Effects of color variation and physiological state on ascidian microbiomes.

Ascidians, known for their color variation, host species-specific microbial symbiont communities. Some ascidians can also transition into a nonfiltering (resting) physiological state. Recent studies suggest that the microbial symbiont communities may vary across different physiological states and color morphs of the host. The colonial ascidian, Polyclinum constellatum, which exhibits several color morphs in the Caribbean Sea, periodically ceases its filtering activity. To investigate if color variation in P. constellatum is indicative of sibling speciation, we sequenced fragments of the ribosomal 18S rRNA and the mitochondrial cytochrome oxidase subunit I genes. Additionally, we sequenced a fragment of the 16S rRNA gene to characterize the microbial communities of two common color morphs (red and green) in colonies that were either actively filtering (active) or nonfiltering (resting). Phylogenetic analyses of both ascidian genes resulted in well-supported monophyletic clades encompassing all color variants of P. constellatum. Interestingly, no significant differences were observed among the microbial communities of the green and red morphs, suggesting that color variation in this species is a result of intraspecific variation. However, the host's physiological state significantly influenced the microbial community structure. Nonfiltering (resting) colonies hosted higher relative abundances of Kiloniella (Alphaproteobacteria) and Fangia (Gammaproteobacteria), while filtering colonies hosted more Reugeria (Alphaproteobacteria) and Endozoicomonas (Gammaproteobacteria). This study demonstrates that microbial symbiont communities serve as reliable indicators of the taxonomic state of their host and are strongly influenced by the host's feeding condition.

Diagnostic Performance of Renal Contrast Excretion on Early Phase CT Myelography in Spontaneous Intracranial Hypotension.

BACKGROUND AND PURPOSE: Early opacification of the renal collecting system during CT myelography (CTM) performed for the evaluation of Spontaneous Intracranial Hypotension (SIH) has been demonstrated in prior studies. However, these investigations often included CTMs scanned >30 minutes after intrathecal contrast injection, a longer delay than the myelographic techniques used in current practice. The purpose of this study was to determine whether renal contrast excretion (RCE) measured during this earlier time period (≤30 minutes) can discriminate patients with SIH from patients without SIH. MATERIALS AND METHODS: Single-center, retrospective cohort of consecutive patients presenting for evaluation of possible SIH between July 2021-May 2022. RCE was measured in both renal hila using standardized (5-15mm3) ROIs. ROC curves were constructed comparing RCE between patients with SIH to patients without SIH in the overall cohort, and within the subgroup of patients with negative myelograms. RESULTS: The study cohort included 190 subjects. Both unadjusted and adjusted models demonstrated a statistically significant increase in renal contrast density among patients with SIH compared to those without SIH (p-values ≤ 0.001). The ROC curve showed moderate discrimination between these groups (AUC 0.76). However, using clinically meaningful test criteria of sensitivity >90% or specificity >90%, the two corresponding threshold HU values resulted in low specificity of 31.3% and sensitivity of 50.8%. Subgroup analysis of patients with negative myelograms showed poorer performance in discriminating SIH+ from SIH- (AUC 0.62). In this subgroup, using similar test criteria of sensitivity >90% or specificity >90 resulted in low specificities and sensitivities, at 26.0% and 37.5% respectively. CONCLUSIONS: We found a statistically significant positive association between RCE and SIH diagnosis during early-phase CTM, however clinically useful thresholds based on cutoff values for renal HU resulted in poor sensitivities or specificities, with substantial false positives or false negatives, respectively. Thus, while we confirmed statistically significant differences in RCE in the ≤30 min time period, in keeping with prior investigations of more delayed time periods, overlap in renal attenuation values prevented the development of clinically useful threshold value for discriminating SIH+ from SIH-patients. ABBREVIATIONS: SIH = spontaneous intracranial hypotension; RCE = renal contrast excretion; CTM = CT myelography; CVF = CSF-venous fistula; ICHD-3 = international classification of headache disorders third edition; CKD = chronic kidney disease.

Subventricular zone stem cell niche injury is associated with intestinal perforation in preterm infants and predicts future motor impairment.

Brain injury is highly associated with preterm birth. Complications of prematurity, including spontaneous or necrotizing enterocolitis (NEC)-associated intestinal perforations, are linked to lifelong neurologic impairment, yet the mechanisms are poorly understood. Early diagnosis of preterm brain injuries remains a significant challenge. Here, we identified subventricular zone echogenicity (SVE) on cranial ultrasound in preterm infants following intestinal perforations. The development of SVE was significantly associated with motor impairment at 2 years. SVE was replicated in a neonatal mouse model of intestinal perforation. Examination of the murine echogenic subventricular zone (SVZ) revealed NLRP3-inflammasome assembly in multiciliated FoxJ1+ ependymal cells and a loss of the ependymal border in this postnatal stem cell niche. These data suggest a mechanism of preterm brain injury localized to the SVZ that has not been adequately considered. Ultrasound detection of SVE may serve as an early biomarker for neurodevelopmental impairment after inflammatory disease in preterm infants.