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B Engström

Publications and source records attributed to B Engström.

132 records · Page 8Linked to original sources
PubMedDate not supplied

Membrane specializations in the human organ of Corti.

The human organ of Corti was investigated with the freeze fracturing technique with the purpose of analysing membrane specializations. Tight junctions were found on hair cells as well as on supporting cells. Inner and outer hair cells were coupled to the supporting cells by rather extensive tight junctions. The tight junctions between the Deiter's cells were comparable to those of the hair cells, while the tight junctions between the Hensen's cells were considerably less extensive. Gap junctions were present coupling all supporting elements in the organ of Corti, small ones preferably in the apical regions of the cells and large ones in the basal region.

Freeze Fracturing↗
PubMedDate not supplied

The olfactory and respiratory epithelium in rhesus and squirrel monkeys studied with freeze-fracture technique.

Olfactory and respiratory epithelia was prepared for thin-section and freeze-fracture replicas, and were investigated using electron microscopy. Three cell types were identified in the olfactory epithelium: olfactory receptor neurons (ORN), sustentacular cells (SC) and basal cells (BC); and respiratory epithelial cells (RC) in the surrounding mucosa. ORN and RC were provided with kinocilia. The cilia displayed their characteristic 5-7 rows of proximally situated 'necklaces', seen in freeze-fracture replicas. ORN and SC as well as RC were connected with tight junctions classified as being 'tight', whereas the RC displayed intermediate junctions. No nexuses (gap junctions) were found. It is concluded that the monkey olfactory/respiratory epithelium exhibit the same characteristics as seen in other vertebrates when using thin section/freeze-fracture technique.

Animals↗
PubMedDate not supplied

Preservation of the human cochlea.

Human cochleas processed with a varying interval between death and initial fixation were examined by transmission and scanning electron microscopy. The specimens were fixed by paraformaldehyde-glutaraldehyde fixatives in buffer. Cochleas fixed less than two hours postmortem showed excellent morphology in general. With increasing time lag between death and fixation the results became more variable. In some specimens fixed up to six hours postmortem, however, the morphology still was well preserved, but as the interval increased, a greater variability was introduced. The conclusion is that specimens fixed up to six hours postmortem can show excellent electron microscopic morphology. Limited information can be obtained up to 12 hours postmortem, after which the results tend to be unreliable.

Adult↗
PubMedDate not supplied

Detection of specific antibodies directed against a consistently expressed surface antigen of Mycoplasma gallisepticum using a monoclonal blocking enzyme-linked immunosorbent assay.

Sera from 14 groups of chickens inoculated with different laboratory and field strains of Mycoplasma gallisepticum (MG) were used to compare the diagnostic potential of the hemagglutination-inhibition (HI) test and a recently developed monoclonal blocking enzyme-linked immunosorbent assay (ELISA). HI was performed with strain A5969, commonly used as hemagglutinating antigen, and it could detect 62.7% of the inoculated chickens as positive. Of all sera, 83% proved to be positive when examined with the blocking ELISA. The difference between the sensitivities of the two methods was due to group-specific insensitivity of the HI test. None of the sera from groups inoculated with strains K 1501, K 1503, K 503, or K 703 and only half of the sera from groups inoculated with K 1453 or 236C could inhibit the activity of the A5969 hemagglutinating antigen, indicating antigenic differences between these challenge strains and the diagnostic strain. ELISA detected MG-specific antibodies in every group of sera, although inoculation with variant strains K 503 or K 703 resulted in lower level of antibody production than inoculation with other strains. The monoclonal blocking ELISA can be useful in the serological diagnosis of MG infections, because it is based on a consistently expressed, specific region of MG.

Animals↗