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1.
J Clin Med ; 13(13)2024 Jun 30.
Artículo en Inglés | MEDLINE | ID: mdl-38999428

RESUMEN

Introduction: Benign paroxysmal positional vertigo (BPPV) stands as the most common cause of peripheral vertigo. Its treatment with repositioning maneuvers on an examination table is highly effective. However, patients with back or neck problems, paraplegia, or other conditions face challenges with these maneuvers, potentially experiencing longer healing times and creating additional difficulties for physicians diagnosing and treating BPPV in everyday practice. The emergence of mechanical rotational chairs (MRCs) offers a more convenient alternative for performing these maneuvers. Objectives: The primary objective was to compare the effectiveness of maneuvers on the examination table with those on MRCs in BPPV patients diagnosed in the emergency room and randomly classified into one of the treatment options. The secondary objectives included a comparison of patient quality of life during BPPV episodes and after their resolution and an analysis of recurrences and associated risk factors. Methods: This was a cohort study on sixty-three patients diagnosed with BPPV in the emergency department. Patients were classified into two cohorts depending on diagnostic and treatment maneuvers (MRC or conventional repositioning maneuvers (CRMs)) and received weekly follow-ups until positioning maneuvers became negative. Subsequent follow-ups were conducted at 1 month, 3 months, and 6 months after the resolution of vertigo. Patients were classified into two groups based on their assigned treatment method. Results: Thirty-one patients were treated with CRMs and 32 with TRV. Mean age was 62.29 ± 17.67 years and the most affected canal was the PSC (96.8%). The mean number of required maneuvers was two, while 55.56% only required one maneuver until resolution. Recurrence was present in 26.98% of the patients during the 6-month follow-up. Comparing both cohorts, there were no statistically significant differences between treatments (TRV vs. CRM) regarding the number of maneuvers, number of recurrences, and days until remission of BPPV. Dizziness Handicap Inventory and Visual Analogue Scale values decreased considerably after BPPV resolution, with no statistically significant differences between the groups. Age was identified as a covariable in the number of maneuvers and days until BPPV resolution, showing that an increase in age implies a greater need of maneuvers. Conclusions: There was no difference between the means of treatment for BPPV in our population ot There was no difference between the groups of treatments for BPPV in our population. The quality of life of patients improved six months after the resolution of BPPV, regardless of the treatment applied.

2.
Adv Mater ; 36(28): e2402723, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38665115

RESUMEN

Magnetism in two dimensions is traditionally considered an exotic phase mediated by spin fluctuations, but far from collinearly ordered in the ground state. Recently, 2D magnetic states have been discovered in layered van der Waals compounds. Their robust and tunable magnetic state by material composition, combined with reduced dimensionality, foresee a strong potential as a key element in magnetic devices. Here, a class of 2D magnets based on metallic chlorides is presented. The magnetic order survives on top of a metallic substrate, even down to the monolayer limit, and can be switched from perpendicular to in-plane by substituting the metal ion from iron to nickel. Using functionalized STM tips as magnetic sensors, local exchange fields are identified, even in the absence of an external magnetic field. Since the compounds are processable by molecular beam epitaxy techniques, they provide a platform with large potential for incorporation into current device technologies.

3.
Mar Pollut Bull ; 202: 116368, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38678732

RESUMEN

The balance between marine health and ecosystem sustainability confronts a pressing threat from anthropogenic pollution. Estuaries are particularly susceptible to contamination, notably by anthropogenic microfibers originated from daily human activities in land and in fishing practices. This study examines the impact of anthropogenic microfibers on the whitemouth croaker in an estuarine environment of the Southwestern Atlantic Ocean during cold and warm seasons. The presence of anthropogenic microfibers was revealed in 64 % of juvenile gastrointestinal tracts, and 94 % of water samples, and concentrations were influenced by factors such as temperature, bay zone, and fish body length. Blue and black anthropogenic microfibers, with a rather new physical aspect, were dominant. This study highlights the impact of microfibers in a heavily anthropized body of water, subject to federal and local regulations due to the presence of commercially significant fish species inhabiting this area.


Asunto(s)
Monitoreo del Ambiente , Animales , Océano Atlántico , Peces , Estuarios , Contaminantes Químicos del Agua/análisis , Perciformes
4.
Rev Argent Microbiol ; 56(2): 191-197, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38272730

RESUMEN

Water kefir is a sparkling, slightly acidic fermented beverage made from sugar, water, and water kefir grains, which are a mixture of yeast and bacteria. These grains produce a variety of fermentation compounds such as lactic acid, acetaldehyde, acetoin, ethanol and carbon dioxide. In this study, a high-throughput sequencing technique was used to characterize the bacterial composition of the original water kefir from which potential probiotics were obtained. We studied the bacterial diversity of both water kefir grains and beverages. DNA was extracted from three replicate samples of both grains and beverages using the Powerlyzer Microbial Kit. The hypervariable V1-V2 region of the bacterial 16S ribosomal RNA gene was amplified to prepare six DNA libraries. Between 1.4M and 2.4M base-pairs were sequenced for the library. In total, 28721971 raw reads were obtained from all the samples. Estimated species richness was higher in kefir beverage samples compared to grain samples. Moreover, a higher level of microbial alpha diversity was observed in the beverage samples. Particularly, the predominant bacteria in beverages were Anaerocolumna and Ralstonia, while in grains Liquorilactobacillus dominated, with lower levels of Leuconostoc and Oenococcus. Although the bacterial diversity in kefir grains was low because only three genera were the most represented, all of them are LAB bacteria with the potential to serve as probiotics in the artificial feeding of bees.


Asunto(s)
Bacterias , Kéfir , Metagenómica , Probióticos , ARN Ribosómico 16S , Animales , Abejas/microbiología , Kéfir/microbiología , ARN Ribosómico 16S/genética , Metagenómica/métodos , Bacterias/aislamiento & purificación , Bacterias/genética , Bacterias/clasificación , ADN Bacteriano/análisis , Biodiversidad , ADN Ribosómico/genética , Alimentación Animal/microbiología
6.
Rev. méd. Panamá ; 43(3): 68-70, 31 de diciembre de 2023.
Artículo en Español | LILACS-Express | LILACS | ID: biblio-1524226

RESUMEN

La rotura espontánea de bazo es una complicación infrecuente pero muy grave de la mononucleosis infecciosa. Dada la urgencia con la que suele presentarse tal situación, la esplenectomía suele ser la opción quirúrgica más utilizada. Presentamos el caso de un paciente en el que con el diagnóstico de rotura esplénica espontánea se somete a laparoscopia diagnóstica en la que se consigue la preservación del bazo con buena evolución clínica. A la luz de este paciente, consideramos que, en caso de estabilidad clínica y hematomas subcapsulares de bazo, la laparoscopia con preservación esplénica es una opción viable y con buenos resultados. (provisto por Infomedic International)


Spontaneous rupture of the spleen is a rare but very serious complication of infectious mononucleosis. Given the urgency with which such a situation usually presents, splenectomy is usually the most used surgical option. We present the case of a patient diagnosed with spontaneous splenic rupture who underwent diagnostic laparoscopy in which spleen preservation was achieved with good clinical evolution. In the light of this patient, we consider that, in the case of clinical stability and subcapsular haematomas of the spleen, laparoscopy with splenic preservation is a viable option with good results. (provided by Infomedic International)

7.
Ann Rheum Dis ; 82(12): 1594-1605, 2023 12.
Artículo en Inglés | MEDLINE | ID: mdl-37666646

RESUMEN

BACKGROUND: The vacuoles, E1-enzyme, X linked, autoinflammatory and somatic (VEXAS) syndrome is an adult-onset autoinflammatory disease (AID) due to postzygotic UBA1 variants. OBJECTIVES: To investigate the presence of VEXAS syndrome among patients with adult-onset undiagnosed AID. Additional studies evaluated the mosaicism distribution and the circulating cytokines. METHODS: Gene analyses were performed by both Sanger and amplicon-based deep sequencing. Patients' data were collected from their medical charts. Cytokines were quantified by Luminex. RESULTS: Genetic analyses of enrolled patients (n=42) identified 30 patients carrying UBA1 pathogenic variants, with frequencies compatible for postzygotic variants. All patients were male individuals who presented with a late-onset disease (mean 67.5 years; median 67.0 years) characterised by cutaneous lesions (90%), fever (66.7%), pulmonary manifestations (66.7%) and arthritis (53.3%). Macrocytic anaemia and increased erythrocyte sedimentation rate and ferritin were the most relevant analytical abnormalities. Glucocorticoids ameliorated the inflammatory manifestations, but most patients became glucocorticoid-dependent. Positive responses were obtained when targeting the haematopoietic component of the disease with either decitabine or allogeneic haematopoietic stem cell transplantation. Additional analyses detected the UBA1 variants in both haematopoietic and non-haematopoietic tissues. Finally, analysis of circulating cytokines did not identify inflammatory mediators of the disease. CONCLUSION: Thirty patients with adult-onset AID were definitively diagnosed with VEXAS syndrome through genetic analyses. Despite minor interindividual differences, their main characteristics were in concordance with previous reports. We detected for the first time the UBA1 mosaicism in non-haematopoietic tissue, which questions the previous concept of myeloid-restricted mosaicism and may have conceptual consequences for the disease mechanisms.


Asunto(s)
Artritis , Mosaicismo , Adulto , Humanos , Masculino , Femenino , Citocinas/genética , Ferritinas , Glucocorticoides , Mutación
8.
Rev. argent. microbiol ; 55(2): 10-10, jun. 2023. graf
Artículo en Inglés | LILACS-Express | LILACS | ID: biblio-1449408

RESUMEN

Abstract We evaluated the microbial composition of water kefir grains and beverage overthe course of one year to determine whether the number and type of microorganisms changedover the time. Bacteria and yeast colonies with different morphologies were isolated fromwater kefir and their antimicrobial activity was evaluated against Paenibacillus larvae andAscosphaera apis. A chemical characterization of kefir was also carried out. Our results con-firmed that bacteria and yeasts were more numerous in kefir grains compared with those in thebeverage. The counts of microorganisms declined, although an important microbial community was still present in kefir after the long storage period. Eleven strains which inhibited bee pathogens were isolated from kefir. Genotypic results demonstrated that these isolates included Lentilactobacillus hilgardii, Lentilactobacillus buchneri and Saccharomyces cerevisiae. Thus, water kefir may be an innovative source of potential probiotic strains for bee nutrition in order to control honeybee diseases.


Resumen Evaluamos la composición microbiana del kéfir de agua durante un ano para determinar si la cantidad y el tipo de microorganismos cambiaban con el tiempo. Se aislaron colonias de bacterias y de levaduras con diferentes morfologías, y su actividad antimicrobiana se evaluó frente a Paenibacillus larvaey Ascosphaeraapis. También se realizó una caracterización química del kéfir. Nuestros resultados confirmaron que las bacterias y las levaduras eran más numerosas en los gránulos de kéfir en comparación con la parte líquida. Los recuentos de microorganismos disminuyeron, aunque una cantidad igualmente importante se encontró en el kéfir después de un año. Se aislaron del kéfir once cepas que inhibieron los mencionados patógenos de abejas. Los resultados genotípicos demostraron que estos aislamientos eran Lentilactobacillus hilgardii, Lentilactobacillus buchneri y Saccharomyces cerevisiae. Por lo tanto, el kéfir de agua podría ser una fuente innovadora de potenciales cepas probióticas para contribuir a la nutrición y sanidad de las abejas.

9.
Rev Argent Microbiol ; 55(2): 176-180, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-36481105

RESUMEN

We evaluated the microbial composition of water kefir grains and beverage over the course of one year to determine whether the number and type of microorganisms changed over the time. Bacteria and yeast colonies with different morphologies were isolated from water kefir and their antimicrobial activity was evaluated against Paenibacillus larvae and Ascosphaera apis. A chemical characterization of kefir was also carried out. Our results confirmed that bacteria and yeasts were more numerous in kefir grains compared with those in the beverage. The counts of microorganisms declined, although an important microbial community was still present in kefir after the long storage period. Eleven strains which inhibited bee pathogens were isolated from kefir. Genotypic results demonstrated that these isolates included Lentilactobacillus hilgardii, Lentilactobacillus buchneri and Saccharomyces cerevisiae. Thus, water kefir may be an innovative source of potential probiotic strains for bee nutrition in order to control honeybee diseases.


Asunto(s)
Kéfir , Probióticos , Abejas , Animales , Kéfir/microbiología , Agua , Bebidas/microbiología , Bacterias , Saccharomyces cerevisiae , Fermentación
11.
Nat Commun ; 13(1): 4341, 2022 Jul 27.
Artículo en Inglés | MEDLINE | ID: mdl-35896541

RESUMEN

Earth-abundant electrocatalysts for the oxygen evolution reaction (OER) able to work in acidic working conditions are elusive. While many first-row transition metal oxides are competitive in alkaline media, most of them just dissolve or become inactive at high proton concentrations where hydrogen evolution is preferred. Only noble-metal catalysts, such as IrO2, are fast and stable enough in acidic media. Herein, we report the excellent activity and long-term stability of Co3O4-based anodes in 1 M H2SO4 (pH 0.1) when processed in a partially hydrophobic carbon-based protecting matrix. These Co3O4@C composites reliably drive O2 evolution a 10 mA cm-2 current density for >40 h without appearance of performance fatigue, successfully passing benchmarking protocols without incorporating noble metals. Our strategy opens an alternative venue towards fast, energy efficient acid-media water oxidation electrodes.

12.
Fish Physiol Biochem ; 48(2): 321-335, 2022 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-35146595

RESUMEN

This work aimed to evaluate the whole-organism and cellular level responses to different combinations of water temperature and salinity of the notothenioid Patagonotothen cornucola at the end of the yolk-sac larval stage. Egg masses of the species were collected in the wild and then maintained at natural water conditions (4 °C and 30 PSU). Newly hatched larvae were placed in aquaria with different combinations of water temperature (4 °C, 12 °C, and 16 °C) and salinity (15 and 30 PSU) during four days before yolk sac absorption. Larvae exposed to 12 °C grew more in length than those exposed to 16 °C, but yolk volume was more reduced in larvae exposed to 16 °C than those exposed to 4 °C and 30 PSU than of 15 PSU. In addition, a higher proportion of larvae exposed to 12 °C and 15 PSU completely absorbed their yolk. Whereas the more tolerant larvae to high temperatures were those exposed to 16 °C and 30 PSU, lipid peroxidation and protein oxidation were highest at natural and at 12 °C and 30 PSU conditions, respectively. The nutritional status (as standardized DNA/RNA index-sRD -) was low in all cases, even at natural conditions (average sRD ~ 1). Our study suggests that, in the context of climate change, the mortality rate of yolk-sac larvae of P. cornucola would not increase due to temperature or salinity stress. However, indirect effects (such as habitat degradation or changes in food availability) would be critical after complete absorption of the yolk.


Asunto(s)
Perciformes , Salinidad , Animales , Peces , Larva , Perciformes/fisiología , Temperatura , Agua , Saco Vitelino
13.
Mol Genet Genomics ; 296(6): 1299-1311, 2021 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-34564766

RESUMEN

A phylogenomic study conducted with different bioinformatic tools such as TYGS, REALPHY and AAI comparisons revealed a high rate of misidentified Streptomyces albus genomes in GenBank. Only 9 of the 18 annotated genomes available in the public database were correctly identified as S. albus species. The pangenome of the nine in silico confirmed S. albus genomes was almost closed. Lignocellulosic agroresidues were a common niche among strains of the S. albus clade while carbohydrate active enzymes (CAZymes) were highly conserved. Relevant enzymes for cellulose degradation such as beta glucosidases belonging to the GH1 family, a GH6 cellulase and a monooxygenase AA10-CBM2 were encoded by all S. albus genomes. Among them, one GH1 glycosidase would be regulated by CebR. However, this regulatory mechanism was not confirmed for other genes related to cellulose degradation. Based on AntiSMASH predictions, the core secondary metabolome of S. albus encompassed a total of 23 biosynthetic gene clusters (BGCs), where 4 were related to common metabolites within Streptomyces genus. Species specific BGCs included those related to pseudouridimycin and xantholipin. Additionally, four BGCs encoded putative derivatives of ibomycin, the lasso peptide SSV-2086, the lanthipeptide SapB and the terpene isorenieratene. Known metabolites could not be assigned to ten BGCs and three clusters did not match with any previously described BGC. The core genome of S. albus retrieved from nine closely related genomes revealed a high potential for the discovery of novel bioactive metabolites and underexplored regulatory genomic elements related to lignocellulose deconstruction.


Asunto(s)
Celulasas/genética , Genoma Bacteriano/genética , Lignina/metabolismo , Streptomyces/genética , Streptomyces/metabolismo , Bases de Datos Genéticas , Glicósido Hidrolasas/genética , Metaboloma/genética , Oxigenasas de Función Mixta/genética , Familia de Multigenes/genética , Filogenia , Metabolismo Secundario/genética
14.
ACS Nano ; 15(9): 14985-14995, 2021 Sep 28.
Artículo en Inglés | MEDLINE | ID: mdl-34491033

RESUMEN

Metal halides are a class of layered materials with promising electronic and magnetic properties persisting down to the two-dimensional limit. While most recent studies focused on the trihalide components of this family, the rather unexplored metal dihalides are also van der Waals layered systems with distinctive magnetic properties. Here we show that the dihalide NiBr2 grows epitaxially on a Au(111) substrate and exhibits semiconducting and magnetic behavior starting from a single layer. Through a combination of a low-temperature scanning-tunneling microscopy, low-energy electron diffraction, X-ray photoelectron spectroscopy, and photoemission electron microscopy, we identify two competing layer structures of NiBr2 coexisting at the interface and a stoichiometrically pure layer-by-layer growth beyond. Interestingly, X-ray absorption spectroscopy measurements revealed a magnetically ordered state below 27 K with in-plane magnetic anisotropy and zero-remanence in the single layer of NiBr2/Au(111), which we attribute to a noncollinear magnetic structure. The combination of such two-dimensional magnetic order with the semiconducting behavior down to the 2D limit offers the attractive perspective of using these films as ultrathin crystalline barriers in tunneling junctions and low-dimensional devices.

15.
Mycologia ; 113(3): 513-524, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33764859

RESUMEN

The selection of fast-growing and high-yield-producing strains is required to satisfy the market demand on fungal food supplements. To that aim, three strains deposited in our collection as G. lucidum and G. oregonense were screened for polysaccharide production and biomass yield. Ganoderma strains deposited as G. lucidum were identified as G. sessile and G. lingzhi by nuc rDNA internal transcribed spacer ITS1-5.8S-ITS2 (ITS) and translation elongation factor 1-α (TEF1-α) phylogenies. The identity of G. oregonense was confirmed by molecular phylogeny and biogeography. Additionally, mycelial antagonism confirmed species differentiation, and strains were further distinguished by morphology and protein profiles. Biomass and polysaccharide yields of G. sessile were clearly different from those of G. lingzhi and G. oregonense in both liquid culture and solid-state fermentation. The maximum polysaccharide yield (4.52 ± 0.83 g L-1) for G. sessile was obtained from submerged cultures at day 9. G. sessile also achieved the highest linear growth in lignocellulosic solid substrates. Consequently, basidiomata were successfully obtained by solid-state fermentation in polypropylene bags, whereas G. lingzhi and G. oregonense mushrooms were not produced in artificial solid substrates. G. sessile, a species frequently collected in America, showed to be a promising polysaccharide producer for the manufacture of dietary supplements.


Asunto(s)
Ganoderma , Reishi , Fermentación , Ganoderma/genética , Polisacáridos
16.
J Laparoendosc Adv Surg Tech A ; 31(4): 395-401, 2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-33617729

RESUMEN

Background: During transanal total mesorectal excision (TaTME), sustained dilation of the anal canal occurs, which can cause anatomical and functional damage to the sphincter complex. This study aimed to analyze the impact of laparoscopic total mesorectal excision (LaTME) and TaTME in anorectal sphincter function. Materials and Methods: An observational study was conducted comparing two cohorts of patients who underwent LaTME or TaTME for rectal cancer. The two groups were paired for comparison based on age, gender, and distance of the neoplasm to the anal margin. The anorectal function was assessed by manometry before surgery and at least 6 months after primary intervention or stoma closure. The intestinal function was assessed using the low anterior resection syndrome (LARS) score. Results: Twenty-two patients were included. There were no significant differences in baseline characteristics between groups except for the time between surgery and testing. A decrease in the mean resting and squeeze pressures between pre- and postoperative manometry was observed in both the treatment groups, the difference being only significant in the squeeze pressure values (TaTME P = .003; LaTME P = .004). After surgery, squeeze pressure reduction correlated with a worsening of the LARS point count (rho 0.587; P = .004). The time elapsed since surgery was negatively correlated with the LARS point count (rho -0.696; P = .001) and the difference between pre- and postoperative mean squeeze pressures (rho -0.499; P = .018). Conclusion: Manometric findings after TME are comparable between the laparoscopic and the transanal approach. Deterioration of both anal sphincter function and LARS improves with time after surgery.


Asunto(s)
Canal Anal/cirugía , Complicaciones Posoperatorias/cirugía , Neoplasias del Recto/cirugía , Recto/cirugía , Cirugía Endoscópica Transanal , Adulto , Anciano , Defecación , Femenino , Humanos , Laparoscopía , Masculino , Manometría , Persona de Mediana Edad , Periodo Posoperatorio , Proctectomía , Síndrome , Resultado del Tratamiento
17.
J Fish Biol ; 98(1): 132-141, 2021 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-32984950

RESUMEN

The Argentine hake, Merluccius hubbsi, is one of the most important fishing species in the Argentine Sea due to its great abundance and high-quality meat. The study of the nutritional condition is widely used to determine the physiological state of the fish larvae and to estimate their survival possibilities. The larval nutritional condition reflects the environmental conditions to which they have been exposed and represents a useful instrument to determine favourable nursery areas. It also provides tools for the comprehensive management of a population subjected to fishing exploitation. This study aimed to determine potential differences in the nutritional condition of M. hubbsi larvae from the two fishing stocks (Northern and Southern) of the species. The authors assessed the nutritional condition of larvae captured during the 2012 main reproductive peak in the nursery areas of each population. Two different methodologies were applied: a morphometrical approach, by recording five morphometric variables, and a biochemical technique, employing the RNA/DNA index (RDs ) and its derived index of growth performance. The morphometrical indexes did not show differences in the larval condition between both stocks. Nonetheless, the RDs index did detect differences in the nutritional condition of larvae from different stocks. The RDs index of larvae in pre-flexion and flexion stages showed significant differences between stocks, indicating that these stages are more susceptible to starvation. The results suggest that the biochemical indexes prove to be more sensitive than the morphometric indexes to detect slight differences in hake larvae nutritional condition. The scope and limitations of these techniques for the analysis of the nutritional condition of larvae are discussed.


Asunto(s)
Crianza de Animales Domésticos/métodos , Explotaciones Pesqueras , Gadiformes/anatomía & histología , Gadiformes/fisiología , Estado Nutricional/fisiología , Animales , Biomarcadores/análisis , ADN/análisis , Gadiformes/genética , ARN/análisis
18.
Biochim Biophys Acta Mol Cell Biol Lipids ; 1865(10): 158767, 2020 10.
Artículo en Inglés | MEDLINE | ID: mdl-32736090

RESUMEN

The presence, biosynthesis and functional role of sterols in the green microalga Haematococcus pluvialis remain poorly understood. In this work we studied the effect of high-light (HL) stress on sterol synthesis in H. pluvialis UTEX 2505 cells. HL stress induced the synthesis of sterols in parallel with that of triacylglycerides (TAG), giving rise to the synthesis of cholesterol over that of phytosterols. Blockage of the carotenogenic 1-deoxy-D-xylulose 5-phosphate (MEP) pathway is shown to be involved in HL-induced sterol synthesis. In addition, high irradiance exposure induced MEP- and fatty acid (FA)-biosynthetic transcripts. The pharmacological inhibition of these pathways suggests a possible feedback regulation of sterol and FA homeostasis. Finally, both lipid classes proved crucial to the adequate photosynthetic performance of H. pluvialis grown under HL intensity stress. Our findings reveal new insights into H. pluvialis lipid metabolism that contribute to the development of value-added bioproducts from microalgae.


Asunto(s)
Metabolismo de los Lípidos/efectos de la radiación , Lípidos/genética , Fotosíntesis/genética , Esteroles/metabolismo , Ácidos Grasos/genética , Ácidos Grasos/metabolismo , Luz , Metabolismo de los Lípidos/genética , Microalgas/genética , Microalgas/metabolismo , Microalgas/efectos de la radiación , Fotosíntesis/efectos de la radiación , Estrés Fisiológico/genética , Estrés Fisiológico/efectos de la radiación , Xantófilas/metabolismo , Xantófilas/efectos de la radiación
19.
J Morphol ; 281(6): 578-590, 2020 06.
Artículo en Inglés | MEDLINE | ID: mdl-32271483

RESUMEN

The Argentine hake Merluccius hubbsi is an important fishery resource of the Southwestern Atlantic Ocean and it is also a potential species for cultivation. In this work, the digestive system development in field-caught hake larvae was studied using histological and histochemical approaches. The digestive tract of larvae was divided into: oropharyngeal cavity (OPC), esophagus, stomach (that develops in the preflexion stage), and intestine. The annexed digestive glands consisted of the liver and the exocrine pancreas. At the beginning of the preflexion stage, teeth were developed in the OPC. There were mucous cells in the esophagus secreting different glycoconjugates from hatching. The enterocytes in the posterior intestine exhibited supranuclear vesicles associated with protein absorption. Mucous cells were observed in the posterior intestine in the preflexion stage and, in the anterior region, ending the flexion stage. Each type of glycoconjugates has a specific role. Acidic mucins lubricate and protect from mechanical damage, sialomucines protect from bacterial infections and neutral mucins regulate the acidity of mucus secretion, protect against abrasion and participate in the formation of the chyme, indicating a pregastric digestion. The liver was present since hatching with pancreatic tissue inside and increased in size acquiring the typical structure with hepatocyte cords, sinusoids, vacuoles, and hepatic duct. The hepatocytes vacuolization increased with larval development. The pancreas became extra-hepatic, with basophilic acinar cells and acidophilic zymogen granules. Throughout the ontogeny, the increased structural and functional complexity of the digestive system reflected the transition to exogenous feeding and nutritional increasing needs.


Asunto(s)
Gadiformes/crecimiento & desarrollo , Tracto Gastrointestinal/crecimiento & desarrollo , Animales , Tracto Gastrointestinal/anatomía & histología , Tracto Gastrointestinal/citología , Glicoconjugados/metabolismo , Larva/citología , Larva/crecimiento & desarrollo , Moco/metabolismo
20.
J Morphol ; 281(4-5): 465-475, 2020 04.
Artículo en Inglés | MEDLINE | ID: mdl-32092182

RESUMEN

During the early ontogeny of fish larvae, the accurate development of the visual system plays a key role, because it is involved in locating food, orientation, selection of favorable habitat, and evasion of predators. The structure of the eye of the fish is typical of vertebrates, with some modifications related to the aquatic environment. In the present work, we describe the development of the larval eye of Engraulis anchoita for the first time. Larvae were collected at the Permanent Station of Environmental Studies (EPEA) in coastal waters of the Southwestern Atlantic Ocean during research cruises in 2015 and 2016. We describe the histology of the retina layers, determine the beginning of the functionality of the eye, and discuss a possible synchronization with the development of the digestive tract. This study provides information about the biology of E. anchoita, the most abundant fish species in the southwestern Atlantic Ocean. Also, recent studies have shown responses of the retina and other tissues to the increase in environmental acidity. Therefore, results of this study are also discussed with respect to the possible effect of acidification on the larvae of this species. The continuity of the time series developed at the EPEA will allow monitoring the effect of long-term environmental and biological variables on the early ontogeny of anchovy in the context of climate change. The high commercial fishing potential of E. anchoita due to its high abundance, as well as its essential role in the trophic web of other commercially valuable fishing resources of Argentina, reinforce the need to continue deepening knowledge about this species. Research highlights: Eyes of Engraulis anchoita larvae are functional from early larval stages. At hatching, the retina is formed by only few layers from which the other layers differentiates during ontogeny. Focal distance increases with larval growth.


Asunto(s)
Ojo/anatomía & histología , Ojo/crecimiento & desarrollo , Peces/anatomía & histología , Peces/crecimiento & desarrollo , Animales , Argentina , Ecosistema , Ojo/citología , Geografía , Larva/anatomía & histología , Larva/crecimiento & desarrollo , Retina/anatomía & histología , Retina/citología , Retina/crecimiento & desarrollo
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