• Bulletin of the Korean Chemical Society
• /
• v.34 no.10
• /
• pp.2983-2988
• /
• 2013

Second-order rate constants ($k_N$) have been measured spectrophotometrically for the reactions of 4-chloro-2-nitrophenyl X-substituted-benzoates (1a-1h) with a series of cyclic secondary amines in 80 mol % $H_2O$/20 mol % DMSO at $25.0{\pm}0.1^{\circ}C$. The Hammett plot for the reactions of 1a-1h with piperidine consists of two intersecting straight lines, while the Yukawa-Tsuno plot exhibits an excellent linear correlation with ${\rho}_X $ = 1.25 and r = 0.58, indicating that the nonlinear Hammett plot is not due to a change in the rate-determining step (RDS) but is caused by ground-state stabilization through resonance interactions for substrates possessing an electron-withdrawing group in the benzoyl moiety. The Br${\o}$nsted-type plot for the reactions of 4-chloro-2-nitrophenyl benzoate (1d) with a series of cyclic secondary amines curves downward with ${\beta}_2$ = 0.85, ${\beta}_1$ = 0.24, and $pK_a{^o}$ = 10.5, implying that a change in RDS occurs from the $k_2$ step to the $k_1$ process as the $pK_a$ of the conjugate acid of the amine exceeds 10.5. Dissection of $k_N$ into the microscopic rate constants $k_1$ and $k_2/k_{-1}$ ratio associated with the reaction of 1d reveals that $k_2$ is dependent on the amine basicity, which is contrary to generally held views.

• Korean Journal of Clinical Oncology
• /
• v.14 no.2
• /
• pp.135-141
• /
• 2018

Purpose: Axillary lymph node dissection (ALND) and sentinel lymph node biopsy (SLNB) are important for staging of patients with node-positive breast cancer. However, these can be avoided in select micrometastatic diseases, preventing postoperative complications. The present study evaluated the ability of axillary lymph node maximum standardized uptake value (SUVmax) on positron emission tomography-computed tomography (PET-CT) to predict axillary metastasis of breast cancer. Methods: The records of invasive breast cancer patients who underwent pretreatment (surgery and/or chemotherapy) PET-CT between January 2006 and December 2014 were reviewed. ALNs were preoperatively evaluated by PET-CT. Lymph nodes were dissected by SLNB or ALND. SUVmax was measured in both the axillary lymph node and primary tumor. Student t-test and chi-square test were used to analyze sensitivity and specificity. Receiver operating characteristic (ROC) and area under the ROC curve (AUC) analyses were performed. Results: SUV-tumor (SUV-T) and SUV-lymph node (SUV-LN) were significantly higher in the triple-negative breast cancer (TNBC) group than in other groups (SUV-T: 5.99, P<0.01; SUV-LN: 1.29, P=0.014). The sensitivity (0.881) and accuracy (0.804) for initial ALN staging were higher in fine needle aspiration+PET-CT than in other methods. For PET-CT alone, the subtype with the highest sensitivity (0.870) and negative predictive value (0.917) was TNBC. The AUC for SUV-LN was greatest in TNBC (0.797). Conclusion: The characteristics of SUV-T and SUV-LN differed according to immunohistochemistry subtype. Compared to other subtypes, the true positivity of axillary metastasis on PET-CT was highest in TNBC. These findings could help tailor management for therapeutic and diagnostic purposes.

• Archives of Craniofacial Surgery
• /
• v.24 no.1
• /
• pp.10-17
• /
• 2023

Background: Lipomas are common benign tumors of mesenchymal origin that are composed of mature adipocytes. Giant lipomas have a diameter ≥ 10 cm in one or more dimensions or weigh at least 1,000 g. The surgical excision of a giant lipoma requires extensive dissection, increasing the risk of a seroma, which can cause surgical site complications such as wound infection and necrosis. Sclerotherapy with Abnobaviscum (Viscum album extract) is a relatively new technique used to reduce malignant pleural effusion. In this study, we evaluated the effectiveness of prophylactic sclerotherapy using Abnobaviscum to decrease seroma after giant lipoma excision. Methods: We conducted a retrospective medical record review of patients who underwent surgical excision for giant lipoma of the neck from January 2019 to December 2022. Sclerotherapy was performed on the first postoperative day in patients who consented to the procedure, and Abnobaviscum was instilled through the existing Hemovac drain. We compared the clinical course between those who underwent postoperative sclerotherapy and those who did not. Results: Among the 30 patients who underwent giant lipoma excision, we applied sclerotherapy with Abnobaviscum to 15 patients. The average time from surgery to Hemovac removal was statistically shorter in patients who underwent sclerotherapy (p= 0.004). Furthermore, seroma formation was significantly reduced in patients receiving sclerotherapy (p= 0.003). Conclusion: In patients undergoing giant lipoma excision, sclerotherapy using Abnobaviscum helps reduce postoperative seroma formation during the initial postoperative period. It can be an excellent method to reduce complications related to seroma and attenuate patients' postoperative burden.

• Journal of Gastric Cancer
• /
• v.23 no.4
• /
• pp.598-608
• /
• 2023

Purpose: Lymph node (LN) metastasis is a crucial factor in the prognosis of patients with gastric cancer (GC) and is known to occur more frequently in cases with an advanced T stage. This study aimed to analyze the survival data of patients with advanced LN metastasis in T1 GC. Materials and Methods: From January 2008 to June 2018, 677 patients with pathological stage II GC who underwent radical gastrectomy were divided into an early GC group (EG: T1N2 and T1N3a, n=103) and an advanced GC (AGC) group (AG: T2N1, T2N2, T3N0, T3N1, and T4aN0, n=574). Short- and long-term survival rates were compared between the 2 groups. Results: A total of 80.6% (n=83) of the patients in the EG group and 52.8% (n=303) in the AG group had stage IIA AGC. The extent of LN dissection, number of retrieved LNs, and short-term morbidity and mortality rates did not differ between the 2 groups. The 5-year relapse-free survival (RFS) of all patients was 87.8% and the overall survival was 84.0%. RFS was lower in the EG group than in the AG group (82.2% vs. 88.7%, P=0.047). This difference was more pronounced among patients with stage IIA (82.4% vs. 92.9%, P=0.003). Conclusions: T1 GC with multiple LN metastases seems to have a worse prognosis compared to tumors with higher T-stages at the same level. Adjuvant chemotherapy is highly recommended for these patients, and future staging systems may require upstaging T1N2-stage tumors.

• Korean Journal of Radiology
• /
• v.20 no.8
• /
• pp.1266-1274
• /
• 2019

Objective: To determine whether radiologic extranodal extension (ENE) appearing on pretreatment CT and MRI could predict the prognosis in patients with human papillomavirus (HPV)-related oropharyngeal squamous cell carcinoma (OPSCC). Materials and Methods: The study population was obtained from a historical cohort diagnosed with HPV-related OPSCC. A total of 134 OPSCC patients who had a metastatic lymph node on pretreatment CT or MRI were included, and radiologic ENE was evaluated by two experienced head and neck radiologists. Kaplan-Meier and multivariate Cox regression analyses were performed to evaluate the impact of radiologic ENE on progression-free survival (PFS). The diagnostic performance of CT and MRI for the diagnosis of ENE was also evaluated in patients who underwent neck dissection. Results: Seventy patients (52.2%) showed radiologic ENE-positive findings. Although patients showing radiologic ENE had a worse 3-year PFS (83.7% vs. 95.3%, p = 0.023), the association between radiologic ENE and PFS was not statistically significant on multivariate analysis (p = 0.141; hazard ratio, 2.68; 95% confidence interval, 0.72-9.97). CT or MRI had a sensitivity of 62%, specificity of 77.8%, and accuracy of 71.9% for predicting pathologic ENE. Conclusion: Radiologic ENE on CT or MRI did not predict poor PFS in patients with HPV-related OPSCC, although there was a trend towards worse PFS. Further studies are warranted to determine whether radiologic ENE is a useful imaging biomarker to risk-stratify patients with HPV-related OPSCC.

• Archives of Plastic Surgery
• /
• v.50 no.6
• /
• pp.601-609
• /
• 2023

Background The anterolateral thigh (ALT) flap is a preferred option in the reconstruction of a wide variety of defects, enabling multiple tissue components and thicknesses. Methods This study was conducted to investigate the correlation of the thickness of the traditional subfascial ALT flap and superficial fat flap with age, gender, and body mass index (BMI). A total of 42 patients (28 males and 14 females) were included in the study. Results Mean age was 50.2 (range, 16-75) years and mean BMI was 24.68 ± 4.02 (range, 16.5-34.7) kg/m². The subfascial flap thickness was significantly thinner in male patients (16.07 ± 2.77 mm) than in female patients (24.07 ± 3.93 mm; p < 0.05), whereas no significant difference was found between male (4.28 ± 1.15 mm) and female patients (4.85 ± 1.09 mm) regarding superficial fat flap thickness (p = 0.13). The thickness of both flaps had a positive correlation with BMI, and the strongest correlation was found for subfascial ALT thickness in female patients (r = 0.81). Age had no effect on both flap thickness measurements. The anterior thigh is thicker in women than in men, although it varies according to BMI. This shows that flap elevation is important in the superthin plane, especially if a thin flap is desired in female patients in defect reconstruction with the ALT flap. Thus, a single-stage reconstruction is achieved without the need for a defatting procedure after subfascial dissection or a second defatting procedure 3 to 6 months later. Conclusion The appropriate ALT flap plane should be selected considering the gender and BMI of the patient.

• Clinical Endoscopy
• /
• v.55 no.4
• /
• pp.525-531
• /
• 2022

Background/Aims: Endoscopic wound suturing is an important factor that affects the ability to remove large and full-thickness lesions during endoscopic resection. We aimed to evaluate the effect of a traction metal clip with a fishhook-like device on wound sutures after endoscopic resection. Methods: From July 2020 to April 2021, patients who met the enrollment criteria were treated with a fishhook-like device during the operation to suture the postoperative wound (group A). Patients with similar conditions and similar size wounds who were treated with a "purse-string suture" to suture the wounds were retrospectively analyzed as the control group (group B). Difference in the suture rate, adverse events, time required for suturing, and number of metal clips were compared between the two groups. Results: The time required for suturing was 7.72±0.51 minutes in group A and 11.50±0.91 minutes in group B. This difference was statistically significant (F=13.071, p=0.001). The number of metal clamps used in group A averaged 8.1 pieces/case, and the number of metal clamps used in group B averaged 7.3 pieces/case. This difference was not statistically significant (F=0.971, p=0.331). Conclusions: The traction metal clip with the fishhook-like device is ingeniously designed and easy to operate. It has a good suture effect on the wound after endoscopic submucosal dissection and effectively prevents postoperative adverse events.

• Annals of Hepato-Biliary-Pancreatic Surgery
• /
• v.26 no.2
• /
• pp.190-198
• /
• 2022

Backgrounds/Aims: Traumatic pancreatic injury (TPI) is rare as an isolated injury. There is a trend to perform conservative treatment even in patients with complete duct dissection and successful treatment. This study reviewed our 20 years of experience in the management of TPI and assessed patient outcomes according to age group and treatment strategy. Methods: A retrospective analysis of patients diagnosed and treated with TPI at a level-I trauma center from 2000-2019. Patients were divided into two groups: adults and pediatrics. Conservative treatment cases were subjected to subgroup analysis. Level of evidence: IV. Results: Of a total of 77 patients, the mean age was 24.89 ± 15.88 years. Fifty-six (72.7%) patients had blunt trauma with motor vehicle accident. Blunt trauma was the predominant mechanism in 42 (54.5%) patients. Overall, 38 (49.4%) cases had grade I or II injury, 24 (31.2%) had grade III injury, and 15 (19.5%) had grade IV injury. A total of 30 cases had non-operative management (NOM). Successful NOM was observed in 16 (20.8%) cases, including eight (32.0%) pediatric cases and eight (15.4%) adult cases. Higher American association for the surgery of trauma (AAST) grade of injury was associated with NOM failure (16.7% for grade I/II, 100% for grade III, and 66.7% for grade IV injury; p = 0.001). An independent factor for NOM failure was female sex (69.2% in females vs. 29.4% in males; p = 0.03). Conclusions: High AAST grade TPI is associated with a high rate of NOM failure in both pediatric and adults.

• Journal of Cerebrovascular and Endovascular Neurosurgery
• /
• v.25 no.4
• /
• pp.468-472
• /
• 2023

Bilateral posterior communicating (pComm) artery aneurysms represent only 2% of mirror intracranial aneurysms. Usually, these are surgically approached through bilateral craniotomies for clipping. We present the case of a 50-year-old female presenting with headache and horizontal diplopia. Neurological examination revealed a left oculomotor palsy, with no other neurological deficits. Imaging studies revealed bilateral aneurysmatic lesions in both internal carotid arteries (ICA). A conventional left pterional approach was planned in order to treat the symptomatic aneurysm, and, if deemed feasible, a contralateral clipping through the same approach. The procedure was performed in a hybrid operating room (HOR), performing an intraoperative digital subtraction angiography (DSA) and roadmapping assistance during dissection and clipping. Transoperatively, a post-fixed optic chiasm was identified, with a wide interoptic space, which allowed us to perform the contralateral clipping through a unilateral approach. This technique for clipping bilateral pComm aneurysms can be performed when the proper anatomical features are met.

• Journal of Cerebrovascular and Endovascular Neurosurgery
• /
• v.26 no.2
• /
• pp.216-222
• /
• 2024

Dissecting posterior inferior cerebellar artery (PICA) aneurysms are uncommon lesions. Their anatomy and the location of the dissection are variable, however, they usually occurs at the origin of the PICA. Dissecting PICA aneurysms generally have non-vascular morphology involving an entire segment of the artery and cannot be cut. Nevertheless, the detection of these vascular lesions has increased latterly, so it is necessary to recognize it and take the appropriate management modalities for these injuries. In this report, we describe a case of a 73-year-old male patient, who presented a history of severe headache, associated with neck stiffness, nausea, vomiting, dizziness, hypoactivity, mental confusion, and walking difficulty. Radiographic investigation with brain computed tomography (CT) showed mild bleeding in a pre-medullary and pre-pontine cistern, and cerebral angiogram showed a dissecting PICA aneurysm. Despite being a challenging treatment, microsurgery management was the chosen modality. It was performed an end-to-end anastomosis between the p2/p3 segments, showing to be effective with good clinical and radiographic outcomes. We discussed an unusual case, reviewing the current literature on clinical presentations, the angiographic characteristics of the dissecting aneurysms of PICA, and evaluating the clinical and angiographic results of patients undergoing microsurgical treatment.