Three-dimensional flow-independent peripheral angiography

A magnetization-prepared sequence, T₂-Prep-IR, exploits T₁, T₂, and chemical shift differences to suppress background tissues relative to arterial blood. The resulting flow-independent angiograms depict vessels with any orientation and flow velocity. No extrinsic contrast agent is required. Muscle is the dciminant source of background signal in normal volunteers. However, long-T₂ deep venous blood and nonvascular fluids such as edema also contribute background signal in some patients. Three sets of imaging parameters are described to address patient-specific contrast requirements. A rapid, spiral-based, three-dimensional readout is utilized to generate high-resolution angiograms of the lower extremities. Comparisons with x-ray angiography and two-dimensional time-of-flight angiography indicate that this flow-independent technique has unique capabilities to accurately depict stenoses and to visualize slow flow and in-plane vessels.     

Perinephritis hypertension in Macaca fascicularis (cynomolgus monkey): studies of the renin-angiotensin-aldosterone axis and renal hemodynamic function

The purpose of the present study was to characterize the etiology of bilateral perinephritis hypertension in the non-human primate. Hypertension was induced in female cynomolgus (Macaca fascicularis) monkeys by wrapping both kidneys under sterile surgical procedures. Mean arterial pressure (MAP), plasma renin activity (PRA), plasma aldosterone concentration (ALDO), para-aminohippurate (PAH) clearance, glomerular filtration rate (GFR), urine volume, and sodium and potassium excretion were measured before and weekly after induction of the hypertension. MAP increased progressively from 108 +/- 1 to 135 +/- 4 mmHg during the first 6 weeks; thereafter, MAP remained at this elevated level, PRA was elevated two- to fivefold for up to 10 weeks after the hypertension and ALDO was elevated during 1 (139%), 4 (60%), 6 (196%), 8 (249%) and 10 (148%) weeks of the hypertension. PAH clearance and GFR were significantly reduced during week 1 of the hypertension, but returned to control values by week 2. Urine volume was increased significantly during the first week of the hypertension, while sodium and potassium excretion were not changed. Captopril (15 mumol/kg, intravenously) normalized the blood pressure regardless of the severity or duration of the disease. Additionally, captopril lowered ALDO and increased PRA. It is concluded that bilateral perinephritis hypertension in the monkey is dependent on increased activity of the renin-angiotensin-aldosterone axis.     

Structure-activity profile of substituted purines and inflammation in the delayed hypersensitivity skin reaction.

Substituted purines were tested for their effectiveness in inhibiting the delayed hypersensitivity skin reaction (DHSR) caused by tuberculin in the guinea-pig. Among the tested purines were naturally occurring derivatives of guanine and adenine, including cyclic AMP. Based on the structure-activity profile, a class of purines was identified, the members of which were very effective inhibitors of inflammatory aspects of the DHSR and are characterized by a benzyl group in position 9, an amino or alkylamino group in position 6, and various substituents in position 2. This class of 2-substituted-9-benzyladenines was more effective in the DHSR than some antimetabolites, particularly the structurally related mercaptopurines.     

Some observations on the β-adrenoceptor agonist properties of the isomers of salbutamol

1. The pharmacological activities of the optical isomers of salbutamol have been examined. (-)-Salbutamol was much more potent than (+)-salbutamol on β-adrenoceptors.

2. Both (-)- and (+)-salbutamol showed high selectivity for β-adrenoceptors in bronchial muscle compared to cardiac muscle, in this way resembling racemic salbutamol.

3. The use of isomeric activity ratio to detect differences between receptors was examined in the light of the results obtained with the isomers of salbutamol.

     

Assay of suxamethonium and laudexium on the frog rectus abdominis

Suxamethonium, like acetylcholine, causes contracture of the isolated rectus abdominis muscle of the frog, whereas laudexium antagonizes this effect. These actions may be used to assay both drugs with reasonable speed and fiducial limits, provided that changes in responsiveness of the preparation during the course of assay are met by suitable design and analysis. Small quantities of suxamethonium and laudexium may be assayed in certain body fluids.     

Interleaved variable density sampling with a constrained parallel imaging reconstruction for dynamic contrast‐enhanced MR angiography

For MR applications such as contrast‐enhanced MR angiography, it is desirable to achieve simultaneously high spatial and temporal resolution. The current clinical standard uses view‐sharing methods combined with parallel imaging; however, this approach still provides limited spatial and temporal resolution. To improve on the clinical standard, we present an interleaved variable density (IVD) sampling method that pseudorandomly undersamples each individual frame of a 3D Cartesian k_y–k_z plane combined with parallel imaging acceleration. From this dataset, time‐resolved images are reconstructed with a method that combines parallel imaging with a multiplicative constraint. Total acceleration factors on the order of 20 are achieved for contrast‐enhanced MR angiography of the lower extremities, and improvements in temporal fidelity of the depiction of the contrast bolus passage are demonstrated relative to the clinical standard. Magn Reson Med, 2011. © 2011 Wiley‐Liss, Inc.     

Interrelationship between TP53 gene deletion, protein expression and chromosome 17 aneusomy in gastric adenocarcinoma

Background  

This study evaluates the existence of numerical alterations of chromosome 17 and TP53 gene deletion in gastric adenocarcinoma. The p53 protein expression was also evaluated, as well as, possible associations with clinicopathological characteristics.