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Biomedical subjects

S Holm

Publications and source records attributed to S Holm.

At least 127 records · Page 7Linked to original sources
PubMed1995

The medical hierarchy and perceived influence on technical and ethical decisions.

OBJECTIVE: To investigate the influence of hierarchial position and perceived influence on ethical and technical decisions. DESIGN: The study was conducted as a postal questionnaire survey. SUBJECTS: A random sample of 329 Danish physicians working at departments of internal medicine and related subspecialties. Of these, 270 (82%) returned a completed questionnaire. MAIN OUTCOME MEASURE: Self-reported perceived influence in discussions about technical and ethical issues in connection with decisions to terminate treatment for patients with terminal malignant illness. RESULTS: The odds ratio for perceived influence between consultants and house officers is 14.9 for ethical issues, 44.9 for technical issues, and 652.3 for questions concerning departmental policy. Gender plays no role, when one controls for hierarchial position. CONCLUSIONS: Hierarchial position is the major determinant of perceived influence on technical and ethical decisions. Position seem to play a larger role in technical than in ethical decisions.

Decision Making↗
PubMed1995

Anatomy of the moose craniomandibular joint (Alces alces, Linnaeus, 1758).

the craniomandibular joints (CMJ) were investigated in 10 Swedish mooses (eight cows: five 1-year-old, two two-year-old, and one 7-year-old) together with one bull moose (2 years) and a yearling. The CMJs, situated at a high distance from the occlusal plane of the tooth rows, comprised a temporal component, a disc and a condyle. The temporal component lacked a mandibular fossa as well as articular eminence. The joint surface was oval, almost flat and convex. The condyle had about two-thirds of its length medio-laterally, cylindrical in shape and from a posterior view medially inclined. The articulating surface was divided into a horizontal part located on the superio-anterior condyle, and a vertical part medially situated. The disc was oval in shape and revealed two synovial chambers totally surrounded by a soft tissue lining.

Animals↗
PubMed1995

Changes in moral reasoning and the teaching of medical ethics.

Courses in medical ethics are becoming an integral part of many medical school curricula in Europe. At the medical school of the University of Copenhagen, a course on philosophy of medicine has been compulsory for all medical students since 1988. The effect of such courses on the ethical awareness and reasoning of medical students is not well understood and we have therefore found it of interest to study the effects of the Copenhagen course. For the study, we used a Danish version of the Defining Issues Test (DIT) which measures development in moral reasoning (Rest J R, 1979 Development in Judging Moral Issues. University of Minnesota Press, Minneapolis). The study was conducted as a pre- and post-test study without a control group, and the subjects were all medical students attending the course in the autumn of 1993. The results show that moral reasoning scores measured by the DIT increase significantly, and we argue that this increase can only be explained as an effect of the course.

Adult↗
PubMed1995

Pulmonary venous systolic flow fraction in patients with mitral regurgitation: transoesophageal echocardiographic findings in relation to haemodynamic and angiographic evaluation.

In patients with mitral regurgitation (MR), pulmonary venous systolic flow fraction (PVSFfr) recorded using pulsed Doppler transoesophageal echocardiography (TEE) was compared with PVSFfr in normal subjects, to angiographic grading and to haemodynamic parameters. PVSfr was calculated as the systolic flow velocity integral divided by total inflow integral. PVSfr is negative when systolic flow is reversed. Forty patients with MR were studied. PVSFfr < 0 was 100% sensitive for angiographic severe MR (specificity 83%). In 35 patents heart rate differed by 10 bpm or less between TEE and cath, either at rest or during stress. PVSFfr was correlated with angiographic grade (r = -0.69, P < 0.0001), with mean PCW (r = -0.61, P < 0.0001), with the v-wave (r = -0.72, P < 0.0001), with systolic blood pressure (r = 0.48, P < 0.005) and with left atrial diameter (r = -0.52, P < 0.005). Stepwise forward multiple linear regression analysis revealed the v-wave, angiographic grading and systolic blood pressure to be independent predictors of PVSFfr. PVSFfr differed in normal subjects, patients with 0-2+ and patients with 3-4+ regurgitation. PVSFfr is a valuable index in assessing mitral regurgitation. This index may be less dependent on equipment and operator than colour flow imaging.

Adult↗
PubMed1995

The effect of zinc on bacterial phagocytosis, killing and cytoprotection in human polymorphonuclear leucocytes.

An in vitro study examining the effects of zinc treatment on human PMN cell phagocytosis and killing of Staphylococcus aureus and Staphylococcus epidermidis and the cytoprotection of zinc against staphylococcal toxins. Phagocytosis was studied by transmission electron microscopy using different microbiological techniques, one of which was designed to follow the kinetics of bacterial killing. No effect was found on phagocytosis and bacterial killing. The cytotoxic effects of a crude toxin and an alpha-toxin extracted from Staphylococcus aureus preparations were studied on human PMN cells using the standard 51Cr release assay. Both toxins induced a dose-dependent leakage of 51Cr, indicating cell membrane damage. These results were confirmed by electron microscopy during the phagocytosis of S. aureus, where severe PMN cellular degeneration was observed. The addition of zinc to PMN cells strongly inhibited the release of 51Cr. In conclusion, our results show that zinc in higher than physiological concentrations does not inhibit PMN cell functions such as phagocytosis and intracellular killing of S. aureus and S. epidermidis. The addition of zinc may be beneficial in certain clinical situations, such as wound healing, zinc deficiency and infections involving toxin-producing bacteria, e.g. S. aureus.

Bacterial Toxins↗
PubMed1995

Not just autonomy--the principles of American biomedical ethics.

The Principles of Biomedical Ethics by Tom L Beauchamp and James F Childress which is now in its fourth edition has had a great influence on the development of bioethics through its exposition of a theory based on the four principles: respect for autonomy; non-maleficence; beneficence, and justice (1). The theory is developed as a common-morality theory, and the present paper attempts to show how this approach, starting from American common-morality, leads to an underdevelopment of beneficence and justice, and that the methods offered for specification and balancing of principles are inadequate.

Beneficence↗
PubMed1995

Heterogeneous cerebral glucose metabolism in normal pressure hydrocephalus.

The regional cerebral metabolic rate for glucose (rCMRglu) has never been investigated in large consecutive groups of patients with normal pressure hydrocephalus (NPH), a potentially treatable form of dementia with an unpredictable outcome after shunt surgery. Using PET and 18F-2-fluorodeoxyglucose, rCMRglu was studied in 18 patients who fulfilled hydrodynamic criteria for NPH and in whom a biopsy of the frontal cortex was obtained. When compared with an age matched group of 11 healthy subjects, the patients with NPH showed a significant rCMRglu reduction in all cortical and subcortical regions of interest. Individual metabolic patterns, however, disclosed a large topographical heterogeneity. Furthermore, histopathological examination identified Alzheimer's disease or cerebrovascular disease in six cases, and no parenchymal disease or non-specific degenerative processes in the remaining 12. After separating the patients according to the histological diagnosis, the rCMRglu patterns were still heterogeneous, the abnormalities ranging from focal to diffuse in both subgroups. After shunt operation, 11 patients did not improve or worsened clinically. Six patients improved; of those, two had Alzheimer changes and two cerebrovascular changes in their biopsy. The metabolic pattern of these six patients did not differ from the rest of the NPH group. The results indicate that the NPH syndrome may be non-specifically associated with different degenerative disorders. The metabolic heterogeneity, together with the heterogeneous histopathological findings, indicate the necessity of reevaluating the pathogenesis of the NPH syndrome, and may account for the high variability in the success rate of shunt surgery series.

Aged↗
PubMed1995

Blood-brain barrier permeability of glucose and ketone bodies during short-term starvation in humans.

The blood-brain barrier (BBB) permeability for glucose and beta-hydroxybutyrate (beta-OHB) was studied by the intravenous double-indicator method in nine healthy subjects before and after 3.5 days of starvation. In fasting, mean arterial plasma glucose decreased and arterial concentration of beta-OHB increased, whereas cerebral blood flow remained unchanged. The permeability-surface area product for BBB glucose transport from blood to brain (PS1) increased by 55 +/- 31%, whereas no significant change in the permeability from brain back to blood (PS2) was found. PS1 for beta-OHB remained constant during starvation. The expected increase in PS1 due to the lower plasma glucose concentration was calculated to be 22% using previous estimates of maximal transport velocity and Michaelis-Menten affinity constant for glucose transport. The determined increase was thus 33% higher than the expected increase and can only be partially explained by the decrease in plasma glucose. It is concluded that a modest upregulation of glucose transport across the BBB takes place after starvation. Brain transport of beta-OHB did not decrease as expected from the largely increased beta-OHB arterial level. This might be interpreted as an increase in brain transport of beta-OHB, which could be caused by induction mechanisms, but the large nonsaturable component of beta-OHB transport makes such a conclusion difficult. However, beta-OHB blood concentration and beta-OHB influx into the brain increased by > 10 times. This implies that the influx of ketone bodies into the brain is largely determined by the amount of ketones present in the blood, and any condition in which ketonemia occurs will lead to an increased ketone influx.

Adult↗
PubMed1995

In vivo measurement of spinal column viscoelasticity--an animal model.

The goal of this study was to measure the in vivo viscoelastic response of spinal motion segments loaded in compression using a porcine model. Nine pigs were used in the study. The animals were anaesthetized and, using surgical techniques, four intrapedicular screws were inserted into the vertebrae of the L2-L3 motion segment. A miniaturized servohydraulic exciter capable of compressing the motion segment was mounted on to the screws. In six animals, a loading scheme consisting of 50 N and 100 N of compression, each applied for 10 min, was used. Each loading period was followed by 10 min restitution with zero load. The loading scheme was repeated four times. Three animals were examined for stiffening effects by consecutively repeating eight times 50 N loading for 5 min followed by 5 min restitution with zero load. This loading scheme was repeated using a 100 N load level. The creep-recovery behavior of the motion segment was recorded continuously. Using non-linear regression techniques, the experimental data were used for evaluating the parameters of a three-parameter standard linear solid model. Correlation coefficients of the order of 0.85 or higher were obtained for the three independent parameters of the model. A survey of the data shows that the viscous deformation rate was a function of the load level. Also, repeated loading at 100 N seemed to induce long-lasting changes in the viscoelastic properties of the porcine lumbar motion segment.

Animals↗
PubMed1995

Is penicillin the appropriate treatment for recurrent tonsillopharyngitis? Results from a comparative randomized blind study of cefuroxime axetil and phenoxymethylpenicillin in children. The Swedish Study Group.

The efficacy of cefuroxime axetil compared with phenoxymethylpenicillin (PcV) was studied in group A beta-haemolytic streptococci (GAS) culture-proven tonsillitis in children aged 3-12 years with a history of at least 1 episode of tonsillopharyngitis requiring antibiotic therapy during the previous 3 months. This was a comparative, randomized, investigator-blind, multicentre study. A total of 236 children received either cefuroxime axetil suspension or PcV syrup. Inclusion criteria were a positive, rapid, group A strep test verified by bacteriological culture and clinical signs and symptoms of tonsillopharyngitis. Cefuroxime axetil treatment gave a significantly higher bacteriological eradication rate and clinical cure rate than PcV. At day 2-5 post treatment the eradication rates were 99/114 (87%) for cefuroxime axetil vs 61/109 (56%) for PcV (p < 0.001). The clinical cure rates were 98/114 (86%) and 73/109 (67%) respectively (p < 0.01). Up to 21-28 days post-treatment, 9/114 (8%) cefuroxime axetil patients and 37/109 (34%) PcV patients were treatment failures or had recurrence/reinfection of GAS tonsillopharyngitis (p < 0.001). More than 90% of the patients who experienced bacteriological treatment failure at either the first or second follow-up had the same serotype isolated pre- and post-treatment. During the study period, 21/114 (18%) patients in the cefuroxime axetil group and 50/109 (46%) patients in the PcV group received additional antibiotics (p < 0.001). No serious adverse events were noted and the mild adverse events were equally distributed among the patients in the 2 study groups: 15% for cefuroxime axetil and 14% for PcV.

Cefuroxime↗
PubMed1995

Bone and wound fluid concentrations of cephalosporins. Oral cefadroxil and parenteral cefuroxime compared in 52 patients with a trochanteric fracture.

We performed a prospective and randomized study in 52 patients to compare the concentrations in cancellous bone and wound fluid of antibiotics, given orally (cefadroxil) or intravenously (cefuroxime) as prophylaxis in trochanteric fracture surgery. Oral cefadroxil resulted in adequate antibiotic levels in 22 of 26 patients in wound fluid and cancellous bone, while parenteral cefuroxime resulted in sufficient antibiotic levels in all 26 patients. The concentrations in bone varied greatly between the subjects.

Administration, Oral↗
PubMed1995

Effects of low-fat milk and fermented low-fat milk on cholesterol absorption and excretion in ileostomy subjects.

OBJECTIVE: To study small bowel cholesterol absorption and sterol excretion in order to explain possible serum cholesterol-lowering mechanisms of low-fat milk products. DESIGN: Two 24-h sterol balance studies with 1 litre of low-fat milk or one litre of fermented milk, in random order, added to a controlled diet. [3H]Cholesterol absorption was measured during each period. The results were compared to those on two 24-h periods with isocaloric amounts of lemonade given to the same basic diet, before and after the study. One litre of the two milk products was also consumed in addition to their normal diets in a cross-over design of 3 weeks and with run-in and run-out periods of 2 weeks each with 1000 ml of lemonade preceding the balance studies: SETTING: Outpatient clinic, where the subjects were eating their meals during the day and ileostomy bags collected. SUBJECTS: Nine ileostomy subjects, who have earlier participated in similar studies, volunteered for the study. All subjects completed the study. RESULTS: Cholesterol absorption was highest (66%) in the lemonade period, intermediate in the low-fat milk period (61%) and lowest in the fermented low-fat period (55%) (P < 0.05 for differences). Net cholesterol excretion (excretion minus intake) and calculated endogenous cholesterol excretion were significantly (P < 0.05 for differences) higher in the low-fat milk period than in the lemonade period and the fermented low-fat milk period. No significant change in serum cholesterol was, however, seen after 3 weeks on each milk regimen. CONCLUSION: Assimilation of cholesterol by microorganisms could possibly explain the reduced uptake of cholesterol with fermented milk. The mechanism behind the increased endogenous cholesterol excretion, induced by low-fat milk, is unclear.

Adult↗
PubMed1994

The prefrontal cortex and variants of sequential behaviour indications of functional differentiation between subdivisions of the rat's prefrontal cortex.

In two separate experiments we addressed the involvement of the rat's prefrontal cortex in mediation of the sequential ordering of the "components of behaviour". In both experiments the animals were required to operate two different and spatially distant manipulanda sequentially. While in the first experiment a light cue signalled which response would at any moment be appropriate no sensory cues offered procedural guidance during the second experiment. Both experiments focused on postoperative retention performance. In the first experiment we studied the consequences of ablation of the dorsal anteromedial cortex, the total anteromedial cortex and the suprarhinal cortex as compared to a sham operated control group. In the second experiment we compared a sham operated group to a group subjected to ablation of the total anteromedial cortex. While the proficiency of task performance was evaluated on the basis of the number of reinforcements obtained and the percentage of bar presses to be reinforced, additional analysis of behaviour included registration of the individual behavioural components and the sequential orders in which these were observed. The major findings were: (1) lesions within the anteromedial, prefrontal cortex (especially if including the ventral part of this region) are associated with significantly impaired performance of both the presently investigated tasks. (2) The demonstrated association between the anteromedial cortex and the mediation of the sequential arrangement of behavioural components does not seem to be secondary to changes in neither quality nor frequency of any individual behavioural component. (3) In the first experiment--where a cue light signalled which response would at any point in time be adequate--lesions within all parts of the prefrontal cortex (the suprarhinal as well as the anteromedial cortex) were associated with overproduction of errors, which in the behavioural sequence analysis had been characterized as "type B". We tentatively interpret such errors as reflecting a failure to utilize the visual cue offered by the signal lamp. Since lesions within all parts of the prefrontal cortex seem to be associated with "cue utilization" failures while only lesions involving the anteromedial cortex are reflected in impaired sequential arrangement of behavioural components the present studies seem to reflect a certain degree of functional specialization within the prefrontal cortex of the rat.

Animals↗
PubMed1994

Collagens in the injured porcine intervertebral disc.

Spinal pain often is thought to be due to degeneration and mechanical failure of the intervertebral disc. Since the mechanical strength of the tissue depends on collagen fibers, the present study was designed to investigate the reactions in collagen metabolism after an experimentally induced disc injury. Five domestic pigs underwent an incision in the anterior part of the annulus fibrosus of disc L4-L5 through a retroperitoneal approach. The animals were killed 3 months postoperatively, and the injured discs and intact discs (controls) from different animals were removed for chemical analysis. Slices were cut from seven different parts across the disc. The concentration of total collagen (hydroxyproline [Hyp]), the activities of the two key enzymes in collagen biosynthesis (prolyl 4-hydroxylase [PH] and galactosylhydroxylysyl glucosyltransferase [GGT]), and the concentration of mature collagen crosslinks (hydroxypyridinium [HP]) were determined. In all experimental discs, the morphology had changed considerably: the nucleus pulposus was small, fibrous, and yellowish. The annular lamellar structure was partially destroyed and had been replaced by granulation tissue in the region of the injury. Large osteophytes had formed at the ventral edges of the vertebral bodies. In the nucleus pulposus, the Hyp concentration and the activities of PH and GGT were significantly increased, whereas the water content had decreased. The concentration of HP crosslinks was decreased in the anterior annulus fibrosus.

Animals↗
PubMed1994

Neural elements in the normal and experimentally injured porcine intervertebral disk.

There is increasing evidence that-back pain may originate from degenerated or damaged disks, even in the absence of disk herniation. For a study of the pattern of innervation in injured disks, the anterior part of the annulus fibrosus of a lumbar disk in 11 domestic pigs was incised with a scalpel through a retroperitoneal approach. The animals were killed 2 weeks, 1, 2, 3, and 5 months postoperatively, and the whole anterior annulus of each injured disk and corresponding tissue from intact animals were excised. Cryostat sections 20 microns thick were cut from the surface downward, fixed, and stained with different antisera. Antisera to neurofilament triplet protein (R39), protein gene product (PGP) 9.5 and synaptophysin were used as general neural markers. Antiserum to substance P (SP) and calcitonin gene-related peptide (CGRP) were used to localize nerves mainly of the sensory type, and C flanking peptide of neuropeptide Y (CPON) to visualize nerve fibers of the sympathetic type. It was observed that in the intact porcine disk, the outer and middle parts of the anterior annulus were innervated to a depth of 7 mm from the annular surface, but the innermost annular layers showed no immunoreactivity to any of the neural antibodies. Disk injury did not cause any major changes in the nerve topography of the wound area, even though there were granulation tissue and neovascularization in this area.

Animals↗
PubMed1994

The human placental immunoglobulin G receptor and immunoglobulin G transport.

OBJECTIVE: The objective of this study was to quantitatively determine an immunoglobulin G receptor, placental alkaline phosphatase, and its ligand immunoglobulin G in maternal and fetal blood and to study the transport capacity of the receptor. STUDY DESIGN: Venous blood samples from 66 term pregnant women and cord samples from their fetuses were obtained, together with the corresponding placentas. RESULTS: Mean placental alkaline phosphatase levels were determined to be 23.7 ng/ml and 1.2 ng/ml in maternal and fetal blood, respectively. Mean immunoglobulin G level of the fetal samples was significantly higher than that of the maternal samples (12.6 vs 9.5 gm/L, p < 0.0001). The placental alkaline phosphatase phenotype S had a larger dissociation constant to immunoglobulin G than did type F and was found to have mean fetal immunoglobulin G levels higher than those of the F type (13.3 vs 9.7 gm/L). CONCLUSION: The placental immunoglobulin G receptor placental alkaline phosphatase is found in the fetal circulation. The placental alkaline phosphatase phenotype was found to be related to the levels of its ligand immunoglobulin G in fetal blood, although the mechanism for this remains to be established. Immunoglobulin G is actively transported to fetal blood to reach higher levels than in the maternal circulation.

Adult↗
PubMed1994

A quantitative histochemical study of the spatial distribution of intrafascicular fibre types in the porcine masseter and soleus muscles.

The distribution of intrafascicular type I and II muscle fibres together with proportions of edge- and centrally located type I and II fibres within whole fascicles were analysed by myosin ATP-ase histochemistry in 241 porcine masseter fascicles (six masseter muscles) and compared with result from 63 pig soleus fascicles (five soleus muscles). All fascicles were from 11 domestic pigs (1 yr old, 70-90 kg body weight, all female). The proportions of type I fibres (slow) and type II fibres (fast) on the edge of fascicles differed significantly from the proportions centrally. All the soleus fascicles had higher proportions of centrally located type I fibres. Only seven out of 241 (3%) masseter fascicles diverged in this respect and showed reversed intrafascicular fibre-type proportions with more edge-located type I fibres. Analysis of the fascicular distribution of type I and II fibres revealed that the porcine masseter had type II fibres as the predominant type. Between 68-87% of the total fibres were type II (p < 0.001). The intrafascicular content of type I fibres increased towards the deep part of the masseter. In four of five soleus muscles the type II fibre population was dominant (p < 0.01). However, one soleus revealed equal proportions of type I and II fibres.

Animals↗