In Situ Derived Hybrid Carbon Molecular Sieve Membranes with Tailored Ultramicroporosity for Efficient Gas Separation

Fine control of ultramicroporosity (<7 Å) in carbon molecular sieve (CMS) membranes is highly desirable for challenging gas separation processes. Here, a versatile approach is proposed to fabricate hybrid CMS (HCMS) membranes with unique textural properties as well as tunable ultramicroporosity. The HCMS membranes are formed by pyrolysis of a polymer nanocomposite precursor containing metal-organic frameworks (MOFs) as a carbonizable nanoporous filler. The MOF-derived carbonaceous phase displays good compatibility with the polymer-derived carbon matrix due to the homogeneity of the two carbon phases, substantially enhancing the mechanical robustness of the resultant HCMS membranes. Detailed structural analyses reveal that the in situ pyrolysis of embedded MOFs induces more densified and interconnected carbon structures in HCMS membranes compared to those in conventional CMS membranes, leading to bimodal and narrow pore size distributions in the ultramicroporous region. Eventually, the HCMS membranes exhibit far superior gas separation performances with a strong size-sieving ability than the conventional polymers and CMS membranes, especially for closely sized gas pairs (Δd < 0.5 Å) including CO₂ /CH₄ and C₃ H₆ /C₃ H₈ separations. More importantly, the developed HCMS material is successfully prepared into a thin-film composite (TFC) membrane (≈1 µm), demonstrating its practical feasibility for use in industrial mixed-gas operation conditions.

Defect Engineering in Metal-Organic Frameworks Towards Advanced Mixed Matrix Membranes for Efficient Propylene/Propane Separation

Highly permselective and durable membrane materials have been sought for energy-efficient C₃ H₆ /C₃ H₈ separation. Mixed-matrix membranes (MMMs) comprising a polymer matrix and metal-organic frameworks (MOFs) are promising candidates for this application; however, rational matching of filler-matrix is challenging and their separation performances need to be further improved. Here, we propose a novel strategy of "defect engineering" in MOFs as an additional degree of freedom to design advanced MMMs. MMMs incorporated with defect-engineered MOFs exhibit exceptionally high C₃ H₆ permeability and maintained C₃ H₆ /C₃ H₈ selectivity, especially with enhanced stability under industrial mixed-gas conditions. The gas transport, sorption, and material characterizations reveal that the defect sites in MOFs provide the resulting MMMs with not only ultrafast diffusion pathways but also favorable C₃ H₆ sorption by forming complexation with unsaturated open metal sites, confirmed by in situ FT-IR studies. Most importantly, the concept is also valid for different polymer matrices and gas pairs, demonstrating its versatile potential in other fields.

Abstract P2-14-15: Breast cancer-related lymphedema: Morbidity of sentinel node biopsy

Purpose:

Sentinel lymph node biopsy (SLNB) lowers morbidity of lymphedema then axillary lymph node dissection (ALND). However, there has been concern about incidence of lymphedema after SLNB especially when the number of harvested nodes during sentinel node biopsy procedure is more than a few. In this study, we assessed lymphedema incidence and its risk factors including the number excised lymph nodes in patients who underwent SLNB.

Methods:

Between January, 2011 and April, 2012, the records of 910 consecutive patients who underwent breast surgery with axillary staging (SLNB/ALND) for breast cancer at Seoul National University Hospital were reviewed. Lymphedema was assessed by circumferential upper extremity measurements. The lymphedema was defined as &gt; 1cm for either the upper arm or the forearm. Patients with clinical records of the treatment for lymphedema in the rehabilitation clinic were regarded as having lymphedema. Univariate and multivariate analyses were performed to identify potential risk factors associated with lymphedema. Association of number of excised lymph nodes with lymphedema was analyzed by Spearman rank correlation coefficient.

Results:

At median follow-up of 69.8 months, 231 patients (25.4%) presented with lymphedema. In univariate analysis, body mass index (BMI) (P&lt;0.001), T stage (P&lt;0.001), N stage (P&lt;0.001), type of surgery (P&lt;0.001), ALND (P&lt;0.001), neoadjuvant chemotherapy (P&lt;0.001) and adjuvant chemotherapy (P=0.027) were significantly associated with lymphedema. In multivariate analysis BMI (P&lt;0.001), ALND (P&lt;0.001), neoadjuvant chemotherapy (P=0.044), and radiation therapy (P=0.046) were significantly associated with lymphedema. In patients treated with SLNB only (n=595), the incidence of lymphedema was 16.3% (n=97). In SLNB only subgroup, BMI was only significant risk factor of lymphedema. There was no correlation between number of excised lymph nodes during sentinel lymph node biopsy procedure with incidence of lymphedema (P=0.138).

Conclusion:

The risk of lymphedema is multifactorial in breast cancer surgery and adjuvant treatments. In SLNB alone patients, higher BMI was only significant factor correlated with lymphedema. Excised number of lymph nodes during sentinel biopsy procedure was not associated with lymphedema.

Citation Format: Ju YW, Jung JG, Kim KE, Kim Y, Lee E, Lee H-B, Moon H-G, Han W, Noh D-Y. Breast cancer-related lymphedema: Morbidity of sentinel node biopsy [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P2-14-15.

Abstract P4-14-09: A nationwide data on the cardiovascular protective effect of tamoxifen and aromatase inhibitor in postmenopausal women with breast cancer

A large proportion of breast cancer patients receive hormonal therapy as their adjuvant treatment options. For postmenopausal women, the initial choice for the hormonal therapy is aromatase inhibitor (AI), and tamoxifen (TM) is reserved for women experiencing severe side effects against AI or having low bone density. An important but unresolved clinical question regarding the use of AI in postmenopausal women is the safety of AI regarding the risk cardiovascular events. Studies have shown inconsistent results over the cardiovascular safety of AI and TM. In this study, we investigated the risk of developing cardiovascular and cerebrovascular events in women with breast cancer who receive hormonal therapy using AI, TM, or both.

To this end, we used the National Health Insurance Sharing Service in Korea which is provided by National Health Insurance Service. The database provides anonymized insurance data for research purposes after the approval of the review committee. In the database, we identified 47,569 women with the age older than 55 who were diagnosed with breast cancer. Patients were classified as no hormonal treatment group (n=18,807), AI group (n=19,584), TM group (n=7,081), or Switch group (n=2,097). The Switch group was defined as the women with history of both AI and TM prescriptions. During the studied period, a total of 2,032 cardiovascular or cerebrovascular events (CVE) were recorded.

Overall, the women prescribed with TM had significantly less hazard ratio for developing CVE when compared to the women who did not receive any hormonal treatment (HR 0.809 95% C.I. 0.706-0.928). However, this protective effect of tamoxifen was not observed in either AI or Switch group (HR 0.917 95% C.I. 0.833-1.010, and HR 0.856 95% C.I. 0.695-1.053, respectively). The protective effect of TM was also similar in women older than 60 (HR 0.808 95% C.I. 0.696-0.938). The cardiovascular and cerebrovascular protective effects of tamoxifen was also substantial in high risk women defined by their family history of cardiovascular diseases and the diagnosis of hypertension or diabetes.

Our results suggest that the use of TM is associated with a substantial protective effect against developing cardiovascular or cerebrovascular events in women with breast cancer. However, the protective effect was not observed for women receiving AI. Our data suggest the potential tailored approach in hormonal treatment in breast cancer patients who are at high risk of cardiovascular of cerebrovascular events.

Citation Format: Moon H-G, Choi SH, Park Y, Jung JG, Ju YW, Kim KE, Kim Y, Lee E, Lee H-B, Han W, Noh D-Y, Yoon H-J. A nationwide data on the cardiovascular protective effect of tamoxifen and aromatase inhibitor in postmenopausal women with breast cancer [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P4-14-09.

Visceral Obesity Is Associated with Gallbladder Polyps

Background/Aims

Gallbladder polyps (GBP) are a common clinical finding and may possess malignant potential. We conducted this study to determine whether visceral obesity is a risk factor for GBP.

Methods

We retrospectively reviewed records of subjects who received both ultrasonography and computed tomography with measurements of the areas of visceral adipose tissue and total adipose tissue (TAT) on the same day as health checkups.

Results

Ninety-three of 1,615 subjects (5.8%) had GBP and were compared with 186 age- and sex-matched controls. VAT (odds ratio [OR], 2.941; 95% confidence interval [CI], 1.325 to 6.529; p=0.008 for the highest quartile vs the lowest quartile) and TAT (OR, 3.568; 95% CI, 1.625 to 7.833; p=0.002 for the highest quartile vs the lowest quartile) were independent risk factors together with hypertension (OR, 2.512; 95% CI, 1.381 to 4.569; p=0.003), diabetes mellitus (OR, 2.942; 95% CI, 1.061 to 8.158; p=0.038), hepatitis B virus positivity (OR, 3.548; 95% CI, 1.295 to 9.716; p=0.014), and a higher level of total cholesterol (OR, 2.232; 95% CI, 1.043 to 4.778; p=0.039 for <200 mg/dL vs ≥240 mg/dL). Body mass index and waist circumference were not meaningful variables.

Conclusions

Visceral obesity measured by VAT and TAT was associated with GBP irrespective of body mass index or waist circumference.

Visceral adiposity is associated with an increased risk of functional dyspepsia

BACKGROUND

The relationship between visceral adiposity and the incidence of functional dyspepsia (FD) has not yet been studied. The purpose of the present study is to evaluate the association between visceral adiposity and the risk of FD.

METHODS

This is a case-control study that compares the abdominal adipose tissue area between subjects with FD and control subjects without FD, who underwent abdomen computerized tomography (CT) for health examinations in a tertiary center. Retrospectively, a telephone survey was conducted to diagnose FD using the Rome III criteria. We measured various indices of obesity including body mass index (BMI), waist circumference (WC), visceral adipose tissue (VAT) area, subcutaneous adipose tissue (SAT) area and the VAT/SAT ratio in order to evaluate the association between FD and abdominal adiposity.

KEY RESULTS

A total of 363 subjects were included in the present study. FD was diagnosed in 90 subjects (24.8%). In the univariate analysis, WC, VAT area, TAT area, VAT/SAT ratio, and the presence of erosive esophagitis were significantly higher in the FD group than in the non-FD group. In the multivariate analysis, a higher VAT area (odds ratio (OR), 3.76; 95% confidence interval (CI), 1.24-11.40; highest quartile vs lowest quartile, p = 0.019) and VAT/SAT ratio (OR, 2.35; 95% CI, 1.27-4.32; highest quartile vs lowest quartile, p = 0.006) were independently associated with a risk of FD.

CONCLUSION AND INFERENCES

Visceral adiposity as measured by the VAT area and VAT/SAT ratio is associated with an increased risk of FD.

Behavior of Small, Asymptomatic, Nonfunctioning Pancreatic Neuroendocrine Tumors (NF-PNETs)

Small nonfunctioning pancreatic neuroendocrine tumors (NF-PNETs) usually exhibit minimal or no growth over many years. However, there is a controversy regarding the optimal management of incidentally discovered, small NF-PNETs. This study aimed to gain insights into tumor behavior and potential strategies for clinical management.We retrospectively reviewed a total of 202 patients with a suspected PNET (size 2 cm or smaller) at Samsung Medical Center from January 1, 1995 to April 30, 2012. Among these patients, 72 patients were excluded and 145 patients were enrolled in our study. Patients were included if the size of the tumor was ≤2 cm without familial syndrome, radiographic evidence of local invasion or metastases.Among the 145 patients, 76 patients (52.4%) had pathologically confirmed PNETs. Eleven (14.5%) and 3 (3.9%) of these 76 patients were diagnosed with NET G2 and G3, respectively. PNETs measuring 1.5 cm or more in size had a higher probability of being classified as NET G2 or G3 compared with PNETs measuring <1.5 cm (P = 0.03). Older age (≥55 years) and a meaningful tumor growth (≥20% or ≥5 mm) were significantly associated with NET G2 or G3 (P < 0.05).Older age (≥55 years), larger tumor size (≥1.5 cm), and a meaningful tumor growth (≥20% or ≥5 mm) were associated with NET G2 or G3. Intensive follow-up could be an acceptable approach in small (especially <1.5 cm), asymptomatic, NF-PNETs.

Role of SpyGlass peroral cholangioscopy in the evaluation of indeterminate biliary lesions

BACKGROUND

Accurate diagnosis of indeterminate biliary lesions is essential for treatment planning. The currently available techniques have some limitations in evaluating indeterminate biliary lesions. SpyGlass single-operator peroral cholangioscopy system has been developed to overcome these limitations.

AIM

The aim of this retrospective study was to evaluate the diagnostic accuracy of SpyGlass visual assessment and SpyBite biopsy in patients with indeterminate biliary lesions.

METHODS

We conducted a retrospective analysis of data from 36 patients with indeterminate biliary strictures or filling defects who had inconclusive results on the cross-sectional imaging study from September 2010 to October 2013. Four patients were excluded because of the presence of a metastatic mass and an ampulla of Vater cancer.

RESULTS

Thirty-two patients (19 men, mean age 63.7 years) with indeterminate biliary lesions underwent SpyGlass cholangioscopy. The cholangioscopy procedure with SpyGlass was technically successful in all of the cases except for one case because of the intraprocedural breakage of the SpyGlass optic probe (96.8%, 31/32). The biopsy specimens from nineteen patients were obtained using SpyBite forceps. The sensitivity, specificity, and overall accuracy of SpyGlass visual assessment and SpyBite biopsy for the diagnosis of malignancy were 100% (21/21) and 64.2% (9/14), 90% (9/10) and 100% (5/5), and 96.7% (30/31) and 73.6% (14/19), respectively. Procedure-related complications were noted in three cases; postsphincterotomy bleeding in one case and mild pancreatitis in two cases.

CONCLUSIONS

SpyGlass cholangioscopy with SpyBite biopsy is highly accurate and safe for differentiating malignant lesions from benign lesions in patients with indeterminate biliary lesions.

Primary mucosa-associated lymphoid tissue lymphoma of the esophagus, manifesting as a submucosal tumor

We report a case of primary mucosa-associated lymphoid tissue (MALT) lymphoma in the esophagus that manifested as a large submucosal tumor (SMT). Primary esophageal lymphoma is very rare, occurring in less than 1% of all patients with gastrointestinal lymphoma. Only a few cases of MALT lymphoma in the esophagus have been reported in the English literature. A 53-year-old man was referred to Dongguk University Ilsan Hospital (Goyang, Korea) in July 2012 for further evaluation and treatment of an esophageal SMT. Endoscopy showed a cylindrically elongated submucosal mass with normal overlying mucosa in the mid esophagus, 25-30 cm from the incisor teeth. He underwent surgery to confirm the diagnosis. Pathologic findings showed diffuse small atypical lymphoid cells which were stained with Bcl-2, CD20, but not with CD3, CD5, CD23, Bcl-6, or cyclin D1. These cells showed a positive monoclonal band for immunoglobulin heavy chain gene rearrangement. Based on the pathological, immunohistochemical, and molecular biological features, the esophageal mass was diagnosed as extranodal marginal zone B-cell lymphoma of the MALT type.

Vegetarianism as a protective factor for reflux esophagitis: a retrospective, cross-sectional study between Buddhist priests and general population

BACKGROUND/AIMS

Several risk factors for reflux esophagitis, such as smoking, alcohol consumption, obesity, and metabolic syndrome, are recognized. But vegetarianism as a protective factor for reflux esophagitis has not been reported. The aim of this study is to elucidate the protective effect of vegetarianism for reflux esophagitis.

METHODS

This is a cross-sectional study that compared the prevalence of reflux esophagitis of 148 Buddhist priests, who are obligatory vegetarians with that of age- and sex-matched controls who underwent health checkups in a health promotion center.

RESULTS

The prevalence of reflux esophagitis was higher in the control group than in the Buddhist priest group (21.6 vs 12.2 %). Weight, body mass index, waist circumference, waist-to-hip ratio, and abdominal adipose tissue area were higher and high density lipoprotein (HDL) cholesterol and total cholesterol were lower in the Buddhist priest group. The prevalence of metabolic syndrome was higher in the Buddhist priest group than the control group (30.4 vs 17.6 %). In univariate analysis, male sex (odds ratio [OR] = 3.325; 95 % confidence interval [CI], 1.659-6.666), current smoking (OR = 3.37; 95 % CI, 1.439-7.881), alcohol consumption (OR = 2.75; 95 % CI, 1.375-5.481), waist circumference (OR = 1.99; 95 % CI, 1.062-3.739), negative for Helicobacter pylori IgG antibody (OR = 1.89; 95 % CI, 1.018-3.491) and non-vegetarianism (OR = 1.99; 95 % CI, 1.062-3.739) were associated with reflux esophagitis. According to multivariate analysis, male sex (OR = 3.44; 95 % CI, 1.698-6.970), non-vegetarianism (OR = 2.08; 95 % CI, 1.086-3.974) and negative H. pylori IgG antibody (OR = 1.96; 95 % CI, 1.039-3.712) were significantly associated with reflux esophagitis.

CONCLUSIONS

A non-vegetarian diet is associated with reflux esophagitis.

Results on preemptive or prophylactic treatment of lamivudine in HBsAg (+) renal allograft recipients: comparison with salvage treatment after hepatic dysfunction with HBV recurrence

BACKGROUND

Lamivudine has been reported to be able to stabilize liver enzyme and hepatitis B virus (HBV) replication with recurrent hepatitis that has been regarded as a frequent and major risk factor for hepatic dysfunction and chronic liver disease in renal transplant recipients. Because large number of hepatitis antigenemia patients among renal transplant patients experience recurrent hepatic dysfunction with HBV recurrence and permanent histological deterioration, preemptive or primary prophylactic use of lamivudine before transplantation may be more beneficial than a trial for the treatment of advanced hepatic dysfunction.

METHODS

We conducted a double arm study to compare the efficacy of lamivudine between the preemptive (HBV DNA positive) or prophylactic (HBV DNA negative) trial for the maintenance of stable liver function (n=10) and the trial for the salvage of advanced hepatic dysfunction developed after renal transplantation (n=6) in hepatitis B viremia carrier renal transplant recipients.

RESULTS

Hepatic dysfunction with recurrent HBV antigenemia developed in 11 of 36 (30.6%) hepatitis antigenemia patients with a mean duration of 8.4 months (range 5-19.4 months). In six patients treated with lamivudine after hepatic dysfunction from recurrent hepatitis B viremia, serum AST and ALT level normalized within 1 month and HBV-DNA disappeared in all cases. HBV-DNA, however, reappeared in three (50%) without any discontinuation of lamivudine. Liver biopsy revealed recurrent chronic active hepatitis with severe activity of fibrosis in four cases, cholestatic fibrosing hepatitis in one, and permanent cirrhotic change in one. In seven patients who had preemptive lamivudine treatment at 9, 6, 2, 2, 1, 0, 0 month before the transplantation, HBV-DNA had converted to negative with a mean follow up of 1.2 months (range 1-2 month) in all case. Three patients who had prophylactic trials with lamivudine have all remained HBV-DNA negative. The recurrence rate of HBV viremia in the preemptive or prophylactic lamivudine treated group is 10.0% (1/10), which is significantly lower than that (42.3%, 11/25) in the nonlamivudine-treated group. The re-recurrence rate of HBV viremia was significantly higher (3/6, 50.0%) in the reactive lamivudine treated group than in prophylactic or preemptive group (1/10, 10%).

CONCLUSION

Although lamivudine treatment after hepatic dysfunction can be a sound conventional treatment modality, this preliminary study may suggest that preemptive or prophylactic trial of lamivudine before hepatic dysfunction might be a more effective strategy for prevention of permanent histological deterioration and recurrence of hepatitis B viremia.