Detection of oncogenic mutations in the EGFR gene in lung adenocarcinoma with differential sensitivity to EGFR tyrosine kinase inhibitors

The complete sequencing of the human genome and the development of molecularly targeted cancer therapy have promoted efforts to identify systematically the genetic alterations in human cancer. By high-throughput sequencing of tyrosine kinase genes in human non-small-cell lung cancer, we identified somatic mutations in the kinase domain of the epidermal growth factor receptor tyrosine kinase gene (EGFR) that are correlated with clinical response to EGFR tyrosine kinase inhibitors (TKIs). We have shown that these mutant forms of EGFR induce oncogenic transformation in different cellular systems. Cells whose growth depends on EGFR with mutations in exons 19 and 21 are sensitive to EGFR-TKIs, whereas cells expressing insertion mutations in exon 20 or the T790M point mutant, found in tumor biopsies from patients that relapsed after an initial response to EGFR-TKIs, are resistant. Furthermore, by applying a novel, massively parallel sequencing technology, we have shown that clinically relevant oncogene mutations can be detected in clinical specimens with very low tumor content, thereby enabling optimal patient selection for mutation-directed therapy. In summary, by applying high-throughput genomic resequencing, we have identified a novel therapeutic target, mutant EGFR, in lung cancer and evaluated its role in predicting response to targeted therapy.

Oxybutynin Extended Release and Tolterodine Immediate Release

OBJECTIVE

To evaluate the cost-effectiveness of a new extended-release (XL) formulation of oxybutynin relative to tolterodine immediate release (IR), currently the most prescribed treatment for overactive bladder in the UK.

METHODS

A state-transition model was developed to compare outcomes over 1 year. Effectiveness and treatment persistence data were derived from the OBJECT (Overactive Bladder: Judging Effective Control and Treatment) study, a 3-month clinical trial comparing oxybutynin XL 10 mg/day with tolterodine IR 4 mg/day. The daily costs of oxybutynin XL and tolterodine IR were pound0.82 and pound1.04, respectively. These data and information from the literature were used to project outcomes beyond the trial time. Severity-specific incontinence cost profiles were developed for the UK (2002 costings).

RESULTS

After 1 year, 3.1 more patients per 100 treated attained complete continence with oxybutynin XL compared with tolterodine IR, and 5.6% more had less than seven incontinent episodes per week. Over 1 year, patients receiving oxybutynin XL had almost 17 additional incontinence-free days and 95 fewer incontinent episodes. Estimated costs were pound86 lower per patient with oxybutynin XL. If drugs are priced equally, savings decrease to pound21 per patient. Oxybutynin XL maintains its advantage over wide ranges of inputs, and outcomes are similar if analyses are limited to 3 months.

CONCLUSION

Base-case analyses suggest that oxybutynin XL provides better effectiveness than tolterodine IR and reduces costs. Results indicate that oxybutynin XL is the dominant therapeutic option under a wide range of alternative inputs and assumptions.

[Clinical value of the symptom-relieving operation in multimodality therapy of stage IIIB and IV lung cancer]

BACKGROUND

To explore the clinical value of the symptom-relieving operation in multimodality therapy of stage IIIB and IV lung cancer for rising quality of life and prolonging survival time.

METHODS

The pain incidence rate, fraction of Karnofsky and anesthesia, clinical effect of treatment and survival rate of 29 cases were statistically analysed using SPSS software, in multimodality therapy of stage IIIB and IV lung cancer, before and after symptom-relieving operation. The difference between before and after operation was compared with Chi-Square and t test. The survival rate was calculate with Kaplan-Meier method.

RESULTS

The complete remission rate for cases of malignant pleural effusion and pericardial effusion was 100% ( 15/ 15) . The 1-year survival rate was 66. 67%, mean survival time was 13. 81± 1. 61 months, and median survival time was 16. 00 months. The 1-year survival rate of cases with bone metastasis was 20. 0%, mean survival time was 9. 90± 0. 99 months, median survival time was 10. 00 months. After therapy, the pain incidence rate of all patients was decreased from 89. 7% to 34. 5% ( P < 0. 001) ; Karnofsky score was increased from 58. 28 ± 2. 17 to 82. 41± 1. 54( P < 0. 001) ; fraction of anesthesia was decreased from 5. 17± 0. 53 to 1. 45± 0. 38 ( P < 0. 001) .

CONCLUSIONS

The symptom-relieving operation for metastasis lesion can rise the quality of life, prolong survival time, decrease dependence of anesthetic and analgesic drugs in multimodality therapy of stage IIIB and IV lung cancer.

Variations in prescribing practices for novel antipsychotic medications among Veterans Affairs hospitals

This study examined prescribing practices for antipsychotic medications at 13 Veterans Affairs (VA) medical centers and whether patients' sociodemographic characteristics were associated with receiving novel agents. Automated pharmacy data were used to identify 599 patients who had been diagnosed as having schizophrenia and who had received a prescription for an antipsychotic medication after their last discharge from a VA medical center in 1997. Novel antipsychotics were found to have been prescribed for almost half of the patients (47 percent). In logistic regression analysis, significant variations in prescription of novel agents were found among the facilities and among ethnic groups. The results of this study suggest that prescribing practices are influenced by both facility and patient characteristics.

Antitumor action of the PKC activator gnidimacrin through cdk2 inhibition

Daphnane-type diterpene gnidimacrin (NSC252940), isolated from a Chinese plant, exhibited antitumor activity against murine leukemias and solid tumors. At concentrations of 10(-9) to 10(-10) M, this agent strongly inhibited the growth of human tumor cell lines. In sensitive human leukemia K562 cells, gnidimacrin is a PKC activator that arrests the cell cycle in the G(1) phase by inhibiting cdk2 activity. A 4 hr exposure of K562 cells to gnidimacrin induced the CDK inhibitor p21(WAF1/Cip1), but this effect was transient and did not correlate temporally with the onset of G(1) arrest. Expression of cdc25A, a phosphatase that activates cdk2, was reduced during 24-hr exposure to gnidimacrin. Moreover, the suppression corresponded in a concentration- and time-dependent manner to both the inhibition of cdk2 activity and the mobility shift observed when cdk2 was electrophoresed on SDS-PAGE, indicating that the phosphorylation state of cdk2 must change. Cyclin E, the other regulator of cdk2 activity, was not influenced by gnidimacrin. These results suggest that gnidimacrin exerts antitumor activity through suppression of cdc25A and inhibition of cdk2 activity.

Correction of the retinal dystrophy phenotype of the RCS rat by viral gene transfer of Mertk

The Royal College of Surgeons (RCS) rat is a widely studied animal model of retinal degeneration in which the inability of the retinal pigment epithelium (RPE) to phagocytize shed photoreceptor outer segments leads to a progressive loss of rod and cone photoreceptors. We recently used positional cloning to demonstrate that the gene Mertk likely corresponds to the retinal dystrophy (rdy) locus of the RCS rat. In the present study, we sought to determine whether gene transfer of Mertk to a RCS rat retina would result in correction of the RPE phagocytosis defect and preservation of photoreceptors. We used subretinal injection of a recombinant replication-deficient adenovirus encoding rat Mertk to deliver the gene to the eyes of young RCS rats. Electrophysiological assessment of animals 30 days after injection revealed an increased sensitivity of treated eyes to low-intensity light. Histologic and ultrastructural assessment demonstrated substantial sparing of photoreceptors, preservation of outer segment structure, and correction of the RPE phagocytosis defect in areas surrounding the injection site. Our results provide definitive evidence that mutation of Mertk underlies the RCS retinal dystrophy phenotype, and that the phenotype can be corrected by treatment of juvenile animals. To our knowledge, this is the first demonstration of complementation of both a functional cellular defect (phagocytosis) and a photoreceptor degeneration by gene transfer to the RPE. These results, together with the recent discovery of MERTK mutations in individuals with retinitis pigmentosa, emphasize the importance of the RCS rat as a model for gene therapy of diseases that arise from RPE dysfunction.

Tissue contents and subcellular distribution of chromium and other trace metals in experimental diabetic rats after intravenous injection of Cr 50-enriched stable isotopic tracer solution

In order to study the metabolism of essential trace elements in diabetics, we studied alloxan-diabetic rats for the distribution patterns of chromium (Cr), cobalt (Co), iron (Fe), selenium (Se), and zinc (Zn) in the liver, kidney, pancreas, and testes, as well as in the organ subcellular fractions. Normal rats were used as controls. Cr 50-enriched stable isotopic tracer solution was given by intravenous injection to avoid the difficulties of estimation of Cr status. Our data show that the concentrations of Zn in liver and kidney, of Co, Fe, and Zn in pancreas, and of Fe and Zn in testes of the diabetic rats were significantly higher than in the control rats. Nevertheless, the concentrations of Cr in pancreas, Fe in kidney, and Cr and Se in testes of the diabetic rats were significantly lower than in the controls. Furthermore, we observed significant alterations of element concentrations in subcellular fractions of various organs in the diabetic rats. These results suggest that changing hormone levels may interfere with the accumulation of some trace elements both in the organs and in the subcellular fractions of rats.

The impact of problem drinking on employment

Social cost studies report that alcohol use and misuse impose a great economic burden on society, and over half of the total economic costs are estimated to be due to the loss of work productivity. Controversy remains, however, as to the magnitude and direction of the effects of alcohol consumption on productivity. Furthermore, most of the studies have looked at the relationship between problem drinking and wages. This paper investigates the impact of problem drinking on employment by analysing a random sample of men and women of prime working age from six Southern states in the US (Alabama, Arkansas, Georgia, Louisiana, Mississippi and Tennessee). The data set contains 4898 females and 3224 males, with information on both employment and problem drinking. To eliminate the bias that may result from single-equation estimation, we used a bivariate probit model to control for possible correlation in the unobservable factors that affect both problem drinking and employment. We find no significant negative association between problem drinking and employment for both men and women, controlling for other covariates. The findings are consistent with other research and highlight several methodological issues. Furthermore, the study suggests that estimates of the costs of problem drinking may be overstated owing to misleading labour supply relationships.

Functional roles of the tyrosine within the NP(X)(n)Y motif and the cysteines in the C-terminal juxtamembrane region of the CB2 cannabinoid receptor

In G protein-coupled receptors, a NP(X)(n)Y motif in the seventh transmembrane domain and cysteine residues in the C-terminal juxtamembrane region are conserved. In the current study, the roles of Y299 within the NPVIY motif and C313 and C320 in the C-terminal juxtamembrane region of the human CB2 cannabinoid receptor were investigated by site-directed mutagenesis. Replacing Y299 with alanine resulted in a complete loss of ligand binding and a severe impairment of cannabinoid-induced inhibition of forskolin-stimulated cAMP accumulation. The C313A and C320A mutations markedly reduced functional coupling to adenylate cyclase, but had no effect on ligand binding and agonist-induced receptor desensitization.

Schizosaccharomyces pombe cells lacking the amino-terminal catalytic domains of DNA polymerase epsilon are viable but require the DNA damage checkpoint control

In Schizosaccharomyces pombe, the catalytic subunit of DNA polymerase epsilon (Pol epsilon) is encoded by cdc20(+) and is essential for chromosomal DNA replication. Here we demonstrate that the N-terminal half of Pol epsilon that includes the highly conserved polymerase and exonuclease domains is dispensable for cell viability, similar to observations made with regard to Saccharomyces cerevisiae. However, unlike budding yeast, we find that fission yeast cells lacking the N terminus of Pol epsilon (cdc20(DeltaN-term)) are hypersensitive to DNA-damaging agents and have a cell cycle delay. Moreover, the viability of cdc20(DeltaN-term) cells is dependent on expression of rad3(+), hus1(+), and chk1(+), three genes essential for the DNA damage checkpoint control. These data suggest that in the absence of the N terminus of Pol epsilon, cells accumulate DNA damage that must be repaired prior to mitosis. Our observation that S phase occurs more slowly for cdc20(DeltaN-term) cells suggests that DNA damage might result from defects in DNA synthesis. We hypothesize that the C-terminal half of Pol epsilon is required for assembly of the replicative complex at the onset of S phase. This unique and essential function of the C terminus is preserved in the absence of the N-terminal catalytic domains, suggesting that the C terminus can interact with and recruit other DNA polymerases to the site of initiation.

Structural characterization of the oxidative degradation products of an antifungal agent SCH 56592 by LC–NMR and LC–MS

LC-NMR and LC-MS were used to characterize the structures of four major degradation products of SCH 56592, an antifungal drug candidate in clinical trials. These compounds were formed under stress conditions in which the bulk drug substance was heated in air at 150 degrees C for 12 days, and were separated from SCH 56592 as a mixture using a semi-preparative HPLC method. The data from LC-NMR, LC-ESI-MS (electrospray ionization mass spectrometry) and LC-ESI-MS/MS indicate that the oxidation occurred at the piperazine ring in the center of the drug molecule. The structures of the degradation products were determined from the 1H NMR spectra obtained via LC-NMR, which were supported by LC-ESI-MS and LC-ESI-MS/MS analyses. A novel degradation pathway of SCH 56592 was proposed based on these characterized structures.

Definition of the surface in the thyroid hormone receptor ligand binding domain for association as homodimers and heterodimers with retinoid X receptor

Thyroid hormone receptors (TRs) bind as homodimers or heterodimers with retinoid X receptors (RXRs) to DNA elements with diverse orientations of AGGTCA half-sites. We performed a comprehensive x-ray crystal structure-guided mutation analysis of the TR ligand binding domain (TR LBD) surface to map the functional interface for TR homodimers and heterodimers with RXR in the absence and/or in the presence of DNA. We also identified the molecular contacts in TR LBDs crystallized as dimers. The results show that crystal dimer contacts differ from those found in the functional studies. We found that identical TR LBD residues found in helices 10 and 11 are involved in TR homodimerization and heterodimerization with RXR. Moreover, the same TR LBD surface is operative for dimerization with direct repeats spaced by 4 base pairs (DR-4) and with the inverted palindrome spaced by 6 base pairs (F2), but not with TREpal (unspaced palindrome), where homodimers appear to be simply two monomers binding independently to DNA. We also demonstrate that interactions between the TR and RXR DNA binding domains stabilize TR-RXR heterodimers on DR-4. The dimer interface can be functional in the cell, because disruption of key residues impairs transcriptional activity of TRs mediated through association with RXR LBD linked to GAL4 DNA-binding domain.

A bioactive metabolite of benzo[a]pyrene, benzo[a]pyrene-7,8-dione, selectively alters microsomal Ca2+ transport and ryanodine receptor function

Polycyclic aromatic hydrocarbons are environmental pollutants known to be carcinogenic and immunotoxic. In intact cell assays, benzo[a]pyrene (B[a]P) disrupts Ca(2+) homeostasis in both immune and nonimmune cells, but the molecular mechanism is undefined. In this study, B[a]P and five metabolites are examined for their ability to alter Ca(2+) transport across microsomal membranes. Using a well-defined model system, junctional SR vesicles from skeletal muscle, we show that a single o-quinone metabolite of B[a]P, B[a]P-7,8-dione, can account for altered Ca(2+) transport across microsomal membranes. B[a]P-7,8-dione induces net Ca(2+) release from actively loaded vesicles in a dose-, time-, and Ca(2+)-dependent manner. In the presence of 5 microM extravesicular Ca(2+), B[a]P-7,8-dione exhibited threshold and EC(50) values of 0.4 and 2 microM, respectively, and a maximal release rate of 2 micromol of Ca(2+) min(-1) mg(-1). The mechanism by which B[a]P-7,8-dione enhanced Ca(2+) efflux was further investigated by measuring macroscopic fluxes and single RyR1 channels reconstituted in bilayer lipid membranes and direct measurements of SERCA catalytic activity. B[a]P-7,8-dione (< or = 20 microM) had no measurable effect on initial rates of Ca(2+) accumulation in the presence of ruthenium red to block ryanodine receptor (RyR1), nor did it alter Ca(2+)-dependent (thapsigargin-sensitive) ATPase activity. B[a]P-7,8-dione selectively altered the function of RyR1 in a time-dependent diphasic manner, first activating then inhibiting channel activity. Considering that RyR1 and its two alternate isoforms are broadly expressed in mammalian cells and their important role in Ca(2+)-signaling, the present results reveal a mechanism by which metabolic bioactivation of B[a]P may mediate RyR dysfunction of pathophysiological significance.

Monitoring end-tidal carbon dioxide during weaning from cardiopulmonary bypass in patients without significant lung disease

End-tidal carbon dioxide tension (PETCO(2)) changes with fluctuations in cardiac output (CO). We compared PETCO(2) to pulmonary artery blood flow (PAQt) during weaning from cardiopulmonary bypass (CPB) in normothermic patients without significant pulmonary disease. Fifteen consecutive adult cardiac surgical patients were prospectively studied during and shortly after weaning from CPB. Before separation from CPB, PETCO(2) and PAQt were measured, the latter by transesophageal Doppler echocardiography. At the time of measurements patients were normothermic, and ventilated at 6 breaths/min with tidal volumes of 10 mL/kg. After separation from CPB, thermodilution cardiac output (TDCO) was measured in addition to PAQt and PETCO(2). Regression and bias analyses were used to compare PETCO(2), PAQt, and TDCO. Seventy measurements were recorded; 31 before separation from CPB and 39 after separation from CPB. A good correlation was seen between PAQt and PETCO(2) (r = 0.88) and between TDCO and PAQt (r = 0.93; mean bias 0.03 L/min; SD 0.52 L/min). The regression analysis of PAQt on PETCO(2) showed greater variability at PETCO(2) levels > 34 mm Hg (n = 22; r = 0.14). Increases in PETCO(2) plateaued at this level, although PAQt continued to increase. When PETCO(2) was more than 30 mm Hg, all PAQt and TDCO values were >4.0 L/min (>2.0 L/min/m(2)). When PETCO(2) exceeded 34 mm Hg, all values of PAQt, and 28/29 values of TDCO were more than 5 L/min (>2.5 L/min/m(2)). One patient had TDCO of 4.69 L/min (2.39 L/min/m(2)). In normothermic patients without significant pulmonary disease, PETCO(2) is a useful index of PAQt during separation from CPB. Under the clinical settings in this study, a PETCO(2) greater than 30 mm Hg was invariably associated with a CO more than 4.0 L/min or a cardiac index >2.0 L/min/m(2).

Influence of overlying tissue and probe geometry on the sensitivity of a near-infrared tissue oximeter

In this paper, the influences of overlying tissue and detecting distance between the source and the detector on the measurement of a tissue oximeter were discussed. The signal-noise-ratio of the detector was also examined. A semi-infinite multi-layer Monte Carlo model was induced to simulate the migration of the photons in the skin, adipose and muscle. The thickness of the adipose layer and the separation between the source and the detector in the muscle were changed to simulate the clinical application. Partial pathlength was introduced as a characteristic parameter to evaluate the sensitivity of the oximeter. A two-wavelength (700 and 830 nm) tissue oximeter was developed to verify the results of the simulation. The Monte Carlo simulation results showed that the sensitivity of the near infrared spectroscopy (NIRS) oximeter declined greatly with increasing overlying tissue thickness. Increasing the distance between the light source and the detector improved the sensitivity. However, in order to achieve a sufficiently high signal-to-noise ratio, it was necessary to limit this distance. The results of a bicycle ergometer exercise verified the above results and showed that, for a special adipose thickness (AT), there may be a reasonable range of the emitter-detector separation.

Winner take all experts network for sensor validation

The validation of sensor measurements has become an integral part of the operation and control of modern industrial equipment. The sensor under harsh environment must be shown to consistently provide the correct measurements. Analysis of the validation hardware or software should trigger an alarm when the sensor signals deviate appreciably from the correct values. Neural network based models can be used to on-line estimate critical sensor values when neighboring sensor measurements are used as inputs. The underlying assumption is that the neighboring sensors share an analytical relationship. The discrepancy between the measured and predicted sensor values may then be used as an indicator for sensor health. The proposed Winner Take All Experts (WTAE) network based on a 'divide and conquer' strategy significantly reduces the computational time required to train the neural network. It employs a growing fuzzy clustering algorithm to divide a complicated problem into a series of simpler sub-problems and assigns an expert to each of them locally. After the sensor approximation, the outputs from the estimator and the real sensor readings are compared both in the time domain and the frequency domain. Three fault indicators are used to provide analytical redundancy to detect the sensor failure. In the decision stage, the intersection of three fuzzy sets accomplishes a decision level fusion, which indicates the confidence level of the sensor health. Two data sets, the Spectra Quest Machinery Fault Simulator data set and the Westland vibration data set, were used in simulations to demonstrate the performance of the proposed WTAE network. The simulation results show the proposed WTAE is competitive with or even superior to the existing approaches.

Elements in erythrocytes of population with different thyroid hormone status

The contents of elements K, Ca, Fe, Cu, Zn, Se, and Rb in erythrocytes of 78 cases with different thyroid hormone status have been measured by proton-induced X-ray emission and neutron activation analysis. According to the status of thyroid hormones T3, T4, TSH, FT3, and FT4 detected by radioimmunoassay, the experiment subjects were divided into four groups (i.e., hyperthyroid, hypothyroid, critical [one of thyroid hormones was abnormal], and normal). Elements contents and hormones levels of four groups were analyzed by one-way analysis of variance and correlation using an SPSS/PC statistical package. The results showed that the Se contents of four groups were not significantly different (p<0.05). Zn content of hypothyroid group was significantly higher than those of hyperthyroid and critical groups. The Zn content of the normal group was higher than that of the hypothyroid group and lower than that of the hyperthyroid and critical groups. In the hyperthyroid group, there were significant correlations between elements contents and thyroid hormones levels (except TSH), but not between elements contents and levels of thyroid hormones. However, in the hypothyroid group, relatively strong correlations have been found between elements contents and thyroid hormones levels, especially between Zn and the T3/T4 ratio, and between Zn and TSH.

Potentiation of estrogen receptor activation function 1 (AF-1) by Src/JNK through a serine 118-independent pathway

Estrogen receptor (ER) is activated either by ligand or by signals from tyrosine kinase-linked cell surface receptors. We investigated whether the nonreceptor Src tyrosine kinase could affect ER activity. Expression of constitutively active Src or stimulation of the endogenous Src/JNK pathway enhances transcriptional activation by the estrogen-ER complex and strongly stimulates the otherwise weak activation by the unliganded ER and the tamoxifen-ER complex. Src affects ER activation function 1 (AF-1), and not ER AF-2, and does so through its tyrosine kinase activity. This effect of Src is mediated partly through a Raf/mitogen-activated ERK kinase/extracellular signal-regulated kinase (Raf/MEK/ERK) signaling cascade and partly through a MEKK/JNKK/JNK cascade. Although, as previously shown, Src action through activated ERK stimulates AF-1 by phosphorylation at S118, Src action through activated JNK neither leads to phosphorylation of S118 nor requires S118 for its action. We therefore suggest that the Src/JNK pathway enhances AF-1 activity by modification of ER AF-1-associated proteins. Src potentiates activation functions in CREB-binding protein (CBP) and glucocorticoid receptor interacting protein 1 (GRIP1), and we discuss the possibility that the Src/JNK pathway enhances the activity of these coactivators, which are known to mediate AF-1 action.

Transmembrane redox sensor of ryanodine receptor complex

Inositol 1,4,5-trisphosphate receptors (IP(3)R) and ryanodine receptors (RyR) mediate the release of endoplasmic and sarcoplasmic reticulum (ER/SR) Ca(2+) stores and regulate Ca(2+) entry through voltage-dependent or ligand-gated channels of the plasma membrane. A prominent property of ER/SR Ca(2+) channels is exquisite sensitivity to sulfhydryl-modifying reagents. A plausible role for sulfhydryl chemistry in physiologic regulation of Ca(2+) release channels and the fidelity of Ca(2+) release from ER/SR is lacking. This study reveals the existence of a transmembrane redox sensor within the RyR1 channel complex that confers tight regulation of channel activity in response to changes in transmembrane redox potential produced by cytoplasmic and luminal glutathione. A transporter selective for glutathione is co-localized with RyR1 within the SR membrane to maintain local redox potential gradients consistent with redox regulation of ER/SR Ca(2+) release. Hyperreactive sulfhydryls previously shown to reside within the RyR1 complex (Liu, G., and Pessah, I. N. (1994) J. Biol. Chem. 269, 33028-33034) are an essential biochemical component of a transmembrane redox sensor. Transmembrane redox sensing may represent a fundamental mechanism by which ER/SR Ca(2+) channels respond to localized changes in transmembrane glutathione redox potential produced by physiologic and pathophysiologic modulators of Ca(2+) release from stores.

Activation of lytic Epstein-Barr virus (EBV) infection by radiation and sodium butyrate in vitro and in vivo: a potential method for treating EBV-positive malignancies

The consistent presence of the EBV genome in certain tumors offers the potential for novel EBV-directed therapies. Switching the latent form of EBV infection present in most EBV-positive tumor cells into the cytolytic form may be clinically useful because lytic EBV infection leads to host cell destruction, and very few normal cells contain the EBV genome. It would also be therapeutically advantageous to induce expression of EBV-encoded lytic proteins that convert the nucleoside analogues ganciclovir (GCV) and 3'-azido-3'deoxythymidine (AZT) into their active, cytotoxic forms. In this report, we have explored two different approaches for activating the lytic form of EBV infection in tumors. We show that gamma-irradiation at clinically relevant doses induces lytic EBV infection in lymphoblastoid cell lines in vitro as well as in EBV-positive B-cell tumors in SCID mice. In addition, sodium butyrate (given as a single i.p. dose) is effective for activating lytic viral infection in some EBV tumor types in SCID mice. We also examined whether low-dose gamma-irradiation treatment of EBV-positive lymphoblastoid cells in vitro promotes GCV or AZT susceptibility. The combination of radiation with either GCV or AZT induced significantly more cell killing in vitro than either radiation or prodrug treatment alone. Most importantly, we found that the combination of gamma-irradiation and GCV was much more effective in treating EBV-positive lymphoblastoid tumors in SCID mice than either agent alone. Thus, GCV or AZT treatment could potentially enhance the therapeutic efficacy of radiation therapy for EBV-positive lymphomas in patients.

Photochemistry of hydrolytic iron (III) species and photoinduced degradation of organic compounds. A minireview

On the basis of the research literature of the last fifty years, we have reviewed the photochemical properties of different hydrolytic Fe(III) species and the photodegradation of organic compounds in aqueous solutions initiated by them (mainly including low-molecular-weight Fe(III)-OH complexes, Fe(III) oxides (Fe2O3) and Fe(III) hydroxides (FeOOH)). Furthermore, the feasibility and prospects of the novel photochemical methods of using Fe(III) salts and oxides in wastewater treatments are being discussed in this paper.

Degradation mechanism of azo dye C. I. reactive red 2 by iron powder reduction and photooxidation in aqueous solutions

We have made a comparison of the UV-VIS spectra of three azo dyes, C. I. reactive red 2, orange II and C. I. reactive black 8, in aqueous solutions during treatment with iron powder reduction and photooxidation. From this, we propose their mechanisms for reduction photooxidation. GC/MS analyses of the degradation products of the dye C. I. reactive red 2 demonstrated some important steps producing hydrogenated azo structure, substituted benzene and substituted naphthalene.

[Pre- and post-operative sequential changes of serum p53 antibodies and clinical significance in patients with lung cancer]

BACKGROUND

To explore the relationship between serum p53 antibodies and clinicopathological characteristics in patients with lung cancer and to investigate sequential changing regularity of serump53 antibodies after surgical resection.

METHODS

The serum p53 antibody level was detected in 120 patients with lung cancer , and in 30 patients with benign pulmonary lesion and 120 healthy adults as control by enzyme linked immunosorbent assay ( ELISA) . The blood samples were collected on the day before operation and on the 7th , 30th and 90th days postoperatively.

RESULTS

The level and positive rate of serum p53 antibodies in patients with lung cancer were significantly higher than those in patients with benign pulmonary disease and normal individuals ( P < 0. 05) , but there was no significant difference between patients with benign pulmonary disease and normal individuals ( P > 0. 05) . The level and positive rate of pre-operative serum p53 antibodies in patients with lung cancer were closely related to cell differentiation and stage of lung cancer ( P < 0. 01 or P < 0. 05) . The level of serum p53 antibodies decreased gradually in patients with lung cancer underwent radical removal of the cancer , and completely returned to the normal level around the 30th day after operation , but the level of serum p53 antibodies in patients with lung cancer underwent palliative operation didn't reduce to the normal level on the 30th day after operation. It would increase again when tumor metastasis or recurrence developed.

CONCLUSIONS

Detection of serum p53 antibodies is helpful to defferentiate benign from malignant pulmonary diseases. Monitoring of sequential change of pre- and post-operative serum p53 antibodies in patients with lung cancer is helpful to evaluate response to treatment , to judge prognosis and to guide the comprehensive treatment of patients with lung cancer after operation.

Effect of endurance training on lipid metabolism in women: a potential role for PPARalpha in the metabolic response to training

Endurance training increases fatty acid oxidation (FAO) and skeletal muscle oxidative capacity. However, the source of the additional fat and the mechanisms for increasing FAO capacity in muscle are not clear. We measured whole body and regional lipolytic activity and whole body and plasma FAO in six lean women during 90 min of bicycling exercise (50% pretraining peak O(2) consumption) before and after 12 wk of endurance training. We also assessed skeletal muscle content of peroxisome proliferator-activated receptor-alpha (PPARalpha) and its target proteins that regulate FAO [medium-chain and very long chain acyl-CoA dehydrogenase (MCAD and VLCAD)]. Despite a 25% increase in whole body FAO during exercise after training (P < 0.05), training did not alter regional adipose tissue lipolysis (abdominal: 0.56 +/- 0.26 and 0.57 +/- 0.10 micromol x 100 g(-1) x min(-1); femoral: 0.13 +/- 0.07 and 0.09 +/- 0.02 micromol x 100 g(-1) x min(-1)), whole body palmitate rate of appearance in plasma (168 +/- 18 and 150 +/- 25 micromol/min), and plasma FAO (554 +/- 61 and 601 +/- 45 micromol/min). However, training doubled the levels of muscle PPARalpha, MCAD, and VLCAD. We conclude that training increases the use of nonplasma fatty acids and may enhance skeletal muscle oxidative capacity by PPARalpha regulation of gene expression.

[Advances in diagnosis and treatment of ectopic pregnancy during the past ten years]

OBJECTIVE

To investigate the changes of diagnosis and treatment of ectopic pregnancy (EP) during the past ten years.

METHODS

Medical records of 1,970 cases with EP seen in our hospital from Jan. 1987 to Dec. 1996 were collected and analyzed retrospectively.

RESULTS

(1) The incidence of EP increases from 1.0 per 42.4 labours during 1987-1988 to 1.0 per 6.6 labours in 1995-1996. (2) Diagnosis was confirmed more by television laparoscopy, transvaginal ultrasonography and sensitive human chorionic gonadotropin-beta subunit assay rather than loparotomy and with a shorter period, (6.5 +/- 0.7) days in 1987-1988 versus (3.7 +/- 0.2) days in 1995-1996. (3) The choice of treatment was more conservative or through laparoscopic surgery than abdominal salpingectomy. (4) The success rate of conservative surgery expectant management reached 100.0% and medical treatment with a variety of choices around 80.0%-85.%.

CONCLUSIONS

Although the incidence of EP increased, with the improvement of diagnostic approaches, patients were detected at an earlier stage and possible to be treated more conservatively.

Arthropod- and host-specific Borrelia burgdorferi bbk32 expression and the inhibition of spirochete transmission

Antisera to BBK32 (a Borrelia burgdorferi fibronectin-binding protein) and BBK50, two Ags synthesized during infection, protect mice from experimental syringe-borne Lyme borreliosis. Therefore, B. burgdorferi bbk32 and bbk50 expression within Ixodes scapularis ticks and the murine host, and the effect of BBK32 and BBK50 antisera on spirochetes throughout the vector-host life cycle were investigated. bbk32 and bbk50 mRNA and protein were first detected within engorged ticks, demonstrating regulated expression within the vector. Then bbk32 expression increased in mice at the cutaneous site of inoculation. During disseminated murine infection, bbk32 and bbk50 were expressed in several murine tissues, and mRNA levels were greatest in the heart and spleen at 30 days. BBK32 antisera protected mice from tick-borne B. burgdorferi infection and spirochete numbers were reduced by 90% within nymphs that engorged on immunized mice. Moreover, 75% of these ticks did not retain spirochetes upon molting, and subsequent B. burgdorferi transmission by adult ticks was impaired. Larval acquisition of B. burgdorferi by I. scapularis was also inhibited by BBK32 antisera. These data demonstrate that bbk32 and bbk50 are expressed during tick engorgement and that BBK32 antisera can interfere with spirochete transmission at various stages of the vector-host life cycle. These studies provide insight into mechanisms of immunity to Lyme borreliosis and other vector-borne diseases.

Effects of CTx and 8-bromo-cAMP on LPS-induced gene expression of cytokines in murine peritoneal macrophages

LPS, an endotoxin isolated from gram-negative bacterial, has been shown to be a potent cytokine initiator in murine peritoneal macrophages. CAMP-dependent pathway is generally considered to play a suppressive role in immune response. This study investigated the effect of cAMP on LPS-induced gene expression of cytokines in murine macrophages. Our data clearly demonstrated that in LPS-treated macrophages, cAMP elevator (CTx and 8-bromo-cAMP) could increase IL-1Ra and IL-10 gene expression, while mRNAs of IL-1alpha, IL-12, IL-6, and MIF were decreased and other cytokines like IL-1beta, and IFN-gamma did not give a definite tendency. This is the first report that CTx and 8-bromo-cAMP positively regulate IL-1Ra gene expression in LPS-stimulated macrophages. Our data also suggest that a cAMP-dependent pathway may play a regulatory role in Toll-receptor system.

Functional role of hyperreactive sulfhydryl moieties within the ryanodine receptor complex

Several laboratories using chemically heterogeneous sulfhydryl modifying agents have shown that sarcoplasmic reticulum (SR) Ca2+ channels known as ryanodine receptors (RyRs) are especially sensitive to modification of functionally important cysteine residues. The functional consequence of sulfhydryl modification of RyRs can include phases of activation and inhibition that are very much dependent on the concentration of the reagent used, the length of exposure, and the nature of the chemical reaction the reagent undertakes with sulfhydryl groups. Most challenging is understanding the relationship for how specific sulfhydryl moieties ascribe specific aspects of RyR function. Considering the structural complexity of the RyR complex with its associated proteins, this task is likely to be a formidable one. A small number of hyperreactive thiols have been shown to exist within the RyR complex. Their functional role does not appear to impact directly on channel gating. Rather hyperreactive cysteine (Cys) moieties may represent biochemical components of a redox sensor that conveys information about localized changes in redox potential produced by physiologic (e.g., glutathione, nitric oxide) and pathophysiologic (quinones, reactive oxygen species) channel modulators to the Ca2+ release process. The molecular and functional details of such a redox sensor remains to be elucidated.

Modification of ryanodine receptor/Ca2+ release channel with dinitrofluorobenzene

Modification of the ryanodine receptor (RyR)/Ca(2+) release channel with 2,4-dinitrofluorobenzene (DNFB) indicated that two classes of amino group interact with the reagent, as can be distinguished on the basis of their reactivity/accessibility and the effects on ryanodine binding and single channel activities. One group interacted very rapidly (t(1/2)<30 s) at 25 degrees C with low concentrations of DNFB [C(50) (concentration of DNFB required for 50% inhibition or stimulation of ryanodine binding)=5 microM], and at pH values of 6.2 and higher. This interaction resulted in the marked stimulation of ryanodine binding and the complete inhibition of a single Ca(2+) release channel incorporated into planar lipid bilayer. The second group is accessible at higher temperatures (37 degrees C); at pH values higher than 7.4 it reacted slowly (t(1/2)=20 min) with high concentrations of DNFB (C(50)=70 microM). This interaction led to the inhibition of ryanodine binding and single channel activity. Modification of RyR with DNFB under the stimulatory conditions resulted in 3.6-fold and 6-fold increases in ryanodine-binding and Ca(2+)-binding affinities respectively. Modification with DNFB under the inhibitory conditions resulted in a decrease in the total ryanodine-binding sites. The exposure of the RyR single channel to DNFB under both inhibitory and stimulatory conditions led to the complete closure of the channel. However, when modified under the stimulatory conditions, but not under the inhibitory ones, the DNFB-modified closed channel could be re-activated by sub-micromolar concentrations of ryanodine, in the presence of nanomolar concentrations of Ca(2+). The DNFB-modified ryanodine-activated RyR channel showed fast transitions between open, closed and several sub-conductance states, and was completely closed by Ruthenium Red. ATP re-activated the DNFB-modified closed channel or, if present during modification, prevented the inhibition of RyR channel activity by DNFB. Neither the stimulation nor the inhibition of ryanodine binding by modification with DNFB was affected by the presence of ATP. By using the photoreactive ATP analogue 3'-O-(4-benzoyl)benzoyl-[alpha-(32)P]ATP we found that DNFB modification had no effect on the ATP-binding site of RyR. The results are discussed with regard to the involvement of amino group residues in channel gating, ryanodine association/dissociation and occlusion, and the relationship between the open/closed state of the RyR and its capacity to bind ryanodine.

Affinity chromatography of human estrogen receptor-alpha expressed in Saccharomyces cerevisiae. Combination of heparin- and 17beta-estradiol-affinity chromatography

Estrogen receptor-alpha is a member of the nuclear hormone receptor superfamily and is considered as a very important regulatory protein. Human estrogen receptor-alpha has been cloned into Saccharomyces cerevisiae as a fusion to ubiquitin and expression is controlled by a metallothionin promotor. Pilot scale quantities of receptor have been produced by a yeast strain transformed with expression plasmid YEpE13 [Graumann et al., J. Steroid Biochem. Mol. Biol. 57 (1996) 293] in a 14 l stirred tank reactor. The yeast extract contained 2-4 pmol of receptor protein per mg total protein. A purification scheme has been developed using heparin-affinity chromatography combined with affinity chromatography with immobilized 17beta-estradiol 17-hemisuccinate. Heparin-affinity chromatography was very efficient to remove host cell protein. Accompanying proteins that stabilize unoccupied receptor have not been dissociated during elution. The receptor could be purified 5-10-fold in ligand-free state. In contrast to previous reports, we did not find a difference of the binding affinity of liganded and unliganded receptor for heparin immobilized onto Sepharose. The unoccupied receptor could be further purified 100-fold with ligand-affinity chromatography using 17beta-estradiol 17-hemisuccinate-bovine serum albumin-Sepharose. The receptor could be kept in its native state, although saturated with 17beta-estradiol. The purification sequence allows an efficient production of receptor. Further improvement of productivity can be only accomplished by increasing the expression level.

[Determination of 14 elements in chromium-rich brewer's yeast by ICP-AES]

An ICP-AES method was established for the determination of 14 elements in chromium-rich and normal brewer's yeast. The RSDs of two standard reference materials were 0. 5%-3.2% and 0.4%-3.4%, respectively. The results showed that chromium contents could affect the concentrations of other elements in chromium-rich brewer's yeast. The concentrations of K, Mn, P, V, Mg and Ca in chromium-rich brewer's yeast were significantly lower than those in normal brewer's yeast.

[The selection of tympanoplastic type in treating chronic suppurative otitis media]

OBJECTIVE

To investigate the effect of different type of tympanoplasty on chronic suppurative otitis media (CSOM).

METHOD

Myringoplasty, focuses clearance and myringoplasty, focuses clearance and ossiculoplasty and myringoplasty were performed in 189 cases of CSOM.

RESULT

The cure rate of perforation of tympanic membrane with myringoplasty was above 99% accompanied by the varying improvement in acoustic sensibility.

CONCLUSION

Different types of tympanoplasty should be used according to the CSOM. The slighter the pathological changes of CSOM, the more the hearing improve. The better effects was in tympanoplasty of simple type. The tympanic exploration is necessary to be included in tympanoplasty.

Site-selective modification of hyperreactive cysteines of ryanodine receptor complex by quinones

Quinones undergo redox cycling and/or arylation reactions with key biomolecules involved with cellular Ca2+ regulation. The present study utilizes nanomolar quantities of the fluorogenic maleimide 7-diethylamino-3-(4'-maleimidylphenyl)-4-methylcoumarin (CPM) to measure the reactivity of hyperreactive sulfhydryl moieties on sarcoplasmic reticulum (SR) membranes in the presence and absence of quinones by analyzing the kinetics of forming CPM-thioether adducts and localization of fluorescence by SDS-polyacrylamide gel electrophoresis. Doxorubicin, 1,4-naphthoquinone (NQ), and 1, 4-benzoquinone (BQ) are found to selectively and dose-dependently interact with a class of hyperreactive sulfhydryl groups localized on ryanodine-sensitive Ca2+ channels [ryanodine receptor (RyR)], and its associated protein, triadin, of skeletal type channels. NQ and BQ are the most potent compounds tested for reducing the rate of CPM labeling of hyperreactive SR thiols (IC50 = 0.3 and 1.8 microM, respectively) localized on RyR and associated protein. The reduced forms of quinone, tert-butylhydroquinone, and 5-imino-daunorubicin do not alter significantly the pattern or kinetics of CPM labeling up to 100 microM, demonstrating that the quinone group is essential for modulating the state of hyperreactive SR thiols. Nanomolar NQ is shown to enhance the association of [3H]ryanodine for its high-affinity binding site and directly enhance channel-open probability in bilayer lipid membrane in a reversible manner. By contrast, micromolar NQ produces a time-dependent biphasic action on channel function, leading to irreversible channel inactivation. These results provide evidence that nanomolar quinone selectively and reversibly alters the redox state of hyperreactive sulfhydryls localized in the RyR/Ca2+ channel complex, resulting in enhanced channel activation. The Ca2+-dependent cytotoxicities observed with reactive quinones formed at the microsomal surface by oxidative metabolism may be related to their ability to selectively modify hyperreactive thiols regulating normal functioning of microsomal Ca2+ release channels.

Effects of dextran on tracheal mucociliary velocity in dogs in vivo

We have previously shown that dextran (molecular weight 4kDa) is a potential mucolytic agent, reducing the viscoelasticity and spinnability of cystic fibrosis (CF) sputum and improving its mucociliary clearability during in vitro testing. We wished to see whether low molecular weight (LMW) dextran had similar effects on mucus rheology when administered by aerosol to living dogs, and whether the administration of dextran increased the rate of mucociliary clearance. Healthy mongrel dogs were anesthetized with pentobarbital and intubated. After a 30-min Ringer aerosol delivery during spontaneous breathing, tracheal mucociliary velocity (TMV by charcoal marker particle transport) was measured under bronchoscopic control, and mucus for viscoelasticity analysis (magnetic rheometer) was collected by the endotracheal tube method. Then LMW dextran in Ringer vehicle was delivered by aerosol via the endotracheal tube, followed by the same procedures. We performed eight experiments in eight dogs, involving 30 min administrations of dextran aerosol; all dogs received inhalations of 20 mg/ml, 65 mg/ml, and 200 mg/ml dextran. Compared with Ringer control, TMV increased to 145% of control (P=0.0417) at 65 mg/ml dextran. Mucus viscoelasticity (G*) significantly decreased to 19% of control (P=0.0426) at 65 mg/ml. This in vivo study supports our previous in vitro testing, that LMW dextran decreases the mucus viscoelasticity and increases the rate of mucociliary clearance. We estimate the dosage received by aerosol at 65 mg/ml to be within the effective concentration range studied in vitro, i.e. 10-15 mg/ml final concentration. The results are consistent with the proposed mechanism that the saccharide moieties in LMW dextran compete for hydrogen bonding sites with other mucous glycoproteins. These new hydrogen bonds are structurally and rheologically ineffective, thus reducing the overall cross-link density, and making the mucus more easily cleared by ciliary and cough mechanisms.

[Ultra trace determination of platinum, palladium, gold and rhodium in minerals]

Our work studied the minerals dissolved in aqua regia. The trace Pt(II), Pd(II) Au (III) and Rh(I) complexes were loaded by the mixed carbon powder which carried diphenyl thiourea when aqua regia or hydrochloric acid media as well as stannous chloride were present. We added some carbon powder in ashen loader and determined the elements with atomic emission spectrometry. The determination sensitivity counted with 10 grams of samples is 1 x 10(-9). The RSD for 0.05 x 10(-6) standard Pt, Pd, Au and Rh solutions are 6.0%, 5.1%, 8.5% and 11.4%, respectively. The method is simple and operation is easy. The results satisfy our requirement.

Antagonistic effects of NES and NLS motifs determine S. cerevisiae Rna1p subcellular distribution

Nucleus/cytosol exchange requires a GTPase, Ran. In yeast Rna1p is the GTPase activating protein for Ran (RanGAP) and Prp20p is the Ran GDP/GTP exchange factor (GEF). RanGAP is primarily cytosolic and GEF is nuclear. Their subcellular distributions led to the prediction that Ran-GTP hydrolysis takes place solely in the cytosol and GDP/GTP exchange solely in the nucleus. Current models propose that the Ran-GTP/Ran-GDP gradient across the nuclear membrane determines the direction of exchange. We provide three lines of evidence that Rna1p enters and leaves the nuclear interior. (1) Rna1p possesses leucine-rich nuclear export sequences (NES) that are able to relocate a passenger karyophilic protein to the cytosol; alterations of consensus residues re-establish nuclear location. (2) Rna1p possesses other sequences that function as a novel nuclear localization sequence able to deliver a passenger cytosolic protein to the nucleus. (3) Endogenous Rna1p location is dependent upon Xpo1p/Crm1p, the yeast exportin for leucine-rich NES-containing proteins. The data support the hypothesis that Rna1p exists on both sides of the nuclear membrane, perhaps regulating the Ran-GTP/Ran-GDP gradient, participating in a complete RanGTPase nuclear cycle or serving a novel function.

Borrelia burgdorferi erpT expression in the arthropod vector and murine host

The expression of a Borrelia burgdorferi gene, erpT, was investigated throughout the spirochaete life cycle in the arthropod vector and the murine host. Three phage clones from a B. burgdorferi DNA expression library synthesized a 30 kDa antigen that was recognized by antibodies in the sera of B. burgdorferi-infected mice but not mice hyperimmunized with B. burgdorferi lysates. Differential antibody binding suggested that this protein was preferentially expressed in vivo. This antigen was designated ErpT, based upon 99.6% homology with the BBF01 sequence in the B. burgdorferi genome. ErpT was not detected on spirochaetes cultured in BSK II medium by indirect immunofluorescence or in B. burgdorferi lysates by immunoblotting, implying that ErpT is not readily produced in vitro. erpT mRNA was not discernible by Northern blot but was identified by RNA polymerase chain reaction in vitro, indicating that erpT is expressed at low levels by cultured spirochaetes. erpT expression was then investigated in the vector and mice because B. burgdorferi do not normally reside in culture medium. RNA polymerase chain reaction and immunofluorescence studies demonstrated that erpT was expressed by a small minority of B. burgdorferi (11/500, 2.2%) within unfed ticks and then repressed during engorgement. erpT mRNA or ErpT antibodies were first detected in B. burgdorferi-infected mice at 4 weeks, suggesting that erpT was not expressed in the early stages of murine infection. Then, during persistent infection, RNA polymerase chain reaction showed that erpT was expressed by B. burgdorferi within the joints, heart and spleen, but not by spirochaetes in the skin. Immunization of mice with ErpT was antigenic but was not protective. These studies demonstrate that B. burgdorferi erpT is differentially expressed throughout the B. burgdorferi life cycle, in both the vector and the mammalian host, and is primarily expressed in extracutaneous sites during murine infection.

[An experimental study of anti-angiogenesis with a cartilage-derived inhibitor]

OBJECTIVE

To evaluate the efficacy of a cartilage-derived inhibitor for the treatment of corneal neovascularization in vivo.

METHODS

A cartilage-derived inhibitor (CDI) from bovine scapula was purified to homogeneity. By rabbit corneal neovascularization (CNV) model, the effect of inhibition of CDI under various conditions was determined in corneal micropocket analysis.

RESULTS

The purified CDI could inhibit strongly the growing speed and area of rabbit CNV compared to control (P < 0.001).

CONCLUSION

It is demonstrated that CDI is a potent dose-dependent inhibitor of angiogenesis.