Effects of orthognathic surgery on pharyngeal airway and respiratory function during sleep in patients with mandibular prognathism.

The aim of this study was to determine changes in overnight respiratory function and craniofacial and pharyngeal airway morphology following orthognathic surgery. The subjects were 40 patients in whom mandibular prognathism was corrected by orthognathic surgery: a one-jaw operation in 22 patients and a two-jaw operation in 18 patients. Morphological changes were studied using cone beam computed tomography immediately before surgery and at more than 6 months after surgery, and the apnoea-hypopnoea index (AHI) was measured with a portable polysomnography system. Pharyngeal airway volume was decreased significantly after surgery, especially in the one-jaw operation group. AHI was not changed significantly after surgery in either group, although AHI in one patient in the one-jaw operation group was increased to 19 events/h. There was no significant change in pharyngeal airway morphology in that patient, but he was obesity class 1 and was 54 years old. In conclusion, some patients who are obese, have a large amount of mandibular setback, and/or are of relatively advanced age may develop sleep-disordered breathing after mandibular setback; a two-jaw operation should therefore be considered in skeletal class III patients who have such risks because it decreases the amount of pharyngeal airway space reduction caused by mandibular setback surgery.

Relationship between real-time monitoring of the graft motility and mucosal histology in swine intestinal transplantation.

We studied the correlation between the motility and the mucosal histology of the small bowel seeking to detect rejection in an early stage by real-time monitoring using a swine model. Intestinal transplantation (ITx) was performed orthotopically using FK506 immunosuppression. The distal about 20 cm segment of the allograft was exteriorized as a Thiry-Vella stoma for biopsies. Strain gauge (SG) force transducers were attached to the graft for real-time monitoring of graft motility. Pigs without ITx were used as controls (group 1). Rejection was classified into four groups by histologic findings: nonrejection (group 2), mild rejection (group 3), moderate rejection (group 4), and severe rejection (group 5). Migrating motor complex (MMC) phase III was analyzed for the following parameters: duration, amplitude, interval, motility index, velocity, and frequency of propagation. In group 2, all parameters were almost the same as those for group 1. In contrast, groups 4 and 5 showed most parameters significantly lower than those in group 1. In group 3, the contractility of the MMC was not significantly altered, but the frequency of the propagation was decreased significantly. In conclusion, graft motility detected by a real-time SG method correlated with the grade of mucosal histology. This method is useful to detect rejection at an early stage by examining the frequency of MMC propagation.

Effects of phosphodiesterase-III inhibitors on sevoflurane-induced impairment of rat diaphragmatic function.

BACKGROUND: Volatile anesthetics are known to cause diaphragmatic dysfunction using a whole body model. The first aim of the current study was to compare the impairing effect of halothane and sevoflurane on diaphragmatic contractile functions under unfatigued and fatigued conditions. The second purpose was to determine whether phosphodiesterase-III inhibitors can attenuate sevoflurane-potentiated reduction of contractility after fatigue. METHODS: Using rat-isolated muscle strips, diaphragmatic twitch characteristics and tetanic contractions were measured before and after muscle fatigue, which was induced by repetitive tetanic contraction with or without exposure to halothane (1-3 MAC) or sevoflurane (1-3 MAC). Diaphragmatic functions were further assessed with exposure to 3 MAC sevoflurane in the presence and absence of milrinone, or olprinone. Cyclic adenosine monophosphate (cAMP) concentrations in the fatigued diaphragm were also measured. RESULTS: Halothane (1-3 MAC) or sevoflurane (1-2 MAC) did not induce a direct inotropic effect under unfatigued and fatigued conditions. Sevoflurane at 3 MAC enhanced fatigue-induced impairment of twitch and tetanic tensions. Clinically relevant concentrations of olprinone improved the sevoflurane-induced potentiation of diaphragmatic dysfunction following fatigue, accompanied by restoration of diaphragmatic cAMP levels, although milrinone failed to do so. CONCLUSION: Our findings suggest that sevoflurane has a greater decreasing effect on diaphragmatic contractility after fatigue than halothane, and that the clinical dose of olprinone surmounts the disadvantage of sevoflurane in various conditions where diaphragmatic fatigue is predisposed.

Real-time monitoring for detecting rejection using strain gauge force transducers in porcine small bowel transplantation.

PURPOSE: The clinical results of small bowel transplantation (SBT) have not been satisfactory mainly because of the immunological barrier. It is important to detect the presence of and to perform adequate treatment of rejection as early as possible to improve graft survival. Therefore, we have established a pig model to monitor graft motility as a means to detect rejection in real time. METHODS: Orthotropic SBT was performed in 25 pigs using FK-506 (0.05 to 0.1 mg/kg/d) immunosuppression. The interdigestive motor patterns were evaluated using strain gauge force transducers (SG). Seven pigs without SBT were treated as controls (C). Animals that displayed migrating motor complex (MMC) activity as evidenced by duration, amplitude, and interval in the graft were alive more than 10 days with adequate oral feeding: the functional graft (FG) group. In contrast the rejection (R) group did not show these activities on data recorded within 10 days before death due to rejection. RESULTS: The FG group showed MMC propagated throughout the graft with all parameters almost the same as the control group except for the duration. In contrast, all parameters in the group R were significantly lower than those in group FG, suggesting that group R motility was obviously impaired by rejection. CONCLUSIONS: The SG method may afford real-time monitoring of transplanted bowel motility that could be useful to detect rejection after SBT.

Immunosuppressive effect of nucleoside-nucleotide-free diet in rat allogeneic small intestinal transplantation.

BACKGROUND: We evaluated the effects of nucleosides (NS) and nucleotides (NT) on the rejection of rat allogeneic small intestinal transplants. METHODS: A 2-cm segment of jejunum from fetal Fischer rats (RT-1(lvl)) was transplanted at day 19 of gestation into the abdominal wall of 7-week-old Lewis rats (RT-1(l)) by a nonvascular technique. Two weeks before transplantation, recipient rats were separated into an NS-NT-free group and an NS-NT-supplemented group. At 2 days after transplantation, histologic study of the grafts was performed with hematoxylin-eosin staining and interleukin-2 (IL-2) production estimated in recipient blood using an ELISA method. The morphologic findings were graded in a blind fashion on a scale of 0 to 4, with 0 indicating an intact intestinal structure. RESULTS: Mean plasma IL-2 levels of the NS-NT-free group were significantly lower than those of the NS-NT-supplemented group. The mean rejection score of the NS-NT-free group was also significantly lower than that of the NS-NT-supplemented group. CONCLUSIONS: Administration of an NS-NT-free diet reduces acute rejection in rat small intestinal transplantations.

Effects of omega-3 fatty acids in rat allogenic small intestinal transplantation.

The aim of this study was to estimate the effect of omega-3 fatty acids on the recipient and graft immune response after rat allogenic small intestinal transplantation. Seven-week-old Lewis rats were randomly assigned to one of three groups according to the diet received: an FO group (fish oil supplemented), an SB group (soy bean oil supplemented) or a control group (normal rat chow). The recipient Lewis rats were each given their respective group diet for 12 days, and then, on the 19th day of gestation, a 2 cm jejunum from the donor fetal Fischer rat was transplanted into the abdominal wall of the recipient rats using a non-vascular anastomotic technique. The recipient rats were killed on day 2 after transplantation, and the recipient plasma IL-2, IFN-gamma and IL-1 beta levels were determined. In addition, the histological findings of the graft were analyzed. The cytokine levels of the FO group were significantly lower than the other two groups. In order to determine the grade of rejection, the morphological findings were blindly graded on a scale of 0-4. The mean grade of the FO group was also significantly lower than the other two groups. Omega-3 fatty acids are therefore considered to have an immunosuppressive effect on rat allogenic small intestinal transplantation based on the recipient plasma IL-1 beta, TNF and IL-2 levels and the histological findings of the grafts.

The role of Kupffer cell oxidant production in early ethanol-induced liver disease.

Considerable evidence for a role of Kupffer cells in alcoholic liver disease has accumulated and they have recently been shown to be a predominant source of free radicals. Several approaches including pharmacological agents, knockout mice, and viral gene transfer have been used to fill critical gaps in understanding key mechanisms by which Kupffer cell activation, oxidant formation, and cytokine production lead to liver damage and subsequent pathogenesis. This review highlights new data in support of the hypothesis that Kupffer cells play a pivotal role in hepatotoxicity due to ethanol by producing oxidants via NADPH oxidase.

Delivery of IkappaB superrepressor gene with adenovirus reduces early alcohol-induced liver injury in rats.

Chronic alcohol administration increases gut-derived endotoxin in the portal blood, which activates Kupffer cells through nuclear factor kappaB (NF-kappaB) to produce toxic mediators such as proinflammatory cytokines, leading to liver injury. Therefore, a long-term intragastric ethanol feeding protocol was used here to test the hypothesis that NF-kappaB inhibition would prevent early alcohol-induced liver injury. Adenoviral vectors encoding either the transgene for IkappaB superrepressor (AdIkappaB-SR) or the bacterial beta-galactosidase reporter gene (AdlacZ) were administered intravenously to Wistar rats. Animals were fed a high-fat liquid diet with either ethanol or isocaloric maltose-dextrin (control) for 3 weeks. There was no significant difference in mean urine alcohol concentrations between the groups fed ethanol. IkappaB-SR expression was increased for up to 2 weeks after injection, but was undetectable at 3 weeks. NF-kappaB activation was increased by ethanol and associated with up-regulation of tumor necrosis factor alpha (TNF-alpha). These increases were blunted significantly up to 2 weeks by AdIkappaB-SR. Dietary alcohol significantly increased liver to body weight ratios and serum alanine transaminase (ALT) levels in AdlacZ-treated animals, effects that were blunted significantly in AdIkappaB-SR-treated rats. Ethanol caused severe steatosis, inflammation, and focal necrosis in AdlacZ-treated animals. These pathologic changes were significantly decreased by AdIkappaB-SR. The protective effects of IkappaB-SR were significant 2 weeks after injection, but were lost at 3 weeks when IkappaB-SR was no longer expressed. Ethanol increased 4-hydroxynonenal as a maker of oxidative stress in both AdlacZ and AdIkappaB groups. These data support the hypothesis that NF-kappaB inhibition prevents early alcohol-induced liver injury even in the presence of oxidative stress.

Initial intraorgan formation of mercapturic acid.

The disposition of S-benzyl-glutathione (BSG) in male Wistar rats was evaluated by the HPLC method to examine whether the kidney and liver contributed independently to the biosynthesis of S-benzyl-N-acetylcysteine (BNAc), a mercapturic acid (Chart 1). After intravenous injection, BSG was rapidly transported in both the kidney and the liver at a ratio of about 7:3. Simultaneously, a large amount of BNAc was found in both the kidney and the liver. In the kidney, S-benzyl-cysteine (BCys) reached a maximum concentration (Cmax) at 2 min after BSG injection, whereas BNAc reached Cmax within 3 to 5 min. The generation of BNAc was also observed in the liver. While renal BNAc reached Cmax within 3 to 5 min, hepatic BNAc reached Cmax around 5 min after BSG injection. Moreover, the elimination half-life of the BNAc after intravenous injection of the BSG was equivalent to that observed after intravenous injection of the BNAc itself. These results demonstrate that the kidney contributes to the initial intraorgan generation of BNAc and that this mercapturic acid is also synthesized in the liver and preferentially excreted into urine.

Metabolism of sulphobromophthalein I: positional isomers of sulphobromophthalein monoglutathione conjugate.

Three positional isomers of sulphobromophthalein glutathione monoconjugate (BSP-mGSH) were detected using a paired-ion HPLC method that employs triethylamine phosphate (TEA-H3PO4) as a pairing agent. To confirm that these compounds were glutathione (GSH) conjugates, sulphobromophthalein (BSP) was incubated with a four-fold volume of GSH under alkaline ammonium hydroxide. At least 6 metabolites (3 di-GSH conjugates and 3 isomers of mono-GSH conjugates) were produced under these conditions. The three mono-GSH conjugates were each purified and identified as compounds with a molecular weight of 1,020 according to FAB mass spectrometry results. Positional isomers of BSP-GSH were provisionally distinguished via the addition of the symbols alpha, beta and delta to the end of each abbreviation, to reflect the amount of isomers present. Thus, the isomer present in the largest quantity was termed BSP-mGSH(alpha), the second most abundant isomer was termed BSP-mGSH(beta) and the third was termed BSP-mGSH(delta). Interestingly, a species difference was recognized in that rat cytosol GSH S-transferase (GST) primarily produced BSP-mGSH(alpha), whereas guinea-pig cytosol generated BSP-mGSH(delta), BSP-mGSH(alpha) and BSP-mGSH(beta) equally and rabbit cytosol mainly produced BSP-mGSH(beta).

Metabolism of bucolome in rats. Stability and biliary excretion of bucolome N-glucuronide.

Bucolome (BCP) is a non-steroidal anti-inflammatory drug, which is used in the treatment of chronic articular rheumatism. Bucolome N-glucuronide (BCP-NG), a metabolite of BCP, is the first unique N-glucuronide of barbituric acid derivatives. First, the stability of BCP-NG in various pH aqueous solutions was studied. BCP-NG was quite unstable under neutral and acidic conditions, and is easily hydrolyzed to BCP. Based on these characteristics of BCP-NG, a simple, rapid and highly sensitive method for the simultaneous determination of BCP and BCP-NG with phenylbutazone (I.S.) in biological fluids was developed using high-performance liquid chromatography (HPLC). A reversed-phase ODS column was used for the separation of BCP, BCP-NG and I.S. A pharmacokinetic study for BCP and BCP-NG was carried out in male Wistar/ST rats following i.v. administration of BCP at a dose of 10 mg/kg body weight. The slow plasma elimination of BCP with time was shown. A major metabolite of BCP in bile was N-glucuronide. The cumulative amounts of BCP and BCP-NG in the bile over 8 h were approximately 2.4 +/- 1.4% and 12.6 +/- 2.3% of the dose, respectively. BCP and BCP-NG in the urine were 2.7 +/- 0.7% and 3.2 +/- 0.3% of the dose. Although BCP had a long half-life (over 8.5 h), the preliminary pharmacokinetic parameters (0-8 h) were determined: t 1/2, 8.52 +/- 1.96 h; AUC, 419.9 +/- 45.2 microg x h/ml; MRT, 3.29 +/- 0.11 h; CLtot, 5.93 +/- 0.54 ml/h; and Vdss, 19.5 +/- 1.3 l. These observations are the first pharmacokinetic findings for the N-glucuronide of the barbituric acid derivatives.

Influence of extracorporeal porcine liver perfusion on nonhuman primates: minimizing hemolysis improves subsequent survival.

The aim of this study is to detect and analyze risk factors of direct cross-circulation between porcine liver and nonhuman primates before a clinical application of extracorporeal liver perfusion (ECLP) as a liver-assist method. Porcine livers were perfused with baboon blood in an ECLP system. Six healthy baboons were directly connected to the ECLP system with continuous prostaglandin E(1) administration. Cross-circulation was terminated in the following circumstances: (1) hepatic arterial or portal perfusion pressures elevated to 200 or 60 mm Hg, respectively; (2) massive exudative bleeding from the graft surface; or (3) bile output decreased to less than 5 microL/h/g of liver weight. In case 1, cross-circulation was continued for 10 hours. Severe macroscopic hemolysis occurred, and serum hemoglobin (s-Hb) concentration reached a peak of 47 mg/dL. The baboon died of acute renal failure 2 days later. Histological study of the perfused porcine liver showed marked microthrombi formation. In 3 of the later 5 cases, cross-circulation was discontinued when mild macroscopic hemolysis was observed. The duration of the 5 cross-circulations was maximally 6 hours (mean, 4.4 +/- 1.2 [SD] hours). Mean s-Hb concentration in the 5 cases was elevated to 14.8 +/- 5.8 mg/dL at the end of cross-circulation and decreased to the baseline level within 24 hours. These 5 baboons survived without organ dysfunction or immunologic disturbance. When severe hemolysis is avoided, direct cross-circulation using the ECLP system can be achieved without serious complications in nonhuman primates.

Effects of prostaglandin E(1) on the efficacy of xenogeneic extracorporeal pig liver perfusion in a canine model of acute liver failure.

Xenogeneic extracorporeal liver perfusion (ECLP) has the potential to become an important tool in the management of patients with severe liver failure. We previously showed that xenogeneic pig liver perfusion may be prolonged for up to 9 hours by the administration of prostaglandin E(1) (PGE(1)). In this study, we used a canine model of acute liver failure to evaluate the effects of PGE(1) on the efficacy of ECLP as a liver-assist device. Liver failure was surgically induced in 12 beagle dogs, with a control group (group 1, n = 4) not connected to the ECLP circuit. Direct cross-circulation between the dogs and the ECLP circuit using a pig liver was performed without (group 2, n = 4) or with (group 3, n = 4) continuous administration of PGE(1) through the portal vein of the pig liver. The duration of cross-circulation in group 3 (9.4 +/- 1.2 hours) was significantly longer than in group 2 (4.3 +/- 1.0 hours). In addition, elevation of blood ammonia, total bile acid, and hyaluronic acid levels was less marked in group 3 compared with the other 2 groups. The ratio of branched-chain amino acids to aromatic amino acids was also improved in group 3. The mean survival time in group 3 (26.6 +/- 0.4 hours) was significantly longer than in group 1 (15.5 +/- 1.3 hours) or group 2 (17.1 +/- 2.9 hours). Continuous administration of PGE(1) to xenogeneic ECLP resulted in a significant improvement in both liver function and survival time of dogs with surgically induced liver failure.

Overexpression of manganese superoxide dismutase prevents alcohol-induced liver injury in the rat.

Mitochondria are thought to play a major role in hepatic oxidative stress associated with alcohol-induced liver injury. Thus, the hypothesis that delivery of the mitochondrial isoform of superoxide dismutase (Mn-SOD) via recombinant adenovirus would reduce alcohol-induced liver injury was tested. Rats were given recombinant adenovirus containing Mn-SOD (Ad.SOD2) or beta-galactosidase (Ad.lacZ) and then fed alcohol enterally for 4 weeks. Mn-SOD expression and activity of Ad.SOD2 in liver mitochondria of infected animals was increased nearly 3-fold compared with Ad.lacZ-infected controls. Mitochondrial glutathione levels in Ad.lacZ-infected animals were decreased after 4 weeks of chronic ethanol, as expected, but were unchanged in Ad.SOD2-infected animals. Alanine aminotransferase was elevated significantly by ethanol, an effect that was prevented by Ad.SOD2. Moreover, pathology (e.g. the sum of steatosis, inflammation, and necrosis) was elevated dramatically by ethanol in Ad.lacZ-treated rats. This effect was also blunted in animals infected with Ad.SOD2. Neutrophil infiltration was increased about 3-fold in livers from both Ad.lacZ- and Ad.SOD2-infected rats by ethanol treatment. Moreover, ESR-detectable free radical adducts in bile were increased about 8-fold by ethanol. Using (13)C-labeled ethanol, it was determined that nearly 60% of total adducts were due to the alpha-hydroxyethyl radical adduct. This increase in radical formation was blocked completely by Ad.SOD2 infection. Furthermore, apoptosis of hepatocytes was increased about 5-fold by ethanol, an effect also blocked by Ad.SOD2. Interestingly, tumor necrosis factor-alpha mRNA was elevated to the same extent in both Ad.lacZ- and Ad.SOD2-infected animals follows ethanol exposure. These data suggest that hepatocyte mitochondrial oxidative stress is involved in alcohol-induced liver damage and likely follows Kupffer cell activation, cytokine production, and neutrophil infiltration. These results also support the hypothesis that mitochondrial oxidant production is a critical factor in parenchymal cell death caused by alcohol.

Influence of humoral immunoreaction on hepatic nonparenchymal cells in ex situ xenoperfused rat livers.

BACKGROUND: The influence of xenogeneic humoral immunoreaction on hepatic nonparenchymal cells (NPCs) was evaluated ex situ in xenoperfused rat livers. METHODS: Isolated rat livers were perfused via the portal vein (PV) for 240 min. The perfusates consisted of fresh rat blood (group 1), fresh human blood (group 2), and fresh human blood containing 5 microg/mL soluble complement receptor type 1 (Group 3). RESULTS: Deposition of human IgM and C(5b-9) complement was observed in group 2, although only human IgM deposition was detected in group 3. Portal vein pressure in group 2 rose drastically during the first 10 min. Creatine kinase BB component gradually increased in all groups, followed by an elevation in alanine aminotransferase and both parameters were significantly higher in group 2 than in groups 1 and 3. In group 2, platelet thrombi in the peripheral PVs and periportal hemorrhage were observed after 10 min, and massive necrosis around the central veins after 240 min; these changes were not observed in group 1 or 3. Production of tumor necrosis factor alpha and alpha interferon and expression of intercellular adhesion molecule 1 (ICAM-1) were lower in group 2 than in groups 1 and 3. In group 2, there were negative areas for ICAM-1 and tumor necrosis factor alpha staining around the central veins after 240 min, which were consistent with necrotic areas. CONCLUSIONS: In xenoperfused rat livers, humoral mediators initially caused the disturbance of microcirculation, which would induce long ischemia in the pericentral areas, resulting in massive necrosis. NPC necrosis may be responsible for less production of cytokines and adhesion molecules in the xenoperfused livers.

Toll-like receptor 4 is involved in the mechanism of early alcohol-induced liver injury in mice.

Chronic alcohol administration increases gut-derived endotoxin in the portal blood, which activates Kupffer cells and causes liver injury. Mice (C3H/HeJ) with mutations in toll-like receptor 4 (TLR4) are hyporesponsive to endotoxin. To test the hypothesis that TLR4 is involved in early alcohol-induced liver injury, the long-term intragastric ethanol feeding protocol developed by Tsukamoto and French for rats was adapted to mice. Animals with nonfunctional TLR4 and wild-type mice (C3H/HeOuJ) were compared. Two-month-old female mice were fed a high-fat liquid diet with either ethanol or isocaloric maltose-dextrin as control continuously for 4 weeks. There was no difference in mean urine alcohol concentrations between the groups. Dietary alcohol significantly increased liver-to-body weight ratios and serum alanine transaminase (ALT) levels in wild-type mice (109 +/- 18 U/L) over high-fat controls (40 +/- 3 U/L), effects that were blunted significantly in mice with a mutation of TLR4 (55 +/- 9 U/L). While no significant pathologic changes were observed in high-fat controls, dietary ethanol caused steatosis, mild inflammation, and focal necrosis in wild-type animals (pathology score = 5.2 +/- 1.2). These pathologic changes were significantly lower in TLR4-deficient mice fed ethanol (score = 2.0 +/- 1.3). Endotoxin levels in the portal vein were increased significantly after 4 weeks in both groups fed ethanol. Moreover, ethanol increased tumor necrosis factor alpha (TNF-alpha) mRNA expression in wild-type, but not in TLR4-deficient, mice. These data are consistent with the hypothesis that Kupffer cell activation by endotoxin via TLR4 is involved in early alcohol-induced liver injury.