Percentage Of Ig Research Articles

Does the Percentage of Investment Grades Given by Rating Agencies Impact their Market Share?

The credit rating industry has controlled by three core credit rating agencies; Fitch, Moody’s, and S&P that are contributing to financial markets by providing reliable and transparent credit rating information on which stakeholders can rely. These key players could manipulate this information by allocating high percentages of quality ratings just for the sake of increasing their market shares. This research is conducting to examine the impact of assigning the percentage of investment grades given by CRA’s on their market share. This research will attain following objectives: firstly, to identify quality ratings assigned for each set of top banks from UK & USA and categories them yearly; secondly, to examine their market share on the basis of percentage of IG grade given; thirdly, to access the modeling and impacts of the financial crisis on the market share of CRA’s; finally, to determine the relationship between CRA’s market share and percentage of IG given. This research gives a detailed analysis of the percentage of IG assigned by CRA’s and their market share which consists of general analysis and econometric analysis. Moreover, the research methodology is a quantitative method for achieving all research objectives. For general analysis, we make a comparative study to find the impacts of high-quality ratings against their market share and evaluate the growth rate in their market share. Whereas, for econometrics analysis, we regress the market share of CRA’s against the percentage of investment grades given and use lagged variables to understand the changes in market share. Besides, this allows us to find the relationship between CRA’s and the percentage of IG given. Hence, the results from both analyses have exposed that there is a positive correlation between CRA’s market share and the percentage of IG given. It is revealed that there is an increase in the market share of CRA’s on assigning a high percentage of IG given by CRA’s and a negative growth rate shown in market share for those years in which they allocate less number of quality ratings. However, due to financial crisis and adjustment in credit rating standards, there is a general fall in the number of ratings assigned by CRA’s which very influences their market share. Keywords: investment grades; market share; credit rating agencies; financial crisis; modeling of banks ratings.

Potencijalni prediktivni biljezi postoperativnih komplikacija kolorektalnog karcinoma temeljeni na omjeru nezrelih granulocita i limfocita, udjelu nezrelih granulocita te IG i IT omjeru

Potencijalni prediktivni biljezi postoperativnih komplikacija kolorektalnog karcinoma temeljeni na omjeru nezrelih granulocita i limfocita, udjelu nezrelih granulocita te IG i IT omjeru

Monoclonal antibodies to snakehead, Channa striata immunoglobulins: Detection and quantification of immunoglobulin-positive cells in blood and lymphoid organs

Snakehead Channa striata is an important freshwater food fish in many Southeast Asian countries. Three monoclonal antibodies (C9, C10 and D10) were developed against purified serum immunoglobulins of Channa striata (Cs-Ig) and characterized. C9 and D10 MAbs were specific to heavy chain, while C10 MAb detected only unreduced Cs-Ig in western blotting. In competitive ELISA, C9 and C10 MAbs were specific to C. striata Ig and showed no cross reactivity with serum Ig of other fish species i.e. Channa punctatus, Channa marulius, Clarias batrachus and Labeo rohita. D10 MAb showed reactivity to serum Ig of C. striata and C. marulius. In FACS analysis of gated lymphocytes, the percentage of Ig+ cells detected by C9 MAb was 18.2%, 27.7% and 10.3% in blood, spleen and kidney, respectively ( n = 3, body weight 500–600 g). However, only a few cells (0.5%) were found to be Ig+ in thymus ( n = 5). C9 MAb was also successfully employed to demonstrate Ig+ cells in blood smears and formalin fixed sections of spleen and kidney. These findings suggest that the spleen plays an important role in humoral immunity as compared to head kidney. Further, these MAbs can be useful immunological tool in monitoring health status of cultured C. striata.

Improving passive transfer of immunoglobulins in calves. I: Dose effect of feeding a commercial colostrum replacer

The objective of this study was to describe the effects of feeding 1 or 2 doses of a commercially available colostrum-derived colostrum replacer (CR) on passive transfer of immunoglobulins (Ig) in newborn dairy calves, including IgG, IgG1, IgG2, IgA, and IgM. Newborn calves were removed from the dam before suckling and randomly assigned to 1 of 3 treatment groups: group 1 were fed 1 package (100g of IgG) of CR product, group 2 was fed 2 packages (200g of IgG) of the same CR product, and group 3 was fed 3.8L of maternal colostrum. All colostrum treatments were fed using an esophageal tube feeder within 2h of birth. Blood samples collected before colostrum feeding and at 24h of age were tested for serum total protein and Ig concentrations. Mean 24-h serum total protein (TP) and IgG concentrations were significantly lower for calves in group 1 (n = 24; TP = 4.9 g/dL, IgG = 9.6mg/mL) compared with calves in groups 2 or 3. There was no difference in 24-h serum TP or IgG concentrations between calves in group 2 (n = 23; TP = 5.5 g/dL, IgG = 19.0mg/mL) and calves in group 3 (n = 22; TP = 5.7 g/dL, IgG = 20.7mg/mL). Fifty-four, 100, and 91% of calves in groups 1, 2 and 3 achieved acceptable passive transfer (24-h serum IgG ≥10mg/mL), respectively. Statistically significant but numerically small differences existed between calves in groups 2 and 3 for some 24-h serum Ig classes and subclasses (mean serum concentrations of IgG2, IgA, IgM) and for the relative percentages of Ig classes and subclasses (IgA, IgM, and IgG as a percentage of total Ig; IgG1 and IgG2 as a percentage of total IgG).

Anti‐Erythrocyte Antibodies and Disease Associations in Anemic and Nonanemic Dogs

Flow cytometry has been used to detect anti-red blood cell (RBC) antibodies in dogs with immune-mediated hemolytic anemia (IMHA), but the prevalence of anti-RBC antibodies in anemic and nonanemic dogs with a variety of different diseases has not been assessed previously. We hypothesized that anti-RBC antibodies would be more common in anemic dogs and in dogs with immune-mediated disorders and cancer. Blood samples from 292 dogs were analyzed prospectively by flow cytometry for anti-RBC antibodies. Blood samples from 147 anemic and 145 nonanemic dogs were evaluated by flow cytometry to detect surface-bound immunoglobulin (Ig) G and IgM antibodies on RBC. Disease associations with RBC antibodies were determined, as was the correlation between disease status and the percentage of Ig(+) RBC. The specificity and sensitivity of flow cytometry and clinical variables for the diagnosis of IMHA were compared by Bayesian analysis. Anemic dogs were significantly more likely to be positive for anti-RBC antibodies (IgG, IgM, or both) than nonanemic dogs. Anemic dogs also had significantly higher percentages of Ig(+) RBC than nonanemic dogs, whereas dogs with IMHA had significantly higher percentages of Ig(+) RBC than dogs with all other diseases. Dogs with IMHA, infectious diseases, and immune-mediated thrombocytopenia were significantly more likely to have anti-RBC antibodies than dogs with other medical or surgical diseases. Anemic dogs with immune-mediated diseases and infectious diseases were at the highest risk for the development of anti-RBC antibodies, and flow cytometry for the detection of IgG on RBC was highly sensitive and specific for the diagnosis of IMHA.

P, p′-DDE depresses the immune competence of chinook salmon ( Oncorhynchus tshawytscha) leukocytes

p, p′-DDE, the main metabolite of DDT, is still detected in aquatic environments throughout the world. Here, the effects and mechanisms by which p, p′-DDE exposure might affect the immune system of chinook salmon ( Oncorhynchus tshawytscha) was studied. Isolated salmon splenic and pronephric leukocytes were incubated with different concentrations of p, p′-DDE, and cell viability, induction of apoptosis, and mitogenic responses were measured by flow cytometry and Alamar Blue assay. p, p′-DDE significantly reduced cell viability and proliferation and increased apoptosis. The effect of p, p′-DDE on pronephric leukocytes was more severe than on splenic leukocytes, likely because pronephric leukocytes had a higher proportion of granulocytes, cells that appear more sensitive to p, p′-DDE. The effect of p, p′-DDE on leukocytes appeared to vary between developmental stages or seasonal differences. The mitogenic response of leukocytes of chinook salmon exposed to p, p′-DDE in vivo exhibited a biphasic dose–response relationship. Only leukocytes isolated from salmon treated with 59 ppm p, p′-DDE had a significantly lower percentage of Ig+ blasting cells than controls, although the response was biphasic. These results support the theory that exposure to chemical contaminants could lead to an increase in disease susceptibility and mortality of fish due to immune suppression.

Thalidomide Stimulates Splenic IgM Antibody Response and Cytotoxic T Lymphocyte Activity and Alters Leukocyte Subpopulation Numbers in Female B6C3F1 Mice

Thalidomide has been shown to have antiinflammatory and, more recently, immunomodulating properties, which are beneficial for the treatment of an ever-increasing list of immune related diseases. Although considerable knowledge regarding thalidomide's antiinflammatory properties has been acquired, relatively little is known about its immunomodulating properties in vivo. In this paper, a panel of immune assays was used to evaluate immunomodulation in female B6C3F1 mice treated intraperitoneally for 28 days with thalidomide (30, 100, or 150 mg/kg/day). Spleen antibody forming cell response was significantly enhanced by 37% in mice treated with 150 mg/kg/day, despite an 8% decrease in the percentage of Ig+ B cells. A significant stimulatory trend was observed for the cytotoxic T cell response across thalidomide treatment groups. An evaluation of the spleen leukocyte subpopulations revealed a 23% increase in the absolute number of CD8+ T cells in the 150 mg/kg treatment group and a 9 and 11% decrease in the absolute number of NK cells in both the 100 and 150 mg/kg thalidomide treatment groups, respectively. These findings demonstrate that, in addition to modulating spleen leukocyte numbers, thalidomide also stimulates murine humoral and cellular immune responses in vivo.

Lipopolysaccharide induces apoptotic cell death of B memory cells and regulates B cell memory in antigen-nonspecific manner

Lipopolysaccharide (LPS) was administered into sheep red blood cells (SRBC)-primed mice, and the effect of LPS on SRBC-specific memory cells was investigated. Spleen cells from SRBC-primed mice which were injected with LPS exhibited much lower in vitro secondary plaque-forming cells (PFC) responses to SRBC than those from untreated SRBC-primed mice. The in vitro anti-SRBC response of the spleen cells to LPS was also reduced. The combination experiments of B cells and T cells from SRBC-primed mice which were injected with or without LPS demonstrated that the reduction of immune responses to SRBC after administration of LPS was caused by the defect of SRBC-specific B memory cells, but not T memory cells. B cell type rosette-forming cells (RFC) for SRBC markedly decreased after injection of LPS, while PFC as antibody-forming cells did not increase subsequently. Therefore, the reduction of RFC was not due to their differentiation into PFC. The lymphoid follicles in the spleens from mice injected with LPS were stained positively by in situ nick end labeling specific for fragmented DNA. A large percentage of Ig + spleen cells from SRBC-primed mice which were injected with LPS was also stained positively. The injection of glucocorticoids into SRBC-primed mice induced similar reduction of B memory cells. It was suggested that LPS might induce apoptosis of B memory cells and regulate B cell memory in antigen-nonspecific manner.

Lipopolysaccharide induces apoptotic cell death of B memory cells and regulates B cell memory in antigen-nonspecific manner.

Lipopolysaccharide (LPS) was administered into sheep red blood cells (SRBC)-primed mice, and the effect of LPS on SRBC-specific memory cells was investigated. Spleen cells from SRBC-primed mice which were injected with LPS exhibited much lower in vitro secondary plaque-forming cells (PFC) responses to SRBC than those from untreated SRBC-primed mice. The in vitro anti-SRBC response of the spleen cells to LPS was also reduced. The combination experiments of B cells and T cells from SRBC-primed mice which were injected with or without LPS demonstrated that the reduction of immune responses to SRBC after administration of LPS was caused by the defect of SRBC-specific B memory cells, but not T memory cells. B cell type rosette-forming cells (RFC) for SRBC markedly decreased after injection of LPS, while PFC as antibody-forming cells did not increase subsequently. Therefore, the reduction of RFC was not due to their differentiation into PFC. The lymphoid follicles in the spleens from mice injected with LPS were stained positively by in situ nick end labeling specific for fragmented DNA. A large percentage of Ig+ spleen cells from SRBC-primed mice which were injected with LPS was also stained positively. The injection of glucocorticoids into SRBC-primed mice induced similar reduction of B memory cells. It was suggested that LPS might induce apoptosis of B memory cells and regulate B cell memory in antigen-nonspecific manner.

Murine retroviral disease-enhancing effects of a pyrimidinone immunomodulator

(B10.A × A/WySn)F 1 mice, infected with the Friend virus (FV) complex, were used as a predictive therapeutic model for AIDS. These infected mice exhibit many of the viral and immunologic manifestations of AIDS. Bropirimine (2-amino-5-bromo-6-phenyl-4[ 3H]pyrimidinone, ABPP) is an immunomodulating compound which has been shown to inhibit other viral infections. Oral (per os treatment) dosages of ABPP ranging from 50 to 400 mg/kg/day for 3 days resulted in increased numbers of infectious centers in the infected mice and increased splenomegaly and percentage of Ig+ (B cells) in spleens of infected and uninfected mice. Decreased percentages of total Thy-1.2+ (total T) cells and L3T4+ (T-helper) cells were seen in both uninfected and infected mice and a slightly decreased percentage of Ly-2+ (T-suppressor/cytotoxic) cells was observed in spleens of the infected mice. No effect on Ly2+ cells in spleens of uninfected mice was found. Intraperitoneal injection, single or multiple, of 20–200 mg/kg ABPP prior to FV injection resulted in increased spleen weights but had no effect on numbers of infectious centers in the spleens or on FV antibody titers in the plasma. Intraperitoneal treatment of uninfected mice with ABPP resulted in slight or no changes in percentages of Thy-1.2+, L3T4+ and Ly-2+ cells. Mice receiving multiple exposures of ABPP had an increase in percentage of splenic B cells and a depressed response to the T cell mitogen PHA. Treatment with ABPP induced the production of interferon (IFN); however, a state of hyporesponsive IFN production was seen following multiple administrations of ABPP. These data suggest that the immunomodulator ABPP may have an enhancing effect on this retroviral disease.

Trypanosoma cruzi: Flow cytometric analysis of lymphocyte subsets in susceptible and protected C3H/He mice

Inbred strains of mice vary widely in their ability to survive infection with Trypanosoma cruzi. C3H/He mice are highly susceptible to infection with the Brazil strain T. cruzi, but can be protected by immunization with avirulent Corpus Christi strain parasites. We have examined, during the course of infection, the changes in lymphocyte populations in C3H/He mice that were infected but protected by immunization, infected but not immunized, immunized but not infected, and normal age-matched controls. Immunization- and/or infection-induced changes in lymphocyte populations in lymph nodes were unremarkable except for an increase in the percentage of Ig+ cells. Conversely, in the spleen the percentages of mu+ cells decreased and T cells increased in all manipulated animals. The increase in splenic T cell subsets in immunized only controls occurred simultaneously and thus the CD4:CD8 ratio remained similar to that of normal animals (approximately 2.2). Twenty days after infection, mice that were infected but not immunized (and thus would be expected to die 4–8 days later) showed a dramatic increase in the percentage of CD8+ cells which resulted in a decline in the CD4:CD8 ratio to 0.85. Mice protected by immunization had a CD4:CD8 ratio of 1.7 at this critical time point, which did, however, decline to 1.0 by Day 60. The percentages of all cell phenotypes examined in all mice had returned to normal levels 155 days after infection. These data suggest that alterations in the splenic CD4:CD8 ratio may be important in determining whether or not an animal can survive infection with the Brazil strain of T. cruzi.

B-lymphocyte populations in Xenopus laevis

Two-color immunofluorescence technique was used to show the development and distribution of surface μ − cytoplasmic μ + (sμ −cμ +) pre-B, sμ + B- and sμ + cIg + plasma cells in metamorphic, postmetamorphic, and adult Xenopus. Generation of pre-B cells was evident in hematopoietic liver and spleen, but not in bone marrow, thymus, and duodenal mucosa. Surface immunoglobulin positive small lymphocytes were the most abundant in the spleen while plasma cells were detected in the thymus, duodenal mucosa, spleen, and liver. We had shown previously the appearance of sμ −cμ + pre-B cells in the liver of Xenopus larvae at developmental stage 46 and later at stage 49 in the spleen. The frequency of pre-B cells dropped to zero at stage 58, the climax of metamorphosis. Pre-B cells start to reappear slowly as a second wave, at stage 60 through early postmetamorphic life in the liver and spleen. The percentage of surface Ig + (sIg +) cells in the spleen of developing animals from stage 60 onward is comparable to that observed in adult life. In adult animals, the periphery of the liver continues to be active in hematopoiesis and contains some IgM producing plasma cells and rare sIg + small lymphocytes while the pre-B cells are almost nonexistent in this region. The spleen, which is also active in some hematopoiesis, constitutes the main site of B-cell differentiation. Three ontogenic stages of pre-B, B-, and plasma cells are present in this organ. Pre-B and plasma cells are of low density and heterogeneous in size while small sIg + B lymphocytes are of high density and much more homogeneous in size. The bone marrow in these lower anuran amphibia is rudimentary and is not a lymphopoietic tissue; in adult animals it is active only in differentiation of neutrophilic granulocytes.

The value of immunocytochemical staining of lymph node aspirates in diagnostic cytology

This study investigates the applicability of immunocytochemical techniques towards improving the cytological diagnosis of lymph node disorders. Cytocentrifuge preparations of fine needle aspirates were examined using an indirect immunoperoxidase method and the alkaline phosphatase-antialkaline phosphatase method. 36 reactive lymph nodes were evaluated. 23 patients showed T cell predominance as assessed by the presence of CD3+ cells. 13 patients showed an excess of CD24+ cells over CD3+ cells. In all patients the B cell population showed no light chain class restriction. 48 aspirates from patients with B-non-Hodgkin's lymphoma of low malignancy were investigated. The majority of the cells in each of these cases expressed CD24 and 47 cases were monoclonal with respect to their light chain determinants. In 37/48 cases the antibody OKT9 reacted with less than 15% of cells. 18 aspirates were obtained from patients with B-non-Hodgkin's lymphoma of high malignancy. 17 patients showed light chain class restriction and a high percentage of CD24+ (greater than 80%) and OKT9+ (greater than 40%) cells. 8 malignancies were considered to be of T-cell origin. A low percentage (less than 15%) of Ig+CD24+ cells with a high number of CD3+ and/or CD4+ cells suggests a T-cell lymphoma. The majority of neoplastic cells in peripheral T-cell lymphomas (excluding mycosis fungoides) expressed OKT9 and CD3 expression was found to be variable. In 15 cases of Hodgkin's disease, there were 11 correct cytologic diagnoses. A significant number of BerH2 (CD30)+ cells having the morphology of Sternberg-Reed cells supports this diagnosis. 25 aspirates were obtained from patients with metastatic malignant tumours. Marker studies in eight cases helped in distinguishing metastatic malignant tumours from malignant lymphomas. Our findings indicate that the immunocytochemical technique is applicable to cytological material and that the simplicity of the procedure merits application to routine diagnostic cytology.

Antibodies to Shared Idiotypes as Agents for Analysis and Therapy for Human B Cell Tumors

Abstract Monoclonal anti-idiotypic antibodies generated against idiotypic immunoglobulin (Ig) of neoplastic B lymphocytes can be selected from growing hybridoma clones by their ability to recognize idiotypic but not normal IgM. This group of antibodies can be subdivided into those that bind to the target tumor cells in the presence of normal human serum (approximately 85% of the clones) and those in which binding is inhibited by serum (approximately 15%). The former appear to be specific for private idiotypic determinants whereas the latter recognize cross-reacting idiotypic determinants. Such cross-reactivity is reflected both in recognition of a small percentage of normal Ig and also in binding to other lymphomas. The anti-idiotypes specific for private determinants can be used for therapy, with only idiotypic Ig secreted by tumor cells able to block its access to cells. The cross- reacting anti-idiotypes will face in addition the barrier of the proportion of normal Ig with which it reacts. The attraction of using a single monoclonal reagent for more than one patient has led us to develop an assay that measures the level of such blocking and to propose that those recognizing less than 30 micrograms/mL of normal Ig could be placed in a panel for possible therapy for several patients; less restriction need apply to antibodies for monitoring tumor progress. The assay is described, and examples of such antibodies raised against lymphoma cells from two patients are given together with comparisons with them of anti-idiotypes specific for private determinants.

Antibodies to shared idiotypes as agents for analysis and therapy for human B cell tumors

Monoclonal anti-idiotypic antibodies generated against idiotypic immunoglobulin (Ig) of neoplastic B lymphocytes can be selected from growing hybridoma clones by their ability to recognize idiotypic but not normal IgM. This group of antibodies can be subdivided into those that bind to the target tumor cells in the presence of normal human serum (approximately 85% of the clones) and those in which binding is inhibited by serum (approximately 15%). The former appear to be specific for private idiotypic determinants whereas the latter recognize cross-reacting idiotypic determinants. Such cross-reactivity is reflected both in recognition of a small percentage of normal Ig and also in binding to other lymphomas. The anti-idiotypes specific for private determinants can be used for therapy, with only idiotypic Ig secreted by tumor cells able to block its access to cells. The cross-reacting anti-idiotypes will face in addition the barrier of the proportion of normal Ig with which it reacts. The attraction of using a single monoclonal reagent for more than one patient has led us to develop an assay that measures the level of such blocking and to propose that those recognizing less than 30 micrograms/mL of normal Ig could be placed in a panel for possible therapy for several patients; less restriction need apply to antibodies for monitoring tumor progress. The assay is described, and examples of such antibodies raised against lymphoma cells from two patients are given together with comparisons with them of anti-idiotypes specific for private determinants.

Circulating T- and B-Cell Abnormalities in Cutaneous Lupus Erythematosus

Seven patients with subacute cutaneous lupus erythematosus (SCLE), 11 patients with discoid lupus erythematosus (DLE), and 17 age-, sex-, and race-matched controls were examined for the number of circulating peripheral blood T and B cells, immunoglobulin (Ig) synthesizing cells, and Ig secreting cells. A significant alteration in T-cell subsets was detected only in SCLE patients who manifested a decreased number of OKT8 cells. Circulating B cells were significantly increased only in the SCLE patients. The percentage of Ig synthesizing and secreting cells was significantly increased in both the DLE and the SCLE groups. The somewhat unexpected increase in Ig synthesizing and secreting cells in the DLE patients could not be accounted for by antimalarial treatment or the concurrence of the HLA-DR3 phenotype. There was, however, a weak but significant correlation between the degree of B-cell activation in the DLE patients and the number of American Rheumatism Association criteria for the classification of systemic lupus erythematosus (SLE) possessed by these patients. These data demonstrate that abnormalities in B-cell function similar to those seen in SLE can also be found in a group of lupus erythematosus patients whose clinical disease expression is limited predominantly to the skin.

Effect of β-Lactoglobulin Variant and Environmental Factors on Variation in the Detailed Composition of Bovine Milk Serum Proteins

Between November 1979 and November 1981, 17,086 test-day milk samples were collected from individual Holstein cows in 62 Quebec herds. Samples were analyzed for protein, fat, casein, serum protein, somatic cell count, and the relative percentages of β-lactoglobulin, α-lactalbumin, bovine serum albumin, and the immunoglobulins. Cows included in the study were phenotyped with respect to β-lactoglobulin. Unadjusted means±standard error for the relative percentages of β-lactoglobulin, α-lactalbumin, bovine serum albumin, and immunoglobulins were 64.80±.07%, 21.54±.05%, 6.51±.02%, and 7.15±.04%. Least-square analyses showed that month of test, stage of lactation, age of cow, somatic cell count, and phenotype of the cow for β-lactoglobulin had significant effects on the relative percentages of β-lactoglobulin, α-lactalbumin, bovine serum albumin, and immunoglobulins. Test-day milk yield, fat percent, protein percent, casein percent, casein number, and serum protein percent, when included in a statistical model as covariates, had a significant effect on the relative percentage of Ig. Relative proportion of β-lactoglobulin and α-lactalbuminim were not significantly affected by serum protein and total protein contents. For bovine serum albumin, only the covariates fat percent and serum protein percent were not significant.

Properties and kinetics of the B lymphocyte population of rats during development

Cells carrying surface immunoglobulins (Ig+ cells) detected by the indirect immunofluorescence method, and cells forming rosettes with sheep's red blood cells (SRBC) with antibodies adsorbed on their surface and with complement (RFC), were found in the liver and spleen of rat fetuses at the 15th and 20th days of development. The relative percentage of Ig+ cells and RFC in the liver remained low and about the same level in rats on different days of postnatal development. In the spleen and bone marrow the number of Ig+ lymphocytes and RFC increased during the first month of the rat's life, to reach a maximum in animals aged 30 days, and fell sharply in old rats. No Ig+ cells or RFC were present in the thymus or they were found in very small numbers at certain times of investigation. Ig+ lymphocytes with “caps” of fluorescence on their surface appeared in the spleen and bone marrow on the fifth and 10th days of life of the rat and their number rose considerably by the age of 30 days and in adult rats. No such cells were present in the lymphoid organs of old (40 months) animals.

Immunoglobulin-positive cells from the gland of harder and bone marrow of the chicken

Cells were collected from the gland of Harder (GH) and bone marrow (BM) of 14-, 21- and 32-week-old birds and were incubated with an 125I-labeled rabbit anti-chicken Ig (IgG and IgM) serum. At 14 weeks of age the percentage of Ig + small lymphocytes (SL) in the GH and BM was similar. However, by 21 weeks of age Ig + SL in BM had increased to approximately 19% of total lymphocytes while the Ig + SL in the GH represented less than 1.7% of the lymphocyte pool. A marked drop in the number of Ig + SL in BM occurred by 32 weeks of age. These data suggest that either the BM may be dependent on the bursa for maintenance of its Ig + SL or it is unable to produce in situ or maintain Ig + SL with age. In the GH the predominant cell was the plasma cell (PC). Labeled PC (> 20 grains) exceeded 80% of the total PC pool in the GH. These data contrast with the apparent deficiency of Ig receptors on murine PC. The maintenance of a large number of PC in the GH without the presence of Ig + SL illustrates the uniqueness of this gland.

Splenic Modifications Induced by Cyclophosphamide in C3H/He, Nude, and “B”-Mice

The spleen cell population of adult C3H/He mice injected with a single sublethal dose of cyclophosphamide (CY) has been analyzed. An initial phase of spleen atrophy is followed by a considerable hypertrophy, and a progressive return to normal. During the phase of spleen atrophy, both B and T cell compartments are depleted, as estimated by the percentages of cells killed by anti-Thy 1-2 and anti-Ig antisera plus complement. During the stage of regeneration, the percentage of Ig + cells increases rapidly, and at the peak of splenomegaly, the percentage of Ig + cells is high whereas almost no Thy 1-2 + cells are detectable. Progresively, the spleen cell content returns to the original values. In thymo-deprived mice (nude mice and B mice) the percentage of null cells increases during the stage of regeneration, and B mice develop a large number of Ig +-bearing cells. Histologic examination shows that follicles (B-dependent areas) disappear 1 to 2 days before periarteriolar sheaths (T-dependent areas). At the peak of splenomegaly the architecture of the spleen is destroyed, and the interstitial tissue is composed of a dense and uniform layer of lymphoid cells. Progressively, the architecture returns to normal. In nude mice, the disappearance of follicles, and the appearance of a homogenous layer of lymphocytes has been observed. When analyzed for their pattern of electrophoretic mobilities (E.M.), spleen cells from untreated mice reveal two peaks of E.M. 0.80 and 1.15 micron x s-1 x V-1 x cm-1. After CY treatment, during the step of splenic hypertrophy, these two peaks disappear, and a single peak of intermediate mobility appears. In T-deprived mice, a single peak of the same mobility is detected at this stage. The nature and origin of cells which appear during the phase of regeneration are unclear, but their appearance in T-deprived mice argues against thymo dependence. These spleen cells have the ability to suppress the response of normal spleen lymphocytes to T and B cell mitogens.