Pediatric transplantation in Europe during the COVID-19 pandemic: Early impact on activity and healthcare

The current pandemic SARS-CoV-2 has required an unusual allocation of resources that can negatively impact chronically ill patients and high-complexity procedures. Across the European Reference Network on Pediatric Transplantation (ERN TransplantChild), we conducted a survey to investigate the impact of the COVID-19 outbreak on pediatric transplant activity and healthcare practices in both solid organ transplantation (SOT) and hematopoietic stem cell transplantation (HSCT). The replies of 30 professionals from 18 centers in Europe were collected. Twelve of 18 centers (67%) showed a reduction in their usual transplant activity. Additionally, outpatient visits have been modified and restricted to selected ones, and the use of telemedicine tools has increased. Additionally, a total of 14 COVID-19 pediatric transplanted patients were identified at the time of the survey, including eight transplant recipients and six candidates for transplantation. Only two moderate-severe cases were reported, both in HSCT setting. These survey results demonstrate the limitations in healthcare resources for pediatric transplantation patients during early stages of this pandemic. COVID-19 disease is a major worldwide challenge for the field of pediatric transplantation, where there will be a need for systematic data collection, encouraging regular discussions to address the long-term consequences for pediatric transplantation candidates, recipients, and their families.     

Guanethidine and related agents: III. Antagonism by drugs which inhibit the norepinephrine pump in man

Antagonism of the antihypertensive action of guanethidine by the tricyclic antidepressants, desipramine and protriptyline, has been demonstrated in controlled studies. These antidepressants also prevent the effect of the related ring-substituted guanidinium adrenergic neuron blockers, bethanidine and debrisoquin. That the rise in blood pressure when desipramine is added to guanethidine therapy is not due simply to a pressor action of the two drugs in combination was demonstrated by the lack of an increase in blood pressure when guanethidine was added to desipramine therapy.Investigations were conducted to determine whether antagonism of guanethidine's clinical effect could result from blockade by the tricyclic antidepressants of the norepinephrine pump in the adrenergic neuron membrane, thereby preventing the uptake of guanethidine into the neuron by this pump. Like guanethidine, the indirectly acting pressor amine, tyramine, enters the neuron via the norepinephrine pump. Desipramine, protriptyline, and amitriptyline in clinical doses all were found to block the pressor action of tyramine while potentiating the pressor effect of norepinephrine. The amino acid, methyldopa, does not enter the neuron via the norepinephrine pump, and its antihypertensive action is not altered by concomitant administration of tricyclic antidepressants. It is concluded from the evidence in this investigation together with the results of previous studies in experimental animals that clinical doses of desipramine-like drugs inhibit the norepinephrine pump in the peripheral adrenergic neuron in man and thereby prevent uptake of guanethidine to its site of action.     

Role of neuronal activity and kinesin on tract tracing by manganese-enhanced MRI (MEMRI)

MEMRI offers the exciting possibility of tracing neuronal circuits in living animals by MRI. Here we use the power of mouse genetics and the simplicity of the visual system to test rigorously the parameters affecting Mn2+ uptake, transport and trans-synaptic tracing. By measuring electrical response to light before and after injection of Mn2+ into the eye, we determine the dose of Mn2+ with the least toxicity that can still be imaged by MR at 11.7 T. Using mice with genetic retinal blindness, we discover that electrical activity is not necessary for uptake and transport of Mn2+ in the optic nerve but is required for trans-synaptic transmission of this tracer to distal neurons in this pathway. Finally, using a kinesin light chain 1 knockout mouse, we find that conventional kinesin is a participant but not essential to neuronal transport of Mn2+ in the optic tract. This work provides a molecular and physiological framework for interpreting data acquired by MEMRI of circuitry in the brain.     

Renal tight junction proteins are decreased in cisplatin-induced nephrotoxicity in rats

Cisplatin (CP) is an antineoplastic agent that induces nephrotoxicity and oxidative stress. It is unknown whether renal tight junction (TJ) proteins expression and localization are modified in CP-induced nephrotoxicity.

Objective: To study if the expression of the TJ proteins occludin, claudin-2, claudin-5 and zonula occludens-1 (ZO-1) is modified in rats with CP-induced nephrotoxicity.

Materials and methods: Male Wistar rats (n?=?5/group) were injected with saline solution (V group), and the other group (CP group) was injected with a single dose of saline solution and CP (7.5?mg/kg i.p.). Rats were sacrificed 72?h after CP injection and blood, and 24-h urine samples were collected. Several plasma and urinary injury biomarkers as well as renal histopathology lesions, oxidative and nitrosative stress markers were evaluated, and protein levels of ocludin, claudin-2, claudin-5, ZO-1 were measured by Western blot. Statistically significant changes noted with different p?Results: Nephrotoxicity was evident by histological alterations, glycosuria, decrease in creatinine clearance, increase in fractional excretion of sodium, serum creatinine and kidney injury molecule-1. These changes were associated with oxidative/nitrosative stress (increased renal abundance of 3-nitrotyrosine and protein kinase Cβ2 and decreased renal expression of nuclear factor-erythroid-2-related factor 2) and decreased activity of antioxidant enzymes. Finally, it was found that CP-induced renal damage was associated with decreased renal expression of occludin and claudin-2.

Discussion and conclusion: CP altered the TJ proteins expression and localization in the proximal tubule that was associated with oxidative/nitrosative stress.     

Robotic Partial Nephrectomy with Superselective Versus Main Artery Clamping: A Retrospective Comparison

Background

Concerns have been raised regarding partial nephrectomy (PN) techniques that do not occlude the main renal artery.

Objective

Compare the perioperative outcomes of superselective versus main renal artery control during robotic PN.

Design, setting, and participants

A retrospective analysis of 121 consecutive patients undergoing robotic PN using superselective control (group 1, n = 58) or main artery clamping (group 2, n = 63).

Intervention

Group 1 underwent tumor-specific devascularization, maintaining ongoing arterial perfusion to the renal remnant at all times. Group 2 underwent main renal artery clamping, creating global renal ischemia.

Outcome measurements and statistical analysis

Perioperative and functional data were evaluated. The Pearson chi-square or Fisher exact and Wilcoxon rank sum tests were used.

Results and limitations

All robotic procedures were successful, all surgical margins were negative, and no kidneys were lost. Compared with group 2 tumors, group 1 tumors were larger (3.4 vs 2.6 cm, p = 0.004), more commonly hilar (24% vs 6%, p = 0.009), and more complex (PADUA 10 vs 8, p = 0.009). Group 1 patients had longer median operative time (p < 0.001) and transfusion rates (24% vs 6%, p < 0.01) but similar estimated blood loss (200 vs 150 ml), perioperative complications (15% vs 13%), and hospital stay. Group 1 patients had less decrease in estimated glomerular filtration rate at discharge (0% vs 11%, p = 0.01) and at last follow-up (11% vs 17%, p = 0.03). On computed tomography volumetrics, group 1 patients trended toward greater parenchymal preservation (95% vs 90%, p = 0.07) despite larger tumor size and volume (19 vs 8 ml, p = 0.002). Main limitations are the retrospective study design, small cohort, and short follow-up.

Conclusions

Robotic PN with superselective vascular control enables tumor excision without any global renal ischemia. Blood loss, complications, and positive margin rates were low and similar to main artery clamping. In this initial developmental phase, limitations included more perioperative transfusions and longer operative time. The advantage of superselective clamping for better renal function preservation requires validation by prospective randomized studies.

Patient summary

Preserving global blood flow to the kidney during robotic partial nephrectomy (PN) does not lead to a higher complication rate and may lead to better postoperative renal function compared with clamped PN techniques.     

Management of Early-stage Esophageal Neoplasia (MESEN) Consensus

Background

Treatment of esophageal adenocarcinoma often involves surgical resection. Newer technologies in interventional endoscopy have led to a substantial paradigm shift in the management of early-stage neoplasia in Barrett’s esophagus comprising high-grade dysplasia (HGD), intramucosal carcinoma, and, in some cases, submucosal carcinoma. However, there has been no consensus regarding the indications for esophageal preservation in these cases. In this work, consensus guidelines were established for the management of early-stage esophageal neoplasia considering clinically relevant aspects (age, comorbidities, and social environment) in each scenario.

Methods

Seventeen experts were invited to participate based on their background and clinical expertise at high-volume centers. A questionnaire was created that included four clinical scenarios covering a wide range of situations within HGD and/or early esophageal neoplasia, particularly where controversies are likely to exist. Each of the clinical scenarios was open to discussion subdivided by patient age (20, 50, and 80 s). For each clinical scenario an expert was chosen to defend that position. Each defense triggered a subsequent discussion during a consensus meeting. Conclusions of that discussion together with an accompanying literature analysis allowed experts to confirm or change their original choices and served as the basis for the recommendations stated in this article.

Results

There was 100 % consensus supporting esophageal preservation in patients with HGD, independent of patient age or Barrett’s length. In patients with T1a adenocarcinoma, consensus for preservation was not reached (65 %) for young and middle-aged individuals but was supported for elderly patients (100 %). For T1b adenocarcinoma, consensus was reached for surgical resection (90 %), leaving organ preservation for patients with very low risk of nodal invasion or poor surgical candidates.

Conclusion

Advances in endoscopic imaging and therapy allow for organ preservation in most settings of early-stage neoplasia of the esophagus, provided that the patient understands the implications of this decision.