The Rh Antigen Dw (Wiel)

Evidence is brought forward confirming that the antigen "Wiel" ( Transfusion 2: 150, 1962) is part of the D segment of the Rh system; is rare in Whites (none in 13,000) but not uncommon in Negroes (9 positive in 253). Its name is changed to D^w, Rh(23) or rh^wo, the common genes designated *** D ^we or R ^w_o, CD ^w e or R ^wo₁ and cD ^w E or R ^wo₂, and a table of phenotypes and genotypes given. When D^w is not partnered with D it reacts as a D^u; its specific nature is recognized by reaction with anti-D^w.     

Gu, a Variant of G

G^u, analogous to D^u and E^u, is a weak variant of G appearing in a haplotype lacking C, D, and E but having e^s.
In a preliminary survey, the red blood cells ot three of 186 Negro blood donors found negative when tested for C, D (incuding D^u), and E were shown to be G^u-positive when tested with anti-CD by the antiglobulin technic.
Fourteen additional examples from unrelated persons and five members of a family have been investigated in this study. All G^u-positive individuals tested are VS-positive, but V-negative, and all are Negro. Although G cells show greater antibody uptake when used to absorb anti-CD, G^u cells elute anti-G in substantially greater amounts than do G cells. Comparative studies demonstrate similarity of specificity but a difference of avidity, which could be due to the influence of e^s(VS) in cis position.
G^u-positive bloods have been shown to stimulate the production of anti-G in Rh-negative recipients. The test for G^u can be incorporated in the test for D^u by substituting anti-CD or anti-CDE for anti-D serum.     

The Expected "Bombay" Groups OhA1 and OhA2

An American family of English extraction is reported in which two Oh ("Bombay") members have transmitted A ₂ genes to their children thus demonstrating that the expression of the gene A ₂, like that of the gene B , can be suppressed in this phenotype. Another American family, of French extraction, shows with a high degree of probability that the expression of the gene A ₁ can be similarly suppressed.     

Levcromakalim decreases vascular tone, cytoplasmic Ca2+ and Ca2+ sensitivity in canine basilar artery

Summary— The involvement of large conductance Ca²⁺-activated K⁺ channels (BK) and ATP-sensitive K⁺ (K_ATP) channels in the regulation of canine basilar arterial tone was estimated in the presence of the agonist and blockers of these channels, by simultaneously measuring the changes in intracellular Ca²⁺ concentration ([Ca²⁺]_i) with the fura-2 microfluorimetric method. In the resting condition, levcromakalim reduced [Ca²⁺]_i and vascular tone. Levcromakalim suppressed the serotonin-induced increases in [Ca²⁺]_i and force of contraction, the maximum effects of which were much greater than those of nicardipine. The inhibitory effects of levcromakalim were blocked by glibenclamide but not by tetraethylammonium (TEA) or iberiotoxin (IbTX). In the presence of levcromakalim, the curve relating [Ca²⁺]_i with force in the presence of serotonin at different extracellular Ca²⁺ concentration ([Ca²⁺]_o) was shifted down- and right-ward compared with that in the absence of levcromakalim, suggesting that levcromakalim may reduce the Ca²⁺-sensitivity of the contractile proteins. Thus, levcromakalim may be a good candidate to suppress delayed cerebral vasospasm after subarachnoid hemorrhage.     

Cluster Headache: The Peripheral Chemosensitivity as Indicated by the Single-Breath CO2 Test

SYNOPSIS
A single-breath CO₂ test was carried out in cluster headache patients both during bout and remission, and in matchedhealthy individuals (n = 10 for each group) to assess peripheral chemosensitivity. The test subjects inhaled one tidal breath of13% CO₂ in air. The response was expressed as the maximal increase in inspiratory minute ventilation (V_I) within 20 secondsfrom the exposure to CO₂, divided by the increase in end-tidal PCO₂ (P_ETCO₂) (the difference in PCO₂ between the testbreath and the preceding control breaths): DV_I/DP_ETCO₂.
Under the initial resting condition, cluster headache patients within the bout showed a slight hyperventilation in that therewas a significantly reduced P_ETCO₂ (P < 0.05, Student's paired t-test), and during remission, higher V_I, and a lower P_ETCO₂ (P < 0.05, Wilcoxon signed rank test), in comparison with the controls. There was no statistically significantdifference as regards the peripheral chemosensitivity between cluster headache and control groups. These results indicatethat cluster headache patients have an intact and properly-functioning carotid body.     

The Frequency and Nature of Blood Group A3

A special survey of 20,826 random blood donor specimens collected in Ontario, Canada yielded one A₃ blood while a review of blood grouping worksheets of 158,000 individuals in this area also yielded one A₃ blood. These frequencies are much lower than the frequency found in Denmark around 1940 by Gammelgaard, 44 per 10⁵, perhaps due to the present availability of high titer immune anti-A. Elution studies on these two A₃ bloods show that both the agglutination-positive and the agglutination-negative cells absorb anti-A, indicating that A₃ is not always an A₂ + O mixture as has been suggested. Fluorescent antibody studies revealed a marked cell-to-cell variability in fluorescence and, therefore, presumably, cell A antigen content. This finding confirms Gammelgaard's earlier report. This variability, together with a threshold value of A antigen required for agglutination, could explain the characteristic appearance of A₃: agglutinates and free cells.     

Erythrocyte Na+–H+ exchanger kinetics and Na+–Li+ countertransport activity in essential hypertensive patients

The authors measured Na⁺–H⁺ exchanger kinetics together with Na⁺–Li⁺ countertransport V _max in the erythrocytes of 21 subjects with essential hypertension and 16 normotensive control subjects. Na⁺–H⁺ exchanger V _max appeared to be increased in patients with essential hypertension, while the Na⁺–H⁺ exchanger affinity for intracellular proton sites ( K _50%) proved to be unchanged and the index of cooperativity among intracellular proton binding sites as measured by Hill's coefficient (Hill's n ) decreased as compared with normotensive control subjects. Na⁺–Li⁺ countertransport V _max appeared to be higher in patients with essential hypertension than in control subjects. The authors were unable to find any correlations between Na⁺–H⁺ exchanger kinetic parameters and metabolic variables such as parameters of insulin resistance and plasma lipids. On the basis of the data obtained, erythrocyte Na⁺–H⁺ exchanger activity was found to be abnormal in two kinetic variables in essential hypertensive patients and showed no simple linear correlations with the main variables of glucose metabolism, plasma lipids, renin or aldosterone.     

Reaction of I131 Anti-Rho(D) with Enzyme Treated Red Cells

The effect of proteolytic enzymes (papain, trypsin, ficin and bromelin) on Rh_o(D) positive and negative red cells was studied with I¹³¹ anti-Rh_o(D). Enzymatic pretreatment of red cells results in almost a two-fold increase in the amount of I¹³¹ antiRh_o(D) bound to these cells. The "enzyme exposed Rh_o(D)" antigen by some criteria (stability to hemolysis, absence of an increase in negative cells and studies on the supernatant solutions) appears to have the same specificity as the Rh_o(D) antigen on the untreated cell. The ability of proteolytic enzymes to produce this effect on Rh_o(D) positive red cells does not correlate directly with the ability of these enzymes to digest casein, although the effect appears to be associated with the proteolytic activity of these enzymes. The amount of increase in uptake of I¹³¹ anti-Rh_o(D) induced by enzymes is directly proportional to the quantity of antibody bound by the untreated cell, irrespective of the Rh phenotype or zygosity of the red cell.     

Erythrocyte Na+-H+ exchanger and Na+-Li+ countertransport activity in primary aldosteronism

Abstract. Several authors have described increased Na-H exchanger activity in essential hypertension but no data are available in secondary forms of hypertension such as primary aldosteronism. We measured Na-H exchanger kinetics together with Na-Li countertransport V _max in the erythrocytes of eight patients with primary aldosteronism and in 15 normotensive control subjects. Plasma aldosterone, plasma renin and plasma potassium were also evaluated. Na-H exchanger V _max appear to be increased in patients with primary aldosteronism and Hill's n , an index of co-operativity amongst intracellular proton binding sites, was significantly lower in patients than in controls. No statistically significant differences were found between affinity for intracellular protons (K50%) and for Na-Li countertransport V _max between the two groups studied. We were unable to find any correlations between Na-H exchanger V _max and Na-Li countertransport V _max in the two groups considered as a whole. From the present data Na-H exchanger overactivity would not appear to be a specific feature of essential hypertension but seems to be characteristic in patients with primary aldosteronism.     

Heterogeneity of the blood group Ax allele: genetic recombination of common alleles can result in the Ax phenotype

The A_x phenotype is an important subgroup of the ABO blood group system. Its inheritance does not always follow Mendelian rules and recent studies suggested that different alleles can result in this phenotype. This suggestion has been explored by cloning and sequencing exons 6 and 7 of the ABO gene and the intervening intron from members of six unrelated families expressing the A_x phenotype.
Two families showed the previously described T646A 'A_x' mutation as the only deviation from the consensus A¹ allele. In two other families the A_x phenotype was inherited as two different recombinational gene products. Combination of exon 6 derived from A or B/O² alleles with exon 7 from the O^1v allele created two novel alleles that have four O^1v -characteristic nucleotide substitutions in exon 7, including T646A. Sequencing and analysis of polymorphisms in intron 6 defined the crossing-over zones of these hybrid alleles. Southern blot confirmed the hybrid formation by detecting ABO-related polymorphisms ≈ 1.35 kb downstream from the ABO reading frame.
The remaining two families expressed the A_x phenotype via an allele having A² -specific mutations. Thus, a heterogeneous molecular background leads to the serologically defined A_x phenotype and may well explain the different modes of inheritance observed.     

Gonzales (Goa), A New Blood Group Character

A new blood group character, Gonzales (Go^a), has been described. The antibody was found during the investigation of a case of erythroblastosis fetalis. Go^a occurs almost exclusively in individuals of Negro parentage. Go^a has been shown to segregate independently from the ABO, Rh, MNS, Kell, Duffy, Kidd and Xg blood group systems and may represent an entirely new blood group system.     

15-deoxy-Δ12,14 prostaglandin J2-induced heme oxygenase-1 in megakaryocytes regulates thrombopoiesis

Summary.  Background:  Platelet production is an intricate process that is poorly understood. Recently, we demonstrated that the natural peroxisome proliferator-activated receptor gamma (PPARγ) ligand, 15-deoxy-Δ^12,14 prostaglandin J₂ (15d-PGJ₂), augments platelet numbers by increasing platelet release from megakaryocytes through the induction of reactive oxygen species (ROS). 15d-PGJ₂ can exert effects independent of PPARγ, such as increasing oxidative stress. Heme oxygenase-1 (HO-1) is a potent antioxidant and may influence platelet production. Objectives:  To further investigate the influence of 15d-PGJ₂ on megakaryocytes and to understand whether HO-1 plays a role in platelet production. Methods:  Meg-01 cells (a primary megakaryoblastic cell line) and primary human megakaryocytes derived from cord blood were used to examine the effects of 15d-PGJ₂ on HO-1 expression in megakaryocytes and their daughter platelets. The role of HO-1 activity in thrombopoiesis was studied using established in vitro models of platelet production. Results and conclusions:  15d-PGJ₂ potently induced HO-1 protein expression in Meg-01 cells and primary human megakaryocytes. The platelets produced from these megakaryocytes also expressed elevated levels of HO-1. 15d-PGJ₂-induced HO-1 was independent of PPARγ, but could be replicated using other electrophilic prostaglandins, suggesting that the electrophilic properties of 15d-PGJ₂ were important for HO-1 induction. Interestingly, inhibiting HO-1 activity enhanced ROS generation and augmented 15d-PGJ₂-induced platelet production, which could be attenuated by antioxidants. These new data reveal that HO-1 negatively regulates thrombopoiesis by inhibiting ROS.     

Radioimmunoassay of Prostaglandins Fα, E1 and E2 in Human Plasma

Abstract. Antibodies against prostaglandins (PG)F₂α, E₁ and E₂ were obtained in rabbits immunized with respectively PG F₂α, PG E₁ and PG E₂ conjugated to bovine serum albumin by carbodiimide. A radioimmunoassay capable of measuring 7 pg of PG Fα, 2 pg of PG E₂ and 14 pg of PG Ej in human peripheral plasma is described. Plasma samples (pH 3, citric acid) are extracted with cyclohexane: ethyl acetate, 1:1 and then chromatographed on silicic acid columns to separate the prostaglandins into three fractions: fraction I, PG A, PG B and some unknown immunoraactive compounds; fraction II, PG E and fraction III PG Fα. The recovery is 80 %± 6. 2. Mean plasma levels iu adults of PG Fa and PG E, expressed in pg/ml: -PG Fα 12 ± 2. 8 (n = 25 men), 8 ± 2. 3 (n = 18 women, follicular phase), 7 ± 1. 4 (n = 18 women, luteal phase). -PG E₁ 40. 5 + 7. 6 (n = 13 men), 38 + 17. 1 (n = 10 women). -PG E₂ 4. 5 ± 1 (n = 12 adult subjects).
The major characteristics of the method described herein are the following: - a large volume of plasma has to be processed (10 ml or more for PG Fa and PG E₁, 5 ml or more for PG E₂). - a chromatographic step is necessary to separate the different prostaglandins which makes it possible to circumvent problems of immunological cross reactivity and interference with unknown immunoreactive compounds. - great care has been taken in collection of blood samples, especially to insure complete removal of blood cells namely platelets.     

Immunization to Rho(D) Observed in Pregnancy of a Woman with Type rhG(G)

A Negro woman was tested during her third pregnancy and found to have type rh^G(G). When the patient was re-tested during the sixth month of her fourth pregnancy, she was found to have a weak antibody of questionable identity. During the last two months of the pregnancy, the titer of the antibody rose sharply and it was established to be specific for Rh_o(D). The infant, delivered by cesarean section shortly before term, had evidence of mild hemolytic disease; it recovered without transfusion therapy. Since this indicates that isoimmunization to Rh_o can occur in a person of type rh^G, such persons should receive only Rh_o-negative blood for transfusion. They should be regarded as Rh-negative for prenatal purposes, but it might be considered preferable not to use them as blood donors for Rh-negative recipients.     

The Phenotype Rhod: Study of Another Family

A case is described in which an Rh_o-positive Negro woman suffered a transfusion reaction. Her serum was found to contain anti-rh", anti-Fy^a, anti-Jk^b and an antibody resembling anti-Rh_o. A family investigation showed that the propositus and two of her five children belong to the pheno- type Rh_o^d. This evidence gives further support to the theory that the agglutinogen Rh_o^d is determined by a corresponding allelic gene R ^od.     

Rapid detection of anti-Lub with recombinant Lub protein and the particle gel immunoassay

BACKGROUND: Until now, it was not possible to identify antibodies to red blood cells (RBCs) except with pretyped RBCs. Here, a novel method with particles coated with recombinant Lu^b protein for detection of anti-Lu^b is described.
STUDY DESIGN AND METHODS: Prokaryotic recombinant Lu^b proteins were generated and coupled onto superparamagnetic particles coated with streptavidin. The coated particles were tested in the presence of different serum and plasma samples (13 anti-Lu^b, 6 anti-Lu^a, 20 other antibodies, and 35 serum samples from blood donors) with the particle gel immunoassay (ID-PaGIA).
RESULTS: Lu^b-coated particles reacted with all 13 samples containing anti-Lu^b, but not with any samples lacking anti-Lu^b. In addition, the anti-Lu^b titers were higher with Lu^b-coated particles than with Lu(a–b+) RBCs in almost all cases.
CONCLUSION: Recombinant blood group proteins may be able to dispense with the need for RBCs for identification of certain RBC alloantibodies.     

The Rho Variant-Du

A simplified test for the D^u factor employing a reagent containing 25 per cent serum albumin, the "stick" technic to introduce cells and forceful cen-trifugation has been given an extensive trial in a routine blood bank operation. A routine preliminary test with anti-D gave 5,051 negative reactions among 26,753 bloods tested. The D^u tube test was then performed on the former with an anti-CDE reagent in parallel with the indirect antiglobulin test done with anti-D. All bloods positive by one or both tests were tested further for D antigens by an anti-D elution technic; they were also tested for Rh-Hr factors.
Among the 126 bloods positive by elution for the D^ufactor, 122 and 126 were positive respectively by the antiglobulin and the D^u tube tests. The two tests were in agreement on all eight of the type ccD^uee bloods found in the study. The D^utube test, as done with anti-CDE, gave no false negative reactions. It is, thus, concluded that bloods which are negative with this test will be type ccddee and can be labeled "Rh negative tested for D^u. Serological factors which might account for sensitivity of the D^u tube test's being the equal of the antiglobulin test are considered, as are the probabilities of the existence of D variants so weak that they could not be detected by either test.     

Imaging of Ca2+-induced cytoplasmic Ca2+ responses in normal and pathological parathyroid cells

Ca²⁺-induced changes in the cytoplasmic Ca²⁺ concentration ([Ca²⁺]_i) were studied in bovine and normal and pathological human parathyroid cells using digital image analysis of fura-2-loaded cells. When raising external Ca²⁺ from 0.5 to 3.0 mmol L⁻¹, about 95% of all cells reacted rapidly and simultaneously with sustained elevation of [Ca²⁺]_i. In approximately two out of three bovine parathyroid cells, normal human cells and cells from most patients with hyperparathyroidism (HPT) the sustained phase was preceded by an overshooting [Ca²⁺]_i transient. The proportion of cells with such a transient was decreased in cells from severe cases of uraemic parathyroid hyperplasia only. However, pathological human cells from adenomas and normal-sized glands associated with adenomas, as well as cells from primary and uraemic hyperplasias, had lower peak and sustained levels than normal human and bovine cells. The results indicate that both normal and pathological parathyroid cells exhibit heterogeneity in their [Ca²⁺]_i responses to elevation of external Ca²⁺. The Ca²⁺-induced [Ca²⁺]_i transients and the sustained elevations are attenuated in pathological human parathyroid cells. However, the presence of the overshooting transient represents physiological variability rather than being a consequence of the pathophysiology associated with HPT.     

Blood group A antigen expression in platelets is prominently associated with glycoprotein Ib and IIb. Evidence for an A1/A2 difference

Blood group ABH antigens are associated with platelets as intrinsic determinants and extrinsically adsorbed antigens, and exist both on glycosphingolipids and on glycoproteins (GPs). We now provide direct evidence that the blood group ABH antigens are prominently associated with platelet GPIb and GPIIb. By immunoprecipitation, a murine monoclonal anti-A antibody precipitated surface-biotin-labelled blood group A₁ platelet membrane proteins with electrophoretic characteristics identical to those of GPIb/IX and GPIIb/IIIa. By immunoblotting of SDS-PAGE separated blood group A₁ platelet proteins the monoclonal anti-A antibody bound to proteins with electrophoretic characteristics identical to those of GPIb and GPIIb. When immunoaffinity purified GPIb/IX and GPIIb/IIIa, derived from blood group O, A₁ and A₂ platelets, were employed for immunoblotting, GPIb and GPIIb only from A₁ platelets bound the monoclonal anti-A antibody. By ELISA, wherein monoclonal antibodies specific for GPIb (AP1) and the GPIIb/IIIa complex (AP2) were used to capture and hold antigens from platelet lysate, human anti-A antibodies reacted with these proteins derived from blood group A₁ platelets; proteins from blood group A₂, O and B platelets showed no reactivity. These results indicate that blood group A antigen is associated with GPIb and GPIIb derived from blood group A₁ but not A₂ platelets.     

IgG anti-Jka/Jkb antibodies are unlikely to fix complement

Antibodies in the Kidd blood group system show a great deal of serological variability, are notoriously elusive and hence evoke difficulties in detection. However, they have been regularly reported as causing severe immediate or delayed haemolytic transfusion reactions and this clinical potential has been largely attributed to their complement binding ability.
In initial investigations on 43 anti-Jk^a/Jk^b sera with a range of titres of IgG antibody only a few seemed to fix complement, though following repeated tests on 20 of these sera a further five were shown to bind complement, making a total of 12 (27.9%) showing evidence of complement binding. Twenty-three sera were unavailable for re-testing. Subsequent tests revealed that only those sera which showed direct agglutination or were positive with an anti-IgM reagent in an indirect antiglobulin test (IAT) fixed complement. Evaluations on the IgG fractions of six selected potent anti-Jk^a sera failed to reveal any complement-fixing ability although all the original sera bound complement avidly and contained variable amounts of IgM antibody, some at very low subagglutinating levels.
These findings challenge past perceptions and give cause for reflection on the changing methodologies and strategies which could unduly compromise the detection of these potentially clinically damaging antibodies.