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Biomedical subjects

P Andersen

Publications and source records attributed to P Andersen.

At least 271 records · Page 15Linked to original sources
PubMed1982

Persistence of transforming and nontransforming Epstein-Barr virus in high passages of P3HR-1 cell lines.

At least three laboratories have reported that the P3HR-1 line, which had originally produced transforming Epstein-Barr virus (EBV), now produces only the nontransforming variant. Studies to determine whether these findings were universal or a consequence of specific cell lines or culture conditions were undertaken in P3HR-1 cultures of identical HLA types from five sources. All of the EBV preparations derived from cell lines cultured at 32, 34, and 35 degrees C transformed cord blood lymphocytes, whereas virus propagated at 37 degrees C did not usually transform. Furthermore, indirect immunofluorescence revealed that a monoclonal antibody directed against transforming EBV membrane glycoprotein bound to 10-12% of the P3HR-1 cells that had been continuously propagated at 34 degrees C, but the antibody did not bind to the same cells cultured at 37 degrees C. Although virus expression was completely repressed in transformed cord blood cells, transforming virus could be rescued by superinfection with nontransforming P3HR-1 EBV. Cells transformed with P3HR-1 virus induced poorly differentiated lymphomas in athymic nude mice after seven or eight passages. Whether all P3HR-1 cells have the potential to produce detectable quantities of transforming virus remains to be determined.

Animals↗
PubMed1982

An indirect immunofluorescence study of antibodies to Aspergillus funigatus in sera from children and adults without aspergillosis.

An indirect immunofluorescence (IF) method for detection of antibodies of Aspergillus fumigatus was developed: it used cryosections of formaldehyde-treated mycelium as antigen. Mycelial age was found to be of importance for titer determination, and growth in Czapek-Dox broth for 48 h at 37 degrees C was considered optimal. Fluorescein-conjugated rabbit antisera to human immunoglobulins reacted by direct IF with A. fumigatus but this staining could be abolished by absorption of conjugates with homogenized mycelium of A. fumigatus. Chessboard titrations revealed plateau end-points of conjugates in the range 0 . 05-0 . 2 antibody units ml -1, which is the same range as found in other systems. Sera from 54 adults and 69 children not suspected of having fungal disease were investigated for antibodies to A. fumigatus. IgG antibodies were present at birth and the prevalence and titers fell during the first half year. Through childhood the prevalence and titers of IgG and IgM as well as IgA antibodies increased towards adult levels. In adults IgG antibodies in titers of 40 to 5120 were present in all 54 subjects tested, IgM antibodies in titers 10 to 160 occurred in 91% and IgA antibodies in titers of 10 to 80 in 78%. These findings may be explained by continuous exposure through childhood and adult life to antigens of A. fumigatus or to cross-reacting antigens.

Aging↗
PubMed1982

Serum antibodies and immunoglobulins in smokers and nonsmokers.

Antibodies to antigens in humidifier water were detected by double immunodiffusion in 30 of 63 (47.6%) persons who were exposed to aerosols from a water humidification unit in a cigar plant, whereas no antibodies could be detected in 49 unexposed blood donors (P less than 0.001). The presence of antibodies could not be related to fever or pulmonary symptoms (cough, expectoration, dyspnoe). Antibodies were found in 14 (93.3%) of 15 nonsmokers and in only 13 (31.7%) of 41 smokers (P less than 0.001), and the titres were highest in nonsmokers. Serum IgG and IgA levels were higher in nonsmokers than in smokers, and the variances within the groups were significantly different (F less than 0.05 and F less than 0.05, respectively). The mean serum IgM values were not significantly different in the two groups. Antibodies to Candida albicans and Escherichia coli 04 and 075 were detected with equal prevalences and titres in smokers and nonsmokers. These findings suggest that tobacco smoking may suppress the humoral immune response to inhaled antigens but not to antigens which are supposed to be absorbed through membranes other than those of the bronchopulmonary system. They may partly explain the reported increased incidence of allergic alveolitis in nonsmokers.

Adolescent↗
PubMed1982

Antibodies to pigeon antigens in pigeon breeders. Detection of antibodies by an enzyme-linked immunosorbent assay.

Antibodies to whole pigeon serum (PS) and pigeon dropping extract (PDE) were investigated in pigeon breeders and controls by an enzyme-linked immunosorbent assay (ELISA). The optimal antigen concentration was in the range of 3-30 microgram protein/ml for both PS and PDE. PDE antibody titres greater than or equal to 10240 were found in three (75%) of four patients with pigeon breeders' disease (PBD) and in 19 (13.6%) of 140 other pigeon breeders (P = 0.011). PS antibody titres greater than or equal to 10240 occurred in all four (100%) PBD patients and in only seven (5.0%) of 140 other breeders (P = 0.0002). In 85 blood donors antibodies in low titres against PS and PDE occurred in 4.7% and 7.1%, respectively. By immunodiffusion three or more precipitin lines were found more often in PBD patients than in other breeders (P = 0.0006), and the highest ELISA antibody titres occurred in patients with precipitating antibodies. No correlation between P blood group phenotypes or anti-P1 antibodies and respiratory symptoms or antibodies to pigeon antigens could be demonstrated.

Adolescent↗
PubMed1981

Mechanisms of norepinephrine actions on hippocampal pyramidal cells in vitro.

Responses of pyramidal cells to topical application of norepinephrine (NE) were studied by intracellular recording in hippocampal slices in vitro. Norepinephrine hyperpolarized CA1 cells. Simultaneously, there was a decreased response to constant hyperpolarizing and depolarizing current pulses. The number of spikes evoked by constant depolarizing pulses was reduced. Spontaneous activity, when present, was reduced or abolished. The response to depolarizing current pulses was reduced more than the response to hyperpolarizing current pulses. The reduction of the depolarizing response was minimal for the first 6-8 msec of the pulse, whereafter it increased. The effects persisted after blocking synaptic transmission with low calcium-high magnesium concentrations in the incubation fluid. We conclude that the hyperpolarization is most likely due to a conductance increase. The mechanism behind the reduced response to depolarizing current pulses is discussed.

Animals↗
PubMed1981

Hyperlipoproteinaemia and reduced fibrinolytic activity in healthy coronary high-risk men.

One hundred and four consecutive men from the non-symptomatic hyperlipoproteinaemic group of the Oslo Study were examined with regard to their fibrinolytic response to venous occlusion of the arm. Sixty-eight per cent showed reduced fibrinolytic activity as compared to 24% of 21 age-matched healthy coronary low-risk men. In the hyperlipoproteinaemic group, 55 individuals had been on a moderate lipid-lowering diet for about 3 years, whereas the other 49 had not (controls). The diet group showed a market tendency towards normalization of their lipoprotein patterns, but this was not significantly associated with normalization of the fibrinolytic activity. Out of 20 men with type IV hyperlipoproteinaemia, 95% showed reduced fibrinolytic activity. The association between hypertriglyceridaemia (type IV hyperlipoproteinaemia) and reduced fibrinolytic activity might possibly be explained by a reduced lipoprotein lipase activity in these individuals.

Adult↗
PubMed1981

Decreased expression of HLA-DR antigens on peripheral blood B lymphocytes during glucocorticoid treatment.

In 18 patients the expression of HLA-A, B, C and -DR antigens on peripheral blood T and B lymphocytes (PBTL and PBBL) was assessed using the lymphocytotoxic microtechnique before and during glucocorticoid administration. During steroid treatment we found a significant reduction in the reactivity of PBBL to allogeneic specific anti HLA-DR antisera as well as a xenogeneic multispecific anti HLA-DR antiserum, corresponding to approx. 1-2 dilution steps. In contrast, the reactivity of both PBBL and PBTL to allogeneic anti HLA-A, B, C antisera and anti beta 2-microglobulin was unaffected during the treatment. Membrane marker studies of the isolated PBBL and PBTL showed no differences in the relative distribution of mononuclear cell subpopulations before and during treatment, which seems to exclude extravascular redistribution of particular HLA-DR positive lymphocyte or monocyte subsets during steroid administration as an explanation for the finding. Incubation of isolated normal PBBL with dexamethasone under various conditions did not affect the reactivity of these cells to anti HLA-DR antisera. Furthermore, preliminary experiments gave no indication of decreased rate of HLA-DR antigen synthesis in the presence of dexamethasone in vitro. Thus, we conclude that glucocorticoid administration in vivo decreases the expression of HLA-DR antigens on PBBL, possibly in an indirect way, the mechanism of which is still unknown.

Antigen-Antibody Reactions↗
PubMed1981

Synaptic triggering of epileptiform discharges in Ca2 pyramidal cells in vitro.

Intra- and extracellular recordings were made in the transverse hippocampal slice in vitro to study the requirements for the triggering of epileptiform discharges of CA1 cells. Spontaneous and induced epileptiform discharges were produced by adding small amounts of sodium benzyl penicillin. Recorded intracellularly, the epileptiform activity consisted of a burst of action potentials superimposed on a depolarizing wave. Extracellular recordings demonstrated a marked synchronization. The epileptiform activity of the CA1 cells appeared without changes in the passive membrane properties or in the spike generating mechanism. Spontaneous epileptiform discharges of the CA2 cells depended upon a synaptic activation from the CA3 region. Stimulation of afferent fibres evoked an early and a late burst response in the CA2 cells. The long latency burst was caused by a re-excitation from the CA3 region. The early burst response seems to be an intrinsic property of the CA1 cells and may be induced by synaptic activation of either apical or basal dendrites. The findings suggest that synaptic depolarization is necessary for the generation of epileptiform discharges of the CA1 cells.

Animals↗
PubMed1981

Monosynaptic transmission during epileptiform activity induced by penicillin in hippocampal slices in vitro.

Synaptic transmission was studied in the CA1 region of transverse hippocampal slices in vitro before and after the addition of the epileptogenic agent sodium benzyl penicillin. The presynaptic fibre volley and the field potential associated with the intracellular EPSP, 'field EPSP', were recorded from the layer of the activated synapses. Addition of penicillin did not change either response. The rising phase of the intracellularly recorded EPSP did not change. However, the peak amplitude and, particularly, the duration of the EPSP both increased. The prolongation of the EPSP may be of importance for the triggering of epileptiform bursts.

Evoked Potentials↗
PubMed1981

Antibodies to lens antigens in cataract and after cataract surgery.

By means of an enzyme-linked immunosorbent assay (ELISA) antibodies to whole lens homogenate were found in 50.0% of 38 patients with senile cataract and in 57.3% of 75 controls. The antibody titres were in the range of 10-160 in both groups. IgG antibodies occurred in 44.7% of patients and in 45.3% of controls, whereas IgM antibodies were found in 21.1% of the patients and in 40.0% of the controls (not significant). Postoperative uveitis occurred in 5 (31.6%) of 19 patients, who had antibodies in serum prior to the operation and in only 2 (10.5%) of 19 antibody-negative patients (P = 0.10).

Adult↗
PubMed1981

Antibodies to Escherichia coli and serum immunoglobulin levels in epileptics on long-term anticonvulsant therapy.

Antibodies to 11 different Escherichia coli (E. coli) serotypes were determined by indirect haemagglutination in 53 epileptics treated with diphenylhydantoin (DPH) and in 53 matched controls. Agglutinins were found more often and at higher titres in epileptics (83 . 4%) than in controls (51 . 7%) (P less than 0 . 05). No correlation between the occurrence of E. coli agglutinins and the serum concentration or clearance of DPH, or abnormal biochemical liver tests could be established. E. coli antibodies were predominantly of the IgM classes, and the percentage of positive reactions was slightly, but not significantly, higher in epileptics with elevated serum IgM (88 . 2%) than in those with normal IgM (83 . 1%) (0 . 20 greater than P greater than 0 . 10). The increased incidence of E. coli agglutinins could not be explained by a low serum IgA concentration which may suggest an impaired secretory immune function. The incidences of positive reactions in epileptics with subnormal (less than 37 mg/100 ml), normal (37-285 mg/100 ml) and elevated (greater than 285 mg/100 ml) serum IgA values were 73 . 7, 84 . 7 and 93 . 7% respectively (0 . 01 greater than P greater than 0 . 001). It is suggested that DPH can both suppress and stimulate the humoral immune response in humans, and that genetic or acquired factors may be of importance for the development of modified immune responses.

Adolescent↗