Monocytic leukemia in three cats.

Of 3 cats with monocytic leukemia, 1 responded favorably to treatment with cytosine arabinoside. With supportive therapy, it lived 78 days from the time of diagnosis, at which time it developed dyspnea and signs of toxicosis and died. The other 2 cats did not respond to treatment and died 4 and 16 days from time of diagnosis. Prior to death, they were bleeding from injection sites, and their blood had greater than 200,000 WBC/mm3. Necropsy of those 2 cats revealed extensive perivascular hemorrhagic infarcts within the cerebellum, medulla, and cerebrum.     

Homogenization of northern U.S. Great Lakes forests due to land use

Human land use of forested regions has intensified worldwide in recent decades, threatening long-term sustainability. Primary effects include conversion of land cover or reversion to an earlier stage of successional development. Both types of change can have cascading effects through ecosystems; however, the long-term effects where forests are allowed to regrow are poorly understood. We quantify the regional-scale consequences of a century of Euro-American land use in the northern U.S. Great Lakes region using a combination of historical Public Land Survey records and current forest inventory and land cover data. Our analysis shows a distinct and rapid trajectory of vegetation change toward historically unprecedented and simplified conditions. In addition to overall loss of forestland, current forests are marked by lower species diversity, functional diversity, and structural complexity compared to pre-Euro-American forests. Today’s forest is marked by dominance of broadleaf deciduous species—all 55 ecoregions that comprise the region exhibit a lower relative dominance of conifers in comparison to the pre-Euro-American period. Aspen (Populus grandidentata and P. tremuloides) and maple (Acer saccharum and A. rubrum) species comprise the primary deciduous species that have replaced conifers. These changes reflect the cumulative effects of local forest alterations over the region and they affect future ecosystem conditions as well as the ecosystem services they provide. Electronic Supplementary Material The online version of this article (doi:) contains supplementary material, which is available to authorized users. An erratum to this article can be found at     

Neuropeptide Y distribution in the rat brain

A massive neuronal system was detected by immunocytochemistry and radioimmunoassay with antibodies to neuropeptide Y, the recently isolated peptide of the pancreatic polypeptide family. Immunoreactive cell bodies and fibers were most prevalent in cortical, limbic, and hypothalamic regions. Neuropeptide Y was extracted in concentrations higher than those of any other peptide hitherto discovered in the mammalian brain. Column chromatography of brain extracts and double immunostaining experiments indicate that neuropeptide Y is the endogenous brain peptide responsible for immunostaining of pancreatic polypeptide-like immunoreactivity in the mammalian brain.     

Lack of coincidence between neural and behavioral manifestations of cortical spreading depression

The presence of cortical spreading depression is typically inferred from the presence of hypesthesia. The electrocorticogram and slow-potential change were recorded during cortical spreading depression and it was found that hypesthesia remained long after the cortex recovered from neural depression. Hypesthesia, therefore, is an unreliable indicant of cortical spreading depression; if cortical spreading depression is used as a research tool, neural activity must be monitored. These data offer a special problem for memory transfer studies.