Long-term cycling of surfactant films in Wilhelmy balance

1996 ◽  
Vol 8 (1) ◽  
pp. 173 ◽  
Author(s):  
B Sun ◽  
T Curstedt ◽  
B Robertson
Keyword(s):  
Surface Tension ◽  
Dependent Manner ◽  
Minimum Surface ◽  
Stable Period ◽  
Other Substances ◽  
Minimum Surface Tension ◽  
Surfactant Activity ◽  
Number Of Cycles ◽  
Dose Dependent

Surface properties of porcine surfactant were observed during long-term cycling in Wilhelmy balance. Various amounts of surfactant were applied onto the surface as dry particles or droplets, or were suspended in the hypophase, and the films generated by this material were subjected to 50% cyclic compression at a rate of 1 cycle per min. Film spreading was faster from a droplet than from a particle of lyophilized surfactant, but the 'stable period' during which minimum surface tension of the compressed film remained below 5 mN/m was significantly longer for the dry material. For surfactant suspensions the period of film 'refinement', defined as the number of cycles required to reduce minimum surface tension to a level below 5 mN/m, was inversely correlated with the concentration of surfactant in the hypophase. Thirteen batches of porcine surfactant, used successfully in clinical trials for treatment of neonatal respiratory distress syndrome, were evaluated in the same system suspended in the hypophase at a concentration of 0.5 mg/ml. Films adsorbed from these batches had a median refinement period of 4 cycles, and a median stable period of 2160 cycles (36 h). In the same assay system, surfactant activity was inhibited in a dose-dependent manner by serum, fibrinogen, meconium, and bilirubin, but the specific inhibitory activity was significantly higher for bilirubin than for the other substances tested.

scholarly journals Pulmonary Inflammation Disrupts Surfactant Function during Pneumocystis carinii Pneumonia

2001 ◽  
Vol 69 (2) ◽  
pp. 758-764 ◽  
Author(s):  
Terry W. Wright ◽  
Robert H. Notter ◽  
Zhengdong Wang ◽  
Allen G. Harmsen ◽  
Francis Gigliotti
Keyword(s):  
Surface Tension ◽  
Inflammatory Response ◽  
Pulmonary Inflammation ◽  
Pneumocystis Carinii ◽  
Lavage Fluid ◽  
Respiratory Impairment ◽  
Minimum Surface ◽  
Minimum Surface Tension ◽  
Surfactant Activity ◽  
Surfactant Dysfunction

ABSTRACT During Pneumocystis carinii pneumonia (PCP) in mice, the degree of pulmonary inflammation correlates directly with the severity of lung function deficits. Therefore, studies were undertaken to determine whether the host inflammatory response contributes to PCP-related respiratory impairment, at least in part, by disrupting the pulmonary surfactant system. Protein and phospholipid content and surfactant activity were measured in the lavage fluid of infected mice in either the absence or presence of an inflammatory response. At 9 weeks postinfection with P. carinii, nonreconstituted SCID mice exhibited no signs of pulmonary inflammation, respiratory impairment, or surfactant dysfunction. Lavage fluid obtained from these mice had protein/phospholipid (Pr/PL) ratios (64% ± 4.7%) and minimum surface tension values (4.0 ± 0.9 mN/m) similar to those of P. carinii-free control mice. However, when infected SCID mice were immunologically reconstituted, an intense inflammatory response ensued. Pr/PL ratios (218% ± 42%) and minimum surface tension values (27.2 ± 2.7 mN/m) of the lavage fluid were significantly elevated compared to those of the lavage fluid from infected, nonreconstituted mice (P < 0.05). To examine the specific role of CD8+ T-cell-mediated inflammation in surfactant dysfunction during PCP, mice with defined T-cell populations were studied. P. carinii-infected, CD4+-depleted mice had elevated lavage fluid Pr/PL ratios (126% ± 20%) and elevated minimum surface tension values (16.3 ± 1.0 mN/m) compared to normal mice (P < 0.05). However, when infected mice were additionally depleted of CD8+ cells, Pr/PL ratios were normal and surfactant activity was improved. These findings demonstrate that the surfactant pathology associated with PCP is related to the inflammatory process rather than being a direct effect of P. carinii. Moreover, CD8+ lymphocytes are involved in the mechanism leading to surfactant dysfunction.

A dual approach to self-stimulation and locomotor trace affected by chronic methamphetamine treatment for an animal model of schizophrenia

1993 ◽  
Vol 71 (5-6) ◽  
pp. 321-325 ◽  
Author(s):  
Morikuni Takigawa ◽  
Hiroshi Maeda ◽  
Kenichi Ueyama ◽  
Hidefumi Tominaga ◽  
Kei Matsumoto
Keyword(s):  
Animal Model ◽  
Negative Symptoms ◽  
Disease Model ◽  
Stereotyped Behavior ◽  
Dependent Manner ◽  
Dual Approach ◽  
Reverse Tolerance ◽  
Self Stimulation ◽  
Dose Dependent

The effect of long-term methamphetamine (MAP) treatment on intracranial self-stimulation of the lateral hypotholamus and locomotor traces was assessed. An attempt was made to provide a useful animal model for understanding anhedonia, stereotypy, and reoccurrence of liability, which are analogous to symptoms of schizophrenia. The frequency of intracranial self-stimulation (ICSS) as used as a measure of the animals' "hedonic–anhedonic" state. Following long-term MAP treatment (3 mg/kg), rats gradually showed stereotyped behavior, and became inactive and unresponsive to ICSS. These behavioral changes and decreased ICSS lasted several weeks after cessation of chronic MAP treatment and seemed to suggest post-MAP chronic psychosis and (or) anhedonia, two of the negative symptoms of schizophrenia. The traces of rat behavior affected by chronic MAP treatment were classified into three types, peripheral, mixed, and fixed, occurring in a dose-dependent manner. Reverse tolerance, similar to the reoccurrence of schizophrenic symptoms, was observed as a fixed stereotypy associated with loss of ICSS. These abnormal phenomena were suppressed by pretreatment with haloperidol. In the present study, the combination of ICSS and locomotor trace affected by chronic MAP treatment was proposed as an animal model of schizophrenia and as a useful technique for gauging the effect of neuroleptics.Key words: self-stimulation, anhedonia, stereotypy, reverse tolerance, animal disease model, schizophrenia, methamphetamine.

p-Nitrophenylphosphatase Activity Catalyzed by Plasma Membrane (Ca2++Mg2+)ATPase: Correlation with Structural Changes Modulated by Glycerol and Ca2+

2001 ◽  
Vol 21 (1) ◽  
pp. 25-32 ◽  
Author(s):  
Gutemberg G. Alves ◽  
Luis Maurício T. R. Lima ◽  
Maely P. Fávero-Retto ◽  
Adriana P. Lemos ◽  
Carlos E. Peres-Sampaio ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Synergistic Effect ◽  
Phosphatase Activity ◽  
Structural Changes ◽  
Center Of Mass ◽  
Binding Domain ◽  
Dependent Manner ◽  
Dose Dependent ◽  
Substrate Binding Domain

The plasma membrane (Ca2++Mg2+)ATPase hydrolyzes pseudo-substrates such as p-nitrophenylphosphate. Except when calmodulin is present, Ca2+ ions inhibit the p-nitrophenylphosphatase activity. In this report it is shown that, in the presence of glycerol, Ca2+ strongly stimulates phosphatase activity in a dose-dependent manner. The glycerol- and Ca2+-induced increase in activity is correlated with modifications in the spectral center of mass (average emission wavenumber) of the intrinsic fluorescence of the enzyme. It is concluded that the synergistic effect of glycerol and Ca2+ is related to opposite long-term hydration effects on the substrate binding domain and the Ca2+ binding domain.

Effects of fixatives on function of pulmonary surfactant

2002 ◽  
Vol 93 (3) ◽  
pp. 911-916 ◽  
Author(s):  
H. Bachofen ◽  
U. Gerber ◽  
S. Schürch
Keyword(s):  
Surface Tension ◽  
Pulmonary Surfactant ◽  
Osmium Tetroxide ◽  
Uranyl Acetate ◽  
Film Stability ◽  
Minimum Surface ◽  
Natural Surfactant ◽  
Equilibrium Surface Tension ◽  
Minimum Surface Tension ◽  
Surface Active

The structure of pulmonary surfactant films remains ill defined. Although plausible film fragments have been imaged by electron microscopy, questions about the significance of the findings and even about the true fixability of surfactant films by the usual fixatives glutaraldehyde (GA), osmium tetroxide (OsO4), and uranyl acetate (UA) have not been settled. We exposed functioning natural surfactant films to fixatives within a captive bubble surfactometer and analyzed the effect of fixatives on surfactant function. The capacity of surfactant to reach near-zero minimum surface tension on film compression was barely impaired after exposure to GA or OsO4. Although neither GA nor OsO4 prevented the surfactant from forming a surface active film, GA increased the equilibrium surface tension to above 30 mN/m, and both GA and OsO4 decreased film stability as seen in the slowly rising minimum surface tension from 1 to ∼5 mN/m in 10 min. In contrast, the effect of UA seriously impaired surface activity in that both adsorption and minimum surface tension were substantially increased. In conclusion, the fixatives tested in this study are not suitable to fix, i.e., to solidify, surfactant films. Evidently, however, OsO4 and UA may serve as staining agents.

Effect of oxygen breathing at atmospheric pressure on pulmonary surfactant

1965 ◽  
Vol 20 (5) ◽  
pp. 855-858 ◽  
Author(s):  
Samuel T. Giammona ◽  
Donald Kerner ◽  
Stuart Bondurant
Keyword(s):  
Surface Tension ◽  
Atmospheric Pressure ◽  
Pulmonary Surfactant ◽  
Species Difference ◽  
Foam Fractionation ◽  
Minimum Surface ◽  
Oxygen Breathing ◽  
Minimum Surface Tension ◽  
Effect Of Oxygen

To evaluate the effects of oxygen breathing at atmospheric pressure on pulmonary surfactant, cats, rabbits, and rats were continuously kept in 98% oxygen until death occurred. Pulmonary surfactant was extracted by mincing of the lung and by foam fractionation of the lung. Surface tension of the extracts was measured on a Wilhelmy balance. Lung extracts prepared by both methods from the cats and rabbits kept in oxygen had greater surface tension than lung extracts from control animals. Surface tension of extracts prepared by foam fractionation of lungs of rats kept in oxygen did not differ from that of extracts of lungs of control rats, whereas surface tension of extracts prepared by mincing lungs of rats kept in oxygen had minimum surface tension greater than that of lung extracts of control rats. This species difference in the effects of oxygen breathing on pulmonary surfactant may reflect a difference in the pathogenesis of oxygen intoxication. oxygen intoxication; surface tension Submitted on October 19, 1964

Swim-bladder surfactants of Amazon air-breathing fishes

1978 ◽  
Vol 56 (4) ◽  
pp. 946-952 ◽  
Author(s):  
C. F. Phleger ◽  
B. S. Saunders
Keyword(s):  
Surface Tension ◽  
Lung Tissue ◽  
Phospholipid Composition ◽  
Vascular Supply ◽  
Swim Bladder ◽  
Tissue Slices ◽  
Minimum Surface ◽  
Arapaima Gigas ◽  
Minimum Surface Tension ◽  
Hoplerythrinus Unitaeniatus

Minimum surface tension and phospholipid composition of fish lung and swim-bladder wash and tissue extract were determined on an obligate water breather, Hoplias malabaricus, two species of facultative air breathers, Hoplerythrinus unitaeniatus and Erythrinus erythrinus, and two species of obligate air breathers, Arapaima gigas and Lepidosiren paradoxa. In addition, lung tissue slices were incubated with [1-14C]acetale and [1-14C]palmitate.All lung and swim-bladder wash lipid extracts showed a minimum surface tension of 20–25 dyn/cm (1 dyn = 10 μN). The principle phospholipid of all species is phosphatidylcholine; no phosphatidylglycerol was detected in any sample.The two obligate air breathers had higher rates of incorporation of isotope in tissue slices than facultative air breathers and nonair breathers. This observation correlates well with the greater vascular supply to their lungs.The phospholipid patterns of these fishes are significantly different from those of mammals. We speculate that these lipids recovered from saline wash may not be important in the maintenance of lung stability. Perhaps their function is keeping water from leaking into the lung and swim bladder.

Effect of retinoic acid on limb regeneration in Xenopus laevis

1983 ◽  
Vol 61 (12) ◽  
pp. 2698-2702 ◽  
Author(s):  
Steven R. Scadding
Keyword(s):  
Retinoic Acid ◽  
Xenopus Laevis ◽  
Limb Regeneration ◽  
Dependent Manner ◽  
African Clawed Frog ◽  
Long Term Effect ◽  
Aquarium Water ◽  
Dose Dependent ◽  
Clawed Frog

The objective of this experiment was to determine the effect of retinoic acid on the process of limb regeneration in the African clawed frog, Xenopus laevis. Limbs were bilaterally amputated through the radio-ulna and then treated for 15 days with retinoic acid in the aquarium water, at 3, 15, or 75 IU/mL. The retinoic acid inhibited limb regeneration in a dose-dependent manner, reduced the length of the regenerates, and produced irregularities in the morphogenesis of the cartilage rod in the regenerate. The regenerated limbs were removed after 150 days by amputation through the humerus, and the limbs were again allowed to regenerate. In the retinoic acid treated animals, despite the fact that retinoic acid treatment had been discontinued over 4 months previously, limb regeneration was still inhibited. These results suggest that retinoic acid has a long-term effect on the treated animals.

scholarly journals Activation Effects of Polysaccharides ofFlammulina velutipesMycorrhizae on the T Lymphocyte Immune Function

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Zheng-Fei Yan ◽  
Nai-Xu Liu ◽  
Xin-Xin Mao ◽  
Yu Li ◽  
Chang-Tian Li
Keyword(s):  
Immune Function ◽  
T Lymphocyte ◽  
Interleukin 2 ◽  
Potential Effect ◽  
Dependent Manner ◽  
Health Products ◽  
Immune Health ◽  
Spleen Lymphocytes ◽  
Dose Dependent

Flammulina velutipesmycorrhizae have increasingly been produced with increasing ofF. velutipesproduction. A mouse model was thus used to examine potential effect ofF. velutipesmycorrhizae on the immune function. Fifty female Wistar mice (5-weeks-old) weighed 15–20 g were randomly allocated into five groups. Polysaccharide ofF. velutipesmycorrhizae were treated with mice and mice spleen lymphocytes. The levels of CD3+, CD4+, and CD8+T lymphocyte, interleukin-2 (IL-2), and tumor necrosis factor-a (TNF-α) were determined. The results showed that the proportions of CD3+, and CD4+T lymphocyte, the ratio of CD4+/CD8+, and the levels of IL-2 and TNF-a were significantly increased in polysaccharide ofF. velutipesmycorrhizae, while the proportion of CD8+T lymphocyte was decreased in polysaccharide ofF. velutipesmycorrhizae-dose dependent manner. Our findings indicated that a long term exposure of polysaccharide ofF. velutipesmycorrhizae could activate the T lymphocyte immune function. Polysaccharide ofF. velutipesmycorrhizae was expected to develop into the immune health products.

scholarly journals Premature Puberty and Thimerosal-Containing Hepatitis B Vaccination: A Case-Control Study in the Vaccine Safety Datalink

Toxics ◽  
2018 ◽  
Vol 6 (4) ◽  
pp. 67
Author(s):  
David Geier ◽  
Janet Kern ◽  
Mark Geier
Keyword(s):  
Hepatitis B ◽  
Case Control Study ◽  
Vaccine Safety ◽  
Case Control ◽  
Hepatitis B Vaccination ◽  
Dependent Manner ◽  
Hepatitis B Vaccines ◽  
Dose Dependent ◽  
Control Study

Studies suggest a relationship between exposure to endocrine disrupters, such as mercury (Hg), and premature puberty. Hg exposure from Thimerosal-containing hepatitis B vaccine, administered at specific intervals within the first six months of life, and the child’s long-term risk of being diagnosed with premature puberty (ICD-9 code: 259.1), was retrospectively examined, using a hypothesis-testing, longitudinal case-control design on prospectively collected data, in the Vaccine Safety Datalink (VSD). Cases diagnosed with premature puberty were significantly more likely to have received increased exposure to Hg from hepatitis B vaccines preserved with Thimerosal given in the first month after birth (odds ratio (OR) = 1.803), first two months after birth (OR = 1.768), and first six months after birth (OR = 2.0955), compared to control subjects. When the data were separated by gender, the effects remained among females but not males. Female cases, as compared to female controls, were significantly more likely in a dose-dependent manner to have received a greater exposure to Hg from hepatitis B vaccines preserved with Thimerosal, given in the first six months after birth (OR = 1.0281 per µg Hg). The results of this study show a dose-dependent association between increasing organic Hg exposure from Thimerosal-containing hepatitis B vaccines administered within the first six months of life and the long-term risk of the child being diagnosed with premature puberty.

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