Faculty Bibliography

PURPOSE: To assess the incremental value of the left-side-down decubitus view in radiographic evaluation of ileocolic intussusception. MATERIALS AND METHODS: The institutional review board approved this retrospective investigation with waiver of informed consent. Between February 24, 2002, and January 25, 2007, 304 studies (300 patients; mean age, 1.3 years; range, 0.1-3.9 years) met the following inclusion criteria: kidney ureter bladder (KUB) and decubitus views obtained, with subsequent proof of diagnosis. Using a consensus approach, two pediatric radiologists evaluated KUB and decubitus views for four variables: (a) discrete mass and (b) small-bowel obstruction (positive criteria); (c) air or stool in ascending colon and (d) cecal air or stool (negative criteria). On the basis of these criteria, each study was graded as negative, positive, or indeterminate for intussusception. Diagnostically determinate studies and the ability to visualize or exclude intussusception were calculated to determine sensitivity and specificity. The difference between proportions was calculated, along with 95% confidence intervals. Agreement between the supine KUB view and supine KUB plus left-side-down decubitus views was tested with the McNemar test. RESULTS: Intussusception was present in 58 of 304 studies (19%). Adding the decubitus view to the KUB view increased the number of determinate studies from 110 of 304 (36.2%) to 205 of 304 (67.4%) (difference, 31.2 percentage points; P < .001). Intussusception was correctly identified with KUB view alone in 35 of 58 studies (60.3%); this value increased to 43 of 58 (74.1%) with KUB plus decubitus views (P = .0215). Intussusception was correctly excluded with the KUB view alone in 63 of 246 studies (25.6%); this increased to 143 of 246 studies (58.1%) with addition of the decubitus view (P < .0001). CONCLUSION: The addition of decubitus views increased the number of diagnostically determinate studies and increased the ability to diagnose or exclude intussusception. The authors believe that a left-side-down decubitus view should be included in the initial evaluation of patients suspected of having intussusception, particularly when the supine view is diagnostically indeterminate

CYP4A11 arachidonic acid monooxygenase oxidizes endogenous arachidonic acid to 20-hydroxyeicosatetraenoic acid, a renal vasoconstrictor and natriuretic. Cyp4a deficiency causes hypertension in male mice, and a loss-of-function variant (T8590C) of CYP4A11 is associated with hypertension in white individuals. Hypertension and hypertensive renal disease are more common among black than white individuals, but the relationship between genetic variation at CYP4A11 and hypertension in black individuals is not known. This study tested the hypothesis that the CYP4A11 T8590C polymorphism is associated with higher BP or clinical outcomes in 732 black Americans with hypertensive renal disease participating in the African American Study of Kidney Disease (AASK). Men with the 8590CC genotype had significantly higher systolic BP (CC 156.5 +/- 22.6 versus 148.4 +/- 24.3 mmHg in CT and TT combined; P = 0.04) and pulse pressure (P = 0.04) at baseline; this association was not observed among women. In addition, this genotype was associated with higher systolic and diastolic BP at 36-mo follow-up among those randomly assigned to the lower BP arm of the AASK. Among all participants (or men but not women) with proteinuria, the 8590CC genotype was associated with an increased cumulative incidence of ESRD or death, controlling for randomization and clinical characteristics. In summary, the CYP4A11 8590CC genotype is associated with increased BP in black men with hypertensive nephrosclerosis and is associated with adverse clinical outcomes in those with baseline proteinuria. These data support a role for renal monooxygenases and 20-hydroxyeicosatetraenoic acid in the regulation of BP and renal function in men.

AIM: To determine reliable magnetic resonance imaging (MRI) features differentiating three paediatric intra-articular congenital or neoplastic synovial lesions that contain blood products, from post-traumatic or haemorrhagic inflammatory processes. MATERIALS AND METHODS: This was a retrospective review of MRI findings of 22 paediatric intra-articular congenital or neoplastic synovial lesions, including venous malformation (VM) (n=12), pigmented villonodular synovitis (PVNS; n=8), and synovial sarcoma (SS; n=2). These MRI features were compared with 22 paediatric post-traumatic or inflammatory intra-articular processes containing blood products and producing mass effect. The following imaging features were assessed: presence of a discrete mass, extension, extra-articular oedema, susceptibility, joint effusion, and size. Fisher's exact test was used and results were considered statistically significant when p<0.05. RESULTS: The three intra-articular synovial lesions, compared with controls, were more likely to directly invade osseous structures when a discrete mass was present (13/16, 81.3% versus 1/9, 11.1%; p<0.002) and extend into extra-articular soft tissues (13/21, 61.9% versus 2/17, 11.8%; p<0.003), but were less likely to show extra-articular oedema (3/22, 13.6% versus 13/22, 59.1%; p<0.004), a joint effusion (10/22,45.5% versus 19/22, 86.4%, p<0.01), susceptibility within a joint effusion (0/22, 0% versus 11/22, 40.9%; p=0.00), osseous oedema (3/16, 18.8% versus 7/9, 77.8%; p<0.009), and synovial enhancement (8/21, 38.1% versus 14/16, 87.5%; p<0.003). VMs had characteristic tubular vessels with internal fluid-fluid levels (11/12) that extended into bone (10/12) and extracapsular soft tissues (11/12). CONCLUSION: Our study indicates that, despite the overlapping presence of haemorrhagic products, intra-articular VM, PVNS, and SS show MRI features that permit distinction from acquired post-traumatic and haemorrhagic inflammatory lesions

PURPOSE/OBJECTIVE:We hypothesized that functional TGFbeta1 SNPs increase TGFbeta/BMP signaling imbalance in BMPR2 mutation heterozygotes to accelerate the age at diagnosis, increase the penetrance and SMAD2 expression in familial pulmonary arterial hypertension. METHODS:Single nucleotide polymorphism genotypes of BMPR2 mutation heterozygotes, age at diagnosis, and penetrance of familial pulmonary arterial hypertension were compared and SMAD2 expression was studied in lung sections. RESULTS:BMPR2 mutation heterozygotes with least active -509 or codon 10 TGFbeta1 SNPs had later mean age at diagnosis of familial pulmonary arterial hypertension (39.5 and 43.2 years) than those with more active genotypes (31.6 and 33.1 years, P = 0.03 and 0.02, respectively). Kaplan-Meier analysis also showed that those with the less active single nucleotide polymorphisms had later age at diagnosis. BMPR2 mutation heterozygotes with nonsense-mediated decay resistant BMPR2 mutations and the least, intermediate and most active -509 TGFbeta1 SNP genotypes had penetrances of 33, 72, and 80%, respectively (P = 0.003), whereas those with 0-1, 2, or 3-4 active single nucleotide polymorphism alleles had penetrances of 33, 72, and 75% (P = 0.005). The relative expression of TGFbeta1 dependent SMAD2 was increased in lung sections of those with familial pulmonary arterial hypertension compared with controls. CONCLUSIONS:The TGFbeta1 SNPs studied modulate age at diagnosis and penetrance of familial pulmonary arterial hypertension in BMPR2 mutation heterozygotes, likely by affecting TGFbeta/BMP signaling imbalance. This modulation is an example of Synergistic Heterozygosity.

OBJECTIVES: The purpose of this work was to determine the utility of total lower extremity radiographs versus dedicated tibia radiographs in the evaluation of the young child presenting with nonweight bearing without localizing signs. METHODS: This was an institutional review board-approved retrospective review of 263 consecutive patients between the ages of 9 months and 4 years who were referred for total lower extremity radiography between September 29, 2001, and November 7, 2006. Among these, a total of 133 study subjects met inclusion criteria of presentation with nonweight bearing without localizing signs or history of previous trauma. The control population was selected from 1089 consecutive patients between the ages of 9 months and 4 years evaluated from January 5, 1999 and December 8, 2006, who had only tibia radiographs at presentation. From this group, a final control population of 128 patients was selected with similar presentation of nonweight bearing without localizing signs or history of previous trauma. Causes of nonweight bearing were recorded for both groups based on radiograph findings and additional studies performed during workup. RESULTS: At initial presentation, fractures were present in 13 study patients (9.8%) and in 23 control patients (17.9%). Total fractures (when including follow-up) were present in 14 study patients (10.5%) and in 26 control patients (20.3%). Fractures were located in the tibia alone in 100% of patients in the study group. Extratibial fracture (metatarsal) was present in 1 patient in the control group (0.7%). Among the study group, additional diagnoses included rickets (n = 1), cerebellar ataxia (n = 1), and discitis with epidural abscess (n = 1). CONCLUSIONS: Our study findings indicate that the diagnostic value of total lower extremity radiography is similar to dedicated tibia radiography in the workup of the nonweight-bearing young child without trauma history or localizing signs. Radiation and cost savings can be realized by reserving additional radiographs for patients with high clinical suspicion and normal findings on dedicated tibia radiography

Biomarkers of inflammation, especially C-reactive protein (CRP), have been consistently shown to predict poor outcomes in chronic hemodialysis (CHD) patients. However, the determinants of CRP and the value of its monitoring in CHD patients have not been well defined. We conducted a retrospective cohort study to evaluate possible determinants of the inflammatory response in CHD patients with a focus on dialysis catheter utilization. Monthly CRP were measured in 128 prevalent CHD patients (mean age 56.6 years [range 19-90], 68% African Americans, 39% diabetics [DM]) over a mean follow-up of 12 months (range 2-26 months). There were a total of 2405 CRP measurements (median 5.7 mg/L; interquartile range [IQR] 2.4-16.6 mg/L). The presence of a dialysis catheter (p<0.002), cardiovascular disease (p=0.01), male gender (p=0.005), higher white blood cell count (p<0.0001), elevated phosphorus (p=0.03), and lower cholesterol (p=0.02) and albumin (p<0.0001) concentrations were independent predictors of elevated CRP in the multivariate analysis. Additionally, CRP levels were significantly associated with the presence of a catheter, when comparing the levels before and after catheter insertion (p=0.002) as well as before and after catheter removal (p=0.009). Our results indicate that the presence of a hemodialysis catheter is an independent determinant of an exaggerated inflammatory response in CHD patients representing a potentially modifiable risk factor.

Multiple system atrophy (MSA) is a neurodegenerative disorder of unknown etiology characterized by extrapyramidal, pyramidal, cerebellar, and autonomic dysfunction in any combination. We report a patient with a 4-year history of MSA who developed dementia associated with sporadic Creutzfeldt-Jakob disease (CJD). Our proband was MM homozygous for the M129V polymorphism within the prion protein gene (PRNP), a known risk factor for CJD. We conducted a case-control study to test the hypothesis that homozygosity for the M129V polymorphism of PRNP occurs more frequently in MSA in comparison to Parkinson's disease and healthy volunteers. A total of 63 patients with MSA, 54 age-, race- and gendermatched controls with Parkinson's disease, and 126 matched healthy volunteers were studied. The genotype analysis revealed no significant difference in the codon 129 genotype distribution in MSA as compared to controls. Nonetheless, the frequencies of the MM and VV genotypes were higher in MSA than in Parkinson's disease. Thus, homozygosity, particularly VV homozygosity, at codon 129 of PRNP is associated with MSA compared to a clinically related but pathophysiologically distinct alpha-synucleinopathy. Considering the possibility that the prion protein contributes to the pathogenesis of MSA would require confirmation of these findings in an independent patient population.

BACKGROUND:National guidelines recommend targeted tuberculin testing and treatment of latent tuberculosis infection (LTBI) among high-risk groups but discourage testing low-risk persons. METHODS:We determined the LTBI prevalence (tuberculin skin test [TST] reaction > or = 10 mm) among adults with and without TB exposure risk factors screened in Tennessee from 1/2/2002 to 4/19/2005. We then quantified LTBI risk among groups at high-risk for TB using multivariate analysis. RESULTS:Of 53,061 adults tested, the LTBI prevalence was 34% among foreign-born persons, compared with 3.2% among nonforeign-born persons (prevalence odds ratio [POR] 15.7, 95% confidence interval [CI] 14.5-16.8). Among nonforeign-born adults, Asian race (POR 11.7, 95% CI 5.9-23.4), and Hispanic ethnicity (POR 11.7, 95% CI 9.0-15.2) were most strongly associated with LTBI. Only 2.4% of low-risk persons had LTBI. CONCLUSIONS:Risk-based screening can effectively distinguish persons who will benefit from LTBI testing and treatment. Targeted testing programs should prioritize foreign-born persons. Testing of low-risk persons is unnecessary.

We describe new families of discrete distributions that are used to model sums of exchangeable Bernoulli random variables. These discrete distributions can be parameterized in terms of their range, mean, variance, and shape parameters. These models are fitted to an example involving mortality rates for children in a survey of families in Brazil. The methods illustrate that mortality rates in this survey increase with family size and that the correlation of within-family mortality status also depends on the family size. These methods are also applied to a laboratory study of birth defects in mice.

We examined the effect of -58 C/T and BE1 +9/-9 polymorphisms in the bradykinin B2 receptor gene on forearm vascular resistance (FVR) before and during intrabrachial artery infusion of the B2 receptor-, endothelium-dependent agonist bradykinin and the endothelium-independent agonist sodium nitroprusside in 228 normotensive subjects. In 166 white Americans, systolic blood pressure (SBP) and pulse pressure were highest in the BE1 +9/+9 group (118+/-2 and 51+/-2 mm Hg, respectively; P<0.05 versus -9/-9 for either), intermediate in the +9/-9 group (114+/-1 and 49+/-1 mm Hg, P<0.05 versus -9/-9 for pulse pressure), and lowest in the -9/-9 group (110+/-2 and 44+/-2 mm Hg). In 62 black Americans, FVR was 25% higher in the BE1 +9/+9 group compared with the BE1 +9/-9 and -9/-9 groups at baseline (P=0.038) or during bradykinin (P=0.03). Increased SBP or vascular resistance may contribute to increased left ventricular mass reported previously in individuals with the BE1+9/+9 genotype.