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Effect of inhibition of glucose and fat metabolism on galanin-R1 receptor mRNA levels in the rat hypothalamic paraventricular and supraoptic nuclei.

Using in situ hybridization histochemistry we have studied the effect of glucose and fat deprivation on galanin-R1 receptor (GAL-R1-R) mRNA levels in the rat paraventricular (PVN) and supraoptic (SON) nuclei after single and repeated i.p. administration of a glucose antimetabolite 2-deoxy-D-glucose (DG), as well as of a fatty acid antimetabolite, sodium mercaptoacetate (MA), treatments known to increase food intake. Both DG and MA injections caused an increase in levels of GAL-R1 mRNA transcripts in the PVN and SON. These results indicate that glucose and fat deprivation increase the sensitivity of PVN and SON neurons to galanin, and that regulation of receptor levels may be an important mechanism in galaninergic signalling.

Animals↗

Monocytic differentiation of HL-60 promyelocytic leukemia cells correlates with the induction of Bcl-xL.

Treatment of human promyelocytic leukemia HL-60 cells with phorbol esters ultimately induces the differentiation of these cells along the monocyte/macrophage lineage, whereas treatment with retinoic acid or DMSO induces granulocytic/neutrophillic differentiation. In this study, we demonstrate the disparate fates of HL-60 cells treated with the phorbol ester 12,13-phorbol dibutyric acid (PDBu) or DMSO. After DMSO treatment, HL-60 cells eventually died via apoptosis, whereas the viability of PDBu-treated cells was not affected during the same interval. The levels of the apoptosis effector proteins Bak and Bad were enhanced, whereas there was a slight down-regulation of the apoptosis suppressor protein Bcl-2 after treatment of the cells with PDBu and DMSO. Treatment with DMSO resulted in the elevation of the apoptosis effector Bax, whereas treatment with PDBu did not significantly alter the levels of this protein. However, treatment of HL-60 cells with PDBu induced the rapid expression of the apoptosis suppressor protein Bcl-xL, whereas the expression of this protein remained unaltered in DMSO-treated cells. The generality of this finding was confirmed by the induction of Bcl-xL in human myeloid U-937 cells, human peripheral blood monocytes exposed to phorbol ester, and mouse thioglycollate-activated and resident peritoneal macrophages. PDBu-treated HL-60 cells remained viable for 7 days and thereafter began to die via apoptosis, with a concomitant down-regulation of Bcl-xL. In conclusion, we propose that Bcl-xL expression is associated with differentiation and survival of hematopoietic cells along the monocyte/macrophage lineage.

Apoptosis↗

[Inhibitory effects of esculentoside A on mouse macrophages and antibody production].

Esculentoside A (EsA) is a kind of saponin isolated from Phytolacca esculenta Van Houtte. It was shown to significantly inhibit phagocytic activity, intracellular and extracellular production of interleukin-1 by thioglycollate primed murine peritoneal macrophages in vitro at the concentration 0.01-1.0 mumol.L-1. In vivo experiments showed that EsA 2.5-5 mg.kg-1 markedly decreased serum hemolysin concentration in sensitized mice challenged with sheep red blood cells. Inhibition of antibody production by B lymphocytes, phagocytosis and the production of inflammatory mediators by macrophages may partially explain the wide and strong anti-inflammatory effect of EsA.

Animals↗

The colony-stimulating factors induce expression of insulin-like growth factor-I messenger ribonucleic acid during hematopoiesis.

Murine bone marrow cells cultured in the presence of colony-stimulating factor-1 (CSF-1) showed coordinate induction of insulin-like growth factor-I (IGF-I) messenger RNA (mRNA) during the differentiation process, and these transcripts increased approximately 50- to 75-fold over the virtually negligible levels measured in freshly isolated bone marrow. In contrast, transcripts for the IGF-I receptor were evident in freshly isolated rat bone marrow cells and showed a 50% down-regulation during differentiation. Addition of a variety of single lineage and multilineage CSFs, including CSF-1, interleukin-3, granulocyte-macrophage-CSF, and granulocyte-CSF to mouse bone marrow cultures revealed that induction of IGF-I mRNA is a universal feature of differentiation with these CSFs, although IGF-I transcripts are at least 10- to 20-fold higher in CSF-1- and interleukin-3-differentiated lineages than in other cultures. The IGF-I induced by CSF-1 was biologically active because a natural ligand of IGF-I, IGF-binding protein-3, caused significant down-regulation of cellular proliferation, and this could be reversed by the addition of exogenous IGF-I. In addition, whereas IGF-I mRNA could be detected in resident peritoneal macrophages, these transcripts were increased 6-fold after a local injection of thioglycollate, a stimulus that induces macrophage proliferation and differentiation in vivo. These results show that CSFs induce expression of the growth factor IGF-I during differentiation of hematopoietic cells into multiple myeloid lineages and that this endogenously produced IGF-I is also a growth factor for hematopoietic cells. The induction of IGF-I mRNA during hematopoiesis should provide a new approach to understanding the expression of this gene during development and differentiation.

Animals↗

Synthesis and applications of chitosan mercaptanes as heavy metal retention agent.

Chitosan, poly-beta(1-->4)-2 amino-2-deoxy-D-Glucopyranose is a biopolymer obtained by extensive deacetylation of chitin [poly-beta(1-->4)-2-acetamide-2-deoxy-D-Glucopyranose], main constituent of crustacean shells. The present study was carried out using crab shells from nylon shrimps (Heterocarpus reedi). Despite the abundance of raw material in our environment, little work has been published in this field using derivatives. The main goal of this work is to develop a good method to prepare chitosan mercaptanes derivatives using mercaptoacetic acid and 1-chloro-2,3-epoxy propane propionic acid. The evaluation of the retention capacities using several concentrations of copper and mercury solutions with concentrations ranging from 10 to 104 ppm at pH 2.5 and 4.5 are tested. A comparison of the absorption isotherms with Langmuir isotherms is also reported. Full characterization of the derivatives was carried out using FTIR, elemental analysis and TGA. The morphology of chitosan and derivatives is compared before and after treating polymers with mercury and copper ions.

Adsorption↗

Thiazolidin-4-one formation. Mechanistic and synthetic aspects of the reaction of imines and mercaptoacetic acid under microwave and conventional heating.

Microwave irradiation of a mixture of benzylidene-anilines and mercaptoacetic acid in benzene gives 1,3-thiazolidin-4-ones in very high yield (65-90%), whereas the same reaction performed through using the conventional method, at reflux temperature, requires a much longer time and gives a much lower yield (25-69%). This difference seems to be due to some intermediates and by-products formed during the conventional reaction. On the basis of 1H NMR studies, two different mechanisms, acting in benzene and in DMF, respectively, have been hypothesized for the thiazolidin-4-one system formation.

Hot Temperature↗

Mitogenic and polyclonal B cell activation activities of synthetic lipid A analogues.

The activation of murine B cells and macrophages by synthetic lipid A analogues, solubilized with triethylamine and complexed with bovine serum albumin, were investigated in vitro. The analogues used are nonphosphorylated, C-1 or C-4' monophosphorylated and C-1,4' diphosphorylated derivatives of beta-1,6-linked D-glucosamine disaccharide possessing both ester- and amide-bound fatty acid substituents. They were divided into 4 groups, A, B, C and D in terms of the fatty acid substitution. Ester- and amine-bound fatty acids of the analogues are both tetradecanoic acids (C14) in group A, C14 and (R)-3-hydroxytetradecanoic acids (C14-OH) in group B, both C14-OH in group C and C14-OH and (R)-3-tetradecanoyloxytetradecanoic acids in group D. Mitogenic activity was exhibited in spleen cells from C3H/HeN mice by the C-1 monophosphorylated analogues in groups A and B, and by the C-4' monophosphorylated analogues in groups B, C and D, but not in cells from C3H/HeJ mice. Nonphosphorylated analogues in groups A, B and C, and C-4' monophosphorylated analogue in group A showed negative mitogenic activity. Only the nonphosphorylated analogue in group D exhibited mitogenic activity in spleen cells from C3H/HeJ mice as well as those from C3H/HeN mice. None of the other analogues exhibited the activity in C3H/HeJ spleen cells. Polyclonal B cell activation activity was exhibited by the C-1 monophosphorylated analogues in groups A and B, and by the C-4' monophosphorylated analogues in groups C and D. Nonphosphorylated analogues in all groups and C-4' monophosphorylated analogues in groups A and B showed negative PBA activity. None of the analogues tested could induce any cytostatic macrophages from thioglycollate-elicited peritoneal macrophages.

Animals↗

Use of a novel method to characterize the response of spores of non-proteolytic Clostridium botulinum types B, E and F to a wide range of germinants and conditions.

AIMS: Limited information is available on the germination triggers for spores of non-proteolytic Clostridium botulinum. An automated system was used to study the effect of a large number of potential germinants, of temperature and pH, and aerobic and anaerobic conditions, on germination of spores of non-proteolytic Cl. botulinum types B, E and F. METHODS AND RESULTS: A Bioscreen analyser was used to measure germination by decrease in optical density. Results were confirmed by phase-contrast light microscopy. Spores of strains producing type B, E and F toxin gave similar results. Optimum germination occurred in L-alanine/L-lactate, L-cysteine/L-lactate and L-serine/L-lactate (50 mmol l(-1) of each). A further 12 combinations of factors induced germination. Sodium bicarbonate, sodium thioglycollate and heat shock each enhanced germination, but were not essential. Germination was similar in aerobic and anaerobic conditions. The optimum pH range was 5.5-8.0, germination occurred at 1-40 degrees C, but not at 50 degrees C, and was optimal at 20-25 degrees C. CONCLUSIONS: The automated system enabled a systematic study of germination requirements, and provided an insight into germination in spores of non-proteolytic Cl. botulinum. SIGNIFICANCE AND IMPACT OF THE STUDY: The results extend understanding of germination of non-proteolytic Cl. botulinum spores, and provide a basis for improving detection of viable spores.

Aerobiosis↗

Interaction of Chlamydia psittaci with mouse peritoneal macrophages.

L-cell-grown Chlamydia psittaci elementary bodies (EB) were rapidly phagocytized by mouse peritoneal macrophages in vitro. However, the intracellular fate of chlamydiae in macrophages appeared to be dependent on the multiplicity of infection (MOI), i.e., the EB-to-macrophage ratio, and the treatment of the EB. At an MOI of 1:1 or less, survival is maximal, and growth and multiplication of live, untreated chlamydiae did occur. In contrast, at a high MOI (100:1), survival of chlamydiae is reduced, as confirmed by release of 3H-labeled nucleic acid into the supernatant. At the high MOI, macrophage damage occurred that resulted in significant release of the lactic dehydrogenase, beginning 2 h postinfection. This immediated macrophage cytotoxicity as abolished by pretreatment of EB with heat (5 min at 56 degrees C) and was reduced about 50% by coating EB with homologous antibody. Pretreatment of the chlamydia with heat or opsonizing antibody provides increased uptake of EB by macrophages but may contribute to increased destruction of these obligate intracellular pathogens in professional phagocytic cells.

Animals↗

Shosaikoto (kampo medicine) protects macrophage function from suppression by hypercholesterolemia.

The feeding of cholesterol-enriched diet for 2 weeks was enough to reduce nitric oxide (NO), prostaglandin E(2) (PGE(2) and interleukin-1 (IL-1) productions in thioglycollate-elicited murine macrophages. Although not showing anti-hypercholesterolemic action against ICR mice, Shosaikoto, a Kampo medicine, partially prevented the reduction of NO and IL-1 productions induced by the feeding of cholesterol-enriched diet, and completely released the reduction of PGE(2) production. These data suggest that the malfunction of macrophage induced by hypercholesterolemia may contribute to early atherogenesis and that Shosaikoto retains macrophage function to prevent the development of atherosclerosis, even though serum cholesterol is markedly increased.

Animals↗

Role of calcium in the activation of mouse peritoneal macrophages: induction of NO synthase by calcium ionophores and thapsigargin.

Bacterial lipopolysaccharide (LPS) has been recognized as one of the most potent activating signals for mouse peritoneal macrophages. In macrophages primed by interferon-gamma (IFN-gamma) or trehalose dimycolate (TDM), LPS induces NO synthase and the events associated with a high nitric oxide output: antitumor and antiparasitic activities. In the present report, it is shown that drugs (calcium ionophores or thapsigargin) which elevate the concentration of cytosolic calcium, [Ca2+]i, induce NO synthase and antitumor activities in primed macrophages, mimicking LPS action. Calcium ionophores and thapsigargin trigger NO synthase activity in macrophages primed in vivo by TDM, in thioglycollate-elicited macrophages primed in vitro by IFN-gamma, and in IFN-gamma-treated EMT6 adenocarcinoma cells. However, activation of TDM-primed macrophages by LPS does not seem to involve calcium fluxes: (i) no change in [Ca2+]i was detectable in TDM-primed macrophages loaded with Fura-2 and exposed to LPS, and (ii) activation of TDM-primed macrophages by LPS can be obtained in the presence of 4 mM EGTA. NO synthase expression is thus controlled in primed macrophages by two different pathways; calcium ionophores can replace LPS but do not act through the same intracellular cascade.

Amino Acid Oxidoreductases↗

2-[(Carboxymethyl)sulfanyl]-4-oxo-4-arylbutanoic acids selectively suppressed proliferation of neoplastic human HeLa cells. A SAR/QSAR study.

A series of twenty alkyl-, halo-, and methoxy-aryl-substituted 2-[(carboxymethyl)sulfanyl]-4-oxo-4-arylbutanoic acids were synthesized. The new compounds, called CSAB, suppressed proliferation of human cervix carcinoma, HeLa cells, in vitro in a concentration range of 0.644 to 29.48 microM/L. Two compounds exhibit antiproliferative activity in sub-micromolar concentrations. Five compounds act in low micromolar concentrations (<2 microM/L). The most active compounds exert lower cytotoxicity toward healthy human peripheral blood mononuclear cells (PBMC and PBMC+PHA) (selectivity indexes > 10). A strong structure-activity relationship, using estimated log P values and BCUT descriptors, was observed.

Antineoplastic Agents↗

Pathogenesis of murine cytomegalovirus infection: the macrophage as a permissive cell for cytomegalovirus infection, replication and latency.

Macrophages harvested from the peritoneal cavities of mice of several strains were permissive to infection with murine cytomegalovirus (MCMV). Macrophages from six mouse strains released equivalent amounts of plaque-forming virus into the culture fluids and cells from mouse strains scored similarly in numbers of infectious centres. Twenty to 50% of the infected macrophages obtained after thioglycollate activation formed infectious centres. When studied by in situ hybridization, more than 82% of infected macrophages (with or without thioglycollate activation) contained MCMV DNA. Macrophages obtained from latently infected mice were examined for their content of MCMV. Using co-cultivation assays, MCMV was frequently recovered from thioglycollate activated macrophages harvested from latently infected mice but only rarely recovered from non-activated macrophages. MCMV DNA--mouse DNA hybridization assays revealed four to seven virus genome DNA copies per 100 cells. These studies indicate that macrophages harvested from mice susceptible (BALB/cSt) or resistant (C3H) to MCMV infection replicated virus equivalently and that macrophages are a reservoir of MCMV during latent and chronic infections. Activation of macrophages may be one of the important steps leading to the exacerbation of in vivo latent infections.

Animals↗

Synthesis and antimicrobial activity of some 1,2,4-triazole-3-mercaptoacetic acid derivatives.

Ethyl 5-(2-furyl)-4-ethyl-1,2,4-triazole-3-mercaptoacetate (2), 5-(2-furyl)-4-ethyl-1,2,4-triazole-3-mercaptoacetic acid hydrazide (3) and a series of new N-alkylidene/arylidene-5-(2-furyl)-4-ethyl-1,2,4-triazole-3-mercaptoacetic acid hydrazides (4a-f) were synthesized and evaluated for in vitro antibacterial activity against Staphylococcus aureus ATCC 6538. Staphylococcus epidermidis ATCC 12228, Klebsiella pneumoniae ATCC 4352, Pseudomonas aeruginosa ATCC 1539, Escherichia coli ATCC 8739, Shigella flexneri, Salmonella typhi, Proteus mirabilis and antifungal activity against Candida albicans ATCC 10231 using the disk diffusion and microdilution methods. Compound 4f showed antibacterial activity against some bacteria. The in vitro antimycobacterial activity of the new compounds against Mycobacterium tuberculosis H37Rv was evaluated employing the BACTEC 460 radiometric system. The highest inhibition observed was 61% at > 6.25 microg/ml.

Anti-Bacterial Agents↗

Evidence for the participation of proteinases released by Candida albicans in the early killing of peritoneal macrophages in vitro.

1. We have investigated the possibility that proteinases released by Candida albicans participate in the early killing of three types of mice peritoneal macrophage (resident, thioglycollate-elicited, or Con A-activated) in vitro. 2. Phagocytic assays were performed by incubation of macrophages and C. albicans together at a 1:10 ratio for 30 min at 37 degrees C in RPMI medium buffered to pH 7.0 with 12 mM Hepes without serum. With no albumin added to the medium, the macrophages were 85% to 100% damaged and unviable, to a greater extent than expected from the proportion of phagocytic cells containing germ tubes. When 10 mg/ml of albumin was added to the medium, however, 90% of the macrophages remained viable for the 2 hours of the phagocytic assay, suggesting that albumin may have acted as a substrate for or inhibitor of proteinases released by C. albicans, thereby protecting the macrophage from the proteolytic action of the proteinases. 3. The phagocytosis of IgG-coated erythrocytes was reduced to 43% when IgG was preincubated with the supernatant from C. albicans cultures, but the addition of 10 mg/ml albumin or of 5 micrograms/ml pepstatin (an inhibitor of C. albicans acid proteinases) to the same supernatants prevented the effect on phagocytosis of IgG-coated erythrocytes. 4. These results suggest that proteinases released from C. albicans are involved in the early killing of macrophages.

Albumins↗

Phorbol myristate acetate stimulates microtubule and 10-nm filament extension and lysosome redistribution in mouse macrophages.

Phorbol myristate acetate (PMA) stimulates cell spreading and fluid-phase pinocytosis in mouse peritoneal macrophages. Colchicine (10(-5) M) and cytochalasin B (10(-5) M) abolish PMA stimulated pinocytosis but have little effect on cellular spreading (Phaire-Washington et al., 1980, J. Cell Biol., 86:634-640). We report here that PMA also alters the organization of the cytoskeleton and the distrubution of organelles in these cells. Neither control nor PMA-treated macrophages contain actin cables. PMA-treated resident thioglycolate-elicited macrophages exhibit beneath their substrate-adherent membranes many randomly distributed punctate foci that stain brightly for actin. The appearance and distribution of these actin-containing foci are not altered by colchicine (10(-5) M) or cytochalasin B (10(-5) M). In thioglycolate-elicited macrophages PMA causes the extension and radial organization of microtubules and 10-nm filaments and promotes the movement of secondary lysosomes from their perinuclear location to the peripheral cytoplasm. Depending upon the concentration of PMA used, 45-71% of thioglycolate-elicited macrophages and 32-44% of proteose-peptone-elicited macrophages and numerous lysosomes, radiating from the centrosphere region, arranged linearly along microtubule and 10-nm filament bundles. Colchicine (10(-5) M) and podophyllotoxin (10(-5) M) prevent the radial redistribution of microtubules, 10-nm filaments, and lysosomes in these cells. Cytochalasins B and D (10(-5) M) have no inhibitory effects on these processes. These findings indicate that microtubules and 10-nm filaments respond in a coordinated fashion to PMA and to agents that inhibit microtubule function; they suggest that these cytoskeletal elements regulate the movement and distribution of lysosomes in the macrophage cytoplasm.

Acid Phosphatase↗

The visna virus long terminal repeat directs expression of a reporter gene in activated macrophages, lymphocytes, and the central nervous systems of transgenic mice.

Visna virus is a lentivirus which causes a slow progressive disease involving the immune system and the central nervous system. To determine the role of the viral long terminal repeat (LTR) in targeting the virus to specific host cells and tissues, transgenic mice were constructed which contained the visna virus LTR directing expression of the bacterial gene encoding chloramphenicol acetyltransferase (CAT). Analysis of the transgenic mouse tissues for CAT activity revealed that the viral LTR was responsible, in part, for the tropism of visna virus for macrophages and the central nervous system. Expression of the LTR required the macrophage to be in an activated state both in vivo and in vitro. Thioglycolate activation of peritoneal macrophages in vivo and 12-O-tetradecanoylphorbol 13-acetate treatment in vitro induced expression of the visna virus LTR. Lymphocytes from the spleens of the transgenic mice expressed CAT activity, suggesting that visna virus was able to replicate in lymphocytes, as did human immunodeficiency virus and simian immunodeficiency virus. These studies demonstrated that the lentivirus LTR was responsible, in part, for cell and tissue tropism in vivo.

Animals↗

[Study of water-sol core-shell CdSe/CdS quantum dots].

Water-sol core/shell CdSe/CdS quantum dots (QDs) were synthesized in aqueous solution by using mercapto-acetate acid as stabilizer. The UV-Vis absorption and emission spectra were studied. The size of the SdSe-core was about 2 nm estimated by absorption edge and X-ray powder diffraction(XRD). The structure was also characterized by X-ray photoelectron spectroscopy(XPS). The intensity of luminescence of the quantum dots was greatly enhanced after the surface was modified with CdS shell. Red shift of the peak was shown in both the emission and absorption spectra.

Algorithms↗