Airway interventions in children with Pierre Robin Sequence

OBJECTIVE: To describe the interventions required for successful airway management in children with Pierre Robin Sequence (PRS). STUDY DESIGN: Case series. SUBJECTS AND METHODS: The records of both a cleft and craniofacial clinic and a pediatric otolaryngology clinic were searched, and all children with PRS were identified. Data concerning feeding interventions, airway interventions, and comorbid conditions were extracted. RESULTS: Seventy-four cases of PRS were identified. Thirty-eight of the 74 children required airway intervention other than prone positioning. Fourteen of these 38 were managed nonsurgically with nasopharyngeal airway and/or short-term endotracheal intubation, whereas the remaining 24 required surgical intervention. Eighteen of the 24 underwent distraction osteogenesis of the mandible, one underwent tracheostomy, and five underwent tracheostomy followed by eventual distraction. CONCLUSION: In our series, over 50 percent of children with PRS required an airway intervention. These were both nonsurgical and surgical. As otolaryngologists, we must be prepared for the challenges children with PRS may present and the interventions that may be necessary to successfully manage these difficult airways.     

Student USMLE Step 1 Preparation and Performance

Objectives: Many medical students take commercial preparation courses to prepare for the USMLE Step 1. This investigation examined the relationships among Step 1 performance, preparation method, and academic achievement in medical school. Method: A survey was conducted on 148 junior students at a medical school in July 2000 regarding their preparation methods for Step 1. Additional data was collected on student Step 1 scores, attendance record on preparation courses, and course grades in medical school. Results: One hundred students (68%) responded to the survey including 32 preparation course participants. Course participants had significantly lower Step 1 scores and second-year GPAs than those of the non-participants (p < 0.05). However, the effect of preparation method was not significant by using ANCOVA when the second-year GPA was used as a covariate (p = 0.71). Conclusion: Performance on Step 1 is related to academic performance in medical school and not the type of preparation methods.     

Why and how to improve physical activity promotion: Lessons from behavioral science and related fields

This commentary highlights the importance of regular physical activity to the nation’s health and discusses some of the major challenges and opportunities currently facing the field.     

Role of Plasma Vasopressin in Impaired Water Excretion of Glucocorticoid Deficiency

In the present study, the effect of selective glucocorticoid deficiency on renal water excretion was investigated in conscious, trained, adrenalectomized dogs. The animals were studied before and after a water load while on replacement therapy of desoxycorticosterone acetate, 5 mg/day, and dexamethasone, 0.8 mg/day (group I), and while off dexamethasone for 5-9 days (group II). Before the water load the weight, inulin space, cardiac output, blood pressure, glomerular filtration rate, renal blood flow, plasma osmolality, and plasma antidiuretic hormone measured by radioimmunoassay were similar in both groups I and II. However, after a 40 ml/kg water load a marked impairment in renal water excretion in the glucocorticoid deficient dogs became apparent. Maximal free water clearance was −0.046±0.16 vs. 6.51±0.72 ml/min (P < 0.001) and minimal urinary osmolality was 425±56 vs. 82±3.5 mosmol/kg H₂O (P < 0.001) in group II as compared to group I. Plasma antidiuretic hormone was maximally suppressed during the water load in group I to 0.34±0.08 pg/ml but remained elevated at 9.18±1.79 pg/ml (P < 0.005) in group II. This nonsuppressibility of plasma antidiuretic hormone during water loading in group II was associated with a significant tachycardia of 145±6 vs. 87±6 beats/min (P < 0.001) in group I and a significantly lower stroke volume of 27±0 vs. 59±0.5 ml/beat (P < 0.001). In conclusion, our results implicate a persistent secretion of antidiuretic hormone as an important factor in the impaired water excretion of glucocorticoid deficiency. A deleterious effect of glucocorticoid deficiency on cardiac function was observed and this hemodynamic alteration could be involved in initiating a nonosmolar, baroreceptor-mediated release of vasopressin.     

Specific phobia and comorbid depression: a closer look at the National Comorbidity Survey data

Previous studies examining the relationship between specific phobia and major depression have reported mixed findings. The results of some studies have suggested that specific phobia is associated with a higher prevalence of comorbid depression, whereas others have found no association. The purpose of this study was to further examine whether specific phobia is an independent contributor to major depression by using data from the National Comorbidity Survey, a household probability sample of adults (n = 5877) aged 15 to 54 years in the United States. After adjusting for demographic differences and comorbid mental disorders, multiple logistic regression analyses confirmed that specific phobia remains positively associated with comorbid depression (odds ratio, 1.9; 95% confidence interval, 1.6-2.4). Additional analysis found this relationship to be specific to individuals with a fear of heights, animals, and closed spaces, as well as those endorsing at least 2 irrational fears. These results suggest that the types and number of fears play an important role in the probability of lifetime depression.     

Mutagenicity studies with N-acetyl-l-aspartic acid

Analytical studies have reported that N-acetyl-l-aspartic acid (NAA) is present at low concentrations in many foods. The current studies were conducted to assess the mutagenicity of NAA using standard OECD guideline in vitro bacterial and in vivo mammalian mutagenicity studies. For comparison and control data, mutagenicity studies were also conducted with its constituent amino acid l-aspartate (ASP) because NAA is metabolized to ASP. The combination of an in vitro method for assessing point mutations in bacteria and an in vivo method to assess clastogenicity in an animal model provided adequate evidence for mutagenicity hazard assessment of NAA. No evidence of mutagenicity was observed in either test system with either NAA or ASP. The results from the current studies demonstrate that the presence of NAA in foods is not likely to represent a risk for mutagenicity.