Comprehensive analysis of gastrointestinal side effects in COVID-19 patients undergoing combined pharmacological treatment with azithromycin and hydroxychloroquine: a systematic review and network meta-analysis.

During the COVID-19 pandemic, several drugs were repositioned and combined to quickly find a way to mitigate the effects of the infection. However, the adverse effects of these combinations on the gastrointestinal tract are unknown. We aimed investigate whether Hydroxychloroquine (HD), Azithromycin (AZ), and Ivermectin (IV) used in combination for the treatment of COVID-19, can lead to the development of gastrointestinal disorders. This is a systematic review and network meta-analysis conducted using Stata and Revman software, respectively. The protocol was registered with PROSPERO (CRD42023372802). A search of clinical trials in Cochrane Library databases, Embase, Web of Science, Lilacs, PubMed, Scopus and Clinicaltrials.gov conducted on November 26, 2023. The eligibility of the studies was assessed based on PICO criteria, including trials that compared different treatments and control group. The analysis of the quality of the evidence was carried out according to the GRADE. Six trials involving 1,686 COVID-19 patients were included. No trials on the association of HD or AZ with IV met the inclusion criteria, only studies on the association between HD and AZ were included. Nausea, vomiting, diarrhea, abdominal pain and increased transaminases were related. The symptoms of vomiting and nausea were evaluated through a network meta-analysis, while the symptom of abdominal pain was evaluated through a meta-analysis. No significant associations with these symptoms were observed for HD, AZ, or their combination, compared to control. Low heterogeneity and absence of inconsistency in indirect and direct comparisons were noted. Limitations included small sample sizes, varied drug dosages, and potential publication bias during the pandemic peak. This review unveils that there are no associations between gastrointestinal adverse effects and the combined treatment of HD with AZ in the management of COVID-19, as compared to either the use of a control group or the administration of the drugs individually, on the other hand, highlighting the very low or low certainty of evidence for the evaluated outcomes. To accurately conclude the absence of side effects, further high-quality randomized studies are needed.

Vaccine adherence and adverse events of the SARS-COV vaccine in patients with inflammatory bowel disease.

OBJECTIVE: To assess adherence to and the adverse effects of the SARS-COV vaccine in patients with inflammatory bowel disease (IBD). PATIENTS AND METHODS: This is an observational, analytical, cross-sectional study. Sociodemographic and clinical data, SARS-COV vaccine data, medications for IBD with use during the vaccination period, and adverse events during the vaccination period were collected. Carried out logistic regressions with robust variance estimation to estimate the odds ratio with the respective 95% confidence intervals (95%CI) to assess the factors associated with non-serious adverse effects following vaccine doses as outcome variables. RESULTS: 194 patients participated, with vaccine compliance of 78.3% for three doses of any vaccine (n=152). Local symptoms and mild systemic symptoms predominated, regardless of the type of vaccine. The first dose of the SARS-COV vaccine with AstraZeneca had a higher percentage of patients with vaccine symptoms. AstraZeneca vaccine increased the chance of non-serious adverse effects in IBD patients by 2.65 times (95% CI: 1.38-5.08; p=0.003), regardless of age, gender, physical activity, excess weight, use of disease-modifying drugs, immunobiological and corticosteroids. CoronaVac vaccine was associated with asymptomatic patients at the first dose and reduced the chance of adverse effects by 0.28 times (OR: 0.284; 95%CI: 0.13-0.62; p=0.002). CONCLUSION: Local symptoms and mild systemic symptoms predominated, regardless of the type of vaccine. Using CoronaVac in the first dose reduced the chances of adverse effects, while AstraZeneca increased the risk of adverse effects.

Gastroduodenal Symptoms in Inflammatory Bowel Disease Are Correlated with Gastric Emptying and Serum Levels of Active Ghrelin.

BACKGROUND: Inflammatory bowel disease (IBD) is associated with delay in gastric emptying, increase in ghrelin, and decrease in leptin. The aim was to investigate the correlation between gastroduodenal (GD) symptoms, gastric emptying, and serum levels of active ghrelin and leptin in IBD. Twenty-seven IBD patients and 26 healthy volunteers were asked to complete the Porto Alegre Dyspeptic Symptoms Questionnaire. A gastric emptying test for solids was performed using a C13 octanoic acid breath test. During this test, serum samples were collected for measuring active ghrelin and leptin concentrations by radioimmunoassay. SUMMARY: Patients with IBD demonstrated delayed gastric emptying compared with healthy volunteers. In patients with GD symptoms, the delay in gastric emptying was more pronounced, and there were significant correlations of satiety and vomiting with gastric emptying. Basal leptin, but not active ghrelin, increased in patients with GD symptoms compared with patients without these symptoms. There were negative correlations between basal active ghrelin with total Porto Alegre score and epigastric pain in IBD patients with GD symptoms. Key Messages: In IBD, satiety and vomiting were associated with delay in gastric emptying. Conversely, epigastric pain had a negative correlation with active ghrelin. Our results suggest that different pathophysiological mechanisms contribute to GD symptoms in IBD.

Heme oxygenase-1/biliverdin/carbon monoxide pathway downregulates hypernociception in rats by a mechanism dependent on cGMP/ATP-sensitive K+ channels.

OBJECTIVE AND DESIGN: To investigate the role of heme oxygenase-1 (HO-1), carbon monoxide (CO), and biliverdin (BVD) in the zymosan-induced TMJ arthritis in rats. MATERIALS AND METHODS: Mechanical threshold was assessed before and 4 h after TMJ arthritis induction in rats. Cell influx, myeloperoxidase activity, and histological changes were measured in the TMJ lavages and tissues. Trigeminal ganglion and periarticular tissues were used for HO-1, TNF-α, and IL-1ß mRNA time course expression and immunohistochemical analyses. Hemin (0.1, 0.3, or 1 mg kg-1), DMDC (0.025, 0.25, or 2.5 µmol kg-1), biliverdin (1, 3, or 10 mg kg-1), or ZnPP-IX (1, 3 or 9 mg kg-1) were injected (s.c.) 60 min before zymosan. ODQ (12.5 µmol kg-1; s.c.) or glibenclamide (10 mg kg-1; i.p.) was administered 1 h and 30 min prior to DMDC (2.5 µmol kg-1; s.c), respectively. RESULTS: Hemin (1 mg kg-1), DMDC (2.5 µmol kg-1), and BVD (10 mg kg-1) reduced hypernociception and leukocyte migration, which ZnPP (3 mg kg-1) enhanced. The effects of DMDC were counteracted by ODQ and glibenclamide. The HO-1, TNF-α, and IL-1ß mRNA expression and immunolabelling increased. CONCLUSIONS: HO-1/BVD/CO pathway activation provides anti-nociceptive and anti-inflammatory effects on the zymosan-induced TMJ hypernociception in rats.

Dual effect of silymarin on experimental non-alcoholic steatohepatitis induced by irinotecan.

Irinotecan-based regimens are commonly used for treatment of colorectal cancer, which is limited by mucositis and non-alcoholic steatohepatitis (NASH). Silymarin (SIL) prevents fatty liver disease in the clinical setting and in models of liver damage induced chemically. This study investigated the possible effect of SIL on irinotecan (IRI)-induced NASH. Swiss female mice were injected with saline (SAL 5ml/kg i.p.), IRI (50mg/kg i.p.), SIL (150mg/kg p.o.) or IRI (50mg/kg i.p.)+(SIL 1.5, 15 or 150mg/kg p.o.) thrice/week/7weeks. On the seventh week, blood samples were collected for transaminases assay and livers were collected for histopathology, measurement of the total lipids, malondyadehyde (MDA), non-protein sulfhydryl groups (NPSH), cytokines (IL-1ß, IL 6 and IL-10), 3-nitrotyrosine (N-Tyr) and toll-like receptor 4 (TLR4) immunoexpression, quantification of NF-kB, α-smooth muscle actin (α-SMA), and Escherichia coli 16S rRNA gene (RRS) expression. IRI increased liver transaminases, neutrophil infiltration, lipid accumulation, MDA, IL-1ß and IL-6 levels, N-Tyr and TLR4 immunostaining, NF-kB, α-SMA expression and RRS versus the SAL group (p<0.05). Additionally, SIL (1.5mg/kg) improved these parameters (p<0.05), except neutrophil infiltration and RSS versus the IRI group. Furthermore, the SIL (15mg/kg) only improved the inflammatory parameters, the expression of α-SMA and RRS versus the IRI group (p<0.05). The higher dose of SIL (150mg/kg) was even more deleterious than the intermediate dose. Therefore, silymarin showed a dual effect on liver damage induced by IRI. Hepatoprotection seems to involve the inhibition of oxidative stress and protein nitrosylation, preventing activation of hepatic fibrosis mechanisms.

Nitric Oxide and Hydrogen Sulfide Interact When Modulating Gastric Physiological Functions in Rodents.

AIM: The objective was to evaluate the effects of nitric oxide (NO) and hydrogen sulfide (H2S) donors and possible interactions between these two systems in modulating gastric function. METHODS: Mice received saline, sodium nitroprusside (SNP), or sodium hydrosulfite (NaHS), and after 1 h, the animals were killed for immunofluorescence analysis of CSE or eNOS expressions, respectively. Other groups received saline, SNP, NaHS, Lawesson's reagent (H2S donor), PAG + SNP, L-NAME, L-NAME + NaHS, or L-NAME + Lawesson's reagent. Then, the gastric secretions (mucous and acid), gastric blood flow, gastric defense against ethanol, and gastric motility (gastric emptying and gastric contractility) were evaluated. RESULTS: SNP and NaHS increased the expression of CSE or eNOS, respectively. SNP or Lawesson's reagent did not alter gastric acid secretion but increased mucus production, and these effects reverted with PAG and L-NAME treatment, respectively. SNP or NaHS increased gastric blood flow and protected the gastric mucosa against ethanol injury, and these effects reverted with PAG and L-NAME treatments, respectively. SNP delayed gastric emptying when compared with saline, and PAG partially reversed this effect. NaHS accelerate gastric emptying, and L-NAME partially reversed this effect. SNP and NaHS alone induced gastric fundus and pylorus relaxation. However, pretreatment with PAG or L-NAME reversed these relaxant effects only in the pylorus but not in the gastric fundus. CONCLUSION: NO and H2S interact in gastric physiological functions, and this "cross-talk" is important in the control of mucus secretion, gastric blood flow, gastric mucosal defense, and gastric motility, but not in the control of basal gastric acid secretion.

Colitis generates remote antinociception in rats: the role of the L-arginine/NO/cGMP/PKG/KATP pathway and involvement of cannabinoid and opioid systems.

OBJECTIVE AND DESIGN: The aim of this study was to investigate the possible involvement of the NO/cGMP/PKG/KATP+ pathway, cannabinoids and opioids in remote antinociception associated with 2,4,6-trinitrobenzene sulph onic acid (TNBS)-induced colitis. METHODS: TNBS-induced colitis was induced by intracolonic administration of 20 mg of TNBS in 50% ethanol. After induction, carrageenan (500 µg/paw) or prostaglandin (PG) E2 (100 ng/paw) was injected in the rat's plantar surface and hypersensitivity was evaluated by the electronic von Frey test. Rats were pre-treated with L-Noarg one hour before carrageenan injection. L-Arginine was given 10 min before L-Noarg injections. ODQ, KT 5823, glibenclamide (Glib), naloxone and AM 251 or AM 630 were administered 30 min prior to carrageenan or PGE2 treatments. RESULTS: Colitis induction by TNBS reduced PGE2 or carrageenan-induced hypersensitivity. Antinociception produced by TNBS-induced colitis was reversed significantly (P<0.05) by L-Noarg, ODQ, KT 5823, glibenclamide, naloxone, AM251 and AM630 treatments. CONCLUSIONS: TNBS-induced colitis causes antinociception in the rat paw. This disorder appears to be mediated by activation of the NO/cGMP/PKG/KATP pathway, endocannabinoids and endogenous opioids. This information may contribute to a better understanding of peripheral neurological dysfunctions occurring in Crohn's disease.

A MEDICAL AND NEUROPSYCHIATRIC MANAGEMENT SURVEY IN A BRAZILIAN COHORT OF PATIENTS WITH INFLAMMATORY BOWEL DISEASE (IBD).

BACKGROUND: Inflammatory bowel disease (IBD) can be accompanied by several neurological disorders. Since 2004, we started a Brazilian cohort to assess neuropsychiatric complications in IBD patients. Changes in therapeutic strategy and differences in the prevalence and relevance of neuropsychiatric disorders have been reported in the literature. We conducted a short patient-reported survey about the medical management of IBD (with a special focus on neuropsychiatric management) and its complications. During the enrollment period (9/1/2021 to 8/31/2022), 279 patients with IBD answered the survey (128 patients with ulcerative colitis and 151 with Crohn's disease). This is the first medical management survey aimed to verify the level of perception of IBD patients about their neuropsychiatric conditions. We found a high prevalence of neurologic (59%), psychiatric (32%), and neuropsychiatric co-morbidities (69%). There is a marked discrepancy between the findings of neurological disorders reported in our studies over the first 10 years of the cohort in comparison with the current perception/knowledge among the patients registered in the present management survey. Patients tend to have a better understanding of central rather than peripheral nerve conditions. BACKGROUND: • What is already known? BACKGROUND: • The prevalence and spectrum of neuropsychiatric co-morbidities varies among different epidemiologic studies. BACKGROUND: • What is new here? BACKGROUND: • Patients self report a high percentage of neuropsychiatric diseases but tend to better recognize central rather than peripheral nervous system disorders. BACKGROUND: • How can this study help patient care? BACKGROUND: • This study may guide practioners to educate IBD patients about their neuropsychiatric co-morbidities.

A polyphenol-rich açaí seed extract protects against 5-fluorouracil-induced intestinal mucositis in mice through the TLR-4/MyD88/PI3K/mTOR/NF-κBp65 signaling pathway.

Açaí seed extract (ASE) is obtained from Euterpe oleracea Mart. (açaí) plant (Amazon region) has high nutritional and functional value. ASE is rich in polyphenolic compounds, mainly proanthocyanidins. Proanthocyanidins can modulate the immune system and oxidative stress by inhibiting the toll-like receptor-4 (TLR-4)/myeloid differentiation primary response 88 (MyD88)/nuclear factor-κB (NF-κB) pathway. A great deal of evidence suggests that inflammatory cytokines and oxidative stress contribute to the pathogenesis of intestinal mucositis, and these events can lead to intestinal dysmotility. We hypothesized that ASE acts as an anti-inflammatory and antioxidant compound in intestinal mucositis induced by 5-fluorouracil (5-FU) through modulation of the TLR-4/MyD88/phosphatidylinositol-3-kinase α/mechanistic target of rapamycin/NF-κBp65 pathway. The animals were divided into linear 5-FU (450 mg/kg) and 5-FU + ASE (10, 30, and 100 mg/kg) groups. The weight loss of the animals was evaluated daily. Samples from duodenum, jejunum, and ileum were obtained for histopathological, biochemical, and functional analyses. ASE reduced weight loss, inflammatory parameters (interleukin-1ß; tumor necrosis factor-α; myeloperoxidase activity) and the gene expression of mediators involved in the TLR-2/MyD88/NF-κB pathway. ASE prevented histopathological changes with beneficial effects on gastrointestinal transit delay, gastric emptying, and intestinal absorption/permeability. In conclusion, ASE protects the integrity of the intestinal epithelial barrier by inhibiting the TLR/MyD88/PI3K/mechanistic target of rapamycin/NF-κBp65 pathway.

Exploring the clinical relevance of "Angico Gum": an effective biopolymer for topical protection of oesophageal mucosa in gastroesophageal reflux disease patients.

OBJECTIVES: Angico gum (AG) (Anadenanthera colubrina var. Cebil [Griseb.] Altschul) is utilized by some Brazilian communities to alleviate symptoms from gastroesophageal reflux disease. Here, we aimed to investigate the "in vitro" topical protective capacity of AG on human esophageal mucosa. METHODS: Biopsies of the distal esophageal mucosa were collected from 35 patients with heartburn (24 non-erosive and 11 with erosive oesophagitis (EE)) and mounted in Üssing chambers. AG was applied topically, followed by exposure with acid solution (pH 2.0 or pH 1.0), where transepithelial electrical resistance (TER) and The transepithelial permeability for fluorescein was assessed. The incubation of the AG labeled with FITC in the esophageal mucosa was localized by fluorescence microscopy. KEY FINDINGS: Pretreatment with AG prevented the drop in TER induced by acid solution, as well as significantly decreases the fluorescein permeability in non-erosive patients. The protective effect of AG was sustained for up to 120 min both in biopsies of non-erosive and erosive esophagitis. Confocal microscope images showed mucosal luminal adherence of FITC-labeled AG. CONCLUSION: AG had a prolonged topical protective effect against acid solution in mucosal biopsies of patients with non-erosive and erosive esophagitis.

COVID-19 IN INFLAMMATORY BOWEL DISEASE: SHOULD WE BE MORE CAREFUL WITH THE USE OF SALICYLATES?

BACKGROUNDS: Fortunately, much has been studied about COVID-19 in patients with inflammatory bowel diseases (IBD). Evidence suggests that these patients do not appear to be at increased risk of severe COVID-19. However, there are still some uncertainties regarding the clinical manifestations of COVID-19 in patients with immune-mediated diseases. OBJECTIVE: This study aimed to describe the main symptoms of COVID-19 and their frequency in IBD patients and evaluate the impact of the IBD therapeutic drugs on clinical presentation of COVID-19 and to determine factors associated with COVID-19 in this population. METHODS: Adult patients with IBD from three tertiary-care public, teaching hospitals in Ceará, Northeastern Brazil, were evaluated during one scheduled appointment from March to December 2020. Patients with possible or confirmed COVID-19 were compared with patients without COVID-19. Furthermore, incidences of each symptom were evaluated based on the use of IBD therapeutic drugs. RESULTS: A total of 515 patients with IBD were included in the study: 234 with CD, and 281 with UC. Of these, 174 patients (34%) had possible/confirmed COVID-19 of whom 156 (90%) were symptomatic. Main symptoms were fever (65%) and headache (65%); gastrointestinal symptoms occurred in one third of patients and were higher than COVID-19 in general population. The factors associated with having COVID-19 were female gender (OR 1.71, 95%CI: 1.17-2.50); contact at home (OR 5.07, 95%CI: 3.31-7.78) and outside the home (OR 3.14, 95%CI: 2.10-4.71) with a case of COVID-19; work outside of the home (OR 1.87, 95%CI: 1.26-2.78); family history of COVID-19 (OR 2.29, 95%CI 1.58-3.33) use of salicylate (OR 1.71, 95%CI: 1.17-4.28); and asthma (OR 7.10, 95%CI: 1.46-34.57). CONCLUSION: IBD patients at high risk of COVID-19 infection may need to avoid salicylate therapy but further studies are necessary to confirm this association.

Inspiratory muscle training improves antireflux barrier in GERD patients.

The crural diaphragm (CD) is an essential component of the esophagogastric junction (EGJ), and inspiratory exercises may modify its function. This study's goal is to verify if inspiratory muscle training (IMT) improves EGJ motility and gastroesophageal reflux (GER). Twelve GER disease [GERD; 7 males, 20-47 yr, 9 esophagitis, and 3 nonerosive reflex disease (NERD)] and 7 healthy volunteers (3 males, 20-41 yr) performed esophageal pH monitoring, manometry, and heart rate variability (HRV) studies. A 6-cm sleeve catheter measured average EGJ pressure during resting, peak inspiratory EGJ pressures during sinus arrhythmia maneuver (SAM) and inhalations under 17-, 35-, and 70-cmH2O loads (TH maneuvers), and along 1 h after a meal. GERD patients entered a 5-days-a-week IMT program. One author scored heartburn and regurgitation before and after IMT. IMT increased average EGJ pressure (19.7 ± 2.4 vs. 29.5 ± 2.1 mmHg; P < 0.001) and inspiratory EGJ pressure during SAM (89.6 ± 7.6 vs. 125.6 ± 13.3 mmHg; P = 0.001) and during TH maneuvers. The EGJ-pressure gain across 35- and 70-cmH2O loads was lower for GERD volunteers. The number and cumulative duration of the transient lower esophageal sphincter relaxations decreased after IMT. Proximal progression of GER decreased after IMT but not the distal acid exposure. Low-frequency power increased after IMT and the higher its increment the lower the increment of supine acid exposure. IMT decreased heartburn and regurgitation scores. In conclusion, IMT improved EGJ pressure, reduced GER proximal progression, and reduced GERD symptoms. Some GERD patients have a CD failure, and IMT may prove beneficial as a GERD add-on treatment.

Dyspepsia and gastric emptying in end-stage renal disease patients on hemodialysis.

BACKGROUND: Dyspepsia is common among end-stage renal disease (ESRD) patients and its association with delayed gastric emptying is not well established. We assessed the association of dyspepsia with gastric emptying time in ESRD patients undergoing hemodialysis (HD). METHODS: Dyspepsia was assessed through the Porto Alegre Dyspeptic Symptoms Questionnaire (PADYQ). PADYQ's scores ≥ 6 classified participants as dyspeptic. The octanoic acid breath test using ¹³carbon was employed to assess the gastric emptying time. Based on the test, time in minutes to metabolize the first half of the ¹³carbon in the test meal (t1/2) was calculated. Association of dyspepsia with gastric emptying time was tested by the correlation between PADYQ scores and t1/2, and also by comparing t1/2 between dyspeptics and non-dyspeptics. RESULTS: There were 34 (68.0%) dyspeptic patients. Dyspepsia score was positively correlated with t1/2 (r = 0.366; p = 0.009). Dyspeptics had longer t1/2 compared to non-dyspeptics, respectively, 238.0 ± 92.9 versus 185.5 ± 45.5 minutes (p = 0.042). CONCLUSIONS: Delayed gastric emptying was associated with dyspepsia. Prokinetic medications could have a role in preventing or relieving dyspeptic symptoms among HD patients. Future research in larger samples is necessary to confirm this association.

Antiinflammatory and antinociceptive effects in mice of a sulfated polysaccharide fraction extracted from the marine red algae Gracilaria caudata.

Many algal species contain relatively high concentrations of polysaccharide substances, a number of which have been shown to have anti-inflammatory and/or immunomodulatory activity. In this study, we evaluated the anti-inflammatory and antinociceptive effects in mice of a sulfated polysaccharide fraction (PLS) extracted from the algae Gracilaria caudata. The antiinflammatory activity of PLS was evaluated using several inflammatory agents (carrageenan, dextran, bradykinin, and histamine) to induce paw edema and peritonitis in Swiss mice. Samples of the paw tissue and peritoneal fluid were removed to determine myeloperoxidase (MPO) activity or TNF-α and IL-1ß levels, respectively. Mechanical hypernociception was induced by subcutaneous injection of carrageenan into the plantar surface of the paw. Pretreatment of mice by intraperitoneal administration of PLS (2.5, 5, and 10 mg/kg) significantly and dose-dependently reduced carrageenan-induced paw edema (p < 0.05) compared to vehicle-treated mice. Similarly, PLS 10 mg/kg effectively inhibited edema induced by dextran and histamine; however, edema induced by bradykinin was unaffected by PLS. PLS 10 mg/kg inhibited total and differential peritoneal leukocyte counts following carrageenan-induced peritonitis. Furthermore, PLS reduced carrageenan-increased MPO activity in paws and reduced cytokine levels in the peritoneal cavity. Finally PLS pretreatment also reduced hypernociception 3-4 h after carrageenan. We conclude that PLS reduces the inflammatory response and hypernociception in mice by reducing neutrophil migration and cytokines concentration.

Crucial role of carbon monoxide as a regulator of diarrhea caused by cholera toxin: Evidence of direct interaction with toxin.

The present study evaluated the role of heme oxygenase 1 (HO-1)/carbon monoxide (CO) pathway in the cholera toxin-induced diarrhea and its possible action mechanism. The pharmacological modulation with CORM-2 (a CO donor) or Hemin (a HO-1 inducer) decreased the intestinal fluid secretion and Cl- efflux, altered by cholera toxin. In contrast, ZnPP (a HO-1 inhibitor) reversed the antisecretory effect of Hemin and potentiated cholera toxin-induced intestinal secretion. Moreover, CORM-2 also prevented the alteration of intestinal epithelial architecture and local vascular permeability promoted by cholera toxin. The intestinal absorption was not altered by any of the pharmacological modulators. Cholera toxin inoculation also increased HO-1 immunoreactivity and bilirubin levels, a possible protective physiological response. Finally, using fluorometric technique, ELISA assay and molecular docking simulations, we show evidence that CO directly interacts with cholera toxin, forming a complex that affects its binding to GM1 receptor, which help explain the antisecretory effect. Thus, CO is an essential molecule for protection against choleric diarrhea and suggests its use as a possible therapeutic tool.

Laryngeal and Esophageal Mucosal Protection Using the Angico Gum Biopolymer in a Mouse Model of Reflux.

OBJECTIVE: This study aimed to evaluate the in vivo protective effect of the angico gum biopolymer in reducing the inflammatory response and preserving the integrity of the laryngeal and esophageal mucosa. STUDY DESIGN: Animal study. METHODS: A murine surgical model of gastroesophageal reflux disease was accomplished and subsequently treated with angico gum or omeprazole. On days 3 and 7 post surgery, samples of the larynx and esophagus, respectively, were collected to measure the level of inflammation (wet weight and myeloperoxidase activity) and mucosal integrity (transepithelial electrical resistance and mucosal permeability to fluorescein). RESULTS: Angico gum and omeprazole decreased laryngeal inflammation (wet weight and myeloperoxidase activity) and dramatically improved the integrity of the laryngeal mucosa. It also reduced inflammation (decreased wet weight and myeloperoxidase activity) of the esophagus and preserved the barrier function (inferred by assessing the integrity of the mucosa). CONCLUSION: This study demonstrates the protective effect of angico gum in an experimental gastroesophageal reflux disease model. Angico gum attenuates inflammation and impairment of the mucosal barrier function not only in the larynx but also in the esophagus. LEVEL OF EVIDENCE: NA Laryngoscope, 133:162-168, 2023.

Dyspeptic symptoms and delayed gastric emptying of solids in patients with inactive Crohn's disease.

BACKGROUND: Patients with Crohn's disease (CD) have been shown to present dyspeptic symptoms more frequently than the general population. Some of these symptoms could be related to motility disorders to some degree. Then, we propose to investigate whether gastric emptying of solids in patients with inactive CD is delayed and to determine the relationships between gastric emptying and dyspeptic symptoms in inactive CD. METHODS: Twenty-six patients with inactive Crohn's disease, as defined by a Crohn's Disease Activity Index (CDAI) < 150, underwent a gastric emptying test by breath test using 13C octanoic acid coupled to a solid meal and answered a validated questionnaire (The Porto Alegre Dyspeptic Symptoms Questionnaire) to assess dyspeptic symptoms. Patients with scores ≥ 6 were considered to have dyspepsia. The control group was composed by 19 age- and sex-matched healthy volunteers. RESULTS: Patients with CD had a significantly longer t 1/2 and t lag (p<0.05) than the controls. CD patients with dyspepsia had significantly (p<0.05) prolonged gastric emptying when compared to patients without dyspeptic symptoms. When the individual symptom patterns were analyzed, only vomiting was significantly associated with delayed gastric emptying (p<0.05). There was no difference between the subgroups of patients with respect to gender, CDAI scores, disease location, clinical behavior (obstructive/obstructive) or previous gastrointestinal surgery. CONCLUSION: Delayed gastric emptying in inactive Crohn's disease patients seems to be associated with dyspeptic symptoms, particularly vomiting, even without any evidence of gastrointestinal obstruction.

BILIARY FISTULAS ASSOCIATED WITH LIVER TRANSPLANTATION VERSUS OTHER ETIOLOGIES: WHAT IS THE SUCCESS RATE OF THE ENDOSCOPIC TREATMENT?

BACKGROUND: Biliary fistulas typically occur as surgical complications after laparoscopic cholecystectomy, liver transplantation, or partial liver resection. AIMS: This study aimed to evaluate the efficacy of the endoscopic treatment of biliary fistulae secondary to liver transplantation compared to that of other etiologies. METHODS: A retrospective study of 25 patients undergoing endoscopic retrograde cholangiopancreatography for biliary fistula from 2015 to 2021 was conducted at the Endoscospy Unit of Walter Cantídio University Hospital. Clinical characteristics and endoscopic success rates of the post-liver transplantation group were analyzed in comparison with those of other etiologies. RESULTS: The main causes of biliary fistula were liver transplantation (44%) and cholecystectomy complications (44%). The post-liver transplantation group had a significantly higher proportion of male sex (liver transplantation=81.8%, others=28.6%) and older age (liver transplantation=54.1 years, others=42.0 years) and a higher incidence of biliary stenosis (liver transplantation=90.9%, others=14.3%) than those of the group with other etiologies (p<0.05). The two groups received similar treatment types, among which sphincterotomy associated with biliary stent placement was most commonly used. Endoscopic therapeutic success rates showed no significant difference between the post-liver transplantation group (63.6%) and the group with other etiologies (71.4%). CONCLUSIONS: The endoscopic treatment of biliary fistulae secondary to liver transplantation presented a recovery rate similar to that of other etiologies despite the patients older age and the presence of biliary stenosis.

Modulatory Role of Carbon Monoxide on the Inflammatory Response and Oxidative Stress Linked to Gastrointestinal Disorders.

Significance: Carbon monoxide (CO) is an endogenous gaseous mediator that plays an important role in maintaining gastrointestinal (GI) tract homeostasis, acting in mucosal defense, and providing negative modulation of pathophysiological markers of clinical conditions. Recent Advances: Preclinical studies using animal models and/or cell culture show that CO can modulate the inflammatory response and oxidative stress in GI mucosal injuries and pathological conditions, reducing proinflammatory cytokines and reactive oxygen species, while increasing antioxidant defense mechanisms. Critical Issues: CO has potent anti-inflammatory and antioxidant effects. The defense mechanisms of the GI tract are subject to aggression by different chemical agents (e.g., drugs and ethanol) as well as complex and multifactorial diseases, with inflammation and oxidative stress as strong triggers for the deleterious effects. Thus, it is possible that CO acts on a variety of molecules involved in the inflammatory and oxidative signaling cascades, as well as reinforcing several defense mechanisms that maintain GI homeostasis. Future Directions: CO-based therapies are promising tools for the treatment of GI disorders, such as gastric and intestinal injuries, inflammatory bowel disease, and pancreatitis. Therefore, it is necessary to develop safe and selective CO-releasing agents and/or donor drugs to facilitate effective treatments and methods for analysis of CO levels that are simple and inexpensive. Antioxid. Redox Signal. 37, 98-114.

Sulfated-polysaccharide fraction from red algae Gracilaria caudata protects mice gut against ethanol-induced damage.

The aim of the present study was to investigate the gastroprotective activity of a sulfated-polysaccharide (PLS) fraction extracted from the marine red algae Gracilaria caudata and the mechanism underlying the gastroprotective activity. Male Swiss mice were treated with PLS (3, 10, 30 and 90 mg·kg(-1), p.o.), and after 30 min, they were administered 50% ethanol (0.5 mL/25 g(-1), p.o.). One hour later, gastric damage was measured using a planimeter. Samples of the stomach tissue were also obtained for histopathological assessment and for assays of glutathione (GSH) and malondialdehyde (MDA). Other groups were pretreated with l-NAME (10 mg·kg(-1), i.p.), dl-propargylglycine (PAG, 50 mg·kg(-1), p.o.) or glibenclamide (5 mg·kg(-1), i.p.). After 1 h, PLS (30 mg·kg(-1), p.o.) was administered. After 30 min, ethanol 50% was administered (0.5 mL/25 g(-1), p.o.), followed by sacrifice after 60 min. PLS prevented-ethanol-induced macroscopic and microscopic gastric injury in a dose-dependent manner. However, treatment with l-NAME or glibenclamide reversed this gastroprotective effect. Administration of propargylglycine did not influence the effect of PLS. Our results suggest that PLS has a protective effect against ethanol-induced gastric damage in mice via activation of the NO/K(ATP) pathway.