Estimation of intrafamilial DNA contamination in family trio genome sequencing using deviation from Mendelian inheritance.

With the increasing number of sequencing projects involving families, quality control tools optimized for family genome sequencing are needed. However, accurately quantifying contamination in a DNA mixture is particularly difficult when genetically related family members are the sources. We developed TrioMix, a maximum likelihood estimation (MLE) framework based on Mendel's law of inheritance, to quantify DNA mixture between family members in genome sequencing data of parent-offspring trios. TrioMix can accurately deconvolute any intrafamilial DNA contamination, including parent-offspring, sibling-sibling, parent-parent, and even multiple familial sources. In addition, TrioMix can be applied to detect genomic abnormalities that deviate from Mendelian inheritance patterns, such as uniparental disomy (UPD) and chimerism. A genome-wide depth and variant allele frequency plot generated by TrioMix facilitates tracing the origin of Mendelian inheritance deviations. We showed that TrioMix could accurately deconvolute genomes in both simulated and real data sets.

Upregulation of microRNA-597 in myelodysplastic syndromes induces apoptosis through FOSL2 inhibition.

INTRODUCTION: Dysregulation of microRNAs (miRNAs) has been associated with the pathophysiology of myelodysplastic syndrome (MDS). Trisomy 8 is the most frequent chromosomal abnormalities in Korean patients with MDS. We investigated the dysregulation of miR-597-5p, located on chromosome 8, which is reported to induce cell death in numerous cancers. MATERIALS AND METHODS: We compared the expression profiles of miR-597-5p among 65 MDS patients and 11 controls, and analyzed the in vitro effects of miR-597 on leukemic cells using an acute myeloid leukemia cell line transfected with miR-597. RESULTS: We found that miR-597-5p levels were upregulated 4.05-fold in MDS patients compared to those in controls. In vitro study results demonstrated that transfection with a miR-597 mimic induced apoptosis through downregulation of FOS like 2 (FOSL2). CONCLUSION: These findings suggest that upregulation of miR-597 induces apoptosis and that miR-597 has a possible role in the pathophysiology of MDS.

Resurfacing of lower extremities: Versatility of thigh flap as pedicle extension graft with consecutive thoracodorsal artery perforator-based flap.

BACKGROUND: For successful microsurgical reconstruction using free tissue transfer, healthy recipient vessels must be obtained from outside the zone of injury. Securing an appropriate length pedicle length is also essential, and various techniques for lengthening a vascular pedicle have been developed. Herein, we present our experience using the descending branch (DB) of the lateral circumflex femoral vessels (LCFVs) with a thigh flap as an extender graft for consecutive second flap. METHODS: We reconstructed the complex and vessel-depleted defects of nine patients. The mean age was 47.6 years. The defects were located in the lower leg in four patients, in the perineum in two patients and in the forearm in three patients. The two patients who suffered from Fournier's gangrene underwent a pedicled anteromedial thigh (pAMT) flap with the DB of the LCFVs and seven patients, five who suffered high-energy trauma and two who had scar contracture, underwent a free anterolateral thigh (ALT) flap with the distal run-off DB of the LCFVs. In all patients, second consecutive free latissimus dorsi or thoracodorsal artery perforator flaps were prepared and the thoracodorsal vessels of the second flap were anastomosed to the distal DB of the LCFVs. RESULTS: The total length of the thigh flap pedicles measured from both ends of the DB of the LCFVs varied from 15 to 20 cm, which was sufficient for use as a vascular conduit. Of the 18 flaps, 17 survived completely without any complications and 1 pAMT flap showed partial necrosis, which was covered with a perineal perforator-based island flap. The mean follow-up period was 16.7 months. Unfortunately, one patient, who suffered a total amputation below the knee and had replantation surgery, underwent amputation due to venous congestion in the distal leg. However, the previous two flaps survived and were used for coverage of the stump. CONCLUSIONS: Using a thigh flap as a vascular extender graft for second flap may be an alternative option in vessel-depleted reconstructions.

Multilaboratory Evaluation of the MALDI-TOF Mass Spectrometry System, MicroIDSys Elite, for the Identification of Medically Important Filamentous Fungi.

With the increasing number of fungal infections and immunocompromised patients, rapid and accurate fungal identification is required in clinical microbiology laboratories. We evaluated the applicability of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) system, MicroIDSys Elite (ASTA Corp., South Korea) for the identification of medically important filamentous fungi. A total of 505 strains comprising 37 genera and 90 species collected from 11 Korean hospitals were sent to the microbiology laboratory of International St. Mary's Hospital. All isolates were tested using MicroIDSys Elite, and data were analyzed using the MoldDB v.1.22 database (ASTA). Correct identification rates were compared with the multigene sequencing results. MicroIDSys Elite correctly identified 86.5% (437/505) and 88.9% (449/505) of all tested isolates at the species and genus level, respectively. About 98.2% of Aspergillus isolates were identified at the species level, including cryptic and rare species of A. calidoustus, A. tamarii, A. lentulus, A. versicolor and A. aculeatus. MicroIDSys Elite identified 75.0% of basidiomycetes, including Schizophyllum commune, and 84.3% of the dermatophytes. It also distinguished Sprothrix globosa at the species level. The mean scores of total isolates corresponding to correct species identification were significantly higher than those obtained for genus-level identification (253.5 ± 50.7 vs. 168.6 ± 30.3, P < 0.001). MicroIDSys Elite showed high accuracy for the identification of filamentous fungi, including cryptic and rare Aspergillus species. It is suitable for use in clinical laboratories as a rapid and efficient tool for clinical mold identification. Further evaluations are recommended for MicroIDSys Elite as a rapid and efficient tool for the identification of medically important filamentous fungi.

Evaluation of a new matrix-assisted laser desorption/ionization time-of-flight mass spectrometry system for the identification of yeast isolation.

BACKGROUND: Currently, three commercial in vitro diagnostic matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) systems are widely used in clinical laboratories. The ASTA MicroIDSys system (ASTA Inc, South Korea) is a newly developed MALDI-TOF MS system used for the identification of pathogenic microorganisms. In the present study, we assessed the performance of the ASTA MALDI-TOF MS system for the identification of pathogenic yeast from clinical samples. METHODS: We tested 284 clinical yeast isolates from various clinical specimens using ASTA MALDI-TOF MS, and the results were compared with those using molecular sequencing of the ITS or D1-D2 regions of rDNA and biochemical assays. RESULTS: A total of 284 isolates were tested and found to be distributed across 14 species including Candida albicans (n = 100) and other yeast species (n = 184). ASTA MALDI-TOF MS correctly identified 95.1% (270/284) of the yeast species compared to molecular sequencing. Among them, 262 isolates showed acceptable MALDI-TOF MS scores (≥140), and 98.1% (257/262) isolates were identified correctly. In addition, among 22 isolates with a MALDI-TOF MS score <140, 59.1% (13/22) of the isolates showed concordance with molecular typing at the species level. Clustering analysis revealed the effectiveness of the new MALDI-TOF MS system for the identification of yeast species. CONCLUSIONS: ASTA MALDI-TOF MS showed high accuracy in the identification of yeast species; it involves facile sample preparation and extraction procedures. ASTA MALDI-TOF MS is expected to be useful for yeast identification in clinical microbiology laboratories due to its reliability and cost-effectiveness.

The first case of congenital blood chimerism in two of the triplets in Korea.

BACKGROUND: Chimeras are composed of two or more different populations that originated from different zygotes. Blood chimerism arising from twins have been reported in the literature. Herein, we report the first blood group chimerism in triplets. METHODS: ABO blood grouping was carried out by manual tile methods (Merck Millipore, UK) and micro-column agglutination method (Bio-Rad, Cressier sur Morat, Switzerland). Flow cytometric analysis was performed with Anti-A-PE conjugated monoclonal antibodies (BD Biosciences, San Jose, CA, USA) and FACS Canto II (BD Biosciences). Molecular analysis was performed with allele-specific polymerase chain reaction (AS-PCR) and direct sequencing of the exons 6 and 7. RESULTS: Mixed-field agglutination and weak agglutination against anti-A were revealed by ABO blood grouping. Flow cytometric analysis revealed the presence of both A cells and O cells. AS-PCR and sequencing showed two neonates with chimerism, with each neonate`s genotype being A102/O01/O02. CONCLUSION: This is the first recorded case of blood chimera from a triplet in Korea. We recommend full investigation of blood group chimerism in neonates with ABO discrepancy, as blood chimerism is subject to certain caution in the clinical environment.

NaOH-HCl neutralized urine preparation for direct testing of uropathogens by Bruker MS.

BACKGROUND: We evaluated the analytical performance of a NaOH-HCl neutralization protocol for identifying uropathogens directly from urine samples by a Bruker MS system (Bruker Daltonics, German) and sought to establish a protocol for integrating the method with conventional screening. METHODS: Among all urine samples requested for Gram staining, UF-1000i, and urine cultures by physicians, we selected samples that were positive by both Gram staining and UF-1000i testing. Urine was prepared by neutralization using 0.01M NaOH-HCl, and the samples were processed by Bruker MS. For the low detection limit, one strain each of Escherichia coli and Enterococcus faecium was inoculated in sterile deionized water and sterile urine specimens at sequential dilutions. RESULTS: In a total of 1270 urine samples, 125 samples (9.8%) were positive by both Gram staining and UF-1000i. Of 94 samples showing a single morphotype on agar plates, 82 samples had colony counts ≥105  CFU/mL and most uropathogens (95.1%, 78 of 82) had UF-1000i counts ≥106  bacteria/mL. Among them, Bruker MS correctly identified 86.6% (71/82) of all isolates, 89.2% (66/74) of Gram-negative bacteria (GNB), and 62.5% (5/8) of Gram-positive cocci (GPC) with higher average scores for GPC (mean score 2.013) and GNB (mean score 2.110). CONCLUSIONS: Bruker MS with urine preparation by NaOH-HCl neutralization provides a simple, cost-effective, and accurate method for identifying uropathogens directly from urine. Using Bruker MS when single morphotype Gram staining and the UF-1000i count as ≥106  bacteria/mL may improve the efficiency of bacterial identification in routine practice.

An imported case of severe falciparum malaria with prolonged hemolytic anemia clinically mimicking a coinfection with babesiosis.

While imported falciparum malaria has been increasingly reported in recent years in Korea, clinicians have difficulties in making a clinical diagnosis as well as in having accessibility to effective anti-malarial agents. Here we describe an unusual case of imported falciparum malaria with severe hemolytic anemia lasting over 2 weeks, clinically mimicking a coinfection with babesiosis. A 48-year old Korean man was diagnosed with severe falciparum malaria in France after traveling to the Republic of Benin, West Africa. He received a 1-day course of intravenous artesunate and a 7-day course of Malarone (atovaquone/proguanil) with supportive hemodialysis. Coming back to Korea 5 days after discharge, he was readmitted due to recurrent fever, and further treated with Malarone for 3 days. Both the peripheral blood smears and PCR test were positive for Plasmodium falciparum. However, he had prolonged severe hemolytic anemia (Hb 5.6 g/dl). Therefore, 10 days after the hospitalization, Babesia was considered to be potentially coinfected. A 7-day course of Malarone and azithromycin was empirically started. He became afebrile within 3 days of this babesiosis treatment, and hemolytic anemia profiles began to improve at the completion of the treatment. He has remained stable since his discharge. Unexpectedly, the PCR assays failed to detect DNA of Babesia spp. from blood. In addition, during the retrospective review of the case, the artesunate-induced delayed hemolytic anemia was considered as an alternative cause of the unexplained hemolytic anemia.

Influence of NaCl and phosphate on gelation properties of chicken breast myofibrillar protein gels and its application to in vitro digestion model.

To investigate the combination effect of sodium chloride and phosphates on chicken breast myofibrillar proteins, MP gels containing various molarity of NaCl (0.15, 0.30 and 0.45 M) and phosphate (0 and 0.05 M) were prepared, their rheological properties were characterized, and applied to an in vitro digestion model. MP mixture containing 0.45 M NaCl and 0.05 M phosphate had the highest viscosity. The gel strength and cooking yield of MP gels was improved by increasing of molarity of NaCl. As NaCl concentration in MP increased, sulfhydryl levels decreased, while disulfide levels increased. As NaCl and phosphate levels increase, MP gels become denser and porosity decreases, which may reduce protein digestibility. In SDS-PAGE, protein bands from MP gels containing low NaCl levels (≤ 0.30 M) degraded more rapidly during in vitro digestion. These results may support the need for the meat industry to develop low-salt meat products with improved digestibility. KEYWORDS: Chicken, Myofibrillar protein, NaCl, Phosphate, Rheological properties, In vitro digestion.

Whole-genome sequences reveal zygotic composition in chimeric twins.

While most dizygotic twins have a dichorionic placenta, rare cases of dizygotic twins with a monochorionic placenta have been reported. The monochorionic placenta in dizygotic twins allows in utero exchange of embryonic cells, resulting in chimerism in the twins. In practice, this chimerism is incidentally identified in mixed ABO blood types or in the presence of cells with a discordant sex chromosome. Here, we applied whole-genome sequencing to one triplet and one twin family to precisely understand their zygotic compositions, using millions of genomic variants as barcodes of zygotic origins. Peripheral blood showed asymmetrical contributions from two sister zygotes, where one of the zygotes was the major clone in both twins. Single-cell RNA sequencing of peripheral blood tissues further showed differential contributions from the two sister zygotes across blood cell types. In contrast, buccal tissues were pure in genetic composition, suggesting that in utero cellular exchanges were confined to the blood tissues. Our study illustrates the cellular history of twinning during human development, which is critical for managing the health of chimeric individuals in the era of genomic medicine.

The role of failure modes and effects analysis in showing the benefits of automation in the blood bank.

BACKGROUND: Failure modes and effects analysis (FMEA) is a risk management tool used by the manufacturing industry but now being applied in laboratories. STUDY DESIGN AND METHODS: Teams from six South Korean blood banks used this tool to map their manual and automated blood grouping processes and determine the risk priority numbers (RPNs) as a total measure of error risk. RESULTS: The RPNs determined by each of the teams consistently showed that the use of automation dramatically reduced the RPN compared to manual processes. In addition, FMEA showed where the major risks occur in each of the manual processes and where attention should be prioritized to improve the process. Despite no previous experience with FMEA, the teams found the technique relatively easy to use and the subjectivity associated with assigning risk numbers did not affect the validity of the data. CONCLUSION: FMEA should become a routine technique for improving processes in laboratories.

Comparison of whole blood collection and double-unit erythrocytapheresis in preoperative autologous blood donation.

INTRODUCTION: We compared preoperative autologous blood donation (PABD) using serial manual whole blood (WB) and PABD using a single session, double-unit erythrocytapheresis in terms of the hemodynamic recovery and clinical outcomes. MATERIALS AND METHODS: This study included 56 donors in the WB PABD group and 117 donors in the double-unit erythrocytapheresis PABD group. All subjects were men with body weight >70 kg, Hb level >13.3g/dL, Hct >40%, and who were scheduled for oral and maxillofacial surgery. Three cycles of manual WB collection for PABD or a single session, double-unit erythrocytapheresis using the Alyx was performed. RESULTS: There were no significant differences in donor demographic variables including age, height, weight, Hb, Hct, or red cell mass between the 2 groups. The double-unit erythrocytapheresis was completed earlier than the last manual WB PABD (at 15.3 ± 4.7 days and 6.5 ± 3.2 days before surgery, p<0.001). Hct values before surgery were higher in the double-unit erythrocytapheresis PABD group than in the manual WB PABD group (39.7 ± 3.2 vs. 38.6 ± 2.7, p=0.024). ΔHct and %ΔHct before the first PABD and before surgery were lower in the double-unit erythrocytapheresis PABD group than in the manual WB PABD group (-5.6 ± 2.8 vs. -6.8 ± 2.7, p=0.010 and -12.3 ± 5.9 vs. -14.8 ± 5.6, p=0.008, respectively). The incidence of additional allogeneic blood transfusions during or after surgery and the post-operative Hb and Hct values were similar in the 2 groups. The length of hospital stay after surgery was significantly longer in the manual WB PABD group than in the double-unit erythrocytapheresis group (6.1 ± 2.5 vs. 5.4 ± 1.9, p=0.043). Of the 33 donors in the double-unit erythrocytapheresis PABD group, 7 (21.2%) reported discomforts related to the procedure, and 6 graded the discomforts (hypocalcemia, perioral tingling sense, paresthesia, dizziness, stuffiness, pain on the intravenous site, and muscle tension) as mild. CONCLUSION: The single session, double-unit erythrocytapheresis prolonged the time interval between PABD and surgery and led to better hemodynamic recovery than the serial manual WB PABD, and hypocalcemic symptoms were mild.

MicroRNA-765 is upregulated in myelodysplastic syndromes and induces apoptosis via PLP2 inhibition in leukemia cells.

Background: Epigenetic studies, particularly research on microRNA (miRNA), have flourished. The abnormal expression of miRNA contributes to the development of hematologic malignancies. miR-765 has been reported to inhibit cell proliferation by downregulating proteolipid protein 2 (PLP2), which causes apoptosis. We investigated miR-765 dysregulation in myelodysplastic syndromes (MDS). Methods: We compared the expression profiles of miR-765 in 65 patients with MDS and 11 controls. Cell proliferation and apoptosis assays were performed to determine the in vitro effects of miR-765 on leukemia cells transfected with the miR-765 mimic. Reverse transcription quantitative PCR (RT-qPCR) and western blotting were performed to examine the targets of miR-765. Results: We found that miR-765 levels were upregulated 10.2-fold in patients with MDS compared to controls. In refractory cytopenia with multilineage dysplasia, the percentage of patients with elevated miR-765 levels was significantly higher than in other forms of MDS. Experiments with leukemia cells revealed that transfection with a miR-765 mimic inhibited cell proliferation and induced apoptosis. RT-qPCR and western blotting demonstrated that the target of miR-765 was PLP2. Conclusion: These findings imply that upregulation of miR-765 induces apoptosis via downregulation of PLP2 and may have a role in MDS pathogenesis.

Evaluation of Gelation Properties of Salt-Soluble Proteins Extracted from Protaetia brevitarsis Larvae and Tenebrio molitor Larvae and Application to Pork Myofibrillar Protein Gel System.

The purpose of this study was to investigate the functional properties of salt-soluble proteins obtained from Protaetia brevitarsis (PB) and Tenebrio molitor (TM) larvae, the interaction between these proteins and pork myofibrillar protein (MP) in a gel system. The gel properties of salt-soluble protein extracts showed that the PB had a higher viscosity than the TM protein. However, the TM protein had higher gel strength compared with the PB protein. The gelation characteristics of the pork MP gel systems added with lyophilized insect salt-soluble protein powder showed to decrease slightly viscosity compared with MP alone. Adding the TM or PB protein powder did not affect the pork MP's hydrophobicity and sulfhydryl group levels. Furthermore, the protein bands of the MP did not change with the type or amount of insect salt-soluble protein. The cooking yields of the pork MP gels containing PB or TM protein powder were higher than those without insect protein. Regardless of the type of insect salt-soluble protein added, the pork MP's gel strength decreased. Furthermore, as the level of insect powder increased, the surface protein structure became rough and porous. The results demonstrated that proteins extracted from PB and TM larvae interfered with the gelation of pork MP in a gel system.

Strategy for resurfacing complex extremity defect with chimeric, linked flaps: A review with a 10-year experience at major trauma center.

For the reconstruction of the extensive and/or three-dimensional soft-tissue defect in upper and lower extremities, chimeric flaps composed of multiple flaps or tissues with separate vascular supplies can supply economical use of tissue and superior esthetic results. Herein, we investigated the effectiveness of the thoracodorsal axis chimeric flap through the review the largest collection of long-term data. A retrospective review of all patients who received the thoracodorsal axis chimeric flap in complex three-dimensional defects of extremities between January of 2012 and December of 2021. A total of 55 type I/IP classical chimeric flaps, 19 type II/IIP anastomotic chimeric flaps, five type III perforator chimeric flaps, and seven type IV mixed chimeric flaps were analyzed. As the reconstructed area became proximal, flap dimensions increased significantly. And the optimal flap type depended on the location. The TDAp flap can provide large dimensions of skin paddle with latissimus dorsi and serratus anterior muscles with acceptable donor-site morbidities. The TDAp chimeric flaps constructed by microvascular anastomosis of two free flaps can provide large skin dimensions but also tissues with different properties. These characteristics make it possible to resurface the large and extensive defects, reconstruct the complex distal extremity defects, needing tissues with different properties, and cover the three-dimensional defect, obliterating the dead space. The thoracodorsal axis chimeric flap could be a favorable option for extensive, complex, or three-dimensional defects of the upper and lower extremities based on its reliability of the vascular system.

Evaluation of tongue mobility following release operation of ankyloglossia with genioglossus myotomy.

Ankyloglossia is a congenital anomaly characterized by a short lingual frenulum and severe form needs release surgery. Our goal in this study was to confirm the long-term safety and efficacy of Z-plasty with genioglossus myotomy compared with traditional Z-plasty alone and to develop a proper measurement tool to validate the postoperative results of release operations for ankyloglossia. Patients were divided in 2 groups, release with Z-plasty only group (group 1) and Z-plasty combined with genioglossus myotomy group (group 2) In group 2, the release of central longitudinal fiber of genioglossus muscle was added in the conventional Z-plasty operative procedure. To analyze the results of the surgery, we developed an objective assessment tool which is the direct length from the innermost point of the floor of mouth to the tip of the tongue, preoperatively and postoperatively, which is called "functional tongue length." A total of 101 patients with ankyloglossia ranging in age from 36 months to 8 years underwent release operation. Although there was no significant difference in terms of postoperative measurements between groups in Kotlow class II, group 2 patients in Class III and IV showed greater postoperative functional tongue length. Also, there was no significant complication requiring secondary surgery. Our study demonstrated that adding genioglossus myotomy to a simple Z-plasty is a safe and effective method for improving the tongue mobility required to make lingual sounds, especially in moderate to severe form of ankyloglossia, along with suggestion of a new measurement tool, which can objectively assess tongue mobility with possibility for universal utilization in ankyloglossia release operation.

Evaluation of physicochemical and textural properties of chicken breast sausages containing various combinations of salt and sodium tripolyphosphate.

This study was to investigate the effect of salt alone or in combination with phosphate on physicochemical and textural properties, and chemical interactions of low-fat model sausages. pH, color, expressible moisture (EM), cooking loss (CL), proximate analysis, textural profile analysis and low-vacuum scanning electron microscopy were performed. As salt content increased, color tended to decrease, as did EM and CL parameters, indicating that the ability to retain moisture was improved with increased salt levels (p < 0.05). In addition, textural hardness, gumminess and chewiness all increased with increasing salt (p < 0.05). Sausages with 0.3% salt showed the lowest cohesiveness compared to those with salt levels higher than 0.3% (p < 0.05). Addition of sodium tripolyphosphate (STPP) increased pH of sausages. Increasing salt and STPP did not affect lightness (p > 0.05), but did increase redness and yellowness (p < 0.05). The moisture content was higher when the salt and STPP contents were increased (p < 0.05), but no differences in the fat and protein contents (%) were observed (p > 0.05). EM and CL tended to decrease with increasing salt and STPP. In textural properties, the combination of 1.8% salt and 0.3% STPP was the best among other treatment (p < 0.05). Surface microstructure showed a flat and dense structure with increasing salt and STPP. Since the addition of salt and phosphate improved the functionality, textural and physicochemical properties of meat products in this study, meat products will need to be developed in line with consumer's preference.

Eyeball deviation by orbital mucocele after midface sinus injury.

A mucocele is an epithelium-lined, mucus-filled cavity in the paranasal sinuses. Mucocele may develop due to scarring and obstruction of the sinus ostium caused by midface sinus trauma, such as orbital bone fracture or endoscopic sinus surgery. The authors report two cases of orbital mucocele as complications following midface sinus injury (endoscopic sinus surgery in one case, and orbital fracture repair in the other). In both cases, imaging studies showed a large orbital mucocele accompanied by bony erosion and orbital wall remodeling, compressing the ocular muscle. Using an open approach, the lesion was excised and marsupialized. The symptoms resolved, and the postoperative eyeball position was normal. Orbital mucocele may cause serious complications such as ocular symptoms, orbital cellulitis, osteomyelitis, and the formation of an abscess with the potential to invade the brain. Therefore, surgeons should consider the possibility of mucocele as a late complication of surgery and initiate an immediate work-up and surgical treatment if needed.

MicroRNA-661 upregulation in myelodysplastic syndromes induces apoptosis through p53 activation and associates with decreased overall survival.

MicroRNA (miRNA) dysregulation contributes to myelodysplastic syndromes (MDS), and apoptosis is one of the pathogenic features of MDS. We investigated the dysregulation of miRNA expression and its biological significance in MDS. We compared the expression profiles of miRNAs encoded by chromosome 8 in 65 patients with MDS and 11 controls, and analyzed the in vitro effect of the upregulated miRNA expression. We found that compared to the controls, miR-661 was upregulated by 5.28-fold in patients with MDS. Patients with high miR-661 expression showed significantly decreased overall survival. In vitro study results demonstrated that transfection with a miR-661 mimic induced apoptosis through the activation of p53. These findings suggest that high miR-661 expression can be associated with decreased overall survival and recapitulates apoptosis, the characteristic feature of MDS.