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Biomedical subjects

J E Fischer

Publications and source records attributed to J E Fischer.

At least 19 recordsLinked to original sources

Responsiveness and habituation of soluble ICAM-1 to acute psychosocial stress in men: determinants and effect of stress-hemoconcentration.

We studied the psychophysiology of soluble intercellular adhesion molecule-1 (sICAM-1) in 25 apparently healthy middle-aged men who underwent an acute psychosocial stressor three times with one week apart. Measures of the biological stress response were obtained at week one and three. The magnitude of the sICAM-1 stress response showed no habituation between individual visits. At week one, cognitive stress appraisal independently predicted integrated sICAM-1 area under the curve (AUC) between rest, immediately post-stress, and 45 min and 105 min post-stress (beta=0.67, p=0.012, deltaR(2)=0.41). Diastolic blood pressure AUC (beta=-0.45, p=0.048, deltaR(2)=0.21) and heart rate AUC (beta=0.44, p=0.055, deltaR(2)=0.21) were independent predictors of sICAM-1 AUC at week three. Adjustment for hemoconcentration yielded a decrease in sICAM-1 levels from rest to post-stress (p<0.001). Stress responsiveness of plasma sICAM-1 was predicted by stress perception and hemodynamic reactivity and affected by stress-hemoconcentration but unrelated to cortisol reactivity and not readily adapting to repeated stress.

Acute Disease↗

[Treatment of enteric fistula in open abdomen].

Formation of enteric fistulas frequently complicates the open abdomen in patients who have sustained traumatic injury. The post-traumatic subset of patients with enterocutaneous fistula enjoy better than average recovery. To optimize this recovery, a systematic management approach is required. Patients must first be stabilized with nutritional support, control of sepsis, and special wound management systems to prevent further deterioration of the abdominal wall. Investigation of the origin, course, and characteristics of the fistula provides information about its likelihood to close without operation. Definitive operative therapy may be necessary to resolve the fistula and close the abdominal wall. Finally, healing support includes nutritional support and physical and occupational therapies to restore patients to pre-injury states.

Abdominal Injuries↗

Disorder effects in focused-ion-beam-deposited Pt contacts on GaN nanowires.

The current-bias (I-V) characteristics at various temperatures, T, of focused-ion-beam (FIB)-deposited Pt contacts on GaN nanowires evolves from low-resistance ohmic (linear I-V) to rectifying as the diameter increases, and both exhibit strongly nonmetallic T-dependence. The small-diameter (66 nm) T-dependent resistance is explained by two-dimensional variable range hopping with a small characteristic energy, ensuring low resistance at 300 K. For large diameters (184 nm), back-to-back Schottky barriers explain the nonlinear I-V at all T values and permit an estimate of doping concentration from the bias-dependent barrier height. Both behaviors can be understood by accounting for the role of FIB-induced amorphization of GaN underneath the contact, as confirmed by cross-sectional transmission electron microscopy.

Journal Article↗

The effect of a training course in aggression management on mental health nurses' perceptions of aggression: a cluster randomised controlled trial.

Nurses' attitudes towards patient aggression may influence their behaviour towards patients. Thus, their enhanced capacity to cope with aggressive patients may nurture more positive attitudes and alleviate adverse feelings emanating from patient aggression. This cluster randomised controlled trial conducted on six psychiatric wards tested the hypotheses that a 5 day training course in aggression management would positively influence the following outcome measures: Nurses' perception and tolerance towards patient aggression and resultant adverse feelings. A repeated measures design was employed to monitor change. No effect was found. The short time frame between the training course and the follow up measurement or non-responsiveness of the measurement instruments may explain this finding.

Adaptation, Psychological↗

The perception of aggression by nurses: psychometric scale testing and derivation of a short instrument.

Patient aggression is a serious problem in psychiatric nursing. Nurses' attitudes towards aggression have been identified as mediating the choice of nursing interventions. To date, investigations are lacking which elucidate the stability of one of the few scales for measuring the attitude of aggression. This study aimed to investigate the test-retest stability of the Perception of Aggression Scale and to derive a shortened version. In order to test the reliability of the Perception of Aggression Scale items, three groups of psychiatric nurses were requested to fill in the Perception of Aggression Scale twice (30 student nurses after 4 days, 32 qualified nurses after 14 days and 36 qualified nurses after 70 days). We derived the shortened version from an independent data set obtained from 729 psychiatry nurses using principal component analysis, aiming to maximize parsimony and Cronbach's alpha. Amongst competing short versions, we selected those with the highest reliability at 70 or 14 day retest. A scale using 12 of the original 32 items was derived yielding alphas of r = 0.69 and r = 0.67 for the two POAS factors with retest reliabilities of r = 0.76 and r = 0.77. The shortened scale offers a practical and viable alternative to the longer version.

Adult↗

Predicting inpatient violence in acute psychiatric wards using the Brøset-Violence-Checklist: a multicentre prospective cohort study.

The Norwegian Brøset-Violence-Checklist (BVC) is one of the few instruments that is suitable for short-term prediction of violence of psychiatric inpatients by nursing staff in routine care. The instrument assesses the presence or absence of six behaviours or states frequently observed before a violent incident. We conducted a study to elucidate whether the predictive properties of the BVC are retained in other psychiatric settings than the original north-Norwegian validation dataset. During their admission period, 219 consecutive patients admitted to six acute psychiatric wards were assessed as to the risk for attack using a German version of the BVC (BVC-G). Data on preventive measures were concurrently collected. Aggressive incidents were registered using an instrument equivalent to the Staff Observation of Aggression Scale (SOAS-R). Fourteen attacks towards staff were observed with incident severity ranging from 5 to 18 of a possible 22 points. BVC-G sensitivity was 64.3%, the specificity 93.9%, the positive predictive value 11.1%, and the area under the receiver operating characteristic curve 0.88. In some false positive cases intense preventive measures had been implemented. The predictive accuracy of the BVC-G proved consistent with the Norwegian original.

Cohort Studies↗

The effectiveness of two interventions in the management of patient violence in acute mental inpatient settings: report on a pilot study.

Systematic risk assessment and training courses have been suggested as interventions to deal with patient violence in psychiatric institutions. A dual centre prospective feasibility study was conducted on two Swiss psychiatric admission wards to test the hypothesis that such interventions will reduce the frequency and severity of violent events and coercion. A systematic aggression risk assessment, in combination with a standardized training course in aggression management was administered and the frequency and severity of aggressive incidents and the frequency of coercive measures were registered. The incidence rates of aggressive incidents and attacks showed no significant reduction from the baseline through risk prediction and staff training, but the drop in coercive measures was highly significant. A 'ward effect' was detected with one ward showing a decline in attacks with unchanged incidence rates of coercion and the other ward showing the opposite. The severity of the incidents remained unchanged whilst the subjective severity declined after the training course. We conclude that a systematic risk assessment and a training course may assist in reducing the incidence rate of coercive measures on psychiatric acute admission wards. Further testing of the interventions is necessary to measure the effect of the training alone and to counteract 'ward effects'.

Acute Disease↗

Monocyte proinflammatory cytokine release is higher and glucocorticoid sensitivity is lower in middle aged men than in women independent of cardiovascular risk factors.

OBJECTIVE: To investigate whether stimulated monocyte cytokine release and its inhibition by glucocorticoids differs between men and women. DESIGN: In vitro monocyte interleukin 6 (IL-6) and tumour necrosis factor alpha (TNFalpha) release after lipopolysaccharide stimulation were assessed with and without co-incubation with increasing doses of dexamethasone and hydrocortisone separately. Glucocorticoid sensitivity was defined as the amount of a particular glucocorticoid required to inhibit lipopolysaccharide stimulated monocyte cytokine release by 50%. The established cardiovascular risk factors of age, body mass index, number of cigarettes smoked daily, low density cholesterol to high density cholesterol ratio, systolic and diastolic blood pressure, and haemoglobin A1c were used as covariates. SETTING: Aircraft manufacturing plant in southern Germany. PATIENTS: 269 middle aged male and 36 middle aged female employees. RESULTS: Release of monocyte IL-6 and TNFalpha (each p = 0.001) was higher in samples from men than in those from women. Inhibition of lipopolysaccharide stimulated IL-6 and TNFalpha release by either glucocorticoid was less pronounced in samples from men than in those from women (IL-6: dexamethasone p = 0.033, hydrocortisone p = 0.029; TNFalpha: dexamethasone p < 0.001, hydrocortisone p = 0.089). CONCLUSIONS: The finding suggests that proinflammatory activity of circulating monocytes is higher in men than in women independent of cardiovascular risk factors, thereby providing one explanation for the relatively greater coronary risk in men.

Adult↗

Neuromotor development from kindergarten age to adolescence: developmental course and variability.

The normal course of neuromotor development is described from 5 to 18 years of age. The data have been collected by use of the Zurich Neuromotor Assessment, a standardized testing procedure in which distinct motor tasks are judged with regard to timed performance and movement quality (associated movements of the contralateral and ipsilateral extremity, face, head and body). In the Zurich Growth and Development Studies, norms for these motor tasks have been established in 662 children and adolescents from middle class families. Neuromotor development is not a phenotypic entity, but evolves from motor functions of different complexity. With regard to timed performance and movement quality developmental course, gender differences and laterality vary considerably over age and among motor tasks. Thus, for a reliable assessment of the neuronotor developmental status in children, a standardized test instrument, well-trained examiners and normative data are required.

Adolescent↗

Thermoelectric power of p-doped single-wall carbon nanotubes and the role of phonon drag.

We measured thermoelectric power S of bulk single-wall carbon nanotube materials p doped with acids. In contrast to oxygen-exposed or degassed samples, S is very small at the lowest temperatures, increases superlinearly above a characteristic and sample-dependent T, and then levels off. We attribute this unusual behavior to 1D phonon drag, in which the depression of the Fermi energy cuts off electron-phonon scattering at temperatures below a characteristic T0. This idea is supported by a model calculation in which the low temperature behavior of phonon drag is specifically related to the one-dimensional character of the electronic spectrum.

Journal Article↗

[Work, stress and cardiovascular diseases].

Classical risk factors such as smoking, hypertension or elevated plasma levels of cholesterol account only for part of the variance in the probability of cardiovascular disease. Work related psychosocial factors such as high job demands, low decision latitude or lack of social support often pertain during extended periods. Such work related stressors may modulate biological risk factors (e.g. by increasing the risk of hypertension) or may elicit adverse health behaviour (increased tobacco consumption). Several longitudinal cohort studies indeed support the notion of an association between work related stressors and the risk of cardiovascular disease. However, the exact biological mechanisms conferring this risk remain in part elusive. The general stress model of allostasis and allostatic load may allow studying possible pathways in more detail and within a common conceptual framework. Allostasis refers to the often useful acute stress reaction that prepares the organism for flight or fight threatening situations. Allostatic load summarizes the wear and tear inflicted upon the organism after repeated or dysregulated allostatic efforts. The framework of allostasis and allostatic load permits to investigate the direct effect of work related stressors on the primary stress reaction (reduced vagal tone, increased sympathetic tone and increased activity of the hypothalamic-pituitary-adrenal axis) as well as the effect on biological process, which are regulated by the acute stress reaction. Longitudinal studies have shown an inverse association between a score operationalizing allostatic load by means of 10 biological measures and functional status/mortality. These studies in elderly individuals remain to be replicated using the same framework for working age populations.

Adaptation, Psychological↗

Raman spectroscopy and structure of crystalline gallium phosphide nanowires.

Gallium phosphide nanowires with a most probable diameter of approximately 20.0 nm and more than 10 microns in length have been synthesized by pulsed laser vaporization of a heated GaP/5% Au target. The morphology and microstructure of GaP nanowires have been investigated by scanning electron microscopy and transmission electron microscopy. Twins have been observed along the crystalline nanowires, which have a growth direction of [111]. Raman scattering shows a 4 cm-1 downshift of the longitudinal optical phonon peak in the nanowire with respect to the bulk; the transverse optical phonon frequency and line width are, however, the same as in the bulk. The quantum confinement model first proposed by Richter et al. cannot explain the observed behavior of the Raman modes.

Crystallography↗

Coercive procedures and facilities in Swiss psychiatry.

BACKGROUND: Coercive measures in psychiatry,although in many cases effective in violence management and injury reduction, have been criticised from a consumerist point of view. METHOD: A questionnaire regarding coercive facilities and procedures was dispatched to the charge nurses of 86 acute psychiatric admission wards in German speaking Switzerland covering a catchment area of 75% of the Swiss population. RESULTS: 95% of all wards responded rendering the survey representative. The majority of wards have seclusion rooms and 55% of charge nurses perceive seclusion facilities as adequate. Two to twenty staff members are involved in overwhelming dangerous patients and some discontent is expressed at the haphazard fashion in which such events occur. Almost 70% of the wards use a form for reporting, 42 % of wards keep statistics on violent incidents and 17% of wards have access to these data. Of all wards 84% register injections against patients' will, 83% seclusion, and 78% mechanical restraint and a minority of wards register the coercive administration of oral medication, forced nutrition, threats of coercive measures in case of pharmacological non-compliance. DISCUSSION: Isolation, the coercive administration of medicine and restraint techniques are sensitive forms of treatment. Deficits reported by the charge nurses point to the need for enhanced facilities and improved forms of coercion management such as training in the use of mechanical restraints and the overwhelming of dangerous patients. CONCLUSION: The data show considerable differences in the facilities, the use, and the recording of coercive measures in the area under scrutiny.

Adult↗

Use of the Internet by medical doctors in Switzerland.

QUESTIONS UNDER STUDY: To investigate the utilisation of the Internet by primary care physicians for medical purposes during their daily practice, and to clarify the reasons for use or non-use of this technology. METHODS: Cross-sectional postal survey in German-speaking Switzerland employing a purpose-designed pre-validated 69-item questionnaire. A random sample of 2009 primary care physicians participated in the investigation. MAIN OUTCOME MEASURES: Number of primary care physicians with access to the Internet; reasons for using the Internet during consultations; sources of information in solving medical problems arising from concurrent patient care. RESULTS: 55% of the physicians returned the completed questionnaire. 75% of respondents reported access to the Internet. Only 7% use the Internet during patient consultations. The main reasons for not using the Internet were time pressure and concerns about potential negative interaction with physician-patient communication. To solve patient-specific problems arising during daily practice, 59% of the practitioners consult text-books or colleagues. Only 14% of respondents report regularly finding useful information on the Internet. Internet users assess information quality by checking on authorship, institution, publishing company, or whether the information is sponsored by a third party with a potential conflict of interest. CONCLUSIONS: Access to the Internet is widespread amongst German-speaking Swiss primary care physicians. Only a small minority use the Internet for information retrieval during consultation hours. Electronic information systems need to be tailored to the needs of primary care physicians.

Communication↗

[Tests and criteria in diagnosis of chronic hypotension--a systematic review].

The diagnosis of hypotensive circulatory disorders is based on a variety of criteria and classifications. This paper aims to provide a systematic review of published definitions and diagnostic criteria for hypotensive disorders. Searches for relevant papers were undertaken in Medline, Winspirs version (January 1966 to December 1999) and in textbooks of internal medicine. References of all identified articles were also searched. Publications in English, French, German and Italian were included. In 47 articles, 56 different reference were made to definitions and diagnostic criteria for hypotension. At present there is no uniform definition of hypotension and there are no clear, standardized criteria on which to base a diagnosis. Basically, one distinguishes between two schools of thought. The Anglo-American literature describes hypotensive disorders in terms of orthostatic dysregulation in the presence of an underlying primary condition, whereas the German-speaking countries use mixed approaches. On the one hand, the questionable pathological value of essential/primary hypotension is discussed; on the other hand, tests for orthostatic circulatory function, like the Schellong test, appear to have become established. Neither resting blood pressure limits nor a drop in blood pressure during orthostatic challenge can be used to diagnose hypotension. The orthostatic test is a better diagnostic tool than resting blood pressure. Hypotension is probably difficult to classify in simple terms because it is usually a symptom of numerous disorders hallmarked by a variety of pathophysiological mechanisms. Hypotension should indeed be understood as a secondary symptom of a primary disease. Accordingly, the primary aim of diagnostic efforts should be to uncover the underlying condition. The studies included were of insufficient methodological quality. Moreover, the heterogeneity among the individual studies made pooled analysis impossible. This systematic review revealed a marked lack of studies with valid results.

Blood Pressure↗

The transcription factors NF-kappab and AP-1 are differentially regulated in skeletal muscle during sepsis.

Sepsis is associated with increased muscle proteolysis and upregulated transcription of several genes in the ubiquitin-proteasome proteolytic pathway. Glucocorticoids are the most important mediator of sepsis-induced muscle cachexia. Here, we examined the influence of sepsis in rats on the transcription factors NF-kappaB and AP-1 in skeletal muscle and the potential role of glucocorticoids in the regulation of these transcription factors. Sepsis was induced by cecal ligation and puncture (CLP). Control rats were sham-operated. NF-kappaB and AP-1 DNA binding activity was determined by electrophoretic mobility shift assay (EMSA) in extensor digitorum longus muscles at different time points up to 16 h after sham-operation or CLP. Sepsis resulted in an early (4 h) upregulation of NF-kappaB activity followed by inhibited NF-kappaB activity at 16 h. AP-1 binding activity was increased at all time points studied during the septic course. When rats were treated with the glucocorticoid receptor antagonist RU38486, NF-kappaB activity increased, whereas AP-1 activity was not influenced by RU38486. The results suggest that NF-kappaB and AP-1 are differentially regulated in skeletal muscle during sepsis and that glucocorticoids may regulate some but not all transcription factors in septic muscle.

Animals↗

Adrenergic blockade reduces skeletal muscle glycolysis and Na(+), K(+)-ATPase activity during hemorrhage.

BACKGROUND: Recent evidence suggests that hyperlactatemia in shock may reflect accelerated aerobic glycolysis linked to activity of the Na(+), K(+)-ATPase rather than hypoxia. Epinephrine stimulates glycolysis in resting muscle largely by stimulating Na(+), K(+)-ATPase activity. This study evaluates the effects of hemorrhagic shock, with and without combined alpha- and beta-adrenergic receptor blockade, on lactate production, glycogenolysis, Na(+)-K(+) pump activity, and high-energy phosphates in rat skeletal muscle. METHODS: Male Sprague-Dawley rats in four treatment groups were studied: unhemorrhaged control not receiving blockers (CN), controls receiving blockers (CB), shocked animals not receiving blockers (SN), and shocked rats receiving blockers (SB). Shocked rats (SN and SB) were bled to a MAP of 40 mm Hg, maintained for 60 min. Blocker groups (CB and SB) received propranolol and phenoxybenzamine. Arterial blood was drawn for plasma lactate, epinephrine, norepinephrine, and gas analysis. Lactate, glycogen, glucose 6-phosphate, ATP, phosphocreatine, and intracellular Na(+) and K(+) were determined in extensor digitorum longus and soleus muscles. For comparison, muscles were exposed to epinephrine and/or ouabain in vitro. RESULTS: With the exception of P(a)CO(2), HCO(3), and base excess in the SN group, no significant differences in arterial blood gas parameters were noted. Adrenergic blockade significantly reduced plasma lactate concentration. In shocked rats, adrenergic blockade significantly reduced muscle lactate and glucose 6-phosphate accumulation. Intracellular Na(+):K(+) ratio was decreased in SN rats, implying increased Na(+)-K(+) pump activity. Adrenergic blockade raised the intracellular Na(+):K(+) ratio in shocked animals, implying decreased pump activity. Epinephrine exposure in vitro stimulated muscle lactate production, raised glucose 6-phosphate content, and significantly reduced soleus phosphocreatine stores. CONCLUSIONS: Neither hypoxia nor defective oxidative metabolism appeared responsible for increased glycolysis during hemorrhagic shock. Adrenergic blockade concurrently reduced plasma lactate, muscle levels of lactate and glucose 6-phosphate, and muscle Na(+)-K(+) pump activity during shock. Rapid skeletal muscle aerobic glycolysis in response to increased plasma epinephrine levels may be an important contributor to increased glycolysis in muscle and increased plasma lactate during hemorrhagic shock.

Adenosine Triphosphate↗