Anatomy education in US Medical Schools: before, during, and beyond COVID-19.

BACKGROUND: Anatomy education in US medical schools has seen numerous changes since the call for medical education reform in 2010. The purpose of this study was to survey US medical schools to assess recent trends in anatomy education, the impact of the COVID-19 pandemic on anatomy teaching, and future directions of medical school anatomy curricula. METHODS: We sent a 29-item survey to anatomy course directors of 145 AAMC-associated allopathic medical schools inquiring about their schools' anatomy curricula. The survey contained objective discrete questions concerning the curricula changes preceding COVID-19 and those directly related to COVID-19. We also asked subjective and open-ended questions about the impact of COVID-19 and future directions of anatomy education. RESULTS: A total of 117/143 course directors (82%) completed the survey. Most schools (60%) reported a major change to their anatomy course within the past five years, including a decrease in total course time (20%), integration of anatomy into other courses (19%), and implementation of a "flipped classroom" (15%) teaching style. Due to COVID-19, there was a decrease in the fraction of course time dedicated to "hands-on" learning (p < 0.01) and teaching of clinical correlates (p = 0.02) and radiology (p < 0.01). Most course directors (79%) reported that COVID-19 had a negative impact on quality of learning due to decreased interactive or in-person (62%) learning and lack of dissection (44%). Incorporation of virtual-reality applications or 3D anatomy software (23%) and a decrease in cadaver dissection (13%) were the most common future anticipated changes. CONCLUSION: The constraints conferred by COVID-19 highlight the importance of maximizing interactive learning in the discipline of anatomy. In an era of social distancing and decreased emphasis on conventional anatomy dissection, adaptations of new technologies and teaching modalities may allow for traditional educational rigor to be sustained.

A double-click approach to the protecting group free synthesis of glycoconjugates.

The use of a bi-functional linker, containing an alkyne and an alkene, allows the protecting group free conjugation of reducing sugars to thiols via a double click process. Firstly the linker is attached to the sugar via one-pot glycosyl azide formation and Cu-catalysed azide-alkyne cycloaddition. Photochemical thiol-ene click reaction then allows conjugation to a range of thiols, including cysteine residues of peptides.

Protecting group free synthesis of glycosyl thiols from reducing sugars in water; application to the production of N-glycan glycoconjugates.

Glycosyl thiols may be accessed from the corresponding reducing sugars in water without recourse to any sugar projecting groups by way of a DMC mediated reaction with thioacetic acid in the presence of base, and hydrolysis of the anomeric thioacetate. Glycosyl thiols produced by this method may be used to access glycoconjugates, such as glycopeptides by use of the thiol-ene click reaction.

Worldwide variation of dialysis-associated peritonitis in children.

Peritonitis is the most common cause of dialysis failure in children on chronic peritoneal dialysis. We performed a prospective study of 501 peritonitis episodes in 44 pediatric dialysis centers located in 14 countries that examined peritonitis etiology, efficiency of opinion-based management guidelines, and final outcomes. Culture-negative incidence varied significantly from 11% in North America to 67% in Mexico. Argentina and North America had the highest rate of Gram-negative episodes. Pseudomonas-based peritonitis was eightfold more common in the United States than in Europe, and correlated with the frequency of exit site cleansing and topical mupirocin administration. Significant regional variation in antibiotic susceptibility was noted for the first generation cephalosporins and aminoglycosides. Initial response rates to standardized empiric antibiotic treatment did not differ between regions; however, final outcomes were significantly less favorable in Eastern Europe. The wide regional variation in culture-negative peritonitis, and the distribution and antibiotic susceptibilities of causative bacteria needs to be taken into consideration when the guidelines for empiric therapy of pediatric dialysis-associated peritonitis are revised.

The effect of vascular access location and size on circuit survival in pediatric continuous renal replacement therapy: a report from the PPCRRT registry.

PURPOSE: Well-functioning vascular access is essential for the provision of adequate CRRT. However, few data exist to describe the effect of catheter size or location on CRRT performance in the pediatric population. METHODS: Data for vascular access site, size, and location, as well as type of anticoagulant used and patient demographic data were gathered from the ppCRRT registry. Kaplan-Meier curves were generated and then analyzed by log-rank test or Cox Proportional Hazards model. RESULTS: Access diameter was found to significantly affect circuit survival. None of the 5 French catheters lasted longer than 20 hours. Seven and 9 French, but not 8 French, catheters fared worse than larger diameter catheters (p=0.002). Circuits associated with internal jugular access survived longer than subclavian or femoral access associated circuits (p<0.05). Circuit survival was also found to be favorably associated with the CVVHD modality (p<0.001). CONCLUSIONS: Functional CRRT circuit survival in children is favored by larger catheter diameter, internal jugular vein insertion site and CVVHD. For patients requiring catheter diameters less than 10 French, CRRT circuit survival might be optimized if internal jugular vein insertion is feasible. Conversely, when a vascular access site other than the internal jugular vein is most prudent, consideration should be given to using the largest diameter catheter appropriate for the size of the child. The CVVHD modality was associated with longer circuit survival, but the mechanism by which this occurs is unclear.

Hemofiltration for cytokine-driven illnesses: the mediator delivery hypothesis.

Hemofiltration is evolving as an adjunctive therapy for sepsis and other forms of systemic inflammation. Designed as a substitute for lost renal function, it is sometimes employed prior to the onset of renal failure to facilitate the nonspecific clearance of pro-inflammatory mediators. Prevailing theories suggest that hemofiltration attenuates the immune response when a threshold amount of excess cytokine is removed at the semi-permeable membrane. In this article we introduce an alternative hypothesis, in which hemofiltration exerts its effect by reinvigorating lymphatic flow and function. Crystalloid "replacement" solution, as much as 48 to 72 liters daily, is infused to restore intravascular volume lost through production of ultrafiltrate. Partial redistribution into interstitium and lymph mobilizes inflammatory mediators and other proteins, cellular byproducts, excessive ground matrix, fragments of apoptotic cells and free DNA. These substances are then metabolized, scavenged or cleared at multiple sites, including the reticuloendothelial system, liver, kidney, erythrocyte, and hemofilter.

The Prospective Pediatric Continuous Renal Replacement Therapy (ppCRRT) Registry: design, development and data assessed.

Many issues plague the pediatric ARF outcome literature, which include data only from single center sources, a relative lack of prospective study, mixture within studies of renal replacement therapy modality without stratification and inconsistent use of methods to control for patient illness severity in outcome analysis. Since January 2001, the Prospective Pediatric CRRT (ppCRRT) Registry Group has been collecting data from multiple United States pediatric centers to obtain demographic data regarding pediatric patients who receive CRRT, assess the effect of different CRRT prescriptions on circuit function and evaluate the impact of clinical variables on patient outcome. The aim of the current paper is to describe the ppCRRT Registry design, review the decision process and rationale for the options chosen for the ppCRRT format and discuss the analysis plan and future projects envisioned for the ppCRRT Registry.

Radiology goes filmless.

PROBLEM: Long turnaround time for radiology reports, unacceptable percentage of misplaced films. SOLUTION: Installation of hospitalwide PACS, implementation of voice recognition dictation system, upgrade of RIS. RESULTS: Rapid and significant improvement in reporting times, virtual elimination of misplaced films, integration of radiology services throughout the enterprise. KEYS TO SUCCESS: Detailed financial model and needs assessment, commitment by management and staff, well-planned implementation, choice of vendor that provides total solution and support.

Recurrence of hemolytic uremic syndrome after renal transplantation in children: a report of the North American Pediatric Renal Transplant Cooperative Study.

BACKGROUND: Hemolytic uremic syndrome (HUS) is the cause of renal failure in 2-4% of children on dialysis. After renal transplantation, HUS can recur, but recurrence rate and risk factors are controversial. METHODS: We reviewed the recurrence of HUS within the North American Pediatric Renal Transplant Cooperative Study (NAPRTCS) registry and used a separate questionnaire to ascertain additional clinical information. RESULTS: Of 68 renal allografts, HUS recurred in 6 allografts (8.8%) occurring in five patients (8.2%). Four patients had atypical HUS, whereas one patient had classic HUS. HUS recurred after transplantation in 33 days or less in all but one allograft. Outcome was poor with five of six allografts lost, despite treatment with fresh-frozen plasma or plasmapheresis. Cyclosporine had no effect on outcome or HUS recurrence. CONCLUSIONS: The risk of HUS recurrence in the allograft is 8-9% and is heightened in atypical HUS. Treatment was not effective and graft outcome was poor. Cyclosporine does not affect HUS recurrence.

The clinical efficacy of higher hematocrit levels in children with chronic renal insufficiency and those undergoing dialysis.

The optimal hematocrit target range in children with end-stage renal disease, who are receiving recombinant human erythropoietin, is ambiguous due to the lack of compelling, age-appropriate studies. There are a large number of adult and pediatric studies which show that physical performance as well as morbidity and mortality are positively influenced by partial normalization of the hematocrit to 30 vol% to 36 vol%. Cognition studies performed in adults similarly show improvement with partial correction of hematocrit. Normalization of hematocrit studies show lower mortality rates, incremental further improvement in cognition, and greater resolution of cardiac anomalies when compared with patients with partial correction of anemia. Conversely, cardiac death rates may increase in adult patients receiving hemodialysis with preexisting cardiac disease, and there are concerns about the effect of recombinant human erythropoietin on catheter/shunt/fistula patency and on blood pressure. The high cost of recombinant human erythropoietin and established Medicare and Dialysis Outcomes Quality Initiative target hematocrit ranges have also influenced pediatric nephrologists in their assessment of the risk-benefit ratios, despite new adult data suggesting that maintenance of higher hematocrits may be cost-effective. The rationale of using adult-derived hematocrits in children with end-stage renal disease needs to be re-examined in the context of the unique growth and developmental requirements of children. A prospective, multicenter study which determines the relative benefits and risks of age-adjusted hematocrit normalization in children with renal failure is warranted.

The cytoplasmic domain of L-selectin participates in regulating L-selectin endoproteolysis.

Neutrophil recruitment at sites of inflammation is regulated by a series of adhesion and activation events. L-selectin (CD62L) is a leukocyte expressed adhesion protein that is important for neutrophil accumulation and rolling along the vascular endothelium. L-selectin is unique from other adhesion molecules involved in leukocyte transmigration in that its adhesiveness appears to be regulated partly by rapid endoproteolysis. Cleavage of L-selectin occurs within a membrane-proximal region that results in ectodomain shedding and retention of a 6-kDa transmembrane fragment. The cleavage domain of L-selectin has been well characterized through mutational analysis. Whether the cytoplasmic domain of L-selectin also plays a role in regulating shedding is controversial. We have previously shown that the Ca(2+)-sensing protein calmodulin (CaM) constitutively associates with the cytoplasmic domain of L-selectin in transfected cell lines. However, in the absence of mapping and mutational analysis of the CaM-binding region of L-selectin, there remains no direct evidence that this interaction affects shedding. Using synthesized peptides and expressed L-selectin constructs, we demonstrate that CaM binding activity occurs in the membrane-proximal region of the cytoplasmic domain. Mutations engineered in this region that prevent CaM binding increase the proteolytic turnover of L-selectin. Moreover, we demonstrate that CaM binding to the 6-kDa transmembrane fragment is greatly reduced compared with intact L-selectin in neutrophils, suggesting that CaM binding is regulated. These data imply that the cytoplasmic domain of L-selectin can regulate shedding by a mechanism in which bound CaM may operate as a negative effector.

Pulse methylprednisolone, cyclosporine, and ace inhibitor therapy decreases proteinuria in two siblings with familial focal segmental glomerulosclerosis.

Familial focal segmental glomerulosclerosis (FSGS) is a heterogeneous renal disease characterized by proteinuria and an unremitting deterioration of renal excretory function. Previous studies showed corticosteroid unresponsiveness and a variable response to cyclophosphamide therapy. We hypothesized that treatment with pulse methylprednisolone therapy (PMT), alternate-day corticosteroids, and cyclosphosphamide or cyclosporine would decrease proteinuria in patients with familial FSGS. Two adolescent brothers, 13 and 16 years old, presented with nephrotic range proteinuria, but with normal renal excretory function. Both brothers had renal biopsies that showed FSGS with mesangial hypercellularity and tubular atrophy. Intravenous PMT, at doses of 1 g, was initiated per the Tune-Mendoza protocol. Both patients received lisinopril therapy. One brother (case 1) was treated with PMT, alternate-day corticosteroids, and cyclophosphamide (total cumulative cyclophosphamide dose was 154.3 mg/kg). Urinary protein-to-urinary creatinine (UP/UC) ratios decreased from 6.79 to 3.79. Cyclosporine therapy decreased the UP/UC further from 2.48 to 0.76 at the end of PMT. The other brother (case 2), treated with PMT, alternate-day corticosteroids, and cyclosporine, experienced a decrease in UP/UC from 7.27 to 1.14. At the time of last evaluation, approximately 7 months after the last PMT dose, the UP/UC ratios were 0.27 (case 1) and 0.37 (case 2). PMT-attributable adverse effects were not severe. Both patients continued to receive oral cyclosporine and lisinopril after completion of PMT. PMT and cyclosporine therapy may reduce proteinuria, without decreasing renal excretory function, in some patients with familial FSGS. Further evaluation of cyclosporine therapy and PMT of patients with familial FSGS is warranted.

Loss of living donor renal allograft survival advantage in children with focal segmental glomerulosclerosis.

BACKGROUND: Because of concerns of increased risk of graft loss with recurrent disease, living donor (LD) transplantation in children with focal segmental glomerulosclerosis (FSGS) has been controversial. METHODS: The North American Pediatric Renal Transplant Cooperative Study (NAPRTCS) database from January 1987 to January 2000 was examined to determine differences in demographics, treatment, and outcomes in children with FSGS compared with other renal diseases. RESULTS: Data on 6484 children, 752 (11.6%) with FSGS, demonstrated that FSGS patients were more likely to be older and black, and were less likely to receive either pre-emptive or LD transplant (P < 0.001). No differences existed in human lymphocyte antigen (HLA) matching or immunosuppression regimens. Acute tubular necrosis occurred in more FSGS patients following LD (11.8 vs. 4.6%) or cadaveric (CD; 27.9 vs. 16.3%) transplants (P < 0.001). Graft survival was worse for LD FSGS patients (5 years 69%) compared with no FSGS (82%, P < 0.001) and was not significantly different than CD graft survival in the FSGS (60%) and No FSGS groups (67%). The LD to CD ratios of relative risk of graft failure were higher in FSGS patients (test for interaction, P = 0.01). Recurrence of original disease was the only cause of graft failure that differed between groups (P < 0.001). A greater percentage of LD FSGS graft failures was attributed to recurrence (P = 0.06). CONCLUSIONS: The impact of FSGS on graft survival in children is greatest in LD transplants, resulting in loss of expected LD graft survival advantage. The rationale for LD grafts in children with FSGS should be based on factors other than better outcomes typically associated with LD transplantation.

Long-term plasmapheresis and protein A column treatment of recurrent FSGS.

Transient or intermittent plasmapheresis with concurrent immunosuppressive therapy is thought to be beneficial in the treatment of recurrent focal segmental glomerulosclerosis (FSGS) in the early post-transplant period. The results of long-term (6-year) plasmapheresis therapy, in a 9-year-old female with an immediate recurrence of FSGS [urinary protein/urinary creatinine (UP/UC)=17.7] after cadaveric renal transplant, are presented. A 4-week plasmapheresis course induced a decline in the proteinuria, but a relapse occurred after cessation of plasmapheresis. Addition of protein A column therapy led to a further decrease in the proteinuria, to a non-nephrotic range. Long-term control of the nephrotic syndrome was established using a chronic treatment regimen consisting of a single-volume plasmapheresis, followed by a protein A column treatment, performed on sequential days every 3-4 weeks. Mean UP/UC values decreased to 1.15+/-0.9. A course of cyclophosphamide was successfully used to control a worsening of proteinuria 4 years post transplant. Although sequential renal biopsies demonstrated progressive glomerular sclerosis, the patient's mean calculated creatinine clearance only modestly declined from 78.3 ml/min per 1.73 m2, at the time of transplantation, to 62.7 ml/min per 1.73 m2, 6 years later. This patient demonstrated dependence on plasmapheresis/protein A column therapy to maintain a clinical remission of her FSGS recurrence. While long-term plasmapheresis and protein A column therapy in combination with immunosuppressive therapy reversed the effects of uncontrolled nephrosis and possibly facilitated long-term renal allograft survival, the glomerular sclerosis continued to progress.

Effects of selective protein kinase C inhibitors on the proteolytic down-regulation of L-selectin from chemoattractant-activated neutrophils.

The signaling factors that direct the rapid shedding of L-selectin from neutrophils upon chemoattractant stimulation are poorly understood. Protein kinase C (PKC) has been implicated, yet previous studies have relied on the use of phorbol esters and nonselective kinase inhibitors. We treated neutrophils with various selective kinase inhibitors to evaluate their effects on N-formyl-methionyl-leucyl-phenylalanine (fMLP)-induced L-selectin shedding. We found that three selective inhibitors of PKC, structurally related to staurosporine, largely blocked both fMLP- and phorbol 12-myristate 13-acetate (PMA)-induced L-selectin shedding; however, these inhibitors did not affect fMLP-induced up-regulation of Mac-1 (CD11b/CD18) expression, which has been shown not to involve PKC. Other selective serine, threonine, and tyrosine kinase inhibitors were found not to block fMLP-induced L-selectin shedding. These findings provide more definitive evidence for the role of PKC in chemoattractant-induced L-selectin proteolysis. It is interesting that certain highly selective PKC inhibitors, not structurally related to staurosporine, were found to directly induce L-selectin shedding from neutrophils.

Sodium ferric gluconate therapy in renal transplant and renal failure patients.

Intravenous infusion of sodium ferric gluconate (Ferrlecit) has been reported to be effective and safe in pediatric and adult hemodialysis patients with iron depletion. We sought to expand on the previous studies by treating 13 consecutive pediatric renal failure and renal transplant patients with sodium ferric gluconate doses that were higher than previously reported. Efficacy was defined as: (1) an increase in hematocrit of > or = 3 vol% with no change or a decrease in erythropoietin dose or (2) a stable hematocrit with a decrease of > or = 25% in the erythropoietin, 2 weeks to 2 months after sodium ferric gluconate infusion. Two dosing strategies were employed: (1) high dose, where single dose sodium ferric gluconate (mg) approximately calculated iron deficit, and (2) sodium ferric gluconate, 62.5 mg/dose for children < 40 kg, 125 mg/dose for children > 40 kg, infused on eight consecutive hemodialysis runs. There was only one self-limited adverse reaction in 60 doses. Three patients with previous adverse reactions to iron dextran tolerated sodium ferric gluconate without adverse effect. Sodium ferric gluconate was efficacious in eight out of ten patients that received a cumulative dose > 5 mg/kg. The mean hematocrit increased 30.3 +/- 7.8 to 36.4 +/- 4.4 vol% (P = 0.04) and the mean erythropoietin dose decreased 251.5 +/- 149.1 to 100.7 +/- 113.0 units/kg/week (P = 0.02). Although sodium ferric gluconate appears to be effective and safe at the doses used, multicenter, prospective pharmacokinetic and clinical trials of sodium ferric gluconate should be conducted in children.

Predictive factors for delayed graft function (DGF) and its impact on renal graft survival in children: a report of the North American Pediatric Renal Transplant Cooperative Study (NAPRTCS).

We define delayed graft function (DGF) as the need for dialysis during the first post-transplant week. We analyzed 5272 transplants, of which 2486 were of living donor (LD) and 2786 were of cadaver donor (CD) origin. Twelve per cent (620/5272) of all patients developed DGF. Donor specific rates were 5.6% for LD and 19.1% for CD patients. Factors predictive of DGF in CD patients were: African-American race (25%), prolonged cold ischemia (24%), absence of T-cell induction antibody therapy and absence of HLA-DR matching. The relative risk (RR) for graft failure due to DGF was 6.02 (p < 0.001) in LD patients and 2.58 (p < 0.001) for CD recipients. Two-year graft survival (GS) in LD patients without DGF was 89.6%, compared to 41.6% for those with DGF (p < 0.001); in CD patients it was 80.2% and 49.5%, respectively (p < 0.001). Censoring for primary non-function, GS for LD patients with a functioning graft at 30 d post-transplant and no DGF was 91.5%, compared to 70.1% for those with DGF (p < 0.001); GS for CD patients was 83.8% and 68.7%, respectively (p < 0.001). However, when patients whose grafts had failed during the first year were censored no differences in GS were noted between patients with and without DGF for either LD or CD recipients. To determine whether DGF acts as an independent risk factor for graft failure, patients were segregated into four groups: rejection with DGF; rejection without DGF; DGF without rejection; and no DGF, no rejection. When these groups were compared DGF emerged as an independent risk factor for graft failure. This large study reviewing pediatric renal transplantation over 10 yr clearly delineates the role of DGF as a major risk factor for graft failure.