During the COVID-19 pandemic, the first seasonal influenza epidemic was declared in the 37th week of 2022 in Korea and has continued through the winter of 2023–2024. However, this finding has not been observed in the United States and Europe. The present study aimed to determine whether the prolonged influenza epidemic in Korea from 2022 to 2023 was caused by using a different influenza epidemic threshold compared to the thresholds used in the United States and Europe.

Korea, the United States, and Europe use different methods to set seasonal influenza epidemic thresholds. First, we calculated the influenza epidemic thresholds for influenza seasons using the different methods of those three regions. Using these epidemic thresholds, we then compared the duration of influenza epidemics for the most recent three influenza seasons.

The epidemic thresholds estimated by the Korean method were lower than those by the other methods, and the epidemic periods defined using the Korean threshold were estimated to be longer than those defined by the other regions’ thresholds.

A low influenza epidemic threshold may have contributed to the prolonged influenza epidemic in Korea, which was declared in 2022 and has continued until late 2023. A more reliable epidemic threshold for seasonal influenza surveillance needs to be established in Korea.

The purpose of this study is to investigate the clinical efficacy and stabilityof human insulin therapy compared with conventional animal insulin therapy in respect ofadverse reactions, glycemic control, insulin requirement and subjective satisfaction.

To investigate the clinical efficacy and stability of human insulin therapy, weconducted this study in 55 university hospitals and goneral hospitals in Korea nationwide,for a period of 32 months from January 4, 1990 through December 31, 1992. The study wasset out to replace conventional animal insulin with human insulin(Humulin^R) and observedadverse reactions, changes in blood glucose levels, HbA1C, insulin requirement and subjectivesatisfaction after replacement.

Results are given as fo11ows.

1) Blood glucose level, HbAlc, and insulin requirement were significantly decreased afterreplacement animal insulin with human insulin(p<0.05).

2) As for adverse reactions, hypoglycemia was observed more frequently and the incidenceof chills and local allergic reaction at the site of insulin injection were decreased after replacement animal insulin with human insulin.

3) As for subjective satisfaction of the patients, number of patients with subjective satisfactionwere significantly increased after replacement animal insulin with human insulin(p<0.O5).

These results suggest that human insulin is preferable to animal insulins interms of glycemic control, insulin requirement and subjecive clinical response.

Reactive oxygen species (ROS) such as hydrogen peroxide, superoxide anion and hydroky radicals are produced in various physiologic and pathologic conditions and involved in many cellular processes as proliferation, differentiation and apoptosis. Studies investigating the role of ROS in various cellular behaviors especially in proliferation and apoptosis have been widely conducted in many cell types but the role of ROS in nontransformed human hepatocyte differentiation has not been investigated yet. thus we were going to elucidate the roleof ROS on human hepatocyte differentiaiton using sodium butyrate (SB) induced hepatocyte differentiation model of our own establishment.

Intracellular ROS and apoptotic cell death were monitored by flowcytometry using peroxide sensitive probe (Dicholorofluorscein diacetate) and Annexin V/Propidium iodide, respectively. Urea nitrogen in culture media was measured by colorimetric methods. Ornithine transcarbamylase(OTC) and albumin trasncription was evaluated by RT-PCR.

Intracellular ROS production was increased by SB. SB induced urea production was significantly decreased with antioxidant treatment (p<0.05) and SB induced OTC and albumin transcription were also attenuated with antioxidant treatment. SB induced increase in apoptosiswas significantly inhibited by antioxidant treatment (p<0.05).

ROS produced during the process of sodium butyrate induced human hepatocyte differentiation auguments hepatoctye differentiation and apoptosis.

Hepatic veno-occlusive disease(VOD) is a major life-threatening complication of bone marrow transplantation(BMT) caused by high-dose chemotherapy or radiotherapy. The aim of this study is to evaluate the incidence, risk factors, prophylactic effects of low-dose heparin and pentoxifylline(PTX) and therapeutic response to recombinant human tissue plasminogen activator(rt-PA) in VOD patients with leukemia after allogeneic BMT.

Thirty-two consecutive leukemia patients who underwent HLA-matched allogeneic BMT were included in this study. VOD was clinically defined as having two of the following features : hyperbilirubinemia(≥2mg/dL), tender hepatomegaly, unexplained weight gain(>2% from baseline) and/or ascites. Low-dose heparin(l00unit/kg/day, IV) and PTX(1,600mg/day, P0) were administered for the prevention of VOD.

The median age of recipients in this study was 27(17 - 44) years. Patients were treated for the following diseases : 17(53.1%) for acute myeloid leukemia(AML), 10(31.3%) for acute lymphoblastic leukemia(ALL) and 5(15.6%) for chronic myeloid leukemia(CML). Fourteen patients(43.7%) were classified as having high-risk pre-BMT status. Of the 32 consecutive patients undergoing allogeneic BMT, 5(15.6%) developed VOD. A higher risk of developing VOD was associated with pre-BMT disease status(p<0.01). All VOD patients received rt-PA-based thrombolytic therapy and complete resolution was achieved in-4(80.0%) of 5 patients without significant bleeding complications.

Further studies are needed to develop more effective prophylactic and thera-peutic approaches of VOD in patients with high-risk leukemia after allogeneic BMT.

The aim of this study is to obtain the basic knowledge for safer clinical use of oxymetazoline, one of nasal decongestants, by observing changes of ciliary activity and histopa-thologic findings after topical application of oxymetazoline to the cultured human basak mucosa.

The nasal mucosa, obtained from the inferior tubinates in healthy non-smokers without any nasal symptoms or signs, was cultured and then, exposed to oxymetazoline solu-tion at different concentrations from 0.0123% to 0.25%, containing no preservatives. Ciliary activity was observed under an inverted microscope and the histopathology of the mucosa was examined by light microscopy 1,3,6,12,24 and 48 hours after exposure, respectively.

Oxymetazoline impaired ciliary activity and induced mucosal injury at dose- and time-dependent patterns. Once the ciliary activity disappeared, it was not restored at least for the next 48 hours. Furthermore, these functional and morphologic changes resulted from applying oxymetazoline at the concentration of clinical use.

Oxymetazoline as a topical vasoconstrictor should be administered for the minimal period even at clinical dose.