639 research outputs found
The epidemiology of inflammatory bowel disease: Clues to pathogenesis?
Historically, inflammatory bowel disease (IBD) was most common in North America and Europe and more common with a north-south gradient. Over the past century, there has been a marked increase in IBD in general and in childhood IBD in particular and over the past 50 years IBD has spread into the developing world. The greatest risk factor of developing IBD is an affected family member. Concordance rates between dizygotic twins is ∼4% and ∼50% in monozygotic twins, and more than half of pairs are diagnosed within 2 years of each other. Nevertheless, most patients with IBD do not have an affected family member. More than 200 genes are associated with an increased risk for IBD, but most associations are weak with odds ratios between 1.2 and 2.0 suggesting the environment plays a role. IBD is more common in urban than rural regions and is associated with “good standards” of domestic hygiene during childhood. People who migrate from areas with a low incidence to areas with a high incidence of IBD have an increased risk of developing IBD and the younger they are when they migrate, the greater their risk of developing IBD. Moreover, people who migrate from regions with a high incidence to areas with a low incidence of IBD have a decreased risk of developing IBD. Together, these findings strongly suggest particular environmental exposures occurring early in life may trigger inflammatory bowel disease in genetically susceptible individuals. The key is figuring out what those exposures might be
Matrix-free calcium in isolated chromaffin vesicles
Isolated secretory vesicles from bovine adrenal medulla contain 80 nmol of Ca2+ and 25 nmol
of Mg2+ per milligram of protein. As determined with a Ca2+-selective electrode, a further accumulation
of about 160 nmol of Ca2+/mg of protein can be attained upon addition of the Ca2+ ionophore A23187.
During this process protons are released from the vesicles, in exchange for Ca2+ ions, as indicated by the
decrease of the pH in the incubation medium or the release of 9-aminoacridine previously taken up by the
vesicles. Intravesicular Mg2+ is not released from the vesicles by A23 187, as determined by atomic emission
spectroscopy. In the presence of N H Q , which causes the collapse of the secretory vesicle transmembrane
proton gradient (ApH), Ca2+ uptake decreases. Under these conditions A23 187-mediated influx of Ca2+
and efflux of H+ cease at Ca2+ concentrations of about 4 pM. Below this concentration Ca2+ is even released
from the vesicles. At the Ca2+ concentration at which no net flux of ions occurs the intravesicular matrix
free Ca2+ equals the extravesicular free Ca2+. In the absence of NH4C1 we determined an intravesicular
pH of 6.2. Under these conditions the Ca2+ influx ceases around 0.15 pM. From this value and the known
pH across the vesicular membrane an intravesicular matrix free Ca2+ concentration of about 24 pM was
calculated. This is within the same order of magnitude as the concentration of free Ca2+ in the vesicles
determined in the presence of NH4C1. Calculation of the total Ca2+ present in the secretory vesicles gives
an apparent intravesicular Ca2+ concentration of 40 mM, which is a factor of lo4 higher than the free
intravesicular concentration of Ca2+. It can be concluded, therefore, that the concentration gradient of free
Ca2+ across the secretory vesicle membrane in the intact chromaffin cells is probably small, which implies
that less energy is required to accumulate and maintain Ca2+ within the vesicles than was previously
anticipated
Cd19-negative relapse of pediatric b-cell precursor acute lymphoblastic leukemia following blinatumomab treatment
Standardised proformas improve patient handover: Audit of trauma handover practice
<p>Abstract</p> <p>Background</p> <p>The implementation of the European Working Time Directive has meant the introduction of shift patterns of working for junior doctors. Patient handover between shifts has become a necessary part of practice in order to reduce the risk of medical errors. Data handed over between shifts are used to prioritise clinical jobs outstanding, and to create theatre lists. We present a closed-loop audit of handover practice to assess whether standardised proformas improve clinical data transfer between shifts during handover in our Orthopaedic Unit.</p> <p>Methods</p> <p>We collected data handed over between shifts for a period of one week at our department. The data were in the form of hand written data on plain paper used to assist verbal handover. Data were analysed and a standardised handover sheet was trialled. After feedback from juniors the sheet was revised and implemented. A re-audit, of handover data, was then undertaken using the revised standardised proforma during a period of 1 week.</p> <p>Results</p> <p>Forty-eight patients were handed over in week 1 while 55 patients were handed over during re-audit. The standardised proformas encouraged use of pre-printed patient labels which contained legible patient identifiers, use of labels increased from 72.9% to 93.4%. Handover of outstanding jobs increased from 31.25% to 100%. Overall data handed over increased from 72.6% to 93.2%. Handover of relevant blood results showed little improvement from 18.8% to 20.7%</p> <p>Conclusion</p> <p>This audit highlights the issue of data transfer between shifts. Standardised proformas encourage filling of relevant fields and increases the data transferred between shifts thereby reducing the potential for clinical error cause by shift patterns.</p
The workload of web-based consultations with atopic eczema patients at home
Abstract Background Atopic eczema is a chronic inflammatory non-contagious skin disease characterised by intensive itch and inflamed skin. Due to its chronic and relapsing course atopic eczema imposes a great burden on affected families. Review articles about home care telemedicine have indicated advantageous effects of home telehealth. However, few studies have investigated how home care telemedicine applications affect the workload of the clinician. Methods The use of a web-based counselling system was recorded through computerised logging. The doctor who answered the requests sent via the Internet recorded the amount of time needed for reading and answering 93 consecutive requests. Results The time needed by the physician to read and answer a request was less than 5 minutes in 60% of the cases. The doctor spent significantly more time to answer requests that had photographs attached compared to requests without photographs (P = 0.005). The time needed to answer requests received during the winter season (October-March) was significantly longer than the rest of the year (P = 0.023). There was no correlation between the answering time and the age of the patient. Conclusions Individual web-based follow-up of atopic eczema patients at home is feasible. The amount of time needed for the doctor to respond to a request from the patient appears to be small. The answering time seems to depend on whether photographs are supplied and also on seasonal variations of disease activity. Since the management of atopic eczema is complex involving many different types of treatments and educational aspects, we expect this type of communication to be useful also to other chronic disease patients requiring close follow-up.</p
On the origin of negative target currents during laser ablation of polyethylene
The exposure of a target to a focused laser beam results in the occurrence of a time-varying current between the target itself and the grounded vacuum chamber. This current is composed by three distinct phases, namely the ignition phase, in which the laser pulse drives the electron emission, while electrons coming from the ground through the target holder balance the positive charge generated on the target. The active phase appears at post-pulse times and it is characterized by the presence of peaked structures in the time-resolved current, representing characteristics of the target composition. Lastly, the afterglow phase is determined by a current of electrons flowing from the target to the ground. During the active phase of the target current resulting from polymers ablation with an UV KrF laser, negative target current peaks are observed, whose origin is still unknown. We investigate the dependence of these current structures on the dimensions of the target, using ultra-high molecular weight polyethylene disks of different thickness
Technical advances in flow cytometry-based diagnosis and monitoring of paroxysmal nocturnal hemoglobinuria
Magnetic field exposure and long-term survival among children with leukaemia
We examined the association between magnetic field (MF) exposure and survival among children with acute lymphoblastic leukaemia (ALL) treated at 51 Pediatric Oncology Group centres between 1996 and 2001. Of 1672 potentially eligible children under treatment, 482 (29%) participated and personal 24-h MF measurements were obtained from 412 participants. A total of 386 children with ALL and 361 with B-precursor ALL were included in the analysis of event-free survival (time from diagnosis to first treatment failure, relapse, secondary malignancy, or death) and overall survival. After adjustment for risk group and socioeconomic status, the event-free survival hazard ratio (HR) for children with measurements ⩾0.3 μT was 1.9 (95% confidence interval (CI) 0.8, 4.9), compared to <0.1 μT. For survival, elevated HRs were found for children exposed to ⩾0.3 μT (multivariate HR=4.5, 95% CI 1.5–13.8) but based on only four deaths among 19 children. While risk was increased among children with exposures above 0.3 μT, the small numbers limited inferences for this finding
Predicting residents' performance: A prospective study
BACKGROUND: Objective criteria for predicting residents' performance do not exist. The purpose of this study was to test the hypothesis that global assessment by an intern selection committee (ISC) would correlate with the future performance of residents. METHODS: A prospective study of 277 residents between 1992 and 1999. Global assessment at the time of interview was compared to subsequent clinical (assessed by chief residents) and cognitive performance (assessed by the American Board of Pediatrics in-service training examination). RESULTS: ISC ratings correlated significantly with clinical performance at 24 and 36 months of training (r = 0.58, P < .001; and r = 0.60, P < .001 respectively). ISC ratings also correlated significantly with in-service exam scores in the 1(st), 2(nd), and 3(rd) years of training (r = 0.35, P = .0016; r = 0.39, P = 0.0003; r = 0.50, P = 0.005 respectively). CONCLUSIONS: Global assessment by an ISC predicted residents' clinical and cognitive performances
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