Inhibition of polymorphonuclear leukocyte adherence suppresses no-reflow after focal cerebral ischemia in baboons.

BACKGROUND AND PURPOSE: While polymorphonuclear leukocytes may contribute to the "no-reflow" phenomenon after focal cardiac and skeletal muscle ischemia/reperfusion, their contribution to acute focal cerebral ischemia is unresolved. We have examined the role of polymorphonuclear leukocytes in microvascular perfusion defects after focal cerebral ischemia/reperfusion in a baboon model of reversible middle cerebral artery occlusion with the anti-CD18 monoclonal antibody IB4, which inhibits neutrophil adherence to endothelium. METHODS: Microvascular patency in the basal ganglia after 3-hour middle cerebral artery occlusion and 1-hour reperfusion (by india ink tracer perfusion) was quantified by computerized video imaging. Animals were randomized to receive intravenous IB4 infusion 15 minutes before reperfusion (n = 7) or to receive no treatment (n = 6). Binding of IB4 to baboon leukocytes was maximal within 5 minutes of infusion. RESULTS: In the untreated group, a significant reduction in patency was observed in microvessels less than 30 microns diameter: mean percent reflow was 51% in the capillary diameter class (4.0-7.5 microns) and 39% in the precapillary arteriole and postcapillary venule diameter class (7.5-30 microns). Infusion of IB4 before middle cerebral artery reperfusion increased reflow in microvessels of all size classes, most significantly in those 7.5-30 microns (p = 0.049) and 30-50 microns (p = 0.034) in diameter. CONCLUSIONS: These results suggest that CD18-mediated polymorphonuclear leukocyte-endothelium adherence contributes to no-reflow predominantly in noncapillary microvessels and at least partially to that in capillaries.     

Differential diagnosis of adrenal masses by chemical shift and dynamic gadolinium enhanced MR imaging

Chemical shift MRI is widely used for identifying adenomas, but it is not a perfect method. We determined whether combined dynamic MRI methods can lead to improved diagnostic accuracy. Fifty-seven adrenal masses were examined by chemical shift and dynamic MR imaging using 2 MR systems. The masses included 38 adenomas and 19 non-adenomas. In chemical shift MRI studies, the signal intensity index (SI) was calculated, and the lesions classified into 5 types in the dynamic MRI studies. Of the 38 adenomas studied, 37 had an SI greater than 0. In the dynamic MRI, 34 of 38 adenomas showed a benign pattern (type 1). If the SI for the adenomas in the chemical shift MRI was considered to be greater than 0, the positive predictive value was 0.9, and the negative predictive value was 0.94 and kappa = 0.79. If type 1 was considered to indicate adenomas in the dynamic MRI, the corresponding values were 0.94, 0.81 and kappa = 0.77 respectively. The results obtained when the 2 methods were combined were 1, 0.95 and kappa = 0.96 respectively. The chemical shift MRI was found to be useful for identifying adenomas in most cases. If the adrenal mass had a low SI (0 < SI < 5), dynamic MRI was also found to be helpful for making a differential diagnosis.     

Papovavirus detection by electron microscopy in the brain of an elderly patient without overt progressive multifocal leukoencephalopathy

Virions resembling papovavirus were demonstrated in glial cells in the brain of an aged patient without overt progressive multifocal leukoencephalopathy. The patient was not in a severely immunocompromised state. On histological examination, only a few tiny incomplete necrotic foci were found in the subcortical area. These foci were widely dispersed. Rare, swollen oligodendroglial cells and astrocytes in which papovavirus capsid protein (VP-1) was demonstrated immunohistochemically were present around the foci. The two typical types of virus particles i.e. 35 to 40 nm round particles and elongated particles, were observed in the nuclei of the swollen glial cells. The latter were in the minority. Distinct crystals were also found in the nuclei. The centre-to-centre distance of the particles in the crystals, about 40 nm, and the electron-opaque spots of the round-shaped virions and of the elongated particles, were indicative of structural subunits of papovavirus capsids. This case provides further evidence that papovavirus, possibly JC virus, may be reactivated in the brains of aged patients who are not in an immunocompromised state.     

Expression cloning of gamma interferon-inducing antigens of Mycobacterium avium subsp. paratuberculosis

Three recombinant proteins, Map10, Map39, and Map41, produced based on nucleotide sequences obtained from the screening of Mycobacterium avium subsp. paratuberculosis genomic library expressed in Escherichia coli significantly elicited gamma interferon production in peripheral blood mononuclear cells from infected cattle. Two of these proteins were members of the PPE protein family.     

Hemolymph lectin of the pearl oyster, Pinctada fucata martensii: a possible non-self recognition system

To elucidate a mutual correlation between the hemolymph lectin and hemocytes of the pearl oyster, Pinctada fucata martensii, we searched for common epitopes and ligands. Neither the hemocyte plasma membrane nor cytoplasm was immunoreactive to anti-hemolymph lectin antibody. The hemolymph lectin strongly bound to D-galactose and N-acetyl-D-galactosamine, and the plasma membrane of both granulocytes and agranulocytes had affinity only for D-mannose and N-acetyl-D-glucosamine-binding plant lectins. In the gonad, the hemolymph lectin selectively adsorbed injected horse red blood cells (HRBC), and its hemagglutinating activity probably prevented them from dispersing. Pinctada sp. may possess system of recognition of non-self by the hemolymph lectin.     

Isolation of amantadine-resistant influenza a viruses (H3N2) from patients following administration of amantadine in Japan

In Japan, the use of amantadine for treatment of influenza A virus infection was not accepted until November 1998, although it was widely used for treatment of Parkinsonism. Since then, we have monitored the emergence of amantadine-resistant viruses and isolated two viruses from patients on long-term treatment with amantadine.     

Comparison of an immunochromatography test with multiplex reverse transcription-PCR for rapid diagnosis of respiratory syncytial virus infections

A new commercial rapid 10-min one-step immunochromatography (IC) test, SAS RSV test, was compared to another IC test, Directigen EZ RSV, employing RT-PCR as the "gold standard" for detecting respiratory syncytial virus. Of 102 clinical samples, 79 were positive by RT-PCR, 66 (82.5%) were positive with the SAS RSV test, and 55 (69.6%) were positive with Directigen EZ RSV. The specificity of the new test was 91.3% (21 of 23), similar to that of Directigen EZ RSV (100% [23 of 23]). This test performs well enough to be used for patient care.     

Malignant histiocytosis. A report of three cases.

Three cases of malignant histiocytosis were immunohistochemically studied. The cases included the following three patients: a 38-year-old man, a 44-year-old man, and a girl aged 5 years 9 months. All three patients died within 3 months of hospitalization. They had a high fever (temperature over 38.5 degrees C), lymph node swelling, hepatosplenomegaly, and pancytopenia. Blastoid and hemophagocytic cells proliferated in the bone marrow and lymph nodes, especially in the sinuses of the latter. We diagnosed malignant histiocytosis in the three cases based on clinical features, extremely poor prognoses, and the morphologic features and growth pattern of blastoid and hemophagocytic cells. Blastoid and hemophagocytic cells expressed phenotype Mac-387+/KP1+/lysozyme+/polyclonal CD3+. The Mac-387 and KP1 antigens and lysozyme are markers for monocytes/macrophages, and polyclonal CD3 is a marker for T lymphocytes. Therefore, we suggest that a certain number of cases of malignant histiocytosis have a biphenotypic nature, namely, the T cell and macrophage, although many cases of malignant histiocytosis have been reported as expressing only T-lymphocyte antigens.