Cushing syndrome due to primary pigmented nodular adrenocortical disease: findings at CT and MR imaging

Primary pigmented nodular adrenocortical disease (PPNAD) is a rare cause of Cushing syndrome in infants, children, and young adults. It is characterized by non-adrenocorticotropic hormone-dependent hypersecretion of cortisol by multiple, pigmented nodules of hyperplastic adrenocortical cells. With a single exception, adrenal glands have been described as normal with computed tomography (CT) in all previous series. Eight patients had Cushing syndrome due to surgically proved PPNAD. Four of the eight patients had stigmas of Carney complex (lentigines, calcified Sertoli cell tumors of the testes, and cardiac and soft-tissue myxomas). CT and/or magnetic resonance (MR) imaging demonstrated unilateral or bilateral nodularity in five of six patients examined. Macronodules (greater than 10 mm) were seen in the two oldest patients. As the clinical presentation of Cushing syndrome in this group of patients may be atypical (severe osteoporosis or short stature), the detection of multiple, small adrenocortical nodules with CT or MR imaging supports, or may even suggest, the diagnosis of PPNAD.     

Unsatisfactory hepatic perfusion after placement of an implanted pump and catheter system: angiographic correlation

Thirty-five patients with scintigrams showing unsatisfactory hepatic artery perfusion after surgical placement of an implanted pump and catheter system were examined with selective angiography (33 cases) or digital subtraction angiography (DSA) during which the contrast material was injected through the side port of the pump (six cases). In 34 of 35 cases, the cause of the unsatisfactory (either extrahepatic or incomplete) hepatic perfusion was defined. DSA was definitive in only two cases, in which extrahepatic flow through collateral vessels was demonstrated. The cause of the perfusion defect was hepatic artery thrombosis in 14 cases, extrahepatic flow through collateral vessels in 14 cases, a misplaced catheter in four cases, and a short proper hepatic artery without adequate length for mixing in two cases. Although hepatic artery perfusion scintigraphy is the primary tool for evaluation of hepatic perfusion after catheter placement, angiography plays an important role in treating the subset of patients with unsatisfactory hepatic perfusion.     

Radioimmunoassay of secretin

The radioimmunoassay methods of secretin are reviewed with respect to production of antibody, preparation of radioactive tracers, and effect of plasma interference. The major difference in the secretin assay methods resides in handling plasma interference. Thus the assay sensitivity decreased markedly when the assay was conducted by diluting plasma samples. When the assay was conducted by compensating for plasma interference with homologous hormone-free plasma, the effect of plasma interference was greatly reduced, leading to a more sensitive assay. However, this method probably can not obtain consistent results with plasma samples collected under various experimental conditions. The method is still subject to considerable desensitization and assay variation. On the other hand, the elimination of plasma interference before assay results in the most sensitive secretin assays capable of detecting consistently a significant postprandial rise in plasma secretin level. It is concluded that a sensitive, validated secretin radioimmunoassay should be one that is capable of detecting increments of plasma secretin in response to doses of intraduodenal acid at 0.055 mEq/min or lower and intravenous administration of exogenous secretin at 0.03 CU/kg/hr with concomitant stimulation of pancreatic bicarbonate and water secretion. With a sensitive and accurate radioimmunoassay for secretin, it is now possible to further investigate the physiology and pathophysiology of secretin.This work was supported by the Genesee Hospital Gastrointestinal Research Fund, NIHAMDD 16939 and 25926.     

Secretion cells in the gastrointestinal tract.

The morphology and distribution of secretin (S) cells were investigated in the human and the dog. S cells were well-visualized by the indired immunofluorescence antibody technique, using a highly specific rabbit anti-secretin sera. The fluorescence reaction was not blocked by an excess amount of gastrin, cholecystokinin, glucagon, vasoactive intestinal polypeptide, or motilin, whereas secretin blocked the reaction. S cells were seen in the mucosa of the antrum and duodenum in both humans and dogs, and throughout the entire length of the canine small intestine. They were not found in the mucosa of the esophagus, fundus of the stomach, or rectum. These cells were either pyramidal in shape or pearshaped and were one-third of the size of gastrin cells. The possible significance of S-cell distribution in the antrum and small intestine is discussed.     

Lignans from Trachelospermum jasminoides

Seven lignans having a diarylhydroxybutyrolactone skeleton were isolated from the leaves and stems of Trachelospermum jasminoides （Lindl.） Lem. Their structures were elucidated to be nortrachelogenin 8＇-O-beta-D-glucopyranoside （1）, nortrachelogenin 5 ＇- C- beta-D-glucopyranoside （2）, trachelogenin amide （3）, nortracheloside, trachelogenin, tracheloside, and trachelogenin 4＇- O- beta-gentiobioside, respectively, on the basis of spectroscopic analyses.     

Appropriate timing of the 14C-urea breath test to establish eradication of Helicobacter pylori infection

OBJECTIVE: The aim of this study was to determine the performance characteristics of the 14C-urea breath test (UBT) performed 2 wk after the completion of therapy for Helicobacter pylori using a 4 to 6 wk study as the gold standard. METHODS: Patients with active Helicobacter pylori infection at four medical centers received proton pump inhibitor-based triple or quadruple therapy for 10-14 days. Patients underwent the 14C-UBT 2 and 4-6 wk after the completion of therapy. A positive test was defined as 14CO2 excretion of >200 dpm, a negative test as <50 dpm, and an equivocal test as >50 but <200 dpm. Performance characteristics of the 2-wk UBT were calculated using the 4 to 6-wk result as a gold standard. RESULTS: Eighty-five patients were enrolled and 82 patients (mean +/- SD age, 62 +/- 15 yr; 15 women) completed the protocol. Four patients had equivocal UBT results and were excluded from the analysis. Of the 78 patients, 68 (87%) had a negative 4 to 6-wk UBT. The 2-week UBT yielded a sensitivity of 90% (95% confidence interval 72-100%), specificity of 99% (97-100%), and accuracy of 97% (93-100%). In patients with a persistently positive UBT, 14CO2 excretion at 2 wk was significantly lower than at 4-6 wk after therapy (p = 0.03). CONCLUSIONS: A UBT performed 2 wk after therapy yielded results comparable to 4 to 6 wk testing. Further studies to evaluate the optimal time of confirmatory testing in the age of more effective proton pump inhibitor-based triple therapies are warranted.     

The reliability and validity of the Adolescent Physical Activity Recall Questionnaire

PURPOSE: This study assessed the test-retest reliability and validity of the Adolescent Physical Activity Recall Questionnaire (APARQ) among 13- and 15-yr-old Australians. METHODS: Two studies were conducted using the same instrument. Self-reported participation in organized and nonorganized physical activity was summarized into four measures: a three-category measure of activity, a two-category measure, and estimated energy expenditure expressed as a continuous variable and as quintiles. The reliability study (N = 226) assessed strength of agreement for all measures between responses to two administrations of the questionnaire. The validity study (N = 2026) assessed the relationship between the APARQ and performance on the Multistage Fitness Test (MFT).RESULTS: Reliability study: for the three-category measure, percent agreement ranged 67-83% and weighted kappa ranged 0.33-0.71. For the two-category measure, percent agreement ranged 76-90% and kappa ranged 0.25-0.74. For energy expenditure expressed as a continuous variable, the intraclass correlations coefficients were generally greater than 0.6 for grade 10 students, but most were below 0.5 for grade 8 students. Validity study: for the three-category measure, mean laps were higher in the adequately and vigorously active categories than the inactive category for girls, but only the mean laps in the vigorously active and inactive categories were significantly different for boys. For the two-category measure, mean laps were higher in the active category than the inactive category for all groups. Correlations between energy expenditure and MFT laps were 0.15, 0.21, 0.14, and 0.39 for grade 8 boys, grade 8 girls, grade 10 boys, and grade 10 girls, respectively. CONCLUSION: The APARQ has acceptable to good reliability and acceptable validity, but further validation using other methods and in other population groups is required.