Association between Severe Early Childhood Caries, Dietary Preferences, and 2nd Digit-4th Digit (2D:4D) Ratio.

Background and aim: To evaluate the association between severe early childhood caries (S-ECC), dietary preferences, and 2nd digit-4th digit (2D:4D) ratio. The objective is to contrast the detection and prevalence of dental caries in children with different sensitivity levels to the bitter taste of 6-n-propylthiouracil (PROP) and its association with 2D:4D. Materials and methods: A total of 300 children below 71 months of age were assigned to two study groups-group I (caries-free) and group II (caries). PROP sensitivity test was carried out to determine the inherent genetic ability to taste a bitter or sweet substance. Evaluation of dietary preferences was carried out using a food preference questionnaire, which was completed by the parents of the children to know the child's dietary habits and their sweet, sour, and strong taste preferences. The length of the index (2D) and ring (4D) finger was measured with the help of digital vernier caliper to record the 2D:4D ratio. The data obtained was subjected to statistical analysis using Pearson's Chi-squared test and one-way analysis of variance (ANOVA). Results: The results suggested a positive association between S-ECC and dietary preferences but could not establish a straightforward 1:1 relation between 2D:4D ratio and S-ECC. Conclusion: An individual considered as nontaster by PROP test was a sweet liker with low 2D:4D ratio having high caries index. The association between 2D:4D ratio and S-ECC should further be explored by taking other influencing factors into consideration before arriving at a definitive conclusion. How to cite this article: Srivastava SK, Garg N, Pathivada L, et al. Association between Severe Early Childhood Caries, Dietary Preferences, and 2nd Digit-4th Digit (2D:4D) Ratio. Int J Clin Pediatr Dent 2023;16(5):740-744.

Examining the role of nickel and NiTi nanoparticles promoting inflammation and angiogenesis.

Nickel titanium (NiTi, or Nitinol) alloy is used in several biomedical applications, including cardiac, peripheral vascular, and fallopian tube stents. There are significant biocompatibility issues of metallic implants to nickel ions and nano-/micro-sized alloy particles. Our laboratories have recently shown that microscale CoCr wear particles from metal-on-metal hips crosslink with the innate immune signaling Toll-like receptor 4 (TLR4), prompting downstream signaling that results in interleukin (IL)-1ß and IL-8 gene expression. In vivo, NiTi alloy can also generate wear particles on the nanoscale (NP) that have thus far not been studied for their potential to induce inflammation and angiogenesis that can, in turn, contribute to implant (e.g. stent) failure. Earlier studies by others demonstrated that nickel could induce contact hypersensitivity by crosslinking the human, but not the mouse, TLR4. In the present work, it is demonstrated that NiCl2 ions and NiTi nanoparticles induce pro-inflammatory and pro-angiogenic cytokine/chemokine expression in human endothelial and monocyte cell lines in vitro. These observations prompt concerns about potential mechanisms for stent failure. The data here showed a direct correlation between intracellular uptake of Ni2+ and generation of reactive oxygen species. To determine a role for nickel and NiTi nanoparticles in inducing angiogenesis in vivo, 1-cm silicone angioreactors were implanted subcutaneously into athymic (T-cell-deficient) nude mice. The angioreactors contained Matrigel (a gelatinous protein mixture that resembles extracellular matrix) in addition to one of the following: PBS (negative control), VEGF/FGF-2 (positive control), NiCl2, or NiTi NP. The implantation of angioreactors represents a potential tool for quantification of angiogenic potentials of medical device-derived particles and ions in vivo. By this approach, NiTi NP were found to be markedly angiogenic, while Ni2+ was less-so. The angioreactors may provide a powerful tool to examine if debris shed from medical devices may promote untoward biological effects.

Novel nanocarrier for oral Hepatitis B vaccine.

Oral vaccination is a safe, cost effective and non-invasive method suitable for mass immunization. We fabricated nanoparticle (NP) with 14kd polycaprolactone (PCL) entrapping hepatitis B surface antigen (HBsAg) stabilized with Pluronics® F127 and used it as oral delivery vehicle. We evaluated its efficacy for specific antibody production and compared with parenteral routes of immunization in mice. We found a superior antibody response with a higher titer of anti-HBsAg antibody till 2 months following single oral administration compared to other routes of immunization and conventional alum-based HBsAg vaccine. The NPs with the antigen were found in the macrophages in small intestinal villi, peripheral lymph nodes and other reticulo-endothelial organs 2 months after oral administration. This study suggests the efficacy of the current nanocarrier system for efficient antigen presentation disseminated in peripheral lymphoid tissues following oral administration with a prolonged antibody response, which can minimize the requirement of booster dose.