Changes in reactivity of the middle cerebral artery caused by cerebral circulation disturbances of ischemic and hemorrhagic types in rats

Reactivity of the middle cerebral artery (MCA) to serotonin was attenuated in vitro in vessels taken from rats following an audiogenic stress. The MCA reactivity to endothelin remained unchanged. Chronic cerebral ischemia diminished the 5-HT-induced contraction and the contractile responses to endothelin were enhanced. Preliminary hypoxic adaptation decreased the artery sensitivity to endothelin in ischemic animals. The findings suggest that a progressing ischemia may involve changes in reactivity of cerebral vessels whereupon hypoxic adaptation may prove to be protecting the brain from ischemia development.     

Technique of lymphatic mapping and sentinel node biopsy for melanoma

AIM: To evaluate the effect of PD Plus on weekly Kt/Vurea and creatinine clearance (Kcr) among patients undergoing CAPD/CCPD (continuous ambulatory peritoneal dialysis/continuous cyclic peritoneal dialysis). METHODS: The kinetic studies of 92 CAPD and 18 CCPD patients who transferred to PD Plus were analyzed. All patients underwent CAPD/CCPD and PD Plus for a minimum of 3 months. Standard collection methods were used and kinetic indices calculated with the Pack PD Kinetic Modeling program. 57 patients had transport data and were modeled for a target weekly Kt/Vurea >/=2.1 using PD Plus with /=2.1 and 47% a Kcr >/=60 liters/1.73 m2 with PD Plus, but only 20% did so with CAPD/CCPD. A close correlation between the supervised patients and modeled therapy was observed. CONCLUSIONS: Adequate dialysis is possible by using higher fill volumes, the supine position, and optimal dwell times (PD Plus) in most patients. The discrepancy between modeled and achieved dose is likely due to poor compliance with therapy, inadequate training, or poor specimen collection.     

Effect of tyrosine kinase and tyrosine phosphatase inhibitors on ATP- and thapsigargin-induced CA2+ entry in rat peritoneal macrophages

The production of eicosapentaenoic acid [20:5omega3; EPA] from Shewanella gelidimarina (ACAM 456T) was investigated with respect to growth temperature and growth on sole carbon sources. The percentage and quantitative yield of EPA remained relatively constant at all growth temperatures within or below the optimal growth temperature region. At higher growth temperatures, these values decreased greatly. Growth on differing sole carbon sources also influenced the percentage and amount of EPA produced, with the fatty acid composition influenced by provision of potential acyl chain primers as sole carbon sources. The highest amounts of EPA occurred from growth on propionic acid and L-leucine respectively, while the highest percentage of EPA occurred from growth on L-proline. Monounsaturated fatty acid components and EPA were concentrated in phosphatidylglycerol (PG), while the proportion of branched-chain fatty acids was elevated in phosphatidylethanolamine (PE); the two major phospholipid classes. Specific associations of EPA with other acyl chains were identified within cellular phospholipid classes. The association of EPA with 17:1 and 18:0 acyl chains in phospholipid species was specific to PG, whereas the association of EPA with i13:0/13:0 and 14:0/i14:0 was specific to PE. Such acyl chain 'tailoring' is indicative of the important role of EPA in bacterial membrane adaptive responses. EPA was also a large component (22%) of a non-esterified fatty acid (NEFA) fraction within the total lipid extract of the bacterium. This may point toward a particular role of NEFA in polyunsaturated fatty acid (PUFA) metabolism. The formation of EPA was investigated by labelling with L-[U-14C]serine and sodium [1-14C]acetate. The accumulation of radiolabel within unsaturated intermediates (di-, tri- and tetraunsaturated fractions) was low, indicating a rapid formation and derivatisation of these components. Similar results were found for the unsaturated fatty acid fractions of both PE and PG using sodium [1-14C]acetate radiolabel. The regulation of triunsaturated fatty acid components may be a potential control site in PUFA biosynthesis.     

Time-level relationship for lipid peroxidation and the protective effect of alpha-tocopherol in experimental mild and severe brain injury

OBJECTIVE: Oxygen free radical-mediated lipid peroxidation has been proposed to be one of the major mechanisms of secondary damage in traumatic brain injury. The first purpose of this study was to establish the time-level relationship for lipid peroxidation in injured brain tissue. The second purpose was to examine the protective effect of alpha-tocopherol against lipid peroxidation. METHODS: For this study, 65 guinea pigs in five groups were studied. Five of the animals were identified as a control group, and the remaining 60 animals were divided equally into four groups (Groups A, B, C, and D). Mild injury (200 g x cm) (Groups A and C) and severe injury (1000 g x cm) (Groups B and D) were produced by the method of Feeney et al. Alpha-tocopherol (100 mg/kg) was administered intraperitoneally before brain injury in Groups C and D. Five animals from each group were killed immediately after trauma, five after 1 hour, and the remaining five animals after 36 hours. Lipid peroxidation in traumatized brain tissues was assessed using the thiobarbituric acid method. RESULTS: In all groups with traumatic brain injuries, levels of malondialdehyde, a lipid peroxidation product, were higher than in the control group. The amount of lipid peroxidation was increased by the severity of the trauma. Alpha-tocopherol significantly suppressed the rise in lipid peroxide levels in traumatized brain tissues. CONCLUSION: This study demonstrates that lipid peroxidation is increased by the severity of trauma and that alpha-tocopherol has a protective effect against oxygen free radical-mediated lipid peroxidation in mild and severe brain injury.     

Determination of radial growth rate of colonies of Sclerotium rolfsii F-6656 for the evaluation of culture medium, optimum incubation temperature, osmo- and halotolerance

The measurement of the colony radial growth rate (Kr) on solid medium of colonies of Sclerotium rolfsii Proimi F-6656 for the evaluation of scleroglucan production medium and other different media, incubation temperature and tolerance to diverse concentrations of sucrose and NaCl were studied. The optimum growth temperature observed was 30 degrees C. The Kr value reached on the Production Medium used (0.66 mm.h-1) showed no differences compared with those of the other media tested, indicating that all the requirements for growth were provided. Poor growth was only observed on Soil Extract Agar. The fungus tolerated concentrations of sucrose from 0.15 to 1.17 M, on both Czapek and production medium. Growth was limited by the highest concentrations of sucrose tested (0.88 and 1.17 M), as indicated by a slower increase in colony size. Addition of 0.86 M NaCl to the production medium and YM agar did not inhibit growth completely, but decreased the radial growth rate considerably (80 and 70% respectively).     

Combined Fish Oil and High Oleic Sunflower Oil Supplements Neutralize their Individual Effects on the Lipid Profile of Healthy Men

Both n-3 and n-9 fatty acids share a common metabolic pathway and can potentially and individually improve cardiovascular disease risk factors. Dietary n-6 is known to weaken the efficacy of n-3 fatty acids due to competition for the same enzymes. Still unclear is whether a similar competition exists between n-3 and n-9 fatty acids. Thus, a 12-week intervention study was conducted to investigate the effect of different combinations of fish oil and high-oleic sunflower oil (OSO) on healthy subjects. Included were five groups (98 subjects): three groups received a fixed amount of n-9 (8 g/day) with varying amounts of n-3 (1, 2 or 4 g/day), one group was given n-3 fatty acids only (2 g/day) and another was given n-9 only (8 g/day). We found that fish oil supplement (2 g/day) was able to decrease TAG by about 13 %, this effect was diminished with the co-ingestion of n-9 (OSO). Intake of OSO (8 g/day) reduced both total and LDL cholesterol by about 10 %, this effect was reduced by the addition of fish oil. Both fish oil and OSO failed to have any significant effect on both glycemic and blood pressure parameters. In conclusion; the impact of oleic acid (n-9) on total and LDL cholesterol was altered by the addition fish oil (n-3). These effects may have been the result of enzymatic competition between the two types of fatty acids.     

Reliability of intraocular pressure measurements after myopic excimer photorefractive keratectomy

OBJECTIVE: To determine the reliability of intraocular pressure (IOP) measurements by Goldmann applanation tonometry and pneumotonometry in eyes treated with excimer myopic photorefractive keratectomy (PRK). DESIGN: A prospective case series. PARTICIPANTS: Forty consecutive eyes treated with PRK were evaluated. INTERVENTION AND MAIN OUTCOME MEASURES: Central and peripheral corneal Goldmann tonometry and pneumotonometry measurements were done before surgery, at 1 week, and at 1 and 3 months after surgery. RESULTS: The IOP by Goldmann tonometry from the central cornea was significantly lower than the peripheral IOP; however, there was no difference between IOP measured from central and peripheral corneas by pneumotonometry, which, in turn, correlated with peripheral Goldmann measurements. There was a trend, but not a statistically significant correlation, between the spherical equivalent of the treatment and the amount of decrease in central Goldmann IOP. CONCLUSIONS: Pneumotonometry measures the IOP reliably after PRK from all parts of the cornea, whereas central Goldmann tonometry underestimates the IOP by 2.40+/-1.23 mmHg.