Modification of T9SS cargo proteins of Porphyromonas gingivalis for their secretion in soluble form and purification by affinity chromatography.

Background: Porphyromonas gingivalis, a keystone-pathogen associated with periodontitis, utilizes the Type IX Secretion System (T9SS) to secrete proteins bearing the conserved C-terminal domain (CTD), many of which are essential virulence factors. These include, besides gingipains and PPAD, 29 other proteins. During or after the outer membrane translocation the CTD is cleaved off and a glycan moiety is covalently attached anchoring the secreted proteins at the bacterial cell surface. Objective: Most of the CTD bearing proteins have only hypothetical functions assigned. It is plausible that these CTD bearing proteins may also play a crucial role in P. gingivalis pathogenesis. Therefore, it would be of interest to determine their precise role, which could be accomplished through protein purification and subsequent characterization. Three CTD proteins were chosen as first targets: C25 peptidase (PG_RS01820), Carboxypeptidase D (PG_RS01060; Cpg70) and Periodontain (PG_RS06260; PrtT related). Methods: It was shown previously that the insertion of a hexahistidine affinity tag upstream of the CTD in RgpB and PPAD results in secretion of soluble, non-glycosylated, mature forms of these enzymes into the culture media, this facilitates their purification by nickel-chelate affinity chromatography. This same approach was applied in the present study. Results: Isogenic mutant strains of P. gingivalis with the insertion of a hexahistidine affinity tag upstream of the CTD were generated via homologous recombination. The presence of soluble proteins bearing the hexahistidine tag in growth media were confirmed for carboxypeptidase D (CPG70) and periodontain (PrtT related) expressing strains. These two proteins were then purified to homogeneity by Ni-Sepharose affinity chromatography. Conclusion: Purification of two CTD bearing proteins out of three chosen targets, confirmed that the applied method can be successfully used for purification of other proteins from this family. In the case of C25 peptidase the failure to find the His-tagged protein can be due to very low expression level

Platelet-Rich Fibrin: Utilization in the Treatment of Periodontitis

Periodontitis is a chronic inflammatory disease affecting the supporting structures of the teeth and results in loss of supporting bone around the teeth leading to eventual tooth loss. It is a multifactorial disease that involves bacteria and host responses. Advanced options to treat periodontitis are aimed at regeneration procedures to restore lost periodontal structures. These include bone replacement grafts and the use of biological materials to enhance regeneration. Platelet-rich fibrin (PRF) is an autologous platelet-rich concentrate derived from a fibrin clot and is a natural source of growth factors derived from platelets, which are released over time and have been shown to have potential in periodontal procedures to enhance wound healing and regeneration. This chapter will focus on the past, current and future scope of PRF for treating periodontitis

Evaluation of the response rate of chemo-radiation and brachytherapy in patients with locally advanced carcinoma cervix in a tertiary care center

Background: Incidence and mortality estimates are used to measure the burden of cancer in a population and survival estimates are ideal for evaluating the outcome of cancer control activities. Survival studies evaluate the quality and quantity of life of a group of patients after diagnosing the disease. The patient survival after the diagnosis of cervical cancer is indirectly influenced by socio-economic factors. The present study was carried out with an aim to evaluate the success rate of chemo-radiation followed by brachytherapy to the patients of locally advanced carcinoma (Ca.) cervix in a tertiary care center.Methods: All cases were staged according to the International Federation of Gynaecologists and Oncologists (FIGO) staging system. To illustrate the observed survival of cancer patients Kaplan-Meier curve was plotted. All the patients, except one, completed chemo-radiation and were retrospectively analyzed for the presence of local residual disease, local recurrence, distant metastases, radiation reactions, disease-free survival, and overall survival.Results: There were 22 patients of Carcinoma cervix reported in the radiation oncology department in the year 2018 and 2019. The overall treatment time ranged from 30 days to 178 days, with a median of 63 days. All the patients had a complete response after the treatment. The median follow-up time for all the patients was 15 months. Three patients had a metastatic recurrence and one patient developed distant metastases as well as local recurrence. Overall survival rate was 100% while the disease-free survival rate was 81.82%.Conclusions: The response to chemo-radiation in the treatment of locally advanced Carcinoma cervix is comparable to historic data and is well tolerated

Effects of platelet‐rich fibrin on human gingival and periodontal ligament fibroblast proliferation from chronic periodontitis versus periodontally healthy subjects

Background: Platelet-rich fibrin (PRF), an autogenous blood concentrate, contains multiple growth factors and is used as an adjunct in the periodontal regeneration and implant site development procedures to stimulate wound healing. Patient-related factors such as chronic periodontitis may affect the quality of PRF. Objectives: This study aimed to investigate and compare PRF's effects from patients diagnosed with generalized moderate or severe chronic periodontitis to patients who presented with intact periodontium on human gingival fibroblast (HGF) and human periodontal ligament fibroblast (HPLF) proliferation. Materials and methods: A total of 33 ml of whole intravenous blood was collected from each subject and centrifuged at 2700 rpm for 12 min in three 10 ml tubes, and 3 ml of blood was used for Complete Blood Count analysis. Three PRF clots were compressed to produce the membranes and liquid exudate. PRF membrane and 10% liquid exudate were exposed to 20,000 HPLFs/well or 25,000 HGFs/well in triplets from each subject in a 48 cell well plate. After 72 h of incubation, the conditioned media were evaluated by Water Soluble Tetrazolium-1 assays to determine fibroblast proliferation. Controls included cells alone and media without cells. Complete blood counts were measured. Results: Subjects in both groups were age and gender-matched (intact 46.7 ± 11.4 years and periodontitis 54.8 ± 10.4 years, p-value = 0.1344). Body Mass Index and White Blood Corpuscles in the periodontitis group was significantly higher than the intact group (p = 0.0176 and p = 0.0038) whereas no differences were seen for Red Blood Corpuscles (p = 0.2020), Hemoglobin (p = 0.2290) and Platelets (p = 4,094). There were no significant differences in the HGF and HPLF proliferation with PRF exudates and membranes between intact periodontium and periodontitis groups (all p > 0.05). However, PRF exudates in both groups induced significant more cell proliferation when compared to PRF membranes. Conclusions: PRF exudates induced significant proliferation of fibroblasts and can play a vital role in wound healing. The current study concluded that PRF membranes, in combination with PRF exudates, can be utilized for their therapeutic and wound healing potential, not affected by the periodontal condition of the patient

Structural and functional probing of PorZ, an essential bacterial surface component of the type-IX secretion system of human oral-microbiomic Porphyromonas gingivalis.

Porphyromonas gingivalis is a member of the human oral microbiome abundant in dysbiosis and implicated in the pathogenesis of periodontal (gum) disease. It employs a newly described type-IX secretion system (T9SS) for secretion of virulence factors. Cargo proteins destined for secretion through T9SS carry a recognition signal in the conserved C-terminal domain (CTD), which is removed by sortase PorU during translocation. Here, we identified a novel component of T9SS, PorZ, which is essential for surface exposure of PorU and posttranslational modification of T9SS cargo proteins. These include maturation of enzyme precursors, CTD removal and attachment of anionic lipopolysaccharide for anchorage in the outer membrane. The crystal structure of PorZ revealed two β-propeller domains and a C-terminal β-sandwich domain, which conforms to the canonical CTD architecture. We further documented that PorZ is itself transported to the cell surface via T9SS as a full-length protein with its CTD intact, independently of the presence or activity of PorU. Taken together, our results shed light on the architecture and possible function of a novel component of the T9SS. Knowledge of how T9SS operates will contribute to our understanding of protein secretion as part of host-microbiome interactions by dysbiotic members of the human oral cavity

De Novo Vesicoureteral Reflux Following Ureterocele Decompression in Children: A Systematic Review and Meta-Analysis Comparing Laser Puncture versus Electrosurgical Incision Techniques

Background: The available endoscopic techniques for ureterocele decompression include laser puncture (LP), electrosurgical incision (ES), and cold-knife incision. This systematic review was performed to compare the efficacy of LP versus ES techniques with special emphasis on de novo VUR. Methods: Four databases were systematically searched by the authors. The inclusion criteria were all comparative studies in which ureterocele decompression was performed by either LP or ES endoscopic techniques. Outcomes including the incidence of de novo VUR, the need for endoscopic retreatment of the ureterocele, and the need for secondary surgical procedures were studied. Risk ratios (RR) were calculated for all outcomes and the Mantel-Haenszel method was utilized for the estimation of pooled RR. The methodological quality was assessed by the Downs and Black scale. Results: Five studies were considered for systematic review, while four of them were included in the meta-analysis. Out of 202 children, 67 developed de novo VUR. Significantly lower rates of reflux were observed in the LP group vis-a-vis ES group (RR = 0.17, 95% CI 0.09 to 0.32, p < 0.00001). Endoscopic retreatment rates (n = 20) demonstrated no significant difference among the two patient groups (RR = 0.66, 95% CI 0.26–1.68, p = 0.38). A total of 46 secondary procedures were performed in 170 children, mostly ureteral re-implantations, with a significantly lower need of secondary surgeries following LP versus ES (RR = 0.26, 95% CI 0.13–0.49, p < 0.0001). The risk of bias in the included studies was low-to-moderate. Conclusions: When compared to the ES technique, the LP technique is associated with a significantly low incidence of de novo VUR and requirement for secondary surgeries (particularly anti-reflux surgeries). Endoscopic retreatment rates showed no significant difference between the two techniques. However, due to the moderate risk of bias in two out of four included studies, randomized controlled trials are needed in the future

Comparison of Unnoticed Glove Perforations during Minimally Invasive versus Open Surgeries: A Systematic Review and Meta-Analysis

Objective: Various studies have depicted the incidence of glove perforations during open (OS) and minimally invasive surgeries (MIS). The aim of this meta-analysis was to compare the incidence of macroscopic and microscopic glove perforations during MIS and OS. Methods: The review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Scientific databases (PubMed, Web of Science, Scopus, and EMBASE) were systematically searched for comparative studies depicting the glove perforation rates during MIS and OS. Risk ratios (RR) were calculated for both the outcomes (dichotomous) and the Mantel–Haenszel method was utilized for the estimation of pooled RR. The methodological quality assessment was performed by two independent investigators using the Downs and Black scale. The main outcomes of the study were the proportion of gloves with gross (macroscopic) perforations and the proportion of gloves with microscopic perforations. Results: Four comparative studies including a total of 1428 gloves (435 from the MIS group) were included. Pooling the data demonstrated no difference in the incidence of macroscopic glove perforations among the MIS and OS groups (RR 0.57, 95% CI 0.21 to 1.54, p = 0.27). On the other hand, the incidence of microscopic perforations was significantly higher in the OS group versus the MIS group (RR 0.72, 95% CI 0.55 to 0.95, p = 0.02). However, all the studies had a moderate risk of bias. Conclusions: When compared to OS, the macroscopic glove perforation rate during MIS showed no significant difference. The incidence of microscopic glove perforations was significantly higher during OS as compared to MIS. However, due to the moderate risk of bias of the available comparative studies, the level of evidence of these studies is limited

Multimodality Management of Two Pairs of Pyopagus Twins

Background and Aim: Conjoined twins, due to their rarity and complex anatomy, pose not only a technical, but also a physiological challenge for their separation, with each case being uniquely distinct. The aim of the present article is to describe the surgical approach and management strategy for two cases of pyopagus conjoined twins operated at our center. Case Report: Case 1: Antenatally detected conjoined twin girls presented postnatally to our centre. They were found to have a common vestibule with single anal opening facing partially away from each other. On evaluation they were found to have a single sacrum and fused conus and filum terminale. They were taken up for separation at 2years of age & the 24hour long surgery, culminated in successful separation. The children had good post-operative outcome at 10months post separation. Case 2: Conjoined pyopagus twin girls presented postnatally, and were found to have fused cords, having a terminal syrinx and partially separate sacrum. They were separated at 2.5 years of age, with a multi-departmental effort and coordination. They are doing well 2 months post-operatively. Conclusion: A multidisciplinary team support with thorough preoperative planning significantly aids in improving the outcome of surgical separation. This has been possible by using modern technology. Each reported case contributes significantly to literature

30-Day Morbidity and Mortality of Bariatric Surgery During the COVID-19 Pandemic: a Multinational Cohort Study of 7704 Patients from 42 Countries.

BACKGROUND There are data on the safety of cancer surgery and the efficacy of preventive strategies on the prevention of postoperative symptomatic COVID-19 in these patients. But there is little such data for any elective surgery. The main objectives of this study were to examine the safety of bariatric surgery (BS) during the coronavirus disease 2019 (COVID-19) pandemic and to determine the efficacy of perioperative COVID-19 protective strategies on postoperative symptomatic COVID-19 rates. METHODS We conducted an international cohort study to determine all-cause and COVID-19-specific 30-day morbidity and mortality of BS performed between 01/05/2020 and 31/10/2020. RESULTS Four hundred ninety-nine surgeons from 185 centres in 42 countries provided data on 7704 patients. Elective primary BS (n = 7084) was associated with a 30-day morbidity of 6.76% (n = 479) and a 30-day mortality of 0.14% (n = 10). Emergency BS, revisional BS, insulin-treated type 2 diabetes, and untreated obstructive sleep apnoea were associated with increased complications on multivariable analysis. Forty-three patients developed symptomatic COVID-19 postoperatively, with a higher risk in non-whites. Preoperative self-isolation, preoperative testing for SARS-CoV-2, and surgery in institutions not concurrently treating COVID-19 patients did not reduce the incidence of postoperative COVID-19. Postoperative symptomatic COVID-19 was more likely if the surgery was performed during a COVID-19 peak in that country. CONCLUSIONS BS can be performed safely during the COVID-19 pandemic with appropriate perioperative protocols. There was no relationship between preoperative testing for COVID-19 and self-isolation with symptomatic postoperative COVID-19. The risk of postoperative COVID-19 risk was greater in non-whites or if BS was performed during a local peak