Dissolution of tetracycline hydrochloride in mucin solutions.
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Animals↗
Biomedical subjects
P Kearney
Publications and source records attributed to P Kearney.
Soft drugs. 3. A new class of anticholinergic agents.
A new class of antimuscarinic drugs was designed and synthesized. The compounds are "soft" quaternary ammonium esters in which there is only one carbon atom separating the ester oxygen and the quaternary head. The compounds are potent anticholinergics when derived from hindered "umbrella" acids and cholinergics when derivatives of simple aliphatic acids. The more potent anticholinergics have up to 10 times higher acetylcholine antagonist activity than atropine, but they have a much shorter duration of action. The compounds cleave hydrolytically with simultaneous destruction of the quaternary head. The compounds are promising as selective, local agents, particularly as inhibitors of eccrine sweating.
Acetylcholine↗
Cystic adventitial degeneration of the common femoral artery.
Cystic adventitial degeneration (CAD) of the arteries is an uncommon cause of intermittent claudication in adults. The majority of reported cases have involved the popliteal artery and have occurred predominantly in men, and all had clinical evidence of occlusive vascular disease. An unusual example of CAD of the common femoral artery masqueraded clinically as an aneurysm, but the arteriogram was normal. It involved 5 cm of the artery and half its circumference, and was resected and replaced with a saphenous vein graft. The cyst contained clear mucoid fluid and a fibrous wall without a cyst lining. This is the eighth case reported of CAD involving the proximal segment of a large lower extremity artery. The etiology is unknown, but many authors think such cysts arise from primitive "arthrogenic" mesenchyme in the adventitia of blood vessels.
Cysts↗
Three-dimensional imaging of cardiac mass lesions by transesophageal echocardiographic computed tomography.
Three-dimensional echocardiography is a new imaging technique that allows more realistic visualization of cardiac morphology. This study presents data about the diagnostic potentials of this technique concerning cardiac mass lesions, as well as its feasibility in clinical application. After the conventional investigation, multiple cross-sectional images were obtained during automatic forward advancement of a monoplane transducer mounted on a transesophageal probe. Three-dimensional reconstruction and volume determination were performed off line. Twenty-four patients were studied. In 14 cases results of echocardiographic computed tomography (echo-CT) were compared with those of monoplane/biplane transesophageal echocardiography. In 23 patients a conventional transesophageal investigation with the echo-CT probe and in 20 patients tomographic scanning were possible. Data acquisition required 12 +/- 4 minutes and three-dimensional reconstruction required 35 +/- 14 minutes. In 13 patients mass lesions were found; in 11 of 13 patients echo-CT provided diagnostic information about the precise spatial orientation and morphology of cardiac structures that could not be obtained by monoplane/biplane transesophageal echocardiography. The technique revealed accurate distance measurements and volume determination of mass lesions. Echo-CT is a further step toward the application of clinically useful three-dimensional echocardiography.
Echocardiography, Transesophageal↗
Effects of L-arginine on the proliferation of T lymphocyte subpopulations.
BACKGROUND: Dietary supplementation of L-arginine as a mechanism to enhance cellular immune response (T lymphocytes), has slowly gained approval, and appears especially important during critical illness. Despite its clinical use, little is known as to the direct effects of L-arginine on the different T lymphocyte subpopulations. METHODS: Lymphocytes were harvested from spleens of C57 B1/6 mice, and proliferation was induced with anti-CD3 in the presence of different concentrations of L-arginine ranging from 0 to 1000 micromol/L. Flow cytometry was used to evaluate the effect of L-arginine on T lymphocyte subpopulations. Interleukin-2 production was measured by ELISA and gene expression by RT-PCR. RESULTS: L-Arginine at or greater than 100 micromol/L significantly enhanced anti-CD3 stimulated T lymphocyte proliferation (p = .01). L-Arginine was essential for adequate T lymphocyte (CD3+) cellular maturation (p = .01). Proliferation of Helper T cells (CD4+) was not dependent on L-arginine. In contrast, Cytotoxic T cells (CD8+) showed a dose dependent proliferation in response to L-arginine (p = .01). Of the CD8+ cells, an increase in the CD45RA negative CD8 positive (memory) T cell subpopulation was observed with the addition of L-arginine. In addition, the number of cell surface CD8 receptors (CD8R) and CD3 receptors (CD3R) increased in the presence of L-arginine (p = .01, p = .04). Interleukin-2 receptor (IL-2R) expression was not up-regulated by L-arginine. L-Arginine modestly increased IL-2 production and had pronounced effects on its disappearance from the culture media (p < .0001). Interleukin-2 mRNA expression was not dependent on L-arginine. CONCLUSIONS: The requirements for L-arginine for the proliferation of CD3 stimulated T lymphocytes vary widely, and have to be taken into account when studying the mechanism of how L-arginine enhances cellular proliferation. L-Arginine may increase cellular proliferation by increasing specific receptor expression and the utilization of interleukin-2.
Animals↗