Potential redox-sensitive Akt activation by dopamine activates Bad and promotes cell death in melanocytes

Dopamine (DA) is a well known oxidative neurotoxin. In addition, Akt has been reported to deliver a survival signal that inhibits apoptosis. However, it has also been reported that chronic Akt activation leads to apoptosis in response to oxidative stress. The objective of the present study was to investigate the possible role of the Akt pathway in vitiligo and its possible relationship with DA-induced cell death using Mel-Ab cells. Cultured Mel-Ab cells were treated with DA with and without N-Acetyl-L-cysteine (NAC), which is known to have antioxidative properties. Cell viability was then assessed by a crystal violet assay and Annexin staining was performed. The changes in the expression of Akt were analyzed by western blot analysis. The cell viability was reduced by approximately 60% in response to treatment with 500 µM DA, and NAC effectively prevented this cytotoxic effect. Likewise, treatment with DA produced numerous Annexin positive cells, while treatment with NAC prevented this apoptotic cell death. Akt was slowly phosphorylated after treatment with DA, while NAC clearly inhibited the DA-induced Akt activation. Western blot analysis also showed that treatment with DA induced the activation of Bad. Finally, LY294002 exerted a protective effect against DA-induced apoptotic cell death. DA may induce redox-sensitive Akt activation and increase the level of Bad, which can promote cell death by heterodimerization with survival proteins. Moreover, NAC effectively protects against DA-induced melanocyte death via inhibition of DA-induced Akt activation

Robot-assisted posterior retroperitoneoscopic adrenalectomy: single port access

Laparoscopic adrenalectomy has become a gold standard in adrenal gland surgery. More recently, some minimally invasive trials have been conducted on single access surgery on the adrenal gland. In this study, we introduce our first experiences of robot-assisted posterior retroperitoneoscopic adrenalectomy using single-port access and the da Vinci system

Tailored growth of graphene oxide liquid crystals with controlled polymer crystallization in GO-polymer composites

Graphene Oxides (GOs) have been frequently employed as fillers in polymer-based applications. While GO is known to nucleate polymer crystallization in GO-polymer composites reinforcing the mechanical properties of semicrystalline polymers, its counter effect on how polymer crystallization can alter the microstructure of GO has rarely been systematically studied yet. In this work, we study the GO nematic liquid crystal (LC) phase during polymer crystallization focusing on their hierarchical structures by employing in situ small/wide-angle X-ray scattering/diffraction (SAXS/WAXD) techniques. We found that GO LC and polymer crystals co-exist in the GO/polymer complex, where the overall liquid crystallinity is influenced by polymer crystallization. While polymer crystallizes in bulk or at the interface depending on the cooling rate, the interfacial crystallization of poly(ethylene glycol) (PEG) on GO improves both GO alignment and orientation of PEG crystal. This work provides an opportunity to develop a hierarchical structure of GO-based crystalline polymer nanocomposites, whose directionality can be controlled by polymer crystallization under proper cooling rates

Relationship between recurrence and age in the diffuse sclerosing variant of papillary thyroid carcinoma: clinical significance in pediatric patients

BackgroundThe diffuse sclerosing variant (DSV) is among the aggressive variants of papillary thyroid carcinoma (PTC) and is more prevalent in pediatric patients than in adult patients. Few studies have assessed its characteristics owing to its low incidence. We aimed to evaluate the relationship between recurrence and age in the DSV of PTC.MethodsWe retrospectively reviewed patients diagnosed with the DSV or conventional PTC (cPTC) after surgery at a medical center between May 1988 and January 2019. We compared the clinico-pathological characteristics and surgical outcomes of the DSV and cPTC groups and between adult and pediatric patients with DSV.ResultsAmong the 24,626 patients, 202 had the DSV, and 24,424 were diagnosed with cPTC. The recurrence rate was significantly higher in the DSV group than in the cPTC group. In the DSV group, the recurrence rate was significantly higher in the pediatric patient group than in the adult patient group. Moreover, the association between recurrence and age group showed different patterns between the DSV and cPTC groups with restricted cubic splines (RCS). While both RCS curves showed a U-shaped distribution, the RCS curve tended to be located within the younger age group.ConclusionsThis study demonstrated that pediatric patients with DSV are at a greater risk for recurrence compared with adult patients; moreover, the pattern of recurrence risk according to age is different from that of cPTC

Role of age and sex in determining antibiotic resistance in febrile urinary tract infections

SummaryObjectivesTo identify the age- and sex-specific antimicrobial susceptibility patterns of Gram-negative bacteria (GNB) in outpatient febrile urinary tract infections (UTIs) in Korea.MethodsA total 2262 consecutive samples collected from patients aged 1–101 years with febrile UTIs, during the period January 2012 to December 2014, were analyzed in this multicentre, retrospective cohort study.ResultsThe sensitivities to cefotaxime and cefoxitin were over 85% for females but under 75% for males. Sex played an important role in the susceptibility of GNB to cefotaxime (p<0.001) and cefoxitin (p<0.001). The sensitivity to ciprofloxacin (age >20 years) was under 75% in both sexes, and was not influenced by sex (p=0.204). Age distributions of the incidences of resistance to cefotaxime, cefoxitin, and ciprofloxacin (age >20 years) were similar to the age distribution of the incidence of GNB, which indicates that the resistance patterns to these drugs were not affected by age (Kolmogorov–Smirnov test, female/male: p=0.927/p=0.509, p=0.193/p=0.911, and p=0.077/p=0.999, respectively).ConclusionsAge is not a considerable factor in determining the antibiotic resistance in febrile UTIs. Ciprofloxacin should be withheld from both sexes until culture results indicate its use. Second- or third-generation cephalosporins such as cefoxitin and cefotaxime can be used empirically only in females

Do large thyroid nodules (≥4 cm) without suspicious cytology need surgery?

BackgroundFine-needle aspiration biopsy (FNAB) is a good diagnostic tool for thyroid nodules; however, its high false-negative rate for giant nodules remains controversial. Many clinicians recommend surgical resection for nodules &gt;4 cm owing to an increased risk of malignancy and an increased false-negative rate. This study aimed to examine the feasibility of this approach and investigate the incidence of malignancy in thyroid nodules &gt;4 cm without suspicious cytology based on medical records in our center.MethodsThis was a retrospective analysis of 453 patients that underwent preoperative FNAB for nodules measuring &gt;4 cm between January 2017 and August 2022 at Severance Hospital, Seoul.ResultsAmong the 453 patients, 140 nodules were benign and 119 were indeterminate. Among 259 patients, the final pathology results were divided into benign (149) and cancerous (110) groups, and the prevalence of malignancy was 38.9% in the benign group and 55.5% in the indeterminate group. Among the malignancies, follicular carcinoma and follicular variants of papillary carcinoma were observed in 83% of the cytologically benign group and 62.8% of the indeterminate group.ConclusionPreoperative FNAB had high false-negative rates and low diagnostic accuracy in patients with thyroid nodules &gt;4 cm without suspicious cytologic features; therefore, diagnostic surgery may be considered a treatment option

Postoperative Complications of Thyroid Cancer in a Single Center Experience

The aim of this study was to investigate the complications following surgical treatment of thyroid cancer and the association between the extent of surgery and complication rates. A total of 2,636 patients who underwent surgery due to thyroid cancer were retrospectively reviewed to identify surgical complications. Complication rates were assessed according to the extent of surgery, which was classified as follows; less-than-total thyroidectomy with central compartment node dissection (CCND) (Group I, n=636), total thyroidectomy with CCND (Group II, n=1,390), total thyroidectomy plus ipsilateral neck dissection (Group III, n=513), and total thyroidectomy plus bilateral neck dissection (Group IV, n=97). The most common surgical complication was symptomatic hypoparathyroidism, of which 28.4% of cases were transient and 0.3% permanent. The other surgical complications included vocal cord palsy (0.7% transient, and 0.2% permanent), hematoma (0.5%), seroma (4.7%), chyle fistula (1.8%), and Horner's syndrome (0.2%). The complication rates increased significantly with increasing the extent of surgery from Group I to Group IV. The more extensive surgery makes more complications, such as hypoparathyroidism, seroma, and others