Gastrointestinal Injury Research Articles

The Spectrum of Digestive Tract Histopathologic Findings in the Setting of Severe Acute Respiratory Syndrome Coronavirus-2 Infection: What Pathologists Need to Know.

Although the novel severe acute respiratory syndrome coronavirus-2 is known primarily to affect the respiratory system, current evidence supports its capability to infect and induce gastrointestinal tract injury. Data describing the histopathologic alterations of the digestive system in patients infected with severe acute respiratory syndrome coronavirus-2 are becoming more detailed, as the number of studies is increasing and the quality of our insight into the infection and the histopathologic findings is improving. This review highlights the range of pathologic findings that could be observed in gastrointestinal specimens from patients infected with coronavirus disease 2019 and the potential underlying pathogenetic mechanisms of this disease.

A mechanism of Sijunzi decoction on improving intestinal injury with spleen deficiency syndrome and the rationality of its compatibility.

Sijunzi Decoction (SJZD) is a renowned formula for the treatment of spleen deficiency syndrome (SDS) in traditional Chinese medicine (TCM). Its non-polysaccharides (NPS) component, dominated by various compounds of SJZD, has shown the remarkable efficacy in SDS, especially in gastrointestinal injury. However, the principle of compatibility of SJZD and the micro-mechanism of effect on SDS are still unclear. To elucidate the scientific implications of SJZD compatibility and its micro-mechanism in the treatment of SDS-induced intestinal injury. First, the chemical composition of NPS in SJZD and incomplete SJZD (iSJZD, including SJZD-R, SJZD-A, SJZD-P, SJZD-G) were comprehensively analyzed by UPLC-QTOF-MS, and comparing their chemical composition by multivariate statistical analysis to reveal the effect of a single herb on SJZD compatibility. Second, network pharmacology and molecular docking were used to uncover the micro-mechanisms of potential active compounds in SJZD for the treatment of SDS, and develop an active component combination (ACC) by accurate quantification. Subsequently, the action of the potential active compounds and ACC was verified through in vivo and in vitro. A total of 112, 77, 93, 87, and 67 compounds were detected in NPS of SJZD, SJZD-R, SJZD-A, SJZD-P, and SJZD-G, respectively. Changes in the chemical components of SJZD_NPS and iSJZD_NPS revealed that RG and RAM, as well as RAM and Poria significantly affected the dissolution of each other's chemical components, and the co-decoction of four herbs promoted the dissolution of the active compounds and inhibited toxic compounds. Furthermore, network pharmacology showed that 274 compounds of 15 categories in SJZD_NPS acted on the 186 key targets to treat SDS by inhibiting inflammation, enhancing immunity, and regulating gastrointestinal function and metabolism. Finally, through in vitro experiments, six compounds among 18 potential compounds were verified to markedly repair intestinal epithelium injury by modulating the FAK/PI3K/Akt or LCK/Ras/PI3K/Akt signaling pathway. It is worth mentioning that ACC, composed of 11 compounds accurately quantified, demonstrated significant in vivo treatment effects on intestinal damage with SDS similar to NPS or SJZD. This study elucidates the scientific evidence of the "Jun-Chen-Zuo-Shi" and "detoxification and synergistic" in the decocting process of SJZD. An ACC, the active component of SJZD, ameliorate SDS-induced intestinal injury by the FAK/PI3K/Akt signaling pathway, which provides a strategy for screening alternatives to effective combinations of TCMs.

Advances in Hydrogel Adhesives for Gastrointestinal Wound Closure and Repair.

Millions of individuals undergo gastrointestinal (GI) tract surgeries each year with common postoperative complications including bleeding, perforation, anastomotic leakage, and infection. Today, techniques such as suturing and stapling seal internal wounds, and electrocoagulation stops bleeding. These methods induce secondary damage to the tissue and can be technically difficult to perform depending on the wound site location. To overcome these challenges and to further advance wound closure, hydrogel adhesives are being investigated to specifically target GI tract wounds because of their atraumatic nature, fluid-tight sealing capability, favorable wound healing properties, and facile application. However, challenges remain that limit their use, such as weak underwater adhesive strength, slow gelation, and/or acidic degradation. In this review, we summarize recent advances in hydrogel adhesives to treat various GI tract wounds, with a focus on novel material designs and compositions to combat the environment-specific challenges of GI injury. We conclude with a discussion of potential opportunities from both research and clinical perspectives.

A Review on the Appropriate Dosage of Aspirin as a Prophylactic Agent Against Deep Vein Thrombosis Following Total Knee Arthroplasties

Guidelines regarding Deep Vein Thrombosis prophylaxis following total knee arthroplasties have had conflicting information regarding the use of aspirin as a prophylactic agent in recent years. The National Institute for Clinical Excellence refrains from listing the drug in its guidelines while the American College of Chest Physicians advocates for the drug. Despite the conflicting guidelines, physicians have favored the drug in recent years, with more than 80% utilizing it as a prophylactic agent in total knee arthroplasties. Although a consensus may have been reached by physicians regarding the use of the drug, a consensus has not been reached regarding the preferred dosage. With this in mind, a search of the PubMed database was conducted which yielded six studies that discussed the efficacy of various dose ranges of aspirin. All studies corroborated that not only was aspirin an effective prophylactic agent, but that there was no significant difference between dosages regarding efficacies. Due to factors such as aspirin resistance and the potential of aspirin to cause gastrointestinal injuries, this literature review concludes that the dosage of aspirin given for the prophylaxis of DVT in TKAs should be considered on a patient to patient basis.

Cardiac arrest caused by the application of pituitrin during laparoscopic myomectomy

BackgroundPituitrin injection solution is an indispensable hemostatic utilized in clinical practice and is widely used in myomectomy. However, there have been reports of adverse reactions leading to gastrointestinal injury, hyponatremia and hypokalemia, anaphylaxis, cardiac arrest, etc. Thus, the safety of pituitrin should be taken seriously.Case presentationIn the present study, three cases of cardiac arrest caused by pituitrin injection during laparoscopic myomectomy, who were successfully resuscitated in our hospital, are reported.ConclusionThe clinical data and surgical procedures in the patient should be analyzed to find the causes of cardiac arrest. Medication and resuscitation should be summarized to ensure the safety of the patient.

Evaluation of gastrointestinal tract injury within 1year of surgery for pelvic organ prolapse.

To identify the incidence and risk factors of gastrointestinal injury (GITI) related to pelvic organ prolapse (POP) surgery. Women who underwent POP surgery between 2000 and 2020 were identified in the Premier Healthcare Database. The primary outcome was GITI, defined as small or large bowel injury or repair, and fistula or fistula repair. Differences between patients with and without GITI were evaluated, and a multivariable regression was performed to determine independent predictors of GITI. We identified 563,661 index POP surgeries in female patients aged 18years and older. Of these, 4582 (0.8%) had a bowel injury code within 1year of index POP surgery. Patients who experienced GITI were more likely to be younger (49.9 ± 12.8 vs 50.9 ± 13.7), and receive surgery with a surgeon who performed less than 12 surgeries per year (48% vs 42%). Most GITI was diagnosed in the same month (73.4%) and same hospital encounter (54%) as index POP surgery. After adjusting for confounders, lysis of adhesions (aOR = 2.03, 95% CI: 1.48-2.72) and perioperative hematoma/hemorrhage (aOR = 2.87, 95%C I: 1.70-4.59) were strongly associated with GITI, while having surgery with a surgeon performing > 50 POP surgeries per year (aOR = 0.66, 95%C I: 0.59-0.75 and concomitant obliterative procedures (aOR = 0.48, 95% CI: 0.34-0.65) were associated with a lower probability of GITI. The rate of GITI after POP surgery is less than 1%, and injuries are commonly diagnosed and treated in the same month as index surgery. High-volume surgeons and obliterative procedures may be protective against GITI.

The progression of radiation injury in a Wistar rat model of partial body irradiation with ∼5% bone marrow shielding

Purpose To describe the dose response relationship and natural history of radiation injury in the Wistar rat and its suitability for use in medical countermeasures (MCM) testing. Materials & Methods In two separate studies, male and female rats were exposed to partial body irradiation (PBI) with 5% bone marrow sparing. Animals were X-ray irradiated from 7 to 12 Gy at 7–10 weeks of age. Acute radiation syndrome (ARS) survival at 30 days and delayed effects of acute radiation exposure (DEARE) survival at 182 days were assessed. Radiation effects were determined by clinical observations, body weights, hematology, clinical chemistry, magnetic resonance imaging of lung, whole-body plethysmography, and histopathology. Results Rats developed canonical ARS responses of hematopoietic atrophy and gastrointestinal injury resulting in mortality at doses ≥8Gy in males and ≥8.5 Gy in females. DEARE mortality occurred at doses ≥8Gy for both sexes. Findings indicate lung, kidney, and/or liver injury, and persistent hematological dysregulation, revealing multi-organ injury as a DEARE. Conclusion The Wistar rat PBI model is suitable for testing MCMs against hematopoietic and gastrointestinal ARS. DEARE multi-organ injury occurred in both sexes irradiated with 8–9Gy, also suggesting suitability for polypharmacy studies addressing the combination of ARS and DEARE injury.

Association between Gastrointestinal Dysfunction Score (GIDS) and disease severity and prognosis in critically ill patients: A prospective, observational study

Recently, the Gastrointestinal Dysfunction Score (GIDS) was developed for use with critically ill patients. This study evaluated the association of GIDS with disease severity and clinical outcomes to assess the technical feasibility of using GIDS to reflect the severity and short-term prognosis of critically ill patients. Association between Gastrointestinal Dysfunction Score (GIDS) and disease severity and prognosis in critically ill patients: A prospective, observational study. This was a prospective observational study involving adult patients in two Intensive Care Units (ICUs). During the first seven days of ICU admission, GIDS, acute gastrointestinal injury (AGI), Acute Physiology and Chronic Health Evaluation II (APACHE II), and Sequential Organ Failure Assessment (SOFA) scores were assessed daily. A total of 276 patients from two centers were enrolled in this study. Patients were divided into GIDS 0-1 (121, 43.8%) and GIDS 2-4 (155, 56.2%). The ICU length of stay and 28-day mortality in the GIDS 2-4 group were significantly higher than the GIDS 0-1 group (P=0.032, P=0.001, respectively). The APACHE II and SOFA scores in the GIDS 2-4 group were also significantly higher (P<0.001). The ROC curves of GIDS, AGI, APACHE II, and SOFA scores on the first day of ICU admission for the prediction of 28-day mortality showed that the AUC of GIDS was 0.702 (95%CI 0.628, 0.775; P<0.001). The AUC for GIDS+SOFA was 0.719 (95%CI 0.648, 0.790; P<0.001), compared with SOFA alone (AUC=0.703), showing improved predictive power for 28-day mortality. GIDS represents a step toward a reliable clinical tool for GI dysfunction to assess disease severity and short-term prognosis in critically ill patients. In addition, combining GIDS with SOFA score may better predict mortality risk compared to SOFA score alone.

The Pathogenesis of Gastrointestinal, Hepatic, and Pancreatic Injury in Acute and Long Coronavirus Disease 2019 Infection.

The gastrointestinal (GI) tract is targeted by severe acute respiratory syndrome coronavirus-2. The present review examines GI involvement in patients with long coronavirus disease and discusses the underlying pathophysiological mechanisms that include viral persistence, mucosal and systemic immune dysregulation, microbial dysbiosis, insulin resistance, and metabolic abnormalities. Due to the complex and potentially multifactorial nature of this syndrome, rigorous clinical definitions and pathophysiology-based therapeutic approaches are warranted.

Value of multi-detector computed tomography in the diagnosis of blunt bowel and mesenteric injuries

Purpose: The purpose of this study was to evaluate the role of MDCT in detecting and predicting blunt bowel and mesenteric injuries. Materials and methods: This is a retrospective observational study of 66 patients (54 males, 12 females, average age of 45.5 years) who underwent laparotomy at Nghe An Friendship General Hospital between April 2020 and August 2021 with a diagnosis of bowel and/or mesenteric injuries in blunt abdominal trauma. All of these patients had a contrast-enhanced MDCT prior to surgery. All CT findings were documented and calculated for their diagnostic performance compared to surgical outcomes. Results: The most common finding was mesenteric infiltration (75.8%), followed by bowel wall thickening (63.6%). Bowel wall discontinuity had the highest specificity and positive predictive value of 100%. The most sensitive signs were free air 81.6%, mesenteric infiltration 79.7%. The specificity of bowel hypoenhancement and mesenteric vessel abnormalities were highest at 92.3% and 98.1%, respectively. Bowel wall thickening, bowel wall hypoenhancement, mesenteric vessel abnormalities, and free air had strongest association with blunt bowel and/or mesenteric injury requiring surgery (OR = 5.7, 51, 68 and 14.4, respectively). Conclusion: The multi-detector computed tomography provides high-specificity important findings indicating bowel and mesenteric injuries necessitating surgery. Key words: bowel and mesenteric injury, gastrointestinal tract injury, blunt abdominal trauma, computed tomography.

Lésions iatrogènes du tube digestif vues par le pathologiste

The number of drugs available to clinicians, especially targeted therapies, grows continuously. Some drugs are known to cause frequent digestive adverse effects, which may affect the gastro-intestinal tract in a diffuse or localized manner. Some treatments may leave relatively pathognomonic deposits, but histological lesions of iatrogenic origin are mostly non-specific. The diagnostic and etiological approach is often complex because of these non-specific aspects and also because (1) a single type of drug may cause different histological lesions, (2) different drugs may cause identical histological lesions, (3) the patient may receive different drugs, and (4) drug-induced lesions may mimic other pathological entities such as inflammatory bowel disease, celiac disease, or graft versus host disease. The diagnosis of iatrogenic gastrointestinal tract injury therefore requires close anatomic-clinical correlation. The iatrogenic origin can only be formally established if the symptomatology improves when the incriminating drug is stopped. This review aims to present the different histological patterns of gastrointestinal tract iatrogenic lesions, the potentially incriminate drugs, as well as the histological signs to look for in order to help the pathologist to distinguish an iatrogenic injury from another pathology of the gastrointestinal tract.

Evaluation of gastrointestinal tract injury during surgery for pelvic organ prolapse within one year after surgery

Evaluation of gastrointestinal tract injury during surgery for pelvic organ prolapse within one year after surgery

Gut microbe-derived milnacipran enhances tolerance to gut ischemia/reperfusion injury

There are significant differences in the susceptibility of populations to intestinal ischemia/reperfusion (I/R), but the underlying mechanisms remain elusive. Here, we show that mice exhibit significant differences in susceptibility to I/R-induced enterogenic sepsis. Notably, the milnacipran (MC) content in the enterogenic-sepsis-tolerant mice is significantly higher. We also reveal that the pre-operative fecal MC content in cardiopulmonary bypass patients, including those with intestinal I/R injury, is associated with susceptibility to post-operative gastrointestinal injury. We reveal that MC attenuates mouse I/R injury in wild-type mice but not in intestinal epithelial aryl hydrocarbon receptor (AHR) gene conditional knockout mice (AHRflox/flox) or IL-22 gene deletion mice (IL-22-/-). Collectively, our results suggest that gut microbiota affects susceptibility to I/R-induced enterogenic sepsis and that gut microbiota-derived MC plays a pivotal role in tolerance to intestinal I/R in an AHR/ILC3/IL-22 signaling-dependent manner, revealing the pathological mechanism, potential prevention and treatment drugs, and treatment strategies for intestinal I/R.

Transabdominal gastro-intestinal ultrasonography (TGIU) for predicting feeding intolerance in critically ill patients: A prospective observational study

This study aimed at verifying the feasibility of transabdominal gastro-intestinal ultrasonography (TGIU) for predicting feeding intolerance (FI). This single-center prospective observational study comprising critically ill patients who were admitted to an intensive care unit (ICU) and received enteral nutrition through a nasogastric tube. TGIU parameters including gastric antral cross-sectional area (CSA) and acute gastrointestinal injury ultrasonography (AGIUS) score, were conducted on days 1, 3, 5, and 7 within the first week of starting enteral nutrition (EN). A total of 91 patients were eligible for inclusion and 57 showed FI. The incidence of FI was 28.6%, 41.8%, 29.7%, and 27.5% on days 1, 3, 5, and 7, respectively, and the incidence of FI was 62.6% within the first week of starting EN. Univariate logistic regression analysis showed that SOFA score, CSA, and AGIUS score, were significantly (P<0.05) associated with the FI on the same day. In the multivariate analysis including two variables, CSA, and AGIUS score were found to remain independent predictors for FI and 28-day mortality. An area under the curve (AUC) for TGIU predicted FI in the first week of starting EN (the cut-off of CSA ≥6.0cm2 yielded a sensitivity of 86.0% and specificity of 79.4%, and for AGIUS score ≥3.5 yielded a sensitivity of 87.7% and specificity of 82.4%). The predictive value of TGIU for 28-day mortality was higher than the SOFA score [0.827 (0.733-0.921) vs. 0.646 (0.519-0.774), P=0.001]. TGIU represented an effective means for predicting FI and 28-day mortality in critically ill patients. These results supported the hypothesis that persistent FI in critically ill patients is an essential determinant for poor prognosis.

Oxidative Stress May Contribute to the Intestinal Dysfunction of Weanling Rats Fed a Low Protein Diet

Intestinal function is impaired in malnutrition. Because oxidative stress is a component of gastrointestinal injury, and malnutrition may reduce antioxidant defenses, we investigated the involvement of oxidative stress in the intestinal dysfunction due to malnutrition. Weanling rats were fed either a normal protein (22% casein) or a low protein (6% casein) diet for 4 wk. In intestinal homogenates, we assessed free radical damage and enzymatic antioxidant defenses. In jejunal fragments mounted in Ussing chambers, we measured ionic transport by short-circuit current (Isc) and protein permeability by transepithelial fluxes of beta-lactoglobulin. Catalase activity and the thiobarbituric acid-reacting substances concentration were greater in intestinal mucosa of the low protein group, whereas the glutathione concentration and the activities of superoxide dismutase and Se-dependent glutathione peroxidase were the same as in the normal protein group intestinal mucosa. Both basal Isc and the delta Isc induced by glucose and forskolin, as well as beta-lactoglobulin fluxes, were higher in the low protein group. Exogenous H2O2 stress increased Isc significantly more in the low protein than the normal protein group but did not alter protein permeability. These results show that malnutrition induces both intestinal free radical damage and altered epithelial transport, suggesting that oxidative stress may contribute to the intestinal dysfunction associated with malnutrition.

Quercetin 3-O rutinoside prevents gastrointestinal injury through regulation of apoptosis in 7.5 Gy total body irradiated mice

BackgroundDespite the heightened threat to unforeseen nuclear/radiological exposures worldwide, no countermeasures are currently approved to prevent gastrointestinal (GI) toxicity induced by radiation in humans. PurposeIn this study, we aim to establish the gastroprotective role of flavonoid, Quercetin-3-O-rutinoside (Q-3-R) against 7.5 Gy total body gamma radiation dose that contributes to the hematopoietic syndrome. MethodsQ-3-R (10 mg/kg body weight) was administered intramuscularly to C57BL/6 male mice before exposure to 7.5 Gy and monitored for morbidity and mortality. The GI protection against radiation was ascertained by histopathological and xylose absorption studies. Intestinal apoptosis, crypt proliferation and apoptotic signaling were also investigated in different treatment groups. ResultsWe found that Q-3-R prevented the radiation-induced loss of mitochondrial membrane potential, maintained ATP levels, regulated the apoptotic pathway, and activated crypt cell proliferation in the intestine. Radiation-induced villi and crypt damage as well as mal-absorption were significantly minimized in the Q-3-R treated group. We observed 100% survival post Q-3-R administration against 33.3% lethality in 7.5 Gy (LD33.3/30) exposed C57BL/6 mice. The Q-3-R pre-treated mice that survived the 7.5 Gy dose revealed no pathological changes related to the development of fibrosis in the intestine and thickened mucosal wall till 4 months post irradiation. Complete hematopoietic recovery was observed in these surviving mice when compared to age matched control. ConclusionThe findings revealed that Q-3-R regulated the apoptotic process to achieve GI protection against LD33.3/30 dose (7.5 Gy) that primarily caused death due to hematopoietic failure. The recovery observed in mice survivors suggested that this molecule may also have the potential to minimize side effects on normal tissues during radiotherapy.

EuHD1 protects against inflammatory injury driven by NLRP3 inflammasome.

Non-steroidal anti-inflammatory drugs (NSAIDs) possessing anti-inflammatory, analgesic and antipyretic activities, are widely used in the treatment of osteoarthritis, rheumatism and rheumatoid arthritis. However, its long-term or large use will cause serious gastrointestinal injury or cardiovascular adverse reactions, which limits its clinical application. We have synthesized a new class of NSAIDs, EuHD1, which can release hydrogen sulfide and have better gastrointestinal safety. However, the anti-inflammatory molecular mechanism of the drug is still unclear. In this paper, we explored the mechanism of EuHD1 on NLRP3 inflammasome and its effects on acute lung injury and acute liver injury in mice. In vitro results demonstrated that EuHD1 inhibited macrophage pyroptosis and LDH release induced by LPS combined with ATP. In addition, EuHD1 blocked NLRP3 inflammasome activation and suppressed following Caspase-1 activation and secretion of mature IL-1β. EuHD1 restrained intracellular ROS production and the formation of ASC oligomers, which inhibited the assembly and activation of NLRP3 inflammasome. In vivo results further showed that EuHD1 alleviated LPS-induced acute lung injury in mice, and inhibited the production of mature IL-1β and Caspase-1 (p20). Besides, EuHD1 improved D-GalN/LPS-induced acute liver injury, and inhibited SOD/MDA levels and oxidative stress injury, and blocked the activation of NLRP3 inflammasome. In summary, we found that EuHD1 inhibits the assembly and activation of NLRP3 inflammasome through restraining the production of ROS and the formation of ASC oligomers, and has therapeutic effects on acute lung injury and liver injury in mice, indicating that EuHD1 has the potential to treat NLRP3 inflammasome-related diseases.

Epidemiology and clinical characteristics of pediatric sepsis in PICUs of China: A national cross-sectional study.

Epidemiology and clinical characteristics of pediatric sepsis in PICUs of China: A national cross-sectional study.

Amino acid profiles, amino acid sensors and transporters expression and intestinal microbiota are differentially altered in goats infected with Haemonchus contortus.

Infection with the nematode Haemonchus contortus causes host malnutrition and gastrointestinal injuries. The objective of this study was to investigate the effects of H. contortus infection on gastrointestinal contents of free amino acids (AA), the expression of AA transporters and microbiota with a focus on amino acid metabolism. Twenty-four Xiangdong black goats (13 ± 1.5kg, 6months old) were randomly assigned into the control group (n = 8) and the infected group (n = 16). The results showed that H. contortus infection increased (P < 0.05) the free AA contents in jejunum and ileum digesta. The concentrations of blood threonine, phenylalanine and tyrosine were lower (P < 0.05) in theinfected group as compared to the controlgroup. In the jejunum and ileum epithelium, H. contortus infection significantly (P < 0.05) down-regulated the expression of AA transporter b0,+AT/rBAT and B0AT1, but up-regulated (P < 0.05) the expression of transporter CAT2 and xCT. Furthermore, microbiota in both jejunum (Bifidobacteriaceae, Lachnospiraceae, Bacteroidaceae, Enterobacteriaceae, and Micrococcaceae) and ileum (Acidaminococcaceae, Desulfovibrionaceae, Bacteroidaceae, and Peptostreptococcaceae) were also altered at the family level by H. contortus infection. The commensal bacteriaof jejunum showed a close correlation with amino acids, AA transporters, and amino acid metabolism, especially cystine. In conclusion, H. contortus infection affected theintestinal AA contents and the expression of intestinal AA transporters, suggesting altered AA metabolism and absorption, which were accompanied by changes inthe relative abundances of gut bacteria that mediate amino acid metabolism.

Dose- and Segment-Dependent Disturbance of Rat Gut by Ionizing Radiation: Impact of Tight Junction Proteins.

The damaging effect of ionizing radiation (IR) exposure results in the disturbance of the gut natural barrier, followed by the development of severe gastrointestinal injury. However, the dose and application segment are known to determine the effects of IR. In this study, we demonstrated the dose- and segment-specificity of tight junction (TJ) alteration in IR-induced gastrointestinal injury in rats. Male Wistar rats were subjected to a total-body X-ray irradiation at doses of 2 or 10 Gy. Isolated jejunum and colon segments were tested in an Ussing chamber 72 h after exposure. In the jejunum, 10-Gy IR dramatically altered transepithelial resistance, short-circuit current and permeability for sodium fluorescein. These changes were accompanied by severe disturbance of histological structure and total rearrangement of TJ content (increased content of claudin-1, -2, -3 and -4; multidirectional changes in tricellulin and occludin). In the colon of 10-Gy irradiated rats, lesions of barrier and transport functions were less pronounced, with only claudin-2 and -4 altered among TJ proteins. The 2-Gy IR did not change electrophysiological characteristics or permeability in the colon or jejunum, although slight alterations in jejunum histology were noted, emphasized with claudin-3 increase. Considering that TJ proteins are critical for maintaining epithelial barrier integrity, these findings may have implications for countermeasures in gastrointestinal acute radiation injury.