• The Journal of the Korean Society for Microbiology
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• v.35 no.2
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• pp.181-190
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• 2000

To investigate resistance to lamivudine (3TC), we examined the incidence of M184V in 20 HIV-1 patients treated with 3TC for $13.1{\pm}9$ months. Fourteen of 20 patients had been exposed to zidovudine (ZDV) or didanosine (ddI) prior to 3TC therapy. Nested PCR targeting to reverse transcriptase (RT) and direct sequencing were performed for peripheral blood mononuclear cells sampled serially. There were resistance mutations to ZDV in at least 9 patients at baseline, although there was no resistance mutation to 3TC. We could detect M184V in 6 (30%) out of 20 patients. The incidence of M184V increased as the duration of therapy prolongs (13% in samples <12 months; 47% in samples ${\ge}12$ months). The frequency of mutation M184V was higher in patients with previous mutation to ZDV than in patients with wild type. Resistance mutation was not detected in 7 patients. This study shows that resistance to 3TC tends to develop rapidly in patients with baseline mutations or two drugs combination therapy than in those treated simultaneously with triple drugs. This report is the first on resistance to 3TC in Korean AIDS patients.

• Journal of Microbiology
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• v.44 no.4
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• pp.453-456
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• 2006

16 chicken isolates and four clinical isolates of VanB-vanA incongruent vancomycinresistant Enterococcus faecium strains without vanS were isolated in 1999. Pulsed-field gel electrophoresis revealed only a peripheral relationship between the chicken isolates and clinical isolates, but suggested clonal spread in the chicken isolates.

• Biomolecules & Therapeutics
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• v.25 no.5
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• pp.490-496
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• 2017

Imatinib resistance has become a major clinical problem for chronic myeloid leukemia. The aim of the present study was to investigate the involvement of MEG3, a lncRNA, in imatinib resistance and demonstrate its underlying mechanisms. RNAs were extracted from CML patients' peripheral blood cells and human leukemic K562 cells, and the expression of MEG3 was measured by RT-qPCR. Cell proliferation and cell apoptosis were evaluated. Western blotting was used to measure the protein expression of several multidrug resistant transporters. Luciferase reporter assay was performed to determine the binding between MEG3 and miR-21. Our results showed that MEG3 was significantly decreased in imatinib-resistant CML patients and imatinib-resistant K562 cells. Overexpression of MEG3 in imatinib-resistant K562 cells markedly decreased cell proliferation, increased cell apoptosis, reversed imatinib resistance, and reduced the expression of MRP1, MDR1, and ABCG2. Interestingly, MEG3 binds to miR-21. MEG3 and miR-21 were negatively correlated in CML patients. In addition, miR-21 mimics reversed the phenotype of MEG3-overexpression in imatinib-resistant K562 cells. Taken together, MEG3 is involved in imatinib resistance in CML and possibly contributes to imatinib resistance through regulating miR-21, and subsequent cell proliferation, apoptosis and expression of multidrug resistant transporters.

• Preventive Nutrition and Food Science
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• v.9 no.4
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• pp.367-373
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• 2004

The prevalence of type-2 diabetes increases remarkably in post-menopausal women, possibly because insulin secretion fails to compensate for the insulin resistance induced in various tissues by estrogen insufficiency. However, this has not been fully defined. Therefore, the present study investigated whether an ovariectomy (OVX) would increase insulin resistance and decrease the $\beta$-cell function and mass in female rats with and without a $90\%$ pancreatectomy (Px). Female rats aged 15 weeks were divided into four groups: 1) OVX + Px, 2) SOVX (sham operation of OVX) + Px, 3) OVX + SPx (sham operation of Px), and 4) SOVX + SPx, and given a $30\%$ fat diet for 8 weeks. At the end of the experimental period, the islet function and insulin resistance were determined using a hyperglycemic clamp and a euglycemic hyperinsulinemic clamp, respectively. The OVX only increased the body weight in the SPx rats, which was partially related to the food intake. Yet, the OVX did increase the peripheral insulin resistance, while the Px increased this resistance further. The OVX and Px both exacerbated the islet function, as measured by the insulin secretion pattern, while delaying and decreasing the first-phase insulin secretion. The OVX only decreased the proliferation of $\beta$-cells in the Px rats, while increasing apoptosis in both the Px and SPx rats. As a result, the OVX decreased the $\beta$-cell mass in the Px rats, but increased the mass in the SPx rats. In conclusion, an OVX was found to accelerate the development and progression of diabetes by increasing the insulin resistance and decreasing the $\beta$-cell mass. Therefore, menopause can be a risk factor for type-2 diabetes, mainly due to a deceased proliferation of $\beta$-cells.

• Journal of Digital Convergence
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• v.13 no.9
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• pp.515-521
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• 2015

In this study, we tried to analyze arterial stiffness of Jeju female divers who diver into cold water without the assistance of oxygen. For this purpose we measured pulse wave velocity and ankle-brachial index of Jeju female divers and same aged females who didn't have any cardiovascular risk for comparing the vascular stiffness. The results were the following : First, the light-femoral pulse wave velocity of Jeju female divers was significantly lower than normal women of the same ages. Second, Jeju female divers's ABI showed higher tendency than normal same aged women. These result showed that Jeju female divers' body had been completed for adaptation to low temperature and high pressure water environment through a long-term immersion activities in old age, as well as due to higher physical activity levels of Jeju female divers peripheral vascular resistance was not reduced.

• The Korean Journal of Physiology
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• v.21 no.2
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• pp.211-223
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• 1987

Head-down tilt (HDT) at $-6^{\circ}$ has been commonly used as the experimental model in both man and animals to induce the blood shift toward the head or central protion of the body, demonstrating similar physiological effect encountered in the weightlessness in the orbital flight. There are few reports about the physiological response upon the cardiovascular regulatory system or the tolerance to the $(-6^{\circ})$ HDT within a relatively short period less than 1 hour. Therefore, the purpose of this study way to observe the effects of $-6^{\circ}$ HDT on cardiovascular system within 30 minutes and to evaluate early regulatory mechanism for simulated hypogravity. Ten mongrel dogs weighing 8-12 kg were anesthetized with the infusion of 1% ${\alpha}-chloralose$ (100 mg/kg) intravenously, and the postural changes were performed from the supine to the $-6^{\circ}$ head-down Position, then from the head-down to the supine (SUP), and each posture was maintained for 30 minutes. Blood flow $({\dot{Q}})$ through common carotid and femoral arteries were determined by the electromagnetic flowmeter. Mean arterial pressure (MAP), heart rate (HR), respiratory rate , and pH, $P_{O_2}$, $P_{CO_2}$ and hematocrit (Hct) of arterial and venous blood were also measured. The peripheral vascular resistance was calculated by dividing respective MAP values by ${\dot{Q}}$ through both sides of common carotid or femoral arteries. The concentration of plasma epinephrine and norepinephrine was determined by Peuler & Johnson's radioenzymatic method. The results are summarized as follows: In the initial 5 minutes in $-6^{\circ}$ HDT, HR was significantly (p<0.05) increased and MAP slightly decreased. Although ${\dot{Q}}$ and carotid peripheral artery resistance were not significantly changed, ${\dot{Q}}$ through femoral artery was diminished and femoral peripheral artery resistance was elevated. In the SUP, the initial changes of MAP and HR were increased (p<0.05), but those of ${\dot{Q}}$ and peripheral vascular resistance through both common carotid and femoral arteries were not significant. After 10 minutes of each postural change in both HDT and SUP, MAP was maintained almost equal to that of the level of pretilting control. During 60 minutes of both postural changes of HDT and SUP, $P_{O_2}$ and Hct were not changed significantly. However pH tended to increase slowly and $P_{CO_2}$ was gradually decreased. The pH and $P_{CO_2}$ seemed to be related to the increased respiratory rate. Plasma epinephrine concentration was not changed significantly and plasma norepinephrine concentration was slightly decreased in the course of HDT and also at 10 minutes of SUP. However these concentration changes were statistically insignificant. From these results, it may be concluded that the effect of $-6^{\circ}$ HDT for 30 minutes on the cardiovascular system and plasma catecholamine levels of the dog is minimum and it is suggestive that the cardiovascular regulatory mechanism, possibly mediated by so called gravity receptors including baroreceptor and volume receptor, has been properly and adequately operated.

• Korean Journal of Biological Psychiatry
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• v.23 no.2
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• pp.37-40
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• 2016

Treatment-resistant depression (TRD) is a major public health problem. It is estimated that about 30% of patients with major depressive disorder do not show substantial clinical improvement to somatic or psychosocial treatment. Most of studies for TRD have focused on the subjects already known as TRD. Patients with unipolar depressive episodes that do not respond satisfactorily to numerous sequential treatment regimens were included in the TRD studies. Such post hoc experimental design can be regarded only as consequences of having TRD, rather than as causal risk factors for it. Although informative, data derived from such studies often do not allow a distinction to be made between cause and effect. So, we should shift paradigm toward examining the risk for developing TRD in untreated depressed patients. To deal with this problem, untreated depressed patients should be enrolled in the study to identify biological markers for treatment resistance. The peripheral or central biological markers should be explored before starting treatment. Subsequent systematic administration of treatments with appropriate monitoring in the subjects can determine the risk for developing treatment resistance in untreated individuals. Such information could give a cue to improve the initial diagnosis and provide more effective treatment for TRD.

• The Korean journal of helicobacter and upper gastrointestinal research
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• v.18 no.3
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• pp.157-161
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• 2018

Liquid biopsy, the analysis of circulating biomarkers from peripheral blood, such as circulating tumor cells (CTCs) and circulating tumor DNA, and exosomes, offers a less invasive, new source of cancer-derived materials that may reflect the status of the disease better and thereby contribute to personalized treatment. Recent advances in microfluidics and molecular analysis technologies have resulted in greatly improved CTC enumeration and detection. In this article, we review commercially available technologies used to isolate CTCs from peripheral blood, including immunoaffinity and label-free, physical property-based isolation methods. Although enormous technological progress has been made, especially within the last decade, only a few CTC detection methods have been approved for routine clinical use. Here, we provide an overview of the current CTC isolation methods and examples of their potential application for early diagnosis, prognosis, treatment monitoring, and prediction of resistance to cancer therapy. Furthermore, the challenges that remain to be addressed before such tools are implemented for routine use in clinical settings are discussed.

• Asian Pacific Journal of Cancer Prevention
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• v.14 no.9
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• pp.5489-5494
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• 2013

In the current study we aimed to show the common YMDD motif mutations in viral polymerase gene in chronic hepatitis B patients during lamivudine and adefovir therapy. Forty-one serum samples obtained from chronic hepatitis B patients (24 male, 17 female; age range: 34-68 years) were included in the study. HBV-DNA was extracted from the peripheral blood of the patients using an extraction kit (Invisorb, Instant Spin DNA/RNA Virus Mini Kit, Germany). A line probe assay and direct sequencing analyses (INNO-LIPA HBV DR v2; INNOGENETICS N.V, Ghent, Belgium) were applied to determine target mutations of the viral polymerase gene in positive HBV-DNA samples. A total of 41 mutations located in 21 different codons were detected in the current results. In 17 (41.5%) patients various point mutations were detected leading to lamivudin, adefovir and/or combined drug resistance. Wild polymerase gene profiles were detected in 24 (58.5%) HBV positive patients of the current cohort. Eight of the 17 samples (19.5%) having rtM204V/I/A missense transition and/or transversion point mutations and resistance to lamivudin. Six of the the mutated samples (14.6%) having rtL180M missense transversion mutation and resistance to combined adefovir and lamivudin. Three of the mutated samples (7.5%) having rtG215H by the double base substituation and resistance to adefovir. Three of the mutated samples (7.5%) having codon rtL181W due to the missense transversion point mutations and showed resistance to combined adefovir and lamivudin. Unreported novel point mutations were detected in the different codons of polymerase gene region in the current HBV positive cohort fromTurkish population. The current results provide evidence that rtL180M and rtM204V/I/A mutations of HBV-DNA may be associated with a poor antiviral response and HBV chronicity during conventional therapy in Turkish patients.

• IMMUNE NETWORK
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• v.12 no.3
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• pp.96-103
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• 2012

Obesity-induced disorders contribute to the development of metabolic diseases such as insulin resistance, fatty liver diseases, and type 2 diabetes (T2D). In this study, we evaluated whether the Aloe QDM complex could improve metabolic disorders related to blood glucose levels and insulin resistance. Male C57BL/6 obese mice fed a high-fat diet for 54 days received a supplement of Aloe QDM complex or pioglitazone (PGZ) or metformin (Met) and were compared with unsupplemented controls (high-fat diet; HFD) or mice fed a regular diet (RD). RT-PCR and western blot analysis were used to quantify the expression of obesity-induced inflammation. Dietary Aloe QDM complex lowered body weight, fasting blood glucose, plasma insulin, and leptin levels, and markedly reduced the impairment of glucose tolerance in obese mice. Also, Aloe QDM complex significantly enhanced plasma adiponectin levels and insulin sensitivity via AMPK activity in muscles. At the same time, Aloe QDM decreased the mRNA and protein of $PPAR{\gamma}/LXR{\alpha}$ and scavenger receptors in white adipose tissue (WAT). Dietary Aloe QDM complex reduces obesity-induced glucose tolerance not only by suppressing $PPAR{\gamma}/LXR{\alpha}$ but also by enhancing AMPK activity in the WAT and muscles, both of which are important peripheral tissues affecting insulin resistance. The Aloe QDM complex could be used as a nutritional intervention against T2D.