Public health nurses' encounters with undocumented migrant mothers and children.

Objectives: Undocumented migrant children (UMC) are often affected by policies and practices that do not take their best interests into account. The aim of this study was to describe how public health nurses (PHNs) experienced challenges and dilemmas in ensuring the best interests of the undocumented migrant child.

Design: This study had a qualitative descriptive design.

Who prescribes buprenorphine for rural patients? The impact of specialty, location and practice type in Washington State.

We determined the specialty, geographic location, practice type and treatment capacity of waivered clinicians in Washington State. We utilized the April 2011 Drug Enforcement Agency roster of all waivered buprenorphine prescribers and cross-referenced the data with information from the American Medical Association and online resources. Waivered physicians, as compared to Washington State physicians overall, are more likely to be primary care providers, be older, less likely to be younger than 35 years, and more likely to be female.

Kinetics of a novel isoform of phosphate activated glutaminase (PAG) in SH-SY5Y neuroblastoma cells.

We have recently found that the neuroblastoma cell line SH-SY5Y expresses a novel form of phosphate activated glutaminase (PAG) which deamidates glutamine to glutamate and ammonia at high rates. Glutamate production is enhanced during the exponential phase of growth, and decreases when cell proliferation stops. Neuroblastoma PAG exists in a soluble and membrane associated form, and both the phosphate and the glutamine kinetics, as well as the effects of ammonia and glutamate are different from those of the known forms of PAG.

Novel form of phosphate activated glutaminase in cultured astrocytes and human neuroblastoma cells, PAG in brain pathology and localization in the mitochondria.

A novel form of phosphate activated glutaminase (PAG), catalyzing the synthesis of glutamate from glutamine, has been detected in cultured astrocytes and SH-SY5Y neuroblastoma cells. This enzyme form is different from that of the kidney and liver isozymes. In these cells we found high enzyme activity, but no or very weak immunoreactivity against the kidney type of PAG, and no immunoreactivity against the liver type.

Kinetics and localization of brain phosphate activated glutaminase.

The cellular concentration of phosphate, the main activator of phosphate activated glutaminase (PAG) is rather constant in brain and kidney. The enzyme activity, however, is modulated by a variety of compounds affecting the binding of phosphate, such as glutamate, calcium, certain long chain fatty acids, fatty acyl CoA derivatives, members of the tricarboxylic acid cycle and protons (Kvamme et al. [2000] Neurochem.

Phosphate-activated glutaminase and mitochondrial glutamine transport in the brain.

A review of the properties of purified and tissue bound phosphate activated glutaminase (PAG) in brain and kidney (pig and rat) is presented, based on kinetic, electron microscopic and immunocytochemical studies. PAG is a mitochondrial enzyme and two pools can be separated, a soluble and membrane associated one. Intact mitochondria appear to express PAG accessible only to the outer phase of the inner mitochondrial membrane.

Properties and submitochondrial localization of pig and rat renal phosphate-activated glutaminase.

Two pools of phosphate-activated glutaminase (PAG) were separated from pig and rat renal mitochondria. The partition of enzyme activity corresponded with that of the immunoreactivity and also with the postembedding immunogold labeling of PAG, which was associated partly with the inner membrane and partly with the matrix. The outer membrane was not labeled.

Glutamine transport in brain mitochondria.

Gln is transported into rat brain synaptic and non-synaptic mitochondria by a protein catalyzed process. The uptake is significantly higher in synaptic than in non-synaptic mitochondria. The transport is inhibited by the amino acids Glu, Asn and Asp, and by the TCA cycle intermediates succinate, malate and 2-OG.

Phosphate activated glutaminase is concentrated in mitochondria of sensory hair cells in rat inner ear: a high resolution immunogold study.

Glutamate has been implicated in signal transmission between sensory hair cells and afferent fibers in the inner ear. However, the mechanisms responsible for glutamate replenishment in these cells are not known. Here we provide evidence that phosphate activated glutaminase, which is thought to be the predominant glutamate-synthesizing enzyme in the brain, is concentrated in all types of hair cell in the organ of Corti and vestibular epithelium.

Inhibition of glutamine transport in rat brain mitochondria by some amino acids and tricarboxylic acid cycle intermediates.

Glutamine transport into rat brain synaptic and non-synaptic mitochondria has been monitored by the uptake of [3H]glutamine and by mitochondrial swelling. The concentration of glutamate in brain mitochondria is calculated to be high, 5-10 mM, indicating that phosphate activated glutaminase localized inside the mitochondria is likely to be dormant and the glutamine taken up not hydrolyzed. The uptake of [3H]glutamine is largely stereospecific.

Postembedding immunogold labelling reveals subcellular localization and pathway-specific enrichment of phosphate activated glutaminase in rat cerebellum.

Phosphate activated glutaminase is a key enzyme in glutamate synthesis. Here we have employed a quantitative and high-resolution immunogold procedure to analyse the cellular and subcellular expression of this enzyme in the cerebellar cortex. Three main issues were addressed.

Glutamine transport in rat brain synaptic and non-synaptic mitochondria.

Glutamine transport into rat brain mitochondria (synaptic and non-synaptic) was monitored by the uptake of [3H]glutamine as well as by mitochondrial swelling. The uptake is inversely correlated to medium osmolarity, temperature-dependent, saturable and inhibited by mersalyl, and glutamine is upconcentrated in the mitochondria. These results indicate that glutamine is transported into an osmotically active space by a protein catalyzed mechanism.

The orientation of phosphate activated glutaminase in the inner mitochondrial membrane of synaptic and non-synaptic rat brain mitochondria.

When rat brain synaptic and non-synaptic mitochondria were incubated with [14C]glutamine, [14C]glutamate was rapidly released to the incubation medium, and the release was stimulated by phosphate, whereas [14C]glutamate accumulated very slowly in the mitochondria and independently of the addition of phosphate. The specific activity of [14C]glutamate (dpm.nmol glutamate-1) in the incubation medium quickly reached the level of added [14C]glutamine, but the specific activity of [14C]glutamate in the mitochondria was found to be only 10-15% of that level.

Evidence indicating that pig renal phosphate-activated glutaminase has a functionally predominant external localization in the inner mitochondrial membrane.

Phosphate-activated glutaminase in intact pig renal mitochondria was inhibited 50-70% by the sulfhydryl reagents mersalyl and N-ethylmaleimide (0.3-1.0 mM), when assayed at pH 7.

Effects of mitochondrial swelling and calcium on phosphate-activated glutaminase in pig renal mitochondria.

The effects of mitochondrial swelling and calcium have been used to study the possible function of the glutamine transporter in regulating glutamine hydrolysis. Salt-induced swelling of pig renal mitochondria and an iso-osmotic mixed salt solution and swelling caused by reducing the osmolarity of the incubation medium, are accompanied by activation of glutamine hydrolysis. Regulation of the glutaminase activity by salt-induced mitochondrial swelling is likely to have physiological importance, similar to the regulation of hepatic glutaminase by changing the matrix volume, that has been described by others.

Interrelationship between glutamate and membrane-bound ATPases in nerve cells.

Plasma membrane potential generated by Na+, K(+)-ATPase provides the driving force for high-affinity, Na(+)-dependent uptake of glutamate into the cytoplasm of glutamatergic nerve endings and glial cells. Ca2(+)-calmodulin-dependent ATPase in the plasma membrane and Ca2(+)-ATPase in the endoplasmic reticulum influence the intracellular [Ca2+] and, therefore, the exocytotic release of neurotransmitter glutamate. The membrane potential across the membrane of the synaptic vesicles, generated by a H(+)-ATPase, provides the driving force for synaptic vesicular uptake of glutamate as well as that of GABA and glycine.

Synthesis of transmitter glutamate and the glial-neuron interrelationship.

Glutamate in glutamatergic neurons exists in a cytosolic pool, as well as a transmitter pool, which is assumed to be localized in synaptic vesicles. Transmitter glutamate released from glutamatergic neurons is taken up by both neurons and glial cells, giving rise to a flux of glutamate from neurons to astrocytes. In astrocytes, glutamine is formed from glutamate by the glial-specific enzyme glutamine synthetase (EC 6.