Types Of Red Blood Cells Research Articles

Lectins Associated With the Feeding Organs of the Oyster Crassostrea virginica Can Mediate Particle Selection

Despite advances in the study of particle selection in suspension-feeding bivalves, the mechanisms upon which bivalves rely to discriminate among particles have not been elucidated. We hypothesized that particle sorting in suspension-feeding bivalves could be based, in part, on a biochemical recognition mechanism mediated by lectins within the mucus that covers the feeding organs. Using Crassostrea virginica, the Eastern oyster, our investigations demonstrated that lectins from oyster mucus can specifically bind several microalgal species as well as different types of red blood cells (RBC), triggering their agglutination. Agglutination of microalgal species and RBC varied with the source of mucus (gills vs. labial palps). Hemagglutination and hemagglutination inhibition assays emphasized that mucus contains several lectins. In feeding experiments, Nitzschia closterium and Tetraselmis maculata were separately incubated with mucus before being fed to oysters. Results showed that pre-treating these microalgae with mucus significantly alters the ability of oysters to sort particles. In another experiment, oysters were fed a mixture of microspheres coated with either bovine serum albumin (BSA) or glucosamide-BSA. Results show that oysters preferentially ingest microspheres with bound carbohydrates, highlighting probable interactions between lectins and carbohydrates in the mechanisms of microalgae recognition. This study confirms the presence of lectins in mucus that covers the feeding organs of oysters and suggests a new concept with regard to particle processing by suspension-feeding bivalves: specific interactions between carbohydrates on the surface of particles and lectins within the mucus mediate the selection and rejection processes.

False-positive reactions of some monoclonal anti-c reagents

Cross-reactivities of monoclonal reagents for red blood cell (RBC) typing are seen very rarely, e.g. in some reagents for testing of ABO or Lewis antigens. We report on two patients in whom we observed weak reactions using a monoclonal anti-c reagent containing clone MS35, but no reactions with anti-c reagents containing other monoclonal or polyclonal antibodies. To resolve this discrepancy, we studied RHCE exon 1 (Ex1) and 2 from genomic DNA of one patient and performed quality controls of the false-positive reacting anti-c reagent. RHCE Ex1 showed no abnormalities as well as RH Ex2 examined with primers specific for Ex2 D/C. No amplification product of RH Ex2 was received with primers specific for c. A titration study with untreated, papain-treated and sialidase-treated adult and newborn RBCs showed anti-i reactivity of the false-positive reacting reagent. This reactivity could not be removed by absorption with c-negative newborn RBCs without reducing the anti-c titre in the same way, indicating a cross-reactivity. Some manufacturers give a remark on a possible cold agglutinin activity of their monoclonal anti-c reagents in the instruction leaflet, but in order to avoid such irritation, we recommend to remove this cross-reactivity by dilution during the manufacturing process.

Impacts of Papain and Neuraminidase Enzyme Treatment on Electrohydrodynamics and IgG-Mediated Agglutination of Type A Red Blood Cells

The stability of native and enzyme-treated human red blood cells of type A (Rh D positive) against agglutination is investigated under conditions where it is mediated by immunoglobuline G (IgG) anti-D antibody binding. The propensity of cells to agglutinate is related to their interphasic (electrokinetic) properties. These properties significantly depend on the concentration of proteolytic papain enzyme and protease-free neuraminidase enzyme that the cells are exposed to. The analysis is based on the interpretation of electrophoretic data of cells by means of the numerical theory for the electrokinetics of soft (bio)particles. A significant reduction of the hydrodynamic permeability of the external soft glycoprotein layer of the cells is reported under the action of papain. This reflects a significant decrease in soft surface layer thickness and a loss in cell surface integrity/rigidity, as confirmed by nanomechanical AFM analysis. Neuraminidase action leads to an important decrease in the interphase charge density by removing sialic acids from the cell soft surface layer. This is accompanied by hydrodynamic softness modulations less significant than those observed for papain-treated cells. On the basis of these electrohydrodynamic characteristics, the overall interaction potential profiles between two native cells and two enzyme-treated cells are derived as a function of the soft surface layer thickness in the Debye-Hückel limit that is valid for cell suspensions under physiological conditions (approximately 0.16 M). The thermodynamic computation of cell suspension stability against IgG-mediated agglutination then reveals that a decrease in the cell surface layer thickness is more favorable than a decrease in interphase charge density for inducing agglutination. This is experimentally confirmed by agglutination data collected for papain- and neuraminidase-treated cells.

An autoanti‐Kpb immunoglobulin M that simulates antigen suppression

Patients may present with an antibody against a blood group antigen, a negative direct antiglobulin test (DAT), and a null phenotype. Typically, this represents an alloantibody in a null individual. However, on occasion, the antibody disappears coincident with conversion to a positive red blood cell (RBC) phenotype. This has been called antigen loss, antigen suppression, or weakened antigenicity. Herein, a unique serologic profile that mimics this pattern, when in fact antigen loss did not occur, is described. RBCs and serum were analyzed using a gel microtyping system and flow cytometry. Genomic DNA was amplified by polymerase chain reaction and sequenced. Initially, an anti-Kp(b) was detected in MTS gel, RBCs typed K-k-Kp(b-), and the DAT was negative for immunoglobulin G (IgG). Later, the anti-Kp(b) disappeared and RBCs phenotyped as K-k+Kp(b+). Analysis of initial specimens by flow cytometry identified an immunoglobulin M (IgM) anti-Kp(b) with a positive IgM-specific DAT; eluates contained an anti-Kp(b) at immediate spin. Supporting the presence of the Kell glycoprotein, RBCs agglutinated with anti-Js(b). Sequencing showed homozygosity for Kp(b) with no mutations surrounding the Kp(b) polymorphism. In antigen loss, antibody masking is excluded by a negative DAT. However, because typical DAT reagent does not detect IgM, such reasoning was inaccurate in the current case. In addition, an anti-Kp(b) resulted in RBCs typing k-, even though no anti-k was detected. Overall, this case suggests that an IgM may mask adjacent epitopes and illustrates the potential to mistake a non-IgG autoantibody as antigen loss.

Glutathione synthesis by red blood cells in type 2 diabetes mellitus

Oxidative stress is implicated in the pathogenesis and complications of type 2 diabetes mellitus (NIDDM). Glycoxidation may damage the enzymes that synthesise glutathione (GSH), an endogenous intracellular antioxidant. Erythrocytes (RBCs) taken from NIDDM subjects, and non-diabetic controls, were GSH-depleted using 1-chloro-2,4-dinitrobenzene, incubated in a solution containing GSH-rebuilding substrates, and sampled for GSH using a 5,5′-γ-dithiobis-(2-nitrobenzoic acid)/enzymatic recycling procedure. NIDDM subjects, on average, had the same GSH concentration and synthesising ability as non-diabetic controls, indicating normal function of the synthesis enzymes. A positive correlation between synthesis and concentration of GSH seen in non-diabetic controls did not exist in NIDDM, due to their putatively larger oxidative load. The results, to the best of our knowledge, provide the first evidence that, despite a higher oxidative load, intact RBCs from NIDDM subjects are able to synthesise GSH normally. It is hypothesised that increased rates of GSH synthesis would maintain a normal steady-state GSH concentration.

Nanodiagnostics performed on human red blood cells with atomic force microscopy

Atomic force microscopy can yield valuable information concerning basic physical properties as well as alterations of human red blood cells. Erythropoietin is a hormone that is naturally produced in the kidney to stimulate the growth of red blood cells. Administration of genetically engineered synthetic erythropoietin stimulates the production of additional red blood cells. Therefore erythropoietin is used for blood doping in serious sports. The present study aims at investigating any differences in structure and stiffness of red blood cells which are produced body own or with synthetic erythropoietin. The samples are prepared via standard methods, and atomic force spectroscopy with trigger forces of three micronewtons is performed in ambient air. The penetration depth does not reveal statistically relevant differences in the two types of red blood cells. Furthermore, cells with a penetration depth four times as large as healthy ones are encountered in the samples of one donor. Subsequent medical examination revealed a rare type of diabetes. Atomic force spectroscopy shall serve as fast screening method for nanodiagnostics of diseases that alter surface nanomechanical properties.

Deletion of the dominant autoantigen in NZB mice with autoimmune hemolytic anemia: effects on autoantibody and T-helper responses

The mechanisms underlying apparently spontaneous autoimmune diseases, such as autoimmune hemolytic anemia (AIHA) in New Zealand Black (NZB) mice, are unknown. Here, we determine the contribution of the dominant red blood cell (RBC) autoantigen, the anion exchanger protein Band 3, to the development of NZB autoimmune responses. The approach was to prevent Band 3 expression in NZB mice by disrupting the AE1 gene. AE1(-/-) NZB mice produced RBC autoantibodies at the same levels as the wild-type strain, but they differed in recognizing antigens that correspond to glycophorins, rather than Band 3. Splenic T-helper (Th) cells from wild-type NZB mice proliferated strongly against multiple Band 3 peptides, particularly the dominant epitope within aa861-874. This helper response was severely attenuated in AE1(-/-) animals, leaving only weak proliferation to peptide aa861-874. The results demonstrate that the defect in self-tolerance in NZB AIHA is directed to the RBC type, and is not specific for, or dependent on, Band 3. However, the predisposition to RBC autoimmunity may be focused onto Band 3 by weak Th cell cross-reactivity between the helper dominant epitope and an exogenous antigen. The redundancy of the major autoantigen illustrates the requirement for specific therapy to induce dominant forms of tolerance, such as T-cell regulation.

Formation of dimethylthioarsenicals in red blood cells

The bladder and skin are the primary targets for arsenic-induced carcinogenicity in mammals. Thioarsenicals dimethylmonothioarsinic (DMMTA V) and dimethyldithioarsinic (DMDTA V) acids are common urinary metabolites, the former being much more toxic than non-thiolated dimethylarsinic acid (DMA V) and comparable to dimethylarsinous acid (DMA III) in epidermoid cells, suggesting that the metabolic production of thioarsenicals may be a risk factor for the development of cancer in these organs. To reveal their production sites (tissues/body fluids), we examined the uptake and transformation of the four dimethylated arsenicals by incubation with rat and human red blood cells (RBCs). Although DMA V and DMDTA V were not taken up by either type of RBCs, DMA III and DMMTA V were taken up by both (more efficiently by rat ones), though DMMTA V was taken up slowly, and then the arsenic transformed into DMDTA V was excreted from both types of animal RBCs. On the other hand, although DMA III taken up rapidly by rat RBCs was retained in the RBCs, that taken up by human RBCs was immediately transformed into DMMTA V and then excreted into the incubation medium without being retained in the RBCs. In a separate experiment, arsenic remaining in primary rat hepatocytes after incubation with 1.5 μM DMA III was recovered from the incubation medium in the forms of DMA V and DMMTA V in the presence of human RBCs, but not in the presence of rat RBCs (in which the arsenic was bound to hemoglobin). Thus, DMMTA V was detected in the medium only in the presence of human RBCs and increased with incubation time. It was proposed that arsenic is excreted from hepatocytes into the bloodstream in the form of DMA III and then taken up by RBCs in humans, where it is transformed into DMMTA V and then excreted again into the bloodstream.

High-Speed Mass Analysis of Whole Erythrocytes by Charge-Detection Quadrupole Ion Trap Mass Spectrometry

Herein, we report an application of charge-detection quadrupole ion trap mass spectrometry to the measurement of total dry masses of mammalian and poultry erythrocytes evaporated/ionized by laser-induced acoustic desorption. The method is rapid and widely applicable. Eight different types of red blood cells (RBCs) have been successfully analyzed, including those of human, goat, cow, mouse, pig, and chicken. The measured mean masses (weights per corpuscle) range from 0.58 x 10(13) Da (9.6 pg) of goat RBCs to 2.80 x 10(13) Da (46.5 pg) of chicken RBCs. The total dry weights determined for human RBCs from a healthy male adult, a patient with iron-deficiency anemia, and a patient with thalassemia are 34.8, 28.8, and 20.6 pg, respectively. These weights, except that of thalassemia, are all approximately 10% higher than their corresponding mean corpuscular hemoglobin values determined by a commercial automated hematology analyzer. The mass distribution profiles of the cells are all near-Gaussian, with a standard deviation of 15% for the normal human RBCs. The deviation increases significantly to 20% for RBCs with thalassemia characteristics and 27% for RBCs with iron-deficiency anemia characteristics. All the observations are in accord with their corresponding mean corpuscular volume measurements, indicating an increase in anisocytosis (variation in RBC size) in the anemic samples. Our results suggest a broad and promising application of this new technology to high-speed mass analysis of RBCs and other biological whole cells as well.

Implications of ABO Error Rates in Proficiency Testing for Solid Organ Transplantation

Implications of ABO Error Rates in Proficiency Testing for Solid Organ Transplantation

SI14 Stripped Red Cells–Efforts to Eliminate A and B Antigens from the Blood Supply

Eliminating the risk for ABO‐incompatible transfusion errors and simplifying blood logistics by creating an ABO‐universal blood inventory is a challenging idea but not a new one. In the early 1980s Goldstein and co‐workers at the New York Blood Centre pioneered the field of enzymatic conversion of blood group B red blood cells (RBC) to group O. They used native or recombinant α‐galactosidase from green coffee beans to remove the immunodominant galactose residues terminally located in the carbohydrate chains found on group B RBC. These enzyme‐converted O (ECO) RBC survived normally in the circulation of individuals independent of the blood group of the recipient. Small infusions were escalated to single, multiple and repeated RBC units. A successful phase II clinical trial in patients was reported in 2000 by Kruskall et al. However, economically unfavourable doses of enzyme were required to convert a unit of blood due to the low pH optimum of the enzyme. Conversion of blood group A cells was never achieved due to lack of A‐converting enzymes working at RBC‐friendly conditions. Also, the chemical nature of group A antigens is more complex due to the A1/A2 subgroups. Following screening of >2500 microorganisms we recently identified a novel family of bacterial exoglycosidases with specificities for the blood group A or B antigens and remarkably improved kinetic properties. Enzymatically converted group A and B RBC type as group O and can now be achieved under cost‐efficient and optimised conditions including neutral pH and room temperature incubation. Clinical trials to evaluate the safety and efficacy of ECO RBC are currently ongoing. Of the different strategies envisioned to create a universal blood component supply, the ECO concept is the only one for which clinical trials in humans have been performed. The presentation will review the current status of this exciting technology and its potential for introduction in the clinical component preparation laboratory. The speaker is a Visiting Associate Professor at Harvard Medical School, Boston, MA, USA and also a scientific consultant to the R&D biotech company ZymeQuest, Inc., Beverly, MA, USA. He gratefully acknowledges the significant and dedicated work performed by numerous members of the ECO team at Copenhagen University, Harvard Medical School, Lund University Hospital Blood Centre and the scientific staff at ZymeQuest.

Photoimmobilized array of panel cells for assay of antibodies

Antibodies in blood are checked with panel blood cells before blood transfusion. In this investigation, for the first time, a panel cell-microarray was prepared by using a photoimmobilization method. Different types of red blood cells were microarrayed on a plate. A water-soluble photoreactive polymer as a matrix was synthesized by the coupling reaction of azidoaniline with poly(2-methacryloyloxyethylphosphorylcholine- co-methacrylic acid). The polymer was mixed with cells and the mixtures were microspotted on substrate and photoirradiated after drying in air. For the antibody assay, monoclonal antibodies or human serum was added to the cell-arrayed plate and adsorbed antibodies were detected by horseradish peroxidase-labeled secondary antibody, which recognized the adsorbed antibodies. Antibodies specifically adsorbed on the immobilized cells as expected. The aggregation method has been available for this type of assay, but extensive experience was needed to apply it correctly. The method using a cell array will be useful for antibody detection.

Unfavorable effect of type 1 and type 2 diabetes on maternal and fetal essential fatty acid status: a potential marker of fetal insulin resistance

Pregestational maternal diabetes increases obesity and diabetes risks in the offspring. Both conditions are characterized by insulin resistance, and diabetes is associated with low membrane arachidonic (AA) and docosahexaenoic (DHA) acids. We investigated whether type 1 and type 2 diabetes in pregnancy compromise maternal and fetal membrane essential fatty acids (FAs). We studied 39 nondiabetic (control subjects), 32 type 1 diabetic, and 17 type 2 diabetic pregnant women and the infants they delivered. Maternal and cord blood samples were obtained at midgestation and at delivery, respectively. Plasma triacylglycerols and choline phosphoglycerides and red blood cell (RBC) choline and ethanolamine phosphoglyceride FAs were assessed. The difference in maternal plasma triacylglycerol FAs between groups was not significant. However, the type 1 diabetes group had lower plasma choline phosphoglyceride DHA (3.7 +/- 0.9%; P < 0.01) than did the control group (5.2 +/- 1.6%). Likewise, RBC DHA was lower in the type 1 [choline: 3.4 +/- 1.5% (P < 0.01); ethanolamine: 5.9 +/- 2.5% (P < 0.05)] and type 2 [choline: 3.5 +/- 1.6% (P < 0.05)] diabetes groups than in the control group (choline: 5.5 +/- 2.2%; ethanolamine: 7.5 +/- 2.5%). Cord AA and DHA were lower in the plasma (type 1: P < 0.01) and RBC (type 2: P < 0.05) choline phosphoglycerides of the diabetics than of the control subjects, and cord RBC ethanolamine phosphoglycerides were lower in DHA (P < 0.05) in both diabetes groups than in the control group. Diabetes (either type) compromises maternal RBC DHA and cord plasma and RBC AA and DHA. The association of these 2 FAs with insulin sensitivity may mean that the current finding explains the higher incidence of insulin resistance and diabetes in the offspring of diabetic women.

Clinical Study on Patients with Advanced Malignant Hematopoietic Disease by Non-T Cell Depleted Haploidentical Hematopoietic Stem Cells Transplantation.

objective: To investigate the effect of non-T cell depleted HLA haploidentical bone marrow transplantation(BMT) to patients with advanced malignant hematologic disease.Method: 26 patients with advanced malignant hematologic disease received non-T cell depleted haploidentic BMT. Donors included group A: offspring(5cases), sibling(3cases) and group B: mother(18cases). Hematologic Stem Cells(HSC) mobilization, collection and infusion: donors received G-CSF(300ug/12h×15d) from −5d, bone marrow cells were collected at −2d, PBSC were collected at −1d if CD34+ cells less than 4×106/kg of recipient's body weight. The average of CD34+ cells were 5.91(3.66~9.29) ×106/kg of recipient's body weight, the average of MNC were 10.05(2.10~29.70) ×108/kg of recipient's body weight. Preparative regimens: recipients were prepared for transplantation with different conditioning regimens according to the type of disease. Myeloid leukemia regimen: MeCCNU 250mg/m2 −10d, Ara-C 2g/m2 q12h, from −9d to −8d, Bu 4mg/kg, from −7d to −5d, Cy 1.8g/m2.d, from −4d to −3d. Lymphoblastic leukemia regimen: MeCCNU 250mg/m2 −8d, Total-body irradiation(TBI) 8Gy −7d, Ara-C 2g/m2 q12h, from −6d to −5d, Cy 1.8g/m2.d, from −4d to −3d. All the patients were given hydration, alkalization, and given mesna to prevent hemorrhage cystitis. GVHD prophylaxis: All patients received GVHD prophylaxis consisting of Cyclosporine(CSA), Methotrexate(MTX), Mycophenolate mofetil(MMF) and antithymocyle globulin(ATG). When GVHD developed, methylprednisolone(MP) was given at first, if the response was poor, anti-CD25 antibody was given to the recipients as quickly as possible and CSA was replaced with tacrolimus.[Results] All patients achieved sustained, full-donor-type engraftment. CD34+ cells in graft were (5.91±1.34)×106/kg of recipient's body weight, all patients attained successful neutrophil recovery at a median of (12.2±2.82) days (range, 10 to 20 days), recovery of platelet counts of more than 20×109/L was observed at a median of (20.73±7.62) days (range, 13 to 44 days). All the patients detected 99.9%~100% donor chimerism with FISH, recipient blood type of red blood cells transferred to donor blood type, STR showed donor chimerism exceeded 93%. 23 patients developed aGVHD in 26, the respective number of patients who developed grade I, II, III or IV aGVHD was 7, 7, 2, 7, the cumulative incidence of grade II–IV aGVHD was 65.4% and grade III–IV aGVHD was 34.6%. 12 patients developed cGVHD, the incidence was 46.2%. As of July 30 2005, 10 patients died, owing to pulmonary infection in 7, septicemia and HC in 1, leukoencephalopathy in 1, and recurrent disease in 1 case. 16 patients were alive and disease free with 2 years disease-free survival probabilities of 49.04%, 6 patients died in group A with 1 year disease-free survival probabilities of 25%, 4 patients died in group B with 2 years disease-free survival probabilities of 62.5%, p=0.0012 with Log-Rank testConclusion HLA-haploidentical BMT is a effective treatment for advanced malignant hematologic disease. Donor from mother is superior to the donor from sibling and offspring with lower aGVHD incidence, lower mortality and longer survival.

Identification of a High-Molecular-Weight Glycoconjugate from a Uruguayan Plant that Binds to the Tumor-Associated Tn Antigen

The Tn determinant (GalNAc-O.-Ser/Thr), one of the most specific human carcinoma–associated structures, can be identified using both monoclonal antibodies and lectins. In this work we have explored, for the first time, the presence of Tn-binding proteins in aqueous extracts of plants collected in Uruguay. A total of 21 extracts from plants belonging to 12 Phanerogam families were screened by an ELISA assay (competitive inhibition of anti-Tn antibody binding) and by hemagglutination (HAG) activity. Five of the extracts displayed binding to Tn residues, although only those extracts prepared from fruit and leaf from Myrsine coriacea. (Sw.) R. Br. ex Roem & Schult caused total inhibition of the binding activity of anti-Tn MAb 83D4. Considering that Myrsine coriacea. extracts did not display HAG activity against several types of normal red blood cells, we characterized the material with Tn-binding activity from these extracts. We purified this material from Myrsine coriacea. leaf extracts using perchloric acid treatment followed by affinity chromatography and reverse-phase high performance liquid chromatography (HPLC), conserving its Tn-binding activity. We found a high-molecular-weight glycoconjugate that has an apparent molecular mass of approximately 670 kDa, as judged by SDS-PAGE.

Adenoviral Overexpression of the Glutamylcysteine Ligase Catalytic Subunit Protects Pancreatic Islets against Oxidative Stress

The catalytic subunit of glutamylcysteine ligase (GCLC) primarily regulates de novo synthesis of glutathione (GSH) in mammalian cells and is central to the antioxidant capacity of the cell. However, GCLC expression in pancreatic islets has not been previously examined. We designed experiments to ascertain whether GCLC is normally expressed in islets and whether it is up-regulated by interleukin-1 beta (IL-1 beta). GCLC expression levels were intermediate compared with other metabolic tissues (kidney, liver, muscle, fat, and lung). IL-1 beta up-regulated GCLC expression (10 ng/ml IL-1 beta, 3.76 +/- 0.86; 100 ng/ml IL-1 beta, 4.22 +/- 0.68-fold control) via the p38 form of mitogen-activated protein kinase and NF kappa B and also increased reactive oxygen species levels (10 ng/ml IL-1 beta, 5.41 +/- 1.8-fold control). This was accompanied by an increase in intraislet GSH/GSSG ratio (control, 7.1 +/- 0.1; 10 ng/ml IL-1 beta, 8.0 +/- 0.5; 100 ng/ml IL-1 beta, 8.2 +/- 0.5-fold control; p < 0.05). To determine whether overexpression of GCLC increases the antioxidant capacity of the islet and prevents the adverse effects of IL-1 beta on glucose-induced insulin secretion, islets were infected with an adenovirus encoding GCLC. IL-1 beta significantly decreased glucose-stimulated insulin secretion (control, 123.8 +/- 17.7; IL-1 beta, 40.2 +/- 3.9 microunits/ml insulin/islet). GCLC overexpression increased intraislet GSH levels and partially prevented the decrease in glucose-stimulated insulin secretion caused by IL-1 beta. These data provide the first report of GCLC expression in the islet and demonstrate that adenoviral overexpression of GCLC increases intracellular GSH levels and protects the beta cell from the adverse effects of IL-1 beta.

가자(Terminalia chebula) 추출물이 마우스의 생리활성에 미치는 영향

가자 추출물을 취하여 사람, 돼지, 쥐 및 개 등의 3% 적혈구용액으로 응집력시험을 행한 결과 7가지 적혈구 모두에 렉틴 활성이 나타났으며 <TEX>$LD_{50}$</TEX>는 390 mg/kg으로 측정되었다. 생리 활성에 대한 영향을 알아보고자 생체 내외인성 요인에 의한 친전자성 물질로 생체내에서 독작용, 노화, 발암 및 면역 억제작용을 유발하는 원인 물질인 free radical생성에 관여하는 효소인 XO 및 AO의 활성을 측정 한 결과, XO 에서는 일주일간 매일 300 mg/kg의 용량으로 가자 추출물을 투여한 군이 정상군보다 5배 증가되는 결과를 나타내었고 AO에서는 정상군보다 시료 투여군이 2배 증가되는 결과를 나타내었다 glutathione은 단백질이나 DNA합성, amino acid의 이동 반응 및 thiol기의 저장 등과 같은 생물학적으로 중요한 여러 가지 반응에 직접 관여하는 물질이다[16〕. 이에 간장 조직의 glutathione농도를 측정한 결과 간장 독성의 유발로 인한 효소 활성은 정상군에 비하여 1주간 매일 300 mg/kg의 용량으로 시료 투여한 군의 효소 활성이 79% 감소됨을 볼 수 있었다. 체내의 여러 가지 해독반응과정에 관여하는 GST효소활성을 측정 한 결과 정상군에 비해 1주간 매 일 300 mg/kg의 용량으로 시료 투여한 군이 66%정도 감소된다는 결과를 볼 수 있었다. glutathione 합성에 관여하는 <TEX>$\gamma$</TEX>-GCS의 활성과 산화형 glutathione을 환원형 glutathione으로 환원시키는 GR의 활성을 관찰한 결과 가자 추출물 투여군이 정상군보다 GR의 활성은 80% 감소되었고, 합성에 관여하는 <TEX>$\gamma$</TEX>-GCS의 활성은 정상군과 비교할 때 약간의 감소만을 나타내 glutathione함량 변동에 크게 영향을 미치지 않는 것으로 생각된다. In this study, we investigated the effect of water, extract of Terminalia Chebula (TC) on physiological activity in mice. TC water extract showed hemagglutination against several different types of red blood cells. <TEX>$LD_{50}$</TEX> of TC extract was 390 mg/kg (po). Treatment of TC water extract orally administered 200, 300 mg/kg daily for one week. Hepatic cytosolic enzymes, xanthine oxidase and aldehyde oxidase activities were significantly increased comparison with normal group. Treatment of TC water extract increased hepatic malondialdehyde (MDA) formation, and reduced glutathione content. We also found that the decreased activities of glutathione S-transferase and glutathione reductase but was not affected activities of <TEX>$\gamma$</TEX>-glutamylcysteine synthetase after treatment of TC water extract. These results suggested that increase of the hepatic lipid peroxide is caused by glutathione reduction.

C-peptide, Na+,K(+)-ATPase, and diabetes.

Na+,K+-ATPase is an ubiquitous membrane enzyme that allows the extrusion of three sodium ions from the cell and two potassium ions from the extracellular fluid. Its activity is decreased in many tissues of streptozotocin-induced diabetic animals. This impairment could be at least partly responsible for the development of diabetic complications. Na+,K+-ATPase activity is decreased in the red blood cell membranes of type 1 diabetic individuals, irrespective of the degree of diabetic control. It is less impaired or even normal in those of type 2 diabetic patients. The authors have shown that in the red blood cells of type 2 diabetic patients, Na+,K+-ATPase activity was strongly related to blood C-peptide levels in non–insulin-treated patients (in whom C-peptide concentration reflects that of insulin) as well as in insulin-treated patients. Furthermore, a gene-environment relationship has been observed. The alpha-1 isoform of the enzyme predominant in red blood cells and nerve tissue is encoded by the ATP1A1 gene.Apolymorphism in the intron 1 of this gene is associated with lower enzyme activity in patients with C-peptide deficiency either with type 1 or type 2 diabetes, but not in normal individuals. There are several lines of evidence for a low C-peptide level being responsible for low Na+,K+-ATPase activity in the red blood cells. Short-term C-peptide infusion to type 1 diabetic patients restores normal Na+,K+-ATPase activity. Islet transplantation, which restores endogenous C-peptide secretion, enhances Na+,K+-ATPase activity proportionally to the rise in C-peptide. This C-peptide effect is not indirect. In fact, incubation of diabetic red blood cells with C-peptide at physiological concentration leads to an increase of Na+,K+-ATPase activity. In isolated proximal tubules of rats or in the medullary thick ascending limb of the kidney, C-peptide stimulates in a dose-dependent manner Na+,K+-ATPase activity. This impairment in Na+,K+-ATPase activity, mainly secondary to the lack of C-peptide, plays probably a role in the development of diabetic complications. Arguments have been developed showing that the diabetesinduced decrease in Na+,K+-ATPase activity compromises microvascular blood flow by two mechanisms: by affecting microvascular regulation and by decreasing red blood cell deformability, which leads to an increase in blood viscosity. C-peptide infusion restores red blood cell deformability and microvascular blood flow concomitantly with Na+,K+-ATPase activity. The defect in ATPase is strongly related to diabetic neuropathy. Patients with neuropathy have lower ATPase activity than those without. The diabetes-induced impairment in Na+,K+-ATPase activity is identical in red blood cells and neural tissue. Red blood cell ATPase activity is related to nerve conduction velocity in the peroneal and the tibial nerve of diabetic patients. C-peptide infusion to diabetic rats increases endoneural ATPase activity in rat. Because the defect in Na+,K+-ATPase activity is also probably involved in the development of diabetic nephropathy and cardiomyopathy, physiological C-peptide infusion could be beneficial for the prevention of diabetic complications.

Biological characteristics and pathogenicity of avian Escherichia coli strains

Fifty avian (chicken) pathogenic Escherichia coli strains (APEC) isolated from individuals suffering from omphalitis, septicaemia and swollen head syndrome, and 30 strains isolated from healthy chickens were studied regarding their biological characteristics such as serogroups, haemolysin, colicin, cytotoxin, toxin and siderophore production, adhesion capacity to in vitro cultivated cells, and absorption of Congo red dye. Serotyping demonstrated that most of the omphalitis and normal strains were untypable, whereas most of the septicaemic strains were either untypable or rough. There was no prevalent serogroup among the pathogenic strains studied. The capacity for adhesion and invasion of in vitro cultured cells (HeLa, HEp-2, KPCC), as well as the agglutination of different types of red blood cells and the LD 50 of each strain were also evaluated. No correlation was observed between the biological characteristics and pathogenicity, except that colicin was characteristically produced by swollen head syndrome E. coli strains. No correlation was found between adhesion or haemagglutination patterns and pathogenicity. Only six of the 50 strains revealed invasive capacity and the strain that best invaded the cell lines was the one with the lowest LD 50.

P-selectin mediates the adhesion of sickle erythrocytes to the endothelium.

The adherence of sickle red blood cells (RBCs) to the vascular endothelium may contribute to painful vaso-occlusion in sickle cell disease. Sickle cell adherence involves several receptor-mediated processes and may be potentiated by the up-regulated expression of adhesion molecules on activated endothelial cells. Recent results showed that thrombin rapidly increases the adhesivity of endothelial cells for sickle erythrocytes. The current report presents the first evidence for the novel adhesion of normal and, to a greater extent, sickle RBCs to endothelial P-selectin. Studies of the possible interaction of erythrocytes with P-selectin revealed that either P-selectin blocking monoclonal antibodies or sialyl Lewis tetrasaccharide inhibits the enhanced adherence of normal and sickle cells to thrombin-treated endothelial cells. Both RBC types also adhere to immobilized recombinant P-selectin. Pretreating erythrocytes with sialidase reduces their adherence to activated endothelial cells and to immobilized recombinant P-selectin. Herein the first evidence is presented for the binding of normal or sickle erythrocytes to P-selectin. This novel finding suggests that P-selectin inhibition be considered as a potential approach to therapy for the treatment of painful vaso-occlusion in sickle cell disease.