Background and Objectives: The purpose of this study is to investigate the vocal development in toddlers with simultaneous bilateral cochlear implants (bilateral CI group) and to compare their progress to that of chronological age-matched (CA group) and hearing agematched (HA group) toddlers who have normal hearing and typical development.Subjects and Method Thirteen toddlers who received bilateral CIs simultaneously before 18 months of age participated in this study. Twenty-six toddlers participated as the control groups (CA group and HA group). The spontaneous utterances were collected from each toddler during free play with their parents in the laboratory. A total of 2324 spontaneous utterances of 39 toddlers (13 toddlers in each of the three groups) were classified as either canonical vocalizations or noncanonical vocalizations. Results: The bilateral CI group produced significantly fewer canonical vocalizations than the CA group. However, there was not a significant difference in the ratio of canonical vocalizations between the CI and the CA groups. There were no significant differences in the frequency and ratio of canonical vocalization between the CI and HA groups. In the CI group, the frequency of canonical and noncanonical vocalizations was significantly correlated with receptive and expressive language scores. Conclusion The findings of this study showed that toddlers with bilateral CIs make good advancements in vocal development compared to toddlers with normal hearing. However, toddlers with bilateral CIs seem to produce an insufficient quantity of canonical vocalizations compared to age-matched hearing toddlers. Information about vocal development following simultaneous bilateral CI helps speech therapists and parents recognize speech development before the use of intelligible speech in communication.

Background and Objectives: The purpose of this study is to investigate the vocal development in toddlers with simultaneous bilateral cochlear implants (bilateral CI group) and to compare their progress to that of chronological age-matched (CA group) and hearing agematched (HA group) toddlers who have normal hearing and typical development.Subjects and Method Thirteen toddlers who received bilateral CIs simultaneously before 18 months of age participated in this study. Twenty-six toddlers participated as the control groups (CA group and HA group). The spontaneous utterances were collected from each toddler during free play with their parents in the laboratory. A total of 2324 spontaneous utterances of 39 toddlers (13 toddlers in each of the three groups) were classified as either canonical vocalizations or noncanonical vocalizations. Results: The bilateral CI group produced significantly fewer canonical vocalizations than the CA group. However, there was not a significant difference in the ratio of canonical vocalizations between the CI and the CA groups. There were no significant differences in the frequency and ratio of canonical vocalization between the CI and HA groups. In the CI group, the frequency of canonical and noncanonical vocalizations was significantly correlated with receptive and expressive language scores. Conclusion The findings of this study showed that toddlers with bilateral CIs make good advancements in vocal development compared to toddlers with normal hearing. However, toddlers with bilateral CIs seem to produce an insufficient quantity of canonical vocalizations compared to age-matched hearing toddlers. Information about vocal development following simultaneous bilateral CI helps speech therapists and parents recognize speech development before the use of intelligible speech in communication.

Background and Objectives: The purpose of this study is to investigate the vocal development in toddlers with simultaneous bilateral cochlear implants (bilateral CI group) and to compare their progress to that of chronological age-matched (CA group) and hearing agematched (HA group) toddlers who have normal hearing and typical development.Subjects and Method Thirteen toddlers who received bilateral CIs simultaneously before 18 months of age participated in this study. Twenty-six toddlers participated as the control groups (CA group and HA group). The spontaneous utterances were collected from each toddler during free play with their parents in the laboratory. A total of 2324 spontaneous utterances of 39 toddlers (13 toddlers in each of the three groups) were classified as either canonical vocalizations or noncanonical vocalizations. Results: The bilateral CI group produced significantly fewer canonical vocalizations than the CA group. However, there was not a significant difference in the ratio of canonical vocalizations between the CI and the CA groups. There were no significant differences in the frequency and ratio of canonical vocalization between the CI and HA groups. In the CI group, the frequency of canonical and noncanonical vocalizations was significantly correlated with receptive and expressive language scores. Conclusion The findings of this study showed that toddlers with bilateral CIs make good advancements in vocal development compared to toddlers with normal hearing. However, toddlers with bilateral CIs seem to produce an insufficient quantity of canonical vocalizations compared to age-matched hearing toddlers. Information about vocal development following simultaneous bilateral CI helps speech therapists and parents recognize speech development before the use of intelligible speech in communication.

Background and Objectives: The purpose of this study is to investigate the vocal development in toddlers with simultaneous bilateral cochlear implants (bilateral CI group) and to compare their progress to that of chronological age-matched (CA group) and hearing agematched (HA group) toddlers who have normal hearing and typical development.Subjects and Method Thirteen toddlers who received bilateral CIs simultaneously before 18 months of age participated in this study. Twenty-six toddlers participated as the control groups (CA group and HA group). The spontaneous utterances were collected from each toddler during free play with their parents in the laboratory. A total of 2324 spontaneous utterances of 39 toddlers (13 toddlers in each of the three groups) were classified as either canonical vocalizations or noncanonical vocalizations. Results: The bilateral CI group produced significantly fewer canonical vocalizations than the CA group. However, there was not a significant difference in the ratio of canonical vocalizations between the CI and the CA groups. There were no significant differences in the frequency and ratio of canonical vocalization between the CI and HA groups. In the CI group, the frequency of canonical and noncanonical vocalizations was significantly correlated with receptive and expressive language scores. Conclusion The findings of this study showed that toddlers with bilateral CIs make good advancements in vocal development compared to toddlers with normal hearing. However, toddlers with bilateral CIs seem to produce an insufficient quantity of canonical vocalizations compared to age-matched hearing toddlers. Information about vocal development following simultaneous bilateral CI helps speech therapists and parents recognize speech development before the use of intelligible speech in communication.

Background and Objectives: The purpose of this study is to investigate the vocal development in toddlers with simultaneous bilateral cochlear implants (bilateral CI group) and to compare their progress to that of chronological age-matched (CA group) and hearing agematched (HA group) toddlers who have normal hearing and typical development.Subjects and Method Thirteen toddlers who received bilateral CIs simultaneously before 18 months of age participated in this study. Twenty-six toddlers participated as the control groups (CA group and HA group). The spontaneous utterances were collected from each toddler during free play with their parents in the laboratory. A total of 2324 spontaneous utterances of 39 toddlers (13 toddlers in each of the three groups) were classified as either canonical vocalizations or noncanonical vocalizations. Results: The bilateral CI group produced significantly fewer canonical vocalizations than the CA group. However, there was not a significant difference in the ratio of canonical vocalizations between the CI and the CA groups. There were no significant differences in the frequency and ratio of canonical vocalization between the CI and HA groups. In the CI group, the frequency of canonical and noncanonical vocalizations was significantly correlated with receptive and expressive language scores. Conclusion The findings of this study showed that toddlers with bilateral CIs make good advancements in vocal development compared to toddlers with normal hearing. However, toddlers with bilateral CIs seem to produce an insufficient quantity of canonical vocalizations compared to age-matched hearing toddlers. Information about vocal development following simultaneous bilateral CI helps speech therapists and parents recognize speech development before the use of intelligible speech in communication.

Purpose: This study investigated pathological complete response (pCR) according to androgen receptor (AR) in breast cancer patients undergoing neoadjuvant chemotherapy and estimated the relationship between AR expression and clinicopathological factors. Materials and Methods: We identified 624 breast cancer patients who underwent surgery after neoadjuvant chemotherapy at the National Cancer Center in Goyang, Korea from April 2016 to October 2019. We retrospectively collected the clinicopathologic information and AR expression results and analyzed the data according to cancer stage, hormonal receptor (HR) status, human epidermal growth factor receptor 2 (HER2) status, tumor subtype, and pCR. Results: Among the 624 breast cancer patients, 529 (84.8%) were AR-positive (AR+) patients and 95 (15.2%) were AR-negative (AR–) patients. AR+ patients showed more estrogen receptor (ER) positivity, progesterone receptor (PR) positivity, HER2-positivity, and HR-positive and HER2-negative (HR+/HER2–) subtype. The rate of pCR was 31.4% (196/624). AR– patients had a significantly higher rate of pCR than AR+ patients (AR– 43.2% vs. AR+ 29.3%, p=0.007). The tumor factors associated with pCR were early stage, histologic grade 3, ER-negative, PR-negative, AR-negative, HER2-positive, and high Ki-67 values. In univariable analysis, AR+ significantly decreased the state of pCR (odds ratio, 0.546; 95% confidence interval, 0.349 to 0.853; p=0.008). According to tumor subtype, AR– tumor showed higher pCR rate in HR+/HER2– subtype (AR– 28.6% vs. AR+ 7.3%, p=0.022). Conclusion AR expression is predominant in the HR+/HER2– subtype. AR– is significantly associated with the pCR rate in breast cancer patients, especially within HR+/HER2– subtype. When determining neoadjuvant chemotherapy for the HR+/HER2– subtype, AR expression can be considered as a pCR predictive marker.

There are limited data directly comparing humoral and T cell responses to the ChAdOx1 nCoV-19 and BNT162b2 vaccines. We compared Ab and T cell responses after first doses of ChAdOx1 nCoV-19 vs. BNT162b2 vaccines. We enrolled healthcare workers who received ChAdOx1 nCoV-19 or BNT162b2 vaccine in Seoul, Korea. Anti-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) S1 protein-specific IgG Abs (S1-IgG), neutralizing Abs (NT Abs), and SARS-CoV-2-specific T cell response were evaluated before vaccination and at 1-wk intervals for 3 wks after vaccination. A total of 76 persons, comprising 40 injected with the ChAdOx1 vaccine and 36 injected with the BNT162b2 vaccine, participated in this study. At 3 wks after vaccination, the mean levels (±SD) of S1-IgG and NT Abs in the BNT162b2 participants were significantly higher than in the ChAdOx1 participants (S1-IgG, 14.03±7.20 vs. 6.28±8.87, p<0.0001; NT Ab, 183.1±155.6 vs. 116.6±116.2, p=0.035), respectively. However, the mean values of the T cell responses in the 2 groups were comparable after 2 wks. The humoral immune response after the 1st dose of BNT162b2 developed faster and was stronger than after the 1st dose of ChAdOx1. However, the T cell responses to BNT162b2 and ChAdOx1 were similar.

Correlation between vaccine reactogenicity and immunogenicity against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is unclear. Thus, we investigated to determine whether the reactogenicity after coronavirus disease 2019 vaccination is associated with antibody (Ab) titers and T cell responses. This study was prospective cohort study done with 131 healthcare workers at tertiary center in Seoul, South Korea. The degrees of the local reactions after the 1st and 2nd doses of ChAdOx1 nCov-19 (ChAdOx1) vaccination were significantly associated with the S1-specific IgG Ab titers (p=0.003 and 0.01, respectively) and neutralizing Ab (p=0.04 and 0.10, respectively) in age- and sex-adjusted multivariate analysis, whereas those after the BNT162b2 vaccination did not show significant associations. T cell responses did not show significant associations with the degree of reactogenicity after the ChAdOx1 vaccination or the BNT162b2 vaccination. Thus, high degree of local reactogenicity after the ChAdOx1 vaccine may be used as an indicator of strong humoral immune responses against SARS-CoV-2.

Background: Papillary breast lesions (PBLs) comprise diverse entities from benign and atypical lesions to malignant tumors. Although PBLs are characterized by a papillary growth pattern, it is challenging to achieve high diagnostic accuracy and reproducibility. Thus, we investigated the diagnostic reproducibility of PBLs in core needle biopsy (CNB) specimens with World Health Organization (WHO) classification. Methods: Diagnostic reproducibility was assessed using interobserver variability (kappa value, κ) and agreement rate in the pathologic diagnosis of 60 PBL cases on CNB among 20 breast pathologists affiliated with 20 medical institutions in Korea. This analysis was performed using hematoxylin and eosin (H&E) staining and immunohistochemical (IHC) staining for cytokeratin 5 (CK5) and p63. The pathologic diagnosis of PBLs was based on WHO classification, which was used to establish simple classifications (4-tier, 3-tier, and 2-tier). Results: On WHO classification, H&E staining exhibited ‘fair agreement’ (κ = 0.21) with a 47.0% agreement rate. Simple classifications presented improvement in interobserver variability and agreement rate. IHC staining increased the kappa value and agreement rate in all the classifications. Despite IHC staining, the encapsulated/solid papillary carcinoma (EPC/SPC) subgroup (κ = 0.16) exhibited lower agreement compared to the non-EPC/SPC subgroup (κ = 0.35) with WHO classification, which was similar to the results of any other classification systems. Conclusions Although the use of IHC staining for CK5 and p63 increased the diagnostic agreement of PBLs in CNB specimens, WHO classification exhibited a higher discordance rate compared to any other classifications. Therefore, this result warrants further intensive consensus studies to improve the diagnostic reproducibility of PBLs with WHO classification.

During the 2019 domestic measles outbreak in Korea, measles occurred in healthcare workers with two doses of the measles, mumps and rubella vaccine, and the strict application of the Occupational Safety and Health Act required medical institutions to identify healthcare workers' immunity to measles and vaccinate the susceptible pockets. In response to the frontline medical institutions' request to review the measles recommendations and guidelines, the Korean Society of Infectious Diseases held a roundtable discussion on the causes of measles outbreak, timing of vaccinations, antibody tests, and booster vaccinations for healthcare workers, and financial support from the government and municipality as well as response strategies against the outbreak in healthcare settings. In Korea, the seroprevalence of measles is decreasing in the vaccine-induced immunity group during the maintenance of measles elimination over several years. The susceptible group against measles is in their 20s and 30s, and this may be because of waning immunity rather than nonresponse considering Korea's vaccine policy. The risk of measles nosocomial infection from community increases as these susceptible pockets actively engage in medical institutions.Thus, data on the immunity of low seroprevalence group in Korea are needed, further discussion is needed on the booster vaccination based on the data. Especially, antibody testing and vaccination in healthcare workers may be necessary to prevent the spread of measles in medical insutitutions, and further discussion is needed regarding specific testing methods, and the timing and frequency of test and vaccination.