Biomedical subjects

George Holland

Publications and source records attributed to George Holland.

5 recordsLinked to original sources

PubMed2002

Ovarian veins: magnetic resonance imaging findings in an asymptomatic population.

PURPOSE: To evaluate the magnetic resonance (MR) venographic appearance of the ovarian veins in a healthy population, correlated with surgical findings. Our data can be used as a basis for comparison to patients with suspected pelvic congestion syndrome (PCS). MATERIALS AND METHODS: We retrospectively reviewed exams of 22 women who had MR angiography for potential renal donation evaluation (age range, 19.3-60.5 years; mean, 38 years). We evaluated the diameter of the ovarian veins on dynamic multiphasic postcontrast coronal images, the phase of contrast appearance in these veins, the apparent direction of flow, and the presence of ovarian or pelvic varices. Surgical correlation was obtained in 12 patients. Clinical charts were reviewed and patients were asked about symptoms of chronic pelvic pain and the number of their children. RESULTS: Of the 22 exams, 21 left gonadal veins were identified. Passive reflux from the left renal vein into the left gonadal vein was suggested in eight exams (38%). These veins had a mean diameter of 6.4 +/- 1.6 mm, significantly larger than 4.5 +/- 1.3 mm for the other 13 left gonadal veins without reflux (P < 0.005). The right gonadal vein was identified in 8 of 22 women, with a mean diameter of 4.4 +/- 0.5 mm. No patient reported symptoms of chronic pelvic pain. CONCLUSION: Passive reflux from the left renal vein to the left gonadal vein can occur in asymptomatic women. Diagnosis of PCS depends heavily on appropriate clinical history.

Adult↗

PubMed2002

Normal adrenal gland: in vivo observations, and high-resolution in vitro chemical shift MR imaging-histologic correlation.

RATIONALE AND OBJECTIVES: The purpose of this study was to determine whether adrenal cortical lipid affects signal intensity on magnetic resonance (MR) images and to evaluate contrast between cortex and medulla. MATERIALS AND METHODS: From their clinical database, the authors selected 37 MR imaging studies of patients with adrenal adenomas. Two independent readers compared in-phase and fat-suppressed T1-weighted images, looking for visible lipid-induced signal intensity loss in the adrenal gland. Six adrenal gland specimens obtained after radical nephrectomy were also studied with high-resolution MR imaging, including in-phase, opposed-phase, and fat-suppressed T1-weighted images, and T2-weighted images. Adjacent histologic sections were stained with oil red O for neutral fats and with hematoxylin-eosin, and they were also viewed with polarization light microscopy. The relative amount of lipid was graded as mild, moderate, or intense, and the appearance of the cortex and medulla was compared with that on the MR images. RESULTS: On the 37 clinical MR studies, there was no visible signal intensity loss within the limbs of the ipsilateral adrenal glands. T2-weighted images of the adrenal specimens showed a thin high-intensity band, corresponding to the appearance of medulla on histologic slices. This could not be seen on any of the T1-weighted images. Region-of-interest measurements were nearly identical for in-phase and opposed-phase images. Histologic analysis showed abundant cortical lipid. CONCLUSION: Adrenal corticomedullary contrast can be depicted on high-resolution T2-weighted images but not on any T1-weighted images. There is abundant cortical lipid in adrenal specimens, but comparison of in-phase with opposed-phase MR images does not depict it.

Adrenal Cortex Neoplasms↗

PubMed2002

Atypical polypoid adenomyoma mimicking cervical adenocarcinoma.

Atypical polypoid adenomyoma (APA) of the uterus is a rare, benign lesion. Histologically, it is composed of a glandular and squamous cell proliferation with architectural complexity and cytologic atypia of glands, and a hypercellular smooth muscle stroma. APA is difficult to distinguish from well-differentiated adenocarcinoma of the uterus. In the case presented, the diagnosis of APA was confused pathologically, radiographically, and clinically with a cervical adenocarcinoma. A review of the English literature is presented.

Journal Article↗

PubMed2002

Cirrhosis: modified caudate-right lobe ratio.

PURPOSE: To determine whether a modified caudate-right lobe ratio (C/RL) with use of the right portal vein to set the lateral boundary (C/RL-r) is more accurate for diagnosing cirrhosis and evaluating its clinical severity than is the previously described C/RL with use of the main portal vein to set the lateral boundary (C/RL-m). MATERIALS AND METHODS: Two hundred thirty-six patients (121 with pathologically proved cirrhosis and 115 without history of chronic hepatic diseases) underwent magnetic resonance (MR) imaging. Two independent observers measured C/RL-r and compared it with C/RL-m. Results were compared by using receiver operating characteristic (ROC) curves and accuracy measures at various thresholds. RESULTS: The area below the ROC curve was greater for C/RL-r (0.797) than for C/RL-m (0.731; P =.040). By using a C/RL-r greater than 0.90, the sensitivity, specificity, and accuracy for the MR imaging diagnosis of cirrhosis were 71.7%, 77.4%, and 74.2%, respectively. The highest accuracy of the C/RL-m was 65.7%, when the C/RL-m was greater than 0.55. Interobserver agreement was statistically confirmed for both measurements by using kappa analysis. Significant differences were found among the three Child-Pugh classes by using C/RL-r (P =.0105) but not by using C/RL-m. CONCLUSION: C/RL-r is more accurate for diagnosing cirrhosis and evaluating its clinical severity than is C/RL-m.

Adult↗

PubMedDate not supplied

Genetic algorithm-optimized QSPR models for bioavailability, protein binding, and urinary excretion.

In this work, a genetic algorithm (GA) was applied to build up a set of QSPR (quantitative structure-property relationship) models for human absolute oral bioavailability, plasma protein binding, and urinary excretion using the counts of molecular fragments as descriptors. For a pharmacokinetic property, the consensus score of a set of models (20 or 30) was found to improve the correlation coefficient and reduce the standard error significantly. Key fragments that may boost or reduce pharmacokinetic properties were also identified. Databases searches were performed for a set of key fragments identified by bioavailability models. The percentage of hit rates of bioavailability-boosting fragments were significantly higher than those of bioavailability-reducing fragments for MDDR (MDL Drug Data Report), a database of drugs and drug leads entered or entering development. On the other hand, the opposite trend was observed for ACD (Available Chemicals Directory), a database of all kinds of available compounds.

Administration, Oral↗