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Biomedical subjects

P Andersen

Publications and source records attributed to P Andersen.

At least 253 records · Page 14Linked to original sources
PubMed1983

Antibodies against Aspergillus fumigatus in bronchial secretions from patients without aspergillosis.

Antibodies to Aspergillus fumigatus were investigated by indirect immunofluorescence (IIF) and enzyme-linked immunosorbent assay (ELISA) in bronchial secretions (BS) and sera from 40 patients with neoplasia, lung infiltrates of non-fungal aetiology or chronic bronchitis. By IIF, IgG aspergillus antibodies were found in 23 samples of BS (58%) (titre range 10-40) and in all 40 sera (titre range 10-1280). IgA aspergillus antibodies were detected in 33 samples of BS (83%) (titre range 10-160) and in 33 sera (83%) (titre range 10-40). IgM aspergillus antibodies occurred in 2 samples of BS (5%) (titre 10 and 40) compared with 35 sera (88%) (titre range 10-40). Antibodies with secretory component (SC) were detected in 20 of 39 BS samples tested (51%) (titre range 10-160). Significantly higher levels of IgA antibodies were detected by ELISA in BS than in serum (2p less than 0.05) and, conversely, significantly higher levels of IgG antibodies were found in serum than in BS (2p less than 0.001). Low levels of antibodies with SC were also detected in BS by ELISA. These results suggest that aspergillus antibodies are produced within the bronchopulmonary system in patients without aspergillosis.

Antibodies, Fungal↗
PubMed1983

Epidermal nuclear immunoglobulin deposits in some connective tissue diseases: correlation with ENA antibodies.

In-vivo nuclear deposits of IgG were demonstrated by direct immunofluorescence in epidermal cells of normal skin from 6 patients with serum antibodies to an RNase-sensitive extractable nuclear antigen (ENA). Addition of complement to the skin sections showed that C3 could bind to epidermal cells with IgG deposits. A skin biopsy from a patient with polymyositis and serum antibodies to ENA, but without nuclear IgG deposits, showed nuclear binding of C3 after addition of complement to the skin sections. The clinical diagnoses of patients with immunofluorescent staining of epidermal cells were mixed connective tissue disease (MCTD) 4 cases, systemic lupus erythematosus (SLE) 2 cases, and polymyositis 1 case. No epidermal nuclear IgG deposits could be demonstrated in 5 cases of SLE, 2 cases of MCTD, one case of polymyositis, or 15 cases of rheumatoid arthritis without antibodies to ENA.

Adult↗
PubMed1983

Summation of excitatory postsynaptic potentials in hippocampal pyramidal cells.

The summation of excitatory postsynaptic potentials (EPSPs) generated in separate parts of the dendritic tree of hippocampal pyramidal cells has been investigated using the in vitro slice preparation. Two separate inputs with known synaptic location were used. The EPSP produced by simultaneous activation of the two inputs (observed sum) was compared to the algebraic sum of the individual EPSPs. Small-amplitude EPSPs (0.5-1.5 mV) added linearly. The shortest distance between the two synaptic groups was 75 micron. With larger amplitudes (greater than 2.5 mV), the EPSP summated nonlinearly. The nonlinear summation was reduced by moderate hyperpolarizations (2-10 mV) of the soma membrane. Also, large EPSPs (greater than 2.5 mV) summated linearly when the peak of the summed EPSP was brought close to the equilibrium potential for the inhibitory postsynaptic potential (IPSP) (EIPSP). When the EPSP peak was made more negative than the EIPSP, summation was again nonlinear but the algebraic sum was now smaller than the observed EPSP sum, i.e., the direction of the nonlinearity was reversed. EPSP summation was linear after the IPSP had been blocked by benzyl penicillin application. We conclude that separate EPSPs in hippocampal pyramids (minimal separation, 75 micron) add linearly but that the addition of an IPSP may complicate this picture. No evidence was found for interaction between the different populations of excitatory synapses.

Animals↗
PubMed1983

Determination of antibodies to partially purified aspergillus antigens by an enzyme-linked immunosorbent assay.

A total of 75 sera from 17 patients with pulmonary aspergillosis and 58 controls were investigated by ELISA for IgG antibodies against different antigen fractions of Aspergillus fumigatus. Somatic antigen obtained by homogenization of young hyphi was fractionated on a Sephadex G-200 column, and 11 antigen fractions (I-XI) were prepared. Antibodies to fractions I-XI were detected in sera from patients with aspergillosis, whereas antibodies in sera from control patients and healthy blood donors were directed against only 7 fractions (I-VII). Antibodies against fraction VIII with an approximate molecular weight of 70,000 appeared to be of high diagnostic significance for pulmonary aspergillosis.

Adolescent↗
PubMed1983

Serum antibodies to Aspergillus fumigatus in patients with rheumatic diseases.

IgG and IgA serum antibodies to Aspergillus fumigatus were determined in 47 patients with rheumatic disorders, 4 patients with pulmonary aspergillosis associated with rheumatic disease, and in 36 healthy controls. Antibody titres determined by indirect immunofluorescence were comparable in patients with rheumatic diseases and in controls, except for 2 patients with IgG antibody titres within the upper range of patients with aspergillosis. IgG antibody levels to 2 partially purified A. fumigatus antigens (I and VIII), determined by enzyme-linked immunosorbent assay (ELISA), were higher in rheumatic patients than in controls and with antigen VIII the difference reached statistical significance for all subgroups of rheumatic patients. IgA antibody levels by ELISA were also increased in rheumatic patients compared with the control group: IgA levels against antigen I fell within the range of patients with aspergillosis in 7 patients with rheumatic disorders. This suggests that some rheumatic patients are more strongly sensitized to Aspergillus antigens than normal subjects.

Adolescent↗
PubMed1983

Basic mechanisms of penicillin-induced epileptiform discharges.

A short survey is given of recent studies on epileptogenesis, concentrating on data obtained by adding penicillin to hippocampal slices in vitro. Epileptiform burst discharges, similar to the interictal responses of intact preparations, are elicited by synaptic activation. Neither the afferent fibres nor the synaptic transmission per se are changed. Excitatory synaptic potentials are, however, prolonged due to abolition of gamma-aminobutyric acid (GABA)-mediated inhibitory processes. The consequent increased membrane resistance allows the synaptic depolarization to trigger slow depolarizing waves, most likely in the dendrites. A possible explanation is that these waves are due to inward calcium currents, generated when the cell is in a special condition which facilitates such currents. The facilitatory factors are discussed.

Action Potentials↗
PubMed1982

Detection of respiratory syncytial virus in nasopharyngeal secretions by ELISA: comparison with fluorescent antibody technique.

Samples of nasopharyngeal secretions (NPS) obtained from 140 infants and children with acute respiratory disease were examined for the presence of respiratory syncytial (RS) virus by ELISA. An antiserum produced in rabbits against RS-virus polypeptides was used both as the "capture" antibody and as conjugate in a double-antibody sandwich technique. RS virus was detected by ELISA in specimens of NPS obtained from 72 (51%) of the patients. By comparison RS virus was shown to be present in 86 (61%) of the patients when the immunofluorescent antibody (IF) technique was employed. Samples obtained from 78 of the 140 patients were also examined by inoculation into tissue cultures, and RS-virus was isolated from 47 patients. RS virus was detected by ELISA in 37 (79%) and by IF technique in 43 (91%) of these 47 patients. The IF technique was found to be more sensitive than ELISA, especially in patients older than 9 months and for the examination of specimens of NPS containing only a small percentage of RS-virus antigen-positive cells.

Animals↗
PubMed1982

Effect of sodium ions on penicillin-induced epileptiform activity in vitro.

Intra- and extracellular recordings were obtained from the CA1 region of guinea pig hippocampal slices maintained in vitro. We studied the effect of reducing the extracellular sodium concentration on penicillin-induced epileptiform responses. In control experiments, Tris and choline were assayed as sodium substitutes. Choline was found unsuitable, since it induced repetitive firing in the absence of any convulsant agent. Replacement of 50% of the extracellular sodium ( [Na+]o) with Tris reduced the amplitude of the presynaptic fiber volley, the field EPSP, and the population spike. Intracellular studies showed that when [Na+]o was lowered, action-potential amplitudes were reversibly depressed by an amount close to that predicted by the Nernst relation. Orthodromically elicited epileptiform discharges, induced by penicillin, were reduced in a low-sodium medium when constant stimulus currents were employed. If orthodromic stimulus strengths in normal and low-sodium states were equated on the basis of the field-EPSP amplitude, no significant diminution of the depolarizing-wave component of the epileptiform response was observed. These results suggest that a synaptic component underlies penicillin-induced epileptiform discharges.

Animals↗
PubMed1982

Distribution of GABA sensitive areas on hippocampal pyramidal cells.

In isolated transverse hippocampal slices GABA (gamma-amino-butyric acid) was applied iontophoretically to various parts of the dendritic tree of CA1 pyramidal cells. Indices of GABA effects were reduced amplitude of orthodromically driven CA1 population spikes and inhibition of single CA1 units driven by orthodromic stimulation or by application of L-glutamate. Weak iontophoretic currents of GABA (3-6 nA, backing current -3 nA) effectively reduced the amplitude of the population spike and arrested unit activity when applied in a position close to the soma. The effect was halved when GABA was applied 25-30 micrometer away at right angles to the main dendritic axis. In the direction of the main dendritic axis, GABA was affective as far as 250 and 150 micrometer from the soma in the apical and basal dendritic directions, respectively, corresponding to about 50% of the total dendritic length. The best effect was usually found at a depth corresponding to that of the recording electrode, probably because the main dendritic axis was parallel to the slice surface. The sharp localization of GABA sensitivity when applied in the pyramidal layer supports earlier evidence that GABA mediates the basket cell inhibition on the soma of the pyramidal hippocampal cells. In the dendritic tree, GABA may also have an inhibitory function with an effectiveness matching that of the soma application.

Animals↗
PubMed1982

Intrinsic asthma and bacterial histamine release.

In this study of intrinsic asthma (IA) in children the pathogenic role of bacteria in respiratory disease was elucidated by a basophil histamine liberation technique. Several strains of bacteria caused release of histamine from peripheral leukocytes in vitro. Normal, non-infectious and non-atopic children frequently responded in a similar fashion, although positive responses were less frequent. It seems that two different mechanisms of bacterial histamine release exist: interaction with the basophil-bound IgE and a direct interaction with the cell surface. It is suggested that the histamine release takes place only in the lung of IA patients, where a defective pulmonary barrier could permit the bacteria to enter, but not in healthy individuals.

Adolescent↗
PubMed1982

Studies on hypersensitivity to bacterial antigens in intrinsic asthma.

Twelve children, aged 4 to 14 years, with moderate to severe intrinsic asthma (IA) were studied. Symptom-Score charts were used to confirm the relationship of acute respiratory tract infections to exacerbations of asthma. Hypersensitivity to eight commonly occurring bacteria from the normal flora of the upper respiratory tract was studied by skin test, by crossed immunoelectrophoresis, and by basophil histamine release in vitro, using ultrasonicates of the bacteria as antigens. Skin tests were all negative. All children contained low titers of precipitating antibodies against most of the bacteria, but in this respect they did not differ from normal children. In contrast, release of histamine was induced in leukocytes from the IA children by all, or most sonicates, while such reactions, were less frequent in control children. The pattern of responses indicated an element of specificity. These was no correlation to precipitating antibodies, or to the microbial flora of the children. Positive responses were characterized by low values of maximal histamine release, and by a tendency to fluctuations with time. Because of these fluctuations, and because the IA children and control children were tested on separate occasions, we cannot be certain as to the real difference between these two groups. Our studies do, however, demonstrate that water-soluble constituents of all the bacterial strains tested were capable of causing the release of histamine in vitro, but that this phenomenon is not restricted to IA. The clinical significance of these findings awaits further investigations on the mechanism(s) of release in vitro by such agents.

Acute Disease↗
PubMed1982

Cytomegalovirus antibodies in epileptics receiving diphenylhydantoin.

Cytomegalovirus (CMV) antibodies were determined by indirect haemagglutination in 53 epileptics receiving long-term diphenylhydantoin (DPH) therapy and in 53 matched controls. Absorption of serum IgG, IgA and IgM performed in 12 sera showed that the antibodies were of the IgG class. A decreased incidence of high CMV antibody titres (greater than or equal to 320) was found in epileptics (11.3%) compared with controls (34.0%) (0.02 greater than P greater than 0.01), whereas antibody titres greater than or equal to 40 were found in 37.7% of epileptics and in 45.3% of controls (n.s.). The CMV antibody incidence and titre range were similar in patients with symptomatic (37.9%) and idiopathic (37.5%) epilepsy, suggesting that the DPH treatment was responsible for the decreased antibody occurrence in patients. No correlation between CMV antibody titres and the serum immunoglobulin levels or the DPH concentration or clearance could be established in the epileptics.

Adolescent↗
PubMed1982

Influence of residual splenic tissue on autoantibodies in splenectomized patients.

In 42 patients splenectomized after injury of the spleen or for non-malignant diseases residual splenic tissue was detected by 99mTc scanning in 19 (Group I) and not detected in 23 (Group II). Autoantibodies detected by the indirect immunofluorescent method occurred in 16 (38%) of the splenectomized patients and in 6 (14%) of 42 age- and sex-matched controls (P less than 0.02). In patients with residual splenic tissue the incidence of autoantibodies did not differ significantly form that in the controls, whereas autoantibodies occurred significantly more often in patients without residual splenic tissue (39%) than inthe corresponding control groups (9%) (P = 0.016). Antibodies to nuclear antigens (ANA), smooth muscle (SMA), reticulin (RetA) and cytoplasm of gastric parietal cells (PA) were detected, and the antibody titres tended to be higher in the patients than in the controls. None of the patients showed any clinical signs of autoimmune disease. These findings indicate that splenectomy disturbs the regulation of autoantibody function, and it is possible that this might be caused by a reduction of the number of T suppressor cells for which the spleen is a major pool. It is suggested that residual tissue may prevent an increased occurrence of autoantibodies in splenectomized patients.

Adolescent↗
PubMed1982

Azathioprine versus prednisone in non-alcoholic chronic liver disease (CLD). Relation to a serological classification.

One hundred and forty-eight patients with non-alcoholic cirrhosis or chronic aggressive hepatitis entered a prospective, unblinded, randomized trial on the effect of azathioprine versus prednisone. For all 148 patients, there were no differences in survival related to the two drugs. In 99 patients the disease was classified as autoimmune, in 23 as posthepatitic, and in 26 as cryptogenic. No significant differences were seen in survival between these three groups of patients and no differences in survival related to the two drugs were registered within any of the groups. The autoimmune group included the patients with the biochemically most active disease, and a statistically significant reduction in activity was obtained with prednisone as well as azathioprine. Most remarkably, the frequencies of the autoantibodies were reduced parallel to the biochemical improvement in these patients. Immunosuppressive treatment was found to be rather ineffective in posthepatic chronic liver disease of type B; however, no signs of activation of the hepatitis B virus were seen.

Adult↗
PubMed1982

Serum antibodies to aspergillus fumigatus in patients with pulmonary aspergillosis detected by immunofluorescence.

Aspergillus antibodies of the IgG, IgA and IgM class were determined by the indirect immunofluorescence (IIF) technique in sera from 11 patients with proven pulmonary aspergillosis (group I), 11 patients with suspected pulmonary aspergillosis (group II), 34 patients with chronic obstructive lung disease (group III), 29 patients with lung infiltrates of non-fungal aetiology (group IV), and 94 blood donors (group V). The antigen was cryostate sections of formaldehyde fixed mycelium. IgG antibody titres above 640 occurred in 73% in group I + II, 12% in group III, 0% in group IV, and 22% in group V. The difference between group I + II and group V was statistically significant (p less than 0.001). IgA antibody titres above 80 were only found in patients in group I + II, suggesting that demonstration of such antibodies may be of diagnostic significance. IgM antibodies in titres between 10 and 160 were found in 100-65% in group I to V. Precipitating antibodies to a culture filtrate antigen occurred in all subjects in group I, in 9 (82%) in group II, and in 1-7% of subjects in group III to V. However, precipitin titres above 2 occurred only in group I and II. No correlation between precipitin titres and IIF titres of IgG and IgA antibodies was obtained, suggesting that the two methods reveal antibodies of different specificities.

Adult↗
PubMed1982

Autoantibodies in patients with acute salpingitis caused by Chlamydia trachomatis.

Autoantibodies were investigated by the indirect immunofluorescence method in 10 women with salpingitis caused by Chlamydia trachomatis and in 22 controls. Smooth-muscle antibodies (SMA) of the IgG and IgM class and IgM-antinuclear antibodies (ANA) were found more frequently in patients with salpingitis than in controls (p = 0.024, p = 0.001 and p = 0.015, respectively), but the titres were low (10-80) in both groups. Other antibodies (IgG-ANA, glomerular antibodies, parietal cell antibodies and reticulin antibodies) were uncommon in both patients and in controls. An in virus and mycoplasma infections IgM-SMA occurred most often in the beginning of the disease.

Acute Disease↗