Search Results (46)

As the body of knowledge on feline mammary tumors (FMTs) continues to grow, their histological classification and grading systems have undergone revisions and updates to better reflect the biological behavior of these tumors. In this review, the historical evolution of these frameworks is traced and later revisited in the context of their prognostic relevance. Numerous studies have investigated clinicopathological prognostic factors in feline mammary carcinomas (FMCs); however, the heterogeneity in assessment methods, inclusion criteria for survival analysis, and the clinical endpoints considered can often complicate direct comparisons across different studies and may contribute to seemingly conflicting results. Furthermore, the small cohort size of many studies limits the robustness and transferability of their findings. This paper provides an updated overview of the epidemiological, clinical, and pathological prognostic factors of these tumors, while also highlighting current challenges, methodological limitations, and areas for future improvement. Full article

Feline mammary carcinoma (FMC) exhibits aggressive behavior, with limited treatment options. Given the relevance of the PD-1/PD-L1/PD-L2 axis in human breast cancer immunotherapy, this study assessed PD-1 and its ligands in rare FMC histotypes (n = 48) using immunohistochemistry on tumor cells (TCs), intratumoral lymphocytes (iTILs), and stromal tumor-infiltrating lymphocytes (sTILs). PD-1 was expressed in 13% of TCs, 85% of iTILs, and 94% of sTILs, while PD-L1 was observed in 46% of TCs, 96% of iTILs, and 100% of sTILs. PD-L2 was expressed in 79% of TCs and 100% of both iTILs and sTILs, with PD-L1/PD-L2 co-expression in 42% of TCs. Higher PD-1 IHC scores in TCs were associated with a less aggressive biological behavior; PD-L1 in iTILs was linked to skin ulceration, whereas PD-L2 in TCs was associated with its absence. Our findings highlight the relevance of the PD-1/PD-L1/PD-L2 immune checkpoint in rare FMC subtypes and support further investigation into checkpoint-blockade therapies. Full article

Gastrointestinal (GI) complications are common in diabetes, but the role of the local renin-angiotensin-aldosterone system (RAAS) in gut remodeling remains unclear. This study examined histomorphometric alterations, oxidative stress, and systemic and tissue-specific angiotensin converting enzyme (ACE) and ACE2 activity in streptozotocin (STZ)-induced diabetic rats. Adult male Wistar rats (n = 24) were assigned to control (CTRL), diabetic (STZ), and diabetic groups treated with losartan (STZ-LOS, 20 mg/kg/day) or finerenone (STZ-FIN, 10 mg/kg/day). After 14 days, gut samples were collected from the stomach, duodenum, jejunum, ileum, and colon for histology, glutathione measurements (GSH/GSSG), and ACE/ACE2 activity assessment. Diabetic rats exhibited increased GI wall thickness—particularly in the mucosal and muscular layers—elevated GSSG levels, and a reduced GSH/GSSG ratio. Losartan prevented these changes, whereas finerenone did not produce a significant effect. Circulating ACE and ACE2 levels were elevated, but the ACE2/ACE ratio remained unchanged. Locally, ACE activity increased across gut segments, whereas ACE2 remained stable, lowering the ACE2/ACE ratio, particularly in the duodenum and jejunum. The Z-FHL/h-HL ratio was above 1 across segments but decreased in these same regions (jejunum and duodenum). These findings highlight the protective role of losartan against diabetic GI remodeling via AT₁R blockade and suggest complex, segment-specific RAAS regulation in diabetic gut pathology. Full article

Background/Objectives: The homeless population (HP) is a heterogeneous group characterized by the absence of stable and conventional housing, often relying on public spaces and deteriorated environments for shelter and survival, either temporarily or permanently. This group is exposed to multiple health vulnerabilities, with substance use disorder (SUD) identified as a significant risk factor for suicidal behavior. The aim of this study was to conduct a scoping review of the relationship between PAS use and suicide among homeless individuals. Methods: A comprehensive literature search was performed using five databases: PubMed, Scopus, SciELO, LILACS, and Google Scholar. Studies were selected based on their relevance to the topic, and data were extracted regarding substance use, suicide-related outcomes, and associated sociodemographic and clinical factors. Results: The findings indicated a strong association between PAS use and increased suicidal ideation and behavior among homeless individuals, particularly among youth, men, and women. Opioids and alcohol were the most frequently reported substances in this context. Additional factors such as unemployment, exposure to violence, social inequalities, and mental health disorders further exacerbated the risk of suicide in this population Conclusions: The reviewed literature underscores the urgent need for integrated, context-sensitive interventions addressing both substance use and mental health among the homeless. Tailored public health strategies focused on prevention, harm reduction, and psychosocial support are essential to reducing suicide risk and promoting overall well-being in this highly vulnerable group. Full article

Diabetes is a metabolic disorder characterized by chronic hyperglycemia, affecting between 0.21% and 1.24% of cats. While gastrointestinal complications are well-documented in human diabetic patients—affecting up to 75%—similar data in cats remain scarce. This study explores gastrointestinal alterations in diabetic cats using ultrasound and histopathological evaluations, alongside assessing owners’ perceptions of digestive issues. A brief survey was conducted with the owners of diabetic cats to document diabetes symptoms and any gastrointestinal changes. Following the survey, each cat underwent abdominal US, focusing on the digestive tract including the stomach, duodenum, jejunum, ileum, and colon. Additionally, histopathological analysis was conducted on necropsied diabetic cats. Thirteen domestic spayed diabetic cats with no prior gastrointestinal disease were included, with 83% showing at least one gastrointestinal issue reported by owners. All cats exhibited increased gastric, duodenal, and jejunal wall thickness, while the ileum and colon showed normal thickness. Histopathological evaluation revealed increased thickness of the muscular layers, inflammatory infiltrate, and collagen deposits in the whole length of the gastrointestinal tract. These findings suggest that diabetic cats may experience gastrointestinal remodeling, a phenomenon that, while well recognized in human diabetes, has not been adequately studied in feline patients. Full article

Background/Objectives: Cannabidiol (CBD) has been reported for its antinociceptive, anti-inflammatory, and neuroprotective activities. However, several legal restrictions on its medicinal uses and even research have contributed to the development of synthetic analogues. Therefore, the aim of this study was the design and synthesis of a novel series of CBD-based structural analogues, and the in vivo evaluation of their potential antinociceptive activity. Methods: Using a two-step synthetic route, 26 new terpene-cinnamoyl acyl-hydrazone analogues were obtained and were submitted to in vivo screening in the classical formalin-induced paw edema and hot plate assays. Results: The compounds PQM-292, PQM-293, PQM-295, PQM-307, PQM-308, and PQM-309 exhibited the best results in the neurogenic phase (first phase) of the formalin-induced licking response, showing comparable results to morphine. Notably, in the inflammatory phase (second phase), compound PQM-292 exhibited the best anti-inflammatory activity. Interestingly, in the hot plate model, six other compounds (PQM-274, PQM-291, PQM-294, PQM-304, PQM-305, and PQM-378) showed the best antinociceptive activity in comparison to morphine, especially PQM-274, which exhibited an antinociceptive effect almost equivalent to the reference drug. Interestingly, these findings suggested that these bioactive compounds, despite their structural similarity, act through different mechanisms, which were investigated by molecular docking with CB1, CB2, and TRPV1 receptors. In silico results indicated that the most active compounds should act through different mechanisms, probably involving interactions with TRPA1. Conclusions: Therefore, due to the promising antinociceptive activity observed for these highlighted compounds, particularly for PQM-292 and PQM-274, without apparent toxicity and psychoactive effects, and the possible involvement of diverse mechanisms of action, these compounds could be considered as promising starting points to the development of new drug candidate prototypes of clinical interest. Full article

Enterococcus faecalis and Enterococcus faecium are frequently associated with persistent endodontic infections due to their ability to form biofilms and resist conventional treatments. The aim of this study was to evaluate the antibacterial and antibiofilm effects of Lavandula dentata L. essential oil at 100% against the standard and clinical strains of Enterococcus spp. The minimum bactericidal concentration (MBC) of L. dentata essential oil for each bacterial strain was determined. The antibiofilm effect was evaluated by an MTT assay. Data were statistically analyzed by the ANOVA and Tukey test, with a significance level of 5%. The MBC value was 32% (292.8 mg/mL) against all the tested strains. L. dentata significantly reduced E. faecalis and E. faecium biofilms at 16–64% (146.4–585.6 mg/mL) concentrations, with effects comparable to 2% chlorhexidine (CHX) (p ≥ 0.05). Biofilm reduction was strain-dependent at 30 min but showed broader efficacy after 24 h, particularly against E. faecium clinical strains (p ≤ 0.001). L. dentata demonstrated effective antimicrobial activity against planktonic and biofilm forms of E. faecalis and E. faecium as it reduced biofilm formation at a concentration of 16% and 64% (146.4 and 585.6 mg/mL), with results comparable to 2% CHX after 30 min and 24 h. L. dentata EO may serve as a potential alternative or adjunctive antimicrobial agent in endodontic treatment. However, the study’s limitations included the in vitro design and lack of cytotoxicity assessment. Full article

Hemerocallis citrina is an herbaceous perennial plant used in Asian cuisine and Traditional Chinese Medicine. Here, we tested the therapeutic potential of extracts (HCE30%, HCE50%, and HCN) in vivo, using models of two human genetic neurodegenerative diseases—Machado–Joseph Disease/Spinocerebellar Ataxia type 3 (MJD/SCA3) and Frontotemporal Dementia with Parkinsonism associated to chromosome 17 (FTDP-17). Chronic treatment with HCE30% extract ameliorated the motor deficits typically observed in these models. Interestingly, we found that the effect on the motor phenotype of the MJD/SCA3 model was dependent on serotonergic signaling and on the action of the HLH-30/TFEB transcription factor, known to regulate the cellular response to amino acid starvation, the autophagy and mitophagy pathways, lysosome localization and biogenesis, exocytosis, and mitochondrial biogenesis. Altogether, our findings reinforce the idea that phytochemicals act through the modulation of serotonergic neurotransmission and introduce a novel layer to the HLH-30/TFEB regulatory network. Thus, it also strengthens the use of these pathways as therapeutic targets for protein-related neurodegenerative disorders and confirms the utility of medicinal plants as a source of innovation in the quest for new therapeutic agents. Full article

Silicon has emerged as a beneficial element in mitigating water deficit in various crops, although the underlying mechanisms still require further investigation. This study evaluated the foliar content of nutrients (N, P, K, and Ca) and proline, antioxidant activity, growth, water use efficiency, and yield of cowpea cultivars subjected to two irrigation depths (50% and 100% of crop evapotranspiration) and a foliar application of silicon (orthosilicic acid). A field experiment was conducted in a split-plot scheme using the randomized block design with four replications in a semi-arid region of northeastern Brazil. Silicon supplementation increased the foliar contents of N, P, and Ca; stimulated proline synthesis; and enhanced the activity of the SOD, CAT, and APX enzymes. These changes promoted growth, improved water use efficiency, and increased crop yield. The results indicate that foliar silicon application mitigates the effects of water deficit in cowpea plants while enhancing crop performance under full irrigation (100% of crop evapotranspiration), leading to higher yields even under favorable water conditions. Full article

Coronavirus disease 2019 (COVID-19) still causes death in elderly and immunocompromised individuals, for whom the sustainability of the vaccine response may be limited. Antiviral treatments, such as remdesivir or molnupiravir, have demonstrated limited clinical efficacy. Nirmatrelvir, an acute respiratory syndrome coronavirus 2 (SARS-CoV-2) major protease inhibitor, is clinically effective but has been associated with viral rebound and antiviral resistance. It is thus necessary to study novel and repurposed antivirals for the treatment of COVID-19. We previously demonstrated that daclatasvir (DCV), an inhibitor of the hepatitis C virus (HCV) NS5A protein, impairs SARS-CoV-2 replication by targeting viral RNA polymerase and exonuclease, but the doses of DCV used to inhibit the new coronavirus are greater than the standard human plasma exposure for hepatitis C. Because any potential use of DCV against SARS-CoV-2 would be shorter than that reported here and short-term toxicological studies on DCV show that higher doses are tolerable, we searched for doses of DCV that could protect transgenic mice expressing the human ACE2 receptor (K18-hACE-2) from lethal challenge with SARS-CoV-2. We found that a dose of 60 mg/kg/day provides this protection by reducing virus replication and virus-induced lung insult. This dose is tolerable in different animal models. Taken together, our data provide preclinical evidence that can support phase I clinical trials to confirm the safety, tolerability, and pharmacokinetics of new doses of daclatasvir for a short duration in humans to further advance this compound’s utility against COVID-19. Full article

Necrosis is a common finding in human and animal neoplasms. The percentage of tumor necrosis is included in tumor grading schemes in veterinary oncology; however, evaluation methods are often overlooked. Different studies have assessed the prognostic value of tumor necrosis in feline mammary tumors with contradictory results, which could be related to methodologic variability. In this study, a comprehensive evaluation of tumor necrosis in feline mammary tumors (FMTs) was conducted, by applying a semi-quantitative and a quantitative methodology for assessing necrosis. The interobserver agreement, the relationship with clinicopathological characteristics and the prognostic value of necrosis were analyzed in 154 FMT cases. Although subjectivity in the assessment of necrosis existed, an almost perfect agreement (weighted quadratic k = 0.851) between two observers was obtained. Furthermore, there was a significant positive correlation between the semi-quantitative and quantitative methods. Necrosis was more common and more extensive in malignant tumors than in their benign counterparts. Despite the non-significant results in the survival analysis, extensive necrosis was significantly associated with aggressive clinicopathological features, such as higher histological grade, high mitotic count and lymphovascular invasion. Our results support the potential relevance of necrosis in FMT. Full article

Gastrointestinal complications of diabetes are often overlooked, despite affecting up to 75% of patients. This study innovatively explores local glutathione levels and morphometric changes in the gut of Goto–Kakizaki (GK) rats, a type 2 diabetes animal model. Segments of the intestine, cecum, and colon were collected for histopathological analysis and glutathione quantification. A significant increase in the total thickness of the intestinal wall of GK rats was observed, particularly in the duodenum (1089.02 ± 39.19 vs. 864.19 ± 37.17 µm), ileum (726.29 ± 24.75 vs. 498.76 ± 16.86 µm), cecum (642.24 ± 34.15 vs. 500.97 ± 28.81 µm), and distal colon (1211.81 ± 51.32 vs. 831.71 ± 53.2 µm). Additionally, diabetic rats exhibited thickening of the muscular layers in all segments, except for the duodenum, which was also the only portion where the number of smooth muscle cells did not decrease. Moreover, myenteric neuronal density was lower in GK rats, suggesting neurological loss. Total glutathione levels were lower in all intestinal segments of diabetic rats (except duodenum), and the reduced/oxidized glutathione ratio (GSH/GSSG) was significantly decreased in GK rats, indicating increased oxidative stress. These findings strongly indicate that GK rats undergo significant intestinal remodeling, notable shifts in neuronal populations, and heightened oxidative stress—factors that likely contribute to the functional gastrointestinal alterations seen in diabetic patients. Full article

Obesity causes insulin resistance (IR) through systemic low-grade inflammation and can lead to type 2 diabetes mellitus (T2DM). However, the mechanisms that cause IR and T2DM in non-obese individuals are unclear. The Goto-Kakizaki (GK) rat develops IR spontaneously and is a model of non-obese T2DM. These rats exhibit hyperglycemia beginning at weaning and exhibit lower body mass than control Wistar rats. Herein, we tested the hypothesis that macrophages of GK rats are permanently in a pro-inflammatory state, which may be associated with a systemic inflammation condition that mimics the pathogenesis of obesity-induced T2DM. Using eighteen-week-old GK and control Wistar rats, we investigated the proportions of M1 (pro-inflammatory) and M2 (anti-inflammatory) macrophages isolated from the peritoneal cavity. Additionally, the production of inflammatory cytokines and reactive oxygen species (ROS) in cultured macrophages under basal and stimulated conditions was assessed. It was found that phorbol myristate acetate (PMA) stimulation increased GK rat macrophage ROS production 90-fold compared to basal levels. This response was also three times more pronounced than in control cells (36-fold). The production of pro-inflammatory cytokines, such as tumor necrosis factor-alpha (TNF-α), tended to be upregulated in cultured macrophages from GK rats under basal conditions. Macrophages from GK rats produced 1.6 times more granulocyte-macrophage colony-stimulating factor (GM-CSF), 1.5 times more monocyte chemoattractant protein-1 (MCP-1) and 3.3 times more TNF-α than control cells when stimulated with lipopolysaccharide (LPS) (p = 0.0033; p = 0.049; p = 0.002, respectively). Moreover, compared to control cells, GK rats had 60% more M1 (p = 0.0008) and 23% less M2 (p = 0.038) macrophages. This study is the first to report macrophage inflammatory reprogramming towards a pro-inflammatory state in GK rats. Full article

The increasing frequency and duration of marine heatwaves (MHWs) due to climate change pose severe threats to aquaculture, causing drastic physiological and growth impairments in farmed fish, undermining their resilience against additional environmental pressures. To ensure sustainable production that meets the global seafood demand and animal welfare standards, cost-effective and eco-friendly strategies are urgently needed. This study explored the efficacy of the red macroalga Asparagopsis taxiformis on juvenile white seabream Diplodus sargus reared under optimal conditions and upon exposure to a MHW. Fish were fed with four experimental diets (0%, 1.5%, 3% or 6% of dried powdered A. taxiformis) for a prophylactic period of 30 days (T30) and subsequently exposed to a Mediterranean category II MHW for 15 days (T53). Biometric data and samples were collected at T30, T53 and T61 (8 days post-MHW recovery), to assess performance indicators, biomarker responses and histopathological alterations. Results showed that A. taxiformis supplementation improved catalase and glutathione S-transferase activities and reduced lipid peroxidation promoted by the MHW, particularly in fish biofortified with 1.5% inclusion level. No histopathological alterations were observed after 30 days. Additionally, fish biofortified with 1.5% A. taxiformis exhibited increased citrate synthase activity and fish supplemented with 1.5% and 3% showed improved digestive enzyme activities (e.g., pepsin and trypsin activities). Overall, the present findings pointed to 1.5% inclusion as the optimal dosage for aquafeeds biofortification with A. taxiformis, and confirmed that this seaweed species is a promising cost-effective ingredient with functional properties and great potential for usage in a climate-smart context. Full article

Candida albicans is one of the agents of invasive candidiasis, a life-threatening disease strongly associated with hospitalization, particularly among patients in intensive care units with central venous catheters. This study aimed to evaluate the synergistic activity of the antifungal peptide ToAP2 combined with fluconazole against C. albicans biofilms grown on various materials. We tested combinations of different concentrations of the peptide ToAP2 with fluconazole on C. albicans biofilms. These biofilms were generated on 96-well plates, intravenous catheters, and infusion tubes in RPMI medium at two maturation stages. Scanning electron microscopy and atomic force microscopy were employed to assess the biofilm structure. We also evaluated the expression of genes previously proven to be involved in C. albicans biofilm formation in planktonic and biofilm cells after treatment with the peptide ToAP2 using qPCR. ToAP2 demonstrated a synergistic effect with fluconazole at concentrations up to 25 µM during both the early and mature stages of biofilm formation in 96-well plates and on medical devices. Combinations of 50, 25, and 12.5 µM of ToAP2 with 52 µM of fluconazole significantly reduced the biofilm viability compared to individual treatments and untreated controls. These results were supported by substantial structural changes in the biofilms observed through both scanning and atomic force microscopy. The gene expression analysis of C. albicans cells treated with 25 µM of ToAP2 revealed a decrease in the expression of genes associated with membrane synthesis, along with an increase in the expression of genes involved in efflux pumps, adhesins, and filamentation. Our results highlight the efficacy of the combined ToAP2 and fluconazole treatment against C. albicans biofilms. This combination not only shows therapeutic potential but also suggests its utility in developing preventive biofilm tools for intravenous catheters. Full article