A new monoclonal antibody (5D3-F7) which recognizes human monocyte-chemotactic protein-1 but not related chemokines. Development of a sandwich ELISA and in situ detection of producing cells

Chemokines are a superfamily of structurally related cytokines involved in leukocyte recruitment in normal and neoplastic tissues. The availability of non-cross-reacting reagents specific for each member of the C-C and C-X-C family is important for careful characterization of their in vitro and in vivo production and relevance. Here we describe a novel, highly specific, mAb against monocyte chemotactic protein-1 (MCP-1). The 5D3-F7 mAb (IgG1,kappa) recognizes human recombinant and natural MCP-1 in ELISA, immunoprecipitation and immunoblot analysis. As a source of natural MCP-1 we used the 8387 human sarcoma line which produces spontaneously MCP-1 and responds to TNF with increased expression and release. The 5D3-F7 mAb inhibited the chemotactic activity of MCP-1 for monocytes. Using the 5D3-F7 mAb and a polyclonal rabbit anti-MCP-1 serum, a sandwich ELISA was developed. In both the direct and the sandwich ELISA, the 5D3-F7 mAb recognized human MCP-1, but not the closely related C-C chemokines MCP-1, MCP-2, MCP-3, MIP-1 alpha, and RANTES and the C-X-C chemokines IL-8, gro alpha and NAP-2. In culture supernatants the sensitivity of the sandwich ELISA was approximately equal to 30 pg/ml. The sandwich ELISA permitted detection of MCP-1 in resting or cytokine-stimulated endothelial, mesothelial and Kaposi's sarcoma cells. Preliminary immunohistochemical analysis revealed production of MCP-1 by macrophage-like cells at sites of inflammation. The 5D3-F7 mAb provides a novel, highly specific reagent with which to investigate the in vitro and in vivo production and role of MCP-1.

Different signaling pathways for CD18-mediated adhesion and Fc-mediated phagocytosis. Response of neutrophils to LPS

The regulation of CD11b/CD18 adhesive and phagocytic functions on human polymorphonuclear leukocytes (PMN) in response to LPS was examined. Adhesion of PMN to surfaces coated with LPS had little or no effect on the cells, but pretreating the LPS-coated surfaces with either diluted serum or LPS-binding protein strongly enhanced their ability to bind C3bi-coated E (EC3bi), a ligand for CD11b/CD18. LPS-binding protein is known to enable responses of cells to LPS by facilitating binding of LPS to CD14. Consistent with this, we found that preformed complexes of LPS with soluble rCD14 stimulated binding of ligand by CD11b/CD18 in a concentration-dependent manner. Known agonists that stimulate CD11b/CD18 binding activity on PMN all cause simultaneous enhancement of Fc-mediated phagocytosis. However, LPS presented in complex with either serum proteins or CD14 failed to stimulate the ingestion of ElgG by PMN. The number of FcRs and their ability to bind ligand were not affected by treatment with LPS, nor were they compromised in their ability to respond to other agonists. These results suggest that LPS generates intracellular signals that alter the ability of CD11b/CD18 to bind ligand, but this alteration is not sufficient to promote phagocytosis of IgG-coated particle. This conclusion was confirmed by showing that PMN treated with LPS and serum produced a lipid with the properties of integrin-modulating factor 1: acetone extracts of these cells stimulated CD11b/CD18 adhesive capacity on PMN. However, the lipid did not enhance Fc-mediated phagocytosis. These studies suggest that CD14 affects CD11b/CD18 function by inducing the synthesis of a lipid such as IMF-1, and that this lipid affects only the binding activity, not the phagocytosis-promoting capacity of CD11b/CD18.

Different signaling pathways for CD18-mediated adhesion and Fc-mediated phagocytosis. Response of neutrophils to LPS

The regulation of CD11b/CD18 adhesive and phagocytic functions on human polymorphonuclear leukocytes (PMN) in response to LPS was examined. Adhesion of PMN to surfaces coated with LPS had little or no effect on the cells, but pretreating the LPS-coated surfaces with either diluted serum or LPS-binding protein strongly enhanced their ability to bind C3bi-coated E (EC3bi), a ligand for CD11b/CD18. LPS-binding protein is known to enable responses of cells to LPS by facilitating binding of LPS to CD14. Consistent with this, we found that preformed complexes of LPS with soluble rCD14 stimulated binding of ligand by CD11b/CD18 in a concentration-dependent manner. Known agonists that stimulate CD11b/CD18 binding activity on PMN all cause simultaneous enhancement of Fc-mediated phagocytosis. However, LPS presented in complex with either serum proteins or CD14 failed to stimulate the ingestion of ElgG by PMN. The number of FcRs and their ability to bind ligand were not affected by treatment with LPS, nor were they compromised in their ability to respond to other agonists. These results suggest that LPS generates intracellular signals that alter the ability of CD11b/CD18 to bind ligand, but this alteration is not sufficient to promote phagocytosis of IgG-coated particle. This conclusion was confirmed by showing that PMN treated with LPS and serum produced a lipid with the properties of integrin-modulating factor 1: acetone extracts of these cells stimulated CD11b/CD18 adhesive capacity on PMN. However, the lipid did not enhance Fc-mediated phagocytosis. These studies suggest that CD14 affects CD11b/CD18 function by inducing the synthesis of a lipid such as IMF-1, and that this lipid affects only the binding activity, not the phagocytosis-promoting capacity of CD11b/CD18.

Mutagenesis study at a postulated hydrophobic region near the active site of aromatase cytochrome P450

Aromatase, a cytochrome P450, catalyzes three consecutive hydroxylation reactions converting C19 androgens to aromatic C18 estrogenic steroids. On the basis of a recent computer modeling of the active site of aromatase, a hydrophobic pocket, thought to be important for the binding of some aromatase inhibitors, was predicted to extend roughly in the plane of the steroid substrate, from the position that would be occupied by its C4 and C7 atoms. Four mutants, G121A, I125N, F235N, and I474F, were generated to test this model. Although the mutagenesis results have shown that the current model for the active site of aromatase almost certainly contains a number of errors, the results are in general very satisfactory in that they suggest how the model should be altered by local realignments of the aromatase sequence with that of cytochrome P450cam. Among the mutants, I474F is the most interesting one. Its Km value for androstenedione was found to be lower than the wild type enzyme, and the kinetic analysis exhibited a substrate inhibition-like kinetic profile through an "in-cell" assay. In addition, this mutation reduces the binding affinity of an aromatase inhibitor, 4-hydroxyandrostenedione, and increases the binding affinity of two aromatase inhibitors, aminoglutethimide and CGS 16949. This study demonstrates a useful approach, by a combination of computer modeling, site-directed mutagenesis, and inhibitor binding studies, to examine the structure of the active site of aromatase and the binding nature of various aromatase inhibitors.

Tn916-generated, lipooligosaccharide mutants of Neisseria meningitidis and Neisseria gonorrhoeae

A library of Tn916-generated, tetracycline-resistant (Tc) mutants of the group B Neisseri meningitidis strain NMB was screened by using monoclonal antibodies (MAbs) that recognize structural differences in neisserial lipooligosaccharide (LOS). The LOS of parental strain NMB had a relative molecular mass of 4.5 kDa, reacted with MAbs 3F11 and 6B4 but not with MAb 4C4 or 6E4, and contained a lacto-N-neotetrose unit. Two phenotypically stable mutants, SS3 and R6, altered in LOS, were identified by colony immunoblots, electrophoresis, and Western immunoblots. The LOS of mutant SS3 was 3.4 kDa and reacted with MAbs 4C4 and 6E4 but not MAb 3E11 or 6B4. The LOS of mutant R6 was 3.1 to 3.2 kDa and reacted with MAb 6E4 but not MAb 3F11, 6B4, or 4C4. Thus, the LOSs of the R6 and SS3 mutants were predicted to contain different truncations of the core oligosaccharide. The LOS phenotype of each mutant was linked to Tc(r), as determined by transformation of the parent strain with DNA from the mutant. Southern hybridizations and single-specific-primer PCR revealed in each mutant a single truncated tn916 insertion which had lost genes required for mobilization. Tn916 mutagenesis was used to identify two distinct genetic sites in the meningococcal chromosome involved in biosynthesis of the oligosaccharide chain of LOS and to create genetically defined LOS mutants of N. meningitidis and Neisseria gonorrhoeae.

Cytokine gene expression in B-cell chronic lymphocytic leukemia: evidence of constitutive interleukin-8 (IL-8) mRNA expression and secretion of biologically active IL-8 protein

To extent our knowledge on the cytokines possibly involved in the pathophysiology of B-cell chronic lymphocytic leukemia (B-CLL), the mRNA expression of a panel of 10 cytokines was investigated on purified B-CLL cells using a reverse-transcriptase polymerase chain reaction method. Whereas negative RT-PCR signals were recorded for interleukin-1 alpha (IL-1 alpha), IL-2, IL-3, IL-4, IL-5, IL-7, tumor necrosis factor beta (TNF beta), and granulocyte-macrophage colony-stimulating factor, we detected the expression of IL-1 beta, IL-6 and TNF alpha. Furthermore, the constitutive expression of IL-8 mRNA was observed in all 17 B-CLL samples analyzed. mRNA expression was associated with the capacity of the leukemic cells to release IL-8 both constitutively (4.6 +/- 8.1 SD ng/mL) and, to a further extent, after stimulation (14.5 +/- 19.4 ng/mL). The circulating levels of IL-8 were also evaluated in 12 untreated B-CLL sera samples and the overall mean level was significantly higher (P < .01) than in normal sera. In addition, supernatants of purified B-CLL cells cultured in the presence of 12-O-tetradecanoylphorbol-13-acetate showed chemotactic activity towards neutrophils; this activity was neutralized in the presence of an anti-IL-8 antiserum. The mRNA for IL-8 was absent in five B-cell preparations from hairy cell leukemia cases and in four B-cell lines. Normal tonsil CD5+ B cells showed a low expression of IL-8 mRNA only in two of the nine preparations tested and the overall quantity of IL-8 released by these cells after 3 days' incubation was significantly lower compared with that released by B-CLL cells (0.4 +/- 0.3 and 1.6 +/- 0.9 ng/mL under basal and stimulated conditions, respectively). These findings point to an involvement of a member of the proinflammatory chemokine supergene family in human CD5+ B lymphocytes. The different IL-8 behavior observed between B-CLL cells and their normal counterpart is likely to reflect an activation state of the leukemic population.

[Pharmacokinetics and pharmacodynamics of nikethamide after endotracheal administration in dogs]

Five dogs were anaesthetized by using i.v. 30 mg.kg-1 Na-pentobarbiturate. For each dog, the tracheostomy was done and a sterized rubber tube was inserted into the tracheal tract. Through the rubber tube, 10 ml sterized nikethamide (Nik) solution was rapidly injected into the tract via 10 ml syringe and 5 forceful ventilations were performed immediately with the aid of a balloon in 30 s. Following tracheal administration (ET) of Nik 8.3 or 25 mg.kg-1 in dogs the pharmacokinetics and pharmacodynamics were studied. Blood Nik concentrations were determined by phosphorimetric method. It was shown that the absorption of Nik via tracheal tract was very quick. The blood Nik levels were 7.9 and 10.6 micrograms.ml-1 at 0.5 min and reached the maxima of 12.8 and 31.9 micrograms.ml-1, at 2.5 min, respectively, which was higher than that of i.v. Nik 8.3 mg.kg-1. Time course of Nik concentrations in plasma after ET 8.3 and 25 mg.kg-1 were fitted to a 2-compartment open model with T1/2Ka 0.48 and 0.85 min, T1/2 alpha 2.37 and 1.68 min, T 1/2 beta 114 and 130 min, AUC 1201 and 2790 micrograms.min.ml-1, bioavailability 84.7% and 65.5%, respectively. One minute after i.v. or ET Nik (8.3 or 25 mg.kg-1), respiration rate and tidal volume were increased and reached the maxima after 5 min. The recovery of respiration rate and tidal volume were proportional to the blood Nik concentration after 5-45 min with a linear regression coefficient of 0.9. The results indicated that ET Nik may be used instead of i.v. in resuscitation.

Lipooligosaccharide biosynthesis in pathogenic Neisseria. Cloning, identification, and characterization of the phosphoglucomutase gene

The lipooligosaccharide (LOS) of pathogenic Neisseria is an important factor in disease pathogenesis. Little is known about the genes involved in neisserial LOS biosynthesis. To elucidate specific LOS biosynthetic genes, we screened a Tn916 library that was constructed in Neisseria meningitidis strain NMB. This strain expresses a single LOS that has an molecular mass of 4.5 kDa and binds monoclonal antibody (mAb) 3F11. This library was screened using a mAb panel that recognizes structural differences in neisserial LOS oligosaccharides. A stable LOS mutant of strain NMB was identified which we designated NMB-R6. This mutant expressed an LOS with an molecular mass of approximately 3.1-3.2 kDa and did not bind mAb 3F11. Genomic DNA from this mutant transformed N. meningitidis strain NMB to the tetracycline resistant NMB-R6 phenotype greater than 10(-4)/recipient/micrograms of DNA. In addition, we transformed Neisseria gonorrhoeae strain 1291 (LOS phenotype molecular mass 4.5 kDa, mAb 3F11+) to the NMB-R6 LOS phenotype with N. meningitidis NMB-R6 genomic DNA. Analysis of N. gonorrhoeae strain 1291-R6 LOS by mass spectroscopy showed that the LOS oligosaccharide structure is GlcNAc-->Hep2phosphoethanolamine-->2-keto-3-deoxymannooctuloson ic acid (where Hep is heptose). Sequence analysis showed that the transposon is inserted into the 3' end of a gene that has homology to the human phosphoglucomutase (PGM) gene. Sequence comparison indicated that the putative PGM gene in N. gonorrhoeae 1291 and N. meningitidis NMB had 92% identity at the DNA level. PGM and glucokinase activity was present in cell free extracts of N. meningitidis NMB and N. gonorrhoeae strain 1291. N. meningitidis NMB-R6 and N. gonorrhoeae strain 1291-R6 had no detectable PGM activity, whereas glucokinase activity was similar to the wild type strains. PGM activity can be reconstituted in N. meningitidis strain NMB-R6 by transformation with the cloned PGM gene. SDS-polyacrylamide gel electrophoresis demonstrated that NMB-R6 transformed with the PGM gene expressed the 3F11+, 4.5-kDa LOS of the parent NMB strain. The inability of N. meningitidis NMB-R6 and N. gonorrhoeae strain 1291-R6 to convert glucose 6-phosphate to glucose 1-phosphate results in the truncated LOS phenotype expressed by these mutants.

Receptors and transduction pathways for monocyte chemotactic protein-2 and monocyte chemotactic protein-3. Similarities and differences with MCP-1

MCP-2 and MCP-3 are recently identified members of the Cys-Cys chemokine family with high sequence similarity with MCP-1 (62% and 71%, respectively). The present study was aimed at defining receptor usage and signal transduction pathways of MCP-2 and MCP-3 in human monocytes in comparison with MCP-1. MCP-2 and MCP-3 induced migration of monocytes with a typical bell-shaped curve and maximal response at 10 and 50 ng/ml, respectively. The maximal response elicited by MCP-2 and MCP-3 was lower (approximately 60%) than that of MCP-1. Pertussis toxin (PTox) inhibited the chemotactic activity of MCP-3 and MCP-1 (IC50 = 6.2 and 4.4 ng/ml, respectively), whereas cholera toxin (CTox) had little effect on these two chemokines (IC50 &gt; 1000 ng/ml). In contrast, MCP-2-induced chemotaxis was blocked by CTox (IC50 = 75 ng/ml) and relatively unaffected by PTox. MCP-3 and MCP-1 induced a rapid increase in intracellular Ca2+ concentration, whereas MCP-2, in the range of concentrations active on chemotaxis, did not. MCP-1-, MCP-2-, and MCP-3-induced chemotactic responses were blocked by C-I, a serine/threonine kinase inhibitor, and by genistein, a tyrosine kinase inhibitor, with the MCP-2 response being more sensitive than those induced by MCP-1 and MCP-3. MCP-1 and MCP-3 rapidly induced arachidonic acid release whereas MCP-2 was ineffective. MCP-1 and MCP-3 cross-desensitized with each other in terms of Ca2+ transients and displaced with a comparable efficiency labeled MCP-1 from human monocytes. On the other hand, MCP-2 did not cross-desensitize with MCP-1 and MCP-3 and only partially (20%) displaced labeled MCP-1. Thus, in spite of high sequence similarity, MCP-2 differed considerably from MCP-1 and MCP-3 in terms of sensitivity to CTox and PTox, arachidonate and calcium mobilization, and capacity to compete for labeled MCP-1.

Receptors and transduction pathways for monocyte chemotactic protein-2 and monocyte chemotactic protein-3. Similarities and differences with MCP-1

MCP-2 and MCP-3 are recently identified members of the Cys-Cys chemokine family with high sequence similarity with MCP-1 (62% and 71%, respectively). The present study was aimed at defining receptor usage and signal transduction pathways of MCP-2 and MCP-3 in human monocytes in comparison with MCP-1. MCP-2 and MCP-3 induced migration of monocytes with a typical bell-shaped curve and maximal response at 10 and 50 ng/ml, respectively. The maximal response elicited by MCP-2 and MCP-3 was lower (approximately 60%) than that of MCP-1. Pertussis toxin (PTox) inhibited the chemotactic activity of MCP-3 and MCP-1 (IC50 = 6.2 and 4.4 ng/ml, respectively), whereas cholera toxin (CTox) had little effect on these two chemokines (IC50 > 1000 ng/ml). In contrast, MCP-2-induced chemotaxis was blocked by CTox (IC50 = 75 ng/ml) and relatively unaffected by PTox. MCP-3 and MCP-1 induced a rapid increase in intracellular Ca2+ concentration, whereas MCP-2, in the range of concentrations active on chemotaxis, did not. MCP-1-, MCP-2-, and MCP-3-induced chemotactic responses were blocked by C-I, a serine/threonine kinase inhibitor, and by genistein, a tyrosine kinase inhibitor, with the MCP-2 response being more sensitive than those induced by MCP-1 and MCP-3. MCP-1 and MCP-3 rapidly induced arachidonic acid release whereas MCP-2 was ineffective. MCP-1 and MCP-3 cross-desensitized with each other in terms of Ca2+ transients and displaced with a comparable efficiency labeled MCP-1 from human monocytes. On the other hand, MCP-2 did not cross-desensitize with MCP-1 and MCP-3 and only partially (20%) displaced labeled MCP-1. Thus, in spite of high sequence similarity, MCP-2 differed considerably from MCP-1 and MCP-3 in terms of sensitivity to CTox and PTox, arachidonate and calcium mobilization, and capacity to compete for labeled MCP-1.

Synergism between platelet activating factor and C-C chemokines for arachidonate release in human monocytes

Monocyte Chemotactic Protein(MCP)-1 and other members of the C-C branch of the chemokine superfamily (RANTES, MIP1 alpha/LD78, and MCP-3) induced, at chemotactic concentrations, the release of [3H]arachidonic acid in prelabeled human monocytes. Arachidonate release was potentiated (2 to 4 fold) in the presence of platelet activating factor (PAF). PAF effect was blocked by a specific receptor antagonist, WEB 2187, and was not present when inactive analogs, PAF inactive enantiomer, or lysoPAF were used. Thus, the synergistic action of PAF with C-C chemokines, in terms of arachidonate release and chemotaxis, is specific for this alkylphospholipid and is receptor mediated. Reciprocal potentiation of PAF and C-C chemokines may be important at sites of inflammation.

Effect of one or more footshocks on spleen and blood lymphocyte proliferation in rats

The effect of 1 (1.6 mA, 5 s), 3, 8, or 16 inescapable footshocks on the response of spleen and peripheral blood lymphocytes to nonspecific mitogenic stimulation and plasma corticosterone levels was studied in adult Lewis male rats. One footshock suppressed mitogenic activity in the spleen and this effect was comparable to 3, 8, and 16 footshocks. The maximum suppression to nonspecific mitogenic stimulation in the spleen was observed at 1 and 10 min after exposure to a single footshock and suppression of the mitogenic responses in the spleen persisted for at least 60 min. In contrast, immediately after a single footshock peripheral blood lymphocyte mitogenic function was not suppressed but instead was significantly enhanced. A significant suppression of mitogenic responsiveness of blood lymphocytes occurred 30 min after exposure to a single footshock and at 60 min the blood mitogenic activity did not differ from the home cage controls. Eight footshocks produced a significant suppression of mitogenic responses in the blood and 16 footshocks produced the greatest suppression of blood mitogenic function. These data suggest that 1 brief footshock caused activation of the HPA axis and sympathetic nervous system and resulted in significant alteration of the immune system. We suggest that noncomplex models of short-term stress may provide for a better understanding of the mechanisms underlying the development of stress reactions in the CNS and the periphery.

Rapid induction of arachidonic acid release by monocyte chemotactic protein-1 and related chemokines. Role of Ca2+ influx, synergism with platelet-activating factor and significance for chemotaxis

Monocyte Chemotactic Protein-1 (MCP-1), a member of the Cys-Cys branch of the chemokine superfamily, induced a mepacrine- and manoalide-sensitive increase in the release of [3H]arachidonic acid from prelabeled human monocytes and monocytic THP-1 leukemic cells. The effect was rapid (<30 s), reached maximum at optimal chemotactic concentrations, and was completely blocked by pretreatment of monocytes with Bordetella pertussis toxin. A specific antiserum and heat inactivation blocked the induction of arachidonic release by MCP-1. No [3H]arachidonic acid release was observed in the absence of Ca2+ influx (5 mM EGTA or 5 mM Ni2+) or in monocytes loaded with a Ca(2+)-buffering agent. However, using ionophore-permeabilized monocytes and controlled intracellular Ca2+ concentration it was possible to dissociate MCP-1-induced Ca2+ influx from [3H]arachidonic acid release. Thus, the MCP-1-induced increase in [Ca2+]i is necessary but not sufficient for arachidonic acid accumulation. Phospholipase A2 inhibitors (mepacrine, p-bromophenacyl bromide, and manoalide) blocked monocyte polarization and chemotaxis induced by MCP-1. The related Cys-Cys chemokines RANTES and LD78/MIP1 alpha also induced a rapid release of [3H]arachidonic acid, and their chemotactic activity was blocked by phospholipase A2 inhibitors. Brief (5 min) pretreatment of monocytes with platelet-activating factor amplified MCP-1-induced arachidonic acid release and, at MCP-1 suboptimal concentrations, synergized in inducing monocyte migration. Since MCP-1 and platelet-activating factor are induced concomitantly by inflammatory cytokines in monocytes and endothelial cells, we speculate that the observed synergism may have in vivo relevance. The results presented here show that the Cys-Cys chemokines MCP-1, LD78/MIP1 alpha, and RANTES cause rapid release of arachidonic acid in monocytes and that this may be important in inducing monocyte chemotaxis.

[Clinical analysis of 24 cases of chordomas in the skull base]

Chordoma is a rare neoplasm which arises from the embryonic remnant of the notochord. The paper reported 24 cases of chordomas in the skull base. According to symptoms, signs, imaging features, operation findings, the original places and the expansive directions of the tumor, they were divided into four clinical types: sellar, clival, occipito-temporal and extent. The choices of surgical approaches were suggested on these types. They are difficult to remove because of their deep site, limit operative field and close to the important vessels, nerves and brain, and they recur frequently after operation.

Schistosomiasis control in China

Well-organized programmes combining local involvement and major government projects have been successful in controlling schistosomiasis to a large extent in China. The task is far from complete, however, especially in some lacustrine and mountainous areas, where conditions are highly favourable for the vector snails, and difficult to modify. A long-term programme of health education, medical care and infrastructure development is needed.

Exposure to physical and psychological stressors elevates plasma interleukin 6: relationship to the activation of hypothalamic-pituitary-adrenal axis

Interleukin 6 (IL-6) is a pleiotropic cytokine produced by the cells of immune and nonimmune origin. Increased production of IL-6 is associated with disturbances of homeostasis, such as trauma, sepsis, or inflammatory diseases. Endotoxemia, tissue injury, or immune inflammatory reactions as well as physical or psychological stress are known to cause increased production of IL-6. We have confirmed this by showing that rats exposed to electric footshock, physical restraint, or a conditioned aversive stimulus have increased levels of plasma IL-6. Interestingly, the kinetics of the increase in plasma IL-6 resembled that of increase in plasma corticosterone. As no detectable endotoxin was found in the plasma samples from stressed and nonstressed rats and there is no evidence of tissue damage and inflammation in situations of restraint or conditioned aversive stimulus, a nonimmune origin of IL-6 is possible. Thus, the releasing of IL-6 into plasma may be under the regulation of neural and endocrine responses to stress. This hypothesis is supported by the decreased production of IL-6 in cultures of splenic cells and peripheral blood mononuclear cells from stressed animals. Furthermore, substantial attenuation of increased plasma IL-6 was achieved by adrenalectomy but not by pretreatment with the beta-receptor antagonist propranolol. The important role of the adrenal gland in the IL-6 response to stress suggests that increased plasma IL-6 may be part of the hormonal responses to stress. As IL-6 induces acute-phase proteins along with glucocorticoids from the adrenal, and regulates the secretion of various hormones from neuroendocrine and endocrine tissues, it is possible that stress-induced increase in plasma IL-6 contributes to the maintenance of homeostasis.

Use of aromatase (CYP19) metabolite ratios to characterize electron transfer from NADPH-cytochrome P450 reductase

Aromatase catalyzes the conversion of 4-androstene-3,17-dione to estrogen with the concomitant formation of the minor metabolites 4-androstene-19-hydroxy-3,17-dione(19-hydroxyandrostenedione) and 4-androstene-3,17,19-trione(19-oxoandrostenedione). Microsomes of chinese hamster ovary (CHO) cells expressing human aromatase were isolated to investigate androstenedione metabolism. Relatively greater amounts of the minor metabolites result after limitation of electron flux from NADPH-cytochrome P450 reductase to aromatase. Substitution of NADH for NADPH or limitation of NADPH availability increased minor metabolite formation relative to estrogen formation. Similar changes in metabolite ratios were observed when metabolism was conducted either at high pH (8.3) or in the presence of n-alcohols in the range of 5-200 mM alcohol concentrations. However, conditions of low pH (5.5) or high ionic strength (1 M KCl) resulted in minor changes in metabolite ratios, suggesting little or no effect on electron flux between NADPH-cytochrome P450 reductase and aromatase. Theoretical molar ratios of the resulting metabolites were predicted using a reaction scheme assuming sequential substrate oxidations without reversible intermediate release from the aromatase active site. This model was supported by a close agreement between theoretical and experimental metabolite ratios for a broad range of NADPH concentrations. The results indicate that metabolite ratios provide a sensitive indicator of aromatase-oxidoreductase interactions in the microsomal environment.

Comparison of Shams' test for rectal mucus to an immunological test for fecal occult blood in large intestinal carcinoma screening. Analysis of a check-up of 6480 asymptomatic subjects

The sugar moiety detected from rectal mucus by the Galactose oxidase-schiff (Shams' test) is considered a substitutive test for immunological fecal occult blood test (FOBT) in screening colorectal carcinoma. Two strategies of screening were applied in 6480 subjects over 40 years of age, and 130 cm flexible colonoscope used for sigmoidoscopy or pancolonoscopy. Of them, 3820 were taken for immune FOBT (SPA test) and Shams' test. Only those who showed positive tests were chosen for 60 cm flexible sigmoidoscopy, while another 2660 subjects for both sigmoidoscopy and tests at the same time. Additionally, 130 cm flexible pancolonoscopy was carried out in 103 individuals with positive Shams' test for evaluating the false positive rate. Shams' test showed a sensitivity of 85.7% for colorectal cancer, 47.1% for adenomas in preselected patients, while the positive rate of SPA test were 90.5% and 41.2% respectively. In 3820 asymptomatic subjects undergoing sequential screening (aged 45 years and higher), Shams' test showed 9.1% positive, SPA showed 11.2% and 620 (16.2%) subjects were selected for sigmoidoscopy based on their positive galactose oxidase result or positive FOBT result. Two early stage carcinomas and 33 adenomas (0.32% and 4.2% respectively in sigmoidoscopy) were found. Another 2 660 subjects were taken for sigmoidoscopy screening. Four carcinomas and 78 adenomas were found. Of them, only two carcinoma (50%) and 17 (21.8%) or 22 (28.2%) adenomas were positive in Shams' or SPA test. But both tests combined in screening showed a rate of 61.3% in adenomas and 75.0% in cancers. 103 subjects with positive Shams' test were taken for pancolonoscopy. 82.5% showed no lesions.(ABSTRACT TRUNCATED AT 250 WORDS)

Community-based rehabilitation: does it change community attitudes towards people with disability?

To achieve the goal of 'Health for All by the Year 2000' the World Health Organization (WHO) adopted an approach to rehabilitation described as community-based rehabilitation (CBR). A major objective of CBR is to develop positive community attitudes towards people with disabilities. To determine whether this objective can be achieved, post hoc measurement of attitudes towards people with disabilities was carried out in a community in which CBR had been established and in a control community. It is shown that both groups exhibited neutral attitudes. The community exposed to CBR obtained a mean attitude score significantly (p < 0.001) closer to the positive end of the scale than did the control community. It is concluded that communities in which CBR is being carried out develop more favourable attitudes towards people with disabilities than do those in which no such programme has been implemented.

Basic fibroblast growth factor enhances the growth of postnatal neostriatal GABAergic neurons in vitro

Basic fibroblast growth factor (bFGF) significantly enhances the short-term survival of embryonic striatal neurons in vitro but has little effect on the outgrowth of striatal cells compared to neurons from other brain regions. Studies in our laboratory have shown that bFGF protects postnatal striatal cells in vitro from NMDA receptor-induced neurotoxicity. We therefore examined the effects of bFGF on the outgrowth of GABA-containing cells taken from the postnatal (Day 1) caudate-putamen and cultured for up to 3 weeks. In control cultures GABAergic neurons formed three populations based on somatic size and developed the cytoarchitectural features characteristic of dendrites, spines, and axons. In the presence of bFGF (6 pM continuously from the day of plating), small- and medium-sized GABAergic neurons showed significant increases compared to untreated controls in axon-like growth (axon length) at 6 days in culture and in both axon- and dendrite-like neurite growth (axon length and branch order, number of primary dendrites, dendrite length, and dendritic branch order) at 13 and 17 days in culture. Large GABAergic neurons were unaffected by treatment with bFGF. Striatal GABAergic neurons exposed to nerve growth factor (10 ng/ml) were not different from untreated controls. Neuron survival was also unaffected by bFGF treatment at all days in culture examined. Other observations suggested that the neurotrophic effects of bFGF were mediated by a direct action of the growth factor on striatal neurons and not glial cells. First, glial cells (identified by the immunohistochemical localization of glial fibrillary acidic protein) were unaffected by bFGF treatment at the low concentration (6 pM) used to enhance neurite growth, but did significantly proliferate at higher concentrations of bFGF (6 nM). Second, immunoreactive bFGF receptor protein was localized predominantly to the somata and processes of striatal neurons and not to glial cells in the cultures. Finally, when neurons from control cultures were briefly exposed (1 to 4 h) to bFGF at concentrations which were neurotrophic, a marked elevation in the immediate early gene protein c-fos was observed by immunohistochemistry in the nuclei of neurons, including GABAergic cells.(ABSTRACT TRUNCATED AT 400 WORDS)

Aromatase gene is amplified in MCF-7 human breast cancer cells

The levels of the aromatase gene and its expression in MCF-7 human breast cancer cells and seven additional cultured cells were investigated. Using normal human foreskin fibroblasts as the control, the aromatase gene appeared to be amplified in MCF-7 cells as shown by Southern and DNA slot blot analyses utilizing human placental aromatase cDNA as the probe. However, the promoter I.1 and the first exon of the aromatase gene were not amplified in MCF-7 cells based on results obtained from DNA slot blot analysis using oligonucleotide probes having sequences derived from those regions of human aromatase gene. Aromatase was expressed at a very low level in this cell line as indicated by Northern blot analysis to measure the level of aromatase mRNA, immunoprecipitation analysis to measure the level of aromatase protein, and aromatase activity measurement. Furthermore, nucleotide sequence analysis of the aromatase cDNA obtained from MCF-7 cells by PCR techniques, revealed no sequence difference from that of the enzyme expressed in placenta. These results lead us to conclude that the expression of aromatase in MCF-7 cells is under the control of an unusual promoter and aromatase gene expression is repressed at the transcriptional level in these cells.

Porcine pancreatic islets: isolation, microencapsulation, and xenotransplantation

To provide a plentiful source of pancreatic islets for future clinical transplants into diabetic patients, we have developed a simple and reliable method to isolate porcine islets of a high degree of purity. Porcine pancreata were perfused and digested with collagenase, and the islets were then purified on dextran density gradients. In order to avoid any damage to the islets, no mechanical devices nor any strenuous treatment was employed. As many as 5 x 10(5) islets were isolated from a single porcine pancreas. Islets were encapsulated in alginate-polylysine-alginate membranes with the aid of an electrostatic droplet generator. In vitro studies demonstrated that the isolated islets secreted insulin in response to glucose and 3-isobutyl-L-methylxanthine (IBMX) challenge for at least 4 weeks. Perifusion studies showed that the kinetics of insulin release from the encapsulated islets was similar to that exhibited by free islets. In in vivo studies, 18 diabetic BALB-c mice were transplanted with 1,500-2,500 encapsulated islets each. In 13 recipients, the diabetic condition was reversed for at least 85 days. When capsules were removed from 2 transplant recipients, their diabetic condition quickly recurred.

Daunorubicin uptake by leukemic cells: correlations with treatment outcome and mdr1 expression

The in vitro daunorubicin (DNR) cell uptake was investigated by flow cytometry in K562/DOX resistant cell line and in 42 patients with acute myeloid leukemia (AML). The proportion of cells able to take up DNR was higher in untreated patients (50% +/- 30) than in previously treated patients (31% +/- 31) (p = 0.04). We noted a good correlation (p < 0.001) between the drug uptake after exposure to 0.1 microM DNR and achievement of complete remission. Cyclosporin A (CsA, 1 microgram/ml) and verapamil (5 micrograms/ml), but not cefoperazone (10 mM), completely reversed (CsA) or partially reversed (verapamil) the DNR efflux from K562/DOX mdr1(+) cell line. CsA significantly increased (p < 0.01) the DNR uptake of fresh leukemic cells, but not consistently, with no relationship to mdr1 mRNA cellular level. This absence of correlation was explained by the fact that several patients with no mdr1 gene expression exhibited a low in vitro DNR uptake, showing that the MDR phenotype is not the only mechanism responsible for the alteration of DNR pharmacokinetics in AML.

Catalytic efficiency of expressed aromatase following site-directed mutagenesis

Mutant aromatase cytochrome P-450s, expressed in CHO cells after transfection with cDNAs, have been characterized in terms of their catalytic efficiencies. After solubilization from microsomes, specific aromatase P-450 content of wild-type and mutants Pro308Phe, Asp309Asn, Asp309Ala and Phe406Arg was quantitated by a sandwich enzyme-linked immunosorbent assay (ELISA). Microsomal aromatase activity was determined by the 3H-water method using [1 beta-3H]androstenedione as substrate. Estimations of the actual turnover rate (catalytic efficiency) were derived from the combined data. The P-450 content in the mutants varied but was always less than that in the wild type. Hence, the decreases in the Vmax observed in the mutant enzymes did not correlate completely with reductions in catalytic effectiveness. In recent studies on the structure-function relationship of aromatase cytochrome P-450, the observed reduction of enzyme activity in terms of Vmax following site-directed mutagenesis led to the assumption that there was a corresponding loss of catalytic effectiveness. The present study reveals that a lower P-450 content can contribute significantly to decreasing catalytic activity in the mutants. In fact, in mutant Phe406Arg which exhibited virtually no catalytically active aromatase, the specific P-450 content was below the detectable level. Because of its location, the result of this latter mutation could be a major structural perturbation of the heme-binding property. Thus, interpretation of losses and reductions in aromatase activity resulting from single amino-acid replacement should take into account changes in the specific content of aromatase cytochrome P-450.

Cerebellar control of expiratory activities of medullary neurons and spinal nerves

Expiratory-related activities of spinal nerves are augmented after stimulation of the infracerebellar nucleus of the cerebellum. These stimulations alter neither inspiratory spinal neural activities nor inspiratory and expiratory laryngeal neural activities. It was hypothesized that efferents from the infracerebellar nucleus impinge on spinal motoneurons by a pathway that bypasses the medulla. In decerebrate, paralyzed, and vagotomized cats, phrenic and expiratory triangularis sterni activities and activities of medullary respiratory neurons were recorded. During infracerebellar stimulation, activities increased for expiratory bulbospinal neurons and neurons with tonic discharge patterns. After unilateral ablation of the infracerebellar nucleus by kainic acid, triangularis sterni discharge was eliminated and activities of expiratory bulbospinal neurons continued at reduced frequencies. Stimulations of the anterior interposed nucleus caused both inspiratory and expiratory activities to increase, whereas no systematic changes followed stimulations of the vermis. Results establish that at least a portion of the changes in expiratory activities of spinal motoneurons after perturbations of the infracerebellar nucleus occurs secondarily to changes in activities of medullary neurons. The possibility of separate cerebellar projections to medullary and spinal neurons is discussed.

Increased production of TGF-beta and Il-6 by aged spleen cells

Aging is accompanied by a progressive decline in immunity in every species that has been studied. Despite its ubiquity, the causes of immunosenescence are unknown. Transforming growth factor beta (TGF-beta) is a cytokine with potent immunosuppressive properties. Cells from aged mice produce increased levels of TGF-beta in vitro along with similar increases in interleukin 6 (Il-6), a cytokine which is immunosuppressive at elevated concentrations. Il-6 does not upregulate TGF-beta production, but high concentrations of Il-6 increase the percentage of cells expressing the TGF-beta receptor. Increased TGF-beta production and Il-6-induced upregulation of the TGF-beta receptor may be factors contributing to age-associated immunosuppression.

Structure-function studies of human aromatase

Site-directed mutagenesis experiments have been carried out to determine the structure-function relationship of human aromatase. By sequence comparison, the region in aromatase that corresponds to the distal helix of cytochrome P-450cam has been identified to be Gln-298 to Val-313. Eight aromatase mutants with changes in this region, i.e. C299A, E302L, P308F, D309N, D309A, T310S, T310C, and S312C, have been generated using a mammalian cell stable-expression system. The results from site-directed mutagenesis studies indicate that the region containing Gln-298 to Val-313 is indeed a very important part of the active site of aromatase. The catalytic properties of P308F, D309N, and D309A have been examined in detail and are discussed. Active site-directed labeling is also an important approach to investigate the structure-function relationship of aromatase. HPLC-linked electrospray mass spectrometry is indicated as a useful technique for the characterization of active site-directed probe-modified enzyme. The mass spectral analysis of aromatase suggests that aromatase is glycosylated.

Effect of androstenedione on growth of untransfected and aromatase-transfected MCF-7 cells in culture

Aromatase is present in human breast tumors and in breast cancer cell lines suggesting the possibility of in-situ estrogen production via the androstenedione to estrone and estradiol pathway. However, proof of the biologic relevance of aromatase in breast cancer tissue requires the demonstration that this enzyme mediates biologic effects on cell proliferation. Accordingly, we studied the effects of the aromatase substrate, androstenedione, on the rate of proliferation of wild-type and aromatase-transfected MCF-7 breast cancer cells. Androstenedione did not increase cell growth in wild-type MCF-7 cells which contained relatively low aromatase activity and produced 4-fold more estrone than estradiol. In contrast, aromatase-transfected cells contained higher amounts of aromatase, produced predominantly estradiol, and responded to androstenedione with enhanced growth. An aromatase inhibitor fadrozole hydrochloride, blocked the proliferative effects of androstenedione providing evidence for the role of aromatase in this process. As further evidence of the requirement for aromatase, cells transfected with the neomycin resistance expression plasmid but lacking the aromatase cDNA did not respond to androstenedione. These studies provide evidence that aromatase may have a biologic role for in-situ synthesis of estrogens in breast cancer tissue.

Expression of beta 2-adrenergic receptor mRNA in peripheral lung in asthma and chronic obstructive pulmonary disease

Previous studies have indicated an increased number of beta 2-adrenergic receptors (beta 2AR) on bronchial smooth muscle in fatal asthma. This study evaluates the utility of autopsy lung for studies of gene expression and examines the hypothesis that increased expression of beta 2 AR mRNA in peripheral lung underlies the increased receptor number reported in central airways in fatal asthma. beta 2AR mRNA levels have been quantitated using the ribonuclease protection assay on RNA from peripheral lung obtained both at autopsy and thoracotomy from subjects with normal lungs as well as subjects with asthma or chronic obstructive pulmonary disease (COPD). Glucocorticosteroid and serum induction of beta 2AR mRNA in human epidermoid carcinoma A431 cells, which display a high abundance of beta 2AR receptors, was also examined to provide aliquots of RNA containing relatively high levels of beta 2AR mRNA for use as positive controls and internal standards. In A431 cells maintained after confluence in serum-free media for 72 h, maximal beta 2AR mRNA levels in response to 10% fetal bovine serum were 85% of maximal levels following serum plus 10 microM dexamethasone. Both autopsy and resected lung yielded undegraded RNA with a similar relative abundance of beta 2AR mRNA. Although geometric mean beta 2AR mRNA levels were similar in all three patient groups, relatively high levels were observed in resected lung in a subpopulation of subjects with mild or moderate asthma but not in autopsy lung from subjects with severe asthma. High levels of beta 2AR mRNA, presumably reflecting lung growth or asthma, were demonstrated in peripheral lung of a 4-yr-old child with asthma.(ABSTRACT TRUNCATED AT 250 WORDS)

Immunohistochemical localization of the D1 dopamine receptor in rat brain reveals its axonal transport, pre- and postsynaptic localization, and prevalence in the basal ganglia, limbic system, and thalamic reticular nucleus

D1 dopamine receptor localization was examined by immunohistochemistry using a polyclonal anti-peptide antibody which (i) immunoprecipitated a protein fragment encoded by a D1 receptor cDNA and (ii) on Western blots of solubilized striatal and hippocampal membranes recognized two proteins of approximately 50 kDa and 75 kDa, corresponding to reported sizes of D1 receptor proteins. Immunoreactivity overlapped with dopamine-containing pathways, patterns of D1 receptor binding, and mRNA expression. Staining was concentrated in prefrontal, cingulate, parietal, piriform, entorhinal, and hippocampal cortical areas and subcortically in the basal ganglia, amygdala, septal area, substantia inominata, thalamus, hypothalamus, and neurohypophysis. Prominent labeling was seen in the thalamic reticular nucleus, a region known to integrate ascending basal forebrain inputs with thalamocortical and corticothalamic pathways and in fiber bundles interconnecting limbic areas. In striatal neuropil, staining appeared in spines (heads and necks), at postsynaptic sites in dendrites, and in axon terminals; in the pars reticulata of the substantia nigra, labeling was prevalent in myelinated and unmyelinated axons and dendrites. These data provide direct evidence for the regional and subcellular distribution of D1 receptor protein in the brain and for its pre- and postsynaptic localization in the basal ganglia. The prominent immunoreactivity seen in the limbic system and thalamic reticular nucleus supports an important role for this receptor subtype in mediating integrative processes involved with learning, memory, and cognition.

Kinetic properties of aromatase mutants Pro308Phe, Asp309Asn, and Asp309Ala and their interactions with aromatase inhibitors

Mutant forms of aromatase cytochrome P-450 bearing modifications of amino acid residues Pro308 and Asp309 and expressed in transfected Chinese hamster ovary cells were subjected to kinetic analysis and inhibition studies. The Km for androstenedione for expressed wild type (11.0 +/- 0.3 nM SEM, n = 3) increased 4-, 25- and 31-fold for mutants Pro308Phe, Asp309Asn and Asp309Ala, respectively. There were significant differences in sensitivity among wild type and mutants to highly selective inhibitors of estrogen biosynthesis. 4-Hydroxyandrostenedione (4-OHA) a strong inhibitor of wild type aromatase activity (IC50 = 21 nM and Ki = 10 nM), was even more effective against mutant Pro308Phe (IC50 = 13 nM and Ki = 2.8 nM), but inhibition of mutants Asp309Asn and Asp309Ala was considerably less (IC50 = 345 and 330 nM and Ki = 55 and 79 nM, respectively). Expressed wild type aromatase and Pro308Phe aromatase were strongly inhibited by CGS 16949A (IC50 = 4.0 and 4.6 nM, respectively) whereas mutants Asp309Asn and Asp309Ala were markedly less sensitive (IC50 = 140 and 150 nM, respectively). CGS 18320B produced similar inhibition. Kinetic analyses produced Ki = 0.4 nM for CGS 16949A inhibition of wild type versus 1.1, 37 and 58 nM, respectively, against Pro308Phe, Asp309Asn and Asp309Ala. The results demonstrate significant changes in function resulting from single amino acid modifications of the aromatase enzyme. Our data indicate that mutation in Asp309 creates a major distortion in the substrate binding site, rendering the enzyme much less efficient for androstenedione aromatization. The substitution of Pro308 with Phe produces weaker affinity for androstenedione in the substrate pocket, but this alteration favors 4-OHA binding. Similarly, mutant Pro308Phe exhibits a slightly greater sensitivity to inhibition by CGS 18320B than does the wild type. These results indicate that residues Pro308 and Asp309 play critical roles in determining substrate specificity and catalytic capability in aromatase.

Functional domains of aromatase cytochrome P450 inferred from comparative analyses of amino acid sequences and substantiated by site-directed mutagenesis experiments

Several functional domains, especially the active site regions, in aromatase cytochrome P450 were inferred by alignment of amino acid sequences of the enzyme from five species, human, rat, mouse, chicken, and trout, and that of Pseudomonas putida cytochrome P450cam, whose x-ray structure has been determined (Poulos, T.L., Finzel, B.C., and Howard, A.J. (1987) J. Mol. Biol. 195, 687-700). The predicted functions of these domains have been evaluated by site-directed mutagenesis. Eighteen mutants, including seven new mutants, have been generated in this laboratory. The seven newly prepared mutants are Q123E, Q123H, T310S, T310C, R365K, R365A, and N delta 20 (a mutant without the first 20 amino acids). The preparation and characterization of these new mutants are described. The structural model described in this paper should be very useful for future structure-function studies of aromatase by site-directed mutagenesis.

Effect of exogenous sialylation of the lipooligosaccharide of Neisseria gonorrhoeae on opsonophagocytosis

Serum-sensitive Neisseria gonorrhoeae strains become serum resistant when grown in the presence of a sialic acid precursor, cytidine monophospho-N-acetylneuraminic acid. We examined the abilities of human neutrophils to phagocytose sialylated and nonsialylated gonococci and observed a decrease in the complement-dependent phagocytosis of sialylated gonococci compared with that of nonsialylated gonococci (50.7 versus 25.9% survival at 30 min). This decrease in opsonophagocytosis after sialylation may contribute to the pathogenicity of gonococcal infections.

[Effect of poly-saccharide sulphate on thixotropic properties of whole blood in patients with cerebral thrombosis]

Using Low shear 30 rheometer, we measured the thixotropic parameters of blood from 30 patients suffering from cerebral thrombosis. The result showed that the yield stress (tau 0), non-Newtonian contribution of viscosity (eta s-mu) and viscosity of plasma (eta p) were significantly higher than those in the control group. Those patients were randomly divided into two groups. Each group included 15 patients. The patients in group 1 and group 2 were treated with poly-saccharide sulphate (PSS) and DX40 respectively by intravenous drip for 14 days. The results showed that tau 0, A, (eta s-mu) were significant decreased in group 1 after treatment, but no significantly change in the thixotropic parameters was found in group 2 after treatment. The total curative rate in group 1 was higher than that in group 2. These results suggest that the patients with cerebral thrombosis had evidently increased degree of RBC aggregation. PSS could decrease the aggregation of RBC more significantly than DX40 did. It was probably one of the reasons why the therapeutic effect of PSS on cerebral thrombosis was better than that of DX40.

Reductions of neural activities to upper airway muscles after elevations in static lung volume

We evaluated the hypothesis that the tonic discharge of pulmonary stretch receptors significantly influences the respiratory-modulated activities of cranial nerves. Decerebrate and paralyzed cats were ventilated with a servo-respirator, which produced changes in lung volume in parallel with integrated phrenic activity. Activities of the facial, hypoglossal, and recurrent laryngeal nerves and nerves to the thyroarytenoid muscle and triangularis sterni were recorded. After a stereotyped pattern of lung inflation, tracheal pressure was held at 1, 2, 4, or 6 cmH2O during the subsequent ventilatory cycle. Increases in tracheal pressure caused progressive reductions in both inspiratory and expiratory cranial nerve activities and progressive elevations in triangularis sterni discharge; peak levels of phrenic activity declined modestly. Similar changes were observed in normocapnia and hypercapnia. We conclude that the tonic discharge of pulmonary stretch receptors is an important determinant of the presence and magnitude of respiratory-modulated cranial nerve activity. This reflex mechanism may maintain upper airway patency and also regulate expiratory airflow.

5-(p-aminophenyl)-1,2,3,4-tetrahydroxypentane, a structural component of the modified folate in Sulfolobus solfataricus

The partial characterization of the modified folate present in Sulfolobus solfataricus has been carried out. Separation of ethanol-water extracts of these cells on a DEAE-Sephadex column led to the isolation of a small amount of intact oxidized cofactor, which, when subjected to reductive cleavage with Zn-HCl, produced 6-methylpterin. This indicated that the modified folate in these cells contained a nonmethylated pterin linked, via a methylene group at the C-6 position of the pterin, to an arylamine, as is found in folate. Oxidative cleavage of intact reduced cofactor produced pterin and a single arylamine. The azo dye derivative of this arylamine was prepared and purified by chromatography on a Bio-Gel P-6 column. The resulting purified compound was shown to be readily hydrolyzed in dilute acid to the azo dye derivative of 5-(p-aminophenyl)-1,2,3,4-tetrahydroxypantane, which was, in turn, readily cleaved to 5-(p-aminophenyl)-1,2,3,4- tetrahydroxypentane by Zn-HCl reduction. The stereochemistry of the resulting 5-(p-aminophenyl)-1,2,3,4-tetrahydroxypentane was shown to be ribo, the same as that of the 5-(p-aminophenyl)-1,2,3,4- tetrahydroxypentane moiety found in methanopterin. The complete arylamine side chain of the modified folate thus contains 5-(p-aminophenyl)-1,2,3,4-tetrahydroxypentane attached, via an acid-labile bond, to a currently unidentified substituent. The modified folate present in S. solfataricus thus contains structural features common to both folates and methanopterin.

Radioiodinated anti-hepatocellular carcinoma (HCC) ferritin. Targeting therapy, tumor imaging and anti-antibody response in HCC patients with hepatic arterial infusion

Radioimmunoimaging and radioimmunotherapy with radioiodinated anti-(hepatocellular carcinoma ferritin) antibody (131I- or 125I-FtAb) have been applied in patients with primary liver cancer. A total of 41 patients with surgically unresectable hepatocellular carcinoma (HCC) and receiving hepatic artery ligation and cannulation during exploratory laparotomy were treated with this regimen by intrahepatic arterial infusion. Compared with the control group, a decline of serum alpha-fetoprotein (65.7% versus 42.9%) and shrinkage of tumor (68.3% versus 33.9%) were observed in the treated group, and a higher second-look resection rate (31.7% versus 5.1%) and longer survival (1-year: 61.0% versus 37.3%, 3-year: 25.0% versus 6.9%) resulted. The administration of antibody through a hepatic arterial catheter (n = 16) was compared with intravenous injection (n = 17) in terms of the tumor-imaging sensitivity in 33 patients with liver cancer. The results indicated that hepatic arterial infusion was superior to intravenous injection. The sensitivity 7 days after the administration was 100% in the i.a. group and 76.5% in the i.v. group, the uptake ratio of tumor to liver being 1.74 +/- 0.57 in the former and 1.34 +/- 0.29 in the latter. Furthermore, intrahepatic arterial infusion revealed a lower anti-antibody detection rate than intravenous injection (0/14 versus 4/11).

Liquid chromatographic separation of alkanesulfonate and alkyl sulfate surfactants: effect of ionic strength

The retention of alkanesulfonate and alkyl sulfate surfactants, which was determined on a reversed stationary phase as a function of mobile-phase ionic strength, is consistent with a double-layer type interaction at the stationary-phase surface. Increasing the mobile-phase ionic strength not only increases retention but also improves resolution because peak widths are significantly reduced. The type of cation provided by the ionic strength salt also enhances retention, reduces peak width, and improves resolution. Lithium hydroxide is an ideal electrolyte for the separation of multicomponent mixtures of alkanesulfonate and alkyl sulfate surfactants. When the column effluent is passed through a postcolumn anion micromembrane suppressor, the conductivity due to the electrolyte is minimized and conductivity detection is sensitive, yielding a detection limit of about 0.3 nmol of injected analyte for a 3:1 signal:noise ratio. Multicomponent alkanesulfonate and alkyl sulfate mixtures from C2 to C18 are baseline resolved by using a mobile-phase gradient whereby CH3CN concentration increases and LiOH concentration decreases.

In vitro and in vivo evaluation of microencapsulated porcine islets

To provide a plentiful supply of pancreatic islets for future clinical transplants into diabetic patients, the authors have developed a simple and consistent method of isolation of porcine islets. Both in vitro and in vivo studies demonstrated that the islets were viable and functional. Xenotransplants of 1.5 x 10(3) - 2.5 x 10(3) of microencapsulated porcine islets into diabetic mice resulted in restoration of normoglycemia in 13 of 18 experimental animals for up to 10 months. A xenograft of 50 x 10(3) microencapsulated porcine islets into a spontaneously diabetic monkey normalized hyperglycemia for more than 150 days. This experiment indicated that the transplantation of encapsulated porcine islets has great potential as a clinical treatment in diabetes mellitus.

Neurobiotin, a useful neuroanatomical tracer for in vivo anterograde, retrograde and transneuronal tract-tracing and for in vitro labeling of neurons

The biotin derivative, N-(2-aminoethyl) biotinamide hydrochloride, or Neurobiotin, has been shown recently to be a useful marker for intracellular and anterograde tracing. The properties of Neurobiotin as a tracer were further examined in this study by making pressure injections into different regions of the cerebral cortex or the rostral neostriatum of rats or by incubating striatal cells in culture with the tracer. Results showed extensive anterograde transport of Neurobiotin in cortical axons and terminals within the neostriatum 2-70 h after single or multiple cortical injections of the tracer. Similarly, profuse axonal projections to the medial portion of the globus pallidus were seen after an injection of Neurobiotin into the rostral neostriatum. Transneuronal labeling of medium-size neostriatal neurons was observed following injections of Neurobiotin into the prefrontal cortex. At the ultrastructural level, anterogradely labeled cortical axon terminals and transneuronally labeled neurons were readily identified in the caudate-putamen by the presence of both fine particulate and large punctate reaction products. Retrograde fillings of neurons resembling a Golgi-impregnation were seen in the ventral posterior complex of the thalamus after injections in the sensorimotor cortex. Neurons in the medial globus pallidus were also retrogradely labeled following tracer injections in the rostral caudate-putamen. Finally, Neurobiotin was readily and selectively taken up by striatal neurons in culture, where it extensively labeled somata and neurites. These results show that Neurobiotin is a versatile new tracer, which can be potentially useful for the study of neuronal organization in vivo and in vitro.