Cellular expression of ionotropic glutamate receptor subunits on specific striatal neuron types and its implication for striatal vulnerability in glutamate receptor-mediated excitotoxicity.

Glutamate receptors are composed of subtype-specific subunits. Variation in the precise subunit composition of a receptor may result in significant functional differences. Thus, a precise knowledge of subunit composition on striatal neurons is a prerequisite for understanding the selective vulnerability of striatal neurons to excitatory amino acids.

Central neural circuits for the light-mediated reflexive control of choroidal blood flow in the pigeon eye: a laser Doppler study.

Electrical stimulation in pigeons of the input from the medial subdivision of the nucleus of Edinger-Westphal (EWM) to the choroidal neurons of the ipsilateral ciliary ganglion, which themselves have input to the choroidal blood vessels of the ipsilateral eye, increases choroidal blood flow (ChBF). Since the EWM receives input from the contralateral suprachiasmatic nucleus (SCN), which in turn receives contralateral retinal input, the present study sought to determine if activation of the SCN by microstimulation or by retinal illumination of the contralateral eye would also yield increases in ChBF in that same eye. Using laser Doppler flowmetry (LDF) to measure ChBF, we found that electrical activation of the contralateral SCN by 100-Hz anodal pulse trains yielded increases in ChBF that were stimulus related and proportional to the stimulating current.

Differential diagnosis of fever and pulmonary densities in mechanically ventilated patients.

Sepsis continues to represent a major threat to the recovery of mechanically ventilated patients and a serious challenge to physicians in charge of their care. Diagnosis of pneumonia is made difficult by numerous infectious and noninfectious conditions that may present in a clinically similar fashion. Clinical criteria are insensitive in identifying extrapulmonary sources of fever.

Metoprolol metabolism via cytochrome P4502D6 in ethnic populations.

Objective: The objective of this study was to determine whether metabolism via cytochrome P4502D6 (CYP2D6) was higher in Black subjects than White subjects.

Methods: Ten Black and 10 White healthy male volunteers who were phenotyped CYP2D6 extensive metabolizer phenotypes participated in this randomized, cross-over study in which metoprolol was used as a model CYP2D6 substrate. In both study phases, subjects received oral rac-metoprolol tartrate (200 mg); during one phase, subjects also took quinidine sulfate (100 mg) daily beginning 3 days before the dose of metoprolol.

Regulatory factors acting at the bacteriophage Mu middle promoter.

Lytic development of bacteriophage Mu proceeds through three phases of transcription: early, middle, and late. Initiation of middle transcription from Pm requires the phage-encoded activator, Mor. An examination of the sequences surrounding the promoter revealed possible binding sites for Mu proteins A and c, as well as for Escherichia coli integration host factor.

Clinical observations of metabolic changes occurring in renal transplant recipients receiving ketoconazole.

Metabolism of cyclosporine is reduced by ketoconazole binding to the monooxygenase responsible for cyclosporine degradation. This isozyme of cytochrome P450, along with other similar monooxygenases, is involved in the regulation of the synthesis and degradation of important metabolic pathways of cholesterol. Monooxygenases throughout these pathways are inhibited by ketoconazole binding causing a decreased metabolism of calcitriol, bile acids, and steroid hormones, and can thereby potentiate altered lipid metabolism, bone metabolism, and weight status of transplant recipients.

Glutamatergic and GABAergic postsynaptic responses of striatal spiny neurons to intrastriatal and cortical stimulation recorded in slice preparations.

Glutamatergic and GABAergic responses of the neostriatal spiny neurons to intrastriatal and cortical stimulation were characterized by intracellular recording in brain slice preparations. This study also demonstrated the role of each response in the spike activity of the spiny neuron. Single neostriatal stimulation induced postsynaptic potentials consisting of multiple components.

Relative frequency of a subclavian vs. a transverse cervical origin for the dorsal scapular artery in humans.

Background: The origin of the dorsal scapular artery to the rhomboid muscles in humans has been the subject of uncertainty. The present study sought to clarify which of its two most common sources (the transverse cervical artery or the subclavian artery) is the major source of the dorsal scapular artery.

Methods: Gross anatomical dissection was used to visualize the origin and course of the dorsal scapular artery in human cadavers.

Transcription activation by the bacteriophage Mu Mor protein: analysis of promoter mutations in Pm identifies a new region required for promoter function.

Middle transcription of bacteriophage Mu requires Escherichia coli RNA polymerase holoenzyme and a Mu-encoded protein, Mor. Consistent with these requirements, the middle promoter, Pm, has a recognizable -10 region but lacks a -35 region. Mutagenesis of this promoter (from -70 to +10) was performed using mutagenic oligonucleotide-directed PCR.

Identification of a glucocorticoid repressor domain in the rat beta 1-adrenergic receptor gene.

The expression of the gene encoding the rat beta 1-adrenergic receptor is suppressed by glucocorticoids (Kiely et al., 1994). Within the 3.

Use of the sensitive anterograde tracer cholera toxin fragment B reveals new details of the central retinal projections in turtles.

Previous anterograde degeneration and autoradiographic studies have yielded inconsistent results on the extent and target areas of the central retinal projections in turtles. We used the highly sensitive anterograde and retrograde tracer, cholera toxin B fragment (CTB), to re-examine the central retinal projections in Pseudemys scripta elegans. In contrast to the results of the previous anterograde degeneration studies and autoradiographic studies, immunohistochemical detection of CTB-labeled central retinal axons and terminals revealed these projections with great morphological detail and clarity.

Using bronchoalveolar lavage to distinguish nosocomial pneumonia from systemic inflammatory response syndrome: a prospective analysis.

Objective: Ventilator-associated pneumonia (PN) is difficult to distinguish from trauma-induced systemic inflammatory response syndrome (SIRS), especially in patients with multiple injuries. Previous work using bronchoscopy and quantitative cultures demonstrated significant bacterial growth in about one-third of patients with clinical evidence of PN. In this prospective study, antibiotic therapy for PN was based solely on quantitative bronchoalveolar lavage (BAL) cultures.

Glomerulosclerosis as a determinant of posttransplant function of older donor renal allografts.

Transplantation of kidneys from older donors is being advocated to expand the organ donor pool. However, the prevalence of atherosclerosis and age-induced renal structural alterations account for the variable function of allografts procured from these older donors. Pretransplant biopsies are sometimes used to evaluate kidneys from older donors, but to date there are no defined criteria correlating the extent of structural alterations in these kidneys to subsequent function.

Temperature effects on malonyl-CoA inhibition of carnitine palmitoyltransferase I.

Malonyl-CoA inhibition of hepatic mitochondrial carnitine palmitoyltransferase I and malonyl-CoA binding were measured at temperatures ranging from 0 degrees C to 37 degrees C. Protease treatment of mitochondria resulted in greatly diminished malonyl-CoA binding, indicating that the method used detected malonyl-CoA binding sites located on the outer surface of the mitochondrial outer membrane as expected. The apparent Ki for malonyl-CoA inhibition was found to increase with increasing temperature.

Thalamostriatal projection neurons in birds utilize LANT6 and neurotensin: a light and electron microscopic double-labeling study.

Based on its location, connectivity and neurotransmitter content, the dorsal thalamic zone in birds appears to be homologous to the intralaminar, midline, and mediodorsal nuclear complex in the thalamus of mammals. We investigated the neuroactive substances used by thalamostriatal projection neurons of the dorsal thalamic zone in the pigeon. Single-labeling experiments showed that many neurons in the dorsal thalamic zone are immunoreactive for neurotensin and the neurotensin-related hexapeptide, (Lys8,Asn9)NT(8-13) (LANT6).

Effects of parenteral and enteral nutrition on gut-associated lymphoid tissue.

Changes in mucosal defense have been implicated as important factors affecting infections complications in critically ill patients. To study the effects of nutrient administration on gut-associated lymphatic tissue (GALT), ICR mice were randomized to receive chow plus intravenous saline, intravenous feeding of a total parenteral nutrition (TPN) solution, or enteral feeding of the same TPN solution. In a second series of experiments, a more complex enteral diet (Nutren) was compared with chow feeding and enteral TPN.

Prognostic factors after acute subdural hematoma.

Factors that have been shown to affect outcome after acute subdural hematoma (ASDH) include age, Injury Severity Score (ISS), intracranial pressure (ICP), direct admission to a trauma center, presence of subarachnoid hemorrhage, score on the Glasgow Coma Scale (GCS), and timing of operation. However, these data come from selected patient populations (e.g.

Potassium currents responsible for inward and outward rectification in rat neostriatal spiny projection neurons.

Many of the nonlinear membrane properties displayed by neostriatal spiny projection neurons are conferred by their voltage-gated potassium (K+) currents, including an inwardly rectifying current (IKir), fast (IAt), and slowly (IAs)-inactivating A-currents, and a slow, noninactivating current. The relative contribution of these K+ currents to the pronounced inward and outward rectification of the current-voltage (I-V) relationship of spiny neurons was investigated in a neostriatal slice preparation. Manipulation of the equilibrium potential for K+ (EK) showed that the voltage dependence of activation of inward rectification was identical to that of IKir.

Stimulation of muscle glucose disposal by insulin in humans is a function of the preexisting plasma insulin level.

To examine whether tissue sensitivity to insulin is dependent upon the prevailing plasma insulin concentration, the ability of acute hyperinsulinemia to stimulate glucose disposal was investigated in six normal subjects before and after prolonged reduction of the plasma insulin concentration. Glucose turnover ([6,6-2H2]glucose), whole body glucose oxidation and nonoxidative glucose disposal (indirect calorimetry), and glycogen synthase activity in muscle were determined in the postabsorptive and in the insulin-stimulated states (euglycemic hyperinsulinemic clamp: 3 mU.kg-1.

Diabetes and proteolysis: effects on carnitine palmitoyltransferase-I and malonyl-CoA binding.

Malonyl-CoA binding and malonyl-CoA inhibition of carnitine palmitoyltransferase-I (CPT-I) were measured in hepatic mitochondria from normal and diabetic rats and in protease-treated mitochondria from fed rats to test the hypothesis that proteolysis represents a mechanism by which diabetes produces changes in the sensitivity of CPT-I to inhibition by malonyl-CoA. As in diabetes, protease treatment increased the apparent Ki values for malonyl-CoA. Palmitoyl-CoA greatly diminished malonyl-CoA specific binding in the mitochondrial system being studied, suggesting strong competition at the malonyl-CoA binding site.

Organization of the avian "corticostriatal" projection system: a retrograde and anterograde pathway tracing study in pigeons.

Birds have well-developed basal ganglia within the telencephalon, including a striatum consisting of the medially located lobus parolfactorius (LPO) and the laterally located paleostriatum augmentatum (PA). Relatively little is known, however, about the extent and organization of the telencephalic "cortical" input to the avian basal ganglia (i.e.

Simultaneous determination of N, N-di(n-butyl)doxorubicin-14-valerate and its 8 urinary metabolites by HPLC.

Aim: To develop an HPLC assay for simultaneous determination of AD202 and its metabolites and to examine metabolites of AD202 in urine of rats.

Methods: Reverse-phase HPLC with fluorescence detection and gradient elutionusing a Waters Chromatograph equipped with a 710 B WIFP autosampler, a power Mate SX plus computer, C18 Nova-pak (4 microns) 5 mm x 10 cm radial compression column connected with a guard micro-column, and a Waters 991 photodiode array detector for online observation of UV spectrum of related fraction.

Results: Detection limit was 1-3 ng for AD202 and 1-3 ng for its metabolites per injection.

Alterations in intracellular calcium chelation reproduce developmental differences in repetitive firing and afterhyperpolarizations in rat neocortical neurons.

Many 1-week-old rat sensorimotor cortical neurons exhibit extreme spike-frequency adaptation (neurons only fire for the first 100-250 ms of a 1 s current injection) accompanied by a large, prolonged afterhyperpolarization (AHP). Relatively greater expression of a Ca-dependent K+ current appears to underlie the extreme adaptation observed in immature cells. In the present study, we examined whether altering intracellular Ca2+ buffering by introducing Ca2+ chelators via the recording electrode could reproduce the age-related differences in firing and AHPs.