Cut-off values of haemoglobin and clinical outcomes in incident peritoneal dialysis: the PDTAP study.

BACKGROUND: To explore the cut-off values of haemoglobin (Hb) on adverse clinical outcomes in incident peritoneal dialysis (PD) patients based on a national-level database. METHODS: The observational cohort study was from the Peritoneal Dialysis Telemedicine-assisted Platform (PDTAP) dataset. The primary outcomes were all-cause mortality, major adverse cardiovascular events (MACE) and modified MACE (MACE+). The secondary outcomes were the occurrences of hospitalization, first-episode peritonitis and permanent transfer to haemodialysis (HD). RESULTS: A total of 2591 PD patients were enrolled between June 2016 and April 2019 and followed up until December 2020. Baseline and time-averaged Hb <100 g/l were associated with all-cause mortality, MACE, MACE+ and hospitalizations. After multivariable adjustments, only time-averaged Hb <100 g/l significantly predicted a higher risk for all-cause mortality {hazard ratio [HR] 1.83 [95% confidence interval (CI) 1.19-281], P = .006}, MACE [HR 1.99 (95% CI 1.16-3.40), P = .012] and MACE+ [HR 1.77 (95% CI 1.15-2.73), P = .010] in the total cohort. No associations between Hb and hospitalizations, transfer to HD and first-episode peritonitis were observed. Among patients with Hb ≥100 g/l at baseline, younger age, female, use of iron supplementation, lower values of serum albumin and renal Kt/V independently predicted the incidence of Hb <100 g/l during the follow-up. CONCLUSION: This study provided real-world evidence on the cut-off value of Hb for predicting poorer outcomes through a nation-level prospective PD cohort.

Oral vitamin D supplementation on the prevention of peritoneal dialysis-related peritonitis: A pilot randomised controlled trial.

OBJECTIVE: Peritoneal dialysis (PD)-related peritonitis is independently associated with low serum 25-hydroxy vitamin D [25(OH)D] levels. Our objective is to examine the feasibility of conducting a large, randomised controlled trial to determine the effects of vitamin D supplementation on the risk of PD-related peritonitis. DESIGN: Pilot, prospective, open-label randomised controlled trial. SETTING: Peking University First Hospital, China. PARTICIPANTS: Patients receiving PD who had recovered from a recent episode of peritonitis between 30 September 2017 and 28 May 2020. INTERVENTIONS: Oral natural vitamin D supplementation (2000 IU per day) versus no vitamin D supplementation for 12 months. PRIMARY AND SECONDARY OUTCOME MEASURES: Primary outcomes were feasibility (recruitment success, retention, adherence, safety) and fidelity (change in serum 25(OH)D level during follow-up) for a large, randomised controlled trial in the future to determine the effects of vitamin D on PD-related peritonitis. Secondary outcomes were time to peritonitis occurrence and outcome of subsequent peritonitis. RESULTS: Overall, 60 among 151 patients were recruited (recruitment rate was 39.7%, 95% CI 31.9-47.5%, recruitment rate among eligible patients was 61.9%, 95% CI 52.2-71.5%). Retention and adherence rates were 100.0% (95% CI 100.0-100.0%) and 81.5% (95% CI 66.8-96.1%), respectively. During follow-up, serum 25(OH)D levels increased in the vitamin D (VD) group (from 19.25 ± 10.11 nmol/L to 60.27 ± 23.29 nmol/L after 6 months, p < 0.001, n = 31), and remained higher (p < 0.001) than those in the control group (n = 29). No differences were observed between the two groups with respect to time to subsequent peritonitis (hazard ratio 0.85, 95% CI 0.33-2.17) or any of the peritonitis outcomes. Adverse events were uncommon. CONCLUSIONS: A randomised controlled trial of the effect of vitamin D supplementation on peritonitis occurrence in patients receiving PD is feasible, safe and results in adequate serum 25(OH)D levels.

The effects of oral vitamin D supplementation on the prevention of peritoneal dialysis-related peritonitis: study protocol for a randomized controlled clinical trial.

BACKGROUND: Vitamin D deficiency has been shown to be closely associated with peritoneal dialysis (PD)-related peritonitis. The aim of this study is to examine the feasibility of conducting a large, powered randomized controlled trial to determine the effects of vitamin D supplementation on the risk of PD-related peritonitis in patients who have already experienced an episode of peritonitis. METHODS: This prospective, open-label randomized controlled pilot trial with blinded end-points aims to determine the feasibility of oral vitamin D supplementation and to explore its effects on the risk of subsequent PD-related peritonitis among PD patients who have recovered from a recent episode of peritonitis. Eligible patients will be randomized 1:1 to either oral vitamin D supplementation (2000 IU per day; intervention group) or no vitamin D supplementation (control group) in addition to usual care according to International Society for Peritoneal Dialysis guidelines. The sample size will be 30 patients for both groups. All participants will be followed for 12 months. The primary outcome is the assessment of feasibility (recruitment success, retention, adherence, safety) and fidelity (change in serum 25-hydroxyvitamin D level during follow-up) for a large, powered randomized controlled trial to determine the effects of vitamin D on the risk of PD-related peritonitis in the future. Secondary outcomes include time to peritonitis occurrence, recovery of peritonitis, peritonitis-related transition to hemodialysis, and peritonitis-related death (defined as death within 30 days of peritonitis onset). DISCUSSION: This is the first randomized controlled trail investigating the effects of vitamin D supplementation on the risk of subsequent PD-related peritonitis among patients on PD. The findings for this pilot study will determine the feasibility of conducting a full-scale randomized controlled trail, which may provide a new strategy for preventing PD-related peritonitis among PD patients. TRIAL REGISTRATION: Clinicaltrails.gov, NCT03264625. Registered on 29 August 2017.

Intraperitoneal Vancomycin Plus Either Oral Moxifloxacin or Intraperitoneal Ceftazidime for the Treatment of Peritoneal Dialysis-Related Peritonitis: A Randomized Controlled Pilot Study.

BACKGROUND: Intraperitoneal administration of antibiotics is recommended as a first treatment for managing peritoneal dialysis (PD)-related peritonitis. However, the efficacy of oral administration of quinolones has not been well studied. STUDY DESIGN: Randomized controlled pilot study. SETTING & PARTICIPANTS: 80 eligible patients with PD-related peritonitis from Peking University First Hospital (40 in each arm). INTERVENTION: Intraperitoneal vancomycin, 1g, every 5 days plus oral moxifloxacin, 400mg, every day (treatment group) versus intraperitoneal vancomycin, 1g, every 5 days plus intraperitoneal ceftazidime, 1g, every day (control group). OUTCOMES: The primary end point was complete resolution of peritonitis, and secondary end points were primary or secondary treatment failure. MEASUREMENTS: PD effluent white blood cell count. RESULTS: Baseline demographic and clinical characteristics of the 2 groups were comparable. There were 24 and 22 Gram-positive organisms, 6 and 7 Gram-negative organisms, 9 and 10 culture-negative samples, and 1 and 1 fungal sample in the treatment and control groups, respectively. Complete resolution of peritonitis was achieved in 78% and 80% of cases in the treatment and control groups, respectively (OR, 0.86; 95% CI, 0.30-2.52; P=0.8). There were 3 and 1 cases of relapse in the treatment and control groups, respectively. Primary and secondary treatment failure rates were not significantly different (33% vs 20% and 10% vs 13%, respectively). In each group, there was 1 peritonitis-related death and 6 transfers to hemodialysis therapy. During the 3-month follow-up period, 7 and 3 successive episodes of peritonitis occurred in the treatment and control groups, respectively. Only 2 adverse drug reactions (mild nausea and mild rash, respectively) were observed in the 2 groups. LIMITATIONS: Sample size was relatively small and the eligibility ratio was low. Also, the number of peritonitis episodes was low, limiting the power to detect a difference between groups. CONCLUSIONS: This pilot study suggests that intraperitoneal vancomycin with oral moxifloxacin is a safe, well-tolerated, practical, and effective first-line treatment for PD-related peritonitis. Larger adequately powered clinical trials are warranted.

Examination of metabolic responses to phosphorus limitation via proteomic analyses in the marine diatom Phaeodactylum tricornutum.

Phosphorus (P) is an essential macronutrient for the survival of marine phytoplankton. In the present study, phytoplankton response to phosphorus limitation was studied by proteomic profiling in diatom Phaeodactylum tricornutum in both cellular and molecular levels. A total of 42 non-redundant proteins were identified, among which 8 proteins were found to be upregulated and 34 proteins were downregulated. The results also showed that the proteins associated with inorganic phosphate uptake were downregulated, whereas the proteins involved in organic phosphorus uptake such as alkaline phosphatase were upregulated. The proteins involved in metabolic responses such as protein degradation, lipid accumulation and photorespiration were upregulated whereas energy metabolism, photosynthesis, amino acid and nucleic acid metabolism tend to be downregulated. Overall our results showed the changes in protein levels of P. tricornutum during phosphorus stress. This study preludes for understanding the role of phosphorous in marine biogeochemical cycles and phytoplankton response to phosphorous scarcity in ocean. It also provides insight into the succession of phytoplankton community, providing scientific basis for elucidating the mechanism of algal blooms.

Systems-level analysis of the metabolic responses of the diatom Phaeodactylum tricornutum to phosphorus stress.

Phosphorus is an important macronutrient. To understand the molecular and cellular responses to phosphorus stress better, transcriptome profiling in combination with biochemical investigations was conducted in the model diatom Phaeodactylum tricornutum. Out of 10 402 predicted genes, 2491 and 405 genes were significantly upregulated or downregulated respectively. Unsurprisingly, genes associated with phosphate uptake were upregulated, such as the phosphate transporters and alkaline phosphatases. Genes encoding stress-shock proteins were accordingly upregulated, including genes associated with stress-responsive proteins, signal transduction and secondary metabolism. Additionally, genes related to protein translation, carbon fixation, glycolysis and the citric acid cycle were also upregulated. Genes associated with gene transcription were downregulated, thereby resulting in the upregulation of translation to compensate for the limited supply of messenger RNA. The downregulation of genes related to ß-oxidation could contribute to the accumulation of fatty acids. Accordingly, triacylglycerols, which are important for energy storage, were determined to increase by 1.65-fold. Intracellular membranes, other than chloroplast membranes, tended to be dispersed; this finding was in accordance with the increased transcription of a total of 11 genes encoding putative phospholipases. Taken together, this work revealed the coordination of multiple metabolic pathways and certain key genes in the adaptation of P. tricornutum to phosphorus stress.

Low-level laser irradiation alters cardiac cytokine expression following acute myocardial infarction: a potential mechanism for laser therapy.

OBJECTIVES: Low-level laser irradiation (LLLI) has the potential of exerting cardioprotective effect following myocardial infarction (MI). The authors hypothesized that LLLI could influence the expression of cardiac cytokines and contribute to the reversal of ventricular remodeling. BACKGROUND: LLLI regulates the expression of cytokines after tissue damage. However, little is known concerning the alteration of the cardiac cytokine expression profile after LLLI. METHODS: MI was created by coronary ligation. The surviving rats were divided randomly into laser and control groups. 33 rats were exposed to a diode laser (635 nm, 5 mW, CW, laser, beam spot size 0.8 cm(2), 6 mW/cm(2), 150 sec, 0.8 J, 1J/cm(2)) as laser group. Another 33 rats received only coronary ligation and served as control group. 28 rats received a thoracotomy without coronary ligation (sham group). One day after laser irradiation, 5 rats from each group were sacrificed and the heart tissues were analyzed by cytokine antibody arrays. Enzyme-linked immunosorbent assay (ELISA) was performed to confirm its reliability. Two weeks after MI, cardiac function and structure were evaluated by echocardiography and histological study. RESULTS: Cytokine antibody array indicated 4 cytokines were significantly changed after laser therapy. ELISA confirmed that granulocyte-macrophage colony stimulating factor and fractalkine were the cytokines involved in the response to therapeutic laser irradiation. However, there was no difference in cytokine release between various groups at 2 weeks after MI. Although LLLI did not improve the damaged heart function, it did reduce the infarct area expansion. CONCLUSIONS: The antibody-based protein array technology was applied for screening the cytokine expression profile following MI, with or without laser irradiation. The expression of multiple cytokines was regulated in the acute phase after LLLI. Our results revealed a potential novel mechanism for applying laser therapy to the treatment of heart disease.