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1.
Front Microbiol ; 14: 1089156, 2023.
Article in English | MEDLINE | ID: mdl-36778890

ABSTRACT

The use of immunomodulatory and metabolic modulating drugs has been considered a better strategy to improve the efficacy of conventional treatments against pathogens and metabolic diseases. L-carnitine is relevant in fatty acid metabolism and energy production by ß-oxidation, but it also has a beneficial therapeutic immunomodulatory effect. The ß-hydroxy-γ-aminophosphonate (ß-HPC) was developed, synthesized and studied in different pathologies as a more soluble and stable analog than L-carnitine, which has been studied in bacterial physiology and metabolism; therefore, we set out to investigate the direct effect of ß-HPC on the metabolism of N. brasiliensis, which causes actinomycetoma in Mexico and is underdiagnosed. To analyze the effect of ß-HPC on the metabolic capacity of the bacterium for the hydrolysis of substrate casein, L-tyrosine, egg yolk, and tween 80, Fourier transform infrared spectroscopy (FT-IR) was employed. It was found that ß-HPC increases the metabolic activity of N. brasiliensis associated with increased growth and increased hydrolysis of the substrates tested. By the effect of ß-HPC, it was observed that, in the hydrolysis of L-tyrosine, the aromatic ring and functional groups were degraded. At 1515 cm-1, any distinctive signal or peak for this amino acid was missing, almost disappearing at 839, 720, 647, and 550 cm-1. In casein, hydrolysis is enhanced in the substrate, which is evident by the presence of NH, OH, amide, and CO. In casein, hydrolysis is enhanced in the substrate, which is evident by the presence of NH, OH, amide, COO, and P = O signals, characteristic of amino acids, in addition to the increase of the amide I and II bands. In Tween 80 the H-C = and C = C signals disappear and the ether signals are concentrated, it was distinguished by the intense band at 1100 cm-1. Egg yolk showed a large accumulation of phosphate groups at 1071 cm-1, where phosvitin is located. FT-IR has served to demonstrate that ß-HPC is a hydrolysis enhancer. Furthermore, by obtaining the spectrum of N. brasiliensis, we intend to use it as a quick comparison tool with other spectra related to actinobacteria. Eventually, FT-IR may serve as a species identification option.

2.
Phys Rev Lett ; 129(23): 239902, 2022 Dec 02.
Article in English | MEDLINE | ID: mdl-36563235

ABSTRACT

This corrects the article DOI: 10.1103/PhysRevLett.127.111803.

3.
Phys Rev Lett ; 127(11): 111803, 2021 Sep 10.
Article in English | MEDLINE | ID: mdl-34558934

ABSTRACT

We outline two important effects that are missing from most evaluations of the dark matter capture rate in neutron stars. As dark matter scattering with nucleons in the star involves large momentum transfer, nucleon structure must be taken into account via a momentum dependence of the hadronic form factors. In addition, due to the high density of neutron star matter, we should account for nucleon interactions rather than modeling the nucleons as an ideal Fermi gas. Properly incorporating these effects is found to suppress the dark matter capture rate by up to 3 orders of magnitude for the heaviest stars.

4.
J Alzheimers Dis ; 81(2): 769-785, 2021.
Article in English | MEDLINE | ID: mdl-33814431

ABSTRACT

BACKGROUND: Transmissible spongiform encephalopathies (TSEs) are rare neurodegenerative disorders that affect animals and humans. Bovine spongiform encephalopathy (BSE) in cattle, and Creutzfeld-Jakob Disease (CJD) in humans belong to this group. The causative agent of TSEs is called "prion", which corresponds to a pathological form (PrPSc) of a normal cellular protein (PrPC) expressed in nerve cells. PrPSc is resistant to degradation and can induce abnormal folding of PrPC, and TSEs are characterized by extensive spongiosis and gliosis and the presence of PrPSc amyloid plaques. CJD presents initially with clinical symptoms similar to Alzheimer's disease (AD). In AD, tau aggregates and amyloid-ß protein plaques are associated with memory loss and cognitive impairment in patients. OBJECTIVE: In this work, we study the role of tau and its relationship with PrPSc plaques in CJD. METHODS: Multiple immunostainings with specific antibodies were carried out and analyzed by confocal microscopy. RESULTS: We found increased expression of the glial fibrillary acidic protein (GFAP) and matrix metalloproteinase (MMP-9), and an exacerbated apoptosis in the granular layer in cases with prion disease. In these cases, tau protein phosphorylated at Thr-231 was overexpressed in the axons and dendrites of Purkinje cells and the extensions of parallel fibers in the cerebellum. CONCLUSION: We conclude that phosphorylation of tau may be a response to a toxic and inflammatory environment generated by the pathological form of prion.


Subject(s)
Cerebellum/metabolism , Creutzfeldt-Jakob Syndrome/pathology , Prion Diseases/pathology , tau Proteins/metabolism , Adult , Aged , Aged, 80 and over , Animals , Brain Diseases/metabolism , Brain Diseases/pathology , Cattle , Cerebellum/pathology , Creutzfeldt-Jakob Syndrome/metabolism , Encephalopathy, Bovine Spongiform/metabolism , Encephalopathy, Bovine Spongiform/pathology , Female , Humans , Male , Middle Aged , Prion Diseases/metabolism , Threonine/metabolism
5.
J Alzheimers Dis ; 79(4): 1517-1531, 2021.
Article in English | MEDLINE | ID: mdl-33459640

ABSTRACT

BACKGROUND: Alzheimer's disease (AD) and progressive supranuclear palsy (PSP) are examples of neurodegenerative diseases, characterized by abnormal tau inclusions, that are called tauopathies. AD is characterized by highly insoluble paired helical filaments (PHFs) composed of tau with abnormal post-translational modifications. PSP is a neurodegenerative disease with pathological and clinical heterogeneity. There are six tau isoforms expressed in the adult human brain, with repeated microtubule-binding domains of three (3R) or four (4R) repeats. In AD, the 4R:3R ratio is 1:1. In PSP, the 4R isoform predominates. The lesions in PSP brains contain phosphorylated tau aggregates in both neurons and glial cells. OBJECTIVE: Our objective was to evaluate and compare the processing of pathological tau in PSP and AD. METHODS: Double and triple immunofluorescent labeling with antibodies to specific post-translational tau modifications (phosphorylation, truncation, and conformational changes) and thiazin red (TR) staining were carried out and analyzed by confocal microscopy. RESULTS: Our results showed that PSP was characterized by phosphorylated tau in neurofibrillary tangles (NFTs) and glial cells. Tau truncated at either Glu391 or Asp421 was not observed. Extracellular NFTs (eNFTs) and glial cells in PSP exhibited a strong affinity for TR in the absence of intact or phosphorylated tau. CONCLUSION: Phosphorylated tau was as abundant in PSP as in AD. The development of eNFTs from both glial cells and neuronal bodies suggests that truncated tau species, different from those observed in AD, could be present in PSP. Additional studies on truncated tau within PSP lesions could improve our understanding of the pathological processing of tau and help identify a discriminatory biomarker for AD and PSP.


Subject(s)
Neurofibrillary Tangles/metabolism , Neuroglia/pathology , Neurons/pathology , Supranuclear Palsy, Progressive/metabolism , tau Proteins/metabolism , Alzheimer Disease/metabolism , Alzheimer Disease/pathology , Humans , Neurofibrillary Tangles/pathology , Neuroglia/metabolism , Neurons/metabolism , Supranuclear Palsy, Progressive/pathology
6.
Front Cell Neurosci ; 14: 247, 2020.
Article in English | MEDLINE | ID: mdl-33132840

ABSTRACT

Worldwide, around 50 million people have dementia. Alzheimer's disease (AD) is the most common type of dementia and one of the major causes of disability and dependency among the elderly worldwide. Clinically, AD is characterized by impaired memory accompanied by other deficiencies in the cognitive domain. Neuritic plaques (NPs) and neurofibrillary tangles (NFTs) are histopathological lesions that define brains with AD. NFTs consist of abundant intracellular paired helical filaments (PHFs) whose main constituent is tau protein. Tau undergoes posttranslational changes including hyperphosphorylation and truncation, both of which favor conformational changes in the protein. The sequential pathological processing of tau is illustrated with the following specific markers: pT231, TG3, AT8, AT100, and Alz50. Two proteolysis sites for tau have been described-truncation at glutamate 391 and at aspartate 421-and which can be demonstrated by reactivity with the antibodies 423 and TauC-3, respectively. In this review, we describe the molecular changes in tau protein as pre-NFTs progress to extracellular NFTs and during which the formation of a minimal nucleus of the filament, as the PHF core, occurs. We also analyzed the PHF core as the initiator of PHFs and tau phosphorylation as a protective neuronal mechanism against the assembly of the PHF core.

7.
J Alzheimers Dis ; 76(3): 853-862, 2020.
Article in English | MEDLINE | ID: mdl-32568191

ABSTRACT

We recently developed the National Dementia Biobank in México (BioBanco Nacional de Demencias, BND) as a unit for diagnosis, research, and tissue transfer for research purposes. BND is associated with the Facultad de Estudios Superiores Cuautitlán, Universidad Nacional Autónoma de Mexico (UNAM), Mexico. The donation of fluids, brain, and other organs of deceased donors is crucial for understanding the underlying mechanisms of neurodegenerative diseases and for the development of successful treatment. Our laboratory research focuses on 1) analysis of the molecular processing of the proteins involved in those neurodegenerative diseases termed tauopathies and 2) the search for biomarkers for the non-invasive and early diagnosis of Alzheimer's disease.


Subject(s)
Alzheimer Disease/pathology , Biological Specimen Banks , Brain/pathology , Neurodegenerative Diseases/pathology , Tauopathies/pathology , Biological Specimen Banks/standards , Biomarkers/metabolism , Brain/metabolism , Humans , Mexico , tau Proteins/metabolism
8.
J Adolesc Young Adult Oncol ; 9(1): 90-95, 2020 02.
Article in English | MEDLINE | ID: mdl-31663803

ABSTRACT

Purpose: Treatment of pediatric cancers and hematological malignancies requires long periods of isolation in a sterile room. To promote family connections, telepresence robots have been made available in the homes of hospitalized patients. Our aim was to evaluate the perceived benefits and difficulties encountered by users and their families in terms of family dynamics. We also evaluated the presence of the robot on the medical caregivers' therapeutic relationship and organization of daily care. Methods: An observational study was undertaken with semistructured face-to-face interviews of 17 patients (aged 7 to 25 years) and their parents conducted by a psychologist on day +15 after provision of the robot and then after the patients had gone home, as well as face-to-face interviews of 15 caregivers by a philosopher before the robots were made available and at day +21. Results: One of the main perceived benefits expressed by the patients was maintenance of a connection with their siblings and retention of their role in the family. For parents, the device provided reassurance of being able to stay in touch with their child. The nursing staff indicated that the devices allowed them to develop more than a professional relationship with the child and to interact with their extended family. Limitations of the virtual nature of the nursing staff/family relationship were also noted, such as potential frustration for patients when they witness things that they cannot access and a degree of concern for the parents during periods of disconnection. Conclusions: This study revealed an overall perceived benefit for patients, their families, and caregivers. It also highlighted relevant issues and it provides guidelines for broader application of such devices.


Subject(s)
Hematologic Neoplasms/epidemiology , Robotics/instrumentation , Social Isolation/psychology , Adolescent , Adult , Child , Female , Hospitalization , Humans , Male , Qualitative Research , Young Adult
9.
Comp Biochem Physiol B Biochem Mol Biol ; 135(1): 177-82, 2003 May.
Article in English | MEDLINE | ID: mdl-12781984

ABSTRACT

We explored the possibility that the hormone 3,3',5-tri-iodothyronine can regulate the biosynthesis of the mitochondrial calcium uniporter. To meet this objective experiments on Ca(2+) transport, and binding of the specific inhibitor Ru(360) were carried out in mitochondria isolated from euthyroid, hyperthyroid and hypothyroid rats. It was found that V(max) for Ca(2+) transport increased from 11.67+/-0.8 in euthyroid to 14.36+/-0.44 in hyperthyroid, and decreased in hypothyroid mitochondria to 8.62+/-0.63 nmol Ca(2+)/mg/s. Furthermore, the K(i) for the specific inhibitor Ru(360), depends on the thyroid status, i.e. 18, 19 and 13 nM for control, hyper- and hypothyroid mitochondria, respectively. In addition, the binding of 103Ru(360) was increased in hyperthyroid and decreased in hypothyroid mitochondria. Scatchard analysis for the binding of 103Ru(360) showed the following values: 28, 40 and 23 pmol/mg for control, hyper- and hypothyroid mitochondria, respectively. The K(d) for 103Ru(360) was found to be 30.39, 37.03 and 35.71 nM for controls, hyper- and hypothyroid groups, respectively. When hypothyroid rats were treated with thyroid hormone, mitochondrial Ca(2+) transport, as well as 103Ru(360) binding, reached similar values to those found for euthyroid mitochondria.


Subject(s)
Calcium-Binding Proteins/metabolism , Mitochondria, Liver/metabolism , Triiodothyronine/physiology , Animals , Biological Transport , Calcium/metabolism , Calcium Channels , Calcium-Binding Proteins/analysis , Energy Metabolism , Hyperthyroidism/metabolism , Hypothyroidism/metabolism , Mitochondria, Liver/drug effects , Rats , Ruthenium Compounds/chemistry , Triiodothyronine/pharmacology
10.
Life Sci ; 70(20): 2413-20, 2002 Apr 05.
Article in English | MEDLINE | ID: mdl-12150205

ABSTRACT

The influence of substrates on the role of cyclosporin A, to promote the closure of the permeability transition pore, was studied. It was found that in succinate-oxidizing mitochondria, cyclosporin inhibited pore opening as induced by carboxyatractyloside. The opposite occurred when mitochondrial respiration was supported by malate-glutamate, i.e., cyclosporin A was unable to block pore opening promoted by carboxyatractyloside. We propose that the failure of cyclosporin A to induce pore closure could be due to a low NADH matrix content.


Subject(s)
Atractyloside/analogs & derivatives , Cyclosporine/pharmacology , Immunosuppressive Agents/pharmacology , Mitochondria/drug effects , Adenosine Diphosphate/pharmacology , Animals , Atractyloside/pharmacology , Calcium/pharmacology , In Vitro Techniques , Kidney/drug effects , Kidney/metabolism , Male , Membranes/drug effects , Membranes/metabolism , NAD/metabolism , Oxidation-Reduction , Permeability/drug effects , Rats , Succinates/metabolism
11.
Arch Cardiol Mex ; 72 Suppl 1: S27-30, 2002.
Article in Spanish | MEDLINE | ID: mdl-12001860

ABSTRACT

This work describes experimental results indicating that mitochondria from hypothyroid rats are resistant to suffer membrane permeability transition as induced by matrix calcium accumulation. It is also shown that hypothyroidism provides resistance to myocardial reperfusion injury, after a period of 5 min ischemia. It is concluded that the protection is due to a low expression of mitochondrial proteins, as well as to a lack in cardiolipin as constituent of the lipid bilayer of the inner mitochondrial membrane.


Subject(s)
Hypothyroidism/metabolism , Mitochondria/physiology , Reperfusion Injury/prevention & control , Animals , Rats
12.
Rev. psiquiatr. salud ment ; 17(3): 162-66, jul.-sept. 2000. graf
Article in Spanish | LILACS | ID: lil-277151

ABSTRACT

Se presenta la evaluación de 1 año de tratamiento de pacientes con diagnóstico de depresión de género femenino y mayores de 20 años en atención primaria del Servicio de Salud Concepción. Luego de la capacitación respectiva, se atendieron 2.398 mujeres, de las cuales 794 abandonaron tratamiento. 489 fueron dadas de alta y 1.115 permanecen en tratamiento. La aplicación de ese programa de atención planteó dificultades en cuanto a la disponibilidad de fármacos, horas profesionales y significó un desmedro del resto de las atenciones en salud mental. Fue positivo en cuanto a que benefició a un número importante de paciente


Subject(s)
Humans , Female , Adult , Middle Aged , Primary Health Care/statistics & numerical data , Depression/epidemiology , Psychotherapy, Group/statistics & numerical data , Chile/epidemiology , Antidepressive Agents/supply & distribution , Antidepressive Agents/therapeutic use , Depression/drug therapy , Residence Characteristics/statistics & numerical data , Epidemiology, Descriptive
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