Axonal transport of tritium-labeled putrescinein the embryonic visual system of zebrafish.

The transport of [(3)H]putrescine is demonstrated by autoradiography in the retino-tectal tract of Brachydanio rerio embryos. Transport of [(3)H]putrescine appears to be more rapid than that of tritium-labeled protein and is not inhibited by a colchicine effect on axonal neurotubules as is protein transport. The radioactivity transported to the brain is found, on electrophoresis, in the putrescine fraction.

High resolution scintiautoradiography.

An electron microscopic scintiautoradiographic method for studying histological sections is reported. An increase in the silver grain yield is attained by using a scintillator in embedding medium. The amplification effect for 3H-labeling reaches 3-fold and for 14C reaches a 15-fold. No lessening of autoradiographic resolution was observed. On the basis of these preliminary results only qualitative evaluation of data is discussed.

Adjunctive therapies in the cath lab. Combination of tirofiban and alteplase in acute myocardial infarction.

Primary angioplasty results in higher reperfusion rates than fibrinolysis in patients with acute myocardial infarction (MI). Two recent trials have shown improved rates of reperfusion when a reduced-dose thrombolytic is combined with the platelet glycoprotein IIb/IIIa receptor inhibitor abciximab. We present a case report of acute MI successfully treated with a combination of tirofiban and half-dose alteplase and eventual percutaneous coronary intervention.

Uptake of tritium labelled chloroquine into organized cultures of rat spinal ganglia. An electron microscope autoradiographic study.

Cultured spinal ganglia of the rat treated with 3-3H-chloroquine led to the formation of numerous multilamellated bodies (MLB) in the perikarya of neurons, satellite cells, and fibroblasts. Electron microscope autoradiography showed label over and near a considerable proportion of MLB. The action of chloroquine in MLB is discussed with regard to its effect upon lysosomes.

Potential artifact in measurement of left ventricular filling pressure with flow-directed catheters.

Artifactual pulmonary wedge pressure measurements were encountered during bedside use of Swan-Ganz catheters. These values were higher than pulmonary artery end diastolic pressure and devoid of typical phasic contours. Utilizing fluoroscopy these artifacts were reproduced by advancing the catheter tip 2-4 cm beyond the site of initial wedging and reinflating the balloon. Spurious increases of pulmonary wedge pressure of up to 15 mm Hg were thus obtained. In vitro catheter testing demonstrated overlapping of the catheter tip by the deformed balloon when it was fully inflated in a channel too small to accomodate it. These measurement artifacts are thus attributed to distal migration of the catheter tip into relatively small pulmonary artery branches and to subsequent occlusion of the catheter lumen by the balloon when it is reinflated. This can readily be avoided by routinely inflating the balloon with the minimum volume of air sufficient to yield a pulmonary wedge pressure tracing.

Appraisal of sinus node artery disease.

The relationship of depressed sinus node function to coronary artery disease (CAD) was evaluated. The sinus node artery (SNA) was easily identified in all of 80 unselected normal coronary arteriograms. Angiographic disease of, or significant obstruction proximal to, the SNA was seen in 21% of 80 unselected CAD patients. Heart rate and sinoatrial recovery times (SART) were obtained in 50 consecutive unmedicated patients prior to arteriography. There was no difference between the SART of 23 CAD patients free of SNA involvement (1092 msec +/- 55 sem) and 18 normals (1070 +/- 40 msec). Nine patients with SNA involvement had shorter SART (941 +/- 52 MSEC) than normals (P less than 0.05) or other CAD patients (NS). Similar results were obtained for heart rate. No patient with SNA involvement had a prolonged SART or sick sinus syndrom (SSS). six of the 50 patients studied were symptomatic with SSS. Five of these SSS patients had CAD but none had angiographic evidence of SNA involvement. Obstructions involving the SNA were common in CAD but were not associated with altered heart rate or SART. Patients with SSS exhibited no angiographic evidence of SNA involvement. Therefore, it is unlikely that SSS is related to CAD of the SNA.