Biomedical subjects
Publications and source records attributed to Z Lodin.
Contemporary aspects of cerebrospinal fluid analysis are discussed, including the relationship to neuro-infective, autoimmune and other neurological diseases. The actual state of cerebrospinal fluid microbiological and cytological investigation and analysis of cerebrospinal fluid protein fractions are described in detail.
Presept (containing sodium dichloroisocyanurate as active component) was shown to be an excellent analytical reagent superior to classical Chloramine T and Chloramine B. Potentiometric titration of potassium ferrocyanide was found to be most suitable for estimation of chlorine content in Presept solutions. The presence of serum albumin can block or reverse the oxidation of ferrocyanide completely, whereas that of a detergent is of little importance. The content of available chlorine in various Presept tablets was found to be as a rule slightly higher than that guaranteed by the dilution rules of Johnson & Johnson. Presept solutions are remarkably stable, paradoxically the concentration of available chlorine in open vessels remains higher than in perfectly closed vessels.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
A lower level of BEI was demonstrated in duodenal ulcer patients in both acute and chronic cases (P less than 0.01). Treatment of patients with PI increases BEI up to values found in healthy subjects, in accordance with our previous findings (17). The basal level of BOI in ulcer patients did not differ from that in healthy subjects. A transient increase of BOI was recorded during the first phase after PI application, however, BOI decreased to basal levels at the end of the therapy (P less than 0.05). The basal PPI level was higher in both groups, primarily in acute ulcer patients (P less than 0.01). During the treatment with PI the PPI level slightly increased. Mathematical correlation between BEI and BOI, and BEI and PPI revealed a significant negative correlation (P less than 0.001). However, this correlation was found in healthy subjects only, indicating that healthy subjects with a high BEI level have lower BOI and PPI values and this relation depends on BEI. This dependence is absent in ulcer patients.
A lower level of beta-endorphin (BE) was demonstrated in patients with both acute and chronic duodenal ulcer (P less than 0.01), while the basal level of bombesin (BO) in such patients did not differ from that in healthy subjects. The basal pancreatic polypeptide (PP) level was higher in both groups of patients, primarily in those with acute ulcer (P less than 0.01). A significantly negative correlation (P less than 0.001) between the levels of BE and BO, and between those of BE and PP, was found in healthy subjects. Similar interrelation was absent in ulcer patients.
Single cell suspensions prepared from adult mouse brains were tested for the presence of pluripotential haemopoietic stem cells (colony-forming units, CFU) by transfer into an irradiated recipient and enumeration of the CFU in the recipient's spleen. In contrast to the findings of others (Bartlett, 1982), we did not detect CFU after injection of brain cell suspensions, although they were detectable after inoculation with bone marrow cells. The number of CFU in recipients after transfer of increasing numbers of brain cells was the same as that detected in the irradiated controls which had not received any transferred cells. Finally, cells from the brain, in contrast to bone marrow cells, were not able to protect recipient animals from the effects of lethal irradiation.
Embryonic mouse brain cells were rotated for 120 min and cellular adhesivity was tested under normal conditions and in the presence of substances which change the membrane properties. A marked decrease of cellular adhesivity (but not complete inhibition) was recorded in the presence of anionic detergents, while fixation of cells caused only non-significant inhibition Colchicine (1 mumol/l) and vinblastine (10 micrograms/ml) did not significantly affect the adhesivity. Increased external K+ (10 mumol/l) and ouabain (10 mmol/l) were also without a significant effect, however, EGTA (0.1 and 0.01 mmol/l) inhibited the adhesivity significantly. 2,3 dimethyl maleinic anhydride (DMA) which removes a part of the positive charge, caused a slight decrease of adhesivity. It is suggested that the primary adhesivity of brain cells is dependent upon the structural integrity of surface membranes, while the organization of the tubular system does not play a significant role. Isotonic concentration of monovalent cations is optimal for adhesivity and an increased concentration of external K+ or ouabain did not affect adhesivity significantly.
With the help of a previously described experimental arrangement the influence of increased external concentration of Ca2+, La3+, PVP and urea was tested on the initial stages of brain cell adhesivity and its kinetics. Urea, an inhibitor of hydrogen bonds, significantly inhibited the adhesivity of the treated cells. PVP significantly increased cell adhesivity. The adhesivity was enhanced and speeded up by increased concentrations of Ca2+ and La3+. It is evident that the membrane surface potential, zeta potential and formation of H+ bonds and bridges are highly important for cellular adhesivity. EM control of freshly dissociated cells disclosed that a part of the cells had been damaged. According to the ultrastructural organisation, the surface membrane is damaged to a small or greater extent. Intercellular contacts were formed in vitro either between non damaged surfaces of membranes, or between fragments of membranes, or contacts were mediated by membrane debris. Because cellular debris disappeared during rotation from single adhesive complexes, it is probable, that disrupted membranes are used for restoration of membranes, or serve as a metabolic substrates, or are catabolized.
Explore the source record for details and available documents.
The initial level of PL-beta-ED-ir was significantly lowered in a group of 14 patients with gastroduodenal ulcer disease as compared with healthy volunteers (P less than 0.05). Immediately after i.m. administration of 20 mg gastrozepin (G) the PL-beta-ED-ir level increased but not significantly. Given orally over two weeks, G (50 mg/day) led to a more than doubling of the initial level (P less than 0.05). Controls showed no significant changes. A further meaningful change represented the time relationship of PL-beta-ED-ir during 5-hour observation to i.m. administration of 20 mg G before the start and after the end of the 2-week oral therapy. The placebo character of the above findings rules out the absence of any deviations of PL-beta-ED-ir in the diseased and healthy group after i.m. injection of saline. The study deals with the findings in relation to the pathophysiology of ulcer disease, and with a potential interference of G in the interrelation of the cholinergic and endogenous opiate systems.
Changes in the size and dry mass of glioma C-6 intact cells in culture were investigated for 35-50 min at 5 min intervals by means of vital cytointerferometry. Rhythmic variations in the size, dry mass and protein concentration were thereby revealed in glioma cells. These variations fall into the category of circahoralian ones. While considerable variations in the cell area and dry mass were observed, changes in protein concentration were less pronounced. Addition of dibutyryl cylic AMP (db-cAMP), in a concentration of 10(-3) mol/l to the cultivation medium, produced no effect on the rhythm of the above parameters in glioma C-6 cells.
Brain cells from 16 to 18-day-old mice embryos were dissociated by mild trypsinization and rotated for 120 min. The area and density of of the adhesive complexes formed were registered using the method described previously. The adhesiveness of dissociated embryonic brain cells (measured during the 120 min of rotation) was diminished in the presence of inhibitors of protein synthesis (puromycin, cycloheximide and inhibition of mRNA synthesis actinomycin D). The inhibition was, however, not distinct, because 1 microgram/ml of cycloheximide and actinomycin was without any significant effect, and the degree of inhibition evoked by 10 micrograms/ml and 25 micrograms/ml of puromycin bordered on significance. However, protein synthesis inhibitors in long-term aggregation experiments had a pronounced inhibitory effect and/or induced destruction of the aggregates. Metabolic inhibitors (KCN and NaN3) caused an inhibition at the lowest level of significance (p less than 0.05) 10(-3) mol/l KCN reduced the final adhesive product significantly. Cells rotated at room temperature and at +5 degrees C adhere to the same extent as in control experiments (37 degrees C). The adhesion was significantly inhibited at +60 degrees C and also after freezing at -80 degrees C with subsequent thawing. The adhesion of cells exposed for 30 min to between +80 degrees C and 100 degrees C was completely abolished. The process of embryonic brain cell adhesion requires a low energy supply, and is relatively independent of biosynthetic processes and of temperature changes between +5 degrees C and +50 degrees C.
An antigen non-specific suppressor factor (SF4) produced by a permanent mouse T cell line inhibits the mitogen- and antigen-induced proliferation of cells in vitro. The suppression of immune response is not restricted by interspecies barrier. Administration of the SF4 factor in vivo had a significant suppressive effect on the induction and manifestation of experimental allergic encephalomyelitis (EAE) in rats. Rats treated with SF4 factor, the first dose being injected on the day of EAE induction, had no clinical manifestations or developed only mild clinical signs of EAE. Administration of the SF4 starting on day 4 after EAE induction, when the immune system had been activated, depressed the course of EAE. The results obtained in this model autoimmune disease indicate that the described suppressor factor is active in vivo and that it may be used to depress the autoaggressive immune reactions.
Explore the source record for details and available documents.
Single stages of histiotypic formation from dissociated embryonic brain cells are described. The first stage, i.e. primary adhesion, is a phenomenon depending mainly on physicochemical features of the adhesive system. The composition of the membrane glycoprotein coat was studied during membrane regeneration and formation of cellular contacts. At the beginning single terminal sugar components and negative sialic acid residues are distributed non-homogeneously over the membrane according to the ligation of lectins. During the formation of cellular contacts this non-homogeneity progressively disappears, the thickness of the layer is reduced, however, the density of single markers increases. The highest increase of both density and layer thickness during the phase of membranes reparation occurs when the negative surface groups are labelled with cationized ferritin. The sorting out process was studied in mixed cultures as a stage of final specific recognition. It is assumed that the reaggregation of cells is a multistep process depending on maturation of the glycoprotein coat, characterized by multiple cellular adhesion and deadhesion, completed by specific recognition and fixation of recognized cells.
Brain cells from 16 to 18-day-old mice embryos were dissociated by mild trypsinization and sieving. Immediately after dissociation the cells were preincubated in a PBS solution at -6 to +54 degrees C for 3 and 20 min. After this preincubation cells were rotated for 60 min at 37 degrees C in the PBS solution. Cellular adhesivity was estimated during this time period and EM pictures of organized in vitro aggregates after 24-28 h were taken. In a separate series of experiments, freshly dissociated were treated with DNAase before the rotation procedure. Preincubation in a cold or a warm medium did not alter the inhibition of cellular adhesivity significantly. Distinct inhibition of cellular adhesion was observed in cells preincubated above 53 degrees C. Adhesion was also inhibited below -5 degrees C, however, this effect was mainly dependent on the rate of freezing and thawing. Digestion of dissociated cells with DNAase (20 micrograms/ml) decreased cell adhesion. At 37 degrees C the adhesivity decreased by about 20%. Aggregates of cells preincubated at 0 degrees C for 20 min did not exhibit marked EM changes after 24-28 h in vitro. The present results have shown the rather high resistance of molecules responsible for cellular adhesion and its reversibility to temperature changes. Furthermore, non-specific cellular adhesion was shown on physically active DNA molecules.