Anaerobic dechlorination and degradation of hexachlorocyclohexane isomers by anaerobic and facultative anaerobic bacteria

Screening studies with strict and facultative anaerobic bacteria showed that Clostridium app. and several other representatives of Bacillaceae and Enterobacteriaceae actively degraded -hexachlorocyclohexane (-HCH) under anaerobic conditions. Representatives of Lactobacillaceae and Propronibacterium were inactive. With ³⁶Cl-labelled -HCH a nearly complete dechlorination was shown to occur in 4–6 days by Clostridium butyricum, C. pasteurianum and Citrobacter freundii, while other facultative anaerobic species were less active.Aerobically grown facultative anaerobes also dechlorinated actively -HCH during subsequent anaerobic incubation with glucose, pyruvate or formate as substrates. The -, - and -HCH isomers were also, but more slowly, dechlorinated (>>-HCH). All species active in anaerobic degradation of -HCH formed -tetrachlorocyclohexene (TCH) as the main intermediate metabolite and no -pentachlorocyclohexene (PCH) or other isomers of TCH or PCH have been found. Small amounts of tri- and tetrachlorinated benzenes have been found too. The mechanism of dechlorination is discussed.Non-Common Abbreviations Used -HCH -hexachlorocyclohexane - -TCH -2,3,4,5-tetrachlorocyclohexene - -PCH -1,2,3,4,5-pentachlorocyclohexene - GLC gas liquid chromatography     

High levels of soluble IFN γ receptor α chain in the plasma of rheumatoid arthritis patients

Soluble receptors for hormones and cytokines have beendescribed. They can serve as natural blockers of theirrespective ligands. The natural soluble interferongamma receptor (sIFNR) has been isolated andcharacterized only in urine. Chromatography of human(hu) plasma from rheumatoid arthritis (RA) patientsand controls on immobilized hu IFN orantibodies against IFN R chainpermitted us to isolate the sIFNR. Thereceptor isolated from one control is a protein witha molecular weight between 60-67 kDa depending on thepresence of reducing agents. We detected asignificantly higher level of plasma sIFNR inpatients with rheumatoid arthritis than in apparentlyhealthy subjects.     

Interactions between interferon γ and retinoic acid with transforming growth factor β in the induction of immune recognition molecules

The cell-surface expression of major histocompatibility (MHC) antigens and the adhesion molecule intercellular adhesion molecule 1 (ICAM-1) is essential for target cell recognition by T lymphocytes. The expression of both classes of molecule is induced by various cytokines, notably interferon (IFN). Since transforming growth factor (TGF) has been recently reported to antagonise HLA-DR induction by IFN we have examined, using a number of murine and human cell lines, the effect of TGF on IFN-induced MHC class I and class II and ICAM-1 expression. All of the cell lines tested expressed elevated class I MHC following IFN treatment. Class II MHC induction was seen on most but not all of the cells, the exceptions being among a panel of human colorectal carcinoma cell lines. A striking difference between cells of different origin was noted in the response to TGF. TGF was found to antagonise IFN-induced class I and class II MHC expression on C3H 10T1/2 murine fibroblasts, early-passage BALB/c mouse embryo fibroblasts, a murine oligodendroglioma cell line, and on MRC5 human fibroblasts and two human glioblastoma cell lines. Class II MHC was much more strongly inhibited (sometimes completely) than class I MHC. TGF also inhibited induction of class I MHC expression by IFN. However, TGF did not inhibit class I or class II MHC induction by IFN in any of the nine colorectal carcinoma cell lines, although two of five of the lines tested were growth-inhibited by TGF. On the other hand, human ICAM-1 induction by IFN was not affected by simultaneous treatment with TGF in any of the cell lines. The down-regulation of IFN-induced MHC antigens by TGF is not, therefore, the result of a general antagonism of IFN. Retinoic acid has recently been reported to induce ICAM-1 expression on human tumour cells. We have confirmed this observation on MRC5, and the two human glioblastoma cell lines, however six colorectal carcinoma cell lines tested did not respond. In contrast to IFN-induced ICAM-1 expression, retinoic-acid-induced ICAM-1 expression was inhibited by TGF on two of the three responsive lines.     

Computer-Assisted Analysis of Regulation of the Glycerol-3-Phosphate Metabolism in Genomes of Proteobacteria

Comparative computer-assisted analysis was used to study putative GlpR regulons responsible for metabolism of glycerol and glycerol-3-phosphate in genomes of -, -, and -proteobacteria. New palindromic GlpR-binding signals were identified in -proteobacteria, consensus sequences being TGTTCGATAACGAACA for Enterobacteriaceae, wTTTTCGTATACGAAAAw for Pseudomonadaceae, and AATGCTCGATCGAGCATT for Vibrionaceae. The signals in - and -proteobacteria were also identified: they contained 3–4 direct TTTCGTT repeats separated by 3–4 nucleotide pairs.     

Comparative efficiencies of bispecific F(ab′γ)2 and chimeric mouse/human IgG antibodies in recruiting cellular effectors for cytotoxicity via Fcγ receptors

Summary The three forms of Fc receptor carried by monocytes (FcRI, II) and natural killer (NK) cells (FcRIII) are all capable of mediating cell lysis. Here we compare the use of F(ab)₂ bispecific antibodies, specifically targetting individual FcR, and chimeric IgG mouse/human antibodies which are capable of targetting all FcR, for their ability to mediate target cell destruction. The derivatives are prepared by linking hinge sulphydryl residues via tandem thioether bonds, using a bismaleimide crosslinker: Fab from an anti-FcR mAb linked to Fab from a common anti-target mAb (BsAb), or Fab from the common anti-target mouse antibody linked to human Fc (FabFc or bisFabFc). All the derivatives targetting chick red blood cells gave efficient lysis, although different effector cell donors yielded differences in both the lytic levels achieved and the comparative efficiencies of derivatives. In contrast, significant lysis of the guinea pig lymphoblastic leukaemia, L₂C, regularly resulted only via the anti-FcRIII BsAb and the chimeric derivatives. These results suggest that the chimeric, Fc-containing derivatives mediate tumour cell lysis principally through FcRIII on NK cells. This is in contrast to the situation with the chick red blood cells where the chimeric derivatives appear capable of lysing erythrocytes by utilizing either monocytes or NK cells, because significant (50%) lysis occurred with effector cell populations magnetically depleted through either FcRII or FcRIII. A major difference between these two types of antibody derivative was their ability to function in the presence of high concentrations of normal human Fc. The lysis mediated by BsAb reactive with FcRI or II was unaffected by the presence of human Fc at 2.5 mg/ml (a concentration comparable with that yielded by IgG in plasma) whereas the BsAb recognizing FcRIII and all the Fc-containing derivatives were completely inhibited.This work has been supported by Tenovus, the Cancer Research Campaign, the Leukaemia Research Fund, Italfarmaco, Milano, Italy and the Imperial Cancer Research Fund     

Plasma α- and γ-tocopherol have different pattern during normal human pregnancy

Plasma - and -tocopherol were monitored in pregnant women throughout healthy gestational periods and after delivery and were compared with that of non pregnant women. The mean plasma -tocopherol and -tocopherol concentrations in non pregnant Saudi women (15.2 ± 1.3 and 1.8 ± 0.2 ol/l respectively) were found within normal range. The maternal plasma -tocopherol level steadily increased reaching maximum level (19.1 ± 1.6 mol/l) at late gestation and then gradually decreased after delivery. On the contrary, the optimum level of -tocopherol (2.1 ± 0.2 mol/l) was at mid gestation, followed by a progressive decrease until one month after delivery (1.5 ± 0.1 ol/l). This study shows that the maternal plasma - and -tocopherol have different profiles that may be attributed to their different responses to the changes in maternal lipids during pregnancy.     

T-cell receptor gene rearrangements and expression in normal human large granular lymphocytes (LGL) and their pathological expansions

The lineage to which normal large granular lymphocytes/natural killer (LGL/NK) cells belong is controversial; in fact they share some surface markers and functional activities with monocytes, but also with T lymphocytes. The relationship of LGL to the T cell lineage by analysis with the T cell receptor (T-rec) gene has been investigated. Pure preparations of human LGL and their CD11⁺ CD8^- and CD11^- CD8⁺ subsets had the T gene in its unrearranged germline configuration. Expression of T and T genes was not detectable. The organization of T gene, which is of particular importance because it occurs early in T cell ontogeny, was also found in its germline configuration.A rare type of lymphoproliferative disorder, termed T-LPD, is characterized by expansion of cells very similar to LGL for morphology, phenotype, and functional activity. Of 17 patients with T-LPD studied for T-rec rearrangement, 15 displayed rearrangement of T and T loci and were CD3+ (14/15 had monoclonal rearrangement), while 2 cases were in germline configuration and were CD3–. Similarly to very small subsets of CD3+ LGL recently described, most T-LPD cases are CD3+ and have T-rec genes rearranged. These data suggest that either a subset of LGL or a particular step of differentiation may be related to the T cell lineage; they also demonstrate that, in contrast to previous views, most TLPD are monoclonal, presumably neoplastic, lymphoproliferative disorders.Abbreviations LGL large granular lymphocytes - NK natural killer - T-rec T-cell receptor - TLPD T lymphoproliferative disease     

Synergistic effects of TGIF and interferonγ (IFN-γ) on tumor cell growthTGIF and IFN-γ

Interferon- (IFN-) and tumor growth inhibitory factor (TGIF) were inducedin vitro in the supernatant from mixed culture of human peripheral blood mononuclear cells (PBMC) and OK-432. TGIF activity was determined by growth inhibition of a human gastric adenocarcinoma cell line, MK-1 cells, and IFN- activity was measured by radioimmunoassay. The production of TGIF and IFN- was time-dependent, reaching its maximum around 48 hrs. Although there was no significant correlation between TGIF production and IFN- production, combination of a subthreshold concentration of recombinant IFN- (rIFN-) and TGIF induced significant growth inhibition of MK-1 cells. This fact indicates that the effects of rIFN- and TGIF are synergistic. The antiproliferative effect of these cytokines are highly species-specific, and their synergistic effects were also species-specific. rIFN--sensitive and -resistant clones were successfully established from the original MK-1 cell line; those clones are both sensitive to TGIF. Synergistic antiproliferative effects were found when the rIFN--sensitive clone, but not the resistant clone, was used as a target, suggesting that the synergistic effects require the target cells' sensitivity to IFN-. These results indicate that the synergistic effects of TGIF and IFN- may produce a clinical antitumor action in cancer patients receiving OK-432 administration.     

Gamma-tubulin colocalizes with microtubule arrays and tubulin paracrystals in dividing vegetative cells of higher plants

Summary The distribution of -tubulin throughout cell division is studied in several taxa of higher plants. -Tubulin is present along the whole length of microtubules (Mts) in every cell stage-specific Mt array such as the preprophase band, the preprophase-prophase perinuclear Mts, the kinetochore Mt bundles, the phragmoplast, and the telophase-interphase transition Mt arrays. -Tubulin follows with precision the Mt pattern, being absent from any other, Mt-free, cell site. In cells treated with anti-Mt drugs, -tubulin is present only on degrading or on reappearing Mt arrays, while it is totally absent from cells devoid of Mts. -Tubulin is also present in tubulin paracrystals, which are formed in colchicine-treated cells. These observations support the view that in higher plants -tubulin may not be a microtubule-organizing-center-specific protein, but it may play a certain structural and/or functional role being related to - and -tubulin.Abbreviations Mt microtubule - MTOC microtubule-organizing center - PPB preprophase band     

Labdane diterpene derivatives from Holwaya mucida

Clumps of white crystals present in 40-day-old malt agar cultures of Holwaya mucida were isolated as long white needles by crystallization from ethanol following short extraction with chloroform. The levorotary compound ([] ₂₈₉ ²¹ =-193.8°) was recognized as a -lactone (C₁₇H₂₀O₅) by infrared and mass spectrometry. It was identified as 7-methoxy-3a, 10b-dimethyl-1, 2, 3, 3a, 5a, 7, 10b, 10c-octahydro-4H, 9H-furo[2, 3, 4 : 4, 5]naphtho[2, 1-c]pyran-4, 9-dione, a labdane-derived compound known as antibiotic LL-Z1271. Preparative thin-layer chromatography of the mother liquor afforded 2 minor metabolites. One was identified as LL-Z1271, the demethylated analogue of LL-Z1271. The other one named LL-Z1271, was recognized as a compound related to and : its structure could not be fully elucidated. H. mucida (anamorph: Crinula calciiformis) has no taxonomic relationship with two other LL-Z1271 producing species viz. Acrostalagmus sp. (= Acremonium cf. atrogriseum) and Oidiodendron truncatum.