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Biomedical subjects

A Ljungdahl

Publications and source records attributed to A Ljungdahl.

At least 19 recordsLinked to original sources

Effect of CYP2C19 polymorphism on serum levels of vitamin B12 in patients on long-term omeprazole treatment.

BACKGROUND: The S-mephenytoin hydroxylase is a polymorphic cytochrome P450 (CYP) enzyme, identified as CYP2C19, which catalyses the metabolism of omeprazole and some other drugs. AIM: To determine whether long-term treatment with omeprazole affects serum vitamin B12 levels, and if so to what extent it depends on CYP2C19 activity. METHODS: Serum vitamin B12 levels (pmol/L) were assessed in 179 patients. Genotyping for wild-type (wt) and mutated (mut) CYP2C19 alleles was performed by allele-specific PCR amplification. RESULTS: One-hundred and eleven of the patients received one dose of 20 mg omeprazole. No difference in B12 levels were found between heterozygous (wt/mut) (n = 23) and homozygous (wt/wt) (n = 85) patients (mean +/- s.d., 350 +/- 82 vs. 315 +/- 87 pmol/L, respectively). Three patients were mut/mut, with serum vitamin B12 levels of 303 +/- 50 pmol/L. In the 68 patients on long-term (>1 year) therapy with 20 mg omeprazole daily, serum vitamin B12 levels were lower in the heterozygous (wt/mut) (n = 19) compared to homozygous wt/wt (n = 49) (246 +/- 71 vs. 305 +/- 98 pmol/L, P = 0. 01, respectively). In one patient (mut/mut) who was studied both after a single dose and after long-term (15 months) treatment with omeprazole, serum vitamin B12 decreased from 360 to 178 pmol/L. In the wt/mut, but not in the wt/wt group, serum vitamin B12 levels were significantly lower in patients on long-term therapy compared with those receiving one dose (246 +/- 71 vs. 350 +/- 82 pmol/L, P < 0.0001, respectively). CONCLUSIONS: CYP2C19 polymorphism significantly affected serum vitamin B12 levels in patients on long-term therapy with omeprazole. In the future, genotyping of CYP2C19 may be useful for patients in need of long-term treatment with omeprazole or other proton pump inhibitors.

Anti-Ulcer Agents↗

L-dopa pharmacokinetics studied with microdialysis in patients with Parkinson's disease and a history of malignant melanoma.

OBJECTIVES: The pharmacokinetics of free L-dopa in blood and tissue of five parkinsonian patients with malignant melanoma was studied with microdialysis. In one case the effect of L-dopa treatment on 5-S-cysteinyldopa and the melanoma was studied. Gastric emptying and its effects on free L-dopa in blood were also investigated in one of the patients. METHODS: Five patients were given 100 mg L-dopa with 25 mg benserazide. Blood and dialysates from the circulation and fatty tissue were collected for analysis. [13C]-Octanoic breath test was used for analyzing gastric half-emptying time. RESULTS: Four of the patients had similar pharmacokinetic patterns for L-dopa and a significant (P < 0.05) increase of serum 5-S-cysteinyldopa occurring 30 min after L-dopa intake. Delayed L-dopa peaks and slow gastric half-emptying time were found in 1 patient. A dose-dependent increase of 5-S-cysteinyldopa occurred but no melanoma metastases were seen during long-term L-dopa therapy. CONCLUSION: L-dopa therapy increases 5-S-cysteinyldopa levels but does not seem to cause progress of melanomas. Gastric emptying impacts L-dopa pharmacokinetics.

Aged↗

In situ hybridization analysis of synovial and systemic cytokine messenger RNA expression in superantigen-mediated Staphylococcus aureus arthritis.

OBJECTIVE: To investigate patterns of synovial and systemic cytokine messenger RNA (mRNA) expression in mice with superantigen-mediated Staphylococcus aureus arthritis. METHODS: Mice were inoculated intravenously with 1 x 10(7) colony-forming units of toxic shock syndrome toxin-1-producing S aureus LS-1. Synovial tissues and spleens were obtained at varying time intervals after bacterial inoculation, and examined for mRNA expression of interleukin-1beta (IL-1beta), IL-4, IL-10, IL-12, tumor necrosis factor alpha (TNFalpha), TNFbeta, interferon-gamma (IFN-gamma), transforming growth factor beta, and perforin, by an in situ hybridization technique. RESULTS: In situ hybridization revealed early synovial up-regulation of TNFalpha and IL-1 beta mRNA expression. Peak frequencies of these proinflammatory cytokines were observed at the second and third week of the infection. Expression of T cell-derived cytokine mRNAs was detected later, and in a relatively low frequency. Notably, induction and peak numbers of Th2 cytokine (IL-4 and IL-10) mRNA expression preceded Th1 cytokine (IFNgamma and TNFbeta) mRNAs. In comparison with synovial tissues, peak spleen cytokine mRNA expression of IL-1beta, TNFalpha, TNFbeta, IL-12, and IFNgamma occurred earlier, but displayed a clearly lower magnitude of expression. CONCLUSION: These findings demonstrate synovial and systemic up-regulation of cytokine mRNA expression during S aureus arthritis, indicating that both monocyte/macrophage and T cell-derived products are involved in the pathogenesis of this disease.

Animals↗

Dissociation between cytokine mRNA expression and protein production in shigellosis.

In our study, infection with Shigella dysenteriae type 1 (n = 16) or Shigella flexneri in adults (n = 5) was associated with a gradual accumulation of mRNA for interleukin (IL)-1 beta, tumor necrosis factor (TNF)-alpha, IL-6, transforming growth factor-beta, IL-10, IL-4, TNF-beta, interferon (IFN)-gamma and perforin in the rectal biopsy samples during the convalescent stage of the disease demonstrated by in situ hybridization. In contrast, immunohistochemical staining in rectal tissues of cytokine protein-producing cells at the single-cell level exhibited a steady-state expression during 2-36 days after the onset of the disease. The frequency of cytokine mRNA-expressing cells varied in the range of 3-100-fold higher than that of the corresponding protein-synthesizing cells. The accumulation of cytokine mRNA in vivo during shigellosis represented a long-lasting phenomenon throughout the disease course, and may be linked to its immunopathogenesis. The results also indicate that assessment of both protein and mRNA in vivo may provide complementary information. Stimulation in vitro of peripheral blood mononuclear cells from normal healthy donors with Shigella-derived lipopolysaccharide or shiga toxin was carried out to elucidate the role of Shigella antigens in the regulation of translation of cytokine-specific mRNA. The incidence of cytokine (IFN-gamma, IL-6 and TNF-alpha) mRNA- and cytokine protein-expressing cells was very similar and congruent after both these Shigella-derived stimuli. We could, thus, not find evidence for shiga toxin-induced down-regulation of cytokine mRNA translation as the explanation for the observed discrepancy between cytokine mRNA and protein levels in the tissue biopsies.

Acute Disease↗

Memantine abrogates neurological deficits, but not CNS inflammation, in Lewis rat experimental autoimmune encephalomyelitis.

Memantine, a clinically employed drug with N-methyl-D-aspartate (NMDA) receptor antagonistic effects, dose-dependently ameliorates neurological deficits in Lewis rat experimental autoimmune encephalomyelitis (EAE). Interestingly, this therapeutic effect was not due to dampened CNS inflammation, as assessed by immunohistochemical evaluation of spinal cord tissue. Furthermore, numbers of interferon gamma (IFN gamma) mRNA expressing cells were not decreased, as assessed by in situ hybridization. Systemic immunity in terms of numbers of IFN gamma secreting cells in response to immunodominant myelin basic protein (MBP) peptides ex vivo was not reduced, and non-toxic doses of memantine did not affect lymphocyte proliferation or IFN gamma secretion in vitro. Considering these findings, we hypothesize that effector mechanisms responsible for reversible neurological deficits in EAE may involve NMDA receptors, and this highlights neurons as targets during autoimmune neuroinflammation.

Animals↗

Increased interleukin-6 mRNA expression in blood and cerebrospinal fluid mononuclear cells in multiple sclerosis.

The increased intrathecal production of immunoglobulins within the cerebrospinal fluid (CSF) compartment commonly observed in multiple sclerosis (MS) implicates participation of B cell activating factors. One effect of the cytokine interleukin (IL)-6 is induction of immunoglobulin production by activated B cells. Employing in situ hybridization (ISH) with synthetic oligonucleotide probes, we measured numbers of IL-6 mRNA-expressing mononuclear cells (MNC) in blood and CSF from patients with MS, aseptic meningo-encephalitis (AM), and in blood from patients with other neurological diseases (OND) and healthy subjects. Numbers of IL-6 mRNA-expressing MNC were elevated in blood (mean frequency 1 per 33,000 MNC) and even further enriched in the CSF (1 per 10,000 MNC) of MS patients, and to a similar extent in AM patients' blood. Cultivation in the presence of myelin basic protein and proteolipid protein revealed strong augmentation of IL-6 mRNA-positive cells in MS but not in OND. The results suggest that IL-6 is one of several cytokines which are upregulated in MS, in particular locally in the CSF. A role of IL-6 in MS, whether disease- promoting or protective, remains unclear.

Adult↗

Interleukin-10 mRNA expression in B-cell chronic lymphocytic leukaemia inversely correlates with progression of disease.

Interleukin-10 (IL-10) has been shown in vitro to inhibit survival and spontaneous DNA synthesis in B-cell chronic lymphocytic leukaemia (B-CELL) cells by induction of programmed cell death. We have analysed the presence of mRNA transcripts for IL-10 in purified B-CLL cells from 35 patients by RT-PCR. Transcripts for IL-10 were detected in 11/20 patients with non-progressive disease. In cell preparations from patients with progressive B-CLL IL-10 mRNA were detected in only 2/15 samples (P < or = 0.01). The Epstein-Barr virus status of the cells did not account for the difference in IL-10 mRNA expression observed between the two groups of patients. Thus, IL-10 mRNA expression in leukaemic cells from patients with B-CLL was strongly associated with non-progressive disease. This finding may support other observations suggesting that IL-10 might be a candidate for immune therapy of progressive B-CLL.

Aged↗

Induction of interferon-gamma, transforming growth factor-beta, and interleukin-4 in mouse strains with different susceptibilities to Trypanosoma brucei brucei.

A Trypanosoma brucei brucei-derived lymphocyte triggering factor (TLTF) induced CD8+ T cells to produce IFN-gamma, which in turn stimulates parasite growth. This parasite-host interaction was studied in mouse strains that are either relatively susceptible (C3H/He) or resistant (C57Bl/6J) to infection, as well as in athymic nude mice. In all mouse strains, T. b. brucei infection caused a strong induction of IFN-gamma production by spleen mononuclear cells (MNC). In vivo blocking of IFN-gamma by intraperitoneal injection of mouse monoclonal anti-IFN-gamma antibody suppressed parasite growth and increased survival of both C3H/H3 and C57Bl/6J animals, suggesting that, irrespective of strain-related disease susceptibility, IFN-gamma is a growth-promoting stimulus for T. b. brucei. Spleen MNC from noninfected mice of all strains were in vitro like-wise strongly induced to IFN-gamma production when exposed to TLTF. This suggests that CD8+ expressing T cell receptor (TCR) alpha/beta, gamma/delta-bearing T cells and NK cells may all be triggered to IFN-gamma production by TLTF. In all mouse strains, TLTF also caused an increase in the number of cells expressing mRNA for TGF-beta in vitro. However, significant triggering to IL-4 mRNA expression only occurred in the relatively disease-resistant C57Bl/6J strain. As IL-4 is required for the synthesis and class switches of immunoglobulins, which are essential host immune defenses against T. b. brucei, the degree of resistance may be related to inherent strain ability to produce IL-4 in response to TLTF.

Animals↗

Local entrapment of interferon gamma in the recovery from Shigella dysenteriae type 1 infection.

In healthy controls (n = 8) living in shigella endemic areas, accumulation of interferon gamma (IFN gamma) in the epithelial lining was seen in the rectal tissues. At the single cell level, however, few or no IFN gamma protein producing cells or mRNA expressing cells were detected at that site indicating the involvement of the whole large intestine in the production of IFN gamma in controls. Persistent numbers of IFN gamma producing cells were detected in the rectum of patients with Shigella dysenteriae type 1 infection (n = 8) throughout the course of disease with a tendency to increase in the convalescent stage. A significantly increased extra cellular deposition of secreted IFN gamma in tissue was seen in convalescence when compared with the acute stage (p < 0.05). In addition, enzyme immunoassay showed increased stool concentration of IFN gamma in patients at the convalescent stage as well as in healthy controls. In situ hybridisation confirmed the results by showing increased frequency of IFN gamma mRNA containing cells at the late stage of the disease (p < 0.05). Extensive message for IFN gamma was evident in cells in the lamina propria with no detectable transcripts in the surface epithelium. A colocalisation of IFN gamma with the IFN gamma receptor expression, predominantly found in the epithelial lining was detected by immunohistochemistry. Semiquantitative evaluation by computerised image analysis showed a gradual increased expression of IFN gamma and its corresponding receptor in the convalescent stage of shigellosis. This suggested progressive entrapment and binding of IFN gamma to its specific receptor at the local site. The enhanced surface expression of IFN gamma receptor evident at the convalescent stage of shigellosis was comparable to the constitutive level of expression in the healthy subjects. Thus, immunity to shigellosis correlated to up-regulation of IFN gamma production and expression of IFN gamma receptor.

Acute Disease↗

Increased mRNA expression of IL-6, IL-10, TNF-alpha, and perforin in blood mononuclear cells in human HIV infection.

Evidence has been presented for the involvement of various cytokines, including interleukin (IL)-6, IL-10, and tumor necrosis factor (TNF)-alpha, in the pathogenesis of human immunodeficiency virus (HIV) infection. Since measured plasma levels may poorly reflect in vivo production of cytokines, we adopted in situ hybridization with cDNA oligonucleotide probes to enumerate blood mononuclear cells (MNCs) expressing mRNA for IL-6, IL-10, TNF-alpha, and perforin. The HIV-infected patients had elevated levels of MNCs expressing mRNA for all four cytokines compared to healthy controls. Numbers of IL-6 mRNA-expressing cells were higher in patients with clinical AIDS than in asymptomatic seropositive patients, and correlated inversely with CD4+ cell counts in blood, reflecting the involvement of IL-6 in later stages of HIV infection. The described approach could be an alternative way to study cytokines in HIV infection.

Acquired Immunodeficiency Syndrome↗

Interferon gamma, interleukin 4 and transforming growth factor beta in experimental autoimmune encephalomyelitis in Lewis rats: dynamics of cellular mRNA expression in the central nervous system and lymphoid cells.

The potential role of certain important immunoregulatory and effector cytokines in autoimmune neuroinflammation have been studied. We have examined the expression of mRNA, with in situ hybridization, of interferon gamma (IFN-gamma), interleukin 4 (IL-4) and transforming growth factor beta (TGF-beta) both in sections of spinal cords and the antigen-induced expression of these cytokines by lymphoid cells after stimulation with a dominant encephalitogenic peptide of MBP (MBP 63-88) during the course of actively induced experimental autoimmune encephalomyelitis (EAE) in Lewis rats. In spinal cords, the target organ in EAE, cells expressing mRNA for IFN-gamma, first appeared at the onset of clinical signs, i.e., day 10 postimmunization (p.i.), peaked at the height of disease (day 13 p.i.) and then gradually decreased concomitant with recovery. Very few IL-4 mRNA-expressing cells appeared in the spinal cord with no clear relation to clinical signs or histopathology. In contrast, expression of mRNA for TGF-beta did not increase until day 13 p.i., at height of the disease, shortly preceding recovery. These data are consistent with a disease upregulating role of IFN-gamma, while TGF-beta may act to limit central nervous system (CNS) inflammation. In lymphoid organs, primed MBP 63-88 reactive T cells showed an interesting time-dependent evolution of their cytokine production in vitro. Thus, early after immunization there was a conspicuous MBP 63-88-induced production of both IFN-gamma and IL-4. Such cells may act in the initiation and promotion of the disease. Later, in the recovery phase, MBP 63-88 induced lymphoid cells to TGF-beta production. Thus, an autoantigen-specific production of TGF-beta occurred during EAE and hypothetically such a mechanism may serve to downregulate aggressive autoimmunity systemically.

Amino Acid Sequence↗

Patterns of interferon-gamma mRNA expression in toxic shock syndrome toxin-1 expanded V beta 11+ T lymphocytes.

We have recently demonstrated that toxic shock syndrome toxin-1 (TSST-1), a staphylococcal exotoxin with superantigenic properties, is involved in the pathogenesis of septic arthritis. The aim of the current study was to characterize in detail the in vitro properties of TSST-1 with regard to T cell activation patterns. We demonstrate that TSST-1 preferentially expands murine V beta 11+ T lymphocytes and this expansion occurs equally well within CD4 and CD8 compartments. To analyze the functional properties of V beta 11+ T cells expanded in response to TSST-1, we have utilized a combined in situ hybridization and immunocytochemistry method. With this technique we show that TSST-1-stimulated V beta 11+ T cells are an important source of IFN gamma mRNA synthesis, suggesting that this cytokine may participate in superantigen-mediated septic arthritis.

Animals↗

Cytokine production in the central nervous system of Lewis rats with experimental autoimmune encephalomyelitis: dynamics of mRNA expression for interleukin-10, interleukin-12, cytolysin, tumor necrosis factor alpha and tumor necrosis factor beta.

The kinetics of mRNA expression in the central nervous system (CNS) for a series of putatively disease-promoting and disease-limiting cytokines during the course of experimental autoimmune encephalomyelitis (EAE) in Lewis rats were studied. Cytokine mRNA-expressing cells were detected in cryosections of spinal cords using in situ hybridization technique with synthetic oligonucleotide probes. Three stages of cytokine mRNA expression could be distinguished: (i) interleukin (IL)-12, tumor necrosis factor (TNF)-beta (= lymphotoxin-alpha) and cytolysin appeared early and before onset of clinical signs of EAE; (ii) TNF-alpha peaked at height of clinical signs of EAE; (iii) IL-10 appeared increasingly at and after clinical recovery. The early expression of IL-12 prior to the expression of interferon-gamma (IFN-gamma) mRNA shown previously is consistent with a role of IL-12 in promoting proliferation and activation of T helper 1 (Th1) type cells producing IFN-gamma. The TNF-beta mRNA expression prior to onset of clinical signs favours a role for this cytokine in disease initiation. A pathogenic effector role of TNF-alpha was suggested from these observations that TNF-alpha mRNA expression roughly paralleled the clinical signs of EAE. This may be the case also for cytolysin. IL-10-expressing cells gradually increased to high levels in the recovery phase of EAE, consistent with a function in down-regulating the CNS inflammation. From these data we conclude that there is an ordered appearance of putative disease-promoting and -limiting cytokines in the CNS during acute monophasic EAE.

Animals↗

Suppression of experimental autoimmune myasthenia gravis after CD8 depletion is associated with decreased IFN-gamma and IL-4.

CD8+ T cells can perform both Th1- and Th2-like functions by producing cytokines such as interferon-gamma (IFN-gamma) and interleukin-4 (IL-4), as well as the immune response down-regulating transforming growth factor-beta (TGF-beta), which are all involved in the development of experimental autoimmune myasthenia gravis (EAMG), a model for human MG. We have reported that depletion of CD8+ T cells results in the suppression of EAMG accompanied by the down-regulation of AChR-specific B cell responses and AChR-reactive IFN-gamma secreting Th1-like cells. To identify the involvement of IFN-gamma, IL-4 and TGF-beta in the development of EAMG after CD8+ T cell depletion, the expression of mRNA for these cytokines was studied in mononuclear cells from popliteal, inguinal and mesenteric lymph nodes, spleen and thymus by adopting in situ hybridization with complementary DNA oligonucleotide probes. Depletion of CD8+ T cells resulted in decreased levels of IFN-gamma and IL-4 mRNA expressing cells in different lymphoid organs except thymus, but no change in the numbers of TGF-beta mRNA expressing cells. The results imply that the suppression of EAMG after depletion of CD8+ T cells is caused by decreasing the effector factors but not by increasing the suppressor factor(s).

Animals↗

Protective influences on experimental autoimmune encephalomyelitis by MHC class I and class II alleles.

Experimental autoimmune encephalomyelitis (EAE) is influenced by polymorphism of the MHC. We have previously found that Lewis rats with certain MHC haplotypes are susceptible to disease induced with the myelin basic protein (MBP) peptide 63-88, whereas Lewis rats with other MHC haplotypes are resistant. Interestingly, rats with the MHC u haplotype develop an immune response to the MBP 63-88, but do not get EAE. In this study we have used intra-MHC recombinant rat strains to compare the influences of the MHC u with the a haplotype. We discovered the following: 1) The class II region of the MHC a haplotype permits EAE and a Th1 type of immune response as measured by IFN-gamma production after in vitro challenge of in vivo-primed T cells with MBP 63-88. 2) The class II region of the u haplotype is associated with a disease-protective immune response characterized by production of not only IFN-gamma, but also of IL-4 mRNA expression by the MBP 63-88-activated cells. 3) The class I region upstream of the class II region of the u haplotype is associated with a disease-protective effect and the expression of mRNA for TGF-beta after MBP 63-88-induced activation. Thus, such a TGF-beta response occurs in all strains expressing the class I Au allele. Treatment with Abs to CD8+ cells abrogates peptide-induced TGF-beta mRNA expression, and aggravates disease in strains with the class I Au allele.

Alleles↗

Organ-specific autoantigens induce transforming growth factor-beta mRNA expression in mononuclear cells in multiple sclerosis and myasthenia gravis.

Multiple sclerosis (MS) is characterized by patchy accumulations of inflammatory cells combined with demyelination. There are mononuclear cells in blood and cerebrospinal fluid of patients with MS that produce interferon-gamma and interleukin-4 in response to myelin basic protein (MBP) and proteolipid protein (PLP). Here we describe autoantigen-induced production of transforming growth factor-beta (TGF-beta). This multifunctional cytokine has inhibitory effects on the growth, differentiation, and effector functions of activated T cells. Blood and cerebrospinal fluid cells were exposed in short-term cultures to MBP and PLP and, after hybridization with complementary DNA oligonucleotide probes, they were evaluated for TGF-beta mRNA expression. Patients with MS had higher numbers of MBP- and PLP-responsive TGF-beta mRNA expressing cells in blood compared with control patients with other neurological diseases or myasthenia gravis and a five- and threefold further increment in their cerebrospinal fluid. In blood of patients with myasthenia gravis, where the acetylcholine receptor (AChR) is a target for autoaggressive immunity, there were increased levels of AChR-responsive TGF-beta mRNA expressing cells. Thymectomized myasthenia gravis patients showed higher levels of TGF-beta mRNA expressing cells compared with patients not thymectomized. Numbers of cells responding to AChR in MS and MBP in myasthenia gravis did not differ from numbers found in absence of antigen. Patients with other neurological diseases showed infrequent and low responses to MBP, PLP, and AChR. Diseases with presumed autoimmune pathogenesis are associated with organ-specific autoantigen-induced TGF-beta production, which is increased after thymectomy.

Adult↗

Increased transforming growth factor-beta, interleukin-4, and interferon-gamma in multiple sclerosis.

The inflammatory nature of multiple sclerosis (MS) implicates the participation of immunoregulatory cytokines, including the T-helper type 1 (Th1) cell-associated interferon-gamma (IFN-gamma), the Th2 cell-related interleukin-4 (IL-4), and the immune response-downregulating cytokine transforming growth factor-beta (TGF-beta), but proof for their involvement in MS has been lacking. By adopting in situ hybridization with complementary DNA oligonucleotide probes for human IFN-gamma IL-4, and TGF-beta, the expression of mRNA for these cytokines was detected in mononuclear cells (MNC) from blood and cerebrospinal fluids. Strongly elevated levels of MNC expressing all three cytokines were found in peripheral blood and at even higher frequencies in cerebrospinal fluid from untreated patients with MS and optic neuritis, i.e., a common first manifestation of MS, compared with patients with other neurological diseases and healthy subjects. In MS and optic neuritis, IL-4 mRNA expressing cells predominated, followed by TGF-beta- and IFN-gamma-positive cells. Control patients with myasthenia gravis had similarly elevated levels of IFN-gamma and TGF-beta and TGF-beta mRNA expressing blood MNC but lower numbers of IL-4-positive cells. No or slight disability of MS was associated with high levels of TGF-beta mRNA expressing cells, while MS patients with moderate or severe disability had high levels of IFN-gamma-positive cells. IFN-gamma and TGF-beta may have opposing effects in MS, and treatments inhibiting IFN-gamma and/or promoting TGF-beta might ameliorate MS.

Adult↗