Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 291
Filtrar
1.
Biology (Basel) ; 13(7)2024 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-39056666

RESUMO

This study evaluated the bone incorporation process of a screw-shaped internal fixation device made of poly (L-lactide-co-D, L-lactide) (PLDLLA). Thirty-two male Wistar rats received 32 fixation devices (2 mm × 6 mm) randomly assigned to either the right or left tibia and one implant in each animal. After 7, 14, 28, and 42 days, the rats were euthanized and the specimens were subjected to microtomographic computed tomography (microCT) and histomorphometric analyses to evaluate bone interface contact (BIC%) and new bone formation (NBF%) in cortical and cancellous bone areas. The animals euthanized on days 28 and 42 were treated with calcein and alizarin red, and confocal LASER microscopy was performed to determine the mineral apposition rate (MAR). Micro-CT revealed a higher percentage of bone volume (p < 0.006), trabecular separation (p < 0.001), and BIC in the cortical (p < 0.001) and cancellous (p = 0.003) areas at 28 and 42 days than at 7 and 14 days. The cortical NBF at 42 days was greater than that at 7 and 14 days (p = 0.022). No statistically significant differences were observed in cancellous NBF or MAR at 28 and 42 days. Based on these results, it can be seen that the PLDLLA internal fixation device is biocompatible and allows new bone formation around the screw thread.

3.
Toxicon ; 241: 107680, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38452976

RESUMO

In this work, we compared the biochemical and toxicological profiles of venoms from an adult female specimen of Lachesis muta rhombeata (South American bushmaster) and her seven offspring born in captivity, based on SDS-PAGE, RP-HPLC, enzymatic, coagulant, and hemorrhagic assays. Although adult and juvenile venoms showed comparable SDS-PAGE profiles, juveniles lacked some chromatographic peaks compared with adult venom. Adult venom had higher proteolytic (caseinolytic) activity than juvenile venoms (p < 0.05), but there were no significant inter-venom variations in the esterase, PLA2, phosphodiesterase and L-amino acid oxidase (LAAO) activities, although the latter activity was highly variable among the venoms. Juveniles displayed higher coagulant activity on human plasma, with a minimum coagulant dose ∼42% lower than the adult venom (p < 0.05), but there were no age-related differences in thrombin-like activity. Adult venom was more fibrinogenolytic (based on the rate of fibrinogen chain degradation) and hemorrhagic than juvenile venoms (p < 0.05). The effective dose of Bothrops/Lachesis antivenom (produced by the Instituto Butantan) needed to neutralize the coagulant activity was ∼57% greater for juvenile venoms (p < 0.05), whereas antivenom did not attenuate the thrombin-like activity of juvenile and adult venoms. Antivenom significantly reduced the hemorrhagic activity of adult venom (400 µg/kg, i. d.), but not that of juvenile venoms. Overall, these data indicate a compositional and functional ontogenetic shift in L. m. rhombeata venom.


Assuntos
Antivenenos , Venenos de Crotalídeos , Crotalinae , Serpentes Peçonhentas , Feminino , Humanos , Adulto , Antivenenos/farmacologia , Venenos de Crotalídeos/toxicidade , Venenos de Crotalídeos/química , Trombina , Hemorragia
4.
J Prosthet Dent ; 2023 Dec 05.
Artigo em Inglês | MEDLINE | ID: mdl-38057198

RESUMO

A 2-piece premanufactured glass-fiber post-and-core for a child with a severely compromised endodontically treated tooth to restore dental form, function, and esthetics, is described. A shorter chair time than for the conventional options was needed, and the post provided an adequate biomechanical response with a reduced intracanal cement thickness.

5.
Toxicon ; 234: 107285, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37683698

RESUMO

Oral and other cephalic glands have been surveyed by several studies with distinct purposes. Despite the wide diversity and medical relevance of the New World coral snakes, studies focusing on understanding the biological roles of the glands within this group are still scarce. Specifically, the venom glands of some coral snakes were previously investigated but all other cephalic glands remain uncharacterized. In this sense, performing morphological and molecular analysis of these glands may help better understand their biological role. Here, we studied the morphology of the venom, infralabial, rictal, and harderian glands of thirteen species of Micrurus and Micruroides euryxanthus. We also performed a molecular characterization of these glands from selected species of Micrurus using transcriptomic and proteomic approaches. We described substantial morphological variation in the cephalic glands of New World coral snakes and structural evidence for protein-secreting cells in the inferior rictal glands. Our molecular analysis revealed that the venom glands, as expected, are majorly devoted to toxin production, however, the infralabial and inferior rictal glands also expressed some toxin genes at low to medium levels, despite the marked morphological differences. On the other hand, the harderian glands were dominated by the expression of lipocalins, but do not produce toxins. Our integrative analysis, including the prediction of biological processes and pathways, helped decipher some important traits of cephalic glands and better understand their biology.

6.
Sci Rep ; 13(1): 11674, 2023 07 19.
Artigo em Inglês | MEDLINE | ID: mdl-37468518

RESUMO

Coralsnakes of the genus Micrurus are a diverse group of venomous snakes ranging from the southern United States to southern South America. Much uncertainty remains over the genus diversity, and understanding Micrurus systematics is of medical importance. In particular, the widespread Micrurus nigrocinctus spans from Mexico throughout Central America and into Colombia, with a number of described subspecies. This study provides new insights into the phylogenetic relationships within M. nigrocinctus by examining sequence data from a broad sampling of specimens from Mexico, Guatemala, Honduras, Nicaragua, Costa Rica, and Panama. The recovered phylogenetic relationships suggest that M. nigrocinctus is a species complex originating in the Pliocene and composed of at least three distinct species-level lineages. In addition, recovery of highly divergent clades supports the elevation of some currently recognized subspecies to the full species rank while others may require synonymization.


Assuntos
Peçonhas , Estados Unidos , Filogenia , América Central , Panamá , México
7.
J Clin Med ; 12(10)2023 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-37240681

RESUMO

The Prechtl General Movements Assessment (GMA) has become a clinician and researcher toolbox for evaluating neurodevelopment in early infancy. Given that it involves the observation of infant movements from video recordings, utilising smartphone applications to obtain these recordings seems like the natural progression for the field. In this review, we look back on the development of apps for acquiring general movement videos, describe the application and research studies of available apps, and discuss future directions of mobile solutions and their usability in research and clinical practice. We emphasise the importance of understanding the background that has led to these developments while introducing new technologies, including the barriers and facilitators along the pathway. The GMApp and Baby Moves apps were the first ones developed to increase accessibility of the GMA, with two further apps, NeuroMotion and InMotion, designed since. The Baby Moves app has been applied most frequently. For the mobile future of GMA, we advocate collaboration to boost the field's progression and to reduce research waste. We propose future collaborative solutions, including standardisation of cross-site data collection, adaptation to local context and privacy laws, employment of user feedback, and sustainable IT structures enabling continuous software updating.

9.
Cardiovasc Toxicol ; 23(3-4): 132-146, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36813862

RESUMO

In this work, we examined the action of two South American coralsnake (Micrurus corallinus and Micrurus dumerilii carinicauda) venoms on rat heart function in the absence and presence of treatment with Brazilian coralsnake antivenom (CAV) and varespladib (VPL), a potent phospholipase A2 inhibitor. Anesthetized male Wistar rats were injected with saline (control) or a single dose of venom (1.5 mg/kg, i.m.) and monitored for alterations in echocardiographic parameters, serum CK-MB levels and cardiac histomorphology, the latter using a combination of fractal dimension and histopathological methods. Neither of the venoms caused cardiac functional alterations 2 h after venom injection; however, M. corallinus venom caused tachycardia 2 h after venom injection, with CAV (given i.p. at an antivenom:venom ratio of 1:1.5, v/w), VPL (0.5 mg/kg, i.p.) and CAV + VPL preventing this increase. Both venoms increased the cardiac lesional score and serum CK-MB levels compared to saline-treated rats, but only the combination of CAV + VPL prevented these alterations, although VPL alone was able to attenuate the increase in CK-MB caused by M. corallinus venom. Micrurus corallinus venom increased the heart fractal dimension measurement, but none of the treatments prevented this alteration. In conclusion, M. corallinus and M. d. carinicauda venoms caused no major cardiac functional alterations at the dose tested, although M. corallinus venom caused transient tachycardia. Both venoms caused some cardiac morphological damage, as indicated by histomorphological analyses and the increase in circulating CK-MB levels. These alterations were consistently attenuated by a combination of CAV and VPL.


Assuntos
Cobras Corais , Elapidae , Masculino , Ratos , Animais , Antivenenos/farmacologia , Venenos Elapídicos/toxicidade , Brasil , Ratos Wistar , Taquicardia
11.
N Engl J Med ; 386(22): 2112-2119, 2022 06 02.
Artigo em Inglês | MEDLINE | ID: mdl-35648703

RESUMO

A patient with progressive metastatic pancreatic cancer was treated with a single infusion of 16.2×109 autologous T cells that had been genetically engineered to clonally express two allogeneic HLA-C*08:02-restricted T-cell receptors (TCRs) targeting mutant KRAS G12D expressed by the tumors. The patient had regression of visceral metastases (overall partial response of 72% according to the Response Evaluation Criteria in Solid Tumors, version 1.1); the response was ongoing at 6 months. The engineered T cells constituted more than 2% of all the circulating peripheral-blood T cells 6 months after the cell transfer. In this patient, TCR gene therapy targeting the KRAS G12D driver mutation mediated the objective regression of metastatic pancreatic cancer. (Funded by the Providence Portland Medical Foundation.).


Assuntos
Terapia Genética , Neoplasias Pancreáticas , Proteínas Proto-Oncogênicas p21(ras) , Receptores de Antígenos de Linfócitos T , Genes Codificadores dos Receptores de Linfócitos T/genética , Terapia Genética/métodos , Humanos , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/patologia , Neoplasias Pancreáticas/terapia , Proteínas Proto-Oncogênicas p21(ras)/genética , Receptores de Antígenos de Linfócitos T/genética , Receptores de Antígenos de Linfócitos T/uso terapêutico , Neoplasias Pancreáticas
12.
Toxicon ; 213: 99-104, 2022 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-35489427

RESUMO

In this work, we reported the efficacy of a combination of Brazilian therapeutic coralsnake antivenom (CAV) and varespladib (phospholipase A2 inhibitor - VPL) in partially neutralizing selected toxic effects of Micrurus dumerilii carinicauda coralsnake venom in rats. Venom caused local myonecrosis and systemic neurotoxicity, nephrotoxicity, and hepatotoxicity within 2 h of injection. CAV and VPL administered separately failed to prevent most of these alterations. However, a combination of CAV plus VPL offered variable protection against venom-induced coagulation disturbances, leukocytosis, and renal-hepatic morphological alterations.


Assuntos
Cobras Corais , Acetatos , Animais , Antivenenos/farmacologia , Brasil , Venenos Elapídicos/toxicidade , Indóis , Cetoácidos , Ratos
13.
Cancer Cell ; 40(4): 410-423.e7, 2022 04 11.
Artigo em Inglês | MEDLINE | ID: mdl-35413272

RESUMO

Tumor-infiltrating neoantigen-reactive T cells can mediate regression of metastatic gastrointestinal cancers yet remain poorly characterized. We performed immunological screening against personalized neoantigens in combination with single-cell RNA sequencing on tumor-infiltrating lymphocytes from bile duct and pancreatic cancer patients to characterize the transcriptomic landscape of neoantigen-reactive T cells. We found that most neoantigen-reactive CD8+ T cells displayed an exhausted state with significant CXCL13 and GZMA co-expression compared with non-neoantigen-reactive bystander cells. Most neoantigen-reactive CD4+ T cells from a patient with bile duct cancer also exhibited an exhausted phenotype but with overexpression of HOPX or ADGRG1 while lacking IL7R expression. Thus, neoantigen-reactive T cells infiltrating gastrointestinal cancers harbor distinct transcriptomic signatures, which may provide new opportunities for harnessing these cells for therapy.


Assuntos
Linfócitos T CD8-Positivos , Neoplasias Gastrointestinais , Antígenos de Neoplasias , Neoplasias Gastrointestinais/genética , Humanos , Linfócitos do Interstício Tumoral , Transcriptoma
14.
J Prosthet Dent ; 127(1): 1-5, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-35027149

RESUMO

This JPD Digital video presentation presents the clinical treatment from start to finish in which a dual-shaded bi-coloured monolithic disk was used for the fabrication of an immediate digital complete denture followed by the delivery of a definitive digital complete denture. The treatment plan included extraction of the remaining maxillary and mandibular teeth followed by an esthetic evaluation with digital smile design. The digital definitive complete dentures were milled from a monolithic dual-shaded disk.


Assuntos
Desenho Assistido por Computador , Prótese Parcial Removível , Prótese Total , Prótese Total Imediata , Prótese Parcial , Estética Dentária
15.
Toxicol Lett ; 356: 54-63, 2022 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-34774704

RESUMO

In this study, we investigated the action of varespladib (VPL) alone or in combination with a coral snake antivenom (CAV) on the local and systemic effects induced by Micrurus corallinus venom in rats. Adult male Wistar rats were exposed to venom (1.5 mg/kg - i.m.) and immediately treated with CAV (antivenom:venom ratio 1:1.5 'v/w' - i.p.), VPL (0.5 mg/kg - i.p.), or both of these treatments. The animals were monitored for 120 min and then anesthetized to collect blood samples used for haematological and serum biochemical analysis; after euthanasia, skeletal muscle, renal and hepatic tissue samples were collected for histopathological analysis. M. corallinus venom caused local oedema without subcutaneous haemorrhage or apparent necrosis formation, although there was accentuated muscle morphological damage; none of the treatments prevented oedema formation but the combination of CAV and VPL reduced venom-induced myonecrosis. Venom caused neuromuscular paralysis and respiratory impairment in approximately 60 min following envenomation; CAV alone did not prevent the neurotoxic action, whereas VPL alone prevented neurotoxic symptoms developing as did the combination of CAV and VPL. Venom induced significant increase of serum CK and AST release, mostly due to local and systemic myotoxicity, which was partially prevented by the combination of CAV and VPL. The release of hepatotoxic serum biomarkers (LDH and ALP) induced by M. corallinus venom was not prevented by CAV and VPL when individually administered; their combination effectively prevented ALP release. The venom-induced nephrotoxicity (increase in serum creatinine concentration) was prevented by all the treatments. VPL alone or in combination with CAV significantly prevented the venom-induced lymphocytosis. In conclusion, VPL shows to be effective at preventing the neurotoxic, nephrotoxic, and inflammatory activities of M. corallinus venom. In addition, VPL acts synergistically with antivenom to prevent a number of systemic effects caused by M. corallinus venom.


Assuntos
Acetatos/farmacologia , Cobras Corais/fisiologia , Venenos Elapídicos/toxicidade , Indóis/farmacologia , Cetoácidos/farmacologia , Inibidores de Fosfolipase A2/farmacologia , Animais , Biomarcadores/sangue , Transtornos da Coagulação Sanguínea/induzido quimicamente , Transtornos da Coagulação Sanguínea/tratamento farmacológico , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , L-Lactato Desidrogenase/sangue , Fármacos Neuroprotetores/farmacologia , Fosfolipases A2/genética , Fosfolipases A2/metabolismo , Ratos , Ratos Wistar
16.
J Prosthet Dent ; 127(4): 550-555, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33549339

RESUMO

This report describes a digital workflow for the fabrication of a complete maxillary denture opposing an implant-retained overdenture. This procedure provides a predictable and accurate 3-visit technique to digitally scan and articulate edentulous ridges, avoiding the discomfort associated with analog impression making. Wax rims were applied to intraorally relined plastic edentulous stock trays. The occlusal relationship was registered at the appropriate vertical dimension of occlusion by using these tray and rim assemblies. The digital laboratory scanning of the relined tray and rim assemblies resulted in accurate virtual articulation of the digital edentulous intraoral scans. The removable restorations were digitally designed, milled, and delivered, and the clinical and laboratory steps are described.


Assuntos
Prótese Total , Boca Edêntula , Desenho Assistido por Computador , Revestimento de Dentadura , Humanos , Fluxo de Trabalho
17.
Sci Total Environ ; 798: 149241, 2021 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-34333429

RESUMO

The postglacial Patagonian fjord system along the west coast of southern South America is one of the largest stretches of the southern hemisphere (SH) fjord belt, influenced by the SH westerly wind belt and continental freshwater input. This study reports a 3-year monthly time series (2017-2020) of physical and biogeochemical parameters obtained from the Reloncaví Marine Observatory (OMARE, Spanish acronym) at the northernmost embayment and fjord system of Patagonia. The main objective of this work was to understand the land-atmosphere-ocean interactions and to identify the mechanisms that modulate the density of phytoplankton. A key finding of this study was the seasonally varying asynchronous input of oceanic and estuarine water. Surface lower salinity and warmer estuarine water arrived in late winter to summer, contributing to water column stability, followed by subsurface higher salinity and less warmer oceanic water during fall-winter. In late winter 2019, an interannual change above the picnocline due to the record-high polarity of the Indian Ocean Dipole inhibited water column stability. The biogeochemical parameters (NO3-, NO2-, PO43-, Si(OH)4, pH, and dissolved oxygen) responded to the surface annual salinity variations, and oceanic water mass contributed greatly to the subsurface inorganic nutrient input. The water column N/P ratio indicated that no eutrophication occurred, even under intense aquaculture activity, likely because of the high ventilation dynamics of the Reloncaví Sound. Finally, a shift in phytoplankton composition, characterized by surface chlorophyll-a maxima in late winter and deepening of spring-summer blooms related to the physicochemical conditions of the water column, was observed. Our results support the ecosystem services provided by local oceanography processes in the north Patagonian fjords. Here, the anthropogenic impact caused by economic activities could be, in part, chemically reduced by the annual ventilation cycle mediated by the exchange of oceanic water masses into Patagonian fjords.


Assuntos
Ecossistema , Estuários , Monitoramento Ambiental , Oceano Índico , Oceanografia , Fitoplâncton , Água do Mar
18.
Toxicon ; 198: 36-47, 2021 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-33915137

RESUMO

In this study, we examined the potential use of N-acetyl-L-cysteine (NAC) in association with a polyvalent antivenom and as stand-alone therapy to reduce the acute local and systemic effects induced by Lachesis muta muta venom in rats. Male Wistar rats (300-350 g) were exposed to L. m. muta venom (1.5 mg/kg - i.m.) and subsequently treated with anti-Bothrops/Lachesis serum (antivenom:venom ratio 1:3 'v/w' - i.p.) and NAC (150 mg/kg - i.p.) separately or in association; the animals were monitored for 120 min to assess changes in temperature, locomotor activity, local oedema formation and the prevalence of haemorrhaging. After this time, animals were anesthetized in order to collect blood samples through intracardiac puncture and then euthanized for collecting tissue samples; the hematological-biochemical and histopathological analyses were performed through conventional methods. L. m. muta venom produced pronounced local oedema, subcutaneous haemorrhage and myonecrosis, with both antivenom and NAC successfully reducing the extent of the myonecrotic lesion when individually administered; their association also prevented the occurrence of subcutaneous haemorrhage. Venom-induced creatine kinase (CK) release was significantly prevented by NAC alone or in combination with antivenom; NAC alone failed to reduce the release of hepatotoxic (alanine aminotransferase) and nephrotoxic (creatinine) serum biomarkers induced by L. m. muta venom. Venom induced significant increase of leucocytes which was also associated with an increase of neutrophils, eosinophils and monocytes; antivenom and NAC partially reduced these alterations, with NAC alone significantly preventing the increase of eosinophils whereas neither NAC or antivenom prevented the increase in monocytes. Venom did not induce changes in the erythrogram parameters. In the absence of a suitable antivenom, NAC has the potential to reduce a number of local and systemic effects caused by L. m. muta venom.


Assuntos
Venenos de Crotalídeos , Viperidae , Acetilcisteína/uso terapêutico , Animais , Antivenenos/uso terapêutico , Venenos de Crotalídeos/toxicidade , Masculino , Ratos , Ratos Wistar , Venenos de Víboras/toxicidade
19.
J Prosthodont ; 30(7): 555-560, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33834588

RESUMO

The purpose of this clinical case report is to describe a fully digital workflow for the duplication of an existing implant retained overdenture, highlighting the benefits of digitally fabricated dentures. The patient presented with an existing mandibular implant retained overdenture on Locator attachments that needed to be replaced. The existing overdenture was duplicated/scanned with the use of an intraoral scanner and was 3D printed using acrylic resin. This resin duplicate was sectioned in the midline and served as a unilateral record base to digitally record maxillo-mandibular relationship. The occlusal relationship was scanned unilaterally with the record base (sectioned duplicate) in place, and the procedure was repeated for the opposite side. All scans (edentulous, bite registrations and preliminary scan) were superimposed and the software managed to position and stich everything together. A try-in copy denture (ProArtCAD Try in, Ivoclar Vivadent AG, Schaan, Liechtenstein) was milled in order to imitate the conventional wax teeth try-in. A definitive milled overdenture was fabricated and delivered. A reinforcing polyetheretherketone mesh was fabricated, utilizing computer assisted design/computer assisted manufacturing technology and was incorporated into the pre-designed customized space into the polymethylmethacrylate base, using indirect light-polymerized nano-filled composite resin (crea.lign; bredent GmbH & Co. KG). Occlusion was verified and the patient was instructed oral hygiene, home maintenance and was informed for the required recall visits.


Assuntos
Implantes Dentários , Revestimento de Dentadura , Prótese Dentária Fixada por Implante , Humanos , Mandíbula , Fluxo de Trabalho
20.
Indian Heart J ; 73(2): 228-230, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33865525

RESUMO

The prognostic value of atrial thrombi (AT) among elective patients with atrial fibrillation (AF) referred for a rhythm control strategy is unclear. In this study, clinical variables were correlated with the presence of AT and long term survival among 205 patients submitted to transesophageal echocardiography before elective AF cardioversion or ablation. Atrial thrombi were present in 7.8% of cases and were significantly associated with reduced survival. Obesity was the only independent clinical predictor of AT [OR 4.27 (1.15-15.79), p = 0.03]. In patients with AF, AT appear to be associated with adverse outcomes, possibly indicating more advanced atrial cardiomyopathy.


Assuntos
Fibrilação Atrial , Tromboembolia , Trombose , Fibrilação Atrial/complicações , Fibrilação Atrial/diagnóstico , Fibrilação Atrial/epidemiologia , Ecocardiografia Transesofagiana , Cardioversão Elétrica , Humanos , Prognóstico , Fatores de Risco , Trombose/diagnóstico , Trombose/epidemiologia , Trombose/etiologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA