RBD decorated PLA nanoparticle admixture with aluminum hydroxide elicit robust and long lasting immune response against SARS-CoV-2.

Nanoparticles-based multivalent antigen display has the capability of mimicking natural virus infection characteristics, making it useful for eliciting potent long-lasting immune response. Several vaccines are developed against global pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). However these subunit vaccines use mammalian expression system, hence mass production with rapid pace is a bigger challenge. In contrast E. coli based subunit vaccine production circumvents these limitations. The objective of the present investigation was to develop nanoparticle vaccine with multivalent display of receptor binding domain (RBD) of SARS-CoV-2 expressed in E. coli. Results showed that RBD entrapped PLA (Poly lactic acid) nanoparticle in combination with aluminum hydroxide elicited 9-fold higher immune responses as compared to RBD adsorbed aluminum hydroxide, a common adjuvant used for human immunization. It was interesting to note that RBD entrapped PLA nanoparticle with aluminum hydroxide not only generated robust and long-lasting antibody response but also provided Th1 and Th2 balanced immune response. Moreover, challenge with 1 µg of RBD alone was able to generate secondary antibody response, suggesting that immunization with RBD-PLA nanoparticles has the ability to elicit memory antibody against RBD. Plaque assay revealed that the antibody generated using the polymeric formulation was able to neutralize SARS-CoV-2. The RBD entrapped PLA nanoparticles blended with aluminum hydroxide thus has potential to develop asa subunit vaccine against COVID-19.

Pulmonary Dysfunction in Transfusion-Dependent Thalassemia and Response to Intensive Chelation Therapy.

OBJECTIVE: To evaluate pulmonary functions in children with transfusion-dependent thalassemia, and its reversal (lung dysfunction) using intensive intravenous chelation with desferrioxamine (DFO) (4 weeks). METHODS: This descriptive study enrolled 77 children with transfusion-dependent thalassemia. Pulmonary function test (PFT) and iron load (serum ferritin (SF) and T2* MRI of heart and liver) were done. PFT included spirometry, total lung capacity (TLC) by helium dilution test and diffusion capacity by carbon monoxide (DLCO). Follow-up PFT was available for 13 children with moderate to severe lung dysfunction given intravenous DFO. RESULTS: 50 (68.8%) patients had lung dysfunction, most commonly diffusional impairment (48; 96%), and reduced TLC (11; 22%); and none had obstructive pattern. 9 (81.8%) patients with restrictive defect had moderate to severely deranged DLCO. PFT and T2* MRI values were inversely correlated with serum ferritin. Among 13 patients receiving intensive chelation for 4 weeks, significant improvement was noticed in forced expiratory volume in one minute/ forced vital capacity ratio (DFEV1/FVC) (P=0.009), DDLCO (P=0.006) and DSF (P=0.01). CONCLUSIONS: Pulmonary dysfunction is common in children with multi-transfused thalassemia, and routine screening by PFT needs to be part of the management guidelines.

Saving oxygen when it was most needed.

Background: Oxygen is one of the most commonly prescribed drugs across the globe. The ongoing Covid-19 pandemic has put enormous burden on hospital infrastructure and oxygen demand. There is lack of knowledge among healthcare workers regarding optimal utilization of oxygen delivery devices, target oxygen saturations and adequate oxygen prescription. A quality improvement project was designed to optimize the oxygen usage in wards. Methods: A core team comprising one each of consultant, senior resident, junior resident and nursing officer was formed. Fish bone analysis was done to find deficiencies in the existing system and strategy was planned to overcome these deficiencies. The key intervention included education and training of staff, Formulation of Standard Operating Procedures, use of lower target oxygen saturation and use of oxygen concentrators. Results: The project was carried out for a very short period of 5 days, and a total of 180,000 liters of oxygen was saved. The use of oxygen concentrators increased from zero to 9.5% and thus reducing the load on central oxygen supply. Conclusion: The proper training and sensitization of health care workers can help in saving oxygen, which further helps in saving precious human life.

Molecular Attributes Associated With Refolding of Inclusion Body Proteins Using the Freeze-Thaw Method.

Understanding the structure-function of inclusion bodies (IBs) in the last two decades has led to the development of several mild solubilization buffers for the improved recovery of bioactive proteins. The recently developed freeze-thaw-based inclusion body protein solubilization method has received a great deal of attention due to its simplicity and cost-effectiveness. The present report investigates the reproducibility, efficiency, and plausible mechanism of the freeze-thaw-based IB solubilization. The percentage recovery of functionally active protein species of human growth hormone (hGH) and L-asparaginase from their IBs in Escherichia coli and the quality attributes associated with the freeze-thaw-based solubilization method were analyzed in detail. The overall yield of the purified hGH and L-asparaginase protein was found to be around 14 and 25%, respectively. Both purified proteins had functionally active species lower than that observed with commercial proteins. Biophysical and biochemical analyses revealed that the formation of soluble aggregates was a major limitation in the case of tough IB protein like hGH. On the other hand, the destabilization of soft IB protein like L-asparaginase led to the poor recovery of functionally active protein species. Our study provides insight into the advantages, disadvantages, and molecular-structural information associated with the freeze-thaw-based solubilization method.

Central pontine myelinolysis presenting with tremor in a child with celiac disease.

A 4-year-old boy presented with a history of tremor for 7 days. He also had recurrent diarrhea for the previous 1 year, and poor weight gain. Magnetic resonance of the brain was suggestive of central pontine myelinolysis. There was no evidence of electrolyte abnormalities. The serum tissue transglutaminase level was markedly elevated, and the duodenal biopsy revealed features of celiac disease. The patient was started on gluten-free diet. The tremor resolved within 3 months. Repeat imaging of the brain done 3 months after starting gluten-free diet showed complete resolution of the lesion. This case highlights the unusual presentation of central pontine myelinosis as tremor in a malnourished child with celiac disease.