Propensity score matching without conditional independence assumption—with an application to the gender wage gap in the United Kingdom

Summary Propensity score matching is frequently used for estimating average treatment effects. Its applicability, however, is not confined to treatment evaluation. In this paper, it is shown that propensity score matching does not hinge on a selection on observables assumption and can be used to estimate not only adjusted means but also their distributions, even with non‐i.i.d. sampling. Propensity score matching is used to analyze the gender wage gap among graduates in the UK. It is found that subject of degree contributes substantially to explaining the gender wage gap, particularly at higher quantiles of the wage distribution.     

The consequences of delayed intervention when treating chemical eye burns

Background Immediate rescue intervention for chemical and thermal eye burns can save the victim’s sight. We studied the anterior chamber pH changes immediately after ex vivo eye burn to investigate the effects of immediate and delayed intervention. Methods Twenty three enucleated pigs eyes were burnt with 500 μl 2 mol NaOH for 20 s using a cylinder with a diameter of 10 mm. The corneas were rinsed in groups with 1015 ml ordinary tap water at a flow rate of 1.125 ml/s for 15 minutes immediately after burning (n = 6), and after a delay of 20, 40, and 60 s (n = 5, 3 and 4 respectively). One group of eyes was not rinsed (n = 5). The intraocular pH was defined at the start as ‘min pH’ and the end as ‘max pH’(ΔpH = max pH-min pH). Results The intraocular pH increased sharply in the untreated eyes from a min pH of 6.76 ± 0.55 to a max pH of 11.85 ± 0.24, yielding a ΔpH of 5.08. The difference between the timepoint at which the pH began to increase and the speed of change was significantly different between the unrinsed and rinsed eyes, and there was an inverse correlation between this and the time at which rinsing started (p < 0.001). The best results were achieved in eyes rinsed immediately after burning (p < 0.001). The pH in the eyes not rinsed immediately increased rapidly, and in all groups in which rinsing was delayed the max pH was markedly higher (p = 0.093). Conclusions Immediate emergency rinsing is essential in eye burn victims. Appropriate rinsing solutions and treatment facilities in the form of rinsing stations where chemical burns may occur must be available at the workplace. Tap water is also effective as a rinsing solution. Presentation The results were the subject of a short oral presentation at the 104th DOG Annual Meeting 2006 in Berlin.     

Pseudarthrosis in fibrous dysplasia treated with bone morphogenetic protein

We present a case of pseudarthrosis in a patient suffering from polyostotic fibrous dysplasia of the right part of the body that was successfully treated with bone morphogenetic protein. Pseudarthrosis occurred after proximal femoral shaft fracture due to a motorcycle accident initially treated by intramedullary nailing. After revision, the patient was treated by pseudarthrosis debridement and grafting of bone morphogenetic protein-7/osteogenic protein-1, resulting in callus formation that allowed indolent full weight-bearing after 6 weeks. The underlying disease as well as the described treatment is discussed.     

Tolerability of N-chlorotaurine plus ammonium chloride in the rabbit and human eye - a phase 1 clinical study

Background  N-chlorotaurine (NCT), an endogenous mild antiseptic, is well-tolerated by application to the human conjunctiva and has been shown to offer beneficial effects in infectious conjunctivitis. Animal tests revealed improved efficacy of a combination of NCT with ammonium chloride in adenoviral conjunctivitis. The aim of this study was to evaluate the tolerability of NCT plus ammonium chloride in the healthy rabbit and human eye. Methods  First, a tolerability study was performed in rabbits. In a blinded and randomized fashion, one eye was treated with the test medication, the other one with 0.9% saline. Twenty-one animals (three per concentration) were treated with one drop every 2 hours for 6 days. Second, in two volunteers one drop of a defined concentration was applied to one eye every 15 min for 1 hour, saline to the control eye. Four different concentrations were tested on different days. Third, a double-blind, randomized phase 1 study in 13 healthy volunteers was performed. One drop of 0.1% NCT plus 0.1% NH₄Cl versus saline was applied every 15 min within the first hour, followed by four drops every 2 hours. This regimen was done daily for 5 days. Results  In rabbits, no side effects were seen with 0.1% NCT plus 0.1% NH₄Cl, while higher concentrations sometimes caused short-time and minimal conjunctival injection and secretion after dosing. By 1% NCT plus 1% NH₄Cl, these effects were moderate, but disappeared again without any detectable residues. In the pilot study with two volunteers, treatment with 0.5% NCT plus 0.1% NH₄Cl caused medium-scale eye burning for 30 seconds, while 0.1% NCT plus 0.1% NH₄Cl was very well-tolerated, with no or minimal burning for a few seconds. In the subsequent phase 1 study, 0.1% NCT plus 0.1% NH₄Cl was well-tolerated by all subjects except for minimal eye burning for a few seconds after dropping. No objective signs of eye changes could be detected in the human beings. Conclusion  The results of this study clearly demonstrate the good tolerability of a promising NCT formulation with improved activity.     

Impact of cell culture media on the expansion efficiency and T-cell receptor Vbeta (TRBV) repertoire of in vitro expanded T cells using feeder cells.

BACKGROUND: The effects of different cell culture media on expansion efficiency and alterations in T-cell receptor V beta (TRBV) expression of in vitro expanded lymphocytes are not well established. MATERIAL/METHODS: Low numbers of CD3+ T cells from peripheral blood lymphocytes of healthy donors were subjected to polyclonal in vitro expansion in the presence of autologous CD3-depleted mononuclear cells as feeder cells (FCs) and their numbers and TRBV expressions were compared in media containing human (HS-RPMI) or fetal bovine serum (FBS-RPMI), Panserin413, or X-Vivo 15TM designed for lymphocyte culture. RESULTS: During three courses of restimulation within 28 days with CD3-antibody (OKT-3), IL-2, and initial CD3+, T-cell: FC ratios of 1:50 lowered to 1:5 and T cells expanded more than 1,000-fold in the media containing complete sera. Loss of cluster formation, associated with expansion failure, was only observed in cultures using synthetic media and resulted in only about 70-fold expansion. Whereas TRVB expression as determined by real-time PCR was substantially altered after 14 days of culture in X-Vivo 15, at day 28 only T cells from long-term culture in HS-RPMI presented the initial TRBV composition. CONCLUSIONS: Culture media have substantial impact on in vitro T-cell expansion. In the presence of FCs, medium containing human serum is superior to synthetic media and FBS-RPMI for long-term culture regarding T-cell number and TRBV repertoire. In contrast, the synthetic media Panserin413 and XVivo15 show lower expansion efficiency and reproducibility and, as RPMI1640+10%FBS, can contribute to overstimulation of certain TRBVs at advanced culture time points.     

The very small-conductance K+ channel KVLQT1 and epithelial function

KvLQT1 (KCNQ1) is a very small conductance K+ channel distributed widely in epithelial and non-epithelial tissues. Its specific biophysical and pharmacological properties are determined by the regulatory subunits IsK (KCNE1) and MiRP2 (KCNE3). In epithelial cells of the inner ear, pancreas, and airways it interacts with IsK to conduct a voltage-gated and slowly activating K+ current. In the colon it coassembles with KCNE3 to conduct an instantaneous and constitutively active K+ current. In Cl- secretory epithelia, such as the colon and pancreas, this K+ channel provides the driving force for Cl- exit and is located in the basolateral membrane. In the inner ear it enables luminal secretion of K+ into the endolymphatic space. The functional relevance of KvLQT1 to epithelial function is revealed by blocking it pharmacologically or by studying animals with a genetic defect for it, which result in the breakdown of colonic Cl- secretion and endolymph production, respectively. KvLQT1 K+ channels are activated via cAMP or Ca2+ and inhibited by the chromanol 293B. Interaction with as yet unknown regulatory subunits may determine the properties of KvLQT1 in the rectal gland and other epithelial tissues in which KvLQT1 is not inhibited by chromanols.     

On the grammar of ``psychosis'

This study in the philosophy of psychiatrydeals with the concept `psychosis'. Methodologicallyit follows Wittgenstein's proposal to `dissolve'philosophical problems by studying the actual use ofthe relevant concepts. Philosophical problemsconcerning both identification of psychosis and themeaning of this concept are pointed out. The logicaldependencies between `psychosis' and `understanding'and between `understanding' and the concept ofperson are demonstrated. Studying theinterdependence of these concepts in the light ofthe actual uses of `madness' shows how the use of`psychosis' implies a radical loss of understanding.The status and legitimacy of `psychosis' as a psychiatric concept is then demonstrated.     

Influence of contrast-enhanced computed tomography on course and outcome in patients with acute pancreatitis

INTRODUCTION: Many of the complications in severe acute pancreatitis result from the amplifying effects of microcirculatory disruption. Contrast medium may cause significant additional reductions of capillary flow, which has been shown to aggravate acute pancreatitis in experimental studies. AIM: To investigate the role of serial contrast-enhanced computed tomography (CECT) in patients with acute pancreatitis. METHODOLOGY: A retrospective analysis evaluated 302 patients with moderate to severe acute pancreatitis. Among these patients, 264 underwent CECT within 96 hours of the onset of symptoms and again during the course, but in 38 patients no serial CECT was performed. Outcome measurement was analyzed by comparison of hospital stay and mortality rate between the two patient groups. Influences of contrast medium on severity of disease were detected by monitoring complications during the course of treatment, C-reactive protein, and APACHE II score. RESULTS: The 1-month mortality rate was less in patients with CECT (6.4% versus 15.8%, p <0.05). There were no significant differences considering the incidence of additional complications, and hospital stay was not significantly longer (29 +/- 36 versus 19 +/- 13 days). C-reactive protein and APACHE II score had similar time courses. CONCLUSION: Contrast-enhanced computed tomography remains crucial in identifying patients with acute pancreatitis at high risk to develop necrosis of the pancreas and systemic complications. Contrast medium has been found to aggravate acute pancreatitis in animal models. As compared with the patient group without being exposed to contrast medium, however, this study did not show a deterioration of acute pancreatitis by administration of contrast medium in men.