Collaborative metabolisms of urea and cyanate degradation in marine anammox bacterial culture.

Anammox process greatly contributes to nitrogen loss occurring in oceanic oxygen minimum zones (OMZs), where the availability of NH4+ is scarce as compared with NO2-. Remineralization of organic nitrogen compounds including urea and cyanate (OCN-) into NH4+ has been believed as an NH4+ source of the anammox process in oxygen minimum zones. However, urea- or OCN-- dependent anammox has not been well examined due to the lack of marine anammox bacterial culture. In the present study, urea and OCN- degradation in a marine anammox bacterial consortium were investigated based on 15N-tracer experiments and metagenomic analysis. Although a marine anammox bacterium, Candidatus Scalindua sp., itself was incapable of urea and OCN- degradation, urea was anoxically decomposed to NH4+ by the coexisting ureolytic bacteria (Rhizobiaceae, Nitrosomonadaceae, and/or Thalassopiraceae bacteria), whereas OCN- was abiotically degraded to NH4+. The produced NH4+ was subsequently utilized in the anammox process. The activity of the urea degradation increased under microaerobic condition (ca. 32-42 µM dissolved O2, DO), and the contribution of the anammox process to the total nitrogen loss also increased up to 33.3% at 32 µM DO. Urea-dependent anammox activities were further examined in a fluid thioglycolate media with a vertical gradient of O2 concentration, and the active collaborative metabolism of the urea degradation and anammox was detected at the lower oxycline (21 µM DO).

Adherence to face-down and non-supine positioning after macular hole surgery.

BACKGROUND: This study aimed to investigate patient adherence to face-down positioning (FDP) and non-supine positioning (NSP) following vitrectomy with gas tamponade for treating macular holes (MHs). METHODS: Nursing records of 92 patients who underwent vitrectomy with gas tamponade for small-diameter (diameter < 400 µm) MHs during April 2016-June 2017 were examined. Forty-seven and 45 patients were instructed to maintain FDP and NSP (FDP and NSP groups), respectively. Patient adherence was evaluated seven times a day for 3 days, and the adherence rate was calculated. RESULTS: The mean adherence rate was significantly higher in the NSP group (99.3% ± 2.7%) than in the FDP group (93.7% ± 13.3%; P < 0.001, Mann-Whitney U test). Forty-one patients (91.1%) in the NSP group had an adherence rate of 100%, which was significantly higher than that in the 24 patients in the FDP group (51.1%; P < 0.001, chi-squared test). No statistically significant difference was observed between the patients in the two groups regarding sex, age, MH diameter, and pre- and postoperative visual acuities. MH closure was achieved in all patients. CONCLUSIONS: Almost half of the patients in the FDP group did not obtain 100% adherence rate, suggesting that patient adherence was largely compromised. Patient adherence was better in the NSP group as patient compliance to NSP was better, however, 8.9% of patients were found in face-up positioning at least once. Incompleteness of patient adherence was common, although to differing degrees.

CGI-58 facilitates lipolysis on lipid droplets but is not involved in the vesiculation of lipid droplets caused by hormonal stimulation.

A lipid droplet (LD)-associated protein, perilipin, is a critical regulator of lipolysis in adipocytes. We previously showed that Comparative Gene Identification-58 (CGI-58), a product of the causal gene of Chanarin-Dorfman syndrome, interacts with perilipin on LDs. In this study, we investigated the function of CGI-58 using RNA interference. Notably, CGI-58 knockdown caused an abnormal accumulation of LDs in both 3T3-L1 preadipocytes and Hepa1 hepatoma cells. CGI-58 knockdown did not influence the differentiation of 3T3-L1 adipocytes but reduced the activity of both basal and cAMP-dependent protein kinase-stimulated lipolysis. In vitro studies showed that CGI-58 itself does not have lipase/esterase activity, but it enhanced the activity of adipose triglyceride lipase. Upon lipolytic stimulation, endogenous CGI-58 was rapidly dispersed from LDs into the cytosol along with small particulate structures. This shift in localization depends on the phosphorylation of perilipin, because phosphorylated perilipin lost the ability to bind CGI-58. During lipolytic activation, LDs in adipocytes vesiculate into micro-LDs. Using coherent anti-Stokes Raman scattering microscopy, we pursued the formation of micro-LDs in single cells, which seemed to occur in cytoplasmic regions distant from the large central LDs. CGI-58 is not required for this process. Thus, CGI-58 facilitates lipolysis in cooperation with perilipin and other factors, including lipases.