Effect of trapped energetic particles on the resistive wall mode

A stability analysis for the resistive wall mode is studied in the presence of trapped energetic particles (EPs). When the EPs' beta exceeds a critical value, a fishbonelike bursting mode (FLM) with an external kink eigenstructure can exist. This offers the first analytic interpretation of the experimental observations [Phys. Rev. Lett. 103, 045001 (2009)]. The mode-particle resonances for the FLM and the q=1 fishbone occur in different regimes of the precession frequency of EPs. In certain ranges of the plasma rotation speed and the EPs' beta, a mode conversion can occur between the resistive wall mode and FLM.

Heparin-functionalized collagen matrices with controlled release of basic fibroblast growth factor

Tissue engineering scaffolds with controlled long-term release of growth factors are constructed in an attempt to mimic the intelligent ability of the extracellular matrix (ECM) to release endogenous growth factors. In this study, collagen sponges (Collagen group) were modified by N-(3-dimethylaminopropyl)-N-ethylcarbodiimide hydrochloride (EDC) and N-hydroxysuccinimide (NHS) crosslinking (EDC/NHS group) and heparin immobilization (EDC/NHS-H group), and subsequently seeded with human umbilical vein endothelial cells (HUVECs). Native and modified sponges were pre-adsorbed with basic fibroblast growth factor (bFGF) to evaluate the sustained release and bioactive maintenance of bFGF from the sponges. We found that modified collagen matrices permitted HUVECs to proliferate and migrate well and to distribute uniformly. The EDC/NHS-H group exhibited an excellent sustained-release profile and bioactive maintenance of the pre-adsorbed bFGF as compared with the Collagen and EDC/NHS groups. These results suggest that heparin-functionalized collagen matrices can support a controlled release of bFGF and thus, have potential as a tissue engineering scaffold.

Significance of Pim-3 expression in esophageal squamous cell carcinoma

AIM: To investigate the significance of Pim-3 mRNA and protein expression in esophageal squamous cell carcinoma (ESCC).

METHODS: The expression of Pim-3 mRNA and protein in 45 normal esophageal mucosal specimens, 45 ESCC specimens and 22 tumor-adjacent mucosal specimens was detected by in situ hybridization and immunohistochemistry, respectively.

RESULTS: The positive rates of Pim-3 mRNA expression were 0.00% (0/45), 22.73% (5/22) and 82.22% (37/45) in normal esophageal mucosa, tumor-adjacent mucosa and ESCC tissue, respectively, with a significant difference among the three groups (χ² = 67.450, P < 0.01). Similar results were obtained for Pim-3 protein expression: the positive rates of Pim-3 protein expression were 0.00% (0/45), 18.18% (4/22) and 75.56% (34/45) in normal esophageal mucosa, tumor-adjacent mucosa and ESCC tissue, respectively, with a significant difference among the three groups (χ² = 60.326, P < 0.01). The expression of Pim-3 mRNA and protein was significantly associated with TNM stage and lymph node metastasis in ESCC (both P < 0.05). A positive correlation was noted between the expression of Pim-3 mRNA and protein (γ_p = 0.547, P < 0.01).

CONCLUSION: High expression of Pim-3 mRNA and protein may be closely related to the occurrence and development of ESCC.

Pim-3 knockdown suppresses cell proliferation but promotes apoptosis in esophageal squamous cell carcinoma cell line EC9706

AIM: To investigate the effect of down-regulation of Pim-3 expression on cell proliferation and apoptosis in esophageal squamous cell carcinoma (ESCC) cell line EC9706 and to explore possible molecular mechanisms involved.

METHODS: Small interfering RNA (siRNA) against the Pim-3 gene was transfected into EC9706 cells using Lipofectamine^TM 2000. After transfection, Pim-3 mRNA and protein expression was detected by RT-PCR and Western blot, respectively; cell proliferation was determined using Cell Counting Kit-8 (CCK-8); and apoptosis was measured by flow cytometry. Furthermore, the mRNA and protein expression of P21, Bcl-2 and Bax was detected by RT-PCR and Western blot, respectively.

RESULTS: Pim-3 mRNA and protein expression was significantly down-regulated after transfection with Pim-3 siRNA (both P < 0.05). Compared with untransfected cells and cells transfected with control siRNA, the proliferation of EC9706 cells was significantly restrained after transfection with Pim-3 siRNA for 24, 48, 72 and 96 h (96 h: 0.878 ± 0.061 vs 2.254 ± 0.062 and 2.219 ± 0.064, both P < 0.05), and the early apoptosis rate of EC9706 cells transfected with Pim-3 siRNA was significantly increased (19.70% ± 1.46% vs 5.35% ± 0.80% and 5.50% ± 0.61%, F = 195.692, P = 0.000). In addition, Pim-3 knockdown up-regulated P21 expression but down-regulated Bax and Bcl-2 expression in EC9706 cells (all P < 0.05).

CONCLUSION: Pim-3 plays an important role in the proliferation and apoptosis of EC9706 cells.

Clinical pathological significance of MIC-1 and uPA expression in esophageal squamous cell carcinoma

AIM: To explore the relationship of the protein expression of macrophage inhibitory cytokine-1 (MIC-1) and urokinase plasminogen activator (uPA) with the development, progression, invasion and metastasis of esophageal squamous cell carcinoma (ESCC).

METHODS: The protein expression of MIC-1 and uPA was detected by immunohistochemistry using the streptavidin-peroxidase method in 45 ESCC specimens, 22 tumor-adjacent atypical hyperplastic epithelial specimens and 45 normal esophageal epithelial specimens.

RESULTS: The expression of MIC-1 protein was closely correlated with tumor grade, infiltration, TNM grade and lymphatic metastasis in ESCC (all P < 0.05). The expression of uPA protein was closely correlated with tumor TNM grade and lymphatic metastasis in ESCC (both P < 0.05). The positive rates of MIC-1 expression in ESCC, tumor-adjacent atypical hyperplastic epithelium and normal esophageal epithelium were 64.4% (29/45), 40.9% (9/22) and 13.3% (6/45), respectively, with a significant difference among the three groups (χ² = 24.673, P < 0.01). The positive rates of UPA protein expression in ESCC, tumor-adjacent atypical hyperplastic epithelium and normal esophageal epithelium were 68.9% (31/45), 27.3% (6/22) and 24.4% (11/45), respectively, with a significant difference among the three groups (P < 0.01). There is a positive correlation between the protein expression of MIC-1 and uPA (γ_p = 0.403, P < 0.01).

CONCLUSION: MIC-1 and uPA play important roles in the carcinogenesis, infiltration and metastasis of ESCC. Combined detection of MIC-1 and uPA expression may be a promising molecular parameter for early diagnosis and prognostic evaluation of ESCC.

First Report of Citrus bark cracking viroid and Citrus viroid V Infecting Citrus in China

Citrus is the most cultivated and highest value crop in the 15 southern provinces and municipalities in South China. Trifoliate orange (Poncirus trifoliata) is the main rootstock for citrus cultivars and is known to be susceptible to citrus viroids. Surveys conducted from 1995 to 2007 revealed 42 symptomatic samples from 33 cultivars (21 from sweet oranges (Citrus sinensis), 6 from mandarins (C. reticulata), 2 from satauma mandarins (C. unshiu), 6 from lemons (C. jambhiri), and 7 from mandarin hybrids). Symptoms included stunting, bark scaling, and cracking on the Trifoliate orange rootstock collected from citrus orchards in the Chongqing municipality, Sichuan, Zhejiang, Jiangxi, Hunan, and Yunnan provinces. Of the 42 samples, 27 were cultivars imported from abroad and 15 were local cultivars. Budwood from infected trees were grafted onto Arizona 861-S1 'Etrog citron' (C. medica) on rough lemon (C. jambhiri) rootstock. After more than 12 months, 39 of 42 samples revealed typical viroid symptoms of stunting, epinasty. and leaf rolling on the Etrog indicator plants. In September 2009, total RNA was extracted with TRIZOL Reagent and a one-step multiplex reverse transcription (RT)-PCR assay (3) was used to detect simultaneously Citrus exocortis viroid (CEVd), Citrus bent leaf viroid (CBLVd), Hop stunt viroid (HSVd), and Citrus dwarfing viroid (CDVd). Also, a one-step RT-PCR protocol using two primer pairs targeting the complete genome sequences was used to detect Citrus bark cracking viroid (CBCVd) (1) and Citrus viroid V (CVd-V) (2). Of the 42 samples, 37 and 35 were positive for HSVd and CDVd, respectively. CEVd and CBLVd were found, respectively, in 14 and 13 of 42 samples. CBCVd was detected in cv. Meishan No. 9 (C. sinensis) from Sichuan Province and cvs. Akemi (C. reticulata) and Nishirokaori (C. reticulata) from Zhejiang Province. CVd-V was detected in cvs. Nishirokaori, Haruka (C. tamuranua), and Kiyomi (C. unshiu × C. sinensis) from Zhejiang, Hunan, and Chongqing Province, respectively. Only Meishan No. 9 is a local cultivar, whereas Akemi, Nishirokaori, Haruka, and Kiyomi are cultivars imported from Japan. Of 42 samples, 3 without typical symptoms on Etrog citrons were infected with HSVd only. Of 42 infected citrus plants, 36 harbored more than one viroid species. RT-PCR products of CBCVd and CVd-V were cloned by standard methods. Eight clones for CBCVd (one from Meishan No. 9 [Accession No. HM042742, 284 bp], three from Akemi [Accession Nos. HM042743-HM042745, 283 to 284 bp], and four from Nishirokaori [Accession Nos. HM042746-HM042749, 286 bp]) and six clones for CVd-V (four from Nishirokaori [Accession Nos. HM042750-HM042753, 294 bp], one from Kiyomi [Accession No. HM042754, 294 bp], and one from Haruka [Accession No. HM042755, 294 bp]) were sequenced and deposited in GenBank. BLAST analysis of the CBCVd (Accession No. HM042742) and CVd-V (Accession No. HM042751) sequences revealed highest nucleotide sequence identity (100 and 96%) to a CBCVd isolate from Cuba (Accession No. AJ630360) and a CVd-V isolate from Spain (Accession No. EF617306), respectively. To our knowledge, this is the first report of CBCVd and CVd-V in China. Our finding emphasizes the need for CBCVd and CVd-V indexing in production and distribution of pathogen-free citrus plants in China. References: (1) L. Bernard and N. Duran-Vila. Mol. Cell. Probes 20:105, 2006. (2) P. Serra et al. Phytopathology 98:1199, 2008. (3) X. F. Wang et al. Eur. J. Plant. Pathol. 124:175, 2009.

Significance of RhoC mRNA expression in esophageal squamous cell carcinoma

AIM: To investigate the expression of RhoC mRNA in esophageal squamous cell carcinoma (ESCC) and to explore its correlation with the development and progression of ESCC.

METHODS: Semi-quantitative RT-PCR was used to detect the relative expression levels of RhoC mRNA in 62 ESCC specimens, 31 tumor-adjacent atypical hyperplastic epithelial specimens and 62 normal esophageal epithelial specimens. The distribution of RhoC transcripts in ESCC was determined by in situ hybridization.

RESULTS: The mRNA expression of RhoC was closely correlated with tumor grade, infiltration and lymph node metastasis in ESCC (all P < 0.05). The expression intensity of RhoC mRNA in carcinoma, adjacent atypical hyperplasia epithelium and normal esophageal epithelium were 0.902 ± 0.119, 0. 731 ± 0.065 and 0.653 ± 0.069, respectively, with a significant difference among the three groups (P < 0.01). In situ hybridization analysis demonstrated that RhoC transcripts were detected in the cytoplasm of cells. The positive rates of RhoC mRNA expression in carcinoma, tumor-adjacent atypical hyperplasia epithelium and normal esophageal epithelium were 80.6% (50/62), 32.3% (10/31) and 21.0% (13/62), respectively, with a significant difference among the three groups (P < 0.01). RT-PCR results were consistent with those obtained by in situ hybridization.

CONCLUSION: The mRNA expression of RhoC in ESCC increases significantly and is closely correlated with tumor biological behavior, which suggests that RhoC overexpression is closed associated with the pathogenesis of ESCC. RhoC may be a new auxiliary parameter for early diagnosis and prognostic prediction for ESCC.

Identification of messenger RNA substrates for mouse T-STAR

Using the method of isolation of specific nucleic acids associated with proteins (SNAAP), we have identified 10 candidate target mRNA substrates bound by mT-STAR (mouse T-STAR protein) from testis extract. Among them, our study focused on Fabp9, a gene that is essential for male gametogenesis, and showed that mT-STAR could directly bind to Fabp9 mRNAs. The binding sites are in a short sequence of the coding region and 3' untranslated region of Fabp9 mRNA. These suggest that mT-STAR can regulate the metabolism and expression of Fabp9. In conclusion, identification of mT-STAR-bound mRNA substrates might help to illustrate the potential spectrum of the process and provide valuable insight into the biological function of this RNA-binding protein in spermatogenesis.

Reduction of islet pyruvate carboxylase activity might be related to the development of type 2 diabetes mellitus in Agouti-K mice

Pyruvate carboxylase (PC) activity is enhanced in the islets of obese rats, but it is reduced in the islets of type 2 diabetic rats, suggesting the importance of PC in beta-cell adaptation to insulin resistance as well as the possibility that PC reduction might lead to hyperglycemia. However, the causality is currently unknown. We used obese Agouti mice (AyL) as a model to show enhanced beta-cell adaptation, and type 2 diabetic db/db mice as a model to show severe beta-cell failure. After comparison of the two models, a less severe type 2 diabetic Agouti-K (AyK) mouse model was used to show the changes in islet PC activity during the development of type 2 diabetes mellitus (T2DM). AyK mice were separated into two groups: mildly (AyK-M, blood glucose <250 mg/dl) and severely (AyK-S, blood glucose >250 mg/dl) hyperglycemic. Islet PC activity, but not protein level, was increased 1.7-fold in AyK-M mice; in AyK-S mice, islet PC activity and protein level were reduced. All other changes including insulin secretion and islet morphology in AyK-M mice were similar to those observed in AyL mice, but they were worse in AyK-S mice where these parameters closely matched those in db/db mice. In 2-day treated islets, PC activity was inhibited by high glucose but not by palmitate. Our findings suggest that islet PC might play a role in the development of T2DM where reduction of PC activity might be a consequence of mild hyperglycemia and a cause for severe hyperglycemia.

Microbial population dynamics of granular aerobic sequencing batch reactors during start-up and steady state periods

This study investigates microbial population dynamics in granular sequencing batch reactors (GSBR). The experimental results of DGGE fingerprint of sludge demonstrated that the microbial community structure of sludge shifted significantly during granulation period and nutrient removal improvement period. After reactor performance and physical characteristics of sludge reached steady state, microbial population of sludge became relatively stable. The high similarity of microbial community structure between co-existed flocculated sludge and granular sludge in GSBR at different operation phases indicated that similar microbial consortium could exist in compact aggregated form or in amorphous flocculated form. Therefore, strong selection pressure was still required to wash out flocs to maintain the stability of reactor operation. In addition, it was found that substrate type had considerable impact on microbial species selection and enrichment in granular sludge. The clone library of granular sludge showed that microbial species in divisions of α-Proteobacteria, β-Proteobacteria, γ-Proteobacteria and Bacteroidetes existed within acetate-fed granule communities and Thauera spp. from β-Proteobacteria accounted for 49% of the total clones in the whole clone library. It is thus speculated that Thauera spp. are important for the formation of acetate-fed granules under the conditions used in this study, maintaining the integrity of granules or substrate degradation.

First Report of Citrus bent leaf viroid and Citrus dwarfing viroid from Citrus in Punjab, Pakistan

Pakistan is among the top 10 citrus-producing countries of the world and the leader in Kinnow mandarin production with production concentrated in the province of Punjab, which produces more than 96% of the total citrus crop. To evaluate the presence and distribution of citrus viroids in this area, 34 samples were collected in September 2008 from citrus orchards in the Sargodha, Bhalwal, and Faisalabad areas of Punjab, including 15 'Mosambi' and two 'Bloodred' sweet oranges (Citrus sinensis), eight 'Kinnow' and four 'Feutrell Early' mandarins (C. reticulata), three 'Jatti Khatti' rough lemon (C. jambhiri), and two grapefruit (C. paradisi), which showed stunting, bark scaling, and cracking symptoms on the rootstock which was either citrange (Poncirus trifoliata × C. sinensis) or sweet lime (C. limetta). Infected budwood from these trees was grafted onto indicator plants of Arizona 861-S-1 'Etrog citron' (C. medica) budded on rough lemon rootstock, and after 3 months, the citron showed typical viroid symptoms of mild epinasty and leaf roll with 23 of the 34 samples. A one-step multiplex reverse transcription (RT)-PCR assay (3) was used to detect simultaneously Citrus exocortis viroid (CEVd), Citrus bent leaf viroid (CBLVd), Hop stunt viroid (HSVd), Citrus dwarfing viroid (CDVd), and Citrus bark cracking viroid (CBCVd). On the basis of amplification of the appropriately sized DNA, CEVd, CBLVd, HSVd, and CDVd were detected in 12, 8, 31, and 17 samples, respectively, whereas CBCVd was not detected. Twenty-three of 34 infected samples harbored more than one viroid species and one had four viroids. Budwood from 11 trees did not induce viroid symptoms on Etrog citron. Two of these trees were infected with CBLVd only and nine with HSVd only. Four primer pairs were used to amplify the full sequences of CEVd, CBLVd, HSVd, and CDVd by RT-PCR (2), which were cloned by standard methods. Sequences of three cDNA clones each of CEVd (Nos. FJ773253, FJ773254, and FJ773255), CBLVd (Nos. FJ773262, FJ773263, and FJ773267), HSVd (Nos. FJ773268, FJ773269, and FJ773271), and CDVd (Nos. FJ773274, FJ773275, and FJ773276) were deposited in GenBank. BLAST analysis showed that these nucleotide sequences had greater than 97% nucleotide identity to the most similar genome sequences in GenBank. One of the HSVd sequences, FJ773271, presented the cachexia determinants. To our knowledge, this is the first report of CBLVd and CDVd in Pakistan (1). These results indicate the need for proper indexing of mother trees and a virus-free propagation scheme to create healthy budwood sources in Pakistan. References: (1) M. Arif et al. Pak. J. Bot. 37:407, 2005. (2) L. Bernard and N. Duran-Vila. Mol. Cell. Probes 20:105, 2006. (3) X. F. Wang et al. Eur. J. Plant. Pathol, 124:175, 2009.

Large-scale growth and characteristics of N-doped carbon nanotubes with ultra-large cavity

N-doped carbon nanotubes (CNTs) with ultra-large cavity have been synthesized by using a mixture of ZnO and graphite as catalyst in the floating catalyst method. The as-synthesized N-doped CNTs are very pure, and a striking characteristic structure is that the outer diameter is at least 10 times larger than the wall thickness. Moreover, electronic properties analysis reveals that the N-doped CNTs with ultra-large cavity have a reduced room temperature resistance compared with those of the common N-doped CNTs, which give an experimental prove for the previous theoretical predictions.

Mesenchymal Stem Cells Genetically Modified with the Angiopoietin-1 Gene Enhanced Arteriogenesis in a Porcine Model of Chronic Myocardial Ischaemia

The direct injection by thoracoscope of mesenchymal stem cells (MSCs) that had been genetically modified to express angiopoietin-1 was investigated in a porcine model to determine their effect on arteriogenesis and the effectiveness of this technique. Chronic myocardial ischaemia was established using a thoracoscope to insert an ameroid constrictor around the left circumflex coronary artery. Six weeks after establishing the ischaemia, 20 pigs were randomly divided into three groups to receive injections by thoracoscope of either genetically-modified MSCs, unmodified MSCs or phosphate-buffered saline into the ischaemic border area. The injections were repeated 1 month later. The genetically modified MSCs were found to restore blood flow significantly more than the other observed treatments and immunohistochemical evaluation of arteriogenesis supported this finding. In conclusion, the injection of MSCs that had been genetically modified to express angiopoietin-1 improved arteriogenesis and increased collateral blood flow in the myocardial ischaemic area. Thoracoscope delivery of the injection was safe and minimally invasive.

Constructing an array of anchored single-molecule rotors on gold surfaces

Molecular rotors with a fixed off-center rotation axis have been observed for single tetra-tert-butyl zinc phthalocyanine molecules on an Au(111) surface by a scanning tunneling microscope at LN2 temperature. Experiments and first-principles calculations reveal that we introduce gold adatoms at the surface as the stable contact of the molecule to the surface. An off-center rotation axis is formed by a chemical bonding between a nitrogen atom of the molecule and a gold adatom at the surface, which gives them a well-defined contact while the molecules can have rotation-favorable configurations. Furthermore, these single-molecule rotors self-assemble into large scale ordered arrays on Au(111) surfaces. A fixed rotation axis off center is an important step towards the eventual fabrication of molecular motors or generators.

First Report of Boll Rot of Cotton Caused by Pantoea agglomerans in China

Since the summer of 2006, bacterial boll rot of cotton has been observed on fruits of 'Xinluzao 31' (Xinluzao 6 × Acala) in Xinjiang Province. It resulted in as much as 20% yield loss in several fields. Symptoms do not appear on the outer carpel. In the infected cotton bolls, fibers do not mature completely and seed tissue exhibits brown necrotic coloration. Lint and seeds from 24 surface-disinfested cotton bolls were triturated and plated onto King's medium B (KB). Plates were incubated at 28°C for 48 h. Forty eight strains with yellow pigmentation on KB were characterized. All were nonfluorescent on KB, gram negative, facultatively anaerobic, unable to produce indole from tryptophan, able to reduce nitrate to nitrite, and produce acid from glucose, cellobiose, lactose, melibiose, and melonate. In addition, 16S rDNA in seven strains was amplified with universal primers (1). The PCR products were cloned into pGEM-T easy vector and sequenced. A BLAST search of the seven sequences against the GenBank nucleotide library indicated 100% identity with the 16S rDNA sequence of Enterobacter agglomerans strain A80. Then an additional primer pair, pagF and pagR (3), was used for more specific amplification of Pantoea agglomerans 16S rDNA, which resulted in single highly specific fragments of approximately 1 kb. On the basis of morphological, physiological, biochemical characteristics, and 16S rRNA gene sequence analysis, we identified the bacterium to be P. agglomerans. To confirm pathogenicity, cell suspensions (1 × 10⁸ CFU/ml) of eight representative strains were used to inoculate cotton at peak bolling stage in the field. Cell suspensions, or water as the control, were applied to stigma scars, wall sutures, and scratch wounds on bracts, calyxes, and bolls. Alternatively, a needle was used to puncture through a drop of suspension placed on the boll wall suture and bracts. At least 20 bolls or flowers were inoculated with each bacterial strain per inoculation method. Infection occurred only when bacterial injections breached the endocarp of the boll either through the carpel wall or a suture between carpel sections. Disease symptoms developed 1 week postinoculation. The inoculated organism was reisolated from the diseased tissues. P. agglomerans is generally regarded to be a soil saprophyte or leaf epiphyte, but strains can opportunistically infect plants triggering gall formations or human wounds causing septic arthritis. The disease symptoms and pathogen characteristics observed in this study are identical to those reported in the United States (2). To our knowledge, this is the first report of P. agglomerans causing boll rot of cotton in China. References: (1) S. Manulisi and I. Barash. Mol. Plant Pathol. 4:307, 2003. (2) E. G. Medrano et al. J. Appl. Microbiol. 103:436, 2007. (3) S. Vorwerk et al. Agric. For. Entomol. 9:57, 2007.

Expression of phosphatase of regenerating liver 1 and 3 mRNA in esophageal squamous cell carcinoma

CONTEXT

Phosphatase of regenerating liver (PRL) 3 messenger RNA (mRNA) was reported to express in human colorectal, gastric, ovarian, breast, and hepatic cancers.

OBJECTIVE

To examine the expression of PRL-1 and PRL-3 mRNAs in human esophageal squamous cell carcinoma (ESCC).

DESIGN

Expression of PRL-1 and PRL-3 mRNA was examined with reverse transcriptase-polymerase chain reaction in fresh tissue collected from 40 cases of ESCC with matched lymph node metastasis in 21 cases. The association of expression of PRL-1 and PRL-3 mRNAs with clinicopathologic parameters was analyzed.

RESULTS

The frequencies of PRL-1 and PRL-3 mRNA expression were significantly higher in ESCC than in normal esophageal tissue (P = .001; P = .01) and also significantly higher in ESCC with lymph node metastasis than in those without lymph node metastasis (P = .01; P = .03). The levels of PRL-1 and PRL-3 mRNA expression were significantly higher in ESCC with lymph node metastasis than in those without lymph node metastasis (P = .04; P = .04). The frequencies and levels of PRL-1 and PRL-3 mRNA expression were correlated with the later stages but not with tumor differentiation, tumor location in the esophagus, patient's sex, and age.

CONCLUSIONS

PRL-1 and PRL-3 mRNAs may be involved in and used to predict the metastasis of ESCC. The possibility of using PRL-1 and PRL-3 as the therapeutical target is also discussed.

Effects of three-dimensional electromagnetic structures on resistive-wall-mode stability of reversed field pinches

In this Letter, the linear stability of the resistive wall modes (RWMs) in toroidal geometry for a reversed field pinch (RFP) plasma is studied. Three computational models are used: the cylindrical code ETAW, the toroidal MHD code MARS-F, and the CarMa code, able to take fully into account the effects of a three-dimensional conducting structure which mimics the real shell geometry of a reversed field pinch experimental device. The computed mode growth rates generally agree with experimental data. The toroidal effects and the three-dimensional features of the shell, like gaps, allow a novel interpretation of the RWM spectrum in RFP's and remove its degeneracy. This shows the importance of making accurate modeling of conductors for the RWM predictions also in future devices such as ITER.

Temperature-related fitness costs of resistance to spinosad in the diamondback moth, Plutella xylostella (Lepidoptera: Plutelidae)

Fitness costs associated with resistance genes expressed in the absence of insecticides affect the evolution of insecticide resistance and the outcome of resistance management programmes. However, measurements of fitness costs may not be straightforward as they vary with environmental conditions. The diamondback moth, Plutella xylostella L. (Lepidoptera: Plutellidae), has developed resistance to spinosad, the first insecticide of the Naturalyte class, after only a few years of field application of this product. In this study, we compared the performance of two homogenous strains of P. xylostella, one susceptible (SS) and the other resistant (RR) to spinosad at an unfavourable, low natural temperature regime, a favourable median-fluctuating temperature regime and an unfavourable high-fluctuating temperature regime. The RR strain showed only marginal fitness cost at the median temperature regime. At the low temperature regime, the RR strain failed to produce any viable offspring, while the SS strain achieved positive population growth. At the high temperature regime, the RR strain showed a 33% decrease in intrinsic rate of increase compared to the SS strain. The results demonstrate that fitness costs of resistance to spinosad are temperature-dependent, increasing in scale at unfavourably low and high temperatures; costs were particularly high at low temperatures. Suggestions for designing effective management programmes are made to delay or avoid development of resistance to spinosad by P. xylostella under different temperature conditions.

The immunosuppressive and protective ability of glucose-regulated protein 78 for improvement of alloimmunity in beta cell transplantation

An insulinoma cell line, NIT-1, transfected with glucose-regulated protein 78 (GRP78) was established, namely NIT-GRP78, and used to study the immunosuppressive and protective ability of GRP78. In extended cytotoxic T lymphocyte (CTL) killing assay, NIT-1-primed lymphocytes were more cytotoxic in killing beta cells than NIT-GRP78-primed lymphocytes. Severe necrosis was observed only when the NIT-1-primed lymphocytes were cultured with NIT-1 beta cells, but not with NIT-GRP78 cells. In addition, an increase of interleukin (IL)-4 secretion from beta cell-primed splenocytes when GRP78 presence was observed in cytokine enzyme-linked immunosorbent assay (ELISA). Diabetic mice reached normoglycaemia promptly and gained weight after transplantation of either NIT-1 or NIT-GRP78 cells. However, the recipient mice transplanted with NIT-GRP78 cells lived much longer than those recipients transplanted with NIT-1 cells, which was due apparently to prolonged insulin production by the transplanted NIT-GRP78 cells. In fact, we observed a significant increase of insulin concentration after glucose stimulation of diabetic mice received NIT-GRP78 cells at day 7 post-transplantation. From the results we propose that GRP78 could have a dual function in both protecting NIT-1 cells from CTL-mediated lysis and stimulating a population of T helper 2 cells to down-regulate the immune response to the transplanted beta cells.

Local expression of TAP-1 and MHC-I molecules and their relationship in condyloma acuminatum

BACKGROUND

Condyloma acuminatum (CA), caused by human papillomavirus (HPV), is characterized by a variable clinical course that can include significant morbidity, frequent disease recurrence and occasional oncogenicity. Effective CD8+ T-cell-mediated clearance of HPV-infected cells may be defective in patients with CA, leading to recurrent disease and failure to suppress latent HPV reactivation. The pathogenesis responsible for CA and the persistence of latent HPV infection remain unknown.

OBJECTIVE

To determine whether expression of transporters associated with antigen processing 1 (TAP-1) and the major histocompatibility complex class I (MHC-I) is involved in HPV immune escape.

METHODS

In this present study, we compared 31 CA lesions with 30 normal prepuces by immunohistochemistry and reverse transcription PCR for their expressions of TAP-1 and MHC-I.

RESULTS

Expressions of TAP-1 and MHC-I were significantly reduced in CA tissue biopsies compared with normal prepuces. There was a statistically significant positive correlation between expressions of TAP-1 and MHC-I in CA lesions. Furthermore, we found that TAP-1 mRNA was significantly reduced in CA lesions compared with those in normal prepuces.

CONCLUSION

These results suggest that HPV may evade immune recognition by downregulating MHC-I cell surface expression via decreased TAP-1 levels.

Reduced critical rotation for resistive-wall mode stabilization in a near-axisymmetric configuration

Recent DIII-D experiments with reduced neutral beam torque and minimum nonaxisymmetric perturbations of the magnetic field show a significant reduction of the toroidal plasma rotation required for the stabilization of the resistive-wall mode (RWM) below the threshold values observed in experiments that apply nonaxisymmetric magnetic fields to slow the plasma rotation. A toroidal rotation frequency of less than 10 krad/s at the q=2 surface (measured with charge exchange recombination spectroscopy using C VI) corresponding to 0.3% of the inverse of the toroidal Alfvén time is sufficient to sustain the plasma pressure above the ideal MHD no-wall stability limit. The low-rotation threshold is found to be consistent with predictions by a kinetic model of RWM damping.

Growth and Structure of Carbon Nanotube Y-Junctions

The effect of a catalyst on the growth and structure of carbon nanotube Y-junctions (CNTYs) using chemical vapor deposition has been investigated. Cobalt-, magnesium-, and calcium-nitrates are utilized as precursors of catalysts Co, Mg, Ca, Co/Mg, Co/Ca, and Mg/Ca for CNTY synthesis. Experimental result shows that Co/Mg or Co/Ca can grow CNTYs with straight branches while Co, Mg, Ca, and Mg/Ca will not grow any CNTYs, indicating that only combinations of Co with Mg or Ca will facilitate the formation of CNTYs. In addition, the effect of the carbon source on the formation of CNTYs has also been studied. It is found that thiophene (C4H4S) can promote the formation of CNTYs, while other sources such as methane (CH4) and acetylene (C2H2) cannot. The result shows that both the catalyst and the carbon source substantially affect the formation of CNTYs.

Single-nucleotide polymorphism identification in the caprine myostatin gene

Polymerase chain reaction (PCR) products of MSTN gene amplified from 35 goats representing 17 Chinese indigenous goat breeds and five imported goat breeds were sequenced to identify the single-nucleotide polymorphisms (SNPs) of a 379-bp fragment including part of intron 2 and exon 3 of MSTN gene. A total of eight SNPs (A1980G, G1981C, A1982G, G1984T, A2121G, T2124C, G2174A and A2246G) were identified among the sequenced goats. The SNPs found are all located in intron 2 except for A2246G, which was a synonymous mutation in exon 3. Four haplotypes were sorted from these eight SNPs, of which, haplotype I (AGAGATGA) and haplotype II (GCGTGTAA) are the two main haplotypes with the frequency of 77.8% and 14.8% respectively. The SNPs found at positions 1980, 1981, 1982, 1984 and 2121 might be linked to inheritance completely.

Enhanced rat beta-cell proliferation in 60% pancreatectomized islets by increased glucose metabolic flux through pyruvate carboxylase pathway

Islet beta-cell proliferation is a very important component of beta-cell adaptation to insulin resistance and prevention of type 2 diabetes mellitus. However, we know little about the mechanisms of beta-cell proliferation. We now investigate the relationship between pyruvate carboxylase (PC) pathway activity and islet cell proliferation 5 days after 60% pancreatectomy (Px). Islet cell number, protein, and DNA content, indicators of beta-cell proliferation, were increased two- to threefold 5 days after Px. PC and pyruvate dehydrogenase (PDH) activities increased only approximately 1.3-fold; however, islet pyruvate content and malate release from isolated islet mitochondria were approximately threefold increased in Px islets. The latter is an indicator of pyruvate-malate cycle activity, indicating that most of the increased pyruvate was converted to oxaloacetate (OAA) through the PC pathway. The contents of OAA and malate, intermediates of the pyruvate-malate cycle, were also increased threefold. PDH and citrate content were only slightly increased. Importantly, the changes in cell proliferation parameters, glucose utilization, and oxidation and malate release were partially blocked by in vivo treatment with the PC inhibitor phenylacetic acid. Our results suggest that enhanced PC pathway in Px islets may have an important role in islet cell proliferation.

Novel concentration-killing curve method for estimation of bactericidal potency of antibiotics in an in vitro dynamic model

The bactericidal pharmacodynamics of antibiotics against Escherichia coli were analyzed by a concentration-killing curve (CKC) approach, and the novel parameters median bactericidal concentration (BC(50)) and bactericidal intensity (r) for bactericidal potency were proposed. By using the agar plate method, about 500 E. coli cells were inoculated onto Luria-Bertani plates containing a series of antibiotic concentrations, and after 24 h of incubation at 37 degrees C, all the viable colonies were enumerated. This resulted in a sigmoidal CKC that could be perfectly fitted (R(2) > 0.9) with the function N = N(0)/[1 + e(r(x - BC(50)))], where N is number of colonies surviving on each plate with an x series of concentrations of an antibiotic, and N(0) represents the meaningful inoculum size. Construction of the CKC method was based on the bactericidal effect of each antibiotic against the bacterial strain versus the concentration in two dimensions and may be a more valid, accurate, and reproducible method for estimating the bactericidal effect than the endpoint minimum bactericidal concentration (MBC) method. Mathematically, the CKC approach was point symmetrical toward its inflexion (BC(50), N(0)/2); thus, 2BC(50) could replace MBC. The parameter BC(1) can be defined as BC(50) + [ln(N(0) - 1)/r], which is the drug concentration at which only one colony survived and which is the least critical value of MBC in the CKC. The variate r, which determined the tangent slope on inflexion when N(0) was limited, could estimate the bactericidal intensity of an antibiotic. This verified that the CKC approach may be useful in studies with other classes of antibiotics and has considerable value as a tool for the accurate and proper administration of antibiotics.

Prostate cancer chemoprevention agents exhibit selective activity against early stage prostate cancer cells

Preclinical models for the identification of prostate cancer chemoprevention agents are lacking. Based upon the notion that clinically useful chemoprevention agents should exhibit selective activity against early stage disease, studies were undertaken to assess whether chemoprevention agents selectively inhibited the growth of early stage prostate cancer, as compared to late stage cancer. First, a series of cell and molecular studies were performed, which, when taken together, validated the use of a panel of prostate cell lines as a model of the different stages of carcinogenesis. Next, therapeutic responsiveness to ten different cytotoxic or chemoprevention agents was evaluated. Chemoprevention agents exhibited selective activity against normal and early transformed prostate tissue, whereas cytotoxic agents were non-specific. Selective activity against early versus advanced prostate cancer cells is identified as a potential screening method for chemoprevention agents.Prostate Cancer and Prostatic Diseases (2001) 4, 81-91

[Primary analysis and sequencing the hemolytic relative gene of Edwardsiella tarda]

Hemolysin is an important pathogenic agent of Edwardsiella tarda (ET). A fragment containing hemolytic gene, of which sequence is 4,264 bp, was cloned from ET-12 chromosome by shutgun method. It has no similarity to the hemolysin genes reported, of which 424 bp of open read frame (ORF) 3 has 68% similarity to the hemolysin regulatory gene of S. typhi (slyA). The subclone which has complete ORF3 was hemolytic, and the other of which Kanamycin gene was inserted in Pvu I of ORF3 was no hemolytic. It proved the gene was in chromosomes of ET-12 and the other ET strains by hybridization in situ and Southern blot. As recombination plasmid with the gene entered nonhemolytic ET by electroporation, no hemolytic phenomenon was observed. Conclusion was that the gene wasn't the hemolysin gene and was hemolytic relative gene.

AMPA-Induced suppression of oligodendroglial gene expression in neonatal rat brain

Oligodendroglia are susceptible to alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA)-mediated excitotoxicity. We hypothesized that analysis of oligodendroglial gene expression would provide a sensitive indicator of acute excitotoxic oligodendroglial injury in the immature brain. AMPA (2 nmol) was injected intracerebroventricularly in 7-day-old rats. Proteolipid protein and myelin basic protein encoding mRNAs were evaluated 24-48 h later by semi-quantitative reverse transcription-polymerase chain reaction assays. AMPA markedly suppressed brain tissue content of oligodendroglial mRNAs.

Enhanced expression of insulin receptor substrate-2 and activation of protein kinase B/Akt in regenerating pancreatic duct epithelium of 60 %-partial pancreatectomy rats

AIMS/HYPOTHESIS

Early compensatory mechanisms of regeneration following partial pancreatectomy involve ductal proliferation and, subsequently, differentiation into acinar and endocrine cell types, although it is not clear how these processes are regulated. We investigated the expression and roles of insulin receptor substrate-2 (IRS-2) and protein kinase B/Akt (Akt) in pancreatic regeneration that starts with the common duct epithelium using a non-diabetic model of beta cell adaptation and mass expansion, 60 %-pancreatectomy rats.

METHODS

We used confocal immunofluorescence microscopy to study IRS-2 and Akt expression and activation in pancreatic common ducts at intervals after surgery. These proteins were studied in relation to proliferation markers and insulin immunostaining.

RESULTS

In pancreatectomized rats, a short-term increase in proliferation was observed in the common duct epithelial lining ( approximately 4-fold) compared with sham-operated control rats which correlated with about a 1.8-fold increase in IRS-2 immunoreactivity 2 days after surgery. Interspersed with proliferating cells of the common duct, evaginations were rare single and clustered insulin immunopositive cells which expressed high levels of IRS-2 immunoreactivity. Epithelium of duct evaginations from 2-day post-Px rats exhibited striking phospho-Akt staining ( approximately 3.5-fold above control rats) without any detectable changes in total Akt staining.

CONCLUSION/INTERPRETATION

Our data suggest that IRS-2 plays an important role in pancreatic regeneration and growth by mediating duct proliferation and by maintaining the differentiated beta cell. The restricted staining pattern of phospho-Akt to cells of the common duct evaginations suggests that it has a role in regulating post-mitotic events related to cell-specific gene expression or survival or both.

[A comparison of chemical composition and bioactivity of polypeptides from velvet antlers of Cervus nippon Temminck and Cervus elaphus Linnaeus]

OBJECTIVE

To compare the chemical composition and bioactivity of polypeptides(PPs) isolated from velvet antlers of sika deer (Cervus nippon Temminck) and red deer (Cervus elaphus Linnaeus).

METHOD

The two kind of polypeptides were isolated from the above mentioned velvet antlers with same technology. The chemical composition was determined using sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and MALDI-TOF mass spectrometry. Stimulant activity of cells proliferation was measured by [3H] TdR incorporation into DNA.

RESULT

The graphs of SDS-PAGE and MALDI-TOF MS of velvet antler polypeptides (VAPPs) from Chinese and New zealand red deer were very similar, but there were obvious difference in respect of graph between sika deer and red deer. VAPPs 25-50 mg.L-1 showed marked proliferation-promoting activity for rabbit costed chondrocytes, either sika deer or red deer. However, the activity of sika deer VAPPs 12.5 mg.L-1 for epidermal cells was weaker than that of red deer (12.5 mg.L-1).

CONCLUSION

The chemical property and bioactivity of VAPPs from sika deer and red deer are significantly different.

[Direct optical resolution of the enantiomers of biphenyl compounds by high performance liquid chromatography on amylose tris-(3,5-dimethylphenylcarbamate) stationary phase]

A chiral stationary phase(CSP) was prepared by coating amylose tris-(3,5-dimethylphenylcarbamate) onto aminopropylated spherical silica gel. The enantioselective chromatographic separation of a series of biphenyl compounds with antihepatitis activity was performed for the first time on CSP. The effect of alcohol modifiers in mobile phase was investigated. The mobile phases used in the study were hexane modified by ethanol, 1-propanol, 1-butanol or 2-propanol. It was found that the retention times and the separation of the enantiomers of biphenyl compounds on the CSP were dramatically influenced by the nature of alcohols in the mobile phase, and the best alcohol modifier for some compounds was ethanol. The interaction between the stationary phase and samples was also discussed.

Increased islet DNA synthesis and glucose-derived lipid and amino acid production in association with beta-cell hyperproliferation in normoglycaemic 60 % pancreatectomy rats

AIMS/HYPOTHESIS

Glycaemia does not change following a 60 % pancreatectomy in rats because of enhanced beta-cell function and proliferation (so-called beta-cell adaptation). We previously studied these rats 4 weeks after surgery and showed hypersensitization of glucose-induced insulin secretion because of increased glucokinase activity. In this study of 60 % pancreatectomy rats 5 days after surgery, when beta-cell proliferation increased threefold, we investigated whether increases in glucose metabolism enhance the production of glucose-derived lipid, amino acids and DNA.

METHODS

Isolated islets from 60 % pancreatectomy and sham-operated control rats 5 days or 4 weeks after surgery were studied.

RESULTS

Five days after 60 % pancreatectomy surgery, islet glucose phosphorylation increased threefold, but overall glucose usage increased only twofold. The glucose-6-phosphate (G6P) concentration thus doubled, resulting in a sixfold increase in G6P metabolism through the pentose phosphate shunt (PPS). The pentose phosphate shunt generates ribose-5-phosphate for nucleotide synthesis, and DNA synthesis doubled in the partial pancreatectomy islets. In contrast, partial pancreatectomy rats 4 weeks after surgery had a smaller increase in glucokinase activity and their islet glucose-6-phosphate concentration and pentose phosphate shunt activity were equal to that of the control rats. DNA synthesis and beta-cell proliferation, based on BrdU incorporation were close to normal. Another consequence of the heightened glucose metabolism in the 5-day partial pancreatectomy islets was twofold increase in production of glucose-derived lipid and the amino acids, alanine and glutamate.

CONCLUSIONS/INTERPRETATION

The enhanced glucokinase activity in 60 % pancreatectomy rats supports the compensatory beta-cell hyperproliferation by increasing production of glucose-derived DNA, lipids and amino acids.

[Clinical study on effect of recombinant roasted licorice decoction combined with low-dose glucocorticoids in treating idiopathic thrombocytopenic purpura]

OBJECTIVE

To explore the clinical effect of recombinant roasted licorice decoction (RRLD) combined with low-dose glucocorticoids (GC) in treating idiopathic thrombocytopenic purpura (ITP).

METHODS

Forty-three patients were divided semi-randomly into the treated group (n = 21) and the control group (n = 22), the former was treated with RRLD plus low-dose GC, and the latter was treated mainly with normal dosage of GC.

RESULTS

The total effective rate of the treated group was better than that of the control group, the difference between these two groups was significant (P < 0.05). After treatment the platelet count in the treated group arose from (36.29 +/- 9.70) x 10(9)/L to (95.14 +/- 18.26) x 10(9)/L, while in the control group from (37.31 +/- 9.29) x 10(9)/L to (77.73 +/- 21.96) x 10(9)/L, the RRLD was superior to nat of GC in raising platelet count, the difference between them was also significant (P < 0.01). The treated group was lower obviously than the control group in adverse reaction (P < 0.01).

CONCLUSION

The efficacy of RRLD plus low-dose GC is reliable in treating ITP, with less adverse reaction.

[Direct optical resolution of acidic biphenyl drugs by high performance liquid chromatography on tris(3,5-dimethylphenylcarbamate) of cellulose]

A chiral stationary phase was prepared by coating cellulose-tris(3, 5-dimethylphenylcarbamate) onto aminopropylated silica gel. A series of enantiomeric acidic biphenyl drugs were directly resolved on the chiral stationary phase (CSP) by normal-phase high performance liquid chromatography (HPLC). A hexane-2-propanol eluting system containing 1% of trifluoroacetic acid was used as mobile phase. Efficient optical resolution of the acidic biphenyl drugs has been attained. The factors that influence chiral discrimination such as structural characeristic of the samples and mobile phase were investigated. An interaction model between the stationary phase and the samples was discussed. The results showed that efficient optical resolution of racemic carboxylic acids could be attained by normal-phase HPLC on CSP using a hexane-2-propanol eluting system containing 1% of trifluoroacetic acid.

beta-cell adaptation in 60% pancreatectomy rats that preserves normoinsulinemia and normoglycemia

Islet beta-cells are the regulatory element of the glucose homeostasis system. When functioning normally, they precisely counterbalance changes in insulin sensitivity or beta-cell mass to preserve normoglycemia. This understanding seems counter to the dogma that beta-cells are regulated by glycemia. We studied 60% pancreatectomy rats (Px) 4 wk postsurgery to elucidate the beta-cell adaptive mechanisms. Nonfasting glycemia and insulinemia were identical in Px and sham-operated controls. There was partial regeneration of the excised beta-cells in the Px rats, but it was limited in scope, with the pancreas beta-cell mass reaching 55% of the shams (40% increase from the time of surgery). More consequential was a heightened glucose responsiveness of Px islets so that glucose utilization and insulin secretion per milligram of islet protein were both 80% augmented at normal levels of glycemia. Investigation of the biochemical basis showed a doubled glucokinase maximal velocity in Px islets, with no change in the glucokinase protein concentration after adjustment for the different beta-cell mass in Px and sham islets. Hexokinase activity measured in islet extracts was also minimally increased, but the glucose 6-phosphate concentration and basal glucose usage of Px islets were not different from those in islets from sham-operated rats. The dominant beta-cell adaptive response in the 60% Px rats was an increased catalytic activity of glucokinase. The remaining beta-cells thus sense, and respond to, perceived hyperglycemia despite glycemia actually being normal. beta-Cell mass and insulin secretion are both augmented so that whole pancreas insulin output, and consequently glycemia, are maintained at normal levels.

Active feedback stabilization of toroidal external modes in tokamaks

Active feedback stabilization of pressure-driven modes in tokamaks is investigated by toroidal computations. Typically, the feedback does not strongly modify the plasma-generated magnetic field perturbation. Feedback with modest gain and a single coil array poloidally stabilizes substantially for a range of coil shapes. Optimum design uses narrow sensor coils not too far from the plasma and rather wide feedback coils, which may be outside the resistive wall. Complex gain, which makes the mode rotate, can decrease the gain required for stabilization, but real gain is more robust.

Glucose-fatty acid cycle to inhibit glucose utilization and oxidation is not operative in fatty acid-cultured islets

The glucose-fatty acid cycle of Randle entails two elements: decreased pyruvate dehydrogenase (PDH) activity, which inhibits glucose oxidation, and inhibition of phosphofructokinase (PFK) by a rise in citrate so that glucose-6-phosphate (G-6-P) levels increase, thereby inhibiting hexokinase activity and hence glucose utilization. Chronic exposure of islets to long-chain fatty acids (FA) is reported to lower PDH activity, but the effect on glucose oxidation and glucose-induced insulin secretion is uncertain. We investigated rat islets that were cultured for 4 days with 0.25 mmol/l oleate/5.5 mmol/l glucose. Glucose oxidation was doubled at 2.8 mmol/l glucose and unchanged at 27.7 mmol/l glucose in the FA-cultured islets despite a 35% decrease in assayed PDH activity. Pyruvate content was increased 60%, which may well compensate for the decreased PDH activity and maintain flux through the citric acid cycle. However, a greater diversion of pyruvate metabolism through the pyruvate-malate shuttle is suggested by unchanged pyruvate carboxylase Vmax and a fourfold higher release of malate from isolated mitochondria. The FA-cultured islets also showed increased basal glucose usage and insulin secretion together with a lowered level of G-6-P and 50% reductions in citrate synthase Vmax and the citrate content. Thus, the effects of chronic FA exposure on islet glucose metabolism differ from the glucose-fatty acid interactions reported in some other tissues.

Velvet antler polypeptides promoted proliferation of chondrocytes and osteoblast precursors and fracture healing

AIM

To study the effects of velvet antler (VA) total polypeptides (VATP) and VA polypeptides, VAP-A, VAP-B, and VAP-C on proliferation of chondrocytes and osteoblast precusors.

METHODS

Chondrocytes (rabbit and human fetus) and osteoblast precusors (chick embryo) were incubated in the culture medium containing VATP or VAP-A, VAP-B, and VAP-C. [3H]TdR incorporation into DNA was measured. Fracture healing-promoting action of VATP was determined in rats.

RESULTS

VATP 50-200 mg.L-1 and VAP-B 12.5, 25, and 50 mg.L-1 showed most marked proliferation-promoting activity for rabbit costed chondrocytes and increased incorporation of [3H]TdR from (73 +/- 9) Bq (control group) to (272 +/- 55), (327 +/- 38), and (415 +/- 32) Bq, respectively (P < 0.01). The activity of VAP-A was weaker than that of VAP-B, and VAP-C had no activity. VATP 10 and 20 mg.kg-1 by local injection into the cross-section fracture area accelerated healing of radial fracture. The healing rate of VATP-treated group was higher (75%) than that of control group (25%) (P < 0.05).

CONCLUSION

VATP accelerated fracture healing by stimulating proliferation of chondrocytes and osteoblast precursors.

Effects of dexamethasone, cyproheptadine, anisodamine, and dinoprostone on TNF alpha production in endotoxic shock

AIM

To study the effects of dexamethasone (Dex), cyproheptadine (Cyp), anisodamine (Ani), and dinoprostone (Din) on lipopolysaccharides (LPS)-induced tumor necrosis factor alpha (TNF alpha) gene expression and antishock effects of inhibiting TNF alpha production.

METHODS

Endotoxic shock in rats was produced by i.v. injection of LPS (E coli O111B4, 5 mg.kg-1). TNF alpha mRNA accumulation was assessed by Northern blot. Plasma TNF alpha contents were determined by radioimmunoassay.

RESULTS

The TNF alpha mRNA levels in rat liver at 2 h after LPS challenge was increased obviously (autoradiograms analyzed by scanning were 38 +/- 10 vs saline control 11 +/- 8, P < 0.01). The plasma TNF alpha contents were markedly increased [(22 +/- 3) micrograms.L-1 vs saline control (2.2 +/- 1.0) micrograms.L-1, P < 0.01]. Dex 5, Cyp 5, Ani 10, or Din 2 mg.kg-1 immediately injected after i.v. LPS markedly decreased the TNF alpha mRNA levels in rat liver and plasma TNF alpha contents. The Dex, Cyp, Ani, and Din improved the mouse survival rate 24 h after LPS 20 mg.kg-1 challenge.

CONCLUSION

Dex, Cyp, Ani, and Din strongly inhibit LPS-induced TNF alpha gene expression, and have a beneficial antishock effects.

Triterpenoid saponins from Ilex latifolia

Three new triterpenoid saponins, latifolosides F, G, H were isolated from the leaves of Ilex latifolia. Their structures were elucidated on the basis of chemical and spectral evidence. Latifoloside F was determined to be 3-O-[alpha-L-rhamnopyranosyl(1-2)]-[beta-D-glucopyranosyl(1-3)-]- alpha-L-arabinopyranosyl ilexgenin B 28-O-[alpha-L-rhamnopyranosyl(1-2)]-beta-D-glucopyranoside. Latifoloside G was 3-O-[alpha-L-rhamnopyranosyl(1-2)]-[beta-D-glucopyranosyl(1-3)-]- alpha-L-arabinopyranosyl pomolic acid 28-O-[alpha-L-rhamnopyranosyl(1-2)]-beta-D-glucopyranoside. Latifolioside H(3) was 3-O-[alpha-L-rhamnopyranosyl(1-2)]-[beta-D-glucopyranosyl(1-3)-]- alpha-L-arabinopyranosyl siaresinolic acid 28-O-[alpha-L-rhamnopyranosyl(1-2)]-beta-D-glucopyranoside.

Shared biochemical properties of glucotoxicity and lipotoxicity in islets decrease citrate synthase activity and increase phosphofructokinase activity

Diabetic states are characterized by a raised serum/islet level of triglycerides and a lowered EC50 (concentration at half-maximal stimulation) for glucose-induced insulin secretion. Culturing islets with long-chain fatty acids (FAs) replicates the basal insulin hypersecretion. In a previous study, we showed that the mechanism involved deinhibition of hexokinase by a 60% decrease in glucose-6-phosphate (G-6-P). The key event was proposed to be an increased phosphofructokinase (PFK) Vmax secondary to an upregulatory effect of the FA metabolite, long-chain acyl-coenzyme A (LC-CoA). We now show another contributory factor, a lowered content of the PFK inhibitor citrate. Citrate synthase Vmax and citrate levels were lowered 45% in rat islets cultured with 250 micromol/l oleate for 24 h. Both effects were reversed by triacsin C, an inhibitor of fatty acyl-CoA synthetase, the enzyme that generates LC-CoA. Culturing islets with high doses of glucose (16.7 mmol/l) for 48 h should also raise cytosolic LC-CoA. As predicted, citrate synthase Vmax was lowered and PFK Vmax was increased, both in a triacsin C-reversible fashion. These results show shared selected functional and biochemical properties in beta-cells of so-called glucotoxicity and lipotoxicity.

Growth inhibition of chronic myelogenous leukemia cells by ODN-1, an aptameric inhibitor of p210bcr-abl tyrosine kinase activity

p210bcr-abl-Related tyrosine kinase activity has been shown to cause chronic myelogenous leukemia (CML), a disease of bone marrow stem cells. Having previously demonstrated that the aptameric oligonucleotide, ODN-1, could inhibit p210bcr-abl kinase activity, the current study sought to determine if ODN-1 could selectively inhibit the growth of CML cells relative to that of normal bone marrow. ODN-1, when introduced by electroporation into peripheral blood mononuclear cells (PBMC) from patients with CML, decreased the number of committed progenitors (CML CFU-GM) by an average of 67%+/-19% (mean+/-SEM, range 28-98%). Treatment of CML PBMC with ODN-1 was also shown to decrease the number of more primitive cobblestone area-forming cells (CAFC) by 35%-87%. In contrast, there was little suppressive effect by the combination of electroporation and ODN-1 on either CFU-GM or CAFC numbers from normal donor bone marrow. These studies suggest that inhibition of p210bcr-abl protein-tyrosine kinase (PTK) activity by ODN-1 is associated with some degree of selective growth inhibition of p210bcr-abl-transformed cells. p210bcr-abl kinase inhibitory agents may be useful for the ex vivo purging of bone marrow or peripheral blood progenitor/stem cells in the setting of autologous transplantation for CML.

[Progress on the study of neurochemical mechanisms of learning and memory]

Brain function research is one of the most important projects in biological sciences. Learning and memory is one of the most advanced functions in brain. This article reviewed the effects of some neurotransmitters and neuroactive peptides on learning and memory in an attempt to stimulate the research aiming at improving learning and memory.

Fatty acid-induced beta cell hypersensitivity to glucose. Increased phosphofructokinase activity and lowered glucose-6-phosphate content

Diabetic states are characterized by a raised serum/islet level of long chain fatty acids and a lowered ED50 for glucose-induced insulin secretion. Prolonged culture (> 6 h) of islets with long chain fatty acids replicates the basal insulin hypersecretion. We examined this effect in rat islets cultured for 24 h with 0.25 mM oleate. Insulin secretion at 2.8 mM glucose was doubled in combination with a 60% lowered islet content of glucose-6-phosphate (G6P). Investigation of the lowered G6P showed: (a) increased glucose usage from 0.5 to 100 mM glucose with identical values measured by [2-3H]glucose and [5-3H]glucose, (c) indicating little glucose- 6-phosphatase activity, (b) unchanged low pentose phosphate shunt activity, (c) 50% increased phosphofructokinase (PFK) Vmax, (d) a normal ATP/ADP ratio, and (e) unchanged fructose 2,6 bisphosphate content. Triacsin C, an inhibitor of fatty acyl-CoA synthetase, prevented the increase in PFK activity and the lowered G6P content. These results suggest that long chain acyl-CoA mediates the rise in PFK activity, which in turn lowers the G6P level. We speculate that the inhibition of hexokinase by G6P is thus attenuated, thereby causing the basal insulin hypersecretion.

Active antitumor immunotherapy, with or without B7-mediated costimulation, increases tumor progression in an immunogenic murine T cell lymphoma model

BW-Sp3 is a BW-5147-derived T cell lymphoma with limited immunogenicity since, despite regression of the majority of subcutaneous tumors, an important fraction of the animals will die from metastases. In the present study, the BW-Sp3 cells were transfected with genes encoding B7-1 or B7-2, known to be involved in the induction of T cell responses. The resulting transfectants exhibited a reduced tumorigenicity and did not cause mortality in the syngeneic recipients. Furthermore, immunization with the B7-1 or B7-2 transfectants resulted in an increased generation of cytotoxic T lymphocytes (CTL) that lysed both the transfectants and the wild-type BW-Sp3 cells. Since the B7 transfectants were completely rejected in syngeneic recipients and induced potent CTL recognizing the wild-type BW-Sp3 cells, these engineered cells were considered as candidates for immunotherapy. Vaccinations with the B7-1 or B7-2 transfectants could completely protect the animals from metastatic disease when subsequently challenged with wild-type BW-Sp3 cells. Furthermore, immunization with the B7 transfectants could prolong the survival time of mice that had been challenged intravenously with BW-Sp3 cells. Surprisingly, however, when these transfectants, as well as the wild-type BW-Sp3 cells, were used for vaccination of tumor-bearing animals, the presence of the subcutaneous BW-Sp3 tumors clearly interfered with the outcome of immunotherapy, resulting in increased malignancy, as reflected by a higher incidence of progressing tumors and a reduced survival rate. Possible implications for immunotherapy in humans are discussed.

A genome-based resource for molecular cardiovascular medicine: toward a compendium of cardiovascular genes

BACKGROUND

Large-scale partial sequencing of cDNA libraries to generate expressed sequence tags (ESTs) is an effective means of discovering novel genes and characterizing transcription patterns in different tissues. To catalogue the identities and expression levels of genes in the cardiovascular system, we initiated large-scale sequencing and analysis of human cardiac cDNA libraries.

METHODS AND RESULTS

Using automated DNA sequencing, we generated 43,285 ESTs from human heart cDNA libraries. An additional 41,619 ESTs were retrieved from public databases, for a total of 84,904 ESTs representing more than 26 million nucleotides of raw cDNA sequence data from 13 independent cardiovascular system-based cDNA libraries. Of these, 55% matched to known genes in the Genbank/EMBL/DDBJ databases, 33% matched only to other ESTs, and 12% did not match to any known sequences (designated cardiovascular system-based ESTs, or CVbESTs). ESTs that matched to known genes were classified according to function, allowing for detection of differences in general transcription patterns between various tissues and developmental stages of the cardiovascular system. In silico Northern analysis of known gene matches identified widely expressed cardiovascular genes as well as genes putatively exhibiting greater tissue specificity or developmental stage specificity. More detailed analysis identified 48 genes potentially overexpressed in cardiac hypertrophy, at least 10 of which were previously documented as differentially expressed. Computer-based chromosomal localizations of 1048 cardiac ESTs were performed to further assist in the search for disease-related genes.

CONCLUSIONS

These data represent the most extensive compilation of cardiovascular gene expression information to date. They further demonstrate the untapped potential of genome research for investigating questions related to cardiovascular biology and represent a first-generation genome-based resource for molecular cardiovascular medicine.

Does the increase of 8-hydroxydeoxyguanosine lead to poor sperm quality?

Several studies have suggested a population-wide decline in the quality of human semen during the past three decades, but the mechanism remains unclear. It was proved that damage to the DNA of germ cells would lead to mutation, and 8-hydroxydeoxyguanosine (8-OHdG), one of the major products of oxidative damage to DNA, may serve as one of the important factors to affect the sperm quality. In the present paper, 67 semen samples were collected to analyze the sperm quality (density, sperm number, motility, normal head, etc.), and 8-OHdG was measured in DNA isolated from the same sperm samples. The results showed that a significant inverse correlation exists between 8-OHdG/dG(deoxyguanosine) and sperm density (r = -0.358, p = 0.004), and between 8-OHdG/dG and sperm number (r = -0.389, p = 0.01). The results indicate that endogenous oxidative DNA damage could affect sperm quality and subsequently increase the risk of genetic defects.