OBJECTIVEThis study measures the glutaredoxin (Grx) gene and protein expression in umbilical vein endothelial cells upon exposure to Porphyromonas gingivalis (P. gingivalis) lipopolysaccharide (LPS). The involvement of the Akt-signaling pathway is also determined.

METHODSEA-hy926 cells were pretreated with 1,000 ng · mL⁻¹ P. gingivalis LPS for 4, 12, 18, and 24 h, and then real-time reverse transcription polymerase chain reaction was employed to detect Grx1 expression. The effect of Grx on Akt activity was investigated using Western blot for the control, LPS (1,000 ng · mL⁻¹ LPS), and carmus- tine (BCNU) groups (1,000 ng · mL⁻¹ LPS, and the EA-hy926 cells were pretreated with 25 μmol · ml⁻¹ BCNU for 30 min).

RESULTSGene expression of Grx1 significantly increased in LPS group compared with that in the control group. The Grx1 expression reached the peak level in 12 h, and the variation between the expression in 4 and 12 h was significant (P < 0.05). After 12 h, the protein levels of Grx and phosphorylated-Akt (p-Akt) significantly increased in the LPS group (P < 0.05), whereas the BCNU group showed a considerable decrease in both Grx and p-Akt expression levels (P < 0.05). Moreover, a slight difference was observed in the total Akt protein levels in the three groups (P > 0.05).

CONCLUSIONGrx expression increased upon exposure of EA-hy926 cells to the LPS. Akt activity could be inhibited by BCNU (a Grx inhibitor), which indicated that Akt might act as a downstream regulator of Grx.

Endothelial Cells ; Glutaredoxins ; genetics ; Humans ; Lipopolysaccharides ; pharmacology ; Oxidative Stress ; drug effects ; Phosphorylation ; Porphyromonas gingivalis ; pathogenicity ; Proto-Oncogene Proteins c-akt ; drug effects ; Signal Transduction ; drug effects ; Umbilical Veins

Objective:To analyze the relationship between blood electrolytes and the prognosis of patients with severe coronavirus disease 2019 (COVID-19) and to provide assistance for clinical decision-making.Methods:The clinical data of patients with severe COVID-19 admitted to intensive care unit (ICU) of the Wuhan Third Hospital by the Shanghai aid-Hubei medical team from January 21 to March 4, 2020 were collected. Excluding ineligible patients, 110 patients were finally enrolled. The patients' gender, age, temperature, heart rate, systolic and diastolic blood pressure, clinical symptoms at admission, time of symptom onset, duration of fever, and relevant indicators at admission to ICU (including blood potassium, chloride, sodium, calcium, phosphorus, and magnesium, etc.) and prognosis were analyzed. The patients were grouped by blood potassium or calcium levels or blood potassium/calcium ratio. The Kaplan-Meier survival curves were used to analyze the survival of patients in each group. The relationship between the potassium/calcium ratio and the prognosis was analyzed using restricted cubic spline plots. The relationship between each index in the different models and the prognosis was analyzed using Cox regression models.Results:Among 110 severe COVID-19 patients, 78 cases survived, and 32 cases died. Compared with the surviving group, patients in the death group had higher blood potassium levels [mmol/L: 4.25 (3.80, 4.65) vs. 3.90 (3.60, 4.20), P < 0.05] and lower blood calcium levels (mmol/L: 2.00±0.14 vs. 2.19±0.18, P < 0.05). The Kaplan-Meier survival curves showed that patients in the potassium > 4.2 mmol/L group had a worse prognosis than the potassium < 3.8 mmol/L group and the potassium 3.8-4.2 mmol/L group ( P = 0.011), patients in the calcium > 2.23 mmol/L group had a better prognosis than the calcium < 2.03 mmol/L group and the calcium 2.03-2.23 mmol/L group, and the lower calcium group had a worse prognosis ( P = 0.000 15). Cox regression analysis showed that the hazard ratio ( HR) of blood potassium and calcium were 2.08 and 0.01, respectively, in model 1 (single blood potassium or calcium) and in model 2 (model 1 plus age and gender), the HR of blood potassium and calcium were 1.98 and 0.01 respectively, which were significantly associated with patient prognosis (all P < 0.05). Patients in the group with the potassium/calcium ratio > 1.9 had higher blood potassium levels and a higher proportion of mechanical ventilation, lower calcium levels and lower proportion of survival, and longer time of ICU admission compared with the groups with the potassium/calcium ratio < 1.7 and 1.7-1.9. The Kaplan-Meier survival curves showed that the survival rate of the potassium/calcium ratio > 1.9 group was the lowest ( P < 0.000 1), and there was no statistically significant difference in survival between the potassium/calcium ratio < 1.7 group and the potassium/calcium ratio 1.7-1.9 group. A restricted cubic spline plot corrected for age and gender showed that patients in the potassium/calcium ratio > 1.8 group had HR values > 1. Cox regression analysis corrected for other indicators showed that the potassium/calcium ratio was still associated with patient prognosis ( HR = 4.85, P = 0.033). Conclusions:Blood potassium, calcium, and the potassium/calcium ratio at ICU admission are related to the prognosis of patients with severe COVID-19, and the potassium/calcium ratio is an independent risk factor for the death of patients. The higher the potassium/calcium ratio, the worse the prognosis of patients.

Gingival pigmentation is a nonplaque gum disease. Patients are often afraid to communicate with others because of gum color problems, which affect the social and mental health of patients. The commonly used treatment methods for gingival pigmentation include scalpel excision, gingival grinding, laser therapy, cryosurgery and electrosurgery. In this paper, the progress of gingival pigmentation treatment was reviewed in terms of bleeding, pain, tissue healing and recoloring. The results showed that the clinical effect of laser treatment was better. Among them, the semiconductor laser had more advantages in reducing bleeding, pain and the restaining rate, while the Er:Cr:YSSG/Er:YAG laser performed better for promoting tissue healing. Clinicians can choose the best kind of laser to use according to the actual situation. For patients with thin gingival biotypes, floating gingival transplantation or substitute materials can be selected to restore the gingival morphology. With the in-depth study of melanin regulation mechanisms, various drugs, such as ascorbic acid, natural peptides, synthetic peptides and derivatives, may be the main research direction for the treatment of gingival pigmentation in the future.