Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 261
Filtrar
Mais filtros

Base de dados
Tipo de documento
Intervalo de ano de publicação
1.
Epilepsy Behav ; 151: 109617, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38219607

RESUMO

PURPOSE: People living with epilepsy (PLWE) have a higher prevalence of mental health comorbidities and poorer psychosocial outcomes compared to the general population. The aim of this study was to examine psychosocial outcomes, mental health, healthcare accessibility, and seizure burden in PLWE during the COVID-19 pandemic. METHODS: We conducted a cross-sectional study of adults with epilepsy treated in an urban multicenter health system from 2021 to 2022. A standardized questionnaire assessed for COVID-19 history, comorbidities, access to antiseizure medications (ASMs) and neurological care, seizure burden, and psychosocial outcomes (e.g., employment, social and financial support). The Patient Health Questionnaire-9 (PHQ-9) and Generalized Anxiety Disorder-7 (GAD-7) were administered to evaluate for depression and anxiety. Frequency and proportions for categorical variables and median and interquartile ranges for continuous variables were calculated. RESULTS: Fifty-five PLWE participated (95 % response rate). Median age was 40 years (IQR 31.5-66.5), 61.8 % were women, 47.3 % had a bachelor's degree or higher and 29.1 % each had Medicaid and Medicare insurance. Race (from highest to lowest %) was: 32.7 % White, 20 % Black, 20 % Latinx, 14.5 % Asian, and 12.7 % selected "other" or "prefer not to say." COVID-19 had been diagnosed in 21.8 % of participants. Symptoms of anxiety and depression were self-reported by 43.6 % and 34.5 % of patients, respectively, with many describing this symptom as new post-pandemic (37.5 % and 31.6 %, respectively). Using validated scales, 52.7 % had depression (PHQ-9 score ≥ 5) with 30.9 % having moderate/severe depression (PHQ-9 score ≥ 10), while 29.1 % had probable generalized anxiety disorder (GAD-7 score ≥ 8). Seizure burden increased in 21.8 % of participants, while 20 % reported fewer seizures and 29.1 % were seizure free since the COVID-19 pandemic. Economic impacts of the pandemic included job loss (25 % amongst those employed at onset of pandemic), new or worsened financial difficulties (40 %), and new or worsened social support issues (30.9 %). Of all participants, 18.2 % reported difficulties accessing ASMs and 25.5 % cancelled visits, but of those with cancelled visits, 78.6 % had their appointments rescheduled as a telehealth visit. CONCLUSION: Our cohort of PLWE experienced some challenges during the COVID-19 pandemic including poorer mental health and financial and employment-related stressors. Encouragingly, healthcare access was relatively spared during the COVID-19 crisis, with some patients even reporting a reduction in seizure burden. However, PLWE require ongoing psychosocial support with particular attention to decompensation of mental health and social stressors that may be exacerbated by the COVID-19 pandemic.


Assuntos
COVID-19 , Epilepsia , Adulto , Idoso , Feminino , Humanos , Masculino , Ansiedade/epidemiologia , COVID-19/epidemiologia , Estudos Transversais , Depressão/epidemiologia , Epilepsia/epidemiologia , Epilepsia/terapia , Acessibilidade aos Serviços de Saúde , Medicare , Saúde Mental , Pandemias , Convulsões , Estados Unidos/epidemiologia , Pessoa de Meia-Idade
2.
Microbiology (Reading) ; 169(1)2023 01.
Artigo em Inglês | MEDLINE | ID: mdl-36748549

RESUMO

While recent efforts to catalogue Earth's microbial diversity have focused upon surface and marine habitats, 12-20 % of Earth's biomass is suggested to exist in the terrestrial deep subsurface, compared to ~1.8 % in the deep subseafloor. Metagenomic studies of the terrestrial deep subsurface have yielded a trove of divergent and functionally important microbiomes from a range of localities. However, a wider perspective of microbial diversity and its relationship to environmental conditions within the terrestrial deep subsurface is still required. Our meta-analysis reveals that terrestrial deep subsurface microbiota are dominated by Betaproteobacteria, Gammaproteobacteria and Firmicutes, probably as a function of the diverse metabolic strategies of these taxa. Evidence was also found for a common small consortium of prevalent Betaproteobacteria and Gammaproteobacteria operational taxonomic units across the localities. This implies a core terrestrial deep subsurface community, irrespective of aquifer lithology, depth and other variables, that may play an important role in colonizing and sustaining microbial habitats in the deep terrestrial subsurface. An in silico contamination-aware approach to analysing this dataset underscores the importance of downstream methods for assuring that robust conclusions can be reached from deep subsurface-derived sequencing data. Understanding the global panorama of microbial diversity and ecological dynamics in the deep terrestrial subsurface provides a first step towards understanding the role of microbes in global subsurface element and nutrient cycling.


Assuntos
Gammaproteobacteria , Microbiota , Microbiologia da Água , Bactérias/genética , Microbiota/genética , Biomassa , Metagenômica , RNA Ribossômico 16S
3.
J Appl Microbiol ; 127(5): 1479-1489, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31301204

RESUMO

AIMS: Development of biomineralization technologies has largely focused on microbially induced carbonate precipitation (MICP) via Sporosarcina pasteurii ureolysis; however, as an obligate aerobe, the general utility of this organism is limited. Here, facultative and anaerobic haloalkaliphiles capable of ureolysis were enriched, identified and then compared to S. pasteurii regarding biomineralization activities. METHODS AND RESULTS: Anaerobic and facultative enrichments for haloalkaliphilic and ureolytic micro-organisms were established from sediment slurries collected at Soap Lake (WA). Optimal pH, temperature and salinity were determined for highly ureolytic enrichments, with dominant populations identified via a combination of high-throughput SSU rRNA gene sequencing, clone libraries and Sanger sequencing of isolates. The enrichment cultures consisted primarily of Sporosarcina- and Clostridium-like organisms. Ureolysis rates and direct cell counts in the enrichment cultures were comparable to the S. pasteurii (strain ATCC 11859) type strain. CONCLUSIONS: Ureolysis rates from both facultatively and anaerobically enriched haloalkaliphiles were either not statistically significantly different to, or statistically significantly higher than, the S. pasteurii (strain ATCC 11859) rates. Work here concludes that extreme environments can harbour highly ureolytic active bacteria with potential advantages for large scale applications, such as environments devoid of oxygen. SIGNIFICANCE AND IMPACT OF THE STUDY: The bacterial consortia and isolates obtained add to the possible suite of organisms available for MICP implementation, therefore potentially improving the economics and efficiency of commercial biomineralization.


Assuntos
Álcalis/metabolismo , Carbonato de Cálcio/metabolismo , Sporosarcina/metabolismo , Ureia/metabolismo , Anaerobiose , Bactérias/metabolismo , Carbonato de Cálcio/química , Sedimentos Geológicos/microbiologia , Consórcios Microbianos , Sporosarcina/genética , Sporosarcina/isolamento & purificação
4.
Integr Org Biol ; 6(1): obae009, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38699511

RESUMO

High-resolution imaging, 3D modeling, and quantitative analyses are equipping evolutionary biologists with new approaches to understanding the variation and evolution of the musculoskeletal system. However, challenges with interpreting DiceCT data and higher order use of modeled muscles have not yet been fully explored, and the error in and accuracy of some digital methods remain unclear. West Indian Anolis lizards are a model clade for exploring patterns in functional adaptation, ecomorphology, and sexual size dimorphism in vertebrates. These lizards possess numerous jaw muscles with potentially different anatomies that sculpt the adductor chamber of the skull. Here we test approaches to quantifying the musculoskeletal shape of the heads of two species of Anolis: A. pulchellus and A. sagrei. We employ comparative approaches such as DiceCT segmentation of jaw muscles, 3D surface attachment mapping, and 3D landmarking with the aim of exploring muscle volumes, 3D muscle fiber architecture, and sexual dimorphism of the skull. We then compare sources of measurement error in these 3D analyses while also presenting new 3D musculoskeletal data from the Anolis feeding apparatus. These findings demonstrate the accessibility and repeatability of these emerging techniques as well as provide details regarding the musculoskeletal anatomy of the heads of A. pulchellus and A. sagrei which show potential for further research of comparative biomechanics and evolution in the clade.

5.
Appl Microbiol Biotechnol ; 97(15): 7049-59, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23771779

RESUMO

Phaeodactylum tricornutum is a marine diatom in the class Bacillariophyceae and is important ecologically and industrially with regards to ocean primary production and lipid accumulation for biofuel production, respectively. Triacylglyceride (TAG) accumulation has been reported in P. tricornutum under different nutrient stresses, and our results show that lipid accumulation can occur with nitrate or phosphate depletion. However, greater lipid accumulation was observed when both nutrients were depleted as observed using a Nile Red assay and fatty acid methyl ester (FAME) profiles. Nitrate depletion had a greater effect on lipid accumulation than phosphate depletion. Lipid accumulation in P. tricornutum was arrested upon resupplementation with the depleted nutrient. Cells depleted of nitrogen showed a distinct shift from a lipid accumulation mode to cellular growth post-resupplementation with nitrate, as observed through increased cell numbers and consumption of accumulated lipid. Phosphate depletion caused lipid accumulation that was arrested upon phosphate resupplementation. The cessation of lipid accumulation was followed by lipid consumption without an increase in cell numbers. Cells depleted in both nitrate and phosphate displayed cell growth upon the addition of both nitrate and phosphate and had the largest observed lipid consumption upon resupplementation. These results indicate that phosphate resupplementation can shut down lipid accumulation but does not cause cells to shift into cellular growth, unlike nitrate resupplementation. These data suggest that nutrient resupplementation will arrest lipid accumulation and that switching between cellular growth and lipid accumulation can be regulated upon the availability of nitrogen and phosphorus.


Assuntos
Biocombustíveis , Diatomáceas/metabolismo , Meios de Cultura , Ésteres , Ácidos Graxos/metabolismo , Triglicerídeos/metabolismo
6.
Appl Environ Microbiol ; 77(13): 4647-56, 2011 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-21602393

RESUMO

Although little is known of potential function for conserved signaling proteins, it is hypothesized that such proteins play important roles to coordinate cellular responses to environmental stimuli. In order to elucidate the function of a putative sensory box protein (PAS domains) in Shewanella oneidensis MR-1, the physiological role of SO3389 was characterized. The predicted open reading frame (ORF) encodes a putative sensory box protein that has PAS, GGDEF, and EAL domains, and an in-frame deletion mutant was constructed (ΔSO3389) with approximately 95% of the ORF deleted. Under aerated conditions, wild-type and mutant cultures had similar growth rates, but the mutant culture had a lower growth rate under static, aerobic conditions. Oxygen consumption rates were lower for mutant cultures (1.5-fold), and wild-type cultures also maintained lower dissolved oxygen concentrations under aerated growth conditions. When transferred to anoxic conditions, the mutant did not grow with fumarate, iron(III), or dimethyl sulfoxide (DMSO) as electron acceptors. Biochemical assays demonstrated the expression of different c-type cytochromes as well as decreased fumarate reductase activity in the mutant transferred to anoxic growth conditions. Transcriptomic studies showed the inability of the mutant to up-express and down-express genes, including c-type cytochromes (e.g., SO4047/SO4048, SO3285/SO3286), reductases (e.g., SO0768, SO1427), and potential regulators (e.g., SO1329). The complemented strain was able to grow when transferred from aerobic to anoxic growth conditions with the tested electron acceptors. The modeled structure for the SO3389 PAS domains was highly similar to the crystal structures of FAD-binding PAS domains that are known O2/redox sensors. Based on physiological, genomic, and bioinformatic results, we suggest that the sensory box protein, SO3389, is an O2/redox sensor that is involved in optimization of aerobic growth and transitions to anoxia in S. oneidensis MR-1.


Assuntos
Proteínas de Bactérias/metabolismo , Shewanella/crescimento & desenvolvimento , Shewanella/metabolismo , Anaerobiose , Proteínas de Bactérias/química , Proteínas de Bactérias/genética , Citocromos c/metabolismo , Dimetil Sulfóxido/metabolismo , Compostos Férricos/metabolismo , Fumaratos/metabolismo , Perfilação da Expressão Gênica , Teste de Complementação Genética , Modelos Moleculares , Fases de Leitura Aberta , Oxigênio/metabolismo , Estrutura Terciária de Proteína , Deleção de Sequência , Shewanella/genética
7.
J Cell Biol ; 141(1): 143-53, 1998 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-9531554

RESUMO

We have identified a novel generally expressed homologue of the erythrocyte membrane cytoskeletal protein 4.1, named 4.1G, based on the interaction of its COOH-terminal domain (CTD) with the immunophilin FKBP13. The 129-amino acid peptide, designated 4.1G-CTD, is the first known physiologic binding target of FKBP13. FKBP13 is a 13-kD protein originally identified by its high affinity binding to the immunosuppressant drugs FK506 and rapamycin (Jin, Y., M.W. Albers, W.S. Lane, B.E. Bierer, and S.J. Burakoff. 1991. Proc. Natl. Acad. Sci. USA. 88:6677- 6681); it is a membrane-associated protein thought to function as an ER chaperone (Bush, K.T., B.A. Henrickson, and S.K. Nigam. 1994. Biochem. J. [Tokyo]. 303:705-708). We report the specific association of FKBP13 with 4.1G-CTD based on yeast two-hybrid, in vitro binding and coimmunoprecipitation experiments. The histidyl-proline moiety of 4.1G-CTD is required for FKBP13 binding, as indicated by yeast experiments with truncated and mutated 4.1G-CTD constructs. In situ hybridization studies reveal cellular colocalizations for FKBP13 and 4.1G-CTD throughout the body during development, supporting a physiologic role for the interaction. Interestingly, FKBP13 cofractionates with the red blood cell homologue of 4.1 (4.1R) in ghosts, inside-out vesicles, and Triton shell preparations. The identification of FKBP13 in erythrocytes, which lack ER, suggests that FKBP13 may additionally function as a component of membrane cytoskeletal scaffolds.


Assuntos
Encéfalo/metabolismo , Proteínas de Transporte/metabolismo , Proteínas do Citoesqueleto , Membrana Eritrocítica/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Proteínas de Membrana/metabolismo , Neuropeptídeos , Proteínas de Saccharomyces cerevisiae , Proteínas de Ligação a Tacrolimo , Fatores de Transcrição , Envelhecimento/metabolismo , Sequência de Aminoácidos , Animais , Sítios de Ligação , Encéfalo/embriologia , Encéfalo/crescimento & desenvolvimento , Proteínas de Transporte/biossíntese , Proteínas de Transporte/química , Clonagem Molecular , Proteínas de Ligação a DNA , Proteínas Fúngicas/metabolismo , Biblioteca Gênica , Hipocampo/metabolismo , Proteínas de Membrana/biossíntese , Proteínas de Membrana/química , Dados de Sequência Molecular , Especificidade de Órgãos , Ratos , Ratos Sprague-Dawley , Proteínas Recombinantes de Fusão/química , Proteínas Recombinantes de Fusão/metabolismo , Saccharomyces cerevisiae , Alinhamento de Sequência , Homologia de Sequência de Aminoácidos , Tacrolimo/metabolismo
8.
Palliat Med ; 23(6): 512-7, 2009 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-19460834

RESUMO

Palliative care of patients with cystic fibrosis (CF) is often undertaken by CF teams rather than palliative care teams because of the specialist nature of the disease and the potential role of lung transplantation. We developed an integrated model of provision of palliative care whereby most care is delivered by the CF team using palliative guidelines and pathways, with additional support available from the specialist palliative care team when needed. We report our experience of the terminal care of 40 patients with CF with regard to the circumstances of death, lung transplantation status, specific symptoms and provision of palliative treatments. The transition from disease modifying treatments to palliative care was particularly complex. Patients had a high level of symptoms requiring palliation and most died in hospital. Palliative care is a crucial component of a CF service and requires the specialist skills of both the CF and palliative care teams.


Assuntos
Continuidade da Assistência ao Paciente/organização & administração , Fibrose Cística/terapia , Prestação Integrada de Cuidados de Saúde/organização & administração , Avaliação das Necessidades/organização & administração , Cuidados Paliativos/organização & administração , Equipe de Assistência ao Paciente/organização & administração , Adolescente , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Cuidados Paliativos/normas , Estudos Retrospectivos , Doente Terminal , Adulto Jovem
9.
FEMS Microbiol Ecol ; 94(12)2018 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-30265315

RESUMO

Subsurface environments contain a large proportion of planetary microbial biomass and harbor diverse communities responsible for mediating biogeochemical cycles important to groundwater used by human society for consumption, irrigation, agriculture and industry. Within the saturated zone, capillary fringe and vadose zones, microorganisms can reside in two distinct phases (planktonic or biofilm), and significant differences in community composition, structure and activity between free-living and attached communities are commonly accepted. However, largely due to sampling constraints and the challenges of working with solid substrata, the contribution of each phase to subsurface processes is largely unresolved. Here, we synthesize current information on the diversity and activity of shallow freshwater subsurface habitats, discuss the challenges associated with sampling planktonic and biofilm communities across spatial, temporal and geological gradients, and discuss how biofilms may be constrained within shallow terrestrial subsurface aquifers. We suggest that merging traditional activity measurements and sequencing/-omics technologies with hydrological parameters important to sediment biofilm assembly and stability will help delineate key system parameters. Ultimately, integration will enhance our understanding of shallow subsurface ecophysiology in terms of bulk-flow through porous media and distinguish the respective activities of sessile microbial communities from more transient planktonic communities to ecosystem service and maintenance.


Assuntos
Bactérias/crescimento & desenvolvimento , Biofilmes/crescimento & desenvolvimento , Água Doce/microbiologia , Sedimentos Geológicos/microbiologia , Água Subterrânea/microbiologia , Plâncton/crescimento & desenvolvimento , Bactérias/classificação , Humanos , Hidrologia , Microbiota , Plâncton/classificação
10.
J Microbiol Methods ; 65(1): 144-52, 2006 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-16083982

RESUMO

The goal of this research was to investigate the influence of the error rate of sequence determination on the differentiation of cloned SSU rRNA gene sequences for assessment of community structure. SSU rRNA cloned sequences from groundwater samples that represent different bacterial divisions were sequenced multiple times with the same sequencing primer. From comparison of sequence alignments with unedited data, confidence intervals were obtained from both a 'double binomial' model of sequence comparison and by non-parametric methods. The results indicated that similarity values below 0.9946 are likely derived from dissimilar sequences at a confidence level of 0.95, and not sequencing errors. The results confirmed that screening by direct sequence determination could be reliably used to differentiate at the species level. However, given sequencing errors comparable to those seen in this study, sequences with similarities above 0.9946 should be treated as the same sequence if a 95% confidence is desired.


Assuntos
DNA Bacteriano/genética , RNA Ribossômico/genética , Análise de Sequência de DNA/métodos , Microbiologia da Água , Sequência de Bases , Intervalos de Confiança , DNA Bacteriano/química , Água Doce , Filogenia , Reação em Cadeia da Polimerase , RNA Ribossômico/química , RNA Ribossômico 16S/química , RNA Ribossômico 16S/genética , Alinhamento de Sequência
11.
Genome Announc ; 4(6)2016 Nov 03.
Artigo em Inglês | MEDLINE | ID: mdl-27811105

RESUMO

Alkaliphilus metalliredigens strain QYMF is an anaerobic, alkaliphilic, and metal-reducing bacterium associated with phylum Firmicutes QYMF was isolated from alkaline borax leachate ponds. The genome sequence will help elucidate the role of metal-reducing microorganisms under alkaline environments, a capability that is not commonly observed in metal respiring-microorganisms.

12.
Chemosphere ; 59(7): 1015-22, 2005 May.
Artigo em Inglês | MEDLINE | ID: mdl-15823335

RESUMO

Understanding contaminant distribution is critical to selection and implementation of effective and affordable containment and remediation efforts. This article describes the characterization of soil containing thorium at a training site on Kirtland Air Force Base, Albuquerque, NM. The site has been used by the Defense Nuclear Weapons School since the early 1960's to train personnel in emergency response to nuclear weapons accidents and for characterization and containment of radioactive contamination. The purpose of work reported herein is to describe the primary location and migration pattern of 232Thorium (232Th) and 232Th progeny (decay products) at the site. Soil containing thorium oxide (ThO2) was applied to the site for approximately 30 years (early 1960-1990) and was used to simulate a plutonium release from a nuclear weapons accident. Data presented indicate that surface 232Th and 232Th progeny at approximately 5 times background levels are approaching test site boundaries. However, the data also indicate that vertical migration has not exceeded 0.9 m because of the insoluble nature of ThO2. The major mechanisms of 232Th mobility appear to be surface migration mediated by precipitation runoff and wind-blown soil.


Assuntos
Monitoramento de Radiação/métodos , Monitoramento de Radiação/estatística & dados numéricos , Poluentes Radioativos do Solo/análise , Tório/análise , New Mexico , Monitoramento de Radiação/instrumentação , Chuva , Solubilidade , Vento
13.
Genome Announc ; 3(1)2015 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-25614562

RESUMO

We report the genome sequence of Anaeromyxobacter sp. Fw109-5, isolated from nitrate- and uranium-contaminated subsurface sediment of the Oak Ridge Integrated Field-Scale Subsurface Research Challenge (IFC) site, Oak Ridge Reservation, TN. The bacterium's genome sequence will elucidate its physiological potential in subsurface sediments undergoing in situ uranium bioremediation and natural attenuation.

14.
Endocrinology ; 118(4): 1723-5, 1986 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-3948797

RESUMO

The highly conserved neurophysin associated with neurohypophysial hormones was localized in the large luteal cell of the nonpregnant cow and nonpregnant ewe with light microscopy avidin-biotin immunohistochemistry. Furthermore, with rabbit anti-oxytocin-neurophysin serum and goat anti-rabbit immunoglobulin G-colloidal gold, neurophysin was localized in the 100- to 200-nm diameter membrane-bounded secretory granules of the large luteal cells.


Assuntos
Corpo Lúteo/análise , Neurofisinas/análise , Animais , Bovinos , Corpo Lúteo/citologia , Estro , Feminino , Histocitoquímica , Ovinos
15.
Endocrinology ; 117(4): 1675-82, 1985 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-4029092

RESUMO

The ultrastructure of large and small cells from corpora lutea of pregnant cows (days 45-280) were evaluated by electron microscopy. The distinguishing features of small cells (10-15 micron in diameter) included stacks of rough endoplasmic reticulum, whorls of smooth endoplasmic reticulum, elongated mitochondria containing crystalline-like inclusions, and cytoplasmic lipid droplets. The large cells (20-50 micron in diameter) contained numerous mitochondria packed tightly together (no elongated structures), an abundance of smooth endoplasmic reticulum (no whorls), and a large number of membrane-bound secretory granules (150-300 nm in diameter). These granules appeared to be packaged in the Golgi, accumulated at a paranuclear region, and migrated as a group to the cell membrane where they were exocytosed. These granules were first observed on day 45 and increased in number to reach a peak around day 200. Lipid droplets became a common cytoplasmic inclusion in the large cells during the third trimester of pregnancy. In addition, during this stage, an electron-dense substance began to accumulate in the mitochondria to such an extent as to occlude the cristae. These mitochondria looked like large (500-1800 nm) membrane-bound granules; however, they did not undergo exocytosis. Their appearance in large cells during the last 3 months of pregnancy may reflect a change in steroid metabolism. Thus, there are two morphologically distinct cell types throughout pregnancy in the cow. The large cell containing the secretory granules underwent what appeared to be a progressive state of apparent deterioration with advancing pregnancy. The morphology of the small cell did not undergo such a dynamic change. No morphological evidence was observed that would support a transition state between the two cell types.


Assuntos
Corpo Lúteo/ultraestrutura , Grânulos Citoplasmáticos/ultraestrutura , Prenhez , Animais , Bovinos , Retículo Endoplasmático/ultraestrutura , Exocitose , Feminino , Complexo de Golgi/ultraestrutura , Microscopia Eletrônica , Mitocôndrias/ultraestrutura , Gravidez , Terceiro Trimestre da Gravidez
16.
Endocrinology ; 138(11): 4844-51, 1997 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-9348214

RESUMO

We have previously reported that bovine endometrium contains LH/human CG binding receptors and LH induces cyclooxygenase and prostaglandin production in the bovine endometrium. The present study investigated 1) whether bovine uterine vein and artery contain LH receptor messenger RNA (mRNA) and receptor protein and 2) whether LH can regulate the formation of vasoactive eicosanoids by the uterine vein. The uterine vein endothelium, but not the uterine artery, contained LH receptor mRNA transcript essentially identical to that found in the bovine corpus luteum. The uterine vein endothelium also contained a 95-kDa immunoreactive receptor protein that bound to rat anti-LH receptor antibody in Western blots. The LH receptor mRNA and LH receptor were maximally expressed in the uterine vein from cows in proestrus/estrus compared with cows in luteal or postovulatory phases. Incubation of endothelial minces of uterine vein with LH resulted in a 2-fold increase in cyclooxygenase concentration as determined by Western blot using an antibody to ram seminal vesicle cyclooxygenase. The increase in cyclooxygenase was maximal in cows in proestrus/estrus compared with postovulatory and luteal phase cows. Incubation of proestrous/estrous uterine vein or artery minces with LH or mellitin (a phospholipase A2 stimulator) caused increased production of eicosanoids. In the uterine vein, LH caused a significant increase in both PGF2alpha (basal 4.1 +/- 0.4 vs. 5.7 +/- 0.4 ng/100 mg x 6 h, P < 0.01; N = 9 cows) and PGE2 (basal 5.7 +/- 0.3 vs. 7.7 +/- 0.8 ng/100 mg x 6 h, P < 0.01; N = 6 cows) but had no effect on prostaglandin production by the artery. Mellitin increased PGF2alpha production by both uterine vein and artery minces but had no effect on PGE2 production in either tissue. Addition of steroids (progesterone, estradiol) or cytokines (tumor necrosis factor-alpha, IL-6) to the uterine vascular tissues had essentially no effect on prostanoid production. In summary, bovine uterine vein from proestrous/estrous cows expressed the LH receptor and its mRNA. Expression of the receptor may have physiological significance as LH induces cyclooxygenase and increases prostaglandin release in the uterine vein. The maximal stimulation of the receptor and its mRNA at proestrus/ estrus may serve to increase the amounts of prostanoids reaching the regressing corpus luteum either directly by increasing prostanoid production or indirectly by increasing the blood flow to the ovary.


Assuntos
Prostaglandinas/biossíntese , RNA Mensageiro/metabolismo , Receptores do LH/genética , Receptores do LH/metabolismo , Útero/irrigação sanguínea , Veias/metabolismo , Animais , Sequência de Bases , Bovinos , Dinoprosta/biossíntese , Dinoprostona/biossíntese , Indução Enzimática/fisiologia , Feminino , Hormônio Luteinizante/fisiologia , Meliteno/farmacologia , Dados de Sequência Molecular , Prostaglandina-Endoperóxido Sintases/metabolismo , Ratos , Receptores do LH/fisiologia
17.
Endocrinology ; 107(4): 869-76, 1980 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-6773748

RESUMO

Relaxin was isolated from corpora lutea of third trimester pregnant cows. Fractions having relaxin activity eluted in the 6000 and 1400 molecular weight ranges when chromatographed on Bio-Gel P-10. Both fractions were shown to inhibit spontaneous contractions of the mouse uterus, and the 6000 molecular weight fraction promoted formation of the mouse interpubic ligament. Agar diffusion studies with an antiserum to purified porcine relaxin showed a continuous precipitin line with no spurring between the two bovine relaxin fractions and NIHR-P1 porcine relaxin standard. Electrofocusing of the 6000 molecular weight fraction demonstrated three fractions which were capable of inhibiting contractions of the mouse uterus and which cross-reacted with porcine relaxin antiserum. The isoelectric points of these three fractions were 8.8, 10.1, and 11.5. Large luteal cells in corpora lutea from cows in the midtrimester of pregnancy were detected that gave a positive stain for relaxin with the immunoperoxidase method.


Assuntos
Corpo Lúteo/análise , Prenhez , Relaxina/isolamento & purificação , Animais , Bioensaio , Bovinos , Feminino , Imunodifusão , Técnicas Imunoenzimáticas , Camundongos , Peso Molecular , Contração Muscular/efeitos dos fármacos , Gravidez , Relaxina/farmacologia , Útero/efeitos dos fármacos
18.
Endocrinology ; 139(6): 2755-64, 1998 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-9607782

RESUMO

Developmental aspects of oxytocin (OT) receptors (OTR) in uterine tissues before puberty are not known. Bovine ovaries secrete some estradiol, but no progesterone, before puberty; the circulating levels of estradiol are between 1 and 3 pg/ml until puberty. Cross-bred Angus-Brahman heifers, in which puberty occurs around 12 months of age, were used to determine the concentrations of OTR from the late fetal stage to adulthood. PGF2alpha release in response to OT was determined in 3-, 6-, and 9-month-old heifers (n = 4 each). Myometrium, endometrium, and cervical mucosa were obtained from 3-week-old, 3-month-old, 6-month-old, and 9-month-old heifers and from adult cows at estrus. Whole uterus and cervix were taken from third trimester fetuses and at birth. [3H]OT binding and specificity, localization of immunoreactive (ir) OTR, OTR messenger RNA, and OT-induced release of PGF2alpha were determined. The uterus from fetuses and the neonate expressed OTR messenger RNA and bound [3H]OT. At 3 weeks of age, OTR concentrations per mg protein were very low, but at 3 months of age they had increased markedly in all three tissues. At 6 and 9 months of age, levels of OTR had risen further and were similar to those in adult cows at estrus. Prepubertal uterus also possessed separate vasopressin VP1 subtype receptors. The ir-OTR was localized in luminal epithelial cells of endometrium and cervical mucosa, most of which were ir positive, whereas in myometrium, clusters of ir-OTR-positive cells were found among large numbers of ir-OTR-negative cells. The PGF2alpha response to OT was insignificant in heifers of all age groups, in contrast to that in cows at estrus. Endometrial cells from 4- to 5-month-old heifers did not respond to OT with PG release in the absence or presence of added arachidonic acid. Tumor promoters, lipopolysaccharide, and interleukin-2 also failed to elicit PG release in vitro, although they induced PG release in similar cell cultures from cyclic cows. In summary, uterine tissues of prepubertal heifers have high levels of OTR, which appear to be developmentally regulated. These receptors are not coupled to PG synthase, or alternatively, the PG synthase gene is not expressed before puberty, possibly because the tissues have had no previous exposure to progesterone.


Assuntos
Bovinos/fisiologia , Ocitocina/farmacologia , Prostaglandinas/biossíntese , Receptores de Ocitocina/metabolismo , Animais , Ligação Competitiva , Dinoprosta/análogos & derivados , Dinoprosta/metabolismo , Endométrio/citologia , Endométrio/efeitos dos fármacos , Endométrio/metabolismo , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/metabolismo , Feminino , Imuno-Histoquímica , Concentração Osmolar , Distribuição Tecidual
19.
Endocrinology ; 127(2): 629-36, 1990 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-2164915

RESUMO

The binding of [3H]oxytocin ([3H]-OT) and [3H]arginine vasopressin ([ 3H]-AVP) by bovine endometrial and myometrial membrane preparations obtained on days 0, 7, 14, 17, and 21 after estrus or mating was investigated. [3H]OT was bound with higher affinity than [3H]AVP by both tissues; the mean dissociation constants (KdS) were 0.95 x 10(-9) M and 1.56 x 10(-9) M for OT and AVP, respectively, P less than 0.0001, with no significant variations in the KdS during the cycle. The concentration of [3H]OT binding sites was on the average 50% higher than [3H]AVP across the cycle in both tissues. Endometrial receptor levels varied significantly during the cycle; it was lowest on days 7 and 14, rose significantly on day 17, and peaked on day 21. Myometrial receptor levels decreased from levels at estrus on days 7 and 14, but the changes were not significant. The ratio between endometrial and myometrial receptor concentrations changed from about 10 at estrus to less than 1 in the luteal phase. In early pregnancy, the receptor levels did not differ from nonpregnant levels on days 7 and 14, but on day 17 the endometrial receptor concentrations were significantly lower, and on day 21 those in both tissues were significantly lower. The endometrial OT and AVP receptor concentrations were inversely correlated with plasma progesterone levels (P = 0.005) with no correlation to plasma estradiol, whereas the myometrial receptor concentrations showed no correlation to plasma progesterone but an inverse correlation with plasma estradiol (P = 0.004). We conclude that the endometrial OT and AVP receptor concentrations are more tightly controlled by progesterone than myometrium, and that the bovine conceptus suppresses endometrial OT and AVP receptor concentrations in the preattachment stage either by a local action on the endometrium or indirectly via an antiluteolytic effect.


Assuntos
Endométrio/metabolismo , Estro/metabolismo , Miométrio/metabolismo , Prenhez/metabolismo , Receptores de Angiotensina/metabolismo , Receptores de Vasopressinas , Animais , Arginina Vasopressina/metabolismo , Bovinos , Estradiol/sangue , Feminino , Cinética , Ocitocina/metabolismo , Gravidez , Progesterona/sangue , Receptores de Ocitocina , Valores de Referência
20.
Free Radic Biol Med ; 20(4): 595-600, 1996.
Artigo em Inglês | MEDLINE | ID: mdl-8904301

RESUMO

This study was designed to focus on the potential stress that xanthine oxidase could produce in copper-deficient rats fed fructose. Fructose consumption results in an excess production of uric acid due to an increased degradation of nucleotides. The enzyme xanthine oxidase catalyzes the oxidation of both hypoxanthine and xanthine. During the oxidation process free radicals are generated, which in turn, induce lipid peroxidation and premature death. Allopurinol -- a competitive inhibitor of xanthine oxidase -- could alleviate the combined effects of fructose feeding and copper deficiency. Twenty-five male rats were fed for 4 weeks from weaning a copper-deficient or adequate diet containing fructose. Twelve rats were given a daily oral dose of 5 mg allopurinol/100 g b.wt. Two copper-deficient rats that were not treated with allopurinol died prematurely during the fourth week of the study. No mortality occurred in the group of copper-deficient rats that had been treated with allopurinol. Anemia was alleviated by allopurinol, which in turn, could be responsible for improved growth rate. Allopurinol was effective in inhibiting xanthine oxidase activity in vivo as measured by the dramatic reduction of uric acid production. Lipid peroxidation, however, was not affected by allopurinol. It is concluded that the beneficial effects of allopurinol in copper deficiency do not appear to be related to prevention of oxygen radicals, but rather, to the protection against the catabolic destruction of purines, which in turn, increases nucleotide pool.


Assuntos
Alopurinol/farmacologia , Cobre/deficiência , Inibidores Enzimáticos/farmacologia , Frutose/farmacologia , Ácido Úrico/metabolismo , Xantina Oxidase/antagonistas & inibidores , Animais , Dieta , Radicais Livres , Coração/efeitos dos fármacos , Peroxidação de Lipídeos/efeitos dos fármacos , Fígado/efeitos dos fármacos , Masculino , Pâncreas/efeitos dos fármacos , Ratos , Ratos Sprague-Dawley
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA