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1.
Front Vet Sci ; 10: 1241080, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37885615

RESUMO

Obesity is the most common nutritional problem in companion animals today, and Australian British shorthair (BSH) cats have been shown to have a greater likelihood of being overweight relative to other cat breeds. The objectives of this research were to quantify bodyweight (BW) and body condition scores (BCSs) of BSH cats attending first opinion practice in Australia for the period 2008-2017 and to determine if: (1) being classified as overweight was associated with geographical location (urban versus rural and socio-economic index); and (2) BW recorded in the first 12 months of life was associated with length of life beyond 12 months. Electronic medical records from BSH cats were obtained from VetCompass Australia and used for BW and BCS analysis. Desexed males (n = 971) had the highest mean BW followed by entire males (n = 79), desexed females (n = 815), and entire females (n = 82). The desexed males, desexed females, and entire females had a mean BCS classified as overweight using a 1-to-9 point BCS scale. The entire male population was the only group with a mean BCS classified as ideal. No statistically significant association between BW and urban-rural status and no consistent trend between BW and socioeconomic deprivation was found. For cats with at least one BW measurement in the first 12 months of life that was ≤3.3 kg, the age when 20 percent of the group had died or were euthanised was 12.3 (95% CI 11.7 to 13.1) years. For cats with at least one BW measurement in the first 12 months of life that was ≥3.3 kg age, the age when 20 percent of the group had died or were euthanised was 6.6 (95% CI 5.2 to 6.6) years. This was a substantial clinical difference in survival. The study concluded that a large proportion of BSH cats attending first opinion veterinary clinics in Australia between 2008 and 2017 (48%) were classified as overweight. Cats less than 12 months of age that were greater than 3.3 kg had a shortened lifespan beyond 12 months of age compared with cats that were less than 3.3 kg.

2.
Skeletal Radiol ; 30(6): 305-11, 2001 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-11465769

RESUMO

OBJECTIVE: To determine the accuracy of T2*-weighted three-dimensional (3D) gradient-echo articular cartilage imaging in the identification of grades 3 and 4 chondromalacia of the knee. DESIGN AND PATIENTS: A retrospective evaluation of 80 patients who underwent both arthroscopic and MRI evaluation was performed. The 3D images were interpreted by one observer without knowledge of the surgical results. The medial and lateral femoral condyles, the medial and lateral tibial plateau, the patellar cartilage and trochlear groove were evaluated. MR cartilage images were considered positive if focal reduction of cartilage thickness was present (grade 3 chondromalacia) or if complete loss of cartilage was present (grade 4 chondromalacia). Comparison of the 3D MR results with the arthroscopic findings was performed. RESULTS: Eighty patients were included in the study group. A total of 480 articular cartilage sites were evaluated with MRI and arthroscopy. Results of MR identification of grades 3 and 4 chondromalacia, all sites combined, were: sensitivity 83%, specificity 97%, false negative rate 17%, false positive rate 3%, positive predictive value 87%, negative predictive value 95%, overall accuracy 93%. CONCLUSION: The results demonstrate that T2*-weighted 3D gradient-echo articular cartilage imaging can identify grades 3 and 4 chondromalacia of the knee.


Assuntos
Doenças das Cartilagens/patologia , Cartilagem Articular/patologia , Articulação do Joelho/patologia , Imageamento por Ressonância Magnética/métodos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Sensibilidade e Especificidade
3.
J Med Pract Manage ; 16(5): 258-60, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11345884

RESUMO

Although the world of medicine seems to be changing and progressing with each day, one thing that has not changed is the need for good documentation. The medical record of today does not only reflect your care of the patient, but has become a communication tool to a wide variety of players. Everyone seems to looking at your records, from colleagues to HMOs, and in the worst-case scenario, a plaintiff's attorney. This article will help show why good documentation is so important not only for good medical care, but if needed, as a defense tool if faced with a medical malpractice claim.


Assuntos
Documentação/métodos , Controle de Formulários e Registros/normas , Prontuários Médicos/normas , Humanos , Administração da Prática Médica
4.
Cancer Res ; 61(6): 2696-703, 2001 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-11289150

RESUMO

Placenta growth factor (PlGF) is a mitogen for endothelial cells that can potentiate the growth and permeabilizing effects on endothelium of vascular endothelial growth factor. Here we report that hypoxia induces the expression of both PlGF mRNA and protein in immortalized/transformed mouse embryonic fibroblasts (mEFs) and in NIH 3T3 cells. Importantly, the magnitude of the induction of PlGF expression by hypoxia is enhanced by the presence of oncogenic Ras. To investigate the transcriptional component of hypoxia-inducible PlGF expression, we cloned and sequenced a 1350-bp fragment of the 5'-flanking region of the mouse gene. Analysis of the promoter region indicated the presence of putative consensus sequences for known hypoxia-responsive regulatory sites, including metal response elements and Sp1-like sites. In the present study, we show that the induction of PlGF expression by hypoxia is dependent on the presence of the metal response element-binding transcription factor 1 (MTF-1). Thus, in mEFs with targeted deletions of both MTF-1 alleles, hypoxia-induced increases of PIGF mRNA and protein levels were greatly attenuated compared with those in wild-type mEFs. Moreover, transient transfection of a PlGF promoter reporter gene into NIH 3T3 cells resulted in hypoxia-responsive transcriptional activation of the reporter. Finally, ectopic expression of MTF-1 resulted in increased basal transcriptional activity of a PlGF promoter reporter. Together, these findings demonstrate that the PlGF gene is responsive to hypoxia and that this response is mediated by MTF-1. It remains to be determined whether this activation is the result of direct and/or indirect transcriptional activation by MTF-1. The stimulatory effect of oncogenic Ras on the induction of PlGF expression in hypoxic cells suggests that PlGF could be an important proangiogenic factor in the tumor microenvironment.


Assuntos
Regulação da Expressão Gênica no Desenvolvimento , Oxigênio/fisiologia , Proteínas da Gravidez/biossíntese , Fatores de Transcrição/fisiologia , Células 3T3 , Animais , Sequência de Bases , Hipóxia Celular , Linhagem Celular Transformada , Clonagem Molecular , DNA/genética , DNA/isolamento & purificação , Proteínas de Ligação a DNA , Embrião de Mamíferos , Fibroblastos/metabolismo , Fibroblastos/fisiologia , Regulação Neoplásica da Expressão Gênica , Genes ras/fisiologia , Humanos , Camundongos , Dados de Sequência Molecular , Fator de Crescimento Placentário , Proteínas da Gravidez/genética , Regiões Promotoras Genéticas , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Ativação Transcricional/fisiologia , Células Tumorais Cultivadas , Fator MTF-1 de Transcrição
6.
Plast Reconstr Surg ; 105(7): 2500-12; discussion 2513-4, 2000 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-10845308

RESUMO

Less than 1 percent of the women interested in having larger breasts elect to have surgical augmentation mammaplasty with insertion of breast implants. The purpose of this report is to describe and test the efficacy of a nonsurgical method for breast enlargement that is based on the ability of tissues to grow when subjected to controlled distractive mechanical forces. Seventeen healthy women (aged 18 to 40 years) who were motivated to achieve breast enlargement were enrolled in a single-group study. The participants were asked to wear a brassiere-like system that applies a 20-mmHg vacuum distraction force to each breast for 10 to 12 hours/day over a 10-week period. Breast size was measured by three separate methods at regular intervals during and after treatment. Breast tissue water density and architecture were visualized before and after treatment by magnetic resonance imaging scans obtained in the same phase of the menstrual cycle. Twelve subjects completed the study; five withdrawals occurred due to protocol noncompliance. Breast size increased in all women over the 10-week treatment course and peaked at week 10 (final treatment); the average increase per woman was 98 +/- 67 percent over starting size. Partial recoil was seen in the first week after terminating treatment, with no significant further size reduction after up to 30 weeks of follow-up. The stable long-term increase in breast size was 55 percent (range, 15 to 115 percent). Magnetic resonance images showed no edema and confirmed the proportionate enlargement of both adipose and fibroglandular tissue components. A statistically significant decrease in body weight occurred during the course of the study, and scores on the self-esteem questionnaire improved significantly. All participants were very pleased with the outcome and reported that the device was comfortable to wear. No adverse events were recorded during the use of the device or after treatment. We conclude that true breast enlargement can be achieved with the daily use of an appropriately designed external expansion system. This nonsurgical and noninvasive alternative for breast enlargement is effective and well tolerated.


Assuntos
Mama/anormalidades , Expansão de Tecido/instrumentação , Expansão de Tecido/métodos , Adulto , Feminino , Humanos , Pressão , Resultado do Tratamento , Vácuo
7.
J Hematother Stem Cell Res ; 9(2): 205-14, 2000 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-10813533

RESUMO

A short phosphorothioate oligodeoxynucleotide telomere mimic with the sequence 5'-d(TTAGGG)-3', TAG-6, has been shown to inhibit telomerase activity and have antineoplastic and hematopoietic stimulatory properties. In this study, three immature male domestic swine (weighing approximately 40 kg) were administered 200 mg/m2 of TAG-6 by continuous intravascular infusion at rates of 0.48 +/- 0.07 mg/hr for 14 days to evaluate the pharmacokinetics, toxicity, and tissue distribution. There was considerable variability (both within each animal and across animals) observed in the pharmacokinetic data. The plasma half-life (t1/2 appeared to be short enough that it could be assumed that steady state was attained by at least 96 h after the start of the infusion. The t1/2 estimates for the three pigs were 8.96, 109, and 1.97 h (the long t1/2 for pig 2 may be explained by poor parameter estimation due to the variability). The volume of distribution ranged from 9.80 to 51.8 L (0.3-1.4 L/kg), and plasma clearance estimates ranged from 0.33 to 3.46 L/h (5.5-57.7 ml/min). The average plasma concentrations at steady state were 0.845, 0.933, and 0.178 microg/ml (0.44, 0.49, and 0.093 microM) for the three animals. Nearly 30% of the administered dose was cleared through renal excretion by day 7 postinfusion. The distribution of TAG-6 was primarily to the liver and kidney, but the spleen and thyroid accumulated relatively high concentrations of TAG-6. TAG-6 was metabolized to apparently higher molecular weight products, which were observed in the urine. The size periodicity of these apparently higher molecular weight products was in 6-base intervals, which is consistent with the actions of telomerase. The infusion did not produce significant changes in serum chemistry or circulating blood cells, but a decrease in colony-forming unit-granulocyte-monocyte (CFU-GM) colony formation from BM was observed. These data suggest that TAG-6 may be a very specific pharmacophore.


Assuntos
Antineoplásicos/farmacocinética , Hematopoese/efeitos dos fármacos , Tionucleotídeos/farmacocinética , Animais , Antineoplásicos/toxicidade , Antineoplásicos/urina , Análise Química do Sangue , Eletroforese , Rim/metabolismo , Cinética , Masculino , Suínos , Tionucleotídeos/sangue , Tionucleotídeos/urina , Distribuição Tecidual , Urina/química
8.
Cancer Res ; 59(6): 1315-22, 1999 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-10096565

RESUMO

Metallothioneins (MTs) are a family of stress-induced proteins with diverse physiological functions, including protection against metal toxicity and oxidants. They may also contribute to the regulation of cellular proliferation, apoptosis, and malignant progression. We reported previously that the human (h)MT-IIA isoform is induced in carcinoma cells (A431, SiHa, and HT29) exposed to low oxygen, conditions commonly found in solid tumors. The present study demonstrates that the genes for hMT-IIA and mouse (m)MT-I are transcriptionally activated by hypoxia through metal response elements (MREs) in their proximal promoter regions. These elements bind metal transcription factor-1 (MTF-1). Deletion and mutational analyses of the hMT-IIA promoter indicated that the hMRE-a element is essential for basal promoter activity and for induction by hypoxia, but that other elements contribute to the full transcriptional response. Functional studies of the mMT-I promoter demonstrated that at least two other MREs (mMRE-d and mMRE-c) are responsive to hypoxia. Multiple copies of either hMRE-a or mMRE-d conferred hypoxia responsiveness to a minimal MT promoter. Mouse MT-I gene transcripts in fibroblasts with targeted deletions of both MTF-1 alleles (MTF-1(-/-); dko7 cells) were not induced by zinc and showed low responsiveness to hypoxia. A transiently transfected MT promoter was unresponsive to hypoxia or zinc in dko7 cells, but inductions were restored by cotransfecting a mouse MTF-1 expression vector. Electrophoretic mobility shift assays detected a specific protein-DNA complex containing MTF-1 in nuclear extracts from hypoxic cells. Together, these results demonstrate that hypoxia activates MT gene expression through MREs and that this activation involves MTF-1.


Assuntos
Regulação Neoplásica da Expressão Gênica , Metalotioneína/genética , Oxigênio/metabolismo , Regiões Promotoras Genéticas , Fatores de Transcrição/metabolismo , Células 3T3 , Animais , Ligação Competitiva , Hipóxia Celular/genética , Proteínas de Ligação a DNA , Fibroblastos/metabolismo , Células HT29 , Humanos , Metalotioneína/biossíntese , Metais/metabolismo , Camundongos , Oxirredução , RNA Mensageiro/biossíntese , Fatores de Transcrição/genética , Células Tumorais Cultivadas , Fator MTF-1 de Transcrição
9.
Biochem Biophys Res Commun ; 256(2): 429-35, 1999 Mar 16.
Artigo em Inglês | MEDLINE | ID: mdl-10079202

RESUMO

The human immunodeficiency virus-1 (HIV-1) utilises CD4 and certain beta-chemokine receptors, mainly CCR-5 and CXCR4, for attachment and virus entry into T-lymphocytes and monocytes/macrophages. CD4 and beta-chemokine receptors participate in intracellular signalling via protein tyrosine kinases and G-protein-coupled signalling. The factors which influence HIV-1 replication and the intracellular signalling mechanisms elicited by the virus are not well understood. In this study, it was demonstrated that exposure of peripheral blood lymphocytes (PBLs) to a T-cell tropic strain of HIV-1 evokes signal(s) which results in downregulation of intracellular cAMP. In addition, pre-incubation of PBLs with the Gi-protein inhibitor Pertussis toxin mediated a significant inhibition of HIV-1 replication. These data strongly suggest that HIV-1 employs CD4 receptors and Gi-coupled proteins for entry into target cells and that productive HIV-1 infection is dependent on an active signalling event.


Assuntos
AMP Cíclico/metabolismo , Proteínas de Ligação ao GTP/fisiologia , HIV-1/fisiologia , Linfócitos/virologia , Toxina Pertussis , Transdução de Sinais , Fatores de Virulência de Bordetella/farmacologia , Benzoquinonas , Antígenos CD4/metabolismo , Divisão Celular , Sobrevivência Celular/efeitos dos fármacos , Regulação para Baixo/efeitos dos fármacos , Citometria de Fluxo , Imunofluorescência , Subunidades alfa Gi-Go de Proteínas de Ligação ao GTP/antagonistas & inibidores , Subunidades alfa Gi-Go de Proteínas de Ligação ao GTP/fisiologia , Proteínas de Ligação ao GTP/antagonistas & inibidores , Proteína do Núcleo p24 do HIV/metabolismo , HIV-1/patogenicidade , Humanos , Lactamas Macrocíclicas , Linfócitos/citologia , Proteínas Tirosina Quinases/antagonistas & inibidores , Proteínas Tirosina Quinases/metabolismo , Quinonas/farmacologia , Receptores CXCR4/metabolismo , Rifabutina/análogos & derivados , Transdução de Sinais/efeitos dos fármacos , Fatores de Tempo , Replicação Viral/efeitos dos fármacos
11.
Biochem Biophys Res Commun ; 252(1): 69-77, 1998 Nov 09.
Artigo em Inglês | MEDLINE | ID: mdl-9813148

RESUMO

Proper function of the protein tyrosine phosphatase CD45 is required for the positive regulation of the activity of src tyrosine kinases p56lck and p59fyn which participate in T-cell receptor and CD4 receptor signalling. In this study, the effect of HIV-1 infection on the function of CD45-associated tyrosine phosphatase activity in the H9 T-cell line has been investigated with respect to CD3 and CD4 ligation. A significant reduction in CD45-associated phosphatase activity was observed following CD3 + CD4 ligation in virally infected cells, whereas CD45 activity was not compromised following CD3 receptor ligation. Dysfunctional CD45 activity in infected cells was not attributable to reduced receptor surface expression induced by HIV-1, since CD4, CD3 and CD45 expression levels were found to be intact. Defective CD45 activity correlated with inhibted downstream signalling events as evidenced by reduced CD4-associated tyrosine kinase activity and inhibition of PLC-gamma1. Impaired CD45 function is likely to play a critical role in the inhibition of CD3/CD4 signalling thereby contributing to HIV-1 pathogenesis.


Assuntos
Complexo CD3/fisiologia , Antígenos CD4/fisiologia , HIV-1/fisiologia , Antígenos Comuns de Leucócito/fisiologia , Proteínas Tirosina Fosfatases/metabolismo , Transdução de Sinais , Sequência de Aminoácidos , Linhagem Celular , Meios de Cultura Livres de Soro , Gastrinas/química , Gastrinas/metabolismo , Proteína do Núcleo p24 do HIV/análise , HIV-1/imunologia , Humanos , Dados de Sequência Molecular , Proteínas Tirosina Quinases/metabolismo , Receptor Cross-Talk , Especificidade por Substrato
12.
Carcinogenesis ; 19(8): 1333-7, 1998 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-9744525

RESUMO

Transient transfection studies of human HepG2 and mouse Hepa hepatocarcinoma cells with a reporter gene construct regulated by a human antioxidant responsive element (ARE) from the NQO1 gene demonstrated that the element is responsive to low oxygen conditions. The antioxidant N-acetyl L-cysteine (NAC) strongly inhibited basal aerobic reporter gene activity in HepG2 cells without obviously affecting the hypoxic induction, as is consistent with ARE sensitivity to oxidative stress in aerobic cultures. Electrophoretic mobility shift (EMS) assays of nuclear extracts of HepG2 and Hepa cells lysed under aerobic or hypoxic conditions or after exposure to the phenolic compound 3-(2)-tert-butyl-4-hydroxyanisole (BHA), showed specific and constitutive protein binding to the ARE under all of these conditions. Taken together, these findings show that the ARE can mediate gene expression in response to low oxygen conditions. Co-ordinately regulated expression of ARE-dependent genes, such as phase II detoxification enzymes, may be an important phenotype of solid tumors containing significant regions of pathophysiological hypoxia.


Assuntos
Cloranfenicol O-Acetiltransferase/metabolismo , Regulação Enzimológica da Expressão Gênica , NAD(P)H Desidrogenase (Quinona)/metabolismo , Transativadores/fisiologia , Acetilcisteína/farmacologia , Animais , Hidroxianisol Butilado/farmacologia , Hipóxia Celular , Cloranfenicol O-Acetiltransferase/antagonistas & inibidores , Cloranfenicol O-Acetiltransferase/genética , Sequestradores de Radicais Livres/farmacologia , Genes Reporter , Humanos , Camundongos , NAD(P)H Desidrogenase (Quinona)/genética , Oxirredução , Células Tumorais Cultivadas
13.
J Biol Chem ; 273(40): 25783-8, 1998 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-9748250

RESUMO

The voltage-sensitive sodium channel is regulated by cAMP-dependent protein kinase (PKA) phosphorylation. Using purified preparations of rat brain sodium channels, we have shown that the alpha subunit was phosphorylated by a co-purifying protein kinase. The co-purifying kinase was stimulated by cAMP and phosphorylated PKA substrate peptides. Both the regulatory and catalytic subunits of PKA were detected by immunoblotting in purified sodium channel preparations. Bound PKA was immunoprecipitated with anti-SP19 antibodies directed against the sodium channel alpha subunit. PKA bound to sodium channels phosphorylated the sodium channel alpha subunit on the same four serine residues as observed with exogenously added PKA, indicating that association with the sodium channel does not restrict the sites of phosphorylation. Analysis of proteins with high affinity for the type II alpha regulatory subunit of PKA in a gel overlay assay identified a 15-kDa cAMP-dependent protein kinase-anchoring protein (AKAP) in these preparations. Determination of its amino acid sequence by mass spectrometry revealed two peptides identical to AKAP15, a recently described AKAP that targets PKA to skeletal muscle calcium channels. The co-purifying AKAP was also immunoreactive with antibodies generated against AKAP15, and antibodies directed against AKAP15 co-immunoprecipitated the sodium channel. Our results indicate that PKA is bound to brain sodium channels through interaction with AKAP15. Association of AKAP15 with both skeletal muscle calcium channels and brain sodium channels suggests that it may have broad specificity in targeting PKA to ion channels for regulation.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal , Encéfalo/metabolismo , Proteínas de Transporte/química , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Proteínas de Membrana/química , Canais de Sódio/química , Proteínas de Ancoragem à Quinase A , Sequência de Aminoácidos , Animais , Canais de Cálcio/metabolismo , Proteína Quinase Tipo II Dependente de AMP Cíclico , Eletroforese em Gel Bidimensional , Dados de Sequência Molecular , Músculo Esquelético/fisiologia , Fosfopeptídeos/química , Fosforilação , Testes de Precipitina , Ligação Proteica/fisiologia , Ratos , Análise de Sequência
14.
Neuron ; 20(5): 1017-26, 1998 May.
Artigo em Inglês | MEDLINE | ID: mdl-9620705

RESUMO

Rapid, voltage-dependent potentiation of skeletal muscle L-type calcium channels requires phosphorylation by cAMP-dependent protein kinase (PKA) anchored via an A kinase anchoring protein (AKAP). Here we report the isolation, primary sequence determination, and functional characterization of AKAP15, a lipid-anchored protein of 81 amino acid residues with a single amphipathic helix that binds PKA. AKAP15 colocalizes with L-type calcium channels in transverse tubules and is associated with L-type calcium channels in transfected cells. A peptide fragment of AKAP15 encompassing the RII-binding domain blocks voltage-dependent potentiation. These results indicate that AKAP15 targets PKA to the calcium channel and plays a critical role in voltage-dependent potentiation and regulation of skeletal muscle contraction. The expression of AKAP15 in the brain and heart suggests that it may mediate rapid PKA regulation of L-type calcium channels in neurons and cardiac myocytes.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal , Canais de Cálcio/metabolismo , Proteínas de Transporte/genética , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Proteínas de Membrana/genética , Músculo Esquelético/química , Proteínas de Ancoragem à Quinase A , Acetilação , Sequência de Aminoácidos , Animais , Northern Blotting , Canais de Cálcio/análise , Canais de Cálcio Tipo L , Proteínas de Transporte/análise , Proteínas de Transporte/metabolismo , Linhagem Celular , Sequência Consenso , Proteínas Quinases Dependentes de AMP Cíclico/genética , Regulação Enzimológica da Expressão Gênica/fisiologia , Humanos , Ativação do Canal Iônico/fisiologia , Rim/citologia , Proteínas de Membrana/análise , Proteínas de Membrana/metabolismo , Microssomos/química , Microssomos/enzimologia , Dados de Sequência Molecular , Contração Muscular/fisiologia , Proteínas Musculares/análise , Proteínas Musculares/metabolismo , Músculo Esquelético/enzimologia , Mutagênese/fisiologia , Testes de Precipitina , Ligação Proteica/fisiologia , RNA Mensageiro/análise , Coelhos , Ratos
15.
Radiat Res ; 149(2): 147-54, 1998 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-9457894

RESUMO

Minimal residual disease in lymphoma patients is a major problem in the clinical management of their cancer. High-dose chemotherapy followed by autologous bone marrow transplantation has been used to treat the disease. However, residual lymphoma may be reintroduced along with the marrow if it is present in the bone marrow harvest. In this report we describe results of experiments testing the efficacy of 5-[125I]-iodo-2'-deoxyuridine (125IdU) for purging murine RAW117 large cell lymphoma cells (Joshi et al., Oncology 44, 180-185, 1987; Cancer Res. 47, 3551-3557, 1987) from bone marrow in a relevant animal model. Donor BALB/c mice were injected with murine RAW117 cells and euthanized on day 13, and their bone marrow that had been contaminated with tumor cells was harvested and treated in vitro with 125IdU or nonradioactive 127IdU (control). Nine of 10 mice receiving 127IdU-treated bone marrow contaminated with tumor cells died at an average of 17 days after injection. In comparison, 9 of 10 mice injected with 125IdU-treated bone marrow contaminated with tumor cells were still alive after 82 days. In addition, the 125IdU treatment did not diminish the formation of hematopoietic progenitor cell colonies in normal mouse and human peripheral blood stem cells.


Assuntos
Células da Medula Óssea/efeitos da radiação , Purging da Medula Óssea/métodos , Idoxuridina/uso terapêutico , Linfoma/radioterapia , Animais , Ciclo Celular , Feminino , Células-Tronco Hematopoéticas/efeitos da radiação , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Análise de Sobrevida
16.
Trends Cardiovasc Med ; 8(2): 89-95, 1998 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21235917

RESUMO

The precision of cAMP-responsive events is controlled in part through compartmentalization of the signal transduction machinery. Recent evidence suggests that the cAMP-dependent protein kinase (PKA) is localized to specific subcellular compartments through association with A Kinase Anchoring Proteins (AKAPs). The AKAPs now represent a functionally related family of regulatory proteins that contain a conserved PKA binding domain and unique targeting sequences that direct the PKA-AKAP complex to subcellular structures. In this review, the recent evidence suggesting that AKAPs facilitate PKA anchoring close to key membrane substrates, such as glutamate receptors, calcium-activated potassium channels, and skeletal or cardiac muscle calcium channels, is surveyed.

17.
Virology ; 238(1): 94-102, 1997 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-9375013

RESUMO

An in vitro model was developed to replicate hepatitis E virus (HEV) in normal primary cynomolgus macaque hepatocytes using a hormonally defined, serum-free medium formulation. Primary hepatocytes were infected in tissue culture following isolation by collagenase treatment of liver wedge biopsy material. Viral replication was monitored by a highly strand-specific reverse transcription-polymerase chain reaction (RT-PCR) assay, which could detect the positive- and negative-strands of HEV RNA independently in a sensitive and specific manner. Several infectious HEV (Burma strain) inocula were titered by this RT-PCR assay, and a minimum effective infectious dose was determined. Appearance of newly replicated virus was demonstrated by detection of both strands of HEV RNA in experimentally infected hepatocytes as well as the genomic positive-strand viral RNA in the culture medium. Infectivity of the virus particles present in the media was confirmed by serial passage and replication of the virus in culture. Using this in vitro infection system, a neutralization assay was developed to assess the ability of anti-HEV antibodies to block virus infection of liver cells. Results presented in this report represent the first in vitro demonstration of a neutralizing anti-HEV antibody directed against the ORF2-encoded putative capsid protein.


Assuntos
Vírus da Hepatite E/fisiologia , Fígado/virologia , RNA Viral/análise , Replicação Viral , Animais , Capsídeo/biossíntese , Capsídeo/imunologia , Técnicas de Cultura de Células/métodos , Células Cultivadas , Meios de Cultura Livres de Soro , Vírus da Hepatite E/genética , Vírus da Hepatite E/patogenicidade , Imunoglobulina G/sangue , Fígado/citologia , Macaca fascicularis , Testes de Neutralização , Reação em Cadeia da Polimerase/métodos , RNA Viral/genética , Coelhos , Sensibilidade e Especificidade
18.
J Biol Chem ; 272(10): 6297-302, 1997 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-9045648

RESUMO

Voltage-dependent potentiation of skeletal muscle L-type calcium channels requires phosphorylation by cAMP-dependent protein kinase (PKA) that is localized by binding to a cAMP-dependent protein kinase-anchoring protein (AKAP). L-type calcium channels purified from rabbit skeletal muscle contain an endogenous co-purifying protein kinase activity that phosphorylates the alpha1 and beta subunits of the channel. The co-purifying kinase also phosphorylates a known PKA peptide substrate, is stimulated by cAMP, and is inhibited by PKA inhibitor peptide-(5-24), indicating that it is PKA. PKA activity co-immunoprecipitates with the calcium channel, suggesting that the channel and the kinase are physically associated. Using biotinylated type II regulatory subunit of PKA (RII) as a probe, we have identified a 15-kDa RII-binding protein in purified calcium channel preparations, which we have designated AKAP-15. Anti-peptide antibodies directed against the alpha1 subunit of the calcium channel co-immunoprecipitate AKAP-15. Together, these findings demonstrate a physical link between PKA and the calcium channel and suggest that AKAP-15 may mediate their interaction.


Assuntos
Canais de Cálcio/metabolismo , Proteínas de Transporte/metabolismo , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Músculo Esquelético/química , Sequência de Aminoácidos , Animais , AMP Cíclico/metabolismo , Proteína Quinase Tipo II Dependente de AMP Cíclico , Substâncias Macromoleculares , Dados de Sequência Molecular , Peptídeos/química , Fosforilação , Testes de Precipitina , Ligação Proteica , Coelhos
19.
J Hematother ; 6(6): 551-61, 1997 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-9483190

RESUMO

Detection of small numbers of breast cancer cells in patient blood, aphereses, and bone marrow has become increasingly important as data have accumulated showing immunocytochemically (ICC) positive tumor cells in up to 50% of women with stage I and II breast cancer, who were initially thought to be cured of their disease but later relapsed. The ability to rule out the presence of micrometastatic disease at any stage of the clinical management protocol, whether before, during, or after therapy, would provide a useful monitoring and diagnostic tool for both the clinician and the scientist. Monitoring for the presence of minimal residual disease (MRD) is traditionally performed using ICC. A more recently established RT-PCR technique uses a molecular marker (the presence of the cytokeratin 19, CK19, transcript) to identify MRD in patient samples, with a level of sensitivity reported to be one tumor cell in 10(6) nucleated cells. This level of sensitivity is generally higher than that claimed for ICC. Based on the discriminating results of this first study, a number of laboratories have evaluated this technique for its diagnostic potential. Results from several laboratories showed a higher than expected false positive rate due to a variety of identified and unidentified sources. Therefore, the current study was designed to achieve two aims: to establish the level of sensitivity and specificity of the RT-PCR technique and to dissect out the possible variables that may contribute to a false positive result using this molecular approach. To accomplish the first goal, two simulation strategies were used, limited dilution of tumor cells into apheresis harvests and semi-quantitative PCR using stepwise dilutions of extracted RNA from tumor cells in apheresis harvests. The second goal was accomplished by performing sequential blood drawings with variably timed sample processing to identify some of the more common variables (time, anticoagulant, sample sequence) that may contribute to false positive results. Of three variables investigated, including type of blood preservative, sequence of blood tube collection, and time point of sample processing, each may contribute to a false positive result. In addition to these problems, known events involving illegitimate transcription of specific genes nonspecifically in tissue is also a potential source of false positive results. These issues may be further compounded by lack of attention to the more common methodologic problems encountered in any laboratory using the PCR technique. However, recommendations can be developed for the effective application of this technique, whose greatest strength is the demonstration of tumor negativity of the sample.


Assuntos
Células da Medula Óssea , Neoplasias da Mama/patologia , Imuno-Histoquímica , Queratinas/análise , Células Neoplásicas Circulantes/química , Reação em Cadeia da Polimerase , DNA Polimerase Dirigida por RNA , Anticoagulantes/sangue , Coleta de Amostras Sanguíneas , Células da Medula Óssea/química , Reações Falso-Positivas , Feminino , Humanos , Queratinas/genética , Leucócitos Mononucleares/química , Sensibilidade e Especificidade , Células Tumorais Cultivadas/química
20.
J Biol Chem ; 271(46): 28837-43, 1996 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-8910529

RESUMO

The voltage-sensitive Na+ channel is responsible for generating action potentials in the heart which are critical for coordinated cardiac muscle contraction. Cardiac Na+ channels are regulated by cAMP-dependent phosphorylation, but the sites of phosphorylation are not known. Using mammalian cells expressing the rat cardiac Na+ channel (rH1) alpha subunit and site-specific antibodies, we have shown that the alpha subunit of rat heart Na+ channel is phosphorylated selectively by cAMP-dependent protein kinase (PKA) in vitro and in intact cells. Analysis of the sites of phosphorylation by two-dimensional phosphopeptide mapping and site-directed mutagenesis of fusion proteins revealed that the cardiac alpha subunit is phosphorylated selectively in vitro by PKA on Ser526 and Ser529 in the intracellular loop connecting homologous domains I and II (LI-II). These two residues were phosphorylated in intact cells expressing the rH1 alpha subunit when PKA was activated. Our results define a different pattern of phosphorylation of LI-II of cardiac and brain Na+ channels and implicate phosphorylation of Ser526 and Ser529 in the differential regulation of cardiac and brain Na+ channels by PKA.


Assuntos
AMP Cíclico/metabolismo , Miocárdio/metabolismo , Canais de Sódio/metabolismo , Sequência de Aminoácidos , Animais , Sítios de Ligação , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Ativação Enzimática , Glutationa Transferase/genética , Dados de Sequência Molecular , Mutagênese Sítio-Dirigida , Mapeamento de Peptídeos , Fosforilação , Ratos , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo , Serina/metabolismo , Canais de Sódio/química , Canais de Sódio/genética
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