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At least 109 records · Page 6Linked to original sources
PubMed2002

The influence of pylorus-preserving partial gastrectomy on carcinogenesis of residual gastric mucosa in the rat.

PURPOSE: The aim of this study is to investigate a pylorus- and vagus-nerve-preserving partial gastrectomy to discover any correlation to a reduced carcinoma occurrence from residual gastric mucosa. METHODS: Wistar rats underwent a distal partial gastrectomy (Group D), a pylorus-preserving partial gastrectomy (Group P), or a simple laparotomy (as a control) (Group C) while some also underwent an additional truncal vagotomy (Groups DV, PV, and CV). Continuous per oral administration of N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) was given every day for 8 weeks before operation. At 3, 6, and 12 months after surgery, the animals in each group were administered an intraperitoneal injection of bromodeoxyuridine (BrdU). At 1 h after injection, the animal was killed, and the residual stomach removed. RESULTS: The histopathological findings showed no intestinal metaplasia and no gastric cancer in any group. No abnormality in the gastric mucosa was found in either Group C or Group CV. However, anastomotic ulcers, cystic glands, and submucosal gland formation were found significantly more in Groups P and in PV than in either Groups D or DV (each P < 0.05). Atypical glands were found in only one rat in each of Groups D and DV, and gastritis cystica polyposa (GCP) was found in only one rat in Group DV. All of these findings occurred in the fundic gland mucosa on the oral side of the anastomosis. The BrdU labeling index in this fundic gland mucosa was significantly higher in Groups D and DV than that in Groups C and CV, at 3, 6, and 12 months postoperatively (P < 0.05). The pH of the gastric juice was higher in all those groups that underwent vagotomy, with a significant difference only between Groups DV and C (P < 0.05). The concentration of bile acids contained in the gastric juice (microM/l) was significantly lower in Groups P and PV than that in Groups D or DV (each P < 0.05). CONCLUSION: The preservation of the pylorus was considered to be a useful surgical method to prevent the retrograde reflux of the duodenal juice into the residual stomach, and also reduced the proliferative activity of the residual gastric mucosa on the oral side of the anastomosis.

Animals↗
PubMed1985

A continuous manometric study of the human pylorus.

Previous manometric studies of the pylorus in humans have yielded conflicting data. These interstudy variations may be the result of differences in technique. It is also possible that pyloric pressure shows cyclic variations with the interdigestive motility complex. Pyloric pressure was monitored continuously for 300 min in 6 healthy men by means of a Dent sleeve. Gastroduodenal activity was measured simultaneously by using a perfused catheter system with two antral and two duodenal ports. With this method the pylorus was shown to have no elevation in basal pressure above baseline duodenal pressure during phase III. Basal pyloric pressure varied between subjects in phases I and II, being elevated in some but not in others. Subjects restudied on a separate day often showed a different pattern of activity. Pyloric pressure increased gradually in response to duodenal acidification. This response was blocked by pretreatment with naloxone. The pylorus also showed phasic activity, which was maximal in phase III. This phasic activity could not be distinguished from that of the adjacent antrum and duodenum. In conclusion, pyloric pressure patterns showed marked variation within and between subjects. These variations may explain some of the differences between previous studies.

Adult↗
PubMed1989

Neural reflex of the canine pylorus to intraduodenal acid infusion.

In 29 chloralose-urethane anesthetized dogs, a manometric assembly was inserted through a gastrostomy to monitor pressure of the pyloric region with a sleeve sensor. Antral and duodenal contractions were monitored with both manometric sideholes and serosal strain gauges. An additional tube channel allowed intraduodenal infusions 1-2 cm aborad from the pylorus. Intraluminal infusion of hydrochloric acid (0.1 N, 0.92 ml/min, for 2 min) reproducibly caused activation of motor activity in the pyloric region and peristaltic duodenal activity. Proximal duodenal activity probably contributed to the total phasic response recorded in the pylorus region. Excitatory responses could also be elicited by infusion of phenyl-biguanide (stimulant of sensory nerve endings), but not by control infusions with diluent (Krebs' buffer or saline). The motor response of the pyloric region to intraduodenal acid was blocked by intraduodenal application of 2% xylocaine. Atropine (30 micrograms/kg i.v. and 100 micrograms i.a.) or hexamethonium (10 mg/kg and 1 mg i.a.) markedly reduced or blocked the acid-induced pyloric motor response of this region but propranolol (1.0 mg/kg i.v. and 100 micrograms i.a.), phentolamine (1.5 mg/kg i.v. and 100 micrograms i.a.), or naloxone (200 micrograms/kg and 20 micrograms i.a.) had no effect. We believe these observations show the existence of a reflex from the duodenum to the pylorus in response to intraluminal stimuli mediated by a chain of cholinergic nerves. In the dog, endogenous opioid peptides do not contribute to the excitatory reflex pathway activated by intraduodenal acid or phenyl-biguanide. As intraluminal acid in the duodenum activates this reflex, it may play a role in the physiologic and pathophysiologic role of gastric emptying in this species.

Anesthesia, Local↗
PubMed1992

Pancreatoduodenectomy with preservation of the stomach and pylorus: a safe and effective alternative in children.

The time-honored surgical approach to resectable tumors of the head of the pancreas or distal common bile duct has been a Whipple operation for adults and children. In recent years, pylorus-preserving pancreatoduodenectomy has been used for adults. The postoperative physiological advantages may be enhanced in children, and for this reason the pylorus-sparing approach was used in a 15-year-old girl with a tumor of the distal common duct. The pylorus-preserving pancreatoduodenectomy was safe and effective in this patient and should be considered for children with resectable tumors of the distal common bile duct and pancreatic head.

Adolescent↗
PubMedDate not supplied

The actions of neurokinins and substance P in canine pylorus, antrum and duodenum.

Analogues highly selective for receptors for substance P [beta-Ala4,Sar9,Met(02)11]-SP(4-11), for neurokinin A, [Nle10]-NKA(4-10), and for neurokinin B, [beta-Asp4,MePhe7]-NKB(4-10), were administered intraarterially before and after atropine or tetrodotoxin, to characterize the locations on nerve and muscle of the different receptor subtypes in the canine antrum, pylorus and duodenum. Circular muscle strips from each region were also studied in vitro. The NK-2 receptors in the antrum and the pylorus were located postsynaptically on smooth muscle. The NK-3 receptors, on the other hand, were located on neuronal sites in the antrum and duodenum. NK-1 receptors were located on neuronal and nonneuronal sites in the antrum, pylorus and duodenum. Only nonneural receptors could be activated in vitro.

Animals↗
PubMed1995

CGRP antagonists enhance gastric acid secretion in 2-h pylorus-ligated rats.

The influence of calcitonin gene-related peptide (CGRP) antagonists on gastric acid secretion was investigated in rats. Intravenous injection of the CGRP receptor antagonist, CGRP(8-37) (128 nmol/kg) or the CGRP antibody #4901 (4.8 mg/kg, IV) completely prevented alpha-CGRP (3.9 nmol/kg/h)-induced inhibition of acid response to pentagastrin in urethane-anesthetized rats with gastric fistula. CGRP antibody (4.8 mg/kg, IV) increased by 93% gastric acid secretion in conscious rats with pylorus ligation for 2 h. (CGRP(8-73) (128 nmol/kg, IV) also enhanced the acid response measured 2 h after pylorus ligation in conscious rats and in urethane-anesthetized rats infused with pentagastrin by 91% and 56%, respectively. These results suggest that endogenous CGRP attenuates the gastric acid response measured 2 h after pylorus ligation.

Anesthesia↗
PubMed1993

Gastric lesion development in normal and pylorus ligated rats after cervical vagotomy.

The main purpose of this study was to further investigate the effects of vagotomy on gastric lesion development. In contrast to the usual subdiaphragmal vagotomy, a different vagotomy at the level of the trigonum caroticum was used both alone and in combination with pylorus ligation (done immediately after vagal transection). The animals were killed 15 min, 30 min, 1 h and 6 h following vagotomy. No damaging effects of sham-vagotomy, or obvious negative effects of cervical vagotomy were noted. Prominent lesions appeared after 1 h in rats subjected to cervical vagotomy and significantly increased lesions in the early period of pylorus ligation were noted. No further aggravation in pylorus ligated rats (even an apparent amelioration at 1-h interval) and no lesions in rats with cervical vagotomy in the latter period could be explained in terms of a lack of reactivity due to exhaustion preceding fatal outcome. Consistent with this, the rats subjected to cervical vagotomy died shortly after the 6-h period.

Animals↗
PubMed2002

[Cephalic pancreaticoduodenectomy for adenocarcinoma of the head of the pancreas: does pylorus preservation change morbidity and prognosis?].

STUDY AIM: To evaluate the influence of a pylorus-preserving on the morbidity and prognosis of patient with pancreaticoduodenectomy for adenocarcinoma of pancreas. PATIENTS AND METHODS: Between 1985 and 1999, 183 patients were operated on for pancreatic adenocarcinoma. Among them, 63 patients (40 men, mean age 63 years, range 41-77 years) had curative resection and were included in this retrospective study. They were classified according to the type of resection. In the group I, the procedure included a pylorus-preserving pancreaticoduodenectomy (n = 35). In the group II, the procedure included polar inferior gastrectomy (n = 28). The prognosis was compared. Parameters for comparison were rate of local recurrence, rate of metastatic evolution and duration of survival. RESULTS: The operative length and mortality rate (group I: 0%, group II: 3%), general (p = 0.37) and specific morbidity (p = 0.30), frequency of delayed gastric emptying were similar in the 2 groups (group I: 20%, group II: 35%, p = 0.88). The duration of naso-gastic aspiration was shorter in the group I (6 days vs 8, p = 0.01). The prognosis was the same in the 2 groups (metastasis: group I: 39%, group II: 56%, p = 0.12, local recurrence: group I: 58%, group II: 43%, p = 0.09, mean survival: group I: 18 months, group II: 19 months, p = 0.77). CONCLUSION: These results suggest that pylorus preserving pancreatoduodenectomy could be performed for patients with adenocarcinoma of the head of the pancreas and does not compromise survival.

Adenocarcinoma↗
PubMed1998

The ontogeny of innervation of the human pylorus.

PURPOSE: The aim of this study was to document the vagal innervation and expression of neuropeptides, neuronal nitric oxide synthase (nNOS), and neural cell adhesion molecule (NCAM) in the neuromuscular system of the developing human pylorus. METHODS: Specimens of human pylorus (n = 54; age range, 8 weeks' gestation to 6 months postnatal) were studied. Vagal innervation was determined by Dil autofluorescence. A wide range of neuropeptides, NCAM, and the neural isoform of NOS were examined by immunohistochemistry. RESULTS: Vagal innervation was first recognized in the myenteric plexus in the 12-week-old fetus as was vasoactive intestinal polypeptide (VIP) expression. Neuropeptides were present from 8 weeks' gestation and appeared to be expressed progressively from the adventitia toward the mucosa and showed an adultlike profile by 23 weeks' gestation. A craniocaudal pattern of expression was noted for VIP and nNOS. Alpha smooth muscle actin was expressed by muscle fibers of the muscularis propria from 8 weeks and the muscularis mucosae by 14 weeks. All the isoforms of NCAM examined were expressed from 8 weeks in the muscularis propria and by 12 weeks in the submucosa. CONCLUSION: The expression of the antigens studied correlated with the gestational age and development of the pylorus.

Embryonic and Fetal Development↗
PubMed1999

Interposition of a jejunal segment between esophagus and pylorus for treatment of multirecurrent gastroesophageal reflux.

Here the authors report the clinical experience with placement of an isolated jejunal segment between the esophagus and pylorus for treatment of multirecurrent gastroesophageal reflux (GER) in a child. A 6-year-old neurologically normal girl experienced severe symptomatic GER after 3 previous well-constructed Nissen fundoplications that failed over a 4-year period. The gastric cardia was closed, and a 16-cm isolated segment of proximal jejunum was placed in an isoperistaltic direction between the distal esophagus and an incision through the pylorus, extending onto both the antrum and duodenum. A gastrostomy was used for 3 months. The patient recovered from the operation without complications and has been completely relieved of reflux symptoms during the 15 months postoperation. She has gained over 6.5 kg in weight and 3.2 cm in height during this period and has not experienced difficulty swallowing solid foods. Esophagogastric dissociation with placement of an isolated jejunal segment between the esophagus and pylorus may have a useful role in the surgical management of multirecurrent symptomatic GER as a "rescue procedure" with low risk compared with other options.

Anastomosis, Surgical↗
PubMed1998

Closing the pylorus decreases the size of large meals in the rat.

We previously reported (Davis, J. D.; Smith G. P.; Sayler, J. L. Reduction of intake in the rat due to gastric filling. Am. J. Physiol. 272:R1599-R1605, 1997.) that confining ingested fluid to the stomach by closing the pylorus decreased the intake of solutions that stimulated particularly large intakes. Those solutions differed in the type of orosensory and postoral stimulation so the nature of the control over ingestion was unclear. We report here a study of the role of orosensory stimulation alone in controlling intake in rats with a closed pylorus. Rats were given 30-min intake tests with the pylorus open and closed with 0.2 M glucose, and with 0.2 M glucose + 1.25 mM sodium saccharin, 2.5 mM sodium saccharin and 5.0 mM sodium saccharin. Intake was reduced on the cuff-closed test relative to the cuff-open test with the two highest concentrations of saccharin, but not with the two lowest. When ingesting the glucose solutions with the two highest concentrations of saccharin the initial rate of ingestion was greater and the decline in the rate of ingestion was slower than when the rats ingested the glucose solutions with 1.25 mM saccharin or no saccharin. We showed by means of a meta-analysis of previously published and unpublished data that a high rate of licking at the beginning of a test combined with a relatively slow rate of decline in the rate of licking during it are the characteristics of ingestive behavior on cuff-open tests that will lead to a reduction of intake when ingested fluid is confined to the stomach.

Animals↗
PubMed2003

Erythromycin induces pyloric relaxation accompanied by a contraction of the gastric body after pylorus-preserving gastrectomy.

BACKGROUND: Pylorus-preserving gastrectomy (PPG) is a function-preserving surgery; however, long-term retention of food in the residual stomach is a frequent complication during the early postoperative period. We reported that gastric stasis after PPG was attributable to the delayed recovery of gastric phase III, in which pyloric relaxation accompanied a contraction of the gastric body. The objective of the present study is to determine whether erythromycin can induce phase III with pyloric relaxation after PPG. METHODS: We studied gastrointestinal motility in dogs after PPG by using strain gauge force transducer. After randomized administration of either erythromycin or saline, interdigestive gastropyloroduodenal motility was recorded. RESULTS: Erythromycin induced phase III with pyloric relaxation in the early postoperative period. Pyloric relaxation accompanied a contraction of the gastric body. Compared with the saline group (body: 87.2 +/- 16.7 mmHg x min, antrum: 69.7 +/- 13.7 mmHg x min, pylorus: 91.7 +/- 22.1 mmHg x min), the erythromycin group showed significantly increased gastropyloric motility indexes (body: 506.2 +/- 33.5 mmHg x min, antrum: 430.9 +/- 53.7 mmHg x min, pylorus: 589.5 +/- 59.5 mmHg x min). CONCLUSIONS: Erythromycin can induce phase III, in which pyloric relaxation accompanied a contraction of the gastric body in the early postoperative period after PPG. Erythromycin might be used as a prokinetic agent for the treatment of early gastric stasis after PPG.

Animals↗
PubMed1996

Pancreatoduodenectomy with preservation of the pylorus and gastroduodenal artery.

OBJECTIVE: The authors evaluated the rationale for and feasibility of gastroduodenal artery preservation in pylorus-preserving pancreatoduodenectomy (PPPD) for periampullary cancer in which the pancreatic remnant maintains a normal function and morphologic characteristics. SUMMARY BACKGROUND DATA: Pylorus-preserving pancreatoduodenectomy has become one of the standard treatments used for benign and malignant diseases of the pancreatoduodenal region, surpassing ordinary pancreatoduodenectomy in terms of technical ease, mortality rate, and postoperative nutrition. Pylorus-preserving pancreatoduodenectomy is usually associated with gastroduodenal artery division, which presents potential risks of insufficient duodenal vascularity and lethal postoperative bleeding from the gastroduodenal artery stump. The latter complication particularly occurs after resection of bile duct or ampullary cancer in a patient whose pancreas remains functionally and morphologically normal to have much more pancreatic secretion than the fibrotic pancreas seen in pancreatic cancer. According to the authors data on the volume of secretion from the residual pancreas via a stent tube after pancreatoduodenectomy, the sclerotic pancreas, as seen in cancer of the pancreatic head, secrets only 20 to 50 mL/day, whereas the secretion from the soft pancreas, as seen in bile duct cancer, amounts to 300 to 600 mL/day, even during the period of nothing by mouth. METHODS: Retrospectively, we made a histopathologic study of eight specimens of distal bile duct and ampullary cancer resected by pancreatoduodenectomy or PPPD with gastroduodenal artery division. Prospectively, we performed gastroduodenal artery- preserving PPPD for 10 patients with distal bile duct, ampullary, and islet cell cancers. RESULTS: The histopathologic study revealed no invasion or metastasis around the gastroduodenal artery. Clinical application of gastroduodenal artery-preserving PPPD showed no technical difficulty, and neither severe complications nor recurrence around the gastroduodenal artery were observed for up to 22 months after surgery. CONCLUSIONS: Gastroduodenal artery- preserving PPPD might be recommended as a safe procedure for patients who have a functionally and morphologically normal pancreas.

Aged↗
PubMed1995

R-alpha-methylhistamine-induced inhibition of gastric acid secretion in pylorus-ligated rats via central histamine H3 receptors.

1. The effect of central H3 histamine receptor activation on gastric acid and pepsin production has been investigated in pylorus-ligated rats. 2. Intracerebroventricular injections (i.c.v.) of the selective H3 agonist, R-alpha-methylhistamine (0.5-50 nmol per rat) caused a dose-dependent inhibition of gastric acid secretion while intravenous administration (5-500 nmol per rat) was completely ineffective. 3. I.c.v. microinjections of mepyramine, tiotidine and thioperamide (51 nmol per rat), selective antagonists at H1-, H2- and H3-sites respectively, failed to modify the acid secretory response to pylorus ligation. 4. The antisecretory effect of R-alpha-methylhistamine (5 nmol per rat, i.c.v.) was selectively prevented by the H3-blocker, thioperamide (51 nmol per rat, i.c.v.), mepyramine and tiotidine pretreatment being completely inactive. 5. Unlike acid secretion, pepsin production was not significantly affected by all the tested compounds. 6. These findings provide the first pharmacological evidence that the activation of central H3 histamine receptors exerts a negative control in the regulation of gastric acid secretion in conscious pylorus-ligated rats.

Animals↗
PubMed1979

Vagus nerves and the gastric tissue histamine concentration in pylorus ligated albino rats.

Gastric tissue histamine concentration was determined, 6 and 16 hours after pylorus ligation in vagus intact and vagotomized albino rats and the results were compared with those of respective control animals, sacrificed, 6 and 16 hours after ether anaesthesia alone. The gastric tissue histamine concentration of rats subjected to none of the experimental situations was also determined and taken into comparison. The results show that the stress of pylorus ligation reduced the gastric tissue histamine concentration, the reduction being more with increased duration of stress. On the other hand, subdiaphragmatic vagtomy preserved the histamine concentration of gastric tissue irrespective of the duration to which the animals were exposed following pylorus ligation. It appears that increase in vagal discharges during stress leads to increased liberation of histamine from the gastric wall, thereby, reducing the gastric tissue histamine concentration; the reduction being proportional to the duration of stress and increase in vagal discharges, whereas, in the absence of vagal impulses following subdiaphragmatic vagotomy, the gastric tissue histamine concentration is preserved in spite of the stress to which the animals were exposed.

Animals↗
PubMed1992

Innervation of pylorus in control of motility and gastric emptying.

The motility index (MI) and contractile frequency were determined for the gastric antrum, pylorus, and duodenum during digestive and interdigestive states in eight dogs before and after resection of the ramus pyloricus nervi vagi (NR) and after selective proximal vagotomy (SPV) subsequent to NR. Neither NR nor subsequent SPV altered the migrating motor complex in the interdigestive state. In the digestive state, NR decreased the MI in the antrum, pylorus, and duodenum. The MI did not further change after SPV subsequent to NR. The cholecystokinin antagonist L364,718 decreased MI in the antrum, pylorus, and duodenum. After NR, L364,718 caused a further reduction in the MI during administration. Gastric emptying was accelerated after NR. SPV subsequent to NR increased gastric emptying further. L364,718, in the absence of NR, accelerated gastric emptying but only during the initial period of emptying. After NR, L364,718 also decreased the time required for emptying of 50 and 100% of the meal. After SPV subsequent to NR, no additional acceleration of emptying occurred.

Animals↗
PubMed2000

Nitrergic and purinergic regulation of the rat pylorus.

The role of nitric oxide (NO) and ATP in the regulation of nonadrenergic, noncholinergic (NANC) inhibitory transmission in the pylorus remains unclear. In the presence of atropine and guanethidine, electric field stimulation induced NANC relaxations in a frequency-dependent manner (1-20 Hz) in the rat pylorus. NANC relaxations were significantly inhibited by N(G)-nitro-L-arginine methyl ester (L-NAME; 10(-4) M). P(2X) purinoceptor antagonist pyridoxal phosphate-6-azophenyl-2',4'-disulfonic acid (PPADS; 3 x 10(-5) M) and P(2Y) purinoceptor antagonist reactive blue 2 (2 x 10(-5) M) had no effect on NANC relaxations. However, the combined administration of L-NAME and PPADS, but not reactive blue 2, evoked greater inhibitory effects on NANC relaxation than that evoked by L-NAME alone. alpha-Chymotrypsin and vasoactive intestinal polypeptide antagonist did not affect NANC relaxations. ATP (10(-5)-10(-3) M) and P(2X) purinoceptor agonist alpha, beta-methyleneadenosine 5'-triphosphate (10(-7)-10(-5) M), but not P(2Y) purinoceptor agonist 2-methylthioadenosine 5'-triphosphate (10(-7)-10(-5) M), induced muscle relaxations in a dose-dependent manner, and relaxations were significantly reduced by PPADS and unaffected by TTX. These studies suggest that NO and ATP act in concert to mediate NANC relaxation of the rat pylorus. ATP-induced relaxation appears to be mediated by P(2X) purinoceptors located on smooth muscle cells.

Adenosine Triphosphate↗
PubMed1991

Pylorus-preserving pancreatoduodenectomy. Experience in 20 patients.

Twenty patients underwent a pylorus-preserving pancreatoduodenectomy for benign or malignant periampullary and pancreatic disease. Eighteen patients had a partial and two patients a total pancreatectomy. There were 19 elective and 1 emergency operations. Post-operative mortality was 4% (1/20 patients) and the median follow up was 31 months (range, 15-75 months), during which period 8 patients with a malignant disease died. Pylorus-preserving pancreatoduodenectomy did not compromise survival in ampullary cancer. One patient developed a marginal ulcer during the study period and one of twelve patients, examined by technetium scintigraphy (done more than 3 months after the procedure), had delayed gastric emptying. Two patients presented with a gastric retention as the first sign of recurrent pancreatic cancer. The result of the operation was judged as excellent in 7 patients, good in 8 and as bad in only 2 of the 17 patients who survived more than 6 months. Body weight was studied in 15 patients surviving more than one year after operation; five patients had gained weight, two had lost weight and in 8 there was no difference. Pylorus-preserving pancreatoduodenectomy seems to be a valuable alternative in the treatment of patients with benign and selected malignant pancreaticobiliary disease.

Adult↗