Characterization of a hospital-based gastroenteritis outbreak caused by GII.6 norovirus in Jinshan, China.

An acute gastroenteritis (AGE) outbreak caused by a norovirus occurred at a hospital in Shanghai, China, was studied for molecular epidemiology, host susceptibility and serological roles. Rectal and environmental swabs, paired serum samples and saliva specimens were collected. Pathogens were detected by real-time polymerase chain reaction and DNA sequencing. Histo-blood group antigens (HBGA) phenotypes of saliva samples and their binding to norovirus protruding proteins were determined by enzyme-linked immunosorbent assay. The HBGA-binding interfaces and the surrounding region were analysed by the MegAlign program of DNAstar 7.1. Twenty-seven individuals in two care units were attacked with AGE at attack rates of 9.02 and 11.68%. Eighteen (78.2%) symptomatic and five (38.4%) asymptomatic individuals were GII.6/b norovirus positive. Saliva-based HBGA phenotyping showed that all symptomatic and asymptomatic cases belonged to A, B, AB or O secretors. Only four (16.7%) out of the 24 tested serum samples showed low blockade activity against HBGA-norovirus binding at the acute phase, whereas 11 (45.8%) samples at the convalescence stage showed seroconversion of such blockade. Specific blockade antibody in the population played an essential role in this norovirus epidemic. A wide HBGA-binding spectrum of GII.6 supports a need for continuous health attention and surveillance in different settings.

Analysis of the spatiotemporal expression of major genes in the TGF-ß/Smad signaling pathway and correlation analysis using Hu sheep muscle tissue.

The mRNA expression levels of key genes (Smads, MSTN, and MyoG) in the TGF-ß/Smad signaling pathway in Hu sheep at different growth stages (2 days, 2 months, and 6 months of age) and in different skeletal muscles (longissimus dorsi muscle and soleus muscle) and different genders were detected; and correlation of the Smad family (Smad2, Smad3, Smad4, and Smad7), MSTN, MyoG expressions was analyzed in Hu sheep. The results showed that the expression of Smads was higher in the soleus muscle than in the longissimus dorsi muscle; the expressions of Smad2, Smad3, and Smad4 were significantly higher in 2-day-old sheep than in sheep belonging to the other age groups (P < 0.05); the expressions of Smad2, Smad4, and Smad7 were higher in rams than in 2-day-old ewes, but lower in rams than in 2-month-old and 6-month-old ewes; and the expression of Smad3 was higher in rams than in 2-day-old and 2-month-old ewes, but lower in rams than in 6-month-old ewes. In the 2 different muscle tissues, expression of Smad2 was significantly positively correlated (P < 0.01) with that of Smad3. The expression of Smad3 was significantly positively correlated (P < 0.01) with that of Smad4, which showed that the Smad family genes could have an inhibitory effect on the TGF-ß/Smad signaling pathway.

Temporal and spatial expression of Smads and their correlation with YAP1 expression in sheep.

The temporal and spatial patterns of Smad and Yes-associated protein 1 (YAP1) expression were investigated in skeletal muscle (gastrocnemius muscle and extensor digitorum longus) at different growth stages (2 days old, 2 and 6 months old) in Hu sheep. Smads were differentially expressed in sheep skeletal muscle, with high expression in the gastrocnemius muscle and lower expression in the extensor digitorum longus. Expression of Smad2, Smad3, and Smad4 at the 2-day-old stage was significantly higher than at other stages (P < 0.05). The expression of Smad7 in 2-day-old sheep was lower than in 6-month-old sheep, with the lowest levels at 2 months. Smad expression was higher in males than in females at the 2-day-old stage, and expression in 2- and 6-month-old males was lower than that in 2-day-old females. Smad3 expression was higher in the 2-day- and 2-month-old males than in the females. There was a positive correlation (P < 0.01) between YAP1 and Smad2 expression in gastrocnemius muscle at the 2-month-old stage. YAP1 and Smad4/7 expression were positively correlated (P < 0.01) in extensor digitorum longus at the 2-day-old stage. YAP1 expression was negatively correlated with Smad7 in the extensor digitorum longus at 6 months. A significant difference between Smad2 and Smad3 (P < 0.01) expression in muscle was observed, consistent with Smad3 and Smad4 expression, indicating that these inhibit transforming growth factor-ß signaling in the same way. There was a positive correlation (P < 0.01) between YAP1 and MSTN expression, suggesting that YAP1 participates in muscle growth in sheep.

Prognostic characteristics of duodenal gastrointestinal stromal tumours.

BACKGROUND: This study evaluated the clinical characteristics, surgical procedures and prognosis of duodenal gastrointestinal stromal tumours (GISTs). METHODS: Patients with a diagnosis of primary duodenal GIST treated between January 2000 and December 2012 were analysed. Patients with gastric and small intestinal GISTs were chosen as control groups according to the following parameters: age, tumour size, mitotic index and adjuvant imatinib therapy. Operative procedures for patients with duodenal GIST included pancreaticoduodenectomy or limited resection. Disease-free survival (DFS) was calculated using Kaplan-Meier analysis. RESULTS: Some 71 patients with duodenal, 71 with gastric and 70 with small intestinal GISTs were included in the study. DFS of patients with duodenal GIST was shorter than that of patients with gastric GIST (3-year DFS 84 versus 94 per cent; hazard ratio (HR) 3.67, 95 per cent c.i. 1.21 to 11.16; P = 0.014), but was similar to that of patients with small intestinal GIST (3-year DFS 84 versus 81 per cent; HR 0.75, 0.37 to 1.51; P = 0.491). Patients who underwent pancreaticoduodenectomy were older, and had larger tumours and a higher mitotic index than patients who had limited resection. The 3-year DFS was 93 per cent among patients who had limited resection compared with 64 per cent for those who underwent PD (HR 0.18, 0.06 to 0.59; P = 0.001). CONCLUSION: The prognosis of duodenal GISTs is similar to that of small intestinal GISTs.

Cryptostatin, a chagasin-family cysteine protease inhibitor of Cryptosporidium parvum.

Cysteine proteases of pathogenic protozoan parasites play pivotal roles in the life cycle of parasites, but strict regulation of their activities is also essential for maintenance of parasite physiology and interaction with hosts. In this study, we identified and characterized cryptostatin, a novel inhibitor of cysteine protease (ICP) of Cryptosporidium parvum. Cryptostatin showed low sequence identity to other chagasin-family ICPs, but 3 motifs (NPTTG, GXGG, and RPW/F motifs), which are evolutionarily conserved in chagasin-family ICPs, were found in the sequence. The overall structure of cryptostatin consisted of 8 ß-strands that progressed in parallel and closely resembled the immunoglobulin fold. Recombinant cryptostatin inhibited various cysteine proteases, including papain, human cathepsin B, human cathepsin L, and cryptopain-1, with K i's in the picomolar range. Cryptostatin was active over a wide pH range and was highly stable under physiological conditions. The protein was thermostable and retained its inhibitory activity even after incubation at 95°C. Cryptostatin formed tight complexes with cysteine proteases, so the complexes remained intact in the presence of sodium dodecyl sulfate and ß-mercaptoethanol, but they were disassembled by boiling. An immunogold electron microscopy analysis demonstrated diffused localization of cryptostatin within oocystes and meronts, but not within trophozoites, which suggests a possible role for cryptostatin in host cell invasion by C. parvum.

Anti-F(ab')2 antibodies in thrombocytopenic patients at risk for acquired immunodeficiency syndrome.

22 homosexual or narcotic addict patients at risk for acquired immunodeficiency syndrome (AIDS) or with AIDS, were studied for the presence of antiimmunoglobulin antibodies and circulating immune complexes (20 were thrombocytopenic, 6 had AIDS). Circulating immune complex levels were 10-fold higher than levels in normal subjects. IgG anti-F(ab')2 antibodies were noted in homosexual as well as narcotic addict patients. Of 16 homosexual patients, 7 had IgG anti-F(ab')2 antibody of moderate to marked titer with broad reactivity against autologous, homologous, and control F(ab')2 fragments. Three others demonstrated limited reactivity against one or two F(ab')2 fragments. The remaining six patients were negative. Six of six narcotic addict patients had IgG anti-F(ab')2 antibody, five with limited reactivity, one with broad reactivity. In contrast, neither elevated circulating immune complexes nor anti-F(ab')2 antibodies were detectable in six autoimmune thrombocytopenic patients. Anti-F(ab')2 antibody could be affinity purified from serum or circulating immune complexes. Anti-F(ab')2 reactivity correlated with circulating immune complex levels, r = 0.83, P less than 0.01.

Calreticulin, a calcium-binding molecular chaperone, is required for stress response and fertility in Caenorhabditis elegans.

Calreticulin (CRT), a Ca(2+)-binding protein known to have many cellular functions, including regulation of Ca(2+) homoeostasis and chaperone activity, is essential for heart and brain development during embryogenesis in mice. Here, we report the functional characterization of Caenorhabditis elegans calreticulin (crt-1). A crt-1 null mutant does not result in embryonic lethality but shows temperature-dependent reproduction defects. In C. elegans CRT-1 is expressed in the intestine, pharynx, body-wall muscles, head neurons, coelomocytes, and in sperm. crt-1 males exhibit reduced mating efficiency and defects late in sperm development in addition to defects in oocyte development and/or somatic gonad function in hermaphrodites. Furthermore, crt-1 and itr-1 (inositol triphosphate receptor) together are required for normal behavioral rhythms. crt-1 transcript level is elevated under stress conditions, suggesting that CRT-1 may be important for stress-induced chaperoning function in C. elegans.

High prevalence of Gymnophalloides seoi infection in a village on a southwestern island of the Republic of Korea.

Gymnophalloides seoi (Digenea: Gymnophallidae), a new human intestinal trematode reported from a Korean woman who complained of epigastric discomfort, has been shown to be highly prevalent among the villagers of a southwestern island of the Republic of Korea. For the detection of human infections, fecal examinations were conducted on the inhabitants of a seashore village, where the first patient with a G. seoi infection had resided. Of 98 inhabitants examined, 70 (71.4%) were infected with various intestinal parasites; among them, G. seoi showed the highest rate of egg positivity 48 of 98 (49.0%). Individual worm burdens of G. seoi, as measured by collection of adult flukes after anthelmintic treatment and purgation, ranged from 106 to 26,373 specimens (average per infected case = 3,326). There was no sex-related difference in the prevalence of G. seoi, and the age distribution of the infected cases showed a relatively even pattern. This study confirms that human infection by G. seoi is not an incidental one and provides the first evidence of its high prevalence on this Korean island.

Chronic bombesin treatment increased the [3H]spiperone binding, glutamate decarboxylase and choline acetyltransferase activity in the rat brain.

The effects of chronic bombesin (BBS) on [3H]spiperone (SPD) binding activity, choline acetyltransferase (ChAT), acetylcholinesterase (AChE) and glutamate decarboxylase (GAD) were investigated in the rat brain corpus striatum (CS). The chronic i.p. administration of BBS to rats increased: (1) the specific [3H]SPD binding to the striatal Pm (plasma membrane) (16%, P less than 0.03 and 34%, P less than 0.008 at 5 micrograms/kg respectively), (2) the specific GAD activity in the CS by 52% (5 micrograms/kg, n.s.) and 46% (10 micrograms/kg, P less than 0.05) respectively, (3) the specific ChAT activity in the CS by 54% (10 micrograms/kg, P less than 0.002), and (4) the specific AChE activity by 23% (10 micrograms/kg, P less than 0.02) after 14 days. It increased only: (1) the specific [3H]SPD binding by 29% (P less than 0.001, at 10 micrograms/kg) and (2) the specific GAD activity by 23% (P less than 0.015, 10 micrograms/kg), after 7 days. Neither ChAT nor AChE activity was affected after 7 days treatment of BBS at 10 micrograms/kg. In vitro study showed that BBS at 0.2 microM did not affect any of the neurochemical parameters examined in the CS. Thus, the changes in brain chemistry caused by chronic BBS were not due to direct effects of BBS but may be mediated through its metabolites or CCK release. Data indicate that the central effects of peripherally administered BBS are dependent on both the duration and the dosage of the drug treatment and that the dopaminergic and GABAergic systems seem to be more vulnerable to chronic BBS than the cholinergic system in the rat brain CS.(ABSTRACT TRUNCATED AT 250 WORDS)

Strength and stability of posterior lumbar interbody fusion. Comparison of titanium fiber mesh implant and tricortical bone graft.

STUDY DESIGN: A paired comparison was done of the bending flexibility and compression strength of tricortical bone graft and titanium fiber mesh implants in a human cadaver model of posterior lumbar interbody fusion. OBJECTIVES: To test the hypothesis that a titanium fiber mesh implant and a tricortical bone graft provide adequate and equal mechanical strength and stability in posterior lumbar interbody fusion constructs. SUMMARY OF BACKGROUND DATA: Although studies of posterior lumbar interbody fusion constructs have been performed, the authors are unaware of any study in which the strength and stability of a titanium fiber mesh implant are compared with those of tricortical bone graft for posterior lumbar interbody fusion in the human cadaver lumbar spine. METHODS: Changes in neutral zone and range of motion were measured in a bending flexibility test before and after placement of posterior lumbar interbody fusion constructs. Tricortical bone graft and titanium fiber mesh implant construct stability than were compared in a paired analysis. The constructs than were loaded to failure to evaluate construct strength as a function of graft material and bone mineral density. RESULTS: The posterior lumbar interbody fusion procedure produced statistically significant decreases in neutral zone when compared with the intact spine. No statistically significant differences in neutral zone, range of motion, or strength were detected between the two implants. Construct strength correlated strongly with bone mineral density. CONCLUSIONS: Posterior lumbar interbody fusion procedures result in equal or improved acute stability for titanium fiber mesh implants and tricortical bone graft implants when used without additional posterior stabilization.

The role of imaging and in situ biomechanical testing in assessing pedicle screw pull-out strength.

STUDY DESIGN: This study determined the predictive ability of quantitative computed tomography, dual energy x-ray absorptiometry, pedicular geometry, and mechanical testing in assessing the strength of pedicle screw fixation in an in vitro mechanical test of intra-pedicular screw fixation in the human cadaveric lumbar spine. OBJECTIVE: To test several hypotheses regarding the relative predictive value of densitometry, pedicular geometry, and mechanical testing in describing pedicle screw pull-out. SUMMARY OF BACKGROUND DATA: Previous investigations have suggested that mechanical testing, geometry, and densitometry, determined by quantitative computed tomography or dual energy x-ray absorptiometry, predict the strength of the screw-bone system. However, no study has compared the relative predictive value of these techniques. METHODS: Forty-nine pedicle screw cyclic-combined flexion-extension moment-axial pull-out tests were performed on human cadaveric lumbar vertebrae. The predictive ability of quantitative computed tomography, dual energy x-ray absorptiometry, insertional torque, in situ stiffness, and pedicular geometry was assessed using multiple regression. RESULTS: Several variables correlated to force at failure. However, multiple regression analysis showed that bone mineral density of the pedicle determined by quantitative computed tomography, insertional torque, and in situ stiffness when used in combination resulted in the strongest prediction of pull-out force. No other measures provided additional predictive ability in the presence of these measures. CONCLUSIONS: Pedicle density determined by quantitative computed tomography when used with insertional torque and in situ stiffness provides the strongest predictive ability of screw pull-out. Geometric measures of the pedicle and density determined by dual energy x-ray absorptiometry do not provide additional predictive ability in the presence of these measures.

Biomechanics of the Bankart repair: the relationship between glenohumeral translation and labral fixation site.

The specific aim of this study was to quantify glenohumeral translations in cadaveric shoulders after repair of the superior and middle regions of a surgically created Bankart lesion and after repair of the superior, middle, and inferior regions of the same lesion. Anterior-posterior, superior-inferior, and medial-lateral translations in nine cadaveric specimens were tested with shoulders in 0 degree, 45 degrees, and 90 degrees of humeral abduction and varying degrees of humeral rotation. There was statistically significantly less anterior and inferior translation after three-site labral repair compared with after two-site labral repair, and this effect was greatest at 90 degrees of glenohumeral abduction. The decreased translations demonstrated with three-site repair emphasized the importance of careful repair of the labrum to the inferior glenoid rim during a Bankart reconstruction and suggested that failure to do so may be a contributing factor to recurrent instability after anterior shoulder reconstruction.

The effect of gamma-irradiation on the viability of Cryptosporidium parvum.

Cryptosporidium parvum is 1 of the major causative organisms in waterborne diarrheal illness. Not only does C. parvum spread ubiquitously in our environment, it is also highly resistant to harsh environmental conditions and disinfectants. Therefore, a control measure for this protozoon is urgently required. This study investigated the effect of gamma-irradiation, in the range of 1,000-50,000 Gy, on the viability of C. parvum oocysts. Oocyst viability was determined by a combined indirect immunofluorescence and nucleic acid staining and animal infectivity study. The proportion of viable oocysts estimated by nucleic acid staining ranged from 94.2 to 89.4% in the 0- to 10,000-Gy groups, whereas it was reduced significantly to 58.6 or 45.7% in the 25,000- or 50,000-Gy group, respectively, at 24 hr postirradiation. In an animal infectivity study, oocysts irradiated with less than 10,000 Gy induced infections in mice wherein there were low numbers of oocysts per gram of feces amounting to 8-10.8% of the values in control mice, whereas with 50,000 Gy-irradiated oocysts, no oocysts were produced in the mice. This study suggests that at least 50,000 Gy of gamma-irradiation is necessary for the complete elimination of oocyst infectivity in mice.

Evaluation of fracture predilection in the calcaneus after external fixator pin removal.

OBJECTIVES/HYPOTHESIS: External fixators have been advocated for the treatment of intra-articular fractures of the distal tibia, so-called "pilon" or "plafond" fractures. Current recommendations include placement of external fixator pins, which vary in diameters up to six millimeters, in the talus and calcaneus. Removal of a relatively large pin may create a large defect in the bone, theoretically increasing fracture predilection with weight bearing. The objective was to compare the compressive load at failure of intact and formerly instrumented calcanei. It was hypothesized that the pin hole defect would not lead to a clinically significant difference in compressive load at failure. STUDY DESIGN: A biomechanical evaluation of randomized matched pairs of cadaveric calcanei. METHODS: Fresh human calcanei were harvested, embedded in casting compound, and tested pairwise. Among pairs of calcanei, one served as the control, and the other was drilled with a 6.0-mm pin in the posterior portion. The pin was removed before biomechanical evaluation. Testing was performed in compression under displacement control on a hydraulic materials testing system. RESULTS: There was a 22% reduction in compressive load at failure (p = 0.021) of the drilled versus intact specimens. Compared with intact calcanei, defect calcanei had a compressive failure load much closer to forces that might be encountered with walking and running. CONCLUSIONS: The six-millimeter-pin defect is a significant stress riser, and protected, progressive weight bearing after pin removal should be recommended.

[Surface ultrastructure of Parvatrema timondavidi (Digenea: Gymnophallidae) according to its developmental stages].

Surface ultrastructure of Parvatrema timondavidi developmental stages was studied using a scanning electron microscope. The metacercariae were collected from the marine clam. Tapes philippinarum, and juvenile and adult worms were recovered at 1, 2, 3 and 7 days after experimental infection of mice. The metacercariae had a large oral sucker and characteristic lateral projections. Around the lip of the oral sucker many type I and type II sensory papillae were observed, and type III papillae were located symmetrically on the medial side of the lateral projection. Numerous type I papillae were grouped around the genital pore. The tegumental spines were distributed over the worm surface except the lip of the suckers and genital pore. The 1-day old worm had a well-developed ventral sucker, with 6 type II sensory papillae on its outer surface and another 6 type I papillae on the inner side. Two small type I papillae were seen on the anterior side of the ventral sucker. The genital pore was small and opened separately from the ventral sucker and 15 type I papillae were grouped around it. The 2-, 3-, and 7-day worms revealed that as they grew to be adults, the spine tips became multipointed, the genital pore formed a genital atrium, and the cytoplasmic process became well differentiated. In 2- and 3-day worms 10 type II papillae encircling the lip of the oral sucker, and additional 4 papillae at the dorsal side of 4 dorsal type II papillae were a characteristic feature. The distribution pattern of sensory papillae around the oral sucker and genital pore, and 2 type I papillae on the anterior side of the ventral sucker, was so peculiar in P. timondavidi, that they seem to be useful keys for taxonomic differentiation from other gymnophallids.

[Preventive effect of bombesin on alloxan-induced diabetes in rat].

The effect of bombesin against injury on rat islet B cells was studied in three kinds of experiments: (1). In vivo experiment, it was found that preinjection of bombesin (50 micrograms/kg, sublingual v.) could effectively prevent an increase of plasma glucose and decrease of plasma insulin in diabetic rat induced by alloxan (200 mg/kg, s.c.) (2). In vitro experiment, isolated pancreas perfusion showed that alloxan-induced (14 mmol/L) perfusion fluid inhibition of insulin secretion could be reversed by pretreatment of bombesin (10(-3) mmol/L). (3). Investigation on isolated and incubated islets demonstrated that alloxan induced decrease of insulin and somatostatin secretion and increase of glucagon secretion could be prevented by bombesin. The above-mentioned results suggest that bombesin may play an important role in the regulation of plasma glucose in diabetic rat and have a potent preventive effect against the development of diabetes.

[Effects of intracerebroventricular injections of thyrotropin releasing hormone on gastrointestinal propulsive motility in rats].

The effect of intracerebroventricular (ICV) injections of thyrotropin releasing hormone (TRH) on the propulsive motility of the gastrointestinal tract was examined in rats. The distance travelled by charcoal meal through the small intestine, measured in terms of percentage of its total length, was recorded as the index of propulsive motility. The results were as follows: (1) The propulsive distance of charcoal meal was significantly reduced in a dose-dependent manner after ICV injections of TRH (1 microgram/10 microliters, 5 micrograms/10 microliters or 10 micrograms/10 microliters) (P less than 0.01-0.001) The effects were abolished by injection of atropine (5 micrograms/10 microliters ICV). (2) The gastrointestinal propulsive motility decreased markedly (P less than 0.01) after injection of a larger dose of TRH (50 micrograms/100 g) into the hypodermis. The effects were not completely blocked by subcutaneous injections of propranolol (5 mg/kg). (3) No effects (P greater than 0.05) were found on the inhibition of gastrointestinal propulsive motility after ICV injections of regitine (2.5 mg/kg im, 50 micrograms/50 microliters ICV) or propranolol (5 mg/kg im, 50 micrograms/50 microliters ICV). The results indicate that TRH has an inhibitory effect on the propulsive motility of gastrointestinal tract, which may be mediated via the non-adrenergic inhibitory nerve of the vagal nerves.

[Protective effect of indomethacin on alloxan-induced diabetes in rat].

Changes of concentration of serum glucose, insulin and glucagon induced by preadministration of indomethacin were observed in normal rats and diabetic rats induced by alloxan. The results demonstrated that the level of serum glucose in diabetic rats was lowered significantly after preadministration of indomethacin (10 mg/kg) dose-dependently. After preadministration of 5, 10, 15 mg/kg of indomethacin the level of serum glucose 48 h after injecting alloxan was decreased from the control value of 591.5 +/- 38.2 mg% to 559.1 +/- 53.2, 436 +/- 16.6 and 266.6 +/- 29.9 mg% respectively. The concentration of serum insulin was increased from the control 10.5 +/- 2.7 microU/ml to 31.9 +/- 7.0 microU/ml and glucagon from 550.0 +/- 27.0 pg/ml to 303.1 +/- 22.9 pg/ml after preadministration of 10 mg/kg indomethacin. Histologic observation showed that alloxan induced beta cell lesion in pancreatic islet could indeed be prevented by indomethacin to a significant extent.

[Protective effect of interleukin-1 beta on acetaminophen induced liver damage in mice].

In the model of liver damage induced by acetaminophen of mice, injection of interleukin-1 beta (IL-1 beta, i.p. 50,000 U/kg) 1, 6 or 12 h before the administration of acetaminophen could reduce the leakages of GPT and GOT induced by acetaminophen, with the 12 h pretreatment being the most effective. Treatment with IL-1 beta 1 h after administration of acetaminophen had no effect. Treatment with IL-1 beta of different doses (10,000, 30,000 or 50,000 U/kg) 12 h before the administration of acetaminophen could reduce the leakages of transaminases in a dose dependent manner and decrease the mortality of mice. The protective effect of IL-1 beta on the liver could be abolished by IL-1 beta receptor antagonist. Further experiments showed that IL-1 beta could increase the content of reduced glutathione (GSH) in normal liver and reverse the decline of GSH and the increase of GSSG induced by acetaminophen. IL-1 beta could also reduce malondiadehyde (MDA) content enhanced by acetaminophen. The above results indicate that the preventive effect of IL-1 beta against liver damage due to acetaminophen may be mediated through IL-1 beta receptor by increasing glutathione synthesis and decreasing lipid peroxidation of the liver.

[The protective effect of IL-1 beta on stress-induced gastric mucosal damage in rat].

The effect of recombinant IL-1 beta on stress-induced gastric mucosal lessions was studied in rats. Pretreatment with IL-1 beta prevented formation of gastric mucosal damage in a dose-dependent manner. IL-1 receptor antagonist peptide (IRAP) could totally reverse the protective effect of IL-1 beta. IL-1 fragment peptide (163-171) had no effect on gastric ulcer formation in the experimental model, whereas sulfhydryl blocker N-ehtylmaleimide partially blocked the protective effect of IL-1 beta. The concentration of protein and noneprotein sulfhydryls in the gastric mucosa was significantly decreased 3 h after stress, and this decrease was partially prevented by IL-1 beta. IL-1 beta also decreased the concentration of molondialdehyde (MDA) in the gastric mucosa after 3 h stress. The results suggest that IL-1 beta could effectively lessen the degree of stress-induced gastric mucosal damage, due possibly to the production of endogenous sulfhydryl compounds in the gastric mucosa.