113 research outputs found
Multi-product firms and product variety
The goal of this paper is to study the role of multi-product firms in the market provision of product variety. The analysis is conducted using the spokes model of non-localized competition proposed by Chen and Riordan (2007). Firstly, we show that multi-product firms are at a competitive disadvantage vis-a-vis single-product firms and can only emerge if economies of scope are sufficiently strong. Secondly, under duopoly product variety may be higher or lower with respect to both the first best and the monopolistically competitive equilibrium. However, within a relevant range of parameter values duopolists drastically restrict their product range in order to relax price competition, and as a result product variety is far below the efficient level
Prediction of Nociceptive Responses during Sedation by Linear and Non-Linear Measures of EEG Signals in High Frequencies
The level of sedation in patients undergoing medical procedures evolves continuously, affected by the interaction between the effect of the anesthetic and analgesic agents and the pain stimuli. The monitors of depth of anesthesia, based on the analysis of the electroencephalogram (EEG), have been progressively introduced into the daily practice to provide additional information about the state of the patient. However, the quantification of analgesia still remains an open problem. The purpose of this work is to improve the prediction of nociceptive responses with linear and non-linear measures calculated from EEG signal filtered in frequency bands higher than the traditional bands. Power spectral density and auto-mutual information function was applied in order to predict the presence or absence of the nociceptive responses to different stimuli during sedation in endoscopy procedure. The proposed measures exhibit better performances than the bispectral index (BIS). Values of prediction probability of Pk above 0.75 and percentages of sensitivity and specificity above 70% were achieved combining EEG measures from the traditional frequency bands and higher frequency bands
Clinical characteristics and outcome of Spanish patients with ANCA-associated vasculitides: Impact of the vasculitis type, ANCA specificity, and treatment on mortality and morbidity
Spain; ANCA; VasculitidesEspanya; ANCA; VasculitisEspaña; ANCA; VasculitisThe aim of this study was to describe the clinical characteristics of ANCA-associated vasculitides (AAV) at presentation, in a wide cohort of Spanish patients, and to analyze the impact of the vasculitis type, ANCA specificity, prognostic factors, and treatments administered at diagnosis, in the outcome.A total of 450 patients diagnosed between January 1990 and January 2014 in 20 Hospitals from Spain were included. Altogether, 40.9% had granulomatosis with polyangiitis (GPA), 37.1% microscopic polyangiitis (MPA), and 22% eosinophilic granulomatosis with polyangiitis (EGPA). The mean age at diagnosis was 55.6â±â17.3 years, patients with MPA being significantly older (Pâ<â0.001). Fever, arthralgia, weight loss, respiratory, and ear-nose-throat (ENT) symptoms, were the most common at disease onset. ANCAs tested positive in 86.4% of cases: 36.2% C-ANCA-PR3 and 50.2% P-ANCA-MPO. P-ANCA-MPO was significantly associated with an increased risk for renal disease (OR 2.6, Pâ<â0.001) and alveolar hemorrhage (OR 2, Pâ=â0.010), while C-ANCA-PR3 was significantly associated with an increased risk for ENT (OR 3.4, Pâ<â0.001) and ocular involvement (OR 2.3, Pâ=â0.002). All patients received corticosteroids (CS) and 74.9% cyclophosphamide (CYC). The median follow-up was 82 months (IQR 100.4). Over this period 39.9% of patients suffered bacterial infections and 14.6% opportunistic infections, both being most prevalent in patients with high-cumulated doses of CYC and CS (Pâ<â0.001). Relapses were recorded in 36.4% of cases with a mean rate of 2.5â±â2.3, and were more frequent in patients with C-ANCA-PR3 (Pâ=â0.012). The initial disease severity was significantly associated with mortality but not with the occurrence of relapses. One hundred twenty-nine (28.7%) patients (74 MPA, 41 GPA, 14 EGPA) died. The mean survival was 58 months (IQR 105) and was significantly lower for patients with MPA (Pâ<â0.001). Factors independently related to death were renal involvement (Pâ=â0.010), cardiac failure (Pâ=â0.029) and age over 65 years old (Pâ<â0.001) at disease onset, and bacterial infections (Pâ<â0.001). An improved outcome with significant decrease in mortality and treatment-related morbidity was observed in patients diagnosed after 2000, and was related to the implementation of less toxic regimens adapted to the disease activity and stage, and a drastic reduction in the cumulated CYC and CS dose
Correlation between Topographic Vessel Density and Retinal Thickness Changes in Patients with Diabetic Macular Edema Treated with Anti-VEGF Therapy: Is It a Suitable OCTA Biomarker?
The objective of this study was to determine the correlation between topographic vessel density (VD) and retinal thickness (RT) reductions induced by vascular endothelial growth factor inhibitors (anti-VEGF) in patients with diabetic macular edema (DME) using optical coherence tomography angiography (OCTA). This was a prospective, interventional case series. VD and RT measurements were separately taken in four parafoveal subfields at baseline and after six months of treatment. This correlation was statistically assessed using Spearman's rho correlation coefficient after adjustment for multiple comparisons. The study included a total of 48 eyes in the final analysis. Mean VD decreased from baseline to month 6 (from 45.2 (+/- 3.5) to 44.6% (+/- 3.2) in the superficial capillary plexus and from 50 (+/- 3.3) to 49% (+/- 3.9) in the deep capillary plexus). Statistically significant reductions in RT were observed in all ETDRS sectors (p < 0.0001). No significant association was found between RT and VD, even when analyzing responders and non-responders separately. After six months of anti-VEGF treatment, no significant correlation was observed between the topographic VD and RT values. These findings suggest that reductions in VD values may not solely result from a reduction in microaneurysms, also being affected by the repositioning of displaced vessels due to edema and a reduction in their caliber. Therefore, VD changes may not be a suitable indirect OCTA biomarker of microaneurysm turnover and treatment response
To identify primary care interventions that reduce hospitalisation of people over 65 due to ambulatory care sensitive conditions
Objetivos:
Estudiar la percepciĂłn de los profesionales de atenciĂłn primaria (AP) sobre las enfermedades que con mayor frecuencia provocan hospitalizaciones en mayores de 65 años, analizar la concordancia con el listado ACSC (Ambulatory Care Sensitive Conditions) e identificar las intervenciones prioritarias que podrĂan reducir o evitar dicha hospitalizaciĂłn.
Diseño y método:
Estudio Delphi con expertos de AP procedentes de 7 centros de salud de Granada durante 2005. AnĂĄlisis descriptivo del consenso obtenido mediante cuestionarios autoadministrados.
Resultados:
Las enfermedades que causan en mayor medida ingresos en mayores de 65 años son: enfermedad pulmonar obstructiva crĂłnica (EPOC) agudizada, insuficiencia cardĂaca descompensada, accidente cerebrovascular y caĂdas-traumatismos. Las enfermedades analizadas forman parte del listado de ACSC salvo las caĂdas y los procesos cancerosos. El porcentaje estimado de hospitalizaciones evitables desde AP oscila entre el 20% para procesos cancerosos y el 70% para las descompensaciones diabĂ©ticas, y es superior al 50% para la EPOC, las hemorragias digestivas y la diabetes. Las intervenciones prioritarias para disminuir los ingresos hospitalarios abarcan la prevenciĂłn primaria, el diagnĂłstico precoz y el tratamiento correcto, con una gran variabilidad en la efectividad y la factibilidad percibida para cada intervenciĂłn concreta.
Conclusiones:
Las principales causas de ingresos hospitalarios en mayores de 65 años estån incluidas como ACSC. Las actuaciones prioritarias para reducir las hospitalizaciones evitables desde AP son intervenciones mixtas a las que, en su mayor parte, se les atribuye una efectividad y una factibilidad superiores al 50%.Objectives:
To study how primary care (PC) professionals perceive the pathologies that tend to cause hospitalisation of people over 65 most frequently, and to study their consistency with the list of ACSCs (Ambulatory Care Sensitive Conditions). To identify prior PC interventions that could reduce or prevent hospitalisation due to those pathologies.
Design and method:
A Delphi study with PC experts from 7 health care centres in Granada, Spain, during 2005. A descriptive analysis of the consensus obtained via self-administered questionnaires.
Results:
The diseases that cause the bulk of admissions in people over 65 are: acute COPD, non-compensated cardiac failure, cerebro-vascular accident, and falls-traumas. The pathologies analysed form part of the list of ACSCs, with the exception of falls, listed as the fourth cause, and cancer processes, listed as the sixth cause. The hospitalisation rates that could be avoided with prompt and effective PC varies between 20% for cancer processes to 70% for non-compensated diabetes. The rate is over 50% in COPD, digestive haemorrhages, and diabetes. The key interventions for reducing hospitalisations are primary prevention care, early diagnosis, and correct treatment. Effectiveness and feasibility vary widely for each particular intervention.
Conclusions:
The principal causes of hospitalisation in people over 65 are included as ACSC. Priority actions to reduce avoidable hospitalisations from PC are multi-modal interventions, the majority of which are over 50% effective and feasible
Common and Specific Associations of Anti-SSA/Ro60 and Anti-Ro52/TRIM21 Antibodies in Systemic Lupus Erythematosus
Little information exists about the association of anti-SSA/Ro60 and anti-Ro52/TRIM21 with systemic lupus erytematosus (SLE) features. In this work, we analysed the associations of both anti-Ro reactivities with clinical and immunological manifestations in 141 SLE patients. Photosensitivity and xerophtalmia/xerostomia were found to be positively associated with both anti-SSA/Ro60 (P=0.024 and P=0.019, resp.) and anti-Ro52/TRIM21 (P=0.026 and P=0.022, resp.). In contrast, a negative association was detected regarding anti-phospholipid antibodies, anti-SSA/Ro60 having a stronger effect (P=0.014) than anti-Ro52/TRIM21. Anti-SSA/Ro60 showed a specific positive association with hypocomplementemia (P=0.041), mainly with low C4 levels (P=0.008), whereas anti-Ro52/TRIM21 was found to be positively associated with Raynaudâs phenomenon (P=0.026) and cytopenia (P=0.048) and negatively associated with anti-dsDNA (P=0.013). Lymphocytes are involved in the relationship between anti-Ro52/TRIM21 and cytopenia since positive patients showed lower cell levels than negative patients (P=0.036). In conclusion, anti-SSA/Ro60 and anti-Ro52/TRIM21 showed both common and specific associations in SLE. These data thus increase evidence of the different associations of the two anti-Ro specificities even in a particular disease
IRF4 and IRGs Delineate Clinically Relevant Gene Expression Signatures in Systemic Lupus Erythematosus and Rheumatoid Arthritis
Introduction: Overactivation of the type I interferon (IFN) signature has been observed in several systemic autoimmune conditions, such as Systemic Lupus Erythematosus (SLE) or Rheumatoid Arthritis (RA). Impaired control of Interferon-Responding Genes (IRGs) expression by their regulatory mechanisms, including Interferon Regulatory Factors (IRFs), may underlie these findings and it may explain the heterogeneity observed among these conditions. In the present study we aimed to evaluate the associations between IRF4 gene expression and those of IRGs in SLE and RA patients to gain insight about its links with the IFN signature as well as to explore the potential clinical relevance of these associations.Methods: The gene expression of IRF4 and IRGs (IFI44, IFI44L, IFI6, and MX1) in peripheral blood was analyzed in 75 SLE patients, 98 RA patients, and 28 healthy controls. A group of 13 biological-naïve RA patients was prospectively followed upon TNFα-blockade. The associations among IRF4 and IRGs were evaluated by principal component analyses (PCA), correlations and network analyses. Publicly available datasets were used for replication.Results: A broad activation of IRGs was observed in autoimmune patients, although certain heterogeneity can be distinguished, whereas IRF4 was only upregulated in RA. The differential expression of IRF4 in RA was then confirmed in publicly available gene expression datasets. PCA revealed different associations among IRF4 and IRGs in each condition, which was later confirmed by correlation and network analyses. Cluster analysis identified 3 gene expression signatures on the basis of IRF4 and IRGs expression which were differentially used by SLE and RA patients. Cluster III was associated with markers of disease severity in SLE patients. Cluster II, hallmarked by IRF4 upregulation, was linked to clinical stage and mild disease course in RA. TNFα-blockade led to changes in the association between IRF4 and IRGs, whereas increasing IRF4 expression was associated with a good clinical outcome in RA.Conclusions: The differential expression of IRF4 and IRGs observed in SLE and RA can delineate gene expression signatures associated with clinical features and treatment outcomes. These results support a clinically-relevant phenomenon of shaping of the IFN signature by IRF4 in autoimmune patients
COVID-19 Associated Pulmonary Aspergillosis (CAPA): Hospital or Home Environment as a Source of Life-Threatening Aspergillus fumigatus Infection?
Most cases of invasive aspergillosis are caused by Aspergillus fumigatus, whose conidia are ubiquitous in the environment. Additionally, in indoor environments, such as houses or hospitals, conidia are frequently detected too. Hospital-acquired aspergillosis is usually associated with airborne fungal contamination of the hospital air, especially after building construction events. A. fumigatus strain typing can fulfill many needs both in clinical settings and otherwise. The high incidence of aspergillosis in COVID patients from our hospital, made us wonder if they were hospital-acquired aspergillosis. The purpose of this study was to evaluate whether the hospital environment was the source of aspergillosis infection in CAPA patients, admitted to the Hospital Universitario Central de Asturias, during the first and second wave of the COVID-19 pandemic, or whether it was community-acquired aspergillosis before admission. During 2020, sixty-nine A. fumigatus strains were collected for this study: 59 were clinical isolates from 28 COVID-19 patients, and 10 strains were environmentally isolated from seven hospital rooms and intensive care units. A diagnosis of pulmonary aspergillosis was based on the ECCM/ISHAM criteria. Strains were genotyped by PCR amplification and sequencing of a panel of four hypervariable tandem repeats within exons of surface protein coding genes (TRESPERG). A total of seven genotypes among the 10 environmental strains and 28 genotypes among the 59 clinical strains were identified. Genotyping revealed that only one environmental A. fumigatus from UCI 5 (box 54) isolated in October (30 October 2020) and one A. fumigatus isolated from a COVID-19 patient admitted in Pneumology (Room 532-B) in November (24 November 2020) had the same genotype, but there was a significant difference in time and location. There was also no relationship in time and location between similar A. fumigatus genotypes of patients. The global A. fumigatus, environmental and clinical isolates, showed a wide diversity of genotypes. To our knowledge, this is the first study monitoring and genotyping A. fumigatus isolates obtained from hospital air and COVID-19 patients, admitted with aspergillosis, during one year. Our work shows that patients do not acquire A. fumigatus in the hospital. This proves that COVID-associated aspergillosis in our hospital is not a nosocomial infection, but supports the hypothesis of "community aspergillosis" acquisition outside the hospital, having the home environment (pandemic period at home) as the main suspected focus of infection.S
Off-label use of rituximab for systemic lupus erythematosus in Europe
Objectives: Rituximab (RTX) is a biological treatment used off-label in patients with systemic lupus erythematosus (SLE). This survey aimed to investigate the off-label use of RTX in Europe and compare the characteristics of patients receiving RTX with those receiving conventional therapy. Methods: Data on patients with SLE receiving RTX were taken from the International Registry for Biologics in SLE retrospective registry and complemented with data on patients with SLE treated with conventional therapy. For nationwide estimates of RTX use in patients with SLE, investigators were asked to provide data through case report forms (CRFs). Countries for which no data were submitted through CRFs, published literature and/or personal communication were used, and for European countries where no data were available, estimates were made on the assumption of similarities with neighbouring countries. Results: The estimated off-label use of RTX in Europe was 0.5%-1.5% of all patients with SLE. In comparison with patients with SLE on conventional therapy, patients treated with RTX had longer disease duration, higher disease activity and were more often treated with immunosuppressives. The most frequent organ manifestations for which either RTX or conventional therapy was initiated were lupus nephritis followed by musculoskeletal and haematological. The reason for treatment was, besides disease control, corticosteroid-sparing for patients treated with conventional therapy. Conclusions: RTX use for SLE in Europe is restrictive and appears to be used as a last resort in patients for whom other reasonable options have been exhausted
- âŠ