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Biomedical subjects

J Jensen

Publications and source records attributed to J Jensen.

At least 199 records · Page 11Linked to original sources
PubMed1996

Pectoral fin locomotion in the striped surfperch. II. Scaling swimming kinematics and performance at a gait transition

In this study, we report the first allometric equations relating gait parameters and swimming speed to body size for fish employing pectoral fin locomotion. Comparisons of locomotor kinematics and performance among striped surfperch (Teleostei: Embiotocidae) are made at the pectoral­caudal gait transition speed (Up-c). Up-c is considered to elicit physiologically equivalent levels of exercise in animals varying over 100-fold in body mass (Mb) by virtue of dynamically similar pectoral fin movements (constant duty factor, length-specific stride length and fin-beat amplitude) and size-independent propulsive efficiency. At Up-c, pectoral fin-beat frequency scales in proportion to Mb-0.12±0.03, a size-dependence consistent with that observed for stride frequency in fishes swimming by axial undulatory propulsion and in many running tetrapods. It is proposed that the similarity in the scaling of frequency in these vertebrate groups reflects an underlying similarity in the allometry of the maximal velocity of muscle shortening. Absolute Up-c (m s-1) generally increases with body size, but the fastest speeds are not exhibited by the largest animals. A pattern of declining performance in fish 23 cm in standard length and longer may be related to their disproportionately small fin areas and aspect ratios. The pronounced negative allometry of Up-c expressed as standard body lengths per second indicates that a given length-specific speed does not induce comparable levels of activity in large and small fish. Thus, normalization of swimming speed to body length may not be a sufficient correction for kinematic comparisons across size.

Journal Article↗
PubMed1996

Redesigning the RN and NA roles.

To ensure optimal utilization of RNs, the nursing care delivery system in a surgical nursing division assessed the tasks that could be delegated to ancillary personnel. Nursing assistants completed competency-based training and after six months, several positive outcomes were evident: dramatic decreases in overtime, improved patient care and increased patient and staff satisfaction.

Humans↗
PubMed1995

[Waiting lists--how valid are the official numbers? Evaluation of a waiting list at a department of orthopedic surgery].

With increasing waiting lists for admission to hospital, the aim of this study was to investigate the reliability of an orthopaedic waiting list. Questionnaires were sent to every patient listed as waiting for more than three months. The questionnaire addressed the current symptoms and the current need for surgical treatment. In case of no reply, a further evaluation was done before eventual removal from the waiting list. Of 809 questionnaires mailed, replies were received from 409. A total of 376 were removed from the list, including 111 due to registration errors in the central data base. This study has shown how the indication for operation changes during the waiting period but also that information from data bases can be most unreliable. We find the reasons so general, that we recommend a corresponding evaluation of other waiting lists. Altogether, today's waiting list is faulty and thus provides a wrong basis for management.

Denmark↗
PubMed1995

Effects of treatment on cardiovascular risk among smokeless tobacco users.

BACKGROUND: Studies show sustained levels of nicotine among young males using smokeless tobacco, causing concern for subsequent cardiovascular risk. Also, there is little information on effects of nicotine replacement on cardiovascular risk in cessation programs. This study investigates the effects of nicotine gum replacement in smokeless tobacco cessation on cardiovascular risk factors. METHODS: Smokeless tobacco users, ages 18-65, were randomly assigned in a double-blind fashion to 2-mg nicotine or placebo gum. At baseline, Week 4, and Week 8, dependent measurements, heart rate, blood pressure, and weight were recorded, and fasting lipoprotein profiles were drawn. RESULTS: This paper focuses on the smokeless tobacco users who refrained from use during the study period (N = 56). The nicotine gum group weighed less (P = 0.033) than the placebo group throughout the study and weight increased at a significant rate between Weeks 4 and 8 for both groups as gum decreased. Triglycerides were higher for the nicotine gum group than the placebo group (P = 0.031), with triglycerides decreasing between Weeks 4 and 8, with a similar effect seen among nonabstinent smokeless tobacco users. There was no dose, time, or dose by time effect for the other dependent measures. CONCLUSIONS: Among smokeless tobacco users who were abstinent, weight increased, with subjects on nicotine gum weighing less throughout the study. The lipoprotein profile, heart rate, and blood pressure did not improve over time, contrary to smokers in whom HDL increases and heart rate decreases with cessation. This could relate to different routes of administration, pharmacokinetics, or by-products of tobacco smoking being absent in smokeless tobacco. In addition, nicotine gum appeared to have neither an adverse nor a positive effect on heart rate, blood pressure, LDL, HDL, or total cholesterol.

Adult↗
PubMed1995

Protein quality and digestibility of new high-lysine barley varieties in growing rats.

Four new high-lysine barley mutants, the variety 'Lysimax', with the high-lysine gene lys3a and the mutants mother variety 'Sultan' were grown in a field trial in 1993 at Risø, Denmark. Mutants 609, 1242, 1385 and 1405 yielded in the range of 89 to 98 percent and cv 'Lysimax' yielded 102 percent of cv 'Sultan' (100 percent). One-thousand kernel weights for the mutants were in the range of 87 to 97 percent and cv 'Lysimax' 83 percent of cv 'Sultan' (100 percent). Protein contents of the mutants were slightly higher, in the range of 13.2 to 13.6 percent, than of cv 'Sultan' (13.1 percent) and 'Lysimax' which had a protein content of 12.6 percent. Fat content was higher in 'Lysimax' and in the mutants except for mutant 1385 than in cv 'Sultan' while dietary fibre contents of the barleys were similar. The levels of beta-glucans and starch were usually lower in 'Lysimax' and in the mutants. The highest lysine levels: 4.6, 4.0 and 3.7 g/16 g N occurred in cv 'Lysimax' and mutants 609 and 1405 compared to 3.3, 3.3 and 3.2 for cv 'Sultan' and mutants 1242 and 1385, respectively. Mutants 609 and 1405 and cv 'Lysimax' also had higher levels of threonine, histidine and valine. The increased lysine contents resulted in large, at most 20 percent, increases in biological value; 88.8, 81.7 and 78.3 percent for cv 'Lysimax' and mutants 609 and 1405 compared to 74.2 percent for cv 'Sultan'. True protein digestibilities and energy digestibilities were slightly lower in 'Lysimax' than in 'Sultan', 5.3 and 4.3 percentage units, respectively. It is concluded that the development of high-lysine barley varieties is very beneficial for meeting the requirements of indispensable amino acids for humans and monogastric animals. In addition, nitrogen excretion into the environment is drastically reduced due to the higher biological values of the mutants.

Animals↗
PubMed1995

Developmental and symptom specificity of hopelessness, cognitive errors, and attributional bias among clinic-referred youth.

The present study examined the unique and interactive relationships between age and indices of psychopathology (i.e., anxiety, aggression, and depression), with three types of maladaptive cognitions: hopelessness, negative cognitive errors, and attributional bias. Some negative cognitions were not unique to depression and were associated with broader psychopathology. Developmental considerations also influenced some negative cognitions or qualified the association between negative cognitions and depression.

Adolescent↗
PubMed1995

Binding of ADP to sarcoplasmic reticulum Ca(2+)-ATPase in the absence of Mg2+ is specifically inhibited by thapsigargin: observations on the ligand stoichiometry.

The conditions of nucleotide binding to native, though partly purified, Ca(2+)-ATPase from SR as well as the stoichiometry of nucleotide and strontium binding and the phosphorylation capacity was reevaluated. Binding of MgADP appeared to be aberrant whereas even high-affinity binding of [14C]-ADP took place in the absence of Mg2+. Also low-affinity ATP binding was possible in the absence of divalent cations. A heterogeneity in ADP binding compatible with a two-component model in the absence of thapsigargin was changed to an apparent homogeneity of low-affinity receptors following a mole:mole interaction of enzyme and thapsigargin. Since the affinity of both components was reduced by thapsigargin, high- as well as low-affinity ADP binding seem to be specific and probably to the substrate receptor proper. Analysis of ADP binding isotherms in the absence of Mg2+ according to a model of two independent populations of sites was compatible with a binding capacity of 8.49 +/- 0.43 nmoles/mg protein corresponding to a molecular mass of 118 +/- 6 kD per ADP site. The same total binding capacity was found for ATP. The phosphorylation capacity corresponded to more than one and less than two approximately P per two 110-kD peptides (formally one approximately P per 154 kD protein). Specific binding of Ca2+ and the congener Sr2+ to SR Ca(2+)-ATPase was compatible with their interaction with a single population of sites. The binding capacity was equal to one divalent cation per nucleotide binding peptide. The binding of one nucleotide and one divalent cation per approximately 110 kD peptide and the absence of cooperativity in divalent cation binding might imply that Ca(2+)-ATPase works as a monomer.

Adenosine Diphosphate↗
PubMed1995

Ischemia monitoring with on-line vectorcardiography compared with results from a predischarge exercise test in patients with acute ischemic heart disease.

Information from 24-hour monitoring with on-line vectorcardiography, starting immediately after admission, was compared with results from a predischarge exercise test 3-13 days after admission. A total of 169 patients with acute myocardial infarction and 73 patients with unstable angina pectoris were investigated. Patients were followed for 487 +/- 135 days. During the follow-up period, 19 patients (8%) died from cardiac causes and 34 (14%) were hospitalized for a myocardial infarction. The QRS vector difference (QRS-VD), ST change vector magnitude (STC-VM), ST vector magnitude (ST-VM), and ST vector leads X, Y, Z were monitored. Patients with ST depression on the exercise test showed higher occurrence of transient, supposedly ischemic, episodes of QRS-VD, STC-VM, and ST-VM than patients without ST depression. The sensitivity and specificity of identifying patients with ST depression at the exercise test were respectively, 71 and 47% for QRS-VD episodes, 58 and 56% for ST-VM episodes, and 55 and 65% for STC-VM episodes. The maximum ST depression at the exercise test was related to the maximum ST depression in vector lead X (r = .44, P < .001) and the number of STC-VM (r = .40, P < .001), ST-VM (r = .37, P < .001), and QRS-VD (r = .33, P < .001) episodes on the VCG. In multivariate analysis, maximum ST depression in vector lead X and STC-VM episodes were the best determinants for ST depression at the exercise test. In a Cox regression model, the optimal combination of exercise test data in patients who died from cardiac causes exhibited a global chi-square value of 20.0. The combination of these data and the number of STC-VM episodes increased the global chi-square value to 30.6. This study indicates that in patients with acute ischemic heart disease, early continuous vectorcardiographic monitoring may predict the results from a predischarge exercise test and also contributes independent prognostic information beyond that of exercise test data.

Angina, Unstable↗
PubMed1995

Psychiatric morbidity in primary public health care: a Nordic multicentre investigation. Part I: method and prevalence of psychiatric morbidity.

The prevalence of mental illness in five different Scandinavian primary care populations was investigated in this study. Patients consecutively consulting their general practitioner a particular week-day were included in the study. Initially the SCL-25 was applied and next the high scores and a sample of the low scores were interviewed by the PSE. In the analysis the screening procedure was first validated. The internal validity of the SCL was tested by means of Rasch latent structure analysis and the external validity tested by ROC/QROC analysis. Based on this, a short 8-item version of the SCL was developed. The prevalence of mental illness in all centres was 0.26 with a minimum of 0.14 in Nacka and a maximum of 0.34 in Turku.

Adolescent↗
PubMed1995

Different beta-adrenergic receptor density in different rat skeletal muscle fibre types.

The effects of adrenaline on skeletal muscle differ between fibre types. The aim of the present study was to investigate the beta-adrenoceptor density, affinity and subtype in rat skeletal muscles with different fibre type composition. beta-Adrenoceptors were determined in cryostat sections to avoid methodological problems with variable recovery, using the non-selective beta-adrenoceptor ligand [3H]CGP-12177 and beta 1- and beta 2-selective cold ligands CGP 20712A and ICI 118,551. In the presence of protease inhibitors [3H]CGP-12177 binding was stable, saturable, reversible, and displaceable. Scatchard analysis of binding saturation data was compatible with a single class of specific binding sites. Binding site density (Bmax) was higher (P < 0.02) in adult soleus (9.38 +/- 1.13 fmol x mg protein-1) than in adult extensor digitorum longus (4.74 +/- 0.39 fmol x mg protein-1), whereas the dissociation constants (Kd), 0.37 +/- 0.05 and 0.31 +/- 0.04 nM for soleus and extensor digitorum longus, respectively, were not significantly different. For young rats (5-6 weeks), Bmax was 11.21 +/- 0.33 and 5.45 +/- 0.11 fmol x mg protein-1 (P < 0.05), and Kd was 0.27 +/- 0.02 and 0.24 +/- 0.04 nM for soleus and epitrochlearis, respectively. These results correspond to a receptor density of 2 and 1 pmol x g w.wt.-1 in muscles containing.mainly type I and type II fibres, respectively. Displacement studies with CGP 20712A and ICI 118,551 were compatible with mainly beta 2-adrenoceptors, but 7-10% beta 1-adrenoceptors were present in both types of muscle.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenergic beta-Antagonists↗