2008, 26 June 2009, 27 June 2009, 28 June 2009, 21 July 2009, 22 July 2009, 24 July 2009, 13 August 2009, 14 August 2009, 26 August 2009, 8 September 2009, J. Renkema, highbush blueberry field, pitfall trap ; Queens County: Kejimkujik National Park, 24 August 1994, B. Wright, hemlock forest, leaf litter .Tachyporus nitidulus was reported from New Brunswick by Tachyporus nitidulus as an adventive Palaearctic species in North America.Tachyporus nitidulus is removed from the faunal list of Prince Edward Island. It has, however, been found more widely in Nova Scotia than prevPageBreakiously reported, and the records above provide additional collecting localities in the province .Subsequently, however, It is often found in moist habitats such as river debris and swampy areas, along streams, lakes, or in wet seepages. It is common in all kinds of rotting materials; found in leaf litter, decaying material in hollow logs and stumps, and in mammal nests; and has been swept from flowers and bushes .


No studies, however, are available on the development of the Weberian ossicles and its effect on the development of hearing in catfishes.The Weberian apparatus of otophysine fishes facilitates sound transmission from the swimbladder to the inner ear to increase hearing sensitivity. It has been of great interest to biologists since the 19Lophiobagrus cyclurus. Specimens from 11.3 mm to 85.5 mm in standard length were studied. Morphology was assessed using sectioning, histology, and X-ray computed tomography, along with 3D reconstruction. Hearing thresholds were measured utilizing the auditory evoked potentials recording technique. Weberian ossicles and interossicular ligaments were fully developed in all stages investigated except in the smallest size group. In the smallest catfish, the intercalarium and the interossicular ligaments were still missing and the tripus was not yet fully developed. Smallest juveniles revealed lowest auditory sensitivity and were unable to detect frequencies higher than 2 or 3 kHz; sensitivity increased in larger specimens by up to 40 dB, and frequency detection up to 6 kHz. In the size groups capable of perceiving frequencies up to 6 kHz, larger individuals had better hearing abilities at low frequencies (0.05–2 kHz), whereas smaller individuals showed better hearing at the highest frequencies (4–6 kHz).We investigated the development of the Weberian apparatus and auditory sensitivity in the catfish Our data indicate that the ability of otophysine fish to detect sounds at low levels and high frequencies largely depends on the development of the Weberian apparatus. A significant increase in auditory sensitivity was observed as soon as all Weberian ossicles and interossicular ligaments are present and the chain for transmitting sounds from the swimbladder to the inner ear is complete. This contrasts with findings in another otophysine, the zebrafish, where no threshold changes have been observed. Otophysine fish comprise four orders (Cypriniformes (carps and relatives), Characiformes (tetras), Gymnotiformes (South American knifefishes) and Siluriformes (catfishes)) containing approximately 8000 species Galeichthys felis (nowadays Ariopsis felis) Clarias gariepinusSilurus asotusPseudobagrus ichikawai (nowadays Coreobagrus ichikawai) Corydoras paleatus and the ictalurids Noturus exilis, N. miurus and Ictalurus punctatusThe ontogenetic development of Weberian ossicles has been studied in several cypriniforms (It remains unclear when the Weberian apparatus is completely developed (including interossicular ligaments) and starts to transmit sounds from the swimbladder to the ear.Stegastes partitus, Iwashita et al. Pagrus major, Wysocki and Ladich Trichopsis vittata, Higgs et al. Alosa sapidissima, Sisneros and Bass Porichthys notatus, and Vasconcelos and Ladich Halobatrachus didactylus). Only Egner and Mann Abudefduf saxatilis; Belanger et al. Neogobius melanostomus.Numerous morphological studies have been conducted on the ontogenetic development of the auditory periphery in fish, in particular on Weberian ossicles. In contrast, little information is available on the development of hearing in fishes, especially in otophysines. Studies in non-otophysine fishes regularly observed an increase in hearing sensitivity with size  in a representative of the order Siluriformes. We chose the African claroteid catfish 4, 343 = 174.98, P<0.001) and a significant interaction between group and frequency . Thus changes in auditory sensitivity showed different trends at different frequencies. According to Scheffé's post hoc test group XS differed from all other size groups. Thresholds of specimens of group XS rose rapidly above 300 Hz, and only two out of six specimens responded to tone bursts at 3 kHz and none at 4, 5 and 6 kHz. Group XS showed its highest hearing sensitivity at 300 Hz  In the zebrafish Poecilobrycon (now Nannostomus) harrisoni at 7 mm SL.In the goldfish, the Weberian ossicles appear first at 10 mm Brycon erythropterus  and the piranha Serrasalmus sp., the differentiation of ossicles progresses from posterior to anterior In the zebrafish and the two characiform species Silurus asotus – Ichiyangi et al. Pseudobagrus ichikawai – Ichiyanagi et al. I. punctatus – Grande and Shardo L. cyclurus the intercalarium is the last of the four ossicles to appear. This is in contrast to the observations mentioned above and to the observations of authors studying Weberian ossicles in catfishes having an intercalarium  (this species lacks a claustrum), but a “continuous stretch of tissue” between the bladder and inner ear is not yet developed at this stage Clarias gariepinnus the Weberian ossicles are fully developed at 15 mm TL Corydoras paleatus, which possesses only a single ossicle, this ossicle was found at 5–7.6 mm standard length (SL), but not fully ossified at this stage Ictalurus punctatus and larger than 8.3 mm in the genus NoturusLophiobagrus cyclurus. According to our morphological and physiological data a fully developed ossicular chain including interossicular ligaments is present in group S (min. 24.0 mm SL).Other studies fail to mention the sequence of ossicle appearance but do describe the appearance of all elements at a particular fish size. In the hardhead sea catfish Lophiobagrus cyclurus is not a single ossicle (like the left tripus) at the earliest analysed stage (group XS) but is bipartite, a situation similar to that described in the goldfish by Watson Scardinius erythrophthalmus by Matveiev The right tripus of L. cyclurus also shows only a slight indication of a processus. This was described by Bornbusch Most catfish in which an intercalarium is present show reduced or missing processes of the intercalarium L. cyclurus. Grande and Shardo Ictalurus punctatus. In our study species L. cyclurus, specimens of the smallest size group XS (size 11.3–15.3 mm SL) did not yet have fully ossified ossicles. Our µCt scans showed only the small ossified parts of the ossicles and no cartilaginous areas, in contrast to the 3D reconstructions of the sections which showed ossified and cartilaginous parts. In the bagrid catfish Pseudobagrus (Coreobagrus) ichikaway the scaphium was ossified at 14.8 mm SL and all ossicles of the Weberian system at 25 mm SL L. cyclurus, which show ossified ossicles and well-developed hearing beginning with stage S. We suppose that P. ichikaway possesses well-developed hearing capabilities, similar to L. cyclurus, at this stage.The ossification of Weberian ossicles has been discussed in several papers: Watson L. cyclurus changed significantly at all frequencies. At this point we cannot explain the different results in zebrafish and L. cyclurus.The present study reveals a relationship between hearing acuity and the development of the Weberian apparatus. Specimens of the smallest stage lacked a fully developed chain of Weberian ossicles and interossicular ligaments, suggesting that transmission of swimbladder oscillations to the inner ear is probably reduced or not yet possible. This may have affected absolute hearing thresholds and reduced the ability to detect higher frequencies (3–6 kHz). Surprisingly, the lack of a complete chain of Weberian ossicles had quite different effects in the zebrafish Synodontis schoutedeniL. cyclurus and 5–6 kHz in S. schoutedeni), and larger specimens show better low-frequency hearing (50 Hz–1 kHz). These changes are probably not caused by the development of the ossicular chain , but by further, still unknown reasons.Our data support previous findings in the squeaker catfish Grande and Young In an earlier study on the goldfish, Popper Alosa sapidissima.Generally, changes in hearing abilities during ontogeny are known in several fish species S. schoutedeniS. schoutedeni and non-otophysine fish.The present study supports recent findings in the squeaker catfish Ameiurus nebulosus resulted in a frequency-independent decrease in hearing sensitivity. In contrast, Ladich and Wysocki L. cyclurus and supports our interpretation that hearing improvement depends on the presence of an uninterrupted Weberian chain of ossicles.The importance of the uninterrupted Weberian chain has been studied in adult otophysines by Poggendorf Lophiobagrus cyclurus shows that the improved hearing abilities in this siluriform fish and probably in all otophysines depend on the development of the Weberian apparatus. We show that the freshly hatched catfish do not yet possess a fully developed Weberian apparatus, which probably reduces hearing acuity and the range of detectable frequencies. We furthermore illustrate that pronounced differences exist between the zebrafish and L. cyclurus.In summary, our study on the catfish Lophiobagrus cyclurus  were aquarium bred and obtained from Oliver Drescher . Fish were kept in planted aquaria with a sand bottom equipped with roots and clay or bamboo tubes as shelters. In order to provide a quiet environment, we used only external filters and no internal filters or air stones. Temperature was kept at 25±1°C and a 12 h : 12 h L : D cycle was maintained. Fish were fed frozen chironomid larvae and artificial food ; the small specimens of groups XS were also fed Cyclop-Eeze® . Since fry and juveniles grow very unequally despite identical conditions of husbandry All For hearing measurements, fish were grouped into five size groups, XS , S , M , L  and XL . Complete audiograms could not be obtained from each fish, in particular in the smallest size group. A minimum of six hearing thresholds was determined for each group and each frequency.For morphological examinations, fish were sedated using an overdose of tricaine methanesulphonate  and then immediately preserved in alcohol (70%), formalin (4%) or Bouin's solution Dissections were carried out in alcohol-preserved specimens  with the aid of dissection microscopes . Bones and ossicles were stained in a solution of KOH (1%) and alicarin red. The photo of Weberian ossicles was taken using a Leica MZ16 F microscope  and a ProgRes C5 camera ; the photograph was edited with Adobe Photoshop CS5 .Microcomputed tomography  was used to assess bone architecture using 3.5, 6, 10 and 15 µm isotropic voxel size (depending on the size of the scanned specimen). One specimen each of group XS, S, L and XL was scanned in 70% ethanol along the coronal axis. Images were acquired at 70 kV and 57 µA with a 0.18° rotation between frames. CT images were reconstructed in 2048×2048 pixel matrices using a standard convolution-backprojection procedure. The resulting greyscale image stack was cropped to the region of interest before importing it into 3D-reconstruction software Amira 4.1 . Bony structures were visualized as volume rendering using the Voltex tool and the VolrenGlow colormap of Amira. To accentuate the Weberian ossicles within the volume rendering, they were surface-reconstructed by labelling them with the magic wand tool of the Amira segmentation editor, with minor corrections conducted with the brush tool. A surface for each ossicle was created using Amira's SurfaceGen. Surfaces were optimised by iterated simplification and smoothing steps. Snapshots of the surface reconstruction were taken with Amira.For paraffin-based histology, three animals of stage XS were fixed in Bouin's solution One specimen of group XS was decalcified for resin-embedding by storage in Bouin's solution for several weeks. After decalcification, the specimen was transferred to 70% alcohol, dehydrated in graded alcohol, and embedded in Agar low viscosity resin  using acetone as intermediate. Ribbons of serial sections (2 µm section thickness) were obtained with a Histo Jumbo diamond knife on a Reichert Ultracut S microtome  −1) was placed close to the head on the right side of the animals (∼1 cm away) in order to determine absolute stimulus SPLs. A custom-built preamplifier was used to boost the hydrophone signal. Both presentation of sound stimuli and AEP waveform recording were achieved using a modular rack-mount system  controlled by a PC containing a TDT digital signal processing board and running TDT BioSig RP software.Hearing thresholds were obtained using the AEP recording technique developed by Kenyon et al. Hearing thresholds were determined at 0.05, 0.07, 0.1, 0.3, 0.5, 0.8, 1, 2, 3, 4, 5 and 6 kHz. The duration of sound stimuli increased from two cycles at 50 Hz, 70 Hz and 100 Hz up to eight cycles at 4 kHz and above. Rise and fall times increased from one cycle at 50 to 300 Hz, up to three cycles at frequencies from 2 to 6 kHz. All bursts were gated using a Blackman window. For each test condition, one thousand stimuli were presented at opposite polarities, i.e. 90° and 270°, and were averaged together by the BioSig RP Software, yielding a 2000-stimulus trace to eliminate any stimulus artifact. The SPL was reduced in 4-dB steps. Close to hearing threshold, this procedure was performed twice and the AEP traces were overlaid to visually check if they were repeatable. The lowest SPL at which a repeatable AEP trace could be obtained, as determined by overlaying replicate traces, was defined as the threshold see also . Sound sAll data were tested for normal distribution using Shapiro-Wilk's test. When data were normally distributed, parametric statistical tests were applied. Mean hearing thresholds were determined for each size group and at each frequency, and audiograms were drawn using SigmaPlot 10.0 . Means of sound characteristics were calculated for each fish and used for further analyses. Audiograms of different size groups were compared by a two-factor analysis of variance (ANOVA) using a general linear model where one factor was size group and the other was frequency. A Scheffé's post hoc test revealed which groups differed from each other. Relationships between fish size (SL) and hearing thresholds were determined by Pearson's correlation coefficients and linear regressions. The statistical tests were performed with the software SPSS 17.0 . When datapoints showed two different distribution patterns, segmented linear regressions and breakpoints were calculated using the software SegReg .The study protocol was approved by the Austrian Federal Ministry of Science and Research, permit number GZ 66.006/0023-II/10b/2008.


Varicose veins affect approximately one-third of the adult population and result in significant psychological, physical, and financial burden. Nevertheless, the molecular pathogenesis of varicose vein formation remains unidentified. Venous hypertension exerted on veins of the lower extremity is considered the principal factor in varicose vein formation. The role of mechanotransduction of the high venous pressure in the pathogenesis of varicose vein formation has not been adequately investigated despite a good progress in understanding the mechanomolecular mechanisms involved in transduction of high blood pressure in the arterial wall. Understanding the nature of the mechanical forces, the mechanosensors and mechanotransducers in the vein wall, and the downstream signaling pathways will provide new molecular targets for the prevention and treatment of varicose veins. This paper summarized the current understanding of mechano-molecular pathways involved in transduction of hemodynamic forces induced by blood pressure and tries to relate this information to setting of venous hypertension in varicose veins. Varicose veins are a common venous disease of the lower extremity which affects more than 30 per cent of the adult population in Western countries –3. VaricVaricose veins are characterized by symptoms or signs produced by venous hypertension as a result of structural or functional abnormalities of veins. Symptoms may include aching, heaviness, cramps, itching, sensations of burning, swelling, dilatation or prominence of superficial veins, and skin changes. Signs may include telangiectasia, reticular or varicose veins, edema, and skin changes such as pigmentation, lipodermatosclerosis, eczema, and ulceration. A descriptive classification, known as CEAP, was developed to standardize reporting of chronic venous disorders . The CEABecause the history and physical examination are not always able to determine the nature and extent of venous insufficiency, a number of diagnostic investigations have been developed . CurrentTreatment of superficial venous incompetence can be accomplished by different techniques including gradient elastic compression stockings, ligation and stripping, sclerotherapy, ultrasound-guided sclerotherapy, endovenous laser or radiofrequency thermal ablation, cutaneous lasers, and intense pulse light devices , 16. Varicose veins have a recurrence rate of 26% to 60% following surgery –19, maki Because of the location of varicose veins in the lower extremity, and the increase in lower extremity venous pressure in the standing position, a relationship between the lower extremity high venous pressure and the formation of varicose veins has long been proposed. Nevertheless, the molecular pathways responsible for the transduction of the high venous pressure into vein wall dilation are not clear. Specifically, how the venous pressure could be trasduced to mechanical sensors in the vein wall, which in turn affect downstream signaling pathways and eventually affect molecular targets that modulate vein function, remains unclear. The purpose of this paper is to discuss some of the reports in the Pubmed database in order to highlight the role of mechanical transduction of venous hypertension into biochemical pathways in the vein wall and their eventual effect on downstream target molecules. We will first discuss the physiological and pathological changes in lower extremity venous pressure, the mechanosensors in the vein wall, then the signaling mechanisms and vascular mediators in the endothelium, venous smooth muscle, and extracellular matrix of the venous wall. The discussion of these signaling mechanisms and molecular targets would help in the design of new molecular targets in the management and prevention of recurrent varicose veins.In the upright position and in the absence of muscle contraction, venous hydrostatic pressure measured on the dorsum of the foot ranges from 90 to 120 mmHg, depending on the individual's height . Return Blood vessels are constantly subjected to various types of hemodynamic forces including shear stress and circumferential stretch induced by the blood flow and pressure, respectively. Shear stress is the frictional force of the blood on the endothelial layer while the circumferential stretch is the circumferential distension of blood pressure . These fElevated venous pressure in the lower extremity veins during prolonged standing generates circumferential stretch of the vein wall and imposes mechanical stimulation on both ECs and SMCs. Among the most studied mechanosensing systems in response to circumferential stretch are the integrins, the flow-sensitive ion channels, and G protein coupled receptors (GPCRs)  25–28].–28.25–28α subunit and a β subunit. There are at least 18 α subunits and 8 β subunits, and these subunits associate to generate at least 24 different integrins . Al. Al2) inAlthough the link between mechanosensors translation of circumferential stretch to biological molecules remains to be fully elucidated, considerable knowledge of downstream signaling pathways has been gained. The multitude of signaling pathways involved in varicose vein formation can, however, be grouped under three mechanisms, vein wall hypoxia, inflammation, and remodeling . Hypoxia of the lower extremity vein wall has been proposed as a causative factor in varicose vein formation –76. OxygP < 0.05) . . + channβ1 present in the ECM and that this process is inhibited by antagonizing integrins and independent from protease activity, thus establishing a link between the mechanical force of vein wall stretch and activation of the biological molecule, TGF-β1 [β1 is a multifunctional cytokine that regulates diverse cellular functions such as proliferation, migration, differentiation, and extracellular matrix production. Several studies have demonstrated that mechanical stretch can activate latent TGF- TGF-β1 –120. TGFβ1 and its downstream signaling proteins in the wall of varicose veins compared to normal veins (β1 and loss of vascular SMCs, in a series of normal and varicose vein specimens. They found that TGF-β1 was differentially overexpressed in varicose veins with greater expression in the tortuous segments compared with the nontortuous segments of the varicose vein. Only a very small amount of expression of TGF-β1 was detected in normal vein samples. Histological examination revealed disruption of elastic lamellae and a significantly high degree of loss of vascular SMCs [β1 acts as a bifunctional regulator of SMC proliferation, apoptosis, migration, and phenotype [β1 expression when compared with cells grown in static conditions [ Clinical investigations have demonstrated increased expression of TGF-al veins  [82, 121lar SMCs . It has henotype , 123. O'nditions . β1 and for activation of its latent inactive form that already exist in the ECM. Moreover, it has also been demonstrated that TGF-β1 mediates tissue remodeling through regulation of collagen synthesis, MMP synthesis, and differentiation of fibroblasts into contractile myofibroblasts. These studies showed that mechanical stress is responsible for overexpression of TGF-2+ entry via voltage-gated Ca2+ channels. This would explain the greater incidence of varicose veins in females. A third topic would be investigating the relevance of flow-sensitive ion channels, such as flow-sensitive K+ channels, in modulating venous ECs susceptibility to inflammation induced by low or oscillatory shear stress in human varicose veins. Future studies should also confirm and expand on previous findings showing that a single longitudinal stretch of saphenous vein grafts produces significant increase in the expression and activation of αv integrin, MMP-2, and MMP-9, key molecules in vascular remodeling. These and other studies would expand our understanding on how vein wall ECs, SMCs, FBs, and ECM sense and transduce stimuli of hemodynamic forces, particularly venous hypertension, into biochemical signals. This knowledge would be critical to developing new therapies for the prevention and treatment of varicose veins. The pathobiology of varicose vein formation is one of the fields that need increasing research attention given the significant social, medical, and economic importance. The recent characterization of several mechanosensors in the ECs and SMCs will stimulate future research of the mechanotransduction signaling pathways involved in the development of varicose veins. Possible areas of future research and intervention could be suggested based on current understanding of mechanotransduction. One such research areas would investigate stretch-induced myogenic response in human saphenous vein. Given that studies have shown that saphenous vein of humans and animals exhibits an active myogenic response and that stretch-induced AT1R and TRPC channels signaling mechanism are responsible for the myogenic response in arteries, it remains, however, to delineate the underlying signaling pathways and the identity of mechanosensors of myogenic response in human superficial veins of the lower extremities. Failure of this myogenic response may have a critical role in the development of varicose veins. A second area of research would be confirming in nonvaricose and varicose saphenous veins the previous animal studies that shows reduced contraction in female rat IVC compared with male due to reduced Ca


Slow cortical potentials (SCPs) are currently of great interest in the hearing aid fitting process for infants; however, there is conflicting evidence in the literature concerning the use of SCPs for this purpose. The current study investigated SCP amplitudes and latencies in young normal-hearing listeners in response to a 60 ms duration tonal stimulus (1000 Hz) presented at three intensities  in aided and unaided conditions using three hearing aids  with two gain settings (20 and 40 dB). Results showed that SCP amplitudes were smaller for the digital hearing aids compared with the analog hearing aid, and none of the hearing aids resulted in a reliable increase in response amplitude relative to the unaided across conditions. SCP latencies in analog conditions were not significantly different from latencies in the unaided conditions; however, both digital hearing aids resulted in significantly delayed SCP latencies. The results of the current study  indicate that the SCP may not accurately reflect the amplified stimulus expected from the prescribed hearing aids. Thus, “aided-SCP” results must be interpreted with caution, and more research is required concerning possible clinical use of this technique. With the advent of Universal Newborn Hearing Screening programs, it has become increasingly common for infants to be fitted with hearing aids by six months of age, which requires that reliable methods are in place for fitting hearing aids in this young population –4. TherePrevious ABR research revealed that the click and brief-tone stimuli required for ABR testing are too short to activate the compression processing and steady-state response of the hearing aid; thus, the ABR has been deemed not to be suitable for assessment of responses to hearing-aid-processed stimuli –11. In lSlow cortical potentials have an advantage over brainstem AEPs because they originate in the auditory cortex –21 and csmaller aided N1-P2 amplitudes compared to unaided [Despite the current upsurge of interest in the use of cortical SCPs with hearing aids in infants and children, there are several recent studies which indicate that concerns exist regarding the use of SCPs for this purpose. For example, some recent studies on SCPs in subjects with normal hearing using speech and tonal stimuli have found that the addition of hearing aid gain does not lead to the expected increase in N1-P2 amplitude that occurs in response to higher stimulus levels, such that there were either no significant differences between unaided and aided N1-P2 amplitudes , 30 or s unaided . Billing unaided , 36 have unaided , 30 was The stimuli used by Billings and colleagues , 30, 36 Due to conflicting evidence regarding the use of SCPs for hearing aid measurements, the primary aims of the current study were: (i) to determine the effects of hearing aid gain on the SCP and, specifically, whether different hearing aid gains are accurately reflected by the SCP, and (ii) to assess whether results are similar for different hearing aids set with the same gain characteristics. Of particular interest was whether there would be a difference between unaided and aided response amplitudes and latencies when hearing aids were set for 20 or 40 dB of gain and whether unaided and aided response amplitudes and latencies would be comparable for equivalent nominal output levels.Thirteen normal-hearing subjects participated in this study . Subjects were briefed on the study procedures and provided informed written consent prior to participating. All subjects were screened for normal hearing by behavioural audiometry and for normal middle/outer ear function by immittance audiometry. Normal hearing was defined by pure-tone behavioural thresholds equal to or better than 15 dB HL from 500 to 4000 Hz and equal or better than 20 dB HL at 250 and 8000 Hz . Normal μV in any of the channels, and ±75 μV in the EOG channel), and averaging. The stimulus was presented in each test condition until at least 200 accepted trials were obtained. Epochs were averaged separately for each condition, and average data were divided into odd and even trials to serve as replications . Averages were baseline-corrected using the prestimulus interval.One electroencephalogram (EEG) channel was recorded from electrodes placed at Cz and M1. A second channel to monitor vertical eye movements and eye blinks (EOG) was recorded from electrodes over the left supraorbital ridge of the frontal bone and over the zygomatic bone under the left eye. A fifth electrode on the nape of the neck served as ground. Electrode impedances were maintained below 5000 Ohms. Recordings were made using Neuroscan Synamps 2 and Scan 4.3 software. The EEG and EOG channels were amplified, filtered (1–30 Hz), and digitized (5000 Hz), using a 700 ms analysis time (including a 100 ms prestimulus baseline). Single-trial epochs were saved for offline processing, including baseline correction across the total sweep duration, artifact rejection  Oticon E27 , (ii) Phonak Savia 211 dSZ , and (iii) Siemens Acuris S . Two digital hearing aids were selected because digital signal processing is currently the most commonly used technology; therefore, SCP results using digital hearing aids are the most clinically relevant. An analog hearing aid was selected to account for possible discrepancies between results for digital hearing aids and those in the published literature which primarily used analog hearing aids , 31, 33.The digital hearing aids were programmed using NOAH 3 software and the NOAHlink programming assistant. Two gain settings (20 and 40 dB) were required; therefore, for each subject, two programs were created and the gain settings were verified by real-ear insertion gain (REIG) measures. The 20 dB gain setting was chosen to approximate the hearing aid setting used by Billings et al. , and theREIG was determined for each individual participant using the Fonix 7000 real-ear system. REIG was chosen because it equals the difference between unaided and aided responses in the ear canal, which most closely approximates the comparisons made in these studies . A small probe tube (3 mm in diameter) was placed in the ear canal of the participant within 5 mm of the eardrum (verified by otoscopy). The tube was then marked at the tragal notch to ensure identical probe-tube placement across hearing aids. The gain control setting at 1000 Hz was adjusted until the appropriate REIG level was achieved for each program; other frequencies were set to provide the least amount of gain possible.A swept pure tone with constant input level across the frequency range was used to measure REIG. A pure-tone stimulus was used as this is the same type of stimulus  used to elicit the SCPs. A 50-dB SPL input level was used to program both 20- and 40 dB REIG settings, and a 70-dB SPL input level was used to verify the 20 dB REIG settings; these were the same input levels and gains used in the SCP testing. For all participants, all hearing aids matched target gain within 1 dB for all input levels used in SCP testing, except 30 dB SPL, which could not be verified as it was below the levels available in the hearing aid test system. These measures provided further verification that all three hearing aids were providing linear processing and that all measures were below the maximum output of the hearing aid.Electroacoustic measures of processing delay were conducted on the Fonix 7000 test system. The delays were 0.4 ms for the Analog aid, 6.8 ms for DigitalA, and 2.3 ms for DigitalB.The stimulus used was a 1000-Hz tonal stimulus of a 60 ms total duration . A 20 ms rise/fall time was chosen because it is suitable for generating a large N1 response, and the 60 ms total duration was chosen because it has been shown that stimuli of longer duration do not result in increased N1 amplitudes –41. StimParticipation in this study involved two sessions on separate days, each 2 -3 hours in length . Subjects were screened for normal hearing and for normal outer- and middle-ear function. Immittance audiometry was also conducted in the second test session to ensure no changes across test sessions.Following hearing aid programming, all testing was conducted in a double-walled sound-attenuating booth. Average octave band noise levels in the sound-attenuated booth at 500, 1000, 2000, and 4000 Hz were 12, 10, 10, and 12 dB SPL, respectively. There were 18 test conditions, and the presentation order for each subject was randomly assigned prior to the test dates. During testing, participants were asked to sit as still as possible while watching a movie of their choice in closed captioning and no sound. Subjects sat in a reclining chair set in the upright position so that each participant was seated with their head above the chair back. This position was chosen because (i) calibration measures showed that it was the “flattest” spot in the soundfield, making it appropriate for the substitution method of calibration employed in these measures, and (ii) it was easy to monitor via closed-circuit television whether the participant's head position had moved substantially out of the calibrated spot in the soundfield.μV was substituted as a reasonable estimate of amplitude .For amplitude measures, four repeated-measures analyses of variance (ANOVA) were conducted: (i) to measure the effect of the 20 dB gain setting, a two-way repeated-measures ANOVA was conducted comparing four levels of hearing aid type  and three input levels , (ii) to measure the effect of the 40 dB gain setting, a two-way repeated-measures ANOVA was conducted comparing four levels of hearing aid type  and two input levels (30 and 50 dB SPL), (iii) to compare 20 and 40 dB gain settings, a three-way repeated-measures ANOVA was conducted comparing two levels of gain (20 and 40 dB), three levels of hearing aid type , and two input levels (30 and 50 dB SPL), and (iv) to compare results for a 70 dB SPL “nominal output” , a one-way repeated-measures ANOVA with seven “conditions” was conducted .For latency measures, the following three repeated-measures ANOVAs were conducted: (i) to measure the effect of the 20 dB gain setting, a two-way repeated-measures ANOVA was conducted comparing four levels of hearing aid type  and two input levels (50 and 70 dB SPL), (ii) to measure the effect of the 40 dB gain setting, a one-way repeated-measures ANOVA was conducted (because the 30 dB SPL input level was excluded) comparing four levels of hearing aid type  at one input level (50 dB SPL), and (iii) to make comparisons between the 20 and 40 dB gain settings, a one-way repeated-measures ANOVA was conducted comparing three levels of hearing aid type  at 50 dB SPL. Analysis of “nominal output” was not conducted for latency measures due to the absence of latency results for the 30 dB SPL input level and thus the exclusion of the 40 dB gain condition.P < 0.05. Huyn-Feldt epsilon (ε) correction factors for repeated measures were applied to the degrees of freedom and are reported where appropriate. Neuman-Keuls post hoc analyses were performed for significant main effects or interactions. Post hoc analyses were considered statistically significant if P < 0.05.For all analyses, the main effects and interactions were considered significant if Grand mean waveforms for unaided compared with 20 and 40 dB of hearing aid gain for three hearing aids  across three input levels  are shown in F = 2.48, ε = 0.78, P = 0.046); Neuman-Keuls post hoc analysis showed that N1-P2 amplitudes in the DigitalB condition were significantly smaller at 50 and 70 dB SPL input levels compared with the other aided conditions as well as the unaided. There were no significant differences between N1-P2 amplitudes at 30 dB SPL with or without hearing aids. At 70 dB SPL, the only hearing aid condition that resulted in larger N1-P2 amplitudes (compared to unaided) was the Analog aid. There were also significant main effects for hearing aid type  = 6.99, ε = 0.95, P < 0.001) and for input level  = 74.97, ε = 1.00, P < 0.001). These findings indicate that the only 20 dB gain condition in which N1-P2 amplitudes were larger than unaided N1-P2 amplitudes occurred in the analog condition; even this result was not consistent across input levels. Additionally, response amplitudes in the DigitalB condition were significantly smaller than in all other aided and unaided conditions.In Figures F = 15.33, ε = 1.00, P < 0.001). Post hoc analysis showed that both digital hearing aids resulted in significantly delayed N1 latencies compared with unaided responses. In contrast, there was no significant difference between unaided and aided N1 latencies in Analog hearing aid conditions. There was also a significant main effect of input level  = 47.88, ε = 1.00, P < 0.001), such that response latencies were longer for the 50 compared with the 70 dB SPL input level. There was a nonsignificant trend  = 2.42, ε = 0.817, P = 0.096), such that latencies were the same in unaided and Analog hearing aid conditions for both input levels, but latencies for both digital hearing aids were longer compared with Analog and unaided conditions.F = 7.58, ε = 1.00, P < 0.001) and input level  = 115.26, ε = 1.00, P < 0.001), as well as a significant interaction between hearing aid type and input level  = 5.42, ε = 0.96, P = 0.004). Post hoc analysis showed that N1-P2 amplitudes were significantly smaller in DigitalB aided conditions compared with Analog and DigitalA. Additionally, post hoc analysis of the 40 dB gain results confirmed that N1-P2 amplitudes were larger for all three hearing aids at 50 dB SPL compared with unaided; however, no significant differences existed between N1-P2 amplitudes in aided and unaided conditions at the 30 dB SPL input level, and no significant differences existed between hearing aids at 30 dB SPL. Thus, despite being set with 40 dB of gain, N1-P2 amplitudes were never significantly larger for any of the 30 dB SPL aided conditions compared with unaided at 30 dB SPL.In Figures F = 5.57, ε = 1.00, P = 0.003). As is evident in Similar to findings for the 20 dB gain setting, N1 latencies for the 40 dB gain setting appear longer again, by as much as 10–15 ms, in the digital hearing aid conditions relative to the analog and unaided conditions. This seems to be the case for both 30 and 50 dB SPL input levels; however, as mentioned previously, the latencies for the 30 dB SPL input level were not included in the statistical analysis due to missing data. The ANOVA results revealed a statistically significant difference between hearing aid conditions  = 73.18, ε = 1.00, P < 0.001) and for input level  = 118.13, ε = 1.00, P < 0.001), as well as a significant interaction between gain setting and input level  = 7.32, ε = 1.00, P = 0.019). Post hoc analysis showed significantly larger N1-P2 amplitudes for the 40 dB gain setting compared with the 20 dB gain setting at 50 dB SPL; however, no significant difference existed between N1-P2 amplitudes for the two gain settings at the 30 dB SPL input level. The main effect for hearing aid type was also significant  = 6.01, ε = 1.00, P = 0.008), such that N1-P2 amplitudes were significantly smaller for DigitalB hearing aid condition compared with Analog and DigitalA hearing aid conditions. There was no significant interaction between hearing aid type and gain setting  = 1.02, ε = 1.00, P = 0.37), hearing aid type and input level  = 1.73, ε = 1.00, P = 0.20), or hearing aid type by gain setting by input level  = 0.41, ε = 1.00, P = 0.67). These results are consistent with findings reported previously that there is little to no effect of gain for the 30 dB SPL input level, but a significant effect of gain for the 50 dB SPL input level.In order to determine whether hearing aid gain had an effect on response amplitudes and/or latencies, results for the two gain settings (20 and 40 dB) were compared across input level (30 and 50 dB SPL for amplitude and 50 dB SPL for latency). It is evident in F = 13.66, ε = 1.00, P < 0.001), such that significantly shorter N1 latencies were obtained in Analog hearing aid conditions compared with either digital hearing aid. No significant main effect of gain setting existed for N1 latencies  = 0.46, ε = 1.00, P = 0.51), indicating that latencies for the 40 dB gain setting were not significantly shorter than latencies for the 20 dB gain setting. There was a nonsignificant trend for latencies to be shorter in the Analog hearing aid conditions compared with the digital hearing aid conditions across gain settings for the hearing aid type and gain interaction  = 2.92, ε = 1.00, P = 0.07).Latency results for the 20 and 40 dB gain settings in F = 14.75, ε = 0.89, P < 0.001). Post hoc analysis showed that N1 response amplitudes were significantly smaller for all hearing aid conditions  compared with the unaided condition . Although nominal output levels should have been equal, N1-P2 amplitudes obtained with the 50 dB SPL and 20 dB gain conditions were significantly larger than those obtained with the 30 dB SPL and 40 dB gain conditions for all hearing aid conditions except for DigitalB.A key question in this study was whether N1-P2 amplitudes would be the same when compared across unaided and aided conditions for the same nominal output level. More specifically, the 70 dB SPL input level for the unaided condition was compared with the 30 dB SPL input level for the 40 dB gain condition and the 50 dB SPL input level for the 20 dB gain condition, because all three combinations would be expected to yield a 70 dB SPL output in the ear canal. Grand mean waveforms for these three combinations of unaided and aided conditions are presented in The current study, carried out in participants with normal hearing, assessed the effects of processing of stimuli by three different hearing aids and two gain settings on SCP amplitudes and latencies. This differs from many previous studies in participants with hearing loss, where aided SCPs were obtained at levels where unaided stimuli were inaudible and unaided SCPs were absent. Results of the present study clearly demonstrate that, in many instances, introducing hearing aid gain had little or no effect on SCP N1-P2 measures, and, in some comparisons, SCP results worsened . Further, significant differences were found between different hearing aids. These findings are despite the fact that verification of REIG measures using conventional hearing aid test procedures in the present study confirmed all three hearing aids provided 20 and 40 dB of gain at input levels used in testing for all subjects.There has been much interest in using the slow cortical potential as an objective hearing aid measure, especially recently; however, there is clearly conflicting evidence in the literature regarding the accuracy of the SCP for this purpose. Most research indicates that SCPs can indeed be recorded in response to hearing-aid-processed stimuli –33. StudSome studies suggest that different cortical responses for different speech stimuli are maintained in aided conditions –30. HoweSeveral studies in individuals with normal hearing, including the present study, have assessed several aspects of input stimuli and/or hearing aid parameters, including input intensity  thaThe current study is the first study to assess the effects of amplification by different hearing aids on the SCP. Specifically, the current study investigated SCP responses to stimuli processed by an analog hearing aid, as well as two digital hearing aids from two different manufacturers, all set to provide the same amount of gain. To simplify comparisons, all three hearing aids were set to linear processing, with additional processing features  tuned off. As noted previously, despite older technology, the analog hearing aid was included because almost all preceding reports of the SCP in response to hearing-aid-processed stimuli involved participants using analog hearing aids. Importantly, the results of the current study indicate significantly (and clearly) different effects on the SCP for the three different hearing aids, with the DigitalB hearing aid condition showing significantly smaller amplitudes than the other hearing aid conditions, both digital hearing aid conditions showing longer  latencies, and the Analog hearing aid showing larger SCP amplitudes than the digital hearing aid conditions.smaller SCP amplitudes (at 50 and 70 dB SPL) compared to unaided results. These results cannot be explained by SCP N1-P2 amplitude reaching a ceiling at higher intensities or the hearing aid reaching its maximum output, because discrepancies were seen at all intensities. Indeed, although previous research indicates increases in SCP amplitude and decreases in latency asymptote at higher intensities, for tonal stimuli these plateaus do not occur until at least 80–90 dB SPL , alt, altsmalL  and 2.3 ms  hearing aid delays indicated by the standard electroacoustic measures conducted using the Fonix 7000 System. We discuss this further in our following study .Concern has been raised about conclusions drawn from studies in individuals with normal hearing of aided versus unaided SCPs . It is possible that the internal noise of hearing aids could affect SCP results in subjects with normal hearing but would be below threshold in subjects with hearing loss. Alternatively, the hearing aids amplified ambient noise in the sound booth, which could possibly have detrimental effects on SCPs especially in normal listeners. Indeed, recent studies of the SCP indicate large effects of noise on the SCP, such that signal-to-noise ratio (SNR) may be a more determining factor than the absolute stimulus level , 36. We The implications of the current study, as well as other studies, are that SCP results do not always reflect the expected  gain of hearing aids, and that different hearing aids with similar electroacoustic parameters  may result in substantially different SCP results. Thus, it would be possible that an appropriately fitted hearing aid (for degree and configuration of the hearing loss) in a client may either show no SCP response or no improvement from the unaided SCP response, even though behaviourally the client shows clear improvement. Similarly, changing hearing aid setting may not change the SCP. Finally, changing the type or brand of hearing aid may result in substantial SCP differences, even though standard electroacoustic measures indicate no change.There is much interest in the audiology community in the use of the SCP in the hearing-aid fitting process for infants with hearing loss. The results of the current study  indicate the SCP may not accurately reflect the gain expected from the prescribed hearing aids. Thus, aided-SCP results must be cautiously interpreted when used clinically. A “present” SCP may be interpreted as indicating that the individual's auditory cortex has responded to the hearing-aid-processed stimuli; however, as Dillon and colleagues have recently cautioned, “this does not necessarily indicate that the hearing aids are providing effective amplification” . ImportaClearly, more research concerning the “aided-SCP” technique is required. Importantly, among the needed studies are assessments of the effects of hearing aid processing on the acoustics of the stimuli used to elicit the SCP. Until now, it has been assumed that the longer durations of SCP stimuli allow for adequate processing by hearing aids. SCP stimuli have been contrasted to the much shorter click and brief-tone stimuli required for ABR testing, which were too brief for hearing aid processing and thus did not result in valid measurements of hearing aid gain or output –11. The


Substance P-immunoreactive nerve fiber (SP-IR NF) and calcitonin gene-related peptide-immunoreactive nerve fiber (CGRP-IR NF) are important mediators of neurogenic inflammation and blood supply. SP-IR and CGRP-IR NFs in the tensor tympani muscle (TTM) of the human middle ear have yet to be described. In this study, the TTM, tympanic membrane, malleus in the middle ear and tensor veli palatini muscle (TVPM) were examined by whole-mount immunohistochemistry in tissue from Japanese subjects. Thirteen human cadavers (ranging in age from 46 to 90 years) were used in this study. SP-IR and CGRP-IR NFs were primarily found on vessels at the origin, insertion and belly of the surface of the TTM and on the internal surface of the tympanic membrane. These neural factors were also detected on the surface of the malleus and the insertion of the TVPM. Therefore, our results indicate that existence of the SP-IR and CGRP-IR NFs of the TTM and the TVPM may reflect muscle properties involved in pain or inflammation of the middle ear. Substance P-immunoreactive nerve fiber (SP-IR NF) and calcitonin gene-related peptide-immunoreactive nerve fiber (CGRP-IR NF) have been found in humans and other species in connective tissue beneath epithelium, around blood vessels, in the nasal mucosa and in the mucous glands in the respiratory tract –7. SP-IRn = 5, 70.8 ± 15.6; female, n = 8, 80.5 ± 12.6 years old) were examined. All human cadavers had been donated for dissection. Samples were injected with 10 % formalin with return perfusion via the femoral artery. After anatomical dissection, the middle ear (including the TTM and the TVPM) was removed from the temporal bone  for 1 h at 38 °C. After overnight fixation in 4 % paraformaldehyde, the samples were washed with distilled water for 50 min, and the proteinase K digestion and overnight fixation steps were repeated. The samples were then washed with phosphate-buffered saline (PBS) for 30 min and sequentially incubated in 2.5, 5 and 10 % sucrose in PBS (1 h for each stage). After overnight incubation at 4 °C in PBS containing 2 % Triton X-100, the samples were washed with PBS (1 h for each wash) and incubated for 1 h at room temperature with 2 % normal goat serum/PBS (pH 7.2) containing 0.05 % Tween 20 to prevent non-specific antibody binding. Right middle ear samples were then incubated for 2 days at 4 °C with rabbit polyclonal antibodies against SP  and CGRP  or with normal goat serum as the negative control (left middle ears). The samples were then washed three times with PBS for 1 h each wash. Whole-mount samples were incubated with horseradish peroxidase-conjugated goat anti-rabbit IgG  following the manufacturer’s instructions. The samples were then washed with PBS three times for 1 h. The staining was visualized using 0.02 % H2O2 and 0.1 % (1 mg/ml) diaminobenzidine tetrahydrochloride in 0.1 M Tris–HCl, pH 7.2. Appropriate negative controls were included. Images were acquired using a stereomicroscope  with the Leica Application Suite software (Leica Microsystems).Whole-mount specimens were washed with distilled water for 24 h, incubated with 3 % HCadavers were obtained by consensual donation, according to guidelines from the law concerning body donation and the law concerning cadaver dissection and preservation.SP-IR NFs and CGRP-IR NFs were found around blood vessels located on the surface of the malleus bone, TM, TTM, and TVPM Figs. , 3. SP-IThe TTM arises from the cartilaginous part of the auditory tube and the sphenopetrosal fissure of the sphenoid bone and inserts into the basal handle of the malleus. The TTM is a small muscle that receives arterial blood supply from the epitympanum branch of the middle meningeal artery and that is controlled by the TTM branch of the medial pterygoid nerve . The TTMVater–Pacinian corpuscles  and two Our results indicated that SP-IR and CGRP-IR NFs are concentrated at the surface of the neck of the malleus near the TM forming anterior and posterior pouches in humans (Prussak’s pouch) . PrussakIn rat skeletal muscle, SP-IR and CGRP-IR NFs are more often found along blood vessels in the superficial muscle layers than in deep layers . The difThese sites are sensitive areas of the TTM and TVPM in the middle ear. SP and CGRP are considered to be important mediators of neurogenic inflammation . CGRP caOur results indicate that SP-IR NFs and CGRP-IR NFs are located in the connective areas between the two muscles. The existences of SP-IR NFs and CGRP-IR NFs may reflect muscle properties involved in pain or inflammation of the middle ear.


Objective. The aim of the study is to identify maternal needs of children with hearing impairment at two stages of habilitation, that is, just after diagnosis (group I) and after receiving 1 to 3 years of language therapy (group II). Methods. Two groups of mothers were asked to speak their queries about aural habilitation of their children. Queries were recorded, summarized, and categorized as per their priorities. Results. Group I mothers wanted to know about how the child would learn to listen and speak (45%), causes of hearing loss (33.7%), understanding the ear and hearing (10.2%), understanding the audiogram (7%), and coping with emotional aspects of hearing loss (5%), while group II parents had priorities concerning speech development (24.5%) followed by child independence and employment (17.3%), schooling (15.6%), problem behaviors (11%), amplification device (9.4%), duration of therapy (8%), future of the child (8%), and questions about how can my child get adjusted to the “normal” world (6%). Conclusions. Culture- and language-specific materials to explain these issues need to be developed.Counseling training in graduate programs continues to be underrepresented. If parental queries are not addressed adequately, they keep visiting one doctor after another.  Apt counseling may have a direct impact on the success of early hearing detection and intervention programs along with reducing the negative effects of permanent hearing loss –3. The clinician is confronted with a difficult task during the first few contacts with the parents because they are in a state of shock and they seek help in changing the child's behavior so that their anxiety can be dissipated . When asIn India, it is in part is also because of the undue influence of the medical model of treatment in dealing with permanent hearing loss (HI). Audiologists are influenced by the medical model and view HI as a “disease” to be cured, rather than a “condition” with which the child and the family have to live with for the rest of their life. The audiologist many times feels there job is done with the diagnosis of the hearing loss and the prescription of the hearing aid. Counseling involves briefing out the findings of the hearing loss and the control switches of a hearing aid. If the counseling is done keeping view of the social model, the parents and family needs are considered first and the information is provided depending upon their priorities, rather than briefing findings which seem to be important to the counselor. There has been a recurring emphasis on the need for more empathetic behavior by professionals and the need for them to have a greater understanding of the emotional impact of the diagnosis on the family, which does not receive due attention , 8–10. IThe scenario in countries like America is quite different from India. In India a universal newborn hearing screening program is yet to be implemented at national level. Unlike in west habilitation initiatives are taken up by parents and the mean age of detection of hearing loss is about 3.03 (SD: ±1.3) years and aural habilitation begins by a mean age of 7.36 (SD: ±4.06) years . Majorit The aim of the study is to identify the maternal needs of children with hearing impairment at two stages of habilitation, that is, just after diagnosis and after receiving 1 to 3 years of speech and language therapy. Understanding the needs would promote developing focused counseling strategies at different stages of aural habilitation which in turn will facilitate the process.The participants of the study included two groups of mothers of children with severe-to-profound-degree of hearing loss. The mother's ages ranged from 21 to 38 years. All the mothers belonged to the middle socio economic strata with an income of less than 6500 rupees per month. All the children had bilateral severe-profound sensory neural hearing loss and had been prescribed a strong class body-worn hearing aid. The hearing aids were issued free of cost under ADIP (assistance to disabled persons for purchase/fitting of aids and appliances) scheme of Government of India . Group I included forty-nine mothers in the mean age range of 31.5 years (SD: ±2.72) whose children had recently been diagnosed with hearing loss and Group II consisted of a random sample of 52 mothers with a mean age of 37.3 years (SD: ±3.62) whose children were receiving speech and language therapeutic intervention since last 1 to 3 years. All the children aged between 3 and 8 years with a mean age 4.21 (SD: ±1.13) years. The mothers in both groups had received formal education up to class Xth or more. The interview was carried out in a one-to-one setting in Bengali or Hindi language, whichever was the native language of the participant. The average time taken in an interview ranged from 20–25 minutes. Consent was obtained from the mothers after explaining to them the purpose of the study. The queries of group I mothers were placed under five major categories after tabulation. The five major categories included causes of hearing loss, coping with emotional aspects of hearing loss, understanding the audiogram, learning to listen and speak, and understanding the ear and hearingThe queries of group II mothers could be placed under eight major categories. The eight major categories included speech and language development of the child, schooling, can my child get adjusted to the “normal” world, problem behaviors, like restlessness, lack of attention, and so forth, amplification device, duration of therapy, future of the child and child independence and employment.After explaining the aim of the study, the participants were instructed to write down queries regarding their child's habilitation. The written queries were collected and tabulated. A total of 305 queries were obtained.  Statistical analysis was carried out using statistical package for social science (SPSS) for windows (version 11) software.  Descriptive analysis was used to estimate the percentage occurrence of responses to each question item in each category. The categories were analyzed in terms of number of times each category was asked by the parents and was ranked accordingly. The percentage of distribution of queries and priorities occurring in each category for both the groups is listed in Figures There are four major ways in which hearing loss affects children. It causes delay in the development of receptive and expressive communication skills (speech and language), the language deficit causes learning problems that result in reduced academic achievement, communication difficulties often lead to social isolation and poor self-concept, and it may have an impact on vocational choices . Hence qIn the present study mothers were selected as participants because they commonly accompanied the child for therapy. Fathers went out for jobs to meet the financial needs of the family. During the first counseling session after diagnosis when both the parents were present, most of the mothers found difficulty in understanding the technicalities of the hearing aid and the hearing loss which their child had. Sweetow and Barrager (1980), via use of a questionnaire survey, attempted to study the need for the audiologist to translate complicated terminology into language easily understood by the parents and the need for written information related to hearing impairment to be dispersed was repeatedly stressed .A survey by Roush and Harrison  identifi Understanding the ear and hearing was another frequently stated category and has been ranked as third priority. Even though parents may differ in the level of information they desire, almost all are interested in knowing at least basics about the structure and function of the ear. Simple diagrams and models are most helpful in explaining the various parts of ear. Working of the ear and its parts can be best explained through analogies. Analogies of the funnel are found useful in explaining the function of the external ear, the external ear collects sounds and sends them to the middle ear. The middle ear has an ear drum and three bones which pass the sound into the inner ear. Tympanic membrane or ear drum is the first part of the middle ear which collects the sound and passes it to the middle ear bones. It is a common notion in India that hearing loss is due to a defective ear drum. Parents need an explaination about the ear drum and its status and its contribution if any to their child's hearing loss. The middle ear functions like a voltage stabilizer which mostly increases the sound pressure level for better hearing and protects the ear from loud sounds by decreasing the loud sounds before they reach the inner ear. The inner ear is like a harmonium or piano with high-frequency sound receptors basally and low-frequency receptors apically. These receptors are known as hair cells. Most of the children with sensory neural hearing loss have damaged hair cells. The hair cells code sounds into electrical impulses. These electrical impulses are carried by the auditory nerve and further by the central auditory pathway; both function like electric wires. The auditory pathway delivers the electrical impulses to the auditory cortex. The auditory cortex decodes the electrical impulses into meaningful information and the sound is perceived. Once the normal functioning of the ear is explained using the analogies, parents can be pointed to the area which is damaged for their child and how the intervention strategy (like a hearing aid) would help the child. The fourth priority category was understanding the audiogram. Parents may be unable to fully understand their child's hearing loss, as shown by an audiogram. Acknowledgment by the audiologist that the audiogram is abstract and difficult to comprehend may cause parents to feel more uncomfortable asking questions. Moreover, it is important to recognize that most families and parents are not interested in the audiogram per se, but rather what it can tell them about their child's hearing. An audiogram with a speech banana on it along with the intensities of various commonly found sounds in the environment helps parents understand their child's hearing. A portable sound-level meter is also found to be useful in helping the parents understand the various intensities of common sounds like name call, clap, door knock, telephone ring, and so forth. The average sound levels in the sound-treated rooms can also be included to give them an idea about the “quietest” environment .Coping with emotional aspects of hearing loss was also selected as an important category and was ranked as fifth information priority by mothers. There has been a recurring emphasis on the need for more empathetic behavior by professionals and the need for them to have a greater understanding of the emotional impact of the diagnosis on the family . This isA few months after diagnosis of hearing loss, parents' priorities were all related to developing their child's ability to communicate effectively and to early-intervention services . In the http://www.ccdisabilities.nic.in/). The identified jobs are reviewed every 3 years and new jobs are added to the list. About 1% government jobs are reserved for the individuals with HI. The NHFDC  provides financial assistance to individuals with HI ranging from 6,500 rupees to 25 lacks to start to develop their own business. There are 3% reservations for the disabled population in all educational institutes including training centers and technical training institutes. Individuals with HI can avail a travel train concession of 50% along with one escort who also gets the same benefit. The second priority was the query about the child independence and employment and, “future of the child” was the seventh priority. Parents need to be briefed about the various provisions provided to the individuals with hearing impairment (HI) by the Government of India . The GovThe second category “schooling” was ranked as the third priority by the mothers. It has been reported that parents want information about the full range of intervention options and ramifications of the hearing loss on education . ChildreThe fourth category “problem behaviors like restlessness, lack of attention, and so forth” was rated as the 4th priority by the mothers. Restlessness, one of the most commonly seen problem behaviors in children with hearing loss, can mostly be attributed to their impaired communication skills. Children with severe-to-profound hearing loss often tend to become more physical rather than being verbally persuasive. For instance a 3-4-year-old child often persuades his/her peer with a toy which he/she needs; the better the child can verbally persuade the easier it is for him/her to obtain the toy without snatching it. On the other hand a deaf child of the same age may ask for the toy using gestures and/or some rudimentary commands and may not be capable of convincing the peer; consequently he/she may try to physically snatch the toy. Similarly the child with hearing impairment may miss the classroom discourse and lose interest in the classroom activities and engage in “actions” which are labeled as problem behavior by the teacher.  “Amplification device” was rated as the fifth priority by the mothers. All the participants in the study had been dispensed a body-level hearing aids; however the parents wanted to know about the efficacy of the behind-the-level hearing aids, the digital aids, and the advantages of the cochlear implant for their child. Apart from the cosmetic appeal, parents often find it easy to understand the advantage of the behind-the-ear hearing aid when the concept of localization and the fact that the “ear” is placed closer to the ear in the behind the-ear-hearing aids is explained to them. Digital signal processing and its advantage are quiet easily understood if parents receive an explanation about the capability of a digital aid to manipulate and modify the incoming signal as per the listening needs of the user. Thus the digital processing of the incoming signal helps to reduce noise, enhance speech signal, and the hearing aid automatically changes the strength and the direction of the amplification based on the source of noise. There are additional facilities of in situ measurements. Hearing aids should be preferably purchased from outlets which offer good after-sales service. Cochlear implants are gaining popularity in India. Mothers are quiet curious about the cochlear implants. However mothers need to be explained that not all severe-to-profound hearing impaired children are candidates for cochlear implants. A cochlear implant is used only when children fail to develop simple auditory skills after consistently using binaural hearing aids along with auditory training for a period of six months. Many parents feel that the cochlear implant unlike a hearing aid is completely implanted/invisible and returns back the child's audibility to “normal.” It should be elaborated that the child needs regular intensive habilitation and recurring cost of speech and language therapy even after implantation.The sixth priority was the category “duration of therapy.” A general guideline of time duration for achieving target speech behaviors can be obtained from the developmental tool for speech and language development. For instance, if a “normally” developing child takes 6 months to more from one-word to phrase level a child with hearing impairment will take a minimum of six-month time. But as the child has an impaired auditory system, which even after being aided does not give the same sound perception as a un impaired ear thus the child takes a longer. The progress of the child is influenced by other factors like hearing age of the child, the amount of aided benefit if the presence of additional handicapping conditions, and so forth.The third category “social adjustment” was ranked as the eighth and last priority across all the interviewed mothers. Children with severe-to-profound hearing losses often report feeling isolated, without friends, and unhappy in school, particularly when their socialization with other children with hearing loss is limited. These social problems appear to be more frequent in children with mild or moderate hearing losses than in those with a severe-to-profound loss . In IndiCounseling sessions should help mothers to answer questions like, what is wrong with the child, will he wear the hearing aid for his entire life does he have intelligence as his peers, will “normal” children get affected if they play with the HI child, the child does not respond when called from a distance even after putting the hearing aid what is the use of the hearing aid, why does he talk like this, can he support himself and his family when he/she grows old, can she ever get married, and so forth. The mothers need to be explained how to describe the peers about the hearing aid, how it helps the child and why it should not be played with.


Carbon monoxide poisoning is one of the rare causes of hearing loss which may cause reversible or irreversible, unilateral or bilateral hearing loss after acute or chronic exposure. In this report, we present a case of bilateral sensorineural hearing loss in a secondary smelting workshop worker after an acute exposure to carbon monoxide. This complication was diagnosed by pure-tone audiometry and confirmed by transient evoked otoacoustic emissions. Hearing loss has not improved after 3 months of followup. Carbon monoxide (CO) is a colorless, odorless, and nonirritant gas which is a common cause of mortality due to acute poisoning . This gaThe symptoms of CO poisoning are nonspecific . Acute mOur case was a 22-year-old male working in a secondary smelting workshop in a rotating shift schedule. He was healthy without any history of hearing loss in his preplacement evaluations. The night before his admission, he had worked the night shift of the factory. In the morning, his coworkers found him unconscious. Immediately, he was brought unconscious to the hospital. After intubation, fluid therapy was begun, and he was transferred to the intensive care unit. His vital signs at admission were as follows: pulse rate: 115 beats/min; respiratory rate: 14/min; blood pressure: 115/80 mmHg; temperature: 37.3°C. His Glasgow Coma Scale at that time was 10. The results of arterial blood gas analysis taken at admission are presented in 2 therapy was not available in that hospital center at the time. After history taking, the diagnosis of CO poisoning was suggested for him, and oxygen therapy via face mask (15 lit/min) was immediately started. Hyperbaric OChest X-ray showed unilateral consolidation and signs of pulmonary edema. His brain computed tomography scan demonstrated mild brain edema.The patient became conscious after 4 days. After consciousness, he complained of hearing impairment without vertigo or tinnitus. He did not have any history of hearing loss, head trauma, loud noise exposure, and exposure to ototoxic drugs or substances. External ear canal and tympanic membrane examination was normal. Afterwards, the assessment of his auditory system was performed using pure-tone audiometry (PTA), tympanometry, and transient evoked otoacoustic emissions (TEOAEs). The PTA showed bilateral mid- to high-frequency sensorineural hearing loss. He was discharged from the hospital after 8 days without any complications except for the hearing loss. Before being discharged, a written informed consent was obtained from the patient for the presentation of his disorder. Audiometric assessments after 1, 2, and 3 months did not show any improvements in his hearing level. Acute or chronic exposure to CO is one of the known but rare causes of hearing loss . This kiCO-induced hearing loss mostly affects high frequencies, but further exposure to CO may affect low frequencies as well. If it is reversible, improvement is observed first in low frequencies . ConsistAfter 3 months of followup, there were not any detectible improvements in the patient's hearing condition. Unlike our patient and the cases reported by Pillion  and SkrzHearing evaluation is not routinely performed in patients who suffer from CO poisoning. This case showed that hearing assessment should be integrated into the clinical evaluations of brain injury due to CO poisoning.