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1.
Transfusion ; 63(12): 2328-2340, 2023 12.
Artigo em Inglês | MEDLINE | ID: mdl-37942518

RESUMO

BACKGROUND: Red blood cell wastage occurs when blood is discarded rather than transfused, and ineffective ordering results in unnecessary crossmatch procedures. We describe how a multimodal approach to redesigning electronic ordering tools improved blood utilization in a pediatric inpatient setting and how using innovative application of time series data analysis provides insights into intervention effectiveness, which can guide future process improvement cycles. METHODS: A multidisciplinary team used best practices and Toyota Production System methodology to redesign electronic blood ordering and improve administration processes. We analyzed crossmatch to transfusion ratio and red blood cell wastage time series data extracted from our laboratory information system and electronic health record. We used changepoint analysis to identify statistically discernible breaks in each time series, compatible with known interventions. We performed causal impact analysis on red blood cell wastage time series data to estimate blood wastage avoided due to the interventions. RESULTS: Changepoint analysis estimated an 11% decrease in crossmatch to transfusion ratio and a 77% decrease in red blood cell monthly wastage rate during the intervention period. Causal impact analysis estimated a 61% reduction in expected wastage compared to the scenario if the interventions had not occurred. DISCUSSION: Our results show that electronic health record design is an important factor in reducing waste and preventing unnecessary crossmatching, and that time series analysis can be a useful tool for evaluating the long-term impact of each stage of intervention in a longitudinal process redesign effort for the purpose of effectively targeting future improvement efforts.


Assuntos
Transfusão de Sangue , Hospitais Pediátricos , Humanos , Criança , Fluxo de Trabalho , Transfusão de Sangue/métodos , Tipagem e Reações Cruzadas Sanguíneas , Eritrócitos
2.
Br J Anaesth ; 120(4): 629-644, 2018 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-29576105

RESUMO

QT prolongation can be attributable to various causes that can be categorised as acquired or congenital. Arrhythmias related to QT prolongation can result in clinical presentations, such as syncope and sudden cardiac death. The perioperative period presents a number of issues that may affect a patient's risk of developing polymorphic ventricular tachycardia or torsades de pointes. Although most patients may have an unremarkable perioperative course, some may have complications; this review article aims to help clinicians avoid potential complications, and to help them address treatment for perioperative issues that may occur.


Assuntos
Síndrome do QT Longo/cirurgia , Assistência Perioperatória/métodos , Humanos , Síndrome do QT Longo/congênito
3.
Nat Cell Biol ; 3(9): 823-30, 2001 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-11533662

RESUMO

Desmosomes are intercellular junctions of epithelia and are of widespread importance in the maintenance of tissue architecture. We provide evidence that desmosomal adhesion has a function in epithelial morphogenesis and cell-type-specific positioning. Blocking peptides corresponding to the cell adhesion recognition (CAR) sites of desmosomal cadherins block alveolar morphogenesis by epithelial cells from mammary lumen. Desmosomal CAR-site peptides also disrupt positional sorting of luminal and myoepithelial cells in aggregates formed by the reassociation of isolated cells. We demonstrate that desmosomal cadherins and E-cadherin are comparably involved in epithelial morphoregulation. The results indicate a wider role for desmosomal adhesion in morphogenesis than has previously been considered.


Assuntos
Caderinas/fisiologia , Adesão Celular/fisiologia , Proteínas do Citoesqueleto/fisiologia , Desmossomos/fisiologia , Células Epiteliais/citologia , Células Epiteliais/fisiologia , Animais , Sítios de Ligação , Mama/citologia , Caderinas/química , Caderinas/genética , Bovinos , Agregação Celular , Técnicas de Cultura de Células/métodos , Linhagem Celular , Tamanho Celular , Células Cultivadas , Proteínas do Citoesqueleto/química , Desmoplaquinas , Feminino , Regulação da Expressão Gênica , Humanos , Integrinas/análise , Integrinas/fisiologia , Glândulas Mamárias Animais/citologia , Camundongos , Morfogênese , Alvéolos Pulmonares/citologia , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transcrição Gênica
4.
Mol Biol Cell ; 16(2): 943-53, 2005 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-15574883

RESUMO

Senescence, the molecular program that limits the finite proliferative potential of a cell, acts as an important barrier to protect the body from cancer. Techniques for measuring transcriptome changes and for modulating their expression suggest that it may be possible to dissect the transcriptional networks underlying complex cellular processes. HMF3A cells are conditionally immortalized human mammary fibroblasts that can be induced to undergo coordinated senescence. Here, we used these cells in conjunction with microarrays, RNA interference, and in silico promoter analysis to promote the dissection of the transcriptional networks responsible for regulating cellular senescence. We first identified changes in the transcriptome when HMF3A cells undergo senescence and then compared them with those observed upon replicative senescence in primary human mammary fibroblasts. In addition to DUSP1 and known p53 and E2F targets, a number of genes such as PHLDA1, NR4A3, and a novel splice variant of STAC were implicated in senescence. Their role in senescence was then analyzed by RNA silencing followed by microarray analysis. In silico promoter analysis of all differential genes predicted that nuclear factor-kappaB and C/EBP transcription factors are activated upon senescence, and we confirmed this by electrophoretic mobility shift assay. The results suggest a putative signaling network for cellular senescence.


Assuntos
Senescência Celular , Senescência Celular/genética , Fibroblastos/metabolismo , Transcrição Gênica , Proteínas de Ciclo Celular/genética , Linhagem Celular Transformada , Células Cultivadas , Senescência Celular/fisiologia , Meios de Cultura Livres de Soro , Proteínas de Ligação a DNA/genética , Fosfatase 1 de Especificidade Dupla , Ensaio de Desvio de Mobilidade Eletroforética , Feminino , Regulação da Expressão Gênica , Inativação Gênica , Humanos , Proteínas Imediatamente Precoces/genética , Glândulas Mamárias Humanas/citologia , Análise em Microsséries , Modelos Biológicos , NF-kappa B/metabolismo , Proteínas do Tecido Nervoso/genética , Fosfoproteínas Fosfatases/genética , Regiões Promotoras Genéticas , Proteína Fosfatase 1 , Proteínas Tirosina Fosfatases/genética , Interferência de RNA , Splicing de RNA , Receptores de Esteroides , Receptores dos Hormônios Tireóideos , Retroviridae/genética , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Proteína Supressora de Tumor p53/genética
6.
Structure ; 3(6): 541-9, 1995 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-8590015

RESUMO

BACKGROUND: The collagenases are members of the family of zinc-dependent enzymes known as the matrix metalloproteinases (MMPs). They are the only proteinases that specifically cleave the collagen triple helix, and are important in a large number of physiological and pathological processes. Structures are known for the N-terminal catalytic' domain of collagenases MMP-1 and MMP-8 and of stromelysin (MMP-3). This catalytic domain alone, which comprises about 150 amino acids, has no activity against collagen. A second domain, of 200 amino acids, is homologous to haemopexin, a haem-binding glycoprotein. RESULTS: The crystal structure of full-length MMP-1 at 2.5 A resolution gives an R-factor of 21.7%. Two domains are connected by an exposed proline-rich linker of 17 amino acids, which is probably flexible and has no secondary structure. The catalytic domain resembles those previously observed, and contains three calcium-binding sites. The haemopexin-like domain contains four units of four-stranded antiparallel beta sheet stabilized on its fourfold axis by a cation, which is probably calcium. The domain constitutes a four-bladed beta-propeller structure in which the blades are scarcely twisted. CONCLUSIONS: The exposed linker accounts for the difficulty in purifying full-length collagenase. The C-terminal domain provides a structural model for haemopexin and its homologues. It controls the specificity of MMPs, affecting both substrate and inhibitor binding, although its role remains obscure. These structural results should aid the design of site-specific mutants which will reveal further details of the specificity mechanism.


Assuntos
Cálcio/metabolismo , Colagenases/química , Colagenases/metabolismo , Dobramento de Proteína , Membrana Sinovial/enzimologia , Sequência de Aminoácidos , Animais , Cromatografia de Afinidade , Cristalografia por Raios X , Hemopexina/química , Humanos , Ácidos Hidroxâmicos/química , Ácidos Hidroxâmicos/farmacologia , Metaloproteinase 1 da Matriz , Inibidores de Metaloproteinases de Matriz , Dados de Sequência Molecular , Conformação Proteica , Proteínas Recombinantes/química , Suínos
7.
J Natl Cancer Inst ; 77(2): 343-9, 1986 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-2426509

RESUMO

An immunohistological study in the human breast and the rodent breast (from inbred Ludwig/Wistar/Olac rats) was conducted with the use of a murine monoclonal antibody, which reacts with the common acute lymphoblastic antigen, a glycosylated polypeptide of a molecular weight of 100,000. The epitope, as recognized by this antibody, is expressed on myoepithelial cells of the normal human and rat breasts and was studied in the developing rodent mammary gland. Ultrastructural studies in the normal human breast clearly demonstrated the presence of the antigen on the lateral membrane of the myoepithelial cells with no staining of luminal cells, blood vessels, or stromal elements. The antigen survived prolonged enzymatic digestion of human breast tissue and could be demonstrated on myoepithelial cells in single-cell suspensions of human breast where it stained approximately 3-14% of the total cell population. The presence of this antigen on myoepithelial cells is discussed in the context of myoepithelial differentiation in the breast and the potential utility of the antibodies for cell separation.


Assuntos
Anticorpos Monoclonais , Antígenos de Neoplasias/análise , Neoplasias da Mama/patologia , Mama/citologia , Glândulas Mamárias Animais/citologia , Animais , Antígenos de Neoplasias/imunologia , Mama/imunologia , Neoplasias da Mama/imunologia , Diferenciação Celular , Células Epiteliais , Epitopos/análise , Feminino , Humanos , Glândulas Mamárias Animais/imunologia , Neprilisina , Gravidez , Ratos , Ratos Endogâmicos
8.
Cancer Res ; 49(24 Pt 1): 7010-4, 1989 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-2582442

RESUMO

The expression of the potent vasoactive peptide neuropeptide Y (NPY) was studied in 16 clinically and/or histologically diagnosed human pheochromocytomas and 3 human neuroblastoma tumors. All tumors contained NPY in concentrations ranging from 21 pmol/g of tissue, similar to that found in normal adrenal tissue, to 91,000 pmol/g (median, 1,700 pmol/g). Three control tumors of Cushing's type did not contain NPY. An almost total proteolytic processing of pro-NPY to normal NPY was observed in the tumors (median, 93%; range, 72-100%). A positive correlation between the processing efficiency and the NPY content was also observed. The small amount of pro-NPY found in the tumors was characterized by "in vitro conversion" with endoproteinase Lys-C. In the tumor extracts, the majority of the NPY immunoreactivity, corresponding in size to the NPY standard, also behaved like synthetic NPY by high performance liquid chromatography and isoelectric focusing. As assessed by both its elution position in isoelectric focusing and its reaction with an antiserum specific for the COOH-terminal amidated sequence, the peptide produced by the tumors was found to be efficiently amidated, a modification which is essential for the biological activity of NPY. It is concluded that although only a subset of chromaffin cells express NPY, a very high number of pheochromocytomas and neuroblastomas produce correctly amidated and thus biologically active NPY in large amounts, and that this is of potential importance for tumor-related cardiovascular symptoms and for autocrine stimulation of tumor cells.


Assuntos
Neoplasias das Glândulas Suprarrenais/metabolismo , Neuroblastoma/metabolismo , Neuropeptídeo Y/metabolismo , Feocromocitoma/metabolismo , Precursores de Proteínas/metabolismo , Adolescente , Córtex Suprarrenal/metabolismo , Adulto , Idoso , Criança , Pré-Escolar , Cromatografia em Gel , Cromatografia Líquida de Alta Pressão , Humanos , Focalização Isoelétrica , Masculino , Pessoa de Meia-Idade , Radioimunoensaio
9.
Cancer Res ; 49(24 Pt 1): 7015-9, 1989 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-2582443

RESUMO

The synthesis and processing of the precursor for neuropeptide Y (NPY) were studied in 16 human and murine neuroendocrine cell lines. Eight of the cell lines, NS-20Y, PC12, LA-N-5, CHP-234, SMS-KCNR, SH-SY5Y, SMS-KCN, and BE(2)-M17, produced sufficient quantities to permit chromatographic characterization of the NPY immunoreactivity. Although the cell lines varied in the amount of NPY they produced, both within and between cell lines, they displayed a relatively constant pattern of posttranslational modifications. In contrast to observations in tumor extracts (M. M. T. O'Hare and T. W. Schwartz, Cancer Res., 49: 7010-7014, 1989), all cell lines studied contained a substantial amount of the intracellular NPY in the form of the unprocessed propeptide, 57% (range, 33-72%) as characterized by both gel filtrations (32 experiments in 8 cell lines) and "in vitro conversion" with endoproteinase Lys-C. In the majority, 4 of 6 cell lines studied, almost all of the NPY, which by size corresponded to the mature 36-amino acid form, was amidated as assessed by isoelectric focusing and by a radioimmunoassay specific for the COOH-terminal amide group of the peptide. Both the propeptide and smaller molecular forms of NPY were secreted from the cell cultures; however, proteolytic degradation in the tissue culture medium prevented a detailed, meaningful characterization of these peptides. It is concluded that many neuroendocrine cell lines, especially those derived from human neuroblastomas, express the NPY gene; the cells display a partly impaired dibasic processing capacity but they generally amidate the products efficiently.


Assuntos
Neoplasias das Glândulas Suprarrenais/metabolismo , Neuroblastoma/metabolismo , Neuropeptídeo Y/metabolismo , Feocromocitoma/metabolismo , Precursores de Proteínas/metabolismo , Animais , Cromatografia em Gel , Cromatografia Líquida de Alta Pressão , Humanos , Focalização Isoelétrica , Camundongos , Processamento de Proteína Pós-Traducional , Radioimunoensaio , Células Tumorais Cultivadas
10.
Cancer Res ; 45(10): 5088-97, 1985 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-3896471

RESUMO

A recently established human breast carcinoma cell line has been reported to exhibit a number of morphological cell types in monolayer cultures as defined by phase-contrast microscopy. The cell line also produces cords of viable cells floating within the culture medium. Cultures of this cell line, grown in monolayer, on collagen gels, and as floating cords of cells, were studied by transmission electron microscopy and immunocytochemistry. A detailed analysis of the staining pattern obtained with a series of monoclonal antibodies with well-defined human breast epithelial cell specificities and a polyclonal antikeratin antibody showed PMC42 to resemble cultures of both normal human breast and other human breast carcinoma cell lines. The pleomorphic nature of PMC42 cultures was confirmed at an ultrastructural level, and of the eight cell types observed by phase-contrast appearance, seven ultrastructural counterparts were observed. In addition, the presence of intracytoplasmic lumina and overt epithelial differentiation confirm a breast epithelial origin for this cell line.


Assuntos
Neoplasias da Mama/patologia , Neoplasias da Mama/ultraestrutura , Linhagem Celular , Feminino , Imunofluorescência , Humanos , Microscopia Eletrônica , Microscopia de Contraste de Fase
11.
Cancer Res ; 46(8): 4217-20, 1986 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-3524802

RESUMO

We have devised a method utilizing a monoclonal antibody-toxin conjugate (LICR-LON-Fib75/abrin A-chain) for ridding bone marrow of infiltrating breast cancer cells to rescue patients with autologous bone marrow following high dose therapy. Initially we examined the activity of this conjugate in vitro. Five of seven human breast cancer cell lines were killed following exposure at 10(-8) M for 2 h; this concentration only reduced bone marrow colony formation to 83% (range, 50-100%) of control bone marrow. We then examined the pattern of bone marrow recovery after high dose melphalan (200 mg/m2) in patients with advanced breast cancer who were in remission following combination chemotherapy. To do this we compared the time of recovery of the blood count in three patients who received treated marrow and seven who received untreated marrow. Mean time to recovery of the peripheral white count (greater than 1.5 X 10(9)/liter) was 16.7 days (treated) and 18.3 days (untreated), respectively. Mean time to recovery of peripheral platelet count (greater than 50 X 10(9)/liter) was 23.7 days (treated) and 18.9 days (untreated), respectively. Patients continued in remission for 1-greater than 14 mo after high dose melphalan, and remission duration was similar in patients who received treated (6.2 mo) and untreated (7.3 mo) bone marrow. These findings indicate that treatment of bone marrow with LICR-LON-Fib75/abrin A-chain conjugate does not significantly impair bone marrow recovery, and it is, therefore, possible to rescue breast cancer patients with bone marrow that has been cleansed of infiltrating cancer cells. This may have an application in patients with poor-risk primary breast cancer who have micrometastases and who may benefit from intensive therapy, but it has minimal application in patients with more advanced disease.


Assuntos
Anticorpos Monoclonais/administração & dosagem , Transplante de Medula Óssea , Neoplasias da Mama/terapia , Abrina/administração & dosagem , Abrina/uso terapêutico , Anticorpos Monoclonais/uso terapêutico , Medula Óssea/efeitos dos fármacos , Medula Óssea/patologia , Linhagem Celular , Feminino , Humanos , Melfalan/uso terapêutico , Metástase Neoplásica , Ensaio Tumoral de Célula-Tronco
12.
Cancer Res ; 56(19): 4320-3, 1996 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-8813115

RESUMO

WNT-2 is a secreted polypeptide with mitogenic effects in murine mammary epithelial cells, but its role in human cancer is unknown. Using RNase protection analysis of primary cell preparations and in situ hybridization analysis, we report that WNT-2 is expressed at low levels in normal human breast fibroblasts but not in epithelial cells. WNT-2 was found to be expressed at high levels in both the epithelium and stroma of 5 of 11 infiltrating carcinomas and 2 of 6 fibroadenomas. The high level of WNT-2 expression in tumor epithelium suggests that tumorigenesis may involve the ectopic expression of WNT-2 and the creation of an autocrine Wnt signaling loop.


Assuntos
Neoplasias da Mama/genética , Mama/metabolismo , Carcinoma Ductal de Mama/genética , Fibroadenoma/genética , Regulação Neoplásica da Expressão Gênica , Proteínas de Neoplasias/biossíntese , Proteínas Proto-Oncogênicas/biossíntese , Mama/citologia , Neoplasias da Mama/patologia , Carcinoma Ductal de Mama/patologia , Tecido Conjuntivo/metabolismo , Epitélio/metabolismo , Feminino , Fibroadenoma/patologia , Fibroblastos/metabolismo , Humanos , Hibridização In Situ , Proteínas de Neoplasias/genética , Proteínas Proto-Oncogênicas/genética , Transdução de Sinais/fisiologia , Proteína Wnt2
13.
Cancer Res ; 60(8): 2232-8, 2000 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-10786689

RESUMO

A major objective of current cancer research is to develop a detailed molecular characterization of tumor cells and tissues that is linked to clinical information. Toward this end, we have identified approximately one-quarter of all genes that were aberrantly expressed in a breast cancer cell line using differential display. The cancer cells lost the expression of many genes involved in cell adhesion, communication, and maintenance of cell shape, while they gained the expression of many synthetic and metabolic enzymes important for cell proliferation. High-density, membrane-based hybridization arrays were used to study mRNA expression patterns of these genes in cultured cells and archived tumor tissue. Cluster analysis was then used to identify groups of genes, the expression patterns of which correlated with clinical information. Two clusters of genes, represented by p53 and maspin, had expression patterns that strongly associated with estrogen receptor status. A third cluster that included HSP-90 tended to be associated with clinical tumor stage, whereas a forth cluster that included keratin 14 tended to be associated with tumor size. Expression levels of these clinically relevant gene clusters allowed breast tumors to be grouped into distinct categories. Gene expression fingerprints that include these four gene clusters have the potential to improve prognostic accuracy and therapeutic outcomes for breast cancer patients.


Assuntos
Neoplasias da Mama/diagnóstico , Neoplasias da Mama/genética , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Adulto , Idoso , Idoso de 80 Anos ou mais , Neoplasias da Mama/patologia , Neoplasias da Mama/terapia , Genes Supressores de Tumor , Genes p53/genética , Proteínas de Choque Térmico HSP90/genética , Humanos , Queratinas/genética , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Análise de Sequência com Séries de Oligonucleotídeos , Prognóstico , Proteínas/genética , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Receptores de Estrogênio/fisiologia , Reprodutibilidade dos Testes , Serpinas/genética , Células Tumorais Cultivadas
15.
Oncogene ; 6(10): 1785-9, 1991 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-1717923

RESUMO

Using three antibodies (JG8, CM-1 and 1081) directed to the p53 protein, strong positivity was found in 16/47 (34.0%) of mucosal squamous cell carcinomas of the head and neck and in two squamous carcinoma cell lines (LICR-LON- HN5 and HN6Rr). The presence of the mutant p53 was confirmed in the cell lines as substitutions in exon 7 (codon 238, TGT greater than AGT) and exon 5 (codon 152, CCG greater than CTG) respectively. Positive staining was seen only in the undifferentiated cells and progressively lost as the cells keratinized, both in the tumour specimens and in the cell lines. Similar results were seen in areas of dysplasia, well removed from the site of the primary tumour. Staining of epidermal lesions showed positivity in 2/12 (16.6%) cases of Bowen's disease, 0/12 (0.0%) cases of solar keratosis, 0/10 (0.0%) basal cell carcinomas and in 3/20 (15.0%) squamous cell carcinomas. These results are discussed in relation to the multifocal origin of squamous cell carcinomas, the role of p53 mutations in squamous cell carcinomas from different sites and the significance of the 'basal' distribution of p53 as a normal growth regulator. The possible significance of the distribution of p53 in squamous epithelium as it relates to papilloma virus infection is also considered.


Assuntos
Carcinoma Basocelular/genética , Carcinoma de Células Escamosas/genética , Regulação Neoplásica da Expressão Gênica/genética , Genes p53/genética , Neoplasias Orofaríngeas/genética , Lesões Pré-Cancerosas/genética , Neoplasias Cutâneas/genética , Sequência de Aminoácidos , Linhagem Celular , Humanos , Dados de Sequência Molecular , Reação em Cadeia da Polimerase , Coloração e Rotulagem
16.
Biochim Biophys Acta ; 827(2): 127-34, 1985 Feb 04.
Artigo em Inglês | MEDLINE | ID: mdl-3967032

RESUMO

A method has been developed for the purification of cytosolic and mitochondrial isoenzymes of fumarase from total homogenates of pig liver. Separation of the isoenzymes from one another was achieved using chromatofocusing. The isoenzymes were pure as judged by production of single bands on electrophoresis in the presence of sodium dodecyl sulphate; they appeared to have identical or very similar subunit molecular weights. The isoenzymes differed in electrophoretic properties under nondenaturing conditions. One-dimensional peptide maps of fragments produced from the two isoenzymes by chemical cleavage at cysteine residues were identical; maps obtained after digestion with the V8 proteinase from Staphylococcus aureus showed small differences at short times of digestion which could have reflected variations in rates of hydrolysis rather than structural differences. However, two-dimensional peptide maps of digests obtained by treatment of the isoenzymes with trypsin followed by chymotrypsin had 58 peptides in common, but showed two peptides unique to the mitochondrial isoenzyme and five peptides unique to the cytosolic form. Using the dansylation procedure, the mitochondrial isoenzyme was shown to have N-terminal alanine and the cytosolic form to have N-terminal glutamic acid or glutamine. We conclude that the isoenzymes of fumarase are identical over nearly all of their amino acid sequences but differ at their N-termini; the extent of these differences is yet to be established. These results are consistent with the claim (Edwards, Y.H. and Hopkinson,D.A. (1979) Ann. Human Genet. Lond. 42, 303-313) that the isoenzymes are determined at the same genetic locus, but they raise interesting questions about the biosynthesis of the isoenzymes.


Assuntos
Fumarato Hidratase/isolamento & purificação , Isoenzimas/isolamento & purificação , Fígado/enzimologia , Mitocôndrias Hepáticas/enzimologia , Sequência de Aminoácidos , Animais , Compartimento Celular , Citosol/enzimologia , Eletroforese em Acetato de Celulose , Fragmentos de Peptídeos/análise , Suínos
17.
Biochim Biophys Acta ; 889(1): 49-58, 1986 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-3768428

RESUMO

Mammary explants from midpregnant rabbits were cultured for 18 h at 37 degrees C with insulin, prolactin and cortisol. Subsequently, explants were labelled for 2 h with inorganic [32P]phosphate, L-[5-3H]proline or L-[4,5-3H]leucine, washed and chased for up to 3 h. The radiolabelling profile of [32P]casein or [3H]casein during the chase period, obtained by isoelectric focussing or immunoprecipitation indicates extensive destruction of neosynthesized casein. The extent of casein destruction in mammary explants in culture (measured after radiolabelling with L-[5-3H]proline), is inversely related to casein secretion. Least casein degradation is observed in explants after 48 h in culture when casein secretion is maximal (observed histochemically). Subsequently, when the extracellular alveolar lumen is filled with secretion products (72 h), rapid intracellular casein destruction is again observed. When the chase was carried out in the presence of drugs which inhibit degradation and/or secretion, the results indicate that secretion-coupled casein degradation is dependent on an intact functional microfilamentous-microtubular network, casein is not degraded by an autophagosome requiring process, degradation is inhibited by leupeptin, amino-acid analogue containing casein does not undergo secretion-coupled degradation and inhibition of N-glycosylation of intracellular vesicular membrane proteins prevents secretion-coupled degradation. Secretion-coupled protein destruction is discussed in relation to the post-translational regulation of the net production of secretory proteins in eukaryotic cells.


Assuntos
Caseínas/metabolismo , Glândulas Mamárias Animais/metabolismo , Adenina/análogos & derivados , Adenina/farmacologia , Aminoácidos/farmacologia , Animais , Transporte Biológico , Colchicina/farmacologia , Citocalasina B/farmacologia , Feminino , Leupeptinas/farmacologia , Técnicas de Cultura de Órgãos , Coelhos , Tunicamicina/farmacologia
18.
Endocrinology ; 127(4): 1682-8, 1990 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-2205476

RESUMO

The present investigation provides three lines of evidence for the presence of a pro-form of neuropeptide Y (NPY) in plasma and follicular fluid. First, by the demonstration of NPY-immunoreactive material of a size corresponding to the estimated mol wt of pro-NPY. Second, an antiserum specific for the C-terminal tyrosine amide of NPY and peptide YY does not react with this material. Third, it was possible to convert the pro-NPY extracted from plasma and follicular fluid using the protease, Endoproteinase-Lys C, to a NPY-immunoreactive form eluting slightly before NPY on a G-50 column. The size of the digested product was consistent with a cleavage of pro-NPY resulting in an immunoreactive species, NPY-Gly-Lys. Pro-NPY was also found in tissue culture media from the human neuroendocrine cell line SH-SY5Y. As in the case of plasma and follicular fluid, another NPY immunoreactive species eluted from a G-50 gel filtration column slightly before synthetic human NPY. Analysis of this material with an antibody directed against the tyrosine amide of NPY in combination with isoelectric focusing revealed that this peak consisted of at least two immunoreactive forms of NPY. In conclusion, at least three different forms of NPY immunoreactivity are likely to be present in plasma, follicular fluid, and cell tissue culture media; pro-NPY, a degradation form of pro-NPY, or a biosynthetic intermediate and NPY.


Assuntos
Líquido Folicular/análise , Metaloendopeptidases , Neuropeptídeo Y/análise , Precursores de Proteínas/análise , Cromatografia em Gel , Endopeptidases/metabolismo , Feminino , Humanos , Masculino , Neuroblastoma , Neuropeptídeo Y/sangue , Neuropeptídeo Y/metabolismo , Ovário/análise , Precursores de Proteínas/sangue , Precursores de Proteínas/metabolismo , Células Tumorais Cultivadas
19.
Endocrinology ; 129(1): 553-5, 1991 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-2055204

RESUMO

Post-translational processing of peptide precursors producing amidated, biologically active peptides is generally believed to occur only in specially differentiated endocrine or neural cells. Previously it has been shown that endoproteolytic processing of peptide precursors is very inefficient in non-endocrine cells like CHO cells. We have studied the processing of a C-peptide-deleted precursor of neuropeptide Y (NPY) in which the precursor terminates in the sequence Gly-Lys-Arg and does not require any dibasic specific endoproteolytic processing. Following transfection of CHO cells with an expression plasmid encoding this mutated NPY precursor, between 50 and 80 percent of the synthesized NPY was secreted from stable transfectants as authentic amidated NPY as assessed by both a C-terminal amide specific radioimmunoassay and by isoelectric focusing. It is concluded that amidated peptides can be produced in non-endocrine cells provided they are presented with a precursor which does not have to be endoproteolytically processed.


Assuntos
Peptídeo C/genética , Neuropeptídeo Y/biossíntese , Precursores de Proteínas/metabolismo , Processamento de Proteína Pós-Traducional , Sequência de Aminoácidos , Animais , Linhagem Celular , Cricetinae , DNA/genética , Focalização Isoelétrica , Dados de Sequência Molecular , Mutagênese Sítio-Dirigida , Neuropeptídeo Y/genética , Plasmídeos , Precursores de Proteínas/genética , Transfecção
20.
Gene ; 111(2): 245-8, 1992 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-1311701

RESUMO

Porcine type-I collagenase (Colg-1) was produced as a fusion protein in Escherichia coli using the pAX5 expression vector. The fusion protein consists of beta-galactosidase at the N terminus joined to a collagen hinge region and a blood-coagulation factor Xa cleavage site linked to Colg-1. Recombinant collagenase (reColg-1) was biologically active in the form of a fusion protein and could be released by treatment with factor Xa to yield Colg-1 with the authentic N terminus (phenylalanine) found in vivo. The results show that reColg-1 produced in E. coli is folded correctly, cleaves type-I collagen into 1/4 and 3/4 fragments at the characteristic Colg-sensitive site, and is produced at high enough levels to generate a source of recombinant enzyme for x-ray crystallography studies.


Assuntos
Escherichia coli/genética , Colagenase Microbiana/genética , Suínos/genética , Sequência de Aminoácidos , Animais , Sequência de Bases , Western Blotting , Colágeno/metabolismo , Fator Xa/metabolismo , Vetores Genéticos/genética , Colagenase Microbiana/biossíntese , Colagenase Microbiana/metabolismo , Dados de Sequência Molecular , Plasmídeos/genética , Proteínas Recombinantes de Fusão/biossíntese , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo , beta-Galactosidase/genética , beta-Galactosidase/metabolismo
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