Rare case of lupus enteritis presenting as colorectum involvement:A case report and review of literature

BACKGROUND Systemic lupus erythematosus(SLE)is a multisystem autoimmune disease that can affect the gastrointestinal tract.Most cases of lupus enteritis(LE)involve the small intestine,while the involvement of the whole colon and rectum without the small intestine being affected is extremely rare.CASE SUMMARY A 35-year-old woman was diagnosed with colorectal LE after initially presenting with intermittent abdominal pain and vomiting for two months.She had a regular medication history for five years following the diagnosis of SLE but had been irregular in taking medications,which may have contributed to the onset of LE and led to her current hospital admission.According to the 2019 Classification criteria for SLE of the European League Against Rheumatism/American College of Rheumatology,this case scored 14.Additionally,abdominal computed tomography revealed significant wall edema of the colon and rectum,ischemia and hyperemia of the ascending colon intestinal wall,mesenteric vessel engorgement,increased mesangial fat attenuation,ascites,and bilateral ureter-hydronephrosis,all indicative of colon and rectum LE.Laboratory tests also showed lower levels of complement C3 and C4,with an antinuclear antibody titer of 1:100.Overall,it was clear that this case involved the colon and rectum without affecting the small intestine,representing a rare manifestation of SLE.The patient received treatment with 10 mg of methylprednisolone sodium succinate,100 mL of 0.9%sodium chloride,hydroxychloroquine(100 mg),and nutrition support.After one week of methylprednisolone and hydroxychloroquine therapy,her SLE symptoms and disease activity improved significantly.CONCLUSION Although colorectal LE without small intestine involvement is very rare,early diagnosis and excellent management with corticosteroids prevented the need for surgical intervention.Physicians should be aware of colorectal LE without small intestine involvement as a manifestation of lupus flare.

Evaluation of the metabolism of PEP06,an endostatin-RGDRGD 30-amino-acid polypeptide and a promising novel drug for targeting tumor cells

PEP06 is a novel endostatin-Arg-Gly-Asp-Arg-Gly-Asp(RGDRGD)30-amino-acid polypeptide featuring a terminally fused RGDRGD hexapeptide at the N terminus.The active endostatin fragment of PEP06 directly targets tumor cells and exerts an antitumoral effect.However,little is known about the kinetics and degradation products of PEP06 in vitro or in vivo.In this study,we investigated the in vitro metabolic stability of PEP06 after it was incubated with living cells obtained from animals of different species;we further identified the degradation characteristics of its cleavage products.PEP06 underwent rapid enzymatic degradation in multiple types of living cells,and the liver,kidney,and blood play important roles in the metabolism and clearance of the peptides resulting from the molecular degradation of PEP06.We identified metabolites of PEP06 using full-scan mass spectrometry(MS)and tandem MS(MS2),wherein 43 metabolites were characterized and identified as the degradation metabolites from the parent peptide,formed by successive losses of amino acids.The metabolites were C and N terminal truncated products of PEP06.The structures of 11 metabolites(M6,M7,M16,M17,M21,M25,M33,M34,M39,M40,and M42)were further confirmed by comparing the retention times of similar full MS spectrum and MS2 spectrum information with reference standards for the synthesized metabolites.We have demonstrated the metabolic stability of PEP06 in vitro and identified a series of potentially bioactive downstream metabolites of PEP06,which can support further drug research.

An UPLC-MS/MS method to monitor Estriol injection and comparison of pharmacokinetic characteristics after irradiation

Objective:To develop an UPLC-MS/MS method for the accurate quantification of Estriol(E3),a new radioprotective agent,and observe the variation in pharmacokinetic characteristics of E3 after irradiation.As a hormone drug,the gender differences of E3 metabolism were also concerned here.Methods:Various chromatographic and mass spectrometric conditions of E3 were optimized.The specificity,linearity,precision and accuracy of UPLC-MS/MS method were validated.Twenty SD rats,half male and half female,were administered with intramuscular(im)injection of 2.7 mg/kg E3,and then divided randomly into two groups,sham-irradiated group(Con)and irradiated group(IR).IR group was irradiated to 7 Gy ofγ-rays.Blood samples were collected at different times post-irradiation and E3 concentrations were detected.The changes of concentration-time variation and pharmacokinetic parameters for E3 after irradiation were investigated,together with metabolic differences between male and female rats.Results:The range of the calibration curve of UPLC-MS/MS for E3 was 1.00–200.0 ng/mL.Con group reached maximum concentration(Cmax)(77.57±18.71)ng/mL at(0.68±0.29)h(Tmax)after im injection.The drug concentration-time profiles and pharmacokinetic parameters of E3 were consistent before and after irradiation.The areas under time curve(AUC0-t)of E3 were(353±74)h⋅ng/mL for Con group,and(299±74)h⋅ng/mL for IR group(P>0.05).There were also no statistical differences in pharmacokinetic parameters between female and male rats.The elimination half-lifes(T1/2)of males and females were(3.02±0.68)h and(3.01±0.42)h in Con group,and(3.64±0.51)h and(3.38±0.60)h in IR group,respectively(P>0.05).Conclusion:A rapid and sensitive UPLC-MS/MS method for determination of E3 was established.The pharmacokinetic characteristics of E3 in rat were not affected by 7 Gy irradiation and gender differences.This study provided a theoretical basis for the development and application of new radiation injury treatment drug。