Effect of splenin and splenic protein-free extracts on the adenosine deaminase activity in various organs of the rat

It has been shown that the adenosine deaminase activity of intact rats increases in such lymphoid organs as the thymus and spleen under the influence of splenic protein-free extracts dissolved in the ratio of 1:100. The enzyme activity in testes does not change but its decrease (by 26.2%) is observed in the adrenal glands under the influence of the splenic protein-free extract. An analogous effect is revealed in splenin and its fractions. The splenic protein-free extract increases (by 83%) the enzyme activity in the thymus of splenectomized rats as compared to intact animals but does not change it in a homogenate of testes.     

The effect of thymus extracts on phosphorus compounds in muscle and serum, and on serum calcium

1. Thymectomy in young rabbits decreased the ATP content and increased the inorganic phosphate content of skeletal muscle. The serum calcium content was decreased, whereas the inorganic phosphate content was increased. 2. The administration of a lipid fraction (TL) or protein fractions (CIF and TP) of thymus extracts to thymectomized rabbits in short-term experiments increased the ATP content of muscle and decreased the inorganic phosphate contents of muscle and serum. Serum calcium content was increased. 3. The action of the thymus extract TP was specific only on the phosphate compounds, since the increase in serum calcium concentration was also caused by the control extract from muscle. The action of the extract TL is not specific, being paralleled by the action of a control extract from muscle.     

In vitro allogeneic response of human lymphocytes dependent upon dialyzable plasma components and a thymic hormone, THF.

The in vitro response to allogeneic stimulation of human lymphocytes obtained from umbilical cord blood and from adult peripheral blood is dependent upon the presence of dialyzable plasma components. We observed here a reduced allogeneic response of human lymphocytes in the presence of a dialyzed human plasma as compared to their reactivity in the presence of whole human plasma. This impaired mixed lymphocyte culture response was restored by the addition of thymus humoral factor (THF), a calf thymus extract. It is suggested that dialysis depletes the plasma of its natural thymic hormone(s) content, this being replaced by the addition of THF. Restoration of the in vitro allogeneic response of human lymphocytes by THF was shown to be specific, since such effect was not observed when calf spleen extract or bovine serum albumin were tested.     

An age-dependent thymic secretion modulates testicular function

The acetone extract obtained from the thymuses of 14-day-old rats contains a factor that interacts with hCG in the adult testis cells and inhibits testosterone production. Experiments were designed to investigate the possible secretion of this factor. The media from the incubation of thymuses from 14-day-old rats were processed by molecular sieve chromatography and the fractions assayed using a bioassay with testicular cells in vitro. A fraction of approx. 30 kDa was found to inhibit the hCG-stimulated production of testosterone. In addition, the influence of age on the release of the active fraction was investigated. The inhibitory effect of this thymus product was greatest in the neonatal period (1-14 days) and declined thereafter towards the onset of puberty. The age-related decline of the inhibitory activity correlated with relative thymus weight and also with the amount of protein released to the incubation media. Thymic fraction activity is, however, present in the adult gland. These results suggest that the thymus secretes active agents that are able to modulate the response of testicular cells to hCG and that their release seems to be age-related.     

Study of the thymus as a source of humoral factors stimulating antibody formation]

A fraction stimulating antibody formation in neonatal animals was obtained in separation of the calf thymus extract (1A) prepared by the method of Goldstein et al. on a column with Sephadex G-25 (fine). Testing of the activity of analogous fractions of the extracts of calf tonsils, spleen, lymph nodes and the liver led to a supposition that the thymus was the only source of specific humoral factor stimulating antibody formation, which could accumulate in the peripheral lymphoid formations. Low activity of tonsillar extracts failed to confirm the hypothesis on the role played by the tonsils as the central immunity organ similar to the bursa Fabricii.     

Selective effect of fractions of a yeast extract (PCO) on normal and malignant cells

The selective action of two fractions of PCO (a yeast extract) on normal and malignant cells was demonstrated. In vivo, the mitotic activity of malignant cells was inhibited by the methanol-insoluble fraction of PCO, whereas the methanol-soluble fraction caused no inhibition. The in vitro studies, however, showed inhibition of mitoses with both fractions. The malignant cells employed in vitro and in vivo were the Krebs-2 and Ehrlich carcinomas. The nonneoplastic cells tested in vitro were established cultures of epithelial-like cells from murine bone marrow and thymus, and corneal epithelium and peripheral blood in vivo.     

A thymus factor influences the in vitro testosterone secretion of Leydig cells in the rat

Thymus extracts obtained from 15-day-old rats were fractionated through molecular sieve chromatography, and the fractions assayed in vitro by changes produced in the testosterone secretion of Leydig cells obtained from adult rat testes. Fractions corresponding to 27-28000 mol wt of the thymus extract diminish the testosterone secretion of Leydig cells stimulated with hCG. No changes in the basal testosterone secretion were produced by the presence of the thymus fractions. The inhibitory effect is dose related and persists during 180 min of incubation. Fractions of the same mol wt obtained from liver, heart and spleen do not modify the testosterone secretion of Leydig cells. The inhibitory activity of the thymus factor disappears after heat or trypsin treatment. Further fractioning in preparative flat bed electrofocusing makes manifest that the inhibitory activity is focused at pH 4.7. The data demonstrate the existence in rat thymus of a factor, probably of protein nature, which modifies the in vitro hCG response of a testis cell suspension.     

Role of L-alanine in the response of human lymphocytes to PHA and Con A

The response of umbilical cord blood lymphocytes (UCBL) to PHA and Con A is strongly dependent upon the presence of dialyzable plasma components. The impaired response of human cells in the presence of dialyzed human plasma was restored by calf thymus extract. In the present experiments we have further purified calf thymus extract by means of paper electrophoresis and chromatography on thin-layer cellulose plates. We reached the conclusion that the active material in this model is a single amino acid, alanine. When the different isomeric forms of alanine were tested, we found that L-alanine is the only biologically active material. In addition, we have observed here that the allogeneic response of UCBL is also dependent upon the presence of dialyzable plasma components. This impaired allogeneic response of UCBL in the presence of DHP was restored by addition of L-alanine. The present findings suggest that, under in vitro conditions, for human cells to respond to mitogenic or allogeneic stimulation L-alanine is essential.     

Some requirements for the response of separated T-cell sub-populations to the mitogens phytohaemagglutinin and concanavalin A.

The proliferative response of various separated populations of mouse spleen and thymus lymphocytes to the mitogen phytohaemagglutinin (PHA) was not a direct function of the level of responsive T cells, but was governed by other regulatory effects. These included a stimulation by adherent macrophages, an inhibition by a separate population of adherent cells and an adherent cell independent restriction of proliferation at high cell concentration. In contrast, the proliferative response to Concanavalin A (Con A) was more closely related to the level of responsive T cells. All density and electrophoretically isolated sub-sets of splenic T cells appeared capable of a proliferative response to PHA and Con A, although under some conditions the PHA responsiveness of certain fractions was suppressed. In the thymus, the minor low theta sub-population appeared capable of response to both mitogens, and accounted for all the activity of the unfractioned thymus cells. No response to either mitogen could be obtained from the major, high theta thymocyte population.     

Studies on the regulation of lymphocyte production in the murine thymus and some effects of a crude thymus extract.

Cell proliferation in the murine thymus was studied in vivo under normal conditions and from 0 to 24 hr after a single injection of a water-soluble extract from mouse thymus, mouse spleen, and mouse skin. The thymus extract reduced during the first 24 hr the mitiotic activity 40%; the spleen extract had a weaker inhibitory effect. The skin extract had no such effect. The thymus extract and spleen extract inhibited the flux of cells into the S phase 0-8 hr after the injection of the extract. Initial labelling index was also reduced in this period. Eight hours after injection of the thymus or spleen extracts the inhibited cells initiated DNA synthesis. The rate of progression of blast cells through the cell cycle was normal 24 hr after the injection of the extracts. It was deduced from the analysis that the thymus extract inhibits processes triggering G0/G1 cells into DNA synthesis, the inhibition of G2 efflux being of minor importance. Finally a model for the regulation of proliferating thymic blast cells and the emigration of small lymphocytes from the thymus is proposed.     

Histones of the fungi, Endomyces magnusii and Neurospora crassa]

Histones of Endomyces magnusii and Neurospora crassa were found to consist of four main fractions similar to calf thymus histones in their electrophoretic mobilities, molecular sizes and chromatographic behaviour on Akrilex P-60. Two of them are homologous to the most conservative histones H3 and H4. Other two fractions correspond to the histones H2A and H2B; however, they have some pecularities. A fraction of N. crassa histones corresponding to the H2B was isolated in a homogeneous state by means of gel filtration. It appeared to be very similar to calf thymus histone H2B in its amino acid composition.     

A thymic factor increasing the blood sugar level.

The thymus extract prepared by using isotonic NaC1 solution causes hyperglycaemy and the thymectomy, too, produces the same effect. Consequently, the active substance of the thymus is produced elsewhere in the organism and being stored within the thymus, gets into the extract by homogenizing its cells. Both the thymectomy and the thymic factor increase the effect of alloxan and this sensitizing effect can be prevented by pretreatment with prednisolone.     

A dihydroxy-gamma-lactone as an oviposition stimulant for the swallowtail butterfly, Papilio bianor, from the rutaceous plant, Orixa japonica

The oviposition response of the Rutaceae-feeding swallowtail butterfly, Papilio bianor, was induced by a methanolic extract from leaves of its major host, Orixa japonica. Several components were responsible for this oviposition response. One of the stimulants was isolated and identified as (-)-2-C-methyl-D-erythrono-1,4-lactone. The compound was inactive alone, but elicited oviposition behavior when mixed with other fractions.     

STUDIES ON THE REGULATION OF LYMPHOCYTE PRODUCTION IN THE MURINE THYMUS AND SOME EFFECTS OF A CRUDE THYMUS EXTRACT

Cell proliferation in the murine thymus was studied in vivo under normal conditions and from 0 to 24 hr after a single injection of a water-soluble extract from mouse thymus, mouse spleen, and mouse skin. The thymus extract reduced during the first 24 hr the mitotic activity 40%; the spleen extract had a weaker inhibitory effect. The skin extract had no such effect. The thymus extract and spleen extract inhibited the flux of cells into the S phase 0–8 hr after the injection of the extract. Initial labelling index was also reduced in this period. Eight hours after injection of the thymus or spleen extracts the inhibited cells initiated DNA synthesis. The rate of progression of blast cells through the cell cycle was normal 24 hr after the injection of the extracts. It was deduced from the analysis that the thymus extract inhibits processes triggering Go/Gi cells into DNA synthesis, the inhibition of G₂ efflux being of minor importance. Finally a model for the regulation of proliferating thymic blast cells and the emigration of small lymphocytes from the thymus is proposed.     

Antibacterial and antifungal activities of andrachne cordifolia muell

The crude methanolic extract of Andrachne cordifolia Muell. (Euphorbiaceae) and its various fractions in different solvent systems (chloroform, ethyl acetate and n-butanol) were screened for antibacterial and antifungal activities. Crude extract and subsequent fractions demonstrated moderate to excellent antibacterial activities against the tested pathogens. Highest antibacterial activity was displayed by both chloroform and ethyl acetate fractions (100%) followed by the crude extract (68%) against Salmonella typhi. Similarly, crude extract and its subsequent fractions showed mild to excellent activities in antifungal bioassay with maximum (76%) antifungal activity against Microsporum canis by the chloroform fraction followed by the crude extract (65%).     

Calf thymus composition: a comparison of differential centrifugation and chemical fractionation procedures

The extraction behavior of thymus and the composition of fractions prepared from this organ has been studied. Sequential extraction methods using 0.15 M NaCl followed by water gave information with respect to the weight fraction of cytoplasmic and nuclear constituents. Lipide, nucleic acid, and electrophoretic analysis of the extracts provided additional information. A less complex electrophoretic pattern was obtained from subsequent extracts in the sequence. Sucrose and saline dispersates obtained from tissue fragmented with either the Potter-Elvehjem homogenizer or in a Waring blendor were fractionated, using standard differential sedimentation methods. The fractions obtained by means of four different dispersion procedures were compared in terms of yield, chemical analysis, and electrophoretic composition. The quantity of material in thymus having the sedimentation characteristics of liver mitochondrial and microsomal fractions was remarkably small. Both the suspension medium employed and the method used to bring about a disruption of the cells in the tissue affected the yield of "particulate" material. The components present in the later extracts in the sequence, E(4) to E(7), in the case of sequential extraction study resembled with respect to chemical composition and electrophoretic characteristics, the microsome fraction prepared by differential sedimentation methods. About 76 per cent of the PNA in the tissue appeared to be in the cytoplasm. The remaining 24 per cent PNA was found in the nucleus and accounted for 1.7 per cent of nucleus on a dry weight basis. From 75 to 88 per cent of cytoplasmic PNA was extracted from the tissue and 76 to 94 per cent of the PNA in the extract was found in the final supernatant solutions, depending upon the dispersion methods and suspension medium used in the extraction procedure. The composition of the final supernatant fractions using differential sedimentation methods were comparable in terms of electrophoretic properties, protein concentration, nucleic acid content, and fractionation behavior to saline extracts E(1) to E(3), of thymus used in earlier studies.     

Enzyme inhibition activities of Teucrium royleanum

The crude methanolic extract and chloroform, ethyl acetate and n-butanol fractions of Teucrium royleanum were examined as inhibitors of actylcholinesterase, butyrylcholinesterase, lipoxygenase and urease. A significant enzyme inhibition activity (52-83%) was shown by the crude methanolic extract and its fractions against acetylcholinesterase, while low to outstanding enzyme inhibitory activity was shown (19-93%) against butyrylcholinesterase. The crude methanolic extract and its various fractions demonstrated low activity against lipoxygenase and inactive against urease.     

Migration of putative progenitor T cells in response to thymus-derived chemotactic factors

Progenitor T cells reach the thymus through the circulation from hematopoietic organs and then migrate toward the site of differentiation in the thymus. The mechanism that regulates such intrathymic migration is not well understood. In order to clarify this mechanism, in vitro chemotactic activity for murine thymocytes was assayed in the extracts and culture supernatants of thymic tissue elements. A potent thymocyte chemotactic activity was found in the extract and culture supernatant from Ig-, Ia- thymic stromal cells. Peanut agglutinin-positive (PNA+1), Thy 1+, TL-, Lyt 1+2-, L3T4- thymocytes, Ig-, Thy 1- bone marrow cells, and mononuclear cells of spleen and peripheral blood, but neither B cells nor lymph node cells, were chemotactically attracted by the factor(s). The chemotactic activity was found in none of the following materials tested: the extract and culture supernatant of thymocytes, culture supernatant of lymph node stromal cells, normal mouse serum, and zymosan-activated serum. The chemotactic activity was found in three molecular fractions by gel chromatography. The activity in all three fractions was destroyed by trypsin digestion or by heating at 56 degrees C for 30 min. These results suggest that Ig-, Ia- thymic stromal cells but not thymocytes secrete a chemotactic factor(s) for progenitor T cells with three molecular species. The factor is considered to play an important role in the migration of intrathymic progenitor T cells into the site of differentiation.     

木豆叶醇提物对皮质酮诱导的PC12细胞损伤的保护作用

建立皮质酮诱导的PC12细胞损伤模型并观察木豆叶醇提物及不同组分对皮质酮损伤PC12细胞的保护作用.以100μ mol/L的皮质酮诱导PC12细胞损伤;损伤后的PC12细胞与木豆叶醇提物及不同组分孵育24h,通过形态学观察、MTT检测、LDH测定,研究各组分对皮质酮损伤PC12细胞的保护作用.结果表明,PC12细胞与皮质酮孵育48 h后细胞存活率明显降低,而LDH水平显著升高.而加入木豆叶醇提物及各组分时上述效果明显减轻,且存在明显的剂量依赖关系.从以上结果可知,木豆叶醇提物及不同组分对皮质酮损伤的PC12细胞均有保护作用,且醇提物的效果最好.