Melatonin rescues zebrafish embryos from the parkinsonian phenotype restoring the parkin/PINK1/DJ‐1/MUL1 network

Multiple studies reporting mitochondrial impairment in Parkinson's disease (PD) involve knockout or knockdown models to inhibit the expression of mitochondrial‐related genes, including parkin, PINK1, and DJ‐1 ones. Melatonin has significant neuroprotective properties, which have been related to its ability to boost mitochondrial bioenergetics. The meaning and molecular targets of melatonin in PD are yet unclear. Zebrafish are an outstanding model of PD because they are vertebrates, their dopaminergic system is comparable to the nigrostriatal system of humans, and their brains express the same genes as mammals. The exposure of 24 hpf zebrafish embryos to MPTP leads to a significant inhibition of the mitochondrial complex I and the induction of sncga gene, responsible for enhancing γ‐synuclein accumulation, which is related to mitochondrial dysfunction. Moreover, MPTP inhibited the parkin/PINK1/DJ‐1 expression, impeding the normal function of the parkin/PINK1/DJ‐1/MUL1 network to remove the damaged mitochondria. This situation remains over time, and removing MPTP from the treatment did not stop the neurodegenerative process. On the contrary, mitochondria become worse during the next 2 days without MPTP, and the embryos developed a severe motor impairment that cannot be rescued because the mitochondrial‐related gene expression remained inhibited. Melatonin, added together with MPTP or added once MPTP was removed, prevented and recovered, respectively, the parkinsonian phenotype once it was established, restoring gene expression and normal function of the parkin/PINK1/DJ‐1/MUL1 loop and also the normal motor activity of the embryos. The results show, for the first time, that melatonin restores brain function in zebrafish suffering with Parkinson‐like disease.     

Impella 2.5 assisted balloon aortic valvuloplasty and percutaneous coronary intervention as a bridge to heart transplantation

Percutaneous left ventricular assist device (pLVAD) utilization is increasing as the potential applications expand. We report a case of high-risk balloon aortic valvuloplasty and percutaneous coronary intervention using the Impella 2.5 pLVAD in a patient with severely depressed left ventricular function as a bridge to heart transplantation.     

A meta-analysis of nutritional supplementation for management of hospitalized alcoholic hepatitis

BACKGROUND:

Alcoholic liver disease (ALD) is associated with a high risk of morbidity and mortality. Malnutrition accompanies this condition and may be both a consequence of and contributor to the pathology. Many trials have investigated the benefits of providing supplemental nutrition in the management of patients with ALD. The present study is a meta-analysis of the available evidence.

METHOD:

A meta-analysis of randomized controlled studies comparing nutritional supplementation plus a normal hospital diet versus diet alone.

RESULTS:

Seven randomized controlled studies including 262 patients with ALD were identified. Pooled analysis revealed no statistical difference in mortality between groups given special nutritional therapy versus a normal balanced diet (OR 0.80 [95% CI 0.42 to 1.52]). In addition, nutrition did not significantly improve ascites (OR 1.29 [95% CI 0.52 to 3.20]) or any biochemical parameters. However, encephalopathy showed a significant improvement or resolution (OR 0.24 [95% CI 0.06 to 0.93]).

CONCLUSION:

Nutritional supplementation provided no mortality benefit in patients with ALD, and neither ascites nor biochemical parameters significantly improved. However, encephalopathy was significantly ameliorated and, therefore, nutritional supplementation should be encouraged in that setting.     

Role of MRCP in assessment of biliary variants in living donor liver transplantation

Introduction

Liver transplantation can be done by three different methods: Cadaveric, heterotopic and living donor liver transplantation (LDLT). In LDLT usually the right lobe of a donor liver is transplanted into the patient after proper volumetric studies. The native patient bile ducts are connected to the biliary tree of the transplanted liver segment.

Patients and methods

From January 2010 to August 2011, 50 potential LDLT donors were evaluated with preoperative MRCP.

Results

The radiologist evaluated the visualization of the common duct, right and left intra-hepatic ducts, and insertion of the right posterior lobe duct. The data were classified according to Huang and Hakki classifications. According to the more detailed classification of Hakki 13 patients (26%) were Type K1; 15 patients (30%) were Type K2a; three patients (6%) were Type K2b; 11 patients (22%) Type K3a; four patients (8%) were Type K3b; two patients (4%) were Type K4 and no patients were Type K5. Two patients with unclassified anatomical biliary pattern were encountered. In conclusion, this study has shown an extremely high accuracy of MRCP in preoperative assessment of live hepatic donors, which aided in the style and procedure of the operation and ultimately to a high success rate of the transplantation procedures.     

Blood Flow in a Continuous Flow Ventricular Assist Device

A numerical analysis was performed to predict the shear stresses, flow rates, and the velocity profiles in a continuous flow ventricular assist device, the CFVAD3. The problem was modeled as a rotating disk over a stationary disk. A variety of clearances was tested for the CFVAD3 coupled with a range of rotational speeds and pressure gradients. Velocity fields were generated using solutions obtained with FLOW3D software (AEA Technology, Pittsburgh, PA, U.S.A.) Analysis of these solutions shows that the pressure differential effect has a stronger influence on the flow than the rotational effect of the impeller Ekman layer. The predicted shear stresses reflect these changes in the volume flow rates and the speeds shown in the velocity profiles. Based on the predictions of the software, the optimum clearance and rotational speed were chosen. The conclusion is that a speed in the range of 2,200-2,400 rpm should be chosen depending on the efficiency of the pump.