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.

Effect of amodiaquine on gastric histamine methyltransferase and on histamine-stimulated gastric secretion.

1 Amodiaquine was found to be a potent inhibitor in vitro of gastric histamine methyltransferase from human and canine corpus and from pig antrum. The ID50 for the enzyme, purified from pig antrum mucosa by ultracentrifugation and chromatography on DEAE-cellulose, was 2.5 muM. 2 In six dogs with Heidenhanin pouches the maximum secretory response to histamine (40 mug/kg i.m.) was augmented by i.m. injection of amodiaquine. The augmentation depended on the dose of amodiaquine, the optimum effect (40% increase in volume of gastric juice, 80% in acid output) being achieved with 2 mg/kg. The maximum secretory response to betazole was also enhanced by amodiaquine. 3 It was suggested that amodiaquine may enhance the histamine and betazole stimulated gastric secretion by an inhibition of gastric histamine methyltransferase in vivo.

Concentrations of gastrin and secretin in the alimentary tract of the cat.

The distribution of gastrin and secretin in the alimentary tract of the cat was determined from the esophagogastric junction to the ileocecum. The total content and concentration of each of these hormones in mucosal extracts taken from the gastric fundus, gastric antrum, proximal and distal duodenum, proximal and distal jejunum, and ileum were measured with specific radioimmunoassays. The gastric antrum contained the highest concentration of gastrin, but appreciable amounts also were found in the duodenum. The highest concentrations of secretin were found in the duodenum, but impressive quantities were measured in the jejunum. The role of extra-antral gastrin and of those stores of secretin beyond the proximal duodenum (where the pH probably never falls to levels associated with release of secretin) currently are unknown.

Histamine-induced hypocalcemia in the rat.

The effect of histamine and betazole hydrochloride (Histalog) on serum calcium homeostasis in the rat was studied in these experiments. Either histamine base, histamine phosphate, betazole, or the appropriate control solution was injected intravenously into fasted, anesthetized 80-100 g male rats. Venous blood was collected before and at 30 and 60 min postinjection. Histamine base in doses of 0.5-2.0 mg/rat induced a significant hypocalcemic response 30 min postinjection which returned to baseline by 60 min. Likewise, the administration of 1.375 mg/rat of histamine phosphate (equivalent to 0.5 mg histamine base) also resulted in a significant fall in serum calcium concentration. However, betazole administration, in doses as high as 10 mg/rat, did not lower the serum calcium concentration. In the histamine experiments neither total protein nor hematocrit values differed from control at the time of hypocalcemia. Therefore the changes in serum calcium concentration cannot be explained by hemodilution. These experiments demonstrate that in the rat the administration of histamine results in a hypocalcemic response similar to that previously observed with gastrin.

Two pharmacologically distinct histamine receptors mediating membrane hyperpolarization on identified neurons of Aplysia californica.

Two distinct hyperpolarizing responses are produced when histamine is iontophoretically applied onto the somal membranes of identified neurons within the cerebral ganglion of Aplysia: a biphasic response consisting of a rapid component (less than 5 sec) usually superimposed upon a slowly developing component; or a monophasic slowly developing response 5-20 sec in duration. The reversal potential values for the fast (typically -65 mV) and the slow (typically -89 mV) responses, and their shift to new values when the external potassium or chloride concentrations were altered, revealed that the fast and slow potentials are produced predominantly by conductance increases to chloride and potassium ions, respectively. The effects of histamine H1- and H2-receptor agonists and antagonists were studied to characterize the pharmacological properties of histamine receptors mediating these two ionically dissimilar hyperpolarizing responses. The slow potassium-dependent hyperpolarization could be mimicked by several histamine analogues; the most potent tested were the H1-receptor agonist, 2-methylhistamine, and the H2-receptor agonist, 4-methylhistamine. Neither of these agents mimicked the fast chloride-dependent histamine response. The slow potassium-dependent responses induced by histamine or histamine agonists were completely and reversibly blocked by the H2-receptor antagonist, cimetidine. By contrast, the slow potassium-dependent hyperpolarizations produced by iontophoretically applied acetylcholine or by dopamine to the same neurons were unaffected by cimetidine. Other H1 and H2 antagonists tested were either ineffective, or only partially blocked the slow hyperpolarizations in a non-selective manner. The fast chloride-dependent hyperpolarizations were not selectively antagonized by any of the H1 or H2 reagents tested, although they were effectively suppressed by tubocurarine and strychnine. These data indicate that two pharmacologically distinct histamine receptors mediate potassium- and chloride-dependent hyperpolarizations in Aplysia neurons. Neither of these receptors, however, could be classified as strictly H1 or H2 according to criteria presently used in non-neuronal tissues. The selectivity and reversibility of cimetidine indicate that this particular antihistaminic could be a valuable pharmacological tool for defining putative histaminergic synapses in Aplysia and perhaps other nervous systems.

Central actions of histamine: microelectrophoretic studies.

Responses of neurones in different regions of the rat and cat brain to micro-electrophoretically applied histamine and some related substances including antagonists are reported. Histamine excites most neurones in the hypothalamus but depresses the vast majority of neurones in other structures. Depressant actions of histamine and some inhibitions in the cortex and hippocampus of the rat are antagonized by metiamide, an H2-receptor antagonist. The results lend strong support to the idea of histaminergic transmission in the mammalian brain.

Effects of betazole hydrochloride and cimetidine on common bile pressure and duodenal myoelectric activity in the dog.

Betazole hydrochloride, a histamine analogue that stimulates the H2 receptor, causes an immediate and significant increase in common bile duct pressure. This pressure elevation correlates with an increase in duodenal myoelectric activity. Both the duodenal myoelectric activity and common bile duct pressure immediately returned to near baseline following the administration of cimetidine, an H2 blocker.

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.

Effect of cimetidine on basal and betazole-stimulated gastric acid secretion in peptic ulcer.

The effect of cimetidine, a histamine H2-receptor antagonist, on basal and beta-zole-stimulated gastric acid secretion was studied in 28 patients with peptic ulcer. The results demonstrate that cimetidine (300 mg IM), is a potent inhibitor of both basal and betazole-stimulated gastric acid secretion.

[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.

Effects of intravenous glucose and aminoacids on gastric secretion.

Five healthy females were submited to parenteral nutrition with aminoacids and glucose solution and the acidity and volume of gastric juice were studied. We could find no difference in the obtained values at the various phases, even after the administration of betazole. From this we can conclude that the infusion of aminoacids and glucose does not alter the pattern of gastric secretion.

[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.

A chronic gastrostomy and test system for evaluation of gastric secretions in rhesus monkeys.

We have developed a test system for the evaluation of gastric secretion in the rhesus monkey on a chronic basis that does not require the usual restraining techniques. The system is characterized by ease of animal maintenance and handling, reliability in introducing test substances into the stomach, and long term postsurgical stability. The system comprises a surgical preparation whereby the gastrostomy tube is inserted permanently in the stomach, is passed subcutaneously up the back, and is exteriorized at the top of the skull, and a training procedure that conditions the monkeys so as to facilitate easy handling during the administration of test substances and the collection of gastric controls. Values for pH, volume, total acid, and acid concentration appear reasonably consistent under base-line (no test substance) conditions as well as after the intragastric administration of water or the subcutaneous injection of Histalog.

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.

[The potentiation of stimulated gastric juice secretion by prednisolone]. / Untersuchungen zur Potenzierung der stimulierten Magensäure-Sekretion durch Prednisolon.

In 5 series of dogs the acute effect of a high dose of prednisolone (40 mg/kg i.v.) on Histalog stimulated gastric secretion (5 mg/kg s.c.) was tested. There was no effect of prednisolone alone. The combination of Histalog and prednisolone showed a potentiation of Histalog stimulation in high range. The effect was not seen when truncal vagotomy was performed before stimulation. It is possible that there is a cholinergic reaction or an interaction in the metabolism of histamine.

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.

[Stimulation of the acid secretion of the stomach in rats with and without antrectomy in the perfusion test with betazole]. / Stimulierung der Säuresekretion des Magens mit und ohne Antrektomie im Perfusionsversuch unter Betazol dei der Ratte.

In the perfusion test of the stomach of rats the stimulation of acid secretion by betazol (Histalog) after one or repeated injections was studied. The experiments yielded the following results: 1. The i.v. injection of 20 mg/kg b.w. betazol was followed by a maximun acid secretion. 2. Another infusion two hours later intensified this effect. The same acid secretion was seen after a small initial dose (5 mg/kg b.w.) half an hour before the infusion of betazol. 3. The i.v. infusion of 30 mg/kg b.w. betazol showed in the intact rat stomach a smaller acid dsecretion response than did the dose of 20 mg/kg b.w. In comparison there was a significant higher stimulation with 30 mg/kg b.w. betzaol in the rat after a distal gastrectomy (antrectomy). 4. One s.c. injection of 50 mg/kg b.w. betazol showed a significant acid response of the parietal cells with a duration of at least 7 h on a percentage comparison.