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Biomedical subjects

H B Rasmussen

Publications and source records attributed to H B Rasmussen.

At least 55 records · Page 3Linked to original sources
PubMed1993

Fetal antigen 2 (FA2): the aminopropeptide of the alpha 1 chain of human type I procollagen. A study on skin, tumour biology and bone metabolism.

Fetal antigen 2 (FA2) was purified from second trimester human amniotic fluid (AF) using immunospecific chromatography, gel filtration and reversed phase chromatography. Amino acid composition and sequence analyses of purified FA2 revealed identity to the amino acid sequence of the aminopropeptide of the alpha 1 chain of human type I procollagen. Gel filtration of AF as well as purified FA2 demonstrated two molecular forms of FA2, which during gel filtration were elucidated corresponding to MW of approximately 100 kDa and 30 kDa. The molecular forms were referred to as the high molecular component (FA2-HM) and low molecular component (FA2-LM), respectively. SDS-PAGE analysis (reducing and nonreducing conditions) showed a MW of 27 kDa for both FA2-HM and FA2-LM. Mass spectrometry analysis however revealed a MW of 14.343 +/- 3Da. Proteins with collagenous domains often reveal aberrant behaviour both in gel filtration and SDS-PAGE and this phenomenon may account for the apparent higher MW of FA2 observed using these techniques compared to mass spectrometry and amino acid composition/sequence analyses. A polyclonal, monospecific rabbit antibody raised against FA2 was used in immunohistochemical localization studies. Due to the obvious association of FA2 to the BM structure in adult and fetal skin, it was initially referred to as a BM associated component. However, FA2 was immunologically distinct from the well established BM components and moreover, the diffuse distribution of FA2 along the BM differed from linear localization of BM components (e.g. collagen type IV and laminin). The identification of FA2 as the aminopropeptide of the alpha 1 chain of human procollagen type I has the implication that in the immunohistochemical investigations the anti-FA2 may not distinguish between the free propeptide and procollagen type I. In the papillary dermal region of human adult skin type I collagen are arranged in loose fibrils to which the aminoterminal propeptide is still attached. Anti-FA2 may recognize epitopes in the type I procollagen present in this region, giving rise to the diffuse FA2 distribution along the BM. However, whether FA2 also appear as a free component in this region is unknown. In fetal skin where collagen is vividly layed down in the mesenchymal compartment staining with anti-FA2 revealed a diffuse mesenchymal distribution. Demonstration of FA2 within the cytoplasm of proliferating fibroblasts and diffusely in granulation tissue during wound healing suggest that FA2 was involved in the reparative processes.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗
PubMed1993

Retroviral interference with neuronotrophic signaling in human motor neuron disease?

We tested 13/32 patients with non-familial amyotrophic lateral sclerosis (ALS) positive (41%) for human spuma retrovirus (HSRV) seroreactivity. Half the non-ALS HSRV-positive neurologic patients (12/25) reported multiple fasciculations within the last two years. Sera from four HSRV-env negative ALS patients measurably competed with visna antibodies on maedi-visna antigen. The serologies for bovine leukemia virus, Borna disease virus and GM1IgM-antibodies remained negative. Both visna and foamy virus sequences share epitopes with motor nervous system signal polypeptides, suggesting a retroviral interference with motor neurono-axonal function and neuronotrophic signals.

Adolescent↗
PubMed1992

Fetal antigen 2 (FA2) in human fetal osteoblasts, cultured osteoblasts and osteogenic osteosarcoma cells.

Immunohistochemical staining techniques used on an 11-week-old fetus showed that fetal antigen 2 (FA2) was present intracellularly in endochondral and perichondral osteoblasts, and the immunoreaction was extended into the adjacent bone matrix. Osteoclasts and chondroblasts were found to be FA2 negative. A granular perinuclear intracytoplasmic FA2 immunoreaction was found in cultured osteoblasts and osteogenic osteosarcoma cells, and immunoelectron-microscopical examination revealed a granular immunoreaction product in the rough endoplasmic reticulum. These findings indicate that FA2 is synthesized by osteoblasts and osteogenic osteosarcoma cells. A reaction of immunological identity was found between FA2 purified from second trimester amniotic fluid and serum-free supernatants of cultured osteogenic osteosarcoma cells. This shows that an antigen recognized by the anti FA2 antibody is secreted by these malignant cells. Thus, FA2 may represent a marker for altered bone metabolism, and have a potential in the classification of osteogenic osteosarcoma/chondrosarcoma.

Bone and Bones↗
PubMed1992

A miniature silicon diode matrix detector for in vivo measurement of 133Xe disappearance following local tissue injection.

A variety of biological processes can be studied from the washout of compounds labelled with a gamma emitter. Conventional systems for measurement of gamma radiation can detect count rates at both the low and high energy range of the indicator in question, 133Xe. However, silicon (Si) photodiodes have the capability of measuring the lowest energies (25-40 keV) of gamma and x-ray emitters with sufficient efficiency when applied on the skin surface and close to the indicator depot. The purpose of the present study was firstly to evaluate a portable Si photodiode matrix detector system, composed of 16 photodiodes, for in vivo measurement of disappearance rate constants of 133Xe following injection into subcutaneous (SC) or skeletal muscle (SM) tissues as compared with a stationary sodium iodide single crystal detector. Secondly, from these results, to evaluate the contribution from intra-tissue indicator diffusion and indicate means of avoiding influence from local diffusion in the washout curve of 133Xe. From the recorded 133Xe distribution in the depot proper, Si photodiodes in the matrix were selected for calculation of the washout. The Si matrix detector was reliable with a constant linearity and sensitivity within the range 20-38 degrees C and calibrated to +/- 1% between diodes. The in vivo investigations comprised two SC injections on humans with four measuring periods for comparison, and four SC and five SM injections on dogs, resulting in eight and five measuring periods for comparison. Only when the results obtained from the Si photodiodes at the position just above the count rate maximum were selected, was the contribution from diffusion significant. The ability to detect geometry changes is advantageous in studies with potential motion artefacts, such as during exercise.

Americium↗
PubMed1992

Foetal antigen 2 (FA2) in relation to wound healing and fibroblast proliferation.

During wound healing of human skin the deposition of foetal antigen 2 (FA2) and basement membrane (BM) components collagen type IV and collagen VII was followed. FA2 appeared on day 8 in the cytoplasm of proliferating fibroblasts and around newly formed blood vessels. As granulation tissue was formed, FA2 was seen diffusely in the loose matrix and in proliferating fibroblasts. Re-establishment of FA2 as a broad diffuse band along the BM at the dermo-epidermal junction was seen on day 22. In contrast, type IV and VII collagen were found along the BM and in the basal cells of the newly formed epithelium and a continuous linear BM distribution of these two components were re-established by days 12 and 14, respectively. The molecular weight (Mr) analysis of FA2, isolated from human skin fibroblast culture supernatants using SDS-PAGE, revealed a Mr of 27 kDa, corresponding to that of FA2 isolated from amniotic fluid. The presence of FA2 in proliferating fibroblasts and diffusely in the newly formed matrix of granulation tissue, as well as its late appearance at the BM after this had become established, suggests that FA2 takes part in connective tissue metabolism and perhaps tissue morphogenesis.

Amniotic Fluid↗
PubMed1992

Miniature silicon diode matrix-detector for in vivo measurement of 133xenon disappearance in the canine myocardium following local tissue injection.

After local tissue depositioning of 133Xenon (133Xe) the regional washout is usually registered by a NaI(Tl) detector. The residual radioactivity of 133Xe is usually measured at its 81 keV photopeak. However, using small Silicon (Si) photodiodes it is feasible to measure only the low-energy activity in the X-ray energy range. In the myocardium of open chest dogs 133Xe washout measurements by a matrix of Si diodes composed in a 4 x 4 array and a conventional NaI(Tl) detector were carried out simultaneously. Fourteen separate pairs of measurements were performed in 3 dogs. When the Si-diodes in the matrix were selected individually in accordance to the position with reference to the diode with maximum count rate or pooled, comparisons could be made between the corresponding washout rate constants measured by the reference detector. In the correlation between the rate constants the intercepts with the y axis were not significantly different from zero allowing the correlation lines to be fitted through (0.0). The slope of the correlation line was close to unity. The registration of the low-X-ray energy of 133Xe by the Si-detectors is an alternative to the conventional high energy activity recording appearing from the gamma-energy of the photopeak. The detector matrix concept allows elimination of motion artefacts and indicator distribution in the myocardial tissue. Due to the uniformity and low cost of Si-diodes the perspective may be the introduction as a disposable transducer useful during cardiac surgery for example.

Animals↗
PubMed1992

Search for a retrovirus in multiple sclerosis by enzymatic amplification of DNA from brain capillaries, brain tissue and mononuclear cells from peripheral blood.

Attempts were made to trace a possible retrovirus in multiple sclerosis (MS) by means of polymerase chain reaction. The primers derived from conserved sequences in the genome of human T cell leukemia/lymphoma virus type I (HTLV-I) and the amplifications were carried out at varying stringency conditions (i.a. annealing at low stringency to enhance the cross-reactivity of the primers). Included in the study were samples of DNA from brain capillaries (five MS patients), brain tissue (three MS patients) and peripheral blood mononuclear cells (three MS patients). Using an HTLV-I derived probe at relaxed conditions of stringency, hybridization signals were not recorded with amplified material from any of these samples. Aspects of infections with neurotropic retroviruses that could be relevant to the search for a retrovirus in MS are reviewed.

Adult↗
PubMed1992

Seroreactivity to human T cell leukemia/lymphoma virus type 1 and related retroviruses in multiple sclerosis patients from Denmark and the Faroes.

A total of 40 multiple sclerosis (MS) patients from Denmark and 10 from the Faroes were examined for antibodies with affinity to human T cell leukemia/lymphoma virus type 1 (HTLV-I) and human immunodeficiency virus type 1 and 2 (HIV-1 and HIV-2). Using ELISA, MS patients and a group of healthy controls did not differ significantly in their reactivities to HTLV-I. However, elevated reactivities were recorded with 5 MS sera, whereas only 2 of the sera from the controls produced highly values. Ten patients with other neurological diseases all seemed to exhibit low reactivity in HTLV-I ELISA. The reactivities of 2 MS sera decreased considerably by absorption with an HTLV-I lysate. In immunofluorescence assay, two other MS sera reacted with HTLV-I transformed cell lines as well as with non-infected cells. Examined by Western blotting (WB), a single MS serum produced a distinct HTLV-I p19 band. With ELISA for detection of HIV-1 and HIV-2 antibodies, 2 MS sera exhibited borderline reactions. Further examination of these two sera by WB revealed weak reactivities against p24 and p53 of HIV-1. One the whole, the present observations do not suggest that a putative MS retrovirus would be closely related with HTLV-I, HIV-1 or HIV-2.

Adult↗
PubMed1992

Foetal antigen 2 (FA2) in the stromal reaction induced by breast carcinoma.

An indirect immunoperoxidase technique was used to examine the distribution of foetal antigen 2 (FA2), a recently described basement membrane (BM)-associated antigen, in invasive breast carcinoma (n = 34), fibroadenoma (n = 5) and normal breast tissue (n = 5), and to compare its distribution with that of laminin and collagen type IV. In normal breast tissue, FA2 was detected in the intralobular stroma as a broad band around acini and ducts, but was not present in the interlobular stroma. In areas of carcinoma in situ, FA2 was present diffusely around and in close contact with the glandular elements, the staining being more intense than that found around normal glandular structures. Two distinct patterns of FA2 distribution were found in adenocarcinomas of the breast. In the fibroblast reaction type, fibroblast staining dominated, whilst in the stromal reaction type, intense and extensive staining of the surrounding stroma dominated. Significant correlation was found between the degree of fibroblast activity and the degree of anaplasia (p = 0.005). FA2 extracted from breast carcinoma tissue was shown to be immunologically identical to FA2 fractions extracted from second trimester amniotic fluid (AF). The Mr of FA2 isolated from AF was estimated to be 26 kD, whereas the Mr of FA2 extracted from breast carcinoma tissue was slightly higher. The apparent Mr under reducing conditions were higher and three bands ranging from 26 to 29 kD were seen. FA2 was found to be immunologically distinct from collagen types I, III and IV, laminin, fibronectin and fibrinogen. The increased production and widespread distribution of FA2 in breast carcinomas suggest that FA2 is involved in the stromal changes which occur in response to tumour growth and/or invasion.

Adenocarcinoma↗
PubMed1992

Fetal antigen 2: an amniotic protein identified as the aminopropeptide of the alpha 1 chain of human procollagen type I.

Fetal antigen (FA2) was purified from second trimester human amniotic fluid by immunospecific chromatography, gel filtration and reversed-phase chromatography. Gel filtration revealed two molecular forms of FA2 eluting at volumes corresponding to an M(r) of approximately 100 kDa and 30 kDa. SDS-PAGE analysis gave an M(r) = 27 kDa under reducing and non-reducing conditions for both forms, whereas the exact M(r) determined by mass spectrometry was 14,343 +/- 3 Da. FA2 was N-terminally blocked and after tryptic digestion the amino acid composition and sequences of the peptides showed identity with the aminopropeptide of the alpha 1 chain of human procollagen type I as determined by nucleotide sequences. After oxidative procedures normally employed for radio-iodination (iodogen and chloramine-T), FA2 lost its immunoreactivity. An antigen which cross-reacted with polyclonal rabbit anti-human FA2 was demonstrated in fetal calf serum. Gel filtration with analysis of fractions by inhibition ELISA showed that the bovine homologue was present in the same molecular forms as those in human amniotic fluid, and immunohistochemical analysis with anti-human FA2 showed that its distribution in bovine skin was identical to that of FA2 in human skin. FA2 is a circulating form of the aminopropeptide of the alpha 1 chain of procollagen type I, and this is the first description of its isolation and structural characterization in humans.

Amino Acid Sequence↗
PubMed1992

Tissue localization of conglutinin, a bovine C-type lectin.

The distribution of bovine conglutinin (BK) in sections of frozen bovine tissues was studied by the indirect immunoperoxidase technique using a monospecific rabbit anti-BK antibody. BK was found in the cytoplasma of all hepatocytes, indicating that the liver is a major site of synthesis of BK. In the germinal centres of the spleen, tonsils and lymph nodes the anti-BK staining was restricted to a population of cells with a distribution and morphology characteristic of follicular dendritic cells. Macrophages in lung and thymus, and glia cells in cerebrum, revealed a granular staining reaction within the cytoplasma. Endothelial cells of blood vessels reacted with anti-BK. The intensity of this reaction varied greatly between the organs, the most pronounced reaction being seen in the glomeruli of the kidney, and in the capillary sinusoides of the cortex of the adrenal gland. The high endothelial venules of lymph nodes and tonsils were also stained. These findings suggest that BK, which until now has been described only as a circulating molecule, may exhibit a biological function within the BK-positive tissues.

Adrenal Cortex↗
PubMed1991

Physical bone changes in carragheenin-induced arthritis evaluated by quantitative computed tomography.

Repeated non-invasive measurements were performed in dogs of trabecular bone density (TBD), low density bone area (LDBA), and high density bone area (HDBA) in chronic arthritis using quantitative computed tomography (QCT). Unilateral chronic arthritis of the knee had been induced by weekly instillation of 2 ml carragheenin into the right knee joint for 12 weeks with the left knee serving as a control. CT scanning of the distal femoral condyles was performed in 12 mature dogs with chronic arthritis. Another 6 dogs underwent a longitudinal CT study starting immediately prior to induction of arthritis. During induction of arthritis TBD decreased (P less than 0.01), LDBA increased (P less than 0.05) and HDBA decreased (P less than 0.01) in the arthritic bone. Opposite changes were found on the control side, i.e. TBD increased (P less than 0.01), LDBA decreased (P less than 0.01) and HDBA increased (P less than 0.01). The chronic arthropathic bone showed 20% lower TBD (P less than 0.0001), greater LDBA (P less than 0.0001) and lower HDBA (P less than 0.0001) as compared with the control bone. Reproducibility tests of TBD showed a coefficient of variation of 0.8%. Indentation tests and histomorphometric analyses confirmed the bone density changes as measured by CT.

Animals↗
PubMed1991

Immunohistochemical studies on the localization of fetal antigen 2 (FA2), laminin, and collagen type 4 in basal cell carcinoma.

The localization of fetal antigen 2 (FA2), a recently described basement membrane (BM) associated antigen, was studied by immunohistochemical techniques in 21 basal cell carcinomas (BCC). In both superficial and infiltrating BCC, FA2 was located in a broad diffuse band around the tumor elements and in close contact with the BM. Compared to normal skin, a more extensive distribution of FA2 was seen in BCC. In the infiltrating BCC, FA2 staining was also present in the interstitial stroma between the tumor islands. FA2 was absent in areas with inflammatory cell infiltrates and elastoid degeneration. Epithelial and tumor cells were FA2 negative. The distribution of FA2 was clearly different from that of laminin and collagen type 4. Collagen type 4 and laminin were present as a continuous linear band corresponding to the BM surrounding the tumors. The close contact to the BM and the increased content of FA2 in the reactive stroma around BCC suggest that FA2 is involved in the matrix and/or BM changes taking place during tumor growth and invasion.

Antigens↗
PubMed1991

Fetal antigen 2 in primary and secondary brain tumors.

Immunohistochemical deposition and distribution of fetal antigen 2 (FA2) was examined in normal brain tissue and in primary and metastatic tumors of the brain. In normal brain tissue FA2 was exclusively found linearly around the vessels, along pia and in arachnoidea. A similar localization was seen in primary brain tumors except in gliosarcoma where FA2 was distributed diffusely in the sarcoma region and was absent in the glioma region. In metastatic carcinoma with tumor stroma a diffuse staining reaction was seen in the stroma and with a basement membrane (BM) like staining at the tumor cell/stroma interface. Intracytoplasmic FA2 staining of the tumor cells was seen in areas without tumor stroma. In metastatic melanoma a BM like FA2 staining was seen around and between individual tumor cells. The staining patterns seen in the metastatic tumors were in accordance with that of the corresponding primary tumors.

Biomarkers, Tumor↗
PubMed1990

Antibody reactivity against animal retroviruses in multiple sclerosis.

A total of 27 MS patients and 82 controls were studied for presence of antibodies reacting with maedi-visna virus and bovine leukemia virus by means of 2 ELISA techniques. Furthermore, the differentiated antibody response against BLV antigens was evaluated by immunoblotting. People with elevated activities against MVV were detected in the MS group as well as controls. Elevated antibody activity against BLV as determined by biotinylated protein A and peroxidase-labelled streptavidin tended to occur more frequently in MS patients than in controls. No such difference was found, however, when peroxidase-conjugated antibodies against human kappa chain were used for detection of antibodies reacting with BLV. Immunoblotting revealed no difference between the MS and the control group when anti-kappa antibodies were used to detect antibody binding to BLV antigens. The protein A method revealed significantly decreased antibody activity against a BLV antigen with molecular weight of about 29 kD in MS compared with controls, whereas a significant rise in number of MS patients responding to a component of about 53 kD was observed. The differences between the 2 detection systems could be due to unspecific reactions. The present data indicate that MS patients exhibit an inhomogeneous and, in some cases elevated, antibody activity against BLV.

Adult↗
PubMed1989

Localization of foetal antigen 2 (FA-2) in foetal and adult human skin.

Foetal antigen 2 (FA-2) is a connective-tissue-associated antigen isolated from second trimester human amniotic fluid. FA-2 has an alpha-electrophoretic mobility and is a single-chain molecule with a molecular weight of 26 kDa as determined by polyacrylamide gel electrophoresis (PAGE). Using indirect immunofluorescence and the immunoperoxidase technique, FA-2 was found to be in the lamina densa/sublamina densa region of the basement membrane zone (BMZ) in adult as well as in foetal skin. FA-2 was found throughout the dermis in foetal skin, whereas in adult skin it was found to be associated with the BMZ and around the blood vessels, hair follicles and eccrine glands. Intracellular FA-2 antigen was demonstrated in proliferating fibroblasts by the indirect immunoperoxidase technique and immunoelectron microscopy of the fibroblasts revealed staining of the antigen in the cisternae of the rough endoplasmatic reticulum at the trans-side of the Golgi complex as well as in vesicles close to the plasma membranes. FA-2, a hitherto undescribed antigen associated with human BMZ, is probably being synthesized by proliferating fibroblasts.

Adult↗
PubMed1989

Penicillamine-induced bullous pemphigoid with pemphigus-like antibodies.

A rheumatoid arthritis case is described who developed bullous skin eruption with mucosal involvement after 3 years of treatment with penicillamine. Histologically, changes compatible with bullous pemphigoid were found. Direct immunofluorescence showed linear, as well as intercellular, deposits of IgG. By indirect immunofluorescence IgG antibodies reacting with the basal membrane zone, as well as the intercellular substance, were detected in the serum. We believe that the patient had bullous pemphigoid with pemphigus-like antibodies induced by penicillamine.

Aged↗