Citations

The angiotensin II subtype 1 receptor (AT 1 R) has been linked to the development and progression of renovascular hypertension. In this study we applied a pig model of renovascular hypertension to investigate the AT 1 R in vivo with positron-emission tomography (PET) and in vitro with quantitative autoradiography. AT 1 R PET measurements were performed with the radioligand [ 11 C]KR31173 in 11 control pigs and in 13 pigs with hemodynamically significant renal artery stenosis; 4 were treated with lisinopril for 2 weeks before PET imaging. The radioligand impulse response function was calculated by deconvolution analysis of the renal time-activity curves. Radioligand binding was quantified by the 80-minute retention of the impulse response function. Median values and interquartile ranges were used to illustrate group statistics. Radioligand retention was significantly increased ( P =0.044) in hypoperfused kidneys of untreated (0.225; range: 0.150 to 0.373) and lisinopril-treated (0.237; range:0.224 to 0.272) animals compared with controls (0.142; range:0.096 to 0.156). Increased binding of [ 11 C]KR31173 documented by PET in vivo was confirmed by in vitro autoradiography. Both in vivo and in vitro binding measurements showed that the effect of renal artery stenosis on the AT 1 R was not abolished by lisinopril treatment. These studies provide insight into kidney biology as the first in vivo/in vitro experimental evidence about AT 1 R regulation in response to reduced perfusion of the kidney. The findings support the concept of introducing AT 1 R PET as a diagnostic biomarker of renovascular disease.

Object The aim of this work was to investigate the immunohistochemical expression of nestin, a member of the intermediate filament family, in adenohypophysial vasculature during development and progression of pituitary infarction. Methods Forty-five nontumorous adenohypophyses and 34 pituitary adenomas of various types, all exhibiting acute or healing infarcts, were examined immunohistochemically using the streptavidin-biotin-peroxidase complex method. Results In both adenohypophyses and pituitary adenomas without infarction, nestin was expressed in only a few capillaries and endothelial cells. In acute infarcts without a vascular response, no nestin was demonstrable within necrotic capillaries (50 cases). In organizing infarcts, newly formed vessels spreading into necrotic zones showed nestin expression in all capillaries and practically every endothelial cell (25 cases). In the hypocellular, fibrotic scar phase, only a few vessels (4) were apparent, and immunoreactivity was focal and mild. Conclusions Nestin is strongly expressed in newly formed capillaries and is downregulated when infarcts transform to fibrous tissue. Nestin expression may provide valuable insight into the process of pituitary angiogenesis.

Abstract Purpose. Previous studies have found that marriage is associated with longer survival and better quality of life among lung cancer patients. The present study used the Mayo Clinic Lung Cancer Cohort to re-examine this issue. Methods. In total, 5,898 non-small cell lung cancer (NSCLC) patients, who had available information on marital status and who had been enrolled in the Mayo Clinic Lung Cancer Cohort (MCLCC), were the focus of this study. Patients had extensive baseline and follow-up data on cancer stage, cancer treatment, and prognostic factors. All patients had been followed within the MCLCC with at least annual confirmation of vital status and patient-reported quality of life (the Lung Cancer Symptom Scale and the Linear Analogue Scales of Assessment). Results. The numbers of patients who were married, single, divorced, and widowed at the time of cancer diagnosis were 4,457 (76%), 265 (4%), 440 (7%), and 736 (12%), respectively. No statistically significant difference in survival was observed among these four groups, even after adjusting for a variety of prognostic factors, such as age, gender, and tumor stage. However, exploratory analyses suggested that widowed and divorced patients received less aggressive cancer therapy, and certain patient subgroups, such as stage IA widowed patients, had a shorter survival. Divorced patients reported greater financial concerns, and married and widowed patients reported greater spirituality and better social support. Conclusion. This study did not observe differences in survival or quality of life based on marital status at the time of diagnosis of NSCLC, but subgroup analyses appear to suggest findings worthy of further exploration.

Abstract Context: The process of epiphyseal fusion during puberty is regulated by estrogen, even in males. Objective: Our objective was to investigate whether anastrozole, a potent aromatase inhibitor, could delay bone age acceleration and increase predicted adult height in adolescent boys with GH deficiency. Methods: Fifty-two adolescent males with GH deficiency treated with GH were randomized to cotreatment with anastrozole or placebo daily for up to 36 months. Results: Fifty subjects completed 12 months, 41 completed 24 months, and 28 completed 36 months. Linear growth was comparable between groups; however, there was a significantly slower increase in bone age advancement from baseline in the anastrozole group vs. placebo group after 2 yr (+1.8 ± 0.1 vs. +2.7 ± 0.1 yr, P < 0.0001) and after 3 yr (+2.5 ± 0.2 vs. +4.1 ± 0.1 yr, P < 0.0001). This resulted in a net increase in predicted adult height of +4.5 ± 1.2 cm in the anastrozole group at 24 months and +6.7 ± 1.4 cm at 36 months as compared with a 1-cm gain at both time points in the placebo group. Estradiol and estrone concentrations increased less in the anastrozole group compared with placebo group. All boys on the aromatase inhibitor had normal tempo of virilization. Safety data, including glucose, and plasma lipid concentrations were comparable between groups. Conclusions: Anastrozole increases adult height potential of adolescent boys on GH therapy while maintaining normal pubertal progression after 2–3 yr. This treatment offers an alternative in promoting growth in GH-deficient boys in puberty. Long-term follow up is needed to elucidate fully the safety and efficacy of this approach.

A-kinase anchoring proteins (AKAPs) recruit signaling molecules and present them to downstream targets to achieve efficient spatial and temporal control of their phosphorylation state. In the heart, sympathetic nervous system (SNS) regulation of cardiac action potential duration (APD), mediated by β-adrenergic receptor (βAR) activation, requires assembly of AKAP9 (Yotiao) with the I Ks potassium channel α subunit (KCNQ1). KCNQ1 mutations that disrupt this complex cause type 1 long-QT syndrome (LQT1), one of the potentially lethal heritable arrhythmia syndromes. Here, we report identification of ( i ) regions on Yotiao critical to its binding to KCNQ1 and ( ii ) a single putative LQTS-causing mutation (S1570L) in AKAP9 (Yotiao) localized to the KCNQ1 binding domain in 1/50 (2%) subjects with a clinically robust phenotype for LQTS but absent in 1,320 reference alleles. The inherited S1570L mutation reduces the interaction between KCNQ1 and Yotiao, reduces the cAMP-induced phosphorylation of the channel, eliminates the functional response of the I Ks channel to cAMP, and prolongs the action potential in a computational model of the ventricular cardiocyte. These reconstituted cellular consequences of the inherited S1570L-Yotiao mutation are consistent with delayed repolarization of the ventricular action potential observed in the affected siblings. Thus, we have demonstrated a link between genetic perturbations in AKAP and human disease in general and AKAP9 and LQTS in particular.

AbstractDiscriminant markers are required for accurate cancer screening. We evaluated genes frequently methylated in colorectal neoplasia to identify the most discriminant ones. Four genes specifically methylated in colorectal cancer [bone morphogenetic protein 3 (BMP3), EYA2, aristaless-like homeobox-4 (ALX4), and vimentin] were selected from 41 candidate genes and evaluated on 74 cancers, 62 adenomas, and 70 normal epithelia. Methylation status was analyzed qualitatively and quantitatively and confirmed by bisulfite genomic sequencing. Effect of methylation on gene expression was evaluated in five colon cancer cell lines. K-ras and BRAF mutations were detected by sequencing. Methylation of BMP3, EYA2, ALX4, or vimentin was detected respectively in 66%, 66%, 68%, and 72% of cancers; 74%, 48%, 89%, and 84% of adenomas; and 7%, 5%, 11%, and 11% of normal epithelia (P < 0.01, cancer or adenoma versus normal). Based on area under the curve analyses, discrimination was not significantly improved by combining markers. Comethylation was frequent (two genes or more in 72% of cancers and 84% of adenomas), associated with proximal neoplasm site (P < 0.001), and linked with both BRAF and K-ras mutations (P < 0.01). Cell line experiments supported silencing of expression by methylation in all four study genes. This study shows BMP3, EYA2, ALX4, and vimentin genes are methylated in most colorectal neoplasms but rarely in normal epithelia. Comethylation of these genes is common, and pursuit of complementary markers for methylation-negative neoplasms is a rational strategy to optimize screening sensitivity. (Cancer Epidemiol Biomarkers Prev 2007;16(12):2686–96)

Abstract Background Management of patients with bilateral adrenal masses and corticotropin (ACTH)‐independent Cushing syndrome (CS) or subclinical CS is problematic. We report our experience with adrenal venous sampling (AVS) in the evaluation of 10 patients with bilateral masses who had ACTH‐independent CS or subclinical CS. Patients and Methods Ten patients (9 women, 1 man, mean age 56.4 years) with bilateral adrenal masses and ACTH‐independent CS ( n = 3) or subclinical CS ( n = 7) underwent AVS. Autonomous cortisol secretion was documented in all cases with suppressed serum ACTH concentrations and lack of cortisol suppression with dexamethasone administration. Adrenal venous sampling was performed on the second day of dexamethasone administration. Cortisol and epinephrine levels were measured from each adrenal vein (AV) and from a peripheral vein (PV). Results Mean (± SD) maximal diameter of the adrenal masses on computed tomography was 3.3 ± 1.3 cm (range: 1.2–6.0 cm). Successful catheterization was confirmed with AV:PV epinephrine gradients. A cortisol AV:PV gradient >6.5 was consistent with a cortisol‐secreting adenoma in 11 adrenal glands; 5 patients had clinically important bilateral autonomous cortisol hypersecretion, 3 had bilateral cortisol‐secreting adenomas, and 2 had ACTH‐independent macronodular adrenal hyperplasia. Adrenal venous sampling‐guided adrenalectomy was completed in all 10 patients—2 patients had total bilateral adrenalectomy and 2 others had subtotal bilateral adrenalectomy. During a mean follow‐up of 36.1 months (range: 0.7–123 months), CS or clinically important cortisol secretory autonomy did not recur. Conclusions Adrenal venous sampling contributed to the localization of autonomous hypercortisolism in the setting of ACTH‐independent CS or subclinical CS in patients with bilateral adrenal masses.