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Biomedical subjects

B Nielsen

Publications and source records attributed to B Nielsen.

At least 199 records · Page 11Linked to original sources
PubMed1990

Immunohistochemical analysis of the binding of human IgM to secretory component present in normal adult colon epithelia, but not in colon cancer and fetal colon epithelia.

We have analysed the binding of human IgM to fetal, normal adult and malignant colo-rectal tissues. Using an indirect immunoperoxidase technique on sections of frozen tissues human IgM binds to all normal adult colo-rectal epithelia (n = 15) tested. By contrast, 9 out of 25 colo-rectal adenocarcinomas were negative, and in the remaining 16 the staining reaction varied from staining of all the cancer areas to focal staining of a few areas. Human IgM did not bind to 14 samples of fetal intestinal epithelium (gestational age of 6-14 weeks). The binding of IgM was found to be mediated by secretory component (SC) as anti-SC antibody (anti-SC) showed a similar staining pattern as IgM and the IgM binding could be blocked by anti-SC. SC was also demonstrated in glandular epithelia of sections of all normal breast epithelia but only in 10 out of 15 breast adenocarcinomas. The loss of IgM binding and SC could not be correlated to the morphology of the adenocarcinomas. The observations on fetal, normal adult and malignant tissue suggest that IgM binding and SC may be gradually lost during dedifferentiation of normal cells, to malignant colo-rectal or breast epithelia.

Adenocarcinoma↗
PubMed1990

Treatment with total lymphoid irradiation, cyclosporin A and a monoclonal anti-T-cell antibody in a hamster-to-rat heart transplantation model: graft survival and morphological analysis.

Treatment with preoperative total lymphoid irradiation and post-transplant cyclosporin A has been shown to have a synergistic effect on graft survival in allo- and xenotransplantation. Specific monoclonal antibodies against T cells and T cell subpopulations could offer new ways of preventing graft rejection in xenotransplantation. Graft survival and histology were examined after total lymphoid irradiation plus cyclosporin A treatment versus cyclosporin A plus a monoclonal antibody in a concordant, heterotopic, hamster-to-rat heart transplantation model. Preoperative total lymphoid irradiation was given at a dose of 1.25 Gy, 12 times over a period of 3 weeks. Cyclosporin A at a dose of 12.5 mg/kg per day was administered perorally and OX-19, a pan T cell monoclonal antibody, was given as intraperitoneal injections at doses of 100 micrograms or 500 micrograms/kg per day from day 0 until graft rejection. While total lymphoid irradiation alone prolonged graft survival to 9.4 days, total lymphoid irradiation plus cyclosporin A extended graft survival to a mean of 22 days. Cyclosporin alone or combined with the monoclonal antibody could not increase graft survival significantly when compared to untreated animals, which rejected their grafts within 3.7 days. Vascular rejection was the characteristic morphological finding, even after some weeks of excellent graft function. In conclusion, total lymphoid irradiation and cyclosporin A had a synergistic effect on graft survival in this concordant xenotransplantation model, although recent impressive results from other groups could not be reproduced. Total lymphoid irradiation combined with cyclosporin A appears to delay a primary humoral graft rejection, while the mechanism of rejection, judged by histology, stays the same.

Analysis of Variance↗
PubMed1990

Solar heat load: heat balance during exercise in clothed subjects.

Six subjects exercised for 60 min on a cycle ergometer. Their backs were exposed to an artificial 'sun' with a spectral distribution similar to sunlight and an intensity of 724 W m-2. Each subject took part in four experiments in random order: wearing suits of polyester (insulation value = 0.5 clo), white (WP) or black (BP), or cotton (0.6 clo), white (WC) or black (BC). Measured by partitional calorimetry, the calculated heat losses and gains for the four conditions balanced within less than 10%. The differences between the short-wave radiation gains of subjects in white or black garments were small. This is due to the transparency of the white materials, which allows a larger percentage of the radiation to penetrate the clothing. The surface temperatures of the sun-exposed areas were very high, especially in the black suits. This promotes dry heat loss. Therefore the sweat loss in the black suits and the differences between the black and white clothes became relatively small. The physiological strain in steady-state exercise, as expressed by average heart rates, was 142 (WP), 154 (BP), 151 (WC), and 160 (BC) beats min-1; the sweat losses were 649 (WP), 666 (BP), 704 (WC), and 808 (BC) g. For both of these measures values for white polyester were significantly less than those for black cotton.

Adult↗
PubMed1990

Immunohistochemical study of possible changes in keratin expression during neoplastic transformation of the uterine mucosa.

The present study aimed to examine possible changes in keratin expression during neoplastic transformation of the uterine mucosa and possible differences in keratin expression between endocervical and endometrial adenocarcinomas. Routinely processed specimens with normal morphology or neoplastic changes were stained immunohistochemically using 5 commercial antibodies to keratin-filaments of molecular weight 39-58 kD: CAM 5.2, RCK 102, MCA 144, PKE and PRE. We generally found a change in keratin expression during the neoplastic transformation, consisting of pronounced heterogeneity compared with normal epithelia. In distinguishing koilocytic atypia from CIN, RCK 102 (52.5, 58 Kd) may prove helpful as it stains neoplastic cells strongly and shows no reaction in koilocytic. Staining with the antibody CAM 5.2 (reactive with 39, 43, 50 kD filaments) may aid in distinguishing between cervical and endometrial adenocarcinomas. The former is stained uniformly; the latter shows a more variable staining.

Adenocarcinoma↗
PubMed1990

Trypanosoma brucei: two-dimensional gel analysis of the major glycosomal proteins during the life cycle.

Kinetoplastid organisms possess a unique organelle, the glycosome, which compartmentalizes the Embden-Meyerhof segment of glycolysis and several other metabolic pathways. In Trypanosoma brucei many of the enzyme activities localized to the glycosome are stage regulated. Two-dimensional gel analysis was used to examine the characteristics, expression, and biosynthesis of the major glycosomal proteins. Two-dimensional gel maps of glycosomes from slender bloodforms and late intermediate-stumpy bloodforms (the precursors of procyclic forms) were indistinguishable, while those of procyclic form glycosomes showed extensive differences. Glycosomal phosphoenolpyruvate carboxykinase and malate dehydrogenase were identified to have subunit molecular weights of 60 and 34 kDa, respectively. We detected two hitherto undescribed glycosomal proteins, one of which is found only in bloodforms. All of the major proteins, except glucose phosphate isomerase, were highly basic. Stage regulation of glycosomal enzyme activities correlated with stage regulation of specific protein biosynthesis.

Animals↗
PubMed1990

Effects of recombinant human erythropoietin on the haemopoietic bone marrow monitored by magnetic resonance spectroscopy in patients with end-stage renal disease.

Volume selective magnetic resonance (MR) proton spectroscopy was used to investigate changes in the haemopoietic bone marrow in patients with end-stage renal disease undergoing treatment with recombinant human erythropoietin (rHuEPO). Significant changes could be detected in the spectra 14 days after the beginning of treatment, before any response was seen in the haemoglobin concentration of peripheral blood. The spectral changes indicate an alteration in cellular composition of haemopoietic bone marrow with an increase in the amount of haemopoietic active tissue. One patient showed a major change in the spectrum four days after treatment began, indicating that MR spectroscopy may detect early changes in the cellular composition of the bone marrow. This noninvasive method may be useful in evaluating treatment effects of recombinant human haemopoietic growth factors in the bone marrow, as well as investigating bone marrow response from different modes of rHuEPO administration.

Adult↗
PubMed1990

Entrapment of a tined pacemaker electrode in the tricuspid valve. A case report.

A tined pacemaker electrode was entrapped in the tricuspid valve apparatus. Nonresponding, sustained ventricular tachycardia, and cardiac arrest necessitated forcible removal of the electrode causing partial avulsion of the tricuspid valve. Hemodynamically insignificant tricuspid regurgitation developed subsequently.

Electrodes, Implanted↗
PubMed1990

Attempted suicide in Denmark. IV. A five-year follow-up.

From October 1, 1980 to April 20, 1981, 207 patients were admitted to the Department of Psychiatry, Odense University Hospital, after attempting suicide. Information on physical, mental and social conditions was collected. The patients were then followed for 5 years, to register subsequent suicidal behaviour and to try to identify relevant factors for evaluation of future suicide risk. During the follow-up period 11.6% of the attempters committed suicide, the majority within the first year after the index attempt. Seventy-five percent of the suicides were committed less than 6 months after the last contact with the psychiatric ward. Predictors for future suicide were chronic somatic disease, depression, abuse of medicine, and chronic alcohol abuse. The authors emphasize the need for a thorough medical evaluation of patients attempting suicide, to be able to identify and eventually treat these conditions.

Adult↗
PubMed1990

Human-human hybridoma producing monoclonal antibodies against colorectal cancer-associated antigens.

Lymphocytes from lymph nodes draining the tumor region in patients with colorectal cancer were fused with two different human B-lymphoblastoid cell lines, LICR-LON-HMy-2 (HMy-2) and WI-L2-729-HF2 (729-HF2), to generate hybridomas synthesizing antibodies reacting with tumor-associated antigens. In this way 220 hybridomas were obtained which produce antibody reacting with colon cancer cells. All established clones produced IgM. Four human monoclonal antibodies have been further analyzed. The cell lines producing these antibodies are all hybrids based on DNA analysis. Three of the antibodies (G4146, B9165 and D4213) showed binding to differentiation antigens by immunocytochemical analysis on different cancer cell lines and normal human leucocytes and by immunohistochemical analysis on sections of frozen malignant and normal tissues, while the fourth (F11348) showed a reaction with all cells and tissues tested. Western blots of tumor extracts showed binding of G4146 to two components from colon cancer cells with Mr of 59 K and 61 K, while B9165 bound to a 43 K component and F11348 to several components with Mr from 30 to 200K. D4213 showed no binding in this analysis. The results obtained demonstrate the successful application of hybridoma technology to produce human monoclonals with reactivity to differentiation antigens.

Antibodies, Monoclonal↗
PubMed1990

Muscle blood flow and muscle metabolism during exercise and heat stress.

The effect of heat stress on blood flow and metabolism in an exercising leg was studied in seven subjects walking uphill (12-17%) at 5 km/h on a treadmill for 90 min or until exhaustion. The first 30 min of exercise were performed in a cool environment (18-21 degrees C); then subjects moved to an adjacent room at 40 degrees C and continued to exercise at the same speed and inclination for a further 60 min or to exhaustion, whichever occurred first. The rate of O2 consumption, 2.6 l/min (1.8-3.3) (average from cool and hot conditions), corresponded to 55-77% of their individual maximums. In the cool environment a steady state was reached at 30 min. When the subjects were shifted to the hot room, the core temperature and heart rate started to rise and reached values greater than 39 degrees C and near-maximal values, respectively, at the termination of the exercise. The leg blood flow (thermodilution method), femoral arteriovenous O2 difference, and consequently leg O2 consumption were unchanged in the hot compared with the cool condition. There was no increase in release of lactate and no reduction in glucose and free net fatty acid uptake in the exercising leg in the heat. Furthermore, the rate of glycogen utilization in the gastrocnemius muscle was not elevated in the hot environment. There was a tendency for cardiac output to increase in the heat (mean 15.2 to 18.4 l/min), which may have contributed to the increase in skin circulation, together with a possible further reduction in flow to other vascular beds, because muscle blood flow was not reduced.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

Hope for successful xenografting by immunosuppression with monoclonal antibody against CD4, total lymphoid irradiation and cyclosporine. Six months' survival of hamster heart transplanted into rat.

Hamster hearts were transplanted to rats, and the effects of combinations of total lymphoid irradiation (TLI), cyclophosphamide, cyclosporine A (CyA) and monoclonal antibodies (MAB) were investigated. Controls not immunosuppressed rejected their xenograft in 3 to 5 days, while combination immunosuppression including MABs against CD4 or IL-2-receptors extended graft survival significantly. In one case, the graft was still functioning 180 days after transplantation, which is the longest survival seen in this model. The use of specific MABs may open a new era for both xeno- and allo-transplantation.

Animals↗
PubMed1990

On the need for erythropoietin treatment in dialysis patients. A Copenhagen City Dialysis Unit study.

We evaluated the need for erythropoietin (EPO) treatment in 134 end-stage renal disease patients assuming a level of hemoglobin below 6 mmol/l (9.6 g/dl) as indication for treatment. 91 patients (68%) fulfilled this criterion. Absolute contraindications in 2 patients were previous thrombotic encephalopathy and refusal of treatment. Relative contraindications due to cardiac disease were found in 3 patients. In 15 patients additional treatment was required because of hypertension (5) or deficiency states (10). The implications of elevated serum PTH and aluminum overload are discussed.

Anemia↗
PubMed1990

Magnetic resonance imaging of the bone marrow following treatment with recombinant human erythropoietin in patients with end-stage renal disease.

We used magnetic resonance imaging (MRI) to study vertebral bone marrow in hemodialysis patients during treatment with recombinant human erythropoietin (rHuEPO). We found changes in T1 relaxation times and image contrast within 14 days after starting treatment, before any response was seen in the hemoglobin concentration in peripheral blood. The increase in T1 relaxation times, together with earlier reported changes observed with localized magnetic resonance spectroscopy, indicate an alteration in cellular composition of the hemopoietic bone marrow with an increase in the amount of hemopoietic active tissue. MRI may be a useful, non-invasive way of evaluating bone marrow response to different modes of rHuEPO administration and dosage.

Anemia↗