A Case of Hemolytic Transfusion Reaction in a Patient with Anti-E, Anti-M, Anti-Jkb, and Anti-Lea / 대한수혈학회지

We reported a case of hemolytic transfusion reaction that was related to multiple RBC antibodies such as anti-E, anti-M, anti-Jkb and anti-Lea after serial RBC transfusions. A forty-nine year old female visited the emergency room (ER) with hematochezia. She had previously received 16 units of packed RBCs from 2003 to Jan 2007 for her intermittent esophageal varix bleeding. No specific antibodies were identified before this visiting. At the ER, under the request for packed RBCs, we identified anti-E antibody within her serum. Her blood type was AB, RhD+ with the phenotype of CcDe. She received 5 units of E antigen negative RBCs. However, she showed hemolytic transfusion reactions such as mild fever with a decrease of hemoglobin from 11.4 g/dL to 6.8 g/dL after the transfusion. From the 8th to the 10th hospital day, another 3 units of E-antigen negative with the least incompatible RBCs were transfused to the patient, but the level of hemoglobin was not definitely increased. At the 14th hospital day, she received a final 2 units of leuko-reduced RBCs without E, M and Jkb antigens. Her hemoglobin was increased right after the final transfusion. We found that the patient's serum reacted with multiple RBC antibodies such as anti-E, anti-M, anti-Jkb and anti-Lea antibodies. She finally recovered from acute varix bleeding and was discharged on the 26th hospital day with the level of hemoglobin being 8.3 g/dL.

Properties of stretch-activated K+ channels in an G292 osteoblast-like cell / 대한치과교정학회지

K+ -selective ion channels were studied in excised inside-out membrane patches from human osteoblast-like cells(G292). There classes of K+ channels were present and could be distinguished on the basis of conductance. Conductances were 270+/-27 pS, 113+/-12 pS, 48+/-8 pS according to their approximate conductances in symmetrical 140 mM KCI saline at holding potential of -80 mV. It was found that the small conductance (48 pS) K+ channel activation was dependent on membrane voltage. In current-voltage relationship, small conductance K+ channel showed outward rectification, and it was activated by the positive potential inside the membrane. In recordings, single channel currents were activayed by a negative pressure outside the membrane. The membrane pressure increased P(open) of the K+ channel in a pressure-dependent manner. In the excised-patch clamp recordings, G292 osteoblast-like cells have been shown to contain three types of K+ channels. Only the small conductance (48 pS) K+ channel is sensitive to the membrane stretch. These findings suggest that a hyperpolarzing current, mediated in part by this channel, may be associated with early events during the mechanical loading of the osteoblast. In G292 osteoblast-like cells, K+ channel is sensitive to membrane tension, and may represent a unique adaptation of the bone cell membrane to mechanical stress.

Development of Test System for Detection of Antibody to Human Immunodeficiency Virus Type 1 Subtype O

In Korea, all domestic made test systems for detecting antibodies in HIV-1 contain the antigens from human immunodeficiency type 1 (HIV-1) subtype B. However, because HIV-1 subtype O is significantly different in amino acid sequences from all other subtypes of HIV-1, there has been a need for developing a test for detecting antibodies in subtype O. For this purpose, the entire nucleotide sequence corresponding to the extracellular domain of the transmembrane glycoprotein of HIV-1 subtype O was synthesized with consideration of Escherichia coli cordon usage. Various regions of the extracellular domain were cloned into E. coli expression vectors and tested for levels of protein production. The nucleotide sequence, named ECTM, that can encode a 129 amino acid-long peptide, was found to be expressed at a high level in E. coli. The protein of approximately 17 kDa specifically reacted with sera from individuals infected with HIV-1 subtype O. The ECTM protein was purified to near homogeneity by the CM-T gel chromatography, using concentrated, denatured inclusion bodies. In Western blot analysis, the purified viral antigen reacted with sera from individuals infected with subtype O more efficiently than subtype B. The enzyme linked immunoabsorbent assay (ELISA) system was developed using the subtype O viral protein and compared with the commercially available kit lacking the antigens from subtype O. The ELISA kit containing the subtype O antigen ECTM alone efficiently reacted with sera from individuals infected with subtype O. The subtype O antigen-containing kit produced a positive absorbence even when sera were diluted 512-fold, suggesting a high sensitivity. The commercially available kit also reacted with subtype O sera, but produced a negative result at a dilution of 8-fold. Our results suggest that the currently available kit may not be able to efficiently detect subtype O sera and that the viral protein developed in this study may be added to the current system to maximize the detection of sera from individuals infected with subtype O.