Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 361
Filter
1.
Braz J Med Biol Res ; 57: e13234, 2024.
Article in English | MEDLINE | ID: mdl-38716980

ABSTRACT

Patients undergoing chemotherapy with cisplatin commonly present gastrointestinal effects such as constipation and gastric emptying (GE) delay. Both the purinergic system and physical exercise modulate the gastrointestinal (GI) tract. In the current study, we investigated the role of ATP, physical exercise, and P2X7 receptor blocking on GE delay induced by cisplatin in rats. Male rats were divided into the following groups: control (C), cisplatin (Cis), exercise (Ex), Brilliant Blue G (BBG), ATP, Cis+Ex, Cis+ATP, Cis+BBG, Cis+Ex+BBG, Cis+Ex+BBG+ATP, and Cis+ATP+BBG. GE delay was induced by treatment with 1 mg/kg cisplatin (1 time/week for 5 weeks, ip). The moderate physical exercise was swimming (1 h/day, 5 days/week for 5 weeks). At the end of the treatment or exercise and 30 min before the GE assessment, some groups received BBG (50 mg/kg, sc) or ATP (2 mg/kg, sc). Then, GE was assessed after a 10-min postprandial period. Chronic use of Cis decreased GE delay (P<0.05) compared to the control group. Both exercise and ATP prevented (P<0.05) GE delay compared to Cis. The pretreatment with BBG significantly inhibited (P<0.05) the effect of exercise and ATP. On the other hand, the association between exercise and ATP reversed (P<0.05) the effect of the BBG and prevented GE delay. Therefore, we suggest that both exercise and treatment with ATP activate P2X7 receptors and prevent GE delay induced by cisplatin in rats.


Subject(s)
Adenosine Triphosphate , Antineoplastic Agents , Cisplatin , Gastric Emptying , Physical Conditioning, Animal , Rats, Wistar , Receptors, Purinergic P2X7 , Animals , Cisplatin/pharmacology , Male , Adenosine Triphosphate/metabolism , Gastric Emptying/drug effects , Gastric Emptying/physiology , Receptors, Purinergic P2X7/metabolism , Physical Conditioning, Animal/physiology , Antineoplastic Agents/pharmacology , Rats , Purinergic P2X Receptor Antagonists/pharmacology
2.
Mol Phylogenet Evol ; 195: 108046, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38447924

ABSTRACT

The global decline of freshwater mussels and their crucial ecological services highlight the need to understand their phylogeny, phylogeography and patterns of genetic diversity to guide conservation efforts. Such knowledge is urgently needed for Unio crassus, a highly imperilled species originally widespread throughout Europe and southwest Asia. Recent studies have resurrected several species from synonymy based on mitochondrial data, revealing U. crassus to be a complex of cryptic species. To address long-standing taxonomic uncertainties hindering effective conservation, we integrate morphometric, phylogenetic, and phylogeographic analyses to examine species diversity within the U. crassus complex across its entire range. Phylogenetic analyses were performed using cytochrome c oxidase subunit I (815 specimens from 182 populations) and, for selected specimens, whole mitogenome sequences and Anchored Hybrid Enrichment (AHE) data on âˆ¼ 600 nuclear loci. Mito-nuclear discordance was detected, consistent with mitochondrial DNA gene flow between some species during the Pliocene and Pleistocene. Fossil-calibrated phylogenies based on AHE data support a Mediterranean origin for the U. crassus complex in the Early Miocene. The results of our integrative approach support 12 species in the group: the previously recognised Unio bruguierianus, Unio carneus, Unio crassus, Unio damascensis, Unio ionicus, Unio sesirmensis, and Unio tumidiformis, and the reinstatement of five nominal taxa: Unio desectusstat. rev., Unio gontieriistat. rev., Unio mardinensisstat. rev., Unio nanusstat. rev., and Unio vicariusstat. rev. Morphometric analyses of shell contours reveal important morphospace overlaps among these species, highlighting cryptic, but geographically structured, diversity. The distribution, taxonomy, phylogeography, and conservation of each species are succinctly described.


Subject(s)
Unio , Animals , Phylogeny , Phylogeography , Unio/genetics , Europe , DNA, Mitochondrial/genetics , Genetic Variation
3.
Braz. j. med. biol. res ; 57: e13234, fev.2024. graf
Article in English | LILACS-Express | LILACS | ID: biblio-1557319

ABSTRACT

Patients undergoing chemotherapy with cisplatin commonly present gastrointestinal effects such as constipation and gastric emptying (GE) delay. Both the purinergic system and physical exercise modulate the gastrointestinal (GI) tract. In the current study, we investigated the role of ATP, physical exercise, and P2X7 receptor blocking on GE delay induced by cisplatin in rats. Male rats were divided into the following groups: control (C), cisplatin (Cis), exercise (Ex), Brilliant Blue G (BBG), ATP, Cis+Ex, Cis+ATP, Cis+BBG, Cis+Ex+BBG, Cis+Ex+BBG+ATP, and Cis+ATP+BBG. GE delay was induced by treatment with 1 mg/kg cisplatin (1 time/week for 5 weeks, ip). The moderate physical exercise was swimming (1 h/day, 5 days/week for 5 weeks). At the end of the treatment or exercise and 30 min before the GE assessment, some groups received BBG (50 mg/kg, sc) or ATP (2 mg/kg, sc). Then, GE was assessed after a 10-min postprandial period. Chronic use of Cis decreased GE delay (P<0.05) compared to the control group. Both exercise and ATP prevented (P<0.05) GE delay compared to Cis. The pretreatment with BBG significantly inhibited (P<0.05) the effect of exercise and ATP. On the other hand, the association between exercise and ATP reversed (P<0.05) the effect of the BBG and prevented GE delay. Therefore, we suggest that both exercise and treatment with ATP activate P2X7 receptors and prevent GE delay induced by cisplatin in rats.

4.
Pathol Res Pract ; 253: 154965, 2024 Jan.
Article in English | MEDLINE | ID: mdl-38039740

ABSTRACT

INTRODUCTION: Esophageal cancer is an extensive public health issue worldwide, warranting the search for biomarkers related to its risk and progression. Previous studies have indicated an association between Val16AlaSOD2 single nucleotide polymorphism in the gene encoding the enzyme superoxide dismutase 2 and esophageal cancer. However, further investigations are needed to clarify its role in disease risk and progression. OBJECTIVE: To investigate the role of Val16AlaSOD2-SNP in esophageal cancer progression and in the survival of patients METHODS: Tumor samples were utilized for Val16Ala-SNP genotyping, while SOD2 expression levels in tissue were assessed using immunohistochemistry. A SOD2 Val16Ala-SNP database was used to obtain information on the genotype of healthy individuals. Risk and overall survival analyzes were performed. RESULTS: The Val16Ala SNP was associated with an increased risk of esophageal cancer (RR 2.18, 95%CI 1.23-3.86), regardless of age and gender, but did not have a significant effect on patient survival. In contrast, weak SOD2 expression demonstrated a significantly associated with poor overall survival after treatment, independent of other clinicopathological variables (HR, 0.41; 95% CI, 0.22-0.79 P = 0.007). CONCLUSIONS: Val16Ala SNP was positively associated with esophageal cancer, and the expression of SOD2 was an independent prognostic marker.


Subject(s)
Esophageal Neoplasms , Polymorphism, Single Nucleotide , Humans , Immunohistochemistry , Superoxide Dismutase/genetics , Genotype , Prognosis , Esophageal Neoplasms/genetics
5.
Article in English | MEDLINE | ID: mdl-38083304

ABSTRACT

Mortality from stroke remains high in Australia, especially for patients located outside the metropolitan cities. This is because they have limited access to specialized stroke facilities for optimal stroke treatment. Mobile stroke units have the capability to take CT scanners out to the patient however current CT commercial scanner designs are large and heavy. As such, this paper aims to design and develop a lightweight CT scanner for use in a mobile stroke unit (either road-based or air-based ambulance) to bring healthcare solution to patients in the rural and remote areas. We used the engineering design optimization approach to redesign and reduce the weight of the existing CT scanner with without compromised it structural performance. We managed to reduce the weight the CT scanner by three-fold while reducing design costs by allowing numerous simulations to be performed using computer software to achieve our design goals. The results are not only useful to optimize CT scanner structure to retrofit on a mobile stroke unit, but also bring the medical device solution to the market and support scalable solution to the larger community. Such an advance will allow for improved equity in healthcare whereby patients can be treated irrespective of location.


Subject(s)
Stroke , Humans , Stroke/diagnostic imaging , Mobile Health Units , Tomography Scanners, X-Ray Computed , Tomography, X-Ray Computed/methods , Technology
6.
Toxics ; 11(12)2023 Dec 11.
Article in English | MEDLINE | ID: mdl-38133414

ABSTRACT

Nowadays, there is an increased consumption of plant-based protein beverages like soy beverages (SBs) as substitutes for cow milk (CM). Both accumulate toxic metals like lead (Pb), cadmium (Cd), and manganese (Mn), which, although essential, are neurotoxic at high levels. Metals can also perturb the normal development of children. This work aimed to evaluate these metal concentrations in CM and SB purchased on the Portuguese market. After validation of the method, linearity of calibration curves, work range, detection and quantification limits, and selectivity, metals were determined in 14 CM and 14 SB brands using atomic absorption spectrometry. The values were compared between CM and SB and with permissible limit values. Soy beverages had significantly (p < 0.05) higher concentrations of Cd (5.6 ± 4.2 µg/L) and Mn (117.4 ± 30.3) µg/L) than CM (2.15 ± 1.84 µg/L and 5.93 ± 1.21 µg/L, respectively); the Pb concentrations in CM (19.3 ± 12.1 µg/L) were not significantly (p > 0.05) higher than in SB (13.4 ± 9.6 µg/L). These values were similar to other studies and close to but under permissible limit values. Nevertheless, due to the toxicity and bioaccumulation of metals, the fact that these foods are routinely ingested by all ages, mainly children, and represent key ingredients in many processed foods, including baby foods, we suggest strict surveying of metal levels in CM and SBs.

7.
bioRxiv ; 2023 Nov 13.
Article in English | MEDLINE | ID: mdl-38014216

ABSTRACT

Prolonged exposure to benzene, a prevalent volatile organic compound (VOC), at concentrations found in smoke, triggers hyperglycemia, and inflammation in mice. Corroborating this with existing epidemiological data, we show a strong correlation between environmental benzene exposure and metabolic impairments in humans. To uncover the underlying mechanisms, we employed a controlled exposure system and continuous glucose monitoring (CGM), revealing rapid blood glucose surges and disturbances in energy homeostasis in mice. These effects were attributed to alterations in the hypothalamic transcriptome, specifically impacting insulin and immune response genes, leading to hypothalamic insulin resistance and neuroinflammation. Moreover, benzene exposure activated microglial transcription characterized by heightened expression of IKKß/NF-κB-related genes. Remarkably, selective removal of IKKß in immune cells or adult microglia in mice alleviated benzene-induced hypothalamic gliosis, and protected against hyperglycemia. In summary, our study uncovers a crucial pathophysiological mechanism, establishing a clear link between airborne toxicant exposure and the onset of metabolic diseases.

8.
ACS Meas Sci Au ; 3(5): 301-314, 2023 Oct 18.
Article in English | MEDLINE | ID: mdl-37868358

ABSTRACT

Despite the ubiquitous absorption of mid-infrared (IR) radiation by virtually all molecules that belong to the major biomolecules groups (proteins, lipids, carbohydrates, nucleic acids), the application of conventional IR microscopy to the life sciences remained somewhat limited, due to the restrictions on spatial resolution imposed by the diffraction limit (in the order of several micrometers). This issue is addressed by AFM-IR, a scanning probe-based technique that allows for chemical analysis at the nanoscale with resolutions down to 10 nm and thus has the potential to contribute to the investigation of nano and microscale biological processes. In this perspective, in addition to a concise description of the working principles and operating modes of AFM-IR, we present and evaluate the latest key applications of AFM-IR to the life sciences, summarizing what the technique has to offer to this field. Furthermore, we discuss the most relevant current limitations and point out potential future developments and areas for further application for fruitful interdisciplinary collaboration.

10.
Glob Chang Biol ; 29(17): 4861-4879, 2023 09.
Article in English | MEDLINE | ID: mdl-37386918

ABSTRACT

For more than three decades, major efforts in sampling and analyzing tree diversity in South America have focused almost exclusively on trees with stems of at least 10 and 2.5 cm diameter, showing highest species diversity in the wetter western and northern Amazon forests. By contrast, little attention has been paid to patterns and drivers of diversity in the largest canopy and emergent trees, which is surprising given these have dominant ecological functions. Here, we use a machine learning approach to quantify the importance of environmental factors and apply it to generate spatial predictions of the species diversity of all trees (dbh ≥ 10 cm) and for very large trees (dbh ≥ 70 cm) using data from 243 forest plots (108,450 trees and 2832 species) distributed across different forest types and biogeographic regions of the Brazilian Amazon. The diversity of large trees and of all trees was significantly associated with three environmental factors, but in contrasting ways across regions and forest types. Environmental variables associated with disturbances, for example, the lightning flash rate and wind speed, as well as the fraction of photosynthetically active radiation, tend to govern the diversity of large trees. Upland rainforests in the Guiana Shield and Roraima regions had a high diversity of large trees. By contrast, variables associated with resources tend to govern tree diversity in general. Places such as the province of Imeri and the northern portion of the province of Madeira stand out for their high diversity of species in general. Climatic and topographic stability and functional adaptation mechanisms promote ideal conditions for species diversity. Finally, we mapped general patterns of tree species diversity in the Brazilian Amazon, which differ substantially depending on size class.


Subject(s)
Acclimatization , Wind , Brazil , Rainforest , Biodiversity
12.
Br Dent J ; 234(11): 783, 2023 Jun.
Article in English | MEDLINE | ID: mdl-37291286
13.
Spectrochim Acta A Mol Biomol Spectrosc ; 298: 122800, 2023 Oct 05.
Article in English | MEDLINE | ID: mdl-37156174

ABSTRACT

L-histidinium hydrogen oxalate (L-HisH)(HC2O4) crystal is formed from amino acid. L-histidine with oxalic acid whose vibrational high pressures behavior have not yet been investigated in the literature. Here we synthesized (L-HisH)(HC2O4) crystal by slow solvent evaporation method in a 1:1 ratio of L-histidine and oxalic acid. In addition, a vibrational study of (L-HisH)(HC2O4) crystal as a function of pressure was performed via Raman spectroscopy in the pressure range of 0.0-7.3 GPa. From analysis of the behavior of the bands within 1.5-2.8 GPa, characterized by the disappearance of lattice modes, the occurrence of a conformational phase transition was noted. A second phase transition, now from structural type, close to 5.1 GPa was observed due to the incidence of considerable changes in lattice and internal modes, mainly in vibrational modes related to imidazole ring motions.

14.
Plant Biol (Stuttg) ; 25(4): 593-602, 2023 Jun.
Article in English | MEDLINE | ID: mdl-37029605

ABSTRACT

Divergence in seed germination patterns among populations of the same species is important for understanding plant responses to environmental gradients and potential plant sensitivity to climate change. In order to test responses to flooding and decreasing water potentials, over 3 years we germinated and grew seeds from three habitats of Euterpe edulis Mart. occurring along an altitudinal gradient. Seed germination and root growth were evaluated under different water availability treatments: control, flood, -0.4 MPa, -0.8 MPa, in the years 2012, 2013 and 2014, and in the final year of the experiment (2014) at -1.0 MPa and -1.5 MPa. Seeds from the montane habitat did not germinate in the flooding treatment. Seed germination of all three habitats decreased in the -1.5 MPa treatment and the montane habitat had lowest germination in this treatment. Time required for half of the seeds to germinate increased up to -0.8 MPa. Seeds from montane habitats germinated more slowly in all treatments. The only difference in seed germination synchrony was an increase in the submontane population under the flooding treatment. However, synchrony decreased at the lowest water potentials. Roots of the montane population were more vigorous in most treatments, except at -0.8 MPa. The unusual ability of these seeds to germinate at low water potentials might be related to early seed germination at the onset of the rainy season, which potentially decreases seed predation pressure. Seeds of the montane population were more sensitive to both types of water stress. A predicted increase in the frequency and intensity of extreme high rainfall or drought events may predispose early stages of this population to adverse factors that might negatively affect population viability with elevational in future climate change scenarios.


Subject(s)
Germination , Seeds , Germination/physiology , Seeds/physiology , Dehydration , Altitude , Ecosystem
16.
Spectrochim Acta A Mol Biomol Spectrosc ; 283: 121716, 2022 Dec 15.
Article in English | MEDLINE | ID: mdl-35961206

ABSTRACT

Crystals of l-asparagine monohydrate doped with Fe(III) were studied by Raman spectroscopy in a diamond anvil cell (DAC) in the spectral range from 100 to 3200 cm-1 and pressures up to 9.2 GPa. The behavior of external modes suggests conformational changes between 3.0 and 4.0 GPa mainly affecting the CH2 group. X-ray diffraction measurements with synchrotron radiation were performed in the angular range from 3 to 12 degrees (2θ) up to 9.3 GPa. The lattice parameters contract up to 9.3 GPa, with the exception of parameter b, which exhibits expansion from 7.2 GPa. The lattice parameters exhibit discontinuities between 3.0 and 4.0 GPa, this effect is compatible with conformational changes. Such modifications occur without a change in symmetry, at least up to 9.3 GPa. Under decompression, down to atmospheric pressure, the original Raman spectrum is recovered, showing that the conformational change and the other changes are all reversible.


Subject(s)
Asparagine , Spectrum Analysis, Raman , Ferric Compounds , Pressure , Synchrotrons , X-Ray Diffraction
17.
Analyst ; 147(16): 3741-3747, 2022 Aug 08.
Article in English | MEDLINE | ID: mdl-35833647

ABSTRACT

The routine analysis of polymer blends at the nanoscale is usually carried out using electron microscopy techniques such as scanning electron microscopy (SEM) and transmission electron microscopy (TEM), which often require several sample preparation steps including staining with heavy metals and/or etching. Atomic force microscopy (AFM) is also commonly used, but provides no direct chemical information about the samples analyzed. AFM-IR, a recent technique which combines the AFM's nanoscale resolution with the chemical information provided by IR spectroscopy, is a valuable complement to the already established techniques. Resonance enhanced AFM-IR (contact mode) is the most commonly used measurement mode, due to its signal enhancement and relative ease of use. However, it has severe drawbacks when used in highly heterogenous samples with changing mechanical properties, such as polymer recyclates. In this work, we use the recently developed tapping mode AFM-IR to chemically image the distribution of rubber in a real-world commercially available polyethylene/polypropylene (PE/PP) recycled blend derived from municipal and household waste. Furthermore, the outstanding IR resolution of AFM-IR allowed for the detection of small PP droplets inside the PE phase. The presence of micro and nanoscale particles of other polymers in the blend was also established, and the polymers identified.

18.
Chemistry ; 28(9): e202200295, 2022 Feb 16.
Article in English | MEDLINE | ID: mdl-35142410

ABSTRACT

Invited for the cover of this issue is the group of Abraham Mendoza at Stockholm University. The image depicts a Grignard reagent "turbo-charged" with a magnesium anilide additive. Read the full text of the article at 10.1002/chem.202104053.

19.
Lett Appl Microbiol ; 74(6): 863-872, 2022 Jun.
Article in English | MEDLINE | ID: mdl-35148433

ABSTRACT

Flow cytometry has emerged as a promising technique for detection of SARS-CoV-2 antibodies. In this study, we developed an innovative strategy for simultaneous detection of immunoglobulin G (IgG), IgM and IgA. The SARS-CoV-2 nucleocapsid protein was covalently bound to functional beads surface applying sulpho-SMCC chemistry. BUV395 anti-IgG, BB515 anti-IgM, biotinylated anti-IgA1/IgA2 and BV421 streptavidin were used as fluorophore conjugated secondary antibodies. Serum and antibodies reaction conditions were optimized for each antibody isotype detection and a multiplexed detection assay was developed. This new cell-free assay efficiently discriminate COVID-19 negative and positive samples. The simultaneous detection of IgG, IgM and IgA showed a sensitivity of 88·5-96·2% and specificity of 100%. This novel strategy opens a new avenue for flow cytometry-based diagnosis.


Subject(s)
Antibodies, Viral , COVID-19 , SARS-CoV-2 , Antibodies, Viral/blood , COVID-19/diagnosis , Flow Cytometry , Humans , Immunoglobulin A/blood , Immunoglobulin G/blood , Immunoglobulin M/blood , Nucleocapsid Proteins , SARS-CoV-2/immunology , Sensitivity and Specificity
20.
Spectrochim Acta A Mol Biomol Spectrosc ; 272: 120944, 2022 May 05.
Article in English | MEDLINE | ID: mdl-35151163

ABSTRACT

Raman spectroscopy and synchrotron radiation X-ray diffraction have been used to study the effect of pressure on 2-(-α-methylbenzylamino)-5-dinitropyridine (MBANP). Several changes are observed with increasing pressure in the Raman spectra of this system, such as splitting of various bands and disappearance of bands. Discontinuous shifts in wavenumber vs pressure plot indicate that a conformational phase transition takes place around 0.5 GPa. The behavior of the Raman spectra indicates that MBANP molecules present conformational phase transition at high-pressure. X-ray diffraction, performed with synchrotron radiation, confirms the conformational changes observed by Raman experiments around 0.5 GPa. The pressure provokes a rotational movement of the benzene ring which can be associated with the conformational phase transition.


Subject(s)
Spectrum Analysis, Raman , Synchrotrons , Molecular Conformation , Phase Transition , Spectrum Analysis, Raman/methods , X-Ray Diffraction
SELECTION OF CITATIONS
SEARCH DETAIL
...