Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 27
Filtrar
1.
Tech Coloproctol ; 28(1): 130, 2024 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-39311960

RESUMO

BACKGROUND: Enhanced Recovery After Surgery (ERAS) has become increasingly popular in the post-operative management of abdominal surgery. Published data suggest that patients on ERAS protocols have fewer minor and major complications, and highlight a reduction in medical morbidity (such as urinary and respiratory infections). Limited data is available on surgical complications. The aim of the study was to evaluate the impact of the ERAS protocol on post-operative complications and length of hospital stay. Furthermore, we aimed to determine the impact of this protocol on cost-effectiveness. MATERIAL AND METHODS: From January 2016 to December 2022, 532 colectomies for colorectal cancer (CRC) were performed. A prospective observational study was conducted in a tertiary hospital on the cohort of patients, aged 18 years and older, operated on for non-urgent colorectal cancer. The impact on post-operative complications, hospital stay and economic impact was analysed in two groups: patients managed under ERAS and non-ERAS protocol. A propensity score-matching analysis was performed between the two groups. RESULTS: After propensity score matching 1:1, each cohort included 71 patients, and clinicopathological characteristics were well balanced in terms of tumour type, surgical technique and surgical approach. ERAS patients experienced fewer infectious complications and a shorter postoperative stay (p < 0.001). In particular, they had an 8.5% reduction in anastomotic dehiscence (p = 0.012) and surgical wound infections (p = 0.029). After analysis of medical complications, no statistically significant differences were identified in urinary tract infections, pneumonia, gastrointestinal bleeding or sepsis. ERAS protocol was more efficient and cost-effective than the control group, with an overall savings of 37,673.44€. CONCLUSIONS: The implementation of an enhanced recovery protocol for elective colorectal surgery in a tertiary hospital was cost-effective and associated with a reduction in post-operative complications, especially infectious complications.


Assuntos
Colectomia , Neoplasias Colorretais , Análise Custo-Benefício , Recuperação Pós-Cirúrgica Melhorada , Tempo de Internação , Complicações Pós-Operatórias , Pontuação de Propensão , Humanos , Feminino , Masculino , Neoplasias Colorretais/cirurgia , Neoplasias Colorretais/economia , Estudos Prospectivos , Tempo de Internação/estatística & dados numéricos , Tempo de Internação/economia , Pessoa de Meia-Idade , Complicações Pós-Operatórias/prevenção & controle , Complicações Pós-Operatórias/economia , Complicações Pós-Operatórias/etiologia , Idoso , Colectomia/economia , Colectomia/efeitos adversos , Colectomia/métodos , Protocolos Clínicos , Resultado do Tratamento
3.
Hernia ; 24(1): 93-98, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31494806

RESUMO

OBJECTIVES: The primary aim of this study was to identify the incisional hernia rate after temporary loop ileostomy closure. Secondary outcomes were determining the risk factors linked to this incisional hernia, which could improve the patient selection for mesh prophylaxis. METHODS: Retrospective cohort study of all consecutive patients with temporary loop ileostomy reversal through a peristomal incision from 1st January 2011 to 1st January 2017 at our centre. Data were extracted from electronic clinical records: baseline patient characteristics, surgical factors and postoperative events. CT scans performed during follow-up were precisely analysed. Survival analysis was applied to identify risk factors for hernia development. RESULTS: 129 patients were analysed of whom 15 (11.6%) developed an incisional hernia at previous ileostomy site. The median time for incisional hernia development was 11 months (IQR = 7-21) and the median follow-up time was 37 months (IQR = 22-57). The identified patient risk factors for hernia development in survival analysis were female sex, older age, higher Body Mass Index, clinically significant parastomal hernia, clinically detectable midline incisional hernia and major postoperative complications ranked as Clavien-Dindo grade III and IV. CONCLUSIONS: Incisional hernia after temporary loop ileostomy is a relevant problem that affects at least one in every ten patients. The previously cited risk factors might favour its development, therefore the use of a prophylactic mesh should be considered in those high-risk patients.


Assuntos
Ileostomia/efeitos adversos , Hérnia Incisional/epidemiologia , Hérnia Incisional/prevenção & controle , Complicações Pós-Operatórias/epidemiologia , Complicações Pós-Operatórias/prevenção & controle , Telas Cirúrgicas , Adulto , Idoso , Índice de Massa Corporal , Feminino , Humanos , Incidência , Masculino , Pessoa de Meia-Idade , Seleção de Pacientes , Estudos Retrospectivos , Fatores de Risco
4.
Clin Microbiol Infect ; 25(8): 973-980, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-30685500

RESUMO

OBJECTIVES: The aim was to investigate if offering symptomatic therapy (Uva-ursi or ibuprofen) alongside a delayed prescription would relieve symptoms and reduce the consumption of antibiotics for adult women presenting with acute uncomplicated urinary tract infection (UTI). METHODS: A 2 × 2 factorial placebo controlled randomized trial in primary care. The participants were 382 women aged 18-70 years with symptoms of dysuria, urgency, or frequency of urination and suspected by a clinician to have a lower UTI. The interventions were Uva-ursi extract and/or ibuprofen advice. All women were provided with a delayed or 'back-up' prescription for antibiotics. Missing data were imputed using multiple imputation methods (ISRCTN registry: ISRCTN43397016). RESULTS: An ITT analysis of mean score for frequency symptoms assessed on Days 2-4 found no evidence of a difference between Uva-ursi vs. placebo -0.06 (95% CI -0.33 to 0.21; p 0.661), nor ibuprofen vs. no ibuprofen advice -0.01 (95% CI -0.27 to 0.26; p 0.951). There was no evidence of a reduction in antibiotic consumption with Uva-ursi (39.9% vs. placebo 47.4%; logistic regression odds ratio (OR) 0.59 (95% CI 0.22-1.58; p 0.293) but there was a significant reduction for ibuprofen advice (34.9% vs. no advice 51.0%; OR 0.27 (95% CI 0.10 to 0.72; p 0.009). There were no safety concerns and no episodes of upper tract infection were recorded. CONCLUSIONS: We found no evidence of an effect of either intervention on the severity of frequency symptoms. There is evidence that advice to take ibuprofen will reduce antibiotic consumption without increasing complications. For every seven women given this advice, one less will use antibiotics.


Assuntos
Anti-Inflamatórios não Esteroides/uso terapêutico , Arctostaphylos/química , Terapias Complementares/métodos , Ibuprofeno/uso terapêutico , Extratos Vegetais/uso terapêutico , Infecções Urinárias/tratamento farmacológico , Doença Aguda/terapia , Adolescente , Adulto , Idoso , Método Duplo-Cego , Feminino , Humanos , Pessoa de Meia-Idade , Atenção Primária à Saúde , Resultado do Tratamento , Reino Unido , Adulto Jovem
5.
Colorectal Dis ; 10(6): 624-5, 2008 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-18215194

RESUMO

Massive low gastrointestinal bleedings are often difficult diagnostically and in terms of management. Sometimes, it is not possible to identify the bleeding point after performing diverse diagnostic tests and the patient undergoes a blind subtotal colectomy. With rectal bleeding, this form of surgery is completely useless, as it will not solve the cause of the haemorrhage. The Dieulafoy lesion has been widely described in the stomach, but in the rectum is a very rare entity that can cause massive lower gastrointestinal bleeding. In the literature, there are only 25 described cases of rectal Dieulafoy lesion.


Assuntos
Malformações Arteriovenosas/complicações , Hemorragia Gastrointestinal/etiologia , Reto/irrigação sanguínea , Colectomia , Humanos , Masculino , Pessoa de Meia-Idade
6.
Mol Cell Biol ; 2(3): 250-7, 1982 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-7110133

RESUMO

Resistance to adenine analogs such as 2,6-diaminopurine occurs at a rate of approximately 10(-3) per cell per generation in mouse L cells. This resistance is associated with a loss of detectable adenine phosphoribosyltransferase activity. Other genetic loci in L cells have the expected mutation frequency (approximately 10(-6)). Transformation of L cell mutants with Chinese hamster ovary cell DNA results in transformants with adenine phosphoribosyltransferase activity characteristic of Chinese hamster ovary cells. No activation of the mouse gene occurs on hybridization with human fibroblasts. That this high frequency event is the result of mutation rather than an epigenetic event is supported by antigenic and reversion studies of the 2,6-diaminopurine-resistant clones. These results are consistent with either a mutational hot-spot, a locus specific mutator gene, or a site of integration of an insertion sequence.


Assuntos
Adenina Fosforribosiltransferase/genética , Pentosiltransferases/genética , Adenina Fosforribosiltransferase/imunologia , Adenina Fosforribosiltransferase/metabolismo , Animais , Células Cultivadas , Células Clonais/enzimologia , Cricetinae , Cricetulus , Reações Cruzadas , Feminino , Regulação da Expressão Gênica , Genes , Humanos , Células Híbridas/enzimologia , Células L/enzimologia , Camundongos , Mutação , Ovário , Transformação Genética
7.
Curr Opin Biotechnol ; 6(5): 553-60, 1995 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-7579667

RESUMO

Recent advances in the generation of genetically engineered monoclonal antibodies have enhanced the importance of COS cells as expression systems for rapidly producing sufficient quantities of these proteins for preliminary biochemical and biophysical analysis. In order to meet the demand for clinical supplies, a gradual increase has occurred in the usage of dihydrofolate reductase negative (DHFR-) Chinese hamster ovary (CHO) cells for large-scale antibody production. Using a variety of mammalian expression vectors and selection/amplification protocols, CHO cell lines capable of producing monoclonal antibodies at levels exceeding 1 gl-1 can now be obtained in an almost routine fashion. For the applications of monoclonal antibodies to expand into additional therapeutic areas, however, a 5-10-fold increase over current highest expression levels may still need to be achieved.


Assuntos
Anticorpos Monoclonais/biossíntese , Células CHO/imunologia , Linhagem Celular , Animais , Cricetinae , Engenharia Genética , Haplorrinos , Rim
8.
Hernia ; 9(4): 375-7, 2005 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-15912261

RESUMO

We report the case of a white male who underwent a classic hemipelvectomy due to a femur fibrosarcoma with inguinal metastases, which 33 years later, developed into a posthemipelvectomy hernia in the amputation stump that impaired the use of his Canadian prosthesis. The hernia was repaired with a polypropylene mesh in a subaponeurotic position. A seroma was drained in the postoperative and it was only 2 months after the operation that he could use his prosthesis with any difficulty. A year after the operation, the hernia had not recurred. Only seven similar cases have been published, and there are only four cases with details of their correction, two with a mesh as was our case, and the rest with a primary suture of the aponeurotic borders. A brief review of the bibliography is given on this subject.


Assuntos
Hemipelvectomia , Hérnia/etiologia , Complicações Pós-Operatórias/etiologia , Neoplasias Femorais/cirurgia , Fibrossarcoma/cirurgia , Herniorrafia , Humanos , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias/cirurgia
9.
Gene ; 22(2-3): 219-28, 1983.
Artigo em Inglês | MEDLINE | ID: mdl-6307822

RESUMO

A functional mouse adenine phosphoribosyltransferase (APRT) gene was identified and cloned by screening a mouse sperm genomic DNA library in lambda Charon 4A. The probe utilized for screening was a restriction fragment encoding much of the hamster APRT gene. Six recombinants that hybridized with the probe were identified, and after digestion with restriction enzymes EcoRI and PvuII revealed three different patterns of digestion for each enzyme. Of the six recombinants, five representing two of the restriction patterns possessed transforming activity. A sixth recombinant, which has a unique restriction pattern, lacks transforming activity but hybridizes well with hamster APRT coding sequences and is a possible candidate for a pseudogene. We used three criteria for conclusively identifying the mouse APRT genes. (1) DNA from the recombinant lambda phage hybridizes with DNA encoding hamster APRT. (2) The recombinant lambda phages and their DNAs transform mouse, hamster and human APRT- cells to the APRT+ phenotype. (3) The hamster and human transformants display APRT activity that migrates with a mobility characteristic of mouse APRT and not of hamster or human. A 3.1-kb EcoRI-SphI restriction fragment which retains transforming activity has been subcloned into the plasmid pBR328. Comparison of restriction enzyme sites with those contained in a mouse APRT cDNA, coupled with loss of transforming activity after enzyme digestion, indicates that the mouse APRT gene is larger than 1.8 kb and contains at least three introns.


Assuntos
Adenina Fosforribosiltransferase/genética , Clonagem Molecular , DNA Recombinante/metabolismo , Genes , Pentosiltransferases/genética , Animais , Sequência de Bases , DNA/análise , Enzimas de Restrição do DNA , Masculino , Camundongos , Hibridização de Ácido Nucleico , Espermatozoides/enzimologia
10.
J Steroid Biochem Mol Biol ; 52(4): 307-19, 1995 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-7734398

RESUMO

The Cynomolgus monkey may provide an alternative pharmacological model in which to evaluate the efficacy of novel inhibitors of the two known human steroid 5 alpha-reductase (SR) isoenzymes. To evaluate the suitability of this species at the level of the molecular targets, a Cynomolgus monkey prostate cDNA library was prepared and screened using human SR type 1 and 2 cDNAs as hybridization probes. Two distinct cDNA sequences were isolated encoding the monkey type 1 and 2 SR isoenzymes. These sequences share 93 and 95% amino acid sequence identity with their human enzyme counterparts, respectively. Difference in monkey type 1 SR, however, was found within the contiguous four amino acids corresponding to the regions in the human and rat sequences that have been proposed previously to influence steroid and inhibitor affinities. Subsequently, both monkey cDNAs were individually expressed in a mammalian cell (CHO) line. Enzyme activities of both monkey SRs were localized to the membrane fractions of CHO cell extracts. Like the human and rat enzymes, the monkey type 1 and type 2 SRs were most active at neutral and low pH, respectively. The results of inhibition studies with over 30 known SR inhibitors, including epristeride, 4MA, and finasteride, indicate that the monkey SR isoenzymes are functionally more similar to the human than the rat homologues. The results from initial velocity and inhibition studies as functions of pH with the human and monkey type 2 SRs also compare favorably. These results, together, suggest that the monkey SR isoenzymes are structurally and functionally comparable on a molecular level to their respective human counterparts, supporting the relevance and use of the Cynomolgus monkey as a pharmacological model for in vivo evaluation of SR inhibitors.


Assuntos
3-Oxo-5-alfa-Esteroide 4-Desidrogenase/genética , Isoenzimas/genética , Próstata/enzimologia , Esteroides/metabolismo , 3-Oxo-5-alfa-Esteroide 4-Desidrogenase/classificação , 3-Oxo-5-alfa-Esteroide 4-Desidrogenase/metabolismo , Inibidores de 5-alfa Redutase , Sequência de Aminoácidos , Animais , Sequência de Bases , Northern Blotting , Clonagem Molecular , DNA Complementar/genética , Expressão Gênica , Humanos , Concentração de Íons de Hidrogênio , Macaca fascicularis , Masculino , Dados de Sequência Molecular , RNA Mensageiro/genética , Ratos , Proteínas Recombinantes/metabolismo , Análise de Sequência de DNA , Homologia de Sequência de Aminoácidos
11.
Transplant Proc ; 43(3): 755-7, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21486592

RESUMO

We report a 66-year-old woman who underwent emergency orthotopic liver transplantation due to acute liver failure. The donor's liver graft displayed extensive arteriosclerosis, involving the celiac trunk and hepatic artery. Arterial revascularization of the graft could not be achieved, requiring an arterioportal shunt between the gastroduodenal artery and the portal vein of the recipient. During the early postoperative period, the patient's clinical condition and liver function tests improved rapidly; the patient was discharged on postoperative day 30. Two months later, she developed acute cholangitis. Ischemic-type stenosis of the intrahepatic biliary tree was present, so successful elective retransplantation was undertaken at the ninth postoperative month. In our experience, portal vein arterialization may be useful as a bridging therapy in extreme situations.


Assuntos
Artéria Hepática/fisiopatologia , Transplante de Fígado , Veia Porta/fisiopatologia , Idoso , Feminino , Humanos
13.
Somat Cell Mol Genet ; 10(4): 359-67, 1984 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-6087472

RESUMO

A complete human APRT gene has been isolated from a lambda phage genomic library using cloned mouse APRT DNA as a probe. The human gene, contained in a recombinant lambda phage designated lambda Huap15, is functional by virtue of its capacity to transfer human APRT activity to Aprt- mouse recipient cells after phage-mediated transfection. Digestion of lambda Huap15 DNA with BamH1 generated a 2.2-kb fragment that is the only fragment of eight produced to hybridize with the mouse APRT gene. This 2.2-kb BamH1 fragment is a unique, single copy sequence, and has been used to identify a restriction fragment length polymorphism (RFLP) associated with the APRT locus. Taq1 digestion and Southern blot analysis of DNAs from 49 unrelated individuals produced three different patterns. DNAs of 30 individuals produced a restriction pattern of three labeled fragments about 500 bp, 600 bp, and 2.1 kb in size, which is characteristic for individuals homozygous for the more common allele. Two individuals homozygous for the less frequent allele displayed labeled fragments of 500 bp and 2.7 kb. The remaining 17 DNA samples produced all four labeled bands as expected for heterozygous individuals. The frequency of heterozygotes in the population is about 35%, while the frequency of the less common allele is about 0.21. Restriction enzyme analysis of DNAs from two APRT-deficient brothers and from an unrelated heterozygote revealed no gross deletions or rearrangements, nor the Taq1 polymorphism.


Assuntos
Adenina Fosforribosiltransferase/genética , Pentosiltransferases/genética , Adenina Fosforribosiltransferase/deficiência , Clonagem Molecular , Enzimas de Restrição do DNA , Genes , Heterozigoto , Humanos , Polimorfismo Genético
14.
Cytogenet Cell Genet ; 38(3): 227-34, 1984.
Artigo em Inglês | MEDLINE | ID: mdl-6237889

RESUMO

Transfection of mammalian cells with genomic DNA and cloned genes is now relatively routine. However, the vast majority of studies have used rodent cells as recipients. Here we describe efficient transfection of two human cell lines, the hypoxanthine guanine phosphoribosyltransferase (HPRT)-deficient HeLa line, D98/AH-2, and the adenine phosphoribosyltransferase (APRT)-deficient HT1080 line, HTD114. D98/AH-2 cells were transfected with the pSV2-gpt plasmid of Mulligan and Berg, which contains the E. coli xanthine-guanine phosphoribosyltransferase (gpt) gene, and Gpt + transfectants were selected in HAT medium. HTD114 cells were transfected with (1) genomic hamster DNA, and ouabain resistant transfectants were selected in 5 X 10(-7)M ouabain; (2) with hamster and mouse genomic DNA, and Aprt + cells were selected in AAA medium; (3) with plasmids containing either the cloned hamster or mouse APRT genes, and Aprt + cells were selected; and (4) with phage particles containing a cloned mouse APRT gene, and Aprt + cells were selected. Transfection efficiencies ranged from 0.25 to 1.5 X 10(3) transfectants per microgram DNA, and in certain cases secondary transfections were done. Foreign DNA in recipients was detected by blot hybridization, and the expression of foreign genes was detected by cell growth in selective media and the expression of enzymes characteristic of the species of the donor DNA. The majority of transfectants showed stable expression of the transgenome.


Assuntos
Bacteriófago lambda/genética , DNA/genética , Escherichia coli/genética , Regulação da Expressão Gênica , Genes , Plasmídeos , Transfecção , Animais , Linhagem Celular , Células Cultivadas , Clonagem Molecular , Cricetinae , DNA Bacteriano/genética , DNA Viral/genética , Genes Bacterianos , Genes Virais , Marcadores Genéticos , Humanos , Camundongos , Hibridização de Ácido Nucleico
15.
Am J Obstet Gynecol ; 154(4): 737-48, 1986 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-3008557

RESUMO

Four experiments evaluated the sensitivity and specificity of molecular techniques to detect human Y chromosome deoxyribonucleic acid. In experiment I, electrophoretic separation of normal male deoxyribonucleic acid fragments after digestion with endonuclease Hae III revealed two male-specific bands of 3.4 and 2.1 kilobase (kb). These bands were not visible if the fraction of male deoxyribonucleic acid in mixed samples was less than 0.3. In experiment II, by means of a repetitive copy Y deoxyribonucleic acid probe (pS4) mapped to Yq12, a male-specific 2.3 kb band was detectable in mixtures of 2.5 ng of male deoxyribonucleic acid and 997.5 ng of 45,X female deoxyribonucleic acid. In experiment III, hybridization with the pS4 probe was performed on the deoxyribonucleic acid of 20 subjects with a normal or a variant Y chromosome. In experiment IV, deoxyribonucleic acid from the same subjects was hybridized to a single copy probe (4B-2) mapped to the Yq11 region. Deoxyribonucleic acid from category A subjects (n = 8) with cytologically normal Y chromosomes hybridized to both deoxyribonucleic acid probes. Deoxyribonucleic acid from category B subjects (n = 2), including a variant Y chromosome that was negative for Q-banding but positive for C-bands, hybridized with the distal pS4 and proximal 4B-2 probes. Deoxyribonucleic acid from category C subjects (n = 10) with variant Y chromosomes uniformly negative for Q- and C-bands, did not hybridize with the pS4 probe. Deoxyribonucleic acid from three of the 10 category C subjects did hybridize to the more proximal sequence-detecting 4B-2 probe. Deoxyribonucleic acid from the remaining seven subjects in category C did not hybridize with either of the deoxyribonucleic acid probes.


Assuntos
DNA/análise , Desoxirribonucleases de Sítio Específico do Tipo II , Aberrações dos Cromossomos Sexuais/diagnóstico , Cromossomo Y/análise , Adolescente , Adulto , Criança , Pré-Escolar , Bandeamento Cromossômico/métodos , DNA/isolamento & purificação , Enzimas de Restrição do DNA/farmacologia , Eletroforese em Gel de Poliacrilamida , Escherichia coli/genética , Feminino , Humanos , Lactente , Cariotipagem , Masculino , Mosaicismo , Hibridização de Ácido Nucleico , Fenótipo , Plasmídeos , Sequências Repetitivas de Ácido Nucleico , Caracteres Sexuais
16.
J Exp Pathol ; 2(4): 299-311, 1986.
Artigo em Inglês | MEDLINE | ID: mdl-3783283

RESUMO

Three multipotent mouse teratocarcinoma stem lines, all exhibiting unstable expression for the purine salvage enzyme adenine phosphoribosyltransferase (APRT) were used for the isolation of differentiated cell lines from neoplasms developed in syngeneic mice. Two of the stem cell lines (DAP1B and DAP1C) exhibited homozygous deficiencies for APRT expression while the third stem cell line (E140) exhibited a heterozygous deficiency (Turker, M.S., Smith, A.C., and Martin, G.M.; Somat. Cell Mol. Genet.; 10:55-69; 1984). A total of 16 morphologically differentiated cell lines were established from these neoplasms; most were no longer tumorigenic. Differentiated cell lines derived from the E140-induced tumors segregated homozygous deficient mutants in a single step, consistent with their retention of the heterozygous deficient state. Differentiated homozygous deficient cell lines gave rise to phenotypic revertants at very high frequencies (10(-1) to 10(-2)). The majority of these putative revertants, however, yielded cell-free extracts with little or no detectable APRT activity. These putative revertants were capable of adenine salvage and were therefore termed APRT pseudorevertants. Since the APRT pseudorevertant phenotype was only observed in the differentiated progeny of the APRT deficient stem cell lines, we conclude that this change in the nature of the revertant phenotype was a consequence of cellular differentiation.


Assuntos
Adenina Fosforribosiltransferase/metabolismo , Pentosiltransferases/metabolismo , Teratoma/enzimologia , Adenina/metabolismo , Adenina Fosforribosiltransferase/genética , Animais , Diferenciação Celular , Linhagem Celular , DNA de Neoplasias/análise , Camundongos , Transplante de Neoplasias , Fenótipo , Transplante Isogênico
17.
Proc Natl Acad Sci U S A ; 83(2): 384-8, 1986 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-2934742

RESUMO

When 32P-labeled human recombinant immune interferon gamma (Hu-[32P]IFN-gamma) is crosslinked to human cells with disuccinimidyl suberate, a complex with a molecular size of approximately equal to 117,000 Da was identified by sodium dodecyl sulfate/polyacrylamide gel electrophoresis. The formation of this complex is inhibited when the binding is performed in the presence of excess unlabeled Hu-IFN-gamma. The specific formation of the 117,000-Da complex is not observed in mouse L cells or Chinese hamster ovary cells. This complex shows all of the criteria that identify it as the Hu-IFN-gamma receptor or its binding subunit. The same complex can be formed following binding and covalent crosslinking of Hu-[32P]IFN-gamma to some hamster-human or mouse-human somatic cell hybrids. The presence of human chromosome 6 in the hybrids is necessary and sufficient for the formation of this complex. More specifically, the long arm of chromosome 6 seems sufficient. Therefore, we have localized the gene for the Hu-IFN-gamma receptor (or its binding subunit) to the long arm of human chromosome 6. The presence of this chromosome in the somatic cell hybrids is not adequate, however, to confer antiviral resistance to the hybrids in the presence of Hu-IFN-gamma.


Assuntos
Cromossomos Humanos 6-12 e X , Interferon gama/metabolismo , Receptores Imunológicos/genética , Bioensaio , Linhagem Celular , Mapeamento Cromossômico , Efeito Citopatogênico Viral , Humanos , Células Híbridas , Receptores de Interferon
18.
Mol Cell Biochem ; 131(1): 75-86, 1994 Feb 09.
Artigo em Inglês | MEDLINE | ID: mdl-8047068

RESUMO

To address conflicting reports concerning the number of angiotensin II (AII) receptor type 1 (AT1) coding loci in vertebrates, Southern blot analysis was used to determine the genomic representation of AT1 receptor genes in animals comprising a divergent evolutionary spectrum. The data demonstrate that the AT1 receptor gene is present as a single genomic copy in a broad spectrum of animals including human, monkey, dog, cow, rabbit, and chicken. In contrast, members of the rodent taxonomic order contain two genes in their genomes. These two genes may have arisen in rodents as a consequence of a gene duplication event that occurred during evolution following the branching of rodents from the mammalian phylogenetic tree. In order to investigate the properties of the human AT1 receptor in a pure cell system, the recombinant human AT1 receptor was stably expressed in mouse L cells. An isolated cell line, designated LhAT1-D6, was found to express abundant levels of recombinant receptor [430 +/- 15 fmol/mg] exhibiting high affinity [KD = 0.15 +/- 0.02 nM] for [125I][SAR1, Ile8] angiotensin II (SIA). The pharmacological profile of ligands competing for [125I] SIA binding to the expressed receptor was in accordance with that of the natural receptor. Radioligand binding of the expressed receptor was decreased in the presence of the non-hydrolyzable analog of GTP, guanosine 5'-(gamma-thio) triphosphate [GTP gamma S]. Angiotensin II evoked a rapid efflux of 45Ca2+ from LhAT1-D6 cells that was blocked by AT1 receptor specific antagonists. In addition, AII inhibited forskolin-stimulated cAMP accumulation in these cells which was blocked by the AT-1 antagonist. Thus, the LhAT1-D6 cell line provides a powerful tool to explore the human AT1 receptor regulation.


Assuntos
Código Genético , Genoma Humano , Receptores de Angiotensina/genética , Animais , Ligação Competitiva/efeitos dos fármacos , Linhagem Celular , Mapeamento Cromossômico , Colforsina/farmacologia , Proteínas de Ligação ao GTP/metabolismo , Expressão Gênica , Humanos , Camundongos , Ensaio Radioligante , Receptores de Angiotensina/metabolismo , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Especificidade da Espécie
19.
DNA ; 7(9): 651-61, 1988 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-3147883

RESUMO

High-level expression of human tissue-type plasminogen activator was accomplished in endothelial cells by a novel approach to dihydrofolate reductase (DHFR) coamplification in DHFR+ cells. A tripartite mammalian expression vector coding for DHFR, neomycin phosphotransferase, and the t-PA gene was introduced into bovine endothelial cells by transfection and selection for G418 resistance. Upon methotrexate selection of these transformants, we obtained endothelial cells that had amplified the plasmid-encoded DHFR and t-PA genes. As a result, cell lines were isolated that efficiently produced t-PA (greater than 4 pg/cell.day). This t-PA was purified and compared with recombinant t-PA produced in Chinese hamster ovary cells. These two t-PA samples differed in carbohydrate composition, and amounts of 530 and 527 amino acid forms but had similar in vitro activity.


Assuntos
Técnicas de Amplificação de Ácido Nucleico , Tetra-Hidrofolato Desidrogenase/biossíntese , Ativador de Plasminogênio Tecidual/biossíntese , Animais , Bovinos , Linhagem Celular , Vetores Genéticos , Humanos , Plasmídeos , Tetra-Hidrofolato Desidrogenase/genética , Ativador de Plasminogênio Tecidual/genética , Ativador de Plasminogênio Tecidual/isolamento & purificação
20.
J Biol Chem ; 276(20): 16739-48, 2001 May 18.
Artigo em Inglês | MEDLINE | ID: mdl-11278492

RESUMO

Amyloid 39-42 beta -peptides are the main components of amyloid plaques found in the brain of Alzheimer's disease patients. Amyloid 39-42 beta-peptide is formed from amyloid precursor protein by the sequential action of beta- and gamma-secretases. Asp-2 is a transmembrane aspartic protease expressed in the brain, shown to have beta-secretase activity. Mature Asp-2 has four N-glycosylation sites. In this report we have characterized the carbohydrate structures in this glycoprotein expressed in three different cell lines, namely Chinese hamster ovary, CV-1 origin of SV40, and baculovirus-infected SF9 cells. Biantennary and triantennary oligosaccharides of the "complex" type were released from glycoprotein expressed in the mammalian cells, whereas mannose-rich glycans were identified from glycoprotein synthesized in the baculovirus-infected cells. Site-directed mutagenesis of the asparagine residues at amino acid positions 153, 172, 223, and 354 demonstrate that the protease activity of Asp-2 is dependent on its glycosylation.


Assuntos
Doença de Alzheimer/enzimologia , Ácido Aspártico Endopeptidases/química , Ácido Aspártico Endopeptidases/metabolismo , Glicoproteínas/metabolismo , Oligossacarídeos/química , Polissacarídeos/metabolismo , Secretases da Proteína Precursora do Amiloide , Animais , Ácido Aspártico Endopeptidases/genética , Encéfalo/enzimologia , Células CHO , Configuração de Carboidratos , Sequência de Carboidratos , Linhagem Celular , Cricetinae , Endopeptidases , Glicoproteínas/química , Glicoproteínas/genética , Glicosilação , Humanos , Dados de Sequência Molecular , Polissacarídeos/química , Proteínas Recombinantes/química , Proteínas Recombinantes/metabolismo , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz , Spodoptera , Transfecção
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA