Effect of metalloproteinase inhibitor on corneal cytokine expression after alkali injury. (1/440)

PURPOSE: Interleukin (IL)-1alpha and IL-6 levels in the cornea are greatly elevated during the early stages after an alkali burn in mice. The authors investigated the effect of synthetic inhibitor of matrix metalloproteinase (SIMP) on the expression of inflammatory cytokines in alkali-burned murine corneas and evaluated the clinical appearance of the eyes. METHODS: After 0.5N NaOH-alkali burns to 400 corneas of ICR mice, 200 received 400 microg/ml of SIMP topically 4 times a day while 200 corneas were similarly treated with vehicle only. At days 4, 7 and 14 after injury, each cornea was assigned a clinical score for corneal opacity, corneal epithelial defect, hyphema and cataract. Extracts of injured corneas in each group were then assayed for cytokine production using ELISA systems for IL-1alpha, IL-1beta, IL-6 and tumor necrosis factor-alpha (TNF-alpha). RESULTS: The levels of IL-1alpha, IL-1beta and IL-6 were significantly lower in the SIMP-treated group than in the vehicle-treated group 7 days after the burn. However, levels of these cytokines were similar in the SIMP and non-SIMP groups at days 4 and 14. Levels of TNF-alpha did not differ between both groups at any postinjury time. In the SIMP-treated corneas, there was less opacification and hyphema formation and epithelial regeneration was faster. CONCLUSIONS: Topical application of SIMP in alkali-burned murine corneas reduced the expression of IL-1alpha, IL-1beta, and IL-6 and lessened the severity of the injury.  (+info)

The effects of ouabain and potassium on peritoneal fluid and solute transport characteristics. (2/440)

BACKGROUND: We reported anomalous transport characteristics of potassium during experimental peritoneal dialysis in rats and suggested that mechanisms of peritoneal potassium transport could be other than simple passive transport. Intracellular transport of potassium in cultured human mesothelial cells was reported to be regulated by three different pathways, such as channels blocked by ouabain, channels blocked by furosemide, and other. OBJECTIVE: To investigate the effect of ouabain on peritoneal potassium and water transport characteristics. METHODS: A single 4-hour peritoneal dwell was performed in 28 Sprague-Dawley rats. To minimize the diffusive transport of potassium, 4.5 mmol/L of KCl was added into conventional dialysis solution with 3.86% glucose [acidic peritoneal dialysis solution (APD)]. To evaluate the effect of the pH of dialysis solution on the transport of potassium and water, 4 mmol/L of NaOH was added into the potassium-containing study solutions [neutral peritoneal dialysis solution (NPD)]. To evaluate the effect of a potassium channel blocker on peritoneal potassium transport ATPase sensitive Na+-K+-transport inhibitor, ouabain (10(-5) mmol/L) was added to dialysis solutions immediately before the dwell study in eight rats with APD (APD-O) and six rats with NPD (NPD-O). Ouabain was not added in eight and six rats with APD and NPD (APD-C and NPD-C, respectively). They were used as control. Infusion volume was 30 mL. The intraperitoneal volume (V(D)) was estimated by using a volume marker dilution method with corrections for the elimination of volume marker, radioiodinated human serum albumin (RISA), from the peritoneal cavity (K(E)). The diffusive mass transport coefficient (K(BD)) and sieving coefficient (S) were estimated using the modified Babb-Randerson-Farrell model. RESULTS: V(D) was significantly higher (p < 0.05 from 90 min to 240 min) and K(E) (0.027+/-0.018 mL/min for APD-O, 0.026+/-0.017 mL/min for NPD-O, and 0.030+/-0.022 mL/min for NPD-C, vs 0.058+/-0.030 mL/min for APD-C, p < 0.05 for each) significantly lower during dialysis with APD-O, NPD-O, and NPD-C than with APD-C. The intraperitoneal glucose expressed as a percentage of the initial amount was significantly higher with APD-O, NPD-C, and NPD-O than with APD-C (p < 0.05 from 90 min to 240 min). K(BD) for sodium was higher during dialysis with ouabain than without ouabain, while K(BD) for urea, glucose, and potassium, and S for urea, glucose, sodium, and potassium did not differ between the four groups. CONCLUSIONS: The physiologic potassium concentration in neutral dialysis solutions and the use of ouabain decreased the intraperitoneal fluid absorption. The diffusive transport coefficient and sieving coefficient for potassium did not differ, while the diffusive transport coefficient for sodium increased during use of ouabain.  (+info)

The molecular basis of the solution properties of hyaluronan investigated by confocal fluorescence recovery after photobleaching. (3/440)

Hyaluronan (HA) is a highly hydrated polyanion, which is a network-forming and space-filling component in the extracellular matrix of animal tissues. Confocal fluorescence recovery after photobleaching (confocal-FRAP) was used to investigate intramolecular hydrogen bonding and electrostatic interactions in hyaluronan solutions. Self and tracer lateral diffusion coefficients within hyaluronan solutions were measured over a wide range of concentrations (c), with varying electrolyte and at neutral and alkaline pH. The free diffusion coefficient of fluoresceinamine-labeled HA of 500 kDa in PBS was 7.9 x 10(-8) cm(2) s(-1) and of 830 kDa HA was 5.6 x 10(-8) cm(2) s(-1). Reductions in self- and tracer-diffusion with c followed a stretched exponential model. Electrolyte-induced polyanion coil contraction and destiffening resulted in a 2.8-fold increase in self-diffusion between 0 and 100 mM NaCl. Disruption of hydrogen bonds by strong alkali (0.5 M NaOH) resulted in further larger increases in self- and tracer-diffusion coefficients, consistent with a more dynamic and permeable network. Concentrated hyaluronan solution properties were attributed to hydrodynamic and entanglement interactions between domains. There was no evidence of chain-chain associations. At physiological electrolyte concentration and pH, the greatest contribution to the intrinsic stiffness of hyaluronan appeared to be due to hydrogen bonds between adjacent saccharides.  (+info)

Recovery of mycobacteria from patients with cystic fibrosis. (4/440)

Despite decontamination, overgrowth by pseudomonads renders cultural isolation of mycobacteria from respiratory specimens of patients with cystic fibrosis (CF) difficult or impossible. We performed a prospective study by comparing levels of reduction of overgrowth and recovery of mycobacteria using either pretreatment with N-acetyl-L-cysteine (NALC)-NaOH alone or pretreatment with NALC-NaOH and then with oxalic acid. From 406 specimens of 148 CF patients, 11 specimens were positive for mycobacteria, 5 of which grew mycobacteria after decontamination by either procedure. Three specimens grew mycobacteria only after decontamination with NALC-NaOH, whereas three specimens grew mycobacteria only after treatment with NALC-NaOH followed by oxalic acid but were overgrown after decontamination with NALC-NaOH. Thus, inactivation of mycobacteria by the more aggressive oxalic acid treatment offsets its beneficial effect of reducing the proportion of cultures overgrown with microorganisms other than mycobacteria.  (+info)

Association of bacteriochlorophyll a with the CsmA protein in chlorosomes of the photosynthetic green filamentous bacterium Chloroflexus aurantiacus. (5/440)

The protein assumed to be associated with bacteriochlorophyll (BChl) a in chlorosomes from the photosynthetic green filamentous bacterium Chloroflexus aurantiacus was investigated by alkaline treatment, proteolytic digestion and a new treatment using 1-hexanol, sodium cholate and Triton X-100. Upon alkaline treatment, only the 5.7 kDa CsmA protein was removed from the chlorosomes among six proteins detected by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) analysis, concomitantly with the disappearance of BChl a absorption at 795 nm. Trypsin treatment removed two proteins with molecular masses of 11 and 18 kDa (CsmN and CmsM), whereas the spectral properties of BChl a and BChl c were not changed. By the new hexanol-detergent (HD) treatment, most BChl c and all of the detected proteins except CsmA were removed from the chlorosomes without changing the BChl a spectral properties. Subsequent proteinase K treatment of these HD-treated chlorosomes caused digestion of CsmA and a simultaneous decrease of the BChl a absorption band. Based on these results, we suggest that CsmA is associated with BChl a in the chlorosomes. This suggestion was supported by the measured stoichiometric ratio of BChl a to CsmA in isolated chlorosomes, which was estimated to be between 1.2 and 2.7 by amino acid analysis of the SDS-PAGE-resolved protein bands.  (+info)

The structure of the carbohydrate backbone of core-lipid A region ofthe lipopolysaccharides from Proteus mirabilis wild-type strain S1959 (serotype O3) and its Ra mutant R110/1959. (6/440)

The following structure of core-lipid A region of the lipopolysaccharide (LPS) from Proteus mirabilis strain 1959 (serotype O3) and its rough mutant R110/1959 (Proteus type II core) was determined using NMR and chemical analysis of the core oligosaccharide, obtained by mild acid hydrolysis of LPS, and of the products of alkaline deacylation of the LPS: Incomplete substitutions are indicated by italics. All sugars are in pyranose form, alpha-Hep is the residue Lglycero-alpha-Dmanno-Hep, alpha-DD-Hep is the residue Dglycero-alpha-Dmanno-Hep. The differences with the previously reported structures are discussed.  (+info)

A comparison of sodium hydroxide and sodium sulfide digestion of mouse hair in the recovery of radioactivity following systemic administration of [3H]-nicotine and [3H]-flunitrazepam. (7/440)

Pigmented (C57BI) and nonpigmented (balb/c) mice, 25 days of age, were treated intraperitoneally with [3H]-nicotine (4 mg/kg, 555 dpm/ng) or [3H]-flunitrazepam (1 mg/kg, 2200 dpm/ng) daily for three days. After 21 days, shaved back hair was digested at 37 degrees C for 24 h with either 1 M sodium hydroxide or 1 M sodium sulfide. With both drugs, sodium sulfide extraction removed the same amount of radioactivity as sodium hydroxide from nonpigmented hair. However, sodium sulfide removed significantly more radioactivity from pigmented hair than did sodium hydroxide. In pigmented hair, sodium sulfide solubilized 35% and 74% of the flunitrazepam- and nicotine-associated radioactivity, respectively. Of this, 12% and 43%, respectively, could be partitioned into ethyl acetate. Microscopic examination of residual pellets after digestion demonstrated a more thorough dissolution of the hair shaft with sodium sulfide with only melanosomes remaining. The results demonstrate the significant interaction of flunitrazepam and nicotine with melanins and the utility of sodium sulfide in increasing drug recovery.  (+info)

Compound A does not accumulate during closed circuit sevoflurane anaesthesia with the Physioflex. (8/440)

We have investigated inspiratory and end-tidal gas composition during sevoflurane anaesthesia in a closed circle system with continuous gas flow (70 litre min-1, Physioflex) to determine possible accumulation of sevoflurane degradation products. During five abdominal operations in adults lasting more than 2 h, anaesthesia was maintained with an end-tidal concentration of 2% sevoflurane in 40% oxygen-air. The circle included an absorbing canister filled with 1 litre of fresh soda lime. Samples were obtained at the end of an expiration from the tracheal tube and from the inspiratory limb before, and at selected times after, addition of sevoflurane. The temperature of soda lime was 24.7 +/- 0.7 degrees C at the beginning and reached a maximum of 31.2 +/- 1.0 degrees C after 20-30 min, followed by a plateau. Inspiratory compound A (CH2F-O-C(= CF2)(CF3)) 3-8 ppm was detected after 10 min, but did not accumulate in the circle over 2 h without flushing. Expired concentrations were consistently lower with 1.5-3 ppm signalling absorption by patients. Calculated total amounts absorbed over 2 h varied between 2.0 and 7.2 ppm h. Other degradation products such as compound B or methanol were not detected. In summary, we did not detect sevoflurane metabolites with soda lime in significant amounts during closed circle anaesthesia with the Physioflex. The observed concentrations of compound A were below the threshold of nephrotoxicity in rats by a factor of more than 20.  (+info)

• 1
• 2
• 3
• 4
• 5
• 6
• 7
• 8
• 9
• 10