The Mechanism of Fibrinolysis Induced by Bacterial Pyrogens

1959 ◽  
Vol 03 (02) ◽  
pp. 286-296 ◽  
Author(s):  
E Deutsch ◽  
P Elsner ◽  
I Marschner ◽  
Keyword(s):  
Intravenous Injection ◽  
Fibrinolytic Activity ◽  
Type A ◽  
The Other ◽  
Activation Mechanism ◽  
Blood Samples ◽  
Influence Of Temperature ◽  
Stable Type ◽  
High Level

Summary1. The mechanism of the activation of plasmin in blood after intravenous injection of bacterial pyrogens was studied.2. There was plasmin and an activator present in the spontaneous lytic blood samples. In cases with a high level of plasmin a low amount of plasminogen was found and vice versa.3. There seem to be two mechanisms of activation. In the most cases the activator has the properties of a fibrinokinase. In the other type a fibrinolysokinase was found.4. The resistence of the activator against changes in pH and influence of temperature was studied. It was found that the activator was very resistent at acid pH, and, therefore, it shoud be classified as a stable type activator. In addition to this a small amount of a labile type activator seems to be present.5. Some fibrinolytic activity develops in vitro if the pyrogens are incubated with cell-containing plasma or blood. It is supposed that the leucocytes are involved in the activation mechanism.

Efficacy of a ciprofloxacin/amikacin combination against planktonic and biofilm cultures of susceptible and low-level resistant Pseudomonas aeruginosa

2019 ◽  
Vol 74 (11) ◽  
pp. 3252-3259 ◽  
Author(s):  
Anaïs Soares ◽  
Kévin Alexandre ◽  
Fabien Lamoureux ◽  
Ludovic Lemée ◽  
François Caron ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Bacterial Biofilm ◽  
The Other ◽  
Clinical Strain ◽  
Bacterial Reduction ◽  
Low Level ◽  
Mechanical Dispersion ◽  
Resistant Mutants ◽  
High Level

Abstract Background Eradicating bacterial biofilm without mechanical dispersion remains a challenge. Combination therapy has been suggested as a suitable strategy to eradicate biofilm. Objectives To evaluate the efficacy of a ciprofloxacin/amikacin combination in a model of in vitro Pseudomonas aeruginosa biofilm. Methods The antibacterial activity of ciprofloxacin and amikacin (alone, in combination and successively) was evaluated by planktonic and biofilm time–kill assays against five P. aeruginosa strains: PAO1, a WT clinical strain and three clinical strains overexpressing the efflux pumps MexAB-OprM (AB), MexXY-OprM (XY) and MexCD-OprJ (CD), respectively. Amikacin MIC was 16 mg/L for XY and ciprofloxacin MIC was 0.5 mg/L for CD. The other strains were fully susceptible to ciprofloxacin and amikacin. The numbers of total and resistant cells were determined. Results In planktonic cultures, regrowth of high-level resistant mutants was observed when CD was exposed to ciprofloxacin alone and XY to amikacin alone. Eradication was obtained with ciprofloxacin or amikacin in the other strains, or with the combination in XY and CD strains. In biofilm, bactericidal reduction after 8 h followed by a mean 4 log10 cfu/mL plateau in all strains and for all regimens was noticed. No regrowth of resistant mutants was observed whatever the antibiotic regimen. The bacterial reduction obtained with a second antibiotic used simultaneously or consecutively was not significant. Conclusions The ciprofloxacin/amikacin combination prevented the emergence of resistant mutants in low-level resistant strains in planktonic cultures. Biofilm persister cells were not eradicated, either with monotherapy or with the combination.

C1-Inactivator as a Determining Factor in Contact Activation of Fibrinolysis

1975 ◽  
Author(s):  
C. Kluft
Keyword(s):  
Fibrinolytic Activity ◽  
Slow Rate ◽  
Contact Activation ◽  
Activation Rate ◽  
Activity Generation ◽  
High Level ◽  
Fletcher Factor ◽  
Determining Factor

The rate of contact activation of fibrinolysis is considered to reflect the activation rate of proactivator and Hageman factor. This study was undertaken to determine the role of Cl-inactivator in this process.Contact activation of fibrinolysis was performed according to Ogston et al. (1969), J. Clin. Invest. 48, 1786-1801. The rate of activity generation was measured in plasma with various levels of Cl-inactivator and appeared to be dependent on that level; i.e., a high level of Cl-inactivator corresponds with a slow rate of activity generation.It has recently been demonstrated that the fibrinolytic activity of euglobulin fractions is strongly inhibited by Cl-inactivator also present in this fraction. The activity generation of contact activation is found to be accompanied by a gradual decrease in functional Cl-inactivator in the euglobulin fraction. The fibrinolytic activity is set free by this disappearance of inhibition.It is concluded that the rate of contact activation of fibrinolysis must be interpreted in terms of the inactivation of Cl-inactivator rather than of the activation of proenzymes. All enzymes capable of inactivating Cl-inactivator can contribute to the process of contact activation of fibrinolysis. This mechanism might account for the observed defects in fibrinolysis in vitro in Fletcher Factor deficient patients.

THE PROTECTIVE EFFECT OF ACYLATI0N ON THE STABILITY OF EMINASE (APSAC) IN HUMAN PLASMA

1987 ◽  
Author(s):  
R Fears ◽  
H Ferres ◽  
R Standring
Keyword(s):  
Protective Effect ◽  
Human Plasma ◽  
Fibrinolytic Activity ◽  
Animal Studies ◽  
Active Form ◽  
Α2 Macroglobulin ◽  
The Stability ◽  
High Level ◽  
Activator Complex

Clinical and animal studies indicate that APSAC (anisoylated plasminogen.streptokinase activator complex, Eminase) circulates longer in the bloodstream in an active form than the other thrombolytics. In the present studies in vitro u/e have found that functional activity of APSAC is maintained in human plasma longer than that of SK.plasmin(ogen): the relative stability half-lives are similar to the plasma clearance haif-lives in patients. Some of the loss of activity of SK at early times can be attributed to neutralisation by inhibitors. Thus, the survival of fibrinolytically-active SK was promoted in plasma depleted in α2-antiplasmin (α2AP) and α2AP-SK.plasmin complexes (detected by immunoblotting) formed rapidly in normal plasma. Corresponding studies with α2 macroglobulin-depleted plasma suggested a slight, late influence on SK activity but the inhibitor complex has not been detected unequivocally. In addition, loss of SK activity can be attributed, in part, to. rapid degradation to low molecular products. The degradation of SK in APSAC was much slower. In other comparative studies, the stability of APSAC was found to be similar to the stability of prourokinase and much superior to that of SK which is similar to UK; t-PA is intermediate in stability.Maintenance of fibrinolytic activity vivo depends on the stability of the thrombolytic, its rate of clearance and mode of administration. The protective effect of acylation, demonstrated in these experiments, explains why the objective of maintaining a high level of fibrinolytic activity after intravenous bolus injection of APSAC is less compromised by opposing inactivation processes.

scholarly journals Chromosomally and Extrachromosomally Mediated High-Level Gentamicin Resistance in Streptococcus agalactiae

2016 ◽  
Vol 60 (3) ◽  
pp. 1702-1707 ◽  
Author(s):  
Parham Sendi ◽  
Martina Furitsch ◽  
Stefanie Mauerer ◽  
Carlos Florindo ◽  
Barbara C. Kahl ◽  
...  
Keyword(s):  
Synergistic Effect ◽  
Streptococcus Agalactiae ◽  
Molecular Mechanisms ◽  
The Other ◽  
Content Type ◽  
Gentamicin Resistance ◽  
Group B ◽  
High Level ◽  
Plasmid Purification

Streptococcus agalactiae(group BStreptococcus[GBS]) is a leading cause of sepsis in neonates. The rate of invasive GBS disease in nonpregnant adults also continues to climb. Aminoglycosides alone have little or no effect on GBS, but synergistic killing with penicillin has been shownin vitro. High-level gentamicin resistance (HLGR) in GBS isolates, however, leads to the loss of a synergistic effect. We therefore performed a multicenter study to determine the frequency of HLGR GBS isolates and to elucidate the molecular mechanisms leading to gentamicin resistance. From eight centers in four countries, 1,128 invasive and colonizing GBS isolates were pooled and investigated for the presence of HLGR. We identified two strains that displayed HLGR (BSU1203 and BSU452), both of which carried theaacA-aphDgene, typically conferring HLGR. However, only one strain (BSU1203) also carried the previously described chromosomal gentamicin resistance transposon designated Tn3706. For the other strain (BSU452), plasmid purification and subsequent DNA sequencing resulted in the detection of plasmid pIP501 carrying a remnant of a Tn3family transposon. Its ability to confer HLGR was proven by transfer into anEnterococcus faecalisisolate. Conversely, loss of HLGR was documented after curing both GBS BSU452 and the transformedE. faecalisstrain from the plasmid. This is the first report showing plasmid-mediated HLGR in GBS. Thus, in our clinical GBS isolates, HLGR is mediated both chromosomally and extrachromosomally.

Effect of short-term dietary administration of eugenol in humans

1996 ◽  
Vol 15 (2) ◽  
pp. 129-135 ◽  
Author(s):  
Cjm Rompelberg ◽  
Jtwe Vogels ◽  
N. de Vogel ◽  
Gcdm Bruijntjes-Rozier ◽  
WH Stenhuis ◽  
...  
Keyword(s):  
Biochemical Parameters ◽  
White Blood Cells ◽  
The Other ◽  
Test Substance ◽  
Glutathione S Transferase ◽  
Short Term ◽  
Blood Samples ◽  
Placebo Period ◽  
Daily Amount

1 In order to study the antigenotoxic potential of eugenol in humans, ten healthy non-smoking males ingested a daily amount of 150 mg eugenol or the placebo for seven consecutive days. After a washout period of one week, groups ingesting eugenol or the placebo were crossed and received the other treatment for seven consecutive days. 2 On days 8 and 22 blood samples were taken for the assessment of standard clinical biochemical parameters. To study the possible antigenotoxic effect of eugenol, on day 8 and 22 blood samples were collected and exposed in vitro to the established genotoxic agents mitomycin C and vinblastine. After exposure the percentage of cells with chromosome aberrations and micronuclei was deter mined in cultured white blood cells. On days 8 and 22 paracetamol (500 mg p.o.) was administered as test substance to measure phase-II biotransformation capa city. Glutathione-S-transferase (GST) activities were determined in erythrocytes and blood plasma. 3 No significant differences in the clinical biochemical parameters were detected between the eugenol-period and the placebo-period, indicating that daily administration of 150 mg eugenol for 7 days has no toxic affects. 4 No significant differences on the cytogenetic para meters were found after ingestion of eugenol. Thus, there are no indications for an antigenotoxic potential of eugenol in humans, consuming daily 150 mg eugenol for 7 days. 5 A significant reduction in α-class GSTs in plasma (P<0.05), but not in the other measured biotransformation parameters, was found in volunteers during the eugenol- period as compared to the placebo-period. This may either reflect GST-inhibition by eugenol or protection against background damage of liver cells by eugenol.

Experiments on rumen retention time, fermentation rate and dry-matter digestibility in zebu and european-type cattle on a grass hay ration

1960 ◽  
Vol 54 (3) ◽  
pp. 417-420 ◽  
Author(s):  
G. D. Phillips ◽  
R. E. Hungate ◽  
A. MacGregor ◽  
D. P. Hungate
Keyword(s):  
Retention Time ◽  
Dry Matter ◽  
Rumen Fermentation ◽  
The Other ◽  
Fermentation Products ◽  
Fermentation Rate ◽  
Dry Matter Digestibility ◽  
Two Factors ◽  
High Level

1. Experiments are described in which retention time of digesta in the reticulo-rumen, fermentation rates of rumen contents, and dry-matter digestibilities were studied simultaneously in four grade European and three zebu steers.2. Fermentation rates and rumen retentions were significantly negatively correlated.3. Correlations between digestibility and the other two factors were not significant at a high level.4. The multiple regressions calculated for retention time and fermentation rate were significant at the 5% level and that for digestibility approached this level.5. While only fermentation rates show significant differences for the two types of cattle, the results suggest that grades and zebus differ also in the rate of passage of digesta through the rumen.6. The loss in weight of substrate per unit of fermentation products was measured inin vitroexperiments.7. Using certain assumptions, estimates are made of the extent to which the measured fermentation rates could account for the loss in weight of dry matter during digestion, and are compared with the loss actually found.

In vitro efficacy of essential oils and extracts of Schinus molle L. against Ctenocephalides felis felis.

Parasitology ◽  
2016 ◽  
Vol 143 (5) ◽  
pp. 627-638 ◽  
Author(s):  
LILIAN C. DE S. O. BATISTA ◽  
YARA P. CID ◽  
ANA PAULA DE ALMEIDA ◽  
EDLENE R. PRUDÊNCIO ◽  
CRISTIANO J. RIGER ◽  
...  
Keyword(s):  
Essential Oil ◽  
Essential Oils ◽  
Ctenocephalides Felis ◽  
The Other ◽  
Natural Sources ◽  
Ctenocephalides Felis Felis ◽  
Schinus Molle ◽  
Veterinary Importance ◽  
High Level

SUMMARYExtracts and essential oils from plants are important natural sources of pesticides. These compounds are considered an alternative to control ectoparasites of veterinary importance. Schinus molle, an endemic species of Brazil, produces a high level of essential oil and several other compounds. The aim of this work was to determinate the chemical composition of extracts and essential oils of S. molle and further to evaluate the activity against eggs and adults of Ctenocephalides felis felis, a predominant flea that infests dogs and cats in Brazil. In an in vitro assay, the non-polar (n-hexane) extract showed 100% efficacy (800 µg cm−2; LD50 = 524·80 µg cm−2) at 24 and 48 h. Its major compound was lupenone (50·25%). Essential oils from fruits and leaves were evaluated, and had 100% efficacy against adult fleas at 800 µg cm−2 (LD50 = 353·95 µg cm−2) and at 50 µg cm−2 (LD50 = 12·02 µg cm−2), respectively. On the other hand, the essential oil from fruits and leaves was not active against flea eggs. This is the first study that reports the insecticidal effects of essential oils and extracts obtained from Schinus molle against Ctenocephalides felis felis.

A comparative study on the conditions of growth and sporulation of three strains of Clostridium petfringens type A

1996 ◽  
Vol 42 (3) ◽  
pp. 298-304 ◽  
Author(s):  
Mathilde Decaudin ◽  
Jean-Luc Tholozan
Keyword(s):  
Clostridium Perfringens ◽  
Slow Growth ◽  
Type A ◽  
High Volume ◽  
The Other ◽  
Additional Information ◽  
Mutant Strains ◽  
Dependent Strain ◽  
Kinetics Of

Different conditions of growth and sporulation of a strain of Clostridium perfringens type A (NCTC 8798) and two derived mutant strains, the lysozyme-germination dependent strain 8-6 and the revertant strain R3, have been determined. No sporulation was detected for the three strains in the Duncan and Strong (DS) medium; 100% sporulation was routinely obtained for the two mutant strains in the defined (D) medium. Factors promoting in vitro sporulation of C. perfringens type A were assayed: the volume of the culture, the type of preculture, and the addition of lysozyme in precultures. The paper also provides additional information on growth and sporulation of the mutant strains 8-6 and R3. Glucose concentrations up to 11 mM produced high percentages of sporulation. However, strain R3 still sporulated at 20% with 56 mM of glucose. A high volume of D medium led to slow growth kinetics and favoured sporulation. Faster kinetics of growth and the best percentage of sporulation were obtained with a young inoculum of the two mutant strains. On the other hand, the type of medium in the preculture (fluid thioglycollate (FTG) or basal carbonate yeast trypticase (BCYT)) did not influence the percentage of sporulation. However, while strain R3 was not affected by the addition of lysozyme in D medium, kinetics of growth were strongly influenced by this addition in strain 8-6, and the percentage of sporulation increased with a preculture in FTG medium and decreased when BCYT medium was used.Key words: Clostridium perfringens, medium, growth, sporulation.

scholarly journals Comparative study of juvenility resulting from in vitro propagated Vitis vinifera L., cv. Albariño vines when subjected to different pruning systems

OENO One ◽  
1994 ◽  
Vol 28 (2) ◽  
pp. 111
Author(s):  
María-Carmen Martínez ◽  
José Luis González Mantilla
Keyword(s):  
Comparative Study ◽  
Vitis Vinifera ◽  
Middle Level ◽  
The Other ◽  
Anthocyanin Pigmentation ◽  
Total Absence ◽  
First Case ◽  
Vegetative Cycle ◽  
High Level

<p style="text-align: justify;">Plants of <em>Vitis vinifera</em> L., cv. Albariño propagated <em>in vitro</em> were planted on their own roots and subjected to three different pruning systems, one at high level (Crosstree cordon system), one at middle level (Sylvoz system) and one at low level (Royat cordon system). Ampelographic and ampelometric characters were studied in different organs of these vines at several periods of the vegetative cycle during the 4th and 5th year.</p><p style="text-align: justify;">ln the 4th year, although the vines from the Crosstree cordon system were slightly different, all of them showed very similar characteristics, such as: leaves with deep lateral sinuses, anthocyanin pigmentation of buds, and of the dorsal face of the nodes and internodes, presence of erect hairs on the young and adult leaves and, above all, on the margin of the dentation. These features were less noticeable in leaves on the Crosstree cordon system. Flowering during the 4th year was limited resulting in the production of a low number of small grape clusters. In the high cordon system, the level of f1owering was slightly better.</p><p style="text-align: justify;">During the 5th year, a very marked difference was observed between the vines subjected to the Crosstree high cordon pruning system and those subjected to the other two systems. In the first case, the leaves show an almost total absence of erect hairs and lateral sinuses, and the number and the size of grape clusters increase significantly. The vines from Sylvoz and cordon Royat continued practically to appear the same as the previous year and flowering continued to be almost absent.</p>

Downmodulation of IL-8 receptors, type A and type B, on human lung neutrophils in vivo

1997 ◽  
Vol 273 (3) ◽  
pp. L618-L625 ◽  
Author(s):  
K. Soejima ◽  
S. Fujishima ◽  
H. Nakamura ◽  
Y. Waki ◽  
M. Nakamura ◽  
...  
Keyword(s):  
Peripheral Blood ◽  
Type A ◽  
Type B ◽  
Low Level ◽  
Blood Neutrophils ◽  
Vitro Analysis ◽  
High Level ◽  
In Vitro Analysis

We examined the expression of interleukin (IL)-8 receptors (Rs), type A (IL-8-RA) and type B (IL-8-RB), on peripheral blood and bronchoalveolar lavage (BAL) fluid neutrophils; we also examined IL-8 and other chemoattractants in the epithelial lining fluid (ELF) of patients with chronic lower respiratory tract infection (CLI) to elucidate the in vivo regulation of IL-8Rs. Neutrophils were stained with monoclonal antibodies specific for IL-8-RA and IL-8-RB. We detected higher levels of IL-8 (81.6 +/- 25.4 ng/ml, mean +/- SE), leukotriene (LT) B4, and IL-1 beta in the ELF of the CLI patients than in their serum (P < 0.05). The expression of IL-8Rs on BAL neutrophils was significantly lower than that on peripheral blood neutrophils (P < 0.01 for both). In vitro analysis showed that low-level IL-8 (50 ng/ml) alone did not affect IL-8R expression but that it was downregulated by high-level IL-8 (500 ng/ml) alone and by low-level IL-8 in combination with LTB4 or IL-1 beta. Staurosporine reduced the downmodulation by low-level IL-8 plus LTB4 or IL-1 beta but not by high-level IL-8 alone. We speculate that pulmonary IL-8-RA and IL-8-RB may have been downmodulated by the combined effect of local chemoattractants through, in part, a protein kinase C-dependent mechanism.

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