Extracardiac complications of the Fontan circuit

The Fontan operation is the primary surgical procedure used in the palliation of patients with univentricular cardiac physiology. With improved survival of children with congenital heart disease, long-term complications of the Fontan circuit are being encountered more frequently. Radiologists are more likely to see both the cardiac and extracardiac complications of the Fontan circuit. Awareness of the common extracardiac complications in children with failing Fontan circuits will aid the radiologist in making the appropriate diagnosis and guide the cardiologist caring for these patients.     

Poly(N-vinylcaprolactam) containing solid lipid polymer hybrid nanoparticles for controlled delivery of a hydrophilic drug gemcitabine hydrochloride

Folic acid tagged and hydrophilic polymer containing solid lipid nanoparticles (SLNs) were formulated for the controlled and targeted delivery of gemcitabine, a hydrophilic drug. Drug loaded SLNs were prepared by double emulsion method and optimized by 3² level factorial design. Then, a hydrophilic polymer, namely, poly(N-vinylcaprolactam) (PVCL) was incorporated in the optimized SLN batch in the first aqueous phase (W1) to obtain solid lipid polymer hybrid nanoparticles (SLPHNs) that were further decorated with folic acid (F-SLPHNs). TEM analysis of SLNs and SLPHNs revealed the spherical shape with no aggregation while SLPHNs showed higher % EE. SLPHNs exhibited limited burst release of gemcitabine compared to SLNs as well as lower overall % release. All the formulations showed good cytocompatibility against MDA-MB-231 cell lines and folic acid-tagged hybrid particles (F-SLPHNs) showed remarkably higher cellular uptake.

A hydrophilic polymer, poly(N-vinylcaprolactam), incorporated into solid lipid nanoparticles (SLNs) imparts better encapsulation and controlled release of gemcitabine.     

SARS-CoV-2, the pandemic coronavirus: Molecular and structural insights

The outbreak of a novel coronavirus associated with acute respiratory disease, called COVID-19, marked the introduction of the third spillover of an animal coronavirus (CoV) to humans in the last two decades. The genome analysis with various bioinformatics tools revealed that the causative pathogen (SARS-CoV-2) belongs to the subgenus Sarbecovirus of the genus Betacoronavirus, with highly similar genome as bat coronavirus and receptor-binding domain (RBD) of spike glycoprotein as Malayan pangolin coronavirus. Based on its genetic proximity, SARS-CoV-2 is likely to have originated from bat-derived CoV and transmitted to humans via an unknown intermediate mammalian host, probably Malayan pangolin. Further, spike protein S1/S2 cleavage site of SARS-CoV-2 has acquired polybasic furin cleavage site which is absent in bat and pangolin suggesting natural selection either in an animal host before zoonotic transfer or in humans following zoonotic transfer. In the current review, we recapitulate a preliminary opinion about the disease, origin and life cycle of SARS-CoV-2, roles of virus proteins in pathogenesis, commonalities, and differences between different corona viruses. Moreover, the crystal structures of SARS-CoV-2 proteins with unique characteristics differentiating it from other CoVs are discussed. Our review also provides comprehensive information on the molecular aspects of SARS-CoV-2 including secondary structures in the genome and protein–protein interactions which can be useful to understand the aggressive spread of the SARS-CoV-2. The mutations and the haplotypes reported in the SARS-CoV-2 genome are summarized to understand the virus evolution.     

Long-term nutritional consequences of bowel segment use for lower urinary tract reconstruction in pediatric patients

Objectives

To identify whether nutritional abnormalities, specifically vitamin B₂ deficiency, folate deficiency, and low carotene levels, are long-term sequelae of the use of ileum and/or colon for lower urinary tract reconstruction in pediatric patients.

Methods

Serum levels of vitamin B₁₂, methyl malonic acid (MMA), carotene, and folate were measured 3 to 13 years (mean 6) after surgery in patients less than 18 years old at the time of operation.

Results

Thirteen (44.8%) of 29 patients had abnormal nutritional serum levels, with 5 (38.5%) of 13 having more than one abnormal value. Vitamin B₁₂ was low in 4 (14%) of 29 patients; MMA was abnormally high in 7 (26%) of 27; and both folate and carotene levels were low in 4 (14.8%) of 27. No patient with reconstruction with colon alone (n = 3) had abnormal values, and no patient had any clinical signs or symptoms of vitamin B₁₂ deficiency or fat malabsorption.

Conclusions

Nutritional abnormalities can occur in patients after lower urinary tract reconstruction with ileum. No patient in this study had symptomatic abnormalities; however, long-term clinical effects may be significant. The implications of low folate levels in women of childbearing age must also be taken into consideration because of the potential association with congenital anomalies.     

Therapeutic endoscopic retrograde cholangiopancreatography: what the future holds

These are exciting times for interventional endoscopists performing ERCP. The advent of noninvasive, diagnostic techniques of the pancreaticobiliary tree has resulted in a shift toward more therapeutic procedures. The combination of major technologic advances together with endoscopists' growing comfort with invasive procedures has helped to push the boundaries of endoscopic therapy. These therapies, however, should always be sanctioned by sound science and well-controlled clinical trials.