Safety, immunogenicity and efficacy of Relcovax®, a dual receptor binding domain (RBD) and nucleocapsid (N) subunit protein vaccine candidate against SARS-CoV-2 virus

SARS-CoV-2, severe acute respiratory syndrome coronavirus-2, causes coronavirus disease- 2019 (COVID-19). Mostly, COVID-19 causes respiratory symptoms that can resemble those of a cold, the flu, or pneumonia. COVID-19 may harm more than just lungs and respiratory systems. It may also have an impact on other parts of the body and debilitating effects on humans, necessitating the development of vaccines at an unprecedented rate in order to protect humans from infections. In response to SARS-CoV-2 infection, mRNA, viral vector-based carrier and inactivated virus-based vaccines, as well as subunit vaccines, have recently been developed. We developed Relcovax®, a dual antigen (Receptor binding domain (RBD) and Nucleocapsid (N) proteins) subunit protein vaccine candidate. Preliminary mouse preclinical studies revealed that Relcovax® stimulates cell-mediated immunity and provides broader protection against two SARS-CoV-2 variants, including the delta strain. Before conducting human studies, detailed preclinical safety assessments are required, so Relcovax® was tested for safety, and immunogenicity in 28-day repeated dose toxicity studies in rats and rabbits. In the toxicity studies, there were no mortality or morbidity, abnormal clinical signs, abnormalities in a battery of neurobehavioral observations, abnormalities in detailed clinical and ophthalmological examinations, or changes in body weights or feed consumption. In any of the studies, no abnormal changes in organ weights, haematology, clinical chemistry, urinalysis parameters, or pathological findings were observed. Immunogenicity tests on rats and rabbits revealed 100 % seroconversion. Relcovax® was therefore found to be safe in animals, with a No Observed Adverse Effect Level (NOAEL) of 20 µg/protein in rats and rabbits. In efficacy studies, Relcovax® immunised hamsters demonstrated dose-dependent protection against SARS-CoV-2 infection, with a high dose (20 µg/protein) being the most protective, while in cynomolgus macaque monkey study, lowest dose 5 µg/protein had the highest efficacy. In conclusion, Relcovax® was found to be safe, immunogenic, and efficacious in in vivo studies.

Exploring the Role of Simulation Training in Improving Surgical Skills Among Residents: A Narrative Review

The role of simulation in medical education is crucial to the development of surgeons' skills. Surgical simulation can be used to improve surgical skills in a secure and risk-free environment. Animal models, simulated patients, virtual reality, and mannequins are some types of surgical simulation. As a result, feedback encourages students to reflect on their strengths and weaknesses, enabling them to focus on improvement. Healthcare simulation is a strong educational instrument, and the main goal of this is to give the students an opportunity to do a practical application of what they have learned through theory. Before taking it to the patients, they will already have certain tools they have previously acquired during the practice. This makes it easier for students to identify the knowledge gaps that they must fill to improve patient outcomes. Moreover, simulation brings a wonderful opportunity for students to acquire skills, gain confidence, and experience success before working with real patients, especially when their clinical exposure is limited. The use of simulation to teach technical skills to surgical trainees has become more prevalent. The cost of setting up a simulation lab ranges from $100,000 to $300,000. There are several ways to evaluate the effectiveness of simulation-based surgical training. Repetitive surgical simulation training can improve speed and fluidity in general surgical skills in comparison to conventional training. Few previous studies compared learners who received structured simulation training to a group of trainees who did not receive any simulation training in single-center randomized control research. Significantly faster and less time-consuming skill proficiency was noticeable in simulated trainees. Despite being anxious in the operating room for the first time, simulated trainees completed the surgery on time, demonstrating the effectiveness of surgical simulation training. Traditional surgical training involves senior-surgeon supervision in the operating room. In simulation-based training, the trainees have full control over clinical scenarios and settings; however, guidance and assessment are also crucial. Simulators allow users to practice tasks under conditions resembling real-life scenarios. Simulators can be compared with traditional surgical training methods for different reasons. For example, intraoperative bleeding may occasionally show up not only visibly on the screen but also by shaking the trocars erratically. Without haptics, training on virtual simulators can cause one's pulling and pushing forces, which are frequently greater than what the tissue needs, to be distorted. A good method of simulation training is using virtual reality simulators with haptics and simulated patients. The availability of these facilities is limited, though, and a typical session might include an exercise involving stacking sugar cubes and box trainers. The degree of expertise or competency is one area that needs clarification as medical education transitions to a competency-based paradigm. The article aims to provide an overview of simulation, methods of simulation training, and the key role and importance of surgical simulation in improving skills in surgical residents.

RelCoVax®, a two antigen subunit protein vaccine candidate against SARS-CoV-2 induces strong immune responses in mice

The COVID-19 pandemic has spurred an unprecedented movement to develop safe and effective vaccines against the SARS-CoV-2 virus to immunize the global population. The first set of vaccine candidates that received emergency use authorization targeted the spike (S) glycoprotein of the SARS-CoV-2 virus that enables virus entry into cells via the receptor binding domain (RBD). Recently, multiple variants of SARS-CoV-2 have emerged with mutations in S protein and the ability to evade neutralizing antibodies in vaccinated individuals. We have developed a dual RBD and nucleocapsid (N) subunit protein vaccine candidate named RelCoVax® through heterologous expression in mammalian cells (RBD) and E. coli (N). The RelCoVax® formulation containing a combination of aluminum hydroxide (alum) and a synthetic CpG oligonucleotide as adjuvants elicited high antibody titers against RBD and N proteins in mice after a prime and boost dose regimen administered 2 weeks apart. The vaccine also stimulated cellular immune responses with a potential Th1 bias as evidenced by increased IFN-γ release by splenocytes from immunized mice upon antigen exposure particularly N protein. Finally, the serum of mice immunized with RelCoVax® demonstrated the ability to neutralize two different SARS-CoV-2 viral strains in vitro including the Delta strain that has become dominant in many regions of the world and can evade vaccine induced neutralizing antibodies. These results warrant further evaluation of RelCoVax® through advanced studies and contribute towards enhancing our understanding of multicomponent subunit vaccine candidates against SARS-CoV-2.

Ganglion cyst arising from the transverse acetabular ligament (TAL): a rare cause of entrapment of the anterior branch of the obturator nerve. Case report and review of the literature

The transverse acetabular ligament is an unusual location for ganglion cysts. Only a few cases have been reported in the literature. They can be asymptomatic and represent an incidental finding or can cause an atypical pattern of hip joint/groin pain. We report a case of ganglion cyst arising from the TAL causing entrapment of the anterior branch of the obturator nerve with associated acute denervation of the abductor longus (AL), adductor brevis (AB), and gracilis muscles.

Molecular mechanisms for the destabilization of model membranes by islet amyloid polypeptide

Misfolding of human islet amyloid polypeptide (hIAPP) into insoluble aggregates is associated with Type 2 diabetes. It has been suggested that hIAPP toxicity may be due to its accumulation in pancreatic islets, causing membrane disruption and cell permeabilization, however the molecular basis underlying its lipid association are still unclear. Here, we combine solid-state NMR, fluorescence and bright field microscopy to investigate hIAPP - lipid membrane interactions. Real-time microscopy highlights a time-dependent penetration of hIAPP oligomers toward the most buried layers of the lipid vesicles until the membrane disrupts. Deuterium NMR was conducted on liposomes at different hIAPP concentration to probe lipid internal order and thermotropism. The gel-to-fluid phase transition of the lipids is decreased by the presence of hIAPP, and site-specific analysis of the order parameter showed a significant increase of lipid order for the first eight positions of the acyl chain, suggesting a partial insertion of the peptide inside the bilayer. These results offer experimental insight into the membrane destabilization of hIAPP on model membrane vesicles.

siRNAs encapsulated in recombinant capsid protein derived from Dengue serotype 2 virus inhibits the four serotypes of the virus and proliferation of cancer cells

siRNA delivery potential of the Dengue virus capsid protein in cultured cells was recently reported, but target knockdown potential in the context of specific diseases has not been explored. In this study we have evaluated the utility of the protein as an siRNA carrier for anti Dengue viral and anti cancer applications using cell culture systems. We show that target specific siRNAs delivered using the capsid protein inhibit infection by the four serotypes of Dengue virus and proliferation of two cancer cell lines. Our data confirm the potential of the capsid for anti Dengue viral and anti cancer RNAi applications. In addition, we have optimized a fermentation strategy to improve the yield of Escherichia coli expressed D2C protein since the reported yields of E. coli expressed flaviviral capsid proteins are low.

Evaluation of target mRNA cleavage by aurorakinase B specific siRNA in prostate and hepatic cancer cells and its therapeutic potential in mouse models of liver cancer

The anti proliferative potential of siRNA26, targeted to Aurora kinase B, in prostate cancer cells is known from a previous study from our laboratory. Here we first show that siRNA26 cleaves at the same position of the target mRNA in the prostate cancer and hepatocellular carcinoma cell lines, PC3 and HepG2 respectively. Aurorakinase B specific siRNA, but not a control siRNA, inhibited PC3 and HepG2 cell proliferation and cell migration. These effects correlated to RNA silencing of Aurorakinase B in both the cell lines. Intra-tumoral administration of HiPerfect complexed siRNA26 inhibited the growth of HepG2 xenografts in SCID mice. In an orthotopic setting, intravenous administration of HiPerfect encapsulated siRNA26 appeared to reduce the severity of multifocal lesions.

Infant mouse brain passaged Dengue serotype 2 virus induces non-neurological disease with inflammatory spleen collapse in AG129 mice after splenic adaptation

AG129 mice are known to be permissive to infection by multiple serotypes of Dengue virus (DENV). There exists a concern that mouse passaged strains of the virus may induce neurological complications rather than increased vascular permeability in these mice, hence the use of human clinical isolates of the virus to develop the AG129 mouse model of Dengue disease with increased vascular permeability. The present study evaluated four mouse brain passaged DENV strains, each belonging to a different serotype and three of them having an original isolation history in India, for their suitability to serve as candidates to induce rapid lethal disease in AG129 mice. While all the viruses were able to establish a productive infection in the spleen, none of them induced paralysis despite their mouse brain passage history. Only the type-2 virus acquired the ability to induce a lethal disease after a single round of spleen to spleen passage, and became highly virulent after five more rounds. This apparently non-neurological lethal disease was characterized by high viral burden, elevated vascular permeability, serum TNF-α surge immediately before moribund stage, transient leukocytosis followed by severe leukopenia, lymphopenia throughout the course of the infection, and transient thrombocytopenia. The disease was also characterized by inflammatory splenic collapse during moribund stage, reminiscent of spontaneous splenic rupture reported in rare cases of severe Dengue in humans.

Erythrocyte ascorbic acid and plasma vitamin E status in patients with carcinoma of prostate

Prostate cancer is the most prevalent cancer found in men above the age of fifty years and is frequently diagnosed in men between 45 and 89 years of age with a median age of 72 years. This work was undertaken to assess oxidative stress and antioxidant status in patients with carcinoma of prostate. Erythrocyte ascorbic acid and plasma vitamin E levels were estimated in patients with carcinoma of prostate and compared to controls. It was observed that there was a significant decrease in Erythrocyte ascorbic acid and plasma vitamin E levels in patients with carcinoma of prostate compared to controls. The decrease in the levels of antioxidant vitamins may be due to the increased turnover for preventing the oxidative damage in these patients.

Hyperlipidemia, increased lipid peroxidation and changes in antioxidant enzymes, Na(+)-K(+)-ATPase in erythrocytes of type 2 diabetic patients in andhra pradesh

Plasma levels of lipids, lipoproteins and lipid peroxides and erythrocyte Na(+)-K(+) ATPase, Mg(2+)ATPase and antioxidant enzymes were measured in type-2 diabetic patients. A significant decrease in Na(+)-K(+)-ATPase activity was observed in diabetic patients which was negatively correlated with blood glucose and lipid peroxides, while the Mg(2+)-ATPase activity was increased. In the diabetic subjects the plasma concentrations of Na(+) and K(+) were increased where as erythrocyte levels of Na(+) were increased and K(+) were decreased. Hyperlipidaemia and increased levels of lipid peroxides were observed in the diabetic subjects. There was a significant increase in erythrocyte catalase activity in diabetics which positively correlated with their lipid peroxides. There was no change in GPx activities between controls and diabetics.