Progression of macrovascular disease after transplantation

INTRODUCTION: Cardiovascular and cerebrovascular disease are major causes of morbidity and mortality after kidney transplantation. The aim of this longitudinal study was to examine the natural history of carotid plaque and to determine risk factors for the progression of vascular disease in uremic, type 1 diabetic patients who received a combined kidney and pancreas transplant. METHODS: Carotid artery (n=765) and lower limb vascular duplex scanning (n=656) were prospectively undertaken in 82 recipients before transplantation, at 6 months, and then at annual intervals for up to 10 years. Plaque in the internal carotid artery (ICA), external carotid artery, and common carotid artery was classified by type, location, extent, and degree of functional obstruction, and evaluated using multivariate analysis. RESULTS: Carotid plaque was present in 22.5% of patients at initial scanning, but increased to 56.6% by 7-10 years after transplantation, especially in the ICA and common carotid artery. Both the severity and extent of plaque increased, and plaque became more complex and heterogeneous with time after transplantation (P<0.001). Carotid plaque was associated with older age, current cigarette smoking, hyperphosphatemia, hypoalbuminemia, duration of pretransplantation dialysis, and presence of lower limb plaque (P<0.05-0.001). The severity of carotid plaque increased in older, hypertensive recipients and was associated with metabolic acidosis and hyperphosphatemia (all P<0.05). Severity of ICA disease correlated with disease in the contralateral ICA (r=0.57, P<0.001) and femoral arteries (r=0.42, P<0.001). Paradoxically, each carotid artery progressed independently of the other. ICA disease severity progressed when heterogenous, calcified, or new plaque was present on scanning, and with reduced renal transplant function (P<0.01-0.001). The mean ICA blood flow remained stable with time but was progressively impaired by hypertension, fasting hyperglycemia, and a lower prednisolone dose (P<0.05). Cerebrovascular events occurred in only four patients and were unrelated to carotid disease, implying relative plaque stability. CONCLUSION: Extensive carotid vascular wall abnormalities increased significantly despite kidney and pancreas transplantation. Initiation of plaque was associated with systemic factors, whereas progression of established plaque was largely influenced by local factors within the arterial wall.     

Coexistent gallbladder carcinoma in Mirizzi syndrome

A 52‐year‐old woman presented with right upper quadrant pain and obstructive jaundice. Computed tomographic scan showed Mirizzi syndrome type 1 and a thickened and calcified gallbladder wall, raising the possibility of coexistent gallbladder carcinoma that was later confirmed on histology post‐cholecystectomy.     

A new recommendation for maternal weight gain in Chinese women

OBJECTIVE: To characterize the distribution of maternal weight gain in Chinese women living in a well-nourished community, to recommend target weight gains from quartile values derived from women with good pregnancy outcomes, and to quantify the risk for adverse pregnancy outcomes encountered among subjects with weight gain outside these recommendations. DESIGN: A retrospective study on maternal anthropometry and pregnancy outcomes was conducted among Chinese women who delivered a singleton pregnancy in a university hospital in Hong Kong. SUBJECTS: Nine hundred eight women who delivered during the study period were identified. Among them, 754 (83%) had complete anthropometry data. The normative distribution of maternal weight gain was derived from 504 women who had a good pregnancy outcome. STATISTICS: Analysis of variance was used to compare total weight gain among women of different prepregnancy weight. Fisher exact test was used in the univariate analysis of the association between risk factors and corresponding adverse pregnancy outcomes. Adjusted odds ratios for adverse outcomes were determined by multiple logistic regression models controlling for the following factors: maternal age, duration of gestation, prepregnancy body mass index (BMI), height, parity, and smoking. RESULTS: A maternal weight-gain chart and recommendations for total weight gains in Chinese women were derived from the distribution of weight gain in subjects with good pregnancy outcomes. The recommended total weight gain was 13 to 16.7 kg, 11 to 16.4 kg, and 7.1 to 14.4 kg respectively for women of low (BMI < 19), moderate (BMI: 19 to 23.5), and high (BMI > 23.5) prepregnancy BMI. Women who did not achieve the lower quartile value had more than twice the risk of having low-birth-weight infants. Those with excessive weight gain were at risk for needing assisted delivery. APPLICATIONS: As maternal anthropometry differs across ethnic groups, different recommendations should be made for specific populations.     

Imaging of non-small-cell lung cancer with indium-111 pentetreotide

PURPOSE: Lung cancer is the leading cause of cancer deaths in the United States. Non-small-cell lung cancer (NSCLC) accounts for 75% to 85% of lung cancers. CT has been the standard anatomic study for localizing and staging NSCLC, although it is associated only with moderate accuracy. In-111 pentetreotide, a radiolabeled somatostatin analog largely used in the scintigraphic localization of neuroendocrine tumors, has been shown incidentally to identify NSCLC lesions. This observation is important in the workup for metastatic disease for neuroendocrine tumors, because presumed metastatic lesions may actually be second primary tumors of NSCLC. In-111 may also serve as a potentially useful adjunct to CT in the anatomic evaluation of NSCLC. The purpose of this study was to determine the likelihood of detecting and localizing NSCLC using In-111 pentetreotide scintigraphy. MATERIALS AND METHODS: Ten patients with known or possible NSCLC were examined using In-111 pentetreotide. Scans were compared with the patients' previously performed chest radiographs and CT scans. RESULTS: In-111 pentetreotide imaging correctly identified sites of tumor involvement as detected by chest CT and surgery in all 10 patients with NSCLC. CONCLUSION: This study demonstrates the uptake of In-111 pentetreotide by NSCLC. This important observation should be considered in the workup for metastatic disease of neuroendocrine tumors with In-111 pentetreotide, because NSCLC can be a source of false-positive findings. In-111 pentetreotide imaging may also serve as a potentially useful adjunct to CT for identifying obscured or equivocal lesions and as an aid in localizing tissue for biopsy.     

Improved efficiency for MRI-SPET registration based on mutual information

Mutual information has been proposed as a criterion for image registration. The criterion is calculated from a two-dimensional grey-scale histogram of the image pair being registered. In this paper we study how sparse sampling can be used to increase speed performance using the registration algorithm of Maes et al. (IEEE Trans Med Imaging 1997; 16: 187-198) with a focus on registration of MRI-SPET brain images. In particular we investigate how sparse sampling and parameters such as the number of bins used for the grey-scale histograms and smoothing of the data prior to registration affect accuracy and robustness of the registration. The method was validated using both simulated and human data. Our results show that sparse sampling introduced local maxima into the mutual information similarity function when the number of bins used for the histograms was large. To speed up registration while retaining robustness, smoothing of the data prior to registration was used and a coarse to fine subsampling protocol, where the number of bins in the histograms were dependent on the subsampling factor, was employed, For the simulated data, the method was able to recover known transformations with an accuracy of about 1 mm. Using the human data, there were no significant differences in the recovered transformation parameters when the suggested subsampling scheme was used compared with when no subsampling was used, but there was a more than tenfold increase in speed. Our results show that, with the appropriate choice of parameters, the method can accurately register MRI-SPET brain images even when very efficient sampling protocols are used.     

Distribution of PDE4A and G(o) alpha immunoreactivity in the accessory olfactory system of the mouse

Distribution of the cAMP-specific phosphodiesterase PDE4A was examined in the accessory olfactory system by immunohistochemistry. Adjacent sections through the vomeronasal organ (VNO) and accessory olfactory bulb (AOB) were alternately immunostained with antibodies against PDE4A or the G-protein alpha subunit G(o) alpha, which labels basal VNO neurons, in order to determine whether PDE4A occurs preferentially in one of two segregated VNO pathways. We found that PDE4A strongly labeled apical VNO neurons and rostral AOB glomeruli. There was virtually no overlap in G(o) alpha and PDE4A staining, and there were no regions of the VNO neuroepithelium or AOB glomeruli not labeled by either antibody. These results identify a potential member of the pheromone transduction cascade in apical neurons, and provide further evidence that the VNO consists of functionally distinct pathways.