Distribution of blood-group-related carbohydrate antigens on oral endothelial cells

Recent studies indicate that carbohydrate structures are involved in various endothelial functions such as inflammatory processes, adhesion of metastatic cells to endothelium and endothelial differentiation. In this paper we report the endothelial expression of various blood-group-related carbohydrate structures in normal oral mucosa using 15 different monoclonal antibodies reacting with type 1, 2 or 3 carbohydrate chains. Twenty biopsies, including normal oral mucosa, from secretor individuals comprised nine blood group O, nine A, one B and one AB. Endothelial staining was compared with epithelial staining in the same biopsies. Five blood-group-related carbohydrate antigens were detected on endothelial cells. The H type 2 antigen, which is the precursor of A, B and AB antigens, has previously been believed to be a universal marker for endothelial cells. All blood group O individuals (n = 9) showed strong H antigen staining in the endothelium of most vessels. However, of blood group A, B and AB individuals (n = 11), four showed heterogenous H antigen staining. In addition, we found that six out of ten blood group A or AB individuals, who expressed A or A and B antigens on spinous squamous cells and glandular epithelium, showed either heterogenous or no staining for these structures on their endothelial cells. It is concluded that there are differences between the biosynthesis of blood-group-related carbohydrate antigens in oral endothelium and epithelium.     

Relationship between ABO blood group and levels of Gal alpha,3Galactose-reactive human immunoglobulin G

BACKGROUND: The terminal Gal alpha1,3Galactose (alphaGal) determinant is present on all porcine glycoproteins and glycolipids, but is not expressed by human cells. Consequently human sera contain anti-alphaGal natural antibodies. The human blood group B antigen [Gal alpha1,3(Fuc1,2)Galactose] is differentiated from the alphaGal epitope by the presence of a fucosyl group. METHODS: To determine whether the expression of the B antigen has any effect on the level of alphaGal-reactive natural antibodies, equal numbers (n=12) of A, B, AB, and O serum samples were evaluated by ELISA and flow cytometry. RESULTS: A significant reduction in IgG alphaGal reactivity was observed with serum samples from B antigen-expressing donors (B, AB) relative to non-B antigen-expressing donors (A, O). CONCLUSIONS: These results are consistent with the possibility that anti-alphaGal antibodies in non-B antigen-expressing individuals include a subset that is reactive with the structurally related B antigen and that this subset is absent in B and AB individuals.     

Temporal and content variations as determinants of infants' visual control of verbal stimulations.

20 93–119 day old infants were presented with utterances varying in content or temporal structure that were contingent on fixation on a visual target. Treatment A consisted of utterances of equal duration and continually varying content. Treatment B consisted of utterances of slightly variable duration (temporal runs) and continually varying content. Treatment C included utterances organized in temporal runs and was composed of partial content variations (content runs). For Group AB, each A trial alternated with a B trial 4 times. For Group AC, each A trial alternated with a C trial 4 times. Half of the Ss in each group received Treatment A as their 1st trial; half of the Ss in Group AB received Treatment B; and half of the Ss in Group AC received Treatment C as their 1st trial. Group AB Ss showed a longer total fixation time than those of Group AC, with a more homogeneous distribution of number of fixations across treatments. Mean length of fixations was longer for Treatment A than B in Group AB, whereas Group AC showed a longer mean length of fixation for Treatment C relative to Treatment A. Those with Treatment B or C as their 1st trial looked more frequently at the target, and their decrease in looking time over trials showed a linear trend, whereas Ss with Treatment A at first displayed irregular decreases. These differences between groups and presentation orders suggest that 3-mo-old infants are sensitive to differences in linguistic material. (36 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Endocrine response and resistance in breast cancer: a role for the transcription factor Fos

The concentration of the tumor marker CA 19-9 is influenced by the patient's secretor status and Lewis genotype. The aim of this study was to establish novel reference intervals for CA 19-9 in serum based on secretor and Lewis genotypes, to investigate the biological variation of CA 19-9, and to evaluate the utility of Lewis and secretor genotyping on a group of individuals with serologically defined Lewis phenotypes. CA 19-9 was measured in serum of 500 healthy individuals. Secretor and Lewis genotypes were determined by sequencing and PCR-cleavage methods. Significant differences were found between subgroups with different Lewis and secretor genotypes. Genotype-based reference intervals for CA 19-9 are presented. The upper reference limit for all individuals was 28.7 kilounits/L; for secretors and nonsecretors, the upper reference limits were 12.4 and 61.2 kilounits/L, respectively. The analytical imprecision (CVA) was 9.8%, the within-subject variability (CVI) was 15.8%, and the between-subject variability (CVG) was 102.2%. Good agreement was found between Lewis and secretor genotyping and conventional blood grouping. Genotype-based reference intervals may be a way to increase the clinical utility of CA 19-9. On the basis of the calculation of a critical difference for sequential values (significant at P 相似文献   

N18-RE-105 cells: differentiation and activation of p53 in response to glutamate and adriamycin is blocked by SV40 large T antigen tsA58

A sodium dodecyl sulphate-agarose apolipoprotein(a) [apo(a)] phenotyping method was set up to attain accurate scanning densitometry of proteins. Serum samples from 99 healthy Spanish men were analysed and twenty-five different apo(a) isoforms (12 to 37 kringle 4 repeats) were detected. Double-band phenotypes accounted for 39.4% (n = 39) and three different patterns of protein expression were identified: pattern A (20.5% of double-band phenotyped samples) predominantly expressed the highest molecular weight isoform; pattern B (53.9%) mainly the lowest molecular weight isoform, and pattern AB (25.6%), expressed both isoforms equally. A significant linear association between expression pattern and lipoprotein(a) [Lp(a)] concentration > or = 0.30 g/l was observed. Single-band phenotyped samples (n = 60) were stratified according to apo(a) kringle 4 repeat categories and showed that 90% of isoforms < 20 K4 repeats had high Lp(a) concentrations (> or = 0.30 g/l), whereas isoforms with 20 to 24 or more than 24 kringle 4 repeats had Lp(a) concentrations > or = 0.30 g/l in 47% and 14%, respectively. A logistic regression model was fitted to test the association between apo(a) size, expression pattern and Lp(a) concentration. In this model, apo(a) isoform < 25 kringle 4 repeats was significantly associated with serum Lp(a) concentration > or = 0.30 g/l in both single and double-band phenotyped samples (odds ratio = 8.9, p < 0.001). In the latter, a differential expression pattern with respect to smaller size isoforms (pattern AB vs A) was significantly associated with Lp(a) concentration > or = 0.30 g/l (odds ratio = 17.97, P = 0.045). Heterogeneity in protein apo(a) size expressed according to kringle 4 repeat number could be categorized in heterozygous phenotypes as three patterns. When small-sized isoform was expressed (pattern B) or both isoforms were equally expressed (pattern AB), the probability of having Lp(a) > or = 0.30 g/l is higher.     

Collaborative problem-solving in telemedicine and evidence interpretation in a complex clinical case

The objective of this study was to evaluate the effect of different infection levels of Ostertagia ostertagi and Cooperia oncophora in a simulated 'first grazing season' on the resistance of calves to an artificial challenge infection. The infection levels were determined by the infection schedules and the chemoprophylaxis used. Thirty six 7-11-month old Holstein-Friesian bull calves were randomly divided into four groups. The animals of group B received an ivermectin sustained release bolus (ISRB) on day 0. The calves of group D were treated on days 0 and 56 with a subcutaneous injection of doramectin (0.2 mg kg(-1) BW). Group C was the untreated control group. The calves of group N were used as helminth-naive controls, while the animals of groups B, C and D were trickle infected for 24 weeks. The infection schedules were designed to simulate the expected infection pattern for each treatment group under set-stocked conditions in temperate climate areas. After the last infection, all animals were treated with oxfendazole. One week later, all animals received a challenge infection of 50,000 O. ostertagi L3 and 100,000 C. oncophora L3, spread over 10 consecutive days. During the primary infection period the faecal egg output and the serum pepsinogen and antibody levels reflected the different levels of host-parasite contact between the groups (group C > group D > group B > group N). After the challenge infection, faecal egg counts, total Ostertagia burden, size of the adult worms and abomasal globule leucocyte counts all indicated a positive relationship between the level of Ostertagia infection during the primary infection period and the level of acquired resistance. A reduction of host-parasite contact during the primary infection period, as a consequence of the infection schedule and the chemoprophylaxis used, resulted in a diminished level of resistance to the artificial challenge infection with O. ostertagi. Faecal cultures and small intestine worm counts indicated that all previously infected groups had acquired a high degree of resistance to the Cooperia challenge infection.     

Connection between the group factors of the blood systems ABO, MNSs, and rhesus and peculiarities of the vaccination process in children immunized against smallpox

The ahthors present new data on the character of the vaccine process in children associated with the characteristics of the blood group ABO, MNSs and Rh systems. The greater frequency of occurrence and more manifest reactions were noted in children with blood groups A, B, AB, M and Rho (D) - in comparison with those having blood groups O, Rho (D) +, MN and N. There was a significant prevalence of chromosomal aberrations in the primarily immunized children with blood groups A in comparison with groups O, B and AB. The data obtained pointed to the negative effect of the mimi-rating antigens of the smallpox virus on the immunogenesis in smallpox. Search for methods of releasing the vaccine of these antigens is necessary for reduction of the reactogenic properties and increase of immunogenecity of the smallpox vaccines.     

The platelet factor 3 assay and circulating immune complexes as studied on non-thrombocytopenic patients with systemic lupus erythematosus

Sera from 21 patients with systemic lupus erythematosus (SLE) were tested with a platelet factor 3 (PF3) assay. A control serum (pooled blood group AB serum) was always run in parallel with the test sera. The test and control sera were run in duplicate and for each patient the mean recalcification time was used for the calculation of the test serum: AB serum ratio. Concomitantly, the patients' serum concentrations of circulating immune complexes (CIC) were measured by using the Raji cell radioimmunoassay. 20 healthy hospital employees served as controls. In the latter subjects the mean test serum: AB serum ratio was 0.99 (range 0.92-1.09), their CIC concentrations being less than or equal to 16 micrograms/ml. 7 of the SLE patients had CIC values less than or equal to 16 micrograms/ml, and their test serum: AB serum ratios ranged 0.95-1.09. All the remaining SLE patients had elevated values for CIC. In the total material of SLE there was a highly significant (r = -0.87; P less than 0.001) negative correlation between the test serum: AB serum ratios and the values for CIC. It is widely held that the so-called PF3 immunoinjury test detects circulating antiplatelet antibodies. The present results, however, strongly suggest that the assay rather or also detects CIC which like antiplatelet antibodies may damage platelets as we and others have shown in prior publications.     

Oral Candida carriage and blood group antigen secretor status

Oral Candida carriage and blood group antigen secretor status were examined in 92 healthy, young volunteers. Candida was isolated from 61 of 92 saliva samples (66% Candida carriage). In 76% of cases this was Candida albicans. Oral Candida carriage was found to be significantly associated with non-secretion of blood group antigens (P < 0.05). However, the numbers of Candida were higher in the saliva of secretors than of non-secretors (P < 0.01). A higher percentage of Candida carriage was observed in individuals with blood group O. Thus, the finding of higher carrier frequency in the non-secretors and in blood group O subjects is confirmed.     

Attenuation of neutrophil and endothelial activation by intravenous morphine in patients with acute myocardial infarction

To investigate the effects of morphine on neutrophil and endothelial activation, we measured serum levels of intercellular adhesion molecule-1 (ICAM-1), L-selectin, and neutrophil endopeptidase 24.11 (NEP) in 38 patients with acute myocardial infarction (group 1) and 16 control subjects (group 2). In group 1, all the patients underwent blood sampling at initial presentation and 10 minutes later. Twenty of them had 3 mg of morphine administered intravenously immediately after the first sampling (group 1A) and the other 18 after a second sampling (group 1B). The serum levels of ICAM-1 and L-selectin were both significantly higher in groups 1A and 1B than in group 2. In group 1A, the ICAM-1 decreased significantly at second blood samplings (310 +/- 28 vs 368 +/- 30 ng/ml; p <0.001), whereas in group 1B there was no significant change in ICAM-1 (357 +/- 33 vs 359 +/- 26 ng/ml; p = NS). In group 1A, the L-selectin decreased significantly at second blood samplings (2.3 +/- 1.2 mg/L, p <0.001 vs baseline), whereas in group 1B there was no significant change in L-selectin (3.9 +/- 1.0 mg/L, p = NS vs baseline). There was no significant difference in baseline NEP activities between groups 1A and 1B (4.89 +/- 1.22 vs 5.14 +/- 1.57 nmol/mg protein; p = NS). However, the NEP activities at second blood samplings decreased significantly in group 1A (9.88 +/- 1.86 nmol/mg protein, p <0.001 vs baseline), whereas no significant changes were observed in group 1B (5.09 +/- 1.62 nmol/mg protein, p = NS vs baseline). In conclusion, morphine increased NEP activities and thus attenuated shedding of L-selectin and ICAM-1.     

Creatine kinase isoenzymes in serum from cord blood and the blood of healthy full-term infants during the first three postnatal days

Isoenzymes of creatine kinase (ATP:creatine phosphotransferase; EC 2.7.3.2; CK) were measured by electrophoresis in serum from cord blood and skin-puncture blood taken from 45 healthy full-term infants during the first three postnatal days. Mean total CK activities (in U/L at 30 degrees C) were 185 in cord samples, 536 in samples taken between 5--8 h postnatally, 494 between 24--33 h, and 288 in the 72-100 h samples. Values for all three isoenzymes increased to a peak over this period, with the highest values generally being found in the samples taken 5--33 h after birth; the subsequent decline was most rapid for CK-BB. Serum CK isoenzymes in cord samples and those taken at 72--100 h in the 11 babies delivered by cesarian section did not differ significantly from those of babies delivered vaginally. However the postnatal increases in total CK, CK-MM, and CK-MB (but not in CK-BB) were significantly greater in those patients born by vaginal delivery. The reasons for the increases in CK isoenzymes after birth are not clear, but our results and reported studies on the ontogeny of CK suggest that CK-MB cannot be regarded as a "cardiac-specific" isoenzyme in the neonatal period.     

The clinical utility of asbestos body counts in bronchoalveolar lavage fluid

To assess the clinical utility of measuring the number of asbestos bodies (AB) present in bronchoalveolar lavage fluid (BALF), we counted the number of AB in BALF from 119 subjects using light microscopy. The results were analyzed according to occupational histories, radiological findings of asbestos-induced lung and pleural changes, and asbestos-related diseases. The 94 subjects in group 1 had a history of dust exposure, whereas group 2 subjects (n = 25) had no dust exposure. Group 1 was subdivided into subjects with obvious exposure to asbestos (group 1A, n = 61), and subjects with no known exposure to asbestos (group 1B, n = 33). The distribution of AB counts per ml of BALF (means +/- SEM) differed significantly between groups 1 and 2 (38.8 +/- 17.4 vs 0.06 +/- 0.04, p < 0.0001). The AB counts were significantly different between groups 1A and 1B (57.9 +/- 26.6 vs 3.4 +/- 1.2, p = 0.01). Subject, exposed to dust who had radiological evidence of pleural thickening had significantly higher AB counts than subjects in whom pleural thickening was absent (66.0 +/- 31.1 vs 5.1 +/- 4.2, p = 0.03). In group 1, the BALF was positive for AB in 7 of 14 patients with pulmonary fibrosis, 4 of 5 patients with lung cancer, all 6 patients with malignant mesothelioma, and all 4 patients with benign asbestos pleural effusion. We conclude that AB counts in BALF are useful for evaluating both the history of asbestos exposure in a population exposed to dust, as well as patients having asbestos-related diseases.     

The activity of acid phosphatase and its isoenzymes in patients with food poisonings

Changes in the activity of acid phosphatase (AP) and its isoenzymes (tartrate-insensitive AP and formalin-insensitive AP) were investigated in patients with food poisoning in the course of the disease. The activity of AP and its isoenzymes in the serum started to grow in early convalescence and reached maximum in late convalescence. Total activity of AP in food toxic infections consists primarily of the activity of its platelet fraction. AP activity may serve as an additional criterion to predict vascular platelet involvement of hemostasis.     

Timing of mating and ovarian response in llamas (Lama glama) treated with pFSH

The effect of the timing of mating on ovarian response in llamas was evaluated using 20 adult llamas weighing 90-120 kg which had been in oestrus for 5 days and were treated with 20 mg pFSH every 12 h for the following 5 days (total dose: 200 mg of FSH-NIH-P1). They were randomly allocated to Group A (N = 10) and mated immediately at the end of pFSH treatment or to Group B (n = 10) and mated 36 h after the end of pFSH treatment. Llamas of both groups were given hCG (750 iu, i.m.) immediately after mating. A second mating was allowed 12 h later. Ova and embryos were recovered by non-surgical uterine flushing 7 days after the first mating. Ovarian response was immediately evaluated afterwards via laparoscopy. The mean ovulation rate of 4.5 corpora lutea for Group A was significantly lower (P < 0.01) than the mean of 13.8 observed for Group B. The total ovarian response (number of corpora lutea + follicles > 10 mm) was also significantly higher (P < 0.01) in Group B than in Group A. Twenty-seven ova were recovered in each group, corresponding to 60% and 20% (P < 0.01) of the corpora lutea observed in Groups A and B, respectively; however, no significant difference (P > 0.05) in fertilisation rate was observed. The results show that pFSH induces superovulation in llamas treated during oestrus and that a 36-h interval between the end of FSH treatment and mating increases ovulation rate and the total ovarian response but does not affect the number of ova/embryos recovered.     

Effects of intraoperative blood transfusion on postoperative complications and survival after orthotopic liver transplantation

BACKGROUND/AIMS: Massive blood transfusion related to the coagulation disorders occurring during the anhepatic and reperfusion phases, remains a serious problem during orthotopic liver transplantation. To analyze the influence of intraoperative blood transfusion on postoperative complications, and survival and to identify the preoperative variables associated with greater intraoperative bleeding, 100 orthotopic liver transplantations, carried out on adults, were reviewed in our center. METHODOLOGY: Patients were grouped into three categories according to intraoperative blood volume transfused; group A, 1.5 or less blood volumes transfused; group B, > 1.5 and < 3 volumes used and group C, 3 or more volumes given. RESULTS: Group C patients had a higher incidence of upper abdominal surgery (p < 0.01 between groups C and A. and p<0.05 between groups C and B); higher values of postoperative total bilirubin and SGOT, and lower prothrombin activity. Acute rejection and steroid-resistant episodes per patient occurred less commonly (p <0.01 between groups C and A) and so did chronic rejection (p <0.05 between groups C and B). Higher infection rate, and gastrointestinal and intraabdominal complication rates were also noticed in groups C and B (p < 0.01 and p < 0.05 respectively). Patient survival rates were lower in group C (p < 0.05 between groups C and A). CONCLUSIONS: It was concluded that previous upper abdominal surgery was the only preoperative factor associated with massive blood transfusion. Poor graft function during the first days after transplant, higher incidence of infections, higher incidence of gastrointestinal and intraabdominal complications, and lower rejection episodes and survival for patients receiving intraoperatively large amounts of blood can be expected.     

Serum transferrin receptor concentration is not indicative of erythropoietic activity in chronic hemodialysis patients with poor response to recombinant human erythropoietin

BACKGROUND: Serum transferrin receptor (sTfR) is a transmembrane glycoprotein derived from erythroid precursors in the bone marrow. Its concentration provides a quantitative measure of total erythropoietic activity and an indication of functional iron deficiency. This study was conducted to investigate whether sTfR is a useful index of erythropoietic activity in chronic hemodialysis patients with poor response to maintenance recombinant human erythropoietin (rHuEPO) therapy. METHODS: Using an enzyme-linked immunosorbent assay, sTfR concentration was measured in 67 uremic patients who had been on hemodialysis for a mean of 42 months (3-242 months). rHuEPO was administered three times a week to keep the hematocrit above 30%. Hemoglobin, red blood cell indices, serum ferritin, serum total iron binding capacity and unsaturated iron binding capacity were determined. Of the 67 patients, 35 who responded favorably to rHuEPO with hematocrits above 30% were categorized as Group I and 32 who did not attain the target hematocrit were categorized as Group II. As a control group, 31 healthy subjects were also investigated. RESULTS: The serum iron, ferritin, transferrin iron saturation, dialysis efficiency and nutritional state were not different between groups of hemodialysis patients. The mean sTfR concentration was 2.1 +/- 0.6 micrograms/ml (range, 1.15-3.53 micrograms/ml) in Group I patients, compared with 1.9 +/- 0.9 micrograms/ml (range, 1.03-2.65 micrograms/ml) in Group II. The difference was not significant. In addition, the mean sTfR concentration of 1.8 +/- 0.4 micrograms/ml (range, 0.86-2.76 micrograms/ml) in the healthy controls was not significantly different from Groups I and II. CONCLUSIONS: sTfR concentration cannot be used to distinguish good from poor rHuEPO responders among chronic hemodialysis patients who have elevated serum ferritin (> 300 micrograms/l) and transferrin iron saturation (> 25%) during the course of maintenance rHuEPO therapy.     

Addition of lamivudine to the drug regimen in patients with advanced HIV disease on nucleoside therapy

As preoperative elevated serum levels of carcinoembryonic antigen (CEA) and CA19.9 are markers for bad prognosis in colorectal cancer patients, it is important to decide whether preoperative total colonoscopy would make a significant change in their serum levels. CEA and CA 19.9 were evaluated in three groups of patients before and after colonoscopy. The groups comprised the following: Group A, 20 patients with colorectal cancer; Group B, 17 patients with colorectal polyp of > or = 1-cm diameter; Group C, 16 patients with no colorectal pathology. CEA serum levels were found to be significantly lower after colonoscopy in all groups. CA19.9 was found to be significantly lower after colonoscopy only in Group B; it did not reach significance in Group A and was found not to be significantly higher in Group C.     

The enzymatic sulfation of glycoprotein carbohydrate units: blood group T-hapten specific and two other distinct Gal:3-O-sulfotransferases as evident from specificities and kinetics and the influence of sulfate and fucose residues occurring in the carbohydrate chain on C-3 sulfation of terminal Gal

Enzymatic 3-O-sulfation of terminal beta-Gal residues was investigated by screening sulfotransferase activity present in 37 human tissue specimens toward the following synthesized acceptor moieties: Galbeta1,3GalNAc alpha-O-Al, Galbeta1,4GlcNAcbeta-O-Al, Galbeta1,3GlcNAcbeta-O-Al, and mucin-type Galbeta1,4GlcNAcbeta1,6(Galbeta1,3)GalNAc alpha-O-Bn structures containing a C-3 methyl substituent on either Gal. Two distinct types of Gal: 3-O-sulfotransferases were revealed. One (Group A) was specific for the Galbeta1, 3GalNAc alpha- linkage and the other (Group B) was directed toward the Galbeta1,4GlcNAc branch beta1,6 linked to the blood group T hapten. Enzyme activities found in breast tissues were unique in showing a strict specificity for the T-hapten. Galbeta-O-allyl or benzyl did not serve as acceptors for Group A but were very active with Group B. An examination of activity present in six human sera revealed a specificity of the serum enzyme toward beta1,3 linked Gal, particularly, the T-hapten without beta1,6 branching. Group A was highly active toward T-hapten/acrylamide copolymer, anti-freeze glycoprotein, and fetuin O-glycosidic asialo glycopeptide; less active toward fetuin triantennary asialo glycopeptide; and least active toward bovine IgG diantennary glycopeptide. Group B was moderately and highly active, respectively, with the latter two glycopeptides noted and least active with the first two. Competition experiments performed with Galbeta1,3GalNAc alpha-O-Al and Galbeta1,4GlcNAcbeta1,6(Galbeta1,3)GalNAc alpha-O-Bn having a C-3 substituent (methyl or sulfate) on either Gal reinforced earlier findings on the specificity characteristics of Group A and Group B. Group A displayed a wider range of optimal activity (pH 6.0-7.4), whereas Group B possessed a peak of activity at pH 7.2. Mg2+ stimulated Group A 55% and Group B 150%, whereas Mn+2 stimulated Group B 130% but inhibited Group A 75%. Ca2+ stimulated Group B 100% but inhibited Group A 35%. Group A and Group B enzymes appeared to be of the same molecular size (<100,000 Da) as observed by Sephacryl S-100 HR column chromatography. The following effects upon Gal: 3-O-sulfotransferase activities by fucose, sulfate, and other substituents on the carbohydrate chains were noted. (1) A methyl or GlcNAc substituent on C-6 of GalNAc diminished the ability of Galbeta1,3GalNAc alpha-O-Al to act as an acceptor for Group A. (2) An alpha1,3-fucosyl residue on the beta1,6 branch in the mucin core structure did not affect the activity of Group A toward Gal linked beta1,3 to GalNAc alpha-. (3) Lewis x and Lewis a terminals did not serve as acceptors for either Group A or B enzymes. (4) Elimination of Group B activity on Gal in the beta1,6 branch owing to the presence of a 3-fucosyl or 6-sulfo group on GlcNAc did not hinder any action toward Gal linked beta1,3 to GalNAc alpha. (5) Group A activity on Gal linked beta1,3 to GalNAc remained unaffected by 3'-sulfation of the beta1,6 branch. The reverse was true for Group B. (6) The acceptor activity of the T-hapten was increased somewhat upon C-6 sulfation of GalNAc, whereas, C-6 sialylation resulted in an 85% loss of activity. (7) A novel finding was that Galbeta1,4GlcNAcbeta-O-Al and Galbeta1,3GlcNAcbeta-O-Al, upon C-6 sulfation of the GlcNAc moiety, became 100% inactive and 5- to 7-fold active, respectively, in their ability to serve as acceptors for Group B.     

Retroviral recombination is nonrandom and sequence dependent

The ABO blood group is the most clinically important human alloantigen system in transfusion medicine. The system involves three antigens A, B and H. H antigen is converted to either A or B by the activity of alpha1-->3-N-acetyl-galactosaminyl transferase (A transferase) or alpha1-->3 galactosyl transferase (B transferase). The O phenotype is the result of an inactive glycosyltransferase, which is unable to glycosylate the H antigen. The immunological properties of the ABO system were identified at the turn of the century; however, the genetic basis of the ABO system has only recently been characterized. This has enabled the development of a number of molecular ABO typing methods. Described here is a two-reaction multiplex allele-specific PCR (ASPCR) genotyping assay for the A1, A2, B, O1 and O2 subtypes. 11 different allele-specific oligonucleotide primers were selected to detect the presence or absence of the O1 associated G--> (-) deletion at base 261, the O2 associated G --> A substitution at base 802, the B associated G --> A substitution at base 803, and finally the A2 associated C --> (-) deletion at base 1059. A total of 122 peripheral blood samples were genotyped and serologically forward and reverse typed. A concordance rate of 98.4% (120/122 samples) was observed between the actual genotype and the serologically-based predicted genotype. These results indicate that this assay provides a rapid, accurate, and simple method for A(1,2)BO(1,2) genotyping that serves as a useful supplement to standard serological ABO typing.