Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 12 de 12
Filter
Add more filters










Publication year range
1.
Ultramicroscopy ; 257: 113904, 2024 Mar.
Article in English | MEDLINE | ID: mdl-38061278

ABSTRACT

Interfacial phenomena between active cathode materials and solid electrolytes play an important role in the function of solid-state batteries. (S)TEM imaging can give valuable insight into the atomic structure and composition at the various interfaces, yet the preparation of TEM specimen by FIB (focused ion beam) is challenging for loosely bound samples like composites, as they easily break apart during conventional preparation routines. We propose a novel preparation method that uses a frame made of deposition layers from the FIB's gas injection system to prevent the sample from breaking apart. This technique can of course be also applied to other loosely bound samples, not only those in the field of batteries.

2.
Knee Surg Sports Traumatol Arthrosc ; 21(3): 564-70, 2013 Mar.
Article in English | MEDLINE | ID: mdl-22965381

ABSTRACT

PURPOSE: Magnetic resonance imaging (MRI) provides sufficient information with regard to specific soft-tissue injuries in the knee, but it is not generally used to evaluate acute tibial plateau fractures. The aim of the present study was to determine whether the amount of tibial plateau fracture depression on multi-detector computed tomography (MDCT) scans correlates with the incidence of associated soft-tissue injuries on MRI. METHODS: A total of 54 consecutive patients with a mean age of 51.2 years (SD = 18.3) were included in this retrospective study. All patients were admitted to the emergency department of a university clinic with acute tibial plateau fracture. The amount of articular depression was assessed from MDCT scans. Magnetic resonance images were evaluated for crucial and collateral ligament injury, meniscal tears, and patellar retinaculum lesions. RESULTS: Logistic regression revealed a significant impact of increasing tibial plateau fracture depression on the incidence of meniscus lateralis tears (P = 0.025) and anterior cruciate ligament lesions (P = 0.018). Analysis of covariance demonstrated a significant correlation between the amount of articular depression and absolute number of soft-tissue injuries (P = 0.001). CONCLUSIONS: Articular depression is a potential predictor of specific meniscal and ligamentous injuries in acute tibial plateau fracture. Magnetic resonance imaging is generally recommended with respect to associated soft-tissue injuries, especially in cases with distinct tibial plateau fracture depression on multi-detector computed tomography scans. LEVEL OF EVIDENCE: Case series, Level IV.


Subject(s)
Soft Tissue Injuries/diagnosis , Tibial Fractures/diagnosis , Female , Humans , Magnetic Resonance Imaging , Male , Middle Aged , Multidetector Computed Tomography , Retrospective Studies
3.
Bioorg Med Chem ; 15(3): 1311-22, 2007 Feb 01.
Article in English | MEDLINE | ID: mdl-17127070

ABSTRACT

Peptidomimetic compounds possessing a caprolactam ring constraint were prepared and evaluated as interleukin-1beta converting enzyme (ICE) inhibitors. The caprolactam ring was used to constrain the P3 region of our inhibitors. This strategy proved to be effective for the synthesis of ICE inhibitors, maintaining key hydrogen bond interactions with the enzyme and invoking a preferred conformation for binding. Several compounds exhibited IC(50) values less than 10nM in a caspase-1 enzyme assay and less than 100nM in a THP-1 whole cell assay measuring IL-1beta production. Two compounds, 13c and 13j, were found to have good oral bioavailability (>50%) in rats when administered as prodrugs.


Subject(s)
Caprolactam/chemical synthesis , Caspase Inhibitors , Enzyme Inhibitors/pharmacology , Serpins/chemical synthesis , Viral Proteins/chemical synthesis , Animals , Biological Availability , Caprolactam/chemistry , Caprolactam/pharmacology , Crystallography, X-Ray , Enzyme Inhibitors/chemical synthesis , Enzyme Inhibitors/chemistry , Hydrogen Bonding , Interleukin-1beta/metabolism , Male , Models, Molecular , Molecular Conformation , Molecular Structure , Rats , Rats, Sprague-Dawley , Serpins/pharmacology , Structure-Activity Relationship , Viral Proteins/pharmacology
4.
Bioorg Med Chem ; 14(23): 7880-92, 2006 Dec 01.
Article in English | MEDLINE | ID: mdl-16908171

ABSTRACT

An 8,5-fused bicyclic peptidomimetic ring system generated by a stereoselective ring metathesis reaction was elaborated into potent inhibitors of interleukin-1beta converting enzyme (ICE, caspase-1). Multiple compounds were found that exhibited ICE IC50 values < 10 nM and were selective over caspase-3 and caspase-8. These active analogs generally possessed good activity (IC50 values < 100 nM) in a whole cell assay measuring IL-1beta production. Pharmacokinetic analysis of the ethyl acetal prodrug form of a selected active lead revealed a compound with a reasonable plasma half-life (1.1 h) and good oral bioavailability (30%).


Subject(s)
Bridged Bicyclo Compounds, Heterocyclic/pharmacology , Caspase Inhibitors , Peptides, Cyclic/pharmacology , Animals , Biological Availability , Bridged Bicyclo Compounds, Heterocyclic/chemical synthesis , Enzyme Inhibitors/chemical synthesis , Enzyme Inhibitors/pharmacokinetics , Enzyme Inhibitors/pharmacology , Half-Life , Inhibitory Concentration 50 , Molecular Mimicry , Peptides, Cyclic/chemical synthesis , Prodrugs/pharmacokinetics , Structure-Activity Relationship , Substrate Specificity
5.
Bioorg Med Chem Lett ; 16(21): 5659-63, 2006 Nov 01.
Article in English | MEDLINE | ID: mdl-16919947

ABSTRACT

The synthesis and structure-activity relationships of a novel series of N-sulfonyl-2-indole carboxamides that bind to peroxisome proliferator-activated receptor gamma (PPAR-gamma) are reported. Chemical optimization of the series led to the identification of 4q (IC(50)=50 nM) as a potent binding agent of PPAR-gamma. Also reported is preliminary cell based data suggesting the use of these compounds in the treatment of osteoporosis.


Subject(s)
Amides/pharmacology , Drug Design , Indoles/pharmacology , Osteoporosis/drug therapy , PPAR gamma/metabolism , 3T3 Cells , Amides/chemical synthesis , Animals , Indoles/chemical synthesis , Mice
6.
Bioorg Med Chem Lett ; 16(18): 4728-32, 2006 Sep 15.
Article in English | MEDLINE | ID: mdl-16870441

ABSTRACT

A series of monocyclic thiazepine inhibitors of interleukin-1beta converting enzyme (ICE) were synthesized in eight steps from commercially available intermediates. In vitro biological evaluation showed the thiazepines to be moderately potent ICE inhibitors, with the most active compound exhibiting an IC50 value of 30 nM in an enzyme inhibition assay. Compounds of this class possessed good selectivity against the related enzymes caspase-3 and caspase-8.


Subject(s)
Caspase Inhibitors , Enzyme Inhibitors/chemical synthesis , Enzyme Inhibitors/pharmacology , Thiazepines/chemical synthesis , Thiazepines/pharmacology , Caspase 1/metabolism , Crystallography, X-Ray , Enzyme Inhibitors/chemistry , Inhibitory Concentration 50 , Models, Molecular , Molecular Structure , Structure-Activity Relationship , Thiazepines/chemistry
7.
Bioorg Med Chem Lett ; 16(16): 4233-6, 2006 Aug 15.
Article in English | MEDLINE | ID: mdl-16782334

ABSTRACT

Novel 1-(2-acylhydrazinocarbonyl)cycloalkyl carboxamides were designed as peptidomimetic inhibitors of interleukin-1beta converting enzyme (ICE). A short synthesis was developed and moderately potent ICE inhibitors were identified (IC(50) values <100 nM). Most of the synthesized examples were selective for ICE versus the related cysteine proteases caspase-3 and caspase-8, although several dual-acting inhibitors of ICE and caspase-8 were identified. Several of the more potent ICE inhibitors were also shown to inhibit IL-1beta production in a whole cell assay (IC(50) < 500 nM).


Subject(s)
Amides/chemical synthesis , Amides/pharmacology , Aminoimidazole Carboxamide/chemical synthesis , Caspase Inhibitors , Hydrazines/chemical synthesis , Hydrazines/pharmacology , Aminoimidazole Carboxamide/analogs & derivatives , Caspase 8 , Chemistry, Pharmaceutical/methods , Cysteine Endopeptidases/metabolism , Drug Industry/methods , Drug Screening Assays, Antitumor , Enzyme Inhibitors/pharmacology , Humans , Inhibitory Concentration 50 , Models, Chemical
8.
Bioorg Med Chem Lett ; 15(24): 5434-8, 2005 Dec 15.
Article in English | MEDLINE | ID: mdl-16216507

ABSTRACT

Two novel 8,6-fused bicyclic peptidomimetic ring systems were synthesized utilizing olefin metathesis as the key reaction for the formation of the eight-membered ring. Both peptidomimetic scaffolds were further elaborated into potent ICE inhibitors, with numerous compounds exhibiting caspase-1 IC(50)s less than 10nM.


Subject(s)
Biomimetics , Bridged Bicyclo Compounds, Heterocyclic/pharmacology , Caspase Inhibitors , Enzyme Inhibitors/pharmacology , Bridged Bicyclo Compounds, Heterocyclic/chemical synthesis , Enzyme Inhibitors/chemical synthesis , Humans , Indicators and Reagents , Models, Molecular , Molecular Conformation
9.
Bioorg Med Chem Lett ; 15(19): 4291-4, 2005 Oct 01.
Article in English | MEDLINE | ID: mdl-16046125

ABSTRACT

A novel diazocan containing dipeptide mimetic was synthesized via reductive N-N bond cleavage of a pyrazolidino-pyrazolidine using Raney-Ni and evaluated as an ICE inhibitor. This versatile 8-membered ring containing scaffold possesses an N-5 ring nitrogen that was used to explore structure-activity relationships in a cell-based assay measuring inhibition of interleukin-1beta.


Subject(s)
Dipeptides/chemical synthesis , Interleukin-1/antagonists & inhibitors , Peptides, Cyclic/chemical synthesis , Caspase Inhibitors , Dipeptides/chemistry , Dipeptides/pharmacology , Drug Evaluation, Preclinical , Inhibitory Concentration 50 , Interleukin-1/biosynthesis , Molecular Conformation , Molecular Mimicry , Peptides, Cyclic/chemistry , Peptides, Cyclic/pharmacology , Pyrazoles/chemistry , Structure-Activity Relationship
10.
Bioorg Med Chem Lett ; 15(19): 4322-6, 2005 Oct 01.
Article in English | MEDLINE | ID: mdl-16046129

ABSTRACT

The application of a tricyclic pyrrolopyrimidinone scaffold for the synthesis of peptidomimetic inhibitors of interleukin-1beta-converting enzyme (ICE) is reported. The synthesis of the tricyclic scaffold and conversion of it to a variety of target ICE inhibitors were accomplished in 4-5 steps. In vitro biological evaluation of the tricyclic pyrrolopyrimidinones revealed fair to good ICE inhibitors, with the most active compound exhibiting an IC50 of 14 nM in a caspase-1 enzyme binding assay.


Subject(s)
Caspase Inhibitors , Dipeptides/chemical synthesis , Pyrimidinones/chemical synthesis , Dipeptides/pharmacology , Enzyme Inhibitors/chemical synthesis , Enzyme Inhibitors/pharmacology , Heterocyclic Compounds, 3-Ring/chemical synthesis , Heterocyclic Compounds, 3-Ring/pharmacology , Humans , Immunologic Factors/chemical synthesis , Immunologic Factors/pharmacology , Inhibitory Concentration 50 , Molecular Mimicry , Monocytes , Pyrimidinones/pharmacology , Pyrroles/chemical synthesis , Pyrroles/pharmacology , Structure-Activity Relationship
11.
Antimicrob Agents Chemother ; 48(3): 961-9, 2004 Mar.
Article in English | MEDLINE | ID: mdl-14982790

ABSTRACT

Several non-beta-lactam compounds were active against various gram-positive and gram-negative bacterial strains. The MICs of arylalkylidene rhodanines and arylalkylidene iminothiazolidin-4-ones were lower than those of ampicillin and cefotaxime for methicillin-resistant Staphylococcus aureus MI339 and vancomycin-resistant Enterococcus faecium EF12. Several compounds were found to inhibit the cell wall synthesis of S. aureus and the last two steps of peptidoglycan biosynthesis catalyzed by ether-treated cells of Escherichia coli or cell wall membrane preparations of Bacillus megaterium. The effects of the arylalkylidene rhodanines and arylalkylidene iminothiazolidin-4-one derivatives on E. coli PBP 3 and PBP 5, Streptococcus pneumoniae PBP 2xS (PBP 2x from a penicillin-sensitive strain) and PBP 2xR (PBP 2x from a penicillin-resistant strain), low-affinity PBP 2a of S. aureus, and the Actinomadura sp. strain R39 and Streptomyces sp. strain R61 DD-peptidases were studied. Some of the compounds exhibited inhibitory activities in the 10 to 100 microM concentration range. The inhibition of PBP 2xS by several of them appeared to be noncompetitive. The dissociation constant for the best inhibitor (Ki = 10 microM) was not influenced by the presence of the substrate.


Subject(s)
Alkenes/pharmacology , Bacteria/drug effects , Bacterial Proteins/antagonists & inhibitors , Bacterial Proteins/chemistry , Carrier Proteins/antagonists & inhibitors , Carrier Proteins/chemistry , Hexosyltransferases/antagonists & inhibitors , Hexosyltransferases/chemistry , Muramoylpentapeptide Carboxypeptidase/antagonists & inhibitors , Muramoylpentapeptide Carboxypeptidase/chemistry , Peptidyl Transferases/antagonists & inhibitors , Peptidyl Transferases/chemistry , Rhodanine/pharmacology , Thiazoles/pharmacology , Algorithms , Alkenes/chemistry , Bacillus megaterium/drug effects , Bacillus megaterium/metabolism , Bacillus megaterium/ultrastructure , Bacteria/growth & development , Bacteria/metabolism , Cell Wall/drug effects , Cell Wall/metabolism , Dipeptidyl-Peptidases and Tripeptidyl-Peptidases/antagonists & inhibitors , Escherichia coli/drug effects , Kinetics , Penicillin-Binding Proteins , Peptidoglycan/biosynthesis , Protease Inhibitors/pharmacology , Rhodanine/chemistry , Streptococcus pneumoniae/drug effects , Streptococcus pneumoniae/metabolism , Structure-Activity Relationship , Thiazoles/chemistry
12.
J Biomol Screen ; 8(5): 555-8, 2003 Oct.
Article in English | MEDLINE | ID: mdl-14567782

ABSTRACT

An assay quantifying the loss of antibacterial potency of compounds, originally identified via target-based screening, in the presence of increasing albumin concentration was developed and used as a technique to measure potential association of compounds with proteins unrelated to their molecular target. Minimum inhibitory concentrations (MICs) of test compounds were measured against Staphylococcus aureus strain ATCC 6538 in the presence of 0-12 muM bovine serum albumin (BSA). The linear regression coefficient r(2) for the correlation between MIC and BSA concentration was >/= 0.9 for 49 and > 0.5 for 62 out of a total of 69 compounds tested. The slope of these correlations varied widely from < 1 to 99, suggesting that the loss of potency due to a given concentration of BSA could vary from compound to compound due to wide variation in the apparent stoichiometry for protein-ligand association. Follow-up experiments using additional proteins and a fatty acid, oleic acid, showed that this compound:BSA association was not protein specific, but was likely driven by hydrophobicity. The method described in this report can be used to optimize compound design and minimize this undesirable effect.


Subject(s)
Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/pharmacology , Drug Evaluation, Preclinical/methods , Proteins/metabolism , Anti-Bacterial Agents/metabolism , Dose-Response Relationship, Drug , Linear Models , Microbial Sensitivity Tests , Proteins/drug effects , Serum Albumin, Bovine/drug effects , Serum Albumin, Bovine/metabolism , Staphylococcus aureus/drug effects , Structure-Activity Relationship
SELECTION OF CITATIONS
SEARCH DETAIL
...