Citations

Background. Although glucose-6-phosphate dehydrogenase (G-6-PD) deficiency is prevalent in African Americans, their risk of associated neonatal hyperbilirubinemia has not been prospectively studied.Objective. To compare hemolysis and the risk of hyperbilirubinemia among African American, G-6-PD-deficient neonates (study group) and G-6-PD-normal control subjects.Methods. Consecutive, healthy, term and near-term, male neonates born to African American mothers comprised the patient cohort. G-6-PD testing was performed with umbilical cord blood samples. Routine management included measurement of the end tidal carbon monoxide level corrected for ambient carbon monoxide level (ETCOc) within 4 hours after delivery (assessment of hemolysis), ≥1 predischarge bilirubin determination, and additional bilirubin testing as clinically indicated. Indications for phototherapy were identical for study patients and control subjects. Neonates were monitored for the first 1 week of life. ETCOc results, the incidence of hyperbilirubinemia (defined as a transcutaneous or plasma total bilirubin concentration of ≥95th percentile for the hour of life), and the need for phototherapy were compared between the G-6-PD-deficient and G-6-PD-normal groups.Results. Five hundred male patients were enrolled, of whom 64 (12.8%) were G-6-PD-deficient. ETCOc values (median and interquartile range) were higher among G-6-PD-deficient neonates than among control neonates (2.4 ppm [2.0–2.9 ppm] vs 2.1 ppm [1.7–2.5 ppm]). More G-6-PD-deficient neonates developed hyperbilirubinemia than did control subjects (14 of 64, 21.9%, vs 29 of 436, 6.7%; relative risk: 3.27; 95% confidence interval: 1.83-5.86), whereas 13 (20.3%) met the criteria for phototherapy, compared with 25 control subjects (5.7%) (relative risk: 3.53; 95% confidence interval: 1.91-6.56). No cases of kernicterus were observed.Conclusions. Within the African American neonatal population, there is a subgroup of G-6-PD-deficient infants with elevated rates of hemolysis, a higher incidence of hyperbilirubinemia, and a greater requirement for phototherapy, compared with G-6-PD-normal control subjects. These newborns should be monitored vigilantly for the development of hyperbilirubinemia.

Objectives. To characterize the clinical features, results of diagnostic testing, and treatment outcomes for children and adolescents with rumination syndrome. Methods. Review of the medical records for all 147 patients ages 5 to 20 diagnosed with rumination syndrome at our institution between 1975 and 2000. Data are presented as mean ± the standard error of the mean. Results. Sixty-eight percent were female. Age at diagnosis was 15.0 ± 0.3 years. Symptom duration before diagnosis was 2.2 ± 0.3 years, 73% missed school/work, and 46% had been hospitalized because of symptoms. Before diagnosis, 16 (11%) underwent surgery for evaluation or management of symptoms. Twenty-four (16%) had psychiatric disorders; 3.4% had anorexia or bulimia nervosa. All patients described postprandial regurgitation after almost every meal (2.7 ± 0.1 meals per day). Weight loss was described by 42.2% (median: 7 kg). Additional symptoms included: abdominal pain, 38%; constipation, 21%; nausea, 17%; and diarrhea, 8%. Structural studies were normal. Gastric emptying of solids at 4 hours was delayed in 26 of 56 patients. Esophageal pH testing in 24 patients showed reflux/regurgitation in 54%. Gastroduodenal manometry in 65 patients showed characteristic rumination-waves in 40%. Outcome data (at median follow-up 10 months) were available for 54 patients. Symptoms resolved in 16 (30%) and improved in 30 (56%). Conclusions. Recognition of the clinical features of rumination syndrome in children and adolescents is essential; the diagnosis is often delayed and associated with morbidity. Extensive diagnostic testing is unnecessary. Early behavioral therapy is advocated, and patient outcomes are generally favorable.

Objective. To determine whether children with pallid breath-holding spells associated with bradycardia can be treated safely and successfully with permanent pacemaker implantation. Methods. The records of pediatric patients who had apparent breath-holding spells and associated bradycardia and were treated with permanent pacemaker implantation were reviewed. Results. Ten pediatric patients with apparent breath-holding spells associated with bradycardia were treated with a permanent ventricular demand pacemaker at the Mayo Clinic between 1985 and 1995. Patients had onset of symptoms between ages 6 days and 12 months and presented for evaluation between ages 12 months and 5 years. Duration of spells was 15 seconds to 10 minutes. Medications to prevent spells were unsuccessful. Electrocardiograms documented asystolic pauses of 1.7 to 24 seconds (mean: 11.9 seconds). Permanent ventricular demand pacemakers were implanted at 10 months to 5 years of age (median: 14.5 months): 9 endocardial and 1 epicardial. Three patients required pacemaker revision. At follow-up of 38 to 170 months (median: 65.5), 5 patients had complete resolution of spells, 2 had only mild color change without loss of consciousness or seizure activity, and 3 continued to have minor brief spells. Conclusions. Permanent pacemaker therapy for children with pallid breath-holding spells associated with severe bradycardia is safe, efficacious, and warranted.

Objective. Inherited long QT syndrome (LQTS) may present with syncope, seizures, and/or sudden death as a result of ventricular tachyarrhythmias. Identification of family members who are at risk because they harbor the genetic substrate for LQTS is critical. Presently, such identification relies on the 12-lead electrocardiogram (ECG). The purpose of this study was to evaluate the efficacy of the automated ECG as a screening tool for LQTS. Method. Molecular testing of a proband and 22 additional family members for the KVLQT1 mutation and symptomatic status facilitated the classification of each family member into the following patient groups: noncarriers (13), asymptomatic carriers (5), and symptomatic carriers (5). Each individual had a standard 12-lead ECG from which the computer and manual (lead II) corrected QT interval were determined. In addition, we determined the accuracy of the computer ECG diagnostic interpretation for each patient group. Results. With the use of a corrected QT interval of ≥460 ms as a diagnostic cutoff, the positive and negative predictive values for identifying at-risk individuals were 100%. Despite this, the computer-generated ECG diagnostic interpretation erroneously classified 6 of 23 family members. Moreover, half of the family members, proved to have the ion channel defect, received the diagnostic interpretation “normal ECG.” Conclusion. Reliance on the computer-generated ECG diagnostic interpretation alone will fail to identify many at-risk family members. It is suggested that all first-degree relatives of an identified LQTS proband have a 12-lead ECG that is reviewed independently by a physician who is familiar with LQTS in an effort to improve screening for this potentially lethal syndrome.electrocardiogram, long QT syndrome, QT interval, sudden death.

Objective. To determine parents' knowledge and attitudes of medicolegal issues affecting adolescent medical care. Design. An anonymous, mailed survey with 16 questions concerning Minnesota consent and confidentiality laws that affect adolescents' medical care. Setting. A community of >70 000 in rural, southeastern Minnesota. Participants. Parents of 600 randomly selected 7th- through 12th-grade public school students. Results. Two hundred eighty-eight (48%) parents returned the surveys. Parents achieved a median score of 18.8% (range, 0%–93.8%) correct on a test of knowledge. Opinion was a median of +0.3 on a scale where −1 signified “a bad law,” 0 signified “neither a good nor bad law,” and +1 signified “a good law.” Four questions, however, generated a more intense response. Seventy-seven percent of parents reported that, as a whole, the laws in the survey had no effect on them and/or their children. Conclusions. These results suggest that parents are not knowledgeable of Minnesota laws that affect adolescent medical care. Overall opinion of these laws was mildly positive, with notable exceptions. Parents also lack a sense of impact of laws affecting adolescent medical care. Lack of knowledge and the presence of certain attitudes allow for identification of issues that clinicians should address by incorporating medicolegal education into the care of adolescents and their families. These results are especially timely in light of the Parental Rights and Responsibilities Act under consideration in Congress, which would provide parents greater authority over their children's medical care.

Objective— Mechanisms of renal injury distal to renal artery stenosis (RAS) remain unclear. We tested the hypothesis that it involves microvascular remodeling consequent to increased oxidative stress. Methods and Results— Three groups of pigs (n=6 each) were studied after 12 weeks of RAS, RAS+antioxidant supplementation (100 IU/kg vitamin E and 1 g vitamin C daily), or controls. The spatial density and tortuousity of renal microvessels (<500 μm) were tomographically determined by 3D microcomputed tomography. The in situ production of superoxide anion and the expression of vascular endothelial growth factor (VEGF), its receptor VEGFR-2, hypoxia-inducible-factor (HIF)-1α, von Hippel-Lindau (VHL) protein, and NAD(P)H oxidase (p47phox and p67phox subunits) were determined in cortical tissue. RAS and RAS+antioxidant groups had similar degrees of stenosis and hypertension. The RAS group showed a decrease in spatial density of cortical microvessels, which was normalized in the RAS+antioxidant group, as was arteriolar tortuousity. RAS kidneys also showed tissue fibrosis (by trichrome and Sirius red staining), increased superoxide anion abundance, NAD(P)H oxidase, VHL protein, and HIF-1α mRNA expression. In contrast, expression of HIF-1α, VEGF, and VEGFR-2 protein was downregulated. These were all significantly improved by antioxidant intervention. Conclusions— Increased oxidative stress in the stenotic kidney alters growth factor activity and plays an important role in renal microvascular remodeling, which can be prevented by chronic antioxidant intervention.