Comments by Peter R. Schmidt

Schmidt, Peter R.

doi:10.1007/s11759-010-9138-4

Cited by 4 publications

(9 citation statements)

References 2 publications

(2 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Segment coordinate systems were calculated based on the marker positions with a least-squares algorithm [29]. The joint centers at each instant in time were then calculated based on the position of the joint markers during the static trial (Schmidt et al [30]). Local coordinate systems were then defined using the International Society of Biomechanics' (ISB) recommendations for the humérus and forearm [31] and a modified coordinate system for the trunk [32] and wrist [33].…”

Section: Kinematic Data Capturingmentioning

confidence: 99%

Nonlinear Smooth Orthogonal Decomposition of Kinematic Features of Sawing Reconstructs Muscle Fatigue Evolution as Indicated by Electromyography

Segala

Gates

Dingwell

et al. 2011

Journal of Biomechanical Engineering

View full text Add to dashboard Cite

Tracking or predicting physiological fatigue is important for developing more robust training protocols and better energy supplements and/or reducing muscle injuries. Current methodologies are usually impractical and/or invasive and may not be realizable outside of laboratory settings. It was recently demonstrated that smooth orthogonal decomposition (SOD) of phase space warping (PSW) features of motion kinematics can identify fatigue in individual muscle groups. We hypothesize that a nonlinear extension of SOD will identify more optimal fatigue coordinates and provide a lower-dimensional reconstruction of local fatigue dynamics than the linear SOD. Both linear and nonlinear SODs were applied to PSW features estimated from measured kinematics to reconstruct muscle fatigue dynamics in subjects performing a sawing motion. Ten healthy young right-handed subjects pushed a weighted handle back and forth until voluntary exhaustion. Three sets of joint kinematic angles were measured from the right upper extremity in addition to surface electromyography (EMG) recordings. The SOD coordinates of kinematic PSW features were compared against independently measured fatigue markers (i.e., mean and median EMG spectrum frequencies of individual muscle groups). This comparison was based on a least-squares linear fit of a fixed number of the dominant SOD coordinates to the appropriate local fatigue markers. Between subject variability showed that at most four to five nonlinear SOD coordinates were needed to reconstruct fatigue in local muscle groups, while on average 15 coordinates were needed for the linear SOD. Thus, the nonlinear coordinates provided a one-order-of-magnitude improvement over the linear ones.

show abstract

Section: Kinematic Data Capturingmentioning

confidence: 99%

Nonlinear Smooth Orthogonal Decomposition of Kinematic Features of Sawing Reconstructs Muscle Fatigue Evolution as Indicated by Electromyography

Segala

Gates

Dingwell

et al. 2011

Journal of Biomechanical Engineering

View full text Add to dashboard Cite

show abstract

“…In order to obtain information about the toxic effects of the new antagonists. the best inhibitors, I and 11, were examined in the edema assay (6,7) and for acute effects associated with intravenous administration to rats (6) as compared to D1 and A. None of the D-Cit/D-HCi6 antagonists, i.e.…”

Section: Discussionmentioning

confidence: 99%

“…this class of antagonists, when injected S.C. into rats at doses of 1.25-1.5mg1kg. has been found to cause transient edema of the face and extremities (6,7). These analogues are mast cell secretagogues.…”

mentioning

confidence: 99%

“…and, when given intravenously to rats at a dose of 1.25 mgikg. can also cause cyanosis and respiratory depression leading to death (6). I t has been concluded from structureactivity studies that the structural combination of the basic D-Arg' residue (in close proximity to the Arg8) and the cluster of three aromatic D-amino acids at the A'-terminus, confers the toxic side reactions upon the LHRH antagonists (8).…”

mentioning

confidence: 99%

See 1 more Smart Citation

New antagonists of LHRH II. Inhibition and potentiation of LHRH by closely related analogues

Bajusz

Csernus

Janáky

et al. 1988

International Journal of Peptide and Protein Research

129

View full text Add to dashboard Cite

Modifications of the previously described LHRH antagonists, [Ac‐d‐Nal(2)1, d‐Phe(4Cl)2, d‐Trp3, d‐Cit6, d‐Ala10]LHRH and the corresponding d‐Hci6 analogue, have been made to alter the hydrophobicity of the N‐terminal acetyl‐tripeptide portion. Substitution of d‐Trp3 with the less hydrophobic d‐Pal(3) had only marginal effects on the antagonistic activities and receptor binding potencies of the d‐Cit/d‐Hci6 analogues, but it appeared to further improve the toxicity lowering effect of d‐Cit/d‐Hci6 substitution. Antagonists containing d‐Pal(3)3 and d‐Cit/d‐Hci6 residues, i.e. [Ac‐d‐Nal(2)1, d‐Phe(4Cl)2, d‐Pal(3)3d‐Cit6, d‐Ala10]LHRH (SB‐75) and [Ac‐d‐Nal(2)1, d‐Phe(4Cl)2, d‐Pal(3)3, d‐Hci6, d‐Ala10]LHRH (SB‐88), were completely free of the toxic effects, such as cyanosis and respiratory depression leading to death, which have been observed in rats with the d‐Trp3, d‐Arg6 antagonist and related antagonists. Replacement of the N‐acetyl group with the hydrophilic carbamoyl group caused a slight decrease in antagonistic activities, particularly in vitro. Introduction of urethane type acyl group such as methoxycarbonyl (Moc) or t‐butoxycarbonyl (Boc) led to analogues that showed LHRH‐potentiating effect. The increase in potency induced by these analogues, e.g. [Moc‐d‐Nal(2)1, d‐Phe(4Cl)2, d‐Trp3, d‐Cit6, d‐Ala10]LHRH and [Boc‐d‐Phe1, d‐Phe(4Cl)2, d‐Pal(3)3, d‐Cit6, d‐Ala10]LHRH, was 170‐260% and persisted for more than 2 h when studied in a superfused rat pituitary system.

show abstract

“…The utility of using glycosylated amino acid derivatives unprotected at the sugar moiety in the synthesis of glycopeptides has been already reported (3). Boc-(Glcr + P)Hyp-OH was prepared from Z-Hyp-OBzl and 2,3,4,6-tetra-O-benzyl-~glucopyranosyl(a + P)-trichloroacetimidate (10) in the presence of trimethylsilyl-trifluoromethane sulfonate. Catalytic hydrogenation followed by reaction with ditert.-butyl dicarbonate yielded Boc-(Glcr + P)Hyp-OH which was reacted with H-Arg(NOz)-OBzl(8) through the M.A.…”

mentioning

confidence: 99%

Synthesis and biological activity of [L‐hydroxyproline]³‐tuftsin analogue and its α‐ or β‐O‐D‐glucosylated derivatives

Biondi

Filira

Rocchi

et al. 1993

International Journal of Peptide and Protein Research

View full text Add to dashboard Cite

Syntheses are described of the Hyp3‐tuftsin analogue and of its derivatives α‐ or β‐O‐glycosylated at the side chain function of the hydroxyproline residue. The carbohydrate‐free tetrapeptide was prepared by reacting Z‐Thr‐Lys(Z)‐OH with H‐Hyp‐Arg(NO2)‐OBzl by the mixed anhydride procedure. In the synthesis of the α‐glycosylated analogue the O‐glycosyl amino acid was incorporated by reacting Boc‐(Glcα+β)Hyp‐OH with H‐Arg(NO2)‐OBzl through the same procedure. The α‐glucosylated dipeptide was isolated from the diastereomeric mixture, selectively deblocked, and acylated with Z‐Thr‐Lys(Z)‐OH by the mixed anhydride procedure. In the preparation of the β‐glucosylated analogue the BOP procedure was used for reacting Boc‐[Glc(Ac)4β]Hyp‐OH with H‐Arg(NO)2‐OBzl was well as for the final coupling to tetrapeptide. Removal of protecting groups from crude tetrapeptides was achieved by catalytic hydrogenation. Deacetylation of the sugar moiety of the β‐glucosylated tetrapeptide was achieved by treatment with sodium methoxide in methanol. The synthetic compounds were isolated by ion exchange chromatography, and characterized by elemental analysis, amino acid analysis, optical rotation and proton NMR. Their capacity to evoke the release of interleukin 1 from mouse peritoneal macrophages and to modulate immunogenic activity of antigen‐fed cells was evaluated, in comparison with tuftsin and rigin. All of the analogues were found to possess tuftsin‐like activity.

show abstract

Comments by Peter R. Schmidt

Cited by 4 publications

References 2 publications

Nonlinear Smooth Orthogonal Decomposition of Kinematic Features of Sawing Reconstructs Muscle Fatigue Evolution as Indicated by Electromyography

Nonlinear Smooth Orthogonal Decomposition of Kinematic Features of Sawing Reconstructs Muscle Fatigue Evolution as Indicated by Electromyography

New antagonists of LHRH II. Inhibition and potentiation of LHRH by closely related analogues

Synthesis and biological activity of [L‐hydroxyproline]³‐tuftsin analogue and its α‐ or β‐O‐D‐glucosylated derivatives

Contact Info

Product

Resources

About

Comments by Peter R. Schmidt

Cited by 4 publications

References 2 publications

Nonlinear Smooth Orthogonal Decomposition of Kinematic Features of Sawing Reconstructs Muscle Fatigue Evolution as Indicated by Electromyography

Nonlinear Smooth Orthogonal Decomposition of Kinematic Features of Sawing Reconstructs Muscle Fatigue Evolution as Indicated by Electromyography

New antagonists of LHRH II. Inhibition and potentiation of LHRH by closely related analogues

Synthesis and biological activity of [L‐hydroxyproline]3‐tuftsin analogue and its α‐ or β‐O‐D‐glucosylated derivatives

Contact Info

Product

Resources

About

Synthesis and biological activity of [L‐hydroxyproline]³‐tuftsin analogue and its α‐ or β‐O‐D‐glucosylated derivatives