• Molecules and Cells
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• v.23 no.1
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• pp.17-22
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• 2007

We have expressed human erythropoietin (EPO) in transgenic mice using a recombinant EPO cDNA combined with a partial TPO construct. The gene was microinjected using standard techniques and five mice were detected as transgenic by PCR and further used as founders. The life span of the transgenic founders was much shorter than that of their normal littermates. Most of the tissues of the transgenic founders contained human EPO transcripts as judged by RT-PCR. Especially high expression levels were seen in the liver and lung. EPO protein levels in serum were examined by ELISA and ranged from 266-414 mIU/ml. The number of red blood cell, white blood cell and hemoglobin in the hEPO transgenic mice was higher than in normal mice. These results indicate that overexpression of hEPO is deleterious and can provoke lung failure and erythrocytosis.

• Archives of Plastic Surgery
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• v.47 no.5
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• pp.404-410
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• 2020

Background Some patients who need surgery refuse a blood transfusion because of their religious beliefs or concerns about blood-borne infections. In recent years, bloodless surgery has been performed successfully in many procedures, and is therefore of increasing interest in orthognathic surgery. Methods Ten Jehovah's Witnesses who visited our bloodless surgery center for orthognathic surgery participated in this study. To maintain hemoglobin (Hb) levels above 10 g/dL before surgery, recombinant erythropoietin (rEPO) was subcutaneously administered and iron supplements were intravenously administered. During surgery, acute normovolemic hemodilution (ANH) and induced hypotensive anesthesia were used. To elevate the Hb levels to >10 g/dL after surgery, a similar method to the preoperative approach was used. Results The 10 patients comprised three men and seven women. Their average Hb level at the first visit was 11.1 g/dL. With treatment according to our protocol, the average preoperative Hb level rose to 12.01 g/dL, and the average Hb level on postoperative day 1 was 10.01 g/dL. No patients needed a blood transfusion, and all patients were discharged without any complications. Conclusions This study presents a way to manage patients who refuse blood transfusions while undergoing orthognathic surgery. rEPO and iron supplementation were used to maintain Hb levels above 10 g/dL. During surgery, blood loss was minimized by a meticulous procedure and induced hypotensive anesthesia, and intravascular volume was maintained by ANH. Our practical approach to orthognathic surgery for Jehovah's Witnesses can be applied to the management of all patients who refuse blood transfusions.

• Clinical and Experimental Pediatrics
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• v.52 no.10
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• pp.1061-1068
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• 2009

The treatment of pediatric patients with chronic renal disease comprises management of nutritional imbalance, fluid, electrolyte, and acid-base disturbances, mineral bone disease, anemia, hypertension, and growth retardation. The treatment also includes administration of appropriate renal replacement therapy, if required. Adequate dietary intake of carbohydrates, fats, and proteins and caloric intake must be encouraged in such patients to ensure proper growth and development. In addition, fluid, electrolyte, and acid-base status must be regularly monitored and should be well maintained. Serum calcium, phosphorus, and parathyroid hormone levels must be maintained at their target range, which are determined on the basis of the glomerular filtration rate, to avoid the development of mineral bone disease. This can be achieved by using phosphorus binders and vitamin D analogues. An erythropoiesis-stimulating agent must be administered along with iron supplementation to maintain the hemoglobin level of the patients between 11-12 g/dL. Hypertension must be controlled with adequate water and sodium balance and appropriate antihypertensive agents. Administration of recombinant human growth hormone is recommended to improve the final adult heights.

• Proceedings of the Korean Society of Embryo Transfer Conference
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• 2002.11a
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• pp.97-97
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• 2002

Human eryhropoietin (EPO) is acidic glycoprotein hormone that plays key role in hematopoiesis by facilitating differentiation of erythrocyte and formation of hemoglobin (Hb) and is used for the treatment of anemia. Human EPO is consist of 166 amino acids which is modified by three N-glycosylations (24, 38, 83) and single O-glycosylation (126). N-glycosylation is reported to be related to the cellular secretion and activity of EPO. In this study, we examined effects of mutagenesis in glycosylation site of recombinat hEPO for the cellular secretion during production from cultured CHO cell. We produced rhEpo which was cloned by PCR from human liver cDNA (TaKaRa) in cultured CHO cell. Using supernatant of the culture, ELISA assay and western analysis were performed. To estimate biological activity, 20IU of rhuEpo was subcutaneously injected into four ICR mice. After 8 days, HCT level was increased average 13 per cent, RBC was increased ca. 2${\times}$10$\^$6//${\mu}\ell$. In disease model Rat (anemia c-kit, WSRC-WS/WS), HCT was increased ca. 12%, RBC was increased ca. 1.6${\times}$10$\^$6//${\mu}\ell$. These results suggests that rhEpo we produced has biological activity. To remove glycosylation site by substituting 24, 38, 83, and 126th asparagine (or serine) with glutamic acid, overlapping -extension site-directed mutagenesis was performed. To add novel glycosylation sites, 69, 105th leucine was mutated to asparagine. Mutant EPO construct was transfected into CHO cell. Supernatant of the cell culture was analyzed using ELISA assay with monoclonal anti-EPO antibody (Medac, Germany). Since, several reports for mutagenesis of glycosylation sites showed case-by-case results, we examined both transient expression and stable expression. Addition of novel glycosylation sites resulted no secretion while deletion mutants had little effect except some double deletion mutants (24/83 and 38/83) and triple mutant. We suggest that not single but combination of glycosyl group affect secretion of EPO.