Basic anatomy and tumor biology of the RPS6KA6 gene that encodes the p90 ribosomal S6 kinase-4

The RPS6KA6 gene encodes the p90 ribosomal S6 kinase-4 (RSK4) that is still largely uncharacterized. In this study we identified a new RSK4 transcription initiation site and several alternative splice sites with a 5’RACE approach. The resulting mRNA variants encompass four possible first start codons. The first 15 nucleotides (nt) of exon 22 in mouse and the penultimate exon in both human (exon 21) and mouse (exon 24) RSK4 underwent alternative splicing, although the penultimate exon deleted variant appeared mainly in cell clines, but not in most normal tissues. Demethylation agent 5-azacytidine inhibited the deletion of the penultimate exon whereas two indolocarbazole-derived inhibitors of cyclin dependent kinase 4 or 6 induced deletion of the first 39 nt from exon 21 of human RSK4. In all human cancer cell lines studied, the 90-kD wild type RSK4 was sparse but, surprisingly, several isoforms at or smaller than 72-kD were expressed as detected by seven different antibodies. On immunoblots, each of these smaller isoforms often appeared as a duplet or triplet and the levels of these isoforms varied greatly among different cell lines and culture conditions. Cyclin D1 inhibited RSK4 expression and serum starvation enhanced the inhibition, whereas c-Myc and RSK4 inhibited cyclin D1. The effects of RSK4 on cell growth, cell death and chemoresponse depended on the mRNA variant or the protein isoform expressed, on the specificity of the cell lines, as well as on the anchorage-dependent or -independent growth conditions and the in vivo situation. Moreover, we also observed that even a given cDNA might be expressed to multiple proteins; therefore, when using a cDNA, one needs to exclude this possibility before attribution of the biological results from the cDNA to the anticipated protein. Collectively, our results suggest that whether RSK4 is oncogenic or tumor suppressive depends on many factors.

Clinical features of axial undifferentiated spondyloarthritis (USpA) in China: HLA-B27 is more useful for classification than MRI of the sacroiliac joint

OBJECTIVES

To analyse the clinical features of Chinese undifferentiated spondyloarthritis (USpA) patients with predominantly axial involvement, and in particular the influence of human leucocyte antigen (HLA)-B27 and magnetic resonance imaging (MRI) of the sacroiliac joint (SIJ) on the classification of axial USpA.

METHODS

Patients with low back pain for ≥ 3 months and no definite radiographic sacroiliitis were enrolled in this study. They were diagnosed as USpA based on rheumatologists' findings. Correlations between clinical features and HLA-B27 status or MRI manifestations were analysed.

RESULTS

A total of 197 USpA patients were recruited, of whom 135 (70.3%) were positive for HLA-B27. Acute inflammation, structural damage lesions, and normal findings on SIJ MRI were recorded in 64.5, 13.2 and 22.3% of patients, respectively. Classification criteria for axial SpA according to the European Spondylarthropathy Study Group (ESSG), Amor, and the Assessment of SpondyloArthritis International Society (ASAS) were fulfilled by 63.5, 64.5 and 83.2% patients, respectively. Cross-validation showed significant correlation among these three criteria. Patients positive for HLA-B27 included more males, with earlier onset age, better response to non-steroidal anti-inflammatory drugs (NSAIDs), and higher erythrocyte sedimentation rate (ESR)/C-reactive protein (CRP) levels. In addition, more HLA-B27-positive than HLA-B27-negative patients fulfilled the ESSG, Amor, and ASAS criteria. Patients with acute inflammation on SIJ MRI had a higher level of ESR/CRP, and a greater proportion of them fulfilled the Amor and ASAS criteria. However, the proportion of those fulfilling the ESSG criteria did not differ with different MRI manifestations.

CONCLUSION

Both HLA-B27 status and SIJ MRI findings influence the classification of Chinese axial USpA patients, but HLA-B27 seems of more value.

Effect of Ambient Gas Pressure on Pulsed Laser Ablation Plume Dynamics and Znte Film Growth

Epitaxial thin films of nitrogen-doped p-ZnTe were grown on single-crystal, semi-insulating GaAs substrates via pulsed laser ablation of a stoichiometric ZnTe target. Both low pressure nitrogen ambients and high vacuum were used. Results of in situ reflection high energy electron diffraction (RHEED) and time-resolved ion probe measurements have been compared with ex situ Hall effect and transmission electron microscopy (TEM) measurements. A strong correlation was observed between the nature of the film's surface during growth (2-D vs. 3-D, assessed via RHEED) and the ambient gas pressures employed during deposition. The extended defect content (assessed via cross-sectional TEM) in the region >150 nm from the film/substrate interface was found to increase with the ambient gas pressure during deposition, which could not be explained by lattice mismatch alone. At sufficiently high pressures, misoriented, columnar grains developed which were not only consistent with the RHEED observations but also were correlated with a marked decrease in Hall mobility and a slight decrease in hole concentration. Ion probe measurements, which monitored the attenuation and slowing of the ion current arriving at the substrate surface, indicated that for increasing nitrogen pressure the fast (vacuum) velocity-distribution splits into a distinct fast and two collisionally-slowed components or modes. Gas-controlled variations in these components mirrored trends in electrical properties and microstructural measurements.

Electrical properties in magnetic field of macroscopic carbon nanotube objects

The electrical properties including zero-field resistivity, magnetoresistance and current-voltage (I-V) curves of macroscopic carbon nanotube (CNT) objects (yarns, bundles, films, and networks) have been measured. The macroscopic CNT objects exhibit semiconductor-like behaviors. Under the magnetic field applied perpendicular to the plane or axis of the Macroscopic CNT objects, a pronounced negative magnetoresistance have been observed. Due to the aligned, close-packed structure of MWNT yarn, its MR reach as high as -17% at 9 T. The I-V curves of the MWNT network exhibit a linear relationship even at low temperature, but the other samples exhibit a nonlinear relationship, indicating the effect of morphology and defects of CNTs in macroscopic CNT objects.

Requirement of a novel splicing variant of human histone deacetylase 6 for TGF-beta1-mediated gene activation

Histone deacetylase 6 (HDAC6) belongs to the family of class IIb HDACs and predominantly deacetylates non-histone proteins in the cytoplasm via the C-terminal deacetylase domain of its two tandem deacetylase domains. HDAC6 modulates fundamental cellular processes via deacetylation of alpha-tubulin, cortactin, molecular chaperones, and other peptides. Our previous study indicates that HDAC6 mediates TGF-beta1-induced epithelial-mesenchymal transition (EMT) in A549 cells. In the current study, we identify a novel splicing variant of human HDAC6, hHDAC6p114. The hHDAC6p114 mRNA arises from incomplete splicing and encodes a truncated isoform of the hHDAC6p114 protein of 114kDa when compared to the major isoform hHDAC6p131. The hHDAC6p114 protein lacks the first 152 amino acids from N-terminus in the hHDAC6p131 protein, which harbors a nuclear export signal peptide and 76 amino acids of the N-terminal deacetylase domain. hHDAC6p114 is intact in its deacetylase activity against alpha-tubulin. The expression hHDAC6p114 is elevated in a MCF-7 derivative that exhibits an EMT-like phenotype. Moreover, hHDAC6p114 is required for TGF-beta1-activated gene expression associated with EMT in A549 cells. Taken together, our results implicate that expression and function of hHDAC6p114 is differentially regulated when compared to hHDAC6p131.

Introduction of a rice blight resistance gene,Xa21, into five Chinese rice varieties through an Agrobacterium-mediated system

A cloned gene, Xa21 was transferred into five widely-used Chinese rice varieties through an Agrobacterium- mediated system, and over 110 independent transgenic lines were obtained. PCR and Southern analysis of transgenic plants revealed the integration of the whole Xa21 gene into the host genomes. The integrated Xa21 gene was stably inherited, and segregated in a 3: 1 ratio in the selfed T(1) generation when one copy of the gene was integrated in the transformants. Inoculation tests displayed that transgenic T(0) plants and Xa21 PCR-positive T(1) plants were highly resistant to bacterial blight disease. The selected Xa21 homozygous resistant transgenic lines with desirable qualities may be propagated as new varieties or utilized in hybrid rice breeding.

A novel anti-tumor protein extracted from Meretrix meretrix Linnaeus induces cell death by increasing cell permeability and inhibiting tubulin polymerization

Discovery and development of new pharmaceuticals from marine organisms are attracting increasing interest. Several agents derived from marine organisms are under preclinical and clinical evaluation as potential anti-cancer drugs. We extracted and purified a novel anti-tumor protein from the coelomic fluid of Meretrix meretrix Linnaeus by ammonium sulphate fractionation, ion exchange and hydrophobic interaction chromatography. The molecular weight of the highly purified protein, designated MML, was 40 kDa as determined by SDS-PAGE analysis. MML exhibited significant cytotoxicity to several cancer cell types, including human hepatoma BEL-7402, human breast cancer MCF-7 and human colon cancer HCT116 cells. However, no inhibitory effect was found when treating murine normal fibroblasts NIH3T3 and benign human breast MCF-10A cells with MML. The cell death induced by MML was characterized by cell morphological changes. The induction of apoptosis of BEL-7402 cells by MML was weak by DNA ladder assay. The possible mechanisms of its anti-tumor effect might be the changes in cell membrane permeability and inhibition of tubulin polymerization. MML may be developed as a novel, highly selective and effective anti-cancer drug.

Sub-visible particle quantitation in protein therapeutics

Biologics represent a large and growing segment of the therapeutic medicinal market. Sub-visible particles present in these products are a product quality attribute and a potential patient safety concern yet to be fully explored. Early and consistent particle quantitation and control throughout the product life cycle of these drugs from development to commercial lot release is critical in mitigating any concerns. This requires appropriate analytical methods which can be applied to biopharmaceuticals across a large variety of protein concentrations and modes of administration. The compendial light obscuration method for quantitating sub-visible particles in small volume parenterals is not ideally suited for therapeutic biologics. Approaches to modify the current compendial method so that it is applicable to biologics, including appropriate sample preparation, reduced assay sample volume, increased sizing information, and development of an appropriate sampling plan, are presented in this article. Successful applications of a modified light obscuration method to therapeutic protein products are demonstrated, and a strategy to utilise complimentary methods and techniques at different phases of product development is discussed.

Mikrotaster für Anwendungen in der taktilen Wegmesstechnik (Micro Probe for Dimensional Metrology)

Das weiterentwickelte und optimierte Design eines auf Bulk-Silizium-Technologie basierenden 3-D-Kraftsensors wird beschrieben. In vorangegangenen Untersuchungen konnte gezeigt werden, dass sich dieser Kraftsensor zum Einsatz in der taktilen Wegmesstechnik als Antastsensor eignet. Das Sensorelement besteht aus einer mit mikrotechnischen Herstellungsverfahren gefertigten Silizium-Bossmembran. In diesem Bericht wird ein neues Design und eine neue Auswertungsstrategie für diesen Sensortyp beschrieben.

Unique structure and property of cyclodextrins and their application in transdermal drug delivery

Owing to their bioadaptability and multifunctional characteristics, cyclodextrins have been shown to be useful in drug delivery systems. This article presents the unique structure and properties and the current application of natural and chemically modified cyclodextrins in transdermal drug delivery systems, focusing on their ability to enhance the solubility and stability of drug molecules and to improve drug absorption across biological barriers.

Mutations in the LDL receptor gene in four Chinese homozygous familial hypercholesterolemia phenotype patients

BACKGROUND AND AIMS

Familial hypercholesterolemia (FH) is an autosomal dominant disorder of lipoprotein metabolism caused by mutations in the low-density lipoprotein receptor (LDL-R) gene, leading to elevated levels of cholesterol and an increased risk of coronary heart disease. In this article, from four homozygous FH phenotype probands we identified disease causing mutations and analyzed the relationship between genotype and phenotype.

METHODS AND RESULTS

DNA sequencing identified five LDL-R point mutations in four unrelated families. We found a novel homozygous mutation (C210R), a homozygous mutation at W462X, a compound heterozygous mutation of C122Y and T383I, and a G>A intron 3 splice site homozygous mutation. The functional alteration caused by the novel C210R mutation was confirmed by FACS analysis. Four probands have high low-density lipoprotein cholesterol (LDL-C) levels, ranging from 14.65 to 27.66 mmol/L. Their heterozygous parents had relatively low levels. B-mode ultrasound supplemented by Doppler was used to examine aortic/mitral valve structural alterations and carotid intima-media thickness (ITM) in all probands. The ITM values were between 1.2 and 2.3mm, much higher than the normal value of <0.8mm.

CONCLUSION

Our data demonstrated that all the probands were associated with severe hypercholesterolemia, thick carotid IMT and a low CFVR (coronary flow velocity reserve) value. The novel mutation (C120Y) is a disease causing mutation.

Association of chromosome 2q36.1-36.3 and autosomal dominant transmission in ankylosing spondylitis: results of genetic studies across generations of Han Chinese families

Background:

Ankylosing spondylitis (AS) is a chronic, potentially crippling, spondyloarthropathy with strong genetic components affecting approximately 0.3% of the population. Its exact genetic mechanism and mode of transmission, however, remains obscure.

Methods and results:

The authors conducted a genome wide scan on 75 individuals across multiple generations of three Han Chinese families affected with AS. Segregation analysis and pedigree investigation suggested an autosomal dominant inheritance. Pairwise logarithm of odds (LOD) scores were calculated using LINKAGE package for the obtained genotypes. High resolution mapping was then performed based on markers with significant LOD scores. To minimise the number of crossovers in each family, haplotype were constructed and assigned. Two of the pedigrees shared one candidate region for AS on 2q36.1–2q36.3 spanning 6-cM (maximum heterogeneity LOD score of 12.41 at marker D2S2228), while the other showed strong linkage to the HLA-B region.

Conclusions:

This is the first report which proposes one of the new genetic models of autosomal dominant transmission in AS. The breakthrough in the identification of linkage to chromosome 2q36.1–2q36.3 and the HLA-B region highlights the future potential of more comprehensive genetic studies of determinants of disease risk.

Efficient antiproliferative and antiangiogenic effects on human ovarian cancer growth by gene transfer of attenuated mutants of Shiga-like toxin I

To evaluate the potential effect of anticancer and antiangiogenesis of Stx1(W203F) and Stx1(R170H), two attenuated mutants of Shiga-like toxin I (Stx1), in cancer gene therapy. Antiproliferative effects of these Stx1 mutants were tested in human ovarian carcinoma cell line SKOV3 and human umbilical vein endothelial cells (HUVECs) in vitro. Effect of these Stx1 mutants on inducing cell death and cell cycle arrest was analyzed in SKOV3 cells. Influence of these Stx1 mutants on endothelial cell function was analyzed in HUVECs. In vivo therapeutic effect of these Stx1 mutants on SKOV3 was explored using xenograft models in nude mice. These Stx1 mutants can inhibit the growth of SKOV3 or HUVECs and this effect can be abrogated by antibody specific for Stx1. They caused considerable cell death of SKOV3 cells in 24 h; neither caspase activity nor DNA fragmentation was observed, and necrosis is the major mode of cell death. These Stx1 mutants can induce cell cycle arrest of SKOV3 cells in G(2)-M or S phase depending on the dosage of gene transfer. Furthermore, they significantly decreased migration and capillary tube formation of HUVECs at low dose. In vivo study showed that Stx1(W203F) but not Stx1(R170H) significantly suppressed transplanted SKOV3 tumor growth in nude mice model. Interestingly, the microvessel densities of tumor treated with Stx1(W203F) and Stx1(R170H) were significantly reduced. This study suggests that genes encoding attenuated Stx1 can be selected as good candidates for the gene therapy of ovarian carcinoma because of their antiproliferative and antiangiogenic effects.

Potentiation of irinotecan sensitivity by Se-methylselenocysteine in an in vivo tumor model is associated with downregulation of cyclooxygenase-2, inducible nitric oxide synthase, and hypoxia-inducible factor 1alpha expression, resulting in reduced angiogenesis

Until recently, the use of Se-methylselenocysteine (MSC) as selective modulator of the antitumor activity and selectivity of anticancer drugs including irinotecan, a topoisomerase I poison, had not been evaluated. Therapeutic synergy between MSC and irinotecan was demonstrated by our laboratory in mice bearing human squamous cell carcinoma of the head and neck tumors. In FaDu xenografts, a poorly differentiated tumor-expressing mutant p53, the cure rate was increased from 30% with irinotecan alone to 100% with the combination of irinotecan and MSC. Cellular exposure to cytotoxic concentration of SN-38, the active metabolite of irinotecan (0.1 microM) alone and in combination with noncytotoxic concentration of MSC (10 microM) did not result in additional enhancement of chk2 phosphorylation and downregulation of specific DNA replication-associated proteins, cdc6, MCM2, cdc25A, nor increase in PARP cleavage, caspase activation and the 30-300 kb DNA fragmentation induced by SN-38 treatment. MSC did not alter significantly markers associated with apoptosis, nor potentiate irinotecan-induced apoptosis. These results indicate that apoptosis is unlikely to be one of the main mechanism associated with the observed in vivo therapeutic synergy. In contrast, significant downregulation of cyclooxygenase-2 (COX-2) expression and activity was observed in the cells exposed to SN-38 in combination with MSC compared to SN-38 alone. Moreover, the inhibition of PGE(2) production was also observed in the cells treated with the combination as compared with SN-38 alone. Analysis of tumor tissues at 24 h after treatment with synergistic modality of irinotecan and MSC revealed significant downregulation of COX-2, inducible nitric oxide synthase (iNOS) and hypoxia-induced factor-1alpha expression (HIF 1alpha). Moreover, decreased microvessel density was observed after irinotecan treatment with the addition of MSC. These results suggest that observed therapeutic synergy correlates with the inhibition of neoangiogenesis through the downregulation of COX-2, iNOS and HIF-1alpha expression.

A slide latex agglutination test for the rapid detection of antibodies in serum against porcine parvovirus

A slide latex agglutination test (LAT) was developed and evaluated to detect serum antibodies against porcine parvovirus. Porcine parvovirus antigen was obtained by 10% PEG-6000 and 0.5 mol/l sodium chloride precipitation, and inactivated by 0.1% methanal. Two per cent suspensions of latex particles (0.5-0.8 microm) were coated by adding an equal volume of porcine parvovirus antigen at 0.34 microg/ml. Repeatability of latex agglutination test was evaluated with a panel of 100 sera using the same and different antigen lots. A good agreement between LAT and haemagglutination inhibit assay was observed. Because of convenience and speed of performance, this method would be used widely in clinic examination.

Detection of porcine circovirus type 2, porcine parvovirus and porcine pseudorabies virus from pigs with postweaning multisystemic wasting syndrome by multiplex PCR

Multiplex PCR was established to detect porcine circovirus type 2 (PCV-2), porcine parvovirus (PPV) and porcine pseudorabies virus (PRV) and applied to samples from 137 piglets exhibiting clinical signs of postweaning multisystemic wasting syndrome (PMWS). PCV-2 DNA was detected from all samples. Moreover, 43 samples were positive for PPV but negative for PRV; 11 samples were positive for PRV but negative for PPV; and 35 samples were positive both for PPV and PRV. These results suggests that PCV-2 co-infection with PRV and PPV may play an important role in PMWS. Also, multiplex PCR is an appropriate candidate method for diagnosis of PCV-2, PRV and PPV simultaneously in field cases.

Excitatory amino acids, TNF-alpha, and chemokine levels in synovial fluids of patients with active arthropathies

The aim of this study was to assess the synovial fluid (SF) neurotransmitter excitatory amino acid (EAA) levels, including glutamate (Glu) and aspartate (Asp), in the context of SF levels of other amino acids, TNF-alpha and chemokines from patients with active arthropathies. The SF was collected from patients with active rheumatoid arthritis (RA), gout, or osteoarthritis (OA). The SF samples were analysed for levels of neurotransmitters glutamate and aspartate, tumour necrosis factor-alpha (TNF-alpha), Regulated upon Activation Normally T-cell Expressed and Secreted (RANTES), macrophage inhibitory factor-1 alpha (MIP-1alpha) and interleukin 8 (IL-8). SF WBC counts were also determined. Correlations between SF EAA, TNF-alpha and chemokines were determined by the Pearson product-moment correlation. Primary cultures derived from SF from active RA and gout patients were incubated with added l-glutamate, to assess if exposure to Glu could increase TNF-alpha levels. There were significant elevations in SF EAA, SF TNF-alpha and SF RANTES in RA patients compared to gout or OA patients. Significant correlations between SF EAA and SF RANTES, MIP-1alpha and IL-8 levels were seen, and SF EAA and SF TNF-alpha or SF WBC levels approached significance. Addition of exogenous neurotransmitter glutamate significantly increased TNF-alpha levels in primary cell cultures derived from RA and gout patients. The SF neurotransmitter EAA levels significantly correlated to selected SF chemokine levels, in clinically active RA, gout and OA patients, independent of disease. Added Glu resulted in significantly increased TNF-alpha levels in primary synovial cell cultures. These data expand the relationship of SF neurotransmitter EAA levels to SF cytokines and chemokines in patients with clinically active arthritis, and suggest that neurotransmitters Glu and Asp contribute to peripheral inflammatory processes.

Influence of caveolin on constitutively activated recombinant eNOS: insights into eNOS dysfunction in BDL rat liver

Diminished endothelial nitric oxide (NO) synthase (eNOS)-derived NO production from the hepatic vascular endothelium contributes to hepatic vasoconstriction in portal hypertension. The aim of this study was to examine the mechanism of this process by testing the influence of a constitutively active form of eNOS (S1179DeNOS) in both primary and propagated liver cells in vitro and in the sham and bile duct ligated (BDL) rat liver in vivo, using an adenoviral vector encoding green fluorescent protein (AdGFP) and S1179DeNOS (AdS1179DeNOS). AdS1179DeNOS transduction augmented basal and agonist-stimulated NO generation in nonparenchymal liver cells. Sham rats transduced in vivo with AdS1179DeNOS evidenced a decreased pressor response to incremental doses of the vasoconstrictor methoxamine compared with sham rats transduced with AdGFP. However, BDL rats transduced with AdS1179DeNOS did not display improved vasodilatory responses as evidenced by similar flow-dependent pressure increases to that observed in BDL rats transduced with AdGFP, despite similar levels of viral transgene expression. We next examined the influence of the eNOS inhibitory protein caveolin on S1179DeNOS dysfunction in cirrhotic liver. Immunogold electron microscopic analysis of caveolin in BDL liver demonstrated prominent expression not only in liver endothelial cells, but also in hepatic stellate cells. In vitro studies in the LX2 hepatic stellate cell line demonstrate that caveolin precipitates recombinant S1179DeNOS in LX2 cells, that recombinant S1179DeNOS coprecipitates caveolin, and that binding is enhanced in the presence of overexpression of caveolin. Furthermore, caveolin overexpression inhibits recombinant S1179DeNOS activity. These studies indicate that recombinant S1179DeNOS protein functions appropriately in normal liver cells and tissue but evidences dysfunction in the cirrhotic rat liver and that caveolin expression and inhibition in BDL nonparenchymal cells, including hepatic stellate cells, may account for this dysfunction.

Is intraoperative cholangiography during laparoscopic cholecystectomy cost effective?

BACKGROUND

Common bile duct injuries occur in 0.2% to 0.8% of laparoscopic cholecystectomies (LC). Intraoperative cholangiograms (IOCG) are a useful means of detecting common bile duct injuries in the operating room.

METHODS

Data were retrospectively reviewed for patients referred for management of common duct injuries from 1996 to 2000. Cost data were obtained from hospital records. Legal settlements were obtained from published sources.

RESULTS

Twenty-one patients (0.133%) were found to have bile duct injuries and incurred median hospital stays of 11.5 days at an average cost of $587,491. The average cost of those requiring reoperation was $669,134. The 21 cases in our sample had total charges of $10,819,767. Performing IOCG during each LC in Orange County would have cost $10,669,725. If extrapolated to state and nationwide levels, the savings is far greater.

CONCLUSIONS

IOCG during LC is a cost-effective means of preventing the costs of delayed recognition of bile duct injuries.

Laparoscopic ultrasound with radiofrequency ablation in cirrhotic patients with hepatocellular carcinoma: technique and technical considerations

The optimal treatment for hepatocellular carcinoma (HCC) is surgical resection. However, only a small percentage of patients are operative candidates. CT-guided percutaneous radiofrequency ablation (RFA) has been shown to be efficacious in treatment of unresectable HCC. CT-guided RFA, however, may fail to detect small intrahepatic metastases and tumor thrombi, which thus minimizes possible gains from the procedure. Recent advances in laparoscopic ultrasound have greatly improved the accuracy in detecting intrahepatic HCC metastases many of which were missed by CT. Combining intraoperative laparoscopic ultrasound with laparoscopic RFA greatly utilizes advances in both fields and is technically feasible. Our objective is to introduce a novel operative combination of laparoscopic ultrasound with laparoscopic RFA in treatment of HCC. Childs class B patients with unresectable HCC were considered for this study. Twelve patients underwent laparoscopic ultrasound and RFA of 17 lesions. Tumors ranged from 0.27 to 7 cm in diameter. Laparoscopic ultrasound identified tumor not detected preoperatively in one patient (8.3%). A single pneumothorax was the only complication. A single patient (8.3%) had recurrent disease and accounted for the only mortality in the study. We conclude that the use of both laparoscopic ultrasound and RFA is an excellent use of existing technology. The procedure combines improved tumor localization with the means to treat patients with unresectable disease. Because RFA is a relatively recent development long-term results are not yet available. Randomized prospective studies comparing RFA with other modalities will determine the ultimate utility of this procedure.

T cell immunity in neonates

Typically, neonates exhibit decreased or aberrant cellular immune responses when compared to adults, resulting in increased susceptibility to infection. However, it is clear that newborns are able to generate adult-like protective T cell responses under certain conditions. The focus of our research is to understand the deficiencies within the neonatal immune system that lead to improper cellular responses and how priming conditions can be altered to elicit the appropriate T cell response necessary to protect against development of pathogen-induced disease. With these goals in mind, we are exploring the attributes of neonatal T cells and their development, as well as the conditions during priming that influence the resulting response to immune challenge during the neonatal period.

[Effect of inhibition of polyamine biosynthesis on the growth and telomerase activity of human laryngeal carcinoma cells Hep-2]

OBJECTIVE

To observe the effect of difluoromethylornithine (DFMO), an inhibitor of polyamine biosynthesis, on the growth and telomerase activity of human laryngeal carcinoma cells Hep-2, and try to find a new clue to search for the mechanism of reversion of tumor malignant phenotype via polyamine biosynthesis inhibition.

METHODS

The growth characteristics of Hep-2 cells treated with DFMO were studied by morphological observation, cell growth curve and FCM analysis. Telomerase activity was detected by Telomerase Repeat Amplification Protocol (TRAP).

RESULTS

The inhibition of cell proliferation, a marked increase in G1 and a decrease in S phase populations in the cell cycle of 2.5 mmol/L or 5 mmol/L DFMO treated Hep-2 cells were demonstrated; The cell apoptosis was shown by cell morphology and apoptosis peak in FCM; The telomerase activity of the treated cells was suppressed, while these changes were prevented by provision of exogenous putrescine(Pu) along with DFMO.

CONCLUSION

Inhibition of polyamine biosynthesis could result in the proliferation inhibition and apoptosis induction of Hep-2 cells, which was associated with suppressed telomerase activity. It is suggested that inactivation of telomerase would be one of the important molecular events in reversion of tumor malignant phenotype via inhibition of polyamine biosynthesis.

Image analysis for quantitation of solid tumor drug sensitivity

BACKGROUND

A method of assessing chemosensitivity of tissue has been described by Rotman et al. The aim of this study was to use image analysis to provide a more rapid and quantitative means of assessing drug effect on tissue proliferative capacity.

METHOD

Fluoropyrimidine sensitive Ward rat colon adenocarcinoma tumor was implanted onto collagen impregnated cellulose fibers suspended on metal grids at an air-fluid interface and kept in a 95% air/5% CO2 incubator at 37 degrees C. The fluorescent microscopic image captured by a silicon intensified target (low light detecting) camera and linked to an image processing unit was measured for fluorescent brightness and tumor image area. Blinded 5-Fluorouracil (5-FU) drug treatment was begun 8 days after tumor explantation on the collagen-cellulose matrix. Tumor image area and fluorescent brightness were measured at 24 h pretreatment, 48 h posttreatment, and at 48 h post drug removal.

RESULTS

Nontreated tumor cultures demonstrated an increase in area and fluorescent brightness with time following tumor implantation on the collagen gel. Dose responsiveness was seen with increasing concentrations of 5-FU. At the highest clinically achievable concentration of 5-FU (500 microM), there was a 39% decrease in area compared with the nontreated group, 113%. Linear dose responsiveness was not demonstrated between 50 and 150microM 5-FU.

CONCLUSIONS

Fluoropyrimidine activity was demonstrated with the implemented image analysis system. The in vitro tumor sensitivity to FU using collagen gel was consistent with responsiveness of tumors in vivo borne by rats.

Germinal center reaction in the joints of mice with collagen-induced arthritis: an animal model of lymphocyte activation and differentiation in arthritis joints

OBJECTIVE

To establish an animal model and provide a basis for investigating the role of germinal center (GC) reaction in autoimmune arthritis.

METHODS

DBA/1 mice were immunized with bovine type II collagen (CII) to elicit collagen-induced arthritis (CIA). Sections of arthritic joints were examined by in situ immunohistochemical studies, and purified cells from affected joints were subjected to flow cytometry analysis.

RESULTS

De novo GC reaction was induced in the arthritic joints of male DBA/1 mice by immunization with bovine CII. In comparison with GCs formed in lymphoid tissues, such as spleen and lymph nodes, we found that these GCs formed in the joint tissues of mice with CIA were morphologically typical, as determined by immunohistologic and flow cytometric assays.

CONCLUSION

The local immune responses in murine CIA induced ectopic GC formation, as observed in the synovial tissues of patients with rheumatoid arthritis. This system will allow for the first time the direct study of the role of the GC reaction in autoimmune arthritis in an animal model.

Regulation of hepatic eNOS by caveolin and calmodulin after bile duct ligation in rats

In carbon tetrachloride-induced liver cirrhosis, diminution of hepatic endothelial nitric oxide synthase (eNOS) activity may contribute to impaired hepatic vasodilation and portal hypertension. The mechanisms responsible for these events remain unknown; however, a role for the NOS-associated proteins caveolin and calmodulin has been postulated. The purpose of this study is to characterize the expression and cellular localization of the NOS inhibitory protein caveolin-1 in normal rat liver and to then examine the role of caveolin in conjunction with calmodulin in regulation of NOS activity in cholestatic portal hypertension. In normal liver, caveolin protein is expressed preferentially in nonparenchymal cells compared with hepatocytes as assessed by Western blot analysis of isolated cell preparations. Additionally, within the nonparenchymal cell populations, caveolin expression is detected within both liver endothelial cells and hepatic stellate cells. Next, studies were performed 4 wk after bile duct ligation (BDL), a model of portal hypertension characterized by prominent cholestasis, as evidenced by a significant increase in serum cholesterol in BDL animals. After BDL, caveolin protein levels from detergent-soluble liver lysates are significantly increased as assessed by Western blot analysis. Immunoperoxidase staining demonstrates that this increase is most prominent within sinusoids and venules. Additionally, caveolin-1 upregulation is associated with a significant reduction in NOS catalytic activity in BDL liver lysates, an event that is corrected with provision of excess calmodulin, a protein that competitively binds eNOS from caveolin. We conclude that, in cholestatic portal hypertension, caveolin may negatively regulate NOS activity in a manner that is reversible by excess calmodulin.

Use of zwitterionic micelles in the eluent II: a new approach to ion chromatographic analysis of inorganic cations in biological fluids with direct sample injection

A new ion chromatographic (IC) technique has been developed for the determination of inorganic cations in biological fluids with direct sample injection. This involved the use of a mixed zwitterionic-micelle/electrolyte solution as an eluent. The proteins in the sample became bound to the zwitterionic micelles in the eluent and were thus eliminated from the column. The cations were separated by cation exchange. This method is ideal for the online, simultaneous determination of common inorganic cations (Na+, NH4+, K+, Mg2+, and Ca2+) in urine and serum samples. Such an application was demonstrated experimentally. Non-suppressed conductivity was used for analyte detection. The detection limits obtained using this IC system were 2.94, 5.22, 34.9, 32.6, and 56.7 microg/L for Na+, NH4+, K+, Mg2+, and Ca2+, respectively.

Effect of long-term exposure to fluoride in drinking water on risks of bone fractures

Findings on the risk of bone fractures associated with long-term fluoride exposure from drinking water have been contradictory. The purpose of this study was to determine the prevalence of bone fracture, including hip fracture, in six Chinese populations with water fluoride concentrations ranging from 0.25 to 7.97 parts per million (ppm). A total of 8266 male and female subjects > or =50 years of age were enrolled. Parameters evaluated included fluoride exposure, prevalence of bone fractures, demographics, medical history, physical activity, cigarette smoking, and alcohol consumption. The results confirmed that drinking water was the only major source of fluoride exposure in the study populations. A U-shaped pattern was detected for the relationship between the prevalence of bone fracture and water fluoride level. The prevalence of overall bone fracture was lowest in the population of 1.00-1.06 ppm fluoride in drinking water, which was significantly lower (p < 0.05) than that of the groups exposed to water fluoride levels > or =4.32 and < or =0.34 ppm. The prevalence of hip fractures was highest in the group with the highest water fluoride (4.32-7.97 ppm). The value is significantly higher than the population with 1.00-1.06 ppm water fluoride, which had the lowest prevalence rate. It is concluded that long-term fluoride exposure from drinking water containing > or =4.32 ppm increases the risk of overall fractures as well as hip fractures. Water fluoride levels at 1.00-1.06 ppm decrease the risk of overall fractures relative to negligible fluoride in water; however, there does not appear to be similar protective benefits for the risk of hip fractures.

Determination of hydrogen ion by ion chromatography (IC) with sulfonated cation-exchange resin as the stationary phase and aqueous EDTA (ethylenediamine-N,N,N',N'-tetraacetic acid) solution as the mobile phase

An ion chromatographic (IC) method has been developed for determination of hydrogen ion (H+). It is based on the use of sulfonated cation-exchange resin as stationary phase, aqueous ethylenediamine-N,N,N',N'-tetraacetic acid (dipotassium salt, EDTA-2K, written as K2H2Y) solution as mobile phase, and conductivity for detection. H+ was separated mainly by cation-exchange, but its elution was accelerated by the presence of EDTA. The order of elution for the model cations was H+ > Li+ > Na+ > NH4+ > Ca2+ > > Mg2+. A sharp and highly symmetrical peak was obtained for H+ and this was attributed to the capacity of H2Y2(2-) to receive and bind H+. H+ was detected conductiometrically and detector response (reduction in conductivity as a result of H+ +H2Y2- --> H3Y-) was linearly proportional to the concentration of H+ in the sample. The detection limit for H+ with this IC system was better than 4.7 micromol L(-1). A significant advantage of this method was the ability to separate and determine, in one step, H+ and other cations. The successful determination of H+ and other cation species in real acid-rain samples demonstrated the usefulness of this method.

Direct interaction between endothelial nitric-oxide synthase and dynamin-2. Implications for nitric-oxide synthase function

Endothelial nitric-oxide synthase (eNOS) is regulated in part through specific protein interactions. Dynamin-2 is a large GTPase residing within similar membrane compartments as eNOS. Here we show that dynamin-2 binds directly with eNOS thereby augmenting eNOS activity. Double label confocal immunofluorescence demonstrates colocalization of eNOS and dynamin in both Clone 9 cells cotransfected with green fluorescent protein-dynamin and eNOS, as well as in bovine aortic endothelial cells (BAEC) expressing both proteins endogenously, predominantly in a Golgi membrane distribution. Immunoprecipitation of eNOS from BAEC lysate coprecipitates dynamin and, conversely, immunoprecipitation of dynamin coprecipitates eNOS. Additionally, the calcium ionophore, a reagent that promotes nitric oxide release, enhances coprecipitation of dynamin with eNOS in BAEC, suggesting the interaction between the proteins can be regulated by intracellular signals. In vitro studies demonstrate that glutathione S-transferase (GST)-dynamin-2 quantitatively precipitates both purified recombinant eNOS protein as well as in vitro transcribed (35)S-labeled eNOS from solution indicating a direct interaction between the proteins in vitro. Scatchard analysis of binding studies demonstrates an equilibrium dissociation constant (K(d)) of 27.6 nm. Incubation of purified recombinant eNOS protein with GST-dynamin-2 significantly increases eNOS activity as does overexpression of dynamin-2 in ECV 304 cells stably transfected with eNOS-green fluorescent protein. These studies demonstrate a direct protein-protein interaction between eNOS and dynamin-2, thereby identifying a new NOS-associated protein and providing a novel function for dynamin. These events may have relevance for eNOS regulation and trafficking within vascular endothelium.

Health effects of fluoride pollution caused by coal burning

Recently a huge amount of fluoride in coal has been released into indoor environments by the combustion of coal and fluoride pollution seems to be increasing in some rural areas in China. Combustion of coal and coal bricks is the primary source of gaseous and aerosol fluoride and these forms of fluoride can easily enter exposed food products and the human respiratory tract. Major human fluoride exposure was caused by consumption of fluoride contaminated food, such as corn, chilies and potatoes. For each diagnostic syndrome of dental fluorosis, a log-normal distribution was observed on the logarithm of urinary fluoride concentration in students in China. Urinary fluoride content was found to be a primary health indicator of the prevalence of dental fluorosis in the community. In the fluorosis areas, osteosclerosis in skeletal fluorosis patients was observed with a high prevalence. A biochemical marker of bone resorption, urinary deoxypyridinoline content was much higher in residents in China than in residents in Japan. It was suggested that bone resorption was stimulated to a greater extent in residents in China and fluoride may stimulate both bone resorption and bone formation. Renal function especially glomerular filtration rate was very sensitive to fluoride exposure. Inorganic phosphate concentrations in urine were significantly lower in the residents in fluorosis areas in China than in non-fluorosis area in China and Japan. Since airborne fluoride from the combustion of coal pollutes extensively both the living environment and food, it is necessary to reduce fluoride pollution caused by coal burning.

[Purification and properties of neutral phytase form Bacillus subtilis]

A strain Bacillus subtilis producing neutral phytase was screened from soil. The protein of phytase was purified by HPLC. Optimal pH value and temperature of the phytase for its activity were 7.5 and 55 degrees C, respectively. The Km values of the phytase for dodecasodium phytate under 37 degrees C was 0.19 mmol/L. The molecule weight of the phytase protein was determined as about 45 kD by SDS-PAGE. The N-terminal amino acids sequence of the phytase protein was determined as Lys-His-Lys-Leu-Ser-Asp-Pro-Tyr-His-Phe-Thr by amino acids sequence analysis.

N'-tert-Butyl-N'-aroyl-N-(alkoxycarbonylmethyl)-N-aroylhydrazines, a novel nonsteroidal ecdysone agonist: syntheses, insecticidal activity, conformational, and crystal structure analysis

Seventeen N'-tert-butyl-N'-aroyl-N-(alkoxycarbonylmethyl)-N-aroylhydrazines were synthesized, and their insecticidal activities against armyworm (Leucania separata (Walker)) were tested. The conformation and structure of compound 1b was studied by 1H NMR spectroscopy and X-ray crystallography. The crystal structure belongs to the orthorhombic system and the N—N bond adopts a gauche conformation, which was assumed to be the active conformation, with a dihedral angle of 69.9°.Key words: N'-tert-butyl-N'-aroyl-N-(alkoxycarbonylmethyl)-N-aroylhydrazine, syntheses, insecticidal activity, conformation, crystal structure.

Irinotecan in the treatment of colorectal cancer: clinical overview

PURPOSE AND METHODS

For more than three decades, the therapeutic options for patients with advanced colorectal cancer have almost exclusively been based on fluoropyrimidines. With the recognition that topoisomerase-I (TOP-I) is an important therapeutic target in cancer therapy, irinotecan, a semisynthetic TOP-I-interactive camptothecin derivative, has been clinically established in the treatment of colorectal cancer.

RESULTS

Irinotecan was investigated as second-line chemotherapy after prior treatment with fluorouracil (FU)-based regimens in two large randomized phase III trials comparing irinotecan with either best supportive care or an infusional FU/leucovorin (LV) regimen. The outcomes of these trials established irinotecan as the standard therapy in the second-line treatment of colorectal cancer. The therapeutic value of irinotecan in the first-line treatment of metastatic colorectal cancer was investigated in two large randomized phase III trials comparing the combination of irinotecan and FU/LV with FU/LV alone. Both trials demonstrated significant superior efficacy for the combination of irinotecan and FU/LV in terms of response rate, median time to disease progression, and median survival time. Consequently, the combination of irinotecan and FU/LV has been approved as first-line chemotherapy for patients with metastatic colorectal cancer and constitutes the reference therapy against which other treatment options must be tested in the future.

CONCLUSION

In this review, the clinical rationale and update of the present clinical status of irinotecan in the treatment of colorectal cancer and future prospects of irinotecan-based combinations are discussed.

[Transfection of wild-type p14ARF gene leads to growth inhibition of human lung cancer cell lines]

BACKGROUND

To examine whether wild-type p14ARF gene is a candidate suppressor gene for lung cancer.

METHODS

Human lung cancer cell lines having various endogenous backgrounds in INK4a, p53 and Rb genes were used as the recipients of the wild-type p14ARF gene. The expression of p14ARF mRNA and protein was detected with RT-PCR, immunohistochemistry and Western blot after G418 selection. Clones which expressed both p14ARF mRNA and protein were identified and selected for further experiements. By comparing with the parental and negative control cells treated with empty vectors, the effects of exogenously transfected p14ARF on cell division rate, cell cycle distribution and morphologic alteration were analyzed. In vivo evaluation of the growth rate was also made with the experiment of nude mice tumor formation.

RESULTS

Upon transfection with p14ARF gene, cells were arrested at G1 or G1/G2 phase of cell cycle in three wtp53 lung cancer cell lines and their proliferation rates were also inhibited.

CONCLUSIONS

Human wild-type p14ARF gene has suppressive effect on abnormal proliferation of lung cancer cells, especially in some wtp53 lung cancer cells, and it might be an ideal candidate for gene therapy of human lung cancer.

Gene transfer of recombinant endothelial nitric oxide synthase to liver in vivo and in vitro

Endothelial nitric oxide synthase (eNOS)-derived nitric oxide (NO) contributes to hepatic vascular homeostasis. The aim of this study was to examine whether delivery of an adenoviral vector encoding eNOS gene to liver affects vasomotor function in vivo and the mechanism of NO production in vitro. Rats were administered adenoviruses encoding beta-galactosidase (AdCMVLacZ) or eNOS (AdCMVeNOS) via tail vein injection and studied 1 wk later. In animals transduced with AdCMVLacZ, beta-galactosidase activity was increased in the liver, most prominently in hepatocytes. In AdCMVeNOS-transduced animals, eNOS protein levels and catalytic activity were significantly increased. Overexpression of eNOS diminished baseline perfusion pressure and constriction in response to the alpha(1)-agonist methoxamine in the perfused liver. Transduction of cultured hepatocytes with AdCMVeNOS resulted in the targeting of recombinant eNOS to a perinuclear distribution and binding with the NOS-activating protein heat shock protein 90. These events were associated with increased ionomycin-stimulated NO release. In summary, this is the first study to demonstrate successful delivery of the recombinant eNOS gene to liver in vivo and in vitro with ensuing NO production.

Preclinical development of eniluracil: enhancing the therapeutic index and dosing convenience of 5-fluorouracil

Eniluracil (5-ethynyluracil, GW 776, 776C85) is being developed as a novel modulator of 5-fluorouracil (5-FU) for the treatment of cancer. Eniluracil is an effective mechanism-based inactivator of dihydropyrimidine dehydrogenase (DPD), the first enzyme in the catabolic pathway of 5-FU. By temporarily eliminating this prevalent enzyme, eniluracil provides predictable dosing of 5-FU and enables oral administration of 5-FU to replace intravenous bolus and continuously infused dosing. New DPD is synthesized with a half-life of 2.6 days. It also eliminates the formation of problematic 5-FU catabolites. Most importantly, in laboratory animals, eniluracil increases the therapeutic index and absolute efficacy of 5-FU. Accompanying reports in this journal indicate that eniluracil has promising clinical potential.