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Biomedical subjects

C Bachert

Publications and source records attributed to C Bachert.

At least 73 records · Page 4Linked to original sources
PubMed2000

Endoscopic endonasal surgery (EES) in skull base repairs and CSF leakage.

This report aims to summarise the current role of Endoscopic Endonasal Surgery (EES) for skull base and cerebrospinal fluid (CSF) leakage repair, to provide some guidelines for the clinical diagnosis and technical procedures of repair, to demonstrate the limits of this approach and to discuss the Belgian experience of the recent years. Endoscopic surgery for chronic sinus disease is being performed with increasing frequency and CSF leak is an significant potential complication of this surgery, although the incidence of osteo-meningeal perforations in endonasal sinus surgery is below 1% overall. CSF leakage bears the risk of meningeal or intracranial infection and complication and therefore should be repaired as soon as recognised. Following proper localisation of the leak, repair is safely performed in most of the cases by endonasal route with the help of free mucoperiostal flaps taken from the inferior or middle turbinates. This also applies for lesions of other aetiologies. The Belgian data support the statement that the endonasal endoscopic approach is a suitable and successful technique to close CSF leaks in the vast majority of our patients.

Adult↗
PubMed2000

Endoscopic sinus surgery for juvenile nasopharyngeal angiofibroma.

Juvenile nasopharyngeal angiofibroma is a rare tumour of the head and neck with very specific characteristics: adolescent males, choana-nasopharynx, pterygomaxillary fossa widening, specific and intense vascularisation. Staging is very important in the decision of the surgical approach. Endoscopic management of juvenile nasopharyngeal angiofibroma is technically possible after preoperative embolisation. Up to now 13 angiofibroma have been treated using the endonasal endoscopic sinus surgery approach in Belgium (Leuven 8; Mont-Godinne 2; Ghent 1; Liege 1; Woluwe 1). In smaller tumors endoscopic resection has been successful in four cases without any recurrence. Five larger tumors, extending in the pterygomaxillary fossa, were also successfully resected. Extension into the infratemporal fossa or the cavernous sinus can be endoscopically removed, but recurrences may occur as they do after classical, external approaches. In conclusion, the endoscopic approach is an acceptable alternative in small to middle sized juvenile nasopharyngeal angiofibroma.

Adolescent↗
PubMed2000

The common cold.

Upper respiratory tract infections are one of the most common infectious diseases in man and are mainly caused by rhinoviruses. A rhinoviral cold is characterized by a neutrophilic inflammatory reaction with relatively mild symptoms that rather result from the host inflammatory response to the virus than from a direct viral cytotoxic effect. As regulators of chemotaxis, transmigration and activators of inflammatory and immunocompetent cells, cytokines and mediators were shown to play a crucial role in the pathogenesis of a rhinovirus infection.

Common Cold↗
PubMed2000

Rhinological aspects of cystic fibrosis.

Cystic fibrosis is a genetic disorder of the exocrine glandular function leading to the formation of thick mucus in the nasal and paranasal cavities. Nearly all the patients develop sinus disease but not all have complaints. Two different sinus diseases can be found: chronic sinusitis and nasal polyposis. Only the symptomatic cases have to be treated. Medical treatment consists of antibiotherapy for chronic sinusitis and nasal steroid sprays for nasal polyps. Sinus surgery is frequently needed in case there is a persistence of symptoms (and before lung transplantation).

Cystic Fibrosis↗
PubMed1999

[A punch for enlarging the frontal ostium].

BACKGROUND: The opening of the frontal sinus represents a challenge in primary and revision surgery of the paranasal sinuses. RESULTS: Newly developed frontal sinus punches were used in 35 cases of primary or secondary surgery of the frontal sinus, with a post operative follow-up period of up to 18 months. So far, the results are promising. CONCLUSIONS: Forward-cutting angled punches adapted to the anterior skull base have been developed to reduce the risk of trauma to mucosal structures when broadly exposing the frontal sinus through an anterior approach.

Craniotomy↗
PubMed1999

[Cytokines and chemokines in paranasal sinus diseases].

BACKGROUND: New insights into inflammatory processes became possible by investigating the pattern of cytokines and chemokines as well as adhesion molecules in different acute and chronic sinus diseases since the last decade. This review aims to update and discuss findings of in vitro and in vivo studies concerning the role of cytokines and chemokines in inflammatory sinus diseases during the last years. RESULTS: Discrepancies in research findings may be due to the small available databases today, the use of different techniques for investigation, and the lack of a valuable classification of sinus diseases. Despite this discrepancies, there is evidence that in acute bacterial and viral sinusitis, proinflammatory cytokines play a dominant role in initiating and sustaining the inflammation, which is especially characterized by neutrophil tissue infiltration. In chronic sinusitis IL-3 dominates the cytokine profile, giving support to a variety of inflammatory cells. IL-3 may also contribute to fibrosis and constant thickening of the mucosa leading to an obstruction of the ostiomeatal complex. In most bilateral nasal polyps, tissue eosinophilia is a striking finding which is believed to play a central role in pathogenesis, as it does in asthma. Eosinophilia may be explained by increased migration and prolonged eosinophil survival. Activation and survival of eosinophils in nasal polyps are thought to be regulated by autocrine stimulation by IL-5. Therefore, IL-5 represents the main target for future therapy in nasal polyposis. CONCLUSIONS: Defining cytokine and chemokine patterns in inflammatory sinus diseases leads to a better understanding of immunologic processes in nasal mucosa. Results of cytokine and chemokine research are of paramount interest in developing new therapeutic approaches.

Cell Adhesion Molecules↗
PubMed1999

Effect of prednisolone on cytokine synthesis in nasal polyps.

To investigate steroid effects on eosinophils and their associated cytokines in nasal polyps, we sampled nasal polyp tissue from 20 subjects during routine surgery. Freshley removed polyps were cut into small pieces and incubated in culture medium for 24 h in different concentrations of prednisolone (10(-2)-10(-6) mol/L). Cell viability was assessed by means of trypan dye exclusion of the supernatants. The number of eosinophils was quantified by means of cytocentrifuge smears stained by May-Giemsa-Grunwald stain. The cytokine protein content of interleukin-5 (IL-5), IL-3, and granulocyte-macrophage colony-stimulating factor (GM-CSF) was measured by ELISA technique in supernatants and in homogenates of nasal polyp tissue. Our results revealed a significant reduction in the number of eosinophils and total number of vital cells at concentrations of 10(-3) and 10(-2) mol/L. GM-CSF and IL-5 protein levels were significantly reduced in supernatants and in homogenates after treatment with prednisolone, whereas IL-3 synthesis was not diminished. Corticosteroid effects known to inhibit synthesis of eosinophil-associated cytokines could be measured in terms of a significant decrease in IL-5 and GM-CSF protein level as well as in a decrease in the number of vital cells.

Cell Survival↗
PubMed1999

Mizolastine is effective and well tolerated in long-term treatment of perennial allergic rhinoconjunctivitis. Riperex Study Group.

The aim of this study was to determine the long-term efficacy and safety of mizolastine, a new second-generation antihistamine with European approval, in the treatment of perennial allergic rhinoconjunctivitis. In this study, 141 patients were treated with once-daily mizolastine 10 mg or 15 mg in a 5-month open-label extension of a 1-month double-blind, placebo-controlled trial, which assessed once-daily mizolastine 10 mg. Mizolastine significantly reduced the nasal subscore (sneezing, rhinorrhoea, itch; end-baseline +/- SD, -2.5 +/- 6.3), nasal obstruction (-1.2 +/- 2.6) and rhinoscopy scores (-1.3 +/- 2.6), and improved ocular and total nasal scores after 6 months' treatment. Improvement was maintained for the duration of the study with no loss of drug efficacy. Adverse effects were mild with no specific effects associated with prolonged use. These results clearly demonstrate that mizolastine is effective and well tolerated in the long-term treatment of perennial allergic rhinoconjunctivitis. The significant clinical improvement in nasal blockade may reflect mizolastine's histamine/5-lipoxygenase dual inhibition.

Adult↗
PubMed1999

An update on the pathophysiology of rhinovirus upper respiratory tract infections.

Upper respiratory tract infections are one of the most common infectious diseases in man and are characterized by relatively mild symptoms. However, complications of bacterial super-infection or asthma exacerbations are not seldomly seen. Most upper respiratory tract infections are caused by rhinoviruses. The rhinovirus is a non-enveloped 30 nm RNA-virus with over 100 serotypes that belongs to the Picornaviridae family and only replicates in primates. It is characterized by a single positive stranded genome acting not only as a template for RNA synthesis, but also encoding for a single polypeptide necessary for viral replication. The viral capsid has an icosahedral symmetry and demonstrates deep canyons, with a receptor-binding domain. Rhinoviruses are transmitted mainly via direct- or indirect contact with infected secretions and invade their host by binding to the ICAM-1 receptor on the nasal epithelium. Typical for rhinovirus upper respiratory tract infections are isolated scattered foci of infected epithelium, not showing any striking damage or cytopathic alterations, between large areas of normal epithelium. Today there is still little detailed knowledge on the pathophysiology of common cold, especially on the aspect of cellular migration and defense. A better understanding in mechanisms underlying this cellular response would not only have therapeutical consequences, but may also explain the relationship between viral infectious rhinitis and asthma or atopy. During a rhinovirus infection, a selective neutrophil and monocyte recruitment is observed. In vitro and in vivo data have demonstrated a time-limited, rhinovirus-induced increase in bradykinin, cytokine, chemokine and sICAM-1 concentrations. Epithelial derived proinflammatory cytokines initiate an adhesion cascade and activate T lymphocytes that create a TH1-type cytokine environment within the infected tissue, necessary to eradicate the virus infection. The selective recruitment of neutrophils seems linked to increased concentrations of the chemokine IL-8 and common cold symptoms. It is doubtful that the cytokine-regulated-production of specific neutralising immunoglobulins is necessary for recovery from viral illnesses and presumably only contributes to a late and temporary protection against rhinovirus reinfection. These observations confirm the crucial role that cytokines and mediators play in the pathogenesis of a rhinovirus infection by mediating chemotaxis, transmigration and activation of inflammatory- and immunocompetent cells.

Animals↗
PubMed1998

Histamine--a major role in allergy?

Since its discovery in 1911, histamine has been recognized as a major mediator in allergic reactions and diseases, and today antihistamines remain important agents in the treatment of these conditions. In addition to its known effects on glands, vessels and sensory nerves, recent data have provided further evidence of histamine's proinflammatory actions, which appear to be mediated mainly by H1 receptors. Thus, findings indicate that histamine is a crucial mediator in both the early and late-phase reactions of an allergic response, playing important roles in cytokine release and in the adhesion process. Histamine has been shown to increase the adhesion of leucocytes to the endothelium and to stimulate production of IL-6 and IL-8 by endothelial cells. It also increases TNF alpha-induced IL-6 production and expression of adhesion molecules. These effects can be inhibited by H1 receptor antagonists. First-generation antihistamines, though moderately effective, showed poor selectivity and caused sedation, due to their penetration of the blood-brain barrier, and other troublesome side-effects. Second-generation antihistamines such as ebastine have increased potency due to greater selectivity for histamine receptors, and improved tolerability due to lack of penetration of the blood brain barrier. Recent studies have shown ebastine 10 mg daily to be effective, safe and well tolerated in the treatment of seasonal allergic rhinitis (SAR), with a rapid onset of action, symptom relief comparable to that seen with topical azelastine or oral loratadine 10 mg o.d., cetirizine 10 mg o.d. or terfenadine 60 mg b.i.d., and no significant side-effects. Ebastine therefore offers a new option in the treatment of seasonal allergic rhinitis.

Cell Adhesion↗
PubMed1998

[Cytokine pattern in various forms of sinusitis].

BACKGROUND: Inflammatory sinus diseases include acute sinusitis, chronic purulent sinusitis, and chronic polypoid rhinosinusitis. We investigated the cytokine profile of different types of rhinosinusitis in order to evaluate whether a distinct form of rhinosinusitis is associated with the expression of a specific cytokine profile. METHODS AND PATIENTS: Fresh sinus mucosa obtained during routine surgery from patients with acute sinusitis (n = 10), chronic sinusitis (n = 7), antrochoanal polyp (n = 10), nasal polyps (n = 8), and controls of turbinate mucosa (n = 7) were homogenized. The cytokine protein content (IL-1 beta,IL-3,IL-5,IL-6,IL-8,GM-CSF) of tissue homogenates was measured using ELISA technique. RESULTS: In the group of proinflammatory cytokines, the protein levels measured for interleukin IL-8, a proinflammatory cytokine, IL-1 beta, and IL-6 were elevated in acute sinusitis. In the group of eosinophil-activating cytokines interleukin-3, -5 and granulocyte an makrophage-colony stimulating factor, we measured a significantly elevated protein level of IL-5 in nasal polyp tissue in contrast to significantly elevated IL-3 protein level in chronic sinusitis. CONCLUSIONS: These findings suggest that IL-8 plays a pivotal role in neutrophil-dominated and IL-5 in eosinophil-dominated sinusitis. IL-3 seems to sustain chronic inflammation.

Biopsy↗