The major human blood type system which depends on the presence or absence of two antigens A and B. Type O occurs when neither A nor B is present and AB when both are present. A and B are genetic factors that determine the presence of enzymes for the synthesis of certain glycoproteins mainly in the red cell membrane.
Sets of cell surface antigens located on BLOOD CELLS. They are usually membrane GLYCOPROTEINS or GLYCOLIPIDS that are antigenically distinguished by their carbohydrate moieties.
Erythrocyte isoantigens of the Rh (Rhesus) blood group system, the most complex of all human blood groups. The major antigen Rh or D is the most common cause of erythroblastosis fetalis.
Testing erythrocytes to determine presence or absence of blood-group antigens, testing of serum to determine the presence or absence of antibodies to these antigens, and selecting biocompatible blood by crossmatching samples from the donor against samples from the recipient. Crossmatching is performed prior to transfusion.
A system of universal human blood group isoantigens with many associated subgroups. The M and N traits are codominant and the S and s traits are probably very closely linked alleles, including the U antigen. This system is most frequently used in paternity studies.
Multiple erythrocytic antigens that comprise at least three pairs of alternates and amorphs, determined by one complex gene or possibly several genes at closely linked loci. The system is important in transfusion reactions. Its expression involves the X-chromosome.
An antigenic mismatch between donor and recipient blood. Antibodies present in the recipient's serum may be directed against antigens in the donor product. Such a mismatch may result in a transfusion reaction in which, for example, donor blood is hemolyzed. (From Saunders Dictionary & Encyclopedia of Laboratory Medicine and Technology, 1984).
A group of dominantly and independently inherited antigens associated with the ABO blood factors. They are glycolipids present in plasma and secretions that may adhere to the erythrocytes. The phenotype Le(b) is the result of the interaction of the Le gene Le(a) with the genes for the ABO blood groups.
A blood group related to the ABO, Lewis and I systems. At least five different erythrocyte antigens are possible, some very rare, others almost universal. Multiple alleles are involved in this blood group.
The major sialoglycoprotein of the human erythrocyte membrane. It consists of at least two sialoglycopeptides and is composed of 60% carbohydrate including sialic acid and 40% protein. It is involved in a number of different biological activities including the binding of MN blood groups, influenza viruses, kidney bean phytohemagglutinin, and wheat germ agglutinin.
A blood group consisting mainly of the antigens Fy(a) and Fy(b), determined by allelic genes, the frequency of which varies profoundly in different human groups; amorphic genes are common.
A condition characterized by the abnormal presence of ERYTHROBLASTS in the circulation of the FETUS or NEWBORNS. It is a disorder due to BLOOD GROUP INCOMPATIBILITY, such as the maternal alloimmunization by fetal antigen RH FACTORS leading to HEMOLYSIS of ERYTHROCYTES, hemolytic anemia (ANEMIA, HEMOLYTIC), general edema (HYDROPS FETALIS), and SEVERE JAUNDICE IN NEWBORN.
Antibodies from an individual that react with ISOANTIGENS of another individual of the same species.
Red blood cells. Mature erythrocytes are non-nucleated, biconcave disks containing HEMOGLOBIN whose function is to transport OXYGEN.
Variant forms of the same gene, occupying the same locus on homologous CHROMOSOMES, and governing the variants in production of the same gene product.
The outward appearance of the individual. It is the product of interactions between genes, and between the GENOTYPE and the environment.
Pathological processes or abnormal functions of the PLACENTA.
Antigens from the genus TRICHOPHYTON. Trichophytin has been used in studies of immunological responses to these dermatophytes.
A glycolipid, cross-species antigen that induces production of antisheep hemolysin. It is present on the tissue cells of many species but absent in humans. It is found in many infectious agents.
The semi-permeable outer structure of a red blood cell. It is known as a red cell 'ghost' after HEMOLYSIS.
A high-molecular-weight plasma protein, produced by endothelial cells and megakaryocytes, that is part of the factor VIII/von Willebrand factor complex. The von Willebrand factor has receptors for collagen, platelets, and ristocetin activity as well as the immunologically distinct antigenic determinants. It functions in adhesion of platelets to collagen and hemostatic plug formation. The prolonged bleeding time in VON WILLEBRAND DISEASES is due to the deficiency of this factor.
The administrative procedures involved with acquiring TISSUES or organs for TRANSPLANTATION through various programs, systems, or organizations. These procedures include obtaining consent from TISSUE DONORS and arranging for transportation of donated tissues and organs, after TISSUE HARVESTING, to HOSPITALS for processing and transplantation.
Individuals supplying living tissue, organs, cells, blood or blood components for transfer or transplantation to histocompatible recipients.
Transference of an organ between individuals of the same species or between individuals of different species.
Government required written and driving test given to individuals prior to obtaining an operator's license.
A method of differentiating individuals based on the analysis of qualitative or quantitative biological traits or patterns. This process which has applications in forensics and identity theft prevention includes DNA profiles or DNA fingerprints, hand fingerprints, automated facial recognition, iris scan, hand geometry, retinal scan, vascular patterns, automated voice pattern recognition, and ultrasound of fingers.
The principles of professional conduct concerning the rights and duties of the physician, relations with patients and fellow practitioners, as well as actions of the physician in patient care and interpersonal relations with patient families.
The identification, analysis, and resolution of moral problems that arise in the care of patients. (Bioethics Thesaurus)

Infantile cystinosis in France: genetics, incidence, geographic distribution. (1/1160)

A national distribution of 66 French patients, from 49 sibships, has been studied. Segregation analysis, using the maximum likelihood method, was found to agree with the theoretical values expected in recessive autosomal inheritance. The birthplaces of these patients show an unequal geographic distribution of cystinosis, the incidence being higher in Western France. Compared with the total number of live births during the period 1959 to 1972, the minimum incidence of the condition in the province of Brittany is 1 per 25 909, and the gene frequency 0.0062. In the rest of France, the minimum incidence is 1 per 326,440 and the gene frequency 0.0018. Application of Dahlberg's formula gives a similar result. The mean inbreeding coefficient is 530 X 10(-5), a figure 23 times higher than the mean coefficient of France. An indirect test of inbreeding, the distance between parental birthplaces, was studied, first using the French administrative boundaries, second by using kilometers. This distance was constantly smaller for the parents of patients than for the parents of controls. Analysis of two erythrocyte polymorphisms (ABO and Rh) showed a large excess of group A patients when compared with overall French data. These findings are difficult to interpret on genetic grounds. The genetic reasons for the unequal geographic distribution of cystinosis in France are discussed.  (+info)

Acquisition of human blood group antigens by Schistosoma mansoni. (2/1160)

Juvenile forms of Schistosoma mansoni (schistosomula) have been cultured in human blood of various specificities and tested for the presence of blood group substances on their surfaces. The tests employed were survival following transfer into rhesus monkeys immunized against human blood substances, mixed agglutination reactions, and immunofluorescence. A, B, H AND Lewisb+ antigens were expressed at the surface when the parasites were cultured in blood of appropriate specificities. Rhesus, M N S, AND Duffy antigens could not be detected on the parasite surface following culture. The evidence suggests that the expressed blood group antigens are of host origin and are acquired by the parasite during culture, probably in the form of glycolipids or megaloglycolipids. It is likely that these substances are also acquired by parasites in the bloodstream of man. They may serve to mask surface parasite antigens, and so enable schistosomes to evade parasite-specific humoral or cellular immune responses.  (+info)

H (0) blood group determinant is present on soluble human L-selectin expressed in BHK-cells. (3/1160)

In the present study we show that the H (0) blood group determinant Fuc alpha1-2Gal beta1-4GlcNAc beta1-R is present on N-linked glycans of soluble human L-selectin recombinantly expressed in baby hamster kidney (BHK) cells. The glycans were isolated using complementary HPLC techniques and characterized by a combination of exoglycosidase digestion and mass spectrometry. The linkage of the fucose residues was determined by incubation of the glycans with specific fucosidases. The H blood determinant Fuc alpha1-2Gal beta1-4GlcNAc beta1 was detected for bi-, 2,4 branched tri- and tetraantennary structures. To our knowledge, the proposed oligosaccharide structures represent a new glycosylation motif for recombinant glycoproteins expressed on BHK cells.  (+info)

Poly-N-acetyllactosamine synthesis in branched N-glycans is controlled by complemental branch specificity of I-extension enzyme and beta1,4-galactosyltransferase I. (4/1160)

Poly-N-acetyllactosamine is a unique carbohydrate that can carry various functional oligosaccharides, such as sialyl Lewis X. It has been shown that the amount of poly-N-acetyllactosamine is increased in N-glycans, when they contain Galbeta1-->4GlcNAcbeta1-->6(Galbeta1-->4GlcNAcbeta1 -->2)Manalpha1-->6 branched structure. To determine how this increased synthesis of poly-N-acetyllactosamines takes place, the branched acceptor was incubated with a mixture of i-extension enzyme (iGnT) and beta1, 4galactosyltransferase I (beta4Gal-TI). First, N-acetyllactosamine repeats were more readily added to the branched acceptor than the summation of poly-N-acetyllactosamines formed individually on each unbranched acceptor. Surprisingly, poly-N-acetyllactosamine was more efficiently formed on Galbeta1-->4GlcNAcbeta1-->2Manalpha-->R side chain than in Galbeta1-->4GlcNAcbeta1-->6Manalpha-->R, due to preferential action of iGnT on Galbeta1-->4GlcNAcbeta1-->2Manalpha-->R side chain. On the other hand, galactosylation was much more efficient on beta1,6-linked GlcNAc than beta1,2-linked GlcNAc, preferentially forming Galbeta1-->4GlcNAcbeta1-->6(GlcNAcbeta1-->2)Manalph a1-->6Manbeta -->R. Starting with this preformed acceptor, N-acetyllactosamine repeats were added almost equally to Galbeta1-->4GlcNAcbeta1-->6Manalpha-->R and Galbeta1-->4GlcNAcbeta1-->2Manalpha-->R side chains. Taken together, these results indicate that the complemental branch specificity of iGnT and beta4Gal-TI leads to efficient and equal addition of N-acetyllactosamine repeats on both side chains of GlcNAcbeta1-->6(GlcNAcbeta1-->2)Manalpha1-->6Manbet a-->R structure, which is consistent with the structures found in nature. The results also suggest that the addition of Galbeta1-->4GlcNAcbeta1-->6 side chain on Galbeta1-->4GlcNAcbeta1-->2Man-->R side chain converts the acceptor to one that is much more favorable for iGnT and beta4Gal-TI.  (+info)

A predominantly hydrophobic recognition of H-antigenic sugars by winged bean acidic lectin: a thermodynamic study. (5/1160)

The thermodynamics of binding of winged bean (Psophocarpus tetragonolobus) acidic agglutinin to the H-antigenic oligosaccharide (Fucalpha1-2Galbeta1-4GlcNAc-oMe) and its deoxy and methoxy congeners were determined by isothermal titration calorimetry. We report a relatively hydrophobically driven binding of winged bean acidic agglutinin to the congeners of the above sugar. This conclusion is arrived, from the binding parameters of the fucosyl congeners, the nature of the enthalpy-entropy compensation plots and the temperature dependence of binding enthalpies of some of the congeners. Thus, the binding site of winged bean acidic agglutinin must be quite extended to accommodate the trisaccharide, with non-polar loci that recognize the fucosyl moiety of the H-antigenic determinant.  (+info)

Normal human serum contains natural antibodies reactive with autologous ABO blood group antigens. (6/1160)

It is widely accepted that the serum of healthy individuals contains natural antibodies only against those blood group A or B antigens that are not expressed on the individual's red blood cells. The mechanisms involved in tolerance to autologous blood group antigens remain unclear. In the present study, we show that IgM and IgG antibodies reactive with autologous blood group antigens are present in the immunoglobulin fraction of normal human serum. Natural IgG anti-A antibodies purified by affinity chromatography from IgG of individuals of blood group A exhibited an affinity for A trisaccharide antigen in the micromolar range and agglutinated A red cells at sixfold higher concentrations than those required for agglutination with affinity-purified anti-A IgG of individuals of blood group B. Whereas autoantibodies reactive with self A and B antigens are readily detected in purified IgG and IgM fractions, their expression is restricted in whole serum as a result of complementary interactions between variable regions of antibodies. These observations suggest that tolerance to autologous ABO blood group antigens is dependent on peripheral control of antibody autoreactivity.  (+info)

Purification and characterization of an anti-(A+B) specific lectin from the mushroom Hygrophorus hypothejus. (7/1160)

A lectin (HHL) was isolated from the fruiting body of the mushroom Hygrophorus hypothejus by a combination of affinity chromatography on stromas of group B erythrocytes embedded in polyacrylamide gel, and DEAE-trisacryl and gel filtration chromatography. Its molecular mass, as determined by gel filtration, is estimated to be 68000 kDa and its structure is tetrameric with four identical subunits assembled with non-covalent bonds. HHL agglutinates specifically A and B blood group erythrocytes and in hemagglutination inhibition assays, exhibits sugar-binding specificity toward lactose, the anomeric alpha form being more effective than the beta form.  (+info)

Alteration of sialyl Lewis epitope expression in pterygium. (8/1160)

PURPOSE: Mucin-related antigens are abundantly expressed by the cells of the normal human conjunctiva. The pattern of these antigens in pterygium, and especially the role of Galbeta1-3GlcNAc alpha2,3-sialyltransferase (ST3Gal III), sialyltransferase necessary to build the sialyl-Le(a) (Lewis(a)) antigen, were studied. METHODS: Immunoperoxidase staining was performed on 28 pterygia using different monoclonal antibodies: anti-M1 (against the peptidic core of gastric mucins encoded by MUC 5AC gene), anti-Le(a)(7LE), anti-sialyl Le(a)(NS 19-9), and anti-Le(b)(2-25LE). A serologic Lewis determination was done in 18 patients. ST3Gal III sialyltransferase expression was also studied in 10 healthy conjunctiva and 10 pterygia by reverse transcriptase-polymerase chain reaction (RT-PCR). Glyceraldehyde-3-phosphate-dehydrogenase was used as an endogenous internal control. RESULTS: First, Le(a), sialyl Le(a), and Le(b) immunoreactivities either decreased or were no longer detectable in pterygium goblet cells as opposed to normal conjunctiva. Second, unlike in pterygium, the Lewis immunoreactivity, which is mainly located in the surface epithelial cells in the normal conjunctiva, was occasionally restricted to the epithelial cells of the deep layers. However, M1 mucins did show an identical pattern expression in a normal conjunctiva and pterygium. ST3Gal III expression was significantly lower in pterygium (0.20+/-0.02 AU [arbitrary units]) than in normal conjunctiva (0.95+/-0.12 AU). CONCLUSIONS: ST3Gal III gene is less expressed in pterygium than in normal conjunctiva. This observation could explain the decrease of sialyl Le(a) expression observed in pterygium by immunohistology.  (+info)

The ABO blood-group system is a classification system used in blood transfusion medicine to determine the compatibility of donated blood with a recipient's blood. It is based on the presence or absence of two antigens, A and B, on the surface of red blood cells (RBCs), as well as the corresponding antibodies present in the plasma.

There are four main blood types in the ABO system:

1. Type A: These individuals have A antigens on their RBCs and anti-B antibodies in their plasma.
2. Type B: They have B antigens on their RBCs and anti-A antibodies in their plasma.
3. Type AB: They have both A and B antigens on their RBCs but no natural antibodies against either A or B antigens.
4. Type O: They do not have any A or B antigens on their RBCs, but they have both anti-A and anti-B antibodies in their plasma.

Transfusing blood from a donor with incompatible ABO antigens can lead to an immune response, causing the destruction of donated RBCs and potentially life-threatening complications such as acute hemolytic transfusion reaction. Therefore, it is crucial to match the ABO blood type between donors and recipients before performing a blood transfusion.

Blood group antigens are molecular markers found on the surface of red blood cells (RBCs) and sometimes other types of cells in the body. These antigens are proteins, carbohydrates, or glycoproteins that can stimulate an immune response when foreign antigens are introduced into the body.

There are several different blood group systems, but the most well-known is the ABO system, which includes A, B, AB, and O blood groups. The antigens in this system are called ABO antigens. Individuals with type A blood have A antigens on their RBCs, those with type B blood have B antigens, those with type AB blood have both A and B antigens, and those with type O blood have neither A nor B antigens.

Another important blood group system is the Rh system, which includes the D antigen. Individuals who have this antigen are considered Rh-positive, while those who do not have it are considered Rh-negative.

Blood group antigens can cause complications during blood transfusions and pregnancy if there is a mismatch between the donor's or fetus's antigens and the recipient's antibodies. For example, if a person with type A blood receives type B blood, their anti-B antibodies will attack the foreign B antigens on the donated RBCs, causing a potentially life-threatening transfusion reaction. Similarly, if an Rh-negative woman becomes pregnant with an Rh-positive fetus, her immune system may produce anti-D antibodies that can cross the placenta and attack the fetal RBCs, leading to hemolytic disease of the newborn.

It is important for medical professionals to determine a patient's blood group before performing a transfusion or pregnancy-related procedures to avoid these complications.

The Rh-Hr blood group system is a complex system of antigens found on the surface of red blood cells (RBCs), which is separate from the more well-known ABO blood group system. The term "Rh" refers to the Rhesus monkey, as these antigens were first discovered in rhesus macaques.

The Rh system consists of several antigens, but the most important ones are the D antigen (also known as the Rh factor) and the hr/Hr antigens. The D antigen is the one that determines whether a person's blood is Rh-positive or Rh-negative. If the D antigen is present, the blood is Rh-positive; if it is absent, the blood is Rh-negative.

The hr/Hr antigens are less well known but can still cause problems in blood transfusions and pregnancy. The Hr antigen is relatively rare, found in only about 1% of the population, while the hr antigen is more common.

When a person with Rh-negative blood is exposed to Rh-positive blood (for example, through a transfusion or during pregnancy), their immune system may produce antibodies against the D antigen. This can cause problems if they later receive a transfusion with Rh-positive blood or if they become pregnant with an Rh-positive fetus.

The Rh-Hr blood group system is important in blood transfusions and obstetrics, as it can help ensure that patients receive compatible blood and prevent complications during pregnancy.

Blood grouping, also known as blood typing, is the process of determining a person's ABO and Rh (Rhesus) blood type. The ABO blood group system includes four main blood types: A, B, AB, and O, based on the presence or absence of antigens A and B on the surface of red blood cells. The Rh blood group system is another important classification system that determines whether the Rh factor (a protein also found on the surface of red blood cells) is present or absent.

Knowing a person's blood type is crucial in transfusion medicine to ensure compatibility between donor and recipient blood. If a patient receives an incompatible blood type, it can trigger an immune response leading to serious complications such as hemolysis (destruction of red blood cells), kidney failure, or even death.

Crossmatching is a laboratory test performed before a blood transfusion to determine the compatibility between the donor's and recipient's blood. It involves mixing a small sample of the donor's red blood cells with the recipient's serum (the liquid portion of the blood containing antibodies) and observing for any agglutination (clumping) or hemolysis. If there is no reaction, the blood is considered compatible, and the transfusion can proceed.

In summary, blood grouping and crossmatching are essential tests in transfusion medicine to ensure compatibility between donor and recipient blood and prevent adverse reactions that could harm the patient's health.

The MNSs blood group system is one of the human blood group systems, which is a classification of blood types based on the presence or absence of specific antigens on the surface of red blood cells (RBCs). This system is named after the first two letters of the surnames of the discoverers, Landsteiner and Levine, and the "s" stands for "slight."

The MNSs system includes three main antigens: M, N, and S. The M and N antigens are found on nearly all individuals, except for those who are genetically predisposed to lack both M and N antigens (M+N- or M-N-). These individuals have the "null" phenotype, also known as the "Ms" phenotype.

The S antigen is present in about 80% of people, while the s antigen is found in approximately 20% of people. The presence or absence of these antigens determines an individual's MNSs blood type. There are eight main MNSs blood types: M, N, MN, MS, NS, M+m, N+s, and M+N+S+s+.

The clinical significance of the MNSs system is relatively low compared to other blood group systems like ABO and Rh. However, it can still play a role in transfusion medicine, as antibodies against MNSs antigens may cause hemolytic transfusion reactions or hemolytic disease of the newborn (HDN) in rare cases. Therefore, it is essential to consider the MNSs blood group when performing pretransfusion testing and during pregnancy to ensure compatible blood products and prevent complications.

The Kell blood-group system is one of the human blood group systems, which is a set of red blood cell antigens (proteins or carbohydrates) found on the surface of red blood cells. The Kell system consists of more than 30 antigens, but the two most important ones are K and k.

The Kell antigen is inherited in an autosomal dominant manner, meaning that if an individual inherits one Kell antigen from either parent, they will express the Kell antigen on their red blood cells. The k antigen is a weaker form of the Kell antigen and is also inherited in an autosomal dominant manner.

Individuals who are Kell positive (K+) can produce antibodies against the Kell antigen if they are exposed to it through blood transfusion or pregnancy. These antibodies can cause hemolytic transfusion reactions or hemolytic disease of the newborn in subsequent pregnancies with a Kell-negative (K-) fetus.

Therefore, it is important to determine the Kell status of both donors and recipients in blood transfusions and pregnant women to prevent complications.

Blood group incompatibility refers to a situation where the blood type of a donor and a recipient are not compatible, leading to an immune response and destruction of the donated red blood cells. This is because the recipient's immune system recognizes the donor's red blood cells as foreign due to the presence of incompatible antigens on their surface.

The most common type of blood group incompatibility occurs between individuals with different ABO blood types, such as when a person with type O blood receives type A, B, or AB blood. This can lead to agglutination and hemolysis of the donated red blood cells, causing potentially life-threatening complications such as hemolytic transfusion reaction.

Another type of blood group incompatibility occurs between Rh-negative mothers and their Rh-positive fetuses. If a mother's immune system is exposed to her fetus's Rh-positive red blood cells during pregnancy or childbirth, she may develop antibodies against them. This can lead to hemolytic disease of the newborn if the mother becomes pregnant with another Rh-positive fetus in the future.

To prevent these complications, it is essential to ensure that donated blood is compatible with the recipient's blood type before transfusion and that appropriate measures are taken during pregnancy and childbirth to prevent sensitization of Rh-negative mothers to Rh-positive red blood cells.

The Lewis blood-group system is one of the human blood group systems, which is based on the presence or absence of two antigens: Lea and Leb. These antigens are carbohydrate structures that can be found on the surface of red blood cells (RBCs) as well as other cells and in various body fluids.

The Lewis system is unique because its antigens are not normally present at birth, but instead develop during early childhood or later in life due to the action of certain enzymes in the digestive tract. The production of Lea and Leb antigens depends on the activity of two genes, FUT3 (also known as Lewis gene) and FUT2 (also known as Secretor gene).

There are four main phenotypes or blood types in the Lewis system:

1. Le(a+b-): This is the most common phenotype, where individuals have both Lea and Leb antigens on their RBCs.
2. Le(a-b+): In this phenotype, individuals lack the Lea antigen but have the Leb antigen on their RBCs.
3. Le(a-b-): This is a rare phenotype where neither Lea nor Leb antigens are present on the RBCs.
4. Le(a+b+): In this phenotype, individuals have both Lea and Leb antigens on their RBCs due to the simultaneous expression of FUT3 and FUT2 genes.

The Lewis blood-group system is not typically associated with transfusion reactions or hemolytic diseases, unlike other blood group systems such as ABO and Rh. However, the presence or absence of Lewis antigens can still have implications for certain medical conditions and tests, including:

* Infectious diseases: Some bacteria and viruses can use the Lewis antigens as receptors to attach to and infect host cells. For example, Helicobacter pylori, which causes gastritis and peptic ulcers, binds to Lea antigens in the stomach.
* Autoimmune disorders: In some cases, autoantibodies against Lewis antigens have been found in patients with autoimmune diseases such as rheumatoid arthritis and systemic lupus erythematosus (SLE).
* Pregnancy: The Lewis antigens can be expressed on the surface of placental cells, and changes in their expression have been linked to pregnancy complications such as preeclampsia and fetal growth restriction.
* Blood typing: Although not a primary factor in blood transfusion compatibility, the Lewis blood-group system is still considered when determining the best match for patients who require frequent transfusions or organ transplants.

The P blood group system is one of the rarest blood group systems in humans, with only a few antigens discovered so far. The main antigens in this system are P1 and P, which can be either present or absent on red blood cells (RBCs). The presence or absence of these antigens determines an individual's P blood group type.

The P1 antigen is a carbohydrate structure found on the surface of RBCs in individuals with the P1 phenotype, while those with the p phenotype lack this antigen. The P antigen is a protein found on the surface of RBCs in both P1 and p individuals.

Individuals with the P1 phenotype can develop antibodies against the P antigen if they are exposed to RBCs that lack the P1 antigen, such as those from a person with the p phenotype. Similarly, individuals with the p phenotype can develop antibodies against the P1 antigen if they are exposed to RBCs that have the P1 antigen.

Transfusion reactions can occur if an individual receives blood from a donor with a different P blood group type, leading to the destruction of RBCs and potentially life-threatening complications. Therefore, it is essential to determine an individual's P blood group type before transfusing blood or performing other medical procedures that involve RBCs.

Overall, the P blood group system is a complex and relatively rare system that requires careful consideration in medical settings to ensure safe and effective treatment.

Glycophorin is a type of protein found on the surface of red blood cells, also known as erythrocytes. These proteins are heavily glycosylated, meaning they have many carbohydrate chains attached to them. Glycophorins play a crucial role in maintaining the structure and flexibility of the red blood cell membrane, and they also help to mediate interactions between the red blood cells and other cells or molecules in the body.

There are several different types of glycophorin proteins, including glycophorin A, B, C, and D. Glycophorin A is the most abundant type and is often used as a marker for identifying the ABO blood group. Mutations in the genes that encode glycophorin proteins can lead to various blood disorders, such as hereditary spherocytosis and hemolytic anemia.

The Duffy blood group system is a system of identifying blood types based on the presence or absence of certain antigens on the surface of red blood cells. The antigens in this system are proteins called Duffy antigens, which are receptors for the malarial parasite Plasmodium vivax.

There are two major Duffy antigens, Fya and Fyb, and individuals can be either positive or negative for each of these antigens. This means that there are four main Duffy blood types: Fy(a+b-), Fy(a-b+), Fy(a+b+), and Fy(a-b-).

The Duffy blood group system is important in blood transfusions to prevent a potentially dangerous immune response known as a transfusion reaction. If a person receives blood that contains antigens that their body recognizes as foreign, their immune system may attack the transfused red blood cells, leading to symptoms such as fever, chills, and in severe cases, kidney failure or even death.

Additionally, the Duffy blood group system has been found to be associated with susceptibility to certain diseases. For example, individuals who are negative for both Fya and Fyb antigens (Fy(a-b-)) are resistant to infection by Plasmodium vivax, one of the malarial parasites that causes malaria in humans. This is because the Duffy antigens serve as receptors for the parasite to enter and infect red blood cells.

Erythroblastosis, fetal is a medical condition that occurs in the fetus or newborn when there is an incompatibility between the fetal and maternal blood types, specifically related to the Rh factor or ABO blood group system. This incompatibility leads to the destruction of the fetal red blood cells by the mother's immune system, resulting in the release of bilirubin, which can cause jaundice, anemia, and other complications.

In cases where the mother is Rh negative and the fetus is Rh positive, the mother may develop antibodies against the Rh factor during pregnancy or after delivery, leading to hemolysis (breakdown) of the fetal red blood cells in subsequent pregnancies if preventive measures are not taken. This is known as hemolytic disease of the newborn (HDN).

Similarly, incompatibility between the ABO blood groups can also lead to HDN, although it is generally less severe than Rh incompatibility. In this case, the mother's immune system produces antibodies against the fetal red blood cells, leading to their destruction and subsequent complications.

Fetal erythroblastosis is a serious condition that can lead to significant morbidity and mortality if left untreated. Treatment options include intrauterine transfusions, phototherapy, and exchange transfusions in severe cases. Preventive measures such as Rh immune globulin (RhIG) injections can help prevent the development of antibodies in Rh-negative mothers, reducing the risk of HDN in subsequent pregnancies.

Isoantibodies are antibodies produced by the immune system that recognize and react to antigens (markers) found on the cells or tissues of another individual of the same species. These antigens are typically proteins or carbohydrates present on the surface of red blood cells, but they can also be found on other cell types.

Isoantibodies are formed when an individual is exposed to foreign antigens, usually through blood transfusions, pregnancy, or tissue transplantation. The exposure triggers the immune system to produce specific antibodies against these antigens, which can cause a harmful immune response if the individual receives another transfusion or transplant from the same donor in the future.

There are two main types of isoantibodies:

1. Agglutinins: These are IgM antibodies that cause red blood cells to clump together (agglutinate) when mixed with the corresponding antigen. They develop rapidly after exposure and can cause immediate transfusion reactions or hemolytic disease of the newborn in pregnant women.
2. Hemolysins: These are IgG antibodies that destroy red blood cells by causing their membranes to become more permeable, leading to lysis (bursting) of the cells and release of hemoglobin into the plasma. They take longer to develop but can cause delayed transfusion reactions or hemolytic disease of the newborn in pregnant women.

Isoantibodies are detected through blood tests, such as the crossmatch test, which determines compatibility between a donor's and recipient's blood before transfusions or transplants.

Erythrocytes, also known as red blood cells (RBCs), are the most common type of blood cell in circulating blood in mammals. They are responsible for transporting oxygen from the lungs to the body's tissues and carbon dioxide from the tissues to the lungs.

Erythrocytes are formed in the bone marrow and have a biconcave shape, which allows them to fold and bend easily as they pass through narrow blood vessels. They do not have a nucleus or mitochondria, which makes them more flexible but also limits their ability to reproduce or repair themselves.

In humans, erythrocytes are typically disc-shaped and measure about 7 micrometers in diameter. They contain the protein hemoglobin, which binds to oxygen and gives blood its red color. The lifespan of an erythrocyte is approximately 120 days, after which it is broken down in the liver and spleen.

Abnormalities in erythrocyte count or function can lead to various medical conditions, such as anemia, polycythemia, and sickle cell disease.

An allele is a variant form of a gene that is located at a specific position on a specific chromosome. Alleles are alternative forms of the same gene that arise by mutation and are found at the same locus or position on homologous chromosomes.

Each person typically inherits two copies of each gene, one from each parent. If the two alleles are identical, a person is said to be homozygous for that trait. If the alleles are different, the person is heterozygous.

For example, the ABO blood group system has three alleles, A, B, and O, which determine a person's blood type. If a person inherits two A alleles, they will have type A blood; if they inherit one A and one B allele, they will have type AB blood; if they inherit two B alleles, they will have type B blood; and if they inherit two O alleles, they will have type O blood.

Alleles can also influence traits such as eye color, hair color, height, and other physical characteristics. Some alleles are dominant, meaning that only one copy of the allele is needed to express the trait, while others are recessive, meaning that two copies of the allele are needed to express the trait.

A phenotype is the physical or biochemical expression of an organism's genes, or the observable traits and characteristics resulting from the interaction of its genetic constitution (genotype) with environmental factors. These characteristics can include appearance, development, behavior, and resistance to disease, among others. Phenotypes can vary widely, even among individuals with identical genotypes, due to differences in environmental influences, gene expression, and genetic interactions.

Placental diseases, also known as placental pathologies, refer to a group of conditions that affect the development and function of the placenta during pregnancy. The placenta is an organ that develops in the uterus during pregnancy and provides oxygen and nutrients to the developing fetus while removing waste products.

Placental diseases can have serious consequences for both the mother and the fetus, including preterm labor, growth restriction, stillbirth, and long-term health problems for the child. Some common placental diseases include:

1. Placental abruption: This occurs when the placenta separates from the uterine wall before delivery, causing bleeding and potentially harming the fetus.
2. Placental previa: This is a condition where the placenta implants in the lower part of the uterus, covering the cervix. It can cause bleeding and may require cesarean delivery.
3. Preeclampsia: This is a pregnancy-related disorder characterized by high blood pressure and damage to organs such as the liver and kidneys. Placental dysfunction is thought to play a role in its development.
4. Intrauterine growth restriction (IUGR): This occurs when the fetus does not grow properly due to poor placental function, leading to low birth weight and potential health problems.
5. Chorioamnionitis: This is an infection of the membranes surrounding the fetus, which can lead to preterm labor and other complications.
6. Placental infarction: This occurs when a portion of the placenta dies due to a lack of blood flow, which can lead to growth restriction or stillbirth.

Prompt diagnosis and treatment of placental diseases are essential for ensuring the best possible outcomes for both the mother and the fetus.

Trichophytin is not a medical condition or diagnosis, but rather a preparation used in skin tests to help identify whether someone has a sensitivity or allergic reaction to the fungus called Trichophyton. This fungus can cause various skin infections such as athlete's foot, ringworm, and jock itch. The trichophytin preparation contains antigens derived from the Trichophyton fungus, which are introduced into the skin to trigger an immune response. If a person is allergic or sensitive to the fungus, their body will mount a reaction, which can be observed and measured as part of the skin test. This information helps healthcare professionals diagnose and manage fungal infections and related allergies.

The Forssman antigen is a type of heterophile antigen, which is a substance that can stimulate an immune response in animals of different species. It was first discovered by the Swedish bacteriologist, John Forssman, in 1911. The Forssman antigen is found in a variety of tissues and organs, including the kidney, liver, and brain, in many different animal species, including humans.

The Forssman antigen is unique because it can induce the production of antibodies that cross-react with tissues from other species. This means that an immune response to the Forssman antigen in one species can also recognize and react with similar antigens in another species, leading to the possibility of cross-species immune reactions.

The Forssman antigen is a complex glycosphingolipid molecule that is found on the surface of cells. It is not clear what role, if any, the Forssman antigen plays in normal physiological processes. However, its presence has been implicated in various disease processes, including autoimmune disorders and transplant rejection.

In summary, the Forssman antigen is a heterophile antigen found in a variety of tissues and organs in many different animal species, including humans. It can induce cross-reacting antibodies and has been implicated in various disease processes.

An erythrocyte, also known as a red blood cell, is a type of cell that circulates in the blood and is responsible for transporting oxygen throughout the body. The erythrocyte membrane refers to the thin, flexible barrier that surrounds the erythrocyte and helps to maintain its shape and stability.

The erythrocyte membrane is composed of a lipid bilayer, which contains various proteins and carbohydrates. These components help to regulate the movement of molecules into and out of the erythrocyte, as well as provide structural support and protection for the cell.

The main lipids found in the erythrocyte membrane are phospholipids and cholesterol, which are arranged in a bilayer structure with the hydrophilic (water-loving) heads facing outward and the hydrophobic (water-fearing) tails facing inward. This arrangement helps to maintain the integrity of the membrane and prevent the leakage of cellular components.

The proteins found in the erythrocyte membrane include integral proteins, which span the entire width of the membrane, and peripheral proteins, which are attached to the inner or outer surface of the membrane. These proteins play a variety of roles, such as transporting molecules across the membrane, maintaining the shape of the erythrocyte, and interacting with other cells and proteins in the body.

The carbohydrates found in the erythrocyte membrane are attached to the outer surface of the membrane and help to identify the cell as part of the body's own immune system. They also play a role in cell-cell recognition and adhesion.

Overall, the erythrocyte membrane is a complex and dynamic structure that plays a critical role in maintaining the function and integrity of red blood cells.

Von Willebrand factor (vWF) is a large multimeric glycoprotein that plays a crucial role in hemostasis, the process which leads to the cessation of bleeding and the formation of a blood clot. It was named after Erik Adolf von Willebrand, a Finnish physician who first described the disorder associated with its deficiency, known as von Willebrand disease (vWD).

The primary functions of vWF include:

1. Platelet adhesion and aggregation: vWF mediates the initial attachment of platelets to damaged blood vessel walls by binding to exposed collagen fibers and then interacting with glycoprotein Ib (GPIb) receptors on the surface of platelets, facilitating platelet adhesion. Subsequently, vWF also promotes platelet-platelet interactions (aggregation) through its interaction with platelet glycoprotein IIb/IIIa (GPIIb/IIIa) receptors under high shear stress conditions found in areas of turbulent blood flow, such as arterioles and the capillary bed.

2. Transport and stabilization of coagulation factor VIII: vWF serves as a carrier protein for coagulation factor VIII (FVIII), protecting it from proteolytic degradation and maintaining its stability in circulation. This interaction between vWF and FVIII is essential for the proper functioning of the coagulation cascade, particularly in the context of vWD, where impaired FVIII function can lead to bleeding disorders.

3. Wound healing: vWF contributes to wound healing by promoting platelet adhesion and aggregation at the site of injury, which facilitates the formation of a provisional fibrin-based clot that serves as a scaffold for tissue repair and regeneration.

In summary, von Willebrand factor is a vital hemostatic protein involved in platelet adhesion, aggregation, coagulation factor VIII stabilization, and wound healing. Deficiencies or dysfunctions in vWF can lead to bleeding disorders such as von Willebrand disease.

Tissue and organ procurement is the process of obtaining viable tissues and organs from deceased or living donors for the purpose of transplantation, research, or education. This procedure is performed by trained medical professionals in a sterile environment, adhering to strict medical standards and ethical guidelines. The tissues and organs that can be procured include hearts, lungs, livers, kidneys, pancreases, intestines, corneas, skin, bones, tendons, and heart valves. The process involves a thorough medical evaluation of the donor, as well as consent from the donor or their next of kin. After procurement, the tissues and organs are preserved and transported to recipients in need.

A tissue donor is an individual who has agreed to allow organs and tissues to be removed from their body after death for the purpose of transplantation to restore the health or save the life of another person. The tissues that can be donated include corneas, heart valves, skin, bone, tendons, ligaments, veins, and cartilage. These tissues can enhance the quality of life for many recipients and are often used in reconstructive surgeries. It is important to note that tissue donation does not interfere with an open casket funeral or other cultural or religious practices related to death and grieving.

Organ transplantation is a surgical procedure where an organ or tissue from one person (donor) is removed and placed into another person (recipient) whose organ or tissue is not functioning properly or has been damaged beyond repair. The goal of this complex procedure is to replace the non-functioning organ with a healthy one, thereby improving the recipient's quality of life and overall survival.

Organs that can be transplanted include the heart, lungs, liver, kidneys, pancreas, and intestines. Tissues such as corneas, skin, heart valves, and bones can also be transplanted. The donor may be deceased or living, depending on the type of organ and the medical circumstances.

Organ transplantation is a significant and life-changing event for both the recipient and their families. It requires careful evaluation, matching, and coordination between the donor and recipient, as well as rigorous post-transplant care to ensure the success of the procedure and minimize the risk of rejection.

The Automobile Driver Examination is a medical definition that refers to the process of evaluating an individual's physical and mental fitness to operate a motor vehicle. The examination typically includes a series of tests designed to assess the person's vision, hearing, reaction time, cognitive abilities, and overall health status.

The purpose of the examination is to ensure that drivers are capable of operating their vehicles safely and reducing the risk of accidents on the road. In many jurisdictions, driver examinations are required for individuals seeking to obtain a new driver's license or renew an existing one, particularly for those in certain age groups or with medical conditions that may affect their ability to drive.

The examination is usually conducted by a licensed healthcare professional, such as a doctor or nurse practitioner, who has been trained to assess the driver's fitness to operate a motor vehicle. The results of the examination are then used to determine whether the individual is medically fit to drive and what, if any, restrictions or accommodations may be necessary to ensure their safety and the safety of others on the road.

Biometric identification is the use of automated processes to identify a person based on their unique physical or behavioral characteristics. These characteristics, known as biometrics, can include fingerprints, facial recognition, iris scans, voice patterns, and other distinctive traits that are difficult to replicate or forge. Biometric identification systems work by capturing and analyzing these features with specialized hardware and software, comparing them against a database of known individuals to find a match.

Biometric identification is becoming increasingly popular in security applications, such as access control for buildings and devices, border control, and law enforcement. It offers several advantages over traditional methods of identification, such as passwords or ID cards, which can be lost, stolen, or easily replicated. By contrast, biometric traits are unique to each individual and cannot be easily changed or duplicated.

However, there are also concerns around privacy and the potential for misuse of biometric data. It is important that appropriate safeguards are in place to protect individuals' personal information and prevent unauthorized access or use.

Medical ethics is a branch of ethics that deals with moral issues in medical care, research, and practice. It provides a framework for addressing questions related to patient autonomy, informed consent, confidentiality, distributive justice, beneficentia (doing good), and non-maleficence (not doing harm). Medical ethics also involves the application of ethical principles such as respect for persons, beneficence, non-maleficence, and justice to specific medical cases and situations. It is a crucial component of medical education and practice, helping healthcare professionals make informed decisions that promote patient well-being while respecting their rights and dignity.

Clinical ethics refers to the branch of applied ethics that deals with ethical issues in clinical settings, such as hospitals and other healthcare facilities. It involves the application of moral principles and values to decision-making in clinical practice, with the aim of promoting patient autonomy, beneficence, non-maleficence, and justice.

Clinical ethics often involves addressing complex ethical dilemmas that arise in the context of patient care, such as end-of-life decisions, informed consent, confidentiality, resource allocation, and research involving human subjects. Clinical ethicists may work as part of an institutional ethics committee or provide consultation services to healthcare providers, patients, and families facing ethical challenges.

The principles of clinical ethics are grounded in respect for patient autonomy, which includes the right to make informed decisions about their own care. Beneficence refers to the obligation to act in the best interests of the patient, while non-maleficence involves avoiding harm to the patient. Justice requires fair and equitable distribution of healthcare resources and respect for the rights and dignity of all patients.

Effective clinical ethics decision-making also involves careful consideration of contextual factors, such as cultural differences, religious beliefs, and social values, that may influence ethical judgments in particular cases. Clinical ethicists use a variety of methods to analyze ethical issues, including case consultation, ethical analysis frameworks, and moral deliberation processes that involve all stakeholders in the decision-making process.

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