COVID-19 infection and vaccination in patients with hereditary angioedema: a multicentric study.

Summary: Background. Due to similarities between the pathophysiological mechanisms of hereditary angioedema (HAE) and COVID-19, it has been hypothesized that SARS-CoV-2 infection may trigger HAE attacks or, alternatively, that HAE patients may experience different of COVID-19 disease severity. Furthermore, the potential for COVID-19 vaccination to trigger angioedema attacks in patients with HAE is still not completely defined. The objective is to characterize the exacerbations and clinical manifestations associated with COVID-19 infection and describe the adverse effects of COVID-19 vaccination in patients with HAE.Methods. Retrospective observational, descriptive, non-interventional, multicenter study conducted in four Allergy Units and Departments in Central Portugal between March 2020 and July 2022. HAE patient data were obtained from electronic medical records. Results. The study included 34 patients (67.6% female): 26 with HAE type 1, 5 with HAE type 2, and 3 with HAE with normal C1 inhibitor. Most patients with HAE type 1 and 2 were receiving long-term prophylaxis. Among the 32 patients who received COVID-19 vaccination, 86 doses, were administered with one angioedema attack (1.2%) associated with vaccination. A small increase in the average number of attacks was observed in the year following COVID vaccination (7.1 versus 6.2 in the previous year, p = 0.029), however, this difference is unlikely to be clinically significant, as the context of the COVID-19 pandemic likely introduced numerous confounders. During the study period, 16 HAE patients had COVID-19, all presenting with mild disease. Four out of 16 patients (25%) reported angioedema attacks during COVID-19, and 43.8% during the convalescence period (3 months after infection). Conclusions. Patients with HAE can safely receive COVID-19 vaccination. The severity of COVID-19 infection does not appear to be increased in HAE patients.

Molecular profiling in bee venom allergy: clinical and therapeutic characterization in a Portuguese cohort.

Summary: Background. Bee venom allergy (BVA) can trigger local and systemic allergic reactions, including anaphylaxis. Recently, the molecular sensitization profile has gained importance in the reaction's stratification and venom immunotherapy (VIT). Methods. Retrospective analysis of patients with hypersensitivity to BVA, confirmed by specific sIgE to Apis mellifera ≥0.35 kU/L and/or positive skin tests to bee venom commercial extract, evaluated in specialized consultation. Demographic, clinical, and laboratory data (including molecular Api m 1, 4, and 10) were analyzed, looking for risk factors associated with the severity of the index reaction and reactions during VIT. Results. 93 patients were included (55.9% male; median age of 46 years), 57.3% with atopic comorbidities, and 23.4% with cardiovascular comorbidities. The median specific IgE to Apis mellifera was 6.7 kU/L (IQR 1.0-20.3) kU/L. Regarding the molecular profile, the median IgE to Api m 1 was 0.5 kU/L (57.5% positive out of all measurements); Api m 4 - 0.01 kU/L (11.9% positive), and Api m 10 - 0.3 kU/L (50.0% positive). No patient was monosensitized to Api m 4. The median age of the most severe sting reaction was 36 (IQR 26-48) years, with a median severity (Müeller scale) of 3 (IQR 2-3). Forty-seven patients (50.5%) underwent VIT, with 35.6% of reactions recorded. Allergic reactions during VIT were recorded in 35.6% of cases. The severity of the index reaction correlated positively with older ages (p=0.040; r=0.249), in contrast to monosensitization to Api m 1, which was an independent predictor of milder reactions (p=0.015). Sensitization to Api m 10 was associated with a higher likelihood of reactions during VIT (p=0.038) but potentially less systemic reactions at re-stings (p=0.097). Conclusions. Molecular sensitization profile appears to be relevant not only to the severity of index reactions but also during VIT. Studies of a large cohort of patients with molecular profiles are essential to validate these results and improve the clinical and therapeutic approach to BVA.

Sensitization to genuine markers of timothy grass pollen (Phleum pratense) in the North-Central region of Portugal.

Summary: Pollens are the main cause of respiratory allergies which prevalence is increasing. The most important cause of pollinosis in Europe and especially in the Mediterranean countries as Portugal is Poaceae family pollen. Timothy grass (Phleum pratense) is one of the most common pollen sources, and one of the best characterized allergenic grasses. The major allergens Phl p1 and Phl p5 are considered markers of genuine grass pollen sensitization. A characterization of Phl p1 and Phl p5 sensitization in the North-Central region of Portugal was made in children and adults. Phl p1 sensitization was the most frequent.

Effects of melatonin on insulin signaling and inflammatory pathways of rats with apical periodontitis.

AIM: To verify the effects of melatonin supplementation on insulin sensitivity, plasma concentrations of inflammatory cytokines, insulin signalling and inflammatory pathways in the soleus (SM) and extensor digitorum longus (EDL) muscles of rats with apical periodontitis (AP). METHODOLOGY: Seventy-two Wistar rats were distributed into 4 groups: (a) control (C), (b) control supplemented with melatonin (M), (c) AP (AP), and (d) AP supplemented with melatonin (AP + M). AP was induced by pulp exposure of the maxillary and mandibular right first and second molars to the oral environment. After AP induction, oral supplementation with 5 mg kg-1 melatonin (diluted in drinking water) for 60 days was initiated. At the end of the treatment, the following were analysed: (1) plasma concentrations of insulin and inflammatory cytokines (TNF-α, IL-6, IL-1ß and IL-10) using ELISA kits; (2) glycaemia using enzymatic assay; (3) insulin resistance using homoeostasis model assessment of insulin resistance (HOMA-IR) index; and (4) phosphorylation status of pp185 tyrosine, Akt serine, IKKα/ß, and JNK in SM and EDL using Western blot. Analysis of variance of two or three factors was performed, followed by the Bonferroni test. P values < 0.05 were considered statistically significant. RESULTS: AP promoted insulin resistance, significantly increased (P < 0.05) plasma concentrations of pro-inflammatory cytokines (TNF-α, IL-6, and IL-1ß), significantly decreased (P < 0.05) the concentration of anti-inflammatory cytokine IL-10, impaired insulin signalling in SM, and increased IKKα/ß phosphorylation status in SM and EDL. Melatonin supplementation in rats with AP improved insulin sensitivity, significantly decreased (P < 0.05) TNF-α and IL-1ß, significantly increased (P < 0.05) IL-10 plasma concentrations, and changed the insulin signalling in soleus muscle and IKKα/ß phosphorylation status in SM and EDL muscles. CONCLUSIONS: Melatonin is a potent adjuvant treatment for improving apical periodontitis-associated changes in insulin sensitivity, insulin signalling and inflammatory pathways. In addition, the negative impact of AP on general health was also demonstrated.

Streptococcal tonsillitis as a cause of urticaria: tonsillitis and urticaria.

BACKGROUND: The primary role of infections in chronic urticaria (CU) is controversial. We hypothesised that streptococcal tonsillitis (ST) could be a primary cause of CU or acute recurrent urticaria (ARU). METHODS: Retrospective study of 14 outpatients observed between January 2000 and December 2009, with CU/ARU and clinical and/or laboratorial suspicion of an aetiopathogenic link with ST. Clinical history, objective examination and laboratorial study were looked for. Three groups were defined: spontaneous resolution of urticaria, resolution after tonsillectomy, and still symptomatic. RESULTS: In these patients, a causal relationship between ST and urticaria is supported by: markers of streptococcal infection, the perception of a clinical relationship between tonsillitis and urticaria, the decrease of urticaria severity with early antibiotherapy to tonsillitis and urticaria resolution after tonsillectomy. CONCLUSIONS: Our study encourages the investigation of tonsillitis in these otherwise idiopathic patients, especially until young adulthood and even in the absence of any symptoms.

Airways hyperresponsiveness to different inhaled combination therapies in adolescent asthmatics.

BACKGROUND: Inhaled combined therapy improves the pulmonary function in asthmatic patients. The effect on the airway hyperresponsiveness (AHR) and the efficacy of different pharmacological schedules is not well clarified on adolescent asthmatics. OBJECTIVE: Evaluate the responses to different combined inhaled therapies in adolescent asthmatics and study its impact on exercise induced AHR. METHODS: Basal lung function tests (LFT) were performed in 30 adolescents (13 to 16 years old; 19 female) with allergic asthma. They were submitted to exercise challenge test (EC) followed by bronchodilator test (BD). During 4 weeks, 15 adolescents were submitted to inhaled fluticasone/salmeterol (group A) and other 15 to inhaled budesonide/formoterol (group B). After this period, they underwent another functional evaluation as previous. RESULTS: Before treatment, pulmonary function was similar in both groups. After 4 weeks of treatment, these groups showed an improvement of the basal LFT (p = 0.001 for FEV1 in both), decrease on bronchoconstriction induced by exercise (NS for both) and less recovery on BD response (p = 0.001 and 0.002, for FEV1 respectively groups A and B). Group B showed a better performance, with higher improvement of basal FEF 25/75 (p = 0.001), reduced bronchoconstriction response to EC (p = 0.008 for FEV1) and fewer response to BD test (p < 0.0001 for FEV1 and 0.024 for FEF 25/75) No adverse events were observed. CONCLUSION: After 4 weeks of inhaled combined therapy, these patients improved their pulmonary function and bronchomotricity. Those under budesonide/formoterol showed the highest improvement. These medications are a safe measure in controlling the asthma in these patients.

T cell receptor excision circles (TREC) and recent thymic migrant cells in specific immunotherapy and respiratory allergy to Dermatophagoides pteronyssinus.

INTRODUCTION: T cell receptor excision circles (TREC) on CD31+ T cells are related to recent thymic emigrant cells (RTEs). The involvement of the functional thymic tissue occurs early in the IgE-mediated allergic reaction, and in response to specific immunotherapy (SIT). AIM: Evaluation of specific immunotherapy effects on TREC number in peripheral T cells in patients allergic to Dermatophagoides pteronyssinus (Dpt). METHOD: 85 respiratory allergic patients (both genders), 41 of them (Group II) under maintenance treatment to Dpt SIT (21 sublingual-SLIT, and 20 subcutaneous-SCIT), were selected. The allergic patients (Group I) without specific treatment were submitted to an allergen challenge test (22 nasal and 22 conjunctival). Peripheral cell analysis was performed immediately before treatment and 60 or 240 minutes after allergenic extract administration. TREC quantification was performed in CD4+CD31+ and CD8+CD31+. The results were expressed per 100.000 cells related to RTEs. Samples from 10 healthy individuals (Control - Group III) were obtained with the same method. RESULTS: The value of TRECs on RTEs was constant in control groups. For Group I patients (nasal or conjunctival test), TREC quantification in CD31+ T cells showed relevant individual changes, even in the patients tested earlier (60 minutes), and statistical significant at 240 minutes. Both SCIT and SLIT had also demonstrated enormous individual changes, particularly on TRECs/CD4+CD31+ cells assay. Basal values in Group III were significantly higher than those observed in active patients groups. CONCLUSION: Thymic functional activity is earlier involved in the allergic reaction and SIT IgE-mediated allergy is able to induce RTEs in the periphery, particularly TRECs/CD4+CD31+ cells. Both SLIT and SCIT showed reduced RETs in the periphery, probably due to maturation of regulatory T cells. Our results suggest a crucial role of the functional thymic tissue on the central mechanism of this therapy.

Topology studies of hydrodynamics using two-particle correlation analysis.

The effects of fluctuating initial conditions are studied in the context of relativistic heavy ion collisions where a rapidly evolving system is formed. Two-particle correlation analysis is applied to events generated with the NEXSPHERIO hydrodynamic code, starting with fluctuating nonsmooth initial conditions (IC). The results show that the nonsmoothness in the IC survives the hydroevolution and can be seen as topological features of the angular correlation function of the particles emerging from the evolving system. A long range correlation is observed in the longitudinal direction and in the azimuthal direction a double peak structure is observed in the opposite direction to the trigger particle. This analysis provides clear evidence that these are signatures of the combined effect of tubular structures present in the IC and the proceeding collective dynamics of the hot and dense medium.

Thoracic high resolution computed tomography (HRCT) in asthma.

INTRODUCTION: High-resolution computed tomography (HRCT) is a widespread medical imaging method for the study of thoracic diseases. In asthma it is very useful particularly when it is difficult to achieve an effective control of disease, and in severe deterioration. AIM: It was intended to evaluate the imaging changes by HRCT in asthmatic patients and to assess the expression according to the symptoms and duration of disease. MATERIAL AND METHODS: Thirty three patients from the Outpatient Department, with asthma classified in the different clinical severity stages according to GINA, were randomly included. They were submitted to HRCT (Somaton Plus-4, Siemens). The lesions were classified in reversible (mucoid impaction, acinar pattern centrilobular nodules and lobar collapse) and irreversible (bronchiectasis, bronchial wall-thickening, sequellar line shadows and emphysema). RESULTS: The 33 asthmatic patients (20 female) had an average age of 44.76 +/- 16.98 years and a mean disease evolution time of 23.39 +/-14.83 years. 30% had mild persistent asthma, 43% moderate persistent asthma and 27% severe persistent asthma. All the patients were under inhaled corticotherapy. Only 6 patients had normal HRCT 4 with mild persistent asthma (4 to 25 years of duration of disease) and 2 with moderate persistent (10 to 48 years of duration of disease). 81.81% of the patients had changes in HRCT, being the irreversible lesions the most frequent. The most important irreversible lesions were observed in severe asthma patients with longer duration of disease. All the patients with reversible lesions had also irreversible changes. Most of the bronchiectasis were centrally located and were found in severe asthma patients. Irreversible changes were identified in 3 patients with mild asthma and a maximum of 6 years of duration of disease. DISCUSSION: HRCT findings were related with asthma severity and long lasting disease but there are some asthmatics that also present early abnormalities, even in milder forms. All the groups of asthmatic patients presented all types of imaging changes, including the irreversible ones. In asthma these changes can be the result of individual patterns of response to frequent exacerbations, leading to a persistent chronic inflammatory process that will determine airway remodelling, even in early stages of disease and/or mild asthma.

Body mass index and airway hyper-responsiveness in individuals without respiratory disease.

BACKGROUND: Overweight and obesity are major health issues in Western societies. They are related with a higher risk of different co-morbidities but their relationship with airway hyperresponsiveness (AHR) is still under discussion. Nevertheless, they are related to higher severity in asthma and other respiratory diseases. The aim of the study was to analyze the AHR in individuals with normal lung function without respiratory disorders, according to body mass index (BMI) calculation. METHODS: We performed clinical observation and basal lung function tests (LFT) in 595 consecutive individuals in order to exclude respiratory disease. 377 individuals fulfilled the criteria of normal values according international guidelines. They were submitted to standardized treadmill exercise test followed by bronchodilator test. FVC, FEV1, FEF 25/75, RV and Raw were obtained at different conditions according to BMI groups (I: lean; II: normal; III: overweight; IV obese). RESULTS: 55.2% of the sample was overweight or obese, and a signficant relationship was found with female gender and older ages (p=0.0046 and p<0.0001 respectively). The positive response to exercise test or bronchodilator beta2 agonists was not significantly frequent compared with the other groups. In obese individuals the exercise markedly reduced basal Raw and increased FEF 25/75. Lean individuals showed higher basal values of RV that was reduced upon exercise. Response to 12 agonists showed no differences according to weight biotypes. CONCLUSION: BMI hampers lung function in normal individuals, and seems not to be related to AHR. Regular exercise should be encouraged in overweight and obese individuals, since it increases their bronchial permeability as shown in lower frequency of positive exercise tests. The same is advisable for lean individuals for different reasons. Their increased basal RV and Raw improve upon exercise. Despite overweight and obesity are being related to a low-grade of basal systemic inflammation, there was no association with a higher basal bronchial hyperresponsiveness in these individuals.

Low-dose intravenous gammaglobulin in the treatment of severe autoimmune urticaria.

BACKGROUND: An autoimmune pathogenic mechanism is implicated in about one-third of patients with chronic urticaria (CU), involving circulating functional autoantibodies to either the high affinity IgE receptor (LgG1/IgG3 anti-FcARI) or to IgE, with histamine releasing activity. New therapeutic approaches had been developed for patients with severe or unresponsive to treatment symptoms, including the use of intravenous immunoglobulins (IVIG) as immunomodulators. AIM: To assess the efficacy of IVIG treatment in patients with evidence of autoimmune CU. METHODS: A group of 29 patients (F = 20, M = 9) with the diagnosis of autoimmune CU were selected from the outpatient department. All the patients showed daily symptoms of urticaria and/or angioedema, with unsatisfactory response to conventional therapy and a positive intradermal autologous serum test (AST). They were submitted to low dose of IVIG treatment each 4 weeks (0.15 g/kg), for a minimum of 6 months and a maximum of 51 months. They were evaluated for clinical scores, need of oral medication and AST results, before and after treatment. RESULTS: A clinical improvement was observed in 26 patients, with reduction of urticaria or angioedema complaints (p < 0.0001) and decreasing need for oral antihistamine medication (p = 0.002). 3 patients drop-out the treatment: one depending of severe adverse event and the other 2 with no response after the 5th treatment. 19:26 patients achieved complete remission of symptoms. A reduction of histamine-releasing activity was found in the majority of the patients, documented by the decrea, se of reactivity in AST at the end of the treatment (p = 0.002). 20 patients remained without symptoms during 12 months after. the active treatment, and the other 6 only reported non-severe complaints. CONCLUSION: IVIG is an effective therapeutic option in patients suffering from severe CU refractory to conventional treatment, in which autoimmune mechanism is involved. The efficacy persists for at least 12 months after treatment. However, the number of infusions needed to achieve clinical control, showed great range between patients.

Dynamics of cilia length in left-right development.

Reduction in the length of motile cilia in the zebrafish left-right organizer (LRO), also known as Kupffer's vesicle, has a large impact on left-right development. Here we demonstrate through genetic overexpression in zebrafish embryos and mathematical modelling that the impact of increased motile cilia length in embryonic LRO fluid flow is milder than that of short cilia. Through Arl13b overexpression, which increases cilia length without impacting cilia beat frequency, we show that the increase in cilium length is associated with a decrease in beat amplitude, resulting in similar flow strengths for Arl13b overexpression and wild-type (WT) embryos, which were not predicted by current theory. Longer cilia exhibit pronounced helical beat patterns and, consequently, lower beat amplitudes relative to WT, a result of an elastohydrodynamic shape transition. For long helical cilia, fluid dynamics modelling predicts a mild (approx. 12%) reduction in the torque exerted on the fluid relative to the WT, resulting in a proportional reduction in flow generation. This mild reduction is corroborated by experiments, providing a mechanism for the mild impact on organ situs.

Vozes negras / Black voices / Voces negras / Voix noires

O artigo objetiva suscitar reflexões críticas sobre o racismo estrutural e institucional no contexto das instituições psicanalíticas, uma vez que verificamos a ausência quase absoluta da população negra nestes ambientes, apesar do número expressivo de afrodescendentes no território brasileiro. Pretende igualmente interrogar como essas instituições têm se mobilizado a respeito desse tema e do debate, cada vez mais necessários, considerando a urgência dessa discussão e de ações que garantam o acesso deste grupo social população negra à formação psicanalítica. O texto visa sobretudo estimular os psicanalistas a repararem a desigualdade que vem se perpetuando, ao longo do processo histórico dessas instituições, ocasionado pelo apagamento e silenciamento sobre o tema.

The article aims to raise critical reflections on structural and institutional racism in the context of psychoanalytic institutions, since we verified the almost absolute absence of the black population in these environments, despite the expressive number of Afro-descendants in the Brazilian territory. It also intends to question how these institutions have mobilized about this theme and the debate, which are increasingly necessary, considering the urgency of this discussion and actions that guarantee the access of this social group of black population to psychoanalytic training. The text aims above all to encourage psychoanalysts to repair the inequality that has been perpetuated throughout the historical process of these institutions, caused by the erasure and silence on the subject.

El artículo tiene como objetivo plantear reflexiones críticas sobre el racismo estructural e institucional en el contexto de las instituciones psicoanalíticas, ya que constatamos la ausencia casi absoluta de la población negra en estos entornos, a pesar del expresivo número de afrodescendientes en el territorio brasileño. También se pretende cuestionar cómo estas instituciones se han movilizado sobre este tema y el debate, que son cada vez más necesarios, considerando la urgencia de esta discusión y acciones que garanticen el acceso de este grupo social de población negra a la formación psicoanalítica. El texto pretende sobre todo animar a los psicoanalistas a reparar la desigualdad que se ha perpetuado a lo largo del proceso histórico de estas instituciones, provocada por el borrado y silencio sobre el tema.

L'article vise à soulever des réflexions critiques sur le racisme structurel et institutionnel dans le contexte des institutions psychanalytiques, puisque nous avons vérifié l'absence presque absolue de la population noire dans ces environnements, malgré le nombre expressif d'afro-descendants sur le territoire brésilien. Il entend également interroger comment ces institutions se sont mobilisées autour de cette thématique et du débat, de plus en plus nécessaires, compte tenu de l'urgence de cette réflexion et des actions qui garantissent l'accès de ce groupe social de population noire à la formation psychanalytique. Le texte vise avant tout à inciter les psychanalystes à réparer l'inégalité qui s'est perpétuée tout au long du processus historique de ces institutions, causée par l'effacement et le silence sur le sujet.

Development of new IgE specificities to hymenoptera allergens during venom-specific immunotherapy.

BACKGROUND: Despite the benefits of specific immunotherapy (SIT) being clinically well documented for allergic diseases, new IgE specificities to SIT extract allergens could be induced during the treatment. The authors evaluated these changes in patients allergic to Hymenoptera. METHODS: Six patients allergic to Hymenoptera venom were included in the study. Specific IgE (sIgE) levels determination and IgE immunoblots to Apis mellifera, Vespula spp. and Polistes spp. venom were performed before and after one year of SIT. RESULTS: All patients had sIgE levels reduction, after the first year of treatment, except one in whom there was an increase in sIgE levels to Apis mellifera venom, and two patients that maintained a similar value for Vespula spp. venom sIgE before and after one year of treatment. The immunoblot analysis revealed that most of the bands detected before beginning SIT, decreased in intensity or disappeared after one year of treatment. 3/6 patients developed new IgE specificities to venom extracts: one patient to the venom allergens in the treatment, other patient to allergens in other venom and another patient to both. After one year of treatment one of these patients tolerated a field sting by the corresponding insect. The newly recognised proteins were all minor allergens. CONCLUSION: These results confirm that sIgE levels tend to reduce during SIT, and the bands identifying some allergens in the blot tend to decrease or disappear. Nonetheless venom SIT can be responsible for the induction of new sensitisations to other venom allergens, apparently without clinical relevance.

Alternative functional criteria to assess airflow-limitation reversibility in asthma.

INTRODUCTION: International guidelines define significant bronchodilator response as absolute and percentage change from baseline in forced expiratory volume (FEV1) in the first second and/or forced vital capacity (FVC) ≥12% and 200 mL. However, bronchodilator effects on other lung function parameters have also been correlated to some degree of reversible airflow limitation. OBJECTIVES: To determine whether changes in other lung function parameters apart from FEV1 and FVC detect functional responses to bronchodilator in asthmatic patients. MATERIALS AND METHODS: Spirometry and body plethysmography were performed at baseline conditions and after administration of 400 µg of salbutamol by metered-dose inhaler through a space chamber device in asthmatic patients. Paired t-tests were used to compare lung function parameters between those with and without criteria for reversibility of airway obstruction according to ATS/ERS criteria. Cut-off values were obtained from the corresponding ROC curves. Measurements evaluated were FEV1, FVC, maximum mid-forced expiratory flow (FEF25-75%), residual volume (RV), inspiratory capacity (IC), airway resistance (Raw) and specific airway conductance (sGaw). RESULTS: From a total of 100 consecutive asthmatics patients (46% of them men; average age 58.7±14.1 years; 76% with mild to moderate obstruction), 50 patients had a significant bronchodilator response. All of these had noteworthy variations (p<0.004) in PEF, FEF25-75%, RV, Raw and sGaw. The most accurate in predicting a significant bronchodilator response were the absolute and percentage improvements in PEF (≥0.4 L/s and 8%), FEF25-75% (≥0.087 L/s and 27%) and the percentage of sGaw compared with that at baseline (≥25%). Based on these cut-off values, a sizeable number of the patients defined as non-responders had important changes in airway caliber. 17 patients had significant increments in the percentage of PEF and 10 had changes in absolute volume; 6 patients had increments in percentage and 16 in absolute change of FEF25-75%; 22 patients had increments in the percentage change of sGaw. CONCLUSIONS: Changes of FEV1 and/or FVC may underestimate significant functional response to bronchodilators in asthmatic patients with airway obstruction when considering the change in other lung function parameters.

Magnetic field driven interminiband charge transfer in InGaAs/InP superlattices.

The characteristic energies, occupancies and polarizations of the minibands formed by the Γ-Γ and Γ-Xz interlayer electon tunnelings in the InGaAs/InP superlattices are studied in the regime of the integer quantum Hall effect by polarization resolved photoluminescence. Accordingly, the magnetic field induced shrinkage of the interminiband gap, predicted by the theory, and as a consequence, the redistribution of charge over the superlattice minibands and the depolarization of the quantum Hall electron states are observed at odd filling factors. The response of the electrons residing in the InGaAs/InP superlattice minibands to the magnetic field is found very similar to the corresponding response of the electrons confined in the symmetric and anti-symmetric two-dimensional minibands of GaAs/AlGaAs double quantum wells. The presented results are evidence of the formation of the correlated states in multi-component electron systems formed in semiconductor multiple layers at odd filling factors.

Macrophages stimulated with lipopolysaccharide release a selective neutrophil recruitment inhibitory factor: an in vivo demonstration.

Intravenous injections of lipopolysaccharide (LPS, 20 micrograms/kg) and of a factor originating from LPS-stimulated macrophage monolayers (Neutrophil Recruitment Inhibitory Factor, NRIF) inhibited neutrophil migration into peritoneal cavities induced by carrageenin in rats for up to 24 h. Mononuclear cell migration induced by thioglycollate was also inhibited by the same treatment with LPS but was not affected by NRIF. We conclude that NRIF specifically blocks neutrophil migration and we suggest that NRIF released into the circulation may constitute an important determinant of septicemia.