Experimental evidence for the origin of ductal-type adenocarcinoma from the islets of Langerhans

To investigate the role of the islets of Langerhans in pancreatic carcinogenesis, freshly isolated islets from male Syrian hamsters were transplanted into the right submandibular glands of 50 female hamsters that were or were not pre-treated with streptozotocin. Thyroid gland fragments, cellulose powder, and immortal hamster pancreatic ductal cells were injected into the left submandibular gland of the same hamsters. All recipient hamsters were then treated with the potent pancreatic carcinogen N-nitrosobis(2-oxopropyl)amine weekly at a dose of 40 mg/kg of body weight for 3 weeks. Between 3 and 8 weeks later, 18 of 75 (24%) hamsters developed large ductal-type adenocarcinomas in the submandibular gland region, where islets were transplanted, but none developed tumors in the left submandibular gland. In 9 of 18 hamsters, tumors were multiple so that a total of 31 cancers were found. Eleven of these carcinomas were in the vicinity of transplanted islets, eight of which showed intra-insular ductular or cyst formation as seen in the pancreas of hamsters during pancreatic carcinogenesis. The formation of ductular structures within islets was also demonstrated in vitro. Some tumor cells in the vicinity of these islets were reactive with anti-insulin. Y chromosome message was found by polymerase chain reaction analysis in one of the three tumors examined. Also, like the induced pancreatic tumors, all three submandibular gland tumors that were examined had the mutation of the c-Ki-ras oncogene at codon 12 and all tumors expressed blood group A antigen. These and other findings strongly suggest that some components of islets, most probably stem cells, are the origin of ductal-type adenocarcinomas in this model.     

Cardiac tamponade due to Nocardia asteroides

Pericarditis with hemodynamic compromise is a rare manifestation of infection with Nocardia asteroides. To our knowledge, only six cases have been reported previously. In contrast to other cases of pericardial disease due to Nocardia, culture of the pericardial fluid in our case was negative while culture of pericardial tissue led to the diagnosis. Surgical intervention and appropriate antibiotic therapy are essential in the treatment of Nocardia pericarditis.     

Ultrastructural PMP22 expression in inherited demyelinating neuropathies

The purpose of this study was to determine the accuracy of a video system which our laboratory has been using to measure soft tissue strain. Both static and dynamic error analyses were performed to assess the accuracy of our video system. Static error was defined as the amount of movement reported by the video system for markers that were stationary. Dynamic error was defined as the difference between the motion of the markers as reported by the video system and their actual motion. Two sets of fluorescent markers were attached to a servo-hydraulic materials test machine. One marker set was attached to the hydraulic actuator (moving markers) and the other set was attached to the base of the machine (stationary markers). Five different marker sizes, five camera distances, and seven different loading rates were studied. Results indicated that the static error was independent of marker size, and that the dynamic error was independent of the loading rate and marker size for loading rates of 50% of the camera field of view (CFV) per second or slower. For loading rates greater than 50 percent of CFV per second, the marker size did have an affect on the dynamic error. The mean static error was found to be 0.026 percent of CFV and the mean dynamic error was found to be 0.062 percent of CFV.     

Radioiodine therapy for hyperthyroidism in young patients--perception of risk and use

In the radiation treatment of inclined lesions the longitudinal axis of beam should be always parallel to the longitudinal axis of lesion in the treatment plane. Hence the choice of correct collimator angle is of prime importance in the oblique field off-axis treatment planning of inclined lesions. In this paper a graphical method is discussed to determine the collimator angles from the CT scans taken at different off-axis planes. A phantom was constructed which can simulate conditions like inclined lesion in the patient and CT scans were taken at different levels. The collimator angles estimated from CT scans are found to match with the collimator angles obtained from simulator within +/- 1 degree for various gantry angles. The method is applied to plan a case of cancer of the oesophagus (upper third), which is a typical example of inclined lesion.     

Egg shell nodal calcification in a patient with sinus histiocytosis with massive lymphadenopathy treated with interferon

CT showed egg shell calcification in the cervical lymph nodes in a patient with sinus histiocytosis with massive lymphadenopathy treated for 1 year with interferon. CT scans before interferon treatment had shown no nodal calcification.