Effect of Xenogeneic Substances on the Glycan Profiles and Electrophysiological Properties of Human Induced Pluripotent Stem Cell-Derived Cardiomyocytes

Background and Objectives@#Human induced pluripotent stem cell (hiPSC)-derived cardiomyocyte (CM) hold greatpromise as a cellular source of CM for cardiac function restoration in ischemic heart disease. However, the use of animal-derived xenogeneic substances during the biomanufacturing of hiPSC-CM can induce inadvertent immune responses or chronic inflammation, followed by tumorigenicity. In this study, we aimed to reveal the effects of xenogeneic substances on the functional properties and potential immunogenicity of hiPSC-CM during differentiation, demonstrating the quality and safety of hiPSC-based cell therapy. @*Methods@#and Results: We successfully generated hiPSC-CM in the presence and absence of xenogeneic substances(xeno-containing (XC) and xeno-free (XF) conditions, respectively), and compared their characteristics, including the contractile functions and glycan profiles. Compared to XC-hiPSC-CM, XF-hiPSC-CM showed early onset of myocyte contractile beating and maturation, with a high expression of cardiac lineage-specific genes (ACTC1, TNNT2, and RYR2) by using MEA and RT-qPCR. We quantified N-glycolylneuraminic acid (Neu5Gc), a xenogeneic sialic acid, in hiPSC-CM using an indirect enzyme-linked immunosorbent assay and liquid chromatography-multiple reaction monitoring-mass spectrometry. Neu5Gc was incorporated into the glycans of hiPSC-CM during xeno-containing differentiation, whereas it was barely detected in XF-hiPSC-CM. @*Conclusions@#To the best of our knowledge, this is the first study to show that the electrophysiological function andglycan profiles of hiPSC-CM can be affected by the presence of xenogeneic substances during their differentiation and maturation. To ensure quality control and safety in hiPSC-based cell therapy, xenogeneic substances should be excluded from the biomanufacturing process.

Reliability and Validity of a Short Form of the Korean Dementia Screening Questionnaire-Cognition

Nutritional Management of a Patient with a High-Output Stoma after Extensive Small Bowel Resection to Treat Crohn's Disease

For patients with short bowel syndrome who undergo ileostomy, nutritional management is essential to prevent complications associated with a high-output stoma (HOS). We report a practical example of ostomic, medical nutrition therapy provided by an intensive nutritional support team (NST). A 42-year-old male with a history of Crohn's disease visited Seoul National University Hospital for treatment of mechanical ileus. He underwent loop ileostomy after extensive small bowel resection. As his remaining small bowel was only 160 cm in length, the stomal output was about 3,000 mL/day and his body weight fell from 52.4 to 40.3 kg. Given his clinical condition, continuous tube feeding for 24 h was used to promote adaptation of the remnant bowel. Thereafter, an oral diet was initiated and multiple, nutritional educational sessions were offered by dietitians. Constant infusion therapy was prescribed and included in the discharge plan. Two months after discharge, his body weight had increased to 46.6 kg and his hydration status was appropriately maintained. This case suggests that the critical features of medical nutritional therapy for ostomy management are frequent assessments of fluid balance, weight history, and laboratory data and after nutritional interventions.

A Comparative Evaluation of the KDSQ-C, AD8, and SMCQ as a Cognitive Screening Test to Be Used in National Medical Check-ups in Korea

BACKGROUND: Korea has a periodic general health check-up program that uses the Korean Dementia Screening Questionnaire-Cognition (KDSQ-C) as a cognitive dysfunction screening tool. The Alzheimer Disease 8 (AD8) and Subjective Memory Complaints Questionnaire (SMCQ) are also used in clinical practice. We compared the diagnostic ability of these screening questionnaires for cognitive impairment when completed by participants and their caregivers. Hence, we aimed to evaluate whether the SMCQ or AD8 is superior to the KDSQ-C and can be used as its replacement. METHODS: A total of 420 participants over 65 years and their informants were recruited from 11 hospitals for this study. The patients were grouped into normal cognition, mild cognitive impairment, and dementia subgroups. The KDSQ-C, AD8, and SMCQ were completed separately by participants and their informants. RESULTS: A receiver operating characteristic analysis of questionnaire scores completed by participants showed that the areas under the curve (AUCs) for the KDSQ-C, AD8, and SMCQ for diagnosing dementia were 0.75, 0.8, and 0.73, respectively. Regarding informant-completed questionnaires, the AD8 (AUC of 0.93), KDSQ-C (AUC of 0.92), and SMCQ (AUC of 0.92) showed good discriminability for dementia, with no differences in discriminability between the questionnaires. CONCLUSION: When an informant-report is possible, we recommend that the KDSQ-C continues to be used in national medical check-ups as its discriminability for dementia is not different from that of the AD8 or SMCQ. Moreover, consistent data collection using the same questionnaire is important. When an informant is not available, either the KDSQ-C or AD8 may be used. However, in the cases of patient-reports, discriminability is lower than that for informant-completed questionnaires.

Cardiac Regeneration with Human Pluripotent Stem Cell-Derived Cardiomyocytes

Embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs), which are collectively called pluripotent stem cells (PSCs), have emerged as a promising source for regenerative medicine. Particularly, human pluripotent stem cell-derived cardiomyocytes (hPSC-CMs) have shown robust potential for regenerating injured heart. Over the past two decades, protocols to differentiate hPSCs into CMs at high efficiency have been developed, opening the door for clinical application. Studies further demonstrated therapeutic effects of hPSC-CMs in small and large animal models and the underlying mechanisms of cardiac repair. However, gaps remain in explanations of the therapeutic effects of engrafted hPSC-CMs. In addition, bioengineering technologies improved survival and therapeutic effects of hPSC-CMs in vivo. While most of the original concerns associated with the use of hPSCs have been addressed, several issues remain to be resolved such as immaturity of transplanted cells, lack of electrical integration leading to arrhythmogenic risk, and tumorigenicity. Cell therapy with hPSC-CMs has shown great potential for biological therapy of injured heart; however, more studies are needed to ensure the therapeutic effects, underlying mechanisms, and safety, before this technology can be applied clinically.

Cardiac Regeneration with Human Pluripotent Stem Cell-Derived Cardiomyocytes

Embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs), which are collectively called pluripotent stem cells (PSCs), have emerged as a promising source for regenerative medicine. Particularly, human pluripotent stem cell-derived cardiomyocytes (hPSC-CMs) have shown robust potential for regenerating injured heart. Over the past two decades, protocols to differentiate hPSCs into CMs at high efficiency have been developed, opening the door for clinical application. Studies further demonstrated therapeutic effects of hPSC-CMs in small and large animal models and the underlying mechanisms of cardiac repair. However, gaps remain in explanations of the therapeutic effects of engrafted hPSC-CMs. In addition, bioengineering technologies improved survival and therapeutic effects of hPSC-CMs in vivo. While most of the original concerns associated with the use of hPSCs have been addressed, several issues remain to be resolved such as immaturity of transplanted cells, lack of electrical integration leading to arrhythmogenic risk, and tumorigenicity. Cell therapy with hPSC-CMs has shown great potential for biological therapy of injured heart; however, more studies are needed to ensure the therapeutic effects, underlying mechanisms, and safety, before this technology can be applied clinically.

Intensive Nutrition Management in a Patient with Short Bowel Syndrome Who Underwent Bariatric Surgery

Many individuals with short bowel syndrome (SBS) require long-term parenteral nutrition (PN) to maintain adequate nutritional status. Herein, we report a successful intestinal adaptation of a patient with SBS through 13 times intensive nutritional support team (NST) managements. A thirty-five-year-old woman who could not eat due to intestinal discontinuity visited Seoul National University Hospital for reconstruction of the bowel. She received laparoscopic Roux-en-Y gastric bypass (RYGB) due to morbid obesity in Jan 2013 at a certain hospital and successfully reduced her weight from 110 kg to 68 kg. However, after a delivery of the second baby by cesarean section in Jul 2016, most of small bowel was herniated through Peterson’s defect, and emergent massive small bowel resection was performed. Thereafter, she visited our hospital for the purpose of intestinal reconstruction. In Sep 2016, she received side–to-side gastrogastrostomy and revision of double barrel enterostomy. The remaining small bowel included whole duodenum, 30 cm of proximal jejunum, and 10 cm of terminal ileum. Pylorus and ileocecal valves were intact. The patient given only PN after surgery was provided rice-based soft fluid diet after 10 day of operation. Through intensive nutritional management care, she could start solid meals, and finally stop the PN and eat only orally at 45 days postoperatively. Three nutritional interventions were conducted over 2 months after the patient was discharged. She did not require PN during this period, and maintained her weight within the normal weight range. Similar interventions could be used for other patients with malabsorption problems similar to SBS.

In-depth Medical Nutrition Therapy for a Woman with Diabetes: From Pregnancy to Delivery

Diabetes in pregnancy is associated with higher rates of miscarriage, pre-eclampsia, preterm labor, and fetal malformation. To prevent these obstetric and perinatal complications, women with diabetes have to control levels of blood sugar, both prior to and during pregnancy. Thus, individualized medical nutrition therapy for each stage of pregnancy is essential. We provided in-depth medical nutrition therapy to a 38-year-old pregnant woman with diabetes at all stages of pregnancy up to delivery. She underwent radiation therapy after surgery for breast cancer and was diagnosed with diabetes. At the time of diagnosis, her glycated hemoglobin level was 8.3% and she was planning her pregnancy. She started taking an oral hypoglycemic agent and received education regarding the management of diabetes and preconception care. She became pregnant while maintaining a glycated hemoglobin level of less than 6%. We provided education program for diabetes management during the pregnancy, together with insulin therapy. She experienced weight loss and ketones were detected; furthermore, she was taking in less than the recommended amount of foods for the regulation of blood sugar levels. By giving emotional support, we continued the counseling and achieved not only glycemic control but also instilled an appreciation of the importance of appropriate weight gain and coping with difficulties. Through careful diabetes management, the woman had a successful outcome for her pregnancy, other than entering preterm labor at 34 weeks. This study implicated that the important things in medical nutrition therapy for pregnant women with diabetes are frequent follow-up care and emotional approach through the pregnancy process.

Quinolone-resistant Shigella flexneri Isolated in a Patient Who Travelled to India

We report a recent case in which ciprofloxacin-resistant Shigella flexneri was isolated from a 23-yr-old female patient with a history of travel to India. Prior to her admission to our internal medicine department, she experienced symptoms of high fever and generalized weakness from continuous watery diarrhea that developed midway during the trip. S. flexneri was isolated from the stool culture. Despite initial treatment with ciprofloxacin, the stool cultures continued to show S. flexneri growth. In the susceptibility test for antibiotics of the quinolone family, the isolate showed resistance to ciprofloxacin (minimum inhibitory concentration [MIC], 8 microg/mL), norfloxacin (MIC, 32 microg/mL), ofloxacin (MIC, 8 microg/mL), nalidixic acid (MIC, 256 microg/mL), and intermediate resistance to levofloxacin (MIC, 4 microg/mL). In molecular studies for quinolone resistance related genes, plasmid borne-quinolone resistance genes such as qnrA, qnrB, qnrS, aac(6')-Ib-cr, qepA, and oqxAB were not detected. Two mutations were observed in gyrA (248C-->T, 259G-->A) and 1 mutation in parC (239G-->T). The molecular characteristics of the isolated S. flexneri showed that the isolate was more similar to the strains isolated from the dysentery outbreak in India than those isolated from Korea.

Rapid Detection of Extended Spectrum beta-Lactamase (ESBL) for Enterobacteriaceae by use of a Multiplex PCR-based Method

A multiplex PCR method has been developed to classify extended spectrum beta-lactamase (ESBL) and plasmid-mediated AmpC beta-lactamase (PABL). This method consists of the use of two four-multiplex PCRs for the detection of TEM, OXA, SHV, CTX-M, CMY, and DHA type beta-lactamases. We have compared findings from the use of conventional detection methods with that of this newly developed typing method. In testing for 73 ESBL-producing and PABL-producing isolates, 100% of the isolates were correctly identified as previously characterized types and, 44 types of beta-lactamases were additionally identified from 33 isolates. This assay not only reduces the time for classification but also increases the accuracy for detection.

Rapid Detection of Extended Spectrum beta-Lactamase (ESBL) for Enterobacteriaceae by use of a Multiplex PCR-based Method

A multiplex PCR method has been developed to classify extended spectrum beta-lactamase (ESBL) and plasmid-mediated AmpC beta-lactamase (PABL). This method consists of the use of two four-multiplex PCRs for the detection of TEM, OXA, SHV, CTX-M, CMY, and DHA type beta-lactamases. We have compared findings from the use of conventional detection methods with that of this newly developed typing method. In testing for 73 ESBL-producing and PABL-producing isolates, 100% of the isolates were correctly identified as previously characterized types and, 44 types of beta-lactamases were additionally identified from 33 isolates. This assay not only reduces the time for classification but also increases the accuracy for detection.

Detection of the Causative Agents of Traveler's Diarrhea Using a Real-Time PCR Screening Method / 대한임상미생물학회지

BACKGROUND: The incidence of infectious diarrheal disease in Korea has decreased over the past decade, but traveler's diarrhea (TD) is increasing in frequency. We therefore investigated the distribution of the causative agents of TD. METHODS: A total of 132 rectal swab specimens were acquired from TD patients who entered the country via Gimhae International Airport. The specimens were screened for 12 bacterial pathogens by real-time PCR, and target pathogens were isolated from the PCR positive specimens using conventional microbiological isolation methods. RESULTS: A total of 93 specimens (70.5%) showed positive PCR screening results, and of these specimens, nine species and 50 isolates (37.9%), including Vibrio parahaemolyticus (18 isolates) and ETEC (17 isolates), were isolated. No specimens were PCR positive for Listeria monocytogenes or Campylobacter jejuni, and no pathogenic Bacillus cereus were isolated. CONCLUSION: Even though viruses and EAEC were not included as target pathogens, the high isolation rate of these pathogens in this study provides indirect evidence that most cases of pathogen-negative TD are caused by undetected bacterial agents. Furthermore, our study results confirm the effectiveness of real-time PCR-based screening methods. This study is the first report in Korea to demonstrate that ETEC and V. parahaemolyticus are the major causative pathogens of TD, and this knowledge can be used to help treat and prevent TD.

Detection of Point Mutations in the rpoB gene Related to Drug Susceptibility in Mycobacterium Tuberculosis using an Oligonucleotide Chip / 결핵

BACKGROUND: The appearance of multiple-drug-resistant Mycobacterium tuberculosis strains has been seriously compromising successful control of tuberculosis. Rifampin-resistance, caused by mutations in the rpoB gene, can be indicative of multiple-drug-resistance, and its detection is of great importance. The present study aimed to develop an oligonucleotide chip for accurate and convenient screening of drug-resistance. METHODS: In order to detect point mutations in the rpoB gene, an oligonucleotide chip was prepared by immobilizing specific probe DNA to a microscopic slide glass by a chemical reaction. The probe DNA that was selected from the 81 bp core region of the rpoB gene was designed to have mutation sites at the center. A total of 17 mutant probes related to rifampin-resistance including 8 rifabutin-sensitive mutant probes were used in this study. For accurate determination, wild type probes were prepared for each mutation position with an equal length, which enabled a direct comparison of the hybridization intensities between the mutant and wild type. RESULTS: Mycobacterial genomic DNA from clinical samples was tested with the oligonucleotide chip and the results were compared with those of the drug-susceptibility test in addition to sequencing and INNO-LiPA Rif. TB kit test in some cases. Out of 15 samples, the oligonucleotide chip results of 13 samples showed good agreement with the rifabutin-sensitivity results. The two samples with conflicting result also showed a discrepancy between the other tests, suggesting such possibilities as existence of mixed strains and difference in drug-sensitivity. Further verification of these samples in addition to more case studies are required before the final evaluation of the oligonucleotide chip can be made. CONCLUSION: An oligonucleotide chip was developed for the detection of rpoB gene mutations related to drug-susceptibility. The results to date show the potential for using the oligonucleotide chip for accurate and convenient screening of drug-resistance to provide useful information in antituberculosis drug therapy.