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1.
Artigo em Inglês | MEDLINE | ID: mdl-39037917

RESUMO

BACKGROUND: Hypothesizing that early treatment yields improved prognosis, we aimed to investigate how the timing of immunosuppressive treatment relates to interstitial lung disease (ILD) development and the course of pulmonary function in systemic sclerosis (SSc). METHODS: A cohort was created using data from the EUSTAR database and Nijmegen Systemic Sclerosis cohort, including adult patients who started their first immunosuppressive treatment (ie mycophenolate mofetil, methotrexate, cyclophosphamide, tocilizumab or rituximab) after SSc diagnosis, and no signs of ILD on high-resolution CT. ILD-free survival and the course of forced vital capacity % predicted (ppFVC) were assessed for up to 5 years follow-up comparing patients who started early (disease duration ≤ 3 years) vs late with immunosuppression. RESULTS: 1052 patients met the eligibility criteria. The early treatment group (n = 547, 52%) showed a higher prevalence of male sex, diffuse cutaneous subtype (53.1% vs 36.5%), and anti-topoisomerase-I antibody (ATA, 51.1% vs 42.7%). Most patients were treated with methotrexate (60.1%), whereas only a few patients were treated with biologicals (1.7%). The incidence of ILD was 46.6% after mean (SD) 3.6(1.4) years; the hazards ratio for ILD in the early treatment group was 1.13 (95% CI: 0.93-1.38) after adjustment for confounders. PpFVC trajectories were comparable between groups. CONCLUSION: Our findings did not confirm a preventive role of early initiation of immunosuppressive therapy vs late initiation on ILD development. However, our findings should be interpreted with caution, considering the high inflammatory, ATA-positive enriched nature of the cohort, confounding by indication, and very few patients were treated with biologicals.

2.
Eur J Intern Med ; 125: 104-110, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38599922

RESUMO

BACKGROUND: The anti-Nucleolar Organizer Region 90 antibodies (NOR90) are rare antinuclear antibodies (ANA) reported in systemic sclerosis (SSc). Especially due to low prevalence, the clinical relevance of NOR90 in SSc remains uncertain. OBJECTIVES: To analyze the clinical associations of NOR90 in patients with SSc in a multicentric cohort. METHODS: Post-hoc, cross-sectional study of prospectively collected data from the European Scleroderma Trials and Research (EUSTAR) database, with additional information on NOR90. Further, we performed a systematic literature search, using the terms "systemic sclerosis" and "NOR90" across three databases: Medline via PubMed, Scopus, and Thomson Reuters' Web of Science Core Collection, from inception to November 1st, 2023. RESULTS: Overall, 1318 patients with SSc were included (mean age 58.3 ± 13.7 years, 81.3 % female), of whom 44 (3.3 %) were positive for NOR90. Of these, 32 were also positive for one of the SSc-criteria antibodies: 9/44 (20.5 %) for anti-topoisomerase I, 18/42 (42.9 %) for anti-centromere, and 5/40 (12.5 %) for anti-RNA polymerase III. NOR90-positive patients were more frequently female, had lower modified Rodnan skin score (mRSS), and lower prevalence of upper and lower gastrointestinal (GI) symptoms compared to NOR90-negative patients. In multivariable analysis, NOR90 remained significantly associated with lower mRSS and less frequent GI symptoms. The literature search identified 17 articles, including a total number of 87 NOR90-positive out of 3357 SSc patients, corresponding to an overall prevalence of 2.6 %. CONCLUSION: To our best knowledge, this is the largest SSc cohort tested for NOR90 to date, confirming the NOR90 prevalence in SSc patients is around 3 %.


Assuntos
Anticorpos Antinucleares , Escleroderma Sistêmico , Humanos , Escleroderma Sistêmico/imunologia , Anticorpos Antinucleares/sangue , Feminino , Pessoa de Meia-Idade , Masculino , Idoso , Estudos Transversais , Adulto , Europa (Continente) , DNA Topoisomerases Tipo I/imunologia , Relevância Clínica
3.
Respir Res ; 25(1): 138, 2024 Mar 23.
Artigo em Inglês | MEDLINE | ID: mdl-38521926

RESUMO

BACKGROUND: The prognostic and theragnostic role of histopathological subsets in systemic sclerosis interstitial lung disease (SSc-ILD) have been largely neglected due to the paucity of treatment options and the risks associated with surgical lung biopsy. The novel drugs for the treatment of ILDs and the availability of transbronchial cryobiopsy provide a new clinical scenario making lung biopsy more feasible and a pivotal guide for treatment. The aim of our study was to investigate the usefulness of lung biopsy in SSc ILD with a systematic literature review (SLR). METHODS: PubMed, Embase and Cochrane databases were searched up to June 30, 2023. Search terms included both database-specific controlled vocabulary terms and free-text terms relating to lung biopsy and SSc-ILD diagnostic and prognosis. The SLR was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA). Studies were selected according to the PEO (population, exposure, and outcomes) framework and Quality assessment of diagnostic accuracy studies (QUADAS) were reported. RESULTS: We selected 14 articles (comprising 364 SSc-ILD patients). The paucity and heterogeneity of the studies prevented a systematic analysis. Diffuse cutaneous SSc was present in 30-100% of cases. Female predominance was observed in all studies (ranging from 64 to 100%). Mean age ranged from 42 to 64 years. Mean FVC was 73.98 (+/-17.3), mean DLCO was 59.49 (+/-16.1). Anti-Scl70 antibodies positivity was detected in 33% of cases (range: 0-69.6). All patients underwent surgical lung biopsies, and multiple lobes were biopsied in a minority of studies (4/14). Poor HRCT-pathologic correlation was reported with HRCT-NSIP showing histopathologic UIP in up to 1/3 of cases. Limited data suggest that SSc-UIP patients may have a worse prognosis and response to immunosuppressive treatment compared to other histopathologic patterns. CONCLUSIONS: The data from this SLR clearly show the paucity and heterogeneity of the studies reporting lung biopsy in SSc ILD. Moreover, they highlight the need for further research to address whether the lung biopsy can be helpful to refine prognostic prediction and guide therapeutic choices.

4.
MethodsX ; 10: 102218, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37292241

RESUMO

Simulation of vegetation fires very often resorts to fire-behavior models that need fuel models as input. The lack of fuel models is a common problem for researchers and fire managers because its quality depends on the quality/availability of data. In this study we present a method that combines expert- and research-based knowledge with several sources of data (e.g. satellite and fieldwork) to produce customized fuel models maps. Fuel model classes are assigned to land cover types to produce a basemap, which is then updated using empirical and user-defined rules. This method produces a map of surface fuel models as detailed as possible. It is reproducible, and its flexibility relies on juxtaposing independent spatial datasets, depending on their quality or availability. This method is developed in a ModelBuilder/ArcGis toolbox named FUMOD that integrates ten sub-models. FUMOD has been used to map the Portuguese annual fuel models grids since 2019, supporting regional fire risk assessments and suppression decisions. Datasets, models and supplementary files are available in a repository (https://github.com/anasa30/PT_FuelModels). •FUMOD is a flexible toolbox with ten sub-models included that maps updated Portuguese fuel models.

5.
Reumatismo ; 72(4): 228-246, 2021 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-33677950

RESUMO

The term pulmonary arterial hypertension (PAH) identifies a heterogeneous group of diseases characterized by a progressive increase in pulmonary arterial resistance (PVR), which causes a significant burden in terms of quality of life, right heart failure and premature death. The pathogenesis of PAH is not completely clear: the remodeling of the small pulmonary vessels is crucial, causing an increase in the resistance of the pulmonary circle. Its diagnosis is based on cardiac catheterization of the right heart. According to the present hemodynamic definition of pulmonary hypertension (PH) proposed by the Guidelines of the European Society of Cardiology/European Respiratory Society (ESC-ERS), the mean pulmonary arterial pressure (mPAP) values are ≥25 mmHg. In case of PAH, apart from an mPAP value ≥25 mmHg, patients must have a >3 Wood units increase in PVR and normal pressure values of the left heart. PH is a pathophysiological condition observed in more than 40 different diseases, while PAH is a primary disease of the pulmonary bloodstream potentially treatable with specific drugs. PAH is a severe complication of systemic sclerosis (SSc) affecting about 10% of the patients. Due to the devastating nature of SSc-PAH, there is a clear need to systematically adopt appropriate screening programs. In fact, despite awareness of the negative impact of SSc-PAH on quality of life and survival, as well as on the severity of lung function, at the moment standardized and shared guidelines and/or screening programs for the diagnosis and the subsequent early treatment of PAH in SSc are not available. The aim of the present paper is to highlight the lights and shadows of SSc-PAH, unraveling the unmet clinical needs on this topic with a proposal of clinical-diagnostic and therapeutic guidelines.


Assuntos
Hipertensão Pulmonar , Hipertensão Arterial Pulmonar , Escleroderma Sistêmico , Hemodinâmica , Humanos , Hipertensão Pulmonar/diagnóstico , Hipertensão Pulmonar/etiologia , Hipertensão Pulmonar/terapia , Qualidade de Vida
7.
Clin Rheumatol ; 39(1): 27-36, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31111363

RESUMO

INTRODUCTION: DeSScipher is the first European multicentre study on management of systemic sclerosis (SSc), and its observational trial 1 (OT1) evaluated the efficacy of different drugs for digital ulcer (DU) prevention and healing. The aim of this study was to assess current use of vasoactive/vasodilating agents for SSc-related DU in the expert centres by analysing the baseline data of the DeSScipher OT1. METHOD: Baseline characteristics of patients enrolled in the OT1 and data regarding DU were analysed. RESULTS: The most commonly used drugs, in both patients with and without DU, were calcium channel blockers (CCBs) (71.6%), followed by intravenous iloprost (20.8%), endothelin receptor antagonists (ERAs) (20.4%) and phosphodiesterase 5 (PDE-5) inhibitors (16.5%). Of patients, 32.6% with DU and 12.8% without DU received two drugs (p < 0.001), while 11.5% with DU and 1.9% without DU were treated with a combination of three or more agents (p < 0.001). Sixty-five percent of the patients with recurrent DU were treated with bosentan and/or sildenafil. However, 64 out of 277 patients with current DU (23.1%) and 101 (23.6%) patients with recurrent DU were on CCBs alone. CONCLUSIONS: Our study shows that CCBs are still the most commonly used agents for DU management in SSc. The proportion of patients on combination therapy was low, even in patients with recurrent DU: almost one out of four patients with current and recurrent DU was on CCBs alone. Prospective analysis is planned to investigate the efficacy of different drugs/drug combinations on DU healing and prevention. Key Points • The analysis of DeSScipher, the first European multicentre study on management of SSc, has shown that the most commonly used vasoactive/vasodilating drugs for DU were CCBs, followed by intravenous Iloprost, ERAs and PDE-5 inhibitors. • More than half of the patients with recurrent DU received bosentan and/or sildenafil. • However, the proportion of patients on combination therapy of more than one vasoactive/vasodilating drug was low and almost one out of four patients with current and recurrent DU was on CCBs alone.


Assuntos
Dedos/patologia , Escleroderma Sistêmico/tratamento farmacológico , Úlcera Cutânea/tratamento farmacológico , Vasodilatadores/uso terapêutico , Adulto , Idoso , Bosentana/uso terapêutico , Quimioterapia Combinada , Europa (Continente) , Feminino , Humanos , Iloprosta/uso terapêutico , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Escleroderma Sistêmico/diagnóstico , Citrato de Sildenafila/uso terapêutico , Úlcera Cutânea/diagnóstico , Resultado do Tratamento , Cicatrização/efeitos dos fármacos
9.
Math Med Biol ; 36(1): 1-53, 2019 03 14.
Artigo em Inglês | MEDLINE | ID: mdl-29346681

RESUMO

We address a non-linear programming problem to find the optimal scheme of dose fractionation in cancer radiotherapy. Using the LQ model to represent the response to radiation of tumour and normal tissues, we formulate a constrained non-linear optimization problem in terms of the variables number and sizes of the dose fractions. Quadratic constraints are imposed to guarantee that the damages to the early and late responding normal tissues do not exceed assigned tolerable levels. Linear constraints are set to limit the size of the daily doses. The optimal solutions are found in two steps: i) analytical determination of the optimal sizes of the fractional doses for a fixed, but arbitrary number of fractions n; ii) numerical simulation of a sequence of the previous optima for n increasing, and for specific tumour classes. We prove the existence of a finite upper bound for the optimal number of fractions. So, the optimum with respect to n is found by means of a finite number of comparisons amongst the optimal values of the objective function at the first step. In the numerical simulations, the radiosensitivity and repopulation parameters of the normal tissue are fixed, while we investigate the behaviour of the optimal solution for wide variations of the tumour parameters, relating our optima to real clinical protocols. We recognize that the optimality of hypo or equi-fractionated treatment schemes depends on the value of the tumour radiosensitivity ratio compared to the normal tissue radiosensitivity. Fast growing, radioresistant tumours may require particularly short optimal treatments.


Assuntos
Fracionamento da Dose de Radiação , Modelos Biológicos , Neoplasias/radioterapia , Neoplasias da Mama/patologia , Neoplasias da Mama/radioterapia , Proliferação de Células/efeitos da radiação , Sobrevivência Celular/efeitos da radiação , Simulação por Computador , Feminino , Humanos , Masculino , Conceitos Matemáticos , Neoplasias/patologia , Dinâmica não Linear , Neoplasias da Próstata/patologia , Neoplasias da Próstata/radioterapia , Tolerância a Radiação , Planejamento da Radioterapia Assistida por Computador/estatística & dados numéricos
10.
Clin Rheumatol ; 37(5): 1249-1255, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29470737

RESUMO

Iloprost (ILO) is employed intravenously for the treatment of severe Raynaud phenomenon (RP) and digital ulcers (DU) in systemic sclerosis (SSc). The aim of this study was to evaluate the safety and tolerability of the intravenous treatment with ILO in different phases of SSc. Eighty-one consecutive non-selected SSc patients, all on nifedipine, with moderate RP, treated with ILO infusion, were retrospectively evaluated. Patients were sub classified according to the edematous or fibrotic/atrophic cutaneous phase of the disease. ILO was infused with a progressive increase of the dosage up to the achievement of patient's tolerance, 1 day/week. In cases of slower infusion regimen due to adverse events (AE) at the beginning of the administration, patients received a lower dose of the drug (not possible to quantify precisely the final cumulative dosage). 16/81 SSc patients presented digital edema, 5 developed diarrhea, and 9 developed transient hypotension during the infusion at 20 ml/h that ameliorated when the drug was withdrawn. Moreover, 10/16 edematous patients experienced significant and painful digital swelling, unlike patients in the fibrotic group (p < 0.0001); 11/16 patients reported flushing and 7/16 headache, always controlled with dose tapering below 10 ml/h. In the atrophic/fibrotic phase patients (65/81), 10 developed diarrhea and 24 hypotension at infusion rate of 20 ml/h that led to temporary withdrawal of the drug. When ILO was restarted and kept below 10 ml/h, no side effects were experienced. 23/65 patients experienced flushing and 8/65 headache, all controlled with infusion reduction below 10 ml/h. In these patients, adverse events were significantly less frequent than in the edematous group (p = 0.023 and p = 0.008, respectively). Our data suggest that calcium channel blockers should be transitorily stopped while using ILO and that a pre-treatment approach might reduce or control adverse events. In patients with digital edema, ILO infusion should be carefully employed after the evaluation of patient's drug tolerance.


Assuntos
Iloprosta/efeitos adversos , Doença de Raynaud/tratamento farmacológico , Escleroderma Sistêmico/complicações , Úlcera Cutânea/tratamento farmacológico , Adulto , Diarreia/induzido quimicamente , Feminino , Dedos , Humanos , Iloprosta/uso terapêutico , Masculino , Angioscopia Microscópica , Pessoa de Meia-Idade , Doença de Raynaud/etiologia , Estudos Retrospectivos , Úlcera Cutânea/etiologia , Resultado do Tratamento
11.
J Scleroderma Relat Disord ; 2(2): 115-120, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-30569018

RESUMO

PURPOSE: There is a lack of a valid, definition for skin ulcers in SSc to be used in clinical trials. Our aim was to develop a consensus definition for SSc-skin ulcers based on the results of a systematic literature review (SLR) for skin ulcer definitions and expert opinion; and to evaluate its face validity, reliability and feasibility. METHODS: SLR for skin ulcer definitions was conducted using PubMed, Web of Science, and Cochrane library for articles published from inception to January 1st, 2016. SSc experts were to discuss the definitions' categories and vote for the relevant terms. Reliability of the definition were tested in a second expert meeting, seven SSc experts evaluated 7 SSc pts with skin lesions twice. Face validity and feasibility evaluated by sending out case report forms(CRFs) to 4 SSc experts, they were asked to use the definition in 5 pts each. RESULTS: A total of 3464 abstracts and titles were screened, and 446 articles were fully evaluated. Of these, 66 met eligibility criteria and skin ulcer definitions were extracted. SSc experts discussed, refined and voted on the consensus definition using nominal process. Kappa for inter-, intra-rater rater agreement was 0.51, 0.90 respectively. The mean time to decide if the lesion is an ulcer was 7.4 sec. All investigators endorsed the face validity of the new definition in the CRFs. CONCLUSION: Using a SLR and a nominal technique, we developed a preliminary consensus-based definition of SSc-skin ulcers. Face validity, feasibility and reliability were demonstrated for the developed definition.

12.
J Synchrotron Radiat ; 24(Pt 1): 312-322, 2017 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-28009573

RESUMO

The goal of this paper is to express simply the number of photons impinging on a target in the framework of accelerator-based Compton X-ray sources. From the basic kinematics of Compton sources, analytic formulas for the angular and the spectral fluxes are established as functions of the energy spread or/and the angular divergence of the electron and the laser beams. Their detailed predictions are compared with Monte Carlo simulations. These analytic expressions allow one to compute in a simple and precise way the X-ray flux in a given angular acceptance and a given energy bandwidth, knowing the characteristics of the incoming beams.

13.
Reumatismo ; 68(2): 109-11, 2016 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-27608801

RESUMO

Systemic sclerosis (SSc) is a connective tissue disease frequently associated with Raynaud's Phenomenon (RP). Among possible pharmacological treatments, phosphodiesterase 5 inhibitors are considered in cases of severe non -responsive RP. We present the case of a male SSc patient wh presented with critical finger ischemia and concomitant appearance of myocardial fibrosis after sudden interruption of sildenafil treatment.


Assuntos
Antirreumáticos/efeitos adversos , Cardiomiopatias/patologia , Dedos/irrigação sanguínea , Doença de Raynaud/tratamento farmacológico , Escleroderma Sistêmico/tratamento farmacológico , Citrato de Sildenafila/efeitos adversos , Síndrome de Abstinência a Substâncias , Antirreumáticos/uso terapêutico , Cardiomiopatias/etiologia , Humanos , Isquemia , Masculino , Pessoa de Meia-Idade , Miocárdio/patologia , Doença de Raynaud/complicações , Doença de Raynaud/patologia , Fatores de Risco , Escleroderma Sistêmico/complicações , Escleroderma Sistêmico/patologia , Citrato de Sildenafila/uso terapêutico , Fatores de Tempo
14.
Clin Rheumatol ; 35(1): 127-32, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26631100

RESUMO

The aim of this study was to evaluate in systemic sclerosis (SSc) retrospectively the effect of Bosentan and Sildenafil and their combination on Raynaud's phenomenon (RP), function, and capillaroscopic patterns. One hundred and twenty-three SSc patients (mean age ± sd, 57.69 ± 14.07 years) were retrospectively evaluated and divided into two groups according to American College of Rheumatology (ACR)/European League Against Rheumatism (EULAR) classification score: group 1 score < 10, group 2 score > 10. Each group was divided into three subgroups according to treatment: Bosentan, Sildenafil, and Bosentan + Sildenafil. Nailfold videocapillaroscopy (NVC), Scleroderma Health Assessment Questionnaire (SHAQ) and Raynaud Condition Score (RCS) were performed at baseline and after 3 and 6 months. In Bosentan (29 patients: 12, group 1; 17, group 2), NVC changed significantly in both groups, after 3 and 6 months (p = 0.00439, group 1; p = 0.00035, group 2). In group 1, the "active" and the "late" patterns reduced, and the "aspecific" increased. In group 2, there was a reduction of late patterns, a worsening of SHAQ (p < 0.005) and an improvement of RCS (p = 0.00014). In Sildenafil (63 patients: 35, group 1; 28, group 2), after 3 months, NVC patterns changed significantly in both groups(p = 0.042 group 1, p = 0.00089 group 2). In group 1, the late and early patterns increased, and the aspecific decreased. In group 2, a significant change of NVC pattern was observed also after 6 months (p = 0.00089): the late pattern increased while the active one reduced. After 6 months, SHAQ was significantly reduced in group 1 (p = 0.00027) and in group 2 (p = 0.0043). RCS improved in both groups (p = 0.0042, group 1; p = 0.0016, group 2). Combination therapy (Bosentan + Sildenafil) (31 patients: 14, group 1; 17, group 2) induced significant changes on NVC only in group 1 after 3 (p = 0.00256) and 6 months (p = 0.000349) with a reduction of the late and active patterns and an increase of the early pattern. In both groups, after 6 months, SHAQ (p < 0.05, group 1; p = 0.00049, group 2) and RCS significantly reduced (group 1, p = 0.00024; group 2, p = 0.0021). Patients treated with Bosentan + Sildenafil show a significant improvement of RCS and NVC. This combination therapy may exert a vascular activity achieving an amelioration of the structure of microvasculature in SSc.


Assuntos
Microvasos/efeitos dos fármacos , Doença de Raynaud/tratamento farmacológico , Escleroderma Sistêmico/tratamento farmacológico , Citrato de Sildenafila/administração & dosagem , Sulfonamidas/administração & dosagem , Vasodilatadores/administração & dosagem , Adulto , Idoso , Bosentana , Capilares/fisiopatologia , Quimioterapia Combinada , Feminino , Humanos , Masculino , Angioscopia Microscópica , Pessoa de Meia-Idade , Unhas/irrigação sanguínea , Estudos Retrospectivos , Resultado do Tratamento
15.
Autoimmun Rev ; 14(12): 1111-5, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26235995

RESUMO

Systemic sclerosis is a chronic multi-organ autoimmune disease, leading to important clinical and psychological implications. Among organ complications, sexual dysfunction is a major issue for both male and female gender, with high prevalence and great impact on quality of life, although frequently not addressed by both clinicians and patients. While erectile dysfunction is the most common cause of sexual problems in males, genital tract and general physical changes are major contributors to sexual impairment in females. This review presents current state of the art on this topic, discussing published data on presentation, evaluation and therapeutic options.


Assuntos
Escleroderma Sistêmico/complicações , Disfunções Sexuais Fisiológicas/etiologia , Animais , Doença Crônica , Humanos , Prevalência , Qualidade de Vida , Comportamento Sexual , Disfunções Sexuais Fisiológicas/terapia
16.
J Math Biol ; 71(2): 361-98, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25168624

RESUMO

This work concerns the optimization of the dose fractionation for cancer radiotherapy schedules of the kind one fraction/day, five fractions/week, assuming a fixed overall treatment time. Constraints are set to limit the radiation damages to surrounding normal tissues, as well as the daily fraction size. The response to radiation of tumour and normal tissues is represented by the classical LQ model, including the exponential repopulation term. We provide a framework to analytically determine the optimal weekly scheme of radiation doses as a function of the tumour type, the fraction upper bound and the normal tissue parameters. For a comparison with the literature, we present some numerical examples of optimal treatment schedules for specific tumour types.


Assuntos
Fracionamento da Dose de Radiação , Neoplasias/radioterapia , Biologia Computacional , Humanos , Modelos Lineares , Conceitos Matemáticos , Modelos Biológicos , Dinâmica não Linear , Planejamento da Radioterapia Assistida por Computador , Fatores de Tempo
18.
J Math Biol ; 66(1-2): 311-49, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22314975

RESUMO

We address the problem of finding the optimal radiotherapy fractionation scheme, representing the response to radiation of tumour and normal tissues by the LQ model including exponential repopulation and sublethal damage due to incomplete repair. We formulate the nonlinear programming problem of maximizing the overall tumour damage, while keeping the damages to the late and early responding normal tissues within a given admissible level. The optimum is searched over a single week of treatment and its possible structures are identified. In the two simpler but important cases of absence of the incomplete repair term or of prevalent late constraint, we prove the uniqueness of the optimal solution and we characterize it in terms of model parameters. The optimal solution is found to be not necessarily uniform over the week. The theoretical results are confirmed by numerical tests and comparisons with literature fractionation schemes are presented.


Assuntos
Modelos Biológicos , Neoplasias/radioterapia , Morte Celular/efeitos da radiação , Fracionamento da Dose de Radiação , Relação Dose-Resposta à Radiação , Humanos , Modelos Lineares , Conceitos Matemáticos , Neoplasias/patologia , Dinâmica não Linear , Tolerância a Radiação
19.
20.
Clin Rheumatol ; 31(12): 1723-5, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23053682

RESUMO

Bosentan, a dual endothelin receptor antagonist, may reduce blood pressure by blocking the vasoconstrictor effect of endothelin-1. In systemic sclerosis (SSc) nailfold videocapillaroscopy (NVC); allows diagnostic and follow-up of microvascular damage. Distinct NVC patterns have been identified for the evaluation of severity of SSc microvascular damage. The objective of this study is to evaluate the modification of the microvasculature under Bosentan therapy in SSc patients with pulmonary arterial hypertension (PAH). Nine patients with PAH related to SSc in New York Heart Association classes III-IV were treated with Bosentan 125 mg twice a day. NVC optical probe videocapillaroscopy equipped with 100× and 200× contact lenses and connected to image analyse software was performed before and after 12 months of Bosentan therapy to evaluate the modification of microvasculature. Nine PAH SSc patients treated with Iloprost were used as controls. Before Bosentan therapy, seven patients showed at NVC severe loss of capillaries with large avascular areas and vascular architectural disorganisation which are typically "late" SSc pattern. After 12 months of Bosentan, NVC pattern changed in seven patients from "late" into "active" SSc pattern. The disappearance of avascular areas and capillary haemorrhages was the most striking result. Two patients had an "active" SSc pattern, not modified by Bosentan treatment. These data show that Bosentan may improve NVC pattern in SSC and the presence of new capillaries suggests that it may favour angiogenesis. Bosentan may improve and stabilise the microvasculature in long-term treatment modulating the structural modifications detected by NVC.


Assuntos
Anti-Hipertensivos/uso terapêutico , Capilares/efeitos dos fármacos , Microvasos/efeitos dos fármacos , Unhas/irrigação sanguínea , Escleroderma Sistêmico/tratamento farmacológico , Sulfonamidas/uso terapêutico , Adulto , Idoso , Anti-Hipertensivos/farmacologia , Bosentana , Capilares/fisiopatologia , Feminino , Humanos , Masculino , Angioscopia Microscópica , Pessoa de Meia-Idade , Unhas/efeitos dos fármacos , Unhas/fisiopatologia , Escleroderma Sistêmico/fisiopatologia , Sulfonamidas/farmacologia , Resultado do Tratamento , Adulto Jovem
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