Coexistence of bistable multi-pulse chaotic motions with large amplitude vibrations in buckled sandwich plate under transverse and in-plane excitations

This paper researches the dynamic snap-through phenomena and the coexistence of the multi-pulse jumping chaotic dynamics in bistable equilibrium positions and the large amplitude nonlinear vibrations for a simply supported buckled 3D-kagome truss core sandwich rectangular plate under combined transverse and in-plane excitations based on the extended high-dimensional Melnikov method. According to the two-degree-of-freedom non-autonomous nonlinear dynamical system of the buckled truss core sandwich rectangular plate and the theory of normal form, it is found that some nonlinear terms have less effects on the nonlinear dynamic responses than other nonlinear terms. The extended high-dimensional Melnikov method is employed to investigate the dynamic snap-through phenomena and the bistable multi-pulse jumping chaotic vibrations around the upper-mode and the lower-mode for two different cases of buckling in the truss core sandwich rectangular plate. A numerical method is used to detect the bistable multi-pulse jumping chaotic vibrations around two stable equilibrium positions for the non-autonomous buckled truss core sandwich rectangular plate. The obtained theoretical and numerical results indicate that there exists the coexistence of the bistable multi-pulse jumping chaotic vibrations and the large amplitude nonlinear vibrations in the buckled truss core sandwich rectangular plate under combined transverse and in-plane excitations.

A new bilobalide isomer and two cis-coumaroylated flavonol glycosides from Ginkgo biloba leaves

A new bilobalide isomer (1), together with two flavonol glycosides (2, 3), have been isolated and elucidated from the extract of Ginkgo biloba leaves. Significantly, 1 was a new sesquiterpene lactone with two lactone ring groups, both 2 and 3 were two flavonol glycosides with a same cis-coumaroylated fragment. Their chemical structures were elucidated by NMR and MS spectroscopic date and the absolute configuration of 1 was specific established by Cu-Kα X-ray crystallographic analyses. However, 1-3 showed no obvious anti-platelet aggregation activity.

Formononetin recovered injured nerve functions by enhancing synaptic plasticity in ischemic stroke rats

BACKGROUND AND OBJECTIVES

Formononetin has protective effect against ischemic stroke. It's unclear whether it can restore the nerve functions after stroke.

METHODS

SD rats were subjected with middle cerebral artery occlusion (MCAO), and divided into sham, model and formononetin (30 mg/kg) groups. Neurobehavioral tests (modified Neurological Severity Score [mNSS] and rotarod) were performed before and at 1, 3, 7 and 14 days after MCAO. Then, the rats were sacrificed and the brain sections were processed for neuronal differentiation and synaptic plasticity.

RESULTS

Compared with the sham group, the scores of mNSS were significantly increased, and the residence time on the rotating drum was significantly decreased in the MCAO rats. Compared with the model group, the scores of mNSS were significantly decreased, and the residence time on the rotating drum was increased in the formononetin (30 mg/kg) group. Formononetin significantly increased the number of neuronal dendritic spines and the expression of β III-tubulin, GAP-43, NGF, BDNF, p-Trk A, p-Trk B, p-AKT and p-ERK 1/2.

CONCLUSIONS

Formononetin recovered injured nerve functions after ischemic stroke. PI3K/AKT/ERK pathway might involve in the beneficial effect of formononetin on the neuronal differentiation and synaptic plasticity.

[Effects of infant feeding practice on eczema during early childhood in Shanghai, Hohhot, and Fuzhou]

Objective: To estimate the prevalence of eczema in early childhood and effect of infant feeding practice on eczema by different regions of China with diverse climate and dietary patterns. Method: A questionnaire survey was conducted from June 2012 to October 2012 in Shanghai, Hohhot, and Fuzhou. The parent or guardian of the children aged between 2.5 to 3.5 years attending routine health visit in the chosen communities were invited to complete a modified questionnaire of the International Study of Asthma and Allergy in Childhood (ISAAC). Logistic regression model was used to analyze of the family history of allergy, duration of breastfeeding, timing of introduction of complementary foods and other potential confounders. Result: A total of 2 242 children were interviewed, 750 from Shanghai, 716 from Hohhot, and 776 from Fuzhou. The prevalence of eczema in early childhood was significantly different among Shanghai (16.9%, 95%CI 16.87-16.93), Hohhot (34.5%, 95%CI 34.46-34.54)and Fuzhou (44.3%, 95%CI 44.26-44.34). The difference was statistically significant between 3 groups (χ²=72.05, P<0.05). Introducing complementary food after the age of 6 months was associated with a decreased risk for eczema when compared to introduction between 4 to 6 months(odds ratio (OR) 0.58, 95%CI 0.41-0.81) in Fuzhou, while there was no significant association between timing of introduction of complementary foods and eczema in Shanghai and Hohhot. Conclusion: The prevalence of eczema during early childhood is various among three cities. The relationship between timing of introduction of complementary foods and eczema in Fuzhou is different from that in Shanghai and Hohhot. The role of climate and dietary patterns on prevalence of eczema needs further studies.

Simvastatin ameliorates graft-vs-host disease by regulating angiopoietin-1 and angiopoietin-2 in a murine model

Angiopoietins play an important role in vascular endothelial function. Endothelial damage is an important pathogenesis relating with acute graft-versus-host disease (GVHD) after allogeneic hematopoietic stem cell transplantation (allo-HSCT), protecting endothelial cells (ECs) from damage may be a potent prophylaxis and therapeutic strategy of acute GVHD (aGVHD). In this study, we explored changes in Angiopoietin-1 (Ang-1) and Ang-2 expression in a aGVHD mouse model and determined whether simvastatin prevents GVHD through regulating Ang-1 and Ang-2 expression. In vitro simvastatin administration increased Ang-1 production and release but conversely inhibited Ang-2 release from EA.hy926 ECs. Simvastatin improved the survival of aGVHD mice, attenuated the histopathological GVHD grades and plasma levels of Ang-2, and elevated the plasma levels of Ang-1 as well as the aortic endothelial levels of Ang-1 and Ang-2. In summary, simvastatin represents a novel approach to combat GVHD by increasing Ang-1 production while suppressing Ang-2 release to stabilize endothelial cells.

Antibody detection tests for early diagnosis in tuberculous meningitis

BACKGROUND

Tuberculous meningitis (TBM) is the most severe form of tuberculosis. Microbiological confirmation is rare and treatment is often delayed. Early diagnosis and immediate initiation of treatment are essential for effective TBM control. A systematic review was performed in this study to assess the diagnostic accuracy of detecting antibodies against Mycobacterium tuberculosis in the cerebrospinal fluid (CSF), according to standard methods. Test performance was summarized using a bivariate random-effects meta-analysis.

METHODS

Studies were identified by a search of the literature, up to July 25, 2015, in the EMBASE and MEDLINE databases via Ovid SP and PubMed. The Cochrane Library was also searched for original, peer-reviewed molecular epidemiology studies that reported the diagnosis of TBM based on antibody detection in the CSF.

RESULTS

Thirty-six articles (58 studies) were identified. The sensitivity of antibody detection was 0.75 (95% confidence interval (CI) 0.66-0.82), specificity was 0.98 (95% CI 0.96-0.99), and the area under the receiver operating characteristic curve (AUROC) was 0.97 (95% CI 0.95-0.98). By subgroup analysis, the detection of anti-M37Ra was the highest (AUROC 0.99, 95% CI 0.98-1.00), followed by anti-antigen 5 (AUROC 0.99, 95% CI 0.97-0.99) and anti-M37Rv (AUROC 0.97, 95% CI 0.95-0.98).

CONCLUSIONS

For the early diagnosis of TBM based on antibodies in the CSF, the detection of anti-M37Ra, anti-antigen 5, or anti-M37Rv provides the greatest sensitivity and specificity.

Endothelial microparticles carrying hedgehog-interacting protein induce continuous endothelial damage in the pathogenesis of acute graft-versus-host disease

Accumulating evidence suggests that endothelial microparticles (EMPs), a marker of endothelial damage, are elevated in acute graft-versus-host disease (aGVHD), and that endothelial damage is implicated in the pathogenesis of aGVHD, but the mechanisms remain elusive. In this study, we detected the plasma EMP levels and endothelial damage in patients and mice with aGVHD in vivo and then examined the effects of EMPs derived from injured endothelial cells (ECs) on endothelial damage and the role of hedgehog-interacting protein (HHIP) carried by EMPs in these effects in vitro. Our results showed that EMPs were persistently increased in the early posttransplantation phase in patients and mice with aGVHD. Meanwhile, endothelial damage was continuous in aGVHD mice, but was temporary in non-aGVHD mice after transplantation. In vitro, EMPs induced endothelial damage, including increased EC apoptosis, enhanced reactive oxygen species, decreased nitric oxide production and impaired angiogenic activity. Enhanced expression of HHIP, an antagonist for the Sonic hedgehog (SHH) signaling pathway, was observed in patients and mice with aGVHD and EMPs from injured ECs. The endothelial damage induced by EMPs was reversed when the HHIP incorporated into EMPs was silenced with an HHIP small interfering RNA or inhibited with the SHH pathway agonist, Smoothened agonist. This work supports a feasible vicious cycle in which EMPs generated during endothelial injury, in turn, aggravate endothelial damage by carrying HHIP into target ECs, contributing to the continuously deteriorating endothelial damage in the development of aGVHD. EMPs harboring HHIP would represent a potential therapeutic target for aGVHD.

[Enhancement of GA3 and EDTA on Lolium perenne to remediate Pb contaminated soil and its detoxification mechanism]

A pot experiment was conducted to study the effects of plant growth regulator GA3 and metal chelate EDTA on enhancing the remediation of Pb contaminated soil, and the detoxification mechanism of Lolium perenne grown on Pb contaminated soil at 250 and 500 mg · kg(-1). The results showed that cell wall deposition and vacuolar compartmentalization played important roles in the detoxification of Pb in L. perenne shoot. The addition of EDTA alone increased Pb concentration in plants and Pb proportions in soluble fraction and organelles fraction, and enhanced the toxicity of Pb to plant, leading to the significant reduction of the plant biomass (P < 0.05). Foliar spray of lower concentration of GA3 (1 μmol · L(-1) or 10 μmol · L(-1)) alone significantly increased Pb accumulation by L. perenne (P < 0.05), but Pb proportions in soluble and organelles fraction were decreased, which alleviated the adverse effects of Pb on plant, thus improving the growth of plants (P < 0.05), with 1 μmol · L(-1) GA3 being the most effective. In contract, the addition of 100 μmol · L(-1) GA3 decreased Pb concentration in L. perenne, but increased the proportions of Pb in soluble fraction and organelles fraction, resulting in the reduction of plant biomass. Lower concen- tration of GA3 might alleviate the adverse effects of Pb and/or EDTA on plant, since the biomass amounts in the different treatments were in order of GA3 alone of lower concentration > GA3 of lower concentration + EDTA > EDTA alone. The combination application of low concentration of GA3 and EDTA showed a synergistic effect on the Pb accumulation in L. perenne (P < 0.05). Especially, Pb concentration in shoot and Pb extraction efficiency reached 1250.6 mg · kg(-1) and 1.1%, respec- tively, under the treatment of EDTA + 1 μmol L(-1) GA3 on the Pb 500 mg · kg(-1) soil. Therefore, the application of 1 μmol · L(-1) GA3 along with EDTA appeared to be a potential approach for phytoremediation of Pb contaminated soil.

The complete mitochondrial genome of Taeniogonalos taihorina (Bischoff) (Hymenoptera: Trigonalyidae) reveals a novel gene rearrangement pattern in the Hymenoptera

The family Trigonalyidae is considered to be one of the most basal lineages in the suborder Apocrita of Hymenoptera. Here, we determine the first complete mitochondrial genome of the Trigonalyidae, from the species Taeniogonalos taihorina (Bischoff, 1914). This mitochondrial genome is 15,927bp long, with a high A+T-content of 84.60%. It contains all of the 37 typical animal mitochondrial genes and an A+T-rich region. The orders and directions of all genes are different from those of previously reported hymenopteran mitochondrial genomes. Eight tRNA genes, three protein-coding genes and the A+T-rich region were rearranged, with the dominant gene rearrangement events being translocation and local inversion. The arrangements of three tRNA clusters, trnY-trnM-trnI-trnQ, trnW-trnL2-trnC, and trnH-trnA-trnR-trnN-trnS-trnE-trnF, and the position of the cox1 gene, are novel to the Hymenoptera, even the insects. Six long intergenic spacers are present in the genome. The secondary structures of the RNA genes are normal, except for trnS2, in which the D-stem pairing is absent.

Highly stable sub-5 nm Sn₆O₄(OH)₄ nanocrystals with ultrahigh activity as advanced photocatalytic materials for photodegradation of methyl orange

Among numerous active photocatalytic materials, Sn-based oxide nanomaterials are promising photocatalytic materials in environmental protection measures such as water remediation due to their excellent physicochemical property. Research on photocatalytic nanomaterials for photodegradation of methyl orange (MO) so far has focused on TiO₂-based nanostructures; e.g., TiO₂-P25 is recognized to be the best commercial photocatalyst to date, rather than Sn-based oxide nanomaterials, in spite of their impressive acid- and alkali-resistant properties and high stability. Here, we demonstrate very high photocatalytic activity of highly stable sub-5 nm hydromarchite (Sn₆O₄(OH)₄) nanocrystals synthesized by a simple and environmentally friendly laser-based technique. These Sn₆O₄(OH)₄ nanocrystals exhibit ultrahigh photocatalytic performance for photodegradation of MO and their degradation efficiency is far superior to that of TiO₂-P25. The detailed investigations demonstrated that the great photocatalytic activity results from the ultrafine size and unique surface activity induced by the laser-based technique. Mass production of reactive species of hydroxyl radicals was detected in the experiments due to the appropriate bandgap of Sn₆O₄(OH)₄ nanocrystals. These findings actually open a door to applications of Sn-based oxide nanomaterials as advanced photocatalytic materials.

Rearrangement of the nad1 gene in Pristaulacus compressus (Spinola) (Hymenoptera: Evanioidea: Aulacidae) mitochondrial genome

The mitochondrial genome of the Pristaulacus compressus (Spinola, 1808) (Hymenoptera: Aulacidae) (GenBank accession No. KF500406) is reported in this study. This is the first sequenced mitochondrial genome from the family Aulacidae of the order Hymenoptera. The length of this mitochondrial genome is 15,563 bp with an A + T content of 84%, including 13 protein-coding, 2 rRNA and 22 tRNA gene, and an A + T-rich region (Table 1). Three tRNA and one protein-coding genes were rearranged in the P. compressus mitochondrial genome, in which, the trnY was inverted, while the trnQ was shuffled to the downstream of tRNA cluster trnI-trnQ-trnM. The trnS1 was translocated to the downstream of the A + T-rich region together with the protein-coding gene nad1. The gene arrangement pattern of this mitochondrial genome is new to the Hymenoptera. All protein-coding genes start with ATN start codon. Ten protein-coding genes stop with termination codon TAA, whereas one protein-coding gene uses incomplete stop codon TA and two use T. The A + T-region is located between rrnS and trnS1 with a length of 780 bp.

Characterization of the complete mitochondrial genome of the black cutworm Agrotis ipsilon (Lepidoptera: Noctuidae)

The complete mitochondrial genome of the black cutworm Agrotis ipsilon (Lepidoptera: Noctuidae) was determined (GenBank accession No. KF163965). The length of this mitochondrial genome is 15,377 bp with an A + T content of 82.5%. There are 37 typical animal mitochondrial genes, that is, 13 protein-coding, 2 rRNA and 22 tRNA gene and an A + T-rich region. The tRNA gene trnM was rearranged to the upstream of the trnI-trnQ-trnM cluster compared with the pupative ancestral arrangement of insects. All protein-coding genes start with ATN start codon except for the gene cox1, which uses CGA as in other lepidopteran species. Ten protein-coding genes stop with termination codon TAA, whereas three protein-coding gene use incomplete stop codon T. The A + T-region is located between rrnS and trnM with a length of 332 bp and A + T content of 94.88%.

Sequencing and characterization of the Monocellicampa pruni (Hymenoptera: Tenthredinidae) mitochondrial genome

The mitochondrial genome of the Monocellicampa pruni (Hymenoptera: Tenthredinidae) (GenBank accession No. JX566509) has been reported in this study. This is the first sequenced mitochondrial genome from the family Tenthredinidae of the order Hymenoptera. The sequenced region of this mitochondrial genome is 15,169 bp with an A + T content of 77.21%, including 13 protein-coding, 2 rRNA and 19 tRNA genes, and a partial region of the A + T-rich region. Three tRNA genes, i.e. trnI. trnQ and trnM, between the A + T-rich region and the nad2 gene were failed to sequence because of the present of PolyAT structure. The gene arrangement of the sequenced region was similar to the pupative ancestral arrangement of insects. There are two large non-coding regions located between trnC and trnY. trnF and nad5 with a length of 107 and 177 bp, respectively. All protein-coding genes start with ATN start codon. Eleven protein-coding genes stop with termination codon TAA, whereas one protein-coding gene uses incomplete stop codon TA and one uses T. All of the 22 tRNA genes have a typical cloverleaf structure except for the trnS1, in which, the D-stem pairings in the DHU arm are absent.

The first complete mitogenome for the superfamily Cossoidea of Lepidoptera: The seabuckthorn carpenter moth Eogystia hippophaecolus

We determined the first complete mitochondrial genome (mitogenome) for the superfamily Cossoidea of Lepidoptera from the seabuckthorn carpenter moth Eogystia hippophaecolus (GenBank accession No. KC831443). The length of this mitogenome is 15,431 bp with 37 typical animal mitochondrial genes and an A + T-rich region. The tRNA gene trnM was rearranged to the upstream of trnI-trnQ-trnM cluster compared with the pupative ancestral arrangement of insects. All protein-coding genes start with ATN start codon except for the gene cox1, which uses CGA as in other lepidopteran species. Eight protein-coding genes stop with termination codon TAA. One protein-coding gene uses incomplete stop codon TA and four use T. The A + T region is located between rrnS and trnM with a length of 317 bp and A + T content of 92.74%.

The complete mitogenome of the turnip moth Agrotis segetum (Lepidoptera: Noctuidae)

Abstract The complete mitochondrial genome (mitogenome) of the turnip moth Agrotis segetum (Lepidoptera: Noctuidae) was determined (GenBank accession No. KC894725). This is the first sequenced mitogenome from the subfamily Noctuinae of Noctuidae. The length of this mitogenome is 15,378 bp with a A+T content of 80.7%. There are 37 typical animal mitochondrial genes and a A+T-rich region. The tRNA gene trnM was the only rearranged gene compared with the pupative ancestral arrangement of insects. All protein-coding genes start with ATN start codon except for the gene cox1, which uses CGA as in other lepidopteran species. Ten protein-coding genes stop with termination codon TAA, whereas three protein-coding gene use incomplete stop codon T. The A+T-region is located between rrnS and trnM with a length of 332 bp and A+T content of 93.5%.

Complete mitogenome of the Argyrogramma agnata (Lepidoptera: Noctuidae)

We determined the complete mitochondrial genome (mitogenome) of the silver looper moth Argyrogramma agnata (Lepidoptera: Noctuidae) (GenBank accession no. KC414791). The length of this mitogenome is 15,261 bp. All the 37 typical animal mitochondrial genes were found. The tRNA gene trnM was rearranged to the upstream of trnI-trnQ-trnM cluster compared with the pupative ancestral arrangement of insects. All protein-coding genes start with ATN start codon except for the gene cox1, which uses CGA as in other lepidopteran species. Nine protein-coding genes stop with termination codon TAA. One protein-coding gene uses incomplete stop codon TA and three use T. The A+T region is located between rrnS and trnM with a length of 334 bp.

The complete mitochondrial genome of the summer fruit tortrix moth Adoxophyes orana (Lepidoptera: Tortricidae)

The complete mitochondrial genome of the summer fruit tortrix moth Adoxophyes orana (Lepdioptera: Tortricidae) was determined (GenBank accession No. JX872403). The genome is 15,343 bp long with 37 typical animal mitochondrial genes and an A+T-rich region. As in other sequenced mitochondrial genomes of Lepidoptera, trnM was rearranged to the upstream of trnI-trnQ-trnM cluster compared with the pupative ancestral arrangement of insects. All protein-coding genes start with ATN start codon except for the gene cox1, which uses CGA start codon as in other lepidopteran species. Eight protein-coding genes stop with termination codon TAA. Five protein-coding genes use incomplete stop codons T. The A+T-region is located between rrnS and trnM with a length of 331 bp. This is the fifth completely sequenced mitochondrial genome from the family Tortricidae.

The complete mitochondrial genome of the beet armyworm Spodoptera exigua (Hübner) (Lepodiptera: Noctuidae)

The complete mitochondrial genome of the beet armyworm Spodoptera exigua (Hübner) (Lepodiptera: Noctuidae) was determined (GenBank accession number JX316220). The genome is 15,365 bp long with 37 typical animal mitochondrial genes and an A+T-rich region. As in other sequenced mitochondrial genomes of Lepidoptera, trnM was rearranged to the upstream of trnI-trnQ-trnM cluster compared with the pupative ancestral arrangement of insects. All protein-coding genes start with ATN start codon except for the gene cox1, which uses CGA as in other lepidopteran species. Eight protein-coding genes stop with termination codon TAA. Five protein-coding genes use incomplete stop codons TA or T. The A+T-rich region is located between rrnS and trnM with a length of 331 bp. This is the third completely sequenced mitochondrial genome from the family Noctuidae of Lepidoptera.

Expression of beclin 1, an autophagy-related protein, in human cervical carcinoma and its clinical significance

PURPOSE

To investigate the impact of beclin 1 on prognosis of cervical cancer, we determined the expression of beclin 1 in cervical cancer, cervical intraepithelial neoplasia (CIN) and normal cervical tissues.

METHODS

A total of 122 cases of cervical cancer, 35 cases with CIN and 31 cases with uterine fibroids were collected at the Cancer Center of Sun Yat University to determine the expression of beclin 1.

RESULTS

Beclin 1 positive rate in normal cervical tissues, CIN tissues and cervical cancers was 83.9%, 74.3% and 53.3%, respectively, and it was significantly different between the three groups (p < 0.01). Beclin 1 expression was negatively correlated with cervical cancer differentiation, lymph node metastasis, recurrence and death (p < 0.05). The negative expression is the risk factor affecting overall survival (p < 0.05) and progression-free survival (PFS) (p < 0.05). Multivariate analysis showed that beclin 1 negative expression was an independent risk factor of PFS time.

CONCLUSIONS

Beclin 1 may play a role in the occurrence and development of cervical cancer. Beclin 1 positive expression in patients indicates a better prognosis.

[Effect of betulinic acid on inducing apoptosis of human multiple myeloma cell line RPMI-8226]

The aim of this study was to investigate the effect of betulinic acid on inducing apoptosis of human multiple myeloma RPMI-8226 cell line. The inhibitory effect of betulinic acid on proliferation and its inducing apoptosis effect, influence on cell cycle and induced morphological changes of RPMI-8226 were evaluated by MTT, flow cytometry Annexin-V/PI double staining, flow cytometry with PI staining and fluorescence microscopy with Hoechst33258 staining, respectively. The transcription level changes of bcl-xl gene and caspase 3 which are two kinds of apoptosis related protein gene were determined by RT-PCR. The results showed that within a certain range of concentration (0, 5, 10, 15, 20 microg/ml), IC50 of betulinic acid to RPMI-8226 at 24 hours was 10.156+/-0.659 microg/ml, while the IC50 at 48 hours was 5.434+/-0.212 microg/ml, and its inhibiting effect on proliferation of RPMI-8226 showed both time-and dose-dependent manners. Flow cytometry with Annexin-V/PI double staining revealed that apoptotic rate of RPMI-8226 cells increased as betulinic acid concentration increased. Flow cytometry with PI staining showed that the ratio of cells in G0/G1 phase increased, while it in S phase decreased, and ratio of cells at G2/M phase did not present a significant change. Morphological differences were typical and obvious between cells in treated and control groups under fluorescence microscope using Hoechst33258 staining. RT-PCR detection of caspase 3 gene indicated that its transcription level showed an increasing trend as the concentration of betulinic acid increased, while the bcl-xl showed the opposite trend. It is concluded that the betulinic acid can induce apoptosis of RPMI-8226 within a certain range of concentration in a time- and dose-dependent manners. This phenomenon may be related to the transcriptional level increase of caspase 3 gene and decrease of bcl-xl. Betulinic acid also affects G1/S in cell cycle which arrests cells at phase G0/G1.

[Mechanism of gambogic acid-induced apoptosis in Raji cells]

This study was purposed to explore the apoptotic effect of gambogic acid on Raji cells and the role of death inducer-obliterator 1 (DIO-1) in this process. Annexin V-fluorescein-isothiocyanate/propidium iodide was used to detect apoptosis of Raji cells. Western blot was used to determine the expressions of DIO-1, Bcl-xL, pro-caspase 3 and 2 activated subunits: P17 and P20. The subcellular localization of DIO-1 in untreated and treated Raji cells was checked by immunofluorescence and Hoechst 33258 double staining. The results showed that the Gambogic acid dose-dependently induced the apoptosis of Raji cells, downregulated the expression of Bcl-xL, upregulated the expressions of DIO-1 and pro-caspase 3, induced the cleavage of pro-caspase 3 and DIO nuclear translocation. It is concluded that gambogic acid induces the apoptosis of Raji cells through DIO-1 upregulation, nuclear translocation, Bcl-xL downregulation and caspase 3 activation.

Nestin expression in different tumours and its relevance to malignant grade

BACKGROUND

Nestin, an intermediate filament (IF) protein, is expressed in proliferating progenitor cells of developmental and regenerating tissues, and is identified as a neuroepithelial precursor cell marker. Recently, nestin was detected in some neoplasms such as glioma, ependymoma, melanoma, rhabdomyosarcoma, gastrointestinal stromal tumour (GIST), and testicular stromal tumour. Moreover, the expression intensity of nestin exhibited significant correlation with the malignant grade of glioma.

AIMS

To detect the expression of nestin in different tumours and to analyse the relationship between the expression of nestin and the malignant grade of the tumours.

METHODS

Formalin-fixed and paraffin-embedded surgical samples of neoplastic tissues were obtained from the Department of Pathology of Sun Yat-sen University. Histological analysis and immunohistochemical staining for nestin were performed. Histoscores were analysed by semi-quantitative evaluation.

RESULTS

Nestin was expressed predominantly in the cytoplasm of angiosarcoma, pancreatic adenocarcinoma and GIST samples, and some tumour cells expressed in the nucleus. There was a statistically significant difference between the histoscore of nestin in high malignant GIST (2.2366 (0.6920)) and that in low malignant GIST (1.3783 (0.4268)) (p = 0.003); and also between that in high malignant angiosarcoma (1.9188 (0.2069)) and that in low malignant angiosarcoma (0.6474 (0.3273)) (p = 0.000). Cavernous angioma did not express nestin. The histoscore of nestin in high malignant pancreatic adenocarcinoma (7/14) was 1.1767 (0.4676), and that in low malignant pancreatic adenocarcinoma (3/8) was 0.6577 (0.0056) (no significant difference, p = 0.112).

CONCLUSIONS

Results suggest that the expression of nestin may play an important role in the development of some neoplasms such as GIST and angiosarcoma.

[The role of stromal cell derived factor-1/CXCR4 biological axis in tumor metastasis of non-Hodgkin lymphoma]

OBJECTIVE

To study the expression of stromal cell derived factor-1 (SDF-1) and its receptor CXCR4 in non-Hodgkin lymphoma (NHL), and to investigate the role of this biological axis in tumor metastasis of NHL.

METHODS

Specimens of bone marrow were collected from 4 patients with NHL with bone marrow infiltration and 4 cases of NHL without bone marrow infiltration, and 4 patients with benign hepatopathy with normal myelogram. Lymphoma specimens were collected from 7 cases of NHL and 3 cases of reactive proliferative lymphadenitis. The level of SDF-1alpha mRNA in the stromal cells of bone marrow and lymph node were determined by RT-PCR. The CXCR4 expression on lymphoma cells freshly isolated from bone marrow and lymph node of the NHL patients were studied by flow cytometry. Transwell assay was performed, the upper chamber being added with suspension of cells newly isolated from lymph nodes or bone marrow undergoing co-incubation with ant-CXCR4 monoclonal antibody or not, and the lower chamber added with culture fluid with or without recombinant human SDF-1alpha (rhSDF-1alpha). The migration rate of the primary lymphoma cells towards rhSDF-1alpha was calculated.

RESULTS

The expression levels of CXCR4 on the lymphoma cells isolated from the bone marrow involved or not involved by NHL were both significantly higher than that of the mononuclear cells from normal bone marrow (both P < 0.01), whereas the CXCR4 expression level on the lymphoma cells from the lymph nodes of the NHL patients was also significantly higher than that of the mononuclear cells from the lymph nodes of reactive proliferative lymphadenitis (P < 0.01). The SDF-1alpha mRNA expression level in the stromal cells isolated from the bone marrow involved by NHL was significantly higher than those of the stromal cells of bone marrow not involved by NHL and the normal bone marrow (both P < 0.01). Moreover, the SDF-1alpha expression level in the lymph node stromal cells of all the NHL patients was also significantly higher than that of the patients with reactive proliferative lymphadenitis (P < 0.01). Transwell assay revealed that all three kinds of primary lymphoma cells migrated towards rhSDF-1alpha effectively, and this migration was markedly inhibited by the addition of anti-CXCR4 monoclonal antibody to the lymphoma cells (all P < 0.01).

CONCLUSION

SDF-1/CXCR4 axis plays a uniquely important biological role in mediating tumor metastasis of NHL.

[Effect of deguelin on expression of nup98 in K562 cells]

The study was purposed to investigate the effect of deguelin on expression of nucleoporin 98 (nup98) in leukemia K562 cells. MTT assay was used to assess the effects of deguelin on cell proliferation. FCM and RT-PCR were used to analyze the changes of nup98 mRNA and protein in K562 cells after treating with deguelin. The results showed that deguelin inhibited the proliferation of K562 cells in a time- and dose-dependent manner; mean fluorescence intensity of nup98 in blank group (34.22 +/- 1.63) was significantly higher than that in control group (2.83 +/- 0.02, P < 0.01), 10 nmol/L deguelin could significantly inhibit the expression of nup98 protein; 10 nmol/L could not inhibit the expression of nup98 mRNA, 20, 40, 80, 160 nmol/L deguelin could significantly inhibit the expression of nup98 mRNA in a dose-dependant manner. It is concluded that deguelin inhibits the proliferation of K562 cell through inhibiting the expression of nup98, and may be considered as a new target for therapy of acute leukemia.

[Deguelin regulates cell cycle and nuclear pore complex protein Nup98 and Nup88 in U937 cells in vitro]

OBJECTIVE

To investigate antitumor activity and molecular mechanism of deguelin to the human U937 leukaemia cells and to explore the mechanisms regulating cell cycle and nucleoporin 98 (Nup98) and nucleoporin 88 (Nup88) in vitro.

METHODS

The effects of deguelin on the growth of U937 cells were studied by MTT assay, and the cell cycle of U937 cells by a propidium iodide method. The localization of the nuclear pore complex protein Nup98 and Nup88 was checked by immunofluorescence and immunoelectron microscopy. The expressions of Nup98 and Nup88 in U937 cells were checked by flow cytometry (FCM) and Western blot respectively.

RESULTS

The proliferation of U937 cells was significantly inhibited in a time-dose dependent manner in deguelin-treated group with a 24 h IC50 value of 21.61 nmol/L and 36 h IC50 value of 17.07 nmol/L. U937 cells treated with deguelin showed reduction in the percentages of cells in G0/G1, whereas accumulation of cells in S and G2/M phase. The ratio of G1/G0 phase cells were 73.01%, 71.15%, 68.42%, 52.45%, 43.99% and 22.82%, and that of S phase cells were 17.18%, 16.30%, 18.09%, 27.56%, 31.21% and 46.85%, and that of G2/M phase cells were 9.75%, 12.31%, 13.09%, 18.99%, 24.83% and 27.79% at deguelin concentrations of 0, 5, 10, 20, 40, 80 nmol/L respectively. Nup88 and Nup98 were found on both the nuclear and cytoplasmic side of the U937 cells. The expression of Nup98 was up-regulated and Nup88 down-regulated in deguelin treated U937 cells.

CONCLUSION

Deguelin is able to inhibit the proliferation of U937 cells by regulating the cell cycle. The antitumor activity of deguelin was related to up-regulating the expression of Nup98 and down-regulating Nup88 protein.

A distinct strategy to generate high-affinity peptide binders to receptor tyrosine kinases

We describe a novel and general way of generating high affinity peptide (HAP) binders to receptor tyrosine kinases (RTKs), using a multi-step process comprising phage-display selection, identification of peptide pairs suitable for hetero-dimerization (non-competitive and synergistic) and chemical synthesis of heterodimers. Using this strategy, we generated HAPs with K(D)s below 1 nM for VEGF receptor-2 (VEGFR-2) and c-Met. VEGFR-2 HAPs bound significantly better (6- to 500-fold) than either of the individual peptides that were used for heterodimer synthesis. Most significantly, HAPs were much better (150- to 800-fold) competitors than monomers of the natural ligand (VEGF) in various competitive binding and functional assays. In addition, we also found the binding of HAPs to be less sensitive to serum than their component peptides. We believe that this method may be applied to any protein for generating high affinity peptide (HAP) binders.

Regulating expressions of cyclin D1, pRb, and anti-cancer effects of deguelin on human Burkitt's lymphoma Daudi cells in vitro

AIM

To investigate anticancer effects and molecular mechanism of deguelin on human Burkittos lymphoma Daudi cells in vitro and compare the cytotoxicities of deguelin on Daudi cells and human peripheral blood monocular cells (PBMC).

METHODS

The effects of deguelin on the growth of Daudi cells were studied by 3-(4, 5-dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium (MTT) assay. Apoptosis were detected through Hoechst 33258 staining and Annexin V/PI double-labeled cytometry. The effect of deguelin on the cell cycle of Daudi cells were studied by a propidium iodide method. The expressions of cyclin D1 and pRb were checked by Western blot.

RESULTS

The proliferation of Daudi cells were decreased in deguelin-treated group with a 24-h IC50 value of 51.55 nmol/L. Deguelin induced Daudi cells apoptosis was in a time- and dose-dependent manner. G0/G1 phase increased and S phase decreased in Daudi cells treated with deguelin. With deguelin 0, 5, 10, 20, and 40 nmol/L treatment for 24 h, G0/G1 phase increased from 37.34% to 56.56%, whereas S phase decreased from 37.72% to 21.36%. PBMC was less sensitive to the cytotoxic effect of deguelin than Daudi cells. The expression of cyclin D1 and pRb protein were decreased sharply in Daudi cells treated with deguelin.

CONCLUSION

Deguelin is able to inhibit the proliferation of Daudi cells by regulating the cell cycle that arrested cells at G0/G1 phase and inducing the cell apoptosis. Moreover, deguelin selectively induced apoptosis of Daudi cells with low toxicity in PBMC. The antitumor effects of deguelin were related to down-regulating the expression of cyclin D1 and pRb protein.

Loss of pesticides from agricultural fields in SE Norway--runoff through surface and drainage water

Loss of two pesticides with different mobility characteristics, bentazone (Koc approximately 34) and propiconazole (Koc approximately 1800), were studied at three agricultural fields (Askim, Bjørnebekk and Syverud) in SE Norway. A conservative tracer (Br) was used to follow the flow of water. The loss of pesticides varied among the fields, depending on hydrological characteristics and soil properties. The loss of pesticides was higher from two artificially levelled silty clay loam soils with poor aggregate stability (Askim and Bjørnebekk) compared to a loam/silt loam soil with increased content of organic carbon and better aggregate stability (Syverud). The total accumulated loss was <0.5% from all fields. The highest pesticide concentrations were measured at the first runoff episode after application for both the mobile (bentazone) and less mobile pesticide (propiconazole) in the surface runoff. In the drainage water, the peak for the less mobile pesticide coincided with the Br tracer, while the peak for mobile pesticide appeared earlier than the Br tracer. Rapid movement of water, particles and pesticides through soils indicate flow through macropores. Larger proportions (in percent of total applied) of both the mobile and the strongly sorbed pesticides were lost through the drainage as compared to the loss through surface runoff at Askim. Here, it is suggested that macropore flow contribute to the increased loss of pesticides through the drainage. At Syverud, high infiltration capacity reduces the amount of water available for surface runoff, and somewhat higher loss of the mobile pesticide was registered in the drainage compared to the surface runoff. For the strongly sorbed pesticide, however, propiconazole was neither detected in surface nor in drainage water at Syverud. Generally, there was a higher percentage loss of the mobile compared to the strongly sorbed pesticide in both surface and drainage water, which is in agreement with the pesticides mobility characteristics in soil. An exception was, however, the erodible soil Bjørnebekk, where a higher fraction of propiconazole was lost in the surface runoff compared to bentazone. Large amounts of sediment transport from the Bjørnebekk field probably contributed to enhanced transport of the strongly sorbed pesticide.

Prevalence of human papillomavirus in cervical cancer: a multicenter study in China

A large-scale epidemiologic survey on the prevalence of different types of human papillomavirus (HPV) in cervical cancer in China is indicated because of the implications for the development of diagnostic probes and vaccines against cervical cancer. A total of 809 cervical cancer specimens were collected from 5 regions in China including Shanghai, Guangzhou, Sichuan, Beijing and Hong Kong. HPV DNA was detected in 83.7% of the specimens. HPV-16 was present in 79.6%, HPV-18 in 7.5%, HPV-52 in 2.6% and HPV-58 in 3.8% of all HPV-positive specimens. The prevalences of HPV-16 and HPV-18 in Hong Kong were 61.7 and 14.8%, respectively, representing a lower HPV-16 and a higher HPV-18 proportion compared with the other regions. HPV-16 remained the most common HPV infection in both squamous cell carcinoma (SCC) and adenocarcinoma (AC). The proportion of HPV-18 infection was significantly higher in AC than in SCC.

Loss of heterozygosity and its correlation with clinical outcome and Epstein-Barr virus infection in nasopharyngeal carcinoma

Sixty-one human nasopharyngeal carcinomas (NPC) were examined by allelotype analysis for the purposes of detecting potential association between loss of heterozygosity (LOH), clinicopathological parameters and Epstein-Barr virus (EBV) infection. LOH was performed using 257 polymorphic markers on 22 chromosomes. High frequency LOH (> or = 60%) was observed on 12 chromosome arms including 1p, 2p, 2q, 3p, 3q, 5q, 9p. 9q, 11q, 13q, 14q and 17q, with the highest LOH frequency of 91% on 3p. Seventy-three loci presented LOH frequency > or = 30%; most of these loci clustered on 1p36 p34, 2p25-p24, 3p14-p21, 3p24-p26, 5q11-q14, 5q31-q33, 9p21-p23, 9q33-q34, 11q23-q25, 13q12 q14, 13q31-q33, 14q13-q11, 14q32 and 19q13. On 1p36-p34, 2p25-p24, 5q13-q11, 5q31-q33 and 19q13 are reported for the first time. LOH was correlated with specific clinicopathological parameters including tumor T-stage, N-stage, TNM-stage, tumor differentiation and serum antibody titers of IgA against virus capsid antigens (VCA) and early antigen (EA) of EBV in NPC (LOH frequency > or = 30%). Significantly high LOH frequency was observed on 9p21 (56%) and 19q13 (50%) in NPC with stage T3+T4, while significantly higher LOH frequency was observed on 12p11 (65%) in NPC with stage T1 + T2. Significantly higher LOHfrequency on 19q13 was also observed in NPC with advanced TNM-stage (III+IV). High fractional allelic loss (FAL) value and high antibody titers of EBV IgA/VCA and/or IgA/EA were significantly correlated with T3 + T4-stage, distant lymph node metastasis and advanced TNM-stage of NPC. We also found that NPC patients with high titers of IgA/VCA and IgA/EA showed high LOH frequency on 16q (48%) and 19q13 (48%). These results suggest that LOH on 9p21, l6q and 19q13 may be responsible for the aggressiveness and progression of NPC; there may be an interaction between allelic loss and EBV infection in the etiology of NPC. High frequency of LOH on 4q21 and 14q11-q12 were alsofound to be correlated with WHO type III NPC histopathology, suggesting that LOH on these regions may cause poor NPC differentiation. Our data also may be useful for the development of a NPC molecular staging system, a system which may augment the use of clinical pathological features in the diagnosis and prognosis of this disease.

P-glycoprotein expression in squamous cell carcinoma of the oral and maxillofacial region

OBJECTIVE

To investigate the mechanism of drug resistance in oral and maxillofacial carcinoma to chemotherapy.

MATERIALS AND METHODS

Forty cases of squamous carcinoma in the oral and maxillofacial region were examined for the multidrug resistance gene product P-glycoprotein using a monoclonal antibody, MRK16.

RESULT

P-glycoprotein was detected in 62.5% of all samples. P-glycoprotein expression was related to the chemotherapy and the differentiation of carcinoma. P-glycoprotein expression was higher in the post-chemotherapy group than in the non-chemotherapy group (P < 0.05). Well-differentiated tumors expressed P-glycoprotein more frequently (P < 0.05). P-glycoprotein expression was compared with clinical response to chemotherapy. The accuracy rate of prediction was 75%.

CONCLUSION

P-glycoprotein plays an important role in mechanism of drug resistance of squamous cell carcinoma in the oral and maxillofacial region.

A mycobacterial extracytoplasmic sigma factor involved in survival following heat shock and oxidative stress

Extracytoplasmic function (ECF) sigma factors are a heterogeneous group of alternative sigma factors that regulate gene expression in response to a variety of conditions, including stress. We previously characterized a mycobacterial ECF sigma factor, SigE, that contributes to survival following several distinct stresses. A gene encoding a closely related sigma factor, sigH, was cloned from Mycobacterium tuberculosis and Mycobacterium smegmatis. A single copy of this gene is present in these and other fast- and slow-growing mycobacteria, including M. fortuitum and M. avium. While the M. tuberculosis and M. smegmatis sigH genes encode highly similar proteins, there are multiple differences in adjacent genes. The single in vivo transcriptional start site identified in M. smegmatis and one of two identified in M. bovis BCG were found to have -35 promoter sequences that match the ECF-dependent -35 promoter consensus. Expression from these promoters was strongly induced by 50 degrees C heat shock. In comparison to the wild type, an M. smegmatis sigH mutant was found to be more susceptible to cumene hydroperoxide stress but to be similar in logarithmic growth, stationary-phase survival, and survival following several other stresses. Survival of an M. smegmatis sigH sigE double mutant was found to be markedly decreased following 53 degrees C heat shock and following exposure to cumene hydroperoxide. Expression of the second gene in the sigH operon is required for complementation of the sigH stress phenotypes. SigH is an alternative sigma factor that plays a role in the mycobacterial stress response.

Flavonoid glycosides from Thalictrum przewalskii

A new flavonoid glycoside, 5,7-dihydroxy-4'-methoxyflavone-7-O-[6-O-(4-O-acetyl-alpha-L-rhamnosyl)-3-O-beta-D-glucosyl]-6-O-acetyl-beta-D-glucoside and three known flavonoid glycosides, 5,7-dihydroxy-4-methoxyflavone-7-0-[6-0-(4-0-acetyl-alpha-L-rhamnosyl)]-beta-D-glucoside, 3,5,7, 4'-tetrahydroxyflavonol-3-O-beta-D-glucoside and 5,7-dihydroxy-4'-methoxyflavone-7-O-(6-O-alphaL-rhamnosyl)-beta-D-glucoside were isolated from the whole plant of Thalictrum przewalskii. Their structures were determined on the basis of spectroscopic evidences.

The effect of intra-articular irrigation injection therapy on osteoarthrosis of the temporomandibular joint

OBJECTIVE

To investigate the effect of intra-articular irrigation-injection therapy in treating osteoarthrosis of the temporomandibular joint.

MATERIALS AND METHODS

Thirty-seven patients (the test group) received intra-articular irrigation injection; 26 patients (the control group) received intra-articular injection of steroid. The synovial fluid, aspirated from five subjects of the test group before and after the therapy, was assayed to determine the tumor necrosis factor.

RESULTS

Clinical evaluations were performed 3 months after the therapy. Thirteen subjects in the test group fell into the "excellent" category, 19 into the "good" category, and five into the "no effect" category; in the control group, eight subjects fell into the "excellent" category; nine into the "good" category, and nine into the "no effect" category. The category difference in total effectiveness between the test group and the control group is statistically significant (X2 = 3.9340 P < 0.05). TNF in synovial fluid also showed statistically significant differences before and after treatment (T = 2.8825, P < 0.05).

CONCLUSIONS

Intra-articular irrigation injection is an effective therapy method for treating osteoarthrosis and is superior to intra-articular injection of steroid.

Xanthones from Hypericum japonicum and H. henryi

From the aerial part of Hypericum japonicum, one new xanthone glycoside, 1,5-dihydroxyxanthone-6-O-beta-D-glucoside, one novel dimer xanthone, bijaponicaxanthone, and the first natural prenylated xanthone, 1,3,5,6-tetrahydroxy-4-prenylxanthone, were isolated together with the four known xanthones, 1,5,6-trihydroxyxanthone, isojacereubin, 6-deoxyisojacareubin and 4',5'-dihydro-1,5,6-trihydroxy-4',4',5'-trimethylfurano (2',3':4,5) xanthone. five previously known xanthones, kielcorin, cadensin, 1,7,-dihydroxyxanthone, 1,5-dihydroxy-4-methoxyxanthone and 1,2,5-trihydroxyxanthone were also found in the dichoromethane extract of the stems and leaves of H. henryi. Their structures were elucidated by spectroscopic and chemical methods. Some of the compounds from H. japonicum were found to exert an interesting coagulant activity in an in vitro test. The chemotaxonomic value of xanthones is discussed briefly.

Subcellular distribution of protein phosphatases and abnormally phosphorylated tau in the temporal cortex from Alzheimer's disease and control brains

Microtubule-associated protein tau is abnormally hyperphosphorylated in the brain of patients with Alzheimer's disease (AD). In vitro studies have shown that protein phosphatases PP-2A and PP-2B can convert Alzheimer like tau to its normal state and that the activities of PP-1, PP-2A, and phosphotyrosyl-protein phosphatase (PTP) are reduced in AD brain. However, to have a direct effect on the regulation of phosphorylation on tau, these enzymes have to exist in neurons. Using specific polyclonal antibodies the levels of protein phosphatases PP-1, PP-2A, and PP-2B were determined by indirect ELISA in superior temporal cortical gray matter of AD and control brains. The protein levels of PP-2A and PP-2B were significantly increased in postsynaptosomal supernatant 2 (S2) of the AD group, and this alteration showed a significant linear correlation with levels of hyperphosphorylated tau. PP-1 and PTP-1B levels were not significantly changed in any of the AD fractions. Because of the large variation from case to case, the activity levels of none of the phosphatases investigated were significantly different between the AD and control groups. However, the PP-2B specific activity (activity/protein) showed a significant linear inverse correlation with hyperphosphorylated tau. These studies suggest that any attempt by the AD brain to compensate for the decreased tau phosphatase activity remains unsuccessful and that the decrease in phosphatase activity might contribute to increased levels of abnormally phosphorylated tau.

[A test of interleukin 2(IL-2) and T-cell subpopulation in patients with head and neck carcinomas]

OBJECTIVE:Serum levels of interleukin 2(IL-2) and peripheral blood T-cell subpopulation were measured in 35 patients with head and neck carcinomas.The results indicated that the pro-operative patients' CD8(+) was significantly higher,while the IL-2 level and CD4(+)/CD8(+) were greatly lower than that of controls (P<0.01),and CD4(+)was no significant difference.They were closely related with clinical stage.After operation,the CD8(+)decreated(P<0.01) and the serum IL-2 level,CD4(+)/CD8(+) elevated(p<0.01).It indicated that patients with head and neck carcinomas presented obvious abnormality of celluar immunological function.So,combined analysis of serum IL-2 and T-cell subpopulation may be useful to evaluate patients' immunological condition and to make up therapeutic plan.

Monitoring the genotoxicity of Lake Taihu, using two kinds of micronucleus tests

Mutagenicity of surface water in Lake Taihu was monitored by genotoxicological methods. The goal is to determine the situation concerning the contamination by mutagens, their distribution in the lake, and the potential effect on public health. In this study, the micronucleus test of Vicia faba root tip, a standard monitoring technique now in China, was carried out to make a preliminary screening of environmental mutagens in 39 representative sites of the lake. Highly significant differences in MCN permillage (average number of micronuclei per 1000 cells) and PI (pollution index) values were found among these sites. From the results, a rough distribution of the contamination could be obtained: mainly concentrated in the north-west area of the lake from several tributaries flowing into the lake. In order to provide further evidence, organic extracts from four entrances and one outlet of the five major tributaries were examined by the micronucleus test of human peripheral lymphocytes. The results were in accord with those of the micronucleus tests using Vicia faba. The tests also revealed that the intensity and mechanism of the pollutants were diverse in the different sources.

A mycobacterial extracytoplasmic function sigma factor involved in survival following stress

The extracytoplasmic function (ECF) sigma factors constitute a diverse group of alternative sigma factors that have been demonstrated to regulate gene expression in response to environmental conditions in several bacterial species. Genes encoding an ECF sigma factor of Mycobacterium tuberculosis, Mycobacterium avium, and Mycobacterium smegmatis, designated sigE, were cloned and analyzed. Southern blot analysis demonstrated the presence of a single copy of this gene in these species and in Mycobacterium bovis BCG, Mycobacterium leprae, and Mycobacterium fortuitum. Sequence analysis showed the sigE gene to be highly conserved among M. tuberculosis, M. avium, M. smegmatis, and M. leprae. Recombinant M. tuberculosis SigE, when combined with core RNA polymerase from M. smegmatis, reconstituted specific RNA polymerase activity on sigE in vitro, demonstrating that this gene encodes a functional sigma factor. Two in vivo transcription start sites for sigE were also identified in M. smegmatis and M. bovis BCG. Comparison of wild-type M. smegmatis with a sigE mutant strain demonstrated decreased survival of the mutant under conditions of high-temperature heat shock, acidic pH, exposure to detergent, and oxidative stress. An inducible protective response to oxidative stress present in the wild type was absent in the mutant. The mycobacterial SigE protein, although nonessential for viability in vitro, appears to play a role in the ability of these organisms to withstand a variety of stresses.

Lysine-based structure in the proregion of procathepsin L is the recognition site for mannose phosphorylation

The recognition of lysosomal enzymes by UDP-GlcNAc: lysosomal-enzyme GlcNAc-1-phosphotransferase (phosphotransferase) is mediated by a protein structure on lysosomal enzymes. It has been previously demonstrated that lysine residues are required for phosphorylation of procathepsin L and are a common feature of the site on many lysosomal proteins. In this work, the procathepsin L recognition structure was further defined by identification of the region of the protein containing the structure and the critical lysine residues involved. Removal of the cathepsin L propeptide by low pH-induced autocatalytic processing abolished phosphorylation. The addition of either the purified propeptide or a glutathione S-transferase-propeptide fusion protein to the processed protein restored phosphorylation. Mutagenesis of individual lysine residues demonstrated that two propeptide lysine residues (Lys-54 and Lys-99) were required for efficient phosphorylation of procathepsin L. By comparison of the phosphorylation rates of procathepsin L, lysine-modified procathepsin L, and the procathepsin L oligosaccharide, lysine residues were shown to account for most, if not all, of the protein-dependent interaction. On this basis, it is concluded that the proregion lysine residues are the major elements of the procathepsin L recognition site. In addition, lysine residues in cathepsin D were shown to be as important for phosphorylation as those in procathepsin L, supporting a general model of the recognition site as a specific three-dimensional arrangement of lysine residues exposed on the surface of lysosomal proteins.

Overproduction and rapid purification of human fast skeletal beta troponin T using Escherichia coli expression vectors: functional differences between the alpha and beta isoforms

Troponin T (TpnT), an essential component of the Ca(2+)-regulatory troponin complex, is involved in protein-protein interactions with other thin-filament proteins during muscle contraction in vertebrate striated muscle (VSM). The isoforms of TpnT are encoded by members of a multigene family which, by alternate splicing, produces a complex pattern of isoproteins in VSM. The functional domains of TpnT are only tentatively identified and structure-function analysis on this protein is limited due to the heterogeneity of the multiple isoforms. We reasoned that the overproduction and purification of a single TpnT species in Escherichia coli would provide an insight into these studies, besides being useful in crystallizing the protein. We cloned the human fast skeletal beta TpnT-encoding cDNA (beta TpnTf) in three expression vectors. Overexpression was achieved in an E. coli BL21 (DE3) lysogen using a T7 RNA polymerase promoter-based vector, pET17b. The unfused recombinant protein was purified by a simple and rapid procedure in a biologically active and immunoreactive form. This is the first successful synthesis of a complete beta TpnTf polypeptide from any species using an in vitro expression system. Purified human beta TpnTf, a predominant fetal form, was less Ca(2+)-sensitive and exhibited considerably reduced affinity for troponin C and tropomyosin, as compared to the rabbit fast skeletal alpha TpnT, a predominant adult isoform. These results provide a biochemical correlate to the age-related differences in Ca2+ sensitivity of tension development in vertebrate fast skeletal muscles.

Overexpression and rapid purification of rabbit fast skeletal troponin I from Escherichia coli: effect of different promoters, host strains, and culture conditions

Rabbit fast skeletal troponin I (TnIf) cDNA was expressed using two Escherichia coli expression vectors, pRE1 containing the bacteriophage lambda pL promoter and pAED4, a T7 RNA polymerase-based vector. Although both vectors expressed TnIf, overexpression of the target protein was achieved with pAED4. The effect of several parameters such as culture condition, compatible host strain, and inhibition of protein synthesis by rifampicin on the expression of TnIf was investigated. The overexpressed target protein synthesized during a brief induction period of only 2 h was conveniently purified from inclusion bodies by a simple and rapid procedure involving extraction with urea, ultracentrifugation, DE-52 column chromatography, and gel filtration. About 50-75 mg of highly purified TnIf was obtained per liter E. coli culture by this method, which does not involve time-consuming multistep procedures such as affinity and ion exchange chromatography as previously reported in the literature. The isolated unfused protein is stable and is indistinguishable from native protein in all biological parameters examined. The parameters optimized in this report for overexpression of TnIf may also be applicable for other eukaryotic proteins.

[Clinical analysis of 5 cases of peritoneal mesothelioma]

Peritoneal mesothelioma is an infrequently encountered tumor that has a poor prognosis. Five female cases are reported in this article: one of epithelial type, one fibrous and three mixed, and there are two benign and three malignant cases. Abdominal mass, pain, ascites and weight loss are main manifestations. The epithelial and mixed types are prone to produce ascites. CT scanning is helpful for preoperation diagnosis. In 3 of the 5 patients the tumors have been thoroughly removed, one patient was treated with a partial removal, and one with biopsy only. Two patients have received chemotherapy after operation. The four patients who were given effective treatment survived each longer than 12 years, 55 months, 26 months and 15 months. One of the 5 patients who received biopsy only at laparotomy died two months later. It is recommended that if the primary tumor of the organs in the peritoneal cavity could be excluded, any patient with an abdominal mass and ascites should be given the benefit of doubt that it might be a case of peritoneal mesothelioma. Laparotomy should be carried out, and all the visible tumor masses should be resected as completely as possible. Cytoreductive surgery should be done in patients with recurrence. If postoperative chemotherapy or radiotherapy is given the prognosis may be improved.

The proregion of cathepsin L is required for proper folding, stability, and ER exit

To investigate the role of the proregion in the biosynthesis and trafficking of mouse cathepsin L, cathepsin L cDNAs encoding proteins with altered proregions were constructed and their expression in COS cells was examined. As in transformed cells, normal mouse cathepsin L was secreted by COS cells. In contrast, two altered proregion cathepsin L proteins, one in which the proregion was deleted and a second in which the proregion was replaced with that of a homologous protein (aleurain), were retained within the cell and degraded over a period of 2-6 h. Immunofluorescence localization and the lack of effect of NH4Cl and brefeldin A on the turnover of the altered cathepsin L proteins indicated that their degradation occurred in the endoplasmic reticulum (ER). By using brefeldin A to induce colocalization of the UDPGlcNAc: lysosomal enzyme N-acetylglucosamine-1-phosphotransferase with the cathepsin L proteins in the ER, it was shown that the altered proteins were not susceptible to mannose phosphorylation as they exist in the ER. Trypsin sensitivity assays indicated that altered proregion proteins synthesized in COS cells or in vitro are misfolded. Taken together, these results indicate that the proregion plays an essential role in proper folding of cathepsin L. ER retention, decreased stability, and lack of mannose phosphorylation of the altered proteins are most likely secondary effects resulting from improper folding.

Isolation and characterization of human fast skeletal beta troponin T cDNA: comparative sequence analysis of isoforms and insight into the evolution of members of a multigene family

A cDNA encoding human fast skeletal beta troponin T (beta TnTf) has been isolated and characterized from a fetal skeletal muscle library. The cDNA insert is 1,000 bp in length and contains the entire coding region of 777 bp and 5' and 3' untranslated (UT) segments of 12 and 211 bp, respectively. The 3' UT segment shows the predicted stem-loop structure typical of eukaryotic mRNAs. The cDNA-derived amino acid sequence is the first available sequence for human beta TnTf protein. It is encoded by a single-copy gene that is expressed in a tissue-specific manner in fetal and adult fast skeletal muscles. Although the human beta TnTf represents the major fetal isoform, the sequence information indicates that this cDNA and the coded protein are quite distinct from the fetal and neonatal TnTf isoforms reported in other mammalian fetal muscles. The hydropathy plot indicates that human beta TnTf is highly hydrophilic along its entire length. The protein has an extremely high degree of predicted alpha-helical content involving the entire molecule except the carboxy-terminal 30 residues. Comparative sequence analysis reveals that the human beta TnTf shares a high level of sequence similarity in the coding region with other vertebrate TnTf and considerably reduced similarity with slow skeletal and cardiac TnT cDNAs. The TnT isoforms have a large central region consisting of amino acid residues 46-204 which shows a high sequence conservation both at the nucleotide and amino acid levels. This conserved region is flanked by the variable carboxy-terminal and an extremely variable amino-terminal segment. The tropomyosin-binding peptide of TnT, which is represented by amino acid residues 47-151 and also includes a part of troponin I binding region, is an important domain of this central segment. It is suggested that this conserved segment is encoded by an ancestral gene. The variable regions of vertebrate striated TnT isoforms reflect the subsequent addition and modification of genomic sequences to give rise to members of the TnT multigene family.

Characterization of a rabbit fast skeletal troponin I cDNA: a comparative sequence analysis of vertebrate isoforms and tissue-specific expression of a single copy gene

A cDNA encoding skeletal fast troponin I (TnIf) has been isolated and characterized from an adult rabbit fast skeletal muscle cDNA library. This cDNA contains the entire coding region of 549 base pairs (bp), the 3' untranslated (UT) segment of 78 bp and the 5' UT segment of 74 bp. The 3' UT segment shows the predicted stem-loop structure characteristic of eukaryotic mRNAs. The cDNA-derived amino acid sequence is not identical to the chemically-derived and the recently reported cDNA-derived amino acid sequences for rabbit TnIf, and thus enables to make the necessary corrections in the sequence information. The rabbit TnIf is encoded by a single copy gene which is expressed in adult fast skeletal muscle in a tissue-specific manner. Comparative sequence analysis of the vertebrate TnI isoforms and their cDNAs shows a high level of sequence conservation in the coding region among the TnIf interspecies isoforms. The sequence similarity is markedly decreased among the fast, slow and cardiac intra- and inter-species isoforms. The C-terminal halves of TnI isoforms including a segment believed to be involved in critical interactions with actin and troponin C (TnC) show high sequence conservation whereas the N-terminal halves show considerable difference in sequence and size. The significance of these results in relation to the biological function and evolution of members of the vertebrate TnI multigene family is discussed.

Human embryonic myosin heavy chain cDNA. Interspecies sequence conservation of the myosin rod, chromosomal locus and isoform specific transcription of the gene

A 3.6 kilobase cDNA clone coding for the human embryonic myosin heavy chain has been isolated and characterized from an expression library prepared from human fetal skeletal muscle. The derived amino acid sequence for the entire rod part of myosin shows 97% sequence homology between human and rat and a striking interspecies sequence conservation among the charged amino acid residues. The single copy gene is localized to human chromosome 17 and its expression in fetal skeletal muscle is developmentally regulated. The sequence information permits the design of isoform-specific probes for studies on the structure of the gene and its role in normal and defective human myogenesis.