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3.
Curr Med Chem ; 22(1): 51-8, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25139396

RESUMO

Diabetic retinopathy is one of the most common complications of diabetes. A plethora of literature indicates that oxidative stress may play a central role in the pathogenesis of diabetic retinopathy. One could thus hypothesise that antioxidant therapies may be protective for diabetic retinopathy. Anthocyanins are important natural bioactive pigments responsible for red-blue colour of fruits, leaves, seeds, stems and flowers in a variety of plant species. Apart from their colours, anthocyanins are known to be health-promoting phytochemicals with potential properties useful to protect against oxidative stress in some degenerative diseases. They also have a variety of biological properties including anti-inflammatory, antibacterial, anticancer, and cardio-protective properties. Some reports further suggest a therapeutic role of anthocyanins to prevent and/or protect against ocular diseases but more studies are needed to examine their potential as alternative therapy to diabetic retinopathy. The present article reviews the available literature concerning the beneficial role of anthocyanins in diabetic retinopathy.


Assuntos
Antocianinas/uso terapêutico , Retinopatia Diabética/tratamento farmacológico , Antocianinas/química , Antocianinas/farmacologia , Antioxidantes/química , Antioxidantes/farmacologia , Antioxidantes/uso terapêutico , Ensaios Clínicos como Assunto , Retinopatia Diabética/metabolismo , Retinopatia Diabética/patologia , Humanos , Metaloproteinases da Matriz/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Plantas/química , Plantas/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Espécies Reativas de Oxigênio/metabolismo
4.
Cell Death Differ ; 19(12): 2040-8, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22918439

RESUMO

Caspases, cysteine proteases with aspartate specificity, are key players in programmed cell death across the metazoan lineage. Hundreds of apoptotic caspase substrates have been identified in human cells. Some have been extensively characterized, revealing key functional nodes for apoptosis signaling and important drug targets in cancer. But the functional significance of most cuts remains mysterious. We set out to better understand the importance of caspase cleavage specificity in apoptosis by asking which cleavage events are conserved across metazoan model species. Using N-terminal labeling followed by mass spectrometry, we identified 257 caspase cleavage sites in mouse, 130 in Drosophila, and 50 in Caenorhabditis elegans. The large majority of the caspase cut sites identified in mouse proteins were found conserved in human orthologs. However, while many of the same proteins targeted in the more distantly related species were cleaved in human orthologs, the exact sites were often different. Furthermore, similar functional pathways are targeted by caspases in all four species. Our data suggest a model for the evolution of apoptotic caspase specificity that highlights the hierarchical importance of functional pathways over specific proteins, and proteins over their specific cleavage site motifs.


Assuntos
Apoptose , Caspases/metabolismo , Animais , Caenorhabditis elegans/enzimologia , Linhagem Celular , Drosophila/enzimologia , Humanos , Espectrometria de Massas , Camundongos , Transdução de Sinais , Especificidade por Substrato
5.
Stem Cells ; 29(9): 1391-404, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21774040

RESUMO

Retinal degenerative diseases are a major cause of untreatable blindness. Stem cell therapy to replace lost photoreceptors represents a feasible future treatment. We previously demonstrated that postmitotic photoreceptor precursors expressing an NrlGFP transgene integrate into the diseased retina and restore some light sensitivity. As genetic modification of precursor cells derived from stem cell cultures is not desirable for therapy, we have tested cell selection strategies using fluorochrome-conjugated antibodies recognizing cell surface antigens to sort photoreceptor precursors. Microarray analysis of postnatal NrlGFP-expressing precursors identified four candidate genes encoding cell surface antigens (Nt5e, Prom1, Podxl, and Cd24a). To test the feasibility of using donor cells isolated using cell surface markers for retinal therapy, cells selected from developing retinae by fluorescence-activated cell sorting based on Cd24a expression (using CD24 antibody) and/or Nt5e expression (using CD73 antibody) were transplanted into the wild-type or Crb1(rd8/rd8) or Prph2(rd2/rd2) mouse eye. The CD73/CD24-sorted cells migrated into the outer nuclear layer, acquired the morphology of mature photoreceptors and expressed outer segment markers. They showed an 18-fold higher integration efficiency than that of unsorted cells and 2.3-fold higher than cells sorted based on a single genetic marker, NrlGFP, expression. These proof-of-principle studies show that transplantation competent photoreceptor precursor cells can be efficiently isolated from a heterogeneous mix of cells using cell surface antigens without loss of viability for the purpose of retinal stem cell therapy. Refinement of the selection of donorphotoreceptor precursor cells can increase the number of integrated photoreceptor cells,which is a prerequisite for the restoration of sight.


Assuntos
Antígenos de Superfície/biossíntese , Células Fotorreceptoras Retinianas Bastonetes/transplante , Células-Tronco/citologia , Animais , Diferenciação Celular , Perfilação da Expressão Gênica , Imuno-Histoquímica , Camundongos , Camundongos Transgênicos , Retina/citologia , Células Fotorreceptoras Retinianas Bastonetes/citologia , Células Fotorreceptoras Retinianas Bastonetes/imunologia , Células-Tronco/imunologia
6.
Gene Ther ; 18(5): 509-16, 2011 May.
Artigo em Inglês | MEDLINE | ID: mdl-21209626

RESUMO

Multiple myeloma causes approximately 10% of all hematologic malignancies. We have previously shown that human T cells expressing chimeric NKG2D receptors (chNKG2D) consisting of NKG2D fused to the CD3ζ cytoplasmic domain secrete proinflammatory cytokines and kill human myeloma cells. In this study, we show chNKG2D T cells are effective in a murine model of multiple myeloma. Mice with established 5T33MM-green fluorescent protein tumors were treated with one or two infusions of chNKG2D T cells. Compared with mice treated with T cells expressing wild type (wt)NKG2D receptors, a single dose of chNKG2D T cells increased survival, with half of the chNKG2D T-cell-treated mice surviving long term. Two infusions of chNKG2D T cells led to tumor-free survival in all mice. ChNKG2D T cells were located at sites of tumor growth, including the bone marrow and spleen after intravenous injection. There was an increase in activated host T cells and NK cells at tumor sites and in serum interferon-γ after chNKG2D T-cell injection. Surviving mice were able to resist a rechallenge with 5T33MM cells but not RMA lymphoma cells, indicating that the mice developed a protective, specific memory response. These data demonstrate that chNKG2D T cells may be an effective adoptive cellular therapy for multiple myeloma.


Assuntos
Complexo CD3/genética , Imunoterapia Adotiva , Mieloma Múltiplo/terapia , Subfamília K de Receptores Semelhantes a Lectina de Células NK/genética , Linfócitos T/imunologia , Transgenes , Animais , Medula Óssea/imunologia , Modelos Animais de Doenças , Memória Imunológica , Interferon gama/metabolismo , Camundongos , Mieloma Múltiplo/imunologia , Mieloma Múltiplo/mortalidade
7.
Br J Oral Maxillofac Surg ; 49(1): 29-36, 2011 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-20079957

RESUMO

The aim of this paper is to provide a systematic review of articles concerning primary osseointegrated dental implants in the head and neck oncology setting. We searched MEDLINE (1950 to March 2009) and Embase (1980 to March 2009) using the terms head and neck, oral, maxillofacial, craniofacial, jaws, mandible, maxilla, zygoma, dental implants, osseointegrated implants, implants, tumour, cancer, oncology, immediate, simultaneous, and primary. Two authors independently reviewed the abstracts, and all those written in the English language that referred to the placement of primary dental implants in patients with cancer of the head neck were included. Articles that referred to craniofacial or extraoral implants were excluded. Of 892 abstracts 83 were eligible for further consideration; the full articles were evaluated, and 41 that complied fully with the inclusion criteria are presented as a tabulated summary. There are three case reports, 13 reviews, and 25 clinical studies. Eight of the clinical studies refer solely to the insertion of dental implants at the time of primary oncological resection, and only two were of a prospective design. We have concisely summarised publications concerning primary dental implants, and our findings will help to inform head and neck cancer teams, particularly oncological surgeons, restorative dentists, and maxillofacial prosthodontists of the evidence base surrounding this approach to oral rehabilitation.


Assuntos
Implantes Dentários , Neoplasias de Cabeça e Pescoço/cirurgia , Osseointegração/fisiologia , Humanos , Neoplasias Bucais/cirurgia , Qualidade de Vida , Procedimentos de Cirurgia Plástica/métodos , Resultado do Tratamento
8.
Hum Mol Genet ; 19(23): 4545-59, 2010 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-20858907

RESUMO

Retinal degenerative disease causing loss of photoreceptor cells is the leading cause of untreatable blindness in the developed world, with inherited degeneration affecting 1 in 3000 people. Visual acuity deteriorates rapidly once the cone photoreceptors die, as these cells provide daylight and colour vision. Here, in proof-of-principle experiments, we demonstrate the feasibility of cone photoreceptor transplantation into the wild-type and degenerating retina of two genetic models of Leber congenital amaurosis, the Crb1(rd8/rd8) and Gucy2e(-/-) mouse. Crx-expressing cells were flow-sorted from the developing retina of CrxGFP transgenic mice and transplanted into adult recipient retinae; CrxGFP is a marker of cone and rod photoreceptor commitment. Only the embryonic-stage Crx-positive donor cells integrated within the outer nuclear layer of the recipient and differentiated into new cones, whereas postnatal cells generated a 10-fold higher number of rods compared with embryonic-stage donors. New cone photoreceptors displayed unambiguous morphological cone features and expressed mature cone markers. Importantly, we found that the adult environment influences the number of integrating cones and favours rod integration. New cones and rods were observed in ratios similar to that of the host retina (1:35) even when the transplanted population consisted primarily of cone precursors. Cone integration efficiency was highest in the cone-deficient Gucy2e(-/-) retina suggesting that cone depletion creates a more optimal environment for cone transplantation. This is the first comprehensive study demonstrating the feasibility of cone transplantation into the adult retina. We conclude that flow-sorted embryonic-stage Crx-positive donor cells have the potential to replace lost cones, as well as rods, an important requirement for retinal disease therapy.


Assuntos
Transplante de Células/métodos , Amaurose Congênita de Leber/terapia , Células Fotorreceptoras Retinianas Cones/transplante , Células Fotorreceptoras Retinianas Bastonetes/transplante , Animais , Cegueira/terapia , Diferenciação Celular , Modelos Animais de Doenças , Embrião de Mamíferos , Camundongos , Camundongos Transgênicos , Retina/citologia
9.
Cell Transplant ; 19(4): 487-503, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20089206

RESUMO

Diseases culminating in photoreceptor loss are a major cause of untreatable blindness. Transplantation of rod photoreceptors is feasible, provided donor cells are at an appropriate stage of development when transplanted. Nevertheless, the proportion of cells that integrate into the recipient outer nuclear layer (ONL) is low. The outer limiting membrane (OLM), formed by adherens junctions between Müller glia and photoreceptors, may impede transplanted cells from migrating into the recipient ONL. Adaptor proteins such as Crumbs homologue 1 (Crb1) and zona occludins (ZO-1) are essential for localization of the OLM adherens junctions. We investigated whether targeted disruption of these proteins enhances donor cell integration. Transplantation of rod precursors in wild-type mice achieved 949 +/- 141 integrated cells. By contrast, integration is significantly higher when rod precursors are transplanted into Crb1(rd8/rd8) mice, a model of retinitis pigmentosa and Lebers congenital amaurosis that lacks functional CRB1 protein and displays disruption of the OLM (7,819 +/- 1,297; maximum 15,721 cells). We next used small interfering (si)RNA to transiently reduce the expression of ZO-1 and generate a reversible disruption of the OLM. ZO-1 knockdown resulted in similar, significantly improved, integration of transplanted cells in wild-type mice (7,037 +/- 1,293; maximum 11,965 cells). Finally, as the OLM remains largely intact in many retinal disorders, we tested whether transient ZO-1 knockdown increased integration in a model of retinitis pigmentosa, the rho(-/-) mouse; donor cell integration was significantly increased from 313 +/- 58 cells without treatment to 919 +/- 198 cells after ZO-1 knockdown. This study shows that targeted disruption of OLM junctional proteins enhances integration in the wild-type and degenerating retina and may be a useful approach for developing photoreceptor transplantation strategies.


Assuntos
Proteínas de Membrana/antagonistas & inibidores , Proteínas do Tecido Nervoso/genética , Fosfoproteínas/antagonistas & inibidores , Células Fotorreceptoras Retinianas Bastonetes/transplante , Retinose Pigmentar/terapia , Transplante de Células-Tronco , Animais , Movimento Celular , Proteínas de Membrana/genética , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Fosfoproteínas/genética , Interferência de RNA , RNA Interferente Pequeno/metabolismo , Retinose Pigmentar/metabolismo , Proteína da Zônula de Oclusão-1 , Quinases Associadas a rho/deficiência , Quinases Associadas a rho/genética , Quinases Associadas a rho/metabolismo
10.
Br J Oral Maxillofac Surg ; 47(8): 598-601, 2009 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19748711

RESUMO

The aims of this survey of consultants in the British Association of Oral and Maxillofacial Surgeons were threefold. Firstly, to estimate the number of patients screened for oral health before starting intravenous bisphosphonate medication, secondly, to indicate the use of antibiotics in patients on bisphosphonates who need routine extraction of a lower first molar tooth, and finally to estimate the number of new and currently managed cases of bisphosphonate-induced osteonecrosis of the jaw (BONJ) in the last year, and approximately how many of those currently being managed had healed. A questionnaire was mailed to 322 consultants working at 154 hospitals in the summer of 2008. There were responses from 184 consultants (57%) and from 111 hospitals (72%). Screening patients before starting intravenous bisphosphonates was uncommon (15%). Almost all consultants would prescribe antibiotics for molar extraction and in about two-thirds this was both before and after extraction. Relatively few would stop bisphosphonates. Nearly two-thirds of consultants had seen new cases of BONJ from intravenous treatment in the last year, and a quarter had seen three or more. A similar proportion had patients on intravenous bisphosphonates under review for BONJ, and it was estimated that in a fifth of patients the lesion had healed. This survey indicates current practice among oral and maxillofacial surgeons in the UK. A national project for the registration of new patients will provide a stronger evidence base with respect to incidence, risk factors, and management of BONJ.


Assuntos
Atitude do Pessoal de Saúde , Conservadores da Densidade Óssea/efeitos adversos , Difosfonatos/efeitos adversos , Doenças Maxilomandibulares/induzido quimicamente , Osteonecrose/induzido quimicamente , Cirurgia Bucal , Administração Oral , Anti-Infecciosos Locais/administração & dosagem , Anti-Infecciosos Locais/uso terapêutico , Antibioticoprofilaxia , Conservadores da Densidade Óssea/administração & dosagem , Clorexidina/administração & dosagem , Clorexidina/uso terapêutico , Unidade Hospitalar de Odontologia , Difosfonatos/administração & dosagem , Humanos , Injeções Intravenosas , Doenças Maxilomandibulares/psicologia , Doenças Maxilomandibulares/terapia , Programas de Rastreamento , Dente Molar/cirurgia , Osteonecrose/psicologia , Osteonecrose/terapia , Padrões de Prática Odontológica , Sociedades Odontológicas , Inquéritos e Questionários , Fatores de Tempo , Extração Dentária , Alvéolo Dental/fisiologia , Reino Unido , Cicatrização/fisiologia
11.
J Neural Eng ; 6(3): 034001, 2009 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-19367001

RESUMO

The purpose of this communication is to investigate (1) the feasibility of carrying out longitudinal magnetic resonance imaging (MRI) studies in animals with implanted microwire electrodes adapted for MRI compatibility, (2) the effect of MRI studies on the quality of neurophysiological recordings, (3) the use of MRI to study the extent and recovery of tissue damage due to electrode insertion and (4) histological tissue damage due to MRI. There was no evidence of chronic neural damage caused by repeated MRI by any of the measures used nor any statistical difference in the quality of the electrophysiological recordings between animals that had undergone MRI scans and those that had not.


Assuntos
Lesões Encefálicas/etiologia , Córtex Cerebral/efeitos da radiação , Córtex Cerebral/cirurgia , Eletrodos Implantados/efeitos adversos , Imageamento por Ressonância Magnética/efeitos adversos , Lesões por Radiação/etiologia , Lesões Encefálicas/patologia , Córtex Cerebral/patologia , Segurança de Equipamentos , Estudos de Viabilidade , Humanos , Modelos Animais , Lesões por Radiação/patologia
12.
Br J Oral Maxillofac Surg ; 47(4): 310-2, 2009 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-19243868

RESUMO

We report a case of skull base osteomyelitis that presented 4-8 weeks after a level 2 maxillectomy for a plexiform ameloblastoma of the right posterior maxilla. This is an extremely rare complication, and we know of no previously reported cases that developed after maxillectomy. We summarise the presentation, differential diagnosis and management.


Assuntos
Ameloblastoma/complicações , Neoplasias Maxilares/complicações , Osteomielite/etiologia , Ameloblastoma/diagnóstico por imagem , Ameloblastoma/cirurgia , Ciprofloxacina/uso terapêutico , Tuba Auditiva/fisiopatologia , Humanos , Imageamento por Ressonância Magnética , Masculino , Neoplasias Maxilares/diagnóstico por imagem , Neoplasias Maxilares/cirurgia , Pessoa de Meia-Idade , Osteomielite/diagnóstico , Osteomielite/tratamento farmacológico , Base do Crânio/diagnóstico por imagem , Tomografia Computadorizada por Raios X/efeitos adversos , Resultado do Tratamento
13.
An Med Interna ; 25(2): 81-4, 2008 Feb.
Artigo em Espanhol | MEDLINE | ID: mdl-18432365

RESUMO

Hemoperitoneum due to spontaneous rupture of hepatocellular carcinoma (HCC) constitutes a life-threatening situation if no appropriate therapy is provided. This complication is a well-known form of HCC presentation in countries with high incidence of liver tumours, but is an unusual event in Western countries, where it has been described in 5% or less of cases with HCC. We report three patients admitted to our centre with acute hemoperitoneum secondary to non-traumatic rupture as a first manifestation of not previously diagnosed HCC. A review of the related literature is also performed.


Assuntos
Carcinoma Hepatocelular/complicações , Hemoperitônio/etiologia , Neoplasias Hepáticas/complicações , Idoso , Idoso de 80 Anos ou mais , Humanos , Masculino , Ruptura Espontânea
14.
Cytotherapy ; 10(1): 30-7, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-18202972

RESUMO

BACKGROUND: We have previously demonstrated a laboratory model for expanding autologous mononuclear cells into populations of effector killer cells. The goal of the current experiments was to develop a good manufacturing practice (GMP) method for expanding clinical-grade activated effector cells that mediate tumor cell killing through various mechanisms that could be infused into patients following high-dose chemotherapy and autologous stem cell transplant. METHODS: Mobilized mononuclear cells (MNC) from myeloma patients were placed in culture with serum-free AIM V media, interleukin-2 (1000 IU/mL) and OKT-3 (500 ng/mL) at 37 degrees C and 5% CO2. After 7 days of expansion, the cells were analyzed for cell concentration, viability, phenotype and cytotoxicity directed against human myeloma cell lines. Expansion was compared using culture bags and flasks. Cryopreserved expanded cells were also analyzed. RESULTS: This clinical model of ex vivo expansion yielded polyclonal populations of cytotoxic lymphocytes, including CD3+ CD4+ T cells, CD3+ CD8+ T cells, CD8+ CD56+ T cells and CD56+ natural killer cells. Compared with flasks, culture bags provided a 2-3-fold effector cell expansion with minimal risk of contamination. The optimal cell concentration at the time of expansion was 2.5-3.5 x 10(6) peripheral blood MNC/mL. Viability and cytotoxicity were maintained if the expanded cells were cryopreserved and then thawed for use. DISCUSSION: The results demonstrate a reproducible and reliable GMP procedure that is currently being employed in a clinical trial. These expanded cells, and their various pathways of tumor cell killing, may circumvent tumor escape mechanisms and improve outcomes.


Assuntos
Imunoterapia Adotiva/métodos , Células Matadoras Naturais/citologia , Leucócitos Mononucleares/citologia , Linfócitos T CD8-Positivos/citologia , Linfócitos T CD8-Positivos/imunologia , Técnicas de Cultura de Células , Linhagem Celular Tumoral , Células Cultivadas , Criopreservação , Citotoxicidade Imunológica/imunologia , Citometria de Fluxo , Granulócitos/citologia , Granulócitos/imunologia , Humanos , Imunofenotipagem , Células K562 , Células Matadoras Naturais/imunologia , Leucaférese , Leucócitos Mononucleares/imunologia , Receptores de Lipopolissacarídeos/imunologia , Monócitos/citologia , Monócitos/imunologia , Mieloma Múltiplo/sangue , Mieloma Múltiplo/imunologia , Linfócitos T Citotóxicos/citologia , Linfócitos T Citotóxicos/imunologia
15.
J Neurochem ; 101(1): 120-31, 2007 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-17394462

RESUMO

The mitochondrial transporter, the aspartate/glutamate carrier (AGC), is a necessary component of the malate/aspartate cycle, which promotes the transfer into mitochondria of reducing equivalents generated in the cytosol during glycolysis. Without transfer of cytosolic reducing equivalents into mitochondria, neither glucose nor lactate can be completely oxidized. In the present study, immunohistochemistry was used to demonstrate the absence of AGC from retinal glia (Müller cells), but its presence in neurons and photoreceptor cells. To determine the influence of the absence of AGC on sources of ATP for glutamate neurotransmission, neurotransmission was estimated in both light- and dark-adapted retinas by measuring flux through the glutamate/glutamine cycle and the effect of light on ATP-generating reactions. Neurotransmission was 80% faster in the dark as expected, because photoreceptors become depolarized in the dark and this depolarization induces release of excitatory glutamate neurotransmitter. Oxidation of [U-14C]glucose, [1-14C]lactate, and [1-14C]pyruvate in light- and dark-adapted excised retinas was estimated by collecting 14CO2. Neither glucose nor lactate oxidation that require participation of the malate/aspartate shuttle increased in the dark, but pyruvate oxidation that does not require the malate/aspartate shuttle increased to 36% in the dark. Aerobic glycolysis was estimated by measuring the rate of lactate appearance. Glycolysis was 37% faster in the dark. It appears that in the retina, ATP consumed during glutamatergic neurotransmission is replenished by ATP generated glycolytically within the retinal Müller cells and that oxidation of glucose within the Müller cells does not occur or occurs only slowly.


Assuntos
Ácido Glutâmico/metabolismo , Glicólise/fisiologia , Neuroglia/metabolismo , Neurônios/metabolismo , Retina/metabolismo , Transmissão Sináptica/fisiologia , Trifosfato de Adenosina/biossíntese , Sistemas de Transporte de Aminoácidos Acídicos/metabolismo , Animais , Antiporters/metabolismo , Metabolismo Energético/fisiologia , Glucose/metabolismo , Glutamina/metabolismo , Malatos/metabolismo , Masculino , Redes e Vias Metabólicas/fisiologia , Técnicas de Cultura de Órgãos , Células Fotorreceptoras/metabolismo , Ratos , Ratos Sprague-Dawley , Retina/citologia , Visão Ocular/fisiologia , Visão Ocular/efeitos da radiação
16.
Regul Pept ; 129(1-3): 147-54, 2005 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-15927710

RESUMO

Previous studies have shown immunostaining of adrenomedullin (AM) and proadrenomedullin N-terminal 20 peptide (PAMP) throughout the gastrointestinal tract. Based on these data, we decided to investigate the effect of these peptides on intestinal sugar absorption using everted rings from Wistar rat intestine. PAMP increases alpha-methylglucoside (MG) uptake at concentrations ranging from 10(-12) to 10(-7) M. AM shows a dual effect inhibiting sugar absorption at low concentrations (10(-12) to 10(-11) M) and increasing MG uptake at higher concentrations (10(-8) to 10(-6) M). In all cases, the effect is phloridzin-sensitive, indicating that the peptides alter SGLT1 function without modifying the non-mediated component of absorption. The enhancing effect of 10(-8) M AM and PAMP seems to be mediated by elevation of cAMP and is accompanied by an increase on SGLT1 expression in the brush-border membrane of the enterocytes. The inhibitory effect of 10(-12) M AM could be mediated by either cAMP reduction or, more probably, by other second messenger able to inhibit sugar absorption. PKC is not involved in the action of either AM or PAMP. These results demonstrate that both peptides play a role in the regulation of the active transport of sugars in the intestine.


Assuntos
Jejuno/metabolismo , Glicoproteínas de Membrana/metabolismo , Metilglucosídeos/metabolismo , Proteínas de Transporte de Monossacarídeos/metabolismo , Peptídeos/farmacologia , Adrenomedulina , Animais , Transporte Biológico/efeitos dos fármacos , Masculino , Técnicas de Cultura de Órgãos , Ratos , Ratos Sprague-Dawley , Transportador 1 de Glucose-Sódio
17.
Sci Total Environ ; 334-335: 417-26, 2004 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-15504527

RESUMO

The experience of using a telemedicine feasibility study to integrate respiratory health response and environmental stimuli information is presented. The effects of ambient air quality, pollen and local environment conditions on asthmatic patients' lung function were investigated through the use of a novel European health telematic system. The Medical Diagnosis, Communication and Analysis Throughout Europe (MEDICATE) project developed and tested the feasibility of using a telemedicine system for chronic asthmatics in London, UK, and Barcelona, Spain. The key to this was the determination of the real time health (lung function) response to the ambient environment and allergens. Air quality, pollen and environmental lifestyle information were related to respiratory measurements for recruited asthmatic patients in the study through the design of a dedicated environmental management system (EMS) database. In total, 28 patients completed the study trial, subject to ambulatory monitoring of spirometric lung function (PEF, FEV(1) and FVC) up to four times a day over a 2-week period recorded during the year 2000. Alongside this, ambient air quality and pollen counts were used to represent local exposure to potential environmental stimuli. Personal questionnaire interviewing collected additional data about patient lifestyles, social-economic conditions and quality of life perceptions. The methods and indicative results of integrating environmental and health data in this respect are examined. Assessment tools such as GIS and object-orientated databases were designed to locate and compile environmental information about the patients' locations and lifestyles in the study areas (London and Barcelona). Socioeconomic and lifestyle factors, such as exposure to smoking, pets, personal journey lengths and modes, income, household occupancy and domestic fuel use, were found to have limited detectable effects on the patients' basic lung function levels. Patients' gender, age and predicted PEFR were significantly associated with the 2-week mean and minimum respiratory measurements. Lung function data were compared with air quality and pollen indicators to examine relationships on a daily or lagged-day basis controlling for confounding factors. The paper discusses the new methodology and the practicalities of using the telemedical system as a tool for assessing the impacts of environmental stimuli on respiratory health.


Assuntos
Poluentes Atmosféricos/intoxicação , Alérgenos/efeitos adversos , Asma/etiologia , Coleta de Dados , Sistemas de Informação Geográfica , Telemedicina , Adolescente , Adulto , Idoso , Asma/patologia , Criança , Pré-Escolar , Bases de Dados Factuais , Europa (Continente) , Feminino , Humanos , Lactente , Recém-Nascido , Estilo de Vida , Masculino , Pessoa de Meia-Idade , Pólen , Testes de Função Respiratória , Classe Social
18.
JPEN J Parenter Enteral Nutr ; 28(2): 65-75, 2004.
Artigo em Inglês | MEDLINE | ID: mdl-15080599

RESUMO

BACKGROUND: Combining the amino acids arginine and glutamine with the leucine metabolite beta-hydroxy-beta-methylbutyrate (HMB) has been shown to reverse lean tissue loss in cancer and acquired immunodeficiency syndrome (AIDS) patients. Although each of these nutrients has been shown to be safe, the safety of this mixture has not been reported. Three double-blind studies examined the safety of the combination of HMB, arginine and glutamine on blood chemistries, hematology, emotional profile, and adverse events. METHODS: Study 1 was conducted in healthy adult males (n = 34), study 2 was in HIV patients with AIDS-associated weight loss (n = 43), and study 3 was in cancer patients with wasting (n = 32). Volunteers were assigned to either a placebo or a mixture of 3 g HMB, 14 g arginine, and 14 g glutamine per day. RESULTS: Across the 3 studies, HMB, arginine, and glutamine supplementation was not associated with any adverse indicators of health. The only significant changes noted were positive indicators of health status. HMB, arginine, and glutamine supplementation was associated with an improvement in emotional profile (p = .05), a decreased feeling of weakness (p = .03), and increased red blood cells, hemoglobin, hematocrit, lymphocytes, and eosinophils (p < .05) when compared with placebo-supplemented subjects. Blood creatinine levels were not changed. However, blood urea nitrogen increased (p = .01) with HMB, arginine, and glutamine supplementation, which was possibly caused by the additional nitrogen consumed or to the fact that ureagenesis is influenced by arginine and glutamine supplementation. CONCLUSION: These results show that HMB, arginine, and glutamine can be safely used to treat muscle wasting associated with AIDS and cancer.


Assuntos
Ácido 3-Hidroxibutírico/uso terapêutico , Arginina/uso terapêutico , Caquexia/tratamento farmacológico , Suplementos Nutricionais , Glutamina/uso terapêutico , Síndrome de Emaciação por Infecção pelo HIV/tratamento farmacológico , Neoplasias/tratamento farmacológico , Ácido 3-Hidroxibutírico/administração & dosagem , Ácido 3-Hidroxibutírico/efeitos adversos , Arginina/administração & dosagem , Arginina/efeitos adversos , Análise Química do Sangue , Nitrogênio da Ureia Sanguínea , Quimioterapia Combinada , Feminino , Glutamina/administração & dosagem , Glutamina/efeitos adversos , Humanos , Masculino , Neoplasias/complicações , Ensaios Clínicos Controlados Aleatórios como Assunto , Segurança
19.
J Membr Biol ; 195(1): 27-32, 2003 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-14502423

RESUMO

ASCT1 is a member of the glutamate transporter superfamily cloned from human brain and characterized as a Na(+)-dependent neutral amino-acid exchanger, which displays substrate-induced chloride-channel activity and mediates concentrative transport of alanine. Initial studies in ASCT1-expressing Xenopus laevis oocytes showed that proline did not elicit measurable currents, in contrast to what occurred with alanine, serine or cysteine, suggesting that proline was not an ASCT1 substrate, although it induced the release of alanine from preloaded oocytes. Here, we have studied the uptake of proline and hydroxyproline by ASCT1-expressing oocytes in order to investigate the ability of ASCT1 to translocate these imino acids. The results demonstrate ASCT1-mediated proline transport that is Na(+)-dependent, saturable, inhibited by the reported ASCT1 substrates as well as by hydroxyproline and can drive the imino acid against its concentration gradient. The apparent kinetic constants for the transport of alanine and the imino acids, obtained with oocytes from the same batch, showed maximal transport rate for proline and hydroxyproline to be half of that for alanine. However, K(0.5) for proline was 704 +/- 86 microM, about three times higher than alanine K(0.5) (203.3 +/- 36.4 microM), whereas hydroxyproline K(0.5) was 33.2 +/- 4.3 microM, indicating that the hydroxylation on carbon 4 of proline strongly increases the affinity of ASCT1 for this proline derivative. In summary, the present work demonstrates for the first time the ability of ASCT1 to transport proline and hydroxyproline.


Assuntos
Sistema ASC de Transporte de Aminoácidos/metabolismo , Sistemas de Transporte de Aminoácidos Neutros/metabolismo , Oócitos/metabolismo , Prolina/metabolismo , Transporte Proteico/fisiologia , Adaptação Biológica/fisiologia , Animais , Humanos , Hidroxiprolina/metabolismo , Proteínas Recombinantes/metabolismo , Xenopus laevis
20.
J R Soc Med ; 96(2): 60-5, 2003 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-12562974

RESUMO

Homeopathic arnica is widely believed to control bruising, reduce swelling and promote recovery after local trauma; many patients therefore take it perioperatively. To determine whether this treatment has any effect, we conducted a double-blind, placebo-controlled, randomized trial with three parallel arms. 64 adults undergoing elective surgery for carpal tunnel syndrome were randomized to take three tablets daily of homeopathic arnica 30C or 6C or placebo for seven days before surgery and fourteen days after surgery. Primary outcome measures were pain (short form McGill Pain Questionnaire) and bruising (colour separation analysis) at four days after surgery. Secondary outcome measures were swelling (wrist circumference) and use of analgesic medication (patient diary). 62 patients could be included in the intention-to-treat analysis. There were no group differences on the primary outcome measures of pain (P=0.79) and bruising (P=0.45) at day four. Swelling and use of analgesic medication also did not differ between arnica and placebo groups. Adverse events were reported by 2 patients in the arnica 6C group, 3 in the placebo group and 4 in the arnica 30C group. The results of this trial do not suggest that homeopathic arnica has an advantage over placebo in reducing postoperative pain, bruising and swelling in patients undergoing elective hand surgery.


Assuntos
Arnica , Síndrome do Túnel Carpal/cirurgia , Contusões/prevenção & controle , Dor Pós-Operatória/prevenção & controle , Fitoterapia/métodos , Adolescente , Adulto , Idoso , Método Duplo-Cego , Feminino , Mãos/cirurgia , Homeopatia , Humanos , Masculino , Pessoa de Meia-Idade , Resultado do Tratamento
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