Laparoscopic surgery. A difference.
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Humans↗
Biomedical subjects
N Basso
Publications and source records attributed to N Basso.
Time-related interference of misoprostol with experimental gastric cancer formation induced by N-methyl-N'-nitro-N-nitrosoguanidine in the rat.
The purpose of this study was to investigate the effect of long-term misoprostol administration, at non-antisecretory doses, on N-methyl-N'-nitro-N-nitrosoguanidine(MNNG)-induced gastric carcinogenesis. The incidence of gastric carcinomas and precancerous lesions was evaluated in 50 male 250-g Sprague-Dawley rats after 52 weeks of continuous oral administration of MNNG (120 mg/l; n = 20), MNNG plus misoprostol (2 mg kg-1 day-1; n = 20) or tap water (n = 10) (experiment 1), and in 30 rats treated with MNNG for 30 weeks followed by tap water (n = 15) or by misoprostol (n = 15) for 22 weeks; a third group (n = 10) received tap water only for 52 weeks (experiment 2). After sacrifice, gastric mucosal lesions were macroscopically evaluated and their histology obtained. MNNG consumption was comparable in all groups (6.5 +/- 1.1 mg rat-1 day-1). Misoprostol consumption was 180 +/- 0.25 mg kg-1 day-1 rat-1. In experiment 1 the incidence of gastric carcinomas was 60% in the MNNG group and 25% in the group treated with MNNG plus misoprostol (P less than 0.05). Cytotoxic and hyperplastic gastric mucosal lesions were also significantly reduced by misoprostol. In experiment 2 the incidence of carcinomas was 31% and 38.6% respectively. Misoprostol significantly decreased the incidence of gastric cancer formation when given from the beginning of the experiment. By contrast, when administered after 30 weeks of MNNG treatment it did not interfere with experimental gastric cancer formation. Exogenous prostaglandins are able to prevent the early MNNG-induced gastric mucosal lesions, thus interfering with gastric carcinogenesis.
Adenocarcinoma↗
Interphasic nucleolar organizer regions expression and cell kinetics evaluation during gastric carcinogenesis induced by nitrosoguanidine in the rat.
An increased number of interphasic nucleolar organizer regions containing ribosomal cistrons associated with argyrophilic proteins (AgNORs) has been described in human malignant tumor cells. In this study variations in AgNOR numbers have been compared with changes of cell kinetics, evaluated by the mitotic count (MC) and bromodeoxyuridine labeling index (BrdU LI), during gastric carcinogenesis induced with N-methyl-N'-nitro-N-nitrosoguanidine (NG) in rats. Significant differences (2 P < 0.005) in AgNOR mean numbers, evaluated in the antral isthmic cells, in MC mean values and BrdU LI, evaluated in the whole antral cellular population, were found when comparing areas of acute gastritis, atrophy and hyperplasia in NG-treated rats with the normal mucosa in controls. No differences were observed in MC and BrdU LI between normal antrum and carcinoma cells which showed an AgNORs mean number lower than in the isthmic cells of controls (2 P < 0.005). Moreover, significant correlations were found comparing changes in AgNOR numbers with MC (r = 0.89, P < 0.001) and BrdU LI (r = 0.66, P < 0.001) in different lesions. These data show that evaluation of AgNOR numbers does not allow the identification of malignant cells in NG-induced gastric carcinoma. However AgNOR quantification seems to be a reliable index of cell kinetics and related well with the cellular dividing fraction.
Adenocarcinoma↗
[Laparoscopic cholecystectomy: analysis of first 203 cases].
Laparoscopic cholecystectomy is a valid alternative to open cholecystectomy. The Authors present their experience in the management of 208 consecutive patients. The low incidence of complications, the short hospital stay as well as earlier return to work, and lower medical expenses are the advantages of laparoscopic surgery. The latter is, therefore, more suitable for the treatment of benign gallbladder diseases.
Cholecystectomy↗
Sequential evaluation of gastric intraluminal prostaglandin E2 release, acid secretion and DNA-flow cytometry in N-methyl-N-nitro-N-nitrosoguanidine gastric carcinogenesis in the rat.
The study was initiated to evaluate the sequential changes of gastric intraluminal prostaglandin E2 (PGE2), gastric acid secretion and of the DNA-flowcytometric patterns during gastric carcinogenesis induced by 45-week N-methyl-N-nitro-N-nitrosoguanidine (NG) administration in the rat. Twenty male chronic gastric fistula Sprague-Dawley rats received NG solution (120 mg/l) for 45 weeks and 20 were used as controls. Samples of gastric juice (1 h) were obtained from all animals under basal conditions and every 5 weeks until the end of the experiment. Aliquots of gastric juice were titrated with 0.1 N NaOH. Other aliquots were extracted with ethylacetate and processed for specific PGE2 RIA. On the day following gastric juice collection a gastric lavage and gastric biopsies (n = 4) were obtained through the fistula and processed for flowcytometry. All surviving animals were killed after 45 weeks and histology was obtained. The incidence of cancer in NG treated chronic gastric fistula rats was 66%. Flowcytometry segregated at an early stage (30-35 weeks) those animals which were to develop gastric carcinoma from those which were not. Administration of NG decreased gastric secretion volume, acid and intraluminal PGE2 concentration both in animals developing and not developing cancer. During the last 10 weeks a sharp rise in gastric intraluminal PGE2 concentration was observed in tumor-bearing animals only probably due to production by tumor cells. Prostaglandin deficiency may contribute to the NG-induced mucosal damage and may be involved in gastric carcinogenesis.
Animals↗
Basal and somatostatin-stimulated gastric intraluminal prostaglandin E2 in patients with gastric ulcer and with gastric adenocarcinoma.
The effect of somatostatin-14 (SST), at doses utilized in clinical practice, on gastric intraluminal prostaglandin (PG) E2 release was evaluated in 8 endoscopically normal subjects, in 6 patients with benign gastric ulcer and in 8 patients with gastric adenocarcinoma. In normal subjects, SST induced a significant increase in gastric intraluminal PGE2 concentration and output, whereas it did not augment the concentration and output of PGE2 in patients with gastric ulcer and with gastric cancer. The altered PG response to SST stimulation shown by gastric ulcer and gastric cancer patients may be related to a modified cell population in the gastric mucosa and/or to a defective regulation of this local gastric mucosal mediator.
Adenocarcinoma↗
Development of renovascular hypertension after central serotonin depletion.
The participation of the central serotonergic system in the development of two-kidney, two clip (2K2C) Goldblatt renovascular hypertension in the rat has been examined. Half of the rats were treated with desmethylimipramine intraperitoneally and 5,7-dihydroxytryptamine intracisternally; the other half received only desmethylimipramine and the 5,7-dihydroxytryptamine vehicle. Two days later, a silver clip was placed in both renal arteries in half of the rats of each group. A sham operation was performed in the remaining rats. Blood pressure was recorded during the 5 weeks after treatment. At the end of the experiment, blood and cerebrospinal fluid samples were obtained. The brain was dissected into several areas and kept frozen. Norepinephrine, serotonin, angiotensinogen, and renin-like concentration were evaluated in the brain areas. Plasma renin activity and angiotensinogen concentration in the plasma and cerebrospinal fluid were estimated. In the sham-operated groups, blood pressure was lower in the treated than in the control rats. The curve of blood pressure increase, as well as the final blood pressure, was similar in the treated and control 2K2C rats. Serotonin was significantly depleted by the 5,7-dihydroxytryptamine treatment in all brain areas. Treatment did not induce any changes in central norepinephrine concentration. Plasma renin activity was diminished in the treated sham-operated rats. These data indicate that the central serotonin depletion does not prevent the development of hypertension and confirm the role of the amine in normal blood pressure regulation. On the other hand, the peripheral renin-angiotensin system might participate in the development of high blood pressure in serotonin-depleted animals.
5,7-Dihydroxytryptamine↗
Further studies on the noradrenergic and the renin-angiotensin systems in the brain of the rat.
Previous investigations have shown that depletion of brain norepinephrine (NE) induced by chemical sympathectomy resulted in significant changes in the central renin-angiotensin system. The purpose of the present work was to increase the NE concentration in the central nervous system (CNS) in order to analyze its effect on the peptidergic complex and on the blood pressure (BP) levels. Treated rats were given the following drugs in the drinking water: 1-dopa (12 mg/rat/day), carbidopa (6 mg/rat/day) and pargyline (10 mg/rat/day) during 25 days. BP was determined, blood and cerebrospinal fluid (CSF) samples were obtained. The CNS was dissected into several areas. NE, angiotensinogen (AoC) and renin concentration (RC) were determined in the brain parenchyma; AoC was evaluated in CSF and plasma samples. Pharmacological treatment resulted in an hypotensive effect and, at the same time, an increase of NE in the CNS (about 100%; p less than 0.0005). These changes were accompanied by a significant decrease in the peripheral and central AoC. These results add new evidence to the postulated relationship between these two important regulatory systems involved in cardiovascular control.
Angiotensin II↗
The renin-angiotensin system in different stages of spontaneous hypertension in the rat (S H R).
The present study analyzed the concentration of renin-like activity and angiotensinogen concentration (AoC) in different brain areas related to cardiovascular control in SHR and Wistar Kyoto (WKY) animals. Male rats of both strains were studied at 8, 16 and 30 weeks of age. The following brain areas were isolated: anterior, medial and posterior hypothalamus, septal area, periaqueductal gray (PG) and the remaining brain stem; nucleus tractus solitarius (NTS) and the remaining medulla oblongata. Plasma renin activity (PRA) and plasma and cerebrospinal fluid (CSF) AoC were determined. Renin-like concentration was higher in SHR than in WKY in the anterior hypothalamus, PG and NTS at different stages of hypertension development. AoC was also higher in some areas of the SHR brain during different periods. PRA, plasma and CSF angiotensinogen concentration showed significant differences between both strain of rats during the development of high blood pressure. Present data support the possibility that the central and peripheral renin-angiotensin system may participate in the maintenance of high blood pressure in the SHR animals.
Age Factors↗
Role of prostaglandins in the early phases of experimental gastric carcinogenesis in the rat.
The study was initiated to evaluate the effect of N-methyl-N-nitro-N-nitrosoguanidine (NG) on gastric intraluminal prostaglandin release during a 30-day treatment period and to investigate the effect of a stable prostaglandin E1 analogue (misoprostol) on NG-induced gastric mucosal damage during the same time period. Samples of gastric juice (1 h) were obtained from 40 male Sprague-Dawley rats with chronic gastric fistulas, in basal conditions and after 5, 15 and 30 days of continuous oral administration of NG (120 mg/l) or tap water. Aliquots of gastric juice were titrated with 0.1 M NaOH. Other aliquots were extracted with ethyl acetate and subjected to specific radioimmunoassay for prostaglandin E2. The severity of gastric mucosal lesions was evaluated in 60 rats after 5 days and 30 days of continuous oral administration of NG (120 mg/l) or NG plus misoprostol (200 micrograms/kg-1/day-1) or tap water, and a histological study was carried out. Administration of NG induced a significant decrease of gastric intraluminal prostaglandin E2 concentration at 15 and 30 days. Oral administration of misoprostol, at non-antisecretory doses, protected the rats against NG-induced gastric mucosal damage. Prostaglandins may be involved in the early phases of experimental gastric carcinogenesis.
Animals↗
The central and peripheral renin-angiotensin and noradrenergic systems in the spontaneous hypertensive rats (SHR).
The aim of this study was to evaluate the components of the renin-angiotensin system in the periphery and in the central nervous system (CNS) of the spontaneous hypertensive rats (SHR). On the other hand, the norepinephrine (NE) content of the different areas and of the mesenteric artery were also measured. Sixteen SHR and 9 Wistar Kyoto (WKY) control animals were used at about 6 months of age. Blood and cerebrospinal fluid (CSF) samples were collected. The brain was dissected into several areas and the mesenteric artery was excised. Plasma renin activity (PRA), plasma angiotensinogen concentration (P1AoC), brain renin (RC) and angiotensinogen concentrations (AoC) were evaluated by radioimmunoassay. NE was determined in all the tissues by a fluorimetric technique. PRA, P1AoC and NE concentration in the mesenteric artery were similar in both groups. An increase in the NE content of the cerebellum was detected in the SHR without changes in the other areas of the CNS. AoC was decreased in the CSF and in the brain stem of the SHR animals. RC was evaluated in the hypothalamus, brain stem, cerebral cortex and cerebellum of the same strain of rats. These results seem to indicate the some alteration of the peptidergic system in the CNS is present in the hypertensive animals.
Animals↗
Effect of ketanserin and prazosin on blood pressure and cardiovascular reactivity to vasopressor agents during the development of two kidney-two clip renal hypertension in the conscious rat.
The present experiment was performed in order to evaluate some of the actions of ketanserin, a blocking agent active at the serotonin 2 (S2) receptors. Male rats were divided into: 1. Two kidney-two clip (2K-2C) renal hypertensive: a silver clip (0.25 mm width) was placed in both renal arteries. 2. Sham-operated: a similar operation without placing the clip was performed. Blood pressure (BP), heart rate and pressor responses to tyramine, angiotensin II and norepinephrine (NE), and the hypotensive effect of prazosin (Pz) and ketanserin (Kt) were recorded in the conscious animals 8 weeks later. Results showed that Pz produced a similar decrease in BP in hypertensive and sham animals while Kt lowered BP much more in hypertensive than in normotensive rats. Prazosin abolished the pressor response to tyramine while ketanserin only diminished tyramine effect. Both hypotensive agents shifted the dose-response curve to NE to the right. Present data have shown that ketanserin and prazosin are effective hypotensive agents in 2K - 2C renovascular hypertension in the rat. They also suggest that both hypotensive compounds have an alpha 1-blocking effect, somehow they seem to have some differences in their pattern of pharmacological action.
Adrenergic alpha-Antagonists↗
Failure of single night-time dose of H2-receptor antagonists in the treatment of duodenal ulcer patients with bulbar stenosis.
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Adult↗
Chronic administration of ketanserin and the development of two-kidney-two-clip Goldblatt renovascular hypertension in the rat.
The effect of ketanserin (Kt) has been analyzed during the development of two-kidney-two-clip (2k-2c) renovascular hypertension in the rat. Male Wistar rats were divided into four experimental groups: (1) clip Kt (ClKt) (n = 12)--A silver clip (0.25 mm width) was placed in each renal artery 3 days after beginning the administration of Kt (10 mg/kg/day) in the drinking water; (2) sham Kt (ShKt) (n = 13)--Similar to group 1, but the clips were placed in, and immediately removed from, the renal arteries; (3) untreated clip (UCl) (n = 10)--Similar to group 1, but the rats drank water; (4) untreated sham (USh) (n = 10)--Similar to group 2, but the rats drank water. Blood pressure (BP) was measured before surgery and was followed weekly for 7 weeks. At the end of this period, blood and cerebrospinal fluid (CSF) samples were obtained in all the animals. Plasma renin activity (PRA) and plasma and CSF angiotensinogen concentration (AoC) were evaluated. The results have shown that Kt partially inhibited the increase in BP induced by bilateral renal ischemia (BP: UCl rats 180.5 +/- 12.4 versus ClKt rats 149.8 +/- 5.1 mm Hg; p less than 0.01; USh rats 116.7 +/- 3.7; ShKt rats 114.4 +/- 5.0 mm Hg). PRA was similar in hypertensive and control rats whether or not they had received Kt. AoC in plasma was decreased in clipped treated and untreated rats.(ABSTRACT TRUNCATED AT 250 WORDS)
Angiotensinogen↗
Changes in the renin-angiotensin-aldosterone system in rats of both sexes submitted to chronic hypobaric hypoxia.
The effect of moderate chronic hypobaric hypoxia (CHH) on the renin-angiotensin-aldosterone system has been analysed in male and female intact and castrated rats. The experimental animals were submitted to a simulated altitude of 4,400 m during ten weeks. Half of the experimental and half of the control animals were castrated at three weeks of age. Arterial pressure (AP) was measured once a week during the whole experimental period. Blood samples were obtained by decapitation at the end of the study. Red cell volume, plasma renin activity (PRA), plasma angiotensinogen (Ao) and aldosterone concentration (ALDO) were determined in the blood samples. Results have shown that the female animals subjected to CHH had lower levels of AP than the control female rats during all the studied periods whereas the AP of male hypoxic rats was only transiently diminished. All these changes were abolished by castration. PRA was not altered in either sex. The enzymatic complex was higher in male than in female control animals and decreased after castration in both hypoxic and control male rats. Ao was decreased by CHH in both sexes of intact rats and in female castrated animals. The renin substrate was higher in male than in female intact rats and decreased after castration in male animals. ALDO was increased after CHH only in male rats. Control female rats have higher levels of ALDO than male animals. Changes in the renin-angiotensin-aldosterone system related to CHH and also significant differences between sexes suggest that adrenal and gonadal corticosteroids may be involved in the main alterations presently observed.
Aldosterone↗
Effect of somatostatin on prostaglandin E2 gastric intraluminal release in humans.
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Adult↗
Ranitidine and somatostatin. Their effects on bleeding from the upper gastrointestinal tract.
In a randomized, double-blind placebo-controlled clinical trial, the effect of ranitidine was compared with the effect of somatostatin in the control of massive gastrointestinal tract bleeding. Ninety-six patients completed the study. Rates of continuing bleeding and death, incidence of surgery, and blood transfusion requirements were not significantly different in the three treatment groups. Eighteen of the 96 patients presented with a visible vessel at endoscopy. In this group the percent of patients with continuing bleeding, mean transfusion requirements, and mortality were significantly higher than in patients without a visible vessel. Seven patients with a visible vessel underwent surgery and six survived; 11 patients underwent conservative measures and eight died. Ranitidine and somatostatin do not seem to alter the clinical course of patients with upper gastrointestinal tract hemorrhage.
Adult↗
Vascular renin-like activity in aorta and mesenteric artery of the rat.
Vascular renin-like enzymatic activity (VRLA) has been measured in the artery wall of control and experimental rats. The following groups have been studied: 1-normal salt diet; 2-high salt diet; 3-low salt diet; 4-bilateral nephrectomy (Nx); 5-sham operated for Nx. VRLA was evaluated in the aorta (ARLA) and in the mesenteric arteries (MRLA). Blood samples were obtained for plasma renin activity (PRA) determination. High salt diet decreased PRA, ARLA and MRLA whereas low salt diet increased PRA, did not change ARLA and decreased MRLA. PRA was almost undetectable in Nx animals while ARLA showed a 40% reduction and MRLA was unchanged in these animals. These results would indicate that the changes in PRA induced different variations in the renin-like content of the aorta and the mesenteric artery. The differences could be mainly due to two factors: 1) the capacity of the vascular tissue to bind circulating renin and 2) the capacity of each tissue to synthetize renin-like material in situ.
Animals↗