Scintigraphic evaluation of disorders of the esophagus, stomach, and duodenum

Gastrointestinal nuclear medicine procedures have progressed from the stage of anatomic imaging alone to their present applications in studying gastrointestinal function and pathophysiology. These tracer techniques have several specific advantages over other procedures. Scintigraphy requires no intubation, has excellent patient acceptance, is quantitative, and delivers lower radiation burdens to the patient than does the contrast radiographic study. Currently, nuclear medicine functional scintigraphy in gastroenterology is being applied clinically in many medical centers throughout the world.     

Viewing time and stereoscopic threshold with random-dot stereograms

The effect of viewing time on the threshold for depth and form discrimination using random-dot stereograms has been investigated. For 12 subjects the relation between logarithm of threshold disparity and logarithm of viewing time was linear for both depth and form discrimination, but the threshold for form discrimination was approximately twice the threshold for depth discrimination. Stereo thresholds determined with random-dot stereograms were not significantly related to stereo thresholds measured with a Howard-Dolman apparatus.     

Spectrum of coronary arterial spasm. Clinical, angiographic and myocardial metabolic experience in 29 cases

A relationship of coronary arterial spasm to variant angina pectoris, subendocardial ischemia, major ventricular arrhythmias and myocardial infarction has been demonstrated. In 29 patients, spasm was angiographically observed in normal-appearing coronary arteries (7 patients) as well as superimposed on various degrees of coronary atherosclerotic obstruction (22 patients). All patients experienced an atypical anginal syndrome;16 patients also experienced typical exertional angina. Coronary spasm appeared to be a major contributory factor in eight occurrences of myocardial infarction and in 11 incidents of ventricular tachycardia, ventricular fibrillation and heart block. Coronary spasm in the 29 cases was distributed in the following fashion: left main trunk, 6 cases; right main trunk, 12 cases; proximal left anterior descending artery, 13 cases; proximal circumflex artery, 1 case; distal left anterior descending artery, 1 case; and distal circumflex artery, 2 cases. In 5 cases coronary spasm was noted at multiple sites.     

Investigations of the normal stability of Chopart''s joint (author''s transl)

A total of 132 strains of anaerobic bacteria were tested for susceptibility to josamycin, using a broth dilution technique. All strains of Peptococcus species, Peptostreptococcus species, and Bacteroides fragilis were inhibited by 2 mug or less per ml. Seventy percent of these susceptible strains were also killed by 2 mug or less of josamycin per ml. However, 2 of 12 Clostridium species and 6 of 10 Fusobacterium species had minimum inhibitory concentrations of 32 mug or more per ml.     

Acquisition of American sign language by a noncommunicating autistic child

Clinical and in vitro investigations were carried out to test the efficacy of gut lavage, hemodialysis, and hemoperfusion in the treatment of poisoning with paraquat or diquat. In a patient suffering from diquat intoxication 130 times more diquat was removed by gut lavage 30 h after ingestion than was removed by complete aspiration of the gastric contents. Determination of in vitro clearances for paraquat and diquat by hemodialysis showed that, at serum concentrations of 1-2 ppm, such as are frequently encountered in poisoning in man, toxicologically relevant quantities of herbicide cannot be removed from the body. At a concentration of 20 ppm, on the other hand, hemodialysis proved to be effective, the clearance being 70 ml/min at a blood flow rate of 100 ml/min. The efficacy of hemoperfusion with coated activated charcoal was on the whole better. Especially at concentrations around 1-2 ppm, the clearance values for hemoperfusion were some 5-7 times higher than those for hemodialysis. In a patient suffering from paraquat poisoning, both hemodialysis as well as hemoperfusion were carried out. The in vitro results could be confirmed: At serum concentrations of paraquats less than 1 ppm no clearance could be obtained by hemodialysis while by hemoperfusion with activated charcoal quite high clearance values were measured and the serum level dropped down to zero.     

9-Nor-9-hydroxyhexahydrocannabinols. Synthesis, Some behavioral and analgesic properties, and comparison with the tetrahydrocannabinols

The racemic mixture and levo isomer of both 9-nor-9alpha-hydroxyhexahydrocannabinol and its 9beta-hydroxy isomer were prepared. Both alpha-and beta-hydroxy compounds were active in the dog ataxia test and depressed spontaneous activity in mice. However, only the beta-hydroxy compound was an analgesic in mice morphine-like potency. The behavioral and analgesic properties of these compounds may be mediated through different sites or mechanisms and may, therefore, be separable.     

Subcutaneous implants of polypropylene filaments

Extruded filaments of unmodified polypropylene (PP) with and without antioxidant were implanted subcutaneously in hamsters in order to determine their rate of degradation. Specimens were removed periodically during a 5 month test period and analyzed by infrared spectroscopy and dynamic mechanical testing. The analyses show that degradation beigns to occur after only a few days. Although the reaction sequence is not known, several factors suggest that the in vivo degradation process is similar to autoxidation which occurs in air or oxygen. The infrared data indicate that the hydroxyl content of the implants increases at a rate of 0.061 mg/g polypropylene per day during the initiation phase of the reaction. An induction time of 108 days was extablished. Carbonyl bonds appear after an implantation time of 50--90 days and increase therafter. Mechanical tests indicate a decrease in the dynamic loss tangent, tan delta, during the first month of implantation for unmodified polypropylene. No change in the infrared spectra or tan delta was observed, however, for implants containing an antioxidant. Thus, it is apparent that polypropylene filaments implanted subcutaneously in hamsters degrade by an oxidation process which is retarded effectively by using an antioxidant. While the findings reported are specific to subcutaneous polypropylene implants, they suggest that degradation of other systems may involve similar processes. This notion suggests directions for further research on increasing the in vivo stability of synthetic polymers. Long-term effects of polymer implantation upon tissue were not studied in this work.