Nonsuppurative meningoencephalitis associated with Aleutian mink disease parvovirus infection in ranch mink.

Severe nonsuppurative meningoencephalitis associated with Aleutian mink disease parvovirus (ADV) infection was observed in adult ranch mink. Brain lesions included severe, locally extensive to coalescing lymphoplasmacytic meningoencephalitis with accompanying gliosis, satellitosis, and mild extension of inflammation into the leptomeninges. ADV was identified in mesenteric lymph node, spleen, brain, and liver of affected mink by polymerase chain reaction techniques. Sequences of the ADV isolate (TH5) revealed 2 unique residues in the region of the viral genome that determines pathogenicity. These findings suggest that certain strains of ADV may preferentially cause disease in the nervous system. ADV infection should be considered in the differential diagnosis of neurologic disorders in mink.     

A Large Drop in Atmospheric 14C/12C and Reduced Melting in the Younger Dryas, Documented with 230Th Ages of Corals

Paired carbon-14 ((14)C) and thorium-230((230)Th) ages were determined on fossil corals from the Huon Peninsula, Papua New Guinea. The ages were used to calibrate part of the (14)C time scale and to estimate rates of sea-level rise during the last deglaciation. An abrupt offset between the (14)C and (230)Th ages suggests that the atmospheric (14)C/(12)C ratio dropped by 15 percent during the latter part of and after the Younger Dryas (YD). This prominent drop coincides with greatly reduced rates of sea-level rise. Reduction of melting because of cooler conditions during the YD may have caused an increase in the rate of ocean ventilation, which caused the atmospheric (14)C/(12)C ratio to fall. The record of sea-level rise also shows that globally averaged rates of melting were relatively high at the beginning of the YD. Thus, these measurements satisfy one of the conditions required by the hypothesis that the diversion of meltwater from the Mississippi to the St. Lawrence River triggered the YD event.     

Magnesium pemoline: failure to affect in vivo synthesis of brain RNA

The effect of magnesium pemoline on the synthesis of brain RNA in vivo was studied. No significant effect either on the concentration of RNA or on the uptake of H(3)-uridine into RNA was detected.     

An extremely luminous panchromatic outburst from the nucleus of a distant galaxy

Variable x-ray and γ-ray emission is characteristic of the most extreme physical processes in the universe. We present multiwavelength observations of a unique γ-ray-selected transient detected by the Swift satellite, accompanied by bright emission across the electromagnetic spectrum, and whose properties are unlike any previously observed source. We pinpoint the event to the center of a small, star-forming galaxy at redshift z = 0.3534. Its high-energy emission has lasted much longer than any γ-ray burst, whereas its peak luminosity was ～100 times higher than bright active galactic nuclei. The association of the outburst with the center of its host galaxy suggests that this phenomenon has its origin in a rare mechanism involving the massive black hole in the nucleus of that galaxy.     

Mechanism of a reaction in vitro associated with delayed-type hypersensitivity

The cell type responsible for inhibition by antigen of migration in vitro of peritoneal exudate cells obtained from tuberculin-hypersensitive guinea pigs was studied. Exudate populations were separated into component cell types, the lymphocyte and the macrophage. Peritoneal lymphocytes from sensitive donors were the immunologically active cells in this system, the macrophages, being merely indicator cells which migrate. Sensitized peritoneal lymphocyte populations, upon interaction with specific antigen in vitro, elaborated into the medium a soluble material capable of inhibiting migration of normal exudate cells.