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1.
Artigo em Inglês | MEDLINE | ID: mdl-29851173

RESUMO

OBJECTIVES: Apathy, a lack of motivation, is frequently seen in older individuals, with and without depression, with substantial impact on quality of life. This prospective cohort study of patients with severe late-life depression treated with electroconvulsive therapy (ECT) aims to study the course of apathy and the predictive value of vascular burden and in particular white matter hyperintensities on apathy course. METHODS: Information on apathy (defined by a score of >13 on the Apathy Scale), depression severity, vascular burden, and other putative confounders was collected in at 2 psychiatric hospitals on patients with late-life depression (aged 55 to 87 years, N = 73). MRI data on white matter hyperintensities were available in 52 patients. Possible risk factors for apathy post-ECT were determined using regression analyses. RESULTS: After treatment with ECT, 52.0% (26/50) of the depression remitters still suffered from clinically relevant apathy symptoms. In the entire cohort, more patients remained apathetic (58.9%) than depressed (31.5%). Presence of apathy post-ECT was not associated with higher age, use of benzodiazepines, or severity of apathy and depression at baseline. Less response in depressive symptomatology after ECT predicted post-treatment apathy. The presence of vascular disease, diabetes mellitus and smoking, and white matter hyperintensities in the brain was not associated with post-treatment apathy. CONCLUSIONS: Apathy may perpetuate in individual patients, despite remission of depressive symptoms. In this cohort of patients with late-life depression, post-ECT apathy is not associated with white matter hyperintensities.

2.
Ann Surg Oncol ; 22(2): 552-6, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25155395

RESUMO

BACKGROUND: Locally advanced rectal cancer is customarily treated with neoadjuvant chemoradiotherapy (CRT) followed by a total mesorectal excision. During the course of CRT, previously non-detectable distant metastases can appear. Therefore, a restaging CT scan of the chest and abdomen was performed prior to surgery. The aim of this study was to determine the frequency of a change in treatment strategy after this restaging CT scan. METHODS: Patients treated with neoadjuvant CRT for locally advanced rectal cancer between January 2003 and July 2013 were included retrospectively. To determine the value of the restaging CT scan, the surgical treatment as planned before CRT was compared with the treatment ultimately received. RESULTS: A total of 153 patients (91 male) were eligible, and median age was 62 (32-82) years. The restaging CT scan revealed the presence of distant metastases in 19 patients (12.4, 95 % confidence interval [CI] 7.0-17.8). In 17 patients (11.1, 95 % CI 6.1-16.1), a change in treatment strategy occurred due to the detection of metastases with a restaging CT scan. CONCLUSION: A restaging CT scan after completion of neoadjuvant CRT may detect newly developed metastases and consequently alter the initial treatment strategy. This study demonstrated the added value of the restaging CT scan prior to surgery.


Assuntos
Neoplasias Retais/diagnóstico , Neoplasias Retais/terapia , Adulto , Idoso , Idoso de 80 Anos ou mais , Quimiorradioterapia Adjuvante , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Terapia Neoadjuvante , Estadiamento de Neoplasias , Neoplasias Retais/diagnóstico por imagem , Neoplasias Retais/patologia , Reto/cirurgia , Estudos Retrospectivos , Tomografia Computadorizada por Raios X
3.
J Prev Alzheimers Dis ; 11(1): 38-47, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38230715

RESUMO

BACKGROUND: Longitudinal changes in volumetric MRI outcome measures have been shown to correlate well with longitudinal changes in clinical instruments and have been widely used as biomarker outcomes in clinical trials for Alzheimer's disease (AD). While instances of discordant findings have been noted in some trials, especially the recent amyloid-removing therapies, the overall relationship between treatment effects on brain atrophy and clinical outcomes, and how it might depend on treatment target or mechanism, clinical instrument or imaging variable is not yet clear. OBJECTIVE: To systematically assess the consistency and therapeutic class-dependence of treatment effects on clinical outcomes and on brain atrophy in published reports of clinical trials conducted in mild cognitive impairment (MCI) and/or AD. DESIGN: Quantitative review of the published literature. The consistency of treatment effects on clinical and brain atrophy outcomes was assessed in terms of statistical agreement with hypothesized equal magnitude effects (e.g., 30% slowing of both) and nominal directional concordance, as a function of therapeutic class. SETTING: Interventional randomized clinical trials. PARTICIPANTS: MCI or AD trial participants. INTERVENTION: Treatments included were those that involved ingestion or injection of a putatively active substance into the body, encompassing both pharmacological and controlled dietary interventions. MEASUREMENTS: Each trial included in the analysis reported at least one of the required clinical outcomes (ADAS-Cog, CDR-SB or MMSE) and at least one of the required imaging outcomes (whole brain, ventricular or hippocampal volume). RESULTS: Data from 35 trials, comprising 185 pairwise comparisons, were included. Overall, the 95% confidence bounds overlapped with the line of identity for 150/185 (81%) of the imaging-clinical variable pairs. The greatest proportion of outliers was found in trials of anti-amyloid antibodies that have been shown to dramatically reduce the level of PET-detectable amyloid plaques, for which only 13/33 (39%) of observations overlapped the identity line. A Deming regression calculated using all data points yielded a slope of 0.54, whereas if data points from the amyloid remover class were excluded, the Deming regression line had a slope of 0.92. Directional discordance of treatment effects was also most pronounced for the amyloid-removing class, and for comparisons involving ventricular volume. CONCLUSION: Our results provide a frame of reference for the interpretation of clinical and brain atrophy results from future clinical trials and highlight the importance of mechanism of action in the interpretation of imaging results.


Assuntos
Doença de Alzheimer , Disfunção Cognitiva , Humanos , Doença de Alzheimer/diagnóstico por imagem , Doença de Alzheimer/tratamento farmacológico , Doença de Alzheimer/patologia , Disfunção Cognitiva/patologia , Encéfalo , Hipocampo/patologia , Atrofia/patologia
4.
Eur J Clin Microbiol Infect Dis ; 31(6): 1195-201, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21983896

RESUMO

There are limitations on diagnostic methods to differentiate between active and latent tuberculosis (TB), and the prediction of latent progression to TB disease is yet complex. Traditionally, tuberculosis-specific host immune response was visualized using the tuberculin skin test. Nowadays, IFN-γ release assays (IGRA) provide a more specific and sensitive tool, by which exposure to Mtb could be determined. However, the merit of IGRA aids in diagnosing active TB is yet unclear. We adapted IGRA for use in mice, and quantifying bead-based flow cytometry techniques were used to assess cytokine profiles during the course of untreated infection and to investigate the value of IGRA and cytokines as biomarkers for therapy response. High variability of IGRA results during progression of active TB infection related to various phases of infection was obtained. However, a significant decrease in IGRA results and in levels of IFN-γ, IL-17, IP-10 or MIG was observed and appeared to be associated with successful therapy. This outcome does not support the value of IGRA to accurately diagnose active TB or to monitor infection progression. However, IGRA proved to be a useful biomarker to monitor therapy success. In addition, different cytokines might serve as biomarkers.


Assuntos
Antituberculosos/administração & dosagem , Citocinas/análise , Citocinas/sangue , Monitoramento de Medicamentos/métodos , Testes de Liberação de Interferon-gama/métodos , Tuberculose/diagnóstico , Tuberculose/tratamento farmacológico , Animais , Sangue/imunologia , Feminino , Citometria de Fluxo/métodos , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Sistema Respiratório/imunologia , Tuberculose/imunologia
5.
Insights Imaging ; 12(1): 188, 2021 Dec 18.
Artigo em Inglês | MEDLINE | ID: mdl-34921657

RESUMO

BACKGROUND: Although promising results have been reported for Magnetic Resonance image-guided High-Intensity Focused Ultrasound (MR-HIFU) treatment of uterine fibroids, this treatment is not yet widely implemented in clinical practice. During the implementation of a new technology, lessons are learned and an institutional learning-curve often has to be completed. The primary aim of our prospective cohort study was to characterize our learning-curve based on our clinical outcomes. Secondary aims included identifying our lessons learned during implementation of MR-HIFU on a technical, patient selection, patient counseling, medical specialists and organizational level. RESULTS: Our first seventy patients showed significant symptom reduction and improvement of quality of life at 3, 6 and 12 months after MR-HIFU treatment compared to baseline. After the first 25 cases, a clear plateau phase was reached in terms of failed treatments. The median non-perfused volume percentage of these first 25 treatments was 44.6% (range: 0-99.7), compared to a median of 74.7% (range: 0-120.6) for the subsequent treatments. CONCLUSIONS: Our findings describe the learning-curve during the implementation of MR-HIFU and include straightforward suggestions to shorten learning-curves for future users. Moreover, the lessons we learned on technique, patient selection, patient counseling, medical specialists and organization, together with the provided supplements, may be of benefit to other institutions aiming to implement MR-HIFU treatment of uterine fibroids. Trial registration ISRCTN14634593. Registered January 12, 2021-Retrospectively registered, https://www.isrctn.com/ISRCTN14634593 .

7.
Int J Immunopathol Pharmacol ; 22(3): 723-34, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19822089

RESUMO

To evaluate novel approaches for tuberculosis (TB) diagnostics and treatment, well-validated animal TB models are needed. Especially the emergence and spread of drug resistant TB requires innovative therapy and accurate parameters for monitoring success or failure of therapy. We developed a TB model in BALB/c mice, in which Mycobacterium tuberculosis (Mtb) infection was induced through the natural respiratory route, mimicking human TB infection. The lung showed a mild inflammatory infiltrate consisting of granulomas in the first phase of infection, followed by progressive increase of pneumonic lesions resulting in extensive lung consolidation in the chronic phase. Dissemination to the extra-pulmonary sites was observed. The model was validated in terms of therapeutic outcome. The 26-week standard therapy administered in human pharmacokinetic-equivalent doses, resulted in complete elimination of Mtb in all infected organs, without relapse of infection in the post-treatment period. However, a 13-week therapy, simulating patient non-adherence resulted in relapse of infection. In our quest to find biomarkers for monitoring success or failure of therapy, the concentrations of various cytokines in serum and lung, determined by cytometric bead array (CBA), were evaluated in relation to the in situ cytokine expression in the lung, assessed by immunohistochemistry. The level of IFN-gamma concentration in serum increased with infection progression, and decreased during effective therapy, and as such appeared to be an appropriate immunological parameter for success or failure of therapy. Relapse of infection, after inappropriate therapy, manifested as an increase in the serum IFN-gamma concentration.


Assuntos
Antituberculosos/administração & dosagem , Biomarcadores/sangue , Interferon gama/sangue , Pulmão/imunologia , Mycobacterium tuberculosis/imunologia , Tuberculose Pulmonar/diagnóstico , Animais , Modelos Animais de Doenças , Progressão da Doença , Esquema de Medicação , Monitoramento de Medicamentos , Feminino , Técnica Indireta de Fluorescência para Anticorpo , Humanos , Pulmão/microbiologia , Pulmão/patologia , Camundongos , Camundongos Endogâmicos BALB C , Cooperação do Paciente , Valor Preditivo dos Testes , Recidiva , Reprodutibilidade dos Testes , Fatores de Tempo , Resultado do Tratamento , Tuberculose Pulmonar/imunologia , Tuberculose Pulmonar/microbiologia , Tuberculose Pulmonar/terapia
8.
Haemophilia ; 14(6): 1222-8, 2008 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-18479427

RESUMO

Protein S (PS) is an extensively studied protein with an important function in the down-regulation of thrombin generation. Because of the presence of a pseudogene and two different forms of PS in plasma, a bound and a free form, it is one of the most difficult thrombophilias to study. A deficiency of PS predisposes subjects to (recurrent) venous thromboembolism (VTE) and foetal loss. However, the conundrum of diagnosing PS deficiency has led to conflicting reports of PS as a risk factor for VTE. In this review, we aim to present a clinical perspective of PS deficiency.


Assuntos
Proteínas Sanguíneas/genética , Complicações Hematológicas na Gravidez/genética , Deficiência de Proteína S/genética , Proteína S/metabolismo , Tromboembolia Venosa/etiologia , Adulto , Idade de Início , Anticoagulantes/administração & dosagem , Testes de Coagulação Sanguínea , Anticoncepcionais Orais Hormonais , Contraindicações , Terapia de Reposição de Estrogênios , Reações Falso-Positivas , Feminino , Heterozigoto , Humanos , Imunoensaio , Recém-Nascido , Masculino , Pessoa de Meia-Idade , Mutação , Reação em Cadeia da Polimerase/métodos , Gravidez , Trimestres da Gravidez , Proteína S/genética , Deficiência de Proteína S/diagnóstico , Deficiência de Proteína S/fisiopatologia , Recidiva , Fatores de Risco , Trombofilia/genética , Tromboembolia Venosa/tratamento farmacológico
9.
Sci Rep ; 7(1): 9685, 2017 08 29.
Artigo em Inglês | MEDLINE | ID: mdl-28852152

RESUMO

Resting-state functional connectivity patterns are highly stable over time within subjects. This suggests that such 'functional fingerprints' may have strong genetic component. We investigated whether the functional (FC) or effective (EC) connectivity patterns of one monozygotic twin could be used to identify the co-twin among a larger sample and determined the overlap in functional fingerprints within monozygotic (MZ) twin pairs using resting state magnetoencephalography (MEG). We included 32 cognitively normal MZ twin pairs from the Netherlands Twin Register who participate in the EMIF-AD preclinAD study (average age 68 years). Combining EC information across multiple frequency bands we obtained an identification rate over 75%. Since MZ twin pairs are genetically identical these results suggest a high genetic contribution to MEG-based EC patterns, leading to large similarities in brain connectivity patterns between two individuals even after 60 years of life or more.


Assuntos
Encéfalo/fisiologia , Conectoma , Magnetoencefalografia , Gêmeos Monozigóticos , Feminino , Humanos , Masculino , Países Baixos
10.
Biochim Biophys Acta ; 1138(4): 318-26, 1992 Apr 14.
Artigo em Inglês | MEDLINE | ID: mdl-1532911

RESUMO

In an experimental model of unilateral pneumonia caused by Klebsiella pneumoniae in rats we investigated whether intravenous administration of liposomes with prolonged blood circulation time resulted in significant localization of liposomes in infected lung tissue. Liposomes (100 nm) composed of hydrogenated phosphatidylinositol:hydrogenated phosphatidylcholine:cholesterol (molar ratio, 1:10:5) radiolabeled with gallium-67-deferoxamine showed relatively long blood circulation time. The degree of localization of these long circulating liposomes in the infected left lung was significantly higher compared to that of localization of 110 nm egg phosphatidylglycerol:egg phosphatidylcholine:cholesterol (molar ratio, 1:10:5) liposomes which exhibited relatively short blood circulation time. At 16 h after administration of the long circulating liposomes (when 10% of the injected dose was still present in the bloodstream) localization of liposomes in the infected left lung was increased up to 10-fold compared to the left lung of uninfected rats, and appeared to be highly correlated with the intensity of the infection. In the uninfected right lung the localization of long circulating liposomes was not increased. The degree of localization of liposomes in the infected tissue is dependent on the residence time of liposomes in the blood compartment. The extent of localization of long circulating liposomes in infected tissue appeared to be dependent on the liposomal dose administered.


Assuntos
Infecções por Klebsiella/metabolismo , Lipossomos/farmacocinética , Pulmão/metabolismo , Pneumonia/metabolismo , Animais , Modelos Animais de Doenças , Feminino , Infecções por Klebsiella/microbiologia , Klebsiella pneumoniae/crescimento & desenvolvimento , Pulmão/microbiologia , Pneumonia/microbiologia , Ratos , Ratos Endogâmicos , Organismos Livres de Patógenos Específicos , Distribuição Tecidual
11.
Clin Cancer Res ; 4(1): 111-5, 1998 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-9516959

RESUMO

The introduction of long-circulating liposomes sterically stabilized by surface coating with polyethylene glycol has expanded the potential for drug targeting to tumors. In recent clinical studies, evidence of significant antitumor activity has been obtained with the industrially prepared formulation of long-circulating polyethylene glycol-coated liposomes containing doxorubicin, referred to as DOXIL. Previous studies performed in rats showed that doxorubicin-containing liposomes can exert major toxic effects on the liver macrophage population for a considerable period of time; a strong impairment of phagocytic function and even a substantial depletion of the liver macrophage populations were observed. In the present study, the phagocytic function of the mononuclear phagocyte system (MPS) after administration of DOXIL at a clinically relevant dosage schedule was evaluated in rats. Phagocytic function of the MPS was assessed by determining bacterial blood clearance capacity. The observations reported herein show that DOXIL is fairly well tolerated regarding bacterial blood clearance capacity of the MPS when administered in a regimen that resembles the clinical setting closely. This outcome has important implications with regard to the clinical utility of the liposomal drug, especially in the restricted context of immunocompromised cancer patients who easily develop systemic infections and should not be confronted with a therapy-induced reduction of the bacterial blood clearance capacity of the MPS.


Assuntos
Antibióticos Antineoplásicos/administração & dosagem , Bacteriemia/imunologia , Doxorrubicina/administração & dosagem , Fagócitos/efeitos dos fármacos , Animais , Doxorrubicina/toxicidade , Portadores de Fármacos , Feminino , Lipossomos , Fagócitos/imunologia , Ratos
12.
Eur J Obstet Gynecol Reprod Biol ; 91(2): 165-7, 2000 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-10869790

RESUMO

We present the course of six gynecological patients who underwent surgical intervention because of a solitary metastasis. After a considerable follow-up period five patients are alive without evidence of disease and with a good quality of life. Metastasectomy should play a role in the management of gynecologic malignancies.


Assuntos
Neoplasias dos Genitais Femininos/terapia , Metástase Neoplásica/terapia , Músculos Abdominais/cirurgia , Idoso , Neoplasias do Endométrio/terapia , Feminino , Humanos , Pessoa de Meia-Idade , Neoplasias Ovarianas/terapia , Períneo/cirurgia , Qualidade de Vida , Neoplasias do Colo do Útero/terapia , Neoplasias Vaginais/secundário , Neoplasias Vaginais/cirurgia
15.
Int J Tuberc Lung Dis ; 15(11): 1478-84, i, 2011 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22008760

RESUMO

BACKGROUND: In the search for new anti-tuberculosis drugs, numerous potential drugs are being screened in vitro. In animal models, promising new anti-tuberculosis drugs are assessed in terms of toxic side effects and comparative therapeutic efficacy. Mice are frequently used and experimental infections are established in different ways. OBJECTIVE: To investigate to what extent the route of Mycobacterium tuberculosis inoculation is a determinant in the pathogenesis of tuberculosis (TB) and the therapeutic outcome. Results will contribute to insight into the translational value of TB models used for preclinical studies. DESIGN: TB in mice was established through intratracheal or intravenous mycobacterial inoculation. The efficacy of a 26-week treatment regimen was evaluated, including assessment of relapse of infection 13 weeks post-treatment. RESULTS: It was shown that the course of TB and the therapeutic response, in terms of histopathological characteristics and mycobacterial load, in lungs and extra- pulmonary organs is substantially different and dependent on the route of infection applied and the inoculum size used. CONCLUSION: When evaluating the comparative therapeutic potential of novel anti-tuberculosis drugs or drug treatment schedules investigated in different studies, it should be noted that the route of infection applied and the inoculum size used influence the course of murine TB and the therapeutic response to the standard first- line anti-tuberculosis drug regimen.


Assuntos
Antituberculosos/farmacologia , Modelos Animais de Doenças , Avaliação Pré-Clínica de Medicamentos/métodos , Mycobacterium tuberculosis/efeitos dos fármacos , Tuberculose/tratamento farmacológico , Animais , Feminino , Exposição por Inalação , Injeções Intravenosas , Fígado/efeitos dos fármacos , Fígado/microbiologia , Fígado/patologia , Pulmão/efeitos dos fármacos , Pulmão/microbiologia , Pulmão/patologia , Camundongos , Camundongos Endogâmicos BALB C , Mycobacterium tuberculosis/crescimento & desenvolvimento , Mycobacterium tuberculosis/patogenicidade , Recidiva , Reprodutibilidade dos Testes , Baço/efeitos dos fármacos , Baço/microbiologia , Baço/patologia , Fatores de Tempo , Tuberculose/diagnóstico , Tuberculose/microbiologia , Tuberculose/patologia , Tuberculose Pulmonar/tratamento farmacológico , Tuberculose Pulmonar/microbiologia
16.
J Thromb Haemost ; 8(6): 1193-200, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-20230415

RESUMO

BACKGROUND: Absolute risks of venous thromboembolism (VTE) in protein S-, protein C-, or antithrombin-deficient subjects are mainly based on retrospective data. Screening asymptomatic relatives of these patients is disputed, though studies addressing this issue have yet to be conducted. METHODS: We prospectively followed 382 relatives of 84 probands. Participants were assessed for other thrombophilic defects and occurrence of exogenous risk factors (i.e. surgery/trauma/immobilization, malignancies, use of systemic estrogens, and pregnancy/puerperium). After screening, deficient subjects were advised to use thromboprophylaxis during exogenous risk factors; use of oral contraceptives was discouraged. RESULTS: Overall annual incidence of VTE was 1.53% (95% CI, 1.00-2.34) in deficient vs. 0.29% (0.13-0.64) in non-deficient relatives; adjusted hazard ratio, 7.0 (95% CI, 2.7-18.0). Annual incidence of unprovoked VTE was 0.95% in deficient vs. 0.05% in non-deficient subjects; age-adjusted hazard ratio, 22.3 (P = 0.003). In contrast, annual incidence of provoked VTE was 0.58% vs. 0.24%; age-adjusted hazard ratio, 2.8 (P = 0.08). Fifty-five (37%) deficient and 80 (34%) non-deficient subjects experienced 91 and 143 exogenous risk factors, respectively, during which six vs. five VTEs (6.6% vs 3.5% per risk-period) occurred, despite the higher compliance with recommended thromboprophylaxis use in deficient (51%) vs. non-deficient (22%) subjects. In deficient subjects all provoked VTEs occurred when thromboprophylaxis was not used. CONCLUSIONS: Protein S, protein C or antithrombin deficiencies confer high absolute risk of VTE. Screening and subsequent augmentation of thromboprophylaxis use may result in reduction of provoked VTE, whereas risk of unprovoked VTE could not be affected by screening.


Assuntos
Deficiência de Proteína C/genética , Deficiência de Proteína S/genética , Trombofilia/genética , Tromboembolia Venosa/epidemiologia , Humanos , Estudos Prospectivos , Fatores de Risco , Tromboembolia Venosa/diagnóstico
17.
Eur J Surg Oncol ; 34(4): 469-75, 2008 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-17442529

RESUMO

BACKGROUND: Surgical resection remains the most effective therapy for metastatic colorectal cancer confined to the liver, although the extrahepatic recurrence rate is high. AIM OF THE STUDY: To develop a mammal model in order to investigate by which mechanisms liver surgery affects distant tumour recurrence. METHODS: In this animal study the effect of partial hepatectomy (phX) on the development of tumour noduli in the lungs was evaluated. CC531 rat colon carcinoma cells were inoculated i.v. 24h before, during or 24h after surgery. Rat serum was obtained at different time-points after phX and added to in vitro CC531 cell cultures. Finally, phX was compared with an ileum resection (ilX). RESULTS: phX leads to increased tumour noduli in the lungs, compared to Sham operation (p=0.002), but only when performed directly before the injection of tumour cells and not when performed 24h before or after the inoculation. Comparable results were obtained for ilX. No growth stimulation of tumour cells after incubation with rat serum, obtained at different time-points after phX, could be detected in vitro. CONCLUSION: Not only phX, but also surgery, in general promotes distant tumour recurrence exerting the effect during the early phase of tumour cell adhesion and not during tumour outgrowth.


Assuntos
Adenocarcinoma/imunologia , Neoplasias Colorretais/cirurgia , Neoplasias Hepáticas/cirurgia , Neoplasias Pulmonares/imunologia , Adenocarcinoma/secundário , Animais , Adesão Celular , Linhagem Celular Tumoral , Neoplasias Colorretais/patologia , Modelos Animais de Doenças , Hepatectomia , Peptídeos e Proteínas de Sinalização Intercelular/biossíntese , Neoplasias Hepáticas/secundário , Regeneração Hepática/imunologia , Neoplasias Pulmonares/secundário , Masculino , Metástase Neoplásica , Transplante de Neoplasias , Ratos , Ratos Wistar , Receptores de Fatores de Crescimento/biossíntese
18.
J Antimicrob Chemother ; 59(3): 507-16, 2007 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-17289765

RESUMO

OBJECTIVES: The effect of ceftazidime dosing increments and frequency of dosing on the selection of ceftazidime-resistant Enterobacter cloacae in the intestine was studied in rats, during treatment of a pulmonary infection caused by Klebsiella pneumoniae. METHODS: Rats with pulmonary infection (n = 10 per group) received therapy with doses of ceftazidime at 3.1 to 400 mg/kg per day at a frequency of every 6,12 or 24 h for 18 days, starting 24 h after bacterial inoculation of the lung. Emergence of resistance in intestinal E. cloacae was monitored by culturing fresh stool specimens at days 0, 8, 15, 22, 29, 36 and 43 on agar plates with (6.4 mg/L) and without ceftazidime. Pharmacodynamic indices and time within the mutant selection window (MSW) were assessed in infected rats for each regimen. Ceftazidime-resistant E. cloacae mutants were characterized by determination of the beta-lactamase activity under cefoxitin-induced and non-induced conditions. RESULTS: A reduction of intestinal ceftazidime-susceptible E. cloacae was observed and showed a significant correlation with the fAUC/MIC at days 8, 15 and 22 and with the fCmax on days 8, 15, 22, 29 and 36. More rats treated with 12-25 and 50-100 mg/kg per day every 6 h were found colonized with ceftazidime-resistant E. cloacae mutants than animals treated every 12 h or every 24 h. The proportion of rats colonized with ceftazidime-resistant E. cloacae mutants at days 15, 36 and 43 correlated with the time during which ceftazidime plasma concentrations were within the boundaries of the MSW. Only at day 15 was a correlation demonstrated between the fCmax and significantly fewer rats colonized with ceftazidime-resistant E. cloacae. Ceftazidime-resistant E. cloacae mutants (MIC >or= 128 mg/L) were characterized as stable derepressed mutants. CONCLUSIONS: Colonization with stable derepressed ceftazidime-resistant E. cloacae mutants particularly occurred when rats were exposed to moderate doses of ceftazidime (12-25 or 50-100 mg/kg per day) administered every 6 h. Emergence of resistance was correlated with time within the MSW.


Assuntos
Antibacterianos/administração & dosagem , Ceftazidima/administração & dosagem , Enterobacter cloacae/efeitos dos fármacos , Infecções por Enterobacteriaceae/tratamento farmacológico , Intestinos/microbiologia , Pneumopatias/tratamento farmacológico , Animais , Ceftazidima/sangue , Esquema de Medicação , Farmacorresistência Bacteriana , Genótipo , Masculino , Testes de Sensibilidade Microbiana , Ratos
19.
Br J Cancer ; 95(11): 1497-503, 2006 Dec 04.
Artigo em Inglês | MEDLINE | ID: mdl-17088916

RESUMO

We hypothesise that reactive oxygen species (ROS) released from activated polymorphonuclear leucocytes during surgery play a crucial role in enhanced tumour recurrence seen after surgery. Therefore, the effect of ROS on adhesion of tumour cells to microvascular endothelium in a reproducible human in vitro model was studied. Preincubation of microvascular endothelial cells with the superoxide anion producing xanthine-xanthine oxidase complex significantly increased adhesion of the human colon carcinoma cells HT29 (167% vs control, P < 0.01), Caco2 (164% vs control, P < 0.01) and of the pancreas carcinoma cells PanC1 (180% vs control, P < 0.01). Addition of the antioxidant enzymes superoxide dismutase or catalase significantly decreased tumour cell adhesion (P < 0.01). Exposure of endothelial cells to superoxide anions increased the apoptotic rate to 7.9 times the normal rate. Additionally, exposure increased expression of the endothelial adhesion molecules E-Selectin, ICAM-1, and VCAM-1 of maximally 170% vs control (P < 0.01). In conclusion, this study shows that superoxide anions promote the adherence of tumour cells to the microvasculature by inducing endothelial apoptosis that subsequently induces the expression of various adhesion molecules for tumour cells. This indicates that by tackling the production of ROS preventing tumour recurrence at distant sites might be feasible.


Assuntos
Adenocarcinoma/metabolismo , Neoplasias do Colo/metabolismo , Metástase Neoplásica/patologia , Neoplasias Pancreáticas/metabolismo , Superóxidos/metabolismo , Apoptose/fisiologia , Adesão Celular/fisiologia , Moléculas de Adesão Celular/metabolismo , Linhagem Celular Tumoral , Endotélio Vascular/metabolismo , Humanos
20.
Antimicrob Agents Chemother ; 45(2): 464-70, 2001 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-11158742

RESUMO

Long-circulating liposomes (LCL) may be used as targeted antimicrobial drug carriers as they localize at sites of infection. As a result, LCL-encapsulated gentamicin (LE-GEN) has demonstrated superior antibacterial activity over the free drug in a single-dose study of immunocompetent rats with Klebsiella pneumoniae pneumonia. In the present study, the therapeutic efficacy of LE-GEN was evaluated by monitoring rat survival and bacterial counts in blood and lung tissue in clinically relevant models, addressing the issue of impaired host defense and low bacterial antibiotic susceptibility. The results show that in immunocompetent rats infected with the high-GEN-susceptibility K. pneumoniae strain, a single dose of LE-GEN is clearly superior to an equivalent dose of free GEN. Yet complete survival can also be obtained with multiple doses of free GEN. In leukopenic rats infected with the high-GEN-susceptible K. pneumoniae strain, free GEN at the maximum tolerated dose (MTD) was needed to obtain survival. However, with the addition of a single dose of LE-GEN to free-GEN treatment, complete survival can be obtained using a sevenfold-lower cumulative amount of GEN than with free-GEN treatment alone. In leukopenic rats infected with low-GEN-susceptible K. pneumoniae cells, free GEN at the MTD did not result in survival. The use of LE-GEN is needed for therapeutic success. Increasing LE-GEN bilayer fluidity resulted in an increased GEN release from the liposomes and hence improved rat survival, thus showing the importance of the liposome lipid composition for therapeutic efficacy. These results warrant further clinical studies of liposomal formulations of aminoglycosides in immunocompromised patients with severe infections.


Assuntos
Antibacterianos/uso terapêutico , Gentamicinas/uso terapêutico , Infecções por Klebsiella/tratamento farmacológico , Klebsiella pneumoniae/efeitos dos fármacos , Animais , Antibacterianos/administração & dosagem , Antibacterianos/farmacocinética , Contagem de Colônia Microbiana , Portadores de Fármacos , Feminino , Gentamicinas/administração & dosagem , Gentamicinas/farmacocinética , Infecções por Klebsiella/microbiologia , Leucopenia/imunologia , Leucopenia/microbiologia , Lipossomos , Pulmão/microbiologia , Ratos , Ratos Endogâmicos , Análise de Sobrevida
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