Twenty-one years of experience with resected solid pseudopapillary neoplasm: a retrospective single-institutional cohort study.

BACKGROUND: Although the incidence of solid pseudopapillary neoplasm (SPN) is <2% of the incidence of pancreatic tumor, the prevalence seems to be increasing. SPNs are mostly benign. However, they also show malignant features. This study aimed to identify the clinical outcomes of patients who underwent surgery for SPN at a single center. METHODS: Data on 217 patients with SPN who underwent surgery in Samsung Medical Center between 2000 and 2020 were retrospectively analyzed. RESULTS: Herein, the mean age of the 217 patients was 40.0 ± 12.6 years, with a female predominance (80.6%). Most patients had no comorbidity. The mean tumor size was 4.4 ± 3.1 cm. The tumor was located at the pancreatic head in 36 patients (16.6%), the body of the pancreas in 69 patients (31.8%), and the pancreatic tail in 96 patients (44.2%). Of note, 35 patients (16.1%) underwent pancreaticoduodenectomies, 148 patients (68.2%) had distal pancreatectomies, and the other patients had subtotal /total pancreatectomy (9.7%) or enucleation/mass excision (6.0%). No patient had lymph node (LN) metastasis. Moreover, 6 patients (2.8%) had a recurrence in the liver or regional LNs. The 5-year recurrence-free survival rate was 96.8%. The only factor affecting recurrence was tumor size (P = .007). CONCLUSION: Because SPN predominates in relatively young women, patients often hesitate to undergo surgery. Nevertheless, as size is the prognostic factor, early resection is recommended for a better prognosis in the case of surgically feasible, young age, and healthy patients.

Survival Comparison of Different Operation Types for Middle Bile Duct Cancer: Bile Duct Resection versus Pancreaticoduodenectomy Considering Complications and Adjuvant Treatment Effects.

BACKGROUND: Margin status is one of the most significant prognostic factors after curative surgery for middle bile duct (MBD) cancer. Bile duct resection (BDR) is commonly converted to pancreaticoduodenectomy (PD) to achieve R0 resection. Additionally, adjuvant treatment is actively performed after surgery to improve survival. However, the wider the range of surgery, the higher the chance of complications; this, in turn, makes adjuvant treatment impossible. Nevertheless, no definitive surgical strategy considers the possible complication rates and subsequent adjuvant treatment. We aimed to investigate the appropriate surgical type considering the margin status, complications, and adjuvant treatment in MBD cancer. MATERIALS AND METHODS: From 2008 to 2017, 520 patients diagnosed with MBD cancer at the Samsung Medical Center were analyzed retrospectively according to the operation type, margin status, complications, and adjuvant treatment. The R1 group was defined as having a carcinoma margin. RESULTS: The 5-year survival rate for patients who underwent R0 and R1 resection was 54.4% and 33.3%, respectively (p = 0.131). Prognostic factors affecting the overall survival were the age, preoperative CA19-9 level, T stage, and N stage, but not the operation type, margin status, complications, or adjuvant treatment. The complication rates were 11.5% and 29.8% in the BDR and PD groups, respectively (p < 0.001). We observed no significant difference in the adjuvant treatment ratio according to complications (p = 0.675). Patients with PD who underwent R0 resection and could not undergo chemotherapy because of complications reported better survival rates than those with BDR who underwent R1 resection after adjuvant treatment (p = 0.003). CONCLUSION: The survival outcome of patients with R1 margins who underwent BDR did not match those with R0 margins after PD, even after adjuvant treatment. Due to improvements in surgical techniques and the ability to resolve complications, surgical complications exert a marginal effect on survival. Therefore, surgeons should secure R0 margins to achieve the best survival outcomes.

Different Oncologic Outcomes According to Margin Status (High-Grade Dysplasia vs. Carcinoma) in Patients Who Underwent Hilar Resection for Mid-Bile Duct Cancer.

Margin positivity after hilar resection (HR) for bile duct cancer is commonly observed due to its longitudinal spread along the subepithelial plane; nevertheless, we cannot draw conclusions regarding the prognostic effects of margins with high-grade dysplasia (HGD) or carcinoma. We aimed to investigate the oncologic effect according to the margin status after HR, particularly between the R1 HGD and the R1 carcinoma. From 2008 to 2017, 149 patients diagnosed with mid-bile duct cancer in Samsung Medical Center, South Korea, were divided according to margin status after HR and retrospectively analyzed. Recurrence patterns were also analyzed between the groups. There were 126 patients with R0 margins, nine with R1 HGD, and 14 with R1 carcinoma. The mean age of the patients was 68.3 (±8.1); most patients were male. The mean age was higher in R1 carcinoma patients than in R1 HGD and R0 patients (p = 0.014). The R1 HGD and R1 carcinoma groups had more patients with a higher T-stage than R0 (p = 0.079). In univariate analysis, the prognostic factors affecting overall survival were age, T- and N-stage, CA19-9, and margin status. The survival rate of R0 was comparable to that of R1 HGD, but the survival rate of R0 was significantly better compared to R1 carcinoma (R0 vs. R1 HGD, p = 0.215, R0 vs. R1 carcinoma, p = 0.042, respectively). The recurrence pattern between the margin groups did not differ significantly (p = 0.604). Extended surgery should be considered for R1 carcinoma; however, in R1 HGD, extended operation may not be necessary, as it may achieve oncologic outcomes similar to R0 margins with HR.

Single-shot multi-channel plasmonic real-time polymerase chain reaction for multi-target point-of-care testing.

Plasmonic nucleic acid amplification tests demand high-throughput and multi-target detection of infectious diseases as well as short turnaround time and small size for point-of-care molecular diagnostics. Here, we report a multi-channel plasmonic real-time reverse-transcription polymerase chain reaction (mpRT-qPCR) assay for ultrafast and on-chip multi-target detection. The mpRT-qPCR system features two pairs of plasmonic thermocyclers for rapid nanostructure-driven amplification and microlens array fluorescence microscopes for in situ multi-color fluorescence quantification. Each channel shows a physical dimension of 32 mm, 75 mm, and 25 mm in width, length, and thickness. The ultrathin microscopes simultaneously capture four different fluorescence images from two PCR chambers of a single cartridge at a single shot exposure per PCR cycle of four different excitation light sources. The experimental results demonstrate a single assay result of high-throughput amplification and multi-target quantification for RNA-dependent RNA polymerase, nucleocapsid, and human ribonuclease P genes in SARS-CoV-2 RNA detection. The mpRT-PCR increases the number of tests four times over the single RT-PCR and exhibits a short detection time of 15 min for the four RT-PCR reactions. This point-of-care molecular diagnostic platform can reduce false negative results in clinical applications of virus detection and decentralize healthcare facilities with limited infrastructure.

Prognosis of pancreaticoduodenectomy in octogenarians for pancreatic ductal adenocarcinoma with propensity score matched analysis.

BACKGROUND: This retrospective study investigates factors affecting surgical and oncological outcome after performing pancreaticoduodenectomy in octogenarian patients diagnosed with pancreatic ductal adenocarcinoma. METHODS: From January 2009 to December 2018, patients who underwent pancreaticoduodenectomy for pancreatic ductal adenocarcinoma were included. Data were analysed by comparing clinicopathological characteristics, complications, survival, recurrence, adjuvant treatment between octogenarians and the younger group. Propensity score matched analysis was performed due to the small size of the octogenarian group. RESULTS: A total of 666 patients were included in this study and 24 (3.6%) were included in the octogenarian group. Short term complication rates (P = 0.119) and hospital stay (P = 0.839) did not differ between two groups. Overall survival between the two groups showed significant difference (<80 median 25 months versus ≥80 median 13 months, P = 0.045). However, after propensity score matched analysis, the two groups did not differ in overall survival (<80 median 18 months versus ≥80 median survival 16 months, P = 0.565) or disease-free survival (P = 0.471). Among the octogenarians, six patients survived longer than 24 months even without satisfying all favourable prognostic factors. CONCLUSION: Considering the general condition of octogenarians diagnosed with pancreatic ductal adenocarcinoma, select patients should be treated more aggressively for the best chance of receiving curative treatment.

Survival Benefit after Shifting from Upfront Surgery to Neoadjuvant Treatment in Borderline Resectable Pancreatic Cancer.

According to the 2016 National Comprehensive Cancer Network (NCCN) guidelines, patients with borderline resectable pancreatic cancer (BRPC) should receive chemotherapy as the first-line treatment. This study examined the real-world survival benefits of modifying BRPC treatment guidelines. Patients treated for BRPC at a single institution from 2013 to 2015 (pre-guideline group) and 2017 to 2019 (post-guideline group) were retrospectively reviewed. According to the treatment method used, patients were classified into upfront surgery (US), surgery after neoadjuvant treatment (NAT), and chemotherapy only (CO) groups. Overall survival (OS) was compared according to period and treatment type. Factors associated with OS were analyzed using a Cox regression model. Among the 165 patients, 63 were in the pre-guideline group and 102 patients were in the post-guideline group. The median OS was significantly improved in the post-guideline group compared to the pre-guideline group (29 vs. 13 months, p < 0.001). According to the treatment method, the median OS of the NAT group was significantly longer than that of the US and CO groups (40 vs. 16 vs. 15 months, respectively, p < 0.001). In multivariate analysis, tumor size, differentiation, NAT, and perineural invasion were significant prognostic factors. NAT is an important treatment option for BRPC and increased patient survival in the real world.

Regulation of Survival Motor Neuron Gene Expression by Calcium Signaling.

Spinal muscular atrophy (SMA) is caused by homozygous survival of motor neurons 1 (SMN1) gene deletion, leaving a duplicate gene, SMN2, as the sole source of SMN protein. However, a defect in SMN2 splicing, involving exon 7 skipping, results in a low level of functional SMN protein. Therefore, the upregulation of SMN protein expression from the SMN2 gene is generally considered to be one of the best therapeutic strategies to treat SMA. Most of the SMA drug discovery is based on synthetic compounds, and very few natural compounds have been explored thus far. Here, we performed an unbiased mechanism-independent and image-based screen of a library of microbial metabolites in SMA fibroblasts using an SMN-specific immunoassay. In doing so, we identified brefeldin A (BFA), a well-known inhibitor of ER-Golgi protein trafficking, as a strong inducer of SMN protein. The profound increase in SMN protein was attributed to, in part, the rescue of the SMN2 pre-mRNA splicing defect. Intriguingly, BFA increased the intracellular calcium concentration, and the BFA-induced exon 7 inclusion of SMN2 splicing, was abrogated by the depletion of intracellular calcium and by the pharmacological inhibition of calcium/calmodulin-dependent kinases (CaMKs). Moreover, BFA considerably reduced the expression of Tra2-ß and SRSF9 proteins in SMA fibroblasts and enhanced the binding of PSF and hnRNP M to an exonic splicing enhancer (ESE) of exon 7. Together, our results demonstrate a significant role for calcium and its signaling on the regulation of SMN splicing, probably through modulating the expression/activity of splicing factors.

Concerns and breakthroughs of combining ionic liquids with microwave irradiation for the synthesis of Ru nanoparticles via decarbonylation.

HYPOTHESIS: Combination of microwave irradiation (MWI) and ionic liquids (IL) is widely used for the synthesis of nanoparticles (NP) via decarbonylation of zero-valent metal carbonyl precursors. However, we carefully raise a question as to whether this combination is always beneficial. Upon MWI, highly-absorbing materials such as ILs would be subject to local intense heating, likely resulting in the occurrence of localized chemical decomposition. The decomposition is expected to influence the growth mechanism of NPs due to changes in the electrostatic and steric effects. If the assumption is valid, it should be possible to decompose IL and destabilize the NPs by modifying the amplitude of the incident microwaves. In other words, it should also be possible to control the particle aggregation by circumventing the decomposition of the IL. EXPERIMENTS: A series of comparative studies were conducted using a model system (i.e. [BMIm][BF4] and Ru3(CO)12). Variables were systematically controlled. After MWI, the decrease in colloidal stability of NPs was identified. FINDINGS: In the formation of Ru NPs via decarbonylation, the association between incident microwave intensity, chemical decomposition of IL, and initiation of particle aggregation has been demonstrated. Conditions that can accelerate or alleviate the decomposition and the aggregation are also corroborated.

Improvement of spinal muscular atrophy via correction of the SMN2 splicing defect by Brucea javanica (L.) Merr. extract and Bruceine D.

BACKGROUND: Spinal muscular atrophy (SMA) is a rare neuromuscular disease and a leading genetic cause of infant mortality. SMA is caused primarily by the deletion of the survival motor neuron 1 (SMN1) gene, which leaves the duplicate gene SMN2 as the sole source of SMN protein. The splicing defect (exon 7 skipping) of SMN2 leads to an insufficient amount of SMN protein. Therefore, correcting this SMN2 splicing defect is considered to be a promising approach for the treatment of SMA. PURPOSE: This study aimed to identify active compounds and extracts from plant resources to rescue SMA phenotypes through the correction of SMN2 splicing. STUDY DESIGN: Of available plant resources, candidates with SMA-related traditional medicine information were selected for screening using a robust luciferase-based SMN2 splicing reporter. Primary hits were further evaluated for their ability to correct the splicing defect and resultant increase of SMN activity in SMA patient-derived fibroblasts. Confirmed hits were finally tested to determine the beneficial effects on the severe Δ7 SMA mouse. METHODS: SMN2 splicing was analyzed using a luciferase-based SMN2 splicing reporter and subsequent RT-PCR of SMN2 mRNAs. SMA phenotypes were evaluated by the survival, body weights, and righting reflex of Δ7 SMA mice. RESULTS: In a screen of 492 selected plant extracts, we found that Brucea javanica extract and its major constituent Bruceine D have SMN2 splicing-correcting activity. Their ability to correct the splicing defect and the resulting increased SMN activity were further confirmed in SMA fibroblasts. Importantly, both B. javanica and Bruceine D noticeably improved the phenotypic defects, especially muscle function, in SMA mice. Reduced expression of heterogeneous nuclear ribonucleoprotein A1 (hnRNP A1) contributed to the correction of splicing by B. javanica. CONCLUSION: Our work revealed that B. javanica and Bruceine D correct the SMN2 splicing defect and improve the symptoms of SMA in mice. These resources will provide another possibility for development of a plant-derived SMA drug candidate.

Tribological and Electrical Properties of Diamond-Like Carbon Films Deposited by Filtered Vacuum Arc Method for Medical Guidewire Application.

A good medical guidewires are used to introduce stents, catheters, and other medical devices inside the human body. In this study, diamond-like carbon (DLC) film was proposed to solve the poor adhesion problem of guidewire and to improve the tribological performance of guidewire. DLC films were fabricated on Si substrate by using FVA (Filtered Vacuum Arc) method. In this work, the tribological, structural, and electrical properties of the fabricated DLC films with various arc currents were experimentally investigated. All DLC films showed smooth and uniform surface with increasing applied arc current. The rms surface roughness was increased and the value of contact angle on the film surface was decreased with increasing arc current. The hardness and elastic modulus of DLC films were improved, and the resistivity value of DLC films were decreased with increasing arc current. These results are associated with ion bombardment effects by the applied arc current and bias voltage.

Inactivation of human DGAT2 by oxidative stress on cysteine residues.

Diacylglycerol acyltransferases (DGATs) have a crucial role in the biosynthesis of triacylglycerol (TG), the major storage form of metabolic energy in eukaryotic organisms. Even though DGAT2, one of two distinct DGATs, has a vital role in TG biosynthesis, little is known about the regulation of DGAT2 activity. In this study, we examined the role of cysteine and its oxidation in the enzymatic activity of human DGAT2 in vitro. Human DGAT2 activity was considerably inhibited not only by thiol-modifying reagents (NEM and IA) but also by ROS-related chemicals (H2O2 and ß-lapachone), while human DGAT1 and GPAT1 were little affected. Particularly, ROS-related chemicals concomitantly induced intermolecular disulfide crosslinking of human DGAT2. Both the oxidative inactivation and disulfide crosslinking were almost completely reversed by the treatment with DTT, a disulfide-reducing agent. These results clearly demonstrated the significant role of ROS-induced intermolecular crosslinking in the inactivation of human DGAT2 and also suggested DGAT2 as a redox-sensitive regulator in TG biosynthesis.

Development of Germano-Silicate Optical Fiber Incorporated with Germanium Nanoparticles and Its Optical Characteristics.

The germano-silicate optical fiber incorporated with Ge nanoparticles with enhanced optical nonlinearity was developed by using modified chemical vapor deposition and drawing processes. A broad photoluminescence band obtained by pumping with the 404 nm superluminescent diode was found to appear from 540 nm to 1,000 nm. The non-resonant nonlinear refractive index, n2, of the fiber measured by the continuous wave self-phase modulation method was 4.95 x 10(-20) m2/W due to the incorporated Ge nanoparticles in the fiber core. The enhancement of the non-resonant optical non-linearity may be due to the creation of the NBOs and other defects from the incorporated Ge-NPs in the fiber core.

Antiviral activity of micafungin against enterovirus 71.

BACKGROUND: Enterovirus 71 (EV71) is a major causative agent of hand-foot-mouth disease (HFMD) and also causes severe neurological complications, leading to fatality in young children. However, no effective therapy is currently available for the treatment of this infection. METHODS: We identified small-molecule inhibitors of EV71 from a screen of 968 Food and Drug Administration (FDA)-approved drugs, with which clinical application for EV71-associated diseases would be more feasible, using EV71 subgenomic replicon system. Primary hits were extensively evaluated for their antiviral activities in EV71-infected cells. RESULTS: We identified micafungin, an echinocandin antifungal drug, as a novel inhibitor of EV71. Micafungin potently inhibits the proliferation of EV71 as well as the replication of EV71 replicon in cells with a low micromolar IC50 (~5 µM). The strong antiviral effect of micafungin on EV71 replicon and the result from time-of-addition experiment demonstrated a targeting of micafungin on virion-independent intracellular process(es) during EV71 infection. Moreover, an extensive analysis excluded the involvement of 2C and 3A proteins, IRES-dependent translation, and also that of polyprotein processing in the antiviral effect of micafungin. CONCLUSIONS: Our research revealed a new indication of micafungin as an effective inhibitor of EV71, which is the first case reporting antiviral activity of micafungin, an antifungal drug.

Effective supercontinuum generation by using highly nonlinear dispersion-shifted fiber incorporated with Si nanocrystals.

The dispersion-shifted fiber (DSF) incorporated with Si nanocrystals (Si-NCs) having highly nonlinear optical property was fabricated to investigate the effective supercontinuum generation characteristics by using the MCVD process and the drawing process. Optical nonlinearity was enhanced by incorporating Si nanocrystals in the core of the fiber and the refractive index profile of a dispersion-shifted fiber was employed to match its zero-dispersion wavelength to that of the commercially available pumping source for generating effective supercontinuum. The non-resonant nonlinear refractive index, n2, of the Si-NCs doped DSF measured by the cw-SPM method was measured to be 7.03 x 10(-20) [m2/W] and the coefficient of non-resonant nonlinearity, gamma, was 7.14 [W(-1) km(-1)]. To examine supercontinuum generation of the Si-NCs doped DSF, the femtosecond fiber laser with the pulse width of 150 fs (at 1560 nm) was launched into the fiber core. The output spectrum of the Si-NCs doped DSF was found to broaden from 1300 nm to wavelength well beyond 1700 nm, which can be attributed to the enhanced optical nonlinearity by Si-NCs embedded in the fiber core. The short wavelength of the supercontinuum spectrum in the Si-NCs doped DSF showed shift from 1352 nm to 1220 nm for the fiber length of 2.5 m and 200 m, respectively.

Preparation of Water-Repellent Glass by Sol-Gel Process Using Perfluoroalkylsilane and Tetraethoxysilane.

Coating films on glass substrate were prepared by sol-gel process using alkoxide solutions containing perfluoroalkylsilane (PFAS) and tetraethoxysilane (TEOS). The physical properties of the coating films were characterized by SEM, FT-IR, and XRD. And their surface properties were investigated by measuring contact angles and atomic compositions. Transparent coating films with smooth surface and uniform thickness could be obtained. The contact angles of the coating films for water and methylene iodide are extremely high, at 118 degrees and 97 degrees, respectively, and their surface free energies are about 9.7 dyn/cm. It was found that the water-repellent glass prepared is very hydrophobic and exhibits excellent water-repellency. Hydrophobic perfluoroalkyl groups are preferentially enriched to the outermost layer at the coating film-air interface, and two layers probably exist in the coating film. The upper layer oriented toward the air is composed of mainly perfluoroalkyl groups originating from PFAS, and the lower layer is composed of mainly -OSiO- groups originating from TEOS. The heat treatment after drying step cannot influence the surface enrichment of the perfluoroalkyl group. The hydrolysis reaction should be more completely done before the dip coating step to obtain lower surface free energy. The burning temperature should be less than 300 degrees C because the perfluoroalkyl group begins to decompose from this temperature. Copyright 2001 Academic Press.