Fully Automatic Coronary Calcium Score Software Empowered by Artificial Intelligence Technology:Validation Study Using Three CT Cohorts

Objective@#This study aimed to validate a deep learning-based fully automatic calcium scoring (coronary artery calcium [CAC]_auto) system using previously published cardiac computed tomography (CT) cohort data with the manually segmented coronary calcium scoring (CAC_hand) system as the reference standard. @*Materials and Methods@#We developed the CAC_auto system using 100 co-registered, non-enhanced and contrast-enhanced CT scans. For the validation of the CAC_auto system, three previously published CT cohorts (n = 2985) were chosen to represent different clinical scenarios (i.e., 2647 asymptomatic, 220 symptomatic, 118 valve disease) and four CT models. The performance of the CAC_auto system in detecting coronary calcium was determined. The reliability of the system in measuring the Agatston score as compared with CAC_hand was also evaluated per vessel and per patient using intraclass correlation coefficients (ICCs) and Bland-Altman analysis. The agreement between CAC_auto and CAC_hand based on the cardiovascular risk stratification categories (Agatston score: 0, 1–10, 11–100, 101–400, > 400) was evaluated. @*Results@#In 2985 patients, 6218 coronary calcium lesions were identified using CAC_hand. The per-lesion sensitivity and falsepositive rate of the CAC_auto system in detecting coronary calcium were 93.3% (5800 of 6218) and 0.11 false-positive lesions per patient, respectively. The CAC_auto system, in measuring the Agatston score, yielded ICCs of 0.99 for all the vessels (left main 0.91, left anterior descending 0.99, left circumflex 0.96, right coronary 0.99). The limits of agreement between CAC_auto and CAC_hand were 1.6 ± 52.2. The linearly weighted kappa value for the Agatston score categorization was 0.94. The main causes of false-positive results were image noise (29.1%, 97/333 lesions), aortic wall calcification (25.5%, 85/333 lesions), and pericardial calcification (24.3%, 81/333 lesions). @*Conclusion@#The atlas-based CAC_auto empowered by deep learning provided accurate calcium score measurement as compared with manual method and risk category classification, which could potentially streamline CAC imaging workflows.

LI-RADS version 2018 in Patients with Prior History of Hepatocellular Carcinoma: Are LR4 Observations Enough for the Diagnosis of Recurrent HCC?

Purpose@#We evaluated the diagnostic performance of LI-RADS version 2018 using gadoxetic acid enhanced MRI for recurrent but untreated HCC in patients with prior history of HCC. @*Materials and Methods@#We enrolled 50 consecutive patients who 1) prior history of treatment of HCC, 2) underwent liver surgery for radiological/clinical diagnosis of new HCC between 2013 to 2018, 3) had gadoxetic acid enhanced MRI within one month before surgery, and 4) did not have more than five HCCs or infiltrative tumors only. Two radiologists reviewed MRI and determined the presence of LR3, LR4 and LR5 observations except previously treated tumors based on LI-RADS version 2018 in consensus. We sub-classified LR4 into LR4m (LR4 with major features only) and LR4u (LR4 upgraded from LR3 by ancillary features). LR4u were further sub-classified into LR4ua (with arterial phase hyperenhancement) and LR4un (without arterial phase hyperenhancement). @*Results@#PPV for LR5, LR4 and LR3 observations for recurrent HCC were 100%, 61.5% and 25.0%, respectively. 100% (3/3) of LR4m were HCC. However, PPV of LR4u was 56.5%. PPV of LR4ua and LR4un were 73.3% and 25.0%, respectively. Sensitivity of LR5 and LR5+LR4 observations as a diagnostic threshold were 32.1% and 89.3%, respectively. Sensitivity for LR5+LR4m+LR4ua observations for diagnosis of HCC were 83.7% and significantly superior to that of LR5 without significant deterioration of specificity (75.0%). @*Conclusion@#In patients with prior history of HCC, LR4 observations by major features or with APHE may be regarded as recurrent HCCs given high sensitivity and comparable specificity/PPV to LR5 observations.

LI-RADS version 2018 in Patients with Prior History of Hepatocellular Carcinoma: Are LR4 Observations Enough for the Diagnosis of Recurrent HCC?

Purpose@#We evaluated the diagnostic performance of LI-RADS version 2018 using gadoxetic acid enhanced MRI for recurrent but untreated HCC in patients with prior history of HCC. @*Materials and Methods@#We enrolled 50 consecutive patients who 1) prior history of treatment of HCC, 2) underwent liver surgery for radiological/clinical diagnosis of new HCC between 2013 to 2018, 3) had gadoxetic acid enhanced MRI within one month before surgery, and 4) did not have more than five HCCs or infiltrative tumors only. Two radiologists reviewed MRI and determined the presence of LR3, LR4 and LR5 observations except previously treated tumors based on LI-RADS version 2018 in consensus. We sub-classified LR4 into LR4m (LR4 with major features only) and LR4u (LR4 upgraded from LR3 by ancillary features). LR4u were further sub-classified into LR4ua (with arterial phase hyperenhancement) and LR4un (without arterial phase hyperenhancement). @*Results@#PPV for LR5, LR4 and LR3 observations for recurrent HCC were 100%, 61.5% and 25.0%, respectively. 100% (3/3) of LR4m were HCC. However, PPV of LR4u was 56.5%. PPV of LR4ua and LR4un were 73.3% and 25.0%, respectively. Sensitivity of LR5 and LR5+LR4 observations as a diagnostic threshold were 32.1% and 89.3%, respectively. Sensitivity for LR5+LR4m+LR4ua observations for diagnosis of HCC were 83.7% and significantly superior to that of LR5 without significant deterioration of specificity (75.0%). @*Conclusion@#In patients with prior history of HCC, LR4 observations by major features or with APHE may be regarded as recurrent HCCs given high sensitivity and comparable specificity/PPV to LR5 observations.

Herpes Zoster in Children and Adolescents: A 10-year Retrospective Study at a Single Institution / 대한피부과학회지

BACKGROUND: Studies on herpes zoster have been extensively reported in Korea. However, few reports have dealt with herpes zoster in children and adolescents. OBJECTIVE: The purpose of this study was to investigate the epidemiological features and clinical characteristics of herpes zoster in children and adolescents. METHODS: During a 10-year period (2005~2014), 95 herpes zoster patients, aged 18 years and younger, were evaluated in regard to the annual, monthly, and seasonal incidences; the age distribution; and the gender ratio. The children and adolescents with herpes zoster were further assessed on the accompanying symptoms, dermatomal distribution, associated diseases, treatments, and complications. RESULTS: Among all the patients with herpes zoster, 2.41% were children and adolescents. The highest incidence was in summer (35.8%). The age group of 10 to 14 years had the highest incidence (40.0%). The male to female ratio was 1.4:1. The common accompanying symptoms were pain (77.9%) and pruritus (22.1%). The most common dermatomal distribution was the thoracic dermatome (50.5%), followed by the cervical (21.1%), the trigeminal (16.8%), the lumbar (7.4%) and the sacral (4.2%) dermatomes. Associated diseases including atopic dermatitis, bronchial asthma, allergic rhinitis, chronic sinusitis, and epilepsy were observed in 23.2%. There was no case with immunosuppression. The most common complication was secondary bacterial infection (5.2%), followed by herpes zoster ophthalmicus or herpes zoster generalisatus (4.2%), Ramsay Hunt syndrome (2.1%), meningitis and recurrent herpes zoster (1.1%). No patient developed postherpetic neuralgia. CONCLUSION: Herpes zoster is rare and relatively mild in healthy immunocompetent children and adolescents. Pruritus was observed in some pediatric patients, but there was no occurrence of postherpetic neuralgia.

Antifungal Susceptibility Testing with Etest for Candida Species Isolated from Patients with Oral Candidiasis

BACKGROUND: The necessity of performing antifungal susceptibility tests is recently increasing because of frequent cases of oral candidiasis caused by antifungal-resistant Candida species. The Etest (BioMerieux, Marcy l'Etoile, France) is a rapid and easy-to-perform in vitro antifungal susceptibility test. OBJECTIVE: The purpose of this study was to determine the minimal inhibitory concentrations (MICs) of antifungal agents by using the Etest for Candida species isolated from patients with oral candidiasis. METHODS: Forty-seven clinical isolates of Candida species (39 isolates of Candida albicans, 5 isolates of C. glabrata, and 3 isolates of C. tropicalis) were tested along with a reference strain (C. albicans ATCC 90028). The MIC end points of the Etest for fluconazole, itraconazole, voriconazole, and amphotericin B susceptibility were read after the 24-hour incubation of each isolate on RPMI 1640 agar. RESULTS: All Candida isolates were found susceptible to voriconazole and amphotericin B. However, all five isolates of C. glabrata were resistant to itraconazole, among which two isolates were also resistant to fluconazole. CONCLUSION: This study revealed that the Etest represented a simple and efficacious method for antifungal susceptibility testing of Candida species isolated from oral candidiasis patients. Therefore, voriconazole and amphotericin B should be recommended as effective alternatives for the treatment of oral candidiasis.

A Clinical and Mycological Study of Onychomycosis in the Elderly Over 10 Years (2001-2010) / 대한의진균학회지

BACKGROUND: As the life expectancy has risen globally because of the advance of medicine, onychomycosis in the elderly has been increasing with higher concerns over nails. Onychomycosis has been studied quite extensively, however, few reports on onychomycosis in a geriatric Korean population have been available. OBJECTIVE: The purpose of this study was to investigate the clinical features of onychomycosis in the elderly compared with other age groups and to identify the etiological agents during 10-year period. METHODS: A total of 629 patients over 65 years of age had been diagnosed with onychomycosis during a 10-year period (2001-2010). The etiological agents were identified by cultures on Sabouraud's dextrose agar with and without cycloheximide. Nondermatophytic molds and yeasts were considered as pathogens, if the identical fungal elements were observed at the initial direct microscopy and repeatedly in specimen-yielding cultures at a follow-up visit. RESULTS: The 629 elderly patients represented 22.1% of all onychomycosis patients. Toenails were involved in 567 (90.1%) patients; fingernails in 39 (6.2%); both toenails and fingernails in 23 (3.7%). The ratio of male to female was 1.01:1. Associated systemic diseases were found in 327 (52.0%) cases. Distal and lateral subungual onychomycosis (80.2%) was the most common clinical type of onychomycosis, followed by TDO (10.7%), SWO (6.2%) and PSO (2.9%). TDO was increasing significantly in the elderly. Organisms causing onychomycosis were dermatophytes (76.5%), yeasts (14.3%) and nondermatophytic molds (9.2%). The most common cause of onychomycosis in the elderly was Trichophyton rubrum. Nondermatophytic molds were more frequently responsible for onychomycosis in the elderly. CONCLUSION: Onychomycosis has been increased in the elderly and there are many differences from other age groups in aspects of clinical features, associated diseases and etiologic agents. Therefore, we suggest the need of a careful mycological examination in the elderly patients with onychomycosis.

Onychomycosis Caused by Chaetomium globosum

Onychomycosis is usually caused by dermatophytes, but some nondermatophytic molds and yeasts are also associated with invasion of nails. The genus Chaetomium is a dematiaceous nondermatophytic mold found in soil and plant debris as a saprophytic fungus. We report the first Korean case of onychomycosis caused by Chaetomium globosum in a 35-year-old male. The patient showed brownish-yellow discoloration and subungual hyperkeratosis on the right toenails (1st and 5th) and left toenails (1st and 4th). Direct microscopic examination of scraping on the potassium hydroxide preparation revealed septate hyphae and repeated cultures on Sabouraud's dextrose agar (SDA) without cycloheximide slants showed the same fast-growing colonies, which were initially velvety white then turned to dark gray to brown. However, there was no growth of colony on SDA with cycloheximide slants. Brown-colored septated hyphae, perithecia and ascospores were shown in the slide culture. The DNA sequence of internal transcribed spacer region of the clinical sample was a 100% match to that of C. globosum strain ATCC 6205 (GenBank accession number EF524036.1). We confirmed C. globosum by KOH mount, colony, and light microscopic morphology and DNA sequence analysis. The patient was treated with 250 mg oral terbinafine daily and topical amorolfine 5% nail lacquer for 3 months.

Onychomycosis Caused by Scopulariopsis brevicaulis: Report of Two Cases

Onychomycosis is usually caused by dermatophytes, but some nondermatophytic molds and yeasts are also associated with invasion of nails. Scopulariopsis brevicaulis is a nondermatophytic mold found in soil as a saprophyte. We report two cases of onychomycosis caused by S. brevicaulis in a 48-year-old male and a 79-year-old female. The two patients presented with a typical distal and lateral subungual onychomycosis. Direct microscopic examination of the potassium hydroxide preparation revealed fungal elements. From toenail lesions of the patients, brown colonies with powdery surface, which are a characteristic of S. brevicaulis, were cultured on two Sabouraud's dextrose agar plates. Three cultures taken from nail plates within a 2-week interval yielded similar findings. Numerous branched conidiophores with chains of rough walled, lemon-shaped conidia were observed in slide culture by light microscopy and scanning electron microscopy. The nucleotide sequences of the internal transcribed spacer for the two clinical isolates were identical to that of S. brevicaulis strain WM 04.498. To date, a total of 13 cases of S. brevicaulis onychomycosis including the two present cases have been reported in Korea. Mean age of the patients was 46.1 years, with a higher prevalence in males (69.2%). Toenail involvement was observed in all cases including a case involving both fingernail and toenail. The most frequent clinical presentation was distal and lateral subungual onychomycosis in 12 cases, while one case was proximal subungual onychomycosis.

Hygienic State and Awareness of Drink Vending Machines in a City / 農村醫學 地域保健

OBJECTIVE: This study was conducted to investigate the hygienic state and awareness of drink vending machines in a city. METHODS: Twelve of the most frequently used vending machines in various areas were selected in October 2008. As soon as fresh samples of milk coffee and adlay tea were collected in sterile containers from each machine, the temperature was measured. The samples were carried on ice to the laboratory to test total plate counts and Escherichia coli contamination. College students were inquired about drink vending machine hygiene by implementing self-developed questionnaires. RESULTS: The temperature of 6 milk coffee samples (50.0%) and 8 adlay tea samples (66.7%) turned out to be inadequate. The total plate counts of milk coffee samples were all adequate, although 9 adlay tea samples (75.0%) were inadequate. All the beverage samples were negative for E. coli. In questionnaires obtained from 74 users of coffee vending machines, only 2 (2.7%) expected the hygienic state of vending machines to be good. There were 27 people (33.3%) that knew the existence of hygiene-related laws for vending machines. CONCLUSIONS: This study reveals that the hygienic state of drink vending machines insufficiently reaches the standard for the hot beverage and that most people are not aware of importance of vending machine hygiene. It is necessary to make improvement in the hygiene of vending machines and public awareness in this city.

Insertional Mutation of ftsH Gene in Streptococcus pneumoniae Causes Stress Sensitivities

FtsH is a membrane-bound, ATP-dependent protease involved in various cellular functions. To understand its roles in Streptococcus pneumoniae and host-pathogen interactions, we inactivated the ftsH gene of D39 strain by inserting a tetracycline-resistance (tet) gene. Several recombinants containing the tet cassette within the ftsH gene were confirmed by Western immunoblotting for the absence of pneumococcal FtsH protein that could cross-react with antiserum raised against Escherichia coli FtsH. Compared with the wild-type D39 strain, the ftsH null mutants grew slowly with encapsulation and alpha-hemolysis on blood agar plates, but failed to grow in liquid media other than Todd Hewitt yeast extract broth. Even fresh cultures of ftsH null mutants appeared gram-negative. When the incubation temperature of liquid cultures was shifted from 37degrees C to 40degrees C, the mutants gradually lysed, whereas the shift to 30degrees C abolished further growth. The mutants also exhibited increased sensitivity to salt and remarkable growth inhibition by optochin. These observations suggest that no functional FtsH protein in pneumococcal cells causes a loss of cell surface integrity, resulting in impairment of cell growth under normal and stressful conditions.

Insertional Mutation of ftsH Gene in Streptococcus pneumoniae Causes Stress Sensitivities

FtsH is a membrane-bound, ATP-dependent protease involved in various cellular functions. To understand its roles in Streptococcus pneumoniae and host-pathogen interactions, we inactivated the ftsH gene of D39 strain by inserting a tetracycline-resistance (tet) gene. Several recombinants containing the tet cassette within the ftsH gene were confirmed by Western immunoblotting for the absence of pneumococcal FtsH protein that could cross-react with antiserum raised against Escherichia coli FtsH. Compared with the wild-type D39 strain, the ftsH null mutants grew slowly with encapsulation and alpha-hemolysis on blood agar plates, but failed to grow in liquid media other than Todd Hewitt yeast extract broth. Even fresh cultures of ftsH null mutants appeared gram-negative. When the incubation temperature of liquid cultures was shifted from 37degrees C to 40degrees C, the mutants gradually lysed, whereas the shift to 30degrees C abolished further growth. The mutants also exhibited increased sensitivity to salt and remarkable growth inhibition by optochin. These observations suggest that no functional FtsH protein in pneumococcal cells causes a loss of cell surface integrity, resulting in impairment of cell growth under normal and stressful conditions.

Characterization and expression in Escherichi coli of Streptococcus pneumoniae FtsH

FtsH is a membrane-bound, ATP-dependent metalloprotease that is involved in a variety of cellular functions including the regulation of responses to heat and stress shock. Previously, we had cloned and sequenced pneumococcal ftsH gene whose deduced amino acid sequence was very similar to those of several gram-positive bacteria and Escherichia coli, except for the N-terminal domain that was responsible for membrane anchoring. In order to better understand the role of Streptococcus pneumoniae FtsH, we expressed pneumococcal ftsH gene in Escherichia coli. When it was expressed from a strong promoter, Ptac, a considerable amount of the recombinant FtsH was produced, although the prolonged induction resulted in not only accumulation of breakdown products but also ceasing of the further growth of E. coli host. This indicated that the expression of the exogenous ftsH gene was tightly regulated since the excessive FtsH appeared detrimental to bacterial cells. In Western blotting, the pneumococcal FtsH protein, whether native or recombinant, was reactive to anti-E. coli FtsH serum. The observation that FtsH proteins were well conserved throughout the bacterial kingdom and its expression level was fine-tuned suggests an important role for this protein in the stress adaptation which may be related to infecting process by pneumococci.