Isolated coarctation of the aorta in the fetus: A diagnostic challenge

Isolated coarctation of the aorta (CoA) is estimated by the Centers for Disease Control and Prevention to account for 4%–6% of all congenital heart disease (CHD) in the United States, with a reported prevalence of ~4 per 10 000 live births. Prenatal recognition of coarctation is important as it may improve neonatal survival and reduce morbidity. However, despite advances in imaging and the trend toward detailed aortic arch assessment as part of a comprehensive fetal echocardiogram, isolated CoA may still elude prenatal detection, with potentially lethal consequences if the diagnosis is not suspected and the patent ductus arteriosus (PDA) closes spontaneously in postnatal life. The purpose of this review is to outline the methods of antenatal aortic arch evaluation in the current era, discuss “red flags” that raise the suspicion for CoA, including associated anomalies and serve as a repository of the most up to date information regarding its diagnosis in utero and its perinatal management. Other aortic arch abnormalities, such as interrupted aortic arch, or CoA associated with complex single ventricles, are not included in this review.     

Imaging the right heart pulmonary circulation unit: Insights from advanced ultrasound techniques

The right heart pulmonary circulation unit (RH‐PCU) is a key determinant of prognosis in several cardiorespiratory diseases. Although right heart catheterization is considered the gold standard for pulmonary hemodynamic assessment, a comprehensive cardiovascular ultrasound approach is an essential step in the diagnostic–prognostic clinical pathway of patients with suspect or overt pulmonary hypertension. The exponential development of advanced ultrasound techniques (strain, 3‐dimensional echocardiography and lung ultrasound) has led to new insights into the evaluation of RH‐PCU structure and function, overcoming some limitations of standard Doppler echocardiography. In the near future, exercise Doppler echocardiography may become a useful technique for detecting a latent stage of pulmonary hypertension and for evaluating right ventricular contractile reserve.     

RNA interference unveils the importance of Pseudotrichonympha grassii cellobiohydrolase,a protozoan exoglucanase,in termite cellulose degradation

Based on prior work, a cellulase from glycosyl hydrolase family 7 (GHF7) was identified and found to be expressed at a high level in Coptotermes formosanus. To determine the function of GHF7 family members in vivo, we used RNA interference (RNAi) to functionally analyse the exoglucanase gene Pseudotrichonympha grassii cellobiohydrolase gene (PgCBH), which was highly expressed in Pseudotrichonympha grassii, a flagellate found in the hindgut of C. formosanus. In this study, the expression level of PgCBH was down‐regulated by RNAi, causing the death of P. grassii, but no effect was observed for other flagellates found in C. formosanus. RNAi also resulted in significantly reduced exoglucanase activity, and no effect was observed for endoglucanase and β‐glucosidase activities. This result demonstrated that the PgCBH gene plays a role in the protist lignocellulolytic process and is also important for host survival. PgCBH can be used as a target gene and has potential as a bioinsecticide for use against termites.     

Rifampicin reverses nicardipine effect inducing uncontrolled essential hypertension

Dihydropyridine calcium‐channel blockers are a known substrate for the cytochrome P450 isoform 3A4. Rifampicin, an antitubercular agent, is one of the most potent inducers of hepatic and intestinal CYP3A4 thus increasing dihydropyridine metabolism. We report a case of a 67‐year‐old hypertensive female treated with a four‐drug antihypertensive regimen including a dihydropyridine (nicardipine 50 mg bid), who was admitted for septic arthritis of the knee requiring antibiotic treatment with teicoplanin 400 mg od and rifampicin 600 mg bid. Six days after rifampicin initiation, she presented with Posterior Reversible Encephalopathy Syndrome due to uncontrolled hypertension. We hypothesized that disequilibrium of previously controlled hypertension was partially due to nicardipine ineffectiveness. Plasma nicardipine concentration was assessed through high‐performance liquid chromatography 5 hours after coadministration of the two drugs and proved undetectable.