Transoral ultrasonographic evaluation of carotid flow in predicting cerebral hemodynamics after carotid endarterectomy

PURPOSE

We investigated whether measurement of blood flow in the extracranial distal internal carotid artery (ICA) by transoral carotid ultrasonography (TOCU) can predict the cerebral hemodynamics and the hemodynamic effect of carotid endarterectomy (CEA) in patients with unilateral carotid stenosis.

METHODS

Forty-nine patients with unilateral ICA stenosis who underwent CEA were studied. Preoperative blood flow in the poststenotic portion of the extracranial ICA was studied by using TOCU. Regional cerebral blood flow (rCBF) and vasoreactivity to acetazolamide (VR) in the territory of the middle cerebral artery were investigated by using single-photon emission CT (SPECT) before, 2 weeks after, and 3 months after CEA.

RESULTS

Doppler flow velocities in the extracranial distal ICA measured transorally by TOCU correlated with baseline as well as postacetazolamide rCBF in the ipsilateral side (regression analysis, P < .05). Diameter and blood flow volume in the extracranial distal ICA were associated with ipsilateral postacetazolamide rCBF and VR (regression analysis, P < .05). When the patients were divided into 2 groups according to the ICA volume flow distal to a carotid stenosis, group I < 3.5 mL/s and group II > 3.5 mL/s, ipsilateral postacetazolamide rCBF in group I was significantly lower than that in group II (P = .008). Ipsilateral postacetazolamide rCBF (analysis of variance [ANOVA], P = .02) and VR (ANOVA, P = .03) significantly improved after CEA for 3 months in group I but not in group II.

CONCLUSION

TOCU can detect the decrease in poststenotic flow of the distal extracranial ICA that is indicative of impaired intracranial hemodynamics and predictive for improvement of cerebral blood flow after CEA in patients with unilateral carotid stenosis.

Enantioselective intramolecular aromatic [4 + 4] photocycloaddition in crystalline state: parameters for reactivity

Photoreactivity of seven 9-anthryl-N-(naphthylcarbonyl)carboxamide derivatives, 1a-g, in their intramolecular [4 + 4] photocycloadditions in solid state is discussed on the basis of their single-crystal X-ray analyses. The distances (d(1) and d(2)) between the two carbon atoms to be reacted, the angles (theta(1) and theta(2)), and the torsion angle (theta(3)) between the anthracene and naphthalene rings were chosen as structural parameters for reactivity. For 1a and 1e, the first example of absolute asymmetric synthesis in [4 + 4] photocycloaddition was attained. [reaction: see text]

Biliary reconstruction in living donor liver transplantation with dye injection leakage test and without stent use

Biliary complication remains a significant source of morbidity and mortality in living donor liver transplantation. From October 1996 to December 1999, 34 patients underwent 35 living donor liver transplantations at Kyushu University Hospital. In the initial twenty cases, anastomotic internal stents were placed. In the most recent fifteen cases, no internal stent was inserted and routine postreconstruction dye injection leakage tests were administered. In recipient biliary reconstruction, hepaticojejunostomy was performed using interrupted sutures without an anastomotic stent. After an intestinal clamp was applied at the anal side of the hepaticojejunostomy, leakage test was done using diluted indigocarmine solution injected into the jejunal loop lumen. Two (13%) of the fifteen recent patients suffered from biliary complications, whereas eight patients (40%) from the former twenty patients suffered from biliary complications. We conclude that the use of the stent was not useful, but the application of the dye injection leakage test was useful.

Small graft for living donor liver transplantation

OBJECTIVE

To evaluate the impact of graft size on recipients in living donor liver transplantation (LDLT) to establish a clinical guideline for the minimum requirement.

SUMMARY BACKGROUND DATA

Although the minimum graft size required for LDLT has been reported to be 30% to 40% of graft volume (GV)/standard liver volume (SLV), the safety limit of the graft size was unknown.

METHODS

A total of 33 cases of LDLT, excluding auxiliary transplantation, were reviewed with a minimum observation period of 4 months. The 33 patients were divided into three groups according to GV/SLV: medium-size graft group, small-size graft group, and extra-small graft group. The effect of GV/SLV on graft function, graft regeneration, and survival was evaluated.

RESULTS

The overall patient survival rate was 94% at a mean follow-up of 15 months with a minimum observation period of 4 months. There were no statistically significant differences in postoperative bilirubin clearance, alanine aminotransferase, prothrombin time, and frequency of postoperative complications among the three groups. One week after transplantation, the regeneration rate (GV at 1 week/harvested GV) in the extra-small and small groups was significantly higher than that of the medium group. The graft and patient survival rates were both 100% in the extra-small group, 75% and 88% in the small group, and 90% and 95% in the medium group.

CONCLUSIONS

Small-for-size grafts less than 30% of SLV can be used with careful intraoperative and postoperative management until the grafts regenerate.

Trapping of 1,8-biradical intermediates by molecular oxygen in photocycloaddition of naphthyl-N-(naphthylcarbonyl)carboxamides; formation of novel 1,8-epidioxides and evidence of stepwise aromatic cycloaddition

The photocycloaddition reaction of naphthyl-N-(naphthylcarbonyl)carboxamides (1) was examined under argon and oxygen atmospheres. In addition to the [2 + 2] and [4 + 4] cycloadducts, 3 and 4, respectively, novel 1,8-epidioxides (5) were formed under oxygen atmosphere. The transient absorption at lambda max of 360 nm with the lifetime of 360 ns was observed by laser flash photolysis of 1c and was interpreted as the absorption of biradical intermediate 2. On the basis of the anti stereochemistry of 5, which was different from that of the major [4 + 4] cycloadducts, syn-4, it was deduced that equilibrium between biradical intermediates syn-2 and anti-2 would exist. Retro [2 + 2] cycloaddition of 3 was responsible for the efficient trapping of the biradical intermediate with molecular oxygen. The photocycloaddition of the anthryl derivatives, 9-anthryl-N-(methylethyl)-N-(naphthylcarbonyl)carboxamides (7), afforded the [4 + 4] cycloadducts (8) exclusively in a quantitative yield even under oxygen atmosphere. The absence of trapping with molecular oxygen was interpreted to be due to the lack of retro [4 + 4] cycloaddition of 8.

The impact of donor age on living donor liver transplantation

BACKGROUND

The impact of the age of the donor on the outcome of living related liver transplantation is yet to be clarified.

METHODS

During October 14, 1996 and December 20, 1999, 34 living related liver transplantations were performed. Of these, 26 cases were performed using the extended left lobe graft, which were classified into three groups; younger donor group (group Y, donor age < 30, n = 7), middle-aged donor group (group M, 30 < or = donor age <50, n=13), and older donor group (group O, donor age < 50, n = 6). Early allograft function and regeneration were compared between these groups.

RESULTS

There was no difference in standard liver volume, and predicted or harvested graft size between the three groups. Although serum transaminase and total bilirubin levels within postoperative day 7 were not different between the groups, the prothrombin time on postoperative day 3 was significantly longer in group O than in group Y. One week after transplantation, group Y had significantly greater graft/standard liver volume ratio than group O, and greater graft volume than group M and O. One month after transplantation, however, there was no significant difference in such graft size parameters between the groups. Graft and patient survival were comparable between the three groups.

CONCLUSION

Although function and regeneration of the allografts from older donors in living donor liver transplantation is worse than those of their younger counterparts, the outcome is not affected by the age of the liver.

Domino liver transplantation from a living related donor

BACKGROUND

Although domino liver transplantations (OLT) from cadaveric donors have been performed in about 50 cases since 1995, only one case in the Japanese literature has been reported on a domino OLT from a living related donor. The difficulties of the later surgery lie in the small size of the graft volume and the short length of the vascular cuffs in the graft.

METHODS

The left lobe graft was procured from a 43-year-old younger brother of a familial amyloidotic polyneuropathy (FAP) patient. Next, the left lobe graft (510 g, 44% of the estimated standard liver volume of the FAP patient) was implanted into the 48-year-old female FAP patient. At surgery for the FAP patient, a sufficient length of the vascular cuffs was secured by an extended left lobe resection, although the right lobe graft was able to maintain sufficient vascular cuffs. The right lobe graft (720 g, 54% of the recipient's estimated standard liver volume) was then implanted in the 43-year-old male patient with liver cirrhosis and hepatocellular carcinoma (stage IV-A).

RESULTS

The two recipients were discharged from the hospital 1 month after OLT. At 7 months after OLT, they are both doing well and the domino recipient is free of any tumor recurrence.

CONCLUSION

A domino OLT from the living related donor can therefore be done safely when careful attention is paid to the graft volume and the length of the vascular cuffs for anastomosis.

Phosphatidic acid is a potent and selective inhibitor of protein phosphatase 1 and an inhibitor of ceramide-mediated responses

In the present study, we report that phosphatidic acid (PA) functions as a novel, potent, and selective inhibitor of protein phosphatase 1 (PP1). The catalytic subunit of PP1alpha was inhibited by PA dose-dependently in a noncompetitive manner with a K(i) value of 80 nM. The inhibition by PA was specific to PP1 as PA failed to inhibit protein phosphatase 2A (PP2A) or PP2B. Furthermore, PA was the most effective and potent inhibitor of PP1 compared with other phospholipids. Because we recently showed that ceramides activated PP1, we next examined the effects of PA on ceramide stimulation of PP1. PA inhibited both basal and ceramide-stimulated PP1 activities, and ceramide showed potent and stereoselective activation of PP1 in the presence of PA. Next, the effects of PA on ceramide-induced responses were examined. Molt-4 cells took up PA dose- and time-dependently such that by 1 and 3 h, uptake of PA was 0.37 and 0. 65% of total PA added, respectively. PA at 30 microM and calyculin A at 10 nM (an inhibitor of PP1 and PP2A at low concentrations), but not okadaic acid at 10 nM (a PP2A inhibitor at low concentrations) prevented poly(ADP-ribose) polymerase proteolysis induced by C(6)-ceramide. Moreover, the combination of PA with okadaic acid prevented retinoblastoma gene product dephosphorylation induced by C(6)-ceramide. These data suggest that PA functions as a specific regulator of PP1 and may reverse or counteract those effects of ceramide that are mediated by PP1, such as apoptosis and retinoblastoma gene product dephosphorylation.

Long chain ceramides activate protein phosphatase-1 and protein phosphatase-2A. Activation is stereospecific and regulated by phosphatidic acid

The search for potential targets for ceramide action led to the identification of ceramide-activated protein phosphatases, which include protein phosphatase-2A (PP2A) and protein phosphatase-1 (PP1) with roles in regulating apoptosis and cell growth. Thus far, in vitro studies on ceramide-activated protein phosphatases have been restricted to the use of short chain ceramides, limiting the extent of mechanistic insight. In this study, we show that the long chain D-erythro-C18-ceramide activated PP2A (AB'C trimer), PP2Ac (catalytic subunit of PP2A), and PP1gammac and -alphac (catalytic subunits of PP1gamma and -1alpha isoforms, respectively) 2-6-fold in the presence of dodecane, a lipid-solubilizing agent, with 50% maximal activation achieved at approximately 10 microM D-erythro-C18-ceramide. The diastereoisomers of D-erythroC18-ceramide, D-threo-, and L-threo-C18-ceramide, as well as the enantiomeric L-erythro-C18-ceramide, did not activate PP1 or PP2A, but they inhibited PP1 and PP2A activity. The addition of phosphatidic acid decreased the basal activity of PP1c but also increased the stimulation by D-erythro-C18-ceramide from 1.8- to 2. 8-fold and decreased the EC50 of D-erythro-C18-ceramide to 4.45 microM. The addition of 150 mM KCl decreased the basal activity of PP1 and the dose of D-erythro-C18-ceramide necessary to activate PP1c (EC50 = 6.25 microM) and increased the ceramide responsiveness up to 10-17-fold. These studies disclose stereospecific activation of PP1 and PP2A by long chain natural ceramides under near physiologic ionic strengths in vitro. The implications of these studies for mechanisms of ceramide action are discussed.

Cutaneous responsiveness of lumbar spinal dorsal horn neurons is reduced by general anesthesia, an effect dependent in part on GABAA mechanisms

Extracellular activity was recorded from single spinal dorsal horn neurons in both chronic cat and acute rat models. This was done to define the effects of anesthesia on the processing of sensory information elicited by nonnoxious tactile stimulation of peripheral receptive fields (RFs). In the chronic cat model, baseline data were obtained in physiologically intact, awake, drug-free animals before anesthetic administration (halothane 1.0-2.0%). This made it possible to compare and contrast activity of each cell in the drug-free and anesthetized state. Halothane effects were confirmed in the acute rat model (anesthetized, spinally transected, and in some cases decerebrate). In addition, the gamma-aminobutyic acid-A (GABAA)-receptor antagonist picrotoxin (2 mg/kg) was administered intravenously to verify that the observed halothane effect on spinal dorsal horn neurons was mediated by an interaction with GABAA-receptor systems. Halothane effects on three separate measures of response to nonnoxious tactile stimuli were observed in the chronic cat model. Halothane produced a significant, dose-dependent reduction in the low-threshold RF area of the neurons studied. Halothane also caused a significant reduction in neuronal response to RF brushing (dynamic stimulus) and to maintained contact with the RF (static stimulus). A dose dependency was not observed with these latter two effects. Neurons with a predominant rapidly adapting response seemed to be less susceptible to halothane suppression than slowly adapting cells. In the acute rat model an increase in halothane caused a reduction in neuronal response similar to that seen in the cat. The intravenous administration of 2 mg/kg of picrotoxin by itself caused no significant change in RF size or response to brushing. However, the same amount of picrotoxin did cause a 50% reversal of the halothane-induced reduction in RF size without causing a significant change in the halothane effect on response to RF brushing. In contrast to work recently reported in a chronic sheep model, halothane causes a significant reduction in spinal dorsal horn neuronal response to tactile stimulation of peripheral RFs. This effect is caused by, in part, but not exclusively, to GABAA-neurotransmitter systems. However, the relative influence of GABAA systems may vary with the nature of the stimulus.

Purification and characterization of ceramide-activated protein phosphatases

Ceramide has emerged as a potential regulator of diverse cellular functions, and a few direct targets have been identified for its action including protein kinases and phosphatases. In this study, we have purified the predominant ceramide-activated protein phosphatase (CAPP) from rat brain. Utilizing a novel chromatographic approach, CAPP was purified to near homogeneity using hydrophobic interaction chromatography on phenyl Sepharose followed by anion-exchange chromatography on MonoQ. The purified protein was composed of three major bands on SDS-polyacrylamide gel electrophoresis which comigrated with the three subunits of heterotrimeric PP2A. Immunologic studies further identified CAPP to be composed predominantly of heterotrimeric AB'C and ABalphaC as well as heterodimeric PP2A (AC), where C is the catalytic subunit, and A and B are regulatory subunits. These results were also supported by the coelution of CAPP with trimeric and dimeric PP2A on size-exclusion chromatography. These studies provide a convenient and efficient method for the isolation of trimeric and dimeric PP2A, and they allow the biochemical investigation of CAPP.

Purification and characterization of ceramide-activated protein phosphatases

Ceramide has emerged as a potential regulator of diverse cellular functions, and a few direct targets have been identified for its action including protein kinases and phosphatases. In this study, we have purified the predominant ceramide-activated protein phosphatase (CAPP) from rat brain. Utilizing a novel chromatographic approach, CAPP was purified to near homogeneity using hydrophobic interaction chromatography on phenyl Sepharose followed by anion-exchange chromatography on MonoQ. The purified protein was composed of three major bands on SDS-polyacrylamide gel electrophoresis which comigrated with the three subunits of heterotrimeric PP2A. Immunologic studies further identified CAPP to be composed predominantly of heterotrimeric AB'C and ABalphaC as well as heterodimeric PP2A (AC), where C is the catalytic subunit, and A and B are regulatory subunits. These results were also supported by the coelution of CAPP with trimeric and dimeric PP2A on size-exclusion chromatography. These studies provide a convenient and efficient method for the isolation of trimeric and dimeric PP2A, and they allow the biochemical investigation of CAPP.

Early detection of recurrent hepatocellular carcinoma

BACKGROUND/AIMS

Early detection and treatment of recurrent hepatocellular carcinoma (HCC) are keys to patient survival after hepatic resection. In attempts at early detection, we make use of the alpha-fetoprotein (AFP) test every month and abdominal ultrasound (US) and computed tomography (CT) are carried out every three months after hepatectomy. The objective of the present study was to evaluate the most appropriate interval for follow-up re-examinations after resection for HCC.

PATIENTS AND METHODS

Eighty-five patients with recurrent HCC were divided into two groups according to the state of the tumor when recurrence was detected: Group I (n = 70); tumor size < or = 2.0 cm, and group II (n = 15); tumor size > or = 2.1 cm. Clinicopathological comparisons were made between the two groups.

RESULTS

AFP positivity in group I was significantly lower than group II at the time of recurrence. Rates of extrahepatic intra-abdominal recurrences, i.e. recurrence at the surgical stump and in the abdominal cavity and lymph nodes around the liver, were more frequent in group II than in group I (47% vs 4%; p < 0.001). The average tumor size was larger in 10 patients with extrahepatic intra-abdominal recurrence than in 75 patients with intrahepatic recurrence (3.4 +/- 2.0 vs 1.6 +/- 0.6 cm; p < 0.0001). There was a statistically significant difference regarding the histological grade of initial HCC between the two patterns of recurrence.

CONCLUSIONS

Measurements of AFP were seen to have limited value for detecting recurrence, at an early stage. Close postoperative follow-up, including bedside US in the outpatient clinic, should be carried out when the initial HCC is histologically less differentiated HCC.

Tuberculosis following liver transplantation: report of a case and review of the literature

We report on a 44-year-old man who developed tuberculosis 4 months after liver transplantation. The diagnosis was confirmed using a polymerase chain reaction (PCR) technique in bronchial alveolar lavage (BAL) fluid, and the patient was successfully treated by reducing his immunosuppression and administering antituberculous drugs. The patient became afebrile 20 days after starting antituberculous therapy and remains well at home. A review of the literature revealed that tuberculosis after liver transplantation is a rare complication with a reported mortality rate of as high as 40%. The mortality is highest for patients who become symptomatic within 3 months after transplantation (83% vs 0%, P < 0.01; Fisher's exact test) and for those with an interval between the initial symptom and diagnosis of more than 2 weeks (71% vs 0%, P < 0.05). Early diagnosis is, therefore, essential for successful resolution of tuberculosis after liver transplantation.

Incidence of methicillin-resistant Staphylococcus aureus (MRSA) isolation in a skilled nursing home: a third report on the risk factors for the occurrence of MRSA infection in the elderly

A case control study was carried out in order to evaluate the various factors which may influence the occurrence of methicillin-resistant Staphylococcus aureus (MRSA) infections in a skilled nursing home. From April 1991 to March 1994, bacterial cultures were performed in 55 out of 102 residents in a nursing home based on various clinical aspects. We divided 102 residents into following three groups; (1) the MRSA group (n = 10), residents whose materials for bacterial culture were positive for MRSA, (2) the non-MRSA group (n = 45), residents whose specimens were negative for MRSA but positive for other bacteria, (3) the control group (n = 47), residents who did not have to undergo a bacterial culture because they were free from moderate and severe infectious diseases. Compared with the control group, the activities of daily living score and the serum albumin level were significantly lower in the MRSA group and the non-MRSA group at the beginning of the study. In contrast, the number of antibiotics used prior to the bacterial culture and the proportion of hospitalization within 6 months prior to the bacterial culture were significantly larger in the MRSA group than in either the non-MRSA group, or the control group. These results thus suggest that a low activities of daily living score, the use of many kinds of antibiotics and a recent previous hospitalization may be risk factors of MRSA infection in a nursing home environment.

Thromboxane A2 in preservation-reperfusion injury: the effect of thromboxane A2 synthetase inhibitor

It has been suggested that thromboxane A2 (TXA) plays important roles in preservation/reperfusion organ injury. In this report, we investigated the prostanoid release from the liver and the effect of a selective TXA synthetase inhibitor (E)-3-[p-(1H-imidazol-yl-methyl)-phenyl]-2-propenoic acid, OKY046) during cold preservation and after reperfusion. Rat livers were preserved in lactated Ringer's solution at 4 degrees C for 2, 4, and 6 hr and perfused with oxygenated Krebs-Henseleit buffer using recirculating perfusion system, and prostanoids were measured during cold preservation and after reperfusion. OKY046 and a novel TXA receptor antagonist [(9,11), (11,12)-Dideoxa-9a, 11a-dimethyl-methano-11,12-methano-13,14-dihydro-13-aza-14-oxo-15-cyclo pentyl-16,17,18,19,20-pentanor-15-epi-TXA, ONO3708] were added into the preservation solution and perfusate. Along with the preservation time, both the production and release of TXA was observed to increase; however, almost all the produced TXA was stored in the liver tissue. Afterwards, the stored TXA was released into perfusate in 15 min after reperfusion. OKY046 significantly decreased both the production and release of TXA. In addition, OKY046 improved the histological damage and trypan blue uptake of liver cells. Our results demonstrate that TXA, stored in the liver during preservation, might therefore be a potential trigger of reperfusion injury, and as a result, OKY046 reduces reperfusion injury by decreasing the production of TXA during preservation.

Tolerance of the cirrhotic liver to cold ischemia: ex vivo analysis in rats

We investigated the viability of rat cirrhotic livers preserved cold using an isolated rat liver perfusion model. Cirrhosis was induced by intravenous thioacetamide injection. Normal and cirrhotic livers were reperfused immediately or following 6 h of preservation through the portal vein with Krebs-Henseleit buffer and hyaluronic acid added. Cirrhotic livers with short cold ischemia showed higher portal venous resistance than their normal counterparts (p < 0.05), while cirrhotic livers preserved for 6 h exhibited marked elevation of the portal venous resistance as compared with their fresh counterparts or normal liver preserved cold for 6 h (p < 0.05). Similarly, the oxygen consumption of cirrhotic livers with short cold preservation was lower than that of normal livers (p < 0.05), which was further reduced by 6 h of cold preservation (p < 0.05). The bile output was not different between normal and cirrhotic livers. The sinusoidal endothelial cell function of cirrhotic livers as assessed by the clearance of hyaluronic acid was impaired even after a short period of cold ischemia. Histologically, cirrhotic livers showed severe sinusoidal endothelial cell damage, hepatocellular swelling, and marked septal edema which became more prominent by cold preservation. We conclude that the viability of the cirrhotic liver is impaired even by a short cold exposure, and that the prolongation of cold ischemia of the cirrhotic liver leads to further deterioration of the viability.

Halothane effects on low-threshold receptive field size of rat spinal dorsal horn neurons appear to be independent of supraspinal modulatory systems

Recent evidence strongly supports the importance of spinal sites of action for the ability of general anesthetic agents to block response to noxious stimuli. This study was designed to examine possible spinal anesthetic effects on non-noxiously evoked activity. Three groups of rats were prepared for acute experiments in which the response of spinal dorsal horn neurons to low threshold receptive field (RF) stimulation was evaluated. In each animal in each group extracellular activity was recorded from a single spinal dorsal horn neuron. A low-threshold RF of each neuron and, at times, the sensitivity to low-threshold stimulation of multiple sites in the RF were determined under baseline conditions (light anesthesia or decerebrate). In Group 1, reversible cooling of the thoracic spinal cord in the presence of either 0.5% or 1% halothane anesthesia caused no change in RF size. However, an increase from 0.5% to 1% halothane caused a 53% decrease in RF size both in the presence and absence of a reversible cold block of the spinal cord. In Group 2, animals with spinal cords transected at the thoracic level had a similar change in low-threshold receptive field size (52%) when halothane concentrations were increased from 0.5% to 1%. Testing sensitivity within the RF areas indicated that the silenced areas at the fringe of the receptive field could still elicit activation of spinal dorsal horn neurons but at a higher threshold. In the final group of animals, decerebration and spinal cord transection allowed us to compare effects of 0.5% and 1% halothane with an anesthetic free baseline. Here, again, a dose-dependent reduction in RF area was observed although the baseline RFs were significantly smaller than those in Groups 1 and 2. These results demonstrate that the reduction in low-threshold receptive field size due to the administration of the inhalation anesthetic halothane occurs in the absence of descending modulation from supraspinal sites. This implicates the spinal dorsal horn as a potentially important site of action for general anesthetics. These results also support the spinal cord as an important tool to study the pharmacology responsible for anesthetic effects on sensory processing.

Effect of propofol on spinal dorsal horn neurons. Comparison with lack of ketamine effects

BACKGROUND

Pentobarbital reduces low-threshold receptive field (RF) size and enhances responses of some spinal dorsal horn neurons to noxious stimulation in cats. To better understand the effects of general anesthetics on spinal sensory processing, this study was designed to determine if intravenous propofol and ketamine have similar effects.

METHODS

Spinal dorsal horn neuronal responses to RF stimulation were observed in physiologically intact, awake, drug-free cats. After baseline observations were made, the effects of propofol (7.5 or 10 mg/kg intravenous) or ketamine (10 mg/kg intravenous) on those neuronal responses were observed.

RESULTS

Propofol is capable of producing a profound reduction in low-threshold RF size. Propofol also depressed neuronal responses to non-noxious and noxious RF stimulation in many of the neurons tested. Ketamine was not observed to produce any change in either RF size or neuronal response to non-noxious RF stimulation.

CONCLUSIONS

General anesthetics that interact with gamma aminobutyric acid receptors may significantly depress low-threshold sensory information within the spinal dorsal horn. This may contribute to anesthetic-induced loss of sensation. Lack of a ketamine effect suggests an absence of n-methyl-d-aspartate receptor involvement in spinal dorsal horn processing of low threshold sensory information.

Partial hepatic grafting: porcine study on critical volume reduction

BACKGROUND

The safe limit of volume reduction in partial hepatic transplantation, including extracorporeal hepatic resection, remains to be clarified. This study evaluated such a limit and pathologic features associated with transplantation of a less than critical volume.

METHODS

Partial hepatic grafting was performed in a porcine orthotopic autotransplantation model. According to the remnant liver volume, animals were classified into three groups: group 1, 73.8% +/- 4.2% (SD); group 2, 52.6% +/- 6.7%; and group 3, 29.4% +/- 6.7% of the whole liver (n = 5 each).

RESULTS

Three-day survival was achieved in five (100%), four (80%), and zero animals, respectively. All animals in group 3 died of graft nonfunction; their intraoperative clearance of the total bile acids was significantly worse than the other groups (p < 0.01). After operation the clearance of the total bile acids and hyaluronic acid, which is selectively cleared by hepatic endothelial cells, was significantly better in group 1 than group 2 (p < 0.01 and < 0.05, respectively). On histologic examination postperfusion biopsy specimens of group 3 exhibited severe ischemic changes and portosinusoidal hyperemia, whereas that of groups 1 and 2 exhibited only mild ischemic damages.

CONCLUSIONS

Transplantation of less than 30% of expected full liver volume could lead to primary graft nonfunction after partial hepatic grafting.

Low-threshold neuronal activity of spinal dorsal horn neurons increases during REM sleep in cats: comparison with effects of anesthesia

1. Cats were prepared for chronic recordings from the lumbar enlargement of the spinal dorsal horn. At the beginning of each recording session, a tungsten microelectrode was advanced through the dura in a physiologically intact, awake, drug-free animal, until amplitude discrimination provided a single neuron with a receptive field on the hindquarters. 2. Extracellular recordings of activity of each neuron were made during receptive field stimulation with tactile and thermal nonnoxious and noxious stimuli. 3. Baseline responses obtained in the awake state were compared with responses of the same neurons during slow-wave or rapid-eye-movement (REM) sleep. In a subpopulation of neurons, the effects of anesthesia (propofol, 7.5 mg/kg iv) were observed after the completion of sleep studies. 4. The low-threshold receptive fields of the seven neurons studied during REM sleep were all increased in size when compared with the baseline value. The average increase was 52.6% (range 26.2-96.7%). 5. The low-threshold receptive fields of the seven neurons studied during REM sleep were reduced by propofol anesthesia by an average of 49.1% (range 29-74%). 6. Neuronal response to receptive field brushing was observed in 15 neurons during REM sleep. The effect of propofol on receptive field brushing was observed in 8 of those neurons. In only one of those eight neurons were the effects of REM sleep and anesthesia in the same direction. 7. Changes in neuronal responses were less consistent during slow-wave sleep but still differed from changes induced by propofol.(ABSTRACT TRUNCATED AT 250 WORDS)

Visceral antinociceptive effects of spinal clonidine combined with morphine, [D-Pen2, D-Pen5] enkephalin, or U50,488H

BACKGROUND

Visceral pain is an important component of many clinical pain states. The perispinal administration of drug combinations rather than a single agent may reduce side effects while maximizing analgesic effectiveness. The purpose of this study was to examine the nature of interactions between an alpha 2-adrenergic agonist (clonidine) and a mu-opioid agonist (morphine), a delta-opioid agonist ([D-Pen2, D-Pen5] enkephalin [DPDPE]), or a kappa-opioid agonist (U50,488H).

METHODS

Colorectal distension was used to elicit a nociceptive visceromotor response (contraction of abdominal musculature) in rats. The ability of intrathecally administered clonidine alone or in combination with morphine, DPDPE, or U50,488H to alter thresholds for the production of the visceromotor response was examined.

RESULTS

Clonidine produced dose-dependent reduction in threshold. U50,488H, at the doses tested, showed no synergistic interaction with clonidine.

CONCLUSIONS

Spinal combinations of alpha 2-adrenergic and mu- or delta- but not kappa-opioid agonists may be beneficial in the control of visceral pain.

[A survey of perioperative bronchospasm in 105 patients with reactive airway disease]

We investigated the relationship between the intra- and postoperative incidence of bronchospasm and the predisposing preoperative factors in 105 patients with reactive airway disease. (1) The incidence of bronchospasm in intra- and postoperative period was not associated with age, sex, duration of bronchial asthma, severity of disease, duration of the anesthesia and operation, or with FEV1.0%. (2) The incidence of intraoperative bronchospasm was high with general anesthesia using endotracheal intubation (8.9%), but low with general anesthesia using mask and regional anesthesia (0% and 2.2%, respectively). (3) The incidence of postoperative bronchospasm was about 20% with both general and regional anesthesia. However, the incidence of postoperative bronchospasm was higher in thoracic and abdominal surgeries than in other surgeries (39.5%:10.4%). (4) The incidences of intra- and postoperative bronchospasm increased in proportion to the proximity of the latest asthmatic attack to the operative date. (5) Prophylactic preoperative inhalation of bronchodilators was effective in the prevention of intraoperative bronchospasm, but some patients developed postoperative wheezing within a few days after the cessation of postoperative inhalation.

High-dose acyclovir and intravenous immune globulin reduce the incidence of CMV disease after liver transplantation

We attempted to prevent cytomegalovirus (CMV) disease in liver transplant (LTx) recipients by means of a combined prophylaxis regimen consisting of high-dose acyclovir (HDA) and immune globulin (IVIG). In 259 consecutive patients, HDA was given for 3 months post-LTx; recipients seronegative for CMV also received IVIG. The previous 94 patients comprised our control group; in this group, low dose acyclovir was given to prevent herpes, and prophylaxis of CMV consisted of IVIG given only to seronegative recipients of seropositive donors. The overall incidence of CMV disease was lower in the HDA group (10.8%) than in the control group (27.6%); (P < 0.001). The CMV disease rate associated with primary exposure was 26.3% in the HDA group and 83.3% in the control group (P < 0.001). The incidence of CMV disease occurring after acute rejection was 9.5% in HDA patients and 24.6% in controls (P < 0.005) The HDA protocol was associated with a trend toward a lower incidence of CMV in patients requiring OKT3 therapy (16.7% vs 29%). High-dose acyclovir/IVIG thus reduces the incidence of CMV disease in seronegative recipients after LTx and lowers the risk of CMV disease associated with therapy for rejection.

Severe or multiple rejection episodes are associated with early recurrence of hepatitis C after orthotopic liver transplantation

Recurrent hepatitis C causes significant morbidity after liver transplantation. Because immunosuppression is associated with enhanced viral replication, we postulated that clinical recurrence of the disease may be associated with augmented immunosuppression for rejection. In 96 patients with hepatitis C who received liver transplants, we recorded the interval from transplantation to recurrence, the episodes of steroid-resistant rejection (SRR) requiring OKT3, the number of rejection episodes, and the use of OKT3 induction. Recurrence was diagnosed based on elevated transaminases and characteristic histology. Hepatitis C recurred in 43 of 96 patients. Fifteen of 21 patients (71.4%) who previously had SRR had recurrence, versus 28 of 75 patients (37.3%) who either had no SRR (72 patients) or had it after recurrence was diagnosed (3 patients) (P < .01). Mean time to recurrence was 127 +/- 31 days in the 15 patients who had had SRR versus 246 +/- 42 days in the other 28 patients (P = .02). Recurrence and number of rejection episodes were clearly associated: 6 of 33 patients (18.2%) with no rejection had recurrence (P < .05), versus 11 of 26 patients (42.3%) with one rejection episode (P < .05) and 26 of 37 (70.2%) with more than 1 episode (P < .05). OKT3 induction was used in 15 patients; 9 of 15 patients had recurrence (ns) at 337 +/- 95 days. Of 72 patients who initially received triple immunosuppression, 30 patients had recurrence at 186 +/- 25 days (P = .05). Nine patients received primary FK506; 4 had recurrence at 68 +/- 14 days.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of ONO-1078, a peptide leukotriene antagonist, on endotoxin-induced acute lung injury

The role of lipoxygenase metabolites in the pathogenesis of endotoxin (LPS)-induced lung injury remains to be clarified. We investigated the contribution of peptide leukotrienes to LPS-induced acute lung injury using a potent antagonist, ONO-1078 (ONO). Experimental groups consisted of a saline group (n = 10), an LPS group (n = 9) injected intravenously with 2 mg E. coli LPS, an ONO group (n = 8) receiving 30 mg/kg of intraperitoneal ONO, and an LPS+ONO group (n = 6) receiving 30 mg/kg of ONO intraperitoneally 10 min before the LPS injection. The [125I]albumin lung plasma ratio, which is a parameter of acute lung injury, was significantly increased (p < 0.01) in the LPS group compared with the saline, ONO, and LPS+ONO groups. The [125I]albumin BAL fluid plasma ratio was also increased (p < 0.01) in the LPS group compared with the other groups. ONO pretreatment attenuated the LPS-induced increases in neutrophil counts in the BAL fluid. In vitro studies showed that ONO suppresses the neutrophil chemotaxis induced by LTB4, zymosan-activated serum, and FMLP. We conclude that (1) ONO-1078 attenuates LPS-induced acute lung injury; and (2) this effect appears mainly a result of its potent antagonistic actions against peptide leukotrienes and also, in part, the suppression of neutrophil chemotaxis.

Beneficial effect of thromboxane A2 synthetase inhibitor on cold-stored rat liver

Prostanoids such as prostacyclin and thromboxane A2 have recently been suggested to play important roles in cold ischemia/reperfusion injury. The purpose of this study was to investigate the effect of thromboxane A2 synthetase inhibitor (OKY-046) on cold-stored livers of the rat using an ex vivo perfusion system. Addition of OKY-046 to preservation solution and the perfusate of livers stored cold (4 degrees C) in lactated Ringer's solution resulted in significantly lower glutamic pyruvic transaminase release (3.01 +/- 0.86 IU/g liver vs. 1.79 +/- 1.08 IU/g liver at 120 min after perfusion; P < 0.05), reduced perfusate ammonia levels (8.51 +/- 2.51 micrograms/dl/g liver vs. 3.62 +/- 1.71 micrograms/dl/g liver at 60 min; P < 0.05 and thereafter), lower perfusate taurocholate levels (0.63 +/- 0.10 vs. 0.18 +/- 0.05 at 15 min; P < 0.01 and thereafter), perfusate hyaluronic acid clearance (0.934 +/- 0.132 vs. 0.76 +/- 0.127 at 30 min; P < 0.05 and thereafter), and a reduced number of trypan blue-positive sinusoidal lining cells (50.1 +/- 9.9%; vs. 17.4 +/- 7.0%; P < 0.01). Histologically, the liver preserved for 6 hr in simple cold lactated Ringer's solution exhibited interstitial edema, various degrees of hepatocyte swelling, and sinusoidal stenosis, as well as dilatation, while the livers treated with OKY-046 demonstrated much less hepatocyte swelling, and change in sinusoidal width was nearly absent. We conclude that OKY-046 reduces post-preservation reoxygenation injury by protecting sinusoidal endothelial cells and hepatocytes.

[An adult case of basal encephalomeningocele with recurrent meningitis]

A 35-year-old man developed meningitis for the first time at the age of 23. Thereafter, he repeatedly suffered from meningitis for six times before he was admitted to our clinic. Each meningitis was preceded by upper respiratory infection. Chronic infection in the head and neck, fracture of the skull base, liquorrhea, Mollaret meningitis, and acquired immunodeficiency were all ruled out. Nasal fiberscope examination revealed a palpating white tumor in the left olfactory cleavage. Coronal CT scanning demonstrated encephalomeningocele at the left ethmoidal cavity. The encephalomeningocele was surgically repaired and the patient has been free from further meningitis. The causal relationship between the encephalomeningocele and recurrent meningitis was discussed.

Serum hyaluronic acid for the assessment of graft viability in porcine liver transplantation

For the assessment of graft viability, serum hyaluronic acid (HA) levels during porcine orthotopic liver transplantation were measured in two groups: group 1 (viable: n = 5) in which allografts were transplanted following a minimal cold (4 degrees C) preservation, and group 2 (nonviable: n = 4) in which allografts were transplanted after cold static storage (4 degrees C) for 24 h in University of Wisconsin solution. The changes in the HA levels reached a significant difference between the two groups at 30 min after reperfusion (P < 0.02). In group 1, all animals survived for over 4 days, while all animals in group 2 died within 24 h. The serum HA also demonstrated a significant correlation with prothrombin time, beta-glucuronidase, and aspartate aminotransferase at 120 min after reperfusion. These results suggest that the measurement of serum HA is a potentially effective index for evaluating hepatic allograft viability.

Obviation of prereperfusion rinsing and decrease in preservation/reperfusion injury in liver transplantation by portal blood flushing

Liver allografts are traditionally rinsed with cold lactated Ringer's (LR) prereperfusion to clear K(+)-rich preservation solution from the hepatic vasculature. LR has been shown, however, to be injurious to the graft. By restoring portal blood flow without rinsing and discarding the initial blood traversing the liver (PB flush), we sought to eliminate rinsing without inducing hyperkalemia. Between August 1988 and December 1992, 481 OLTx were performed in 412 pts. Four rinsing methods were used sequentially: group 1 (157 pts)--low-flow-rate cold LR rinse (500 ml, 100 ml/min via standard i.v. tubing at 100 cm H2O [LFLR]) during lower caval anastomosis; Group 2 (120 pts)--LFLR as in group 1, at reperfusion, 500 ml PB flush via IVC catheter; group 3 (66 pts)--high-flow-rate LR rinse (500 ml, 1 L/min using large-bore tubing with 100 cm H2O rinsing pressure [HFLR]), PB flush as in group 2; Group 4 (62 pts)--no LR rinse; PB flush as in groups 2 and 3. Poor early graft function (PEGF) was defined as peak ALT or AST > 2500 U or PT > 16 sec (on POD 2); PEGF causing re-OLTx or death within 14 days was called primary nonfunction (PNF). Group 1 and Group 3 had high PEGF rates. Group 4 had significantly less PEGF than Group 1, with a trend toward a significant difference from Group 3. In Group 1, 3 pts. had intraoperative hyperkalemic cardiac arrest; this did not occur when PB flush was performed. PB flush without prior rinsing optimizes graft function without risk of hyperkalemia. LR rinse, alone or followed by PB flush, is unnecessary and may be deleterious.

Prolonged preservation in University of Wisconsin solution associated with hepatic artery thrombosis after orthotopic liver transplantation

Hepatic artery thrombosis (HAT) after liver transplantation (LTx) usually mandates retransplantation. Prolonged preservation with Eurocollins solution has been associated with HAT. We reviewed our experience with 359 LTx patients to identify risk factors for HAT. All grafts were preserved in University of Wisconsin solution. HAT developed in 12 patients (3%) within 50 days. Seven patients were asymptomatic; four presented with biliary sepsis and 1 with poor graft function. Two patients had suffered acute rejection; another 2 had severe preservation injury. Technical problems accounted for 4 cases; in the remaining 8, no etiology was found. Diagnosis was at a mean 14.7 days after LTx. One patient maintains normal graft function 3 years after LTx without intervention. Eight underwent re-LTx, 3 of whom died. Routine surveillance via duplex enabled early diagnosis and revascularization in 3 patients; in all 3, no biliary complications occurred between 6 and 20 months. Overall graft and patient survival after HAT were 33.3% and 75%, respectively. Cold ischemic time (CIT) averaged 813 min in patients with HAT and 669 min in those without HAT (P < .05). HAT occurred in 7/165 patients with CIT > 12 hr, and in 3/234 patients with CIT < 12 hr (P = 0.0699). By avoiding CIT > 12 hr, we have recently avoided HAT in 78 consecutive patients. We conclude that CIT > 12 hr may increase the risk of HAT. When HAT is diagnosed before biliary sepsis develops, flow can often be restored and retransplantation averted.

Extracorporeal hepatic resection for previously unresectable neoplasms

BACKGROUND

Some hepatic tumors are judged inoperable solely for anatomic reasons, such as the proximity of the tumor with the major vasculature. This is because of high mortality and morbidity rates, as well as a compromised surgical margin.

METHODS

We successfully performed extracorporeal hepatic resections in two patients who were judged to have inoperable tumors by conventional means.

RESULTS

Both patients had an uneventful postoperative course, and although one patient had intrahepatic recurrence 6 months after operation, the other patient shows no recurrence 10 months later.

CONCLUSIONS

Advances in techniques for liver transplantation and organ preservation now allow resection of anatomically unresectable hepatic tumors that were deemed inoperable in the past.

Norepinephrine prolongs tetracaine spinal anesthesia in surgical patients: a preliminary study

We conducted a double-blinded examination of the effects of norepinephrine as a vasoconstrictor on the onset and duration of tetracaine spinal anesthesia in 80 surgical patients. The patients were randomly allocated to four groups (n = 20 in each group). Each patient received 10 mg of tetracaine in a volume of 2.0 mL which contained either 0 micrograms/mL, 5 micrograms/mL, 10 micrograms/mL, or 15 micrograms/mL of norepinephrine. The onset of spinal anesthesia was determined by the time to reach Th-10 level as well as by the time required to obtain the highest level of sensory analgesia. The time for two-segment regression and full-motor recovery were defined as the duration of spinal anesthesia. The time to reach Th-10, the highest analgesia level, and the time to obtain the highest analgesia level did not differ among the groups. Two-segment regression was prolonged significantly by 175%, 103%, and 106% as compared with the plain tetracaine group, in 5 micrograms/mL, 10 micrograms/mL, and 15 micrograms/mL of norepinephrine groups, respectively. Motor recovery also was extended significantly by 111%, 152%, and 121% as compared with the plain tetracaine group, in 5 micrograms/mL, 10 micrograms/mL, and 15 micrograms/mL of norepinephrine groups, respectively. There were no differences in the changes of arterial blood pressure and heart rate associated with the addition of norepinephrine among the groups. We conclude that norepinephrine provides a clinically meaningful prolongation of the duration of tetracaine spinal anesthesia.

Prediction of hepatic graft viability before reperfusion: an analysis of effluent from porcine allografts

Rapid and reliable assessment of hepatic graft viability is important for successful orthotopic liver transplantation (OLTx). OLTx was performed in 11 pairs of pigs via a venovenous bypass. Six of these grafts were transplanted immediately (group A), while the other five were preserved in University of Wisconsin (UW) solution for 24 h and then transplanted (group B). All grafts were flushed with 300 ml of chilled (4 degrees C) Ringer's lactate solution before reperfusion of the graft, when 20 ml of effluent from the graft was collected and the concentrations of ammonia, lactic acid, GOT, and LDH were measured. Four of the six pigs in group A survived longer than 3 days, while the other two pigs died of causes other than graft dysfunction. All five pigs in group B died either of hemoperitoneum or hemodynamic instability due to liver failure. The histology of postperfusion biopsies in group A showed minimal pathological changes, while the grafts in group B revealed moderate to severe ischemic injuries. Ammonia and lactic acid in the effluent of group B were significantly higher than those of group A (1511 +/- 216 vs 417 +/- 333 micrograms/dl and 114.1 +/- 12.2 vs 91.4 +/- 12.2 mg/dl, respectively; P < 0.05 in both cases). Before reperfusion, the rate of total adenine nucleotides in all of the substances in the graft, which were measured using high performance liquid chromatography (HPLC), inversely correlated with the ammonia levels in the effluent. We conclude that an analysis of the effluent, (i.e. the levels of ammonia and lactic acid), flushed from a hepatic graft before reperfusion could serve as a predictor of hepatic graft viability.

ONO-4057, a novel, orally active leukotriene B4 antagonist: effects on LTB4-induced neutrophil functions

ONO-4057(5-[2-(2-Carboxyethyl)-3-[6-(4-methoxyphenyl)-5E- hexenyl]oxyphenoxy]valeric acid), an orally active leukotriene B4(LTB4) antagonist, displaced the binding of [3H] LTB4 to the LTB4 receptor in human neutrophil (Ki = 3.7 +/- 0.9 nM). ONO-4057 inhibited the LTB4-induced rise in cytosolic free calcium (the concentration causing 50% inhibition (IC50) = 0.7 +/- 0.3 microM) and inhibited human neutrophil aggregation, chemotaxis or degranulation induced by LTB4 (IC50 = 3.0 +/- 0.1, 0.9 +/- 0.1 and 1.6 +/- 0.1 microM) without showing any agonist activity at concentration up to 30 microM. ONO-4057 did not inhibit fMLP or C5a-induced neutrophil activation at concentrations up to 30 microM. In the in vivo study, ONO-4057 given orally, prevented LTB4-induced transient neutropenia or intradermal neutrophil migration in guinea pig (the dose causing 50% efficacy (ED50) = 25.6mg/kg or 5.3mg/kg). Furthermore, ONO-4057 given topically, suppressed phorbol-12-myristate-13-acetate (PMA)-induced neutrophil infiltration in guinea pig ear (the effective dose = 1 mg/ear). These results indicate that ONO-4057 is a selective and orally active LTB4 antagonist and may be a potential candidate for the treatment of various inflammatory diseases.

Ischemic injury in liver transplantation: difference in injury sites between warm and cold ischemia in rats

Using liver allografts with warm or cold ischemia, we evaluated functional and morphological alterations in hepatocytes, sinusoidal endothelial cells and Kupffer cells in a rat transplantation model. All recipients of allografts with either 4 hr of cold or 30 min of warm ischemia lived more than 22 days and were judged viable. On the other hand, all recipients of grafts with 6 hr of cold or 60 min of warm ischemia died within 2 days and were therefore judged to be nonviable. With these viable and nonviable allograft models, hepatocyte function was evaluated by the bile output and serum glutamic-oxaloacetic transaminase, serum glutamic-pyruvic transaminase and serum lactate dehydrogenase levels; endothelial cell function was judged by the serum hyaluronic acid level, and Kupffer cell function was measured by an intravenous colloidal carbon clearance test. Hepatocyte injury was the prominent feature in warm ischemic grafts, especially in the nonviable ones. On the other hand, serum hyaluronic acid values were significantly higher in the nonviable cold ischemic group, compared with the viable counterpart, suggesting that the functional depression of endothelial cells was predominant in cold, nonviable livers. Histological examinations coincided with the above findings. The phagocytic activity of Kupffer cells was depressed by warm or cold ischemia, whereas the number of Kupffer cells was reduced in the warm ischemia group. We conclude that in liver allografts the main site of injury in warm ischemia is the hepatocytes and suggest that cold ischemia is associated with endothelial cell damage.

[Clinical study of patients with hepatic disease at a city hospital in Japan--consideration on indications for liver transplantation]

One-hundred and ninety-one patients with liver diseases who were admitted to National Fukuoka Central hospital during a 3 years period between January 1, 1984 and December 31, 1986 were studied to assess the indications for liver transplantation with the use of a criteria by Dr. Van Thiel et al. The patients were divided into 2 groups; I--indication and II--no indication. Then group I was divided into 3 groups; A--no contraindication, B--relative-contraindication and C--contraindication. Of the 131 patients, group A and B which had the indication of liver transplantation without contraindication were 17%. Deaths by April 30, 1990 were as follows; I 62% (A 36%, B 86%, C 100%) and II 12%. Ten out of 13 deaths in Group I were all due to hepatic failure, while only 3 out of 8 deaths in Group II were due to hepatic failure. Of the other 60 patients with malignancy, 57 were hepatocellular carcinomas, and the other 3 were 2 metastatic hepatic cancers and cholangioma. Among the patients with hepatocellular carcinoma, 24 out of 46 died of cancer, while the other 19 patients died of hepatic failure. The criteria of the indication of liver transplantation seems acceptable for the evaluation of Japanese patients with non-malignant hepatic diseases. As to patients with hepatocellular carcinoma, a new and separate criteria is in need to evaluate them for liver transplantation.

Effects of famotidine and cimetidine on plasma levels of epidurally administered lignocaine

The effects of two H2-receptor antagonists, famotidine and cimetidine, on the plasma levels of epidurally administered lignocaine were studied. Group A (n = 20) received famotidine 20 mg orally the night before surgery and 20 mg intramuscularly 60 minutes before induction of anaesthesia. Group B (n = 15) received cimetidine 200 mg orally the night before the surgery and 400 mg orally 60 minutes before the anaesthetic induction. Group C (n = 20) received neither famotidine nor cimetidine and served as controls. Twelve millilitres of 2.0% lignocaine with adrenaline 1:200,000 was injected into the epidural space in all patients, after the establishment of general anaesthesia with nitrous oxide, oxygen, and enflurane (0.3-0.5%). The patients who received cimetidine showed significantly higher plasma concentrations of lignocaine compared with either group A or group C at all investigation times (p less than 0.01). The mean peak plasma concentrations were 2.4 (SEM 0.1), 3.2 (SEM 0.2) and 2.3 (SEM 0.1) micrograms/ml in group A, B, and C, respectively. This study suggests that famotidine is preferable to cimetidine for control of gastric acidity before the use of lignocaine as the epidural anaesthetic.

High-renin malignant hypertension secondary to an aldosterone-producing adenoma

Malignant hypertension and high plasma renin activity was found in a 39-year-old woman with an aldosterone-producing adenoma. Only 3 similar cases have been previously reported, and all patients died before or after identification of the adenoma. The present paper documents the first reported case of a successfully managed high-renin malignant hypertension secondary to an aldosterone-producing adenoma. Regardless of its sporadic occurrence and common presence with low plasma renin activity, primary aldosteronism should be considered as a possible underlying cause of high-renin malignant hypertension.

[Intrathecal clonidine--how does it work in spinal fentanyl analgesia in rats?]

The effects of intrathecal clonidine on spinal fentanyl analgesia were studied by the hot-plate test (52.0 degrees C) in rats. Clonidine (5 micrograms) and/or fentanyl (5 micrograms) were administered alone or combined in volume of 10 microliters through a chronically-implanted polyethylene catheter (PE-10) whose tip was near the lumbar enlargement of the spinal cord. Injections were done repeatedly every two or three days to determine the time course of thermal analgesia. Results were as follows; 1) Intrathecal clonidine (n = 5) produced no thermal analgesia. 2) Intrathecal fentanyl (n = 10) produced a profound thermal analgesia which was attenuated markedly by the repeated injections in six rats before the 9th injection. 3) Two out of six fentanyl tolerated rats responded with remarkable increases in thermal thresholds following the intrathecal clonidine with fentanyl. 4) Rats which were administered with both clonidine and fentanyl from the 1st injection (n = 9) responded with a extended prolongation of the escape latency, compared with the rats which received fentanyl only. In this group, the tolerance developed in only three animals by the 9th injection. In conclusion, combined intrathecal administration of clonidine with fentanyl potentiated the analgesic effect of fentanyl and then definitely suppressed the tolerance formation even if a small dose of clonidine which produces no analgesic effect was used. These results suggest that intrathecal or epidural administration of clonidine with narcotics might be useful in managing intractable pain.

The effects of alpha-tocopherol on site-specific lipid peroxidation induced by iron in charged micelles

alpha-Tocopherol inhibited H2O2-Fe2+-induced lipid peroxidation of linoleic acid (LA) by scavenging OH radicals in tetradecyltrimethylammonium bromide (TTAB) micelles. The inhibiting ability of alpha-tocopherol was much greater than that of OH-radical scavengers mannitol and t-butanol. In contrast, alpha-tocopherol enhanced linoleic acid hydroperoxide (LOOH)-Fe2+-induced lipid peroxidation through regeneration of Fe2+ in sodium dodecyl sulfate (SDS) micelles containing LA. alpha-Tocopherol was oxidized by Fenton's reagent (FeSO4 + H2O2) at a higher rate in SDS micelles than in TTAB micelles. The likely oxidants were OH radicals in the former and Fe3+ in the latter. Both reagents formed in the Fenton reaction. Ferrous ion catalyzed in a dose-dependent manner the decomposition of LOOH and conjugated diene compounds in SDS but not in TTAB micelles. alpha-Tocopherol and Fe3+ individually had no effect on the decomposition of LOOH, but together were quite effective. The rate of the decomposition was a function of the concentration of alpha-tocopherol. The mechanism of "site-specific" antioxidant action of alpha-tocopherol in charged micelles is discussed.

Site-specific induction of lipid peroxidation by iron in charged micelles

Generation of hydroxyl radicals by the Fenton reaction resulted in lipid peroxidation of linoleic acid (LA) (H2O2-Fe2+-induced lipid peroxidation) in positively charged tetradecyltrimethylammonium bromide (TTAB) micelles, but not in negatively charged sodium dodecyl sulfate (SDS) micelles. However, more OH radicals formed via the Fenton reaction were trapped by N-t-butyl-alpha-phenylnitrone (PBN) in SDS micelles than in TTAB micelles. When detergent-dispersed LA was contaminated with linoleic acid hydroperoxide (LOOH), lipid peroxidation was catalyzed by Fe2+ via reductive cleavage of LOOH (LOOH-Fe2+-induced lipid peroxidation), and Fe2+ was oxidized simultaneously in SDS micelles, even when H2O2 was not present. In contrast, LOOH-Fe2+-induced lipid peroxidation and simultaneous oxidation of Fe2+ were not observed in TTAB micelles. An ESR spectrum presumed to be due to an alkoxy radical trapped by PBN was also detected in SDS micelles, but not in TTAB micelles in the LOOH-Fe2+-induced lipid peroxidation system. The results are discussed in the light of the localization of iron, the unsaturated bonding moiety of LA, the OOH-group of LOOH, and the trapping site of PBN in different charged micelles.

Fluorescent pigments by covalent binding of lipid peroxidation by-products to protein and amino acids

The fluorescent products formed on reaction of 12-oxo-cis-9-octadecenoic acid (12-keto-oleic acid) with about 20 different amino acids, polylysine and bovine serum albumin (BSA) were studied. Besides glycine, only the basic amino acids histidine, lysine and arginine gave products with strong fluorescence. N-Acetylation of amino acids greatly reduced the fluorescence of their reaction products. The formation of fluorescent products was inhibited strongly by SH-amino acids such as N-acetyl-cysteine and glutathione. Polyacrylamide gel electrophoresis showed that BSA treated with 12-keto-oleic acid was more acidic than untreated or ricinoleic acid-treated BSA, indicating that basic amino acid residues in BSA were modified by reaction with the keto fatty acid. None of the structural analogs of 12-keto-oleic acid tested--12-oxo-trans-10-octadecenoic acid, 12-oxo-octadecanoic acid, 12-hydroxy-cis-9-octadecenoic acid (ricinoleic acid), cis-9-octadecenoic acid (oleic acid) and linoleic acid--reacted with glycine to give a fluorescent product. The fluorescent products formed on reaction of 12-keto-oleic acid methyl ester with benzyl amine and glycine methyl ester were shown to be 8-(N-substituted-4,5-dihydro-4-oxo-5-hexyl-5-hydroxy-2-pyrrolyl) octanoic acid methyl esters. The fluorescence properties of these compounds were attributed to the chromophobic system NC = CC = O which contains 6 pi electrons. This investigation contributes to insight of the mechanism of formation of fluorescent pigments, probably by a similar reaction of other compounds of the beta, gamma-unsaturated carbonyl type.