Right ventricular outflow muscle in tetralogy of Fallot: Histologic and immunohistochemical monoclonal antibody analysis.

To evaluate progressive muscular right ventricular outflow tract (RVOT) obstruction in tetralogy of Fallot (TOF), we hypothesized that this tissue would demonstrate more prominent selected immunohistochemical markers of myogenous cell differentiation, growth factor/receptor, and extracellular matrix. Sections of formalin-fixed, paraffin-embedded myectomy tissue obtained from RVOT at the time of surgical correction of TOF (n = 32; ages = 3 months through 13 years) were compared with age-matched tissue from the RVOT of normal control hearts (n = 12) obtained at autopsy after non-cardiac death. Examining by light microscopy slides stained with a combination of hematoxylin and eosin and elastic trichrome revealed cardiomyocyte (CM) hypertrophy, extensive myofiber disarray, trabeculation, multinucleation (more than two nuclei per myocyte), fibrosis, and thick-walled coronary arteries within the myocardium of TOF tissue.

Functional neuroanatomy of the nigrostriatal and striatonigral pathways as studied with dual probe microdialysis in the awake rat--II. Evidence for striatal N-methyl-D-aspartate receptor regulation of striatonigral GABAergic transmission and motor function.

In the present study we used the dual probe approach to investigate striatal N-methyl-D-aspartate receptor regulation of GABA release from the substantia nigra pars reticulata of the awake, freely moving rat. One microdialysis probe of concentric design was implanted in the dorsolateral striatum and another in the ipsilateral substantia nigra pars reticulata. Perfusion with N-methyl-D-aspartate (100 microM) in the dorsolateral striatum decreased local dopamine release (-25%) and increased both glutamate (+40%) and GABA (+35%) release.

Functional neuroanatomy of the nigrostriatal and striatonigral pathways as studied with dual probe microdialysis in the awake rat--I. Effects of perfusion with tetrodotoxin and low-calcium medium.

In the present study we employed the dual probe approach to investigate functional interactions between the nigrostriatal dopaminergic and striatonigral GABAergic pathways in the awake, freely moving rat and their role in motor function. One microdialysis probe of concentric design was implanted in the substantia nigra pars reticulata and another in the ipsilateral dorsolateral striatum. Perfusion with a low-Ca2+ (0.

Hippocampal cell distributions in temporal lobe epilepsy: a comparison between patients with and without an early risk factor.

Neuronal cell distributions were measured for anterior and posterior locations in the hippocampi of epilepsy patients who were seizure-free after temporal lobectomy. Patients were divided into two groups, those with an early risk factor, defined as a neurologic insult occurring in the first 4 years of life, and those with no early risk factor. Early-risk patients had lower hilar cell densities, lower granule cell densities, and fewer granule cells per millimeter, a measured related to total granule cell number, than to early risk patients.

Capillary electrophoresis with laser-induced fluorescence detection: a sensitive method for monitoring extracellular concentrations of amino acids in the periaqueductal grey matter.

The use of capillary electrophoresis with laser-induced fluorescence detection (CE-LIF) for the analysis of microdialysate samples from the periaqueductal grey matter (PAG) of freely moving rats is described. By employing 3-(4-carboxybenzoyl)-2-quinoline-carboxaldehyde (CBQCA) as a derivatization agent, we simultaneously monitored the concentrations of 8 amino acids (arginine, glutamine, valine, gamma-amino-n-butyric acid (GABA), alanine, glycine, glutamate, and aspartate), with nanomolar and subnanomolar detection limits. Two of the amino acids (GABA and glutamate) were analysed in parallel by conventional high-performance liquid chromatography (HPLC) in order to directly compare the two analytical methods.

Early results of continuous passive motion after rotator cuff repair: a prospective, randomized, blinded, controlled study.

Purpose: To determine the effect of continuous passive motion (CPM) on rotator cuff repair (RCR).

Methods: A prospective, randomized, blinded, controlled study was performed on all patients undergoing primary RCR between December 1992 and January 1994. A preoperative "shoulder score" was calculated for each patient based on four scales: function (50%), pain (20%), muscle strength (15%), and range-of-motion (ROM) (15%).

Merkel cell carcinoma.

Background: Merkel cell carcinoma is an aggressive tumor with nonspecific clinical features. The prognosis in general is worse than malignant melanoma. Local recurrence rates are high with one-third of patients having recurrence within one year of excision.

The secretory trypsin inhibitor like-peptide, PEC-60 increases dopamine D2 receptor agonist induced inhibition of GABA release in the dorsolateral neostriatum of the awake freely moving rat. An in vivo microdialysis study.

The effects of local perfusion with the secretory trypsin inhibitor like-peptide, PEC-60 on dopamine and gamma-aminobutyric acid (GABA) release in the dorsolateral neostriatum and GABA release in the globus pallidus were studied using in vivo microdialysis in the awake freely moving rat. Local perfusion with PEC-60 (500 nM and 1 microM) increased dopamine release in the dorsolateral neostriatum while the highest (1 microM) concentration of PEC-60 decreased striatal but not pallidal GABA release. An inactive form of the peptide, S-carboxyamidomethylated PEC-60 (1 microM) failed to influence either striatal dopamine and GABA or pallidal GABA release.

The usefulness of transesophageal echocardiography in diagnosing cardiac contusions.

Objectives: To assess the usefulness of transesophageal echocardiography in diagnosing cardiac contusions in patients with blunt trauma.

Background: For more than a decade, noninvasive tests, including ECGs, cardiac enzymes, nuclear studies, and transthoracic echocardiography have been utilized in an attempt to identify trauma patients with cardiac injuries. These tests have been imperfect in identifying the patients at high risk for mortality.

Differential cholinergic regulation of dopamine release in the dorsal and ventral neostriatum of the rat: an in vivo microdialysis study.

We used in vivo microdialysis to investigate the effects of local perfusion with the AChE inhibitor neostigmine on the basal and haloperidol evoked increase in dialysate dopamine levels in the dorsolateral and fundus striata of the bilaterally implanted halothane anaesthetized rat. In the absence of neostigmine basal dopamine was consistently higher in the dorsolateral striatum compared with the fundus striati. Local perfusion with neostigmine (10 and 100 microM) increased basal dopamine in the fundus striati compared to the contralateral (control) side but not in the dorsolateral striatum.

Repeated spinal cord stimulation decreases the extracellular level of gamma-aminobutyric acid in the periaqueductal gray matter of freely moving rats.

Most of the previous experimental studies on the antinociceptive effects of electrical spinal cord stimulation (SCS) have focused on short-lasting effects mainly depending on spinal mechanisms. However, patients treated with SCS for chronic pain often report pain relief exceeding the period of stimulation for several hours. The long lasting effect of SCS might not only involve spinal, but also supraspinal mechanisms.

Receptor-receptor interactions and their relevance for receptor diversity. Focus on neuropeptide/dopamine interactions.

Receptor diversity in combination with receptor-receptor subtype specific interactions, which can be antagonistic or synergistic in character, markedly increase plasticity in WT and VT in the nervous system. In this way switching among transmission lines for the various DA receptor subtypes becomes possible. Some of these aspects are supported by our work on selective modulation of D2 receptors by CCK and NT.

Caffeine enhances acetylcholine release in the hippocampus in vivo by a selective interaction with adenosine A1 receptors.

Caffeine is a commonly used drug that increases arousal, a condition associated with increased cholinergic activity in the mammalian cerebral cortex including the hippocampus. We have used the technique of microdialysis in association with microbore high-performance liquid chromatography to investigate the effects of caffeine on the extracellular levels of acetylcholine in the hippocampus of awake, freely moving rats. The oral administration of caffeine dose-dependently (3-30 mg/kg) increased the extracellular levels of acetylcholine.

Longitudinal variation in cell density and mossy fiber reorganization in the dentate gyrus from temporal lobe epileptic patients.

Variation in cell loss and mossy fiber reorganization was examined along the longitudinal axis of the dentate gyrus from temporal lobe epileptic (TLE) patients. Previous evidence has indicated that the anterior hippocampus is prone to seizure activity. We compared granule and hilar cell number in addition to Timm stain density of the molecular layer and hilus in more anterior and more posterior specimens of hippocampus obtained from patients surgically treated for intractable epilepsy by the removal of the anterior half of the hippocampus.

Neurotensin peptides antagonistically regulate postsynaptic dopamine D2 receptors in rat nucleus accumbens: a receptor binding and microdialysis study.

An in vitro receptor binding and in vivo microdialysis study was performed to further investigate the modulation of dopamine (DA) D2 receptors by neurotensin (NT) peptides. Saturation experiments with the D2 agonist [3H]NPA (N-propylnorapomorphine) showed that 10 nM of NT, 10 nM of neuromedin N (NN) and 1 nM of the C-terminal NT-(8-13) fragment significantly increased the KD values by 125%, 181%, and 194%, respectively without significantly affecting the Bmax value of the [3H]NPA binding sites in coronal sections of rat ventral forebrain mainly containing the nucleus accumbens (Acb) and the olfactory tubercle. In line with the previous findings that NT can increase GABA release in the Acb and that NT receptors are not found on DA terminals in this brain region, the present in vivo microdialysis study demonstrated that local perfusion of NT (1 nM) counteracted the D2 agonist pergolide (2 mu M) induced inhibition of GABA, but not of DA release in the rat Acb.

Immunohistology, cytogenetics, and molecular studies of small round cell tumors of childhood. A review.

Malignancies of childhood include a well-defined spectrum of hematolymphoid, organ specific (adrenal, kidney, liver), soft tissue, bone, and nervous system (central and peripheral) neoplasms with variable biology. Small round cell neoplasms, a subset of childhood malignancies, are histologically similar but differ markedly in their histogenesis, therapy, and prognosis. Traditionally, clinical information and light microscopy, with the aid of histochemistry and ultrastructural evaluation, establish a diagnosis or at least narrow the differential diagnosis.

N-methyl-D-aspartic acid biphasically regulates the biochemical and electrophysiological response of A10 dopamine neurons in the ventral tegmental area: in vivo microdialysis and in vitro electrophysiological studies.

The effects of local perfusion of the ventral tegmental area (VTA) with N-methyl-D-aspartic acid (NMDA) on extracellular dopamine concentrations in the nucleus accumbens were investigated by using in vivo microdialysis in halothane anaesthetized rats. The electrophysiological response of VTA dopamine neurons to NMDA were also assessed in an in vitro rat brain slice preparation. In both preparations NMDA elicited a biphasic response.

Antagonistic interaction between adenosine A2A receptors and dopamine D2 receptors in the ventral striopallidal system. Implications for the treatment of schizophrenia.

Recent studies have shown the existence of a specific antagonistic interaction between adenosine A2a receptors and dopamine D2 receptors in the brain. This A2a-D2 interaction seems to be essential for the behavioural effects of adenosine agonists and antagonists, like caffeine. In the present study quantitative receptor autoradiography and brain microdialysis were combined to demonstrate a powerful antagonistic A2a-D2 interaction in the ventral striopallidal system.

Modulation of striatal aspartate and dynorphin B release by cholecystokinin (CCK-8) studied in vivo with microdialysis.

Sulphated cholecystokinin-8 (CCK-8) given into the neostriatum of the rat by in vivo microdialysis produced a concentration-dependent (1-100 microM) increase in extracellular aspartate (Asp) and dynorphin B (Dyn B), but not in glutamate, GABA or dopamine levels. The increase in Asp levels produced by 10 microM CCK-8 was approximately 10 fold and was inhibited (approximately 50%) by the CCKB antagonist L-365,260 (20 mg kg-1, i.p.

The striatonigral dynorphin pathway of the rat studied with in vivo microdialysis--II. Effects of dopamine D1 and D2 receptor agonists.

In vivo microdialysis was used to study the effect of intracerebral administration of dopamine agonists on dynorphin B release in the striatum and substantia nigra of rats. The release of dopamine and GABA was also investigated. Administration of the dopamine D1 agonist SKF 38393 (10-100 microM) into the striatum increased extracellular dynorphin B and GABA levels in the ipsilateral substantia nigra, in a concentration-dependent manner.

The striatonigral dynorphin pathway of the rat studied with in vivo microdialysis--I. Effects of K(+)-depolarization, lesions and peptidase inhibition.

Extracellular levels of dynorphin B were analysed with in vivo microdialysis in the neostriatum and substantia nigra of halothane-anaesthetized rats. Dopamine and its metabolites, 3,4-dihydroxyphenyl-acetic acid and homovanillic acid, as well as GABA were simultaneously monitored. Chromatographic analysis revealed that the dynorphin B-like immunoreactivity measured in perfusates collected under basal and K(+)-depolarizing conditions co-eluted with synthetic dynorphin B.

Acute toluene exposure decreases extracellular gamma-aminobutyric acid in the globus pallidus but not in striatum: a microdialysis study in awake, freely moving rats.

Intracerebral brain microdialysis was performed in awake, freely moving rats to study the effect of acute inhalation exposure of toluene (2000 ppm, 2 h) on extracellular levels of gamma-aminobutyric acid (GABA) within the globus pallidus and the striatum. GABA within the globus pallidus decreased (20%) during and after (26%) exposure to toluene, while no reduction was seen in the striatal GABA level during exposure. After the exposure there was a tendency towards an increase (maximally 37%) in striatal GABA.