Revealing platelet-related subtypes and prognostic signature in pancreatic adenocarcinoma.

BACKGROUND: Pancreatic adenocarcinoma (PDAC) is a malignant tumor with high heterogeneity and poor prognosis. In this study, we sought to identify the value of platelet-related genes in prognosis and heterogeneity of PDAC through multiple transcriptomic methods. METHODS: Based on datasets from Gene Expression Omnibus and The Cancer Genome Atlas (TCGA), platelet-related genes were screened out, and the TCGA cohort (n = 171) was identified into two subtypes by unsupervised clustering. The platelet-related risk score model (PLRScore) was constructed by univariate Cox and LASSO regression, and the predictive ability was evaluated by Kaplan-Meier test and time-dependent receiver operating characteristic (ROC) curves. The results were validated in two other external validation sets, ICGC-CA (n = 140) and GSE62452 (n = 66). Furthermore, predictive nomogram containing clinical characteristics and PLRScore was established. In addition, we determined the possible correlation between PLRScore and immune infiltration and response of immunotherapy. Finally, we analyzed the heterogeneity of our signature in various types of cells using single-cell analysis. RESULTS: Platelet-related subtypes that have significant difference of overall survival and immune states (p < 0.05) were identified. PLRScore model based on four-gene signature (CEP55, LAMA3, CA12, SCN8A) was constructed to predict patient prognosis. The AUCs of training cohort were 0.697, 0.687 and 0.675 for 1-, 3-and 5-year, respectively. Further evaluation of the validation cohorts yielded similar results. In addition, PLRScore was associated with immune cell infiltration and immune checkpoint expression, and had promising ability to predict response to immunotherapy of PDAC. CONCLUSIONS: In this study, the platelet-related subtypes were identified and the four-gene signature was constructed and validated. It may provide new insights into the therapeutic decision-making and molecular targets of PDAC.

Fish isotopic niches associated with environmental indicators and human disturbance along a disturbed large subtropical river in China.

Stable isotopes are increasingly used to detect and understand the impacts of environmental changes on riverine ecological properties. The δ13C and δ15N signatures of fish with different feeding habits were measured in a large subtropical river to evaluate how fish isotopic niches respond to environmental gradients and human disturbance. From basal resources to fish consumers, the high values of epilithic periphyton (biofilm) δ13C and suspended particulate organic matter δ15N concurrently determined the niche ranges and space (e.g., convex hull area) of fish communities. Along a longitudinal gradient (except in the industrial zone), the number of fish trophic guilds identified by Bayesian ellipses continuously increased; meanwhile, higher trophic diversity and less redundancy were observed near the lower reaches and estuary. Variance inflation factors were estimated to detect the multicollinearity of 40 environmental variables, 14 of which were selected as indicators. Relative importance (RI) analysis was used to evaluate the explanatory power of these indicators for the spatial variation in isotopic niche metrics; the results showed that riffle habitat area, water nitrate concentration, gravel-cobble substrate, and riparian buffer width were the 4 key environmental indicators (average RI > 12%) that determined the longitudinal pattern of fish isotopic niches. These findings suggested that community-level δ13C signatures are more responsive to changes in habitats (e.g., riffle) and substrates (e.g., gravel-cobble) supporting the productivity of autochthonous diatoms while δ15N signatures respond to water quality altered by nitrogen pollution from manure-fertilized farming and poultry livestock effluent. Furthermore, δ15N may be more robust and interpretable than δ13C as an isotopic indicator of ecosystem change in rivers exposed to multiple or complex anthropogenic stressors.

Total Arterial Off-Pump Coronary Artery Bypass Grafting: A 10-Year Experience.

BACKGROUND: Arterial grafts had better mid-term and long-term patency than saphenous vein grafts in coronary artery bypass grafting (CABG). We summarized our experience with total arterial off-pump coronary artery bypass grafting (OPCAB) and assessed the early clinical results, surgical complications, and follow-up. METHODS: From January 2007 to May 2017, 508 coronary artery disease patients undergoing total arterial OPCAB were enrolled. Clinical features, approaches, outcomes of surgical treatments, and follow-up data of these patients were studied retrospectively. A total of 122 patients underwent single left internal mammary artery (IMA)-left anterior descending artery grafts, whereas the other 386 patients underwent multiple vessel grafts. RESULTS: The average distal anastomosis was 2.34 ± 0.97 (range: 1-4). All the patients were discharged from hospital except one died. A total of 457 (90.32%) patients were followed up. In the 4-, 7-, and 10-year follow-up groups, the rate of death from any cause was 1.19%, 6.47%, and 10.67%; rate of cardiac death was 0.60%, 2.88%, and 3.33%; rate of repeat revascularization was 0.00%, 3.60%, and 8.67%; rate of ischemic symptoms was 1.79%, 7.91%, and 11.33%; and incidence of stroke was 2.38%, 4.32%, and 6.67%, respectively. Poor medication adherence was observed in 9.38% of the follow-up population. CONCLUSIONS: Total arterial OPCAB with bilateral IMA, radial artery, and right gastroepiploic artery grafting yielded satisfactory early and midterm outcomes in this patient group, without a significant increase in early mortality or morbidity. Moreover, the long-term outcomes are also positive.

Effects of targeted CD97 immune epitopes small interference RNA on cellular biological behaviors in MDA-MB231 malignant breast cancer cell line.

Two CD97 immune epitopes, CD97EGF (epidermal growth factor domain) and CD97Stalk (stalk domain), have different distribution patterns in malignant epidermal tumors. However, little is known about the effect of CD97EGF and CD97Stalk immune epitopes in breast cancer metastasis. To explore the effects on cell proliferation, infiltration, apoptosis, and the cell cycle, we used small interfering RNA (siRNA) against CD97EGF and CD97Stalk immune epitopes to knock down CD97 in MDA-MB231 breast cancer cells. Compared with controls, CD97 knockdown caused decreased cell growth, proliferation, migration, infiltration, and altered distribution of the percentage of cells in G0/G1 and S phase. We suggest that the potential mechanism of CD97EGF and CD97Stalk immune epitopes on the biological behaviors of MDA-MB231 breast cancer cells may be related to the altered number of N-terminal glycosylation sites, which influence the stability and signaling intensity of CD97 heterodimers.

Effects of pulsed electromagnetic fields on histomorphometry and osteocalcin in disuse osteoporosis rats.

OBJECTIVE: Bone histomorphometry and the concentration of the serum osteocalcin expression were observed in disuse osteoporosis (DOP) rats in order to explore the mechanism of pulsed electromagnetic fields in treating DOP. METHODS: Female SD rats, weighing 250 ∼ 280 g, were randomly divided into 4 groups: a control group and three experimental groups. The right hindlimbs of all the rats were immobilized by tibia-tail fixation, except for those in the INT group. The ALN group rats were given an alendronate sodium (1 mg kg-1 d-1) treatment, and the rats in the PEMF group received PEMF irradiation. Bone histomorphometry and the concentration of serum osteocalcin expression were detected in 2, 4, 8, and 12 weeks. RESULTS: Four weeks after modeling, as compared with the DOP group, the %Tb-Ar and Tb-N in the ALN group were increased, and the difference was significant (P< 0.05 or P< 0.01). At 8 weeks, as compared with the DOP group, the %Tb-Ar and Tb-N in the ALN group and the PEMF group both increased, and there was a significant difference (P< 0.05 or P< 0.01). At 12 weeks, as compared with the DOP group, the BGP serum concentration of the ALN group was reduced, and there was a statistical difference (P< 0.05). CONCLUSION: Pulse electromagnetic field with drug can prevent disuse osteoporosis by changing the bone microstructure. In the long run, PEMF improves the mechanical performance of biological structures better than alendronate sodium does. PEMF may influence the process of bone remodeling by promoting the level of osteocalcin.

Occurrence, profiles, and ecological risks of polybrominated diphenyl ethers in mangrove sediments of Shantou, China.

Surface sediments were collected from three mangrove wetlands (Yifeng Xi, Shuanghan, and Su'ai Wan) in Shantou coastal zone of South China to investigate spatial distributions of polybrominated diphenyl ethers (PBDEs). The results demonstrate that PBDEs were detected in all the samples, indicating their widespread occurrence in coastal sediments of the studied area. Σ9PBDEs (defined as the sum of nine targeted PBDE congeners except BDE-209) and BDE-209 are in the range of 2.3 to 11.5 and 16.7 to 58.2 ng/g, respectively. BDE-209 is the dominant PBDE congener in all sediment samples. The sediment concentrations of ∑9PBDEs and BDE-209 among the three wetlands decrease in the order of Su'ai Wan > Shuanghan > Yifeng Xi. The concentrations of ∑9PBDEs are higher in mangrove sediments than in mudflats, but no obvious regularity can be found on the correlation between mangrove species and PBDE levels in sediments. The contents of total organic carbon are moderately correlated with BDE-209 concentrations in sediments but not with ∑9PBDE concentrations. The samples collected from different locations show slightly different composition profiles except BDE-209, with BDE-100 and BDE-47 being the pre-dominated congeners. The mudflats exhibit higher abundances of tri- to hexa-substituted congeners than the mangrove sediments. Ecological risk assessment demonstrates that the surface sediments from Shantou may pose a potential ecological risk of exposure to sediment-dwelling organisms.

Clinical treatment of gastrinoma: A case report and review of the literature.

Gastrinoma is a gastrin-secreting tumor that is associated with Zollinger-Ellison syndrome. The majority of cases occur in the pancreas, followed by the duodenum. Early diagnosis is difficult due to the relative rarity of the tumor and the lack of specific symptoms. In the current study, a 68-year-old female patient presented at the Second Affiliated Hospital, Zhejiang University (Hangzhou, China) due to intermittent abdominal pain and watery diarrhea. The patient was treated by surgical resection and was pathologically diagnosed with a well-differentiated pancreatic neuroendocrine tumor (gastrinoma; grade 1). No evidence of recurrence was observed during 1 year of follow-up. Furthermore, a review of the Chinese literature was performed, which analyzed an additional 17 published cases of gastrinoma. The tumor size ranged between 0.5×0.5 cm and 7.5×6.3×5.1 cm. The pancreas was the most common site of occurrence, accounting for 72% (13/18) of cases, followed by the duodenum (28%; 5/18). The most common initial symptom was abdominal pain (89%; 16/18), followed by diarrhea (56%; 10/18). In 18 cases, including the present case and 17 previous cases, the level of gastrin ranged between 137 and 1,550 pg/ml (normal range, 5-100 pg/ml). Of the 17 previous cases, 11 patients underwent surgery and 6 patients received conservative therapy due to metastasis or patient choice. Overall, gastrinoma remains a rare disease. Complete removal of the lesion is the standard curative treatment and conservative treatment is only recommended for patients unsuitable for surgery or for those with widespread metastasis.

3D Printout Models vs. 3D-Rendered Images: Which Is Better for Preoperative Planning?

INTRODUCTION: Correct interpretation of a patient's anatomy and changes that occurs secondary to a disease process are crucial in the preoperative process to ensure optimal surgical treatment. In this study, we presented 3 different pancreatic cancer cases to surgical residents in the form of 3D-rendered images and 3D-printed models to investigate which modality resulted in the most appropriate preoperative plan. METHODS: We selected 3 cases that would require significantly different preoperative plans based on key features identifiable in the preoperative computed tomography imaging. 3D volume rendering and 3D printing were performed respectively to create 2 different training ways. A total of 30, year 1 surgical residents were randomly divided into 2 groups. Besides traditional 2D computed tomography images, residents in group A (n = 15) reviewed 3D computer models, whereas in group B, residents (n = 15) reviewed 3D-printed models. Both groups subsequently completed an examination, designed in-house, to assess the appropriateness of their preoperative plan and provide a numerical score of the quality of the surgical plan. RESULTS: Residents in group B showed significantly higher quality of the surgical plan scores compared with residents in group A (76.4 ± 10.5 vs. 66.5 ± 11.2, p = 0.018). This difference was due in large part to a significant difference in knowledge of key surgical steps (22.1 ± 2.9 vs. 17.4 ± 4.2, p = 0.004) between each group. All participants reported a high level of satisfaction with the exercise. CONCLUSION: Results from this study support our hypothesis that 3D-printed models improve the quality of surgical trainee's preoperative plans.

[Measurement of S-adenosylmethionine and S-adenosylhomocysteine in mice liver with high performance liquid chromatography].

OBJECTIVE: To develop a method for determination of S-adenosylmethionine (SAM) and S-adenosylhomocysteine (SAH) simultaneously in mice liver by reversed-phase high performance liquid chromatography (HPLC). METHODS: Mice livers were weighed, emulsified quickly by handheld homogenate, four times the volume of 0.6 mol/L HCLO4 added for ultrasonic, and the hydrolysate was adjusted to centrifuged and filtrated with a membrane. The supernatants were separatedonVenusil MP-C18 column (250 mm x 4.6 mm, 5 µm) at 30 °C with a mobile phase of 50 mmol/L NaH2PO4, 10 mmol/L C7H15NaO3S and methanol, a flow rate of 1.0 ml/min and UV detection at 254 nm. RESULTS: The SAM and SAH in the corresponding concentration range showed a good linear relation with its peak area, correlation coefficient ( r > 0. 9990 ) , recovery was 92.20%-101.38%, RSD was 2.88%-6.78%. The average within-day precision of SAM and SAH was 4.14% and 3.71%, and the average day to day precision was 7.51% and 9.54%. The content of SAM and SAH in mice liver was 3.14-6.09 mg/L (31.44-60.98 nmol/g wet weight) and 1.29-3.10 mg/L (13.38-32.17 nmol/g wet weight) respectively. CONCLUSION: The validated method is simple, rapid accurate and reliable to the determination of SAM and SAH in mice liver.

Management of retroperitoneal liposarcoma: A case report and review of the literature.

Retroperitoneal liposarcoma is a rare tumor with an incidence of 2.5 per million individuals. Early diagnosis is difficult as there is an absence of specific clinical presentations. The present case study reports a patient diagnosed with retroperitoneal liposarcoma who was treated by complete surgical resection and relapsed 3 months following the surgery. In addition, the clinical data of 14 patients with retroperitoneal liposarcoma were reviewed and analyzed. The mean age of the 14 patients at presentation was 54.1 (range, 36-73 years) and 5/14 patients experienced recurrence, ranging between 1 and 10 times. Of the 12 cases that reported histological subtypes, 7 were well-differentiated liposarcoma, 2 were dedifferentiated liposarcoma, 2 were myxoid liposarcoma and 1 was mixed subtype. All the patients underwent complete resection and 5 received combined multiple organs resection (3 nephrectomy, 1 sigmoid colon and 1 multiple visceral organs). However, no patients received chemotherapy or radiotherapy. In conclusion, retroperitoneal liposarcoma is a rare disease with a high rate of recurrence. Complete resection is the predominant treatment and combined resection of adjacent organs is occasionally necessary.

Effect of long-term pulsed electromagnetic field exposure on hepatic and immunologic functions of rats.

BACKGROUND: In this report, the effects of long-term pulsed electromagnetic field (PEMF) exposure on hepatic and immunologic functions were examined. METHODS: Male rats were randomly divided into four groups: a control group and three experimental groups exposed to a 50-Hz PEMF at 5, 10, or 20 mT for 10 weeks. RESULTS: Compared with the control group, activities of serum alanine aminotransferase and aspartate aminotransferase and concentrations of serum, liver, and spleen Metabolism of lipid peroxidation (MDA) in the 10- and 20-mT PEMF groups were significantly increased. The activities of Glutathione peroxidase (GSH-Px) and Superoxide Dismutase (SOD) in the serum, liver, and spleen and concentrations of serum immunoglobulins were significantly decreased. CONCLUSION: These results demonstrate that long-term exposure to PEMF can lead to oxidative damage of the liver and spleen.

The immature stages of Polypedilum (Pentapedilum) nodosum (Johannsen) and Polypedilum (Tripodura) masudai (Tokunaga) (Diptera, Chironomidae, Chironominae).

Based on associated material collected from Macau and Guangxi, the pupae and larvae of Polypedilum (Pentapedilum) nodosum Johannsen and P. (Tripodura) masudai Tokunaga are described completely for the first time. Both species are newly recorded from China. Characters for distinguishing the immature stage of these species from other allied Polypedilum species are noted. The previously recorded Polypedilum (Pentapedilum) 'K1' of Cranston  (1996) is shown to be P. nodosum. Information is provided on distribution and ecological tolerances. 

[Distribution characteristics of phosphorus forms in surface sediments of the Shantou Bay in China].

In order to know the horizontal distribution and seasonal variation characteristics of phosphorus species in surface sediment, the contents of different phosphorus species in the surface sediment sampling from Shantou Bay were determined by using the SMT sequential extraction method in September and November, 2008, and June, 2009. The contents of different phosphorus species basically showed an order of the low-water period, normal-water period and high-water period from high to low, and horizontal distributions of phosphorus species showed a decrease trend as waves from the inner bay to the outer bay with the maximum appeared in Niutianyang. The main form of total phosphorus in sediment was inorganic phosphorus, which accounted for 94.06%, and the content of Ca-P was the highest in all inorganic phosphorus of the surface sediment in Shantou Bay, comprising 70.21%, followed by Ads-P, Fe-P and De-P. The correlation analysis among different phosphorus forms suggested that they had similar sources and they were affected by surface runoff and seasonal variation. OP, Fe-P and Ads-P were bioavailable phosphorus, which were controlled by sources and water oxidation-reduction potential; while Ca-P and De-P were mainly influenced by biological processes and geological characteristics.

Source and profile of paralytic shellfish poisoning toxins in shellfish in Daya Bay, South China Sea.

Changes in cell density and cyst flux of Alexandrium tamarense, paralytic shellfish poisoning (PSP) toxin contents in shellfishes, and environmental parameters were measured in two stations in Daya Bay, South China Sea from March 2005 to July 2006. Vegetative cells of A. tamarense occurred sporadically; however, they presented abundantly during the winter months. Meanwhile, cyst flux reached its maximum level just following the peak abundance of motile cells. The PSP contents in shellfish were generally low, but higher in winter with the maximum of 14,015 µg STX equiv./kg. The majority of toxins were found in digestive glands, with a maximum of 66,227 µg STX equiv./kg. There were significant positive relationships between toxin level and vegetative cell density and cyst flux. This indicates that vegetative cells and cysts of Alexandrium significantly influenced PSP level, and could be an important source of PSP toxins in shellfish during winter.

[Preparation of anticolon carcinoma vaccine with rich chaperone peptides and study on its anticancer efficacy].

OBJECTIVE: To prepare the anticolon carcinoma vaccine with rich chaperone peptide and to examine its anticancer immunological efficacy. METHODS: CT26 colon carcinoma cells were cultured in 1 mg/L Trichosanthin 1640 medium at different temperatures to induce the chaperone expression and promote the synthesis of antigen peptides. Groups of these cells treated under the different condition were lysed by the sonic disintegration, and the lysates were centrifuged. The rawpurified proteins were obtained from the supernatants by precipitating with saturated ammonium sulfate and removing the molecules below 50,000 and above 300,000 in molecular weight via dialysis. Furthermore, the proteins with the molecular weights in 70,000, 90,000, 95,000, 110,000 and 170,000 were collected through gel filtration and SDS-PAGE. The purified proteins were analysed by Western blotting, and inspected on the anticancer immunological effects including lymphocyte proliferation and the activities of NK and CTL. RESULTS: Major of the chaperone peptides of anticancer effects in CT26 cells, including antigen peptides joining with HSP70, HSP90, gp96, HSP110 and HSP170, was satisfactorily extracted and condensed, and rich chaperone peptide composites were successfully obtained. The composites prepared under various condition could all enhance lymphocyte proliferation and the activities of CTL and NK(P<0.01). CONCLUSIONS: The rich chaperone peptide composites are successfully prepared via dialysis, salt fractionation and gel filtration combined with SDS-PAGE. Both the heat stress and Trichosanthin can increase the composites, which treated by 42 centi-degree heat stress and Trichosanthin are found to possess the strongest anticancer efficacy.

[Influence of chemotherapy with FOLFOX protocol on sex hormones of male patients and the protective effect of herbal medicines for reinforcing Shen and supplementing qi on it].

OBJECTIVE: To observe the influence of chemotherapy with FOLFOX protocol (CT-F) on sex hormones of male patients, and the protective and detoxifying effect of herbal medicines for reinforcing Shen and supplementing qi (HM) on it. METHODS: The randomized block control and self-control design was adopted to retrospectively investigate the changes of sex hormones in 61 patients with cancer of colon, rectum or stomach. They were assigned to four groups, A: treated simply with HM; B: treated with CT-F; C: treated with CT-F combined with HM; D: the blank control group. One course of CT-F composed of 1 month treatment, and 6 courses totally were applied on each patients. The levels of luteinizing hormone (LH), estradiol (E2), prolactin (PRL), progesterone (P), testosterone (T) and follicle-stimulating hormone (FSH) were determined before treatment (T0), at the end of the 6th month treatment (T1) and the 12th month (T2) after starting treatment. RESULTS: Levels of LH, PRL and T were significantly lowered in the group B at T1, being 4.6 +/- 0.4 IU/L, 8.6 +/- 0.7 microg/L and 13.1 +/- 1.4 IU/L, respectively, which were significantly different to those in the other 3 groups at the corresponding time; they were somewhat raised after chemotherapy but still lower at T2 than those at T0, being 5.0 +/- 0.4 IU/L, 9.9 +/- 1.1 microg/L and 14.1 +/- 1.4 IU/L respectively, also lower than the corresponding levels in the other 3 Groups (P<0.05 or P<0.01). In group C, LH significantly lowered at T1 (P<0.05) to 5.1 +/- 0.4 IU/L, but it was restored to the levels of T0 and that in Group D, reaching 6.1 +/- 0.5 IU/L; while PRL and T were changed insignificantly in the chemotherapeutic course, and restored at T2 to the level of T0, comparable to that in group D. Contrarily, levels of E2 and FSH increased significantly (P <0.01) in group B after chemotherapy (at T1) to 135 +/- 14 pmol/L and 9.1 +/- 1.1 IU/L respectively, and till T2, being 140 +/- 15 pmol/L and 9.1 +/- 1.o IU/L, they were lower than those at T0 and higher than those in group D, A and C ( all P <0.01), but the two indexes were not significantly increased in group C, being 116 +/- 12 pmol/L and 7.1 +/- 0.9 IU/L at T1. However, all the parameters showed no significant change in group A and D, and the level of P showed insignificant change in all the groups in the whole observation period. CONCLUSION: CT-F could induce multiple sex hormonal abnormalities in male patients with post-operational gastrointestinal cancer, and HM shows protective and detoxifying effects on them in different degrees.

[Changes of interleukin-1beta and tumor necrosis factor-alpha of right atrial appendages in patients with rheumatic valvular disease complicated with chronic atrial fibrillation].

OBJECTIVE: To investigate whether atrial expression of interleukin-1beta (IL-1beta) and tumor necrosis factor-alpha (TNF-alpha) of right atrial appendages are altered in patients with rheumatic valvular disease during chronic atrial fibrillation. METHODS: A total of 48 patients with rheumatic heart disease were included. 27 patients had no history of atrial fibrillation, 21 patients had atrial fibrillation. Atrial tissue was obtained from the right atrial appendage during open heart surgery. The protein expression of IL-1beta and TNF-alpha was detected by immunohistochemistry method. The fibrosis of right atrial appendage was detected by Masson staining. RESULTS: The fibrosis of right atrial appendage was significantly increased in patients with chronic atrial fibrillation. The protein expression of IL-1beta and TNF-alpha were significantly increased in patients with chronic atrial fibrillation. CONCLUSIONS: The protein expression of IL-1beta and TNF-alpha were significantly increased in patients with rheumatic valvular disease during chronic atrial fibrillation. Inflammation may be one of the mechanisms for the development and persistence of atrial fibrillation.

The effectiveness of processed grapefruit-seed extract as an antibacterial agent: II. Mechanism of action and in vitro toxicity.

OBJECTIVES: Recent testimonials report grapefruit-seed extract, or GSE (Citricidal) to be effective against more than 800 bacterial and viral strains, 100 strains of fungus, and a large number of single and multicelled parasites. This study investigated GSE for antibacterial activity at varying time intervals and concentration levels and tissue toxicity at varying concentrations in an effort to determine if a concentration existed that was both microbicidal and nontoxic and in what period of time. DESIGN: Gram-negative and gram-positive isolates were introduced into graduated dilutions of GSE (twofold concentrations ranging from 1:1, through 1:512) for determination of bacterial activity. In vitro assays with human skin fibroblast cells were also performed at the same dilutions to determine toxicity. RESULTS: These tests indicated that from the 1:1 through the 1:128 concentrations, GSE remained toxic as well as bactericidal. However, test results indicated that at the 1:512 dilution, GSE remained bactericidal, but completely nontoxic. CONCLUSIONS: The initial data shows GSE to have antimicrobial properties against a wide range of gram-negative and gram-positive organisms at dilutions found to be safe. With the aid of scanning transmission electron microscopy (STEM), the mechanism of GSE's antibacterial activity was revealed. It was evident that GSE disrupts the bacterial membrane and liberates the cytoplasmic contents within 15 minutes after contact even at more dilute concentrations.