Feeding in mixoplankton enhances phototrophy increasing bloom-induced pH changes with ocean acidification.

Plankton phototrophy consumes CO2, increasing seawater pH, while heterotrophy does the converse. Elevation of pH (>8.5) during coastal blooms becomes increasingly deleterious for plankton. Mixoplankton, which can be important bloom-formers, engage in both photoautotrophy and phagoheterotrophy; in theory, this activity could create a relatively stable pH environment for plankton growth. Using a systems biology modelling approach, we explored whether different mixoplankton functional groups could modulate the environmental pH compared to the extreme activities of phototrophic phytoplankton and heterotrophic zooplankton. Activities by most mixoplankton groups do not stabilize seawater pH. Through access to additional nutrient streams from internal recycling with phagotrophy, mixoplankton phototrophy is enhanced, elevating pH; this is especially so for constitutive and plastidic specialist non-constitutive mixoplankton. Mixoplankton blooms can exceed the size of phytoplankton blooms; the synergisms of mixoplankton physiology, accessing nutrition via phagotrophy as well as from inorganic sources, enhance or augment primary production rather than depressing it. Ocean acidification will thus enable larger coastal mixoplankton blooms to form before basification becomes detrimental. The dynamics of such bloom developments will depend on whether the mixoplankton are consuming heterotrophs and/or phototrophs and how the plankton community succession evolves.

Mucus-Trap-Assisted Feeding Is a Common Strategy of the Small Mixoplanktonic Prorocentrum pervagatum and P. cordatum (Prorocentrales, Dinophyceae).

Prorocentrum comprises a diverse group of bloom-forming dinophytes with a worldwide distribution. Although photosynthetic, mixoplanktonic phagotrophy has also been described. Recently, the small P. cf. balticum was shown to use a remarkable feeding strategy by crafting globular mucus traps to capture and immobilize potential prey. Here we present evidence showing that two additional related species, the recently described P. pervagatum and the cosmopolitan bloom-forming P. cordatum, also produce large (80-120 µm) mucus traps supporting their mixoplanktonic activity. Prey are captured within the traps either through passive entanglement upon contact with the outside surface, or through active water movement created by rotating Prorocentrum cells eddying particles to the inside surface where trapped live prey cells became immobilized. Entrapment in mucus assisted deployment into the prey of a peduncle extruded from the apical area of the Prorocentrum cell. Phagotrophy by P. pervagatum supported faster growth compared to unfed controls and time series quantification of food vacuoles revealed ingestion rates of ca. 10-12 Teleaulax prey cells day-1. Model calculations show clear advantages of deploying a mucus trap for increasing prey encounter rates. This study demonstrates that the large size and immobilization properties of mucus traps successfully increase the availability of prey for small Prorocentrum species, whose peduncle feeding mode impedes consumption of actively moving prey, and that this strategy is common among certain clades of small planktonic Prorocentrum species.

Clinical Validation of an Adult-acquired Buried Penis Classification System Based on Standardized Evaluation of the Penis, Abdomen, and Scrotum.

OBJECTIVE: To clinically validate a previously developed adult-acquired buried penis (AABP) classification system that is based on a standardized preoperative physical examination that subtypes patients by their penile skin/escutcheon complex (P), abdominal pannus (A), and scrotal skin (S). METHODS: The Trauma and Urologic Reconstruction Network of Surgeons (TURNS) database was used to create an AABP cohort. Patients were retrospectively classified using the previously described PAS classification system. The frequency of subtypes, surgical methods utilized for AABP repair, and correlations between PAS classification and surgery subtypes were analyzed. RESULTS: The final cohort consisted of 101 patients from 10 institutions. Interrater reliability between two reviewers was excellent (κ = 0.95). The most common subtypes were P2c (contributory escutcheon+insufficient penile skin; 27%) and P2a (contributory escutcheon+sufficient penile skin; 21%) for penile subtypes, A0 (no pannus; 41%) and A1 (noncontributory pannus; 39%) for abdominal subtypes, and S0 (normal scrotal skin with preserved scrotal sulcus; 71%) for scrotal subtypes. AABP repair procedures included escutcheonectomy (n = 59, 55%), scrotoplasty (n = 51, 48%), split-thickness skin grafting (n = 50, 47%), penile skin excision (n = 47, 44%) and panniculectomy (n = 7, 7%). P, A, and S subtypes were strongly associated with specific AABP surgical techniques. CONCLUSION: The PAS classification schema adequately describes AABP heterogeneity, is reproducible among observers, and correlates well with AABP surgery types. Future work will focus on how PAS subtypes affect both surgical and patient-centered outcomes.

Low rates of bacterivory enhances phototrophy and competitive advantage for mixoplankton growing in oligotrophic waters.

With climate change, oceans are becoming increasingly nutrient limited, favouring growth of prokaryotic picoplankton at the expense of the larger protist plankton whose growth support higher trophic levels. Constitutive mixoplankton (CM), microalgal plankton with innate phototrophic capability coupled with phagotrophy, graze on these picoplankton, indirectly exploiting the excellent resource acquisition abilities of the prokaryotes. However, feeding rates can be very low (e.g., a few bacteria d-1). For the first time, the significance of such low consumption rates has been quantified. We find that while prokaryote-carbon (C) supply to CM grown at non-limiting light was so low that it may appear insignificant (< 10%), contributions of nitrogen (N) and phosphorus (P) from ingestions of 1-12 prokaryotes d-1 were significant. Under limiting light, contributions of ingested C increased, also raising the contributions of N and P. The order of nutritional importance for CM growth from predation was P > N > C. Further, provision of N through internal recycling of ingested prey-N stimulates C-fixation through photosynthesis. Importantly, coupled photo-phago-mixoplanktonic activity improved CM resource affinities for both inorganic and prey-bound nutrients, enhancing the nutritional status and competitiveness of mixoplankton. With warming oceans, with increased prokaryote abundance, we expect CM to exhibit more phagotrophy.

The Mixoplankton Database (MDB): Diversity of photo-phago-trophic plankton in form, function, and distribution across the global ocean.

Protist plankton are major members of open-water marine food webs. Traditionally divided between phototrophic phytoplankton and phagotrophic zooplankton, recent research shows many actually combine phototrophy and phagotrophy in the one cell; these protists are the "mixoplankton." Under the mixoplankton paradigm, "phytoplankton" are incapable of phagotrophy (diatoms being exemplars), while "zooplankton" are incapable of phototrophy. This revision restructures marine food webs, from regional to global levels. Here, we present the first comprehensive database of marine mixoplankton, bringing together extant knowledge of the identity, allometry, physiology, and trophic interactivity of these organisms. This mixoplankton database (MDB) will aid researchers that confront difficulties in characterizing life traits of protist plankton, and it will benefit modelers needing to better appreciate ecology of these organisms with their complex functional and allometric predator-prey interactions. The MDB also identifies knowledge gaps, including the need to better understand, for different mixoplankton functional types, sources of nutrition (use of nitrate, prey types, and nutritional states), and to obtain vital rates (e.g. growth, photosynthesis, ingestion, factors affecting photo' vs. phago' -trophy). It is now possible to revisit and re-classify protistan "phytoplankton" and "zooplankton" in extant databases of plankton life forms so as to clarify their roles in marine ecosystems.

Thermal Infrared Camera Imaging to Aid Necrotizing Soft Tissue Infections of the Genitalia Management.

OBJECTIVE: To determine if imaging with a thermal infrared camera might aid clinicians with diagnosis of equivocal necrotizing soft tissue infections of the genitalia (NSTIG) cases and help surgeons when determining appropriate surgical resection margins. MATERIALS/METHODS: For 12 months at a single tertiary academic hospital, sequential patients already undergoing exploration for acute scrotum had preoperative photography with an infrared camera (FLIR C5). We compared infrared and standard preoperative photography with operative reports and postoperative photography to investigate if infrared photography corresponded with operative findings in severe scrotal infections-specifically the viability of the skin and the ultimate surgical resection margins. RESULTS: A total of 16 patients were included. The pre-operative infrared photos directly correlated with resection margins in 13 of 16 (81%) patients. Notably, areas with a relatively lower (cooler) infrared intensity corresponded well to both visibly necrotic tissue when discrete and areas with large underlying fluid collections. Diffuse warm signal relative to surrounding skin correlated with cellulitis and viable skin. CONCLUSION: In this observational study, infrared photography corresponded well with physical exam and operative findings. There may be a role for augmented temperature photography in the diagnosis and triage of scrotal infections. More research with standardized temperature gating of infrared signal and controls with normal or nonacute scrotums are needed to elucidate the clinical utility for infrared photograph.

Adult-Acquired Buried Penis Classification and Surgical Management.

In this article, the authors discuss the epidemiology, pathophysiology, and initial work-up for men with adult-acquired buried penis syndrome (AABP). Given the significant heterogeneity of AABP, a classification system is proposed which classifies the condition by the status of the abdominal pannus, the escutcheon, the penile skin and the scrotal skin, and their respective fascial attachments. Classification is achieved by a uniform assessment of anatomy using the proposed standardized preoperative photos. Various surgical strategies to repair AABP are proposed which, importantly, should be in line with the patient-centered goals and also differ widely with the condition.

Management of Necrotizing Soft Tissue Infections (Fournier's Gangrene) and Surgical Reconstruction of Debridement Wound Defects.

In this article, the authors discuss the epidemiology, pathophysiology, and mechanism of spread of necrotizing soft-tissue infections of the genitalia, including classification schemas. The authors then discuss the acute clinical management of the disease, including suggestions for ways to improve surgical debridements (such that eventual reconstructions are simpler), ways to predict disease severity using laboratory, vital sign, and physical examination findings, and suggestions for initial antimicrobial treatments. Finally, reconstructive techniques and algorithms to ensure that the reconstructive goals of coverage, function, and cosmesis are met, are discussed, including the management of postoperative complications.

Favorable Outcomes With Early Component Separation, Primary Closure of Necrotizing Soft Tissue Infections of the Genitalia (Fournier's Gangrene) Debridement Wound Defects.

OBJECTIVE: To evaluate the efficacy of early necrotizing soft-tissue infections of the genitalia (NSTIG) component separation, primary wound closure (CSC). We hypothesized that early CSC would be safe, decrease the need for split-thickness skin grafting (STSG) and decrease wound convalescence time. MATERIALS/METHODS: Management of consecutive NSTIG patients from a single institution were evaluated. Three cohorts emerged: 1) those managed/closed by a reconstructive urologist (URO) using CSC principles (wide genital tissue mobilization with primary closure, when possible, +/- STSG), 2) those managed/closed by the general surgery/burn service, and 3) those managed conservatively with secondary closure. Total NSTIG anatomic extent (AE) was determined by assessing involvement of the penis, scrotum, perineum and suprapubic region, and ranged from 1 (<50% involvement of one area) to 8 (>50% involvement in all 4 areas). RESULTS: Of 84 FG patients meeting study criteria, 48 (57%) were closed primarily and 36 were left to heal by secondary intention. AE was greatest in patients managed by general surgery/burn service (4.5 ± 1.5), followed by URO (2.7 ± 1.8) and secondary intention cases (1.3 ± 0.5). Secondary procedure rates were similar between closure/non-closure cohorts (6.3% v 11%; P = 0.67). STSG use was predicted by wound size (though not time to closure)-specifically with suprapubic and/or penile wounds of >50% involvement. Wound convalescence time decreased by 64% when wounds were closed versus left open, controlling for AE. CONCLUSION: Early, same-admission primary closure of stable NSTIG wounds is safe and decreases wound convalescence time by over 60%.

Nephrostomy Balloon and Sheath Suprapubic Tube Placement-A Minimally Invasive Approach to Large Caliber Suprapubic Tube Placement.

Suprapubic tubes (SPT) are a vital tool in the management of complex urologic voiding conditions. There are numerous methods of SPT placement, each with pros/cons: peel-away kits are easy to place, but often have small caliber SPTs, that is, 12 or 14 Fr, prone to kinking, that require serial upsizing to achieve the desired caliber; open SPT placements permit an initial large caliber SPT but are more invasive, particularly in obese patients. This video demonstrates a minimally invasive technique for SPT placement in patients with preserved urethral access to the bladder that safely allows for initial, precise placement of large caliber (>20F) catheters using the Nephromax nephrostomy balloon/sheath (NBS-SPT). Technique: A 6″ 17G Tuohy spinal needle is placed percutaneously 3 cm above the pubis (generally in the abdominal crease), 1-2 cm off midline towards the side the patient prefers to keep the drainage bag. The needle is angled to enter the bladder dome in the midline, which is visualized cystoscopically with a full bladder. The angling will allow the catheter to lie flat and decrease kinking. The stylette is removed and a stiff wire is advanced. A 2 cm horizontal skin incision is made. A 24 Fr NBS is advanced into the bladder under vision and inflated to 18 ATM. The balloon is then deflated/removed and the SPT is passed through the sheath into the bladder. Once inflated, the sheath removed and the SPT is secured to the skin. Study: A 10-year retrospective review of NBS-SPT placements at a single institution was performed, analyzing patient characteristics, surgical details, and surgical outcomes. NBS-SPT was attempted 65 times over the study period. The most common indications included acquired/congenital neurogenic bladder (48%) and urinary retention (25%). A simultaneous additional procedure (eg, cytolitholapaxy, bladder neck incision) was performed in 31% of NBS-SPTs. Median body mass index was 29.5 (interquartile range: 25-33.9) and 34% had prior abdominal procedures. Median operative time (NBS-SPT only) was 16 minutes (interquartile range: 14-20). All procedures were successful in placing a catheter 20F. Thirty-day Clavien I/II complication rate was 18% (hematuria n = 3; cellulitis n = 4; early SPT exchange for clogging n = 5); A Clavien IIIb complication occurred in one patient with hematuria requiring fulguration. First SPT exchange in clinic was successful in 95%, with 2 patients requiring replacement under anesthesia. NBS-SPT is a safe and efficient minimally invasive technique for initial, precise placement of large caliber SPT in patients with urethral bladder access.

Deuterium in marine organic biomarkers: toward a new tool for quantifying aquatic mixotrophy.

The traditional separation between primary producers (autotrophs) and consumers (heterotrophs) at the base of the marine food web is being increasingly replaced by the paradigm that mixoplankton, planktonic protists with the nutritional ability to use both phago(hetero)trophy and photo(auto)trophy to access energy are widespread globally. Thus, many 'phytoplankton' eat, while 50% of 'protozooplankton' also perform photosynthesis. Mixotrophy may enhance primary production, biomass transfer to higher trophic levels and the efficiency of the biological pump to sequester atmospheric CO2 into the deep ocean. Although this view is gaining traction, science lacks a tool to quantify the relative contributions of autotrophy and heterotrophy in planktonic protists. This hinders our understanding of their impacts on carbon cycling within marine pelagic ecosystems. It has been shown that the hydrogen (H) isotopic signature of lipids is uniquely sensitive to heterotrophy relative to autotrophy in plants and bacteria. Here, we explored whether it is also sensitive to the trophic status in protists. The new understanding of H isotope signature of lipid biomarkers suggests it offers great potential as a novel tool for quantifying the prevalence of mixotrophy in diverse marine microorganisms and thus for investigating the implications of the 'mixoplankton' paradigm.

'Boom-and-busted' dynamics of phytoplankton-virus interactions explain the paradox of the plankton.

Rapid virus proliferation can exert a powerful control on phytoplankton host populations, playing a significant role in marine biogeochemistry and ecology. We explore how marine lytic viruses impact phytoplankton succession, affecting host and nonhost populations. Using an in silico food web we conducted simulation experiments under a range of different abiotic and biotic conditions, exploring virus-host-grazer interactions and manipulating competition, allometry, motility and cyst cycles. Virus-host and predator-prey interactions, and interactions with competitors, generate bloom dynamics with a pronounced 'boom-and-busted' dynamic (BBeD) which leads to the suppression of otherwise potentially successful phytoplankton species. The BBeD is less pronounced at low nutrient loading through distancing of phytoplankton hosts, while high sediment loading and high nonhost biomass decrease the abundance of viruses through adsorption. Larger hosts are inherently more distanced, but motility increases virus attack, while cyst cycles promote spatial and temporal distancing. Virus control of phytoplankton bloom development appears more important than virus-induced termination of those blooms. This affects plankton succession - not only the growth of species infected by the virus, but also those that compete for the same resources and are collectively subjected to common grazer control. The role of viruses in structuring plankton communities via BBeDs can thus provide an explanation for the paradox of the plankton.

Prospective Comparison of Opioid vs Nonopioid Pain Regimen After Ureteroscopy.

Objective: We wanted to evaluate two new treatment phases within our practice, including a nonopioid pathway, to determine the effect on opioid usage, health care utilization, and pain following ureteroscopy. Methods: Patients undergoing ureteroscopic lithotripsy were enrolled in a study utilizing text messaging to evaluate postoperative pain and opioid usage. Our historical postoperative pain regimen included #30 oxycodone. Patients in the N15 cohort were given improved counseling, preanesthesia acetaminophen, and #15 oxycodone. With further experience, narcotics were removed entirely from our postoperative care plan (N0) and replaced with a nonopioid multimodal regimen. Results: There were 61 and 58 patients in cohorts N15 and N0, respectively, with no difference in demographics, stone, or procedure details between each cohort. No difference in pain scores was detected between the N15 and N0 cohorts (p = 0.14). The median time to pain resolution was postoperative day (POD) 4 for cohort N15 and POD 3 for cohort N0 (p = 0.06). In the N0 cohort, nine patients required postoperative narcotics (15.5%; average of 2.4 pills/patient). There was no significant difference in emergency department visits, phone calls, or clinic visits (p = 0.17) between each cohort. Conclusions: Patients undergoing ureteroscopy have adequate postoperative pain control with a nonopioid treatment regimen, although some patients will still ultimately require narcotics.

Number of cores needed to diagnose prostate cancer during MRI targeted biopsy decreases after the learning curve.

INTRODUCTION: We hypothesized that the number of cores needed to detect prostate cancer would decrease with increasing MRI-targeted biopsy (TBx) experience. METHODS: All patients undergoing TBx at our institution from May 2017 to August 2019 were enrolled in a prospectively maintained database. Five biopsy cores were obtained from each lesion ≥3 on PI-RADS v2.0 followed by a systematic 12-core biopsy. To assess learning curve, the study population was divided into quartiles by sequential biopsies. Clinically significant prostate cancer (csPC) was defined as Gleason Grade Group 2 or higher. RESULTS: 377 patients underwent prostate biopsy (533 lesions); 233 lesions (44%) were positive for prostate cancer and 173 lesions (32%) were csPC. There was a significant decline in the number of cores required for diagnosing any cancer (P < 0.001) and csPC (P < 0.05) after the first quartile. There was no difference when stratifying by PI-RADS score or lesion volume. Within the first quartile, limiting the biopsy to 3 cores would miss 16.2% of csPC, decreasing to 6.6% after approximately 100 patients. CONCLUSION: MRI TBx is associated with a learning curve of approximately 100 cases. Four or 5 cores should be considered during the initial experience, but thereafter, 3 cores per lesion is sufficient to detect csPC.

Mixoplankton interferences in dilution grazing experiments.

It remains unclear as to how mixoplankton (coupled phototrophy and phagotrophy in one cell) affects the estimation of grazing rates obtained from the widely used dilution grazing technique. To address this issue, we prepared laboratory-controlled dilution experiments with known mixtures of phyto-, protozoo-, and mixoplankton, operated under different light regimes and species combinations. Our results evidenced that chlorophyll is an inadequate proxy for phytoplankton when mixoplankton are present. Conversely, species-specific cellular counts could assist (although not fully solve) in the integration of mixoplanktonic activity in a dilution experiment. Moreover, cell counts can expose prey selectivity patterns and intraguild interactions among grazers. Our results also demonstrated that whole community approaches mimic reality better than single-species laboratory experiments. We also confirmed that light is required for protozoo- and mixoplankton to correctly express their feeding activity, and that overall diurnal grazing is higher than nocturnal. Thus, we recommend that a detailed examination of initial and final plankton communities should become routine in dilution experiments, and that incubations should preferably be started at the beginning of both day and night periods. Finally, we hypothesize that in silico approaches may help disentangle the contribution of mixoplankton to the community grazing of a given system.

Optimizing MRI-targeted prostate biopsy: the diagnostic benefit of additional targeted biopsy cores.

INTRODUCTION: The optimal number of biopsy cores to obtain during MRI-targeted prostate biopsy remains ill-defined. This study sought to determine the optimal number of targeted biopsy cores to obtain from a region of interest to maximize detection of clinically significant prostate cancer. MATERIALS AND METHODS: Consecutive patients undergoing MRI-targeted prostate biopsy at a single institution that newly implemented a targeted biopsy pathway from May 2017 to February 2018 were prospectively enrolled. Five biopsy cores were obtained and individually analyzed from each region rated ≥3 on PI-RADS v2.0 to determine the incremental diagnostic benefit of each additional targeted biopsy core. Variables associated with increasing Grade Group from the first to fifth biopsy core were assessed. RESULTS: One hundred and four patients (79% for elevated PSA) were enrolled, 82% of which had a prior biopsy. Men with a PI-RADS >3 lesion were more likely to have pathologic upgrading with additional targeted biopsy cores (OR:4.76; 95% CI:2.34-9.70; P < 0.0001), particularly to Grade Group ≥2 (OR:5.16; 95% CI:2.17-12.29; P = 0.0002), compared to men with PI-RADS 3 lesions. Detection of clinically significant cancer increased from 26% to 44% to 52% when comparing the first, third, and fifth biopsy cores amongst men with a PI-RADS >3 lesion and from 1% to 4% to 9% for PI-RADS 3 lesions. Urinary retention was the most common complication, occurring in 6 (5.7%) patients. CONCLUSION: Clinically significant prostate cancer detection is improved with increased number of MRI-targeted biopsy cores, particularly for urologists early in their learning curve.

Exploring evolution of maximum growth rates in plankton.

Evolution has direct and indirect consequences on species-species interactions and the environment. However, Earth systems models describing planktonic activity invariably fail to explicitly consider organism evolution. Here we simulate the evolution of the single most important physiological characteristic of any organism as described in models-its maximum growth rate (µm). Using a low-computational-cost approach, we incorporate the evolution of µm for each of the plankton components in a simple Nutrient-Phytoplankton-Zooplankton -style model such that the fitness advantages and disadvantages in possessing a high µm evolve to become balanced. The model allows an exploration of parameter ranges leading to stresses, which drive the evolution of µm. In applications of the method we show that simulations of climate change give very different projections when the evolution of µm is considered. Thus, production may decline as evolution reshapes growth and trophic dynamics. Additionally, predictions of extinction of species may be overstated in simulations lacking evolution as the ability to evolve under changing environmental conditions supports evolutionary rescue. The model explains why organisms evolved for mature ecosystems (e.g. temperate summer, reliant on local nutrient recycling or mixotrophy), express lower maximum growth rates than do organisms evolved for immature ecosystems (e.g. temperate spring, high resource availability).