RESUMO
INTRODUCTION: Transport of glucose from maternal blood across the placental trophoblastic tissue barrier is critical to sustain fetal growth. The mechanism by which GLUTs are regulated in trophoblasts in response to ischemic hypoxia encountered with intrauterine growth restriction (IUGR) has not been suitably investigated. OBJECTIVE: To investigate placental expression of GLUT1, GLUT3 and GLUT4 and possible mechanisms of GLUT regulation in idiopathic IUGR. METHODS: We analyzed clinical, biochemical and histological data from placentas collected from women affected by idiopathic full-term IUGR (n = 10) and gestational age-matched healthy controls (n = 10). RESULTS: We found increased GLUT3 protein expression in the trophoblast (cytotrophoblast greater than syncytiotrophoblast) on the maternal aspect of the placenta in IUGR compared to normal placenta, but no differences in GLUT1 or GLUT4 were found. No differential methylation of the GLUT3 promoter between normal and IUGR placentas was observed. Increased GLUT3 expression was associated with an increased nuclear concentration of HIF-1α, suggesting hypoxia may play a role in the up-regulation of GLUT3. DISCUSSION: Further studies are needed to elucidate whether increased GLUT3 expression in IUGR is a marker for defective villous maturation or an adaptive response of the trophoblast in response to chronic hypoxia. CONCLUSIONS: Patients with IUGR have increased trophoblast expression of GLUT3, as found under the low-oxygen conditions of the first trimester.
Assuntos
Retardo do Crescimento Fetal/metabolismo , Transportador de Glucose Tipo 3/biossíntese , Placenta/metabolismo , Regulação para Cima , Adulto , Hipóxia Celular , Núcleo Celular/metabolismo , Núcleo Celular/patologia , Feminino , Retardo do Crescimento Fetal/patologia , Transportador de Glucose Tipo 1/genética , Transportador de Glucose Tipo 1/metabolismo , Transportador de Glucose Tipo 3/genética , Transportador de Glucose Tipo 3/metabolismo , Transportador de Glucose Tipo 4/genética , Transportador de Glucose Tipo 4/metabolismo , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Placenta/irrigação sanguínea , Placenta/patologia , Placentação , Pré-Eclâmpsia/metabolismo , Pré-Eclâmpsia/patologia , Gravidez , Transporte Proteico , RNA Mensageiro/metabolismo , Nascimento a Termo , Trofoblastos/metabolismo , Trofoblastos/patologia , Adulto JovemRESUMO
Tumour-induced hypercalcemia (TIH) and pain from bone metastases are common complications of advanced malignancy and have a significant negative impact on quality of life. Many cancer patients in the advanced stages of their palliative illness prefer to avoid hospitalization and to receive their care in the community setting. This small open-label prospective pilot study explored the feasibility of administering zoledronic acid intravenously in the community setting (home and residential hospices). It enrolled a convenience sample of 12 patients with advanced cancer and TIH (n = 7), malignant bone pain (n = 3), or TIH and malignant bone pain (n = 2). The mean duration of infusion was 15 minutes (range: 14-30 minutes). The total nursing time required was 95 minutes, and the mean total cost, including nursing time, travel time, and drug costs was $708.97 per infusion. This cost was compared with costs for clodronate and pamidronate ($402.52 and $406.12 respectively). Calcium fell from a mean of 2.97 mmol/L on day 0 to 2.63 mmol/L on day 4 and to 2.54 mmol/L on day 10. Delirium resolved in 2 of 5 patients with TIH-associated delirium. Intravenous zoledronic acid administered in the community to palliative patients at the end of life is feasible and safe, and the short duration of infusion offers advantages to patients and nursing resources alike. The higher cost of zoledronic acid per infusion may be offset by the advantage of its short infusion time.
RESUMO
The combined and separate effects of exercise training and bisphosphonate (etidronate) therapy on bone mineral in postmenopausal women were compared. Forty-eight postmenopausal women were randomly assigned (double blind) to groups that took intermittent cyclical etidronate; performed strength training (3 d/week) and received matched placebo; combined strength training with etidronate; or took placebo and served as nonexercising controls. Bone mineral, lean tissue, and fat mass were assessed by dual-energy X-ray absorptiometry before and after 12 months of intervention. After removal of outlier results, changes in bone mineral density (BMD) of the lumbar spine and bone mineral content (BMC) of the whole body were greater in the subjects given etidronate (+2.5 and +1.4%, respectively) compared with placebo (-0.32 and 0%, respectively) (p < 0.05), while exercise had no effect. There was no effect of etidronate or exercise on the proximal femur and there was no interaction between exercise and etidronate at any bone site. Exercise training resulted in significantly greater increases in muscular strength and lean tissue mass and greater loss of fat mass compared with controls. We conclude that etidronate significantly increases lumbar spine BMD and whole-body BMC and that strength training has no additional effect. Strength training favourably affects body composition and muscular strength, which may be important for prevention of falls.
Assuntos
Composição Corporal/efeitos dos fármacos , Densidade Óssea/efeitos dos fármacos , Ácido Etidrônico/uso terapêutico , Exercício Físico , Pós-Menopausa , Ingestão de Energia/efeitos dos fármacos , Feminino , Humanos , Pessoa de Meia-IdadeRESUMO
Rift Valley fever virus (RVFV), a phlebovirus of the family Bunyaviridae, is a major public health threat in Egypt and sub-Saharan Africa. The viral and host cellular factors that contribute to RVFV virulence and pathogenicity are still poorly understood. All pathogenic RVFV strains direct the synthesis of a nonstructural phosphoprotein (NSs) that is encoded by the smallest (S) segment of the tripartite genome and has an undefined accessory function. In this report, we show that MP12 and clone 13, two attenuated RVFV strains with mutations in the NSs gene, were highly virulent in IFNAR(-/-) mice lacking the alpha/beta interferon (IFN-alpha/beta) receptor but remained attenuated in IFN-gamma receptor-deficient mice. Both attenuated strains proved to be excellent inducers of early IFN-alpha/beta production. In contrast, the virulent strain ZH548 failed to induce detectable amounts of IFN-alpha/beta and replicated extensively in both IFN-competent and IFN-deficient mice. Clone 13 has a defective NSs gene with a large in-frame deletion. This defect in the NSs gene results in expression of a truncated protein which is rapidly degraded. To investigate whether the presence of the wild-type NSs gene correlated with inhibition of IFN-alpha/beta production, we infected susceptible IFNAR(-/-) mice with S gene reassortant viruses. When the S segment of ZH548 was replaced by that of clone 13, the resulting reassortants became strong IFN inducers. When the defective S segment of clone 13 was exchanged with the wild-type S segment of ZH548, the reassortant virus lost the capacity to stimulate IFN-alpha/beta production. These results demonstrate that the ability of RVFV to inhibit IFN-alpha/beta production correlates with viral virulence and suggest that the accessory protein NSs is an IFN antagonist.
Assuntos
Interferon-alfa/antagonistas & inibidores , Interferon beta/antagonistas & inibidores , Vírus da Febre do Vale do Rift/patogenicidade , Proteínas não Estruturais Virais/fisiologia , Animais , Interferon-alfa/fisiologia , Interferon beta/fisiologia , Camundongos , Camundongos Endogâmicos , Receptores de Interferon/fisiologia , Vírus da Febre do Vale do Rift/crescimento & desenvolvimento , VirulênciaRESUMO
Nanocrystalline gamma-Fe2O3 particles were produced in a microwave flow reactor. The reaction of iron pentacarbonyl [Fe(CO)5] with the plasma gases Ar/O2 to form nanosized particles was followed by in situ particle mass spectrometry. The particle mass spectrometer combines a nonintrusive sampling technique with a calibration-free mass determination. The influence of process parameters like microwave power, precursor concentration, and pressure on the particle size was studied. The results reveal a mean particle diameter in the range of 4-5 nm with a slight dependence on the process parameter. The geometric standard deviation of the measured size distribution was always between 1.1 and 1.2.
Assuntos
Cristalização/métodos , Compostos Férricos/química , Compostos Férricos/efeitos da radiação , Micro-Ondas , Nanotecnologia/métodos , Transferência de Energia , Compostos Férricos/isolamento & purificação , Gases/química , Temperatura Alta , Espectrometria de Massas , Microscopia Eletrônica , Microesferas , Conformação Molecular , Tamanho da Partícula , Reologia/métodosRESUMO
The major histocompatibility complex (MHC) class II transactivator CIITA plays a pivotal role in the control of the cellular immune response through the quantitative regulation of MHC class II expression. We have analyzed a region of CIITA with similarity to leucine-rich repeats (LRRs). CIITA LRR alanine mutations abolish both the transactivation capacity of full-length CIITA and the dominant-negative phenotype of CIITA mutants with N-terminal deletions. We demonstrate direct interaction of CIITA with the MHC class II promoter binding protein RFX5 and could also detect novel interactions with RFXANK, NF-YB, and -YC. However, none of these interactions is influenced by CIITA LRR mutagenesis. On the other hand, chromatin immunoprecipitation shows that in vivo binding of CIITA to the MHC class II promoter is dependent on LRR integrity. LRR mutations lead to an impaired nuclear localization of CIITA, indicating that a major function of the CIITA LRRs is in nucleocytoplasmic translocation. There is, however, evidence that the CIITA LRRs are also involved more directly in MHC class II gene transactivation. CIITA interacts with a novel protein of 33 kDa in a manner sensitive to LRR mutagenesis. CIITA is therefore imported into the nucleus by an LRR-dependent mechanism, where it activates transcription through multiple protein-protein interactions with the MHC class II promoter binding complex.
Assuntos
Estruturas Citoplasmáticas/metabolismo , Genes MHC da Classe II/genética , Antígenos de Histocompatibilidade Classe II/metabolismo , Leucina/metabolismo , Sinais de Localização Nuclear , Proteínas Nucleares , Transativadores/metabolismo , Ativação Transcricional , Transporte Ativo do Núcleo Celular , Sequência de Aminoácidos , Extratos Celulares , Núcleo Celular/metabolismo , Cromatina/genética , Cromatina/metabolismo , Estruturas Citoplasmáticas/genética , Proteínas de Ligação a DNA/metabolismo , Elementos Facilitadores Genéticos/genética , Humanos , Leucina/genética , Modelos Biológicos , Dados de Sequência Molecular , Mutação/genética , Fenótipo , Testes de Precipitina , Regiões Promotoras Genéticas , Ligação Proteica , Fatores de Transcrição de Fator Regulador X , Sequências Repetitivas de Aminoácidos , Alinhamento de Sequência , Transativadores/química , Transativadores/genética , Células Tumorais CultivadasRESUMO
MxA is a large, interferon-induced GTPase with antiviral activity against RNA viruses. It forms large oligomers, but whether oligomerization and GTPase activity are important for antiviral function is not known. The mutant protein MxA(L612K) carries a lysine-for-leucine substitution at position 612 and fails to form oligomers. Here we show that monomeric MxA(L612K) lacks detectable GTPase activity but is capable of inhibiting Thogoto virus in transiently transfected Vero cells or in a Thogoto virus minireplicon system. Likewise, MxA(L612K) inhibited vesicular stomatitis virus multiplication. These findings indicate that MxA monomers are antivirally active and suggest that GTP hydrolysis may not be required for antiviral activity. MxA(L612K) is rapidly degraded in cells, whereas wild-type MxA is stable. We propose that high-molecular-weight MxA oligomers represent a stable intracellular pool from which active MxA monomers are recruited.
Assuntos
Antivirais/metabolismo , GTP Fosfo-Hidrolases/metabolismo , Proteínas de Ligação ao GTP , Proteínas/metabolismo , Substituição de Aminoácidos , Animais , Antivirais/genética , Células COS , Chlorocebus aethiops , Guanosina Trifosfato/metabolismo , Humanos , Hidrólise , Mutagênese Sítio-Dirigida , Mutação , Proteínas de Resistência a Myxovirus , Proteínas/genética , Thogotovirus/fisiologia , Células Vero , Vírus da Estomatite Vesicular Indiana/fisiologia , Replicação ViralRESUMO
MxA protein is an interferon-induced GTPase of human cells that inhibits the multiplication of several RNA viruses, including influenza viruses and bunyaviruses. Studies on MxA transgenic mice have shown that MxA is a powerful antiviral agent in vivo. It has been suggested that this cellular protein also protects humans from viral disease, but the mechanism(s) by which MxA exerts its antiviral action is still poorly understood. Using an in vitro cosedimentation assay, we now demonstrate that MxA tightly interacts with components of the ribonucleoprotein complex of Thogoto virus, an influenza-like virus transmitted by ticks. This assay demonstrates for the first time a physical interaction between MxA GTPase and a viral target structure. It is based on three elements, namely, highly active MxA GTPases as effector molecules, viral ribonucleoprotein particles as viral targets, and GTPgammaS as a stabilizing factor. Furthermore, using a simple nuclear translocation assay, we show that human MxA protein forms oligomers in vivo. This assay provides a stringent test for tight association of partner molecules in intact mammalian cells. It not only will be useful for studying physical interactions of MxA with partner molecules, but may also be applicable to other studies on protein-protein interactions in living cells.
Assuntos
GTP Fosfo-Hidrolases/metabolismo , Proteínas de Ligação ao GTP , Guanosina Trifosfato/metabolismo , Proteínas/metabolismo , Vírus de RNA/metabolismo , Ribonucleoproteínas/metabolismo , Animais , Transporte Biológico , Biopolímeros , Núcleo Celular/metabolismo , Cromatografia em Gel , Escherichia coli/genética , GTP Fosfo-Hidrolases/genética , GTP Fosfo-Hidrolases/isolamento & purificação , Glutationa Transferase/metabolismo , Humanos , Camundongos , Proteínas de Resistência a Myxovirus , Testes de Precipitina , Ligação Proteica , Proteínas/genética , Proteínas/isolamento & purificação , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/isolamento & purificação , Proteínas Recombinantes de Fusão/metabolismoRESUMO
OBJECTIVE: To describe the process used to notify pediatric patients who received transfusions of blood or blood products at our institution before donor blood was routinely screened for antibodies to HIV (1985) and hepatitis C virus (1990), and to evaluate the effectiveness of the notification program. DESIGN: Patients who had received transfusions were identified through the hospital's medical records and the records from the Transfusion Medicine Laboratory. Patients were contacted by registered mail to provide notification of transfusion. A questionnaire was included with the notification to obtain information about the patient's awareness of the transfusion and whether he or she had undergone or planned to undergo testing for HIV and hepatitis C virus. SETTING: Tertiary care university-affiliated teaching hospital in Hamilton, Ont. PATIENTS: Patients 16 years of age or younger who had received blood products between February 1978 and November 1985. Patients who had received only albumin or immune serum globulin were not included as these products were not associated with viral transmission in Canada. RESULTS: Notification letters were sent to 1546 patients. Of these letters 522 (33.8%) were returned undelivered. Of the 1024 patients contacted 493 (48.1%) responded to the questionnaire, of whom 157 (31.8%) were not aware of their transfusion. A total of 130 (26.4%) of the respondents had already undergone testing for HIV, and 342 (69.4%) indicated that they would undergo such testing as a result of the notification. In contrast, only 30 (6.3%) of 474 respondents had undergone testing for hepatitis C virus, but 425 (89.7%) indicated that they would undergo such testing. Overall, the patients' response to the notification was neutral or positive; however, a number of patients expressed dissatisfaction and anxiety. CONCLUSIONS: The high proportion of patients who were unaware that they had undergone transfusion and who decided to undergo testing for HIV and hepatitis C virus as a result of notification supports the use of notification programs such as this one.
Assuntos
Infecção Hospitalar/prevenção & controle , Notificação de Doenças/métodos , Infecções por HIV/prevenção & controle , Hepatite C/prevenção & controle , Reação Transfusional , Adolescente , Atitude Frente a Saúde , Transfusão de Sangue/psicologia , Criança , Pré-Escolar , Hospitais Universitários , Humanos , Lactente , Programas de Rastreamento , Ontário , Avaliação de Programas e Projetos de Saúde , Inquéritos e QuestionáriosRESUMO
We established a system of receptor chimeras that enabled us to induce heterodimerization of different cytoplasmic tails. Fusion constructs were created that are composed of the extracellular parts of the interleukin-5 receptor alpha and beta chains, respectively, and the transmembrane and intracellular parts of gp130, the signal transducing chain of the interleukin-6 receptor complex. In COS-7 transfectants we observed a dose-dependent interleukin-5-inducible STAT1 activation for which the presence of both the alpha and the beta chain chimera was needed. No STAT activity was detected if one of the cytoplasmic tails of the receptor complex was deleted, indicating that STAT activity resulted from a receptor dimer rather than from higher receptor aggregates. We further investigated whether dimerization of STAT1 depends on the juxtaposition of two STAT recruitment modules in a receptor complex. We show that a receptor dimer with only a single STAT1 docking site was still able to lead to STAT1 activation. This indicates that the formation of a paired set of STAT binding sites in a receptor complex is not the prerequisite for STAT factor dimerization. Our findings are discussed in view of alternative STAT dimerization models.
Assuntos
Proteínas de Ligação a DNA/metabolismo , Receptores de Citocinas/metabolismo , Proteínas Recombinantes de Fusão/metabolismo , Transdução de Sinais , Transativadores/metabolismo , Animais , Células COS , Dimerização , Humanos , Receptores de Citocinas/genética , Proteínas Recombinantes de Fusão/genética , Fator de Transcrição STAT1 , TransfecçãoRESUMO
Distances between the metal ions bound to the product terminus i site and the substrate i + 1 site of Escherichia coli RNA polymerase range from 5.0 to 5.6 A when the substrate is complementary to a template base and from 6.5 to 7.0 A for a noncomplementary relationship. The metal bound to the substrate at the i + 1 site exhibits a constant distance to the three phosphates on the substrate regardless of complementarity, but the distance to base and ribose protons changes. The differences in these geometric parameters are explained by the ability of the enzyme to assume two conformations, one to place correct nucleotide substrates in optimal position for bond formation and the other to prevent incorrect nucleotides from assuming such a position. In this scheme a metal-triphosphate complex can move toward or away from the terminal 3' OH group of the growing RNA chain, to assure fidelity of transcription.
Assuntos
RNA Polimerases Dirigidas por DNA/metabolismo , Escherichia coli/enzimologia , Modelos Estruturais , Nucleotídeos/metabolismo , Transcrição Gênica , Composição de Bases , Sítios de Ligação , Metais/metabolismo , Modelos Moleculares , Conformação MolecularAssuntos
Programas de Assistência Gerenciada/economia , Transtornos Mentais/terapia , Serviços de Saúde Mental/economia , Psicoterapia/economia , Análise Custo-Benefício , Honorários Médicos , Sistemas Pré-Pagos de Saúde/economia , Humanos , Transtornos Mentais/economia , Transtornos Mentais/psicologia , Serviços de Saúde do Trabalhador/economia , Recidiva , Estados UnidosAssuntos
Maus-Tratos Infantis , Delitos Sexuais , Adolescente , Adulto , Alcoolismo/psicologia , Criança , Família , Feminino , Humanos , Incesto , Masculino , Transtornos Mentais/psicologia , PsicoterapiaRESUMO
Career training in child psychiatry, though provided from a developmental perspective, often lacks opportunity for directly observing normally developing infants. This paper describes a training program in which child psychiatry fellows, in collaboration with residents in pediatrics, follow a young couple and their first child from the third trimester of pregnancy through infancy and early childhood. Case illustrations and discussion of approximately 10 years' experience demonstrate how the program can enhance understanding of normal child development, development of the nuclear family, liaison between child psychiatrist and pediatrician and early detection of psychopathology in infants.
Assuntos
Desenvolvimento Infantil , Psiquiatria Infantil/educação , Adulto , Criança , Transtornos do Comportamento Infantil/terapia , Pré-Escolar , Currículo , Feminino , Humanos , Lactente , Recém-Nascido , Deficiência Intelectual/terapia , Masculino , Relações Pais-FilhoRESUMO
A review of the literature on family treatment of alcoholism suggests that although there is no single definition of family therapy, nor one single theory behind it, there is agreement that family therapy can be beneficial for both the alcoholic and the family.