Elevations of sperm Ca 2؉ seem to be responsible for an asymmetric form of motility called hyperactivation, which is first seen near the time of fertilization. The mechanism by which intracellular Ca 2؉ concentrations increase remains unknown despite considerable investigation. Although several prototypical voltage-gated calcium channels are present in spermatozoa, they are not essential for motility. Furthermore, the forward velocity and percentage of motility of spermatozoa are associated with infertility, but their importance relative to hyperactivation also remains unknown. We show here that disruption of the gene for a recently described sperm-specific voltage-gated cation channel, CatSper2, fails to significantly alter sperm production, protein tyrosine phosphorylation that is associated with capacitation, induction of the acrosome reaction, forward velocity, or percentage of motility, yet CatSper2 ؊͞؊ males are completely infertile. The defect that we identify in the null sperm cells is a failure to acquire hyperactivated motility, which seems to render spermatozoa incapable of generating the ''power'' needed for penetration of the extracellular matrix of the egg. A loss of power is suggested also by experiments in which the viscosity of the medium was increased after incubation of spermatozoa in normal capacitating conditions. In highviscosity medium, CatSper2-null spermatozoa lost the ability to swim forward, whereas wild-type cells continued to move forward. Thus, CatSper2 is responsible for driving hyperactivated motility, and, even with typical sperm forward velocities, fertilization is not possible in the absence of this highly active form of motility.hyperactivation ͉ spermatozoa ͉ infertility

This biofilm study was conducted to assess the in vitro activity of tetrasodium EDTA on catheters that had been routinely removed from hemodialysis patients at Leeds Teaching Hospitals Trust due to maturation of fistula. Catheters were screened by culture of through-catheter flush, and isolates were identified by standard methodologies; 20 isolates were found to be biofilm positive. Initial biofilm cell count levels averaged above 10 5 CFU/1-cm catheter section. Bacteria identified in the biofilms were gram-negative (1 isolate), gram-positive (11 isolates), or mixed species (8 isolates). After a 24-h lock, 40 mg of tetrasodium EDTA per ml was effective at eradicating the total biofilm viable count in almost all cases. The efficacy of tetrasodium EDTA as a catheter lock potentially shows that this agent could substantially reduce catheter-related infections and be used to treat patients with limited access.Catheters have become essential in the management of critical-care patients, yet the inside of a catheter is a major source of infection due to biofilms (1, 3). It has been found that at least 70% of all nosocomial bloodstream infections occur in patients with central venous catheters (7). Traditionally, catheters have been locked with normal saline or heparin solutions, sometimes in combination, to provide anticoagulant activity. Normal saline is generally used to lock short-term peripheral intravenous catheters, but saline has no anticoagulant or antimicrobial activity. Heparin solutions are generally used to lock vascular catheters. Heparin has anticoagulant activity, but it does not function as an antimicrobial and therefore does not provide protection from catheter-related infections. Recently, antibiotic lock solutions, with or without an anticoagulant (such as vancomycin-heparin), have been used for the prevention and management of catheter-related bacteremia (2,8,15). However, there are concerns, particularly with the use of a vancomycin flush solution, because of the potential for the development of resistant organisms (5, 9).EDTA is a calcium and iron chelator with anticoagulant activity. However, as a disodium salt it has been documented to have limited antistaphylococcal and anti-Candida activities (6,12,13). In contrast to this was a study by Raad et al., who demonstrated that minocycline and EDTA have highly synergistic activities in the decontamination of catheter surfaces when they are combined in a solution (10). It was found in that study that minocycline-EDTA was active against staphylococci, gram-negative bacilli, and Candida organisms that colonize polymers. This suggests a possible role of EDTA in catheter lock procedures.We undertook the present study by using in vivo renal lines in an in vitro technique to test the efficacy of tetrasodium EDTA on catheters removed from patients in order to determine its potential as a catheter lock solution to treat preformed biofilms and, ultimately, catheter-related infections. MATERIALS AND METHODSExperimental design. The study was conducted at the Le...

Appropriate temporospatial expression of the transcription factor SOX9 is important for normal development of a wide range of organs. Here, we show that when SOX9 is expressed ectopically, target genes become expressed that are associated with disease. Histone deacetylase inhibitors in clinical trials for cancer therapy induced SOX9 expression via enhanced recruitment of nuclear factor Y (NF-Y) to CCAAT elements in the SOX9 proximal promoter. The effect of histone deacetylase inhibitors could be elicited in cells that normally lack SOX9, such as hepatocytes. In human fetal hepatocytes, this aberrant induction of SOX9 protein caused ectopic expression of COL2A1 and COMP1 that encode extracellular matrix (ECM) components normally associated with chondrogenesis. Previously, ectopic expression of this "chondrogenic" profile has been implicated in vascular calcification. More broadly, inappropriate ECM deposition is a hallmark of fibrosis. We demonstrated that induction of SOX9 expression also occurred during activation of fibrogenic cells from the adult liver when the transcription factor was responsible for expression of the major component of fibrotic ECM, type 1 collagen. These combined data identify new aspects in the regulation of SOX9 expression. They support a role for SOX9 beyond normal development as a transcriptional regulator in the pathology of fibrosis.