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Biomedical subjects

L A Marco

Publications and source records attributed to L A Marco.

At least 37 records · Page 2Linked to original sources
PubMed1984

Lithium and lecithin treatment in Alzheimer's disease: a pilot study.

Ten patients with presumed Alzheimer's disease were entered into a pilot study to evaluate the combined effects of lithium and lecithin on cognitive and behavioral parameters. The loss of patients from the study because of toxic effects of lithium was high (30%), and one patient was dropped because of an intervening illness. Of the six remaining patients who completed the study, only two showed behavioral improvement; none showed improvement on measures of cognitive functioning. The possible mechanisms of action are discussed.

Aged↗
PubMed1984

Possible lithium-induced extrapyramidal effects in Alzheimer's disease.

Extrapyramidal symptomatology has previously been reported in patients on long-term lithium maintenance. This report emphasizes that, in the presence of organic mental disorder, even brief treatment with lithium may induce severe extrapyramidal signs. Furthermore, toxicity to lithium may occur even though serum lithium levels are at therapeutic levels. Following termination of lithium, symptoms subsided quickly in one patient (five days), but more slowly in the other (16 days). Possible pathophysiology of this phenomenon is discussed.

Alzheimer Disease↗
PubMed1982

Attenuation of catecholamine-coupled adenylate cyclase following surgical isolation of rat caudate.

Six weeks following complete unilateral surgical isolation of the rat caudate nucleus, activation of adenylate cyclase was reduced in response to dopamine (DA), norepinephrine (NE), 5' -guanylyl-imidodiphosphate [Gpp(NH)p], DA + Gpp(NH)p, and NaF. The low Km form of cyclic AMP phosphodiesterase was elevated in the isolated side when compared to the intact caudate. No changes in activities of guanylate cyclase or in high Km cyclic AMP phosphodiesterase (with or without the calcium-dependent regulator protein, calmodulin or CDR) were observed between the control and isolated caudate. Histologically, the neural damage to the isolated caudate was principally confined to reduced numbers of dendritic spines of the remaining intrinsic caudate neurons.

3',5'-Cyclic-AMP Phosphodiesterases↗
PubMed1980

Regeneration of the forebrain of the Japanese carp, Cyprinus carpio: a Golgi analysis.

The regeneration of the forebrain of the Japanese carp, Cyprinus carpio was examined with the rapid Golgi method. Characteristic of both 40 and 70 day regenerated forebrains was a proliferation of the spine processes of ependymal cells. Concomitant with this spinous augmentation was the appearance of swellings in many of the processes. Adjacent to the ependyma were cells that appeared to bud-off the ependyma and become migrating neuroblasts. The examination of the neurons in both normal and regenerated forebrains revealed no obvious and consistent differences between the configurations in both cases. In contrast to this finding, examination of the incoming axons showed numerous swellings and enlargements which were presumed to be immature synapses. The signifiance of these findings to the regeneration of the forebrain is discussed.

Animals↗
PubMed1979

Effects of mercuric chloride on the resting membrane potentials of blue crab (Callinectes sapidus) muscle fibers.

The effects of concentrations of mercuric chloride ranging from 3.68 to 368 microM (1--100 ppm) on the resting membrane potentials of muscle fibers in the extensor muscle of the carpopodite in walking legs of adults blue crabs were investigated in vitro. Glass micropipettes filled with saturated solutions of potassium chloride and conventional electronic equipment were used. Resting membrane potentials in uncontaminated artificial sea water averaged -78 mV +/- 4 mV (S.E.M.). Mercuric chloride added to the control bath at 3.68 or 9.2 microM did not affect the resting membrane potentials. At 18.4 microM threshold effects were obtained in 50% of the preparations. At concentrations ranging from 25.7 to 368 microM progressive deterioration of membrane polarization occurred as the mercury concentration was increased. This effect was irreversible despite multiple washes with normal sea water. We conclude that mercuric chloride has very powerful toxic effects at the peripheral motor effector elements in blue crabs. These results do not, of course, rule out more central effects on enzymatic systems or neuronal networks.

Animals↗
PubMed1979

Succinylcholine drug interactions during electroconvulsive therapy.

Electroconvulsive therapy (ECT) is frequently described as being almost free of absolute contraindications. However, drug interactions with succinylcholine pose potential hazards to which this paper calls attention. In addition to its neuromuscular-blocking action, succinylcholine has other acetylcholine-like effects. Drugs which inhibit cholinesterase activity or which inhibit acetylcholine release or synthesis may produce prolonged respiratory paralysis when combined with succinylcholine. The increasing longevity of the population receiving chemotherapy for physical ailments implies that greater numbers of these patients may also become candidates for ECT and therefore be at risk for adverse drug interactions with succinylcholine. Of particular importance to the psychiatrist are the various psychotropic drugs that have been reported to interact with succinylcholine. Precautions in using drug combinations and treatment of complications are described.

Animals↗
PubMed1976

The rodent neostriatum: a Golgi analysis.

In the adult rodent, coronal sections of Golgi impregnations of the neostriatum display a compact segregation of axon fascicles, neuronal clusters, and dendritic bundles thus forming an areolar configuration. Isolated neurons are rarely seen. The dorsomedial region of the neostriatum appears free of axon fascicles and dendritic bundles. Horizontal and sagittal sections of the neostriatum show clusters of cells parallel to axon fascicles. The neurons exhibit spine-laden dendrites with an initial spine-free segment. Neonatal impregnations exhibit a different configuration. Neonatally, cells tend to cluster but there is no bundling of dendrites. Neurons are spine-free or have protospines on the soma and the dendrites, including the initial segment. Transition from neonate to adult configuration is discernible at about 15 days after birth. The neostriatum of carnivores exhibits a different structure from the rodent neostriatum. This difference is associated with a developed anterior limb of the internal capsule in the carnivore. The axon fascicle-free portion of the carnivore neostriatum lacks dendritic bundles and pallisades. Portions near the capsule with axon fascicles appear similar to the rodent neostriatum with dendritic bundlings and pallisading. Such findings emphasize the importance of total neuronal configuration (neuronal-architectonics) in morphologic analyses.

Animals↗