Role of metalloproteinases in the development and healing of acetic acid-induced gastric ulcer in rats

The three main components involved in thrombosis and haemostasis are thrombin, platelets, and plasmin. Almost all inhibitors of thrombosis are focused either on the inhibition of thrombin or on the inhibition of platelets. We designed a construct using the fibrinolytic activity of staphylokinase, fused via a cleavable linker to an antithrombotic peptide of 29 amino acids. The peptide was designed to include three inhibitory regions: (1) the Arg-Gly-Asp (RGD) amino acid sequence to prevent fibrinogen binding to platelets; (2) a part of fibrinopeptide A, an inhibitor of thrombin; and (3) the tail of hirudin, a potent direct antithrombin. The amino acid sequence of the 29 amino acid peptide was reverse translated, and the gene was chemically synthesised and cloned into an expression vector as a 3' fusion to the staphylokinase gene. Gene expression was induced in E. coli Top 10 cells and the fusion protein, designated PLATSAK, was purified using metal affinity chromatography. The purified fusion protein significantly lengthened the activated partial thromboplastin time and thrombin time and inhibited the amidolytic activity of thrombin. The fibrinolytic activity was almost equal to that of recombinant staphylokinase as measured with a thrombelastograph. Platelet aggregation was not markedly inhibited by PLATSAK, probably due to the unfavourable three dimensional structure, with the Arg-Gly-Asp sequence buried inside. Our results confirm that it is feasible to design and produce a hybrid multifunctional protein that targets various components of the haemostatic process.     

Evaluation of the clinical impact of endoscopic ultrasonography in gastrointestinal disease

A total of 120 gastro-intestinal tracts and 960 faecal samples were examined to assess the prevalence and seasonal changes in the gastro-intestinal helminth parasites of Red Sokoto (maradi) goats slaughtered at Ibadan between May 1991 and April 1992. Egg types of strongyles, Strongyloides, Trichuris, Skrjabinema, Dicrocoelium and Moniezia were encountered in 93%, 83%, 44%, 0.9%, 2.3% and 31% of the faecal samples respectively. However, only strongyle, Strongyloides and Trichuris eggs occurred in large numbers and were more common during the rainy season than in the dry season. The parasites recorded and their prevalences were Haemonchus contortus (90.0%), H. ovis (5.0%), Strongyloides papillosus (80.8%), Trichostrongylus colubriformis (78.3%), T. axei (69.2%), Trichuris ovis (72.5%), T. globulosa (38.3%), Oesophagostomum columbianum (67.5%), Cooperia curticei (58.3%) Gaigeria pachyscelis (40.8%), Skrjabinema ovis (5.0%), Nematodirus battus (5.8%), Moniezia expansa (29.2%), M. benedeni (10.0%), Paramphistomum spp. (5.0%) and Cysticercus tenuicollis (33.3%). Haemonchus ovis is reported for the first time in Nigeria. Mixed infections were most prevalent. Young goats were more commonly infected and had higher worm counts than adult goats. Only Haemonchus, Trichostrongylus, Strongyloides and Cooperia spp. occurred in large numbers. Irrespective of the age of the goats, higher worm counts were generally encountered during the rainy season than in the dry season. The results are discussed in relation to the control of helminthiasis in grazing animals in Nigeria.     

Accuracy of endoscopic ultrasonography in the diagnosis and staging of gastric cancer and lymphoma

BACKGROUND: There is a need to assess the sensitivity, specificity, and predictive value of endoscopic ultrasonography (EUS) in the diagnosis and staging of gastric cancer and lymphoma. METHODS: A prospective study was performed on 86 patients with endoscopic gross appearance suspicious for cancer or lymphoma. Biopsies with endoscopic forceps were always carried out before EUS. All patients underwent laparotomy for final diagnosis, staging, and eventually treatment. The results of EUS were correlated with the histologic findings of the resected specimens, when possible, or with the surgical findings. There were 42 gastric cancers and 44 primary gastric lymphomas. RESULTS: EUS made a correct diagnosis of cancer in 35 of 42 patients, with a sensitivity of 83%. Positive predictability was 87%, specificity was 97%, and negative predictability was 96%. Diagnostic accuracy was 95%. In the evaluation of cancer depth invasion, EUS was correct in 91% of cases. EUS displayed perigastric metastatic lymph nodes in 14 of 25 patients, with a sensitivity of 56%. Positive predictive value was 93%, specificity was 93%, and negative predictive value was 54%. Diagnostic accuracy was 69%. EUS made a correct diagnosis of lymphoma in 39 of 44 patients, with a sensitivity of 89%. Positive predictability was 87%, specificity was 97%, and negative predictability was 97%. Diagnostic accuracy was 95%. In the evaluation of lymphoma depth invasion, EUS was correct in 92% of cases. EUS displayed metastatic perigastric lymph nodes in 8 of 18 patients, with a sensitivity of 44%. Positive predictability was 100%, specificity was 100%, and negative predictability was 72%. Diagnostic accuracy was 77%. CONCLUSIONS: From these data it appears that in these diseases EUS has demonstrated specific ultrasonographic features that allow correct diagnosis and staging in the majority of patients. In difficult cases EUS may help to achieve the correct diagnosis. EUS also appear to be a useful tool for staging of gastric cancer and lymphoma. It shows not only tumor depth and local spread but also the passage from a pathologic to a normal wall and lymph node metastasis. With this accurate noninvasive staging procedure, in the near future many patients will no longer undergo exploratory laparotomy for surgical staging. Thanks to EUS, the choice of conservative or surgical treatment can be strongly affected. In case of surgery, EUS can orient the kind of surgical approach. Moreover, the use of EUS for evaluation of therapy during follow-up will probably become of major importance.     

Malabsorption of zinc in rats with acetic acid-induced enteritis and colitis

Acute intestinal inflammation was established in rats by intraluminal administration of acetic acid into loops of distal ileum, proximal jejunum or ascending colon. The study included two control groups of intact (untreated) rats and sham-operated (saline-treated) rats for each intestinal segment. A third group of rats received acetic acid. Histological evaluation demonstrated that acetic acid treatment induced a mild inflammatory response. Two days after treatment, zinc absorption was measured using ligated 10-cm loops of each segment in which 65Zn was injected intraluminally. 65Zn absorption by the ileum, jejunum and colon was markedly reduced in those rats in which inflammation was induced by acetic acid. The liver showed the highest uptake of radioisotope, but the relative tissue distribution generally followed the amount of absorption. The surgical procedure itself seemed to reduce zinc absorption. No changes in [3H]leucine absorption were observed between sham-operated and acetic acid-treated controls. There was no significant serosal-->luminal secretion of intramuscularly injected 65Zn in any of the studied segments. Therefore, based upon the data obtained, we conclude that acetic acid-induced intestinal inflammation reduces absorption of zinc by the small and large intestine, and that a surgical procedure (laparotomy) also reduces zinc absorption. The mechanism of this inflammation is such that malabsorption shows some specificity.     

Effect of preinduction of heat-shock proteins on acetic acid-induced small intestinal lesions in rats

Bowel dysfunction such as irritable bowel syndrome caused by stress is well described. Previous reports suggest that stress is known to cause the release of endogenous substances such as catecholamine, beta-endorphine, 5-hydroxytryptamine, corticotropin-releasing factor, and thyrotropin-releasing hormone (TRH). However, the role played by these neurohormonal mediators in bowel dysfunction under stress conditions is not well known. We investigated the influence of water-immersion stress or TRH administration on the expression of 60-kDa, 72-kDa, and 90-kDa heat-shock proteins (HSP60, HSP72, and HSP90, respectively) in rat small intestinal mucosa by Western blot and immunohistochemical analyses. The cytoprotective function of preinduced HSPs on experimentally induced mucosal damage also was studied. In order to investigate the influence of preinduction of HSP60 on small intestinal damage, the small intestinal lumen was perfused with 1.5% acetic acid 1 ml/min for 15 min with or without pretreatment with water-immersion stress or TRH administration. Expression of HSP60 was significantly increased by water-immersion stress or TRH administration in the small intestinal mucosa, whereas HSP72 and HSP90 did not increase. Interestingly, expression of this protein showed the biphasic peak pattern after water-immersion stress or TRH administration. Each peak was observed 3-6 hr and 21-24 hr after the initiation of water-immersion stress or TRH administration. Immunohistochemical study also showed a significant increment of HSP60 in both the cytoplasm and nuclei of the small intestinal mucosal cells. No histopathologic alteration was observed in rat small intestinal mucosa after each treatment. Small intestinal damage caused by 1.5% acetic acid perfusion was not influenced by preinduction of HSP60. We demonstrated that water-immersion stress or TRH administration specifically induced HSP60, although preinduction of this protein did not show a cytoprotective function in the small intestinal mucosa.     

Diagnosis of superficial-type early carcinoma of the gallbladder by endoscopic ultrasonography--comparison with ultrasonography

The detectability of superficial-type carcinoma of the gallbladder by ultrasonography (US) and endoscopic ultrasonography (EUS) were investigated. Eight patients with such carcinoma of the gallbladder were reviewed. They had undergone both US and EUS previous to surgery. The tumor was detected in 3 patients by US, 2 patients with IIa + IIb-type carcinoma and 1 patient with IIa-type carcinoma. Those lesions were visualized as localized thickening of the gallbladder wall or as broad-based tumor. In 2 patients, lesions were not initially detected by US, but were shown by US after the examination by EUS. The tumor was detected by EUS also in 1 case of IIb + IIa-type carcinoma besides those 3 patients mentioned above. All four of these lesions were visualized as broad-based tumor by EUS. It was difficult to detect pure IIb-type or small IIa-type carcinoma even by EUS. In patients with concomitant acute cholecystitis or gallbladder stone, it was difficult to evaluate the abnormal findings of the gallbladder wall.     

Effect of putative phospholipase A2 inhibitors on acetic acid-induced acute colitis in the rat

Phospholipase activation may play an important role in ulcerative colitis. This hypothesis was tested by evaluating the effect of two non-selective phospholipase (PL) A2 inhibitors, quinacrine and p-bromophenacyl-bromide (pBPB), on acetic acid-induced colitis in the rat. The calcium antagonist verapamil, which may also act as a PLA2 inhibitor, was also tested. Acute colitis was induced in an isolated colonic segment by instillation of 4 per cent acetic acid for 15 s; this induces a uniform colitis after 4 days. The severity of colitis was evaluated histologically, by measuring myeloperoxidase (MPO) activity and by determining plasma exudation into the lumen of the colon (permeability) with 125I-labelled albumin given intravenously. All three putative PLA2 inhibitors tested were found to prevent the development of colitis. Intravenous administration of quinacrine 10 mg kg-1 at 30 min before instillation of acetic acid resulted in a normal mucosal appearance, normal MPO activity and a significantly reduced increase in plasma exudation into the colon. A similar effect was achieved using verapamil. Intracolonic administration of either quinacrine or pBPB also prevented acetic acid-induced colitis. However, three doses, starting immediately after acetic acid administration and repeated on the first and second days, were needed to achieve this, whereas one dose produced only a partial effect. PLA2 may play an important role in acetic acid-induced colitis and inhibition of its activity may offer an alternative mode of treatment in ulcerative colitis.     

History of perforated duodenal and gastric ulcers

Perforated peptic ulcer as a disease entity has been known since 167 BC. Surgical and nonsurgical treatment strategies for perforated peptic ulcer disease were not developed until the latter half of the nineteenth century. The history of the gradual evolution of the various forms of treatment adopted for the conditions over the last century and a half is described.     

Hemorrhage from acute ulcers of gastric mucosa

The work analyses the results of management of 429 patients with acute erosive-ulcerative gastritis in a specialized department. The most frequent causes are duodeno- or enterogastric reflux (24.7%), abuse of alcohol (23.6%), medication with mucosa irritating drugs (22.5%). Particular attention is drawn to gastritis of a reflux character which is dangerous not only because of recurrent bleeding but also because of the possibility of structural reorganization of the gastric mucosa leading to development of carcinoma. Attention is focused on the errors in nonoperative and surgical treatment and the need for taking into consideration the etiopathogenesis of acute ulcers. In ulcerations of a reflux character it is recommended that after bleeding is arrested by conservative measures, an operation for removal of the reflux is performed in a planned order. In the other cases, in emergency situations, deep stitching of the erosions with vagotomy and pyloroplasty must be resorted to. The author considers acute ulcers of the stomach to be a precancer marker and believes it necessary to register all patients for regular medical control.     

Therapeutic indications in hemorrhaging duodenal and gastric ulcers

Ulcer complications including bleeding and perforation were increasingly observed during the last decade due to the greater life expectancy and the increased NSAID consumption. The unchanging mortality rate, which has been around 6-10% for several decades, could be explained by the fact that age and the prevalence of concurrent illness are important predictors of death. Rebleeding which is also an independent prognostic factor can be predicted by the presence of hypovolemic shock and of endoscopic stigmata such as active bleeding or a visible vessel. Endoscopic hemostatic therapy, specially injection therapy which is the most widely used method, has become the treatment of choice. It has been proven to significantly reduce rates of further bleeding, surgery and mortality. Surgical intervention is indicated in cases of immediate or secondary failure of endoscopic therapy (20%) and should not be delayed in high-risk patients. Once hemostasis has been achieved therapeutic goals are to heal the ulcer and to prevent the occurrence of further complications including bleeding and also perforation.     

Phosphatidylcholine-associated aspirin accelerates healing of gastric ulcers in rats

In this double-blind study, we administered lumbar epidural bupivacaine or bupivacaine plus verapamil to investigate the possible role of the calcium channel blocker, verapamil, in postoperative pain. One hundred patients (ASA physical class I or II) scheduled for lower abdominal surgery were randomly assigned to one of four groups. Group 1 received 10 mL of 0.5% epidural bupivacaine injected 15 min before incision, followed by 10 mL of epidural normal saline 30 min after incision. Group 2 received 10 mL of epidural normal saline injected before incision, followed by 10 mL of 0.5% epidural bupivacaine 30 min after incision. Group 3 received 10 mL of 0.5% epidural bupivacaine plus 5 mg of verapamil injected before incision, followed by 10 mL of epidural normal saline 30 min after incision. Group 4 received the same drugs as Group 3, in the reverse order. Pain and mood numeric rating scores, sedation scores, Prince Henry scores, patient-controlled cumulative postoperative analgesic consumption, and the incidence of side effects were assessed 2, 6, 12, 24, and 48 h after the operation in each group. Cumulative postoperative analgesic consumption in Groups 3 and 4 was significantly lower (P < 0.05) than that in Groups 1 and 2 24 and 48 h after surgery. There were no differences in the pain, mood, and sedation scores and the incidence of side effects among the four groups. We conclude that epidural verapamil decreases postoperative pain, possibly by interfering with normal sensory processing and by preventing the establishment of central sensitization. Implications: Calcium plays an important role in pain physiology at the spinal cord level. We examined the effect of bupivacaine plus verapamil (calcium channel blocker) and of bupivacaine alone. We demonstrated that the combination, administered epidurally, resulted in less postoperative analgesic consumption than bupivacaine alone.     

Colour duplex ultrasonography in the rational management of chronic venous leg ulcers

Colour duplex ultrasonographic imaging has largely replaced venography in the assessment of lower-limb venous disorders. This is a study of the use of duplex in the management of patients with chronic venous ulceration in community ulcer clinics. Patients with chronic leg ulceration and an ankle: brachial pressure index of 0.85 or greater were studied. Assessment of venous competence in both the deep and superficial systems of the affected and unaffected legs was performed using colour venous duplex imaging. Reflux was defined as reverse flow for greater than 1 s after manual calf compression. One hundred consecutive patients were assessed over 15 months. Of 111 ulcerated legs, 96 had active ulceration, while 15 had been ulcerated within the previous 6 months. Fifty-seven (51 per cent) of the 111 ulcerated legs had superficial incompetence alone (88 per cent long saphenous system or its perforators, 12 per cent short saphenous system). Six legs (5 per cent) had isolated deep venous incompetence. Forty-two legs had mixed superficial and deep venous reflux; 22 of these had undergone previous venous surgery. Colour venous duplex assessment demonstrated superficial venous disease in approximately half of limbs with chronic leg ulceration. Venous dysfunction in these patients is potentially curable by surgery.     

Use of endoscopic ultrasonography for evaluation of painless jaundice

Precise preoperative evaluation and staging of cases of painless jaundice is extremely important. Many of the patients are older and may have multiple medical problems that increase their operative risk. Assessment of the distal common bile duct, ampulla of Vater, and head of the pancreas is particularly difficult. Various imaging modalities are available but are not sensitive enough to detect small lesions or local invasion. Endoscopic ultrasonography is a new technique that places the transducer closer to the organ being evaluated, adding a new dimension to defining tumor invasion and extension.     

Short communication: detection of early scirrhous carcinoma of the stomach by endoscopic ultrasonography

The endoscopic ultrasonography (US) characteristics of early scirrhous carcinoma of the stomach (ESS) were evaluated in four patients. ESS was defined as the presence of poorly differentiated carcinoma cells spreading through the submucosa and muscularis propria in association with a marked desmoplastic reaction without serosal invasion. ESS was characterized by localized irregular hypoechoic enlargement of the third (submucosal) and the fourth (muscularis propria) layers. The fifth (serosal) layer was normal. The third and fourth layers showed a threefold increase in thickness compared with the thickness of these layers in healthy subjects. Our results suggest that endoscopic US is useful for diagnosis of ESS.     

Contrast-enhanced endoscopic ultrasonography in pancreatic diseases: a preliminary study

OBJECTIVE: The purpose of this study was to clarify the usefulness of contrast-enhanced endoscopic ultrasonography in pancreatic diseases. METHODS: The subjects comprised 37 patients with pancreatic diseases: 11 with ductal cell carcinoma, 10 with mucin-producing tumor, five with pseudo-cyst, four with islet cell tumor, four with chronic pancreatitis, and three with serous cystadenoma. After endoscopic ultrasonography, Albunex (0.22 ml/kg) was injected intravenously at a rate of 1 ml/s into the right median vein, and observation was continued for 10 min. The presence or absence of enhancement of the lesion was determined in each disease. Because all the patients with ductal cell carcinoma, islet cell tumor, chronic pancreatitis, and serous cystadenoma, as well as five with mucin-producing tumor and three with pseudo-cyst, underwent angiography, vascularity was compared between angiographic images and those of contrast-enhanced ultrasonography. RESULTS: Enhancement of the lesion was observed in all patients with islet cell tumor and serous cystadenoma, in eight with mucin-producing tumor, and in three with chronic pancreatitis. However, no enhancement effect was observed in the patients with ductal cell carcinoma and those with pseudo-cyst. Comparison between the images of contrast-enhanced endoscopic ultrasonography and angiographic images showed three patients in whom angiograms were hypovascular, but enhancement effect was observed on ultrasonographic images. CONCLUSION: The combined evaluation of plain and enhanced images of endoscopic ultrasonography may be useful for the diagnosis of pancreatic diseases.     

Increase in mucosal and connective tissue-type mast cells in the stomach with acetic acid-induced ulcer in rat

The fluorescent probe furaptra shows increases and decreases in the concentration of free magnesium ion, [Mg2+], in the mitochondrial matrix with changes in total Mg2+ and ligand availability. The factors involved in the calibration of these fluorescence changes in terms of absolute [Mg2+] have been investigated. The affinity of furaptra for Mg2+ is highly dependent on both temperature and ionic strength. The Kd for Mg-furaptra in solution in 100 mM KCl was found to be 2.1 +/- 0.1 mM at 25 degrees C. The use of this Kd to calculate matrix [Mg2+] is more reliable than in situ Kd measurements because ionophores, such as BrA23187 and ionomycin, do not equilibrate external Mg2+ with the matrix in an acceptable way. Furaptra is present at high concentrations (up to 500 microM) in the matrix when introduced by hydrolysis of the acetoxymethyl ester. However, absorbance spectra of aqueous solutions show no evidence of dimerization of the probe or other changes in properties at these concentrations. Fluorescence intensity at 340 nmex is strongly attenuated for matrix-sequestered furaptra, mag-fura-5, and mag-indo-1. This appears to result in part from preferential binding of the Mg-probe to mitochondrial proteins. The fluorescence of uncomplexed furaptra at 375-380 nmex seems unaffected by protein binding, however, and changes in intensity in this region of the spectrum can be used in conjunction with the Kd found in aqueous solution to estimate matrix [Mg2+]. The presence of secondary equilibria, such as protein binding, and possible changes in ionic strength may undermine exact quantitation by this method. However, values for matrix [Mg2+] obtained in this way (0.5 to 0.7 mM) correspond well to estimates by other available methods and each of these methods suffers from comparable uncertainties.     

Laparoscopic surgery of perforated duodenal and gastric ulcers

During the period of 13 months, the authors have operated on seven patients with perforated gastroduodenal ulcers. All surgeries were completely performed by the laparoscopic method. The laparoscopic suture of perforated ulcers was performed with lavage and only in one case it involved omentoplasty. The healing process was free of any complications in all patients. The advantage of laparoscopic operations of perforated ulcers resides in fast convalescence and in the fast restoration of working abilities. This method is appropriate in cases when the surgeon performing laparoscopic surgeries has sufficient experience in coincidence with the treatment of perforated ulcers.     

Is endoscopic injection hemostasis of bleeding gastrointestinal ulcers obsolete in 1995?

Bleeding non-neoplastic lesions of the upper gastrointestinal tract, not due to portal hypertension, are a frequent cause of emergency admission. In the present paper we report our retrospective experience in hemostatic injection treatment of these lesions. From May 1990 to May 1994, 164 patients were admitted to our institution for a bleeding gastrointestinal lesion. In 124 cases an ulcer classified according Forrest's criteria was detected. Four patients underwent immediate surgery. The second group of 86 patients (FIIa/FIIb/FIII) were treated conservatively. The third group of 34 patients (FIa/FIb/FIIa) underwent perilesional injection of adrenaline 1:10,000 and polidocanol 1% saline solution during endoscopic examination; 29% (25 pts) of the second group re-bled during the first 72 h vs 8.8% (3 pts) of the third group. The postoperative morbidity in the rebleeding patients was higher in the second group: 38.4% vs 0%. The importance of immediate, inexpensive, and simple hemostatic treatment extended to Forrest IIa lesions is emphasized.