Rational Design and Testing of Antibacterial Aloe Vera Hemostatic Hydrogel.

Bleeding resulting from surgical procedures or trauma, including gunshot wounds, represents a life-threatening health issue. Therefore, the development of safe, effective, and convenient hemostatic agents is critical in securing the "golden time" to save patients' lives. Plant-derived compounds and plant extracts have been regarded as promising sources of hemostatic agents in previous studies, regulating hemostatic function with low toxicity and minimal side effects within the human body. Aloe vera-based hydrogels, which are characterized by flexible strength and high functionality, have emerged as a promising platform for wound applications due to their unique biocompatibility features. This study provides a comprehensive exploration of the utilization of thickening agents and natural agents such as xanthan gum, carrageenan, Carbomer, and alginate in applying aloe vera-based hydrogels as a hemostatic. Furthermore, it also tests the use of aloe vera-based hydrogels for therapeutic delivery at wound sites through the incorporation of various antimicrobial agents to extend the utility of the hydrogels beyond hemostasis. Our novel applied research utilizes aloe vera-based hydrogel as an antimicrobial hemostatic agent, providing valuable insights for a wide range of applications and highlighting its potential to enhance hemorrhage control in various emergency scenarios.

Examining B-cell dynamics and responsiveness in different inflammatory milieus using an agent-based model.

INTRODUCTION: B-cells are essential components of the immune system that neutralize infectious agents through the generation of antigen-specific antibodies and through the phagocytic functions of naïve and memory B-cells. However, the B-cell response can become compromised by a variety of conditions that alter the overall inflammatory milieu, be that due to substantial, acute insults as seen in sepsis, or due to those that produce low-level, smoldering background inflammation such as diabetes, obesity, or advanced age. This B-cell dysfunction, mediated by the inflammatory cytokines Interleukin-6 (IL-6) and Tumor Necrosis Factor-alpha (TNF-α), increases the susceptibility of late-stage sepsis patients to nosocomial infections and increases the incidence or severity of recurrent infections, such as SARS-CoV-2, in those with chronic conditions. We propose that modeling B-cell dynamics can aid the investigation of their responses to different levels and patterns of systemic inflammation. METHODS: The B-cell Immunity Agent-based Model (BCIABM) was developed by integrating knowledge regarding naïve B-cells, short-lived plasma cells, long-lived plasma cells, memory B-cells, and regulatory B-cells, along with their various differentiation pathways and cytokines/mediators. The BCIABM was calibrated to reflect physiologic behaviors in response to: 1) mild antigen stimuli expected to result in immune sensitization through the generation of effective immune memory, and 2) severe antigen challenges representing the acute substantial inflammation seen during sepsis, previously documented in studies on B-cell behavior in septic patients. Once calibrated, the BCIABM was used to simulate the B-cell response to repeat antigen stimuli during states of low, chronic background inflammation, implemented as low background levels of IL-6 and TNF-α often seen in patients with conditions such as diabetes, obesity, or advanced age. The levels of immune responsiveness were evaluated and validated by comparing to a Veteran's Administration (VA) patient cohort with COVID-19 infection known to have a higher incidence of such comorbidities. RESULTS: The BCIABM was successfully able to reproduce the expected appropriate development of immune memory to mild antigen exposure, as well as the immunoparalysis seen in septic patients. Simulation experiments then revealed significantly decreased B-cell responsiveness as levels of background chronic inflammation increased, reproducing the different COVID-19 infection data seen in a VA population. CONCLUSION: The BCIABM proved useful in dynamically representing known mechanisms of B-cell function and reproduced immune memory responses across a range of different antigen exposures and inflammatory statuses. These results elucidate previous studies demonstrating a similar negative correlation between the B-cell response and background inflammation by positing an established and conserved mechanism that explains B-cell dysfunction across a wide range of phenotypic presentations.

Surface Roughness of Prefabricated Pediatric Zirconia Crowns Following Simulated Toothbrushing.

Purpose: The purpose of this study was to evaluate the surface roughness of three different brands of prefabricated pediatric zirconia crowns (ZRCs) following simulated toothbrushing with a variety of dentifrices. Methods: Ninety-six total maxillary right central incisor prefabricated pediatric ZRCs (n equals 32 ZRCs/brand) were obtained from the manufacturers: Kinder Krowns®, NuSmile®, and Sprig®. ZRCs were equally assigned to dentifrices (n equals eight/dentifrice) with a variety of Relative Dentin Abrasion (RDA) values: Tom's of Maine Children's; Crest Kid's; Prevident 5000; and Crest® Pro-Health. ZRCs were brushed 10,000 strokes with a V-8 Toothbrushing Machine using the assigned dentifrices. Pre- and post-intervention data for the surface roughness of ZRCs, represented in Ra (average roughness) and Rz (mean roughness depth), were obtained using a stylus profilometer. Data were analyzed independently using two-way repeated measures analysis of variance with the Holm- Sidak method (α equals 0.05). Results: Baseline versus brushed Ra Kinder Krowns® with Prevident and Sprig® with Crest Kid's indicated statistically significant differences. Sprig® versus NuSmile® utilizing Crest Kid's were different in change in roughness. Both baseline and brushed NuSmile® dentifrice options were different versus all Sprig® and Kinder® ZRCs. Conclusions: Despite statistical significance, changes in surface roughness were small in scale. Although this study did not address toothbrushing and different dentifrices may affect the mechanical properties, durability, and/or retention properties of ZRCs, the study's results provide confidence to clinicians when using prefabricated pediatric ZRCs as a sustainable treatment option along with other restorative options, such as strip crowns and stainless steel crowns.

Effect of non-contact boxing training on the frequency and timing of anticipatory postural adjustments in healthy adults.

BACKGROUND: The experiment tested the effect of non-contact boxing training on the frequency and timing of anticipatory postural adjustments (APAs) resulting from self-induced postural perturbations in healthy adults. METHODS: The 8-week non-contact boxing intervention study involved 33 healthy adults between 18 and 27 years of age who had no boxing experience (control group = 17 participants, boxing group = 16 participants). Pretests and post-tests utilized rapid bilateral arm raising as a focal movement to elicit APAs. EMG in the anterior deltoid, thoracic and lumbar erector spinae, semitendinosus, and soleus muscles was recorded. The boxing group completed twenty 90-min non-contact boxing training sessions over 8 weeks, whereas the control group kept physical activity consistent during the intervention period. RESULTS: Non-contact boxing training caused APAs to become more frequent during the focal movement, in comparison to the control group, in the soleus and in the semitendinosus after an outlier was removed. Non-contact boxing training caused earlier APA onset during the focal movement, in comparison to the control group, in the lumbar erector spinae after an outlier was removed. CONCLUSIONS: Non-contact boxing training had a modest positive effect on the frequency and timing of APAs resulting from self-induced postural perturbations in healthy adults.