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Biomedical subjects

P Andersen

Publications and source records attributed to P Andersen.

At least 325 records · Page 18Linked to original sources
PubMed1977

Correlation of smooth-muscle and nuclear antibodies in normal subjects.

By means of the indirect immunofluorescent method the occurrence of smooth-muscle antibodies (SMA) was studied in 582 normal subjects of different ages, and the incidence of SMA was compared with that of anti-nuclear antibodies (ANA). SMA were detected in 32 (5-5%) and ANA in 28 (4-8%) of the normal subjects. The antibodies were of the IgG and the IgM class, while no IgA antibodies could be detected. IgM-SMA were demonstrated in 2-9%, IgM-ANA in 4-1% and IgG-ANA in 1-2% of the 582 subjects, and the incidence of these antibodies increased with increasing age (P = 0-012, P less than 0-001 and P = 0-003, respectively). IgG-SMA occurred in 3-6% and the prevalence of these antibodies was not age-related. No relationship between the incidence of antibodies and sex could be established. IgM-SMA and IgM-ANA were often found together in the same individuals (P = 0-002), which suggests that the same factors may elicit the formation of both antibodies.

Adolescent↗
PubMed1976

Hyperlipidaemia and reduced fibrinolytic activity associated with thromboembolic complications in a family.

Although not significantly correlated, the occurrence of reduced fibrinolytic activity and capacity in hyperlipidaemics has often been described. Hyperlipidaemia and reduced fibrinolysis might well enhance the possibility of thromboembolism. Such a coincidence of risk factors has probably caused thrombotic disease in a family, as described in this case report and family investigation.

Adolescent↗
PubMed1976

On the solubility of zinc in the gamma-phase of the silver-mercury system.

By measuring lattice constants of a number of Ag-Hg-Zn alloys with gamma-phase structure, it has been shown that apart from a possible two-phase field there exists a continuous solid solution between gamma (Ag-Hg) and gamma (Ag-Zn). A correlation between the Zn-content in the gamma 1 phase in set dental silver amalgam and the Zn-content in the corresponding alloy has been determined.

Alloys↗
PubMed1976

Smooth-muscle antibodies and antibodies to cytomegalovirus and Epstein-Barr virus in leukaemias and lymphomata.

By means of the indirect immunofluorescent method, smooth-muscle antibodies (SMA) were detected significantly more often in patients with malignant diseases (11.7%) than in normal controls (3.3%) (0.02 greater than pgreater than 0.01). SMA occurred in 23.8% of patients with Hodgkin's disease, in 13.3% of patients with myeloproliferative diseases and in 4.7% of patients with lymphoproliferative diseases. Other tissue antibodies were rare and they were found to occur at the same frequency in patients and controls. The occurrence of cytomegalovirus (CMV) antibodies did not differ significantly in patients and controls and, in both groups, the frequency of these antibodies increased with increasing age. The frequency of Epstein-Barr-virus (EBV) antibodies increased also with increasing age both in patients and controls, but these antibodies were found more frequently in patients than in controls (p=0.03). No relationship between the occurrence of SMA and viral antibodies was demonstrated. Thus, the development of SMA in patients with malignancies could not be shown to be due to CMV or EBV infection.

Adolescent↗
PubMed1976

Studies of smooth-muscle antibodies in acute hepatitis.

Smooth-muscle antibodies (SMA) of the IgG and IgM class in titres of 10 to 80 were demonstrated in 19 of 38 patients with acute hepatitis (50 per cent). No IgA-SMA were detected. IgM-SMA occurred in the beginning of the disease, while IgG-SMA were found both early and late in the course of disease. There was no correlation between the occurrence of SMA and the biochemical liver parameters or the mode of exposure to infection, but IgM-SMA were found more often in the first serum sample obtained from patients without hepatitis-B-associated antigen (HBAg) than in HBAg-positive patients (P1 + P2 = 0.04) and it is suggested that hepatitis virus A more readily than hepatitis virus B can elicit the formation of SMA. The mean PHA-induced lymphocyte-transformation response was significantly lower in hepatitis patients than in the controls (0.02 greater than p greater than 0.01). The lymphocyte-transformation response to a low PHA dose (1 mug per ml) was lower in hepatitis patients without SMA than in those with SMA (0.10 greater than p greater than 0.05). SMA were not found in 28 control persons, and the incidence of tissue antibodies other than SMA did not differ in hepatitis patients and controls.

Acute Disease↗
PubMed1976

Studies on the specificity of smooth-muscle antibodies.

Purified contractile proteins from smooth and striated muscles have been used to test the specificity of human smooth muscle antibodies (SMA) from patients with chronic liver disease (IgG-SMA) and acute hepatitis (IgM-SMA). The reactions, as detected by indirect immunofluorescence, of IgG-SMA with renal vessel walls, renal glomeruli, peritubular fibrils and the luminal part of the tubular cells could be completely abolished by absorption with either smooth muscle or skeletal muscle F-actin, while absorption with myosin and tropomyosin had no effect. The specificity of IgG-SMA for actin was confirmed by their staining of the actin-rich I-bands of skeletal muscle myofibrils and by the blocking of this reaction by pretreatment of myofibrils and isolated smooth muscle cells with smooth muscle myosin subfragment 1 (S-1). IgM-SMA from patients with acute hepatitis-stained renal vessel walls and some sera also stained renal glomeruli. The IgM-SMA titres decreased after absorption both with myosin and F-actin but not with tropomyosin. The reactivity of some IgM-SMA could be blocked by S-1 while others could not. Thus the specificity of IgM-SMA seemed to be variable, and apparently differed from IgG-SMA in some cases.

Absorption↗
PubMed1976

Lymphocyte transformation test with liver-specific protein and phytohaemagglutinin in patients with liver disease.

Lymphocytes from thirty-four untreated patients with various liver diseases were stimulated in a lymphocyte transformation test with liver-specific protein (LSP). Eight of ten patients with chronic active or persistent hepatitis, two of five patients with non-alcoholic cirrhosis and six of nineteen patients with acute hepatitis showed a positive in vitro reactivity to LSP. In a control group of twelve persons without evidence of liver disease, eleven gave a negative response to LSP stimulation, whereas one person showed a positive response. Among fourteen patients with chronic hepatitis or non-alcoholic cirrhosis treated with prednisone at the time of the investigation, only one showed reactivity to LSP stimulation. Three patients in this group had previously had a positive reaction before prednisone was given. There was no statistically significant correlation between the reactivity to LSP stimulation and the presence or absence of hepatitis-associated antigen (HBAg) in serum, or with the biochemical liver parameters. The response to in vitro stimulation with phytohaemagglutinin (PHA) was found to be significantly lower as compared with the control group in eleven patients with alcoholic liver disease and in the patients with acute hepatitis who had HBAg in serum. This decrease in reactivity could apparently not be ascribed to immuno-suppressive factors in the patients' sera.

Acute Disease↗
PubMed1975

Barbiturate spindle activity in functionally corresponding thalamic and cortical somato-sensory areas in the cat.

(1) Spontaneous barbiturate spindles were recorded from a locus in the thalamic nucleus ventralis postero-lateralis (VPL) and the corresponding projection area in the somato-sensory cortex (SI) in the cat. (2) Type I spindles32 recorded from such sites in the thalamus and cortex, regarded as being functionally on line, were cross-correlated. The analysis gave high negative cross-correlation coefficients, indicating that a considerable degree of wave synchrony existed between the spindles. Maximal wave synchrony was present in the first and middle part of the spindle. (3) The thalamo-cortical spindle wave synchrony was reduced by a small displacement of the cortical electrode within the somato-sensory cortex. Starting with a very lightly anaesthetized animal, small amounts of barbiturate did not influence the size of the cortical area which had spindles in synchrony with the thalamic spindles. (4) Spindles recorded from a VPL locus and from its cortical projection site started simultaneously. When the thalamic and cortical electrodes were positioned functionally off line this spindle coincidence decreased. The intervals between the spindle onsets increased with increasing off line positions of the electrodes. Those few thalamic and cortical spindles which occurred simultaneously showed no, or only weak, spindle wave synchrony. (5) These data suggest a point-to-point topographical relation between thalamic and cortical loci engaged in barbiturate spindle activity. (6) Type I and type II spindles32 differed with respect to spindle characteristics (amplitude, duration, incidence) and also with respect to corresponding thalamic rhythmic activity. These spindle types are, therefore, probably produced by different mechanisms. We suggest that type II spindles represent a purely cortical process initiated by type I spindles.

Animals↗
PubMed1975

Studies on defined immunofluorescence in clinical immunopathology. III. Past progress, some new methods, and prospects for the future.

Experience with chessboard titrations over the past 9 years has shown that essentially all indirect IF staining systems that employ anti-IgG conjugates can be defined with the aid of assays for F/P ratios and/or antibody concentrations. Some improvements in the radial diffusion assays for antibody protein have been effected by refinements in methodology. Studies with a form of the Dass system showed that over a 16-fold range of light intensities, relatively little change occurred in "titers" of IgG (comparably to titers of patient sera) or in PEP conjugates as seen in DASS chessborad titrations. An analysis of 233 PEP values included in 12 literature reports on indirect IF tests indicate that 88% fall within one doubling dilution of 1/16 unit/ml or about 12.5 mug labeled Ab/ml. The DASS reactions also are within this range. Factors responsible for variation beyond these limits in indirect IF tests were analyzed. The most important factor appears to be experimental errors. Other factors include low titers of primary antibodies, some aberrant conjugates, and a recent shift toward greater sensitivity of chessboard titrations. The latter appears to be due primarily to modes of reading and should be controlled by the constant use of reference sera. It now seems possibe that future IF studies may be defined with the aid of this DASS system. To achieve this goal, it will be necessary to not only elaborate microanalytic techniques of the type that have been considered at this Conference but also to generate macroanalytic methods that can be used in parallel with them as a basis for interpreting microscopic observations both in the DASS system and in IF studies of sera and tissues.

Animals↗
PubMed1975

Predictable reduction in anticoagulant activity of warfarin by small amounts of vitamin K.

After withdrawal of warfarin (Marevan), 48-72 hours are required to raise the Thombotest values from a therapeutic level (range 5-10%) to 12% or higher. By i.v. administration of 1 mg vitamin K1 (Konakion) and without changing the dose of the anticoagulant, this effect could be obtained within 24 hours. Furthermore, the effect of vitamin K vanished within 2-5 days. The use of small amounts of vitamin K may therefore be a simple and reliable way of obtaining a rapid, temporary reduction in anticoagulant effect.

Blood Coagulation↗
PubMed1975

The location of zinc in dental silver amalgam.

The phases in amalgams prepared from alloys of varying zinc content and with varying alloy-to-mercury ratios have been determined by means of X-ray diffraction. By measuring lattice constants of the phases in these amalgams it has been established that the major part of the zinc is dissolved in the gamma1 phase.

Dental Alloys↗