Biomedical subjects

Alojz Ihan

Publications and source records attributed to Alojz Ihan.

9 recordsLinked to original sources

PubMed2007

Effect of apoptosis and reactive oxygen species production in human granulosa cells on oocyte fertilization and blastocyst development.

PURPOSE: The aim was to establish the impact of human granulosa cell apoptosis and reactive oxygen species (ROS) production on fertilization competence of the oocyte, embryo developmental stage and implantation rate. METHODS: Thirty women undergoing IVF-ET for tubal factor infertility were included; GnRH antagonists and gonadotrophins were used for ovarian stimulation. Granulosa cells were isolated from each aspirated follicle using gradient centrifugation. Apoptosis was studied by flow cytometry using annexin V and propidium iodide. ROS production was studied with hydroethidine staining and analyzed by flow cytometry. RESULTS: There were no differences in characteristics of granulosa cells between the follicles with fertilized and non-fertilized oocytes. The analyzed characteristics of granulosa cells in corresponding follicles had no effect on embryo developmental stage on day 5. The percentage of ROS producing granulosa cells was lower in the follicles giving rise to blastocysts that resulted in implantation compared to those that did not (39.9% versus 69.9%, P = 0.031). CONCLUSIONS: Apoptosis and ROS production in granulosa cells have no significant impact on fertilization and do not correlate with the development of blastocysts. An increased percentage of ROS producing granulosa cells results in fewer oocytes retrieved and diminishes implantation rate.

Adult↗

PubMed2006

Interleukin-10, T-lymphocytes, and cardiac output in children after ventricular septal defect repair: a pilot study.

OBJECTIVE: To evaluate the acute inflammatory response and cardiac output in children after surgery for ventricular septal defect. DESIGN AND SETTING: Prospective, observational study in a level III multidisciplinary neonatal and pediatric intensive care unit. PATIENTS: Ten children undergoing open-heart surgery for ventricular septal defect. INTERVENTIONS: All children received methylprednisolone (30 mg/kg) in cardiopulmonary bypass (CPB) prime. MEASUREMENTS AND RESULTS: Before and after cardiopulmonary bypass, plasma interleukin-10 and tumor necrosis factor alpha were measured by enzyme-linked immunosorbent assay, and lymphocyte subsets in peripheral blood by flow cytometry. Relative values (post-/pre-CPB) of interleukin-10 and tumor necrosis factor alpha were calculated. The cardiac index (CI) was measured continuously beat-to-beat by a pulse contour analysis (PiCCO). Children above the cutoff value (median cardiac index value 3.0 l min(-1) m(-2)) were designated as the normal CI group and those below this value as the low CI group. In the normal CI group the relative values of interleukin-10 remained almost seven times higher than pre-CPB values at 24 h while in the low CI group they decreased almost to pre-CPB values. Furthermore, the normal CI group, but not the low CI group, exhibited more than threefold decrease in T-lymphocytes (lymphocyte T-cells, T-helper cells, and cytotoxic T-cells) 24 h after CPB. CONCLUSIONS: Children operated on for ventricular septal defect developed either a normal or low CI. The higher relative values of interleukin-10 and lower counts of lymphocyte T-cells, T-helper and cytotoxic T-cells differentiated the normal CI group from the low CI group at 24 h after cardiopulmonary bypass.

Cardiac Output↗

PubMed2006

Infliximab reduces the number of activated mucosal lymphocytes in patients with Crohn's disease.

BACKGROUND: Infliximab is an effective treatment for Crohn's disease in patients with poor prior response to conventional therapy. The mechanism by which infliximab induces clinical improvement is not completely known. AIM: The aim of the study was to investigate the influence of infliximab on immunological parameters in peripheral blood and inflamed intestinal mucosa. METHODS: Twenty-five patients with Crohn's disease (11 with luminal and 14 with fistular form) underwent treatment with infliximab. The lymphocyte populations from the peripheral blood and the inflamed intestinal mucosa were analysed by flow cytometry before treatment and 14 days later. RESULTS: After treatment, the peripheral blood analysis showed a significant increase in the percentage of CD19 cells and the concentrations of CD3, CD4, CD8 and activated (HLA DR positive) T cells, while the percentage of NK cells was reduced. In the inflamed mucosa, a significant decrease in the percentage of activated T cells and expression of HLA I molecules by epithelial cells was noted. CONCLUSIONS: Infliximab profoundly downregulates inflammation in the intestinal mucosa of patients with Crohn's disease. This effect is manifested by a reduction of activated T cells, main producers of proinflammatory cytokines, in the inflamed mucosa.

Adult↗

PubMed2005

Dendritic cells incubated with irradiated tumor cells effectively stimulate T lymphocyte activation and induce enhanced expression of CD69, CD25 as well as production of IFNgamma and IL4.

Understanding of immunological processes at the molecular level in the cancer-bearing organism is the prerequisite for development of specific tumor vaccines. Most of these vaccines are aimed at enhancing the immunogenicity of the antigens presented by the tumor cells. Since dendritic cells (DC) are potent antigen presenting cells (APC) in the organism, they are considered as a powerful tool to deliver the signals essential for the activation of immune system. In an attempt to clarify the functional importance of DC in the process of anti-tumor vaccination, we characterized the effect of DC activated with a classical tumor vaccine (mixture of irradiated B16F1 tumor cells and MVE-2) on the activation of T lymphocytes. The T lymphocyte activation was assessed by determination of expression of CD25, CD69, and intracellular IFNgamma and IL4 production. Activated DC significantly increased the proportion of CD25+ and CD69+ cells as well as IFNgamma+ and IL4+ cells among CD3+ T lymphocytes. On the other hand, the direct effect of the tumor vaccine on T lymphocytes was just an increment in the proportion of IL4+ T lymphocytes. With the results of in vivo experiments, the phagocytic cells (including DC) were proved to be essential for establishing an active protection against tumor cells (tumor development), but more importantly, also for formation of the memory cell pool. These data indicate that DC loaded with tumor antigens are required for effective stimulation of T lymphocytes, and that the phagocytic cells (including DC) are essential for the anti-tumor immunity triggered by this kind of vaccine.

Animals↗

PubMed2004

Lipodystrophy and metabolic abnormalities in Slovenian HIV-infected patients.

The purpose of this cross-sectional survey was to estimate the prevalence of lipodystrophy (LD) and metabolic abnormalities in Slovenian patients with HIV infection. All patients receiving highly active antiretroviral therapy (HAART) for more than six months (treated group) and all known antiretroviral-naive patients (control group) were consecutively evaluated between October and December 2003. Eighty-one treated patients (81% male, 19% female), and 18 controls (83% male, 17% female) were included in the study. In the treated group, the duration of HAART at the time of evaluation was 3.7 +/- 2.3 years. Twenty-nine treated patients (36%) had at least one sign of LD: isolated peripheral atrophy was present in nine (31%), isolated fat accumulation in four (14%) and a mixed syndrome in 16 (55%). Patients with evidence of LD were older than those without LD and had a higher prevalence of AIDS and a longer duration of HAART, but there were no differences in HIV transmission categories, plasma RNA level, CD4+ count, HAART regimens or BMI. Insulin resistance was observed in 31 treated patients (38%), of whom 22 (27%) had impaired glucose tolerance and six (7%) had diabetes mellitus. Dyslipidemia was the predominant metabolic abnormality in the treated group, observed in 58 patients (72%). Levels of total cholesterol were increased in 43 patients (53%), and hypertriglyceridemia was noted in 40 (49%). The duration of HAART in patients with metabolic syndrome was longer than in patients without the syndrome. Lipid- and glucose-related abnormalities were more frequent in patients with LD than in those without. A total of 60 treated patients (74%) had at least one sign of LD and/ or one metabolic alteration at the time of evaluation. In the control group, none of the patients showed evidence of LD, and metabolic abnormalities were less common than in the treated group: six patients (33%) had one or more metabolic abnormalities. HIV-related LD syndrome includes a variety of clinical and biological manifestations, which can be included in a case definition. The metabolic effects of HAART could lead to an increase in cardiovascular disease. The patient's metabolic parameters should be evaluated before starting treatment, and appropriate management of LD and glucose- or lipid-related metabolic changes is essential.

Adult↗

PubMed2004

IFN-beta1a and IFN-beta1b have different patterns of influence on cytokines.

Multiple sclerosis is characterized by elevated levels of proinflammatory cytokines produced by Th1 cells and decreased levels of anti-inflammatory cytokines produced by Th2 cells. IFN-beta treatment shifts the immune response from the Th1 to Th2 pattern, thus enhancing the production of anti-inflammatory Th2 cytokines such as IL-4, IL-10, and decreasing the production of proinflammatory Th1 cytokines such as IFN-gamma. To determine which IFN-beta has the stronger immunomodulatory effect we compared the levels of IL-4, IL-10, and IFN-gamma of 12 relapsing-remiting MS patients treated with IFN-beta1b (Betaferon) with those of 10 patients treated with IFN-beta1a (Avonex). There were no statistically significant differences in duration of disease, number of relapses before and during treatment, and in EDSS after 2 years of treatment. After 1 year of treatment the concentration of IFN-gamma was significantly lower in the Betaferon group, and concentrations of IL-4 and IL-10 were significantly higher in the Avonex group. It appears that IFN-beta1b has a downregulatory effect on both Th1 and Th2 cytokines, while IFN-beta1a causes a shift of the cytokine profile toward the Th2 phenotype. These two IFN have different influences on the pattern of cytokines in MS: IFN-beta1a enhances the production of anti-inflammatory cytokines IL-4 and IL-10 and IFN-beta1b decreases the production of the proinflammatory cytokine IFN-gamma.

Adjuvants, Immunologic↗

PubMed2003

A cka-gfp transcriptional fusion reveals that the colicin K activity gene is induced in only 3 percent of the population.

In prokaryotes, only a few examples of differential gene expression in cell populations have been described. Colicin production in natural populations of Escherichia coli, while providing a competitive advantage in the natural habitat, also leads to lysis of the toxin-producing cell. Colicin K synthesis has been found to be induced due to an increase in ppGpp (I. Kuhar, J. P. van Putten, D. Zgur-Bertok, W. Gaastra, and B. J. Jordi, Mol. Microbiol. 41:207-216). Using two transcriptional fusions, cka-gfp and cki-gfp, we show that at the single-cell level, the colicin K activity gene cka is expressed in only 3% of the bacterial population upon induction by nutrient starvation. In contrast, the immunity gene cki is expressed in the large majority of the cells. Expression of the cka-gfp fusion in a lexA-defective strain and in a relA spoT mutant strain indicates that differential expression of cka is established primarily at the level of transcription.

Bacterial Proteins↗

PubMedDate not supplied

Ocular surface changes induced by topical antiglaucoma monotherapy.

PURPOSE: To investigate the expression of inflammatory markers HLA-DR in impression cytology specimens from patients receiving topical antiglaucoma monotherapy. METHODS: Impression cytology specimens were obtained from patients taking no topical medication (n = 13) and from primary open-angle glaucoma or ocular hypertensive patients taking one topical medication for at least 3 months (latanoprost n = 14; betaxolol n = 12; timolol n = 14). None of the patients had any signs of ocular surface inflammation as detected by slit-lamp examination, a normal Schirmer's test and tear breakup time. The expression of HLA-DR on epithelial cells and T lymphocytes was analysed by flow cytometry. RESULTS: A significant increase in HLA-DR on epithelial cells in patients on monotherapy was detected (latanoprost p < 0.05; betaxolol p < 0.01; timolol p < 0.01). Although the duration of treatment differed significantly between individual groups, there was no significant correlation between the length of monotherapy and the expression of inflammatory markers by epithelial cells and T lymphocytes. In the latanoprost group, the increased expression of HLA-DR was associated with a shorter duration of treatment. CONCLUSIONS: The flow-cytometric results indicate that administration of a single topical medication preserved with benzalkonium chloride, irrespective of type, for 3 months or more induced a significant degree of subclinical inflammation detected as increased expression of HLA-DR on conjunctival epithelial cells.

Administration, Topical↗

PubMedDate not supplied

CD19+ in intestinal mucosa predict the response to infliximab in Crohn's disease.

BACKGROUND/AIMS: Infliximab is an effective treatment for Crohn's disease, yet about 30% of patients have a weak or no response. The aim of the study was to determine if the likelihood of a patient achieving complete remission 3 months after treatment with infliximab can be predicted from immunological parameters measured in peripheral blood and inflamed intestinal mucosa before the treatment. METHODOLOGY: 25 patients with Crohn's disease resistant to conventional therapy underwent treatment with infliximab. Samples of peripheral blood and inflamed intestinal mucosa were analyzed by flow-cytometry before infliximab administration. The clinical response was evaluated after 3 months. RESULTS: At 3 months post-treatment, 11 (44%) patients were in complete remission, while 14 (56%) had no remission. Logistic regression analysis revealed that 50% of patients having 2.29% of CD19+ cells in inflamed intestinal mucosa may be expected to achieve complete remission. If the proportion of CD19+ cells in the inflamed mucosa is 5%, the probability of the patient achieving complete remission following treatment rises to 85%. CONCLUSIONS: This is the first study which found that a high percentage of CD19+ cells in the inflamed intestinal mucosa of a patient with Crohn's disease may predict long remission after infliximnab therapy.

Antibodies, Monoclonal↗