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Magnitude of the contralateral efferent olivocochlear effect as a function of the frequency

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Journal of Otology 2022年第2期17卷 67-71页

作者： Fernanda Anza Miranda Enzo Aguilar-Vidal Laboratorio de Audiología y Percepcion Auditiva Facultad de MedicinaUniversidad de ChileChile Escuela de Tecnología Medica Facultad de MedicinaUniversidad de ChileChile departamento de Tecnología Medica Facultad de MedicinaUniversidad de ChileChile

Background:The activation of the medial olivocochlear reflex reduces the cochlear gain,which is manifested perceptually as decreased auditory sensitivity.However,it has remained unclear whether the extent of this suppression varies according to the cochlear region involved.Here we aims to assess the magnitude of contralateral efferent suppression across human cochlea,at low levels,and its impact on hearing sensitivity.Methods:Assuming that acoustic stimulation activates the contralateral medial olivocochlear reflex,we evaluated the magnitude of the suppressive effect as a function of frequency in 17 subjects with normal hearing.Absolute thresholds were measured for bursts tones of various durations(10,100,and 500 ms)and frequencies(250,500,1000,4000,and 8000 Hz)in the presence or absence of contralateral white noise at 60 d B SPL.Results:We found that contralateral noise raised the absolute threshold for the burst tones evaluated.The effect was greater at lower than higher frequencies(3.85 d B at 250 Hz vs.2.22 d B at 8000 Hz).Conclusions:Our findings suggest that in humans,the magnitude of this suppression varies according to the cochlear region stimulated,with a greater effect towards the apex(lower frequencies)than the base(higher frequencies)of the cochlea.

关键词： Auditory perception Efferent system Medial olivocochlear reflex Absolute threshold

The role of peripheral perfusion markers and lactate in septic shock resuscitation

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Journal of Intensive Medicine 2022年第1期2卷 17-21页

作者： Eduardo Kattan Glenn Hernández departamento de medicina Intensiva Facultad de MedicinaPontificia Universidad de ChileSantiago 7500000Chile

Septic shock leads to progressive hypoperfusion and tissue hypoxia.Unfortunately,numerous uncertainties exist around the best monitoring strategy,as available techniques are mere surrogates for these phenomena.Never-theless,central venous oxygen saturation(ScvO 2),venous-to-arterial CO 2 gap,and lactate normalization have been fostered as resuscitation targets for septic shock.Moreover,recent evidence has challenged the central role of lactate.Following the ANDROMEDA-SHOCK trial,capillary refill time(CRT)has become a promissory target,considering the observed benefits in mortality,treatment intensity,and organ dysfunction.Interpretation of CRT within a multimodal approach may aid clinicians in guiding resuscitative interventions and stop resuscitation earlier,thus avoiding the risk of morbid fluid overload.Integrative assessment of a patient’s perfusion status can be easily performed using bedside clinical tools.Based on its fast kinetics and recent supporting evidence,targeting CRT(within a holistic assessment of perfusion)may improve outcomes in septic shock resuscitation.

关键词： Septic shock Lactate Capillary refill time

Alzheimer’s disease risk after COVID-19:a view from the perspective of the infectious hypothesis of neurodegeneration

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Neural Regeneration Research 2023年第7期18卷 1404-1410页

作者： Eugenia Olivera Albany Sáez Lila Carniglia Carla Caruso Mercedes Lasaga Daniela Durand Instituto de Investigaciones Biomédicas INBIOMED UBA-CONICET Facultad de MedicinaUniversidad de Buenos AiresArgentina

In light of the rising evidence of the association between viral and bacterial infections and neurodegeneration,we aimed at revisiting the infectious hypothesis of Alzheimer’s disease and analyzing the possible implications of COVID-19 neurological sequelae in long-term neurodegeneration.We wondered how SARS-CoV-2 could be related to the amyloid-βcascade and how it could lead to the pathological hallmarks of the disease.We also predict a paradigm change in clinical medicine,which now has a great opportunity to conduct prospective surveillance of cognitive sequelae and progression to dementia in people who suffered severe infections together with other risk factors for Alzheimer’s disease.

关键词： Alzheimer amyloid beta antimicrobial cognitive decline COVID-19 infectious hypothesis long-term sequelae neurodegeneration neuroinflammation neurological symptoms neurotropism SARS-CoV-2

Protein synthesis modulation as a therapeutic approach for amyotrophic lateral sclerosis and frontotemporal dementia

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Neural Regeneration Research 2022年第7期17卷 1423-1430页

作者： Santiago E.Charif M.Florencia Vassallu Lara Salvañal Lionel M.Igaz IFIBIO Houssay Grupo de Neurociencia de SistemasFacultad de MedicinaUniversidad de Buenos Aires-CONICETBuenos AiresArgentina

Protein synthesis is essential for cells to perform life metabolic processes.Pathological alterations of protein content can lead to particular diseases.Cells have an intrinsic array of mechanisms and pathways that are activated when protein misfolding,accumulation,aggregation or mislocalization occur.Some of them(like the unfolded protein response)represent complex interactions between endoplasmic reticulum sensors and elongation factors that tend to increase expression of chaperone proteins and/or repress translation in order to restore protein homeostasis(also known as proteostasis).This is even more important in neurons,as they are very susceptible to harmful effects associated with protein overload and proteostatic mechanisms are less effective with age.Several neurodegenerative pathologies such as Alzheimer’s,Parkinson’s,and Huntington’s diseases,amyotrophic lateral sclerosis and frontotemporal dementia exhibit a particular molecular signature of distinct,unbalanced protein overload.In amyotrophic lateral sclerosis and frontotemporal dementia,the majority of cases present intracellular inclusions of ubiquitinated transactive response DNA-binding protein of 43 kDa(TDP-43).TDP-43 is an RNA binding protein that participates in RNA metabolism,among other functions.Dysregulation of TDP-43(e.***.aggregation and mislocalization)can dramatically affect neurons,and this has been linked to disease development.Expression of amyotrophic lateral sclerosis/frontotemporal dementia TDP-43-related mutations in cellular and animal models has been shown to recapitulate key features of the amyotrophic lateral sclerosis/frontotemporal dementia disease spectrum.These variants can be causative of degeneration onset and progression.Most neurodegenerative diseases(including amyotrophic lateral sclerosis and frontotemporal dementia)have no cure at the moment;however,modulating translation has recently emerged as an attractive approach that can be performed at several steps(i.***.regulating activation of initiation and elongation factors

关键词： amyotrophic lateral sclerosis frontotemporal dementia neurodegeneration neurodegenerative diseases protein imbalance protein synthesis modulation proteostasis therapeutical compounds transactive response DNA-binding protein of 43 kDa translation unfolded protein response

Dietary carbohydrate-to-protein ratio influences growth performance,hepatic health and dynamic of gut microbiota in atlantic salmon(Salmo salar)

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Animal Nutrition 2022年第3期10卷 261-279页

作者： Alejandro Villasante Carolina Ramírez Hector Rodríguez Patricio Dantagnan Adrian Hernandez Elías Figueroa Jaime Romero Facultad de Medicina Veterinaria y Agronomía Universidad de Las AmericasSantiagoChile Laboratorio de Biotecnología de Alimentos Unidad de AlimentosInstituto de Nutricion y Tecnología de Los Alimentos(INTA)Universidad de ChileSantiagoChile Programa de Anatomía y Biología del desarrollo Facultad de MedicinaUniversidad de ChileSantiagoChile Núcleo de Investigacion en Produccion Alimentaria Facultad de Recursos NaturalesUniversidad Catolica de TemucoTemucoChile

Atlantic salmon(Salmo salar)fed a carbohydrate-rich diet exhibit suboptimal growth performance,along with other metabolic disturbances.It is well known that gut microbes play a pivotal role in influencing metabolism of the host,and these microbes can be modified by the diet.The main goal of the present study was to determine the effect of feeding graded levels of digestible carbohydrates to Atlantic salmon on the distal intestine digesta microbiota at 3 sampling times(i.e.,weeks 4,8 and 12),during a 12-week trial.A low carbohydrate-to-high protein diet(LC/HP,0%wheat starch),a medium carbohydrate-tomedium protein diet(MC/MP,15%wheat starch)or a high carbohydrate-to-low protein diet(HC/LP,30%wheat starch)was fed to triplicate fish tanks(27 to 28 fish per tank).We performed an in-depth characterization of the distal intestine digesta microbiota.Further,growth parameters,liver histology and the expression of genes involved in hepatic neolipogenesis in fish were measured.Fish fed a HC/LP diet showed greater hepatosomatic and viscerosomatic indexes(P=0.026 and P=0.018,respectively),lower final weight(P=0.005),weight gain(P=0.003),feed efficiency(P=0.033)and growth rate(P=0.003)compared with fish fed the LC/HP diet.Further,feeding salmon a high digestible carbohydrate diet caused greater lipid vacuolization,steatosis index(P=0.007)and expression of fatty acid synthase(fas)and delta-6 fatty acyl desaturase(d6fad)(P=0.001 and P=0.001,respectively)in the liver compared with fish fed the LC/HP diet.Although,the major impact of feeding a carbohydrate-rich diet to Atlantic salmon in beta diversity of distal intestine digesta microbiota was observed at week 4(HC/LP vs MC/MP and HC/LP vs LC/HP;P=0.007 and P=0.008,respectively)and week 8(HC/LP vs MC/MP;P=0.04),no differences between experimental groups were detected after 12 weeks of feeding.Finally,at the end of the trial,there was a negative correlation between lactic acid bacteria(LAB)members,including Leuconostoc and Lactobacillus,with hepatic steatosis level,the hepatosomat

关键词： Microbiota Microbiome Atlantic salmon Steatosis Lactic acid bacteria Probiotics

Noise-induced hippocampal damage:potential mechanisms

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Neural Regeneration Research 2022年第3期17卷 563-564页

作者： Sonia Jazmín Molina Laura Ruth Guelman Universidad de Buenos Aires Consejo Nacional de Investigaciones Científicas y TécnicasCentro de Estudios Farmacológicos y Botánicos(CEFyBOUBA-CONICET)Facultad de MedicinaBuenos AiresArgentina Universidad de Buenos Aires Facultad de Medicina1^(a) Cátedra de FarmacologíaBuenos AiresArgentina

Exposure to noise of high intensities(> 80 dB) is considered a stressful event and might produce both auditory and extra-auditory damage,including different central nervous system(CNS) injuries.Within the CNS,the hippocampus(HC),a structure related to several cognitive functions,has shown to be particularly susceptible to the effects of noise.

关键词： damage auditory injuries

Chronic model of tympanic perforation in rats with mitomycin C and dexamethasone

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Journal of Otology 2019年第1期14卷 12-16页

作者： Tomás Esteban Noemí M.Atucha Jose María Moraleda Joaquín Garcia-Esta? Carmen L.Insausti Javier Moraleda-deleyto Servicio de Otorinolaringologia Hospital General Universitario Santa Lucia departamento de Fisiologia Facultad de Medicina Universidad de Murcia Instituto Murciano de Investigacion Biosanitaria departamento de medicina Facultad de Medicina Universidad de MurciaInstituto Murciano de Investigacion Biosanitaria ENT Service University Hospital of Lewisham

A rat model of chronic tympanic membrane perforation was developed to be used in the search of new materials for the sealing of these perforations. A longitudinal study was carried out in rats subjected to incisional myr-ingotomy followed by the application of mitomycin C alone or with dexamethasone. Rats were checked at days 3, 7,1 0,1 4 and weekly thereafter until perforation closure, for up to 6 months. The addition of dexamethasone is a key component in order to obtain a chronic opening. Myringotomies treated w ith saline had a mean healing time of 8.5 days. At 8 weeks, between 62.5% and 77.7% of tympanic membranes treated w ith mitomycin C and dexamethasone remained perforated and at 6 months this number fell to 21.4%. This technique is able to maintain most tympanic membrane perforations patent for at least 8 weeks. This rat model is adequate for its use in preclinical or translational research.

关键词： Animal model Chronic tympanic membrane perforation Mitomycin C Myringotomy dexamethasone

Effect of full-fat sunflower or flaxseed seeds dietary inclusion on performance,egg yolk fatty acid profile and egg quality in laying hens

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Animal Nutrition 2020年第2期6卷 179-184页

作者： Yandy J.Aguillón-Páez Laura A.Romero Gonzalo J.Diaz facultad de Ciencias Agropecuarias Universidad de CundinamarcaFusagasugá252211Colombia Facultad de Medicina Veterinaria y de Zootecnia Universidad Nacional de ColombiaBogotá111321Colombia

A study was conducted to evaluate the effect of the dietary inclusion of full-fat flaxseed of full-fat sunflower seeds on performance parameters,egg quality parameters and egg yolk fatty acid profile in laying hens.A total of 150 Babcock Brown hens at 27 weeks of age were distributed in 3 experimental treatments,as follows:T1,control;T2,diet containing 13.5% full-fat whole flaxseed seeds;and T3,diet containing 13.5% full-fat ground sunflower seeds.Feed and water were provided ad libitum and the experiment lasted for 8 weeks.No significant differences were found on egg quality parameters,but total egg production and rate of lay were significantly(P ded to determine the level of inclusion of full-fat sunflower seeds that does not affect performance.

关键词： Flaxseed Sunflower Polyunsaturated fatty acid Laying hens Egg quality Performance

Multipotent mesenchymal stromal cells:A promisingstrategy to manage alcoholic liver disease

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World Journal of Gastroenterology 2016年第1期22卷 24-36页

作者： Fernando Ezquer Flavia Bruna Sebastián Calligaris Paulette Conget Marcelo Ezquer Centro de medicina Regenerativa Facultad de MedicinaClínica Alemana-Universidad del DesarrolloSantiago 7710162Chile

Chronic alcohol consumption is a major cause of liver disease.The term alcoholic liver disease(ALD)refers to a spectrum of mild to severe disorders including steatosis,steatohepatitis,cirrhosis,and hepatocellular carcinoma.With limited therapeutic options,stem cell therapy offers significant potential for these patients.In this article,we review the pathophysiologic features of ALD and the therapeutic mechanisms of multipotent mesenchymal stromal cells,also referred to as mesenchymal stem cells(MSCs),based on their potential to differentiate into hepatocytes,their immunomodulatory properties,their potential to promote residual hepatocyte regeneration,and their capacity to inhibit hepatic stellate cells.The perfect match between ALD pathogenesis and MSC therapeutic mechanisms,together with encouraging,available preclinical data,allow us to support the notion that MSC transplantation is a promising therapeutic strategy to manage ALD onset and progression.

关键词： Alcoholic liver disease Cellular therapy Alcoholic steatohepatitis Hepatic function recovery Mesenchymal stem cells