Preferential vastus medialis oblique activation achieved as a treatment for knee disorders

The purpose of this study was to compare the effect of an open-stance cycling protocol (OSCP) with the traditional cycling foot position (TCFP) for preferential vastus medialis oblique (VMO) muscle activation, measured by surface electromyography (SEMG), and preferential VMO activation as defined by achieving significantly increased VMO/VL (vastus lateralis muscle) ratio values. Forty subjects of both sexes participated, 18 symptomatic with patellofemoral pain and 22 control subjects; ages ranged from 18 to 60 years (mean = 28.7 +/- 8 years). The OSCP and TCFP were ridden in randomized order while SEMG recordings were taken of the VMO and VL muscles, collecting the mean of peak amplitudes to calculate VMO/VL ratio values. The SEMG readings were taken 4 times per testing session with randomized resistance and a consistent cycling cadence of 85 rpm. The OSCP displayed preferential VMO activation for all subject groups (F = 40.47, p = 0.0001), and this study revealed a protocol that effectively treats patellofemoral pain.     

Use of Caenorhabditis elegans G{alpha}q chimeras to detect G-protein-coupled receptor signals

G-protein-coupled receptors (GPCRs) activate heterotrimeric G-proteins (G(i)-, G(s)-, G(q)-, or G(12)-like) to generate specific intracellular responses, depending on the receptor/G-protein coupling. The aim was to enable a majority of GPCRs to generate a predetermined output by signaling through a single G-protein-supported pathway. The authors focused on calcium responses as the output, then engineered Galpha(q) to promote promiscuous receptor interactions. Starting with a human Galpha(q) containing 5 Galpha(z) residues in the C-terminal receptor recognition domain (hGalpha(q/z5)), they evaluated agonist-stimulated calcium responses for 33 diverse GPCRs (G(i)-, G(s)-, and G(q)-coupled) and found 20 of 33 responders. In parallel, they tested Caenorhabditis elegans Galpha(q) containing 5 or 9 C-terminal Galpha(z) residues (cGalpha(q/z5), cGalpha(q/z9)). Signal detection was enhanced with cGalpha(q/z5) and cGalpha(q/z9) (yielding 25/33 and 26/33 responders, respectively). In a separate study of Galpha(s)-coupled receptors, the authors compared hGalpha(q/s5) versus hGalpha(q/s9), cGalpha(q/s9), andcGalphaq/s21 and observed optimal function with cGalpha(q/s9). Cotransfection of an engineered Galpha(q) "cocktail" (cGalpha(q/z5) plus cGalpha(q/s9)) provided a powerful and efficient screening platform. When the chimeras included N-terminal myristoylation sites (to promote membrane localization), calcium responses were sustained or improved, depending on the receptor. This approach toward a "universal functional assay" is particularly useful for orphan GPCRs whose signaling pathways are unknown.     

Bacterial transglycosylase inhibitors

The spread of bacterial resistance to known antibiotics has inspired interest in previously under-exploited drug targets. The transglycosylation reaction remains a 'black box' in the generally well-studied process of bacterial peptidoglycan biosynthesis, which is a very attractive target for chemotherapeutic intervention. Here, we summarize recent progress in the study of bacterial transglycosylases and the compounds that inhibit them. The transglycosylation reaction is readily targeted by several different classes of natural products, implying that it should be possible to develop drugs that inhibit this process once efficient high-throughput screens and appropriate compound libraries have been developed.     

Trichloroacetaldehyde modified oligonucleotides

Some commercial batches of dichloroacetic acid (DCA) contain traces of chloral (trichloroacetaldehyde). Using such DCA to effect detritylation during solid-phase oligonucleotide synthesis results in the formation of a family of process impurities in which the atoms of chloral (Cl3CCHO) are incorporated between the 5'-oxygen and phosphorus atoms of an internucleotide linkage. The structure was elucidated by HPLC with UV and MS detection, digestion of the oligonucleotide, synthesis of model compounds, and 1H and 31P NMR spectroscopy. By understanding the chemistry behind its formation, we are now able to limit levels of this impurity in synthetic oligonucleotides by limiting chloral in DCA.     

Specific sensing between inositol epimers by a bis(boronate)

Bis(boronates) that utilize internal photoinduced electron transfer (PET) quenching mechanisms can specifically signal the binding of chiro-inositol without responding to its epimer, myo-inositol.     

Characterization of the copper(II) binding site in the pink copper binding protein CusF by electron paramagnetic resonance spectroscopy

Electron paramagnetic resonance (EPR) spectroscopy has been used to structurally characterize the copper-binding site in CusF protein from Escherichia coli. The EPR spectra indicate a single type II copper center with parameters typical for nitrogen and oxygen ligands (A~200 G, g~2.186, g~2.051). The pulsed EPR data show that one of the ligands to Cu²⁺ is an imidazole ring of a histidine residue. The remote amino nitrogen of this imidazole ring is readily observed by electron spin-echo envelope modulation spectroscopy, while the imino nitrogen that is directly coordinated to the Cu²⁺ ion is observed by pulsed electron–nuclear double resonance (ENDOR). In addition, the ENDOR spectra reveal the presence of one more nitrogen ligand that was assigned to be a deprotonated peptide nitrogen. Apart from the two nitrogen ligands, it has been established that there are two nearby hydroxyl protons, although whether these belong to a single equatorial water ligand or two equatorial hydroxide ligands is not known.

Identification of bis-quindolines as new antiinfective agents

Several N-substituted quindolines were made to further evaluate the role of N-alkylation on the activity of indoloquinolines as antifungal agents. While N-5 substitution is required for these activities, N-10 alkylation alone leads to inactive products but is tolerated in the presence of N-5 alkyl groups. It was also discovered that bis-quindolines appear to have a more expanded antimicrobial spectrum and lower cytotoxicity than their monomeric counterparts.     

Dimethylsulfoxide oxidizes glutathione in vitro and in human erythrocytes: kinetic analysis by 1H NMR

The interaction of dimethylsulfoxide (Me2SO) with glutathione was investigated under non-equilibrium conditions in solution using 1H NMR and in intact erythrocytes using 1H spin-echo NMR. In solution the reaction was observed to follow second-order kinetics (Rate = k1[glutathione][Me2SO]) at 300 K pH 7.4, k(sol) = 4.7 x 10(-5)mol(-1)L(1)s(-1). In intact erythrocytes the rate constant for the cellular environment, k(cell), was found to be slightly larger at 8.1 x 10(-5)mol(-1)L(1)s(-1). Furthermore, the reaction of Me2SO with erythrocyte glutathione showed a biphasic dependence on the Me2SO concentration, with little oxidation of glutathione occurring until the Me2SO concentration exceeded 0.5 molL(-1). The results suggest that at lower concentrations, Me2SO can be effectively removed, most probably by reaction with glutathione, which is regenerated by glutathione reductase, although preferential reaction with other cellular components (e.g., membrane or cellular thiols) cannot be ruled out. Thus the concentrations of Me2SO that are commonly used in cryopreservation of mammalian cells ( approximately 1.4 molL(-1)) can cause oxidation of intracellular glutathione.     

Id4 is required for the correct timing of neural differentiation

Complex intrinsic and extrinsic mechanisms determine neural cell fate during development of the nervous system. Using Id4 deficient mice, we show that Id4 is required for normal development of the central nervous system (CNS), timing neural differentiation in the developing forebrain. In the absence of Id4, the ventricular zone of the neocortex, future hippocampus as well as lateral and medial ganglionic eminences exhibited a 20-30% reduction in mitotic neural precursor cells (NPCs). Although the number of apoptotic cells was significantly increased, the neocortex of Id4(-/-) embryos was consistently thicker due to premature neuronal differentiation, which resulted in an increase in early-born neurons in the adult Id4(-/-) cortex. Late-born cortical neurons and astrocytes in the cortex, septum, hippocampus and caudate putamen of Id4(-/-) adult brains were decreased, however, likely due to the depletion of the NPC pool. Consequently, adult Id4(-/-) brains were smaller and exhibited enlarged ventricles. In vitro analysis of neurosphere cultures revealed that proliferation of Id4-deficient NPCs was impaired and that BMP2-mediated astrocyte differentiation was accelerated in the absence of Id4. Together, these in vivo and in vitro data suggest a crucial role for Id4 in regulating NPC proliferation and differentiation.