Search PubMed⌕ Search

Biomedical subjects

H Link

Publications and source records attributed to H Link.

At least 253 records · Page 14Linked to original sources
PubMed1996

COBAS AMPLICOR: fully automated RNA and DNA amplification and detection system for routine diagnostic PCR.

The COBAS AMPLICOR system automates amplification and detection of target nucleic acids, making diagnostic PCR routine for a variety of infectious diseases. The system contains a single thermal cycler with two independently regulated heating/cooling blocks, an incubator, a magnetic particle washer, a pipettor, and a photometer. Amplified products are captured on oligonucleotide-coated paramagnetic microparticles and detected with use of an avidin-horseradish peroxidase (HRP) conjugate. Concentrated solutions of amplicon or HRP were pipetted without detectable carryover. Amplified DNA was detected with an intraassay CV of < 4.5%; the combined intraassay CV for amplification and detection was < 15%. No cross-reactivity was observed when three different target nucleic acids were amplified in a single reaction and detected with three target-specific capture probes. The initial COBAS AMPLICOR menu includes qualitative tests for diagnosing infections with Chlamydia trachomatis, Neisseria gonorrhoeae, Mycobacterium tuberculosis, and hepatitis C virus. All tests include an optional Internal Control to provide assurance that specimens are successfully amplified and detected.

Autoanalysis↗
PubMed1995

Combined transplantation of allogeneic bone marrow and CD34+ blood cells.

Allogeneic peripheral blood progenitor cells (PBPCs) were transplanted after immunoselection of CD34+ cells. Two patient groups were studied: group I patients received immunoselected blood CD34+ cells and unmanipulated marrow cells from the same donor. Group II patients were given immunoselected blood and bone marrow (BM) CD34+ cells. One to 6 weeks before bone marrow transplantation (BMT), PBPCs from HLA-identical and MLC- sibling donors were mobilized with granulocyte colony-stimulating factor (G-CSF) (5 micrograms/kg twice daily subcutaneously) for 5 days. Aphereses were performed at days 4 and 5 of G-CSF application. CD34+ cells were separated from the pooled PBPC concentrates by immunoadsorption onto avidin with the biotinylated anti-CD34 monoclonal antibody 12.8 and then stored in liquid nitrogen. BM was procured on the day of transplantation. Patients were conditioned with either busulfan (16 mg/kg) or total body irradiation (12 Gy) followed by cyclophosphamide (120 mg/kg). Cyclosporin A and short methotrexate were used for graft-versus-host disease (GVHD) prophylaxis. After transplantation, all patients received 5 micrograms G-CSF/kg/d from day 1 until greater than 500 neutrophils/microL were reached and 150 U erythropoietin/kg/d from day 7 until erythrocyte transfusion independence for 7 days. Group I consisted of patients with acute myeloid leukemia (AML) (n = 2), chronic myeloid leukemia (CML) (n = 2), and T-gamma-lymphoproliferative syndrome and BM aplasia (n = 1). The patients received a mean of 3.3 x 10(6) CD34+ and 3.7 x 10(5) CD3+ cells/kg body weight of PBPC origin and 4.5 x 10(6) CD34+ and 172 x 10(5) cells/kg body weight of BM origin. Group II consisted of five patients (two AML, two CML, one non-Hodgkin's lymphoma). They received a mean of 3.3 x 10(6) CD34+ and 3.2 x 10(5) CD3+ cells/kg from PBPC and 1.4 x 10(6) CD34+ and 0.6 x 10(5) CD3+ cells from BM. A matched historical control group (n = 12) transplanted with a mean of 5.2 x 10(6) CD34+ and 156 x 10(5) CD3+ cells/kg from BM alone was assembled for comparison. In group I, the median time to neutrophil recovery to > 100, > 500, and > 1,000/microL was 12, 15, and 17 days, respectively. Patients from group II reached these neutrophil levels at days 13, 15 and 17 post BMT. Neutrophil recovery in the control patient group occurred at days 17, 18, and 20 respectively. Group I patients were given platelet transfusions within 18 days and red blood cells within 10 days, whereas for group II patients, these time points were 26 and 17 days, respectively. These same transfusions could be ceased within 38 and 24 days, respectively, in control patients. The addition of about 2% more peripheral blood CD3+ cells (group I patients) did not result in higher grades of acute GVHD (median grade II) as compared with the controls (median grade II). Four of five group II patients showed no signs of acute GVHD. These data suggest that the addition of immunoselected allogeneic CD34+ progenitor cells to BM cells may accelerate hematopoietic recovery.

Adult↗
PubMed1995

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↗
PubMed1995

Depletion of CD8+ T cells suppresses the development of experimental autoimmune myasthenia gravis in Lewis rats.

To understand the role of CD8+ T cells in experimental autoimmune myasthenia gravis (EAMG), CD8+ T cells were depleted by injecting a monoclonal anti-rat CD8 antibody (OX8) into Lewis rats immunized with Torpedo acetylcholine receptor (AChR) in complete Freund's adjuvant (CFA). CD8-depleted EAMG rats showed strikingly less muscle weakness and lower anti-AChR IgG antibody levels compared to Hy2-15-injected control EAMG rats. Moreover, the numbers of AChR-specific IgG antibody-secreting cells, AChR-reactive interferon-gamma-secreting T helper type 1-like cells and lymphocyte proliferation to AChR were lower in the CD8-depleted group than in control EAMG rats. These differences were significant among mononuclear cells from inguinal and popliteal lymph nodes, mesenteric lymph nodes and spleen, but not from thymus when examined 3, 5 and 7 weeks post-immunization. We suggest that CD8+ T cells are involved in the induction and persistance of EAMG by directly or indirectly affecting AChR-reactive T cells and anti-AChR IgG antibody-secreting cells.

Animals↗
PubMed1995

Aerosol amphotericin B inhalations for prevention of invasive pulmonary aspergillosis in neutropenic cancer patients.

To determine the value of aerosol amphotericin B inhalations for prevention of invasive pulmonary aspergillosis (IPA), we initiated a prospective randomized multicenter trial. The scheduled intent-to-treat interim analysis included 115 patients (30%) with prolonged neutropenia after chemotherapy for acute myeloid leukemia, acute lymphoblastic leukemia/high-grade non-Hodgkin's lymphoma, or solid tumors undergoing autologous stem cell transplantation. Sixty-five patients had been randomized to receive prophylactic aerosol amphotericin B inhalations at a dose of 10 mg twice daily (group A); for the remaining 50 patients no aerosol amphotericin B prophylaxis was used (group B). No serious side effects from amphotericin B inhalations occurred, but coughing (54%), bad taste (51%), and nausea (37%) caused early cessation of aerosol amphotericin B prophylaxis in 23% (15/65) of courses. In group A, the incidence of proven, probably, or possible IPA was 5% (3/65) as compared with 12% (6/50) in group B (p > 0.05). Microbiologically documented bacterial pneumonias were observed in 5/65 (8%) patients in group A and in 1/50 (2%) patients in group B (p > 0.05). Thus, no reduction in incidence of IPA from use of prophylactic aerosol amphotericin B inhalations was found in this interim analysis. As there were no serious side effects from aerosol amphotericin B prophylaxis, accrual in the study will continue for a total of 380 patients.

Administration, Inhalation↗
PubMed1995

High-dose cytosine arabinoside and daunorubicin postremission therapy in adults with de novo acute myeloid leukemia. Long-term follow-up of a prospective multicenter trial.

A total of 149 consecutive de novo AML patients aged 50 years or less (median age = 37 years) were enrolled in this prospective multicenter trial initiated in May 1985. All patients received the same induction and early consolidation therapy with daunorubicin (DNR), cytosine arabinoside (Ara-C), and etoposide (DAV). High-dose Ara-C/DNR therapy included Ara-C at 3 g/m2, in 12 doses (HD-Ara-C/DNR I) and eight doses (HD-Ara-C/DNR II), followed by DNR 30 mg/m2 for 3 days. A complete remission (CR) was achieved in 104 (70%) patients; 61 complete responders received at least one cycle with HD-Ara-C/DNR. If those patients who were transplanted in first CR (n = 26), were not considered, the median relapse-free-survival (MRFS) of the remaining 78 patients was 15 months, with a probability of relapse-free survival (RFS) at 116 months of 30% (95% CI, 20-40%) after a median follow-up of 95 months. The MRFS of the HD-Ara-C/DNR consolidated patients was 25 months, with a probability of RFS at 116 months of 37% (95% CI, 24-50%). If all patients who were transplanted (n = 44) were not considered, the median survival time (MST) was 18 months with a probability of being alive at 118 months of 24% (95% CI, 16-33%). MST of the HD-Ara-C/DNR consolidated patients was 58 months with a survival probability of 46% (95% CI, 31-60%) at 118 months. Prognostic factor analysis did not reveal any significant influence of age, sex, FAB subtype, white blood cell count, hemoglobin level, thrombocyte count, LDH, or response to the first induction course on RFS of the HD-Ara-C/DNR consolidated patients. In summary, HD-Ara-C/DNR consolidation can improve the long-term outcome of a subgroup of de novo AML patients. Further improvement of the outcome seems to depend on the identification of patients with an inferior outcome under that strategy who might benefit from alternative treatment strategies.

Adolescent↗
PubMed1995

B cell responses to acetylcholine receptor in rats orally tolerized against experimental autoimmune myasthenia gravis.

Oral administration of acetylcholine receptor (AChR) to Lewis rats prior to myasthenogenic immunization with AChR and complete Freund's adjuvant (CFA) results in the prevention of experimental autoimmune myasthenia gravis (EAMG), and decreased serum levels of anti-AChR antibodies. Using an ELISPOT assay, we have now determined numbers of cells in the popliteal, inguinal and mesenteric lymph nodes, spleen and thymus secreting anti-AChR IgG antibodies. Except for mesenteric lymph nodes, a marked diminution of such cells was detected in these lymphoid organs in rats orally tolerized with AChR compared to buffer-fed or vehicle-fed control rats with EAMG. Of note is that, after AChR feeding, the B cell response to AChR in thymus was diminished to the same low level as in CFA-injected, buffer-fed control rats. The relative affinity of serum anti-AChR IgG antibodies measured by KSCN-ELISA was lower in the orally tolerized rats compared to buffer-fed or vehicle-fed rats. The observations showed that oral administration of AChR, besides preventing clinical EAMG, also counteracts the development of AChR-specific B cells, especially those with high affinity antibody production, in most lymphoid organs.

Administration, Oral↗
PubMed1995

Analysis of CD27 surface expression on T cell subsets in MS patients and control individuals.

Within the peripheral blood, CD4+CD27- T cells only reside within the CD45RA- (memory or primed) T cell subset. Cells with this phenotype have characteristics of specialized effector T cells according to their cytokine secretion profiles and the expression of tissue-specific adhesion molecules. This subset was previously found to be increased in certain diseases that are associated with immune activation. Therefore we analyzed CD27 expression of peripheral blood and CSF T cells in MS patients. Within the CD4+ T cell subset no differences were seen between MS patients and controls in proportions of CD45RA-CD27- cells. However, when the CD3+ T cell compartment was analyzed, CD27- cells were also found within the CD45RA+ subset. These cells, most likely CD8+, are significantly reduced in PBL and CSF of MS patients as compared with OND patients. In MS and OND groups the level of CD27- cells in peripheral blood correlated significantly with that in CSF, indicating a balanced migration of CD27- cells between the two compartments. In OIND patients, however, this equilibrium was lost. The correlation of the level of CD27+ cells with the amount of intrathecally produced IgG in MS patients may suggest that CD27+ cells are responsible for B cell help in this disease.

Adult↗
PubMed1995

Transforming growth factor-beta 1 suppresses autoantigen-induced expression of pro-inflammatory cytokines but not of interleukin-10 in multiple sclerosis and myasthenia gravis.

Multiple sclerosis (MS) is associated with high levels of circulating T lymphocytes that respond to the myelin antigens myelin basic protein (MBP) and proteolipid protein (PLP) by producing various cytokines including interferon-gamma (IFN-gamma) that makes MS worse and transforming growth factor-beta (TGF-beta), an endogenously produced immunosuppressant that might act beneficially. To further define the role of TGF-beta in MS, we examined the effects of recombinant TGF-beta 1 (rTGF-beta 1) on autoantigen-mediated regulation of cytokines in MS and myasthenia gravis (MG). Blood mononuclear cells (MNC) were cultivated with or without rTGF-beta 1, and with or without autoantigen or the recall antigen PPD. MNC expressing cytokine mRNA were detected after in situ hybridization with radiolabeled cDNA oligonucleotide probes. Femtogram concentrations of rTGF-beta 1 suppressed MBP-, PLP- and PPD-induced upregulation of IFN-gamma, IL-4, IL-6, tumor necrosis factor-alpha (TNF-alpha), TNF-beta and perforin in MS, and acetylcholine receptor (AChR)-induced augmentation of these pro-inflammatory cytokines in MG, but had no effects on autoantigen- or PPD-induced expression of IL-10 or TGF-beta itself. rTGF-beta 1 also suppressed numbers of myelin antigen-reactive IFN-gamma- and IL-4-secreting cells in MS and AChR-reactive IFN-gamma and IL-4 secreting cells in MG. The selective suppressive effects of TGF-beta 1 on autoantigen-induced upregulation of pro-inflammatory cytokines makes TGF-beta 1 attractive as a treatment alternative in MS and MG.

Adult↗
PubMed1995

Suppression of experimental autoimmune myasthenia gravis by nasal administration of acetylcholine receptor.

Experimental autoimmune myasthenia gravis (EAMG) is a well established animal model, which can be induced in various animal species and strains with acetylcholine receptor (AChR) and represents an experimental counterpart of human myasthenia gravis (MG). Current immunotherapies of both EAMG and MG are non-specific and limited by their toxicity. Tolerance to EAMG has been achieved by oral administration of milligram quantities of Torpedo AChR. In the present report we demonstrate that nasal administration of microgram doses of Torpedo AChR to female Lewis rats prior to immunization with Torpedo AChR and complete Freund's adjuvant resulted in the prevention of subsequently induced EAMG, the suppression of serum anti-AChR antibody levels, the decrease of delayed-type hypersensitivity responses to AChR, as well as the suppression of AChR-specific immunoglobulin G-secreting cells, AChR-reactive interferon-gamma-secreting cells and T cell proliferation in peripheral lymphoid organs, particularly in popliteal and inguinal lymph nodes regional to immunization. We conclude that clinical signs of EAMG can be efficiently prevented by nasal administration of AChR in parallel with the downregulation of both B and T cell responses specific to AChR.

Administration, Intranasal↗
PubMed1995

Suppression of experimental autoimmune myasthenia gravis and experimental allergic encephalomyelitis by oral administration of acetylcholine receptor and myelin basic protein: double tolerance.

Oral administration of acetylcholine receptor (AChR) or myelin basic protein (MBP) to Lewis rat prior to immunization with AChr or MBP and complete Freund's adjuvant (CFA) has previously been shown to prevent or delay the onset of experimental autoimmune myasthenia gravis (EAMG) or experimental allergic encephalomyelitis (EAE), which represent animal models of myasthenia gravis and multiple sclerosis, respectively. Here we show that Lewis rats immunized with AChr+MBP+CFA developed both signs of muscular weakness seen in EAMG and paresis characteristic for EAE. This disease was associated with high levels of anti-AChR and anti-MBP antibody secreting cells and of AChR- and MBP-reactive INF-gamma secreting Th1-like cells in lymph nodes. The diseased rats also showed upregulation of AChR- and MBP-induced mRNA expression of IFN-gamma in lymph node cells. Oral tolerization with AChR and MBP in combination prior to immunization with AChR+MBP+CFA alleviated clinical disease as well as AChR- and MBP-specific B cell node cells. The results implicate that oral tolerization simultaneously to more than one autoimmune disease-related autoantigen is feasible, and that suppression of autoantigen-induced IFN-gamma and augmentation of TGF-beta are pivotal in tolerance induction.

Administration, Oral↗
PubMed1995

Granulocyte growth factors: achieving a consensus.

A consensus meeting held under the auspices of the European School of Oncology concluded that the use of granulocyte growth factors is definitely indicated, or acceptable given existing evidence, in the following circumstances: to alleviate congenital neutropenia; in the mobilisation of peripheral blood progenitor cells for autotransfusion; to encourage engraftment following bone marrow transplantation and in cases of failed engraftment; to support continuation of ganciclovir anti-CMV therapy in certain patients with AIDS, where the switch to foscarnet is contraindicated or where toxicity to foscarnet develops. It was also agreed that there is an overwhelming need for carefully controlled clinical trials in a wide range of indications in which growth factor use may improve outcome. In the majority of tumours, the possible benefit of dose optimisation and intensification, and therefore the role of growth factors in support of such measures has still to be defined. Extramedullary toxicities may in these instances become dose limiting.

AIDS-Related Opportunistic Infections↗
PubMed1995

High numbers of autoantigen-reactive mononuclear cells expressing interferon-gamma (IFN-gamma), IL-4 and transforming growth factor-beta (TGF-beta) are present in cord blood.

Umbilical cord blood of neonates and peripheral blood of healthy adults were analysed by in situ hybridization for numbers of mononuclear cells (MNC) expressing the cytokines IFN-gamma, TGF-beta and IL-4 mRNA without culture and after culture in the presence of acetylcholine receptor (AChR), myelin basic protein (MBP) and peripheral myelin protein P2. These antigens were chosen since they represent autoantigens in putatively immune-mediated neurological diseases. The numbers of cells expressing cytokine mRNA after 72 h culture in the presence of AChR, MBP and P2 were higher in cord blood than in peripheral blood of healthy adults. IFN-gamma, TGF-beta and IL-4 were always elevated in parallel. In cord blood there was a pronounced reactivity to several of the tested antigens, while such broad reactivity was not found in peripheral blood of healthy adults. No differences in cytokine mRNA expression were found between cord blood and peripheral blood of adults when cells were analysed without culture. The results show a capacity of cord blood cells to react to several autoantigens by the up-regulation of cytokine mRNA expression.

Adult↗
PubMed1995

Increased mRNA expression of IL-10 in mononuclear cells in multiple sclerosis and optic neuritis.

The inflammatory nature of multiple sclerosis (MS) implicates the participation of immunoregulatory cytokines, including the Th2 related IL-10. We describe the use of in situ hybridization with cDNA oligonucleotide probes to detect and enumerate mononuclear cells (MNC) expressing mRNA for IL-10, which is known to down-regulate Th1 cell related cytokines such as interferon-gamma. Expression of IL-10 was studied in blood MNC of MS and blood and cerebrospinal fluid (CSF) MNC of optic neuritis (ON) patients without culture and after culture in the presence of myelin basic protein (MBP), the control antigen acetylcholine receptor (AChR), and without antigen. Numbers of IL-10 mRNA expressing MNC were elevated in the MS patients' blood both when enumerated without culture and after culture with MBP. Control patients with myasthenia gravis had elevated numbers of AChR-reactive IL-10 mRNA expressing cells, while numbers of MBP-reactive IL-10 positive cells did not differ from numbers registered in cells without antigen. Patients with ON, in many instances representing early MS, had IL-10 positive blood MNC that were elevated to the same extent as in clinically definite MS, and further increased in the CSF. ON patients examined within 1 month after onset had lower numbers of MBP induced IL-10 mRNA expressing blood MNC compared with patients examined later suggesting that IL-10 is related to the degree of inflammation and outcome in ON.

Adolescent↗
PubMed1995

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↗
PubMed1995

Lyme neuroborreliosis: evidence for persistent up-regulation of Borrelia burgdorferi-reactive cells secreting interferon-gamma.

The T-cell response to the aetiologic pathogen Borrelia (B.) burgdorferi in patients with Lyme neuroborreliosis (LN) and in control patients with other neurological diseases was examined by enumerating B. burgdorferi-reactive T cells secreting interferon-gamma (IFN-gamma) with an ELIspot assay. LN patients had elevated numbers of B. burgdorferi-reactive IFN-gamma secreting cells in blood and approximately 20-fold enriched in the cerebrospinal fluid (CSF). A positive correlation existed in CSF between B. burgdorferi-reactive IFN-gamma secreting cells and B cells secreting anti-B. burgdorferi IgG antibodies. The up-regulation of antigen-specific IFN-gamma secreting cells persisted in peripheral blood up to at least 9 months and in the CSF for at least 4 months after termination of treatment with antibiotics, when the patients were mostly free from clinical signs and symptoms due to LN. How IFN-gamma interplays with other cytokines and influences the pathogenesis of LN remains to be studied.

Adult↗
PubMed1995

Cytokine mRNA profiles in mononuclear cells in acute aseptic meningoencephalitis.

Cytokines are important modulators of inflammation and immune responses. Using in situ hybridization with radiolabelled cDNA oligonucleotide probes, we studied the expression of mRNA encoding the cytokines gamma interferon (IFN-gamma), interleukin 4 (IL-4), IL-6, IL-10, transforming growth factor beta (TGF-beta), tumor necrosis factor alpha (TNF-alpha), lymphotoxin, and perforin in mononuclear cells (MNC) from blood and cerebrospinal fluid (CSF) of patients with acute aseptic meningoencephalitis (AM) and from blood of healthy controls. Patients in the acute phase of AM had elevated numbers of IFN-gamma mRNA-expressing cells in the blood compared with that of controls and higher numbers of IFN-gamma mRNA-expressing cells in their CSF compared with that of convalescent-phase patients, which is in accordance with the antiviral effects of this cytokine. Upregulation of IL-4, IL-6, and IL-10 was found in convalescent-phase patients, which is consistent with the longstanding B-cell response found in AM. TGF-beta and perforin were upregulated in both stages of AM, while the numbers of blood and CSF MNC expressing cytokine mRNA of the TNF family (TNF-alpha and lymphotoxin) did not differ between patients with AM and controls. An even higher elevation in CSF was noticed for MNC expressing most of the cytokines, particularly IL-4 and TGF-beta, reflecting the autonomy of the immune response in the CSF. The definition of cytokine profiles in AM, a self-limiting and benign disease, provides a foundation for future comparisons with other infectious and inflammatory nervous system diseases.

Acute Disease↗