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Biomedical subjects

E Larsson

Publications and source records attributed to E Larsson.

At least 181 records · Page 10Linked to original sources
PubMed1983

Formation and growth of multicellular spheroids of human origin.

Different types of human cells which normally grow as monolayers or suspension cultures were tested for their capacity to form and grow as spheroids. Sixteen out of the 27 tested tumour cell lines formed spheroids. Nearly all of these spheroids also grew. With only two exceptions the doubling times were longer when the tumour cells grew as spheroids than when they grew in conventional mass culture. Eleven out of 13 tested human non-tumour cells formed small spheroids but of these only the spheroids of lymphoid origin could grow. These lymphoid cells grew faster when aggregated to spheroids than when in single-cell suspension culture. None of the other non-tumour cells, which normally grew as monolayers, could grow as spheroids. The normally monolayer-cultured tumour cells formed symmetrical spheroids with smooth surfaces while the normally suspension-cultured cells formed irregular spheroids with rough surfaces. All large spheroids had a necrotic centre surrounded by a shell of viable cells. The thickness of the viable cell layer varied depending on cell type. The shape and organization of cells within the spheroids also varied largely. The results show that many types of human cells can be cultured as spheroids and that a wide spectrum of morphological appearances and growth rates can be obtained.

Cell Aggregation↗
PubMed1983

T-lymphocyte subsets and HLA-DR-expressing cells in rejected human kidney grafts.

This communication describes an immunohistochemical analysis of rejected human renal allografts. T-lymphocyte subsets were identified in frozen tissue sections, by Leu 1 (anti-'pan' T lymphocytes), Leu 2a (anti-'cytotoxic/suppressor' T cells), and Leu 3a (anti-'helper/inducer' T cells) monoclonal antibodies. In addition, HLA-DR-positive cells were identified by simultaneous labelling with heterologous anti-HLA-DR antibodies. T cells dominated the cellular infiltrates in acute cellular rejection. Leu-3a-positive cells were more numerous than Leu-2a-positive cells. The Leu-3a-positive cells usually appeared in clusters, whereas the Leu-2a-positive cells appeared scattered in the tissue. HLA-DR-positive non-T cells were found within clusters of T 'helper/inducer' cells. The cell pattern shares many features with the findings in delayed-type hypersensitivity reactions.

Antibodies, Monoclonal↗
PubMed1983

The effect of the supra-alveolar soft tissue on the relapse of orthodontic treatment.

Orthodontic closure in cases of aplasia as also in patients with spaces of other genesis is often associated with problems of relapse. In this study ten patients were treated orthodontically in order to close unacceptable interdental spaces. Five patients had paired aplasia. The remaining five patients had interdental spaces of different genesis. Supra-crestal connective tissue fibres were surgically removed in all patients but only on one side of the jaw in the children with paired aplasia. The non-operated side of these children served as a control side. The stability of the orthodontic treatment was acceptable. No definite difference between the operated and the control side was recorded. The histological analysis of the removed tissue did not reveal anything unexpected but a rich infiltration of inflammatory cells. It is suggested that inflammation might aid the reorganization of the connective tissues in this area.

Anodontia↗
PubMed1983

Malocclusions in a juvenile medieval skull material.

From a mostly medieval skull material--the "Schreiner collections" in Oslo--juvenile crania were selected as follows: Group A: Crania with complete and intact primary dentition. n = 20. Group B: Crania with early mixed dentition. Incisors only erupted or under eruption. n = 47. Group C: Crania with late mixed dentition. n = 14. The author recorded visually: Sagittal and transversal dental relation, frontal dental contact, anterior cross-bite, rotation and crowding. There was good basal stability. Sagittally 1 moderately postnormal dentition was recorded, transversally there were no anomalies. Slight anterior cross-bite was recorded in 1 case, anterior cross-bite of one and two lateral incisors respectively in 2 others, and tête-à-tête contact in 3 cases. Crowding was recorded in 6 cases, in one of them being general, in the others located solely in the mandibular incisor segment. Broken contact and more or less pronounced rotation occurred in these dentitions. Rotation was also recorded in 2 other cases. The prevalence of malocclusions of the type that can be related to continuing finger-sucking or sucking of dummylike objects was very low in this material. This observation prompted the author to discuss a hypothesis concerning the aetiology of dummy- and finger-sucking habits.

Adolescent↗
PubMed1983

Prevalence of crossbite among children with prolonged dummy- and finger-sucking habit.

The prevalence of crossbite was determined among 252 children with prolonged finger-sucking habit and 31 children with prolonged dummy-sucking habit. The prevalence of crossbite in both groups was within the values regarded in the literature as normal for the age group. An analysis was also made of 289 patients registered for orthodontic treatment. An elevated prevalence of crossbite was not recorded, either, among children with dummy- or finger-sucking habit in this group of patients.

Child↗
PubMed1983

Thigh muscle strength in below-knee amputees.

The aim of this investigation has been to study the magnitude of the reduction of thigh muscle strength of below-knee amputees and to correlate the strength to the degree of atrophy and to the clinical function. Thirty-two below-knee amputees participated in examinations of the isometric and isokinetic knee extension and flexion strength using an isokinetic dynamometer (Cybex II). The atrophy was evaluated by measuring the mean muscle fibre area on muscle biopsies of the vastus lateralis and the cross-sectional area of the quadriceps and hamstring muscles measured with computed tomography. The isometric and isokinetic knee extension and flexion strength in the amputated leg with and without prosthesis was significantly lower than the strength in the non-amputated leg (p less than 0.01). Knee extension strength was significantly correlated to the mean muscle fibre area of the vastus lateralis. There was no correlation between strength and the cross-sectional area of the quadriceps muscles. There was, however, a significant correlation between the side differences (amputated leg versus non-amputated leg) in isometric knee extension and flexion strength and the side differences in cross-sectional areas. The reduction in isometric and isokinetic knee extension and flexion strength in the amputated leg both with and without prosthesis compared with the non-amputated leg was larger than the reduction in cross-sectional areas of the quadriceps and hamstring muscles and in muscle fibre areas of the vastus lateralis. This indicates that besides muscle atrophy changes in motor unit recruitment pattern may be of importance for the reduction in muscle strength. Isometric and isokinetic knee extension and flexion strength values in the amputated leg with prosthesis were significantly correlated to step length, maximal walking speed and circumference of the thigh. These results indicate that below-knee amputees with a better preserved thigh muscle strength have a good walking capacity.

Adult↗
PubMed1982

Neuron specific enolase: a marker for differential diagnosis of neuroblastoma and Wilms' tumor.

Thirteen human neuroblastoma and six Wilms' tumor biopsies have been analyzed for neuron specific enolase (NSE). THe relative activity of NSE in the neuroblastomas (including ganglioneuroblastoma and ganglioneuroma) ranged from 28% to 62.5% of total enolase activity. The corresponding figures for the Wilms' tumors were 1% to 4.5%. It appears that NSE can serve as a biochemical marker for neuroblastoma and be useful in the differential diagnosis of neuroblastoma and Wilms' tumor.

Child↗
PubMed1982

Establishment and characterization of two neoplastic cell lines (U-1285 and U-1568) derived from small cell carcinoma of the lung.

Two human cell lines have been established in vitro from patients with small cell carcinoma of the lung (SCC). The U-1285 line was derived from the classical small cell type of SCC while the U-1568 originated from a larger cell variant. The cell lines grow as suspension cultures and have been passaged continuously in vitro for 3 years (U-1285) and 2 years (U-1568), respectively. The malignant nature of the lines is suggested by their infinite growth potential, their capacity to form colonies in agarose and their aneuploidy. Both cell lines contain cytoplasmic electron dense particles indistinguishable from classical neurosecretory granules but only in U-1568 has hormone production (human chorion gonadotropin (alpha-HCG)) been proven. The U-1568 line produces carcino-embryonic antigen (CEA) while both U-1285 and U-1568 produce alpha-feto-protein (AFP). Chromosome analysis reveal aneuploidy of both lines. Among structural aberrations, involvement of chromosome 14 in U-1285 and chromosomes 1, 7 and 12 in U-1568 is interesting since alterations of these chromosomes have been described previously in other malignant conditions.

Carcinoma, Small Cell↗
PubMed1982

Polyacrylamide microbeads with entrapped protein A from S. aureus for cell separation.

A technique was developed for the identification and separation of cells according to their surface antigenic markers, based on immobilization of protein A by entrapment in polyacrylamide microbeads. This method is further development of the previous techniques with SpA-containing S. aureus bacteria, but has the advantage of having less unspecific binding to the cells. We show that this technique might be a useful tool for the separation of cells, exemplified by separation of cells on Petri dishes coated with a monolayer of SpA-microbeads. The viability of separated cells was unaffected and adherent cells were easily removed by trypsin.

Acrylic Resins↗
PubMed1982

Clinical crown length of incisors in 13-year-old boys and girls with different malocclusions.

The clinical crown length of incisors in 13-year-old children with different malocclusions was compared. The children were classified as follows: II1 Class II, division 1 cases with deep overbite. II2 Class II, division 2 cases. III Class III cases with complete or partial frontal inversion. IV Cases with aplasia of the upper laterals. The groups were subdivided by sex and recruitment was continued until each group contained 30 boys and 30 girls. The results are shown in Table 2. Good agreement was found between boys and girls with respect to the results of measurement of the different variables, comparison of the different malocclusion groups showed that the clinical crown length was greater in groups II1 and III than in groups II2 and IV. Comparison of groups II1 and III showed a somewhat greater crown length of the lower incisors in the prenormal children. The findings are discussed in relation to the following three hypotheses: 1. Proclined incisors have a longer clinical crown than upright incisors. 2. The incisors overerupt in children with large lower facial height, leading to an increased clinical crown length. 3. Local gingival conditions influence the clinical crown length.

Adolescent↗
PubMed1981

Morphological and microbiological signs of endogenous C-virus in human oocytes.

Human oocytes in different stages of maturation were obtained by follicular aspiration from women given Clomovid and Gonadex. Particles similar to type-C virus were observed in three out of 16 oocytes. The particles were irregularly distributed along the oocyte membrane. They were seen both in a state of budding and lying free in the perivitelline space. Reverse transcriptase activity was detected in three out of nine samples of follicular fluid obtained from women other than those donating the oocytes. The supernatants from bat lung cells and dog thymus cells cultivated with oocytes or follicular fluids were tested for reverse transcriptase. An increased activity was observed only transiently in one case. It is assumed that these findings indicate the expression of endogenous retroviruses in human oocytes.

Body Fluids↗
PubMed1981

Phenotypic changes of human neuroblastoma cells in culture induced by 12-O-tetradecanoyl-phorbol-13-acetate.

SK-N-SH and SH-SY5Y human neuroblastoma cells treated by 12-)-tetradecanoyl-phorbol-13-acetate(TPA) express morphological and biochemical changes, which indicate that differentiation towards more mature cells has occurred. The most prominent morphological changes were the development in 40-60% of the cells of cell-surface projections longer than 50 micrometers and cytoplasmic neurosecretory granules demonstrated by electron microscopy. At the biochemical level, TPA induced a two-fold increase in the relative activity of neuron-specific enolase and 30- to 40-fold increase in noradrenaline and adrenaline concentrations. A decrease in proliferation rate of TPA-treated cells was observed. The biological effects of TPA were slightly potentiated by nerve growth factor.

Cell Division↗
PubMed1981

Neuron-specific enolase in relation to differentiation in human neuroblastoma.

The presence of the two forms of enolase, neuron-specific enolase (NSE) and non-neuronal enolase (NNE), have been examined in biopsy material of human neuroblastoma, ganglioneuroblastoma, ganglioneuroma and cultured neuroblastoma cells, after separation with ion exchange chromatography. The enolase activities were inhibited in the presence of NaCl but remained active in KCl, which were used in the chromatographic step. The relative NSE levels in the neuroblastoma tissues were found to be lower than in the histopathologically more differentiated forms of the tumour, i.e. ganglioneuroblastoma and ganglioneuroma. The human neuroblastoma in vitro cell lines SK-N-SH, SH-SY5Y, SK-N-MC and IMR-32 contained considerably lower relative levels of NSE compared to the levels in the neuroblastoma biopsies. After treatment of the cultured cells with nerve growth factor or dibutyryl-cAMP some cells showed morphological differentiation and concomitantly an increase in the NSE levels. The results indicate that NSE might be useful as a marker for differentiation in human neuroblastoma.

Biopsy↗