Biomedical subjects

V Barak

Publications and source records attributed to V Barak.

At least 55 records · Page 3Linked to original sources

PubMed1997

Serum basic fibroblast growth factor levels in patients with ischemic heart disease.

BACKGROUND: Being a potent promoter of endothelial and smooth muscle cell proliferation, basic fibroblast growth factor (bFGF) is presumed to play a key role in coronary collateral development and atherogenesis. PURPOSE: To characterize serum bFGF levels in patients with ischemic heart disease. METHODS: The study population consisted of patients with angina (n=33) and after uncomplicated myocardial infarction (n=12). The number of significantly stenosed (> or = 50%) vessels and angiographic coronary collateral score were noted. Blood was drawn immediately prior to elective coronary angiography in study patients for bFGF levels. Twenty healthy, age-matched subjects served as control for serum bFGF. RESULTS: Serum bFGF levels were undetectable in all 20 control subjects, but were detectable in 15/33 (45%) patients with angina and 3/12 (25%) post-infarction patients, respectively (P=0.002). Serum bFGF levels were detectable in 13/23 (57%) patients with 0- or 1-vessel disease, as compared with 5/22 (23%) patients with 2- or 3-vessel disease (P<0.05). Detectable serum bFGF levels were not in correlation with coronary collateral score (P=1). CONCLUSIONS: Serum levels of bFGF are elevated in patients with ischemic heart disease, particularly in those with minimal coronary artery disease. We postulate that detectable serum bFGF levels reflect active atherogenesis rather than myocardial collateral development.

Aged↗

PubMed1997

Blood serum interleukin-1 receptor antagonist in pars planitis and ocular Behçet disease.

PURPOSE: To determine the levels of interleukin-1 receptor antagonist (IL-1ra) in the blood serum of patients with idiopathic bilateral pars planitis and Behçet disease. METHODS: Five milliliters of blood was with-drawn from the cubital vein of 91 patients (58 with the ocular type and five with the combined type of Behçet disease; 28 with pars planitis) and 36 volunteers. Serum was separated from these samples and stored at -70 C until assayed. Interleukin-1 receptor antagonist levels were determined by human IL-1ra enzyme-linked immunosorbent assay kits. In patients not receiving any systemic medication, one serum sample was obtained before initiating treatment and another when the patients had been under full medical treatment for 6 weeks or more. RESULTS: Pretreatment mean +/- SD serum IL-1ra levels were 320 +/- 32 pg/ml for the patients with pars planitis, 380 +/- 54 pg/ml for patients with Behçet disease, and 271 +/- 29 pg/ml for the control subjects (no statistical significance). During treatment, a mean serum level of 352 +/- 37 pg/ml was observed in patients with pars planitis (not significantly different from control subjects) and 538 +/- 79 pg/ml in patients with ocular Behçet disease (P = .0116 compared with control subjects). The greatest increase in IL-1ra levels was observed in patients with Behçet disease who received a combination of cyclosporine and corticosteroids. CONCLUSIONS: Because IL-1ra is one of the natural immunomodulating molecules, the significant increase of serum IL-1ra levels, especially after combined treatment with cyclosporine and corticosteroids, could indicate that the therapeutic effects of this regimen may be mediated through its effects on this molecule.

Behcet Syndrome↗

PubMed1997

Vascular endothelial growth factor plasma levels correlate to the clinical picture in severe ovarian hyperstimulation syndrome.

OBJECTIVE: To assess the potential involvement of vascular endothelial growth factor in the hyperpermeability characterizing the ovarian hyperstimulation syndrome (OHSS). DESIGN: A controlled clinical study that followed the kinetics of vascular endothelial growth factor in the plasma of patients with severe OHSS from the time of admission to the hospital and until clinical resolution. SETTING: Women hospitalized with severe OHSS in a tertiary medical center. PATIENT(S): Seven patients with severe OHSS after ovulation induction for IVF and seven controls who had received a similar ovulation induction regimen and did not develop the OHSS. INTERVENTION(S): Three blood samples were obtained from each OHSS patient: upon hospitalization for severe OHSS, when significant clinical improvement was evident, and on the first follow-up visit after the patients' discharge. Ascitic fluid was obtained from all OHSS patients by therapeutic paracentesis during the active phase of the syndrome. Blood samples were drawn from the control patients 4 to 6 days after ET. All samples were assayed for vascular endothelial growth factor levels, hematocrit, E2 levels, and white blood cell count. MAIN OUTCOME MEASURE(S): Vascular endothelial growth factor levels were assayed by ELISA. Estradiol was determined by RIA. RESULT(S): Compared with the controls, high levels of vascular endothelial growth factor were detected in the plasma of all patients admitted for severe OHSS. Levels dropped significantly along with clinical improvement, reaching minimum values after complete resolution. A statistically significant correlation was found between plasma vascular endothelial growth factor levels and certain biologic characteristics of OHSS and of capillary leakage such as leukocytosis and increased hematocrit. Ascitic fluid obtained from the study patients also contained high vascular endothelial growth factor levels. CONCLUSION(S): These findings suggest the involvement of vascular endothelial growth factor in the pathogenesis of capillary leakage in the OHSS.

Adult↗

PubMed1997

Cerebrospinal fluid soluble interleukin-2 receptor in cerebral lupus.

Cerebrospinal fluid (CSF) and serum samples of 20 young adults (mean age 41 +/- 3.4 yr) with a first episode of stroke were tested for interleukin-2 (IL-2), soluble interleukin-2 receptor (SIL-2R), tumour necrosis factor-alpha (TNF-alpha) and interleukin-1-beta (IL-1 beta) levels. The results were compared to 20 patients who had neurological symptoms without evidence of a neurological disease. Three subgroups were formed according to the aetiological source of the stroke, determined by the neurological examination and evaluation. In 13 patients, the presence of atheromatous carotid plaque or cardiac disease was found. In five of the patients, stroke was the presenting symptom of systemic lupus erythematosus (SLE), which developed during the follow-up period. In two patients, no obvious aetiology could be demonstrated. The SIL-2R level was significantly higher in the CSF of patients who later developed definite SLE (P = 0.001). Other CSF interleukins and all serum interleukin levels were not significantly different in any of the groups. No correlation between albumin quotient and CSF SIL-2R was found. The SIL-2R level in the CSF may be used as a diagnostic tool to differentiate immunologically mediated vascular processes in the CNS from stroke of other origin.

Adult↗

PubMed1997

Tetracycline inhibits Porphyromonas gingivalis lipopolysaccharide-induced lesions in vivo and TNF alpha processing in vitro.

Lipopolysaccharides (LPS) are considered one of the more important virulence factors related to the pathogenesis of periodontal diseases. Based on tetracycline (TTC) ability to bind divalent metal ions, the present study was designed to examine the effect of TTC on P. gingivalis LPS-induced lesions in vivo and on LPS-induced TNF alpha production in vitro. Subcutaneous injection of 50-100 micrograms of P. gingivalis LPS into BALB/C mice induced a visible lesion within 24 h with evident tissue necrosis. Daily systemic administration of TTC for the first 4 d following LPS challenge reduced the size of the lesion, and total inhibition of lesion formation was observed in 75-100% of the treated mice. A non-related broad spectrum antibiotic, ampicillin, or the IL-1 inhibitor ML-20, had no effect on the lesion size. In order to explore some aspects of the mechanism involved, we tested the effect of TTC on LPS-induced TNF alpha secretion by human monocytes in vitro. TTC (1 mM) was found to block LPS-stimulated TNF alpha secretion. Western blotting of monocyte cytoplasmic membranes for membrane-bound TNF alpha show that TTC causes the retention of membrane-associated TNF alpha on monocyte membranes, thereby preventing the release of TNF alpha into the culture media. The results suggest the TTC is an effective in vivo therapy for preventing P. gingivalis LPS-induced subcutaneous lesion formation in the murine model. The mechanism of TTC treatment probably involves blocking the activity of metalloproteinases, including TNF alpha processing enzyme, thereby preventing LPS-induced tissue destruction.

Animals↗

PubMed1997

Regulation of the functional activity of mast cells and fibroblasts by mononuclear cells in murine and human chronic graft-vs.-host disease.

Mast cell (MC)-fibroblast-immunocompetent cell interactions may play a role in the inflammatory and fibrotic processes present in chronic graft-vs.-host disease (cGVHD). Interactions between these cell types were examined in both murine and human cGVHD models. To this purpose, cell supernatants from mice or humans with cGVHD and from controls were incubated for 6 days with either rat peritoneal MCs cocultured with 3T3 fibroblasts or with 3T3 fibroblasts alone. Supernatants in the murine model were of splenocytes from either mice with cGVHD or syngeneic controls (B-->B). Supernatants in the human model were of peripheral blood mononuclear cells (PBMC) from cGVHD patients. Two groups of controls were used in the human model-patients who had undergone bone marrow transplantation (BMT) without developing cGVHD and patients with hematological malignancies who had not undergone bone marrow transplantation (pre-BMT). Histamine release was measured in MC/fibroblast cocultures incubated with the cell supernatants. Prostaglandin E2 (PGE2) and [3H]-thymidine incorporation were measured in both MC/fibroblast cocultures or 3T3 fibroblasts alone, incubated with the cell supernatants. In the murine model, the cGVHD supernatant caused significantly more histamine release from MCs than the syngeneic supernatant or medium alone. Moreover, cGVHD and syngeneic supernatants, compared with medium alone, inhibited 3T3 fibroblast proliferation. PGE2 production by 3T3 fibroblasts was higher after incubation with the cGVHD supernatant than with the syngeneic supernatant or in medium alone. Incubation of fibroblasts with supernatants and indomethacin decreased PGE2 production and increased [3H]-thymidine incorporation. In humans, PBMC supernatants from cGVHD patients, as well as from BMT and pre-BMT controls, also displayed histamine releasing activity when cocultured with rat MCs. As with the murine cGVHD splenocyte supernatant, the human cGVHD supernatant decreased fibroblast [3H]-thymidine uptake, but the presence of MCs in the culture abrogated this inhibitory effect. In addition, the human cGVHD supernatant was found to contain high levels of PGE2 and interleukin-1 beta (IL-1 beta). The addition of neutralizing anti-IL-1 beta antibodies to the cGVHD supernatant partially inhibited its histamine-releasing activity. Skin biopsies of involved areas in cGVHD patients revealed significantly reduced numbers of MCs and showed signs of MC degranulation compared with biopsies from pre-BMT controls. Immunocompetent cell supernatants from both mice and humans with cGVHD increased basal histamine release by MCs and reduced fibroblast proliferation. The murine cGVHD supernatant also enhanced PGE2 production by 3T3 fibroblasts. Our findings indicate that complex interactions between immunocompetent cells, MCs, and fibroblasts probably play a role in cGVHD pathogenesis.

3T3 Cells↗

PubMed1997

Soluble interferon-gamma receptor and interferon-gamma in patients undergoing allogeneic bone marrow transplantation for hematological malignancies.

Interferon-gamma (IFN-gamma) is known to be involved in graft rejection of solid organs and acute graft-versus-host disease (GVHD). Its role, and especially that of soluble IFN-gamma receptor (sIFN-gamma R), in bone marrow transplantation (BMT) has not been established. We evaluated the sera of 27 patients following BMT. Fourteen of them underwent uneventful BMT, whereas 13 developed transplant-related complications, including acute GVHD (n = 5), early rejection (n = 4), or relapse of basic disease (n = 4). Soluble IFN-gamma R and IFN levels were evaluated at day -10 (preconditioning), day 0 (day of BMT), day of engraftment, and during BMT-related complications using sIFN-gamma R-specific monoclonal antibodies (McAB) followed by double-sandwich ELISA, and a sensitive radioimmunoassay respectively. In normal controls (n = 80) sIFN-gamma R and IFN-gamma levels in the sera were 0.5 +/- 0.05 and 0.3 +/- 0.04 ng/ml respectively. Soluble IFN-gamma R levels increased in direct correlation with engraftment (0.63 +/- 0.11 ng/ml at the day of BMT to 1.43 +/- 0.16 ng/ml at the day of engraftment; n = 14; P < 0.001). IFN-gamma levels increased in direct correlation with engraftment (0.37 +/- 0.03 ng/ml at the day of BMT to 5.69 +/- 1.64 ng/ml at the day of engraftment; n = 14; P < 0.001). In five patients with GVHD sIFN-gamma R levels increased from 0.43 +/- 0.19 ng/ml at the day of BMT to 1.73 +/- 0.17 ng/ml (P < 0.004) at the time of GVHD. Similarly, IFN-gamma levels increased from 0.43 +/- 0.08 ng/ml at the day of BMT to 3.03 +/- 0.5 ng/ml at the time of GVHD (P < 0.05). Both graft rejection and early relapse were associated with an elevation of IFN-gamma levels. In short, both s-IFN-gamma R and IFN-gamma were found to be significantly elevated during engraftment and GVHD. Hence these cytokines may be used as a tool for assessing engraftment and AGVHD.

Adolescent↗

PubMed1996

Stem cell factor (SCF) synergizes with megakaryocyte colony stimulating activity in post-irradiated aplastic plasma in stimulating human megakaryocytopoiesis.

Plasma obtained from lethally irradiated animals contains a megakaryocyte (MK) growth factor which has recently been identified as the ligand for the c-mpl receptor and has been named thrombopoietin (TPO). We demonstrate that post-irradiation aplastic canine plasma (PICS-J) and plasma from a human subject (ML) who was accidentally exposed to lethal irradiation, contain high levels of this activity, which support both MK proliferation and maturation in a dose-dependent manner. These plasma were far more active in stimulating human MK colony formation than other types of thrombocytopenic plasma or a number of exogenously added human recombinant cytokines and their combinations. The addition of stem cell factor (SCF), which alone has a minimal stimulatory affect, to post lethal-irradiation plasma provided a synergistic stimulation of megakaryocytopoiesis both in colony assays and liquid cultures. In colony assays, the combination of SCF with PICS-J or ML almost doubled the number of burst forming units (BFU-MK) and provided a 1.5-fold increase in colony forming units (CFU-MK). A 1.6-fold increase in the number of CD34+ BM cell-derived MK colonies was also elicited. In liquid cultures, the presence of both SCF and PICS-J or ML induced the appearance of a high proportion of CD34+ (6.56% vs 0.6% control) and CD41+ (3.5% vs 1.2% control) cells after 3 days in culture. By day 10, 66.8 x 10(4) CD41+ cells and 29.8 x 10(4) CD34+ cells were derived from 2 x 10(6) BMMC originally seeded. We propose that these unique plasma, which do not contain elevated level of IL-6, IL-3, GM-CSF, IL-1 beta, erythropoietin or SCF, probably contain high levels of TPO. The addition of SCF to the post-irradiation plasma provides a synergistic stimulation of megakaryocytopoiesis which may become relevant for future clinical application.

Anemia, Aplastic↗

PubMed1996

The novel immunomodulator, Linomide, stimulates interleukin-2-induced human natural killer (NK) cell and PHA-stimulated T cell proliferation from normal donors.

Donor-derived cell-mediated immunotherapy has been shown to be an effective tool for reinduction of remission in chronic myeloid leukaemia (CML) patients who have relapsed post-bone marrow transplantation (BMT). Linomide, quinoline-3-carboxamine (LS 2616), is a new immunomodulator shown to increase the number of NK precursors in mice in addition to upregulating the quantity of CD56(+), CD3(-) and CD16(+) NK cells in the peripheral blood of patients following autologous BMT (ABMT). We investigated the in vitro effects of Linomide on NK activity of normal human donors. Large granular lymphocytes (LGLs) and NK cells were incubated overnight with Linomide (0.02-4.8 mg/ml), recombinant human interleukin-2 (IL-2, 75 IU/ml), or a combination of both. Linomide, at 0.02-0.3 mg/ml, augmented IL-2-induced proliferation of LGLs and NK cells in an inversely proportional manner. In contrast, Linomide at 0.6-4.8 mg/ml inhibited IL-2-induced proliferation of LGLs and NK cells in a dose-dependent manner. Linomide was able to potentiate phytohemaglutinin-induced CD3(+) cell proliferation. In addition, supernatants derived from Linomide treated CD3(+) T cells were able to mimic the direct stimulatory effect of Linomide on activated NK cell proliferation. These supernatants were found to have low levels of tissue necrosis factor-alpha (TNF-alpha) and interleukin-1 (IL-1) and therefore Linomide stimulation of NK and T cell proliferation may be due to its inhibitory effect on the secretion of these cytokines by activated CD3(+) T cells. Linomide had no effect on cytotoxicity nor on the phenotypic expression of resting and IL-2-activated LGLs or NK cells. In view of our results, Linomide could possibly play a potential role in adoptive cell-mediated immunotherapy post-BMT.

Adjuvants, Immunologic↗

PubMed1996

Granulocyte-macrophage colony-stimulating factor dependent monocyte-mediated cytotoxicity post-autologous bone marrow transplantation.

We investigated the in vitro antitumor activity of monocytes derived from autologous bone marrow transplanted (ABMT) patients treated in vivo with granulocyte-macrophage colony-stimulating factor (GM-CSF). Thirty-four patients (17 female, 17 male), median age 42 (range 3-57) years, were enrolled in the study. Fourteen patients were diagnosed with non-Hodgkin's lymphoma (NHL), eight with Hodgkin's disease (HD), nine with breast cancer and three with neuroblastoma. Six patients who did not receive GM-CSF post-ABMT served as controls. We assessed cytotoxicity, antibody-dependent cellular cytotoxicity (ADCC), expression of the activation antigen CD16, and cytokine production by an enriched population of monocytes (> 90% CD+14) pre-, during and post-GM-CSF administration. Within the group of patients receiving treatment, ADCC was significantly higher during in vivo GM-CSF administration than post-therapy (P < 0.05) and in 50% of these patients, ADCC increased during in vivo GM-CSF administration over pretreatment values. In addition, in vivo GM-CSF administration caused the monocytes to secrete elevated levels of tumor necrosis factor-alpha (TNF-alpha) and GM-CSF (P < 0.05). We conclude that GM-CSF augments monocyte-mediated cytotoxicity post-ABMT, and therefore may have a role in controlling minimal residual disease post-transplant.

Adolescent↗

PubMed1996

The effects of early and late administration of M-20 derived interleukin-1 inhibitor on experimental systemic lupus erythematosus.

M-20 interleukin-1 inhibitor is produced by a myelomonocytic cell line. The effects of this molecule, mediated via IL-1 inhibition, include decreased proliferative responses of mouse thymocytes, human T-cells and fibroblasts and reduction in parameters of acute inflammation. Previously, we have demonstrated the emergence of a disease resembling systemic lupus erythematosus (SLE) in naive mice immunized with anti-DNA antibodies carrying different pathogenic idiotypes. The disease was manifested by increased titers of various mouse antibodies, concomitant with the appearance of elevated erythrocyte sedimentation rate (ESR), proteinuria and leukopenia. We have applied this model of experimental SLE (immunized with MIV-7, a human monoclonal antibody) to evaluate the influence of M-20 IL-1 inhibitor, administered at different stages (2 weeks before, 1 month and 3 months following immunization) for a period of 2 weeks, on the findings of the disease in mice. It was shown that M-20 IL-1 inhibitor given 2 weeks prior to the immunization resulted in suppression of the disease induction as documented by lower antibody titer level (30%-50% in the immunized mice as compared with controls). Furthermore, reduced autoantibody levels were accompanied by other beneficial findings consisting of lower ESR, less severe proteinuria and elevated leukocyte counts. No beneficial effects of M-20 IL-1 inhibitor were observed when the agent was administered 1 or 3 months following immunization. We conclude that M-20 IL-1 inhibitor has a favorable effect on experimental SLE in mice, provided it is administered before induction of the disease.

Animals↗

PubMed1996

Plasma inflammatory cytokines correlate to the ovarian hyperstimulation syndrome.

The objective of this study was to follow the kinetics of four inflammatory cytokines in the plasma and ascitic fluid of seven patients who developed severe ovarian hyperstimulation syndrome (OHSS) after induction of ovulation for in-vitro fertilization. Blood samples were obtained from these patients at three different times: upon hospitalization; when significant clinical improvement was evident; and after complete resolution. Samples were analysed for interleukin-1 (IL-1), interleukin-6 (IL-6), interleukin-8 (IL-8) and tumour necrosis factor alpha (TNF-alpha). Ascitic fluid was obtained by therapeutic paracentesis from all study patients during the active phase and analysed for these cytokines. Two control groups were available: the first included 15 women undergoing controlled ovarian stimulation for in-vitro fertilization without developing OHSS, while the second consisted of 25 healthy women not undergoing ovulation induction or any other medical treatment. High concentrations of IL-1, IL-6 and TNF-alpha were detected in all individuals upon admission for severe OHSS. Concentrations dropped significantly along with clinical improvement, reaching normal values after complete resolution. A statistically significant correlation was found between plasma cytokine concentrations and certain biological characteristics of the syndrome such as leukocytosis, increased haematocrit, and elevated plasma 17-beta-oestradiol concentrations. Ascitic fluid obtained from the study patients contained high IL-6 and IL-8 concentrations, while other cytokines were unaltered. These results suggest close association between inflammatory cytokines and the pathophysiology of the ovarian hyperstimulation syndrome.

Adult↗

PubMed1996

Protection against endotoxic shock and lipopolysaccharide-induced local inflammation by tetracycline: correlation with inhibition of cytokine secretion.

Septic shock results from excessive stimulation of host immune cells, particularly monocytes and macrophages, by lipopolysaccharide (LPS) released from gram-negative bacteria. Macrophage-derived cytokines, such as tumor necrosis factor alpha (TNF-alpha) and interleukin-1beta (IL-1 beta), have been identified as central mediators in the pathogenesis of septic shock and the resultant mortality. Therefore, these cytokines were targets for experimental therapy for septic shock. Because of tetracycline's ability to intervene in cellular mechanisms involved in cytokine secretion, we tested the effect of tetracycline on LPS-induced septic shock and inflammatory lesions in mice. Tetracycline was found to protect mice against LPS-induced lethality and to abolish clinical signs of LPS-induced inflammatory lesions. This protection correlates with tetracycline's ability to reduce LPS-induced TNF-alpha levels in serum. Furthermore, tetracycline was found to inhibit LPS-induced TNF-alpha and IL-1 beta secretion, but not cytokine mRNA accumulation, in human monocytes in vitro. The results presented here suggest that tetracycline is a potent drug for LPS-induced pathology and that its mechanism of action involves blockage of posttranscriptional events of cytokine production.

Animals↗

PubMed1996

Increased serum concentrations of interleukin-1 beta in patients with coronary artery disease.

OBJECTIVE: To assess serum interleukin-1 beta (IL-1 beta) concentrations in patients with ischaemic heart disease, to characterise subgroups of patients with raised IL-1 beta concentrations, and to examine whether serum IL-1 beta concentrations correlate with non-specific indices of inflammation. DESIGN: Survey study of patients with ischaemic heart disease. SETTING: Cardiac catheterisation laboratory of a tertiary medical centre. PATIENTS: Consecutive patients with angina pectoris and patients recovering from uncomplicated acute myocardial infarction and undergoing elective coronary angiography. RESULTS: Mean(SD) serum IL-1 beta concentrations were higher (P < 0.001) in patients with angina and < 50% coronary artery stenosis (n = 11; 18.8(19.9) pg/ml), patients with angina > or = 50% stenosis (n = 23; 10.2(11.4) pg/ml), and patients 8(0.8) days post-infarction (n = 13; 4.4(5.8) pg/ml) than in 15 healthy, age-matched controls (0.3(0.5) pg/ml). Serum IL-1 beta concentrations did not correlate with total blood leucocyte counts (r = -0.07, P = NS), blood lymphocyte counts (r = -0.24, P = NS), and blood monocyte counts (r = -0.29, P = NS), or with fibrinogen (r = -0.16, P = NS) and C-reactive protein concentrations (9(10.5) mg/dl v 14.1(19) mg/dl for patients with undetectable and detectable concentrations, respectively, P = NS). CONCLUSION: Serum IL-1 beta concentrations are raised in patients with ischaemic heart disease, in particular in those with minimal coronary artery disease and angina. The precise role of IL-1 beta in coronary artery disease remains to be determined.

Aged↗

PubMed1996

Defective in vitro granulopoiesis in patients with anorexia nervosa.

Patients with anorexia nervosa (AN) frequently suffer from a mild degree of anemia and from moderate leukopenia on top of their undernourished state and metabolic disarrangements. To evaluate in vitro granulopoiesis and its relationship to cytokine production and undernutrition, we have studied 10 adolescent girls with moderate AN (age range, 13.5-18.0). Study methods included assessment of peripheral blood (PB) granulocyte-macrophage colony-forming cells (GM-CFC) of the patients and age-matched controls, and determination of plasma and conditioned medium (CM) of mononuclear cells levels of IL-1, IL-3, IL-6, granulocyte-macrophage colony-stimulating factor (GM-CSF) and tumor necrosis factor (TNF), all of which may play a role in GM-CFC growth regulation. GM-CFC numbers were significantly lower in AN patients compared with the normal controls (13.09 +/- 11.15 versus 39.33 +/- 26.61 colonies/5 x 10(5) cells, p < 0.01). No inhibitory effect was found in either plasma or CM of patients with AN. However, when CM were applied to non-recombinant human GM-CSF-stimulated normal bone marrow GM-CFC targets, the number of colonies stimulated by the CM of patients with AN was significantly lower than those stimulated by the CM of the controls (73.5 +/- 20.1 versus 113.0 +/- 11.6, p < 0.025). GM-CSF concentrations in CM were significantly lower in patients with AN compared with normal controls, but no such differences were found in IL-1, IL-3, IL-6, or TNF concentrations. These results indicate defective in vitro granulopoiesis in AN patients, manifested by a reduction of both GM-CFC and GM-CSF. It has to be determined whether these changes are the result of the basic disease process or are they due to malnutrition.

Adolescent↗

PubMed1996

Cytokine-mediated regulation of type IV collagenase expression and production in human trophoblast cells.

The invasive property of trophoblast cells is dependent on the activity of proteolytic enzymes of the metallo- and serine proteases family. Interleukin-1 (IL-1) was found to be involved in the regulation of these proteases in various systems, serving as an important modulator in trophoblast physiology (e.g. induction of hCG beta, cytokines, and others). Therefore, consideration is given in this report to the role of IL-1 in the regulation of metalloprotease activity in human trophoblasts. Human trophoblast cells were isolated from first trimester placentas by trypsin degradation and Percoll fractionation. Primary cell cultures of first trimester trophoblasts constitutively elaborated two species of collagenase type IV (92 and 72 kDa), as assessed in gelatin matrix. Treatment with IL-1 further augmented the 92-kDa type IV collagenase secretion in a dose-dependent manner. Furthermore, IL-1 significantly (P < 0.01) increased 92-kDa collagenase gene expression by trophoblast cells, as determined by solution hybridization/ribonuclease protection assay. Both the increase in gene expression and protein biosynthesis of the 92-kDa collagenase type IV were neutralized by the soluble IL-1 receptor, indirectly suggesting a receptor-mediated response. Interestingly, transforming growth factor-beta a putative modulator of IL-1 induced effects, was shown to induce the 92-kDa collagenase type IV secretion as well. These results provide indirect evidence supporting the idea that IL-1 and transforming growth factor-beta may play an intermediary role in trophoblast invasion at the feto-maternal interface by regulating trophoblast expression of 92-kDa type IV collagenase, a protease of prime importance in trophoblast invasion.

Cells, Cultured↗

PubMed1996

Human monocyte response to cementum extracts from periodontally diseased teeth: effect of conditioning with tetracycline.

Monocyte inflammatory cytokines, such as TNF alpha and IL-1 beta, have been implicated in the pathogenesis of periodontal destruction. The present study was designed to test the ability of extracts of cementum from periodontally diseased teeth to induce the secretion of these mediators by monocytes, to evaluate the role of adsorbed endotoxin in this process, and to test the effect of cementum conditioning with tetracycline on the monocyte response. Human monocytes were incubated with varying concentrations of cementum extracts, and TNF alpha and IL-1 beta levels in the media were measured. The results showed that while extracts of healthy cementum had no effect on monocyte secretion, concentration as low as 0.5 mg/ml of cementum from diseased sites raised the levels of TNF alpha and IL-1 beta secretion 10-fold. This response was dose-dependent. Diseased cementum were found to contain 1.5 ng/mg endotoxin, while endotoxin was not detectable in the extracts of the healthy cementum. However, neutralization of the endotoxin by polymyxin B only partially reduced the monocyte secretory response by 50 to 70%, suggesting that other factors in the extracts are also involved in monocyte stimulation. To simulate the effect of root conditioning, cementum was first agitated in a tetracycline or control solution prior to its extraction in media. Pretreatment of diseased cementum with tetracycline (50 mg/ml) was found to block the secretion of TNF alpha from cementum-stimulated monocytes. Pretreatment of the diseased cementum with 10 mg/ml tetracycline was not more effective than saline and HCI controls, with all treatments reducing cytokine secretion by approximately 80%. The direct addition of tetracycline to cementum-stimulated monocyte culture was found to block TNF alpha secretion in a dose dependent manner. The results suggest that extracts from diseased cementum are potent stimulators of monocyte secretion, and that endotoxin as well as other factor(s) appear to be involved. These factors are partially extracted by washing and a 10 mg/ml tetracycline solution is not more effective than saline in achieving this goal. In addition, tetracycline was found to be a potent inhibitor of TNF alpha secretion by cementum-stimulated monocytes, suggesting a novel mechanism for this drug in periodontal therapy.

Analysis of Variance↗

PubMed1996

Levels of cytokines and collagen type I and type III as a function of age in human gingivitis.

The objective of this study was to examine the age-dependent relationships between levels of inflammatory cytokines and collagen in human gingival inflammation. The gingival biopsies were obtained from 142 patients, divided into the following age groups: 6 to 14 years (prepubertal children); 18 to 35 years (young adults); 36 to 54 years (mature adults); and 55 years or above. The patients were also divided according to the severity of gingivitis. The tissues were analyzed for the contents of the inflammatory cytokines interleukin (IL)-1 beta, IL-6, IL-8, and tumor necrosis factor alpha (TNF-alpha) using specific ELISA kits, and interstitial collagen type I and type III using the ELISA method and specific antibodies. We found that in young adults, levels of IL-1 beta and IL-6 were significantly higher in inflamed than in non-inflamed gingiva. Total collagen in the young adults, however, was lower in inflamed than in non-inflamed gingiva. There was no significant difference in the levels of either IL-8 or TNF-alpha between inflamed and non-inflamed gingiva independent of age. No difference in the level of collagen type I between the inflamed and non-inflamed gingiva was found in any age groups. The level of collagen type III was lower in inflamed than in non-inflamed gingiva in both children and > or = 55 year group. The results indicate a disparity in the effect of age on the levels of cytokines and of collagen type I and type III in both clinically normal and inflamed gingiva.

Adolescent↗