Screening of alternative drugs to the tumor suppressor miR-375 in esophageal squamous cell carcinoma using the connectivity map.

OBJECTIVE: The aim of this study was to identify alternative compounds to the tumor suppressor miR-375 using the connectivity map (CMAP) and to validate the antitumor effects of the identified drugs in esophageal squamous cell carcinoma (ESCC). METHODS: Gene profiling of miR-375-treated TE2 and T.Tn cells was applied in order to search the CMAP database. Among the compounds identified using the CMAP, we focused on 8 drugs [(-)-epigallocatechin-3-gallate, metformin, rosiglitazone among others], excluding 2 drugs among the top 10 compounds. We evaluated whether these compounds possess tumor-suppressive functions in ESCC. RESULTS: A cytotoxicity assay showed that the sensitivity of TE2 and T.Tn cells treated with the 8 compounds was evaluated based on IC50 values of 42.9 µM to 3.8 mM. A cell cycle analysis revealed that the percentage of TE2 and T.Tn cells incubated with 6 compounds in the G0/G1 phase or the G2/M phase increased by approximately 40-80%. A TUNEL assay showed that the percentages of apoptotic cells treated with almost all compounds were significantly increased (p < 0.05) compared with the control cells. CONCLUSION: The CMAP database is a useful tool for identifying compounds affecting the same molecular pathways, particularly products that are difficult to apply via practical approaches, such as microRNAs.

Gastric secretory and hormonal patterns in end-stage chagasic achalasia.

Achalasia surgical treatment alters the esophagogastric junction anatomy (cardiomyotomy plus fundoplication or esophagectomy and gastric pull-up), thus favoring a certain degree of gastroesophageal reflux. Gastric secretory and hormonal functioning is not completely known in chagasic patients. The aim of this study was to evaluate the gastric secretory and hormonal response in patients with end-stage chagasic achalasia compared with normal subjects. Gastric secretion and hormonal response were assessed by estimation of gastric acid secretion (GAS) in basal condition and after pentagastrin stimulation, basal serum gastrin, and serum pepsinogen (SP) in basal condition and after betazole hydrochloride (Histalog; Eli Lilly and Company, Indianapolis, IN, USA) stimulation in 27 patients with chagasic achalasia. The results were then compared with those of 24 normal subjects. In the chagasic group, the mean basal and stimulated GAS were significantly lower than in the control group (basal: 1.277 vs. 3.13, P = 0.002; stimulated: 15.9 vs. 35.8, P = 0.0001). Chagasic patients' SG levels showed a significantly higher basal value than the control group (83.3 vs. 36.8, P = 0.0001). There was a significant increase of SP after stimulation compared with the basal levels in both chagasic and control groups. Although the chagasic patients' SP values were higher than the controls, this difference was not statistically significant, either in basal and stimulated conditions (basal: 122.0 vs. 108.9, stimulated 120 min: 177.1 vs. 158.9). In patients with chronic Chagas' disease (ChD), although autonomic denervation does not suppress the strength of the gastric mucosal cells' secretory response to stimulation, it reduces GAS (parietal cell) without, however, affecting SP production (chief cells). On the other hand, the gastrin-producing cells have continuously been stimulated by low GAS.

Development of gastric acid secretion in pigs from birth to thirty six days of age: the response to pentagastrin.

The development of the gastric acid secretory response to pentagastrin was studied using 56 Large White x Landrace pigs, 0-36 days of age, 1.1-13.3 kg body-weight, obtained from 12 litters. Gastric acid secretory capacity was measured using a gastric perfusion technique and intravenous infusion of pentagastrin at dose rates of 2, 4 and 8 micrograms/h per kg. Significant positive linear correlations were found between stomach weight and age, and between stomach weight and body-weight during the 36 day period. The stomach weight to body-weight ratio increased for the first 3 days of age and then decreased during the following 33 days. Basal acid secretion was detected in all unsuckled pigs (n = 9), 2- to 8-h old. Maximal acid outputs in response to pentagastrin in these pigs were 0.16 +/- 0.02 mmol/kg body-weight and 0.034 +/- 0.001 mmol/g stomach weight. For the 56 pigs, significant linear correlations were found between maximal acid output and age, maximal acid output and body-weight, and maximal acid output and stomach weight. There was a significant linear increase in maximal acid output per unit stomach weight during the first 7 days of age, but during the subsequent 29 days the pattern of increase in gastric secretory capacity was slower and curvilinear. In the oldest nine pigs, 24-36 days of age, maximal acid outputs were 0.974 +/- 0.058 mmol/kg body-weight and 0.234 +/- 0.016 mmol/g stomach weight which represents a six to seven-fold increase compared with those determined in pigs at birth. Comparison of gastric acid secretory capacity determined under anaesthesia with that in conscious pigs showed that anaesthesia appeared to suppress basal output but had no effect on pentagastrin stimulated output. Comparison of response to histalog (betazole HCl) and pentagastrin indicated that newborn pigs were more sensitive to histalog but in pigs 9-38 days of age, there were no significant differences in responsiveness to the two secretagogues. These results show that gastric sensitivity to pentagastrin increases rapidly in the first week of life, that the stomach of the newborn pig is more sensitive to histalog than pentagastrin and that studies of the effect of pentagastrin on acid secretion, done under anaesthesia, are comparable to those in the conscious pig.

[Influences of respiratory frequency on breathing mechanics during artificial ventilation in man and animal].

Effects of respiratory frequency on breathing mechanics were examined on 11 surgical patients during artificial ventilation with inhalation of nitrous oxide, oxygen and halothane (GOF). When the respiratory frequency was increased stepwise from 10 to 30/min, the total compliance was significantly reduced stepwise (from 55.42 +/- 9.55 ml/cmH2O to 47.38 +/- 9.31, p less than 0.01). In animal experiment, the respiratory frequency was similarly increased from 10 to 30/min in 11 mongrel dogs under sodium thiamylal anesthesia with air breathing. The total pulmonary compliance decreased significantly from a control level of 13.62 +/- 5.04 ml/cmH2O to a value of 10.96 +/- 3.00 ml/cmH2O which was obtained under the administration of synthetic histamine (betazole hydrochloride) (p less than 0.01). However, the decreases in compliance with histamine were parallel with the control values without the drug treatment. From these results it was assumed that the reduction of the total pulmonary compliance under increased respiratory frequency was due not to changes in small airway but to those in large airway.

2-substituted derivatives of benzimidazole inhibiting gastric acid secretion in rats.

Benzimidazole and its 2-derivatives with amino, carbamonitrile, urea, and guanidine groups have been tested for their activity on gastric secretory process. The carbamonitrile-, urea-, and guanidine compounds decrease gastric acid secretion, basal and stimulated with histamine or betazole, in Shay-rats and depress the guinea pig auricle activity stimulated by betazole. The results suggest that the studied 2-substituted benzimidazole compounds exhibit anti H2-histamine activity.

Inhibitory activity of 2-benzimidazolylurea on gastric acid secretion in rats.

2-Benzimidazolylurea (BIU) decreases gastric acid secretion. The antisecretive activity appears to be associated with antihistaminic and antimuscarinic effects. The antihistaminic activity of BIU appears from its inhibitory effects on betazole stimulated gastric acid secretion and from its inhibitory activity on the isolated guinea pig auricle stimulated by betazole. The antimuscarinic activity of BIU appears from several experiments: this molecule decreases gastric acid secretion stimulated by carbachol in rats, depresses the neostigmine-stimulated motility of duodenum in the anaesthetized cat, lessens the hypertonus of isolated guinea pig trachea caused by pilocarpine and also inhibits guinea pig ileum activity stimulated by acetylcholine. BIU probably depresses gastric acid secretion by interfering with both histamine and acetylcholine receptors.

Effect of nizatidine and cimetidine on betazole-stimulated gastric secretion of normal subjects: comparison of effects on acid, water, and pepsin.

The effect of nizatidine, a new histamine H2 receptor antagonist, on gastric secretory function of eight normal subjects stimulated with betazole, was compared with that of cimetidine. Single oral doses of 75 mg, 150 mg, and 300 mg nizatidine, 300 mg cimetidine, and a placebo were administered on separate occasions 1 h before betazole stimulation. Gastric secretions were recovered in 15-min fractions for the ensuing 2 h, and the pH, H+ concentration and output, volume, and pepsin concentration and output were determined. Doses of 150 mg and 300 mg nizatidine depressed the secretory response significantly more than did cimetidine. The antisecretory effects of 75 mg nizatidine was no different than that of 300 mg cimetidine. Nizatidine 300 mg inhibited pepsin output significantly more than volume. Although pepsin concentration was reduced more than volume, the difference was not significant. These observations, in contrast to results of previous studies, suggest a direct inhibition of pepsin secretion, although to a lesser extent than that of acid.

Histamine H2-receptor of human and rabbit parietal cells.

The histamine H2-receptor on the human parietal cell has been characterized by using dose-response curves and the negative logarithm of the molar concentration of an antagonist (pA2) analyses of cimetidine antagonism of betazole, histamine, and impromidine stimulation in isolated human and rabbit gastric glands. To evaluate the in vitro results, betazole-stimulated gastric acid secretion with and without cimetidine was also studied in healthy subjects. In the in vivo model, individual dose-response curves were shifted to the right with increasing cimetidine concentrations, but this was counteracted by increasing betazole doses, indicating competitive, reversible antagonism. The pA2 values ranged from 6.1 to 6.3. In isolated human gastric glands, impromidine was shown to be eight times more potent than histamine, indicating higher receptor affinity, but the maximally stimulated aminopyrine accumulation was the same as for histamine, and the pA2 values for cimetidine antagonism did not differ significantly, i.e., 5.7 (histamine) and 6.1 (impromidine). In isolated rabbit gastric glands, cimetidine inhibited the histamine- and impromidine-stimulated response with pA2 values of 6.0 and 7.3, respectively. Impromidine was shown to be approximately 100 times more potent than in human gastric glands, whereas histamine had the same potency. This confirms the role of the histamine H2-receptor and suggests a difference between the species concerning receptor affinity.

Perspective on the gastric antisecretory effects of misoprostol in man.

Misoprostol, a synthetic prostaglandin E1 analog, has been found to be safe and effective for the treatment of peptic ulcer disease. This brief overview summarizes the gastric antisecretory effects of misoprostol in healthy human subjects using randomized, double-blind, placebo-controlled studies. Misoprostol effectively and dose-dependently inhibited basal gastric acid secretion at single doses of 50, 100 and 200 mcg/subject. Furthermore, misoprostol effectively inhibited meal-, histamine-, coffee- and tetragastrin-stimulated gastric acid secretion. The inhibition of meal-stimulated gastric acid secretion was not a consequence of the reduction of serum gastrin. In addition, misoprostol inhibited nocturnal gastric acid secretion. In these studies, the titratable acidity, volume, acid output and pepsin activity were inhibited by misoprostol. The extent of the secretory inhibition achieved with the 200 mcg dose of misoprostol was comparable to that of cimetidine administered at a 300 mg dose. The duration of the gastric antisecretory actions was in the order of 3 to 5 hours. We conclude that misoprostol is a potent inhibitor of gastric acid secretion in man.

Inhibition of basal and betazole- and sham-feeding-induced acid secretion by omeprazole in man.

The effect of omeprazole, given as a buffered solution, on basal acid secretion and that induced by betazole and sham feeding in healthy subjects were studied. The three series of experiments showed a dose-dependent acid reduction during the 2nd to 4th h after administration of omeprazole in doses of 10-60 mg, with almost complete inhibition by the highest dose. The ED50 values were of the same magnitude for basal and stimulated acid secretion. This indicates that omeprazole is an equally potent inhibitor of both kinds of acid secretion irrespective of the manner in which the acid is activated.

Curva de gastrinemia: diferença de comportamento a estímulo alimentar entre portadores das formas hepatointestinal e hepatoesplênica da esquistossomose mansônica / Gastrinemia curve: difference of behavior to food stimulation in patients with hepatointestinal or hepatosplenic forms of schistosomiasis mansoni

Avaliamos em 28 indivíduos [9 controles, 10 portadores da forma hepatointestinal (EHI) e 9 da forma hepatoesplênica (EHE) da esquistossomose mansônica] tanto a secreçäo ácida gástrica (basal e após estímulo pelo Histalog) como a gastrinemia basal e após estímulo alimentar. A secreçäo ácida basal nos pacientes dos 2 grupos de esquistossomóticos foi normal mas o valor médio do grupo EHE foi significativamente inferior ao do grupo EHI; näo houve diferença significativa entre as médias da secreçäo ácida após estímulo dos 2 grupos de esquistossomóticos, mas a análise individual mostrou que em 7 pacientes do grupo EHE a secreçäo ácida após estímulo foi menor do que a que ocorreu na maioria dos pacientes do grupo EHI. Quanto à gastrinemia, verificamos ausência de resposta significativa desta ao estímulo alimentar em 7 dos 10 pacientes EHI (e em apenas 2 do grupo EHE e em 1 do grupo controle). Por outro lado, em 5 dos 9 pacientes do grupo EHE (e em apenas 2 dos 10 do grupo EHI) ocorreu resposta aumentada da gastrinemia ao estímulo alimentar. Esses achados mostram, em esquistossomóticos, diferença de comportamento de resposta da gastrinemia a estímulo alimentar, isto é, resposta deficiente no grupo EHI e aumentada no grupo EHE

Effects of cyclic nucleotides, betazole hydrochloride and acetylcholine on pepsinogen secretion from isolated rabbit gastric mucosa.

The effects of dibutyryl cyclic AMP (db-cAMP), dibutyryl cyclic GMP (db-cGMP), betazole hydrochloride (betazole) and acetylcholine (ach.) on pepsinogen secretion from isolated rabbit gastric mucosa were studied using an organ culture system. The 10(-3) M db-cAMP, but not db-cGMP of any concentration, produced a significant enhancement of pepsinogen secretion into the culture medium. In the presence of aminophylline (phosphodiesterase inhibitor), betazole stimulated pepsinogen secretion at concentrations of 10(-8), 10(-6) and 10(-4) M. The 10(-4) M betazole stimulated pepsinogen secretion most strongly (208% of control) and 10(-6) M betazole induced submaximal secretion (137% of control). Ach. stimulated pepsinogen secretion at 10(-8), 10(-6), 10(-4) and 10(-2) M. The peak secretion occurred at 10(-4) M ach. (303% of control). Betazole (with aminophylline) against a background of 10(-6) M ach. (submaximal stimulation dose), produced an intense stimulation of pepsinogen secretion at the concentrations of 10(-8), 10(-6) and 10(-4) M, and the secretion rate expressed as percent of control were 277, 350 and 329%, respectively. These responses were not considered the additive action by betazole and ach. but the potential interaction between the two agents in pepsinogen secretion. From these findings, we conclude that betazole-ach. interdependency exists in in vitro pepsinogen secretion.

Liberation of hydrogen from gastric acid following administration of oral magnesium.

We are in the process of developing a noninvasive test for gastric acid secretion based on the reaction of orally administered magnesium metal with gastric acid: Mg + 2HCl in equilibrium with MgCl2 + H2. We hypothesized that the hydrogen gas thus evolved could be detected in exhaled air and belches and that the amount of hydrogen released could be related to the amount of acid in the stomach. To validate this hypothesis, we gave magnesium to two groups of young adult volunteers following either betazole stimulation or cimetidine inhibition of acid secretion. In group I we gave subcutaneous betazole and gave magnesium in doses from 10 to 200 mg. In group II we gave oral betazole and used a constant dose of 150 mg of magnesium. In both groups we consistently detected significant increases in breath and belch hydrogen following magnesium in the betazole-stimulated volunteers. This response was blocked by cimetidine. The magnitude of the response was related to the magnesium dose, with 150 mg appearing to induce a maximum response. Administration of oral magnesium up to 200 mg was not associated with any untoward effects. We conclude that magnesium led to the release of hydrogen gas in vivo and that the quantity of hydrogen gas recovered was related to the amount of gastric acid. With further development, this principle might be used to develop a simple noninvasive test for gastric acid secretion.

The development of acid and pepsin (EC 3.4.23.1) secretory capacity in the pig; the effects of age and weaning. 1. Studies in anaesthetized pigs.

The development of gastric secretory capacity of hydrochloric acid and pepsin (EC 3.4.23.1) was studied in thirty-eight Large White X Landrace pigs from the litters of six sows (three pairs of two), 9-38 d of age. The pigs of each pair of sows were born within 24 h of each other. The pigs of a litter were paired according to sex and size and cross-fostered, i.e. one pig from each pair was allocated to each sow. One litter from each pair was reared entirely by the sow (milk-fed, MF) whereas the other litter was reared by the sow for 21 d, but was allowed access to solid food (210 g crude protein (nitrogen X 6.25)/kg) at 12 d and was entirely dependent on solid food after 21 d (creep-fed, CF). Following a 14-18 h fast, pigs were anaesthetized (Halothane-sodium pentobarbitone) and their stomachs perfused at a constant rate with Ringer solution. Gastric secretion was stimulated by intravenous infusion of betazole hydrochloride (Histalog) at 3 mg/kg per h for 2 h. Hydrochloric acid and pepsin were measured in the perfusate which was collected at 15-min intervals. There were significant positive correlations between stomach weight and body-weight for both MF and CF pigs. The slope of the regression line for CF pigs was significantly greater than that for MF pigs (P less than 0.01). There were significant positive correlations between maximal acid output and stomach weight for both MF and CF pigs. There were significant positive correlations between maximal pepsin output and stomach weight for both MF and CF pigs. The slope of the regression line for CF pigs was significantly different from that for MF pigs (P less than 0.01). There were also significant positive correlations between maximal pepsin output per unit stomach weight and stomach weight for both MF and CF pigs. The pattern of development of pepsin secretory capacity in both CF and MF pigs was different from that for acid secretion. Maximal outputs of acid per unit stomach weight for MF and CF pigs remained relatively constant. Maximal outputs of pepsin per unit stomach weight and per unit body-weight increased with age for both MF and CF pigs. The results indicate that pigs given access to solid food before weaning and weaned on to solid food have heavier stomachs and greater acid and pepsin secretory capacity than pigs fed entirely on sows' milk.

Effect of H2 histamine receptor blockade and stimulation on urinary acidification.

Acid secretion by the stomach is enhanced by H2 histamine stimulation and is depressed by its inhibition. The present investigation was undertaken to assess the possible effect of H2 histamine activity on acid excretion by the kidney, the other major acid secreting organ. The study was stimulated by an earlier observation indicating a fall in urinary acid excretion in human associated with short-term administration of an H2 histamine antagonist (cimetidine). Female Sprague-Dawley rats were randomly assigned to the cimetidine-treated, histolog-treated and placebo-treated (control) groups. Urinary titratable acidity, NH4+, HCO3- and net acid excretion rates were determined following administration of either cimetidine, histolog or placebo. Excepting the above pharmacologic manipulations all other experimental conditions were similar. Urinary titratable and net acid excretion rates were significantly reduced with cimetidine and increased with histalog as compared with the control group. The observed urinary changes are not due to the effects of these agents on gastric acid secretion since if that was the case the opposite results would have been expected. The data suggest that urinary acidification is somehow influenced by acute changes of H2 histamine activity in rats. The precise mechanism, site of action in the kidney and pathophysiologic significance of this phenomenon remains to be elucidated.

Inhibition of histalog-stimulated gastric secretion by 40 749 RP, a new long-acting gastric antisecretory agent.

40 749 RP, an N-methyl-2-(2-pyridyl)-2,3,4,5-tetrahydro-2-thiophene carbothioamide derivative, is already known as a potent gastric antisecretory agent in animals and in man. In order to determine its duration of action, its activity was investigated on Histalog-stimulated gastric acid secretion in 6 healthy volunteers. The efficacy of a 2 mg/kg dose, compared with that of placebo, was potent, and remained the same when the drug was ingested 6 h before stimulation instead of 1 h. The duration of action of 40 749 RP is therefore longer than 6 h.

Gastric function and obesity: gastric emptying, gastric acid secretion, and plasma pepsinogen.

Because rapid gastric emptying and a shortened satiety period might contribute to development of obesity, this study compared gastric emptying of acaloric liquid, gastric acid production, and plasma levels of gastrin and pepsinogen I (PG I) and II (PG II) among obese and nonobese Pima Indians. Rates of fractional gastric emptying and of gastric acid secretion were similar in the two groups, basally and after an acaloric liquid meal. Basal and postprandial plasma gastrin levels did not differ significantly in obese and nonobese Pimas , but peak betazole-stimulated gastric acid output was greater in the obese group, except when normalized by body weight. The plasma PG I and PG II concentrations and PG I/PG II ratio did not differ significantly between the two groups, but the PG I/PG II ratio had a positive correlation with peak acid output. No correlation was found between fractional gastric emptying rate and degree of obesity. We conclude that an increased gastric emptying rate for liquid does not contribute to the pathogenesis of obesity in Pima Indians.

[Gastric mucosal changes induced by the augmented Histalog test: endoscopic and histopathological study]. / Alteracões da mucosa gástrica provocadas pelo teste aumentado do Histalog: estudo endoscópico e histopatológico.

A prospective study of the effects of maximal doses of betazol hydrochloride ( Histalog ) on the endoscopic and histologic findings of the gastric mucosa of volunteers was made. Of the 11 patients examined, no alteration was seen on gastroscopic examination after Histalog in three, slight to moderate congestion of the mucosa in six and scattered oozing bleeding points in two. The study of the histologic findings revealed no statistical significant difference in the recurrence of erosion, hemorrhage and edema in the antrum and body gastric mucosa, before and after the administration of Histalog . It was concluded that maximal doses of Histalog cause no significant hemorrhage in the mucosa of the stomach and that the brown colour frequently seen in the gastric secretions of the final portions of a Histalog test is to be attributed to trauma to the mucosa by the nasogastric tube and to Histalog induced congestion of the mucosa.