Characteristics of jugular bulb oxygen saturation in patients after cardiac arrest: A prospective study.

BACKGROUND: Using cerebral oxygen venous saturation post-cardiac arrest (CA) is limited because of a small sample size and prior to establishment of target temperature management (TTM). We aimed to describe variations in jugular bulb oxygen saturation during intensive care in relation to neurological outcome at 6 months post- CA in cases where TTM 33°C was applied. METHOD: Prospective observational study in patients over 18 years, comatose immediately after resuscitation from CA. Patients were treated with TTM 33°C M and received a jugular bulb catheter within the first 26 hours post-CA. Neurological outcome was assessed at 6 months using the Cerebral Performance Categories (CPC) and dichotomized into good (CPC 1-2) and poor outcome (CPC 3-5). RESULTS: Seventy-five patients were included and 37 (49%) patients survived with a good outcome at 6 months post-CA. No differences were found between patients with good outcome and poor outcome in jugular bulb oxygen saturation. Higher values were seen in differences in oxygen content between central venous oxygen saturation and jugular bulb oxygen saturation in patients with good outcome compared to patients with poor outcome at 6 hours (12 [8-21] vs 5 [-0.3 to 11]% P = .001) post-CA. Oxygen extraction fraction from the brain illustrated lower values in patients with poor outcome compared to patients with good outcome at 96 hours (14 [9-23] vs 31 [25-34]% P = .008). CONCLUSIONS: Oxygen delivery and extraction differed in patients with a good outcome compared to those with a poor outcome at single time points. Based on the present findings, the usefulness of jugular bulb oxygen saturation for prognostic purposes is uncertain in patients treated with TTM 33°C post-CA.

Acute brain lesions on magnetic resonance imaging in relation to neurological outcome after cardiac arrest.

BACKGROUND: Magnetic resonance imaging (MRI) of the brain including diffusion-weighted imaging (DWI) is reported to have high prognostic accuracy in unconscious post-cardiac arrest (CA) patients. We documented acute MRI findings in the brain in both conscious and unconscious post-CA patients treated with target temperature management (TTM) at 32-34°C for 24 h as well as the relation to patients' neurological outcome after 6 months. METHODS: A prospective observational study with MRI was performed regardless of the level of consciousness in post-CA patients treated with TTM. Neurological outcome was assessed using the Cerebral Performance Categories scale and dichotomized into good and poor outcome. RESULTS: Forty-six patients underwent MRI at 3-5 days post-CA. Patients with good outcome had minor, mainly frontal and parietal, lesions. Acute hypoxic/ischemic lesions on MRI including DWI were more common in patients with poor outcome (P = 0.007). These lesions affected mostly gray matter (deep or cortical), with or without involvement of the underlying white matter. Lesions in the occipital and temporal lobes, deep gray matter and cerebellum showed strongest associations with poor outcome. Decreased apparent diffusion coefficient, was more common in patients with poor outcome. CONCLUSIONS: Extensive acute hypoxic/ischemic MRI lesions in the cortical regions, deep gray matter and cerebellum detected by visual analysis as well as low apparent diffusion coefficient values from quantitative measurements were associated with poor outcome. Patients with good outcome had minor hypoxic/ischemic changes, mainly in the frontal and parietal lobes.

Stereoisomeric analysis of 6,10,14-trimethylpentadecan-2-ol and the corresponding ketone in wing extracts from African Bicyclus butterfly species.

Gas chromatography (GC) and mass spectrometry (MS) were used to determine the stereoisomeric compositions of 6,10,14-trimethylpentadecan-2-ol and 6,10,14-trimethylpentadecan-2-one in wing extracts from 17 Bicyclus butterfly species from different regions of Africa. All samples were purified using solid phase extraction (SPE). Since some species contained both alcohol and ketone, these were separated and the ketone was reduced to the alcohol before analysis as either (R)-trans-chrysanthemoyl or (S)-2-acetoxypropionyl esters. A novel asymmetric synthesis was developed for a reference mixture of (2R/S,6S,10R)-6,10,14-trimethylpentadecan-2-ol with known composition of the eight stereoisomers. The mixture then was used as the (R)-trans-chrysanthemoyl esters to correlate each of the eight gas chromatographic peaks to a specific stereoisomer of the extracted wing compounds. Seven butterfly species showed (2R,6R,10R)-configuration of the alcohol, four species contained minute amounts of alcohol too small to determine the stereochemistry, nine species showed (6R,10R)-configuration of the ketone, and one species contained minute amounts of ketone too small to determine the stereochemistry. No other stereoisomers of alcohol or ketone could be detected in the extracts, and the quantities of the compounds in the wing extracts varied from 5 to 900 ng per sample for each species.

Trans-crustal structural control of CO2-rich extensional magmatic systems revealed at Mount Erebus Antarctica.

Erebus volcano, Antarctica, with its persistent phonolite lava lake, is a classic example of an evolved, CO2-rich rift volcano. Seismic studies provide limited images of the magmatic system. Here we show using magnetotelluric data that a steep, melt-related conduit of low electrical resistivity originating in the upper mantle undergoes pronounced lateral re-orientation in the deep crust before reaching shallower magmatic storage and the summit lava lake. The lateral turn represents a structural fault-valve controlling episodic flow of magma and CO2 vapour, which replenish and heat the high level phonolite differentiation zone. This magmatic valve lies within an inferred, east-west structural trend forming part of an accommodation zone across the southern termination of the Terror Rift, providing a dilatant magma pathway. Unlike H2O-rich subduction arc volcanoes, CO2-dominated Erebus geophysically shows continuous magmatic structure to shallow crustal depths of < 1 km, as the melt does not experience decompression-related volatile supersaturation and viscous stalling.

Fabry disease: results of the first UK hemodialysis screening study.

BACKGROUND: Fabry disease is an X-linked lysosomal storage disorder in which deficiency of α-Galactosidase A (α-Gal A), leads to accumulation of glycosphingolipids in the vascular endothelium, kidneys and heart. Males with classical disease present in childhood, however some individuals with low levels of α-Gal A activity present atypically with adult onset renal impairment. Screening studies in patients with established end-stage renal failure (ESRF) suggest that up to 1.5% of patients have sub-normal α-Gal A levels. We used the dried blood spot (DBS) enzyme activity test to screen for undiagnosed Fabry disease in patients with ESRF. METHODS: Male hemodialysis patients treated at a single UK center (n = 155) were screened using the DBS assay. In patients with low enzyme activity on DBS, α-Gal A activity was assessed in plasma and leucocytes. RESULTS: 8 of the 155 (5%) patients screened showed low enzyme activity on the DBS assay. Confirmatory testing of plasma and leucocyte α-Gal A activity showed normal activity in all cases tested, indicating a false positive DBS result. CONCLUSIONS: This study is the first screening program in UK hemodialysis patients using the DBS test and did not identify any new cases of Fabry disease. In this cohort, the DBS enzyme assay had a false positive rate of 2.6%, emphasizing the need for validation with alternative techniques.

A clinical trial of the Nomad portable X-ray unit.

OBJECTIVES: To compare image quality of intraoral radiographs made with the Nomad portable X-ray unit (Aribex, Inc.) and with a wall-mounted dental X-ray machine in a clinical setting. METHODS AND MATERIALS: Twelve patients requiring a full-mouth radiographic series for diagnostic purposes were recruited for the study, in which half of the radiographs (one side selected randomly) were made with the Nomad and half with a wall-mounted dental X-ray machine. Each individual image was evaluated independently by three reviewers for diagnostic utility and quality, using a three-point scale: 2 = perfect radiograph; 1 = acceptable for diagnostic purposes despite a small error; 0 = unacceptable. A total score was derived for each of the 220 images, each of the 12 patients, and the study population as a whole. RESULTS: The combined quality scores of the three reviewers for each set of radiographs ranged from 22-60 for the Nomad and 21-55 for the control units. Median scores were 33 for the Nomad and 33.5 for the control. The maximum possible score was nine films/half mouth x two points for perfect film x three reviewers = 54 (maximum 66 for 11 films). Three of the films, all on the same patient in a wheelchair, showed motion artifact (two with Nomad, one with control). DISCUSSION: Image quality for radiographs taken with the Nomad and a wall-mounted X-ray machine appears to be similar in a variety of clinical situations. Motion artifact is not a significant issue with the Nomad.

Employing machine learning for theory validation and identification of experimental conditions in laser-plasma physics.

The validation of a theory is commonly based on appealing to clearly distinguishable and describable features in properly reduced experimental data, while the use of ab-initio simulation for interpreting experimental data typically requires complete knowledge about initial conditions and parameters. We here apply the methodology of using machine learning for overcoming these natural limitations. We outline some basic universal ideas and show how we can use them to resolve long-standing theoretical and experimental difficulties in the problem of high-intensity laser-plasma interactions. In particular we show how an artificial neural network can "read" features imprinted in laser-plasma harmonic spectra that are currently analysed with spectral interferometry.

Factor structure and validity of the Depression, Anxiety and Stress Scale-21 in Swedish translation.

WHAT IS KNOWN ON THE SUBJECT?: The Depression, Anxiety and Stress Scale-21 (DASS-21) is a widely used measurement for psychological symptoms and distress. Some previous studies have shown that the DASS-21 can accurately measure symptoms of anxiety, depression and stress, while other studies have indicated that the DASS-21 mainly measures overall distress. The factor structure of the DASS-21 is important and debated since if affects interpretations of findings. WHAT DOES THIS PAPER ADD TO EXISTING KNOWLEDGE?: In this study, the DASS-21 was translated into Swedish and evaluated in three diverse samples. The DASS-21 subscales of Depression and Anxiety correlated significantly with corresponding criteria instruments. The DASS-21 Stress subscale showed more diverse associations with psychological distress. The analyses supported a bifactor model of the DASS-21 with three specific factors of depression, anxiety and stress as well as a general distress factor. WHAT ARE THE IMPLICATIONS FOR PRACTICE?: The results show that the DASS-21 may be used to measure unique symptoms of depression, anxiety and, with some caveat, stress as well as overall psychological distress. This study confirms that the DASS-21 is theoretically sound instrument that is feasible for both research and clinical practice. The DASS-21 can be an accessible tool for screening and evaluation in first-line mental health services. ABSTRACT: Introduction There is a constant need for theoretically sound and valid self-report instruments for measuring psychological distress. Previous studies have shown that the Depression, Anxiety and Stress Scale-21 (DASS-21) is theoretically sound, but there have been some inconsistent results regarding its factor structure. Aims The aim of the present study was to investigate and elucidate the factor structure and convergent validity of the DASS-21. Methods A total of 624 participants recruited from student, primary care and psychotherapy populations. The factor structure of the DASS-21 was assessed by confirmatory factor analyses and the convergent validity by investigating its unique correlations with other psychiatric instruments. Results A bifactor structure with depression, anxiety, stress and a general factor provided the best fit indices for the DASS-21. The convergent validity was adequate for the Depression and Anxiety subscales but more ambiguous for the Stress subscale. Discussion The present study overall supports the validity and factor structure of the DASS-21. Implications for practice The DASS-21 can be used to measure symptoms of depression and anxiety as well as overall distress. It can be useful for mental health nurses, and other first-line psychiatric professionals, in need of a short, feasible and valid instrument in everyday care.

Quality of patient care in the critical care unit in relation to nurse patient ratio: A descriptive study.

BACKGROUND: Intensive care is one of the most resource-intensive forms of medical care due to severely ill patients that are cared for in units with high staffing levels. Nursing's impact on the health of patients has shown that the number of nurses per patient and nurse education effects patient outcome. However, there are a lack of studies investigating highly specialised nurses in intensive care and their relation to patient outcome. METHOD: This is a retrospective study of critical care registry data (all patients >15 years) in general critical care units at seven university hospitals. RESULTS: Patient care and complications in relation to nurse/patient ratio showed that unplanned extubations occurred in 3-5.7% of cases. A difference between hospital patients' length of time on ventilation was found with the hospitals with the least amount of patients and with 0.5-0.6 specialist-nurse/patient a longer time on ventilation was noted. The length of ICU stay showed differences between the hospitals and nurse/patient ratios, with higher nurse/patient ratio with the longer length of ICU stay. CONCLUSION: Despite similarities between hospitals in relation to SAPS III on admission to critical care, there was a difference in nurse/patient ratios ranging from 1:1 to 0.5:1 and mean time on both invasive and noninvasive ventilation.

Extended particle-in-cell schemes for physics in ultrastrong laser fields: Review and developments.

We review common extensions of particle-in-cell (PIC) schemes which account for strong field phenomena in laser-plasma interactions. After describing the physical processes of interest and their numerical implementation, we provide solutions for several associated methodological and algorithmic problems. We propose a modified event generator that precisely models the entire spectrum of incoherent particle emission without any low-energy cutoff, and which imposes close to the weakest possible demands on the numerical time step. Based on this, we also develop an adaptive event generator that subdivides the time step for locally resolving QED events, allowing for efficient simulation of cascades. Further, we present a unified technical interface for including the processes of interest in different PIC implementations. Two PIC codes which support this interface, PICADOR and ELMIS, are also briefly reviewed.

Genome-wide analysis of integral membrane proteins from eubacterial, archaean, and eukaryotic organisms.

We have carried out detailed statistical analyses of integral membrane proteins of the helix-bundle class from eubacterial, archaean, and eukaryotic organisms for which genome-wide sequence data are available. Twenty to 30% of all ORFs are predicted to encode membrane proteins, with the larger genomes containing a higher fraction than the smaller ones. Although there is a general tendency that proteins with a smaller number of transmembrane segments are more prevalent than those with many, uni-cellular organisms appear to prefer proteins with 6 and 12 transmembrane segments, whereas Caenorhabditis elegans and Homo sapiens have a slight preference for proteins with seven transmembrane segments. In all organisms, there is a tendency that membrane proteins either have many transmembrane segments with short connecting loops or few transmembrane segments with large extra-membraneous domains. Membrane proteins from all organisms studied, except possibly the archaeon Methanococcus jannaschii, follow the so-called "positive-inside" rule; i.e., they tend to have a higher frequency of positively charged residues in cytoplasmic than in extra-cytoplasmic segments.

Architecture of helix bundle membrane proteins: an analysis of cytochrome c oxidase from bovine mitochondria.

We have analyzed the structure of mitochondrial cytochrome c oxidase in terms of general characteristics thought to be important for describing the architecture of helix bundle membrane proteins. Many aspects of the structure are similar to what has previously been found for the photosynthetic reaction center and bacteriorhodopsin. Our results lead to a considerably more precise general picture of membrane protein architecture than has hitherto been possible to obtain.

Architecture of beta-barrel membrane proteins: analysis of trimeric porins.

We have analyzed the known three-dimensional structures of trimeric porins from bacterial outer membranes. The distribution of surface-exposed residues in a direction perpendicular to the membrane is similar to that in helical membrane proteins, with aliphatic residues concentrated in the central 20 A of the bilayer. Outside these residues is a layer of aromatic residues, followed by polar and charged residues. Residues in the trimer interface are more conserved than residues not in the interface. By comparing the interface and noninterface residues, an interface preference scale has been derived that may be used as a basis for predicting interface surfaces in monomer models.

Mesotelencephalic dopamine system and reproductive behavior in the female rat: effects of ventral tegmental 6-hydroxydopamine lesions on maternal and sexual responsiveness.

The effects of lesions to the mesolimbic dopamine system on maternal and sexual behaviors in the female rat was assessed. Rat dams that were given ventral tegmental area microinfusions of 6-hydroxydopamine (6-OHDA) during lactation showed a persistent deficit in pup retrieval but were not impaired with respect to nursing, nest building, or maternal aggression. In addition, 6-OHDA-lesioned females failed to respond to amphetamine by showing locomotor hyperactivity. Administration of the dopamine blocker raclopride to neurologically intact dams also inhibited pup retrieval but had no effect on nursing. Females given 6-OHDA during pregnancy appeared completely unresponsive to pups, whereas no maternal deficits were seen in females that received 6-OHDA 8 weeks before parturition. Proceptive (hopping and darting) and receptive (lordosis) components of sexual behavior, assessed after ovariectomy and exogenous steroid hormone treatment, were not affected by mesolimbic 6-OHDA lesions.

Segmentation of human spindle and EMG responses to sudden muscle stretch.

Grouping of the EMG response produced by quick stretches of contracting muscles has been thought to reflect 'long loop reflexes' through cerebral cortex adding to the segmental stretch reflex. Our recordings from human muscle spindle afferents responding to such stretches show that these discharges also tend to be grouped. EMG grouping may therefore be a consequence of successive segmental reflexes rather than of additional delays in long loop reflex arcs.

The effects of 6-OHDA-induced dopamine depletions in the ventral or dorsal striatum on maternal and sexual behavior in the female rat.

The effects of dopamine-depleting 6-OHDA infusions in the ventral or dorsal striatum on maternal and sexual behaviors were examined in female rats. Like sham-operated controls, lactating rats receiving 6-OHDA in the ventral striatum built good nests, nursed the infants and showed maternal aggression toward strange intruders. By contrast, the lesioned females performed poorly in tests for pup retrieval, as reflected in greatly protracted retrieval latencies. There was no effect of ventral striatal DA depletions on proceptive and receptive elements of female sexual behavior, which was studied after lactation following ovariectomy and exogenous administration of ovarian hormones, but these animals did show an attenuated hyperactivity response to a low dose of amphetamine. Females with dopamine lesions in the dorsal striatum did not differ from controls with respect to maternal and sexual behavior, but they did show an enhanced hyperactivity response to amphetamine treatment.

An anthropometric study as the basis for sizing anatomically designed mittens.

This study describes a method for sizing mittens based upon an analysis of the user populations and the hand measurements of these users. New anatomically designed military mittens were developed according to the users' requirements and ergonomic and physiological requirements of dexterity and heat balance. A statistical study of anthropometrical hand measures of the intended users lead to the choice of hand length and hand circumference as the basis for a new sizing system. The mittens were tested in two sizes in large wear trials. These two sizes fitted well to the test group - i e, young conscripts. If the whole adult population is considered, probably two more sizes would be needed.

User-oriented product development applied to functional clothing design.

A method for user-oriented product development is presented. After a theoretical introduction the method is applied to the development of functional clothing. The characteristic of the method is its starting-point with the user in the use-situation. Important product demands are derived from use-analyses. Three case-studies are described where this method has been applied. They concern working clothes, clothes for the elderly and military clothing. The quality of this methods as an instrument for product development in the clothing area is evaluated by comparing, on the one hand, this method with those usually used in the clothing industry, and on the other hand the new products with those formerly used. The method for user-oriented product development has proved to be complementary to conventional methods. It should be applied to products whose functional properties are of great importance. The method can be generalised to all users and to products with close connection to human beings.