Treatment Options and the Management of Complications in Hydatid Cysts of the Liver in Endemic Regions.

BACKGROUND: Hydatid cyst of the liver induced by Echinococcus granulosus is a pervasive zoonotic disease in our region. Its incidence varies across age groups, contingent on community lifespans and hygiene standards. Therapeutic modalities include Puncture, Aspiration, Injection, Re-aspiration (PAIR), and surgery. Due the limited feasability of PAIR, we suggest that surgery represents the optimal treatment in all stages, especially in endemic regions, depending on patient-specific variables. METHOD: Patients with hydatid cyst of the liver treated with PAIR and surgery in our center between January 2016 and January 2022 were analyzed retrospectively. PAIR or cystectomy were applied in treatment. These were then compared in terms of efficacy, feasibility, and complications. RESULTS: A single hydatid cyst of the liver was detected in 184 of the 225 cases, two cysts in 33, and three or more cysts in eight. The largest cyst diameter was 233 × 124 mm in the surgery group and 100 × 90 mm in the PAIR group. One hundred thirty-three of the 225 patients underwent open surgery, and no recurrence was encountered in these. However, recurrence was observed 19 patients treated with PAIR. Allergic reaction developed in one case during surgery, postoperative abscess in two cases, biliary fistula in five, and pneumonia in one. CONCLUSION: Surgical treatment should represent the standard procedure since it is safe and effective, ensures complete elimination of the parasite, involves no intraoperative shedding, preserves healthy tissues, and minimizes the risk of long-term recurrence and cavity-related complications.

Sis2 regulates yeast replicative lifespan in a dose-dependent manner.

Application of microfluidic platforms facilitated high-precision measurements of yeast replicative lifespan (RLS); however, comparative quantification of lifespan across strain libraries has been missing. Here we microfluidically measure the RLS of 307 yeast strains, each deleted for a single gene. Despite previous reports of extended lifespan in these strains, we found that 56% of them did not actually live longer than the wild-type; while the remaining 44% showed extended lifespans, the degree of extension was often different from what was previously reported. Deletion of SIS2 gene led to the largest RLS increase observed. Sis2 regulated yeast lifespan in a dose-dependent manner, implying a role for the coenzyme A biosynthesis pathway in lifespan regulation. Introduction of the human PPCDC gene in the sis2Δ background neutralized the lifespan extension. RNA-seq experiments revealed transcriptional increases in cell-cycle machinery components in sis2Δ background. High-precision lifespan measurement will be essential to elucidate the gene network governing lifespan.

Gastric cancer diagnosis and staging in coronavirus disease 2019 (Covid-19) pandemic.

AIM: The aim of the study was to analyze whether COVID-19 cause a delay in the diagnosis of gastric cancer patients particularly in the TNM staging of the tumor, or not. MATERIAL AND METHODS: This retrospective single-center study included the patients diagnosed with gastric cancer from March, 2019 to December 2020. The patients were divided into two groups: baseline and the pandemic groups. The following parameters were compared between the groups; demographic data, numbers of newly diagnosed patients, type of the surgery, location of the tumor, frequency of neoadjuvant treatment, ASA score, length of hospital stay, clinical staging and pathologic TNM staging. RESULTS: The mean monthly number of newly diagnosed gastric cancer patients showed a significant decline from 7.5 to 5.6 (p< .001). There were no statistically significant differences between the groups with regard to the demographic factors, except CA 19-9 levels. Patients in the pandemic group had higher both clinical and pathological T-stages (p < 0.05). CONCLUSIONS: Our study showed a decline in the number of the newly diagnosed patients with gastric cancer during the pandemic and also more patients presented with advanced stage during the pandemic period. This study showed that the pandemic causes a potential delay in the diagnosis of gastric cancer patients. KEY WORDS: Cancer surgery, COVID-19, Gastric cancer, Gastric surgery SARS-COV-2, Pandemic.

Clinical importance of serum CEA and CA-19-9 levels in oesophagogastric junction adenocarcinomas.

INTRODUCTION: In recent years, the incidence of gastroesophageal junction tumors has increased rapidly in worldwide. AIM: To evaluate pretreatment serum carcinoembryonic antigen (CEA) and carbohydrate antigen (CA) 19-9 in oesophagogastric junction (OGJ) adenocarcinomas regarding clinicopathologic characteristics and overall survival. MATERIAL AND METHODS: Patients undergoing curative surgery diagnosed with OGJ adenocarcinoma in the gastrointestinal surgery clinic between 2007 and 2019 were included in the study retrospectively. Kaplan Meier and Log Rank tests were performed in survival analyses. Logistic regression analysis was performed to state the independent variables affecting survival. RESULTS: The mean age of the 70 patients included in the study was 59.78 ±10.49 (31-76) years. Serum CEA and CA 19-9 were high in 19 (27.1%) patients. CEA ≥ 5 ng/ml was found to be statistically significant in patients receiving neoadjuvant chemotherapy (NAC) and in patients with a high number of positive lymph nodes (N +) (p = 0.041 and p = 0.042, respectively). CA 19-9 positivity was statistically higher in patients with lymphovascular invasion (LVI) and diabetes mellitus (DM) (p = 0.042 and p = 0.012, respectively). The age and N+ findings of the patients in the CA 19-9-positive group were statistically significant compared to the patients in the CA 19-9-negative group (p = 0.039 and p = 0.007, respectively). Overall survival rates of 1-3 and 5 years were statistically significantly lower in patients who were CA 19-9 positive (p = 0.016). For patients in whom both tumour markers were positive, the N+ mean value was statistically significantly higher (p = 0.001). CONCLUSIONS: In our study, a significant relationship was found in terms of overall survival and serum CA 19-9 in OGJ adenocarcinoma, and it was associated with both tumour markers being positive and the mean N+ value.

The risk of post-polypectomy bleeding among patients receiving antithrombotic agents: A prospective observational study

ABSTRACT BACKGROUND: In July 2012, the Japan Gastroenterological Endoscopy Society updated their guidelines for gastroenterological endoscopy in patients receiving antithrombotic therapy. Colonoscopic polypectomy procedures are associated with a high risk of bleeding. OBJECTIVES: The present study evaluated the safety of colonoscopic polypectomy procedures in terms of bleeding, among patients receiving antithrombotic therapy. DESIGN AND SETTING: Prospective observational study conducted in a tertiary-level public cardiovascular hospital in Istanbul, Turkey. METHODS: Colonoscopic polypectomies carried out in a single endoscopy unit between July 2018 and July 2019 were evaluated prospectively. The patients' data, including age, gender, comorbidities, whether antithrombotic drug use was ceased or whether patients were switched to bridging therapy, polyp size, polyp type, polyp location, histopathology, resection methods (hot snare, cold snare or forceps) and complications relating to the procedures were recorded. RESULTS: The study was completed with 94 patients who underwent a total of 167 polypectomy procedures. As per the advice of the physicians who prescribed antithrombotic medications, 108 polypectomy procedures were performed on 60 patients without discontinuing medication and 59 polypectomy procedures were performed on 34 patients after discontinuing medication. The age, gender distribution and rate of bleeding did not differ significantly between the patients whose medication was discontinued and those whose medication was continued (P > 0.05). CONCLUSION: This study found that the colonoscopic polypectomy procedure without discontinuation of antithrombotic medication did not increase the risk of bleeding. This procedure can be safely performed by experienced endoscopists in patients with an international normalized ratio (INR) below 2.5.

Sarcopenia is associated with increased severe postoperative complications after colon cancer surgery.

INTRODUCTION: Studies have shown that sarcopenia is associated with poor outcomes in patients with gastrointestinal cancer undergoing surgery. We aimed to investigate the relationship between postoperative complications of sarcopenic patients who had been operated on for colon cancer and the effects on short-term mortality. MATERIAL AND METHODS: In this study, patients who had undergone colon cancer surgery between January 2013 and December 2018 were collected retrospectively. Sarcopenia was diagnosed by the skeletal muscle index (SMI) derived from a preoperative computed tomography scan. Multiple logistic regression analysis was performed to determine whether sarcopenia is associated with postoperative major complications (POMC). RESULTS: The study included 160 patients with a mean age of 62.4 ±12.6 years. Clavien-Dindo grade 1-2 (minor) complications were not significantly different between the groups (p = 0.896). However, grade ≥ 3 (major) complications were detected in 13 (17.8%) patients in the sarcopenic group (SG) and in 5 patients in the non-sarcopenic group (NSG) (5.7%) (p = 0.016). Length of intensive care unit (ICU) stay was longer in SG (p = 0.002) and there was no difference between 1-month and 6-month mortality rates (p = 0.273 and p = 0.402, respectively). According to univariate analyses, sarcopenia and age over 65 years were related to POMC. In multivariate analyses, sarcopenia (odds ratio = 3.039; 95% confidence interval 1.008-9.174; p = 0.048) and advanced age (odds ratio = 3.246; 95% confidence interval 1.078-9.803; p = 0.036) were found to be independent risk factors for POMC. CONCLUSIONS: This study showed that while sarcopenia is a risk factor for POMC, sarcopenia also prolongs the duration of ICU stay. Also sarcopenia has no effect on short-term mortality.

The risk of post-polypectomy bleeding among patients receiving antithrombotic agents: A prospective observational study.

BACKGROUND: In July 2012, the Japan Gastroenterological Endoscopy Society updated their guidelines for gastroenterological endoscopy in patients receiving antithrombotic therapy. Colonoscopic polypectomy procedures are associated with a high risk of bleeding. OBJECTIVES: The present study evaluated the safety of colonoscopic polypectomy procedures in terms of bleeding, among patients receiving antithrombotic therapy. DESIGN AND SETTING: Prospective observational study conducted in a tertiary-level public cardiovascular hospital in Istanbul, Turkey. METHODS: Colonoscopic polypectomies carried out in a single endoscopy unit between July 2018 and July 2019 were evaluated prospectively. The patients' data, including age, gender, comorbidities, whether antithrombotic drug use was ceased or whether patients were switched to bridging therapy, polyp size, polyp type, polyp location, histopathology, resection methods (hot snare, cold snare or forceps) and complications relating to the procedures were recorded. RESULTS: The study was completed with 94 patients who underwent a total of 167 polypectomy procedures. As per the advice of the physicians who prescribed antithrombotic medications, 108 polypectomy procedures were performed on 60 patients without discontinuing medication and 59 polypectomy procedures were performed on 34 patients after discontinuing medication. The age, gender distribution and rate of bleeding did not differ significantly between the patients whose medication was discontinued and those whose medication was continued (P > 0.05). CONCLUSION: This study found that the colonoscopic polypectomy procedure without discontinuation of antithrombotic medication did not increase the risk of bleeding. This procedure can be safely performed by experienced endoscopists in patients with an international normalized ratio (INR) below 2.5.

Relation between Sarcopenia and Surgical Site Infection in Patients Undergoing Gastric Cancer Surgery.

Background: Sarcopenia is a syndrome that can have negative consequences after gastric cancer (GC) surgery. This study aims to determine the effect of sarcopenia on surgical site infection (SSI) that develops after open GC surgery. Patients and Methods: In this retrospective design study, data were collected for patients who underwent GC surgery between January 2013 and August 2019. The diagnosis of sarcopenia was made according to the skeletal muscle index (SMI) calculated from pre-operative computed tomography images. Patients with sarcopenia and those without sarcopenia were compared in terms of SSIs; the risk factors for SSI were also analyzed. Results: One hundred forty-nine patients were included in the study and had a mean age of 59.3 years. Post-operative complications developed in 59 patients (39.6%) and SSIs in 28 patients (18.7%). Sarcopenia was detected in 57 (38.3%) patients; the mean age was 59.9 years in the sarcopenic group (SG) and 58.9 years in the non-sarcopenic group (NSG; p = 0.55). The mean SMI was 382.5 mm2/m2 and 646.2 mm2/m2 in the SG and NSG, respectively (p < 0.001). A relation between SSIs and sarcopenia was detected; 17 patients in the SG (29.8%) versus 11 patients in the NSG (11.9%; p = 0.007). Surgical site infection was not found to be statistically significantly related to obesity, hypoalbuminemia, intra-operative blood loss, or duration of operation, although the sarcopenic obesity patients were found to have the highest SSI rate (40%). Conclusion: The present study identified a relation between sarcopenia and SSIs occurring after GC surgery. The authors believe that studies seeking to reduce the incidence of SSIs, which are a leading cause of morbidity after GC surgery, should be supported.

The safety of upper gastrointestinal endoscopic biopsy in patients receiving antithrombic drugs. A single-centre prospective observational study.

INTRODUCTION: In July 2012, the Japan Gastroenterological Endoscopy Society updated their guidelines on gastroenterological endoscopy in patients undergoing antithrombotic therapy, although the safety of endoscopic procedures in patients receiving antithrombotic drugs has yet to be sufficiently studied. AIM: This study evaluates the safety of upper gastroenterological endoscopic biopsy in patients receiving antithrombotic drugs. We evaluated the prospective observational safety of endoscopic biopsy performed in the endoscopy unit of our patients using antithrombotic drugs. MATERIAL AND METHODS: Oesophagogastroduodenoscopies (OGD) and biopsies performed at a single endoscopy unit between July 2018 and February 2019 were examined in this prospective observational study. Patients receiving antithrombotic drugs due to cardiovascular and neurological reasons, who underwent an endoscopic mucosal biopsy for diagnostic purposes, were included in the study. RESULTS: The study was completed with 166 patients who underwent an endoscopic biopsy, from whom a total of 327 biopsies taken. The patients were examined in two groups: those "receiving antithrombotic drugs" and those who had "stopped taking antithrombotic drugs". There was no statistically significant difference between the two groups with respect to bleeding. CONCLUSIONS: This prospective observational study showed that performing an endoscopic biopsy without the cessation of antithrombotic drugs does not increase bleeding risk. Low-risk procedures, such as endoscopic mucosal biopsies, can be performed confidently by experienced endoscopists.

The impact of sarcopenia on pathologic complete response following neoadjuvant chemoradiation in rectal cancer.

PURPOSE: The role of sarcopenia in pathologic complete response (pCR) following neoadjuvant chemoradiotherapy (nCRT) in non-metastatic locally advanced rectal cancer is currently unknown. The present study investigates the association between sarcopenia and post-nCRT pCR. METHODS: The data of patients operated on following nCRT between January 2013 and January 2020 were collected retrospectively. Sarcopenia was diagnosed based on the calculation of the skeletal muscle index (SMI) from computed tomography carried out at the time of the initial diagnosis. A statistical analysis was then conducted for predictors of pCR. RESULTS: The study included 61 patients with an average age of 57.3 years, 28 of whom formed the non-sarcopenic group (NSG) and 33 the sarcopenic group (SG). Of the patients, 32.7% were at clinical stage 2, and 67.3% were at clinical stage 3. Pathologic data following a mesorectal excision revealed a pCR rate of 21.4% in the NSG compared with 3% in the SG, which was a statistically significant difference (p = 0.025). The TNM downstaging rate was higher in the NSG than in the SG, although the difference was not statistically significant (50% vs. 33.3%, p = 0.28). A univariate analysis revealed the factors affecting pCR to be non-sarcopenia (p = 0.025), age < 61 years (p = 0.004), interval to surgery ≥ 8 weeks (p = 0.029), and serum CEA < 2.5 ng/ml (p = 0.035). CONCLUSION: Sarcopenia was found to be a negative marker of pCR following nCRT in non-metastatic locally advanced rectal cancer.

The prognostic value of different lymph node classification systems in stage III colorectal cancer patients.

AIM: Prognostic significance assessment of different lymph node classification systems in stage III colorectal cancer patients. MATERIAL AND METHODS: A total of 85 stage III colorectal cancer patients, who had undergone surgery between January 2013 and December 2018, were divided into 3 different groups comprising of lymph node ratios (LNR) and log odds of positive lymph nodes (LODDS) as per the cutoff values of 25 and 75 percentile threshold values. They were accordingly classified as: LNR1 <0.069, LNR2 0.069-0.24, LNR3 >0.24 and LODDS1 <-0.99; -0.99≥ LODDS2 <-0.47; LODDS3 ≥-0.47. Further the LNR was assessed according to the cutoff values proposed by Berger et al. The pN statuses of all patients were also categorized as pN1 and pN2 in line with the AJCC 8th Edition. The Kaplan-Meier test and Cox regression analysis were performed to analyze the relationship among the LNR, LODDS, pN and overall survival. RESULTS: While 55 patients included in the study had tumors in their colons, the localization of the tumors of 30 patients was the rectum. The means for survival time was 63.3 months +/- 3.6 [95% CI(56.2-70.4)]. When univariate analyses were conducted for the factors affecting 3 and 5-year survival of the patients, it was ascertained that there was a significant relationship only between perineural invasion (PNI) and survival. Accordingly, the 3-year survival of those with PNI was found to be 31.4% in comparison to 56% of those without PNI (p=0.025), while the figure was 5.7% for the 5-year survival of the former group and 22% for the latter (p=0.040). When the relation between the survival time of the patients and the LNR classification conducted according to the staging system developed by Berger et al. was studied, no significant relationship could be found (p>0.05). Similarly, and 0.321 respectively. CONCLUSION: Although numerous studies have shown that there was a significant relationship between high LNR and increased survival, as opposed to the results of our study, the greatest obstacle before LNR's survival prediction is the absence of a consensus for standard cutoff values. KEY WORDS: Colorectal cancer, Lymph node classification systems, Lymph node ratio.

Characterization of the impact of GMP/GDP synthesis inhibition on replicative lifespan extension in yeast.

Slowing down aging-associated accumulation of molecular damage or its prevention represents a promising therapeutic paradigm to combat aging-related disease and death. While several chemical compounds extend lifespan in model organisms, their mechanism of action is often unknown, reducing their therapeutic potential. Using a systematic approach, here we characterize the impact of the GMP pathway on yeast lifespan and elucidate GMP synthesis inhibition as a lifespan extension mechanism. We further discover that proteasome activation extends lifespan in part through the GMP pathway. GMP synthesis inhibition exerts its lifespan extension effect independently of the canonical nutrient-sensing pathway regulating lifespan. Exposing longitudinally aging yeast cells to GMP pathway inhibition in an age-dependent manner, we demonstrate that the lifespan extension is facilitated by slowing, rather than reversing, the aging process in cells. Using a GUK1 mutant with lower GMP-to-GDP conversion activity, we observe lifespan extension, suggesting that reduced GDP level by itself can also extend yeast lifespan. These findings elucidate the involvement of nucleotide metabolism in the aging process. The existence of clinically-approved GMP pathway inhibitors elicits the potential of a new class of therapeutics for aging-related disorders.

Relationship between Sarcopenia and Surgical Site Infection in Patients Undergoing Colorectal Cancer Surgical Procedures.

Background: Sarcopenia is a syndrome that can be associated with unfavorable outcomes after colorectal cancer surgical procedures. The present study evaluates the relationship between sarcopenia and surgical site infections (SSIs) that can occur after colorectal cancer operations and that are a significant cause of morbidity. Methods: The research was designed as a retrospective study in which data were collected on patients who underwent colorectal cancer surgical procedures between January 2013 and July 2019. A diagnosis of sarcopenia was established based on the skeletal muscle index (SMI), calculated from pre-operative computed tomography scans. The SSI scores of patients with sarcopenia (sarcopenic group, SG) and those without sarcopenia (non-sarcopenic group, NSG) were compared, and a logistic regression analysis was performed to determine the risk factors for SSI. Results: A total of 209 patients with a mean age of 61.2 years were included in the study. Post-operative complications (Clavien-Dindo ≥1) developed in 97 (46.4%) patients, SSIs developed in 46 (22%) patients, and sarcopenia developed in 97 (46.4%) patients. The mean age was 64.8 years in the SG group and 58.1 years in the NSG group (p = 0.016). No significant relationship was found between the development of SSI and sarcopenia (20 (20.6%) patients in the SG vs. 26 (23.2%) patients in the NSG, p = 0.65). Those in whom superficial SSIs developed in the early period formed the largest group (20 patients). The most commonly detected micro-organism was Escherichia coli with a rate of 55%. In a multi-variable logistic regression analysis, only the non-laparoscopic approach was identified as a risk factor (odds ratio 3.83; 95% confidence interval 1.26-11.58; p = 0.017). Conclusions: The present study reports no relationship between sarcopenia and SSI after colorectal cancer operations. The authors consider that studies that endeavor to reduce the incidence of SSI, as a significant cause of morbidity after colorectal surgical procedures, should be supported.

Synthetic Genetic Circuits for Self-Actuated Cellular Nanomaterial Fabrication Devices.

Genetically controlled synthetic biosystems are being developed to create nanoscale materials. These biosystems are modeled on the natural ability of living cells to synthesize materials: many organisms have dedicated proteins that synthesize a wide range of hard tissues and solid materials, such as nanomagnets and biosilica. We designed an autonomous living material synthesizing system consisting of engineered cells with genetic circuits that synthesize nanomaterials. The circuits encode a nanomaterial precursor-sensing module (sensor) coupled with a materials synthesis module. The sensor detects the presence of cadmium, gold, or iron ions, and this detection triggers the synthesis of the related nanomaterial-nucleating extracellular matrix. We demonstrate that when engineered cells sense the availability of a precursor ion, they express the corresponding extracellular matrix to form the nanomaterials. This proof-of-concept study shows that endowing cells with synthetic genetic circuits enables nanomaterial synthesis and has the potential to be extended to the synthesis of a variety of nanomaterials and biomaterials using a green approach.

Effect of Triclosan-Coated Suture on Surgical Site Infection of Abdominal Fascial Closures.

Background: Surgical site infections (SSIs) are a serious problem after abdominal surgery. This study aimed to compare closure of fascia with triclosan-coated monofilament polydioxanone (PDS) or standard PDS in decreasing the incidence of SSIs in patients who underwent abdominal surgery. Methods: In this randomized study, a total of 890 consecutive patients undergoing laparotomy for any gastrointestinal pathology were allocated to closure of the fascia with triclosan-coated PDS (treatment group; TG) or standard PDS (control group; CG). Patients were assessed every day during the hospital stay for SSIs and at the first, second, and fourth week after discharge. The surgical site was assessed in terms of superficial, deep incisional, or organ/site SSI. Results: The main important finding was that SSIs were reduced as much as 24% by using triclosan-coated PDS. Surgical site infections occurred in 200 patients (22.4%), with 105 being early (in the first week) and 95 occurring late. Eighty five of the SSIs (19.1%) were noted in patients in the TG, whereas 115 of them (25.8%) were in the CG (p = 0.016). The infections were superficial in 126 patients, deep incisional in 48 patients, and organ/site in 26 patients. Most of patients (n = 651) had clean-contaminated sites. In subgroup analysis, SSI rates with triclosan-coated PDS were lower in clean, clean-contaminated, and contaminated incisions (0 in the TG versus 24.2% in the CG; p = 0.009; 13.6% in the TG versus 24.3% in the CG, p = 0.001; and 16.6% in the TG versus 27.8% in the CG; p < 0.0001, respectively). Conclusions: Closure of the fascia with triclosan-coated PDS decreased SSI rates as much as 24%. Also, SSIs were decreased significantly at clean, clean-contaminated, and contaminated sites. Therefore, triclosan-coated PDS might be recommended for fascial closure as a means of decreasing SSIs.

A rare case of Castleman disease mimicking a pancreatic tumor.

Castleman's disease or angiofollicular lymph node hyperplasia is a rare clinical entity, and may involve any parts of the body. Unicentric presentation of the disease is the most common presentation. Castleman's disease of the pancreas that mimics a pancreatic neoplasm is more uncommon. We present a 38-year-old female patient with a one-month past history of abdominal pain. Imaging studies revealed hypervascular, 4 x 2 cm in size nodular mass localised in the pancreatic body. In FDG PET/CT, the pancreatic mass was FDG-avid. Laparoscopic enucleation of the lesion was performed. Histopathological study revealed unicentric form of Castleman's disease, a hyaline vascular variant. Since these lesions are rare and resembling malignant tumors on computed tomography and angiography, we discuss the problems of diagnosing Castleman's disease, together with the literature. KEY WORDS: Castleman's disease, Lymphoid Follicular hyperplasia, Lymphoproliferative disorder, Peripancreatic tumor.

Autonomous Synthesis of Fluorescent Silica Biodots Using Engineered Fusion Proteins.

Formation of biological materials is a well-controlled process that is orchestrated by biomolecules such as proteins. Proteins can control the nucleation and mineralization of biomaterials, thereby forming the hard tissues of biological organisms, such as bones, teeth, and shells. In this study, the design and implementation of multifunctional designer proteins are demonstrated for fluorescent silica micro/nanoparticle synthesis. The R5 motif of silaffin polypeptide, which is known for its silicification capability, was fused genetically into three spectrally distinct fluorescent proteins with the intention of forming modified fluorescent proteins. The bifunctional R5 peptide domain served as a tag to provide silica synthesis at ambient conditions. Three functional fusion constructs have been prepared, including GFPmut3-R5, Venus YFP-R5, and mCherry-R5. Recombinant fluorescent proteins were purified using silica-binding peptide tag through silica gel resin. Purified proteins were tested for their binding affinity to silica using quartz crystal microbalance with dissipation monitoring to make sure they can interact strong enough with the silica surfaces. Later, engineered fluorescent proteins were used to synthesize silica nano/microparticles using silica precursor materials. Synthesized silica particles were investigated for their fluorescence properties, including time-resolved fluorescence. Additionally, elemental analysis of the particles was carried out using electron energy loss spectroscopy and energy-filtered transmission electron microscopy. Last, they were tested for their biocompatibility. In this study, we aimed to provide a biomimetic route to synthesize fluorescent silica nanoparticles. Recombinant fluorescent proteins-directed silica nanoparticles synthesis offers a one-step, reliable method to produce fluorescent particles both for biomaterial applications and other nanotechnology applications.

Self-assembly of bacterial amyloid protein nanomaterials on solid surfaces.

HYPOTHESIS: Amyloid-forming biofilm proteins of Escherichia coli, namely CsgA and CsgB, can form self-assembled nanofibers on solid surfaces. These proteins can be programmed to form bio-nanomaterials for functional applications. EXPERIMENTS: In this study, the assembly of the CsgA and CsgB protein on solid surfaces was investigated in real time using a quartz crystal microbalance instrument with dissipation monitoring. The assembly kinetics of the CsgA and CsgB proteins in various settings on solid surfaces were investigated. Protein nanowires were investigated using electron microscopy. FINDINGS: CsgA protein polymers and CsgB-added CsgA polymers form densely packed biofilm on gold surfaces, whereas CsgB polymers and CsgA-added CsgB polymers form biofilms with high water-holding capacity according to the dissipation data. Electron microscopy images of nanofibers grown on gold surfaces showed that CsgA and CsgB polymers include thicker nanofibers compared to the nanofibers formed by CsgA-CsgB protein combinations. The resulting nano/microstructures were found to have strong fluorescence signals in aqueous environments and in chloroform while conserving the protein nanowire network.

Biosystems Engineering of Prokaryotes with Tumor-Killing Capacities.

Certain bacteria selectively attack tumor tissues and trigger tumor shrinkage by producing toxins and modulating the local immune system, but their clinical utility is limited because of the dangers posed by systemic infection. Genetic engineering can be used to minimize the risks associated with tumor-targeting pathogens, as well as to increase their efficiency in killing tumor cells. Advances in genetic circuit design have led to the development of bacterial strains with enhanced tumor-targeting capacities and the ability to secrete therapeutics, cytotoxic proteins and prodrug-cleaving enzymes, which allows their safe and effective use for cancer treatment. The present review details the recent advances in the design and application of these modified bacterial strains.

Correlations in metal release profiles following sorption by Lemna minor.

Following the rapid uptake of contaminants in the first few hours of exposure, plants typically attempt to cope with the toxic burden by releasing part of the sorbed material back into the environment. The present study investigates the general trends in the release profiles of different metal(loid)s in the aquatic macrophyte Lemna minor and details the correlations that exist between the release of metal(loid) species. Water samples with distinct contamination profiles were taken from Nilüfer River (Bursa, Turkey), Yeniçaga Lake (Bolu, Turkey), and Beysehir Lake (Konya, Turkey) and used for release studies; 36 samples were tested in total. Accumulation and release profiles were monitored over five days for 11 metals and a metalloid ((208)Pb, (111)Cd, (52)Cr,(53)Cr,(60)Ni,(63)Cu,(65)Cu,(75)As,(55)Mn, (137)Ba, (27)Al, (57)Fe, (66)Zn,(68)Zn) and correlation, cluster and principal component analyses were employed to determine the factors that affect the release of these elements. Release profiles of the tested metal(loid)s were largely observed to be distinct; however, strong correlations have been observed between certain metal pairs (Cr/Ni, Cr/Cu, Zn/Ni) and principal component analysis was able to separate the metal(loid)s into three well-resolved groups based on their release.