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1.
Macromolecules ; 56(18): 7320-7331, 2023 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-37781212

RESUMO

The solid-state properties of supramolecular polymers that feature metal-ligand (ML) complexes are, in addition to the general nature of the monomer, significantly affected by the choice of ligand and metal salt. Indeed, the variation of these components can be used to alter the structural, thermal, mechanical, and viscoelastic properties over a wide ranges. Moreover, the dynamic nature of certain ML complexes can render the resulting metallosupramolecular polymers (MSPs) stimuli-responsive, enabling functions such as healing, reversible adhesion, and mechanotransduction. We here report MSPs based on the bidentate ligand 6-(1'-methylbenzimidazolyl) pyridine (MBP), which is easily accessible and forms threefold coordination complexes with various transition metal ions. Thus, a poly(ethylene-co-butylene) telechelic was end-functionalized with two MBP ligands and the resulting macromonomer was assembled with the triflate salts of either Zn2+, Fe2+, or Ni2+. All three MSPs microphase separate and adopt, depending on the metal ion and thermal history, lamellar or hexagonal morphologies with crystalline domains formed by the ML complexes. The melting transitions are well below 200 °C, and this permits facile (re)processing. Furthermore, defects can be readily and fully healed upon exposure to UV-light. While the three MSPs display similar moduli in the rubbery regime, their extensibility and tensile strength depend on the nature of the ML complex, which similarly affects the long-range order and dynamic behavior.

2.
Environ Health ; 20(1): 119, 2021 11 17.
Artigo em Inglês | MEDLINE | ID: mdl-34784917

RESUMO

BACKGROUND: Epistemological biases in environmental epidemiology prevent the full understanding of how racism's societal impacts directly influence health outcomes. With the ability to focus on "place" and the totality of environmental exposures, environmental epidemiologists have an important opportunity to advance the field by proactively investigating the structural racist forces that drive disparities in health. OBJECTIVE: This commentary illustrates how environmental epidemiology has ignored racism for too long. Some examples from environmental health and male infertility are used to illustrate how failing to address racism neglects the health of entire populations. DISCUSSION: While research on environmental justice has attended to the structural sources of environmental racism, this work has not been fully integrated into the mainstream of environmental epidemiology. Epidemiology's dominant paradigm that reduces race to a mere data point avoids the social dimensions of health and thus fails to improve population health for all. Failing to include populations who are Black, Indigenous, and people of color (BIPOC) in health research means researchers actually know very little about the effect of environmental contaminants on a range of population health outcomes. This commentary offers different practical solutions, such as naming racism in research, including BIPOC in leadership positions, mandating requirements for discussing "race", conducting far more holistic analyses, increasing community participation in research, and improving racism training, to address the myriad of ways in which structural racism permeates environmental epidemiology questions, methods, results and impacts.


Assuntos
Racismo , Racismo Sistêmico , Saúde Ambiental , Humanos , Masculino
3.
Anal Chem ; 93(45): 15175-15182, 2021 11 16.
Artigo em Inglês | MEDLINE | ID: mdl-34723506

RESUMO

The importance of protein glycosylation in the biomedical field requires methods that not only quantitate structures by their monosaccharide composition, but also resolve and identify the many isomers expressed by mammalian cells. The art of unambiguous identification of isomeric structures in complex mixtures, however, did not yet catch up with the fast pace of advance of high-throughput glycomics. Here, we present a strategy for deducing structures with the help of a deci-minute accurate retention time library for porous graphitic carbon chromatography with mass spectrometric detection. We implemented the concept for the fundamental N-glycan type consisting of five hexoses, four N-acetylhexosamines and one fucose residue. Nearly all of the 40 biosynthetized isomers occupied unique elution positions. This result demonstrates the unique isomer selectivity of porous graphitic carbon. With the help of a rather tightly spaced grid of isotope-labeled internal N-glycan, standard retention times were transposed to a standard chromatogram. Application of this approach to animal and human brain N-glycans immediately identified the majority of structures as being of the bisected type. Most notably, it exposed hybrid-type glycans with galactosylated and even Lewis X containing bisected N-acetylglucosamine, which have not yet been discovered in a natural source. Thus, the time grid approach implemented herein facilitated discovery of the still missing pieces of the N-glycome in our most noble organ and suggests itself─in conjunction with collision induced dissociation─as a starting point for the overdue development of isomer-specific deep structural glycomics.


Assuntos
Glicômica , Polissacarídeos , Animais , Encéfalo , Fucose , Glicosilação , Humanos
4.
BMC Cancer ; 21(1): 1108, 2021 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-34654395

RESUMO

BACKGROUND: Diffuse gliomas are the most common malignant tumors of the central nervous system with poor treatment efficacy. Infiltration of immune cells into tumors during immunosurveillance is observed in multiple tumor entities and often associated with a favorable outcome. The aim of this study was to evaluate the infiltration of immune cells in gliomas and their association with cerebrospinal fluid (CSF) cytokine concentrations. METHODS: We applied immunohistochemistry in tumor tissue sections of 18 high-grade glioma (HGG) patients (4 anaplastic astrocytoma, IDH-wildtype WHO-III; 14 glioblastomas (GBM), IDH-wildtype WHO-IV) in order to assess and quantify leucocytes (CD45) and macrophages (CD68, CD163) within the tumor core, infiltration zone and perivascular spaces. In addition, we quantified the concentrations of 30 cytokines in the same patients' CSF and in 14 non-inflammatory controls. RESULTS: We observed a significantly higher percentage of CD68+ macrophages (21-27%) in all examined tumor areas when compared to CD45+ leucocytes (ca. 3-7%); CD163+ cell infiltration was between 5 and 15%. Compared to the tumor core, significantly more macrophages and leucocytes were detectable within the perivascular area. The brain parenchyma showing a lower tumor cell density seems to be less infiltrated by macrophages. Interleukin (IL)-7 was significantly downregulated in CSF of GBM patients compared to controls. Additionally, CD68+ macrophage infiltrates showed significant correlations with the expression of eotaxin, interferon-γ, IL-1ß, IL-2, IL-10, IL-13, IL-16 and vascular endothelial growth factor. CONCLUSIONS: Our findings suggest that the infiltration of lymphocytes is generally low in HGG, and does not correlate with cytokine concentrations in the CSF. In contrast, macrophage infiltrates in HGG are associated with CSF cytokine changes that possibly shape the tumor microenvironment. Although results point towards an escape from immunosurveillance or even exploitation of immune cells by HGG, further studies are necessary to decipher the exact role of the immune system in these tumors.


Assuntos
Astrocitoma/líquido cefalorraquidiano , Neoplasias Encefálicas/líquido cefalorraquidiano , Citocinas/líquido cefalorraquidiano , Glioblastoma/líquido cefalorraquidiano , Leucócitos , Macrófagos , Adulto , Idoso , Idoso de 80 Anos ou mais , Antígenos CD , Antígenos de Diferenciação Mielomonocítica , Astrocitoma/patologia , Neoplasias Encefálicas/patologia , Contagem de Células , Quimiocina CCL11/líquido cefalorraquidiano , Feminino , Glioblastoma/patologia , Humanos , Imuno-Histoquímica , Interferon gama/líquido cefalorraquidiano , Interleucinas/líquido cefalorraquidiano , Leucócitos/citologia , Linfócitos do Interstício Tumoral/citologia , Macrófagos/citologia , Masculino , Pessoa de Meia-Idade , Receptores de Superfície Celular , Microambiente Tumoral , Fator A de Crescimento do Endotélio Vascular/líquido cefalorraquidiano
5.
Europace ; 23(11): 1751-1756, 2021 11 08.
Artigo em Inglês | MEDLINE | ID: mdl-34534277

RESUMO

AIMS: Data regarding the efficacy of catheter ablation in heart failure patients with severely dilated left atrium and reduced left ventricular ejection fraction (LVEF) are scanty. We sought to assess the efficacy of catheter ablation in patients with reduced LVEF and severe left atrial (LA) enlargement, and to compare it to those patients with preserved left ventricular function and equally dilated left atrium. METHODS AND RESULTS: Three patient groups with paroxysmal or persistent atrial fibrillation (AF) undergoing a first pulmonary vein isolation (PVI) were considered: Group 1 included patients with normal or mildly abnormal LA volume (≤41 mL/m2) and normal LVEF; Group 2 included patients with severe LA enlargement (>48 mL/m2) and normal LVEF; and Group 3 included patients with severe LA enlargement and reduced LVEF. Time to event analysis was used to investigate AF recurrences. The study cohort includes 439 patients; Group 3 had a higher prevalence of cardiovascular risk factors. LA enlargement was associated with a two-fold in risk of AF recurrence, on the contrary only a smaller non-significant increase of 30% was shown with the further addition of LVEF reduction. CONCLUSIONS: The long-term outcome of patients with severe LA dilatation and reduced LVEF is comparable to those with severe LA enlargement but preserved LVEF. Long-term efficacy of PVI is certainly affected by the enlargement of the left atrium, but less so by the addition of a reduced LVEF. CA remains the best strategy for rhythm control both in paroxysmal and persistent AF in this subgroup of patients.


Assuntos
Fibrilação Atrial , Ablação por Cateter , Veias Pulmonares , Fibrilação Atrial/complicações , Fibrilação Atrial/diagnóstico , Fibrilação Atrial/cirurgia , Ablação por Cateter/efeitos adversos , Ablação por Cateter/métodos , Átrios do Coração/diagnóstico por imagem , Átrios do Coração/cirurgia , Humanos , Veias Pulmonares/cirurgia , Recidiva , Volume Sistólico , Resultado do Tratamento , Função Ventricular Esquerda
6.
Sci Adv ; 7(18)2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33910908

RESUMO

Self-healing or healable polymers can recuperate their function after physical damage. This process involves diffusion of macromolecules across severed interfaces until the structure of the interphase matches that of the pristine material. However, monitoring this nanoscale process and relating it to the mechanical recovery remain elusive. We report that studying diffusion across healed interfaces and a correlation of contact time, diffusion depth, and mechanical properties is possible when two metallosupramolecular polymers assembled with different lanthanoid salts are mended. The materials used display similar properties, while the metal ions can be tracked with high spatial resolution by energy-dispersive x-ray spectrum imaging. We find that healing actual defects requires an interphase thickness in excess of 100 nm, 10 times more than previously established for self-adhesion of smooth films of glassy polymers.

7.
J Am Heart Assoc ; 10(2): e018572, 2021 01 19.
Artigo em Inglês | MEDLINE | ID: mdl-33410337

RESUMO

Background Short ECG P-wave duration has recently been demonstrated to be associated with higher risk of atrial fibrillation (AF). The aim of this study was to assess the rate of AF recurrence after pulmonary vein isolation in patients with a short P wave, and to mechanistically elucidate the observation by computer modeling. Methods and Results A total of 282 consecutive patients undergoing a first single-pulmonary vein isolation procedure for paroxysmal or persistent AF were included. Computational models studied the effect of adenosine and sodium conductance on action potential duration and P-wave duration (PWD). About 16% of the patients had a PWD of 110 ms or shorter (median PWD 126 ms, interquartile range, 115 ms-138 ms; range, 71 ms-180 ms). At Cox regression, PWD was significantly associated with AF recurrence (P=0.012). Patients with a PWD <110 ms (hazard ratio [HR], 2.20; 95% CI, 1.24-3.88; P=0.007) and patients with a PWD ≥140 (HR, 1.87, 95% CI, 1.06-3.30; P=0.031) had a nearly 2-fold increase in risk with respect to the other group. In the computational model, adenosine yielded a significant reduction of action potential duration 90 (52%) and PWD (7%). An increased sodium conductance (up to 200%) was robustly accompanied by an increase in conduction velocity (26%), a reduction in action potential duration 90 (28%), and PWD (22%). Conclusions One out of 5 patients referred for pulmonary vein isolation has a short PWD which was associated with a higher rate of AF after the index procedure. Computer simulations suggest that shortening of atrial action potential duration leading to a faster atrial conduction may be the cause of this clinical observation.


Assuntos
Potenciais de Ação , Fibrilação Atrial , Ablação por Cateter , Eletrocardiografia/métodos , Sistema de Condução Cardíaco , Complicações Pós-Operatórias , Potenciais de Ação/efeitos dos fármacos , Potenciais de Ação/fisiologia , Adenosina/farmacologia , Antiarrítmicos/farmacologia , Fibrilação Atrial/diagnóstico , Fibrilação Atrial/fisiopatologia , Ablação por Cateter/efeitos adversos , Ablação por Cateter/métodos , Simulação por Computador , Feminino , Sistema de Condução Cardíaco/efeitos dos fármacos , Sistema de Condução Cardíaco/fisiopatologia , Humanos , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias/diagnóstico , Complicações Pós-Operatórias/etiologia , Complicações Pós-Operatórias/fisiopatologia , Veias Pulmonares/cirurgia , Recidiva , Canais de Sódio/fisiologia
8.
Andrology ; 9(1): 30-32, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-32471002

RESUMO

Research is needed to understand the presence of the SARS-CoV-2 virus in semen, sexual transmissibility, and impact on sperm quality. Several studies have examined men recovering from COVID-19, but large-scale community-based testing is needed to ascertain the effects on the male reproductive tract, and the potential for prolonged transmission.


Assuntos
COVID-19/virologia , SARS-CoV-2/patogenicidade , Sêmen/virologia , Doenças Virais Sexualmente Transmissíveis/virologia , Espermatozoides/virologia , Animais , COVID-19/diagnóstico , COVID-19/transmissão , Teste para COVID-19 , Interações Hospedeiro-Patógeno , Humanos , Masculino , Análise do Sêmen , Doenças Virais Sexualmente Transmissíveis/diagnóstico , Doenças Virais Sexualmente Transmissíveis/transmissão , Espermatozoides/patologia , Virulência
10.
J Immunol ; 203(1): 208-215, 2019 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-31101665

RESUMO

Mucosal plasma cells (PC) and Ig production are essential to fend pathogens and to maintain mucosal homeostasis. In human Helicobacter pylori infection, mucosal PC express inducible NO synthase (iNOS), which positively correlates with clearance of experimental human infection. To characterize Ig genes and specificities of antral mucosal iNOS+ and iNOS- PC in H. pylori infection, we sequenced rearranged Ig genes from single cell-sorted PC from biopsy specimens of chronically infected patients and analyzed them with respect to their molecular features. The binding specificity of individual PC's Ig was determined following recombinant expression. We identified high rates of somatic hypermutations, especially targeting RGYW/WRCY hotspot motifs in the individual Ig genes, indicating T cell-dependent maturation. For seven of 14 recombinantly expressed Ig, Ag specificity could be determined. Two clones reacted to H. pylori proteins, and five were found to be polyreactive against LPSs, dsDNA, and ssDNA. All specific Ig originated from iNOS+ PC. H. pylori-specific Ig are encoded by V and J family genes previously shown to be also used in rearranged Ig loci of MALT B cell lymphomas. In summary, mucosal iNOS+ PC producing H. pylori-specific Ig accumulate in infection and appear to be a product of T cell-dependent B cell maturation. Moreover, the Ig's molecular features partly resembled that of MALT B cell lymphoma Ig genes, suggestive of a mechanism in which a progressive molecular evolution of pathogen-specific B cells to MALT B cell lymphoma occurs.


Assuntos
Infecções por Helicobacter/imunologia , Helicobacter pylori/fisiologia , Mucosa Intestinal/imunologia , Linfoma de Zona Marginal Tipo Células B/imunologia , Plasmócitos/imunologia , Antro Pilórico/imunologia , Linfócitos T/imunologia , Adulto , Proteínas de Bactérias/imunologia , Doença Crônica , Epitopos , Feminino , Humanos , Imunoglobulinas/metabolismo , Lipopolissacarídeos/imunologia , Linfoma de Zona Marginal Tipo Células B/genética , Masculino , Pessoa de Meia-Idade , Óxido Nítrico Sintase Tipo II/metabolismo , Hipermutação Somática de Imunoglobulina , Adulto Jovem
11.
Sci Rep ; 9(1): 7570, 2019 05 28.
Artigo em Inglês | MEDLINE | ID: mdl-31138833

RESUMO

A number of recent studies have shown the importance of the mammalian gut microbiome in host health. In the context of endangered species, a few studies have examined the relationship between the gut microbiome in wild versus captive populations due to digestive and other health issues. Unfortunately, the results seem to vary across taxa in terms of captive animals having higher, lower, or equivalent microbiome diversity relative to their wild counterparts. Here, we focus on the black rhinoceros as captive animals suffer from a number of potentially dietary related health effects. We compared gut microbiomes of wild and captive black rhinos to test for differences in taxonomic diversity (alpha and beta) and in functional diversity of the microbiome. We incorporated a more powerful metagenomic shotgun sequencing approach rather than a targeted amplification of the 16S gene for taxonomic assignment of the microbiome. Our results showed no significant differences in the alpha diversity levels between wild and captive black rhinos, but significant differences in beta diversity. We found that bacterial taxa traditionally associated with ruminant guts of domesticated animals had higher relative abundances in captive rhinos. Our metagenomic sequencing results suggest that unknown gut microbes of wild rhinos are being replaced by those found in conventional human-domesticated livestock. Wild rhinos have significantly different functional bacterial communities compared to their captive counterparts. Functional profiling results showed greater abundance of glycolysis and amino acid synthesis pathways in captive rhino microbiomes, representing an animal receiving sub-optimal nutrition with a readily available source of glucose but possibly an imbalance of necessary macro and micronutrients. Given the differences observed between wild and captive rhino gut microbiomes, we make a number of recommendations for potentially modifying captive gut microbiome to better reflect their wild counterparts and thereby hopefully improve overall rhino health in captivity.


Assuntos
Microbioma Gastrointestinal/genética , Microbiota/genética , Perissodáctilos/microbiologia , Animais , Animais Selvagens/microbiologia , Animais de Zoológico/microbiologia , Fezes/microbiologia , Mamíferos/microbiologia
12.
Chimia (Aarau) ; 73(4): 277-282, 2019 Apr 24.
Artigo em Inglês | MEDLINE | ID: mdl-30975256

RESUMO

Equipping a polymeric material with the ability to heal an inflicted damage is a crucial advantage for many applications. The incorporation of reversible and dynamic supramolecular interactions into polymeric systems has proven to be a promising route towards such materials. In this article, recent developments in the field of healable materials are highlighted with a particular focus on the design principles, driving forces, and mechanisms that allow healing to occur.

13.
Chimia (Aarau) ; 73(1): 7-11, 2019 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-30813988

RESUMO

While coupling mechanical and chemical processes is widespread in living organisms, the idea to harness the mechanically induced dissociation of weak covalent and non-covalent bonds to create artificial materials that respond to mechanical stimulation has only recently gained attention. Here we summarize our activities that mainly revolve around the exploitation of non-covalent interactions in (supramolecular) polymeric materials with the goal to translate mechanical stresses into useful, pre-defined events. Focusing on mechano- chromic polymers that alter their optical absorption or fluorescence properties, several new operating principles, mechanosensitive entities, and materials systems were developed. Such materials are expected to be useful for technical applications that range from the detection of very small forces in biological systems to the monitoring of degradation processes and damage in coatings and structural objects.

14.
Clin Nutr ; 38(2): 891-896, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-29606602

RESUMO

BACKGROUND & AIMS: The adductor pollicis muscle thickness (APMT) is a promising method for evaluation of muscle loss and, consequently, malnutrition in adult and elderly patients. However, to date, there have been no studies of its applicability to the pediatric population. Within this context, we sought to evaluate the association of APMT with anthropometric variables, body mass index (BMI), pediatric Subjective Global Assessment (SGA) of nutrition, nutritional screening, and clinical outcomes in hospitalized pediatric patients. METHODS: This was a cross-sectional study of inpatients aged 4-8.9 years, recruited via convenience sampling from a pediatric hospital in Porto Alegre, Rio Grande do Sul, Brazil. Data collection took place between December 2014 and February 2016. Patients admitted to the intensive care unit, those unable to feed orally, and those with cerebral palsy or Down syndrome were excluded from the study. General and socioeconomic information was collected and the SGA Ped and STRONGkids were administered at hospital admission. Clinical data were collected from the electronic medical record. Anthropometric parameters and APMT were measured by properly calibrated examiners. Data analysis was carried out in SPSS version 21.0. The significance level was set at 5%. RESULTS: The sample consisted of 447 patients. Most (55.9%) were male; the mean age was 6.2 ± 1.4 years. Low APMT was significantly associated with underweight, short stature, low body fat percentage, and poor muscle reserve (p < 0.001). There were also significant associations of moderate and severe malnutrition (assessed by the SGA Ped) and high nutritional risk (assessed by the STRONGkids instrument) with reduced APMT (p < 0.001). Regarding clinical outcomes, a longer hospital stay was observed in patients with reduced APMT (p = 0.001). A receiver operating characteristic (ROC) curve, plotted considering the SGA Ped as the gold standard, suggested APMT cutoff points of 10.2 mm for boys and 9.5 mm for girls. Stratification by age yielded APMT cutoff points of 9.8 mm for boys younger than 6 years and 10.2 mm for those older than 6 years, and 9.2 mm and 9.8 mm for girls younger and older than 6 years, respectively. CONCLUSION: The APMT is an efficient parameter for the detection of malnutrition in hospitalized pediatric patients.


Assuntos
Hospitalização , Músculo Esquelético/fisiologia , Avaliação Nutricional , Estado Nutricional/fisiologia , Polegar/fisiologia , Criança , Transtornos da Nutrição Infantil/diagnóstico , Pré-Escolar , Estudos Transversais , Feminino , Humanos , Masculino , Curva ROC
15.
Front Microbiol ; 9: 2008, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30210478

RESUMO

The cell surface of the oral pathogen Tannerella forsythia is heavily glycosylated with a unique, complex decasaccharide that is O-glycosidically linked to the bacterium's abundant surface (S-) layer, as well as other proteins. The S-layer glycoproteins are virulence factors of T. forsythia and there is evidence that protein O-glycosylation underpins the bacterium's pathogenicity. To elucidate the protein O-glycosylation pathway, genes suspected of encoding pathway components were first identified in the genome sequence of the ATCC 43037 type strain, revealing a 27-kb gene cluster that was shown to be polycistronic. Using a gene deletion approach targeted at predicted glycosyltransferases (Gtfs) and methyltransferases encoded in this gene cluster, in combination with mass spectrometry of the protein-released O-glycans, we show that the gene cluster encodes the species-specific part of the T. forsythia ATCC 43037 decasaccharide and that this is assembled step-wise on a pentasaccharide core. The core was previously proposed to be conserved within the Bacteroidetes phylum, to which T. forsythia is affiliated, and its biosynthesis is encoded elsewhere on the bacterial genome. Next, to assess the prevalence of protein O-glycosylation among Tannerella sp., the publicly available genome sequences of six T. forsythia strains were compared, revealing gene clusters of similar size and organization as found in the ATCC 43037 type strain. The corresponding region in the genome of a periodontal health-associated Tannerella isolate showed a different gene composition lacking most of the genes commonly found in the pathogenic strains. Finally, we investigated whether differential cell surface glycosylation impacts T. forsythia's overall immunogenicity. Release of proinflammatory cytokines by dendritic cells (DCs) upon stimulation with defined Gtf-deficient mutants of the type strain was measured and their T cell-priming potential post-stimulation was explored. This revealed that the O-glycan is pivotal to modulating DC effector functions, with the T. forsythia-specific glycan portion suppressing and the pentasaccharide core activating a Th17 response. We conclude that complex protein O-glycosylation is a hallmark of pathogenic T. forsythia strains and propose it as a valuable target for the design of novel antimicrobials against periodontitis.

16.
Vet Parasitol ; 255: 69-73, 2018 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-29773139

RESUMO

The utility of therapeutic vaccination of bulls against Tritrichomonas foetus has been advocated in previous studies, but anecdotal reports suggest this practice does not clear infections and may additionally confound diagnostic testing by reducing parasite burdens below detectable limits. The objective of this study was to characterize the systemic humoral immune response to therapeutic vaccination in T. foetus-infected bulls over a period of four months using an indirect ELISA and to compare the dynamics of this response to culture and PCR results to establish the existence of a relationship (or lack thereof) between immunization and infection status. A study population of 4- to 6-year-old T. foetus-infected beef bulls (n = 20) was divided equally into a treatment group and a control group. The treatment group received two doses of commercially prepared whole cell killed vaccine 2 weeks apart while the control group received injections of vaccine diluent. Blood samples were collected at each injection and at 4 subsequent dates every 4 weeks thereafter (i.e. 0, 2, 6, 10, 14, and 18 wks) to measure IgG1 and IgG2 antibody subisotype response via an indirect ELISA. Preputial smegma samples were collected at the four monthly intervals following vaccination for diagnosis of infection via InPouch™ culture, Modified Diamond's Medium (MDM) culture, and PCR. Humoral response for both IgG isotypes from week 2 through week 18 were significantly increased in vaccinates compared to controls. No significant decrease in infection prevalence was detected in the treatment group for any of the diagnostic methods used. The apparent lack of pathogen clearance during a stimulated immune response suggests that therapeutic vaccination may not be a useful T. foetus management practice.


Assuntos
Imunidade Humoral , Infecções Protozoárias em Animais/prevenção & controle , Vacinas Protozoárias/imunologia , Tritrichomonas foetus/imunologia , Vacinação/veterinária , Animais , Anticorpos Antiprotozoários/sangue , Bovinos , Imunoglobulina G/sangue , Masculino , Infecções Protozoárias em Animais/imunologia
17.
J Immunol ; 197(5): 1801-8, 2016 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-27456483

RESUMO

The mucosal immune system is relevant for homeostasis, immunity, and also pathological conditions in the gastrointestinal tract. Inducible NO synthase (iNOS)-dependent production of NO is one of the factors linked to both antimicrobial immunity and pathological conditions. Upregulation of iNOS has been observed in human Helicobacter pylori infection, but the cellular sources of iNOS are ill defined. Key differences in regulation of iNOS expression impair the translation from mouse models to human medicine. To characterize mucosal iNOS-producing leukocytes, biopsy specimens from H. pylori-infected patients, controls, and participants of a vaccination trial were analyzed by immunohistochemistry, along with flow cytometric analyses of lymphocytes for iNOS expression and activity. We newly identified mucosal IgA-producing plasma cells (PCs) as one major iNOS(+) cell population in H. pylori-infected patients and confirmed intracellular NO production. Because we did not detect iNOS(+) PCs in three distinct infectious diseases, this is not a general feature of mucosal PCs under conditions of infection. Furthermore, numbers of mucosal iNOS(+) PCs were elevated in individuals who had cleared experimental H. pylori infection compared with those who had not. Thus, IgA(+) PCs expressing iNOS are described for the first time, to our knowledge, in humans. iNOS(+) PCs are induced in the course of human H. pylori infection, and their abundance seems to correlate with the clinical course of the infection.


Assuntos
Helicobacter pylori/imunologia , Imunoglobulina A/imunologia , Óxido Nítrico Sintase Tipo II/biossíntese , Plasmócitos/enzimologia , Plasmócitos/imunologia , Biópsia , Feminino , Mucosa Gástrica/microbiologia , Infecções por Helicobacter/imunologia , Infecções por Helicobacter/microbiologia , Humanos , Imunoglobulina A/biossíntese , Imuno-Histoquímica , Masculino , Óxido Nítrico/metabolismo , Estudos Prospectivos , Antro Pilórico/microbiologia , Antro Pilórico/patologia
18.
Sci. med. (Porto Alegre, Online) ; 25(3): ID21948, jul.-set.2015.
Artigo em Português | LILACS | ID: biblio-832157

RESUMO

Objetivos: Comparar a Avaliação Nutricional Subjetiva Global (ANSG) e a Triagem de Risco para Estado Nutricional e Crescimento (STRONGkids) com a avaliação antropométrica, na admissão hospitalar, e associá-las ao tempo de internação em crianças hospitalizadas. Métodos: Estudo transversal com pacientes de 4 a 8,9 anos internados em um hospital pediátrico de Porto Alegre, Rio Grande do Sul. A amostragem foi realizada por conveniência, e a coleta de dados ocorreu entre junho e outubro de 2014. Não foram incluídos pacientes internados em Unidade de Terapia Intensiva e aqueles sem condições de alimentação por via oral. Foram coletadas informações gerais e socioeconômicas, e aplicados os questionários de ANSG e STRONGkids na admissão hospitalar. Dados clínicos e antropométricos foram coletados do prontuário eletrônico. Resultados: Avaliaram-se 317 pacientes com idade média de 76,1±17,5 meses e, na maioria, com motivo de internação cirúrgico (21,5%). Segundo a avaliação antropométrica, 5% dos pacientes eram desnutridos, 74,1% eram eutróficos e 20,8% apresentavam excesso de peso. Houve associação significativa entre a desnutrição classificada pela avaliação antropométrica e a desnutrição moderada e grave definida pela ANSG (p<0,001). Também houve associação significativa entre excesso de peso, eutrofia e desnutrição, classificados pela avaliação antropométrica, e risco nutricional baixo, médio e alto, respectivamente (p<0,001). Houve concordância significativa, porém muito fraca, entre a STRONGkids e a avaliação antropométrica (kappa=0,148; p=0,001). Conclusões: Todas as avaliações feitas por meio das ferramentas testadas associaram-se (embora em fraca intensidade) com o tempo de internação hospitalar. Além disso, a STRONGkids apresentou maior concordância, embora ainda fraca, com a avaliação antropométrica quando comparada à ANSG. São necessários mais estudos verificando a concordância dessas ferramentas com outros métodos objetivos de avaliação nutricional.


Aims: To compare the Subjective Global Nutritional Assessment (SGNA) and the Screening Tool for Risk on Nutritional Status and Growth (STRONGkids) protocols with anthropometric measurements at admission, and associate them to length of stay in hospitalized children. Methods: Cross-sectional study with patients from four to 8.9 years admitted to a pediatric hospital in Porto Alegre, Rio Grande do Sul, Brazil. The sample was selected by convenience, and data collection occurred between June and October 2014. Patients in the Intensive Care Unit and those unable to feed orally were not included. We collected general and socioeconomic information and applied STRONGkids and SGNA protocols at admission. Clinical and anthropometric data were retrieved from electronic medical records. Results: We evaluated 317 patients with a mean age of 76.1±17.5 months, most of them admitted for surgery (21.5%). According to anthropometric measurements, 5% of patients were malnourished, 74.1% had normal weight and 20.8% were overweight. There was a statistically significant association between malnutrition classified by anthropometric measurements and moderate and severe malnutrition defined by SGNA (p<0.001). There was also a significant association between overweight, normal weight and malnutrition classified by anthropometric measurements and low, medium and high nutritional risk, respectively (p<0.001). There was a statistically significant agreement, although very weak, between STRONGkids and anthropometric measurements (kappa=0.148; p=0.001). Conclusions: All protocols were associated (though in low intensity) to length of hospital stay. In addition, STRONGkids showed greater agreement, although still weak, with anthropometric measurements when compared to the SGNA. Further studies are needed to verify the agreement of these protocols with other objective methods of nutritional assessment.


Assuntos
Humanos , Masculino , Feminino , Pré-Escolar , Criança , Avaliação Nutricional , Criança Hospitalizada , Desnutrição , Antropometria , Estudos Transversais , Tempo de Internação
19.
Org Biomol Chem ; 13(28): 7711-9, 2015 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-26083675

RESUMO

A water-soluble benzene-1,3,5-tricarboxamide (BTA) derivative that self-assembles into one-dimensional, helical, supramolecular polymers is functionalised at the periphery with one L-proline moiety. In water, the BTA-derivative forms micrometre long supramolecular polymers, which are stabilised by hydrophobic interactions and directional hydrogen bonds. Furthermore, we co-assemble a catalytically inactive, but structurally similar, BTA with the L-proline functionalised BTA to create co-polymers. This allows us to assess how the density of the L-proline units along the supramolecular polymer affects its activity and selectivity. Both the supramolecular polymers and co-polymers show high activity and selectivity as catalysts for the aldol reaction in water when using p-nitrobenzaldehyde and cyclohexanone as the substrates for the aldol reaction. After optimisation of the reaction conditions, a consistent conversion of 92 ± 7%, deanti of 92 ± 3%, and eeanti of 97 ± 1% are obtained with a concentration of L-proline as low as 1 mol%.


Assuntos
Benzaldeídos/química , Benzamidas/química , Cicloexanonas/química , Polímeros/química , Água/química , Benzamidas/síntese química , Catálise , Substâncias Macromoleculares/síntese química , Substâncias Macromoleculares/química , Estrutura Molecular , Polímeros/síntese química
20.
Vet Microbiol ; 172(1-2): 301-8, 2014 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-24930984

RESUMO

Johne's disease (JD), caused by Mycobacterium avium subsp. paratuberculosis (MAP), can cause considerable economic losses in affected herds. Early diagnosis of JD is hampered by the chronic nature of the disease with a slow subclincal progression. The aim of the present study was to challenge the hypothesis that lymphatic fluid is of diagnostic value in the early stages of the disease. Lymphatic fluid from 122 animals was collected and tested for MAP by nested PCR for IS900 and compared to the results of testing for MAP in feces (culture), blood and milk (ELISA) in 110 of these samples. MAP was detected by PCR in 27.1% of the lymph samples. Agreement between the tests was poor: 6.9% of the lymph positive cows were also positive in all other tests applied, and 69.0% had negative results in fecal culture, blood and milk ELISA. Resampling of 25 cows after 8 to 12 and 16 to 20 months revealed 20.0% lymph positive animals at the first, 5.5% at the second and 27.8% at the third sampling, respectively. Only one cow showed positive lymph-PCR results at more than one sampling date. Lymph-positive cows had a 7.2 times greater likelihood of being culled within 8 to 12 months after sampling, compared to negative cows, mainly due to other health issues than JD. It can be concluded, that lymphatic fluid might be promising for the detection of early MAP-infection in cows, but further studies to elucidate the potential of this diagnostic approach are needed.


Assuntos
Anticorpos Antibacterianos/análise , Doenças dos Bovinos/diagnóstico , Linfa/microbiologia , Mycobacterium avium subsp. paratuberculosis/imunologia , Paratuberculose/diagnóstico , Animais , Anticorpos Antibacterianos/sangue , Bovinos , Doenças dos Bovinos/imunologia , Doenças dos Bovinos/microbiologia , Fezes/microbiologia , Feminino , Leite/microbiologia , Paratuberculose/imunologia , Paratuberculose/microbiologia
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