Aetiologies of Hyperprolactinaemia: A retrospective analysis from a tertiary healthcare centre

ABSTRACT: Objectives: This study aimed to evaluate the aetiologies of hyperprolactinaemia in the United Arab Emirates (UAE). Methods: This retrospective study used laboratory databases to identify all patients who underwent evaluation for prolactin at Tawam Hospital, Al Ain, UAE, between 2009 and 2015. Of those 2,280 patients, all patients with low or normal prolactin (n = 1,315) were excluded. Subsequently, charts of the remaining patients (n= 965) with hyperprolactinaemia were reviewed and those with incomplete work-ups or insufficient documentation of the hyperprolactinaemia’s aetiology were excluded (n = 458). Results: A total of 507 patients were included in the study. The average age at prolactin evaluation was 36 ± 13.2 years and the majority (67.1%) of patients were female. The most common reasons for requesting prolactin were menstrual disorders (29.5%), infertility (18%),evaluation of sellar masses (14.3%), ruling out seizures (13.4 %) and monitoring while on psychiatric medications (8.7%). The most common causes of hyperprolactinaemia were prolactinoma (17%), transient hyperprolactinaemia(14.6%), drug-induced side effects (14.4%), polycystic ovarian syndrome (11.8%) and seizure disorder (7.7%). In females, common aetiologies were prolactinomas, transient and idiopathic hyperprolactinaemia, while sellar masses, seizures, chronic kidney disease and acute illnesses were common aetiologies of hyperprolactinaemia in males. The prolactin level varied between the different aetiologies and a level of >250 ng/mL was suggestive of macroprolactinoma. Conclusion: A significant proportion of patients with hyperprolactinaemia have transient hyperprolactinaemia. Before further investigations are carried out, prolactin level assessment should be repeated, especially in patients with mild hyperprolactinaemia.Keywords: Hyperprolactinemia; Prolactinoma; Etiology; Epidemiology; United Arab Emirates

Behçet’s disease: Spectrum of MDCT chest and pulmonary angiography findings in patients with chest complaints

AbstractObjectiveThe aim of the work was directed to evaluate the value of multi-detector computed tomography pulmonary angiography study in evaluation of known patients with Behcet’s disease.Materials and methodsThis study was done retrospectively and included eighteen known patients with Behcet’s disease and referred for MDCT pulmonary angiography.ResultsPulmonary artery aneurysm was the most common finding as it was found in 16 patients, followed by pulmonary embolism which was found in 14 patients, 12 patients with pulmonary hypertension, right ventricular strain in 6 patients, intracardiac thrombus in 4 patients, dilated bronchial arteries in 8 patients, venous occlusion in 4 patients, mosaic attenuation of the lung in 12 patients, pulmonary infarcts in 4 patients, and pleural effusion in 4 patients.ConclusionMDCT pulmonary angiography is an important diagnostic imaging tool for diagnosis of vascular complications in patients with Behcet’s disease

Monocyte chemotactic protein-4 (MCP-4/CCL-13) and CC chemokine receptor 3 (CCR3) in the sputum of asthmatic children

Background: Monocyte chemotactic protein-4 (MCP-4/CCL-13) is a potent chemoattractant to eosinophils, monocytes and lymphocytes. Objective: We aimed to investigate MCP-4 and its CC chemokine receptor 3 (CCR3) expression on cells of induced sputum during acute asthma exacerbation. Methods: Immunohistochemistry was used to assess MCP-4 and CCR3 expression on induced sputum cells of 30 children during asthma exacerbation and 20 healthy matched controls. Patients were divided into three groups according to exacerbation severity; mild, moderate and severe (n = 10 for each). Patients were followed until quiescence, when sputum was re-examined. Results: MCP-4 and CCR3 were expressed on eosinophils and monocytes. Lymphocytes expressed only MCP-4. The percentages of sputum total cells, eosinophils and lymphocytes expressing MCP-4 and/or CCR3 were significantly higher during asthma exacerbation than in controls and negatively correlated with peak expiratory flow rate, whereas that of monocytes was not. The percentages of sputum total cells, eosinophils, monocytes and lymphocytes expressing MCP-4; and total cells and eosinophils expressing CCR3 were significantly higher in patients with severe than those with mild and moderate exacerbations. When patients were followed till remission, the percentages of sputum cells expressing MCP-4 and CCR3 decreased. Sputum eosinophil percentage correlated positively with the percentage of eosinophils expressing MCP-4 and CCR3 (r = 0.69, p < 0.0001; r = 0.62, p < 0.001, respectively). The percentage of sputum eosinophils expressing MCP-4 correlated positively with that of cells expressing CCR3 (r = 0.95, p < 0.0001). Conclusion: The expression of MCP-4 and CCR3 on sputum cells increases during acute asthma exacerbation and this increase correlates with exacerbation severity, and it decreases during remission. Modification of their expression could be a potential target for asthma therapy.Keywords: asthma, CCL-13; CCR3; chemokines; eosinophils; MCP-4; sputumEgypt J Pediatr Allergy Immunol 2008; 6(1): 13-2

A neutral-point diode-clamped converter with inherent voltage-boosting for a four-phase SRM drive

This paper proposes a new asymmetric neutral-point diode-clamped (NPC) multilevel converter for a four-phase switched reluctance motor drive. The inbuilt NPC clamping capacitors are used for both voltage level clamping and also as dc rail voltage-boosting capacitors to increase the output power of the motor, particularly for high-speed electric vehicle applications. The new converter allows regenerative energy to be recovered back to the dc supply for rapid machine braking, thus increasing overall drive efficiency. Analysis of the different modes of converter operation, along with design equations for sizing the voltage-boosting capacitors, are detailed. The effect of capacitance on boost voltage and increased motor base speed is presented. Simulation and experimental results confirm the effectiveness of the proposed converter

Power density improvement due to rotor flux screens in an SRM with a higher number of rotor poles than stator poles

This paper studies the performance of screened switched reluctance motors (SRMs) with a number of rotor poles higher than the number of stator poles. Flux (conducting) screens are electrically conducting, non-magnetic materials like aluminum or copper. These screens fill the interpolar rotor air gaps decreasing the unaligned inductance, and thereby increasing the output torque. In addition, flux screens result in a cylindrical rotor structure which minimizes windage losses especially at high speeds. The paper investigates the effect of the flux screens thickness and material on the SRM performance including output torque, power and phase current. A modified flux tube approach for estimating the unaligned inductance of screened SRM is proposed. Finite element analysis results for different screen cases confirm the effectiveness of conducting screens in improving the torque, hence power capability, of switched reluctance motors