Human liver stem cell-derived extracellular vesicles reduce injury in a model of normothermic machine perfusion of rat livers previously exposed to a prolonged warm ischemia

Livers from donors after circulatory death (DCD) are a promising option to increase the donor pool, but their use is associated with higher complication rate and inferior graft survival. Normothermic machine perfusion (NMP) keeps the graft at 37°C, providing nutrients and oxygen supply. Human liver stem cell-derived extracellular vesicles (HLSC-EVs) are able to reduce liver injury and promote regeneration. We investigated the efficacy of a reconditioning strategy with HLSC-EVs in an experimental model of NMP. Following total hepatectomy, rat livers were divided into 4 groups: (i) healthy livers, (ii) warm ischemic livers (60 min of warm ischemia), (iii) warm ischemic livers treated with 5 × 10⁸ HLSC-EVs/g-liver, and (iv) warm ischemic livers treated with a 25 × 10⁸ HLSC-EVs/g-liver. NMP lasted 6 h and HLSC-EVs (Unicyte AG, Germany) were administered within the first 15 min. Compared to controls, HLSC-EV treatment significantly reduced transaminases release. Moreover, HLSC-EVs enhanced liver metabolism by promoting phosphate utilization and pH self-regulation. As compared to controls, the higher dose of HLSC-EV was associated with significantly higher bile production and lower intrahepatic resistance. Histologically, this group showed reduced necrosis and enhanced proliferation. In conclusion, HLSC-EV treatment during NMP was feasible and effective in reducing injury in a DCD model with prolonged warm ischemia.     

Baseline Assessment of Circulating MicroRNAs Near Diagnosis of Type 1 Diabetes Predicts Future Stimulated Insulin Secretion

Type 1 diabetes is an autoimmune disease resulting in severely impaired insulin secretion. We investigated whether circulating microRNAs (miRNAs) are associated with residual insulin secretion at diagnosis and predict the severity of its future decline. We studied 53 newly diagnosed subjects enrolled in placebo groups of TrialNet clinical trials. We measured serum levels of 2,083 miRNAs, using RNA sequencing technology, in fasting samples from the baseline visit (<100 days from diagnosis), during which residual insulin secretion was measured with a mixed meal tolerance test (MMTT). Area under the curve (AUC) C-peptide and peak C-peptide were stratified by quartiles of expression of 31 miRNAs. After adjustment for baseline C-peptide, age, BMI, and sex, baseline levels of miR-3187-3p, miR-4302, and the miRNA combination of miR-3187-3p/miR-103a-3p predicted differences in MMTT C-peptide AUC/peak levels at the 12-month visit; the combination miR-3187-3p/miR-4723-5p predicted proportions of subjects above/below the 200 pmol/L clinical trial eligibility threshold at the 12-month visit. Thus, miRNA assessment at baseline identifies associations with C-peptide and stratifies subjects for future severity of C-peptide loss after 1 year. We suggest that miRNAs may be useful in predicting future C-peptide decline for improved subject stratification in clinical trials.     

Range of motion of foot joints following total ankle replacement and subtalar fusion

BackgroundIn severe cases of ankle and subtalar arthritis, arthrodesis of the subtalar joint is performed in combination with ankle arthroplasty. In these special cases gait analysis reveals real motion at the replaced tibiotalar joint.MethodsTwenty-three patients affected by ankle and subtalar arthritis, treated either with a 3-component or a 2-component prosthesis in combination with subtalar arthrodesis, were clinically evaluated preoperatively and at a minimum of 1-year follow-up. Gait analysis was performed postoperatively using a multi-segment foot protocol. Foot kinematics were compared to corresponding data from a healthy control group.ResultsClinical scores significantly improved from preoperative to follow-up. The clinically measured passive ankle dorsiflexion/plantarflexion significantly improved at the follow-up. Patients’ normalized walking speed and stride length were significantly lower than those in control. With exception of the ankle frontal-plane motion, sagittal-plane mobility of foot joints was about 50% than that in healthy joints.ConclusionsImprovement in clinical scores was found for both prostheses. Normal spatio-temporal parameters were not restored. In these patients, fusion of the subtalar joint appeared to be compensated by larger frontal-plane motion at the tibiotalar joint.Level of evidenceLevel III- retrospective comparative study.The study was approved by the local Ethics Committee as protocol MAT (protocol registration at clinicaltrials.gov NCT03356951).     

Adeno-associated viral vectors for retinal gene transfer and treatment of retinal diseases

Retinal gene transfer holds big promises for the treatment of inherited and non-inherited blinding diseases, such as retinitis pigmentosa or age-related macular degeneration. Key to the development of successful gene-based therapies for the eye are efficient tools for retinal gene transfer. Vectors based on adeno-associated viruses (AAV) are able to transduce robustly and persistently different retinal cell types of animal models after a single intraocular administration. Recombinant AAV (rAAV) vectors are versatile gene transfer tools in that capsid proteins from dozens of AAV serotypes can be easily interchanged, resulting in the creation of recombinant vectors with unique transduction properties. This has allowed successful proof-of-principle studies using rAAV-mediated gene transfer to restore retinal morphology and function in small and large animal models of retinal diseases. In addition, gene delivery using rAAV vectors in the eye seems to have appropriate biosafety characteristics to rapidly move it from bench to bedside. All the above aspects will be reviewed and discussed in detail below.     

Effects of 6-hydroxydopamine on pre- and post-junctional 5-HT1-like receptor-mediated responses in dog saphenous vein

Summary To investigate whether 5-HT₁-like receptor-mediated inhibition of adenosine 3 : 5-cyclic monophosphate (cyclic AMP) accumulation occurs in nerves or smooth muscle of saphenous vein, infusions of 6-hydroxydopamine (6-OHDA) were administered to dogs with the aim of inducing sympathetic nerve damage. The effects of 6-OHDA on other 5-HT₁-like receptor-mediated responses at the pre- and post-junctional level were investigated for comparison by studying 5-hydroxytryptamine (5-HT)-induced inhibition of ³H-noradrenaline release and contraction of smooth muscle respectively.Disruption of nerve function by 6-OHDA was revealed by the lack of catecholaminergic fluorescence and neurogenic contractile responses in saphenous veins from dogs treated with 6-OHDA. In addition, severe impairment of neuronal uptake mechanisms were apparent since basal efflux of ³H-noradrenaline, electrically-evoked release of ³H-noradrenaline and remaining ³H-noradrenaline content were considerably reduced. Some ³H-noradrenaline was taken up and released in 6-OHDA treated tissues which is consistent with the existence of nerve varicosities resistant to the present dosing regime of 6-OHDA, an observation substantiated by electron microscopy studies showing inconsistent lesions of nerve terminals.6-OHDA pre-treatment potentiated the smooth muscle contractile responses mediated by 5-HT₁-like receptors as well as potentiating 5-HT-evoked inhibition of prostaglandin E₂-stimulated cyclic AMP accumulation. It did not, however, affect 5-HT-induced inhibition of ³H-noradrenaline release. The present results suggest that inhibition of cyclic AMP accumulation by 5-HT occurs predominantly in smooth muscle. Correspondence to A. J. Kaumann at the above address     

Management of anorectal malformations during the newborn period

Anorectal malformations comprise a spectrum of disease. Some of these defects are minor, with an excellent functional prognosis. Others are complex and may be associated with other defects in the urinary tract that may risk the patient's life. The decision-making process for the management of a newborn with anorectal malformations is crucial; the timing and establishment of priorities are the key to success. Because the management of affected males and females differs significantly, they are discussed separately.

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Resumen Las malformaciones anorrectales comprenden todo un espectro de enfermedad. Algunos de los defectos son de naturaleza menor, fáciles de tratar y tienen un excelente pronóstico funcional. Otros son complejos, su manejo es difícil, su pronóstico incierto y algunoas veces se ven asociados con otros defectos en el tracto urinario que significan riesgo para la vida del paciente. El proceso de toma de decisión en el manejo de un recién nacido con malformación anorrectal es crucial porque determina el futuro inmediato y lejano del niño. Las más importantes decisiones a tomar durante este período son las relativas a la necesidad de una colostomía y sí el paciente requiere una derivación urinaria o vaginal con el fin de prevenir sepsis o acidosis metabólica. La definición de prioridades y su programación son la clave del éxito. Puesto que el manejo de estos pacientes difiere significativamente en los niños y en las niñas, se discuten por separado en este informe.

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Résumé Il existe une grande variété de malformations anorectales de l'enfant. Les malformations dites mineures sont faciles à réparer et leur pronostic est excellent. Parmi les variétés complexes, le traitement est difficile, le pronostic incertain, et parfois, lorsqu'il s'y associe des malformations urinaires, la vie de l'enfant est en jeu. De la décision thérapeutique, dépend étroitement le pronostic immédiat et tardif. Les problèmes essentiels concernent la décision de réaliser ou non une colostomie ou encore la nécessité de pratiquer une dérivation urinaire ou vaginale afin d'éviter une infection ou une acidose métabolique. Le traitement des malformations diffèrent naturellement entre le garçon et la fille et sera traité séparemment.

     

Immunohistochemical detection of p140trkA and p75LNGFR neurotrophin receptors in neuroblastoma

In neuroblastoma, high levels of mRNA for p14h ^trkA and p75 ^LNGFR neurotrophin receptors are predictive of favorable outcome. Their evaluation by Northern blot, however, requires substantial amounts of tissue and this prevents their routine evaluation as well as the possibility for multicenter studies to be easily carried out. In an attempt to overcome these limitations, the feasibility and reliability of determining both neurotrophin receptors on cryostat sections by immunohistochemistry were assessed, and these findings were compared to those obtained from Northern blot analysis. Primary tumor samples from 28 untreated patients at all stages were evaluated by using H10 anti-p140 ^trkA and ME20.4 anti-p75 ^LNGFR mAbs. Although weak, positiveimmunostaining was found in 9 of 28 tumors for p140 ^trkA and in 5 of 28 tumors for p75 ^LNGFR . As compared to Northern blot, the concordance rate was 79% (22 of 28 cases) for p140 ^trkA (p < 0.05) and 71% (20 of 28 cases) for p75 ^LNGFR (p < 0.05). No case negative for Northern blot was found to be positive with immunohistochemistry. Since only high mRNA levels for both receptors have been shown to be clinically relevant, their immunohistochemical detection, although less sensitive than Northern blot, can be just as sufficient and reliable as a prognostic tool, and possibly with a better cost-benefit ratio.     

Observations on the arterial baroreflex in neurally mediated vasodepressor syncope

The arterial baroreflex was studied in subjects who had recently had an episode of vasodepressor syncope. This was determined using 2–3 mcg/kg intravenous boluses of phenylephrine and assessing the bradycardic response. The values were measured in ms/mmHg and expressed as the angular coefficient of the regression line between the increase in R—R interval on the electrocardiograph and the systolic arterial pressure. In subjects examined immediately after the vasodepressor syncope episode the bradycardic response was much more marked than in controls (p < 0.01) and in the subjects themselves 6 months after the episode, provided that they were symptom-free (p < 0.01). It is concluded that in vasodepressor syncope there is a phase in which the baroreflex is highly sensitive and that this is due not to a lowering of the stimulation threshold but to a gain in the efferent arc, which explains a vagotonic response.