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PubMed2001

Patient puzzle. Use systematic assessment to detect & correct patient conditions.

Medic 27 responds to a report of a fall victim at 27 West Pinnacle Lane. En route, the crew learns from dispatch that the patient fell approximately 25 feet from the roof of a three-story structure onto the roof of an adjacent garage. The caller reports the patient "going in and out of consciousness." The EMS crew requests the dispatch of a rescue unit and ladder company to assist on scene and the placement of a medical helicopter on standby. On scene, the patient's wife reports her husband accidentally disturbed a hornets' nest as he secured a weather vane to the top of the family home. She says the hornets stung her husband repeatedly. In his attempt to avoid the stings, his movements jarred the ladder, causing him to fall to the roof below. As you walk to the side of the patient's home, his wife adds that her husband has a cardiac condition and now complains of chest pain and trouble breathing. You wonder what you'll find when you reach the victim. Is he a medical patient with traumatic injuries or a trauma patient with medical complications?

Accidents, Home↗

PubMed1992

The Hawaii EMS-C project data: I. Reducing pediatric emergency morbidity and mortality; II. Statewide pediatric emergency registry to monitor morbidity and morality.

During a 12-month period ending on 11/30/88, data were collected on 16,010 pediatric patients who visited a pediatric emergency department (ED). These ED patients prospectively fell into one of the target areas for further study, including wheezing (15%), trauma (excluding burns; 29%), burns (1%), water-related injuries (1%), ingestions and toxic substance exposures (2%), child abuse (3%), handicapping conditions (5%), preventable incidents (33%), and ambulance arrivals (7%). Handicapped patients were more likely to require an ambulance. Younger patients, males, and patients with handicaps, wheezing, and Medicaid insurance were more likely to visit the ED on multiple occasions. Primary care physicians could be identified in 77% of the cohort. Large-scale interventions to reduce preventable pediatric morbidity and mortality have suffered from difficulties in documenting their effect in a population-based sample. A statewide pediatric emergency encounter registry is proposed.

Adolescent↗

PubMed2005

Non-acid gastroesophageal reflux: documenting its relationship to symptoms using multichannel intraluminal impedance (MII).

Multichannel intraluminal impedance (MII) is a new technique for evaluating esophageal function and gastroesophageal reflux. This technique depends on changes in resistance to alternating current between two metal electrodes produced by the presence of liquid or gas bolus inside the esophageal lumen. Combined multichannel intraluminal impedance and manometry (MII-EM) provides simultaneous information on intraluminal pressure changes and bolus movement whereas combined multichannel intraluminal impedance and pH (MII-pH) allows detection of gastroesophageal reflux (GER) episodes irrespective of their pH values (i.e. acid and non-acid reflux). Combined MII-pH testing presents a new paradigm for reflux testing. In MII-pH studies reflux events are no longer primarily detected by pH. Refluxate presence, distribution and clearing is primarily detected by MII and simply characterized as acid or non-acid based on pH change and as liquid, gas or mixed based on MII. MII determines refluxate clearance time while pH measures acid clearance time. MII-pH shows promise to become an important clinical tool, particularly to assess GER in the postprandial period and in patients with persistent symptoms on acid suppression therapy.

Adult↗

PubMed2004

Genomic and phylogenic comparisons of the alpha-globin and beta-globin intergenic sequences between zebra fish (Danio rerio) and six closely related Cyprinindae species.

The alpha-globin and beta-globin genes of the zebrafish are tightly linked on the same chromosome in a 3'-5' and 5'-3' configuration, respectively. Although the location of the controlling sequences has been mapped to the intergenic region, analysis determining the uniqueness of this unusual arrangement to zebrafish has not been undertaken. To explore this, we isolated, sequenced, and phylogenetically analyzed the intergenic region between globin gene families of seven Cyprinindae species including zebrafish. These species were grouped into an in group (immediate relatives, not so distant relatives), and an out group (distant relative). Cellulose acetate electrophoresis of hemoglobin (Hb) detected multiple variants in each species, but a band with electrophoretic mobility (EM) of 6.7 x 10(-5) cm(2).volt(-1).sec(-1) was shared between species. Polymerase chain reaction (PCR) amplification of the intergenic globin gene region also detected a 1.0-kb fragment that was repeated in the in group and a 1.2-kb fragment in the out group. Sequence comparison confirmed that the genetic orientation and controlling sequences location were conserved throughout this region in all seven species. This phylogenic footprinting indicated that the configuration was not exclusive to zebrafish. To confirm sequence alignment, maximum parsimony phylogenic analysis, was performed. Only one member of that group the giant danio, was not closely clustered, being located almost equidistance between the immediate relative and the species of the other clusters. This may represent an ancestral configuration prior to transposition of the alpha globin and beta-globin genes families to nonsynteny.

Algorithms↗

PubMed2003

Sulphoxidation of ethyl methyl sulphide, 4-chlorophenyl methyl sulphide and diphenyl sulphide by purified pig liver flavin-containing monooxygenase.

1. The biotransformation of ethyl methyl sulphide (EMS), 4-chlorophenyl methyl sulphide (CPMS) and diphenyl sulphide (DPS) to their corresponding sulphoxides by purified flavin-containing monooxygenase (FMO) is described. 2. Purified pig liver flavin-containing monooxygenase catalysed the sulphoxidation of EMS, CPMS and DPS to their corresponding sulphoxides and the reactions followed single enzyme Michelis-Menten kinetics. 3. The apparent K(m) and V(max) for the sulphoxidation of EMS were 1.38+/-0.05 mM and 78.74+/-3.9 nmoles mg(-1) protein min(-1), respectively. The apparent K(m) and V(max) for the sulphoxidation of CPMS were 0.185+/-0.03 mM and 103+/-5.0 nmoles mg(-1) protein min(-1), respectively. The apparent K(m) and V(max) for the sulphoxidation of DPS were 0.068+/-0.002 mM and 49.26+/-2.05 nmoles mg(-1) protein min(-1), respectively. 4. A significant reduction of the sulphoxidation of these simple sulphides was observed with addition of 1-naphthylthiourea in the incubation medium. On the other hand, incorporation of catalase and superoxide dismutase into the incubation media produced no appreciable inhibition of the observed sulphoxidation of the sulphides. 5. These results suggest that FMO is responsible, at least in part, for the sulphoxidation of nucleophilic sulphides as well as for the oxidation of sulphur atoms that reside within or adjacent to aromatic systems.

Algorithms↗

PubMed2005

Fast 3D-EM reconstruction using Planograms for stationary planar positron emission mammography camera.

At the University of Pisa we are building a PEM prototype, the YAP-PEM camera, consisting of two opposite 6 x 6 x 3 cm3 detector heads of 30 x 30 YAP:Ce finger crystals, 2 x 2 x 30 mm3 each. The camera will be equipped with breast compressors. The acquisition will be stationary. Compared with a whole body PET scanner, a planar Positron Emission Mammography (PEM) camera allows a better, easier and more flexible positioning around the breast in the vicinity of the tumor: this increases the sensitivity and solid angle coverage, and reduces cost. To avoid software rejection of data during the reconstruction, resulting in a reduced sensitivity, we adopted a 3D-EM reconstruction which uses all of the collected Lines Of Response (LORs). This skips the PSF distortion given by data rebinning procedures and/or Fourier methods. The traditional 3D-EM reconstruction requires several times the computation of the LOR-voxel correlation matrix, or probability matrix {p(ij)}; therefore is highly time-consuming. We use the sparse and symmetry properties of the matrix {p(ij)} to perform fast 3D-EM reconstruction. Geometrically, a 3D grid of cubic voxels (FOV) is crossed by several divergent 3D line sets (LORs). The symmetries occur when tracing different LORs produces the same p(ij) value. Parallel LORs of different sets cross the FOV in the same way, and the repetition of p(ij) values depends on the ratio between the tube and voxel sizes. By optimizing this ratio, the occurrence of symmetries is increased. We identify a nucleus of symmetry of LORs: for each set of symmetrical LORs we choose just one LOR to be put in the nucleus, while the others lie outside. All of the possible p(ij) values are obtainable by tracking only the LORs of this nucleus. The coordinates of the voxels of all of the other LORs are given by means of simple translation rules. Before making the reconstruction, we trace the LORs of the nucleus to find the intersecting voxels, whose p(ij) values are computed and stored with their voxel coordinates on a hard disk. Only the non-zero p(ij) are considered and their computation is performed just once. During the reconstruction, the stored values are loaded and are available in the random access memory for all of the operations of normalization, backprojection and projection: these are now performed rapidly, because the application of the translation rules is much faster than the probability computations. We tested the algorithm on Monte Carlo data fully simulating the typical YAP-PEM clinical condition. The adopted algorithm gives an excellent positioning capability for hot spots in the camera FOV. To use all of the possible skew LORs in the FOV avoids the software rejection of collected data. Reconstructed images indicate that a 5mm diameter tumor of 37 kBq/cm3, in an active breast with a 10:1 Tissue to Background ratio (T/B), with a 10 min acquisition, for a head distance of 5 cm, can be detected by the YAP-PEM with a SNR of 8.7+/-1.0. The obtained SNR values depend linearly on the tumor volume. The algorithm allows one to discriminate between two hot sources of 5.0 mm diameter if they do not lie on the same axis. The YAP-PEM is now in the assembly stage.

Algorithms↗

PubMed2002

A Monte Carlo EM approach for partially observable diffusion processes: theory and applications to neural networks.

We present a Monte Carlo approach for training partially observable diffusion processes. We apply the approach to diffusion networks, a stochastic version of continuous recurrent neural networks. The approach is aimed at learning probability distributions of continuous paths, not just expected values. Interestingly, the relevant activation statistics used by the learning rule presented here are inner products in the Hilbert space of square integrable functions. These inner products can be computed using Hebbian operations and do not require backpropagation of error signals. Moreover, standard kernel methods could potentially be applied to compute such inner products. We propose that the main reason that recurrent neural networks have not worked well in engineering applications (e.g., speech recognition) is that they implicitly rely on a very simplistic likelihood model. The diffusion network approach proposed here is much richer and may open new avenues for applications of recurrent neural networks. We present some analysis and simulations to support this view. Very encouraging results were obtained on a visual speech recognition task in which neural networks outperformed hidden Markov models.

Algorithms↗

PubMed2002

Energy-based reconstruction of a protein backbone from its alpha-carbon trace by a Monte-Carlo method.

An automatic procedure is proposed for reconstruction of a protein backbone from its C(alpha)-trace; it is based on optimization of a simplified energy function of a peptide backbone, given its alpha-carbon trace. The energy is expressed as a sum of the energies of interaction between backbone peptide groups that are not neighbors in the sequence, the energies of local interactions within all amino acid residues, and a harmonic penalty function accounting for the conservation of standard bond angles. The energy of peptide group interactions is calculated using the assumption that each peptide group acts as a point dipole. For local interaction energy, use is made of a two-dimensional Fourier series expansion of the energies of model terminally blocked amino acid residues, calculated with the Empirical Conformational Energy Program for Peptides (ECEPP/3) force field in the angles lambda((1)) and lambda((2)) defining the rotation of peptide groups adjacent to a C(alpha) carbon atom about the corresponding C(alpha) em leader C(alpha) virtual-bond axes. To explore all possible rotations of peptide groups within a fixed C(alpha)-trace, a Monte Carlo search is carried out. The initial lambda angles are calculated by aligning the dipoles of the peptide groups that are close in space, subject to the condition of favorable local interactions. After the Monte Carlo search is accomplished with the simplified energy function, the energy of the structure is minimized with the ECEPP/3 force field, with imposition of distance constraints corresponding to the initial C(alpha)-trace geometry. The procedure was tested on model alpha-helices and beta-sheets, as well as on the crystal structure of the immunoglobulin binding protein (PDB code: 1IGD, an alpha/beta protein). In all cases, complete backbone geometry was reconstructed with a root-mean-square (rms) deviation of 0.5 A from the all-atom target structure.

Algorithms↗

PubMed2005

Determining protein topology from skeletons of secondary structures.

We report a novel computational procedure for determining protein native topology, or fold, by defining loop connectivity based on skeletons of secondary structures that can usually be obtained from low to intermediate-resolution density maps. The procedure primarily involves a knowledge-based geometry filter followed by an energetics-based evaluation. It was tested on a large set of skeletons covering a wide range of protein architecture, including one modeled from an experimentally determined 7.6A cryo-electron microscopy (cryo-EM) density map. The results showed that the new procedure could effectively deduce protein folds without high-resolution structural data, a feature that could also be used to recognize native fold in structure prediction and to interpret data in fields like structure genomics. Most importantly, in the energetics-based evaluation, it was revealed that, despite the inevitable errors in the artificially constructed structures and limited accuracy of knowledge-based potential functions, the average energy of an ensemble of structures with slightly different configurations around the native skeleton is a much more robust parameter for marking native topology than the energy of individual structures in the ensemble. This result implies that, among all the possible topology candidates for a given skeleton, evolution has selected the native topology as the one that can accommodate the largest structural variations, not the one rigidly trapped in a deep, but narrow, conformational energy well.

Algorithms↗

PubMed2002

O-Dealkylation of fluoxetine in relation to CYP2C19 gene dose and involvement of CYP3A4 in human liver microsomes.

This work evaluated the kinetic behavior of fluoxetine O-dealkylation in human liver microsomes from different CYP2C19 genotypes and identified the isoenzymes of cytochrome P450 involved in this metabolic pathway. The kinetics of the rho-trifluoromethylphenol (TFMP) formation from fluoxetine was determined in human liver microsomes from three homozygous (wt/wt) and three heterozygous (wt/m1) extensive metabolizers (EMs) and three poor metabolizers (PMs) with m1 mutation (m1/m1) with respect to CYP2C19. The formation rate of TFMP was determined by gas chromatograph with electron-capture detection. The kinetics of TFMP formation was best described by the two-enzyme and single-enzyme Michaelis-Menten equation for liver microsomes from CYP2C19 EMs and PMs, respectively. The mean intrinsic clearance (V(max)/K(m)) for the high- and low-affinity component was 25.2 microl/min/nmol and 3.8 microl/min/nmol of cytochrome P450 in the homozygous EMs microsomes and 12.8 microl/min/nmol and 2.9 microl/min/nmol of cytochrome P450 in the heterozygous EMs microsomes, respectively. Omeprazole (a CYP2C19 substrate) at a high concentration and triacetyloleandomycin (a selective inhibitor of CYP3A4) substantially inhibited O-dealkylation of fluoxetine. Furthermore, fluoxetine O-dealkylation was correlated significantly with S-mephenytoin 4'-hydroxylation at a low substrate concentration and midazolam 1'-hydroxylation at a high substrate concentration in liver microsomes of 11 Chinese individuals, respectively. Moreover, there were obvious differences in the O-dealkylation of fluoxetine in liver microsomes from different CYP2C19 genotypes and in microsomal fractions of different human-expressed lymphoblast P450s. The results demonstrated that polymorphic CYP2C19 and CYP3A4 enzymes were the major cytochrome P450 isoforms responsible for fluoxetine O-dealkylation, whereas CYP2C19 catalyzed the high-affinity O-dealkylation of fluoxetine, and its contribution to this metabolic reaction was gene dose-dependent.

Algorithms↗

PubMedDate not supplied

Detecting circular and rectangular particles based on geometric feature detection in electron micrographs.

Accurate and automatic particle detection from cryo-electron microscopy (cryo-EM images) is very important for high-resolution reconstruction of large macromolecular structures. In this paper, we present a method for particle picking based on shape feature detection. Two fundamental concepts of computational geometry, namely, the distance transform and the Voronoi diagram, are used for detection of critical features as well as for accurate location of particles from the images or micrographs. Unlike the conventional template-matching methods, our approach detects the particles based on their boundary features instead of intensities. The geometric features derived from the boundaries provide an efficient way for locating particles quickly and accurately, which avoids a brute-force searching for the best position/orientation. Our approach is fully automatic and has been successfully applied to detect particles with approximately circular or rectangular shapes (e.g., KLH particles). Particle detection can be enhanced by multiple sets of parameters used in edge detection and/or by anisotropic filtering. We also discuss the extension of this approach to other types of particles with certain geometric features.

Algorithms↗

PubMed2006

Time to give the first medication during resuscitation in out-of-hospital cardiac arrest.

OBJECTIVE: There is no evidence showing an impact from any advanced cardiac life support (ACLS) medications on patient survival following cardiac arrest. One potential reason for a lack of such benefit may be medication timing. We formed the hypothesis that medications are given late after rescuer arrival, limiting any benefit. We performed a meta-analysis to determine the time from emergency medical services (EMS) dispatch to first medication administration, regardless of route, during out-of-hospital cardiac arrest (OOHCA). Then, the mean time and ranges of reported study medication delivery in clinical trials where medication was the experimental intervention was determined. METHODS: We conducted a comprehensive literature review between January 1990 and August 2005 in MEDLINE using the following MeSH headings: cardiopulmonary resuscitation, cardiac arrest, heart arrest, EMS, EMT, ambulance, and the names of all ACLS medications. We reviewed the abstracts of 632 studies and full manuscripts of 248 published papers. We eliminated the following articles from further analysis: non-peer reviewed; all without human primary data (includes review articles, guidelines or consensus manuscripts, editorials, or simulation studies); animal data; case reports. We used no language restriction. From this search, our independent reviewers found 17 papers that contained information on time to medication administration. RESULTS: We analyzed reporting of drug delivery time to 7617 patients in 32 different emergency medical services systems. Time to first medication delivery by any route was a mean of 17.7 min (range 10.0-25.0; 95% CI around mean 10.6, 24.8). Time to intravenous experimental medication administration was a mean of 19.4 min (range 13.3-25.0; 95% CI around mean 12.8, 25.9). CONCLUSIONS: Medications are given late during out-of-hospital cardiac arrest, even in cohorts where drug delivery is a key study intervention.

Algorithms↗

PubMed2005

Brain SPECT with short focal-length cone-beam collimation.

Single-photon emission-computed tomography (SPECT) imaging of deep brain structures is compromised by loss of photons due to attenuation. We have previously shown that a centrally peaked collimator sensitivity function can compensate for this phenomenon, increasing sensitivity over most of the brain. For dual-head instruments, parallel-hole collimators cannot provide variable sensitivity without simultaneously degrading spatial resolution near the center of the brain; this suggests the use of converging collimators. We have designed collimator pairs for dual-head SPECT systems to increase sensitivity, particularly in the center of the brain, and compared the new collimation approach to existing approaches on the basis of performance in estimating activity concentration of small structures at various locations in the brain. The collimator pairs we evaluated included a cone-beam collimator, for increased sensitivity, and a fan-beam collimator, for data sufficiency. We calculated projections of an ellipsoidal uniform background, with 0.9-cm-radius spherical lesions at several locations in the background. From these, we determined ideal signal-to-noise ratios (SNRCRB) for estimation of activity concentration within the spheres, based on the Cramer-Rao lower bound on variance. We also reconstructed, by an ordered-subset expectation-maximization (OS-EM) procedure, images of this phantom, as well as of the Zubal brain phantom, to allow visual assessment and to ensure that they were free of artifacts. The best of the collimator pairs evaluated comprised a cone-beam collimator with 20 cm focal length, for which the focal point is inside the brain, and a fan-beam collimator with 40 cm focal length. This pair yielded increased SNRCRB, compared to the parallel-parallel pair, throughout the imaging volume. The factor by which SNRCRB increased ranged from 1.1 at the most axially extreme location to 3.5 at the center. The gains in SNRCRB were relatively robust to mismatches between the center of the brain and the center of the imaging volume. Artifact-free reconstructions of simulated data acquired using this pair were obtained. Combining fan-beam and short-focusing cone-beam collimation should greatly improve dual-head brain SPECT imaging, especially for centrally located structures.

Algorithms↗

PubMed1996

A new decision rule for parameter delta in MAP EM (OSL) reconstruction with the Gibbs prior.

In MAP EM (OSL) reconstruction with the Gibbs prior, the parameter delta which appears in the prior is commonly treated as a fixed value. Because the quality of reconstructed images depends on this parameter, we have to select delta very carefully, and because the statistics of an image vary locally, we should not choose a single delta value for each image. We propose a new decision rule to select an appropriate local delta. In our proposed method, delta is determined as the median of the differences between a value of the pixel of interest and those of neighboring pixels. This selection yields an appropriate prior depending on the regional statistics. The prior therefore preserves the edge property without amplifying statistical noise and it is not necessary to know the appropriate delta value to obtain high quality images. We performed computer simulations to determine the effectiveness of the proposed method. The results showed that the quality of reconstructed images obtained with the proposed method was superior to those obtained with the prior with a fixed delta.

Algorithms↗

PubMed2004

Ethnicity-independent genetic basis of functional psychoses: a genotype-to-phenotype approach.

The functional psychoses schizophrenia, schizoaffective disorder, and bipolar illness represent complex clinical syndromes that are characterized by phenotypic heterogeneity. Yet evidence from numerous studies suggests that (1) the prevalence of schizophrenia and bipolar illness is with 1% very similar across ethnicities, and (2) a strong genetic component is involved in the disorders' pathogenesis. Using data from different US-American ethnicities (77 families with a total of 17 unaffected and 170 affected sib pairs; 276 marker loci), we searched for ethnicity-independent oligogenic susceptibility loci for which the between-sib genetic similarity in affected sib pairs deviated from the expected values. Specifically, we addressed the question of the extent to which genetic risk factors and their interactions constitute multigenic inheritance of functional psychoses across populations and might constitute universal targets for treatment. Our novel multivariate genotype-to-phenotype search strategy was based on a genetic similarity function that allowed us to quantify the inter-individual genetic distances d(x(i), x(j)) between the allelic genotype patterns x(i), x(j) of any two subjects i, j with respect to n loci l(1), l(2), em leader l(n). Thus, we were able to assess the between-ethnicity, the within-ethnicity, and the within-family genetic similarities. The problem of ethnicity-independent vulnerability was addressed by treating the Afro-American families as "training" samples, while the non-Afro-American families served as independent "test" samples. We evaluated the between-sib similarities, which were expected to deviate from "0.5" in affected sib pairs if the region of interest contained markers close to vulnerability genes. The reference value "0.5" was derived from the parent-offspring similarities that are always 0.5, irrespective of the affection status of parents and offspring. We found 12 vulnerability loci on chromosomes 1, 4, 5, 6, 13, 14, 18, and 20, that were reproducible across the two samples under comparison and therefore, likely to constitute an ethnicity-independent, oligogenic vulnerability model of functional psychoses. The elevated vulnerability appeared to be unspecific and to act in such a way that exogenous factors become more likely to trigger the onset of psychiatric illnesses.

Algorithms↗

PubMed1999

Modelling the changes due to the endothelium and hypertension in the alpha-adrenoreceptor-mediated responses of rat aorta.

The present study focuses on the role of endothelium on alpha1-adrenoceptor-mediated vasoconstriction in aorta from Wistar Kyoto (WKY) and spontaneously hypertensive rats (SHR). To define and quantify changes in the parameters governing agonism at alpha1-adrenoceptor by hypertension and/or endothelium, the operational model of analysis was used. In either endothelium intact or denuded aorta, the sensitivity (P < 0.001) and the maximum contraction (P < 0.05) to phenylephrine were smaller in SHR than in WKY. However, in each strain of rats, removal of endothelium increased the sensitivity (P < 0.001) to phenylephrine but reduced (P < 0.05) KCl-evoked vasoconstriction, suggesting a modulation of these responses by the endothelium. The observed differences in sensitivity and maximum contraction are interpreted in terms of the operational parameters: Em, the maximum possible effect; pK(A), the agonist affinity; alpha, the agonist efficacy and n, the slope for the function relating receptor occupancy to pharmacological effect. The estimated parameters reflected differences, between strains, in the signal transduction processes linked to alpha1-adrenoceptor stimulation ascribed to the presence of the endothelium. N(G)-nitro-L-arginine methyl ester (L-NAME), enhanced to a similar extend in both rat strains the sensitivity (P < 0.001) and the maximum contraction to phenylephrine. Indomethacin reduced the maximum contraction to phenylephrine by 56.85% in SHR and by 11.80% in WKY suggesting that contracting prostanoids play a more major role in this response in SHR than in WKY. Nevertheless, these inhibitors were without effect on denuded vessels from both strains suggesting that NO and cyclooxygenase products from the media or the adventitia do not play a role on the phenylephrine-mediated responses. The studied endothelial factors partially explain the observed differences in modulation of alpha1-adrenoceptor responses by the endothelium but suggest the participation of other compounds released by the endothelium.

Adrenergic alpha-Agonists↗

PubMed1989

Electrical and mechanical responses of rat saphenous vein to short-term pressure load.

The magnitude and mechanism of myogenic response of vascular smooth muscle (SM) in rat distal saphenous vein was assessed from SM membrane potential (Em) measured in situ and in vitro with glass microelectrodes and from active and passive stress and strain calculated from changes in vessel diameter measured in vitro via videomicroscopy. Elevation of intraluminal pressure from 2.2 +/- 0.2 (SE) mmHg (control) to 15 +/- 0.8 mmHg for 1 h in a series of in vitro vessel segments perfused with physiological salt solution at 0.2 ml/min induced a maintained and reversible depolarization of 18 +/- 0.9 mV. A 7.6 +/- 0.4-mmHg pressure increase induced a 12.9 +/- 1.2-mV depolarization in a second series. In a third series, 5-mmHg pressure increments induced significant increments in active isometric stress and isobaric strain. Opening an acute, reversible in situ femoral artery to saphenous vein shunt caused a 4- to 5-mmHg venous pressure elevation, a 10-fold increase in venous blood flow, and a 12.1 +/- 0.9-mV venous SM depolarization. Thus a short-term pressure load causes sustained, reversible venous SM cell depolarization both in vitro and in situ, coupled with active strain and stress generation in the vein wall. These results support our hypothesis that SM of peripheral veins can contribute to an intrinsic capacity autoregulation.

Algorithms↗

PubMedDate not supplied

Evaluation of a new EMS asthma protocol in New York City: a preliminary report.

BACKGROUND: In July 1996, the New York City (NYC) regional EMS implemented a new protocol whereby EMS personnel in the prehospital setting could administer 125 mg of intravenous methyl prednisolone to asthma patients as one of their medical options following telephone consultation with a medical control physician. OBJECTIVE: To determine whether this protocol had any effect on hospital admission rates or the emergency department (ED) length of stay. METHODS: This retrospective chart review focused on the 219 (of 603 total) patients who arrived to the ED by ambulance over a two-year period whose ED diagnosis was asthma. There were 81 patient encounters in year 1, and 138 in year 2. Eleven of the year 2 group received prehospital steroids. The study took place at an urban 911 receiving, Level 2 ED. RESULTS: Of the group who received prehospital steroids, none resulted in hospital admission. Due to the small sample size in the steroid-receiving group, the differences in these admission rates are not yet significant. No differences were detected in the ED length of stay between the two patient groups (157 vs. 160 minutes in year 2, p = 0.9). CONCLUSION: The differences in admission rates suggested by this study suggest a simple yet potentially powerful tool for improving patient outcome in the treatment of asthma.

Acute Disease↗