Contamination of Bacillus cereus in an apheresis-derived platelet concentrate.
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Adult↗
Biomedical subjects
S Sekiguchi
Publications and source records attributed to S Sekiguchi.
A novel gene (drad-1) expressed in hematopoiesis-supporting stromal cell lines, ST2, PA6 and A54 preadipocytes: use of mRNA differential display.
We established a differentiation-inducible preadipocyte cell line, designated A54 preadipocytes, from C3H10T1/2 (10T1/2) mouse embryo fibroblasts. A54 preadipocytes had marked hematopoiesis-supporting ability in vitro but this ability was lost after terminal differentiation to adipocytes. In this study, to identify molecules that contribute to the hematopoiesis-supporting ability of A54 preadipocytes, we screened genes that were differentially expressed in A54 preadipocytes and isolated seven novel genes by reverse transcriptase polymerase chain reaction mRNA differential display. An RNase protection assay confirmed that one of these genes was expressed at high levels in parent 10T1/2 cells and A54 preadipocytes but to a much lesser extent in fully differentiated A54 adipocytes. This gene was defined as a gene that was downregulated during adipocyte differentiation-1 (drad-1). The size of drad-1 mRNA was 8.2 kb, and the gene was expressed in other mouse preadipocytes, namely, ST2 and PA6 cells, that have hematopoiesis-supporting ability. Moreover, drad-1 was also found to be expressed in bone marrow in vivo. The function of the protein encoded by drad-1 is unknown, but the expression of the gene may be useful as a molecular marker of adipocyte differentiation.
Adipocytes↗
Liver transplantation for severe hypoxemia caused by patent ductus venosus.
The authors describe the case of a 9-year-old girl who underwent liver transplantation because she suffered from severe hypoxemia caused by patent ductus venosus (PDV). Generally, severe hypoxemia (PaO2 < 50 mm Hg in room air or < 300 mm Hg in pure oxygen) is not an indication for liver transplantation because the hypoxemia may not be improved, and may lead to a fatal outcome. PDV, which is associated with mild liver dysfunction, is not an indication for liver transplantation by itself. But in our patient, most of the mesenteric venous flow directly entered the systemic circulation through the PDV just like the portosystemic shunt, and this caused the pulmonary arteriovenous shunt and hypoxemia. Thus, the authors operated on the patient in an attempt to restore her pulmonary function. Nitric oxide (10 to 20 ppm) was added to the inhaled gas to dilate the functional pulmonary capillaries and to deliver sufficient oxygen after the transplantation. Although the patient suffered various complications after the operation, the final results were excellent.
Angiography, Digital Subtraction↗
A rapid nylon-fiber syringe system to deplete CD14+ cells for positive selection of human blood CD34+ cells. Use of immunomagnetic microspheres.
To achieve a rapid and an efficient purification of CD34+ cells, we devised a nylon-fiber syringe (NF-S) and we manipulated it to deplete adherent cells from normal human blood mononuclear cells (MN cells). The cells processed by NF-S were further purified as the CD34+ fraction, using CD34 monoclonal antibody, immunomagnetic microspheres and chymopapain treatment to detach the microspheres. When steady-state human peripheral blood MN cells were processed by NF-S at 24 degrees C for 5 min, the frequency of monocytes (CD14+ cells) significantly decreased from 22.0 +/- 5.2% to 2.5 +/- 0.4%, with a 73% recovery of CD34+ cells. The subsequent immunomagnetic positive selection achieved preparations of 91 +/- 8% pure CD34+ cells with a 86 +/- 23% yield. The overall yield of CD34+ cells was 44 +/- 11%, and the time required for all procedures was 5 h. There was a tight and an inverse correlation (P < 0.0001) between the frequency of CD14+ cells in the initial cell population and the purity of CD34+ cells in the final preparation. A recommended frequency of CD14+ cells for achieving preparations of over 90% pure CD34+ cells was less than 4.4%. When combining NF-S and immunomagnetic microspheres, efficient bench-top separation of CD34+ cells in steady-state peripheral blood can be done in any laboratory, and fluorescence-activated cell-sorting is not required.
Antigens, CD34↗
Epidemiology of GBV-C in Japan.
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Flaviviridae↗
Generation of interleukin 8 in stored apheresis platelet concentrates and the preventive effect of prestorage ultraviolet B radiation.
BACKGROUND: Several recent studies have reported both the generation of cytokines, including interleukin (IL)-1 beta, IL-6, tumor necrosis factor alpha (TNF-alpha), and IL-8, in the supernatants of stored platelet concentrates (PCs) and the implications of this generation in febrile nonhemolytic transfusion reactions. Prestorage filtration is regarded as highly effective in the prevention of cytokine generation. STUDY DESIGN AND METHODS: Studies evaluated 1) the levels of these cytokines in apheresis PCs during storage, 2) the effects of white cell inactivation by ultraviolet B or gamma-radiation on the generation of cytokines, and 3) the effects of poststorage filtration on cytokine levels. The apheresis PCs were treated by either ultraviolet B radiation (20,000 J/m2), gamma-radiation (30 Gy), or filtration. Samples were collected sequentially on various days after storage. Cytokines were determined by enzyme-linked immunosorbent assay. RESULTS: The average white cell count in 15 PCs tested was 2.58 +/- 0.7 x 10(6) per mL (range, 0.7-10 x 10(6)/mL). A detectable level of IL-8 was found at 3 days of storage, and the levels of this cytokine increased progressively with increasing storage time, ranging from 1.6 to 35,280 pg per mL on Day 5 and from 2.7 to 83,601 pg per mL on Day 8. Reverse transcriptase-polymerase chain reaction analysis showed that the level of IL-8 paralleled the expression of IL-8 transcripts. The levels of IL-1 beta, IL-6, TNF-alpha, and monocyte chemotactic protein-1 were very low, even on Day 8. Ultraviolet B-radiated PCs failed to generate IL-8, even at 8 days of storage, whereas levels of IL-8 in gamma-radiated PCs were similar to those in nonirradiated PCs. Poststorage filtration of PCs with a negatively charged polyester filter, but not with a positively charged one, markedly reduced the levels of IL-8. CONCLUSION: Of the cytokines tested, IL-8 had the most evident generation in apheresis PCs during storage. Prestorage inactivation of white cells by ultraviolet B radiation, but not by gamma-radiation, was effective in preventing the generation of cytokines during the storage of PCs.
Anaphylatoxins↗
Anti-hepatitis C virus seroconversion in blood donors in Japan.
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Blood Donors↗
Changes in donor apheresis in Japan.
Donor apheresis has played an important role in the Japanese blood program. Donor plasmapheresis was introduced to increase source plasma in 1986 and accounted for 20.8% of all donations in 1995. The total volume of source plasma increased from 104 x 10(3) L in 1989 to 636 x 10(3) L in 1994, and the rate of self-sufficience of factor VIII reached 100% in 1994 (excluding recombinant products). This rate had been below 10% in 1991. The supply of platelet products has increased rapidly in Japan and reached 7.19 million units in 1995. The number of platelet products obtained with the apheresis procedure accounted for 99.99% in all supplied products in the Hokkaido Red Cross Blood Center. Thus, it can be seen that platelet apheresis has played an important role in securing a sufficiency of the products. Another advantage of platelet apheresis is the reduction of residual leukocytes in the products, which helps to avoid donor antigen exposure and prevent febrile nonhemolytic reaction. The technique of apheresis has been applied in cancer therapy. Peripheral blood stem cell (PBSC) transplantation has been performed not only in autologous but also allogeneic settings instead of bone marrow transplantation. In the authors' experience, sufficient numbers of progenitor cells could be collected in 85.7% of patients within 2 leukaphereses; thus, apheresis will become more important in this field.
Adult↗
Factors affecting M13 bacteriophage inactivation by methylene blue photosensitization.
We have investigated the factors that affect the virucidal activity of methylene blue (MB) photosensitization. The M13 bacteriophage was more rapidly inactivated at higher temperatures (6 degrees C < 24 degrees C < 38 degrees C). Rate constants for inactivation were 0.072, 0.139 and 0.260 (log10 inactivation)/ (J/cm2) at 6 degrees C, 24 degrees C and 38 degrees C, respectively. On the other hand, dye penetration into virus particles, which was monitored by the fluorescence of YOYO-1, was unchanged with incubation temperature. These data suggest that temperature dependency of M13 inactivation was due to factors other than dye permeability. The pH of the virus suspension also affected the rate of M13 inactivation by MB. The M13 bacteriophage was inactivated faster in basic suspensions and slower in acidic suspensions compared with neutral buffers. These results suggest that temperature and pH are factors that influence the extent of MB photosensitization, and hence, the control of these factors will be necessary for MB phototreatment of plasma products in transfusion medicine.
Antiviral Agents↗
Photoinactivation of virus infectivity by hypocrellin A.
We investigated the photoinactivation of virus infectivity by hypocrellin A and its mechanism. The titers of vesicular stomatitis virus (VSV) and human immunodeficiency virus type 1 (HIV-1), both of which are enveloped viruses, were reduced upon illumination with hypocrellin A in a concentration-dependent manner, whereas canine parvovirus, a nonenveloped virus, was not killed. The removal of oxygen or addition of sodium azide or beta-carotene both inhibited VSV inactivation. Mannitol and superoxide dismutase had no effect on VSV inactivation. These results indicate that singlet oxygen was involved in the process of VSV inactivation. Of the three major VSV membrane proteins, peripheral membrane protein M was most damaged by the hypocrellin A phototreatment.
Animals↗
Potential involvement of both type I and type II mechanisms in M13 virus inactivation by methylene blue photosensitization.
We have investigated the mechanism of virus photoinactivation with methylene blue (MB) by conducting deuterium oxide (D2O), azide ion (N3-) and oxygen-dependent studies. Inactivation of M13 bacteriophage and singlet oxygen (1O2) generation by MB photosensitization were irradiation dose dependent. Inactivation of M13 was enhanced by D2O and inhibited by N3-, suggesting that 1O2 participates in M13 inactivation by MB photosensitization. However, N3- did not inhibit M13 inactivation completely. On the other hand, deoxygenating the reaction solution still caused 52-67% of M13 inactivation observed in the presence of oxygen. These results suggest that 1O2-mediated (Type II) and sensitizer-mediated (Type I) reactions may both play roles in M13 inactivation by MB photosensitization.
Antiviral Agents↗
Spontaneous haemothorax caused by costal exostosis.
We report a case of spontaneous haemothorax in a 19 year old boy with an exostosis of the left second rib. It may have been caused by nontraumatic rupture of markedly dilated pleural vessels, as a result of long-standing friction between the exostosis and the pleura. This is the first report of spontaneous haemothorax, without penetrative injury to the pleura or the diaphragm, in a patient with hereditary multiple exostosis.
Adult↗
[Effect of extracellular magnesium on reperfused rat heart and intracellular calcium concentration of the myocardium].
Isolated rat hearts were subjected to 30 min global ischemia followed 20 min reperfusion with various concentration of Mg2+ Krebs-Henseleit-bicarbonate buffer (KHB buffer) (Mg2+:1.2 mM, 2.5 mM, 5 mM, 10 mM) and 20 min reperfusion with original KHB buffer (Mg2+:1.2 mM) at 37 degrees C, respectively. Cardiac function and the incidence of ventricular arrhythmia were measured during pre-ischemia and reperfusion, and intracellular Ca2+ concentration was measured during pre-ischemia, ischemia and reperfusion period. The hearts reperfused with 1.2 mM Mg2+ presented a significantly higher frequency of ventricular fibrillation (VF) and ventricular tachycardia (VT) than the other groups. Percent recoveries of LVDP (Left ventricular developed pressure) at the Mg2+ concentration of 1.2, 2.5, 5, 10 mM after 40 min reperfusion were 64.3 +/- 5.7%, 108.4 +/- 6.1%, 100.4 +/- 6.1%, 101.5 +/- 5.5%, respectively. Intracellular Ca2+ concentration of the hearts with Mg2+ 1.2 mM revealed 248.9 +/- 15.6% at reperfusion, and that the other groups did not increased during reperfusion. These data suggest that extracellular Mg2+ inhibits reperfusion arrhythmia and Ca2+ overload during reperfusion, and improves cardiac function of reperfused heart.
Animals↗
Higher prevalence of Borna disease virus infection in blood donors living near thoroughbred horse farms.
It is believed that Borna disease virus (BDV), an etiological agent of progressive polioencephalomyelitis in horses and sheep, is closely associated with psychiatric disorders in humans since the prevalence of BDV is higher in psychiatric patients than in blood donors. We investigated whether or not BDVs in humans are derived from infected domestic animals, by characterizing the BDVs in blood donors and horses derived from the same region of Hokkaido island, Japan. The seroprevalences (2.6 to 14.8%) of BDV were significantly higher in the blood donors from four regions where most horse farms are concentrated, compared with only 1% in the blood donors from Sapporo, the largest city in Hokkaido.BDV RNA was also detected in peripheral blood mononuclear cells from most of the seropositive horses and blood donors by nested reverse transcriptase-polymerase chain reaction. These findings support that BDV may be horizontally transmitted, at least in part, from infected horses to humans.
Animals↗
Quantitative analysis of human multidrug resistance 1 (MDR1) gene expression by nonisotopic competitive reverse transcriptase polymerase chain reaction assay.
We have established competitive reverse transcriptase polymerase chain reaction (RT-PCR) assay for the quantification of MDR1 mRNA encoding P-glycoprotein (P-gp) by analyzing leukemia sublines of MOLT-3 with various expression of MDR1. The expression was quantified by simultaneous RT-PCR of cellular RNA with decreasing amounts of heterologous competitor RNA, which shares the MDR1 primer sequences with the cellular MDR1 mRNA, but yields a different-sized PCR product. This allows resolution of the amplified cDNA fragments. The amounts of MDR1 mRNA measured by the assay were accurate and reproducible over wide range, and were determined as 31.6, 100, and 316 amol/microgram total RNA in MOLT-3/TMQ70, MOLT-3/ TMQ800, and MOLT-3/VCR1,000, respectively. The relative ratio of MDR1 mRNA measured by the competitive RT-PCR among three sublines was similar to that of MDR1 transcript determined by Northern analysis (1:4:12) and to that of P-gp measured by flow cytometry (FCM) analysis. In mononuclear cells from patients with leukemia, MDR1 mRNA could be sufficiently quantified by the competitive RT-PCR established, while FCM assay could scarcely detet P-gp. This study demonstrated that the competitive RT-PCR assay using heterologous competitor RNA is a rapid, reliable, and non-radioactive procedure and is acceptable for the evaluation of MDR1 expression in clinical samples.
ATP Binding Cassette Transporter, Subfamily B, Mem↗
[Blood components: indication and notice of transfusion].
The total number of blood donors in 1996 was 6 millions, and the number of 200 ml whole blood donors was 2.16 million(35.7%), whereas the numbers of 400 ml and apheresis donors were 2.66 million(44.1%), and 1.22 million(20.2%) respectively. From the donated blood, about 18.78 million units(1u: equivalent to 200 ml WB derived) of blood components were prepared and used for blood transfusion. Currently, whole blood is separated and prepared into MAP red cell concentrates and FFP, and all platelet concentrates are prepared from apheresis donations. In 1996, MAP red cell concentrates occupied 30.5% of all blood supply for transfusion, whereas FFP occupied 27.7% and PC occupied 40.2%.
Blood Component Removal↗
[Mistyping of ABO grouping by polyagglutination].
Polyagglutination is a phenomenon that a sample of patient's red blood cells is agglutinated by most of normal human sera. In patients with bacterial infection or hematological diseases, red cells may become agglutinable due to an exposure of antigens (cryptoantigen) that are usually hidden as submembrane structures of normal red cells. Most of normal sera contain natural antibodies to the corresponding antigens. Polyagglutination can cause apparent discrepancies between ABO antigen and antibody tests with the patient's sample, resulting in mistyping of ABO grouping. In some cases, polyagglutination is observed only by the minor test of cross-matching without showing the discrepancies. Recently polyagglutination has been rarely seen probably because of increasing use of monoclonal antibodies and dispensing minor test for cross-matching. Because no obvious case of adverse reaction by polyagglutination through transfusion is recently reported, clinical significance of polyagglutination seems extremely low.
ABO Blood-Group System↗
[Development and clinical application of the artificial blood as the oxygen carriers].
The artificial oxygen carrier first applied in clinical treatment was Fluosol-DA, which is one of the perfluoro-chemicals. However it is not used now because of low oxygen carrying ability and immunological disturbance. On the contrary, outdated human hemoglobin is currently used by many researchers who are challenging to develop artificial oxygen carriers. There are two types of hemoglobin based oxygen carriers, acellular and cellular types. The former type oxygen carrier is produced by modifying the outdated hemoglobin, and in the later case, the outdated hemoglobin is encapsulated by liposome. At present, diaspirin crosslinked hemoglobin(DCLHb) by Baxter Healthcare and Hemosol, which is glutaraldehyde intermolecular conjugated hemoglobin by Northfield, are under phase III and phase II clinical studies respectively, so the time will come soon when these oxygen carriers are clinically used.
Blood Substitutes↗