The Earth as a seismic absorption band.

Attenuation of seismic waves indicates that the earth is not perfectly elastic. Dispersion accompanying absorption gives frequency-dependent "elastic" moduli, a fact that must be taken into account when inverting seismic data. Normal mode data are reinverted after correcting for absorption. The correction removes the discrepancy between body wave and free oscillation interpretations of earth structure.

Investigation of pancreatic disease.

The diagnosis of pancreatic disease is often difficult because of its retroperitoneal location and the non-specific nature of abdominal pain. There is no one test which provides all the information needed, and a series of complementary tests are generally required. This article discusses the different modalities available for investigating the patient with pancreatic disease.

Granulocytic sarcoma of the colon.

Granulocytic sarcoma is an extramedullary tumor consisting of immature cells of the granulocytic series known to occur in patients with myelodysplastic syndrome, chronic myelogenous leukemia, or acute myelogenous leukemia. This tumor may involve nodes, cervix, bone and periosteum, and infrequently the small intestine. Granulocytic sarcoma rarely occurs in the colon and has not been previously described endoscopically. We encountered a 73-year-old man with myelodysplastic syndrome who presented with fever, diarrhea, and abdominal pain. Colonoscopic evaluation (focal ulceration, friability, and nodularity) was compatible with Crohn's disease, although histology showed a dense myeloid cell infiltrate characteristic of granulocytic sarcoma. In patients with myelodysplastic syndrome or acute or chronic myelogenous leukemia presenting with diarrhea, abdominal pain, and/or fever, colonoscopy and biopsy are indicated to determine if the colon is affected by granulocytic sarcoma.