A comparative study of the electrophysiologic effects of Striadyne, adenosine triphosphate and adenosine in the canine heart

The chronotropic and dromotropic effects of the intra-atrial administration of 0.97, 1.93 and 2.90 microM/kg Striadyne, the pharmaceutical form of adenosine triphosphate (ATP) for clinical use, ATP, and adenosine, were compared in 13 anesthetized dogs. Striadyne, ATP and adenosine exerted transient dose-dependent negative chronotropic and dromotropic effects. There was no significant difference between the electrophysiologic effects of Striadyne and ATP which were significantly more pronounced than those of adenosine. Atropine (0.2 mg/kg) significantly attenuated the electrophysiologic effects of 2.90 microM/kg Stridyne and ATP but not those of adenosine. It is concluded that Striadyne and ATP have similar electrophysiologic effects which are more pronounced than those of adenosine mainly due to vagal involvement in their mechanism of action.

Myxoid chondrosarcoma of the os calcis: a case report

This case report of a myxoid chondrosarcoma of the os calcis is presented because of its rarity. The clinical, roentgenographic, and pathological features are discussed, and the difficulty in diagnosis is elaborated.

Radial head-capitellum view in elbow trauma: clinical application and radiographic-anatomic correlation

The radial head-capitellum view, first reported 2 years ago, has proved useful in the evaluation of elbow trauma. Minimally displaced or nondisplaced fractures of the radial head, capitellum, and coronoid process are better demonstrated on this special projection than on traditional radiographs of the elbow. To test the accuracy of this view, 50 patients with trauma to the elbow were examined and routine anteroposterior, lateral, and external oblique radiographs were compared with this special angled projection. In 10 patients, the conventional studies either were negative or failed to show the full extent of the fracture, whereas the radial head-capitellum view demonstrated the abnormality in every case. A human cadaver elbow specimen was used in a radiographic anatomic correlative study to further confirm the usefulness of this technique. It revealed that fractures of the posterior half of the radial head were particularly difficult to diagnose on the traditional lateral view. The radial head-capitellum view not only distinctly delineated these fractures, it showed the full extent of their articular displacement. The authors recommend the use of this technique in all cases of chronic and acute trauma to the elbow joint.

The "pelvic digit"--an unusual developmental anomaly

Five cases of a rare developmental anomaly involving extraskeletal bone formation are described--four in the pelvis and one arising from the 12th rib. Three of these bony growths, called "Pelvic digits" had well developed "joints" or pseudoarticulations. The similarity of this anomaly to posttraumatic myositis ossificans and avulsion injuries of the pelvis (rectus femoris) is pointed out and a differential diagnosis offered.

Replacement of ventricular myocardium with diaphragmatic skeletal muscle: short-term studies

A pedicled diaphragmatic skeletal muscle graft was used to replace a portion of resected right ventricle in 35 dogs. The graft contracted when electrically stimulated directly or via the phrenic nerve before and after insertion. The electrical pacing threshold was lower for phrenic nerve stimulation (0.9 +/- 0.20 mamp) than for direct graft stimulation (2.3 +/- 1.19 mamp). The heart could be captured and paced by stimulating the muscle graft with higher current (16.2 +/- 4.49 mamp). The delay from pacing stimulus to muscle graft contraction when the graft was paced directly was 10 msec. The epicardial activation time delay when the heart was paced through the muscle graft was 27.0 +/- 9.08 msec. When the muscle graft pedicle was transected, the graft lost its ability to contract. The heart, however, could still be captured electrically through the graft for up to 4 hours. Strain gauge studies of the nonstimulated muscle graft showed tension development during pre-ejection ventricular contraction identical to that of the right ventricle. In the ejection phase, muscle graft tension slowly declined. The stimulated muscle graft developed active tension and echographically demonstrated muscle thickening during contraction. This study demonstrates that a vascularized, neurally innervated diaphragmatic muscle graft can be placed into the right ventricle. The graft retains its ability to contract in response to direct or phrenic nerve stimulation. It can be made to contract during any phase of the cardiac cycle. Thus diaphragmatic muscle grafts may provide a method to augment ventricular cavity size with synchronously contracting muscle.

Scoliotic index: a comparative evaluation of methods for the measurement of scoliosis

A new technique of measurement--Scoliotic Index(SI)--was devised to obtain more accurate determination of the spinal curvature. In comparison with previously established methods (Ferguson, Cobb), the SI is a more comprehensive and accurate representation of the scoliotic curve. It measures that the deviation of each involved vertebral segment from the vertical spinal lines with multiple points taken along the scoliotic curve. The development of this technique proved by serendipity that the Ferguson and Cobb measurements of the angle of scoliosis are reliable and comparable at all degrees of curvature.

Gross hematuria: a complication of intrapelvic cement intrusion in total hip replacement

Four patients with gross hematuria and dysuria following intrusion of methylmethacrylate into the pelvic cavity after total hip replacement are described. This is a rare, benign complication which generally occurs 7-14 days after surgery and subsides promptly with symptomatic treatment. The diagnosis can be made on a simple radiography of the pelvis which shows the radiopaque cement as a mass intruding with the pelvic cavity. On the urogram it frequently abuts against or produces an extrinsic impression on the urinary bladder. This complication is very likely a result of the exothermal reaction during polymerization of the methylmethacrylate.

"Tooth" sign in patellar degenerative disease

In the total examination of the knee, degenerative changes and ossification in the quadriceps tendon easily recognized on the lateral roentgenogram may cause confusion in diagnosis when seen on the axial view. Vertical ridging of the osteophytes at the patellar insertion of the quadriceps tendon can resemble dentate structure ("tooth" sign). Two hundred and fifty examinations of the knee in different age groups were reviewed and several anatomical sections of the quadriceps-patella insertion were studied. The "tooth" sign represents the relief of severe osteophyte formation in the bundle of the quadriceps tendon at its insertion into the patella.

Precocious onset of Paget's disease--a report of three cases and review of the literature

Paget's disease generally has its onset in mid-adult life, however cases are known to occur in young adults, albeit rare. Three patients with precocious onset of Paget's disease are reported and the literature is reviewed. The classical radiographic appearance of Paget's disease of bone is described.

Separation of 5'-mono-, di- and triphosphates of 1-beta-D-arabinofuranosylcytosine and of 1-beta-D-arabinofuranosyluracil by thin-layer and high pressure liquid chromatography

The separation of all the 5'-mono-, di- and triphosphates of ara-C and ara-U by thin-layer (TLC) and high pressure liquid chromatography (HPLC) is described. Whereas for the TLC two different systems are necessary, HPLC allows a rapid separation of all the nucleotides with high resolution, reproducibility, and sensitivity within 15 minutes. An example of an HPLC separation of ara-C and ara-U nucleotides derived from a biological sample is presented.