High-throughput identification, database storage and analysis of SNPs in EST sequences

Single nucleotide polymorphisms (SNPs) are the most frequent form of DNA variation and disease-causing mutations in many genes. Due to their abundance and slow mutation rate within generations, they are thought to be the next generation of genetic markers that can be used in a myriad of important biological, genetic, pharmacological, and medical applications. There are several strategies both experimental, and in-silico for SNP discovery and mapping. Experimental SNP discovery consists of a number of labourious steps that make this process complex and expensive. In-silico discovery has been proposed as an alternative discovery method that makes use and takes advantage of large data sets with potential SNP information that have been generated with other purposes and have not been used as a SNP information source yet. However, in order to successfully apply the in-silico method to large data sets, the following challenges need to be addressed: First it is necessary to build an integrated SNP pipeline that handles data processing steps smoothly from the beginning (collecting sequence information) to end (SNPs in the database). Also, SNP detection tool parameters have to be optimized to satisfy specific goals of the project. Finally, SNP data could not be fully used until the in-silico method is validated experimentally. In this paper we present a design and implementation of an in-silico SNP detection software pipeline that exploits the existence of large EST (expressed sequence tag) data sets and effectively addresses the above challenges. First, the pipeline allows for smooth data transition between its different components by implementing data interfaces that translate the data formats of the different tools in the different stages. Second, we optimized PolyBayes parameters for SNP detection in maize EST. Finally, we implemented a user interface that along with the database structure created allows the scientist to perform preliminary analysis of the data and to perform basic statistics on the SNP data prior to experimental validation. The pipeline works with two different types of sequence assemblers (PHRAP (http://www.phrap.org/) and CAT from DoubleTwist (http://www.doubletwist.com/). It uses a Bayesian engine for SNP detection (PolyBayes), selects relevant polymorphism information which is then uploaded into a database. We detected 2439 SNPs and 822 insertion deletions (INDELs) with a PolyBayes probability higher than 0.99 on the public set of 68,000 maize ESTs. The user interface allowed us analyzing the polymorphism information right after discovery in several ways that allowed us to gain insight into the distribution and significance of the newly acquired data.

[Determination of flavonoids and quality evaluation of Chinese traditional drug "puhuang"]

This paper deals with the determination of flavonoids and quality evaluation of Chinese Typha. Four species, viz. Typha angustata, T. angustifolia, T. davidiana and T. latifolia and eight commercial samples of Chinese traditional drug "Puhuang" were collected. Five flavonoids in pollen, filaments, female flowers and leaves were determined by HPLC using mu-Bondapak C18 column, water--isopropanol--tetrahydrofuran = 83.5:14:2.5, as mokile phase and detected at 287 nm). The qualities of different Typha species and commercial "Puhuang" samples have been compared, and the criteria for their quality control were also discussed.

Palladium-catalyzed coupling of two alkynes and an alkenyl iodide: formation of pentasubstituted fulvenes

[reaction: see text]. Disubstituted alkynes reacted with alkenyl iodide in the presence of a catalytic amount of Pd(OAc)2 and Ag2CO3 to give pentasubstituted fulvene derivatives in excellent yields. Other Ag salts such as AgNO3, AgBF4, and AgOTf are not effective, whereas a combination of AgNO3 and K2CO3 has a remarkable effect on the formation of fulvene.

Guide RNAs of the recently isolated LEM125 strain of Leishmania tarentolae: an unexpected complexity

Guide RNAs (gRNAs) are encoded both in the maxicircle and minicircle components of the mitochondrial DNA of trypanosomatid protozoa. These RNAs mediate the precise insertion and deletion of U residues in transcripts of the maxicircle DNA. We showed previously that the old UC laboratory strain of Leishmania tarentolae apparently lost more than 40 minicircle-encoded gRNAs that are present in the recently isolated LEM125 strain (Thiemann et al., EMBO J, 1994, 13:5689-5700]. We have further analyzed the population of minicircle-encoded gRNAs in the LEM125 strain. Sau3AI and MspI minicircle libraries were constructed and screened for novel gRNAs by negative colony hybridization. This search yielded 20 minicircles encoding new gRNAs that covered most of the remaining gaps in the editing cascades of the ND8, ND9, G4, and G5 genes, and in addition, more than 30 minicircles containing either unassigned or undetectable gRNA genes. We also completely sequenced 34 of the 45 minicircle sequence classes encoding previously identified gRNAs. A total of 19 pairs of redundant gRNAs, which are gRNAs of different sequences covering the same editing blocks, were identified. The gRNAs in each redundant pair generally had different relative abundances and different extents of mismatches with edited sequences. Alignments of the minicircles encoding redundant gRNAs yielded 59 to 93% matching nucleotides, suggesting an origin from duplication of ancestral minicircles and subsequent genetic drift. We propose a functional explanation for the existence of redundant gRNAs in this strain.

Inhibition of v-Abl transformation in 3T3 cells overexpressing different forms of the Abelson interactor protein Abi-1

The abi-1 gene encodes a protein that binds and is phosphorylated by the Abelson protein tyrosine kinase. Constructs expressing a full-length abi-1 cDNA, and a smaller cDNA arising from an alternatively spliced form, were generated and tested for their effect on transformation of NIH3T3 cells by the Abelson murine leukemia virus. Overexpression of both forms of the protein strongly inhibited transformation by the wild-type P160 strain of the virus, but not by the non-interacting mutant P90A strain. The inhibition required the SH3 domain of Abi-1, suggesting that a direct interaction was required for the effect. Rare breakthrough P160 transformants of the Abi-1 overexpressing lines were found to have downregulated Abi-1 protein levels by a post-transcriptional mechanism.

[A study on polymorphism of salivary esterase in personal identification]

OBJECTIVE

To research the value of polymorphism of salivary esterase(Set) in paternity and personal identification.

METHODS

Phenotype and genotype of human salivary esterase were detected in 114 liquid saliva samples from the Chinese population by disc electrophoresis and fast blue RR staining assay.

RESULTS

The frequency of Set type was F 22.81%, FS 50.88%, S2 6.31%. The estimated gene frequency of SetF was 0.4825 and SetS was 0.5175. The PE was 0.1875 and the DP was 0.6199.

CONCLUSION

Polymorphism of salivary esterase (Set) was practical in paternity and personal identification.

The effect of magnetic stent on coronary restenosis after percutaneous transluminal coronary angioplasty in dogs

OBJECTIVE

To investigate the effects of magnetic stents on coronary restenosis after percutaneous transluminal coronary angioplasty (PTCA).

METHODS

Twenty dogs were randomly divided into the control and experimental groups, each with 10 dogs. The control group was given common Palmaz-stents in the 6-8 segment of left anterior descending coronary artery or in the 11-14 segment of the left circumflexus. The experimental group was given magnetic stents in the same parts of the coronary arteries. The dogs were not given antiplatelet or anticoagulant drugs before or after the operation. Six months later, the 20 dogs were subjected to coronary angiographies, and then were sacrificed. Three centimeter long segments of the target vessels were cut for pathological examination.

RESULTS

The degree of restenosis in 3 dogs of the control group was more than 50%, but none in the experimental group experienced restenosis. The average thickness of the tunica intima of the target artery was 2.98 +/- 0.56 mm in the control and 1.13 +/- 0.41 mm in the experimental group (P < 0.05).

CONCLUSION

Magnetic stents could have a significant preventive effect on coronary restenosis.

Hybrid vectors based on adeno-associated virus serotypes 2 and 5 for muscle-directed gene transfer

Vectors based on hybrids consisting of adeno-associated virus types 2 (ITRs and Rep) and 5 (Cap) were evaluated for muscle-directed gene transfer (called AAV2/5). Evaluation in immune-competent mice revealed greater transduction efficacy with AAV2/5 than with AAV2 and no cross-neutralization between AAV2/5 and AAV2. Interestingly, we saw no immunologic evidence of previous exposure to AAV5 capsids in a large population of healthy human subjects.

Toward high-throughput genotyping: dynamic and automatic software for manipulating large-scale genotype data using fluorescently labeled dinucleotide markers

To efficiently manipulate large amounts of genotype data generated with fluorescently labeled dinucleotide markers, we developed a Microsoft database management system, named. offers several advantages. First, it accommodates the dynamic nature of the accumulations of genotype data during the genotyping process; some data need to be confirmed or replaced by repeat lab procedures. By using, the raw genotype data can be imported easily and continuously and incorporated into the database during the genotyping process that may continue over an extended period of time in large projects. Second, almost all of the procedures are automatic, including autocomparison of the raw data read by different technicians from the same gel, autoadjustment among the allele fragment-size data from cross-runs or cross-platforms, autobinning of alleles, and autocompilation of genotype data for suitable programs to perform inheritance check in pedigrees. Third, provides functions to track electrophoresis gel files to locate gel or sample sources for any resultant genotype data, which is extremely helpful for double-checking consistency of raw and final data and for directing repeat experiments. In addition, the user-friendly graphic interface of renders processing of large amounts of data much less labor-intensive. Furthermore, has built-in mechanisms to detect some genotyping errors and to assess the quality of genotype data that then are summarized in the statistic reports automatically generated by. The can easily handle >500,000 genotype data entries, a number more than sufficient for typical whole-genome linkage studies. The modules and programs we developed for the can be extended to other database platforms, such as Microsoft SQL server, if the capability to handle still greater quantities of genotype data simultaneously is desired.

Intravitreal injection of plasminogen kringle 5, an endogenous angiogenic inhibitor, arrests retinal neovascularization in rats

AIMS/HYPOTHESIS

Plasminogen kringle 5 is an endogenous angiogenic inhibitor. The purpose of the present study was to explore the potential application of kringle 5 in the treatment of retinal neovascularization.

METHODS

Plasminogen kringle 5 was expressed in E. coli and affinity-purified. Its anti-angiogenic activity was determined in cultured primary human capillary endothelial cells. Retinal neovascularization was induced in newborn rats by exposure to hyperoxia and then normoxia. Kringle 5 was intravitreally injected into the rat model. Retinal neovascularization was visualized by fluorescein angiography on flat-mounted retina and quantified by counting preretinal vascular cells.

RESULTS

Plasminogen kringle 5 inhibited primary endothelial cells but not retinal neuronal cells, suggesting cell type-specific inhibition. The oxygen-induced retinopathy rat model showed an over-expression of vascular endothelial growth factor, preretinal neovascularization and haemorrhage. Intravitreal injection of kringle 5 before the development of neovascularization resulted in fewer neovascular tufts and pre-retinal vascular cells than in control rats with PBS injection (p < 0.01). Moreover, injection of kringle 5 after the development of neovascularization inhibited the increase in the preretinal vascular cells (p < 0.05). These results suggest that kringle 5 both prevents the development and arrests the progression of retinal neovascularization. The injection of kringle 5 did not result in any detectable inflammatory response in the retina or histological toxicity to retina neurons and pre-existing vessels.

CONCLUSION/INTERPRETATION

These observations suggest that intravitreal delivery of angiogenic inhibitors could have therapeutic benefits in neovascular diseases of the retina.

[Stratified 'capture-recaptured' methodology in the estimation on the number of cancer incidence cases]

OBJECTIVE

To develop a new method in estimating the number of cancer incidence in Yuexiu district in Guangzhou.

METHODS

Data of cancer incidence was collected through hospital records and death certificates to develop a stratified capture-recaptured model. Related procedures for the parameter estimation were given and implemented on SAS language.

RESULTS

Estimated numbers of both male and female cancer incidence in Yuexiu district were 610 and 520 respectively. The estimated miss-reporting rates on both male and female cancer incidence from hospital records and death certificates were 8.5% and 5.4% respectively.

CONCLUSION

The result of simulation studies showed that stratified "capture-recaptured" model proposed in this paper was reliable for the estimation of the number of cancer incidence cases.

[Biochemical remodeling of myocardial collagen and its relation to cardiac renin-angiotensin system in rats after myocardial infarction]

OBJECTIVE

This study aimed at the biochemical remodeling of myocardial collagen and its relation to cardiac renin-angiotensin system (RAS) after myocardial infarction(MI).

METHODS

The ventricular and plasma angiotensin II (Ang II) content, total collagen content, and collagen concentration in left ventricle(LV) and right ventricle(RV) of MI and sham-operated control(SOC) rats on 3, 15 and 42 days after operation were measured dynamically by means of radioimmunoassay etc.

RESULTS

The plasma Ang II content increased only in MI rats on day 3. The Ang II content in LV of the MI group increased markedly on day 3 after MI as compared with that of the SOC group. It sustained at this higher level on the 15th and 42th days, and the similar changes were observed in RV as well. The biochemical remodeling of collagen in LV and RV occurred after MI and the remodeling of collagen showed similar patterns with its Ang II content, except that collagen remodeling in RV was delayed than the change of Ang II content.

CONCLUSION

The cardiac RAS was obviously activated after MI. Ventricular Ang II might play an important role in the biochemical remodeling of myocardial collagen, and its role was independent of circulating RAS.

Unbalanced expression of VEGF and PEDF in ischemia-induced retinal neovascularization

Retinal levels of vascular endothelial growth factor (VEGF) and pigment epithelium-derived factor (PEDF), an angiogenic inhibitor, were measured and correlated with the ischemia-induced retinal neovascularization in rats. The retinas with neovascularization showed a 5-fold increase in VEGF while 2-fold decrease in PEDF, compared to the age-matched controls, resulting in an increased VEGF/PEDF ratio. The time course of the VEGF/PEDF ratio change correlated with the progression of retinal neovascularization. Changes in the VEGF and PEDF mRNAs preceded their protein level changes. These results suggest that an unbalance between angiogenic stimulators and inhibitors may contribute to retinal neovascularization.

N-terminal cleavage of bax by calpain generates a potent proapoptotic 18-kDa fragment that promotes bcl-2-independent cytochrome C release and apoptotic cell death

Upon apoptosis induction, the proapoptotic protein Bax is translocated from the cytosol to mitochondria, where it promotes release of cytochrome c, a caspase-activating protein. However, the molecular mechanisms by which Bax triggers cytochrome c release are unknown. Here we report that before the initiation of apoptotic execution by etoposide or staurosporin, an active calpain activity cleaves Bax at its N-terminus, generating a potent proapoptotic 18-kDa fragment (Bax/p18). Both the calpain-mediated Bax cleavage activity and the Bax/p18 fragment were found in the mitochondrial membrane-enriched fraction. Cleavage of Bax was followed by release of mitochondrial cytochrome c, activation of caspase-3, cleavage of poly(ADP-ribose) polymerase, and fragmentation of DNA. Unlike the full-length Bax, Bax/p18 did not interact with the antiapoptotic Bcl-2 protein in the mitochondrial fraction of drug-treated cells. Pretreatment with a specific calpain inhibitor calpeptin inhibited etoposide-induced calpain activation, Bax cleavage, cytochrome c release, and caspase-3 activation. In contrast, transfection of a cloned Bax/p18 cDNA into multiple human cancer cell lines targeted Bax/p18 to mitochondria, which was accompanied by release of cytochrome c and induction of caspase-3-mediated apoptosis that was not blocked by overexpression of Bcl-2 protein. Therefore, Bax/p18 has a cytochrome c-releasing activity that promotes cell death independent of Bcl-2. Finally, Bcl-2 overexpression inhibited etoposide-induced calpain activation, Bax cleavage, cytochrome c release, and apoptosis. Our results suggest that the mitochondrial calpain plays an essential role in apoptotic commitment by cleaving Bax and generating the Bax/p18 fragment, which in turn mediates cytochrome c release and initiates the apoptotic execution.

Nitric oxide synthase is induced in tumor promoter-sensitive, but not tumor promoter-resistant, JB6 mouse epidermal cells cocultured with interferon-gamma-stimulated RAW 264.7 cells: the role of tumor necrosis factor-alpha

Expression of inducible nitric oxide synthase (iNOS) has been reported to be involved in certain organs of potential tumorigenesis, including the stomach and colon. The mechanisms for iNOS expression in epithelial cells, however, are not fully understood. In the present study, we investigated the role of macrophages in epithelial iNOS expression by coculturing a stimulated murine macrophage-like cell line, RAW 264.7, with either tumor promoter-sensitive (P+) or promoter-resistant (P-) JB6 murine epidermal cells. After monoculture, treatment of RAW 264.7 cells with IFN-gamma for 24 h generated a large amount of nitrite (NO2-), as reported previously, whereas no increase in NO2- concentration was observed in the IFN-gamma-treated P+ or P-subclones. Interestingly, when IFN-gamma-treated RAW 264.7 cells were cocultured with P+ but not P- cells, we observed a marked increase in NO2- concentration (30.8+/-3.6 microM), which significantly exceeded (P < 0.01) the sum of the concentrations (20.0+/-2.3 microM) added from each cell line monoculture. Western blotting analysis revealed that, after coculture, iNOS protein was up-regulated 55-fold more than the control in JB6 P+ but not in P- cells. IFN-gamma-treated RAW 264.7 cells secreted proinflammatory cytokines, including tumor necrosis factor (TNF)-alpha and interleukin (IL)-1beta. The addition of IFN-gamma-treated RAW 264.7 cell-conditioned media to P+ subclones led to a significant enhancement of NO2- formation that was diminished by the TNF-alpha-specific but not IL-1beta-specific antibody. When combined with IFN-gamma, the recombinant TNF-alpha (1-100 ng/ml) enhanced NO2- formation in JB6 P+ cells, whereas IL-1beta (1-100 ng/ml) did not. These results led us to conclude that IFN-gamma-treated RAW 264.7 cells release TNF-alpha to induce iNOS expression in promoter-sensitive JB6 cells. Thus, we propose the hypothesis that macrophages stimulate neoplastic cells with TNF-alpha via a paracrine loop to induce epithelial iNOS protein expression.

Regulation of tumor cell apoptotic sensitivity during the cell cycle (Review)

Understanding how current chemotherapeutic modalities induce apoptosis is critical to designing better anti-cancer agents. This review is concerned with how pharmacological agents induce tumor cell apoptosis in a cell cycle-dependent manner. Recent experiments demonstrate that expression of several apoptotic regulatory proteins (such as Bcl-2, Bax, p53, and Survivin) are differentially regulated according to the phases of the cell cycle. This cell cycle-dependent regulation in turn contributes to increased drug sensitivity in different phases of the cell cycle. It is therefore likely that the cell cycle-dependent expression of cell death proteins plays a role in regulating chemosensitivity and apoptotic commitment of human tumor cells.

G(1) phase-dependent expression of bcl-2 mRNA and protein correlates with chemoresistance of human cancer cells

Recent experiments suggest an interconnection between cell proliferation and programmed cell death (apoptosis), although the detailed molecular mechanisms remain unclear. We have hypothesized that expression of some apoptosis regulators is cell cycle-dependent, which in turn influences tumor cell chemosensitivity in a cell cycle-dependent fashion. To test these hypotheses, we synchronized human leukemia Jurkat T, Neo (using aphidicolin), breast cancer MCF-7, normal fibroblast, and simian virus 40-transformed cells (by aphidicolin or serum starvation), and measured levels of several Bcl-2 family proteins. The highest expression of Bcl-2 protein was found in the G(1) phase of all the five cell lines tested. In contrast, levels of Bax protein remained relatively unchanged in four of the cell lines, and levels of Bcl-X(L), Bcl-X(S), and Bak proteins showed little or no cell cycle-dependent changes in Jurkat T cells. Similar to the changes in Bcl-2 protein levels, its mRNA expression was also G(1) phase-specific, whereas the level of a Bcl-2 cleavage activity remained constitutive. When treated with an anticancer drug (etoposide or cisplatin) or the kinase inhibitor staurosporin, the cells containing a high G(1) population and a high Bcl-2 protein level were much more resistant to the induced apoptosis than the cells containing a high S phase population and a low Bcl-2 protein level. Constitutive overexpression of Bcl-2 protein in Jurkat T cells completely blocked the S phase-associated sensitivity to these apoptosis stimuli. The cell cycle-dependent Bcl-2 protein expression seems to contribute to the regulation of chemosensitivity and apoptotic commitment of human tumor cells.

Mitogen-activated protein kinase inhibitors suppress prostaglandin F(2alpha)-induced myosin-light chain phosphorylation and contraction in iris sphincter smooth muscle

The purpose of this study was to investigate the potential role of mitogen-activated protein (MAP) kinase in contraction by monitoring MAP kinase phosphorylation (activation) and contraction during agonist stimulation of cat iris sphincter smooth muscle. Changes in tension in response to prostaglandin F(2alpha), latanoprost, a prostaglandin F(2alpha) analog used as an anti-glaucoma drug, and carbachol were recorded isometrically, and MAP kinase activation was monitored by Western blot using a phosphospecific p42/p44 MAP kinase antibody. We found that treatment of the muscle with 2'-Amino-3'-methoxyflavone (PD98059) (10 microM), a specific inhibitor of MAP kinase kinase (MEK), inhibited significantly prostaglandin F(2alpha)- and latanoprost-induced phosphorylation and contraction, but had little effect on those evoked by carbachol. Prostaglandin F(2alpha) increased MAP kinase phosphorylation in a concentration-dependent manner with EC(50) value of 1.1 x 10(-8) M and increased contraction with EC(50) of 0.92 x 10(-9) M. The MAP kinase inhibitors PD98059, Apigenin and 1,4-Diamino-2,3-dicyano-1, 4bis(2-aminophenylthio)butadiene (UO126) inhibited prostaglandin F(2alpha)-induced contraction in a concentration-dependent manner with IC(50) values of 2.4, 3.0 and 4.8 microM, respectively. PD98059 had no effect on prostaglandin F(2alpha)- or on carbachol-stimulated inositol-1,4,5-trisphosphate (IP(3)) production. In contrast, the MAP kinase inhibitor inhibited prostaglandin F(2alpha)-induced myosin-light chain (MLC) phosphorylation, but had no effect on that of carbachol. N-[2-(N-(4-Chloro-cinnamyl)-N-methylaminomethyl)phenyl]-N-[2- hydroxyethyl]-4-methoxybenzenesulfonamide (KN-93) (10 microM), a Ca(2+)-calmodulin-dependent protein kinase inhibitor, and Wortmannin (10 microM), an MLC kinase inhibitor, inhibited significantly (by 80%) prostaglandin F(2alpha)- and carbachol-induced contraction. It can be concluded that in this smooth muscle p42/p44 MAP kinases are involved in the mechanism of prostaglandin F(2alpha)-, but not in that of carbachol, induced contraction. In addition, these data clearly indicate that the stimulation of the iris sphincter with prostaglandin F(2alpha) and carbachol activate two distinct pathways, the MAP kinase pathway and the Ca(2+) mobilization pathway.

Purification of recombinant adeno-associated virus vectors by column chromatography and its performance in vivo

Recombinant adeno-associated virus (AAV) holds much promise for human gene therapy. While evidence indicates that AAV mediates long-term gene transfer in several different tissues, difficulty in preparing and purifying this viral vector in large quantities remains a major obstacle for evaluating AAV vectors in clinical trials. The current method of purification, based on sedimentation through cesium chloride, is not scaleable and yields product of insufficient quality. In this article we report a new technique for purifying AAV, using a fully closed two-column chromatography system. Yields of AAV vectors purified by this method are high, potency is increased, and the purity of column-purified preparations is substantially improved. We previously reported a novel method to generate AAV based on an AAV Rep/Cap-containing cell line (B50) and an Ad-AAV hybrid virus, which is amenable to scale-up in bioreactors. By combining the new, fully scaleable purification process we report here with the B50/hybrid production method, it would be feasible to prepare AAV vectors to the scale and purity required for clinical and potential commercial applications.

N-terminal cleavage of bax by calpain generates a potent proapoptotic 18-kDa fragment that promotes bcl-2-independent cytochrome C release and apoptotic cell death

Upon apoptosis induction, the proapoptotic protein Bax is translocated from the cytosol to mitochondria, where it promotes release of cytochrome c, a caspase-activating protein. However, the molecular mechanisms by which Bax triggers cytochrome c release are unknown. Here we report that before the initiation of apoptotic execution by etoposide or staurosporin, an active calpain activity cleaves Bax at its N-terminus, generating a potent proapoptotic 18-kDa fragment (Bax/p18). Both the calpain-mediated Bax cleavage activity and the Bax/p18 fragment were found in the mitochondrial membrane-enriched fraction. Cleavage of Bax was followed by release of mitochondrial cytochrome c, activation of caspase-3, cleavage of poly(ADP-ribose) polymerase, and fragmentation of DNA. Unlike the full-length Bax, Bax/p18 did not interact with the antiapoptotic Bcl-2 protein in the mitochondrial fraction of drug-treated cells. Pretreatment with a specific calpain inhibitor calpeptin inhibited etoposide-induced calpain activation, Bax cleavage, cytochrome c release, and caspase-3 activation. In contrast, transfection of a cloned Bax/p18 cDNA into multiple human cancer cell lines targeted Bax/p18 to mitochondria, which was accompanied by release of cytochrome c and induction of caspase-3-mediated apoptosis that was not blocked by overexpression of Bcl-2 protein. Therefore, Bax/p18 has a cytochrome c-releasing activity that promotes cell death independent of Bcl-2. Finally, Bcl-2 overexpression inhibited etoposide-induced calpain activation, Bax cleavage, cytochrome c release, and apoptosis. Our results suggest that the mitochondrial calpain plays an essential role in apoptotic commitment by cleaving Bax and generating the Bax/p18 fragment, which in turn mediates cytochrome c release and initiates the apoptotic execution.

[Laser-induced fluorescence (LIF) spectrum of colorectal cancer in vivo]

OBJECTIVE

To study the LIF spectrum of colorectal cancer, adenomas, chronic colitis and normal colon tissue in vivo, with special emphasis on precancerous lesions.

METHODS

A nitrogen laser (wavelength 337 nm) beam was introduced through endoscopic colonoscope and the fluorescence emission was recorded. An optical multichannel analyzer (OMA III) was used to analyze the fluorescence emission spectrum. A total of 83 patients was examined.

RESULTS

The emission spectrum of LIF recorded on colorectal cancer and normal tissue showed significant differences in intensity and shape. (1) The normal tissue had higher intensity than that of cancer tissue. (2) The main peak wavelength of cancer moved to the red. (3) The minor peak of the cancer tissue fell more slowly than that of the normal tissue. Intensity of the main peak (x1), intensity ratio of 400 to 530 nm (x2) and the integrated LIF intensity (350-600 nm) (x3) were used as parameters to obtain an equation. The sensitivity and specificity of LIF for diagnosis of colorectal cancer was 83.3% and 94.4%, respectively. In 87.1% of moderate and severe dysplastic adenomatous polyps, the fluorescence spectrum was abnormal.

CONCLUSION

In vivo, the LIF spectrum can be used to distinguish colorectal cancer from normal colon, especially from dysplasia. It plays an important role in the early diagnosis of colorectal cancer.

Prolonged correction of hyperlipidemia in mice with familial hypercholesterolemia using an adeno-associated viral vector expressing very-low-density lipoprotein receptor

Adeno-associated viral vectors were used to deliver the gene for very-low-density lipoprotein (VLDL) receptor (VLDLR) to liver of a murine model of familial hypercholesterolemia (FH). Infusion of adeno-associated virus-VLDLR into the portal circulation of FH mice resulted in a 40% reduction in serum cholesterol and triglyceride that was stable for the duration of the study (30 weeks). Fractionation of serum lipids revealed a reduction of both VLDL and low-density lipoprotein. Expression of transgene-derived VLDLR was confirmed in livers of recipient animals by Western blot analysis and immunohistochemistry; vector DNA was present at 1 copy/cell. Vector-treated animals had significantly less lipid accumulation in liver and reduced atherosclerosis in the aorta.

Tissue inhibitor of metalloproteinases-1 undergoes microsecond to millisecond motions at sites of matrix metalloproteinase-induced fit

The N-terminal, matrix metalloproteinase (MMP)-inhibitory fragment of recombinant, human tissue inhibitor of metalloproteinases (TIMP-1) exhibits varied backbone dynamics and rigidity. Most striking is the presence of chemical exchange in the MMP-binding ridge reported to undergo conformational change upon MMP binding. Conformational exchange fluctuations in microseconds to milliseconds map to the sites of MMP-induced fit at residues Val29 through Leu34 of the AB loop and to the Ala65 and Cys70 "hinges" of the CD loop of TIMP-1. Slow chemical exchange is also present at the type I turn of the EF loop at the base of the MMP-binding ridge. These functional slow motions and other fast internal motions are evident from backbone (15)N spin relaxation at 500 and 750 MHz, whether interpreted by the model-free formalism with axial diffusion anisotropy or by the reduced spectral density approach. The conformational exchange is confirmed by its deviation from the trend between R(2) and the cross-correlation rate eta. The magnetic field-dependence indicates that the chemical exchange broadening in the AB and CD loops is fast on the time-scale of chemical shift differences. The conformational exchange rates for most of these exchanging residues, which can closely approach MMP, appear to be a few thousand to several thousand per second. The slow dynamics of the TIMP-1 AB loop contrast the picosecond to nanosecond dynamics reported in the longer TIMP-2 AB loop.

Adeno-associated virus mediates long-term gene transfer and delivery of chondroprotective IL-4 to murine synovium

Treatments for rheumatoid arthritis and other inflammatory arthropathies are often ineffective at preventing joint destruction. Long-term genetic modification of the cells lining the joint space (synoviocytes) in vivo represents a potential method for the treatment of these chronic conditions. However, a vector capable of efficiently transducing synoviocytes in vivo for a persistent period has not been available. The present report describes the genetic modification of synoviocytes in vivo using recombinant adeno-associated virus. High-titer adeno-associated virus encoding the gene for Escherichia coli beta-galactosidase was injected into the knee joints of mice. Synovial tissues were then examined for beta-galactosidase transgene expression by in situ staining and by fluorometry. High-efficiency, persistent transgene expression was observed in the synovium with no evidence of vector-induced inflammation. Expression was observed for at least 7 months and was higher in arthritic than nonarthritic mice. Gene transfer of murine IL-4 to the joints of mice with collagen-induced arthritis led to detectable levels of IL-4 in the joint and protection from articular cartilage destruction. These data suggest that adeno-associated virus may be a useful vector for gene delivery to the synovium for the treatment of inflammatory arthropathies.

[Analysis of the mental state of burn patients with postburn phobic neurosis]

OBJECTIVE

To analyze the mental state of burn patients with postburn neurosis, so as to pave the way for solving the problem.

METHODS

The clinical symptoms and the mental states of forty-three burn patients with phobic neurosis were analyzed in terms of age, sex, severity of burn injury and methods of burn management in accordance with phobic objects.

RESULTS

(1) Simple phobia and circumstance phobia were mainly found in children, whereas sick phobia and social phobia were in adults. (2) Phobic neurosis happened more often in female, especially those above 12 years old, than in male patients. (3) The burn injury severity was positively correlated with the incidence of phobic neurosis. (4) There was higher incidence of phobic neurosis in patients treated with bandaging than those with exposure method.

CONCLUSION

It was very important to close burn wound as soon as possible, to correct deformity, to improve dysfunction, to perform cosmesis and plastic surgery and to rebuild patients self-esteem in order to prevent or decrease the incidence of postburn phobic neurosis.

[Study on the chemical form and extraction rate of Cr, Cu, Fe, Mn, Ni and Zn in tea]

The content of Cr, Cu, Fe, Mn, Ni and Zn in the tea commonly available in China market were measured by inductivity coupled plasma-optical emission spectrometry (ICP-OES). The extraction rates of the six elements in tea leachate were measured. The solubilitied were 39.8% for Cr, 42.5% for Cu, 8.6% for Fe, 45.5% for Mn, 87.1% for Ni and 71.0% for Zn. The process of making tea leachate affects the elements extraction rates. The content of the microelements in tea leave extracts decreases gradually with the processing. About 80% of Cr, Cu, Mn, Ni and Zn and 60% of Fe were in the first infusion of tea. Moreover, the chemical forms of six elements were determined. The ratios of organic to inorganic forms were 0.33 for Cr, 0.022 for Cu, 0.18 for Fe, 0.002 for Mn, 0.01 for Ni and 0.18 for Zn. It is concluded that the six elements from the tea infusion extracted from 5 g tea are too little to meet the recommend dietary allowance (RDA). Therefore, tea is not a rich food source of Cr, Cu, Fe, Mn, Ni and Zn.

Randomized comparative trial in parous women of the frameless GyneFix and the TCu380A intrauterine devices: long-term experience in a Chinese family planning clinic

OBJECTIVE

To compare the clinical performance of two intrauterine devices (the frameless GyneFix intrauterine device (IUD) and the TCu380A IUD) during long-term use.

STUDY DESIGN

This was a randomized comparative study. A total of 157 insertions of the GyneFix IUD were compared with 156 insertions of the TCu380A IUD in the Tianjin Municipal Institute for Family Planning, China. Only parous women were included in the study. Insertions were conducted by the first three authors. The trial extended over a 9-year period, with over 10,000 woman-months of experience.

RESULTS

The study showed that both devices are highly efficacious. No pregnancies occurred with the GyneFix IUD (cumulative pregnancy rate 0.0), compared to one pregnancy with the TCu380A IUD (cumulative pregnancy rate 0.64). The cumulative expulsion rate with the GyneFix IUD was 1.91 (three expulsions occurred, two of which were during the first 6 months), compared to a cumulative expulsion rate of 5.13 (eight expulsions) with the TCu380A (p = 0.1112). The total use-related discontinuation rate (terminations were mainly due to bleeding disturbances) was significantly lower (p = 0.0051) with the GyneFix IUD (4.46) than with the TCu380A IUD (14.10) and resulted in a higher rate of continuation with the GyneFix IUD compared to the TCu380A IUD (92.36 versus 83.97). Neither perforations nor cases of pelvic inflammatory disease were encountered with either device in this study, demonstrating the safety of the anchoring system.

CONCLUSION

The results of the present clinical trial are in agreement with the findings of other multicenter, randomized, comparative, clinical trials that have investigated these two IUDs in China, as well as with the findings of other large-scale international studies conducted with the frameless IUD.

[Multivariate analysis of prognostic factors in renal cell carcinoma]

OBJECTIVE

To assess the effect of prognostic factors on renal cell carcinoma (RCC).

METHODS

316 cases of RCC were reviewed retrospectively. Their survival rates were calculated by Kaplan-Meier method and statistical differences were determined by Log-rank test. Significant prognostic factors were evaluated by Cox's multivariate proportional hazard model.

RESULTS

After 40.3 +/- 18.5 month follow-up, the overall 5-year survival rate was 62.3%. By multivariate analysis, nine factors were included in Cox's multivariate proportional hazard model. M was the most important prognostic factor in RCC (P = 0.0013), and the others in turn were T (P = 0.0182), age (P = 0.0347), performance status (P = 0.0423), N (P = 0.0471), lymphadenectomy (P = 0.0542), grade (P = 0.0775), serum albumin (P = 0.1536), and serum creatinine (P = 0.4543).

CONCLUSIONS

The significant prognostic factors in RCC were T, N, and M. Age and performance status showed the effect on prognosis of RCC. Lymph-node dissection also revealed a meaningful effect on relative lower stage of RCC.

[Study on beta 2 adrenergic receptor genetic polymorphisms in asthmatics in the people of the Han nationality of northern China]

OBJECTIVE

To analyze the association between beta 2-AR genetic polymorphism and asthma in the people of the Han nationality of northern China.

METHODS

Allele Specific-PCR techniques were used to determine 16, 27 and 164 locus alleles of beta 2-AR genetic polymorphisms in 58 unrelated patients with asthma and 89 healthy controls from the people of the Han nationality of northern China.

RESULTS

(1) The distribution frequency of genotype beta 2-AR 16 loci: Arg/Arg genotype accounts for 13%, Arg/Gly 76% and Gly/Gly 11%. The beta 2-AR 27 loci: Gln/Gln genotype accounts for 36%, Gln/Glu 55% and Glu/Glu 9%. The beta 2-AR 164 loci: Thr/Thr genotype accounts for 30%, Thr/Ile 53% and Ile/Ile 17%. (2) The frequency of genotype beta 2-AR 16 loci in asthmatics: Arg/Arg genotype accounts for 24%, Arg/Gly 45% and Gly/Gly 31%. There was a significant increase in the frequency of Gly/Gly genotype in asthmatics compared with healthy group(OR = 4.0, 95% CI 1.7-9.7), but there was no significant difference in the allele frequency of asthmatics compared with healthy group. The frequency of genotype beta 2-AR 27 loci in asthmatics: Gln/Gln genotype accounts for 34%, Gln/Glu 56% and Glu/Glu 10%. There was no significant difference in the allele frequency of asthmatics compared with healthy group. The frequency of genotype beta 2-AR 164 loci in asthmatics: Thr/Thr genotype accounts for 10%, Thr/Ile 83% and Ile/Ile 7%. There was no significant difference in the frequency of Ile/Ile genotype in asthmatics compared with healthy group, and in the allele frequency of asthmatics compared with healthy group. In addition, our study reveals that beta 2-AR 16 locus genetic polymorphism is in association with asthmatic severity.

CONCLUSIONS

These results suggest that beta 2-AR 16 locus genetic polymorphism is correlated with asthma severity in the people of the Han nationality of northern China.

Rescue of skeletal muscles of gamma-sarcoglycan-deficient mice with adeno-associated virus-mediated gene transfer

In humans, a subset of cases of Limb-girdle muscular dystrophy (LGMD) arise from mutations in the genes encoding one of the sarcoglycan (alpha, beta, gamma, or delta) subunits of the dystrophin-glycoprotein complex. While adeno-associated virus (AAV) is a potential gene therapy vector for these dystrophies, it is unclear if AAV can be used if a diseased muscle is undergoing rapid degeneration and necrosis. The skeletal muscles of mice lacking gamma-sarcoglycan (gsg-/- mice) differ from the animal models that have been evaluated to date in that the severity of the skeletal muscle pathology is much greater and more representative of that of humans with muscular dystrophy. Following direct muscle injection of a recombinant AAV [in which human gamma-sarcoglycan expression is driven by a truncated muscle creatine kinase (MCK) promoter/enhancer], we observed significant numbers of muscle fibers expressing gamma-sarcoglycan and an overall improvement of the histologic pattern of dystrophy. However, these results could be achieved only if injections into the muscle were prior to the development of significant fibrosis in the muscle. The results presented in this report show promise for AAV gene therapy for LGMD, but underscore the need for intervention early in the time course of the disease process.

[A correlative study on the thyroid stimulating hormone levels between pregnant women and their newborns]

OBJECTIVE

The correlation between serum thyroid stimulating hormone (TSH) levels in pregnant women and their neonatal cord blood was explored.

METHODS

With immunoradiometric assay (IRMA) technique, the serum TSH levels of 500 pregnant women and the cord blood TSH levels in the iodine deficiency areas (study group) were tested, while the TSH levels of 100 normal pregnant women and their newborns in iodine sufficient areas (control group) were compared.

RESULTS

(1) In pregnant women, the mean serum TSH level in study group was significantly higher than that of control [(5.25 +/- 2.43) mU/L VS (4.69 +/- 1.34) mU/L, P < 0.01]. In newborns, the mean cord blood TSH level in study group was significantly higher than that of control (6.83 +/- 4.71) mU/L VS (5.32 +/- 3.02) mU/L, P < 0.001]. (2) The serum TSH levels in pregnant women were positively correlated with the cord blood TSH levels of their newborns in both groups. (3) The serum TSH levels of pregnant women was negatively correlated with their free triiodothy-ronine levels.

CONCLUSION

The iodine nutrition status of newborns could be evaluated by monitoring the TSH levels of pregnant women.

Interleukin-2 expression in human carcinoma cell lines and its role in cell cycle progression

Human carcinomas were shown to express mRNA and protein for IL-2R alpha, beta and gamma chains. Recently, human carcinomas were also shown to constitutively express protein and mRNA for IL-2 in vivo and in vitro. Here we report that the expression levels of cytoplasmic IL-2 as well as IL-2Rbeta- and gamma-chain in human carcinoma cells change during the cell cycle progression. Carcinoma cells synchronized in the G2/M phase of the cell cycle expressed significantly more intracytoplasmic IL-2 as well as IL-2Rbeta and gamma proteins than tumor cells in the G0/G1 phase. The level of mRNA for IL-2 was 5-10-fold higher in the M phase than in the G0/G1-phase, as shown by quantitative competitive RT-PCR. Expression of the cyclin-dependent kinase (CDK) inhibitor p27kip1 in these carcinoma cells was found to be high in the G0/G1 phase, nearly absent in the S phase, and it increased again in the G2/M phase of the cell cycle. In synchronized cells, the decrease in p27 expression coincided with high levels of expression of IL-2. Using the IL-2 specific antisense oligonucleotide to block synthesis of endogenous IL-2 in tumor cells, we observed increased levels of p27 as well as p21. The antisense oligonucleotides specific for p27 or p21 blocked expression of these proteins but not of IL-2. Thus, endogenous IL-2 is important in regulating expression of p27 as well as p21 and, therefore, in controlling cell cycle progression of tumor cells, while its own expression remains independent of the CDK inhibitors.

NMR structure of tissue inhibitor of metalloproteinases-1 implicates localized induced fit in recognition of matrix metalloproteinases

A high quality solution structure of the matrix metalloproteinase inhibitory N-terminal domain of recombinant human tissue inhibitor of metalloproteinases-1 (N-TIMP-1) has been determined. For the rigidly packed residues, the average RMSD to the mean structure is 0. 57 A for the backbone atoms and 1.00 A for all heavy atoms. Comparison of the solution structure of free N-TIMP-1 with the crystal structure of TIMP-1 bound to the catalytic domain of MMP-3 ( Gomis-R]uth et al., 1997 ) shows that the structural core of the beta barrel flanked by helices is nearly unchanged by the association with MMP-3, evident from a backbone RMSD of 1.15 A. However, clear differences in the conformation of the MMP-binding ridge of free and MMP-bound TIMP-1 suggest induced fit throughout the ridge. The MMP-dependent conformational changes in the ridge include a dramatic bending of AB loop residues Glu28 through Leu34, moderate hinge bending of the CD-loop about residues Ala65 and Cys70, and modest bending of the Cys1 through Pro6 segment. A large number of interresidue Nuclear Overhauser enhancements (NOEs) augmented by stereospecific assignments, torsion restraints, and dipolar couplings (an average of 18 non-trivial restraints per residue) engender confidence in these structural inferences. A tight cluster of three lysine residues and one arginine residue atop beta-strands A and B, and identical among TIMP sequences, form the heart of a highly conserved electropositive patch that may interact with anionic components of the extracellular matrix.

1,1-Dimethylallylcoumarins potently suppress both lipopolysaccharide- and interferon-gamma-induced nitric oxide generation in mouse macrophage RAW 264.7 cells

We investigated the suppressive effects of 16 coumarin-related compounds on both lipopolysaccharide (LPS)- and interferon (IFN)-gamma-induced nitric oxide (NO) generation in a mouse macrophage cell line, RAW 264.7. Notably, coumarins possessing prenyl unit(s) were found to be highly active, a tendency consistent with our previous study. Among the coumarins tested, 1,1-dimethylallylcoumarins showed the highest inhibitory activity. Western blotting analysis revealed that they inhibited NO generation by suppressing inducible NO synthase (iNOS) protein expression. Our ongoing studies suggest that coumarins are prominent natural compounds that attenuate excessive and prolonged NO generation at inflammatory sites.

Cyclic nucleotide phosphodiesterases (PDE) 3 and 4 in normal, malignant, and HTLV-I transformed human lymphocytes

Intracellular cyclic AMP, determined in part by cyclic nucleotide phosphodiesterases (PDEs), regulates proliferation and immune functions in lymphoid cells. Total PDE, PDE3, and PDE4 activities were measured in phytohemagglutinin (PHA)-activated peripheral blood mononuclear cells (PBMC-PHA), normal natural killer (NK) cells, Jurkat and Kit225-K6 leukemic T-cells, T-cell lines transformed with human T-lymphotropic virus (HTLV)-I (a retrovirus that causes adult T-cell leukemia/lymphoma) and HTLV-II (a nonpathogenic retrovirus), normal B-cells, and B-cells transformed with Epstein-Barr virus (EBV). All cells exhibited PDE3 and PDE4 activities but in different proportions. In EBV-transformed B cells, PDE4 was much higher than PDE3. HTLV-I+ T-cells differed significantly from other T-lymphocyte-derived cells in also having a higher proportion of PDE4 activities, which apparently were not related to selective induction of any one PDE4 mRNA (judged by reverse transcription-polymerase chain reaction) or expression of the HTLV-I regulatory protein Tax. In MJ cells (an HTLV-I+ T-cell line), Jurkat cells, and PBMC-PHA cells, the tyrosine kinase inhibitor herbimycin A strongly inhibited PDE activity. Growth of MJ cells was inhibited by herbimycin A and a protein kinase C (PKC) inhibitor, and was arrested in G1 by rolipram, a specific PDE4 inhibitor. Proliferation of several HTLV-I+ T-cell lines, PBMC-PHA, and Jurkat cells was inhibited differentially by forskolin (which activates adenylyl cyclase), the selective PDE inhibitors cilostamide and rolipram, and the nonselective PDE inhibitors pentoxifylline and isobutyl methylxanthine. These results suggest that PDE4 isoforms may be functionally up-regulated in HTLV-I+ T-cells and may contribute to the virus-induced proliferation, and that PDEs could be therapeutic targets in immune/inflammatory and neoplastic diseases.

Pneumolysin, a protein toxin of Streptococcus pneumoniae, induces nitric oxide production from macrophages

Nitric oxide (NO) production by inducible NO synthase (iNOS) during inflammation is an essential element of antimicrobial immunity but can also contribute to host-induced tissue damage. Under conditions of bacterial sepsis, large amounts of NO are produced, causing hypotension, a critical pathological feature of septic shock. In sepsis caused by gram-positive organisms, the bacterial factors contributing to host NO production are poorly characterized. We show that a soluble toxin of Streptococcus pneumoniae, pneumolysin (Pln), is a key component initiating NO production from macrophages. In contrast to wild-type bacteria, a mutant of S. pneumoniae lacking Pln failed to elicit NO production from murine macrophages. Purified recombinant Pln induced NO production at low concentrations and independently of exogenous gamma interferon (IFN-gamma) priming of RAW 264.7 macrophages. However, IFN-gamma was essential for Pln-induced NO production, since primary macrophages from mice lacking the IFN-gamma receptor or interferon regulatory factor 1, a transcription factor essential for iNOS expression, failed to produce NO when stimulated with Pln. In addition, Pln acts as an agonist of tumor necrosis factor alpha and interleukin 6 production in macrophages. The properties of Pln, previously identified as a pore-forming hemolysin, also include a role as a general inflammatory agonist.

Somatic cell mutants resistant to retrovirus replication: intracellular blocks during the early stages of infection

To identify cellular functions involved in the early phase of the retroviral life cycle, somatic cell mutants were isolated after selection for resistance to infection. Rat2 fibroblasts were treated with chemical mutagens, and individual virus-resistant clones were recovered after selection for resistance to infection. Two clones were characterized in detail. Both mutant lines were resistant to infection by both ecotropic and amphotropic murine viruses, as well as by human immunodeficiency virus type 1 pseudotypes. One clone showed a strong block to reverse transcription of the retroviral RNA, including formation of the earliest DNA products. The second clone showed normal levels of viral DNA synthesis but did not allow formation of the circular DNAs normally found in the nucleus. Cell fractionation showed that the viral preintegration complex was present in a form that could not be extracted under conditions that readily extracted the complex from wild-type cells. The results suggest that the DNA was trapped in a nonproductive state and excluded from the nucleus of the infected cell. The properties of these two mutant lines suggest that host gene products play important roles both before and after reverse transcription.

Gene therapy vectors based on adeno-associated virus type 1

The complete sequence of adeno-associated virus type 1 (AAV-1) was defined. Its genome of 4,718 nucleotides demonstrates high homology with those of other AAV serotypes, including AAV-6, which appears to have arisen from homologous recombination between AAV-1 and AAV-2. Analysis of sera from nonhuman and human primates for neutralizing antibodies (NAB) against AAV-1 and AAV-2 revealed the following. (i) NAB to AAV-1 are more common than NAB to AAV-2 in nonhuman primates, while the reverse is true in humans; and (ii) sera from 36% of nonhuman primates neutralized AAV-1 but not AAV-2, while sera from 8% of humans neutralized AAV-2 but not AAV-1. An infectious clone of AAV-1 was isolated from a replicated monomer form, and vectors were created with AAV-2 inverted terminal repeats and AAV-1 Rep and Cap functions. Both AAV-1- and AAV-2-based vectors transduced murine liver and muscle in vivo; AAV-1 was more efficient for muscle, while AAV-2 transduced liver more efficiently. Strong NAB responses were detected for each vector administered to murine skeletal muscle; these responses prevented readministration of the same serotype but did not substantially cross-neutralize the other serotype. Similar results were observed in the context of liver-directed gene transfer, except for a significant, but incomplete, neutralization of AAV-1 from a previous treatment with AAV-2. Vectors based on AAV-1 may be preferred in some applications of human gene therapy.

IL-3 and IL-4 activate cyclic nucleotide phosphodiesterases 3 (PDE3) and 4 (PDE4) by different mechanisms in FDCP2 myeloid cells

In FDCP2 myeloid cells, IL-4 activated cyclic nucleotide phosphodiesterases PDE3 and PDE4, whereas IL-3, granulocyte-macrophage CSF (GM-CSF), and phorbol ester (PMA) selectively activated PDE4. IL-4 (not IL-3 or GM-CSF) induced tyrosine phosphorylation of insulin-receptor substrate-2 (IRS-2) and its association with phosphatidylinositol 3-kinase (PI3-K). TNF-alpha, AG-490 (Janus kinase inhibitor), and wortmannin (PI3-K inhibitor) inhibited activation of PDE3 and PDE4 by IL-4. TNF-alpha also blocked IL-4-induced tyrosine phosphorylation of IRS-2, but not of STAT6. AG-490 and wortmannin, not TNF-alpha, inhibited activation of PDE4 by IL-3. These results suggested that IL-4-induced activation of PDE3 and PDE4 was downstream of IRS-2/PI3-K, not STAT6, and that inhibition of tyrosine phosphorylation of IRS molecules might be one mechnism whereby TNF-alpha could selectively regulate activities of cytokines that utilized IRS proteins as signal transducers. RO31-7549 (protein kinase C (PKC) inhibitor) inhibited activation of PDE4 by PMA. IL-4, IL-3, and GM-CSF activated mitogen-activated protein (MAP) kinase and protein kinase B via PI3-K signals; PMA activated only MAP kinase via PKC signals. The MAP kinase kinase (MEK-1) inhibitor PD98059 inhibited IL-4-, IL-3-, and PMA-induced activation of MAP kinase and PDE4, but not IL-4-induced activation of PDE3. In FDCP2 cells transfected with constitutively activated MEK, MAP kinase and PDE4, not PDE3, were activated. Thus, in FDCP2 cells, PDE4 can be activated by overlapping MAP kinase-dependent pathways involving PI3-K (IL-4, IL-3, GM-CSF) or PKC (PMA), but selective activation of PDE3 by IL-4 is MAP kinase independent (but perhaps IRS-2/PI3-K dependent).

[Studies on flavonoids from Aquilegia oxysepala Trautv. et Mey]

OBJECTIVE

To study the chemical constituents in Aquilegia oxysepala.

METHOD

Various chromatographic techniques were used to separate and purify the constituents. The structures were determined by spectral analysis and chemical evidence.

RESULT

Five flavonoids were isolated from the plant and identified as genkwanin, apigenin, luteonlin, swertisin and tilianin.

CONCLUSION

All these compounds were isolated from the plant for the first time.

[Studies on chemical constituents of Thalictrum atriplex Finet et Gagnep]

OBJECTIVE

To study the chemical constituents in the aerial part of Thalictrum atriplex.

METHOD

Chromatography and spectral analysis were used to isolate and elucidate the constituents.

RESULT

Six compounds were isolated from the aerial part of Thalictrum atriplex, and elucidated as protocatechuic acid, caffeic acid, p-coumaric acid, kaempferol, beta-sitosterol and N-methylcorydaldine.

CONCLUSION

They are all isolated from the plant for the first time.

Novel organization and sequences of five genes encoding all six enzymes for de novo pyrimidine biosynthesis in Trypanosoma cruzi

A 25 kb segment of genomic DNA from Trypanosoma cruzi, the causative agent of Chagas' disease, was sequenced. It contains five genes, pyr1, pyr2, pyr3, pyr4, and pyr6-5, encoding all six enzymes involved in de novo pyrimidine biosynthesis, glutamine-dependent carbamoyl-phosphate synthetase, aspartate carbamoyltransferase, dihydroorotase, dihydroorotate dehydrogenase, and orotidine-5'-phosphate decarboxylase linked with orotate phosphoribosyltransferase, respectively. The pyr genes constitute a polycistronic transcription unit on an 800 kb chromosomal DNA in the order of pyr1, pyr3, pyr6-5, pyr2, and pyr4 from the 5' terminus, with intervening sequences of 2.2, 0.4, 8.1, and 0.8 kb. The amino acid sequences deduced from the trypanosomatid pyr genes, except for pyr6, showed closer similarities to mammalian and yeast sequences, and less similarity to archaeal and bacterial sequences. The last two enzymes encoded by a single gene, pyr6-5, are covalently linked in the order opposite to mammalian pyr5-6, and possess a putative glycosomal targeting signal tripeptide, serine-lysine-leucine, at the C terminus. The calculated isoelectric points of 9.3 and 9.9 are also diagnostic of the glycosomal localization of these enzymes. We conclude that the T. cruzi pyr gene organization represents an early progenitor in de novo pyrimidine biosynthesis in eukaryotic lineage, and that the independent pyr genes may have evolved before the gene fusion events that resulted in the three mammalian-type genes, pyr1-3-2, pyr4, and pyr5-6, for UMP synthesis. Peculiarities in the trypanosomatid pyr6-5 gene product are discussed.

Regulated delivery of therapeutic proteins after in vivo somatic cell gene transfer

Stable delivery of a therapeutic protein under pharmacologic control was achieved through in vivo somatic gene transfer. This system was based on the expression of two chimeric, human-derived proteins that were reconstituted by rapamycin into a transcription factor complex. A mixture of two adeno-associated virus vectors, one expressing the transcription factor chimeras and one containing erythropoietin (Epo) under the control of a promoter responsive to the transcription factor, was injected into skeletal muscle of immune-competent mice. Administration of rapamycin resulted in 200-fold induction of plasma Epo. Stable engraftment of this humanized system in immune-competent mice was achieved for 6 months with similar results for at least 3 months in a rhesus monkey.

Identification of coumarins from the fruit of Citrus hystrix DC as inhibitors of nitric oxide generation in mouse macrophage RAW 264.7 cells

Three known coumarins have been isolated from Citrus hystrix DC as inhibitors of both lipopolysaccharide (LPS) and interferon-gamma (IFN-gamma)-induced nitric oxide (NO) generation in RAW 264.7 cells. The inhibitory activity of bergamottin (IC(50) = 14 microM) was comparable to that of N-(iminoethyl)-L-ornithine (L-NIO) (IC(50) = 7. 9 microM), whereas oxypeucedanin and 5-[(6',7'-dihydroxy-3', 7'-dimethyl-2-octenyl)oxy]psoralen, structurally different from bergamottin only in their side-chain moieties, were notably less active. Using 21 coumarins, we structurally classified various types of coumarins into groups A-C: (A) bearing an isoprenyl (IP) or a geranyl (GR) group, highly active; (B) bearing an IP group cyclized to a coumarin ring, moderately active; (C) bearing an IP group modified with hydroxyl group(s) and/or having other functional groups except for the IP, completely inactive. Cellular uptake studies suggested that coumarins in group C are inactive because of poor permeability to the cell membrane.

A study of multiple biomarkers in coke oven workers--a cross-sectional study in China

We conducted a cross-sectional molecular epidemiological study of coke oven workers exposed to the established carcinogen polycyclic aromatic hydrocarbons (PAHs) to evaluate the relationships between both traditional 'exposure markers' and a series of biomarkers, including urinary 1-hydroxypyrene as a marker of internal dose, leukocyte aromatic DNA adducts as markers of biologically effective dose, serum p53 protein as a response marker and genetic polymorphisms of cytochrome P4501A1 and glutathione S-transferase MI as susceptibility markers. Twenty-five male subjects each were randomly selected from the top, middle and bottom work areas of the oven, and the control plant. They were matched for age and smoking status. The mean levels of PAH exposure, monitored by stationary and personal samplers, and of worker urinary 1-hydroxypyrene differed significantly between the top, middle and bottom of the oven and control work areas. The highest stationary and personal PAH concentrations and 1-hydroxypyrene levels were demonstrated at the top work area. Good correlations were found between the stationary PAH levels, personal PAH levels and urinary 1-hydroxypyrene levels. No positive correlations were demonstrated between aromatic DNA adduct levels and current or cumulative PAH exposure dose. In the presence of genetic polymorphisms of cytochrome P4501A1, a positive correlation was demonstrated between aromatic DNA adducts and urinary 1-hydroxypyrene levels. There was also a significant correlation between serum p53 protein levels and the cumulated benzo[a]pyrene exposure dose. Although these biomarkers have certain limitations, they are applicable to cancer epidemiology, and may contribute to our understanding of the mechanisms of carcinogenesis.

Carbamoyl-phosphate synthetase II in kinetoplastids

Genes for carbamoyl-phosphate synthetase II (CPS II), the first enzyme of de novo pyrimidine biosynthesis, were cloned from kinetoplastids, Trypanosoma cruzi and Leishmania mexicana. T. cruzi CPS II gene encodes a protein of 1524 amino acids that encompasses the glutaminase and CPS domains, but incorporates neither aspartate carbamoyltransferase nor dihydroorotase. The residue corresponding to lysine 993 of Escherichia coli CPS, a residue that characterizes the CPS inhibited by UMP and that is replaced by tryptophan in those inhibited by UTP, is in kinetoplastids a hydrophilic glutamine, in line with the preferential inhibition by UDP of kinetoplastid CPS II.