Experimental animal modelling for pressure injury: A systematic review.

INTRODUCTION: Pressure injury (PI) is a potentially serious condition that is often a consequence of other medical illnesses. It remains a challenge for the clinicians and the researcher to fully understand and develop a technique for comprehending pathogenicity, prevention and treatment. Several animal models have been created to understand the multifaceted cellular and biochemical processes of PI. There are numerous known intrinsic and extrinsic factors influencing the recovery of PI. Some of the important factors are friction, spinal cord injury, diabetes, nutrition, aging, infection, medication, obesity and vascular diseases. The dearth of optimal, pre-clinical animal models capable of mimicking the human PI remains a major challenge for its cure. An ideal animal model must endeavour the reproducibility, clinical significance, and most importantly effective translation into clinical use. METHODS: In this current systematic review, a methodological literature review was conducted on the PRISMA guidelines. PubMed/Medline, Research Scholar and Science Direct databases were searched. We conferred the animal models like mice, rats, pigs and dogs used in the PI experiments between January 1980 to January 2021. Typically, methods like Ischemia-reperfusion (IR), monoplegia pressure sore and mechanical non-invasive have been discussed. These were used to generate pressure injuries in small and large animal models. RESULTS AND CONCLUSION: Different animal models (mouse, rat, pig, dog) were evaluated based on ease of handling, availability for research, their size, skin type and the technical skills required. Studies suggest that mice and rats are the best-suited animals as their skin healing by contraction resembles the skin healing in humans. In most of the studies with mice and rats, the time taken for the recovery was between 1 and 3 weeks. Further, various techniques discussed in the current systematics review, supports the statement that the Ischemia-reperfusion (IR) method is the most suited method to study pressure injury. It is a controlled method that can develop different stages of PI and does not require any specialized setup for the application.

The safety and efficacy of BCG encapsulated alginate particle (BEAP) against M.tb H37Rv infection in Macaca mulatta : A pilot study.

Due to the limited utility of Bacillus Calmette-Guérin (BCG), the only approved vaccine available for tuberculosis, there is a need to develop a more effective and safe vaccine. We evaluated the safety and efficacy of a dry powder aerosol (DPA) formulation of BCG encapsulated alginate particle (BEAP) and the conventional intradermal BCG immunization in infant rhesus macaques (Macaca mulatta). The infant macaques were immunized intratracheally with DPA of BEAP into the lungs. Animals were monitored for their growth, behaviour, any adverse and allergic response. The protective efficacy of BEAP was estimated by the ex-vivo H37Rv infection method. Post-immunization with BEAP, granulocytes count, weight gain, chest radiography, levels of liver secreted enzymes, cytokines associated with inflammation like TNF and IL-6 established that BEAP is non-toxic and it does not elicit an allergic response. The T cells isolated from BEAP immunized animals' blood, upon stimulation with M.tb antigen, secreted high levels of IFN-γ, TNF, IL-6 and IL-2. The activated T cells from BEAP group, when co-cultured with M.tb infected macrophages, eliminated largest number of infected macrophages compared to the BCG and control group. This study suggests the safety and efficacy of BEAP in Non-human primate model.

Submental nalbuphine exhibits improved efficacy in ameliorating acute pain in prehospital emergent conditions; a comparative study with conventional intramuscular using gamma scintigraphy.

BACKGROUND: Nalbuphine (NLB) is a kappa-agonist and mu-partial antagonist, widely used for opioid withdrawal de-addiction, opioid-induced pruritis and as emergent analgesia. OBJECTIVE: The present study aimed to assess the safety and efficacy of NLB in pain sensitization, through a submental route so as to provide faster management in emergent situations. MATERIALS & METHODS: In-vivo efficacy and safety studies of NLB-submental injection were assessed in Sprague-Dawley(SD) rats. For eddy's hot plate study, animals were allocated into three groups, the first group served as normal control; group II received NLB (through submental route at 1.2 mg/kg); group III received NLB (through intramuscular route at 1.2 mg/kg). Response latency (in terms of response latency) was measured at 10, 30 & 60 min in all the experimental groups. Safety studies were carried out according to OECD 423. In-vitro release study was conducted using a cellulose dialysis membrane (12,000 KDa). The biodistribution and release kinetics studies were carried out using gamma scintigraphy studies in New Zealand rabbits and humans respectively. RESULTS: The response latency of NLB from the submental route was found to be 7.17 (SD 1.47) seconds and in the case of the intramuscular route it was calculated as 4.00 (SD 1.26) seconds at 10 min. The data depicts the better efficacy of submental injection in ameliorating pain than the intramuscular injection. Toxicity studies predict the safe profile through a submental route. The release kinetics in humans of submental NLB was 46% faster as compared to the intramuscular site of injection. The NLB injection through both routes was compared by non-invasive gamma scintigraphy technique and we found that submental injection has faster (within 10 min) onset of action & distributes rapidly. CONCLUSION: The submental route of NLB is faster, more efficacious than the intramuscular route. Thus, we conclude that in the case of emergent scenarios (i.v or i.m. route is compromised), where immediate relief is necessary, the submental route is a preferred choice.

Aerosol immunization by alginate coated mycobacterium (BCG/MIP) particles provide enhanced immune response and protective efficacy than aerosol of plain mycobacterium against M.tb. H37Rv infection in mice.

BACKGROUND: With the aim of preparing a more effective, safe and economical vaccine for tuberculosis, inhalable live mycobacterium formulations were evaluated. METHODS: Alginate particles in the size range of 2-4 µm were prepared by encapsulating live Bacille Calmette-Guérin (BCG) and "Mycobacterium indicus pranii" (MIP). These particles were characterized for their size, stability and release profile. Mice were immunized with liquid aerosol or dry powder aerosol (DPA) alginate encapsulated mycobacterium particles and their in-vitro recall response and infection with mycobacterium H37Rv were investigated. RESULTS: It was found that the DPA of alginate encapsulated mycobacterium particles invoked superior immune response and provided higher protection in mice than the liquid aerosol. The BCG encapsulated in alginate particles (BEAP) and MIP encapsulated in alginate particles (MEAP) were engulfed by bone marrow dendritic cells (BMDCs) and co-localized with lysosome. The MEAP/BEAP activated BMDCs exhibited higher chemotaxis movement and had enhanced ability of antigen presentation to T cells. The in-vitro recall response of BEAP/MEAP immunized mice when compared in terms of proliferation index and Interferon gamma (IFN-gamma) released by splenocytes and mediastinal lymph node cells was found to be higher than mice immunized by liquid aerosol of BCG/MIP. Finally, different groups of immunized mice were infected with M. tb H37Rv and after 16 weeks the Colony forming units (CFUs) in lung and spleen estimated. The bacilli burden in the BEAP/MEAP immunized mice was significantly less than the respective liquid aerosol immunized mice and the histopathology of BEAP/MEAP immunized mice lungs showed very little damage. CONCLUSIONS: These inhale-able vaccines formulation of alginate coated live mycobacterium are more immunogenic as compared to the aerosol of bacilli and they provide better protection in mice when infected with H37Rv.

An inexpensive and easy-to-make customized antibiotics mix for mycobacterium culture.

The cultivation of mycobacteria often requires the use of several antibiotics to limit the growth of other rapidly growing micro-flora present in the growth medium. This antibiotic cocktail is one of the most expensive reagents required for mycobacterium culture. Here we present a customized antibiotics mix that is easy to prepare at a fraction of the cost of the commercially available antibiotic mixture that protects against transient flora, which are normally present in lungs, without affecting mycobacterial colony number.

Autologous NeoHep Derived from Chronic Hepatitis B Virus Patients' Blood Monocytes by Upregulation of c-MET Signaling.

In view of the escalating need for autologous cell-based therapy for treatment of liver diseases, a novel candidate has been explored in the present study. The monocytes isolated from hepatitis B surface antigen (HBsAg) nucleic acid test (NAT)-positive (HNP) blood were differentiated to hepatocyte-like cells (NeoHep) in vitro by a two-step culture procedure. The excess neutrophils present in HNP blood were removed before setting up the culture. In the first step of culture, apoptotic cells were depleted and genes involved in hypoxia were induced, which was followed by the upregulation of genes involved in the c-MET signaling pathway in the second step. The NeoHep were void of hepatitis B virus and showed expression of albumin, connexin 32, hepatocyte nuclear factor 4-α, and functions such as albumin secretion and cytochrome P450 enzyme-mediated detoxification of xenobiotics. The engraftment of NeoHep derived from HBsAg-NAT-positive blood monocytes in partially hepatectomized NOD.CB17-Prkdcscid /J mice liver and the subsequent secretion of human albumin and clotting factor VII activity in serum make NeoHep a promising candidate for cell-based therapy. Stem Cells Translational Medicine 2017;6:174-186.