Comparison of bursting pressure after scleral tunnel incision sealed with sutures or an adherent ocular bandage in human globes.

OBJECTIVE: To evaluate the efficiency of a hydrogel adherent ocular bandage for sealing of scleral tunnel incisions in human eye globes. METHODS: A 4-mm scleral tunnel incision was made in each of 10 globes and bursting pressure was measured using the Seidel test to check for wound leakage. Globes were sealed using either two interrupted 10-0 nylon sutures (n = 5) or an adherent ocular bandage in the form of polyethylene glycol hydrogel (n = 5). Bursting pressure was then measured for a second time. RESULTS: Bursting pressure was significantly higher after wound sealing in both groups. There were no statistically significant differences in bursting pressure between the two groups before or after sealing. CONCLUSIONS: The adherent ocular bandage successfully protected the incision in ex vivo human globes immediately after surgery, with a sealing efficiency comparable to two nylon sutures, suggesting that it is a safe and effective alternative to conventional suturing.

Nitric oxide synthase distribution during implantation in the mouse.

The peri-implantation period is a critical time during murine development. Although the importance of nitric oxide has been demonstrated during gestation, its role in implantation has not been fully defined. The aim of this study was to quantify (by Western blotting) two prominent nitric oxide synthase (NOS) isoforms, inducible (iNOS) and endothelial (eNOS) and localize all three forms [iNOS, eNOS, and neuronal (nNOS)] by immunohistochemistry in uterine tissue from days 4 through 8 of pregnancy. By day 6, iNOS values were significantly elevated in implantation sites compared with interimplantation regions and continued to rise through day 8. Analysis of eNOS was similar, but implantation site values peaked by days 6 and 7. Labelled iNOS cells were within the decidua, around myometrial vessels, and within the ectoplacental cone. At implantation, eNOS was conspicuous, displaying label adjacent to the embryo in vessels of the primary decidual zone. nNOS was localized mainly in the mesometrium and myometrium and did not appear to change throughout the peri-implantation period. The increased iNOS and eNOS values following implantation in the embryonic site may imply roles in tissue remodelling, immunosuppression and vasoregulation. Nitric oxide may play an important role in the mechanisms of implantation where these factors are keys to successful pregnancy.

Inducible nitric oxide synthase is present in the rat placenta at the fetal-maternal interface and decreases prior to labour.

The aim of this study was to investigate the expression and distribution patterns of the inducible isoform of nitric oxide synthase (iNOS) in rat placenta during gestation and term labour. The expression of iNOS isoform was assessed by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) and immunoblotting with monoclonal antibodies. Two specific bands were detected corresponding to 135 and 124 kDa in all placenta samples. The upper band (135 kDa) was identified as iNOS due to its correspondence with the band obtained with mouse macrophages (positive control). Compared with its concentrations on day 16, iNOS decreased steadily toward the end of gestation to approximately 37% on day 20, 20% on day 22 before labour and 12% during labour (p < 0.01). The lower band (124 kDa) drastically increased (to almost double) from day 16 to day 18 but returned to initial values on day 22, during delivery. Immunohistochemical staining of placentae at day 16 and 22 using rabbit polyclonal anti-iNOS antibody revealed labelling specifically concentrated in the trophospongial cell layer, at the fetal-maternal interface. The most conspicuous iNOS staining was associated with islands of cells referred to as vacuolated 'glycogen cells'. Staining was greatly decreased during labour. The changes in placental iNOS expression suggest a 'paracrine' role for NO in regulating uterine contractility, blood flow and immunosuppression required for pregnancy maintenance. NO withdrawal at term may also be involved in the initiation of labour.