Effect of ß - hydroxy - γ -aminophosphonate (ß - HPC) on the hydrolytic activity of Nocardia brasiliensis as determined by FT-IR spectrometry.

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.

Fibropapillomatosis dynamics in green sea turtles Chelonia mydas over 15 years of monitoring in Akumal Bay, Quintana Roo, Mexico.

Fibropapillomatosis (FP) is a tumor disease that affects all sea turtle species but is mainly seen in green turtles Chelonia mydas. The pathology of FP has been described extensively, but its dynamics in populations over time have been less studied. We analyzed the dynamics of FP in a population of green turtles in Akumal Bay on the central coast of the Mexican Caribbean. A total of 475 green turtles were captured over 15 yr (2004-2018). The highest prevalence of FP was found in the largest turtles, and there was a positive relationship between FP prevalence and size of turtles. FP was first detected in 2008 at a prevalence of 1.6%, and annual prevalence increased markedly from 17.9% in 2015 to 54% by 2018. Likewise, severity of FP increased over time, with most turtles falling into moderately to severely diseased categories (tumor score 2). The average size of turtles with FP was significantly larger than the size of individuals without FP. Regression of tumors was seen in 21% of turtles, tumor score was higher in smaller individuals, and only tumor score 2 was present in the largest sea turtles. An increase in the prevalence and tumor score of FP coincided with the massive arrival of Sargassum in 2015, suggesting that altered environmental conditions may have played a role. The increased prevalence of FP in Akumal Bay prompts the need to explain what might be driving this phenomenon and how widespread it is in the Caribbean.

PHF-Core Tau as the Potential Initiating Event for Tau Pathology in Alzheimer's Disease.

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.

National Dementia BioBank: A Strategy for the Diagnosis and Study of Neurodegenerative Diseases in México.

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.

Immunological evaluation of captive green sea turtle (Chelonia mydas) with ulcerative dermatitis.

Ulcerative dermatitis (UD) is common in captive sea turtles and manifests as skin erosions and ulcers associated with gram-negative bacteria. This study compared clinically healthy and UD-affected captive turtles by evaluating hematology, histopathology, immunoglobulin levels, and delayed-type hypersensitivity assay. Turtles with UD had significantly lower weight, reduced delayed-type hypersensitivity (DTH) responses, and higher heterophil:lymphocyte ratios. This study is the first to assay DTH in green turtles (Chelonia mydas) and suggests that UD is associated with immunosuppression.

Identification of CD3+ T lymphocytes in the green turtle Chelonia mydas.

To understand the role of the immune system with respect to disease in reptiles, there is the need to develop tools to assess the host's immune response. An important tool is the development of molecular markers to identify immune cells, and these are limited for reptiles. We developed a technique for the cryopreservation of peripheral blood mononuclear cells and showed that a commercially available anti-CD3 epsilon chain antibody detects a subpopulation of CD3 positive peripheral blood lymphocytes in the marine turtle Chelonia mydas. In the thymus and in skin inoculated with phytohemagglutinin, the same antibody showed the classical staining pattern observed in mammals and birds. For Western blot, the anti-CD3 antibodies identified a 17.6k Da band in membrane proteins of peripheral blood mononuclear cell compatible in weight to previously described CD3 molecules. This is the first demonstration of CD3+ cells in reptiles using specific antibodies.