[A gas chromatographic method for determination of Butyraldehyde as a product of butanol biotransformation in rat liver]

Analysis of butyraldehyde obtained by the interaction of butanol with cytochrome P450 II E1 in rat liver microsomes prepared by centrifugation and with the NADPH added is described in this paper. The biotransformation rate of butanol into butyraldehyde can be used as an index for the assessment of the enzyme activity of cytochrome P450 II E1. A headspace gas chromatograghic method to determine the butyraldehyde has been developed. The detection limit and CV of this method for butyraldehyde in microsomes were 0.7 micromol/L and 8.1%-9.3% respectively. The recovery was 85.3%. The results show that this is a rapid and sensitive method with less interferences and fairly good precision. The method developed has made a reliable analytical methodological foundation for the assessment of the enzyme activity of cytochrome P450 II E1.

[GC-MS analysis of essential oils from the pericarps of Illicium majus Hook.f.et. Thoms. and I. micranthum Dunn]

The chemical constituents of essential oils from the pericarps of Illicium majus and I. micranthum were analyzed. Seventy-two compounds have been identified by GC-MS, of which safrole, linalool and limonene are higher in content.

A newly developed PCR assay of H. pylori in gastric biopsy, saliva, and feces. Evidence of high prevalence of H. pylori in saliva supports oral transmission

We have recently developed a new PCR assay for the detection of H. pylori. In this study, the polymerase chain reaction (PCR) assay was used to detect H. pylori in 88 gastric biopsy, 85 saliva, and 71 fecal specimens from 88 patients. H. pylori infection was confirmed in 71 of 88 patients by culture and/or histological stain of gastric biopsies. Serum IgG antibody to H. pylori was also measured and resulted in 97% sensitivity and 94% specificity. H. pylori DNA was detected by the PCR assay in gastric biopsy specimens from all 71 patients (100% sensitivity) with proven gastric H. pylori infection but not from 17 noninfected patients (100% specificity). In saliva specimens, H. pylori DNA was identified in 57 of the 68 patients (84%) with proven gastric H. pylori infection and in three of the 17 patients without gastric H. pylori infection. However, the PCR assay was only able to detect H. pylori DNA in the feces from 15 of 61 patients (25%) with proven gastric H. pylori infection and one of the 10 patients without gastric H. pylori infection. The results show that the PCR assay is reliable for detecting the presence of H. pylori in gastric biopsy and saliva specimens. The data indicate that H. pylori exists in a higher prevalence in saliva than feces and that the fecal-oral route may be an important means of transmission of this infection in developing countries but not as significant as previously suspected in the developed countries. It is likely that the oral-oral route is more prominent.

Human rhinovirus 3 at 3.0 A resolution

BACKGROUND

The over 100 serotypes of human rhinoviruses (HRV) are major causative agents of the common cold in humans. These HRVs can be roughly divided into a major and minor group according to their cellular receptors. They can also be divided into two antiviral groups, A and B, based on their sensitivity to different capsid-binding antiviral compounds. The crystal structures of HRV14 and HRV16, major-receptor group rhinoviruses, as well as HRV1A, a minor-receptor group rhinovirus, were determined previously. Sequence comparisons had shown that HRV14 seemed to be an outlier among rhinoviruses. Furthermore, HRV14 was the only virus with no cellular 'pocket factor' in a hydrophobic pocket which is targeted by many capsid-binding antiviral compounds and is thought to regulate viral stability. HRV3, another major-receptor group virus, was chosen for study because it is one of a subset of serotypes that best represents the drug sensitivity of most rhinovirus serotypes. Both HRV3 and HRV14 belong to antiviral group A, while HRV16 and HRV1A belong to antiviral group B.

RESULTS

HRV3 was found to be very similar to HRV14 in sequence and structure. Like HRV14, crystallized HRV3 also has no bound pocket factor. The structure of HRV3 complexed with an antiviral compound, WIN56291, was also determined and found to be similar to the same antiviral compound complexed with HRV14.

CONCLUSIONS

The amino-acid sequence and structural similarity between HRV3 and HRV14 suggests that rhinoviruses in the same antiviral group have similar amino-acid sequences and structures. The similar amino-acid composition in the pocket region and the viral protein VP1 N termini in all known group B HRV sequences suggests that these viruses may all contain pocket factors and ordered N-terminal amphipathic helices in VP1. Both of these factors contribute to viral stability, which is consistent with the observations that group B rhinoviruses have a higher chance of successful transmission from one host to another and is a possible explanation for the observed higher pathogenicity of these rhinoviruses.

Effects of anti-peptide antibodies against the second extracellular loop of human M2 muscarinic acetylcholine receptors on transmembrane potentials and currents in guinea pig ventricular myocytes

The effects of anti-peptide antibodies against the second extracellular loop of human M2 muscarinic receptor on transmembrane potentials and currents in guinea pig single ventricular cells were analyzed using whole-cell patch clamp technique. These effects were compared with those of the muscarinic receptor agonists carbachol and acetylcholine. The antibodies shortened the action potential duration in a dose-dependent manner. By using a ramp or step rectangular pulse protocol, it was found that the antibodies increased the outward K+ current and decreased the inward basal ICa significantly. The reversal potential of both carbachol- and antibody-induced extra currents were close to -80 mV, being in proximity to the calculated Ek of -90 mV. A beta-adrenergic receptor agonist, isoprenaline, prolonged the action potential and increased the overshoot which could be inhibited by both antibody and carbachol. Isoprenaline increased inward ICa and outward Ik simultaneously. Both antibody and carbachol could significantly reduce the isoprenaline-stimulated ICa but not the isoprenaline-stimulated Ik. The antibody- or carbachol-induced outward K+ current and the depressant effects of antibody and carbachol on isoprenaline-stimulated ICa were partially antagonized by atropine. These results suggest that the anti-M2 muscarinic receptor antibodies display a stimulatory activity similar to muscarinic receptor agonist on the receptor-mediated electrophysiological events.

FliN is a major structural protein of the C-ring in the Salmonella typhimurium flagellar basal body

The Salmonella typhimurium FliN protein has been proposed to form a mutually interacting complex with FliG and FliM, the switch complex, that is required for flagellar morphogenesis and function. We have used affinity chromatography for purification of extended flagellar basal bodies sufficient for quantitative analysis of their protein composition. The belled, extended structure is predominantly comprised of the switch complex proteins; with FliN present in the most copies (111 +/- 13). This explains why single, missense fliN, fliG or fliM mutations, found in many non-motile strains, can alter the belled morphology. Cell lysates from these strains contained the wild-type complement of FliG, FliM and FliN; but the basal bodies lacked the outer, cytoplasmic(C)-ring of the bell and were separated by sedimentation from FliM and FliN. The amount of FliG present in basal bodies from wild-type and one such mutant, FliN100LP, was comparable. These data show that: (1) the mutations define a FliG and FliMFliN multiple contact interface important for motility. (2) FliG is responsible for the increased size of the membrane-embedded MS-ring complex of belled relative to acid-treated basal bodies. (3) FliN, together with FliM, account for most of the C-ring. As a major component of the C-ring, FliN is distinct from the other proteins implicated in axial flagellar protein export. Inner, cytoplasmic rod basal substructure, seen by negative-stain and quick-freeze replica electron microscopy, may gate such export. Lack of connectivity between the cytoplasmic rod and ring substructures places contacts between FliG and FliMFliN at the periphery of the basal body, proximal to the flagellar intramembrane ring particles. This topology is consistent with models where torque results from interaction of circumferential arrays of the switch complex proteins with the ring particles.

Transcription of dopamine D1A receptor mRNAs in rat heart

The existence of dopamine receptor subtypes in the heart has been suggested by pharmacological and biochemical techniques. So far, however, very little data is available as to the transcription of dopamine D1 subtype receptor genes in the heart. Therefore, in this study we employed reverse transcription-polymerase chain reaction (RT-PCR), which is a sensitive and highly specific method for identifying a low abundance mRNA in tissues, to determine if the D1A receptor gene was transcripted in the adult rat heart. Total RNA was isolated from the whole heart by the guanidium thiocyanate-CsCl method. Primers were based on the sequence of rat D1A cDNA cloned from the brain and corresponded to the third cytoplasmic loop of the receptor. A predicted size product (247bp) was evident from heart RNA. PCR performed in the absence of reverse transcriptase did not result in an amplification of the predicted product, indicating that these products were from cDNA and not from genomic DNA. The results demonstrate the existence of D1A receptor mRNA in the rat heart and that the D1A receptor in the heart are possibly identical to that from the brain. Since in this study the whole heart RNA was used, we cannot ascertain whether the mRNA comes from cardiac myocyte per se or from intermuscular coronary arterioles or from both.

Construction of an insecticidal baculovirus expressing insect-specific neurotoxin AaIT

Considering the factors which affect gene transcription, translation and the stability of mRNA, without changing the amino acid composition of the encoded polypeptide, AaIT gene encoding insect-specific neurotoxin was designed and synthesized according to bias in codon choice, overall G+C content and G+C content of bases at the third position in codons of polyhedrin genes of baculovirus and of plant genes as well. AaIT gene was fused behind a synthetic gp67 signal sequence and then recombined into the genome of Trichoplusia ni nuclear polyhedrosis virus (TnNPV) by transfer vector pSXIV VI+X3. The recombinant virus TnNPV-AaIT (occ+-gal-) was screened. The results of Southern blotting and SDS-PAGE demonstrated that AaIT gene had integrated into the genome of virus and expressed. Bioassays on the 3rd-instar Trichoplusia ni larvae showed that recombinant viruses TnNPV-AaIT could shorten the time of killing insect and improve the efficacy of killing agronomically important insects.

Expression of proliferating cell nuclear antigen in premalignant lesions of the larynx

PURPOSE

This study was performed to 1) evaluate the proliferative activity in premalignancies of the larynx by immunostaining for proliferating cell nuclear antigen (PCNA), 2) to examine the relationship between PCNA expression and histological diagnosis and 3) to evaluate clinical values of PCNA immunostaining.

MATERIALS AND METHODS

The percentage of PCNA-positive nuclei (PCNA index) and their highest location (PCNA grade) were evaluated in 44 specimens of premalignant lesions, 7 premalignant lesions near carcinomas, 9 normal epithelium, and 12 early invasive carcinomas of the larynx. Follow-up was conducted.

RESULTS

The mean of PCNA indices in premalignancies was significantly higher than in normal epithelium but lower than in early invasive carcinomas. PCNA index had no apparent correlation with the histological diagnosis, but in the same case, the higher degree of dysplasia showed higher PCNA index. PCNA grade showed significant correlation with the histological diagnosis. Cases with higher PCNA expression showed higher percentages of recurrence and cancerization. Premalignant lesions near carcinomas presented significantly high PCNA expression.

CONCLUSIONS

The proliferative activity in premalignancies of the larynx is higher than in normal epithelium and lower than in carcinomas. It differs from case to case, but in the same case the higher degree of dysplasia possesses higher proliferative activity. Dysplasia is associated with abnormal proliferation pattern. Special attention should be paid to those with abnormal proliferation patterns as well as high proliferative activity. PCNA immunostaining is of some referential value in predicting clinical outcome and guiding to make an early diagnosis of malignancy.

Insect-resistant tobacco plants expressing insect-specific neurotoxin AaIT

The recombinant plant expression vector pNGY-2 with designed and synthesized AaIT gene had been constructed. The AaIT gene was fused behind the sequence of TMV and inserted into expression vector under the control of two linked 35s promoters. The recombinant plasmid pNGY-2 was transferred into tobacco NC89 by agrobacterium-mediated transfer system. The GUS activity analysis and Southern blotting of regenerated plants indicated that AaIT gene had been integrated into tobacco genome. Insect bioassays showed that some transgenic plants had notable insect-resistant activity.

A study of the demographic characteristics of domestic tourists

"A sample survey was conducted [in China]: more than 6,000 questionnaires were submitted and retrieved from domestic tourists in Shanghai, Xi'ian, Huangshan, and Huashan in order to provide data for demographic analysis of the special fluid population of tourists. The paper looks at the relationship between tourists' gender, age, income, occupation, education, and family structure, as well as their tourist activity, selection of destinations, shopping, and other tourist behaviors."

FliG and FliM distribution in the Salmonella typhimurium cell and flagellar basal bodies

Salmonella typhimurium FliG and FliM are two of three proteins known to be necessary for flagellar morphogenesis as well as energization and switching of flagellar rotation. We have determined FliG and FliM levels in cellular fractions and in extended flagellar basal bodies, using antibodies raised against the purified proteins. Both proteins were found predominantly in the detergent-solubilized particulate fraction containing flagellar structures. Basal flagellar fragments could be separated from partially constructed basal bodies by gel filtration chromatography. FliG and FliM were present in an approximately equimolar ration in all gel-filtered fractions. FliG and FliM copy numbers, estimated relative to that of the hook protein from the early fractions containing long, basal, flagellar fragments, were (means +/- standard errors) 41 +/- 10 and 37 +/- 13 per flagellum, respectively. Extended structures were present in the earliest identifiable basal bodies. Immunoelectron microscopy and immunoblot gel analysis suggested that the FliG and, to a less certain degree, the FliM contents of these structures were the same as those for the complete basal bodies. These facts are consistent with the postulate that FliG and FliM affect flagellar morphogenesis as part of the extended basal structure, formation of which is necessary for assembly of more-distal components of the flagellum. The determined stoichiometries will provide important constraints to modelling energization and switching of flagellar rotation.

Apoptosis and c-jun induction by cisplatin in a human melanoma cell line and a drug-resistant daughter cell line

Cisplatin resistance was developed in the human melanoma cell line RPMI8322 by repeated short-term exposures to cisplatin. The most resistant daughter cell line, RPMI8322/CDDP-300, was 4-fold resistant to cisplatin, and partially cross-resistant to carboplatin, melphalan and UV, but not to BCNU. RPMI8322/CDDP-300 cells showed less apoptosis after cisplatin than the parental cells. The cisplatin resistance was not paralleled by a similar reduction in cellular cisplatin accumulation or DNA cross-links in RPMI8322/CDDP-300 cells, and these cells exhibited no increase in cellular glutathione or in mRNA encoding the DNA excision repair protein ERCC1 and XPB. Induction of c-jun mRNA by cisplatin was considerably lower in RPMI8322/CDDP-300 cells than in RPMI8322 cells, consistent with the possibility that c-jun induction may be involved in a pathway that triggers apoptosis after exposure to DNA damaging agents. However, c-jun induction is not necessary for apoptosis, since cisplatin also induced apoptosis in A14 rat embryo fibroblasts, cells in which the c-jun gene is deleted.

Structural effects of mutations in Salmonella typhimurium flagellar switch complex

Mutations in Salmonella typhimurium fliG, fliM and fliN give rise either to non-flagellate, non-motile or non-chemotactic mutant bacteria. The FliG, FliM and FliN proteins form part of recently characterized extended flagellar basal structures, and have been postulated to form a mutually interacting structural complex. We have examined basal body preparations from non-motile or non-chemotactic fliG, fliM and fliN mutant strains by electron microscopy and immunoblot gel analysis. Most flagellar preparations isolated from the non-motile mutants lacked FliM, but contained FliG. The basal bodies lacked the belled morphology characteristic of the wild-type structures, but had protrusions which could be labelled with anti-FliG. Non-motile mutant preparations severely depleted of FliG but containing FliM were also obtained. These preparations contained extended, belled flagellar structures that were labelled with anti-FliM. Thus, FliM is part of the shell of the extended structures responsible for the belled morphology, while FliG may be part of the inner substructure. The extended basal structures from a FliG temperature-sensitive mutant strain rapidly lost FliM, as well as FliG, upon a shift to a non-permissive temperature, implying interaction between the FliG- and FliM-containing substructures. In dramatic contrast to non-motile mutants, extended basal structures isolated from non-chemotactic mutants were indistinguishable from wild-type structures. This difference may reflect the energetics of the different protein-protein interactions operative during torque generation and the switching of rotation sense.

[Effects of Chinese ginseng root and stem-leaf saponins on learning, memory and biogenic monoamines of brain in rats]

The present investigation has shown that Ginseng root saponins (ig, 50mg/kg x 7d) facilitate the learning and memory of normal male Wistar rats, while the effect of Ginseng stem-leaf saponins (ig, 50mg/kg x 7d) on antielectrconvulsive shock-induced impairment of memory consolidation in rats is more intensive than that of root saponins. Both Ginseng root and stem-leaf saponins can significantly raise the levels of biogenic monoamines in normal rat's brain.

Conserved machinery of the bacterial flagellar motor

Novel periplasmic and cytoplasmic structural modules of the bases of bacterial flagella have been observed in situ and isolated using new biochemical protocols. Flagellar rotation may depend upon interactions of these modules with the intramembrane particle rings, a ubiquitous feature of flagellar bases necessary for torque generation. The outer membrane-associated basal disk of the Wolinella succinogenes polar flagellum has architecture well suited for interaction with the ring particles. However, antibody against the main W. succinogenes basal disk protein did not cross-react with flagella-enriched fractions from Salmonella typhimurium and Bacillus firmus; nor have such structures been observed in these species thus far. Antibodies against two S. typhimurium proteins, FliG and FliM, known to be involved in motor function and part of the cytoplasmic module in this species cross-reacted with flagella-enriched fractions from both W. succinogenes and B. firmus. In addition, flagellar cytoplasmic structure could be isolated from B. firmus. The basal disk may anchor the flagellar motor to the cell wall in some polar bacteria, but this does not seem to be a unique strategy. In contrast, the data indicate that the cytoplasmic module is conserved.

The purification and characterization of a human dual-specific protein tyrosine phosphatase

An expression and purification method was developed to obtain the recombinant human dual-specific protein tyrosine phosphatase (PTPase) VHR in quantities suitable for both kinetic studies and crystallization. Physical characterization of the homogeneous recombinant protein verified the mass to be 20,500 +/- 100 by matrix-assisted laser desorption mass spectrometry, confirmed the anticipated NH2-terminal amino acid sequence and demonstrated that the protein exists as a monomer. Conditions were developed to obtain crystals which were suitable for x-ray structure determination. Using synthetic diphosphorylated peptides corresponding to MAP177-189 (mitogen-activated protein) kinase (DHTG-FLpTEpYVATR), an assay was devised which permitted the determination of the rate constants for dephosphorylation of the diphosphorylated peptide on threonine and tyrosine residues. The diphosphorylated peptides are preferred over the singly phosphorylated on tyrosine by 3-8-fold. The apparent second-order rate constant kcat/Km for dephosphorylation of phosphotyrosine on DHTGFLpTEpYVATR was 32,000 M-1 S-1 while dephosphorylation of phosphothreonine was 14 M-1 S-1 (pH 6). The reaction of DHTGFLpTEpYVATR with VHR is ordered, with rapid dephosphorylation on tyrosine occurring first followed by slow dephosphorylation on threonine. Similar results were obtained with F(NLe)(N-Le)pTPpYVVTR, a peptide corresponding to a MAP kinase-like protein (JNK1(180-189)) which is involved in the stress response signaling pathway.

Highly insect-resistant transgenic tobacco plants containing both B.t. and CpTI genes

The cowpea trypsin inhibitor (CpTI) gene was synthesized according to its cDNA sequence using DNA synthesizer and confirmed by DNA sequencing. The CpTI gene and modified Bacillus thuringiensis (B.t.) delta-endotoxin gene were cotransformed to tobacco explants mediated by Agrobacterium tumefaciens. The integrations of B.t and CpTI genes were confirmed by PCR and Southern hybridization. Three kinds of transgenic plants were obtained: (1) containing CpTI gene, (2) containing B.t gene, (3) containing both CpTI and B.t genes. Bioassays showed that all these transgenic plants were toxic to the larvae of Heliothis armigera and that the tobacco plants containing both genes had enhanced toxicity to larvae by comparison with plants containing only CpTI or B.t gene.

Oral toxicity of boric acid and other boron compounds to immature cat fleas (Siphonaptera: Pulicidae)

Oral toxicity was characterized in first-instar cat fleas, Ctenocephalides felis felis (Bouché), feeding on dried blood treated with boric acid. LC50 values ranged from 2.11% after 24 h to 0.21% after 7 d. In carpet tests with five different boron compounds and a number of different formulations, significant mortality for first instars was observed in all cases. In similar tests with prepupae and cocoons, there was no significant effect on mortality. The importance of these results is discussed in light of current application procedures for boron compounds, and suggestions are made for future research.

[Direct determination of tin in water by oscillopolarography]

Sn(IV) has a sensitive polarographic wave in the system of H2SO4-KI-VitC-V (IV). We examined the factors influencing the polarographic wave and found that the concentration of sulfuric acid and temperature were critical factors for the determination. The sensitivity of the method was increased nearly 50-fold by decreasing the concentration of sulfuric acid from 0.8 mol/L to 0.1 mol/L. The coefficient of variation (CV) percentages of the method were less than 5% and 8% for 6-7 determinations of Sn (IV) standard and sample respectively. The recovery ranged from 97.3% to 101%. The proposed method is suitable for direct determination of trace Sn (IV) in most natural water samples.

Products, genetic linkage and limb patterning activity of a murine hedgehog gene

The hedgehog (hh) segmentation gene of Drosophila melanogaster encodes a secreted signaling protein that functions in the patterning of larval and adult structures. Using low stringency hybridization and degenerate PCR primers, we have isolated complete or partial hh-like sequences from a range of invertebrate species including other insects, leech and sea urchin. We have also isolated three mouse and two human DNA fragments encoding distinct hh-like sequences. Our studies have focused upon Hhg-1, a mouse gene encoding a protein with 46% amino acid identity to hh. The Hhg-1 gene, which corresponds to the previously described vhh-1 or sonic class, is expressed in the notochord, ventral neural tube, lung bud, hindgut and posterior margin of the limb bud in developing mouse embryos. By segregation analysis the Hhg-1 gene has been localized to a region in proximal chromosome 5, where two mutations affecting mouse limb development previously have been mapped. In Drosophila embryos, ubiquitous expression of the Hhg-1 gene yields effects upon gene expression and cuticle pattern similar to those observed for the Drosophila hh gene. We also find that cultured quail cells transfected with a Hhg-1 expression construct can induce digit duplications when grafted to anterior or mid-distal but not posterior borders within the developing chick limb; more proximal limb element duplications are induced exclusively by mid-distal grafts. Both in transgenic Drosophila embryos and in transfected quail cells, the Hhg-1 protein product is cleaved to yield two stable fragments from a single larger precursor. The significance of Hhg-1 genetic linkage, patterning activity and proteolytic processing in Drosophila and chick embryos is discussed.

The prokaryotic thermophilic TF1-ATPase is functionally compatible with the eukaryotic CFo-part of the chloroplast ATP-synthase

The ATP synthase from chloroplasts, CFo.F1, was reconstituted into liposomes, from which most of CF1 was removed by a short treatment with guanidinium chloride. ATP-dependent proton uptake was restored with these CFo-liposomes even better by the addition of the bacterial TF1-than of the related CF1-part. This proton uptake was prevented by tentoxin, a specific inhibitor of the CF1-ATPase, in these CFo.F1-liposomes, but not in the hybrid CFo.TF1-liposomes. Venturicidin, a specific inhibitor of proton flow through CFo, was able to block it in both the hybrid CFo.TF1-liposomes and reconstituted CFo.F1-liposomes. These results indicate that the bacterial TF1-part binds to the eukaryotic CFo-part of four subunits forming a functional CFo.TF1-ATPase.