Development of a biodegradable prosthesis through tissue engineering, for the organ-replacement or substitution of the extrahepatic bile duct.

INTRODUCTION AND OBJECTIVES: There are different situations in which an extrahepatic bile duct replacement or substitute is needed, such as initial and localized stages of bile duct cancer, agenesis, stenosis, or bile duct disruption. MATERIALS AND METHODS: A prosthesis obtained by electrospinning composed of Poly (D,L-lactide-co-glycolide) (PGLA) - Polycaprolactone (PCL) - Gelatin (Gel) was developed, mechanical and biological tests were carried out to evaluate resistance to tension, biocompatibility, biodegradability, cytotoxicity, morphological analysis and cell culture. The obtained prosthesis was placed in the extrahepatic bile duct of 15 pigs with a 2-year follow-up. Liver function tests and cholangioscopy were evaluated during follow-up. RESULTS: Mechanical and biological evaluations indicate that this scaffold is biocompatible and biodegradable. The prosthesis implanted in the experimental model allowed cell adhesion, migration, and proliferation, maintaining bile duct permeability without altering liver function tests. Immunohistochemical analysis indicates the presence of biliary epithelium. CONCLUSIONS: A tubular scaffold composed of electrospun PGLA-PCL-Gel nanofibers was used for the first time to replace the extrahepatic bile duct in pigs. Mechanical and biological evaluations indicate that this scaffold is biocompatible and biodegradable, making it an excellent candidate for use in bile ducts and potentially in other tissue engineering applications.

Interpretable Classification of Tauopathies with a Convolutional Neural Network Pipeline Using Transfer Learning and Validation against Post-Mortem Clinical Cases of Alzheimer's Disease and Progressive Supranuclear Palsy.

Neurodegenerative diseases, tauopathies, constitute a serious global health problem. The etiology of these diseases is unclear and an increase in their incidence has been projected in the next 30 years. Therefore, the study of the molecular mechanisms that might stop these neurodegenerative processes is very relevant. Classification of neurodegenerative diseases using Machine and Deep Learning algorithms has been widely studied for medical imaging such as Magnetic Resonance Imaging. However, post-mortem immunofluorescence imaging studies of the brains of patients have not yet been used for this purpose. These studies may represent a valuable tool for monitoring aberrant chemical changes or pathological post-translational modifications of the Tau polypeptide. We propose a Convolutional Neural Network pipeline for the classification of Tau pathology of Alzheimer's disease and Progressive Supranuclear Palsy by analyzing post-mortem immunofluorescence images with different Tau biomarkers performed with models generated with the architecture ResNet-IFT using Transfer Learning. These models' outputs were interpreted with interpretability algorithms such as Guided Grad-CAM and Occlusion Analysis. To determine the best classifier, four different architectures were tested. We demonstrated that our design was able to classify diseases with an accuracy of 98.41% on average whilst providing an interpretation concerning the proper classification involving different structural patterns in the immunoreactivity of the Tau protein in NFTs present in the brains of patients with Progressive Supranuclear Palsy and Alzheimer's disease.

Motor Imagery Analysis from Extensive EEG Data Representations Using Convolutional Neural Networks.

Motor imagery is a complex mental task that represents muscular movement without the execution of muscular action, involving cognitive processes of motor planning and sensorimotor proprioception of the body. Since the mental task has similar behavior to that of the motor execution process, it can be used to create rehabilitation routines for patients with some motor skill impairment. However, due to the nature of this mental task, its execution is complicated. Hence, the classification of these signals in scenarios such as brain-computer interface systems tends to have a poor performance. In this work, we study in depth different forms of data representation of motor imagery EEG signals for distinct CNN-based models as well as novel EEG data representations including spectrograms and multidimensional raw data. With the aid of transfer learning, we achieve results up to 93% accuracy, exceeding the current state of the art. However, although these results are strong, they entail the use of high computational resources to generate the samples, since they are based on spectrograms. Thus, we searched further for alternative forms of EEG representations, based on 1D, 2D, and 3D variations of the raw data, leading to promising results for motor imagery classification that still exceed the state of the art. Hence, in this work, we focus on exploring alternative methods to process and improve the classification of motor imagery features with few preprocessing techniques.

Tracking Host Trees: The Phylogeography of Endemic Psittacanthus sonorae (Loranthaceae) Mistletoe in the Sonoran Desert.

The host dependence of mistletoes suggests that they track the distributions of their hosts. However, the factors that determine the geographic distribution of mistletoes are not well understood. In this study, the phylogeography of Psittacanthus sonorae was reconstructed by sequencing one nuclear (ITS) and two plastid (trnL-F and atpB-rbcL) regions of 148 plants from populations separated by the Sea of Cortez. Divergence time and gene flow were estimated to gain insight into the historical demography and geographic structuring of genetic variation. We also described and mapped the spatial distribution of suitable habitat occupied by P. sonorae and its most common host Bursera microphylla in the Sonoran Desert, along with their responses to Quaternary climate fluctuations using environmental data and ecological niche modeling (ENM). We detected environmental and genetic differentiation between the peninsular and continental P. sonorae populations. Population divergence occurred during the Pleistocene, around the time of the Last Glacial Maximum. No signals of population growth were detected, with net gene flow moving from the continent to the peninsula. ENM models indicate decoupled responses by the mistletoe and its main host to past climate changes. For the Last Interglacial to the present, most models produce only partial areas of overlap on both the peninsula and the continent. Our results support a scenario of Late-Pleistocene isolation and divergence with asymmetrical gene flow between peninsular and continental P. sonorae populations. Continental populations migrated to the peninsula and the spatial isolation probably produced genetic differentiation under different environmental conditions.

Relative Body Mass Index Improves the BMI Percentile Performance for Detection and Monitoring of Excess Adiposity in Adolescents.

Obesity is defined as excess adipose tissue; however, commonly used methods may under-detect adiposity in adolescents. This study compared the performance of body mass index percentile (BMI%) and relative body mass index (RBMI) in identifying excess body fat percentage (BF%) and estimated RBMI cut points to better stratify severity of adiposity. In 567 adolescents ages 11-19 year, BF% measured by DXA was used to compare BMI% and RBMI performance at different degrees of adiposity. RBMI cut points for adiposity detection were derived via ROC curve analysis. BF% was strongly correlated with BMI% (r = 0.889, p < 0.001) and RBMI (r = 0.901, p < 0.001). However, RBMI exhibited less dispersion and better discriminated the relationship with BF% independent of age, race, and gender. Both BMI% and RBMI performed similarly for detecting high BF% (≥25 BF% in males; ≥30 BF% in females). Nonetheless, the relationship of BMI% with BF% was diminished among leaner adolescents. RBMI detected overweight in 21.3% more females and 14.2% more males. RBMI improved the detection of excess adiposity in individuals otherwise classified as having normal weight or overweight by BMI%. RBMI is a valuable and accessible tool for earlier detection, intervention, and effective follow-up of excess adiposity in youth at higher risk for complications.

Subcutaneous Application of a Gelatin/Hyaluronic Acid Hydrogel Induces the Production of Skin Extracellular Matrix.

The development of injectable hydrogels with natural biopolymers such as gelatin (Ge) and hyaluronic acid (Ha) is widely performed due to their biocompatibility and biodegradability. The combination of both polymers crosslinked with N-Ethyl-N'-(3-dimethyl aminopropyl) carbodiimide hydrochloride (EDC) can be used as an innovative dermal filler that stimulates fibroblast activity and increases skin elasticity and tightness. Thus, crosslinked Ge/Ha hydrogels with different concentrations of EDC were administered subcutaneously to test their efficacy in young and old rats. At higher EDC concentrations, the viscosity decreases while the particle size of the hydrogels increases. At all concentrations of EDC, amino and carboxyl groups are present. The histological analysis shows an acute inflammatory response, which disappears seven days after application. At one and three months post-treatment, no remains of the hydrogels are found, and the number of fibroblasts increases in all groups in comparison with the control. In addition, the elastic modulus of the skin increases after three months of treatment. Because EDC-crosslinked Ge/Ha hydrogels are biocompatible and induce increased skin tension, fibroblast proliferation, and de novo extracellular matrix production, we propose their use as a treatment to attenuate wrinkles and expression lines.

Hypoglycemic effect of Carica papaya leaves in streptozotocin-induced diabetic rats.

BACKGROUND: Traditional plant treatment for diabetes has shown a surging interest in the last few decades. Therefore, the purpose of this study was to assess the hypoglycemic effect of the aqueous extract of C. papaya leaves in diabetic rats. Several studies have reported that some parts of the C. papaya plant exert hypoglycemic effects in both animals and humans. METHODS: Diabetes was induced in rats by intraperitoneal administration of 60 mg/kg of streptozotocin (STZ). The aqueous extract of C. papaya was administered in three different doses (0.75, 1.5 and 3 g/100 mL) as drinking water to both diabetic and non-diabetic animals during 4 weeks. RESULTS: The aqueous extract of Carica papaya (0.75 g and 1.5 g/100 mL) significantly decreased blood glucose levels (p<0.05) in diabetic rats. It also decreased cholesterol, triacylglycerol and amino-transferases blood levels. Low plasma insulin levels did not change after treatment in diabetic rats, but they significantly increased in non-diabetic animals. Pancreatic islet cells were normal in non-diabetic treated animals, whereas in diabetic treated rats, C. papaya could help islet regeneration manifested as preservation of cell size. In the liver of diabetic treated rats, C. papaya prevented hepatocyte disruption, as well as accumulation of glycogen and lipids. Finally, an antioxidant effect of C. papaya extract was also detected in diabetic rats. CONCLUSIONS: This study showed that the aqueous extract of C. papaya exerted a hypoglycemic and antioxidant effect; it also improved the lipid profile in diabetic rats. In addition, the leaf extract positively affected integrity and function of both liver and pancreas.

Seed predation and potential seed dispersers of the narrow endemic Ceratozamianorstogii (Zamiaceae).

In this study, we report the observation of potential seed dispersers of the endemic to Mexico and narrowly distributed Ceratozamianorstogii (Zamiaceae). Camera traps were installed in front of two plants of Ceratozamianorstogii and cone phenology until their maturity and disintegration was determined. The female cone of Ceratozamianorstogii has a development of ten months, from the time it emerges until it disintegrates. We were able to identify three stages of cone development: 1) Pre-pollination phase, 2) Pollination phase and 3) Seed maturation phase. Our results support an animal-dispersal hypothesis in Ceratozamia. Three mammals [a mouse (Pteromiscus sp.), a southern spotted skunk (Spilogaleangustifrons) and a kinkajou (Potusflavus)] were recorded biting, carrying or removing seeds of Ceratozamianorstogii. The camera traps recorded no evidence of birds or other mammals coming to the cones to feed. Thus, interaction of frugivores with seeds occurs at night. The most frequent visitor was the mouse, followed by the southern spotted skunk and the kinkajou. Significant differences (GLM, p< 0.05) in visitor frequency and time for interaction were found between species. We believe that the mouse is probably the most effective seed disperser for Ceratozamianorstogii. The results presented here have evolutionary implications that can be scaled to the entire genus Ceratozamia. Specifically, short-distance dispersal promotes allopatric speciation in this group of plants.

A Novel Automatic Quantification Protocol for Biomarkers of Tauopathies in the Hippocampus and Entorhinal Cortex of Post-Mortem Samples Using an Extended Semi-Siamese U-Net.

Efforts have been made to diagnose and predict the course of different neurodegenerative diseases through various imaging techniques. Particularly tauopathies, where the tau polypeptide is a key participant in molecular pathogenesis, have significantly increased their morbidity and mortality in the human population over the years. However, the standard approach to exploring the phenomenon of neurodegeneration in tauopathies has not been directed at understanding the molecular mechanism that causes the aberrant polymeric and fibrillar behavior of the tau protein, which forms neurofibrillary tangles that replace neuronal populations in the hippocampal and cortical regions. The main objective of this work is to implement a novel quantification protocol for different biomarkers based on pathological post-translational modifications undergone by tau in the brains of patients with tauopathies. The quantification protocol consists of an adaptation of the U-Net neural network architecture. We used the resulting segmentation masks for the quantification of combined fluorescent signals of the different molecular changes tau underwent in neurofibrillary tangles. The quantification considers the neurofibrillary tangles as an individual study structure separated from the rest of the quadrant present in the images. This allows us to detect unconventional interaction signals between the different biomarkers. Our algorithm provides information that will be fundamental to understanding the pathogenesis of dementias with another computational analysis approach in subsequent studies.

Effects of high rosuvastatin doses on hepatocyte mitochondria of hypercholesterolemic mice.

Statins are the cornerstone of therapy for individuals with hyperlipidemia. The aim of this study was to analyze the undesirable effects of mild, moderate and high doses of rosuvastatin in CD-1 male mice who received a cholesterol-rich diet, focusing on the morphological and functional changes on hepatocyte mitochondria. In a mouse model we studied the combined administration of a cholesterol-rich diet along with mild and moderate doses of rosuvastatin (1, 2.5 or 5 mg/kg/day) during several days. After the animals were sacrificed, liver mitochondria were isolated for microscopic studies and to analyze the respiratory function. The respiratory control (state-3/state-4) was evaluated in mice who received high doses of rosuvastatin. Rosuvastatin doses higher than 20 mg/kg/day induced premature death in mice with a hypercholesterolemic diet, but not in mice with a cholesterol-free diet. Doses from 2.5 to 5 mg/kg/day also induced morphological and functional alterations in mitochondria but these hypercholesterolemic animals survived longer. Giving 1 mg/kg/day, which is close to the maximal therapeutic dose for humans, did not affect mitochondrial architecture or respiratory function after two months of treatment. We analyzed the effect of rosuvastatin on hepatic tissue because it is where statins are mainly accumulated and it is the main site of endogenous cholesterol synthesis. Our results contribute to understand the side effects of rosuvastatin in hypercholesterolemic mice, effects that could also affect humans who are intolerant to statins.

An absence of cilia outer microtubules, an etiology not previously recognized in bilateral mucocele.

Most paranasal sinus mucoceles are unilateral and affect one or at most two contiguous sinuses. We describe the case of a 44-year-old woman with bilateral maxillary sinus mucoceles who presented clinically with left malar pain, right-sided swelling, and proptosis of the right eye. The diagnostic workup included computed tomography and magnetic resonance imaging. In addition, because of the atypical bilateral presentation, we analyzed mucosal sinonasal tissue samples by electron microscopy. Microscopic analysis revealed an absence of one of the microtubule doublets in three of the outer doublets of the axoneme, thereby establishing a diagnosis of isolated ciliary dysfunction. To the best of our knowledge, ciliary dysfunction as a cause of bilateral mucoceles has not been previously reported in the literature. The patient underwent successful surgery for removal of the mucoceles, and she exhibited no evidence of recurrence at the 18-month follow-up. When a diagnosis of bilateral mucocele formation is made, we suggest that ciliary dysfunction be considered in the differential diagnosis and that electron microscopy of the sinonasal mucosa be performed in the workup.

Protective Action of Carica papaya on ß-Cells in Streptozotocin-Induced Diabetic Rats.

The aim of the present study was to investigate the effect of C. papaya L. leaf extract (CPLE) on pancreatic islets in streptozotocin (STZ)-induced diabetic rats, as well as on cultured normal pancreatic cells with STZ in the medium. CPLE (3-125 mg/Kg) was administered orally for 20 days, while a group of diabetic rats received 5 IU/Kg/day of insulin. At the end of the treatment the rats were sacrificed. Blood was obtained to assess glucose and insulin levels. The pancreas was dissected to evaluate ß cells by immunohistochemistry. In addition, normal pancreatic cells were cultured in a medium that included CPLE (3-12 mg). One half of the cultured cells received simultaneously CPLE and STZ (6 mg), while the other half received CPLE and five days later the STZ. After three days of incubation, insulin was assayed in the incubation medium. The CPLE administered to diabetic rats improved the fasting glycemia and preserved the number and structure of pancreatic islets. However, when CPLE was added to pancreatic cells in culture along with STZ, the insulin concentration was higher in comparison with the cells that only received STZ. In conclusion, the CPLE preserves the integrity of pancreatic islets, improves the basal insulin secretion and protects cultured cells from the adverse effects of STZ.

Bone Marrow Mesenchymal Stromal Cells from Clinical Scale Culture: In Vitro Evaluation of Their Differentiation, Hematopoietic Support, and Immunosuppressive Capacities.

The differentiation capacity, hematopoietic support, and immunomodulatory properties of human bone marrow mesenchymal stromal cells (BM-MSCs) make them attractive therapeutic agents for a wide range of diseases. Clinical scale cultures (CSCs) have been used to expand BM-MSCs for their use in cell therapy protocols; however, little is known about the functionality of the expanded cells. The main goal of the present study was to evaluate the functional characteristics of BM-MSCs expanded from CSCs to determine the quality of the cells for cellular therapy protocols. To address this issue, we analyzed the morphology, immunophenotype, differentiation potential (adipogenic, osteogenic and chondrogenic), hematopoietic support, and immunosuppressive capacity of BM-MSCs from short scale cultures (SSCs) and CSCs in a comparative manner. After 12 days of culture in CSCs (HYPERFlask System), BM-MSCs reached cell numbers of 125.52 × 10(6) ± 25.6 × 10(6) MSCs, which corresponded to the number of cells required for transplantation (∼1.7 × 10(6) MSCs/kg for a 70-kg patient). After expansion, BM-MSCs expressed the characteristic markers CD73, CD90, and CD105; however, expansion decreased their differentiation capacity toward the adipogenic, osteogenic, and chondrogenic lineages and their ability to inhibit T-cell proliferation compared with SSCs-MSCs. Importantly, CSCs-MSCs maintained the ability to support the proliferation and expansion of hematopoietic progenitor cells and the capacity to express the molecules, cytokines, and extracellular matrix proteins involved in the regulation of hematopoiesis. Our study highlights the need to evaluate the functional properties of the expanded BM-MSCs for verification of their quality for cell therapy protocols.

Efectos cardiovasculares de la xilazina en conejos: estudios in vivo e in vitro / Cardiovascular Effects of Xylazine in Rabbits: In vivo and In vitro Studies

La xilazina es un agonista de receptores a2-adrenérgicos, la cual ha sido ampliamente utilizada como sedante y analgésico en Medicina Veterinaria. Sus efectos cardiovasculares han sido atribuidos a acciones directas y/o indirectas, actuando sobre sus órganos blancos y/o modulando el tono autonómico, respectivamente. El objetivo de esta investigación fue determinar los efectos de la xilazina in vivo sobre la presión arterial media (PAM) y la frecuencia cardiaca (FC) en conejos albinos Nueva Zelanda, y evaluar sus efectos in vitro en aurícula derecha y en vena safena aisladas. Se anestesiaron e instrumentaron cuatro conejos, para medir la PAM en forma directa y la FC mediante electrocardiografía. Una vez estabilizadas las variables hemodinámicas, se evaluaron dosis crecientes-acumulativas de xilazina intravenosa. Se determinó el efecto de concentraciones crecientes-acumulativas de xilazina sobre la aurícula derecha y vena safena en órganos aislados convencionales. Se evaluaron  los efectos de xilazina sobre la frecuencia cardiaca (lat/min) y la fuerza de contracción (g) auricular, y sobre la vena safena, en ausencia y presencia de prazosín (30nM) y yohimbina (0,1µM). La xilazina in vivo, causó una respuesta bifásica en la PAM, caracterizada por un aumento ligero, seguido de una profunda hipotensión dosis-dependiente, acompañada de bradicardia. En la aurícula derecha, la xilazina no causó modificaciones en su actividad espontánea, aunque en la vena safena produjo contracciones concentración-dependiente sensibles a yohimbina, pero resistentes a prazosín. Los resultados sugieren que la xilazina endovenosa causa reducción en la PAM y bradicardia en el conejo anestesiado, sin modificar las propiedades cronotrópicas e inotrópicas de la aurícula derecha aislada. Sin embargo, en la vena safena aislada, se demuestra que la xilazina causa vasocontracción, primordialmente a través de la acción sobre receptores a2-adrenérgicos. La xilazina ejerce efectos ...

Xylazine is an a2-adrenoceptor agonist widely employed in Veterinary Medicine as a sedative and analgesic compound. Xylazine cardiovascular effects have been attributed to direct and/or indirect actions, acting on target organs and/or modulating the autonomic outflow, respectively. The aim of this investigation was to determine the in vivo effect of xylazine on mean blood pressure (MBP) and heart rate (HR) in albino New Zealand rabbits and to assess the in vitro effects of xylazine on the isolated  right atrium and saphenous vein. Four rabbits were anesthetized and instrumentalized for directly measuring  MBP; and HR by electrocardiography respectively. After the stabilization of haemodynamic variables, intravenous cumulative increasing doses of xylazine were administered and evaluated.The effects of xylazine cumulative concentration-response curves on  the isolated right atrium and on the saphenous vein in conventional in vitro organ bath studies were assessed. Contraction rate (beats/min) and contraction force (g) were measured in the right atrium. Xylazine-induced contraction (g) in the absence and presence of prazosin (30nM) and yohimbine (0.1µM) was measured in the isolated saphenous vein. The intravenous administration of xylazine caused a biphasic response on the MBP, characterized by slight increase followed by a profound dose-dependent hypotension along with bradycardia. Xylazine did not modify the spontaneous activity of the isolated right atrium, although, yohimbine-sensitive and prazosin-resistant concentration-dependent contractions by xylazine were observed in the isolated saphenous vein. The results suggest that intravenous administration of xylazine causes a reduction in the MBP and bradycardia in the anesthetized rabbit, without a clear modification on the chronotropic and inotropic properties of the isolated right atrium. Nevertheless, xylazine caused vasocontraction of the isolated saphenous vein, primarily by activating ...

Clinical efficacy of a petroleum-derived product (Larimsh) used as compassionate treatment in patients with terminal prostate cancer.

Treatment of a light fraction of petroleum treated by metallic catalysis results in a liquid mixture of low molecular weight compounds named LarimshTM (LR). Acute and chronic topical treatment of mice with LR (85 days with 0.1 to 1 mL/animal) indicated no signs of toxicity other than a non dose-dependent, reversible alopecia appearing by the 4th week of topical application. Alopecia completely reversed 2 weeks after treatment withdrawal. Acute oral LR (0.001 to 1 mL; the lowest doses diluted in corn oil as vehicle) gave an estimated LD50 of 21 g/kg (C.I. 95 %: 10.94-41.2 g/kg. LR density = 0.867 g/mL). The antineoplastic action of LR was observed using combined oral and topical treatments in mice; inoculated with a lymphoid leukemia cell line in ascitic phase (International Registry L5178Y); and in terminal patients with prostate cancer (TPCA)--who agreed to receive LR as a compassionate treatment. The survival time for mice was significantly increased when compared with non-treated inoculated mice (51 +/- 2 versus 38 +/- 2 days, p < 0.05, mean +/- SD, N = 6 per group). In 15 patients, LR treatment for 5.5 months (C.I. 95 %: 2.9 to 8.0 months) significantly increased the expected survival time diagnosed to TPCA by their treating physicians (C.I. 95 %: 2.2 to 5.4 versus 12.6 to 41.2 months, p < 0.05) which occurred concomitantly with a significant reduction of blood levels of total prostatic antigen (average 94.5%, range: 67.3 to 99.9%). A theoretical proposal is advanced as a likely explanation of LR actions.

Effects of single administration of diethylstilbestrol on murine langerhans cells.

Diethylstilbestrol (DES) is a synthetic compound with potent estrogenic actions useful in the treatment of prostate carcinoma despite the fact that it can also induce some forms of neoplasia. Both effects are thought to be related to its estrogenic actions and very little attention has been focused on the possible effect of DES on the immune response. Skin is the largest organ of the body and constitutes the first line of defense against xenobiotics. The Skin Immune System (SIS) has become the center of attention of research for the development of new therapeutic approaches for neoplasic diseases. Langerhans cells (LC), as an element of SIS, are "professional" antigen presenting cells resident in the skin that participate in the immune response associated with tolerance and acquired immunity to antigens. Hence in this work we studied the effect of DES on LC of murine skin as a model to analyze the possible effect of DES on the immune response. Male CD-1 mice (20 to 35 g body weight) were treated topically (TO) or subcutaneously (SC) with DES (10 and 100 mg/kg, dissolved in ethanol) and sacrificed at 12, 84 and 228 hr. LC were quantified in the ear skin of mice using both an enzymatic histochemical technique to demonstrate ATP-ase activity; and an indirect immunohistochemical assay for detecting class II molecules of the major histocompatibility complex (MHC-II). DES induced a significant time- and dose- dependent reduction in the number of LC (P < 0.05). Data presented here suggest that estrogens may exert a modulatory action on LC.