Review of Urinary Tract Infections and Pyelonephritis.

Urinary tract infections (UTIs) are serious bacterial infections affecting children of all ages. An understanding of the methods of urine collection is important to prevent the contamination of urine specimens and to interpret results. The diagnosis of a UTI requires appropriate interpretation of both urinalysis and urine culture results because testing must indicate evidence of inflammation and the presence of bacteria. Rapid treatment of UTIs is imperative to prevent acute decompensation and systemic illness. Empiric antibiotics should be narrowed as soon as possible to tailor antibiotic treatment and limit antibiotic overuse. Imaging with a renal ultrasound scan is recommended for all infants with first febrile UTIs rather than a voiding cystourethrogram. An additional goal of UTI treatment is to prevent renal scarring, which can lead to lifelong health consequences. Children with anatomic abnormalities of the urinary tract and those who have recurrent UTIs are at increased risk of renal scarring. [Pediatr Ann. 2024;53(6):e217-e222.].

A Novel Presentation of Littoral Cell Angioma and Lymphatic Malformations in a Neonate.

This case report describes a novel presentation of littoral cell angioma (LCA) and lymphatic malformations involving the omentum and mesentery. To our knowledge, these 2 entities have not been reported in the same patient. A 1-month term infant male presented with chylous ascites. During his workup, imaging detected splenic nodules. Biopsies revealed that the nodules were LCA and the chylous ascites was secondary to microscopic mesenteric and omental lymphatic malformations. Evaluation for a secondary malignancy, an underlying immunologic defect, and genetic causes were unrevealing. The presence of LCA and lymphatic malformations in the same patient suggests a genetic link between these 2 rare vascular disorders and may help elucidate the etiopathogenesis of these 2 poorly understood anomalies.

Genetic evidence on the demography of speciation in allopatric dolphin species.

Under a neutral model, the stochastic lineage sorting that leads to gene monophyly proceeds slowly in large populations. Therefore, in many recent species with large population size, the genome will have mixed support for monophyly unless historical bottlenecks have accelerated coalescence. We use genealogical patterns in mitochondrial DNA and in introns of four nuclear loci to test for historical bottlenecks during the speciation and divergence of two temperate Lagenorhynchus dolphin species isolated by tropical Pacific waters (an antitropical distribution). Despite distinct morphologies, foraging behaviors, and mitochondrial DNAs, these dolphin species are polyphyletic at all four nuclear loci. The abundance of shared polymorphisms between these sister taxa is most consistent with the maintenance of large effective population sizes (5.09 x 10(4) to 10.9 x 10(4)) during 0.74-1.05 million years of divergence. A variety of population size histories are possible, however. We used gene tree coalescent probabilities to explore the rejection region for historical bottlenecks of different intensity given best estimates of effective population size under a strict isolation model of divergence. In L. obliquidens the data are incompatible with a colonization propagule of an effective size of 10 or fewer individuals. Although the ability to reject less extreme historical bottlenecks will require data from additional loci, the intermixed genealogical patterns observed between these dolphin sister species are highly probable only under an extended history of large population size. If similar demographic histories are inferred for other marine antitropical taxa, a parsimonious model for the Pleistocene origin of these distributions would not involve rare breaches of a constant dispersal barrier by small colonization propagules. Instead, a history of large population size in L. obliquidens and L. obscurus contributes to growing biological and environmental evidence that the equatorial barrier became permeable during glacial/interglacial cycles, leading to vicariant isolation of antitropical populations.