The effect of lansoprazole treatment on the healing and relapse of peptic ulcer and serum levels of IgG anti-Helicobacter pylori antibody

In the present study, the effects of short-term treatment with lansoprazole on healing and recurrence of peptic ulcer were investigated. Complete healing (change to the S2 stage) after 3 or 4 weeks of treatment with lansoprazole was observed in 9.9% of gastric ulcers and 38.3% of duodenal ulcers. Complete healing was observed after 3 or 4 weeks of treatment with lansoprazole in gastric ulcers and was significantly related to the serum titer of IgG anti-Helicobacter pylori antibodies. This was not the case in duodenal ulcers. Complete healing after 6 or 8 weeks of treatment with lansoprazole was not dependent on serum levels of IgG anti-H. pylori antibodies. Short-term treatment by lansoprazole did not affect serum levels of IgG anti-H. pylori antibodies immediately after the end of lansoprazole treatment, but significantly reduced serum levels of IgG anti-H. pylori antibodies were found 9 months after treatment.

Inhibition by somatostatin of amylase secretion induced by calcium and cyclic AMP in rat pancreatic acini

It has recently been shown that somatostatin inhibits amylase secretion from isolated pancreatic acini by reducing cyclic AMP (cAMP) production [Matsushita, Okabayashi, Hasegawa, Koide, Kido, Okutani, Sugimoto and Kasuga (1993) Gastroenterology 104, 1146-1152]. To date, however, little is known as to the other mechanism(s) by which somatostatin inhibits amylase secretion in exocrine pancreas. To investigate the action of somatostatin independent of cAMP generation, we examined the effect of somatostatin in isolated rat pancreatic acini stimulated by 1 microM calcium ionophore A23187 and 1 mM 8-bromo-cyclic AMP (8Br-cAMP). Somatostatin inhibited amylase secretion evoked by a combination of A23187 and 8Br-cAMP in a dose-dependent manner. The maximum inhibition was obtained by 10(-7) M somatostatin, and at this concentration somatostatin inhibited the effect of A23187 and 8Br-cAMP by approximately 30%. In electrically permeabilized acini, an elevation of free calcium concentration resulted in an increase in amylase secretion and cAMP enhanced the secretion evoked by calcium. cAMP shifted the dose-response curve for calcium-induced secretion leftwards and elevated the peak value of secretion. Somatostatin inhibited the effect of cAMP on calcium-induced amylase secretion by shifting the dose-response curve to the right. To determine the involvement of a G-protein(s), we examined the effect of somatostatin in acini pretreated with pertussis toxin. Pretreatment of acini with pertussis toxin completely blocked somatostatin-inhibition of amylase-secretion evoked by A23187 and 8Br-cAMP. These results indicate that somatostatin decreases amylase secretion induced by cAMP and calcium by reducing the calcium sensitivity of exocytosis. A pertussis toxin-sensitive G-protein is also involved in this step.

Activin A: negative regulator of amylase secretion and cell proliferation in rat pancreatic acinar AR42J cells

Activin A, a member of the transforming growth factor-beta supergene family, exists in secretory granules of non-B-cells of rat pancreatic islet (H. Yasuda, K. Inoue, H. Shibata, T. Takeuchi, Y. Eto, Y. Hasegawa, N. Sekine, Y. Totsuka, T. Mine, E. Ogata, and I. Kojima. Endocrinology 133: 624-630, 1993). Because functions of exocrine pancreas are influenced by hormones in pancreatic islet, it is possible that activin A affects the function of pancreatic acinar cells. To examine this possibility, we studied the effects of activin A on amylase secretion and DNA synthesis in AR42J cells. In these cells, dexamethasone (Dx) induces increases in secretory organelles and secretion of amylase (C. D. Logsdon, J. Moessner, J. A. Williams, and I. D. Goldfine. J. Cell Biol. 100: 1200-1208 1985). Activin A did not change the rate of amylase release by itself nor affect the cholecystokinin-stimulated amylase release from Dx-treated differentiated AR42J cells. However, when activin A was added together with Dx, activin A inhibited Dx-induced increase in amylase content in a dose-dependent manner. In the presence of 1 nM activin A, the effect of Dx was abolished. In the absence of Dx, amylase content of the cells was also reduced by activin A in a dose-dependent manner. The maximum inhibitory effect was obtained by 10 nM activin A, and at this concentration amylase content became undetectable. In addition, activin A potently inhibited DNA synthesis as assessed by [3H]thymidine incorporation.(ABSTRACT TRUNCATED AT 250 WORDS)

Stimulation of follistatin production by epidermal growth factor in cultured rat hepatocytes

Production of follistatin in cultured rat hepatocytes was studied by measuring follistatin release with a protein-binding assay using [125I]activin A. Follistatin was detected in conditioned medium of cultured hepatocytes. Ligand blotting using [125I]activin revealed that follistatin released into the medium consisted of two different forms with molecular weight of approximately 40 K-Da. Epidermal growth factor (EGF) elicited dose-dependent increases in DNA synthesis and follistatin release. Dose-response relationship for EGF-induced follistatin release correlated well with that for EGF-induced DNA synthesis. In EGF-stimulated cells, a marked increase in DNA synthesis occurred after 48 hrs. Similarly, follistatin release was markedly augmented after 48 hrs. Amount of cell-bound follistatin was not changed by the treatment with EGF. These results indicate that cultured hepatocytes synthesize and release follistatin. The activin-follistatin system operates in cultured rat hepatocytes and may modulate DNA synthesis by altering the action of activin A.

Studies on the effect of parathyroid hormone (1-84) on glucose output in the liver: comparison of effects in isolated hepatocytes and in perfused liver

This study was conducted to determine the action of parathyroid hormone (1-84) (PTH(1-84)) on glucose output both in perfused liver and in isolated hepatocytes. In isolated rat hepatocytes, PTH(1-84) stimulated glucose output in a concentration-dependent manner. The action was detected at 10(-11) M and, at 10(-9) M, PTH produced its maximal effect. The magnitude of the maximal effect of PTH(1-84) was about 65% of that of phenylephrine. In contrast, PTH(1-84) had no effect on glucose output in perfused rat liver. Concentration of PTH(1-84) in effluent of perfused liver was less than that in the inflow. However, when the effluent obtained from liver perfused with 10 nM PTH(1-84) was added to isolated hepatocytes, a considerable amount of glucose was released, which was reversed by PTH(7-34), a competitive inhibitor of PTH receptor. These results indicate that PTH(1-84) increases glucose output in isolated hepatocytes but not in intact liver. It is suggested that the action of PTH(1-84) is blocked in intact liver by a yet unknown mechanism.

Healing of chronic gastric ulcer depends on gastric mucosal prostaglandin synthesis

In the present study, the role of endogenous prostanoid synthesis in gastric mucosa in the healing of chronic gastric ulcers was investigated. Nineteen patients were divided into two groups in accordance with healing state after one month of treatment with cimetidine only: "healed group" and "unhealed group". Biopsy specimens taken from the mucosa around the ulceration (damaged gastric mucosa) and at a distance from the ulceration (normal gastric mucosa) at endoscopy prior to treatment were homogenized, and the mucosal prostanoid synthesis was determined using [14C]arachidonic acid. The mean value of prostaglandin E2 synthesis in the normal gastric mucosa of the healed group was 60% higher than in that of the unhealed group, but the difference was not significant. However, prostaglandin E2 synthesis in the damaged gastric mucosa of the healed group was 117% higher than in that of the unhealed group. The same tendency was observed for prostaglandin D2 and 6-keto prostaglandin F1 alpha synthesis as for prostaglandin E2. In our study it was demonstrated that there is a good correlation of prostaglandin synthesis in the damaged mucosa with healing of chronic gastric ulceration. Furthermore, our study indicated that prostaglandin synthesis, especially in damaged mucosa, might be important in the healing of gastric ulceration.

Pharmacological properties of the new stable prostacyclin analogue 3-Oxa-methano-prostaglandin I

The pharmacological characteristics of the 3-oxamethano-prostaglandin I1 compound (+)-methyl [2-[(2R,3aS,4R,5R,6aS)-octahydro-5-hydroxy-4- [(E)-(3S,5S)-3-hydroxy-5-methyl-1-nonenyl]-2-pentalenyl]etho xy] acetate (SM-10902, CAS 139403-31-9), a novel stable analogue of prostacyclin and its free acid, SM-10906, were studied. SM-10902 was rapidly deesterified to its free acid in rabbit and human serum. SM-10902 and SM-10906 exhibited antiplatelet potency against ADP-induced aggregation in rabbit and human platelets. In the presence of diisopropyl fluorophosphate, an esterase inhibitor, the antiplatelet activity of SM-10902 was markedly reduced, to much less than that of SM-10906. SM-10906 inhibited platelet aggregation induced by various inducers in several species and enhanced the cyclic AMP (cAMP) level in human platelets. These activities were nearly equal to those of prostaglandin (PG) E1 and less than those of PGI2. SM-10906 relaxed isolated rabbit mesenteric and bovine coronary arteries, and elevated the cAMP level in bovine coronary arteries. SM-10906 given intravenously exhibited a sustained reduction in blood pressure based on vasodilation in ganglion-blocked, angiotensin II-supported rats. SM-10902 applied to the guinea-pig auricles increased the skin temperature, but SM-10906 and PGI2 showed no such effect. In conclusion, SM-10902, which is considered to be a prodrug of SM-10906, was suggested to exert its anti-platelet and vasodilator activities through the increase of cAMP. Since SM-10902 penetrates well into the skin, it may be useful as an external preparation to improve peripheral circulatory insufficiency.

Pharmacokinetics of SM-10888 and its metabolites depending on their physicochemical properties

To investigate how the physicochemical properties and pharmacokinetics of SM-10888 are altered by metabolic reactions, physicochemical and pharmacokinetic parameters of its phase I and phase II metabolites were determined. The metabolic pathways of SM-10888 in rats include oxidation at the C1 position (via the hydroxylated metabolite M3 to the cyclic ketone M4) and glucuronidation of both SM-10888 and M3 (SMG and M3G). Partition coefficients between n-octanol/pH 7.4 buffer (logP*) were determined to be 2.23 for SM-10888, 1.59 for M3, 2.66 for M4, -1.37 for SMG, and -1.72 for M3G. The phase I metabolite M3 showed lower lipophilicity and serum protein binding at pH 7.4, and larger renal clearance (CLr) than SM-10888. In contrast, the further oxidized metabolite M4 demonstrated higher lipophilicity and protein binding and lower CLr than SM-10888 and M3. Among these nonconjugated forms, only the pKa value of M4 was found to be below 7.4 (6.2 for M4, 8.5 for SM-10888, and 8.0 for M3), indicating that M4 exists in a more lipophilic nonionized form at the physiological pH, whereas SM-10888 and M3 are present as ionized forms. The significant shift in pKa of M4 could be the result of a cooperative effect of the electron withdrawing carbonyl group and resonating structure allowing hydrogen bond formation between CO and NH2 group, and might explain its high lipophilicity and low CLr. Glucuronidation significantly increased hydrophilicity with CLr's in excess of the glomerular filtration rate, suggesting involvement of active transport.

Metabolism of a tetrahydroaminoacridine derivative (SM-10888) in rat: structural analysis of an N-glucuronide of SM-10888 and an O-glucuronide of hydroxylated SM-10888 by FAB-MS/MS

1. The metabolism of 9-amino-8-fluoro-1,2,3,4-tetrahydro-2,4-methanoacridine citrate (SM-10888), a cholinesterase inhibitor was studied in rat. 2. The phase I metabolite (designated M3) was isolated from urine and identified as 1-hydroxylated SM-10888 by 1H-n.m.r. and EI-MS. 3. Two glucuronides (designated SMG and M3G) were isolated from bile and urine and their structures examined by FAB-MS/MS and beta-glucuronidase hydrolysis. 4. FAB-mass spectra of SMG and M3G showed molecular ions ([M+H]+) at m/z 405 and 421, respectively. In their daughter spectra, fragment ions of aglycones (SM-10888 and M3), generated by the loss of glucuronic acid (176 amu) were observed. The daughter spectra of these aglycones were essentially similar to those of the corresponding synthetic standards. 5. SMG was hydrolysed non-enzymically at pH 5 as is often the case with N-glucuronides of arylamines. M3G could be hydrolysed by beta-glucuronidase but proved stable at pH 5. 6. From these results, SMG and M3G were concluded to be the N-glucuronide of SM-10888 and the O-glucuronide of M3, respectively.

Activin A: an autocrine inhibitor of initiation of DNA synthesis in rat hepatocytes

The present study was conducted to examine the effect of activin A on growth of rat hepatocytes. EGF induced a 10-fold increase in DNA synthesis as assessed by [3H]thymidine incorporation in cultured hepatocytes. When activin A was added together with EGF, DNA synthesis induced by EGF was markedly inhibited. Inhibition was detected at a concentration of 10(-10) M, and 5 x 10(-9) M activin A almost completely blocked EGF-mediated DNA synthesis. Similarly, activin A completely blocked DNA synthesis induced by hepatocyte growth factor/scatter factor. Activin A was capable of inhibiting EGF-mediated DNA synthesis, even when added 36 h after the addition of EGF. With the same time interval, TGF-beta also blocked EGF-induced DNA synthesis. Although both activin A and TGF-beta inhibited growth of hepatocytes in a similar manner, either activin A or TGF-beta did not compete with each other in their binding when assessed by competitive binding using an iodinated ligand. When hepatocytes were incubated with EGF, release of bioactivity of activin A into culture medium was detected after 48 h or later. Activity of activin A was released from parenchymal cells but not from nonparenchymal cells. mRNA for beta A subunit of activin was detected only slightly in unstimulated hepatocytes, but markedly increased at 48 h after the addition of EGF. To determine whether endogenously produced activin A affects DNA synthesis, we examined the effect of follistatin, an activin-binding protein that blocks the action of activin A. An addition of follistatin significantly enhanced EGF-induced DNA synthesis. Finally, in partial hepatectomized rat, expression of mRNA for beta A subunit in liver was markedly increased 24 h after the partial hepatectomy. These results indicate that activin A inhibits initiation of DNA synthesis in hepatocytes by acting on its own receptor and that activin A acts as an autocrine inhibitor of DNA synthesis in rat hepatocytes.

Activin A: an autocrine inhibitor of initiation of DNA synthesis in rat hepatocytes

The present study was conducted to examine the effect of activin A on growth of rat hepatocytes. EGF induced a 10-fold increase in DNA synthesis as assessed by [3H]thymidine incorporation in cultured hepatocytes. When activin A was added together with EGF, DNA synthesis induced by EGF was markedly inhibited. Inhibition was detected at a concentration of 10(-10) M, and 5 x 10(-9) M activin A almost completely blocked EGF-mediated DNA synthesis. Similarly, activin A completely blocked DNA synthesis induced by hepatocyte growth factor/scatter factor. Activin A was capable of inhibiting EGF-mediated DNA synthesis, even when added 36 h after the addition of EGF. With the same time interval, TGF-beta also blocked EGF-induced DNA synthesis. Although both activin A and TGF-beta inhibited growth of hepatocytes in a similar manner, either activin A or TGF-beta did not compete with each other in their binding when assessed by competitive binding using an iodinated ligand. When hepatocytes were incubated with EGF, release of bioactivity of activin A into culture medium was detected after 48 h or later. Activity of activin A was released from parenchymal cells but not from nonparenchymal cells. mRNA for beta A subunit of activin was detected only slightly in unstimulated hepatocytes, but markedly increased at 48 h after the addition of EGF. To determine whether endogenously produced activin A affects DNA synthesis, we examined the effect of follistatin, an activin-binding protein that blocks the action of activin A. An addition of follistatin significantly enhanced EGF-induced DNA synthesis. Finally, in partial hepatectomized rat, expression of mRNA for beta A subunit in liver was markedly increased 24 h after the partial hepatectomy. These results indicate that activin A inhibits initiation of DNA synthesis in hepatocytes by acting on its own receptor and that activin A acts as an autocrine inhibitor of DNA synthesis in rat hepatocytes.

Activin A increases intracellular free calcium concentrations in rat pancreatic islets

Activin A stimulated insulin secretion in rat pancreatic islets, an effect that was attenuated by reduction of extracellular Ca2+ and abolished by either nitrendipine or verapamil. Activin A increased intracellular the free Ca2+ concentration, [Ca2+]i in fura-2-loaded islets. Activin A-mediated elevation of [Ca2+]i was abolished by the reduction of extracellular Ca2+ or the addition of nifedipine. In addition, activin A did not increase [Ca2+]i in the presence of diazoxide, an opener of ATP-sensitive K+ channels. These results suggest that activin A increases insulin secretion by stimulating Ca2+ entry.

Existence of activin-A in A- and D-cells of rat pancreatic islet

Activin-A, a member of the transforming growth factor-beta supergene family, stimulates insulin secretion in rat pancreatic islets and causes glycogenolysis in isolated rat hepatocytes. These observations prompted us to determine whether activin-A existed in rat pancreas by using an immunocytochemical method. Cells in pancreatic islets were stained by antibody against activin-A, whereas no immunoreactivity was observed in exocrine pancreas. Cells localized in the mantle of the islets were densely stained by the antibody. Immunoelectron microscopic study showed that activin-A existed in secretory granules in both A- and D-cells. Furthermore, studies using a double labeling method revealed that activin-A coexisted with glucagon in secretory granules in A-cells and with somatostatin in D-cells. Antibody against inhibin-A weakly stained cells in both the core and mantle of the islets only when the rat was pretreated with colchicine. Subtypes of activin subunit in islets were identified to be beta A by a reverse transcription-polymerase chain reaction method. In addition, mRNA for inhibin alpha-subunit was expressed in islets. However, mRNA for these inhibin subunits was not detected in exocrine pancreas. To further examine the action of activin-A on insulin secretion, we examined the effect of activin-A in a flow-through perifusion system. Activin-A induced a biphasic insulin secretory response in the presence of 2.8 mM glucose, and a low concentration of activin-A, which does not stimulate insulin secretion by itself, markedly enhanced glucose-mediated insulin secretion at concentrations above 2.8 mM glucose. Inhibin-A did not affect insulin secretion. These results suggest the existence of activin-A in A- and D-cells of rat pancreatic islets and raise the possibility that activin-A acts as a physiological regulator of carbohydrate metabolism.

Role of calcium fluxes in the action of glucagon on glucose metabolism in rat hepatocytes

The aim of the present study was to assess the role of calcium fluxes in the action of glucagon on glycogenolysis and gluconeogenesis in isolated rat hepatocytes. Calcium influx was blocked by two ways: by use of the compound tetramethrin and by reduction of extracellular calcium to 1 microM. The minimal concentration of tetramethrin that inhibited glucagon-mediated calcium entry was 7.5 x 10(-7) M. In the presence of 7.5 x 10(-7) M tetramethrin, glucagon-induced glycogenolysis was markedly attenuated when glucagon concentration was 10(-9) M or higher. In contrast, tetramethrin had no effect on glucogenolysis evoked by lower concentrations of glucagon. Similarly, tetramethrin greatly reduced gluconeogenesis induced by high concentrations of glucagon without affecting the effect of low concentrations of glucagon. The same results were obtained in the presence of 1 microM extracellular calcium. To abolish glucagon-induced elevation of cytoplasmic free calcium concentration, we heavily loaded quin2 into hepatocytes. In these cells, glycogenolysis evoked by low concentrations of glucagon was completely abolished. Glycogenolysis caused by high concentrations of glucagon was markedly inhibited. These results indicate that glucagon action on hepatic glucose metabolism is mediated by two different mechanisms, which depend on concentrations of glucagon.

The pedicled venous flap. An experimental study

Musculocutaneous pedicled venous flaps on the dorsum of rats survived at a statistically significantly higher rate than musculocutaneous composite grafts (p < 0.01). With a Silastic sheet (Dow Corning) beneath, both composite grafts and pedicled venous flaps necrosed. When a Silastic sheet with holes in it to allow some revascularisation from the bed was placed beneath, the survival rate was significantly better than with a complete Silastic sheet (p < 0.01). These results demonstrate that pedicled venous flap survival depends both on the draining vein, and revascularisation from the underlying bed.

Congenital absence of the portal vein

Absence of the terminal portion of the portal vein and its intrahepatic branches was demonstrated in a 22-year-old woman with focal nodular hyperplasia (FNH) of the liver. Various imaging studies and angiography showed that the portal vein entered into the inferior vena cava just above the renal veins. The clinical and radiological features of this patient and nine previously reported cases of this entity are herein reviewed.

Pertussis toxin blocks activin A-induced production of inositol phosphates in rat hepatocytes

The present study was conducted to examine an involvement of G protein in the action of activin A in rat parenchymal liver cells. Activin A induced a dose-dependent increase in inositol phosphates in cells prelabelled with [3H]inositol. The effect of activin A was completely blocked by pretreatment of the cells with pertussis toxin. In contrast, pertussis toxin had little effect on angiotensin II-induced production of inositol phosphates. Both activin A and angiotensin II inhibited glucagon-mediated production of cAMP. Pretreatment of the cells with pertussis toxin blocked the inhibition induced by both activin A and angiotensin II. In permeabilized cells, activin A augmented production of inositol phosphates. Activin-mediated production of inositol trisphosphate was enhanced by GTP-gamma S and was attenuated by GDP-beta S. These results suggest that a pertussis toxin-sensitive G protein(s) may be involved in the action of activin A in hepatocytes.

Isoflavonoids, genistein, psi-tectorigenin, and orobol, increase cytoplasmic free calcium in isolated rat hepatocytes

Isoflavonoid compounds, genistein, psi-tectorigenin and orobol have been implicated as inhibitors of tyrosine-specific protein kinase and phosphatidylinositol turnover. These compounds have been frequently used as a pharmacological tool to assess signal transduction pathways in various cell systems. In the course of analyzing signaling pathways in rat hepatocytes, we obtained an unexpected finding that these compounds transiently increase cytoplasmic free calcium. Since the Ca2+ mobilizing effect was observed in 1 microM calcium containing buffer, the source of the Ca2+ may be intracellular stores. Thus, when interpreting data obtained using these compounds, caution is needed.

Continuous local intraarterial infusion after prolonged arterial stasis in the fingers and toes

Seven patients with trauma to eight digits and one toe went untreated for arterial stasis, with subsequent development of posttraumatic changes in skin coloration. In two patients involving two digits, a daily dose of 2,000 ml containing 240,000 U urokinase, 80 micrograms prostaglandin E1, and 10,000 U heparin in lactated Ringer's solution was administered by intravenous infusion for 10 consecutive days; one of the two digits became necrotic. In all subsequent patients, a daily dose of 80 ml containing 240,000 U urokinase, 40 micrograms prostaglandin E1, 10,000 U (maximum) heparin, and low-molecular-weight dextran was administered by continuous local intraarterial infusion for 10 consecutive days. These seven extremities survived, even in the case of two digits and one toe with over 50 hr of arterial stasis. We believe that revascularization of extremities following prolonged periods of arterial stasis may be possible by means of continuous local intraarterial infusion of antithrombotic agents.

Comparison of effects of HGF and EGF on cellular calcium in rat hepatocytes

We compared the effects of HGF and EGF on cytoplasmic free calcium concentration, [Ca2+]c, and inositol trisphosphate production in rat hepatocytes. HGF induced a prompt and transient elevation of [Ca2+]c. EGF also induced an immediate increase in [Ca2+]c, the magnitude of which was greater than that by HGF. In contrast, in the presence of 1 microM extracellular calcium EGF increased [Ca2+]c to a lesser extent than HGF. When cells were pretreated with EGF, the effect of HGF on [Ca2+]c was greatly enhanced. However, such enhancement was not observed in medium containing 1 microM extracellular calcium. In hepatocytes prelabeled with [3H]-inositol, both HGF and EGF increased [3H]inositol trisphosphate. HGF and EGF acted synergistically to stimulate production of inositol trisphosphate. These results indicate that both HGF and EGF increase [Ca2+]c by a mechanism involving phosphoinositide turnover and that the actions of HGF and EGF on hepatocyte calcium metabolism are not totally identical.

Mechanism of glycogenolytic action of histamine in rat hepatocytes

The mechanism by which histamine induces glycogenolysis was investigated in rat hepatocytes. Histamine induced stimulation of glucose output in hepatocytes in a dose-dependent manner. The maximal effect of the glycogenolytic action of histamine, which was approximately 60% of the maximal glucagon action, was obtained at 10(-6) M. These effects were inhibited by H1 receptor antagonists triprolidine hydrochloride and tripelennamine but not by a H2 receptor antagonist cimetidine. Histamine also increased the activity of phosphorylase a. When 10(-6) M histamine and 5 x 10(-9) M glucagon were added simultaneously, the actions of these two agents were additive. In contrast, there was no additivity when 10(-6) M histamine and 10(-8) M angiotensin II were added. Histamine did not increase adenosine 3',5'-cyclic monophosphate at any doses tested but induced a rapid increase in the cytoplasmic free calcium concentration ([Ca2+]c). Histamine increased [Ca2+]c even in the presence of 1 microM extracellular calcium, an observation suggesting that histamine caused calcium release from an intracellular calcium pool(s). When [3H]inositol-labeled hepatocytes were incubated with histamine, radioactivity in the D-myo-inositol trisphosphate fraction was rapidly increased. These results indicate that histamine acts on rat hepatocytes mainly via H1 receptors and stimulates glycogenolysis by activating the calcium messenger system.

Histological changes of the gallbladder and liver after extracorporeal shock wave lithotripsy for gallbladder

The histological changes of the gallbladder and liver following extracorporeal shock wave lithotripsy (ESWL) were investigated in a canine model. After performing ESWL on human cholesterol stones placed in the gallbladder of 8 dogs, the gallbladder and livers were removed for pathological study. The mucosa of the gallbladder showed erosion and ulceration in three of the eight dogs. Edema and bleeding were found in the stroma of the gallbladder beds. Hemorrhagic necrosis and vacuolar degeneration occurred in liver parenchyma adjacent to the gallbladder bed, but the portal area was fairly well preserved. It can be said that ESWL caused damage to both the liver and the gallbladder, but its effects on the liver may be only slight because of the preservation of the portal area.

An investigation of venous pressure and oxygen tension in human extremities: an experimental study of survival in pedicled venous flaps

The pedicled venous flap is used at various sites, such as the finger, forearm, and leg. The authors previously reported that the reasons for the viability of such flaps, based on the digital dorsal vein and used for repairing digital skin defects in the earlier study, were high venous pressure or oxygen tension, as well as the possible effects of plasmatic imbibition and outflow through the draining vein. To investigate the importance of venous pressure and oxygen tension in the survival of these flaps at other sites in the body, measurements were made comparing these parameters in the digital vein, cephalic vein, and greater saphenous vein, which are all used clinically as draining veins in pedicled venous flaps. Although measurements in other sites were consistently lower than in the digital dorsal vein, since these other venous flaps are nevertheless viable in the clinical situation, their viability may not be due only to relatively high venous pressure and oxygen tension. The authors intend to carry out further comparative studies on plasmatic imbibition in the flap and outflow through the draining vein.

Interpeduncular high-density spot in severe shearing injury

Thirty cases of severe shearing injury were analyzed utilizing serial computed tomography scans and clinical observations. Fatalities occurred in the majority of patients whose Glasgow Coma Scale scores at admission were 6 or less. The presence of perimesencephalic subarachnoid hemorrhage, hemorrhage in the corpus callosum, acute brain swelling, and intraventricular hemorrhage on computed tomography scans resulted in high mortality rates. In 13 patients, interpeduncular high-density spots were observed on computed tomography scans, which were performed in the acute stage of injury. Eight of these patients died, and those surviving had poorer neurological outcomes than corresponding patients with identical Glasgow Coma Scale scores on admission. In the management of severe shearing injury patients, more attention should be given to the presence of interpeduncular high-density spots as well as other important diagnostic computed tomography findings regarding diffuse brain injury.

Mechanism of prostaglandin E2-induced glucose production in rat hepatocytes

Effects of prostaglandin E2 (PGE2) on glycogenolysis were examined in rat hepatocytes. In a batch incubation system using isolated hepatocytes, PGE2 increased glucose output dose-dependently. The glycogenolytic effect of PGE2 was detected at a concentration of 10(-11) M, and 10(-8) M PGE2 elicited the maximum glucose output, which was equal to that by glucagon. PGE2 did not increase cAMP at any dose tested (10(-11)-10(-4) M). Instead, PGE2 increased the cytoplasmic free calcium concentration ([Ca2+]c). When the effect of PGE2 on [Ca2+]c was studied in aequorin-loaded cells, the effect of PGE2 on [Ca2+]c was detected at 10(-12) M, and the magnitude of the response increased in a dose-dependent manner. PGE2 increased [Ca2+]c even in the presence of 1 microM extracellular calcium, suggesting that PGE2 mobilizes calcium from an intracellular pool. In line with these observations, PGE2 increased the production of inositol trisphosphate. Compared with the action of PGE2, 16,16-dimethyl-PGE2, a PGE2 analog, was less potent in stimulating glycogenolysis. These results indicate that PGE2 stimulates glycogenolysis by activating the calcium messenger system.

Difference in sensitivity to glucagon action in three different rat liver systems

We compared sensitivity to glucagon in three different rat liver systems. In perfused liver, half-maximal response of glycogenolysis was obtained by 5 x 10(-11) mol/L glucagon. In contrast, half-maximal response was obtained by 10(-9) mol/L glucagon in batch incubation of isolated hepatocytes. In perifusion system using the same isolated hepatocytes, 9 x 10(-11) mol/L glucagon induced half-maximal response. In both perfused liver and perifusion system, dose response relationships for glucagon-induced cyclic adenosine monophosphate (cAMP) output were identical. In batch incubation of isolated hepatocytes, again much higher concentration of glucagon was needed to increase cAMP output. Inhibitors of glucagon degradation did not increase the sensitivity of hepatocytes in batch incubation system. When the liver was perfused in recirculation system, glycogenolytic response to glucagon was significantly less than when it was perfused in flow-through system. Also, when extract of lipophilic substances in conditioned medium of batch incubation system was included in perfusate, the glycogenolytic response to glucagon was diminished in perfused liver system. In contrast to the action of glucagon, sensitivities of hepatocytes to calcium mobilizing hormones, phenylephrine, and angiotensin II, in three systems were nearly identical. These results suggest that the diminished sensitivity of hepatocytes to glucagon observed in batch incubation system is due, at least in part, to a substance (or substances) released from hepatocytes.

Stimulation of glucose production by activin-A in isolated rat hepatocytes

The effect of activin-A on glycogenolysis was studied in isolated rat hepatocytes. Activin-A stimulated glucose output in hepatocytes in a dose-dependent manner. The maximal effect of the glycogenolytic action of activin-A, which was about 50% of the glucagon action, was obtained at 10(-9) M. When 10(-9) M activin-A and 5 x 10(-9) M glucagon were added simultaneously, the actions of these two agents were additive. In contrast, there was no additivity when 10(-9) M activin-A and 10(-8) M angiotensin-II were added. Activin-A did not increase cAMP at any doses tested, but induced a rapid increase in cytoplasmic free calcium concentration. Activin-A increased the cytoplasmic free calcium concentration even in the presence of 1 microM extracellular calcium, suggesting that activin-A caused calcium release from an intracellular calcium pool(s). The internal calcium pool affected by activin-A appeared to be the same as that affected by either angiotensin-II or vasopressin. When [3H] inositol-labeled hepatocytes were incubated with activin-A, radioactivity in the inositol trisphosphate fraction was rapidly increased. These results indicate that activin-A acts on rat hepatocytes and stimulates glycogenolysis by activating the calcium messenger system.

[A case of pseudotumor cerebri associated with colon cancer]

A case of pseudotumor cerebri associated with iron deficiency anemia due to colon cancer is reported in a 37-year-old woman. Her initial symptoms were vomiting and severe headache. On physical examination, no lymph nodes and abdominal mass were palpable but marked anemia was noted in her skin and conjunctiva . Neurological examination revealed papilledema in her both eyes and stiff neck. There was no abnormal findings on CT scan on admission. Spinal puncture revealed CSF pressure as high as 620 mmH2O with normal cells, protein, sugar and chloride levels. Hematological examination revealed iron deficiency anemia and thrombocytosis. Angiography at third day revealed no sinus occlusion, but retention of contrast media was seen on the cortical vein of parietal lobe and right transverse sinus. Brain scintigram at sixth day revealed mild accumulation in left parietal lobe, so small venous infarction was suggested. There were two circumscribed stenotic lesions of right ascending colon in the barium enema, and right hemicolectomy was achieved. The pathological diagnosis was adenocarcinoma. The symptoms of pseudotumor cerebri was completely disappeared soon after the surgery together with resolution of anemia. She lives with no deficits now 1 year 3 months after surgery. In conclusion much attention is necessary to a patient of pseudotumor cerebri with iron deficiency anemia for the presence of cancer, because not only this central nervous system lesion is reversible and curable but also the cancer itself may be curable by surgery.

Calcium rather than cyclic AMP is an intracellular messenger of parathyroid hormone action on glycogen metabolism in isolated rat hepatocytes

The synthetic 1-34 fragment of human parathyroid hormone (1-34hPTH) stimulated glucose production in isolated rat hepatocytes. The effect of 1-34hPTH was dose-dependent and 10(10) M-1-34 hPTH elicited the maximum glucose output, which was approx. 80% of that by glucagon. Although 1-34hPTH induced a small increase in cyclic AMP production at concentrations higher than 10(-9) M, 10(-10) M-1-34hPTH induced the maximum glucose output without significant elevation of cyclic AMP. This is in contrast to the action of forskolin, which increased glucose output to the same extent as 10(-10) M-1-34hPTH by causing a 2-fold elevation of cyclic AMP. In addition to increasing cyclic AMP, 1-34hPTH caused an increase in cytoplasmic free calcium concentration ([Ca2+]c). When the effect of 1-34hPTH on [Ca2+]c was studied in aequorin-loaded cells, low concentrations of 1-34hPTH increased [Ca2+]c: the 1-34hPTH effect on [Ca2+]c was detected at as low as 10(-12) M and increased in a dose-dependent manner. 1-34hPTH increased [Ca2+]c even in the presence of 1 microM extracellular calcium, suggesting that PTH mobilizes calcium from an intracellular pool. In line with these observations, 1-34hPTH increased the production of inositol trisphosphate. These results suggest that: (1) PTH activates both cyclic AMP and calcium messenger systems and (2) PTH stimulates glycogenolysis mainly via the calcium messenger system.

[Basic analysis of extracorporeal shock wave lithotripsy of gallstones]

Influence of extracorporeal shock wave lithotripsy (ESWL) on human gallstones placed in dog gallbladders was investigated. After irradiation of shock wave more than 600 times, maximal diameter of residual stones of 10 mm before irradiation was destroyed to 2 mm or less. Levels of serum transaminase (GOT.GPT) were elevated, in parallel with times of shock waves. These results suggested that 600 times of shock waves were enough to destroy one cholesterol stone, diameter of which was about 1 cm. Data of elevation of serum transaminase showed that more than 600 times of shock waves were possible to induce the damage of liver.

Effects of secretin on content of PGE2 and 6-keto PGF1 alpha in gastric mucosa

To determine the involvement of prostaglandins in the action of secretin on the promotion of the healing process in injured gastric mucosa, the effect of secretin infusion on the content of PGE2 and 6-keto PGF1 alpha (a major metabolite of PGI2) in human gastric mucosa was investigated. Specimens of both normal and injured mucosa were obtained from each of the patients who underwent polypectomy a week prior to the study. The specimens were obtained before and 20 min after intravenous infusion of secretin [2 Crick, Harper and Raper (CHR) units/kg] or saline. The basal content of PGE2 in injured mucosa was three times higher than that in normal gastric mucosa. Secretin did not increase the PGE2 content of normal gastric mucosa. However, secretin induced a sevenfold increase in the PGE2 content of injured mucosa. The content of 6-keto PGF1 alpha was not affected by secretin. These results suggest that, in injured mucosa, PGE2 is involved in the healing process and in the action of secretin as well.

Sources of calcium mobilized by glucagon in isolated rat hepatocytes

Effects of glucagon on cytoplasmic concentration of free calcium, [Ca2+]c, were studied in aequorin-loaded hepatocytes. Addition of 5 nmol/l glucagon resulted in a prompt, but transient increase in aequorin bioluminescence. Glucagon, at 5 nmol/l, induced an increase in [Ca2+]c even in medium containing 1 mumol/l calcium, although the response was considerably smaller than that observed in medium containing 1.0 mmol/l calcium. When hepatocytes incubated in the presence of 1 mumol/l extracellular calcium were first stimulated by phenylephrine and subsequently by either glucagon or angiotensin II, there was a response of [Ca2+]c to glucagon, but not to angiotensin II. Dantrolene (50 mumol/l), which inhibits an increase in [Ca2+]c induced by phenylephrine, did not inhibit the increase in [Ca2+]c induced by glucagon. In contrast, dinitrophenol (50 mumol/l) abolished [Ca2+]c response to glucagon without abolishing the increase in [Ca2+]c induced by angiotensin II. These results suggest that glucagon mobilizes calcium from both intracellular and extracellular pools and that the intracellular calcium pool involved in glucagon action may be different from that mobilized by either phenylephrine or angiotensin II.

Evidence of cyclic AMP-independent action of glucagon on calcium mobilization in rat hepatocytes

Glucagon increases the cytoplasmic free calcium concentration as measured by aequorin bioluminescence. It has been proposed by Wakelam et al. (Nature 323 (1986) 68-71) that low concentrations of glucagon mobilize calcium from an intracellular pool by causing polyphosphoinositide breakdown. To identify whether cyclic AMP mediates changes in the cytoplasmic free calcium concentration ([Ca2+]c) induced by glucagon, the effects of forskolin and exogenous cyclic AMP on [Ca2+]c were compared with that of glucagon in aequorin-loaded hepatocytes. Although the magnitudes of the [Ca2+]c responses to 250 microM forskolin and 1 mM 8-bromo cyclic AMP were identical to that of 5 nM glucagon, these two agents induced a more prolonged elevation of [Ca2+]c. Glucagon-induced elevation of [Ca2+]c was accompanied by a smaller increase in cyclic AMP than that induced by forskolin. When the cyclic AMP response to glucagon was potentiated by an inhibitor of phosphodiesterase, 3-isobutyl-1-methylxanthine, the glucagon-induced increase in [Ca2+]c was not affected. Conversely, when the cyclic AMP response to glucagon was reduced by pretreatment of the cells with angiotensin II, glucagon-induced changes in [Ca2+]c were rather enhanced. Furthermore, vasopressin potentiated glucagon-induced changes in [Ca2+]c despite the reduction of the cyclic AMP response to glucagon. In the presence of 1 microM extracellular calcium, angiotensin II did not enhance glucagon-induced changes in [Ca2+]c. These results suggest that at least part of the action of 5 nM glucagon on calcium mobilization is independent of cyclic AMP.

[Clinicophysiological study of multimodality evoked potentials and computed tomographic findings in persistent vegetative state]

The auditory brainstem response (ABR), short latency somatosensory evoked potential (SSEP) and visual evoked potential (VEP) of patients in the persistent vegetative state (PVS) are reported, and the correlations between the electrophysiological findings and the CT scan findings with the three clinical grades of the PVS (transitional, incomplete and complete vegetative syndromes) are discussed. Twenty two patients in a vegetative state caused by subarachnoid hemorrhage (3), hypertensive intracerebral hemorrhage (5), cerebral infarction (6), head injury (3), cerebral anoxia (4) and brain tumor (1). Each evoked response was evaluated for the presence or absence of abnormalities and assigned a grade ranked I to III. Briefly an evoked response was assigned a grade I, II, III if it satisfied the respective criteria of normal, moderately abnormal and severely abnormal or absent electrical activity. On the other hand CT scan findings in the PVS were evaluated for abnormal low density areas, ventricular dilatation and enlargement of the sulci and cisterns indicative of atrophy of the brain parenchyma. SSEP and VEP were better correlated with the clinical grade than ABR, and upper brainstem atrophy and abnormal low density area in CT scan findings were more valuable as an index to expresses the clinical features than ventricular dilatation. On the basis of these results, it is concluded that studies of ABR, SSEP and VEP associated with CT scan findings in the PVS could be a useful diagnostic aid to evaluate the lesions of these patients.

Assessment of the role of Ca2+ mobilization from intracellular pool(s), using dantrolene, in the glycogenolytic action of alpha-adrenergic stimulation in perfused rat liver

To identify the role of Ca2+ mobilization from intracellular pool(s) in the action of alpha-adrenergic agonist, the effects of dantrolene on phenylephrine-induced glycogenolysis were investigated in perfused rat liver. Dantrolene (5 X 10(-5) M) inhibited both glycogenolysis and 45Ca efflux induced by 5 X 10(-7) M phenylephrine. The inhibition by dantrolene was observed in the presence and absence of perfusate calcium. In contrast, dantrolene did not inhibit glycogenolysis induced by glucagon. To confirm the specificity of dantrolene action on calcium release in liver, experiments were also carried out using isolated hepatocytes. Dantrolene did not affect phenylephrine-induced production of inositol 1,4,5-trisphosphate. The compound did inhibit a rise in cytoplasmic Ca2+ concentration induced by phenylephrine both in the presence and absence of extracellular Ca2+. Thus, these results suggest that calcium release from an intracellular pool is essential for the initiation of alpha-adrenergic stimulation of glycogenolysis in the perfused rat liver.

Comparison of the changes in cytoplasmic free calcium concentration induced by phenylephrine, vasopressin and angiotensin II in hepatocytes

Effects of phenylephrine, vasopressin and angiotensin II on cytoplasmic free calcium concentration, [Ca2+]c, were examined by monitoring aequorin bioluminescence in isolated hepatocytes preloaded with aequorin. In the presence of 0.5 mM calcium in the medium, the pattern of changes in aequorin bioluminescence induced by phenylephrine was different from that induced by vasopressin or angiotensin II. When extracellular calcium concentration was reduced to 1 microM, however, these three agents induced identical changes in aequorin bioluminescence. These results suggest that the mode of action of phenylephrine on cytoplasmic free calcium concentration differs from that of either vasopressin or angiotensin II and that the difference in ability to increase calcium influx may account for the distinct patterns induced by these agents.

Evidence for direct effect of tolbutamide on hepatic glycogenolysis induced by Ca2+-dependent hormones

The effects of tolbutamide and glibenclamide on hepatic glycogenolysis in perfused rat liver were investigated. Tolbutamide per se did not influence glucose output from the liver, but at therapeutic concentrations (about 350 microM) it significantly inhibited the glycogenolysis induced by phenylephrine, vasopressin and angiotensin II, while glibenclamide did not. Neither tolbutamide nor glibenclamide inhibited the glycogenolysis induced by glucagon. Tolbutamide potentiated the inhibitory effect of submaximal concentrations of insulin on glycogenolysis induced by phenylephrine. This effect of tolbutamide was elicitable even in the absence of calcium in the perfusate, and was additive to that of trifluoperazine. However, tolbutamide did not potentiate the inhibitory effect of insulin on glucagon-induced glycogenolysis. Tolbutamide inhibited the glycogenolysis induced by A23187, a calcium ionophore. These results indicate that, in addition to its known effect on insulin secretion, tolbutamide has a direct effect on the liver to inhibit glycogenolysis induced by Ca2+-dependent hormones (catecholamines, vasopressin and angiotensin II) and A23187. Thus, it is likely that tolbutamide inhibits the effect of Ca2+ mobilized by Ca2+-dependent hormones to stimulate glycogenolysis.

Inhibition of the glycogenolytic effects of alpha-adrenergic stimulation and glucagon by cobalt ions in perfused rat liver

Cobalt ions (2 mM) inhibited the glycogenolysis induced by phenylephrine and glucagon in perfused rat liver. Cobalt ions also inhibited 45Ca++ efflux from prelabelled livers induced by phenylephrine and glucagon. In addition, they inhibited the rise in tissue levels of cyclic AMP caused by glucagon, but did not inhibit the stimulation of 45Ca++ efflux or glycogenolysis by cyclic AMP or dibutyryl cyclic AMP. The specific binding of glucagon and alpha-agonist to hepatocytes was not inhibited by cobalt ions. These data suggest that cobalt ions, presumably through their high affinity for calcium binding sites on membranes inhibit the stimulation of glycogenolysis by phenylephrine and glucagon in distinct ways; one by inhibiting calcium mobilization and the other by inhibiting cyclic AMP production. Therefore, it is conceivable that membrane-bound calcium plays an important role in stimulating Ca++ mobilization by phenylephrine, and cyclic AMP production by glucagon.

Echocardiographic detection and treatment of intraoperative air embolism

A real-time two-dimensional echocardiogram was used to detect the presence of an air embolism in patients undergoing neurosurgical procedures in the sitting position. The technique could with good sensitivity detect the appearance of a single air bubble intraoperatively, thus allowing early intervention to prevent development of further air emboli. Two types of air embolism could be differentiated; the single-bubble type and the "stormy-bubble" type. The single-bubble type was observed during skin and muscle incisions, craniotomy, and brain lesion excision. Further embolism development was prevented by electrocoagulation and application of bone wax. The stormy-bubble type occurred during dura and muscle incisions and was prevented by electrocoagulation, reflection of the dura, or suturing the affected muscle. The routine use of a Swan-Ganz catheter for removal of air embolism by suction proved effective for the treatment of the stormy-bubble type of air embolism. Masking the operative field with saline-soaked cotton strips was of moderate benefit in the stabilization of the single-bubble type of air influx, but proved to be of little value in controlling the entrance of the stormy-bubble type.

Transpetrosal approach for aneurysms of the lower basilar artery

Extradural subtemporal access to the petrosal ridge and a resection of the anterior pyramidal bone produced direct observation of the lower basilar artery, with minimum retraction of the temporal lobe and preservation of the temporal bridging veins. Two patients with lower basilar trunk aneurysms facing toward the brain stem, were operated on by the "transpetrosal approach," with successful clipping of the aneurysms. Auditory function was preserved in one case. This approach decreases the possibility of retraction damage to the temporal lobe, brain stem, or cranial nerves, and may be helpful for surgery of aneurysms arising around the vertebrobasilar junction or at the origin of the anterior inferior cerebellar artery.

Influence of extracellular phosphate concentrations on the regulation of hepatic glucose output

Experiments were carried out to investigate the role of extracellular phosphate in the hormonal regulation of glycogenolysis in perfused fed-rat liver. Omission of phosphate from the perfusate did not affect the ATP, ADP and AMP contents of the tissue and the basal glucose output from the perfused liver. However, it inhibited significantly the glycogenolysis induced by glucagon, cyclic AMP, phenylephrine and vasopressin but not that induced by 2,4-dinitrophenol. In the absence of perfusate phosphate, the increase in phosphorylase a activity caused by the addition of glucagon, phenylephrine and vasopressin was significantly less than that observed in the presence of perfusate phosphate. Insulin inhibition of the glucagon- or cyclic AMP-induced glycogenolysis was abolished when the perfusion was carried out with the phosphate-free buffer. However, the inhibitory effect of insulin on phenylephrine-induced glycogenolysis was clearly demonstrated even when the perfusate contained no phosphate. These data indicate that in the phosphate-depleted liver, the hormonal control of phosphorylation and dephosphorylation of phosphorylase is impaired. The difference in the phosphate dependency of insulin action on glucagon-and alpha-adrenergic agonist-induced glycogenolysis suggests that the mechanism or site of insulin action on glucagon and phenylephrine is different.

A case of biliary cystadenocarcinoma with recurrent jaundice. Diagnostic evaluation of computed tomography

A 73-year-old male patient with biliary cystadenocarcinoma and episodes of recurrent jaundice is reported. This very rare tumor was suggested as a possible diagnosis by the computed tomographic findings showing intrahepatic cystic masses with septations and papillary projections. The diagnosis of the mucin-producing tumor was supported by aspiration of mucinous bile with a cannule inserted endoscopically via the major duodenal papilla. The computed tomographic findings and the diagnosis were verified by pathologic studies made on the material obtained surgically. The mucinous bile is assumed to have been responsible for the recurrent jaundice.