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Biomedical subjects

U L Johnsen

Publications and source records attributed to U L Johnsen.

9 recordsLinked to original sources
PubMed2001

Post-traumatic cerebral infarction. Neuroimaging findings, etiology and outcome.

PURPOSE: To assess the radiological characteristics of post-traumatic cerebral infarctions (PTCIs), the etiology and site of infarction, and to provide neuroimaging indicators of a poor clinical outcome. MATERIAL AND METHODS: A retrospective study of 16 patients with the neuroimaging-based diagnosis of PTCI was carried out. All CT, MR examinations, cerebral angiograms and medical records of the patients were reviewed. RESULTS: Infarcts were diagnosed in the territory of the posterior cerebral artery in 9 patients, in the middle cerebral artery in 5, in the anterior cerebral artery in 3, lenticulostriate-thalamoperforating in 2, vertebrobasilar in 3, and cortical infarcts in 2 patients. Neuroimaging studies suggested focal mass effect and/or acquired intracranial herniations as the cause of infarction in 13/16 patients (81.2%). In 3/16 patients (18.8%), PTCI was due to vascular injury of which 2 were angiographically documented (carotid artery dissection). Eight of the 16 patients in this study died or were left in a persistent vegetative state. Patients with associated subdural hematoma, brain swelling/edema and traumatic subarachnoid hemorrhage (tSAH) exhibited the worst outcome. CONCLUSION: Gross mechanical shift of the brain and herniation across the falx and/or tentorium accounted for infarction in a majority of cases in our study. The overall death rate was 43.8% and this result suggests that PTCI is an indication of a poor clinical outcome, especially among patients with associated subdural hematoma, brain swelling/edema and tSAH.

Adolescent↗
PubMed1997

[Computer tomography of pathological neck lesions].

The introduction of high resolution computed tomography (CT) has significantly improved the quality of imaging of neck masses. Incremental dynamic scanning immediately after a quick bolus injection of contrast medium is essential in a majority of patients in order to obtain an optimum of information. This is especially true in the identification, mapping and staging of malignant lesions, which is the main indication for the examination. CT is also very sensitive, and yields detailed information about the location and extent of cystic and other benign lesions. Owing to the low attenuation of fat, the examination is very specific with respect to lipomas. CT has low specificity in the differentiation between benign and malignant lesions, and between cysts and solid tumours of the thyroid gland. In thyroid and parathyroid imaging other modalities such as ultrasound and scintigraphy are often more specific.

Head and Neck Neoplasms↗
PubMed1996

Randomised, double blind, placebo controlled trial of penicillin V and amoxycillin in treatment of acute sinus infections in adults.

OBJECTIVES: To compare the effectiveness of penicillin V and amoxycillin with placebo in treatment of adult patients with acute sinusitis. DESIGN: Randomised, double blind, placebo controlled trial. SETTING: Norwegian general practice. SUBJECTS: 130 adult patients with a clinical diagnosis of acute sinusitis confirmed by computed tomography. MAIN OUTCOME MEASURES: Subjective status after three and 10 days of treatment, difference in clinical severity score between day 0 and day 10 as evaluated by the general practitioner, difference in score from computed tomography on day 0 and day 10, and duration of sinusitis. RESULTS: Amoxycillin and penicillin V led to significantly faster and better recovery than placebo. By day 10, 71 patients receiving antibiotic treatment- (86%) considered themselves to be recovered or much better compared with 25 (57%) receiving placebo. The mean (95% confidence interval) reductions in clinical severity scores by day 10 were 5.4 (5.0 to 5.8) for penicillin V, 5.5 (4.9 to 6.0 for amoxycillin, and 3.4 (2.8 to 4.0) for placebo. For the antibiotic groups combined the number of patients with the greatest degree of improvement on computed tomography (scale 0-16)-that is, score 5-16 on day 10-was 31/83 (37%) compared with 10/44 (23%) receiving placebo. The median duration of the sinusitis was nine days in the amoxycillin group, 11 days in the penicillin V group, and 17 days in the placebo group. CONCLUSION: Penicillin V and amoxycillin are significantly more effective than placebo in the treatment of acute sinusitis.

Acute Disease↗
PubMed1996

CT findings in general practice patients with suspected acute sinusitis.

PURPOSE: To study CT findings in general practice patients with a clinical diagnosis of acute sinusitis, and to examine the interobserver variation between 2 radiologists with regard to their CT evaluation. MATERIAL AND METHODS: Two hundred and one patients were examined with coronal CT images of the paranasal sinuses within 2 days of the clinical diagnosis. Patients with chronic sinusitis were excluded. Fluid level or total opacification of any sinus were used as evidence of sinusitis. RESULTS: One hundred and twenty-seven (63%) patients had fluid level or total opacification in a sinus region, most in more than one region. One hundred and fifteen had CT signs of sinusitis in the ethmoid region, 84 in the maxillary, 18 in the frontal, and 10 in the sphenoid. Forty-nine patients had a negative Ct. In the evaluation of interobserver agreement, the overall assessment of the CT yielded a kappa value of 0.70. CONCLUSION: The study demonstrated great variation in the CT findings in general practice patients with suspected acute sinusitis. More than one sinus region was affected in most patients in whom sinusitis was confirmed by CT imaging; the most common combination was ethmoid and maxillary sinuses. The interobserver agreement was substantial.

Acute Disease↗
PubMed1996

Use of symptoms, signs, and blood tests to diagnose acute sinus infections in primary care: comparison with computed tomography.

OBJECTIVES: This study evaluated different symptoms, signs, and blood tests in the diagnostic process of patients with a clinical diagnosis of acute sinusitis. METHODS: A total of 201 primary care patients in southern Norway aged 15 years or older with a clinical diagnosis of acute sinusitis were evaluated. Computed tomography (CT) was used as a reference standard to divide the patients into two groups: one with and one without confirmed sinusitis. Fluid level or total opacification of any sinus on CT were used as hallmarks of confirmed sinusitis. Blood tests that included erythrocyte sedimentation rate (ESR), C-reactive protein, and white blood count were taken. The patients were evaluated in a standardized way for the medical history and the clinical investigation. RESULTS: A total of 127 (63%) patients had fluid level or total opacification in one or more sinus regions. "Double sickening," purulent rhinorrhoea, purulent secretion in cavum nasi, and ESR > 10 had the highest likelihood ratios and were independently associated with acute sinusitis. CONCLUSIONS: This study confirms the uncertainty of the clinical diagnosis of acute sinusitis in primary care, based on the clinical evaluation alone. Only four symptoms and signs had a high likelihood ratio and were independently associated with acute sinusitis. A combination of at least three of these four symptoms and signs gave a specificity of .81 and a sensitivity of .66.

Acute Disease↗
PubMed1995

Differentiation between contained and noncontained lumbar disk hernias by CT and MR imaging.

AIMS: The investigation was carried out in order to compare the accuracy of CT and MR imaging in depicting whether disk hernias were contained by the posterior longitudinal ligament (PLL). This is crucial in the evaluation of patients who are possible candidates for percutaneous nucleotomy, which is considered effective only in contained hernias. RESULTS: Of 124 pathologic disks examined in 114 patients, CT was more accurate than MR imaging in 7 patients due to misinterpretation of the integrity of the PLL by MR. These hernias were therefore erroneously classified as noncontained. There was consistency between the classification by CT and MR imaging in the other 117 disks, of which 109 were correct. Both methods overstaged a large hernia that was contained by the PLL, and failed to demonstrate that 7 others were noncontained. CONCLUSIONS: CT, which has higher sensitivity in depicting calcifications, representing further contraindications to percutaneous nucleotomy, is therefore recommended as the primary examination in these patients. Additional MR imaging should be considered if the results of CT are equivocal or at variance with the clinical presentation.

Adolescent↗
PubMed1983

Platelets stimulate thromboplastin synthesis in human endothelial cells.

Human umbilical vein endothelial cells in culture synthesize thromboplastin upon stimulation with phytohaemagglutinin (PHA) or the tumor promotor 12-O-tetradecanoyl-phorbol-13-acetate (TPA). The thromboplastin activity is further strongly enhanced in a time dependent reaction by the presence of gel-filtered platelets or platelet aggregates. This effect was demonstrable at platelet concentrations lower than those normally found in plasma, it may thus be of pathophysiological relevance. The thromboplastin activity increased with increasing number of platelets added. Cycloheximide inhibited the increase, suggesting that de novo synthesis of the protein component of thromboplastin, apoprotein III, is necessary. When care was taken to remove monocytes no thromboplastin activity and no apoprotein III antigen could be demonstrated in suspensions of gel-filtered platelets, platelets aggregated with thrombin or homogenized platelets when studied with a coagulation assay and an antibody neutralization technique.

Blood Platelets↗