Screening and characterisation of CdTe/CdS quantum dot-binding peptides for material surface functionalisation

Quantum dots (QDs) are promising nanomaterials due to their unique photophysical properties. For them to be useful in biological applications, the particle surface generally needs to be conjugated to biological molecules, such as antibodies. In this study, we screened CdTe/CdS QD-binding peptides from a phage display library as linkers for simple and bio-friendly QD modification. Among five QD-binding peptide candidates, a series of truncated peptides designed from two high-affinity peptides were subjected to an array-based binding assay with QDs to assess their functional core sequences and characteristics. Linking these isolated, shortened peptides (PWSLNR and SGVYK) with an antibody-binding peptide (NKFRGKYK) created dual-functional peptides that are capable of QD surface functionalisation by antibodies. Consequently, the dual-functional peptides could mediate anti-CD9 antibody functionalisation onto CdTe/CdS QD surface; CD9 protein imaging of cancer cells was also demonstrated. Our proposed peptides offer an effective vehicle for QD surface functionalisation in biological applications

Enhanced Tubulation of Liposome Containing Cardiolipin by MamY Protein from Magnetotactic Bacteria

Lipid tubules are of particular interest for many potential applications in nanotechnology. Among various lipid tubule fabrication techniques, the morphological regulation of membrane structure by proteins mimicking biological processes may provide the chances to form lipid tubes with highly tuned structures. Magnetotactic bacteria synthesize magnetosomes (a unique prokaryotic organelle comprising a magnetite crystal within a lipid envelope). MamY protein is previously identified as the magnetosome protein responsible for magnetosome vesicle formation and stabilization. Furthermore, MamY is shown in vitro liposome tubulation activity. In this study, the interaction of MamY and phospholipids is investigated by using a lipids-immobilized membrane strip and a peptide array. Here, the binding of MamY to the anionic phospholipid, cardiolipin, is found and enhanced liposome tubulation efficiency. The authors propose the interaction is responsible for recruiting and locating cardiolipin to elongate liposome in vitro. The authors also suggest a similar mechanism for the invagination site in magnetosomes vesicle formation, where the lipid itself contributes further to increasing the curvature. These findings are highly important to develop an effective biomimetic synthesis technique of lipid tubules and to elucidate the unique prokaryotic organelle formation in magnetotactic bacteria

Outcomes of Microscopic Residual Tumor after Curative-Intent Surgery in Adenocarcinoma of Esophagogastric Junction

Objective: Radical surgery is the mainstay treatment for adenocarcinoma of the esophagogastric junction. The presence of microscopic residual tumor tissue after curative-intent surgery is associated with recurrence. This study compared the outcomes of patients with microscopic residual tumor (Residual+ group) and those without microscopic residual tumor (Residual- group). Material and Methods: We retrospectively reviewed the medical records of 71 patients with adenocarcinomas of the esophagogastric junction who underwent curative-intent surgery between January 2005 and August 2018. We evaluated the clinical and pathological characteristics and compared recurrences, rates and patterns, between groups. Five-year overall survival (OS) and 3-year disease-free survival (DFS) were analyzed by Kaplan-Meier analysis. Results: Nineteen (26.8%) patients had microscopic residual tumors, consisting of 8 (11.3%) with positive resection margins, 10 (14.0%) with malignant cells from peritoneal washing fluid cytology, and 1 (1.4%) with both. The median OS in the Residual- group was significantly better than that in the Residual+ group (31.3 vs 11.9 months, P = 0.003). The Residual- group had better 5-year OS (26.2% vs 11.9%, P = 0.015) and 3-year DFS (24.4% vs 9.8%, P = 0.003) than the Residual+ group. During follow-up period, 48% of the patients in the Residual+ group experienced recurrent disease, with a median follow-up time at 7.7 months. Distant metastasis was the most common site of recurrence. Conclusion: Microscopic residual tumor after resection is associated with poorer survival outcomes and higher recurrence rates. Curative surgery should aim to achieve R0 resection in all patients with resectable adenocarcinomas of the esophagogastric junction

Changes in Physical Components after Gastrectomy for Adenocarcinoma of Stomach and Esophagogastric Junction

Objective: Enhanced Recovery After Surgery (ERAS) is a multidisciplinary approach that aims to optimize perioperative management, promote postoperative recovery, reduce postoperative complications, and improve long-term survival. The current study aimed to evaluate and compare the postoperative physical activity after gastrectomy between patients who underwent upper gastrointestinal surgery according to ERAS and those who underwent surgery based on the conventional care (CC) protocol. Materials and Methods: This prospective and retrospective review enrolled 60 patients (n = 31, ERAS group; n = 29, CC protocol group) diagnosed with adenocarcinoma of the stomach and esophagogastric junction who underwent curative surgical resection. Physical outcomes, including body weight, body mass index, body fat percentage, basal metabolic rate, muscle mass, gait speed, and handgrip strength at the preoperative and immediate postoperative periods and at 1, 3, and 6 months postoperatively, were comparedbetween the ERAS and CC protocol groups. Results: One month after surgery, the ERAS group had a lower percentage of body weight loss than the CC protocol group. There was no significant difference in terms of muscle mass loss between the two groups. The hand grip strength of the ERAS group increased after surgery. Further, at 1 month postoperatively, the gait speed of patients who underwent total gastrectomy in the ERAS group was significantly higher than that of patients in the CC protocol group. Conclusion: ERAS for gastrectomy was associated with a lower percentage of weight loss and a trend toward physical activity enhancement in the early postoperative period

Aerosol protection using modified N95 respirator during upper gastrointestinal endoscopy: a randomized controlled trial

Background/Aims The coronavirus disease 2019 pandemic has affected the worldwide practice of upper gastrointestinal endoscopy. Here we designed a modified N95 respirator with a channel for endoscope insertion and evaluated its efficacy in upper gastrointestinal endoscopy. Methods Thirty patients scheduled for upper gastrointestinal endoscopy were randomized into the modified N95 (n=15) or control (n=15) group. The mask was placed on the patient after anesthesia administration and particles were counted every minute before (baseline) and during the procedure by a TSI AeroTrak particle counter (9306-04; TSI Inc.) and categorized by size (0.3, 0.5, 1, 3, 5, and 10 µm). Differences in particle counts between time points were recorded. Results During the procedure, the modified N95 group displayed significantly smaller overall particle sizes than the control group (median [interquartile range], 231 [54–385] vs. 579 [213–1,379]×103/m3; p=0.056). However, the intervention group had a significant decrease in 0.3-µm particles (68 [–25–185] vs. 242 [72–588]×103/m3; p=0.045). No adverse events occurred in either group. The device did not cause any inconvenience to the endoscopists or patients. Conclusions This modified N95 respirator reduced the number of particles, especially 0.3-µm particles, generated during upper gastrointestinal endoscopy

Surgical Outcomes of Bariatric Surgery in Siriraj Hospital for the First 100 Morbidly Obese Patients Treated

Objective: Bariatric surgery is considered the most effective treatment for morbid obesity, and is increasingly performed in Thailand and globally. We aimed to establish the outcomes of bariatric surgery performed at Siriraj Hospital, Bangkok. Materials and Methods: This was a retrospective study of patients who underwent bariatric surgery between January 2012 and June 2016. Results: The records of the first 100 patients who underwent bariatric surgery were reviewed, comprising 58 patients who underwent laparoscopic sleeve gastrectomy (LSG) and 42 patients who underwent laparoscopic Roux-en-Y gastric bypass (LRYGB). The median patient age, preoperative body weight, and BMI were 36 years old, 129 kg, and 46.3 kg/m2. All the procedures were performed by a laparoscopic approach. The median operative times for LSG and LRYGB were 156 [85-435] and 265 [180-435] minutes. The median hospital stay was 3 days [3-14]. The major complication rate was 4%. There was no mortality in the 30-day postoperative period. The mean %excess weight loss (%EWL) of LSG was 56.8 ± 19.8%, 59.9 ± 21.7%, and 55.1 ± 21.3%, at 1, 2, and 3 years after surgery. The mean %EWL of LRYGB was 67 ± 18.3%, 66.2 ± 21.4%, and 63.6 ± 19.9%, at 1, 2, and 3 years after surgery. In the patients with type-II diabetes mellitus, 67% had complete diabetic remission at 1 year. The median FBS dropped from 127 to 99 mg/dL (p < 0.001) and HbA1c from 6.6% to 5.5% (p < 0.001). The remission rates of hypertension and dyslipidemia were 58% and 73%. Conclusion: The bariatric procedures are safe with a low complication rate. The procedures also provide good outcomes in postoperative weight loss and comorbidity resolution

Screening of EWI-2-Derived Peptides for Targeting Tetraspanin CD81 and Their Effect on Cancer Cell Migration

CD81, a transmembrane protein belonging to the tetraspanin family, has recently been suggested as a therapeutic target for cancers. Here, we screened peptides that bind to the tetraspanin CD81 protein, and evaluated their inhibitory activity in cancer cell migration. To screen for CD81-binding peptides (CD81-BP), a peptide array membrane was prepared from the amino acid sequence of the EWI-2 protein, a major partner of CD81, before binding to fluorescently labeled CD81. As a result, four candidate CD81-BPs were identified and characterized. In particular, the CFMKRLRK peptide (called P152 in this study) was found to be the best candidate that preferentially binds to the extracellular loop of CD81, with an estimated dissociation constant of 0.91 &micro;M. Since CD81 was reported to promote cancer cell migration, an initial step in metastasis, the Boyden chamber assay, was next performed to assess the effect of CD81-BP candidates on the migration of MDA-MB-231 human breast cancer cells. Interestingly, our result indicated that P152 could suppress MDA-MB-231 cell migration at the level comparable to that of an anti-human CD81 antibody (5A6). Thus, we propose these CD81-BPs with the anti-migration property against cancer cells for the development of novel therapeutic strategies

Spatial Transcriptomic Profiling of Tetraspanins in Stage 4 Colon Cancer from Primary Tumor and Liver Metastasis

Stage 4 colon cancer (CC) presents a significant global health challenge due to its poor prognosis and limited treatment options. Tetraspanins, the transmembrane proteins involved in crucial cancer processes, have recently gained attention as diagnostic markers and therapeutic targets. However, their spatial expression and potential roles in stage 4 CC tissues remain unknown. Using the GeoMx digital spatial profiler, we profiled all 33 human tetraspanin genes in 48 areas within stage 4 CC tissues, segmented into immune, fibroblast, and tumor compartments. Our results unveiled diverse gene expression patterns across different primary tumor sub-regions. CD53 exhibited distinct overexpression in the immune compartment, hinting at a potential role in immune modulation. TSPAN9 was specifically overexpressed in the fibroblast compartment, suggesting involvement in tumor invasion and metastasis. CD9, CD151, TSPAN1, TSPAN3, TSPAN8, and TSPAN13 displayed specific overexpression in the tumor compartment, indicating potential roles in tumor growth. Furthermore, our differential analysis revealed significant spatial changes in tetraspanin expression between patient-matched stage 4 primary CC and metastatic liver tissues. These findings provide spatially resolved insights into the expression and potential roles of tetraspanins in stage 4 CC progression, proposing their utility as diagnostic markers and therapeutic targets. Understanding this landscape is beneficial for tailoring therapeutic strategies to specific sub-tumor regions in the context of stage 4 CC and liver metastasis