Cigarette smoking delays ulcer healing: role of constitutive nitric oxide synthase in rat stomach

Epidemiological studies have shown that cigarette smoking is associated with peptic ulceration. This study aims to investigate the mechanisms by which cigarette smoking delays ulcer healing in rats. Gastric ulcers were induced by applying acetic acid to the luminal surfaces in rats. Twenty-four hours later, rats were exposed to different concentrations of cigarette smoke (0, 2, or 4%) for a 1-h period once daily for 3 or 6 days. Cigarette smoke exposure delayed ulcer healing and decreased gastric blood flow and angiogenesis at the ulcer margin. These changes were accompanied by a significant reduction of constitutive nitric oxide synthase (cNOS) activity but not PGE2 production and vascular endothelial growth factor levels. Administration of L-arginine (10 mg/kg iv) completely reversed the adverse actions on ulcer healing, gastric blood flow, and angiogenesis in the mucosa at the ulcer margin but partially restored angiogenesis in granulation tissues. In conclusion, cigarette smoke exposure delays ulcer healing through depression of gastric blood flow and angiogenesis at the ulcer margin. Reduction of cNOS expression and activity is suggested to be involved in these ulcerogenic processes.

Retainment of membrane binding capacity of non-palmitoylated Gs alpha mutants expressed in COS-1 cells

Heterotrimeric guanine nucleotide binding regulatory proteins (G proteins) transduce extracellular signals into intracellular signals by coupling receptors and effectors. Because most of the G protein-coupled receptors are integral proteins, the G proteins need to have a membrane binding capacity to receive signals from the receptors. The alpha subunit of G protein binds tightly to the cytoplasmic face of the plasma membrane without any membrane spanning domain. Fatty acylation of G alpha with myristic acid or palmitic acid, in addition to the beta gamma subunits, plays an important role in anchoring the G alpha subunit. The reversible and dynamic palmitoylation of the alpha subunit of stimulatory G protein (Gs alpha) has been suggested as essential for its membrane attachment. However, in our previous experiments, Gs alpha deleted in the amino terminus containing palmitoylation site, retained its binding capacity when expressed in COS cells. Thus, to evaluate the role of palmitoylation in Gs alpha membrane binding, we constructed and expressed non-palmitoylated mutants of Gs alpha and analyzed their subcellular distributions in COS-1 cells. We found that non-palmitoylated mutants of Gs alpha, C3S- and G2A/C3S Gs alpha, retained their membrane binding capacities in COS-1 cells, demonstrating that palmitoylation is not essential for membrane binding of Gs alpha in COS-1 cells. We also found that the palmitoylation did not change significantly the distribution of Gs alpha in Triton X-114 partition. These results suggest that the palmitoylation of Gs alpha may produce different effects on membrane binding depending on cell types.

Well-differentiated papillary adenocarcinoma arising in a supratentorial enterogenous cyst: case report

OBJECTIVE AND IMPORTANCE

We report a case of a well-differentiated papillary adenocarcinoma arising in an supratentorial enterogenous cyst. The clinicopathological features of this case and a brief review of the literature are presented.

CLINICAL PRESENTATION

A 45-year-old woman presented with abrupt onset of sensory seizures and abnormal sensation on the left side of her face, left leg, and left arm. Radiological studies showed a cystic extraaxial tumor with mass effect in the right parietal area. The initial clinical impression was a metastatic lesion, and a comprehensive metastatic workup revealed no evidence of tumor elsewhere.

INTERVENTION

A gross total resection of the solid cystic tumor was achieved by a frontoparietal craniotomy. Sixteen months after the initial surgery, the patient presented with signs of increased intracranial pressure and a large parietal cyst. The cyst was fenestrated at the time of the second craniotomy.

CONCLUSION

A pathological study of the initial surgical material revealed it to be a well-differentiated papillary adenocarcinoma in association with an enterogenous cyst. The second surgical specimen consisted only of the benign cyst wall. The patient recovered uneventfully from the second surgery and was free of symptoms 6 months postoperatively. The importance of recognizing the rare possibility of malignant progression of a benign enterogenous cyst in the central nervous system is discussed.

Suppression of the carbachol-activated nonselective cationic current by antibody against alpha subunit of Go protein in guinea-pig gastric myocytes

In this study, we investigated which subtype of GTP-binding protein (G protein) is related to muscarinic activation of nonselective cation (NSC) channels in gastric smooth muscle. Inward cationic current was activated by the application of 50 microM carbachol (ICCh) at a holding potential of -60 mV with the same CsCl-rich solution in both pipette and bath. The same cationic current as ICCh was slowly activated by the dialysis of guanosine 5'-O-(3-thiotriphosphate) (GTP[gamma-S]) through the pipette. Since it is known that pertussis toxin pretreatment can block ICCh, antibodies (Abs) against Galpha,i (anti-Galpha,i) or Galpha,o (anti-Galpha,o) were tested. Activation of ICCh was blocked by the addition of anti-Galpha,o. However, anti-Galpha,i Abs had no significant effect on ICCh. The expression of Galpha,o in guinea-pig gastric smooth muscle was confirmed by Western immunoblot analysis. These results suggest that Go-type protein may mediate signals from the muscarinic receptor to NSC channel in guinea-pig gastric myocytes.

Histological study of mechanisms of adaptive cytoprotection on ethanol-induced mucosal damage in rat stomachs

Adaptive cytoprotection in the gastric mucosa could be induced by exposure to low concentrations of noxious agents. However, experimental results reported so far were based on macroscopic studies. We aimed to investigate the phenomenon of gastric adaptive cytoprotection of mild irritants and its correlation with intramucosal mucus at the histological level. It was found that histological damage induced by ethanol had a negative correlation with the length of the mucus-secreting layer in the gastric mucosa. Mild irritants such as 20% ethanol and 5% NaCl preserved the 100% ethanol-induced intramucosal mucus depletion, but only the former agent demonstrated a cytoprotective effect against the histological damage, indicating that preservation of intramucosal mucus may not necessarily play a permissive role in adaptive cytoprotection. The capsaicin-sensitive sensory afferent neurons, sensory chemoreceptors, muscarinic receptors, alpha2-adrenoceptors and peripheral dopamine D2-receptors were found to be the components of the autonomic nervous system involved in the cytoprotective processes of 20% ethanol. Endogenous mediators including nitric oxide, prostaglandins, and possibly nonprotein sulfhydryl compounds also seemed to participate in such protection. Nevertheless, 0.3 M HCl did not show any effect either on mucosal damage or depletion of intramucosal mucus induced by absolute ethanol. These findings suggest that only 20% ethanol shows histological cytoprotection, which would involve various components of the autonomic nervous system and endogenous mediators. Furthermore, this investigation also implies a new perspective: that in order to study a true adaptive cytoprotection, histological examination of the gastric mucosa should be performed.

Prostaglandin, tumor necrosis factor alpha and neutrophils: causative relationship in indomethacin-induced stomach injuries

Tumor necrosis factor alpha (TNF-alpha) has been suggested to play a critical role in indomethacin-induced gastric mucosal damage, so we evaluated its mucosal level and its relationship with prostaglandin E2 and neutrophils in indomethacin-induced gastric mucosal injury in rats. Indomethacin caused a time- and dose-dependent increase in gastric mucosal erosion, which was accompanied by a reduction in prostaglandin E2 followed by an increase in TNF-alpha level and neutrophil infiltration in the gastric mucosa. Pretreatment with exogenous prostaglandin E2 totally abolished indomethacin-induced gastric mucosal injury and the TNF-alpha increase. Depletion of neutrophils by methotrexate or reduction of TNF-alpha concentration by pentoxifylline markedly reduced indomethacin-induced mucosal damage. Pentoxifylline but not methotrexate prevented the increase in mucosal TNF-alpha level induced by indomethacin. It is suggested that depletion of prostaglandin E2 followed by an increase of TNF-alpha production and neutrophil infiltration in the gastric mucosa are important sequential processes in indomethacin-induced ulceration. Prevention of one of these processes would inhibit ulcer formation.

Involvement of free radicals and histamine in the potentiating action of cigarette smoke exposure on ethanol-induced gastric mucosal damage in rats

Cigarette smoking has been associated with peptic ulcer diseases. We studied the effects of cigarette smoke exposure on ethanol-induced gastric mucosal damage and its relationship with vascular integrity and the possible role of free radicals and histamine. Male Sprague-Dawley rats were exposed to cigarette smoke followed by ethanol administration (70% v/v). Smoke exposure alone dose-dependently reduced basal blood flow and increased xanthine oxidase (XO) activity but superoxide dismutase (SOD) activity remained unaffected in gastric mucosa. Cigarette smoking followed by ethanol administration significantly potentiated mucosal lesion formation along with augmentation of the mucosal blood flow, vascular permeability and myeloperoxidase (MPO) activity. The potentiating effect of smoking on ethanol-induced gastric mucosal lesion and MPO activity was abolished by pretreatment with allopurinol, terfenadine or ranitidine. Terfenadine and ranitidine also reduced the increased mucosal blood flow and vascular permeability induced by smoking and ethanol combined. These findings suggested that cigarette smoke adversely affected the defense mechanisms of the gastric mucosa by reducing the mucosal blood flow which in turn led to ischemia and increased XO activity. Activation of XO together with histamine H1 and H2 receptors stimulation could lead to neutrophil aggregation and vascular damage. However, the potentiating action of cigarette smoke on ethanol ulceration is unlikely through reduction of SOD activity in gastric mucosa.

The correlation of the weakening effect on gastric mucosal integrity by 5-HT with neutrophil activation

The effects of 5-hydroxytryptamine (5-HT) on ethanol-induced gastric mucosal damage and on epithelial and vascular integrity were investigated. Male Sprague-Dawley rats were administered with 5-HT (5 or 10 mg/kg, IP) 30 min prior to the challenge with ethanol (40% v/v, 10 ml/kg, PO). 5-HT dose dependently aggravated ethanol-induced injury in the gastric mucosa. Both xanthine oxidase (XO) and myeloperoxidase (MPO) activities in the mucosa were significantly increased with the high dose of 5-HT, which also potentiated the elevation of these enzyme activities by ethanol. However, the mucosal superoxide dismutase activity was left unaltered. In neutropenic (antineutrophil serum-treated) animals, the ethanol-induced gastric mucosal injury was significantly ameliorated, with or without the pretreatment of 5-HT (10 mg/kg). In addition, the effect of 5-HT on the activity of MPO, but not of XO, was also attenuated in these animals. In the ex vivo gastric chamber study on pentobarbital-anesthetized animals, volume of gastric secretion was significantly decreased in the 5-HT-treated groups, with further reduction after ethanol incubation. Transmucosal potential difference (PD) was significantly reduced in 5-HT-treated rats, which also potentiated the ethanol-induced drop in PD. Nevertheless, 5-HT dose dependently increased mucosal vascular permeability and further enhanced during ethanol incubation. These findings suggest that 5-HT adversely affects the defense mechanisms of the gastric mucosa by reducing the secretory function of the mucosal cells and to weaken the epithelial and vascular integrity. Neutrophil activation appears to be responsible for the detrimental effects of 5-HT partly through the elevation in MPO activity. The increase in mucosal XO activity by 5-HT may induce free radical production and possibly modulate the ulcerogenic processes.

Reduced responsiveness of [Ca2+]i to adenosine A1- and A2-receptor stimulation in the isoproterenol-stimulated ventricular myocytes of spontaneously hypertensive rats

To determine the modulatory action of adenosine-receptor stimulation on [Ca2+]i responses to beta-adrenoceptor stimulation in the heart of the spontaneously hypertensive rat (SHR), the electrically induced [Ca2+]i transient in response to isoproterenol (ISO) in single ventricular myocytes pretreated with adenosine agonists in SHRs and its normotensive control Wistar-Kyoto (WKY) rats was measured with a spectrofluorometric method by using fura-2/AM as the calcium indicator. In both types of rat, ISO at 0.001-1 microM augmented the electrically induced [Ca2+]i transient, and the effect was blocked by a beta-adrenoceptor blocker, propranolol. In SHRs that did not exhibit cardiac hypertrophy, the resting level of [Ca2+]i and the amplitude of the electrically induced [Ca2+]i transient were the same as those in WKY rats, whereas the augmentation of the electrically induced [Ca2+]i transient in response to ISO was significantly lower than that in WKY rats. In WKY rats, the effects of ISO on the electrically induced [Ca2+]i transient were inhibited by the adenosine A1-receptor agonist, R(-)-N6-(2-phenylisopropyl)adenosine (R-PIA) at 0.01-10 microM. In contrast, the effects of ISO were further enhanced by the adenosine A2-receptor agonist, N6-[2-(3,5-dimethoxyphenyl)-2-(2-methylphenyl)-ethyl)]adenosine (DPMA) at 1-10 microM. In SHRs, the inhibitory effect of R-PIA was significantly reduced, whereas the excitatory effect of DPMA was absent. The effects of both adenosine-receptor agonists in both types of rat were abolished by the respective adenosine-receptor antagonists, 8-cyclopentyl-1,3-dipropylxanthine (DPCPX) and 3,7-dimethyl-1-propargylxanthine (DMPX). The results indicate that the modulatory actions of adenosine-receptor stimulation on [Ca2+]i response to beta-adrenoceptor stimulation in the hearts of SHRs are reduced, which is independent of cardiac hypertrophy.

Telomerase is strongly activated in hepatocellular carcinoma but not in chronic hepatitis and cirrhosis

Telomerase is highly activated in human immortal cell lines and tumor tissues, whereas it is not activated in primary cell strains and many tumor-adjacent tissues. It is suggested that telomerase activation is one of the critical steps in malignant transformation. In the present study, the telomerase activity was investigated in hepatocellular carcinoma tissues and non-tumor liver tissues from Korean patients with chronic hepatitis and cirrhosis. Eighty two liver tissues (24 chronic hepatitis specimens, 34 cirrhosis specimens, and 24 hepatocellular carcinomas) were obtained from 23 chronic viral hepatitis patients, 19 cirrhosis patients (including 7 liver transplants), and 24 patients with hepatocellular carcinoma, of which the surrounding non-tumor liver tissues were available in 16 patients (1 chronic hepatitis and 15 cirrhosis). As negative controls, 3 normal liver tissues were included. Protein from liver specimens was purified by a detergent lysis method as described elsewhere, and telomerase activity was measured in 2 diluents of each sample (1:1 and 1:100) by a telomeric repeat amplification protocol (TRAP). Telomerase was strongly activated in 79% (19/24) of the hepatocellular carcinomas, while weakly in 8% (2/24) of the chronic hepatitis tissues and in 24% (8/34) of the cirrhosis tissues. All of 3 normal control livers showed no telomerase activation. No relationship could be observed between the enhancement of telomerase activity and tumor nature. None of the chronic heaptitis or cirrhosis patients with mild telomerase activation in the liver have developed hepatocellular carcinoma for at least 2 years of follow-up period. These results suggest that the strong enhancement of telomerase activity may be a critical part of hepatocarcinogenesis, although the exact mechanism of such high activation in hepatocellular carcinoma is not clear. In addition, further study will be necessary to clarify the reason why no telomerase activity detectable by a conventional TRAP can be seen in some hepatocellular carcinoma.

Effect of cigarette smoke on ethanol-induced gastric mucosal lesions: the role of nitric oxide and neutrophils

The roles of neutrophil aggregation, inducible nitric oxide synthase activation and chemoattractant, leukotriene B4, in potentiation of the cigarette smoke effect on ethanol-induced gastric mucosal damage were studied. Smoke exposure markedly increased gastric lesion formation following ethanol administration and this was accompanied by substantial increase in gastric mucosal leukotriene B4 concentration, myeloperoxidase and inducible nitric oxide synthase activities. Antineutrophil serum or aminoguanidine pretreatment significantly attenuated both gastric mucosal lesion formation and inducible nitric oxide synthase activity. The increased myeloperoxidase activity was abolished by antineutrophil serum but not by aminoguanidine. These data indicated that both neutrophil mobilization and inducible nitric oxide synthase activation in the gastric mucosa play an important role in the potentiating action of cigarette smoke on ethanol-induced gastric mucosal lesion formation. Increased synthesis of nitric oxide from inducible nitric oxide synthase during gastric damage may be secondary to neutrophil infiltration in the gastric mucosa. Chemoattractant leukotriene B4 could also contribute to neutrophil recruitment in the tissue.

Mechanistic study of adverse actions of cigarette smoke exposure on acetic acid-induced gastric ulceration in rats

Cigarette smoking is associated with peptic ulceration in humans. A mechanistic study of the potentiating effects of cigarette smoking on acetic acid-induced gastric ulceration in rats was hence performed. Rats were exposed to 0, 2 or 4% of cigarette smoke for three 1-hr periods during the 24 hr starvation before ulcer induction. Cigarette smoke exposure potentiated ulcer formation which was accompanied by a reduction of gastric blood flow at the ulcer base and ulcer margin. Further studies showed that cigarette smoke exposure alone did not cause any macroscopic injury in the stomach but significantly decreased the basal gastric blood flow in a concentration-dependent manner, which was coupled with an increase in mucosal xanthine oxidase (XO) activity. Pretreatment with allopurinol (Allo, 5 mg/kg, i.v.), a XO inhibitor, partially prevented the potentiating effect of cigarette smoke exposure on ulcer formation and also significantly improved the gastric blood flow. Ulcer induction itself dramatically increased constitutive nitric oxide synthase (cNOS) activity and prostaglandin E2 (PGE2) level in the gastric mucosa. However, the increment of cNOS activity but not PGE2 level was markedly attenuated by cigarette smoke exposure. Sodium nitroprusside (SNP, 25 or 50 microg/kg, i.v.), a nitric oxide (NO) donor, completely abolished the potentiating effect of cigarette smoke exposure on ulcer formation and also reversed the adverse effect on gastric blood flow. Thus, XO activation and cNOS reduction in the gastric mucosa are closely associated with the potentiating action of cigarette smoke exposure on ulcer formation in rats.

Association between size of the lateral ventricle and asymmetry of the fornix in patients with temporal lobe epilepsy

PURPOSE

Our goal was to determine whether the size of the lateral ventricle influences asymmetry of the fornix in patients with mesial temporal sclerosis.

METHODS

The cross-sectional area of the lateral ventricle was measured along with the thickness of the fornix in 18 patients with pathologically proved mesial temporal sclerosis. Two additional patients with ventricular asymmetry and seizures but without mesial sclerosis were also studied.

RESULTS

Ten of 18 patients with mesial temporal sclerosis had equally sized ventricular areas or less than a 25% difference between the two sides. In seven of these 10, the left and right fornices were equal; in the other three patients, the fornix was thinner on the side of mesial sclerosis. Among the eight patients with ventricular area differences greater than 25%, the larger ventricle was on the side of mesial sclerosis in five cases. In all of these, the ipsilateral fornix was thinner. In three of eight cases, the contralateral ventricle was larger; in two, the left and right fornix were equal; and in one, the fornix contralateral to the side of mesial sclerosis was smaller. The greatest difference in fornix thickness was noted in patients with ventricular asymmetry greater than 40%, regardless of side or presence of mesial temporal sclerosis.

CONCLUSION

The size of the lateral ventricle may influence the apparent thickness of the fornix.

Healing effects of heparin on acetic acid-induced gastric ulcers in rats

OBJECTIVE

To investigate whether or not heparin can accelerate the healing process of acetic acid-induced gastric ulcers in rats and to identify the mechanisms for heparin to produce this effect, so that we can develop a new therapeutic application to heparin besides its traditional anticoagulant activity.

METHODS

Male Sprague-Dawley rats were used to produce acetic acid-induced gastric ulcers. Heparin in the doses of 100, 500, and 1000 U/kg were administered intravenously through the tail vein once daily, starting 1 day after ulcer induction for 7 days in the dose-response experiment or heparin 1000 U/kg at a time schedule of 3, 5, and 7 days in the time-response study, respectively. The gastric mucosal blood flow (GMBF) was measured using a laser Doppler flowmeter under ether anesthesia. The rats were then sacrificed and the ulcer areas were measured. The gastric mucosa was then scraped for the determinations of mucosal prostaglandin E2 (PGE2) level and myeloper-oxidase (MPO) activity.

RESULTS

Heparin in the doses of 500 and 1000 U/kg accelerated the healing of acetic acid ulcers in a dose-dependent manner. The highest dose of heparin also reduced the ulcer areas in a time-dependent fashion. The effect was accompanied by an increase in gastric mucosal PGE2 levels. The same dose of heparin not only decreased the gastric mucosal MPO activity but also increased the GMBF in a time-related manner.

CONCLUSIONS

Heparin with the doses used in the present study accelerated the healing of acetic acid-induced gastric ulcers in rats in a dose- and time-dependent manner, and this action was related to its effects to increase the levels of gastric mucosal PGE2 and GMBF as well as to decrease the gastric mucosal MPO activity.

Helicobacter pylori induces interleukin-8 expression in endothelial cells and the signal pathway is protein tyrosine kinase dependent

Helicobacter pylori (HP) infection has been shown to increase gastric mucosal interleukin 8 (IL-8) expression, and whether HP or its toxin induces endothelial cell IL-8 expression is unknown. We aimed to compare the IL-8 expression in endothelial cells after stimulation with HP toxin, tumor necrosis factor alpha (TNF-alpha), and lipopolysaccharide (LPS) and to study their signal pathways. HP or its toxin induced significant IL-8 expression in endothelial cells. HP toxin, TNF-alpha, and LPS also showed a time- and dose-dependent increase in IL-8 expression over the control. Both protein kinase C (PKC) and protein kinase A (PKA) inhibitors had no effect on IL-8 response to these stimuli. Protein tyrosine kinase (PTK) inhibitor genistein at concentrations of 150, 300, and 450 microM dose-dependently reduced LPS- and TNF-alpha-induced IL-8 expression by 29.43, 43.8, and 47.3% and 20.5, 49.9, and 61.8% respectively, whereas HP toxin-induced IL-8 secretion could only be reduced at 450 microM by 35.7%. Geldanamycin, a more potent PTK inhibitor, at doses of 0.5, 1, and 2 microM dose-dependently reduced HP toxin induced endothelial cell IL-8 expression by 24.8, 26, and 44.3% respectively. It is concluded that HP and its toxin can increase IL-8 expression in endothelial cells, and the expression of IL-8 elicited by HP toxin, TNF-alpha, and LPS is partially dependent on PTK but not PKA or PKC activation.

Ureteral fibroepithelial polyp associated with ureteropelvic junction obstruction in a child

Ureteral fibroepithelial polyp is an unusual benign tumor of a mesodermal origin. It is very rare in infants and children, and the majority of them, excluding ones secondary to chronic irritation, were presented as a single disease without associated lesion. We report a case of multiple ureteral fibroepithelial polyps associated with ureteropelvic junction obstruction in a 5 year-old boy.

The potentiating actions of cigarette smoking on ethanol-induced gastric mucosal damage in rats

BACKGROUND & AIMS

Cigarette smoking has been associated with peptic ulceration. However, the ulcerogenic mechanisms are still undefined. The aim of this study was to investigate the effects and possible mechanisms of cigarette smoke on ethanol- or cold-restraint stress-induced gastric damage.

METHODS

Rats were exposed to cigarette smoke followed by either an ethanol (70%) challenge or cold-restraint stress. The severity of mucosal damage, levels of prostaglandin E2 and leukotriene C4, determined by radioimmunoassay, and neutrophil infiltration in the stomach were assessed.

RESULTS

Smoke dose-dependently potentiated ethanol-but not stress-induced ulcer. It reduced mucosal prostaglandin E2 and increased myeloperoxidase activity. Filtered cigarette smoke did not have these effects. The acidic fraction from the filters produced similar potentiating effects and also delayed ulcer healing. Mucosal leukotriene C4 and serum nicotine levels did not correlate with the mucosal injury in the stomach. Neutropenia abolished the ulcerogenic action and the increase of myeloperoxidase activity produced by both cigarette smoke and acidic fraction.

CONCLUSIONS

Reduction of prostaglandin E2 and increase in neutrophil accumulation in the gastric mucosa are responsible for the potentiating action of acute smoke exposure on ethanol-induced gastric damage. Substances other than nicotine could contribute to these adverse reactions in the stomach.

New scoring system using tumor markers in diagnosing patients with moderate pericardial effusions

We performed diagnostic and therapeutic pericardiostomy with drainage and biopsy in 51 patients with moderate to large pericardial effusions of different etiologies from August 1991 to July 1995. Patients were divided into 4 groups (group 1, tuberculous pericarditis; group 2, suspected tuberculous pericarditis; group 3, acute pericarditis; group 4, malignancy). The pericardial fluid adenosine deaminase level in tuberculosis (87 +/- 10 U/l) was significantly higher than that in malignancy or acute pericarditis (21 +/- 4 U/l, 23 +/- 7 U/l, respectively) (P = 0.0001). The mean pericardial fluid carcinoembryonic antigen level (1.8 +/- 0.3 ng/ml) in benign disease was significantly lower than that (170.7 +/- 46.4 ng/ml) in malignant disease (P = 0.0001). Follow-up study has been done. With a new scoring system (each score 1 for adenosine deaminase > or = 40 U/l, or carcinoembryonic antigen < or = 5 ng/ml) in 25 patients since November 1993, we could diagnose 5 among 7 patients (71%) with tuberculosis, 11 among 13 patients (85%) with malignancy (adenosine deaminase < or = 40 U/l, or carcinoembryonic antigen > or = 5 ng/ml) and 5 among 5 patients (100%) with acute pericarditis (adenosine deaminase < or = 40 U/l, or carcinoembryonic antigen < or = 5 ng/ml), respectively. Our long-term follow-up study suggests that with the new scoring system we can decrease complications or avoid unnecessary procedures or treatments of patients.

The vascular and glandular organoprotective properties of metronidazole in the rodent stomach

BACKGROUND

The gastroprotective action of metronidazole, an antimicrobial used in the therapy against Helicobacter pylori infection, is unclear. Thus, the aim of the present investigation was to study the organoprotective action and antiulcer mechanisms of this drug in rodents.

METHODS AND RESULTS

Metronidazole (10 mg/kg), given either per os or intraperitoneally, 30 min beforehand, reduced ethanol (40%, 10 mL/kg, p.o.)-induced gastric mucosal damage in male rats. Likewise, oral administration of metronidazole dose-dependently attenuated the indomethacin (30 mg/kg, p.o.)-induced gastric lesion formation and the concurrent depletion of mucosal mucus. However, metronidazole did not affect the basal mucosal prostaglandin E2 content. In an ex vivo gastric chamber preparation, 40% ethanol incubation markedly lowered transmucosal potential difference and increased mucosal vascular permeability in rat stomachs. Incubation with all doses of metronidazole did not modulate gastric mucosal blood flow nor transmucosal potential difference, either before or after ethanol treatment. Nevertheless, the increase in vascular permeability by 40% ethanol was significantly alleviated by either p.o. or i.p. metronidazole pretreatment. In addition, exposure of the isolated rabbit gastric gland preparation to metronidazole (10(-5) and 10(-4) M) significantly attenuated the damaging action of 10% ethanol.

CONCLUSION

It is concluded that metronidazole possesses a direct vascular and glandular organoprotective property in the rodent stomach. However, the anti-ulcer action does not appear to involve prostaglandins nor act through the improvement of gastric mucosal blood flow. Preservation of intramucosal mucus may partly contribute to the prevention of indomethacin-induced ulceration in rats.

Electron microscopic perspectives of gill pathology induced by 1-naphthyl-N-methylcarbamate in the goldfish (Carassius auratus Linnaeus)

This experiment has clarified the ultrastructural pathology, by scanning (SEM) and transmission electron microscopy (TEM), induced by 1-naphthyl-N- methylcarbamate (carbaryl) in the gills of juvenile goldfish (Carassius auratus Linneaus). Carbaryl is a low toxicity pesticide commonly used in forestry and agriculture and for controlling aquatic weeds and crustacean predators of shellfish, and has been known to cause gill damage in fish and clams. A variety of cellular changes were observed after exposure of goldfish for 96 h to a sublethal dose of 10 mg carbaryl/l of water. SEM revealed secondary lamellar fusion, distortion, thinning, and mucus release. TEM responses included enlargement of subepithelial lymphatic spaces and mitochondrial disruption and distortion of the lamellar covering epithelium. Pillar cells became detached and chloride cells were vacuolated. Fish were able to withstand these changes in subacute experiments due to redundancy in gill surface area.

GB virus C/hepatitis G virus infection among Korean patients with liver diseases and general population

GB virus C and hepatitis G virus (GBV-C/HGV) have been identified from the patients with acute or chronic liver diseases as possible agents of non-B, non-C hepatitis by two different groups, independently. To investigate whether GBV-C/HGV plays a role among Korean patients with liver diseases, GBV-C/HGV RNA were evaluated in 337 sera by the reverse transcription polymerase chain reaction (RT-PCR) using specific primers derived from 5'-noncoding region of GBV-C/HGV genome. GBV-C/HGV RNA was identified in 11/337 (3.3%). They consisted of 1/160 (0.6%) and 10/177 (3.3%) among the general population and patients with liver diseases, respectively (P < 0.01). Nucleotide sequences of all PCR amplicons were determined by the dideoxy chain termination method and analyzed by molecular evolutionary methods. The phylogenetic tree showed all sequences could be divided into three genotypes. These results indicate that: (1) GBV-C/HGV already exist in Korea; (2) GBV-C/HGV may play some role as an etiologic factor among the Korean patients with liver diseases; (3) GBV-C/HGV infection is rare among Korean general population; and (4) there are at least three different types of GBV-C/HGV in Korea.

Effects of selective beta-adrenoceptor antagonists on gastric ulceration in the rat

Metoprolol and butoxamine, beta-adrenoceptor antagonists which act selectively at the beta 1- and beta 2-adrenoceptors, respectively, have been investigated for their actions on the ethanol, indomethacin and cold-restraint stress ulcer models. Oral administration of butoxamine but not metoprolol significantly attenuated gastric mucosal damage in the three types of ulcer model. Intraperitoneal injection of butoxamine reduced indomethacin ulceration but not that of the other two models. The stimulatory effect of butoxamine on the gastric mucosal potential difference and intramucosal mucus level correlated positively with its anti-ulcer action. Only oral administration of butoxamine significantly increased the mucosal prostaglandin E2 (PGE2) level but not after intraperitoneal injection. Oral administration of butoxamine also significantly increased the mucosal PGE2 level in the three types of ulcer model but this drug was only effective in the indomethacin ulcer model after intraperitoneal injection. Gastric acid and pepsin output were not affected by either drug. Metoprolol significantly reduced systemic blood pressure; this could be attributed to a reduction in gastric mucosal blood flow. These results imply that beta 2-adrenoceptors play a significant role in the pathogenesis of gastric ulceration. We suggest that the anti-ulcer effect of butoxamine was in part a result of strengthening of the mucosal barrier but that this was not effected by modification of acid or pepsin secretions in the stomach. Stimulation of PGE2 in the gastric mucosa could contribute in part to the anti-ulcer action of the drug, especially when given by the oral route.

Regional vascular mechanical properties by 3-D intravascular ultrasound with finite-element analysis

A method employing intravascular ultrasound (IVUS) and simultaneous hemodynamic measurements, with resultant finite element analysis (FEA) of accurate three-dimensional IVUS reconstructions (3-DR), was developed to estimate the regional distribution of arterial elasticity. Human peripheral arterial specimens (iliac and femoral, n = 7) were collected postmortem and perfused at three static transmural pressures: 80, 120, and 160 mmHg. At each pressure, IVUS data were collected at 2.0-mm increments through a 20.0-mm segment and used to create an accurate 3-DR. Mechanical properties were determined over normotensive and hypertensive ranges. An FEA and optimization procedure was implemented in which the elemental elastic modulus was scaled to minimize the displacement error between the computer-predicted and actual deformations. The "optimized" elastic modulus (Eopt) represents an estimate of the component element material stiffness. A dimensionless variable (beta), quantifying structural stiffness, was computed. Eopt of nodiseased tissue regions (n = 80) was greater than atherosclerotic regions (n = 88) for both normotensive (Norm) and hypertensive (Hyp) pressurization: Norm, 9.3 +/- 0.98 vs. 3.5 +/- 0.30; Hyp, 11.3 +/- 0.72 vs. 8.5 +/- 0.47, respectively (mean +/- SE x 10(6) dyn/cm2; P < 0.01 vs. nondiseased). No differences in beta between nondiseased and atherosclerotic tissue were noted at Norm pressurization. With Hyp pressurization, beta of atherosclerotic regions were greater than nondiseased regions: 21.5 +/- 2.21 vs. 14.0 +/- 2.11, respectively (P < 0.03). This method provides a means to identify regional in vivo variations in mechanical properties of arterial tissue.

Co-regulation of mucosal prostanoids and substance P by indomethacin in rat stomachs

The present investigation examined the correlation between the regulation of mucosal prostaglandin (PG) biosynthesis and the release of the neuropeptide substance P (SP) in rat stomachs by indomethacin, a cyclooxygenase inhibitor. When given subcutaneously at the dose of 5 mg/kg, indomethacin reduced mucosal biosynthesis of PGE2 and concurrently lowered mucosal SP level. The inter-relationship between mucosal generation of PG and SP was further demonstrated by using [D-Pro2, D-Trp7,9]-SP, which also inhibited PGE2 production besides its suppression on SP release. Co-administration of either arachidonic acid, the PGE2 precursor, or SP reversed the inhibitory actions of indomethacin and [D-Pro2, D-Trp7,9]-SP, respectively, on mucosal levels of PGE2 and SP. Our findings suggest that indomethacin, aside from its depletion of endogenous PG, also exerts a secondary action in regulating the release of SP, which is mediated indirectly through PG in the gastric mucosa. These actions may play a role in the modulation of gastric mucosal integrity.

Can misoprostol and omeprazole reduce nicotine and ethanol induced gastric mucosal injury? A quantitative macroscopic and microscopic analysis in rats

We compared the effects of misoprostol, omeprazole and methylcellulose (control) on gastric mucosal injury induced by nicotine and/or ethanol. The results demonstrate that misoprostol and omeprazole each significantly reduce macroscopic injury and deep injury at a microscopic level (P < 0.05) induced by nicotine alone, ethanol alone or a combination of ethanol and nicotine. Misoprostol and omeprazole each reduced the leakage of fluorescein isothiocyanate-albumin into the interstitium in the gastric mucosa. Misoprostol and omeprazole are each effective in preventing injury induced by nicotine and ethanol and vascular factors are involved.