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Biomedical subjects

H Renz

Publications and source records attributed to H Renz.

170 records · Page 10Linked to original sources
PubMedDate not supplied

Effects of retinoids on in vitro and in vivo IgE production.

BACKGROUND: Retinoids modulate the growth and number of different cell types, including B cells. We could previously show that retinoic acid (RA) strongly inhibits CD40 + IL-4-mediated IgE production in vitro. The aim of the present study was to extend these findings regarding the potential use of retinoids for the treatment of allergic diseases. METHODS: In vitro IgE production was studied in anti-CD40 + IL-4-stimulated peripheral blood mononuclear cells (PBMC) from allergic donors in the presence of 10(-15)-10(-5) M all-trans and 13-cis RA and in ovalbumin (OVA)-sensitized BALB/c mice treated with RA (20 mg/kg) before and during sensitization. IgE and IgG1 levels were determined in the sera of the mice at day 21 after 2 injections (days 1 and 8) of aluminum hydroxide-absorbed OVA. RESULTS: All-trans and 13-cis RA inhibited in vitro IgE production from PBMC in a dose-dependent manner, but were more efficient in atopic dermatitis patients with low total serum IgE levels (< 400 kU/ml), maximal inhibition for all-trans RA at 10(-7) M (87%) and for 13-cis RA at 10(-5) M (96%) compared to patients with high serum IgE levels (>2,000 kU/ml), maximal inhibition for both all-trans and 13-cis RA at 10(-5) M (53 and 39%, respectively). In contrast, the in vivo data from OVA-sensitized mice revealed comparable total IgE and IgG1 levels in control versus all-trans RA or CD336-treated groups, specific IgE was even higher in the CD336-treated group (n = 10, 2,814 ng/ml), and was comparable in mice treated with OVA alone or with additional all-trans RA (n = 10, 1,447 and 1,354 ng/ml, respectively). CONCLUSIONS: These results indicate that the efficacy of retinoids to inhibit IgE production in vitro depends on the frequency of switched cells in the peripheral blood and that in an in vivo model using OVA-sensitized mice, retinoids fail to inhibit IgE production.

Allergens↗
PubMedDate not supplied

Mucosal tolerance induction with hypoallergenic molecules in a murine model of allergic asthma.

Type I allergy, frequently elicited by airborne allergens, has constantly increased within recent years. Birch pollen and its major allergen Bet v 1 represent a major source of type I allergens. By genetic engineering hypoallergenic Bet v 1 fragments were produced, which lost the IgE binding capacity but retained the T cell epitopes. We have established a murine model of aerosol sensitization to birch pollen and its major allergen Bet v 1, leading to type I allergic immune responses and airway hyperresponsiveness. In the present study we demonstrate that mucosal administration of recombinant Bet v 1 prior to sensitization led to allergen-specific suppression of B and T cell responses in vivo and in vitro, reduction of eosinophilic infiltration in the lungs and inhibition of airway hyperresponsiveness. Intranasal pretreatment with the nonanaphylactic fragments of Bet v 1 prevented allergic immune responses and airway inflammation to the same degree as the pretreatment with the complete molecule. We conclude from our studies that mucosal tolerance induction with hypoallergenic molecules could provide a safe and convenient treatment strategy against type I allergies.

Allergens↗
PubMedDate not supplied

Long-term NO2 exposure induces pulmonary inflammation and progressive development of airflow obstruction in C57BL/6 mice: a mouse model for chronic obstructive pulmonary disease?

Chronic obstructive pulmonary disease (COPD) is characterized by chronic inflammation of the airways, development of emphysema and irreversible airway obstruction. Macrophages, neutrophils and CD8+ T cells and their products have been shown to play an important role in the initiation and maintenance of these processes. In contrast, the mechanisms underlying COPD pathogenesis still remain uncertain. This article focuses on the generation of an animal model that mirrors some features of human COPD in association with a progredient airflow limitation.

Animals↗
PubMedDate not supplied

Macrophage colony-stimulating factor as a tumor marker for squamous cell carcinoma of the head and neck.

It has been demonstrated that in patients with epithelial ovarian cancer and malignant germ cell tumors of the ovary, macrophage colony-stimulating factor (M-CSF) is significantly elevated in the serum compared to healthy individuals. Therefore, M-CSF has been suggested as a tumor marker in these malignancies. In the present study, the tumor marker potential of the serum M-CSF concentration in patients with squamous cell carcinomas of the head and neck (SCCHN) was investigated. The serum M-CSF concentration was determined by a quantitative sandwich enzyme immunoassay in 59 patients suffering from SCCHN and 59 healthy controls. A significant difference in the mean serum concentration of M-CSF between the patients with SCCHN and the control group was found (p = 0.002). The M-CSF serum concentration correlated neither with the stage of disease nor with histopathological grading, and no correlation with serum C-reactive protein was found. The serum M-CSF concentration could be of interest as a tumor marker in SCCHN.

Biomarkers, Tumor↗
PubMedDate not supplied

Local and systemic immune responses to food antigens in neonates and infants.

Normal newborns regularly form circulating antibodies to milk proteins by 10 to 14 days of life. Concentrations of these antibodies are influenced by gestational age but not by passive maternal antibody. Secretory antibodies of the IgA and IgM-isotype directed against casein and beta-lactoglobulin are present in the saliva of normal neonates. SIgA-anti-casein is higher in saliva of newborns at risk to develop atopic disease.

Antibody Formation↗
PubMedDate not supplied

Tumor marker potential of serum matrix metalloproteinases in patients with head and neck cancer.

BACKGROUND: Elevated expression of matrix metalloproteinases (MMPs) is suggested to have tumor marker potential in various tumors. MMPs are capable of disintegrating the basement membrane, which is a main characteristic of tumor invasion. They are specifically inactivated by tissue inhibitors of metalloproteinases (TIMPs). Squamous cell carcinomas of the head and neck (SCCHN) are known to be highly invasive tumors with early locoregional metastatic spread. PATIENTS AND METHODS: To investigate the tumor marker potential of MMPs in SCCHN, MMP-2, -3, -8, -9, -13 and TIMP-1 serum levels were determined in 73 patients and compared to 74 controls. A correlation with T- and N-status, UICC-staging and grading was performed. Additionally, the influence of inflammation on the MMP serum concentration was examined. RESULTS: Significant differences between patients with SCCHN and controls were seen for MMP-3, -8 and -9. A significant correlation was found between MMP-8 concentration and T-status, N-status and UICC-staging. No correlation with the grading of the tumor was observed. Inflammatory diseases did not affect MMP and TIMP levels significantly. CONCLUSION: Some MMPs are elevated in the serum of patients with SCCHN and especially MMP-8 showed interesting tumor marker potential.

Biomarkers, Tumor↗