Neuronal influence on B and H human blood-group antigen expression in rat cochlear cultures

Are ABO Blood Groups or Rh Antigen Perinatal Factors Affecting the Pass Rate of Transient Otoacoustic Emissions Screening Tests in Healthy Newborns during the First 48 h of Life?

Most hospitals recommend performing neonatal hearing screening. Transient evoked otoacoustic emission (TEOAE) tests represent an ideal technique for conducting this process. Previous studies have related the influence of ABO blood group and Rhesus antigens (Rh) on the susceptibility to various pathologies. However, available data about the potential relationship between ABO blood groups, Rh, and TEOAE pass rates are sparse. Recently, several authors concluded that O blood group and Rh+ are possible influential factors of TEOAE pass rates. Significantly different TEOAE amplitude response between the four main ABO blood groups were observed among normal-hearing individuals. Moreover, ABO blood groups were discussed as a possible influential factor for the development of noise-induced hearing loss later in life. The aim of this study was to investigate the relationship between ABO blood groups, Rh, and the first TEOAE pass rates in healthy newborns. Data were retrospectively collected from healthy newborns at the maternity ward of F. Borja hospital in Gandia (Spain). Rh and ABO were compared with the results of TEOAE performed within the first 48 h of life. Results: the study group included 2765 newborns. No significant correlation between ABO blood group or Rh and TEOAE pass rates was observed in comparative tables. Conclusion: ABO blood group and Rhesus antigens do not appear to have a significant impact on the pass rate of TEOAE screening in healthy newborns.

Sequential changes in anti-GAL-1 staining of the rat organ of Corti following amikacin exposure

Hair cell loss and a non-functional epithelial reorganization appeared in the organ of Corti after acoustic or toxic damage. Moreover, in the drug damaged organ of Corti, transient atypical cells were recently described with characteristics of both immature hair cells and/or non-sensory epithelial cells. The phenotype of these atypical cells has been now investigated by using the galectine 1 (GAL-1) antibody. In the normal organ of Corti, this antibody recognizes all the epithelial cells except the sensory hair cells and their supporting cells. At PD 21, transient atypical cells were not stained by GAL-1 antibody, suggesting that they were originated from hair cells or their supporting cells. Later, the organ of Corti was substituted by an epithelial scare, GAL-1 stained. This study also emphasizes the particular resistance of the cochlear apex to degeneration after antibiotic intoxication.

Taste bud expression of human blood group antigens

Some human blood group antigens are expressed by rodent epithelial cells at different stages of differentiation. Since adult taste cells are continually replaced throughout life, we investigated the expression of the H, B, A and Lewisb blood group determinants by cells of the rat fungiform, foliate and vallate papillae. We employed antibodies against the trisaccharide structures of the H, B, and A blood group antigens and against the Lewisb blood group epitope in studies of normal and denervated taste buds. The antibody against the H antigen reacted with the majority of cells in all taste buds and with cells in the spinous layer of the tongue epithelium. The B antigen was expressed by the majority of taste cells but not by other epithelial cells. The expression of the A antigen was significantly less in the fungiform taste buds than in the vallate or foliate taste buds. The A antigen was also abundantly expressed in the acini of the lingual salivary glands. The Lewisb epitope was expressed by a subset of cells in taste buds of the fungiform, foliate and vallate papillae. Taste buds are trophically dependent upon gustatory nerve innervation. Transection of the chorda tympani or the IXth nerve resulted in the loss of expression of these molecules from the gustatory epithelium, indicating that they are expressed only on differentiated taste cells. The blood group antigens are lactoseries carbohydrates; they are differentially expressed in developing cochlear hair cells and olfactory neurons and may play roles in cell-cell recognition, adhesion, and other interactions important in the developing nervous system. They could have similar functions in the taste and olfactory systems, where the receptors are continually renewed and new synapses between the receptors and their neural targets continually form.

H and B human blood-group antigen expression in cochlear hair cells is modulated by thyroxine

The presence of human blood-group antigens in developing and adult hypothyroid rat cochleas was analyzed using antibodies directed against antigens H and B. During postnatal development, hypothyroid rat cochleas exhibited a highly selective expression of both B and H antigens, mainly at the hair cell level. Labeling for antigen B was found throughout the hair cells, whereas the antibody directed against antigen H selectively labeled the apical part of these cells. These immunostaining patterns were similar to those found in normal (euthyroid) rat cochleas, but antigenic expression periods were clearly prolonged. Thus, whereas in normal rat cochleas, the B and H antigenic expression disappears from postnatal day (PD) 9 on, in cochleas of hypothyroid rats the reactivity was intense until PD15; it decreased from this developmental stage, and was negative or only faintly positive at PD30. Therefore, in congenital hypothyroidism, hair cell immunoreactivity is present at developmental stages that are negative in normal rat cochleas. These results suggest that human blood-group antigen expression on the developing cochlear hair cells of rats is modulated by thyroxine and that thyroxine is necessary for the temporal expression pattern and secretion of normal glycoproteins.

Immunocytochemical approach to the structure of human blood group B and H glycoconjugate antigens in the three days old rat cochlea

The possible structure of human blood-group antigens, as found in cochlear hair cells of 3-day-old rats, is suggested. Data were obtained from immunocytochemical studies using 77 antibodies against the major human blood group antigens of the ABO, H, I and Lewis genetic systems. Neither the anti-A-related nor the anti-Lewis-related antibodies showed any positive immunoreaction on hair cells. In contrast, anti-B, anti-AB and anti-H antibodies displayed specific positive immunoreactive patterns on the hair cells. The results suggest that, in immature hair cells, two main glycoconjugate structures of the lactoseries are present: H type 2 antigen, which is the precursor of the B type 2 antigen, and the B type 2 antigen itself. Similar H and B carbohydrate structures have been reported in rat olfactory receptors. The type 2 glycoconjugates carrying these H and B antigens of auditive and olfactory receptors are resistant to fixation and paraffin embedding, suggesting that they might be glycoproteins. These auditive and olfactory H and B antigens must be different from the B-related antigens that are expressed by pseudo-unipolar neurons of rat posterior root ganglia, that are built from type 4 core chains, and that are destroyed by routine paraffin embedding procedures.

Histochemical localization of a beta-galactoside-binding lectin and its binding-sites in developing and adult rat cochlea

The presence of an endogenous rat beta-galactoside-specific lectin (S-Lac) and its specific binding ligands was analyzed, using a rabbit anti-human brain lectin of 14 kDa antibody (anti-HBL-14) and a probe consisting of a biotinylated derivative of the human lectin (HBL-biot) in adult and in developing rat cochleas. At PD1, some epithelial cells of the outer spiral sulcus (OSS) were specifically recognized by the anti-HBL-14 antibody. Then, anti-HBL-14 immunoreactivity progressively appeared in all OSS epithelial cells, and, from PD9 on, it also appeared in inner spiral sulcus (ISS) epithelial cells. Finally, young adult rats exhibited a well defined anti-HBL-14 immunoreactivity in epithelial cells of the inner and outer spiral sulcus. Using the biotinylated probe, from PD3 on, tectorial membrane (TM) and the sensory cells apical surfaces were labelled. The glycoconjugate expression within the developing organ of Corti seems to be highly complex. Lectin was detected in developing and adult epithelial cells surrounding the organ of Corti. In contrast, other glycoconjugates related to B and H human blood group antigens, were transiently present on sensory cells of the organ of Corti. Present findings can be correlated with significant events in development of the cochlea, mainly with cell-cell recognition or cellular adhesion.