Phenotypic deficiencies of monocyte-derived dendritic cells in systemic lupus erythematosus

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ECG Round: A man with dizziness

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Role of mannose-binding lectin in the innate defense against Candida albicans: Enhancement of complement activation, but lack of opsonic function, in phagocytosis by human dendritic cells

Mannose-binding lectin (MBL) is a serum collectin believed to be of importance in innate immunity. We have investigated the role of MBL in the first-line defense against Candida albicans, an opportunistic fungal pathogen. MBL bound C. albicans via its lectin domain, resulting in agglutination of the organisms upon their outgrowth of hyphae. In a human in vitro MBL system, deposition of C4 fragments on C. albicans was increased when exogenous MBL was added to serum samples from MBL-deficient individuals. Similar enhancement of deposition of iC3b also was observed. MBL and enhanced opsonic C3 fragments mediated by MBL did not facilitate opsonophagocytosis of the organisms by monocyte-derived dendritic cells (DCs). However, MBL was found to inhibit the growth of C. albicans independently of complement activation, although, with complement activation, further inhibition was observed. We concluded that MBL plays an important role in the first-line defense against C. albicans without the need for opsonophagocytosis by DCs, in which a direct interaction of MBL with C. albicans results in agglutination and accelerated complement activation via the lectin pathway, leading to inhibition of growth.published_or_final_versio

ECG Round: A lady with dyspnoea

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ECG Round: A lady with palpitation

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ECG Round: Cardiac arrest

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A comparative outcome analysis of bilateral versus unilateral endoscopic extraperitoneal inguinal hernioplastics

Background: Bilateral inguinal hernia is an accepted indication for endoscopic totally extraperitoneal inguinal hernioplasty (TEP), but few studies have proved that the outcomes of bilateral TEP are as good as those of unilateral TEP. The objective of the present study was to compare the clinical outcomes of patients who underwent unilateral TEP with those of patients who underwent bilateral TEP. Patients and Methods: From June 1999 to May 2002, 103 patients underwent simultaneous bilateral TEP. The clinical data and outcomes of these patients were compared with those of an age-matched cohort of patients who underwent unilateral TEP during the same period. Results: The demographic features and hernia types were similar for the two groups. The incidence of direct inguinal hernia was significantly higher in the patients with bilateral inguinal hernia. The mean operative time for unilateral TEP was 65 minutes, and for bilateral TEP it was 97 minutes. The mean pain score at rest was significantly lower in the bilateral group than in the unilateral group on postoperative days 2 and 3. Pain scores at rest and during coughing from the day of operation to day 6 were otherwise comparable for the two groups. Comparisons of postoperative morbidity, length of hospital stay, and time to resumption of normal outdoor activities showed no significant differences between the two groups. Conclusions: The postoperative recovery and morbidity of patients who underwent bilateral TEP were equivalent to those who underwent unilateral TEP. Simultaneous bilateral TEP is safe and advantageous in patients with from bilateral inguinal hernias.published_or_final_versio

Confounding, homogeneity and collapsibility for causal effects in epidemiologic studies

Detection of confounding and confounders is important for observational studies, and especially so for epidemiologic studies. Miettinen and Cook (1981) derived two criteria for detecting confounders. Using a model, Wickramaratne and Holford (1987) proved that the two criteria are necessary but not sufficient conditions for confounders. We take uniform nonconfounding to mean there is no confounding at a coarse-subpopulation-level obtained by pooling any number of subpopulations. We discuss the necessity and sufficiency of the two criteria for uniform nonconfounding. The concepts of homogeneity and collapsibility for causal effects are also defined, and the relation among confounding, homogeneity and collapsibility is discussed. We show that the common causal effect over all fine subpopulations is just the causal effect of the whole population.published_or_final_versio

The effect of needle tip displacement in co-axial electrohydrodynamic processing

Co-axial electrospraying and electrospinning are versatile electrohydrodynamic (EHD) techniques that can be used to encapsulate a variety of materials in the form of polymeric particles and fibres via a one step process. The successful production of uniform encapsulated products in co-axial EHD (CEHD) processing depends on multiple parameters including solution concentration, applied voltage and needle capillary diameter. Although many studies have been conducted to investigate the effects of these parameters, there has been very limited research on how the axial displacement between the two needle tips affects the final products formed. Hence the purpose of this study was to adjust the positioning of the inner needle such that its tip extends beyond, is level with or resides inside that of the outer needle and to thus determine the most effective arrangement for controlling product size, uniformity and/or yield. Core–shell particles were prepared using two polymers, poly(lactic-co-glycolic)acid (PLGA) as the shell and polymethylsilsesquioxane (PMSQ) as the core and core–shell fibres using PMSQ as the shell and a volatile liquid, perfluorohexane (PFH) as the core. The products formed were analyzed by optical microscopy, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). After analysis, it was concluded that the most effective arrangement for generating both particles and fibres with the optimal combination of size, uniformity and yield was to have the inner needle 2 mm inside the outer needle. This allows for formation of a stable cone–jet and successful encapsulation of the inner liquid within the outer liquid, before the outer stable cone–jet forms. The corresponding collected product diameter and percentage of products in which material was successfully encapsulated were found to be 0.6 ± 0.1 μm and 85 ± 3% respectively for particles and 9 ± 1 μm and 92 ± 2% for fibres

Confounding, homogeneity and collapsibility for causal effects in epidemiologic studies

Detection of confounding and confounders is important for observational studies, and especially so for epidemiologic studies. Miettinen and Cook (1981) derived two criteria for detecting confounders. Using a model, Wickramaratne and Holford (1987) proved that the two criteria are necessary but not sufficient conditions for confounders. We take uniform nonconfounding to mean there is no confounding at a coarse-subpopulation-level obtained by pooling any number of subpopulations. We discuss the necessity and sufficiency of the two criteria for uniform nonconfounding. The concepts of homogeneity and collapsibility for causal effects are also defined, and the relation among confounding, homogeneity and collapsibility is discussed. We show that the common causal effect over all fine subpopulations is just the causal effect of the whole population.published_or_final_versio