Collaborative international partnership: Enabling the development of a state-of-the-art minimally invasive surgical center in rural Uganda through telementoring.

BACKGROUND: Access to minimally invasive surgery (MIS) is limited in Sub-Saharan African countries. In 2019, the Mount Sinai Department of Surgery in New York collaborated with local Ugandans to construct the Kyabirwa Surgical Center (KSC), an independent, replicable, self-sustaining ambulatory surgical center in Uganda. We developed a focused MIS training program using a combination of in-person training and supervised telementoring. We present the results of our initial MIS telementoring experience. METHODS: We worked jointly with Ugandan staff to construct the KSC in the rural province of Jinja. A solar-powered backup battery system ensured continuous power availability. Underground fiber optic cables were installed to provide stable high-speed Internet. The local Ugandan general surgeon (JOD) underwent a mini-fellowship in MIS and then trained extensively using the Fundamentals of Laparoscopic Surgery program. After a weeklong in-person session to train the Ugandan OR team, JOD performed laparoscopic cases with telementoring, which was conducted remotely by surgeons in New York via audiovisual feeds from the KSC OR. RESULTS: From October 2021 to February 2024, JOD performed 61 telementored laparoscopic operations at KSC including 37 appendectomies and 24 cholecystectomies. Feedback was provided regarding patient positioning, port placement, surgical technique, instrument use, and critical steps of the operation. There were no intra-operative complications. Postoperatively, field medical workers visited patients at home to collect follow-up information. Two superficial wound infections (3.3%) were reported in the short-term follow-up. CONCLUSION: Telementoring can be safely implemented to assist surgeons in previously underserved areas to provide advanced laparoscopic surgical care to the local patient population.

Group A Streptococcus Pili-Roles in Pathogenesis and Potential for Vaccine Development.

The Gram-positive human pathogen Group A Streptococcus (GAS, Streptococcus pyogenes) employs an arsenal of virulence factors that contribute to its pathogenesis. The pilus is an important factor that enables the pathogen to adhere to and colonize host tissues. Emerging research in pilus function shows that pili's involvement in establishing infection extends beyond host adhesion. The diversity of GAS pilus types reflect the varying characteristics identified in different pili. With the development of new experimental systems and animal models, a wider range of biological functions have been explored. This brief review summarizes recent reports of new functions in different GAS pilus types and the methodologies that contributed to the findings. The established importance of the pilus in GAS pathogenesis makes this surface structure a promising vaccine target. This article also reviews recent advancements in pilus-based vaccine strategies and discusses certain aspects that should be considered in vaccine development according to the newly defined properties of pili.

Different Group A Streptococcus pili lead to varying proinflammatory cytokine responses and virulence.

The human pathogen Streptococcus pyogenes, or Group A Streptococcus (GAS), is associated with a variety of diseases ranging from mild skin and soft tissue infections to invasive diseases and immune sequelae such as rheumatic heart disease. We have recently reported that one of the virulence factors of this pathogen, the pilus, has inflammatory properties and strongly stimulates the innate immune system. Here we used a range of nonpathogenic Lactococcus lactis gain-of-function mutants, each expressing one of the major pilus types of GAS, to compare the immune responses generated by various types of fully assembled pili. In vitro assays indicated variability in the inflammatory response induced by different pili, with the fibronectin-binding, collagen-binding, T antigen (FCT)-1-type pilus from GAS serotype M6/T6 inducing significantly stronger cytokine secretion than other pili. Furthermore, we established that the same trend of pili-mediated immune response could be modeled in Galleria mellonella larvae, which possess a similar innate immune system to vertebrates. Counterintuitively, across the panel of pili types examined in this study, we observed a negative correlation between the intensity of the immune response demonstrated in our experiments and the disease severity observed clinically in the GAS strains associated with each pilus type. This observation suggests that pili-mediated inflammation is more likely to promote bacterial clearance instead of causing disruptive damages that intensify pathogenesis. This also indicates that pili may not be the main contributor to the inflammatory symptoms seen in GAS diseases. Rather, the immune-potentiating properties of the pilus components could potentially be exploited as a vaccine adjuvant.

Mucosal vaccination: onward and upward.

INTRODUCTION: The unique mucosal immune system allows the generation of robust protective immune responses at the front line of pathogen encounters. The needle-free delivery route and cold chain-free logistic requirements also provide additional advantages in ease and economy. However, the development of mucosal vaccines faces several challenges, and only a handful of mucosal vaccines are currently licensed. These vaccines are all in the form of live attenuated or inactivated whole organisms, whereas no subunit-based mucosal vaccine is available. AREAS COVERED: The selection of antigen, delivery vehicle, route and adjuvants for mucosal vaccination are highly important. This is particularly crucial for subunit vaccines, as they often fail to elicit strong immune responses. Emerging research is providing new insights into the biological and immunological uniqueness of mucosal tissues. However, many aspects of the mucosal immunology still await to be investigated. EXPERT OPINION: This article provides an overview of the current understanding of mucosal vaccination and discusses the remaining knowledge gaps. We emphasize that because of the potential benefits mucosal vaccines can bring from the biomedical, social and economic standpoints, the unmet goal to achieve mucosal vaccine success is worth the effort.

Sleeve gastrectomy facilitates weight loss and permits cardiac transplantation in patients with severe obesity and a left ventricular assist device (LVAD).

INTRODUCTION: Patients suffering from advanced heart failure may undergo left ventricular assist device (LVAD) placement as a bridge to cardiac transplantation. However, those with a BMI above 35 kg/m2 are generally not considered eligible for transplant due to their elevated cardiac risk. We review our experience with bariatric surgery in this high-risk population to assess its safety and efficacy in reducing BMI to permit cardiac transplantation. METHODS: We retrospectively reviewed all patients on durable LVAD support who underwent sleeve gastrectomy (SG) at Mount Sinai Hospital between August 2018 and December 2022. Electronic medical records were reviewed to analyze patient demographics, surgical details, and outcomes regarding weight loss and heart transplantation. RESULTS: We identified twelve LVAD patients who underwent SG. Three were performed laparoscopically and 9 via robotic approach. Four patients (33.3%) underwent an orthotopic heart transplant (OHTx). Half of these patients were female. For patients who underwent OHTx, mean age at LVAD placement was 41.0 (R30.6-52.2), at SG was 43.9 (R32.7-55.0) and at OHTx was 45.3 years (R33.3-56.8). Mean BMI increased from 38.8 at LVAD placement to 42.5 prior to SG. Mean time from SG to OHTx was 17.9 months (R6-7-27.5) during which BMI decreased to mean 32.8 at the time of OHTx. At most recent follow-up, mean BMI was 31.9. All patients were anticoagulated prior to surgery; one required return to the operating room on post-operative day 1 after SG for bleeding and one was re-admitted on post-operative day 7 for hematochezia treated conservatively. CONCLUSION: SG is a safe and effective operation in patients with severe obesity and heart failure requiring an LVAD. 66.7% of our cohort achieved target BMI < 35 and 33.3% underwent heart transplantation. Longer term follow-up is needed to clarify full bridge-to-transplant rate and long-term survival outcomes.

Regenerative Peripheral Nerve Interface Surgery: Anatomic and Technical Guide.

Regenerative peripheral nerve interface (RPNI) surgery has been demonstrated to be an effective tool as an interface for neuroprosthetics. Additionally, it has been shown to be a reproducible and reliable strategy for the active treatment and for prevention of neuromas. The purpose of this article is to provide a comprehensive review of RPNI surgery to demonstrate its simplicity and empower reconstructive surgeons to add this to their armamentarium. This article discusses the basic science of neuroma formation and prevention, as well as the theory of RPNI. An anatomic review and discussion of surgical technique for each level of amputation and considerations for other etiologies of traumatic neuromas are included. Lastly, the authors discuss the future of RPNI surgery and compare this with other active techniques for the treatment of neuromas.

The Impact of Age in the Treatment of Non-comorbid Patients with Rectal Cancer: Survival Outcomes from the National Cancer Database.

BACKGROUND: Multimodal therapy has improved survival outcomes for rectal cancer (RC) significantly with an exemption for older patients. We sought to assess whether older non-comorbid patients receive substandard oncological treatment for localized RC referring to the National Comprehensive Cancer Network (NCCN) guidelines and whether it affects survival outcomes. METHODS: This is a retrospective study using patient data from the National Cancer Data Base (NCDB) for histologically confirmed RC from 2002 to 2014. Non-comorbid patients between ≥50 and ≤85 years and defined treatment for localized RC were included and assigned to a younger (<75 years) and an older group (≥75 years). Treatment approaches and their impact on relative survival (RS) were analyzed using loess regression models and compared between both groups. Furthermore, mediation analysis was performed to measure the independent relative effect on age and other variables on RS. Data were assessed using the Strengthening the Reporting of Observational studies in Epidemiology (STROBE) checklist. RESULTS: Of 59,769 included patients, 48,389 (81.0%) were assigned to the younger group (<75 years). Oncologic resection was performed in 79.6% of the younger patients compared to 67.2% of the older patients (p < 0.001). Chemotherapy (74.3% vs. 56.1%) and radiotherapy (72.0% vs. 58.1%) were provided less often in older patients, respectively (p < 0.001). Increasing age was associated with enhanced 30- and 90-day mortality with 0.6% and 1.1% in the younger and 2.0% and 4.1% in the elderly group (p < 0.001) and worse RS rates [multivariable adjusted HR: 1.93 (95% CI 1.87-2.00), p < 0.001]. Adherence to standard oncological therapy resulted in a significant increase in 5-year RS (multivariable adjusted HR: 0.80 (95% CI 0.74-0.86), p < 0.001). Mediation analysis revealed that RS was mainly affected by age itself (84%) rather than the choice of therapy. CONCLUSIONS: The likelihood to receive substandard oncological therapy increases in the older population and negatively affects RS. Since age itself has a major impact on RS, better patient selection should be performed to identify those that are potentially eligible for standard oncological care regardless of their age.

Expanding strain coverage of a group A Streptococcus pilus-expressing Lactococcus lactis mucosal vaccine.

Group A Streptococcus (GAS) is a human pathogenic bacterium that can trigger a wide range of diseases, including the autoimmune diseases acute rheumatic fever and rheumatic heart disease, causing major morbidity and mortality in many low- and middle-income countries. Primary intervention programs have had limited success thus far, and a licensed vaccine has yet to be developed. The pilus of GAS is known to be involved in host cell adhesion, biofilm formation and immune evasion. We have a mucosal vaccine in development that expresses the pilus of GAS on the surface of the nonpathogenic bacterium Lactococcus lactis. To expand strain coverage, we combined seven L. lactis constructs, each expressing a different GAS pilus variant, and investigated the systemic and mucosal immune responses following immunization. Mice immunized with this combination showed specific immunoglobin G and immunoglobin A responses to the GAS pilus proteins of vaccine strains, at levels comparable to mice immunized with a single construct. Cross-reactivity to pilus proteins of nonvaccine strains was also evident. Furthermore, protective efficacy against a homologous strain of GAS in a murine nasopharyngeal colonization model was observed. Overall, this study provides further evidence for using pilus-expressing lactic acid bacteria as a vaccine to prevent upper respiratory tract GAS infections.

The Cell Wall Deacetylases Spy1094 and Spy1370 Contribute to Streptococcus pyogenes Virulence.

Streptococcus pyogenes, or Group A Streptococcus (GAS), is a strictly human pathogen that causes a wide range of diseases, including skin and soft tissue infections, toxic shock syndrome and acute rheumatic fever. We have recently reported that Spy1094 and Spy1370 of S. pyogenes serotype M1 are N-acetylglucosamine (GlcNAc) deacetylases. We have generated spy1094 and spy1370 gene deletion mutants in S. pyogenes and gain-of-function mutants in Lactococcus lactis. Similar to other cell wall deacetylases, our results show that Spy1094 and Spy1370 confer lysozyme-resistance. Furthermore, deletion of the genes decreased S. pyogenes virulence in a human whole blood killing assay and a Galleria mellonella (Greater wax moth) larvae infection model. Expression of the two genes in L. lactis resulted in increased lysozyme resistance and survival in whole human blood, and reduced survival of infected G. mellonella larvae. Deletion of the spy1370, but not the spy1094 gene, decreased resistance to the cationic antimicrobial peptide cecropin B, whereas both enzymes increased biofilm formation, probably resulting from the increase in positive charges due to deacetylation of the cell wall. In conclusion, Spy1094 and Spy1370 are important S. pyogenes virulence factors and might represent attractive targets for the development of antibacterial agents.

Prognostic Significance of Severe Vitamin D Deficiency in Patients with Primary Sclerosing Cholangitis.

Vitamin D deficiency has been linked with adverse events in various liver diseases. The present study aimed to recognize the association between severe vitamin D deficiency and disease progression, hepatobiliary malignancies, liver-related mortality, and the need for liver transplantation in primary sclerosing cholangitis (PSC). Patients with a diagnosis of PSC (n = 354), followed by the autoimmune liver disease clinic at the University of Alberta, were included. Patients with vitamin D levels < 25 nmol/L were defined as severely deficient. Univariate and multivariate analyses were conducted using the Cox proportional hazards regression models. The mean vitamin D level was 59 ± 2 nmol/L, and 63 patients (18%) had a severe vitamin D deficiency. Patients with a severe vitamin D deficiency were 2.5 times more likely to experience hepatobiliary malignancies (HR 2.55, 95% CI, 1.02-6.40, p = 0.046). A severe vitamin D deficiency at diagnosis (HR 1.82, 95% CI, 1.05-3.15, p = 0.03) and persistent deficiencies over time (HR 2.26, 95% CI, 1.17-4.37, p = 0.02) were independently associated with a higher risk of poor clinical liver outcomes. A severe vitamin D deficiency at diagnosis and persistent deficiency at longitudinal assessments were associated with liver-related mortality or the need for liver transplantation.

REMIT-UC: Real-World Effectiveness and Safety of Tofacitinib for Moderate-to-Severely Active Ulcerative Colitis: A Canadian IBD Research Consortium Multicenter National Cohort Study.

INTRODUCTION: We aimed to evaluate the real-world effectiveness and safety of tofacitinib for the treatment of ulcerative colitis (UC). METHODS: REMIT-UC is a Canadian multicenter cohort study. Standardized data collection was performed on 334 consecutive adult outpatients with UC treated with tofacitinib. The primary outcomes were achievement of clinical and endoscopic remission. Safety outcomes were reported using incidence rates (events/100 patient-years of exposure). A multivariable Cox proportional hazards model was used to evaluate predictors of loss of response after tofacitinib dose de-escalation to 5 mg twice daily (BID). RESULTS: Clinical remission was achieved by 35.3% (106/300), 36.0% (104/289), and 35.2% (93/264) of patients at weeks 12, 24, and 52, respectively. Endoscopic remission was achieved by 18.5% (15/81), 23.0% (28/122), and 25.7% (35/136) of patients at weeks 12, 24, and 52, respectively. Incidence of serious infections, herpes zoster, and venous thromboembolism were 2.1 [0.9-4.2], 0.5 [0.1-1.9], and 1.1 [0.3-2.7], respectively. Among responders, 44.5% (109/245) lost response during follow-up, which was recaptured in 54.9% (39/71) of patients who re-escalated to 10 mg BID. Patients with a baseline Mayo endoscopic score of 3 (adjusted hazard ratio 3.60 [95% confidence interval: 1.70-7.62]) and prior biologic failure (adjusted hazard ratio 3.89 [95% confidence interval: 1.28-11.86]) were at a higher risk for losing response after dose reduction. DISCUSSION: One-third of patients with UC treated with tofacitinib achieved clinical remission with few serious adverse events. However, half of patients lost response with de-escalation, which was only partially recaptured with increasing the maintenance dose. Those with negative prognostic factors should be counselled about the risks and benefits of continuing high doses of tofacitinib.

Prevalence and Severity of Burn Scars in Rural Mozambique.

BACKGROUND: Burn injuries are common in low- and middle-income countries (LMICs) and their associated disability is tragic. This study is the first to explore burn scars in rural communities in Mozambique. This work also validated an innovate burn assessment tool, the Morphological African Scar Contractures Classification (MASCC), used to determine surgical need. METHODS: Using a stratified, population-weighted survey, the team interviewed randomly selected households from September 2012 to June 2013. Three rural districts (Chókwè, Nhamatanda, and Ribáuè) were selected to represent the southern, central and northern regions of the country. Injuries were recorded, documented with photographs, and approach to care was gathered. A panel of residents and surgeons reviewed the burn scar images using both the Vancouver Scar Scale and the MASCC, a validated visual scale that categorizes patients into four categories corresponding to levels of surgical intervention. RESULTS: Of the 6104 survey participants, 6% (n = 370) reported one or more burn injuries. Burn injuries were more common in females (57%) and most often occurred on the extremities. Individuals less than 25 years old had a significantly higher odds of reporting a burn scar compared to people older than 45 years. Based on the MASCC, 12% (n = 42) would benefit from surgery to treat contractures. CONCLUSION: Untreated burn injuries are prevalent in rural Mozambique. Our study reveals a lack of access to surgical care in rural communities and demonstrates how the MASCC scale can be used to extend the reach of surgical assessment beyond the hospital through community health workers.

Pilus proteins from Streptococcus pyogenes stimulate innate immune responses through Toll-like receptor 2.

The group A Streptococcus (GAS) pilus is a long, flexible, hair-like structure anchored to the cell surface that facilitates the adherence of GAS to host cells, thus playing a critical role in initiating infections. Because of its important role in GAS virulence, the pilus has become an attractive target for vaccine development. While current research mainly focuses on pilus function and its potential as a vaccine component, there is a lack of knowledge on how the host immune system recognizes and responds to this abundant surface structure. Here we show that both assembled GAS pili and individual pilus proteins induce a potent release of the proinflammatory cytokines tumor necrosis factor and interleukin-8. We further show that the surface-exposed backbone pilin and ancillary pilin 1 subunits are Toll-like receptor 2 (TLR2) agonists. Using reporter cell lines coexpressing human TLR2 in combination with either TLR1 or TLR6, we determined that activation was mediated by the TLR2/TLR6 heterodimer. Finally, we used solid-phase and flow cytometry binding assays to illustrate a direct interaction between the pilus subunits and TLR2. These results provide further support for the suitability of the pilus as a vaccine component and opens potential avenues for using GAS pili as an adjuvant or immune-modulation agent.

Insufficient weight loss after banded vs. non-banded primary gastric bypass surgery: insights from an observational 5 year follow-up study.

BACKGROUND: While Roux-en-Y gastric bypass (RYGB) is effective in achieving weight loss and improving obesity-related co-morbidities, insufficient weight loss in the long-term can occur. The goal was to assess whether banded vs. non-banded RYGB reduces the risk of insufficient weight loss at 5-year follow-up. METHODS: This is a retrospective single-center cohort study from Switzerland. We assessed the 5-year metabolic trajectories in terms of body weight, body mass index, glucose control, lipid profile and blood pressure of two surgical cohorts undergoing identical RYGB procedures with or without banding using a uniform 6.5 cm silastic Fobi band. Insufficient weight loss was defined as < 50% excess weight loss (EWL) at 5 years. RESULTS: A total of 55 patients receiving banded (Fobi) and 55 patients receiving non-banded (non-Fobi) RYGB were included in the analysis. 5-year follow-up was 91% for both groups. Percentage of EWL at 5 years was 78.11 ± 26.1% and 73.5 ± 27%.3 for the Fobi vs. non-Fobi group (p = 0.368), respectively. Insufficient weight loss (defined as < 50%EWL) at 5 years or last follow-up was significantly higher in the non-Fobi group compared to the Fobi group (19/55 vs. 9/55, respectively, OR = 2.639 (95% CI 1.066, 6.531), p = 0.036). Surrogate markers for cardiometabolic outcomes consistently improved over time, without differences between the groups. During the follow-up period, Fobi-removal was necessary in nine patients (16.3%). CONCLUSION: Banded-RYGB lowered the odds of insufficient weight loss at 5 years follow-up by approximately 62%. Further research is needed to explore the effect of restriction on eating behaviour and neuroendocrine responses after RYGB.

PilVax: A Novel Platform for the Development of Mucosal Vaccines.

Peptide vaccines offer an attractive strategy to induce highly specific immune responses while reducing potential side effects. However, peptides are often poorly immunogenic and unstable on their own, requiring the need for potentially toxic adjuvants or expensive chemical coupling. The novel peptide delivery platform PilVax utilizes the rigid pilus structure from Group A Streptococcus (GAS) to stabilize and amplify the peptide, and present it on the surface of the non-pathogenic food-grade bacterium Lactococcus lactis. Upon intranasal immunization, PilVax vaccines have proven to induce peptide-specific systemic and mucosal responses. PilVax provides an alternative method to develop mucosal vaccines that are inexpensive to produce and easy to administer.

Downregulation of Ribosomal Contents and Kinase Activities Is Associated with the Inhibitive Effect on the Growth of Group B Streptococcus Induced by Placental Extracellular Vesicles.

BACKGROUND: Like many other cell types, the human placenta produces large amounts of extracellular vesicles (EVs). Increasing evidence has shown that placental EVs contribute to the regulation of maternal immune and vascular systems during pregnancy via the transfer of their cargos. In this study, we investigated the effect of placental EVs on the growth of opportunistic pathogens that commonly colonise the female reproductive tract. METHODS: Gram-positive bacterium Group B Streptococcus (GBS) and Gram-negative bacterium Escherichia coli (E. coli) were treated with placental EVs that were collected from placental explant cultures, and the growth, susceptibility, and resistance to antibiotics of the bacteria were measured. In addition, comparative proteomics analysis was also performed for the GBS with or without exposure to placental EVs. RESULTS: When treated with placental micro-EVs or nano-EVs, the GBS growth curve entered the stationary phase earlier, compared to untreated GBS. Treatment with placental EVs also inhibited the growth of GBS on solid medium, compared to untreated GBS. However, these biological activities were not seen in E. coli. This attenuative effect required interaction of placental EVs with GBS but not phagocytosis. In addition, the susceptibility or resistance to antibiotics of GBS or E. coli was not directly affected by treatment with placental EVs. The proteomic and Western blotting analysis of GBS that had been treated with placental EVs suggested that the downregulation of cellular components and proteins associated with phosphorylation and cell energy in GBS may contribute to these attenuative effects. CONCLUSION: We demonstrated the attenuative effect of the growth of GBS treated with placental EVs. Downregulation of cellular components and proteins associated with phosphorylation and cell energy may contribute to the physiological changes in GBS treated with placental EVs.

How to Get Consistently Good Results in Cleft Lip Repair.

This article serves as a practical guide for plastic surgeons focusing on repair of primary cleft lip and nasal deformity. We discuss the key anatomic disruption present in cleft lip and nasal deformity and the goals of primary repair. In addition, our preferred surgical technique for unilateral and bilateral cleft lip and nasal deformity is summarized along with technical pearls and pitfalls.

Presence of Donor Lymph Nodes Within Vascularized Composite Allotransplantation Ameliorates VEGF-C-mediated Lymphangiogenesis and Delays the Onset of Acute Rejection.

BACKGROUND: The lymphatic system plays an active role in modulating inflammation in autoimmune diseases and organ rejection. In this work, we hypothesized that the transfer of donor lymph node (LN) might be used to promote lymphangiogenesis and influence rejection in vascularized composite allotransplantation (VCA). METHODS: Hindlimb transplantations were performed in which (1) recipient rats received VCA containing donor LN (D:LN+), (2) recipient rats received VCA depleted of all donor LN (D:LN-), and (3) D:LN+ transplantations were followed by lymphangiogenesis inhibition using a vascular endothelial growth factor receptor-3 (VEGFR3) blocker. RESULTS: Our data show that graft rejection started significantly later in D:LN+ transplanted rats as compared to the D:LN- group. Moreover, we observed a higher level of VEGF-C and a quicker and more efficient lymphangiogenesis in the D:LN+ group as compared to the D:LN- group. The presence of donor LN within the graft was associated with reduced immunoactivation in the draining LN and increased frequency of circulating and skin-resident donor T regulatory cells. Blocking of the VEGF-C pathway using a VEGFR3 blocker disrupts the lymphangiogenesis process, accelerates rejection onset, and interferes with donor T-cell migration. CONCLUSIONS: This study demonstrates that VCA LNs play a pivotal role in the regulation of graft rejection and underlines the potential of specifically targeting the LN component of a VCA to control graft rejection.

Intranasal immunization with Ag85B peptide 25 displayed on Lactococcus lactis using the PilVax platform induces antigen-specific B- and T-cell responses.

Mycobacterium tuberculosis (Mtb) remains a global epidemic despite the widespread use of Bacillus Calmette-Guérin (BCG). Consequently, novel vaccines are required to facilitate a reduction in Mtb morbidity and mortality. PilVax is a peptide delivery strategy for the generation of highly specific mucosal immune responses and is based on the food-grade bacterium Lactococcus lactis that is used to express selected peptides engineered within the Streptococcus pyogenes M1T1 pilus, allowing for peptide amplification, stabilization and enhanced immunogenicity. In the present study, the dominant T-cell epitope from the Mtb protein Ag85B was genetically engineered into the pilus backbone subunit and expressed on the surface of L. lactis. Western blot and flow cytometry confirmed formation of pilus containing the peptide DNA sequence. B-cell responses in intranasally vaccinated mice were analyzed by ELISA while T-cell responses were analyzed by flow cytometry. Serum titers of peptide-specific immunoglobulin (Ig) G and IgA were detected, confirming that vaccination produced antibodies against the cognate peptide. Peptide-specific IgA was also detected across several mucosal sites sampled. Peptide-specific CD4+ T cells were detected at levels similar to those of mice immunized with BCG. PilVax immunization resulted in an unexpected increase in the numbers of CD3+ CD4- CD8- [double negative (DN)] T cells in the lungs of vaccinated mice. Analysis of cytokine production following stimulation with the cognate peptide showed the major cytokine producing cells to be CD4+ T cells and DN T cells. This study provides insight into the antibody and peptide-specific cellular immune responses generated by PilVax vaccination and demonstrates the suitability of this vaccine for conducting a protection study.

Mixed Metal Oxide Nanoparticle Formulations for the Treatment of Seroma.

Seroma formation is a well-recognized postoperative complication for many plastic and general surgical procedures. Although various tissue adhesives and substances have been used in an effort to treat seroma formation, no therapies have been established clinically. Recently, the nano-bridging phenomenon has been introduced as a promising approach to achieve tissue adhesion and strong closure of deep skin wounds in rats. The present study seeks to assess the potential of nano-bridging beyond skin wounds in a rat model of seroma. Seromas were induced in 20 Lewis rats through bilateral axillary lymphadenectomy, excision of the latissimus dorsi and cutaneous maximus muscles, and disruption of dermal lymphatics. On postoperative day (POD) 7, the seroma was aspirated on both sides. A bioactive nanoparticle (NP) suspension based on zinc-doped strontium-substituted bioglass/ceria nanoparticles (NP group) or fibrin glue (fibrin group) was injected into the right seroma cavity, while the left side was left untreated. On POD 14, the NP group showed complete remission (no seromas at all), while the fibrin group recorded a reduction of only 63% in the seroma fluid volume. The NPs exerted local anti-inflammatory and neo-angiogenic effects, without any detectable systemic changes. Moreover, the ceria levels recorded in the organs did not surpass the background level, indicating that the nanoparticles stayed at the site of application. This study is a promising first example demonstrating the ability of inorganic nanoparticle formulations to reduce seroma formation in a rat model, without any detectable systemic adverse effects. These results emphasize the potential of nanotechnological solutions in the therapeutic management of seroma in the clinical setting.