Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 13 de 13
Filtrar
1.
Epidemiol Infect ; 147: e11, 2018 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-30236166

RESUMO

Typhoid fever is an illness caused by Salmonella enterica serotype Typhi. In developing regions, it affects an estimated 20 million people annually, causing 200 000 deaths. Although uncommon, cases occur in the USA each year, predominantly due to international travel. During February 2015, the Oklahoma State Department of Health (OSDH) detected an outbreak of typhoid fever among residents of northwestern Oklahoma. OSDH conducted case-patient interviews to identify the source and symptomatic contacts. Whole genome sequencing (WGS) was performed to characterise the genetic relatedness of isolates among the four outbreak-associated pulsed-field gel electrophoresis (PFGE) patterns. We identified 38 cases, 25 confirmed and 13 probable, in two states. WGS revealed a 0-10 single-nucleotide polymorphism variation between isolates. Although we were unable to determine the source, almost all case-patients were members of the Marshallese community that attended a common event in Oklahoma, or were contacts to a confirmed case. This is the largest outbreak of typhoid fever in the USA since 1989, and first to apply WGS to complement interpretation of PFGE results during a typhoid fever outbreak investigation. This investigation illustrates the potential risk of outbreaks among communities comprised of international populations from regions where typhoid fever remains endemic.

2.
Curr Med Chem ; 20(38): 4815-26, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24083609

RESUMO

Treatment of murine EL4 T cell lymphoma with N-(2-hydroxypropyl)methacrylamide (HPMA) copolymer conjugates of doxorubicin (Dox) leads to complete tumor regression and to the development of therapy-dependent longlasting cancer resistance. This phenomenon occurs with two types of Dox conjugates tested, despite differences in the covalent linkage of Dox to the polymer carrier. Such a cancer resistance cannot fully express in conventional treatment with free Dox, due to substantial immunotoxicity of the treatment, which was not observed in the polymer conjugates. In this study, calreticulin (CRT) translocation and high mobility group box-1 protein (HMGB1) release was observed in EL4 cells treated with a conjugate releasing Dox by a pH-dependent manner. As a result, the treated tumor cells were engulfed by dendritic cells (DC) in vitro, and induced their expression of CD80, CD86, and MHC II maturation markers. Conjugates with Dox bound via an amide bond only increased translocation of HSPs to the membrane, which led to an elevated phagocytosis but was not sufficient to induce increase of the maturation markers on DCs in vitro. Both types of conjugates induced engulfment of the target tumor cells in vivo, that was more intense than that seen with free Dox. It means that the induction of anti-tumor immunity documented upon treatment of EL4 lymphoma with HPMA-bound Dox conjugates does not rely solely on CRT-mediated cell death, but involves multiple mechanisms.


Assuntos
Antineoplásicos/toxicidade , Apoptose/efeitos dos fármacos , Doxorrubicina/análogos & derivados , Ácidos Polimetacrílicos/toxicidade , Animais , Antineoplásicos/administração & dosagem , Antineoplásicos/química , Antígeno B7-1/metabolismo , Antígeno B7-2/metabolismo , Calreticulina/metabolismo , Linhagem Celular Tumoral , Células Dendríticas/citologia , Células Dendríticas/imunologia , Doxorrubicina/administração & dosagem , Doxorrubicina/química , Doxorrubicina/toxicidade , Portadores de Fármacos/química , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Proteína HMGB1/metabolismo , Proteínas de Choque Térmico/metabolismo , Concentração de Íons de Hidrogênio , Linfoma de Células T/tratamento farmacológico , Linfoma de Células T/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Fagocitose , Ácidos Polimetacrílicos/administração & dosagem , Ácidos Polimetacrílicos/química
3.
Mol Pharm ; 7(4): 1027-40, 2010 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-20524698

RESUMO

The cytostatic effects of polymeric conjugates based on N-(2-hydroxypropyl)methacrylamide copolymers (PHPMA) and containing doxorubicin bound through amide and hydrazone bonds (mixed conjugates) were compared with the cytostatic effects of monoconjugates containing drug bound through an amide or hydrazone bond. One group of mixed conjugates was formed from two comonomers containing doxorubicin bound to the methacryloyl group through a spacer and an amide (DOX(AM)) or hydrazone (DOX(HYD)) bond via copolymerization with HPMA. A second group of mixed conjugates was formed from two different interconnected HPMA copolymers, one containing DOX(AM) and the other DOX(HYD), forming a high-molecular-weight branched structure. The third mixed polymeric system was a simple mixture of monoconjugates DOX(AM)-PHPMA and DOX(HYD)-PHPMA. Simultaneous treatment with all mixed forms of the polymeric derivatives of doxorubicin significantly increased antitumor efficacy after application of monoconjugates, suggesting a synergizing effect that could be used in designing new doxorubicin-containing therapeutic systems.


Assuntos
Acrilamidas/química , Amidas/química , Doxorrubicina/química , Doxorrubicina/farmacologia , Hidrazonas/química , Polímeros/química , Animais , Antibióticos Antineoplásicos/química , Antibióticos Antineoplásicos/farmacologia , Linhagem Celular , Linhagem Celular Tumoral , Humanos , Linfoma de Células T/tratamento farmacológico , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Nus , Microscopia de Fluorescência , Estrutura Molecular , Polímeros/síntese química
4.
J Control Release ; 99(2): 301-14, 2004 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-15380639

RESUMO

N-(2-Hydroxypropyl)methacrylamide (HPMA) copolymer carrier containing the anticancer drug doxorubicin bound either by a proteolytically degradable bond (non-targeted PK1 or targeted with alpha-CD71 mAb) or by a hydrolytically degradable bond were synthesised and tested in vivo for various biological properties. Mouse 38C13 B-cell lympoma was used as a well established and defined cell line for this study. 38C13 cells are sensitive to free doxorubicin and IC50 was very low, about 0.014 microM. PK1 showed a strongly decreased cytostatic effect, IC50 being 12.6 microM. alpha-CD71 targeted conjugate, which can be considered as an antibody-targeted form of PK1, had IC50 0.358 microM. HPMA copolymer with doxorubicin bound via a hydrolytically sensitive bond (HYD conjugate) showed a high cytostatic effect with IC50 about 0.052 microM. We demonstrated that HYD conjugate inhibited DNA synthesis and induced p21(Waf1/Cip1) protein expression (p21(Waf1/Cip1) is cyclin-dependent kinase inhibitor which blocks cell cycle progression) as quickly as free doxorubicin, whereas PK1 acted much more slowly. Similarly, apoptosis induction measured by Annexin V binding and Caspase 3 activity was detected later after incubation of cells with PK1 or alpha-CD71 targeted conjugate. Apoptosis was manifested by elevation of bax and bad mRNA levels, which was much more rapid and intense in the case of free doxorubicin and HYD conjugate. Expression of antiapoptotic genes as well as cyclin-dependent kinases was surprisingly not affected.


Assuntos
Acrilamidas/síntese química , Acrilamidas/farmacologia , Doxorrubicina/síntese química , Doxorrubicina/farmacologia , Ligantes , Acrilamidas/metabolismo , Animais , Apoptose/efeitos dos fármacos , Proteínas de Transporte/genética , Proteínas de Transporte/metabolismo , Caspase 3 , Caspases/efeitos adversos , Caspases/efeitos dos fármacos , Caspases/metabolismo , Ciclo Celular/genética , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Linhagem Celular Tumoral , Membrana Celular/efeitos dos fármacos , Membrana Celular/patologia , Proliferação de Células/efeitos dos fármacos , Inibidor de Quinase Dependente de Ciclina p21 , DNA/antagonistas & inibidores , DNA/genética , DNA/metabolismo , Doxorrubicina/metabolismo , Avaliação Pré-Clínica de Medicamentos/métodos , Expressão Gênica/efeitos dos fármacos , Expressão Gênica/genética , Genes myc/efeitos dos fármacos , Genes myc/genética , Hidrazonas/síntese química , Hidrazonas/metabolismo , Hidrazonas/farmacologia , Hidrólise , Concentração Inibidora 50 , Camundongos , Proteínas Proto-Oncogênicas c-bcl-2/genética , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , RNA Mensageiro/genética , Receptores da Transferrina/efeitos dos fármacos , Receptores da Transferrina/genética , Timidina/metabolismo , Trítio , Proteína X Associada a bcl-2 , Proteína de Morte Celular Associada a bcl
5.
Folia Microbiol (Praha) ; 49(3): 327-36, 2004.
Artigo em Inglês | MEDLINE | ID: mdl-15259776

RESUMO

When feeding on vertebrate host ticks (ectoparasitic arthropods and potential vectors of bacterial, rickettsial, protozoal, and viral diseases) induce both innate and specific acquired host-immune reactions as part of anti-tick defenses. In a resistant host immune defense can lead to reduced tick viability, sometimes resulting in tick death. Tick responds to the host immune attack by secreting saliva containing pharmacologically active molecules and modulating host immune response. Tick saliva-effected immunomodulation at the attachment site facilitates both tick feeding and enhances the success of transmission of pathogens from tick into the host. On the other hand, host immunization with antigens from tick saliva can induce anti-tick resistance and is seen to be able to induce immunity against pathogens transmitted by ticks. Many pharmacological properties of saliva described in ticks are shared widely among other blood-feeding arthropods.


Assuntos
Interações Hospedeiro-Parasita/efeitos dos fármacos , Imunidade/efeitos dos fármacos , Proteínas e Peptídeos Salivares/farmacologia , Doenças Transmitidas por Carrapatos/transmissão , Carrapatos/imunologia , Animais , Vetores Aracnídeos , Interações Hospedeiro-Parasita/imunologia , Glândulas Salivares/fisiologia , Infestações por Carrapato/imunologia , Doenças Transmitidas por Carrapatos/imunologia , Carrapatos/química , Carrapatos/microbiologia
6.
Am Heart J ; 142(5): E9, 2001 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11685184

RESUMO

BACKGROUND: Stent placement has historically been preceded by predilation of the target lesion with percutaneous transluminal coronary angioplasty. Direct stent implantation, without predilation, has the potential to have a favorable impact on procedure cost by reducing the number of devices used, contrast administered, and procedure time. METHODS AND RESULTS: We conducted a prospective randomized trial to compare the economic outcome of stenting with or without predilation. Inclusion criteria included intention to treat a single lesion with a coronary stent in a vessel with a reference diameter >2.4 mm. Exclusion criteria included total occlusions, culprit lesion within a saphenous vein graft, lesion length >25 mm, patients within 48 hours of an acute myocardial infarction, and patients unable to be treated with aspirin and clopidogrel. From September 1999 to March 2000, 77 patients were randomized to direct stent implantation (n = 37) or balloon-facilitated stenting (n = 40). Stent placement was successful in all patients. Crossover to predilation was required in 2 patients in the direct stent group because of inability to deliver the stent. Compared with balloon-facilitated stenting, direct stenting used fewer catheter devices (1.4 +/- 0.7 vs 2.5 +/- 0.8, P <.001), less contrast (92.7 +/- 43.1 mL vs 117.4 +/- 61.0 mL, P =.04), and less fluoroscopy time (7.5 +/- 3.9 minutes vs 11.6 +/- 8.3 minutes, P =.006). No difference in procedural complications or predischarge outcome was found. No difference in major adverse cardiovascular events was found at 6-month follow-up. CONCLUSION: Direct stenting is a safe and successful procedure that reduces the number of devices used, fluoroscopy time, and contrast administration.


Assuntos
Angioplastia Coronária com Balão/métodos , Doença das Coronárias/terapia , Stents , Procedimentos Cirúrgicos Vasculares/métodos , Angioplastia Coronária com Balão/economia , Cateterismo Cardíaco/economia , Cateterismo Cardíaco/métodos , Cateterismo Cardíaco/estatística & dados numéricos , Terapia Combinada/economia , Terapia Combinada/métodos , Meios de Contraste/administração & dosagem , Angiografia Coronária , Doença das Coronárias/economia , Doença das Coronárias/cirurgia , Vasos Coronários/cirurgia , Feminino , Fluoroscopia/economia , Fluoroscopia/estatística & dados numéricos , Custos de Cuidados de Saúde , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Stents/economia , Resultado do Tratamento , Procedimentos Cirúrgicos Vasculares/economia
7.
J Parasitol ; 87(6): 1342-8, 2001 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11780819

RESUMO

Tick salivary gland extract (SGE) was previously shown to inhibit murine T cell proliferation. In mice, SGE has an inhibitory effect on Th1 and a stimulatory effect on Th2 cytokine elaboration. In the present study, tick-mediated immunomodulation of human T cell proliferation and cytokine elaboration was analyzed using human peripheral blood mononuclear cells (PBMCs) stimulated with concanavalin A (Con A) or lipopolysaccharide (LPS). Using flow cytometry, tick saliva-induced changes were investigated in human mononuclear cell subpopulations. SGE from Ixodes ricinus dose-dependently inhibited human T cell proliferation. This finding supports the flow cytometry data, showing that the percentage of Con A-activated HLA-DR-CD3+ T lymphocytes and CD4+ CD8+ double-positive T cells decreased after SGE treatment. SGE significantly inhibited the in vitro production of interleukin-2 (IL-2) and interferon-gamma (IFN-gamma) secreted by Th1 lymphocytes. In contrast, the elaboration of IL-4, IL-6, and IL-10 secreted by Th2 lymphocytes was significantly stimulated by I. ricinus SGE. Similarly, the production of both IL-1alpha and IL-1beta was significantly stimulated after SGE treatment. These data indicate that the tick-induced immunomodulatory events in humans are similar to those previously described in a murine model.


Assuntos
Citocinas/biossíntese , Ixodes/imunologia , Glândulas Salivares/imunologia , Linfócitos T/imunologia , Células Th2/imunologia , Adjuvantes Imunológicos , Animais , Células Cultivadas , Humanos , Ativação Linfocitária , Linfócitos T/citologia , Células Th2/citologia
8.
Parasitology ; 116 ( Pt 2): 139-47, 1998 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-9509023

RESUMO

Schistosome cercariae of the genus Trichobilharzia are the causative agent of swimmers' itch. In order to characterize the changes in parasites during and after the penetration of the host skin, in vitro and in vivo (in ducks and mice) transformations of T. szidati cercariae to schistosomula were performed. Ultrastructural observation revealed that cercariae possess a simple outer tegumental membrane with a thick glycocalyx. As with human schistosomes, the latter structure disappears during transformation and a new double membrane with putative protective function is formed. Our biochemical and immunological observations showed that the carbohydrate-rich glycocalyx of cercariae is readily bound by lectins and antibodies. The in vitro transformation to schistosomula can be detected by enhanced reactivity of 2 lectin probes (PNA and ConA) with the surface. The in vivo-transformed (skin and lung) schistosomula appear to have few surface ligands for the 12 lectin probes being tested. Similarly, the cercarial surface and its remnants on the in vitro-produced schistosomula is recognized by sera from immunized mice and humans with cercarial dermatitis; the tissue schistosomula fail to react with these antibodies. The loss of surface targets as a part of parasite immune evasion within the host is discussed.


Assuntos
Schistosoma/imunologia , Schistosoma/ultraestrutura , Animais , Anticorpos Anti-Helmínticos/análise , Carboidratos/análise , Patos , Epitopos/análise , Técnica Direta de Fluorescência para Anticorpo , Técnica Indireta de Fluorescência para Anticorpo , Interações Hospedeiro-Parasita , Humanos , Camundongos , Camundongos Endogâmicos BALB C/parasitologia , Microscopia Eletrônica , Schistosoma/química , Schistosoma/crescimento & desenvolvimento , Schistosoma/fisiologia
9.
J Am Coll Cardiol ; 30(5): 1284-7, 1997 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-9350928

RESUMO

OBJECTIVES: The objectives of this study were to define the hemostatic profiles of patients with unstable angina compared with patients with stable angina and to investigate the effect of percutaneous interventions on the follow-up hemostatic profiles of these patients. BACKGROUND: Disturbances in hemostatic factors have been shown to be present in various clinical syndromes involving coronary artery disease. However, their role in stable angina versus unstable angina is less well defined. METHODS: We studied 61 patients with either stable or unstable angina undergoing percutaneous coronary interventions. Blood samples were drawn immediately before the intervention and at 1-month follow-up. Plasma levels of tissue-type plasminogen activator (t-PA), plasminogen activator inhibitor-1 (PAI-1) and von Willebrand factor (vWF) were measured by enzyme-linked immunosorbent assays. RESULTS: Patients with unstable angina had significantly higher t-PA levels (mean [+/-SE] 23.7 +/- 3.4 vs. 14.3 +/- 1.4 ng/ml, respectively, p = 0.02) and vWF antigen concentrations (2,231 +/- 157 vs. 1,792 +/- 108 mU/ml, respectively, p = 0.03) than patients with stable angina. No statistically significant differences were observed in the PAI-1 levels between the two groups (27.9 +/- 5.5 vs. 21.4 +/- 2.5 ng/ml, respectively, p = 0.25). At 1-month follow-up, there were no longer any significant differences in the t-PA or vWF levels between the two groups (15.7 +/- 1.2 vs. 13.6 +/- 0.6 ng/ml, p = 0.13; 1,962 +/- 170 vs. 1,809 +/- 88 mU/ml, p = 0.39, respectively). There were no significant differences between the hemostatic profiles of patients undergoing percutaneous transluminal coronary angioplasty or coronary stenting initially and at 1-month follow-up. CONCLUSIONS: These data suggest that elevated plasma levels of t-PA and vWF may correlate with instability of atheromatous plaques, and that their decrease after coronary interventions may reflect plaque reendothelialization and stabilization.


Assuntos
Angina Pectoris/sangue , Angina Instável/sangue , Angioplastia Coronária com Balão , Hemostasia , Stents , Ativador de Plasminogênio Tecidual/sangue , Fator de von Willebrand/análise , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
10.
Ukr Biokhim Zh (1978) ; 68(5): 85-9, 1996.
Artigo em Inglês | MEDLINE | ID: mdl-9229858

RESUMO

Glucose and xylose are the principal monomeric units of plant carbohydrates. Butyrivibrio fibrisolvens, an important rumen bacterium, converted both sugars to formate, acetate, butyrate and lactate. More metabolites and less cell biomass was formed from xylose than from glucose. In cultures with both substrates, glucose was utilized preferentially. Growth on glucose was more rapid than on xylose. No phosphoketolase activity (EC 4.1.2.9) was detected in this strain. More carbohydrate and less protein was found in glucose-grown cells than in cells grown on xylose. Growth yields of protein were higher on xylose, in spite of the fact, that yields of cellular dry matter were higher on glucose.


Assuntos
Fermentação/fisiologia , Glucose/metabolismo , Bactérias Anaeróbias Gram-Negativas/metabolismo , Xilose/metabolismo , Aldeído Liases/metabolismo , Proteínas de Bactérias/metabolismo , Divisão Celular/fisiologia , Bactérias Anaeróbias Gram-Negativas/crescimento & desenvolvimento , L-Lactato Desidrogenase/metabolismo , Lactobacillus/metabolismo
11.
J Trauma ; 35(4): 643-6, 1993 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-8411291

RESUMO

Routine morning chest x-ray films (CXRs) are widely obtained in surgical intensive care unit (SICU) patients. During a 1-month time period we prospectively evaluated 525 routine morning CXRs in patients admitted to the SICU of a university trauma center (n = 256) or a suburban affiliate hospital (n = 269) to assess the impact of these CXRs on patient care. All CXRs were read by radiologists. Data on position of medical devices (CVP lines, endotracheal tubes, etc.) and cardiopulmonary (CP) findings were collected. A total of 1028 medical devices were evaluated. Fifty-five (5.4%) were considered to be in a minor incorrect position that did not adversely affect patient care and only 13 (1.3%) devices required repositioning for patient care or safety. Seventy-eight CXRs were read as normal. There were 775 CP findings on the remaining 477 CXRs. When compared with previous CXRs, only 12% (89 of 775) of the findings were considered new, 65% were unchanged, 14% were improved, and 15% demonstrated worsening of a known finding. Of the 89 new CP findings, only three had any potential clinical impact (pneumothorax in two, effusion in one). These data demonstrate an extremely low yield of clinically significant and unsuspected new CP findings or device malposition on the routine morning CXR. We conclude that routine daily chest radiography should be abandoned and that the need for a morning CXR should be based on clinical necessity.


Assuntos
Unidades de Terapia Intensiva , Radiografia Torácica/estatística & dados numéricos , Revisão da Utilização de Recursos de Saúde , Adulto , Idoso , Idoso de 80 Anos ou mais , Humanos , Pessoa de Meia-Idade , New Jersey , Complicações Pós-Operatórias/diagnóstico por imagem , Estudos Prospectivos , Avaliação da Tecnologia Biomédica
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...