Argyrophilic nucleolar organizer regions (AgNORs)

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Argyrophilic nucleolar organizer regions (AgNORs) as a proliferative marker inbenign, premalignant and malignant prostatic lesions

Argyrophilic nucleolar organizer regions (AgNORs) as a proliferative marker inbenign, premalignant and malignant prostatic lesions

This is to certify that this dissertation work titled “Argyrophilic Nucleolar Organizer Regions (AgNORs) as A Proliferative Marker In Benign, Premalignant and Malignant Prostatic Lesions” of the candidate Dr. KANIMOZHI.Twith registration Number 201513252 for the award of M.D in the branch of Pathology. I personally verified the urkund.com website for the purpose of plagiarism Check. I found that the uploaded thesis file contains from introduction to conclusion pages and result shows 1% (one) percentage of plagiarism in the dissertation.
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Evaluation of diagnostic accuracy of PAP (papanicolaou) and AgNOR (argyrophilic nucleolar organizer regions) staining in exfoliative cytology of oral mucosa in smokers and non smokers

Evaluation of diagnostic accuracy of PAP (papanicolaou) and AgNOR (argyrophilic nucleolar organizer regions) staining in exfoliative cytology of oral mucosa in smokers and non smokers

It is a complementary diagnostic method which presents several advantages such as rapid and easy execution, low cost, diagnostic safety, efficacy and non-invasiveness, and can be repeated several times (Fontes, 2007; Paiva, 2004 and Remmerbach, 2003 and Sethi, 2003). Papanicolaou(PAP) staining is used as a routine method for the analysis of cytological aspects and permits the identification of basic inflammatory, dysplastic or malignant alterations. Ever since PAP described exfoliative cytology technique, which is non- painful, non-invasive procedure, it has become a valuable tool for cancer screening (Ahmed, 2009). Argyrophilic Nucleolar organizer regions (AgNORs) are located in the cell nucleoli during interphase. They are loops of DNA in which ribosomal RNA is encoded. Nucleolar organiser regions (NORs) are defined as nucleolar components containing a set of argyrophilic proteins, which are selectively stained by silver methods. After silver-staining, the NORs can be easily identified as black dots exclusively localised throughout the nucleolar area, and are called "AgNORs". The NORs' argyrophilia is due to a group of nucleolar proteins, which have a high affinity for silver (AgNOR proteins) (Trere, 2002). NORs are proteins that are associated with the fibrillar centers and dense fibrils of the cell nucleus during interphase and are responsible for the replication of RNA. Thus, the larger the number of NORs, the higher the replication rate of ribosomes and cells. This technique has therefore been used for the quantification of cell proliferation in different tissues and lesions (Cancado, 2001). In the present study, we examined exfoliative cytology from the lateral border of the tongue which is a site associated with a high incidence of oral cancer, in both smokers and nonsmokers. The objective of this study was to determine the influence of smoking habit on oral mucosa with the help of proliferative markers and to determine whether a correlation exists between the results obtained by Papanicolaou staining and by histochemical AgNOR quantification to analyze the accuracy of AgNOR over wide usage of PAP for cytopathology.
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Quantification of Argyrophilic Nucleolar Organizer Regions

Quantification of Argyrophilic Nucleolar Organizer Regions

of the sections, 100 individual cells were examined from the representative areas of the epithelium. The methodical and systematic quantification of AgNORs was carried out using an oil immersion objective (100×). The NORs were distinctly visible as black “dots” or “blebs” of varying sizes, in the brown stained nucleus on a pale yellow back ground of the cells. By careful focusing, AgNOR dots were counted; both intra-nucleolar and extra-nucleolar dots were included in the counting regime. However, nuclei that are over lapped or those with indiscernible AgNORs were excluded. The photomicrographs were obtained using a research microscope.
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A comparative study of AgNOR with pcna immunohistochemical staining in oral squamous cell carcinoma

A comparative study of AgNOR with pcna immunohistochemical staining in oral squamous cell carcinoma

The present study was to compare Argyrophilic Nucleolar Organizer Regions (AgNORs) with Proliferating Cell Nuclear Antigen (PCNA) expression in Oral squamous cell carcinoma (OSCC) and to assess the proliferating activity in OSCC, also to assess the reliability Previously confirmed 30 cases of oral squamous cell carcinomas were taken for the study. Histological sections were prepared from paraffin embedded blocks and processed for AgNOR stain and PCNA stain according to super sensitive polymer HRP method. The statistical evaluation by ANOVA test helped us to compare and correlate between the two methods.
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Role of AgNORs in Thyroid Lesions on Fine Needle
Aspiration Cytology (FNAC) Smears

Role of AgNORs in Thyroid Lesions on Fine Needle Aspiration Cytology (FNAC) Smears

Nucleus is the control centre of cell containing the blue print from which all the components of cell are constructed. This blue print is stored in the form of Deoxyribonucleic acid (DNA) arranged in the form of chromosomes. Nuclei contain dense structures called nucleoli, which are the sites of the ribosomal RNA synthesis and ribosome assembly. The nucleolus plays an essential role in the control of cell proliferation and protein synthesis. Nucleolar organizer regions (NORs) Crocker et al. [13- 15] are loops of ribosomal DNA that are transcribed to ribosomal RNA by RNA polymerase and then translated by the ribosome’s into proteins. NORs are located on each of the short arms on acrocentric chromosomes Ghosh et al. [16,17] NORs are segments of DNA closely associated with nucleolus consisting of non-histone proteins, which are argyrophilic, and can be located by staining with silver nitrate [18] NORs are denatured as black-brown spots, they are termed as AgNORs.
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Interrelation of Argyrophilic Proteins ofNucleolar Organizer Regions andKi-67 withClinical and Morphological Parameters andSurvival in Patients with Non-small CellLung Cancer

Interrelation of Argyrophilic Proteins of Nucleolar Organizer Regions and Ki-67 with Clinical and Morphological Parameters and Survival in Patients with Non-small Cell Lung Cancer

Argyrophilic proteins associated with nucleolar organizer regions (AgNOR) and Ki-67 were studied at non-small cell lung cancer (NSCLC). Tumors with low and high area index (AI) of AgNOR and label index (LI) Ki-67 were defined. AI AgNOR was related to the key clinical and morphological parameters in accordance with TNM system: values Т, N, greatest tumor dimension up to 3 cm and more, disease stage, histogenesis, and tumor differentiation. LI Ki-67 is related to the greatest tumor dimension up to 3 cm and

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Formation of the embryonic organizer is restricted by the competitive influences of Fgf signaling and the SoxB1 transcription factors

Formation of the embryonic organizer is restricted by the competitive influences of Fgf signaling and the SoxB1 transcription factors

We next investigated whether inhibition of SoxB1 function would be sufficient to elicit ectopic expression of the fgfs in the absence of any other additional dorsal or vegetal signals. For this, a dominant negative approach is preferable to a morpholino (MO) knockdown approach. Because of redundancy between different members of the SoxB1 family and maternal expression of at least one of the family members [11], [9], a phenotype is only seen in morpholino injected embryos at stages of development after organizer formation (as reported by Okuda et al. 2010 [11]) and no effect on the early expression of the fgfs was seen (data not shown). This suggest that there is sufficient maternal protein for at least one of the SoxB1 factors to mask any effects of blocking translation of the other factors. However, we have previously shown that a dominant negative Sox3 construct, in which the nuclear localization signals were mutated (hereafter referred to as dnSox3) interferes with the activity of all the SoxB1 factors (by inhibiting their nuclear localization), and was able to elicit ectopic expression of four organizer markers (boz, sqt, gsc and chd), an effect rescued by co-injection with any of the SoxB1 factors [9]. Here, we found that injection of the same dnSox3 construct also induced ectopic expression of both fgf3 and fgf8 at 4.5 hpf in a manner similar to the induction of other markers of organizer (Fig. 1M,N). This effect was more striking at 30% epiboly (approximately 5 hpf), a stage when endogenous fgf expression is more robust (Fig. 1O,P). One concern in using dominant-negative approaches is that the dnSox3 construct might not only block the function of the protein of interest, but might also generate unrelated neomorphic effects. However, in this case, like the effects on other markers of the organizer, this induction of fgf expression by dnSox3 was rescued by overexpression of sox3, sox19a or sox19b with the dnSox3 similarly negating the ability of any of the SoxB1 factors from repressing fgf expression and resulting in reversion to wild type fgf expression (see Fig. S2 in the supplementary material). This rescue experiment indicates that the effects of the dnSox3 described are via inhibiting SoxB1 function and are not neomorphic effects. Together these data indicate that the endogenous SoxB1 proteins repress the expression of fgf3 and fgf8 in the organizer and that interfering with this repression using
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Formation of the head organizer in hydra involves the canonical Wnt pathway

Formation of the head organizer in hydra involves the canonical Wnt pathway

The canonical Wnt pathway is involved in patterning events in a number of bilaterians. In Xenopus and zebrafish, β -catenin is involved in organizer formation, which subsequently sets up the dorsoventral axis (Guger and Gumbiner, 1995; Schneider et al., 1996), while in mice β -catenin affects the formation of the anteroposterior axis (Haegel et al., 1995). In sea urchins β - catenin regulates the patterning of the anteroventral axis so that the vegetal end forms endoderm (Logan et al., 1999). Similarly, in the urochordate, Ciona, the Wnt pathway controls endoderm formation (Imai et al., 2000). The Wnt pathway is also active in axial patterning in protostomes. In Drosophila it is involved in determining the anteroposterior polarity of segments (Nusslein-Volhard and Wieschaus, 1980), and later affects the development of the dorsoventral axis in the wing and leg imaginal discs (Struhl and Basler, 1993). Recently β -catenin has been shown to be involved the process of gastrulation and germ layer specification in a cnidarian, Nematostella vectensis (Wikramanayake et al., 2003).
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Zealous Android's Sophisticated Timetable Reminder And Organizer (ZASTRO) System

Zealous Android's Sophisticated Timetable Reminder And Organizer (ZASTRO) System

The aim is to provide students a sophisticated tool in managing their timetable easily through mobile phone. Zealous Android’s Sophisticated Timetable Reminder & Organizer (ZASTRO) System, is an Android-based Application that will allow students to view their timetable easily and also set a reminder of the next coming class. Through this application, student will always have all useful information about their class, (subjects, time of classes, classroom) and keep themselves organize and ready for class.

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The involvement of tau in nucleolar transcription and the stress response

The involvement of tau in nucleolar transcription and the stress response

There is increasing interest in the non-microtubular roles of the human tau protein. Here we utlised SHSY5Y neuroblastoma cells to investigate tau’s function in the nucleus. This human cell line was chosen as a model system because it expresses human tau at normal levels without the need for overexpression in transfected or transgenic primary neurons. Immunogold electron mi- croscopy using a primary antibody against total tau (henceforth called T-Tau) confirmed the presence of tau in the nucleus localised within the nucleolus in the un- differentiated SHSY5Y cells (Fig. 1a). Nucleolar tau has been traditionally identified using Tau 1 antibody, which identifies tau which is non-phosphorylated on serine 195, 198, 199 and 202 [22], henceforth referred to here as “nP-Tau”. We used an antibody against nP-Tau to in- vestigate the localisation of nucleolar tau using double labelling with fibrillarin (FBL) - a nucleolar marker. Immunofluorescence microscopy showed that nP-Tau was found mainly in the nucleolus co-localised with FBL (Fig. 1b). This colocalisation of nP-Tau with FBL was also confirmed in HeLa cells (Additional file 1: Figure S1A). To explore this association in more neuron-like, non-dividing cells, SHSY5Y cells were differentiated using retinoic acid and brain-derived neurotrophic factor (BDNF). This generates terminally differentiated cells that phenotypical and biochemically resemble neurons, with morphologically distinguishable extended neurites (Additional file 1: Figure S1B) [18]. Immunofluorescence confirmed that nP-Tau colocalises with FBL in differentiated SHSY5Y cells (Fig. 1c).
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Rad53 homologue forkhead-associated kinase A (FhkA) and Ca2+-binding protein 4a (CBP4a) are nucleolar proteins that differentially redistribute during mitosis in Dictyostelium

Rad53 homologue forkhead-associated kinase A (FhkA) and Ca2+-binding protein 4a (CBP4a) are nucleolar proteins that differentially redistribute during mitosis in Dictyostelium

We therefore set out to identify novel cell cycle-linked nucleolar proteins in Dictyostelium and to investigate their dynamics during mitosis in order to better understand the relationship between nucleolar protein localization and dynamics during the cell cycle in this model eukaryote. To identify such proteins, we examined those linked to either Snf12 or NumA1; the only nucleolar proteins in Dictyostelium known to undergo mitotic redistribution. Snf12 possesses a SWIB/MDM2 domain which in higher eukaryotes is also found in the cell cycle regulator MDM2 [25]. MDM2 interacts with DNA damage response protein Chk2 (Rad53 in yeast) suggesting that Dictyostelium Chk2/Rad53 homologue forkhead-associated kinase A (FhkA) could reside within the nucleolus with Snf12 and may also have ties to the cell cycle [29-33]. In higher eu- karyotes Chk2 (Rad53 in yeast) responds to DNA damage by activating several downstream effectors such as p53 and BRCA1 which eventually leads to cell cycle arrest [29,33]. Dictyostelium FhkA may therefore also be in- volved in such cell cycle checkpoint events and is there- fore a good candidate for choosing nucleolar proteins
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The Role of Net1 Phosphorylation in Regulating CDC14 Release During Mitotic Exit

The Role of Net1 Phosphorylation in Regulating CDC14 Release During Mitotic Exit

The RENT complex is composed of three identified components: Net1 a nucleolar protein responsible for maintaining nucleolar integrity and regulating the activation and release of Cdc14 t[r]

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Activation of Epidermal Growth Factor Receptor (pEGFR) and Expression of Argentophilic Nucleolus Organizer Regions (AgNOR) in Seminomas

Activation of Epidermal Growth Factor Receptor (pEGFR) and Expression of Argentophilic Nucleolus Organizer Regions (AgNOR) in Seminomas

Activation of epidermal growth factor receptor (p-EGFR) is one of the triggers in the development of many malignant tumors, and the measurement of Argentophilic Nucleolus Org[r]

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The avian organizer

The avian organizer

A transplanted PMZ is capable of inducing an ectopic primitive streak in epiblast tissue from an early pre-streak embryo lacking a PMZ of its own (Khaner and Eyal-Giladi, 1986; Khaner and Eyal- Giladi, 1989; Khaner, 1998). It could be demonstrated by cell labeling that PMZ cells do not take part in the formation of the axis they induce (Bachvarova et al., 1998). An important secreted protein in the PMZ is the TGF β related factor cVg1 (Seleiro et al., 1996; Shah et al., 1997). cVg1 secreting cells are able to promote the formation of a streak expressing organizer markers when transplanted to the epiblast of the marginal zone, but not of the central disc. The restriction to the marginal zone possibly correlates with the presence of nuclear β− catenin, and thus the activity of a Wnt pathway (Roeser et al., 1999). However, the activity of a Wnt factor is difficult to prove, since these proteins cannot be produced easily in soluble form. Some evidence for the role of a Wnt factor in avian axis induction, organizer induction and cooperation with cVg1 could be obtained applying cells producing the Wnt1 protein (Joubin and Stern, 1999). In order to understand the organizer inducing function of a Nieuwkoop center in zebrafish and Xenopus, it was of great help to identify the homeobox genes dharma/nieuwkoid (Koos and Ho, 1998; Yamanaka et al., 1998) and siamois (Lemaire et al., 1995),
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The head organizer in Hydra

The head organizer in Hydra

An adult Hydra has the shape of a cylindrical shell consisting of two tissue layers: an ectoderm and an endoderm that make up the head, body column and basal disk (Fig. 1). An organizer is usually associated with the early stages of the development of an embryo. As described above, an adult Hydra has organizer activity (see in this issue Meinhardt, 2012). This organizer is necessary to maintain the structure of an adult Hydra in the context of its tissue dynamics, which are in a steady state of production and loss. All the epithelial cells of both the ectoderm and endoderm of the entire body column are continuously in a mitotic state (David and Campbell, 1972). Yet an adult Hydra remains constant in size and shape. Epithelial tissue in the upper ~ 1/3rd of the body column is continuously displaced up the body column (Fig. 1) into the head where it moves out along the tentacles or up the hypo- stome (Campbell, 1967). When reaching the tips of the tentacles or hypostome, the tissue is sloughed (Campbell, 1967; Otto and Campbell, 1977b). Similarly, epithelial tissue in the lower ~ 2/3rds is displaced in a basal direction onto developing buds or further down the column onto the foot. Tissue displaced down to the foot is eventually sloughed on the basal side of the foot (Campbell, 1967), while tissue displaced onto a developing bud is removed from the adult when the bud is mature and detaches from the adult. As a Hydra has no defined lifetime (Martinez, 1998; see in this issue Martinez and Bridge, 2012) this steady state of production and loss of tissue goes on continuously when the animal is fed on a regular basis.
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Transcriptional Integration of Wnt and Nodal Signals in the Establishment of the Spemann Organizer

Transcriptional Integration of Wnt and Nodal Signals in the Establishment of the Spemann Organizer

The Spemann organizer is an essential signaling center in Xenopus germ layer patterning and axis formation. Organizer formation occurs in dorsal blastomeres receiving both maternal Wnt and zygotic Nodal signals. In response to stabilized β catenin, dorsal blastomeres express the closely related transcriptional activators, Siamois (Sia) and Twin (Twn), members of the paired homeobox family. Sia and Twn induce organizer formation and expression of organizer-specific genes, including Goosecoid (Gsc). In spite of the similarity of Sia and Twn sequence and expression pattern, it is unclear whether these factors function equivalently in promoter binding and subsequent transcriptional activation, or if Sia and Twn are required for all aspects of organizer function. Here we report that Sia and Twn activate Gsc transcription by directly binding to a conserved P3 site within the Wnt-responsive proximal element of the Gsc promoter. Sia and Twn form homodimers and heterodimers by direct homeodomain interaction and dimer forms are indistinguishable in both DNA-binding and activation function. Sequential chromatin immunoprecipitation reveals that the endogenous Gsc promoter can be occupied by either Sia or Twn homodimers or Sia-Twn heterodimers. Knockdown of Sia and Twn together, but not individually, results in a failure of organizer gene expression and a disruption of axis formation, consistent with a redundant role for
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Evolution of the organizer and the chordate body plan

Evolution of the organizer and the chordate body plan

As McMahon and Moon (1988) discovered, Wnt1 mRNA injected on the ventro-posterior side of normal eggs shortly after fertilization suffices for subsequent formation of a secondary axis which is as complete as the primary axis and as complete as any developed from a Spemann-Mangold organizer transplant! Clearly the injected em- bryo has developed a second Nieuwkoop center and second organ- izer on the injected side. Various pathway intermediates have axis- promoting or suppressing effects (see Table 1) consistent with their positive or negative action in Wnt signal transduction (reviewed by Moon and Kimelman, 1998). Thus, any component that increases β - catenin levels on the ventro-posterior side leads to twinning (or to rescue of a ventro-posteriorized embryo). These components in- clude excess normal β -catenin or a mutationally stabilized form of it, GBP (the GSK3 binding protein), disheveled (Dsh), dominant nega- tive GSK3, and Wnt ligands. In the opposite direction, any compo- nent that reduces β -catenin levels on the dorso-anterior side leads to ventro-posteriorization. These agents include excess GSK3, CamKII, depletion of β -catenin mRNA from oocytes by complementary oligo- nucleotide/RnaseH treatment (Wylie et al., 1996), and a dominant negative Tcf which binds β -catenin but cannot interact with DNA to enhance transcription. Embryos ventro-posteriorized by such injec- tions seem to lack an organizer, just as do those produced by UV- disruption of microtubules in the first cell cycle or by organizer ablation from the late blastula. These results suggest that β -catenin- stabilizing agents are the maternal materials normally stored at the vegetal pole in association with vesicles and then transported to one side on microtubules. Consistent with these effects, it has been found
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GREEN SUPPLY CHAIN EVENT ORGANIZER (GSCEO): STRATEGY EVENT ORGANIZER BUSINESS IN JAKARTA

GREEN SUPPLY CHAIN EVENT ORGANIZER (GSCEO): STRATEGY EVENT ORGANIZER BUSINESS IN JAKARTA

Coordination effect on Event Organizer performance which means that the existence of good coordination in the company will affect the improvement of Event Organizer Performance. Coordination is one factor that can improve the performance of employees in implementing the work process event organizer in order to realize the goals and results that have been expected. Coordination can be realized in various ways and the choice of means to realize will have important implications on Event Organizer. This means that the resulting implications provide a dynamic color in the Event Organizer, that is when the leader coordinates no other is the effort to make options or preferred solutions or solutions.
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The Spemann Mangold organizer: the control of fate specification and morphogenetic rearrangements during gastrulation in Xenopus

The Spemann Mangold organizer: the control of fate specification and morphogenetic rearrangements during gastrulation in Xenopus

The work reviewed here reflects that important progress has been made in understanding some of the morphogenetic rearrangements that occur during gastrulation in Xenopus. In particular with the description of “vegetal rotation” as an active distortion of vegetal endoderm, that could account for the regionalization of the Spemann-Mangold organizer, and the iden- tification of genes that co-ordinate cell polarity and cell shape changes during convergence extension movements of trunk histotypes. The identification of a “planar-polarity”-like Xwnt11/ Dsh pathway that directly controls cellular behaviour is an impor- tant discovery that raises a number of intriguing questions that need to be addressed in the future. How do Xwnt11 or Dsh induce cell polarity? How do they modulate adhesivity of cells and last but not least how do they impinge on regulators of the actin cytoskel- eton and/or microtubule network? In order to answer these issues it will be essential to determine the precise localization of endo- genous Xwnt11/Dsh and perhaps PAPC or other cadherins in cells that undergo morphogenetic rearrangements. Live imaging using GFP technology will be a powerful tool to trace the dynamics (in spatial and temporal terms) of signalling events and actin and microtubule rearrangements. The elucidation of the non-canonical Xwnt11/Dsh pathway in Xenopus will certainly benefit from genetic studies on planar polarity signalling in Drosophila.
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Autoantibody to RNA polymerase I in scleroderma sera

Autoantibody to RNA polymerase I in scleroderma sera

Autoantibodies to components of the nucleolus are a unique serological feature of patients with scleroderma. There are autoantibodies of several specificities; one type produces a speckled pattern of nucleolar staining in immunofluorescence. In actinomycin D and 5,6- dichloro-beta-D-ribofuranosylbenzimidazole-treated Vero cells, staining was restricted to the fibrillar and not the granular regions. By double immunofluorescence, specific rabbit anti-RNA polymerase I antibodies stained the same fibrillar structures in drug-segregated nucleoli as scleroderma sera. Scleroderma sera immunoprecipitated 13 polypeptides from [35S]methionine-labeled HeLa cell extract with molecular weights ranging from 210,000 to 14,000. Similar polypeptides were precipitated by rabbit anti-RNA polymerase I antibodies, and their common identities were confirmed in immunoabsorption experiments.
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