Plasmodium yoelii: antibody response in resistant and susceptible mouse strains

The numbers of antigen-reactive antibody-secreting cells, levels of parasite antigen-specific serum antibodies and numbers of red blood cells staining positive for surface immunoglobulin were determined for susceptible and resistant mouse strains following infection with Plasmodium yoelii 17x. As a control, these parameters also were measured using antigen prepared from normal red blood cells. The relatively susceptible C57BL/6 mice produced more antigen-specific antibody-secreting cells and had higher levels of immunoglobulin positive red blood cells than did DBA/2 mice, but the DBA/2 mice had more antigen-specific IgG in their sera. Both mouse strains possessed cells secreting antibody reactive with soluble normal red blood cell antigen; however, C57BL/6 mice had more IgG positive unparasitized RBC than did DBA/2 mice. Despite possessing fewer antibody positive normal RBC, DBA/2 mice had significantly higher levels of serum antibodies that reacted with soluble red blood cell antigen. These data indicate that levels of serum antibody may not reflect the amounts of antibody produced and that use of any single assay to assess the magnitude of the antibody response may give rise to misleading results.     

Delaying childbearing: effect of age on fecundity and outcome of pregnancy.

OBJECTIVES--To study the age of the start of the fall (critical age) in fecundity; the probability of a pregnancy leading to a healthy baby taking into account the age of the woman; and, combining these results, to determine the age dependent probability of getting a healthy baby. DESIGN--Cohort study of all women who had entered a donor insemination programme. SETTING--Two fertility clinics serving a large part of The Netherlands. SUBJECTS--Of 1637 women attending for artificial insemination 751 fulfilled the selection criteria, being married to an azoospermic husband and nulliparous and never having received donor insemination before. MAIN OUTCOME MEASURES--The number of cycles before pregnancy (a positive pregnancy test result) or stopping treatment; and result of the pregnancy (successful outcome). RESULTS--Of the 751 women, 555 became pregnant and 461 had healthy babies. The fall in fecundity was estimated to start at around 31 years (critical age); after 12 cycles the probability of pregnancy in a woman aged greater than 31 was 0.54 compared with 0.74 in a woman aged 20.31. After 24 cycles this difference had decreased (probability of conception 0.75 in women greater than 31 and 0.85 in women 20.31). The probability of having a healthy baby also decreased--by 3.5% a year after the age of 30. Combining both these age effects, the chance of a woman aged 35 having a healthy baby was about half that of a woman aged 25. CONCLUSION--After the age of 31 the probability of conception falls rapidly, but this can be partly compensated for by continuing insemination for more cycles. In addition, the probability of an adverse pregnancy outcome starts to increase at about the same age.     

The best strategy of blood transfusion in patients with Rhnull syndrome

Rh_null syndrome is a very rare disease. Patients with this syndrome present with negative serological Rh typing of E, e, C, c, and D antigens. Only one study has previously discussed Rh_null syndrome in Chinese individuals. We experienced two patients with Rh_null syndrome in China, Rh genotypes being CcDEe in the first patient and CCDee in the second patient. The first patient was a pregnant woman (gravida 2, para 1) with a negative red blood cell (RBC) antibody screen test. The second patient was a middle-aged man, transfused with ccdee, ccdEe, and ccdee RBC products, the pre-transfusion specimen was negative and post-transfusion specimen was anti-c,e, respectively. The hemoglobin level continued to increase in the second patient after being transfused with ccdEe RBC products. In the first patient, the result of the antibody screen test was still negative after artificial abortion. In patients with Rh_null syndrome, RBC products that have the same Rh genotype as the patient can be safely transfused.     

自身抗体引起的ABO血型正反定型结果不一致

目的:对因自身抗体引起ABO血型正反定型结果不一致的疑难血标本进行血型鉴定和分析,探讨其原因和解决办法。方法:先用直接抗人球蛋白试验(DAT)和间接抗人球蛋白试验(IAT)确定ABO血型正反定型结果不一致的原因是由于自身抗体的存在,然后做吸收放散试验、抗体筛选试验等排除自身抗体的干扰以便血型的正确判定。结果:ABO血型正反定型结果不一致因自身抗体引起的有10例,其中温抗体7例,冷抗体3例,温抗体同时同种抗体阳性2例,冷抗体同时同种抗体阳性2例。结论:自身抗体会影响ABO血型的正确判定,选用合适的试验进行分析判断以提高血型鉴定的准确性。     

ABO血型正反定型及交叉配血实验在外科病人手术输血中应用

目的:探讨ABO血型正反定型及交叉配血实验在外科手术患者输血中的应用效果及影响因素。方法:选取我院自2017年2月-2019年2月收治的80例行ABO正反定型与交叉配血治疗的外科手术患者,记录ABO反定型与交叉配血不合的标本,使用2-Me处理被患者自身冷抗体凝集的红细胞,同时使用微柱凝胶法、凝聚胺法对血型不规则抗体以及特异性进行筛选和鉴定。分析ABO血型反定型不符合以及交叉配血不合的影响因素。结果:对正反定型完全无凝集反应的80例血清标本进行交叉配血实验,其中8例存在凝集反应,配血不合情况;导致外科手术患者输血中ABO血型反定型不符交叉配血不合的主要因素包括自身冷抗体、血型抗原性减弱、血型不规则抗体以及血型抗体效价减弱等。结论:ABO血型正反定型及交叉配血治疗中的患者中,大部分配血一致,少数的交叉配血不合,主要与自身冷抗体、血型抗原性减弱、血型不规则抗体以及血型抗体效价减弱等因素相关。     

Biochemical identification of the bovine blood group M' antigen as a major histocompatibility complex class I-like molecule

Absorption and elution experiments showed that it was impossible to separate antibodies against blood group factor M' from antibodies against bovine lymphocyte antigen (BoLA) A16 in an antiserum showing haemolytic activity against M' as well as lymphocytotoxic activity against BoLA-A16. To elucidate the structural relationship between BoLA-A16 and blood group antigen M', immunoprecipitation experiments on red and white cell lysates isolated from M'-A16 positive and negative cattle were carried out. These results showed that M_r 44 000 and M_r 12000 polypeptides can be precipitated from both red and white cells isolated from M'-A16 positive animals, whereas no bands were seen in M'-A16 negative animals in precipitations with the same antibody. Precipitation with a crossreacting human β₂-microglobulin (β₂-m) specific antibody confirmed a class-I-like structure associated with β₂-m on M' positive red cells and the absence of such a structure on M' negative red cells. Sequential precipitations gave analogous results. Proteolytic degradation by papain and V8 protease did not reveal any substantial difference between red and white M'-A16 positive cells, but a slight difference in the pI of the immunoprecipitable components of red and white cells was observed. All together, this indicates that either the blood group antigen M' is the BoLA-A16 class I antigen or M' and BoLA-A16 are two different class I polypeptides with the same relative mass, sharing identical epitopes and both associated with β₂-m. Comparable results were obtained with M₁ and BoLA-A24.     

Diaplacental passage of Sarcocystis antibodies in man and rats (author's transl)]

Sera of babies up to the age of 3 months were tested for Sarcocystis antibodies using the indirect immunofluorescence test (IIFT). In addition titre of the Sarcocystis antibody level of litters born to serologic Sarcocystis positive mother rats was compared to those of their mothers. The results are as follows: 1. 45 (= 14.6%) out of 308 sera from babies up to the age of 3 months reacted positively in the Sarcocystis antibody test. 2. 28 (= 62.2%) out of the 45 positive sera were from babies up to 2 weeks old, 13 (= 28.9%) were from babies older than 2 weeks but not more than 4 weeks old, and 2 (=4.4%) each were from babies whose ages ranged from 4 to 8, and 8 to 12 weeks respectively. 3. These babies acquired their Sarcocystis antibodies which decreased in the first 3 months of life from their mothers. 4. Litters born to serologic Sarcocystis positive mother rats also demonstrated Sarcocystis antibodies. The titres of these antibodies were at the same level as their mothers' at birth but reduced gradually so that most of these young rats were negative at the age of 3 months. 5. Suckling rats born to Sarcocystis negative mothers but positive fathers remained negative. 6. Serologic positive mother and father rats still demonstrated Sarcocystis antibodies in the sera at a time when their litters have become negative. 7. Sarcocystis antibodies could be passed onto the newborn from their positive mothers in both man and rats. 8. These antibodies were probably passed onto the newborn through the placenta but their passage through the colostrum and the mother's milk cannot be ruled out.     

Incidence of rhesus immunisation after genetic amniocentesis.

Of 655 Rh negative women without anti-D antibody in their serum at genetic amniocentesis, 361 delivered a Rh positive infant. Prophylactic treatment with anti-D immunoglobulin was not given at amniocentesis. The women were followed prospectively, being given a screening test for antibody after amniocentesis, at delivery, and six months later. Five of these 361 women yielded a positive test result due to anti-D antibody. The immunisation rate after genetic amniocentesis was no higher than the spontaneous immunisation rate during pregnancy. Four women who had two amniocenteses in the same pregnancy and 34 women who had amniocentesis in two consecutive pregnancies with Rh positive fetuses were not immunised. Among six women with anti-D antibody in their serum before amniocentesis the titre of antibody increased in three. Amniocentesis may have worsened the outcome of these pregnancies. These results suggest that the risk of immunisation in Rh negative women is small.     

Challenges in the Testing of Non-Heart-Beating Cadavers for Viral Markers: Implications for the Safety of Tissue Donors

Natural changes that occur in blood and tissue after death may result in false positive results in antigen and antibody detection tests performed to identify markers of viral infection in potential tissue donors. Such tissue, which might otherwise be acceptable for therapeutic purposes, would not meet current standards for safe tissue banking. This is especially important in the context of insufficiency in the tissue supply. In this study, a series of blood samples collected during routine post-mortem examination was assayed using a range of commercially available kits for the detection of HBsAg, anti-HCV and anti-HIV 1 + 2 antibody/antigen. Results of tests on 104 samples collected from 97 individuals indicate that some kits result in a higher number of initial reactive samples than others. Approximately 40% of samples were reactive in one or more HBsAg assay, less than 10% in at least one anti-HIV kit and only 1 sample at low level on an anti-HCV kit. Liver or lymph node samples from individuals whose serum sample gave reactive results in antigen/antibody assays were tested for viral nucleic acid in the corresponding nucleic acid amplification test. Only one individual’s sample was confirmed to test positive for HBsAg in a confirmatory neutralisation test and by nucleic acid amplification technology, and a second individual whose serum was scored reactive for anti-HCV, but negative for HBsAg, had a liver sample which was HBV DNA positive and HCV RNA negative. The results of the study indicate that antibody/antigen assays are not as specific as NAT using state of the art DNA extraction techniques. Both types of assay complement each other and used together will help assure the safety of tissues for transplantation.     

Hydralazine,antinuclear antibodies,and the lupus syndrome.

The incidence of patients with positive antinuclear antibody test results rose during three years of treatment with hydralazine. At the end of that period over half of the patients (both rapid and slow acetylators) had titres exceeding 1/20, but the rate of rise was faster in the slow acetylators than in the rapid. There was a significant relation between the cumulative dose of hydralazine and the proportion of patients found to have antinuclear factors. Fewer black patients had positive test results than white. Patients whose antinuclear antibody test results changed fron negative to positive during the study showed this change five to 26 months after beginning treatment. Some patients showed a substantial fall in antinuclear antibody titre even though hydralazine was continued. From these findings patients in whom test results for antinuclear antibody became positive during treatment with hydralazine need not have the drug stopped unless they have clinical features of the lupus syndrome.     

Iso-antibodies to red cell antigens in pigs' sera 3. The effect of maternal red cell iso-antibodies on the red cells of piglets

The effect of the red cell antibody, anti-Ea, on the red cells of piglets in four litters was studied. Although the antibody was absorbed from the colostrum by all the piglets, it had little effect on their packed cell volume, haemoglobin and red cell counts, and no differences were noted between Ea-positive and Ea-negative piglets in the same litter, despite the fact that red cells of the former were positive for the direct Coomb's test for up to a week after birth.
Anti-Ea was not detected in the serum of Ea-positive piglets, all of it apparently being taken up by their red cells, unlike the Ea-negative ones, in whose serum anti-Ea could be detected for up to fifteen weeks of age.     

Comparative evaluation of antibody positive titer by ELISA and IFA in Theileria annulata vaccinated cattle in Iran

An enzyme linked immunosorbent assay (ELISA) was used to evaluate antibody positive titer in vaccinated and non-vaccinated cattle using schizont infected myeloid cells as an antigen. The result was compared with indirect fluorescent antibody level in the same animals. For this study 116 milking cows, 95 vaccinated and 21 non-vaccinated, were bleeded in order to prepare sera. They were tested with both ELISA and IFA tests. 94 sera had positive antibody titer and 22 sera were negative through ELISA test but, with IFA test, only 89 sera showed positive antibody titer and 27 were negative. Thereby, it was concluded that the sensitivity and specificity of ELISA test in comparison with IFA test was 95.5% and 66.6% respectively. This study generally indicated that ELISA could be an effective test for sero-epidemiological investigations of bovine tropical theileriosis, and it is considered to be valid as an additional test to distinguish the vaccinated from the non vaccinated cattle in order to schedule vaccination programs.     

Anti-ζ Antibody Screening for α-Thalassemia Using Dried Filter Paper Blood

The most common α-thalassemia in Southeast Asian or Southern Chinese populations is the (- -^SEA) double α-globin deletion. Couples heterozygous for (- - ^SEA) have 25% risk for hydrops fetalis from loss of all four α-globin genes. The (- -^SEA) deletion spares the embryonic ζ-globin genes and causes traces of ζ-peptide to persist throughout life. A colorimetric monoclonal anti-ζ antibody test for raised ζ-peptide has detected the (- -^SEA) deletion in liquid blood samples, but not deletions of the entire α-globin region with loss of the ζ-globin genes. Eluates from dried blood spots had the same anti-ζ antibody color reaction as whole blood, even after storage at 4°C for up to 77 days. The anti-ζ antibody test was positive in 24 of 91 microcytic samples (mean corpuscular hemoglobin <24 pg), including four with iron deficiency; it was negative in 26 provisionally diagnosed α-thalassemia-1 heterozygotes and all 32 nonmicrocytic samples. Southern blot analysis and a specific SEA-polymerase chain reaction test confirmed that 18 anti-ζ antibody-positive samples and 1 anti-ζ antibody-negative sample had the (- -^SEA) deletion. Two anti-ζ antibody-negative microcytic samples had the (- -^Fil) total α-globin region deletion, 2 had single α-gene deletions, 22 others may also have had a total α-region deletion. Hence specificity was very high and sensitivity was 95%. The anti-ζ antibody test can detect the (- -^SEA) deletion in dried blood samples, even after prolonged storage. This simple inexpensive test can conveniently screen samples collected at a distance from a central laboratory.     

Infectious Mononucleosis and its Relationship to EB Virus Antibody: A JOINT INVESTIGATION BY UNIVERSITY HEALTH PHYSICIANS AND P.H.L.S. LABORATORIES

In October 1969 tests made on 1,457 students entering English universities and colleges showed that 57% already possessed antibody to EB virus. The students without antibody in these initial tests were retested seven months later and by then 12% had acquired antibody. In about one-third of them the acquisition of antibody was not associated with any illness. In about 20% respiratory and other illness had occurred, but these symptoms were almost equally frequent in students who had not acquired antibody. Nearly half had developed infectious mononucleosis. In students in whom the acquisition of EB virus antibody was associated with the clinical and haematological manifestations of infectious mononucleosis the Paul-Bunnell test was almost invariably positive. In contrast, when these manifestations were not associated with the acquisition of EB virus antibody the Paul-Bunnell test was always negative.Tests for cytomegalovirus antibody were also made on the students at entry. The proportion of students with this antibody was much less (30%) and only a small proportion (1·4%) of those without antibody had acquired cytomegalovirus antibody seven months later. In the only patient in whom the acquisition of cytomegalovirus antibody alone was associated with the clinical and haematological features of infectious mononucleosis the Paul-Bunnell test was negative.     

影响脐带血采集质量的相关性因素分析

目的回顾性分析影响脐带血采集质量的母婴因素和采集处理因素。 方法记录389份脐带血的采集量、母亲年龄、孕龄、新生儿体重、分娩方式、新生儿性别、胎次及脐带血采集至计数间隔以及采集方式。用KX-21型全自动血液分析仪进行细胞计数并计算有核细胞总数（TNC）。采用Pearson相关和Spearman秩相关进行相关性分析,采用t检验、Mann-Whitney U检验、方差分析及Kruskal-Wallis H检验进行分组比较,分析影响脐带血采集量和TNC的相关因素。? 结果脐带血采集量与TNC显著相关（r = 0.723,P < 0.001）,脐带血采集量大于80 ml时的TNC显著高于低体积者。在母婴因素中,母亲年龄与采集量及TNC差异均无统计学意义;孕龄与采集量负相关（r = -0.119,P = 0.019）,而与TNC正相关（r = 0.138,P = 0.007）,足月儿脐带血的TNC显著高于早产儿（P = 0.038）;婴儿出生体重与采集量及TNC均正相关（r = 0.236,P < 0.001;r = 0.275,P < 0.001）,体重较大婴儿脐带血的采集量和TNC均显著高于体重较小者（P?< 0.001）;剖宫产的脐带血采集量虽高于阴道分娩（P < 0.001）,但其TNC不及阴道分娩;男婴与女婴在脐带血采集量和TNC之间无显著差异。在采集处理因素中,脐带血采集至计数的时间间隔与采集量及TNC均无显著相关。 结论为提高脐带血的保存质量,应侧重选择胎儿体重较大、经阴道分娩的产妇作为脐带血供者,实验室应首先处理采集量较大的脐带血。     

Penicillin induced Haemolytic Anaemia

The case histories of two patients with penicillin-induced haemolytic anaemia are presented. One had received 20 mega units a day for 18 days, the other had received 20 mega units a day for two days and then 12 mega units a day for 25 days, before the haemolytic anaemia was diagnosed. Both had previously had courses of penicillin. A strongly positive direct antiglobulin reaction which appeared to be mainly due to IgG antibody was one of the main diagnostic features, and free IgG antipenicillin antibody was found in the serum of both patients. The haemolysis appeared to Lessen as soon as the drug was stopped, and the direct antiglobulin test became negative in 66–77 days.Twelve additional reported cases are reviewed. All had received high doses of penicillin and all had had penicillin previously. The lowest dose recorded was 10 mega units a day for 26 days. The incidence of anti-penicillin antibodies in a hospital population is given, and the mechanism of this type of haemolytic anaemia is discussed. Penicillin-induced haemolytic anaemia should be suspected in any patient receiving penicillin in high doses in whom there is a fall in the haemoglobin level.     

Bovine virus diarrhea virus in free-living deer from Denmark

Free-living deer are suggested as a possible source of infection of cattle with bovine virus diarrhea (BVD) virus. To examine this hypothesis blood samples from 476 free-living deer were collected during two different periods and tested for BVD virus and antibody in Denmark. In 1995-96, 207 animals were tested. These included 149 roe deer (Capreolus capreolus), 29 fallow deer (Dama dama), 20 red deer (Cervus elaphus) and one sika deer (Cervus sika). For the remaining eight animals no species information was available. In 1998-99, 269 animals were tested including 212 roe deer and 57 red deer. The animals were selected from areas with a relatively high prevalence of cattle herds with a BVD persistent infection status in 1997 and 1998. All 207 samples from 1995-96 were found antibody-negative except two samples from red deer. Only 158 of the 207 samples were tested for virus and were all found negative. Of the 269 samples from 1998-99 all but one were antibody negative. The positive sample was from a red deer. All samples were virus-negative. It appears that BVD infection does not occur in roe deer in Denmark. The presence of antibody in a few red deer from various districts in Jutland probably results from cattle to deer transmission, rather than spread among deer. Hence, the possibility of free-living deer as a source of infection for cattle in Denmark seems to be remote.     

A dot-immunobinding assay on nitrocellulose with psoralen inactivated Herpesvirus simiae (B virus)

An enzyme-immunoassay performed with Herpesvirus simiae (B virus) and H. simplex antigens inactivated with a psoralen derivative and long-wavelength ultraviolet light irradiation is described. Although B virus is a known human pathogen requiring extreme care in its handling, the use of inactivated antigens in the test allows its performance without biosafety containment. The test utilizes nitrocellulose sheets dotted with antigen for the assay of antibody against B virus in nonhuman primate sera. Antigen-antibody complexes are detected visually as red dots by the use of enzyme-conjugated antiglobulin second antibody and a substrate that produces an insoluble product. The test is more rapid, sensitive and specific than the serum neutralization test it is intended to replace. Of 150 macaque monkey sera tested, 83 were negative by the enzyme and neutralization tests, 56 were positive by both tests and 11 were positive by enzyme-assay but negative by neutralization. Positive sera reacted with both simian and human viral antigens in the enzyme assay but with greater intensity against B virus. Absorption with H. simplex removes reactivity with this virus without reducing the B virus response.     

Level of the A, B and H blood group glycosyltransferases in red cell membranes from patients with malignant hemopathies

Eight patients (4 suffering from acute myeloid leukemia) exhibiting a loss of ABO red cell antigens, as seen by a mixed-field reaction pattern in agglutination tests, were selected and examined for the level of the A, -B, -H blood group glycosyltransferases within membranes prepared from erythrocyte subpopulations (A or B positive and A or B negative red cells). A or B enzyme activities were largely decreased in membranes which had lost A or B antigens (A or B negative subpopulations) but were within normal level in membrane from cells which had not lost A or B antigens (A or B positive subpopulations). The H enzyme level which was frequently low in the serum was within normal limits in the membrane preparations examined. Since A or B negative subpopulations were normally glycosylated in vitro into A or B reactive structures, the results demonstrate that loss of A or B antigens is related to some alteration of the blood group gene products rather than to significant abnormalities of the membrane precursors.     

Evaluation of a Community’s Risk for Canine Parvovirus and Distemper Using Antibody Testing and GIS Mapping of Animal Shelter Intakes

This cross-sectional study aimed to identify where dogs with negative antibody tests to canine parvovirus (CPV) and canine distemper virus (CDV) originated when entering a community shelter, using a commercially available ELISA antibody test and Geographic Information Systems mapping. Of 2745 canines entering during a three-month period, 1056 test results were obtained. Dogs or puppies weighing over 2 lb were eligible if they could be humanely, nonchemically restrained for phlebotomy. Age and minor health issues weren't exclusions. Dogs were excluded if trained personnel were concerned health would be compromised by phlebotomy. Blood samples were collected within 24 hours of entry. Four hundred and twenty-seven (40%) dogs had positive antibody test results for both viruses, 422 (40%) were positive for CPV, 37 (4%) were positive for CDV, and 170 (16%) were negative for both. Mapping revealed geographic patterns for dogs with negative antibody tests. This shelter admitted dogs with negative CPV and/or CDV antibody tests from defined community areas. Targeting vaccination efforts in communities to areas where dogs with negative antibody tests originate could be an effective wellness strategy.