Inadvertent hypothermia in the OR

Hypothermia is one of the most common problems that patients experience in the perioperative environment. Hypothermia causes more problems for the patient than the mere unpleasant experience of feeling cold. Additional nursing interventions are required for a patient suffering from inadvertent hypothermia, which often delays the patient's discharge from the perioperative setting. Many of the nursing interventions that are successful in preventing hypothermia and restoring body heat to surgical patients, such as applying a warmed blanket to a patient's body, seem straightforward. Understanding the cause and effects of inadvertent hypothermia, however, is essential in recognizing it and implementing the most effective nursing interventions.

Specialisation in nursing: are we ready for the year 2000?

The development of specialty nursing practice and nurse specialists in today's health care arena is a controversial yet growing force, fuelled by a complexity of factors from both within and external to the profession. By narrowing the focus on parts of the whole field of nursing, nurses have met the challenge of increasing technology, complexity of the health care system, and nursing care needs. Although the debate regarding nurse specialists continues to rage, the production of such nurses will push beyond the boundaries of the profession into the new millennium, in the interests of patient care.

Development of cadherin-defined parasagittal subdivisions in the embryonic chicken cerebellum

The expression of three cadherins (cadherin-6B, cadherin-7, and R-cadherin) was analyzed by immunohistochemistry at early to intermediate stages of chicken cerebellar development (4.5-12 days of incubation [E4.5-E12]). Expression was first detected at approximately E5. On the cerebellar surface, expression of cadherin-6B and cadherin-7 is initially observed in transverse domains that subsequently elongate into parasagittal stripes. The sequence of emergence, the borders, and the orientation of these expression domains suggest a parcellation of the cerebellum into distinct medial, lateral, and caudal embryonic subdivisions. These subdivisions relate to histologic features, to the expression of gene regulatory proteins, and, possibly, to patterns of clonal restriction. Individual cadherin-expressing cell clusters can be observed to split into cortical and nuclear subdivisions, which are connected by nerve fibers expressing the same cadherin, thus establishing the parasagittal corticonuclear connectivity pattern found at later developmental stages. Our results suggest that cadherins may play a role in the transition from the early embryonic to the later functional organization of the cerebellum by providing a scaffold of potential adhesive cues.

15N investigation into the effect of a pollutant on the nitrogen metabolism of Tetrahymena pyriformis as a model for environmental medical research

A pilot study was performed to examine the potential of stable isotope techniques for monitoring the impact of a harmful substance on the cellular nitrogen metabolism in the ciliate species Tetrahymena pyriformis. After identical cultivation periods of control cells and toluene-exposed cells in a defined culture medium enriched with [guanidino-15N2]l-arginine, a number of nitrogen-containing pools were analyzed: 1) quantity and 15N abundance of ammonia as the end product of nitrogen metabolism in the system; 2) pattern and 15N abundances of the protein-bound amino acids in the cells; 3) pattern and 15N abundances of free amino acids in the cells; and 4) pattern and 15N abundances of the amino acids in the culture medium. In addition to 15N emission spectrometry, a new gas chromatography/combustion interface-isotope ratio mass spectrometry/mass spectrometry analytical system was used. The production and 15N content of ammonia were higher in the toluene-exposed system by 30% and 43%, respectively, indicating higher deamination rates and greater arginine consumption. The toluene-exposed cells exhibited increased 15N abundances of protein-bound amino acids in alanine, aspartic acid, glutamic acid, and tyrosine. Furthermore, structural analyses revealed the presence of N[Omega]-acetylarginine and pyrrolidonecarboxylic acid--compounds that had not previously been detected in Tetrahymena pyriformis. Differences in the 15N-enrichment of free amino acids were also evident. This new effect-monitoring system designed to investigate the impact of a pollutant on protein metabolism by using a stable isotope-labeled cell culture is a powerful tool for environmental medical research.

Cadherin-Defined Segments and Parasagittal Cell Ribbons in the Developing Chicken Cerebellum

In the developing chicken cerebellar cortex, three cadherins (Cad6B, Cad7, and R-cadherin) are expressed in distinct parasagittal segments that are separated from each other by ribbons of migrating interneurons and granule cells which express R-cadherin and Cad7, respectively. The segment/ribbon pattern is respected by the expression of other types of molecules, such as engrailed-2 and SC1/BEN/DM-GRASP. The cadherin-defined segments contain young Purkinje cells which are connected to underlying nuclear zones expressing the same cadherin, thereby forming parasagittal cortico-nuclear zones of topographically organized connections. In addition, R-cadherin-positive mossy fiber terminals display a periodic pattern in the internal granular layer. In this layer, Cad7 and R-cadherin are associated with synaptic complexes. These results suggest that cadherins play a pivotal role in the formation of functional cerebellar architecture by providing a three-dimensional scaffold of adhesive information. Copyright 1998 Academic Press.

Cloning and expression analysis of cadherin-10 in the CNS of the chicken embryo

A full-length cDNA of a novel cadherin of chicken (cad10) was cloned. The deduced amino acid sequence of the putative cytoplasmic domain of this molecule is highly homologous to a previously published cytoplasmic fragment of human cadherin-10, a type II cadherin. An in situ hybridization analysis in chicken embryos shows that cad10 expression starts at about 4 days' incubation (E4) and persists at least until the hatching stage. In the central nervous system (CNS), cad10 expression is spatially restricted at all stages of development. At early stages, expression reflects the neuromeric organization of the brain. For example, in the alar plate of the diencephalon, cad10 expression is restricted to the dorsal thalamic neuromere. A number of cad10-expressing brain nuclei are formed in this neuromeric domain during later development. Specific cad10-expressing gray matter structures are also found in all other major divisions of the brain. Many of these structures are known to be functionally connected to each other. The cad10 expression pattern is distinct from that of other cadherins. These results support the idea that cadherins provide a molecular code for the regionalization of the embryonic CNS at the different stages of development.

Expression of the cell adhesion molecule axonin-1 in neuromeres of the chicken diencephalon

Axonin-1/TAG-1, a member of the immunoglobulin (Ig) superfamily of adhesion molecules, has been shown to be selectively expressed by a subset of neurons and fiber tracts in the developing nervous system of vertebrates. Axonin-1/TAG-1 is thought to play a role in the outgrowth, guidance, and fasciculation of neurites. In the present study, we map the expression of axonin-1 in the diencephalon of the chicken brain at early and intermediate stages of development [2-8 days of incubation; embryonic day (E)2-E8] by immunohistochemical methods. Results show that axonin-1 is first expressed at about E2.5 by postmitotic neurons scattered throughout most of the diencephalon. During the neuromeric stage of brain development (about E3-E5), axonin-1+ nerve cell bodies are predominantly found in two neuromeric subdivisions: 1) in the alar plate of the precommissural pretectum and dorsal thalamus and 2) in the posterior preoptic region of the hypothalamus. The axonin-1+ fiber bundles emerging from these areas grow across segmental boundaries. For example, axonin-1+ neurites originating in the dorsal thalamus cross the zona limitans intrathalamica at a right angle to project to the striatum. Later, the axonin-1+ neuromere areas give rise to particular axonin-1+ gray and white matter structures. Most of these structures correspond to the structures described to express TAG-1 in rodents. In conclusion, axonin-1 can be used as a marker to study aspects of the transition from the early neuromeric structure to the mature anatomy of the chicken brain.

Winning market positioning strategies for long term care facilities

The decision to develop an aggressive marketing strategy for its long term care facility has become a priority for the management of a one-hundred bed facility in the Rocky Mountain West. Financial success and lasting competitiveness require that the facility in question (Deer Haven) establish itself as the preferred provider of long term care for its target market. By performing a marketing communications audit, Deer Haven evaluated its present market position and created a strategy for solidifying and dramatizing this position. After an overview of present conditions in the industry, we offer a seven step process that provides practical guidance for positioning a long term care facility. We conclude by providing an example application.

Restricted expression of R-cadherin by brain nuclei and neural circuits of the developing chicken brain

Cadherins are a family of Ca(2+)-dependent cell-cell adhesion molecules regulating morphogenesis by a preferentially homophilic binding mechanism. We have previously shown that the expression of R-cadherin in the early chicken forebrain (embryonic days E3-E6) is restricted to particular neuromeres or parts of neuromeres. R-cadherin-expressing neuroblasts born in these areas accumulate in the mantle zone and aggregate in particular (pro-) nuclei (Gänzler and Redies [1995] J. Neurosci. 15:4157-4172). In the present study, these findings are extended to later developmental stages (embryonic days E8, E11, and E15). By immunohistochemical and in situ hybridization techniques, we show that, at these stages of development, R-cadherin expression remains restricted to particular developing gray matter regions and fiber tracts. The R-cadherin-positive fiber tracts connect some of the R-cadherin-positive gray matter areas to form parts of particular neural circuits in the visual, auditory, somatosensory, and motor systems. Moreover, R-cadherin expression reflects the morphologic differentiation of gray matter regions. As brain nuclei become morphologically more distinct, the expression of R-cadherin shows a clearer demarcation of the nuclear boundaries. In addition, R-cadherin expression in some nuclei becomes restricted to particular subregions or to clusters of neurons. In the cerebellum, R-cadherin is expressed in parasagittal stripes. These results suggest that R-cadherin expression reflects the functional and morphologic maturation of gray matter structures and of information processing circuits in the embryonic chicken brain.

Implicit rationing criteria in non-small-cell lung cancer treatment

Data collected from lung cancer patients attending the Victoria Clinic of the British Columbia Cancer Agency are used to investigate how resources are rationed in the treatment of non-small-cell lung cancer (NSCLC). An ordered logit model is estimated to analyse empirically the relationship between treatment selection and: tumour stage, size and differentiation; the Feinstein index; Karnofsky performance status (KPS); and the patient's age, gender and marital and smoking status. Implicit rationing is found to occur with respect to all of these factors except the Feinstein index, gender and marital status. With respect to age, KPS and smoker status the main empirical results are: (a) an increase in age from 50 to 85 reduces the expected treatment expenditure by 50-70%, depending on the patient's KPS and smoker status; (b) patients with a KPS less than 80 and of 80, receive 30-46% and 75-85%, respectively, of the expected treatment expenditure for patients with a KPS of 90 or 100, depending on age and smoker status; (c) the expected treatment expenditure for active smokers is about 71-86% of the expenditure for non- or former smokers depending on age and KPS.

Clinical information process units (CIPUs) - a system ergonomic approach to medical information systems

This article constitutes an introduction to the basic tools necessary to understand Systems Ergonomics applied to the development of clinical systems. A basic description of clinical patient care in the system ergonomics language is provided, and the current situation found in hospital information management is criticized from an ergonomic point of view. We have laid out a model of the information flow in the clinical environment, which breaks the complex process of patient care in clearly defined elements: the Clinical Information Process Units. Presented here as an example of the application of Systems Ergonomics to the clinical working processes, the Clinical Information Process Units constitute the central element in the system ergonomic model of the information flow in the clinical environment.

Mechanism of inhibition of hepatic bioactivation of paracetamol by dimethyl sulfoxide

Prior work has shown that DMSO inhibits paracetamol hepatotoxicity. In this paper we show that DMSO and its reduced metabolite dimethyl sulfide (DMS) can inhibit in vitro hepatic dimethylnitrosamine N-demethylase. We also show that DMSO can inhibit in vivo production of glutathione conjugates of paracetamol. Glutathione is known to conjugate the bioactivated form of paracetamol. Also, the isozyme of cytochrome P-450 responsible for dimethylnitrosomine N-demethylase, cytochrome P-450j, is thought responsible for paracetamol bioactivation. We therefore propose that DMSO inhibits paracetamol hepatotoxicity due to inhibition of cytochrome P-450j-dependent paracetamol bioactivation by DMSO and its metabolite DMS.

Drug-induced cutaneous reactions. A report from the Boston Collaborative Drug Surveillance Program on 15,438 consecutive inpatients, 1975 to 1982

We analyzed the data on 15,438 consecutive medical inpatients monitored by the Boston Collaborative Drug Surveillance Program from June 1975 to June 1982 to determine the rates of allergic cutaneous reactions to drugs introduced since 1975 and to confirm and extend findings from an earlier study of the preceding 22,227 patients. There were 358 reactions occurring in 347 patients, for an overall reaction rate among patients of 2.2%. Each patient received a mean of eight different drugs. Rashes were attributed to 51 drugs, and 75% of the allergic cutaneous reactions were attributed to antibiotics, blood products, and inhaled mucolytics. Amoxicillin (51.4 reactions per 1000 patients exposed), trimethoprim-sulfamethoxazole (33.8/1000), and ampicillin (33.2/1000) had the highest reaction rates. Drug-specific reaction rates ranged from zero to 51.4 per 1000 and were determined for 180 drugs or drug groups. These results provide physicians with quantitative data that will be helpful in clinical decision making when drug-induced exanthems, urticaria, or generalized pruritus occurs.

GCN4 protein, a positive transcription factor in yeast, binds general control promoters at all 5' TGACTC 3' sequences

The GCN4 gene is required for the general amino acid control derepression response in yeast. GCN4 protein protects a repeated sequence motif in the 5'-untranslated region of HIS4, HIS3, ILV1, and ILV2 genes subject to general control. At low concentrations of GCN4, only certain repeats in these genes are bound. The repeats differ slightly from the 5' TGACTC 3' consensus core sequence, and the selective binding of some sites at low GCN4 concentrations is related to the relative affinity of these sites to GCN4. Using purified GCN4 protein obtained from an overproducing strain of Escherichia coli, we were able to obtain complete protection of all of the repeat elements in these four genes at high GCN4 concentrations. Analysis of the relative binding constant to the 15 repeated sequences protected by GCN4 shows that the optimal binding site for GCN4 is 5' RRTGACTC 3' followed by a short stretch of thymidines. Another protein, present mostly in yeast nuclear extracts, binds to the HIS4 promoter at a site overlapping one of the GCN4 binding sites. This protein is displaced from its binding site at high GCN4 concentrations.

Lambda phage cro repressor interaction with its operator DNA: 2'-deoxy-5-fluorouracil OR3 analogues

The experiments here show that chemically synthesized DNA containing fluorine at selected sites can be used to test specific predictions of a model for cro repressor--operator interaction. This is done by observation of the perturbation to the fluorine-19 NMR spectra of analogues of OR3 synthesized with 2'-deoxy-5-fluorouracil at specific positions in the DNA helix. Although the three-dimensional structure of the cro repressor from phage lambda has been determined by Matthews and co-workers [Anderson, W., Ohlendorf, D., Takeda, Y., & Matthews, B. (1981) Nature (London) 290, 754-758], direct structural observations on the complex of the protein with its specific DNA recognition sequence, OR3, are limited. From that structure of the protein, alone, a model of its complex to DNA was built by fitting B-form DNA, with some distortion [Ohlendorf, D., Anderson, W., Fisher, R., Takeda, Y., & Matthews, B. (1982) Nature (London) 298, 718-723]. That model proposes that the cro repressor contacts only one side of this DNA double helix and a number of specific protein--DNA contacts. To test the model, 2'-deoxy-5-fluorouracil was used to place the fluorine-19 nuclear spin-label on the side of the DNA contacting the cro repressor and on the opposite side facing away from the cro repressor. The results presented here are consistent with the prediction that lambda phage cro repressor contacts only one side of the DNA double helix.

Correlation of lac operator DNA imino proton exchange kinetics with its function

The kinetics for imino hydrogen exchange, at individual base pairs in the DNA sequence corresponding to the lactose operon operator of Escherichia coli, has been examined by NMR saturation recovery measurements as a function of temperature. Three 17-base-pair subsections of the lac operator DNA were chemically synthesized for these studies. The results support our previous observations in the 36-base-pair complete lac operator DNA fragment that has been used in our previous NMR studies. The results indicate faster opening kinetics at a GTG/CAC that is also the site of operator mutations leading to the highest level of constitutive beta-galactosidase synthesis. The GTG/CAC sequence occurs frequently and often symmetrically in prokaryotic and eukaryotic DNA sites where one anticipates specific protein interaction for gene regulation or recombination.

Possible molecular detent in the DNA structure at regulatory sequences

A common feature that appears in a number of DNA sites where proteins interact is the sequence GTG/CAC. In the lac operator this sequence leads to a region with a higher imino proton exchange rate well below the optical melting temperature. It is suggested that this reflects a structural feature recognized by proteins that bind specific sites on the DNA molecule.