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Biomedical subjects

F Kristensen

Publications and source records attributed to F Kristensen.

At least 19 recordsLinked to original sources
PubMed2005

Association between allergic rhinitis and hospital resource use among asthmatic children in Norway.

BACKGROUND: Preliminary evidence suggests that inadequately controlled allergic rhinitis in asthmatic patients can contribute towards increased asthma exacerbations and poorer symptom control, which may increase medical resource use. The objective of this study was therefore to assess the effect of concomitant allergic rhinitis on asthma-related hospital resource utilization among children below 15 years of age with asthma in Norway. METHODS: A population-based retrospective cohort study of children (aged 0-14 years) with asthma was conducted using data from a patient-specific public national database of hospital admissions during a 2-year period, 1998-1999. Multivariate linear regression, adjusting for risk factors including age, gender, year of admission, urban/rural residence and severity of asthma episode, estimated the association between allergic rhinitis and total hospital days. A multivariate Cox proportional-hazards model estimated relative hazard of readmission according to concomitant allergic rhinitis status. RESULTS: Among 2961 asthmatic children under 15 years of age with at least one asthma-related hospital admission over a 2-year period, 795 (26.8%) had a recorded history of allergic rhinitis. Asthmatic children with allergic rhinitis had a 1.72-times greater hazard of asthma-related readmissions than asthmatic children without allergic rhinitis. Multivariate analysis revealed that history of concomitant allergic rhinitis was a significant predictor of increased number of hospital days per year (least-squares mean difference 0.23 days, P < 0.05). CONCLUSIONS: Concomitant allergic rhinitis in asthmatic children was associated with increased likelihood of asthma-related hospital readmissions and greater total hospital days.

Adolescent↗
PubMed2002

A retrospective study of hyposensitization in canine atopy based on a polyclonal ELISA test.

Compliance with the treatment protocol and the most significant reasons encountered in general practice for the discontinuation of treatment in hyposensitized dogs are examined. The data are based on (1) a review of order forms for the hyposenzitization mixture and information sheets for an ELISA test and (2) telephone interviews with dog owners. Most of the owners (81%) gave their dogs allergen injections at home. Non-compliance was defined as discontinuation of treatment in the induction period; 33.9% of the owners became non-compliant. A large proportion of non-compliant owners (51.2%) claimed to be unaware of the length of the induction period. Furthermore, 70.2% of the owners were not aware that treatment would most likely need to be lifelong if it was to remain effective. Although 67.5% of the owners perceived that their dogs had beneficial effects from hyposensitization, only 36.3% of the dogs were receiving maintenance injections at the time of the telephone interview, considerably reducing the long-term benefit from treatment. Canine atopy is a chronic disease characterized by remission and relapses. Since no control group was available in this study, the beneficial outcome of treatment reported by the owners could be partly due to the natural course of the disease. Nevertheless, the results indicated that the long-term effect of hyposensitization in canine atopy will be reduced by premature discontinuation of treatment in the maintenance period. The discontinuation of treatment could be a reflection of the treatment becoming less effective, owing to the development of new hypersensitivities or to a reduction in the placebo effect that may occur in 'new' treatments. However, poor client education and follow-up seem to be important reasons for both noncompliance and discontinuation of the treatment in the maintenance period.

Allergens↗
PubMed1998

Composition of protein in urine from dogs with pyoderma.

The protein fractions in urine from proteinuric dogs with and without pyoderma were estimated. Fifteen dogs with pyoderma (five with superficial and 10 with deep pyoderma) were compared with 10 dogs with glomerulopathy and 27 dogs with diseases other than pyoderma or urinary tract problems. Agarose gel electrophoresis was used to fractionate the proteins. Three types of electrophoretogram were obtained with albuminuria, globulinuria and serum-like profiles. An albuminuria profile was found in eight of the 27 dogs with other diseases, in three of the five dogs with superficial pyoderma, in eight of the 10 dogs with deep pyoderma and in all 10 dogs with glomerulopathy. The albuminuria profile (mean [sem] albumin/globulin ratio 1.98 [0.10]) was also characterised by alpha 1b, alpha 2a and beta 2 globulin peaks in all 29 dogs with this profile, which was therefore thought to indicate that albuminuria (glomerular proteinuria) was a result of glomerular damage and inflammation because alpha 1b, alpha 2a, and beta 2 globulins are considered to be acute phase proteins. The serum-like profile (mean [sem] albumin/globulin ratio 0.72 [0.01]) was observed in 13 per cent of the proteinuric dogs examined and contained all the protein fractions normally detected by electrophoresis of serum. The profile was considered to be a variant from of the albuminuria profile, probably indicating advanced glomerular lesions and inflammation. The globulinuria profile (mean [sem] albumin/globulin ratio 0.33 [0.08]) was significantly different from the other two in that it was characterised by a low albumin peak and the presence of globulin fractions not clearly distinguishable from each other because of their confluency and absence of individual peaks. This profile could indicate severe glomerulotubular lesions and degradation of certain protein fractions. It could also be a result of increased secretion of tissue and other proteins by damaged tubules. It was concluded that glomerular damage leads to glomerular proteinuria characterised by high proportions of albumin together with alpha 1b, alpha 2a and beta 2 globulins in lower but significantly diagnostic proportions.

Albuminuria↗
PubMed1998

Development and validation of an improved enzyme-linked immunosorbent assay for the detection of thyroglobulin autoantibodies in canine serum samples.

An enzyme-linked immunosorbent assay to detect thyroglobulin autoantibodies (TGAB) in canine serum was developed and validated. The test result for each sample was derived from the optical density readings (OD) and expressed as an Ab-score(%) calculated from three in-house calibrators. The assay specifically detected TGAB as judged from lack of response in the assay after samples had been incubated with specific antigen. Intra- and interassay coefficients of variation ranged from 2.0-4.9% and 4.6-9.9%, respectively. The detection limit, an Ab-score of 5.6%, was close to the median Ab-score of 10% observed in healthy dogs (n = 132). The median Ab-score of dogs with primary hypothyroidism and lymphocytic thyroiditis (n = 11), skin diseases (n = 35), and non-thyroidal diseases (n = 63) was 340%, 12%, and 8%, respectively. The prevalence of TGAB in hypothyroid dogs with lymphocytic thyroiditis (sensitivity) was 91% (95% confidence limits: 59%-99%). In dogs with dermatological diseases without lymphocytic thyroiditis the prevalence of TGAB was 3% corresponding to a specificity of 97% (95% confidence limit: 85%-100%). In dogs with non-thyroidal diseases and healthy dogs the prevalence of TGAB was 5% and 6%, respectively. The diagnostic accuracy of serum TGAB was evaluated by subjecting the data from 11 dogs with lymphocytic thyroiditis and 35 control dogs without lymphocytic thyroiditis to receiver-operating characteristic curve analysis. The area under the receiver-operating characteristic curve (W = 0.966; 95% confidence limit 87%-100%) was significantly higher than that of a worthless test (0.5) (P < 0.0001), thereby indicating that serum TGAB measurements distinguished between dogs with and without lymphocytic thyroiditis.

Animals↗
PubMed1996

Evaluation of an immunoradiometric assay for thyrotropin in serum and plasma samples of dogs with primary hypothyroidism.

A commercially available immunoradiometric assay was used to measure the thyrotropin (TSH; thyroid-stimulating hormone) concentration in the serum and plasma of 23 dogs. The basal concentration in five dogs with histologically confirmed primary hypothyroidism (median 0.18 microg/l, range 0.16-0.72 microg/l) was slightly, but not significantly, higher than that in 13 clinically healthy dogs (median 0.09 microg/l, range 0.06-0.34 microg/l). The TSH values in 11 euthyroid dogs with various dermatological diseases (median 0.09 microg/l, range 0.05-0.53 microg/l) were significantly lower than in the hypothyroid dogs, but there was considerable overlap. The assay alone was therefore not capable of giving a firm diagnosis.

Animals↗
PubMed1996

Urinary tract infection: the role of canine transmissible venereal tumour.

The role of transmissible venereal tumours in the pathogenesis of urinary tract infection in dogs was investigated in 86 dogs. Fifty-five had transmissible venereal tumours, and the remaining 31 animals were used as controls. A thorough clinical examination of the external genitalia was carried out in each case. In the dogs with transmissible venereal tumours, the sites of attachment were recorded. Urine samples were taken by cystocentesis and the external genitalia swabbed; the samples were cultured for bacteria using standard methods. Tumours were found on the prepuce and other parts of the penis in male dogs; in bitches they were found in the vagina, vestibule or the vestibulovaginal junction. Dogs with transmissible venereal tumours were found to be at a high risk of having bacteriuria (odds ratio [OR] = 7.04). Obliteration of the urethral orifice by the tumour, possibly leading to urine retention, was thought to be the main reason for the high incidence of urinary tract infection among dogs with transmissible venereal tumours. Long-standing cases of transmissible venereal neoplasia had a higher chance of becoming bacteriuric compared with recent cases (OR = 29.60). This study indicates that transmissible venereal tumour may be a predisposing factor for the development of urinary tract infection.

Animals↗
PubMed1995

Diagnostic importance of urothelial cells of the dog and cat.

The cells lining the canine and feline urinary tract and their role in the diagnosis of urological diseases in small animals is assessed. The urothelium was found to consist of transitional epithelial cells ranging from the calyces to the urethra. Caudate cells were found lining the ureter, renal pelvis and the calyces. There was no feature that could be used to distinguish the transitional cells from different parts of the urothelium. Squamous cells were found lining the urinary tract from the trigone to the vagina in females and to the urethra in male animals. Hydropic degeneration in the form of vacuolation of the cytoplasm, granulation and total loss of cytoplasm was one of the urine-induced degenerative changes recorded in the transitional cells. The significance of the degenerative changes in the management of urological problems is discussed.

Animals↗
PubMed1993

[Prioritizing in hospital departments].

A framework for decision-making is introduced in which two out of five patients will be denied treatment. Certain resource constraints are accepted in this hypothetical example. The authors' own ranking of five patients from a department of internal medicine are presented. It was not difficult to select the highest prioritized patients. However, ranking of the remaining patients revealed considerable controversy. Emphasis is therefore laid on the reasons given for each ranking. An interesting finding is that variations in awarding priority to some cases are clearly based on disagreement about facts, not values. The article concludes by suggesting a classification of selection criteria for priority setting based on a distinction between necessary, controversial and unacceptable criteria. The article is presented in an attempt to stimulate a debate about priority setting in everyday hospital work.

Decision Making↗
PubMed1991

Enhanced granulocyte function in a case of chronic granulocytic leukemia in a dog.

Chronic granulocytic leukemia is a rare myeloproliferative disorder in dogs. The present study investigated various functions of leukemic granulocytes in a dog that presented with thrombocytopenic purpura, anaemia and a classical leukemic hemogram. All analyses were performed in parallel with a control dog. Purification of the leukemic granulocytes by density gradient centrifugation revealed three neutrophil and neutrophil precursor populations with different densities. Comparison of cell morphology and density showed that cell density increased with increasing maturity. The control dog possessed only one neutrophil population, with a density greater than 1.077. Analysis of cellular contents of the granular enzymes, elastase, myeloperoxidase and lysozyme showed that leukemic neutrophils were quantitatively markedly different from normal neutrophils with respect to enzyme activities. There were no major differences between leukemic and normal cells as regards aggregatory and migratory responses to different stimuli. The phagocytic capacity of the leukemic cells, however, was dramatically increased compared with the control, and exceeded all previously encountered responses in the assay employed. In a similar fashion, superoxide generation and secretion of elastase and lysozyme in response to zymosan and phorbol myristate acetate were substantially higher than in the control dog. Priming of cell function to a level exceeding that normally attainable in neutrophils appears to have taken place in peripheral blood of the leukemic dog. The only endogenous mediator known to prime neutrophil functions to the extent seen in the present case is the cytokine granulocyte-macrophage colony-stimulating factor (GM-CSF), which is intimately involved in regulation of myelopoiesis in mammals. On the basis of the enzymological and functional findings in the leukemic dog, we hypothesize that a lactoferrin deficiency in leukemic neutrophils leads to enhanced GM-CSF synthesis, which is ultimately the cause of the observed cellular hyperresponsiveness and contributes to the monocytosis seen in the patient.

Animals↗
PubMed1991

Impairment of neutrophil functions in a dog with an eosinophilic dermatosis.

An eosinophilic dermatosis was diagnosed in a dog with a multifocal distribution of pruritic, pustular and erosive lesions on the trunk. Ectoparasites, fungi and bacteria were not detected in the skin of the dog. At a subsequent admission to the university clinic, bacterial conjunctivitis and superficial pyoderma had developed. At a time when the dog received no medical therapy, evaluation of phagocytosis and chemotactic migration towards a variety of chemotactic factors revealed a general suppression of patient neutrophil responsiveness, as compared to a control dog. Viability of the patient's neutrophils was normal. It was proposed that deactivation of neutrophil functions occurred following exposure to suppressive factors from mast cells, or as a consequence of surface receptor down-regulation due to prolonged cell activation by as yet unknown stimulants. The observed susceptibility to infections in the dog suffering from a primary, sterile eosinophilic dermatosis may be related to impaired host defence against opportunistic microorganisms.

Animals↗
PubMed1990

Relative bioavailability of methadone hydrochloride administered in chewing gum and tablets.

Methadone administered in chewing gum in doses of 16.7-22.6 mg to seven patients in a study using an open balanced cross-over design, was compared with 20 mg of methadone given perorally as tablets. There was no significant difference in the AUC/D obtained after administration of chewing gum and tablets (p greater than 0.05). It is concluded that the chewing gum formulation should be considered for further testing with respect to suppression of abstinence syndrome in narcotic addicts.

Adult↗
PubMed1986

Interference of a C3-fragment preparation with IL 2-dependent proliferation.

A C3-fragment preparation (C3-FP) was studied for its ability to regulate human peripheral blood lymphocyte activation. It was found that very low concentrations of this low m.w. fraction, which was free of C3a, inhibited the PHA-induced lymphocyte proliferation without any cytotoxicity. Cytofluorometric analysis showed that C3-FP did not influence the transition of T cells from the G0 to the G1a phase of the cell cycle. However, the IL 2-dependent transition from the G1a to the G1b phase of the cell cycle was effectively blocked. Addition of exogenous IL 2 did not release cells arrested in the G1a phase. Furthermore, neither IL 2 production nor IL 2 receptor formation was inhibited by C3-FP, and binding of IL 2 to its receptor was unaltered. It was found that only IL 2-dependent cell lines were inhibited in their proliferation; all other tested cell lines were unaffected by C3-FP. Our findings suggest that cleaved products of C3 may inhibit IL 2-dependent lymphocyte proliferation at a stage where the IL 2 signal is required for initiation of proliferation.

Complement C3↗
PubMed1985

Age-related changes in the formation of glucocorticoid and insulin receptors during lectin-induced activation of human peripheral blood lymphocytes.

The influence of age on the number of receptors for insulin and glucocorticoids on human T cells was examined. The specific binding of 125I-insulin and 3H-dexamethasone to phytohemagglutinin-(PHA)-stimulated T cells was found to decrease with age. Populations of PHA-stimulated T cells, however, are heterogeneous with respect to cell cycle phases, and cells in different cell cycle phases have been shown to bear different numbers of receptors. Therefore, it was not clear whether the measured decrease in specific binding in cultures from aged donors was due to a decreased number of activated cells or to a decreased number of binding sites per cell. In parallel to measurements of receptors, performed at different times following stimulation (20 and 44 h), numbers of cells in the different early cell cycle phases G0, G1a and G1b were quantitated by flow cytometry. In this way the receptor number per cell in each phase of the cell cycle could be determined. Receptor numbers on resting cells and in the earliest phase of activation (G1a) were found not to be influenced by age. A decreased receptor density, however, was apparent on G1b cells from aged donors.

Adult↗
PubMed1984

Mechanisms of serotonin-induced lymphocyte proliferation inhibition.

When human peripheral blood lymphocytes were stimulated with phytohemagglutinin in the presence of serotonin, inhibition of [3H]thymidine incorporation occurred, the most marked inhibition occurring at high (10(-3)M) serotonin concentrations. This effect could not be reversed by the addition of Interleukin 2 (IL-2)-containing supernatants. Cytofluorometric analysis showed that virtually all of the cells remained in the G0 phase (unactivated) at 24 hr while some of the cells entered the G1a and G1b phases of the cell cycle by 42 hr. The cellular production of IL-2 was not affected by serotonin, as supernatants of treated cultures contained essentially the same IL-2 titers as did control cultures. Serotonin seemed to primarily affect cell activation and had little or no effect on proliferating cells. This was further confirmed by the lack of effects of serotonin on a variety of established proliferating lymphocyte, macrophage, and fibroblast cell lines. By contrast, dose-dependent inhibition of IL-2-dependent CTLL cells occurred. Serotonin was not toxic even at 10(-3) M concentrations. A marked decrease in IL-2 receptors and a change in their distribution on responder cells was seen when treated cultures were examined with the anti-Tac monoclonal antibody. At 24 hr this effect was contrastingly not seen for the OKT-8 marker, although a slight decrease in OKT-4-positive cells was seen. Serotonin thus produced an inhibition of lectin-stimulated lymphocyte proliferation via a mechanism independent of IL-2 production, and caused a decrease in the expression and distribution of IL-2 receptors on the surface of responder cells.

Adult↗
PubMed1984

Interleukin 2-independent stimulation of rabbit chondrocyte collagenase and prostaglandin E2 production by an interleukin 1-like factor.

In the present study, interleukin 1 (IL 1)-containing media from different sources, namely a murine macrophage cell line (P388D1), rabbit peritoneal macrophages, and human peripheral blood mononuclear cells, were compared for their effect on thymocyte proliferation and on collagenase and PGE2 secretion by chondrocytes. A high correlation was found between the enhancement of thymocyte proliferation and the induction of collagenase and PGE2 secretion by chondrocytes. Furthermore, a highly purified IL 1-like factor, namely mononuclear cell factor (MCF) was also active on chondrocytes. The addition of highly purified IL 2 to rabbit chondrocytes had no effect on collagenase and PGE2 secretion induced by IL 1-containing media. Our findings suggest that the factor which induced collagenase and PGE2 secretion by rabbit chondrocytes was an IL 1-like factor. Thus, collagenase secretion by chondrocytes may be used as an IL 2-insensitive assay for the detection of IL 1-like factors.

Animals↗