Showing papers by "Uppsala University published in 1976"

Establishment and characterization of a human histiocytic lymphoma cell line (U‐937)

Abstract: A human hematopoietic cell line (U-937) with exceptional characteristics was derived from a patient with generalized histiocytic lymphoma. The morphology of the cell line was identical to that of the tumor cells in the pleural effusion from which the line was derived. Since Epstein-Barr virus (EBV) carrying diploid lymphoblastoid cell lines unrelated to the tumor population often become established in vitro from non-Burkitt lymphoma explants, several parameters were studied to discriminate the U-937 from such lines: morphology in vitro, growth characteristics, cytochemistry, surface receptor pattern, Ig production, lysozyme production, beta2-microglobulin production, presence of EBV genome and karyotype. In all these respects U-937 differed from prototype lymphoblastoid cell lines. The histiocytic origin of the cell line was shown by its capacity for lysozyme production and the strong esterase activity (naphtol AS-D acetate esterase inhibited by NaF) of the cells. It is therefore concluded that the U-937 is a neoplastic, histiocytic cell line.

Characteristic chromosomal abnormalities in biopsies and lymphoid‐cell lines from patients with burkitt and non‐burkitt lymphomas

Abstract: The karyotypes of cells from 10 Burkitt lymphoma (BL) biopsies, eight cell lines established from BL and nine cell lines from non-BL sources were studied by chromosome banding techniques. With the exception of the BL-derived cell lines BJAB, GC-BJAB, Maku and U-8691 all biopsies and lines of Burkitt origin contained an extra band at the distal region of the long arm of one chromosome 14. An extra band on chromosome 14 was also found in cells of one non-BL biopsy, in cells from a lymphosarcoma-derived cell line and in a long-established cell line derived from the pleural exudate of a patient with Hodgkin's disease. A distal region at the long arm of one chromosome 8 was missing in all metaphase figures of good technical quality in the same material. The size, morphology and stain-ability of the missing region corresponded fairly well to the extra region at chromosome 14. We therefore suggest that the chromosome 14 marker represents a translocation between chromosomes 8 and 14,t (8q-; 14q+). The translocation was present neither in lymphocytes of the peripheral blood of five Burkitt patients nor in five lymphoblastoid cell lines of non-BL origin. Trisomy 7 was found in two of the 10 BL biopsies, in two BL-derived cell lines, in one non-BL biopsy, in two lymphosarcoma-derived cell lines and in one cell line derived from a patient with Hodgkin's disease.

Identification of Processes in Closed Loop -- Identifiability and Accuracy Aspects

Abstract: It is often necessary in practice to perform identification experiments on systems operating in closed loop. There has been some confusion about the possibilities of successful identification in such cases, evidently due to the fact that certain common methods then fail. A rapidly increasing literature on the problem is briefly surveyed in this paper, and an overview of a particular approach is given. It is shown that prediction error identification methods, applied in a direct fashion will given correct estimates in a number of feedback cases. Furthermore, the accuracy is not necessarily worse in the presence of feedback; in fact optimal inputs may very well require feedback terms. Some practical applications are also described.

Spatio-temporal differentiation and integration in visual motion perception. An experimental and theoretical analysis of calculus-like functions in visual data processing.

Abstract: Perceptual organization during short tachistoscopic presentation of stimulus patterns formed by ten moving bright spots, representing a human body in walking, running, etc. was investigated. Exposure times were .1 sec to .5 sec. The results reveal that in all Ss the dot pattern is perceptually organized to a “gestalt”, a walking, running, etc., person at an exposure time of .2 sec. 40% of Ss perceived a human body in such motion at presentation times as short as 0.1 sec. Under the experimental conditions used the track length of the bright spots at the threshold of integration to a moving unit was of the size order 10′ visual angle. This result is regarded as indicating that a complex vector analysis of the proximal motion pattern is accomplished at the initial stage of physiological signal recording and that it is a consequence of receptive field organization. It is discussed in terms of vector calculus.

Effects of Secretagogues on Oxygen Consumption, Aminopyrine Accumulation and Morphology in Isolated Gastric Glands

Abstract: A recently developed method to isolate gastric glands from the rabbit gastric mucosa (Berglindh and Obrink 1976) was used to study the effects of some common gastric secretagogues. Three parameters were investigated: 1) Respiratory activity; 2) Intraglandular accumulation of the weak base aminopyrine; 3) Quantitative morphology of the parietal cells. The following substances were tested: Histamine, cAMP, db-cAMP, aminophylline, carbachol and pentagastrin. The strongest effect was obtained with db-cAMP which dose-dependently stimulated the respiration up to 200%, increased the aminopyrine accumulation 80% and altered the parietal cell morphology from a typically resting to a typically stimulated state. cAMP also stimulated the respiration but was about 10 times less effective on a molar basis than the dibutyryl form. Histamine, like db-cAMP, stimulated the respiration in a dose-dependent manner and strongly increased the aminopyrine accumulation. The morphological changes were, however, not of the same magnitude as after db-cAMP. Aminophylline, tested only for respiratory activity, stimulated the oxygen consumpation moderately. Carbachol induced a transient increase in both the oxygen consumption and in the aminopyrine accumulation with a peak value after approximately 15 minutes for both, but gave no significant morphological alterations. Pentagastrin, finally, was incapable of inducing changes in any of the three parameters. Aminopyrine was also found to accumulate approx. 50 times in unstimulated, morphologically resting glands. This seems to indicate that there might be acid sites already in resting glands.

A method for preparing isolated glands from the rabbit gastric mucosa.

Abstract: A method for isolating gastric glands from the corpus of the rabbit gastric mucosa is presented. The stomach of an anesthetized rabbit was perfused with saline under high pressure through the aorta, taken out and emptied. The mucosa was stripped off, minced into small pieces and transferred to a 1 mg/ml collagenase solution. After 90 min at 37 degrees C, a large number of isolated gastric glands and cells were separated free. By a simple washing procedure the glands were freed from cell contamination and collagenase. The gastric glands were viable, as demonstrated by dye exclusion technique, oxygen consumption and electrolyte content. For identification of the glandular cells both common staining techniques and electron microscopy were used. Four types of cells were identified, viz. parietal cells, zymogen cells, mucous neck cells and some endocrine cells. The intracellular morphology of the glandular cells did not differ significantly from that seen in intact gastric mucosa. The glands could be stimulated with histamine, in a dose-response manner, as revealed by the increase in oxygen consumption (ED-50 equal 3 X 10(-6) M). This isolated gastric gland preparation may serve as a useful tool for new approaches in gastric physiology.

Sympathetic control of cerebral blood flow in acute arterial hypertension.

Abstract: The cervical sympathetic chain on one side was stimulated electrically at 10-20 Hz and an acute rise in arterial blood pressure was produced by: intravenous injection of angiotensin, ligation of the thoracic aorta, or ligation of the aorta combined with injection of metaraminol. The blood flow through the cerebrum and the cerebellum was determined by using labelled microspheres. At high blood pressures there was multifocal breakdown of the blood-brain barrier in the cerebrum as indicated by leakage of Evans blue. The breakdown was restricted to the control side or much more marked on that side than on the stimulated side. Sympathetic stimulation prevented also breakdown of the blood-aqueous barrier. The blood flow through the cerebrum on the control side was higher than that on the stimulated side in all experiments. Regions with breakdown of the blood-brain barrier had flow rates which were about 10 times normal values. Cerebellar blood flow was less affected by the hypertension and did not react significantly to sympathetic stimulation. The results indicate that stimulation of the sympathetic nerves to the brain tends to prevent forced dilatation of the arterioles with a resulting regional overperfusion with blood and breakdown of the blood-brain barrier. It is concluded that one role of the sympathetic nerves supplying the brain is to extend the pressure region with autoregulation in its upper part under conditions of a general increase in sympathetic vasomotor activity.

Lymphocyte stimulation by protein A of Staphylococcus aureus.

Abstract: Protein A from Staphylococcus aureus (SpA) is known to bind to the Fc region of most mammalian IgG classes. In the present article data are presented showing that SpA is a highly efficient mitogen for human peripheral B lymphocytes, with no detectable activity for T lymphocytes. In order to achieve optimal stimulating conditions SpA should be presented to the lymphocytes on an insoluble matrix, such as the SpA-positive bacteria themselves or SpA covalently attached to Sephadex or Sepharose beads. Using such conditions SpA is equivalent with regard to stimulatory capacity for B lymphocytes as phytohemagglutinin is for the human T lymphocytes. Specificity controls proved beyond doubt that SpA and not any other contaminating product is the B cell mitogen. It is concluded that SpA as an inducer of human B lymphocyte division might serve as a highly useful assay in the clinical assessment of B lymphocyte function. It should also be a suitable tool in the fine analysis of B lymphocyte activation via the specific interactions with surface IgG molecules.

Unrelated animal viruses share receptors.

Abstract: THE specific receptors for several non-enveloped viruses are present on cells in only limited numbers (1 × 104–10 × 104), and can therefore be saturated with excess virus1–5. An excess of inactivated poliovirus type 1 inhibits the attachment of infectious poliovirus of all 3 serotypes, but not the attachment of other viruses, including B Coxsackie viruses6. Most of the B Coxsackie viruses probably share the same receptor7, but Coxsackie viruses B1 and B3 do not compete for the poliovirus receptor1. Adenovirus 2 and 5 also appear to share the same receptor, since their attachment to host cells is blocked by an excess of the adenovirus type 2 fibre protein, which seems to be the receptor-recognising portion of the virus particle2. A number of other adenoviruses may also belong to the same receptor family since soluble antigens block their attachment to erythrocytes8. We here report results which permit the construction of a ‘receptor map’ for a number of non-enveloped viruses.

Killer cells: a functional comparison between natural, immune T-cell and antibody-dependent in vitro systems.

Abstract: Previous reports have shown that spleen cells from nonimmune adult mice of certain strains do regularly kill Moloney leukemia virus-induced lymphomas in short-term 51Cr release assays. This naturally occuring killer (NK) cell had low adherent properties and had the morphological appearance of a lymphocyte. Still it lacked surface characteristics of mature T or B lymphocytes. In the present report a functional study was carried out, comparing in parallel the NK system, the T-cell killing across an H-2 barrier (anti-P815), and the antibody-dependent cell-mediated chicken red blood cell (CRBC) system. In contrast to the effector cells in the CRBC system, the NK cells were insensitive to erythrocyte antibody complement (EAC) rosette depletion and would pass through nylon wool columns. NK activity was not inhibited by the presence of heat-aggregated human or mouse gamma globulin, in contrast to the strong inhibition noted in the CRBC system. Sensitivity to trypsin pretreatment was noted in the NK system as well as in the immune P815 system, whereas the CRBC system was relatively trypsin resistant. Antitheta plus complement eliminated the anti-P815 activity, but did not touch the NK activity. The present results thus further distinguish the NK cell from cytotoxic T lymphocytes or from antibody-dependent killer cells.

Shared idiotypic determinants on B and T lymphocytes reactive against the same antigenic determinants. V. Biochemical and serological characteristics of naturally occurring, soluble antigen-binding T-lymphocyte-derived molecules.

Abstract: Normal rat lymphocyte populations house a high percentage of lymphocytes with idiotypic, antigen-binding receptors for the major histocompatibility complex antigens of the rat. These receptors can be isolated from normal serum or lymphocyte supernatants. Idiotypic, antigen-binding molecules released from normal Lewis lymphocytes were thus isolated using anti-(Lewis anti-DA) immuno adsorbents. Analysis by SDS polyacrylamide electrophoresis using molecules labeled by external or internal means (125I or 3H) demonstrated that B lymphocytes produce molecules of 'conventional' 7S-8S IgM type. T-lymphocyte-derived molecules had a molecular weight of around 150,000 and consisted of two chains of similar size. Such single chains would succumb to proteolysis by normal serum factors to yield fragments in the size range of 30,000-40,000 daltons. All three groups of T-cell-derived molecules expressed both antigen-binding and idiotypic markers. No evidence was obtained that any light chains are linked to the T-receptor molecules. Serological analysis of the T-cell molecules failed to prove the existence of any determinants of constant immunoglobulin type, nor did these molecules express antigenic markers of major histocompatibility complex types.

Martensite decay during rolling contact fatigue in ball bearings

Abstract: During rolling contact fatigue of ball bearings structural changes may occur below the raceway, in the region of maximum shear stress. A great number of 6309 type bearings were tested at two stress levels for varying numbers of revolutions, and the resulting structural changes in the inner rings were studied by optical and electron microscopy. The present observations have been compared to previously reported observations, which are often described in unsystematic terminologies and sometimes apparently contradictory. A unified terminology is worked out, on the basis of which, the structural changes are described. The following features occur, in chronological order. i) A ferritic phase, containing an inhomogeneously distributed excess carbon content, corresponding to that of the parent martensite. A mixture of this phase with residual martensite constitutes the well known dark etching region. ii) Disc-shaped regions of ferrite, thermodynamically stable, about 0.1 μm thick, inclined by about 30 deg to the raceway, and sandwiched between carbide rich discs. The latter are constituted by very small carbide particles, and are not necessarily compact. iii) A second set of larger disc-shaped regions about 10 μm thick, of plastically deformed ferrite in thermodynamic equilibrium, forming an angle of about 80 deg to the raceway. Transformation mechanisms are proposed. Particular attention is paid to short range carbon diffusion, induced by the cyclic stresses.

Clonidine antinociceptive activity: effects of drugs influencing central monoaminergic and cholinergic mechanisms in the rat.

Abstract: Clonidine is able to increase the threshold for vocalisation during stimulation and the threshold for vocalisation after withdrawal of stimulus (vocalisation afterdischarge). These effects of clonidine were investigated after treatment of rats with drugs influencing central monoaminergic and cholinergic mechanisms.