A Simulation of the Effects of Diffusion on Hyperpolarized [1-13C]-Pyruvate Signal Evolution.

OBJECTIVE: Hyperpolarized [1-13C]-pyruvate magnetic resonance imaging is an emerging metabolic imaging method that offers unprecedented spatiotemporal resolution for monitoring tumor metabolism in vivo. To establish robust imaging biomarkers of metabolism, we must characterize phenomena that may modulate the apparent pyruvate-to-lactate conversion rate (kPL). Here, we investigate the potential effect of diffusion on pyruvate-to-lactate conversion, as failure to account for diffusion in pharmacokinetic analysis may obscure true intracellular chemical conversion rates. METHODS: Changes in hyperpolarized pyruvate and lactate signal were calculated using a finite-difference time domain simulation of a two-dimensional tissue model. Signal evolution curves with intracellular kPL values from 0.02 to 1.00 s-1 were analyzed using spatially invariant one-compartment and two-compartment pharmacokinetic models. A second spatially variant simulation incorporating compartmental instantaneous mixing was fit with the same one-compartment model. RESULTS: When fitting with the one-compartment model, apparent kPL underestimated intracellular kPL by approximately 50% at an intracellular kPL of 0.02 s-1. This underestimation increased for larger kPL values. However, fitting the instantaneous mixing curves showed that diffusion accounted for only a small part of this underestimation. Fitting with the two-compartment model yielded more accurate intracellular kPL values. SIGNIFICANCE: This work suggests diffusion is not a significant rate-limiting factor in pyruvate-to-lactate conversion given that our model assumptions hold true. In higher order models, diffusion effects may be accounted for by a term characterizing metabolite transport. Pharmacokinetic models used to analyze hyperpolarized pyruvate signal evolution should focus on carefully selecting the analytical model for fitting rather than accounting for diffusion effects.

Childhood Early T Cell Precursor Acute Lymphoblastic Leukaemia with t(12;17) (p13;q21) Translocation - A Rare Entity or Part of ETP/Myeloid Mixed Phenotype Acute Leukaemia.

The translocation t (12;17) (p13; q21) is a rare cytogenetic event most commonly described in pre-B- acute lymphoblastic leukaemia and acute myeloid leukaemia. We identified a child with an immunophenotype of Early T Cell Precursor Acute Lymphoblastic Leukaemia ETP- ALL having t (12;17) (p13; q21) translocation as the primary karyotypic anomaly. The association of t (12;17) (p13; q21) with ETP-ALL has not been described previously in literature. The possibility of it being a novel genetic abnormality or a part of the newly described entity of ETP/myeloid MPAL is being discussed. Detection of such abnormalities can alter the prognosis of ETP-ALL. Key words: ETP-ALL , t(12;17) (p13;q21) translocation, ETP- MPAL.

Associations of Demographic, Socioeconomic, and Cognitive Characteristics With Mobile Health Access: MESA (Multi-Ethnic Study of Atherosclerosis).

Background Mobile health (mHealth) has an emerging role in the prevention of cardiovascular disease. This study evaluated possible inequities in mHealth access in older adults. Methods and Results mHealth access was assessed from 2019 to 2020 in MESA (Multi-Ethnic Study of Atherosclerosis) telephone surveys of 2796 participants aged 62 to 102 years. A multivariable logistic regression model adjusted for general health status assessed associations of mHealth access measures with relevant demographic, socioeconomic, and cognitive characteristics. There were lower odds of all access measures with older age (odds ratios [ORs], 0.37-0.59 per 10 years) and annual income <$50 000 (versus ≥$50 000 ORs, 0.55-0.62), and higher odds with higher Cognitive Abilities Screening Instrument Score (ORs, 1.22-1.29 per 5 points). Men (versus women) had higher odds of internet access (OR, 1.32 [95% CI,1.05-1.66]) and computing device ownership (OR, 1.31 [95% CI, 1.05-1.63]) but lower fitness tracker ownership odds (OR, 0.70 [95% CI, 0.49-0.89]). For internet access and computing device ownership, we saw lower odds for Hispanic participants (versus White participants OR, 0.61 [95% CI, 0.44-0.85]; OR, 0.69 [95% CI, 0.50-0.95]) and less than a high school education (versus bachelor's degree or higher OR, 0.27 [95% CI, 0.18-0.40]; OR, 0.32 [95% CI, 0.28-0.62]). For internet access, lower odds were seen for Black participants (versus White participants OR, 0.64 [95% CI, 0.47-0.86]) and other health insurance (versus health maintenance organization/private OR, 0.59 [95% CI, 0.47-0.74]). Chinese participants (versus White participants) had lower internet access odds (OR, 0.63 [95% CI, 0.44-0.91]) but higher computing device ownership odds (OR, 1.87 [95% CI, 1.28-2.77]). Conclusions Among older-age adults, mHealth access varied by major demographic, socioeconomic, and cognitive characteristics, suggesting a digital divide. Novel mHealth interventions should consider individual access barriers. Registration URL: https://www.clinicaltrials.gov/; Unique identifier: NCT00005487.

Childhood Oral Lichen Planus: Report of Two Cases.

Lichen planus (LP) is a chronic mucocutaneous disease widely recognized in adults, but uncommon in children. The purpose of this paper is to report two cases of LP in children. The diagnosis was made based on clinical and histopathological findings. The treatment consisted of antifungal and multivitamin therapy. Regression of lesions was observed. The patients are still under follow-up. Although LP is uncommon in children, it is necessary to have adequate knowledge about this condition for proper diagnosis and treatment.

Delayed reimplantation: a case report.

A 12-year-old boy reported to the clinic with a history of trauma, whereas playing 1 day before. On examination it was noted that the patient had an avulsed tooth in relation to 11, Class III fracture in relation to 12 and Class II fracture in relation to 21. The avulsed tooth was brought by the patient wrapped in a newspaper. Although the tooth was in highly unfavorable storage condition, it was decided to reimplant the teeth since the patient was young and to relieve him from psychological, cosmetic and functional trauma. Now after 24 months, the tooth is, functional, firm and free of symptoms with minimal signs of resorption. Even though the long-term prognosis is uncertain, this treatment technique has proven to be an advantage for the patient in this growing period by maintaining the esthetics, by maintaining the height of alveolar bone and making the provision of an aesthetically acceptable permanent restoration at a later age if prognosis becomes poor.