Biomedical subjects

L Fjellbirkeland

Publications and source records attributed to L Fjellbirkeland.

10 recordsLinked to original sources

PubMed1998

Non-small-cell lung carcinoma cells invade human bronchial mucosa in vitro.

To study invasion of lung cancer in vitro a novel three-dimensional coculture assay consisting of living human tissues has been developed. Multicellular spheroids initiated from a new large-cell lung carcinoma cell line (GaL23), found to be invasive in immunodeficient mice, were confronted with precultured bronchial fragments derived from mucosal biopsies obtained during routine fiberoptic bronchoscopy. The bronchial fragments consist of a stromal core with scattered fibroblasts covered by a continuous surface epithelium resting on a basal lamina. During the first 2 wk of confrontation, a gradual retraction of the bronchial epithelium with subsequent adhesion of the tumor cells to the underlying basal lamina occurred. The following week, a limited invasion of tumor cells into the bronchial stroma was seen. To facilitate the entrance of tumor cells through the mucosal surface, the surface epithelium was removed prior to coculture by ethylenediaminetetraacetic acid (EDTA) buffer treatment. Upon confrontation, GaL23 cells then rapidly attached to and migrated on the exposed basal lamina and an increasing number of tumor cells was seen in the stroma during the first week of culture. This model offers opportunities for studying mechanisms of lung cancer adhesion, migration, and invasion using human bronchial mucosa as the natural target tissue.

Bronchi↗

PubMed1998

Invasiveness by lacZ transfected non-small-cell lung cancer cells into human bronchial tissues in vitro.

To facilitate the detection of invading tumor cells in a three dimensional coculture assay in vitro, the reporter gene Escherichia coli beta-galactosidase (lacZ), was transfected into a human large-cell lung carcinoma cell line GaL23. Multicellular spheroids initiated from the transfected cell line, GaL23LZ, were confronted with fragments of human bronchial tissue differing in their surface composition. While an intact surface epithelium was found to obstruct both adhesion and invasion of tumor cells, an exposed basal lamina augmented adhesion, migration and invasion of tumor cells into the normal tissue. Tumor cells, migrating on the surface of the bronchial fragments, were found to migrate between the epithelial cells and the basal lamina. Fibroblast covered stromal fragments, derived from resected non-small cell lung cancers, were found to be more edible to the invading tumor cells than subepithelial stromal fragments from normal bronchi. The lacZ transfection made it possible to quantitatively analyze the invasive process. While the transfection neither changed the invasive ability of the tumor cells in vitro or in vivo nor their growth pattern in monolayers, three dimensional growth represented by spheroid morphology and clonogenicity in soft agar was significantly changed. This model offers an in vitro system to study qualitative and quantitative aspects of tumor-host relationships in a complex microenvironment which has several similarities to the in vivo situation.

Bronchi↗

PubMed1996

Nonadhesive stationary organ culture of human bronchial mucosa.

The supply of fresh bronchial tissue from human donors for in vitro culture is limited. Routine fiberoptic bronchoscopy offers a safe and easy procedure for obtaining minor biopsies and we wanted to see if the material provided could be used for organ culture by using a simple liquid overlay technique. Bronchial biopsies were cut into fragments 400-500 microns and kept immersed in a standard serum-supplemented medium for 40 days. An agar base prevented adhesion of the tissue. By light and electron microscopy it was shown that the tissue fragments had a differentiated epithelium at their surface throughout the culture period. An outgrowth of epithelial cells on the scaffold of the exposed stroma, covering the surface of the whole fragment, occurred within the first 5 days of culture. This epithelium was partly ciliated, 2-4 cell layers thick with squamous and cuboidal cells and expressed epithelial markers (cytokeratin and Ber-Ep4). The amount of cilia increased during the first 15 days of culture. The epithelium rested on a neosynthesized basement membrane as visualized by electron microscopy and immunohistochemistry with antibodies directed against collagen IV, laminin, and fibronectin. The central stroma consisted of loose connective tissue with fibroblasts. This simple tissue culture model combines maintenance and neoformation of bronchial epithelium on top of a living natural substrate, thus enabling direct biological studies on clinical biopsy material under perfectly viable conditions.

Adult↗

PubMed1995

[Swimming-induced asthma].

Swimming is said to have low asthmogeneity especially when compared with other physical activities. Four young athletes who participated in heavy swimming exercise are reported as having symptoms of exercise-induced asthma (EIA). Three of them started to develop the symptoms after several years of training and had no former history of asthma. In the fourth, the asthma was diagnosed in childhood but the EIA-symptoms here exacerbated by swimming. All four experienced more symptoms when the air in the swimming pool was warm, or when there was a strong smell of chlorine. Two of the athletes reported having no symptoms when they swam in outdoor pools and had only minor symptoms, or none at all, when they did other formes of physical exercise, including running. In all four their swimming performance was hampered by their respiratory symptoms. Two of the swimmers improved when they inhaled steroids and adrenerg-beta 2 agonists, and continued their swimming carrier. The cases suggest that an irritant may provoke asthma symptoms in susceptible swimmers. Volatile compounds from chlorination of the pools are suspected as possible irritant agents.

Adolescent↗

PubMed1995

[Guidelines for understanding and treating chronic obstructive lung diseases. Institute for Pharmacotherapy].

A group of chest physicians, general practitioners, clinical pharmacologist and pharmacists appointed by the Institute of Pharmacotherapy, University of Oslo has evaluated the present knowledge about treatment of chronic obstructive lung disease. The group discusses today's medical treatment of this rather numerous group of patients. It is stated that, to a high degree, the treatment of these patients lacks proper documentation, and that treatment needs to be tested out on an individual basis. The group proposes a flow chart for this purpose.

Humans↗

PubMed1995

Tumour fragment spheroids from human non-small-cell lung cancer maintained in organ culture.

Biopsy material from 17 human non-small-cell lung carcinomas (NSCLC) was maintained in agar overlay culture as tumour fragment spheroids for 40 days. A practical procedure for the formation of spheroids and organ culture is described. The mechanically dissociated tumour specimens showed a variation in their ability to generate spheroids that was not related to the ploidy or the histological differentiation of the biopsies. Light microscopic observations revealed a heterogeneous spheroid population with a mixture of tumour cells and stromal elements. Most of the histological elements normally found in human NSCLC could be seen in the spheroids. The cellular components in the spheroids varied between highly cellular to sparsely cellular, dominated by stromal elements. The squamous carcinomas were in general found to generate highly cellular spheroids more often than the adenocarcinomas. Spheroids with a different cellular content could be selected in vitro by using a morphometric technique. Diameter measurements showed a large variability in spheroid growth. Most of the spheroids decreased in size although bromodeoxyuridine labelling indicated active cell proliferation in the specimens. Frequent changes of medium did not affect spheroid growth. The culture system presented provides a model for studying the cellular heterogeneity as well as the biological characteristics of tumour tissue from individual patients in vitro.

Aged↗

PubMed1994

The efficacy and tolerability of inhaled salmeterol and individually dose-titrated, sustained-release theophylline in patients with reversible airways disease.

In a double-blind, double-dummy, cross-over, multicentre study, 141 patients with moderate reversible airways disease were randomized to receive either 50 micrograms salmeterol via a metered dose inhaler or individually dose-titrated oral theophylline, both twice daily for a 2-week period. Just over half (n = 77) the patients had received theophylline before, but 64 patients were new to theophylline therapy. Efficacy was based on lung function data and symptom scores. Salmeterol produced significantly higher increase in mean morning peak expiratory flow (PEF) of 161 min-1 (P < 0.001; 95% Confidence Interval (CI); 8-241 min-1) and mean evening PEF of 151 min-1 (p < 0.001; 95% CI; 7-221 min-1) compared with theophylline therapy. Further analysis of the data revealed that the increase in PEF with salmeterol compared with theophylline was highest in a sub-group of patients new to theophylline therapy. Patients on salmeterol had significantly less night-time awakenings than those on theophylline (P = 0.011) and significantly less daytime symptoms (P = 0.017). There was also a significant increase in the number of nights (P = 0.013) and days (P < 0.001) on salmeterol when no additional salbutamol was required compared with theophylline. Theophylline produced a higher incidence of adverse events compared with salmeterol. The results of this study show that inhaled salmeterol is more effective and better tolerated than individually dose-titrated oral theophylline over a 2-week study period in patients with moderate asthma.

Administration, Inhalation↗

PubMed1990

[Methods for administration of anti-asthma inhalation drugs].

Inhalation of aerosols is an established treatment of asthma. There are different delivery systems such as metered-dose inhalers, spacer devices, powder inhalers and nebulizers. The prescribing physician must be familiar with the variety available so that he can choose the device that suits the patient's needs. Teaching and supervising the method of inhalation is important. The metered-dose inhaler is still the most commonly prescribed inhalation system, but powder inhalers are now used by an increasing number of patients.

Administration, Inhalation↗

PubMedDate not supplied

Nonadheshive stationary organ culture of normal human urinary bladder mucosa.

Cold cup biopsies from normal human bladder mucosa were taken at cystoscopy. They were cut into fragments of 300-450 microns and grown in suspension in microwells base coated with agar. Within the first 24 hours of culture the fragments were totally covered by epithelium. After 7 days of culture the fragments had a morphology mimicking normal urothelial mucosa with an epithelium resting on a basement membraned for six weeks in culture. The purpose of this study was to provide a model representative of normal human urothelial mucosa for further studies of various diseases affecting the urinary bladder.

Cell Cycle↗

PubMedDate not supplied

A human in vitro model of bladder tumour cell invasion.

To study invasion of transitional cell cancer three-dimensional coculture assay consisting of living human tissues has been developed. Multicellular spheroids initiated from an invasive human bladder tumour cell line (Hu-1703He) were confronted with precultured fragments derived from normal human bladder mucosa. The fragments consisted of a surface epithelium and a central stroma. An intact epithelium prevented adhesion of the tumour cells to the fragments. By removing the surface epithelium prior to confrontation, tumour cells rapidly adhered to, migrated on and invaded the bladder fragments. This process was demonstrated by an inverted confocal laser scanning microscope on live tissue pre-incubated with fluorescent dyes. The coculture model enables the study of factors regulating different steps of tumour invasion in human bladder.

Biopsy↗