Doppler echography in the intraoperative assessment of the liver circulation: an experimental study in swine

In this experimental study the authors report an experience in the evaluation of hepatic blood flow with intraoperative echo-Doppler during orthotopic liver transplantation and side-to-side or end-to-side portacaval shunt. Doppler ultrasonography studied the flow of portal vein, hepatic artery and inferior vena cava before the recipient hepatectomy, and after reperfusion during liver grafting. Furthermore echo-Doppler of the portal system was performed to confirm portacaval shunt efficacy. Usually intraoperative Doppler ultrasonography may give informations about the patency of the shunt and regarding the development of early hepatic artery thrombosis during liver transplantation, but often unclear is the exact evaluation of the velocity of the blood flow through the liver. Further experimental studies and clinical evaluations need to find safe parameters and markers of vascular alteration using this superior diagnostic procedure.     

Nonunion fracture healing: Evaluation of effectiveness of demineralized bone matrix and mesenchymal stem cells in a novel sheep bone nonunion model

Nonunion treatment has a high rate of success, although recalcitrant nonunion may determine the need for amputation. Therefore, new treatment options are continuously investigated in order to further reduce the risk of nonunion recurrence. This study aimed to (a) develop a new large animal model for bone atrophic nonunion and (b) compare the efficacy of demineralized bone matrix (DBM) and DBM in combination with mesenchymal stem cells (MSC) in the new nonunion model. The new model consists of a noncritical, full‐thickness segmental defect created in the sheep tibia, stabilized by an intramedullary nail, and involves the creation of a locally impaired blood supply achieved through periosteum excision and electrocauterization of the stump ends. Six weeks after defect creation, lack of hard tissue callus and established nonunion was observed in all operated tibiae both by radiographic and clinical evaluation. Nonunion was treated with allogeneic DBM or autologous MSC cultivated on DBM particles (DBM + MSC) for 1 day before implantation. Twelve weeks after treatment, radiographic, microtomographic, histologic, and histomorphometric analysis showed the formation of bone callus in DBM group, whereas the fracture healing appeared at an early stage in DBM + MSC group. Torsional strength and stiffness of the DBM group appeared higher than those of DBM + MSC group, although the differences were not statistically significant. In conclusion, a new sheep bone nonunion model resembling the complexity of the clinical condition was developed. DBM is an effective option for nonunion treatment, whereas MSC do not improve the healing process when cultivated on DBM particles before implantation.     

Delirium in COVID-19 patients: a multicentric observational study in Italy

Neurological Sciences - Although recent data show that SARS-CoV-2 infection seems to affect the central nervous system (CNS), little is known about the neuropsychiatric effects resulting from this...     

Insulin resistance and endothelial function in children and adolescents

Aims

Insulin resistance (IR) impairs cellular response to insulin due to a dysfunction in glucose metabolism, associated with an increased cardiovascular risk. The aim of our study was to investigate the relationship among homeostasis model assessment index (HOMA index), endothelial function and vascular morphology in order to better stratify cardiovascular risk in children and adolescents.

Methods

A total of 150 children and adolescents (55 pre-pubertal, mean age 10.4 ± 3.1 years) were enrolled. Anthropometric [body mass index (BMI), waist circumference (WC)], laboratory [blood lipids, inflammatory markers, insulinemia, glycemia], HOMA index and ultrasound parameters [flow-mediated dilatation (FMD), common carotid intima–media thickness (cIMT) and antero-posterior diameter of infra-renal abdominal aorta (APAO)] were assessed.

Results

cIMT was positively related to age (r = 0.274, p < 0.01), BMI (r = 0.318, p < 0.01), WC (r = 0.315, p < 0.01) and triglycerides (r = 0.230, p < 0.01). APAO measurements showed a linear positive correlation with age (r = 0.435, p < 0.01), BMI (r = 0.505, p < 0.01), WC (r = 0.487, p < 0.01), triglycerides (r = 0.280, p < 0.01), C-reactive protein (r = 0.209, p < 0.05), fasting insulin (r = 0.378, p < 0.01) and HOMA index (r = 0.345, p < 0.01). FMD was inversely related to age (r = − 0.251, p < 0.01), rough BMI (r = − 0.318, p < 0.01), WC (r = − 0.340, p < 0.01), fasting insulin (r = − 0.281, p < 0.01) and HOMA index (r = − 0.282, p < 0.01). Multiple regression analysis found no influence of HOMA index on APAO and cIMT. HOMA index was an independent predictor for brachial artery FMD worsening after the statistical adjustment.

Conclusion

HOMA index increase induced a worsening in endothelial function since childhood.     

Markers of Alzheimer's disease in a population attending a memory clinic

BackgroundNew marker-based criteria for the diagnosis of Alzheimer's disease (AD) were recently proposed. We describe their operational translation in 144 consecutive patients referred to our Memory Clinic.MethodsVisual ratings of hippocampal atrophy and of cortical glucose hypometabolism in magnetic resonance imaging and positron emission tomography, and concentrations of total tau and Aβ1-42 in cerebrospinal fluid were assessed in 12 patients with subjective memory complaints (SMCs) (Mini-Mental State Examination [MMSE] score, 28.0 ± 1.1 [mean ± SD]), 37 with mild cognitive impairment (MCI) (MMSE, 25.1 ± 3.6), 55 with AD (MMSE, 21.1 ± 3.5), and 40 with non-AD dementia (MMSE, 21.6 ± 5.5).ResultsThe sensitivity for AD of each individual biomarker was higher (65% to 87%) than for MCI (18% to 50%). Each biomarker's specificity for SMC and non-AD dementias was good to moderate (83% and 53%). Positivity for at least one marker increased the probability 38 times of belonging to the AD group (P < 0.0001).ConclusionThe new diagnostic criteria can be operationalized in clinical routines, but longitudinal studies of MCI patients will need to assess the criteria's prognostic value.