[Stratified endocrine therapy for advanced breast cancer: stratification guided, combination preferred]

The endocrine therapy of hormone receptor (HR)-positive human epidermal growth factor receptor 2 (HER2)-negative breast cancer has stepped into an era of targeted combination therapy. Many targeted agents, led by cyclin-dependent kinase 4/6 inhibitor (CDK4/6i), have provided abundant treatment options for patients with HR-positive HER2-negative advanced breast cancer. To meet the needs of clinical practice in China and standardize the administration of targeted agents, the stratified endocrine strategy for advanced breast cancer has been proposed by Chinese Society of Clinical Oncology (CSCO) Breast Cancer guidelines based on medicine evidence and drug accessibility, offering scientific and organized decision-making guidance for clinical oncologists.

[Evaluation of the impact of the Japanese encephalitis vaccine included in an expanded immunization program on the reported incidence rate of Japanese encephalitis in Gansu province-based on interrupted time series]

Objective: To evaluate the impact of the Japanese encephalitis vaccine included in an expanded immunization program on the reported incidence rate of Japanese encephalitis in Gansu province. Methods: Information on the reported incidence rate of Japanese encephalitis in Gansu province from 1987 to 2019 was collected through the National Population Health Science Data Center and the China Disease Prevention and Control Information System. In addition, the trend of Japanese encephalitis reported incidence rate in Gansu province before and after the inclusion of the Japanese encephalitis vaccine in the expanded immunization program was analyzed using an interrupted time-series design. Results: The annual reported incidence rate of Japanese encephalitis in Gansu province from 1987 to 2019 was 0.448/per 100 000. However, after the inclusion of the Japanese encephalitis vaccine in the expanded immunization program in Gansu province in 2008, the amount of change in the level of Japanese encephalitis reported incidence rate was -2.223/per 100 000 (t=-2.90, P=0.007), the amount of change in the slope of Japanese encephalitis reported incidence rate was 0.082 (t=2.87, P=0.008) with the slope of Japanese encephalitis reported incidence rate as 0.071 (β₁+β₃=0.071). Conclusions: The Japanese encephalitis vaccine has achieved good prevention and control effects in Gansu province in the short term after its inclusion in the expanded immunization program, but outbreaks of Japanese encephalitis have still occurred. Therefore, in the future, Gansu province should promptly adjust the immunization strategy of the Japanese encephalitis vaccine, and strengthen the vaccination of the adult population, especially the rural adult population in the southeastern region of Gansu province, based on the continued focus on the works on Japanese encephalitis vaccination for children and adolescents.

[Orexin-A inhibits γ-aminobutyric acid current of neonatal rat spinal cord ventral horn neurons by activating OX1R, OX2R and Ca2+-independent PKC]

OBJECTIVE

To investigate the effect of orexin-A on the functionality of ionotropic γ-aminobutyric acid (GABA) receptors in spinal cord ventral horn neurons and its mechanisms.

OBJECTIVE

The spinal cord containing the lumbosacral enlargement was isolated from neonatal SD rats (7-12 days old) and sliced. The slices were digested with papain (in 0.18 g/30 mL artificial cerebrospinal fluid) for 40-60 min, and the ventral horn neurons were separated acutely using fire-polished Pasteur pipettes. After the cells adhered to the bottom of Petri dishes, patch-clamp experiments combined with pharmacological methods were performed to test the effects of orexin-A on GABA currents of the neurons treated with SB334867 (a selective OX₁R antagonist), TCSOX229 (a selective OX₂R antagonist), Bis-Ⅳ (a PKC inhibitor), PMA (a PKC agonist), Rp-cAMP (a PKA inhibitor), or BAPTA (Ca²⁺ chelator).

OBJECTIVE

The isolated neurons maintained good morphologies with diverse shapes of cell body and long protrusions. Treatment with orexin-A significantly inhibited the amplitude of GABA-induced current (P < 0.001, n=49) with an inhibition rate of (67.48±12.50)%. SB334867 and TCSOX229, when applied simultaneously, completely abolished the suppressive effect of orexin-A on the GABA currents (P=0.93, n=6), and their separate use partially relieved the suppressive effect of orexin-A (P=0.001, n=8; P=0.02, n=8). The application of Bis-Ⅳ also abolished the suppressive effect of orexin-A on GABA currents (P=0.31, n=5). PMA mimicked the effect of orexin-A in these neurons and significantly inhibited GABA currents with an inhibition rate of (60.79±10.94)%, and the application of orexin-A did not cause further suppression of GABA currents in PMA-treated neurons (P=0.15, n=6). Orexin-A was still capable of suppressing GABA currents in Rp-cAMP-treated neurons (P=0.001, n=5). The extracellular Ca²⁺-free solution (P=0.004, n=8) or the presence of BAPTA (P=0.04, n=7) did not significantly affect the inhibitory effect of orexin-A on GABA currents.

OBJECTIVE

Orexin-A inhibits GABA currents in the ventral horn neurons of rat spinal cord probably by activating OX₁R, OX₂R and Ca²⁺-independent PKC.

STIM1 knock-down decreases the affinity of obinutuzumab for CD20 by altering CD20 localization to Triton-soluble membrane

Obinutuzumab is thought to exert its effects through its high antibody-dependent cellular cytotoxicity (ADCC) via glyco-engineering of the Fc region. In addition, obinutuzumab causes direct binding-induced cell death (DCD) only by specifically binding to its target CD20, a Ca²⁺ channel. However, the specific features of CD20 related to obinutuzumab binding-induction of cell death are not clearly understood. In this study, we evaluated the relationship between the Ca²⁺ channel features of CD20 as a store-operated Ca²⁺ channel (SOC) and obinutuzumab binding-induced cell death. Ca²⁺ channel function and biochemical analysis revealed that CD20 is an Orai1- and stromal interaction molecule (STIM1)-dependent Ca²⁺ pore. However, binding of obinutuzumab on CD20 did not have any effect on Ca²⁺ influx activity of CD20; the direct cell death rate mediated by obinutuzumab binding was almost equivalent with or without the extracellular Ca²⁺ condition. Given the apparent interaction between STIM1 and CD20, we observed Triton-X solubilized obinutuzumab-bound CD20 accompanied by STIM1. Subsequently, obinutuzumab binding and cell death were decreased by STIM1 knock-down in Ramos B cells. Thus, STIM1 directly contributes to cell death by increasing the affinity of cells for obinutuzumab by transferring CD20 to the Triton-soluble membrane region.

[Investigation on social security of pneumoconiosis patients in Chongqing]

Objective: To investigate the living conditions, insurance coverage, and assistance of pneumoconiosis patients diagnosed in Chongqing from May 2006 to May 2018. Methods: A cross-sectional survey was conducted in July 2018, and 40 890 pneumoconiosis patients from occupational diseases report management agency were obtained. 34 625 cases meeting the inclusion criteria were investigated, and descriptive statistical analysis was performed on the data. Results: There were 34 625 cases of pneumoconiosis patients alive in Chongqing, and 22730 (65.6%) had participated in work-related injury insurance, 6 308 (18.2%) had participated in basic medical insurance for urban employees which were still effective. 27 056 (78.1%) had participated in cooperative insurance for urban and rural residents which were still effective. 4 393 (12.7%) received assistance for the residents in need in urban and rural areas. 5827 (16.8%) benefited the policy of "Xiangyu Railway". There were 7 961 cases (2.4%) whose work-related injury insurance had expired did not get one-off compensation, and did not receive any assistance. Conclusion: Most of the patients with pneumoconiosis in Chongqing obtained protection in terms of work-related injury insurance, medical insurance, civil assistance and poverty alleviation to a certain extent, but the strength of the guarantee is not enough. Patients with pneumoconiosis might suffer from poverty caused by illness. It is recommended to improve the system of work-related injury insurance benefits, establish special funds for pneumoconiosis patients, strengthen health education and health promotion for pneumoconiosis patients, and strengthen the management of pneumoconiosis patients.

[Epidemiological analysis of new pneumoconiosis among workers in coal industry in Chongqing]

Objective: To analyze the incidence of pneumoconiosis among workers in the coal industry in the past 13 years in Chongqing, understand the different epidemiological characteristics of new pneumoconiosis among workers in the coal industry in the city, provide basic evidence for the prevention and treatment of pneumoconiosis. Methods: Collecting new cases of pneumoconiosis diagnosed in the coal industry in Chongqing in January 2006-May 2018, and analyze its epidemiological characteristics. Results: In January 2006-May 2018, 25329 cases of pneumoconiosis were added to workers in the coal industry in Chongqing, and 23, 328 cases were present, all male. Among the existing cases: coal workers' pneumoconiosis accounted for 89.30%, silicosis accounted for 10.70%; age distribution was 50-59 years old. The main, accounting for 45.19%, the average age of onset was 52.21±7.45 years; the actual dusting age was mainly 10-19 years, the average actual working age was 17.52±8.47 years; the distribution of the work was mainly by the main coal mining (53.20%) ; There are more new cases in enterprises, accounting for 88.86%; distributed in 36 districts and counties. Conclusion: There was a large number of new pneumoconiosis diseases in the coal industry in Chongqing. Different measures should be taken according to the characteristics of different enterprises, and relevant enterprises should be urged to take the initiative to carry out occupational health surveillance, effectively protect the health of workers, improve the coordination mechanism, improve medical security, and gradually realize government assistance and Social care is combined.

[Study on clinical classification of Japanese encephalitis by Bayes discriminant analysis]

Objective: To construct Bayes discriminant function for clinical classification of common and severe Japanese encephalitis (JE) cases, and to identify cases accurately with quantitative indicators. Methods: Samples of confirmed common and severe JE cases reported by the epidemic surveillance system of Gansu Provincial Center for Disease Control and Prevention from 2005 to 2017 were collected. Non-conditional logistic regression analysis and Bayes stepwise discriminant analysis were used to screen meaningful clinical indicators, so as to construct and evaluate Bayes discriminant function. Results: There were 256 common JE cases and 257 severe JE cases. There were no significant differences in sex, age and occupation distributions between the two groups (P>0.05) and there was significant difference in case fatality rate (P<0.05). Non-conditional logistic regression analysis and Bayes stepwise discriminant analysis, combined with using related literature, to screen 11 clinical indicators for the construction of Bayes discriminant function. Interactive validation showed that the sensitivity of discriminant function was 71.48% (95%CI: 65.53%-76.93%) and the specificity was 73.93% (95%CI: 68.11%-79.19%). The area under ROC curve was 0.761 (95%CI: 0.720-0.803) and the total accuracy rate was 72.71%. Conclusion: Bayes discriminant function can be used to identify common and severe JE cases more accurately, which is helpful for the reasonable treatment and good prognosis of JE patients.

Pathway crosstalk analysis in prostate cancer based on protein-protein network data

Prostate cancer (PCa) is one of the major leading cause in men and no effective biomarkers or therapy have been approved for it to date. This study aimed to explore the molecular mechanisms and identify the potential molecular biomarkers of PCa. The microarray profile GSE38241 including 18 prostate cancer metastasis and 21 normal prostate samples was retrieved from the Gene Expression Omnibus (GEO) database. Differentially expressed genes (DEGs) were identified by Limma. DEGs functions were investigated by Gene Ontology (GO) and pathway enrichment analysis. Moreover, protein-protein interaction (PPI) network of DEGs was constructed, followed by functional analysis of modules. Additionally, pathway crosstalk network was constructed by integrating PPI network and Kyoto encyclopedia of genes and genomes (KEGG) pathways. Totally, 334 up - and 703 down-regulated DEGs were identified. The functions of up-regulated DEGs were significantly enriched in GO terms of cell cycle phase and cell cycle process. While down-regulated DEGs mainly participated in actin filament-based process. Among these pathways in the pathway crosstalk network, T cell receptor signaling pathway, chemokine signaling pathways, endometrial cancer and glioma were found to play critical roles during PC progression. Cell division cycle 45 (CDC45), baculoviral IAP repeat containing 5 (BIRC5) and cell division cycle associated 5 (CDCA5) may be useful markers for predicting tumor metastasis and therapeutic targets for the treatment of PCa patients. Moreover, the pathway crosstalk network provides the groundwork that targeting multiple pathways might be more effective than targeting one pathway alone.

Abstract P4-03-09: Chromosomal instability predicts taxane sensitivity in breast cancer

Taxanes remain among the most effective agents for the treatment of breast cancer. However, ˜50% of patients who receive this therapy do not have a clinical response. Previously, we identified the mechanistic effects of taxane therapy by sampling primary human breast tumors 20 hours after infusion (Sci Trans Med 26:229ra43, 2014). We determined that paclitaxel caused cells to transit mitosis on multipolar spindles, resulting in increased chromosome gains and losses. Preclinical models suggest that tumors have enhanced sensitivity if they have baseline chromosome gains/losses, known as chromosome instability (CIN). The aim of this study was to compare CIN against other predictive biomarkers in a retrospective cohort of advanced breast cancer patients who receive single-agent taxane therapy.

Methods: We identified 36 subjects with metastatic breast cancer and measurable disease who received taxane therapy and had available archived tissue. Responses were determined by RECIST 1.1 criteria. We evaluated chromosome number on a cell-by-cell basis using 6 centromeric FISH probes. Additionally we measured rates of proliferation by phospho-histone H3 (p-HH3) and Ki67, previously reported biomarkers, β-tubulin III, P-gp1 and MAD1 by quantitative immunofluorescence. CIN was estimated as the fraction of cells with non-modal chromosome numbers across chromosomes 3, 4, 7, 9, 10, and 17.

Results: Of the 36 subjects, 19 had ER/PR+HER2- disease (53%), 9 had HER2-positive disease (25%), and 8 TNBC (22%). Single-agent chemotherapy was used for all including paclitaxel in 16, nab-paclitaxel in 17, and docetaxel in 3 (HER2+ patients received concurrent trastuzumab). RECIST responses ranged from disease progression (8%, n=3), stable disease (50%, n=18), and partial response (42%, n=15). No complete responses were observed. Time on therapy ranged from 1.4 months to 28 months. No statistically significant correlations were found between tumor type or prior chemotherapy and response to taxanes. Archived metastatic samples were available for 21 subjects. Analysis showed large variations in Ki67, pHH3, β-tubulin III, P-gp1, MAD1, and CIN amongst samples. The strongest correlation was found between tumor response and high levels of CIN, with a Spearman's correlation coefficient of 0.38 (p=0.04). Surprisingly, there was an inverse correlation between Ki67 and taxane response, although this did not reach statistical significance.

Biomarkers correlated with response to taxaneN=21Ki67 (%)pHH3 (H)βtub3 (H)P-gp1 (H)MAD1 (H)CIN (%)min0.850.000.673.002.8324.2max45.14.8915129923165.8Spearman rho-0.3650.242-0.1650.232-0.08960.382p (1-tailed)0.05190.1400.2370.1550.3500.0425H = H-score; CIN is estimated as % of cells with non-modal chromosomes

Conclusions: Chromosomal instability is a promising biomarker for predicting sensitivity to taxane therapies. Additional studies will be necessary to validate CIN as a biomarker and to determine whether 6-chromosome FISH can be supplanted by low-pass single-cell DNA sequencing.

Citation Format: Esbona K, Jin N, Correia-Staudt KL, Lager AM, Heidke T, Laffin J, Weaver BA, Burkard ME. Chromosomal instability predicts taxane sensitivity in breast cancer [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P4-03-09.

[Clinical characteristics of 128 hospitalized patients with syndrome of inappropriate antidiuretics of different etiologies]

Objective: To summarize and analyze the clinical features and etiologies in hospitalized patients with syndrome of inappropriate antidiuretics (SIAD) during the past 25 years. Methods: All data of 128 patients with SIAD admitted to Chinese PLA General Hospital since January 1991 to January 2016 were collected. SIAD was diagnosed based on the 1957 criterion. Results: (1) The most frequent causes of increased inappropriate secretion of vasopressin were malignant tumors, lung diseases (e. g. pneumonia), and central nervous system diseases, in which malignant tumors accounted for 38.28% of the SIAD. (2) During the past 25 years, the proportion of malignant diseases declined from 4/7 to 35.29%, while, the proportion of pulmonary infection increased from 1/7 to 35.29% (P<0.05). (3) The patients with malignant tumors had the lowest serum sodium and serum osmolality among all SIAD patients. (4) CT scan had a high diagnostic value for chest and brain detection. (5) Among three SIAD subjects with unknown reasons at onset, two were diagnosed with small cell lung cancer and one with gastric cancer during follow-up. Conclusion: The etiology of SIAD is complex and it could be attributed to multifarious etiological factors. Malignant tumors account for the largest proportion of all patients, and pulmonary infection was ranked in second place. Cautions on tumors have to be taken when serum sodium of a SIAD patient is below 118.1 mmol/L.

[An analysis of four cases of misdiagnosed primary lymphocytic hypophysitis]

To improve the differential diagnosis of sellar region mass, 4 cases with sellar mass and misdiagnosed as lymphocytic hypophysitis (LYH) were reviewed retrospectively.The 4 patients (2 male and 2 female) aged 20-60 years old were all presented with symptoms of headache, polydipsia and polyuria.Biochemical studies confirmed the diagnoses of central diabetes insipidus and hypopituitarism.Head MRI scans showed LYH like image for all the cases, and, thus, high dose methylprednisolone pulse therapy (HDMPT) was applied to the patients.Their symptoms deteriorated and the sellar mass enlarged after a short period of partial improvement.Operations were performed in all the patients.Histology study showed craniopharyngioma with abscess, primary abscess, secondary hypophysitis caused by Wegener's granulomatosis, and germinoma with secondary hypophysitis, respectively.In conclusion, surgery or biopsy is necessary for those who presented with sellar region mass and was suspected to be with LYH, but with poor response or even worse after HDMPT.

Phosphoglycerate mutase 1 promotes cancer cell migration independent of its metabolic activity

Phosphoglycerate mutase 1 (PGAM1) is a glycolytic enzyme that coordinates glycolysis and biosynthesis to promote cancer growth via its metabolic activity. Here, we report the discovery of a non-metabolic function of PGAM1 in promoting cancer metastasis. A proteomic study identified α-smooth muscle actin (ACTA2) as a PGAM1-associated protein. PGAM1 modulated actin filaments assembly, cell motility and cancer cell migration via directly interacting with ACTA2, which was independent of its metabolic activity. The enzymatically inactive H186R mutant retained its association with ACTA2, whereas 201-210 amino acids deleted PGAM1 mutant lost the interaction with ACTA2 regardless of intact metabolic activity. Importantly, PGAM1 knockdown decreased metastatic potential of breast cancer cells in vivo and PGAM1 and ACTA2 were jointly associated with the prognosis of breast cancer patients. Together, this study provided the first evidence revealing a non-metabolic function of PGAM1 in promoting cell migration, and gained new insights into the role of PGAM1 in cancer progression.

[An evaluation of plasma aldosterone-to-active-renin ratio in different postures in combination with aldosterone concentration in the diagnosis of aldosteronoma]

OBJECTIVE

To investigate the diagnostic value of plasma aldosterone-to-active-renin ratio(ARR)in combination with plasma aldosterone concentration(PAC)in the predication of aldosteronoma(APA).

METHODS

A total of 85 APA and 155 essential hypertension(EH)patients from January 2012 to December 2014 in Chinese PLA General Hospital were enrolled. The ROC curve was applied to calculate the optimal cut-off points of ARR for APA.

RESULTS

(1)The optimal cut-off point of supine ARR was 1 707.4(pmol/L)/(μg·L(-1)·h(-1))[61.64(ng/dl)/(μg·L(-1)·h(-1))] with the sensitivity, specificity and accuracy of 89.41%, 80.65% and 83.75%, respectively. The specificity and accuracy of the diagnostic value for APA increased (89.03% and 87.5% respectively) when supine ARR cut-off point were used in combination with supine PAC over 329.4 pmol/L. (2) The optimal cut-off point of upright ARR was 741.5 (pmol/L)/(μg·L(-1)·h(-1))[26.77(ng/dl)/(μg·L(-1)·h(-1) )]with the sensitivity, specificity and accuracy of 85.88%, 91.61% and 89.58%, respectively. Similarly, the specificity and accuracy greatly improved (94.84% and 91.67%, respectively) when upright ARR were applied together with upright PAC over 323.1 pmol/L.

CONCLUSIONS

Both spine and upright ARR can be used in screening for APA. Moreover, the specificity and accuracy could be improved when ARR and PAC were used together both in the supine and upright position.

Mesenchymal stromal cells inhibit proliferation of virus-specific CD8(+) T cells

Mesenchymal stromal cells (MSCs) possess broad immunomodulatory capacities that are currently investigated for potential clinical application in treating autoimmune disorders. Third-party MSCs suppress alloantigen-induced proliferation of peripheral blood mononuclear cells providing the rationale for clinical use in graft-versus-host disease (GvHD). We confirmed that MSCs strongly inhibited proliferation of CD8(+) T cells in a mixed lymphocyte reaction. However, MSCs also suppressed proliferation of T cells specifically recognizing cytomegalovirus (CMV) and influenza virus. Inhibition was dose dependent, but independent of the culture medium. MSCs inhibited proliferation of specific CD8(+) T cells and the release of IFN-γ by specific CD8(+) T cells for immunodominant HLA-A2- and HLA-B7- restricted antigen epitopes derived from CMV phosphoprotein 65 and influenza matrix protein. This is in contrast to a recently reported scenario where MSCs exert differential effects on alloantigen and virus-specific T cells potentially having an impact on surveillance and prophylaxis of patients treated by MSCs.

Serum cystatin C is associated with renal function recovery in critically ill patients undergoing continuous renal replacement therapy

PURPOSE

Serum cystatin C (sCyC) has long been known as a reliable biomarker of renal injury. However, it remains to be tested whether sCyC is a reliable biomarker to predict renal recovery after continuous renal replacement therapy (CRRT).

METHODS

A retrospective analysis of patients admitted to a tertiary 18-bed intensive care unit from January 2008 to December 2011 was performed. Univariate and multivariate regression analyses were performed to test the independent predictors of renal recovery. The diagnostic value of sCyC in predicting renal recovery was assessed using a receiver operating characteristic curve (ROC).

RESULTS

Older age and higher sCyC were independent risk factors of renal nonrecovery (OR: 1.40 and 4.76, respectively). The area under the ROC of sCyC to predict renal recovery was 0.87 (95% CI: 0.82-0.92), with a sensitivity and specificity of 80.5% and 83.5% at the cutoff of 2.98 mg/l.

CONCLUSION

A high sCyC level at the initiation of CRRT is associated with poor renal outcome.

Immune responses of mice to prime-boost vaccination with the recombinant DNA and Fowlpox virus both expressing HIV-2 Gag-gp105

Human immunodeficiency viruses 1 and 2 (HIV-1, 2) present a public health problem for which there is neither an effective antiviral therapy nor a preventive vaccine. In this study, the immune responses of mice to prime-boost vaccination with the recombinant DNA (rDNA) and recombinant Fowlpox virus (rFPV) both expressing HIV-2 Gag-gp105 chimeric protein, were compared to those elicited by each vector alone. Mice primed with the rDNA and boosted with the rFPV showed HIV-2-specific antibody levels, splenic CD4+ and CD8+ T-lymphocyte numbers, and Gag-gp105-specific cytotoxic T-lymphocytes (CTL) activity increased by 20-30% as compared with those elicited by these vaccines alone. These findings suggested that the prime-boost strategy combining rDNA and rFPV elicited significant Gag-gp105 - specific cellular and humoral immune responses, thus supporting this novel approach to the immunization against HIV infections.

Complete atrioventricular block associated with dapsone therapy: a rare complication of dapsone-induced hypersensitivity syndrome

Dapsone is still widely used for a range of infectious and inflammatory diseases. A potential severe side-effect, known as dapsone-induced hypersensitivity syndrome (DHS), may occur. DHS is characterized by fever, skin rashes, lymphadenopathy and multiorgan dysfunction manifesting as hepatitis, cholangitis, pneumonitis, colitis, thyroiditis and myocarditis. However, DHS-associated complete atrioventricular block has not previously been reported. We describe here a 45-year-old Chinese woman who developed DHS after 5 weeks of dapsone therapy for pustular palmoplantar psoriasis. In addition to typical DHS symptoms, she experienced several episodes of syncope as a result of complete atrioventricular block which was successfully reversed with a permanent pacemaker implantation.

Extraordinary electroconductance in metal-semiconductor hybrid structures

We report the phenomenon of extraordinary electroconductance in microscopic metal-semiconductor hybrid structures fabricated from GaAs epitaxial layer and a Ti thin film shunt. Four-lead Van der Pauw structures show a gain of 5.2% in electroconductance under +2.5 kVcm with zero shunt bias. The increase in the sample conductance results from the thermionic field emission of electrons and the geometrical amplification. A model provides good agreement with the experimental data and clearly demonstrates the geometry dependence of the field effect in extraordinary electroconductance (EEC). The differences between EEC devices and field effect transistors, such as junction field effect transistor (FET) and Schottky barrier gate FET, are discussed.

Screening for extended-spectrum beta-lactamase-producing Enterobacteriaceae among high-risk patients and rates of subsequent bacteremia

BACKGROUND

Bloodstream infections due to extended-spectrum beta-lactamase (ESBL)-producing Enterobacteriaceae have been associated with increased hospital costs, length of stay, and patient mortality. However, the role of routine inpatient surveillance for ESBL colonization in predicting related infection is unclear.

METHODS

From 2000 through 2005, we screened 17,872 patients hospitalized in designated high-risk units for rectal colonization with vancomycin-resistant enterococci and ESBL-producing Enterobacteriaceae using a selective culture medium. In patients with a bloodstream infection due to ESBL-producing Enterobacteriaceae (ESBL-BI) during the study period, surveillance results were evaluated for evidence of antecedent ESBL-producing Enterobacteriaceae colonization.

RESULTS

The rate of ESBL-producing Enterobacteriaceae colonization doubled during the 6-year study period, increasing from 1.33% of high-risk patients in 2000 to 3.21% in 2005. Among patients with ESBL-producing Enterobacteriaceae colonization, 49.6% also carried vancomycin-resistant enterococci. The number of ESBL-BIs increased >4-fold in 5 years, from 9 cases in 2001 to 40 cases in 2005. Of 413 patients colonized with ESBL-producing Enterobacteriaceae, 35 (8.5%) developed a subsequent ESBL-BI. Of concern, more than one-half of all ESBL-BIs occurred in patients who were not screened. These 56 patients received a diagnosis of ESBL-BI in the emergency department, when hospitalized in low-risk medical units, or at transfer from an acute or long-term health care facility.

CONCLUSIONS

Colonization with ESBL-producing Enterobacteriaceae is increasing at a rapid rate, and routine rectal surveillance for ESBL-producing Enterobacteriaceae may have clinical implications. However, in our experience, over one-half of patients with an ESBL-BI did not undergo screening through our current surveillance measures. As a result, targeted screening for ESBL-producing Enterobacteriaceae among additional patient populations may be integral to future ESBL-BI prevention and management efforts.

Microtubule disruption modulates the Rho-kinase pathway in vascular smooth muscle

Microtubules constitute one of the main cytoskeletal components in eukaryotic cells. Recent studies have shown that microtubule disruption induced significant vasoconstriction or enhanced agonist-induced contraction in vascular smooth muscle. However, the underlying mechanisms are not clear. We hypothesize that microtubule disruption may affect contractile signaling in vascular smooth muscle and lead to the enhanced contraction. The present study demonstrates that both colchicine and nocodazole induced a small but sustained contraction (4-6% P0) in rat aortic rings. This microtubule disruption-induced contraction was abolished by co-treatment with either HA 1077 or Y-27632, both of which are relatively specific Rho-kinase inhibitors. However, co-treatment with ML-9, an inhibitor of myosin light chain kinase, (MLCK) did not have a significant effect on the colchicine-induced contraction. The enhanced KCl-induced contraction due to treatment with colchicine was also blocked by inhibition of Rho-kinase, but not by inhibition of MLCK. These results indicate that microtubule disruption modulates contractile signaling in vascular smooth muscle, mainly through the Rho-kinase pathway, but not MLCK. Interestingly, the colchicine-enhanced, phenylephrine-induced contraction was not completely blocked by inhibition of Rho-kinase suggesting that other signaling pathways might also be involved.

Rho-kinase activation is involved in hypoxia-induced pulmonary vasoconstriction

Rho-associated serine/threonine kinase (Rho-kinase) is a downstream effector of small GTPase RhoA that has recently been shown to play an important role in regulating smooth muscle contraction. The present study investigated the role of Rho/ Rho-kinase in hypoxia-induced pulmonary vasoconstriction (HPV). Small pulmonary resistance vessels and cultured pulmonary arterial smooth muscle cells (PASMCs) from the rat were used. PASMCs exposed to hypoxia (PO(2) = 26 +/- 2 mm Hg) showed a significant increase in Rho-kinase activity. Exposure to hypoxia for 20, 40, 60, 90, and 120 min also resulted in a significant increase in myosin light chain (MLC) phosphorylation at all time points in PASMCs. Hypoxia-induced MLC phosphorylation was inhibited by Y-27632 (a Rho-kinase inhibitor), exoenzyme C3 (a specific Rho inhibitor), or toxin B (an inhibitor for Rho proteins). In addition, hypoxia-induced Rho-kinase activation was blocked by C3 and toxin B. Small rat intrapulmonary arterial rings, which were made hypoxic (PO(2) = 30 +/- 3 mm Hg), showed a slow sustained contraction, and Y-27632 caused a significant relaxation during the sustained phase of HPV in a concentration-dependent manner. In summary, the data show that Rho-kinase is activated by hypoxia in PASMCs, and Rho/Rho-kinase is functionally linked to hypoxia-induced MLC phosphorylation and plays a role in the sustained phase of HPV.

Hypoxia activates jun-N-terminal kinase, extracellular signal-regulated protein kinase, and p38 kinase in pulmonary arteries

Chronic alveolar hypoxia is the major cause of pulmonary hypertension. The cellular mechanisms involved in hypoxia- induced pulmonary arterial remodeling are still poorly understood. Mitogen-activated protein kinase (MAPK) is a key enzyme in the signaling pathway leading to cellular growth and proliferation. The purpose of this investigation was to determine the roles that MAPKs, specifically Jun-N-terminal kinase (JNK), extracellular signal-regulated protein kinase (ERK), and p38 kinase, play in the hypoxia-induced pulmonary arterial remodeling. Rats were exposed to normobaric hypoxia (10% O(2)) for 1, 3, 7, or 14 d. Hypoxia caused significant remodeling in the pulmonary artery characterized by thickening of pulmonary arterial wall and increases in tissue mass and total RNA. JNK, ERK, and p38 kinase tyrosine phosphorylations and their activities were significantly increased by hypoxia. JNK activation peaked at Day 1 and ERK/p38 kinase activation peaked after 7 d of hypoxia. The results from immunohistochemistry show that hypoxia increased phospho-MAPK staining in both large and small intrapulmonary arteries. Hypoxia also upregulated vascular endothelial growth factor messenger RNA (mRNA) and platelet-derived growth factor receptor mRNA levels in pulmonary artery with a time course correlated to the activation of ERK and p38 kinase. The gene expressions of c-jun, c-fos, and egr-1, known as downstream effectors of MAPK, were also investigated. Hypoxia upregulated egr-1 mRNA but downregulated c-jun and c-fos mRNAs. These data suggest that hypoxia-induced activation of JNK is an early response to hypoxic stress and that activation of ERK and p38 kinase appears to be associated with hypoxia-induced pulmonary arterial remodeling.

H(2)O(2)-induced egr-1, fra-1, and c-jun gene expression is mediated by tyrosine kinase in aortic smooth muscle cells

Hydrogen peroxide (H(2)O(2)) has recently been shown to have a dual effect on cell growth by stimulating proliferation and triggering apoptosis. Apoptosis induced by H(2)O(2) is a direct consequence of oxidant injury, while the proliferative response to H(2)O(2) is thought to be a protective mechanism against oxidant injury. Signaling of the H(2)O(2)-induced proliferative effect has been proposed to occur via the activation of mitogen-activated protein kinase (MAPK) and increase in expression of transcription factors. In the present study, H(2)O(2)-induced mitogenic signaling in aortic smooth muscle cells (ASMC) was investigated with a specific focus on the roles of tyrosine kinase and tyrosine phosphatase in the regulation of the H(2)O(2)-stimulated egr-1, fra-1, and c-jun transcription. The results show that H(2)O(2)-induced increases in egr-1, fra-1, and c-jun mRNA levels, as measured by Northern blot analysis, are time and dose dependent with the peak of the response within 2 h. Tyrosine kinase inhibitors (genistein, amino-genistein, and tyrphostin 51) significantly attenuated H(2)O(2)-induced expression of these genes and a tyrosine phosphatase inhibitor (perox-vanadate) stimulated their expression. H(2)O(2) stimulated tyrosine kinase activities and caused protein tyrosine phosphorylation, which was blocked by tyrphostin 51. H(2)O(2) also caused tyrosine phosphorylation of platelet derived growth factor (PDGF) receptor. These data show that H(2)O(2) increases egr-1, fra-1, and c-jun mRNA levels in vascular smooth muscle cells, and the increase in expression of these genes is mediated by activation of tyrosine kinase. Our data also provide evidence that the H(2)O(2)-induced mitogenic response is, in part, mediated through the receptor tyrosine kinase, PDGF receptor.

Effects of prostaglandins on form deprivation myopia in the chick

PURPOSE

To investigate the possible role of endogenous prostaglandins in the development of form deprivation myopia, as well as the effects of exogenous prostaglandins using atropine as a positive control.

METHODS

Monocular form deprivation was accomplished by mounting a translucent occluder on one eye of 2-3 day old chicks for 1-4 weeks. Ocular occlusion for 1-2 weeks was used for pharmacological blocking experiments. The axial length of the eye was measured by ultrasonography.

RESULTS

Indomethacin, administered intramuscularly, subconjunctivally or intravitreally had no significant effect on myopia development. Exogenous PGE2, PGF2alpha and latanoprost acid administered subconjunctivally, or topically as isopropyl ester eyedrops had no statistically significant effect on the myopia development. However, PGF2alpha significantly (p<0.01) attenuated the development of myopia after intravitreal injection. The other two prostaglandins had no statistically significant effect.

CONCLUSIONS

Endogenous prostaglandins are unlikely to play a significant role in the development of form deprivation myopia in the chick. However, PGF2alpha suprisingly seems to retard the development of form deprivation myopia, but only when administered intravitreally. Whether the mechanism of the myopia retardation is direct or indirect remains unknown.

Regional blood flow in the myopic chick eye during and after form deprivation: a study with radioactively-labelled microspheres

The purpose of the present study was to determine the regional blood flow in the myopic chick eye during and after short-term monocular form deprivation. Chicks were monocularly form-deprived by covering one eye with a translucent occluder for 7-10 days. The anterior chamber-lens distance, the vitreous chamber length and the axial length of the eye were measured by ultrasonography, the equatorial diameter was measured with calipers and the size of the eye was estimated by weighing. The regional blood flow in the eye was determined with radioactively-labelled microspheres in three groups of animals: a group of chicks wearing an occluder (n = 10), a group of chicks in which the occluder was removed 7 or 24 hr prior to the blood flow determination (n = 9), and a group of age-matched control chicks without occluder (n = 9). Monocular form deprivation increased the axial length 0.64 +/- 0.06 and 0.56 +/- 0.09 mm compared to the contralateral control eye in the two groups of chicks wearing an occluder (P < 0.001). Both the equatorial diameter and the weight of the eye increased significantly (P < 0.001). Removal of the occluder tended to reduce the difference in the vitreous chamber length during the first 24 hr. There was no statistically significant difference in the blood flow of the anterior uvea, choroid, pecten or the sclera between the form-deprived and contralateral control eyes (P > 0.05, n = 10), but when comparing to the control group, the blood flow was significantly (P < 0.05) reduced in the choroid of the occluded eye. A similar tendency was found in the anterior uvea. When the blood flow was measured 7-24 hr after the removal of the occluder, a marked increase was found in the blood flow of the choroid of both eyes compared to the situation during occlusion (P < 0.001), and to the control group (P < 0.05). In the pecten a significant (P < 0.05) increase of the blood flow in comparison to the situation during occlusion and the control group was detected after removal of the occluder, and a similar change was found in the contralateral control eye, but it did not reach statistical significance. In the anterior uvea and sclera the blood flow was also significantly (P < 0.05) or almost significantly increased after removal of the occluder in both eyes. The arterial blood pressure was 79 +/- 2, 88 +/- 2 and 99 +/- 5 mmHg in the control group, the group with monocular occlusion, and the group in which the occluder was removed, respectively.Thus, monocular form deprivation in the chick reduced the choroidal blood flow, and a similar tendency was found in the anterior uvea. However, there was no statistically significant difference in blood flow between the form-deprived and contralateral control eyes. Removal of the occluder increased the blood flow in all tissues, notably the choroid and pecten. Generally the changes in blood flow seemed to be bilateral, despite monocular occlusion.

Influence of microtubules on vascular smooth muscle contraction

Microtubules are ubiquitous in eukaryotic cells and play key roles in many cellular activities. The purpose of this study was to investigate the influence of microtubules on vascular smooth muscle contraction. Quantitative immunocytochemical analysis of rat aortic tissue revealed that, relative to the control group, colchicine (15 muM, 90 min) and nocodazole (15 muM, 90 min) decreased the microtubule density by 40-50% while taxol (10 muM, 90 min) increased the microtubule density by 33%. Isometric contraction studies demonstrated that both colchicine and nocodazole caused an upward shift in the phenylephrine (10(-8) to 10(-5) M) dose-response curve while taxol caused no significant change when compared to the control group. Potassium chloride (30 mM) induced 55 +/- 5% P0 contraction in DMSO treated vessel rings. The active tension increased to 73 +/- 5% P0 and 71 +/- 6% P0 after pretreatment of the aortic rings with colchicine or nocodazole, respectively. Taxol did not cause a significant change in the active tension (56 +/- 7% P0). These results indicate that microtubule depolymerization enhances isometric contraction of vascular smooth muscle and this enhanced contraction is not receptor dependent. Pretreatment of the aortic rings with an inhibitor of nitric oxide synthase (NOS) (Nomega-nitro-L-arginine) did not change the increased contractile response to phenylephrine due to microtubule depolymerization suggesting that this phenomenon is not mediated by endothelium dependent relaxation.

Retroviral immunotoxin gene therapy of acute myelogenous leukemia in mice using cytotoxic T cells transduced with an interleukin 4/diphtheria toxin gene

The potential benefit of immunotoxin (IT) for cancer therapy has mostly been limited by the fact that only a small portion of injected dose ever reaches the cancer target. Thus, we set out to determine whether antigen-specific CTLs would be suitable vehicles to deliver IT to the site of cancer cells in vivo. A retroviral vector was constructed for gene therapy with (interleukin 4) IL-4 positioned downstream of its 20-amino-acid leader sequence that permitted cotranslational protein synthesis of IT along with truncated diphtheria toxin (DT). IL-4 was chosen as a ligand based on the expression of IL-4 receptor (IL-4R) on most acute myeloid leukemia cases. The first-time expression and secretion of a cytokine/DT fusion toxin was accomplished in mammalian NIH.3T3 cells, and then a retroviral vector was assembled. The retroviral IT was used to transiently transduce T15, a CD8+ CTL T cell line that specifically recognized C1498 (a lethal murine acute myeloid leukemia cell line). Transduced T15 T cells expressed intracellular DT and IL-4 as determined by immunofluorescence. Secreted IT supernatants collected from T15 had enzymatic activity and killed IL-4R+ C1498 cells, but not IL-4R- EL4 cells. Intravenous injection of transduced T15, but not nontransduced T15, into mice with s.c. tumors significantly inhibited tumor growth. In contrast, systemic therapy with a bacterial preparation of the same IL-4 IT given at its maximum tolerated dose did not protect. Retroviral IT-treated mice showed no sign of the renal or hepatic toxicity that is common to this class of IT. Together, these data indicate that retroviral IT may solve problems relating to systemic IT therapy by delivering reagent more directly to the site of cancer in vivo and may impart new anticancer defense mechanisms to antigen-specific T cells.

Immunolabeling of the major cell surface protein antigen of Streptococcus sobrinus with monoclonal antibody

OBJECTIVE

The purpose of this study was to determine the accessibility of monoclonal antibody (McAb), specific for the major cell surface protein antigen (PAg) of Streptococcus sobrinus, to the surface of its native epitopes.

MATERIALS AND METHODS

An indirect immunogold labeling technique was used to detect the reaction of McAb with S. sobrinus 6715. The reactions of polyclonal antibodies (PcAbs) against S. sobrinus 6715 or PAg with S. sobrinus 6715, S. mutans Ingbritt C and S. rattus BHT were studied as controls.

RESULTS

The results indicated that PAg was localized on the outer cell surface of S. sobrinus, and McAb was reactive with only a few epitopes of the cell surface, whereas PcAbs were found to be reactive with more epitopes.

CONCLUSIONS

McAb was specific for the PAg, but there was cross-reaction with S. mutans. Also there seemed to be an association between the fuzzy coat on the surface of S. sobrinus and PAg.

The height regulation of a near-field scanning optical microscope probe tip

A nonoptical detection of the optical fibre tip has been developed. By detecting the output signal from a tiny piezoelectric detector attached to the vibrating fibre tip, the distance between the fibre tip and the sample has been successfully controlled. The frequency responses of the system composed of tip, the dither and the detector have been studied. The difference between the shear-force detection and the tapping-mode detection is discussed. It is found that the shear force exerted on the tip reduces the vibration amplitude with an unvaried resonance frequency. However, in the tapping mode, the resonance frequency varies with the tip-sample distance as the force is exerted on the fibre tip only within a half period. This requires better adjustments for the tapping-mode detection.

Hydrogen peroxide stimulates extracellular signal-regulated protein kinases in pulmonary arterial smooth muscle cells

Hydrogen peroxide (H2O2) has emerged as an important intracellular signaling molecule and has been shown to stimulate the growth of vascular smooth muscle cells. Activation of p44 and p42 extracellular signal-regulated protein kinases (ERK1 and ERK2) is an important step in the cascade leading to cell growth and proliferation. In the present study, we investigated the effects and mechanisms of H2O2 on activation of ERK1 and ERK2 in pulmonary arterial smooth muscle cells (PASMC). Assays of immune-complex kinase activity revealed that exposure of PASMC to H2O2 stimulated myelin basic protein (MBP) phosphorylation in a concentration- and time-dependent manner. Western blot analysis done with phospho-specific mitogen-activated protein (MAP) kinase antibodies demonstrated that H2O2 stimulated the phosphorylation of p42, p44, p46, and p38 MAP kinases. H2O2 also increased the expression of the early immediate genes c-jun and fra-1. Activation of ERK1 and ERK2 by H2O2 was significantly reduced by downregulation of protein kinase C (PKC) with phorbol-12-myristate-13-acetate (PMA) or by a PKC inhibitor, calphostin C. In addition, removal of extracellular Ca2+, depletion of the intracellular Ca2+ pool by thapsigargin, or pretreatment of PASMC with the calmodulin antagonist N-(6 aminohexyl)-5-chloro-1-naphthalenesulfonamide (W-7) or with calmidazolium chloride also decreased H2O2-induced ERK1 and ERK2 activation. Furthermore, stimulation of ERK1 and ERK2 activity by H2O2 was partly attenuated by genistein, a tyrosine kinase inhibitor. Taken together, these data suggest that H2O2 activates ERK1, ERK2, p46 JNK, and p38 MAP kinases in PASMC. The activation of ERK1 and ERK2 appears to be primarily dependent on PKC, and to be partly modulated by Ca2+/calmodulin and by activation of tyrosine kinases.

Upstream genomic sequence of the human connexin26 gene

Human connexin 26 (Cx26) has been considered to be a candidate suppressor gene in mammary epithelial cells. To gain insight into the transcriptional regulation of this gene, we have cloned and sequenced the 5' portion of the gene, which extends 4.8 kb upstream from the ATG translation start site. The 3' end of the non-coding exon 1 (160 bp) is located at 3149 bp upstream from the 5' end of exon 2. Comparison between the human Cx26 gene and the mouse gene reveals a highly conserved promoter region with 81% homology. In addition to six GC boxes and two GT boxes, a TTAAAA box is located at -24 to -19 bp upstream of the transcription start point. Analogous to the mouse beta-casein gene, the promoter region of the human Cx26 gene also contains a YY1-like binding site and a consensus mammary gland factor binding site.