Brazilian Journal of Medical and Biological Research最新文献

Escherichia coli is a common intestinal microorganism that can cause a variety of diseases in humans and animals. The aim of this study was to evaluate the therapeutic effects of fish oil rich in omega-3 against intestinal infection caused by enteroaggregative E. coli (EAEC). Minimum inhibitory and bactericidal concentrations were determined, along with toxicity assays using HT-29 intestinal cells and Tenebrio molitor larvae. Swiss mice infected with EAEC 042 were used to assess the in vivo therapeutic potential of fish oil. Histological analyses of the liver, kidney, and colon were conducted to identify tissue alterations such as inflammation and necrosis. Fish oil exhibited a bacteriostatic effect on E. coli and was non-toxic to HT-29 cells at concentrations up to 50 mg/mL. It also enhanced survival in treated larvae. In infected mice, bacterial colony counts were significantly lower in the fish oil-treated group. Histological evaluation showed reduced inflammatory infiltrates in the liver and colon, and no progression of hepatic hydropic degeneration was observed in treated animals, unlike in the untreated infected group. These findings indicated that fish oil rich in omega-3 possesses antimicrobial activity against E. coli, is non-toxic to both cells and animal models, and effectively reduces intestinal infection and associated tissue damage in mice. This suggests its potential as a supportive therapeutic agent for infections caused by pathogenic E. coli.

Fractal analysis (FA) of neutrophils has demonstrated potential in identifying changes in chromatin associated with clinical parameters in individuals with chronic diseases. Therefore, this study aimed to investigate FA of neutrophils' nuclei from patients with Trypanosoma cruzi and/or HIV. Fifty-three individuals were recruited and divided into four groups: T. cruzi-infected patients with chronic chagasic cardiomyopathy (CCC) (n=18), seropositive HIV individuals (SPHIV) (n=14), T. cruzi-HIV coinfected patients (n=9), and healthy individuals (n=12). Micrographs of neutrophils underwent FA using a box-counting method in the ImageJ software. Clinical parameters obtained from patients' medical records, such as left ventricle mass index (LVMI), left ventricle ejection fraction (LVEF), risk of ischemic stroke (IS), and sudden death were analyzed. FA was lower in patients compared to the control group (P<0.0001). Chagas disease (CD) patients showed higher FA when the LVEF was higher (r=0.53), which increased the risk of sudden death (r=-0.62). In SPHIV, when FA was higher, T CD4+ lymphocyte count was also higher (r=0.66) and the T CD8+ lymphocyte count was lower (r=-0.54). Coinfected individuals showed higher FA, when LVEF (r=0.60), neutrophil to lymphocyte ratio (r=0.80), total lymphocytes (r=0.70), and T CD4+ lymphocyte count (r=0.70) were increased, and T CD8+ lymphocyte count was decreased (r=-0.70). FA was an independent marker of changes in neutrophil chromatin and has proven to be a prognostic tool and a method for risk stratification for adverse events, survival, and mortality in individuals infected with T. cruzi and/or HIV.

Helicobacter pylori is an infectious agent linked to significant gastric pathologies, which makes it a public health concern. The enzyme-linked immunosorbent assay (ELISA) is widely used for epidemiological studies and for investigating virulence factors like the cagA gene. Due to the varying antigenic profiles of bacterial strains across different populations, the local validation of serological tests is essential. This study aimed to evaluate the performance of two commercial serological tests - the MyBiosource HP-CagA-IgG ELISA kit and the Sunlong Human IgG (CagA-IgG) ELISA kit - in detecting the cagA virulence factor and to assess its prevalence in bacterial isolates from a population in the southwest region of Bahia. A total of 88 individuals were enrolled, and 34 tested positive for the cagA factor via real-time PCR. After establishing customized cutoff points, the MyBiosource kit demonstrated a sensitivity of 55.88%, specificity of 50%, and accuracy of 52.22%, while the Sunlong kit showed a sensitivity of 70.59%, specificity of 60%, and accuracy of 64.29%. Despite these results, neither test met satisfactory performance standards, with sensitivity below 75% and specificity ranging from 50 to 60%. The overall prevalence of H. pylori infection was 56.8%, with a cagA prevalence of 68% among positive cases. Further investigations using additional commercial tests are recommended to enhance diagnostic outcomes for this population.

Candida biofilm is difficult to control due to the poor penetration and unspecificity of antifungal drugs against the microorganisms associated with this structure. Nanoparticles have been investigated for their antimicrobial potential. In this context, the present study evaluated the antibiofilm activity of silver nanoparticle colloids (AgNPs) against candida isolated from the oral cavity. AgNPs were prepared in two different ethanolic syntheses - without and with ammonium hydroxide: AgNP-1 and AgNP-2, respectively. AgNPs were characterized by atomic absorption spectroscopy (AAS), UV-visible (UV-vis) absorption electron spectroscopy, zeta potential, dynamic light scattering (DLS), and transmission electron microscopy (TEM). Subsequently, they were evaluated against biofilm formation by clinical isolates of Candida albicans and Candida krusei by determining the minimum inhibitory concentration (MIC), minimum fungicidal concentration (MFC), and minimum biofilm formation inhibitory concentration (MBIC50). AgNPs inhibited biofilm formation of tested C. albicans and C. krusei and showed antibiofilm activity at subinhibitory concentrations against all yeasts. AgNP-1 inhibited biofilm formation at concentrations between 7.55 and 60.46 µg/mL and AgNP-2 between 7.71 and 30.80 µg/mL. The characterization of AgNP showed that AgNP-1 and AgNP-2 differ mainly in size and dispersion, with AgNP-2 being monodisperse, indicating that these characteristics could be related to the activity against the formation of C. albicans and C. krusei biofilm, and the silver nanoparticles may represent innovative and complementary alternatives to the available antifungal arsenal.

We have previously demonstrated that different modalities of endurance exercise combined with lower muscle glycogen content elicit several physiological and molecular benefits in men. In this study, we hypothesized that these exercise strategies modulate monocarboxylate transporters (MCTs) and plasma lactate. We investigated MCT1 and MCT4 gene expression after two forms of exercise (i.e., once daily and twice-a-day) under low carbohydrate (CHO) availability (Acute - Study 1) and whether three weeks under once daily or twice-a-day training differentially affected plasma lactate during exercise (Chronic - Study 2). In Study 1, five participants performed a high-intensity interval exercise (HIIE) 2 h (twice-a-day) or 15 h (once daily) after exercise and diet manipulations to reduce endogenous CHO stores or without previous CHO manipulation (Control). Muscle biopsies were collected before, right after, and 3 h after HIIE. In Study 2, plasma lactate was measured during a graded exercise test before and after three weeks of once-daily (n=7) or twice-a-day training (n=7). MCT1 gene expression increased from before to after and 3-h post-HIIE only in the twice-a-day exercise (P<0.05). MCT4 gene expression was unaltered in all conditions (P>0.05). The plasma lactate curve shifted to the right in both training approaches, without differences in lactate slope reduction between once-daily (-0.49±0.58 mmol·L-1·min-1) and twice-a-day (-0.46±0.73 mmol·L-1·min-1) exercise. In conclusion, twice-a-day training increased acute MCT1 gene expression but did not result in chronic changes in plasma lactate response during exercise.

Chronic use of glucocorticoids is one of the most common causes of osteoporosis. Triterpenes have a positive effect on bone metabolism, which encourages research into the anti-resorptive properties of these natural compounds. In this study, the anti-resorptive effect of the semisynthetic compound 3β,6β,16β-tripropionyloxylup-20(29)-ene (CL-P2), obtained from the natural lupane-type triterpene 3β,6β,16β-trihydroxylup-20(29)-ene (CL-1) isolated from Combretum leprosum Mart., was investigated in a glucocorticoid-induced osteoporosis (GIO) model in rats. GIO was induced by dexamethasone (7 mg/kg, im; 1×/week, 65 days). On the 36th day, treatment was started (gavage) with CL-P2 (0.01 or 0.1 mg/kg; 30 days). After this time interval, the rats were euthanized and the femurs and lumbar vertebrae were collected for analysis by microcomputed tomography (micro-CT), quantity and type of collagen (Picrosirius Red), micro-Raman spectrometry, and histomorphometric analysis using hematoxylin and eosin (H&E) staining. The organs were collected for toxicity analysis (HE). CL-P2 increased trabecular volume, number of trabeculae and bone mineral density as evidenced by micro-CT analysis in the third lumbar vertebra (L3), as well as the amount of total collagen and type I collagen in L2. In the analysis of the femurs, CL-P2 promoted an increase in the number of osteoblasts and osteocytes and a reduction in the number of osteoclasts, as well as change in the mineral composition of these bones, suggested by the increase in the carbonate-to-phosphate ratio (CTPR) identified by micro-Raman spectrometry. Histopathological analysis of the organs revealed the pre-clinical safety of CL-P2. CL-P2 had bone-protective benefits and may be a biotechnologically viable product as a supplemental therapy for GIO.

Sepsis is a life-threatening organ dysfunction with a high incidence rate and mortality. The aim of this study was to investigate monocyte-related signaling pathways and hub genes in sepsis survivors and non-survivors. Sepsis-related data were downloaded from Gene Expression Omnibus (GEO) database. Cell annotation and cell communication analysis were performed to identify signaling pathways and ligand-receptor pairs related to monocytes. Immune cell infiltration, functional annotation, differential expression, and correlation analysis were performed to screen for hub genes associated with monocytes. In addition, survival analysis, transcription factors, and drug prediction were also performed on the hub genes. Compared with sepsis survivors, monocytes decreased in sepsis non-survivors. Cell communication results showed that monocytes were also the main signal transmitters and receivers in both the sepsis survivor and the sepsis non-survivor groups. A total of 25 signaling pathways related to monocytes were identified, such as MIF, ANNEXIN, GALECTIN, THBS, ITGB2, CCL, MHC-I, MHC-II, CD23, ICAM, and SEMA4. Subsequently, 6 hub genes (CCR1, CD4, CD47, ITGAX, LILRB1, and PLXNB2) associated with monocytes were identified. Univariate Cox analysis showed that CD4, ITGAX, LILRB1, PLXNB2, and age were associated with the prognosis of sepsis. Multivariate Cox analysis showed that ITGAX and age might be independent prognostic factors for sepsis. ITGAX and CD4 are associated with transcription factors SPI1 and MYB, respectively. Moreover, drug prediction results showed that tregalizumab was an agonist of CD4. This study revealed the monocyte-associated signaling pathways and hub genes, which may contribute to the understanding of the molecular mechanisms of sepsis survivors and non-survivors.

SARS-CoV-2, the causative agent of the COVID-19 pandemic, remains a significant threat to global public health. Therefore, rapid and accurate detection of the virus continues to be of critical importance. Among the specific gene regions of SARS-CoV-2, the Nucleocapsid (N) protein gene is one of the most frequently targeted for viral identification, with NIID_2019-nCOV_N being a notable example. While reverse transcriptase polymerase chain reaction (RT-PCR) remains the gold standard for diagnosis, alternative molecular detection methods are still limited. In this study, a lateral flow assay (LFA) was developed for the detection of a conserved gene region within NIID_2019-nCOV_N. Gold nanoparticles (AuNPs) were employed to enable visual detection, and the assay was designed based on nucleic acid hybridization principles. Two different membrane types (M17 and M12), three oligonucleotide probe concentrations (2, 4, and 8 µM) conjugated to AuNPs, and the assay's limit of detection (LOD) were evaluated. The target sequence from NIID_2019-nCOV_N was successfully detected by the naked eye within 5-6 min. No significant differences in performance were observed between the two membrane types across all probe concentrations, and the LOD was determined to be 1 pM. Consequently, the nucleic acid-based lateral flow assay (NABLFA) designed in this study, which targets a specific conserved base sequence, demonstrated high potential for rapid and sensitive molecular detection of SARS-CoV-2. Furthermore, this approach may be adapted for the identification of emerging viral variants or future outbreaks.

Satellite glial cells (SGCs) within the dorsal root ganglion (DRG) possess the potential for transdifferentiation. Our previous study (doi: 10.1007/s12257-019-0317-x) has identified lncRNA ENSRNOT00000087717 (lnc87717) and its target AKT1 as potential regulators in the differentiation process of DRG-SGCs. In this study, the cell morphology of SGCs was assessed using immunofluorescence cytochemistry during the differentiation following knockdown of lnc87717, as well as downregulation or upregulation AKT1. The subcellular localization of lnc87717 was visualized by fluorescence in situ hybridization (FISH). The mRNA expression levels of lnc87717, AKT1, BDNF, TrkB, proBDNF, and p75NTR were assessed using qRT-PCR. For the in vivo study, 27 male Sprague-Dawley rats aged 6-9 weeks were used to establish the sciatic nerve injury model. The number of apoptotic cells in DRGs was subsequently detected in the AKT1 inhibitor, activator, and control group after the administration of proBDNF antiserum. In vitro, following knockdown of lnc87717, there was a significant decrease in the expression levels of proBDNF, BDNF, TrkB, and p75NTR (P<0.05). Furthermore, the number of nestin-positive SGCs and the expression of lnc87717 and AKT1 were increased in the AKT1-activated group (P<0.05). In vivo, compared to the control group, the number of apoptotic cells in the DRG was increased in the AKT1-inhibited group. Additionally, the expressions of lnc87717 and AKT1 were significantly upregulated (P<0.05), whereas the expression levels of PI3K, NF-κB, and Bad were significantly downregulated (P<0.05) in DRGs following AKT1 up-regulation compared to those in the control group. The differentiation of DRG-SGCs is suggested to be mediated through the activation of AKT1, while lnc87717 downregulates AKT1.

This study aimed to analyze the compromised cortical and subcortical brain structures and quantify the volume of ischemic lesions in patients with hemispatial neglect after stroke treated with transcranial direct current stimulation (tDCS). This cross-sectional study was conducted using data from the ELETRON Trial. Computed tomography (CT) images of 23 patients who underwent anodal tDCS (A-tDCS), cathodal tDCS (C-tDCS), or placebo (sham-tDCS) were included. Lesion mapping based on high-resolution volumetric CT images was performed using an automated anatomical labeling atlas. The proportion of damage in each region and brain damage between groups were compared using chi-squared and Fisher's exact tests. The behavioral inattention test (BIT-C) score was significantly higher in the C-tDCS group than in sham-tDCS group (P=0.03). Gray matter analysis revealed that lesion extension in the A-tDCS group was 325.580 mm3, in C-tDCS was 231.700 mm3, and in the sham-tDCS was 241.574 mm3. The lesion extension in the white matter was 37.076 mm3 in the A-tDCS group, 22.258 mm3 in the C-tDCS group, and 40.556 mm3 in the sham-tDCS, all centered on the superior longitudinal fasciculus. Overall, the A-tDCS group presented with a larger lesion area in the gray matter than the C-tDCS group (P=0.046). The C-tDCS group showed a smaller proportion of areas with white matter damage than the A-tDCS (P=0.011) and S-tDCS (P=0.002) groups. Hemispatial neglect was significantly improved after C-tDCS; however, the extent of gray and white matter damage was smaller for this group.