Gastric carcinoma in patients younger than age 36 years.

The clinical and pathologic features of 18 patients with gastric carcinoma younger than age 36 years were studied. Of these patients, 36.8% were Hispanics of Mexican origin. Eighteen percent of the Mexican population with gastric carcinoma were younger than 36 years as compared to 2.8% of the overall population (P less than 0.05). Fifty percent of the gastric ulcers in the Mexican population were malignant as compared to 6% in the non-Mexican population (P less than 0.05). In addition, a subset of aggressive carcinomas were found. Patients presenting with symptoms of less than 6 months' duration had a survival of less than 6 months, compared to the less aggressive subset, in which patients had symptoms for greater than 6 months and survived longer than 6 months. Racial, environmental influences, or selection bias may account for the differences in gastric carcinoma in the Mexican and non-Mexican population. Factors contributing to a more aggressive form of carcinoma are unclear and require further study.

Radiation dose enhancement therapy with iodine in rabbit VX-2 brain tumors.

Loading tissue with iodine enhances the radiation dose absorbed from low energy X-rays. In order to test whether this is a useful procedure for treating brain tumors, we infused radiographic contrast media into rabbits carrying VX-2 brain tumors and delivered 15 Gy of 120 kVp X-rays in 3 fractions to the tumor. From CT scans we estimated that the dose enhancement was approximately 30%. The median survival times, after tumor detection on CT, of untreated rabbits, treated with radiation alone, and treated with radiation plus contrast media were 3, 25.5, 38.5 days, respectively. The repeated infusion of contrast media, 3.5 g of iodine per kg of body weight, did not affect kidney function as measured by serum creatinine levels. This method of enhancing radiation dose in brain tumors therefore appears promising.

Aortic mural thrombus: an occult source of arterial thromboembolism.

During a 28-year period from 1955 to 1983, two cases of massive repetitive arterial thromboembolism from nonaneurysmal aortic mural thrombus were diagnosed antemortem and successfully corrected at the University of California, Los Angeles Medical Center. Within the same time period, 48 cases of nonaneurysmal aortic mural thrombus were identified in 10,671 consecutive autopsies (0.45% incidence). Eight of these patients had evidence of distal embolization (17%), and three had major thromboembolic occlusions, which were considered the proximate cause of death (6%). The latter three patients represented 9% of autopsy-confirmed deaths from peripheral arterial thromboembolism. The diagnosis was established in a 49-year-old man and a 51-year-old woman after a long course marked by recurrent arterial embolization. Despite multiple evaluations, which included angiography, the diagnosis remained elusive until clinical suspicion resulted in complete biplane aortographic survey. Although the morphologic characteristics of this lesion are quite striking, subtle angiographic changes and lack of familiarity with the clinical presentation contribute to the difficulty and infrequency of diagnosis. This unique lesion comprises an important segment of the so-called cryptogenic sources of arterial embolization and can be corrected by a definitive surgical procedure.

Development of rabbit brain tumor model for radiologic research.

A rabbit brain tumor model using transplanted VX-2 carcinoma had an 85% rate of successful implantation. Rabbits lived 8.5 +/- 1.3 days. The tumor doubling time was 0.5 to 2.6 days. Some tumors were shown as early as four days after implantation and all tumors were seen by ten days after implantation. Two of three rabbits receiving radiation therapy to the tumor had significant extension of life. This model is a useful radiologic research tool.

Epidemiology of diarrhea due to rotavirus on an Indian reservation: risk factors in the home environment.

Analysis of outpatient visits for diarrheal disease at the San Carlos Apache Reservation, Arizona, during 1977-1979 revealed a sharp increase in cases of infantile gastroenteritis of unknown etiology in October and November of each year. During the 1980 autumn diarrhea season, 19 patients and 12 control subjects were selected from among outpatients under two years of age and were interviewed and studied for bacterial and viral enteric pathogens. Eleven (58%) of 19 patients and two (17%) of 12 control subjects were positive for fecal rotavirus by enzyme-linked immunosorbent assay (P = 0.03). Ten (91%) of 11 rotavirus-positive patients were under one year of age. The most significant risk factor for illness was the presence of a household contact under the age of two years (P - 0.004). Dog ownership was also associated with rotavirus infection (P = 0.05).