Effectiveness of mechanical recanalization for intraluminal occlusion of totally implantable venous access ports

Purpose: To evaluate if the mechanical injection of saline is effective in restoring patency of a totally implantable venous access port (TIVAP) with an intraluminal occlusion. Materials and methods: From January 2017 to June 2019, 64 cases of dysfunction of a TIVAP were referred to interventional radiology. Among these, 16 cases showed normal function of the TIVAP, 19 cases the showed the appearance of a fibroblastic sheath, and 29 cases showed intraluminal occlusion. Mechanical recanalization was performed for intraluminal occlusion of the TIVAP with an indeflator and a 20G non-coring needle. Linograms were performed in all recanalized cases. The success or failure of recanalization and the pressure of the indeflator were recorded. Linograms were evaluated for breakage or migration of catheters. Medical records were retrospectively reviewed. Results: Among the 29 intraluminal occlusion cases, 24 cases (82.7%) were recanalized by mechanical recanalization via an indeflator. The pressure of the indeflator ranged from 29 to 220 psi (median: 118 psi). Linograms revealed breakage of the catheter of the TIVAP in two failed cases. The median interval from implantation to dysfunction was 405 days (range: 43–1723 days). The median interval from last use to dysfunction was 8 days (mean: 15.4 days; range: 1–119 days). The median re-occlusion free period after successful mechanical recanalization was 100.5 days (range: 6–859 days). Conclusion: In the absence of an available thrombolytic agent, mechanical injection of saline was a tolerable alternative method for restoring occluded catheters and sustaining the function of catheters. Because breakage of the catheter can occur during mechanical recanalization of a TIVAP, a linogram should follow the procedure.

TMEM95 is a sperm membrane protein essential for mammalian fertilization

The fusion of gamete membranes during fertilization is an essential process for sexual reproduction. Despite its importance, only three proteins are known to be indispensable for sperm-egg membrane fusion: the sperm proteins IZUMO1 and SPACA6, and the egg protein JUNO. Here we demonstrate that another sperm protein, TMEM95, is necessary for sperm-egg interaction. TMEM95 ablation in mice caused complete male-specific infertility. Sperm lacking this protein were morphologically normal exhibited normal motility, and could penetrate the zona pellucida and bind to the oolemma. However, once bound to the oolemma, TMEM95-deficient sperm were unable to fuse with the egg membrane or penetrate into the ooplasm, and fertilization could only be achieved by mechanical injection of one sperm into the ooplasm, thereby bypassing membrane fusion. These data demonstrate that TMEM95 is essential for mammalian fertilization.

Mechanical recanalization for clot occlusion of venous access ports: experimental study using ports with clot occlusion

Purpose To test the hypothesis that mechanical injection of saline is safe and effective in restoring patency of totally implantable venous access ports (TIVAPs) with clot occlusion. We devised an experimental port model for the evaluation of mechanical TIVAP recanalization prior to its clinical application. Materials and Methods The clot TIVAP occlusion model was constructed by filling the catheter with swine blood and incubating it at 37.5°C. The model was incubated for different lengths of time ranging from 1 day to 7 days. Each incubation time point included 20 ports. Total catheter occlusion of the TIVAPs was assessed with a 10-mL saline syringe equipped with a non-coring needle. Occlusion was defined as no passage of saline through the catheter when it was aspirated and infused gently with the 10-mL saline syringe. Pressure was evaluated during recanalization with an indeflator. Histological examination was performed on the clot obtained during recanalization. Results Among the 140 total experimental ports, 65 occlusions (46.4%) were detected. Of these 65 occlusions, 56 (86.1%) were recanalized by mechanical saline pressure via the indeflator. The indeflator pressure ranged from 29 pound per square-inch (psi) to 265 psi at mechanical catheter recanalization (mean: 110 psi). Histologically, all specimens from the model ports exhibited a similar appearance; specifically, erythrocytes, cells, and fibrin were evenly scattered throughout the clot. Conclusions Our data indicate that it is feasible to generate a TIVAP clot occlusion model with swine blood. Moreover, mechanical recanalization was suitable for resolving occluded catheters without thrombolytic agents.

Sheep oocyte activation after intracytoplasmic sperm injection (ICSI)

The effect of calcium concentration on fertilization and activation was examined in oocytes injected in vitro with sperm. Oocytes were subjected to sperm injection, to sham injection or remained uninjected, and were then cultured for 19 h in bicarbonate-buffered synthetic oviduct fluid (BSOF) without calcium, or containing either calcium chloride or calcium ionophore. There was no difference in fertilization rates after ICSI when oocytes were cultured in vitro in media containing calcium chloride or calcium ionophore but the rate was lower in calcium-free media. There was also no difference in the fertilization rate after ICSI when oocytes were culturedin vivocompared with that observedin vitro in media containing calcium chloride or calcium ionophore. In calcium chloride-treated oocytes, activation was induced by mechanical injection, and in calcium ionophore-treated oocytes, by the ionophore. In uninjected oocytes, calcium itself did not cause oocyte activation. It is concluded that it is possible to induce activation by the injection process, but that manipulation alone is inadequate to cause proper oocyte activation unless calcium is also present. No difference in oocyte activation between ICSI and sham injection was found, indicating that the sperm may play no role in the early events of oocyte activation.