scholarly journals Sound: production, perception, hearing loss & treatment options

Author(s):  
Bibi Kulsoom ◽  
Nasim Karim

Sound is an important communication tool for humans that contain information about the surrounding environment. It may signify a danger or a reward for an organism. In humans, the mechanism of sound production and perception is complex and sophisticated. Sound is produced by vibrating body in a medium that contains molecules in the surrounding space. The sound perception starts in human foetus at around the third trimester where it plays a vital role in organising the foetal brain. This process continues after birth and can be exploited by various endogenous and exogenous factors. Many mechanisms that can modulate hearing process at different levels lead to subclinical or clinical presentation of hearing-related problems. It is important to contemplate the mechanisms underlying sound production, perception and pathogenesis of hearing loss. This will facilitate prescribing a relevant treatment option according to the cause and its underlying mechanism. --Continue

2018 ◽  
Vol 39 (04) ◽  
pp. 349-363 ◽  
Author(s):  
Eric Hoover ◽  
Pamela Souza

AbstractSubstantial loss of cochlear function is required to elevate pure-tone thresholds to the severe hearing loss range; yet, individuals with severe or profound hearing loss continue to rely on hearing for communication. Despite the impairment, sufficient information is encoded at the periphery to make acoustic hearing a viable option. However, the probability of significant cochlear and/or neural damage associated with the loss has consequences for sound perception and speech recognition. These consequences include degraded frequency selectivity, which can be assessed with tests including psychoacoustic tuning curves and broadband rippled stimuli. Because speech recognition depends on the ability to resolve frequency detail, a listener with severe hearing loss is likely to have impaired communication in both quiet and noisy environments. However, the extent of the impairment varies widely among individuals. A better understanding of the fundamental abilities of listeners with severe and profound hearing loss and the consequences of those abilities for communication can support directed treatment options in this population.


2021 ◽  
Vol 22 (12) ◽  
pp. 6497
Author(s):  
Anna Ghilardi ◽  
Alberto Diana ◽  
Renato Bacchetta ◽  
Nadia Santo ◽  
Miriam Ascagni ◽  
...  

The last decade has witnessed the identification of several families affected by hereditary non-syndromic hearing loss (NSHL) caused by mutations in the SMPX gene and the loss of function has been suggested as the underlying mechanism. In the attempt to confirm this hypothesis we generated an Smpx-deficient zebrafish model, pointing out its crucial role in proper inner ear development. Indeed, a marked decrease in the number of kinocilia together with structural alterations of the stereocilia and the kinocilium itself in the hair cells of the inner ear were observed. We also report the impairment of the mechanotransduction by the hair cells, making SMPX a potential key player in the construction of the machinery necessary for sound detection. This wealth of evidence provides the first possible explanation for hearing loss in SMPX-mutated patients. Additionally, we observed a clear muscular phenotype consisting of the defective organization and functioning of muscle fibers, strongly suggesting a potential role for the protein in the development of muscle fibers. This piece of evidence highlights the need for more in-depth analyses in search for possible correlations between SMPX mutations and muscular disorders in humans, thus potentially turning this non-syndromic hearing loss-associated gene into the genetic cause of dysfunctions characterized by more than one symptom, making SMPX a novel syndromic gene.


Nutrients ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 555
Author(s):  
Soyoung Hur ◽  
Eungyeong Jang ◽  
Jang-Hoon Lee

Tumors are one of the most life-threatening diseases, and a variety of cancer treatment options have been continuously introduced in order to overcome cancer and improve conventional therapy. Orostachys japonica (O. japonica), which is a perennial plant belonging to the genus Orostachys of the Crassulaceae family, has been revealed to exhibit pharmacological properties against various tumors in numerous studies. The present review aimed to discuss the biological actions and underlying molecular mechanisms of O. japonica and its representative compounds—kaempferol and quercetin—against tumors. O. japonica reportedly has antiproliferative, anti-angiogenic, and antimetastatic activities against various types of malignant tumors through the induction of apoptosis and cell cycle arrest, a blockade of downstream vascular endothelial growth factor (VEGF)-VEGFR2 pathways, and the regulation of epithelial-to-mesenchymal transition. In addition, emerging studies have highlighted the antitumor efficacy of kaempferol and quercetin. Interestingly, it was found that alterations of the mitogen-activated protein kinase (MAPK) signaling cascades are involved in the pivotal mechanisms of the antitumor effects of O. japonica and its two compounds against cancer cell overgrowth, angiogenesis, and metastasis. In summary, O. japonica could be considered a preventive and therapeutic medicinal plant which exhibits antitumor actions by reversing altered patterns of MAPK cascades, and kaempferol and quercetin might be potential components that can contribute to the efficacy and underlying mechanism of O. japonica.


Cancers ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 3740
Author(s):  
Chunye Zhang ◽  
Ming Yang

Hepatocellular carcinoma (HCC) is the most common type of primary liver cancer, followed by cholangiocarcinoma (CCA). HCC is the third most common cause of cancer death worldwide, and its incidence is rising, associated with an increased prevalence of obesity and nonalcoholic fatty liver disease (NAFLD). However, current treatment options are limited. Genetic factors and epigenetic factors, influenced by age and environment, significantly impact the initiation and progression of NAFLD-related HCC. In addition, both transcriptional factors and post-transcriptional modification are critically important for the development of HCC in the fatty liver under inflammatory and fibrotic conditions. The early diagnosis of liver cancer predicts curative treatment and longer survival. However, clinical HCC cases are commonly found in a very late stage due to the asymptomatic nature of the early stage of NAFLD-related HCC. The development of diagnostic methods and novel biomarkers, as well as the combined evaluation algorithm and artificial intelligence, support the early and precise diagnosis of NAFLD-related HCC, and timely monitoring during its progression. Treatment options for HCC and NAFLD-related HCC include immunotherapy, CAR T cell therapy, peptide treatment, bariatric surgery, anti-fibrotic treatment, and so on. Overall, the incidence of NAFLD-related HCC is increasing, and a better understanding of the underlying mechanism implicated in the progression of NAFLD-related HCC is essential for improving treatment and prognosis.


2015 ◽  
Vol 2015 ◽  
pp. 1-5 ◽  
Author(s):  
Michelle Kohansieh ◽  
Amgad N. Makaryus

Sleep plays a vital role in an individual’s mental, emotional, and physiological well-being. Not only does sleep deficiency lead to neurological and psychological disorders, but also the literature has explored the adverse effects of sleep deficiency on the cardiovascular system. Decreased quantity and quality of sleep have been linked to cardiovascular disease (CVD) risk factors, such as hypertension, obesity, diabetes, and dyslipidemia. We explore the literature correlating primary sleep deficiency and deprivation as a cause for cardiovascular disease and cite endothelial dysfunction as a common underlying mechanism.


2021 ◽  
Vol 14 ◽  
pp. 175628642098135
Author(s):  
Barbara Willekens ◽  
Ilka Kleffner

Susac syndrome (SuS) is a rare autoimmune endotheliopathy leading to hearing loss, branch retinal artery occlusions and encephalopathy. Young females are more frequently affected than males, making counselling for family planning an important issue. We reviewed published cases on SuS during pregnancy or in the postpartum period, and selected 27 reports describing the details of 33 patients with SuS. Treatment options and implications for pregnancy and breastfeeding are discussed. We propose new areas for research and suggest a management strategy.


2014 ◽  
Vol 23 (2) ◽  
pp. 91-104 ◽  
Author(s):  
Sophie E. Ambrose ◽  
Lauren M. Unflat Berry ◽  
Elizabeth A. Walker ◽  
Melody Harrison ◽  
Jacob Oleson ◽  
...  

Purpose The purpose of the study was to (a) compare the speech sound production abilities of 2-year-old children who are hard of hearing (HH) to children with normal hearing (NH), (b) identify sources of risk for individual children who are HH, and (c) determine whether speech sound production skills at age 2 were predictive of speech sound production skills at age 3. Method Seventy children with bilateral, mild-to-severe hearing loss who use hearing aids and 37 age- and socioeconomic status–matched children with NH participated. Children's speech sound production abilities were assessed at 2 and 3 years of age. Results At age 2, the HH group demonstrated vowel production abilities on par with their NH peers but weaker consonant production abilities. Within the HH group, better outcomes were associated with hearing aid fittings by 6 months of age, hearing loss of less than 45 dB HL, stronger vocabulary scores, and being female. Positive relationships existed between children's speech sound production abilities at 2 and 3 years of age. Conclusion Assessment of early speech sound production abilities in combination with demographic, audiologic, and linguistic variables may be useful in identifying HH children who are at risk for delays in speech sound production.


mBio ◽  
2019 ◽  
Vol 10 (6) ◽  
Author(s):  
Chengjun Cao ◽  
Yina Wang ◽  
Seema Husain ◽  
Patricia Soteropoulos ◽  
Chaoyang Xue

ABSTRACT Echinocandins show fungicidal activity against common invasive mycoses but are ineffective against cryptococcosis. The underlying mechanism for echinocandin resistance in Cryptococcus neoformans remains poorly understood but has been shown to involve Cdc50, the regulatory subunit of lipid flippase. In a forward genetic screen for cdc50Δ suppressor mutations that are caspofungin resistant, we identified Crm1 (caspofungin resistant mutation 1), a homolog of mechanosensitive channel proteins, and showed that crm1Δ restored caspofungin resistance in cdc50Δ cells. Caspofungin-treated cdc50Δ cells exhibited abnormally high intracellular calcium levels ([Ca2+]c) and heightened activation of the calcineurin pathway. Deletion of CRM1 in the cdc50Δ background normalized the abnormally high [Ca2+]c. Cdc50 interacts with Crm1 to maintain cellular calcium homeostasis. Analysis of chitin/chitosan content showed that deleting CRM1 reversed the decreased chitosan production of cdc50Δ cells. Together, these results demonstrate that Cdc50 and Crm1 regulation of the calcineurin pathway and cytoplasmic calcium homeostasis may underlie caspofungin resistance in C. neoformans. IMPORTANCE Cryptococcus neoformans is the leading cause of fungal meningitis, accounting for ∼15% of HIV/AIDS-related deaths, but treatment options for cryptococcosis are limited. Echinocandins are the newest fungicidal drug class introduced but are ineffective in treating cryptococcosis. Our previous study identified the lipid flippase subunit Cdc50 as a contributor to echinocandin resistance in C. neoformans. Here, we further elucidated the mechanism of Cdc50-mediated caspofungin drug resistance. We discovered that Cdc50 interacts with the mechanosensitive calcium channel protein Crm1 to regulate calcium homeostasis and caspofungin resistance via calcium/calcineurin signaling. These results provide novel insights into echinocandin resistance in this pathogen, which may lead to new treatment options, as well as inform echinocandin resistance mechanisms in other fungal organisms and, hence, advance our understanding of modes of antifungal drug susceptibility and resistance.


1993 ◽  
Vol 107 (11) ◽  
pp. 1034-1036 ◽  
Author(s):  
Ratna Thomas ◽  
Mohan Kameswaran ◽  
Vel Murugan ◽  
B. C. Okafor

AbstractA case of neurobrucellosis presenting to the otologist with sensorineural hearing loss (SNHL) as the predominant clinical feature is reported. The diagnostic features and treatment options are discussed and the need for prolonged combination treatment to prevent relapse and further deterioration of hearing stressed. SNHL in neurobrucellosis has hitherto been reported principally in neurology literature as something of an incidental finding and so escapes the attention of otologists. It is hoped that this report will alert otologists in areas where brucellosis is endemic to the need to include tests for brucellosis in the routine diagnostic screening for SNHL. Practitioners in other locations should also consider this possibility when dealing with patients who have visited or lived in endemic regions.


Author(s):  
Jahnavi Sarvepalli ◽  
Rajalakshmi Santhakumar ◽  
Rama Shanker Verma

The incidence of cardiovascular disease (CVD) in adults are increasing worldwide with impaired repair mechanisms, leading to tissue and organ failure. With the current advancements, life expectancy has improved and has led to search for new treatment strategies that improves tissue regeneration. Recently, stem cell therapy and tissue engineering has captured the attention of clinicians, scientists, and patients as alternative treatment options. The overall clinical experience of these suggests that they can be safely used in the right clinical setting. Ultimately, large outcome trials will have to be conducted to assess their efficacy. Clinical trials have to be carefully designed and patient safety must remain the key concern. At the same time, continued basic research is required to understand the underlying mechanism of cell-based therapies and cell tissue interactions. This chapter reviews the evolving paradigm of stem cell therapy and tissue engineering approaches for clinical application and explores its implications.


Sign in / Sign up

Export Citation Format

Share Document