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1.
Plant Biol (Stuttg) ; 21(3): 380-382, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-29869830

RESUMO

The National Seed Strategy for Rehabilitation and Restoration was developed by a partnership of 12 federal agencies and over 300 non-federal cooperators in the United States and launched in 2015. Implementation aims to ensure the availability of genetically appropriate native seed for ecological restoration across the country. Ecological restoration is required in response to a wide range of human impacts. The four main goals of the strategy are: identification of seed needs and availability of genetically appropriate seed; research to improve seed production and ecosystem restoration; development of decision support tools for ecological restoration; and communication and outreach. With the increasing occurrence and intensity of extreme weather events including drought and related wild fires, hurricanes and flooding, native seed is increasingly required in large quantities to build ecological resilience. Acceptance of this need will be crucial to implementation of the National Seed Strategy.


Assuntos
Ecossistema , Sementes , Conservação dos Recursos Naturais , Ecologia , Estados Unidos
2.
Proc Inst Mech Eng H ; 221(4): 351-6, 2007 May.
Artigo em Inglês | MEDLINE | ID: mdl-17605392

RESUMO

Fat pads are masses of encapsulated adipose tissue located throughout the human body. Whilst a number of studies describe these soft tissues anatomically little is known about their biomechanics, and surgeons may excise them arthroscopically if they hinder visual inspection of the joint or bursa. By measuring the coefficient of friction between, and performing Sommerfeld analysis of, the surfaces approximating the in vivo conjuncture, this contact has been shown to have a coefficient of friction of the order of 0.01. The system appears to be lubricated hydrodynamically, thus possibly promoting low levels of wear. It is suggested that one of the functions of fat pads associated with subtendinous bursae and synovial joints is to generate a hydrodynamic lubricating layer between the opposing surfaces.


Assuntos
Tecido Adiposo/fisiologia , Articulação Metacarpofalângica/fisiologia , Modelos Biológicos , Líquido Sinovial/fisiologia , Animais , Bovinos , Fricção , Técnicas In Vitro , Lubrificação , Propriedades de Superfície
3.
Ann Biomed Eng ; 44(10): 3007-3019, 2016 10.
Artigo em Inglês | MEDLINE | ID: mdl-27059224

RESUMO

Nasal high flow (NHF) therapy is used to treat a variety of respiratory disorders to improve patient oxygenation. A CO2 washout mechanism is believed to be responsible for the observed increase in oxygenation. In this study, experimentally validated Computational Fluid Dynamics simulations of the CO2 concentration within the upper airway during unassisted and NHF assisted breathing were undertaken with the aim of exploring the existence of this washout mechanism. An anatomically accurate nasal cavity model was generated from a CT scan and breathing was reproduced using a Fourier decomposition of a physiologically measured breath waveform. Time dependent CO2 profiles were obtained at the entrance of the trachea in the experimental model, and were used as simulation boundary conditions. Flow recirculation features were observed in the anterior portion of the nasal cavity upon application of the therapy. This causes the CO2 rich gas to vent from the nostrils reducing the CO2 concentration in the dead space and lowering the inspired CO2 volume. Increasing therapy flow rate increases the penetration depth within the nasal cavity of the low CO2 concentration gas. A 65% decrease in inspired CO2 was observed for therapy flow rates ranging from 0 to 60 L min(-1) supporting the washout mechanism theory.


Assuntos
Dióxido de Carbono/metabolismo , Oxigenoterapia Hiperbárica , Modelos Biológicos , Cavidade Nasal/metabolismo , Traqueia/metabolismo , Adulto , Humanos , Masculino , Cavidade Nasal/fisiopatologia , Traqueia/fisiopatologia
4.
Biochim Biophys Acta ; 1174(1): 117-21, 1993 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-8334162

RESUMO

The functional properties of preparations of protein synthesis initiation factor eIF-2 which lack the beta-subunit (as confirmed immunologically) were compared with those of the heterotrimeric factor. The former can bind guanine nucleotides but not initiator tRNA, and also exhibits a substantially reduced rate of initiation factor eIF-2B-mediated GDP/GTP-exchange.


Assuntos
Fator de Iniciação 2 em Eucariotos/metabolismo , Guanosina Difosfato/metabolismo , Guanosina Trifosfato/metabolismo , Proteínas/metabolismo , RNA de Transferência de Metionina/metabolismo , Animais , Fator de Iniciação 2 em Eucariotos/química , Fatores de Troca do Nucleotídeo Guanina , Coelhos , Reticulócitos/metabolismo
5.
Curr Top Microbiol Immunol ; 159: 37-63, 1990.
Artigo em Inglês | MEDLINE | ID: mdl-2189692

RESUMO

This chapter identifies three forms of B-cell memory: (a) B blasts which characterize the established stage of the follicular response to TD antigens, (b) recirculating memory B cells, and (c) non-recirculating memory B cells of the marginal zones of the spleen and equivalent areas of other secondary lymphoid organs. The follicular B blasts show sustained proliferation driven by small amounts of antigen bound to FDCs. The probable relationships between these cells is summarized diagrammatically in Fig. 4. It is probable that follicular B blasts generate both the recirculating and marginal zone memory cells. The chapter by Gray and Leanderson in this volume cites data which indicate that the recirculating memory pool is not sustained for more than a few weeks in the absence of antigen. Data leading to the same conclusion for marginal zone memory B cells is set out in Sect. 5.1 of this chapter. Marginal zone memory B cells do not appear to move spontaneously to follicles for periodic renewal. They will only leave the marginal zone if a fresh supply of antigen reaches them in that site. Recirculating B cells are able to respond to antigen already held on FDCs. It is not known if they are able to displace B blasts of equivalent affinity for antigen which already occupy antigen-holding sites on FDCs. This could be a mechanism by which B blasts with high antigen affinity produced in one follicle could displace blasts of lower affinity in other follicles. Little is known of the factors which regulate the numbers of marginal zone and recirculating follicular memory B cells. In responses to hapten-protein conjugates, hapten-binding cells may approach 10% of marginal zone B cells but comprise well under 1% of recirculating follicular cells. The numbers of these memory cells do not increase if the recirculating pool of lymphocytes is depleted, indicating that the factors which regulate the number of memory B cells are independent of those which regulate the total size of the recirculating B-cell pool. A depleted peripheral B-cell pool can only be fully reconstituted by recruitment of newly produced virgin B cells. Data cited in Sect. 5.2 support the concept that this recruitment is at least partially independent of antigen-driven B-cell proliferation. Consequently, substantial proportions of the peripheral B-cell pools are likely to be either virgin cells or cells which have been recruited by antigen or anti-idiotype without entering cell cycle.(ABSTRACT TRUNCATED AT 400 WORDS)


Assuntos
Linfócitos B/imunologia , Animais , Afinidade de Anticorpos , Formação de Anticorpos/imunologia , Antígenos/imunologia , Antígenos T-Independentes/imunologia , Células Clonais/imunologia , Genes de Imunoglobulinas , Humanos , Memória Imunológica/imunologia , Ativação Linfocitária , Linfócitos T/imunologia
6.
Eur Cell Mater ; 9: 23-32; discussion 23-32, 2005 Apr 14.
Artigo em Inglês | MEDLINE | ID: mdl-15830323

RESUMO

Defects of articular cartilage that do not penetrate to the subchondral bone fail to heal spontaneously. Defects that penetrate to the subchondral bone elicit an intrinsic repair response that yields a fibrocartilaginous repair tissue which is a poor substitute for hyaline articular cartilage. Many arthroscopic repair strategies employed utilise this intrinsic repair response to induce the formation of a repair tissue within the defect. The goal, however, is to produce a repair tissue that has the same functional and mechanical properties of hyaline articular cartilage. To this end, autologous osteochondral transfer can provide symptomatic relief. This technique involves the excision of healthy cartilage plugs from 'non-load bearing' regions of the joint for implantation into the defect. Cell based transplantation methods currently involve the transplantation of expanded autologous chondrocytes to the defects to form a repair tissue. This technique again involves the excision of healthy cartilage from the joint for expansion. Current research is exploring the potential use of mesenchymal stem cells as a source for tissue engineering, as well as the combination of cells with biodegradable scaffolds. Although current repair strategies improve joint function, further research is required to prevent future degeneration of repair tissue.


Assuntos
Cartilagem Articular/patologia , Cartilagem Articular/fisiologia , Engenharia Tecidual/métodos , Cicatrização , Animais , Condrócitos/transplante , Transplante Autólogo
7.
Clin Cancer Res ; 4(6): 1451-7, 1998 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-9626462

RESUMO

The purpose of this study is to evaluate whether metastatic breast cancer that has progressed on an anthracycline-containing drug regimen will subsequently respond to that identical regimen if dexverapamil, a modulator of P-glycoprotein-mediated drug resistance, is given concomitantly. Eligible patients received 180 mg/m2 dexverapamil every 6 h for 15 doses with the anthracycline administered 30 min after the seventh dose. Blood for dexverapamil levels was drawn before and 30 min after this dose. When possible, biopsies were obtained to measure mdr-1 expression by reverse transcription-PCR and by image cytometry. Of the 21 patients entered onto the trial, 20 were evaluable for response. There were two partial responses (10%) that both lasted for 6 months, and two additional patients had stable disease. Seven patients had asymptomatic cardiotoxicity consisting of hypotension (24%), bradycardia (5%), or prolongation of the P-R interval (14%). Two patients developed acute congestive heart failure, one on dexverapamil and one 10 days after stopping it. Dexverapamil did not seem to increase anthracycline toxicity. The median trough dexverapamil plus norverapamil level on day 3 was 1110 ng/ml (range, 186-3385 ng/ml), and the median peak level was 2164 ng/ml (range, 964-8382 ng/ml). There was poor correlation between reverse transcription-PCR and image cytometry for the level of mdr-1 expression. Because dexverapamil has been shown to affect doxorubicin pharmacokinetics subsequent to the initiation of this trial, it cannot be concluded that the responses seen were necessarily due to P-glycoprotein inhibition. Additional studies are necessary to determine whether mdr-1 modulators can reverse clinical drug resistance in breast cancer patients. The intrinsic cardiotoxicity of dexverapamil makes it less suitable for such studies than several other available agents.


Assuntos
Membro 1 da Subfamília B de Cassetes de Ligação de ATP/biossíntese , Antibióticos Antineoplásicos/uso terapêutico , Neoplasias da Mama/tratamento farmacológico , Doxorrubicina/uso terapêutico , Epirubicina/uso terapêutico , Verapamil/uso terapêutico , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/efeitos dos fármacos , Adulto , Idoso , Antibióticos Antineoplásicos/efeitos adversos , Neoplasias da Mama/patologia , Progressão da Doença , Doxorrubicina/efeitos adversos , Resistência a Múltiplos Medicamentos , Epirubicina/efeitos adversos , Feminino , Humanos , Pessoa de Meia-Idade , Metástase Neoplásica , Verapamil/efeitos adversos
8.
Br J Pharmacol ; 172(2): 593-605, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24697554

RESUMO

BACKGROUND AND PURPOSE: Naturally occurring single-nucleotide polymorphisms (SNPs) within GPCRs can result in alterations in various pharmacological parameters. Understanding the regulation and function of endocytic trafficking of the µ-opioid receptor (MOP receptor) is of great importance given its implication in the development of opioid tolerance. This study has compared the agonist-dependent trafficking and signalling of L83I, the rat orthologue of a naturally occurring variant of the MOP receptor. EXPERIMENTAL APPROACH: Cell surface elisa, confocal microscopy and immunoprecipitation assays were used to characterize the trafficking properties of the MOP-L83I variant in comparison with the wild-type receptor in HEK 293 cells. Functional assays were used to compare the ability of the L83I variant to signal to several downstream pathways. KEY RESULTS: Morphine-induced internalization of the L83I MOP receptor was markedly increased in comparison with the wild-type receptor. The altered trafficking of this variant was found to be specific to morphine and was both G-protein receptor kinase- and dynamin-dependent. The enhanced internalization of L83I variant in response to morphine was not due to increased phosphorylation of serine 375, arrestin association or an increased ability to signal. CONCLUSIONS AND IMPLICATIONS: These results suggest that morphine promotes a specific conformation of the L83I variant that makes it more liable to internalize in response to morphine, unlike the wild-type receptor that undergoes significantly less morphine-stimulated internalization, providing an example of a ligand-selective biased receptor. The presence of this SNP within an individual may consequently affect the development of tolerance and analgesic responses. LINKED ARTICLES: This article is part of a themed section on Opioids: New Pathways to Functional Selectivity. To view the other articles in this section visit http://dx.doi.org/10.1111/bph.2015.172.issue-2.


Assuntos
Analgésicos Opioides/farmacologia , Morfina/farmacologia , Receptores Opioides mu/metabolismo , Animais , Células HEK293 , Humanos , Mutação , Ratos , Receptores Opioides mu/genética
9.
FEBS Lett ; 327(1): 71-4, 1993 Jul 19.
Artigo em Inglês | MEDLINE | ID: mdl-8335099

RESUMO

In mammalian cells, protein synthesis can be regulated at the level of elongation by the phosphorylation of elongation factor 2 (eEF-2) by a highly specific Ca2+/calmodulin-dependent kinase. In this report, we show that eEF-2 from a cell line derived from the insect, Spodoptera frugiperda, is a substrate for mammalian eEF-2 kinase and that phosphorylation is Ca(2+)-dependent. Furthermore, two-dimensional peptide mapping shows that the kinase phosphorylates the same sites in Spodoptera eEF-2 as those phosphorylated in the rabbit protein. However, we were unable to detect an eEF-2 kinase in Spodoptera cells.


Assuntos
Proteínas Quinases Dependentes de Cálcio-Calmodulina , Fatores de Alongamento de Peptídeos/metabolismo , Sequência de Aminoácidos , Animais , Linhagem Celular , Células Cultivadas , Eletroforese em Gel Bidimensional , Quinase do Fator 2 de Elongação , Dados de Sequência Molecular , Mariposas/enzimologia , Fator 2 de Elongação de Peptídeos , Fatores de Alongamento de Peptídeos/isolamento & purificação , Mapeamento de Peptídeos , Fosfoproteínas/metabolismo , Fosforilação , Proteínas Quinases/metabolismo , Coelhos , Especificidade por Substrato
10.
Clin Chim Acta ; 145(3): 307-11, 1985 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-3987033

RESUMO

The use of free thyroxine assay as the basis for monitoring patients on thyroxine replacement therapy was assessed. Patients with normal free thyroxine levels were divided into sub-groups on the basis of serum TSH levels. Of these, patients with normal TSH levels had higher serum free thyroxine and free 3,5,3'-triiodothyronine concentrations than patients with elevated TSH levels. No significant differences were seen in the level of duration of replacement therapy. Patients were almost equally divided between the high and normal TSH sub-groups. It was concluded that free thyroxine assay had little role to play in the monitoring of these patients.


Assuntos
Hipotireoidismo/tratamento farmacológico , Tireotropina/sangue , Tiroxina/uso terapêutico , Humanos , Hipotireoidismo/sangue , Hipotireoidismo/classificação , Tiroxina/sangue , Tri-Iodotironina/sangue
11.
Prostaglandins Other Lipid Mediat ; 63(4): 165-73, 2001 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-11305694

RESUMO

The intercellular signalling actions of the lipid mediators, the eicosanoids, are transduced by a family of seven transmembrane domain receptors. Members of this receptor family with high affinity for PGE2 are termed EP receptors. There are four known EP receptor genes that are transcribed to generate EP1, EP2, EP3 and EP4 receptors. Two of these receptor transcripts, EP1 and EP3, are further modified by RNA splicing to give multiple receptor isoforms. The EP3 receptor is known to have multiple splice variants in human (9 variants), cow (4 variants), mouse (3 variants) and rat (3 variants). In the rat the three EP3 splice variants differ in the sequence of the intracellular C-terminus. We have identified a fourth splice variant of the rat prostaglandin EP3 receptor that has a greatly truncated intracellular C-terminus when compared to the other EP3 receptor isoforms. Using nested RT-PCR we have shown that this novel splice variant is strongly expressed in rat brain and is also found in spinal cord, kidney and spleen.


Assuntos
Processamento Alternativo , Expressão Gênica , Receptores de Prostaglandina E/genética , Sequência de Aminoácidos , Animais , Sequência de Bases , Encéfalo/metabolismo , Rim/metabolismo , Dados de Sequência Molecular , Especificidade de Órgãos , Ratos , Receptores de Prostaglandina E/química , Receptores de Prostaglandina E Subtipo EP3 , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Alinhamento de Sequência , Transdução de Sinais , Medula Espinal/metabolismo , Baço/metabolismo
12.
Prostaglandins Other Lipid Mediat ; 63(3): 109-22, 2001 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-11204738

RESUMO

Prostaglandins are known to act via seven transmembrane domain receptors to exert actions on both peripheral and central neurons resulting in changes in neuronal excitability. Prostaglandin E2, the prostaglandin most often associated with inflammation, itself acts on a family of closely related receptors, the EP receptors. Using semi-quantitative reverse transcription polymerase chain reaction (RT-PCR), we have shown that rat primary afferent neurons express the mRNA for all EP receptor subtypes, and that some, but not all EP receptor subtype mRNAs are down-regulated in sensory neurons in response to an acute peripheral inflammation. We also show for the first time that all EP receptor subtype mRNAs are expressed in rat lumbar spinal cord. Spinal cord EP receptor subtype mRNAs are also regulated in acute inflammation in a pattern distinct from the changes seen in sensory ganglia in response to the same inflammatory stimulus.


Assuntos
Gânglios Espinais/metabolismo , Inflamação/genética , RNA Mensageiro/genética , Receptores de Prostaglandina E/genética , Medula Espinal/metabolismo , Animais , Sequência de Bases , DNA Complementar , Gânglios Espinais/patologia , Masculino , Dados de Sequência Molecular , RNA Mensageiro/metabolismo , Ratos , Ratos Wistar , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Homologia de Sequência do Ácido Nucleico , Medula Espinal/patologia
13.
Biol Psychol ; 2(3): 227-36, 1975.
Artigo em Inglês | MEDLINE | ID: mdl-1139020

RESUMO

In this study the ischemic nerve block (INB) technique is investigated as a procedure for blocking afferent information in the study of the sensory control of movements. A movement replication task is used. The results suggest that the elbow, wrist and metacarpal-phalangeal joints are at three different stages of sensory information loss or reduction. With the index finger, replications of joint position are not made in the correct direction significantly greater than chance. Error is also largest for the finger. The elbow joint appears to be least affected by the block. Motor impairment under the block is also investigated and the results show that there is a marked decrement in the force exerted in flexion and extension of the index finger, wrist and elbow joints after sensory drop-out. This finding indicates that there is substantial motor impairment of movements distal to the block. The limitations of the INB technique as a procedure for investigating the control of movement under conditions of sensory loss are discussed.


Assuntos
Braço/inervação , Atividade Motora , Bloqueio Nervoso , Projetos de Pesquisa , Sensação , Braço/irrigação sanguínea , Cotovelo/inervação , Cotovelo/fisiologia , Articulação do Cotovelo , Articulações dos Dedos , Dedos/inervação , Dedos/fisiologia , Antebraço/inervação , Humanos , Cinestesia , Masculino , Punho/inervação , Punho/fisiologia , Articulação do Punho
14.
Tissue Cell ; 8(1): 93-9, 1976.
Artigo em Inglês | MEDLINE | ID: mdl-1265738

RESUMO

The form of the globiferous pedicellariae from Psammechinus miliaris is described. The valve ossicle resembles that of Parechinus in its triangular valve shape and open blade form, contrasting with Echinus in these features. The present study indicates that the relationship of the valve nerve pathway to the skeletal ossicle is related to the form of the distal blade. It is proposed that subterminal teeth or a tubular blade may be alternative structural devices for strengthening the venom tooth during venom injection.


Assuntos
Ouriços-do-Mar/ultraestrutura , Animais , Axônios/ultraestrutura , Microscopia Eletrônica de Varredura , Músculos/inervação , Músculos/ultraestrutura , Peçonhas
15.
J Child Health Care ; 5(1): 11-8, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11858425

RESUMO

Coping of parents and children in a children's surgical area, where members had the same or different coping styles, was investigated using self-report and observation. Differences in effectiveness of coping strategies were found between groups of children, mainly in relation to emotion-focused coping. Parent groups were mainly distinguished from each other by the reported effectiveness of their spiritual and distracting strategies. Observational data showed group differences in patterns of parent-child interaction relating to coping behaviours prior to surgery. The findings indicate reciprocal parent-child influences of coping strategies and behaviours.


Assuntos
Adaptação Psicológica , Relações Pais-Filho , Pais/psicologia , Procedimentos Cirúrgicos Operatórios/psicologia , Análise de Variância , Criança , Comportamento Infantil , Feminino , Humanos , Masculino , Inquéritos e Questionários
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