Vulvar cancer recurrence — an analysis of prognostic factors in tumour-free pathological margins patients group

Objectives: To evaluate risk factors associated with the local recurrence of invasive squamous cell vulvar cancer in patient group with tumor-free pathological margins. Material and methods: This is a retrospective analysis of 47 patients who underwent surgical treatment at University Hospital Brno, the Czech Republic between 2007 and 2014. 24 patients were classified as IB stage and three as II stage. A further 20 patients representing stage III showed the metastatic involvement of regional lymph nodes. Seven prognostic factors were analyzed in relation to local tumour recurrence: tumour size, margin distance, depth of invasion, lymphovascular space involvement (LVSI), midline involvement, metastatic lymph nodes and FIGO stage. Results: All prognostic factors were found to be statistically significant with respect to the risk of local recurrence. The highest risk of local recurrence was observed for the depth of invasion > 5 mm (HR, 12.42 [95% CI; 3.44–44.84]) and for the presence of LVSI (HR, 10.83 [95% CI; 3.87–30.28]). The study also established a clear difference in the risk of local recurrence between patient groups with resection margin < 8 vs. ≥ 8 mm (HR, 4.91 [95% CI; 1.73–13.93; p = 0.003]. Conclusions: Tumour-free pathological margin of ≥ 8 mm is a major prognostic factor of local recurrence which can be influenced by the surgeon. A perfect knowledge of the extent of the disease prior to surgery supports adequately radical surgical trends. The emphasis is given on adequate radicality as well as on the reduction of overtreatment without worse­ning prognosis by simultaneously preserving the quality of life

Sex-specific Separation of Plasmodium falciparum Gametocyte Populations

Plasmodium falciparum is a unicellular eukaryotic parasite that causes malaria in humans. The parasite is spread by Anopheles mosquitoes after ingestion of sexual stage parasites known as gametocytes. Malaria transmission depends on parasites switching from the disease-causing asexual blood forms to male and female gametocytes. The current protocol allows the simultaneous isolation of male and female parasites from the same population to study this critical lifecycle stage in a sex-specific manner. We have generated a transgenic P. falciparum cell line that expresses a GFP-tagged parasite protein in female, but not male, parasites. Gametocyte production is stress induced and, through a series of steps, sexual stage parasites are enriched relative to uninfected red blood cells or red blood cells infected with asexual stage parasites. Finally, male and female gametocytes are separated by fluorescence- activated cell sorting. This protocol allows for the separation of up to 12 million live male and female parasites from the same population, which are amenable to further analysis.We are grateful to the Australian Red Cross for providing human red blood cells and serum. Funding was provided by the Australian Research Council (DP180103212). M.C.R. is supported by the Australian Government Research Training Program Scholarship and The Australian National University

Novel Method for the Separation of Male and Female Gametocytes of the Malaria Parasite Plasmodium falciparum That Enables Biological and Drug Discovery

We developed a flow-cytometry-based method to separate and collect cocultured male and female Plasmodium falciparum gametocytes responsible for malaria transmission. The purity of the collected cells was estimated at >97% using flow cytometry, and sorted cells were observed by Giemsa-stained thin-smear and live-cell fluorescence microscopy. The expression of validated sex-specific markers corroborated the sorting strategy. Collected male and female gametocytes were used to confirm three novel sex-specific markers by quantitative real-time PCR that were more enriched in sorted male and female gametocyte populations than existing sex-specific markers. We also applied the method as a proof-of-principle drug screen that allows the identification of drugs that kill gametocytes in a sex-specific manner. Since the developed method allowed for the separation of male and female parasites from the same culture, we observed for the first time a difference in development time between the sexes: females developed faster than males. Hence, the ability to separate male and female gametocytes opens the door to a new field of sex-specific P. falciparum gametocyte biology to further our understanding of malaria transmission.Funding was provided by the Australian Research Council (DP180103212). M.C.R. is supported by the Australian Government Research Training Program Scholarship and The Australian National Universit

Development of new silver nanoparticles suitable for materials with antimicrobial properties.

Silver nanoparticles are the most important nanoparticles in connection with the antimicrobial effect. Nowadays, the green synthesis of various types of nanoparticles is rapid, effective and produce less toxic nanoparticles often with specific properties. In our experiment we have developed and described in details various types of silver nanoparticles synthesized chemically or by the green synthesis. Nine different silver nanoparticles were synthesized, three by citrate method at different pHs (8; 9; 10), four using gallic acid at alkaline pHs (10; 11), and two by green synthesis using green tea and coffee extracts, both at pH 9. Characterisation of silver nanoparticles was performed using dynamic light scattering, scanning electron microscopy, and ultraviolet-visible absorption spectroscopy. Silver nanoparticles prepared by green synthesis showed the highest antioxidant activity and also ability for quenching of free radicals. Antibacterial activity of silver nanoparticles was determined on bacterial cultures such as Staphylococcus aureus and Escherichia coli. Silver nanoparticles synthesized using green tea and coffee extracts showed the highest antibacterial activity for both bacterial strains. Minimal inhibition concentration for both strains was found to be 65 {aelig}M at each silver nanoparticle synthesized using green synthesis

Antimicrobial Nanomaterials in the Food Industry

Nanoparticles of metals interacting with cellular components and biomacromolecules including DNA and RNA alter cellular processes. Concerning the antimicrobial activity, the metal nanoparticles in nanomolar concentrations inhibit the growth of bacterial strains. Even though the general mechanism of metal nanoparticle action has not been fully understood yet, among current accepted schemes belong the damage of the microbial enzymes by the release of metal ions, the membrane integrity changes, penetration into the cytoplasm of bacteria and accumulation in the periplasmic space or the reactive oxygen species formation due to the effect of metal nanoparticles. Moreover, G+ bacteria react remarkably later on the effect of metal nanoparticles compared to G- bacteria, which is reflected in the later inhibition of cell division. The aim of this study is to describe the properties of metal nanoparticles (silver, selenium, copper or zinc nanoparticles) and to compare their antimicrobial properties in complex with chitosan on the bacterial strains Staphylococcus aureus and Escherichia coli

Biogenic selenium nanoparticles synthesized by Stenotrophomonas maltophilia SeITE02 loose antibacterial and antibiofilm efficacy as a result of the progressive alteration of their organic coating layer

Increasing emergence of drug-resistant microorganisms poses a great concern to clinicians; thus, new active products are urgently required to treat a number of infectious disease cases. Different metallic and metalloid nanoparticles have so far been reported as possessing antimicrobial properties and proposed as a possible alternative therapy against resistant pathogenic microorganisms. In this study, selenium nanoparticles (SeNPs) synthesized by the environmental bacterial isolate Stenotrophomonas maltophilia SeITE02 were shown to exert a clear antimicrobial and antibiofilm activity against different pathogenic bacteria, either reference strains or clinical isolates. Antimicrobial and antibiofilm capacity seems to be strictly linked to the organic cap surrounding biogenic nanoparticles, although the actual role played by this coating layer in the biocidal action remains still undefined. Nevertheless, evidence has been gained that the progressive loss in protein and carbohydrate content of the organic cap determines a decrease in nanoparticle stability. This leads to an alteration of size and electrical properties of SeNPs along with a gradual attenuation of their antibacterial efficacy. Denaturation of the coating layer was proved even to have a negative effect on the antibiofilm activity of these nanoparticles. The pronounced antimicrobial efficacy of biogenic SeNPs compared to the denatured ones can - in first instance - be associated with their smaller dimensions. This study showed that the native organic coating layer of biogenic SeNPs functions in avoiding aggregation and maintaining electrostatic stability of the nanoparticles, thus allowing them to maintain efficient antimicrobial and antibiofilm capabilities

A Novel Approach to Preoperative Risk Stratification in Endometrial Cancer: The Added Value of Immunohistochemical Markers

Background: The current model used to preoperatively stratify endometrial cancer (EC) patients into low- and high-risk groups is based on histotype, grade, and imaging method and is not optimal. Our study aims to prove whether a new model incorporating immunohistochemical markers, L1CAM, ER, PR, p53, obtained from preoperative biopsy could help refine stratification and thus the choice of adequate surgical extent and appropriate adjuvant treatment.Materials and Methods: The following data were prospectively collected from patients operated for EC from January 2016 through August 2018: age, pre- and post-operative histology, grade, lymphovascular space invasion, L1CAM, ER, PR, p53, imaging parameters obtained from ultrasound, CT chest/abdomen, final FIGO stage, and current decision model (based on histology, grade, imaging method).Results: In total, 132 patients were enrolled. The current model revealed 48% sensitivity and 89% specificity for high-risk group determination. In myometrial invasion >50%, lower levels of ER (p = 0.024), PR (0.048), and higher levels of L1CAM (p = 0.001) were observed; in cervical involvement a higher expression of L1CAM (p = 0.001), lower PR (p = 0.014); in tumors with positive LVSI, higher L1CAM (p = 0.014); in cases with positive LN, lower expression of ER/PR (p < 0.001), higher L1CAM (p = 0.002) and frequent mutation of p53 (p = 0.008).Cut-offs for determination of high-risk tumors were established: ER <78% (p = 0.001), PR <88% (p = 0.008), and L1CAM ≥4% (p < 0.001). The positive predictive values (PPV) for ER, PR, and L1CAM were 87% (60.8–96.5%), 63% (52.1–72.8%), 83% (70.5–90.8%); the negative predictive values (NPV) for each marker were as follows: 59% (54.5–63.4%), 65% (55.6–74.0%), and 77% (67.3–84.2%). Mutation of p53 revealed PPV 94% (67.4–99.1%) and NPV 61% (56.1–66.3%). When immunohistochemical markers were included into the current diagnostic model, sensitivity improved (48.4 vs. 75.8%, p < 0.001). PPV was similar for both methods, while NPV (i.e., the probability of extremely low risk in negative test cases) was improved (66 vs. 78.9%, p < 0.001).Conclusion: We proved superiority of new proposed model using immunohistochemical markers over standard clinical practice and that new proposed model increases accuracy of prognosis prediction. We propose wider implementation and validation of the proposed model