Older people presenting to the emergency department after a fall: a population with substantial recurrent healthcare use

ABSTRACT Objectives To document patient characteristics, care pathways, healthcare use and costs of fall-related emergency department (ED) presentations by older adults. Participants and methods All fallers aged $70 years, presenting to the ED of a 450-bed metropolitan university hospital in Sydney, Australia (1 April 2007 through 31 March 2009) were studied. Data were collected from the ED electronic information system, ED clinical records and the hospital electronic information system database. Population estimates for 2008 for the local areas served by the hospital were used to estimate ED presentation rates. Results Of 18 902 all-cause ED presentations, 3220 (17.0%) were due to a fall. Among fallers, 35.4% had one or more ED presentations and 20.3% had had one or more hospital admissions in the preceding 12 months. Fall-related ED presentation led directly to hospital admission in 42.7% of the cases, the majority of which (78.0%) received acute care only (length of stayd14.4 days for men and 13.7 days for women) and the remaining cases underwent further inpatient rehabilitation (length of stay 35.6 days for men and 3

Trail width and epiphyllous coverage of Chamaedorea spp

Epiphylls are bryophytes and lichens that grow on the leaves of other trees. These plants are dependent on water for survival and reproduction. Lichens are often used as bioindicators of climate change and pollution. The purpose of this study was to find out if trail width sufficiently changed the microclimate and altered epiphyll cover on trailside leaves. I hypothesized that epiphylls could be used as bioindicators of changing microclimate by trails from a control area. Liverwort and lichen cover were measured on leaves of Chamaedorea spp. (Arecaceae) in the Monteverde Biological Cloud Forest Preserve on five different trail types. Wider trails had decreased epiphyllous growth compared to narrower trails, with reductions of 82% to 89% on wide trails and 28% reductions on narrow trails. Epiphylls have shown that they can be used as bioindicators of small changes in sunlight due to trail widths. Epiphyll cover is declining linearly with trail widths. These effects can be warning signs for others plants that are harder to examine effects on. Las epífilas son briófitas y líquenes que crecen en las hojas de otros árboles. Estas plantas dependen del agua para su supervivencia y reproducción. Los líquenes son utilizados con frecuencia como bioindicadores de cambio climático y contaminación. El propósito de este estudio fue determinar si la amplitud de los senderos cambia el microclima y altera la cubierta de epífilas en las hojas a la orilla del sendero. Se propuso la hipótesis de que las epífilas briofíticas como los líquenes se podrían utilizar como bioindicadores de cambios en el microclima de los senderos en un área de control. Se determinó el porcentaje de cubierta de las hepáticas y líquenes en Chamaedorea spp. (Arecaceae) en la Reserva Biológica Bosque Nuboso de Monteverde, en cinco categorías diferentes de senderos. Se demostró que los senderos más anchos disminuyeron el crecimiento de epífilas más que los senderos más estrechos, con reducciones del 82% al 89% en senderos amplios. Se demostró que las epífilas pueden ser utilizadas como bioindicadores de cambios pequeños en la luz solar debido a la anchura del sendero.https://digitalcommons.usf.edu/tropical_ecology/1597/thumbnail.jp

Trail width and epiphyllous coverage of Chamaedorea spp

Epiphylls are bryophytes and lichens that grow on the leaves of other trees. These plants are dependent on water for survival and reproduction. Lichens are often used as bioindicators of climate change and pollution. The purpose of this study was to find out if trail width sufficiently changed the microclimate and altered epiphyll cover on trailside leaves. I hypothesized that epiphylls could be used as bioindicators of changing microclimate by trails from a control area. Liverwort and lichen cover were measured on leaves of Chamaedorea spp. (Arecaceae) in the Monteverde Biological Cloud Forest Preserve on five different trail types. Wider trails had decreased epiphyllous growth compared to narrower trails, with reductions of 82% to 89% on wide trails and 28% reductions on narrow trails. Epiphylls have shown that they can be used as bioindicators of small changes in sunlight due to trail widths. Epiphyll cover is declining linearly with trail widths. These effects can be warning signs for others plants that are harder to examine effects on. Las epífilas son briófitas y líquenes que crecen en las hojas de otros árboles. Estas plantas dependen del agua para su supervivencia y reproducción. Los líquenes son utilizados con frecuencia como bioindicadores de cambio climático y contaminación. El propósito de este estudio fue determinar si la amplitud de los senderos cambia el microclima y altera la cubierta de epífilas en las hojas a la orilla del sendero. Se propuso la hipótesis de que las epífilas briofíticas como los líquenes se podrían utilizar como bioindicadores de cambios en el microclima de los senderos en un área de control. Se determinó el porcentaje de cubierta de las hepáticas y líquenes en Chamaedorea spp. (Arecaceae) en la Reserva Biológica Bosque Nuboso de Monteverde, en cinco categorías diferentes de senderos. Se demostró que los senderos más anchos disminuyeron el crecimiento de epífilas más que los senderos más estrechos, con reducciones del 82% al 89% en senderos amplios. Se demostró que las epífilas pueden ser utilizadas como bioindicadores de cambios pequeños en la luz solar debido a la anchura del sendero.https://digitalcommons.usf.edu/tropical_ecology/1597/thumbnail.jp

Imine reductases : a comparison of glutamate dehydrogenase to ketimine reductases in the brain

A key intermediate in the glutamate dehydrogenase (GDH)-catalyzed reaction is an imine. Mechanistically, therefore, GDH exhibits similarities to the ketimine reductases. In the current review, we briefly discuss (a) the metabolic importance of the GDH reaction in liver and brain, (b) the mechanistic similarities between GDH and the ketimine reductases, (c) the metabolic importance of the brain ketimine reductases, and (d) the neurochemical consequences of defective ketimine reductases. Our review contains many historical references to the early work on amino acid metabolism. This work tends to be overlooked nowadays, but is crucial for a contemporary understanding of the central importance of ketimines in nitrogen and intermediary metabolism. The ketimine reductases are important enzymes linking nitrogen flow among several key amino acids, yet have been little studied. The cerebral importance of the ketimine reductases is an area of biomedical research that deserves far more attention.15 page(s

Lysine metabolism in mammalian brain : an update on the importance of recent discoveries

The lysine catabolism pathway differs in adult mammalian brain from that in extracerebral tissues. The saccharopine pathway is the predominant lysine degradative pathway in extracerebral tissues, whereas the pipecolate pathway predominates in adult brain. The two pathways converge at the level of ∆¹-piperideine-6-carboxylate (P6C), which is in equilibrium with its open-chain aldehyde form, namely, α-aminoadipate δ-semialdehyde (AAS). A unique feature of the pipecolate pathway is the formation of the cyclic ketimine intermediate ∆¹-piperideine-2- carboxylate (P2C) and its reduced metabolite l-pipecolate. A cerebral ketimine reductase (KR) has recently been identified that catalyzes the reduction of P2C to l-pipecolate. The discovery that this KR, which is capable of reducing not only P2C but also other cyclic imines, is identical to a previously well-described thyroid hormone-binding protein [μ-crystallin (CRYM)], may hold the key to understanding the biological relevance of the pipecolate pathway and its importance in the brain. The finding that the KR activity of CRYM is strongly inhibited by the thyroid hormone 3,5,3'-triiodothyronine (T₃) has far-reaching biomedical and clinical implications. The inter-relationship between tryptophan and lysine catabolic pathways is discussed in the context of shared degradative enzymes and also potential regulation by thyroid hormones. This review traces the discoveries of enzymes involved in lysine metabolism in mammalian brain. However, there still remain unanswered questions as regards the importance of the pipecolate pathway in normal or diseased brain, including the nature of the first step in the pathway and the relationship of the pipecolate pathway to the tryptophan degradation pathway.24 page(s

Insights into enzyme catalysis and thyroid hormone regulation of cerebral ketimine reductase/μ-crystallin under physiological conditions

Mammalian ketimine reductase is identical to μ-crystallin (CRYM)—a protein that is also an important thyroid hormone binding protein. This dual functionality implies a role for thyroid hormones in ketimine reductase regulation and also a reciprocal role for enzyme catalysis in thyroid hormone bioavailability. In this research we demonstrate potent sub-nanomolar inhibition of enzyme catalysis at neutral pH by the thyroid hormones l-thyroxine and 3,5,3′-triiodothyronine, whereas other thyroid hormone analogues were shown to be far weaker inhibitors. We also investigated (a) enzyme inhibition by the substrate analogues pyrrole-2-carboxylate, 4,5-dibromopyrrole-2-carboxylate and picolinate, and (b) enzyme catalysis at neutral pH of the cyclic ketimines S-(2-aminoethyl)-l-cysteine ketimine (owing to the complex nomenclature trivial names are used for the sulfur-containing cyclic ketimines as per the original authors’ descriptions) (AECK), Δ¹-piperideine-2-carboxylate (P2C), Δ¹-pyrroline-2-carboxylate (Pyr2C) and Δ²-thiazoline-2-carboxylate. Kinetic data obtained at neutral pH suggests that ketimine reductase/CRYM plays a major role as a P2C/Pyr2C reductase and that AECK is not a major substrate at this pH. Thus, ketimine reductase is a key enzyme in the pipecolate pathway, which is the main lysine degradation pathway in the brain. In silico docking of various ligands into the active site of the X-ray structure of the enzyme suggests an unusual catalytic mechanism involving an arginine residue as a proton donor. Given the critical importance of thyroid hormones in brain function this research further expands on our knowledge of the connection between amino acid metabolism and regulation of thyroid hormone levels.15 page(s

Ketimine reductase/CRYM catalyzes reductive alkylamination of α-keto acids, confirming its function as an imine reductase

Recently, crystalized mouse ketimine reductase/CRYM complexed with NADPH was found to have pyruvate bound in its active site. We demonstrate that the enzyme binds α-keto acids, such as pyruvate, in solution, and catalyzes the formation of N-alkyl-amino acids from alkylamines and α-keto acids (via reduction of imine intermediates), but at concentrations of these compounds not expected to be encountered in vivo. These findings confirm that, mechanistically, ketimine reductase/CRYM acts as a classical imine reductase and may explain the finding of bound pyruvate in the crystallized protein.5 page(s

Mammalian forebrain ketimine reductase identified as μ-crystallin; potential regulation by thyroid hormones

Ketimine reductase (E.C. 1.5.1.25) was purified to apparent homogeneity from lamb forebrain by means of a rapid multi-step chromatography protocol. The purified enzyme was identified by MS/MS (mass spectrometry) as μ-crystallin. The identity was confirmed by heterologously expressing human μ-crystallin in Escherichia coli and subsequent chromatographic purification of the protein. The purified human μ-crystallin was confirmed to have ketimine reductase activity with a maximum specific activity similar to that of native ovine ketimine reductase, and was found to catalyse a sequential reaction. The enzyme substrates are putative neuromodulator/transmitters. The thyroid hormone 3,5,3′-l-triiodothyronine (T3) was found to be a strong reversible competitive inhibitor, and may have a novel role in regulating their concentrations. μ-Crystallin is also involved in intracellular T3 storage and transport. This research is the first to demonstrate an enzyme function for μ-crystallin. This newly demonstrated enzymatic activity identifies a new role for thyroid hormones in regulating mammalian amino acid metabolism, and a possible reciprocal role of enzyme activity regulating bioavailability of intracellular T3.9 page(s