Soluble suppressor activity of concanavalin A-activated spleen cells on B-lymphocyte colony formation in vitro.

Supernates from concanavalin A (Con A)-activated mouse spleen cell cultures suppress the formation of B-lymphocyte colonies (BLC) in soft agar culture by 30 to 95%. Con A-induced BLC suppressive culture supernates can be heated at 80 °C for 1 hr without losing activity. The BLC suppressive activity is eliminated totally by trypsin treatment and partly by treatment with β-galactosidase. Activity is unaffected by treatment with DNAse, RNAse, and α-glucosidase. By ultrafiltration the BLC suppressive factor(s) was shown to have a molecular weight greater than 300,000. These data suggest that BLC suppression is mediated by a protein-carbohydrate complex. BLC suppression was obtained when normal spleen cells were preincubated in Con A-activated supernates for only 1 hr at 37 °C. BLC suppressor activity was absent in the supernatant fluid of Con A exposed anti-θ-treated spleen cells, nonadherent spleen cells, extensively washed spleen cells, and spleen cells from nude (athymic) mice suggesting that cells responsible for Con A-induced BLC suppression are adherent, fragile cells of the T lineage. Con A-activated spleen cell supernates do not suppress colony formation in soft agar by normal mouse granulocyte-macrophage precursors, by plasmacytoma cells, T-lymphoma cells, or by carcinoma cells. However, colony formation by Abelson's murine leukemia virus transformed B-lymphoma cells was suppressed by 95% suggesting a relationship between this immature B-lymphoma line and B-lymphocyte colony-forming cells. Con A-activated spleen cell supernates do not suppress lymphocyte activation in liquid culture by phytohemagglutinin, Con A, or lipopolysaccharide. Heat-treated supernates—which inhibited BLC development by 90–95%—did not suppress the plaque formation by spleen cells immunized in vivo or in vitro by sheep red blood cells.     

Systematic studies of Pinus balfouriana based on volatile terpenoids from wood and needles and on seed morphology

Essential oil from wood and from needles of Pinus balfouriana, growing in six geographically well-separated locations in California, was analysed by GLC. Several monoterpenoid components, in particular -pinene from needles, were found to be usable for distinguishing between trees from the northern and southern parts of the geographic range. Similarity coefficients were calculated and dendrograms constructed. These demonstrated the distinct separation of the northern from the southern populations, and thus substantiated the proposal by Mastrogiuseppe to regard the southern populations as a subspecies. While the northern populations exhibited a tendency to produce larger seeds with longer wings, the difference was of only moderate diagnostic value.     

Evaluation of three E-rosette assays in melanoma patients

Summary The percentage of E-rosette-forming cells (E-RFC) was determined repeatedly in the peripheral blood of 43 patients with malignant melanoma. Three methods of E-rosette assaying were used: total E-rosette test, active E-rosette test, and 29° C E-rosette assay.Depressed E-RFC values were found in fewer assays than normal values. The mean values of E-RFC and the proportion of depressed E-RFC in patients in stage I did not differ from the values in healthy control persons whatever method of assay was used.The frequency of depressed E-RFC values was higher in advanced stages. Significant differences were demonstrated between stage I and stages II and III combined in the values for total and for active E-rosettes (P<0.01).The active E-rosette test and the 29° C E-rosette assay gave no more positive results (i.e., depressed E-RFC values) than the total E-rosette test in melanoma patients.     

The increase in activity of acid hydrolases in muscles of rats after subcutaneous administration of dimethyl-para-phenylene diamine. A combined histochemical and biochemical investigation

Summary The increase in activity of acid hydrolases in skeletal muscles of rats after subcutaneous administration of dimethyl-para-phenylene diamine (DPPD) was studied with a combined histochemical and biochemical investigation. In part I the histochemical findings were presented. In this communication the biochemical findings are reported and compared with the histochemical findings.In homogenates of m. biceps femoris, m. gastrocnemius and m. rectus femoris of DPPD-treated rats, the activity of the lysosomal acid hydrolases, cathepsin D, acid maltase, acid phosphatase, and -glucuronidase was increased. This increase in activity was maximal after 7 to 9 days of DPPD treatment and ran parallel to the severity of the pathological changes. Statistical calculations clearly reveal that the increased activity of one acid hydrolase was significantly paralleled by an increased activity of a second acid hydrolase. Moreover these calculations reveal that the biochemical activity findings correlated with the histochemical activity findings. However it was remarkable that in the histochemical study, the estimated increase in acid phosphatase activity was much more than the increase in acid phosphatase activity found biochemically, whilst on the other hand the histochemically estimated increase in -glucuronidase activity corresponded with the biochemical observations. The results of gel filtration techniques have shown that this discrepancy of acid phosphatase activity was caused by different substrate specificity of the different isoenzymes of acid phosphatase and that as a result of the DPPD treatment the isoenzyme pattern had been altered. The elution patterns showed three distinct isoenzymes of acid phosphatase of normal and of DPPD treated rats. These isoenzymes, termed I, II and III, have molecular weights of: 200,000 or more, 83,500–104,500 and 14,500–18,100. Isoenzymes I and II split the substrates 4-methylumbelliferyl phosphate and naphthol AS-BI phosphate and the activity is strongly increased in the muscles of the DPPD treated rats. Isoenzyme III does not split naphthol AS-BI phosphate and the activity is not increased in the muscles of the DPPD treated rats. Considering the fact that it has been shown that the activity of isoenzyme III is high compared with that of the isoenzymes I and II, it is important to realise that by using naphthol AS-BI phosphate not all acid phosphatase can be demonstrated in sections of skeletal muscle.This study was partly supported by a grant from the Prinses Beatrix Fonds, 's Gravenhage, The Netherlands, and was mainly extracted from the Ph. D. thesis of D.E. Israël (1977).     

H-2 antigens,on mast cell membrane,as target antigens for anaphylactic degranulation

When single mast cells were isolated by micromanipulation, specific H-2 antigen-bearing mast cells were degranulated upon incubation with alloimmune sera (DAAD). When specific alloantigens were presented by lymphoid cells only, no degranulation occurred. Only antigen-bearing mast cells were degranulated, irrespectively of the presence of antigen-bearing lymphoid cells. Therefore, in DAAD, anaphylactic alloantibodies can and must recognize specific H-2 antigens on the mast cell membrane and simultaneously deliver the degranulation signal, through an Fc-Fc receptor interaction on the surface of the same mast cell.     

Adjacent repeating units of xenopus laevis 5S DNA can be heterogeneous in length

The distribution of length heterogeneity in adjacent repeating units of X. laevis 5S DNA has been examined by “cloning” 5S DNA in bacteria. Fragments of 5S DNA produced by partial digestion with Hind III and containing 1, 4, and 5 repeating units have been inserted at the single Hind III site of the tetracycline-resistance plasmid, pSC101, and the hybrid plasmids cloned in E. coli. Adjacent 5S DNA repeats in the cloned multi-repeat fragments can differ in length. This finding rules out some mechanisms which have been proposed to account for the parallel evolution of tandem repeated DNAs. The results are consistent with an unequal crossing-over mechanism and place some constraints on the molecular processes in this recombinatory event.     

Permeability of sarcoplasmic reticulum membrane. The effect of changed ionic environments on Ca2+ release

Summary Permeability properties and the effects of a changed membrane potential on Ca²⁺ release of sarcoplasmic reticulum vesicles of rabbit skeletal muscle were investigated by Millipore filtration. The relative permeability of sarcoplasmic reticulum to solutes determined under conditions of isotope exchange at equilibrium and/or under conditions of net flow of solute and water into the vesicles was as follows: sucrose, Ca²⁺, Mn²⁺–, choline⁺, Tris⁺–+, Na⁺, Li⁺, Cl^–. Transient membrane potentials were induced by rapidly changing the ionic environment of the vesicles. Knowledge of the relative permeation rates of the above ions allowed prediction of the direction and extent of membrane polarization. Osmotic effects in the polarization measurements due to the rapid influx of solute and water into the vesicles were minimized by using media containing a fast (K⁺ or Cl^–) and a relatively slow (gluconate^– or choline⁺) penetrating ion.⁴⁵Ca²⁺ efflux from vesicles derived from different parts of the sarcoplasmic reticulum structure was not appreciably changed when vesicles were made more positive inside (choline chloride potassium gluconate) or more negative inside (potassium gluconate choline chloride). These studies suggest that part or all of the ion-induced changes in sarcoplasmic reticulum membrane permeability, previously interpreted to indicate depolarization-induced Ca²⁺ release, may be due to osmotic effects.     

The pineal gland of the mole-rat (Spalax ehrenbergi,Nehring)

Summary A comparative investigation of the distribution of monoaminergic neurons in non-malacostracan crustaceans was performed with the histochemical fluorescence method of Falck-Hillarp.Two fluorophores were found: the more widespread of the two emits a green fluorescence; and the more sparsely distributed emits a yellow to brown-yellow fluorescence.Specific green fluorescent areas were shown to exist in the protocerebrum. The central body and the optic ganglia of the compound eye (where present) are always fluorescent. Moreover, the centre of the nauplius eye may have a green fluorophore, as in ostracods, and a neuropile area, here called the frontal area. These neuropile centres are known from ordinary histological studies of the nervous system. In addition, there are specific monoaminergic centres, such as the so-called dorsal area of phyllopods and anostracans as well as the copepod specific areas. Specific monoaminergic areas appear in the deutocerebrum and the suboesophageal ganglion where they are particularly well developed.Presumed sensory neurons in the cavity receptor organ of Artemia salina are shown to be monoaminergic. Monoaminergic sensory neurons have not been described previously in Arthropods.Presumed motor innervation of hind-gut and trunk muscles is also found, and it is concluded that in crustaceans neurons of every type (sensory, internuncial, motor) may be monoaminergic.We have enjoyed unrestricted laboratory facilities at the Department of Histology, Faculty of Medicine, and with great pleasure express our sincere thanks to Prof. Bengt Falck. — Grants from the Swedish Natural Science Research Council (2760-007), the Swedish Medical Research Council (04X-712), the Royal Swedish Academy of Science (Hierta-Retzius), the Royal Physiographic Society of Lund, and the University of Lund supported the work.     

Conduite antisociale et longueur du chromosome Y

Summary A new case of free trisomy for the short arm of No. 9 chromosome identified by Giemsa staining and Giemsa-11 technique is reported.