Biomedical subjects
Publications and source records attributed to E Larsson.
A New cell line, U-706, established from an uncommon human glioma (possibly giant-cell glioblastoma) is reported in this communication. The tumor gave rise to two permanent sublines, one attached (U-706M) and one non-attached (U-706S) cell line. The growth characteristics, chromosome banding pattern, electronmicroscopic picture and cell surface characteristics of the two sublines are described.
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Mycoplasma contamination of cultured cells may cause considerable interference with their behaviour and metabolism. Whether or not mycoplasma are actually taken up by cells in vitro has long been a matter of dispute. In the present study mycoplasma were shown to phagocytosed by feline lung fibroblasts and to end up in the lysosomal vacuome of the cells, where the organisms were only partially degraded by the hydrolytic enzymes leading to a rapid (within a few days) accumulation of secondary lysosomes of the residual body variety. It is thus obvious that studies on the structure and function of the lysosomal vacuome in cultured cells are possible only if precautions are taken to avoid that the cultures become contaminated by mycoplasma.
A factor present in the supernatant of an established human glioma cell line U-251 MG strongly suppresses feline sarcoma virus (FeSV) focus forming activity on feline embryo fibroblasts. The factor was identified as mycoplasma arginini. The enriched mycoplasma fraction had no cytpathogenic effect on the glioma cells or on the embryonic feline indicator cells. An antiserum prepared against this strain of mycoplasma abolished the inhibition. The exact mechanism is not known but arginine depletion in the medium seems to be an important factor.
Continuing finger-sucking often leads to an anterior open bite. The object of the present study was to attempt to illustrate whether this open bite is caused by an arrested eruption of incisors or primarily by inhibited growth of the alveolar processes. A comparison is made between 9-, 11- and 13-year-old children with continuing finger-sucking habits or who ceased finger-sucking only after 8 years of age, and children of the same ages without sucking habits in respect of the clinical crown length of central and lateral incisors in the upper and lower jaws. In all measurements the clinical crown length among children in the finger-sucking groups was greater than among children in the control groups (Table 1). The anterior open bite of the finger-suckers was therefore probably not caused by arrested eruption of incisors but rather by inhibited vertical growth of the anterior part of the alveolar processes.
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 3 out of 16 oocytes. The particle were irregularily distributed along the oocyte membrane. They were seen both in a state of budding and as free lying in the perivitelline space. Reverse transcriptase activity was detected in 3 out of 9 samples of follicular fluid obtained from women other than those yielding the oocytes. It is assumed that these findings indicate the expression of endogeneous retroviruses in human oocytes.
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This is the first of three reports in a study of the effect of the supra- alveolar soft tissues on orthodontic relapse. A surgical method is presented, the object of which is to remove most of the interdental soft tissues without permanent damage to the gingiva or the other parts of the periodontium. A marginal incision is made buccally and lingually in the gingival sulcus in the area concerned. The edge of the wound is folded away from the teeth with a raspatory (Fig, 2). The portion of the papillae remaining between the teeth is excised (Fig 3). The edges of the wound are approximated with sutures placed interdentally (Fig 4). The surgical wound heals with complete regeneration of the interdental papillae (Figs. 6 and 9).
Dentinogenesis imperfecta is a hereditary condition characterized by disturbance in tooth formation. The colour of the teeth vary from opalescent greyish-blue to an amber-like colour on the teeth with splitting of the enamel. On the roentgenogram the marked obliteration of the pulp chambers is a characteristic feature. This case report describe a 13-year-old boy with dentinogenesis imperfecta. High caries activity resulted in extensive caries on the first permanent molars. The boy had to be treated orthodontically to create acceptable occlusion. The treatment was carried out with fixed appliance and started after extraction of the four first permanent molars. No observable injury was recorded during the treatment.
Fatal progressive vaccinia developed in two infants, a girl and a boy, vaccinated at the age of 2 months. Immunodeficiencies comprised both humoral and cell-mediated immunity. In the girl low levels of immunoglobulins and a defect function of lymphocytes was demonstrated. The boy had hypogammaglobulinemia and lack of T-lymphocytes. There was a marked hypoplasia of thymus and lymphoid organs in both infants. Both infants had the haplotype A3, B8 and in the boy a crossing over had taken place within the HLA region. No effect was achieved with antivaccinia immunoglobulin and concomitant antiviral therapy (thiosemicarbazone, adenine arabinoside). Interferon therapy gave no clinical improvement, nor did transfer factor.
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Plastic dishes were coated with an agarose layer. The layer was modified by covalently binding proteins to it, using the CNBr-method. Cells were seeded on the dishes and the number of attached cells was evaluated. The specificity of the attachment was demonstrated by showing that cells, carrying specific membrane-bound immunoglobulins, attached only to the corresponding anti-immunoglobulins. This indicated that the method could be used for cell sorting. The attachment of cells to proteins was influenced by the amount of bound protein, incubation time, temperature and the degree of trypsinization. Most attached cells were viable for several days and when dying they detached. Detailed morphological and cytochemical analyses of the dynamics of attachment and cytoplasmic spreading on the chemically well-defined surfaces were possible using the new method.
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The first reported case of abdominal aortic aneurysm complicating homocystinuria is presented. The clinical features and microscopic findings were identical to those of an atherosclerotic aneurysm. Homocystinuria may stimulate Marfan's syndrome but can be differentiated by the cyanide-nitroprusside screening test for homocystine in urine. Although homocystinuria is accompanied by an increased risk of thrombosis, surgical treatment of complicating diseases should not be avoided. Pyridoxine treatment is recommended.
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