The sexual activity of aged Paramecium that underwent about 700 fissions after conjugation was remarkably decreased. Microinjection of a soluble cytoplasmic fraction prepared from young immature cells (about 20 fissions after conjugation) restored the sexual activity of the aged cells to that of presenescent mature cells. The factor responsible for the recovery of the sexual activity was shown ...

Erythrocyte-mediated microinjection was used to introduce [35S]polypeptides translated in vitro into 3T3-L1 cells. Such [35S]polypeptides are not degraded after loading into erythrocytes and are stable for the first 2 h after microinjection into growing 3T3-L1 cells. Similarly, little or no degradation of microinjected [35S]polypeptides is observed in either growing or confluent 3T3-L1 cells ov...

This paper discusses challenges related to the automatic microinjection of single adherent cells. The discussion covers all necessary components of a capillary pressure microinjection system: a micromanipulator, a microinjector, a microcapillary, a vision system and an environment control system. The other part of the paper describes the research performed on the automatic capillary pressure mi...

The aim of this work was to study the participation of alpha- and beta-adrenergic receptors on the effect of microinjection of angiotensin II (A II) into the medial preoptic area (MPOA) on the secretion of luteinizing hormone (LH), follicle-stimulating hormone (FSH) and prolactin (PRL) in estrogen-primed ovariectomized (OVX) rats. Microinjection of A II into the MPOA increased plasma LH. This e...

Microinjection into cells and embryos is a common technique that is used to study a wide range of biological processes. In this method a small amount of treatment solution is loaded into a microinjection needle that is used to physically inject individual immobilized cells or embryos. Despite the need for initial training to perform this procedure for high-throughput delivery, microinjection of...

Direct Laser Writing In article number 2201641, Ryan D. Sochol and co-workers present a hybrid additive manufacturing strategy for 3D nanoprinting arrays of hollow, high-aspect-ratio microneedles at unprecedented scales. Microneedle array-mediated injections microfluidic cargo into mouse brains yield distributed delivery over large coverage area, holding unique promise emerging biomedical micro...