Jeffrey Allen

Learn More
Methylmercury (MeHg) is a significant environmental contaminant that will continue to pose great risk to human health. Considerable attention in the scientific and health policy fora is focused on the question of whether MeHg intake from a diet high in fish is associated with aberrant CNS function. A number of recent studies (Kjellstrom et al., 1986:(More)
This paper examines long-term block ownership by corporations and performance changes in firms with corporate block owners. We also examine potential reasons for corporate ownership including benefits in product market relationships, alleviation of financing constraints, and board monitoring by corporate owners. We find the largest significant increases in(More)
Astrocytes are essential for removal of glutamate from the extracellular space in the central nervous system. The neurotoxic heavy metal methylmercury potently and specifically inhibits the transport of glutamate in cultured astrocytes by an unknown mechanism. Glutamate transport in astrocytes is also inhibited by reactive oxygen species. A(More)
One of the vitally important functions of glutathione (GSH) is to adequately protect cells against toxic chemicals, reactive oxygen metabolites and free radical species. The amino acid, cysteine, is the key rate-limiting substrate for the biosynthesis of GSH, and the maintenance of adequate intracellular GSH levels is dependent upon the extracellular(More)
Neuroglial cells of the central nervous system include the astrocytes, oligodendrocytes, and microglia. Their counterparts in the peripheral nervous system are the Schwann cells. The term neuroglia comes from an erroneous concept originally coined by Virchow (1850), in which he envisioned the neurons to be embedded in a layer of connective tissue. The term,(More)
Maintenance of the ionic and osmotic composition of the extracellular fluid (ECF) is essential for the optimal functioning of the central nervous system (CNS). Changes in ion and neurotransmitter levels in the cerebrospinal fluid (CSF) can have profound effects on the processing and transmission of neuronal signals. Cell swelling during correction of(More)
beta-amyloid peptide (Abeta) has been implicated in the pathogenesis of Alzheimer disease and has been reported to induce apoptotic death in cell culture. Cysteine proteases, a family of enzymes known as caspases, mediate cell death in many models of apoptosis. Multiple caspases have been implicated in Abeta toxicity; these reports are conflicting. We show(More)
BACKGROUND Despite the extensive use of intrathecal morphine infusion for pain, no systematic safety studies exist on its effects in high concentrations. The authors assessed the effects of morphine and clonidine given 28 days intrathecally in dogs. METHODS Beagles with lumbar intrathecal catheters received solutions delivered by a vest-mounted infusion(More)
Maintenance of adequate intracellular glutathione (GSH) levels is vital for intracellular defense against oxidative damage. The toxic effects of methylmercury (MeHg) are attributable, at least in part, to elevated levels of reactive oxygen species, and thus decreases in GSH synthesis may increase methylmercury toxicity. Astrocytes have recently been(More)