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1.
Phys Rev Lett ; 133(9): 092301, 2024 Aug 30.
Artículo en Inglés | MEDLINE | ID: mdl-39270180

RESUMEN

This Letter presents the most precise measurement to date of the matter-antimatter imbalance at midrapidity in Pb-Pb collisions at a center-of-mass energy per nucleon pair sqrt[s_{NN}]=5.02 TeV. Using the Statistical Hadronization framework, it is possible to obtain the value of the electric charge and baryon chemical potentials, µ_{Q}=-0.18±0.90 MeV and µ_{B}=0.71±0.45 MeV, with unprecedented precision. A centrality-differential study of the antiparticle-to-particle yield ratios of charged pions, protons, Ω baryons, and light (hyper)nuclei is performed. These results indicate that the system created in Pb-Pb collisions at the LHC is on average baryon-free and electrically neutral at midrapidity.

2.
Phys Rev Lett ; 133(2): 022301, 2024 Jul 12.
Artículo en Inglés | MEDLINE | ID: mdl-39073970

RESUMEN

The ALICE Collaboration reports the measurement of semi-inclusive distributions of charged-particle jets recoiling from a high transverse momentum (high p_{T}) hadron trigger in proton-proton and central Pb-Pb collisions at sqrt[s_{NN}]=5.02 TeV. A data-driven statistical method is used to mitigate the large uncorrelated background in central Pb-Pb collisions. Recoil jet distributions are reported for jet resolution parameter R=0.2, 0.4, and 0.5 in the range 7

3.
Phys Rev Lett ; 132(17): 172302, 2024 Apr 26.
Artículo en Inglés | MEDLINE | ID: mdl-38728735

RESUMEN

This Letter presents the measurement of near-side associated per-trigger yields, denoted ridge yields, from the analysis of angular correlations of charged hadrons in proton-proton collisions at sqrt[s]=13 TeV. Long-range ridge yields are extracted for pairs of charged particles with a pseudorapidity difference of 1.4<|Δη|<1.8 and a transverse momentum of 1

4.
Phys Rev Lett ; 132(16): 162302, 2024 Apr 19.
Artículo en Inglés | MEDLINE | ID: mdl-38701458

RESUMEN

The first measurement of the cross section for incoherent photonuclear production of J/ψ vector mesons as a function of the Mandelstam |t| variable is presented. The measurement was carried out with the ALICE detector at midrapidity, |y|<0.8, using ultraperipheral collisions of Pb nuclei at a center-of-mass energy per nucleon pair of sqrt[s_{NN}]=5.02 TeV. This rapidity interval corresponds to a Bjorken-x range (0.3-1.4)×10^{-3}. Cross sections are given in five |t| intervals in the range 0.04<|t|<1 GeV^{2} and compared to the predictions by different models. Models that ignore quantum fluctuations of the gluon density in the colliding hadron predict a |t| dependence of the cross section much steeper than in data. The inclusion of such fluctuations in the same models provides a better description of the data.

5.
Phys Rev Lett ; 132(22): 222303, 2024 May 31.
Artículo en Inglés | MEDLINE | ID: mdl-38877919

RESUMEN

K^{+}K^{-} pairs may be produced in photonuclear collisions, either from the decays of photoproduced ϕ(1020) mesons or directly as nonresonant K^{+}K^{-} pairs. Measurements of K^{+}K^{-} photoproduction probe the couplings between the ϕ(1020) and charged kaons with photons and nuclear targets. The kaon-proton scattering occurs at energies far above those available elsewhere. We present the first measurement of coherent photoproduction of K^{+}K^{-} pairs on lead ions in ultraperipheral collisions using the ALICE detector, including the first investigation of direct K^{+}K^{-} production. There is significant K^{+}K^{-} production at low transverse momentum, consistent with coherent photoproduction on lead targets. In the mass range 1.1

6.
Khirurgiia (Mosk) ; (3): 54-62, 2024.
Artículo en Ruso | MEDLINE | ID: mdl-38477244

RESUMEN

OBJECTIVE: To determine if laparoscopic excision is more effective than open excision in the treatment of choledochal cysts. MATERIAL AND METHODS: A systematic review of randomized clinical trials in 3 databases measuring the efficacy of laparoscopic and open excision of choledochal cysts was performed. The authors considered international and national reports, whose results were analyzed in detail. RESULTS: Mean duration of laparoscopic excision was 51 min, open excision - 35.4 min. Length of hospital-stay after laparoscopic excision ranged between 5 and 74 days, after open excision - between 7 and 146 days. Bile leakage rate was 1-2% and 4%, respectively. Laparoscopic excision was followed by lower complication rate. Morbidity and mortality in laparoscopic excision was 20% and 0%, in open excision - 60% and 3.3%, respectively. CONCLUSION: Laparoscopic excision is more effective than open excision in the treatment of choledochal cysts.


Asunto(s)
Quiste del Colédoco , Laparoscopía , Complicaciones Posoperatorias , Humanos , Quiste del Colédoco/cirugía , Laparoscopía/métodos , Laparoscopía/efectos adversos , Complicaciones Posoperatorias/etiología , Complicaciones Posoperatorias/prevención & control , Complicaciones Posoperatorias/epidemiología , Tiempo de Internación/estadística & datos numéricos , Resultado del Tratamiento , Evaluación de Procesos y Resultados en Atención de Salud
7.
Khirurgiia (Mosk) ; (7): 73-77, 2024.
Artículo en Ruso | MEDLINE | ID: mdl-39008699

RESUMEN

OBJECTIVE: To determine the relationship between appendectomy and cognitive impairment in adults aged 50-70 years. MATERIAL AND METHODS: A case-control study was carried out with 270 patients between May and July 2023. Ninety cases (with cognitive impairment) and 180 controls (without impairment), diagnosed by the Montreal Cognitive Assessment (MoCA), were assessed. RESULTS: 31.11% of the total cases with cognitive impairment were submitted to an appendectomy, with an average of 25 years since surgery. Regarding other surgeries: 40% with impairment underwent cholecystectomy and 23.33% reported other operations. The analysis revealed significant differences in age, body mass index, hypertension, diabetes and smoking between the groups. However, there was no significant difference by gender. Logistic regression analysis highlighted that age and past appendectomy were strongly associated with cognitive impairment, with an Odds Ratio (OR) of 1.20 and 12.91, respectively. Associations were also found with cholecystectomy (OR 7.33), other surgeries (OR 13.39) and smoking (OR 6.91). CONCLUSION: Appendectomy might be a significant risk factor for cognitive impairment in adults aged 50-70 years.


Asunto(s)
Apendicectomía , Disfunción Cognitiva , Humanos , Apendicectomía/métodos , Apendicectomía/efectos adversos , Masculino , Femenino , Persona de Mediana Edad , Disfunción Cognitiva/etiología , Disfunción Cognitiva/epidemiología , Disfunción Cognitiva/diagnóstico , Anciano , Estudios de Casos y Controles , Factores de Riesgo , Colecistectomía/métodos , Colecistectomía/efectos adversos
8.
Khirurgiia (Mosk) ; (8): 15-20, 2024.
Artículo en Ruso | MEDLINE | ID: mdl-39140938

RESUMEN

OBJECTIVE: To identify the factors associated with normal leukocyte count and C-reactive protein (CRP) in adults with acute appendicitis. MATERIAL AND METHODS: A retrospective cohort study included patients aged 18-60 years after surgeries for acute appendicitis. Convenience sampling was used to select medical records, and variables such as age, sex, weight, height, origin, self-medication, diabetes (DM2), high blood pressure (HBP), type of appendicitis, duration of illness, preoperative time, type of appendectomy, operative time, and hospital stay were analyzed. Patients were categorized into those with normal and abnormal inflammatory parameters. The SPSS version 28 software was used for analysis. RESULTS: We included 333 patients; 11.11% ones had normal inflammatory parameters. Both groups had mean age of approximately 33 years. Men comprised 56.76% and 57.43%in both groups, respectively. The abnormal group had shorter mean preoperative time, and catarrhal appendicitis was more common in the normal group. Multivariate analysis revealed that rural origin and self-medication were significantly associated with normal inflammatory parameters. CONCLUSION: The prevalence of normal inflammatory parameters in acute appendicitis patients was 11.11%. Rural origin, self-medication, shorter preoperative time, and catarrhal appendicitis were significantly associated with normal inflammatory parameters in this context.


Asunto(s)
Apendicectomía , Apendicitis , Proteína C-Reactiva , Humanos , Apendicitis/cirugía , Apendicitis/sangre , Apendicitis/diagnóstico , Adulto , Masculino , Femenino , Proteína C-Reactiva/análisis , Recuento de Leucocitos/métodos , Estudios Retrospectivos , Apendicectomía/métodos , Persona de Mediana Edad , Enfermedad Aguda , Adolescente , Adulto Joven
9.
Khirurgiia (Mosk) ; (6): 51-57, 2024.
Artículo en Ruso | MEDLINE | ID: mdl-38888019

RESUMEN

INTRODUCTION: Inguinal hernia is defined as a projection of an organ through the inguinal canal. This can be incarcerated as a consequence of continuous inflammation of the hernial sac, which will prevent its return, causing damage to the venous and lymphatic return of the viscera. The neutrophil-to-lymphocyte ratio (NLR) is an easily accessible inflammatory biomarker obtained from blood cell counts. Therefore, the objective was to determine if the NLR is useful as a predictor of intestinal resection in incarcerated inguinal hernias. MATERIAL AND METHOD: An observational, analytical, diagnostic test and retrospective study was carried out in a hospital in northern Peru from January 2013 to August 2019 in the Department of General Surgery and Emergency Surgery and Critical Care. Patients diagnosed with unilateral inguinal hernia with intestinal obstruction were included. For the relationship between the event and the exposure, it was analyzed using Chi square (χ2) and T-Student. The sensitivity, specificity, positive predictive value, negative predictive value of the NLR as well as the area under the ROC curve were found to determine the predictive accuracy. RESULTS: 161 patients with incarcerated inguinal hernia were studied: group I (20 patients with intestinal resection) and group II (141 patients without intestinal resection). The mean age in groups I and II were 69±16 and 60±17 years (p<0.05); the frequency in males was 70% in group I and 76% in group II (p>0.05). Intestinal obstruction and duration of incarceration >24 hours and the platelet-to-lymphocyte ratio demonstrated significant differences. With respect to NLR taking a cut-off point ≥6.5, a sensitivity of 75%, a specificity of 93.62%, a positive predictive value of 62.5% and a negative predictive value of 96.35% were observed; In addition, when analyzing with the ROC curve, a value of 5.14 was obtained as a predictor of intestinal resection with a sensitivity of 90% and a specificity of 84.4% (p<0.001). Therefore, the NLR >5.14 predicts intestinal resection in patients with incarcerated inguinal hernias with an area under the curve of 0.92 at the Belen Hospital of Trujillo. CONCLUSIONS: The neutrophil-to-lymphocyte ratio is useful for predicting intestinal resection with a diagnostic accuracy of 92%.


Asunto(s)
Hernia Inguinal , Obstrucción Intestinal , Linfocitos , Neutrófilos , Humanos , Masculino , Hernia Inguinal/cirugía , Hernia Inguinal/diagnóstico , Hernia Inguinal/sangre , Femenino , Persona de Mediana Edad , Anciano , Estudios Retrospectivos , Obstrucción Intestinal/etiología , Obstrucción Intestinal/cirugía , Obstrucción Intestinal/diagnóstico , Obstrucción Intestinal/sangre , Valor Predictivo de las Pruebas , Recuento de Linfocitos , Perú , Herniorrafia/métodos , Herniorrafia/efectos adversos , Intestinos/cirugía , Curva ROC
10.
J Minim Access Surg ; 19(2): 278-281, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36124470

RESUMEN

Introduction: Minimally invasive surgery has been established as the gold standard for the treatment of localised renal tumours. A retroperitoneal approach is a feasible option with advantages in posterior tumours and patients with previous abdominal surgeries. In this context, single-port retroperitoneoscopic partial nephrectomy (SPOR-PN) has not been widely explored and developed. We present this technique's description and our first results. Methods: We present a case series of nine patients undergoing SPOR-PN in a single institution. We used a multi-channel single-port access dispositive through a 35 mm incision below the 12th rib, a 30° two-dimensional laparoscope, curved graspers and needle drivers on the left hand and standard rigid material in the right hand. In all surgeries, we performed a complete renorrhaphy with the sliding-clip technique. The pain was evaluated through visual analogue scale (VAS) the day after surgery. Results: Patients' age ranged from 44 to 78 years. The median RENAL score was 5p, and the mean surgical time was 134 min. We performed an 'off-clamp' procedure on three patients. Among the patients who had renal artery clamped, the median ischaemia time was 18 min. The median in-hospital stay time was 48 h. Median VAS the day after surgery was 2. None of the anatomical pieces had positive borders. Only one complication was reported (Clavien IIIa). Conclusions: SPOR-PN is a feasible minimally invasive and nephron-sparing technique. The advantages of this procedure may not be only a better cosmetic appearance but also less post-operative pain. Further development and larger studies are needed.

11.
Khirurgiia (Mosk) ; (12. Vyp. 2): 78-80, 2022.
Artículo en Ruso | MEDLINE | ID: mdl-36562677

RESUMEN

Meckel's diverticulum is the most common congenital defect of the gastrointestinal tract. It is most often silent or asymptomatic. However, acute abdominal signs of obstruction, inflammation, hemorrhage and perforation are possible in other cases. Different foreign bodies can cause perforation of Meckel's diverticulum. We present an 18-year-old male who presented to the emergency department with abdominal pain within 48 previous hours. After evaluation, acute appendicitis was diagnosed and he underwent laparoscopic appendectomy. Meckel's diverticulum perforated by a fish bone was intraoperatively discovered. Incidental appendectomy and segmental resection of the ileum were performed.


Asunto(s)
Cuerpos Extraños , Perforación Intestinal , Divertículo Ileal , Masculino , Animales , Divertículo Ileal/complicaciones , Divertículo Ileal/diagnóstico , Divertículo Ileal/cirugía , Perforación Intestinal/diagnóstico , Perforación Intestinal/etiología , Perforación Intestinal/cirugía , Cuerpos Extraños/complicaciones , Cuerpos Extraños/diagnóstico , Dolor Abdominal , Inflamación
12.
Ecol Appl ; 30(6): e02116, 2020 09.
Artículo en Inglés | MEDLINE | ID: mdl-32145123

RESUMEN

Microclimatic conditions change dramatically as forests age and impose strong filters on community assembly during succession. Light availability is the most limiting environmental factor in tropical wet forest succession; by contrast, water availability is predicted to strongly influence tropical dry forest (TDF) successional dynamics. While mechanisms underlying TDF successional trajectories are not well understood, observational studies have demonstrated that TDF communities transition from being dominated by species with conservative traits to species with acquisitive traits, the opposite of tropical wet forest. Determining how functional traits predict TDF tree species' responses to changing environmental conditions could elucidate mechanisms underlying tree performance during TDF succession. We implemented a 6-ha restoration experiment on a degraded Vertisol in Costa Rica to determine (1) how TDF tree species with different resource-use strategies performed along a successional gradient and (2) how ecophysiological functional traits correlated with tree performance in simulated successional stages. We used two management treatments to simulate distinct successional stages including: clearing all remnant vegetation (early-succession), or interplanting seedlings with no clearing (mid-succession). We crossed these two management treatments (cleared/interplanted) with two species mixes with different resource-use strategies (acquisitive/conservative) to examine their interaction. Overall seedling survival after 2 yr was low, 15.1-26.4% in the four resource-use-strategy × management-treatment combinations, and did not differ between the management treatments or resource-use-strategy groups. However, seedling growth rates were dramatically higher for all species in the cleared treatment (year 1, 69.1% higher; year 2, 143.3% higher) and defined resource-use strategies had some capacity to explain seedling performance. Overall, ecophysiological traits were better predictors of species' growth and survival than resource-use strategies defined by leaf and stem traits such as specific leaf area. Moreover, ecophysiological traits related to water use had a stronger influence on seedling performance in the cleared, early-successional treatment, indicating that the influence of microclimatic conditions on tree survival and growth shifts predictably during TDF succession. Our findings suggest that ecophysiological traits should be explicitly considered to understand shifts in TDF functional composition during succession and that using these traits to design species mixes could greatly improve TDF restoration outcomes.


Asunto(s)
Bosques , Clima Tropical , Costa Rica , Plantones , Árboles
13.
Bull Environ Contam Toxicol ; 100(5): 620-626, 2018 May.
Artículo en Inglés | MEDLINE | ID: mdl-29508017

RESUMEN

Merida is the largest urban center in the Mexican State of Yucatan. Here domestic sewage is deposited in poorly built septic tanks and is not adequately treated. Because of contamination from such waste, water from the top 20 m of the aquifer is unsuitable for human consumption. Given this situation and because children are highly vulnerable to environmental pollution, including exposure to toxic trace elements, this study focused on evaluating the exposure of children to arsenic (As), chromium (Cr), and mercury (Hg) in water. It also evaluated the relationship between the levels of these elements in water and their concentrations in urine and blood. Among the 33 children monitored in the study, arsenic surpassed WHO limits for blood in 37% of the cases, which could result from the ingestion of poultry contaminated with organoarsenic compounds. In the case of WHO limits for Mercury, 65% of the water samples analyzed, 28% of urine samples, and 12% of blood samples exceeded them. Mercury exposure was correlated with biological sex, some lifestyle factors, and the zone in Merida in which children live. These data suggest that the levels of some toxic metals in children may be affected by water source, socioeconomic factors, and individual behavior.


Asunto(s)
Exposición a Riesgos Ambientales/estadística & datos numéricos , Contaminantes Ambientales/metabolismo , Oligoelementos/metabolismo , Animales , Arsénico/análisis , Arsénico/sangre , Arsénico/metabolismo , Arsénico/orina , Niño , Cromo/análisis , Cromo/metabolismo , Exposición a Riesgos Ambientales/análisis , Monitoreo del Ambiente , Contaminantes Ambientales/análisis , Agua Subterránea/química , Humanos , Mercurio/análisis , Mercurio/sangre , Mercurio/metabolismo , México , Aguas del Alcantarillado , Porcinos , Oligoelementos/análisis , Contaminantes Químicos del Agua/análisis
14.
Bull Environ Contam Toxicol ; 98(1): 14-21, 2017 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-27872973

RESUMEN

Mercury (Hg) compounds were used in the past in primers for rifle and handgun ammunition. Despite its toxicity, little is known about the contamination of shooting-range soils with this metal. We present new data about the Hg contamination of surface soils from numerous shooting ranges of Switzerland. Our study demonstrates that Hg is measurable at high levels in surface soils from the shooting ranges. In three of the investigated ranges, concentrations above the maximum Swiss guidance value of Hg in soil of 500 µg kg-1 were measured. Since the use of mercury-containing ammunition was stopped in the 1960s, our results demonstrate the high persistence of Hg in soils and their slow recovery by natural mechanisms.


Asunto(s)
Mercurio/análisis , Contaminantes del Suelo/análisis , Suelo/química , Medición de Riesgo
15.
Bull Environ Contam Toxicol ; 99(4): 452-459, 2017 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-28776191

RESUMEN

Studies investigating the correlation between metal content in water and metal levels in children are scarce worldwide, but especially in developing nations. Therefore, this study investigates the correlation between arsenic, chromium, and mercury concentrations in drinking and cooking water and in blood and urine samples collected from healthy and supposedly non-exposed children from a rural area in Yucatan, Mexico. Mercury in water shows concentrations above the recommended World Health Organization (WHO) value for drinking and cooking water. Also, 25% of the children show mercury in urine above the WHO recommended value. Multivariate analyses show a significant role for drinking and cooking water as a vector of exposure in children. Also, the factor analysis shows chronic exposure in the case of arsenic, as well as an ongoing detoxification process through urine in the case of mercury. Further studies should be done in order to determine other potential metal exposure pathways among children.


Asunto(s)
Arsénico , Cromo , Ingestión de Líquidos , Exposición a Riesgos Ambientales/análisis , Mercurio , Contaminantes Químicos del Agua , Arsénico/sangre , Arsénico/orina , Niño , Cromo/sangre , Cromo/orina , Agua Potable/análisis , Agua Potable/normas , Humanos , Mercurio/sangre , Mercurio/orina , México , Población Rural , Contaminantes Químicos del Agua/sangre , Contaminantes Químicos del Agua/orina
16.
Poult Sci ; 95(1): 41-52, 2016 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-26574033

RESUMEN

The effects of feed form and the inclusion of insoluble fiber in the diet on growth performance and water intake were studied in female broilers from 0 to 21 d of age. The experimental design was completely randomized with 14 treatments arranged as a 2 × 7 factorial with 2 feed forms (mash vs. pelleted) and 7 diets that consisted of a control diet low in fiber (1.6% crude fiber) based on broken rice, fermented soybean meal, and fish meal and 6 extra diets that resulted from the inclusion of 3 insoluble fiber sources (oat hulls; OH, rice hulls; RH, and sunflower hulls; SFH) at 2 levels (2.5 vs. 5%). Each treatment was replicated 6 times. Broilers fed pellets had 32% greater ADG and 3% better feed to gain ratio (F:G) than those fed mash (P ≤ 0.001). The inclusion of the fiber sources improved ADG (P ≤ 0.05) and F:G (P ≤ 0.05). Pelleting increased (P ≤ 0.001) water intake from 6 to 8 d, water-to-feed intake ratio from 18 to 20 d, and moisture content of the excreta at 20 d of age. The inclusion of the insoluble fiber sources increased water intake (P ≤ 0.05) from d 18 to 20 but not from d 6 to 8. Increasing the level of fiber inclusion from 2.5 to 5.0% tended to increase (P = 0.086) moisture content in the excreta at d 20. Pelleting and the inclusion of insoluble fiber sources improved ADG and F:G in broilers fed low-fiber diets, and the improvements observed were more pronounced with pellets than with mash. Growth performance of young broilers improves with the addition of moderate amounts of structural insoluble fiber in the diet, regardless of feed form. The inclusion of OH or SFH into low fiber diets was more beneficial for improving broiler performance than the inclusion of RH.


Asunto(s)
Alimentación Animal/análisis , Fenómenos Fisiológicos Nutricionales de los Animales , Pollos/fisiología , Dieta/veterinaria , Fibras de la Dieta/metabolismo , Animales , Avena/química , Pollos/crecimiento & desarrollo , Ingestión de Líquidos , Heces/química , Femenino , Helianthus/química , Oryza/química , Distribución Aleatoria
17.
Opt Lett ; 40(8): 1663-6, 2015 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-25872042

RESUMEN

Low-loss all-fiber photonic lantern (PL) mode multiplexers (MUXs) capable of selectively exciting the first six fiber modes of a multimode fiber (LP01, LP11a, LP11b, LP21a, LP21b, and LP02) are demonstrated. Fabrication of the spatial mode multiplexers was successfully achieved employing a combination of either six step or six graded index fibers of four different core sizes. Insertion losses of 0.2-0.3 dB and mode purities above 9 dB are achieved. Moreover, it is demonstrated that the use of graded index fibers in a PL eases the length requirements of the adiabatic tapered transition and could enable scaling to large numbers.

18.
Phys Rev Lett ; 114(9): 098104, 2015 Mar 06.
Artículo en Inglés | MEDLINE | ID: mdl-25793855

RESUMEN

We develop a percolation model motivated by recent experimental studies of gels with active network remodeling by molecular motors. This remodeling was found to lead to a critical state reminiscent of random percolation (RP), but with a cluster distribution inconsistent with RP. Our model not only can account for these experiments, but also exhibits an unusual type of mixed phase transition: We find that the transition is characterized by signatures of criticality, but with a discontinuity in the order parameter.

19.
Zootaxa ; (3802): 144-50, 2014 May 23.
Artículo en Inglés | MEDLINE | ID: mdl-24870999

RESUMEN

A new species of sea cucumber of the genus Lissothuria Verrill, 1867 is described. Lissothuria caboblanquensis n. sp. was found in the Costa Rican Pacific, at 17 m depth. The presence of towers with spiny apex and the elaborated shape of the hourglasses in the dorsal body wall, make this species unique among the species of this genus. This species is distinctive within the genus. The shape of the ossicles shows some similarities with L. nutriens H. L. Clark, 1901 and L. hancocki (Deichmann, 1941).


Asunto(s)
Pepinos de Mar/anatomía & histología , Pepinos de Mar/clasificación , Animales , Costa Rica
20.
Hear Res ; 444: 108969, 2024 03 15.
Artículo en Inglés | MEDLINE | ID: mdl-38350175

RESUMEN

Presbycusis or age-related hearing loss (ARHL) is one of the most prevalent chronic health problems facing aging populations. Along the auditory pathway, the stations involved in transmission and processing, function as a system of interconnected feedback loops. Regulating hierarchically auditory processing, auditory cortex (AC) neuromodulation can, accordingly, activate both peripheral and central plasticity after hearing loss. However, previous ARHL-prevention interventions have mainly focused on preserving the structural and functional integrity of the inner ear, overlooking the central auditory system. In this study, using an animal model of spontaneous ARHL, we aim at assessing the effects of multisession epidural direct current stimulation of the AC through stereotaxic implantation of a 1-mm silver ball anode in Wistar rats. Consisting of 7 sessions (0.1 mA/10 min), on alternate days, in awake animals, our stimulation protocol was applied at the onset of hearing loss (threshold shift detection at 16 months). Click- and pure-tone auditory brainstem responses (ABRs) were analyzed in two animal groups, namely electrically stimulated (ES) and non-stimulated (NES) sham controls, comparing recordings at 18 months of age. At 18 months, NES animals showed significantly increased threshold shifts, decreased wave amplitudes, and increased wave latencies after click and tonal ABRs, reflecting a significant, spontaneous ARHL evolution. Conversely, in ES animals, no significant differences were detected in any of these parameters when comparing 16 and 18 months ABRs, indicating a delay in ARHL progression. Electrode placement in the auditory cortex was accurate, and the stimulation did not cause significant damage, as shown by the limited presence of superficial reactive microglial cells after IBA1 immunostaining. In conclusion, multisession DC stimulation of the AC has a protective effect on auditory function, delaying the progression of presbycusis.


Asunto(s)
Corteza Auditiva , Presbiacusia , Ratas , Animales , Presbiacusia/prevención & control , Ratas Wistar , Envejecimiento/fisiología , Audición , Potenciales Evocados Auditivos del Tronco Encefálico/fisiología , Umbral Auditivo/fisiología
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