Antigens Protected Functional Red Blood Cells By The Membrane Grafting Of Compact Hyperbranched Polyglycerols

Red blood cell (RBC) transfusion is vital for the treatment of a number of acute and chronic medical problems such as thalassemia major and sickle cell anemia ^1-3. Due to the presence of multitude of antigens on the RBC surface (~308 known antigens ⁴), patients in the chronic blood transfusion therapy develop alloantibodies due to the miss match of minor antigens on transfused RBCs ^{4, 5}. Grafting of hydrophilic polymers such as polyethylene glycol (PEG) and hyperbranched polyglycerol (HPG) forms an exclusion layer on RBC membrane that prevents the interaction of antibodies with surface antigens without affecting the passage of small molecules such as oxygen ,glucose, and ions³. At present no method is available for the generation of universal red blood donor cells in part because of the daunting challenge presented by the presence of large number of antigens (protein and carbohydrate based) on the RBC surface and the development of such methods will significantly improve transfusion safety, and dramatically improve the availability and use of RBCs. In this report, the experiments that are used to develop antigen protected functional RBCs by the membrane grafting of HPG and their characterization are presented. HPGs are highly biocompatible compact polymers ^{6, 7}, and are expected to be located within the cell glycocalyx that surrounds the lipid membrane ^{8, 9} and mask RBC surface antigens^{10, 11}.     

Plasma estrone sulfate,clinical biochemistry,and milk yield of dairy cows carrying a fetus from a bull or its clone

The aim of this article was to compare plasma estrone sulfate (E₁SO₄), clinical biochemistry, and milk yield of dairy cows carrying a female fetus from a bull (BULL) or from its clone (CLONE), evaluating also the relationship between the former variables and the birth weight of the newborn. Sixteen recipient dairy Friesian heifers (10 BULL and 7 CLONE) received a female embryo, obtained by in vitro embryo production and sexing by polymerase chain reaction with the semen of the BULL or the CLONE. Blood samples on all cows were obtained before feed distribution in the morning from jugular vein from 4 weeks before to 4 weeks after calving, to be analyzed for metabolic profile. The samples from late gestation were also analyzed for E₁SO₄ concentration. To separately assess the effect of calf birth weight (CBW), data were categorized as follows: low (<39 kg; BWT-A), mid (39–46 kg; BWT-B), and high (>46 kg; BWT-C). The plasma concentrations of β-hydroxybutyric acid (BHB, P = 0.019), Na (P = 0.002), Cl (P = 0.026), strong cation–anion balance (P = 0.020), total bilirubin (P = 0.054), and α₁-globulin (P = 0.044) were higher in prepartum BULL recipients than those in CLONE, whereas BHB (P = 0.021) and Mg (P = 0.090) were higher in postpartum BULL recipients, while no differences were recorded in the remaining postpartum parameters. The CBW class had significant interaction with week of gestation on antepartum plasma estrone sulfate (P = 0.021), whereas CBW per se affected antepartum plasma BHB (P = 0.021), and nonesterified fatty acids (NEFA; P = 0.011) being higher in BWT-C which also had the lower NEFA concentration during postpartum. Milk yield was unaffected by the sire used, both for quantitative and qualitative aspects. Cows carrying heavier fetus (BWT-C) had a different lactation affected by month compared with the other 2 CBW groups. From these results, there were no differences between BULL and CLONE recipients. Estrone sulfate, BHB, and NEFA may be used to predict CBW and provide different nutritional management during gestation.     

Body growth, hematological profile, and clinical biochemistry of heifer calves sired by a bull or its clone

The aim of this paper was to compare body growth, hematological profile development, and clinical biochemistry in the female progeny of a sire with the female progeny of its clone. Sixteen Friesian female calves, 9 daughters from a tested bull (BULL) and 7 from its somatic cell nuclear transfer clone (CLONE) were monitored from birth to 60 wk of life. Body weight (BW), wither height (WH), hip height (HH), body length (BL), and hearth girth (HG) were measured at birth and 4, 8, 12, 16, 20, 24, 36, and 50 wk. Blood samples were taken from jugular vein at 12 to 48 h from birth and 1, 2, 3, 4, 8, 12, 16, 20, 24, and 36 wks of age, to be analyzed for hematological, serum protein, and metabolic profiles. At the same time, rectal temperature (RT) was recorded. Age at puberty was assessed on surviving heifers by measuring weekly plasma progesterone levels. Data were evaluated using a mixed model, taking into account the repeated measures in time on the calf. For each variable, different covariance structures were tested, choosing the best according to the Akaike's Information Criteria. Significant was set at P < 0.05, and a trend was considered for P < 0.10. At 24 wk of age, WH was lower in CLONE daughters than BULL daughters. Around 20 wk of age, there was a trend for lower BW in CLONE daughters than BULL daughters, confirmed from differences in HG. There was no difference in RT due to sire effect. Blood glucose concentration decreased in both groups during the first 4 wk of life; at birth, only a trend for higher blood glucose in CLONE daughters was recorded, whereas an opposite trend was observed for plasma creatinine. Total leukocyte count did not differ between progenies. Circulating lymphocytes tended to be lower in CLONE than BULL daughters. The neutrophil: lymphocyte ratio tended to be higher in CLONE than BULL calves. No difference was demonstrated for erythrocyte features, whereas mean platelet volume tended to be lower in CLONE than BULL progeny. From these results, there were no differences between progenies from BULL and its clone that suggest welfare problems in the first 6 mo of life.     

Long-term safety evaluation of a novel oxygen-coordinated niacin-bound chromium (III) complex

Chromium (III) is an essential micronutrient required for normal protein, fat and carbohydrate metabolism, as well as helps insulin metabolize fat, turn protein into muscle and convert sugar into energy. A broad spectrum of research investigations including in vitro, in vivo and clinical studies demonstrated the beneficial effects of novel oxygen- coordinated niacin-bound chromium (III) complex (NBC) in promoting glucose-insulin sensitivity, lipid profile, cardioprotective ability and lean body mass. This study examined the long-term safety of NBC by orally administering either 0 or 25 ppm or the human equivalency dose of 1000 microg elemental chromium (III) as NBC per day for 52 consecutive weeks to male and female Sprague-Dawley rats. Animals of each group and each gender were sacrificed on 26, 39, or 52 weeks of treatment. Body weight, physical and ocular health, feed and water intake, selected organ weights as such and as a percentage of liver and brain weight, hepatic lipid peroxidation and DNA fragmentation, hematology and clinical chemistry, and histopathological evaluations were conducted. At 26, 39, or 52 weeks of treatment, body weight gain was significantly reduced by 7.7%, 8.1% and 14.9% in male rats, and 5.5%, 11.4% and 9.6% in female rats, respectively, in the NBC treatment groups. No significant changes were observed in hepatic lipid peroxidation and DNA fragmentation, hematology and clinical chemistry, and histopathological evaluation between control and NBC groups at these time points. These findings, thus far, are in agreement with the subchronic studies in terms of the safety of NBC.     

Changes in hematological parameters in free-living pigeons (Columba livia f. urbana) during the breeding cycle

The blood parameters—red blood cell (RBC) count, hematocrit (Ht), hemoglobin concentration (Hb), mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), and mean corpuscular hemoglobin concentration (MCHC)—were studied for the first time in free ranging pigeons Columba livia f. urbana. The aim of the study was to establish a set of reference values for this ubiquitous urban species and to examine a potential influence of the factors such as sex and phase of the breeding cycle on the hematological parameters. Blood was sampled from the adult individuals of both sexes during the breeding cycle. Significant variations in Ht and Hb were observed, while RBC count remained unchanged. The lower hematocrit value and hemoglobin concentration found in both males and females during molt probably resulted from the increase of plasma volume not accompanied by an increase in RBC. On the other hand, a significant physiological stress of nutritional deficiency during this energy-consuming stage may manifest itself in the decreased Ht and Hb values. The higher values of Ht and Hb during the laying phase could be related to the dehydration status. There were no overall differences in MCV, MCH, and MCHC values in either of the breeding stage. A lack of sex dimorphism in the measured and calculated blood parameters was apparent. Data collected herein contribute to the better understanding of general physiology of the ubiquitous urban species. The knowledge of variation in the blood indexes with respect to sex and breeding stage is crucial before blood parameters can provide an useful information on physical condition of the bird.     

Isolation and purification of a squamous cell carcinoma of the head and neck-associated antigen identified by autologous antibody

We have previously shown that detection of autologous antibody activity to squamous cell carninoma of the head and neck many be augmented by dissociation in immune complexes. Western blot analysis with autologous antibody has identified a 60 kDa squamous cell carcinoma of the head and neck-associated antigen in spent media and immune complex-dissociated serum ultrafiltrate not recognized by normal human area. Antigen-containing fractions of spent media were eluted from anion exchange columns immediately after serum albumin indicating that the antigen has an acidic PI < 4. Preparative purification of the squamous cell carcinoma antigen was accomplished by anion exchange of concentrated spent media (protein concentration 300 mg/ml) followed by lectin affinity chromotography with a Triticum vulgaris column. A single 60 kDa band was detected by silver stain and Western blot in antigen-containing fractions eluted following lectin affinity chromotography and SDS-PAGE. Final concentration of the antigen was determined to be 1 μm/ml of protein with relative activity increased 1600 × over unfractionated spent media. We conclude that a squamous cell carcinoma of the head and neck-associated antigen, detected by autologous antibody, is an acidic kDa glycoprotein.     

Inhibition of natural killer cell lysis by natural killer-inhibitory substance: mechanism of suppression

The mechanism of suppression of NK-mediated lysis by a soluble product of peritoneal cells (NK-IS, natural killer-inhibitory substance) was investigated. Pretreatment of effector cells resulted in depressed NK lysis while pretreatment of targets had no effect, indicating suppression is due to alterations in effector cell function rather than changes in target cells. NK-IS had no effect on the formation of conjugates between effectors and NK-susceptible targets. When NK-IS was added to effector-target cell mixtures after the binding step had been successfully completed, ensuing lysis was significantly depressed, confirming that NK-IS inhibited a postbinding lytic event. The degree of suppression caused by NK-IS was directly related to the duration of exposure to the inhibitory molecule. In addition, a preliminary temperature-dependent step of binding to and/or intracellular entry of NK-IS into effectors is required before suppression can occur. NK-IS prevents the activation of NK cell lysis by interferon and Corynebacterium parvum and effectively inhibits lysis mediated by already activated effectors. The potent suppression of NK lysis and prevention of interferon and C. parvum-mediated activation of NK lysis by a soluble product of peritoneal cells may explain the extremely low level of NK effector cell function within the peritoneal cavity.     

The influence of exogenous fibronectin on blood granulocyte adherence to vascular endothelium in vitro

Fibronectin is a major cell surface and extracellular matrix glycoprotein. It binds to a variety of substrata and supports the attachment and spreading of a number of cell types. We have found that purified human plasma fibronectin can also support blood granulocyte adhesion to cultured human umbilical vein endothelial cells. This activity is protected by treatment of the fibronectin with a sulphhydryl-containing agent. The effect of granulocyte attachment was observed at fibronectin concentration of 100 ng/ml with maximum effect at a concentration of 10 μg/ml. The attached granulocytes retained a rounded appearance, compared with the flattening that occurs on attachment to plastic. Granulocytes attached poorly to cultured human vascular smooth muscle cells and no enhancement occurred when fibronectin was added. Immunofluorescence microscopy using monospecific rabbit anti-human fibronectin demonstrated that the sulphhydryl-treated fibronectin accumulated on the endothelial cell surface, forming aggregates on the apical surface by 3 h of continued incubation. Washed, cultured endothelial cells not exposed to fibronectin or exposed to untreated purified plasma fibronectin did not demonstrate an aggregation of cell-surface fibronectin.     

华南虎血液及生物化学某些指标的测定

用血液及生物化学的常规测定方法对６１例华南虎的血液常规,３０余例血液生化指标进行了分析测定,经生物学统计获得了华南虎的血液和生物化学的参考值。