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Biomedical subjects

J Andersson

Publications and source records attributed to J Andersson.

At least 199 records · Page 11Linked to original sources
PubMed1994

Similar cytokine induction profiles of a novel streptococcal exotoxin, MF, and pyrogenic exotoxins A and B.

The cytokine production induced by a newly discovered streptococcal exotoxin, MF, and the pyrogenic exotoxins SpeA and SpeB was determined by in vitro stimulation of peripheral blood mononuclear cells (PBMCs) obtained from healthy blood donors. The induction and kinetics of interleukin-1 alpha (IL-1 alpha), IL-1 beta, IL-1 receptor antagonist, IL-2, IL-3, IL-4, IL-5, IL-6, IL-8, IL-10, gamma interferon, tumor necrosis factor alpha (TNF-alpha), TNF-beta, and granulocyte-macrophage colony-stimulating factor were studied at the single-cell level by use of cytokine-specific monoclonal antibodies and intracellular immunofluorescent juxtanuclear staining. The cytokine-producing cells, with the exception of IL-1-expressing cells, had a characteristic morphology generated by the accumulation of cytokines in the Golgi organelle. MF, SpeA, and SpeB induced a massive gamma interferon and TNF-beta response in 10 to 16% of the PBMCs after 48 to 96 h of cell stimulation. In contrast, IL-2 and TNF-alpha production was detected in only 1 to 3% of the PBMCs. The induction of a lymphocyte TH2 phenotype response, including production of IL-3, IL-4, IL-5, and IL-10, was weak. However, the monokines, IL-1 alpha, IL-1 beta, IL-1 receptor antagonist, and IL-8, were consistently found and gradually produced, peaking at 24 h in approximately 5 to 8% of the PBMCs. MF showed extensive cytokine- and proliferation-inducing capacities equal to those of SpeA and SpeB, which suggests that MF is also a superantigen. A marked interindividual variation could be noted both in the proliferative response and in the cytokine induction of lymphocytes isolated from different individuals, which may be one explanation for the varying clinical severity noticed during group A streptococcal infections.

Bacterial Proteins↗
PubMed1994

Rapid detection of cytomegalovirus antigen on alveolar cells in bronchoalveolar fluid from transplant patients with cytomegalovirus pneumonia.

Cytomegalovirus-specific mouse monoclonal antibodies and immunomagnetic beads conjugated with sheep anti-mouse immunoglobulin G were used to screen for cytomegalovirus (CMV) antigen expressed on the surface of alveolar cells in bronchoalveolar lavage (BAL) fluid from 23 transplant recipients with interstitial pneumonia. The beads formed rosettes around the cells when CMV antigen was present on the cell surface. Results could be evaluated by light microscopy within 2 hours of receiving the specimen. Cells in BAL fluid obtained from 15 immunocompetent individuals served as controls. Cytomegalovirus antigen was expressed on the surface of the alveolar cells from 12 transplant recipients and detected by this method as rosette formation on 1-8% of the cells. CMV was isolated from culture of cells in BAL fluid and blood from all these patients except 1, while intracellular CMV antigen was detected by monoclonal antibodies and immunofluorescence in 3 only. Serological changes, indicating an active CMV infection, were present in 11/12 patients. One patient with a CMV pneumonia, later confirmed by autopsy, failed to respond with any antibody titer. No rosette formation occurred on alveolar cells from any of the 15 immunocompetent controls. Thus, the method studied appears to be a valuable complement to other diagnostic methods for CMV pneumonia in transplant recipients. When correlated with the isolation of CMV from culture, the sensitivity was 100% and specificity 92%.

Adolescent↗
PubMed1994

Concomitant in vivo production of 19 different cytokines in human tonsils.

Accumulating data indicate that cytokines, peptides involved in regulation of both physiological and pathological immune responses, are produced predominantly at the site of local antigen stimulation. Cytokine-producing cells were detected at the protein level in human tonsil tissue obtained from children with recurrent tonsillitis or infectious mononucleosis (IM). Concomitant production of 19 different human cytokines, interleukin-1 alpha (IL-1 alpha), IL-1 beta, IL-1 receptor antagonist (ra), IL-2, IL-3, IL-4, IL-5, IL-6, IL-8, IL-10, IL-13, granulocyte-macrophage colony-stimulating factor (GM-CSF), G-CSF, tumour necrosis factor-alpha (TNF-alpha), TNF-beta, interferon-gamma (IFN-gamma) and transforming growth factor-beta 1-3 (TGF-beta 1-3), was identified at a single-cell level by indirect immunohistochemical staining procedures and use of carefully selected cytokine-specific antibodies (Ab). Fresh frozen sections were fixed with 4% paraformaldehyde and permeabilized by 0.1% saponin treatment, eluting cholesterol from the cell-surface membrane and the Golgi complex. The intracellular localization of all cytokines, except IL-1 and IL-1ra, was demonstrated by a characteristic local cytoplasmic perinuclear configuration in producer cells. In addition, the immunoreactivity for certain cytokines (IL-2, IL-4, IL-5, G-CSF and GM-CSF) was expressed on the cell membranes and extended over a large extracellular area encompassing the producer cell. Localization of the cytokine to the Golgi organelle was established by co-staining with a monoclonal antibody (mAb) specific to the Golgi complex. Both the extra- and intracellular cytokine staining reactions could be blocked by preincubation of the cytokine-specific Ab with the corresponding purified natural or recombinant cytokine. A complex cytokine pattern was established in both groups studied, where most T-helper type 1 (Th1) and Th2 lymphokines were expressed in the tonsils but at different frequencies and localizations. Cells expressing IL-4, IL-5, IL-10 and IL-13, (Th2 response) were evident at higher frequencies in recurrent tonsillitis compared to sections from IM, which were associated with a more pronounced IL-2, IFN-gamma and TNF-beta expression.

Acute Disease↗
PubMed1993

Suppression of B cell differentiation by ligation of membrane-bound IgM.

Using B cells from the transgenic mouse line B6-Sp6 and control littermates, stimulated by lipopolysaccharide (LPS) under novel culture conditions that provide for the response of all B cells, we show here that specific ligation of the surface IgM molecules always results in inhibition of terminal differentiation and immunoglobulin secretion by activated cells, regardless of the ligand. Thus, monoclonal antibodies to (a) the CH region of Ig (anti-mu and anti-allotype), (b) the C kappa region, (c) the V region (anti-idiotype) of surface IgM, as well as (d) multivalent antigen (2,4,6-trinitrophenyl-bovine serum albumin), all show similar effects and dose-response curves. IgD-negative transgenic B cells are equally sensitive to IgM ligation-dependent inhibition, as control (IgD-positive) B cells. The allotype specificity of this inhibition, assessed by using anti-mu allotype reagents to inhibit and assay the responses, suggests that B cells expressing transgenic or endogenous IgM in transgenic B6-Sp6 mice are largely independent populations. These observations establish that anti-IgM antibodies in conjunction with appropriate LPS stimulation, provide a universal model system for functional characterization of B cell responses.

Animals↗
PubMed1993

Evidence for selective pressure in the appearance of monoclonal immunoglobulins during aging: studies in M54 mu-transgenic mice.

Serum monoclonal immunoglobulins (M-Ig) appear during aging but little is known about the immunological factors which lead to their development. We have investigated whether such M-Ig occur as a clonally random process or result from V-region-directed selective pressures. We have analyzed a mu-transgenic mouse strain in which over 95% of all splenic B cells express the transgenic mu chain. All endogenous repertoire and mu-chain diversity are generated from the 5% of the B cells which express endogenous mu chains. Not one of the M-Ig detected in these mice were of transgene origin alone; 11 of the 14 M-Ig did not express a mu chain and none of the mu chain containing M-Ig expressed the transgene allotype alone. This observation suggests that the B cells giving rise to M-Ig are heavily selected from among the small number of B cells which express endogenous Ig. The selective factors that might act on the endogenous B cell pools are discussed.

Aging↗
PubMed1993

Infections in human liver recipients: different patterns early and late after transplantation.

The first 49 consecutive patients who underwent orthotopic liver transplantation between 1984 and 1989 in our department were studied with regard to symptomatic and asymptomatic post-transplantation infections. The major infections carrying a risk of fatal outcome are presented. During the first 4 weeks, fungal and bacterial infections predominated, the percentages of patients affected being 27% and 35%, respectively. Eight patients (17%) suffered from bacterial septicemia, which in six cases was due to gram-negative micro-organisms. The bacterial septicemia was often associated with severe ischemic damage to the graft, rejection, or cholangitis. In addition, a concomitant invasive fungal infection supervened in seven out of eight septic patients, further aggravating the patients' condition. Seventeen of the 49 patients (35%) died after transplantation within 3.3 years. Infection was the cause of death in nine patients (18%), with bacterial septicemia and/or fungemia in eight of these. Cytomegalovirus (CMV) disease was the dominant cause of illness after the 1st month. While only 5 of the 49 patients developed CMV disease during the 1st month (10%), as many as 16 of the 40 recipients who survived beyond that time suffered from symptomatic CMV viremia (40%). CMV mismatching, i.e., the donation of a CMV-positive organ to a CMV-seronegative recipient, entailed the highest risk for CMV disease. Pneumocystis carinii pneumonia occurred within 4 months in 10% of the patients. The four liver recipients affected were among the 20 patients not receiving trimethoprim-sulfamethoxazole prophylaxis. None of the 28 patients who received this prophylaxis over a 12-month period developed this complication (P < 0.005).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1993

Influenza A in immunocompromised patients.

Immunocompromised patients with influenza A were identified in Stockholm during two influenza seasons. The predominant subtypes were H3N2 during 1988-1989 and H1N1 during 1990-1991. The median age of the 25 patients was 43 years (range, 3-80 years). Twelve patients had received renal transplants and had ongoing immunosuppression. Seven patients had received bone marrow transplants between 2 days and 3 years before becoming infected with influenza virus A. Two patients were in an aplastic phase, and four had chronic graft-versus-host disease with ongoing immunosuppression. Six patients had hematologic malignancies. Two of the 25 patients had severe infections. One of these infections occurred in a bone marrow transplant recipient during an aplastic phase and was fatal; the other affected a patient who had received a renal transplant. One bone marrow transplant patient had mild but protracted infection. The remaining 22 patients had mild influenza A. We conclude that influenza A in immunocompromised patients occasionally causes severe complications but in most patients is mild and self-limiting.

Adolescent↗
PubMed1993

Characterization of cytokine production in infectious mononucleosis studied at a single-cell level in tonsil and peripheral blood.

Cytokine profile and production was studied at a single-cell level in cells obtained from 14 patients with acute infectious mononucleosis (IM), with less than 7 days of symptomatic disease, by use of cytokine-specific MoAbs and indirect immunofluorescence technique. In producer cells, all the studied cytokines, except IL-1, accumulated in the Golgi system, which resulted in a characteristic morphology of the staining. Less than one in a thousand mononuclear cells obtained directly from IM blood and stained within 2 h of sampling produced IL-2, interferon-gamma (IFN-gamma), IL-4, IL-5, IL-6, IL-10, GM-CSF, tumour necrosis factor-alpha (TNF-alpha) or TNF-beta, spontaneously. However, these cells were induced to cytokine synthesis by T cell receptor ligation in vitro using immobilized anti-CD3 MoAbs for 2-3 h restimulation under conditions which did not activate normal cells. By this approach 168 +/- 120 cells/10,000 peripheral blood mononuclear cells produced IFN-gamma as compared with 10 +/- 8 cells/10,000 non-stimulated cultured cells obtained from IM patients (P < 0.001) and 1/10,000 cells obtained from healthy controls, respectively. No induced production of IL-2, IL-3, IL-4, IL-5, IL-10, GM-CSF or TNF-beta was detected in IM cells obtained from peripheral blood by this restimulation. In contrast, a spontaneous cytokine production was evident in tonsil material obtained from four IM patients tonsilectomized because of respiratory obstruction. From this site 160 +/- 40 cells/10,000 cells produced IL-2, 40 +/- 30 cells IL-6, 30 +/- 30 cells TNF-beta and 35 +/- 25 cells IFN-gamma, respectively. No such spontaneous IL-2, IL-6, TNF-beta or IFN-gamma production was evident in control cells obtained from patients tonsilectomized because of chronic tonsil hyperplasia.

Adolescent↗
PubMed1993

Development of B cells secreting endogenous or transgene-encoded immunoglobulins in H-chain transgenic mice.

The development of splenic B cells secreting transgene-encoded or endogenous immunoglobulin (Ig) was analysed in the mu heavy (H-)chain transgenic mouse line M54. The results show that cells secreting endogenous Ig are not detectable during the perinatal period, even after lipopolysaccharide stimulation in vitro. At this time, transgene-secreting cells are readily detectable and keep increasing with age of the animals. After a few weeks of age cells secreting endogenous Ig appear in the spleen and keep increasing with age, reaching numbers comparable to non-transgenic littermates by 5 weeks of age. Thereafter, the proportion of transgene-secreting B cells decreases. We conclude that the preferential expression of endogenous Igs by secreting B cells in the adult does not result from peculiar genetic features of those cells, but from age-dependent cellular selection operating on all B cells.

Age Factors↗
PubMed1993

Familial hemophagocytic lymphohistiocytosis and viral infections.

A retrospective study was performed in 32 children with hemophagocytic lymphohistiocytosis, 16 of whom had affected siblings. Altogether 22 of these children, of whom the majority (13/22) were familial cases, had clinical or laboratory signs of infection. Laboratory analysis demonstrated Epstein-Barr virus in five children, cytomegalovirus in three and human parvovirus in two. Two siblings with onset of familial hemophagocytic lymphohistiocytosis within one month of each other, both of whom demonstrated serological indications of a recent human parvoviral infection at onset, are described. It is concluded that a viral infection cannot serve as the sole criterion for distinguishing a virus-associated hemophagocytic syndrome as an entity separate from familial hemophagocytic lymphohistiocytosis. Instead, it is suggested that viral infections may elicit a bout of the familial hemophagocytic lymphohistiocytosis disorder in genetically predisposed individuals.

Child, Preschool↗
PubMed1993

Selective cytokine production by epithelial cells following exposure to Escherichia coli.

This study compared the repertoire of cytokines produced by epithelial cell lines and human peripheral blood monocytes in response to Escherichia coli. The A-498 and J82 urinary tract epithelial cell lines and human peripheral blood monocytes were exposed to E. coli Hu734. The cytokine content of single cells was detected by indirect immunofluorescence using monoclonal antibodies to interleukin-1 alpha (IL-1 alpha), IL-1 beta, tumor necrosis factor alpha (TNF-alpha), TNF-beta, IL-6, IL-8, and granulocyte macrophage-colony-stimulating factor, and the number of positive cells was used to quantitate the response. The J82 bladder cell line stained positive for IL-6, IL-8, and IL-1 alpha. The IL-8 and IL-6 response peaked at 2 h, while the number of IL-1 alpha-positive cells reached a peak 6 h after E. coli stimulation. The A-498 kidney cell line stained for IL-8 with a peak at 2 h and IL-6 with a peak at 6 h after E. coli stimulation. Peripheral blood monocytes stained for the cytokines IL-1 alpha, IL-1 beta, IL-8, IL-6, and TNF-alpha but not for TNF-beta and granulocyte macrophage-colony-stimulating factor after stimulation with E. coli. The results demonstrated that bacteria activated a cytokine response in the epithelial cell lines and monocytes. The epithelial cell lines had a more limited cytokine response profile than circulating monocytes, which may serve to limit the consequences of microbial exposure at the mucosal surface and help maintain the integrity of other tissue compartments.

Adult↗
PubMed1993

Vibrotactile support: initial effects on visual speech perception.

The study investigated the initial effects of the implementation of vibrotactile support on the individual's speech perception ability. Thirty-two subjects participated in the study; 16 with an acquired deafness and 16 with normal hearing. At a general level, the results indicated no immediate and direct improvement as a function of the implementation across all speech perception tests. However, when the subjects were divided into Skilled and Less Skilled groups, based on their performance in the visual condition of each test, it was found that the performance of the Skilled subjects deteriorated while that of the Less Skilled subjects improved when tactile information was provided in two conditions (word-discrimination and word-decoding conditions). It was concluded that tactile information interferes with Skilled subjects' automaticity of these functions. Furthermore, intercorrelations between discrimination and decoding tasks suggest that there are similarities between visually and tactilely supported speechreading in how they relate to sentence-based speechreading. Clinical implications of the results were discussed.

Adult↗