Competing functions encoded in the allergy-associated F(c)epsilonRIbeta gene

Allergic reactions are triggered via crosslinking of the high-affinity receptor for immunoglobulin E, F(c)epsilonRI. In humans, F(c)epsilonRI is expressed as a tetramer (alphabetagamma(2)) and a trimer (alphagamma(2)). The beta subunit is an amplifier of F(c)epsilonRI surface expression and signaling. Here, we show that as a consequence of alternative splicing, the F(c)epsilonRIbeta gene encodes two proteins with opposing and competing functions. One isoform is the full-length classical beta, the other a novel truncated form, beta(T). In contrast to beta, beta(T) prevents F(c)epsilonRI surface expression by inhibiting alpha chain maturation. Moreover, beta(T) competes with beta to control F(c)epsilonRI surface expression in vitro. We propose that the relative abundance of the products of the beta gene may control the level of F(c)epsilonRI surface expression and thereby influence susceptibility to allergic diseases.     

Intraoperative hypercyanosis in a patient with pulmonary artery band: case report and review of the literature

A case of intraoperative cyanosis in a patient with a common atrioventricular canal palliated with a pulmonary artery (PA) band is presented. The patient's physiology was consistent with cyanosis due to inadequate pulmonary blood flow, and responded quickly to typical interventions used for a hypercyanotic episode in a patient with unrepaired Tetralogy of Fallot. Differences and similarities in the physiology of PA banding compared with Tetralogy of Fallot are presented, including a rationale for treatment options for hemodynamic decompensation occurring in the setting of anesthesia and surgery.     

Increased risk of pneumonia among ventilated patients with traumatic brain injury: every day counts!

Background

Patients with traumatic brain injury (TBI) frequently require mechanical ventilation (MV). The objective of this study was to examine the association between time spent on MV and the development of pneumonia among patients with TBI.

Materials and methods

Patients older than 18 y with head abbreviated injury scale (AIS) scores coded 1–6 requiring MV in the National Trauma Data Bank 2007–2010 data set were included. The study was limited to hospitals reporting pneumonia cases. AIS scores were calculated using ICDMAP-90 software. Patients with injuries in any other region with AIS score >3, significant burns, or a hospital length of stay >30 d were excluded. A generalized linear model was used to determine the approximate relative risk of developing all-cause pneumonia (aspiration pneumonia, ventilator-associated pneumonia [VAP], and infectious pneumonia identified by the International Classification of Disease, Ninth Revision, diagnosis code) for each day of MV, controlling for age, gender, Glasgow coma scale motor score, comorbidity (Charlson comorbidity index) score, insurance status, and injury type and severity.

Results

Among the 24,525 patients with TBI who required MV included in this study, 1593 (6.5%) developed all-cause pneumonia. After controlling for demographic and injury factors, each additional day on the ventilator was associated with a 7% increase in the risk of pneumonia (risk ratio 1.07, 95% confidence interval 1.07–1.08).

Conclusions

Patients who have sustained TBIs and require MV are at higher risk for VAP than individuals extubated earlier; therefore, shortening MV exposure will likely reduce the risk of VAP. As patients with TBI frequently require MV because of neurologic impairment, it is key to develop aggressive strategies to expedite ventilator independence.     

Childhood Vitiligo: Clinicoepidemiologic Profile of 268 Children from the Kumaun Region of Uttarakhand,India

Childhood vitiligo differs from adult vitiligo in many clinical parameters. The objective of the current study was to study the clinicoepidemiologic profile of childhood vitiligo and to compare various clinical characteristics of childhood‐ and later‐onset vitiligo. The clinical presentation of vitiligo was examined and analyzed in 762 individuals attending the Dermatology Clinic of Government Medical College, Haldwani, a referral center for the Kumaun region of Uttarakhand state, India, between January 2006 and December 2010. Of the 762 individuals with vitiligo, 268 (35.2%) were children: 152 (56.7%) female and 116 (43.3%) male. The mean age of onset of vitiligo was 6.9 years. A family history of vitiligo was found in 24.3% of children. The most common site of onset was the head and neck (36.9%), followed by the lower limbs and trunk. The most common type of vitiligo observed was acrofacial vitiligo (38.1%), followed by vulgaris, segmental, focal, and mucosal. Leukotrichia was observed in 32.5% of children and Koebner's phenomenon in 24.3%. On comparison of childhood‐ and later‐onset vitiligo, there were statistically significant differences (p < 0.05) in sex, family history, type of vitiligo (segmental and vulgaris), and site of onset. Atopic dermatitis was one of the important cutaneous diseases associated with childhood‐onset vitiligo. Thirty‐five percent of all patients with vitiligo were children (≤12 yrs). Childhood‐onset vitilgo differs from later‐onset vitiligo in many clinical parameters such as sex, family history, types of vitiligo, and sites of onset.