Eun-Min Kim

Effects of excretory/secretory products from Clonorchis sinensis and the carcinogen dimethylnitrosamine on the proliferation and cell cycle modulation of human epithelial HEK293T cells.

Clonorchis sinensis is one of the most prevalent parasitic helminths in Korea. Although cholangiocarcinoma can be induced by C. sinensis infection, the underlying mechanism is not clearly understood. To assess the role of C. sinensis infection in carcinogenesis, an in vitro system was established using the human epithelial cell line HEK293T. In cells exposed to the excretory/secretory products (ESP) of C. sinensis and the carcinogen dimethylnitrosamine (DMN), cellular proliferation and the proportion of cells in the G2/M phase increased. Moreover, the expression of the cell cycle proteins E2F1, p-pRb, and cyclin B was dramatically increased when ESP and DMN were added together. Similarly, the transcription factor E2F1 showed its highest level of activity when ESP and DMN were added simultaneously. These findings indicate that DMN and ESP synergistically affect the regulation of cell cycle-related proteins. Our results suggest that exposure to C. sinensis and a small amount of a carcinogen such as DMN can promote carcinogenesis in the bile duct epithelium via uncontrolled cellular proliferation and the upregulation of cell cycle-related proteins.

Ultrasound measurement of subglottic diameter and an empirical formula for proper endotracheal tube fitting in children

The appropriate endotracheal tube (ETT) size is commonly determined using age‐based formula; ETT size determination based on ultrasound (US) measurement of subglottic diameter (SD), the narrowest portion of the paediatric upper airway, may provide a better method for accurate fit. We aimed to validate ETT size determination using US measures of SD before intubation to establish an empirical formula for ETT fitting based on SD and biographic parameters.

Identification of a novel FAM83H mutation and microhardness of an affected molar in autosomal dominant hypocalcified amelogenesis imperfecta

AIM To determine the underlying molecular genetic aetiology of a family with the hypocalcified form of amelogenesis imperfecta and to investigate the hardness of the enamel and dentine of a known FAM83H mutation. METHODOLOGY Mutational screening of the FAM83H on the basis of candidate gene approach was performed. All exons and exon-intron boundaries was amplified and sequenced. A microhardness test was performed to measure the Vickers microhardness value. RESULTS A novel nonsense mutation (c.1354C>T, p.Q452X) was identified in the last exon of FAM83H, which resulted in soft, uncalcified enamel. The affected enamel was extremely soft (about 17% of the normal control), but the underlying dentine was as hard as the normal control. CONCLUSIONS Mutational analysis revealed a novel mutation in FAM83H gene. Hardness of dentine was not affected by the mutation, whilst the enamel was extremely soft.

Infection Status of Freshwater Fish with Metacercariae of Clonorchis sinensis in Korea

This study investigated freshwater fish for their current infection status with metacercariae of Clonorchis sinensis in Korea. Twenty-one species of freshwater fish (n = 677) were collected from 34 regions nationwidely from February 2007 to June 2008. They were individually examined by digestion technique. Eight species of freshwater fish from 17 different regions were recognized positive for the metacercariae of C. sinensis. The positive rates (range of metacercariae number per fish) of fish by the species were as follows: 48% (1-1,142) in Pseudorasbora parva, 60% (1-412) in Pungtungia herzi, 15.7% (1-23) in Pseudogobio esocinus, 29% (1-7) in Acheilognathus intermedia, 21% (1-4) in Odontobutis interrupta, 33% (1-6) in Zacco temmincki, 3.6% (1-4) in Zacco platypus, and 26.3% (1) in Hemibarbus labeo. The two species, P. parva and P. herzi, are able to be the index fish for estimation of C. sinensis transmission in a certain locality. Still several species of freshwater fish are briskly transmitting C. sinensis infection in many riverside areas of southern Korea.

Cyst formation, increased anti-inflammatory cytokines and expression of chemokines support for Clonorchis sinensis infection in FVB mice.

To verify the hypothesis that different pathology of Clonorchis sinensis infection by mouse strains is determined by different responses of cytokines and chemokines, we compared those responses of FVB with those of BALB/c mice. All of FVB mice infected with 30 metacercariae of C. sinensis showed cystic dilatation in the liver, whereas infected BALB/c mice did not. Mature worms were recovered from 19 of 20 liver sections of FVB mice while only one of 20 sections of BALB/c mice revealed a mature worm. In both strains the proportion of CD4(+) T cells was lower in C. sinensis-infected than in the uninfected group. However, the proportion of CD8(+) T cells was elevated in C. sinensis-infected from both strains compared to uninfected mice. The Th2-associated anti-inflammatory cytokines such as IL-4, IL-5 and IL-13, IL-10 and TGF-β, were significantly more produced by the lymphocytes of FVB than by those of BALB/c mice. Especially, the 2 anti-inflammatory cytokines, IL-10 and TGF-β, were presumably related with susceptibility and the development of worms in the liver. C. sinensis infected FVB mice also produced more chemokines such as RANTES and MIP-1α in the liver lymphocytes than BALB/c mice. In conclusion, the FVB mice provide the favorable niche for C. sinensis by cyst formation in the bile duct, increased production of Th2-associated anti-inflammatory cytokines and upregulation of chemokines.

Doppler ultrasound to detect pulpal blood flow changes during local anaesthesia

AIM   To examine whether Doppler ultrasound can detect changes in pulpal blood flow after infiltration anaesthesia. METHODOLOGY   Changes in pulpal blood flow in maxillary central incisor teeth of 18 patients (mean age 26.7 years, 13 men, five women) after infiltration anaesthesia were examined. Before infiltration anaesthesia, the pulpal blood flow was measured using Doppler ultrasound. A local anaesthetic solution containing 2% lidocaine with 1:80,000 epinephrine was injected into the submucosa above the experimental tooth. The Doppler ultrasound test was carried out at 5, 10, 20, 30, 45 and 60 min after infiltration. The parameters were Vas (maximum linear velocity, cm s(-1) ), Vam (average linear velocity, cm s(-1) ) and Vakd (minimum linear velocity, cm s(-1) ), which are indicators of the level of blood flow. The mixed procedure at the 95% confidence interval was used to examine the changes in pulpal blood flow after the injection. RESULTS   The linear velocity profiles (Vas, Vam, and Vakd) decreased sharply 5 min after anaesthesia and then reduced continuously for 30 min. The maximum degree of blood flow reduction in Vas, Vam and Vakd was 58%, 83% and 82%, respectively. After 30 min, the linear velocities increased gradually. The Vam returned to the pre-anaesthesia state at 60 minutes but the Vas and Vakd did not recover completely. CONCLUSIONS   Doppler ultrasound can detect changes in pulpal blood flow after infiltration anaesthesia. In the future, Doppler ultrasound can be used as a tool for measuring pulpal blood flow.

Immunohistochemical analysis of pulpal regeneration by nestin expression in replanted teeth.

AIM To investigate dental pulp healing after tooth replantation in rats using nestin as an odontoblastic marker for immunohistochemical analysis. METHODOLOGY   Twenty-five maxillary right first molars from 25 female Sprague-Dawley rats, aged 4 weeks post-natally, were extracted and immediately repositioned in the original socket within 5 s. Five rats each were later killed on days 3, 5 and weeks 1, 2 and 4. The maxillae were removed en bloc and the tissue samples containing the maxillary right first molars were decalcified, sectioned, mounted and stained with anti-nestin antibody to be observed under a light microscope. RESULTS   At 3 days after replantation, there was a localized inflammatory reaction, but pulp revascularization and healing had begun in the root area. At 5 days after replantation, odontoblast-like cells were observed. Reparative dentine deposition was observed beneath the pulp-dentine border from 1 week after replantation, and gradually increased until 2 weeks after replantation. The presence of odontoblast-like cells and the formation of reparative dentine continued from the first week throughout the experimental period. At week four, deposition of osteodentine and cementum-like tissues were observed. CONCLUSIONS Pulpal mineralization after replantation initially occurred via the deposition of reparative dentine, followed by the deposition of osteodentine and cementum-like tissues in rat teeth.

Local immune response to primary infection and re-infection by Clonorchis sinensis in FVB mice.

Although Clonorchis sinensis lives in the bile duct, few studies have investigated the local immune response in the liver and bile duct. To investigate the local immune response to C. sinensis, we investigated the activation and recruitment of various immune cells and cytokine levels in the liver and bile duct lymph nodes (BLN) in FVB mice after primary infection and re-infection. Male 4-week-old FVB mice were divided into 6 experimental groups: uninfected controls, primary infection lasting 1week (PI 1w), primary infection lasting 4weeks (PI 4w), praziquantel treatment after PI 4w (Tx), re-infection lasting 1week after Tx (RI 1w), and re-infection lasting 4weeks after Tx (RI 4w). Recovery rates were 80.0% and 73.0% in PI 1w and PI 4w mice, respectively, but significantly decreased during re-infection to 26.6% in RI 1w and 13.3% in RI 4w. This result suggested that the mice were resistant to re-infection. In the liver, Kupffer cells were augmented 70-fold in PI 1w mice (P<0.001). Kupffer cells expressed Th2-related cytokines (IL-10 and IL-13) during primary infection. In addition, serum levels of C. sinensis-specific IgG1 and IgG2a strongly increased in RI 1w mice. Secretion of C. sinensis-specific IgE reached a plateau at 4weeks after primary infection, and remained elevated in all infected groups. In conclusion, during infection with C. sinensis, Kupffer cells likely act as antigen-presenting cells, stimulating the Th2 cytokine production system.

Clonorchis sinensis antigens alter hepatic macrophage polarization in vitro and in vivo

Clonorchis sinensis infection elicits hepatic inflammation, which can lead to cholangitis, periductal hepatic fibrosis, liver cirrhosis, and even cholangiocarcinoma. Hepatic macrophages are an intrinsic element of both innate and acquired immunity. This study was conducted to demonstrate the dynamics of hepatic macrophage polarization during C. sinensis infection in mice and to identify factors regulating this polarization. Treatment of hepatic macrophages isolated from normal mice with C. sinensis excretory/secretory products (ESPs) resulted in the preferential generation of classically activated hepatic macrophages (M1 macrophages) and the production of pro-inflammatory cytokines. Additionally, cells stimulated with C. sinensis ESPs exhibited changes in cellular morphology. During the early stages of C. sinensis infection, hepatic macrophages preferentially differentiated into M1 macrophages; however, during the C. sinensis mature worm stage, when eggs are released, there were significant increases in the abundance of both M1 macrophages and alternatively activated hepatic macrophages (M2 macrophages). Moreover, there was a further increase in the M2 macrophage count during the fibrotic and cirrhotic stage of infection. Notably, this fibrotic and cirrhotic stage promoted a strong increase in the proportion of Arg-1-producing macrophages (M2 phenotype), which were associated with fibrosis and tissue repair in the liver. Our results suggest that the dynamic polarization of hepatic macrophages as C. sinensis infection progresses is related to the histological lesions present in liver tissue. Hepatic macrophages thus play an important role in local immunity during C. sinensis infection.

Effect‐site concentration of remifentanil for attenuating QTc interval prolongation following intubation in hypertensive female patients

Haemodynamic changes after sympathetic stimuli like tracheal intubation are more pronounced in hypertensive patients than in normotensive patients. Heart rate (HR)‐corrected QT (QTc) interval changes related to intubation may also be more prominent in hypertensive patients. We hypothesised that there would be a difference in the effect‐site concentration (Ce) of remifentanil to attenuate QTc interval prolongation in normotensive and hypertensive patients following intubation.