Cryopreservation of canine ovarian tissue by slow freezing and vitrification: Evaluation of follicular morphology and apoptosis rate.

In this study, we aimed to evaluate the efficacy of cryopreserving canine ovarian tissue using vitrification and slow freezing methods while investigating potential differences in cryotolerance based on follicular type and cryopreservation technique. Twenty-eight ovaries were collected from 14 anoestrus bitches of various breeds, aged between 2 and 5 years, and undergoing elective ovariohysterectomy. The ovaries were sectioned into small fragments and randomly assigned to three groups: vitrification, slow freezing, and a control group (fresh tissue). Vitrification was performed using cryotubes containing DAP 213 solution (2M DMSO, 1M acetamide, 3M propylene glycol) in two stages, while slow freezing involved cryotubes with 1.5M DMSO solution inserted into a programmable machine. The effects of cryopreservation were evaluated by histology and immunohistochemistry (cleaved caspase-3), to determine the percentage of cells undergoing apoptosis. Histological examination revealed that the slow freezing group exhibited a significantly higher percentage of intact follicles (45.75 %) compared to those subjected to vitrification (38.17 %; P = 0.01). Immunohistochemical evaluation further indicated that 84.21 % of the follicles in the slow freezing group did not express caspase-3, suggesting the absence of apoptosis. Conversely, vitrified samples exhibited significantly more apoptotic cells compared to other groups (P < 0.001). Furthermore, early antral follicles displayed a higher susceptibility to degeneration regardless of the cryopreservation method employed. Nevertheless, when comparing the cryopreserved groups, early antral follicles showed greater degeneration in slow freezing group, while preantral follicles were the most affected in the vitrification group. In conclusion, slow freezing demonstrated superior preservation of viable follicles compared to vitrification and emerged as the preferred technique for cryopreserving canine ovarian tissue. These findings contribute valuable insights into optimizing cryopreservation methods for canine ovarian tissue, potentially benefiting reproductive technologies and fertility preservation in canines.

Contextual Hospital Conditions and the Risk of Nosocomial SARS-CoV-2 Infection: A Matched Case-Control Study with Density Sampling in a Large Portuguese Hospital.

Objective: Knowledge of the role of hospital conditions in SARS-CoV-2 transmission should inform strategies for the prevention of nosocomial spread of this pathogen and of similarly transmitted viruses. This study aimed to identify risk factors for nosocomial acquisition of SARS-CoV-2. Methods: We ran a nested case-control study with incidence density sampling among adult patients hospitalized for >7 days (August-December 2020). Patients testing positive for SARS-CoV-2 after the 7th day of hospitalization were defined as cases and matched with controls (1:4) by date of admission, hospitalization duration until index date, and type of department. Individual and contextual characteristics were gathered, including admission characteristics and exposures during the risk period. Conditional logistic regression was used to estimate the odds ratios (ORs) with respective 95% confidence intervals (CI) separately for probable (diagnosed on day 8-13) and definitive (diagnosed after day 14) nosocomial sets. Results: We identified 65 cases (31 probable; 34 definitive) and 219 controls. No individual characteristic was related to nosocomial acquisition of SARS-CoV-2. Contextual risk factors for nosocomial acquisition were staying in a non-refurbished room (probable nosocomial: OR = 3.6, 1.18-10.87), contact with roommates with newly diagnosed SARS-CoV-2 (probable nosocomial: OR = 9.9, 2.11-46.55; definitive nosocomial: OR = 3.4, 1.09-10.30), and contact with roommates with a first positive test 21-90 days before the beginning of contact (probable nosocomial: OR = 10.7, 1.97-57.7). Conclusions: Hospital conditions and contact with recently infected patients modulated nosocomial SARS-CoV-2 transmission. These results alert us to the importance of the physical context and of agile screening procedures to shorten contact with patients with recent infection.

Immunohistochemistry Screening of Different Tyrosine Kinase Receptors in Canine Solid Tumors-Part I: Proposal of a Receptor Panel to Predict Therapies.

The use of tyrosine kinase inhibitors (TKI) has been growing in veterinary oncology and in the past few years several TKI have been tested in dogs. However, different from human medicine, we lack strategies to select patients to be treated with each TKI. Therefore, this study aimed to screen different tumor subtypes regarding TKI target immunoexpression as a predictor strategy to personalize the canine cancer treatment. It included 18 prostatic carcinomas, 36 soft tissue sarcomas, 20 mammary gland tumors, 6 urothelial bladder carcinomas, and 7 tumors from the endocrine system. A total of 87 patients with paraffin blocks were used to perform immunohistochemistry (IHC) of human epidermal growth factor receptor 2 (HER-2), epidermal growth factor receptors 1 (EGFR1), vascular endothelial growth factor receptor 2 (VEGFR-2), platelet derived growth factor receptor beta (PDGFR-ß), c-KIT, and extracellular signal-regulated kinase 1/2 (ERK1/ERK2). The immunohistochemical screening revealed a heterogeneous protein expression among histological types with mesenchymal tumors showing the lowest expression level and carcinomas the highest expression. We have demonstrated by IHC screening that HER2, EGFR1, VEGFR-2, PDGFR-ß and ERK1/ERK2 are commonly overexpressed in dogs with different carcinomas, and KIT expression is considered relatively low in the analyzed samples.

Maintenance of postharvest quality of 'Palmer' mango coated with biodegradable coatings based on cassava starch and emulsion of lemongrass essential oil.

This study aimed to evaluate the effect of applying oxidized cassava starch-based edible coatings with addition of lemongrass essential oil emulsion on 'Palmer' mangoes stored under refrigeration. A completely randomized design was used, arranged in a 5 × 3 factorial scheme, with five types of coatings and three evaluation times. The evaluated postharvest quality parameters consisted of weight loss, pulp and peel firmness, biochemical transformations related to pigments, and pulp and peel coloration of mango. The application of edible coatings with a 0.9 % EO concentration resulted in delayed fruit ripening, evidenced mainly by a 7.25 % reduction in weight loss, a 29.23 % increase in soluble solids content, and a 24.15 % decrease in total chlorophyll, when compared to uncoated fruits, which showed 19.8 %, 48.66 %, and 82.00 %, respectively, over the storage period. This effect was also evident in the angle Hue (°h) measurement, with uncoated fruits showing a decrease of 32.2 %. The antimicrobial effect and absence of anthracnose symptoms were observed in the fruits in which the coating with 0.9 % EO was applied. Therefore, biodegradable coating with the addition of 0.9 % emulsion EO, can be used as postharvest treatments for maintenance quality of 'Palmer' mangoes during refrigerated storage.

Transcriptomic analysis of mouse TRAMP cell lines and tumors provide insights into shared pathways and therapeutic targets.

The present study focused on comparing the gene expression profiles of different mouse models of prostate cancer, focusing on the TRAMP transgenic model and its derived cell lines and extending the comparisons to relevant genetically engineered mouse models and human prostate cancer datasets. Employing RNA sequencing, we examined different levels of prostate cancer aggressiveness from the original TRAMP cells to the TRAMP-C2 (TC2) derived cell line and extending to the aggressive TC2-Ras (TC2R) cells and tumors. TC2R acquire the ability to grow in bone tissue upon implantation, unlike the parental TC2 cells. Analysis identified upregulated genes in cell cycle regulation, immune response, and mitotic processes in TRAMP compared to wild-type tissues. TC2 cells exhibited unique gene profiles enriched in ECM organization and tissue development pathways, while TC2R cells showed increased cytokine signaling and motility genes, with decreased ECM and immune response pathways. In vivo TC2R models demonstrated enhanced ECM organization and receptor tyrosine kinase signaling in tumors, notably enriching immune processes and collagen degradation pathways in intratibial tumors. Comparative analysis among mouse and human datasets showed overlaps, particularly in pathways relating to mitotic cycle regulation, ECM organization, and immune interactions. A gene signature identified in TC2R tumors correlated with aggressive tumor behavior and poor survival in human datasets. Further immune cell landscape analysis of TC2R tumors revealed altered T cell subsets and macrophages, confirmed in single-cell RNA-seq from human samples. TC2R models thus hold significant promise in helping advance preclinical therapeutics, potentially contributing to improved prostate cancer patient outcomes.

Canine primary ureteral leiomyosarcoma treated with unilateral left ureteronephrectomy.

Background: Primary ureteral neoplasms are extremely rare in dogs, and ureteral involvement usually occurs owing to the invasion of renal and bladder tumors. Case Description: This case report describes a 12-year-old intact male mixed-breed dog referred to a private clinic with a six-month history of abdominal distention. A physical examination revealed mild abdominal pain. Hematological tests detected normocytic-normochromic anemia (hematocrit 33.6% [reference interval-RI: 37%-55%], red blood cells 4.93 M/µl [RI: 5.5-8.5 M/µl], and hemoglobin 12.4 g/dl [RI: 12-18.0 g/dl]). The results from the leukogram, thrombogram, renal, and hepatic panels were within the reference intervals for dogs. Abdominal ultrasonography revealed a cavitary mass measuring approximately 12 cm in diameter as the largest tumor in the left abdominal region over the left hepatic lobe or mesenteric site. Chest radiography did not reveal any metastasis. Therefore, the patient underwent exploratory laparotomy, during which the left ureter was found to be affected by a 12-cm mass that adhered to the left kidney. A unilateral left ureteronephrectomy was performed, and histology and immunohistochemistry (IHC) confirmed well-differentiated primary ureteral leiomyosarcoma. The patient survived for 130 days but died of lung metastasis. Conclusion: Ureteral leiomyosarcoma should be investigated and included in the list of differential diagnoses for primary ureteral neoplasms. Regardless of the therapeutic modality, the prognosis of ureteral leiomyosarcoma may be unfavorable, as shown in this report.

Analysis of VEGFR-2 and PDGFR-ß expression in canine splenic hemangiosarcoma to identify drug repositioning candidates.

Splenic tumors are very common in dogs, and canine hemangiosarcoma (HSA) is one of the most important malignant splenic tumors. Surgery followed by chemotherapy (anthracycline-based protocols) is recommended for treating canine HSA; however, patients still do not achieve long-term survival. Therefore, this research aimed to assess vascular endothelial growth factor receptor-2 (VEGFR-2) and platelet-derived growth factor receptor-ß (PDGFR-ß) gene expression in formalin-fixed tissues, evaluate the quality of mRNA for quantitative polymerase chain reaction (qPCR) analysis and identify drug repositioning candidates based on VEGFR-2 and PDGFR-ß. qPCR analysis identified the relative expression of heterogeneous VEGFR-2 and PDGFR-ß, with samples showing no transcripts or very low expression and those with higher relative quantification for both genes. We then used immunohistochemistry to correlate the relative quantification of VEGFR-2 and PDGFR-ß transcripts with respective higher protein expression to validate our results. In the next step, we evaluated drug repositioning candidates and identified small molecule inhibitors (i.e. sorafenib) and natural compounds (curcumin and resveratrol) with the ability to block VEGFR-2 and PDGFR-ß genes. Overall, our results indicated that VEGFR-2 and PDGFR-ß expression is highly variable among canine HSA samples and different drugs can block the expression of both genes. Therefore, a personalized approach could be useful for selecting anti-VEGFR-2 and PDGFR-ß therapies and both genes are potential candidates for future oncological panels.

Os tumores esplênicos são muito comuns em cães, e o hemangiosarcoma (HSA) é um dos tumores esplênicos malignos mais importantes em cães. A cirurgia seguida de quimioterapia (protocolos baseados em antraciclinas) é a abordagem terapêutica mais recomendada para o tratamento da HSA canino; no entanto, os pacientes ainda não alcançam longa sobrevida após tratamento. Portanto, esta pesquisa teve como objetivo avaliar a expressão do receptor do fator de crescimento endotelial vascular-2 (VEGFR-2) e do receptor do fator de crescimento derivado de plaquetas-ß (PDGFR-ß) em tecidos fixados em formalina e identificar candidatos ao reposicionamento de medicamentos baseado na expressão desses genes. A análise qPCR identificou a expressão relativa heterogênea de VEGFR-2 e PDGFR-ß, com amostras sem transcritos ou com expressão muito baixa ou amostras com alta quantificação relativa para ambos os genes. Em seguida, foi realizada o exame imuno-histoquímico para correlacionar a quantificação relativa dos transcritos de VEGFR-2 e PDGFR-ß com a respectiva maior expressão proteica para validar nossos resultados. Na próxima etapa, avaliamos candidatos ao reposicionamento de medicamentos e identificamos inibidores de moléculas pequenas (ou seja, sorafenibe) e compostos naturais (curcumina e resveratrol) com capacidade de bloquear os genes VEGFR-2 e PDGFR-ß. No geral, nossos resultados indicaram que a expressão de VEGFR-2 e PDGFR-ß é altamente variável entre amostras caninas de HSA e diferentes drogas podem bloquear a expressão de ambos os genes. Portanto, uma abordagem personalizada poderia ser útil para selecionar terapias anti-VEGFR-2 e PDGFR-ß e ambos os genes são potenciais candidatos para futuros painéis oncológicos.

Immunostaining and gene expression of epidermal growth factor receptors (HER1/HER2) in canine cutaneous squamous cell carcinoma.

Cutaneous squamous cell carcinoma (cSCC) is a neoplasm type often diagnosed in dogs. However, studies focused on further investigating its molecular biology, mainly biomarkers to help implementing new therapies, remain scare in the literature. Thus, immunostaining and the gene expression of epidermal growth factor receptors (HER1 and HER2) in canine cSCC presenting different cell differentiation degrees were herein assessed. Thirty-two (32) canine cSCC were selected, classified based on to their cell differentiation degree and subjected to immunohistochemical study to assess HER1 and HER2 immunostaining intensity and distribution. In addition, HER1 and HER2 gene expression was investigated through real-time PCR. Membranous and cytoplasmic immunostaining were observed in both markers. HER2 prevailed in poorly differentiated cSCC; there was positive protein expression correlation between both markers. Mean HER1 gene expression was higher in moderately differentiated, whereas mean HER2 gene expression was higher in poorly differentiated cSCC. Moreover, there was gene expression correlation between markers, regardless of cell differentiation degree. Thus, HER2 protein immunostaining and gene expression were higher in poorly differentiated canine cSCC and it enabled understanding that increase observed in this epidermal growth factor receptor is proportional to this neoplasm's cell differentiation degree in canine species. Results in the current study helped better understanding canine cSCC's molecular biology; however, it is relevant studying other markers aiming to investigate signaling pathways.

Serum Extracellular Vesicles Cargo Approach in Bitches with Mammary Tumors.

This study investigated serum extracellular vesicles (EVs) in bitches with mammary neoplasms, in order to understand their size, shape, and concentration, as well as their association with tumor malignancy. Thirty bitches were categorized into control (n = 10), mammary tumor grades I and II (GI, n = 13), and grade III (GII, n = 7). Serum was separated from blood collected during mastectomy, and EVs were isolated using size exclusion chromatography. The analysis revealed no significant differences in EV concentrations among groups, with similar concentrations for control, GI, and GII. Ninety-one proteins were identified in EV-enriched samples, with six showing varied abundance across groups. Notably, keratin 18 was highly abundant in GI, while sushi domain-containing protein, EvC ciliary subunit 2, and the joining chain of multimeric IgM and IgA were increased in GII. Additionally, protocadherin 17 and albumin were upregulated in both GI and GII. ROC curves identified potential biomarkers for differentiating tumor grades. Enrichment pathway analysis revealed AFP gene upregulation in the GI. Mass spectrometry proteomics data were deposited in Mendeley Data. The study provides valuable insights into serum EV characterization in bitches, suggesting keratin 18 and protocadherin 17 as potential biomarkers for canine mammary neoplasia, with implications for future diagnostic and therapeutic strategies.

A Second Wind for Inorganic APIs: Leishmanicidal and Antileukemic Activity of Hydrated Bismuth Oxide Nanoparticles.

American cutaneous leishmaniasis is a disease caused by protozoa of the genus Leishmania. Currently, meglumine antimoniate is the first-choice treatment for the disease. The limited efficacy and high toxicity of the drug results in the necessity to search for new active principles. Nanotechnology is gaining importance in the field, since it can provide better efficacy and lower toxicity of the drugs. The present study aimed to synthesize, characterize, and evaluate the in vitro leishmanicidal and antileukemic activity of bismuth nanoparticles (BiNPs). Promastigotes and amastigotes of L. (V.) guyanensis and L. (L.) amazonensis were exposed to BiNPs. The efficacy of the nanoparticles was determined by measurement of the parasite viability and the percentage of infected cells, while the cytotoxicity was characterized by the colorimetry. BiNPs did not induce cytotoxicity in murine peritoneal macrophages and showed better efficacy in inhibiting promastigotes (IC50 < 0.46 nM) and amastigotes of L. (L.) amazonensis. This is the first report on the leishmanicidal activity of Bi-based materials against L. (V.) guayanensis. BiNPs demonstrated significant cytotoxic activity against K562 and HL60 cells at all evaluated concentrations. While the nanoparticles also showed some cytotoxicity towards non-cancerous Vero cells, the effect was much lower compared to that on cancer cells. Treatment with BiNPs also had a significant effect on inhibiting and reducing colony formation in HL60 cells. These results indicate that bismuth nanoparticles have the potential for an inhibitory effect on the clonal expansion of cancer cells.

Assessing proteases and enzymes of the trypanothione system in subpopulations of Leishmania (Viannia) braziliensis Thor strain during macrophage infection.

BACKGROUND: Leishmania (Viannia) braziliensis Thor strain exhibits a heterogeneous composition comprised of subpopulations with varying levels of infectivity. Clonal subpopulations were previously obtained from the strain Thor by sorting single-parasites and proceeding cultivation. The subpopulations used in this study are named Thor03, Thor 10 and Thor22. OBJECTIVES: Phenotypic characteristics of the parasite, specially focusing on virulence factors and resistance to the antimicrobial mechanisms of macrophages, were investigate in these subpopulations. METHODS: Cellular and molecular biology, as well as biochemistry approaches were applied to obtain the data analysed in this study. FINDINGS: Relative quantification of gene expression was measured for calpain, cysteine protease B (CPB), and subtilisin proteases but no significant differences in these genes' expression among subpopulations was observed. However, subtilisin and CPB proteins were assessed as more abundant in Thor03 by fluorescence-labelled flow cytometry technique. Western Blotting assays, as semi-quantitative analysis in gel, showed higher concentrations of subtilisin (110 to 50 kDa) and CPB (40 to 18 kDa) in extract of intracellular amastigotes from subpopulations Thor03 and Thor10 and calpain (60 to 25 kDa) showed no significant differences among subpopulations. Complementary, higher trypanothione reductase activity was observed in Thor10 intracellular amastigotes and assays of susceptibility to hydrogen peroxide-inducing agents and nitric oxide donors conducted with promastigotes revealed greater resistance to in vitro oxidative stress induction for Thor10, followed by Thor03. MAIN CONCLUSIONS: The data obtained for the virulence factors explored here suggest how multiple coexisting phenotypic-distinct subpopulations may contribute in adaptability of a single L. (V.) braziliensis strain during infection in the host cells.

Relationship Between Chronic Obstructive Pulmonary Disease and Osteoporosis: A Scoping Review.

INTRODUCTION: Potential associations between Chronic Obstructive Pulmonary Disease (COPD) and osteoporosis have been studied, but areas of uncertainty remain. OBJECTIVE: This scoping review aimed to identify the published evidence on the epidemiological relationships between COPD and osteoporosis. METHODS: Experimental and observational evidence evaluating relationships between COPD and osteoporosis on epidemiology, clinical manifestations, risk factors (RFs), therapeutic management and quality of life (QoL) was searched on PubMed and Embase (until May 2023). The studies were categorized according to their objectives and characteristics. Data were analyzed using descriptive statistics. RESULTS: Ninety-nine studies were selected, namely 33 (33%) reporting epidemiologic measures, 11 (11%) clinical manifestations, 74 (75%) RFs (45 ones, of which body mass index [BMI; n = 22 studies], corticosteroids' use [n = 20], and COPD severity [n = 15] were the most studied), 7 (7%) therapeutic management, and 3 (3%) QoL. Twenty-seven (27.6%) studies evaluated ≥2 domains. Most studies followed a cross-sectional design (n = 37; 37.4%). Eighty-nine studies (90%) assessed patients with COPD at baseline and studied its relationship with osteoporosis. CONCLUSION: There are well-established features linking COPD and osteoporosis, including shared RFs, such as smoking, elderly, physical inactivity, or low BMI. Others deserve clarification, including the impact of COPD severity, or the use of inhaled corticosteroids on the incidence of osteoporosis and fractures, as well as the value of performing routine imaging tests, or prescribing anti-resorptive medications in COPD to prevent osteoporotic-related outcomes. QoL studies are also lacking. Investigating such issues is needed to propose clinical guidelines for managing osteoporosis in patients with COPD.

Immunomodulatory and Anticancer Effects of Fridericia chica Extract-Loaded Nanocapsules in Myeloid Leukemia.

Nanocapsules provide selective delivery and increase the bioavailability of bioactive compounds. In this study, we examined the anticancer and immunomodulatory potential of Fridericia chica (crajiru) extract encapsulated in nanocapsules targeting myeloid leukemias. Nanocapsules containing crajiru (nanocapsules-CRJ) were prepared via interfacial polymer deposition and solvent displacement. Size and polydispersity were measured by dynamic light scattering. Biological assays were performed on leukemia cell lines HL60 and K562 and on non-cancerous Vero cells and human PBMC. The anticancer activity was evaluated using cytotoxicity and clonogenic assays, while the immunomodulatory activity was evaluated by measuring the levels of pro- and anti-inflammatory cytokines in PBMC supernatants treated with concentrations of nanocapsules-CRJ. Nanocapsules-CRJ exhibited significant cytotoxic activity against HL60 and K562 cells at concentrations ranging from 0.75 to 50 µg/mL, with the greatest reductions in cell viability observed at 50 µg/mL (p < 0.001 for HL60; p < 0.01 for K562), while not affecting non-cancerous Vero cells and human PBMCs. At concentrations of 25 µg/mL and 50 µg/mL, nanocapsules-CRJ reduced the formation of HL60 and K562 colonies by more than 90% (p < 0.0001). Additionally, at a concentration of 12 µg/mL, nanocapsules-CRJ induced the production of the cytokines IL-6 (p = 0.0002), IL-10 (p = 0.0005), IL-12 (p = 0.001), and TNF-α (p = 0.005), indicating their immunomodulatory potential. These findings suggest that nanocapsules-CRJ hold promise as a potential therapeutic agent with both cytotoxic and immunomodulatory properties.

Review of the comparative pathological and immunohistochemical features of human and canine cutaneous melanocytic neoplasms.

Melanocytic neoplasms originate from melanocytes and melanoma, the malignant form, is a common canine neoplasm and the most aggressive human skin cancer. Despite many similarities between these neoplasms in both species, only a limited number of studies have approached these entities in a comparative manner. Therefore, this review compares benign and malignant melanocytic neoplasms in dogs and humans, exclusively those arising in the haired skin, with regard to their clinicopathological, immunohistochemical and molecular aspects. Shared features include spontaneous occurrence, macroscopic features and microscopic findings when comparing human skin melanoma in the advanced/invasive stage and canine cutaneous melanoma, immunohistochemical markers and several histopathological prognostic factors. Differences include the apparent absence of active mutations in the BRAF gene in canine cutaneous melanoma and less aggressive clinical behaviour in dogs than in humans. Further studies are required to elucidate the aetiology and genetic development pathways of canine cutaneous melanocytic neoplasms. Evaluation of the applicability of histopathological prognostic parameters commonly used in humans for dogs are also needed. The similarities between the species and the recent findings regarding genetic mutations in canine cutaneous melanomas suggest the potential utility of dogs as a natural model for human melanomas that are not related to ultraviolet radiation.

Lapatinib antitumor effect is associated with PI3K and MAPK pathway: An analysis in human and canine prostate cancer cells.

The aberrant activation of HER2 has a pivotal role in bone metastasis implantation and progression in several tumor types, including prostate cancer (PC). Trastuzumab and other anti-HER2 therapies, such as lapatinib, have been used in human breast cancer HER2 positive. Although HER2 overexpression has been reported in PC, anti-HER2 therapy response has revealed conflicting results. We investigated the potential of lapatinib in inhibiting cell migration and inducing apoptosis in two human (LNCaP and PC3) and two canine PC cell lines (PC1 and PC2). Cell migration and apoptosis were evaluated by Annexin V/PI analysis after lapatinib treatment. The transcriptome analysis of all cell lines before and after treatment with lapatinib was also performed. We found increased apoptosis and migration inhibition in LNCaP cells (androgen-sensitive cell line), while PC1, PC2, and PC3 cells showed no alterations after the treatment. The transcriptome analysis of LNCaP and PC3 cell lines showed 158 dysregulated transcripts in common, while PC1 and PC2 cell lines presented 82. At the doses of lapatinib used, we observed transcriptional modifications in all cell lines. PI3K/AKT/mTOR pathway were enriched in human PC cells, while canine PC cells showed enrichment of tyrosine kinase antitumor response and HER2-related pathways. In canine PC cells, the apoptosis failed after lapatinib treatment, possibly due to the downregulation of MAPK genes. Prostate cancer cells insensitive to androgens may be resistant to lapatinib through PI3K gene dysregulation. The association of lapatinib with PI3K inhibitors may provide a more effective antitumor response and clinical benefits to PC patients.

Calibration system correction factor for measuring the reference air kerma rate (RAKR) applied to high dose rate192Ir sources (HDR).

The aim of this study was to use computer simulation to analyze the impact of the aluminum fixing support on the Reference Air Kerma (RAK), a physical quantity obtained in a calibration system that was experimentally developed in the Laboratory of Radiological Sciences of the University of the State of Rio de Janeiro (LCR-UERJ). Correction factors due to scattered radiation and the geometry of the192Ir sources were also sought to be determined. The computational simulation was validated by comparing some parameters of the experimental results with the computational results. These parameters were: verification of the inverse square law of distance, determination of (RAKR), analysis of the source spectrum with and without encapsulation, and the sensitivity curve of the Sourcecheck 4PI ionization chamber response, as a function of the distance from the source along the axial axis, using the microSelectron-v2 (mSv2) and GammaMedplus (GMp) sources. Kerma was determined by activity in the Reference air, with calculated values of 1.725 × 10-3U. Bq-1and 1.710 × 10-3U. Bq-1for the ionization chamber NE 2571 and TN 30001, respectively. The expanded uncertainty for these values was 0.932% and 0.919%, respectively, for a coverage factor (k = 2). The correction factor due to the influence of the aluminum fixing support for measurements at 1 cm and 10 cm from the source was 0.978 and 0.969, respectively. The geometric correction factor of the sources was ksg= 1.005 with an expanded uncertainty of 0.7% for a coverage factor (k = 2). This value has a difference of approximately 0.2% compared to the experimental values.

Cytotoxic effects of crotoxin from Crotalus durissus terrificus snake in canine mammary tumor cell lines.

Background: Mammary gland tumors are the most prevalent neoplasm in intact female dogs, and they are good natural models to study comparative oncology. Most canine mammary malignancies, as in women, are commonly refractory to conventional therapies and demand continuous new therapeutic approaches. Crotalus durissus terrificus, also called rattlesnake, has more than 60 different proteins in its venom with multiple pharmaceutical uses, such as antitumor, antiviral, and antimicrobial action. Crotoxin, a potent ß-neurotoxin formed by the junction of two subunits, a basic subunit (CB-PLA2) and an acidic subunit (crotapotin), has already been reported to have anticancer properties in different types of cancers. Methods: In this work, we describe the cytotoxic potential of crotoxin and its subunits compared to doxorubicin (drug of choice) in two canine mammary carcinoma cell lines. Results: Crotoxin, CB-PLA2, crotalic venom, and doxorubicin decreased cell viability and the ability to migrate in a dose-dependent manner, and crotapotin did not present an antitumoral effect. For all compounds, the predominant cell death mechanism was apoptosis. In addition, crotoxin did not show toxicity in normal canine mammary gland cells. Conclusion: Therefore, this work showed that crotoxin and CB-PLA2 had cytotoxic activity, migration inhibition, and pro-apoptotic potential in canine mammary gland carcinoma cell lines, making their possible use in cancer research.

Background and common lesions in the female reproductive organs of giant anteaters (Myrmecophaga tridactyla).

The giant anteater (Myrmecophaga tridactyla) is a vulnerable species in South America and is considered endangered or near extinction in Central America. Therefore, studies describing the reproductive characteristics of this species are pivotal for its conservation. Thus, this study aimed to provide a morphological description of the female reproductive tissues of this species. We collected tissue samples from six female giant anteaters and performed gross, morphological, and histochemical analyses. Five adult subjects and one juvenile were included in the study. In the ovary, classifications were made according to the follicle and oocyte sizes: primordial, primary, secondary, early antral, or antral. Typical follicles with a single oocyte surrounded by a simple or stratified layer of cubic epithelium, atretic follicles, corpora lutea, corpora albicans, and ovarian cysts were also observed. No ovarian lesions were observed. By contrast, endometritis, metritis, mucometra, and endometrial cysts were identified in the uterus. Uterine alterations in these subjects were frequent and could affect reproduction.