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Biomedical subjects

S Larsen

Publications and source records attributed to S Larsen.

At least 325 records · Page 18Linked to original sources
PubMed1986

Pathogenicity and persistence of pleural effusion disease virus isolates in rabbits.

Nine isolates of pleural effusion disease agent or virus (PEDV) from treponema-infected rabbits in various countries were examined for pathogenicity and persistence in rabbits. The isolates showed a wide range of pathogenicity and were categorized into three groups according to the severity of the acute infection. Group 1 comprised isolates causing more than 50% mortality, group 2 isolates causing mortality below 50%, while group 3 comprised isolates causing almost subclinical infections. The range between group 1 and group 3 was similar to that observed with virulent and avirulent progeny of the original PEDV isolate. Infection by each of the nine isolates resulted in a chronic low level viraemia which persisted for up to 2 years or more. Viral progeny of pathogenic isolates obtained in serum after the 2nd month of infection failed to induce clinical disease on rabbit inoculation. The chronic, subclinical infection was associated with a moderate, continued increase in serum IgG, but circulating immune complexes could not be demonstrated. Two years after infection slight histopathological changes were present in lymph nodes, spleen, liver, heart and lung. Evidence of immune complex disease could not be demonstrated.

Animals↗
PubMed1986

Lithium: long-term effects on the kidney. I. Renal function in retrospect.

46 patients treated with lithium for an average of 8 years participated in a functional-morphological follow-up study based on a 12-day hospitalization and involving a kidney biopsy. The functional part of the study showed that tubular function was markedly influenced, leading to increased urine volume (average 3 1/24 h) and a decreased renal concentration capacity in 85% of the patients. Glomerular function was generally not influenced, and only 10% of the patients had glomerular filtration rates below their age-corrected normal ranges. Both urine volume and glomerular filtration rates showed significant correlations with dosage schedule. Urine volume was lower and glomerular filtration rate higher on a one-dose schedule than when lithium was given in divided doses during the day. It is concluded that discontinuity in lithium treatment minimizes lithium effects on kidney function.

Adult↗
PubMed1986

On the role of platelets and leucocyte in renal xenoperfusion.

Five rabbit kidneys were perfused with heparinized human blood, five with platelet-rich, leucocyte-poor blood, five with platelet-poor, leucocyte-rich blood, and five with platelet-poor, leucocyte-poor, heparinized human blood. The kidneys were perfused at a constant pressure of 80 mm Hg and the time until the flow decreased to 2 ml/min was determined. Removal of platelets from the blood significantly delayed rejection. The effect of removing leucocytes was insignificant. Morphologically all groups revealed platelet aggregates, endothelial damage and ischemic changes of distal tubular epithelium.

Animals↗
PubMed1986

The effect of glucagon, glucagon-(1-21)-peptide, and placebo on duodenal pressure activity in healthy subjects.

The effects of glucagon and the glucagon-(1-21)-peptide on the duodenal pressure activity in 12 healthy subjects were studied and compared with those of placebo. A 1-mg bolus injection of either glucagon or glucagon-(1-21)-peptide was given at the end of the first interdigestive migrating complex, followed by intravenous infusion of 2 mg of each drug during the subsequent 2 h. Both glucagon and glucagon-(1-21)-peptide caused significant change (p less than 0.05) in the duodenal pressure activity, as the length of the cycle was significantly increased and the migrating motor complexes were significantly reduced. The frequency of side effects and the degree of discomfort during the recordings were significantly higher (p less than 0.01) in the glucagon period than in both the glucagon-(1-21)-peptide and the placebo periods. No differences in side effects and discomfort between glucagon-(1-21)-peptide and placebo were detected. Glucagon caused a significant increase in both serum glucose and insulin levels (p less than 0.01).

Adult↗
PubMed1986

Human gastric blood circulation evaluated by endoscopic laser Doppler flowmetry.

Endoscopic laser Doppler flowmetry was used to study gastric blood circulation in 34 healthy subjects. This paper presents the results of methodological studies and blood flux measurements in different parts of the stomach. In the recorded curve the flux level was easy to define, even though fluctuations synchronous with heart beat, respiration, and peristalsis were visible. The temporal and spatial variations of recorded values were within acceptable limits. Angulation between the measuring probe and mucosa and moderate pressure of the probe against the gastric wall did not seem to influence the recorded values significantly. When the blood circulation was examined in different parts of the stomach, the values along the lesser curvature were significantly lower than the values along the greater curvature (p less than 0.01).

Adult↗
PubMed1986

The effect of ranitidine on the gastroduodenal motility as determined by the maximal pressure periods.

Twenty healthy subjects with a mean age of 23.5 years were studied. Identically appearing tablets of 150 mg ranitidine or placebo were given to each subject twice daily for 2 days. After an overnight fast the same dosage of tablets was given 2 h before introduction of two fiberoptic transducers, the tips of which were localized to the mid-portion of the gastric antrum and the upper third of the duodenum. The double-blind crossover study showed in the placebo period a mean duration of the maximal pressure periods (MPP) of 5.5 min in the duodenum and 3.5 min in the antrum of the stomach. The cyclic length (CL) and the cyclic displacement (CD) in the duodenum were 58 min and 67 mm/min, respectively. After ranitidine the duration of the MPP was significantly longer. The CL was also longer in the duodenum, whereas the CD was shortened, indicating a reduction of the wave movements from the stomach antrum to the duodenum in the ranitidine periods.

Adolescent↗
PubMed1986

Epidemiology of polyps in the rectum and sigmoid colon. Discriminant analysis for identification of individuals at risk of developing colorectal neoplasia.

In an endoscopic population screening examination for detection of colorectal polyps among 324 men and women aged 50-59 years, adenomas greater than or equal to 5 mm in diameter were found in 38 individuals, and 212 were polyp-free. Dietary registration was performed by 155 individuals on a case/control basis. At 2 years' follow-up study polyps less than 5 mm in diameter were also removed. This rendered a total of 39 adenoma patients and 59 polyp-free individuals available for a combined analysis of both case history and dietary information. Application of a linear discriminant model on the combined clinical and dietary information enabled us to select a possible set of variables to characterize 88 out of 98 individuals (90%) correctly as adenoma patients or polyp-free individuals. However, when only case history information was used for the total material of 38 adenoma patients and 212 polyp-free individuals, only 189 out of 250 individuals (76%) were correctly classified. Although age, smoking habits, and a family history of colorectal cancer appeared as useful variables in the discriminant function, this study demonstrated the importance of nutritional factors in characterization of adenoma patients in the present age group of 50-59 years. In the present study we could not find any set of case history information which could indicate the usefulness of a questionnaire-based 'pre-screening' to guide recommendations for endoscopic screening examination.

Colonic Polyps↗
PubMed1986

Epidemiology of polyps in the rectum and colon. Recovery and evaluation of unresected polyps 2 years after detection.

In an endoscopic population screening study for colorectal polyps among 200 men and 200 women, 50-59 years of age, 215 polyps less than 5 mm in diameter were left in situ for the present 2-year follow-up examination. The attendance rate was 102 of 106 (96%) for polyp patients and 77 of 90 (86%) in the control group. Of 194 polyps, 143 (74%) in the 102 polyp-bearing individuals were recovered for histological evaluation and 57 polyps were registered as new. Ninety-nine (50%) of the polyps were hyperplastic, 45 (23%) were adenomas, and 45 (23%) were mucosal tags. Both growth and regression of polyps were registered. Regression was commoner in the distal part of the rectum than in the proximal part or distal sigmoid colon. Growth was similar for recovered adenomas and hyperplastic polyps, whereas mucosal tags more often showed diminution in size. No polyp had reached a size of more than 5 mm in 2 years, and no case of severe dysplasia or carcinoma was registered. The estimated total polyp mass more than doubled both for adenomas and hyperplastic polyps. It is concluded that the time interval between initial examination with removal of polyps 5 mm or larger in diameter and the first follow-up examination may safely be set at 2 years.

Colonic Polyps↗
PubMed1986

Epidemiology of polyps in the rectum and sigmoid colon. Evaluation of nutritional factors.

Epidemiological studies have suggested an association between diet and colorectal cancer. Case/control studies, however, have been scarce, and studies based on interview with cancer patients who have symptoms from their cancer are inevitably prone to bias. An endoscopic population screening study for detection of colorectal adenomas enabled a double-blind registration of diet during 5 consecutive weekdays. Neither the participant nor the dietitian was informed of the findings at endoscopy. The estimation of 23 nutritional components was based on analysis of local commercial food and on the composition of foods in Norway. Results showed increasing consumption of fat and decreasing consumption of fiber and cruciferous vegetables in the presence of increasing neoplastic changes. The present material will form the basis for dietary-related follow-up studies.

Colonic Neoplasms↗
PubMed1986

Bladder tumour control by abdominal ultrasound and urine cytology.

A blind study comparing abdominal ultrasound and cystoscopy was carried out in 186 patients. 20 bladder tumours sized from 2 to 5 mm were overlooked. Combination with urine cytology increased the diagnostic sensitivity. In order to reduce costs and patient inconvenience in the bladder tumour control population abdominal ultrasound and urine cytology is advocated as an alternative to cystoscopy. This control modality seems safe in patients with "low-risk" bladder tumour disease.

Cystoscopy↗
PubMed1986

Prognosis in glomerulonephritis. II. Regression analyses of prognostic factors affecting the course of renal function and the mortality in 395 patients. Calculation of a prognostic model. Report from a Copenhagen study group of renal diseases.

The course of the renal function and mortality were analysed in 395 patients with biopsy-proven glomerulonephritis (GN), using Cox's proportional hazards model. Seventeen clinical, biochemical and histopathological parameters were analysed for prognostic information. The patients were grouped according to their serum creatinine levels. Increase in serum creatinine, decrease in serum creatinine, cure and death were used as endpoints for the analysis. Caplan Meyer curves were made for 7 transitions between different groups and the variables were reduced by a step-wise procedure to a final model. Thirteen of the variables considered offered significant prognostic information (p less than 0.05) for at least one of the transitions. Short duration of disease, young age, non-nephritic urinary sediment and preceding streptococcal infection were predictors of cure. Extracapillary, membranoproliferative and unclassifiable GN, old age and arterial hypertension predicted increase in serum creatinine in patients with low serum creatinine, while male sex, short duration of disease and pathological electrocardiogram favoured a further increase in patients with high serum creatinine. A later decrease in serum creatinine was signified by a preceding streptococcal infection, short duration of disease, absence of arterial hypertension and low urinary protein excretion. Death without uremia was predicted by high age, connective tissue disease and extracapillary GN. Using these parameters and the models, it is possible to make a prognostic forecast for the individual GN patient. Examples of such a forecast are described.

Adult↗
PubMed1985

Norepinephrine kinetics during insulin-induced hypoglycemia.

Norepinephrine (NE) kinetics (plasma appearance rate, clearance, and forearm extraction) were measured during insulin-induced hypoglycemia in six healthy subjects. NE clearance did not change during hypoglycemia, indicating that the increase in plasma NE during hypoglycemia is due to an increased plasma appearance rate of NE. Forearm extraction of 3H-NE and of endogenous plasma epinephrine decreased significantly during hypoglycemia, probably due to an increase in regional blood flow.

Adult↗
PubMed1985

Ultrasonically guided fine needle aspiration biopsy of renal masses.

A consecutive series of 301 ultrasonically guided fine needle aspiration biopsies of renal masses was reviewed. The retrieval rate was 95 per cent and a correct cytological diagnosis was established in 82 per cent of the cases. There were 14 false positive aspirates, for a predictive value of a malignant aspirate of only 93 per cent. All false positive results were misinterpreted as relatively well differentiated adenocarcinoma. We conclude that renal fine needle aspiration biopsy may add information but the risk of a false positive finding must always be considered.

Biopsy, Needle↗
PubMed1985

Carbamazepine therapy in restless legs. Discrimination between responders and non-responders.

One hundred and seventy-four patients suffering from restless legs were included in a double-blind trial. Eighty-four patients were treated with carbamazepine (CBZ) and 90 with placebo. Discrimination analysis was carried out in order to characterize the patients who did not benefit from the treatment. Patients treated with CBZ were divided into responders and non-responders. A discriminant function classified 15 out of 19 actual non-responders as non-responders and 60 out of 65 actual responders as responders. By using the "leaving-one-out" technique, 14 of the non-responders and 57 of the responders were still correctly classified. The probability of erroneously classifying a patient increased from about 10 to 15% by this correction. The discriminant function classified approximately 80% of the patients in the placebo group as responders to CBZ.

Adult↗
PubMed1985

Plasma clearance of noradrenaline does not change with age in normal subjects.

Noradrenaline kinetics (plasma concentrations, plasma clearance and appearance rates) were investigated in seven elderly healthy subjects and in six young healthy subjects. Forearm venous plasma noradrenaline concentrations were higher in the elderly subjects compared with the young subjects. Plasma clearance of noradrenaline was identical in the two groups. The increase in plasma noradrenaline concentration, with age, probably reflects an increased sympathetic nervous activity.

Adult↗