Organ of Corti and Stria Vascularis: Is there an Interdependence for Survival?

by Huizhan Liu, Yi Li, Lei Chen, Qian Zhang, Ning Pan, David H. Nichols, Weiping J. Zhang, Bernd Fritzsch, David Z. Z. He

Cochlear hair cells and the stria vascularis are critical for normal hearing. Hair cells transduce mechanical stimuli into electrical signals, whereas the stria is responsible for generating the endocochlear potential (EP), which is the driving force for hair cell mechanotransduction. We questioned whether hair cells and the stria interdepend for survival by using two mouse models. Atoh1 conditional knockout mice, which lose all hair cells within four weeks after birth, were used to determine whether the absence of hair cells would affect function and survival of stria. We showed that stria morphology and EP remained normal for long time despite a complete loss of all hair cells. We then used a mouse model that has an abnormal stria morphology and function due to mutation of the Mitf gene to determine whether hair cells are able to survive and transduce sound signals without a normal electrochemical environment in the endolymph. A strial defect, reflected by missing intermediate cells in the stria and by reduction of EP, led to systematic outer hair cell death from the base to the apex after postnatal day 18. However, an 18-mV EP was sufficient for outer hair cell survival. Surprisingly, inner hair cell survival was less vulnerable to reduction of the EP. Our studies show that normal function of the stria is essential for adult outer hair cell survival, while the survival and normal function of the stria vascularis do not depend on functional hair cells.

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The effect of obesity, weight gain, and weight loss on asthma inception and control.

Purpose of review: There is ample and growing evidence that obesity increases the risk of asthma and morbidity from asthma. Here, we review recent clinical evidence supporting a causal link between obesity and asthma, and the mechanisms that may lead to 'obese asthma'. Recent findings: Although in some children obesity and asthma simply co-occur, those with 'obese asthma' have increased asthma severity, lower quality of life, and reduced medication response. Underlying mechanistic pathways may include anatomical changes of the airways such as obstruction and dysanapsis, systemic inflammation, production of adipokines, impaired glucose-insulin metabolism, altered nutrient levels, genetic and epigenetic changes, and alterations in the airway and/or gut microbiome. A few small studies have shown that weight loss interventions may lead to improvements in asthma outcomes, but thus far research on therapeutic interventions for these children has been limited. Summary: Obesity increases the risk of asthma - and worsens asthma severity or control - via multiple mechanisms. 'Obese asthma' is a complex, multifactorial phenotype in children. Obesity and its complications must be managed as part of the treatment of asthma in obese children. Copyright (C) 2016 Wolters Kluwer Health, Inc. All rights reserved.

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Microbes, allergic sensitization, and the natural history of asthma.

Purpose of review: Understanding factors that lead to asthma development in early life is essential to developing strategies aimed at primary or secondary prevention. Recent findings: This article will review current evidence addressing the development of early life allergic sensitization in relation to microbes and the gut and airway microbiome. Wheezing illnesses, particularly viral, remain a significant risk factor for asthma inception; however, bacterial pathogens have recently emerged as an additional important contributor to asthma risk, either alone or as cofactors with viral infections. The combined influence and interaction of early life viral wheezing and aeroallergen sensitization is important, with allergic sensitization preceding the onset of viral wheeze. Lastly, we review recent data from longitudinal studies regarding the development of irreversible airway obstruction and its impact on the natural history of asthma. Summary: The development of asthma remains complex and incompletely understood. There is interplay between genetic predisposition and environmental exposures, including allergens and microbes. Interventions aimed at these risk factors during the preschool years may prevent the longitudinal course of asthma progression to irreversible airway obstruction. Copyright (C) 2016 Wolters Kluwer Health, Inc. All rights reserved.

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Transitional cell carcinoma with extension of the renal vein and IVC tumor thrombus: report of three cases and literature review

Background: Transitional cell carcinoma (TCC) originating from the renal pelvis with a venous tumor thrombus is a rare entity. However, clinicians should be aware of it because of its high malignancy and poor prognosis.Case presentationHere, we report three cases of pathologically confirmed TCC originating from the renal pelvis with extension into the renal vein or inferior vena cava (IVC). Of these patients, two are males and one is female (58~73 years old). Their main symptom is flank pain; besides, gross hematuria and weight loss is observed in one of the patients. Computed tomography (CT) scan of the first patient revealed multiple space-occupying lesions in the left renal pelvis and left medium and lower ureter with a tumor thrombus in the left renal vein. CT scan of the second patient revealed a right renal mass and extension into the IVC. Abdominal magnetic resonance imaging (MRI) of the third patient showed a soft tissue mass in the region of the left renal sinus, and the signal of the soft tissue was observed in the left renal vein. The preoperative diagnoses of the first and third patient were TCC, while the second patient was renal cell carcinoma (RCC). Two patients with the preoperative diagnosis of TCC underwent laparoscopic radical nephroureterectomy with thrombectomy, and the other patient underwent radical nephrectomy with thrombectomy. The surgeries were successful. Although two of our patients underwent chemotherapy and radiotherapy, they died 2 and 19 months after the surgery, respectively. The other patient refused any adjuvant therapy and died 3 months after the operation. Conclusions: Compared to the extension of RCC to the renal vein or IVC, extension of TCC to the renal vein or IVC is rare. TCC with a venous tumor thrombus is often misdiagnosed as RCC. However, a correct preoperative or intraoperative diagnosis is of great importance to decide surgical strategy. Laparoscopic radical nephroureterectomy with thrombectomy may be a safe and feasible operative method in treatment of TCC with a renal vein thrombus. The prognosis of such cases is poor even if chemotherapy and radiotherapy are scheduled.

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Complementary and Alternative Medicine for Atopic Dermatitis

Many patients seek alternative treatments for atopic dermatitis, from acupuncture to various supplements. Which, if any, have sufficient evidence to recommend?
American Journal of Clinical Dermatology

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Postsurgical Infection: Administrative vs Registry Data Differ

Reports of postsurgical infection often disagreed between administrative records and a clinical registry, a new study has found.
Medscape Medical News

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Gene Activity Predicts Progression of Systemic Sclerosis

A 415-gene expression profile distinguished skin from patients with systemic sclerosis from healthy skin and predicted response to treatment a year sooner than did conventional skin-pinch testing.
Medscape Medical News

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