Efficacy of three prototype termite cellulase inhibitors, cellobioimidazole (CBI), fluoromethylcellobiose (FMCB) and fluoromethylglucose (FMG) was investigated using biochemical and feeding assays. ...Optimal conditions for measuring endoglucanase, exoglucanase and β-glucosidase activities were first determined. The three inhibitors were then tested under optimal conditions against enzyme fractions that represented endogenous (foregut/salivary gland/midgut) and symbiotic (hindgut) cellulases.
In vitro, CBI and FMCB both inhibited exoglucanase and β-glucosidase activity (I
50s in nM and mM range, respectively). Feeding assays showed significant impacts on both survivorship and feeding stimulation by FMCB and CBI. Enzymatic measurements on feeding assay survivors showed impacts on all three cellulase activities by CBI and lesser impacts by FMG and FMCB. Validative bioassays with the sugars glucose, maltose and cellobiose showed no feeding stimulation or mortality as occurred in feeding inhibitor bioassays. These results indicate efficacy for two cellobiose-based inhibitors, FMCB and CBI, suggesting potential for these inhibitors as novel termite control agents.
We wished to determine if being treated for sleep apnea by a sleep specialist increased patient awareness or long-term continuous positive airway pressure (CPAP) compliance. We performed a ...retrospective telephone survey and laboratory chart review in patients with a diagnosis of sleep apnea evaluated either at a laboratory in which only sleep specialists can order polysomnography (University Specialty Hospital, noted as USH) or at a laboratory serving the medical community at large (Kernan Hospital, noted as K). Both laboratories are under the same medical director, use the same policies and procedures, equipment, and technician pool. One hundred three patients participated in the survey (approximately 37% of those contacted), 59 from USH and 44 from K. The groups were comparable in terms of demographics, presenting complaints, and apnea severity. In patients treated by sleep specialists, awareness of the disease process was greater and the evaluation was timelier than in patients treated by generalists. However, there was no difference between the groups' long-term self-reported CPAP acceptance or compliance. The most robust predictor of continued CPAP use was the patient's self-report of feeling better.
Esterases from insecticide resistant and susceptible
Blattella germanica (L.) were examined biochemically. Two strains were utilized: Johnson Wax (JWax; susceptible), and Munsyana (MA; chlorpyrifos ...LD
50 and LD
95 resistance ratio 5.2 and 10.0). On native polyacrylamide gel electrophoresis (PAGE), MA had four visible esterase electromorphs (El, E2, E3 and E4), whereas JWax had three (El, E2 and E4). Esterases E1 and E4 were more intense in the MA strain, and none of these esterase electromorphs were acetylcholinesterases. Insecticide inhibition of native esterases within polyacrylamide gels showed an interaction of all electromorphs with the carbamate insecticide propoxur and complete inhibition of all electromorphs by the carbamate bendiocarb and the organophosphate insecticides chlorpyrifos oxon, malaoxon and paraoxon. The pyrethroid insecticides permethrin and cypermethrin had no inhibitory effects. Sequential Q-Sepharose and hydroxyapatite column chromatography was used to fractionate esterases from each strain into two groups (I and II). Following hydroxyapatite fractionation of these esterase groups, inhibition kinetic constants (
k
a
and
k
3), and molecular weights were estimated. Results for
ka (the rate of enzyme inhibition) indicated a greater affinity for organophosphate insecticides by MA esterases. Results for
k3 (the rate of enzyme recovery) indicated lengthened times of MA esterase-inhibition by organophosphate insecticides. Therefore the role, if any, in organophosphate resistance played by MA esterases must be by sequestration. Molecular weight estimates were within the range (55–65 kDa) previously observed for esterases from both
B. germanica and
Culex quinquefasciatus
A new charging scheme for ATM based on QoS Miah, B.; Scharf, E. M.; Cuthbert, L. G. ...
International journal of communication systems,
02/2002, Letnik:
15, Številka:
1
Journal Article
Background Professional, long-term physical training is associated with cardiac morphologic and functional changes that depend on the type of exercise performed. So far, the specific effect of soccer ...training on cardiac morphology has not been investigated with cardiac magnetic resonance imaging (CMRI). We sought to use CMRI to study left ventricular (LV) and right ventricular (RV) morphologic and functional adaptations in professional soccer players. Methods Twenty-nine male professional soccer players (mean age 24.6 ± 3.9 years, range 18–31 years) in different playing positions and 29 nonathlete male controls (27.0 ± 3.7 years, 21–34 years) underwent CMRI. Electrocardiographic-gated steady-state free-precession cine CMRI was used to measure myocardial mass (MM), end-diastolic volume (EDV) and end-systolic volume, stroke volume (SV), ejection fraction, and cardiac index at rest. We calculated the ventricular remodeling index (RI) to describe the pattern of cardiac hypertrophy. Results Ventricular volume and mass indices were significantly ( P < .001) higher in athletes. LVEDV and RVEDV on MRI was above normal in 27/29 athletes. There was a strong positive correlation between EDV and myocardial mass ( P < .01). The LVRI and RVRI were similar (0.73 ± 0.1 g/mL; 0.22 ± 0.01 g/mL) to that of controls (0.71 ± 0.1 g/mL; 0.22 ± 0.01 g/mL). No significant differences were observed for LV ejection fraction and cardiac index. Neither the comparison of athletes in different playing positions nor the comparison of younger and older players revealed statistically significant differences. Conclusion Cardiac magnetic resonance imaging measurements enable studying the mechanisms of LV and RV adaptation in professional soccer players and reflect the ventricular response to combined endurance and strength based training.
Sleep apnea syndrome (SAS) often presents a difficult therapeutic problem to the clinician since many of the accepted modes
of therapy are associated with only partial success or with a number of ...long-term complications. We present three patients
with obstructive SAS in whom dramatic clinical improvement occurred following repair of a deviated nasal septum. The subjective
improvement was associated with a diminution in the number and duration of obstructive apnea episodes as observed during a
standard sleep study. Because of its simplicity and low rate of complication, we propose that repair of a deviated nasal septum
be further evaluated as a mode of therapy for this condition.
The problem of protein structure prediction is formulated here as that of evaluating how well an amino acid sequence fits a hypothetical structure. The simplest and most complicated approaches, ...secondary structure prediction and all-atom free energy calculations, can be viewed as sequence-structure fitness problems. Here, an approach of intermediate complexity is described, which involves; (1) description of a protein structure in terms of contact interface vectors, with both intra-protein and protein-solvent contacts counted, (2) derivation of sequence preferences for 2 up to 29 contact interface types, (3) generation of numerous hypothetical model structures by placing the input sequence into a large set of known three-dimensional structures in all possible alignments, (4) evaluation of these models by summing the sequence preferences over all structural positions and (5) choice of predicted three-dimensional structure as that with the best sequence-structure fitness. Evolutionary information is incorporated by using position-dependent core weights derived from multiple sequence alignments. A number of tests of the method are performed: (1) evaluation of cyclic shifts of a sequence in its native structure; (2) alignment of a sequence in its native structure, allowing gaps; (3) alignment search with a sequence or sequence fragment in a database of structures; and (4) alignment search with a structure in a database of sequences. The main results are: (1) a native sequence can very well find its native structure among a large number of alternatives, in correct alignment; (2) substructures, such as (beta alpha)n units, can be detected in spite of very low sequence similarity; (3) remote homologous can be detected, with some dependence on the set of parameters used; (4) contact interface parameters are clearly superior to classical secondary structure parameters; (5) a simple interface description in terms of just two states, protein-protein and protein-water contacts, performs surprisingly well; (6) the use of core weights considerably improves accuracy in detection of remote homologues; (7) based on a sequence database search with a myoglobin contact profile, the C-terminal domain of a viral origin of replication binding protein is predicted to have an all-helical fold. The sequence-structure fitness concept is sufficiently general to accommodate a large variety of protein structure prediction methods, including new models of intermediate complexity currently being developed.
