Exposure to industrial wideband noise increases connective tissue in the rat liver (original) (raw)
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Effect of Noise on Quality of Collagen Formed in Rat Skin Wound
2018
OBJECTIVE: To observe the effect of noise on quality of collagen formed in rat skin wounds. STUDY DESIGN: A Quasi experimental study. PLACE AND DURATION: At Anatomy Department of Al-Nafees Medical College & Hospital Isra University Islamabad Campus Pakistanand National Institute of Health (NIH) Islamabad from 25th June 2015 to 15th February 2016. METHODOLOGY: Thirty male Sprague Dawley rats were divided into control and experimental groups by convenient sampling. Each main group comprised of 15 rats. An incision of 2 cm was made on dorsal region of all rats. Control sub groups were left to heal with routine background noise exposure, while experimental sub groups underwent a 4h/day intermittent noise exposure of 85-95 dB, five days a week for two consecutive weeks. Five rats from each group were sacrificed on day 3, 7 and 14. Wounds were excised, fixed and processed for Masson’s Trichrome stain to see the maturation of collagen content. RESULTS: Mature collagen formed in rat skin wo...
Arquivos de Gastroenterologia, 2012
CONTEXT: Only a few studies evaluated the digestive alterations caused by low frequency noise (LFN) and most focused only on mucosal alterations. OBJECTIVES: To investigate the morphological injury of LFN-exposed gastric wall, beyond the epithelial layer. METHODS: Wistar rats were exposed to low frequency noise (LFN), during increasing periods, 1 to 13 weeks. A control group was kept in silence. Gastric specimens were studied using: (i) light microscopy with hematoxylin-eosin and immunostaining for collagens; (ii) transmission electron microscopy; (iii) morphometry allowing statistical analysis. RESULTS: Submucosa of all LFN-exposed animals exhibit increased thickness with fibrous proliferation. Transmission electron microscopy showed massive collagen deposition. Immunostaining identified collagen IV as responsible for the increased thickness. Morphometry allowed the demonstration of a significant difference of thickness between control and exposed groups. Vascular alterations inclu...
International journal of clinical and experimental pathology, 2013
Low-frequency noise (LFN) leads to the development of tissue fibrosis. We previously reported the development of myocardial and perivascular fibrosis and a reduction of cardiac connexin43 in rats, but data is lacking concerning the affected type of collagen as well as the ultrastructural myocardial modifications. The aim of this study was to quantify cardiac collagens I and III and to evaluate myocardial ultrastructural changes in Wistar rats exposed to LFN. Two groups of rats were considered: A LFN-exposed group with 8 rats continuously submitted to LFN during 3 months and a control group with 8 rats. The hearts were sectioned and the mid-ventricular fragment was selected. After immunohistochemical evaluation, quantification of the collagens and muscle were performed using the image J software in the left ventricle, interventricular septum and right ventricle and the collagen I/muscle and collagen III/muscle ratios were calculated. Transmission electron microscopy (TEM) was used to...
Increase of collagen in the rat heart induced by noise
Environment International, 1979
Rats were exposed to randomly applied noise impulses during their nightly active phase for up to half a year. The ventricular myocardium was studied by electron microscopy and estimation of hydroxyproline. A significant increase of collagen was found especially in the left ventricle. A combination of noise stress with an Mg-deficient diet enhanced the increase of myocardial collagen. Thus, Mg-deficiency and noise appears to act in a synergistic manner.
Environmental Research, 2005
Workers chronically exposed to high-intensity/low-frequency noise at textile plants show increased frequency of respiratory infections. This phenomenon prompted the herein investigation on the cytology of the bronchial epithelium of Wistar rats submitted to textile noise. Workplace noise from a cotton-mill room of a textile factory was recorded and reproduced in a sound-insulated animal room. The Wistar rats were submitted to a weekly schedule of noise treatment that was similar to that of the textile workers (8 h/day, 5 days/week). Scanning electron microscopy (SEM) was used to compare the fine morphology of the inner surface of the bronchi in noise-exposed and control rats. SEM quantitative cytology revealed that exposure to noise for 5-7 months caused inhibition in the natural expansion of the area occupied by ciliated cells on the bronchial epithelium as adult rats grow older. This difference between noise-exposed and age-matched control rats was statistically significant (Po0:05) and documents that the cytology of the rat bronchial epithelium is mildly altered by noise exposure. The decrease in the area of bronchial cilia may impair the mucociliar clearance of the respiratory airways and, thus, increase vulnerability to respiratory infection. r 2004 Elsevier Inc. All rights reserved.
ICBEN review of research on the biological effects of noise 2011-2014
Noise & health
The mandate of the International Commission on Biological Effects of Noise (ICBEN) is to promote a high level of scientific research concerning all aspects of noise-induced effects on human beings and animals. In this review, ICBEN team chairs and co-chairs summarize relevant findings, publications, developments, and policies related to the biological effects of noise, with a focus on the period 2011-2014 and for the following topics: Noise-induced hearing loss; nonauditory effects of noise; effects of noise on performance and behavior; effects of noise on sleep; community response to noise; and interactions with other agents and contextual factors. Occupational settings and transport have been identified as the most prominent sources of noise that affect health. These reviews demonstrate that noise is a prevalent and often underestimated threat for both auditory and nonauditory health and that strategies for the prevention of noise and its associated negative health consequences ar...
Histomorphometric evaluation of the coronary artery vessels in rats submitted to industrial noise
Acta cardiologica, 2013
Industrial noise (IN) is characterized by high intensity and a wide spectrum of wavelengths that induce physical vibration on the body structures. This effect, resulting from the low-frequency sound waves, can lead to pathological alterations in the extracellular matrix with an abnormal proliferation of collagen and development of tissue fibrosis, in the absence of an inflammatory process. The aim of this study was to evaluate the modifications of the arterial coronary vessels in Wistar rats submitted to IN. Two groups of rats were considered: group A with 20 rats exposed to IN during a maximum period of 7 months; group B with 20 rats as age-matched controls.The hearts were sectioned from the ventricular apex to the atria and the mid-ventricular fragment was selected. Haematoxylin-eosin and Masson's trichrome staining were used for histological observation. Histomorphometric evaluation of the coronary vessels was performed using the computer image analysis ImageJsoftware. The me...
2013
BACKGROUND: Vibroacoustic disease (VAD) is a systemic pathology caused by excessive exposure to low frequency noise (LFN). Until 1987, it was thought that the pathological effects of excessive LFN exposure were limited to the realm of cognitive and neurological disturbances. After the autopsy findings in a deceased VAD patient, it became clear that LFN impinges on the entire body, particularly the cardio-respiratory systems. In 1992, rodents were exposed to LFN, and the respiratory tract was studied through scanning and transmission electron microscopy. Pericardial, tracheal and lung fragments, removed with informed consent from VAD patients, have also been studied with light and electron microscopy. This report summarizes what is known to date on the tissue and cellular response to LFN exposure. TUBULIN-BASED STRUCTURES: Cilia are tubulin-based and exist in normal pericardia as well as in the respiratory tract. In VAD patients, pericardial cilia cease to exist, while tracheal and b...
Myocardial fibrosis in rats exposed to low frequency noise
Acta cardiologica, 2013
Low frequency noise (LFN) characterized by large pressure amplitude (> or =90 dB SPL) and low frequency bands (< or =500 Hz) can lead to structural and ultrastructural modifications in the extracellular matrix of several tissues, with an abnormal proliferation of collagen and development of fibrosis. It is not known whether LFN induces similar structural alterations in the ventricular myocardium of rats. The aim of this study was to evaluate and measure the myocardial fibrosis induced by LFN. Two groups of…