Proteinúria na fibrose cística: possível correlação entre genótipo e fenótipo renal

OBJECTIVE: To assess proteinuria in patients with cystic fibrosis (CF), and to correlate proteinuria with genotype, CF-related diabetes and disease severity. METHODS: A prospective study was carried out over a six-month period and involving 22 CF patients. After the collection and analysis of 24-h urine samples, the patients were divided into two subgroups: protein excretion 150 mg/day (highproteinuria). Patient charts were reviewed to obtain data on genotype and CF-related diabetes. Disease severity was assessed based on acute exacerbations in the last six months and FEV1 measured during the study period. To assess the correlation between genotype and proteinuria, the two main mutations (DeltaF508 and R334W) were evaluated. Due to the existence of genotype DeltaF508/R334W, two categories were created to enable statistical analysis, DeltaF508 being evaluated in category 1 and R334W being evaluated in category 2. RESULTS: The DeltaF508 mutation tended to be associated with normal protein excretion: 100% of the low-proteinuria subgroup patients were considered DeltaF508 in category 1, compared with 86.7% in category 2. Protein excretion tended to be higher in patients with the R334W mutation: 60.0% of the high-proteinuria subgroup patients were considered R334W in category 1, compared with 80.0% in category 2 (p = 0.009 and p = 0.014, respectively). No significant association was found for any of the other variables. CONCLUSIONS: The results suggest that genotype is associated with renal phenotype, depending on the mechanism by which the genotype alters the function of the cystic fibrosis transmembrane conductance regulator gene

Evaluation of bone mineral density in cystic fibrosis patients

Patients with cystic fibrosis (CF) have an increasing life span and osteoporosis has become a more recognised problem in these patients. The pathogenesis of low bone mineral density (BMD) in CF seems to be multifactorial and the aim of this study was to assess the prevalence of low BMD in a group of CF outpatients and to relate the findings with the variables studied. The study included 22 patients aged between 14 and 45 years (mean age 26.3). Two of the subjects were lung transplant patients. BMD was assessed by dual-energy X-ray absorptiometry (DEXA) at the lumbar spine (LS) and femoral neck (FN). This data was correlated with serum 25-hydroxy vitamin D (25-OHD) levels, BMI and the forced expiratory volume in one second (FEV1). BMD (Z-score and T-score) ranged from 0.6 to -6 and from 0.5 to -6.7 at LS; at FN the scores ranged from 0.6 to -3.9 and from 0.6 to -4.1. The mean serum 25-OHD concentration (12,57 ng/ml) was at the low end of the normal range (10-60 ng/ml). On average patients did not present with malnutrition, however BMI ranged from 15.2 to 33.7 kg/m2. Lung function status was assessed by FEV1; 64% of patients had FEV1 below 80% and within this group four patients had a FEV1 under 40%. There was a positive correlation between low BMD and 25-OHD concentrations and also between BMD and FEV1. There was no linear correlation between BMD and BMI

Nonlinear dynamics of solitary and optically injected two-element laser arrays with four different waveguide structures: A numerical study

We study the nonlinear dynamics of solitary and optically injected two-element laser arrays with a range of waveguide structures. The analysis is performed with a detailed direct numerical simulation, where high-resolution dynamic maps are generated to identify regions of dynamic instability in the parameter space of interest. Our combined one- and two-parameter bifurcation analysis uncovers globally diverse dynamical regimes (steady-state, oscillation, and chaos) in the solitary laser arrays, which are greatly influenced by static design waveguiding structures, the amplitude-phase coupling factor of the electric field, i.e. the linewidth-enhancement factor, as well as the control parameter, e.g. the pump rate. When external optical injection is introduced to one element of the arrays, we show that the whole system can be either injection-locked simultaneously or display rich, different dynamics outside the locking region. The effect of optical injection is to significantly modify the nature and the regions of nonlinear dynamics from those found in the solitary case. We also show similarities and differences (asymmetry) between the oscillation amplitude of the two elements of the array in specific well-defined regions, which hold for all the waveguiding structures considered. Our findings pave the way to a better understanding of dynamic instability in large arrays of lasers

Effects of detuning, gain-guiding, and index antiguiding on the dynamics of two laterally coupled semiconductor lasers

Four examples of laterally coupled semiconductor lasers with different waveguiding structures have been studied using coupled mode theory and allowing for frequency detuning between the lasers. The structures include purely real index guiding, pure gain-guiding, and combinations of index guiding and antiguiding with gain-guiding. The dynamics of these four systems have been explored using AUTO software (standard numerical continuation package), linear stability analysis, and direct integration of the rate equations. Convincing agreement between results obtained by these three methods has been demonstrated, including effects due to variation of laser pumping rate, detuning, and linewidth enhancement factor. A periodicity of behavior with laser separation has been revealed that was previously overlooked. This periodicity has increasing influence on the bifurcations of the system as the structures develop from those with purely real guidance to a combination of index antiguiding and gain-guiding. The laser design and operating parameters used are realistic for a wide range of edge-emitting and surface-emitting lasers of practical importance, so that the dynamics studied here are relevant to real systems of coupled lasers

Mapping bifurcation structure and parameter dependence in quantum dot spin-VCSELs

We consider a modified version of the spin-flip model (SFM) that describes optically pumped quantum dot (QD) spin-polarized vertical-cavity surface-emitting lasers (VCSELs). Maps showing different dynamical regions and those consisting of various key bifurcations are constructed by direct numerical simulations and a numerical path continuation technique, respectively. A comparison between them clarifies the physical mechanism that governs the underlying dynamics as well as routes to chaos in QD spin-VCSELs. Detailed numerical simulations illustrate the role played by the capture rate from wetting layer (WL) to QD ground state, the gain parameter, and the amplitude-phase coupling. By tuning the aforementioned key parameters in turn we show how the dynamical regions evolve as a function of the intensity and polarization of the optical pump, as well as in the plane of the spin relaxation rate and linear birefringence rate, which is of importance in the design of spin lasers promising potential applications. By increasing the capture rate from WL to QD our simulation accurately describes the transition from the QD spin-VCSEL to the quantum well case, in agreement with a previous mathematical derivation, and thus validates the modified SFM equations

Bronchoalveolar lavage in occupational lung diseases

Occupational lung diseases (OLDs) are related to the exposure and inhalation of organic, inorganic, and synthetic particles, fumes, gases, or infectious agents. From the long list of OLDs this article focuses the discussion on bronchoalveolar lavage (BAL) in parenchymal immunoinflammatory conditions, such as hypersensitivity pneumonitis (HP) and pneumoconiosis. Several antigens may cause HP, including products of plant or animal origin, aerosolized microorganisms, and organic chemicals. BAL is used not only to assess the pathogenesis of these diseases but also to identify the typical pattern of intense lymphocytic alveolitis, usually with a CD4:CD8 ratio below normal and frequently with the presence of mast cells, plasma cells, and foamy macrophages. Pneumoconioses are chronic interstitial lung diseases caused by the inhalation of mineral and metallic inorganic particles/dusts in an occupational setting, showing a decreasing prevalence in recent years. BAL is a useful tool not only to express the complex pathogenic mechanisms of these entities but also in excluding other diagnoses and causes of alveolitis, and to document specific exposures, such as the identification of asbestos bodies (ABs) in asbestosis or the proliferative response of BAL lymphocytes to beryllium in chronic beryllium disease (CBD)

Algebraic expressions for the polarisation response of spin-VCSELs

Closed-form expressions are derived for the relationship between the polarisation of the output and that of the pump for spin-polarised vertical-cavity surface-emitting lasers. These expressions are based on the spin-flip model (SFM) combined with the condition that the carrier recombination time is much greater than both the spin relaxation time and the photon lifetime. Allowance is also included for misalignment between the principal axes of birefringence and dichroism. These expressions yield results that are in excellent agreement both with previously published numerical calculations and with further tests for a wide range of parameters. Trends with key parameters of the SFM are easily deduced from these expression

Sarcoidosis: a less common presentation.

The clinical presentation of sarcoidosis is diverse and in over 90% of patients there is pulmonary involvement. The most common features of the radiographic findings at the time of diagnosis are bilateral hilar lymphadenopathy and pulmonary infiltration. The authors report the case of a young female patient who presented with multiple bilateral nodular shadows on chest radiograph. Surgical biopsy revealed non-necrotizing granulomas with occasional multinucleated giant cells compatible with sarcoidosis. Although this was a case of stage III pulmonary disease, the patient was asymptomatic, lung function tests were normal and there were no signs of extrathoracic involvement. Spontaneous remission occurred without treatment as shown on high resolution CT scan follow-up, one year later