Sex Chromosome Pairing Mediated by Euchromatic Homology in Male Meiosis.

Diploid germline cells must undergo two consecutive meiotic divisions before differentiating as haploid sex cells. During meiosis I, homologs pair and remain conjoined until segregation at anaphase. spermatocytes are unique in that the canonical events of meiosis I including synaptonemal complex formation, double-strand DNA breaks, and chiasmata are absent.

Fascia iliaca block, history, technique, and efficacy in clinical practice.

The facsia iliaca block (FIB) is a relatively new regional technique where local anesthetic is delivered within the fascia iliaca region. Indications for a FIB include surgical anesthesia to the lower extremity after knee, femoral shaft, hip surgery, management of cancer pain or pain secondary to inflammatory conditions of the lumbar plexus, as well as treatment of acute pain in the setting of trauma, fracture, or burns. The FIB may be performed using either a loss of resistance technique or an ultrasound (US)-guided technique; however, the use of US has become commonplace and resulted in improved femoral nerve and obturator nerve motor blocks.

A role for cyclic AMP response element-binding protein (CREB) but not the highly similar ATF-2 protein in sterol regulation of the promoter for 3-hydroxy-3-methylglutaryl coenzyme A reductase.

Sterol regulatory element-binding proteins (SREBPs) activate promoters for key genes of metabolism to keep pace with the cellular demand for lipids. In each SREBP-regulated promoter, at least one ubiquitous co-regulatory factor that binds to a neighboring recognition site is also required for efficient gene induction. Some of these putative co-regulatory proteins are members of transcription factor families that all bind to the same DNA sequence elements in vitro and are often expressed in the same cells.