Biomedical subjects

Minhee Kang

Publications and source records attributed to Minhee Kang.

7 recordsLinked to original sources

PubMed2025

Species distribution of nontuberculous mycobacteria isolated from respiratory specimens at a tertiary care hospital in South Korea, 2017-2022.

The clinical relevance and drug resistance patterns of nontuberculous mycobacteria (NTM) vary by species. This study investigated the species distribution of NTM isolated from respiratory specimens at a tertiary care hospital in South Korea from 2017 to 2022. A retrospective analysis was conducted on laboratory data from respiratory specimens submitted for acid-fast bacilli culture. NTM isolates were identified using a line probe assay, and those unidentifiable at the species or complex level underwent multigene sequencing of the 16S rRNA, rpoB, and hsp65 genes. Among all mycobacterial isolates, the proportion of NTM showed an increasing trend, rising from 87.4% in 2017 to 93.3% in 2022. The eight most common species were M. avium complex (61.9%), M. abscessus (14.2%), M. fortuitum complex (8.4%), M. gordonae (5.3%), M. simiae complex (3.4%), M. kansasii complex (1.9%), M. terrae complex (1.5%), and M. chelonae (1.2%), accounting for 97.7% of all NTM isolates. Among the remaining isolates (2.3%, n = 169), 161 were classified into 24 species and groups, the majority with proportions below 0.1%. Two of the eight isolates that could not be identified at the species or group level despite multigene sequencing underwent whole-genome sequencing, which suggested they likely represent novel Mycobacterium species. This study provides valuable insights into the distribution of NTM species, particularly rarely encountered species, isolated from respiratory specimens in South Korea. These findings may aid in optimizing diagnostic strategies and selecting appropriate treatment options.IMPORTANCEGiven the significant variations in clinical relevance and drug resistance patterns among nontuberculous mycobacteria (NTM) species, understanding their geographic distribution is essential for selecting appropriate treatment options and improving patient outcomes. This study investigated the distribution of NTM species isolated from respiratory specimens at a tertiary care hospital in South Korea from 2017 to 2022. Our findings revealed an increasing proportion of NTM, with M. avium complex and M. abscessus remaining predominant. Additionally, we identified 24 rarely encountered species and groups, along with two strains that likely represent novel Mycobacterium species. Our study advances the understanding of the evolving NTM epidemiology in South Korea, contributing to the optimization of diagnostic strategies and improvement of patient management.

Republic of Korea↗

PubMed2006

Statistical methods for panel data from a semi-Markov process, with application to HPV.

Continuous-time, multistate processes can be used to represent a variety of biological processes in the public health sciences; yet the analysis of such processes is complex when they are observed only at a limited number of time points. Inference methods for such panel data have been developed for time homogeneous Markov models, but there has been little research done for other classes of processes. We develop likelihood-based methods for panel data from a semi-Markov process, where transition intensities depend on the duration of time in the current state. The proposed methods account for possible misclassification of states. To illustrate the methods, we investigate a three- and a four-state models in detail and apply the results to model the natural history of oncogenic genital human papillomavirus infections in women.

Clinical Trials as Topic↗

PubMed2006

Refusing HIV testing in an urgent care setting: results from the "Think HIV" program.

Efforts to increase HIV case identification through routine, voluntary HIV testing are hindered by high refusal rates. Our objective was to identify patients most likely to refuse routine HIV testing. We developed a new HIV testing program at four Massachusetts urgent care centers. Patients were asked if they were interested in routine HIV testing. We performed analyses to assess differences in characteristics between those who refused testing and those who accepted it. Data were available for 9129/10,354 (88%) patients offered routine HIV testing from January to December 2002. Of these 9129 patients, 67% refused testing. In the crude analysis, HIV test refusal was associated with female gender, white race, older age, and higher educational level. In multivariate analysis, non-English-speaking patients who were Hispanic, Haitian, and other race were more likely to refuse testing than their English-speaking counterparts. Among all patients, "not at risk" and "already tested" were the most common reasons for test refusal. Two thirds of patients refused routine HIV testing when it was offered in a statewide urgent care-based program. If routine HIV testing programs are to be successful, strategies must be developed to increase HIV test acceptance among patients most likely to refrain from testing.

AIDS Serodiagnosis↗

PubMed2006

Effects of HCV treatment on cytokine expression during HCV/HIV coinfection.

There is growing evidence that cytokine expression is linked to hepatitis C virus (HCV) pathogenesis and treatment response rates among HCV-monoinfected persons. However, because of the profound effects of human immunodeficiency virus (HIV) coinfection on HCV, it is not clear if these observations are also true for HCV/HIV-coinfected individuals. Serum expression of the proinflammatory cytokines interleukin-8 (IL-8) and tumor necrosis factor-alpha (TNF-alpha) and the fibrogenic cytokine transforming growth factor-beta1 (TGF-beta1) were measured in HCV/HIV-coinfected persons at baseline and at week 24 of HCV therapy. Higher levels of IL-8 and TGF-beta were demonstrated among nonwhite subjects at baseline. Increases in TNF-alpha and IL-8 expression were found at week 24 of HCV therapy, suggesting that enhanced proinflammatory cytokine production may occur during HCV treatment. However, cytokine levels were not predictive of HCV virologic, biochemical, or histologic response. Although previous studies conducted among HCV-monoinfected individuals have suggested that cytokine levels could predict the virologic response to therapy, no such associations were observed among HCV/HIV-coinfected persons, suggesting that they may respond differently to treatment than do their HCV-monoinfected counterparts.

Adult↗

PubMed2004

Evaluation of log-rank tests for infrequent observations from a multi-state process, with application to HPV vaccine efficacy.

Genital infection by human papillomavirus (HPV) is a common sexually transmitted disease, with over 25 per cent prevalence among young women in the US. Infections are usually without symptoms and transient (or reversible), but a small proportion of infections persist and are believed to be responsible for nearly all cervical cancers and precursor lesions such as cervical intraepithelial neoplasia (CIN). Therefore, successful vaccines against persistent HPV infections could have a great impact in preventing cervical cancers. In trials being planned, ongoing, and recently completed, a log-rank or a similar test may be employed to assess a vaccine effect in comparison to placebo, with an infection 'event' defined to capture persistent but not transient infections. However, it is not clear how best to define such an event, because (1) diagnostic tests cannot distinguish a persistent from a transient infection, (2) participants are only examined periodically, and (3) there can be misclassification errors in the detection of infections. This paper evaluates several definitions of persistent infection that are based on periodically observed infection statuses by postulating a multi-state model for persistent and transient infections. The type I error and the power of tests on vaccine efficacy based on these operational definitions are then examined under various scenarios of how a vaccine might affect the infection-disease process. We find that none of the candidates performs satisfactorily, thus raising concerns that clinical trials based only on infection endpoints will not be reliable.

Biometry↗

PubMed2004

Evaluating the role of human papillomavirus vaccine in cervical cancer prevention.

Persistent genital infection with human papillomavirus (HPV) is a natural candidate as a surrogate marker for cervical cancer because of the strong epidemiologic and molecular evidence that HPV infection is the causative agent for almost all cervical cancers. However, while infection with high-risk types of HPV appears to be necessary for the development of cervical cancer, most infections are controlled by host immune response and do not lead to cancer in the vast majority of infected women. Because diagnostic tests cannot distinguish a persistent infection in the pathogenesis of cervical cancer from a transient infection, it is difficult to describe the disease mechanism as a progressive process based on observations. Therefore, the disease pathogenesis pathway does not fit into the usual surrogate marker framework, raising practical concerns about using HPV infection as a surrogate for a clinical endpoint in vaccine trials. In this paper, we describe the challenges in defining HPV infection as a surrogate endpoint in a HPV vaccine trial that is aimed at reducing cervical cancer rates and examine potential effects of the vaccine. We then outline some issues in the design and analysis of HPV vaccine trials, including the use of operationally defined HPV infection events meant to capture persistent infections. We conclude with a recommendation for a multistate model that uses HPV infection to help explain the mechanisms of vaccine action rather than validate it as an endpoint substitute.

Clinical Trials as Topic↗

PubMed2003

Delusional parasitosis as 'folie a deux'.

Delusional parasitosis is characterized by the unshakeable belief of being infested with tiny (microscopic) insects. Patients spend much time trying to get rid of the bugs and suffer from these symptoms. Patients prefer to go to dermatologists because they have a strong conviction over the presence of a somatic disease and do not accept any psychiatric advice for their complaints. Folie a deux or shared psychotic disorder (SPD) is a relatively rare syndrome, which has long attracted clinical attention. Delusional parasitosis is associated in 5-15% of SPD and can run within a family. We experienced delusional parasitosis as Folie a Deux between a mother and her son and successfully treated them through early psychiatric intervention. We believe that attention should be drawn to DP with SPD.

Adult↗