Traditional serrated adenoma with superficially serrated adenoma: A case treated with endoscopic submucosal dissection with detailed endoscopic observation and pathological study

A new subtype of serrated lesions, superficially serrated adenoma (SuSA), has been proposed as a lesion that histopathologically exhibits the morphological features of both conventional adenomas and serrated lesions and is difficult to classify as either one. SuSA has been elucidated to be a precursor lesion of KRAS-type traditional serrated adenoma. It has also been reported that SuSA may have malignant potential. We report a case treated with endoscopic submucosal dissection and detailed observation. Endoscopy revealed a raised lesion with a two-tier raised appearance in the sigmoid colon: a tall pinecone-like reddish structure and flattened whitish elevation on white light imaging. Magnifying narrow-band imaging revealed conspicuous blood vessels in the pinecone-like structure and slightly dilated reticular vessels in the flattened area. Crystal violet staining showed that the pinecone-like structure had a type IV_H pit pattern and the flattened area had a stellate to slightly elongated type III_H pit pattern diagnosed based on Kudo's classification and other pit pattern classification systems. Ki67-positive cells were distributed in the basal and middle layers of the gland in the flattened elevated area. Genetic analysis results were positive for KRAS mutation and negative for BRAF mutation. Histopathological examination revealed a traditional serrated adenoma in the pinecone-like structure and SuSA in the adjacent flattened elevated area.

Pancreaticoduodenal Artery Aneurysm Rupture Presenting as Duodenal Obstruction Successfully Treated with Early Transcatheter Arterial Embolization: A Case Report of Suspected Segmental Arterial Mediolysis

Visceral aneurysms are a rare but important form of abdominal vascular disease. Rupture of the aneurysms leads to serious symptoms, such as acute abdomen or abdominal bleeding. However, duodenal obstruction due to arterial rupture of an aneurysm is very rare. We herein report a 50-year-old woman with suspected segmental arterial mediolysis (SAM) who was first diagnosed with acute abdomen and duodenal obstruction. Rupture of a pancreaticoduodenal artery aneurysm was confirmed, and she was treated with transcatheter arterial embolization. In cases of acute abdomen, SAM is a rare but important possibility to consider as a differential diagnosis.

Koopmans' Theorem-Compliant Long-Range Corrected (KTLC) Density Functional Mediated by Black-Box Optimization and Data-Driven Prediction for Organic Molecules

Density functional theory (DFT) is a significant computational tool that has substantially influenced chemistry, physics, and materials science. DFT necessitates parametrized approximation for determining an expected value. Hence, to predict the properties of a given molecule using DFT, appropriate parameters of the functional should be set for each molecule. Herein, we optimize the parameters of range-separated functionals (LC-BLYP and CAM-B3LYP) via Bayesian optimization (BO) to satisfy Koopmans' theorem. Our results demonstrate the effectiveness of the BO in optimizing functional parameters. Particularly, Koopmans' theorem-compliant LC-BLYP (KTLC-BLYP) shows results comparable to the experimental UV-absorption values. Furthermore, we prepared an optimized parameter dataset of KTLC-BLYP for over 3000 molecules through BO for satisfying Koopmans' theorem. We have developed a machine learning model on this dataset to predict the parameters of the LC-BLYP functional for a given molecule. The prediction model automatically predicts the appropriate parameters for a given molecule and calculates the corresponding values. The approach in this paper would be useful to develop new functionals and to update the previously developed functionals.

Protein-Ligand Interaction Analyses with Nuclear Magnetic Resonance Spectroscopy Enhanced by Dissolution Triplet Dynamic Nuclear Polarization

Solution-state nuclear magnetic resonance spectroscopy (NMR) is a powerful method for the analysis of intermolecular interactions within a biomolecular system. However, low sensitivity is one of the major obstacles of NMR. We improved the sensitivity of solution-state ¹³C NMR for the observation of intermolecular interactions between protein and ligand using hyperpolarized solution samples at room temperature. Eutectic crystals composed of ¹³C-salicylic acid and benzoic acid doped with pentacene were hyperpolarized by dynamic nuclear polarization using photoexcited triplet electrons, and a ¹³C nuclear polarization of 0.72 ± 0.07% was achieved after dissolution. The binding of human serum albumin and ¹³C-salicylate was observed with several hundred times sensitivity enhancement under mild conditions. The established ¹³C NMR was applied for pharmaceutical NMR experiments by observation of the partial return of the ¹³C chemical shift of salicylate by competitive binding with other non-isotope-labeled drugs.

Effectiveness of patient and staff cohorting to reduce the risk of vancomycin-resistant enterococcus (VRE) acquisition: a retrospective cohort study during a VRE outbreak in Japan

BACKGROUND

Patient and staff cohorting is part of a bundle approach in the response to multi-drug-resistant organisms, but its effectiveness is not fully clarified. This study compared the risks of acquiring vancomycin-resistant Enterococcus faecium (VREfm) at a hospital during a VREfm outbreak based on contact characteristics in order to better understand the effectiveness of cohorting.

METHODS

Exposure came from contact with patients with VREfm (infectors), including existing patients with VREfm and patients who acquired VREfm during the study period. Contact was defined as length of contact time, degree of sharing space, and care by the same nurses as those caring for infectors between January and March 2018. The outcome was VREfm acquisition as determined through monthly stool or rectal screening cultures. Incidence rates were calculated based on contact patterns, and incidence rate ratios (IRRs) were compared.

FINDINGS

Among 272 inpatients (4038 patient-days), 43 patients acquired VREfm with the same or similar pulsotype. Incidence rates were 8.45 per 1000 patient-days when susceptible inpatients were on the same ward as an infector but cared for by different nurses (reference), 16.96 when susceptible inpatients were on the same ward as an infector and cared for by the same nurses [IRR 2.01, 95% confidence interval (CI) 0.62-10.28], and 52.91 when susceptible inpatients shared a room with an infector (IRR 6.26, 95% CI 1.61-35.40).

CONCLUSION

Compared with susceptible inpatients in a different room from infectors and not being cared for by the same nurses, the risk of VREfm acquisition could be six times higher for susceptible inpatients who are in the same room as infectors, and could be double for susceptible inpatients cared for by the same nurses as infectors.

The optimal management of ruptured basilar artery dissecting aneurysms: a case series and scoping review

The natural history of ruptured basilar artery dissecting aneurysms (BADAs) remains unclear compared to that of ruptured vertebral artery dissecting aneurysms (VADAs). In this study, we investigated the natural history and optimal management of ruptured BADAs. We identified 17 patients with ruptured BADA among 4586 patients with aneurysmal subarachnoid hemorrhage (SAH) treated in seven participating hospitals. A scoping literature review was undertaken to investigate prognostic factors. Six patients among the profiled patients (35.3%) died, all with poor SAH grades (World Federation of Neurological Societies Grade IV and V). Rebleeding after admission was observed in three patients (17.6%) with poor SAH grades. Aggressive treatment and conservative management were initiated in seven and ten patients, respectively. Patients with good SAH grades had significantly higher favorable treatment outcomes than those with poor grades (83.3% vs. 9.1%, P = 0.005). Moreover, based on a scoping review of 158 cases with ruptured BADA, including the patients from our series, approximately 90% of patients with good SAH grades had favorable outcomes. A good SAH grade and no rebleeding after admission were favorable prognostic factors (P < 0.0001 and P = 0.002, respectively). The rebleeding rates were 20.2%, 13.3%, and 6.3% for dilated, pearl and string, and stenotic lesions, respectively. We concluded that the natural history of isolated ruptured BADAs may be better than that of VADAs. Although definitive treatment, if possible, is undoubtedly important, conservative management with careful radiological follow-up for morphological changes might be a viable option for patients in good clinical condition and with non-dilated lesions.

Factor analysis of error in oxidation potential calculation: A machine learning study

The conductor-like polarizable continuum model (C-PCM), which is a low-cost solvation model, cannot treat characteristic interactions between the solvent and substructure(s) of the solute. Moreover, the error in a charged system is significant. Using machine learning, we clarified that the systematic error of the oxidation potential calculated by the G3B3/C-PCM was correlated with the molecular size of a solute. The G3B3/C-PCM overestimated the Gibbs oxidation energy by averaging 6.94 kcal/mol. According to the performance of related methods reported in previous studies, this error is mainly due to the solvation energy of the charged solute. Additionally, we succeeded in reducing the error to 2.27 kcal/mol (32%)-3.2 kcal/mol (40%) by correction based on the substructure information of the solute. To modify the C-PCM, effects that correlate with the molecular size of the solute in the charged system should be incorporated.

AB1140 IMPACT OF COVID-19 NEWS SOURCES ON RHEUMATOID ARTHRITIS PATIENTS’ LIFESTYLE AND THEIR DISEASE ACTIVITY FROM NINJA 2020 COHORT STUDY

Background

One of the problems with the COVID-19 epidemic is infodemic. Insufficient and inaccurate information can be confusing and hinder treatment. In Japan, tabloid TV show might be an easily accessible source of information, but its reliability is low and it has a harmful effect on patients’ mental status and lifestyle. There are no reports to examine what is the source of COVID-19 news for patients with rheumatoid arthritis and how these information affect patients’ daily lives and disease activity. By using NinJa, Japanese largest database of rheumatoid arthritis, it may be possible to examine them in detail.

Objectives

To investigate the impact of the COVID—19 news sources on rheumatoid arthritis patients’ lifestyle and their disease activity using NinJa 2020 cohort study.

Methods

At the timing of collection of patients’ data of NinJa2020, questionnaire about their lifestyle and news source of COVID-19 was given. Questionnaire includes questions about frequency of scheduled visit, going out and exercise, weakness and news source.

Results

6677 patients out of 15553 patients answered questionnaire. Most patients did not change the interval of scheduled visit. The frequency of hospital visits was “unchanged” in 85.8%, “longer” in 13.6%, and “shortened” in 0.6%. The chances of going out were “unchanged” at 14.4%, “significantly decreased” at 57.5%, “slightly decreased” at 27.8%, and “increased” at 0.3%. 42.6% answered that the amount of exercise did not change, 30.2% answered that it decreased considerably, 26.1% answered that it decreased a little, and 1.1% answered that it increased. Regarding muscular strength and physical strength, 46.0% answered “no change”, 19.9% ​​answered “significantly dropped”, 33.5% answered “slightly dropped”, and 0.6% answered “increased”.

The media used as information sources are “newspaper (86.4%)”, “tabloid show (54.5%)”, “family, acquaintances and friends (43.7%)”, and “official web of Ministry of Health, Labor and Welfare and academic societies (9.4. %)”. Respondents often referred to multiple media and 30.6% of them listed three sources (Figure 1). There was a positive correlation between the decrease in frequency of going out and the number of information sources, and a negative correlation between age and the number of information sources. We also found a negative correlation with age for muscle weakness.

No correlation was found between the number of information sources and SDAI, CDAI, HAQ-DI, EQ-5D, HADS (A), HADS (D).

Figure 1.

Conclusion

The more sources of information, the less chance of going out. About 80% of the patients refrained from going out, the opportunity for exercise decreased in more than 50% of the patients, and the decrease in physical fitness was also noticed in nearly 50% of the patients. Newspapers, tabloid shows, and acquaintances were the most common sources of medical information, and relatively few patients used official sources.

He provision of accurate information about COVID-19 was important to avoid infodemic. From this questionnaire, more practical information delivery system was required in Japan.

Disclosure of Interests

None declared

AB0200 COMPARISON OF TREATMENT AND DISEASE ACTIVITY OF BETWEEN EORA AND YORA PATIENTS IN A NATIONWIDE DATABASE OF RHEUMATOID ARTHRITIS IN JAPAN “NINJA”

Background

Elderly-onset rheumatoid arthritis (EORA) has different characteristics from younger-onset RA (YORA), however, few reports have conducted large-scale and long-term comparisons of treatment and disease activity between EORA and YORA.

Objectives

To compare the changes in treatment and disease activity of between EORA and YORA patients and to examine the characteristics of patients who achieved remission between them using data of a real-world database in Japan.

Methods

Analysis was performed using data from 2010, 2013, 2016, and 2019 of the National Database of Rheumatic Diseases in Japan (NinJa). Patients were grouped according to age of disease onset into G1: <65 years (divided into G1a <65 years and G1b ≧65 years by the age at analysis), G2: 65-74 years, and G3:≧75 years.

Results

MTX usage rate decreased over time in G2 (58.3% in 2013→55.1% in 2016→54.4% in 2019) and G3 group (41.1→39.5→37.9%). Biologics/JAKi usage rate increased (G1b:24.4→28.2→ 33.3%, G2:19.1→20.3→23.7%, G3:12.3→14.5→19.1%) and steroid usage rate decreased (G1b:49.1→41.8→35.1%, G2:42.2→36.8→29.5%, G3:50.9→45.9→39.2%) in all groups. TNFi usage rate decreased (G1b:19.5→18.0→17.3%, G2:15.4→ 14.1→12.7%, G3:6.2→4.3→5.1%) but IL-6i usage rate increased (G1b:5.2→7.4→9.5%, G2:4.1→4.3→5.9%, G3:2.7→3.4→3.3%) except for the G3 group. CTLA-4Ig usage rate also increased (G1b:3.7→5.3→6.7%, G2:2.7→5.5→5.9%, G3:3.6→6.5→8.1%) in all groups.

The SDAI remission rate was increased over time in all groups (G1a:34.4→41.2→44.6%, G1b:25.1→31.4→35.2%, G2:33.1→37.1→42.2%, G3:30.0→35.9→39.3%) and EORA showed similar rate of remission with YORA. In the analysis stratified by SDAI using NinJa 2019, the positive rate of RF and ACPA decreased (ex RF. G3: 71.0→64.5→53.2%, ACPA. G3: 66.4→56.2→46.5%) and the proportion of male increased (ex G3: 23.0→30.3→35.1%) as the disease activity decreased (moderate / high → low → remission) in all groups. Also, the proportion of patients using two or more DMARDs decreased (ex G3: 43.8→35.2→22.4%) and the usage rate of steroid decreased (ex G3:52.5→37.9→30.2%). Furthermore, in a comparison of remission patients in each group, MTX usage rate (G1b:62.9→G2:61.7→G3:40.9%) and biologics/JAKi usage rate decreased (32.5→23.6→15.3%) as the age of onset increased, but the steroid usage rate increased (20.3→20.6→30.2%).

Conclusion

Disease activity improved over time, regardless of age of onset. EORA showed the same remission achievement rate as YORA, but the treatment content of those who achieved remission differed greatly depending on the age of onset.

Disclosure of Interests

Toshihiro Matsui Speakers bureau: Abbvie, Asahi Kasei, Ono, Chugai, Eli lilly, Pfizer, Grant/research support from: Abbvie, Asahi Kasei, Chugai, Shigeto Tohma: None declared

POS0614 THE RELATIONSHIP BETWEEN DISEASE ACTIVITY AND FINANCIAL TOXICITY IN PATIENTS WITH RHEUMATOID ARTHRITIS ON BIOLOGICS: A CROSS-SECTIONAL STUDY USING THE JAPANESE RHEUMATOID ARTHRITIS REGISTRY

Background

As the number of rheumatoid arthritis (RA) patients using biologics increases, the health financial issues posed by biologics become more important. The health financial issues posed by biologics have been discussed using health economic indicators such as incremental cost-effectiveness ratios (ICERs), but have not been evaluated using the financial burden of medical expenses (financial toxicity). In the field of malignancies, evaluations using financial burden have been conducted and have shown that the stage of malignancy is associated with financial toxicity. It is not known whether disease activity and financial toxicity are similarly associated in RA patients.

Objectives

This study aims to evaluate the relationship between RA activity and financial toxicity in RA patients using biologics, who are especially likely to feel the financial burdens.

Methods

We conducted a cross-sectional study of biologic users enrolled in NinJa2020, a database of rheumatoid arthritis patients in Japan collected from April 1, 2020 to March 31, 2021. We defined the users of TNF inhibitor, IL-6 receptor antagonists, T-cell costimulation blocker, Janus kinase inhibitor and biosimilar as biologic users. The main exposure was the disease activity of RA and was measured using DAS28-CRP. Outcome measure was a financial toxicity and was measured using COmprehensive Score for financial Toxicity (COST). This scale is a patient-reported outcome measure (PROM) consisting of 11 items. The responses are recorded on 5-point Likert Scales (ranging from 0 = strongly disagree to 4 = strongly agree). The score by domains ranges from 0 to 44. Higher scores indicated better results and lower financial toxicity. Multiple linear regression models adjusted for age, sex, disease duration, co-payments for anti-rheumatic drugs, work status, financial support systems were conducted to assess the relationship between the disease activity of RA and financial toxicity. As a secondary analysis, we excluded patients with zero copayments and performed the same analysis as in the main analysis. We used multiple imputation to deal with missing values.

Results

Among 15553 cases in the NinJa database, 649 cases for which RA disease activity and COST were available were included. The median age of the patients was 70 (interquartile range [IQR],56 -77), 83.7% were female. The median copayment amount was ¥12978 per month (IQR 637.2 to 24204.1). The median DAS28-CRP was 1.99 (IQR, 1. - 2.72). The median financial toxicity (COST score) was 21 (IQR 0-27) (Figure 1). In the main analysis using multiple linear regression, COST significantly decreased with disease activity of RA (per 1-pt DAS28-CRP, -1.16 [95% CI -2.04 - -0.28]). In the secondary analysis, COST significantly decreased with disease activity of RA (per 1-pt DAS28-CRP, -1.69 [95% CI -2.29 - -1.10]). Statistical significance was defined as a two-sided p-value < 0.05. All statistical analyses were conducted using STATA 17.0 (Stata Corp LP, College Station, TX). The National Hospital Organization’s research ethics committees evaluated and authorized the NinJa study.

Conclusion

High disease activity of RA was associated with high financial toxicity in biologic users. We reaffirmed the importance of financial considerations and empathy for RA patients using biologics, and suggested a potential demand for more financial support for RA patients who are refractory to treatment.

Disclosure of Interests

None declared

Spontaneous regression of a rectal tonsil presenting as a large submucosal tumor

Rectal tonsils are localized hyperplastic lymphoid tissues in the rectum, and the initial endoscopic findings are consistent with those for neoplastic lesions. However, rectal tonsils are benign entities, and the diagnosis should be made cautiously. A 70‐year‐old man presented with pain on defecation with rectal bleeding. Colonoscopy revealed a 3‐cm protruding mass in the rectum with mucosal erosion, but no malignant features were observed on forceps biopsy. Endoscopic ultrasonography (EUS) showed that the lesion was a hypoechoic mass without blood flow. Fine needle aspiration under EUS revealed no malignant components, although the size of the lesion had shrunk, and symptoms, such as blood‐stained stool, tenesmus, and discomfort during defecation, had resolved. A second forceps biopsy showed intermediate‐sized lymphocytes without lymphoepithelial lesions. Based on immunostaining, the lesion was diagnosed as a rectal tonsil.

Rectal tonsils occur due to localized proliferation of reactive lymphoid follicles in the submucosa or muscularis mucosa. However, endoscopic diagnosis is difficult since less invasive treatment is performed for neoplastic lesions of the rectum to preserve the function of the anal sphincter. Diagnosis and treatment of small lesions might be possible by endoscopic resection; however, for relatively large lesions, formulating a diagnosis based only on biopsy specimens becomes even more difficult. Therefore, repeated biopsies might be helpful for the diagnosis of rectal tonsils and for excluding other neoplasms.

[A Case of Effective Chemoradiotherapy for the Treatment of Distant Recurrence of Squamous Cell Carcinoma in the Anal Canal]

A 75-year-old woman diagnosed with squamous cell carcinoma of the anal canal was treated using chemoradiotherapy and revealed a complete response to the tumor. After 6 months of treatment, swollen para-aortic lymph nodes were found to develop. The patient received the same regimen of chemoradiotherapy again, resulting in lymph node disappearance. However, 2 months later, PET-CT revealed accumulation of FDG in the axillary and cervical lymph nodes. Chemoradiotherapy was performed for the third time. Swollen lymph nodes were found to disappear. After 12 months, para-aortic, axillary, and cervical lymph nodes developed, following which she received BSC; subsequently, she died after 38 months of the carcinoma diagnosis.

Large-Scale Prospective Genome-Wide Association Study of Oxaliplatin in Stage II/III Colon Cancer and Neuropathy

IMPORTANCE

The severity of oxaliplatin (L-OHP)-induced peripheral sensory neuropathy (PSN) exhibits substantial interpatient variability, and some patients suffer from long-term, persisting PSN.

OBJECTIVE

To identify single-nucleotide polymorphisms (SNPs) predicting L-OHP-induced PSN using a genome-wide association study (GWAS) approach.

DESIGN, SETTING, PARTICIPANTS

A large prospective GWAS including 1,379 patients with stage II/III colon cancer who received L-OHP-based adjuvant chemotherapy (mFOLFOX6/CAPOX) under the phase II (JOIN/JFMC41) or the phase III (ACHIVE/JFMC47) trial.

MAIN OUTCOMES AND MEASURES

First, GWAS comparison of worst grade PSN (grade 0/1 vs. 2/3) was performed. Next, to minimize the impact of ambiguity in PSN grading, extreme PSN phenotypes were selected and analyzed by GWAS. SNPs that could predict time to recovery from PSN were also evaluated. In addition, SNPs associated with L-OHP-induced allergic reactions (AR) and time to disease recurrence were explored.

RESULTS

No SNPs exceeded the genome-wide significance (p < 5.0 × 10^-8) in either GWAS comparison of worst grade PSN, extreme PSN phenotypes, or time to recovery from PSN. Association study focusing on AR or time to disease recurrence also failed to reveal any significant SNPs.

CONCLUSION AND RELEVANCE

Our results highlight the challenges of utilizing SNPs for predicting susceptibility to L-OHP-induced PSN in daily clinical practice.

Carotid endarterectomy restores decreased vision due to chronic ocular ischemia

BACKGROUND

The therapeutic effect of carotid endarterectomy (CEA) on visual disturbance caused by chronic ocular ischemia due to carotid artery stenosis has not been validated. This prospective observational study aims to investigate whether CEA is associated with an increase in ocular blood flow (OBF) and postoperative visual improvement.

METHODS

In total, 41 patients with carotid artery stenosis treated by CEA between March 2015 and September 2018 were enrolled in this study. OBF was evaluated by laser speckle flowgraphy, which can measure the mean blur ratio (MBR) which is well correlated to the absolute retinal blood flow. Visual acuity was assessed before and after CEA by subjective improvement and objective visual assessment using CSV-1000, an instrument used to test contrast sensitivity.

RESULTS

OBF increased after CEA on the operated side (mean MBR 33.5 vs 38.2, p < 0.001) but not on the non-operated side (mean MBR 37.8 vs 37.5, p = 0.50). After CEA, 23 patients (56.1%) reported subjective visual improvement on the operated side. The mean CSV-1000 score among the patients with increased OBF after CEA (5.44 vs 5.88, p = 0.04) but not among those without increased OBF (5.48 vs 5.95, p = 0.09). The mean CSV-1000 scores increased significantly after CEA in 18 patients with decreased vision and decreased OBF (4.51 vs 5.37, p < 0.001), but not in the 23 patients without those (6.19 vs 6.31, p = 0.6).

CONCLUSION

CEA may successfully reverse visual dysfunction caused by chronic ocular ischemia due to carotid artery stenosis by increasing OBF.

POS0286 INCIDENCE OF MALIGNANCIES IN JAPANESE PATIENTS WITH RHEUMATOID ARTHRITIS: DATA FROM A LARGE JAPANESE NATIONAL REGISTRY

Background:

Patients (pts) with rheumatoid arthritis (RA) have an increased risk of some malignancies vs the general population, and this can vary by region/race.1,2 Data on the epidemiology and impact of biological (b)DMARDs and targeted synthetic (ts)DMARDs, such as Janus kinase (JAK) inhibitors, on the incidence of malignancies in Japanese pts with RA are limited. The National Database of Rheumatic Diseases in Japan (NinJa) is one of the largest RA registries in Japan.

Objectives:

To evaluate the incidence of malignancies in Japanese pts with RA using NinJa registry data.

Methods:

This retrospective observational study analysed NinJa registry data for Japanese pts with RA aged ≥18 years with ≥1 data entry between 2013 (first JAK inhibitor approval for RA in Japan) and 2018. The overall cohort included all pts with RA, and two sub-cohorts were analysed: pts exposed and unexposed to bDMARDs (exposure defined as ≥1 bDMARD reported in database). Crude incidence rates (IRs) for malignancies (including non-melanoma skin cancer) were calculated as the number of events per 100 pt-years of follow-up (time between start of follow-up or the date of first bDMARD exposure [for bDMARD-exposed pts] and end of observation period, or withdrawal from database). The most recent data for incidence of malignancy in the Japanese general population (2013–2017 data from the National Cancer Center, Japan) were used to calculate standardised incidence ratios (SIRs) and age- and sex-adjusted standardised rates (ASRs) for malignancies. Cross-sectional (per calendar year) and cumulative analyses were performed for the overall cohort. Cumulative rates were calculated for sub-cohorts, and all cumulative analyses were repeated excluding pts exposed to JAK inhibitors (ie ≥1 JAK inhibitor reported in database).

Results:

Data were collected for 26 607 Japanese pts with RA from 2013–2018. In the cross-sectional analysis (Table 1), the SIR and ASR for malignancies in all pts with RA were generally consistent from 2013–2018. In the cumulative analysis, the SIR (95% CI) for malignancies from 2013–2018 was 0.97 (0.91, 1.03) in all pts with RA, and 0.93 (0.82, 1.04) and 0.99 (0.92, 1.07) in pts exposed and unexposed to bDMARDs, respectively (Figure 1). Adjusting for age/sex, the cumulative ASR (95% CI) for malignancies from 2013–2018 was 0.83 (0.76, 0.90) in all pts with RA, and 0.82 (0.69, 0.95) and 0.86 (0.77, 0.96) in pts exposed and unexposed to bDMARDs, respectively (Figure 1). In all cohorts, the cumulative SIR and ASR were similar when pts exposed to JAK inhibitors were excluded (Figure 1).

Table 1.

Cross-sectional analysis of the incidence of malignancies in Japanese pts with RA from 2013–2018

All RA2013 (N=13 423)2014 (N=15 584)2015 (N=15 751)2016 (N=16 107)2017 (N=15 994)2018(N=15 003)Total follow-up, PY13 35314 86614 82914 97014 74814 898Pts with events, n140164174168161211Crude IRa(95% CI)1.05(0.89, 1.24)1.10(0.95, 1.29)1.17(1.01, 1.36)1.12(0.97, 1.31)1.09(0.94, 1.27)1.42(1.24, 1.62)ASRa,b(95% CI)0.76(0.60, 0.93)0.76(0.62, 0.90)0.90(0.68, 1.11)0.88(0.68, 1.07)0.80(0.62, 0.98)0.88(0.74, 1.01)SIRb(95% CI)0.97(0.82, 1.14)1.01(0.86, 1.17)1.02(0.87, 1.18)0.88(0.75, 1.02)0.86(0.73, 1.00)1.10(0.95, 1.25)

aIR/ASR were calculated as number of events per 100 PY of follow-up

bData from a Japanese general population database of malignancy incidence from 2013–2017, provided by the Center for Cancer Control and Information Services, National Cancer Center, Japan

PY, pt-years

Conclusion:

The incidence of malignancies in Japanese pts with RA, registered in the NinJa database from 2013–2018, was similar to that in the Japanese general population. The SIR and ASR for malignancies were comparable in pts exposed and unexposed to bDMARDs. In all cohorts, rates did not increase when pts exposed to JAK inhibitors were included.

References:

[1] Dougados et al. Ann Rheum Dis 2014; 73: 62-68.

[2] Parikh-Patel et al. Cancer Causes Control 2009; 20: 1001-1010.

Acknowledgements:

Study sponsored by Pfizer Inc. Medical writing support was provided by Christina Viegelmann, CMC Connect, and funded by Pfizer Inc.

Disclosure of Interests:

Toshihiro Matsui Speakers bureau: Astellas, Ayumi, Chugai, Daiichi-Sankyo, Eli Lilly, Ono, Pfizer Inc, Takeda, Tanabe-Mitsubishi, Consultant of: Pfizer Inc, Grant/research support from: Chugai, Naonobu Sugiyama Shareholder of: Pfizer Inc, Employee of: Pfizer Inc, Shigeyuki Toyoizumi Employee of: Pfizer R&D Japan, Fujio Matsuyama Consultant of: Pfizer Inc, Employee of: CRECON Medical Assessment Inc, Tatsunori Murata Consultant of: Pfizer Inc, Employee of: CRECON Medical Assessment Inc, Yukitomo Urata Speakers bureau: Asahi Kasei, Chugai, Eli Lilly, Pfizer Inc, Consultant of: AbbVie, Asahi Kasei, Chugai, Pfizer Inc, Kimito Kawahata Speakers bureau: Pfizer Inc, Consultant of: Pfizer Inc, Grant/research support from: Pfizer Inc, Shigeto Tohma Speakers bureau: Astellas, Ayumi, Chugai, Ono, Pfizer Inc, Takeda, Consultant of: Pfizer Inc

Unique Photophysical Properties of 1,8-Naphthalimide Derivatives: Generation of Semi-stable Radical Anion Species by Photo-Induced Electron Transfer from a Carboxy Group

The development of anion sensors for selective detection of a specific anion is a crucial research topic. We previously reported a selective photo-induced colorimetric reaction of 1-methyl-3-(N-(1,8-naphthalimidyl)ethyl)imidazolium (MNEI) having a cationic receptor in the presence of molecules having multiple carboxy groups, such as succinate, citrate, and polyacrylate. However, the mechanism underlying this reaction was not clarified. Here, we investigate the photo-induced colorimetric reaction of N-[2-(trimethylammonium)ethyl]-1,8-naphthalimide (TENI), which has a different cationic receptor from MNEI and undergoes the photo-induced colorimetric reaction, and its analogues to clarify the reaction mechanism. The TENI analogues having substituents on the naphthalene ring provide important evidence, suggesting that the colorimetric chemical species were radical anions generated via photo-induced electron transfer from carboxylate to the naphthalimide derivative. The generation of the naphthalimide-based radical anion is verified by ¹H NMR and cyclic voltammetry analyses, and photo-reduction of methylene blue is mediated by TENI. In addition, the role of the cationic receptor for the photo-induced colorimetric reaction is investigated with TENI analogues having different hydrophilic groups instead of the trimethylammonium group. Interestingly, the photo-induced colorimetric reaction is observed in a nonionic analogue having a polyethylene glycol group, indicating that the colorimetric reaction does not require a cationic receptor. On the other hand, we reveal that the trimethylammonium group stabilizes the radical anion species. These generation and stabilization phenomena of naphthalimide-based radical anion species will contribute to the development of sophisticated detection systems specific for carboxylate.

Risk factors of meralgia paresthetica after prone position surgery: Possible influence of operating position, laminectomy level, and preoperative thoracic kyphosis

Obesity and a prolonged surgical duration are reported risk factors for meralgia paresthetica (MP) after prone position surgery; however, this fails to explain why MP seldom occurs after prone position craniotomy. We reviewed the incidence of MP after spinal surgery and craniotomy in the prone position and investigated whether unidentified factors are involved in the mechanism of postoperative MP. Between January 2014 and March 2020, we performed 556 prone position surgeries. We excluded patients aged ≤16 years and those who were comatose or who required redo-surgery, and reviewed 446 eligible patients (124 who underwent craniotomies and 322 who underwent posterior spinal surgeries). Postoperative MP occurred in 46 (10.3%) patients with a higher incidence after spinal surgery than after craniotomy (13.7% vs. 1.6%, p < 0.001). Among the 322 patients who received posterior spinal surgery, thoracic and lumbar laminectomies were associated with a higher incidence of MP than cervical laminectomy. Analyses limited to those patients who received thoracic and lumbar laminectomies revealed that the preoperative thoracic kyphosis (TK) angle was significantly greater in patients with MP than in those without MP (average TK angle, 38.9° vs. 23.1°; p < 0.001), and that the preoperative lumbar lordosis angle did not significantly differ between the two groups. Apart from the known predisposing factors, we found that thoracolumbar-sacral laminectomy in patients with a greater TK angle is also a risk factor for MP after prone position surgery.

Trigeminal neuralgia caused by an arachnoid cyst in Meckel's cave: A case report and literature review

Background:

We present a rare case of trigeminal neuralgia (TN) caused by an arachnoid cyst (AC) in Meckel’s cave (MC).

Case Description:

A 35-year-old man presented with facial pain in the left maxillary and mandibular regions. Since the initial magnetic resonance (MR) imaging showed no apparent offending vessels or tumors, the patient was diagnosed with idiopathic TN, for which carbamazepine was initially effective. When his pain worsened, he was referred to our hospital. A slightly asymmetric shape of MC and distorted course of the trigeminal nerve was confirmed on the initial and repeat MR images. His pain was characterized as electric-shock-like pain, which was triggered by touching the face. Under the tentative diagnosis of an AC confined to MC compressing the trigeminal nerve, the exploration of MC through suboccipital craniotomy was performed. Intraoperatively, the AC was identified in the rostral portion of MC. The indentation of the trigeminal nerve was also observed at the orifice of MC, indicating severe compression by the AC. The wall of the AC was fenestrated. The patient’s pain was relieved immediately after surgery. Postoperative MR images showed that the course of the trigeminal nerve was straightened. Although our literature review found five similar cases, the size of the AC was the smallest in our case.

Conclusion:

Although it is rare, the AC confined to MC can cause TN. The findings of this study emphasize the importance of evaluating subtle radiological findings of compression on the trigeminal nerve in cases of TN seemingly without neurovascular compression.

A Prospective Randomized Study on the Preventive Effect of Japanese Herbal Kampo Medicine Goreisan for Recurrence of Chronic Subdural Hematoma

Although the recurrence of chronic subdural hematoma (CSDH) after surgical treatment significantly affects the patients' quality of life, the recurrence rate has not improved in decades. Goreisan, a Japanese herbal Kampo medicine, promotes the hydragogue effect and has been empirically used in the treatment of CSDH in Japan. We conducted a prospective randomized study to investigate whether Goreisan treatment decreases the recurrence rate of CSDH. Between March 2013 and December 2018, a total of 224 patients who underwent initial burr hole surgery for CSDH were randomly assigned to receive Goreisan for 3 months (Group G) or no medication (Group N). The primary endpoint was symptomatic recurrence within 3 months postoperatively, and the secondary endpoint was complications, including the adverse effects of Goreisan. Of 224 randomized patients, 208 were included in the final analysis (104 in Group G and 104 in Group N). The overall recurrence rate was 9.1% (19/208). The recurrence rate of Group G was lower than that of Group N (5.8% vs 12.5%, P = 0.09), but the difference was not statistically significant. However, a significant preventive effect of Goreisan was found in 145 patients with high-risk computed tomography (CT) features, namely, homogeneous and separated types (5.6% vs 17.6%, P = 0.04). Although the present study did not prove the beneficial effect of Goreisan treatment, it suggested the importance of selecting patients with an increased risk of recurrence. A subset of patients whose hematoma showed homogeneous and separated patterns on CT image might benefit from Goreisan treatment.

Masked malignant phenotype with a benign appearance: beat-up copy number profile may be the key for hemangioblastoma dissemination

Dissemination of histologically benign hemangioblastoma is rare; approximately 30 cases have previously been reported, and all cases occurred several months to years after surgical resection. Herein, we report a case of hemangioblastoma in which leptomeningeal dissemination occurred 2 years after hypofractionated radiation therapy (39 Gy/13 fractions). The tumor was treated primarily with radiation without surgical resection. Biopsy of the disseminated lesion confirmed histological diagnosis as histologically benign hemangioblastoma. Ki67 index was not remarkably elevated for hemangioblastomas. In addition, the methylation class determined by the methylation profiling classifier developed by the German Cancer Research Center (DKFZ)/University Hospital Heidelberg/German Consortium for Translational Cancer Research was consistent with that of common hemangioblastomas. However, genetic analyses showed significant gains and losses throughout the whole genome, indicating that highly aberrant copy number profiles may be the key to elucidating this rare but life-threatening clinical entity. Accumulation of more detailed case reports based on the comparison of specimens obtained before and after surgery or radiation is necessary to better understand the pathophysiology of the dissemination phenotype of hemangioblastoma.

SAT0124 RISK OF SERIOUS INFECTION, MALIGNANCY, OR DEATH IN JAPANESE RHEUMATOID ARTHRITIS PATIENTS TREATED WITH A COMBINATION OF ABATACEPT AND TACROLIMUS: A RETROSPECTIVE COHORT STUDY

Background:

Both Abatacept (ABT) and Tacrolimus (Tac) suppress T cell immunity, but it is unknown whether combinations of these will increase the risk of adverse events.

Objectives:

To evaluate whether combining ABT and Tac increases the risk of infection and malignancy compared to their individual use in Japanese rheumatoid arthritis (RA) patients.

Methods:

We conducted a retrospective cohort study of RA patients using the multicenter database in Japan (NinJa). The dataset was clinical information at a certain point within each year, and the point was any point selected by a registered physician. RA was clinically diagnosed in the dataset. (1)

We analyzed the data from RA patients registered in NinJa during the period from April 2010 to March 2019. In this study, we compared three groups who received Tac, ABT or a combination of both. We included patients who had just begun initiating treatment with ABT or Tac, and we excluded patients who used TNF inhibitors, IL-6 inhibitors, and Jak inhibitors in the first year. The primary outcome was defined the composite events including infections that require hospitalization, newly diagnosed malignancy, and death from any cause after initiation of ABT or Tac. We assessed whether the combination contributed to increase the risk of outcome by performing a Cox regression analysis.

Results:

Among the 27032 RA patients in the registry, 2009 patients were included. The Tac, ABT and combination groups consisted of 1328, 563 and 118 patients, respectively. (Figure 1) (Table 1) Primary outcomes occurred in 149 (13.4%), 62 (13.5%), 14 (13.9%) patients, of the Tac, ABT and combination groups, respectively. The incidence between groups was not significantly different (p= 0.638). (Figure 2) A Cox regression analysis was adjusted for the following parameters: age, sex, disease duration, modified health assessment questionnaire, disease activity score 28-CRP, CRP, use of prednisolone, and use of methotrexate. The analysis revealed no significant differences between groups. The hazard ratio (95% confidence interval) was as follows: Tac 1.00 (Ref), ABT 1.02 (0.74-1.40), and combination 1.15 (0.65-2.05).

Table 1.

baseline characteristics

TacrolimusAbataceptCombinationp valueN (person-year)1328 (2505)563 (944)118 (193)age (median [IQR])69.00 [60.00, 76.00]70.00 [61.00, 76.00]67.00 [59.00, 74.00]0.169*sex female (%)1038 (78.2)468 (83.1)97 (82.2)0.039†disease duration (yr) (median [IQR])9.00 [4.00, 18.00]11.00 [5.00, 21.00]11.00 [7.00, 20.00]0.002*Steinbrocker stage (%)I285 (23.5)82 (15.6)12 (12.1)<0.001†II361 (29.8)125 (23.8)25 (25.3)III232 (19.1)150 (28.5)31 (31.3)IV334 (27.6)169 (32.1)31 (31.3)mHAQ (median [IQR])0.25 [0.00, 0.75]0.38 [0.00, 1.00]0.50 [0.00, 1.13]<0.001*DAS28CRP (median [IQR])2.58 [1.88, 3.40]2.77 [2.09, 3.62]3.01 [2.27, 3.98]<0.001*CRP (mg/dL) (median [IQR])0.30 [0.10, 1.02]0.35 [0.13, 1.10]0.30 [0.14, 0.82]0.590*RF positivity (%)708/895 (79.1)331/400 (82.8)57/71 (80.3)0.314†Tacrolimus (mg/d) (median [IQR])1.50 [1.00, 2.00]0.00 [0.00, 0.00]2.00 [1.00, 2.50]<0.001*MTX use (%)619 (46.6)264 (46.9)32 (27.1)<0.001†PSL use (%)749 (56.4)299 (53.1)71 (60.2)0.253†

Abbreviations: anti-CCP, anti-cyclic citrullinated peptide; mHAQ, modified Health Assessment Questionnaire; MTX, methotrexate; PSL, prednisolone; RF, rheumatoid factor * Kruskal-Wallis test; † chi square test; ‡ analysis of variance (ANOVA)

Conclusion:

The combination of ABT and Tac does not increase the risk of adverse events in patients with rheumatoid arthritis in Japan when compared to the use ABT or Tac alone. Further evaluation is needed.

References:

[1]Matsui T, et al. Ann Rheum Dis 2007;66:1221–6.

Disclosure of Interests:

Kenichiro Tokunaga: None declared, Kunihiko Matsui: None declared, Hideto Oshikawa: None declared, Toshihiro Matsui Paid instructor for: Chugai Pharmaceutical Co., LTD., Janssen Pharmaceutical K,K,, Shigeto Tohma: None declared

Extirpation of a Ruptured Anterior Spinal Artery Aneurysm Accompanied by Dural Arteriovenous Fistula at the Craniovertebral Junction via a Posterolateral Approach: The Management of Extradural Venous Congestion

Objective  This study was aimed to discuss how to control extradural venous congestion with an increased pressure in cases of arteriovenous shunt disease of the craniovertebral junction.

Design  The study is presented through an operative video.

Results  A 77-year-old patient with subarachnoid hemorrhage had a dural arteriovenous fistula located at the C1–C2 level. Left vertebral angiography showed a fistula between the left C2 radiculomeningeal muscular artery and perivertebral plexus. Furthermore, right vertebral angiography showed a ruptured aneurysm at the aberrant branch of the anterior spinal artery originating from the contralateral vertebral artery (VA), possibly formed because of the concurrently increased pressure of the perimedullary veins. Aneurysm extirpation was planned through a posterolateral approach. To reduce venous bleeding during the approach, preoperative embolization of the radiculomeningeal muscular artery was performed. During surgery, the suboccipital triangle was exposed following layer-by-layer dissection of the suboccipital muscles ( Figs. 1 and 2 ). Subperiosteal dissection of the paravertebral plexus surrounding the VA around the C1 lamina was effective to avoid venous bleeding. A bloodless operative field was achieved, and key anatomical structures, such as the C2 nerve root, feeder, and V3 portion of the left VA, were clearly identified. With a sufficient amount of lateral exposure, the ruptured anterior spinal artery aneurysm was successfully extirpated with bipolar coagulation. The patient was discharged with no neurologic deficit.

Conclusion  Controlling extradural venous congestion is essential to obtain a clear operative field in cases of arteriovenous shunt disease at the craniovertebral junction.

The link to the video can be found at: https://youtu.be/fCT69WtAQbo .

A Large Carcinosarcoma of the Gallbladder Accompanied by Pancreaticobiliary Maljunction: A Case with a Six-year Survival

Pancreatobiliary maljunction (PBM) is a rare congenital malformation, often associated with adenocarcinoma. However, PBM accompanying gallbladder carcinosarcoma has rarely been reported. A 72-year-old woman was referred to our hospital, complaining of abdominal pain. Computed tomography showed a polypoid mass in the gallbladder. Endoscopic retrograde cholangiopancreatography showed PBM, and aspirated bile demonstrated elevated levels of pancreatic-type amylase (26,780 U/L) and cancer cells. Extended cholecystectomy was performed. Histologically, the tumor had adenocarcinoma, squamous cell carcinoma and sarcoma components. Despite the large tumor size (84 mm) and intra-vessel cancer permeations, this patient has been healthy for 73 months since the surgery.

Randomized clinical trial of extensive intraoperative peritoneal lavage versus standard treatment for resectable advanced gastric cancer (CCOG 1102 trial)

BACKGROUND

A survival benefit of extensive intraoperative peritoneal lavage (EIPL) has been reported in patients with gastric cancer with positive peritoneal cytology. The hypothesis of this study was that EIPL may reduce peritoneal recurrence in patients with advanced gastric cancer who undergo surgery with curative intent.

METHODS

This was an open-label, multi-institutional, randomized, phase 3 trial to assess the effects of EIPL versus standard treatment after curative gastrectomy for resectable gastric cancer of T3 status or above. The primary endpoint was disease-free survival (DFS); secondary endpoints were overall survival, peritoneal recurrence-free survival and incidence of adverse events.

RESULTS

Between July 2011 and January 2014, 314 patients were enrolled from 15 institutions and 295 patients were analysed (145 and 150 in the EIPL and no-EIPL groups respectively). The 3-year DFS rate was 63·9 (95 per cent c.i. 55·5 to 71·2) per cent in the EIPL group and 59·7 (51·3 to 67·1) per cent in the control group (hazard ratio (HR) 0·81, 95 per cent c.i. 0·57 to 1·16; P = 0·249). The 3-year overall survival rate was 75·0 (67·1 to 81·3) per cent in the EIPL group and 73·7 (65·9 to 80·1) per cent in the control group (HR 0·91, 0·60 to 1·37; P = 0·634). Peritoneal recurrence-free survival was not significantly different between the two groups (HR 0·92, 0·62 to 1·36; P = 0·676). No intraoperative complications related to EIPL were observed.

CONCLUSION

EIPL did not improve survival or peritoneal recurrence in patients who underwent gastrectomy for advanced gastric cancer. Registration number: 000005907 (http://www.umin.ac.jp/ctr/index.htm).

Prevention of Thromboembolic Infarction After Surgery for Traumatic Cervical Fracture with Vertebral Artery Occlusion by Preoperative Endovascular Coil Embolization

BACKGROUND

Vertebral artery injuries (VAIs) caused by cervical trauma include irregularities with narrowing of the arterial wall, dissection, pseudoaneurysm formation, occlusion, and transection. Although recent guidelines have recommended anticoagulant or antiplatelet therapy to prevent subsequent stroke in patients with traumatic VAIs, regardless of the type of vascular injury, the clinical role of endovascular surgery in the treatment of traumatic VAIs remains to be elucidated.

METHODS

We retrospectively evaluated the treatment outcomes of 23 patients with cervical fracture and vertebral artery occlusion (VAO) who had required cervical surgery in the acute stage.

RESULTS

No patient received antiplatelet or anticoagulant therapy, because the VAs had already become occluded. After cervical surgery, 5 of the 23 patients developed radiologically confirmed thromboembolic stroke after cervical surgery. None of these 5 patients with postoperative infarction had undergone preoperative VA embolization. Univariate analysis revealed that only the implementation of preoperative VA embolization was associated with the prevention of postoperative infarction (P = 0.004). Factors such as age, reduction, level of VAO, and diabetes mellitus did not correlate with increased risk.

CONCLUSIONS

The clinical role of endovascular surgery for traumatic VAI has not been previously established; however, a more specific selection of patients according to the VAI type might be necessary. Our data have indicated that preoperative embolization of the occluded VA significantly reduces the risk of postoperative infarction in a specific cohort of patients with traumatic VAI (i.e., patients with post-traumatic VAO who require cervical surgery).

Intraoperative quantification of meningioma cell proliferation potential using rapid flow cytometry reveals intratumoral heterogeneity

Background

Standard sampling methods to evaluate the proliferative ability of meningioma have not been established.

Methods

This prospective study was conducted to evaluate the effectiveness of intraoperative rapid flow cytometry (iFC) using raw samples for the quantitative assessment of proliferative ability in meningioma cells and to investigate intratumoral heterogeneity. Proliferation index (PI) was defined as the ratio of aneuploid cells with an abnormal number of chromosomes to the total cells.

Results

From 50 patients, 118 specimens were analyzed. There was a statistically significant correlation between the postoperative MIB‐1 labeling index (LI) and PI (R = 0.59, P < 0.0001). A higher PI was correlated with a higher annual growth rate (AGR, cm³/y) (R = 0.50, P = 0.0002, 26 patients). AGR showed a correlation with the intratumoral distribution of PI. PI was the highest at the center or the peripheral section of the tumor in tumors with high AGR, whereas it was highest at the dural attachment in tumors with low AGR (P = 0.039, n = 20). Pial feeders were more frequently observed when PI was high in the center or in the peripheral section (P = 0.006, n = 37).

Conclusions

Rapid iFC may thus become a substitute for MIB‐1 LI. Intratumoral heterogeneity of cellular proliferative potential exists in meningiomas and is related to tumor biological characteristics such as AGR and development of pial feeders. This observation underscores the importance of standardization in the sampling method to accurately estimate the risk of meningioma recurrence.

Superficial temporal artery-superior cerebellar artery bypass and trapping of a fusiform aneurysm using intradural anterior petrosectomy: technical case report and anatomical study

Aneurysms at the distal portion of the superior cerebellar artery (SCA) are very rare. Because of the deep location and a propensity for nonsaccular morphology, aneurysm trapping or endovascular occlusion of the parent artery are the usual treatment options, which are associated with varying risks of ischemic complications. The authors report on a 60-year-old woman who had a 3.5-mm unruptured aneurysm in the lateral pontomesencephalic segment of the SCA with a significant interval growth to 8 mm. Direct surgical intervention comprising trapping of the aneurysm through a subtemporal approach and intradural anterior petrosectomy combined with revascularization of the distal SCA using the superficial temporal artery (STA) was performed. This approach provided sufficient space for the bypass instruments to be introduced into the deep surgical field at a more favorable angle to enhance microscopic visualization of the anastomosis with minimal retraction of the temporal lobe. The patient was discharged with no neurological deficit. Preservation of the blood flow in the distal SCA should be attempted to minimize the risk of ischemic injury, particularly when the aneurysms arise in the anterior or lateral segment of the SCA. The authors demonstrate the safety and effectiveness of the intradural anterior petrosectomy for STA-SCA bypass along with a relevant anatomical study.

A computational scheme of pKa values based on the three-dimensional reference interaction site model self-consistent field theory coupled with the linear fitting correction scheme

A scheme for quantitatively computing the acid dissociation constant, pKa, of hydrated molecules is proposed. It is based on the three-dimensional reference interaction site model self-consistent field (3D-RISM-SCF) theory coupled with the linear fitting correction (LFC) scheme. In LFC/3D-RISM-SCF, pKa values of target molecules are evaluated using the Gibbs energy difference between the protonated and unprotonated states calculated by 3D-RISM-SCF and the parameters fitted by the LFC scheme to the experimental values of training set systems. The pKa values computed by LFC/3D-RISM-SCF show quantitative agreement with the experimental data.