Application and field validation of a continuous nonmethane organic carbon analyzer

Nonmethane organic carbon (NMOC) is a measure of total organic carbon except for that from CH4. We recently reported the development of online instrumentation for continuous NMOC monitoring. This instrument, referred to as C-NMOC, uses a microsorbent trap in combination with a gas-sampling valve as the sampling interface. A conventional oxidation/reduction NMOC detector is used for quantitation. In addition to being an online concentrator and an injector, the microtrap serves as a separator that isolates NMOC from H2O, CO, CO2, CH4, and other background gases. Therefore, the C-NMOC is able to handle high concentrations of background gases commonly found in stack emissions and has detection limits in the ppb levels. This paper reports the results of field validation and testing of a C-NMOC analyzer at a coatings facility in the eastern United States. The instrument was able to monitor the process transients in real time, based on which corrective actions could be taken. It demonstrated good accuracy, high precision, and long-term stability.

Iridoid glycosides from the leaves of Morinda citrifolia

A new iridoid glucoside (1), named citrifolinoside A, was isolated from the leaves of Morinda citrifolia along with the known iridoids asperuloside and asperulosidic acid. The structure of 1 was established by interpretation and full assignments of NMR spectroscopic data.

Formation and identification of 4'-O-methyl-(-)-epigallocatechin in humans

The possible beneficial effects of tea consumption have attracted a great deal of attention. Many of the biological effects have been attributed to tea catechins, but the metabolic fate of these compounds is not clear. In the present study, a major metabolite observed in human blood and urine samples after green tea administration was identified as a O-methylated derivative of (-)-epigallocatechin (EGC) by comparison with products from chemical and enzymatic O-methylation of EGC. The structure of this metabolite was elucidated as 4'-O-methyl-(-)-epigallocatechin (4'-O-MeEGC) by (1)H and (13)C NMR and heteronuclear multiple bond connectivity experiment. The human plasma level of 4'-O-MeEGC reached its peak value within the first 2 h following tea ingestion. Its maximum concentration was 4 to 6 times higher than that of EGC. The half-lives of EGC and 4'-O-MeEGC in the blood were 1.02 +/- 0.07 and 4.39 +/- 1.14 h, respectively. The amount of 4'-O-MeEGC excreted in urine was about 3 times higher than that of EGC, and 88% of 4'-O-MeEGC was excreted in urine within 8 h. The present structural information and concentration-time profile of this metabolite provide the basis for understanding the biotransformation of EGC and for future elucidation of its biological activities.

A novel MaxiK splice variant exhibits dominant-negative properties for surface expression

We identified a novel MaxiK alpha subunit splice variant (SV1) from rat myometrium that is also present in brain. SV1 has a 33-amino acid insert in the S1 transmembrane domain that does not alter S1 overall hydrophobicity, but makes the S0-S1 linker longer. SV1 was transfected in HEK293T cells and studied using immunocytochemistry and electrophysiology. In non-permeabilized cells, N-terminal c-Myc- or C-terminal green fluorescent protein-tagged SV1 displayed no surface labeling or currents. The lack of SV1 functional expression was due to endoplasmic reticulum (ER) retention as determined by colabeling experiments with a specific ER marker. To explore the functional role of SV1, we coexpressed SV1 with the alpha (human SLO) and beta1 (KCNMB1) subunits of the MaxiK channel. Coexpression of SV1 inhibited surface expression of alpha and beta1 subunits approximately 80% by trapping them in the ER. This inhibition seems to be specific for MaxiK channel subunits since SV1 was unable to prevent surface expression of the Kv4.3 channel or to interact with green fluorescent protein. These results indicate a dominant-negative role of SV1 in MaxiK channel expression. Moreover, they reveal down-regulation by splice variants as a new mechanism that may contribute to the diverse levels of MaxiK channel expression in non-excitable and excitable cells.

Hepatitis C virus core protein enhances FADD-mediated apoptosis and suppresses TRADD signaling of tumor necrosis factor receptor

Hepatitis C virus (HCV) core protein has been shown to interact with the death domain (DD) of tumor necrosis factor receptor-1 (TNFR1). In this study, we further examined the interaction of the core protein with the signaling molecules of TNFR1, including FADD, TRADD, and TRAF2, in a human embryonic kidney cell line, HEK-293, that overexpresses the HCV core protein. This core protein-expressing cell line exhibited enhanced sensitivity to TNF-induced apoptosis. By in vitro binding and in vivo coimmunoprecipitation assays, we showed that the HCV core protein interacted with the DD of FADD and enhanced apoptosis induced by FADD overexpression. This enhancement could be blocked by a dominant-negative mutant of FADD. In contrast, the core protein did not directly interact with the DD of TRADD, but could disrupt the binding of TRADD to TNFR1. TRAF2 recruitment to the TNFR1 signaling complex was also disrupted by the core protein. Correspondingly, TRAF2-dependent activation of the protein kinase JNK was suppressed in the core protein-expressing cells. However, NF kappa B activation by TNF was not significantly altered by the HCV core protein, suggesting the existence of TRAF2-independent pathways for NF kappa B activation. These results combined indicate that the HCV core protein sensitizes cells to TNF-induced apoptosis primarily by facilitating FADD recruitment to TNFR1. The inhibition of JNK activation by the HCV core protein may also contribute to the increased propensity of cells for apoptosis. These results, in comparison with other published studies, suggest that the effects of the HCV core protein and their underlying mechanisms vary significantly among cells of different origins.

[Microbial degradation of polychlorinated dibenzo-p-dioxins]

PCDDs-degrading bacterial strains were isolated from soil and oxic-sediments polluted by PCDDs. One of them was identified as Pseudomonas sp. EE41. They are capable of growing on and degrade mono- and di-chlorinated dibenzo-p-dioxins as a sole carbon source. The biodegradability of TrCDD and TCDD can be enhanced through primary nutrient of co-metabolism of o-CDB, thus, 1,2,3-TrCDD and 2,3,7,8-TCDD were degraded by 33% (at the concentration of 1.2 mg/L, within 3 weeks) and 37.8% (at the concentration of 0.1 mg/L, within 3 weeks) respectively. Most highly chlorinated dibenzo-p-dioxins (P-CDD, H6-, H7-CDD and OCDD) tested in this study were accumulated in bacterial cells, but could not be degraded.

Cycloartane triterpene saponins from the roots of Cimicifuga foetida

The structures of two new cycloartane-type saponin constituents of the roots of Cimicifuga foetida were established by the interpretation of spectroscopic data as 2'-O-acetylactein (1) and 2'-O-acetyl-27-deoxyactein (2), respectively. Also isolated were the known compounds actein, 27-deoxyactein, cimicifugoside H-1, and 15alpha-hydroxycimicidol 3-O-beta-D-xyloside.

Ecdysteroids of quinoa seeds (Chenopodium quinoa Willd.)

Quinoa (Chenopodium quinoa) is a hardy and nutritious Latin American pseudo-cereal. Studies on the seeds led to the isolation of five ecdysteroids using column chromatography. Their structures were determined as ecdysterone, makisterone A, 24-epi-makisterone A, 24(28)-dehydromakisterone A, and 20,26-dihydroxyecdysone by spectroscopic methods. This study demonstrates that quinoa seeds are a source of ecdysteroids, which were reported to be molting hormones in insects.

[The combination of cyclosporin A and androgen in the treatment of chronic aplastic anemia]

OBJECTIVE

To explore the therapeutic effectiveness of combination of cyclosporin A (CsA) and androgen in the treatment of chronic aplastic anemia (CAA).

METHOD

Androgen alone or combined with CsA for the treatment of CAA was compared by a randomized controlled clinical trial.

RESULT

The efficacy of androgen combined with CsA (87.9%) was higher than that of androgen alone (57.1%). Therapeutic effectiveness of the combination treatment between the patients with positive and negative peripheral blood mononuclear cells (PBMNCs) inhibiting normal colony formation unit-granulocyte and macrophage (CFU-GM) test showed a significant difference (P < 0.005).

CONCLUSION

Androgen combined with CsA had a much better efficacy than that of androgen alone in the treatment of CAA. The patients' PBMNCs inhibiting normal CFU-GM growth test can be used as an index of the treatment outcome. The side effects of the combination therapy are low and tolerable.

[Determination of 10 elements in the 12 kinds of Chinese traditional medicines by AAS]

The 10 kinds of inorganic elements were determined in 12 kinds of Chinese traditional medicines. The relation showed that there were numerous inorganic elements in the traditional chinese medicines. The relation between these inorganic elements and the efficacies of these medicines was studied and the efficacies of these Chinese traditional medicines were discussed. The efficacies of these traditional medicines were greatly influenced by the content of inorganic elements. To guarantee the efficacies of these traditional medicines, the reasonable control lines concerned with the content of inorganic elements shall be established and the lines will be discussed in the future.

Bioactive constituents from gum guggul (Commiphora wightii)

Bioactivity-directed fractionation and purification afforded cytotoxic components of Commiphora wightii. The exudates of C. wightii were extracted with EtOAc and the extract was subjected to repeated column chromatography. A fraction showing cytotoxic activity was characterized as a mixture of two ferulates with an unusual skeleton by spectral and chemical methods, including by NMR, GC-MS and chemical derivatization. This fraction also showed moderate scavenging effect against 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals.

Enhancement of biodegradability of polychlorinated dibenzo-p-dioxins

Enhancement of biodegradability of polychlorinated dibenzo-p-dioxins (PCDDs) was studied with new isolated bacterial strains from soil and oxic-sediments contaminated by PCDDs. The results indicated that mono- and di-chlorinated dibenzo-p-dioxins could be utilized as a sole carbon source and degraded by isolated bacterial strains, but tri-chlorinated dibenzo-p-dioxin (TrCDD) was hardly degraded. The biodegradability of TrCDD and tetra-chlorinated dibenzo-p-dioxin (TCDD) by the strain Pseudomonas sp. EE41, a new isolated one, could be enhanced through primary nutrient of co-metabolism of o-dichlorobenzene (o-DCB). In this case, TrCDD (1.2mg/l for 3 weeks) was degraded by 33.1% and the degradation rate enhanced more than 2 fold; also TCDD (0.1 mg/l for 3 weeks) biodegraded by 37.8%. Most highly chlorinated, Penta-, Hexa-, Hepta-, and Octa-chlorinated, dibenzo-p-dioxins (P-CDD, H6, H7-CDD and OCDD) tested in this study could not be degraded while accumulated in bacterial cells.

[The multimedia molecular biological image processing system]

With the use of computer image processing technology and molecular biological technology, we have developed a new multimedia molecular biological information processing system to detect the characteristic parameter of molecular biological electrophoresis image. The system can determine the macromolecules densities and molecular weight of the DNA amplified fragment or restriction endonuclease hydrolytic fragment protein and other macromolecules. The clinical use and biological application indicate that the system is useful to gene diagnosis and molecular biological researches.

Iterative optimal design of PET experiments for estimating beta-adrenergic receptor concentration

To estimate in vivo myocardial beta-adrenergic receptor concentration with sufficient precision and to reduce the experimental complexities in positron emission tomography (PET), an iterative optimal design method is applied. An initial three-injection protocol, utilising [F-18]-labelled (R)- and (S)-fluorocarazolol and unlabelled (S)-fluorocarazolol, is optimised for ligand dosages and administration times to maximise the precision of all model parameters using the D-optimal criterion. Using this experimental protocol, PET data are collected in porcine studies, and model parameters are estimated. All model parameters are identified with satisfactory precision. The in vivo myocardial beta-receptor concentration is 7.5+/-0.6 pmol x ml(-1), which corresponds to the in vitro result of 10.1+/-1.3 pmol x ml(-1). With more accurate parameter values, a simplified two-injection protocol is optimally designed, utilising only radiolabelled and unlabelled (S)-fluorocarazolol, based on a new criterion to maximise the precision of the beta-receptor concentration. This revised optimum design predicts that the in vivo beta-receptor concentration can be estimated with good precision but reduced experiment complexity.

RNA-Dependent replication and transcription of hepatitis delta virus RNA involve distinct cellular RNA polymerases

Cellular DNA-dependent RNA polymerase II (pol II) has been postulated to carry out RNA-dependent RNA replication and transcription of hepatitis delta virus (HDV) RNA, generating a full-length (1.7-kb) RNA genome and a subgenomic-length (0.8-kb) mRNA. However, the supporting evidence for this hypothesis was ambiguous because the previous experiments relied on DNA-templated transcription to initiate HDV RNA synthesis. Furthermore, there is no evidence that the same cellular enzyme is involved in the synthesis of both RNA species. In this study, we used a novel HDV RNA-based transfection approach, devoid of any artificial HDV cDNA intermediates, to determine the enzymatic and metabolic requirements for the synthesis of these two RNA species. We showed that HDV subgenomic mRNA transcription was inhibited by a low concentration of alpha-amanitin (<3 microgram/ml) and could be partially restored by an alpha-amanitin-resistant mutant pol II; however, surprisingly, the synthesis of the full-length (1.7-kb) antigenomic RNA was not affected by alpha-amanitin to a concentration higher than 25 microgram/ml. By several other criteria, such as the differing requirement for the de novo-synthesized hepatitis delta antigen and temperature dependence, we further showed that the metabolic requirements of subgenomic HDV mRNA synthesis are different from those for the synthesis of genomic-length HDV RNA and cellular pol II transcripts. The synthesis of the two HDV RNA species could also be uncoupled under several different conditions. These findings provide strong evidence that pol II, or proteins derived from pol II transcripts, is involved in mRNA transcription from the HDV RNA template. In contrast, the synthesis of the 1.7-kb HDV antigenomic RNA appears not to be dependent on pol II. These results reveal that there are distinct molecular mechanisms for the synthesis of these two RNA species.

Novel glycosides from noni (Morinda citrifolia)

Three new glycosides were isolated from the fruits of noni (Morinda citrifolia). Their structures were determined to be 6-O-(beta-D-glucopyranosyl)-1-O-octanoyl-beta-D-glucopyranose (1), 6-O-(beta-D-glucopyranosyl)-1-O-hexanoyl-beta-D-glucopyranose (2), and 3-methylbut-3-enyl 6-O-beta-D-glucopyranosyl-beta-D-glucopyranoside (3) using MS and NMR methods.

Identification of oxidation products of (-)-epigallocatechin gallate and (-)-epigallocatechin with H(2)O(2)

(-)-Epigallocatechin gallate (EGCG) and (-)-epigallocatechin (EGC) are two important antioxidants in tea. They also display some antitumor activities, and these activities are believed to be mainly due to their antioxidative effects. However, the specific mechanisms of antioxidant action of tea catechins remain unclear. In this study are isolated and identified two novel reaction products of EGCG and one product of EGC when they were reacted separately with H(2)O(2). These products are formed by the oxidation and decarboxylation of the A ring in the catechin molecule. This study provides unequivocal proof that the A ring of EGCG and EGC may also be an antioxidant site. This study also indicates an additional reaction pathway for the oxidation chemistry of tea catechins.

Isolation and structural elucidation of two new glycosides from sage (Salvia officinalis L.)

Six compounds, 1-O-(2,3, 4-trihydroxy-3-methyl)butyl-6-O-feruloyl-beta-D-glucopyranoside, ethyl beta-D-glucopyranosyl tuberonate, p-hydroxybenzoic acid, (-)-hydroxyjasmonic acid, caffeic acid, and 4-hydroxyacetophenone 4-O-[5-O-(3, 5-dimethoxy-4-hydroxybenzoyl)-beta-D-apiofrunosyl]-(1-->2)-beta-D- glu copyranoside, were isolated from the n-butanol-soluble fraction of sage leaf extracts. Their structures were determined by spectral methods (MS, NMR, and 2D-NMR), and their antioxidant activities were measured. Among them, two new glycosides were elucidated. All of these compounds showed DPPH free radical scavenging activity at the concentration of 30 mM, and caffeic acid was the most active compound.

Isolation and identification of stilbenes in two varieties of Polygonum cuspidatum

The roots of two varieties of Polygonum cuspidatum (Hu Zhang and Mexican Bamboo) were analyzed for resveratrol and analogues. The roots of each variety were dried and ground into a powder. The powdered roots were then extracted with methanol and ethyl acetate. The ethyl acetate fraction of the Mexican Bamboo was then subjected to fractionation and purification using silica gel column chromatography and semipreparative HPLC. In addition to resveratrol (3,5,4'-trihydroxystilbene), three stilbene glucosides were identified by (1)H NMR, (13)C NMR, and MS. The stilbene glucosides were shown to be a piceatannol glucoside (3,5,3', 4'-tetrahydroxystilbene 4'-O-beta-D-glucopyranoside), resveratroloside (3,5,4'-trihydroxystilbene 4'-O-beta-D-glucopyranoside), and piceid (3,5,4'-trihydroxystilbene 3-O-beta-D-glucopyranoside). The levels of the piceatannol glucoside and piceid were twice as high in the Mexican Bamboo as compared to the Hu Zhang.

Cheek cell phospholipids in human infants: a marker of docosahexaenoic and arachidonic acids in the diet, plasma, and red blood cells

BACKGROUND

Assessment of essential fatty acid status requires collection of blood or adipose tissue samples. However, these invasive techniques cannot always be used in studies involving infants, young children, or subjects from whom it is difficult to obtain blood. A body tissue that is easy to access is the buccal mucosa (cheek cells).

OBJECTIVE

The objective was to investigate the degree to which fatty acids of cheek cells reflect the fatty acid content of plasma, red blood cells, and the diet.

DESIGN

Thirty-one infants aged 12 mo were enrolled. Five infants were fed human milk and 26 infants received formulas that provided a wide range of arachidonic acid and docosahexaenoic acid (DHA) intakes. Cheek cells were collected on a small piece of gauze by gently swabbing the inside of the cheek 3 times. Lipids were extracted from the gauze and the phospholipid fatty acid content of the cheek cells was determined.

RESULTS

Cheek cell DHA and arachidonic acid in phospholipids were significantly correlated with DHA and arachidonic acid in plasma [r = 0.61 (P < 0.001) and r = 0.37 (P <0.05), respectively], red blood cells [r = 0.58 (P < 0.001) and r = 0.37 (P < 0.05), respectively], and the diet [r = 0.65 (P < 0.001) and r = 0. 51 (P < 0.01), respectively].

CONCLUSIONS

Given these correlations and the ease and noninvasive nature of this technique, cheek cell fatty acids may serve as a marker of the essential fatty acid content, especially of DHA and arachidonic acid, in plasma, red blood cells, and the diet.

[Cloning of full-length Dnmt3b cDNA and its alternative splicing isoforms in mouse embryo]

OBJECTIVE

To clone the novel full-length cDNA related to mouse embryonic development.

METHODS

Starting from a new expression sequence (clone 2 #) out of a mouse embryonic cDNA library, its full-length cDNA were obtained by rapid amplification of cDNA ends with polyA RNA isolated from mouse 8-9 day embryonic tissue as template, combined with screening of mouse embryonic cDNA library by PCR. Based on the sequences at the two ends of the cDNA, the primers for long range RT-PCR were designed to confirm its factuality.

RESULTS

The cDNA isolated in our hands was one of the alternative splicing isoforms of mouse de novo DNA cytosine 5'-specific methyltransferase gene (Dnmt3b) reported in July, 1998. A new alternative splicing region upstream of its initiate codon was found 5' forwards 152 bp over the Dnmt3b cDNA sequence. Eight alternative splicing isoforms of Dnmt3b from mouse embryonic tissue were cloned (Genbank accession number are AF151969, AF151970, AF151971, AF151972, AF151973, AF151974, AF151975, AF151976 respectively).

CONCLUSIONS

The 4 kb full-length Dnmt3b cDNA was isolated. Dnmt3b may have novel exons at its 5' upstream and present a complex alternative splicing pattern during mouse embryonic development.

Two C21-steroidal glycosides isolated from Cynanchum stauntoi

Studies on the roots of Cynanchum stauntoi led to the isolation of two C21-steroidal glycosides, formally named stauntosides A and B. Their structures were elucidated on the basis of spectroscopic evidence, especially that from analysis of 2D-NMR spectra. They were found to possess an unusual skeleton and were identified as stauntogenin 3-O-alpha-L-diginopyranosyl-(1-4)-beta-L-cymaropyranosyl-(1- 4)-beta-D- digitoxopyranosyl-(1-4)-beta-D-thevetopyranoside and stauntogenin 3-O-alpha-L-cymaropyranosyl-(1-4)-beta-D-digitoxopyranosyl-( 1-4)-beta-D-3- demethyl-2-deoxy-thevetopyranoside.

Hormonal control of protein expression and mRNA levels of the MaxiK channel alpha subunit in myometrium

Large conductance voltage-dependent and Ca(2+)-modulated K(+) channels play a crucial role in myometrium contractility. Western blots and immunocytochemistry of rat uterine sections or isolated cells show that MaxiK channel protein signals drastically decrease towards the end of pregnancy. Consistent with a transcriptional regulation of channel expression, mRNA levels quantified with the ribonuclease protection assay correlated well with MaxiK protein levels. As a control, Na(+)/K(+)-ATPase protein and RNA levels do not significantly change at different stages of pregnancy. The low numbers of MaxiK channels at the end of pregnancy may facilitate uterine contraction needed for parturition.

Synthesis and stereochemical assignment of exo- and endo-7-methyl-7-azabicyclo[2.2.1]heptan-2-ol

[formula: see text] The syntheses of both exo and endo stereoisomers of 7-methyl-7-azabicyclo[2.2.1]heptan-2-ol were achieved in straightforward fashion. Alternatively, the intramolecular cyclization of syn-4-N-methylaminocyclohexane 1,2-epoxide was found to give exo-7-methyl-7-azabicyclo-[2.2.1]heptan-2-ol as the sole product. The stereochemistry of the exo isomer was unequivocally confirmed by X-ray crystallography.

Application of capillary nongel sieving electrophoresis for gene analysis

Capillary electrophoresis (CE) has proved to be a strong tool for DNA analysis and has found abundant applications in the fields of restriction fragment sizing, mutation screening, polymerase chain reaction (PCR) product characterizing and forensic identifying. CE may be the main alternative to slab gel electrophoresis. Capillary nongel electrophoresis is the most favorable mode when aiming for this purpose because of its advantages of long lifetime, easy operation, good reproducibility, and low expense. In this paper, a new kind of sieving matrix, with mannitol as the additive for capillary electrophoresis, as well as related methods and their application for gene analysis were reported. Nine DNA fragments amplified by multiplex PCR from a normal dystrophin gene were well separated by this system. Three different deletions were found in Duchenne muscular dystrophy (DMD) patients. Three to four copies of the sex-determination region of the Y chromosome (SRY) gene, as well as the phenylalanine hydroxylase (PAH) gene, could be detected in mixed samples. The frequencies of short tandem repeats (STR) in PAH genes was analyzed in 61 normal Chinese individuals and 6 phenylketonuria families. One case of prenatal gene diagnosis was performed. By using this matrix, CE coupled with reverse transcription PCR (RT-PCR), the analysis of the alternative splicing expression pattern of the fragile X mental retardation 1 (FMR1) gene in adult lung tissue was achieved.