Toxicology of protein allergenicity: prediction and characterization. (17/2511)

The ability of exogenous proteins to cause respiratory and gastrointestinal allergy, and sometimes systemic anaphylactic reactions, is well known. What is not clear however, are the properties that confer on proteins the ability to induce allergic sensitization. With an expansion in the use of enzymes for industrial applications and consumer products, and a substantial and growing investment in the development of transgenic crop plants that express novel proteins introduced from other sources, the issue of protein allergenicity has assumed considerable toxicological significance. There is a need now for methods that will allow the accurate identification and characterization of potential protein allergens and for estimation of relative potency as a first step towards risk assessment. To address some of these issues, and to review progress that has been made in the toxicological investigation of respiratory and gastrointestinal allergy induced by proteins, a workshop, entitled the Toxicology of Protein Allergenicity: Prediction and Characterization, was convened at the 37th Annual Conference of the Society of Toxicology in Seattle, Washington (1998). The subject of protein allergenicity is considered here in the context of presentations made at that workshop.  (+info)

Nitric Oxide. V. therapeutic potential of nitric oxide donors and inhibitors. (18/2511)

Nitric oxide is a crucial mediator of gastrointestinal mucosal defense, but, paradoxically, it also contributes to mucosal injury in several situations. Inhibitors of nitric oxide synthesis and compounds that release nitric oxide have been useful pharmacological tools for evaluating the role of nitric oxide in gastrointestinal physiology and pathophysiology. Newer inhibitors with selectivity for one of the isoforms of nitric oxide synthase are even more powerful tools and may have utility as therapeutic agents. Also, agents that can scavenge nitric oxide or peroxynitrite are promising as drugs to prevent nitric oxide-associated tissue injury. Compounds that release nitric oxide in small amounts over a prolonged period of time may also be very useful for prevention of gastrointestinal injury associated with shock and with the use of drugs that have ulcerogenic effects. Indeed, the coupling of a nitric oxide-releasing moiety to nonsteroidal anti-inflammatory drugs has proven to be a valid means of substantially reducing the gastrointestinal toxicity of these drugs without decreasing their efficacy.  (+info)

Urinary gonadotropin peptide as acute phase reactant: transient elevation after operation for digestive diseases. (19/2511)

OBJECTIVE: In order to characterize urinary gonadotropin peptide (UGP) as an acute phase reactant, we focused on the UGP levels after surgical operation. DESIGN: Fifty cases of gastrointestinal cancer, 4 cases of cancers of other organs and 13 cases of benign digestive diseases were enrolled into this study. METHODS: UGP levels were measured using an enzyme immunoassay before and after surgery. RESULTS: Fifty-four (80.6%) of the 67 cases studied showed transient elevations of UGP. Both urinary interleukin (IL)-6 and LH levels were also increased transiently in 49 cases (73.1%). All of these three factors were increased in 38 cases (56.7%), and in 32 (84.2%) of these 38 cases, the order of peak appearance was as follows: IL-6, LH, and UGP. The UGP levels in the group of total gastrectomy were significantly higher than those in the group of partial gastrectomy. CONCLUSIONS: These results suggest that UGP shows a transient peak after surgery, correlating with levels of cytokines such as IL-6. UGP may be an acute phase reactant, and its levels are correlated with the grade of surgical stress.  (+info)

Economic comparison of nimesulide and diclofenac, and the incidence of adverse events in the treatment of rheumatic disease in Greece. (20/2511)

In Greece a 15-day treatment of rheumatic disease with diclofenac costs 56% more than treatment with nimesulide. This is due to the lower incidence of gastrointestinal adverse events with nimesulide, and the absence of serious gastrointestinal complications leading to hospitalization, which more than offset the higher acquisition cost of nimesulide. The average saving by using nimesulide instead of diclofenac is about US$21 per patient for a 15-day treatment period.  (+info)

Helicobacter pylori: the Middle East scenario. (21/2511)

A review of Helicobacter pylori in the Middle East is presented. Prevalence studies have been performed in asymptomatic population groups from Algeria, Israel, Saudi Arabia and Turkey. These showed that the prevalence of H. pylori is similar to that of the developing countries of the world with a high level of infection in childhood (40 to 70 percent), which increases with age to 85 to 90 percent. Israel, however, has a low prevalence in children (10 percent), but there is a rapid rise in the second decade of life to 39 percent, reaching 79 percent in those over 60 years old. The prevalence rates were higher in those living in communal settlements (72 percent) than in urban dwellers (65 percent). The infection rates were higher in persons of Mediterranean and Asian origin (89 percent) compared to those of Western European/North American origin (57 percent). The prevalence rate of H. pylori infection in patients undergoing endoscopy for upper gastrointestinal symptoms has now been reported from many Middle Eastern countries, including Egypt, Iran, Israel, Oman, Saudi Arabia, the United Arab Emirates and Yemen. These studies showed that patients with gastritis and peptic ulcer disease had similar rates of infection as reported from Europe, United States and Africa (71 to 92 percent). However, patients with non-ulcer dyspepsia had higher rates of infection (61 to 89 percent). The H. pylori scenario from the prevalence rates, treatment protocols and responses to treatment does not differ very much from other developing areas of the world.  (+info)

The prognostic value of gastrointestinal morbidity for gastric cancer. (22/2511)

OBJECTIVE: A history of gastrointestinal disease is a risk factor for organic gastrointestinal disorders overall. We conducted a retrospective case-control study to explore whether a history of gastrointestinal disease is of prognostic value for gastric cancer. METHODS: Forty-six patients with gastric cancer were identified from a dynamic population of approximately 12,000 patients followed since 1971 in four general practices. The control subjects without gastric cancer were matched one-on-one according to age, general practice, sex and observation period. Data on gastrointestinal morbidity in the period before gastric cancer was diagnosed were obtained from the Continuous Morbidity Registration. RESULTS: The mean observation period between the date of enrolment in the registration and the first diagnosis of gastric carcinoma was 12 years. Although every patient with gastric cancer ultimately will develop gastrointestinal complaints, 28 of these patients had no previous gastrointestinal morbidity, in comparison with 26 control subjects. Furthermore, patients who developed gastric cancer did not have more frequent gastrointestinal morbidity in their past than the control subjects (odds ratio 0.80, 95% CI 0.32-2.03). CONCLUSIONS: Our results suggest that a history of gastrointestinal morbidity is not of prognostic value for gastric cancer. Focusing attention on patients with a past history of gastrointestinal symptoms to detect gastric cancer may be of little value.  (+info)

Gastrointestinal safety and tolerance of ibuprofen at maximum over-the-counter dose. (23/2511)

BACKGROUND: Delineation of non-steroidal anti-inflammatory drug (NSAID) gastrointestinal toxicity has largely depended on retrospective epidemiologic studies which demonstrate that lower doses of NSAIDs pose a lower risk of gastrointestinal toxicity. Ibuprofen, a propionic acid NSAID, has, in most such studies, exhibited a favourable profile in terms of gastrointestinal bleeding. Since 1984, ibuprofen has been available as a non-prescription analgesic/antipyretic with a limit of 1200 mg/day for 10 days of continuous use. Trials and spontaneously reported adverse experiences suggest that gastrointestinal symptoms and bleeding are rare. METHODS: This study prospectively evaluated the gastrointestinal tolerability, as compared to placebo, of the maximum non-prescription dose and duration of ibuprofen use in healthy subjects representative of a non-prescription analgesic user population. RESULTS: Gastrointestinal adverse experiences were similar in the placebo and ibuprofen groups (67 out of 413, 16% with placebo vs. 161 out of 833, 19% with ibuprofen). There was no difference between the two groups in the proportion discontinuing due to a gastrointestinal event. Gastrointestinal adverse experiences reported by >/= 1% of subjects were: dyspepsia, abdominal pain, nausea, diarrhoea, flatulence, and constipation. Seventeen (1.4%) subjects had positive occult blood tests: their frequency was comparable between treatments. CONCLUSIONS: When used as directed to treat episodic pain, non-prescription ibuprofen at the maximum dose of 1200 mg/day for 10 days, is well-tolerated.  (+info)

Polymerase chain reaction based human leucocyte antigen genotyping for the investigation of suspected gastrointestinal biopsy contamination. (24/2511)

BACKGROUND: Mislabelling or contamination of surgical specimens may lead to diagnostic inaccuracy, particularly within gastrointestinal pathology when multiple small mucosal biopsy specimens are commonly taken, and where a tiny fragment of foreign tissue may be indistinguishable from true biopsy material using histological assessment alone. AIMS: To assess the utility of polymerase chain reaction (PCR) based human leucocyte antigen (HLA) genotyping techniques for the investigation of potentially mislabelled or contaminated gastrointestinal biopsy specimens. PATIENTS: Ten cases (28 samples) in which mislabelling or contamination was suspected, comprising four upper gastrointestinal tract biopsies and six colonoscopic biopsy series. METHODS: Direct and nested PCR-sequence specific primer (SSP) based HLA class II genotyping was performed on DNA extracted from formalin fixed and paraffin wax embedded tissue (23 samples) or peripheral blood leucocytes (five samples). RESULTS: A full HLA-DRB1 genotype was determined in all 28 samples. In seven cases the HLA-DRB1 genotype of the putative contaminant was different to that of the corresponding reference tissue, confirming different individual origins for the contaminant and reference material. In one case the contaminant tissue was shown to possess the same HLA-DRB1 alleles as a second patient (probable source). In the remaining three cases the same HLA-DRB1 alleles were detected within the potential contaminant and reference tissues. CONCLUSIONS: PCR based HLA class II genotyping is a valuable tool for investigating potential contamination or mislabelling within gastrointestinal biopsy specimens and this report has confirmed contamination in seven of ten cases studied.  (+info)