Ae-Ran Kim

Enhancement of receptor-operated cation current and TRPC6 expression in arterial smooth muscle cells of deoxycorticosterone acetate-salt hypertensive rats

Objectives In deoxycorticosterone acetate (DOCA)-salt hypertensive rats, altered reactivity of blood vessels to vasoactive agonists is frequently associated with an elevation in blood pressure. Canonical transient receptor potential (TRPC) channels are believed to encode receptor-operated cation channels (ROC), the activation of which is involved in smooth muscle depolarization and vasoconstriction. The aims of the present study were to investigate whether the ROC current is increased in DOCA-hypertensive rats and determine whether aldosterone directly enhances the expression of TRPC. Methods The nystatin-perforated patch-clamp technique was used for the recording of receptor-stimulated ion currents in mesenteric arterial smooth muscle cells, which were enzymatically dispersed from sham-operated and DOCA-salt hypertensive rats. Expressions of TRPCs were evaluated by reverse transcriptase-polymerase chain reaction (RT-PCR) and by Western blot analysis. Results Receptor-stimulated currents activated by 5-hydroxytryptamine (serotonin) and norepinephrine were increased significantly in the mesenteric arterial smooth muscle cells of DOCA-salt hypertensive rats compared to sham-operated rats. Ion-substitution experiments revealed that the enhanced currents were cation currents (ROC currents). Enhanced expression of TRPC6 in mesenteric arteries from DOCA-salt hypertensive rats was demonstrated by real-time RT-PCR. Up-regulation of TRPC6 by aldosterone treatment in vitro was also observed in A7r5 cells by RT-PCR and in western blots. Conclusion These results suggest that aldosterone enhances TRPC6 expression and ROC currents in vascular smooth muscle cells, and that this may in turn contribute to altered vascular reactivity and to hypertension.

Characterization of antimicrobial resistance of recent Salmonella enterica serovar Gallinarum isolates from chickens in South Korea

Salmonella enterica serovar Gallinarum isolates (n=105) from chickens in South Korea between 2002 and 2007 were tested for antimicrobial susceptibility by determining minimum inhibitory concentrations of 16 antimicrobials, and their predominant resistance profiles were genetically characterized. Most isolates (99/105; 94.3%) were resistant to nalidixic acid and resistant/intermediately resistant to fluoroquinolones, and 63.8% (67/105) of the isolates were resistant to three or more antimicrobials. Forty-two quinolone-resistant isolates, of which the quinolone resistance-determining regions of the gyrA genes were sequenced, contained a substitution of a Ser to a Phe or Tyr at position 83 (71.4%), or a substitution of an Asp to an Asn, Gly, or Tyr at position 87 (28.6%). Fifty-seven sulphamethoxazole-resistant isolates were tested for the presence of class 1 integrons by polymerase chain reaction, and their resistance gene cassettes were analysed by sequencing. Three different class 1 integrons containing the resistance-gene insert aadA (52.6%; n=30), aadB (12.3%; n=7), or aadB-aadA (12.3%; n=7) were identified. Most isolates harbouring the integron containing aadB-aadA displayed resistance to all three aminoglycosides tested and also showed increased resistance to fluoroquinolones. These findings suggest that fluoroquinolone resistance may be epidemiologically linked to multiple aminoglycoside resistance.

Establishment of PCR Conditions for the Identification of Stenotrophomonas maltophilia Isolated from Boar Semen and Antimicrobial Susceptibility Patterns of the Isolates

Bacteria are frequently contaminated during the collection and processing procedures of boar semen. Of the contaminants, Stenotrophomonas (S.) maltophilia is a Gram-negative bacterium that is widely distributed in a variety of habitats. Although PCR assays have been developed for the detection of S. maltophilia, they cross-react with some species of Xanthomonas. In this study, we designed a primer set for the detection of S. maltophilia in order to target the chiA (GenBank accession no. NC_010943) gene. The specific PCR products were amplified from S. maltophilia only, not from other tested strains that are frequently found in semen. The detection limit of the PCR was 1.5×10³ CFU/ml with pure-cultured S. maltophilia and 1.5×10⁴ CFU/ml with S. maltophilia spiked in semen. Twenty-six (5.9%) S. maltophilia were isolated from 440 semen samples. The PCR results exhibited 98.9% agreement with a comparison of S. maltophilia isolation. Also, the sensitivity and specificity of the PCR were 100% and 98.7%, respectively. In the antimicrobial susceptibility test, S. maltophilia isolates were highly susceptible to enrofloxacin and florfenicol, while the majority of them were resistant to amoxicillin/clavulanic acid, apramycin, ceftiofur, penicillin, and spectinomycin. These results indicated that the PCR using the chiA gene was proven to be reliable and effective for the detection of S. maltophilia with high levels of sensitivity and specificity.

Capsular serotypes, virulence-associated genes and antimicrobial susceptibility of Streptococcus suis isolates from pigs in Korea

Streptococcus suis is an important pig pathogen with potential for human transmission. The serotype distributions and phenotypic characteristics vary over time and among regions; however, little is known about the characteristics of S. suis isolates in Korea. In this study, 240 S. suis isolates collected from pigs in Korea in 2009–2010 were serotyped by coagglutination tests, subsequently screened for three virulence-associated genes (mrp, epf and sly) and tested for antimicrobial susceptibility. As for 80 isolates, the serotypes of which were relevant to human infections, clonal complexes (CCs) were further identified by PCR. Serotype 3 was the most prevalent (15.8%), followed by serotype 2 (15.0%), with geographical variation for each serotype. Overall, 55.4% of the isolates carried mrp, whereas only 3.8% carried epf. CC25 was the most prevalent (41.3%) and was related to serotypes 2 and 9. The isolates showed higher susceptibility to ampicillin (93.4%) and ceftiofur (90.8%) than to the other antimicrobial agents tested. The highest resistance rate was observed to tetracycline (98.0%), followed by erythromycin (88.8%). In addition, the resistance to certain antimicrobials was significantly associated, in part, with virulence-associated genes or serotypes. Therefore, continuous characterization of S. suis is essential for the benefit of veterinary and human medicine.

Specific Detection of Serratia marcescens Based on a PCR Assay and Antimicrobial Susceptibility of S. marcescens Isolated from Boar Semen

During the collection of boar semen, bacterial contamination usually occurs. The contamination has deleterious effects both on semen quality and on sow fertility. The majority of contaminants are gram-negative bacteria, especially Serratia marcescens. In this study, we developed a PCR assay for the identification of S. marcescens targeting the luxS gene (GenBank no. EF164926). S. marcescens yielded a specific 306 bp PCR product. However, no amplification was observed in the other strains tested. The detection limit of PCR was of template DNA of S. marcescens. The antimicrobial susceptibility patterns of S. marcescens isolated from boar semen were tested using the disk diffusion method. Gentamicin, ceftiofur, florfenicol, and neomycin showed high sensitivity in this test. The minimum inhibitory concentration (MIC) was also determined by the broth microdilution method. The values of ceftiofur, enrofloxacin, gentamicin, and neomycin were 8, 8, 8, and , respectively. These results indicate that PCR amplification of the luxS gene is a reliable and effective method for the identification of S. marcescens and that ceftiofur, enrofloxacin, gentamicin, and neomycin are effective semen extenders for controlling S. marcescens.

Electroacupuncture for Painful Diabetic Peripheral Neuropathy: A Multicenter, Randomized, Assessor-Blinded, Controlled Trial

Painful diabetic peripheral neuropathy (PDN) is one of the most common complications of diabetes. In patients with PDN, greater pain intensity leads to poorer quality of life, sleep, function, and work productivity (1–3). According to the clinical practice guideline, electrical stimulation is probably effective and should be considered for the treatment of PDN (evidence level B) (4). The aim of this study is to evaluate the effectiveness and safety of electroacupuncture (EA) for the management of PDN in patients with type 2 diabetes. This multicenter, randomized, assessor-blinded, controlled trial was conducted between June 2014 and March 2016 at four centers in South Korea (clinical trial reg. no. KCT0001135, https://cris.nih.go.kr). A total of 126 participants with a ≥6-month history of PDN and a mean weekly pain score of ≥4 on the Pain Intensity Numerical Rating Scale (PI-NRS) were randomly assigned in a 1:1 ratio to an EA group ( n = 63) or control group ( n = 63). Randomization was performed by using a computer-generated random code, and allocation concealment was achieved using sequentially numbered, opaque sealed envelopes. The participants in the EA group received EA treatment with a mixed current of 2 Hz/120 Hz at 12 acupuncture points (bilateral Zusanli [ST36], Xuanzhong [GB39], Yinlingquan [SP9], Sanyinjiao [SP6], Taichong …

The Effect of Dongeui Qigong for Prehypertension and Mild Essential Hypertension

Although several previous studies have reported the effect of qigong on lowering blood pressure, rigorous trials are lacking. Studies evaluating the effect of qigong on prehypertension are also scarce. This study aimed to assess the effect of qigong on prehypertension and mild hypertension. Participants with prehypertension or mild hypertension were randomized to the Dongeui qigong group or a nontreated control group. In the qigong group, Dongeui qigong was administered 5 times/week for 12 weeks. The control group did not receive any intervention for blood pressure control. Fifty-two participants were included in this study. Even though diastolic blood pressure was significantly reduced in the qigong group after 8 weeks (p = 0.04) compared to baseline, the difference in change in blood pressure between the qigong and control groups was not significant. There were no significant differences in quality of life between the qigong and control groups. Dongeui qigong is not significantly effective in pre/mild hypertension compared with controls. This result could be due to a lack of effect of qigong or caused by other factors, such as the type of qigong, target symptoms, inappropriate sample size, and compliance of participants. Trial Registration. This trial is registered with KCT0001397 (Clinical Research Information Service).

Electroacupuncture for treating insomnia in patients with cancer: a study protocol for a randomised pilot clinical trial

Introduction Although insomnia is one of the most prevalent and disturbing symptoms among patients with cancer, it has not been properly managed. Electroacupuncture (EA) has received attention as a promising intervention for insomnia, and a few previous studies have reported that this intervention may be beneficial for treating insomnia in patients with cancer. The aim of this pilot study is to explore the feasibility and preliminary effectiveness of EA on the sleep disturbance of patients with cancer with insomnia using a subjective method, patient-reported questionnaires and an objective tool, actigraphy, to measure the quality of sleep. Methods and analysis This is a study protocol for a randomised, three-arm, multicentre, pilot clinical trial. A total of 45 patients with cancer who have continuous insomnia related to cancer treatment or cancer itself will be randomly allocated to an EA group, sham EA group or usual care group in equal proportions. The EA group will receive 10 sessions of EA treatment over 4 weeks. The sham EA group will receive sham EA at non-acupoints using non-penetrating Streitberger acupuncture needles with mock EA. The usual care group will not receive EA treatment. All participants will be provided a brochure on the management of sleep disorders regardless of their group assignment. The primary outcome measure is the mean change in the insomnia severity index from the baseline to week 5. Information related to sleep quality will also be obtained through the Pittsburgh Sleep Quality Index, a sleep diary and actigraphy. Participants will complete the trial by visiting the research centre at week 9 for follow-up assessment. Ethics and dissemination This study protocol was approved by the institutional review boards of each research centre. Written informed consent will be obtained from all participants. The result of this study will be published in peer-reviewed journals or presented at academic conferences. Trial registration number KCT0002162; Pre-results.