In order to obtain a complete and lees contaminated lung washings from the rabbits, the left lung of rabbit was subjected to lavage with saline by altering the number of washing, i.e.: once, twice and thrice, and surface tension, protein content and phospholipid content of the lung washings were measured. Surface tension was measured by the modified Langmuir-Wilhelmy balance, Phospholipid content was determined by the modified method of Baginski, and protein content by the method of Lowry et al. The results obtained are summerized as follows: 1. The maximal surface tension, minimal surface tension, stability index, protein content and phospholiped content of left lung washings (once) were 53.9+/-2.7 dyne/cm, 11.4+/-8.4 dyne/cm, 1.4+/-0.4, 127.2+/-6.0 ug/ml, and 306.8+/-65.4 ug/ml, respectively. 2. The maximal surface tension, stability index, protein content and phospholipid content of left lung washings (twice) were 55.5+/-2.4 dyne/cm, 5.0+/-2.2 dyne/cm, 1.7+/-0.2, 166.6+/-11.0 ug/ml and 283.5+/-40.1 ug/ml, respectively. 3. The maximal surface tension, minimal surface tension, stability index, protein content, and phospholipid content of left lung washings (thrice) were 53.6+/-2.6 dyne/cm, 6.2+/-2.2 dyne/cm, 1.6+/-0.1, 184.3+/-15.4 ug/ml and 368.3+/-68.2 ug/ml, respectively. 4. The above results indicate that the most optimal number of rabbit left lung washing is twice.
Lung* ; Rabbits ; Surface Tension ; Therapeutic Irrigation

A lot of experimental findings have confirmed that: Animal cells acquire a spherical shape just before the division; Under biochemical stimulus of mitotic apparatus aster the cells form a contractile ring in equator plane, and the mother cell divides into two daughter cells; meanwhile the total volume keeps constant. In Zinemanas and Nir's model the reorientation of microfilament and the visco-elasticity of cortex have been took into consideration. In our present work, the effective coefficient m due to biochemical stimulus was incorporated into the model, and the local distribution C was modified to diffuse with the plasma membrane motion. The numerical results showed that the formation of a contractile ring and parameters such as the surface tension in the furrow and internal pressure can be predicted successfully. Compared with Zinemanas and Nir's model, the results of our model are more correspondent with the experimental results. It can be concluded that the effective coefficient m has limited effects on the process control of cytokinesis.
Animals ; Biomechanical Phenomena ; Cytokinesis ; Humans ; Models, Biological ; Surface Tension

Pulmonary surfactant instillation is the treatment of choice in neonatal respiratory distress syndrome. The development of artificial surfactant has three decades of history. Animal-derived artificial surfactant is used in most countries and consists of 80% phospholipids and glycerol. 10% of the formulation is comprised of surfactant proteins, which have the critical role in surfactant function of lowering surface tension in the alveoli. Synthetic surfactants are made using synthetic peptide analogues as the surfactant protein counterparts. These are not the same as the human surfactant protein sequences; however, researchers are attempting to find the ideal synthetic peptide sequence for use in synthetic surfactants. Prophylactic and rescue surfactant therapy are two main therapeutic options. A recent recommendation emphasizes the importance of rescue therapy with continuous positive nasal airway pressure, rather than prophylactic use immediate after birth. This article briefly reviews the history and physiology of surfactant use, as well as clinical practice of surfactant and future studies.
Glycerol ; Humans ; Parturition ; Phospholipids ; Physiology ; Pulmonary Surfactants* ; Respiratory Distress Syndrome, Newborn ; Surface Tension ; Surface-Active Agents

The benefits of exogenous synthetic or animal-derived natural surfactants for treatment of respiratory distress syndrome (RDS) are well established. Although synthetic surfactants have potential safety advantages over animal-derived products, they seem to be clinically inferior to animal-derived natural surfactant, based on the results of numerous comparative trials. In recent years, however, synthetic surfactant has experienced a surge in breakthroughs to the point of rivaling natural surfactant, mainly due to the development of protein-containing synthetic surfactant. This article will review the historical background on the development of artificial pulmonary surfactant, compositional and physicochemical aspects on pulmonary surfactant lipids and proteins, results of comparative trials among natural, protein-free and protein-containing surfactants, and current status of development of protein-containing surfactants for treatment of RDS.
Humans ; Hyaline Membrane Disease ; Infant, Newborn ; Infant, Premature ; Proteins ; Pulmonary Surfactants ; Surface Tension ; Surface-Active Agents

PURPOSE: In this study, natural pulmonary surfactant was extracted from bovine lung lavage and its surface activity was determined. To investigate the usefulness of synthetic peptides reconstituted with phospholipid as artificial surfactant, truncated peptides from surfactant protein (SP)-B were synthesized and restored the surface tension lowering activities when appropriately recombined with phospholipid. METHODS: Crude natural surfactant (CNS) was isolated from lung lavage by centrifugation and organic solvent for the extraction of pulmonary surfactant was selected to satisfy the in vitro physical properties. Two truncated peptides derived from C-terminal end of bovine SP-B hydrophobic protein were selected and synthesized. To prepare artificial surfactant, synthetic peptides was added to the phospholipid mixture. The various surfactant mixtures were assayed for in vitro physical activity with the Wilhemly plate method and were determined by surface spreading rate, surface adsorption rate and surface tension-area diagram. RESULTS: CNS-chloroform methanol (CM) displayed efficient surface activity compared with clinically used Surfacten but CNS-BuOH did not. The artificial surfactants containing phospholipid mixture and synthetic peptide were analyzed for their surface activities and displayed significant surfactant properties. CONCLUSION: 1-Butanol or CM (3:1) was used as an extraction solvent for CNS. CNS-CM showed more efficient surface activity than CNS-BuOH. Two synthetic peptides composing artificial pulmonary surfactant were designed and mixing ratio of peptide and phospholipid was established. Artificial surfactant dispalyed weaker surface activity than natural surfactant but significant surfactant activity.
1-Butanol ; Adsorption ; Bronchoalveolar Lavage ; Centrifugation ; Methanol ; Motor Activity* ; Peptides ; Pulmonary Surfactants* ; Surface Tension ; Surface-Active Agents

PURPOSE: Neonatal respiratory distress syndrome is caused by the deficiency of lung surfactant in premature babies. For the treatment of RDS at present surfactants such as Surfacten (Tokyo-Tanabe Co., Japan) and Exosurf (Wellcome Co., USA) are used. As awarded the grant from the Ministry of Science and Technology for a model research project of Medium-Technology program, we have modified (supplemented) the bovine lung extracts to get YY-38, for which we have performed physical and biological activities. METHODS: For physical properties, we performed stable microbubble test (SMR) and measured surface tension lowering activity using a pulsating bubble surfactometer. Minimum and maximum surface tensions measured at 1 and 5 minutes gave surface tension-surface area diagrams, from which compressibility at surface tension 10mN/m was also calculated. As to the biological activity, we used premature rabbit fetuses as a model for the study of pressure-lung volume relationship. The lung pathology was examined on the lung tissues subsequently obtained, and aerated area ratios were calculated based on the area measured by an image analyzer. RESULTS: The minimum surface tensions of YY-38 at 1 and 5 minutes for all different concentrations were low at 10mN/m, while the maximum surface tensions ranged from 33.01mN/m to 41.07mN/m. The surface tension-surface area curve showed a definite hysteresis at 1 and 5 minutes for all concentrations, and the surface tension fell below 10mN/m with 20% surface area compression. The compressibilities at surface tension 10mN/m at 5minutes for all concentrations were all below 0.02. In animal experiments, the mean lung volume of premature rabbit fetuses was inflated to 80.9ml/kg at maximum 30cmH2O, while the lung volume was maintained at 38.3mg/kg when the lung was deflated to 5cmH2O. The overall aerated area ratio was 45.4%. CONCLUSIONS: YY-38 formed sufficient amount of stable microbubbles and had a surface tension low enough to maintain alveolar stability and to exhibit a good hysteresis curve. In animal experiments it helped the expansion of premature lungs during inspiratory phase and was effective in the prevention of collapse during expiratory phase.
Animal Experimentation ; Awards and Prizes ; Fetus ; Financing, Organized ; Lung* ; Microbubbles ; Pathology ; Respiratory Distress Syndrome, Newborn ; Surface Tension ; Surface-Active Agents

OBJECTIVES: In this study, we investigated the biodegradation features of 4 perfluorooctanesulfonate (PFOS) alternatives developed at Changwon National University compared to those of PFOS. METHODS: Biodegradation testing was performed with microorganisms cultured in the good laboratory practice laboratory of the Korea Environment Corporation for 28 days following the Organization for Economic Cooperation and Development guidelines for the testing of chemicals (Test No. 301 C). RESULTS: While C₈F₁₇SO₃Na, PFOS sodium salt was not degraded after 28 days, the 4 alternatives were biodegraded at the rates of 20.9% for C₁₅F₉H₂₁S₂O₈Na₂, 8.4% for C₁₇F₉H ₂₅S₂O₈Na₂, 22.6% for C₂₃F₁₈H₂₈S₂O₈Na₂, and 23.6% for C₂₅F₁₇H₃₂O₁₃S₃Na₃. CONCLUSIONS: C₂₅F₁₇H₃₂S₃O₁₃Na₃, C₂₃F₁₈H₂₈S₂O₈Na₂, and C₁₅F₉H₂₁S₂O₈Na₂ were superior to PFOS in terms of biodegradation rates and surface tension, and thus they were considered highly applicable as PFOS alternatives. Environmental toxicity, human toxicity, and economic feasibility of these compounds should be investigated prior to their commercialization.
Gyeongsangnam-do ; Humans ; Korea ; Organisation for Economic Co-Operation and Development ; Sodium ; Surface Tension

Conflicting results have been reported regarding the effects of ether anesthesia on the surfactant system of the lung, and little has been known on the effects of methoxyflurane anesthesia on the activity of the pulmonary surfactant. In the present study, an effort was made to observe and clarify possible effects of ether and methoxyflurane anesthesia on the activity of surfactant of the rabbit lung extracts, subjecting the rabbit to the light or deep anesthesia with the anesthetics by the non-rebreathing system. Tension-area (T-A) diagram of the lung extract was recorded automatically by a modified Langmuir-Wilhelmy balance with a synchronized recording system. The arterial blood pressure and heart rate during the entire stages of anesthesia were also recorded. The surface tension of the lung extracts, arterial blood pressure and heart rate thus obtained were compared with those of the non-anesthetized control group, and the results are summarized as follows: 1, The maximal surface tension, minimal surface tension, width of the T-A diagram at the surface area of 40% and stability index of the control group were 35.15+/-4.49 dynes/cm, 12.40+/-2.73 dynes/cm, 18.15+/-4.0 dynes/cm and 0.96+/-0.23, respectively.2. No significant difference was observed in the activity of surfactant of the lung extract prepared from the rabbit anesthetized with ether or methoxyflurane throughout the entire experiment. 3. In the ether anesthesia group, arterial blood pressure decreased gradually from the control value of 102.38+/-10.99 mmHg as the anesthesia deepened. The heart rate was slightly elevated in light stages of ether anesthesia from the control value of 284.95+/-35.91/min, but 120 min after deep anesthesia the heart rate returned to the control value. 4. Anesthesia with methoxyflurane produced a significantly decreased arterial blood pressure from the beginning and throughout the entire anesthesia stage. The heart rate did not change significantly througbout the entire anesthesia compripg with the control. 5. The above results suggest that the inhalation anesthesia with ether or methoxyflurane do not produce any significant change in the activity of pulmonary surfactant.
Anesthesia* ; Anesthesia, Inhalation ; Anesthetics ; Arterial Pressure ; Ether* ; Heart Rate ; Lung ; Methoxyflurane* ; Pulmonary Surfactants* ; Rabbits* ; Surface Tension

OBJECTIVETo study relationships between the main active ingredients and physical and chemical parameters of dangguibuxue decoction, and to explore the feasibility of characterization the quality of decoction by physical and chemical parameters.

METHODSolutions of ferulic acid and astragaloside with different concentrations were prepared, of which physical and chemical parameters such as surface tension, pH value and conductivity, etc were determined at 25 degrees C. And polynomial regression analysis was used to analyze these data.

RESULTWith the increase of concentration of ferulic acid, pH value was decreased and conductivity was increased. And surface tension was decreased in the aqueous solution of astragaloside. In the combined solution of ferulic acid and astragaloside, ferulic acid was the main influencing pH value and conductivity, while astragaloside was the main factor influencing surface tension.

CONCLUSIONOn one hand, astragaloside concentration has a significant correlation with surface tension, but almost no correlation with pH value and conductivity. On the other hand, ferulic acid concentration has a strong correlation with pH value and conductivity, but almost no correlation with surface tension. In addition, each parameter has strong anti-interference ability and almost didn't change with the addition of another material. These preliminary results suggested that such characteristic parameters could be used to characterize the decoction quality.

OBJECTIVETo observe changes in surface tension of bronchoalveolar lavage fluids (BALF) in rabbits with hyperbilirubinemia and the influence of bile diluents and 5 different bile acids on BALF surface tension to provide better insight into the regulatory role of bile acids on respiratory function.

METHODSBronchoalveolar lavage with 0.9% normal saline was carried out in 30 male New Zealand rabbits and the surface tensions of BALF were measured. The changes in BALF surface tension was measured in rabbits with hyperbilirubinemia. Different concentrations of bile diluents, normal saline, or water solutions of 5 bile acids were added into the collected BALF to test their influence on the surface tension of BALF.

RESULTSThe BALF from rabbits with hyperbilirubinemia showed a significantly increased surface tension (P<0.05). The bile diluents (1:15, 1:10, and 1:5) added into the BALF increased the surface tension of the BALF by 21.15%, 26.09%, and 19.64%, respectively. Among the water solutions of the 5 bile acids, UDCA produced no significant influence on the surface tension of BALF while CDCA, CA, LCA, and DCA increased the surface tension by 16.10%, 21.66%, 14.21%, and 13.05%, respectively.

CONCLUSIONThe surface tension of BALF increases significantly during hyperbilirubinemia. Bile diluents as well as the free bile acids CDCA, CA, LCA and DCA, but not UDCA, can increase the surface tension of BALF, suggesting that these bile acids may emulsify pulmonary alveolar surfactants to increase the alveolar surface tension.