Alkaline sphingomyelinase deficiency impairs intestinal mucosal barrier integrity and reduces antioxidant capacity in dextran sulfate sodium-induced colitis

BACKGROUND

Ulcerative colitis is a chronic inflammatory disease of the colon with an unknown etiology. Alkaline sphingomyelinase (alk-SMase) is specifically expressed by intestinal epithelial cells, and has been reported to play an anti-inflammatory role. However, the underlying mechanism is still unclear.

AIM

To explore the mechanism of alk-SMase anti-inflammatory effects on intestinal barrier function and oxidative stress in dextran sulfate sodium (DSS)-induced colitis.

METHODS

Mice were administered 3% DSS drinking water, and disease activity index was determined to evaluate the status of colitis. Intestinal permeability was evaluated by gavage administration of fluorescein isothiocyanate dextran, and bacterial translocation was evaluated by measuring serum lipopolysaccharide. Intestinal epithelial cell ultrastructure was observed by electron microscopy. Western blotting and quantitative real-time reverse transcription-polymerase chain reaction were used to detect the expression of intestinal barrier proteins and mRNA, respectively. Serum oxidant and antioxidant marker levels were analyzed using commercial kits to assess oxidative stress levels.

RESULTS

Compared to wild-type (WT) mice, inflammation and intestinal permeability in alk-SMase knockout (KO) mice were more severe beginning 4 d after DSS induction. The mRNA and protein levels of intestinal barrier proteins, including zonula occludens-1, occludin, claudin-3, claudin-5, claudin-8, mucin 2, and secretory immunoglobulin A, were significantly reduced on 4 d after DSS treatment. Ultrastructural observations revealed progressive damage to the tight junctions of intestinal epithelial cells. Furthermore, by day 4, mitochondria appeared swollen and degenerated. Additionally, compared to WT mice, serum malondialdehyde levels in KO mice were higher, and the antioxidant capacity was significantly lower. The expression of the transcription factor nuclear factor erythroid 2-related factor 2 (Nrf2) in the colonic mucosal tissue of KO mice was significantly decreased after DSS treatment. mRNA levels of Nrf2-regulated downstream antioxidant enzymes were also decreased. Finally, colitis in KO mice could be effectively relieved by the injection of tertiary butylhydroquinone, which is an Nrf2 activator.

CONCLUSION

Alk-SMase regulates the stability of the intestinal mucosal barrier and enhances antioxidant activity through the Nrf2 signaling pathway.

[Immunogenicity and safety of a booster vaccination with an inactivated severe acute respiratory syndrome coronavirus 2 vaccine in adults aged 18 to 59 years]

Objective: To assess the immunogenicity and safety of a booster vaccination with an inactivated severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) vaccine. Methods: The phase Ⅱ trial of an inactivated SARS-CoV-2 vaccine was conducted by Jiangsu Provincial Center for Disease Control and Prevention (CDC) since October 2020. The subjects were healthy adults aged 18-59 years, excluding pregnant, and not breastfeeding women. The primary vaccination schedule groups were 0-14 d 5 μg, 0-14 d 10 μg, 0-28 d 5 μg and 0-28 d 10 μg, respectively. And 50 participants in each group, a total of 200, who have received 2-doses primary vaccination were selected in ascending order of the study number and vaccinated with a booster dose (same dosage as primary vaccination) at the 6th months after post the primary vaccination (30-day window period). Blood samples were collected before and after boosting and tested for the geometric mean titers (GMT) and seroconversion of live virus neutralizing antibody, pseudovirus neutralizing antibody and receptor-binding-domain (RBD) IgG antibody. Adverse events (AE) were collected and assessed within 28 days after boosting. Results: The ages of subjects in group 0-14 d 5 μg, 0-14 d 10 μg, 0-28 d 5 μg and 0-28 d 10 μg were (43.98±9.58), (43.46±9.34), (42.56±9.08) and (43.94±11.05) years old, respectively (P=0.877). Sex ratios were balanced among the 4 groups (P=0.331). The live virus neutralizing antibody GMT (95%CI) in group 0-14 d 5 μg, 0-14 d 10 μg, 0-28 d 5 μg and 0-28 d 10 μg increased from 4.07 (3.30-5.04), 3.75 (3.08-4.55), 8.33 (7.01-11.11) and 7.69 (6.19-9.57) before the booster vaccination to 284.84 (215.28-376.86), 233.05 (178.61-304.08), 274.81 (223.64-337.68) and 280.77 (234.59-336.04) in 28 days after the booster vaccination, respectively. The rates of live virus neutralizing antibody seroconversion were all 100% in the 4 groups. The AE incidences following booster vaccination were 18.0% (9 cases), 4.0% (2 cases), 12% (6 cases), and 12% (6 cases) in the 4 groups(P=0.182). No AE was graded as level 3 or worse. No serious AE was reported. Conclusion: One booster vaccination of an inactivated SARS-CoV-2 vaccine administered 6 months after primary vaccination showed good immunogenicity and safety.

Laparoscopic uterovaginal anastomosis in patients with congenital cervicovaginal atresia: An institutional experience with 23 patients

OBJECTIVE

To introduce our experience of laparoscopic uterovaginal anastomosis and operative outcomes following this technique and update the clinical management of congenital cervicovaginal atresia.

STUDY DESIGN

Between March 2015 and January 2019, twenty-three patients with congenital cervicovaginal atresia underwent laparoscopic uterovaginal anastomosis and Luohu procedure. Their clinical characteristics, surgical outcomes and follow-up data were retrospectively reviewed.

RESULTS

The mean ± SD age of the cases was 16.4 ± 4.0 (11-26) years. All patients had a history of primary amenorrhea and cyclical abdominal pain, and the average delay in diagnosis from first symptoms was 33.5 ± 38 (1-156) months. Most of the patients had 1-3 cm long vaginal pouch. The operative procedure lasted 125 ± 32 (80-190) min. The average vaginal length at 1 month was 7.9 ± 1.3 (range 6-9) cm. All patients showed resumption of menstruation. The patients were followed for a mean of 27 ± 13 (12-56) months. During the follow-up, cervical stenosis did not occur in any of the cases.

CONCLUSION

Laparoscopic uterovaginal anastomosis with Luohu procedure provided a minimally invasive, safe, and effective surgical option for the patients with congenital cervicovaginal atresia. The technique is uncomplicated, easy to learn and perform, and provides a functional and anatomic satisfactory result. No special surgical instruments are required with this technique.

[Pathological changes of the spleen in ten patients with coronavirus disease 2019(COVID-19) by postmortem needle autopsy]

Objective: To study the pathological changes of the spleen in patients with COVID-19 and to analyze the relationship between the weakened immune system and splenic lesions. Methods: Postmortem needle autopsies from the spleen were carried out on 10 patients who died from COVID-19 in Wuhan. Routine hematoxylin and eosin (HE) staining was used to observe the pathological changes. The changes of lymphocytes were studied further with immunohistochemistry.RT-PCR was used to detect 2019-nCoV RNA in the spleen. In addition,the Epstein-Barr virus (EBV) was detected by in situ hybridization, and coronavirus particles were detected by transmission electron microscopy in 2 cases. Results: There were 7 males and 3 females, with an average age of 68.3 years.Of the 10 cases, 4 had cancer history and another 4 had other underlying diseases respectively.Cough, fever, malaise and dyspnea were the main clinical symptoms.The time from onset to death was 15-45 days.Ten cases patients had normal or slight increase in peripheral blood leukocyte count in the early stage of the disease, 6 cases had significant increase before death. Five patients' peripheral blood lymphocyte count decreased in the early stage of the disease, and 10 patients' peripheral blood lymphocyte count decreased significantly before the disease progressed or died. Seven cases were treated with corticosteroid (methylprednisolone ≤40 mg/d, not more than 5 days). Histopathological examination showed that the cell composition of the spleen decreased, white pulp atrophied at different levels, meanwhile lymphoid follicles decreased or absent;in addition, the ratio of red pulp to white pulp increased with varying degrees. In 7 cases, more neutrophil infiltration was found, and in 5 cases, scattered plasma cell infiltration was found. Macrophage proliferation and hemophagocytic phenomena in a few cells were found in a case. Meanwhile, necrosis and lymphocyte apoptosis were detected in 2 cases, small artery thrombosis and spleen infarction in 1 case, and fungal infection in 1 case. The results of immunohistochemistry showed that the T and B lymphocyte components of the spleen in all cases decreased in varying degrees. CD20(+) B cells were found to accumulate in the lymphoid sheath around the splenic artery in 8 cases. However, CD20 and CD21 immunostaining in 2 cases showed that the number of white pulp was almost normal, and splenic nodules were atrophic. CD3(+), CD4(+) and CD8(+)T cells were decreased. In 9 cases,CD68(+) macrophages were no significant changes in the distribution and quantity. While more CD68(+) cells were found in the medullary sinuses of 1 case (related to fungal infection). Few CD56(+) cells were found. EBV was negative by in situ hybridization. RT-PCR was used to detect the nucleic acid of 2019-nCoV. One of 10 cases was positive, 39 years old,who was the youngest patient in this group, and the other 9 cases were negative. Coronavirus particles were found in the cytoplasm of macrophage under electron microscope in 2 cases. Conclusions: The death of COVID-19 occurs mainly in the elderly, and some cases have no underlying diseases. Spleen may be one of the organs directly attacked by the virus in some patients who died from COVID-19. T and B lymphocyte in the spleen decrease in varying degrees, lymphoid follicles are atrophied, decreased or absent, and the number of NK cells do not change significantly. And the pathological changes of the spleen are not related to the use of low dose corticosteroid, which may be related to the direct attack of virus and the attack of immune system on its own tissues.

[The understanding of Epstein-Barr virus associated lymphoproliferative disorder]

In recent years, there are increasing articles concerning Epstein-Barr virus associated lymphoproliferative disorder (EBV+ LPD), and the name of EBV+ LPD is used widely. However, the meaning of EBV+ LPD used is not the same, which triggered confusion of the understanding and obstacles of the communication. In order to solve this problem. Literature was reviewed with combination of our cases to clarify the concept of EBV+ LPD and to expound our understanding about it. In general, it is currently accepted that EBV+ LPD refers to a spectrum of lymphoid tissue diseases with EBV infection, including hyperplasia, borderline lesions, and neoplastic diseases. According to this concept, EBV+ LPD should not include infectious mononucleosis (IM) and severe acute EBV infection (EBV+ hemophagocytic lymphohistiocytosis, fatal IM, fulminant IM, fulminant T-cell LPD), and should not include the explicitly named EBV+ lymphomas (such as extranodal NK/T cell lymphoma, aggressive NK cell leukemia, Burkitt lymphoma, and Hodgkin lymphoma, etc.) either. EBV+ LPD should currently include: (1) EBV+ B cell-LPD: lymphomatoid granulomatosis, EBV + immunodeficiency related LPD, chronic active EBV infection-B cell type, senile EBV+ LPD, etc. (2) EBV+ T/NK cell-LPD: CAEBV-T/NK cell type, hydroa vacciniforme, hypersensitivity of mosquito bite, etc. In addition, EBV+ LPD is classified, based on the disease process, pathological and molecular data, as 3 grades: grade1, hyperplasia (polymorphic lesions with polyclonal cells); grade 2, borderline (polymorphic lesions with clonality); grade 3, neoplasm (monomorphic lesions with clonality). There are overlaps between EBV+ LPD and typical hyperplasia, as well as EBV+ LPD and typical lymphomas. However, the most important tasks are clinical vigilance, early identification of potential severe complications, and treating the patients in a timely manner to avoid serious complications, as well as the active treatment to save lives when the complications happened.

Phenotypic and clinical aspects of Mayer-Rokitansky-Küster-Hauser syndrome in a Chinese population: an analysis of 594 patients

OBJECTIVE

To analyze the phenotypic and clinical aspects of Mayer-Rokitansky-Küster-Hauser (MRKH) syndrome.

DESIGN

Cross-sectional study.

SETTING

University hospital.

PATIENT(S)

Five hundred and ninety-four patients with MRKH syndrome.

INTERVENTION(S)

Clinical examination, abdominal or perineal/rectal ultrasound, magnetic resonance imaging, hormonal profile, karyotype, and laparoscopy.

MAIN OUTCOME MEASURE(S)

Clinicopathologic data, VCUAM (vagina cervix uterus adnex-associated malformation) classification, types with cycle phase, and karyotype.

RESULT(S)

We identified associated malformations in 43 out of 594 (7.2%) cases of MRKH. The 594 patients could be grouped into hormone phases: 53.7% follicular, 35.2% luteal, and 11.1% ovulatory. The major karyotype of MRKH patients was 46,XX; abnormal karyotypes were found in two cases.

CONCLUSION(S)

A lower proportion of associated malformations were found when compared with those provided in the current literature. Renal anomalies were the most frequent associated malformations, and most of the patients presented with a normal karyotype. Given the large cohort of this study, the lower malformation rates might be related to geographic or referral patterns, so further investigation is warranted.

Study and clinical application of a porcine biomembrane for the repair of dural defects

A biomembrane was developed from pig peritoneum treated with 0.65% glutaraldehyde. This was evaluated for use as a dural substitute in an animal model and in a patient population. After being treated with the glutaraldehyde solution, the biomembrane lost its antigenicity while its collagen underwent an irreversible cross-linking reaction, causing it to become a stable nonviable polymer resistant to absorption by the host. The biomembrane was used experimentally in 43 procedures on 20 dogs and was applied clinically in 614 patients. The results demonstrated that it is an acceptable material for the repair of dural defects, with the following advantages: 1) it is nontoxic to the body and brain tissues, with minimal tissue reaction; 2) its biophysical properties facilitate watertight closure with sutures; 3) its distensibility makes it suitable for decompressive surgical dural repair; and 4) its visceral surface is extremely smooth, causing virtually no adhesions with the brain tissue while the outer surface readily heals with the subcutaneous tissue.