The development of the lymphoid organs of flounder, Paralichthys olivaceus, from hatching to 13 months

The growth of the lymphoid organs, such as head kidney, spleen and thymus were studied in flounder, Paralichthys olivaceus Temminck & Schlegel, from hatching to 13 months of age. Except for the thymus, all organs grew as the fish grew. By 2 months of age the lymphoid organs attained their maximum relative weight. The organ weight showed a closer correlation to body weight than they did to age. The total number of leucocytes in the lymphoid organs increased with age, but the number per milligram of lymphoid organ remained constant. A micro and ultrastructural study of the lymphoid organs showed that the full development of the lymphoid organs was not achieved until the juvenile stage. The spleen and head kidney had mixed populations of "red" and "white" cells. The head kidney was more lymphoid than the spleen. The thymus involuted quickly during the first 6 months. The blood components had no obvious relationship with age or season during the period studied.     

Specificity of the effect of growth hormone on DNA concentration in the nuclei of the lymphoid cells of hypophysectomized rats]

The effect of growth hormone on the DNA content in the nuclei of the thymus, spleen and the lymph node lymphocytes was studied by means of cytophotometry. In hypophysectomized rats the growth hormone increased the DNA content in the nuclei of the middle lymphocytes of these organs without altering its amount in the small lymphocytes. Thymus lymphocytes were the most sensitive to the hormone action. The DNA content in the nuclei of these cells increased as soon as one hour after the administration of the hormone; in 4 hours it reached the maximum. Other hormones with an anabolic effect (insulin, thyroxin, testosterone), induced no elevation of DNA in the thymocyte nuclei at that period of time. A conclusion was drawn on the high tropicity of the growth hormone to the cells of the lymphoid organs and particularly to the thymocytes (middle lymphocytes of the thymus).     

Lymphoid organ weights and organ:body weight ratios of growing beagles

Although dogs, especially beagles, are used extensively in biological and clinical investigations, the literature dealing with normal biological measurements of their lymphoid organs is scanty. This study was undertaken to provide the information on the weight of lymphoid organs of beagles. The thymus, spleen, and prescapular, popliteal, and mesenteric lymph nodes of 95 normal beagle dogs, from one day to 11 months of age, were weighed and compared with body weights. The weight of the thymus and spleen increased drastically at and after 2 months of age, although the organ:body weight ratios remained the same at 2 months of age and decreased afterward. Similar increases in the weight of the mesenteric lymph node complex, but with an increase in the organ:body weight ratio, occurred also at and after 2 months of age, reflecting the importance of the gut-associated lymphoid organs after weaning. The increases in the size of the cutaneous nodes, prescapular and popliteal, were less pronounced and their organ:body weight ratios remained the same from birth through 11 months of age.     

Biosynthetic human growth hormone: effects on growth of Snell dwarf mice

Bacterially synthesized human growth hormone (bhGH) administered to Snell dwarf mice during 4 weeks, induced an increase in body length and weight to a comparable degree as obtained with pituitary-derived human growth hormone (hGH). At a dose of 150 mU/day both bhGH and hGH induced a significant stimulation over saline-treated controls, of the weight of the submandibular salivary glands, the m. quadriceps femoris and gastrocnemius, the heart, liver, kidneys, thymus and spleen. The weight of the brain and the thickness of the skinfold were not influenced by either of the preparations used. When organ weights were expressed as a function of body weight, the contribution of the kidneys to body weight was significantly higher with hGH than with bhGH. The other organs studied did not show differences. As a biochemical parameter of cartilage growth, the sulfate incorporation into costal and epiphyseal cartilage in vitro was measured, and it was found to be stimulated by both hormones after short-term treatment. Thus bacterially synthesized hGH behaves identically to pituitary-derived hGH with respect to body length, sulfate incorporation into costal and epiphyseal cartilage, body weight and organ growth of Snell dwarf mice, with one exception: increase of weight of the kidneys, as a function of body weight, was more pronounced after treatment with hGH than with bhGH.     

Development of Immunodeficiency of Pituitary Dwarf Mice

Autosomal recessive pituitary dwarf mutants of the Snell-Baggand Ames mouse strains develop severe immunodeficiency of thethymus-dependent (T cell) system which frequently leads to afatal wasting syndrome. The ontogenetic development of the Tcell system is already subnormal soon after birth as evidencedby diminished responsiveness of thymus and spleen cells to phytohemagglutininand concanavalin A. The immunodeficiency of the dwarf mouseis a consequence of defective pituitary influences which willcause (i) an inadequate production of immunocompetent cellsdue to a central developmental defect primarily affecting thethymus, and (ii) the inability of immunocompetent cells to undergoa rapid and efficient antigen-induced proliferation and differentiationinto antibody-forming cells. The lack of epinephrine-inducedstimulation of adenylate cyclase activity in dwarf spleen andthymus cells suggests that the impaired lymphoid cell proliferationin dwarf mice may be due to inadequate stimulation of cyclicAMP production.     

Effect of electric field during incubation of eggs on the immune responses of hatched chickens

The effects of electric field (EF) during incubation of eggs on the immunocompetence of chickens were investigated over a 42-day experimental period. Eggs from a meat-type breeder flock were incubated under EF of 30 kV/m, 60 Hz during the first 18 days of incubation as compared with the control incubation (C). Chickens from the two incubation treatments were fed ad libitum and their immune system were monitored. Measurements were made of body weight (BW), and lymphoid organs weight (thymus, spleen, and bursa of Fabricius (BOF)) of birds at 21 and 42 days of age. Immune systems of birds were tested for specific antibody responses to sheep red blood cell (SRBC) and Newcastle disease vaccine (NDV), in vivo T-lymphocyte proliferation responses to phytohemagglutinin (PHA), and in vitro to concanavalin A (Con-A). EF incubation of eggs did not significantly (P > 0.05) influence BW of bird, absolute weight of lymphoid organs and weight of thymus, and BOF as a percentage of BW of bird (% BW) at 21 and 42 days of age, humoral immune responses as measured by antibody responses to SRBC and NDV, and cell-mediated immune responses as measured by T-lymphocyte proliferation responses to PHA, and Con-A of birds when compared with those of the C treatment. EF incubation of eggs significantly (P < 0.05) increased spleen weight as a % BW at 21 and 42 days of age when compared with those incubated under the C treatment. Birds at 42 days of age had significantly (P < 0.01) higher BW, lymphoid organ weight, and weight of BOF as a % BW, and lower spleen weight as a % BW when compared with those of 21 days of age. It is concluded that the incubation of eggs under EF of 30 kV/m, 60 Hz increased spleen weight as a % BW, without altering cell-mediated and humoral immune responses and, consequently, immunocompetence of meat chickens during the rearing period of 42 days.     

Immunologic and hematologic effects of neuroendocrine hormones. Studies on DW/J dwarf mice.

DW/J dwarf mice lack acidophilic anterior pituitary cells and are deficient in growth hormone and other neuroendocrine mediators. These mice were examined to determine the effects of these deficiencies on hematopoietic and immune system development. Previous studies have suggested that these mice had immunologic defects primarily involving T cell development. However, we have found that these mice exhibit decreased peripheral blood cell counts affecting all lineages (erythrocytic, leukocytic, and platelets). Examination of lymphoid tissues of dwarf mice indicated that their spleens were hypoplastic. Treatment of these mice with recombinant human growth hormone resulted in a significant improvement of peripheral blood counts and spleen cell number. Analysis of the bone marrow indicated a profound deficiency of B cell progenitors in the dwarf mice. However, in untreated dwarf mice, mature B cells and T cells were observed in the spleens. Although treatment with recombinant human growth hormone could correct the hematopoietic deficiencies in these mice, it did not restore the B cell progenitor populations, suggesting that an absence of growth hormone is not solely responsible for this deficiency. Thus, these mice display significant myeloid and lymphoid deficiencies that have been previously undetected.     

Immunologic disparity in the hypopituitary dwarf mouse.

The Snell-Bagg hypopituitary dwarf mouse has been shown to be deficient in growth hormone, thyroxine, and prolactin. There are reports indicating that in addition to these neuroendocrine abnormalities, development of immune competence is also severely impaired in these animals. However, other studies indicate that the immunologic potential of these mice does not differ from their heterozygous littermate controls. Our data show that dwarf mice weaned at 21 days of age and killed at that time, or 7 days later, have reduced numbers of cells in both the spleen and thymus and the mitogen responsiveness of these cells is impaired. However, if mice weaned on day 21 are analyzed at 32 days of age or the mice are weaned at day 30 and analyzed 7 days later the ability to respond to mitogenic stimulation does not differ from controls. Further experiments show that dwarf mice weaned at 30 days of age have a normal complement of V-beta TCR as evidenced by immunofluorescence analysis as well as a primary antibody response to SRBC equivalent to that observed in normal littermates. Immunofluorescence analysis of CD4 and CD8 expression on thymocytes obtained from dwarf mice shows a distinct pattern dependent on the time of weaning and time of analysis. Initial analysis of thymocytes from dwarf mice weaned and killed at 21 days of age do not differ from controls. However, cells from dwarf mice weaned on day 21 and killed on day 28 are markedly different with a loss of immature CD4+/CD8+ cells and a corresponding increase in CD4+ and CD8+ mature thymocytes. In contrast, the phenotype of thymocytes obtained from dwarf mice weaned at 30 days of age and killed on day 37 did not differ from normal littermates. Collectively these studies indicate that hypopituitary dwarf mice lag behind their heterozygous littermates with respect to development of immunocompetence but normal immune responsiveness does develop by 32 days of age when the mice are weaned on day 21.     

Studies on the resistance to tolerance induction against human IgG in DDD mice. I. Organ differences of tolerogen susceptibility and cellular sites responsible for the resistance.

Cellular sites of the tolerogen resistance in DDD mice against human IgG (HGG) were examined by reconstitution experiments in which cells of various lymphoid organs from tolerized mice were transferred into lethally irradiated syngeneic recipients with or without the supplement of an excess number of untreated T or B cells. It was shown that T cells but not B cells in the spleen and bone marrow-locating B cells were tolerogen resistant. Kinetic profiles of tolerance induction were compared among thymus, lymph node, and spleen T cells. Thymus cells fall into unresponsive state as early as 2 days after the tolerogen (tHGG) injection when only partial tolerance was observed in lymph node T cells. By 1 week of tolerogen treatment, the tolerant state was completed in both thymus cells and lymph node T cells, while spleen T cells showed marked resistance. Tolerance induced in thymus cells and spleen T cells was of relatively short duration and responsiveness was completely recovered by 5 weeks after the injection of tHGG. At this time lymph node T cells still showed hyporesponsiveness. The differences in tolerance inducibility were also shown among different lymphoid organs in tolerogen dose response. Lymph node T cells were very sensitive to tolerance induction, giving no response even by the injection of 0.01 mg of tHGG. Thymus cells were much less sensitive with the gradual loss of responsiveness by increasing the amount of tHGG. In contrast, spleen T cells showed gradual resistance with increasing amount of tHGG, indicating that some positive response was evoked in spleen T cells by a relatively high dose of tHGG. These results seem to suggest that the tolerogen resistance of spleen T cells may be due to their capability of showing positive response against the tolerogenic material. This was also suggested by the fact that the treatment with cyclophosphamide following the tolerogen injection diminished completely the responsiveness against the subsequent challenge immunization.     

Biochemical changes in progressive muscular dystrophy. XII. Cyclic nucleotides in lymphoid and nonlymphoid organs of dystrophic mice

Concentrations of cAMP and cGMP were measured (per milligram DNA) in the lymphoid (thymus, spleen) and nonlymphoid organs (liver, brain, kidney, lungs, heart, pancreas, skeletal muscle, lens) of normal (+/+) and dystrophic (dy/dy) 129 ReJ mice aged 30, 60, and 90 days. The cAMP concentrations in the thymus did not reveal any significant differences at 30 and 60 days of dystrophy, but were considerably higher (2-fold) at 90 days. cGMP concentrations were decreased in the thymus at 30 days (0.20-fold) and markedly elevated at 60 (2-fold) and 90 days (3-fold) of the disease. The [cAMP]/[cGMP] ratio was increased (1.30-fold) at 30 days of dystrophy, and this was followed by a sharp decline at 60 days (2-fold), with a lesser decrease at 90 days (0.34-fold). In the spleen, the cAMP concentrations were augmented significantly in all stages of dystrophy (1.5- to 2.6-fold). cGMP (per milligram DNA) did not show any significant variation at 30 and 60 days of the disease but was increased (3-fold) at 90 days. The [cAMP]/[cGMP] ratio, which was enhanced in the spleen at 30 (2-fold) and 60 days (1.5-fold), demonstrated no change at 90 days of dystrophy. These results indicated significant differences in the concentration of cyclic nucleotides and their ratios in the thymus and spleen of 129 ReJ dy/dy mice. The modifications were not limited to lymphoid organs alone, having been noted in the nonlymphoid organs as well. These changes could, in turn, influence immune responsiveness and could cause immunodepression in dystrophic mice.     

Longitudinal assessment of immunologic abnormalities of mice with the autosomal recessive mutation, "wasted"

Mice homozygous for the autosomal recessive mutation wasted (wst/wst) undergo a progressive wasting beginning at the third week of postnatal life, when body weight declines in the mutants. The wst/wst mice do not survive past 30 days of age. The present report describes histologic and functional abnormalities in a longitudinal analysis (17 to 29 days postpartum) of wst/wst mice. In addition to a marked age-dependent decline in wst/wst body weight as well as spleen and thymus wet weight to body weight ratios, we have observed a significant decline in spleen and thymus cell number in these organs, compared with phenotypically normal (+/+ or +/wst) littermates. Histologic analysis of the wst/wst thymus revealed marked cortical pyknosis at 23 days of age and significant cortical depletion by 26 days postpartum. The wst/wst spleen at 23 days of age and later was characterized by a marked reduction in the content of red pulp. Lymphoproliferative responsiveness to Con A was markedly altered in the wst/wst thymus and spleen, in an age-dependent fashion, compared with normal littermates. The wst/wst spleen LPS responsiveness was also markedly altered in an age-dependent fashion. Hypotheses are presented concerning the possible site(s) of gene action in the wst/wst mutant which may mediate the observed morphologic and functional abnormalities.     

Effect of somatotropic hormone on autoimmune responses induced in mice of different genotypes by syngenous heated erythrocytes]

A single administration of 1 X 10(9) heated erythrocytes to C57BL and BALB/c mice caused on the 13th day the appearance of antierythrocytic autoantibodies, an increase in the weight of the lymphoid organs, and lymphoreticular hyperplasia. These changes were more pronounced in BALB/c mice. During the development of autoimmune reactions the changes in the number of E- and EAC-rosette-forming cells in the thymus and spleen and in the immune response to the sheep erythrocyte immunization and E. coli endotoxin were revealed; distinct strain differences were observed. Daily somatotropic hormone administration (5 mg/kg of body weight) for 10 days decreased the degree of the autoimmune reactions development in mice of both strains. Its action was more expressed in BALB/c mice.     

Effect of extremely high frequency electromagnetic radiation of low intensity on parameters of humoral immunity in healthy mice

The modification of indices of the humoral immune response to thymus-dependent antigen (sheep erythrocytes) after a whole-body exposure of healthy mice to low-intensity extremely-high-frequency electromagnetic radiation was studied. Male NMRI mice were exposed in the far-field zone of horn antenna at a frequency of 42.0 GHz and energy flux density of 0.15 mW/cm2 under different regimes: once for 20 min, for 20 min daily during 5 and 20 successive days before immunization, and for 20 min daily during 5 successive days after immunization throughout the development of the humoral immune response. The intensity of the humoral immune response was estimated on day 5 after immunization by the number of antibody-forming cells of the spleen and antibody titers. Changes in cellularity of the spleen, thymus and red bone marrow were also assessed. The indices of humoral immunity and cellularity of lymphoid organs changed insignificantly after acute exposure and series of 5 exposures before and after immunization of the animals. However, after repeated exposures for 20 days before immunization, a statistically significant reduction of thymic cellularity by 17.5% (p < 0.05) and a decrease in cellularity of the spleen by 14.5% (p < 0.05) were revealed. The results show that low-intensity extremely-high-frequency electromagnetic radiation with the frequency and energy flux density used does not influence the humoral immune response intensity in healthy mice but influences immunogenesis under multiple repeated exposures.     

Growth-stimulating effects of somatomedin-/insulin-like peptides in Snell dwarf mice

The effect of the somatomedin-/insulin-like growth factors IGF-I, IGF-II and N2, as well as of semi-purified SM fractions separated by isoelectric focusing derived from human Cohn IV on different growth parameters, have been studied in the Snell dwarf mouse. HPLC-pure IGF-II, N2 and IGF-I stimulate to a similar extent the sulphate incorporation into costal cartilage, the osteochondral junction and epiphyseal cartilage. After 4 weeks of treatment, increase in body length and weight as well as the weights of several organs is obtained with SM fractions, focusing at acid and neutral pH, and containing mainly IGF-II- and less than 5% IGF-I-like peptides. Fractions containing mainly IGF-I-like peptides and focusing at basic pH at the dosage used seem to be less stimulatory on most of these parameters. The rump/tail ratio and weight/length ratio is comparable to that obtained after treatment with human growth hormone (hGH). hGH induced a significant stimulation of the weight of the liver, kidneys, heart, thymus and spleen. The acid and neutral SM fractions induced growth of the liver, kidneys and spleen. The basic fractions only produced a significant weight gain in kidneys and spleen. The skinfold thickness is stimulated by the SM preparations and only slightly by hGH.     

Effect of highly purified thymus factor on the cellular and humoral indices of immunity in thymectomized mice]

Effect of homogeneous polypeptide thymus factor of mol weight about 5000 (thymarin-III) on cellular and humoral immune responses of thymectomized adult CBA mice was studied. Thymectomy proved to greatly decrease the number of T-cells in the spleen. Accordingly, the capability of these mice to produce both IgM and IgG antibody-forming cells in response to the thymus-dependent antigen (sheep red blood cells) was significantly depressed. Subcutaneous injections of thymarin-III (1 microgram per g of body weight) for 7 days completely restored the T-cell spleen population and normalized the animals' immune response.     

Effect of beta-Carotene on the development of the solid Ehrlich tumor in mice

The effect of beta-Carotene on the development of the solid Ehrlich tumor in BALB/c mice was investigated. Male mice received orally, on alternate days, three different doses of beta-Carotene (1, 3.5 or 7 mg/100 g) or corn oil as the control. This protocol started 14 days before tumor inoculation (1.75 x 10(5) cells) into mouse footpad and lasted until 10 days after. The tumor growth was evaluated by daily measurement of the footpad thickness, and the tumor mass was evaluated morphometrically. The proliferation rate of tumor was investigated by counting PCNA (proliferating cell nuclear antigen) positive nuclei in the 10th day of the tumor development. Histopathological examination of the lymphoid tissue: thymus, spleen and popliteal lymph node were also performed. beta-Carotene treatment, at dose 3.5 mg/100 g, increased the tumor growth, proliferative rate and the relative weight of popliteal lymph nodes, showing up an adverse effect only when this intermediate dose was used. No effects were obtained when the smaller (1,0 mg/100 g) or the higher (7.0 mg/100 g) doses were used. These results suggest that depending on the dose, beta-Carotene may determine an undesirable effect upon the tumor growth. This should be taken into account in chemopreventive experiments and human applications.     

Effect of selenium and vitamin E dietary deficiencies on chick lymphoid organ development

Diets specifically deficient in selenium (Se) and/or vitamin E or adequate in both nutrients were fed to chicks from the time of hatching. Lymphoid organs (bursa, thymus, and in some instances, spleen) were collected from chicks 7-35 days of age. Growth of the chicks fed these diets was monitored over the experimental period as was lymphoid organ growth. The development of the primary lymphoid organs was further assessed by histological techniques and the organ contents of vitamin E (alpha-tocopherol) and Se were determined. Specific deficiencies of either Se or vitamin E were found to significantly impair bursal growth as did a combined deficiency. Thymic growth was impaired only by the combined deficiency diet. Severe histopathological changes in the bursa resulted from the combined deficiency and these were detectable by 10-14 days after hatching. These changes were characterized by a gradual degeneration of the epithelium and an accompanying depletion of lymphocytes. Similar changes, although slower to develop and less severe, were observed in the thymus as a result of the combined deficiency. When both serum and tissue levels of vitamin E and Se were monitored, it was observed that these were rapidly and independently depleted by the specific deficiency diets. These data suggest that the primary lymphoid organs are major targets of Se and vitamin E dietary deficiencies and provide a possible mechanism by which immune function may be impaired.     

Microscopic observations of skin and lymphoid organs in the hairless dog derived from the Mexican hairless

The skin and lymphoid organs of Mexican hairless dogs and their hairless offspring were examined histologically. The hairless dogs lacked most hairs except for sparse hairs on the head, tail and feet. The skin of newborn pups consisted of a thick epidermis with epidermal ingrowths forming the rudiments of hair follicles. In older dogs more than 2 months of age, however, the epidermis was thin and the ingrowths were few. Neither hair follicles nor skin glands were present. The hairy skin of the head and tail had hair follicles with sebaceous glands. Regarding the lymphoid organs, the newborn pups possessed a thymus like haired pups. But in the older dogs more than 2 months of age, the thymus was atrophied and the lymphocyte population was too sparse to demarcate the cortex and the medulla. Lymphocyte accumulation in older dogs was also poor in the spleen and mesenteric lymph nodes. The present findings indicate that the hairlessness of the Mexican hairless dogs and their descendants is accompanied by early atrophy of the thymus after birth, and is followed by poor accumulation of lymphocytes in the thymus-dependent area of the spleen and the mesenteric lymph nodes. The defect of the thymus in the hairless dog seems to be different from that in athymic nude mice and rats. Further studies are needed to elucidate the immunological response and function in hairless dogs.     

Effects of hormone treatment on chromosomal radiosensitivity of somatic and germ cells of Snell's dwarf mice

The X-ray induction of micronuclei and structural chromosomal aberrations was studied in bone-marrow cells of normal and dwarf (dw) mice in combination with thyroxine and/or prolactin treatment or otherwise. Hormone treatment clearly increased micronuclei induction but not chromosome breakage, suggesting that indirect effects were involved. Since no clear differences in the timing of the final stage of erythropoiesis could be found, it is likely that the indirect effects are mediated via the formation-differentiation kinetics of erythroblasts. The induction of reciprocal translocations by X-rays in stem cell spermatogonia of dwarf mice was lower than in normals and treatment with prolactin, growth hormone and/or thyroxin, did not influence the chromosomal radiosensitivity of spermatogonial stem cells.     

Effect of cyclosporine on the lymphoid organs of CBA mice]

The influence of cyclosporine which is an immunodepressant on morphology of the lymphoid organs was studied on CBA mice. The immunodepressant was administered intramuscularly in a single LD50 and in a dose of 7 mg/kg for the treatment course of 21 days. The examinations were performed in various periods within 28 days after discontinuation of the drug use. It was shown that cyclosporine induced cell depletion in the thymus cortical and medullar zones, inhibition of lymphocyte mitotic activity, alteration of the Hassall corpuscles and impairment of their formation. It also induced devastation of the thymus-dependent zones in the mesenteric lymph nodes and spleen. When cyclosporine was used in the course doses the morphological changes in all the lymphoid organs were more marked. The morphological changes were reversible.