Quantitation of myocardial infarct size from thallium-201 images: validation of a new approach in an experimental model

A new computer-based method has been developed to quantitate myocardial infarct size from the size of the regional thallium-201 deficit. The operator outlines the left ventricular myocardial activity with an ellipse. The program then plots the background-corrected activities of the highest mean value in a 3 pixel myocardial band perpendicular to and within the ellipse. The approach uses a new interpolative background correction. To determine the accuracy of this approach in assessing regional thallium deficit size, acute myocardial infarction was produced in six dogs by 24 hour occlusion of the proximal left anterior descending coronary artery. Infarct size was assessed from planar thallium images of the dog heart in three views, each with the chest opened and closed and with the heart excised and placed in a cradle. Before removal of the heart, triphenyltetrazolium chloride was infused to delineate normal from infarct tissue. Transverse slices of left ventricle were made and thallium images of the slices acquired. Infarct size delineated by triphenyltetrazolium chloride staining was expressed as a percent of the total left ventricular slice surface area (planimetric infarct size). Infarct size from whole heart and left ventricular slice thallium images was expressed as a percent of the total length of the left ventricular perimeter (perimetric infarct size). This was determined from points below a certain percent of normalized peak thallium activity in the computer-generated thallium activity curve.(ABSTRACT TRUNCATED AT 250 WORDS)     

Side-to-side portacaval shunt versus nonsurgical treatment of Budd-Chiari syndrome

Although a side-to-side portacaval shunt will relieve some patients with Budd-Chiari syndrome, distinction between relief as a result of operation and spontaneous recovery may be inexact. A nonshunting operation relieved one of two patients as much as a side-to-side portacaval shunt did. In these two patients and one additional patient, streptokinase therapy may have been beneficial.     

Fate of the retained rectum after subtotal colectomy for inflammatory disease of the colon.

Of forty-nine consecutive patients who underwent subtotal colectomy for inflammatory disease of the colon, 73.5 per cent required subsequent combined abdominoperineal resection of the retained rectum and only two patients had successful ileoproctostomy. For the patient whose rectum is substantially diseased along with the rest of the colon, one-stage total proctocolectomy is the preferred operation.     

Recurrent hyperparathyroidism due to implantation of parathyroid tissue

Recurrence of hyperparathyroidism after initially successful primary operation is usually caused by inadequate resection of diseased tissue or recurrent carcinoma. Since it is known that normal parathyroid tissue may be autotransplanted into a muscle bed, it is plausible that inadvertent implantation of parathyroid tissue spilled at operation may occur. In four of 23 reoperations for hyperparathyroidism in an 11 year period, we found evidence that iatrogenic parathyroid implantation had occurred. Two of the four patients had multiple parathyroid implants in the previous operative field, and one of these patients had documented spillage of a cystic adenoma during the original operation. Another two of the four patients were found to have recurrent adenomas containing suture material at sites of previous excision of the adenomas. No patient had gross or histologic evidence of parathyroid carcinoma. We conclude that inadvertently spilled parathyroid tissue may implant in the neck or mediastinum and cause persistent or recurrent hypercalcemia. Therefore, all efforts should be made to handle the parathyroid glands only by their pedicles and not to crush, suture, or violate the capsule. Needle aspiration of parathyroid cysts could lead to implantation along the needle tract.     

Angiography in the diagnosis and management of bleeding stress ulcers and gastritis

Eighteen patients with upper gastrointestinal hemorrhage from erosive gastritis or stress ulcers were studied by selective visceral arteriography.Thirteen patients had positive results on arteriography. Vasopressin (Pituitrin) was administered intra-arterially to six patients. Bleeding was controlled completely in four patients and partially in one patient. There was no control in one patient in whom the left gastric artery was not selectively infused.     

An analysis of Korsakoff patients recall following varying types of distractor activity.

Ten alcoholic Korsakoff patients and ten alcoholic control subjects were given several short-term memory, distractor type tasks in which consonant trigrams (verbal) and random shapes (nonverbal) were employed as the to-be-retained materials. The Korsakoff patients demonstrated a severe verbal memory deficit when the retention interval was filled with verbal distractor activity, but their retention of the same verbal material was intact when a nonverbal distractor task was used. In contrast, the Korsakoff patients' retention of nonverbal material was impaired regardless of the nature of the distractor activity. In fact, their retention of nonverbal material was impaired even when an unfilled retention interval was used.     

The direct effect of tobacco smoke on the intrinsic mechanical properties of cardiac muscle

The direct effects of tobacco smoke from Kentucky University Reference cigarettes on the mechanical performance of isolated rat left ventricular muscle preparations were examined. Experiments were carried out with preparations contracting isometrically 12 times per minute at 28°C while at the apex of the length tension curve. Under oxygenated conditions, tobacco smoke bubbled through the bath induced an initial negative inotropic response. With larger volumes of smoke, initial depression was followed by recovery toward control values. Late recovery was inhibited by first passing the tobacco smoke through a Cambridge filter. Tobacco smoke added prior to 60 min of hypoxia, followed by 30 min of reoxygenation, had a dose-dependent deleterious effect on muscle performance during hypoxia and subsequent reoxygenation. The deleterious effect of smoke during hypoxia could largely be prevented by first passing the tobacco smoke through a Cambridge filter. The nicotine present in tobacco smoke could not by itself account for the changes under oxygenated conditions or those seen during hypoxia and reoxygenation. It is concluded that the gaseous phase of tobacco smoke is responsible for the negative inotropic effect seen under oxygenated conditions. The action of the particulate phase of the smoke (which is blocked at least in part by the Cambridge filter) appears to be responsible for the partial recovery of mechanical performance under oxygenated conditions and the potent deleterious effects seen during hypoxia and reoxygenation.     

Analysis of the differential diagnosis and assessment of pleuritic chest pain in young adults

The most important problem in the approach to young patients with acute pleurisy is distinguishing those with idiopathic or viral pleurisy from patients with pulmonary embolism. Three clinical features are helpful in making this distinction: (1) pleural effusion(s) present on chest roentgenography, (2) history of predisposing factors for or past history of veno-occlusive disease, and (3) physical signs indicative of phlebitis. Lung scanning should be performed in patients with these findings. If results of scanning are highly characteristic of pulmonary embolism (segmental or lobar defect with ventilation/perfusion mismatch) in such a patient, anticoagulation may be considered immediately. Patients in whom scanning reveals indeterminate characteristics or abnormalities not characteristic of pulmonary embolism should undergo pulmonary angiography if other clinical features suggest that the probability of pulmonary embolism remains at least moderately high.     

Motor function of the vagally innervated antrum following segmental gastric resection in dogs

Resection of the corpus of the stomach in the dog with preservation of the distal vagal innervation results in marked slowing of the pacesetter potential. However, the response to an ingested meal is similar in that a comparable increase in associated action potentials occurs. The segmental gastrectomy dogs indicate an increased rapidity of gastric emptying. This is explained by utilizing isolated innervated antral pouch dogs with later division of the seromuscular connection between body and antrum. Although the same slowing of PSP occurs, there's a marked increase in contraction pressure. This latter phenomenon probably accounts for the increased rapidity of gastric emptying.