Molecular weight of human alpha2-H-ferroglobulin subunits. Comparison with molecular weight of ferritin subunits]

alpha2 H globulin, a glycoferroprotein, was first demonstrated in the sera of patients with malignant diseases. This protein was isolated from cancerous human liver, and compared with ferritin, a ferroprotein showing some identical properties (presence of iron, high molecular weight, common antigenic determinants). However, physicochemical differences were observed between these two proteins. The study of protein dissociation was performed by polyacrylamide gel electrophoresis in sodium dodecyl sulfate after reduction by mercaptoethanol. A similar molecular weight of 19 000 is obtained for subunits of these two proteins. This value agrees well with the results obtained by other authors for ferritin.     

L'absorption du facteur «L.E.» par des noyaux cellulaires isolés

Summary The serum containing the L.E. factor loses its activity after having been put in contact with isolated cell nuclei. The electrophoretic examination shows a clear diminution of the gamma globulin and a slight diminution of the globulin alpha 2. That the factor responsible for the L.E. phenomenon can be absorbed by isolated cell nuclei is an argument in favor of the hypothesis that this factor is a substance having the character of an antinuclear anti-body, without one being able to exclude with certitude the possibility that this factor is an enzyme.     

The permeability of tumour vessels

Summary Experimental proof that tumour vessels are permeable to humoral agents but impermeable to cellular elements viz. leucocytes. The cause of this impermeability is believed to be the deposition of immunosuppressive alpha globulin on the walls of tumour vessels. This concept is of relevance in organ transplantation and cancer immunotherapy.     

Number of glucocorticoid receptors in lymphocytes and their sensitivity to hormone action

The study demonstrated a decreased level of glucocorticoid receptors (GR) in peripheral blood lymphocytes from hypercholesterolemic subjects, and an elevated level in patients with acute myocardial infarction. In the lymphocytes with a high GR number, dexamethasone inhibited [3H]-thymidine and [3H]-acetate incorporation into DNA and cholesterol, respectively, in the same manner as in the control cells. On the other hand, a decreased GR number resulted in a less efficient dexamethasone inhibition of the incorporation of labeled compounds. These data showed that the sensitivity of lymphocytes to glucocorticoids changed only with a decrease of GR level.     

Model of the interaction between trypsin and alpha 2-macroglobulin of porcine serum]

A comparative study of the dissociation into subunits of Porcine alpha2 M, either native or bound to trypsin (Tn), has been carried out in order to determine the modifications of the alpha2 M structure due to the formation of the Tn-alpha2 M complex. Analytical ultra-centrifugation at pH 3.5 shows that the dissociation is smaller when alpha 2 M is bound to trypsin. Electrophoresis in 4% polyacrylamide gels, in presence of 0.1% SDS, of alpha2 M and Tn-alpha2 M incubated in 1% SDS leads to the same conclusion; the enzyme must stabilize the quaternay structure of alpha2 M. In presence of SDS + beta-mercaptoethanol, only a molecular weight (M.W.) 200,000 band is revealed in electrophoresis pattern of native alpha2 M. In the case of reduced Tn-alpha2 M, some other bands of M.W. 100,000, 50,000, 30,000 appear. When trypsin is inactivated by TLCK 100,000 M.W. band is present, accompanied by the 200,000 M.W. band whose intensity is function of the alpha2 M concentration. The 100,000 M.W. band appears therefore characteristic of the formation of the complex which must imply a proteolytic cleavage in the middle of the 100,000 polypeptidic chain of alpha2 M. A model of the complex is proposed in which the enzyme forms a proteic bridge between the two halves of the alpha2 M molecule.     

Anomaly of the polypeptide and oligosaccharide chains of alpha-2-neuraminoglycoprotein in various types of hereditary angioneurotic edema

Using two-dimensional immuno-electrophoresis to study a morphological abnormality of the alpha 2-neuramino-glycoprotein (alpha 2-NGP) we have been able to observe allelic exclusion in patients afflicted by hereditary angioneurotic oedema [1]. With the aid of two-dimensional immuno-affino-electrophoresis, we have been able to show that in some cases, there exists a double abnormality of alpha 2-NGP associating a deficiency in post translating glycosylation with a loss of the inhibitory function of the C1 esterase.     

Effects of injury on the concentration of alpha1-macroglobulin and alpha2-macroglobulin in the plasmas of male and remale rats.

The effects of injury on the concentration of alpha1-macroglobulin and alpha2-macroglobulin in the plasmas of male and remale rats has been investigates. At 5 days after injury to the male rats the alpha1-macroglobulin concentration increased to 131% of its preinjury value. The alpha2-macroglobulin concentration increased more rapidly to a maximum of 86 times its initial value. In the female rats alpha2-macroglobulin increased only slightly and alpha1-macroglobulin not at all.     

Inhibition of DNA biosynthesis in human lymphocytes by alpha 1-antitrypsin]

Incorporation of tritiated thymidine into human lymphocytes from tonsils is markedly inhibited by purified alpha1-antitrypsin-preparations. This inhibitory effect is observed in lymphocytes stimulated by a mitogen factor (phytohemagglutinin) as in non stimulated lymphocytes.     

Antiproliferative effect of polyunsaturated fatty acids and interleukin-2 on normal and abnormal human lymphocytes

The polyunsaturated fatty acids (PUFAs), linoleic acid (LA), alpha linolenic acid (ALA), gamma linolenic acid (GLA), arachidonic acid (AA), docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), showed inhibition of growth of both normal and abnormal (Molt-4) human lymphocytes, and inhibition was concentration-dependent. Interestingly, the production of the lymphokine Interleukin-2 (IL-2) was elevated in Molt-4 cells, but it was reduced in the normal human lymphocytes. Addition of GLA or IL-2 or a combination of both showed enhancement of SO ₂ ^– and of lipid peroxidation levels, which were significantly higher in Molt-4 cells than in the normal lymphocytes. Reduction of protein concentration was also observed in both types of cells during this treatment. The data showed that the antiproliferative effects of GLA and IL-2 may partly be exerted through the elevated production of superoxide free radicals and peroxidatin products. This is a novel finding and therefore, further exploitation of combinations of PUFAs and IL-2 may be a possible way of combating cancer cell growth.     

Effect of a mitogenic concentration on membrane glycoconjugates of human lymphocytes

Periodate oxidation of human peripheral blood lymphocytes followed by reduction with 3H labelled sodium borohydride and acidic hydrolysis generates N-AN 7, glycerol and propane 1-2 diol. This indicates that sialyl, fucosyl and probably galactosyl residues are oxidized by periodate. Neuraminidase-treated lymphocytes exhibit decreased N-AN 7 levels, increased N-AN 8 levels and increased glycerol levels. Such results were neither found with mouse splenocytes nor with calf lymph node cells.     

Use of radioimmunoassay of "thyroxine binding globulin" to determine the concentration of free plasma thyroxine]

A relationship is proposed for calculating the concentration of free serum thyroxine using the measured values of thyroxine and thyroxine-binding globulin total concentrations. This calculation has been performed on a population of 335 patients. A good discrimination of the different thyroid diseases has been obtained.     

Hsp27 suppresses the formation of inclusion bodies induced by expression of R120G alpha B-crystallin,a cause of desmin-related myopathy

The R120G mutation in the small heat shock protein (sHSP) alpha B-crystallin has been identified in a family suffering from desmin-related myopathy. In this study, we characterized the features of transiently expressed R120G alpha B-crystallin in mammalian cells. In addition, we examined interactions of this mutant alpha B-crystallin with Hsp27, another representative sHSP. In HeLa cells, transiently expressed R120G alpha B-crystallin was mainly fractionated in the insoluble fraction, although wild-type alpha B-crystallin was predominantly found in the soluble fraction. In immunofluorescence studies, we found 15-25% of R120G alpha B-crystallin-expressing cells to contain multiple cytosolic inclusion bodies, in which Hsp27 was also localized. When R120G alpha B-crystallin and Hsp27 were transiently co-expressed in HeLa cells, the amount of R120G alpha B-crystallin in the soluble fraction was greater than with expression of R120G alpha B-crystallin alone. Moreover, co-expression resulted in reduced formation of inclusion bodies, suggesting that Hsp27 acts as a molecular chaperone for R120G alpha B-crystallin.     

An electrophoretic investigation of the binding of 3-14C coumarin to rat serum proteins.

The binding of coumarin to serum proteins of the rat has been demonstrated. Of the total bound coumarin (37% of injected dose), 36% was bound to slow and fast oc1 globulins, 11% to the post albumins, 10% to globulin and 9% to albumin.     

Apparition précoce d'une globuline anormale dans la rate du rat nourri au DAB

Summary An abnormal globulin has been detected in the spleen of Fisher inbred rats fed with a DAB containing basic diet. This abnormal globulin appears in the spleen on the sixth week after the initiation of the diet.

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Travail subventionné conjointement par le Ministère de la Santé de la Province de Québec et l'Institut du Cancer du Canada.     

Acid phosphatase activity of cytolytic T cells during cytolysis].

The localization of Golgi areas, particularly lysosomal bodies detected by their acid phosphatase activities, has been determined in the cytotoxic lymphocytes conjugated to their target cell. The study points out the preferential situation of these organelles close to the contact area between the two cells during the target cell lysis.     

Isoenzymes of creatine phosphokinase in white blood cells

Summary Creatine phosphokinase activity was found in human lymphocytes. Only MM type of the enzyme was detected in lymphocytes and polymorphonuclear leukocytes.Supported by U.S.P.H.S. MH 16 127. H.Y.M. is recipient of RCSA MH 47 808.     

The effect of cycloheximide on nuclear uH2A content

The effect of intraperitonal cycloheximide administration on acid-soluble rat liver chromatin proteins has been investigated by electrophoresis in acetic acid-urea polyacrylamide gels. A nonhistone protein, which migrates between oxidized histone H3 and histone H1 has been found to be increased in amount following cycloheximide treatment. This protein seems to be identical with semihistone protein H24 (uH2A). A possible relationship of uH2A to the inhibition of rRNA synthesis is discussed.     

Alpha 1-adrenergic stimulation of ketogenesis and fatty acid oxidation is associated with inhibition of lipogenesis in rat hepatocytes

The effect of norepinephrine on fatty acid synthesis (3H2O incorporation into fatty acids), on fatty acid oxidation to CO2 and on ketogenesis was studied in isolated hepatocytes of fed rats. After incubation with norepinephrine (50 microM), lipogenesis was lower (5.7 +/- 1.1 nmoles 3H2O incorporated into fatty acids/mg dry weight/30 min) than in controls (7.5 +/- 1.7; n = 6, p less than 0.02). In contrast, (1-14C) palmitate conversion into total ketone bodies was increased to 10.9 +/- 1.8 nmoles/mg/30 min with norepinephrine, vs 8.5 +/- 1.6 in controls (p less than 0.05), and more (1-14C) palmitate was converted to 14CO2 with norepinephrine than in controls (1.48 +/- 0.10 nmoles/mg/30 min vs 1.06 +/- 0.11, p less than 0.05). The inhibitory effect of norepinephrine on lipogenesis was abolished by addition of the alpha 1-receptor blocker prazosin, but not by alpha 2 or beta-blockers. The results demonstrate that the ketogenic effect of norepinephrine is coupled with an inhibitory effect on lipogenesis which may be explained by diminished activity of acetyl-CoA carboxylase, diminished formation of malonyl-CoA and decreased activity of carnitine palmitoyl transferase I.     

Stimulation of peripheral guinea pig blood lymphocytes by autologous epidermal cells]

Using a strictly autologous (and not syngeneic) mixed culture system in the guinea-pig, it was shown that Mitomycin C treated ear epidermal cells (E) were capable of stimulating peripheral blood lymphocytes (L) from the same animal. The proliferative response of the lymphocytes as measured by 3H thymidine incorporation, is optimal on the 5th day of culture, and when the ratio of the concentrations of the two cell populations (L : E) is 1 : 1. The autoreactivity of the lymphocytes varies with the animal.