Changes in gene expression in the intact human heart. Downregulation of alpha-myosin heavy chain in hypertrophied, failing ventricular myocardium

Using quantitative RT-PCR in RNA from right ventricular (RV) endomyocardial biopsies from intact nonfailing hearts, and subjects with moderate RV failure from primary pulmonary hypertension (PPH) or idiopathic dilated cardiomyopathy (IDC), we measured expression of genes involved in regulation of contractility or hypertrophy. Gene expression was also assessed in LV (left ventricular) and RV free wall and RV endomyocardium of hearts from end-stage IDC subjects undergoing heart transplantation or from nonfailing donors. In intact failing hearts, downregulation of beta1-receptor mRNA and protein, upregulation of atrial natriuretic peptide mRNA expression, and increased myocyte diameter indicated similar degrees of failure and hypertrophy in the IDC and PPH phenotypes. The only molecular phenotypic difference between PPH and IDC RVs was upregulation of beta2-receptor gene expression in PPH but not IDC. The major new findings were that (a) both nonfailing intact and explanted human ventricular myocardium expressed substantial amounts of alpha-myosin heavy chain mRNA (alpha-MHC, 23-34% of total), and (b) in heart failure alpha-MHC was downregulated (by 67-84%) and beta-MHC gene expression was upregulated. We conclude that at the mRNA level nonfailing human heart expresses substantial alpha-MHC. In myocardial failure this alteration in gene expression of MHC isoforms, if translated into protein expression, would decrease myosin ATPase enzyme velocity and slow speed of contraction.     

T cell proliferation in response to interleukins 2 and 7 requires p38MAP kinase activation

Interleukin-2 (IL-2) is a potent T cell mitogen. However, the signaling pathways by which IL-2 mediates its mitogenic effect are not fully understood. One of the members of the mitogen-activated protein kinase (MAPK) family, p42/44MAPK (ERK2/1), is known to be activated by IL-2. We have now investigated the response to IL-2 of two other members of the MAP kinase family, p54MAP kinase (stress-activated protein kinase (SAPK)/Jun-N-terminal kinase (JNK)) and p38MAP kinase (p38/Mpk2/CSBP/RK), which respond primarily to stressful and inflammatory stimuli (e.g. tumor necrosis factor-alpha, IL-1, and lipopolysaccharide). Here we show that IL-2, and another T cell growth factor, IL-7, activate both SAPK/JNK and p38MAP kinase. Furthermore, inhibition of p38MAP kinase activity with a specific pyrinidyl imidazole inhibitor SB203580 that prevents activation of its downstream effector, MAPK-activating protein kinase-2, correlated with suppression of IL-2- and IL-7-driven T cell proliferation. These data indicate that in T cells p38MAP kinase has a role in transducing the mitogenic signal.     

Light and electron microscopic distribution of the AMPA receptor subunit, GluR2, in the spinal cord of control and G86R mutant superoxide dismutase transgenic mice

The NMR structure of the 98 residue beta-elicitin, cryptogein, which induces a defence response in tobacco, was determined using 15N and 13C/15N labelled protein samples. In aqueous solution conditions in the millimolar range, the protein forms a discrete homodimer where the N-terminal helices of each monomer form an interface. The structure was calculated with 1047 intrasubunit and 40 intersubunit NOE derived distance constraints and 236 dihedral angle constraints for each subunit using the molecular dynamics program DYANA. The twenty best conformers were energy-minimized in OPAL to give a root-mean-square deviation to the mean structure of 0.82 A for the backbone atoms and 1.03 A for all heavy atoms. The monomeric structure is nearly identical to the recently derived X-ray crystal structure (backbone rmsd 0.86 A for residues 2 to 97) and shows five helices, a two stranded antiparallel beta-sheet and an omega-loop. Using 1H,15N HSQC spectroscopy the pKa of the N- and C-termini, Tyr12, Asp21, Asp30, Asp72, and Tyr85 were determined and support the proposal of several stabilizing ionic interactions including a salt bridge between Asp21 and Lys62. The hydroxyl hydrogens of Tyr33 and Ser78 are clearly observed indicating that these residues are buried and hydrogen bonded. Two other tyrosines, Tyr47 and Tyr87, show pKa's > 12, however, there is no indication that their hydroxyls are hydrogen bonded. Calculations of theoretical pKa's show general agreement with the experimentally determined values and are similar for both the crystal and solution structures.     

Effect of selected Hofmeister anions on functional properties of protein isolate prepared from lablab seeds (Lablab purpureus)

Effects of selected Hofmeister anions, namely Na₂SO₄, NaCl, NaBr, NaI, NaClO₄ and NaSCN, on the functional properties of a protein isolate prepared from lablab seeds (Lablab purpureus) were investigated. The results of water absorption capacity indicated that highest water absorption was recorded in solutions of Na₂SO₄, and the lowest in NaSCN solutions. Reduction in water absorption capacity followed the Hofmeister series in the order Na₂SO₄ > NaCl > NaBr, NaI > NaClO₄ > NaSCN. Protein solutions prepared in chaotropic (NaI, NaClO₄, NaSCN) salts had better foam capacity, foam stability, emulsifying activity and emulsion stability than solutions prepared with kosmotropic salts (Na₂SO₄, NaCl, NaBr). The results also indicate that increase in foam capacity and stability followed the Hofmeister series in the order Na₂SO₄ < NaCl < NaBr, NaI < NaClO₄ < NaSCN. When least gelation concentration (LGC) was used as the index of gelation capacity, at various salts concentrations, the lowest LGC were observed in NaSCN and the highest LGC in protein solutions prepared with Na₂SO₄. Copyright © 2005 Society of Chemical Industry     

Hydrazone-Tethered 5-(Pyridin-4-yl)-4H-1,2,4-triazole-3-thiol Hybrids: Synthesis,Characterisation, in silico ADME Studies,and in vitro Antimycobacterial Evaluation and Cytotoxicity

Compounds containing arylpyrrole-, 1,2,4-triazole- and hydrazone structural frameworks have been widely studied and demonstrated to exhibit a wide range of pharmacological properties. Herein, an exploratory series of new 1,2,4-triazole derivatives designed by amalgamation of arylpyrrole and 1,2,4-triazole structural units via a hydrazone linkage is reported. The synthesised compounds were tested in vitro for their potential activity against Mycobacterium tuberculosis (MTB) H₃₇Rv strain. The most promising compound 13 – the derivative without the benzene ring appended to the pyrrole unit displayed acceptable activity (MIC₉₀=3.99 μM) against MTB H₃₇Rv, while other compounds from the series exhibited modest to weak antimycobacterial activity with MIC₉₀ values in the range between 7.0 and >125 μM. Furthermore, in silico results, predicated using the SwissADME web tool, show that the prepared compounds display desirable ADME profile with parameters within acceptable range.     

The use of a non‐equilibrated solid phase microextraction method to quantitatively determine the off‐notes in mint and other essential oils

The undesirable top notes or off‐notes found in mint, clary sage, and cedarwood oils could be quantitatively determined using a non‐equilibrated solid phase microextraction/gas chromatography/selected ion monitoring/mass spectrometry (SPME/GC/SIM‐MS) technique. Using the low threshold components, dimethyl sulfide, 2‐methylpropanal, 2‐methylbutanal, and 3‐methylbutanal, which are associated with the off‐notes of these oils, their levels could be reproducibly quantitatively determined. The highest level of off‐notes was found in a sample of Scotch spearmint oil where the levels of the four constituents were, dimethyl sulfide (238 µg g^?1), 2‐methylpropanal (286 µg g^?1), 2‐methylbutanal (1048 µg g^?1) and 3‐methylbutanal (1489 µg g^?1). These quantitative results in combination with sensory evaluations could provide for a powerful overall assessment of essential oil quality. Copyright © 2004 Society of Chemical Industry     

Benefits of a clinical pharmacokinetic service in optimising phenytoin use in the western Cape

OBJECTIVES: To study the benefits of a clinical pharmacokinetic service in optimising phenytoin use in the Western Cape. DESIGN: Assessment of the response to treatment was based on the number of seizures during the 3 months before entering the study (first baseline period), 3 months after entering the study (second baseline period) and 3 months before the termination of the study (test period). Patients kept a seizure diary throughout the study. The Michaelis-Menten model was used to calculate doses and predict steady-state serum concentrations. SETTING: Nine epilepsy clinics. SUBJECTS: One hundred and ninety-five (113 black and 82 coloured) compliant people with epilepsy receiving generic phenytoin monotherapy. OUTCOME MEASURES: Reduction in seizure frequency and adverse effects. RESULTS: A reduction in seizure frequency (64.8% compared with pre-optimisation) was experienced by 64.9% of patients. Mean seizure frequency was reduced from 3.39 to 1.18 per month. Reductions in seizure frequency of 100% and more than 50% were reported by 39.2% and 58.7% of patients, respectively. Adverse effects of phenytoin were reduced from 20.5% at the first visit to 3.2% at the last visit. CONCLUSION: The clinical pharmacokinetic dosing service for phenytoin applied in this study contributed significantly to the success of epilepsy management.     

Synthesis, structure, and antiproliferative activity of selenophenfurin, an inosine 5'-monophosphate dehydrogenase inhibitor analogue of selenazofurin

The synthesis and biological activity of selenophenfurin (5-beta-D-ribofuranosylselenophene-3-carboxamide, 1), the selenophene analogue of selenazofurin, are described. Glycosylation of ethyl selenophene-3-carboxylate (6) under stannic chloride-catalyzed conditions gave 2- and 5-glycosylated regioisomers, as a mixture of alpha- and beta-anomers, and the beta-2,5-diglycosylated derivative. Deprotected ethyl 5-beta-D-ribofuranosylselenophene-3-carboxylate (12 beta) was converted into selenophenfurin by ammonolysis. The structure of 12 beta was determined by 1H- and 13C-NMR, crystallographic, and computational studies. Selenophenfurin proved to be antiproliferative against a number of leukemia, lymphoma, and solid tumor cell lines at concentrations similar to those of selenazofurin but was more potent than the thiophene and thiazole analogues thiophenfurin and tiazofurin. Incubation of K562 cells with selenophenfurin resulted in inhibition of IMP dehydrogenase (IMPDH) (76%) and an increase in IMP pools (14.5-fold) with a concurrent decrease in GTP levels (58%). The results obtained confirm the hypothesis that the presence of heteroatoms such as S or Se in the heterocycle in position 2 with respect to the glycosidic bond is essential for both cytotoxicity and IMP dehydrogenase inhibitory activity in this type of C-nucleosides.