The microtubule end-binding proteins EB1 and Patronin modulate the spatiotemporal dynamics of myosin and pattern pulsed apical constriction

Apical constriction powers amnioserosa contraction during Drosophila dorsal closure. The nucleation, movement and dispersal of apicomedial actomyosin complexes generates pulsed apical constrictions during early closure. Persistent apicomedial and circumapical actomyosin complexes drive unpulsed constrictions that follow. Here, we show that the microtubule end-binding proteins EB1 and Patronin pattern constriction dynamics and contraction kinetics by coordinating the balance of actomyosin forces in the apical plane. We find that microtubule growth from moving Patronin platforms governs the spatiotemporal dynamics of apicomedial myosin through the regulation of RhoGTPase signaling by transient EB1-RhoGEF2 interactions. We uncover the dynamic reorganization of a subset of short non-centrosomally nucleated apical microtubules that surround the coalescing apicomedial myosin complex, trail behind it as it moves and disperse as the complex dissolves. We demonstrate that apical microtubule reorganization is sensitive to Patronin levels. Microtubule depolymerization compromised apical myosin enrichment and altered constriction dynamics. Together, our findings uncover the importance of reorganization of an intact apical microtubule meshwork, by moving Patronin platforms and growing microtubule ends, in enabling the spatiotemporal modulation of actomyosin contractility and, through it, apical constriction.

Mechanistic and recent updates in nano-bioremediation for developing green technology to alleviate agricultural contaminants

The rise in environmental pollutant levels in recent years is mostly attributable to anthropogenic activities such as industrial, agricultural and other activities. Additionally, these activities may produce excessive levels of dangerous toxicants such as heavy metals, organic pollutants including pesticide and herbicide chemicals, and sewage discharges from residential and commercial sources. With a focus on environmentally friendly, sustainable technology, new technologies such as combined process of nanotechnology and bioremediation are urgently needed to accelerate the cost-effective remediation process to alleviate toxic contaminants than the conventional remediation methods. Numerous studies have shown that nanoparticles possess special qualities including improved catalysis and adsorption as well as increased reactivity. Currently, microorganisms and their extracts are being used as promising, environmentally friendly catalysts for engineered nanomaterial. In the long term, this combination of both technologies called nano-bioremediation may significantly alter the field of environmental remediation since it is more intelligent, safe, environmentally friendly, economical and green. This review provides an overview of soil and water remediation techniques as well as the use of nano-bioremediation, which is made from various living organisms. Additionally, current developments related to the mechanism, model and kinetic studies for remediation of agricultural contaminants have been discussed.

Rare case of double looped ansa cervicalis associated with its deep position in the carotid triangle of the neck

Ansa cervicalis (AC) frequently shows its variations in the formation and distribution pattern. However, variation in its looping pattern associated with abnormal topographic disposition is relatively rare. Knowledge on the possible deviations in the looping pattern is clinically important, to avoid iatrogenic injuries in surgical procedures. We report here a concurrent rare case of double looped AC located deep to internal jugular vein. Anatomy of its superior root was normal, but the usual appearance of inferior root had gone astray due to formation of double loop. AC is being popularly used for nerve reconstructive surgery in treating paralyzed larynx, tongue hemiatrophy. Anatomical variation of it may potentially jeopardize the surgical procedures. Therefore, it is essential to the surgeons to be familiar with its unusual variations.

Terminal bifurcation of the right testicular vein and left testicular arterio-venous anastomosis

The testis is the organ upon which the survival of the human species depends. Abnormalities of testicular vessels may lead to loss of gametogenesis and hormone production. Reported here is a case of bilateral variations of the testicular vessels observed in a male cadaver during the first year MBBS dissection classes. The right testicular vein bifurcated into two veins just before its termination and both the branches terminated into the inferior vena cava. The left testicular artery arose from the abdominal aorta just above the level of origin of the inferior mesenteric artery. There was an arterio-venous anastomosis between the left testicular vein and the left testicular artery. The arterio-venous anastomosis might be functionally important as it can change the quality of the blood entering the testis.

Complete atrioventricular canal: current surgical technique

The technique we currently use for repair of complete atrioventricular canal requires 2 separate patches for closure of the atrial and ventricular portion of the defect. The common AV valve is left undivided and is sandwiched between these 2 patches. The cleft in the anterior mitral leaflet is left unsutured to create a trileaflet mitral valve. This technique has been employed in 10 patients (Type C: 9 patients; Type A: one patient; ages: 6 months to 4 1/2 years).