Increased soluble Fas ligand concentration in tuberculous pleural effusion

BACKGROUND AND PURPOSE

Tuberculous (TB) pleurisy results from a delayed hypersensitivity reaction involving macrophages, T-cells, and many cytokines (including tumor necrosis factor, interferon-gamma, and interleukin 1 and 2). Infection by Mycobacterium tuberculosis induces apoptosis in gamma/delta T-cells and macrophages. Fas ligand (FasL) is a type II membrane protein that plays an important role in the regulation of apoptosis and has an intimate relation with these cells and cytokines. A soluble form of FasL (sFasL) exists in a variety of human body fluids, including serum, pleural effusion, cerebral spinal fluid, and ocular fluid. Therefore, we hypothesized that Fas activity is elevated in TB pleurisy. This study investigated the concentration of sFasL in TB pleural effusions and compared it with expression of sFasL in various other pleural effusions.

METHODS

Using an enzyme-linked immunosorbent assay, we investigated the sFasL concentrations of 80 pleural effusions from patients with various diagnoses.

RESULTS

The median sFasL concentration in the TB pleural effusion group was 104.91 pg/mL (n = 32). This was significantly higher than values in the transudate group (median value, 20.02 pg/mL, n = 9, p < 0.001) and patients with malignant effusion associated with adenocarcinoma of the lung (median value, 23.29 pg/mL, n = 14, p < 0.001). Lymphoproliferative disease could not be distinguished from TB based on sFasL concentrations in pleural effusion.

CONCLUSIONS

The sFasL concentration in TB pleural effusions is significantly higher than that in adenocarcinomatous pleural effusions, which are the most common malignant pleural effusions. This difference may serve as a diagnostic tool to differentiate these two most commonly encountered unexplained pleural effusions. Determination of the cellular source and the actual role of the abundant sFasL in TB pleurisy will require further investigation.

Structure of tetragonal crystals of human erythrocyte catalase

The structure of catalase from human erythrocytes (HEC) was determined in tetragonal crystals of space group I4(1) by molecular-replacement methods, using the orthorhombic crystal structure as a search model. It was then refined in a unit cell of dimensions a = b = 203.6 and c = 144.6 A, yielding R and R(free) of 0.196 and 0.244, respectively, for all data at 2.4 A resolution. A major difference of the HEC structure in the tetragonal crystal compared with the orthorhombic structure was the omission of a 20-residue N-terminal segment corresponding to the first exon of the human catalase gene. The overall structures were otherwise identical in both crystal forms. The NADPH-binding sites were empty in all four subunits and bound water molecules were observed at the active sites. The structure of the C-terminal segment, which corresponds to the last exon, remained undetermined. The tetragonal crystals showed a pseudo-4(1)22 symmetry in molecular packing. Two similar types of lattice contact interfaces between the HEC tetramers were observed; they were related by the pseudo-dyad axes.

A new triterpenoid from Azadirachta indica

A new triterpenoid, 1 alpha,7 alpha-diacetoxyapotirucall-14-en e-3 alpha, 21,22,24,25-pentaol (1), and the two known compounds odoratone (2) and 2 beta,3 beta,4 beta-trihydroxypregnan-16-o ne (3) were isolated from a methanolic extract of the seed kernels of Azadirachta indica. Their structures were elucidated on the basis of spectral methods.

Synthesis and cytotoxic effect of 1,3-dihydroxy-9,10-anthraquinone derivatives

1,3-Dihydroxy-9,10-anthraquinone (4) was reacted with epichlorohydrin or 1,omega-dibromo-alkane to yield 1-hydroxy-3-(2,3-epoxypropoxy)-9,10-anthraquinone (5) and 1-hydroxy-3-(3-chloro-2-hydroxypropoxy)-9,10-anthraquinone (6) or 1-hydroxy-3-(omega-bromoalkoxy)-9,10-anthraquinone. Ring-opening of the epoxide (5) or 1-hydroxy-3-(omega-bromoalkoxy)-9,10-anthraquinones with appropriate amines, afforded various 1-hydroxy-3-(3-alkylamino-2-hydroxypropoxy)-9,10-anthraquinones. The synthetic compounds were tested in vitro inhibition of human T-24, Hep 3B, Hep G2, SiHa, HT-3, PLC/PRF/5 and 212 cells. Almost all compounds showed significant inhibitory activity against several different cancer cell lines. Structure-activity analysis indicated epoxidation of the hydroxyanthraquinone increased cytotoxicity against tumour cells, but ring-opening of the epoxide group with amine did not enhance the cytotoxic activity. The phosphatidylserine (PS) externalization and DNA fragmentation in SiHa cells were significantly observed after 48 h incubation with selected compound 19. The results show that 19 cause cell death by apoptosis.

Components of Cipadessa baccifera

Four compounds were isolated from dry seeds of Cipadessa baccifera (Roth) Miq. along with the known 2beta,3beta,4beta-trihydroxypregnan-16-one, febrifugin, and khaysin T. Their structures were elucidated on the basis of spectral analysis to be cipadesin, 17alpha,20R-dihydroxypregnan-3,16-dione, 1,4-epoxy-16-hydroxyheneicos-1,3,12,14,18-pentaene and 1,4-epoxy-16-hydroxyheneicos-1,3,12,14-tetraene.

Defining the bilin lyase domain: lessons from the extended phytochrome superfamily

Through pattern searches of genomic databases, new members of the growing family of phytochrome-related genes were identified and used to construct a 130-180 amino acid motif that delimits the bilin lyase domain, a subdomain of the extended phytochrome family that is sufficient for covalent attachment of linear tetrapyrroles (bilins). To test this hypothesis, portions of locus sll0821, a novel phytochrome-related gene from Synechocystis sp. PCC6803 that encodes a large protein with two potential bilin binding sites, were amplified, and the recombinant apoproteins were tested for bilin binding and phytochrome photoactivity. Our experiments indicated that both sites of this protein, termed Cph2 for cyanobacterial phytochrome 2, possessed bilin lyase activity, revealing two distinct classes of bilin lyase domains--those whose bilin adducts are red, far-red reversible and a second class whose bilin adducts are nonphotochromic. Spectroscopic analysis of photochromic phycocyanobilin and fluorescent phycoerythrobilin adducts of a 24-kDa fragment of Cph2 definitively established that the motif identified by pattern searches represents a bona fide bilin lyase domain. Site-directed mutagenesis of highly conserved charged residues within bilin lyase domains of nearly all members of the extended phytochrome superfamily has identified a glutamate residue critical for bilin binding.

Developmental changes in physiological properties in the rat's dorsal nucleus of the lateral lemniscus

To better understand the development of the dorsal nucleus of the lateral lemniscus (DNLL), intrinsic membrane properties and synaptic responses of DNLL neurons in brain slice preparations were examined. Intracellular recordings were taken from DNLL neurons of rat pups at postnatal days 4-8 (early group), 10-12 (intermediate group) and 16-18 (late group). In response to positive current injection, neurons in the early group displayed firing with lower frequency and a longer action potential duration in comparison to the intermediate and late groups. The action potential amplitude of DNLL neurons increased during development. Postsynaptic potentials (PSPs), with excitatory predominance, were elicited by electrical stimulation of the lateral lemniscus and commissure of Probst throughout the three age groups. Neurons showed a longer latency and rise time of the PSPs in the early group in comparison with those in the intermediate and late groups. These results suggest that the early DNLL neurons display physiological characteristics associated with immature neurons, while the other two groups tend to illustrate mature-like neuronal properties. Furthermore, it seems that the neurons at day 10-12 are in a transitional period of development, which coincides with the onset of hearing.

Limonoids and phytol derivatives from Cedrela sinensis

Two new compounds, cedrellin (1) and 2,6,10,15-phytatetraene-14-ol (2), together with five known compounds, 7 alpha-obacunyl acetate, 6-acetoxyobacunol acetate, 7 alpha-acetoxydihydronomilin, 2,6,10-phytatriene-1,14,15-triol and phytol were isolated from leaves of Cedrela sinensis. Their structures were elucidated on the basis of combined one- and two-dimensional spectral techniques.

Long-term potentiation in the inferior colliculus studied in rat brain slice

The purpose of this study is to determine whether long-term potentiation (LTP) can be induced in the central nucleus of the inferior colliculus (ICC) by electrical stimulation of the lateral lemniscus. If LTP can be induced, is it mediated by N-methyl-D-aspartate (NMDA) and/or other receptors? Brain slices of the ICC were obtained from 14-35 day old Wistar rats. The field potentials were recorded from the ICC after GABAergic and glycinergic inhibition was suppressed. Following tetanic stimulation (50 Hz, 20 s), the amplitude of the response was increased to about 146% of control response for at least 30 min. LTP was observed in about 78% of the cases tested. Induction of LTP in the ICC required activation of both NMDA and gamma-aminobutyric acid (GABA)(B) receptors. GABAergic inhibitory postsynaptic potentials (IPSPs) were blocked by the GABA(A) receptor antagonist, but not by the GABA(B) receptor antagonist. The IPSPs were decreased by the GABA(B) receptor agonist, baclofen. The intrinsic postsynaptic membrane properties were not affected by baclofen. These results suggest that GABAergic inhibition in the ICC is mediated only by GABA(A) receptors, but that it is modulated by presynaptic GABA(B) receptors. The GABA(B) receptors in the ICC may suppress GABAergic inhibition and promote induction of LTP.

Tirucallane triterpenoids from Dysoxylum hainanense

Four tirucallane derivatives, 3beta,22S-dihydroxy-tirucalla-7,24-dien-23-one, 22,23-epoxy-tirucalla-7-ene-3beta,24,25-triol, 3beta,25-dihydroxy-tirucalla-7,23-diene, 23,26-dihydroxy-tirucalla-7,24-dien-3-one, together with two known triterpenoids, 24,25-epoxy-3beta,23-dihydroxy-7-tirucallene, tirucalla-7,24-diene-3beta,23-diol, were isolated from Dysoxylum hainanense. Their structures were elucidated on the basis of spectroscopic evidence.

Tetranortriterpenoids from Walsura yunnanensis

Five new tetranortriterpenoids-walsurin (1), isowalsuranolide (2), walsuranolide (3), 11beta-acetoxywalsuranolide (4), and 20, 22-dihydro-22,23-epoxywalsuranolide (5)-and three new natural tetranortriterpenoids-11beta-hydroxydihydrocedrelone (6), 11beta-acetoxydihydrocedrelone (7), and 11beta-hydroxycedrelone (8)-together with a known tetranortriterpenoid, cedrelone (9), were isolated from the bark of Walsura yunnanensis. The structures of 1-8 were determined on the basis of spectral evidence.

Alkaloid-fullerene systems through photocycloaddition reactions

The photocycloaddition of tertiary amines to ¿60fullerene (C(60)) is an interesting and useful reaction. We wished to extend the applications of this type of reaction through an investigation of the photoaddition of alkaloids to C(60) for the purpose of synthesizing novel and complex photoadducts that are difficult to obtain by usual methods. Irradiation of tazettine (2) or gramine (3) with C(60) in toluene leads to formation of one monoadduct (6 or 7), whereas scandine (1a) or 10-hydroxyscandine (1b) reacts with C(60) photochemically to give two products, the expected ¿6,6 monoadduct (5a, 5b) and a new type of monoadduct with a bis-¿6, 6 closed structure (4a, 4b). These new structures were characterized by UV-vis, FT-IR, (1)H NMR, (13)C NMR, (1)H-(1)H COSY, ROESY, HMQC (heteronuclear multiple-quantum coherence), and HMBC (heteronuclear multiple-bond connectivity) spectroscopy. The techniques of time-of-flight secondary ion MS (TOF-SIMS) and field desorption MS (FD-MS) were used for the mass determination. (3)He NMR analysis of the product mixture from photoaddition of 1a to C(60) containing a (3)He atom ((3)He@C(60)) led to two peaks at -9.091 and -11.090 ppm relative to gaseous (3)He, consistent with formation of a ¿6, 6-closed monoadduct and a bis-¿6,6 closed adduct. Presumably, the bis-¿6, 6 closed adducts are formed by an intramolecular ¿2 + 2 cycloaddition of the vinyl group to the adjacent 6,6-ring junction of C(60) after the initial photocycloaddition.

[Separation and determination of tyramine by reversed-phase high performance liquid chromatography]

The method for separation and determination of tyramine by reversed-phase high performance liquid chromatography has been established. The effects of mobile phase on mechanism of separation based on the ion interaction are discussed. Using C8 alkyl bonded phase and 40% methanol-water solution containing Trisperchlorate as pH buffer (adjusted pH to 7.9) and ion interaction reagent and applying p-toluene sulfonamide as internal standard substance, the tyramine obtained from decarboxylation of p-tyrosine was determined. The RSD of determination was 0.66%(n = 11). The recoveries of sample were between 99.33% and 100.38%.

[Functional and structural study of the prokaryotic enhancer-like element VV16 from vaccinia virus genome]

An enhancer-like element VV16 from Vaccinia virus genome DNA was obtained by using the plasmid with CAT reporter gene. Sequence analysis showed the element of 112 bp is a part of the DNA-dependent RNA polymerase, polyA polymerase and DNA polymerase (RPO30 gene). It contains 4 AT-rich regions. Detection of beta-galactosidase activity showed that VV16 in the positive direction can increase the activity 9.0 times and VV16 in the negative direction can increase 4.1 times. The RNA dot blotting confirmed the enhancing activity of the element are on the transcription level. DNA deletion experiment indicated the sequences of 10 bp at the 5' end and 12 bp at the 3' end in the element are important to its function and the sequence from nt76 to nt82 is essential to its activity.

Purification and properties of ornithine racemase from Clostridium sticklandii

Ornithine racemase has been purified to homogeneity from Clostridium sticklandii, as shown by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. This is the first racemase known to be highly specific to ornithine. This PLP-dependent enzyme has an M(r) of 92, 000, with a K(m) for L-ornithine of 0.77 +/- 0.05 mM and a k(cat) of 980 +/- 20 s(-1).

Two novel secoergosterols from the fungus Tylopilus plumbeoviolaceus

Two novel secoergosterols, 3beta-hydroxy-8alpha,9alpha-oxido-8, 9-secoergosta-7,9(11),22-triene (tylopiol A) (1) and 3beta-hydroxy-8alpha,9alpha-oxido-8,9-secoergosta-7,22 -dien-12-one (tylopiol B) (2), were isolated from the fresh fruit bodies of Tylopilus plumbeoviolaceus, along with three known compounds, ergosta-7,22-dien-3beta-ol, uridine, and allitol. Their structures were elucidated by NMR techniques, including (1)H NMR, (13)C NMR, HMQC, HMBC, and MS. The structure and stereochemistry of compound 1 were demonstrated by X-ray crystallography.

Structure of human erythrocyte catalase

Catalase (E.C. 1.11.1.6) was purified from human erythrocytes and crystallized in three different forms: orthorhombic, hexagonal and tetragonal. The structure of the orthorhombic crystal form of human erythrocyte catalase (HEC), with space group P2(1)2(1)2(1) and unit-cell parameters a = 84.9, b = 141.7, c = 232.5 A, was determined and refined with 2.75 A resolution data. Non-crystallographic symmetry restraints were employed and the resulting R value and R(free) were 0.206 and 0.272, respectively. The overall structure and arrangement of HEC molecules in the orthorhombic unit cell were very similar to those of bovine liver catalase (BLC). However, no NADPH was observed in the HEC crystal and a water was bound to the active-site residue His75. Conserved lattice interactions suggested a common growth mechanism for the orthorhombic crystals of HEC and BLC.

[Functional and structural analysis of a prokaryotic enhancer-like element in Escherichia coli MC1061 strain]

Cat and lacZ genes were used as reporter gene and three prokaryotic enhancer-like element (MC2, MC8 and MC9) were identified in the genomic DNA of MC1061 strain. All three fragments can improve the expression of lacZ gene by 2-5 times with the orientation independence. The results of in vivo transcription and Dot blot hybridization assays suggested that MC8 regulated the expression of lacZ at transcription level. Stepwise deletion expreriments showed the functional domain of MC8 located at 450-950 bp, and in regions 450-600 bp and 840-950 bp contain at least one functional loci. Sequence data indicated three are 3 A + T rich sections in MC8, 2 of them are in the functional loci.

The commissure of probst as a source of GABAergic inhibition

Whole-cell patch-clamp recordings were made from neurons in the rat's dorsal nucleus of the lateral lemniscus (DNLL) in a brain slice preparation. Planes of section were chosen to preserve the integrity of fibers in the commissure of Probst (CP) and postsynaptic responses were evoked by electrical stimulation along its length. Results showed that the crossed projection to the DNLL through the CP is mainly, if not exclusively, inhibitory in the rat. Inhibitory postsynaptic responses (IPSPs) evoked by stimulation of the CP were blocked by the gamma-aminobutyric acid (GABA)(A) receptor antagonist bicuculline, but were unaffected by the glycine receptor antagonist strychnine, supporting the conclusion that the crossed inhibitory projection to DNLL from the contralateral DNLL is GABAergic. Stimulation of the CP close to the DNLL frequently evoked excitatory postsynaptic responses as well as IPSPs, but stimulation near the midline evoked IPSPs only. Thus, the excitatory responses probably originated from a pathway other than the projection to the DNLL from the contralateral DNLL through the CP.

Physiological properties of neurons in the ventral nucleus of the lateral lemniscus of the rat: intrinsic membrane properties and synaptic responses

The physiological properties including current-voltage relationships, firing patterns, and synaptic responses of the neurons in the ventral nucleus of the lateral lemniscus (VNLL) were studied in brain slices taken through the young rat's (17-37 days old) auditory brain stem. Intracellular recordings were made from VNLL neurons, and synaptic potentials were elicited by electrical stimulation of the lateral lemniscus ventral to the VNLL. Current-voltage relations and firing patterns were tested by recording the electrical potentials produced by intracellular injection of positive and negative currents. There were two types of VNLL neurons (type I and II) that exhibited different current-voltage relationships. In response to negative current, both type I and II neurons produced a graded hyperpolarization. Type I neurons responded to positive current with a graded depolarization and multiple action potentials the number of which was related to the strength of the current injected. The current-voltage relations of type I neurons were nearly linear. Type II neurons responded to positive current with a limited depolarization and only one or a few action potentials. The current-voltage relations of type II neurons were nonlinear near the resting potential. The membrane properties of the type II VNLL neurons may play an important role for processing information about time of onset of a sound. Type I neurons showed three different firing patterns, i.e., regular, onset-pause and adaptation, in response to small positive current. The onset-pause and adaptation patterns could become sustained when a large current was injected. The regular, onset-pause, and adaptation patterns in type I neurons and the onset pattern in type II neurons resemble "chopper," "pauser, " "primary-like," and "on" responses, respectively, as defined in in vivo VNLL studies. The results suggest that different responses to acoustic stimulation could be attributed to intrinsic membrane properties of VNLL neurons. Many VNLL neurons responded to stimulation of the lateral lemniscus with excitatory or inhibitory responses or both. Excitatory and inhibitory responses showed interaction, and the output of the synaptic integration depended on the relative strength of excitatory and inhibitory responses. Neurons with an onset-pause firing pattern were more likely to receive mixed excitatory and inhibitory inputs from the lower auditory brain stem.

Lipase-catalyzed acetylation of N-acetylneuraminic acid derivative

A facile preparation of triacetylated derivative of 2-phenylthioglycoside of N-acetylneuraminic acid (4) was achieved by treatment with lipase PS in vinyl acetate. The major product 4 has a free hydroxyl group at C-7. Results of time-course HPLC analysis indicate that the reactivity of the hydroxyl groups under this condition is in the following order; C-9 > C-4 > C-8 > C-7.

Controlled acid hydrolysis of colominic acid under microwave irradiation

The hydrolysis of colominic acid under microwave irradiation was studied and compared with traditional heating methods. The microwave irradiation has several advantages over the heating method in the hydrolysis of colominic acid: (a) products with higher degrees of polymerization are obtained, (b) less lactone byproducts are observed, and (c) the hydrolytic rate is much faster. These advantages are probably due to the microwave effect. Oligosialic acids as the products of the acid hydrolysis of polysialic acid with conventional heating methods were fully lactonized, especially under the conditions of higher temperature and stronger acid.

Purification, characterization and molecular cloning of trichoanguin, a novel type I ribosome-inactivating protein from the seeds of Trichosanthes anguina

The seeds of the plant Trichosanthes anguina contain a type I ribosome-inactivating protein (RIP), designated trichoanguin, which was purified to apparent homogeneity by the combined use of ion-exchange chromatographies, i.e. first with DE-52 cellulose and then with CM-52 cellulose. The protein was found to be a glycoprotein with a molecular mass of 35 kDa and a pI of 9.1. It strongly inhibits the protein synthesis of rabbit reticulocyte lysate, with an IC50 of 0.08 nM, but only weakly that of HeLa cells, with an IC50 of 6 microM. Trichoanguin cleaves at the A4324 site of rat 28 S rRNA by its N-glycosidase activity. The cDNA of trichoanguin consists of 1039 nt and encodes an open reading frame coding for a polypeptide of 294 amino acid residues. The first 19 residues of this polypeptide encode a signal peptide sequence and the last 30 residues comprise an extension at its C-terminus. There are four potential glycosylation sites, located at Asn-51, Asn-65, Asn-201 and Asn-226. A comparison of the amino acid sequence of trichoanguin with those of RIPs such as trichosanthin, alpha-momorcharin, ricin A-chain and abrin A-chain reveals 55%, 48%, 36% and 34% identity respectively. Molecular homology modelling of trichoanguin indicates that its tertiary structure closely resembles those of trichosanthin and alpha-momorcharin. The large structural similarities might account for their common biological effects such as an abortifacient, an anti-tumour agent and anti-HIV-1 activities. Trichoanguin contains two cysteine residues, Cys-32 and Cys-155, with the former being likely to be located on the protein surface, which is directly amenable for conjugation with antibodies to form immunoconjugates. It is therefore conceivable that trichoanguin might be a better type I RIP than any other so far examined for the preparation of immunotoxins, with a great potential for application as an effective chemotherapeutic agent for the treatment of cancer.