Dynamic surface tension of saliva: general relationships and application in medical diagnostics.

Maximum bubble pressure and pendent drop profile analysis tensiometry are used to study the dynamic surface tension and rheological characteristics of saliva samples taken from volunteers of various sexes and age, and children with caries. The tensiometric characteristics of the secretions released by parotid, submandibular and sublingual glands are studied, and age-related and sex-related changes of some tensiometric characteristics of saliva are found. The differences are most essential for the tensiometric characteristics of saliva samples taken from caries-free children as compared with those taken from children with caries. Thus, the dynamic interfacial tensiometry is very sensitive and capable of providing information additional to the biochemical data about the properties of saliva, and could be recommended for the development of new diagnostic methods in dentistry.

Dilational rheology of serum albumin and blood serum solutions as studied by oscillating drop tensiometry.

Oscillating drop experiments with a drop profile analysis tensiometer provide the dilational elasticity and viscosity of surface layer. Model experiments for blood serum, composed of HSA and the non-ionic surfactant C(14)EO(8), are used to demonstrate the theoretical approach for calculating the visco-elasticity of mixed adsorption layers from the adsorption characteristics of the single components. Experiments with real serum samples taken from patients choledocholithiasis-based benign obstructive jaundice before and after re-canalisation of the biliary tract demonstrate that the visco-elasticity of the respective adsorption layers is very sensitive of the successful surgery.

[Effect of modulator of the signal transmission from opioid receptor to sodium channels on hypothalamus self-stimulation]. / Vliianie moduliatora peredachi signalov ot opioidnogo retseptora k natrievym kanalam na samostimuliatsiiu gipotalamusa.

We investigated effects of different doses of a new preparation comenic acid as a modulator of the transmission of signals from an opioid receptor to slow sodium channels on the hypothalamic rewarding system in male Wistar rats. Comenic acid has been shown to inhibit the reaction of the hypothalamic self-stimulation (SS) in a dose-dependent fashion with the strongest effect at doses of 28.8-30 mg/kg. We observed a decrease in the rate of lever-pressings, induced by the threshold for SS current intensity, and an increase in the threshold for the response of SS, or its cessation. The similar suppressing effect of the preparation was found at its repeated injections. Thus, those results showed that comenic acid failed in both activation of the rewarding system of the lateral hypothalamus and adaptation to it.

[Projections of the dorsal raphe nucleus and midbrain central gray substance to the cat limbic system]. / Proektsii dorsal'nogo iadra shva i tsentral'nogo serogo veshchestva srednego mozga na limbicheskie struktury u koshki.

Morphological organization of connections of ventro-lateral (nociceptive) and dorso-lateral (analgetic) midbrain central gray (vl SGC and dl SGC), as well as of dorsal raphe nucleus (analgetic zone, Rd), with different limbic structures, responsible for the formation of various emotional states, was studied in 26 cats. The methods of electrical destruction of brain areas were used that were followed by the light and electron microscopic study of degenerating fibers and synapses. Heterogeneity of connections of above mentioned formations with different limbic structures was demonstrated. Connections Rd and dl SGC with upstream limbic structures were found to be very similar in their organization and expression. Connections of vl SGC with the same structures were significantly different. It is suggested that similar (antinociceptive) function of dl SGC and Rd has determined the likeness of their connections. This, in combination with the heterogeneity of SGC in conduction of the pain and analgesia, supports the identification of two brain systems: nociceptive, conducting pain sensitivity, and antinociceptive, inhibiting its conduction. The nociceptive system includes the following structures: vl SGC, posterior and lateral hypothalamic nuclei, preoptic area. In the antinociceptive system two subsystems could be distinguished: midbrain units of these subsystems are localized in different structures (Rd and dl SGC), while the upstream ones are found in the same hypothalamic nuclei--ventromedial, dorsomedial, paraventricular. As far as septum, amigdala, hippocampus and cingular cortex are concerned, it was found impossible to refer them to any of these systems--either nociceptive or antinociceptive--basing solely on the findings of morphological studies because of approximately similar representation of axons of neurons in vl SGC, dl SGC, Rd in these structures.

[Physical and chemical properties of the condensate of breathed-out air in healthy people]. / Fiziko-khimicheskie svoistva kondensata vydykhaemogo vozdukha u zdorovykh liudei.

The physical-and-chemical condition of condensate of breathed-out moisture (CBM) was studied by the computer-aided analysis of axis-symmetric drops' form in healthy subjects; such condition was found to depend on sex, age and smoking-addiction of the examined persons. The surface tension of the mentioned moisture correlated with its viscoelastic index and with relaxation. The metabolites of nitric oxide, lipids, urea, lactic acid (not uric acid) and of hydrogen peroxide were found to influence the physical-and-chemical parameters of respiratory moisture. Hydrogen peroxide had a reverse correlation with the CBM viscoelastic module. A status of the pulmonary surfactant can be evaluated by using the studied physical-and-chemical CBM parameters.

Dynamic surface tension and surface rheology of biological liquids.

The paper presents results of dynamic and equilibrium surface tension measurements (using a maximum bubble pressure instrument) of serum and urine samples that were obtained from 80 healthy human of various sexes and ages. These data were compared with surface tension measurements of biological liquids obtained from patients suffering from malignant neoplasm of corpus uteri (n=5) and cervix uteri (n=31). In addition, surface dilatational rheology was determined on 32 samples using a drop shape method. The dilatational rheology data were compared with the dynamic surface tension data. Although some trends were found, no significant correlations exist between surface tension and rheology data and any of the disease states or stages. It is difficult to explain these findings in the framework of known mechanisms. However, our studies demonstrate that dynamic interface tensiometry of human biological liquids provide new insight into the biophysical behavior of these liquids, most likely reflecting compositional changes of them during ageing, the course of cancer and as a consequence of therapeutical interventions.

[Dynamic interphasic tensimetry of blood and urine in systemic lupus erythemotosus]. / Dinamicheskaia mezhfazovaia tenziometriia krovi i mochi pri sistemnoi krasnoi volchanke.

AIM: To study dynamic surface tension (DST) of blood and urine in SLE patients. MATERIALS AND METHODS: Clinical, immunological examinations, DST of blood and urine using computer tensiometers were made in 67 SLE patients aged 15 to 62 years. RESULTS: Changes in interphasic tensiograms in males and females were characterized regarding the course, activity of the pathological process and the presence of certain clinical symptoms. Effective therapy return to normal DST of the biological fluids. Correlations between interphasic tensiograms of blood, urine and levels of proteins, lipids, non-protein and inorganic surfactants and surface-inactive substances were established as well as relations of DST with biochemical composition of the biological fluids. CONCLUSION: The above diagnostic method may be useful for differential diagnosis, assessment of the clinical course, activity of the disease, control over effectiveness of the treatment.

Integration of thermal and osmotic afferent signals in the preoptic/anterior hypothalamic neurons.

Our in vivo experiments were aimed at studying afferent links of the preoptic/anterior hypothalamus system, which integrates thermal and osmotic homeostasis. Special attention was paid to using stimulation intensities within the normal physiological range. The experiments were carried out on adult cats anesthetized with ketamine (25mg/kg) and inhalation of nitrous oxide (75 vol.%). Short-term shifts in the osmotic pressure within the cerebral vasculature were induced by infusions of 200-500 microl 3.0% or 0.2% NaCl solutions into the homolateral a. carotis (hyper- and hypoosmotic stimulations, respectively). Thermal stimulation was provided by local heating or cooling of the contralateral forelimb pad skin (+/-7.0 degrees C range). Reactions of preoptic/anterior hypothalamus neurons were classified into four types: monophasic activation, monophasic inhibition, and biphasic responses including excitation followed by inhibition or primary inhibition followed by activation. Monophasic activation was a very common occurrence among preoptic/anterior hypothalamus neuronal reactions. The responsiveness of thermosensitive preoptic/anterior hypothalamus neurons to hyperosmotic stimulation turned to be noticeably higher than that to hypoosmotic stimulation. Practically equal proportions of warm- and cold-sensitive neurons demonstrated changes in the firing activity resulting from intracarotid infusions of 3.0% NaCl solution. Infusions of 0.2% NaCl solution induced firing rate modifications in 26% (12/46) of warm-sensitive and in 32% (18/39) of cold-sensitive neurons. Cold-sensitive neurons displayed a higher sensitivity to a short-term osmotic pressure elevation in the cerebral vasculature (63%, 33/52) than warm-sensitive neurons did (43%, 22/52, P<0.05). In our study, a maximum similarity in the response types was observed when hyperosmotic infusion and skin cooling were applied, while a maximum disagreement was found when hyperosmotic stimulations were combined with skin heating. There is no doubt that preoptic/anterior hypothalamus neurons play a crucial role in the maintenance of body temperature. Several studies have also shown that osmoregulation can be affected by shifts in peripheral and hypthalmic temperatures. Information on the neurol mechanisms of interactions between the thermo- and osmoregulatory circuits in the hypothalamus remains limited. We discuss the obtained data considering the "set-point theory" of thermal hameostasis maintenance.

[Dynamic surface tension of blood in chronic dust bronchitis in coal mines workers]. / Dinamicheskoe poverkhnostnoe natiazhenie krovi pri khronicheskom pylevom bronkhite u gornorabochikh ugol'nykh shakht.

Chronic dust bronchitis in miners is associated with increase in dynamic surface tension of blood at short (t = 0.01 s) and medium (t = 1 s) surface lifetimes with lower declination angle of interphase tensiograms curve. Surface tension disorders were similar to those in experimental dust bronchitis. There are correlations between surface tension parameters and the workers' underground length of service, some mining geologic conditions and serum level of proteous and lipid surfactants.

Studies on the application of dynamic surface tensiometry of serum and cerebrospinal liquid for diagnostics and monitoring of treatment in patients who have rheumatic, neurological or oncological diseases.

Human biological liquids comprise various surfactants, which adsorb at liquid interfaces and lead to a variation in surface tension. The adsorption processes involving low molecular weight surfactants, proteins and phospholipids play a vital role in the physiological functions of the human organism, especially if large surfaces are involved (e.g., gas exchange in lungs, metabolism of kidneys, liver and brain). Dynamic surface tensiometric studies of biological liquids like serum and cerebrospinal fluid provide surrogate parameters that reflect surface tension phenomena. We provide dynamic surface tension data of serum and cerebrospinal fluid that were collected from healthy volunteers and patients with rheumatic, neurological or oncological diseases. Our studies indicate that dynamic surface tension data are helpful for diagnostic purposes and for monitoring of therapeutic interventions.

Dynamics of protein and mixed protein/surfactant adsorption layers at the water/fluid interface.

The adsorption behaviour of proteins and systems mixed with surfactants of different nature is described. In the absence of surfactants the proteins mainly adsorb in a diffusion controlled manner. Due to lack of quantitative models the experimental results are discussed partly qualitatively. There are different types of interaction between proteins and surfactant molecules. These interactions lead to protein/surfactant complexes the surface activity and conformation of which are different from those of the pure protein. Complexes formed with ionic surfactants via electrostatic interaction have usually a higher surface activity, which becomes evident from the more than additive surface pressure increase. The presence of only small amounts of ionic surfactants can significantly modify the structure of adsorbed proteins. With increasing amounts of ionic surfactants, however, an opposite effect is reached as due to hydrophobic interaction and the complexes become less surface active and can be displaced from the interface due to competitive adsorption. In the presence of non-ionic surfactants the adsorption layer is mainly formed by competitive adsorption between the compounds and the only interaction is of hydrophobic nature. Such complexes are typically less surface active than the pure protein. From a certain surfactant concentration of the interface is covered almost exclusively by the non-ionic surfactant. Mixed layers of proteins and lipids formed by penetration at the water/air or by competitive adsorption at the water/chloroform interface are formed such that at a certain pressure the components start to separate. Using Brewster angle microscopy in penetration experiments of proteins into lipid monolayers this interfacial separation can be visualised. A brief comparison of the protein adsorption at the water/air and water/n-tetradecane shows that the adsorbed amount at the water/oil interface is much stronger and the change in interfacial tension much larger than at the water/air interface. Also some experimental data on the dilational elasticity of proteins at both interfaces measured by a transient relaxation technique are discussed on the basis of the derived thermodynamic model. As a fast developing field of application the use of surface tensiometry and rheometry of mixed protein/surfactant mixed layers is demonstrated as a new tool in the diagnostics of various diseases and for monitoring the progress of therapies.

[Pulmonary surfactant status in experimental dust-induced bronchitis based on the data from dynamic interphase tensiometry]. / Sostoianie legochnogo surfaktanta pri éksperimental'nom pylevom bronkhite po dannym dinamicheskoi mezhfaznoi tenziometrii.

The disease was simulated by inhalation of dust containing 29% of free silica in Wistar male rats during 8 months. One group of the subjects was kept under 26-28 degrees C and other one--under 38-40 degrees C. Dynamic surface tension of lung tissue homogenate was studied by means of computer tensiometer MRT (Lauda, Germany). Interphase tensiometry precisely characterizes state of lung surfactant in experimental chronic dust bronchitis. Equilibrium surface tension and surface tension for 0.01 and 1 sec deteriorate during combined exposure to silica dust and heating microclimate. The studies demonstrated strong correlation between interphase tensiogram parameters and individual lipids content of lung surfactant. Surface tension is related to the state of lipids peroxidation in lungs and antioxidant systems.

[Dynamic middle-phase tensiometry of blood and urine in female patients with malignant tumors of the reproductive organs]. / Dinamicheskaia mezhfaznaia tenziometriia krovi i mochi pri zlokachestvennykh opukholiakh reproduktivnykh organov zhenshchin.

An improved version of the MPT2 (LAUDA) computerized tensiometer (Germany) was used to measure dynamic surface tension (ST) of blood and urine by the maximum bubble pressure method in patients with tumors of the uterus, vagina and cervical canal. Relatively low blood and urine ST values at t-->infinity and serum at t = 1 s were registered. Combined radiotherapy involved oppositely-directed changes in the equilibrium (static) ST of the biological fluids as well as a urine ST inhibition in the surface short-life range (t = 0.01 s). The slope of blood serumtension curves by the end of treatment was close to that in healthy females.

[Dynamic interphase tensiometry of the cerebrospinal fluid and blood serum in nervous system tumors]. / Dinamicheskaia mezhfaznaia tenziometriia spinnomozgovoi zhidkosti i syvorotki krovi pri opukholiakh nervnoi sistemy.

Dynamic superficial tension (ST) of spinal fluid (SF) and blood serum in patients with CNS tumors was investigated. The maximum bubble tension was measured by a MPT2 computer tensiometer (LAUDA). There were decreases in ST of blood serum at t = 1 and t-->infinity, increases in ST at t = 0.01 and decreases in the angle on SF tensiograms. The parameters of interphasic tensiometry of the biological fluids depend on content of biologically active substances severity of the neurological symptomatology and duration of disease. Successive surgical treatment is followed by normalization of SF and blood serum ST.

[Dynamic surface tension of blood and synovial fluid in rheumatoid arthritis]. / Dinamicheskoe poverkhnostnoe natiazhenie krovi i sinovial'noi zhidkosti pri revmatoidnom artrite.

AIM: Assessment of the dynamic surface tension (DST) of blood serum (BS), synovial fluid (SF) in various courses of rheumatoid arthritis (RA). MATERIALS AND METHODS: Forty three patients with RA and 63 apparently healthy individuals were examined. DST of BS and SF was determined in the computer-aided tensiometer and some blood biochemical parameters were also measured. RESULTS: DST of BS in patients with RA were found to be higher than the normal values and some parameters c beta 2 and beta 3) of BS DST did not significantly differ from the normal values whereas others (beta 1 and gamma proved to be much lower. Depending on the disease course variants, there were some differences in these DST changes. There was a feedback between DST parameters and the levels of immunoglobulins, beta 2-microglobulin, and lipids in blood. CONCLUSION: Assessment of BS and SF DST may be useful in the differential diagnosis of RA, in the determination of its intensity and prognosis, and therapeutical efficiency.

[Changes in the dynamic surface tension of the blood and urine during the development of visceritis in patients with rheumatoid arthritis]. / Izmeneniia dinamicheskogo poverkhnosnogo natiazheniia krovi i mochi pri razvitii vistserita u bol'nykh revmatoidnym artritom.

The condition was studied of the dynamic surface tension of biologic fluids in patients with rheumatoid arthritis using a method of maximum pressure in the vesicle with the aid of computerized tensiometer MPT-1 "Lauda" (Germany). Rise in indices of blood serum surface tension with diminution of the slope of tensiogram curves may suggest the development of pathology of the heart and liver, while increase in the same parameters of urine might be indicative of the coming nephropathy.

[The dynamic surface tension of the blood and urine in chronic glomerulonephritis]. / Dinamicheskoe poverkhnostnoe natiazhenie krovi i mochi pri khronicheskom glomerulonefrite.

Dynamic surface-tension (S-T) was investigated of blood and urine of healthy individuals and patients with chronic glomerulonephritis by the proposed method of maximum pressure in a bubble with the aid of the computer-assisted device tensometer MPT-1 (Lauda, Germany). Patterns of changes in dynamic and static S-T were found out as were those of the slope of the curve in patients with mesangioproliferative and mesangiocapillary variants of the condition, in nephrotic syndrome and chronic renal insufficiency. Correlation type comparison was performed of physical-and-chemical properties of biological fluids to parameters characterizing protein and fat exchange. Relationship between dynamic S-T and biochemical composition of blood and urine was revealed. Diagnostic value of results of the studies made is discussed.

[DNA synthesis in heterodikaryons obtained by the fusion of long-term stimulated cells of the NIH 3T3 line with short-term stimulated cells]. / Sintez DNK v geterodikarionakh, poluchennykh pri sliianii dlitel'no stimulirovannykh kletok linii NIH 3T3 s kratkovremenno stimulirovannymi kletkami.

Serum-deprived (0.2%) resting NIH 3T3 mouse fibroblasts, stimulated for 0.5-4.0 h by serum (10%) or PDGF (beta-beta homodimer) (early cells), were fused with stimulated cells taken 10 h after changing the medium to one containing 10% serum DNA synthesis was investigated in the nuclei of monokaryons, homodikaryons and heterodikaryons, using radioautography with the double-labeling technique. Preincubation of resting cells with serum for 3 h or with the competence factor PDGF for 1.0-1.5 h abolished their ability to suppress DNA synthesis in late stimulated nuclei in heterodikaryons. Actomycin D restores the inhibitory capacity of resting cells stimulated by PDGF but not by serum. The results give evidence that the acquirement by resting cells of competence for DNA replication includes as a necessary step the down-regulation of intracellular growth inhibitors, and thus serum can overcome the influence of endogenous growth inhibitors, at any rate, by two ways.

Transient inhibition of protein synthesis induces expression of proto-oncogenes and stimulates resting cells to enter the cell cycle.

There is evidence that resting cells are able to produce molecules with antiproliferative activity, some of which behave as short-lived repressor proteins. We suggest that transient inhibition of protein synthesis in resting cells would lead to a decrease in the levels of these negative growth regulators and might, therefore, promote mitogenic responses. We report that treatment of resting (serum-deprived) NIH 3T3 cells with cyclocheximide (CH) or puromycin induces expression of c-fos, c-jun and c-myc proto-oncogenes in a manner similar to that of platelet-derived growth factor (PDGF). Actinomycin D (Act D) abrogates the induction of proto-oncogene expression. Transient inhibition of protein synthesis by CH or puromycin also induces the resting NIH 3T3 and C3H 1OT1/2 cells to enter the cell cycle. Inhibition of new RNA or protein synthesis abolishes the proliferative response. These findings show that control mechanisms at both transcriptional and translational levels are operative in the resting cells treated with protein synthesis inhibitors. Cell fusion experiments with resting and serum-stimulated NIH 3T3 cells revealed that brief pre-incubation of resting cells with either PDGF, CH or puromycin abrogates their ability to suppress the onset of DNA synthesis in the nuclei of stimulated cells in heterodikaryons. However, the abrogative effect of PDGF disappeared in the presence of Act D, whereas the effects of protein synthesis inhibitors did not, indicating their independence of the induction of transcription. The data suggest that the observed effects of protein synthesis inhibitors are connected with elimination of some short-lived negative growth regulators, since a brief translational arrest is sufficient for the resumption of DNA synthesis in the nuclei of stimulated cells blocked by resting cells in heterodikaryons.