Parosteal osteoma of the iliac bone

A 33-year-old patient with a 2-year history of intermittent pain in the right gluteal region and thigh presented with a large sclerotic lesion of the iliac bone. From the findings on radiography, scintigraphy, CT and MRI, a giant parosteal osteoma was suspected. The histological examination confirmed the diagnosis. Since the lesion was extensive it was observed with periodic follow-up examinations. At present, 5 years after the diagnosis, the patient is asymptomatic and imaging studies show that the lesion persists with reduction of sclerosis and size. The tumor was on the surface as well as intramedullary--only one other case with such a distribution is known to us--and it was also in the iliac bone.

Randomized clinical trial comparing two one-week triple-therapy regimens for the eradication of Helicobacter pylori infection and duodenal ulcer healing

OBJECTIVE

One-week triple therapy has been shown to be effective in Helicobacter pylori eradication and duodenal ulcer healing. However, the optimal therapeutic combination has not yet been identified. Bismuth-containing regimens have the advantage of requiring only one antibiotic. It has been suggested that high doses of omeprazole improve the bactericidal efficacy of antimicrobial regimens against H. pylori. We evaluated the efficacy of two 1-wk triple-therapy regimens for H. pylori eradication and duodenal ulcer healing.

METHODS

On an intention-to-treat basis, 182 patients with H. pylori-associated duodenal ulcer were randomized. Group OCB patients (n = 91) were given omeprazole 40 mg b.i.d., clarithromycin 500 mg b.i.d., and colloidal bismuth subcitrate 120 mg q.i.d. for 7 days. Group OCA patients (n = 91) were treated with omeprazole and clarithromycin at the same doses plus amoxicillin 1 g b.i.d., also for 7 days. Endoscopies were performed at entry and at 4 wk after the end of treatment. The presence of H. pylori was assessed by urease test, histology, Gram stain, and culture. No patient received follow-up treatment.

RESULTS

H. pylori eradication rates achieved in the OCB and OCA groups were similar whether by intention-to-treat (82.4% vs 88.9% ;p = 0.21) or per protocol analysis (83.3% vs 89.9%; p = 0.19). Duodenal ulcer healing rates also were the same for OCB and OCA in intention-to treat (91.2% vs 91.1%) and per protocol analysis (92.2% vs 92.1%), respectively (p = 0.98).

CONCLUSIONS

High rates of H. pylori eradication and duodenal ulcer healing were obtained with both short-treatment regimens, which were safe and well-tolerated. Colloidal bismuth subcitrate seems to be a good alternative to amoxicillin in the triple-therapy combination with omeprazole and clarithromycin. The omeprazole dose does not seem to play a major role in H. pylori eradication in these therapeutic combinations.

Immunofluorometric assay of pepsinogen C and preliminary clinical applications

We developed mouse monoclonal antibodies (Abs) against pepsinogen C with highly purified antigen isolated from gastric mucosa. The Abs were used to construct a two-site sandwich-type assay for pepsinogen C with time-resolved fluorometry as a detection technique. The assay has a detection limit of 0.1 microgram/L and is precise (within-run and day-to-day CVs < 11%). We used this assay to measure pepsinogen C in seminal plasma, breast cyst fluid, amniotic fluid, male and female serum, serum from patients with prostate cancer, urine, breast tumor cytosolic extracts, breast milk, and cerebrospinal fluid. Highest pepsinogen C concentrations were in seminal plasma, followed by breast cyst fluid and amniotic fluid. We found no correlation between prostate-specific antigen concentrations and concentrations of pepsinogen C in serum of prostate cancer patients, and concluded that this marker is not useful for either diagnosing or monitoring prostatic carcinoma. The availability of a highly sensitive, reliable, and convenient method for quantifying pepsinogen C will allow investigations into the possible diagnostic value of this analyte in various clinical conditions, including benign breast diseases, breast cancer, fertility, and pregnancy.

[Aneurysm of the antero-inferior pancreatoduodenal artery as a cause of massive digestive hemorrhage]

We report a case of anterior inferior pancreaticoduodenal artery aneurysm fissured to the duodenum, which obliged to an emergency operation. This is an infrequent cause of upper gastrointestinal bleeding. Diagnosis, therapeutic options and prognosis of this pathology are discussed.

Rapid and enhanced detection of mitochondrial DNA variation using single-strand conformation analysis of superposed restriction enzyme fragments from polymerase chain reaction-amplified products

A strategy is described for detecting mitochondrial (mt) DNA variation which permits rapid and straightforward screening for forensic purposes. The method is based on the selection of fragments with adequate length for performing single strand conformation polymorphism (SSCP) analysis selecting a set of restriction enzymes (RE) which yield fragments with prefixed lengths. After digestion of mtDNA by the appropriate enzyme or set of enzymes, SSCP analysis is performed in a semiautomatic electrophoretic system using a silver staining detection method. The conformational changes due to single mutations were therefore found not to change the electrophoretic protocol but to change the relative position of the mutations within the fragment. The discrimination power of this method is estimated to be 90% when two restriction enzymes (MspI and HinfI) are used, but it is considerably higher when other enzymes are added.

Incrimination of anaerobic bacteria in the induction of experimental colitis

Commensal bacteria may participate in the pathogenesis of bowel inflammation. We studied the role of bacteria from the rat colonic flora on transmural inflammation induced by 2,4,6-trinitrobenzenesulfonic acid (TNBS). First, bacterial translocation to the colonic wall after induction of colitis was assessed by microbiological and histological methods. Second, rats with a colonic segment excluded from fecal transit were prepared for recolonization with preselected bacteria and used to test the effects of different species on inflammation (eicosanoid release, tissue myeloperoxidase) and damage (histology). Six strains (three aerobes and three anaerobes) were identified in colonic tissue 24 h after induction of colitis. Acridine staining showed bacteria in necrotic areas of the mucosa and invading the submucosa. Rats with excluded colon and sterile culture of luminal washings showed mild inflammation and low mucosal damage in response to TNBS. Rats colonized with anaerobes showed significantly higher eicosanoid release than rats colonized with aerobes only. Moreover, submucosal-lesions were mostly observed in rats with anaerobes. Our findings suggest that colonic anaerobes play a key role in transmural inflammation.

Sequence variation of a hypervariable short tandem repeat at the D12S391 locus

A short tandem repeat (STR) in the D12S391 locus was sequenced in more than 40 individuals. Twenty different alleles were found and these could be grouped into 12 allelic classes in accordance with the total number of repeats. This is a compound STR consisting of blocks of (AGAT) and (AGAC) repeats with basic sequence structure (AGAT)8-17(AGAC)6-10(AGAT)0-1. Whereas smaller alleles (15-18) have variation limited to the (AGAT) unit, in larger alleles the complexity is greater with variation in the number of tandem arrays in the two motifs (AGAT) and (AGAC). Population data showed that this is a highly polymorphic STR with a heterozygosity of more than 0.9. This fact, together with its simple structure, makes this STR an interesting DNA polymorphism for forensic and genetic purposes.

[Fever of unknown origin in patients with HIV infection]

BACKGROUND

The aim of the study was to describe the etiology and clinical characteristics of fever of uncertain origin (FUO) among HIV-infected patients.

METHODS

Prospective analysis of 35 episodes of FUO in HIV-infected patients from Balearic Islands that were studied through established guidelines.

RESULTS

Most patients were at advanced stages of HIV-1 infection (mean CD4 cell count, 60/mm3). Mean duration of fever until diagnosis was 57 days. Average time of hospitalization until etiological diagnosis of FUO was 26 days (range: 8-127 days). The cause of FUO was identified in 33 cases (94%). Tuberculosis accounted for 18 cases (51%) and visceral leishmaniasis for 8 cases (23%). Other opportunistic infections were the cause of FUO in 8 cases (17%). In one patient, fever was due to Kaposi's sarcoma. Two patients died while febrile, without and identified etiology. Four patients had more than one cause that could contribute to FUO. Imaging techniques that yielded more diagnostic information were abdominal ultrasonography and serial chest X-ray. Leishmania serology and tuberculin skin test showed a high specificity but low sensitivities. Invasive procedures with a highest diagnostic field were fine needle aspirate of lymph nodes, and liver biopsy.

CONCLUSIONS

FUO is more frequent in advanced stages of HIV disease. In our area, FUO is caused primarily by endemic opportunistic infections specially TB and visceral leishmaniasis, and rarely can be attributable to HIV or neoplastic diseases.

Induction of chronic pancreatic disease by trinitrobenzene sulfonic acid infusion into rat pancreatic ducts

Despite being a common disease in humans, little is known about the etiopathogenesis of and effective therapeutic approaches to chronic pancreatitis, due mainly to the fact that few simple animal models suitable to study inflammatory and fibrogenetic processes have been described in the pancreas. Trinitrobenzene sulfonic acid (TNBS) induces chronic colitis and cholangitis in the rat. We hypothesized that TNBS instillation into the pancreatic ducts could also result in the development of a chronic pancreatic disease. The biliopancreatic duct of rats was cannulated and tied close to the liver. TNBS [0.4 ml of 2% TNBS in phosphate-buffered saline (PBS)-10% ethanol, pH 8] was infused into the pancreas under a continuous controlled-pressure system. Control rats underwent the same procedure using vehicle only. Pathology assessment of TNBS-treated rats examined at 48 h was consistent with severe acute necrotizing pancreatitis, having a morality rate of 31% and serum amylase activity of 37.4 +/- 8.8 U/ml at 24 h and 13.3 +/- 1.7 U/ml at 48 h (p < 0.01 for both time points compared to PBS/ethanol-treated rats). Groups of 10 rats each were killed at 3, 4, and 6 week after the surgical procedure. Morphological examination revealed changes mimicking features of chronic pancreatitis in humans in 80% (32 of 40) of TNBS-treated rats, consisting in various degrees of periductal and lobular fibrosis, duct stenosis, patchy acute and chronic inflammatory cell infiltrates, and signs of gland atrophy. Animals developing chronic disease had a weight gain rate significantly lower than that of control rats. Serum amylase, fasting glucose, and a glucose tolerance test were not different in diseased or control rats. In conclusion, we were able to induce chronic fibrogenetic inflammatory disease in the pancreas after a single pulse instillation of TNBS into the pancreatic ducts. This might be a useful animal model to study the pathophysiology of inflammatory, fibrogenetic, and reparative processes in pancreatic tissue.

[Pseudomonas spp. infections in patients with HIV infections]

BACKGROUND

The aim of this study was to describe the characteristics of the infections by Pseudomonas spp. observed in patients with HIV infection in Spain.

METHODS

A retrospective study was performed of the isolations of Pseudomonas spp. in microbiologic samples of patients with HIV infection in three hospitals from Mallorca, Spain, since 1986.

RESULTS

Twenty-nine patients with some positive culture for Pseudomonas were reviewed. In 20 cases the infection presented in advanced stages of the disease when the patient fulfilled AIDS criteria. The most frequent foci in both community acquired and nosocomial infection was respiratory (16 and 3 cases, respectively). Fifty percent of the cases presented bacteremia. The classically described predisposing factors for infection by this germ were presented in 19 patients. Pseudomonas aeruginosa was the most frequently isolated type (22 cases). Only 5 patients received the appropriate treatment on admission. Clinical cure was achieved in 23 patients, with recurrence being observed in 10. Five patients died in relation to the infection.

CONCLUSIONS

Infections by Pseudomonas spp. in Spain appear to have increased in frequency in patients with HIV infection in the last decade. These infections appear in advanced phases of the disease and mainly involve the lung, with high rates of bacteremia and a high number of recurrence. Empiric treatment of patients with advanced HIV infection with suspicion of bacterial infection should include antipseudomonic drugs.

Toxic dilatation of colon in a rat model of colitis is linked to an inducible form of nitric oxide synthase

The contribution of nitric oxide (NO) to the altered colonic contractility of acute colitis was investigated in the 2,4,6-trinitroben-zenesulfonic acid model. NO synthase was measured in colonic tissue; the effects of NO synthase inhibition on colonic contractility were studied in vitro and in vivo. Inducible NO synthase was not detected in normal colons, whereas inflamed colons showed high activity. Acute inflammation was associated with enlarged colonic perimeter. NO synthase inhibitors or selective inhibitors of the inducible enzyme prevented colonic dilatation. In vitro, contractile responses to KCl were lower in muscle from colitic than control rats. After NO synthase inhibition, however, no difference was observed between colitic and control muscle contractility. In vivo, intracolonic pressure was lower in colitic than in control rats. Selective inhibition of inducible NO synthase increased intracolonic pressure in colitic but not in control rats. In conclusion, NO generation by inducible enzymes impairs smooth muscle contractility in colitis and may be involved in the pathogenesis of toxic dilatation of the colon.

Diagnosis of ascending aortic dissection by transesophageal echocardiography: utility of M-mode in recognizing artifacts

OBJECTIVES

This study sought to assess the reliability of biplanar transesophageal echocardiography in the diagnosis of ascending aortic dissection and to test the utility of M-mode information in the differential diagnosis of ascending aortic ultrasound artifacts and intimal flap images.

BACKGROUND

Transesophageal echocardiography is a useful technique in the diagnosis of aortic dissection. However, ultrasound artifacts in the ascending aorta are an important limitation.

METHODS

Transesophageal echocardiography was performed in 132 consecutive patients with clinically suspected aortic dissection. Two-dimensional and M-mode echocardiography and color Doppler were used to diagnose intimal flap and artifact images. Diagnoses were validated either anatomically or with reference techniques.

RESULTS

The sensitivity and specificity of transesophageal echocardiography in the diagnosis of ascending aortic dissection were 96.8% and 100%, respectively. Ninety-three artifacts were observed in 56 (55%) of 101 patients without ascending aortic dissection. Two-dimensional echocardiography easily identified 74 artifacts (80%). Color Doppler showed no ascending flow abnormalities in 71% of artifact images. M-mode echocardiography showed three location and mobility artifact patterns related to the posterior wall of the aorta or the right pulmonary artery. In contrast, intimal flap movement showed no relation to the aortic wall movement in 25 cases (83%). Blind analysis of transesophageal echocardiographic study tapes underlined the utility of M-mode in the differential diagnosis. Ranges of sensitivity, specificity and positive predictive value (established by including doubtful results as either positive or negative) improved from 87.1-93.5% to 93.5-96.8%, from 85.1-94.1% to 99-100% and from 65.9-81.8% to 96.8-100%, respectively, with the inclusion of M-mode data.

CONCLUSIONS

Biplanar transesophageal echocardiography permits reliable diagnosis of ascending aortic dissection. Ultrasound artifacts are common, but assessment of the location and mobility of intraluminal images by M-mode echocardiography definitely improves diagnostic accuracy.

Induction of nitric oxide synthase in colonic smooth muscle from patients with toxic megacolon

BACKGROUND & AIMS

Colonic inflammation may lead to motility disturbances, including severe atony. Nitric oxide is released by inflamed tissue and induces smooth muscle relaxation. The aim of this study was to analyze NO generation pathways in colonic tissue from patients who had ulcerative colitis with or without toxic megacolon and in tumor-free samples from patients with colonic neoplasm.

METHODS

Enzymatic activity was determined by transformation of [14C]arginine to [14C]citrulline in mucosa and muscular layer samples. Immunostaining of tissue sections with antibody against inducible NO synthase was investigated. The effects of endotoxin on NO synthase activity was tested in muscle strips from human colon.

RESULTS

Ca(2+)-independent NO synthase was undetectable or very low in muscularis propria from tumor and colitis controls. In contrast, specimens from patients with toxic megacolon had high activity (P < 0.05). Positive immunostaining for inducible NO synthase was found in muscular layers from patients with megacolon but not in tumor and colitis controls. Finally, endotoxin induced Ca(2+)-independent NO synthase activity in colonic muscle.

CONCLUSIONS

Toxic megacolon is associated with the appearance of inducible NO synthase in the colonic muscularis propria. Local generation of excessive amounts of NO may be responsible for the colonic dilatation that is the hallmark of this syndrome.

Does Helicobacter pylori infection increase gastric sensitivity in functional dyspepsia?

The role of Helicobacter pylori infection in the pathogenesis of functional dyspepsia is debated. It is known that a substantial fraction of dyspeptic patients manifest a low discomfort threshold to gastric distension. This study investigated the symptomatic pattern in 27 H pylori positive and 23 H pylori negative patients with chronic functional dyspepsia, and potential relations between infection and gastric hyperalgesia. Specific symptoms (pain, nausea, vomiting, bloating/fullness, early satiety) were scored from 0 to 3 for severity and frequency (global symptom scores: 0-15). The mechanical and perceptive responses to gastric accommodation were evaluated with an electronic barostat that produced graded isobaric distensions from 0 to 20 mm Hg in 2 mm Hg steps up to 600 ml. Gastric compliance (volume/pressure relation) and perception (rating scale: 0-10) were quantified. Standard gastrointestinal manometry and recorded phasic pressure activity at eight separate sites during fasting and postprandially were also assessed. H pylori positive and H pylori negative patients manifested similar severity and frequency of specific symptoms and global symptom scores (mean (SEM)) (severity: 9.5 (2.0) v 9.0 (2.1); frequency: 10.8 (2.0) v 9.7 (2.2)). No differences were seen either in gastric compliance (53 (4) ml/mm Hg v 43 (3) ml/mm Hg) or in gastric perception of distension (slope: 0.50 (0.05) v 0.53 (0.06)). Postprandial antral motility was significantly decreased in H pylori positive patients (two hours motility index: 10.4 (0.6) v 12.6 (0.5); p < 0.05). It is concluded that H pylori infected patients with functional dyspepsia present no distinctive symptoms by comparison with H pylori negative counterparts and H pylori infection is associated with diminished postprandial antral motility but it does not increase perception of gastric distension.

Nitric oxide modulates pancreatic basal secretion and response to cerulein in the rat: effects in acute pancreatitis

BACKGROUND/AIMS

Nitric oxide synthase activity is detected in the pancreas, but the role of NO on pancreatic function has not been fully characterized. The aim of this study was to evaluate the role of NO in normal and diseased pancreatic function.

METHODS

Amylase and NO secretion were measured in vivo in rats and in vitro in dispersed acini, with and without NO synthesis blockade, by NG-nitro-L-arginine methyl ester (L-NAME). Rats were subjected to cerulein-induced pancreatitis, and the effects of L-NAME or NO donors were assessed.

RESULTS

L-NAME reduced amylase output to 60% of basal. This effect was reversed by L-arginine. The secretory response to optimal doses of cerulein induced a poor amylase secretion and a marked release of NO. High doses of cerulein in combination with L-NAME inhibited NO formation and amylase secretion. In dispersed acini, supramaximal cerulein concentrations induced NO release, but the amylase dose-response curve was not modified by NO inhibition. In acute pancreatitis, L-NAME increased amylasemia and tissue myeloperoxidase activities, whereas NO donors reduced amylasemia, lipasemia, and the histological damage score.

CONCLUSIONS

The L-arginine/NO pathway facilitates basal and stimulated pancreatic secretion in vivo. NO donor drugs may improve the course of acute pancreatitis.

[Changes in the natural history of AIDS in patients from Mallorca and Ibiza: 1986-1992]

BACKGROUND

Longitudinal follow-up studies in patients with human immunodeficiency virus (HIV) infection and AIDS, which are fundamental for the knowledge of variations the natural history of this disease, have generally been carried out by Public Health Departments and in populations in which homosexual males predominate. The aim of the present study was to analyze the changes in the natural history of the patients diagnosed with AIDS in the islands of Mallorca and Ibiza.

METHODS

A prospective study of the adult patients diagnosed with AIDS in Mallorca and Ibiza, from 1986 to 1992 was performed.

RESULTS

The annual incidence of the cases of AIDS increased throughout the study. The mean age of the patients did not vary, and neither did that in relation to sexes. A progressive decrease was observed in CD4 lymphocytes at the time of diagnosis (from 0.168 x 10(9)/l in 1986 to 0.079 x 10(9)/l in 1992). There was an increase in heterosexual transmission patients with no known risk factors also increased over the period studied. The incidence of extrapulmonary tuberculosis decreased both as the form of presentation and in its global frequency. Pneumonia by Pneumocystis carinii increased mainly as a initial feature. The median survival was 547 days and did not vary significantly throughout the study.

CONCLUSIONS

The epidemiologic and clinical study of AIDS in Mallorca and Ibiza, Spain is similar to that observed in other Mediterranean regions. The incidence of extrapulmonary tuberculosis has decreased.

Induction of chronic cholangitis in the rat by trinitrobenzenesulfonic acid

We investigated the effects of the hapten trinitrobenzenesulfonic acid instilled into the rat biliary tree. The study included three groups of animals that received a single intracholedochal injection of either saline, 10% ethanol or 10 mg trinitrobenzenesulfonic acid dissolved in 10% ethanol. A fourth group of rats was subjected to common bile duct ligation and was used as control for biliary obstruction. Liver and biliary tract dysfunction was assessed 1, 10, 20 and 30 days after treatment by serum aspartate aminotransferase, alkaline phosphatase and bilirubin, and by histopathological examination of liver slices. By day 10, saline- or ethanol-treated rats did not show changes in the biochemical parameters, and light microscopy revealed no alterations. In contrast, rats treated with trinitrobenzenesulfonic acid showed significant increases in all serum markers throughout the study period. Inflammatory cell infiltrates were seen in portal areas and around bile ducts, indicating pericholangitis. Some rats presented with dilatation of extrahepatic biliary ducts; ductal proliferation and thin porto-portal fibrotic septa were observed in these cases. Bile duct ligation also induced ductal proliferation and fibrosis in all cases, but pericholangitis was not prominent. Retrograde cholangiograms in trinitrobenzenesulfonic acid rats showed distortion of the intra- and extrahepatic biliary tree. In conclusion, chronic cholangitis may be consistently induced in rats by a single intracholedochal administration of trinitrobenzenesulfonic acid.

Phosphatidylcholines as mediators of adaptive cytoprotection of the rat duodenum

BACKGROUND/AIMS

Surfactant phospholipids impede diffusion of acid through the gastric mucus, but their relevance in the defense of the duodenum against luminal acid is not known.

METHODS

Duodenal resistance to acid was tested in anesthetized rats by instillation of HCl using a tube implanted in the proximal duodenum. The effects of a detergent (Brij 35; Sigma, St. Louis, MO) and a lipid mixture flushed through the luminal surface on duodenal resistance to acid were studied. The lipid content in the mucus and the effects of acid, prostaglandins, and indomethacin on the lipid layer were also analyzed.

RESULTS

Instillation of 100 mumol HCl or 5 micrograms/kg 16,16-dimethyl prostaglandin E2 increased resistance to acid, preventing duodenal lesions induced by 500 mumol HCl. However, 100 mumol HCl or 16,16-dimethyl prostaglandin E2 did not prevent lesions induced by 500 mumol HCl in rats undergoing perfusions with 5% Brij 35. Indomethacin suppressed acid-induced protection. A mixture of tripalmitin and dipalmitoyl-phosphatidylcholine protected against 500 mumol HCl, and the effect was also observed in rats receiving indomethacin. Finally, 100 mumol HCl increased the phosphatidylcholine content in the duodenal mucus but not in rats receiving 5% Brij 35 or indomethacin.

CONCLUSIONS

Surface-active phospholipids are critical for adaptive cytoprotection to acid in the rat duodenum.

Role of intestinal microflora in chronic inflammation and ulceration of the rat colon

Bacteria and their products stimulate inflammatory responses. The effects of different antimicrobial regimens (amoxicillin/clavulanic acid, tobramycin, imipenem, vancomycin, metronidazole) were investigated on the course of experimental colitis induced by trinitrobenzenesulphonic acid (TNB) in the rat. On day 7 and 21 after the induction of colitis, matched groups of control and antibiotic treated rats were subjected to colonic dialysis to measure eicosanoid release, and killed for morphological assessment of the colonic lesions (macro and microscopic scores). Stool samples were cultured. Selective antibiotic treatment against Gram positive, Gram negative or anaerobic bacteria had no effect on colonic lesion scores. By contrast, certain broad spectrum antibiotics (amoxicillin/clavulanic acid or the association of imipenem plus vancomycin) significantly reduced macro and microscopic scores. Rats receiving these antibiotics did not develop chronic colitis as shown by the virtual absence of colonic strictures, adhesions, fibrosis, and granulomas. On day 21 after TNB, the intracolonic release of prostaglandin E2, thromboxane B2, and leukotriene B4 was significantly higher in control than in antibiotic treated rats. Control stool cultures showed abundant colony forming units of both aerobic and anaerobic bacteria. Amoxicillin/clavulanic acid and imipenem plus vancomycin induced appreciable reductions in luminal bacteria. In conclusion, certain broad spectrum antibiotics prevent chronic colitis. The normal colonic flora seems to play an important pathogenetic part in the progression of inflammatory colonic lesions to chronicity.

[Intraluminal crystalloids in prostatic carcinoma: morphologic and histochemical study]

The histological sections of 302 diagnosed cases of prostate carcinoma were analyzed for intraluminal crystalloids, correlating their presence, number and characteristics with other morphological parameters used for the diagnosis of prostate carcinoma. Evidence of these structures was found in 65 cases (21.5%). The majority developed in malignant glands though they were also found in benign glands adjacent to cancerous foci. Their presence indicates good tumoral differentiation and both their number and shape are dependent on the tumour's histological grade.

[Nitric oxide and Hirschsprung's disease: a causal relation biochemically, immunohistochemically and functionally demonstrated]

Hirschsprung's disease may be due to impaired nonadrenergic-noncholinergic inhibitory input in the aganglionic segment of the colon. It has been suggested that nitric oxide (NO) might be the lacking neurotransmitter. Thus, our specific aims were to determine in ganglionic and aganglionic segments: 1. The activity of the NO synthetase (NO-S); 2. The location of this enzyme; and 3. The "in vitro" basal motor activity of the muscle strips and their responses to an NO donor and to an NO antagonist.

METHODS

NO synthetase activity was quantified in samples of tissue from both aganglionic and ganglionic segments obtained during surgery in 6 patients with Hirschsprung's disease by the transformation of 14C-L-arginine into 14C-L-citrulline in tissue homogenates. Immunohistochemical staining of the tissues was performed using a polyclonal antibody raised against a peptide sequence of rat brain NO synthetase. Furthermore, in 2 patients we measured "in vitro" the tonic response of muscle strips to an exogenous NO donor (sodium nitroprusside) and to an NO antagonist (L-NAME).

RESULTS

NOS activity was undetectable in every aganglionic segment whereas it was present in all ganglionic segments (0.49 +/- 0.09 pmol citrulina/mg.min; mean +/- SE). Immunohistochemically, NO-S was absent in the myenteric plexus of aganglionic segments and it was present in ganglionic segments. "In vitro" basal motor activity of ganglionic segments was normal, with presence of low-frequency contractions (LFC) and summation contraction (SC); in aganglionic segments SC were absent. Sodium nitroprusside induced a marked relaxation (90% from basal) in muscle strips, both aganglionic and ganglionic, precontracted with bethanocol.(ABSTRACT TRUNCATED AT 250 WORDS)

Abnormal leukotriene C4 released by unaffected jejunal mucosa in patients with inactive Crohn's disease

The mucosal release of inflammatory mediators is enhanced in active inflammatory bowel disease. This study examines whether leukotriene C4 production occurs in apparently unaffected segments of the gut. The intraluminal release of leukotriene C4 was determined by jejunal perfusion in seven healthy controls, in nine patients with chronic ulcerative colitis, and in 13 patients with Crohn's disease (six with ileal disease, and seven with only colonic). All patients were in clinical remission and none of them had evidence of jejunal involvement. Mild intraluminal irritation with a 2.5 mmol/l deoxycholic acid solution was induced to stimulate local inflammatory mechanisms. The release of DNA (a marker of mucosal desquamation) and prostaglandin E2 (PGE2) was simultaneously measured. Jejunal release of DNA was higher in Crohn's disease patients than in ulcerative colitis or healthy controls. Basal release of PGE2 was similar in the three groups of patients. Basal release of leukotriene C4 was considerably enhanced, however, in Crohn's disease patients compared with healthy controls. In ulcerative colitis patients, basal leukotriene C4 release was non-significantly different from controls. Bile acid perfusion stimulated PGE2, leukotriene C4, and DNA release in all groups studied, but leukotriene C4 release was significantly higher in Crohn's disease patients. It is concluded that in inactive Crohn's disease there is an enhanced intraluminal release of leukotriene C4 in apparently unaffected segments of proximal small bowel, which may reflect fundamental changes in the function of the gut mucosal barrier.

[The control of arterial hypertension in primary care: the evaluation of a program of self-care]

OBJECTIVE

To evaluate the efficacy of a self-care hypertension programme within primary care.

DESIGN

Two models of intervention by means of self-care were compared, both using individual education and family support, with one of them using group education.

SETTING AND PATIENTS

All those attending 10 health centres in Andalucía and who had a recent diagnosis of light or moderate Hypertension or with their hypertension not monitored over the preceding 6 months, were included.

MEASUREMENTS AND MAIN RESULTS

These 160 people were assigned at random to the intervention group (group education) or the control group (individual education). Data analysis provided the results for the 95 people who completed the study. Both systolic and diastolic arterial pressure (SAP and DAP) diminished significantly during the study period, both in the sample as a whole and in the intervention group. However, the lessening of systolic pressure only reached statistically significant differences in the control group. Over the study period, the lessening of SAP was 6.2 in the intervention group and 8.0 in the control group; whereas the lessening of DAP was 7.0 in the intervention group and 2.3 in the control group.

CONCLUSIONS

Arterial hypertension can be controlled in primary care by health education for self-care. On the basis of this study's findings, it is not valid to conclude that group is more efficacious than individual education.

Localized fibrous tumor of the pleura: immunohistochemical and flow-cytometric DNA study

This report describes three cases of localized fibrous tumor of the pleura (LFTP) with clinical and pathological differences. Case 1 presented with symptoms; the tumor size was 6.5 cm and it was attached to the lung and chest wall; histologically it was composed of spindle cells with pleomorphism, mitoses, hemorrhage and necrosis. Cases 2 and 3 were casual findings and consisted of well-circumscribed tumors of 3 and 8.5 cm, respectively; histologically both showed hypocellularity. All cases exhibited positive stains for vimentin and negative for keratin. These results, added to histological features, suggested a mesenchymal origin. Flow cytometry quantitation of DNA disclosed a diploid pattern in all three cases with a small "near diploid" cell population additionally in Case 1; the S-phase fraction was low in all cases. These findings, that could be considered favourable prognostic signs, and the complete tumoral resection performed in the three tumors, could explain the absence of recurrences after 32, 27 and 19 months, respectively.

[Considerations regarding the treatment of non-aganglionic congenital intestinal neuropathies]

Hyperganglionosis or neuronal intestinal dysplasias (NID) and hypoganglionosis (HO) are intestinal diseases of difficult diagnosis and treatment and diverse evolution, despite identical histologic findings. The aim of this study was to discuss the therapeutic problems derived from the patients differing clinical course. Retrospective review of 14 patients with regard to diagnosis, manometry and histology (hematoxylin-eosin, acetylcholinesterase activity, immunohistochemistry and Smith's silver stain) was done. Six patients presented intestinal occlusion or sub-occlusion from the first months of life with impeded oral feeding. Ileostomy was performed in 5 and total colectomy with anastomosis in 1. All patients required parenteral nutrition; cisapride was added in 2. Three died from sepsis (3 NID). Of the 3 survivors, 2 have ileostomies (2 NID) and the other ileo-rectal anastomosis (NID). Of the remaining patients, two presented aganglionism and the finding of proximal hyperganglionism occurred post-surgery. Surgery was repeated in one patient. The remaining 6 (1 HO, 5 NID) were diagnosed between 3 and 10 years of age because of constipation. Four are under treatment with cisapride and 2 required partial colic resection. No relationship can be established between histologic findings and clinical manifestations. In chronic clinical courses, treatment with cisapride and cleaning enemas should be tried first. Acute clinical pictures (occlusion-sub occlusion) should be treated by decompressive ileostomy. Partial colic resection may lead to new intestinal failure.

[Transesophageal echocardiography in the diagnosis of aortic dissection]

INTRODUCTION AND OBJECTIVE

Eighty-two patients with suspected aortic dissection were studied to assess the usefulness of transesophageal echocardiography in the diagnosis of this entity.

METHODS

All patients underwent transesophageal echocardiogram. The diagnosis of aortic dissection was established in 46 patients by other diagnostic procedures including angiography and computed tomography, surgery and necropsy.

RESULTS

The sensitivity and specificity of transesophageal echocardiography were 98% and 97%, respectively. By computed tomography, sensitivity was 92% and specificity 88%. By angiography, sensitivity and specificity were 97% and 93%, respectively. In the diagnosis of the dissection type, transesophageal echocardiography classified correctly in 98%, computed tomography in 89% and angiography 97% of cases. Transesophageal echocardiography visualized the tear in 82% of cases, and angiography in 53%.

CONCLUSIONS

Transesophageal echocardiography provides rapid, accurate diagnosis of aortic dissection and permits the initiation of appropriate treatment. Angiography is indicated in non-conclusive cases or those which supra-aortic involvement clinically suspected.

Patients with achalasia lack nitric oxide synthase in the gastro-oesophageal junction

The abnormal function of the lower oesophageal sphincter in achalasia is likely to be due to impaired nonadrenergic, noncholinergic (NANC) inhibitory input. Since recent studies in animals suggest that nitric oxide (NO) is implicated physiologically in the inhibitory responses of the lower oesophageal sphincter, we have investigated whether the synthesis of NO is altered in the gastro-oesophageal junction of patients with achalasia. NO synthase activity was investigated in samples of tissue from the gastro-oesophageal junction obtained during surgery in eight patients with typical achalasia and six non-achalasic controls who underwent oesophagectomy for reasons other than sphincter dysfunction. The NO synthase activity was determined by the transformation of 14C-L-arginine into 14C-L-citrulline in tissue homogenates. In addition, immunohistochemical staining of the tissues was performed using a polyclonal antibody raised against a peptide sequence of rat brain NO synthase. Furthermore, the relaxant response to an exogenous NO donor (sodium nitroprusside, SNP) was measured in vitro in muscle strips obtained from two patients with achalasia and in two non-achalasic controls. NO synthase activity was detected in each of the samples obtained from six control patients (0.59 +/- 0.21 pmol mg-1 min-1; mean +/- SE). By contrast, none of the samples obtained from the eight patients with achalasia had any detectable NO synthase activity. Immunohistochemical studies confirmed the presence of NO synthase in the myenteric plexus of the gastro-oesophageal junction of control patients and its absence in achalasia. SNP relaxed muscle strips precontracted with bethanechol in both control samples and those from patients with achalasia.(ABSTRACT TRUNCATED AT 250 WORDS)

Influence of dietary fat on duodenal resistance to acid

Three experimental diets were prepared from a standard formula plus pure oleic, linoleic, or eicosapentaenoic acid (2% by weight). Mucosal resistance to acid was tested in anaesthetised rats fed the experimental diets for at least four weeks (60 rats per diet) by duodenal infusion of HCl (200 to 700 mumol) 30 minutes after pretreatment with either saline or 100 mumol HCl (used as a mild irritant). Rats were killed one hour after the test and the duodenal damage was assessed 'blindly' using a combined macroscopic and histological score. Differences were tested by analysis of covariance of the dose-response curves. Mucosal resistance was similar in the three groups when the acid challenge was given after saline pretreatment. Resistance to acid in all three groups was significantly increased by previous exposure to 100 mumol HCl (p < 0.01). Interestingly, rats fed a linoleic or eicosapentaenoic supplemented diet after pretreatment with HCl developed significantly higher resistance to acid than those fed the diet with oleic acid (p < 0.05). Pretreatment with indomethacin suppressed the difference between diets. In conclusion, dietary polyunsaturated fatty acids enhance duodenal resistance to acid by potentiation of adaptive cytoprotection.

Polyostotic coexisting fibrous dysplasia and aneurysmal bone cyst of the chest wall

A case of a 39-year-old woman with a palpable mass in the right hemithorax is presented. The mass had been growing during the last 16 years. Radiographs and computed tomography showed two lesions in the right thoracic wall: the greater was in the anterior and lateral portion of the 7th rib, the minor lesion in the 6th rib costovertebral joint. Both lesions were surgically removed. Histological examination demonstrated the association of fibrous dysplasia and aneurysmal bone cyst in the two lesions. The coexistence of these two lesions supports the theory that aneurysmal bone cyst may represent a secondary change due to haemodynamic alterations of the vascular bed caused by fibrous dysplasia.

Adaptive cytoprotection of the rat duodenum is not dependent on nitric oxide-induced changes in blood flow

Mild irritation of the rat duodenum enhances mucosal resistance to acid via a prostaglandin-mediated mechanism. Prostaglandins increase mucosal blood flow, but it is not known whether such changes in blood flow significantly contribute to adaptive cytoprotection. We induced blood flow changes by manipulating the arginine-nitric oxide pathway, which is independent from prostaglandin synthesis, and determined the resulting effects on the cytoprotective response. In anesthetized rats, we tested the effects of intraduodenal infusion of mild acid on duodenal blood flow and on the prevention of mucosal damage by subsequent strong acid in control, indomethacin-pretreated, and NG-nitro-L-arginine-pretreated rats (NG-nitro-L-arginine inhibits the nitric oxide synthase). Additional experiments tested the effects of the prostaglandin analogue 16,16-dimethyl-prostaglandin (PG) E2 or sodium nitroprusside (nitric oxide donor) on duodenal blood flow and on mucosal protection against acid. Exposure of the duodenal mucosa to mild acid increased duodenal blood flow and mucosal resistance to acid. Instillation of 16,16-dimethyl-PGE2 also increased blood flow and mucosal resistance to acid. However, sodium nitroprusside increased blood flow without increasing mucosal resistance to acid, and NG-nitro-L-arginine inhibited the change in blood flow induced by acid while preserving the adaptive cytoprotection phenomenon intact. In conclusion, adaptive cytoprotection of the duodenal mucosa appears to be independent of changes in blood flow.

[Extrabronchial small-cell carcinoma: apropos 6 cases]

Extrabronchial small cell carcinoma (ESCC) is an infrequent tumor with controversial histogenesis, clinical evolution and therapeutic strategy. The aim of this study was to know the immunohistochemical features and the clinical evolution of patients diagnosed of ESCC during a 10 year period. All the diagnoses of small cell carcinoma (bronchial and extrabronchial) carried out by the Unit of Pathology between 1980-1989 were reviewed. In all the ESCC an immunohistochemical study was performed with three neuroendocrine markers, chromogranin, neurospecific enolase and synaptophysin. The clinical evolution of the patients is described. The 6 patients with ESCC represented 4.7% of all the small cell carcinomas. The primary localization was: parotid, urinary bladder, the skin, maxillary sinus and esophagus (2 patients). In five cases positivity was observed for one or more of the neuroendocrine markers. In two cases the ESCC was associated with differentiated cell populations (squamous carcinoma). The diagnosis of ESCC logically obliges the bronchial origin and the presence of ectopic hormonal secretion syndromes to be discarded. The administration of chemotherapy regimes used in small cell lung carcinoma is advised.

Duodenal mucosal resistance to intraluminal acid in the rat: role of adaptive cytoprotection

The duodenal mucosa is normally challenged by intermittent exposure to acid because of periodic gastric emptying. We studied the mechanisms of duodenal adaptation to acid in anesthetized rats. A polyvinyl chloride tube passing through a ligated pylorus was used for duodenal pulse instillations of 1 mL of saline or acid (100 or 400 mumols HCl) at 30-minute intervals. Duodenal lesions were blindly assessed using a combined macroscopic and histological score. Mucosal damage after exposure to saline or 100 mumols HCl was negligible in intact, vagotomized, and indomethacin-pretreated rats, whereas 400 mumols induced noticeable macroscopic and microscopic lesions. Interestingly, in intact and vagotomized rats, previous exposure to a 100-mumols HCl bolus significantly prevented mucosal damage by a subsequent 400-mumols bolus. This effect was not observed in indomethacin-pretreated rats. In these rats, however, intraduodenal instillation of exogenous 16,16-dimethyl prostaglandin E2 (16,16-dm-PGE2) prevented the damage induced by 400 mumols of HCl. A second protocol investigated the luminal release of bicarbonate and PGE2 in response to intraduodenal perfusion with 100 mumols of HCl. Duodenal bicarbonate release was stimulated by acid in all groups, whereas the release of PGE2 increased in intact and vagotomized rats but not in the indomethacin-pretreated group. In summary, these data suggest that adaptive cytoprotection plays a significant role in protecting the duodenal mucosa from acid. Vagal innervation and bicarbonate release do not appear to be as critical as cyclo-oxygenase activity for this mechanism.

[Intestinal dysmotility-pseudo-obstruction]

Chronic intestinal pseudo-obstruction is defined as a syndrome related to any process which affects intestinal regulation and propulsion. Its origin may be muscular, neurogenic or hormonal, excluding Hirschsprung's disease or any known mechanical obstruction. Between 1989 and 1991, 11 patients with intestinal pseudo-obstruction were studied at our centre, and included nine hyperganglionisms B, and two hypoganglionisms) and two visceral myopathies (Berdon's syndrome). Diagnosis was established in all cases by histologic study. The techniques of haematoxylin-eosin, acetylcholinesterase, enolase, protein S-100 and Smith were used in neuropathies and haematoxylin-eosin and Masson's trichromic in myopathies. Intestinal motility was studied by ano-rectal and gastrointestinal manometry in seven and three cases respectively. Gastrointestinal manometry and radiology permitted differentiation of localized and diffuse forms of involvement. Medical treatment consisted of total parenteral nutrition when oral feeding was impossible, and in five cases, cisapride was given, with good results in four. Derivative surgery was performed in cases of diffuse involvement, and resection with anastomosis in those of localized forms. We conclude that: 1. Diagnosis is established according to histologic criteria. 2. Complementary examinations should be directed towards distinguishing localized from diffuse involvement. 3. Cisapride was effective in the treatment of neuropathies in the majority of cases.

Visceral leishmaniasis: another HIV-associated opportunistic infection? Report of eight cases and review of the literature

Visceral leishmaniasis (VL) is considered an opportunistic infection in immunocompromised patients. We review the clinical, laboratory, and therapeutic data in 63 patients (eight new cases and 55 cases reported in the literature) with Mediterranean VL (kala azar) and HIV-1 infection to determine whether VL should be considered an opportunistic infection in HIV-infected adults. We conclude that: (1) in areas where both leishmaniasis and HIV-1 infection are endemic, VL may be more frequent among HIV-infected adults; (2) in HIV-infected patients, the clinical picture did not differ significantly from classical kala azar, although it often ran a recurrent course, with resistance to antimonial therapy. We propose the inclusion of VL in the IVC-2 subgroup of the Centers for Disease Control (CDC) clinical classification of HIV-1 infection while prospective and larger studies further define whether there are clinical presentations that could justify adding VL to the list of opportunistic infections indicative of AIDS.

Neuromesenchymal hamartoma of the small bowel

We present the case of a long small bowel stricture with pathological features similar to those described as "neuromuscular and vascular hamartoma," showing in addition extensive fatty submucosal infiltration and fibrous intramural nodules. In the controversy about the nature of this disorder, we consider it a separate entity. Taking into account that other mesenchymal tissues than the originally described can participate, we propose the alternative term of "neuromesenchymal hamartoma" of the small bowel.

Dietary fish oil reduces progression of chronic inflammatory lesions in a rat model of granulomatous colitis

Eicosanoids are modulators of defensive and inflammatory processes in the gut mucosa, and may be involved in the pathogenesis of chronic inflammatory lesions of the bowel. As omega-3 fatty acids compete with the omega-6 as precursors of eicosanoid synthesis, we compared the effects of dietary supplementation with either sunflower (source of omega-6) or cod liver (source of omega-3) oil on the development of chronic granulomatous lesions in the rat colon. After four weeks on the supplemented diets, plasma omega-6 fatty acid content was significantly higher in the sunflower group, while omega-3 fatty acids predominated in the cod liver group. Inflammatory colitis was then induced by intracolonic administration of trinitrobenzene sulphonic acid. Luminal eicosanoid release, as measured by radioimmunoassay of intracolonic dialysis fluid, increased significantly after the challenge in both groups. Generation of prostaglandin E2 (PGE2) and leucotriene B4 (LTB4) peaked by day 3 and thereafter declined; thromboxane B2 (TXB2), instead, continued to increase from day 3 to 20 in sunflower fed rats, whereas this change was blunted in cod liver animals. The rats were killed 20, 30, or 50 days after the induction of colitis, and the colonic lesions were scored macroscopically (adhesions to surrounding tissues, strictures, ulcerations, and wall thickness) and histologically (ulceration, inflammation, depth of the lesions, and fibrosis). In cod liver animals, the damage score was markedly reduced by day 30, and inflammation and ulceration were almost absent by day 50. In conclusion, a fish oil diet prevents the increase in thromboxane in the chronic state of inflammation and shortens the course of the colonic disease by diminishing both the severity of the lesions and their progression to chronicity.

Participation of thromboxane and other eicosanoid synthesis in the course of experimental inflammatory colitis

Eicosanoids, as modulators of inflammation, may be involved in the pathogenesis of inflammatory bowel disease. We investigated their potential role in a rat model of chronic granulomatous colonic inflammation induced by trinitrobenzene sulphonic acid. Luminal eicosanoid release was quantified in vivo using a dialysis bag placed into the distal colon. We tested the effect of drugs known to modify inflammatory activity or arachidonic acid metabolism. Three days after intracolonic injection of trinitrobenzene sulphonic acid at different dose levels, the dialysates showed a highly significant increase of prostaglandin E2, 6-keto-prostaglandin F1 alpha, thromboxane B2 (TXB2), and leukotriene B4, compared with levels in controls not subjected to the toxic agent. Remarkably, the release of TXB2 continued to increase during the stage of chronic inflammation (up to day 21), whereas the levels of the remainder eicosanoids declined. Treatment with prednisone or 5-aminosalicylic acid reduced TXB2 levels in the chronic stage of the inflammatory disease and improved the morphological damage as assessed macroscopically and histologically. Moreover, two selective thromboxane synthetase inhibitors, OKY 1581 and R70416, significantly reduced the development of chronic inflammatory lesions in the colon while inhibiting the release of TXB2. Our results indicate that (1) luminal release of thromboxane increases in the chronic stage of colonic inflammation, (2) anti-inflammatory treatment reduces tissue damage and thromboxane release, and (3) selective thromboxane synthetase inhibition improves the course of the disease in our experimental model.

[Infection caused by the human immunodeficiency virus, hepatitis B virus and delta virus in homosexual males]

Serological markers of hepatitis B (HBV) and human immunodeficiency (HVI) viruses were investigated in the sera of 90 homosexual males. In addition, in HBsAg positive individuals antibodies against delta virus (DV) were also investigated. Forty sera (44.4%) were positive for HBV and HIV, 61 (67.7%) for HBV and 52 (57.7%) for HIV. HBsAg was detected in 8 cases (8.8%), 7 of which had positive anti-HIV sera. In no case infection by DV was detected. These data show the high prevalence of HBV and HIV infection in the study population. They also suggest that the HBsAg carrier status is more common among HIV positive homosexual males and that the investigated homosexual population has not yet been infected by DV.

[Intravenous streptokinase in acute myocardial infarction. Reduction of early in-hospital mortality]

A randomized study of the effects of intravenous streptokinase was performed in 214 patients with an acute myocardial infarction of less than 4 hours of whom 110 were included in the therapeutic group (SK) and 104 in the control group (C). Incidence of angiographic recanalization was higher in SK group (71 vs 28%, p less than 0.001) as that of non-significant residual coronary artery stenosis (less than 70%, 16% vs 3%, p less than 0.005), particularly in young patients (less than 45 years; 42% vs 8%, p less than 0.05). However, SK group presented a higher incidence of severe residual stenosis (90-99%) (SK, 42% vs C, 22%, p less than 0.01). Ejection fraction was higher among recanalized patients in both groups. Peak CPK-MB occurred earlier in SK group (13 vs 19 hours, p less than 0.001) and also among the recanalized patients of each group (SK, 12 vs 16 hours, p less than 0.001; C, 15 vs 21 hours, 0.002). The course of ST segment was similar in the 2 groups. The occurrence of ventricular arrhythmias within the first hour was greater in SK group (40% vs 20%, p less than 0.002), whereas the incidence of pericarditis (14% vs 35%, p less than 0.001) and of early mortality (less than 5 days, 2% vs 10%, p less than 0.02) was lower in SK group. The incidence of cardiac rupture, confirmed at necropsy in each of the 5 cases studied, was also lower in SK group (1 vs 8).(ABSTRACT TRUNCATED AT 250 WORDS)

Central regulation of gastric acid secretion by platelet-activating factor in anesthesized rats

PAF has been implicated in the pathogenesis of acute gastric injury. When given peripherally, PAF induces severe gastric mucosal damage. PAF metabolizing enzymes are present in the brain but the central effects of PAF on the stomach are unknown. We have investigated in the rat the gastric secretion and gross mucosal integrity in response to intracerebroventricular (icv) PAF and compared it with that to icv TRH, a known central gastric secretagogue. Gastric acid output was markedly increased by TRH (171.6 +/- 26.3 mumol/h mean +/- SE) and by 20 micrograms/kg/h iv pentagastrin (107.6 +/- 23.6) when compared to controls receiving icv vehicle (20.2 +/- 7.5; p less than 0.01 for both). In contrast, acid output decreased after icv PAF (13.5 +/- 7.5). Furthermore, icv PAF markedly inhibited acid output stimulated by iv pentagastrin (45.1 +/- 7.03; p less than 0.05). Morphological studies showed acute gastric mucosal erosions after icv TRH and no damage was observed after icv PAF or vehicle. Thus, icv PAF reduces pentagastrin stimulated acid output and does not alter gastric mucosal integrity, whereas icv TRH stimulates acid secretion and induces gastric injury. The opposite effects of PAF and TRH suggests the existence of a gastric modulatory system at the central level.