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Biomedical subjects

L Persson

Publications and source records attributed to L Persson.

At least 91 records · Page 5Linked to original sources
PubMed1997

Fusion or stabilization alone for acute distractive flexion injuries in the mid to lower cervical spine?

Long-term pain problems and residual restricted mobility were evaluated for patients sustaining acute distractive flexion injuries to the cervical spine. To assess which of two alternative surgical approaches gives better long-term outcomes, 58 patients were studied, 29 in each group. The results of posterior wire stabilization without fusion according to Brandt were contrasted with those of the Cloward technique. We found significantly more late pain problems and restricted neck mobility in the group treated with wiring without fusion than in those managed with anterior fusion. We conclude that this continuing pain may be due to residual mobility in the damaged degenerated non-fused motion segment, and that the difference between the two groups may reflect the difference in the quality and rate of fusion achieved by the two surgical approaches.

Adolescent↗
PubMed1997

EBIC-guidelines for management of severe head injury in adults. European Brain Injury Consortium.

Guidelines for the management of severe head injury in adults as evolved by the European Brain Injury Consortium are presented and discussed. The importance of preventing and treating secondary insults is emphasized and the principles on which treatment is based are reviewed. Guidelines presented are of a pragmatic nature, based on consensus and expert opinion, covering the treatment from accident site to intensive care unit. Specific aspects pertaining to the conduct of clinical trials in head injury are highlighted. The adopted approach is further discussed in relation to other approaches to the development of guidelines, such as evidence based analysis.

Adult↗
PubMed1997

Survivors of acute leukaemia and highly malignant lymphoma--retrospective views of daily life problems during treatment and when in remission.

Fifty-four former patients, in remission after acute leukaemia or highly malignant lymphoma, responded to a questionnaire covering their physical problems, their view of the help they received, who was most helpful to them during the treatment phase, and the impact of the disease and treatment on their current life. Energy loss and nutritional problems were most troublesome during the treatment phase, signifying many other physical problems. Patients with acute leukaemia had more problems, and thought the care was worse than did patients with highly malignant lymphoma. Serious physical problems correlated with low satisfaction with practical help received, indicating that the nurses failed to meet the needs of those suffering the most. Reduced psychological and sexual energy persisted in remission, showed no correlation with the extent of physical problems during the treatment phase, but correlated with co-existing problems and sensitivity to infections, with a great need for intimate help and counselling and with a low sense of coherence. Family relationships were said to have improved, while work and finances were negatively affected. The results indicate that nursing care should actively focus on physical problems, especially on energy loss and nutritional problems. The overwhelming fatigue hinders patients in taking physical care of themselves, and may be overlooked by the nurse since their motor capability seems intact. The long-term effect of the illness means a reduced psychological and sexual energy and a high degree of existential problems and sensitivity to infections, which indicates the importance of follow-up care, and perhaps especially of counselling for the long-term reactions and disturbance of equilibrium.

Activities of Daily Living↗
PubMed1997

Ethical issues in radiation protection.

In this note the authors survey existing international radiation-protection recommendations of the ICRP, the IAEA, and the ILO. After outlining previous work on the ethics of radiation protection and risk assessment/management, the authors review ethical thinking on five key issues related to radiation protection and ethics. They formulate each of these five issues in terms of alternative ethical stances: (1) Equity vs. Efficiency, (2) Health vs. Economics, (3) Individual Rights vs. Societal Benefits, (4) Due Process vs. Necessary Sacrifice, and (5) Stakeholder Consent vs. Management Decisions.

Compensation and Redress↗
PubMed1997

Impact on clinical outcome of secondary brain insults during the neurointensive care of patients with subarachnoid haemorrhage: a pilot study.

OBJECTIVE: To analyse the occurrence and influence on outcome of secondary brain insults during neurointensive care of patients with subarachnoid haemorrhage. METHODS: Sixty one seriously ill patients with subarachnoid haemorrhage with a poor neurological grade, acute hydrocephalus, or intraventricular and/or intracerebral haemorrhages, who were referred as emergency cases to the neurosurgical intensive care unit during 1990 and 1991, comprised the study patients. RESULTS: The follow up performed according to the Glasgow outcome scale 14 months (median) later showed 23 patients with good recovery (38%), 11 with moderate disability (18%), seven with severe disability (11%), and two in a vegetative state (3%); 18 patients had died (30%). Clinical outcome was significantly related to the CT modified Hunt and Hess grade (P = 0.006). In total, 164 secondary brain insults (potentially avoidable factors) of various types were seen at the unit during the first seven days after the haemorrhage. Patients with a favourable outcome had significantly fewer secondary insults than patients with an unfavourable outcome (P = 0.0008). The occurrence of insults in each patient was related to the neurological grade (CT modified Hunt and Hess grade, P = 0.05). Multivariate analysis with the CT modified Hunt and Hess grade and the number of secondary brain insults during the first week as explanatory variables and favourable outcome as the dependent variable, showed that the number of complications was a significant independent predictor of favourable outcome (beta = -0.38, SE(beta) = 0.17, P = 0.03), whereas the CT modified Hunt and Hess grade did not reach significance (beta = -1.2, SE(beta) = 0.81, P = 0.14). CONCLUSIONS: The clinical outcome after subarachnoid haemorrhage is at least partly determined by the number of secondary insults. Therefore, vigorous attempts should be made to avoid all events that may potentially increase the risk of secondary cerebral ischaemia. Prospective studies must be initiated to define the role of "priming" of the brain and the impact of specific individual secondary insults in patients with subarachnoid haemorrhage.

Adult↗
PubMed1997

Dietary influence on some proposed risk factors for colon cancer: fecal and urinary mutagenic activity and the activity of some intestinal bacterial enzymes.

This investigation studied the effects of a shift from a well-balanced mixed diet to a lacto-vegetarian diet on the mutagenic activity in urine and feces and on some cancer-associated bacterial enzymes in human feces (beta-glucuronidase, beta-glucosidase, and sulphatase). Three months after the shift to the lacto-vegetarian diet, there was a significant decrease in mutagenic activity in urine and feces, beta-glucuronidase, beta-glucosidase, and sulphatase per gram feces wet weight. In contrast, the fecal mutagenic activity and the enzyme activities remained unchanged if expressed per daily output. However, the urinary mutagenic activity expressed as total daily output decreased. Part of the explanation for the decreased fecal mutagenic activity and the decreased enzyme activities is obviously a dilution effect, because much of the increased fecal weight after the shift in diet was associated with a higher water content.

Adult↗
PubMed1996

Regulation of ornithine decarboxylase and S-adenosylmethionine decarboxylase in a polyamine auxotrophic cell line.

In the present study we have examined the regulation of the polyamine biosynthetic pathway in a cell line deficient in ornithine decarboxylase (ODC) activity. These cells were unable to grow unless polyamines were provided in their growth medium. Seeding the cells in the absence of polyamines rapidly resulted in a cellular depletion of putrescine and spermidine. Although the cells were devoid of ODC activity they were demonstrated to express an inactive ODC which was feedback regulated by polyamines in a normal manner. Cells seeded in the absence of polyamines exhibited a marked increase in ODC synthesis rate which was not correlated with an equal change in the ODC mRNA level. The synthesis of S-adenosylmethionine decarboxylase (AdoMetDC) was also increased in the cells seeded in the absence of polyamines. However, this increase was essentially explained by a change in the amount of AdoMetDC mRNA. The addition of putrescine to the growth medium appeared to stimulate the conversion of AdoMetDC proenzyme into its two subunits, indicating a physiological role of putrescine in the regulation of AdoMetDC expression.

Adenosylmethionine Decarboxylase↗
PubMed1996

Simultaneous intracerebral microdialysis and positron emission tomography in the detection of ischemia in patients with subarachnoid hemorrhage.

Intracerebral microdialysis (MD) was applied in patients with subarachnoid hemorrhage. The regional CBF, the CMRO2, and oxygen extraction ratio (OER) were measured with simultaneous positron emission tomography (PET). The aim was to directly correlate alterations in dialysate levels of energy-related metabolites (lactate, lactate/pyruvate ratio, hypoxanthine) and excitatory amino acids (EAAs) (glutamate and aspartate) to the energy state in the MD probe region as determined by PET. Regional ischemia was defined according to Heiss et al. and Lassen (Heiss et al., 1992; Lassen, 1966). Whole-brain ischemia was considered present when the OER for the whole brain exceeded the mean whole-brain OER + 2 SD of six reference patients. In general, the presence of whole-brain ischemia and/or regional ischemia within the region of the MD probe was associated with increased levels of energy-related metabolites and EAAs retrieved by MD. Increased levels of energy-related metabolites and EAAs were only occasionally seen when PET did not show any signs of ischemia or when signs of regional ischemia were found remote from the MD probe region. Thus, the energy-related metabolites and EAAs may be used as extracellular "markers" of ischemia. PET may be of use in defining critical ischemic regions (tissue at risk) where the MD probe can be inserted for chemical monitoring.

Aged↗
PubMed1996

Hyaluronan in human cerebrospinal fluid.

We studied the concentration of hyaluronan in cerebrospinal fluid (CSF) in various diseases and attempted to define its reference interval. A radioassay utilizing cartilage proteins with affinity for hyaluronan was used in determining the concentration of 200 lumbar and 27 ventricular CSF specimens and 11 brain cyst fluids. Molecular weight distributions were determined by gel chromatography and localization in brain tissue by histochemistry. The hyaluronan level of lumbar CSF showed an increase with age; comparatively healthy children had (mean +/- SD) 50 +/- 41 micrograms/L (n = 40) and adults 166 +/- 77 micrograms/L (n = 9); i.e. significantly different values. The highest level was recorded in a patient with meningitis (> 8000 micrograms/L). More than 4000 micrograms/ L was noted in a patient with tumour metastasis in the cerebellum. Significantly elevated levels were especially found with spinal stenosis, head injury and cerebral infarction, but also in inflammatory medical disorders, hydrocephalus and encephalitis. We found no significant increase in multiple sclerosis and some other neurological diseases. Ventricular CSF of adults contained significantly less hyaluronan (53 +/- 73 micrograms/L; n = 16) than lumbar CSF. Hyaluronan in cyst fluids varied from 31 to 25,000 micrograms/L. Weight average molecular weight of hyaluronan in CSF was 2.9-3.0 x 10(5) and in brain tumour cyst fluid 2.4 x 10(6). In search for the origin of hyaluronan in CSF it was found that its concentration in the choroid plexus and leptomeninges was low, but that hyaluronan was accumulated in the superficial layer of the cerebral cortex. Continued screening for hyaluronan in CSF may be valuable in cases of inflammatory diseases, tumours and obstruction to CSF flow.

Adolescent↗
PubMed1996

Comparison between activation of ornithine decarboxylase and histidine decarboxylase in rat stomach.

We compared the responses of rat stomach ornithine decarboxylase (ODC) and histidine decarboxylase (HDC) to food intake, oral treatment with antisecretagogues, NaHCO3, and hypertonic NaCl, antrectomy, intravenous infusion of gastrin-17, the selective cholecystokinin (CCK)-B/gastrin receptor antagonist L-365,260, and the somatostatin analogue RC-160. The serum gastrin concentration and oxyntic mucosal ODC and HDC activities were higher in freely fed rats than in fasted rats. Food intake in fasted rats raised the serum gastrin concentration and the ODC and HDC activities. Ranitidine, omeprazole, and NaHCO3 raised the serum gastrin concentration and activated ODC and HDC. Hypertonic NaCl raised the ODC activity 200-fold, whereas circulating gastrin and HDC activity were increased only moderately. Infusion of gastrin-17 activated HDC but not ODC. L-365,260 prevented the activation of HDC but not of ODC in response to food intake and treatment with omeprazole, NaHCO3, or hypertonic NaCl. Antrectomy prevented the food- and omeprazole-evoked rise in oxyntic mucosal HDC activity but not the rise in ODC activity. RC-160 suppressed HDC activity after food intake and treatment with omeprazole, NaHCO3, or NaCl. In contrast, RC-160 suppressed omeprazole- and NaHCO3-evoked ODC activation but not that evoked by food intake or NaCl. The results support the view that HDC in the oxyntic mucosa is activated by gastrin and suppressed by somatostatin. The induction of ODC is not mediated by gastrin; ODC activation appears to be related to acid inhibition per se or to mucosal maintenance and repair; somatostatin, or rather the lack of it, might contribute to the induction of ODC after acid blockade. The mechanism behind the activation of rat stomach ODC seems to differ depending on the type of stimulus.

Analgesics↗
PubMed1996

Lung Function in Woodworking Teachers in Sweden.

Work-related airways symptoms are common in woodworkers. To study possible work-related effects on lung function, 40 exposed woodworking teachers and 31 controls were examined by spirometry, diffusion-capacity and nitrogen-washout determinations, and methacholine challenge. Measured levels of total and respirable dust and terpene concentrations in the shops were below the Swedish threshold-limit values. Lung-function values on Monday morning were similar in the two groups. Slight obstructive impairments during the working week were found in both groups. In the woodworking teachers, small changes in lung function were related to measured total dust, use of process ventilation, and use of a broom to clean the benches. Their methacholine reactivity was slightly more pronounced compared with that of the controls, but the numbers of hyperreactive individuals (PC&inf20; < 8 mg/m(3)) were equal in the two groups. These facts might indicate small work-related effects on lung function, but some contradictory findings disturb this interpretation. The results are therefore inconclusive.

Journal Article↗
PubMed1996

Pierre Auger--a life in the service of science.

A short biography of Pierre Auger, the discoverer of the atomic auger electron effect, is given. Professor Auger's outstanding professional career covered physics, nuclear power and space research, organization and administration of research, diplomatic services and pedagogics but also extended into modern biology, humanistic sciences, poetry and arts. Part of a speech in Paris of professor Auger held in 1989 on the theme 'Research and Creativity' at an international symposium on the auger effect is included in this biography as well as one of his poems.

Biophysics↗
PubMed1996

Neurochemical monitoring using intracerebral microdialysis in patients with subarachnoid hemorrhage.

The authors have developed a method for routine monitoring of disturbances in brain energy metabolism and extracellular levels of excitatory amino acids using intracerebral microdialysis in 10 patients with subarachnoid hemorrhage. Microdialysis was conducted for periods ranging from 6 to 11 days after ictus. Altogether, 16,054 chemical analyses from 1647 dialysate samples were performed. Concentrations of the energy-related substances lactate, pyruvate, glucose, and hypoxanthine were measured, and the lactate/pyruvate ratio was calculated. The excitatory amino acids glutamate and aspartate were measured. The microdialysis data were matched with computerized tomography findings, clinical course, and outcome. The results support the concepts that microdialysis is a promising tool for chemical monitoring of the human brain and that extracellular fluid levels of lactate, lactate/pyruvate ratio, glucose, hypoxanthine, and glutamate are useful markers of disturbances in brain energy metabolism in neurointensive care patients. These results have generated a working hypothesis that the pattern of these extracellular markers may help differentiate between various causes of energy perturbations, such as hypoxia and different degrees of ischemia. The correlation between the dialysate levels of excitatory amino acids and outcome supports the concept of glutamate receptor overactivation in acute human brain injury.

Aged↗