Background/Aims: Cardiorespiratory fitness (CRF), as measured by maximal oxygen consumption (VO2max), is an important independent predictive factor of cardiovascular outcomes in patients with heart failure (HF). However, it is unclear whether conventional equations for estimating CRF are applicable to patients with HF with preserved ejection fraction (HFpEF). Methods: This study included 521 patients with HFpEF (EF ≥ 50%) whose CRF was directly measured by cardiopulmonary exercise test using a treadmill. We developed a new equation (Kor-HFpEF) for half of the patients in the HFpEF cohort (group A, n = 253) and validated it for the remaining half (group B, n = 268). The accuracy of the Kor-HFpEF equation was compared to that of the other equations in the validation group. Results: In the total HFpEF cohort, the directly measured VO2max was significantly overestimated by the FRIEND and ACSM equations (p < 0.001) and underestimated by the FRIEND-HF equation (p <0.001) (direct 21.2 ± 5.9 mL/kg/min; FRIEND 29.1 ± 11.8 mL/kg/min; ACSM 32.5 ± 13.4 mL/kg/min; FRIEND-HF 14.1 ± 4.9 mL/kg/min). However, the VO2max estimated by the Kor-HFpEF equation (21.3 ± 4.6 mL/kg/min) was similar to the directly measured VO2max (21.7 ± 5.9 mL/kg/min, p = 0.124), whereas the VO2max estimated by the other three equations was still significantly different from the directly measured VO2max in group B (all p < 0.001). Conclusions Traditional equations used to estimate VO2max were not applicable to patients with HFpEF. We developed and validated a new Kor-HFpEF equation for these patients, which had a high accuracy.

Thoracic foreign bodies (FBs) are serious and relatively frequent in emergency departments. Thoracic FBs may occur in association with aspiration, ingestion, trauma, or iatrogenic causes. Imaging plays an important role in the identification of FBs and their dimensions, structures, and locations, before the initiation of interventional treatment. To guide proper clinical management, radiologists should be aware of the radiologic presentations and the consequences of thoracic FBs. In this pictorial essay, we reviewed the optimal imaging settings to identify FBs in the thorax, classified thoracic FBs into four types according to their etiology, and reviewed the characteristic imaging features and the possible complications.

Background/Aims: To prevent the perinatal transmission of hepatitis B virus (HBV) from mother to child, administration of an antiviral agent during pregnancy has been attempted in women who are either hepatitis B e antigen positive or have a high viral load. In this systematic review and meta-analysis with randomized controlled trials, we analyzed the efficacy and safety of tenofovir disoproxil fumarate (TDF) in preventing the perinatal transmission of HBV in pregnant women who have high HBV DNA titers. Methods: Multiple comprehensive databases (PubMed, EMBASE, and Cochrane databases) were searched for studies evaluating the efficacy of TDF for the prevention of perinatal transmission of HBV. Results: Two studies (one open label study and one double blind study) were included and analyzed. Intention-to-treat analysis (527 pregnancies) showed that the preventive effect of TDF was not significant (odds ratio [OR], 0.53; 95% confidence interval[CI], 0.13 to 2.17; p = 0.38, I2 = 81%). However, the per-protocol analysis showed that TDF significantly reduced perinatal transmission (OR, 0.10; 95% CI, 0.01 to 0.77; p = 0.03, I2 = 0%). There was no significant difference between the TDF group and the control group with respect to maternal and fetal safety outcomes. Conclusions In pregnant women who have high HBV DNA titers, TDF can reduce the perinatal transmission from mother to child without significant adverse events.

OBJECTIVES: Studies on Clostridium difficile are rare in Korea. We investigated the epidemiological characteristics of C. difficile isolates from patients with C. difficile-associated disease (CDAD) in Korea. METHODS: Multiplex polymerase chain reaction was performed to detect the presence of tcdA and tcdB toxin genes. Antimicrobial susceptibility test was carried out by the disk-dilution method. C. difficile strains were subtyped by automated repetitive-element palindromic PCR (rep-PCR). RESULTS: Among patients with CDAD, 73 (25.8%), 32 (11.3%), 32 (11.3%), and 26 (9.2%) suffered from pneumonia, cancer or neoplasm, diabetes, and colitis, respectively. Of all stool samples, 43 samples (15.2%) were positive for C. difficile strains. We observed two expression patterns of toxin genes: tcdA+/tcdB+ (86% isolates) and tcdA−/tcdB+ (14% isolates), with all isolates expressing tcdB. Furthermore, some isolates were resistant to clindamycin (65%), ampicillin (56%), and cefazolin (40%), but all were susceptible to vancomycin and metronidazole. The tested samples were classified into diverse clusters using automated rep-PCR. CONCLUSION: Our findings revealed the characteristics and antibiotic resistance of C. difficile isolates from patients in Korea. The epidemiological data may provide valuable insight into development of treatment strategies for C. difficile infections in Korea.
Ampicillin ; Cefazolin ; Clindamycin ; Clostridium difficile* ; Clostridium* ; Colitis ; Drug Resistance, Microbial ; Humans ; Korea* ; Methods ; Metronidazole ; Multiplex Polymerase Chain Reaction ; Pneumonia ; Polymerase Chain Reaction ; Vancomycin

Amyloidosis is defined as the presence of extra-cellular deposits of an insoluble fibrillar protein, amyloid. The pulmonary involvement of amyloidosis is usually classified as tracheobronchial, parenchymal nodular, or diffuse alveolar septal. A single nodular lesion can mimic various conditions, including malignancy, pulmonary tuberculosis, and fungal infection. To date, only one case of nodular pulmonary amyloidosis has been reported in Korea, a case involving multiple nodular lesions. Here, we report and discuss the case of a patient having single nodular amyloidosis.
Amyloid ; Amyloidosis* ; Humans ; Korea ; Tuberculosis, Pulmonary

Infliximab is a chimeric anti-tumor necrosis factor-alpha monoclonal antibody. Infusion related reactions and infection are well known side effects of infliximab; however, renal complications have not been well recognized. We report on a patient with late onset-acute tubulointerstitial nephritis (ATIN) after treatment with infliximab and mesalazine for Crohn's disease. A 25-year-old woman was admitted with a purpuric rash on both lower extremities and arthralgia. She had been diagnosed with Crohn's disease 5.6 years previously and had been treated with mesalazine and infliximab. Serum creatinine level, last measured one year ago, was elevated from 0.6 mg/dL to 1.9 mg/dL. Results of urinalysis, ultrasound, and serologic examinations were normal. With a tentative diagnosis of Henoch-Schonlein purpura, oral prednisolone was given, and serum creatinine decreased to 1.46 mg/dL, but was elevated to 2.6 mg/dL again at two months after discontinuation of prednisolone. Renal biopsy indicated that ATIN was probably induced by drug, considering significant infiltration of eosinophils. Concomitant use of infliximab with mesalazine was supposed to trigger ATIN. Oral prednisolone was administered, and serum creatinine level showed partial recovery. Thus, ATIN should be suspected as a cause of renal impairment in Crohn's disease even after a long period of maintenance treatment with infliximab and mesalazine.
Adalimumab/therapeutic use ; Anti-Inflammatory Agents/therapeutic use ; Creatine/blood ; Crohn Disease/*drug therapy ; Drug Therapy, Combination ; Eosinophils/immunology ; Female ; Humans ; Infliximab/*adverse effects/*therapeutic use ; Kidney/pathology ; Mesalamine/*adverse effects/*therapeutic use ; Nephritis, Interstitial/*diagnosis/drug therapy/*etiology ; Prednisolone/therapeutic use

In this study, to understand the pathogenesis of new rabbit hemorrhagic disease virus (RHDVa) serotype, we carried out to administrate RHDVa to rabbits, and to examine sequential electron microscopic changes and relationship between pathogenesis and apoptosis. TUNEL-positive cells began to be observed from 24 hours after inoculation (HAI) and the number of positive cells was slightly increased with the course of time. Whereas marked increase of positive cells was seen in the liver from the rabbits died acutely. Typical viral particles with cup-like projections and a diameter of 30~40 nm were detected in homogenized liver samples and tissues at 36 and 48, and 48 HAI, respectively. Ultrastructurally, glycogen deposition was observed from the first stage of hepatocellular degeneration by RHDVa infection and then, swelling and disruption of cristae of mitochondria by viral particles, swelling of smooth endoplasmic reticulum, vacuoles and vesicles were detected. Condensation, margination and fragmentation of chromatin were observed in degenerative hepatocytes at 36 and 48 HAI, indicating apoptotic bodies. These data offer that hepatocytic apoptosis by RHDV infection could be closely related with mitochondrial impairment in the hepatocytes.
Apoptosis ; Chromatin ; Electrons ; Endoplasmic Reticulum, Smooth ; Glycogen ; Hemorrhagic Disease Virus, Rabbit ; Hepatocytes ; Liver ; Mitochondria ; Rabbits ; Sprains and Strains ; Vacuoles ; Virion

Recent advances in endoscopic instruments, including narrow-band imaging (NBI) and magnification endoscopy, allowed dramatic increase in the early diagnosis of hypopharyngeal cancers. In addition, endoscopic mucosal resection or endoscopic submucosal dissection has recently been used for the treatment of hypopharyngeal cancer at an early stage, especially in Japan. However, to date, there is no published report in Korea. A 68-year-old man was admitted for preoperative evaluation and treatment for known esophageal cancer initially diagnosed at a local clinic. During the evaluation, magnifying endoscopy combined with the NBI system revealed a concurrent hypopharyngeal cancer not detected by initial conventional endoscopy. In this case report, we describe for the first time in Korea a case of early stage hypopharyngeal carcinoma that was successfully treated by endoscopic submucosal dissection with a review of literature.
Aged ; Carcinoma/*diagnosis/pathology/surgery ; Dissection ; Endoscopy, Gastrointestinal ; Humans ; Hypopharyngeal Neoplasms/*diagnosis/pathology/surgery ; Male ; Tomography, X-Ray Computed

BACKGROUND/AIMS: Endoscopic submucosal dissection (ESD) is accepted as a standard treatment of early gastric cancer (EGC) and gastric adenoma. Occasionally, tumorous lesion is not found and pathologic discrepancies can occur after ESD. The aim of this study was to analyze the factors affecting the negative pathologic results after ESD. METHODS: We retrospectively reviewed the data from all patients with gastric neoplasm (276 EGC and 516 gastric adenomas) who were treated with ESD during past 3 years and enrolled the patients who had negative pathologic results. RESULTS: Out of 792 patients treated with ESD, 27 patients (3.4%) were eligible for inclusion. Among the 27 patients, factors affecting the negative pathologic results were, most commonly, the focal lesion (n=13, 48.2%) which was small enough to be removed completely during pre-ESD biopsy, followed by pathologic discrepancies (n=11, 40.7%) between pathologists and lastly the operator factor (n=3, 11.1%) dissecting incorrect lesions. Of the focal lesions, the initial pathologic diagnoses were adenocarcinoma in 11 cases (84.6%). In cases with pathologic discrepancies, all the pretreatment diagnoses were adenoma with low grade dysplasia. In cases caused by operator factors, intestinal metaplasia was accompanied by elevated adenoma in all cases. CONCLUSIONS: To decrease negative pathologic results after ESD, an endoscopist should perform ESD after sufficient communication with pathologists, especially for adenoma with low grade dysplasia, and choose correct lesion, especially located at the antrum and associated with intestinal metaplasia. The possibility of total removal of small lesions even by forcep biopsy should be considered.
Adenocarcinoma/*diagnosis/pathology/surgery ; Aged ; Dissection ; Female ; Gastric Mucosa/pathology ; Gastroscopy ; Humans ; Male ; Middle Aged ; Retrospective Studies ; Stomach Neoplasms/*diagnosis/pathology/surgery

Rabbit hemorrhagic disease is a highly acute and fatal viral disease caused by rabbit hemorrhagic disease virus (RHDV). Since first outbreak in Korea 1987, RHDV has been continually affected in the country, but the pattern of outbreak seem to be changed. In this study, to understand the pathogenesis of the new RHDVa serotype, we therefore carried out to inoculate RHDVa to rabbits, and to examine the sequential histopathologic changes and viral distribution. Macroscopically, various sized dark red or white spots or appearance were observed in the liver, lung, kidney uterus and ureter. In euhanized rabbits, significant pathologic findings such as infiltration of heterophils and mononuclear cells were observed at 24 hours after inoculation (HAI), and these were sequentially extended periportal to centrilobular area. However, in dead rabbits, severe hepatic degeneration and/or necrosis with relatively weak inflammatory responses were observed. RHDV antigens began to detect in liver, spleen, and lung from 12 HAI by PCR. Immunohistochemically, RHDV positive cells were seen in only liver from 24 HAI, and the degree of immunogen reactivity was stronger in dead rabbits than in euthanized ones. In conclusion, RHDVa caused the subacute or chronic infection accompanying low mortality and moderate to severe inflammatory reaction in rabbits, suggesting the possibility that RHD could become endemic.
Dental Caries ; Hemorrhagic Disease Virus, Rabbit ; Kidney ; Korea ; Liver ; Lung ; Necrosis ; Polymerase Chain Reaction ; Rabbits ; Spleen ; Sprains and Strains ; Ureter ; Uterus ; Virus Diseases