Selective inhibition of interleukin 6 receptor decreased inflammatory cytokines and increased proteases in an experimental model of critical calvarial defect.

Considering the lack of consensus related to the impact of selective IL-6 receptor inhibition on bone remodeling and the scarcity of reports, especially on large bone defects, this study proposed to evaluate the biological impact of the selective inhibitor of interleukin-6 receptor (tocilizumab) in an experimental model of critical calvarial defect in rats. In this preclinical and in vivo study, 24 male Wistar rats were randomly divided into two groups (n=12/group): defect treated with collagen sponge (CG) and defect treated with collagen sponge associated with 2 mg/kg tocilizumab (TCZ). The defect in the parietal bone was created using an 8-mm diameter trephine drill. After 90 days, the animals were euthanized, and tissue samples (skull caps) were evaluated through micro-CT, histological, immunohistochemistry, cytokines, and RT-qPCR analyses. Tocilizumab reduced mononuclear inflammatory infiltration (P<0.05) and tumor necrosis factor (TNF)-α levels (P<0.01) and down-regulated tissue gene expression of BMP-2 (P<0.001), RUNX-2 (P<0.05), and interleukin (IL)-6 (P<0.05). Moreover, it promoted a stronger immunostaining of cathepsin and RANKL (P<0.05). Micro-CT and histological analyses revealed no impact on general bone formation (P>0.05). The bone cells (osteoblasts, osteoclasts, and osteocytes) in the defect area were similar in both groups (P>0.05). Tocilizumab reduced inflammatory cytokines, decreased osteogenic protein, and increased proteases in a critical bone defect in rats. Ninety days after the local application of tocilizumab in the cranial defect, we did not find a significant formation of bone tissue compared with a collagen sponge.

Estimating the burden of care for oral potentially malignant disorders and oral cancer in Brazilian dental practice.

BACKGROUND: Oral cancer (OC) and oral potentially malignant disorders (OPMD) pose significant challenges to public health in Brazil. This study aimed to estimate the prevalence of oral cancer (OC) and oral potentially malignant disorders (OPMD) among patients who would be treated by Brazilian dentists during their careers. MATERIAL AND METHODS: Data on the number of dentists in Brazil were extracted from the 2022 census data, while incidence rates for OC cases were sourced from the Brazilian National Cancer Institute (INCA). Population estimates for Brazil and data on dental check-up rates were obtained from relevant national sources. RESULTS: Our analysis indicates that a general dentist in Brazil can expect to encounter on average two to three OC patients and on average 675 patients with OPMDs over a 35-year career. Regional disparities were observed, with certain regions showing higher than the average number of encounters due to low density of dentists in some rural districts. CONCLUSIONS: Brazilian dentists are likely to confront a substantial number of OPMD cases during their professional tenure, emphasizing the need for public health policies aimed at enhancing dental surgeons' education in oral cancer prevention and early detection.

Bone regeneration driven by a nano-hydroxyapatite/chitosan composite bioaerogel for periodontal regeneration.

The most recent progress in reconstructive therapy for the management of periodontitis and peri-implantitis bone defects has relied on the development of highly porous biodegradable bioaerogels for guided bone regeneration. The objective of this work was to evaluate in vitro the osteoinduction of periodontal-originating cells (human dental follicle mesenchymal cells, DFMSCs) promoted by a nano-hydroxyapatite/chitosan (nHAp/CS) bioaerogel, which was purified and sterilized by a sustainable technique (supercritical CO2). Moreover, the in vivo bone regeneration capacity of the nHAp/CS bioaerogel was preliminarily assessed as a proof-of-concept on a rat calvaria bone defect model. The quantification of DNA content of DFMSCs seeded upon nHAp/CS and CS scaffolds (control material) showed a significant increase from the 14th to the 21st day of culture. These results were corroborated through confocal laser scanning microscopy analysis (CLSM). Furthermore, the alkaline phosphatase (ALP) activity increased significantly on the 21st day, similarly for both materials. Moreover, the presence of nHAp promoted a significantly higher expression of osteogenic genes after 21 days when compared to CS scaffolds and control. CLSM images of 21 days of culture also showed an increased deposition of OPN over the nHAp/CS surface. The in vivo bone formation was assessed by microCT and histological analysis. The in vivo evaluation showed a significant increase in bone volume in the nHAp/CS test group when compared to CS and the empty control, as well as higher new bone formation and calcium deposition within the nHAp/CS structure. Overall, the present study showed that the nHAp/CS bioaerogel could offer a potential solution for periodontal and peri-implant bone regeneration treatments since the in vitro results demonstrated that it provided favorable conditions for DFMSC proliferation and osteogenic differentiation, while the in vivo outcomes confirmed that it promoted higher bone ingrowth.

Head and neck myofibroma: A case series of 16 cases and literature review.

BACKGROUND: This study aimed to explore the clinical, histopathologic, and immunohistochemical characteristics of myofibromas (MFs) affecting the head and neck region. MATERIAL AND METHODS: Formalin-fixed paraffin-embedded tissue blocks of patients diagnosed with MFs in the head and neck were retrieved from the archives of three oral and maxillofacial pathology laboratories. Data including clinical, radiographic, microscopic and immunohistochemical findings, treatment employed, and follow-up status were retrieved from the patient's medical records or pathology reports. RESULTS: Sixteen cases were included in the study. Females were slightly more affected than males. The first and second decades of life were more prevalent. The most common locations were the alveolar ridge and cheek. Although rare, some of the patients were presented with intraosseous lesions. Microscopically, tumors consisted of plump, spindle-shaped myofibroblasts arranged in whorls or fascicles with varying degrees of differentiation. Immunohistochemically, diffuse positivity for vimentin and α-SMA was observed, while Ki-67 mostly showed low immunoreactivity (<5%). Treatment primarily involved complete excision. CONCLUSIONS: MFs in the head and neck region are rare and predominantly affect female patients during the second decade of life. Despite their rarity, central MFs should be considered in the differential diagnosis of intraosseous lesions in infants.

A proposed clinical classification for pituitary neoplasms to guide therapy and prognosis.

No comprehensive classification system that guides prognosis and therapy of pituitary adenomas exists. The 2022 WHO histopathology-based classification system can only be applied to lesions that are resected, which represent few clinically significant pituitary adenomas. Many factors independent of histopathology provide mechanistic insight into causation and influence prognosis and treatment of pituitary adenomas. We propose a new approach to guide prognosis and therapy of pituitary adenomas by integrating clinical, genetic, biochemical, radiological, pathological, and molecular information for all adenomas arising from anterior pituitary cell lineages. The system uses an evidence-based scoring of risk factors to yield a cumulative score that reflects disease severity and can be used at the bedside to guide pituitary adenoma management. Once validated in prospective studies, this simple manageable classification system could provide a standardised platform for assessing disease severity, prognosis, and effects of therapy on pituitary adenomas.

Oral cancer screening outcomes in the Latin American region with special relevance to Brazil and Cuba: a systematic review.

BACKGROUND:  The Latin American region represents a hotspot for oral cancer incidence and mortality. To reduce oral cancer mortality rates, screening for early detection of subjects with suspicious or innocuous oral lesions has been promoted. A systematic review was performed to assess the outcomes of oral cancer screening in the Latin American region. MATERIAL AND METHODS:  An electronic search was conducted in eight databases and grey literature. The eligibility criteria included screening where adult participants underwent any screening test during an organized screening program. Screening programs were assessed to understand trends in oral cancer diagnosis. Rates of oral cancers diagnosed in screening programs were classified as increase, decrease, or stable based on each year assessed. RESULTS:  Following our searches, twelve studies conducted in Brazil and Cuba were included. The screening tests reported were visual oral examination (VOE) and in one study in addition light-based fluorescence testing. 13,277,608 individuals were screened and a total of 1,516 oral cancers were detected (0.01%). Only two studies aimed to screen high-risk individuals (smokers and drinkers). Oral cancer cases diagnosed during screening programs were proportionately stable over the years 1997 to 2009 but increased from 2010 to 2021. The fluorescence-associated VOE test demonstrated a sensitivity of 100% and a specificity of 90%. Similarly, the VOE test alone exhibited a sensitivity of 100%, with specificity ranging from 75% to 90%. CONCLUSIONS:  Screening studies conducted in Latin American countries had serious limitations both in methodology (lack of examiner training) and in reporting data (lack of description of clinical categories of screen positives). Capacitation of health workers to perform VOE in well-designed screening programs should be implemented.

Stereotactic radiosurgery for the treatment of a distant recurrence of ependymoma on the optic nerve: illustrative case.

BACKGROUND: Ependymomas rarely disseminate to other central nervous system areas distant from the original site. Stereotactic radiosurgery (SRS) provides high control rates for recurring ependymomas. The treatment of optic nerve tumors carries high morbidity, but SRS is an acceptable option to manage these cases to reduce risks. OBSERVATIONS: The authors report the case of a 31-year-old male with a cervical spinal ependymoma who had a disseminated pattern of recurrence including the optic nerve after initial resection of the cervical lesion. The optic nerve tumor was treated with SRS, and the authors discuss the technical aspects of the treatment and its outcomes. At the last follow-up, the optic nerve tumor was controlled with SRS, and visual function was preserved. LESSONS: High-grade ependymomas such as the one in the presented case can have unpredictable patterns of recurrence. SRS provides excellent control of the distant recurring ependymoma with a low complication profile given the location of the tumor in this case.

Phase I study targeting newly diagnosed grade 4 astrocytoma with bispecific antibody armed T cells (EGFR BATs) in combination with radiation and temozolomide.

PURPOSE: The purpose of this study was to determine the safety, feasibility, and immunologic responses of treating grade 4 astrocytomas with multiple infusions of anti-CD3 x anti-EGFR bispecific antibody (EGFRBi) armed T cells (EGFR BATs) in combination with radiation and chemotherapy. METHODS: This phase I study used a 3 + 3 dose escalation design to test the safety and feasibility of intravenously infused EGFR BATs in combination with radiation and temozolomide (TMZ) in patients with newly diagnosed grade 4 astrocytomas (AG4). After finding the feasible dose, an expansion cohort with unmethylated O6-methylguanine-DNA methyltransferase (MGMT) tumors received weekly EGFR BATs without TMZ. RESULTS: The highest feasible dose was 80 × 109 EGFR BATs without dose-limiting toxicities (DLTs) in seven patients. We could not escalate the dose because of the limited T-cell expansion. There were no DLTs in the additional cohort of three patients with unmethylated MGMT tumors who received eight weekly infusions of EGFR BATs without TMZ. EGFR BATs infusions induced increases in glioma specific anti-tumor cytotoxicity by peripheral blood mononuclear cells (p < 0.03) and NK cell activity (p < 0.002) ex vivo, and increased serum concentrations of IFN-γ (p < 0.03), IL-2 (p < 0.007), and GM-CSF (p < 0.009). CONCLUSION: Targeting AG4 with EGFR BATs at the maximum feasible dose of 80 × 109, with or without TMZ was safe and induced significant anti-tumor-specific immune responses. These results support further clinical trials to examine the efficacy of this adoptive cell therapy in patients with MGMT-unmethylated GBM. CLINICALTRIALS: gov Identifier: NCT03344250.

Systemic therapies for salivary gland carcinomas: an overview of published clinical trials.

BACKGROUND: There is no consensus about effective systemic therapy for salivary gland carcinomas (sgcs). Our aim was summarized the clinical trials assessing the systemic therapies (ST) on sgcs. MATERIAL AND METHODS: Electronic searches were carried out through MEDLINE/pubmed, EMBASE, Scopus, Web of Science, and the Cochrane Library databases, and gray literature. RESULTS: Seventeen different drugs were evaluated, and the most frequent histological subtype was adenoid cystic carcinoma (n=195, 45.5%). Stable disease, observed in 11 ST, achieved the highest rate in adenoid cystic carcinoma treated with sunitinib. The highest complete (11.1%) and partial response (30.5%) rates were seen in androgen receptor-positive tumors treated with leuprorelin acetate. CONCLUSIONS: Despite all the advances in this field, there is yet no effective evidence-based regimen of ST, with all the clinical trials identified showing low rates of complete and partial responses. Further, translational studies are urgently required to characterize molecular targets and effective ST.

Sustainable trehalose lipid production by Rhodotorula sp.: a promising bio-based alternative.

Global environmental concerns drive research toward the development of new eco-friendly compounds to replace pollutant chemicals. This study focuses on optimizing the production of trehalose lipids (TLs), which are glycolipid biosurfactants (BS) with various applications like antimicrobial or surface tension reduction. New microorganism sources, growth conditions, medium composition, purification conditions, and physicochemical properties of TLs are studied. Addressing a microscale approach, TLs production was successfully achieved using Rhodotorula sp. and Rhodococcus erythropolis to compare, with different media compositions including glucose-based and salt media supplemented with glycerol, glucose, n-hexadecane, n-dodecane. Liquid-liquid extraction using ethyl acetate and methanol was employed for compound extraction, followed by characterization using analytical methods such as Thin layer chromatography (TLC), High performance liquid chromatography (HPLC), and UHPLC. The produced TLs exhibited a minimum surface tension of 47 mN/m and a critical micellar concentration of 4.4 mg/mL. This study also identified Rhodotorula sp. as a new sustainable producer of TLs with improved productivity.

Toll-like receptor 9 polymorphisms in brazilian patients with systemic lupus erythematosus: a pilot study / Polimorfismos do receptor toll-like 9 em pacientes brasileiros com lúpus eritematoso sistêmico: um estudo piloto

Toll-like receptor 9 (TLR9) is an important component of the innate immune system and have been associated with several autoimmune diseases, such as Systemic Lupus Erythematosus (SLE). The aim of this study was to investigate polymorphisms in TLR9 gene in a Brazilian SLE patients group and their association with clinical manifestation, particularly Jaccoud’s arthropathy (JA). We analyzed DNA samples from 204 SLE patients, having a subgroup of them presenting JA (n=24). A control group (n=133) from the same city was also included. TLR9 single nucleotide polymorphisms (SNPs) (−1237 C>T and +2848 G>A) were identified by sequencing analysis. The TLR9 gene genotype frequency was similar both in SLE patients and the control group. In the whole SLE population, an association between the homozygosis of allele C at position −1237 with psychosis and anemia (p < 0.01) was found. Likewise, the homozygosis of allele G at position +2848 was associated with a discoid rash (p < 0.05). There was no association between JA and TLR9 polymorphisms. These data show that TLR9 polymorphisms do not seem to be a predisposing factor for SLE in the Brazilian population, and that SNPs are not associated with JA.

O receptor Toll-like 9 (TLR9) é um componente importante do sistema imunológico inato e tem sido associado a várias doenças autoimunes, como o Lúpus Eritematoso Sistêmico (LES). O objetivo deste estudo foi investigar polimorfismos no gene TLR9 em um grupo de pacientes brasileiros com LES e sua associação com a manifestação clínica, particularmente a artropatia de Jaccoud (JA). Foram analisadas amostras de DNA de 204 pacientes com LES, e um subgrupo com JA (n=24). Um grupo de controle (n=133) da mesma cidade também foi incluído. Os polimorfismos de nucleotídeos únicos TLR9 (SNPs) (−1237 C>T e +2848 G>A) foram identificados pela análise de sequenciamento. A frequência do genótipo genético TLR9 foi semelhante tanto em pacientes com LES quanto no grupo controle. Em toda a população de LES, foi encontrada associação entre a homozigose do alelo C na posição −1237 com psicose e anemia (p < 0,01). Da mesma forma, a homozigose do alelo G na posição +2848 foi associada a uma erupção cutânea discoide (p < 0,05). Não houve associação entre polimorfismos JA e TLR9. Esses dados mostram que os polimorfismos TLR9 não parecem ser um fator predisponível para o LES na população brasileira, e que os SNPs não estão associados ao JA.

Toll-like receptor 9 polymorphisms in brazilian patients with systemic lupus erythematosus: a pilot study

Abstract Toll-like receptor 9 (TLR9) is an important component of the innate immune system and have been associated with several autoimmune diseases, such as Systemic Lupus Erythematosus (SLE). The aim of this study was to investigate polymorphisms in TLR9 gene in a Brazilian SLE patients group and their association with clinical manifestation, particularly Jaccouds arthropathy (JA). We analyzed DNA samples from 204 SLE patients, having a subgroup of them presenting JA (n=24). A control group (n=133) from the same city was also included. TLR9 single nucleotide polymorphisms (SNPs) (1237 C>T and +2848 G>A) were identified by sequencing analysis. The TLR9 gene genotype frequency was similar both in SLE patients and the control group. In the whole SLE population, an association between the homozygosis of allele C at position 1237 with psychosis and anemia (p 0.01) was found. Likewise, the homozygosis of allele G at position +2848 was associated with a discoid rash (p 0.05). There was no association between JA and TLR9 polymorphisms. These data show that TLR9 polymorphisms do not seem to be a predisposing factor for SLE in the Brazilian population, and that SNPs are not associated with JA.

Resumo O receptor Toll-like 9 (TLR9) é um componente importante do sistema imunológico inato e tem sido associado a várias doenças autoimunes, como o Lúpus Eritematoso Sistêmico (LES). O objetivo deste estudo foi investigar polimorfismos no gene TLR9 em um grupo de pacientes brasileiros com LES e sua associação com a manifestação clínica, particularmente a artropatia de Jaccoud (JA). Foram analisadas amostras de DNA de 204 pacientes com LES, e um subgrupo com JA (n=24). Um grupo de controle (n=133) da mesma cidade também foi incluído. Os polimorfismos de nucleotídeos únicos TLR9 (SNPs) (1237 C>T e +2848 G>A) foram identificados pela análise de sequenciamento. A frequência do genótipo genético TLR9 foi semelhante tanto em pacientes com LES quanto no grupo controle. Em toda a população de LES, foi encontrada associação entre a homozigose do alelo C na posição 1237 com psicose e anemia (p 0,01). Da mesma forma, a homozigose do alelo G na posição +2848 foi associada a uma erupção cutânea discoide (p 0,05). Não houve associação entre polimorfismos JA e TLR9. Esses dados mostram que os polimorfismos TLR9 não parecem ser um fator predisponível para o LES na população brasileira, e que os SNPs não estão associados ao JA.

Toll-like receptor 9 polymorphisms in brazilian patients with systemic lupus erythematosus: a pilot study / Polimorfismos do receptor toll-like 9 em pacientes brasileiros com lúpus eritematoso sistêmico: um estudo piloto

Abstract Toll-like receptor 9 (TLR9) is an important component of the innate immune system and have been associated with several autoimmune diseases, such as Systemic Lupus Erythematosus (SLE). The aim of this study was to investigate polymorphisms in TLR9 gene in a Brazilian SLE patients group and their association with clinical manifestation, particularly Jaccoud's arthropathy (JA). We analyzed DNA samples from 204 SLE patients, having a subgroup of them presenting JA (n=24). A control group (n=133) from the same city was also included. TLR9 single nucleotide polymorphisms (SNPs) (−1237 C>T and +2848 G>A) were identified by sequencing analysis. The TLR9 gene genotype frequency was similar both in SLE patients and the control group. In the whole SLE population, an association between the homozygosis of allele C at position −1237 with psychosis and anemia (p < 0.01) was found. Likewise, the homozygosis of allele G at position +2848 was associated with a discoid rash (p < 0.05). There was no association between JA and TLR9 polymorphisms. These data show that TLR9 polymorphisms do not seem to be a predisposing factor for SLE in the Brazilian population, and that SNPs are not associated with JA.

Resumo O receptor Toll-like 9 (TLR9) é um componente importante do sistema imunológico inato e tem sido associado a várias doenças autoimunes, como o Lúpus Eritematoso Sistêmico (LES). O objetivo deste estudo foi investigar polimorfismos no gene TLR9 em um grupo de pacientes brasileiros com LES e sua associação com a manifestação clínica, particularmente a artropatia de Jaccoud (JA). Foram analisadas amostras de DNA de 204 pacientes com LES, e um subgrupo com JA (n=24). Um grupo de controle (n=133) da mesma cidade também foi incluído. Os polimorfismos de nucleotídeos únicos TLR9 (SNPs) (−1237 C>T e +2848 G>A) foram identificados pela análise de sequenciamento. A frequência do genótipo genético TLR9 foi semelhante tanto em pacientes com LES quanto no grupo controle. Em toda a população de LES, foi encontrada associação entre a homozigose do alelo C na posição −1237 com psicose e anemia (p < 0,01). Da mesma forma, a homozigose do alelo G na posição +2848 foi associada a uma erupção cutânea discoide (p < 0,05). Não houve associação entre polimorfismos JA e TLR9. Esses dados mostram que os polimorfismos TLR9 não parecem ser um fator predisponível para o LES na população brasileira, e que os SNPs não estão associados ao JA.

Evaluation of the immunomodulatory activity of thalidomide on tumor-associated macrophages in the 4T1 murine metastatic breast cancer model / [Avaliação do efeito imunomodulador da talidomida em macrófagos associados a tumores no modelo murino de câncer de mama metastático 4T1]

The present work evaluated the immunomodulatory effect of thalidomide (Thal) at different doses on tumor-associated macrophages (TAMs) using a mouse model of human breast cancer. Mice were inoculated with 4T1 cells in the left flank and treated with Thal once a day at concentrations of 50, 100, and 150mg/kg body weight from the 5th day until the 28th day of tumor inoculation. The tumors were sized, proliferation index and TAMs count were evaluated in primary tumors and metastatic lungs. In addition, the metastasis rate was evaluated in the lungs. Thal at 150mg/kg significantly decreased tumor growth, proliferation index, and TAMs infiltration in primary tumors. Conversely, a higher number of TAMs and lower proliferation index were observed in metastatic lungs in mice treated with 150mg/kg of Thal. Furthermore, Thal at 150mg/kg significantly decreased the metastatic nodules in the lungs. Our findings demonstrated that Thal treatment considerably decreased the primary tumor and lung metastasis in mice associated with different TAM infiltration effects in these sites.(AU)

No presente trabalho, foi avaliado o efeito imunomodulador de diferentes doses de talidomida em macrófagos associados ao tumor (TAMs), em um modelo murino de câncer de mama. Camundongos foram inoculados com células 4T1, na região do flanco esquerdo, e tratados com talidomida, uma vez ao dia, nas doses de 50, 100 e 150mg/k, por massa corporal, do quinto dia ao 28º dia de inoculação tumoral. Os tumores foram medidos, o índice de proliferação celular e a contagem de TAMs foram avaliados nos tumores primários e nos pulmões com metástases. Além disso, a taxa de metástases pulmonares também foi avaliada. A talidomida na dose de 150mg/kg diminuiu significativamente o crescimento tumoral, o índice de proliferação celular e a infiltração de TAMs nos tumores primários. Por outro lado, maior número de TAMs e menor índice de proliferação celular foram observados nos pulmões metastáticos, em camundongos tratados com 150mg/kg de talidomida. Ademais, a talidomida na dose de 150mg/kg diminuiu significativamente os nódulos metastáticos nos pulmões. Os resultados demonstraram que o tratamento com talidomida diminuiu o crescimento tumoral e as metástases pulmonares em camundongos, associado com diferentes efeitos na infiltração de TAMs nesses locais.(AU)

Melittin-induced metabolic changes on the Madin-Darby Bovine Kidney cell line / [Mudanças metabólicas induzidas por melitina em células da linhagem Madin-Darby Bovine Kidney]

In this study, the toxic effects of melittin on Madin-Darby Bovine Kidney cells (MDBK) were analyzed with respect to mitochondrial functionality by reduction of MTT and flow cytometry, apoptosis potential, necrosis, oxygen reactive species (ROS) production, lipid peroxidation, and DNA fragmentation using flow cytometry and cell membrane destabilization by confocal microscopy. The toxicity presented dose-dependent characteristics and mitochondrial activity was inhibited by up to 78.24 ±3.59% (P<0.01, n = 6) in MDBK cells exposed to melittin (10µg/mL). Flow cytometry analysis revealed that melittin at 2µg/mL had the highest necrosis rate (P<0.05) for the cells. The lipoperoxidation of the membranes was also higher at 2µg/mL of melittin (P<0.05), which was further confirmed by the microphotographs obtained by confocal microscopy. The highest ROS production occurred when the cells were exposed to 2.5µg/mL melittin (P<0.05), and this concentration also increased DNA fragmentation (P<0.05). There was a significative and positive correlation between the lipoperoxidation of membranes with ROS (R=0.4158), mitochondrial functionality (R=0.4149), and apoptosis (R=0.4978). Thus, the oxidative stress generated by melittin culminates in the elevation of intracellular ROS that initiates a cascade of toxic events in MDBK cells.(AU)

Neste estudo, os efeitos tóxicos da melitina em células Madin-Darby Bovine Kidney (MDBK) foram analisados quanto à funcionalidade mitocondrial, por redução de MTT e citometria de fluxo, potencial de apoptose, necrose, produção de espécies reativas de oxigênio (ROS), peroxidação lipídica e fragmentação de DNA, utilizando-se citometria de fluxo e desestabilização da membrana celular, por microscopia confocal. A toxicidade apresentou características dose-dependentes e a atividade mitocondrial foi inibida até 78,24±3,59% (P<0,01, n = 6) em células MDBK expostas à melitina (10µg/mL). Análises por citometria de fluxo revelaram que a melitina a 2µg/mL apresentou o maior índice necrótico celular (P<0,05). A maior lipoperoxidação de membranas também foi na concentração de 2µg/mL de melitina (P<0,05), o que foi posteriormente confirmado por microscopia confocal. A maior produção de ROS aconteceu quando as células foram expostas a 2,5µg/mL de melitina (P<0,05), e essa concentração também aumentou a fragmentação de DNA (P<0,05). Houve uma significativa correlação positiva entre a lipoperoxidação de membranas e a produção de ROS (R=0,4158), funcionalidade mitocondrial (R=0,4149) e apoptose (R=0,4978). Portanto, o estresse oxidativo gerado pela melitina culminou na elevação de ROS intracelular, que inicia uma cascata de eventos tóxicos nas células MDBK.(AU)

Influence of urban landscape on ants and spiders richness and composition in forests

As large amounts of natural environments are lost due to urbanization, the role of remnant native vegetation in the preservation of biodiversity has become even more significant. Remnant native forest patches are essential refugia for flora and fauna and are crucial for the maintenance of ecosystem processes in urbanized landscapes. We evaluated the influence of landscape structure on ants and spiders associated with Atlantic Forest remnants in urban landscapes. We sampled 14 forest areas in the Metropolitan Region of Salvador and tested the effect of the landscapes’ proportion of forest cover, mean landscape isolation, and mean landscape shape complexity on the taxonomic and functional richness and the community composition of both groups. The species collected were classified into functional groups based on behavioral attributes and environmental preferences. Overall, there were strong adverse effects of forest loss, decreased connectivity, and an increase in edge effects associated with the mean shape complexity of the forest remnants. However, the spiders responded to all three landscape structure characteristics whereas the ants only responded to the landscape mean shape complexity. Our findings indicate that the maintenance of urban forest habitats is essential for the conservation of biodiversity in the Metropolitan Region of Salvador and the preservation of ecological functions performed by species within the forest areas.

Apamin-induced alterations in J774 1. 6 macrophage metabolism / [Alterações induzidas por apamina no metabolismo de macrófagos J774 1. 6]

Among the immune system cells, macrophages have an important role. Apamin, a bee venom constituent, is important in the defense of these insects. Thus, we aimed to evaluate the metabolism of J774 1.6 macrophage cell line when exposed to isolated and purified apamin, using cytotoxicity tests by MTT reduction and analysis by flow cytometry (apoptosis / necrosis, production of reactive oxygen species (ROS), membranous lipoperoxidation (LPO), electrical potential of the mitochondrial membrane (mMP) and DNA fragmentation). None of the tested concentrations (10 to 100µg/mL) were cytotoxic according to MTT reductions. Apoptosis rates decreased at concentrations of 2.5, 5.0, and 10.0µg/mL (P<0.05), while necrosis rates increased (P<0.05). However, rates of healthy cells at the highest tested concentration (10µg/mL) did not differ from control (P>0.05). Apamin did not alter ROS, LPO, or DNA fragmentation. Therefore, all analyzed concentrations (1.25 to 10µg/mL) decreased mMP. Such decrease in apoptosis might be due to a suppression of mitochondrial pro-apoptotic messengers, as this peptide causes no oxidative stress, lipid peroxidation, and DNA damage. Highly sensitive techniques are majorly important for proper interpretation of cellular toxicity mechanisms, combined with routine laboratory methods.(AU)

Das células do sistema imunológico, macrófagos desempenham um papel fundamental. Apamina, constituinte do veneno de abelhas, é importante na defesa destas. Objetivou-se avaliar o metabolismo da linhagem de macrófagos J774 1.6 expostos à apamina isolada e purificada, avaliando-se citotoxicidade por redução de MTT e análise por citometria de fluxo (apoptose / necrose, produção de espécies reativas de oxigênio (EROs), lipoperoxidação membranosa (LPO), potencial elétrico da membrana mitocondrial (MMP) e fragmentação do DNA). Nenhuma concentração testada (10 a 100µg / mL) foi citotóxica. As taxas de apoptose diminuíram nas concentrações 2,5, 5,0 e 10,0µg / mL (P<0,05), enquanto as de necrose aumentaram (P<0,05). Entretanto, as taxas de células saudáveis na maior concentração testada (10µg / mL) não diferiram do controle (P>0,05). A apamina não alterou as ERO, a LPO nem a fragmentação do DNA. Portanto, todas as concentrações analisadas (1,25 a 10µg / mL) diminuíram a mMP. Tal diminuição na apoptose pode ser por uma supressão de mensageiros pró-apoptóticos mitocondriais, já que este peptídeo não causa estresse oxidativo, peroxidação lipídica nem dano ao DNA. Técnicas altamente sensíveis são importantes para adequada interpretação dos mecanismos de citotoxicidade.(AU)