Comparative Study for Efficacy and Safety of Adenoidectomy according to the Surgical Method: A Prospective Multicenter Study

Background/Objective

There have been several operative techniques for adenoidectomy and their efficacy and morbidity are different according to the technique. This prospective multicenter study was aimed to compare the efficacy and morbidity of coblation adenoidectomy (CA) with those of power-assisted adenoidectomy.

Study Design

Prospective multi-institutional study.

Methods

Children who underwent CA, power-assisted adenoidectomy with cauterization (PAA+C) or without cauterization (PAA-C) due to adenoid hypertrophy were enrolled from 13 hospitals between July 2013 and June 2014. Mean operation time, degree of intraoperative bleeding and postoperative bleeding rate were evaluated.

Results

A total of 388 children (mean age ± standard deviation = 6.6 ± 2.5 years; 245 males and 143 females) were included. According to the adenoidectomy technique, the children were classified into 3 groups: (1) CA (n = 116); (2) PAA+C (n = 153); and (3) PAA-C (n = 119). Significant differences were not found in age and sex among three groups. In the CA group, mean operation time was significantly shorter (P < 0.001) and degree of intraoperative bleeding was significantly less (P < 0.001) compared to PAA+C or PAA-C group. Delayed postoperative bleeding rate of PAA-C group was significantly higher than that of CA or PAA+C group (P = 0.016).

Conclusions

This prospective multicenter study showed that CA was superior to PAA in terms of mean operation time and degree of intraoperative bleeding.     

Recovery of Corneal Endothelial Cells from Periphery after Injury

Background

Wound healing of the endothelium occurs through cell enlargement and migration. However, the peripheral corneal endothelium may act as a cell resource for the recovery of corneal endothelium in endothelial injury.

Aim

To investigate the recovery process of corneal endothelial cells (CECs) from corneal endothelial injury.

Methods

Three patients with unilateral chemical eye injuries, and 15 rabbit eyes with corneal endothelial chemical injuries were studied. Slit lamp examination, specular microscopy, and ultrasound pachymetry were performed immediately after chemical injury and 1, 3, 6, and 9 months later. The anterior chambers of eyes from New Zealand white rabbits were injected with 0.1 mL of 0.05 N NaOH for 10 min (NaOH group). Corneal edema was evaluated at day 1, 7, and 14. Vital staining was performed using alizarin red and trypan blue.

Results

Specular microscopy did not reveal any corneal endothelial cells immediately after injury. Corneal edema subsided from the periphery to the center, CEC density increased, and central corneal thickness decreased over time. In the animal study, corneal edema was greater in the NaOH group compared to the control at both day 1 and day 7. At day 1, no CECs were detected at the center and periphery of the corneas in the NaOH group. Two weeks after injury, small, hexagonal CECs were detected in peripheral cornea, while CECs in mid-periphery were large and non-hexagonal.

Conclusions

CECs migrated from the periphery to the center of the cornea after endothelial injury. The peripheral corneal endothelium may act as a cell resource for the recovery of corneal endothelium.     

Efficacy and Safety of Sorafenib Therapy on Metastatic Renal Cell Carcinoma in Korean Patients: Results from a Retrospective Multicenter Study

Objective

To evaluate the efficacy and safety of sorafenib for Korean patients with metastatic renal cell carcinoma (mRCC).

Methods

A total of 177 mRCC patients using sorafenib as first- (N = 116), second- (N = 43), and third-line (N = 18) therapies were enrolled from 11 Korean centers between 2006 and 2012. The patient characteristics, therapy duration, tumor response, disease control rate, and tolerability were assessed at baseline and at routine follow-ups, and the progression-free survival (PFS) and overall survival (OS) times and rates were analyzed.

Results

Among all patients, 18 (10.2%) stopped sorafenib treatment for a median of 1.7 weeks, including 15 (8.5%) who discontinued the drug, while 40 (22.6%) and 12 (6.8%) patients required dose reductions and drug interruptions, respectively. Severe adverse events (AEs) or poor compliance was observed in 64 (36.2%) patients, with 118 (7.4%) ≥grade 3 AEs. During the treatment, one myocardial infarction was observed. The number of ≥grade 3 AEs in the first-line sorafenib group was 71 (6.8% of the total 1048 AEs). During a median follow-up of 17.2 months, the radiologically confirmed best objective response rate, disease control rate, median PFS, and median OS were 22.0%, 53.0%, 6.4 months (95% confidence interval [CI], 5.2–8.9), and 32.6 months (95% CI, 27.3–63.8) for the total 177 sorafenib-treated patients, respectively, and 23.2%, 56.0%, 7.4 months (95% CI, 5.5–10.5), and not reached yet (95% CI, 1.0–31.1) for the first-line sorafenib group, respectively.

Conclusions

Sorafenib produced tolerable safety, with a ≥grade 3 AE rate of 7.4% and an acceptable disease control rate (53.0%) in Korean mRCC patients.     

The Inhibitory Effects of Low-Dose Ionizing Radiation in IgE-Mediated Allergic Responses

Ionizing radiation has different biological effects according to dose and dose rate. In particular, the biological effect of low-dose radiation is unclear. Low-dose whole-body gamma irradiation activates immune responses in several ways. However, the effects and mechanism of low-dose radiation on allergic responses remain poorly understood. Previously, we reported that low-dose ionizing radiation inhibits mediator release in IgE-mediated RBL-2H3 mast cell activation. In this study, to have any physiological relevance, we investigated whether low-dose radiation inhibits allergic responses in activated human mast cells (HMC-1(5C6) and LAD2 cells), mouse models of passive cutaneous anaphylaxis and the late-phase cutaneous response. High-dose radiation induced cell death, but low-dose ionizing radiation of <0.5 Gy did not induce mast cell death. Low-dose ionizing radiation that did not induce cell death significantly suppressed mediator release from human mast cells (HMC-1(5C6) and LAD2 cells) that were activated by antigen-antibody reaction. To determine the inhibitory mechanism of mediator released by low-dose ionizing radiation, we examined the phosphorylation of intracellular signaling molecules such as Lyn, Syk, phospholipase Cγ, and protein kinase C, as well as the intracellular free Ca²⁺ concentration ([Ca²⁺]_i). The phosphorylation of signaling molecules and [Ca²⁺]_i following stimulation of FcεRI receptors was inhibited by low dose ionizing radiation. In agreement with its in vitro effect, ionizing radiation also significantly inhibited inflammatory cells infiltration, cytokine mRNA expression (TNF-α, IL-4, IL-13), and symptoms of passive cutaneous anaphylaxis reaction and the late-phase cutaneous response in anti-dinitrophenyl IgE-sensitized mice. These results indicate that ionizing radiation inhibits both mast cell-mediated immediate- and delayed-type allergic reactions in vivo and in vitro.     

Cysteine-rich secretory protein 3 inhibits hepatitis C virus at the initial phase of infection

Hepatitis C virus (HCV) affects 2–3% of the global population. Approximately one-quarter of acute infections cause chronic hepatitis that leads to liver cirrhosis or hepatocellular carcinoma. The major obstacle of current research is the extremely narrow host tropism of HCV. A single HCV strain can replicate in the Huh7 human hepatoma cell line. Huh7 cells can be adapted under selective pressure in vitro to identify host factors that influence viral replication. Here, we extended this strategy to the in vivo condition and generated a series of cell lines by multiple rounds of adaptation in immunocompromised mice. Adaptation increased the cellular resistance to HCV infection. Microarray analyses revealed that the expression levels of several genes were associated with HCV resistance. Notably, up-regulation of the mRNA encoding cysteine-rich secretory protein 3 (CRISP3), a glycoprotein with unknown function that is secreted from multiple exocrine glands, was correlated with HCV resistance. The presence of CRISP3 in the culture medium limited HCV replication at the early phase of infection.     

8-Oxo-2′-deoxyguanosine ameliorates features of metabolic syndrome in obese mice

Metabolic syndrome describes a group of clinical features that together increase the incidence of coronary artery disease, stroke and type 2 diabetes. Insulin resistance is a major risk factor for developing metabolic syndrome. A chronic state of inflammation accompanies the accumulation of surplus lipids in adipose and liver tissue, frequently involved in insulin resistance. 8-Oxo-2′-deoxyguanosine (8-Oxo-dG) is a potent anti-inflammatory agent that inactivates both Rac1 and Rac2 which are critical to initiating the inflammatory responses in various cell types, including macrophages. In this study, we explored whether 8-Oxo-dG suppressed a series of systemic inflammatory cascades, resulting in the amelioration of typical features of metabolic syndrome in obese mice. The results demonstrate that 8-Oxo-dG effectively improved hyperglycemia, dyslipidemia and fatty liver changes in obese mice. The level of biochemical markers indicative of systemic inflammation were reduced in 8-Oxo-dG treated mice, whereas serum levels of adiponectin, a crucial factor associated with improved metabolic syndrome, were enhanced. Our results demonstrate that 8-Oxo-dG effectively disrupts the pathogenesis of insulin resistance and obesity-associated metabolic syndrome.     

Inhibition of HAS2 induction enhances the radiosensitivity of cancer cells via persistent DNA damage

Hyaluronan synthase 2 (HAS2), a synthetic enzyme for hyaluronan, regulates various aspects of cancer progression, including migration, invasion and angiogenesis. However, the possible association of HAS2 with the response of cancer cells to anticancer radiotherapy, has not yet been elucidated. Here, we show that HAS2 knockdown potentiates irradiation-induced DNA damage and apoptosis in cancer cells. Upon exposure to radiation, all of the tested human cancer cell lines exhibited marked (up to 10-fold) up-regulation of HAS2 within 24 h. Inhibition of HAS2 induction significantly reduced the survival of irradiated radioresistant and -sensitive cells. Interestingly, HAS2 depletion rendered the cells to sustain irradiation-induced DNA damage, thereby leading to an increase of apoptotic death. These findings indicate that HAS2 knockdown sensitizes cancer cells to radiation via persistent DNA damage, further suggesting that the irradiation-induced up-regulation of HAS2 contributes to the radioresistance of cancer cells. Thus, HAS2 could potentially be targeted for therapeutic interventions aimed at radiosensitizing cancer cells.     

HDAC6 controls autophagosome maturation essential for ubiquitin‐selective quality‐control autophagy

Autophagy is primarily considered a non‐selective degradation process induced by starvation. Nutrient‐independent basal autophagy, in contrast, imposes intracellular QC by selective disposal of aberrant protein aggregates and damaged organelles, a process critical for suppressing neurodegenerative diseases. The molecular mechanism that distinguishes these two fundamental autophagic responses, however, remains mysterious. Here, we identify the ubiquitin‐binding deacetylase, histone deacetylase‐6 (HDAC6), as a central component of basal autophagy that targets protein aggregates and damaged mitochondria. Surprisingly, HDAC6 is not required for autophagy activation; rather, it controls the fusion of autophagosomes to lysosomes. HDAC6 promotes autophagy by recruiting a cortactin‐dependent, actin‐remodelling machinery, which in turn assembles an F‐actin network that stimulates autophagosome–lysosome fusion and substrate degradation. Indeed, HDAC6 deficiency leads to autophagosome maturation failure, protein aggregate build‐up, and neurodegeneration. Remarkably, HDAC6 and F‐actin assembly are completely dispensable for starvation‐induced autophagy, uncovering the fundamental difference of these autophagic modes. Our study identifies HDAC6 and the actin cytoskeleton as critical components that define QC autophagy and uncovers a novel regulation of autophagy at the level of autophagosome–lysosome fusion.