Recovery of cellulase from Blue mussel homogenate with expended bed metal affinity chromatography

We studied the purification of cellulase from Blue mussel homogenate with STREAMLINE chelating adsorbent in an expended bed chromatography. The cellulase was purified 19.5 times without removing the cell debris and a recovery of 82% was obtained.

Substituted isoquinolines and quinazolines as potential antiinflammatory agents. Synthesis and biological evaluation of inhibitors of tumor necrosis factor alpha

A series of isoquinolin-1-ones and quinazolin-4-ones and related derivatives were prepared and evaluated for their ability to inhibit tumor necrosis factor alpha (TNFalpha) production in human peripheral blood monocytes stimulated with bacterial lipopolysaccharide (LPS). In an effort to optimize the TNFalpha inhibitory activity, a homologous series of N-alkanoic acid esters was prepared. Several electrophilic and nucleophilic substitutions were also carried out. Alkanoic acid esters of four carbons were found to be optimum for activity in both the isoquinoline and quinazoline series. Ring substituents such as fluoro, bromo, nitro, acetyl, and aminomethyl on the isoquinoline ring resulted in a significant loss of activity. Likewise, similar groups on the quinazoline ring also reduced inhibitory activity. However, the 6- and 7-aminoquinazoline derivatives, 75 and 76, were potent inhibitors, with IC(50) values in the TNFalpha in vitro assay of approximately 5 microM for each. An in vivo mouse model of pulmonary inflammation was then used to evaluate promising candidate compounds identified in the primary in vitro assay. Compound 75 was selected for further study in this inhalation model, and was found to reduce the level of TNFalpha in brochoalveolar lavage fluid of LPS-treated mice by about 50% that of control mice. Thus, compounds such as 75, which can effectively inhibit proinflammatory cytokines such as TNFalpha in clinically relevant animal models of inflammation and fibrosis, may have potential as new antiinflammatory agents. Finally, a quinazoline derivative suitable to serve as a photoaffinity radiolabeled compound was prepared to help identify the putative cellular target(s) for these TNFalpha inhibitors.

[Effects of anticoagulants, temperature and sex on the spontaneous activation of neutrophils in vitro]

From the view of cellular morphology and enzymic histochemistry, we used the pseudopod method and NBT test to measure spontaneous activation of neutrophils in vitro. The effects of anticoagulant, temperature, and sex on the percentage of spontaneously activated neutrophils were studied. The results suggest that heparin is a better anticoagulant than EDTA because EDTA because EDTA inhibits neutrophil activation; that a higher percentage of activated neutrophils can be obtained when incubated at 37 degrees C, compared with the percentage at 25 degrees C, and at 37 degrees C the highest percentage appears an hour earlier; and that females show a higher percentage of spontaneously activated neutrophils than males, and females' highest percentage appears an hour earlier than males'. These are of referential value for further studies.

[A study on ovariectomized goat osteoblast culture in vitro]

Osteoblasts were isolated from the frontal parietal bone of ovariectomized goat and were confirmed by testing for multiple biological features. The results showed that the goat osteoblasts cultured had the typical morphological feature of osteoblasts, the activity of alkaline phosphatase, and the ability of calcification in vitro. Also, the results proved that these goat osteoblasts in vitro had the same function and features as those in vivo. The experimental techniques in this study have provided a useful system for researches in bone metabolism.

Mitotic recombination produces the majority of recessive fibroblast variants in heterozygous mice

Mice heterozygous at Aprt (adenine phosphoribosyltransferase) were used as a model to study in vivo loss of heterozygosity (LOH) in normal fibroblasts. Somatic cell variants that exhibited functional loss of the wild-type Aprt in vivo were recovered as APRT-deficient cell colonies after culturing in selection medium containing 2, 6-diaminopurine (DAP), an adenine analog that is toxic only to cells with APRT enzyme activity. DAP-resistant (DAP(r)) fibroblast variants were recovered at a median frequency of 12 x 10(-5) from individual ears from progeny of crosses between mouse strains 129/Sv and C3H/HeJ. The frequency of DAP(r) variants varied greatly among individual ears, suggesting that they preexisted in vivo and arose at various times during development. Polymorphic molecular markers and a cytological marker on the centromere of chromosome 8 made it possible to discriminate between each of six possible mechanistic pathways of LOH. The majority (about 80%) of the DAP(r) variants were a consequence of mitotic recombination. The prevalence of mitotic recombination in regions proximal to Aprt did not correlate with meiotic map distances. In particular, there was a higher than expected frequency of crossovers within the interval 59 cM to 67 cM. The high spontaneous frequency of Aprt LOH, mediated primarily by mitotic recombination, is fully consistent with our previous results with human peripheral T cells from individuals known to be heterozygous at APRT. Thus, this Aprt heterozygote mouse is a valid model for studying somatic mutagenesis and mitotic recombination in vivo.

[One-time operation in infant cleft lip and palate plus alveolar process]

OBJECTIVE

To improve safety and viability of one-time operation in the therapy of cleft lip and palate and cleft alveolar process.

METHODS

Under the air-vein anesthesia, one-time operations were performed in 42 patients with complete cleft lip and palate plus cleft alveolar process. After rehabilitation in ICU, all patients were put into wards, and left hospital 4-7 days after operation.

RESULTS

The situation during anesthesia and operation was good. There were no statistically significant changes in blood pressure, oxygen saturation of blood, heart rate and cardiac rhythm before, during and after operation. No anesthetic accident and no complication happened. The loss of blood was about 42.7 +/- 6.5 ml and the duration of operation was about 139.2 +/- 18.6 minutes. The rehabilitation was successful after operations. First intention took place in almost all patients' incisions, and palatal fistulas appeared in only 2 cases.

CONCLUSION

Under the control of provisioned pediatric anesthesia and rehabilitation, one-time complete cleft lip and palate plus cleft alveolar process closure is safe and viable.

Staphylococcus aureus cap5P encodes a UDP-N-acetylglucosamine 2-epimerase with functional redundancy

The serotype 5 capsule gene cluster of Staphylococcus aureus comprises 16 genes (cap5A through cap5P), but little is known about how the putative gene products function in capsule biosynthesis. We propose that the N-acetylmannosaminuronic acid (ManNAcA) component of the S. aureus serotype 5 capsular polysaccharide (CP5) is synthesized from a UDP-N-acetylglucosamine (UDP-GlcNAc) precursor that is epimerized to UDP-N-acetylmannosamine (UDP-ManNAc) and then oxidized to UDP-ManNAcA. We report the purification and biochemical characterization of a recombinant UDP-GlcNAc 2-epimerase encoded by S. aureus cap5P. Purified Cap5P converted approximately 10% of UDP-GlcNAc to UDP-ManNAc as detected by gas chromatography-mass spectrometry. The epimerization of UDP-GlcNAc to UDP-ManNAc occurred over a wide pH range and was unaffected by divalent cations. Surprisingly, CP5 expression in S. aureus was unaffected by insertional inactivation of cap5P. Sequence homology searches of the public S. aureus genomic databases revealed the presence of another putative UDP-GlcNAc 2-epimerase on the S. aureus chromosome that showed 61% identity to Cap5P. Redundancy of UDP-GlcNAc 2-epimerase function in S. aureus was demonstrated by cloning the cap5P homologue from strain Newman and complementing an Escherichia coli rffE mutant defective in UDP-GlcNAc 2-epimerase activity. Our results confirm the putative function of the S. aureus cap5P gene product and demonstrate the presence of a second gene on the staphylococcal chromosome with a similar function.

Potent and selective human beta(3)-adrenergic receptor antagonists

Although the functional presence of beta(3)-adrenergic receptors (beta(3)-AR) in rodents is well established, its significance in human adipose tissue has been controversial. One of the issues confounding the experimental data has been the lack of potent and selective human beta(3)-AR ligands analogous to the rodent-specific agonist BRL37344. Recently, we described a new class of aryloxypropanolamine beta(3)-AR agonists that potently and selectively activate lipolysis in rhesus isolated adipocytes and stimulate the metabolic rate in rhesus monkeys in vivo. In this article, we describe novel and selective beta(3)-AR antagonists with high affinity for the human receptor. L-748,328 and L-748,337 bind the human cloned beta(3)-AR expressed in Chinese hamster ovary (CHO) cells with an affinity of 3.7 +/- 1.4 and 4.0 +/- 0.4 nM, respectively. They display an affinity of 467 +/- 89 and 390 +/- 154 nM for the human beta(1)-AR. Their selectivity for human beta(3)-AR versus beta(2)-AR is greater than 20-fold (99 +/- 43 nM) and 45-fold (204 +/- 75 nM), respectively. These compounds are competitive antagonists capable of inhibiting the functional activation of agonists in a dose-dependent manner in cells expressing human cloned beta(3)-AR. Moreover, both L-748,328 and L-748,337 inhibit the lipolytic response elicited by the beta(3)-AR agonist L-742,791 in isolated nonhuman primate adipocytes. The aryloxypropanolamine benzenesulfonamide ligands illustrated here and elsewhere demonstrate high-affinity human beta(3)-AR binding. In addition, we describe specific 3'-phenoxy substitutions that transform these compounds from potent agonists into selective antagonists.

Potent, elective human beta3 adrenergic receptor agonists containing a substituted indoline-5-sulfonamide pharmacophore

A series of compounds possessing an N-substituted indoline-5-sulfonamide pharmacophore was prepared and evaluated for their human beta3 adrenergic receptor agonist activity. The SAR of a wide range of urea and heterocyclic substituents is discussed. 4-Octyl thiazole compound 8c was the most potent and selective compound in the series, with 2800-fold selectivity over beta1 binding and 1400-fold selectivity over beta2 binding.

cDNA representational difference analysis of differentially expressed cDNA sequences in human nasopharyngeal carcinoma

OBJECTIVE

To search differentially expressed sequences correlated with pathogenesis of human nasopharyngeal carcinoma (NPC), including the candidates of tumor suppressor genes.

METHODS

Representational difference analysis (RDA) was performed to isolate differentially expressed sequences between cDNA from normal human primary cultures of nasopharyngeal epithelial cells and cDNA from NPC cell line HNE1. The source of differentially expressed products were proved by Southern blot, Northern blot and in situ hybridization. The fragments were cloned with pGEM-T easy kit and sequenced by the chain termination reaction.

RESULTS

Four differentially expressed cDNA fragments were isolated in the fourth subtractive hybridization using cDNA from normal human nasopharyngeal epithelial cells as tester amplicon and cDNA from NPC cell line HNE1 as driver amplicon by cDNA RDA. These differential cDNA fragments revealed that they really came from the tester amplicon and were not expressed or down-regulated in the NPC HNE1 cells. Some of the genes were expressed only in human nasopharyngeal epithelial cells but deleted or down-regulated in the biopsies of NPC. Of these obtained clones, some were the sequences of the human known genes including house-keeping genes, the others represented novel gene sequences.

CONCLUSION

The differentially expressed products including the candidates of tumor-suppressor genes may be associated with the initiation of the NPC.

L-770,644: a potent and selective human beta3 adrenergic receptor agonist with improved oral bioavailability

L-770,644 (9c) is a potent and selective agonist of the human beta3 adrenergic receptor (EC50 = 13 nM). It shows good oral bioavailability in both dogs and rats (%F = 27), and is a full agonist for glycerolemia in the rhesus monkey (ED50 = 0.21 mg/kg). Based on its desirable in vitro and in vivo properties, L-770,644 was chosen for further preclinical evaluation.

[Using the method of two-color fluorescence in situ hybridization to detect aneuploidy of human sperms]

OBJECTIVE

To develop the method of two-color fluorescence in situ hybridization (FISH) assay and use it for detecting the aneuploidy frequency of human sperm chromosome.

METHODS

Sperm sample was washed three times and the slides were prepared. The sperm heads were decondensed with dithiothreitol (DTT) and lithium diiodosalicylate (LIS). Then, the sperm nuclei were hybridized with biotin labeled alpha satellite X chromosome DNA probe (DXZ1) and digoxigenin labeled alpha satellite Y chromosome DNA probe (DYZ3). The hybridization signals were detected with CY3-Streptavidin, goat antistrepavidin for biotin labeled probe and with mouse antidigoxigenin, rabbit antimouse-FITC for digoxigenin labeled probe.

RESULTS

Under the Nikon fluorescence microscope, the hybridization signals in the sperm heads were clearly visible. The sperm with one red hybridization signal was X chromosome sperm (X sperm), and the sperm with one green hybridization signal in the sperm head was Y chromosome sperm (Y sperm). In the case of two hybridization signals in one sperm head, the sperm should be a numerical abnormal one. By using two color FISH with one euchromosome probe and one sex chromosome probe, the sperm with same color of two hybridization signals in one sperm head could be identified as aneuploidy sperm or diploid sperm.

CONCLUSION

The two color FISH assay may be used to detect the aneuploidy frequency of human sperms that were exposed to mutagents and environmental potential aneuoploidogenic agents.

A well-collimated quasi-continuous atom laser

Extraction of sodium atoms from a trapped Bose-Einstein condensate (BEC) by a coherent, stimulated Raman process is demonstrated. Optical Raman pulses drive transitions between trapped and untrapped magnetic sublevels, giving the output-coupled BEC fraction a well-defined momentum. The pulsed output coupling can be run at such a rate that the extracted atomic wave packets strongly overlap, forming a highly directional, quasi-continuous matter wave.

Human beta3 adrenergic receptor agonists containing cyclic ureidobenzenesulfonamides

Human beta3 adrenergic receptor agonists containing 5-membered ring ureas were shown to be potent partial agonists with excellent selectivity over beta1 and beta2 binding. L-760,087 (4a) and L-764,646 (5a) (beta3 EC50 = 18 and 14 nM, respectively) stimulate lipolysis in rhesus monkeys (ED50 = 0.2 and 0.1 mg/kg, respectively) with minimal effects on heart rate. Oral absorption in dogs is improved over other urea analogs.

Human beta3 adrenergic receptor agonists containing imidazolidinone and imidazolone benzenesulfonamides

The cyclopentylpropylimidazolidinone L-766,892 is a potent beta3 AR agonist (EC50 5.7 nM, 64% activation) with 420- and 130-fold selectivity over binding to the beta1 and beta2 ARs, respectively. In anesthetized rhesus monkeys, L-766,892 elicited dose-dependent hyperglycerolemia (ED50 0.1 mg/kg) with minimal effects on heart rate.

A polyadenylylation-specific RNA-contact site on the surface of the bifunctional vaccinia virus RNA modifying protein VP39 that is distinct from the mRNA 5' end-binding "cleft"

VP39 is a bifunctional mRNA-modifying protein that acts as both an mRNA cap-specific 2'-O-methyltransferase and a processivity factor for VP55, the vaccinia poly(A) polymerase catalytic subunit. Although regions of the protein surface required for methyltransferase function are well defined, it has been unclear whether the protein polyadenylylation function requires direct RNA contact and, if so, where the contact site(s) might be located on the protein surface. Here, we show that the VP55-VP39 heterodimer forms a stable complex with a 50mer oligonucleotide bearing a U2-N25-U motif, as opposed to the U2-N15-U motif that is optimal for stable complex formation with VP55 alone. An oligonucleotide bearing a U2-N25-U motif in which the downstream U residue is replaced with 4thioU can be efficiently photocrosslinked to VP39, but only in the context of the VP55-VP39 heterodimer. By partial proteolysis of end-labeled VP39, the site of oligonucleotide photocrosslinking was localized to the region of VP39 between residues Lys90 and Arg122. Peptide microsequencing and confirmatory mutagenesis identified the side-chain of Arg107 as the photocrosslinking site. Substitution of this residue with lysine abolished photocrosslinking entirely, consistent with the established RNA binding role of arginine in other RNA-binding proteins. This study provides clear evidence for a polyadenylylation-specific RNA-contact site on the surface of VP39, which is distinct from the RNA-binding methyltransferase "cleft" characterized in recent crystallographic and biochemical studies.

Cloning and expression of a gene encoding a Campoletis sonorensis polydnavirus structural protein

Polydnaviruses are the only known group of mutualistic viruses. They are required for successful parasitization in many braconid and ichneumonid parasitoids. The intimacy of this mutualistic association is indicated by the integration and vertical transmission of polydnaviruses in wasp genomes and by their asymptomatic, developmentally regulated replication. The evolution of this mutualism raises several interesting issues that require a better understanding of the viral genome and viral replication. To develop probes for virus replication and morphogenesis, we have begun to characterize several viral structural proteins. A 699 bp cDNA encoding the p12 viral structural protein was cloned and sequenced. The p12 gene localizes to viral segment Y and encodes a predicted protein of 92 amino acids that does not encode a signal peptide and is unrelated to known peptide or nucleic acid sequences. The p12 mRNA is detected at the onset of virus replication. mRNA titers increase with increasing rates of virus replication. Polyclonal antisera raised against histidine-tagged p12 protein expressed in bacteria reacted specifically with the p12 polypeptide in Western blots of CsPDV virions. The p12 polypeptide was not detected in non-replicative wasp or lepidopteran tissues by Western blot analyses but was readily detected in protein extracts of wasp ovaries. The data indicate that the p12 gene is a viral gene encoding a virion protein and provides a specific probe for virus replication that will be useful for studying the evolution of this group of mutualistic viruses.

[Primary study of differentially expressed cDNA sequences in cell line HNE1 of human nasopharyngeal carcinoma by cDNA representational difference analysis]

OBJECTIVE

To search differentially expressed sequences correlated with pathogenesis of human nasopharyngeal carcinoma (NPC), including the candidates of tumor suppressor genes.

METHODS

cDNA representational difference analysis (RDA) was performed to isolate differentially expressed sequences between cDNA from normal human primary cultures of nasopharyngeal epithelial cells and cDNA from NPC cell line HNE1. The sources of differentially expressed products were proved by Southern blot and Northern blot. The fragments were cloned with pGEM-T easy kit and sequenced by the chain termination reaction.

RESULTS

Four differentially expressed cDNA fragments were isolated in the fourth subtractive hybridization using cDNA from normal human primary cultures of nasopharyngeal epithelial cells as tester amplicon and cDNA from NPC cell line HNE1 as driver amplicon by cDNA RDA. These differential cDNA fragments revealed that they really came from the tester amplicon and were not expressed or down-regulated in the NPC HNE1 cells. Of these obtained clones, some are the fragments of the human known genes including house-keeping genes, the others are novel genes.

CONCLUSION

NPC involves alteration of multiple genes. Some of known genes matched with the differentially expressed sequences have an effective suppressive ability on the carcinoma.

[Effects of the new compound-XW630 on osteoblast]

This study aimed to observe the influence of the new compound-XW630 on the proliferation of osteoblast, ALP action, and the forming of osteoclast. The MTT method and the alkaline phosphatase method were adopted to investigate the influence of XW630 on ALP action and the proliferation of osteoblast cultured from grown rat's skull. The Tartrate-resistant acid phosphatase dyeing method was used to observe the influence of XW630 on forming of cultured osteoclast in vitro. The result showed that, when XW630 concentration was 10(-6)-10(-8) mol/L, it obviously enhanced the proliferation of osteoblast and improved the activity of ALP, and it evidently provented PTH from stimulating the forming of osteoclast. It is concluded that XW630 is obviously effective for stimulating the proliferation of cultivated osteoblast in vitro and for inhibiting the forming of osteoclast.

3-Pyridylethanolamines: potent and selective human beta 3 adrenergic receptor agonists

The 3-pyridylethanolamine L-757,793 is a potent beta 3 AR agonist (EC50 6.3 nM, 70% activation) with 1,300- and 500-fold selectivity over binding to the beta 1 and beta 2 ARs, respectively. L-757,793 stimulated lipolysis in rhesus monkeys (ED50 0.2 mg/kg) with a maximum response equivalent to that elicited by isoproterenol.

[Establishment of partial gene expression map of 7q32 in nasopharyngeal carcinoma and primary culture normal nasopharyngeal epithelial cells]

OBJECTIVE

To establish partial gene expression map of 7q32 in nasopharyngeal carcinoma (NPC) cell line, tissues and primary culture normal nasopharyngeal epithelial cells.

METHODS

We detected the expression of 20 ESTs at 7q32 in NPC cell line HNE1,13 NPC biopsies and primary culture normal nasopharyngeal epithelial cells using differential RT PCR and Northern hybridization.

RESULTS

8 ESTs (AA188181, AA13079,N27556, AA031919, N22721, H20825, T91284, AA001936) expressed equally in both of HNE1 and primary culture normal nasopharyngeal epithelial cells; 7 ESTs (T64215, AA025822, R60014,R80002,H06688, R60192,R95096) expressed in neither of them; 3 ESTs (H19830,W72688,AA130630) overexpressed in HNE1 ; and 2 ESTs (AA070437, H90882) overexpressed in primary culture normal nasopharyngeal epithelial cells. W72688 and H19830 each overexpressed in 77%(10/13) of NPC biopsies; AA070437 down-expressed in 30.7% of NPC biopsies.

CONCLUSION

Partial gene expression map of 7q32 in nasopharyngeal carcinoma cell line ,tissues and primary culture normal nasopharyngeal epithelial cells has been established. The up-regulation of W72688, H19830 and down-regulation of AA070437 may be related to the occurrence of NPC.

Synthesis, cancericidal and antimicrotubule activities of 3-(haloacetamido)-benzoylureas

The four title compounds (not hitherto reported) were synthesized from 3-aminobenzoic acid through its trifluoroacetic acid-acid chloride derivative, reaction with urea and aminolytic deprotection to yield 3-aminobenzoylurea, followed by unconventional haloacetylation. Three key factors were found essential for antitumor activity: (i) the cytotoxic nature of the halogen: I > Br > Cl > F (ID90 0.014->10 microM); (ii) the position of the halogen: only the 3-position (meta) expressed relevant activity; and (iii) the presence of the urea group (1-position). The selectivity of the bromo and iodo compounds were higher than those of vinblastine and paclitaxel in terms of cytotoxicity (ID50 ratios in nonmalignant myocardial fibroblasts and CEM leukemia cells) and therapeutic indices (P338 leukemia bearing mice). Relevant mechanisms of bioactivity were mitotic arrest and apoptosis. Complete inhibition of microtubule assembly occurred in cell-free systems (at 2.8 versus 2.1 microM for vinblastine); in contrast to paclitaxel, the target compounds did not interfere with microtubule disassembly. The strong cancericidal and antimicrotubular activities of the bromine and iodine compounds justify further exploration of their potential in antineoplastic chemotherapy.

A common region of allelic loss on chromosome region 3p25.3-26.3 in nasopharyngeal carcinoma

Loss of heterozygosity (LOH) of chromosome arm 3p has been commonly observed in carcinomas of various tissues, including those of nasopharyngeal carcinoma (NPC). To determine the frequency and extent of allelic loss in NPC, we investigated 16 loci on chromosome bands 3p21-26 in 24 tumor tissues by microsatellite analysis. LOH on 3p21-26 was found in 16 of 24 (66.7%) tumors. The highest frequency of allelic loss was found in two adjacent loci, D3S1620 (11/22, 50%) and D3S1560 (9/18, 50%). Eight cases showed LOH in one contiguous region and 5 cases in more than one region. Samples 1, 3, 4, 7, 8, 10, 16, 17, 18, 19, and 22 had a contiguous stretch of allelic loss between D3S1297 and D3S1597. The smallest common LOH/deletion region seems likely to lie between D3S1297 (3p26.3-26.2) and D3S1560 (3p25.3). The allelic loss map defined here will facilitate finer mapping of putative tumor suppressor gene loci and positional cloning of such genes, which may play a role in carcinogenesis of NPC.

3-Pyridyloxypropanolamine agonists of the beta 3 adrenergic receptor with improved pharmacokinetic properties

Pyridyloxypropanolamines L-749,372 (8, beta 3 EC50 = 3.6 nM) and L-750,355 (29, beta 3 EC50 = 13 nM) are selective partial agonists of the human receptor, with 33% and 49% activation, respectively. Both stimulate lipolysis in rhesus monkeys (ED50 = 2 and 0.8 mg/kg, respectively), with minimal effects on heart rate. Oral bioavailability in dogs, 41% for L-749,372 and 47% for L-750,355, is improved relative to phenol analogs.

[Allelic loss on chromosome 3p21-26 in nasopharyngeal carcinoma]

OBJECTIVE

To determine the frequency and extent of loss of heterozygosity (LOH) on chromosome 3p in nasopharyngeal carcinoma (NPC).

METHODS

Sixteen loci on chromosome bands 3p21-26 in 24 tumors was studied by using microsatellite analysis.

RESULTS

LOH on 3p21-26 was found in 16 of 24 tumors (66.7%). The highest frequency of the allelic loss was found in two adjacent loci D3S1620(50%, 11/22) and D3S1560 (50%, 9/18). Eight cases showed LOH in one contiguous region and 5 cases in more than one region. Sample 1, 3, 4, 7, 8, 10, 16, 17, 18, 19, and 22 had a contiguous stretch of allelic loss between D3S1297 and D3S1597.

CONCLUSION

The smallest common LOH/deletion region seems likely to lie between D3S1620(3p26.2-26.3) and D3S1560(3p25.3). The allelic loss map defined here will facilitate finer mapping of putative tumor suppressor gene loci and positional cloning of such genes, which may play a role in carcinogenesis of NPC.

[Regulatory factors of osteogenic phenotypical experession by fibroblasts in vitro]

In order to explore further the regulatory factors to the potentiality in inducing osteogenesis by fibroblasts, the fibroblasts were isolated, and purified from human skin, and were grown in incubation in the media of EGF, IL-6, TNF-alpha and BMP2 at different concentrations for two weeks, then, the markers for osteogenic features were investigated by biochemistry, histochemistry and electron microscopic observations. It was found that the combined use of TNF-alpha and BMP2 could stimulate fibroblasts to secrete alkaline phosphatase, osteocalcin and collagen, and the morphological changes of the fibroblasts were also very striking. In the extracellular matrix, the collagen fibrils, with or without periodicity, were arranged regularly or randomly oriented, and numerous minute calcium granules were interspersed among them. The fibroblasts were interwoven one on top of another in the form of multilayer structure and on the surface, there were secreting granules and piling up of calcium crystals which coalessed steadily and increased in size in forming bony nodules. It was considered that TNF-alpha and BMP2 were capable of inducing the fibroblasts to form bone.

A selective human beta3 adrenergic receptor agonist increases metabolic rate in rhesus monkeys

Activation of beta3 adrenergic receptors on the surface of adipocytes leads to increases in intracellular cAMP and stimulation of lipolysis. In brown adipose tissue, this serves to up-regulate and activate the mitochondrial uncoupling protein 1, which mediates a proton conductance pathway that uncouples oxidative phosphorylation, leading to a net increase in energy expenditure. While chronic treatment with beta3 agonists in nonprimate species leads to uncoupling protein 1 up-regulation and weight loss, the relevance of this mechanism to energy metabolism in primates, which have much lower levels of brown adipose tissue, has been questioned. With the discovery of L-755,507, a potent and selective partial agonist for both human and rhesus beta3 receptors, we now demonstrate that acute exposure of rhesus monkeys to a beta3 agonist elicits lipolysis and metabolic rate elevation, and that chronic exposure increases uncoupling protein 1 expression in rhesus brown adipose tissue. These data suggest a role for beta3 agonists in the treatment of human obesity.

Discovery of L-755,507: a subnanomolar human beta 3 adrenergic receptor agonist

A study of 4-acylaminobenzenesulfonamides in a cloned human beta 3 adrenergic receptor assay resulted in the discovery of n-hexylurea, L-755,507 (22). This 0.43 nM beta 3 agonist, which is > 440-fold selective over both beta 1 and beta 2 binding, is among the most potent human beta 3 agonists reported to date.

Modulation of ceramide-activated protein phosphatase 2A activity by low molecular weight aromatic compounds

Protein phosphatase 2A (PP2A) is one of the most important and abundant serine/threonine phosphatases in mammalian tissues and plays a role in gene expression, cell division, and signal transduction. PP2A is activated by ceramide, which is produced by the hydrolysis of membrane sphingomyelin in response to a variety of stress-related stimuli. To further study the role of ceramide-mediated signal transduction in cellular processes such as senescence and apoptosis, we designed and synthesized a series of low molecular weight aromatic compounds, mainly of the isoquinolone and tetralone classes, and evaluated their ability to inhibit enzymes known to be activated by ceramide. Those enzymes studied were ceramide-activated protein kinase, protein kinase C zeta and PP2A. Of these, only PP2A was found to be inhibited. A few of the compounds inhibited both ceramide-activated as well as basal PP2A activity. In addition, several of the compounds activated PP2A by up to 300% above basal enzyme activity, but only in the presence of ceramide. Thus, modulation (both inhibition and activation) of the catatylic activity of ceramide-activated PP2A is demonstrated by certain low molecular weight aromatic compounds.

Electrospray ionization mass spectrometric and liquid chromatographic-mass spectrometric studies on the metabolism of synthetic dynorphin A peptides in brain tissue in vitro and in vivo

Metabolic stability of synthetic dynorphins [N-terminal fragments of dynorphin A (Dyn A)] were evaluated in vitro and in vivo. These peptides were applied at concentrations 100-1000 times higher than those of the endogenous dynorphins. Degradation kinetics of these peptides were studied in rat brain homogenate by using microbore gradient RP-LC assay, and limited information on their metabolism was obtained by electrospray ionization mass spectrometry (ESI-MS) of the isolated metabolites. In vivo cerebral microdialysis, in which the peptides were introduced via the probe placed in striatum region of the brain of the experimental animals, was used to circumvent contamination arising from autoproteolysis of brain during incubation of the samples in vitro. Metabolites of Dyn A (1-13) and Dyn A (1-11) were identified from electrospray ionization mass spectra of the microdialysates without chromatographic separation; the identification of peptides in the mixtures were supported by medium resolution ESI Fourier-transform ion cyclotron resonance MS. LC-MS was used to fully characterize the complex peptide mixture obtained after the striatal perfusion of Dyn A (1-12).

Vaccinia NPH-I, a DExH-box ATPase, is the energy coupling factor for mRNA transcription termination

Vaccinia virus RNA polymerase terminates transcription in response to a specific signal UUUUUNU in the nascent RNA. Transduction of this signal to the elongating polymerase requires a trans-acting viral termination factor (VTF/capping enzyme), and is coupled to the hydrolysis of ATP. Recent studies suggest that ATP hydrolysis is catalyzed by a novel termination protein (factor X), which is tightly associated with the elongation complex. Here, we identify factor X as NPH-I (nucleoside triphosphate phosphohydrolase-I), a virus-encoded DNA-dependent ATPase of the DExH-box family. We report that NPH-I serves two roles in transcription (1) it acts in concert with VTF/CE to catalyze release of UUUUUNU-containing nascent RNA from the elongation complex, and (2) it acts by itself as a polymerase elongation factor to facilitate readthrough of intrinsic pause sites. A mutation (K61A) in the GxGKT motif of NPH-I abolishes ATP hydrolysis and eliminates the termination and elongation factor activities. Related DExH proteins may have similar roles at postinitiation steps during cellular mRNA synthesis.

[Bioassay of TNF-alpha in synovial fluid and ultrastructural observation of synovium from patients with osteoarthritis]

OBJECTIVE

To better define the role of synovium in the pathogenesis of osteoarthritis (OA).

METHODS

We measured the bioactivity of tumor necrosis factor-alpha(TNF-alpha) in synovial fluid (SF) and examined the histologic and ultrastructural features of the synovium from patients with OA and from patients with acute and chronic traumatologic joint.

RESULTS

The results showed that the levels of TNF-alpha in SF from OA were significantly elevated. Marked fibrosis and thickened intima were found in OA synovium, with much dense collagen, which, in some cases, was banded, but no specific inflammatory changes were detected. Type B cells in OA synovium had the characteristics of organelles of cells active in synthesizing and secreting protein. Type A cells in OA synovium had the features of the macrophage.

CONCLUSION

Evident fibrosis in synovium may be either mediated by the cartilage degradation product or by the enhanced joint damage process in OA.

Investigation of suramin-albumin binding by electrospray mass spectrometry

Suramin, an organic polyanion with six sulphonic groups, is under clinical trials as an agent against hormone-refractory prostate cancer. The drug binds strongly to serum albumin. The objectives were to use electrospray to measure the molecular masses of the intact complexes of albumin and suramin to determine the number of suramin molecules bound under different molar ratios, and to investigate the binding of suramin in human serum. With albumin in excess (2:1 to 25:1 ratio), only 1 and 2 bound suramins were found; with suramin excess (2:1 to 1000:1) up to 20 bound suramin molecules/albumin were found. Up to 5 bound suramins were found in human serum with 4:1 suramin:albumin ratio, which corresponds to recommended therapeutic doses (200-300 micrograms/mL). At 8:1 ratio, which would be toxic, complexes with up to ten bound suramin molecules were found, and unreacted albumin diminished.

Elongation properties of vaccinia virus RNA polymerase: pausing, slippage, 3' end addition, and termination site choice

We have analyzed the elongation properties of vaccinia virus RNA polymerase during a single round of transcription in vitro. RNA-labeled ternary complexes were halted at a unique template position located upstream of a T-run (TTTTTTTTT) in the nontemplate strand; this element encodes an RNA signal for factor-dependent transcription termination at distal sites on the template. The halted ternary complexes were purified and allowed to resume elongation under a variety of conditions. We found that the T-run constituted a strong elongation block, even at high nucleotide concentrations. The principal sites of pausing were at a C position situated two nucleotides upstream of the first T in the T-run and at the first three to four T positions within the T-run. There was relatively little pausing at the five downstream Ts. Intrinsic pausing was exacerbated at suboptimal nucleotide concentrations. Ternary complexes arrested by the T-run at 10 microM NTPs rapidly traversed the T-run when the NTP pool was increased to 1 mM. Limiting GTP (1 microM) resulted in polymerase stuttering at the 3' margin of the T-run, immediately prior to a templated G position; this generated a ladder of slippage synthesis products. We found that vaccinia ternary complexes remained intact after elongating to the very end of a linear DNA template and that such complexes catalyzed the addition of extra nucleotides to the 3' end of the RNA chain. The 3' end addition required much higher concentrations of NTPs than did templated chain elongation. Finally, we report that factor-dependent transcription termination by vaccinia RNA polymerase downstream of the T-run was affected by nucleotide concentration. Limiting UTP caused the polymerase to terminate at sites closer to the UUUUUNU termination signal. This is consistent with the kinetic coupling model for factor-dependent termination.

Specific recognition of an rU2-N15-rU motif by VP55, the vaccinia virus poly(A) polymerase catalytic subunit

VP55, the vaccinia poly(A) polymerase catalytic subunit, interacts with oligonucleotide primers via two uridylate recognition sites (Deng, L., and Gershon, P. D. (1997) EMBO J. 16, 1103-1113). Here, we show that the cognate RNA sequence comprises a 5'-rU2-N15-rU-3' motif (where N = any deoxyribo or ribonucleotide), embedded within oligonucleotide primers 29-30 nucleotides (nt), or greater, in length. Nine residues separate the 3'-most ribouridylate of the optimally positioned motif from the primer 3'-OH. A ribose sugar at the extreme 3'-terminal nucleotide of the primer is absolutely required for VP55's adenylyltransferase activity, but not for stable VP55-RNA interaction. A ribose at position -3 markedly stimulates both adenylyltransferase activity and stable binding. The use of uridine analogs indicated (i) those functional groups of the uracil base which contribute to stable VP55-primer interaction, and (ii) that VP55's ability to discriminate uracil from cytosine stems largely from the requirement for a protonated N3 nitrogen within the pyrimidine ring. The rU2-N15-rU motif was identified within the uridylate-rich 3' end of a naturally occurring vaccinia mRNA. However, oligonucleotides whose only internal uridylates comprised the motif supported only a 3-5-nt processive burst of oligo(A) tail addition, as opposed to the approximately 30-35-nt burst observed with the naturally occurring 3' end.

Structure-function analysis of the triphosphatase component of vaccinia virus mRNA capping enzyme

The N-terminal 60 kDa (amino acids 1 to 545) of the D1 subunit of vaccinia virus mRNA capping enzyme is an autonomous bifunctional domain with triphosphatase and guanylyltransferase activities. We previously described two alanine cluster mutations, R77 to A (R77A)-K79A and E192A-E194A, which selectively inactivated the triphosphatase component. Here, we characterize the activities of 11 single alanine mutants-E37A, E39A, Q60A, E61A, T67A, T69A, K75A, R77A, K79A, E192A, and E194A-and a quadruple mutant in which four residues (R77, K79, E192, and E194) were replaced by alanine. We report that Glu-37, Glu-39, Arg-77, Glu-192, and Glu-194 are essential for gamma-phosphate cleavage. The five essential residues are conserved in the capping enzymes of Shope fibroma virus, molluscum contagiosum virus, and African swine fever virus. Probing the structure of D1(1-545) by limited V8 proteolysis suggested a bipartite subdomain structure. The essential residue Glu-192 is the principal site of V8 cleavage. Secondary cleavage by V8 occurs at the essential residue Glu-39. The triphosphatase-defective quadruple mutant transferred GMP to the triphosphate end of poly(A) to form a tetraphosphate cap structure, GppppA. We report that GppppA-capped RNA is a poor substrate for cap methylation by the vaccinia virus and Saccharomyces cerevisiae RNA (guanine-7) methyltransferases. The transcription termination factor activity of the D1-D12 capping enzyme heterodimer was not affected by mutations that abrogated ATPase activity. Thus, the capping enzyme is not responsible for the requirement for ATP hydrolysis during transcription termination.

Chemical approaches toward understanding base excision DNA repair

Despite the importance of DNA repair in protecting the genome, the molecular basis for damage recognition and repair remains poorly understood. In the base excision repair pathway (BER), DNA glycosylases recognize and excise damaged bases from DNA. This review focuses on the recent development of chemical approaches that have been applied to the study of BER enzymes. Several distinctive classes of noncleavable substrate analogs that form stable complexes with DNA glycosylases have recently been designed and synthesized. These analogs have been used for biochemical and structural analyses of protein-DNA complexes involving DNA glycosylases, and for the isolation of a novel DNA glycosylase. An approach to trap covalently a DNA glycosylase-intermediate complex has also been used to elucidate the mechanism of DNA glycosylases.

Phylogeny of mRNA capping enzymes

The m7GpppN cap structure of eukaryotic mRNA is formed cotranscriptionally by the sequential action of three enzymes: RNA triphosphatase, RNA guanylyltransferase, and RNA (guanine-7)-methyltransferase. A multifunctional polypeptide containing all three active sites is encoded by vaccinia virus. In contrast, fungi and Chlorella virus encode monofunctional guanylyltransferase polypeptides that lack triphosphatase and methyltransferase activities. Transguanylylation is a two-stage reaction involving a covalent enzyme-GMP intermediate. The active site is composed of six protein motifs that are conserved in order and spacing among yeast and DNA virus capping enzymes. We performed a structure-function analysis of the six motifs by targeted mutagenesis of Ceg1, the Saccharomyces cerevisiae guanylyltransferase. Essential acidic, basic, and aromatic functional groups were identified. The structural basis for covalent catalysis was illuminated by comparing the mutational results with the crystal structure of the Chlorella virus capping enzyme. The results also allowed us to identify the capping enzyme of Caenorhabditis elegans. The 573-amino acid nematode protein consists of a C-terminal guanylyltransferase domain, which is homologous to Ceg1 and is strictly conserved with respect to all 16 amino acids that are essential for Ceg1 function, and an N-terminal phosphatase domain that bears no resemblance to the vaccinia triphosphatase domain but, instead, has strong similarity to the superfamily of protein phosphatases that act via a covalent phosphocysteine intermediate.

Mutation effect of high altitude balloon flight on rice and green pepper seeds

Dry seeds of rice and green pepper were carried in the basket of a high altitude balloon to 30-40 km for 8 h. The treated seeds were planted on the ground and characters of these seeds and their progenies, such as development, fruiting, disease resistance were observed. The results showed that the SP2 generation of the treated rice showed strong mutation. A Japonica male fertility restorer rice line was found out. It could be hybridized with sterile line of Indica rice, and their progeny had strong hybrid vigor, high setting percentage and good plumpness of grain. Disease resistance, high-yield, big-fruit and high vitamin C content strains were selected from the progenies of treated green pepper seeds. The above results indicated that the special conditions in high altitude could produce a variety of mutations and most of them are hereditable. Therefore, high altitude balloon flight can be used as a new method of mutation breeding.

Interplay of two uridylate-specific RNA binding sites in the translocation of poly(A) polymerase from vaccinia virus

The VP55 (catalytic) subunit of vaccinia virus heterodimeric poly(A) polymerase (PAP) contacts 31-40 nucleotide segments of RNA in a uridylate-dependent manner, and effects the rapid, processive addition of a 30 nt oligo(A) tail. Here, the minimum size of uridylate-containing RNA required for stable VP55 interaction was refined to 33-34 nt. VP55 binding experiments using a set of sixteen 34 nt DNA-RNA chimeras, each containing a differently positioned tetra-uridylate cluster within an oligo(dC) background, indicated that the protein contacts uridylates at two positions within the oligonucleotide. Combination of two optimally positioned tetra-uridylate clusters into a single oligonucleotide fully restored the properties of an optimal substrate, rU34, in VP55 binding and salt-resistant polyadenylylation. The positions of the two uridylate interaction sites, approximately 10 and approximately 25 nt from the oligonucleotide 3' OH, were confirmed using a selection scheme employing dC-rU oligonucleotide chimera pools. These and additional data suggest a mechanism for polymerase translocation with respect to RNA comparable with inchworming models of transcriptional elongation. In selection experiments incorporating the PAP-associated processivity factor VP39, the latter was shown to replace the 3' OH-distal uridylate contact site with one approximately 10 nt further upstream.

Detection and analysis of the growth characteristics of Proteus vulgaris with a bulk acoustic wave ammonia sensor

A bulk acoustic wave ammonia sensor to monitor the growth of Proteus vulgaris is described. The corresponding bacterial growth response equation was derived based on the basic growth characteristics of P. vulgaris, and was verified experimentally. The application of the equation to the estimation of kinetic parameters (such as the asymtote, the maximum specific growth rate and the lag time) was accomplished successfully. The generation time is 33.3 min at 37 degrees C. The influence of temperature on bacterial growth was also investigated and the activation energy of P. vulgaris growth was estimated. Furthermore, the initial bacterial concentrations were determined based on the linear relationship between the inflection time, ti, and the logarithm of the initial bacterial concentration in the range 10(2)-10(7) (cells ml-1). The results were in good agreement with those from the pour plate count method and the precision was better than that of the frequency detection time method.

Transcription termination by vaccinia RNA polymerase entails recognition of specific phosphates in the nascent RNA

Vaccinia virus RNA polymerase terminates transcription downstream of a UUUUUNU signal in the nascent RNA. Transduction of the RNA signal to the elongating polymerase requires a termination factor (vaccinia termination factor/capping enzyme) and is coupled to the hydrolysis of ATP. It was shown previously that incorporation of 5-bromouracil or 5-iodouracil within the UUUUUNU element abolishes termination by preventing factor-dependent release of the nascent chain from the polymerase elongation complex. Here, we report that termination is prevented by phosphorothioate substitution at UMP residues in the nascent RNA. In contrast, phosphorothioate substitution at AMP, CMP, and GMP nucleotides does not inhibit termination. Thus, the action of a eukaryotic termination factor entails recognition of the nucleotide bases and the phosphate groups of the target sequence in nascent RNA.

Biosynthesis of teichuronic acid in the bacterial cell wall. Purification and characterization of the glucosyltransferase of Micrococcus luteus

This report describes what is, to our knowledge, the first purification to near homogeneity of an enzyme involved in the biosynthesis of the teichuronic acid of Micrococcus luteus cell walls. The glucosyltransferase of M. luteus, which participates in the biosynthesis of teichuronic acid, was solubilized from cytoplasmic membrane fragments by extraction with buffer solutions containing the detergents Thesit (dodecyl alcohol polyoxyethylene ether; 1 mg/ml) and 3-[(3-cholamidopropyl)dimethylammonio]-1-propanesulfonate (0.5 mg/ml). The detergent-solubilized enzyme was purified 150-fold, with a recovery of 13% by adsorbent column chromatography, ion-exchange chromatography, gel filtration, and preparative nondenaturing gradient polyacrylamide gel electrophoresis. On the basis of its mobility on native gradient gel, the glucosyltransferase was estimated to have a molecular mass of 440 kDa. The purified native enzyme was a multisubunit protein consisting of subunits of two sizes; their molecular masses were determined to be 52.5 and 54 kDa, respectively, by observation of the mobility of the protein bands in sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The isoelectric point of the enzyme was approximately 5.

Polyprenylphosphate-pentoses in mycobacteria are synthesized from 5-phosphoribose pyrophosphate

Polyprenylphosphate-arabinose (in which the polyprenyl unit is found both as decaprenyl and octahydroheptaprenyl) is a donor of mycobacterial cell wall arabinosyl residues. Because of this important role, its biosynthetic pathway, and that of the related lipid, polyprenylphosphate-D-ribose, was investigated. Surprisingly, phosphoribose pyrophosphate was shown to be a key intermediate on the pathway to both polyprenylphosphate-D-pentoses. Thus, incubation of 5-phospho-D-[14C]ribose pyrophosphate with membranes prepared from Mycobacterium smegmatis resulted in the presence of organic-soluble radioactivity that was shown to be, in part, polyprenylphosphate-[14C]arabinose and polyprenylphosphate-[14C]ribose. Two additional intermediates, polyprenylphosphate-5-phospho[14C]ribose and polyprenylphosphate-5-phospho[14C]arabinose, were identified. Further experiments showed that the mature polyprenylphosphate-ribose is formed from phosphoribose pyrophosphate via a two-step pathway involving a transferase to form polyprenylphosphate-5-phosphoribose and then a phosphatase to form the final polyprenylphosphateribose. Polyprenylphosphate-arabinose is formed by a similar pathway with an additional step being the epimerization at C-2 of the ribosyl residue. This epimerization occurs at either the level of phosphoribose pyrophosphate or at the level of polyprenylphosphate-5-phosphoribose.

An ATPase component of the transcription elongation complex is required for factor-dependent transcription termination by vaccinia RNA polymerase

Vaccinia virus RNA polymerase terminates transcription in response to a specific signal UUUUUNU in the nascent transcript. Transduction of this signal to the elongating polymerase requires a virus-encoded termination factor, VTF. The existence of a second termination factor was suggested by the finding that transient exposure of purified elongation complexes to heparin rendered them refractory to VTF-induced termination. Loss of termination competence correlated with the removal of several polypeptide components of the elongation complex. We present the identification of factor X, an activity that restored VTF responsiveness to heparin-stripped ternary complexes. We propose that factor X, which has an associated DNA-dependent ATPase activity, mediates the requirement for ATP hydrolysis during transcription termination.

The study of DNA oxidative damage in benzene-exposed workers

Peripheral blood lymphocyte 8-hydroxy-2-deoxyguanosine (8-OHdG), were detected in 87 benzene-exposed and 30 control subjects by high performance liquid chromatograph coupled with an electrochemical detector system (HPLC-EC). The air concentration of benzene and its homologes in the workplace, urinary trans,trans-muconic acid (TTMA) as an internal dose of benzene exposure, were examined. The lymphocyte micronuclei (MN) as genotoxic and white blood cell (WBC) count as well as the myelotoxic markers of benzene were examined. Exposure to low, medium and high concentrations of benzene resulted in increased levels of 8-OHdG, which were 4.67, 26.12 and 29.89/10(5) dG, respectively, However, the 8-OHdG level observed in the control group was 3.738/10(5) dG). A good correlation between 8-OHdG formation and the groups exposed to external and internal benzene was observed (r = 0.77, 0.64, respectively). There was also a correlation between 8-OHdG and MN formation (r = 0.50). WBC levels were within normal range in all benzene-exposed subjects. It may be concluded that: benzene induced DNA oxidative damage in occupational exposure workers. The major factors influencing blood the 8-OHdG level were sex and toluene.