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Biomedical subjects

L Olsen

Publications and source records attributed to L Olsen.

125 records · Page 7Linked to original sources
PubMed1976

Renal function in experimental chronic hydronephrosis. IV. Renal handling of sodium and water.

The reabsorption and excretion of sodium, chloride, potassium and water were investigated subsequent to loading with saline solution before and after unilateral hydronephrosis with partial obstruction to flow had been induced in 23 dogs by ligation of the ureter over an indwelling catheter. In the experimental kidney the increase in the total excretion of sodium and chloride and of water in per cent of GFR and the decrease in the reabsorption of sodium, chloride and potassium in per cent of the filtered loads were statistically significant. The glomerulotubular balance was altered statistically probably significantly, but the relation between the capacities for reabsorption of sodium and glucose was maintained. The renal pelvic dilatation was measured and plotted against the degree of renal functional impairment. A statistically significant inverse correlation was noted between renal pelvic volume and reabsorption of sodium and of chloride in per cent of the filtered loads. The osmolality of the urine was the parameter showing the most marked difference between the hydronephrotic and the contralateral kidney. For sodium and chloride the difference between the two sides in the reabsorbed amount in per cent of the filtered load was correlated probably significantly to the degree of renal pelvic dilatation.

Animals↗
PubMed1976

Renal function in experimental chronic hydronephrosis. III. Glomerular and tubular functions in relation to renal pelvic volume.

Studies of renal function comprising determination of exogenous creatinine clearance, urinary osmolality and TmG were performed on 23 dogs, for each kidney separately, after hydronephrosis with partial ureteric obstruction had been produced by ligation of one ureter over an indwelling catheter. A method for determining the volume of the hydronephrotic renal pelvis was developed and the degree of functional reduction was correlated to the degree of pelvic dilatation. In 11 cases the renal blood flow was determined by direct measurement. Statistically significant reductions of the glomerular and tubular functions were noted on the hydronephrotic side. TmG and the urinary osmolality showed the greatest percentual decreases and the TmG/GFR ratio the smallest. The decrease in this ratio was due to greater deterioration of tubular than of glomerular function. The renal blood flow was reduced on the hydronephrotic side in comparison with the intact side, but seemed relatively less affected than the glomerular and tubular functions. Compensation by the intact kidney resulted in masking of the deterioration on the hydronephrotic side; thus for the whole material the mean GFR and urinary osmolality for the two kidneys together remained essentially unchanged. No statistically significant correlation between the degree of functional reduction and the degree of pelvic dilatation was found. Such a correlation could therefore not be used in the individual case as an indication of the functional capacity of a kidney.

Animals↗
PubMed1975

Renal function in experimental chronic hydronephrosis. I. Backflow studies with dextran.

By ligation of the ureter, causing partial ureteral stenosis, unilateral hydronephrosis was induced in 10 dogs. Renal function studies including creatine clearance and osmolality determination were performed both before and after the ureteral ligation. The renal function analysis after induction of hydronephrosis included pyelovenous and pyelolymphatic reflux studies, with deposition of dextran in the renal pelvis at different intrapelvic pressures. Analysis with respect to sodium, potassium, chloride and dextran in the thoracic duct lymph, peripheral blood and urine from the intact kidney were performed. The results show a reduction of the renal function in hydronephrosis, little transport of dextran via the lymph and blood, and no significant increase in the lymphatic transport of the studied ions on elevation of the intrapelvic pressure.

Animals↗
PubMed1975

Renal function in experimental chronic hydronephrosis. II. Backflow studies with radionuclides.

Studies of backflow in experimental unilateral chronic hydronephrosis in dogs with a known residual renal function and renal pelvic volume were performed with radioactively labelled substances with molecular weights of ca. 600, 5 200 and 68 000 placed in the hydronephrotic renal pelvis. Three different pressure levels in the renal pelvis were used. Isotope concentrations were determined in the thoracic duct lymph, 0lood and urine from the contralateral kidney. The greater part of the test substances appeared to pass to the blood circulation, while a smaller part was found in the lymphatic ducts. The largest molecule, however, was only able to leave the renal pelvis to any appreciable extent at the highest pressure. In kidneys with a low grade of hydronephrosis and well preserved function, a relatively large amount of test substance left the renal pelvis (ca. 10-15%). In more advanced grades of hydronephrosis with greater impairment of renal function, the backflow was considerably less.

Animals↗
PubMedDate not supplied

On the frequency of chromosome exchanges in a control population measured by chromosome painting.

Chromosome painting has been shown to be a valid and rapid method for quantifying structural chromosome rearrangements in human lymphocytes. The method is particularly useful for detecting stable aberrations which are difficult and expensive to quantify with classical methods. The inherent stability of translocations has enabled them to be used as a biodosimeter for chronic and temporally displaced exposure to radiation. Translocations may also be useful for quantifying chronic exposure to other environmental agents which may result in an accumulation of cytogenetic damage with age. Most exposures are chronic and occur at low rates, and conventional cytogenetic methods such as dicentric analysis are not expected to be informative. To understand the extent to which age and lifestyle factors impact the frequency of stable aberrations, we have performed chromosome painting on metaphase-arrested lymphocytes cultured from 47 healthy adults ranging in age from 19 to 77 years, and from umbilical cord blood obtained from eight healthy full-term infants. All subjects had previously been screened to eliminate those who had received significant occupational or accidental exposure to radiation or chemicals, and none had received chemo- or radiotherapy. Due to the infrequent occurrence of stable aberrations in peripheral lymphocytes, we analyzed the equivalent of more than 1100 metaphase cells from each of these 55 people. An average of one cell in 130 (0.77%) was observed to have a translocation or a stable insertion. A significant relationship between stable aberrations and the square of the age is apparent (R2 = 0.69, Y = 0.0615 + 0.000304 age2; p < 0.00001). These results support the hypothesis that stable aberrations accumulate with time, and are likely to integrate adverse environmental exposure.

Adult↗
PubMedDate not supplied

Apolipoprotein D is associated with long-term outcome in patients with schizophrenia.

Accumulating evidence implicates deficiencies in apolipoprotein D (ApoD) function and arachidonic acid signaling in schizophrenic disorders. We addressed two hypotheses in relation to ApoD: first, polymorphisms in the ApoD gene confer susceptibility to or are markers of disease, and, second, genetic variation in the ApoD is associated with long-term clinical outcome to antipsychotic treatment. We genotyped two single-nucleotide polymorphisms in the ApoD gene in 343 chronic patients with schizophrenia spectrum disorders (ICD-10) and 346 control subjects of Danish origin. We did not find ApoD alleles, genotypes or haplotypes to be associated with disease. However, we did find that long-term clinical outcome was associated with the ApoD polymorphism rs7659 (P = 0.041) following adjustment for lifetime clinical global impression, age at first admission and gender.

Adult↗
PubMedDate not supplied

The wound healing process in surgical patients evaluated by the expanded polytetrafluoroethylene and the polyvinyl alcohol sponge: a comparison with special reference to intrapatient variability.

The aim of this study was to compare two wound healing models in surgical patients with special reference to the intrapatient variability. Two pieces of expanded polytetrafluoroethylene tubing and one perforated silicone tube containing two polyvinyl alcohol sponges were subcutaneously inserted into 28 patients and were removed after 10 (9 to 11) days. The amount of hydroxy-l-proline in two segments of the same piece of expanded polytetrafluoroethylene tubing correlated significantly with each other. Similar results were found for proline. Proline content in each polyvinyl alcohol sponge correlated weakly with each other, whereas no correlation was found between hydroxy-l-proline content in the two polyvinyl alcohol sponges from the same patient. In addition, no correlation was found between leucine in the two adjacent polyvinyl alcohol sponges or between the hydroxy-l-proline/leucine ratio in these same sponges. No concordance could be detected between the averages of hydroxy-l-proline content in the two segments of expanded polytetrafluoroethylene tubing and the hydroxy-l-proline content in the two polyvinyl alcohol sponges from the same person, although an association between the averages of proline in the two pieces of expanded polytetrafluoroethylene tubing and proline content in the two polyvinyl alcohol sponges from the same individual was observed. The measurement error was greater for the polyvinyl alcohol sponges than for the expanded polytetrafluoroethylene tubing implants during the first 10 days after wounding. The expanded polytetrafluoroethylene tubing accumulated 2.5 times more hydroxy-l-proline per length unit than the polyvinyl alcohol sponge. We concluded that the expanded polytetrafluoroethylene implant rather than the polyvinyl alcohol implant is preferred for quantitation of subcutaneous collagen deposition in surgical patients because it accumulates more new tissue and has a lower variability.

Journal Article↗
PubMedDate not supplied

Evaluating the treatment of emotionally disturbed adolescents.

The authors designed a scale, the Massachusetts Adolescent Level of Functioning Scale, for measuring the behavior of emotionally disturbed adolescents. Among the many uses of the scale are specifying a standard intervention for any given problem indicator and measuring the outcome. A pilot test demonstrated that the scale has broad applications for determining cost-effectiveness of programs and for improving service delivery.

Adolescent↗
PubMedDate not supplied

Application of Karasek's demand/control model a Canadian occupational setting including shift workers during a period of reorganization and downsizing.

PURPOSE: To apply Karasek's Job Content Model to an analysis of the relationships between job type and perceived stress and stress behaviors in a large company during a period of reorganization and downsizing. DESIGN: Cross-sectional mail-out, mail-back survey. SETTING: A large Canadian telephone/telecommunications company. SUBJECTS: Stratified random sample (stratified by job category) of 2200 out of 13,000 employees with a response rate of 48.8%. MEASURES: Responses to 25 of Karasek's core questions were utilized to define four job types: low-demand and high control = "relaxed"; high demand and high control = "active"; low demand and low control = "passive", and high demand and low control = "high strain." These job types were compared against self-reported stress levels, perceived general level of health, absenteeism, alcohol use, exercise level, and use of medications and drugs. Similar analyses were performed to assess the influence of shift work. RESULTS: Employees with "passive" or "high strain" job types reported higher levels of stress (trend test p < .0001); poorer health (trend test P = .006); and higher levels of absenteeism (trend test p < .0001). More shift workers reported themselves in poor or fair health (chi-square p = .018) and reported high levels of stress at home (chi-square p = .002) than nonshift workers. The relationships between job type and levels of stress, health and absenteeism, however, held for nonshift workers as well. CONCLUSIONS: Job types with high demand and low control were associated with increased stress, increased absenteeism, and poorer self-concept of health. The demand/control model of Karasek and Theorell was validated in this setting with respect to stress and some stress-associated attitudes and behaviors.

Adult↗