Regulation of protein kinase C activity by sensory deprivation in the olfactory and visual systems.

Environmental regulation of sensory function has provided an important model of plastic mechanisms mediating neural information processing. To define potential commonalities in information processing in different systems, we investigated molecular changes elicited by sensory deprivation in the developing rat olfactory and visual systems. Protein kinase C (PKC), an intracellular messenger implicated in synaptic plasticity and memory, was analyzed.

The use of taped parental interviews to improve communication with childhood cancer families.

Communication with the parents of children with cancer is essential. Denial of information given, confusion over details, and emotional distress all prevent comprehension by parents. Information-giving sessions were taped and the effect this had on parental contentment and understanding was assessed.

Hematologic correlates of left atrial spontaneous echo contrast and thromboembolism in nonvalvular atrial fibrillation.

Objectives: This study examined the relation between left atrial spontaneous echo contrast, hematologic variables and thrombo-embolism in patients with nonvalvular atrial fibrillation.

Background: Left atrial spontaneous echo contrast is associated with left atrial stasis and thromboembolism in patients with nonvalvular atrial fibrillation. However, its hematologic determinants in patients with nonvalvular atrial fibrillation are unknown.

Depolarizing influences increase low-affinity NGF receptor gene expression in cultured Purkinje neurons.

Multiple cellular and molecular interactions are required for the differentiation and development of central neurons. For example, neural activity may modulate trophic function. In the developing cerebellum, establishment of functional excitatory synaptic connections coincides with the expression of NGF and its receptors.

Pacemakers, defibrillators, and direct current cardioversion.

Technology for pacemakers and automatic implantable defibrillators continues to evolve. Emphasis is placed not only on preventing cardiac death, but also on improving symptoms and quality of life. The basic antibradycardia function of pacemakers is complemented by highly sophisticated rate-responsive capabilities.

Differential actions of neurotrophins in the locus coeruleus and basal forebrain.

The neurotrophin gene family, including nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), neurotrophin-3 (NT-3), and NT-4/NT-5, supports the survival of distinct peripheral neurons, however, actions upon central neurons are relatively undefined. In this study we have compared different neurotrophins in the regulation of neuronal survival and function using dissociated embryonic cell cultures from two brain regions, the basal forebrain (BF) and locus coeruleus (LC). In the BF, NGF increased choline acetyl transferase (ChAT) activity, but did not influence cholinergic cell survival.

Detection of dystrophin in the postsynaptic density of rat brain and deficiency in a mouse model of Duchenne muscular dystrophy.

Duchenne muscular dystrophy (DMD) is a common, lethal, chromosome X-linked inherited disease. Moderate cognitive impairment is a feature of DMD, but the underlying mechanisms are unknown. DMD is characterized by a defect in a protein, dystrophin, that is located predominantly in muscle but has been detected in brain.

Neurotrophic interactions in the nervous system.

Traditional views have suggested that information flow in the nervous system is dependent on millisecond-to-millisecond communication occurring in a point-to-point manner. However, recent evidence suggests that growth and trophic functions are central to development and maintenance of function in the brain. In turn, trophism occurs over days to weeks to months and appears to underlie processes as diverse as learning, memory and development, on the one hand, and the pathogenesis of disease, on the other.

Transoesophageal echocardiography in heart disease--old technologies, new tricks.

Cardiac ultrasound and upper gastrointestinal endoscopy are relatively old technologies. With the introduction of new ultrasound probes and by incorporating ultrasound technology into conventional endoscopes, 'new tricks' in cardiac imaging were discovered. Posterior structures of the heart are now able to be imaged clearly by the ultrasound probe from the oesophagus.

Mesencephalic type I astrocytes mediate the survival of substantia nigra dopaminergic neurons in culture.

We previously demonstrated that substantia nigra (SN) support cells selectively increase SN dopamine (DA) neuron survival in dissociated primary culture. Increased survival was elicited specifically by nigral support cells; glia from other brain regions exerted lesser effects. We now report that Type I astrocytes, the principal component of SN support cell monolayers, mediate the enhanced DA cell survival.

Embolization of a left atrial ball thrombus during transesophageal echocardiography.

We report a case of systemic embolization of a left atrial ball thrombus during transesophageal echocardiography (TEE). A 49-year-old man with rheumatic mitral stenosis and atrial fibrillation underwent TEE to evaluate a transient cerebral ischemic attack. TEE demonstrated a free-floating left atrial thrombus.

On the identity of the major postsynaptic density protein.

Increasing evidence suggests that the postsynaptic density (PSD) plays a critical role in synaptic communication and plasticity. The major PSD protein (mPSDp), a calcium/calmodulin-dependent protein kinase, appears to be central to PSD function. The mPSDp has long been considered identical to the alpha subunit of the soluble calmodulin kinase II (alpha-CKII).

Decreases in apolipoprotein(a) after renal transplantation: implications for lipoprotein(a) metabolism.

Serum concentrations of apolipoprotein(a) [apo(a)], the unique glycoprotein of lipoprotein(a), are increased in patients with end-stage renal failure. We prospectively studied serum apo(a) and other lipoproteins in 20 consecutive patients, ages 46 +/- 11 years, before and for six months after successful renal transplantation. All patients received cyclosporine, and no patient was treated for hyperlipidemia.

Role of transoesophageal echocardiography in evaluation of cardiogenic embolism.

Objective: To determine the value of transoesophageal echocardiography in the assessment of selected patients at risk of cardiogenic embolism or after it.

Design: Prospective comparison of the results of transoesophageal and transthoracic echocardiography. Transoesophageal echocardiography was performed with a 5 MHz single plane phased array transducer.

Regulation of NGF gene expression in CNS glia by cell-cell contact.

Nerve growth factor (NGF) gene expression in central nervous system (CNS) glia appears to be associated with active glial growth. To study the underlying molecular mechanisms, we examined the effects of a number of growth-related factors on NGF mRNA expression in glial cultures. Our results suggest that glial membrane interaction, as a consequence of growth, actively inhibits NGF gene expression in CNS glia.

Left atrial spontaneous echo contrast: a clinical and echocardiographic analysis.

The clinical and echocardiographic variables related to left atrial spontaneous echo contrast were prospectively evaluated in a consecutive series of 400 patients undergoing transesophageal echocardiography with a 5-MHz single plane transducer. Left atrial spontaneous echo contrast was found in 75 patients (19%) and was significantly associated with atrial fibrillation, mitral stenosis, absence of mitral regurgitation, increased left atrial dimension and a history of suspected embolism. Seventy-one (95%) of the patients with spontaneous echo contrast had atrial fibrillation or mitral stenosis.

Depolarizing stimuli regulate nerve growth factor gene expression in cultured hippocampal neurons.

Although trophic factors and neuronal activity have been implicated in regulating functional synaptic circuits, the relationship of trophic interaction to impulse activity in synaptogenesis remains unclear. Using cultured hippocampus as a model system, we provide direct evidence that depolarization and impulse activity specifically increase nerve growth factor gene expression in neurons. Depolarizing stimuli, such as a high K+ concentration or the Na+ channel agonist veratridine, elicited a 3-fold increase of nerve growth factor mRNA levels in both explant and dissociated cultures.

Role of voltage-sensitive calcium channels in mitogenic stimulation of neuroblasts.

The present study examines the role of Ca2+ in the regulation of sympathetic neuroblast mitosis. Employing a fully defined neuroblast culture system, we previously found that insulin growth factors (IGFs), depolarization and vasoactive intestinal peptide (VIP) regulated precursor mitosis. We now report that Ca2+ entry via voltage-sensitive channels was required for depolarization-stimulated mitogenesis.

Visual experience specifically regulates synaptic molecules in rat visual cortex.

Abstract To study environmental modulation of synaptic molecular structure, the major postsynaptic density protein (mPSDp) from rat visual cortex was monitored. This membrane component, a Ca(2+)/calmodulin-dependent protein kinase subunit, was measured during normal postnatal development and after visual deprivation. Total synaptic membrane (SM) protein was used as an index of synapses as a whole.

Multiple coronary artery-left ventricular fistulae: clinical, angiographic, and pathologic findings.

Multiple fistulae between all 3 major coronary arteries and the left ventricle were found at cardiac catheterization in a 69-year-old woman presenting with typical angina. Subsequent necropsy showed abnormal intramyocardial vessels communicating with the left ventricular lumen. This is the first report to document clinical, angiographic, and pathologic findings in this anomaly.

Local support cells promote survival of substantia nigra dopaminergic neurons in culture.

Recent studies suggest that brain neurons require extracellular signals for continued survival during maturity as well as development. However, factors underlying the survival of specific populations of central neurons remain to be defined. To examine the regulation of neuronal survival, we have studied the substantia nigra (SN) dopaminergic (DA) system, in dissociated cell culture.

Sexually dimorphic expression of the NGF receptor gene in the developing rat brain.

To define relations between trophic molecules and known sexually dimorphic traits in brain, we examined possible sex differences in nerve growth factor (NGF) and NGF receptor (NGF-R) gene expression in the rat cholinergic basal forebrain (BF)-hippocampal system. Hippocampal NGF mRNA levels did not differ between sexes; in contrast, BF NGF-R mRNA levels were greater in neonatal females than males, paralleling the known dimorphic development of cholinergic enzyme activity. Cerebellar NGF-R mRNA levels were also dimorphic in the neonate, suggesting that sex-specific influences may regulate trophic receptor gene expression in diverse brain systems.

NGF gene expression in actively growing brain glia.

Previous work suggested that brain NGF acts locally on cells adjacent to sites of synthesis, in addition to any putative actions on distant, projecting perikarya. To define the basis of local action, we used a sensitive nuclease protection assay to identify cells expressing the NGF gene in vivo and in vitro. In addition to neurons, glia from a variety of developing brain areas synthesized NGF mRNA, suggesting that CNS glia exhibit a generalized capacity to express the gene.

Transesophageal echocardiography in acute aortic transection.

Confirming the diagnosis of acute transection of the descending aorta can be problematic. Unnecessary patient movement and time delay are often associated with conventional investigations. We describe a patient in whom such an injury was clearly and quickly defined at the bedside by transesophageal echocardiography.

NGF and excitatory neurotransmitters regulate survival and morphogenesis of cultured cerebellar Purkinje cells.

The development of cerebellar Purkinje cells is subject to regulation by multiple epigenetic signals. To define mechanisms by which trophic and presynaptic stimulation may potentially regulate Purkinje cell ontogeny, we studied the effects of NGF and excitatory transmitters on Purkinje cell survival and morphological maturation in dissociated cell culture. Purkinje cells were identified by expression of vitamin D-dependent calcium-binding protein and by their characteristic morphology.