Balancing act: BRCA2's elaborate management of telomere replication through control of G-quadruplex dynamicity.

In billion years of evolution, eukaryotes preserved the chromosome ends with arrays of guanine repeats surrounded by thymines and adenines, which can form stacks of four-stranded planar structure known as G-quadruplex (G4). The rationale behind the evolutionary conservation of the G4 structure at the telomere remained elusive. Our recent study has shed light on this matter by revealing that telomere G4 undergoes oscillation between at least two distinct folded conformations. Additionally, tumor suppressor BRCA2 exhibits a unique mode of interaction with telomere G4. To elaborate, BRCA2 directly interacts with G-triplex (G3)-derived intermediates that form during the interconversion of the two different G4 states. In doing so, BRCA2 remodels the G4, facilitating the restart of stalled replication forks. In this review, we succinctly summarize the findings regarding the dynamicity of telomeric G4, emphasize its importance in maintaining telomere replication homeostasis, and the physiological consequences of losing G4 dynamicity at the telomere.

Exosomes Derived from Hypertrophic Scar Fibroblasts Suppress Melanogenesis in Normal Human Epidermal Melanocytes.

Post-burn hypertrophic scars often exhibit abnormal pigmentation. Exosomes play important roles in maintaining normal physiological homeostasis and in the pathological development of diseases. This study investigated the effects of the exosomes derived from hypertrophic scar fibroblasts (HTSFs) on melanocytes, which are pigment-producing cells. Normal fibroblasts (NFs) and HTSFs were isolated and cultured from normal skin and hypertrophic scar (HTS) tissue. Both the NF- and HTSF-exosomes were isolated from a cell culture medium and purified using a column-based technique. The normal human epidermal melanocytes were treated with both exosomes at a concentration of 100 µg/mL at different times. The cell proliferation, melanin content in the medium, apoptotic factors, transcription factors, melanin synthesis enzymes, signaling, signal transduction pathways, and activators of transcription factors (STAT) 1, 3, 5, and 6 were investigated. Compared with the Dulbecco's phosphate-buffered saline (DPBS)-treated controls and NF-exosomes, the HTSF-exosomes decreased the melanocyte proliferation and melanin secretion. The molecular patterns of apoptosis, proliferation, melanin synthesis, Smad and non-Smad signaling, and STATs were altered by the treatment with the HTSF-exosomes. No significant differences were observed between the DPBS-treated control and NF-exosome-treated cells. HTSF-derived exosomes may play a role in the pathological epidermal hypopigmentation observed in patients with HTS.

Genetic assessment of pathogenic germline alterations in lysosomal genes among Asian patients with pancreatic ductal adenocarcinoma.

BACKGROUND: Lysosomes are closely linked to autophagic activity, which plays a vital role in pancreatic ductal adenocarcinoma (PDAC) biology. The survival of PDAC patients is still poor, and the identification of novel genetic factors for prognosis and treatment is highly required to prevent PDAC-related deaths. This study investigated the germline variants related to lysosomal dysfunction in patients with PDAC and to analyze whether they contribute to the development of PDAC. METHODS: The germline putative pathogenic variants (PPV) in genes involved in lysosomal storage disease (LSD) was compared between patients with PDAC (n = 418) and healthy controls (n = 845) using targeted panel and whole-exome sequencing. Furthermore, pancreatic organoids from wild-type and KrasG12D mice were used to evaluate the effect of lysosomal dysfunction on PDAC development. RNA sequencing (RNA-seq) analysis was performed with established PDAC patient-derived organoids (PDOs) according to the PPV status. RESULTS: The PPV in LSD-related genes was higher in patients with PDAC than in healthy controls (8.13 vs. 4.26%, Log2 OR = 1.65, P = 3.08 × 10-3). The PPV carriers of LSD-related genes with PDAC were significantly younger than the non-carriers (mean age 61.5 vs. 65.3 years, P = 0.031). We further studied a variant of the lysosomal enzyme, galactosylceramidase (GALC), which was the most frequently detected LSD variant in our cohort. Autophagolysosomal activity was hampered when GALC was downregulated, which was accompanied by paradoxically elevated autophagic flux. Furthermore, the number of proliferating Ki-67+ cells increased significantly in pancreatic organoids derived from Galc knockout KrasG12D mice. Moreover, GALC PPV carriers tended to show drug resistance in both PDAC cell line and PDAC PDO, and RNA-seq analysis revealed that various metabolism and gene repair pathways were upregulated in PDAC PDOs harboring a GALC variant. CONCLUSIONS: Genetically defined lysosomal dysfunction is frequently observed in patients with young-onset PDAC. This might contribute to PDAC development by altering metabolism and impairing autophagolysosomal activity, which could be potentially implicated in therapeutic applications for PDAC.

Sex differences in the skin microbiome of burn scars.

Sex differences are observed in various spectrums of skin diseases, and there are differences in wound healing rate. Herein, sex differences were identified for the newly healed skin microbiome of burn patients. Fifty-two skin samples (26 normal skin, 26 burn scars) were collected from 26 burn patients (12 male, 14 female) and microbiota analysis was performed. The correlation between skin microbiota and biomechanical properties of burn scars was also investigated. There were no significant differences in clinical characteristics between male and female patients. Considering the biomechanical properties of burn scars and normal skin around it performed before sample collection, the mean erythema level of men's normal skin was significantly higher than that of women, whereas the mean levels of melanin, transepidermal water loss and skin hydration showed no significant sex differences. The erythrocyte sedimentation rate was significantly higher in females than that in males. Alpha diversity showed no significant differences between normal skin and burn scars in the male group. However, the scar was significantly higher than that of normal skin in the female group. Microbial network analysis revealed that the male group had more complex microbial network than the female group. Additionally, in the male group, the edge density and clustering coefficient were higher in burn scars when compared to normal skin, than the female group. There were sex differences in the results of microbiome of normal skin and burn scars. Some of the altered microbiota have been correlated with the biomechanical properties of burn scars. In conclusion, sex difference in the burn scar microbiome was confirmed. These results suggest that burn treatment strategies should vary with sex.

Effects of Factors Influencing Scar Formation on the Scar Microbiome in Patients with Burns.

Skin microbiome dysbiosis has deleterious effects, and the factors influencing burn scar formation, which affects the scar microbiome composition, are unknown. Therefore, we investigated the effects of various factors influencing scar formation on the scar microbiome composition in patients with burns. We collected samples from the burn scar center and margin of 40 patients with burns, subgrouped by factors influencing scar formation. Scar microbiome composition-influencing factors were analyzed using univariate and multivariate analyses. Skin graft, hospitalization period, intensive care unit (ICU) admission, burn degree, sex, age, total body surface area burned (TBSA), time post-injury, transepidermal water loss, the erythrocyte sedimentation rate, and C-reactive protein levels were identified as factors influencing burn scar microbiome composition. Only TBSA and ICU admission were associated with significant differences in alpha diversity. Alpha diversity significantly decreased with an increase in TBSA and was significantly lower in patients admitted to the ICU than in those not admitted to the ICU. Furthermore, we identified microorganisms associated with various explanatory variables. Our cross-sectional systems biology study confirmed that various variables influence the scar microbiome composition in patients with burns, each of which is associated with various microorganisms. Therefore, these factors should be considered during the application of skin microbiota for burn scar management.

Effect of Hypertrophic Scar Fibroblast-Derived Exosomes on Keratinocytes of Normal Human Skin.

Epidermal keratinocytes are highly activated, hyper-proliferated, and abnormally differentiated in the post-burn hypertrophic scar (HTS); however, the effects of scar fibroblasts (SFs) on keratinocytes through cell-cell interaction in HTS remain unknown. Here, we investigated the effects of HTSF-derived exosomes on the proliferation and differentiation of normal human keratinocytes (NHKs) compared with normal fibroblasts (NFs) and their possible mechanism to provide a reference for clinical intervention of HTS. Fibroblasts were isolated and cultured from HTS and normal skin. Both HTSF-exosomes and NF-exosomes were extracted via a column-based method from the cell culture supernatant. NHKs were treated for 24 or 48 h with 100 µg/mL of cell-derived exosomes. The expression of proliferation markers (Ki-67 and keratin 14), activation markers (keratins 6, 16, and 17), differentiation markers (keratins 1 and 10), apoptosis factors (Bax, Bcl2, caspase 14, and ASK1), proliferation/differentiation regulators (p21 and p27), and epithelial-mesenchymal transition (EMT) markers (E-cadherin, N-cadherin, and vimentin) was investigated. Compared with NF-exosomes, HTSF-exosomes altered the molecular pattern of proliferation, activation, differentiation, and apoptosis, proliferation/differentiation regulators of NHKs, and EMT markers differently. In conclusion, our findings indicate that HTSF-derived exosomes may play a role in the epidermal pathological development of HTS.

Exosomes derived from human hypertrophic scar fibroblasts induces smad and TAK1 signaling in normal dermal fibroblasts.

Post-burn hypertrophic scars are characterized by excessive accumulation of extracellular matrix secreted by fibroblasts. Exosomes are membrane lipid extracellular vesicles that play a pivotal role in cellular communication. Previous studies revealed the role of stem cell-derived exosomes in repairing damaged tissues, and also showed that cancer cell-derived exosomes could affect the disease pathogenesis. However, the functional properties of exosomes derived from hypertrophic scar fibroblasts (HTSFs) have not yet been studied extensively. In this study, we aimed to investigate whether HTSFs-derived exosomes can change the fibrosis-related signaling pathways in human normal fibroblasts (HNFs). HTSFs and HNFs were isolated from human hypertrophic scar tissues. HTSFs-derived exosomes were extracted and treated to HNFs. Reverse transcription-quantitative polymerase chain reaction and western blotting were used to detect mRNA and protein expression, respectively, and cell proliferation and mobility were also assessed. Exosome treatment markedly increased cell proliferation and migration, and induced small mother against decapentaplegic (SMAD) signaling by increasing the levels of phosphorylated SMAD2 and SMAD1/5/8. The levels of TAK1 signaling components were also increased after exosome treatment to HNFs, including phosphorylated TAK1, p38, ERK, and JNK. HTSFs-derived exosomes further induced the epithelial-mesenchymal transition by decreasing the expression level of E-cadherin and increasing the expression levels of N-cadherin and vimentin. Consequently, the expression levels of fibronectin, type Ⅰ collagen, and type Ⅲ collagen were increased. Our results demonstrate the fibrotic property of HTSFs-derived exosomes, which suggests a potential functional role in hypertrophic scar development and a new therapeutic target.

Sirtinol Supresses Trophozoites Proliferation and Encystation of Acanthamoeba via Inhibition of Sirtuin Family Protein.

The encystation of Acanthamoeba leads to the development of metabolically inactive and dormant cysts from vegetative trophozoites under unfavorable conditions. These cysts are highly resistant to anti-Acanthamoeba drugs and biocides. Therefore, the inhibition of encystation would be more effective in treating Acanthamoeba infection. In our previous study, a sirtuin family protein-Acanthamoeba silent-information regulator 2-like protein (AcSir2)-was identified, and its expression was discovered to be critical for Acanthamoeba castellanii proliferation and encystation. In this study, to develop Acanthamoeba sirtuin inhibitors, we examine the effects of sirtinol, a sirtuin inhibitor, on trophozoite growth and encystation. Sirtinol inhibited A. castellanii trophozoites proliferation (IC50=61.24 µM). The encystation rate of cells treated with sirtinol significantly decreased to 39.8% (200 µM sirtinol) after 24 hr of incubation compared to controls. In AcSir2-overexpressing cells, the transcriptional level of cyst-specific cysteine protease (CSCP), an Acanthamoeba cysteine protease involved in the encysting process, was 11.6- and 88.6-fold higher at 48 and 72 hr after induction of encystation compared to control. However, sirtinol suppresses CSCP transcription, resulting that the undegraded organelles and large molecules remained in sirtinol-treated cells during encystation. These results indicated that sirtinol sufficiently inhibited trophozoite proliferation and encystation, and can be used to treat Acanthamoeba infections.

CPEB1 or CPEB4 knockdown suppresses the TAK1 and Smad signalings in THP-1 macrophage-like cells and dermal fibroblasts.

Post-burn hypertrophic scar (HTS) is a form of excessive dermal fibrosis characterized by cutaneous scarring, which is common in patients following burn injury. Moreover, at least 50% of HTS are accompanied by inflammation. Cytoplasmic polyadenylation element binding (CPEB) proteins are key mRNA-binding proteins that control the translation of several mRNAs. However, their potential roles in treating dermal fibrosis and scarring remain unknown. Therefore, in this study, we aimed to investigate the effects of small interfering RNA (siRNA)-mediated knockdown of CPEB1 or CPEB4 in human THP-1 macrophages and dermal fibroblasts treated with LPS and TGF-ß1. We found significantly increased CPEB1 and CPEB4 mRNA and protein levels in LPS-treated THP-1 cells and TGF-ß1-treated fibroblasts. CPEB1 and CPEB4 knockdowns suppressed LPS-activated TAK1 signaling cascades by reducing the levels of TNF-α and phosphorylated TAK1, p38, ERK, JNK, and NF-κB-p65 in THP-1 cells. CPEB1 and CPEB4 knockdowns also attenuated TGF-ß1-activated Smad-dependent and -independent signaling cascades by reducing the levels of TAK1, p38, ERK, JNK, and phosphorylated Smad 2 and Smad 1/5/8 in fibroblasts. Furthermore, CPEB1 or CPEB4 knockdown markedly decreased the levels of fibrosis markers, including α-SMA, type I collagen, and fibronectin in fibroblasts. Our findings indicate that CPEB1 and CPEB4 are involved in the regulation of the TAK1 and Smad signalings in human macrophages and dermal fibroblasts. These activities may play a role in cutaneous scarring responses.

Effect of Combining Low Temperature Plasma, Negative Pressure Wound Therapy, and Bone Marrow Mesenchymal Stem Cells on an Acute Skin Wound Healing Mouse Model.

Low-temperature plasma (LTP; 3 min/day), negative pressure wound therapy (NPWT; 4 h/day), and bone marrow mesenchymal stem cells (MSCs; 1×106 cells/day) were used as mono- and combination therapy in an acute excisional skin wound-healing ICR mouse model. These therapies have been beneficial in treating wounds. We investigated the effectiveness of monotherapy with LTP, NPWT, and MSC and combination therapy with LTP + MSC, LTP + NPWT, NPWT + MSC, and LTP + NPWT + MSC on skin wounds in mice for seven consecutive days. Gene expression, protein expression, and epithelial thickness were analyzed using real time polymerase chain reaction (RT-qPCR), western blotting, and hematoxylin and eosin staining (H&E), respectively. Wound closure was also evaluated. Wound closure was significantly accelerated in monotherapy groups, whereas more accelerated in combination therapy groups. Tumor necrosis factor-α (TNF-α) expression was increased in the LTP monotherapy group but decreased in the NPWT, MSC, and combination therapy groups. Expressions of vascular endothelial growth factor (VEGF), α-smooth muscle actin (α-SMA), and type I collagen were increased in the combination therapy groups. Re-epithelialization was also considerably accelerated in combination therapy groups. Our findings suggest that combination therapy with LPT, NPWT, and MSC exert a synergistic effect on wound healing, representing a promising strategy for the treatment of acute wounds.

Extracorporeal Shock Wave Therapy Alters the Expression of Fibrosis-Related Molecules in Fibroblast Derived from Human Hypertrophic Scar.

Extracorporeal shock wave therapy (ESWT) considerably improves the appearance and symptoms of post-burn hypertrophic scars (HTS). However, the mechanism underlying the observed beneficial effects is not well understood. The objective of this study was to elucidate the mechanism underlying changes in cellular and molecular biology that is induced by ESWT of fibroblasts derived from scar tissue (HTSFs). We cultured primary dermal fibroblasts derived from human HTS and exposed these cells to 1000 impulses of 0.03, 0.1, and 0.3 mJ/mm². At 24 h and 72 h after treatment, real-time PCR and western blotting were used to detect mRNA and protein expression, respectively, and cell viability and mobility were assessed. While HTSF viability was not affected, migration was decreased by ESWT. Transforming growth factor beta 1 (TGF-ß1) expression was reduced and alpha smooth muscle actin (α-SMA), collagen-I, fibronectin, and twist-1 were reduced significantly after ESWT. Expression of E-cadherin was increased, while that of N-cadherin was reduced. Expression of inhibitor of DNA binding 1 and 2 was increased. In conclusion, suppressed epithelial-mesenchymal transition might be responsible for the anti-scarring effect of ESWT, and has potential as a therapeutic target in the management of post-burn scars.

Molecular and Biochemical Properties of a Cysteine Protease of Acanthamoeba castellanii.

Acanthamoeba spp. are free-living protozoa that are opportunistic pathogens for humans. Cysteine proteases of Acanthamoeba have been partially characterized, but their biochemical and functional properties are not clearly understood yet. In this study, we isolated a gene encoding cysteine protease of A. castellanii (AcCP) and its biochemical and functional properties were analyzed. Sequence analysis of AcCP suggests that this enzyme is a typical cathepsin L family cysteine protease, which shares similar structural characteristics with other cathepsin L-like enzymes. The recombinant AcCP showed enzymatic activity in acidic conditions with an optimum at pH 4.0. The recombinant enzyme effectively hydrolyzed human proteins including hemoglobin, albumin, immunoglobuins A and G, and fibronectin at acidic pH. AcCP mainly localized in lysosomal compartment and its expression was observed in both trophozoites and cysts. AcCP was also identified in cultured medium of A. castellanii. Considering to lysosomal localization, secretion or release by trophozoites and continuous expression in trophozoites and cysts, the enzyme could be a multifunctional enzyme that plays important biological functions for nutrition, development and pathogenicity of A. castellanii. These results also imply that AcCP can be a promising target for development of chemotherapeutic drug for Acanthamoeba infections.

Low temperature plasma induces angiogenic growth factor via up-regulating hypoxia-inducible factor 1α in human dermal fibroblasts.

Numerous studies on the application of low temperature plasma (LTP) have produced impressive results, including antimicrobial, antitumor, and wound healing effects. Although LTP research has branched out to include medical applications, the detailed effects and working mechanisms of LTP on wound healing have not been fully investigated. Here, we investigated the potential effect of inducing growth factor after exposure to LTP and demonstrated the increased expression of angiogenic growth factor mediated by LTP-induced HIF1α expression in primary cultured human dermal fibroblasts. In cell viability assays, fibroblast viability was reduced 6 h and 24 h after LTP treatment for only 5 min, and pre-treating with NAC, a ROS scavenger, prevented cell loss. Fibroblast migration significantly increased at 6 h and 24 h in scratch wound healing assays, the expression of cytokines significantly changed, and regulatory growth factors were induced at 6 h and 24 h after exposure to LTP in RT-PCR or ELISAs. Specifically, LTP treatment significantly induced the expression of HIF1α, an upstream regulator of angiogenesis. Pre-treatment with the inhibitor CAY10585 abolished HIF1α expression and prevented LTP-induced angiogenic growth factor production according to immunoblotting, immunocytochemistry, and ELISA results. Taken together, our results provide information on the molecular mechanism by which LTP application may promote angiogenesis and will aid in developing methods to improve wound healing.

Investigation of cognitive circuits using steady-state cerebral blood volume and diffusion tensor imaging in patients with mild cognitive impairment following electrical injury.

PURPOSE: We utilized cerebral blood volume (CBV) magnetic resonance imaging and diffusion tensor imaging (DTI) to investigate changes in cognitive networks in patients experiencing cognitive dysfunction following electrical injury. METHODS: Cognitive function was assessed across various domains, including attention, verbal memory, executive function, and language. Depressive symptoms were also evaluated. CBV maps and DTI measures were obtained from 24 patients (age, 41.8 ± 5.8 years; education, 13.3 ± 1.9 years) and 24 healthy controls (age, 42.3 ± 2.7 years; education, 14.3 ± 1.9 years). CBV maps and DTI measures were compared between patients and controls, and correlations between these measures and each cognitive assessment score were examined. RESULTS: Patients exhibited lower attention, verbal memory, and executive function scores than controls (all p < 0.01). Patients also exhibited higher depression scores than controls (p < 0.01), as well as a predominant increase in CBV in the cerebellar vermis relative to that of controls (height p < uncorrected 0.001, extent p < corrected 0.05). Correlation analyses revealed a strong association between executive function scores and CBV in the bilateral posterior cingulate cortex and left mammillary body in patients (height p < uncorrected 0.001, extent p < corrected 0.05). There were no significant differences in DTI measures between patients and controls. CONCLUSION: The CBV maps showed hypermetabolism in the cerebello-limbic system; DTI did not find any microstructural changes. Our results suggest that patients experiencing cognitive dysfunction following electrical injury may possess a cognitive reserve that protects against deteriorating conditions such as dementia.

Preliminary Investigation of Pain-Related Changes in Cerebral Blood Volume in Patients With Phantom Limb Pain.

OBJECTIVE: To investigate changes in the pain network associated with phantom limb pain, magnetic resonance imaging (MRI) was used to measure cerebral blood volume (CBV) in patients who had undergone unilateral arm amputation after electrical injury. DESIGN: Case-controlled exploratory MRI study of CBV via MRI. SETTING: University hospital. PARTICIPANTS: Participants (N=26) comprised patients with phantom limb pain after unilateral arm amputation (n=10) and healthy, age-matched persons (n=16). INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: The intensity of phantom limb pain was measured using the visual analog scale (VAS). Depressive mood was assessed using the Hamilton Depression Rating Scale, and cognitive function was assessed using the Korean version of the Mini-Mental State Examination. Voxel-wise comparisons of relative CBV maps were made between amputees and controls over the entire brain volume. The relationship between individual participant CBV (measured in voxels) and VAS score was also examined. RESULTS: Compared with control participants, amputees exhibited greater degrees of depression; significantly higher CBV in the bilateral medial frontal area (orbitofrontal cortex [OFC] and pregenual anterior cingulate cortex [pACC]); and significantly lower CBV in the right midcingulate cortex, posterior cingulate cortex, and primary somatosensory cortex. CBV increased in the contralateral and ipsilateral hemispheres of the amputated arm, regardless of the amputation side. This CBV increase in the OFC and pACC was strongly correlated with pain intensity in all amputees. CONCLUSIONS: We observed increased CBV in regions associated with emotion in the cerebral pain network of patients who had undergone unilateral arm amputation after electrical injury. This study suggests that CBV changes were related to neuroplasticity associated with phantom limb pain.

Diversity of vir Genes in Plasmodium vivax from Endemic Regions in the Republic of Korea: an Initial Evaluation.

Variant surface antigens (VSAs) encoded by pir families are considered to be the key proteins used by many Plasmodium spp. to escape the host immune system by antigenic variation. This attribute of VSAs is a critical issue in the development of a novel vaccine. In this regard, a population genetic study of vir genes from Plasmodium vivax was performed in the Republic of Korea (ROK). Eighty-five venous blood samples and 4 of the vir genes, namely vir 27, vir 21, vir 12, and vir 4, were selected for study. The number of segregating sites (S), number of haplotypes (H), haplotype diversity (Hd), DNA diversity (π and Θw), and Tajima's D test value were conducted. Phylogenetic trees of each gene were constructed. The vir 21 (S=143, H=22, Hd=0.827) was the most genetically diverse gene, and the vir 4 (S=6, H=4, Hd=0.556) was the opposite one. Tajima's D values for vir 27 (1.08530, P>0.1), vir 12 (2.89007, P<0.01), and vir 21 (0.40782, P>0.1) were positive, and that of vir 4 (-1.32162, P>0.1) was negative. All phylogenetic trees showed 2 clades with no particular branching according to the geographical differences and cluster. This study is the first survey on the vir genes in ROK, providing information on the genetic level. The sample sequences from vir 4 showed a clear difference to the Sal-1 reference gene sequence, whereas they were very similar to those from Indian isolates.

Loop-Mediated Isothermal Amplification Targeting Actin DNA of Trichomonas vaginalis.

Trichomoniasis caused by Trichomonas vaginalis is a common sexually transmitted disease. Its association with several health problems, including preterm birth, pelvic inflammatory disease, cervical cancer, and transmission of human immunodeficiency virus, emphasizes the importance of improved access to early and accurate detection of T. vaginalis. In this study, a rapid and efficient loop-mediated isothermal amplification-based method for the detection of T. vaginalis was developed and validated, using vaginal swab specimens from subjects suspected to have trichomoniasis. The LAMP assay targeting the actin gene was highly sensitive with detection limits of 1 trichomonad and 1 pg of T. vaginalis DNA per reaction, and specifically amplified the target gene only from T. vaginalis. Validation of this assay showed that it had the highest sensitivity and better agreement with PCR (used as the gold standard) compared to microscopy and multiplex PCR. This study showed that the LAMP assay, targeting the actin gene, could be used to diagnose early infections of T. vaginalis. Thus, we have provided an alternative molecular diagnostic tool and a point-of-care test that may help to prevent trichomoniasis transmission and associated complications.

Prevalence of Trichomonas vaginalis in Women Visiting 2 Obstetrics and Gynecology Clinics in Daegu, South Korea.

This study explored epidemiological trends in trichomoniasis in Daegu, South Korea. Wet mount microscopy, PCR, and multiplex PCR were used to test for Trichomonas vaginalis in vaginal swab samples obtained from 621 women visiting 2 clinics in Daegu. Of the 621 women tested, microscopy detected T. vaginalis in 4 (0.6%) patients, PCR detected T. vaginalis in 19 (3.0%) patients, and multiplex PCR detected T. vaginalis in 12 (1.9%) patients. Testing via PCR demonstrated high sensitivity and high negative predictive value for T. vaginalis. Among the 19 women who tested positive for T. vaginalis according to PCR, 94.7% (18/19) reported vaginal signs and symptoms. Notably, more than 50% of T. vaginalis infections occurred in females younger than 30 years old, and 58% were unmarried. Multiplex PCR, which simultaneously detects pathogens from various sexually transmitted infections, revealed that 91.7% (11/12) of patients were infected with 2 or more pathogens. Mycoplasma hominis was the most prevalent co-infection pathogen with T. vaginalis, followed by Ureaplasma urealyticum and Chlamydia trachomatis. Our results indicate that PCR and multiplex PCR are the most sensitive tools for T. vaginalis diagnosis, rather than microscopy which has been routinely used to detect T. vaginalis infections in South Korea. Therefore, clinicians should take note of the high prevalence of T. vaginalis infections among adolescent and young women in order to prevent persistent infection and transmission of this disease.

Effects of a continuous lateral turning device on pressure relief.

[Purpose] The purpose of this study was to examine the pressure-relieving effects of a continuous lateral turning device on common pressure ulcer sites. [Subjects] Twenty-four healthy adults participated. [Methods] The design of our continuous lateral turning device was motivated by the need for an adequate pressure-relieving device for immobile and/or elderly people. The procedure of manual repositioning is embodied in our continuous lateral turning device. The interface pressure and time were measured, and comfort grade was evaluated during sessions of continuous lateral turning at 0°, 15°, 30°, and 45°. We quantified the pressure-relieving effect using peak pressure, mean pressure, and pressure time integration. [Results] Participants demonstrated pressure time integration values below the pressure-time threshold at 15°, 30°, and 45° at all the common pressure ulcer sites. Moreover, the most effective angles for pressure relief at the common pressure ulcer sites were 30° at the occiput, 15° at the left scapula, 45° at the right scapula, 45° at the sacrum, 15° at the right heel, and 30° at the left heel. However, angles greater than 30° induced discomfort. [Conclusion] Continuous lateral turning with our specially designed device effectively relieved the pressure of targeted sites. Moreover, the suggested angles of continuous lateral turning can be used to relieve pressure at targeted sites.

The development of loop-mediated isothermal amplification targeting alpha-tubulin DNA for the rapid detection of Plasmodium vivax.

BACKGROUND: Malaria that is caused by Plasmodium vivax is the most widely distributed human malaria. Its recent resurgence in many parts of the world, including the Republic of Korea (ROK), emphasizes the importance of improved access to the early and accurate detection of P. vivax to reduce disease burden. In this study, a rapid and efficient loop-mediated isothermal amplification (LAMP)-based method was developed and validated using blood samples from malaria-suspected patients. METHOD: A LAMP assay targeting the α-tubulin gene for the detection of P. vivax was developed with six primers that recognize different regions of the target gene. The diagnostic performance of the α-tubulin LAMP assay was compared to three other tests: microscopic examinations, rapid diagnostic tests (RDTs), and nested polymerase chain reactions (PCRs) using 177 whole blood specimens obtained from ROK military personnel from May to December 2011. RESULTS: The α-tubulin LAMP assay was highly sensitive with a detection limit of 100 copies of P. vivax α-tubulin gene per reaction within 50 min. It specifically amplified the target gene only from P. vivax. Validation of the α-tubulin LAMP assay showed that the assay had the highest sensitivity (P < 0.001 versus microscopy; P = 0.0023 versus RDT) when nested PCR was used as the gold standard and better agreement (concordance: 94.9%, kappa value: 0.865) with nested PCR than RDT and microscopy. A Receiver Operation Characteristics analysis showed that the diagnostic accuracy of the α-tubulin LAMP assay for vivax malaria was higher (Area Under Curve = 0.908) than RDT and microscopy. CONCLUSION: This study showed that the P. vivax α-tubulin LAMP assay, which can be used to diagnose early infections of vivax malaria, is an alternative molecular diagnostic tool and a point-of-care test that may help to prevent transmission in endemic areas.