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1.
New Microbes New Infect ; 24: 52-55, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29872531

RESUMO

Human coronaviruses (CoVs) are increasingly recognized as important respiratory pathogens associated with a broad range of clinical diseases. We sought to increase the insight into clinically relevant CoV infections by monitoring antigen concentrations in six confirmed CoV-positive patients using a newly developed assay for rapid detection of CoV OC43 infections. Antigen positivity lasted 3 to 6 days in secondary infections and 13 days in primary infection. CoV infections are clinically diverse, are common, and cannot be diagnosed from clinical symptoms alone.

2.
New Microbes New Infect ; 11: 17-9, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-27014463

RESUMO

Clinically relevant diagnosis of human bocavirus 1 (HBoV1) is challenging, as the virus is frequently detected in asymptomatic patients, and cofindings with other respiratory viruses are common. The clinical value of current diagnostic methods, such as PCR, is therefore low, and alternative diagnostic strategies are needed. We describe for the first time the use of an antigen detection assay for the rapid identification of HBoV1 in a paediatric patient with respiratory tract infection symptoms. We estimate the duration of active HBoV1 infection to be 6 days.

3.
Clin Microbiol Infect ; 22(12): 1002.e9-1002.e14, 2016 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-27554204

RESUMO

Rhinoviruses (RVs) are frequently detected respiratory viruses that cause mild common cold symptoms, but may also lead to more severe respiratory tract infections. The large number of RV types, classified into species A, B and C, hampers clear insights into the epidemiology and clinical significance of each RV type. The aim of this study was to map the circulation of RV types in the Amsterdam area. RV-positive nasopharyngeal and oropharyngeal samples, collected from 2007 to 2012 in the Academic Medical Centre (Amsterdam, the Netherlands), were typed based on the sequence of the region coding for capsid proteins VP4 and VP2. RV-A, RV-B and RV-C were found in proportions of of 52.4% (334/637), 11.3% (72/637), and 36.2% (231/637), respectively. We detected 129 of the 167 currently classified types. RVs circulated throughout the entire year with a peak in the autumn and a decline in the summer. Some RV types were observed throughout the entire sampling period and others had a more seasonal pattern. Nine RV-A and four RV-B novel provisionally assigned types were identified. This study provides an insight into the molecular epidemiology of RVs in the Amsterdam area. The RVs circulating are diverse and include several provisionally new types.


Assuntos
Proteínas do Capsídeo/genética , Resfriado Comum/epidemiologia , Rhinovirus/genética , Rhinovirus/isolamento & purificação , Resfriado Comum/virologia , Técnicas de Genotipagem , Humanos , Epidemiologia Molecular , Nasofaringe/virologia , Países Baixos/epidemiologia , RNA Viral/isolamento & purificação , Rhinovirus/classificação , Estações do Ano , Análise de Sequência de DNA
4.
Hum Gene Ther ; 12(4): 391-9, 2001 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-11242531

RESUMO

Recombinant adenoviruses expressing a therapeutic gene are currently used in clinical studies for treatment of advanced ovarian cancer. We therefore tested whether the expression level of primary (CAR) and secondary adenovirus receptors (integrins) was predictive of the efficacy of adenoviral gene transfer in ovarian cancer cells. Adenoviral transduction efficiency (ATE) was determined with an E1-deleted adenovirus type 5 expressing beta-galactosidase under a CMV promoter (AdGal). ATE was studied in relationship to the expression level of both CAR (coxsackie and adenovirus receptor) and integrins. A representative sample of 25 permanent human cell lines established from advanced ovarian cancer in our laboratory and the OV-2774 cell line were tested. Overall, ATE increased with increasing titers of AdGal. At a given titer of 50 infectious units per cell, transduction efficiency varied from 6 to 94% among the individual cell lines. All cell lines expressed CAR and integrin alpha(v)beta(5), but no relation between ATE and expression level of CAR or alpha(v)beta(5) integrin was observed. In contrast, cell lines with poor ATE, despite expressing high levels of CAR, lacked expression of integrins alpha(v)beta(3) and alpha(5)beta(1). Reconstitution of alpha(v)beta(3) integrin by reexpressing the beta(3) subunit significantly enhanced ATE of ovarian cancer cells. In ovarian cancer, neither integrins nor CAR alone appear to be potentially useful predictive markers for ATE by serotype 5 adenovirus in clinical gene therapy. A minimum level of CAR necessary for binding of adenoviruses was observed in all tested ovarian cancer cell lines. Loss of alpha(v)beta(3) integrin is frequently associated with advanced stages of ovarian cancer and can significantly reduce ATE.


Assuntos
Adenoviridae/genética , Antígenos CD/biossíntese , Integrinas/análise , Neoplasias Ovarianas/metabolismo , Glicoproteínas da Membrana de Plaquetas/biossíntese , Receptores de Vitronectina/metabolismo , Transdução Genética , Antígenos CD/genética , Western Blotting , Membrana Celular/metabolismo , Proteína de Membrana Semelhante a Receptor de Coxsackie e Adenovirus , Primers do DNA/química , Feminino , Citometria de Fluxo , Expressão Gênica , Vetores Genéticos , Humanos , Integrina beta3 , Proteínas de Neoplasias/análise , Glicoproteínas da Membrana de Plaquetas/genética , RNA Mensageiro/análise , Receptores Virais/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Células Tumorais Cultivadas , beta-Galactosidase/genética , beta-Galactosidase/metabolismo
5.
J Histochem Cytochem ; 42(7): 917-29, 1994 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-8014475

RESUMO

We investigated the appearance and activity of the cysteine proteinase cathepsin B and its physiological inhibitors, stefins A and B, at the cellular level in human tumor cell lines HS-24, derived from a primary lung tumor (squamous cell), and SB-3, derived from a metastasis (lung adenocarcinoma). In addition to cathepsin B, these tumor cells also expressed the immunologically and functionally related cathepsin L, but not cathepsin H. Stefin A was found in HS-24 but not in SB-3 cells; stefin B was found in both cell types. Using a specific fluorogenic cytochemical assay, the intracellular activity of the enzyme was localized and quantified. Thus, the cellular cathepsin B kinetics for the synthetic substrates Z-Arg-Arg-4M beta NA and Z-Val-Lys-Lys-Arg-4M beta NA, its pH dependence and inhibition by E64, stefins A and B, and cystatin C could be determined. From these measurements it appeared that the enzyme exhibited different cleavage rates for these substrates in the different cell types, showed considerable cleavage activity at neutral pH, which was stable under these conditions for extended time periods, and was highly sensitive to the inhibitors E64 and cystatin C but was considerably less sensitive to stefins, particularly stefin A. By conventional light microscopy, confocal laser scanning microscopy, and electron microscopy the enzymatic activity was localized in lysosomes, as expected, but also in the endoplasmic reticulum, nuclear membrane, and plasma membrane. The endoplasmic reticulum is a site at which only pre-mature enzyme forms exist, which are usually not active. The appearance of enzymatic activity at the plasma membrane confirms earlier biochemical and immunofluorescence microscopic investigations. The different sites of localization within the cells make it likely that different forms of the enzyme are expressed simultaneously, which follow alternate ways of processing and sorting. Taken together, the results support an involvement of the enzyme under extracellular conditions in degradative processes.


Assuntos
Catepsina B/metabolismo , Inibidores de Cisteína Proteinase/metabolismo , Neoplasias Pulmonares/enzimologia , Sequência de Aminoácidos , Carcinoma Pulmonar de Células não Pequenas/enzimologia , Catepsina B/antagonistas & inibidores , Células Cultivadas , Cistatina B , Cistatinas/metabolismo , Humanos , Concentração de Íons de Hidrogênio , Cinética , Pulmão/enzimologia , Neoplasias Pulmonares/ultraestrutura , Microscopia/métodos , Microscopia Eletrônica , Dados de Sequência Molecular , Células Tumorais Cultivadas
6.
Am J Med Genet ; 63(3): 419-25, 1996 Jun 14.
Artigo em Inglês | MEDLINE | ID: mdl-8737645

RESUMO

To identify, contact, and offer free cystic fibrosis (CF) carrier education, testing, and genetic counseling to the first, second, and third degree relatives of individuals with CF, study personnel contacted probands or the parents of minor probands requesting assistance in identifying relatives. We requested family pedigrees, including names, addresses, and phone numbers and if necessary a saliva sample for determination of the specific CF mutations in the family. Two hundred three families of 220 probands being followed at a large CF clinic in the Southeastern United States were eligible for inclusion in the study. Of the 203 families 109 (53.7%) assisted by providing contact information on relatives and, when necessary, a saliva sample for mutation analysis. An additional 33 (16.4%) agreed to assist but did not provide either or both contact information or saliva samples. Sixty-one (30.1%) declined to provide assistance. Thirteen percent of the probands/parents wanted to talk with relatives before providing contact information. A logistic regression model predicting proband/parent assistance is provided. This study suggests that the active outreach method used here to identify at risk relatives to offer them CF carrier testing resulted in somewhat lower proband or parent assistance than reported by other similar approaches. The strengths and weaknesses of this approach, including comments by probands and parents on the method, are discussed.


Assuntos
Fibrose Cística/genética , Aconselhamento Genético/estatística & dados numéricos , Heterozigoto , Adolescente , Adulto , Atitude Frente a Saúde , Criança , Pré-Escolar , Fibrose Cística/diagnóstico , Fibrose Cística/epidemiologia , Análise Mutacional de DNA , Feminino , Humanos , Lactente , Masculino , Modelos Teóricos , Análise Multivariada , Linhagem , Análise de Regressão , Saliva/fisiologia , Fatores de Tempo
7.
Aliment Pharmacol Ther ; 13(8): 1119-29, 1999 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-10468691

RESUMO

BACKGROUND: Octreotide is a potent splanchnic hypotensive somatostatin analogue effective in the treatment of acute variceal bleeding. AIM: To study the effects of octreotide on basal and postprandial splanchnic and systemic haemodynamics, and hormonal changes in humans. METHODS: Twenty-four healthy volunteers were randomized to receive a liquid meal and either octreotide (OCT, 100 microg bolus) or placebo repeatedly every 4 h for 48 h. Splanchnic (Doppler ultrasound) and systemic haemodynamics (non-invasive cardiac monitoring) were assessed for 2 h on four consecutive days: one control day and after doses 1 (0 h), 7 (24 h) and 13 (48 h). RESULTS: The maximum postprandial increases in mean blood velocity of the superior mesenteric artery (SMA-Vmean +72%), portal (PBF +52%) and total hepatic blood flow (HBF +50%) observed in the placebo group, were abolished after the first dose of octreotide (SMA-Vmean -23%, P<0.01; PBF -22%, P<0.01; HBF -21%, P<0.01). Postprandial hyperemia was restored at the end of the 48-h study period, but baseline SMA-Vmean (placebo 40+/-12, OCT 29+/-11 cm/s, P<0.05) and PBF (placebo 1200+/-971, OCT 743+/-449 mL/min, P<0.05) remained significantly lower in the octreotide group. The postprandial decrease of systemic vascular resistance and increase of cardiac index were prevented by octreotide for 48 h. CONCLUSIONS: Repeated 4-hourly bolus injections of octreotide reduce splanchnic blood flow for at least 48 h, but the prevention of food-induced splanchnic hyperemia is short-lasting.


Assuntos
Fármacos Gastrointestinais/farmacologia , Hemodinâmica/efeitos dos fármacos , Hiperemia/diagnóstico por imagem , Octreotida/farmacologia , Período Pós-Prandial/fisiologia , Circulação Esplâncnica/efeitos dos fármacos , Adulto , Glicemia/metabolismo , Feminino , Artéria Hepática/efeitos dos fármacos , Hormônios/sangue , Humanos , Hiperemia/fisiopatologia , Masculino , Artéria Mesentérica Superior/efeitos dos fármacos , Veia Porta/efeitos dos fármacos , Ultrassonografia
8.
J Virol Methods ; 81(1-2): 143-54, 1999 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-10488772

RESUMO

Rinderpest is a contagious viral disease of cloven-hoofed domestic and wild animals. Eradication of the virus following outbreaks depends on rapid and accurate diagnosis of infection and the implementation of control measures. Reporting and confirmatory diagnosis precede the implementation of control measures. A number of techniques have been used for diagnosis such as agar gel immunodiffusion, enzyme-linked immunosorbent assay (ELISA), molecular biological techniques such as polymerase chain reaction (PCR) and virus isolation in tissue culture. Many of these methods are both time consuming and require skilled personnel. The development of a rapid pen-side test for the detection of rinderpest virus (RPV) antigen in lachrymal fluid of cattle is described using the Clearview chromatographic strip test technology (Unipath, Bedford). Optimum conditions for binding monoclonal antibody to nitrocellulose and latex microspheres were determined and a prototype device was developed. The device detected viral antigen in lachrymal fluids from experimentally and naturally infected cattle and showed no cross-reactivity with other related viruses. A field trial was carried out at the Landhi Cattle Colony (LCC), Pakistan, to assess the performance of the rinderpest test under field conditions. Ninety-seven animals, some of which were showing various clinical signs, at LCC and neighbouring colonies were sampled and tested at the pen-side by Clearview and later by immunocapture ELISA (IC-ELISA) at IAH, Pirbright. Nineteen animals were positive by Clearview and/or IC-ELISA. Seventeen out of 19 rinderpest positive animals were positive by Clearview and 15 out of 19 were positive by IC-ELISA. Reverse transcription polymerase chain reaction (RT-PCR) confirmed the 19 animals to be rinderpest positive. This simple, rapid, specific test allows for the first time, accurate pen-side diagnosis of rinderpest.


Assuntos
Doenças dos Bovinos/diagnóstico , Doenças dos Bovinos/virologia , Kit de Reagentes para Diagnóstico/veterinária , Vírus da Peste Bovina/isolamento & purificação , Peste Bovina/diagnóstico , Peste Bovina/virologia , Animais , Anticorpos Monoclonais/metabolismo , Anticorpos Antivirais/metabolismo , Antígenos Virais/imunologia , Bovinos , Cromatografia/veterinária , Ensaio de Imunoadsorção Enzimática/veterinária , Paquistão , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Vírus da Peste Bovina/imunologia , Sensibilidade e Especificidade
9.
J Virol Methods ; 96(2): 189-202, 2001 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-11445149

RESUMO

Foot-and-mouth disease (FMD) is the most contagious animal virus disease of cloven-hoofed livestock and requires reliable and accurate diagnosis for the implementation of measures to control effectively its spread. Routine diagnosis of FMD is carried out at the OIE/FAO World Reference Laboratory for Foot-and-Mouth Disease (WRL for FMD), Pirbright by the combined use of ELISA and virus isolation in cell culture supplemented by reverse transcription polymerase chain reaction (RT-PCR) methods. These techniques require skilled personnel and dedicated laboratory facilities which are expensive. The development of a rapid and simple test for the detection of FMD virus antigen using Clearview chromatographic strip test technology for field application is described. This device detected FMD viral antigen in nasal swabs, epithelial suspensions and probangs from clinical samples submitted from the field, from animals infected experimentally and in supernatant fluids resulting from their passage in cell culture. The test system was more sensitive than ELISA for the diagnosis of all seven serotypes of FMD virus in the epithelial suspensions and nasal swabs and had equivalent sensitivity to the ELISA for the detection of contemporary virus strains in cell culture supernatant fluids. The study demonstrated the potential for this device to confirm a clinical diagnosis at the site of a suspected FMD outbreak, thereby offering the possibility of implementing control procedures more rapidly. Such pen-side diagnosis would have particular benefits in FMD emergencies, relevance to FMD control programmes which operate in endemic regions of the world such as South East Asia and for increasing disease awareness in other areas where efforts to control disease may be difficult. In each circumstance the availability of a pen-side device for diagnosis would reduce the necessity for sending routine diagnostic samples to an FMD laboratory and thereby reduce the delay in diagnosis, which can in some areas be considerable.


Assuntos
Antígenos Virais/análise , Aphthovirus/isolamento & purificação , Febre Aftosa/diagnóstico , Febre Aftosa/virologia , Kit de Reagentes para Diagnóstico/veterinária , Animais , Anticorpos Monoclonais/imunologia , Anticorpos Antivirais/imunologia , Aphthovirus/imunologia , Búfalos , Bovinos , Doenças dos Bovinos/diagnóstico , Doenças dos Bovinos/virologia , Células Cultivadas , Cromatografia/métodos , Cromatografia/veterinária , Ensaio de Imunoadsorção Enzimática , Sorotipagem , Suínos , Doenças dos Suínos/diagnóstico , Doenças dos Suínos/virologia , Fatores de Tempo
10.
Vet Microbiol ; 51(3-4): 207-16, 1996 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-8870184

RESUMO

The aetiological agent responsible for an epizootic of a rinderpest-like disease afflicting sheep and goats in three states of northern India was confirmed as peste des petits ruminants virus. To differentiate the virus from rinderpest a number of diagnostic tests were used, including immunocapture ELISA, specific oligonucleotide primers in a reverse transcriptase polymerase chain reaction, immunofluorescence with virus specific monoclonal antibodies and virus isolation. The virulence profile of one isolate in cattle sheep and goats was established. Infected animals developed specific antibody responses and excreted specific antigen in their lachrymal secretions.


Assuntos
Doenças das Cabras , Infecções por Morbillivirus/veterinária , Vírus da Peste dos Pequenos Ruminantes/isolamento & purificação , Animais , Anticorpos Monoclonais , Anticorpos Antivirais/biossíntese , Anticorpos Antivirais/sangue , Formação de Anticorpos , Bovinos , Doenças dos Bovinos , Primers do DNA , Ensaio de Imunoadsorção Enzimática/métodos , Imunofluorescência , Cabras , Índia , Dados de Sequência Molecular , Infecções por Morbillivirus/diagnóstico , Infecções por Morbillivirus/imunologia , Reação em Cadeia da Polimerase/métodos , Ovinos , Doenças dos Ovinos
11.
Vet Parasitol ; 68(1-2): 11-26, 1997 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-9066047

RESUMO

The production of monoclonal antibodies to the bloodstages of the haemoprotozoan parasites Babesia caballi and Babesia equi and the characterization of their corresponding antigens are described. Species specific and immunogenic proteins of both parasites were identified using SDS-PAGE, Western blotting and ELISA. These proteins were then electroeluted from SDS-PAGE gels and used to immunize BALB/c mice for hybridoma production. One monoclonal antibody (Mab), designated BC5.37.70.27 (BC5), recognized a 70 kDa protein of B. caballi as demonstrated by Western blotting under reducing conditions. Another Mab, BE1.24/2.95 (BEI), recognized a 34 kDa protein of B. equi. Both Mabs reacted specifically in indirect ELISA when isolated whole merozoites were used as antigen. Preliminary studies using the two Mabs in a competitive ELISA (cELISA) suggest that the cELISA for the detection of B. caballi infection is more sensitive than the commonly used complement fixation test but that refinement is necessary for the B. equi system.


Assuntos
Anticorpos Monoclonais , Babesia/isolamento & purificação , Babesiose/diagnóstico , Animais , Anticorpos Antiprotozoários , Especificidade de Anticorpos , Antígenos de Protozoários/análise , Babesia/imunologia , Babesiose/imunologia , Eletroforese em Gel de Poliacrilamida , Ensaio de Imunoadsorção Enzimática , Cavalos , Camundongos , Camundongos Endogâmicos BALB C/imunologia , Sensibilidade e Especificidade , Testes Sorológicos
12.
Curr Cancer Drug Targets ; 11(7): 799-809, 2011 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-21762082

RESUMO

The occurrence of chemoresistance is a serious problem in the treatment of cancer, urging the need for second and third-line treatment options that rely on different cell death pathways to overcome previously acquired resistance mechanisms. The inhibition of proteasomal activity by specific proteasome inhibitors or cross-reactivity of certain protease inhibitors with proteasomal enzymes recently became of interest because of the anti-tumoral properties of these agents. We tested the proteasome inhibitor bortezomib and the HIV protease inhibitor nelfinavir on human cervical cancer cells. Both drugs induced cell cycle arrest in cervical cancer cells, as reflected by marked changes in the expression of cell cycle-regulatory cyclins and ensuing mitochondrial-independent apoptosis. Upregulation of the molecular chaperone BiP and the cell stress marker ATF3 indicated induction of the unfolded protein response (UPR) as the main cause of apoptosis induced by these drugs in cervical cancer cells. Unlike in leukemia cells, bortezomib mainly inhibited the caspase-like activity of the proteasome in cervical cancer cells. Nelfinavir exhibited no effects on proteasomal activity in cervical cancer cells and leukemia cells. Although both bortezomib and nelfinavir acted on cisplatin-resistant cervical cancer cells (SiHa), neither of the drugs induced a sensitization to cisplatin treatment. Instead, both drugs could effectively be combined with each other, and enhanced the efficacy of an apoptosis-inducing TRAIL receptor antibody. These results suggest that both bortezomib and nelfinavir are effective agents against chemoresistant cervical cancer cells and might be of interest for clinical studies on cervical cancer patients with recurrent or metastatic cancer.


Assuntos
Apoptose/efeitos dos fármacos , Ácidos Borônicos/farmacologia , Caspases/metabolismo , Nelfinavir/farmacologia , Inibidores de Proteassoma , Pirazinas/farmacologia , Neoplasias do Colo do Útero/patologia , Antineoplásicos/farmacologia , Bortezomib , Ciclo Celular/efeitos dos fármacos , Sinergismo Farmacológico , Feminino , Inibidores da Protease de HIV/farmacologia , Humanos , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Receptores do Ligante Indutor de Apoptose Relacionado a TNF , Células Tumorais Cultivadas , Neoplasias do Colo do Útero/tratamento farmacológico , Neoplasias do Colo do Útero/metabolismo
13.
Br Vet J ; 152(2): 139-51, 1996 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-8680838

RESUMO

Two haemoprotozoan parasites, Babesia caballi and Babesia equi, can cause equine piroplasmosis. Due to the presence of potential tick vectors in areas so far unaffected by equine babesias, import and export regulations often require the serum testing of animals for evidence of infection. Although the complement fixation test (CFT) has been recommended for detecting the presence of antibodies to Babesia spp., it has been demonstrated to have several disadvantages, including false-positive results and low sensitivity for detecting latent infections. An enzyme-linked immunosorbent assay (ELISA) may be an alternative for increased and sensitive detection of acute and latent babesial infections, but its development to date has been hindered by a limited antigen supply and poor specificity. In vitro cultivation of both parasite species and the identification of parasite proteins for diagnostic use has facilitated the development of a highly sensitive and specific ELISA. For the direct detection of the parasites, DNA probes are now available. Several drugs are available for the treatment of equine piroplasmosis. For instance, diminazene diaceturate is effective in the chemosterilization of B. caballi and in the elimination of clinical signs in B. equi infections. Antitheilericidal drugs such as buparvaquone have been demonstrated to be effective in combatting disease due to B. equi and may--in combination with imidocarb--also eliminate the parasite. The control of equine piroplasmosis must include effective tick control, seromonitoring of animals and the application of chemotherapy.


Assuntos
Babesiose/diagnóstico , Doenças dos Cavalos/diagnóstico , Animais , Babesiose/parasitologia , Babesiose/terapia , Doenças dos Cavalos/parasitologia , Doenças dos Cavalos/terapia , Cavalos
14.
Gene Ther ; 10(3): 198-205, 2003 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-12571626

RESUMO

The coxsackie adenovirus receptor (CAR) has become of interest for gene therapy due to its crucial function in adenoviral cell entry. In clinical trials with adenoviral vectors, dexamethasone is applied to reduce side effects such as inflammatory reactions or emesis. By using a beta-galactosidase-expressing adenovirus (AdGal), we observed that dexamethasone treatment resulted in decreased adenoviral gene transfer into human cancer cells. Expression of CAR and integrin alpha5beta1 was transcriptionally downregulated by dexamethasone as shown for HeLa cervical cancer cells and U87MG glioblastoma cells. TNFalpha increased CAR expression in HeLa and ovarian cancer cells but decreased CAR expression in U87MG cells. In all tested cancer cell lines, TNFalpha induced a significant increase in the expression of adenovirus-binding integrins alpha5beta1, alphavbeta3 and alphavbeta5. Pretreatment with TNFalpha increased AdGal gene transfer into cancer cells and enhanced the cytotoxic effect of a p53-expressing adenovirus. In contrast, TGFbeta reduced CAR expression level and adenoviral gene transfer into OV-UL-2 ovarian cancer cells. Confocal immunofluorescence analysis revealed localization of CAR at cell-cell adhesions in several human cancer cell lines and disruption of cell-cell contacts increased adenoviral gene transfer into human cancer cells. In clinical cancer gene therapy, efficiency of adenoviral gene delivery could be altered by cell adhesion, TNFalpha, TGFbeta, and dexamethasone.


Assuntos
Anti-Inflamatórios/efeitos adversos , Proteínas de Ligação ao Cálcio/genética , Citocinas/farmacologia , Dexametasona/efeitos adversos , Proteínas do Olho , Regulação da Expressão Gênica/efeitos dos fármacos , Lipoproteínas , Neoplasias/terapia , Proteínas do Tecido Nervoso , Adenoviridae/genética , Anti-Inflamatórios/farmacologia , Proteínas de Ligação ao Cálcio/análise , Adesão Celular/efeitos dos fármacos , Dexametasona/farmacologia , Feminino , Citometria de Fluxo , Imunofluorescência , Expressão Gênica , Terapia Genética/métodos , Vetores Genéticos/administração & dosagem , Células HeLa , Hipocalcina , Humanos , Integrina alfa5beta1/genética , Integrina alfaVbeta3/genética , Integrinas/genética , Neoplasias/metabolismo , Receptores de Vitronectina/genética , Recoverina , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transdução Genética/métodos , Fator de Crescimento Transformador beta/farmacologia , Transgenes , Células Tumorais Cultivadas , Fator de Necrose Tumoral alfa/farmacologia , beta-Galactosidase/genética
15.
J Biol Chem ; 267(8): 5052-5, 1992 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-1544889

RESUMO

Brefeldin A leads to an increase of sphingomyelin in Chinese hamster ovary cells. The antibiotic is known to cause a dramatic morphological change of the endomembrane system in various mammalian cells resulting in a redistribution of Golgi resident proteins to the endoplasmic reticulum (Lippincott-Schwartz, J., Donaldson, J. G., Schweizer, A., Berger, E. G., Hauri, H. P., Yuan, L. C., and Klausner, R. D. (1990) Cell 60, 821-836). A strict correlation was found between the brefeldin A-induced increase of sphingomyelin and the biochemical criteria that apply for this morphological change. From our data we conclude that the increase in sphingomyelin caused by brefeldin A reflects translocation of the enzyme sphingomyelin synthase from the Golgi apparatus to the endoplasmic reticulum. Using a radioactively labeled truncated ceramide this increase in sphingomyelin synthesis is easily detectable, and thus this method can serve as a convenient biochemical assay for the action of brefeldin A in mammalian cells.


Assuntos
Antibacterianos/farmacologia , Ciclopentanos/farmacologia , Esfingomielinas/biossíntese , Animais , Brefeldina A , Células CHO , Linhagem Celular , Colina/metabolismo , Colforsina/farmacologia , Cricetinae , Complexo de Golgi/efeitos dos fármacos , Complexo de Golgi/metabolismo , Cinética , Técnica de Diluição de Radioisótopos , Trítio
16.
Eur J Clin Invest ; 34(4): 268-74, 2004 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-15086358

RESUMO

BACKGROUND: The synthetic beta(2)-adrenergic and dopaminergic agonist dopexamine is supposed to prevent splanchnic hypoperfusion in critically ill patients, thus potentially interacting with haemodynamic effects of early enteral nutrition. However, precise mechanism of action and interaction with postprandial splanchnic hyperaemia of the drug are largely unknown, even in healthy subjects. MATERIALS AND METHODS: Twelve healthy volunteers received dopexamine 1 microg x kg(-1) min(-1) and dopexamine and placebo (NaCl 0.9%) 3 microg x kg(-1) min(-1) in a randomized, double-blinded order (crossover-design). Splanchnic (Doppler ultrasound) and systemic (noninvasive cardiac monitoring) haemodynamic parameters were assessed at baseline and during infusion (fasted as well as 15, 30, 45 and 60 min after a standard liquid meal). RESULTS: In fasted humans, dopexamine enhanced time-averaged maximum velocity (TAMX) in the superior mesenteric artery (1 microg + 40%; 3 microg + 82%, P < 0.05), portal vein (+ 63%; + 121%, P < 0.05) and femoral artery (+ 66%; + 87%, P < 0.05), in proportion to the increase of cardiac index (+ 33%; + 77%, both P < 0.05). In the postprandial state, TAMX rose significantly in the superior mesenteric artery (+ 139%) and portal vein (+ 68%) in the placebo group, showing the same absolute extent as dopexamine. The physiological postprandial buffer response of hepatic artery was conserved under all conditions. CONCLUSIONS: Continuous infusion of dopexamine enhances mesenterial and portal perfusion in a dose-dependent manner without affecting the extent of physiological postprandial hyperaemia. Thus, dopexamine and enteral nutrition may interact with splanchnic haemodynamics by different pathways.


Assuntos
Agonistas Adrenérgicos beta/uso terapêutico , Agonistas de Dopamina/uso terapêutico , Dopamina/análogos & derivados , Dopamina/uso terapêutico , Hemodinâmica/efeitos dos fármacos , Hiperemia/prevenção & controle , Abdome/diagnóstico por imagem , Adulto , Velocidade do Fluxo Sanguíneo/efeitos dos fármacos , Pressão Sanguínea/efeitos dos fármacos , Método Duplo-Cego , Feminino , Artéria Femoral/fisiopatologia , Artéria Hepática/fisiopatologia , Humanos , Hiperemia/diagnóstico por imagem , Masculino , Artérias Mesentéricas/fisiopatologia , Pessoa de Meia-Idade , Veia Porta/fisiopatologia , Período Pós-Prandial , Ultrassonografia , Resistência Vascular/efeitos dos fármacos
17.
J Biol Chem ; 267(11): 7726-32, 1992 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-1560007

RESUMO

Radioactively labeled brefeldin A was used to probe for proteins that interact with this metabolite. The most prominent protein labeled after in vivo incubation of Chinese hamster ovary cells with [3H]brefeldin A turned out to have an apparent molecular mass of 26 kDa. Radioactive peptides derived from the [3H]brefeldin A-labeled protein showed sequence identity with glutathione S-transferases, and immunoblotting after two-dimensional gel electrophoresis confirmed this result. In addition, Chinese hamster ovary cells convert the antibiotic to its glutathionyl and cysteinyl derivatives and secrete them rapidly into the medium. From these findings we conclude that detoxification of the antibiotic in mammalian cells occurs via the glutathion S-transferase system. This may explain the often observed reversibility of brefeldin A's action on the steady state of organelles in mammalian cells.


Assuntos
Antibacterianos/metabolismo , Ciclopentanos/metabolismo , Cisteína/metabolismo , Glutationa Transferase/metabolismo , Glutationa/metabolismo , Sequência de Aminoácidos , Animais , Western Blotting , Encéfalo/metabolismo , Brefeldina A , Células CHO , Bovinos , Cromatografia Líquida de Alta Pressão , Cricetinae , Eletroforese em Gel Bidimensional , Eletroforese em Gel de Poliacrilamida , Dados de Sequência Molecular
18.
Arch Microbiol ; 170(2): 99-105, 1998 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-9683646

RESUMO

The screening of 20,000 Saccharomyces cerevisiae random mutants to identify genes involved in the osmotic stress response yielded 14 mutants whose growth was poor in the presence of elevated concentrations of NaCl and glucose. Most of the mutant strains were more sensitive to NaCl than to glucose at the equivalent water activity (aw) and were classified as salt-sensitive rather than osmosensitive. These mutants fell into 11 genetic complementation groups and were designated osr1-osr11 (osmotic stress response). All mutations were recessive and showed a clear 2(+) : 2(-) segregation of the salt-stress phenotype upon tetrad analysis when crossed to a wild-type strain. The complementation groups osr1, osr5 and osr11 were allelic to the genes PBS2, GPD1 and KAR3, respectively. Whereas intracellular and extracellular levels of glycerol increased in the wild-type strains when exposed to NaCl, all mutants demonstrated some increase in extracellular glycerol production upon salt stress, but a number of the mutants showed little or no increase in intracellular glycerol concentrations. The mutants had levels of glycerol-3-phosphate dehydrogenase, an enzyme induced by osmotic stress, either lower than or similar to those of the parent wild-type strain in the absence of osmotic stress. In the presence of NaCl, the increase in glycerol-3-phosphate dehydrogenase activity in the mutants did not match that of the parent wild-type strain. None of the mutants had defective ATPases or were sensitive to heat stress. It is evident from this study and from others that a wide spectrum of genes is involved in the osmotic stress response in S. cerevisiae.


Assuntos
Pressão Osmótica , Saccharomyces cerevisiae/genética , Divisão Celular/efeitos dos fármacos , Metanossulfonato de Etila/farmacologia , Genes Recessivos/genética , Teste de Complementação Genética , Glicerol/metabolismo , Glicerolfosfato Desidrogenase/metabolismo , Soluções Hipertônicas/farmacologia , Mutagênese/genética , Cloreto de Sódio/farmacologia
19.
J Hepatol ; 28(4): 631-8, 1998 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-9566832

RESUMO

BACKGROUND/AIMS: Diminished postprandial portal hyperemia has been demonstrated by echo-Doppler flowmetry in patients with liver cirrhosis, but its diagnostic role is unclear. This prospective study was therefore undertaken in patients with varying severity of portal hypertension and degree of liver cirrhosis. METHODS: Portal flowmetry was performed in 66 patients with cirrhosis and 20 healthy volunteers during fasting and 30 min after ingestion of a standardized meal. Hemodynamic parameters were related to the degree of esophageal varices, variceal bleeding, portal hypertensive gastropathy and Child-Pugh score. RESULTS: The postprandial portal blood velocity increment was low in patients with esophageal varices of any degree (22-24%), compared to patients without varices (49%, p<0.01) and healthy controls (65%, p<0.001), but was not different in patients with or without variceal bleeding (22% vs. 20%). In contrast, the congestion index (CI; ratio of portal vein cross-sectional area and portal blood velocity) pre-/postprandial decreased in the bleeding group only (CI pre/ CI post 1.30+/-0.23 (no bleeding) vs. 0.86+/-0.29 (bleeding); p<0.01). Portal hypertensive gastropathy was not related to any of the portal flow parameters. The portal blood velocity increment was comparable in controls (65%) and patients with Child-Pugh class A cirrhosis (56%), but lower in patients with class B (32%) and class C cirrhosis (15%, p<0.05 vs. class A). Also, there was no postprandial decrease in congestion index in patients with the most severe cirrhosis (p<0.01 class C vs. class A and B). CONCLUSIONS: The postprandial rise in portal flow is inversely related to the severity of portal hypertension and liver cirrhosis, and may be a valuable parameter with respect to the risk of variceal bleeding.


Assuntos
Hipertensão Portal/fisiopatologia , Cirrose Hepática/fisiopatologia , Sistema Porta/fisiologia , Período Pós-Prandial , Adulto , Idoso , Idoso de 80 Anos ou mais , Velocidade do Fluxo Sanguíneo , Estudos de Casos e Controles , Varizes Esofágicas e Gástricas/fisiopatologia , Feminino , Hemodinâmica/fisiologia , Humanos , Hipertensão Portal/diagnóstico por imagem , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Valores de Referência , Ultrassonografia Doppler Dupla
20.
Z Gerontol Geriatr ; 30(3): 208-19, 1997.
Artigo em Alemão | MEDLINE | ID: mdl-9333452

RESUMO

The following article contains a short review on gastrointestinal problems of the elderly. The diseases of the esophagus occurring in the elderly are not much different from those in younger patients. Clinically relevant in the stomach are above all bleeding ulcerations and the gastric carcinoma occurring more frequently in advanced age. The pyogenic liver abscess is diagnosed primarily in the elderly and is at a rule the consequence of an infection of the gall bladder and other abdominal sites. The hepatocellular carcinoma does not grow rapidly in the elderly, but its accompanying unfavourable survival rate at five years is also approximately 5 per cent. In the case of symptomatic cholelithiasis, older high risk patients do especially profit from minimally invasive laparoscopic surgical procedures. Today, bile duct calculi are preferably treated by endoscopic papillotomy and following extraction of the calculi. The pancreas is subjected to atrophy, lipomatosis and fibrosis at the advanced age. However, these changes are rarely of clinical relevance. A frequent problem in clinical practice is that of constipation, from which 35% of patients suffer above the age of 65 years. Another typical symptom of the elderly is the incontinence, the different causes are being discussed. In advanced age, gastrointestinal hemorrhages are mostly occurring above the Treitz's ligament. Hemorrhages of the lower gastrointestinal tract occur mostly in the form of diverticle bleedings and those of angiodysplasias in the elderly. The diverticulosis is also a disease observed in over 50 per cent of patients above 70 years, but it is symptomatic in only part of the patients. When suspecting an inflammatory bowel disease in the elderly, the possibility of a mesenterial ischemia must always be considered as differential diagnosis. The classical chronic inflammatory bowel diseases can, however, also occur at advanced age. The colon carcinoma is one of the most frequent lethal causes in the Western countries 90 per cent of the cases of colon carcinoma are found in patients older than 50 years of age. Intensive attention is therefore required in this age group.


Assuntos
Gastroenteropatias/etiologia , Neoplasias Gastrointestinais/etiologia , Idoso , Diagnóstico Diferencial , Gastroenteropatias/diagnóstico , Gastroenteropatias/terapia , Neoplasias Gastrointestinais/diagnóstico , Neoplasias Gastrointestinais/terapia , Humanos , Prognóstico
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