Effects of the nasal valve on acoustic rhinometry measurements: a model study.

The influence of nasal valve on acoustic rhinometry (AR) measurements was evaluated by using simple nasal cavity models. Each model consisted of a cylindrical pipe with an insert simulating the nasal valve. The AR-determined cross-sectional areas beyond the insert were consistently underestimated, and the corresponding area-distance curves showed pronounced oscillations. The area underestimation was more pronounced in models with inserts of small passage area. The experimental results are discussed in terms of theoretically calculated "sound-power reflection coefficients" for the pipe models. The reason for area underestimation is reflection of most of the incident sound power from the barrier at the front junction between the pipe and the insert. It was also demonstrated that the oscillations are due to low-frequency acoustic resonances in the portion of the pipe beyond the insert. The results suggest that AR does not provide reliable information about the cross-sectional areas of the nasal cavity posterior to a significant constriction, such as pathologies narrowing the nasal valve area. When the passage area of the nasal valve is decreased, the role of AR as a diagnostic tool for the entire nasal cavity becomes limited.     

Effects of paranasal sinus ostia and volume on acoustic rhinometry measurements: a model study.

We used pipe models to investigate the effects of paranasal sinus ostium size and paranasal sinus volume on the area-distance curves derived by acoustic rhinometry (AR). Each model had a Helmholtz resonator or a short neck as a side branch that simulated the paranasal sinus and sinus ostium. The AR-derived cross-sectional areas posterior to the ostium were significantly overestimated. Sinus volume affected the AR measurements only when the sinus was connected via a relatively large ostium. The experimental area-distance curve posterior to the side branch showed pronounced oscillations in association with low-frequency acoustic resonances in this distal part of the pipe. The experimental results are discussed in terms of theoretically calculated "sound-power reflection coefficients" for the pipe models used. The results indicate that the effects of paranasal sinuses and low-frequency acoustic resonances in the posterior part of the nasal cavity are not accounted for in the current AR algorithms. AR does not provide reliable information about sinus ostium size, sinus volume, or cross-sectional area in the distal parts of nasal cavity.     

History and integrity of thoroughbred dam lines revealed in equine mtDNA variation

Mitochondrial DNA (mtDNA) D-loop sequences (381 bp) from 100 thoroughbreds in 19 of the most common matrilineal female families were used to reconstruct a founder female population for the thoroughbred ( approximately 1650-1750 AD). Seventeen haplotypes were found to have contributed to the 19 female lineages. In order to place the reconstructed founder population in wider historical context, we examined, using both single strand conformation polymorphism and direct sequence analysis, variation in a 343 bp mtDNA fragment in that population and 13 other horse populations of disparate provenance. Interpopulation diversity analyses revealed no significant difference in variation between the thoroughbred founder population and the 13 other diverse horse populations and suggested a non-random partitioning of diversity among geographically diverse horse populations. Within thoroughbreds, almost half of the female families, which are each considered from pedigrees to have matrilines converging to one of >30 historically recognized female ancestors, contained sequences which were inconsistent with common descent. Examination of the anomalies in the context of pedigree records suggests the majority might be best explained as confusion of mares at the foundation stages, although some could have some bearing on more recent (19th century - 1980) lineages. We have used this combination of molecular and historical information to identify some of the founder dams and to make new interpretations about the early history of the thoroughbred.     

Effects of intraperitoneally administered lipoic acid,vitamin E,and linalool on the level of total lipid and fatty acids in guinea pig brain with oxidative stress induced by H2O2

The aim of our study was to investigate the protective effects of intraperitoneally-administrated vitamin E, dlalpha lipoic acid, and linalool on the level of total lipid and fatty acid in guinea pig brains with oxidative stress that was induced by H2O2. The total brain lipid content in the H2O2 group decreased when compared to the H2O2 + vitamin E (p<0.05), H2O2+ linalool (p<0.05), ALA (p<0.05), control (p<0.01), linalool (p<0.01), and vitamin E (p<0.01) groups. While the proportion of total saturated fatty acid ( infinity SFA) in the H2O2 group significantly increased (p<0.005) when compared to the vitamin E group, it only slightly increased (p<0.01) when compared to the control and H2O2 + vitamin E groups. The ratio of the total unsaturated fatty acid (infinity USFA) in the H2O2 groups was lower (p<0.05) than the control, vitamin E, and H2O2+ vitamin E groups. The level of the total polyunsaturated fatty acid (infinity USFA) in the H2O2 group decreased in when compared to the control, vitamin E, and H2O2+vitamin E groups. While the proportion of the total w3 (omega 3), w6 (omega 6), and PUFA were found to be lowest in the H2O2 group, they were slightly increased (p<0.05) in the lipoic acid group when compared to the control and H2O2 + lipoic acid groups. However, the level of infinity SFA in the H2O2 group was highest; the level of infinity USFA in same group was lowest. As the proportion of infinity USFA and infinity PUFA were found to be highest in the linalool group, they were decreased in the H2O2 group when compared to the control group. Our results show that linalool has antioxidant properties, much the same as vitamin E and lipoic acid, to prevent lipid peroxidation. Additionally, vitamin E, lipoic acid, and linalool could lead to therapeutic approaches for limiting damage from oxidation reaction in unsaturated fatty acids, as well as for complementing existing therapy for the treatment of complications of oxidative damage.     

Presence of factors that activate platelet aggregation in mitral stenotic patients' plasma

Background

In high-risk coronary artery bypass patients; off-pump versus on-pump surgical strategies still remain a matter of debate, regarding which method results in a lower incidence of perioperative mortality and morbidity. We describe our experience in the treatment of high-risk coronary artery patients and compare patients assigned to on-pump and off-pump surgery.

Methods

From March 2002 to July 2004, 86 patients with EuroSCOREs > 5 underwent myocardial revascularization with or without cardiopulmonary bypass. Patients were assigned to off-pump surgery (40) or on-pump surgery (46) based on coronary anatomy coupled with the likelihood of achieving complete revascularization.

Results

Those patients undergoing off-pump surgery had significantly poorer left ventricular function than those undergoing on-pump surgery (28.6 ± 5.8% vs. 40.5 ± 7.4%, respectively, p < 0.05) and also had higher Euroscore values (7.26 ± 1.4 vs. 12.1 ± 1.8, respectively, p < 0.05). Differences between the two groups were nonsignificant with regard to number of grafts per patient, mean duration of surgery, anesthesia and operating room time, length of stay intensive care unit (ICU) and rate of postoperative atrial fibrillation

Conclusion

Utilization of off-pump coronary artery bypass graft (CABG) does not confer significant clinical advantages in all high-risk patients. This review suggest that off-pump coronary revascularization may represent an alternative approach for treatment of patients with Euroscore ≥ 10 and left ventricular function ≤ 30%.     

Development and brain delivery of chitosan-PEG nanoparticles functionalized with the monoclonal antibody OX26

The inhibition of the caspase-3 enzyme is reported to increase neuronal cell survival following cerebral ischemia. The peptide Z-DEVD-FMK is a specific caspase inhibitor, which significantly reduces vulnerability to the neuronal cell death. However, this molecule is unable to cross the blood-brain barrier (BBB) and to diffuse into the brain tissue. Thus, the development of an effective delivery system is needed to provide sufficient drug concentration into the brain to prevent cell death. Using the avidin (SA)-biotin (BIO) technology, we describe here the design of chitosan (CS) nanospheres conjugated with poly(ethylene glycol) (PEG) bearing the OX26 monoclonal antibody whose affinity for the transferrin receptor (TfR) may trigger receptor-mediated transport across the BBB. These functionalized CS-PEG-BIO-SA/OX26 nanoparticles (NPs) were characterized for their particle size, zeta potential, drug loading capacity, and release properties. Fluorescently labeled CS-PEG-BIO-SA/OX26 nanoparticles were administered systemically to mice in order to evaluate their efficacy for brain translocation. The results showed that an important amount of nanoparticles were located in the brain, outside of the intravascular compartment. These findings, which were also confirmed by electron microscopic examination of the brain tissue indicate that this novel targeted nanoparticulate drug delivery system was able to translocate into the brain tissue after iv administration. Consequently, these novel nanoparticles are promising carriers for the transport of the anticaspase peptide Z-DEVD-FMK into the brain.