Effects of glycyrrhizin on immune-mediated cytotoxicity

Intravenous administration of glycyrrhizin is known to decrease elevated plasma transaminase levels in patients with chronic viral hepatitis, in which immune-mediated cytotoxicity by cytotoxic T lymphocytes and tumour necrosis factor (TNF)-alpha is considered to play an important pathogenic role. However, the immunological interpretation of the transaminase-lowering action of glycyrrhizin is not known. Studies were performed to elucidate this action immunologically by assessing the effects of glycyrrhizin on immune-mediated cytotoxicity using an antigen-specific murine CD4+ T hybridoma line, which exhibits cytotoxicity against antigen-presenting cells after stimulation with specific antigen, and a murine TNF-alpha-sensitive fibroblast line. Glycyrrhizin inhibited the cytotoxic activity of the T cells against antigen-presenting cells and also suppressed TNF-alpha-induced cytotoxicity in the TNF-alpha-sensitive cell line in vitro. These results suggest that the decrease of elevated transaminase levels by glycyrrhizin in patients with chronic viral hepatitis is mediated in part by inhibition of immune-mediated cytotoxicity against hepatocytes.

Relationship between interleukin-8 levels and myeloperoxidase activity in human gastric mucosa

Although interleukin (IL)-8 is well known as a chemotactic agent for neutrophil migration in vitro, the relationship between IL-8 activity and the degree of neutrophil infiltration in gastric mucosa is still unclear. In the present study, we investigated IL-8 and myeloperoxidase activity, a marker of neutrophil infiltration, in gastric antral mucosa using biopsy samples in 23 patients with no gastric lesions. The results indicate that there is a good correlation between IL-8 and myeloperoxidase activity (y = 0.173x + 13.9; r = 0.49, P < 0.01). Furthermore, IL-8 and myeloperoxidase activity are significantly higher in Helicobacter pylori-positive patients than in H. pylori-negative patients. In conclusion, an increase of IL-8 activity in the gastric mucosa causes increased neutrophil infiltration in human gastric mucosa and H. pylori infection accelerates these reactions in the mucosa.

Binding cells of 125I-iodoamphetamine in rat liver

We recently reported that transrectal or intestinal portal scintigraphy with 123I-iodoamphetamine (IMP) could be a useful method for the non-invasive and quantitative evaluation of the portosystemic shunt in portal hypertension, but what cells in the liver trap IMP has not been clarified. This study was aimed at elucidating whether IMP was extracted by parenchymal cells, sinusoidal endothelial cells, Kupffer cells or fat storing cells. Each type of liver cell was isolated from rats and cultured. The cells were incubated with 125I-IMP and the radioactivity of the lysate was determined. Nonspecific binding was assessed in the presence of an excess of unlabeled IMP, and specific binding was determined by subtracting the nonspecific from total binding. Specific binding observed in parenchymal cells, endothelial cells and Kupffer cells was 70.2 +/- 0.4, 4.2 +/- 1.4 and 2.3 +/- 0.8 pmol/well, respectively, but no specific binding was observed in fat storing cells. The binding in parenchymal cells was much higher than that in endothelial cells or Kupffer cells (p < 0.005). In addition, the binding to parenchymal cells reached equilibrium within 20 min and was not saturable over the concentration range tested (0.5-10 microM). These findings indicate that IMP is mostly extracted by parenchymal cells in the liver.

Effect of the anticholinergic drug with calcium antagonistic activity, (+/-)-4-diethylamino-1,1-dimethylbut-2-yn-1-yl 2-cyclohexyl-2-hydroxy-2-phenylacetate monohydrochloride monohydrate, on lower urinary tract function in rhesus monkeys

NS-21 ((+/-)-4-diethylamino-1,1-dimethylbut-2-yn-1-yl 2-cyclohexyl-2-hydroxy-2-phenylacetate monohydrochloride monohydrate, CAS 129927-33-4) and its active metabolite, RCC-36 ((+/-)-4-ethylamino-1,1-dimethylbut-2-yn-1-yl 2-cyclohexyl-2-hydroxy-2-phenylacetate monohydrochloride), have both anticholinergic and calcium antagonistic activities. NS-21 is under development for the treatment of bladder dysfunction. This study was designed to compare the effects of NS-21 and RCC-36 on the bladder function of monkeys with the effects of various reference drugs. Male rhesus monkeys were anesthetized with a mixture of enflurane and nitrous oxide, a transurethral catheter was inserted into the urinary bladder from the external urethral orifice, and cystometrograms were recorded. Drugs were administered intravenously. NS-21 at doses of 0.3 and 1 mg/kg caused an increase in bladder capacity without affecting the micturition pressure. RCC-36 also caused an increase in bladder capacity, but it was accompanied by a significant decrease in micturition pressure. Oxybutynin, atropine and verapamil all caused decreases in micturition pressure at doses which caused an increase in bladder capacity. Of the drugs examined, only NS-21 caused an increase in the bladder capacity of rhesus monkeys without affecting the micturition pressure. This drug is therefore a promising candidate for the clinical treatment of pollakiuria and urinary incontinence.

Effect of the anticholinergic drug with calcium antagonistic activity, (+/-)-4-diethylamino-1,1-dimethylbut-2-yn-1-yl 2-cyclohexyl-2-hydroxy-2-phenylacetate monohydrochloride monohydrate, on lower urinary tract function in decerebrated dogs

NS-21 ((+/-)-4-diethylamino-1,1-dimethylbut-2-yn-1-yl 2-cyclohexyl-2-hydroxy-2-phenylacetate monohydrochloride monohydrate, CAS 129927-33-4) is a novel compound designed for the treatment of bladder dysfunction. The effects of NS-21 and its active metabolite, RCC-36 ((+/-)-4-ethylamino-1,1-dimethylbut-2-yn-1-yl 2-cyclohexyl-2-hydroxy-2-phenylacetate monohydrochloride), on the urodynamics of decerebrated dogs are reported. Dogs were decerebrated at the precollicular-postmamillary level and the urodynamic effects of intravenously administered NS-21, RCC-36, and various reference drugs were compared by cystometry. NS-21 (0.3-1 mg/kg) and RCC-36 (0.1 mg/kg) caused an increase in bladder capacity without affecting the micturition pressure or residual volume, and thus caused a significant increase in functional bladder capacity. Oxybutynin caused a dose-dependent increase in bladder capacity at 0.1 mg/ kg and higher doses; however, the associated decrease in micturition pressure resulted in a significant increase in residual volume and a decrease in functional bladder capacity. These effects of oxybutynin were similar to those of atropine. Propiverine (0.1-10 mg/kg) and terodiline (0.1-10 mg/kg) caused no significant increase in bladder capacity. In conclusion, in decerebrated dogs, NS-21 and RCC-36 increased the bladder capacity without increasing the residual volume. NS-21 thus had more favorable therapeutic effects than any of the reference drugs tested and is therefore a promising candidate drug for the treatment of pollakiuria and urinary incontinence.

Regenerating gene expression in normal gastric mucosa and indomethacin-induced mucosal lesions of the rat

Regenerating (reg) gene expression was tested in rat gastrointestinal mucosa to investigate the role played by this gene in the healing of mucosal lesions. Expression of reg mRNA was higher in the stomach than in any other region of the gastrointestinal tract. The gastric cells that expressed reg mRNA were located in the deepest mucosal layer and were small in diameter. In an injured state following indomethacin treatment, reg gene expression was markedly augmented, accompanied by an increase of c-fos expression and healing of the mucosal lesions. These results suggest a role of the reg gene in the healing of gastrointestinal mucosal lesions.

Radical esophagogastrectomy for unshuntable extrahepatic portal hypertension with bleeding varices: report of a case

A 29-year-old woman with idiopathic portal hypertension was referred to our department for the surgical management of repetitive bleeding from esophageal and gastric varices. At the age of 16 years she had undergone a splenectomy with esophageal transection followed by endoscopic sclerotherapy which had been performed a total of 24 times. Although vericeal hemorrhage was prevented for several months, bleeding from gastric varices and portal hypertensive gastropathy was not able to be controlled readily by endoscopic sclerotherapy from when she was 26 years old. On admission, angiographic studies showed a complete obstruction of the portal vein; however, a portosystemic shunt operation was not able to be performed due to her previous splenectomy. To control her repetitive bleeding, we decided to perform a total gastrectomy and distal esophagectomy with reconstruction by a Roux-en-Y esophagojejunostomy. Her postoperative course was uneventful, and no episodes of recurrent bleeding or other complications have developed, indicating that her quality of life has dramatically improved. Thus, we conclude that distal esophagectomy and total gastrectomy constitute an effective surgical treatment for unshuntable extrahepatic portal hypertension.

Protective mechanism of high-density lipoprotein against endotoxemia in chronic alcohol ingestion

In the present study, we evaluated the role of high-density lipoprotein (HDL) as an endotoxin-binding protein in chronically alcohol-fed rats. Although the blood endotoxin level was significantly elevated in chronic ethanol-loaded rats, compared with control rats, serum tumor necrosis factor (TNF), ALT, and lactate dehydrogenase were not elevated. Serum HDL and its endotoxin-binding capacity were significantly increased in chronic ethanol-loaded rats. When Kupffer cells isolated from control and chronic ethanol-loaded rats were cultured in the medium containing 3 to 30 mg/dl HDL and endotoxin (500 ng/ml), endotoxin uptake and TNF production of Kupffer cells were decreased in proportion to the concentration of HDL in the medium. These results suggest that the increase in endotoxin-binding capacity of HDL may serve as a protective mechanism against endotoxin in chronic ethanol-loaded rats.

A new adherent form of an attaching and effacing Escherichia coli (eaeA+, bfp-) to the intestinal epithelial cells of chicks

The adherent site of "attaching and effacing Escherichia coli" (AEEC; O103: H-, SK-1 strain) on the intestinal epithelial cells of chicks infected naturally and experimentally was ultrastructurally investigated. The eaeA gene was detected by polymerase chain reaction in the SK-1 strain of E. coli isolated from the intestinal content of a chick infected naturally, however, the bundle-forming pilus (bfp) gene could not be detected. The SK-1 strain (bfp-) of AEEC could attach to the intestinal epithelial cell and induce attaching-effacing lesions in the intestine of chicks. Transmission electron microscopy revealed numerous pilus-like microfilaments in the space between colibacilli and the membranes of the intestinal epithelial cells. The present study suggests that SK-1 strain (eaeA+, bfp-) may attach closely to the intestinal epithelial cells by a novel adhesion different from bfp.

Evaluation of prodrugs ability to induce effective ablation of cells transduced with viral thymidine kinase gene

Transduction of the herpes simplex virus thymidine kinase (HSV-tk) gene into tumor cells followed by treatment with prodrugs is one of the most promising approaches for gene therapy in cancer. The choice of prodrugs is important in order to obtain maximum anticancer effects with minimum adverse reactions. We retrovirally transduced the HSV-tk gene into murine and rat hepatocellular carcinoma (HCC) cells, and investigated their sensitivity to ganciclovir and acyclovir. Retrovirally-mediated HSV-tk transduction did not affect cell proliferation, but led to both ganciclovir- and acyclovir-dependent cytotoxicity in the HCC cells. Ganciclovir exhibited much stronger cytotoxicity on HSV-tk transduced cells than acyclovir. Importantly, HSV-tk transduced cells were completely abrogated at a ganciclovir concentration which was lower than the minimum plasma level achieved in the clinical usage of ganciclovir. Furthermore, HSV-tk transduced cells induced stronger killing of neighboring untransduced cells in the presence of ganciclovir than acyclovir. Ganciclovir may be preferable to acyclovir in the HSV-tk transduction system.

[A case of AFP (alpha-fetoprotein) producing gastric cancer successfully treated with FEP (5-FU, Epirubicin, cisplatin) therapy by continuous venous daily infusion of 5-FU and low-dose CDDP]

We reported our experience with a case of AFP producing gastric cancer with liver metastasis successfully treated with FEP therapy by continuous daily venous infusion of 5-FU and low-dose CDDP. A 59-year-old male was diagnosed with liver metastasis 2 months after partial gastrectomy of gastric cancer and then admitted. The patient received five courses of 24-hour continuous infusion of CDDP (5 mg/day, on day 1, 2, 3, 4, 5) and 5-FU (250 mg/day, on day 1, 3, 5) and bolus infusion of Epirubicin (10 mg/day, on day 3). No remarkable side effect was encountered. Complete response at the liver metastasis was observed by CT scan. Serum AFP level was down from 614 ng/ml to the normal range of 0.5 ng/ml after the therapy. The patient has been well for 10 months with complete remission.

Reg gene expression is increased in rat gastric enterochromaffin-like cells following water immersion stress

BACKGROUND & AIMS

Reg gene has been isolated from regenerating rat pancreatic islets, and subsequent studies have shown a trophic effect of Reg protein on islet cells. However, little is known about the role of Reg protein in the stomach. The aim of this study was to clarify the localization of Reg messenger RNA (mRNA) and its product in the stomach and to examine changes in the level of their expression during regeneration of gastric mucosal cells.

METHODS

Gastric lesions were experimentally induced in Sprague-Dawley rats by water immersion stress. Northern blot analysis and in situ hybridization studies were performed to examine changes in mRNA levels. Immunohistochemical studies were performed to identify the cellular localization and to investigate the change in Reg protein level.

RESULTS

Reg mRNA and its product were distributed in the basal part of the oxyntic mucosa and were expressed mainly in enterochromaffin-like cells. Levels of both Reg mRNA and its product were markedly increased in the water immersion-induced gastric lesions.

CONCLUSIONS

Reg mRNA and its product are expressed in gastric enterochromaffin-like cells, and their levels are increased during the healing process of water immersion-induced gastric lesions.

[The influence of endoscopic injection sclerotherapy (EIS) on respiro-circulatory condition in patients with portal hypertension--the effect of oxygen administration]

We studied the influence of EIS on the respiro-circulatory condition of patients with portal hypertension. Subjects were fifty patients with portal hypertension who were successfully injected more than 5.0 ml of sclerotant into varices. A prospective randomized controlled trial was proposed to elucidate the effect of prophylactic administration of pure oxygen. Twenty-five patients inhaled pure oxygen (O2), remaining twenty-five patients did not during EIS. Respiro-circulatory function of patients was evaluated by monitoring O2 saturation, pulse rate and blood pressure during EIS. PaO2 was measured before and after EIS in seven patients without O2. EIS by the 5% ethanolamine oleate with iopamidol (EOI) was performed under X-ray monitoring. O2 saturation in patients without O2 inhalation was lowered, whereas that in patients with O2 inhalation was stable during EIS. O2 saturation during injection of EOI and after EIS in patients without O2 inhalation was significantly lower than that in patients with O2 inhalation. Pulse rate was significantly lower and a rise in blood pressure was smaller in patients given O2. No significant differences of PaO2 was noted before and after EIS. In conclusion, the monitoring of O2 saturation, pulse rate and blood pressure is necessary during EIS. Prophylactic administration of pure oxygen may be useful for prevention of hypoxic state and respiro-circulatory stabilization during EIS.

Mechanisms of the suppression of the bladder activity by flavoxate

BACKGROUND

This study was designed to clarify the primary site of action of flavoxate, clinically used for the treatment of urinary frequency.

METHODS

In rats, the effect of flavoxate on contractile responses in isolated detrusor strips, bladder contraction induced by pelvic nerve stimulation, isovolumetric rhythmic bladder contractions, and pelvic nerve activity were examined. In decerebrated cats, flavoxate was microinjected into the nuclei in the pons, and its effect on reflex micturition was observed.

RESULTS

Flavoxate suppressed carbachol- and calcium ion (Ca2+)-induced contractions of isolated detrusor strips in a noncompetitive and a competitive manner, respectively. Intravenous flavoxate suppressed both initial phasic, and later tonic, bladder contractions induced by electrical stimulation of the distal end of the pelvic nerve. It abolished isovolumetric rhythmic bladder contractions and the associated efferent pelvic nerve activity, without affecting baseline vesical pressure and afferent pelvic nerve activity. When administered intracerebroventricularly or intrathecally, it abolished isovolumetric rhythmic bladder contractions. Flavoxate microinjected into the nucleus reticularis pontis oralis (PoO; pontine micturition inhibitory region) of decerebrated cats inhibited the reflex micturition, but had no effect when microinjected into the locus coeruleus alpha (pontine micturition center) or locus subcoeruleus (pontine urine storage center).

CONCLUSIONS

Flavoxate suppressed the micturition reflex primarily by facilitating the inhibitory action of the PoO on the descending pathways from the pontine micturition center to the sacral parasympathetic intermediolateral nuclei.

Relationship between Symptom Development and Actual Sites of Infection in Leaves of Anthurium Inoculated with a Bioluminescent Strain of Xanthomonas campestris pv. dieffenbachiae

The infection process of bacterial blight of anthurium was monitored with a bioluminescent strain of Xanthomonas campestris pv. dieffenbachiae. The relationship between symptom expression on infected leaves (assessed visually) and the extent of bacterial movement within tissues (evaluated by bioluminescence emission) varied among anthurium cultivars. In several cultivars previously considered susceptible on the basis of symptom development alone, bacterial invasion of leaves extended far beyond the visually affected areas. In other cultivars previously considered resistant, bacterial invasion was restricted to areas with visible symptoms. In three cultivars previously considered resistant, leaves were extensively invaded by the bacterium, and yet few or no symptoms were seen on infected leaves. The pathogen was consistently recovered from leaf sections emitting bioluminescence but not from sections emitting no light. At an early stage of infection, no significant differences in the percentages of infected areas as determined by visual assessment were observed in any of the cultivars. However, differences among cultivars were detected by bioluminescence as the disease progressed, because bacterial invasion was not always accompanied by symptom expression. In susceptible cultivars, the advancing border of infection was 5 to 10 cm inward from the margins of the visible symptoms and often reached to the leaf petiole even when symptoms were visible in <10% of the total leaf area. Comparisons of anthurium cultivars in which a nondestructive method was used to quantify the severity of leaf infection by a bioluminescent pathogen have enabled us to evaluate susceptibility and resistance to bacterial blight accurately. Such evaluations will be of importance in breeding resistant cultivars for disease control.

Regulation of the human histamine H1 receptor stably expressed in Chinese hamster ovary cells

1. The human H1 receptor gene expressed in Chinese hamster ovary cells (CHOhumH1) encodes a classical histamine H1 receptor with a pharmacology similar to that of the H1 receptor found in guinea-pig cerebellum and the endogenously expressed human H1 receptor in 1321N1 astrocytoma cells as determined by [3H]-mepyramine binding studies. 2. In CHOhumH1 cells, histamine induced a concentration-dependent rise in inositol phosphates (EC50 2.23 +/- 0.97 microM) and a rapid increase of [Ca2+]i, followed by a sustained increase of [Ca2+]i upon addition of 100 microM histamine. 3. Short-term exposure of CHOhumH1 cells to histamine (100 microM) resulted in a decrease of subsequent histamine-induced Ca2+ responses. The histamine-induced desensitization appeared to be heterologous as the ATP-induced Ca2+ response was also found to be affected. 4. The process of heterologous histamine-induced desensitization of the Ca2+ response in CHOhumH1 cells can be ascribed to an alteration at the level of the intracellular Ca2+ pool, as the Ca2+ response of caffeine (10 mM), which releases Ca2+ from intracellular Ca2+ stores was also attenuated upon short-term histamine exposure. 5. In CHOhumH1 cells the PKC activator, PMA, was found to inhibit the histamine (100 microM)-induced Ca2+ response concentration-dependently (IC50 0.2 +/- 0.03 microM) as well as the ATP (100 microM)-induced Ca2+ response. However, this inhibition was only partial and less effective than histamine-pretreatment. Moreover, in CHOhumH1 cells PKC downregulation induced by long-term exposure to PMA (1 microM) did not affect the histamine-induced desensitization nor did pretreatment with the specific PKC inhibitor Ro-31-8220 (10 microM), indicating that in CHOhumH1 cells PKC is probably not involved in the heterologous desensitization. 6. Long-term treatment of CHOhumH1 cells with histamine or other H1 agonists resulted in a time- and concentration-dependent decrease in the number of H1 receptor binding sites (maximal reduction: 47 +/- 5%). 7. Long-term exposure of CHOhumH1 cells to ATP or PMA did not affect H1 receptor density. 8. Both histamine (100 microM)- and ATP (100 microM)-induced Ca2+ responses were affected upon long-term exposure of cells to histamine (100 microM), which might be explained by an alteration at a level distant from the receptor. 9. These results show that in CHOhumH1 cells the human histamine H1 receptor is susceptible to short-term and long-term receptor regulation in which PKC does not seem to play a role. The CHOhumH1 cells therefore provide an excellent model system for studying the mechanism(s) of PKC-independent H1 receptor regulation.