Toxicity Assessment of New Ag-ZnO/AgO Nanocomposites: An In Vitro and In Vivo Approach.

Zinc oxide nanoparticles (ZnO NPs) are metal oxide nanomaterials, which are important for several applications: antibacterial, anthelmintic, antiprotozoal and antitumoral, among others. These applications are mainly related to the ability to spontaneously produce and induce the production of reactive oxygen species that are important components for the destruction of pathogens and tumor cells. While trying to potentiate ZnO NPs, studies have associated these NPs with silver oxide (AgO) or silver (Ag) NPs. It has already been reported that this combination (Ag-ZnO/AgO NPs) is able to enhance the microbicidal potential. Although possessing much potential for several purposes, it is important to evaluate whether this association also poses the risk of toxicity to cells and experimental models. Therefore, this work aimed to evaluate the toxicity of various Ag-ZnO/AgO NP nanocomposites, in vitro and in vivo. Accordingly, ZnO nanocrystals and nanocomposites with various concentrations of AgO (ZnO:5Ag, ZnO:9Ag or ZnO:11Ag) were used in different cytotoxicity models: Galleria mellonella (G. mellonella), cell lines (VERO and RAW 264.7) and C57BL/6 mice. In the G. mellonella model, four concentrations were used in a single dose, with subsequent evaluation of mortality. In the case of cells, serial concentrations starting at 125 µg/mL were used, with subsequent cytotoxicity assessment. Based on the safe doses obtained in G. mellonella and cell models, the best doses were used in mice, with subsequent evaluations of weight, biochemistry as also renal and liver histopathology. It was observed that the toxicity, although low, of the nanocomposites was dependent upon the concentration of AgO used in association with ZnO NPs, both in vitro and in vivo.

Melatonin: A look at protozoal and helminths.

Melatonin is a pleiotropic neurohormone found in different animal, plant, and microorganism species. It is a product resulting from tryptophan metabolism in the pineal gland and is widely known for its ability to synchronize the circadian rhythm to antitumor functions in different types of cancers. The molecular mechanisms responsible for its immunomodulatory, antioxidant and cytoprotective effects involve binding to high-affinity G protein-coupled receptors and interactions with intracellular targets that modulate signal transduction pathways. In vitro and in vivo studies have reported the therapeutic potential of melatonin in different infectious and parasitic diseases. In this review, the protective and pathophysiological roles of melatonin in fighting protozoan and helminth infections and the possible mechanisms involved against these stressors will be discussed.

Effects of coenzyme Q10 and N-acetylcysteine on experimental poisoning by paracetamol in Wistar rats.

Paracetamol (PAR) is a drug widely used in human and veterinary medicine as an analgesic and antipyretic, often involved in cases of intoxication. The most common clinical signs result from damage to red blood cells and hepatocytes, and this intoxication is considered a model for the induction of acute liver failure. In the present study, the hepatoprotective effects of coenzyme Q10 (CoQ10) and N-acetylcysteine (NAC) against experimental paracetamol (PAR) poisoning were analysed. Thirty-five adult Wistar rats (Rattus novergicus albinus) were randomly assigned to five groups, and thirty-one of these survived the treatments. Negative control group (CON-) received 1mL of 0.9% NaCl orally (PO). Other groups received 1.2g/kg of PAR (PO). Positive control group (CON+) received only PAR. NAC group received 800 mg/kg intraperitoneally (IP) of NAC 1h after the administration of PAR and at 12 h received 1mL of 0.9% NaCl, IP. The fourth group (CoQ10) received 1h and 12 h after intoxication, CoQ10 (10mg/kg IP). And the fifth group (NAC+CoQ10) received NAC (800mg/kg, IP) and CoQ10 (10mg/kg, IP). After 12 hours, the rats were euthanized and necropsied to collect liver and kidney tissues for histopathological evaluation and electronic microscopy. A single dose of PAR caused severe acute hepatitis. NAC couldn't reverse the liver and kidney damages. The group that received CoQ10 and NAC had moderate liver damage, while the group that received only CoQ10 had lower values of liver enzymes and mild liver and kidney damage. Animals that received treatment with CoQ10 or NAC+CoQ10 presented normal hepatocyte mitochondria and nuclei. Although CoQ10 couldn't reverse PAR organ damage, results indicate promising hepatoprotection in Wistar rats.

Revisiting the hallmarks of cancer: A new look at long noncoding RNAs in breast cancer.

Breast cancer is one of the leading causes of death in women worldwide. The increasing understanding of the molecular mechanisms underlying its heterogeneity favors a better understanding of tumor biology and consequently the development of better diagnostic and treatment techniques. The advent of tumor genome sequencing techniques has highlighted more participants in the process, in addition to protein-coding genes. Thus, it is now known that long noncoding RNAs, previously described as transcriptional noise with no biological function, are intimately associated with tumor development. In breast cancer, they are abnormally expressed and closely associated with tumor progression, which makes them attractive diagnostic biomarkers and prognostic and specific therapeutic targets. Therefore, a thorough understanding of the regulatory mechanisms of long noncoding RNAs in breast cancer is essential for the search for new treatment strategies. In this review, we summarize the major long noncoding RNAs and their association with the cancer characteristics of the ability to sustain proliferative signaling, evasion of growth suppressors, replicative immortality, activation of invasion and metastasis, induction of angiogenesis, resistance to cell death, reprogramming of energy metabolism, genomic instability and sustained mutations, promotion of tumor inflammation, and evasion of the immune system. In addition, we report and suggest how they can be used as prognostic biomarkers and possible therapeutic targets.

Low-power laser in increasing doses improve wound healing process in rats.

Low-power laser has been studied and applied as an auxiliary tool in wound healing. However, as it is a therapy with several variables to be controlled, there is great difficulty in establishing protocols and comparing its efficacy. Therefore, the objective of this study was to evaluate the effects of the use of low-power laser in fixed and crescent doses in the healing of skin wounds in rats. Seventy-five male Wistar rats were divided into three groups: G1 with animals that did not receive laser radiation; G2 with animals treated with fixed dose of 3 J/cm2 laser; G3 with animals treated with laser in increasing doses of 1 J/cm2, 3 J/cm2, 5 J/cm2. Macroscopic and histological analysis were performed. The lowest intensity of PMN was observed in the irradiated groups and G3 had lower intensity of this infiltrate compared to G1 and G2 (p <0.05). On the seventh day of injury, PMN infiltrate decreased in all groups, especially in G3 (p<0.05). It was observed that G2 had more blood vessels than G1 and G3 after 7 days of wound creation (p ˂ 0.05). Collagen quantification showed that laser-treated groups have increased collagen deposition. Different responses in the wound healing process were observed comparing G2 and G3 groups. The fluence of 1J/cm2 presented better results in the anti-inflammatory action than 3 J/cm2, although G3 presented the greatest amount of total collagen after ten days of treatment.

Caryocar brasiliense peel ethanolic extract has neuroprotective potential and reduces the activation of ERK1/2 in the ischemia and reperfusion brain acute phase in the rat.

Oxidative stress induced by ischemia and reperfusion (I/R) injury results in cell death by necrosis or apoptosis and triggers the activation of different intracellular pathways, such as mitogen-activated protein activated kinases. Pequi (Caryocar brasiliense) peel, residue of a fruit from Brazilian savannah-like vegetation, has phenolic compounds that have been demonstrated to have antioxidant effects in vitro. The present study aimed to evaluate the neuroprotective effects of C. brasiliense peel ethanolic extract (CBPE) against transient global I/R injury in the rat brain. Global ischemia for 5, 20, and 45 min followed by 2 h of reperfusion caused a significant time-dependent increase in the number of ischemic neurons (p ≤ 0.05); increased immunoreactivity of cleaved caspase-3 (CASP3); and activated extracellular signal-regulated kinase (ERK) 1/2. Pretreatment with CBPE (600 mg/kg, oral) or vitamin E (0.6 mg, oral) for 30 days showed significant protection against acute brain injury induced by 20 and 45 min or 5 min of ischemia, respectively, by reducing the cortical ischemic neuron count (p ≤ 0.05) and p-ERK1/2 immunoreactivity. In addition, active c-Jun N-terminal kinase (JNK) immunoreactivity was reduced in animals not subjected to ischemia. Therefore, we suggest an association between vitamin E and CBPE, which may generate a better neuroprotective response. Interestingly, mainly in the hippocampus and oligodendrocytes, high dose CBPE increase the number of isquemic neurons and of CASP3 immunoreactive cells in animals subjected or not to ischemia, which was not verified in the vitamin E group. Therefore, additional studies are recommended to verify the safety of the continuous use of CBPE.

Cancer and Trypanosoma cruzi: Tumor induction or protection?

Trypanosoma cruzi causes Chagas disease, a neglected disease that can be divided, overall, into acute and chronic phases. Understanding the mechanisms underlying its progression is based on the parasite-host interactions occurring during the infection. Although the pathophysiology of the main symptomatic forms of Chagas disease has been the subject of several studies, little is known about their relationship with the development of different types of cancer. Therefore, knowledge regarding the molecular aspects of infection in the host, as well as the influence of the immune response in the parasite and the host, can help to understand the association between Chagas disease and tumor development. This review aims to summarize the main molecular mechanisms related to T. cruzi-dependent carcinogenic development and the mechanisms associated with tumor protection mediated by different parasite components.

Antitumor effect of melatonin on breast cancer in experimental models: A systematic review.

Breast cancer is the most frequent malignant neoplasm in females. While conventional treatments such as chemotherapy and radiotherapy are available, they are highly invasive and toxic to oncological patients. Melatonin is a promising molecule for the treatment of breast cancer with antitumor effects on tumorigenesis and tumor progression. The aim of this systematic review was to synthesize knowledge about the antitumor effect of melatonin on breast cancer in experimental models and propose the main mechanisms of action already described in relation to the processes regulated by melatonin. PubMed, Web of Science, and Embase databases were used. The inclusion criteria were in vitro and in vivo experimental studies that used different formulations of melatonin as a treatment for breast cancer, without year or language restrictions. Risk of bias for studies was assessed using the Systematic Review Center for Laboratory Animal Experimentation (SYRCLE) tool. Data from selected articles were presented as narrative descriptions and tables. Seventy-five articles on different breast cancer cell lines and experimental models treated with melatonin alone, or in combination with other compounds were included. Melatonin showed antitumor effects on proliferative pathways related to the cell cycle and tumorigenesis, tumor death, angiogenesis, and tumor metastasis, as well as on oxidative stress and immune regulatory pathways. These effects were either dependent or independent of melatonin receptors. Herein, we clarify the antitumor action of melatonin on different tumorigenic processes in breast cancer in experimental models. Systematic review registration: PROSPERO database (CRD42022309822/https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42022309822).

A Revision of Polymeric Nanoparticles as a Strategy to Improve the Biological Activity of Melatonin.

Drug delivery systems based on nanotechnology exhibit a number of advantages over traditional pharmacological formulations. Polymeric nanoparticles are commonly used as delivery systems and consist of synthetic or natural polymers that protect drugs from degradation in physiological environments. In this context, indolamine melatonin has been associated with several biological functions, including antioxidant, antitumor, immunoregulatory, neuroprotective, and cardioprotective effects. However, its availability, half-life, and absorption depend upon the route of administration, and this can limit its therapeutic potential. An alternative is the use of polymeric nanoparticle formulations associated with melatonin to increase its bioavailability and therapeutic dose at sites of interest. Thus, the objective of this review is to provide a general and concise approach to the therapeutic association between melatonin and polymeric nanoparticles applied to different biological disorders and to also highlight its advantages and potential applications compared to those of the typical drug formulations that are available.

Topical application of melatonin accelerates the maturation of skin wounds and increases collagen deposition in a rat model of diabetes.

AIMS: This study aimed to evaluate the cicatricial potential of melatonin when applied to wounds of diabetic rats. MATHERIALS AND METHODS: The formulation containing melatonin was developed and applied topically to cutaneous wounds of diabetic rats. 48 Wistar rats were used, divided into two groups of 24 diabetic animals each: (i) control group (CG), the animals received topical application of the no-melatonin formulation; (ii) treatment group (TG), the animals received topical application of the melatonin-containing formulation. All animals in each group were treated at four time points: 3, 7, 14, and 21 days. Each subgroup consisted of six animals. RESULTS: The treatment with melatonin improved wound healing by promoting wound closure earlier than the control group evaluated. Also improved a better resolution of the inflammatory phase observed mainly at 7 days, higher tissue maturation and expressive collagen deposition. CONCLUSION: The observed data reveal that the use of melatonin topically could be a promising strategy for the healing of wounds in diabetes. The results of this study elucidate the effects of previously described pathways in which it is proposed that melatonin acts promoting wound healing in diabetes.

Local tumour nanoparticle thermal therapy: A promising immunomodulatory treatment for canine cancer.

Distinct thermal therapies have been used for cancer therapy. For hyperthermia (HT) treatment the tumour tissue is heated to temperatures between 39 and 45°C, while during ablation (AB) temperatures above 50°C are achieved. HT is commonly used in combination with different treatment modalities, such as radiotherapy and chemotherapy, for better clinical outcomes. In contrast, AB is usually used as a single modality for direct tumour cell killing. Both thermal therapies have been shown to result in cytotoxicity as well as immune response stimulation. Immunogenic responses encompass the innate and adaptive immune systems and involve the activation of macrophages, dendritic cells, natural killer cells and T cells. Several heat technologies are used, but great interest arises from nanotechnology-based thermal therapies. Spontaneous tumours in dogs can be a model for cancer immunotherapies with several advantages. In addition, veterinary oncology represents a growing market with an important demand for new therapies. In this review, we will focus on nanoparticle-mediated thermal-induced immunogenic effects, the beneficial potential of integrating thermal nanomedicine with immunotherapies and the results of published works with thermotherapies for cancer using dogs with spontaneous tumours, highlighting the works that evaluated the effect on the immune system in order to show dogs with spontaneous cancer as a good model for evaluated the immunomodulatory effect of nanoparticle-mediated thermal therapies.

Polysaccharide-Based Membrane Biocompatibility Study of Anacardium occidentale L. and Polyvinyl Alcohol after Subcutaneous Implant in Rats.

Polymeric membranes are a viable and sustainable option for the biotechnology industry from an economic and environmental point of view. In this study, we evaluated tissue response and tolerance to the implantation of a polymeric membrane prepared with cashew gum polysaccharide (CGP) associated with polyvinyl alcohol (PVA). The objective was to characterize the biocompatibility of the CGP/PVA membrane in vivo. Following the evaluation criteria of the ISO 10993-6 standard, we demonstrated that the CGP/PVA membrane showed moderate tissue reaction, with a non-irritating ISO pattern, a thinner fibrous capsule, and a smaller amount of collagen compared to the positive control group. At 30 and 60 days, the membrane presented a similar amount of mast cells to that observed in the negative control group. The data demonstrate that the CGP/PVA membrane presents biocompatibility in accordance with the ISO 10993-6 standard.

HELICOBACTER PYLORI cagA VIRULENCE GENE AND SEVERE ESOGASTRODUODENAL DISEASES: IS THERE AN ASSOCIATION?

BACKGROUND: Helicobacter pylori colonizes approximately half of the world's human population. Its presence in the gastric mucosa is associated with an increased risk of gastric adenocarcinoma, gastric lymphoma, and peptic ulcer disease. In Brazil, the high prevalence of H. pylori infection is a serious health problem. H. pylori virulence factors are associated with an increased risk of serious gastrointestinal disorders. The cagA gene encodes a cytotoxin-A-associated antigen (CagA) that is involved in bacterial pathogenicity. H. pylori strains carrying the cag pathogenicity island (cag-PAI) are significantly associated with severe clinical outcomes and histopathological changes. OBJECTIVE: The present study aims to investigate the prevalence of the cagA gene among H. pylori isolates from patients with different gastric pathologies. Further, the study hopes to verify its association with clinical outcomes. In addition, phylogenetic analysis was performed on cagA-positive H. pylori strains from patients with severe and non-severe diseases. METHODS: Gastric specimens were collected through a biopsy from 117 patients with different esogastroduodenal diseases. DNA was extracted from these gastric specimens and the polymerase chain reaction was performed to amplify the gene fragments corresponding to the 16S ribosomal RNA and cagA genes using specific primers. The polymerase chain reaction products of selected samples positive for cagA were sequenced. The sequences were aligned with reference sequences from the National Center for Biotechnology Information (NCBI) (Bethesda/USA), and a phylogenetic tree was constructed. RESULTS: H. pylori was detected in 65.9% (77/117) of Brazilian patients with different gastroduodenal disorders. Overall, 80.5% (62/77) of the strains were cagA-positive. The ages of patients with cagA-positive strains (15 males and 47 females) ranged from 18 to 74 years. The lesions were categorized as non-severe and severe according to the endoscopic and histopathological reports the most prevalent non-severe esogastroduodenal lesion was gastritis 54/77 (70.12%), followed by esophagitis 12/77 (15.58%) and duodenitis 12/77 (15.58%). In contrast, the most prevalent severe lesions were atrophy 7/77 (9.09%), followed by metaplasia 3/77 (3.86%) and gastric adenocarcinoma 2/77 (2.59%). Phylogenetic analyses performed with the partial sequences of the cagA gene obtained from local strains were grouped in the same clade. No differences in phylogenetic distribution was detected between severe and non-severe diseases. CONCLUSION: The cagA gene is highly prevalent among H. pylori isolates from gastric lesions in Brazilian patients. The presence of the cagA gene was not considered a marker of the severity of esogastroduodenal lesions in the present study. This is the first study to investigate the phylogenetic population structure of H. pylori strains in a Brazilian capital, which may improve our understanding of the clinical outcome of H. pylori infection.

HELICOBACTER PYLORI cagA VIRULENCE GENE AND SEVERE ESOGASTRODUODENAL DISEASES: IS THERE AN ASSOCIATION? / Gene de virulência cagA de Helicobacter pylori e doenças esogastroduodenais severas: existe uma associação?

ABSTRACT BACKGROUND: Helicobacter pylori colonizes approximately half of the world's human population. Its presence in the gastric mucosa is associated with an increased risk of gastric adenocarcinoma, gastric lymphoma, and peptic ulcer disease. In Brazil, the high prevalence of H. pylori infection is a serious health problem. H. pylori virulence factors are associated with an increased risk of serious gastrointestinal disorders. The cagA gene encodes a cytotoxin-A-associated antigen (CagA) that is involved in bacterial pathogenicity. H. pylori strains carrying the cag pathogenicity island (cag-PAI) are significantly associated with severe clinical outcomes and histopathological changes. OBJECTIVE: The present study aims to investigate the prevalence of the cagA gene among H. pylori isolates from patients with different gastric pathologies. Further, the study hopes to verify its association with clinical outcomes. In addition, phylogenetic analysis was performed on cagA-positive H. pylori strains from patients with severe and non-severe diseases. METHODS: Gastric specimens were collected through a biopsy from 117 patients with different esogastroduodenal diseases. DNA was extracted from these gastric specimens and the polymerase chain reaction was performed to amplify the gene fragments corresponding to the 16S ribosomal RNA and cagA genes using specific primers. The polymerase chain reaction products of selected samples positive for cagA were sequenced. The sequences were aligned with reference sequences from the National Center for Biotechnology Information (NCBI) (Bethesda/USA), and a phylogenetic tree was constructed. RESULTS: H. pylori was detected in 65.9% (77/117) of Brazilian patients with different gastroduodenal disorders. Overall, 80.5% (62/77) of the strains were cagA-positive. The ages of patients with cagA-positive strains (15 males and 47 females) ranged from 18 to 74 years. The lesions were categorized as non-severe and severe according to the endoscopic and histopathological reports the most prevalent non-severe esogastroduodenal lesion was gastritis 54/77 (70.12%), followed by esophagitis 12/77 (15.58%) and duodenitis 12/77 (15.58%). In contrast, the most prevalent severe lesions were atrophy 7/77 (9.09%), followed by metaplasia 3/77 (3.86%) and gastric adenocarcinoma 2/77 (2.59%). Phylogenetic analyses performed with the partial sequences of the cagA gene obtained from local strains were grouped in the same clade. No differences in phylogenetic distribution was detected between severe and non-severe diseases. CONCLUSION: The cagA gene is highly prevalent among H. pylori isolates from gastric lesions in Brazilian patients. The presence of the cagA gene was not considered a marker of the severity of esogastroduodenal lesions in the present study. This is the first study to investigate the phylogenetic population structure of H. pylori strains in a Brazilian capital, which may improve our understanding of the clinical outcome of H. pylori infection.

RESUMO CONTEXTO: Helicobacter pylori coloniza aproximadamente metade da população humana mundial. A presença do microrganismo na mucosa gástrica está associada a um risco aumentado de adenocarcinoma gástrico, linfoma gástrico e úlcera péptica. No Brasil, a alta prevalência de infecção por H. pylori é um grave problema de saúde. Os fatores de virulência de H. pylori estão associados a risco aumentado de distúrbios gastrointestinais severos. O gene cagA codifica um antígeno associado à citotoxina A (CagA) que está envolvido na patogenicidade bacteriana. As cepas de H. pylori portadoras da ilha de patogenicidade cag (cag-PAI) estão significativamente associadas a desfechos clínicos severos e alterações histopatológicas. OBJETIVO: O presente estudo tem como objetivo investigar a prevalência do gene cagA entre isolados de H. pylori de pacientes com diferentes desordens gástricas, bem como verificar sua associação com desfechos clínicos. Além disso, a análise filogenética foi realizada em cepas de H. pylori cagA-positivas de pacientes com doenças severas e não severas. MÉTODOS: Amostras gástricas foram coletadas por meio de biópsia gástrica de 117 pacientes com diferentes doenças esogastroduodenais. O DNA foi extraído das amostras e utilizado para amplificar os fragmentos gênicos correspondentes aos genes RNA ribossomal 16S e cagA, através da reação em cadeia da polimerase. Os produtos da reação em cadeia da polimerase de amostras selecionadas positivas para cagA foram sequenciados e as sequências foram alinhadas com sequências de referência do National Center for Biotechnology Information (NCBI) (Bethesda/EUA). As análises filogenéticas foram realizadas a partir do sequenciamento e construção da árvore filogenética. RESULTADOS: H. pylori foi detectado em 65,9% (77/117) dos pacientes brasileiros com diferentes distúrbios gastroduodenais. No total, 80,5% (62/77) das cepas foram cagA-positivas. As idades dos pacientes com cepas cagA-positivas (15 homens e 47 mulheres) variaram de 18 a 74 anos. As lesões foram categorizadas como não severas e severas de acordo com o laudo endoscópico e histopatológico. A lesão esogastroduodenal não severa mais prevalente foi gastrite 54/77 (70,12%), seguida de esofagite 12/77 (15,58%) e duodenite 12/77 (15,58%). Em contraste, as lesões severas mais prevalentes foram atrofia 7/77 (9,09%), seguida de metaplasia 3/77 (3,86%) e adenocarcinoma gástrico 2/77 (2,59%). As análises filogenéticas realizadas com as sequências parciais do gene cagA obtidas de cepas locais foram agrupadas no mesmo clado. Nenhuma diferença na distribuição filogenética foi detectada entre doenças severas e não severas. CONCLUSÃO: O gene cagA é altamente prevalente entre isolados de H. pylori de lesões gástricas em pacientes brasileiros. A presença do gene cagA não foi considerada um marcador de severidade das lesões esogastroduodenais no presente estudo. Este é o primeiro estudo a investigar a estrutura filogenética da população de cepas de H. pylori em uma capital brasileira. Esses resultados irão contribuir para o entendimento sobre o desfecho clínico da infecção por H. pylori.

Autologous platelet-rich plasma action on skin autografts in horses / Ação do plasma rico em plaquetas autólogo em autoenxertos de pele em equinos

ABSTRACT: This study evaluated the action of autologous platelet-rich plasma (PRP) on cutaneous wounds, containing skin autografts, in the gluteal region of horses. Seven healthy horses were used. Two 6 x 6cm cutaneous wounds were produced on each side of the gluteal region. Eight days after wound induction, grafts were performed with skin fragments harvested from the neck, as well as the application of PRP, prepared by double-centrifugation protocol. Wounds with autografts on the left side received PRP (group T), and those with autografts on the right side did not receive treatment (group C). Macroscopic and microscopic evaluations were performed, considering the integration of autografts and retraction of wound edges, as well as neovascularization, inflammatory infiltrate, young fibroblasts, collagenization, reepithelization and autografts integration. There was no difference between the groups (P > 0.05) in relation to most macroscopic and microscopic variables. However, neovascularization was significantly greater (p = 0.0191) in group T, on the 14th day after grafting. It is concluded that PRP favors the process of skin repair with autografts in horses, since it increases the neovascularization in the initial phase of wound healing. Furthermore, the PRP seems to positively influence the integration of the skin autografts and the retraction of the wound edges.

RESUMO: Este estudo avaliou a ação do plasma rico em plaquetas (PRP) autólogo em feridas cutâneas, contendo autoenxertos de pele em equinos. Foram utilizados sete equinos hígidos, nos quais foram produzidas duas feridas cutâneas de 6 x 6cm, em cada um dos lados da região glútea. Oito dias após a indução das feridas, foram realizados enxertos com fragmentos de pele colhidos do pescoço, assim como a aplicação do PRP, preparado através de protocolo de dupla centrifugação. As feridas com autoenxertos do lado esquerdo receberam PRP (grupo T), e as com autoenxertos do lado direito não receberam tratamento (grupo C). Foram realizadas avaliações macroscópica e microscópica, considerando as variáveis integração dos autoenxertos e retração das bordas da ferida, além de neovascularização, infiltrado inflamatório, fibroblastos jovens, colagenização, reepitelização e integração dos autoenxertos. Não houve diferença entre os grupos (p > 0,05) em relação à maioria das variáveis macroscópicas e microscópicas. Contudo, a neovascularização foi significativamente maior (P = 0,0191) no grupo T, no 14º dia após a realização da enxertia. Conclui-se que o PRP favorece o processo de reparo da pele com autoenxertos em equinos, já que aumenta a neovascularização na fase inicial da cicatrização da ferida. Ainda, o PRP parece influenciar positivamente a integração dos autoenxertos de pele e a retração das bordas da ferida.

B-Mode and Doppler Ultrasonography in a Murine Model of Ehrlich Solid Carcinoma With Different Growth Patterns.

Ehrlich solid carcinoma (ESC) is one of the tumor models used in cancer research. Although it is widely used, it has no ultrasonographic descriptions. In this study, serial B-mode and Doppler ultrasonographic examinations were performed for 23 days for ESCs inoculated into 18 Swiss albino mice. The growth patterns were analyzed, and on the basis of their growth curve, the tumors were classified into two groups: fast growth (FG) and slow growth (SG). Ultrasonographic characteristics of the tumor's capsule, margins, echogenicity, echotexture, vascular index (VI), distribution of vascular flow, and Doppler indices such as the resistive index, pulsatility index, and peak systolic velocity (SV) were analyzed and compared between the two groups. A high VI and earlier blood flow were noted in the FG group (p<0.05). Additionally, SV was higher in the FG group than in the SG group (13.28 ± 0.38 cm/s vs. 8.43 ± 0.26 cm/s). In contrast, a change in echogenicity and flow distribution patterns were observed, especially in FG tumors. Therefore, ESC presented with few ultrasonographic differences between FG and SG tumors, especially vascularization during the initial stages of tumor growth.

Fatal metaldehyde poisoning in a dog confirmed by gas chromatography.

BACKGROUND: Metaldehyde is a toxic pesticide used mainly as a molluscicide, responsible for intoxication and deaths in both humans and animals. Accidental exposure to metaldehyde in dogs is considered rare, but severe. Data concerning clinical and veterinary forensic toxicology are largely incomplete, especially regarding case reports in dogs. The present work reports a complete and detailed description of a case from the history, clinical evolution, pathological exams and toxicological diagnosis in an accidental case of metaldehyde poisoning in dog. CASE PRESENTATION: An eleven-month-old, 3.0 kg, male German Spitz was presented for emergency care with acute vomiting and seizures 3 hours after suspected accidental ingestion of commercial molluscicide containing 3% metaldehyde (Lesmax®). The animal was in lateral recumbency and showed stuporous mentation, salivation, tonic-clonic status epilepticus, systemic tremors, bilateral miosis, absent palpebral, corneal, oculovestibular and gag reflexes, severely depressed spinal reflexes, dyspnea and tachycardia. Despite treatment, the patient progressed to comatose mentation and died. Necropsy examination revealed discrete lesions in the liver and central nervous system, while stomach examination revealed content of feed, activated charcoal and blue-green granules, compatible to the commercial formula of metaldehyde. Histology examination revealed extensive hemorrhage and severe centrolobular necrosis of the liver and tumefaction of Kupfer cells. Brain samples showed discrete hemorrhage and hyperemia. In order to confirm the diagnosis, samples from feces, stomach content, spleen, liver, heart, kidneys and brain were submitted gas chromatography analysis. Results confirmed the presence of metaldehyde in all samples. We describe clinicopathological abnormalities of a fatal case of metaldehyde poisoning in a dog, as well as postmortem diagnosis using gas chromatography. CONCLUSION: Metaldehyde poisoning is rarely reported, since the diagnosis is often difficult and the notifications scarce. To our knowledge, this is the first report describing clinical signs, pathological findings and chromatographic diagnosis. This report aims to contribute to the understanding of the pathogenesis of metaldehyde intoxication, to further explore veterinary forensic toxicology diagnosis.

Wound healing treatment using insulin within polymeric nanoparticles in the diabetes animal model.

The aim of this work was to prepare chitosan nanoparticles containing insulin and to evaluate its therapeutic activity during wound healing in diabetic rats. The hypothesis that guided this study was that the combination of insulin within chitosan nanoparticles could stimulate the signaling pathway for wound healing. The chitosan nanoparticles were prepared by the ionotropic gelation method presenting average size of 183.3 ± 8.32 nm, polydispersity index (PDI) 0.397 ± 0.07 and zeta potential of 33.7 ± 2.45 mV for empty chitosan nanoparticles (EC) and 245.9 ± 25.46 nm and PDI 0.463 ± 0.01, and zeta potential of 39.3 ± 4.88 mV for chitosan nanoparticles containing insulin (IC). The insulin association efficiency was 97.19% ± 2.18. These nanoparticles and free insulin (FI) were incorporated within a hydrogel (Sepigel®) for topical application in the wound of 72 diabetic rats distributed in four groups: Sepigel® (S, control), free insulin (FI), empty chitosan nanoparticles (EC), and chitosan nanoparticles containing insulin (IC). The animals in each group were reorganized into three subgroups (n = 6) to assess their clinical signs after days 3, 7, and 14 from the beginning of treatments. Intense fibroplasias were observed in the free or insulin-chitosan nanoparticles groups. In the latter, a large number of blood vessels were observed at day 7th. Our data indicated that both empty and insulin-containing chitosan nanoparticles were able to stimulate inflammatory cell proliferation, and angiogenesis, followed by wound maturation.

Acute fatal poisoning by spontaneous ingestion of Enterolobium contortisiliquum (Mimosidae) pods in horses.

An outbreak of acute poisoning of horses by Enterolobium contortisiliquum pods is reported in the state of Goiás, Brazil. Three horses presented apathy, hyporexia, prostration, jaundice, recumbency and died in 24-48 hours. The main pathological findings were a yellowish liver with an enhanced lobular pattern, multifocal hepatic necrosis mostly in the midzones of lobules and sometimes with a random distribution across the hepatic lobes and swelling of hepatocytes. E. contortisiliquum trees has a wide distribution in South America and cases of poisoning have not been reported in horses.

Doxorubicin-induced Cardiotoxicity and Cardioprotective Agents: Classic and New Players in the Game.

Doxorubicin (DOX) is a cytostatic antibiotic from the class of anthracyclines widely used in chemotherapeutic cancer treatments. Despite the efficiency against several types of cancer, the use of DOX remains limited due to the side effects, especially cardiotoxicity. Among the DOX administration strategies, there are the "classic players" such as nanoparticles and polymers, which are capable of DOX delivery directly to interesting neoplastic regions. On the other hand, the "new players" such as phytochemicals and probiotics emerged with the proposal to react with DOX free radicals, reducing the oxidative stress, inflammatory and apoptotic process. Thus, this review aims to report the studies involving these classics and new players along the years that focus on improved administration and reduction of DOX-induced cardiotoxicity.