RESUMO
BACKGROUND & AIMS: The impact of patient sex on the presentation of inflammatory bowel disease (IBD) has been poorly evaluated. Our aims were to assess potential disparities in IBD phenotype and progression between sexes. METHODS: We performed an observational multicenter study that included patients with Crohn's disease (CD) or ulcerative colitis from the Spanish ENEIDA registry. Data extraction was conducted in July 2021. RESULTS: A total of 51,595 patients with IBD were included, 52% were males and 25,947 had CD. The median follow-up period after diagnosis was 9 years in males and 10 years in females. In CD, female sex was an independent risk factor for medium disease onset (age, 17-40 y) (relative risk ratio, 1.45; 95% CI, 1.31-1.62), later disease onset (age, >40 y) (relative risk ratio, 1.55; 95% CI, 1.38-1.73), exclusive colonic involvement (odds ratio, 1.24; 95% CI, 1.14-1.34), inflammatory behavior (odds ratio, 1.14; 95% CI, 1.07-1.21), and extraintestinal manifestations (odds ratio, 1.48; 95% CI, 1.38-1.59). However, female sex was a protective factor for upper gastrointestinal involvement (odds ratio, 0.84; 95% CI, 0.79-0.90), penetrating behavior (odds ratio, 0.76; 95% CI, 0.70-0.82), perianal disease (odds ratio, 0.77; 95% CI, 0.71-0.82), and complications (odds ratio, 0.73; 95% CI, 0.66-0.80). In ulcerative colitis, female sex was an independent risk factor for extraintestinal manifestations (odds ratio, 1.48; 95% CI, 1.26-1.61). However, female sex was an independent protective factor for disease onset from age 40 onward (relative risk ratio, 0.76; 95% CI, 0.66-0.87), left-sided colonic involvement (relative risk ratio, 0.72; 95% CI, 0.67-0.78), extensive colonic involvement (relative risk ratio, 0.59; 95% CI, 0.55-0.64), and abdominal surgery (odds ratio, 0.78; 95% CI, 0.69-0.88). CONCLUSIONS: There is sexual dimorphism in IBD. The patient's sex should be taken into account in the clinical management of the disease.
RESUMO
AIMS: Methotrexate (MTX) is used to induce and maintain remission in patients with steroid-dependent Crohn's disease (CD). Despite its proven efficacy, its use is limited due to associated adverse events. Polymorphisms involving folate pathway genes might influence MTX efficacy and toxicity. We aimed to assess the impact of certain polymorphisms on the therapeutic outcomes of MTX in CD. METHODS: Patients with CD who exclusively followed MTX monotherapy and fulfilled inclusion criteria were identified from the GETECCU ENEIDA registry. Variants of ATIC, DHFR, MTHFR, SLC19A1, ABCB1 and ABCC3 genes were analysed and their association with efficacy and toxicity was assessed. RESULTS: A total of 129 patients were included in the analysis. MTX was used at a median weekly dose of 25 mg (interquartile range, 15-25 mg) and a median time of 14 months (interquartile range, 4-52 months). Thirty-seven percent of the patients achieved disease remission with MTX monotherapy, while 34% were nonresponders (MTX failure). MTX-related toxicity occurred in 40 patients (30%), leading to MTX discontinuation in 19%. DHFR rs408626 (odds ratio [OR] 3.12, 95% confidence interval [CI] 1.22-7.69; P = .017) and MTHFR rs1801133 (OR 2.86, 95% CI 1.23-6.68; P = .015) variants, and smoking (OR 2.61, 95% CI 1.12-6.05; P = .026) were associated with a higher risk of MTX failure. Additionally, the MTHFR rs1801131 variant was associated with a higher risk of MTX-related adverse effects (OR 2.78, 95% CI 1.26-6.13, P = .011). CONCLUSION: Our study shows that variants of MTHFR and DHFR genes may be associated with MTX efficacy and adverse events in patients with CD.
Assuntos
Doença de Crohn , Metotrexato , Sistema de Registros , Humanos , Metotrexato/uso terapêutico , Metotrexato/efeitos adversos , Metotrexato/administração & dosagem , Feminino , Masculino , Doença de Crohn/tratamento farmacológico , Doença de Crohn/genética , Adulto , Espanha , Pessoa de Meia-Idade , Adulto Jovem , Resultado do Tratamento , Marcadores Genéticos , Indução de Remissão/métodos , Polimorfismo de Nucleotídeo Único , Imunossupressores/efeitos adversos , Imunossupressores/uso terapêutico , Metilenotetra-Hidrofolato Redutase (NADPH2)/genéticaRESUMO
BACKGROUND AND AIMS: Familial inflammatory bowel disease (IBD) history is a controversial prognostic factor in IBD. We aimed to evaluate the impact of a familial history of IBD on the use of medical and surgical treatments in the biological era. METHODS: Patients included in the prospectively maintained ENEIDA database and diagnosed with IBD after 2005 were included. Familial forms were defined as those cases with at least one first-degree relative diagnosed with IBD. Disease phenotype, the use of biological agents, or surgical treatments were the main outcomes. RESULTS: A total of 5263 patients [2627 Crohn's disease (CD); 2636 ulcerative colitis (UC)] were included, with a median follow-up of 31 months. Of these, 507 (10%) corresponded to familial forms. No clinical differences were observed between familial and sporadic IBD forms except a lower age at IBD diagnosis and a higher rate of males in familial forms of UC. In CD, the proportions of patients treated with thiopurines (54.4% vs 46.7%; P = .015) and survival time free of thiopurines (P = .009) were lower in familial forms. No differences were found regarding the use of biological agents. Concerning surgery, a higher rate of intestinal resections was observed in sporadic CD (14.8% vs 9.9%, P = .027). No differences were observed in UC. CONCLUSIONS: In the era of biological therapies, familial and sporadic forms of IBD show similar phenotypes and are managed medically in a similar way; whether these is due to lack of phenotypical differences or an effect of biological therapies is uncertain. What is already known on this topic: IBD's etiopathogenesis points to an interaction between environmental and genetic factors, being familial history a controversial prognostic factor. Biological agents use and need for surgery regarding familial or sporadic forms of IBDs present conflicting results. What this study adds: Familial and sporadic forms of IBD have similar phenotypes and are managed medically and surgically in a similar way. How this study might affect research, practice or policy: Familial aggregation should not be considered a factor associated with more aggressive disease.
RESUMO
OBJECTIVE: Granulocyte-monocyte apheresis (GMA) has shown to be safe and effective in treating ulcerative colitis (UC), also in combination with biologics. The objective of this study is to evaluate the efficacy and safety of combining GMA after primary non-response (PNR) or loss of response (LOR) to tofacitinib (TOFA) in patients with UC. PATIENTS AND METHODS: Retrospective study including all patients with refractory UC who received GMA plus TOFA. Efficacy was assessed 1 and 6 months after finishing GMA by partial Mayo score, C-reactive protein (CRP) and fecal calprotectin (FC). Descriptive statistics and non-parametric tests were used in the statistical analysis. RESULTS: Twelve patients were included (median 46 years [IQR, 37-58]; 67% female; 67% E3). Patients were mostly receiving TOFA 10mg bid (75%), and 33% also concomitant steroids at baseline. Median partial Mayo score at baseline was 7 (IQR, 5-7), and it decreased to a median of 2 (IQR, 0-3) and 0 (IQR, 0-3) after 1 and 6 months (p=0.027 and 0.020, respectively), while no differences were found in CRP and FC. Clinical remission was achieved by 6 patients both at 1 (50%) and 6 months (67%). CF values<250mg/kg were achieved by 2 and 4 patients at 1 and 6 months (data available in 5 and 7 patients, respectively). No patient required dose-escalation of TOFA, and one patient was able to de-escalate the drug. No patient required colectomy and all patients under steroids were able to stop them. CONCLUSION: The combination of GMA and TOFA can be effective in selected cases of UC after PNR or LOR to this drug.
Assuntos
Colite Ulcerativa , Granulócitos , Monócitos , Piperidinas , Pirimidinas , Humanos , Estudos Retrospectivos , Feminino , Pessoa de Meia-Idade , Pirimidinas/uso terapêutico , Piperidinas/uso terapêutico , Piperidinas/administração & dosagem , Masculino , Colite Ulcerativa/terapia , Colite Ulcerativa/tratamento farmacológico , Adulto , Terapia Combinada , Pirróis/uso terapêutico , Pirróis/administração & dosagem , Proteína C-Reativa/análise , Resultado do Tratamento , Leucaférese/métodos , Inibidores de Proteínas Quinases/uso terapêuticoRESUMO
OBJECTIVE: Granulocyte-monocyte apheresis (GMA) has shown to be safe and effective in ulcerative colitis (UC), also in combination with biologics, mainly with anti-TNF. The aim of this study was to evaluate the efficacy and safety of combining GMA after primary non-response (PNR) or loss of response (LOR) to ustekinumab (UST) in patients with UC. PATIENTS AND METHODS: A retrospective study was performed in 12 IBD Units, including all patients with refractory UC or unclassified IBD (IBD-U) who received combined GMA plus UST. The number and frequency of GMA sessions, filtered blood volume and time of each session were registered. Efficacy was assessed 1 and 6 months after finishing GMA by partial Mayo score, C-reactive protein (CRP) and fecal calprotectin (FC). Descriptive statistics and non-parametric tests were used in the statistical analysis. RESULTS: Seventeen patients were included (15 UC, 2 IBD-U; median age 47 years [IQR, 35-61]; 59% male; 53% E3). Most patients (89%) had prior exposure to anti-TNF agents and 53% to vedolizumab; 65% were also receiving steroids at baseline. Median partial Mayo score at baseline was 6 (IQR, 5-7) and it significantly decreased after 1 and 6 months (p=0.042 and 0.007, respectively). Baseline FC significantly decreased after 6 months (p=0.028) while no differences were found in CRP. During follow-up, 18% patients started a new biologic therapy and 12% required surgery; 64% of patients under steroids were able to discontinue them. Adverse events were reported in one patient. CONCLUSION: GMA can recapture the response to UST in selected cases of UC after PNR or LOR to this drug.
RESUMO
INTRODUCTION: The prevalence of penetrating complications in Crohn's disease (CD) increases progressively over time, but evidence on the medical treatment in this setting is limited. The aim of this study was to evaluate the effectiveness of biologic agents in CD complicated with internal fistulizing disease. METHODS: Adult patients with CD-related fistulae who received at least 1 biologic agent for this condition from the prospectively maintained ENEIDA registry were included. Exclusion criteria involved those receiving biologics for perianal disease, enterocutaneous, rectovaginal, anastomotic, or peristomal fistulae. The primary end point was fistula-related surgery. Predictive factors associated with surgery and fistula closure were evaluated by multivariate logistic regression and survival analyses. RESULTS: A total of 760 patients from 53 hospitals (673 receiving anti-tumor necrosis factors, 69 ustekinumab, and 18 vedolizumab) were included. After a median follow-up of 56 months (interquartile range, 26-102 months), 240 patients required surgery, with surgery rates of 32%, 41%, and 24% among those under anti-tumor necrosis factor, vedolizumab, or ustekinumab, respectively. Fistula closure was observed in 24% of patients. Older patients, ileocolonic disease, entero-urinary fistulae, or an intestinal stricture distal to the origin of the fistula were associated with a higher risk of surgery, whereas nonsmokers and combination therapy with an immunomodulator reduced this risk. DISCUSSION: Biologic therapy is beneficial in approximately three-quarters of patients with fistulizing CD, achieving fistula closure in 24%. However, around one-third still undergo surgery due to refractory disease. Some patient- and lesion-related factors can identify patients who will obtain more benefit from these drugs.
Assuntos
Doença de Crohn , Fístula , Fístula Retal , Adulto , Humanos , Doença de Crohn/complicações , Doença de Crohn/tratamento farmacológico , Doença de Crohn/cirurgia , Ustekinumab/uso terapêutico , Resultado do Tratamento , Terapia Biológica , Necrose , Estudos Retrospectivos , Fístula Retal/etiologia , Fístula Retal/terapiaRESUMO
BACKGROUND: Patients with ulcerative colitis (UC) are at increased risk of Clostridioides difficile infection (CDI), which is the principal causative agent of nosocomial diarrhoea in western countries. This has been related to complications such as need of colectomy and mortality among these patients. The aim of this study was to assess the incidence and impact of CDI in patients hospitalised with UC. METHODS: Case-control retrospective study including patients admitted due to a UC flare from January 2000 to September 2018. Porpensity score matching (PSM) was performed to minimise selection bias taking into account the small number of cases compared to controls. RESULTS: 339 patients were included; CDI in 35 (10.3%) patients. After PSM, 35 (33.33%) cases and 70 (66.67%) controls were analysed. Patients with CDI presented higher rates of readmission (52.9% vs. 21.4%, p = .001), increased mortality within the first 3 months post-discharge (5.9% vs. 0%, p = .042) and increased need of therapy intensification in the first year after admission (20.7% vs. 12.5%, p = .001). No risk factors for CDI were identified. Multivariable cox regression showed that treatment with 5-aminosalycilates at baseline (HR 0.42, 95% CI 0.18-0.92) and albumin <3.5 g/dL (HR 3.11, 95% CI 1.21-8.03) were associated with worse outcomes. CONCLUSIONS: CDI is a prevalent situation in hospitalised UC patients related to higher mortality within the first 3 months after the infection, need for therapy intensification within the first year and readmission. Our results underline the importance of CDI detection in patients with a flare of UC.
Assuntos
Clostridioides difficile , Infecções por Clostridium , Colite Ulcerativa , Humanos , Colite Ulcerativa/epidemiologia , Estudos Retrospectivos , Assistência ao Convalescente , Alta do Paciente , Infecções por Clostridium/epidemiologia , Infecções por Clostridium/complicaçõesRESUMO
Drug combination therapy is the most common pharmacological strategy for hypertension management. No pharmacogenetic biomarkers for guiding hypertension pharmacotherapy are available to date. The study population were 64 volunteers from seven bioequivalence trials investigating formulations with valsartan, olmesartan and/or hydrochlorothiazide. Every volunteer was genotyped for 10 genetic variants in different transporters' genes. Additionally, valsartan-treated volunteers were genotyped for 29 genetic variants in genes encoding for different metabolizing enzymes. Variability in pharmacokinetic parameters such as maximum concentration (Cmax) and time to reach it (tmax), the incidence of adverse drug reactions (ADRs) and blood pressure measurements were analyzed as a function of pharmacogenetic and demographic parameters. Individuals with the ABCB1 rs1045642 T/T genotype were associated with a higher valsartan tmax compared to those with T/G and G/G genotypes (p < 0.001, ß = 0.821, R2 = 0.459) and with a tendency toward a higher postural dizziness incidence (11.8% vs. 0%, p = 0.070). A higher hydrochlorothiazide dose/weight (DW)-corrected area under the curve (AUC∞/DW) was observed in SLC22A1 rs34059508 G/A volunteers compared to G/G volunteers (p = 0.050, ß = 1047.35, R2 = 0.051), and a tendency toward a higher postural dizziness incidence (50% vs. 1.6%, p = 0.063). Sex impacted valsartan and hydrochlorothiazide pharmacokinetics, showing a lower exposure in women, whereas no significant differences were found for olmesartan pharmacokinetics.
Assuntos
Hidroclorotiazida , Hipertensão , Humanos , Feminino , Valsartana/efeitos adversos , Hidroclorotiazida/efeitos adversos , Tontura/induzido quimicamente , Tontura/tratamento farmacológico , Tetrazóis/efeitos adversos , Hipertensão/tratamento farmacológico , Hipertensão/genética , Hipertensão/induzido quimicamente , Variação Genética , Anti-Hipertensivos/efeitos adversos , Anti-Hipertensivos/farmacocinéticaRESUMO
High myopia is the most severe and pathological form of myopia. It occurs when the spherical refractive error exceeds -6.00 spherical diopters (SDs) or the axial length (AL) of the eye is greater than 26 mm. This article focuses on early-onset high myopia, an increasingly common condition that affects children under 10 years of age and can lead to other serious ocular pathologies. Through the genetic analysis of 21 families with early-onset high myopia, this study seeks to contribute to a better understanding of the role of genetics in this disease and to propose candidate genes. Whole-exome sequencing studies with a panel of genes known to be involved in the pathology were performed in families with inconclusive results: 3% of the variants found were classified as pathogenic, 6% were likely pathogenic and the remaining 91% were variants of uncertain significance. Most of the families in this study were found to have alterations in several of the proposed genes. This suggests a polygenic inheritance of the pathology due to the cumulative effect of the alterations. Further studies are needed to validate and confirm the role of these alterations in the development of early-onset high myopia and its polygenic inheritance.
Assuntos
Miopia , Criança , Humanos , Sequenciamento do Exoma , Miopia/genéticaRESUMO
Early-onset high myopia (EoHM) is a disease that causes a spherical refraction error of ≥-6 diopters before 10 years of age, with potential multiple ocular complications. In this article, we report a clinical and genetic study of 43 families with EoHM recruited in our center. A complete ophthalmological evaluation was performed, and a sample of peripheral blood was obtained from proband and family members. DNA was analyzed using a customized next-generation sequencing panel that included 419 genes related to ophthalmological disorders with a suspected genetic cause, and genes related to EoHM pathogenesis. We detected pathogenic and likely pathogenic variants in 23.9% of the families and detected variants of unknown significance in 76.1%. Of these, 5.7% were found in genes related to non-syndromic EoHM, 48.6% in genes associated with inherited retinal dystrophies that can include a syndromic phenotype, and 45.7% in genes that are not directly related to EoHM or retinal dystrophy. We found no candidate genes in 23% of the patients, which suggests that further studies are needed. We propose a systematic genetic analysis for patients with EoHM because it helps with follow-up, prognosis and genetic counseling.
Assuntos
Miopia , Distrofias Retinianas , Análise Mutacional de DNA , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Mutação , Miopia/diagnóstico , Miopia/genética , Linhagem , Distrofias Retinianas/genéticaRESUMO
BACKGROUND: Patients with inflammatory bowel disease (IBD) may present extraintestinal manifestations (EIMs) that affect the joints, skin, eyes, and hepatobiliary area, among others. AIMS: Our aim was to analyse the prevalence and characteristics of EIMs in patients with IBD and to identify the possible risk factors associated with the development of EIMs in the largest series published to date. METHODS: Observational, cross-sectional study including patients from the Spanish ENEIDA registry promoted by GETECCU. We retrospectively identified all cases of EIMs in the ENEIDA registry until January 2018. RESULTS: The study included 31,077 patients, 5779 of whom had at least one EIM (global prevalence 19%; 95% CI 18.2-19.0). Among the different types of EIMs, rheumatic manifestations had a prevalence of 13% (95% CI 12.9-13.7; 63% of EIMs), with a prevalence of 5% (95% CI 4.7-5.2) for mucocutaneous manifestations, 2.1% (95% CI 1.9-2.2) for ocular manifestations, and 0.7% (95% CI 0.6-0.8) for hepatobiliary manifestations. The multivariable analysis showed that the type of IBD (Crohn's disease, p < 0.001), gender (female, p < 0.001), the need for an immunomodulator (p < 0.001) or biologic drugs (p < 0.001), a previous family history of IBD (p < 0.001), and an extensive location of IBD (p < 0.001) were risk factors for the presence of EIMs. CONCLUSIONS: One-fifth of patients with IBD may have associated EIMs, with rheumatic manifestations as the most frequent (> 60% of EIMs). Female patients with severe Crohn's disease represent the group with the highest risk of developing EIMs. These patients should therefore be specially monitored and referred to the corresponding specialist when suggestive symptoms appear.
Assuntos
Doenças Inflamatórias Intestinais/diagnóstico , Doenças Inflamatórias Intestinais/epidemiologia , Sistema de Registros , Adulto , Estudos Transversais , Doenças do Sistema Digestório/diagnóstico , Doenças do Sistema Digestório/epidemiologia , Feminino , Humanos , Artropatias/diagnóstico , Artropatias/epidemiologia , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Estudos Retrospectivos , Espanha/epidemiologia , Adulto JovemRESUMO
This paper presents some considerations on the design of a novel antenna consisting of the combination of a transverse stubs (TS) array excited by Ridge Gap Waveguides (RGWs), as well as a discussion of the experimental results obtained from a prototype that was manufactured and measured. A combination of Continuous Transverse Stubs (CTSs) is used as the starting point. Subsequently, the CTSs are modified to include some metallic blockers that split each CTS into a combination (array) of shorter TSs. This is performed in order to excite each individual TS column using a different RGW; thus, ensuring a close to uniform field distribution in the transverse plane of the TS arrays. Hence, the directivity of the antenna is increased. As a series-feed configuration is considered, the antenna keeps a resonant behaviour, having a narrow-band response. A Corporate Feeding Network (CFN) using the aforementioned RGW technology placed in the same layer as the rest of the antenna is included in the design. The radiating area of the antenna is, finally, 5.88λ0×7.12λ0 with a simulated peak gain of 26.2 dBi and a Side Lobe Level (SLL) below -13 dB. A prototype is manufactured and tested. The simulated and measured radiation patterns maintain similar shapes to those of the simulations, with very similar angular widths in both main planes, although the frequency corresponding to the highest directivity changes to 31.8 GHz. A matching bandwidth of 517 MHz and a gain of 24.5 is, finally, achieved at that frequency.
Assuntos
Tecnologia , Tecnologia sem Fio , Desenho de Equipamento , Corpo HumanoRESUMO
Estimates suggest that more than 70% of the world's rangelands are degraded. The Normalized Difference Vegetation Index (NDVI) is commonly used by ecologists and agriculturalists to monitor vegetation and contribute to more sustainable rangeland management. This paper aims to explore the scaling character of NDVI and NDVI anomaly (NDVIa) time series by applying three fractal analyses: generalized structure function (GSF), multifractal detrended fluctuation analysis (MF-DFA), and Hurst index (HI). The study was conducted in four study areas in Southeastern Spain. Results suggest a multifractal character influenced by different land uses and spatial diversity. MF-DFA indicated an antipersistent character in study areas, while GSF and HI results indicated a persistent character. Different behaviors of generalized Hurst and scaling exponents were found between herbaceous and tree dominated areas. MF-DFA and surrogate and shuffle series allow us to study multifractal sources, reflecting the importance of long-range correlations in these areas. Two types of long-range correlation appear to be in place due to short-term memory reflecting seasonality and longer-term memory based on a time scale of a year or longer. The comparison of these series also provides us with a differentiating profile to distinguish among our four study areas that can improve land use and risk management in arid rangelands.
RESUMO
BACKGROUND: There is no information regarding the outcome of Crohn's disease (CD) patients treated with endoscopic balloon dilation (EBD) in non-referral hospitals, nor on the efficacy of EBD in ulcerative colitis (UC). We report herein the results of the largest series published to date. AIM: To assess the efficacy and safety of EBD for inflammatory bowel disease (IBD) stenosis performed in 19 hospitals with different levels of complexity and to determine factors related to therapeutic success. METHODS: We identified IBD patients undergoing EBD in the ENEIDA database. Efficacy of EBD was compared between CD and UC and between secondary and tertiary hospitals. Predictive factors of therapeutic success were assessed with multivariate analysis. RESULTS: Four-hundred dilations (41.2% anastomotic) were performed in 187 IBD patients (13 UC/Indeterminate colitis). Technical and therapeutic success per dilation was achieved in 79.5% and 55.3%, respectively. Therapeutic success per patient was achieved in 78.1% of cases (median follow-up: 40 months) with 49.7% requiring more than one dilation. No differences related to either diagnosis or hospital complexity was found. Technical success [OR 4.12 (95%CI 2.4-7.1)] and not receiving anti-TNF at the time of dilation [OR 1.7 (95% CI 1.1-2.6)] were independently related to therapeutic success per dilation. A stricture length ≤ 2 cm [HR 2.43 (95% CI 1.11-5.31)] was a predictive factor of long-term success per patient. The rate of major complications was 1.3%. CONCLUSIONS: EBD can be performed with similar efficacy and safety in hospitals with differing levels of complexity and it might be a suitable treatment for UC with short stenosis. To achieve a technical success and the short length of the stenosis seem to be critical for long-term therapeutic success.
Assuntos
Colite Ulcerativa/cirurgia , Doença de Crohn/cirurgia , Endoscopia Gastrointestinal/efeitos adversos , Sistema de Registros , Colite Ulcerativa/complicações , Constrição Patológica/etiologia , Doença de Crohn/complicações , Dilatação , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Probabilidade , Centros de Atenção Terciária , Resultado do TratamentoRESUMO
Javier P. Gisbert was listed incorrectly as Javier Pérez-Gisbert.
RESUMO
A planar array of low profile horns fed by a transverse slotted waveguide array in the low millimeter-wave regime (28 GHz) is presented. The array of transverse slots cannot be directly used as antenna as it has grating lobes due to the fact that slot elements must be spaced a guided wavelength. However, these slots can be transformed into low profile horns that with their radiation patterns attenuate the grating lobes. To this aim, low profile horns with less than 0.6λ0 height were designed. The horns include a couple of chips that contribute to further reduce the grating lobes especially in the H-plane. The good performance of the designed array was demonstrated by both simulations and experiments performed on a manufactured prototype. A 5 × 5 array was designed that has a measured realized gain of 26.6 dBi with a bandwidth below 2%, still useful for some applications such as some radar systems. The total electrical size of the array is 6.63λ0× 6.63λ0. The radiation efficiency is very high and the aperture efficiency is above 80%. This all-metal solution is advantageous for millimeter-wave applications where losses sustained by dielectric materials become severe and it can be easily scaled to higher frequencies.
RESUMO
Recently, there has been an increased interest in exploring periodic structures with higher symmetry due to various possibilities of utilizing them in novel electromagnetic applications. The aim of this paper is to discuss design issues related to the implementation of holey glide-symmetric periodic structures in waveguide-based components. In particular, one can implement periodic structures with glide symmetry in one or two directions, which we differentiate as 1D and 2D glide symmetry, respectively. The key differences in the dispersion and bandgap properties of these two realizations are presented and design guidelines are indicated, with special care devoted to practical issues. Focusing on the design of gap waveguide-based components, we demonstrate using simulated and measured results that in practice it is often sufficient to use 1D glide symmetry, which is also simpler to mechanically realize, and if larger attenuation of lateral waves is needed, a diagonally directed 2D glide symmetric structure should be implemented. Finally, an analysis of realistic holes with conical endings is performed using a developed effective hole depth method, which combined with the presented analysis and results can serve as a valuable tool in the process of designing novel electrically-large waveguide-based components.
RESUMO
An array of low profile horns fed by transverse slots on a groove gap waveguide (GGWG) is presented. The GGWG is implemented with glide symmetrical holes and the design frequency is 28 GHz. The low profile horns are integrated in the same waveguide wall as the slots. The designed antenna is a linear array of these horns but the solution can be easily extended to a planar array. Experimental results support this work. The designed antenna is a good candidate for applications related to 5G technologies where medium to high gains as well as high efficiencies are required and reasonable manufacturing costs are demanded.
RESUMO
BACKGROUND: The impact of prior anti-TNF use on "real-life" outcomes of adalimumab therapy in ulcerative colitis (UC) is not well known. AIM: To compare the influence of prior anti-TNF use on the outcomes of adalimumab maintenance treatment in UC patients. We also assessed the effectiveness of adalimumab dose escalation. METHODS: This retrospective multicenter cohort study included consecutive UC who advanced to an adalimumab maintenance regimen. Patients in whom adalimumab was discontinued prior to week eight of treatment were excluded. The co-primary efficacy endpoints were the cumulative probabilities of adalimumab failure-free survival and colectomy-free survival. We also assessed the need for and the effectiveness of adalimumab dose escalation. RESULTS: Of 184 UC on maintenance treatment with adalimumab, 116 (63%) had previous anti-TNF use. After a median follow-up of 23 months (interquartile range 13-49), 112 patients (60%) maintained corticosteroid-free clinical response. Sixty-nine patients (37%) had adalimumab failure, and 22 (12%) needed colectomy. Anti-TNF-naïve patients had significantly lower adjusted rates of adalimumab failure (hazard ratio [HR] 0.65; p < 0.001), adalimumab dose escalation (HR 0.35; p = 0.002), and need for colectomy (HR 0.26; p < 0.004). Seventy-six patients (41%) needed dose escalation after secondary loss of response, and 47% of these regained response after escalation. Short-term response after escalation was identified as a significant predictor of colectomy avoidance (HR 0.53; p = 0.007). CONCLUSIONS: In this "real-life" cohort of UC patients on maintenance treatment with adalimumab, anti-TNF-naïve patients had significantly better long-term outcomes. Adalimumab dose escalation enabled recovery of response in nearly half of patients.
Assuntos
Adalimumab/uso terapêutico , Antirreumáticos/uso terapêutico , Colite Ulcerativa/tratamento farmacológico , Adulto , Estudos de Coortes , Colectomia/estatística & dados numéricos , Relação Dose-Resposta a Droga , Substituição de Medicamentos , Feminino , Humanos , Infliximab/uso terapêutico , Quimioterapia de Manutenção , Masculino , Pessoa de Meia-Idade , Modelos de Riscos Proporcionais , Estudos Retrospectivos , Falha de Tratamento , Resultado do Tratamento , Fator de Necrose Tumoral alfa/antagonistas & inibidoresRESUMO
BACKGROUND: The incidence of inflammatory bowel disease is increasing in Europe and in Spain. However, there is no recent data from Southern Spain. OBJECTIVES: To determine the evolution of the hospital incidence of inflammatory bowel disease in Southern Spain. MATERIAL AND METHODS: A retrospective study was performed in two hospitals in Southern Spain. Data was collected from inflammatory bowel disease patients, divided into two periods (1995-2000 and 2001-2014) and compared. The reference population from both areas was 1,011,555 inhabitants. RESULTS: A total of 430 patients were registered during the first period (1995-2000); 50% (215) had Crohn's disease that resulted in a cumulative incidence rate of 7.08 cases/100,000 inhabitants per year. The overall inflammatory bowel disease incidence was 3.54 cases/100,000 inhabitants per year. During the second period (2001-2014), 2,089 patients were collected; 51.7% had ulcerative colitis (1,081). The rate of cumulative incidence of inflammatory bowel disease was 14.7 cases/100,000 inhabitants per year (7.6 cases of ulcerative colitis/100,000 inhabitants/year and 7.1 cases of Crohn´s disease/100,000 inhabitants/year). CONCLUSIONS: The incidence of inflammatory bowel disease in Southern Spain has doubled in the last decade and is similar to that of the rest of the country and Europe.