Autonomic neural regulation in mediating the brain-bone axis: mechanisms and implications for regeneration under psychological stress

Efficient regeneration of bone defects caused by disease or significant trauma is a major challenge in current medicine, which is particularly difficult yet significant under the emerging psychological stress in the modern society. Notably, the brain-bone axis has been proposed as a prominent new concept in recent years, among which autonomic nerves act as an essential and emerging skeletal pathophysiological factor related to psychological stress. Studies have established that sympathetic cues lead to impairment of bone homeostasis mainly through acting on mesenchymal stem cells (MSCs) and their derivatives with also affecting the hematopoietic stem cell (HSC)-lineage osteoclasts, and the autonomic neural regulation of stem cell lineages in bone is increasingly recognized to contribute to the bone degenerative disease, osteoporosis. This review summarizes the distribution characteristics of autonomic nerves in bone, introduces the regulatory effects and mechanisms of autonomic nerves on MSC and HSC lineages, and expounds the crucial role of autonomic neural regulation on bone physiology and pathology, which acts as a bridge between the brain and the bone. With the translational perspective, we further highlight the autonomic neural basis of psychological stress-induced bone loss and a series of pharmaceutical therapeutic strategies and implications toward bone regeneration. The summary of research progress in this field will add knowledge to the current landscape of inter-organ crosstalk and provide a medicinal basis for the achievement of clinical bone regeneration in the future.

A polysaccharide from salviae miltiorrhizae radix inhibits weight gain of mice with high-fat diet via modulating intestinal bacteria

BACKGROUND

Obesity, a global chronic disease, has been recognized as a severe risk to health. In our study, a novel polysaccharide named ARS was isolated and purified from aerial part of salviae miltiorrhizae radix. Our aim is to investigate the weight-reducing effect of a polysaccharide from salviae miltiorrhizae radix on mice fed a high-fat diet.

RESULTS

The novel polysaccharide ARS mainly consisted of glucose and galactose with a molar ratio of 0.59:1.00. We found that treatment with ARS could inhibit weight gain of mice fed a high-fat diet via modulating the intestinal bacteria. Moreover, we surveyed its mechanism in mice, and the gut microbiota sequencing results demonstrated that ARS can reverse or resist high-fat-diet-induced significant weight gain or obesity by increasing the diversity of gut microbiota and optimizing the ratio of Firmicutes to Bacteroidetes. Phylum and species analysis of gut microbiota demonstrated that obesity caused by a high-fat diet was accompanied by significant changes in the microbial communities, but ARS could reverse the disturbance of gut microbiota induced by the high-fat diet to maintain homeostasis.

CONCLUSION

Overall, our findings suggested a new function of ARS in regulating gut microbiota, which provides a theoretical basis for the development of high-quality ARS functional foods and the application of dietary supplements. © 2023 Society of Chemical Industry.

Application of tensor fascia lata perforator flap in head and neck reconstruction

The aim of this study was to describe the authors' experience in head and neck reconstruction with the tensor fascia lata perforator flap (TFLPF). Between April 2009 and August 2020, 16 patients underwent head and neck reconstruction with a TFLPF. The flaps were designed in a vertical or transverse fashion based on perforators traveling along the medial or lateral aspect of the posterior edge of the tensor fascia lata muscle. Clinical details and postoperative results were recorded and analyzed. The size of the flap ranged from 7 × 5 cm2 to 25 × 9 cm2. The perforators were mostly septocutaneous (11 patients), allowing a simple and straightforward dissection of the perforator and TFLPF in most patients. There were either one or two perforators in all cases. The overall flap survival rate was 100%. All of the flaps healed uneventfully with no delayed wound healing or donor site dysfunction. Follow-up ranged from 18 to 120 months, during which all patients experienced satisfactory functional and aesthetic results, without serious complications at either the recipient or donor site. The TFLPF is a pliable and reliable flap that could be a first choice in selected head and neck reconstruction cases.

[Clinical effects of scalp flaps pedicled with superficial temporal artery parietal branch in repairing facial destructive burn wounds]

Objective: To explore the clinical effects of scalp flaps pedicled with superficial temporal artery parietal branch in repairing facial destructive burn wounds. Methods: A retrospective observational study was conducted. From January 2016 to December 2021, 15 patients with facial destructive burns who met the inclusion criteria were admitted to Zhengzhou First People's Hospital, including 11 males and 4 females, aged 22 to 79 years. Two patients were complicated with unilateral eyeball destructive burns, two patients were complicated with unilateral auricle defects, eight patients were complicated with lip and cheek defects, and three patients were complicated with lip, cheek, and unilateral nasal alar defects. The burn wound areas ranged from 9 cm×6 cm to 13 cm×10 cm. The scalp flaps pedicled with superficial temporal artery parietal branch, with the area of 10 cm×7 cm to 15 cm×11 cm, were designed, excised, and transferred for repairing burn wounds. The secondary wounds at the donor sites were repaired with medium-thickness scalp grafts. According to patient's needs, the hairs grew at the facial transplanted flap were removed by laser at 2 weeks after the flap was completely viable, or the expanded scalp flap was used to treat the secondary alopecia in the flap donor area of the head at 3 months after the primary wound repair. The survival of the flap/skin graft and the wound healing of the donor and recipient areas after the primary wound repair were recorded. During the follow-up, the appearance of the flap, the scar hyperplasia at the suture site, the repair effect of facial functional parts, the treatment effects of laser hair removal and secondary alopecia treatment at the flap donor site were observed; the patient's satisfaction with the overall repair effect was inquired. Results: After the primary wound repair, all the flaps transplanted to the burn wounds and the skin grafts transplanted to the secondary wounds of the flap donor sites survived well, and the wounds at the donor and recipient sites of flap healed well. The color, texture, and thickness of flap were basically the same as those of normal facial skin, and the scar at the suture site was slight during 3 to 18 months of follow-up period after the primary wound repair. In 11 patients complicated with lip defects, the oral integrity, and the opening and closing functions of mouth were restored with the mouth opening being 2.0-2.5 cm and no microstomia; all the patients could carry out basic language communication, 8 of them could take regular food, and 3 of them could take soft food. The wounds in two patients with unilateral eyeball destructive burns were repaired. In 2 patients complicated with auricle defects, the wounds were repaired, and the external auditory canals were normal. In 3 patients complicated with unilateral nasal alar defects, their noses had poor appearance with reduced nostrils. No hair growth was observed in the facial flap sites after treatment of laser hair removal in 8 patients. Five patients were successfully treated with expanded scalp flaps for secondary alopecia in the flap donor area of the head. The patients were all satisfied with the overall repair effect. Conclusions: The scalp flap pedicled with superficial temporal artery parietal branch has abundant blood supply and is suitable for repairing the wounds in facial destructive burns. It is easy to transfer and can better restore the appearance and function of the recipient area with minimal damage to the flap donor area, which is worthy of clinical promotion.

Neratinib + fulvestrant + trastuzumab for HR-positive, HER2-negative, HER2-mutant metastatic breast cancer: outcomes and biomarker analysis from the SUMMIT trial

BACKGROUND

HER2 mutations are targetable alterations in patients with hormone receptor-positive (HR+) metastatic breast cancer (MBC). In the SUMMIT basket study, patients with HER2-mutant MBC received neratinib monotherapy, neratinib + fulvestrant, or neratinib + fulvestrant + trastuzumab (N + F + T). We report results from 71 patients with HR+, HER2-mutant MBC, including 21 (seven in each arm) from a randomized substudy of fulvestrant versus fulvestrant + trastuzumab (F + T) versus N + F + T.

PATIENTS AND METHODS

Patients with HR+ HER2-negative MBC with activating HER2 mutation(s) and prior cyclin-dependent kinase 4/6 inhibitor (CDK4/6i) therapy received N + F + T (oral neratinib 240 mg/day with loperamide prophylaxis, intramuscular fulvestrant 500 mg on days 1, 15, and 29 of cycle 1 then q4w, intravenous trastuzumab 8 mg/kg then 6 mg/kg q3w) or F + T or fulvestrant alone. Those whose disease progressed on F + T or fulvestrant could cross-over to N + F + T. Efficacy endpoints included investigator-assessed objective response rate (ORR), clinical benefit rate (RECIST v1.1), duration of response, and progression-free survival (PFS). Plasma and/or formalin-fixed paraffin-embedded tissue samples were collected at baseline; plasma was collected during and at end of treatment. Extracted DNA was analyzed by next-generation sequencing.

RESULTS

ORR for 57 N + F + T-treated patients was 39% [95% confidence interval (CI) 26% to 52%); median PFS was 8.3 months (95% CI 6.0-15.1 months). No responses occurred in fulvestrant- or F + T-treated patients; responses in patients crossing over to N + F + T supported the requirement for neratinib in the triplet. Responses were observed in patients with ductal and lobular histology, 1 or ≥1 HER2 mutations, and co-occurring HER3 mutations. Longitudinal circulating tumor DNA sequencing revealed acquisition of additional HER2 alterations, and mutations in genes including PIK3CA, enabling further precision targeting and possible re-response.

CONCLUSIONS

The benefit of N + F + T for HR+ HER2-mutant MBC after progression on CDK4/6is is clinically meaningful and, based on this study, N + F + T has been included in the National Comprehensive Cancer Network treatment guidelines. SUMMIT has improved our understanding of the translational implications of targeting HER2 mutations with neratinib-based therapy.

Ceruloplasmin regulating fibrosis in orbital fibroblasts provides a novel therapeutic target for Graves' orbitopathy

PURPOSE

In diagnosing the pathogenesis of Graves' orbitopathy (GO), there is a growing interest in fibrosis generated by orbital fibroblasts (OFs); nevertheless, the involvement of ceruloplasmin (CP) in OFs remains unknown.

METHODS

Differentially expressed genes (DEGs) were identified through bioinformatic analysis. OFs were isolated from orbital tissue and identified with immunofluorescent staining. The levels of DEGs were validated in GO tissue samples and TGF-β-challenged OFs, and CP was selected for the following laboratory investigations. CP overexpression or knockdown was achieved, and cell viability and fibrosis-associated proteins were investigated to assess the cell phenotype and function. Signaling pathways were subsequently investigated to explore the mechanism of CP function in OFs.

RESULTS

CP and cathepsin C (CTSC) are two overlapped DEGs in GSE58331 and GSE105149. OFs were isolated and identified through fibrotic biomarkers. CP and CTSC were downregulated in GO tissue samples and TGF-β-challenged OFs. CP overexpression or knockdown was achieved in OFs by transducing a CP overexpression vector or small interfering RNA against CP (si1-CP or si2-CP) and verified using a qRT-PCR. CP overexpression inhibited cell viability and reduced the levels of α-SMA, vimentin, fibronectin, and collagen I, whereas CP knockdown exerted opposite effects on OFs. CP overexpression inhibited the phosphorylation of Smad3, Erk1/2, p38, JNK, and AKT; conversely, CP knockdown exerted opposite effects on the phosphorylation of factors mentioned above.

CONCLUSION

CP was downregulated in GO and suppressed the expression of fibrosis-associated proteins in both GO and normal OFs. CP might serve as a promising therapeutic agent in the treatment regimens for GO.

[Discussion on the history of Pinelliae Rhizoma Praeparatum(Fa banxia) Processing]

Before the Song Dynasty, the main processing method of Pinelliae Rhizoma was soup washing. The "new method" in Taiping Huimin Heji JuFang is a processing method that concocted with Ginger,white alum and starter-making.The "Fa Banxia" in the Yuan Dynasty's Yuyuan Yaofang comes from the Taiping Huimin Heji JuFang, and the Fa Wen Banxia, Fa Bai Banxia, and Fa Hong Banxia are the processing methods of patent medicine with a variety of other herbs.Fa Banxia appeared in the Ming Dynasty, and its auxiliary materials were ginger and white alum, and medical formulary began to include formulas containing Fa Banxia. Bencao Gangmu abbreviates the Yuan Dynasty's Fabai Banxia as "Fa Banxia", and is elaborated under the item attached "prescription" item instead of the "treatment". In the literature of Materia Medica, it is recorded that the preparation of auxiliary materials in Fa Banxia increased, including lime, licorice, soap horn, and simple nitro.After Daoguang in the Qing Dynasty, the Fa Banxia in famous medical cases was more used, and at that time, Fa Banxia was Xian Banxia. There are two recipes for Xian Banxia: one is made with seven processes, and the other is soaked in alum licorice water. During the Republican period, Zhang Cigong also pointed out that Fa Banxia was sliced Xian Banxia after rinsing and boiling, while the preparation method of Xian Banxia was Banxia made of ginger and white alum.Ye Juquan pointed out that the so-called "fa" is neither an ancient method nor a new method, questioning the process of repeated immersion in Banxia. After 1949, the questioning of Fa Banxia continued unceasing.Influenced by this, the 1960 edition Beijing Traditional Chinese Medicine Slice Cutting Experience included the method of soaking alum, licorice ,lime water, and was included in the 1963 edition of the Pharmacopoeia of the People's Republic of China.The 1985 version reduced the soaking time and eliminated the soaking process of alum based on the 1963 version, and this method is still used today.

[Curative effects of ultrathin anterolateral femoral flap in one-stage split-finger repair of palmar combined with multiple finger wounds]

Objective: To explore the curative effects of ultrathin anterolateral femoral flap in one-stage split-finger repair of palmar combined with multiple finger wounds. Methods: A retrospective observational study was conducted. From October 2016 to June 2018, 20 patients with wounds on palms and multiple fingers who met the inclusion criteria were admitted to Zhengzhou First People's Hospital, including 15 males and 5 females, aged 18 to 77 years. After debridement, the wound area was 8 cm×4 cm-17 cm×12 cm. The wound was repaired by ultrathin anterolateral femoral flap with area of 9 cm×5 cm to 19 cm×13 cm. According to the wound condition of finger, the finger division was performed in one stage, and the length-to-width ratio of the split-finger flap was 2.0:1.0-2.5:1.0. During the surgery, the descending branches of lateral circumflex femoral artery and accompanying vein of flap were anastomosed end-to-end to the radial artery and vein in the recipient area, respectively, and the anterolateral femoral cutaneous nerve of flap was bridged with the superficial branch of radial nerve in the recipient area. The wounds in the donor area of flap in 14 patients were sutured directly, the wounds in the donor area of flap in 3 patients were repaired by relay superficial iliac circumflex artery perforator flap, and the wounds in the donor area of flap in 3 patients were covered by free trunk medium-thick skin graft. The survival of flap, occurrence of vascular crisis and other complications, and healing of wounds in the donor area of flap were recorded. The appearance of flap, scar hyperplasia in the donor and recipient areas and the patients' satisfaction with the shape and function of the donor and recipient areas were followed up. In 1 year after surgery, the two-point discrimination distance of the flap was measured, and the recovery of hand function was evaluated by the trial standard for the evaluation of the functions of the upper limbs of the Hand Surgery Society of the Chinese Medical Association. Results: The flaps of 17 patients survived without vascular crisis or other complications after surgery. The flap of 1 patient had poor blood circulation and partial necrosis, and the wound was healed 14 days after dressing change and grafting of split-thickness skin graft from head. Two patients had mild cyanosis at the margin of flap after surgery, which disappeared spontaneously 5 days later. Incisions at donor site, relay flaps, and skin grafts of all patients survived well. After surgery, the color and texture of flap were basically the same as that of the normal skin of hand, and linear scars were observed in the donor and recipient areas. The patients were satisfied with the recovery of appearance and function of donor and recipient areas. After 1 year of follow-up, the patients' hand sensory function recovered well, the two-point discrimination distance of flap was 4-6 mm, and the recovery of hand function was evaluated as excellent in 18 cases and good in 2 cases. Conclusions: The ultrathin anterolateral femoral flap in repairing the palmar combined with multiple finger wounds in one-stage split-finger can significantly reduce the number of surgeries and improve the function and beauty of the hand, so it is worthy of clinical promotion.

[Effect of hollow compression screw internal fixation in treating McCrory-Bladin type Ⅱ lateral process fracture of the talus: open versus arthroscopy surgery]

In order to explore the clinical efficacy of hollow compression screw internal fixation in the treatment of lateral process fracture of the talus under open surgery versus arthroscopy procedure, a retrospective cohort study was conducted to analyze the clinical data of 33 patients with lateral process fracture of the talus admitted to Xuzhou Central Hospital from January 2019 to December 2021. There were 19 males (19 feet) and 14 females (14 feet), aged 18 to 50 years, with an average age of (32.2±9.3) years. According to the modified McCrory-Bladin classification, all patients were classified as type Ⅱ. Based on the different surgical methods, the patients were divided into the arthroscopy group (21 cases, treated with double-tunnel subtalar arthroscopy combined with hollow compression screw internal fixation) and the open group (12 cases, treated with open reduction and internal fixation with hollow compression screw). The operation time was observed and the surgical effects were evaluated using the visual analogue scale (VAS) of pain, the American Orthopedic Foot and Ankle Society (AOFAS) ankle-hindfoot score, the Foot Function Index (FFI), and the Foot and Ankle Ability Measure (FAAM), which includes the FAAM-ADL (activity of daily living subscale) and the FAAM-S (sport subscale). All the patients of the two groups achieved stage Ⅰ wound healing. On the first day after the operation, the mean VAS score of the arthroscopy group was 2.4±0.7, which was significantly lower than that of the open group (3.4±1.6) (P=0.020). No significant difference was observed in terms of the follow-up time, operation time and AOFAS score between the two groups (all P>0.05). The FFI score of the arthroscopy group was significantly lower than that of the open group, and the FAAM-ADL and FAAM-S scores were significantly higher than those in the open group (all P<0.05). Two cases of dorsal foot numbness occurred in the open group after the operation, and the incidence of complications was not significantly different from that of the arthroscopy group (P=0.054). For McCrory-Bladin type Ⅱ lateral process fracture of the talus, the use of compression screw internal fixation could achieve reliable results, however, compared to open surgery, arthroscopy procedure obtained mini trauma and better functions.

[Value of contrast-enhanced ultrasonography in detection of endoleak after endovascular repair of infrarenal abdominal aortic aneurysm]

Objective: To investigate the value of contrast-enhanced ultrasound in detecting endoleak after endovascular repair of infrarenal abdominal aortic aneurysm (EVAR). Methods: The postoperative follow-up data of 102 patients with infrarenal abdominal aortic aneurysm treated with EVAR in Tianjin Medical University General Hospital from August 2015 to December 2021 were retrospectively analyzed. There were 79 males and 23 females, aged 50-91 (69.6±7.6) years old. Using CT angiography (CTA) as the gold standard for diagnosing endoleaks, the effectiveness of contrast-enhanced ultrasound and CDUS in detecting endoleaks was evaluated by paired design chi-square test, and the Kappa value was calculated for consistency test. Patients were divided into groups according to body mass index (BMI), and the number of false-negative endoleaks detected by contrast-enhanced ultrasound in each group was calculated, and its ratio to the actual number of endoleaks was calculated to evaluate whether BMI was related to false-negative ultrasound-enhanced ultrasound. Results: A total of 203 follow-up visits met the inclusion criteria. Endoleaks were detected 36 times (17.7%) by CTA, 31 times (15.3%) by contrast-enhanced ultrasound, 16 times (7.9%) by CDUS, and they all detected type Ⅰ, type Ⅱ and type Ⅲ endoleaks. There was no significant difference between contrast-enhanced ultrasound and CTA in endoleak detection rate and determination of endoleak types (endoleak detection rate: 15.3% vs 17.7%; determination of endoleak types: type Ⅰ 4 vs 4, type Ⅱ 26 vs 31, type Ⅲ 1 vs 1; all P>0.05). CDUS and CTA had statistically significant differences in the detection rate of endoleaks and determination of endoleak types (endoleak detection rate: 7.9% vs 17.7%; determination of endoleak types: type Ⅰ 4 vs 4, type Ⅱ 11 vs 31, type Ⅲ 1 vs 1; all P<0.001). Compared with CTA, contrast-enhanced ultrasound has a sensitivity of 83.3%, a specificity of 99.4%, a Youden index of 0.827, a coincidence rate of 96.6%, a positive predictive value of 96.8%, a negative predictive value of 96.5%, and a Kappa value of 0.875(P<0.001). The two showed excellent diagnostic consistency. All 6 endoleaks not detected by contrast-enhanced ultrasound were type Ⅱ endoleak that did not require treatment, and 3(15.8%) occurred in obese patients with a BMI≥32 kg/m². Compared with CTA, CDUS had a sensitivity of 38.9%, a specificity of 98.8%, a Youden index of 0.377, a coincidence rate of 88.2%, a positive predictive value of 87.5%, a negative predictive value of 88.2%, and a Kappa value of 0.482 (P<0.001). The two showed moderate diagnostic agreement. The correlation coefficient of the maximum diameter of aneurysms measured by ultrasound and CT was r=0.873(P<0.001). Conclusions: Contrast-enhanced ultrasound is accurate in detecting endoleak after infrarenal EVAR, and its sensitivity to endoleak detection in obese patients with BMI≥32 kg/m² will be reduced. CDUS is not suitable for detection of endoleak after infrarenal EVAR, but it can be used to monitor the change of the largest diameter of aneurysm after EVAR.

Transcriptomic and methylomic analyses provide insights into the molecular mechanism and prediction of heterosis in rice

Heterosis has been widely used in multiple crops. However, the molecular mechanism and prediction of heterosis remains elusive. We generated five F1 hybrids [four showing better-parent heterosis (BPH) and one showing mid-parent heterosis], and performed the transcriptomic and methylomic analyses to identify the candidate genes for BPH and explore the molecular mechanism of heterosis and the potential predictors for heterosis. Transcriptomic results showed that most of the differentially expressed genes shared in the four better-parent hybrids were significantly enriched into the terms of molecular function, and the additive and dominant effects played crucial roles for BPH. DNA methylation level, especially in CG context, significantly and positively correlated with grain yield per plant. The ratios of differentially methylated regions in CG context in exons to transcription start sites between the parents exhibited significantly negative correlation with the heterosis levels of their hybrids, as was further confirmed in 24 pairwise comparisons of other rice lines, implying that this ratio could be a feasible predictor for heterosis level, and this ratio of less than 5 between parents in early growth stages might be a critical index for judging that their F1 hybrids would show BPH. Additionally, we identified some important genes showing differential expression and methylation, such as OsDCL2, Pi5, DTH2, DTH8, Hd1 and GLW7 in the four better-parent hybrids as the candidate genes for BPH. Our findings helped shed more light on the molecular mechanism and heterosis prediction.

Early adjunctive diagnostic value of contrast-enhanced ultrasound-related quantitative parameter and its relationship with micro-perfusion of nontraumatic necrosis of femoral head

OBJECTIVE

The aim of this study is to explore the early diagnostic value of contrast-enhanced ultrasound (CEUS)-related quantitative parameter and its relationship with the micro-perfusion of nontraumatic necrosis of the femoral head.

PATIENTS AND METHODS

According to the random and double-blind method, the patients with non-traumatic femoral head necrosis diagnosed and treated in our hospital from July 2019 to January 2022 were selected as the subjects (the research group). According to the staging of the International Society of Bone Circulation for Femoral Head Necrosis, 89 patients with stage Ⅱ and Ⅲ A were included (39 patients with stage Ⅱ and 50 patients with stage Ⅲ A). 25 patients who conducted physical examination in our hospital during the same time were taken as the control group. Quantitative parameters of CEUS were analyzed. The content of serum vascular endothelial growth factor (VEGF) and bone morphogenetic protein-2 (BMP-2) were evaluated. The relationship among the quantitative parameters of CEUS, the expression of VEGF and BMP-2 in serum and the patient's condition, and the value for assisting the early diagnosis of nontraumatic femoral head necrosis were analyzed.

RESULTS

The body mass, body mass index (BMI), blood lipid, and cholesterol levels were much higher in the research group than in the control group (p < 0.05). The research group had a markedly higher slope of ascending branch (AS), strength enhancement index (EI), and VEGF and obviously lower decay slope (DS), mean transit time (MTT), and time to peak (TTP) than the control group (p < 0.05). In the research group, compared to stage Ⅱ, the levels of AS, EI, and VEGF in stage Ⅲ A patients were memorably higher, and the levels of DS, MTT, TTP and BMP-2 were dramatically lower (p < 0.05). Pearson's correlation test showed that AS, EI, and VEGF were positively correlated with the patients' condition, while DS, MTT, TTP and BMP-2 were negatively correlated with the patients' condition (p < 0.05). The receiver operating characteristic (ROC) curve analysis showed that the diagnostic area under the curve (AUC) of quantitative parameters of CEUS was 0.961, with sensitivity and specificity of 88.0% and 97.4%, respectively. The AUC of the combined detection of VEGF and BMP-2 was 0.945 with sensitivity and specificity of 82.3% and 87.5%, respectively, and the combined detection had a high diagnostic value (p < 0.05).

CONCLUSIONS

The quantitative parameters of CEUS were of great value in the early diagnosis of nontraumatic necrosis of the femoral head with microvascular perfusion and the patients' condition, and provided a reference for the clinical treatment of non-traumatic necrosis of the femoral head. These parameters were expected to be useful indicators for judging the efficacy before and after treatment.

Prediction of plan adaptation in head and neck cancer proton therapy using clinical, radiographic, and dosimetric features

PURPOSE

Because proton head and neck (HN) treatments are sensitive to anatomical changes, plan adaptation (re-plan) during the treatment course is needed for a significant portion of patients. We aim to predict re-plan at plan review stage for HN proton therapy with a neural network (NN) model trained with patients' dosimetric and clinical features. The model can serve as a valuable tool for planners to assess the probability of needing to revise the current plan.

METHODS AND MATERIALS

Mean beam dose heterogeneity index (BHI), defined as the ratio of the maximum beam dose to the prescription dose, plan robustness features (clinical target volume (CTV), V100 changes, and V100 > 95% passing rates in 21 robust evaluation scenarios), as well as clinical features (e.g., age, tumor site, and surgery/chemotherapy status) were gathered from 171 patients treated at our proton center in 2020, with a median age of 64 and stages from I-IVc across 13 HN sites. Statistical analyses of dosimetric parameters and clinical features were conducted between re-plan and no-replan groups. A NN was trained and tested using these features. Receiver operating characteristic (ROC) analysis was conducted to evaluate the performance of the prediction model. A sensitivity analysis was done to determine feature importance.

RESULTS

Mean BHI in the re-plan group was significantly higher than the no-replan group (p < .01). Tumor site (p < .01), chemotherapy status (p < .01), and surgery status (p < .01) were significantly correlated to re-plan. The model had sensitivities/specificities of 75.0%/77.4%, respectively, and an area under the ROC curve of .855.

CONCLUSION

There are several dosimetric and clinical features that correlate to re-plans, and NNs trained with these features can be used to predict HN re-plans, which can be used to reduce re-plan rate by improving plan quality.

[The status and influencing factors of presenteeism among clinical nurses: a systematic review]

Objective: To systematically review the status and factors influencing presenteeism among clinical nurses. Methods: In December 2021, CNKI, CBM, Wanfang, VIP, Web of Science, PubMed, Embase, The Cochrane Library, CINAHL, PsyclNFO and other databases were electronically searched to cross sectional studies on the current situation and factors influencing the occurrence of presenteeism among clinical nurses. The search terms mainly included presenteeism, sick at work, Stanford Presenteeism Scale, nurse, level, risk factor, influence, et al. And the search time was from the establishment of the database to November 30, 2021. Literature screening, data extraction and evaluation of the risk of bias in the included literature were done independently by two researchers, and meta-analysis was performed using Stata 15.1 software. Results: A total of 29 studies involving 13 535 clinical nurses were included.The results of the meta-analysis showed that the score of presenteeism was 17.99 [95% CI (17.02-18.95), P =0.000]. Subgroup analysis showed that presenteeism scores were higher in articles published before 2020 (ES=19.28, 95%CI: 18.41-20.15, P=0.000) and in the group of nurses aged 36 to 40 years (ES=19.27, 95%CI: 17.35~21.19, P=0.000), female (ES= 17.04, 95%CI: 14.70-19.39, P=0.000), secondary school education (ES=21.01, 95%CI: 17.76-24.26, P= 0.007), married (ES=17.49, 95%CI: 15.13-19.85, P=0.000), working for 5 to 10 years (ES=17.78, 95%CI: 16.54-19.02, P=0.000), contract (ES=17.05, 95%CI: 15.23-18.87, P=0.000), working in pediatrics (ES= 16.65, 95% CI: 15.31-17.99, P=0.000) and European region (ES =21.21, 95% CI: 20.50-21.93, P=0.000) . Conclusion: Current evidence suggests that clinical nurses are at high risk of presenteeism, which is affected by variety of factors. The managers should pay attention to the physical and mental health of nurses, identify high-risk factors as early as possible and take measures to reduce the occurrence of presenteeism and improve the quality of nursing.

A180 PLACEBO RATES IN MICROSCOPIC COLITIS RANDOMIZED TRIALS: APPLICATIONS FOR FUTURE DRUG DEVELOPMENT USING A HISTORICAL CONTROL ARM

Background

There remains a need to develop effective medical therapies for patients with microscopic colitis (MC) who do not respond, are intolerant, or relapse on budesonide. Conducting randomized trials in MC is logistically and ethically challenging: budesonide is highly effective, and therefore, some institutional review boards have not allowed trials that randomize MC patients to placebo. However, comparing an investigational drug to budesonide is statistically infeasible: powering a non-inferiority study against a budesonide comparator arm with 90% power for a 10% non-inferiority margin would require over 700 subjects, yet fewer than 400 patients have been randomized in all historical MC trials. Therefore, alternative trial designs should be explored in MC, including the use of a historical control arm.

Purpose

To conduct a systematic review and meta-analysis to determine the proportion of placebo responders in MC trials that will inform future trials using a historical placebo comparator, and evaluate factors associated with placebo response.

Method

EMBASE, MEDLINE, and CENTRAL were searched from inception to January 7, 2022, and supplemented with conference abstracts to identify randomized controlled trials (RCTs) using a placebo comparator in adult patients with confirmed MC (either lymphocytic, collagenous, or mixed populations but excluding incomplete MC). The proportion of clinical and histologic responders in the placebo arms were pooled using random-effect models, statistical heterogeneity was evaluated using the I2 method, and the Freeman-Tukey double arcsine transformation was used to compute 95% confidence intervals (CI) using the score statistic and exact binomial method. All analyses were conducted in Stata 17.0.

Result(s)

Twelve placebo controlled RCTs were included, evaluating a total of 391 patients (163 randomized to placebo). The pooled placebo clinical response rate was 24.4% [95% CI 12.4%, 38.4%] (Figure 1), with substantial heterogeneity (I2=60.8%, p<0.01). The pooled histologic response rate was 19.9% [95% CI: 5.3%, 39.0%], with substantial heterogeneity (I2=66.4%, p<0.01). Subgroup analysis demonstrated higher placebo responses in lymphocytic colitis (39.9% [95% CI: 23.9%, 56.7%]) compared to collagenous colitis (19.8% [95% CI: 5.9%, 37.8%]), but not by allowance of baseline anti-diarrheals. Leave-one-out meta-analysis showed a reduction in heterogeneity after removal of Miehlke et al. 2014 (placebo response 21.0% [95% CI: 11.5%, 32.1%], I2=28.6%, p=0.17).

Image

Conclusion(s)

Approximately 1 in 4 patients in MC trials will respond clinically to placebo and 1 in 5 will demonstrate a histologic response, although with substantial heterogeneity. T his highlights the need for standardized outcome definitions in MC trials and can serve to inform a Bayesian prior estimate for future trials that may consider using a historical placebo comparator.

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None

Disclosure of Interest

P. Hamilton: None Declared, K. Buhler: None Declared, G. Kaplan Grant / Research support from: Ferring, Janssen, AbbVie, GlaxoSmith Kline, Merck, and Shire, Consultant of: AbbVie, Janssen, Pfizer, Amgen, Takeda, and Gilead, C. Lu Consultant of: Abbvie, Janssen, Ferring, and Takeda, Speakers bureau of: Janssen and Abbvie, C. Seow Consultant of: Advisory Boards: Janssen, Abbvie, Takeda, Ferring, Shire, Pfizer, Sandoz, Pharmascience, Fresenius Kabi, Amgen, Speakers bureau of: Janssen, Abbvie, Takeda, Ferring, Shire, Pfizer, Pharmascience, K. Novak Grant / Research support from: AbbVie and Janssen, Consultant of: Advisory board fees from AbbVie, Janssen, Pfizer, Ferring, and Takeda, speaker’s fees from AbbVie, Janssen, and Pfizer, R. Panaccione Consultant of: Abbott, AbbVie, Alimentiv (formerly Robarts), Amgen, Arena Pharmaceuticals, AstraZeneca, Biogen, Boehringer Ingelheim, Bristol-Myers Squibb, Celgene, Celltrion, Cosmos Pharmaceuticals, Eisai, Elan, Eli Lilly, Ferring, Galapagos, Fresenius Kabi, Genentech, Gilead Sciences, Glaxo-Smith Kline, JAMP Bio, Janssen, Merck, Mylan, Novartis, Oppilan Pharma, Organon, Pandion Pharma, Pendopharm, Pfizer, Progenity, Protagonist Therapeutics, Roche, Sandoz, Satisfai Health, Shire, Sublimity Therapeutics, Takeda Pharmaceuticals, Theravance Biopharma, Trellus, Viatris, UCB. Advisory Boards for: AbbVie, Alimentiv (formerly Robarts), Amgen, Arena Pharmaceuticals, AstraZeneca, Biogen, Boehringer Ingelheim, Bristol-Myers Squibb, Celgene, Eli Lilly, Ferring, Fresenius Kabi, Genentech, Gilead Sciences, Glaxo-Smith Kline, JAMP Bio, Janssen, Merck, Mylan, Novartis, Oppilan Pharma, Organon, Pandion Pharma, Pfizer, Progenity, Protagonist Therapeutics, Roche, SandozShire, Sublimity Therapeutics, Takeda Pharmaceuticals, Speakers bureau of: AbbVie, Amgen, Arena Pharmaceuticals, Bristol-Myers Squibb, Celgene, Eli Lilly, Ferring, Fresenius Kabi, Gilead Sciences, Janssen, Merck, Organon, Pfizer, Roche, Sandoz, Shire, Takeda Pharmaceuticals, C. Ma Grant / Research support from: Ferring, Pfizer, Consultant of: AbbVie, Alimentiv, American College of Gastroenterology, Amgen, AVIR Pharma Inc, BioJAMP, Bristol Myers Squibb, Celltrion, Ferring, Fresenius Kabi, Janssen, McKesson, Mylan, Sanofi/Regeneron, Takeda, Pendopharm, Pfizer, Roche, Speakers bureau of: : AbbVie, Amgen, AVIR Pharma Inc, Alimentiv, Bristol Myers Squibb, Ferring, Fresenius Kabi, Janssen, Takeda, Pendopharm, and Pfizer

A192 EFFICACY OF USTEKINUMAB IN SMALL BOWEL STRICTURES OF FIBROSTENOTIC CROHN'S DISEASE AS ASSESSED BY INTESTINAL ULTRASOUND

Background

Small bowel Crohn’s disease (CD) strictures can lead to debilitating obstructive symptoms and the deterioration of quality of life. Imaging modalities such as intestinal ultrasound (IUS) are invaluable in the diagnosis of strictures. The use of IUS in CD is rapidly growing, is cost-effective, easily repeatable, and similar in accuracy to magnetic resonance enterography. Evidence for medical management of fibrostenotic CD has been limited to anti-tumor necrosis factor biologics. Studies on the efficacy of other biologic therapies for strictures such as ustekinumab, a p40/interleukin 12 and 23 inhibitor, are lacking.

Purpose

The objective of this study was to evaluate the efficacy of ustekinumab in the treatment of small bowel strictures on IUS.

Method

This retrospective cohort study evaluated the IUS changes of terminal ileal (TI) CD strictures at baseline and 12 months following ustekinumab initiation from 2016 to 2020 at a single tertiary care center. Strictures identified were defined as 1) increased bowel wall thickness (BWT) > 3mm, 2) narrowed luminal apposition, and 3) presence of pre-stenotic dilation (PSD) or the inability to pass the colonoscope through the narrowed area. Changes in sonographic parameters (BWT, luminal size, PSD, length, hyperemia, inflammatory fat, dysfunctional peristalsis) were recorded at baseline prior to initiation of ustekinumab and compared 12 months after treatment. Differences from baseline to 12 months were paired within-person and statistical analysis was performed using paired T-tests for continuous variables and McNemar’s test for categorical variables.

Result(s)

Of the 18 patients identified, 55% (n = 10) were male, median age was 49 years (Q1-Q3: 33-63 years) at initial scan, with median CD duration of 10 years (Q1-Q3: 8-20 years). The majority of TI strictures were surgically naïve (67%, n = 12). Between pre- and 12-month post ustekinumab therapy scans, there was significant improvement in BWT [8.2 mm vs 7.2 mm, p = 0.048], however there was no significant difference in the presence of peri-enteric inflammatory fat (p = 0.10), mean stricture length (17.7 vs 21.7 cm, p = 0.18), and mean stricture lumen diameter (3.3 mm vs 2.7 mm, p = 0.44) (Table 1). There was also no significant difference in the presence of stricture-associated peri-enteric fat (89% vs 67%, p = 0.10), stricture-associated hyperemia (83% vs 89%, p = 0.65) or dysfunctional peristalsis (50% vs 61%, p = 0.41) (Table 1).

Image

Conclusion(s)

Our study is the first to report the efficacy of ustekinumab in small bowel CD strictures using IUS at baseline and 12 months. This study shows that although ustekinumab leads to improvement in overall sonographic appearance of bowel thickness, it does not improve luminal narrowing nor PSD, two hallmark criteria of fibrostenosis. More extensive studies with larger sample sizes evaluating ustekinumab, or combination therapies, are required to identify their role in stricturing CD.

Please acknowledge all funding agencies by checking the applicable boxes below

None

Disclosure of Interest

None Declared

Risk factors analysis and establishment of predictive nomogram of extranodal B-cell lymphoma of mucosal-associated lymphoid tissue

PURPOSE

The role of radiation therapy in mucosa-associated lymphoid tissue (MALT) lymphoma is poorly defined. The objective of this study was to explore the factors associated with the performance of radiotherapy and to assess its prognostic impact in patients with MALT lymphoma.

PATIENTS AND METHODS

Patients with MALT lymphoma diagnosed between 1992 and 2017 were identified in the US Surveillance, Epidemiology, and End Results database (SEER). Factors associated with the delivery of radiotherapy were assessed by chi-square test. Overall survival (OS) and lymphoma-specific survival (LSS) were compared between patients with and without radiotherapy, using Cox proportional hazard regression models, in patients with early stage as well as those with advanced stage.

RESULTS

Of the 10,344 patients identified with a diagnosis of MALT lymphoma, 33.6% had received radiotherapy; this rate was 38.9% for stage I/II patients and 12.0% for stage III/IV patients, respectively. Older patients and those who already received primary surgery or chemotherapy had a significantly lower rate of receiving radiotherapy, regardless of lymphoma stage. After univariate and multivariate analysis, radiotherapy was associated with improved OS and LSS in patients with stage I/II (HR=0.71 [0.65-0.78]) and (HR=0.66 [0.59-0.74]), respectively, but not in patients with stage III/IV (HR=1.01 [0.80-1.26]) and (HR=0.93 [0.67-1.29]). The nomogram built from the significant prognostic factors associated with overall survival of stage I/II patients had a good concordance (C-index=0.749±0.002).

CONCLUSION

This cohort study shows that radiotherapy is significantly associated with a better prognosis in patients with early but not advanced MALT lymphoma. Prospective studies are needed to confirm the prognostic impact of radiotherapy in patients with MALT lymphoma.

A170 ADVERSE EVENTS & SEROLOGICAL RESPONSES FOLLOWING SARS-COV-2 VACCINATION IN INDIVIDUALS WITH INFLAMMATORY BOWEL DISEASE

Background

The rapid development and distribution of SARS-CoV-2 vaccines has raised concerns surrounding vaccine safety in immunocompromised populations, such as those with inflammatory bowel disease (IBD).

Purpose

We described adverse events (AEs) following SARS-CoV-2 vaccination in those with IBD and determined relationships between AEs to post-vaccination antibody titres.

Method

Individuals with IBD from a prospective cohort in Calgary, Canada (n=670) who received a 1^st, 2^nd, 3^rd, and/or 4^th dose of a SARS-CoV-2 vaccine (Pfizer-BioNTech, Moderna, and/or AstraZeneca) were interviewed via telephone for AEs using the Adverse Events Following Immunization form. Subsequently, we assessed injection site reaction as a specific AE outcome. Multivariable logistic regression models were used to assess the association between anti-SARS-CoV-2 spike protein antibody (anti-S) levels within 1–12 weeks of vaccination and injection site reaction following 1st, 2nd, and 3rd dose vaccination. Models were adjusted for age, sex, IBD type, IBD medications, vaccine type, and prior COVID-19 infection. Additionally, we evaluated the risk of flare of IBD within 30 days of vaccination via chart review.

Result(s)

Table 1 describes AEs in individuals with IBD following 1^st dose (n=331), 2^nd dose (n=331), 3^rd dose (n=195), and 4^th dose (n=100) of a SARS-CoV-2 vaccine. AEs were reported in 83.3% of participants after 1^st dose, 79.1% after 2^nd dose, 77.4% after 3^rd dose, and 67.0% after 4^th dose. Injection site reaction (pain, redness, etc.) was the most common AE (50.8% of AEs), with fatigue and malaise (18.1%), headache and migraine (8.6%), musculoskeletal discomfort (8.2%), and fever and chills (6.5%) also commonly reported. Multivariable logistic regression determined no associations between anti-S concentration and injection site reaction for all doses. Age above 65 years was associated with decreased injection site reaction following 1^st and 3^rd doses, while female sex and mRNA vaccine type were associated with increased injection site reaction following 1^st and 2^nd doses. Prior COVID-19 infection, IBD type, and medication class were not associated with injection site reaction with any dose. Only one participant was diagnosed with a severe AE requiring hospitalization: Immune thrombocytopenic purpura (ITP) following 2^nd dose of a Pfizer vaccination. No cases of IBD flare occurred within 30 days of vaccination.

Image

Conclusion(s)

AEs following SARS-CoV-2 vaccination are generally mild and become less common with each consecutive dose. Antibody levels following each dose of the vaccine were not associated with injection site reactions. Females, those under 65 years of age, and those administered mRNA vaccines were more likely to experience an injection site reaction. Prior COVID-19 infection, IBD type, and IBD medication class did not predict injection site reactions. Vaccination was not associated with IBD flare within 30 days of vaccination.

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Other

Please indicate your source of funding;

Helmsley

Disclosure of Interest

A. Markovinovic: None Declared, M. Herauf: None Declared, J. Quan: None Declared, L. Hracs: None Declared, J. Windsor: None Declared, N. Sharifi: None Declared, S. Coward: None Declared, L. Caplan: None Declared, J. Gorospe: None Declared, C. Ma Grant / Research support from: Ferring, Pfizer, , Consultant of: AbbVie, Alimentiv, Amgen, Ferring, Pfizer, Takeda, , Speakers bureau of: AbbVie, Alimentiv, Amgen, Ferring, Pfizer, Takeda, R. Panaccione Grant / Research support from: AbbVie, Ferring, Janssen, Pfizer, Takeda, Consultant of: Abbott, AbbVie, Alimentiv, Amgen, Arena, AstraZeneca, Boehringer Ingelheim, Bristol Myers Squibb, Celgene, Celltrion, Cosmos Pharmaceuticals, Eisai, Elan, Eli Lilly, Ferring, Galapagos, Genentech, Gilead Sciences, GlaxoSmithKline, Janssen, Merck, Mylan, Oppilan Pharma, Pandion Therapeutics, Pandion Pharma, Pfizer, Progenity, Protagonist, Roche, Sandoz, Satisfai Health, Schering-Plough, Shire, Sublimity Therapeutics, Takeda, Theravance, UCB, Speakers bureau of: AbbVie, Arena, Celgene, Eli Lilly, Ferring, Gilead Sciences, Janssen, Merck, Pfizer, Roche, Sandoz, Shire, Takeda, R. Ingram: None Declared, J. Kanji: None Declared, G. Tipples: None Declared, J. Holodinsky: None Declared, C. Berstein Grant / Research support from: AbbVie, Amgen, Janssen, Pfizer, Takeda, Speakers bureau of: AbbVie, Janssen, Pfizer, Takeda, D. Mahoney: None Declared, S. Bernatsky: None Declared, E. Benchimol: None Declared, G. Kaplan Grant / Research support from: Ferring, Speakers bureau of: AbbVie, Janssen, Pfizer

A107 VISCERAL ADIPOSE TISSUE VOLUME DIFFERENTIATES BETWEEN FIBROSTENOTIC AND INFLAMMATORY CROHN’S DISEASE

Background

Creeping fat, a form of visceral adipose tissue (VAT) that wraps the intestinal wall, influences the formation of Crohn’s disease (CD) strictures. The degree of fat wrapping from intestinal stricture resections is correlated with the extent of chronic inflammation, fibrosis, stricture formation, and response to biologic therapy. VAT and subcutaneous adipose tissue (SAT) ratios from CTE (computed tomography) scans are elevated in CD strictures. However, the definition of strictures in these studies has been poorly defined and not included current well-recognized criteria: 1) bowel wall thickness (BWT), 2) narrowed luminal diameter, and 3) pre-stenotic dilation. (PSD).

Purpose

The objective of this pilot study was to assess the relationship of 2D and 3D VAT:SAT ratios with CT stricture parameters in patients with terminal ileal (TI) CD strictures.

Method

2D VAT:SAT ratios from CT’s of CD patients with TI strictures defined as increased BWT, narrowed luminal diameter (< 50% relative to normal adjacent distended loop), and PSD greater than the stricture diameter were retrospectively obtained from a database and chart review. CT’s from fibrostenotic CD patients were sex and BMI matched to patients with only TI inflammatory behaviour. Patient demographics, medication, smoking, and surgical history were also obtained. Analyses were adjusted for age, sex, and BMI covariates. Unpaired t-tests and multi-variable logistic regression analyses were conducted.

Result(s)

Twenty-eight patients with stricturing CD had a significantly greater mean VAT:SAT volume ratio than 29 non-stricturing CD (41.5 cm³ vs 34.2 cm³, p=0.03). Thirty-six percent (10/28) of CD stricture patients had prior ileocolic resection with a mean disease duration of 13.5 years (range 0-48). The median ileal BWT (7.0 mm, range 4.0-13.0 mm) for the stricturing group was significantly greater than those with inflammatory behaviour (BWT 2.0 mm, p<0.0001). The median luminal diameter and PSD for the stricture group was 2.0 mm (range 0 - 14.0 mm), and 3.0 cm (range 1.0 - 7.3 cm), respectively.

Image

Conclusion(s)

Fibrostenotic TI CD patients have increased VAT:SAT ratios in comparison to those with only inflammatory behaviour. These pilot VAT:SAT results provide an initial foundation for further studies to assess its predictive role in responsiveness of medical or surgical therapies in stricturing CD.

Please acknowledge all funding agencies by checking the applicable boxes below

None

Disclosure of Interest

None Declared

A193 DEMOGRAPHIC, SOCIAL AND OCCUPATIONAL FACTORS THAT PREVENTED EXPOSURE TO SARS-COV-2 IN INFLAMMATORY BOWEL DISEASE PATIENTS DURING THE COVID-19 PANDEMIC: A PROSPECTIVE COHORT STUDY

Background

The COVID-19 pandemic caused by the SARS-CoV-2 virus is a rapidly evolving public health emergency in which mundane behaviors such as grocery shopping or restaurant dining are considered high-risk for some, such as persons with inflammatory bowel disease (IBD) who are often immunodeficient due to medications. Research on the behavioral exposures experienced by populations with IBD during the COVID-19 pandemic are lacking.

Purpose

We aim to better understand how the behaviors of persons with IBD are associated with COVID-19 diagnoses.

Method

We conducted a prospective serosurveillance cohort study in Calgary to assess exposure to SARS-CoV-2 from Nov. 1, 2020 to Aug. 8, 2022 in 485 individuals with IBD. A diagnosis of SARS-CoV-2 was defined as a molecular-confirmed PCR test, a self-report home antigen test, or a positive nucleocapsid antibody level. Participants completed a self-report electronic questionnaire on social and occupational risk activities stratified across two time periods: Jan. 2020 to Mar. 2020 (before lockdown) and post-Jun. 2020 (post lockdown). Univariate analyses (χ² and Fischer’s exact if n≤5) were performed on social activities that occurred following the lockdown among those with IBD who were and were not diagnosed with COVID-19. Occupational exposures were compared across essential workers (EW) (i.e., frontline workers at high risk of COVID) and non-EWs.

Result(s)

Overall, 37.5% (n=182) of our cohort was diagnosed with COVID-19. Seniors were less likely to be infected with COVID-19 (22.7%) compared to those under the age of 65 (40.8%) (p=0.002). A greater proportion of females (42.6 %) compared to males (32.5%) were COVID positive (p=0.02). Those with Crohn’s disease (38.3%) were as likely to test positive for COVID-19 as those with ulcerative colitis (36%) (p=0.65). COVID positive patients were less likely to have 4 vaccine doses (28.5%) compared to those who tested negative (71.5%) (p=0.4).

Statistically significant decreases (p<0.001) in engagement post-Jun. 2020 were observed for: bar use (11.6% to 2.1%), visiting a friend (44.5% to 15.2%), having visitors over (38.7% to 12.1%), restaurant dining (38% to 9%), indoor fitness (31.9% to 8.4%), and transit use (11% to 1.3%). There was an increase in regular use of outdoor fitness (31.9% to 67.1%, p<0.003).

Persons with IBD who tested positive for COVID-19 were more likely to regularly dine in a restaurant (16.8% vs. 4.7% for COVID negative, p<0.001), engage in indoor fitness activities (14% vs. 5.1%, p<0.001), and travel outside Calgary (21% vs. 11.2%, p=0.004) post-lockdown.

Post-lockdown, a greater proportion of EW were COVID positive (50.4%) compared to non-EW (38.6%) (p=0.04).

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Conclusion(s)

Over a two-year period, two-thirds of our cohort did not test positive for COVID-19. Those with IBD who avoided COVID tended to be older, male, have 4 doses of vaccine, and reduce their risk of exposure through social and occupational modifications, perhaps in response to public health guidance.

Disclosure of Interest

None Declared

A15 GENETIC OR DIET-ASSOCIATED DEFECTS IN MUCUS FACILITATE ULCERATIVE COLITIS PATHOBIONT-DRIVEN COLITIS

Background

The Inflammatory Bowel Diseases (IBD), Crohn’s Disease (CD) and ulcerative colitis (UC) affect > 270,000 Canadians and are increasing in incidence. Ileal CD has been linked to the overgrowth of mucosal adherent E. coli. Recent studies have also implicated the adherence of Escherichia coli pathobionts to the colonic mucosa of UC patients. Using the representative UC E. coli pathobiont p19A, we recently demonstrated it aggravated chemical-induced colitis in susceptible mice, through the actions of the toxin alpha-hemolysin, and by adhering to the inflamed colonic mucosa via the adhesin FimH. It is less clear what host factors control susceptibility to the UC pathobionts. One of the potential candidates is the glycosylated mucin (Muc2) which forms the mucus layer that covers the colonic epithelium and is often impaired in UC patients.

Purpose

To define the role of mucus structure and function in determining susceptibility to the p19A pathobiont, and its ability to cause colitis in mice.

Method

In vitro growth was assessed to test p19A’s ability to utilize mucin-derived sugars as nutrients. Susceptibility to p19A was tested in two mouse models of colonic mucus impairment. The first is a mouse strain deficient in core 1 derived O-glycans in their intestinal epithelial cells (IEC C1galt1^-/-), resulting in reduced Muc2 glycosylation, and thus a thin and impaired mucus barrier. The second model involves feeding wildtype (WT) C57BL/6CR mice a fiber-free (FF) diet, resulting in a significantly thinner colonic mucus layer. The mice were subsequently orally gavaged with p19A and their susceptibility determined by p19A burdens, intestinal histopathology, inflammatory cytokine and short chain fatty acid (SCFA) production.

Result(s)

When tested in vitro, the p19A pathobiont was found to use an array of mucin-derived sugars as sole carbon source to proliferate. Following oral gavage of WT mice fed a normal diet, immunostaining identified p19A within the colonic mucus but it did not reach the colonic mucosa or cause disease. In contrast, p19A was found at the colonic mucosal surface of mucus-defective IEC C1galt1^-/- mice (as compared to IEC C1galt1^flox/flox mice) and in WT mice fed a fiber-free diet. This mucosal adherence was associated with increased body weight loss during the course of infection, as well as increased p19A burdens, colonic pathology and pro-inflammatory cytokine expression. Especially fiber-free diet-fed mice showed reduced SCFA levels in their feces at baseline. When the mice were given exogenous SCFA (tributyrin) orally, p19A infection was reduced.

Conclusion(s)

Our results indicate that UC E. coli pathobionts are able to dwell within colonic mucus and utilize mucin sugars as nutrients. Moreover, they can reach the mucosal surface and induce colitis in hosts suffering genetic or diet-based mucus dysfunction. In part, this susceptibility reflects the important role played by mucus in the production of SCFA, suggesting potential therapeutic approaches for patients suffering UC.

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CCC, CIHR

Disclosure of Interest

None Declared

A142 APPROPRIATENESS OF POST-ENDOSCOPY CARE IN PATIENTS PRESENTING WITH FOOD BOLUS IMPACTIONS OVERNIGHT: A POPULATION-BASED MULTICENTER COHORT STUDY

Background

Appropriate management of esophageal food bolus impactions includes endoscopic evaluation and follow-up for potential underlying esophageal pathology. Patients who present with impactions at night may not receive optimal long-term post-endoscopy care due to patient-, physician-, or system-related factors.

Purpose

We aimed to evaluate the appropriateness of care for patients who present with food bolus impactions after regular daytime hours.

Method

We conducted a retrospective, population-based, multi-center cohort study of adult patients undergoing endoscopy for food impaction between 19:00-06:59 from 2016-2018 in the Calgary Health Zone, Canada. Appropriate post-endoscopy care was defined by a composite of a follow-up clinic visit, repeat endoscopy, other appropriate investigations (e.g., manometry), or appropriate medical treatment (e.g., proton pump inhibitor). Predictors of inappropriate care were assessed using multivariable logistic regression, expressed as adjusted odds ratios (aOR) with 95% confidence intervals (CI).

Result(s)

A total of 323 patients underwent an after-hours or overnight endoscopy for food bolus impaction. 25.4% (82/323) of patients did not receive appropriate post-endoscopy care. Predictors of inappropriate care included rural residence (aOR 2.66 [95% CI: 1.18-6.01], p=0.02), first food bolus presentation (aOR 2.38 [95% CI: 1.04-5.44], p=0.04), and absence of a specific pathology during the index procedure (aOR 3.01 [95% CI: 0.97-9.29], p=0.05), suggesting a potential association with clinician cognitive bias. Among patients who were followed, 18.9% (35/185) had a change in the original diagnosis.

Image

Conclusion(s)

One quarter of patients presenting with a food bolus impaction at night do not receive appropriate post-endoscopy care. System-based interventions should target this high-risk population as the diagnosis and management may change with follow-up.

Please acknowledge all funding agencies by checking the applicable boxes below

None

Disclosure of Interest

None Declared

A195 DURABILITY OF SEROLOGICAL RESPONSES AFTER SECOND, THIRD AND FOURTH DOSE OF SARS-COV-2 VACCINATION IN INFLAMMATORY BOWEL DISEASE: A PROSPECTIVE COHORT STUDY

Background

Adequate serological responses following two-dose regimens and additional doses of SARS-CoV-2 vaccination have been demonstrated for the vast majority of those with IBD. However, antibody levels following 2^nd, 3^rd, and 4^th dose SARS-CoV-2 vaccination may decrease over time in the IBD population.

Purpose

We assessed the durability of serological responses to 2^nd, 3^rd, and 4^th dose SARS-CoV-2 vaccination over time in a cohort of IBD patients.

Method

Adults with IBD who received at least one dose of a SARS-CoV-2 vaccine (n=559) were evaluated for serological response to the spike protein of SARS-CoV-2 using the Abbott IgG II Quant assay with a seroconversion threshold of ≥ 50 AU/mL. The geometric mean titer (GMT) with 95% confidence intervals (CI) were calculated and stratified by weeks (1–8, 8–16, 16–24, 24+ weeks) after each vaccine dose. We compared stratified GMTs with Mann–Whitney U tests using a significance level of 0.05.

Result(s)

Our cohort (n=559) comprised the following patient characteristics: 82.8% were 18–65 years-old (n = 463), 53.1% were female (n =297), and 71.6% had Crohn’s disease (n =400). IBD medications were classified in the following mutually exclusive groups: No immunosuppressives 10.5% (n = 59), anti-TNF monotherapy 35.8% (n = 200), immunomodulatory monotherapy 2.1% (n =12 ), vedolizumab 11.8% (n =66 ), ustekinumab 20.4% (n =114 ), tofacitinib 1.2% (n =7 ), combination therapy 15.9% (n = 89), and prednisone 2.1% (n =12). For vaccine type, 85.6% and 82.3% had Pfizer for 3^rd and 4^th dose, respectively, while the remainder had Moderna. Seroconversion rates 1–8 weeks after 3^rd and 4^th dose were both 99.9%.

Figure 1 compares GMTs with 95% CI by weeks after each vaccine dose. GMTs are highest 1–8 weeks after 2^nd dose (4053 AU/mL; 95% CI: 3468, 4737 AU/mL; n=337), 3^rd dose (12116 AU/mL; 10413, 14098 AU/mL; n=256), and 4^th dose (14337 AU/mL; 10429, 19710 AU/mL; n=67). Subsequently, antibody levels decay from 1–8 weeks to 8–16 weeks (p<0.001) for 2^nd dose (mean difference: –2224 AU/mL), 3^rd dose (mean difference: –7526 AU/mL), and 4^th dose (mean difference: –9715 AU/mL). Compared to 16–24 weeks after 2^nd dose, antibody levels 24+ weeks after were similar (GMTs: 795 AU/mL vs. 1043 AU/mL, p=0.52). For third dose, antibody levels 8–16 weeks and 16–24 weeks after vaccination were similar (4590 AU/mL vs. 4073 AU/mL, p=0.73) along with 16–24 weeks compared to 24+ weeks after vaccination (4073 AU/mL vs. 5876 AU/mL, p=0.18).

Image

Conclusion(s)

Within 1–8 weeks after each dose of vaccine, serological responses spikes with each subsequent dose yielding a higher GMT. While antibody levels decay 8–16 weeks after each dose, similar GMT levels beyond 16 weeks may indicate durability of antibody levels over a longer duration of time.

Disclosure of Interest

None Declared

Clinical comparison of superior thyroid artery perforator flap and sternocleidomastoid myocutaneous flap for intraoral reconstruction

The aim was to evaluate the techniques and outcomes of superior thyroid artery perforator flaps (STAPF) for intraoral reconstruction and to compare them with those of the sternocleidomastoid myocutaneous flap (SCMMF). The cases of 43 patients who underwent reconstruction with either a SCMMF or STAPF for the repair of a medium-sized intraoral defect, between January 2013 and December 2020, were reviewed retrospectively. Although both flaps are based on the superior thyroid artery, their specific harvesting techniques largely differ. All SCMMF (n = 23) were superiorly-based rotational flaps with myocutaneous designs. The STAPF cases (n = 20) included 18 septocutaneous flaps and two chimeric flaps. The flap size was larger in the STAPF group (P = 0.008), while incomplete level IIB dissection (oncological safety) was more frequent in the SCMMF group (P = 0.002). The flap necrosis rate was lower in the STAPF group (STAPF 15% vs SCMMF 34.8%, though this was not statistically significant). Cox multivariate analysis showed that the postoperative flap outcome (total flap necrosis vs flap survival; hazard ratio 27, 95% confidence interval 2.149-336.05; P = 0.001) and complications (excluding fistula) (hazard ratio 14, 95% confidence interval 1.314-142.767; P = 0.029) were associated with overall patient survival. Both speech (P < 0.001) and neck mobility (P < 0.001) functions were superior with STAPF reconstruction. Compared with the traditional SCMMF, the STAPF was found to have a lower necrosis rate with uncompromised oncological safety during harvesting. The STAPF is a good alternative for the repair of medium-sized head and neck defects.

Formation and evolution of carbonaceous asteroid Ryugu: Direct evidence from returned samples

Samples of the carbonaceous asteroid Ryugu were brought to Earth by the Hayabusa2 spacecraft. We analyzed 17 Ryugu samples measuring 1 to 8 millimeters. Carbon dioxide-bearing water inclusions are present within a pyrrhotite crystal, indicating that Ryugu's parent asteroid formed in the outer Solar System. The samples contain low abundances of materials that formed at high temperatures, such as chondrules and calcium- and aluminum-rich inclusions. The samples are rich in phyllosilicates and carbonates, which formed through aqueous alteration reactions at low temperature, high pH, and water/rock ratios of <1 (by mass). Less altered fragments contain olivine, pyroxene, amorphous silicates, calcite, and phosphide. Numerical simulations, based on the mineralogical and physical properties of the samples, indicate that Ryugu's parent body formed ~2 million years after the beginning of Solar System formation.

[Directed differentiation of human induced pluripotent stem cells into midbrain]

OBJECTIVE

To establish an efficient protocol for directed differentiation of human induced pluripotent stem cells (hiPSCs) into functional midbrain dopaminergic progenitor cells (DAPs) in vitro.

METHODS

hiPSCs were induced to differentiate into DAPs in two developmental stages. In the first stage (the first 13 days), hiPSCs were induced into intermediate cells morphologically similar to primitive neuroepithelial cells (NECs) in neural induction medium containing a combination of small molecule compounds. In the second stage, the intermediate cells were further induced in neural differentiation medium until day 28 to obtain DAPs. After CM-DiI staining, the induced DAPs were stereotactically transplanted into the right medial forebrain bundle (MFB) of rat models of Parkinson's disease (PD). Eight weeks after transplantation, the motor behaviors of PD rats was evaluated. Immunofluorescence assay of brain sections of the rats was performed at 2 weeks after transplantation to observe the survival, migration and differentiation of the transplanted cells in the host brain microenvironment.

RESULTS

hiPSCs passaged stably on Matrigel showed a normal diploid karyotype, expressed the pluripotency markers OCT4, SOX2, and Nanog, and were positive for alkaline phosphatase. The primitive neuroepithelial cells obtained on day 13 formed dense cell colonies in the form of neural rosettes and expressed the neuroepithelial markers (SOX2, Nestin, and PAX6, 91.3%-92.8%). The DAPs on day 28 highly expressed the specific markers (TH, FOXA2, LMX1A and NURR1, 93.3-96.7%). In rat models of PD, the hiPSCs-DAPs survived and differentiated into TH⁺, FOXA2⁺ and Tuj1⁺ neurons at 2 weeks after transplantation. Eight weeks after transplantation, the motor function of PD rats was significantly improved as shown by water maze test (P < 0.0001) and apomorphine-induced rotation test (P < 0.0001) compared with rats receiving vehicle injection.

CONCLUSION

HiPSCs can be effectively induced to differentiate into DAPs capable of differentiating into functional neurons both in vivo and in vitro. In rat models of PD, the transplanted hiPSCs-DAPs can survive for more than 8 weeks in the MFB and differentiate into multiple functional neurocytes to ameliorate neurological deficits of the rats, suggesting the potential value of hiPSCs-DAPs transplantation for treatment of neurological diseases.

[Consolidate the foundation, steadily promote and comprehensively improve the quality control in prevention and management of venous thromboembolism in China]

Hospital-associated venous thromboembolism (HA-VTE) has become a public health problem that seriously affects the quality of medical care and patient safety. Many countries regarded VTE prevention as a key element of medical quality management, carried out quality improvement work in VTE prevention and achieved remarkable results. In China, there is also unremitting efforts and explorations in the field of VTE prevention and management. The national program for prevention and management of pulmonary embolism and deep vein thrombosis was officially launched. Through a series of measures such as excellent center construction, regional alliance, and strengthening of quality control and informatization, the national program has greatly promoted the construction of VTE prevention and management system in hospitals across the country. Strengthening the prevention and treatment of VTE has become the common will of the government, hospital administrators, clinical medical staff and the public. In the future, we need to continue to steadily promote the prevention and management of VTE, and comprehensively improve the quality control management level of VTE prevention and management in hospitals.

[Quality of life and risk factors in patients with herpes zoster]

Objective: To evaluate the quality of life and influencing factors of patients with herpes zoster (HZ) seen in hospitals. Methods: Based on Zoster Brief Pain Inventory (ZBPI) and Five-level EuroQol Five-dimensional Questionnaire (EQ-5D-5L), a cross-sectional survey was conducted to evaluate the pain severity and quality of life of 332 HZ cases seen in 22 hospitals of Lu'an City (Anhui Province), Zibo City (Shandong Province) and Tongchuan City (Shaanxi Province) from October to December 2021. The censored least absolute deviations (CLAD) model was used to analyze the related factors affecting the changes of patients' health utility values. Results: The 45.5% of 332 HZ cases were male. The median (Q₁,Q₃) age was 59 (50, 68) years. 59.64% of them assessed by ZBPI had moderate to severe pain in the past 24 hours (worst pain score≥5), and that of PHN cases was 84.8%(39/46). 77.7% (258/332), 77.4% (257/332) and 74.1% (246/332) of all patients reported that pain interfered with sleep, mood and general activities, respectively. Aging [β_40-49y (95%CI)=-0.11 (-0.15, -0.08); β_50-59y (95%CI)=-0.03 (-0.05, 0.00); β_60-69y (95%CI)=-0.09 (-0.12, -0.06); β_70-90y(95%CI)=-0.16 (-0.19, -0.12)], working status (unemployed) [β_farmer (95%CI)=0.15 (0.13, 0.18); β_retirees(95%CI)=0.21 (0.18, 0.24); β_employee (95%CI)=0.13 (0.10, 0.16) ], complications[β_PHN (95%CI)=-0.08 (-0.13, -0.04); β_{other complications} (95%CI)=-0.12 (-0.15, -0.08)], within 30 days after onset [β(95%CI)=-0.01 (-0.03, 0.01)] and treatment [β_{other complications} (95%CI)=-0.09 (-0.11, -0.06)] were related factors for the decline of health utility value (all P values <0.05). Conclusions: More than half of the patients with HZ had moderate to severe pain in the past 24 hours, which had a serious negative impact on the physical and mental health of the patients. Elderly patients, acute patients and patients with complications had lower health utility values and worse health status. We suggest that eligible people be vaccinated with HZ vaccine as soon as possible.

[Research progress of mesenchymal stem cell in the treatment of diabetic bladder dysfunction]

Diabetic bladder dysfunction (DBD) is a common complication in the lower urinary tract of diabetes. In recent years, mesenchymal stem cell (MSC) have broad application prospects in the treatment of DBD. MSC can migrate to damaged bladder tissue and differentiate into various cell types, such as urothelial cells, myofibroblasts, smooth muscle cells and nerve cells, promote bladder tissue repair and regeneration through paracrine effects. In addition, MSC also intervene in the pathological process of DBD, reverse disease progression, and restore partial bladder function through immune regulation, improvement of oxidative stress, and regulation of blood glucose. At present, the treatment of DBD with MSC is limited to preclinical animal experiments, clinical research and application should be pursued further.

Quantitative Intracerebral Iodine Extravasation in Risk Stratification for Intracranial Hemorrhage in Patients with Acute Ischemic Stroke

BACKGROUND AND PURPOSE

Intracerebral hemorrhage poses a severe threat to the outcomes in patients with postthrombectomy acute stroke. We aimed to compare the absolute intracerebral iodine concentration and normalized iodine concentration ratio in predicting intracerebral hemorrhage in patients postthrombectomy.

MATERIALS AND METHODS

Patients with acute anterior circulation large-vessel occlusion who underwent mechanical thrombectomy and had successful recanalization were retrospectively included in the study. Dual-energy CT was performed within 1 hour after mechanical thrombectomy. Postprocessing was performed to measure the absolute intracerebral iodine concentration and the normalized iodine concentration ratio. The correlation between the absolute intracerebral iodine concentration and the normalized iodine concentration ratio was analyzed using the Spearman rank correlation coefficient. We compared the area under the receiver operating characteristic curve of the absolute intracerebral iodine concentration and the normalized iodine concentration ratio using the DeLong test.

RESULTS

We included 138 patients with successful recanalization. Of 43 patients who did not have parenchymal contrast staining on postthrombectomy dual-energy CT, 5 (11.6%) developed intracerebral hemorrhage. Among patients (95/138, 68.8%) with parenchymal contrast staining, 37 (38.9%, 37/95) developed intracerebral hemorrhage. The absolute intracerebral iodine concentration was significantly correlated with the normalized iodine concentration ratio (ρ = 0.807; 95% CI, 0.718-0.867; P < .001). The cutoffs of the normalized iodine concentration ratio and absolute intracerebral iodine concentration for identifying patients with intracerebral hemorrhage development were 222.8%, with a sensitivity of 67.6% and specificity of 76.4%, and 2.7 mg I/mL, with a sensitivity of 75.7% and specificity of 65.5%, respectively. No significant difference was found between the areas under the receiver operating characteristic curve for the absolute intracerebral iodine concentration and the normalized iodine concentration ratio (0.753 versus 0.738) (P = .694).

CONCLUSIONS

The hemorrhagic transformation predictive power of the normalized iodine concentration ratio is similar to that of the absolute intracerebral iodine concentration in patients with successful recanalization.

AB1474 LIPIDOMIC PROFILING IDENTIFIES SERUM LIPIDS ASSOCIATED WITH PERSISTENT MULTISITE MUSCULOSKELETAL PAIN

Background

Lipid mediators have been suggested to have a role in pain sensitivity and response; however, longitudinal data on lipid metabolites and persistent multisite musculoskeletal pain (MSMP) are lacking.

Objectives

This study was to identify lipid metabolic markers for persistent MSMP.

Methods

Lipidomic profiling of 807 lipid species was performed on serum samples of 536 participants from a cohort study. MSMP was measured by a questionnaire and defined as painful sites ≥4. Persistent MSMP was defined as having MSMP at every visit. Logistic regression was used with adjustment for potential confounders. The Benjamini Hochberg method was used to control for multiple testing.

Results

A total of 530 samples with 807 lipid metabolites passed quality control. Mean age at baseline was 61.54±6.57 years and 50% were females. One hundred and twelve (21%) of the participants had persistent MSMP. Persistent MSMP was significantly associated with lower levels of monohexosylceramide (HexCer)(d18:1/22:0 and d18:1/24:0), acylcarnitine (AC)(26:0) and lysophosphatidylcholine (LPC)(18:1 [sn1], 18:2 [sn1], 18:2 [sn2], and 15-MHDA[sn1] [104_sn1]) after controlling for multiple testing. After adjustment for age, sex, body mass index, diabetes status, and physical activity, HexCer(d18:1/22:0 and d18:1/24:0) and LPC(18:1 [sn1] and 15-MHDA [sn1] [104_sn1]) were significantly associated with persistent MSMP [Odds Ratio (OR) ranging from 0.24 - 0.32]. Two lipid classes -- HexCer and LPC were negatively associated with persistent MSMP after adjustment for covariates (OR=0.19 and 0.21, respectively).

Conclusion

This study identified four novel lipid signatures of persistent MSMP, suggesting that lipid metabolism is involved in the pathogenesis of persistent pain.

Disclosure of Interests

None declared

[All-inside subtalar arthroscopy through three portals combined with rafting screws technique for the treatment of the calcaneal fractures of Sanders Ⅱ and Ⅲ]

Objective: To investigate the surgical technology and clinical efficacy of using the all-inside subtalar arthroscopy through three portals combined with rafting screws technique for the treatment of the calcaneal fractures of Sanders Ⅱ and Ⅲ. Methods: The clinical data of 33 patients (33 feet) with intra-articular displaced calcaneal fractures treated by modified all-inside arthroscopic from March 2017 to March 2019 at Department of Orthopedics,Xuzhou Central Hospital were retrospectively analyzed.There were 19 male patients,and 14 female patients,aged (32.6±11.3) years(range:20 to 55 years). According to the Sanders classification,there were 12 cases of type Ⅱ and 21 cases of type Ⅲ. The duration from injury to surgery was (101.2±32.1) hours(range:6 to 140 hours).The preoperative visual analogue scale (VAS) was 6.4±2.9 (range: 4 to 8); The preoperative American Orthopaedic Foot & Ankle Society (AOFAS) ankle-hindfoot scale and the SF-36 score was 63.3±11.8 (range:50 to 75) and 94.8±9.1 (range:70 to 105) respectively.All the patients were managed with the all-side subtalar arthroscopy through three portals combined with rafting screws technique.The incision healing,reduction of fracture,and fracture healing were recorded.The VAS,AOFAS ankle-hindfoot scale,and SF-36 score were used to assess the pain and functional outcomes.Repeated-measurement was used to compare the scores before and after surgery. Results: The time of operation was (69.7±10.4) minutes (range:40 to 110 minutes). All patients did not undergo bone grafting.The incision healed in one stage without complications of skin sensory and peroneal tendon injury.All patients were followed up for 24 months.At the last follow-up,all the patients were satisfied with the hindfoot alignment,function,and hindfoot appearance.Postoperative calcaneal imaging indicators (calcaneal length,calcaneal width,calcaneal height,Bohler angle and Gissane angle) were significantly improved compared with those before surgery (P<0.01).There was no statistically significant difference in the imaging indexes of calcaneus at 1 day,1 year and 2 years after surgery,indicating no loss of fracture reduction (all P>0.05).The VAS,AOFAS ankle-hindfoot scale,and SF-36 score were 1.5±0.4 (range: 0 to 2),94.0±6.5 (range:90 to 100),and 119.1±7.2 (range:105 to 130),respectively,which were better than those before surgery (all P>0.05).According to the AOFAS scoring system,27 cases were excellent,4 cases were good, 2 cases were fair,and the excellent and good rate was 94.0%. Conclusion: All-inside subtalar arthroscopy through three portals combined with rafting screws technique for the treatment of the calcaneal fractures of Sanders Ⅱ and Ⅲ provides precise reduction,reliable fixation,satisfactory function and limited complications,which is an alternative method.

A199 UTILIZATION OF MUCUS-DERIVED O-GLYCAN SUGARS BY THE PATHOGEN C. RODENTIUM FACILITATE ITS COLONIZATION OF THE MURINE GUT

Background

The ability of enteric pathogens to colonize and expand within the mammalian gastrointestinal (GI) tract is determined by several factors, including the ability to find and acquire nutrients. The thick mucus layer that lines the inner surface of the large intestine is rich in sugars that can serve as nutrient sources for several members of the microbiota. Whether these sugars can also be used by invading bacterial pathogens to colonize the GI tract is still unclear, in particular for the family of attaching and effacing (A/E) bacterial pathogens, including the human diarrheal pathogens EHEC and EPEC.

Aims

To investigate the ability of the murine A/E pathogen Citrobacter rodentium to use mucin-derived sugars as a nutrient source, and the importance of these sugars in the virulence of C. rodentium during in-vivo infection.

Methods

To identify which sugar(s) are required for C. rodentium to colonize and grow in the murine GI tract, we generated mutants lacking single or multiple genes involved in the uptake and catabolism of mucin-derived O-glycan sugars. This was followed by in-vitro growth assays in minimal media supplemented with mucin sugars to investigate the growth properties of C. rodentium and the generated mutants on mucin sugars.

Results

We determined that C. rodentium was able to use three mucin O-glycan sugars: sialic acid, galactose, and N-acetylglucosamine (GlcNAc) as both carbon and nitrogen sources for in-vitro growth. C. rodentium exhibited the maximal growth rate and density on GlcNAc, followed by sialic acid, and finally galactose. A mutant C. rodentium strain carrying a deletion in the nagA gene was unable to grow on both GlcNAc and sialic acid, confirming that the breakdown pathways for these two sugars merge and are processed by shared suite of enzymes. As for galactose, combined deletions in the genes mglB and galP were required to abolish growth on this sugar. Notably, a mutant strain carrying simultaneous deletions in nagA, mglB, and galP was unable to grow on all three mucin sugars, as well as on purified mucin.

Conclusions

Our results demonstrate that intestinal mucin sugars serve as potential nutrient sources for C. rodentium and that C. rodentium can catabolize three of these sugars. Future work will examine whether these sugar pathways contribute to C. rodentium colonization of the murine GI tract.

Funding Agencies

CCC, CIHRCH.I.L.D. Fdn

A158 COMPARING CORTIMENT® AND PREDNISONE IN ULCERTATIVE COLITIS: A POPULATION-BASED STUDY OF OUTCOMES

Background

In August 2016 Cortiment® was approved for use in ulcerative colitis (UC) patients in Canada, but not approved for reimbursement; the Canadian Agency for Drugs and Technology in Health cited no comparable benefit for its use over other approved UC medications. Real-world data comparing Cortiment® to other UC medications is limited, especially during the COVID-19 pandemic where the use of steroids is counter-indicated for COVID-19-related outcomes.

Aims

To examine the comparative risk of hospitalization, surgery, and infection after initiation of Cortiment® or oral corticosteroids among UC patients using real-world data

Methods

Using population-based data from Alberta Canada, two cohorts were compared: 1. Patients dispensed Cortiment® and an ICD diagnostic code for UC [9: 556.X; 10: K51.X] (August 1, 2016 to October 31, 2019); and, 2. Validated (algorithm) UC patients dispensed a >30 day supply or >500mg in 24 hours of prednisone/prednisolone (April 1, 2016 to October 31, 2019). All hospitalizations, IBD-surgery, or infections (i.e., pneumonia, c.diff, sepsis, tuberculosis) that occurred 6 or 12 months from initial medication dispensing were identified. Cox-proportional hazard models, with Hazard Ratios (HR), assessed comparative outcomes. Kaplan-Meier survival curves were created, and Poisson regression (or negative binomial) used to assess the Average Monthly Percentage Change (AMPC) with associated 95% confidence intervals (CI).

Results

We identified 917 Cortiment® and 2,404 Prednisone patients. Over the study period, prednisone dispensing significantly decreased (AMPC:-2.53% [CI:-2.85,-2.21]) while Cortiment® remained stable. Dispensing of Cortiment® significantly decreased the hazard of hospitalization (all types, except surgery) at 12 months as compared to prednisone, and significantly decreased the hazard of an infection at both 6 and 12 months (Table 1, Fig 1).

Conclusions

The use of Cortiment® in a real-world setting is associated with fewer deleterious outcomes, and its use during a pandemic should be preferred, especially when it’s counterpart can exacerbate negative COVID-19-related outcomes.

Table 1

Kaplan-Meier Survival Curves of 1-year Outcomes: A) All Hospitalizations; B) IBD-Related Hospitalizations; C) IBD-Specific Hospitalizations; and, D) Any Infection.

Dashed Line

Cortiment Cohort

Solid Line

Prednisone/Prednisolone Cohort

Funding Agencies

Ferring Pharmaceuticals

A211 INCIDENCE OF PRIMARY SCLEROSING CHOLANGITIS: A META-ANALYSIS OF POPULATION-BASED STUDIES

Background

Primary sclerosing cholangitis (PSC) is a chronic liver disease associated with significant morbidity, mortality and healthcare utilization. Understanding the incidence of PSC is important in defining the burden of disease and planning for allocation of healthcare resources.

Aims

To conduct a systematic review and meta-analysis of population-based studies of the incidence of PSC and to assess temporal trends of incidence overtime.

Methods

Medline and Embase (from inception to May 10, 2021) were systematically searched to identify studies via the following inclusion criteria: 1) original articles, 2) population-based study of defined geographic area, 3) reported the incidence of PSC or provided data to calculate the incidence of PSC. Studies that assessed specific populations (e.g., pediatric-only, IBD-only) or reported less than 1 year of data were excluded. Abstracts and full texts were reviewed for inclusion and data was extracted independently in duplicate by two individuals (JC, AM). Meta-analyses were performed to calculate overall and country-specific incidence rates (per 100,000 persons) with 95% confidence intervals (CI). Meta-regression calculated the Average Annual Percentage Change (AAPC) of PSC incidence rates overtime.

Results

The initial search returned 3,958 abstracts. After duplicates were removed, abstracts (3,443) were screened, and full texts were reviewed (317), 17 studies met the criteria for inclusion and underwent data extraction. Meta-analysis included 6 studies with annual data contributing to the calculation of AAPC. Studies originated from 10 countries from North America, Europe, and Oceania; however, no population-based studies were published in Asia, Africa, or Latin America (Figure 1). Overall, the incidence rates of PSC was 0.82 per 100,000 (95% CI: 0.62, 1.02) (Figure 1). Incidence rates of PSC were significantly increasing overtime (AAPC: 4.56%; 95% CI: 0.45, 8.68).

Conclusions

The incidence of PSC is low at 0.82 per 100,000 but has been significantly increasing over time. Future studies on the incidence of PSC should be directed at Asia, Africa of Latin America to assess the global epidemiology of PSC.

Figure 1: Pooled incidence rate estimates of PSC per 100,000 person-years at risk.

Funding Agencies

None

A42 HETEROGENEITY IN EFFICACY AND SAFETY ENDPOINTS FOR PEDIATRIC CLINICAL TRIALS IN INFLAMMATORY BOWEL DISEASE: A NEED FOR HARMONIZATION

NOT PUBLISHED AT AUTHOR’S REQUEST

Funding Agencies: None

A146 THE EFFECTIVENESS OF USTEKINUMAB DOSE ESCALATION IN PATIENTS WITH ULCERATIVE COLITIS

Background

Ustekinumab (UST), an IgG1 antibody that targets IL-12/23, is an effective and safe treatment option for patients with inflammatory bowel disease (IBD). Cohort studies have shown that dose escalation is an effective strategy for reinducing and maintaining remission in Crohn’s disease patients who do not respond or lose response to standard dosing of UST. There are currently no published studies evaluating effectiveness of UST dose escalation in ulcerative colitis (UC) patients.

Aims

To assess the effectiveness of UST dose escalation in patients with moderate-to-severe UC who have not responded to or lost responsiveness to standard maintenance dosing (90mg SC every 8 weeks).

Methods

A retrospective cohort study was conducted at three centers. Consecutive patients with moderate-to-severe UC initiated on ustekinumab were enrolled.

Results

Data on 43 patients (26 males) are reported (to date, patients from 1 of 3 centres have been reviewed). Mean age was 40.2 years (±15.6). Mean duration of disease was 8.5 years (±5.8). Mean duration of follow up while on UST was 8.8 months (±7.2). In total, 28% (12) of patients underwent dose escalation: 8% (1) by way of IV reinduction, 58% (7) through interval shortening (every 4 weeks), and 33% (4) by both interval shortening and IV reinduction. Mean time to first dose escalation was 6.2 months (±4.1). Mean time to second dose escalation was 5.1 months (±1.2). Seven percent (3) of patients discontinued UST, with the mean timeframe being 5.3 months (±2.9). Three patients discontinued UST due to primary non-response with one proceeding onto surgery.

Time to normalization of CRP and FCP after initiation of UST is shown in Table 1.

Conclusions

Preliminary data demonstrates that 28% of patients in this cohort required UST dose escalation, with 33% requiring a second dose escalation. Only 7% of patients discontinued UST at 9 months of follow up. Longer term follow up of this cohort would determine if dose escalation is an effective strategy to extend durability of ustekinumab.

Table 1. Normalization of CRP and FCP

Funding Agencies

None