Search

Bispecific antibodies (BsAbs) represent an emerging class of immunotherapy, but inefficiency in the current discovery has limited their broad clinical availability. Here we report a high throughput, agnostic, single-cell-based functional screening pipeline, comprising molecular and cell engineering for efficient generation of BsAb library cells, followed by functional interrogation at the single-cell level to identify and sort positive clones and downstream sequence identification and functionality characterization. Using a CD19xCD3 bispecific T cell engager (BiTE) as a model, we demonstrate that our single-cell platform possesses a high throughput screening efficiency of up to one and a half million variant library cells per run and can isolate rare functional clones at a low abundance of 0.008%. Using a complex CD19xCD3 BiTE-expressing cell library with approximately 22,300 unique variants comprising combinatorially varied scFvs, connecting linkers and VL/VH orientations, we have identified 98 unique clones, including extremely rare ones (~ 0.001% abundance). We also discovered BiTEs that exhibit novel properties and insights to design variable preferences for functionality. We expect our single-cell platform to not only increase the discovery efficiency of new immunotherapeutics, but also enable identifying generalizable design principles based on an in-depth understanding of the inter-relationships between sequence, structure, and function. A single-cell based bispecific antibody (BsAb) discovery pipeline, based on a microfluidics droplets generation and sorting systems, has the potential to speed up the discovery and development of functional antibodies such as BsAb therapeutics. [ABSTRACT FROM AUTHOR]

There is an increasing demand in the field of science education for the incorporation of philosophical and sociological aspects that are related to the scientific enterprise in school curricula, to the extent that the incorporation of these aspects is now considered a necessity. Several of these aspects can be categorised within the framework of the nature of science, or NOS. We warn that a possible misinterpretation of the common view of NOS tenets can lead to epistemic relativism. We pay special attention to the empirical and objective nature of science because these important features, properly understood, can help eliminate subjective flaws and protect against relativism. Some of the epistemological concepts that are relevant to this discussion are disambiguated in an attempt to prevent the temptation to take views to an extreme, as has occurred in some cases. We expect this analysis to contribute to the extant literature by improving how science is presented in the classroom without oversimplifying scientific practice. [ABSTRACT FROM AUTHOR]

A nitrifying consortium was kinetically, stoichiometrically and molecularly characterized via the in situ pulse respirometric method and pyrosequencing analysis before and after the addition of m-cresol (25 mg C L) in a sequencing batch reactor (SBR). Five important kinetic and stoichiometric parameters were determined: the maximum oxygen uptake rate, the maximum nitrification rate, the oxidation yield, the biomass growth yield, and the substrate affinity constant. An inhibitory effect was observed in the nitrification process with a recovery of this by up to eight SBR cycles after m-cresol was added to the system. However, full recovery of the nitrification process was not observed, as the maximum oxygen uptake rate was 25% lower than that of the previous operation without m-cresol addition. Furthermore, the pyrosequencing analyses of the nitrifying consortium after the addition of only two pulses of 25 mg C L m-cresol showed an important microbial community change represented by a decrease in the nitrifying populations and an increase in the populations degrading phenolic compounds. [ABSTRACT FROM AUTHOR]

A letter to the editor on issues related to backward reaction force on a fire hose is presented.

The experiment in which a candle is burned inside an inverted vessel partially immersed in water has a history of more than 2,200 years, but even nowadays it is common that students and teachers relate the change in volume of the enclosed air to its oxygen content. Contrary to what many people think, Lavoisier concluded that any change in volume in this experiment is negligible; moreover, the explanation relating oxygen consumption in the air with its change in volume is known to be wrong. In this work we briefly review the history behind the candle experiment and its relationship with some typical erroneous explanations. One of the key factors behind Lavoisier's success was the use of experiments carefully designed to test different hypotheses. Following these steps, we performed several closed volume experiments where the candle wick was replaced by a capillary stainless steel cylinder supported and heated by a nichrome filament connected to an external power supply. Our recorded experiments are displayed as web pages, designed with the purpose that the reader can easily visualize and analyze modern versions of Lavoisier's experiments. These experiments clearly show an initial phase of complete combustion, followed by a phase of incomplete combustion with elemental carbon or soot rising to the top of the vessel, and a final phase where the hot artificial wick only evaporates a white steam of wax that cannot ignite because no oxygen is left in the closed atmosphere. After either a complete or incomplete combustion of the oxygen, our experiments show that the final gas volume is nearly equal to the initial air volume. [ABSTRACT FROM AUTHOR]

The formation of the ophthalmic artery (OA) is a complex process with two different proposed embryological steps for its development. Several anatomical variants have been described. We present a very unusual origin of the ophthalmic artery from the basilar trunk, in a 45-year-old male with a history of pontine hemorrhagic stroke. MRI and CTA showed evidence of previous hemorrhage in the pons and several intracranial arterial dysplastic dilatations. DSA confirmed several fusiform dilatations of the basilar trunk. In the left ICA, no ophthalmic artery was seen arising from the carotid siphon. The left ophthalmic artery arises from the basilar trunk and runs lateral to the cavernous sinus through the middle cranial fossa, entering the left orbit at the superior orbital fissure. The patient was treated conservatively. Two main theories for this anomaly are known, one from Lasjaunias and the other from Paget. To our knowledge, this basilar origin of the OA has only been described three times in the literature. For its origin, we propose a partial persistence of the trigeminal artery together with a dominance of the dorsal ophthalmic artery. [ABSTRACT FROM AUTHOR]

The purpose of this study was to show the first reported case of a cerebral arteriovenous fistula (CAVF) from the anterior choroidal artery (AChoA) to the basal vein of Rosenthal in a Child. A 4-month-old male infant with no previous history presented a left thalamic intraparenchymal hemorrhage with secondary intraventricular spread and hydrocephalus. An external ventricular drainage was placed, and a digital subtracted angiography showed a left single hole CAVF. The left AChoA was the single arterial feeder directly connected to the ipsilateral basal vein of Rosenthal. After stabilization and good recovery, he was transferred to our institution for endovascular treatment. He was embolized using the arterial feeder with four Guglielmi detachable coils that produced complete exclusion of the fistula. The patient was discharged 10 days after the procedure without new neurological deficit. CAVFs are exceptional, with an incidence between 4.7% and 17% of all brain AVMs in large reported series. They can arise from any artery of the brain with a great dominance at the supratentorial location. This is the first reported case of a CAVF from the AChoA draining to the basal vein of Rosenthal. [ABSTRACT FROM AUTHOR]