From flare to care: Dermatologists' impact on pediatric atopic dermatitis hospital admissions.

BACKGROUND/OBJECTIVES: Atopic dermatitis (AD) is a common chronic skin disease in the pediatric population; however, rates of admissions for flares in patients established with dermatology compared to those that are not established have not been fully assessed in prior studies. METHODS: We reviewed electronic medical records of patients hospitalized (billing codes 99221-99223, 99217) with diagnoses encompassing AD, eczema, and dermatitis (ICD-10 codes L20.8-L20.9, L30.8-L30.9) between January 1, 2011, and December 31, 2021, at University Hospitals (UH) in Cleveland, Ohio. Patients were considered established with dermatology if they had been seen by a dermatology provider within 6 months prior to admission. Statistical analysis was performed using chi-square goodness of fit. RESULTS: A total of 95 patient encounters met criteria for inclusion. Fifteen (15.8%) patients were established with dermatology at the time of admission and 80 (84.2%) were not. The chi-square value (x2 = 44.74) was greater than the critical value of 10.828 at one degree of freedom (p < .001). There were 8 patients who had more than one admission for atopic dermatitis flares; 2 of these patients were established with dermatology prior to their first admission, and 4 were established at the time of the second admission. CONCLUSION: The majority of patients admitted with AD flare were not established with dermatology. Many of these patients lived in a low socioeconomic area and missed follow-up appointments. Increasing access to dermatologic care for patients with atopic dermatitis, especially in lower-income areas, could aid in decreasing atopic dermatitis-related hospitalizations.

Multicenter evaluation of the Vetscan Imagyst system using Ocus 40 and EasyScan One scanners to detect gastrointestinal parasites in feces of dogs and cats.

The Vetscan Imagyst system (Zoetis) is a novel, artificial intelligence-driven detection tool that can assist veterinarians in the identification of enteric parasites in dogs and cats. This system consists of a sample preparation device, an automated digital microscope scanner, and a deep-learning algorithm. The EasyScan One scanner (Motic) has had good diagnostic performance compared with manual examinations by experts; however, there are drawbacks when used in veterinary practices in which space for equipment is often limited. To improve the usability of this system, we evaluated an additional scanner, the Ocus 40 (Grundium). Our objectives were to 1) qualitatively evaluate the performance of the Vetscan Imagyst system with the Ocus 40 scanner for identifying Ancylostoma, Toxocara, and Trichuris eggs, Cystoisospora oocysts, and Giardia cysts in canine and feline fecal samples, and 2) expand the assessment of the performance of the Vetscan Imagyst system paired with either the Ocus 40 or EasyScan One scanner to include a larger dataset of 2,191 fecal samples obtained from 4 geographic regions of the United States. When tested with 852 canine and feline fecal samples collected from different geographic regions, the performance of the Vetscan Imagyst system combined with the Ocus 40 scanner was correlated closely with manual evaluations by experts. Sensitivities were 80.0‒97.0% and specificities were 93.7‒100.0% across the targeted parasites. When tested with 1,339 fecal samples, the Vetscan Imagyst system paired with the EasyScan One scanner successfully identified the targeted parasite stages; sensitivities were 73.6‒96.4% and specificities were 79.7‒100.0%.

Seafloor Incubation Experiment with Deep-Sea Hydrothermal Vent Fluid Reveals Effect of Pressure and Lag Time on Autotrophic Microbial Communities.

Depressurization and sample processing delays may impact the outcome of shipboard microbial incubations of samples collected from the deep sea. To address this knowledge gap, we developed a remotely operated vehicle (ROV)-powered incubator instrument to carry out and compare results from in situ and shipboard RNA stable isotope probing (RNA-SIP) experiments to identify the key chemolithoautotrophic microbes and metabolisms in diffuse, low-temperature venting fluids from Axial Seamount. All the incubations showed microbial uptake of labeled bicarbonate primarily by thermophilic autotrophic Epsilonbacteraeota that oxidized hydrogen coupled with nitrate reduction. However, the in situ seafloor incubations showed higher abundances of transcripts annotated for aerobic processes, suggesting that oxygen was lost from the hydrothermal fluid samples prior to shipboard analysis. Furthermore, transcripts for thermal stress proteins such as heat shock chaperones and proteases were significantly more abundant in the shipboard incubations, suggesting that depressurization induced thermal stress in the metabolically active microbes in these incubations. Together, the results indicate that while the autotrophic microbial communities in the shipboard and seafloor experiments behaved similarly, there were distinct differences that provide new insight into the activities of natural microbial assemblages under nearly native conditions in the ocean.IMPORTANCE Diverse microbial communities drive biogeochemical cycles in Earth's ocean, yet studying these organisms and processes is often limited by technological capabilities, especially in the deep ocean. In this study, we used a novel marine microbial incubator instrument capable of in situ experimentation to investigate microbial primary producers at deep-sea hydrothermal vents. We carried out identical stable isotope probing experiments coupled to RNA sequencing both on the seafloor and on the ship to examine thermophilic, microbial autotrophs in venting fluids from an active submarine volcano. Our results indicate that microbial communities were significantly impacted by the effects of depressurization and sample processing delays, with shipboard microbial communities being more stressed than seafloor incubations. Differences in metabolism were also apparent and are likely linked to the chemistry of the fluid at the beginning of the experiment. Microbial experimentation in the natural habitat provides new insights into understanding microbial activities in the ocean.

Further evaluation and validation of the VETSCAN IMAGYST: in-clinic feline and canine fecal parasite detection system integrated with a deep learning algorithm.

BACKGROUND: Fecal examinations in pet cats and dogs are key components of routine veterinary practice; however, their accuracy is influenced by diagnostic methodologies and the experience level of personnel performing the tests. The VETSCAN IMAGYST system was developed to provide simpler and easier fecal examinations which are less influenced by examiners' skills. This system consists of three components: a sample preparation device, an automated microscope scanner, and analysis software. The objectives of this study were to qualitatively evaluate the performance of the VETSCAN IMAGYST system on feline parasites (Ancylostoma and Toxocara cati) and protozoan parasites (Cystoisospora and Giardia) and to assess and compare the performance of the VETSCAN IMAGYST centrifugal flotation method to reference centrifugal and passive flotation methods. METHODS: To evaluate the diagnostic performance of the scanning and algorithmic components of the VETSCAN IMAGYST system, fecal slides were prepared by the VETSCAN IMAGYST centrifugal flotation technique with pre-screened fecal samples collected from dogs and cats and examined by both an algorithm and parasitologists. To assess the performance of the VETSCAN IMAGYST centrifugal flotation technique, diagnostic sensitivity and specificity were calculated and compared to those of conventional flotation techniques. RESULTS: The performance of the VETSCAN IMAGYST algorithm closely correlated with evaluations by parasitologists, with sensitivity of 75.8-100% and specificity of 93.1-100% across the targeted parasites. For samples with 50 eggs or less per slide, Lin's concordance correlation coefficients ranged from 0.70 to 0.95 across the targeted parasites. The results of the VETSCAN IMAGYST centrifugal flotation method correlated well with those of the conventional centrifugal flotation method across the targeted parasites: sensitivity of 65.7-100% and specificity of 97.6-100%. Similar results were observed for the conventional passive flotation method compared to the conventional centrifugal flotation method: sensitivity of 56.4-91.7% and specificity of 99.4-100%. CONCLUSIONS: The VETSCAN IMAGYST scanning and algorithmic systems with the VETSCAN IMAGYST fecal preparation technique demonstrated a similar qualitative performance to the parasitologists' examinations with conventional fecal flotation techniques. Given the deep learning nature of the VETSCAN IMAGYST system, its performance is expected to improve over time, enabling it to be utilized in veterinary clinics to perform fecal examinations accurately and efficiently.

Evaluation of the VETSCAN IMAGYST: an in-clinic canine and feline fecal parasite detection system integrated with a deep learning algorithm.

BACKGROUND: Fecal examination is an important component of routine companion animal wellness exams. Sensitivity and specificity of fecal examinations, however, are influenced by sample preparation methodologies and the level of training and experience of personnel who read fecal slides. The VETSCAN IMAGYST system consists of three components: a sample preparation device, a commercially available scanner, and an analysis software. The VETSCAN IMAGYST automated scanner and cloud-based, deep learning algorithm, locates, classifies, and identifies parasite eggs found on fecal microscopic slides. The main study objectives were (i) to qualitatively evaluate the capabilities of the VETSCAN IMAGYST screening system and (ii) to assess and compare the performance of the VETSCAN IMAGYST fecal preparation methods to conventional fecal flotation techniques. METHODS: To assess the capabilities of VETSCAN IMAGYST screening components, fecal slides were prepared by the VETSCAN IMAGYST centrifugal and passive flotation techniques with 100 pre-screened fecal samples collected from dogs and cats and examined by both the algorithm and parasitologists. To determine the diagnostic sensitivity and specificity of the VETSCAN IMAGYST sample preparation techniques, fecal flotation slides were prepared by four different techniques (VETSCAN IMAGYST centrifugal and passive flotations, conventional centrifugal flotation, and passive flotation using OVASSAY® Plus) and examined by parasitologists. Additionally, required sample preparation and scanning times were estimated on a subset of samples to evaluate VETSCAN IMAGYST ease-of-use. RESULTS: The algorithm performance of the VETSCAN IMAGYST closely matched that of the parasitologists, with Pearson's correlation coefficient (r) ranging from 0.83-0.99 across four taxa of parasites, Ancylostoma, Toxocara, Trichuris and Taeniidae. Both VETSCAN IMAGYST centrifugal and passive flotation methods correlated well with conventional preparation methods on all targeted parasites (diagnostic sensitivity of 75.8-100%, specificity of 91.8-100%, qualitative agreement between methods of 93.8-94.5%). Sample preparation, slide scan and image analysis were completed within 10-14 min by VETSCAN IMAGYST centrifugal and passive flotations, respectively. CONCLUSIONS: The VETSCAN IMAGYST scanning system with the VETSCAN IMAGYST sample preparation methods demonstrated a qualitative match in comparison to the results of parasitologists' examinations with conventional fecal flotation techniques. The VETSCAN IMAGYST is an easy-to-use, next generation qualitative and possibly quantitative diagnostic platform that brings expert clinical results into the hands of veterinary clinics.

Chondrogenic, hypertrophic, and osteochondral differentiation of human mesenchymal stem cells on three-dimensionally woven scaffolds.

The development of mechanically functional cartilage and bone tissue constructs of clinically relevant size, as well as their integration with native tissues, remains an important challenge for regenerative medicine. The objective of this study was to assess adult human mesenchymal stem cells (MSCs) in large, three-dimensionally woven poly(ε-caprolactone; PCL) scaffolds in proximity to viable bone, both in a nude rat subcutaneous pouch model and under simulated conditions in vitro. In Study I, various scaffold permutations-PCL alone, PCL-bone, "point-of-care" seeded MSC-PCL-bone, and chondrogenically precultured Ch-MSC-PCL-bone constructs-were implanted in a dorsal, ectopic pouch in a nude rat. After 8 weeks, only cells in the Ch-MSC-PCL constructs exhibited both chondrogenic and osteogenic gene expression profiles. Notably, although both tissue profiles were present, constructs that had been chondrogenically precultured prior to implantation showed a loss of glycosaminoglycan (GAG) as well as the presence of mineralization along with the formation of trabecula-like structures. In Study II of the study, the GAG loss and mineralization observed in Study I in vivo were recapitulated in vitro by the presence of either nearby bone or osteogenic culture medium additives but were prevented by a continued presence of chondrogenic medium additives. These data suggest conditions under which adult human stem cells in combination with polymer scaffolds synthesize functional and phenotypically distinct tissues based on the environmental conditions and highlight the potential influence that paracrine factors from adjacent bone may have on MSC fate, once implanted in vivo for chondral or osteochondral repair.

Fluid geochemistry, local hydrology, and metabolic activity define methanogen community size and composition in deep-sea hydrothermal vents.

The size and biogeochemical impact of the subseafloor biosphere in oceanic crust remain largely unknown due to sampling limitations. We used reactive transport modeling to estimate the size of the subseafloor methanogen population, volume of crust occupied, fluid residence time, and nature of the subsurface mixing zone for two low-temperature hydrothermal vents at Axial Seamount. Monod CH4 production kinetics based on chemostat H2 availability and batch-culture Arrhenius growth kinetics for the hyperthermophile Methanocaldococcus jannaschii and thermophile Methanothermococcus thermolithotrophicus were used to develop and parameterize a reactive transport model, which was constrained by field measurements of H2, CH4, and metagenome methanogen concentration estimates in 20-40 °C hydrothermal fluids. Model results showed that hyperthermophilic methanogens dominate in systems where a narrow flow path geometry is maintained, while thermophilic methanogens dominate in systems where the flow geometry expands. At Axial Seamount, the residence time of fluid below the surface was 29-33 h. Only 1011 methanogenic cells occupying 1.8-18 m3 of ocean crust per m2 of vent seafloor area were needed to produce the observed CH4 anomalies. We show that variations in local geology at diffuse vents can create fluid flow paths that are stable over space and time, harboring persistent and distinct microbial communities.

Anisotropic architecture and electrical stimulation enhance neuron cell behaviour on a tough graphene embedded PVA: alginate fibrous scaffold.

Tough scaffolds comprised of aligned and conductive fibers are promising for peripheral nerve regeneration due to their unique mechanical and electrical properties. Several studies have confirmed that electrical stimulation can control the axonal extension in vitro. However, the stimulatory effects of scaffold architecture and electrical stimulation have not yet been investigated in detail. Here, we assessed a comparison between aligned and random fibers made of graphene (Gr) embedded sodium alginate (SA) polyvinyl alcohol (PVA) (Gr-AP scaffolds) for peripheral nerve engineering. The effects of applied electrical stimulation and orientation of the fabricated fibers on the in vitro attachment, alignment, and proliferation of PC12 cells (a rat neuronal cell line) were investigated. The results revealed that the aligned fibrous Gr-AP scaffolds closely mimicked the anisotropic structure of the native sciatic nerve. Aligned fibrous Gr-AP scaffolds significantly improved mechanical properties as well as cell-scaffold integration compared to random fibrous scaffolds. In addition, electrical stimulation significantly improved PC12 cell proliferation. In summary, our findings revealed that aligned fibrous Gr-AP scaffolds offered superior mechanical characteristics and structural properties that enhanced neural cell-substrate interactions, resulting in a promising construct for nerve tissue regeneration.

Spatially distinct, temporally stable microbial populations mediate biogeochemical cycling at and below the seafloor in hydrothermal vent fluids.

At deep-sea hydrothermal vents, microbial communities thrive across geochemical gradients above, at, and below the seafloor. In this study, we determined the gene content and transcription patterns of microbial communities and specific populations to understand the taxonomy and metabolism both spatially and temporally across geochemically different diffuse fluid hydrothermal vents. Vent fluids were examined via metagenomic, metatranscriptomic, genomic binning, and geochemical analyses from Axial Seamount, an active submarine volcano on the Juan de Fuca Ridge in the NE Pacific Ocean, from 2013 to 2015 at three different vents: Anemone, Marker 33, and Marker 113. Results showed that individual vent sites maintained microbial communities and specific populations over time, but with spatially distinct taxonomic, metabolic potential, and gene transcription profiles. The geochemistry and physical structure of each vent both played important roles in shaping the dominant organisms and metabolisms present at each site. Genomic binning identified key populations of SUP05, Aquificales and methanogenic archaea carrying out important transformations of carbon, sulfur, hydrogen, and nitrogen, with groups that appear unique to individual sites. This work highlights the connection between microbial metabolic processes, fluid chemistry, and microbial population dynamics at and below the seafloor and increases understanding of the role of hydrothermal vent microbial communities in deep ocean biogeochemical cycles.

Current practice of antibiotic utilization for renal colic in the emergency room

ABSTRACT Introduction Urinalysis (UA) in the emergency setting for patients with nephrolithiasis produces potentially confusing results leading to treatment of presumed urinary tract infections (UTIs). Our objective was to evaluate the use of antibiotics in patients with nephrolithiasis in a large network of emergency departments (EDs). Methods A retrospective analysis of all ED visits associated with an ICD-9 diagnosis of nephrolithiasis and a CT scan between 2010 and 2013 was performed. Urinalysis data, the use of IV and PO antibiotics during the ED visit and at discharge were assessed. The presence of fever, elevated serum WBCs, >5 WBCs per hpf, and/or dip positive nitrites were used as appropriate criteria for antibiotic use. Results Urinalysis data were available for 3,518 (70%) of 5,035 patients with an ED diagnosis of nephrolithiasis and CT imaging. Of these visits, 237 patients had positive nitrites (6.7%) and 864 had >5 WBCs per hpf (24.6%) with 158 (4.5%) having both findings for a total of 943 patients. Intravenous antibiotics were given to 244 patients (25.9%) and oral antibiotics were given to 629 patients (66.7 %) with positive UA findings. Of the 2,440 patients with a negative UA and no leukocytosis or fever, 86 patients (3.5%) received IV antibiotics and 533 patients (21.8%) received PO antibiotics upon discharge. Conclusions Proper treatment of nephrolithiasis in the ED includes the screening and diagnosis of concomitant UTIs. However, correct interpretation of UA studies is vital to the correct implementation of antibiotic therapy. This study suggests that 1/3 of patients were undertreated and 21.8% were over-treated.

Comprehensive proteomic characterization of stem cell-derived extracellular matrices.

In the stem-cell niche, the extracellular matrix (ECM) serves as a structural support that additionally provides stem cells with signals that contribute to the regulation of stem-cell function, via reciprocal interactions between cells and components of the ECM. Recently, cell-derived ECMs have emerged as in vitro cell culture substrates to better recapitulate the native stem-cell microenvironment outside the body. Significant changes in cell number, morphology and function have been observed when mesenchymal stem cells (MSC) were cultured on ECM substrates as compared to standard tissue-culture polystyrene (TCPS). As select ECM components are known to regulate specific stem-cell functions, a robust characterization of cell-derived ECM proteomic composition is critical to better comprehend the role of the ECM in directing cellular processes. Here, we characterized and compared the protein composition of ECM produced in vitro by bone marrow-derived MSC, adipose-derived MSC and neonatal fibroblasts from different donors, employing quantitative proteomic methods. Each cell-derived ECM displayed a specific and unique matrisome signature, yet they all shared a common set of proteins. We evaluated the biological response of cells cultured on the different matrices and compared them to cells on standard TCPS. The matrices lead to differential survival and gene-expression profiles among the cell types and as compared to TCPS, indicating that the cell-derived ECMs influence each cell type in a different manner. This general approach to understanding the protein composition of different tissue-specific and cell-derived ECM will inform the rational design of defined systems and biomaterials that recapitulate critical ECM signals for stem-cell culture and tissue engineering.

Current practice of antibiotic utilization for renal colic in the emergency room.

INTRODUCTION: Urinalysis (UA) in the emergency setting for patients with nephrolithiasis produces potentially confusing results leading to treatment of presumed urinary tract infections (UTIs). Our objective was to evaluate the use of antibiotics in patients with nephrolithiasis in a large network of emergency departments (EDs). METHODS: A retrospective analysis of all ED visits associated with an ICD-9 diagnosis of nephrolithiasis and a CT scan between 2010 and 2013 was performed. Urinalysis data, the use of IV and PO antibiotics during the ED visit and at discharge were assessed. The presence of fever, elevated serum WBCs, >5 WBCs per hpf, and/or dip positive nitrites were used as appropriate criteria for antibiotic use. RESULTS: Urinalysis data were available for 3,518 (70%) of 5,035 patients with an ED diagnosis of nephrolithiasis and CT imaging. Of these visits, 237 patients had positive nitrites (6.7%) and 864 had >5 WBCs per hpf (24.6%) with 158 (4.5%) having both findings for a total of 943 patients. Intravenous antibiotics were given to 244 patients (25.9%) and oral antibiotics were given to 629 patients (66.7 %) with positive UA findings. Of the 2,440 patients with a negative UA and no leukocytosis or fever, 86 patients (3.5%) received IV antibiotics and 533 patients (21.8%) received PO antibiotics upon discharge. CONCLUSIONS: Proper treatment of nephrolithiasis in the ED includes the screening and diagnosis of concomitant UTIs. However, correct interpretation of UA studies is vital to the correct implementation of antibiotic therapy. This study suggests that 1/3 of patients were undertreated and 21.8% were over-treated.

Macrophage Galactose-Type Lectin-1 Deficiency Is Associated with Increased Neutrophilia and Hyperinflammation in Gram-Negative Pneumonia.

C-type lectin receptors (CLRs), the carbohydrate-recognizing molecules, orchestrate host immune response in homeostasis and in inflammation. In the present study we examined the function of macrophage galactose-type lectin-1 (MGL1), a mammalian CLR, in pneumonic sepsis, a deadly immune disorder frequently associated with a nonresolving hyperinflammation. In a murine model of pneumonic sepsis using pulmonary infection with Klebsiella pneumoniae, the expression of MGL1 was upregulated in the lungs of K. pneumoniae-infected mice, and the deficiency of this CLR in MGL1(-/-) mice resulted in significantly increased mortality to infection than in the MGL1-sufficient wild-type mice, despite a similar bacterial burden. The phagocytic cells from MGL1(-/-) mice did not exhibit any defects in bacterial uptake and intracellular killing and were fully competent in neutrophil extracellular trap formation, a recently identified extracellular killing modality of neutrophils. Instead, the increased susceptibility of MGL1(-/-) mice seemed to correlate with severe lung pathology, indicating that MGL1 is required for resolution of pulmonary inflammation. Indeed, the MGL1(-/-) mice exhibited a hyperinflammatory response, massive pulmonary neutrophilia, and an increase in neutrophil-associated immune mediators. Concomitantly, MGL1-deficient neutrophils exhibited an increased influx in pneumonic lungs of K. pneumoniae-infected mice. Taken together, these results show a previously undetermined role of MGL1 in controlling neutrophilia during pneumonic infection, thus playing an important role in resolution of inflammation. To our knowledge, this is the first study depicting a protective function of MGL1 in an acute pneumonic bacterial infection.

Atopic Dermatitis Is Associated With Cervical High Risk Human Papillomavirus Infection.

OBJECTIVE: High-risk human papillomavirus (hrHPV) infection is more likely to persist and cause cervical cancer in immunosuppressed women. Atopic dermatitis, which is known to affect cell-mediated immunity and skin barrier function, is associated with recalcitrant warts; therefore, we hypothesized that women with atopic dermatitis may be more likely to be positive for hrHPV infection and progress to high-grade cervical dysplasia. MATERIALS AND METHODS: A retrospective case-control study of 1,160 women who were either positive or negative for hrHPV in their index cervical cytology. Patient age, race, history of atopic dermatitis, allergic rhinitis, smoking, body mass index, socioeconomic status, marital status, hormone contraceptive use, and 2-year clinical outcomes (follow-up hrHPV testing and cervical biopsy results) were recorded. All cases with atopic dermatitis (n = 74) were confirmed by a dermatologist. Analyses were restricted to females with documented clinical follow-up, which yielded 577 hrHPV-positive and 583 hrHPV-negative cases for comparison. Associations were examined by t test, χ test, and multivariate logistic regression. RESULTS: Atopic dermatitis was more common in the hrHPV-positive cases (48/577, 8.3%) compared with HPV-negative controls (26/583, 4.5%, p = .007). Multivariate logistic regression analysis revealed an adjusted odds ratio of 3.75 (95% CI = 1.3-10.9, p = .02) after controlling for significant covariates, such as age and marital status. Smoking was not associated with hrHPV infection, persistence, or high-grade cervical dysplasia in these cases. CONCLUSIONS: Atopic dermatitis is associated with cervical hrHPV infection in adult women.

Fluid Bolus for Renal Colic: Current Practice.

INTRODUCTION: Historically the administration of intravenous fluid boluses in patients with urolithiasis and acute renal colic has been a standardized practice in the emergency department as a part of a conservative approach. In theory, an intravenous fluid bolus may promote ureteral fluid flow. However, randomized, controlled trials have shown no benefit of fluid boluses in this setting. We assessed current fluid bolus practices in community and tertiary care emergency departments. METHODS: We analyzed all emergency department visits in the Cleveland Clinic health care network with an ICD-9 diagnosis of 592.0 and computerized tomography of the abdomen/pelvis between December 7, 2010 and May 6, 2013. The incidence of intravenous fluid bolus administration was assessed, and patient demographics, serum laboratory values and urinalysis were collected. Cases with a blood urea nitrogen-to-creatinine ratio greater than 20 were considered hypovolemic and urine specific gravity values greater than 1.030 were considered suggestive of hypovolemia. RESULTS: Overall 60.2% (3,037 of 5,048) of patients with nephrolithiasis and computerized tomography received intravenous fluid boluses. The majority of patients who received a fluid bolus (79.12%) did not meet the criteria for volume depletion based on blood urea nitrogen-to-creatinine ratio or urine specific gravity. In addition, there was no statistically significant difference in the proportion of patients with a blood urea nitrogen-to-creatinine ratio greater than 20 among those who received fluid boluses (25.50%, 617 of 2,420) and those who did not (25.45%, 408 of 1,603; p=1.00). CONCLUSIONS: The use of forced fluids continues to be a common practice in emergency departments and they are frequently administered despite normal blood urea nitrogen-to-creatinine ratios. Thus, it is likely that fluids are not administered due to hypovolemia but rather due to practice approaches rooted in historical dogma and the lack of guidelines on this topic.

Non-cell-adhesive substrates for printing of arrayed biomaterials.

Cellular microarrays have become extremely useful in expediting the investigation of large libraries of (bio)materials for both in vitro and in vivo biomedical applications. An exceedingly simple strategy is developed for the fabrication of non-cell-adhesive substrates supporting the immobilization of diverse (bio)material features, including both monomeric and polymeric adhesion molecules (e.g., RGD and polylysine), hydrogels, and polymers.

Tri-layered elastomeric scaffolds for engineering heart valve leaflets.

Tissue engineered heart valves (TEHVs) that can grow and remodel have the potential to serve as permanent replacements of the current non-viable prosthetic valves particularly for pediatric patients. A major challenge in designing functional TEHVs is to mimic both structural and anisotropic mechanical characteristics of the native valve leaflets. To establish a more biomimetic model of TEHV, we fabricated tri-layered scaffolds by combining electrospinning and microfabrication techniques. These constructs were fabricated by assembling microfabricated poly(glycerol sebacate) (PGS) and fibrous PGS/poly(caprolactone) (PCL) electrospun sheets to develop elastic scaffolds with tunable anisotropic mechanical properties similar to the mechanical characteristics of the native heart valves. The engineered scaffolds supported the growth of valvular interstitial cells (VICs) and mesenchymal stem cells (MSCs) within the 3D structure and promoted the deposition of heart valve extracellular matrix (ECM). MSCs were also organized and aligned along the anisotropic axes of the engineered tri-layered scaffolds. In addition, the fabricated constructs opened and closed properly in an ex vivo model of porcine heart valve leaflet tissue replacement. The engineered tri-layered scaffolds have the potential for successful translation towards TEHV replacements.

Electrospun PGS:PCL microfibers align human valvular interstitial cells and provide tunable scaffold anisotropy.

Tissue engineered heart valves (TEHV) can be useful in the repair of congenital or acquired valvular diseases due to their potential for growth and remodeling. The development of biomimetic scaffolds is a major challenge in heart valve tissue engineering. One of the most important structural characteristics of mature heart valve leaflets is their intrinsic anisotropy, which is derived from the microstructure of aligned collagen fibers in the extracellular matrix (ECM). In the present study, a directional electrospinning technique is used to fabricate fibrous poly(glycerol sebacate):poly(caprolactone) (PGS:PCL) scaffolds containing aligned fibers, which resemble native heart valve leaflet ECM networks. In addition, the anisotropic mechanical characteristics of fabricated scaffolds are tuned by changing the ratio of PGS:PCL to mimic the native heart valve's mechanical properties. Primary human valvular interstitial cells (VICs) attach and align along the anisotropic axes of all PGS:PCL scaffolds with various mechanical properties. The cells are also biochemically active in producing heart-valve-associated collagen, vimentin, and smooth muscle actin as determined by gene expression. The fibrous PGS:PCL scaffolds seeded with human VICs mimick the structure and mechanical properties of native valve leaflet tissues and would potentially be suitable for the replacement of heart valves in diverse patient populations.

Biomimetic scaffold combined with electrical stimulation and growth factor promotes tissue engineered cardiac development.

Toward developing biologically sound models for the study of heart regeneration and disease, we cultured heart cells on a biodegradable, microfabricated poly(glycerol sebacate) (PGS) scaffold designed with micro-structural features and anisotropic mechanical properties to promote cardiac-like tissue architecture. Using this biomimetic system, we studied individual and combined effects of supplemental insulin-like growth factor-1 (IGF-1) and electrical stimulation (ES). On culture day 8, all tissue constructs could be paced and expressed the cardiac protein troponin-T. IGF-1 reduced apoptosis, promoted cell-to-cell connectivity, and lowered excitation threshold, an index of electrophysiological activity. ES promoted formation of tissue-like bundles oriented in parallel to the electrical field and a more than ten-fold increase in matrix metalloprotease-2 (MMP-2) gene expression. The combination of IGF-1 and ES increased 2D projection length, an index of overall contraction strength, and enhanced expression of the gap junction protein connexin-43 and sarcomere development. This culture environment, designed to combine cardiac-like scaffold architecture and biomechanics with molecular and biophysical signals, enabled functional assembly of engineered heart muscle from dissociated cells and could serve as a template for future studies on the hierarchy of various signaling domains relative to cardiac tissue development.