A low molecular weight glycosaminoglycan from the human aorta

1977 ◽  
Vol 33 (10) ◽  
pp. 1282-1283 ◽  
Author(s):  
R. L. Stevens ◽  
J. P. Binette ◽  
A. Kimura ◽  
R. B. Nimberg ◽  
K. Schmid
Keyword(s):  
Molecular Weight ◽  
Human Aorta ◽  
Low Molecular Weight

Elastin-derived peptide binding to a hydrophobic domain on neutrophil elastase

1994 ◽  
Vol 72 (9-10) ◽  
pp. 419-427 ◽  
Author(s):  
Suresh C. Tyagi ◽  
Sanford R. Simon
Keyword(s):  
Molecular Weight ◽  
Neutrophil Elastase ◽  
Protein Fraction ◽  
Competitive Inhibition ◽  
Hydrophobic Interactions ◽  
Human Aorta ◽  
Low Molecular Weight ◽  
Human Neutrophil Elastase ◽  
Amidolytic Activity ◽  
Hydrophobic Domain

To understand the contributions of binding of elastin to domains removed from the active site of neutrophil elastase, we isolated an elastin-derived peptide (EDP) fraction, which we have previously shown was tightly linked to neutrophil elastase after prolonged digestion of elastin but which can be released from the enzyme with hydroxylamine. Elastin from human aorta was incubated with human neutrophil elastase under conditions favoring proteolysis. Low molecular weight species, including free EDP, were separated from the protein fraction by a small centrifuged gel filtration column. The high molecular weight protein fraction was subjected directly to 0.5 M hydroxylamine. The reaction mixture was then fractionated on a phosphocellulose column using an ionic gradient. A fraction was collected that exhibited fluorescence with a peak at ~410 nm when excited at 320 nm, indicating the presence of desmosine and (or) isodesmosine. A second peak with amidolytic activity towards methoxysuccinyl-Ala-Ala-Pro-Val-p-nitroaniline (MeOSucAAPVpNa), but no fluorescence at 410 nm was also detected at the same elution volume where free elastase appeared. After removal of low molecular weight digestion products but prior to treatment with hydroxylamine, the putative elastase–EDP complex possessed no amidolytic activity towards MeOSucAAPVpNa. When the liberated EDP was added to elastase in an amidolytic assay, the EDP behaved as only a partial noncompetitive inhibitor [Formula: see text], but bound with high affinity to neutrophil elastase [Formula: see text], as detected by its ability to quench elastase endogenous fluorescence. The complete emission spectrum of the mixture of elastase and EDP obtained at excitation wavelengths specific for tryptophan and desmosine/isodesmosine suggests that the EDP was in a hydrophobic environment which was close to at least one of the three tryptophan residues in the enzyme. Based on fluorescence energy transfer, we have estimated a distance between the elastase and EDP of ~10 ± 3 Å (1 Å = 0.1 nm) during elastinolysis. This pattern of binding to a hydrophobic site on neutrophil elastase without competitive inhibition of amidolytic activity was consistent with the importance of hydrophobic interactions between neutrophil elastase and elastin within a region of the enzyme removed from the active site.Key words: proteinase, elastase, elastin, extracellular matrix, elastin-derived peptide.

A high-performance oil-free backing pump for electron microscopes

1978 ◽  
Vol 36 (1) ◽  
pp. 110-111
Author(s):  
G.K.W. Balkau ◽  
E. Bez ◽  
J.L. Farrant
Keyword(s):  
Molecular Weight ◽  
Electron Microscope ◽  
Hot Spots ◽  
High Performance ◽  
Carbonaceous Material ◽  
Contamination Rate ◽  
Low Molecular Weight ◽  
Principal Source ◽  
Rotary Pumps ◽  
Electron Microscopes

The earliest account of the contamination of electron microscope specimens by the deposition of carbonaceous material during electron irradiation was published in 1947 by Watson who was then working in Canada. It was soon established that this carbonaceous material is formed from organic vapours, and it is now recognized that the principal source is the oil-sealed rotary pumps which provide the backing vacuum. It has been shown that the organic vapours consist of low molecular weight fragments of oil molecules which have been degraded at hot spots produced by friction between the vanes and the surfaces on which they slide. As satisfactory oil-free pumps are unavailable, it is standard electron microscope practice to reduce the partial pressure of organic vapours in the microscope in the vicinity of the specimen by using liquid-nitrogen cooled anti-contamination devices. Traps of this type are sufficient to reduce the contamination rate to about 0.1 Å per min, which is tolerable for many investigations.

Low-molecular-weight heparin in the prevention and treatment of thromboembolic disorders

1998 ◽  
Vol 1 (5) ◽  
pp. 166-174 ◽  
Author(s):  
Evelyn R Hermes De Santis ◽  
Betsy S Laumeister ◽  
Vidhu Bansal ◽  
Vandana Kataria ◽  
Preeti Loomba ◽  
...  
Keyword(s):  
Molecular Weight ◽  
Low Molecular Weight Heparin ◽  
Low Molecular Weight ◽  
Prevention And Treatment

Venous thromboembolism in a general hospital. An update with low molecular weight heparin prophylaxis

VASA ◽  
2007 ◽  
Vol 36 (1) ◽  
pp. 17-22
Author(s):  
Schulz ◽  
Kesselring ◽  
Seeberger ◽  
Andresen
Keyword(s):  
Molecular Weight ◽  
Pulmonary Embolism ◽  
Venous Thromboembolism ◽  
Low Molecular Weight ◽  
Trauma Patients ◽  
Vte Prophylaxis ◽  
Vein Thrombosis ◽  
Patients At Risk ◽  
Hospital Stays ◽  
Event Rates

Background: Patients admitted to hospital for surgery or acute medical illnesses have a high risk for venous thromboembolism (VTE). Today’s widespread use of low molecular weight heparins (LMWH) for VTE prophylaxis is supposed to have reduced VTE rates substantially. However, data concerning the overall effectiveness of LMWH prophylaxis is sparse. Patients and methods: We prospectively studied all patients with symptomatic and objectively confirmed VTE seen in our hospital over a three year period. Event rates in different wards were analysed and compared. VTE prophylaxis with Enoxaparin was given to all patients at risk during their hospital stay. Results: A total of 50 464 inpatients were treated during the study period. 461 examinations were carried out for symptoms suggestive of VTE and yielded 89 positive results in 85 patients. Seventy eight patients were found to have deep vein thrombosis, 7 had pulmonary embolism, and 4 had both deep venous thrombosis and pulmonary embolism. The overall in hospital VTE event rate was 0.17%. The rate decreased during the study period from 0.22 in year one to 0,16 in year two and 0.13 % in year three. It ranged highest in neurologic and trauma patients (0.32%) and lowest (0.08%) in gynecology-obstetrics. Conclusions: With a simple and strictly applied regimen of prophylaxis with LMWH the overall rate of symptomatic VTE was very low in our hospitalized patients. Beside LMWH prophylaxis, shortening hospital stays and substantial improvements in surgical and anasthesia techniques achieved during the last decades probably play an essential role in decreasing VTE rates.

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