Local flow structure of turbulence in three, four, and five dimensions.

Probability density functions (PDF's) of the eigenvalues of the strain tensor of an incompressible isotropic turbulence in 3, 4, and 5 dimensions are computed by direct numerical simulation of Navier-Stokes equations. The PDF's of the smallest (negative) eigenvalue are found to be wider than those of the other ones in all dimensions and to be very insensitive to the dimension. In any dimension, the eigenvalues other than the lowest one increase as the lowest one decreases, so that they tend to be positive for the large magnitude of the lowest eigenvalue. In such a situation the flow comes in along a single direction and comes out in the other directions, which is consistent with the dynamics of the Burgers turbulence in d dimensions. It is suggested that a driving motor of most intermittent turbulent structure is the compression along a single direction. For the velocity 2 form the conditional averages of the enstrophy and the total squared strain in three dimensions are computed as functions of the smallest eigenvalue and found to be monotonically increasing as the magnitude of the smallest eigenvalue increases. Also, it is found that PDF of the source term of the Poisson equation for the pressure is positively skewed but tends to be symmetric with increase of the spatial dimension. Dimension effects on the dynamics of the most compressible eigenvalue are argued.

Hepatosplenic gamma delta T-cell lymphoma associated with hepatitis B virus infection.

Hepatitis B virus (HBV) infection has been implicated in the development of hepatocellular and hematopoietic malignancies. We describe a patient with chronic hepatitis B who developed hepatosplenic gamma delta T-cell lymphoma. A 45-year-old woman presented with marked hepatosplenomegaly and hepatic failure during the course of chronic hepatitis B. Peripheral blood examination revealed 57% abnormal lymphoid cells which expressed the gamma delta T-cell receptor. The cytogenetic analysis of tumor cells showed an abnormal karyotype; 47, XX, -13, +2mar in all 20 metaphases examined. A clonal rearrangement of the T-cell receptor genes was demonstrated by Southern blot analysis, showing monoclonal expansion of tumor cells. A liver biopsy specimen showed fibrosis of the portal areas and sinusoidal infiltration of tumor cells. HBV infection was documented by the presence of IgG anti-HBc and anti-HBs antibodies in serum. Although HBV-DNA was not detected in tumor cells by polymerase chain reaction analysis, there is a possibility that proliferation of gamma delta T cells in response to HBV infection played a role in the pathogenesis of hepatosplenic gamma delta T-cell lymphoma.

Rounded atelectasis shown by computerized tomography.

We have reported a rounded atelectasis in a 65-year-old man. On CT scan a pleural-based mass was associated with curved, ragged projections from the lower pole of the lesion. This phenomenon appears to be the counterpart of the so-called comet tail on regular tomography and, because of its clarity, may further facilitate the diagnosis of this entity.

Acute lymphoblastic leukemia following myelodysplastic syndrome.

A 58-year-old man presented with anemia and neutropenia. The bone marrow examinations showed changes consistent with myelodysplastic syndrome. Twenty months later, acute lymphoblastic leukemia developed. This case appears to represent myelodysplastic (preleukemic) syndrome terminating in acute lymphoblastic leukemia.

Sudden death from pericardial tamponade. Unusual complication of nonbacterial thrombotic endocarditis.

A ruptured myocardial infarct secondary to total coronary occlusion by a fragment of nonbacterial thrombotic endocarditis produced sudden, unexpected death in a nearly asymptomatic 82-year-old man who harbored two malignant neoplasms.

Metastasis of bronchogenic carcinoma to the skin involved by melanoma.

In a 52-year-old man, a cutaneous malignant melanoma developed concurrently with an adenocarcinoma of the right lung. The latter disseminated widely, and autopsy disclosed that it had also metastasized to the dermal tissue involved with the melanoma. Because it was not a metastasis into the substance of the melanoma, it was classified as an unusual type of "collision tumor" rather than a "cancer-to-cancer" metastasis.

Malignant fibrous histiocytoma arising in previous surgical sites. Report of two cases.

Two patients who developed malignant fibrous histiocytoma in previous surgical sites are reported. One patient developed malignant fibrous histiocytoma in an amputation site, and the other patient developed it in a previous hernioplasty scar. Both patients presented with a mass, clinically interpreted as a subcutaneous abscess. The light microscopic and fine structural features of these tumors are described. A possible causal relationship between previous surgery and malignant fibrous histiocytoma is discussed in view of other reported cases arising in various conditions following chronic reparative reactions.

Esophageal metastasis from a peripheral lung carcinoma masquerading as a primary esophageal tumor.

A 65-year-old man presented with progressive dysphagia, which proved to be the first clinical manifestation of a peripheral lung carcinoma (secondary to a submucosal metastasis in the esophagus). The lung tumor, hidden by the diaphragm on chest x-ray, was not suspected until a thoracotomy was done. Although dysphagia is known to be the first manifestation of bronchogenic carcinomas, such presentation in a case of a peripheral lung carcinoma has not been well described. This case is reported with a review of the literature for cases with dysphagia secondary to a metastatic tumor in the esophagus.