Neuropsychological Correlates of Adherence in Youth with Behaviorally Acquired HIV.

Youth living with behaviorally acquired HIV (YLWH) are at-risk for both neuropsychological disorders and antiretroviral therapy (ART) non-adherence; little is known about their interrelationship over time in YLWH. Neuropsychological and psychiatric functioning, substance use, and self-report of 7-day/week and weekend ART adherence were assessed at baseline and Weeks 24, 48, 96 and 144 of a longitudinal study evaluating the impact of early (CD4>350) versus standard of care (CD4≤350) treatment initiation on neuropsychological functioning in 111 treatment-naïve YLWH age 18-24 years at entry. Bayesian multi-level models for adherence (≥ 90% vs. <90%) were fit using random intercepts for repeated measures. Adjusted odds ratios (OR [95% credible interval]) for higher versus lower baseline Motor function for visit adherence were 0.58 (0.25, 1.16), 0.5 (0.15, 1.38), 0.52 (0.16, 1.52), and 0.94 (0.3, 2.8) at Weeks 24, 48, 96, and 144, respectively. Week 24 adherence was associated with higher adjusted odds of Motor function at Week 48 (week: 0.27, -0.05-0.59; weekend: 0.28, -0.07-0.62). Week 96 Complex Executive functioning was associated with higher adjusted odds of adherence at Week 144, OR = 4.26 (1.50, 14.33). Higher Motor functioning emerged most consistently associated with lower odds of adherence in YLWH. Complex Executive functioning was associated with adherence only at end of study, suggesting potential contribution in adherence over the long-term.

The Relationship Between Neonatal Surgery, Postpartum Depression, and Infant Clinical Course.

OBJECTIVE: Postpartum depression (PPD) affects 10-15% of mothers in the general population, and studies show increased incidence for mothers of infants with serious health conditions. This study investigates incidence of PPD in mothers of surgical patients in the neonatal intensive care unit (NICU) and characterizes these patients' clinical and neurodevelopmental outcomes. METHODS: This retrospective cohort study analyzed Nebraska's Tracking Infant Progress Statewide (TIPS) database and referring hospital medical records from February 2013 to June 2018. Upon NICU discharge, children were referred to the TIPS program, with scheduled follow-up appointments at approximately 6 months corrected age. All patients seen in NICU follow-up clinic with recorded scores for maternal Edinburgh postnatal depression screen (EPDS) were eligible except infants with congenital heart disease as this cohort was previously studied. Patients were stratified into groups based on presence or absence of a general surgical procedure within the first 6 months of life and positive (≥ 10) or negative (< 10) EPDS score. Statistical analyses assessed for significant differences between groups regarding gestational age, birth weight, maternal age, length of NICU stay (LOS), number of days on a ventilator, payment method, ethnicity, developmental testing, and rate of referral for early intervention services. RESULTS: Of 436 patients, 83 were surgical patients (16 with positive EPDS; 19.3% incidence), and 353 were non-surgical patients (44 with positive EPDS; 12.5% incidence). Statistical analysis showed no significant relationship between neonatal surgery and positive EPDS (χ2 = 2.6, p = 0.1). While the surgical cohort had longer LOS and days on ventilator, maternal EPDS did not predict these factors. In the surgical cohort, mothers of children not independent on oral feeding at discharge were more likely to screen positive for depression (7/14, 50% vs. 7/61, 11%; p < 0.05). CONCLUSION: Mothers of surgical patients are not significantly more likely to screen positive for post-partum depression compared to other NICU mothers. This underscores the importance of routine screening for PPD in mothers of both surgical and non-surgical NICU patients in order to identify parents and children at risk.

Minimum dose rate estimation for pulsed FLASH radiotherapy: A dimensional analysis.

PURPOSE/OBJECTIVES: To provide an order of magnitude estimate of the minimum dose rate ( R min ) required by pulsed ultra-high dose rate radiotherapy (FLASH RT) using dimensional analysis. MATERIALS/METHODS: In this study, we postulate that radiation-induced transient hypoxia inside normal tissue cells during FLASH RT results in better normal tissue sparing over conventional dose rate radiotherapy. We divide the process of cell irradiation by an ultra-short radiation pulse into three sequential phases: (a) The radiation pulse interacts with the normal tissue cells and produces radiation-induced species. (b) The radiation-induced species react with oxygen molecules and reduce the cell environmental oxygen concentration ( O 2 ). (c) Oxygen molecules, from nearest capillaries, diffuse slowly back into the resulted low O 2 regions. By balancing the radiation-induced oxygen depletion in phase II and diffusion-resulted O 2 replenishment in phase III, we can estimate the maximum allowed pulse repetition interval to produce a pulse-to-pulse superimposed O 2 reduction against the baseline O 2 . If we impose a threshold in radiosensitivity reduction to achieve clinically observable radiotherapy oxygen effect and combine the processes mentioned above, we could estimate the R min required for pulsed FLASH RT through dimensional analysis. RESULTS: The estimated R min required for pulsed FLASH RT is proportional to the product of the oxygen diffusion coefficient and O 2 inside the cell, and inversely proportional to the product of the square of the oxygen diffusion distance and the drop of intracellular O 2 per unit radiation dose. Under typical conditions, our estimation matches the order of magnitude with the dose rates observed in the recent FLASH RT experiments. CONCLUSIONS: The R min introduced in this paper can be useful when designing a FLASH RT system. Additionally, our analysis of the chemical and physical processes may provide some insights into the FLASH RT mechanism.

Associations of the infancy body mass index peak with anthropometry and cardiometabolic risk in Mexican adolescents.

BACKGROUND: Early-life growth dynamics are associated with future health. Little is known regarding timing and magnitude of the infancy body mass index (BMI) peak with adiposity and metabolic biomarkers during adolescence. AIM: To examine associations of the infancy BMI peak with anthropometry and cardiometabolic risk during peripuberty. METHODS: Among 163 ELEMENT participants, this study estimated age and magnitude of the infancy BMI peak from eight anthropometric measurements from birth-36 months using Newton's Growth Models, an acceleration-based process model. Associations were examined of the infancy milestones with anthropometry and cardiometabolic risk at 8-14 years using linear regression models that accounted for maternal calcium supplementation and age; child's birthweight, sex, and age; and the other infancy milestone. RESULTS: Median age at the infancy BMI peak was 9.6 months, and median peak BMI was 16.5 kg/m2. Later age and larger magnitude of the peak predicted higher BMI z-score, waist circumference, and skinfold thicknesses; i.e. each 1 month of age at peak and each 1 kg/m2 of peak BMI corresponded with 0.04 (0.01-0.07) and 0.33 (0.17-0.48) units of higher BMI z-score, respectively. Later age at peak was also a determinant of worse glycaemia and higher blood pressure. CONCLUSION: Later age and larger magnitude of the infancy BMI peak are associated with higher adiposity at 8-14 years of age. Later age but not magnitude of the BMI peak are related to a worse cardiometabolic profile during peripuberty.

A comprehensive dosimetric study on switching from a Type-B to a Type-C dose algorithm for modern lung SBRT.

BACKGROUND: Type-C dose algorithms provide more accurate dosimetry for lung SBRT treatment planning. However, because current dosimetric protocols were developed based on conventional algorithms, its applicability for the new generation algorithms needs to be determined. Previous studies on this issue used small sample sizes and reached discordant conclusions. Our study assessed dose calculation of a Type-C algorithm with current dosimetric protocols in a large patient cohort, in order to demonstrate the dosimetric impacts and necessary treatment planning steps of switching from a Type-B to a Type-C dose algorithm for lung SBRT planning. METHODS: Fifty-two lung SBRT patients were included, each planned using coplanar VMAT arcs, normalized to D95% = prescription dose using a Type-B algorithm. These were compared against three Type-C plans: re-calculated plans (identical plan parameters), re-normalized plans (D95% = prescription dose), and re-optimized plans. Dosimetric endpoints were extracted and compared among the four plans, including RTOG dosimetric criteria: (R100%, R50%, D2cm, V105%, and lung V20), PTV Dmin, Dmax, Dmean, V% and D90%, PTV coverage (V100%), homogeneity index (HI), and Paddick conformity index (PCI). RESULTS: Re-calculated Type-C plans resulted in decreased PTV Dmin with a mean difference of 5.2% and increased Dmax with a mean difference of 3.1%, similar or improved RTOG dose compliance, but compromised PTV coverage (mean D95% and V100% reduction of 2.5 and 8.1%, respectively). Seven plans had >5% D95% reduction (maximum reduction = 16.7%), and 18 plans had >5% V100% reduction (maximum reduction = 60.0%). Re-normalized Type-C plans restored target coverage, but yielded degraded plan conformity (average PCI reduction 4.0%), and RTOG dosimetric criteria deviation worsened in 11 plans, in R50%, D2cm, and R100%. Except for one case, re-optimized Type-C plans restored RTOG compliance achieved by the original Type-B plans, resulting in similar dosimetric values but slightly higher target dose heterogeneity (mean HI increase = 13.2%). CONCLUSIONS: Type-B SBRT lung plans considerably overestimate target coverage for some patients, necessitating Type-C re-normalization or re-optimization. Current RTOG dosimetric criteria appear to remain appropriate.

Still equivalent for dose calculation in the Monte Carlo era? A comparison of free breathing and average intensity projection CT datasets for lung SBRT using three generations of dose calculation algorithms.

PURPOSE: Inhomogeneity dose modeling and respiratory motion description are two critical technical challenges for lung stereotactic body radiotherapy, an important treatment modality for small size primary and secondary lung tumors. Recent studies revealed lung density-dependent target dose differences between Monte Carlo (Type-C) algorithm and earlier algorithms. Therefore, this study aimed to investigate the equivalence of the two most popular CT datasets for treatment planning, free breathing (FB) and average intensity projection (AIP) CTs, using Type-C algorithms, and comparing with two older generation algorithms (Type-A and Type-B). METHODS: Twenty patients (twenty-one lesions) were planned using a Type-A algorithm on the FB CT. Lung was contoured separately on FB and AIP CTs and compared. Dose comparison was obtained between the two CTs using four commercial dose algorithms including one Type-A (Pencil Beam Convolution - PBC), one Type-B (Analytical Anisotropic Algorithm - AAA), and two Type-C algorithms (Voxel Monte Carlo - VMC and Acuros External Beam - AXB). For each algorithm, the dosimetric parameters of the target (PTV, Dmin , Dmax , Dmean , D95, and D90) and lung (V5, V10, V20, V30, V35, and V40) were compared between the two CTs using the Wilcoxon signed rank test. Correlation between dosimetric differences and density differences for each algorithm were studied using linear regression and Spearman correlation, in which both global and local density differences were evaluated. RESULTS: Although the lung density differences on FB and AIP CTs were statistically significant (P = 0.003), the magnitude was small at 1.21 ± 1.45%. Correspondingly, for the two Type-C algorithms, target and lung dosimetric differences were small in magnitude and statistically insignificant (P > 0.05) for all but one instance, similar to the findings for the older generation algorithms. Nevertheless, a significant correlation was shown between the dosimetric and density differences for Type-C and Type-B algorithms, but not for the Type-A algorithm. CONCLUSIONS: With the capability to more accurately model inhomogeneity, Monte Carlo (Type-C) algorithms are sensitive to respiration-induced local and global tissue density changes and exhibit a strong correlation between dosimetric and density differences. However, FB and AIP CTs may still be considered equivalent for dose calculation in the Monte Carlo era, due to the small magnitude of lung density differences between these two datasets.

Impacts of beach wrack removal via grooming on surf zone water quality.

Fecal indicator bacteria (FIB) are used to assess the microbial water quality of recreational waters. Increasingly, nonfecal sources of FIB have been implicated as causes of poor microbial water quality in the coastal environment. These sources are challenging to quantify and difficult to remediate. The present study investigates one nonfecal FIB source, beach wrack (decaying aquatic plants), and its impacts on water quality along the Central California coast. The prevalence of FIB on wrack was studied using a multibeach survey, collecting wrack throughout Central California. The impacts of beach grooming, to remove wrack, were investigated at Cowell Beach in Santa Cruz, California using a long-term survey (two summers, one with and one without grooming) and a 48 h survey during the first ever intensive grooming event. FIB were prevalent on wrack but highly variable spatially and temporally along the nine beaches sampled in Central California. Beach grooming was generally associated with either no change or a slight increase in coastal FIB concentrations and increases in surf zone turbidity and silicate, phosphate, and dissolved inorganic nitrogen concentrations. The findings suggest that beach grooming for wrack removal is not justified as a microbial pollution remediation strategy.