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1.
HNO ; 70(12): 921-930, 2022 Dec.
Artigo em Alemão | MEDLINE | ID: mdl-36239759

RESUMO

Infrasound describes ubiquitous, low-frequency sound (< 20 Hz) in the environment with a long wavelength below the median hearing threshold, which can nevertheless be heard and tactilely perceived, depending on the sound pressure level and frequency spectrum. In nature, infrasound emissions usually occur only in the low-threshold range. Nevertheless, after strong and chronic exposure to usually artificially generated infrasound emissions, various effects on the ear and the body, sometimes questionably critical to health, can be observed. Correct measurement and assessment of infrasound sources is complex and controversial. Established guidelines are scarce. Innovative research areas include infrasound monitoring for evaluation of natural events and infrasound applications in medicine. In the future, it is hoped that new insights will be gained from infrasound research and that a more extensive classification in occupational medicine will be possible.


Assuntos
Audição , Som , Humanos
2.
HNO ; 68(6): 461-472, 2020 Jun.
Artigo em Alemão | MEDLINE | ID: mdl-32377780

RESUMO

Unilateral vocal fold palsy is a frequent cause of hoarseness. In the presence of glottis closure insufficiency, the effectiveness of conservative voice therapy is often limited and phonosurgery may be indicated. Injection laryngoplasty is effective for correction of insufficiency. Early intervention during the first 6 months after diagnosis is desired to avoid subsequent insufficient endogenous compensation. Particularly patients with glottic closure insufficiency ≤2 mm in stroboscopy may benefit from this procedure. With appropriate patient selection, duration of the effect exceeding 12 months has been described for hyaluronic acid, calcium hydroxylapatite, and autologous fat. Due to rare complications such as allergic swelling at the injection site, regular laryngoscopic monitoring and observation for two nights after injection are recommended. The voice must only be rested for a few hours.


Assuntos
Laringoplastia , Paralisia das Pregas Vocais , Humanos , Injeções , Estroboscopia , Resultado do Tratamento , Paralisia das Pregas Vocais/cirurgia , Prega Vocal/cirurgia
3.
Age Ageing ; 48(5): 719-724, 2019 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-31112221

RESUMO

INTRODUCTION: we examined the consequences of applying the new EWGSOP2 algorithm for sarcopenia screening instead of the former EWGSOP algorithm (EWGSOP1) in geriatric inpatients. METHODS: the dataset of our formerly published Sarcopenia in Geriatric Elderly (SAGE) study includes 144 geriatric inpatients (86 women, 58 men, mean age 80.7±5.6 years) with measurements of gait speed, handgrip strength and appendicular muscle mass by dual x-ray absorptiometry (DXA). We analysed the agreement between EWGSOP and EWGSOP2 algorithms in identifying patients as sarcopenic/non-sarcopenic. Differences in the distribution sarcopenic vs. non-sarcopenic were assessed by Chi²-test. RESULTS: sarcopenia prevalence according to EWGSOP1 (41 (27.7%)) was significantly higher than with EWGSOP2 (26(18.1%), p<0.05). The sex-specific sarcopenia prevalence was 22.1% (EWGSOP1) and 17.4% (EWGSOP2), respectively, for women (difference not significant) and 37.9% vs. 19.4% for men (p<0.05%). The overall agreement in classifying subjects as sarcopenic/non-sarcopenic was 81.25% (81.4% for women, 81.0% for men). However, among the 41 sarcopenia cases identified by EWGSOP1, only 20 (48.8%) were diagnosed with sarcopenia by EWGSOP2 (9/19 w (47.4%), 11/22 m (50.0%)). Ten of 19 women (52.6%) and 11 of 22 men (50.0%) diagnosed with sarcopenia by EWGSOP1 were missed by EWGSOP2, while 6 of 15 women (40.0%) and 0 of 11 men (0.0%) were newly diagnosed. DISCUSSION: there is a substantial mismatch in sarcopenia case finding according to EWGSOP1 and EWGSOP2. The overall prevalence and the number of men diagnosed with sarcopenia are significantly lower in EWGSOP2. While the absolute number of women identified as sarcopenic remains relatively constant, the overlap of individual cases between the two definitions is low.


Assuntos
Algoritmos , Marcha/fisiologia , Avaliação Geriátrica/métodos , Força da Mão/fisiologia , Pacientes Internados , Guias de Prática Clínica como Assunto , Sarcopenia/diagnóstico , Absorciometria de Fóton , Idoso , Idoso de 80 Anos ou mais , Áustria/epidemiologia , Diagnóstico Diferencial , Feminino , Humanos , Incidência , Masculino , Prevalência , Estudos Retrospectivos , Sarcopenia/epidemiologia , Sarcopenia/fisiopatologia
4.
HNO ; 67(10): 801-814, 2019 Oct.
Artigo em Alemão | MEDLINE | ID: mdl-31485696

RESUMO

Dysphagia is a common symptom and can be indicative of a variety of heterogeneous diseases. "Classical" diseases of the head and neck region, such as acute tonsillitis, peritonsillar abscesses, diverticula, and benign or malignant tumors are common causes of dysphagia. However, it can also occur in the context of neurological diseases, e.g., as a result of stroke or as an age-related phenomenon (presbyphagia). Pathologies of the cervical spine can also be a cause of dysphagia. In this context, congenital or acquired diseases, inflammatory or degenerative processes, cervical spine surgery, and (malignant) masses of the cervical spine should be taken into account. Particular dysphagia with a positive history of previous operative interventions on the cervical spine or symptoms such as chronic back pain and trauma should give rise to consideration of a cervical spine-related cause.


Assuntos
Transtornos de Deglutição , Doenças da Coluna Vertebral , Vértebras Cervicais , Transtornos de Deglutição/diagnóstico , Transtornos de Deglutição/etiologia , Cabeça , Humanos , Pescoço , Doenças da Coluna Vertebral/complicações , Doenças da Coluna Vertebral/diagnóstico
5.
Z Gerontol Geriatr ; 52(7): 688-693, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31049683

RESUMO

BACKGROUND: Sarcopenia and osteoporosis share an underlying pathology and reinforce each other in terms of negative outcomes. OBJECTIVE: To evaluate the extent of concomitance of sarcopenia as defined by the European Working Group on Sarcopenia in Older People (EWGSOP) and osteoporosis as defined by the World Health Organization (WHO) in geriatric inpatients and their relationship to nutritional and functional status. MATERIAL AND METHODS: A cross-sectional analysis of geriatric inpatients from the sarcopenia in geriatric elderly (SAGE) study. Measurements included dual X­ray absorptiometry for bone mineral density and appendicular muscle mass; gait speed and hand grip strength, the Barthel index, body mass index (BMI) and the mini nutritional assessment short form (MNA-SF). RESULTS: Of the 148 patients recruited for SAGE, 141 (84 women, 57 men; mean age 80.6 ± 5.5 years) had sufficient data to be included in this ancillary investigation: 22/141 (15.6%) were only osteoporotic, 19/141 (13.5%) were only sarcopenic and 20/141 (14.2%) osteosarcopenic (i.e. both sarcopenia and osteoporosis). The prevalence of osteoporosis was higher in sarcopenic than in non-sarcopenic individuals (51.3% vs. 21.6%, p < 0.001). Sarcopenic, osteoporotic and osteosarcopenic subjects had a lower BMI, MNA-SF, handgrip and gait speed (p < 0.05) than the reference group (those neither osteoporotic nor sarcopenic, n = 80). The Barthel index was lower for sarcopenic and osteosarcopenic (p < 0.05) but not for osteoporotic (p = 0.07) subjects. The BMI and MNA-SF were lower in osteosarcopenia compared to sarcopenia or osteoporosis alone (p < 0.05) while there were no differences in functional criteria. CONCLUSION: Osteoporosis and sarcopenia are linked to nutritional deficits and reduced function in geriatric inpatients. Co-occurrence (osteosarcopenia) is common and associated with a higher degree of malnutrition than osteoporosis or sarcopenia alone.


Assuntos
Osteoporose , Sarcopenia , Idoso , Idoso de 80 Anos ou mais , Estudos Transversais , Feminino , Marcha , Força da Mão , Humanos , Masculino , Osteoporose/complicações , Osteoporose/epidemiologia , Prevalência , Sarcopenia/complicações , Sarcopenia/epidemiologia
6.
Cytokine ; 108: 53-56, 2018 08.
Artigo em Inglês | MEDLINE | ID: mdl-29571040

RESUMO

OBJECTIVE: Oxidative stress is involved in several maternal conditions characterized both by an increase in free radicals synthesis and a parallel decrease in the antioxidant activity. Parturition induces considerable oxidative stress and many inflammatory mediators, among which HMGB1, are involved from the beginning of pregnancy to the birth of the infant. We evaluated serum cord blood HMGB1 levels in a population of neonates to investigate correlation with mode of delivery, as well as the influence of labour. SETTING AND PATIENTS: The study subjects were 325 neonates delivered at University Hospital "G. Martino" of Messina over an 18-month period. Following cord separation, venous blood sampling was performed on umbelical cords. RESULTS: In the cord venous blood, we found HMGB1 values significantly more elevated in spontaneous vaginal group when compared to elective or emergency caesarean section group. Regarding labour, umbilical cord venous blood HMGB1 levels were significantly higher in the spontaneous and induced labour group, compared to non-labouring women. CONCLUSION: These results could highlight a possible role of HMGB1 during birth time related to mode of delivery and labour.


Assuntos
Sangue Fetal/química , Proteína HMGB1/sangue , Trabalho de Parto , Adulto , Cesárea , Parto Obstétrico , Feminino , Humanos , Recém-Nascido , Estresse Oxidativo , Parto , Projetos Piloto , Gravidez
7.
Langmuir ; 34(13): 3909-3917, 2018 04 03.
Artigo em Inglês | MEDLINE | ID: mdl-29513999

RESUMO

We have investigated the morphologies of Langmuir layers of charged, polymeric hard-core/interlayer/soft-shell nanoparticles spread at the air-water interface. Depending on various mutual interactions, which are correlated to the areal densities of the deposited nanoparticles, we observed ordered patterns of nondense and closed-packed arrangements of core/interlayer/shell (CIS) nanoparticle ordering. At low areal densities, we found an almost regular distribution of the charged CIS nanoparticles on the water surface, which resulted from long-range repulsive electrostatic interactions between them. At higher areal densities, domains of more closely packed and ordered nanoparticles were formed, coexisting with regions of randomly and sparsely distributed nanoparticles. We relate these domains to the interplay of electrostatic repulsion and capillary attraction caused by the dipolar character of like-charged particles at the interface, allowing for a characteristic separation distance between nanoparticles of about 3-4 times the nanoparticle diameter. At relatively high areal densities, attractive van der Waals forces were finally capable of making nanoparticles to come in contact with each other, leading to densely packed patches of hexagonally ordered nanoparticles coexisting with regions of rather well-ordered nanoparticles separated by about 1 µm and regions of randomly and sparsely distributed nanoparticles. Intriguingly, upon re-expansion of the area available per nanoparticle, these densely packed patches disappeared, indicating that steric repulsion due to the presence of soft shells as well as long-range electrostatic repulsive forces were strong enough to assure reversibility of the morphological behavior.

8.
HNO ; 66(8): 598-604, 2018 Aug.
Artigo em Alemão | MEDLINE | ID: mdl-29947857

RESUMO

BACKGROUND: A submucous cleft palate and a congenitally short velum are diagnosed rather late, because symptoms are often mild. OBJECTIVES: The pre- and postoperative clinical symptoms for both conditions are presented. MATERIALS AND METHODS: The data of 180 patients with a submucous cleft palate (161) or congenitally short velum (19) were retrospective analyzed. In 23.3%, a syndromic association was found. RESULTS: Clinical findings for both conditions included middle ear problems, hypernasal speech, nasal penetration, the absence of the posterior nasal spine of the hard palate and/or a bifid uvula with a zona pellucida. The average age at diagnosis was 4.2 years in submucous clefts and 5.7 years in children with a congenitally short velum. Surgical palatoplasty with fusion of soft palate muscles and/or elongation of the soft palate was performed in 83.9% of the children, aiming to achieve sufficient velopharyngeal closure (VPC) with a significant decrease of symptoms and, hence, better conditions for speech therapy interventions. The overall success rate of the VPC was 63.7% with improvement in up to 2 of the 3 clinical symptoms (hypernasal speech, nasal penetration, middle ear problems). Hypernasal speech was more common (in 89.5%) in children with a congenitally short velum before surgery and in 81.3% 8 weeks after surgery; however, prior to surgery they had a short soft palate. CONCLUSION: Surgical intervention was particularly effective in children younger than 5 years. Syndromic diseases are disproportionately associated with soft palate defects.


Assuntos
Fissura Palatina , Insuficiência Velofaríngea , Criança , Pré-Escolar , Fissura Palatina/complicações , Fissura Palatina/cirurgia , Humanos , Palato Duro , Palato Mole , Estudos Retrospectivos , Resultado do Tratamento , Insuficiência Velofaríngea/cirurgia
9.
Laryngorhinootologie ; 95(10): 694-701, 2016 Oct.
Artigo em Alemão | MEDLINE | ID: mdl-27043186

RESUMO

Introduction: In order for a diagnosis of Occupational Hearing Loss (BK-no. 2301) to be made certain criteria must be fulfilled to establish that the hearing loss is occupational in origin. This work compares 2 groups, those who fulfil the criteria (BKE) and those who do not (BKNE). Methods: A 100 consecutive reports ("Lärmgutachten BK-no. 2301") written by the authors were examined retrospectively. These recorded audiometric examination, an analysis of any tinnitus and noise exposure plus use of hearing protection. Pre- and post-noise exposure status together with an expert assessment of work limitations was made to produce a 7 point score. Results: 67% of the group fulfilled the conditions for occupational hearing loss (9% were entitled to compensation). In the BKE group 82% showed typical audiometric signs of noise damage with 75% of them fulfilling at least 6 criteria of occupational disease no. 2301. Tinnitus typical for noise exposure was found in 26%. Discussion: A 7 point score could be useful in the future as a method of helping distinguish hearing loss and tinnitus from occupational as opposed to other causes.


Assuntos
Prova Pericial/legislação & jurisprudência , Perda Auditiva Provocada por Ruído/diagnóstico , Doenças Profissionais/diagnóstico , Indenização aos Trabalhadores/legislação & jurisprudência , Adulto , Idoso , Idoso de 80 Anos ou mais , Audiometria de Tons Puros , Audiometria da Fala , Avaliação da Deficiência , Dispositivos de Proteção das Orelhas , Feminino , Alemanha , Perda Auditiva Provocada por Ruído/prevenção & controle , Humanos , Masculino , Pessoa de Meia-Idade , Doenças Profissionais/prevenção & controle , Emissões Otoacústicas Espontâneas , Estudos Retrospectivos , Zumbido/diagnóstico , Zumbido/prevenção & controle
11.
J Pineal Res ; 58(4): 490-9, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25807895

RESUMO

This study investigated the maturational stage (immature and mature ovaries) differences of mRNA expression of melatonin-forming enzymes (Aanat and Asmt), melatonin membrane receptors (Mt1 and Mt2) and putative nuclear (Rorα) receptors, and clock genes (Clock, Bmal1, Per1, Per2, Cry1, Cry2) in cumulus-oocyte complexes (COC) from weaning Wistar rats. We also examined the effects of pinealectomy and of melatonin pharmacological replacement on the daily expression of these genes in COC. qRT-PCR analysis revealed that in oocytes, the mRNA expression of Asmt, Mt2, Clock, Bmal1, Per2, and Cry1 were higher (P < 0.05) in immature ovaries than in the mature ones. In cumulus cells, the same pattern of mRNA expression for Asmt, Aanat, Rorα, Clock, Per1, Cry1, and Cry2 genes was observed. In oocytes, pinealectomy altered the daily mRNA expression profiles of Asmt, Mt1, Mt2, Clock, Per1, Cry1, and Cry2 genes. In cumulus cells, removal of the pineal altered the mRNA expression profiles of Mt1, Mt2, Rorα, Aanat, Asmt, Clock, Bmal1, Per2, Cry1, and Cry2 genes. Melatonin treatment partially or completely re-established the daily mRNA expression profiles of most genes studied. The mRNA expression of melatonin-related genes and clock genes in rat COC varies with the maturational stage of the meiotic cellular cycle in addition to the hour of the day. This suggests that melatonin might act differentially in accordance with the maturational stage of cumulus/oocyte complex. In addition, it seems that circulating pineal melatonin is very important in the design of the daily profile of mRNA expression of COC clock genes and genes related to melatonin synthesis and action.


Assuntos
Células do Cúmulo/metabolismo , Melatonina/metabolismo , Oócitos/metabolismo , Glândula Pineal/cirurgia , Animais , Arilalquilamina N-Acetiltransferase/metabolismo , Ritmo Circadiano/fisiologia , Feminino , Proteínas Circadianas Period/metabolismo , Ratos , Ratos Wistar , Receptores de Melatonina/metabolismo
12.
J Periodontal Res ; 50(1): 9-17, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24665831

RESUMO

BACKGROUND AND OBJECTIVES: The purpose of this article was to summarize what is known about the function of melatonin in the oral cavity. MATERIAL AND METHODS: Databases were searched for the relevant published literature to 30 November, 2013. The following search items were used in various combinations: melatonin, gingiva, periodontium, inflammation, herpes, alveolar bone, periodontal ligament, dental implants, xerostomia, methacrylate, chlorhexidine, cancer. The literature uncovered is summarized herein. RESULTS: Salivary melatonin levels exhibit a circadian rhythm with highest values at night. Melatonin has both receptor-mediated and receptor-independent actions in cells of the oral cavity. Melatonin is released into the saliva by the acinar cells of the major salivary glands and via the gingival fluid. Functions of melatonin in the oral cavity are likely to relate primarily to its anti-inflammatory and antioxidant activities. These actions may suppress inflammation of the gingiva and periodontium, reduce alveolar bone loss, abrogate herpes lesions, enhance osteointegration of dental implants, limit oral cancer, and suppress disorders that have a free radical component. Sublingual melatonin tablets or oral melatonin sprays and topical melatonin-containing gel, if used on a regular basis, may improve overall oral health and reduce mucosal lesions. CONCLUSION: Collectively, the results indicate that endogenously-produced and exogenously-applied melatonin are beneficial to the oral cavity.


Assuntos
Melatonina/fisiologia , Doenças da Boca/fisiopatologia , Boca/fisiologia , Periodonto/fisiologia , Anti-Inflamatórios/farmacologia , Antioxidantes/farmacologia , Ritmo Circadiano/fisiologia , Sequestradores de Radicais Livres/farmacologia , Humanos , Melatonina/análise , Saliva/química
13.
J Biol Regul Homeost Agents ; 29(2 Suppl 1): 142-9, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26634600

RESUMO

Atopic dermatitis (AD) is a chronic relapsing-remitting inflammatory skin disorder, characterized by a skin barrier dysfunction resulting in epidermal damage and altered permeability to allergens and microbes. Traditionally, the immunological mechanism involving the Th1-Th2 paradigm is considered central in the pathogenesis of AD. However, oxidative stress is, currently, recognized as a fundamental predisposing stimulus for AD. Several therapeutic approaches have been proposed as treatment, including the use of melatonin. This indolamine, through widespread expression and pleiotropic activity of the cutaneous melatoninergic system, may counteract environmental and endogenous stressors, regulate the immune response, decrease oxidative stress, and, finally, promote skin integrity. In the light of its pleiotropic effects, melatonin could represent a potential and alternative therapeutic approach in patients with AD.

15.
Laryngorhinootologie ; 94(3): 189-95; quiz 196-8, 2015 Mar.
Artigo em Alemão | MEDLINE | ID: mdl-25751774

RESUMO

Rheumatic disorders (rheumatoid arthritis, sarcoidosis, systemic lupus erythematosus, Wegener's granulomatosis, relapsing polychondritis) may affect the larynx. The clinical symptoms are often unspecific, leading to delayed diagnosis. Malignant tumours should be considered in differential diagnosis with necessitating biopsy. Treatment may require interdisciplinary approach together with a specialist in internal medicine and rheumatology.


Assuntos
Doenças da Laringe/diagnóstico , Doenças Reumáticas/diagnóstico , Comportamento Cooperativo , Diagnóstico Diferencial , Humanos , Comunicação Interdisciplinar , Doenças da Laringe/terapia , Doenças Reumáticas/terapia , Distúrbios da Voz/diagnóstico
16.
Laryngorhinootologie ; 94(9): 579-86, 2015 Sep.
Artigo em Alemão | MEDLINE | ID: mdl-25429643

RESUMO

BACKGROUND: By considering their general development, 2-year-old children with delayed speech development (late -talkers, LT) were examined and described with respect to linguistic competence and hearing. METHODS: Initially, 50 monolingual German speaking LT (age: 23-28 months) were recruited. In addition to audiological tests (impedance testing, otoacoustic emissions, reaction audiometry), language development status test was performed (clinical impression during examination, expressive vocabulary: FRAKIS, receptive competence: SETK-2). RESULTS: After exclusion of 10 children with general retarded development (3 premature infants, 2 children with suspicion of autism and 2 children with infantile brain damage) 33 LTs with normal hearing were included. The expressive vocabulary (FRAKIS) of 82% of these 33 LTs were below the normal range. 39% showed deficits in language comprehension tests (SETK-2) although parental reports mentioned language comprehension problems in only 3 LT. No correlation was found between vocabulary (FRAKIS) and language comprehension (SETK-2). CONCLUSION: The clinical collective in this study showed severely affected children with a high percentage of other abnormalities and speech perception problems in many cases. Despite normal hearing, vocabulary and especially speech comprehension should also be tested. LT with language comprehension problems require early developmental psychological investigation in order to prevent language and general developmental limitations. Only in this way, remedial instruction adapted to the develop-mental level can be initiated.


Assuntos
Transtornos da Audição/complicações , Transtornos da Audição/diagnóstico , Testes Auditivos , Transtornos do Desenvolvimento da Linguagem/diagnóstico , Transtornos do Desenvolvimento da Linguagem/etiologia , Testes de Linguagem , Transtornos da Percepção Auditiva/diagnóstico , Transtornos da Percepção Auditiva/etiologia , Pré-Escolar , Comportamento Cooperativo , Feminino , Humanos , Lactente , Deficiência Intelectual/diagnóstico , Deficiência Intelectual/etiologia , Comunicação Interdisciplinar , Masculino , Estudos Prospectivos , Percepção da Fala , Vocabulário
17.
Laryngorhinootologie ; 94(2): 91-6, 2015 Feb.
Artigo em Alemão | MEDLINE | ID: mdl-24676872

RESUMO

Vocal cord paralysis has diverse etiologies. In the present study, vocal chord paralysis caused by surgery/trauma was present in more than two thirds of the cases, followed by primary malignancy-associated paralysis. Thyroidectomy was the most common cause in bilateral paresis, especially if performed in recurrent or malignant disease. Voice therapy was promising in pa-tients with unilateral paresis and hoarseness as main symptom. Persistent dysphonia due to insufficiency of the glottic closure led to an operative glottis restricting procedure in only 6% of cases. In almost half the patients with dyspnea as the main symp-tom of bilateral vocal cord paresis, temporary tracheotomy or surgical glottis widening procedures had to be performed. The group of idiopathic and traumatic paresis patients showed the best spontaneous recovery within the first 12 months in comparison to primary malignancy-associated paralysis, which showed no recovery of the recurrens nerve.


Assuntos
Paralisia das Pregas Vocais/etiologia , Adulto , Idoso , Disfonia/etiologia , Disfonia/terapia , Dispneia/etiologia , Dispneia/terapia , Feminino , Seguimentos , Rouquidão/etiologia , Rouquidão/terapia , Humanos , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias/etiologia , Prognóstico , Traumatismos do Nervo Laríngeo Recorrente/complicações , Traumatismos do Nervo Laríngeo Recorrente/etiologia , Traumatismos do Nervo Laríngeo Recorrente/terapia , Fatores de Risco , Tireoidectomia/efeitos adversos , Traqueotomia , Paralisia das Pregas Vocais/diagnóstico , Paralisia das Pregas Vocais/terapia , Treinamento da Voz
18.
Br J Dermatol ; 170(2): 382-91, 2014 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-24024734

RESUMO

BACKGROUND: Sun exposure is responsible for long-term clinical skin changes such as photoageing, photodamage and photocancers. Ultraviolet (UV)A wavelengths stimulate the production of reactive oxygen species (ROS) that may contribute to photoageing. To protect against oxidative stress, skin cells have developed several defence systems, including ROS and metal ion scavengers and a battery of detoxifying, haem-degrading and repair enzymes. Melatonin's antioxidant activity is the result of three different but complementary actions: (i) a direct action due to its ability to act as a free radical scavenger; (ii) an indirect action that is a consequence of melatonin's ability to reduce free radical generation (radical avoidance); and (iii) its ability to upregulate antioxidant enzymes. OBJECTIVES: In this study, we focused our attention on the prevention of photodamage, choosing melatonin as an antioxidant agent. METHODS: In the present study we analysed the effects of pretreatment of murine fibroblasts cells (NIH3T3) with melatonin (1 mmol L(-1) ) followed by UVA irradiation (15 J cm(-2) ). Thereafter, changes in components of the extracellular matrix and in some antioxidant enzymes (inducible and constitutive haem oxygenase) were evaluated. RESULTS: We observed that UVA radiation caused altered expression of extracellular matrix proteins and induced the expression of inducible haem oxygenase. This increase was not sufficient to protect the cells from damage. Instead, melatonin pretreatment led to increased expression of haem-degrading enzymes and suppression of UVA-induced photodamage. CONCLUSIONS: These results suggest that melatonin, as a modifier of the dermatoendocrine system, may have utility in reducing the effects of skin ageing.


Assuntos
Antioxidantes/farmacologia , Fibroblastos/efeitos da radiação , Melatonina/farmacologia , Raios Ultravioleta/efeitos adversos , Animais , Caspase 3/metabolismo , Colágeno Tipo I/metabolismo , Colágeno Tipo II/metabolismo , Citocromos c/metabolismo , Fibroblastos/metabolismo , Fibronectinas/metabolismo , Imunofluorescência , Heme Oxigenase-1/metabolismo , Camundongos , Células NIH 3T3 , Pele/citologia , Pele/metabolismo , Pele/efeitos da radiação , Fator de Crescimento Transformador beta1/metabolismo
19.
J Pineal Res ; 56(4): 371-81, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24654916

RESUMO

Melatonin is an old and ubiquitous molecule in nature showing multiple mechanisms of action and functions in practically every living organism. In mammals, pineal melatonin functions as a hormone and a chronobiotic, playing a major role in the regulation of the circadian temporal internal order. The anti-obesogen and the weight-reducing effects of melatonin depend on several mechanisms and actions. Experimental evidence demonstrates that melatonin is necessary for the proper synthesis, secretion, and action of insulin. Melatonin acts by regulating GLUT4 expression and/or triggering, via its G-protein-coupled membrane receptors, the phosphorylation of the insulin receptor and its intracellular substrates mobilizing the insulin-signaling pathway. Melatonin is a powerful chronobiotic being responsible, in part, by the daily distribution of metabolic processes so that the activity/feeding phase of the day is associated with high insulin sensitivity, and the rest/fasting is synchronized to the insulin-resistant metabolic phase of the day. Furthermore, melatonin is responsible for the establishment of an adequate energy balance mainly by regulating energy flow to and from the stores and directly regulating the energy expenditure through the activation of brown adipose tissue and participating in the browning process of white adipose tissue. The reduction in melatonin production, as during aging, shift-work or illuminated environments during the night, induces insulin resistance, glucose intolerance, sleep disturbance, and metabolic circadian disorganization characterizing a state of chronodisruption leading to obesity. The available evidence supports the suggestion that melatonin replacement therapy might contribute to restore a more healthy state of the organism.


Assuntos
Tecido Adiposo Marrom/metabolismo , Metabolismo Energético , Melatonina/metabolismo , Obesidade/metabolismo , Tecido Adiposo Marrom/patologia , Animais , Regulação da Expressão Gênica , Transportador de Glucose Tipo 4/biossíntese , Humanos , Melatonina/uso terapêutico , Obesidade/tratamento farmacológico , Obesidade/patologia
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