Islet cell and 64K autoantibodies are associated with plasma IgG in newly diagnosed insulin-dependent diabetic children

There is a high prevalence of islet cell antibodies (ICA) and autoantibodies detected against an islet cell protein of Mr 64,000 at the time of clinical diagnosis of insulin-dependent diabetes (IDDM). In view of the biphasic immune response after antigen presentation, the purpose of this study was to determine the presence of ICA and antibodies against the 64,000 islet antigen after separation of IgM from IgG to prevent interference between the two antibody classes. Plasma samples from 10 newly diagnosed IDDM children and 10 healthy controls were precipitated with polyethylene glycol (PEG), and the crude Ig was subjected to Sephacryl S-300 chromatography to separate IgM and IgG. ICA determined by indirect immunofluorescence on frozen sections of human pancreas showed reduced background immunofluorescence intensity in the purified fractions compared with crude plasma. The number of ICA-positive samples among the IDDM patients increased from 7/10 in plasma to 9/10 in the IgG fraction. There was an increase in the ICA titer in 6/9 of the positive samples. All purified IgM samples were ICA negative. Immunoprecipitation experiments by using Nonidet P-40 detergent lysates of [35S]methionine-labeled neonatal rat islets demonstrated that the 64,000 autoantibodies were in the IgG fraction. We found 7/10 IDDM samples to be positive, whereas all controls were negative. The background in the autoradiographic analysis was markedly reduced in the IgG fractions compared with immunoprecipitates with crude or PEG-purified plasma and the IgM fraction. ICA titers did not correlate to the ability of the IgG fraction to precipitate the 64,000 autoantigen. It is concluded that both the ICA and 64,000 autoantibodies are primarily of the IgG class at the time of clinical onset of IDDM, and that purification of IgG from human IDDM plasma facilitates the detection of the rat islet cell 64,000 antigen.     

Glycerol models of the ciliated epithelium of bronchial mucosa and their use in the diagnosis of chronic nonspecific lung diseases

The method of extraction of ciliated epithelium from biopsy samples of human bronchial mucosa with glycerol is suggested. Permeabilized cilia of glycerol-extracted cells can be easily reactivated by exogenous ATP. This method was used for the study of ciliary dyskinesia in patients with chronic lung diseases. It was shown that in patients with Kartagener's syndrome neither freshly-isolated, nor glycerol-extracted ATP-treated cilia were motile. On the other hand, in some patients with bronchial asthma ATP reactivated glycerol-extracted cilia, while cilia of freshly-isolated cells remained immotile. The study shows that glycerol permeabilization and reactivation by ATP can be used for the analysis of cilial contractile apparatus in patients with chronic lung disease.     

Morphofunctional features of the development of the thyroid gland of Dicrostonyx torquatus during the drop in population stage

By means of the histostereometrical method, peculiarities of the thyroid gland formation have been studied in the lemming (Dicrostonyx torquatus) fetuses and newborns at the stage of the population quantity drop, as well specificity of the organ's morphofunctional state during the postnatal period. On the 14th prenatal day the thyroid gland already has the follicular structure. Up to the 19th day progressive follicular growth, accumulation of colloid and increase of its density occur. On the 19th-20th days, as well as in newborn animals, there are certain signs, demonstrating as essential activation of the thyroid gland function. In the newborn animals cavities of the completely formed follicles are devastated. During the postnatal period again growth of follicles, accumulation of colloid are observed, signs of hypersecretion of the hypophysis appear.     

Human Long-Latency Auditory Evoked Potentials during Radial Motion of the Sound Source

Human long-latency auditory evoked potentials were studied during simulation with variable-amplitude pulse sequences from a sound source moving to and from the subject. The N1 peak parameters were shown to depend on an accurate estimate of the direction of the change in the distance to the sound source. Differences in the processing of signals that simulated the approaching and/or distancing of the sound source were found in the N1 and P2 component parameters of on- and off-responses as was a more pronounced long negative potential shift in the evoked response to the approaching source as compared to the distancing source.     

Amine oxidase in unicellular microorganismsMethanosarcina barkeri andTetrahymena pyriformis

A comparison has been performed of catalytic properties of unicellular microorganism amine oxidases (AO) from two new enzyme sources, the bacteriumMethanosarcina barkeri and the infusoriaTetrahymena pyriformis. It was shown that the both studied AO deaminate tyramine, serotonin, and benzylamine, but do not deaminate histamine. The AO fromMethanosarcina barkeri catalyzes deamination of all three substrates at an identical rate, while the rate of tyramine deamination under effect of AO fromTetrahymena pyriformis is one order higher than the rate of serotonin deamination, and about two orders higher than the rate of benzylamine deamination. Based on the data of the substrate-inhibitor analysis, a suggestion was made about the existence of one center for the substrate binding in the AO of the studied bacterium, while several centers in the AO of the studied infusoria.     

Modeling Tetrahymena thermophila growth and protease production

Oxygen concentrations stimulated growth (maximum number of cells) and protease secretion by Tetrahymena thermophila. Agitation and aeration conditions for growth and protease secretion were optimised by a central composite design. The best optimised combination was a stirrer speed of 338 rpm and an aeration of 1 vvm. Journal of Industrial Microbiology & Biotechnology (2000) 25, 58–61. Received 24 September 1999/ Accepted in revised form 06 March 2000