Ceftriaxone Pharmacokinetics and Pharmacodynamic Target Attainment for Three Pediatric Patients Receiving Continuous Kidney Replacement Therapy.

Ceftriaxone is used commonly for sepsis, including in children requiring continuous kidney replacement therapy (CKRT). No reports exist of pharmacokinetic (PK) parameters for children receiving ceftriaxone on CKRT. We enrolled children admitted to our pediatric intensive care unit (PICU) who received CKRT for >24 hours and received >1 dose of ceftriaxone while on and off CKRT. We measured free ceftriaxone -concentrations from residual blood samples then used Bayesian estimation with PK modeling software to generate concentration-time profiles and determine PK parameters and the percentage of time free ceftriaxone concentrations were above 1× or 4× MIC (% fT >MIC). Three patients aged 2 to 17 years were included; all were anuric at CKRT initiation and received 50 mg/kg (max 2000 mg) ceftriaxone every 12 to 24 hours. Total ceftriaxone clearance (CL) was 0.50 to 3.67 L/hr while receiving CKRT and 0.29 to 2.71 L/hr while off, indicating CKRT provided 25% to 42% of total ceftriaxone CL. All achieved 100% fT >1× and 4× MIC using an estimated MIC (1 mg/L) for patients 1 to 2 (no culture data) and a measured MIC (0.016 mg/L) for patient 3. Therefore, CKRT contributed significantly to total ceftriaxone clearance in 3 children though the dosing strategies used in each patient attained PD targets.

A Comparative Study of Responses to Retina Questions from Either Experts, Expert-Edited Large Language Models, or Expert-Edited Large Language Models Alone.

Objective: To assess the quality, empathy, and safety of expert edited large language model (LLM), human expert created, and LLM responses to common retina patient questions. Design: Randomized, masked multicenter study. Participants: Twenty-one common retina patient questions were randomly assigned among 13 retina specialists. Methods: Each expert created a response (Expert) and then edited a LLM (ChatGPT-4)-generated response to that question (Expert + artificial intelligence [AI]), timing themselves for both tasks. Five LLMs (ChatGPT-3.5, ChatGPT-4, Claude 2, Bing, and Bard) also generated responses to each question. The original question along with anonymized and randomized Expert + AI, Expert, and LLM responses were evaluated by the other experts who did not write an expert response to the question. Evaluators judged quality and empathy (very poor, poor, acceptable, good, or very good) along with safety metrics (incorrect information, likelihood to cause harm, extent of harm, and missing content). Main Outcome: Mean quality and empathy score, proportion of responses with incorrect information, likelihood to cause harm, extent of harm, and missing content for each response type. Results: There were 4008 total grades collected (2608 for quality and empathy; 1400 for safety metrics), with significant differences in both quality and empathy (P < 0.001, P < 0.001) between LLM, Expert and Expert + AI groups. For quality, Expert + AI (3.86 ± 0.85) performed the best overall while GPT-3.5 (3.75 ± 0.79) was the top performing LLM. For empathy, GPT-3.5 (3.75 ± 0.69) had the highest mean score followed by Expert + AI (3.73 ± 0.63). By mean score, Expert placed 4 out of 7 for quality and 6 out of 7 for empathy. For both quality (P < 0.001) and empathy (P < 0.001), expert-edited LLM responses performed better than expert-created responses. There were time savings for an expert-edited LLM response versus expert-created response (P = 0.02). ChatGPT-4 performed similar to Expert for inappropriate content (P = 0.35), missing content (P = 0.001), extent of possible harm (P = 0.356), and likelihood of possible harm (P = 0.129). Conclusions: In this randomized, masked, multicenter study, LLM responses were comparable with experts in terms of quality, empathy, and safety metrics, warranting further exploration of their potential benefits in clinical settings. Financial Disclosures: Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of the article.

Cystatin C Outperforms Creatinine in Predicting Cefepime Clearance in Pediatric Stem Cell Transplant Recipients.

Pediatric hematopoietic stem cell transplant (HSCT) patients are at risk of developing both sepsis and altered kidney function. Cefepime is used for empiric coverage post-HSCT and requires dose adjustment based on kidney function. Since cefepime's antimicrobial efficacy is determined by the time free concentrations exceed bacterial minimum inhibitory concentration (MIC), it is important to assess kidney function accurately to ensure adequate concentrations. Serum creatinine (SCr) is routinely used to estimate glomerular filtration rate (eGFR) but varies with muscle mass, which can be significantly lower in HSCT patients, making SCr an inaccurate kidney function biomarker. Cystatin C (CysC) eGFR is independent of muscle mass, though steroid use increases CysC. Objectives of this study were to describe how eGFR impacts cefepime pharmacokinetic/pharmacodynamic (PK/PD) target attainment in pediatric HSCT patients, to investigate which method of estimating GFR (SCr, CysC, combined) best predicts cefepime clearance, and to explore additional predictors of cefepime clearance. Patients admitted to the pediatric HSCT unit who received ≥2 cefepime doses were prospectively enrolled. We measured total cefepime peak/trough concentrations between the second and fourth cefepime doses and measured SCr and CysC if not already obtained clinically within 24h of cefepime samples. eGFRs were calculated with Chronic Kidney Disease in Children U25 equations. Bayesian estimates of cefepime clearance were determined with a pediatric cefepime PK model and PK software MwPharm++. Simple linear regression was used to compare cefepime clearance normalized to body surface area (BSA) to BSA-normalized SCr-, CysC-, and SCr-/CysC-eGFRs, while multiple linear regression was used to account for additional predictors of cefepime clearance. For target attainment, we assessed the percentage of time free cefepime concentrations exceeded 1x MIC (%fT>1x MIC) and 4x MIC (%fT>4x MIC) using a susceptibility breakpoint of 8 mg/L for Pseudomonas aeruginosa. We enrolled 53 patients (ages 1 to 30 years, median 8.9 years). SCr- and CysC-eGFRs were lower in patients who attained 100% fT>1xMIC compared to those who did not attain this target: 115 versus 156 mL/min/1.73m2 (p = .01) for SCr-eGFR and 73.5 versus 107 mL/min/1.73m2 (p < .001) for CysC-eGFR. SCr-eGFR was weakly positively correlated with cefepime clearance (adjusted [a]r2= 0.14), while CysC-eGFR and SCr-/CysC-eGFR had stronger positive correlations (ar2 = 0.30 CysC, ar2 = 0.28 combo. There was a weak, significant linear association between increasing CysC-eGFR and decreased %fT>1xMIC (ar2 = 0.32) and %fT>4xMIC (ar2 = 0.14). No patients with a CysC-eGFR >120 mL/min/1.73 m2 achieved 100% fT>1xMIC or 50% fT>4x MIC. In multiple regression models, underlying diagnosis of hemoglobinopathy (in all models) and being pretransplant (in SCr and combined models) were associated with increased cefepime clearance, while concomitant use of calcineurin inhibitors was associated with decreased cefepime clearance in all models. Overall, the combo-eGFR model with timing pretransplant, hemoglobinopathy, and use of calcineurin inhibitors had the best performance (ar2 = 0.63). CysC-based eGFRs (CysC alone and combined) predicted cefepime clearance better than SCr-eGFR, even after considering steroid use. Increasing CysC eGFR correlated with decreased probability of PD target attainment, raising concerns for underdosing at high eGFRs. CysC should be included when estimating kidney function to provide adequate dosing of cefepime in pediatric HSCT patients.

Trends in the Clinical Presentation of Uveal Melanoma During the COVID-19 Pandemic.

BACKGROUND AND OBJECTIVE: The objective was to evaluate factors associated with clinical presentation of uveal melanoma (UM) during the initial two years of the coronavirus disease 2019 pandemic. PATIENTS AND METHODS: This was a multi-site, retrospective cohort study of patients treated for uveal melanoma during the first (early) and second (late) year of the pandemic compared with the year prior (control). RESULTS: A total of 48, 67, and 75 patients were in the control, early, and late cohorts, respectively. The early cohort had a higher frequency of large tumors (control: 29.2%, early: 40.3%, late: 29.3%; P < 0.001) at presentation. Both the early and late cohorts had higher rates of enucleation (control: 8.33%, early: 20.9%, late: 18.67%; P ≤ 0.0338) compared to the control cohort. CONCLUSIONS: While there was an increase in large tumors along with a rise in enucleation during the first year of the pandemic, enucleation rates remained elevated even while tumor sizes normalized. [Ophthalmic Surg Lasers Imaging Retina 2024;55:278-284.].

Proteomic analysis of decellularized mice liver and kidney extracellular matrices.

BACKGROUND: The extracellular matrix (ECM) is a three-dimensional network of proteins that encases and supports cells within a tissue and promotes physiological and pathological cellular differentiation and functionality. Understanding the complex composition of the ECM is essential to decrypt physiological processes as well as pathogenesis. In this context, the method of decellularization is a useful technique to eliminate cellular components from tissues while preserving the majority of the structural and functional integrity of the ECM. RESULTS: In this study, we employed a bottom-up proteomic approach to elucidate the intricate network of proteins in the decellularized extracellular matrices of murine liver and kidney tissues. This approach involved the use of a novel, perfusion-based decellularization protocol to generate acellular whole organ scaffolds. Proteomic analysis of decellularized mice liver and kidney ECM scaffolds revealed tissue-specific differences in matrisome composition, while we found a predominantly stable composition of the core matrisome, consisting of collagens, glycoproteins, and proteoglycans. Liver matrisome analysis revealed unique proteins such as collagen type VI alpha-6, fibrillin-2 or biglycan. In the kidney, specific ECM-regulators such as cathepsin z were detected. CONCLUSION: The identification of distinct proteomic signatures provides insights into how different matrisome compositions might influence the biological properties of distinct tissues. This experimental workflow will help to further elucidate the proteomic landscape of decellularized extracellular matrix scaffolds of mice in order to decipher complex cell-matrix interactions and their contribution to a tissue-specific microenvironment.

BILATERAL EYE PATCHING MAY IMPROVE CLINICAL OUTCOMES FOR ACUTE PRIMARY RHEGMATOGENOUS RETINAL DETACHMENT.

PURPOSE: Evaluate preoperative bilateral eye patching (BEP) on subretinal fluid and vision in acute primary rhegmatogenous retinal detachments (RRDs). METHODS: Retrospective nonrandomized interventional study of 335 patients with RRD undergoing BEP until surgery (BEP cohort) and separated by the percentage of full-time compliance: high (≥90%), medium (>90% but ≥50%), and low (<50%). Those declining BEP were included (control). All underwent surgery and were followed for ≥3 months. Imaging was obtained immediately before surgery. Best-corrected visual acuity was measured at the longest follow-up and immediately before surgery. SRF and foveal status immediately before surgery were analyzed. RESULTS: Two hundred and forty and 95 patients were in BEP and control cohorts, respectively. Thirty patients presented immediately before surgery for analysis. High (64%) and medium (35%) compliance showed significantly greater ( P < 0.01) SRF reduction compared with low (4%) and control (3%). Mac-off RRD showed significantly greater ( P < 0.01) foveal reattachment with high (29%) and medium (8%) compliance compared with low (2%) and control (1%). Mac-on RRD demonstrated no significant differences ( P ≥ 0.51) in final best-corrected visual acuity among high (0 logarithm of the minimum angle of resolution [logMAR] [median], 20/20 Snellen), medium (0.10 logMAR, 20/25 Snellen), low (0.10 logMAR), and control cohorts (0.10 logMAR). Mac-off RRD demonstrated significantly better final best-corrected visual acuity with high compliance (0.30 logMAR, 20/40 Snellen) compared with low (0.40 logMAR, 20/50 Snellen; P = 0.04) and control (0.60 logMAR, 20/80 Snellen; P = 0.02). CONCLUSION: Preoperative BEP can stabilize or improve subretinal fluid in acute primary RRD. Patients with BEP >50% of the time experienced the greatest benefits.

PROPHYLACTIC TREATMENT OF LATTICE DEGENERATION IN FELLOW EYES AFTER REPAIR OF UNCOMPLICATED PRIMARY RHEGMATOGENOUS RETINAL DETACHMENT.

PURPOSE: To evaluate prophylactic treatment (PTx) of lattice degeneration (LD) on retinal tear (RT) and rhegmatogenous retinal detachment (RRD) risk in fellow eyes of patients after primary RRD repair in the first eye. METHODS: This was a consecutive case series with cohort control involving patients with RRD repair from January 1, 2013, through December 31, 2017. Patients received PTx (PTx cohort) or no PTx (No-PTx cohort) in fellow eye with 5-year follow-up. Primary outcome measure was proportion with new fellow eye RT/RRD. Secondary outcomes included logarithm of minimum angle of resolution (logMAR) best-corrected visual acuity (BCVA) and status of myopia, posterior vitreous detachment, and pseudophakia. RESULTS: Four hundred ninety-eight patients were divided into 146 and 352 in PTx and No-PTx cohorts, respectively. PTx cohort developed significantly ( P < 0.05) fewer RT/RRD (17%) than No-PTx cohort (41%). PTx significantly ( P < 0.05) lowered RT/RRD irrespective of posterior vitreous detachment and myopia status. PTx patients undergoing phacoemulsification demonstrated significantly ( P < 0.05) less RT/RRD (22%) than No-PTx cohort (31%). There was no significant ( P = 0.96) final BCVA difference between PTx (median = 0 logMAR) and No-PTx (median = 0 logMAR) cohorts. CONCLUSION: PTx of asymptomatic fellow eye LD reduced RT/RRD risk.

Piperacillin pharmacokinetics and pharmacodynamics in paediatric patients who received high frequency intra-operative piperacillin/tazobactam dosing.

Piperacillin/tazobactam (PTZ) is a broad-spectrum antibiotic, typically dosed every six hours (q6h). Guidelines recommend dosing PTZ every 2 hours (q2h) intra-operatively for complex abdominal surgery, including liver transplant. The data supporting the guidelines for intra-operative dosing are sparse and the pharmacokinetics/pharmacodynamics (PK/PD) of q2h dosing has not been studied by simulation or in humans. In this study, PK/PD parameters of high-frequency intra-operative dosing and q6h post-operative dosing were compared in critically ill children. Paediatric patients who received PTZ during complex abdominal surgery or transplant and who had intra-operative and post-operative opportunistic samples were included. Using a published PK model and observed concentrations, individual piperacillin PK/PD parameters were estimated using Bayesian estimation. Alternative post-operative dosing strategies were simulated using the patients with the highest and lowest estimated piperacillin clearance. Thirteen patients were included (median age: 3.1 years, 85% liver transplant recipients). PK parameters in the intra-operative and post-operative phases were not significantly different (clearance: 15.8 ± 7.2 vs. 12.6 ± 6.3 L/h/70 kg, P=0.070; central volume: 13.4 [13.1, 13.8] vs. 15.2 [12.2, 16.0] L/70 kg, P=0.22). At an individual level, intra-operative clearance values were -35% to 139% of the post-operative values, whereas central volume intra-operative values were -40% to 77% of the post-operative values. Intra-operative piperacillin exposure was higher during high-frequency dosing compared with the post-operative period (AUC/h: 109 [93.4, 127] vs. 62.8 [41.6, 78.3] mg/L, P=0.002). Simulations showed great variation in optimal dosing strategies that would minimise toxicity and maximise efficacy, indicating a role for individualised dosing in paediatric surgical populations.

CHOROIDAL NEVUS ASSOCIATED WITH VITELLIFORM DEPOSITION IN A PATIENT WITH AUTOSOMAL DOMINANT BEST DYSTROPHY.

BACKGROUND/PURPOSE: To describe the clinical, optical coherence tomography (OCT), fundus autofluorescence and ultrasound findings of a patient with a choroidal nevus actively exuding vitelliform material in the setting of autosomal dominant Best dystrophy (BD). METHODS: The patient's clinical course was followed over time with ophthalmic examinations and multimodal imaging. RESULTS: A 71-year-old male patient with BD was referred for evaluation of a choroidal nevus in the right eye. Dilated fundoscopic examination showed a small pigmented choroidal nevus in the temporal periphery. Over a 3-year period, the nevus developed progressive deposition of vitelliform material along its inferior border. Meanwhile, OCT and fundus photography showed only slight growth. Ultrasound showed no change in height; basal measurements were confounded by the increased vitelliform deposits. Genetic testing confirmed a heterozygous mutation in the BEST1 gene and electrophysiology was consistent with BD. CONCLUSIONS: Dysfunction of the retinal pigment epithelium associated with BD may cause novel presentations of other conditions such as choroidal nevi. The implication for malignant transformation of a choroidal nevus associated with vitelliform deposit accumulation in this context is unknown.

Papain-Based Solubilization of Decellularized Extracellular Matrix for the Preparation of Bioactive, Thermosensitive Pregels.

Solubilized, gel-forming decellularized extracellular matrix (dECM) is used in a wide range of basic and translational research and due to its inherent bioactivity can promote structural and functional tissue remodeling. The animal-derived protease pepsin has become the standard proteolytic enzyme for the solubilization of almost all types of collagen-based dECM. In this study, pepsin was compared with papain, α-amylase, and collagenase for their potential to solubilize porcine liver dECM. Maximum preservation of bioactive components and native dECM properties was used as a decisive criterion for further application of the enzymes, with emphasis on minimal destruction of the protein structure and maintained capacity for physical thermogelation at neutral pH. The solubilized dECM digests, and/or their physically gelled hydrogels were characterized for their rheological properties, gelation kinetics, GAG content, proteomic composition, and growth factor profile. This study highlights papain as a plant-derived enzyme that can serve as a cost-effective alternative to animal-derived pepsin for the efficient solubilization of dECM. The resulting homogeneous papain-digested dECM preserved its thermally triggered gelation properties similar to pepsin digests, and the corresponding dECM hydrogels demonstrated their enhanced bioadhesiveness in single-cell force spectroscopy experiments with fibroblasts. The viability and proliferation of human HepaRG cells on dECM gels were similar to those on pure rat tail collagen type I gels. Papain is not only highly effective and economically attractive for dECM solubilization but also particularly interesting when digesting human-tissue-derived dECM for regenerative applications, where animal-derived materials are to be avoided.

Liquid-biopsy proteomics combined with AI identifies cellular drivers of eye aging and disease in vivo.

Single-cell analysis in living humans is essential for understanding disease mechanisms, but it is impractical in non-regenerative organs, such as the eye and brain, because tissue biopsies would cause serious damage. We resolve this problem by integrating proteomics of liquid biopsies with single-cell transcriptomics from all known ocular cell types to trace the cellular origin of 5,953 proteins detected in the aqueous humor. We identified hundreds of cell-specific protein markers, including for individual retinal cell types. Surprisingly, our results reveal that retinal degeneration occurs in Parkinson's disease, and the cells driving diabetic retinopathy switch with disease stage. Finally, we developed artificial intelligence (AI) models to assess individual cellular aging and found that many eye diseases not associated with chronological age undergo accelerated molecular aging of disease-specific cell types. Our approach, which can be applied to other organ systems, has the potential to transform molecular diagnostics and prognostics while uncovering new cellular disease and aging mechanisms.

Biobanking of Human Aqueous and Vitreous Liquid Biopsies for Molecular Analyses.

A critical challenge in translational research is establishing a viable and efficient interface between patient care in the operating room (OR) and the research laboratory. Here, we developed a protocol for acquiring high-quality liquid biopsies for molecular analyses from the aqueous humor and the vitreous from patients undergoing eye surgery. In this workflow, a Mobile Operating Room Lab Interface (MORLI) cart equipped with a computer, a barcode scanner, and lab instruments, including onboard cold storage, is used to obtain and archive human biological samples. A web-based data privacy-compliant database enables annotating each sample over its lifetime, and a cartesian coordinate system allows tracking each barcoded specimen in storage, enabling quick and accurate retrieval of samples for downstream analyses. Molecular characterization of human tissue samples not only serves as a diagnostic tool (e.g., to distinguish between infectious endophthalmitis and other non-infectious intraocular inflammation) but also represents an important component of translational research, allowing the identification of new drug targets, development of new diagnostic tools, and personalized therapeutics.

Ceftriaxone Pharmacokinetics and Pharmacodynamics in 2 Pediatric Patients on Extracorporeal Membrane Oxygenation Therapy.

BACKGROUND: Critically ill patients with cardiac or respiratory failure may require extracorporeal membrane oxygenation (ECMO). Antibiotics are frequently administered when the suspected cause of organ failure is an infection. Ceftriaxone, a ß-lactam antibiotic, is commonly used in patients who are critically ill. Although studies in adults on ECMO have suggested minimal impact on ceftriaxone pharmacokinetics, limited research exists on ceftriaxone pharmacokinetics/pharmacodynamics (PK/PD) in pediatric ECMO patients. We report the PK profiles and target attainment of 2 pediatric patients on ECMO who received ceftriaxone. METHODS: Ceftriaxone concentrations were measured in 2 pediatric patients on ECMO using scavenged opportunistic sampling. PK profiles were generated and individual PK parameters were estimated using measured free ceftriaxone concentrations and a published population PK model in children who are critically ill, using Bayesian estimation. RESULTS: Patient 1, an 11-year-old boy on venovenous ECMO for respiratory failure received 2 doses of 52 mg/kg ceftriaxone 12 hours apart while on ECMO and additional doses every 12 hours off ECMO. On ECMO, ceftriaxone clearance was 13.0 L/h/70 kg compared with 7.6 L/h/70 kg off ECMO, whereas the model-predicted mean clearance in children who are critically ill without ECMO support was 6.54 L/h/70 kg. Patient 2, a 2-year-old boy on venoarterial ECMO due to cardiac arrest received 50 mg/kg ceftriaxone every 12 hours while on ECMO for >7 days. Only clearance while on ECMO could be estimated (9.1 L/h/70 kg). Trough concentrations in both patients were >1 mg/L (the breakpoint for Streptococcus pneumoniae ) while on ECMO. CONCLUSIONS: ECMO increased ceftriaxone clearance above the model-predicted clearances in the 2 pediatric patients studied. Twelve-hour dosing allowed concentrations to remain above the breakpoint for commonly targeted bacteria but not 4 times the breakpoint in one patient, suggesting that precision dosing may be beneficial to ensure target attainment in children on ECMO.

Multimodal Retinal Imaging Findings in Hardikar Syndrome.

PURPOSE: To describe the syndromic, clinical, and retinal findings of a patient with an extremely-rare genetic condition known as Hardikar Syndrome (HS) with presentation of optical coherence tomography (OCT), fundus autofluorescence (FAF), fluorescein angiographic (FA), and indocyanine green angiographic (ICG) findings. METHODS: Clinical course was detailed and followed over time with examinations and multimodal imaging. PATIENT AND RESULTS: A 17-year-old patient with HS was referred for possible retinitis pigmentosa. Dilated fundoscopic examination revealed large, multifocal cauliform patches of chorioretinal retinal pigment epithelium (RPE) changes with RPE drop-out involving the macula and periphery in both eyes. Additionally, an inactive choroidal neovascular membrane (CNVM) was present in the left eye. Multimodal imaging with OCT, FAF, FA and ICG correlated with the clinical findings of focal patches of chorioretinal degeneration in both eyes. Additionally, an anomalous finding of the superior retinal arterial vessels filling in tandem with the choroidal was present in the left eye. The patient's clinical findings were consistent with HS, and genetic testing with whole exome sequencing revealed a pathogenic mutation in the MED12 gene, confirming diagnosis. DISCUSSION AND CONCLUSIONS: HS is associated with RPE degeneration, creating focal patches of pigmentary chorioretinal atrophic lesions. Vision loss can occur due to the development of CNVMs. We recommend close evaluation and follow-up for HS patients with multimodal retinal imaging.

Toward a 3D Printed Perfusable Islet Embedding Structure: Technical Notes and Preliminary Results.

To date, islet transplantation to treat type 1 diabetes mellitus remains unsuccessful in long-term follow-up, mainly due to failed engraftment and reconstruction of the islet niche. Alternative approaches, such as islet embedding structures (IESs) based on 3D printing have been developed. However, most of them have been implanted subcutaneously and only a few are intended for direct integration into the vascular system through anastomosis. In this study, we 3D printed a proof-of-concept IES using gelatin methacrylate biocompatible ink. This structure consisted of a branched vascular system surrounding both sides of a central cavity dedicated to islets of Langerhans. Furthermore, we designed a bioreactor optimized for these biological structures. This bioreactor allows seeding and perfusion experiments under sterile and physiological conditions. Preliminary experiments aimed to analyze if the vascular channel could successfully be seeded with mature endothelial cells and the central cavity with rat islets. Subsequently, the structures were used for a humanized model seeding human endothelial progenitor cells (huEPC) within the vascular architecture and human islets co-cultured with huEPC within the central cavity. The constructs were tested for hemocompatibility, suture strength, and anastomosability. The 3D printed IES appeared to be hemocompatible and anastomosable using an alternative cuff anastomosis in a simple ex vivo perfusion model. While rat islets alone could not successfully be embedded within the 3D printed structure for 3 days, human islets co-cultivated with huEPC successfully engrafted within the same time. This result emphasizes the importance of co-culture, nursing cells, and islet niche. In conclusion, we constructed a proof-of-concept 3D printed islet embedding device consisting of a vascular channel that is hemocompatible and perspectively anastomosable to clinical scale blood vessels. However, there are numerous limitations in this model that need to be overcome to transfer this technology to the bedside.

Cefepime pharmacokinetics in critically ill children and young adults undergoing continuous kidney replacement therapy.

OBJECTIVES: Cefepime is an antibiotic commonly used to treat sepsis and is cleared by renal excretion. Cefepime dosing requires adjustment in patients with decreased kidney function and in those receiving continuous kidney replacement therapy (CKRT). We aimed to characterize cefepime PK in a diverse cohort of critically ill paediatric patients on CKRT. METHODS: Patients were identified from an ongoing pharmacokinetic/pharmacodynamic (PK/PD) study of beta-lactam antibiotics, and were included if they had received at least two cefepime doses in the ICU and were on CKRT for at least 24 h. PK parameters were estimated using MwPharm++ with Bayesian estimation and a paediatric population PK model. Target attainment was assessed as time of free cefepime concentrations above minimum inhibitory concentration (fT > 1× or 4 × MIC). RESULTS: Seven patients were included in the study (ages 2 to 20 years). CKRT indications included liver failure (n = 1), renal failure (n = 4) and fluid overload (n = 2). Total effluent flow rates ranged from 1833 to 3115 (mean 2603) mL/1.73 m2/h, while clearance was 2.11-3.70 (mean 3.0) L/h/70 kg. Effluent flows were lower, but clearance and fT > MIC were similar to paediatric data published previously. Using Pseudomonas aeruginosa MIC breakpoints, all patients had 100% of dosing interval above MIC, but only one had 100% of dosing interval above 4× MIC. CONCLUSIONS: Since most patients failed to attain stringent targets of 100% fT > 4×  MIC, model-informed precision dosing may benefit such patients.

Spontaneous Improvement of Myopic Retinoschisis Following a Long-term Observational Period: A Case Series.

PURPOSE: To highlight spontaneous resolution or improvement of myopic retinoschisis (MR) in actively surveilled patients. METHODS: Case series of five patients diagnosed with MR who did not undergo pars-plana vitrectomy and were carefully monitored by a single retina specialist. Ocular and medical history were reviewed, and clinical characteristics including visual acuity, and the status of the MR were monitored with spectral domain ocular coherence tomography (SD-OCT) at each clinic visit. RESULTS: Five patients with were identified to have MR without vitreomacular traction, or macular hole formation. Two patients exhibited spontaneous and complete resolution of MR without surgical intervention over an average observation time of 52.5 months. In these cases, a clinical posterior vitreous detachment (PVD) was documented preceding the resolution of MR over an average time of 26.5 months. Snellen best corrected visual acuity (BCVA) in these patients were improved (Case 1 from 20/50 to 20/40, Case 2 from 20/30 to 20/25). The remaining three patients were monitored for an average of 52 months and showed improvement of MR via OCT imaging. Snellen BCVA either remained stable or improved from baseline (Case 3 stable at 20/30, Case 4 improved from 20/40 to 20/30, and Case 5 stable at 20/20). CONCLUSION: These findings suggest that conservative management of MR with observation can be considered especially in patients with challenging co-morbidities (such as monocular status), and with a clinically identified posterior vitreous detachment without vitreomacular traction.

Clinical Factors and Outcomes of Acute-Onset Endophthalmitis Following Small-Gauge Pars Plana Vitrectomy Surgery.

BACKGROUND AND OBJECTIVES: Describe risk factors, findings, and outcomes of acute endophthalmitis (AE) following small-gauge pars plana vitrectomy (PPV). PATIENTS AND METHODS: This was a retrospective single-center, nonrandomized study of post-PPV AE patients from 2013 to 2021. All received vitreous biopsy before treatment. Patients were divided into cohorts: 1) PPV within 3 days of diagnosis (Urgent-PPV), and 2) no urgent PPV (Other-treatment [Tx]). Main outcome was best-corrected visual acuity (BCVA) at 6 months. RESULTS: Twenty-one patients were analyzed. Epiretinal membrane was the most common indication for PPV (48%). Incidence was 0.074%. Culture-positive rate was 57%. For final BCVA, there was no significant (P = 0.85) difference between Urgent-PPV (median = 0.40 logMAR) and Other Tx cohorts (median = 0.35 logMAR). Sclerotomy wounds were not sutured in 71% of patients. Approximately 24% and 38% of patients analyzed had either no tamponade or partial tamponade, respectively. CONCLUSION: Tamponade agents and sclerotomy suturing may be important factors when evaluating post-small-gauge PPV-associated AE. Further studies are necessary for clarification. [Ophthalmic Surg Lasers Imaging Retina 2023;54:395-400.].

Development and systematic evaluation of decellularization protocols in different application models for diaphragmatic tissue engineering.

BACKGROUND: Tissue engineered bioscaffolds based on decellularized composites have gained increasing interest for treatment of various diaphragmatic impairments, including muscular atrophies and diaphragmatic hernias. Detergent-enzymatic treatment (DET) constitutes a standard strategy for diaphragmatic decellularization. However, there is scarce data on comparing DET protocols with different substances in distinct application models in their ability to maximize cellular removal while minimizing extracellular matrix (ECM) damage. METHODS: We decellularized diaphragms of male Sprague Dawley rats with 1 % or 0.1 % sodium dodecyl sulfate (SDS) and 4 % sodium deoxycholate (SDC) by orbital shaking (OS) or retrograde perfusion (RP) through the vena cava. We evaluated decellularized diaphragmatic samples by (1) quantitative analysis including DNA quantification and biomechanical testing, (2) qualitative and semiquantitative analysis by proteomics, as well as (3) qualitative assessment with macroscopic and microscopic evaluation by histological staining, immunohistochemistry and scanning electron microscopy. RESULTS: All protocols produced decellularized matrices with micro- and ultramorphologically intact architecture and adequate biomechanical performance with gradual differences. The proteomic profile of decellularized matrices contained a broad range of primal core and ECM-associated proteins similar to native muscle. While no outstanding preference for one singular protocol was determinable, SDS-treated samples showed slightly beneficial properties in comparison to SDC-processed counterparts. Both application modalities proved suitable for DET. CONCLUSION: DET with SDS or SDC via orbital shaking or retrograde perfusion constitute suitable methods to produce adequately decellularized matrices with characteristically preserved proteomic composition. Exposing compositional and functional specifics of variously treated grafts may enable establishing an ideal processing strategy to sustain valuable tissue characteristics and optimize consecutive recellularization. This aims to design an optimal bioscaffold for future transplantation in quantitative and qualitative diaphragmatic defects.