Performance of Colombian Silk Fibroin Hydrogels for Hyaline Cartilage Tissue Engineering.

The development and evaluation of scaffolds play a crucial role in the engineering of hyaline cartilage tissue. This work aims to evaluate the performance of silk fibroin hydrogels fabricated from the cocoons of the Colombian hybrid in the in vitro regeneration of hyaline cartilage. The scaffolds were physicochemically characterized, and their performance was evaluated in a cellular model. The results showed that the scaffolds were rich in random coils and ß-sheets in their structure and susceptible to various serine proteases with different degradation profiles. Furthermore, they showed a significant increase in ACAN, COL10A1, and COL2A1 expression compared to pellet culture alone and allowed GAG deposition. The soluble portion of the scaffold did not affect chondrogenesis. Furthermore, they promoted the increase in COL1A2, showing a slight tendency to differentiate towards fibrous cartilage. The results also showed that Colombian silk could be used as a source of biomedical devices, paving the way for sericulture to become a more diverse economic activity in emerging countries.

The role of the multi-drug resistance 1, p53, b cell lymphoma 2, and bcl 2-associated X genes in the biologic behavior and chemotherapeutic resistance of canine transmissible venereal tumors.

BACKGROUND: Canine transmissible venereal tumors (CTVTs) generally have different cytomorphologic subtypes and phases of progression. Some tumors have variable biologic behavior including a progressive increase in tumor aggressiveness and variable responses to chemotherapy. This behavior is partially due to high p-glycoprotein expression by tumor cells, which leads to the expulsion of chemotherapeutic drugs. Other possible causes include changes in pro- and anti-apoptotic genes from the BCL-2 family and DNA repair systems, which are associated with the p53 gene family. OBJECTIVES: We aimed to determine the relative expression of the multi-drug resistance 1 (MDR1), p53, b-cell lymphoma 2 (BCL2), and bcl 2-associated X (BAX) genes in CTVT before and after therapy and establish a relationship with treatment responses, cytomorphologic patterns, and tumor progression identified with histopathology. METHODS: RT-qPCR was performed on 21 CTVT tumor samples before and after initiating chemotherapy to determine specific gene expression. Normal canine testicular tissue was used as a negative control for all experiments. RESULTS: MDR1 expression was decreased before and after initiating vincristine therapy in CTVT tumor tissues compared with normal canine testicular tissue; p53 and BAX were overexpressed at both time points compared with normal tissue, and no statistical differences were seen between the different morphologic types. However, BAX expression was decreased in the group with quick therapeutic responses but was still overexpressed compared with normal testicular tissue. In the group with the slowest chemotherapeutic responses, BCL2 was overexpressed. CONCLUSION: The findings of this study showed a relative increase in MDR1 gene expression in response to chemotherapy and higher expression in plasmacytoid CTVTs compared with the other cytomorphologic patterns. BCL2 overexpression was related to a favorable prognosis, and p53, BAX, and BCL2 were expressed independent of the cytomorphologic CTVT type. All of the genes were expressed independent of tumor progression, as noted on histopathology.

Distribution and prevalence of transmissible venereal tumor in the Colombian canine population / Distribución y prevalencia de tumor venéreo transmisible en la población canina colombiana / Distribuição e prevalência do tumor venéreo transmissível na população canina colombiana

Abstract Background: Canine transmissible venereal tumor (CTVT) is perhaps the oldest known canine neoplasia. It is spread by cell allogeneic transplantation among susceptible animals. It is globally distributed, mainly in urban areas with high populations of stray dogs. Objective: To estimate the current distribution and prevalence of CTVT in Colombia. Methods: After analyzing the literature, we obtained epidemiological information on CTVT from 152 veterinarians in five Colombian regions via an electronic form (using Google Forms). This analysis confirmed that CTVT is endemic in the inhabited regions of Colombia and is highly prevalent in the Andean region, the most populated region in the country. Results: For the reported cases of CTVT, no significant differences were found in terms of animal gender, reproductive status, or origin. An association was found between the number of CTVT cases and concomitant infectious diseases. Results also showed that vincristine is the most effective therapy for CTVT and resistance is not a serious problem in Colombia. Conclusion: Our results confirm that CTVT is endemic in the country, coinciding with global analysis of the factors that enable the continued existence of the disease, and implies that stray dogs are the reservoir. Accordingly, we recommend that canine control policies be introduced in Colombia.

Resumen Antecedentes: el tumor venéreo transmisible canino (TVTC) es quizá la neoplasia más antigua del canino. Se transmite por un transplante alogénico entre los animales susceptibles. Su distribución es mundial, principalmente en áreas urbanas con alta población de perros callejeros. Objetivo: estimar la actual distribución y prevalencia de TVTC en Colombia. Métodos: en este estudio, además de revisar la literatura, se obtuvo información epidemiológica del TVTC de 152 veterinarios en cinco regiones de Colombia, mediante formulario electrónico (usando Google Forms). Resultados: este análisis confirma que TVTC es endémico en las regiones habitadas de Colombia y es altamente prevalente en la región Andina, la región más poblada del país. Para los casos reportados, no se encontraron diferencias significativas respecto al género de los animales afectados, su estado reproductivo o su origen. Se encontró una asociación entre los casos de TVTC y las enfermedades infecciosas concomitantes. Los resultados muestran que la vincristina es la terapia más efectiva contra el TVTC y el fenómeno de resistencia no es un problema serio en Colombia. Conclusión: los resultados confirman que el TVTC es endémico en el país lo cual coincide con el análisis global de los factores que permiten que la enfermedad continúe existiendo, e implica que los perros callejeros son el reservorio de la enfermedad. En consecuencia, se recomienda que se implementen políticas de control de caninos callejeros en Colombia.

Resumo Antecedentes: o tumor venéreo transmissível canino (TVTC) é talvez a neoplasia mais antiga dos caninos. É transmitido por um transplante alogênico entre animais susceptíveis. Sua distribuição é mundial, principalmente em áreas urbanas com altas populações de cães de rua. Objetivo: estimar a atual distribuição e prevalência de CTVT colombiano. Métodos: neste estudo, além de uma revisão da literatura, informação epidemiológica de TVTC foi obtido de 152 veterinários em cinco regiões da Colômbia, por meio de um formulário eletrônico (usando o Google Forms). Resultados: esta análise confirma que TVTC é endêmica nas regiões habitadas da Colômbia é altamente prevalente na região andina, a região mais populosa. Para os casos relatados, não houve diferenças significativas em relação ao sexo dos animais afetados, o seu estado reprodutivo nem do sua origem. Uma associação entre os casos de TVTC e doenças infecciosas concomitantes foi encontrada. Os resultados amostram que a vincristina é terapia mais eficaz contra o TVTC e o fenómeno de resistência não é um problema grave na Colômbia. Conclusão: os resultados confirmam que a TVTC é endémico no país, o qual coincide com a análise global dos fatores que permitem que a doença continue existindo e implica que os cães de rua são o reservatório da doença. Consequentemente, recomenda-se que políticas de controle sejam implementadas para cães de rua na Colômbia.

In vitro and in silico studies reveal capsid-mutant Porcine circovirus 2b with novel cytopathogenic and structural characteristics.

Porcine circovirus 2 (PCV2) is an icosahedral, non-enveloped, and single-stranded circular DNA virus that belongs to the family Circoviridae, genus Circovirus, and is responsible for a complex of different diseases defined as porcine circovirus diseases (PCVDs). These diseases - including postweaning multisystemic wasting syndrome (PMWS), enteric disease, respiratory disease, porcine dermatitis and nephropathy syndrome (PDNS), and reproductive failure - are responsible for large economic losses in the pig industry. After serial passages in swine testicle (ST) cells of a wild-type virus isolated from an animal with PMWS, we identified three PCV2b viruses with capsid protein (known as Cap protein) cumulative mutations, including two novel mutants. The mutant viruses were introduced into new ST cell cultures for reisolation and showed, in comparison to the wild-type PCV2b, remarkable viral replication efficiency (> 1011 DNA copies/ml) and cell death via necrosis, which were clearly related to the accretion of capsid protein mutations. The analysis of a Cap protein/capsid model showed that the mutated residues were located in solvent-accessible positions on the external PCV2b surface. Additionally, the mutated residues were found in linear epitopes and participated in pockets on the capsid surface, indicating that these residues could also be involved in antibody recognition. Taking into account the likely natural emergence of PCV2b variants, it is possible to consider that the results of this work increase knowledge of Circovirus biology and could help to prevent future serious cases of vaccine failure that could lead to heavy losses to the swine industry.

Clinical prognosis and biological factors associated with survival in canines affected by breast neoplasms / Pronóstico clínico y factores biológicos asociados a la supervivencia en caninos afectados por neoplasias mamarias / Prognóstico clínico e fatores biológicos associados a supervivência em caninos afetados por neoplasias mamarias

Introduction: After the skin, breast glands are the location most commonly affected by tumors in bitches. Objectives: to evaluate the survival rate in canines affected by breast neoplasms submitted to surgery, relating the histopathological diagnosis with clinical factors of prognosis. Methodology: 52 bitches were included. The treatment established included mastectomy, previous blood and chest radiographic analysis in order to rule out metastasis. In 13 individuals, euthanasia was performed due to the advanced state of the disease. The variables analyzed were: frequency of presentation, age, reproductive history, diet, previous hormonal treatment, clinical stage, recurrence and survival. Statistical analysis of the variables was performed through analysis of variance and contingency tables based on chi-square tests (Χ²). Results: The effect of type of diagnosis on survival, age and pseudopregnancy showed significant differences (p<0.05). Opposite to this, no significant differences of the type of diagnosis on hormonal treatment, diet, early neutering and recurrence were observed. Conclusions: the determinant prognostic factor on survival was tumoral histopathological pattern (type of diagnosis). Animals with pseudopregnancy showed a higher susceptibility to suffer breast neoplasms. Benign tumors were observed in later ages than malignant.

Introducción: después de la piel, las glándulas mamarias son el sitio más común de afectación tumoral en las perras. Objetivos: evaluar la supervivencia en caninos afectados por neoplasias de la glándula mamaria que fueron sometidos a cirugía, relacionando el diagnóstico histopatológico con factores clínicos de pronóstico. Metodología: se incluyeron 52 perras. El tratamiento instaurado fue mastectomía, previo análisis sanguíneo y radiográfico del tórax con el fin de descartar metástasis. En 13 individuos se realizó la eutanasia debido al avanzado estado de la enfermedad. Las variables analizadas fueron: frecuencia de presentación, edad, historia reproductiva, dieta, tratamientos hormonales previos, estadificación clínica, recidivas y supervivencia. El análisis estadístico de las variables se realizó mediante el análisis de varianza y tablas de contingencia asociadas a la prueba de chi cuadrado (Χ²). Resultados: El efecto del tipo de diagnóstico sobre las variables supervivencia, edad y pseudogestación evidenciaron diferencias significativas (p<0,05), contrario a esto, no se encontraron diferencias significativas en el tipo de diagnóstico para las variables tratamiento hormonal, dieta, esterilización temprana y recidivas. Conclusiones: el factor pronóstico determinante en la sobrevida fue el patrón histopatológico tumoral (tipo de diagnóstico), los animales con pseudogestación evidenciaron una mayor susceptibilidad a padecer cáncer mamario. Los tumores benignos se manifestaron en edades más tardías que los malignos.

Introdução: depois da pele, as glâdulas mamarias são o sitio mais comum de afetação tumoral nas cadelas. Objetivo: avaliar a supervivência em cadelas afetados por neoplasias na glândula mamaria e que foram submetidas a cirurgia, relacionando além o diagnóstico histopatológico com fatores clínicos de prognóstico. Metodologia: incluíramse 52 cadelas. O tratamento instaurado foi mastectomia, prévio analise sanguíneo e radiográfico do tórax com o fim de descartar metástase. Em 13 indivíduos realizou-se a eutanásia devido ao avançado estado da doença. As variáveis analisadas foram: frequência de apresentação, idade, história reprodutiva, dieta, tratamentos hormonais prévios, estadificação clínica, recidiva e sobrevivência. O analise estatístico das variáveis realizou-se mediante o analise de variância e tabelas de contingência associadas ao teste chi quadrado (X2). Resultados: O efeito do tipo de diagnóstico sobre as variáveis supervivência, idade e pseudogestação evidenciaram diferenças significativas (p<0.05), contrário a isto, não se encontraram diferenças significativas no tipo de diagnostico para as variáveis tratamento hormonal, dieta, esterilização juvenil e recidivas. Conclusões: o fator prognóstico determinante na sobrevida foi o padrão histopatológico tumoral (tipo de diagnostico), os animais com pseudogestação evidenciaram uma maior susceptibilidade a padecer câncer mamário. Os tumores benignos manifestaram-se em idades mais tardias que os malignos.

Uso de la inmunohistoquímica como herramienta epidemiológica para el diagnóstico de rabia bovina a partir de casos no conclusivos / Use of immunohistochemistry as an epidemiological tool for the diagnosis of bovine rabies using inconclusive cases

Objetivo. Identificar el virus de la rabia en casos de encefalitis bovina a partir de muestras archivadas en el laboratorio sin diagnóstico conclusivo. Materiales y métodos. Doce muestras de cerebro bovino sospechosas de rabia, fueron procesadas por la técnica de inmunoperoxidasa indirecta, usando anticuerpos policlonales contra el agente viral. Resultados. Se demostró la presencia de antígenos virales en tres casos en forma de agregados pequeños en el citoplasma de las neuronas, con un patrón de forma redonda u oval y un número variable de corpúsculos de inclusión viral. Se discute sobre la importancia de los resultados en Colombia, la utilidad de la técnica en las difíciles condiciones de envío de muestras al laboratorio, además la posible relación de los casos negativos con herpesvirus bovino 5. Conclusiones. La utilización de la técnica de inmunohistoquímica para demostrar antígenos del virus rábico en encéfalos bovinos fijados en formol, puede ayudar en el perfeccionamiento del mapa epidemiológico de la enfermedad de la rabia en Colombia y puede disminuir el alto subdiagnóstico de otras enfermedades que afectan el sistema nervioso de los bovinos.

Objective. Identify the rabies virus in cases of nervous disease archived in the laboratory with diagnosis of nonspecific encephalitis. Materials and methods. Twelve samples of bovine brain suspected of rabies, were processed by indirect immunoperoxidase technique using polyclonal antibodies against the viral agent. Results. Was demonstrated the presence of viral antigens in three cases in the form of small aggregates in the cytoplasm of neurons, with a pattern of round or oval and a variable number of viral inclusion bodies. We discussed the importance of the results in Colombia, the usefulness of the technique in the difficult conditions for sending samples to the laboratory, plus the possible relationship of the negative cases with bovine herpesvirus 5. Conclusions. The use of immunohistochemical technique to demonstrate rabies virus antigens in formalin fixed bovines tissues can help in the construction of an epidemiological map of rabies disease in Colombia and may reduce the high under-diagnosis of diseases of the nervous system of cattle, reported in some regions.

Immunohistochemical and morphological features of a small bowel leiomyoma in a black crested macaque (Macaca nigra).

BACKGROUND: Spontaneous gastrointestinal neoplasms in non-human primates are commonly seen in aged individuals. Due to genetic similarities between human and non-human primates, scientists have shown increasing interest in terms of comparative oncology studies. CASE PRESENTATION: The present study is related to a case of an intestinal leiomyoma in a black crested macaque (Macaca nigra), kept on captivity by Matecaña Zoo, Pereira City, Colombia. The animal had abdominal distension, anorexia, vomiting, diarrhea and behavioral changes. Clinical examination showed an increased volume in the upper right abdominal quadrant caused by a neoplastic mass. The patient died during the surgical procedure. Necropsy revealed several small nodules in the peritoneum with adhesion to different portions of the small and large intestines, liver, stomach and diaphragm. Tissue samples were collected, routinely processed and stained by H&E. Microscopic examination revealed a mesenchymal tumor limited to tunica muscularis, resembling normal smooth muscle cells. Neoplastic cells were positive for alpha-smooth muscle actin and vimentin, and negative for cytokeratin AE1/AE3 by immunohistochemistry. Those morphological and immunohistochemical findings allowed to diagnose the intestinal leiomyoma referred above. CONCLUSION: Neoplastic diseases in primates have multifaceted causes. Their manifestations are understudied, leading to a greater difficulty in detection and measurement of the real impact provides by this disease.