Spatiotemporal assessment of pathogenic Leptospira in subtropical coastal watersheds.

The World Health Organization classifies leptospirosis as a significant public health concern, predominantly affecting impoverished and unsanitary regions. By using the Pensacola Bay System as a case study, this study examines the underappreciated susceptibility of developed subtropical coastal ecosystems such as the Pensacola Bay System to neglected zoonotic pathogens such as Leptospira. We analyzed 132 water samples collected over 12 months from 44 distinct locations with high levels of Escherichia coli (>410 most probable number/100 mL). Fecal indicator bacteria (FIB) concentrations were assessed using IDEXX Colilert-18 and Enterolert-18, and an analysis of water physiochemical characteristics and rainfall intensity was conducted. The LipL32 gene was used as a quantitative polymerase chain reaction (qPCR) indicator to identify the distribution of Leptospira interrogans. The results revealed 12 instances of the presence of L. interrogans at sites with high FIB over various land cover and aquatic ecosystem types. Independent of specific rainfall events, a seasonal relationship between precipitation and elevated rates of fecal bacteria and leptospirosis was found. These findings highlight qPCR's utility in identifying pathogens in aquatic environments and the widespread conditions where it can be found in natural and developed areas.

Frog hatchlings use early environmental cues to produce an anticipatory resource-use phenotype.

Developmental plasticity can occur at any life stage, but plasticity that acts early in development may give individuals a competitive edge later in life. Here, we asked if early (pre-feeding) exposure to a nutrient-rich resource impacts hatchling morphology in Mexican spadefoot toad tadpoles, Spea multiplicata. A distinctive carnivore morph can be induced when tadpoles eat live fairy shrimp. We investigated whether cues from shrimp--detected before individuals are capable of feeding--alter hatchling morphology such that individuals could potentially take advantage of this nutritious resource once they begin feeding. We found that hatchlings with early developmental exposure to shrimp were larger and had larger jaw muscles--traits that, at later stages, increase a tadpole's competitive ability for shrimp. These results suggest that early developmental stages can assess and respond to environmental cues by producing resource-use phenotypes appropriate for future conditions. Such anticipatory plasticity may be an important but understudied form of developmental plasticity.

Evolutionary rescue via transgenerational plasticity: Evidence and implications for conservation.

When a population experiences severe stress from a changing environment, evolution by natural selection can prevent its extinction, a process dubbed "evolutionary rescue." However, evolution may be unable to track the sort of rapid environmental change being experienced by many modern-day populations. A potential solution is for organisms to respond to environmental change through phenotypic plasticity, which can buffer populations against change and thereby buy time for evolutionary rescue. In this review, we examine whether this process extends to situations in which the environmentally induced response is passed to offspring. As we describe, theoretical and empirical studies suggest that such "transgenerational plasticity" can increase population persistence. We discuss the implications of this process for conservation biology, outline potential limitations, and describe some applications. Generally, transgenerational plasticity may be effective at buying time for evolutionary rescue to occur.

Transcriptomic bases of a polyphenism.

Polyphenism-in which multiple distinct phenotypes are produced from a single genotype owing to differing environmental conditions-is commonplace, but its molecular bases are poorly understood. Here, we examine the transcriptomic bases of a polyphenism in Mexican spadefoot toads (Spea multiplicata). Depending on their environment, their tadpoles develop into either a default "omnivore" morph or a novel "carnivore" morph. We compared patterns of gene expression among sibships that exhibited high versus low production of carnivores when reared in conditions that induce the carnivore morph versus those that do not. We found that production of the novel carnivore morph actually involved changes in fewer genes than did the maintenance of the default omnivore morph in the inducing environment. However, only body samples showed this pattern; head samples showed the opposite pattern. We also found that changes to lipid metabolism (especially cholesterol biosynthesis) and peroxisome contents and function might be crucial for establishing and maintaining differences between the morphs. Thus, our findings suggest that carnivore phenotype might have originally evolved following the breakdown of robustness mechanisms that maintain the default omnivore phenotype, and that the carnivore morph is developmentally regulated by lipid metabolism and peroxisomal form, function, and/or signaling. This study also serves as a springboard for further exploration into the nature and causes of plasticity in an emerging model system.

Novel Regional Anesthesia for Outpatient Surgery.

PURPOSE OF REVIEW: Peripheral nerve blocks are effective and safe modalities for perioperative analgesia. But it remains unclear what blocks are adequate for ambulatory surgeries, as well as the proper patient management before and after discharge. RECENT FINDINGS: Emerging nerve blocks have sparked interests due to ease to perform under ultrasound guidance and lower risks of adverse events. Some of these novel blocks are particularly suitable for ambulatory procedures, including but not limited to motor-sparing lower extremity nerve blocks and phrenic-sparing nerve blocks for shoulder surgeries. The adoption of peripheral nerve block into outpatient surgery is a multidisciplinary effort that encompasses appropriate patient choice, careful selection of nerve blocks that minimize potential adverse events after discharge, and proper patient follow-up until block effects resolve.

Ultrasound Image Quality Comparison Between a Handheld Ultrasound Transducer and Mid-Range Ultrasound Machine.

Objectives: Not all labor and delivery floors are equipped with ultrasound machines which can serve the needs of both obstetricians and anesthesiologists. This cross-sectional, blinded, randomized observational study compares the image resolution (RES), detail (DET), and quality (IQ) acquired by a handheld ultrasound, the Butterfly iQ, and a mid-range mobile device, the Sonosite M-turbo US (SU), to evaluate their use as a shared resource. Methods: Seventy-four pairs of ultrasound images were obtained for different imaging purposes: 29 for spine (Sp), 15 for transversus abdominis plane (TAP) and 30 for diagnostic obstetrics (OB) purposes. Each location was scanned by both the handheld and mid-range machine, resulting in 148 images. The images were graded by three blinded experienced sonographers on a 10-point Likert scale. Results: The mean difference for Sp imaging favored the handheld device (RES: -0.6 [(95% CI -1.1, -0.1), p = 0.017], DET: -0.8 [(95% CI -1.2, -0.3), p = 0.001] and IQ: -0.9 [95% CI-1.3, -0.4, p = 0.001]). For the TAP images, there was no statistical difference in RES or IQ, but DET was favored in the handheld device (-0.8 [(95% CI-1.2, -0.5), p < 0.001]). For OB images, the SU was favored over the handheld device with RES, DET and IQ with mean differences of 1.7 [(95% CI 1.2, 2.1), p < 0.001], 1.6 [(95% CI 1.2, 2.0], p < 0.001] and 1.1 [(95% CI 0.7, 1.5]), p < 0.001), respectively. Conclusions: Where resources are limited, a handheld ultrasound may be considered as a potential low-cost alternative to a more expensive ultrasound machine for point of care ultrasonography, better suited to anesthetic vs. diagnostic obstetrical indications.

A Practical Analgesia Approach to Fragility Hip Fracture: A Single-Center, Retrospective, Cohort Study on Femoral Nerve Block.

OBJECTIVE: To determine whether an effective opioid-sparing pain control modality is desirable for an aging population. DESIGN: Retrospective observational study SETTING:: Academic medical center PATIENTS:: 192 patients with various types of fragility hip fractures INTERVENTION:: A single-injection femoral nerve block (FNB) MAIN OUTCOME MEASUREMENTS:: Pain score, opioid consumption RESULTS:: We observed statistically significant effects of FNB on visual analogue scale pain score and the rate of opioid consumption diminution in all commonly encountered types of fragility hip fractures. The pain score reduction by FNB in subcapital femoral neck fracture, transcervical femoral neck facture, and intertrochanteric fracture are all statistically significant (P < 0.0001). There was a statistically more significant pain score reduction in intracapsular fractures than in extracapsular fractures (P = 0.006). On average, the hip fracture patients required 0.9 and 0.1 mg morphine equivalent/hour before and after FNB block placement. This decrease in opioid consumption when calculated per unit time was statistically significant in subcapital femoral neck fracture, transcervical femoral neck facture, and intertrochanteric fracture (P < 0.0001). There were no complications related to FNB placement. CONCLUSIONS: FNB is a sustainable, safe, and useful analgesic modality for commonly encountered fragility hip fractures. LEVEL OF EVIDENCE: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.