Purpose: This study investigated the causative microorganisms, antibiotic susceptibility, and risk factors of infectious keratitis over the past 10 years. Methods: Data from patients with infectious keratitis who underwent microbial culture tests from 2012 to 2021, obtained from anonymized data systems, were analyzed. Microbial culture results and antibiotic susceptibility profiles were examined. A retrospective analysis of the medical records of patients with infectious keratitis during the same period was conducted to investigate the clinical characteristics and risk factors. Results: Data from 1,837 cases of infectious keratitis were extracted from anonymized records. The culture positive rate among patients was 46.0% (1,137/2,474), with coagulase-negative Staphylococcus (CoNS) being the most common causative organism (27.8%). Increased resistance to cefazolin and cefotaxime was observed in gram-negative bacteria, while there were no significant temporal changes in quinolone resistance in gram-positive or negative bacteria. A retrospective medical record analysis of 288 cases revealed that older patients, as well as those with an initial corrected visual acuity < 0.1, a history of ocular surgery, pre-existing ocular conditions, prior steroid eye drops, or glaucoma eye drops, had significantly higher rates of culture positivity. Multivariate analysis identified risk factors for severe keratitis requiring surgical intervention as a symptom-to-presentation period of 7 days or longer (p = 0.048) and pre-existing ocular conditions (p = 0.040). Conclusions CoNS was the most common microorganism causing infectious keratitis over the past decade. There has been an increase in resistance to cephalosporin antibiotics among gram-negative bacteria. Patients with pre-existing ocular conditions may require surgical intervention, so infectious keratitis in these patients requires greater attention.

Objective: Geriatric patients requiring gynecological surgery is increasing worldwide. However, older patients are at higher risk of postoperative morbidity and mortality, particularly cardiopulmonary complications. Laparoscopic surgery is widely used as a minimally invasive method for reducing postoperative morbidities. We compared the outcomes of open and laparoscopic gynecologic surgeries in patients older than 55 years. Methods: We included patients aged >55 years who underwent gynecological surgery at a single tertiary center between 2010 and 2020, excluding vaginal or ovarian cancer surgeries were excluded. Surgical outcomes were compared between the open surgery and laparoscopic groups, with age cutoff was set at 65 years for optimal discriminative power. We performed linear or logistic regression analyses to compare the surgical outcomes according to age and operation type. Results: Among 2,983 patients, 28.6% underwent open surgery and 71.4% underwent laparoscopic surgery. Perioperative outcomes of laparoscopic surgery were better than those of open surgery in all groups. In both the open and laparoscopic surgery groups, the older patients showed worse overall surgical outcomes. However, age-related differences in perioperative outcomes were less severe in the laparoscopic group. In the linear regression analysis, the differences in estimated blood loss, transfusion, and hospital stay between the age groups were smaller in the laparoscopy group. Similar results were observed in cancer-only and benign-only cohorts. Conclusion Although the surgical outcomes were worse in the older patients, the difference between age groups was smaller for laparoscopic surgery. Laparoscopic surgery offers more advantages and safety in patients aged >65 years.

Purpose: Despite scientific evidence regarding laparoscopic gastrectomy (LG) for advanced gastric cancer treatment, its application in patients receiving neoadjuvant chemotherapy remains uncertain. Materials and Methods: We used the 2019 Korean Gastric Cancer Association nationwide survey database to extract data from 489 patients with primary gastric cancer who received neoadjuvant chemotherapy. After propensity score matching analysis, we compared the surgical outcomes of 97 patients who underwent LG and 97 patients who underwent open gastrectomy (OG). We investigated the risk factors for postoperative complications using multivariate analysis. Results: The operative time was significantly shorter in the OG group. Patients in the LG group had significantly less blood loss than those in the OG group. Hospital stay and overall postoperative complications were similar between the two groups. The incidence of Clavien– Dindo grade ≥3 complications in the LG group was comparable with that in the OG group (1.03% vs. 4.12%, P=0.215). No statistically significant difference was observed in the number of harvested lymph nodes between the two groups (38.60 vs. 35.79, P=0.182). Multivariate analysis identified body mass index (odds ratio [OR], 1.824; 95% confidence interval [CI], 1.029–3.234; P=0.040) and extent of resection (OR, 3.154; 95% CI, 1.084–9.174; P=0.035) as independent risk factors for overall postoperative complications. Conclusions Using a large nationwide multicenter survey database, we demonstrated that LG and OG had comparable short-term outcomes in patients with gastric cancer who received neoadjuvant chemotherapy.

Background: and PurposeWe aimed to determine the effect of demographic factors on cortical thickness and brain glucose metabolism in healthy aging subjects. Methods: The following tests were performed on 71 subjects with normal cognition: neurological examination, 3-tesla magnetic resonance imaging, 18F-fluorodeoxyglucose positron-emission tomography, and neuropsychological tests. Cortical thickness and brain metabolism were measured using vertex- and voxelwise analyses, respectively. General linear models (GLMs) were used to determine the effects of age, sex, and education on cortical thickness and brain glucose metabolism. The effects of mean lobar cortical thickness and mean lobar metabolism on neuropsychological test scores were evaluated using GLMs after controlling for age, sex, and education. The intracranial volume (ICV) was further included as a predictor or covariate for the cortical thickness analyses. Results: Age was negatively correlated with the mean cortical thickness in all lobes (frontal and parietal lobes, p=0.001; temporal and occipital lobes, p<0.001) and with the mean temporal metabolism (p=0.005). Education was not associated with cortical thickness or brain metabolism in any lobe. Male subjects had a lower mean parietal metabolism than did female subjects (p<0.001), while their mean cortical thicknesses were comparable. ICV was positively correlated with mean cortical thickness in the frontal (p=0.016), temporal (p=0.009), and occipital (p=0.007) lobes. The mean lobar cortical thickness was not associated with cognition scores, while the mean temporal metabolism was positively correlated with verbal memory test scores. Conclusions Age and sex affect cortical thickness and brain glucose metabolism in different ways. Demographic factors must therefore be considered in analyses of cortical thickness and brain metabolism.

Purpose: To introduce an intuitive method for measuring conjunctival microvascular blood flow velocity by imaging bulbar conjunctival microvessels using a slit-lamp biomicroscope equipped with a zoom lens and an ultra-high-speed camera. Methods: After obtaining consent from 10 patients (1 male, 9 females) who visited Yeouido St. Mary’s Hospital from August 21, 2020, to June 12, 2021, the patients were examined under a slit lamp microscope equipped with an ultra-high-speed camera and zoom lens. The blood flow in the conjunctival microvessels was photographed. The captured images were analyzed with ImageJ software to measure the blood flow velocity in the conjunctival microvessels, and we investigated whether the blood flow velocity correlated with the vessel diameter and age. Results: The median age of the subjects was 49.0 years. The mean conjunctival blood flow velocity in 53 microvessels was 0.786 ± 0.468 mm/s. The median conjunctival microvascular diameter was 7.06 μm (interquartile range 5.84 to 9.23 μm). The conjunctival microvascular diameter and blood flow velocity were not significantly correlated (Spearman’s p = 0.177), and the subjects’ age and conjunctival microvascular blood flow velocity were also not correlated (Spearman’s p = 0.669). Conclusions In this study, the blood flow velocity in the bulbar conjunctival microvessels could be measured easily by means of image analysis using a slit-lamp microscope equipped with an ultra-high-speed camera with a zoom lens.

Tolvaptan reduces height-adjusted total kidney volume (htTKV) and renal function decline in autosomal dominant polycystic kidney disease (ADPKD). This study was aimed at investigating the efficacy and safety of tolvaptan in Korean patients with ADPKD during the titration period. Methods: This study is a multicenter, single-arm, open-label phase 4 study. We enrolled 108 patients with ADPKD (age, 19–50 years) with an estimated glomerular filtration rate (eGFR) of >30 mL/min/1.73 m2 and factors defined as indicative of rapid disease progression. After tolvaptan titration, we evaluated efficacy and side effects and assessed factors associated with the effects. Results: After titration for 4 weeks, eGFR and htTKV decreased by 6.4 ± 7.9 mL/min/1.73 m2 and 16 ± 45 mL/m, respectively. No serious adverse drug reactions were observed during the titration period. The greatest eGFR decline was observed in the first week, with a starting tolvaptan dose of 45 mg. Multivariate linear regression for htTKV decline showed that the greater the change in urine osmolality (Uosm), the greater the decrease in htTKV (β, 0.436; p = 0.009) in the 1D group stratified by the Mayo Clinic image classification. Higher baseline eGFR was related to a higher htTKV reduction rate in the 1E group (β, –0.642; p = 0.009). Conclusion: We observed short-term effects and safety during the tolvaptan titration period. The decline of htTKV can be predicted as a short-term effect of tolvaptan by observing Uosm changes from baseline to end of titration in 1D and baseline eGFR in 1E groups.

Objective: To evaluate the landscape of gene alterations and immunohistochemistry (IHC) profiles of patients with ovarian cancer for targeted therapy and investigate the real-world experience of applying precision medicine. Methods: Patients diagnosed with ovarian cancer between January 2015 and May 2021 at Severance Hospital and who underwent tumor next-generation sequencing (NGS) were reviewed. Data on germline mutation, IHC markers for mismatch repair deficiency (MMRd), programmed death ligand 1 (PD-L1) expression, and human epidermal growth factor receptor 2 (HER2) expression were acquired. The use of matched therapy and its clinical outcomes were evaluated. Results: Of the 512 patients who underwent tumor NGS, 403 underwent panel-based germline testing. In patients who underwent both tests, tumor NGS identified 39 patients (9.7%) with BRCA mutations and 16 patients (4.0%) with other homologous recombination repair (HRR)-associated gene mutations, which were not found in germline testing. The most common single nucleotide variants were TP53 (82.2%), ARID1A (10.4%), PIK3CA (9.7%), and KRAS (8.4%). Copy number aberrations were found in 122 patients. MMRd was found in 3.2% of patients, high PD-L1 expression in 10.1%, and HER2 overexpression in 6.5%. Subsequently, 75 patients (14.6%) received a poly (ADP-ribose) polymerase inhibitor based on BRCA mutation and 11 patients (2.1%) based on other HRR-associated gene mutations. Six patients (1.2%) with MMRd underwent immunotherapy. Twenty-eight patients (5.5%) received other matched therapies targeting HER2, fibroblast growth factor receptor, folate receptor alpha, RAS, and PIK3CA. Conclusion A comprehensive review of germline mutation, IHC, and tumor NGS helped identify candidates for precision therapy in patients with ovarian cancer, a proportion of whom received matched therapy.

Purpose: After bariatric surgery, postoperative follow-up is important for evaluating longterm outcomes, such as successful weight loss and improvement of metabolic parameters.However, many patients are lost to follow-up within 1 year. This study aimed to identify the follow-up rate of bariatric surgery and predictive factors of loss to follow-up (LTF). Materials and Methods: We retrospectively reviewed the data of 61 patients receiving bariatric surgery for obesity (laparoscopic sleeve gastrectomy; LSG group) and 872 for early gastric cancer (EGC group) from November 2018 to July 2020 in a single center. After 1:1 matching, we compared the LTF rate. In the LSG group, we analyzed the factors associated with LTF. Additionally, we collected weight data in the LTF group by a telephone survey. Results: By 1:1 matching, 47 patients for each group were identified. The LTF rates of the LSG and EGC groups were 34.0% (16 patients) and 2.1% (one patient), respectively (P=0.0003).In the LSG group, the LTF rate increased over the postoperative month. Of the patients, 29.5% who missed a scheduled appointment within one year comprised the LTF group. In the analysis, no significant factors associated with LTF were identified. The only factor with borderline significance was dyslipidemia with medication (P=0.094). Conclusion The LSG group demonstrated a high LTF rate, although adherence to followup was closely related to postoperative outcomes. Therefore, educating patients on the significance of follow-up is important. Particularly, continuous efforts to identify the associated factors and develop a multidisciplinary management protocol after bariatric surgery are necessary.

In 2023, an 81-year-old woman requested a preliminary red blood cell transfusion during pancreatic cancer surgery, and antibody screening was performed using automated blood typing equipment. The antibody screening test results were negative when plasma was used as the sample but positive when the serum was used instead. The 4℃ test was positive when using the enzyme method but negative at warm temperatures. An unknown antibody was identified using a commercial antibody identification test (Bio-Rad, CA, USA). A clinically insignificant cold antibody was detected only in the serum samples, and the negative blood was ultimately released following the third stage of cross-matching using anti-human globulin.