Moment switching in nanotube magnetic force probes

Magnetic images of high density vertically recorded media using metal-coated carbon nanotube tips exhibit a doubling of the spatial frequency under some conditions (Deng et al 2004 Appl. Phys. Lett. 85 6263). Here we demonstrate that this spatial frequency doubling is due to the switching of the moment direction of the nanotube tip. This results in a signal which is proportional to the absolute value of the signal normally observed in MFM. Our modeling indicates that a significant fraction of the tip volume is involved in the observed switching, and that it should be possible to image high bit densities with nanotube magnetic force sensors.

Neutralizing IL-7 promotes long-term allograft survival induced by CD40/CD40L costimulatory blockade

Memory T cells are somewhat resistant to immunosuppresion. They therefore pose a threat to inducing long-term allograft survival. IL-7 is essential for memory T-cell generation. Here, we investigated whether neutralizing IL-7 promotes allograft survival. We found that neutralizing IL-7 alone did not significantly prolong allograft survival. However, blocking both IL-7 and CD154 signaling synergistically prolonged allograft survival. In contrast, neutralizing IL-2 failed to further prolong allograft survival induced by CD40/CD154 costimulatory blockade. Allospecific memory CD8+ T-cell generation was severely impaired under the treatment of anti-IL-7 plus anti-CD154 Ab while administering recombinant IL-7 enhanced CD8+ memory generation even under donor-specific transfusion plus anti-CD154 Ab treatment. Neutralizing IL-7, but not IL-2, together with blocking CD154 synergistically suppressed the proliferation of naïve/effector CD8+ T cells infiltrating grafts. Nevertheless, neutralizing IL-7 did not alter regulatory T-cell generation while neutralizing IL-2 suppressed their generation. Hence, targeting IL-7 represents a new strategy to prolong allograft survival by acting on both naïve and memory T cells. Long-term allograft survival may be achieved by neutralizing IL-7 plus CD40/CD154 blockade, since CD40/CD154 costimulatory blockade prevents acute rejection while neutralizing IL-7 suppresses the generation of memory T cells that persist and mediate late or chronic rejection.

Circulating levels of the breast cancer growth factor GP88 in the serum of breast cancer (BC) patients

20050

Background: The 88 kDa autocrine growth factor PC-Cell Derived Growth Factor (GP88) plays a critical role in breast tumorigenesis. GP88 expression was low in estrogen receptor positive cells, whereas in ER negative cells, it was constitutively overexpressed. Increased GP88 expression was associated with anti-estrogen therapy resistance in ER+ cells and Herceptin resistance in Her-2 overexpressing breast tumors. Antisense inhibition of GP88 expression in human breast adenocarcinoma lead to inhibition of tumor growth in vivo. Immunohistochemical studies have shown that GP88 was expressed in 80% of invasive ductal carcinomas in correlation with expression of poor prognosis markers whereas normal tissues and benign breast lesions were negative. Since GP88 is secreted by breast cancer cells, we examined whether GP88 was found in the circulation at an elevated level in the sera of breast cancer patients when compared to healthy individuals. Methods: A blood sampling study was conducted to determine the serum level of GP88 in healthy volunteers (HV) and breast cancer patients (BC pts). Ten ml of blood was drawn every three months to obtain serum. GP88 serum concentration was determined in triplicate by quantitative enzyme immunoassay using human GP88 as standard. 126 BC pts were accrued. . In addition, sera from 53 healthy volunteers were obtained to establish a GP88 baseline in HV. BC pts characteristics: race: Caucasian- 61, African American-60, Asian-5; median age: 52.5 (range 26–84), stage I-32, II-34, III-18, IV-42. Results: Circulating GP88 was measurable in the serum. Median level of GP88 was 32.8 ng/ml (range 15.3–42.8) in HV and 43.8 ng/ml (range 15.4–158.4) in BC pts, (p-value = 0.0007). Conclusions: GP88 is measurable in the sera of HV and BC pts. Comparison between the two groups indicates that GP88 level is significantly higher in the sera of BC pts. These studies are important since it identifies GP88 as a measurable biomarker that is also a therapeutic target of malignant transformation or malignant progression of breast carcinoma (BC). Future studies will examine the correlation of GP88 level with BC prognostic factors. Correlation between the serum level of GP88 and therapeutic response to systemic therapy in breast cancer patients will also be assessed.

[Table: see text]

An RT-PCR-based multi-gene prognostic signature predicts distant metastasis of node negative, ER positive breast cancer from FFPE sections

506

Background: Gene expression profiles have been shown to predict distant metastasis risk in breast cancer patients. For routine medical practice, molecular prognostic tests need to be able to quantify metastasis risk with readily available samples and optimally employ regulatory-approved platforms. Methods: 142 early stage, N-, ER+, untreated breast cancer patients were chosen. Mean age was 61.8 (31 - 89) yrs with 72% > 55 yrs. RNA was isolated from 4×10 μm FFPE sections. Using real-time RT-PCR, 200 genes selected from van ‘t Veer et al, Dai et al, Paik et al and additional candidate genes were profiled. Primary endpoint was distant metastasis free survival. A prognostic signature was identified using semi-supervised principal component method. Metastasis score (MS) was calculated from gene expression levels. Results: We identified a unique 15-gene prognostic signature and 3 normalization genes. Probability of metastasis for any time period can be calculated from MS and was evaluated for 2, 5, and 10 yrs. Using median of MS to stratify patients, the high-risk group had a hazard ratio (HR) of 4.1 (95%CI 1.77–9.54, p = 0.001) vs. the low-risk group. 5-yr and 10-yr metastasis free survival rates (std. error) were 0.76 (0.053) and 0.62 (0.064) in the high-risk group and 0.96 (0.025) and 0.90 (0.038) in the low-risk group. Multivariate Cox regression analyses indicated that molecular signature had independent prognostic value with HR of 2.97 (95%CI 1.17 - 7.52, p = 0.022) after adjusting for age, tumor size and grade. Molecular signature was more prognostic in the low-grade subgroup (HR = 6.85, 95%CI 1.81–25.88) than an unstratified analysis. AUC at 5 yr was 0.65 and 0.60 for molecular signature and Adjuvant Online (AO) respectively. The prognosticator combining both had AUC of 0.67. 10-yr metastasis probabilities from MS and AO have low correlation (R2=0.17). Conclusions: A prognostic signature based upon mRNA expression of 15 genes has been identified using FFPE sections with RT-PCR for early stage, N-, ER+ patients. Metastasis score that quantifies distant metastasis risk for any time period, not confounded with any treatment effect, can help clinicians and patients to choose among different therapeutic options. (Lau and Wang contribute equally)

[Table: see text]

Hydrogenation of single-walled carbon nanotubes

Towards the development of a useful mechanism for hydrogen storage, we have studied the hydrogenation of single-walled carbon nanotubes with atomic hydrogen using core-level photoelectron spectroscopy and x-ray absorption spectroscopy. We find that atomic hydrogen creates C-H bonds with the carbon atoms in the nanotube walls, and such C-H bonds can be completely broken by heating to 600 degrees C. We demonstrate approximately 65 +/- 15 at % hydrogenation of carbon atoms in the single-walled carbon nanotubes, which is equivalent to 5.1 +/- 1.2 wt % hydrogen capacity. We also show that the hydrogenation is a reversible process.

No common denominator for breast cancer lymph node metastasis

The axillary lymph node status is the most powerful prognostic factor for breast cancer patients to date. The molecular mechanisms that control lymph node metastasis, however, remain poorly understood. To define patterns of genes or gene regulatory pathways that drive breast cancer lymph node metastasis, we compared the gene expression profiles of 15 primary breast carcinomas and their matching lymph node metastases using microarrays. In general, primary breast carcinomas and lymph node metastases do not differ at the transcriptional level by a common subset of genes. No classifier or single gene discriminating the group of primary tumours from those of the lymph node metastases could be identified. Also, in a series of 295 breast tumours, no classifier predicting lymph node metastasis could be developed. However, subtle differences in the expression of genes involved in extracellular-matrix organisation and growth factor signalling are detected in individual pairs of matching primary and metastatic tumours. Surprisingly, however, different sets of these genes are either up- or downregulated in lymph node metastases. Our data suggest that breast carcinomas do not use a shared gene set to accomplish lymph node metastasis.

Measurement of the flux of ultrahigh energy cosmic rays from monocular observations by the High Resolution Fly's Eye experiment

We have measured the cosmic ray spectrum above 10(17.2) eV using the two air-fluorescence detectors of the High Resolution Fly's Eye observatory operating in monocular mode. We describe the detector, phototube, and atmospheric calibrations, as well as the analysis techniques for the two detectors. We fit the spectrum to a model consisting of galactic and extragalactic sources.

Effects of diltiazem on platelet activation and cytosolic calcium during percutaneous transluminal coronary angioplasty

AIMS

To evaluate effects of diltiazem on platelet hyper-reactivity in situations associated with endothelial injury and their possible relationship to cytosolic calcium concentration.

METHODS

Blood samples were collected at seven time points from 35 patients undergoing percutaneous transluminal coronary angioplasty (PTCA) who received combined diltiazem and aspirin/ticlopidine therapy or aspirin/ticlopidine therapy alone. Platelet expression of glycoprotein IIb/IIIa and P-selectin, production of thromboxane B(2), and cytosolic calcium concentration were measured, respectively, by whole blood flow cytometry, radioimmunoassay, and fluorospectrophotometry. The effects of diltiazem of different concentrations on expression of glycoprotein IIb/IIIa and P-selectin were also studied in vitro in blood samples from patients with chronic stable angina.

RESULTS

Of the two treatments, aspirin/ticlopidine therapy did not prevent an acute increase of expression of glycoprotein IIb/IIIa and P-selectin and plasma thromboxane B(2) five minutes and 10 minutes after first inflation and 10 minutes after PTCA, whereas combined diltiazem and aspirin/ticlopidine therapy had a significant inhibitory effect. In the group receiving aspirin/ticlopidine therapy, there was a short term increase of platelet [Ca(2+)](i) immediately after PTCA which was significantly reduced by diltiazem treatment. Expression of glycoprotein IIb/IIIa and P-selectin was significantly inhibited in vitro by diltiazem in the concentration of 200 ng/ml or higher, but not 50 ng/ml.

CONCLUSIONS

Combined diltiazem and aspirin/ticlopidine therapy significantly inhibited platelet activation that continued in the presence of conventional aspirin/ticlopidine treatment. Antiplatelet effects of diltiazem were probably a consequence of reduction of platelet [Ca(2+)](i) and may only be achieved in higher than therapeutic concentrations.

[Immunological classification of 112 adult acute leukemia patients]

OBJECTIVE

To explore the criteria and significance of immunological classification in adult acute leukemias.

METHODS

One or two color monoclonal antibodies directly labeled with immunofluorescence were used to analyse the surface and cytoplasma antigens by flow cytometry, and an antibody integral system was developed for the immunologic classification.

RESULTS

One hundred and twelve adult acute leukemia cases were detected. (1) The undifferentiated phenotype account for 0.9%, simple 51.8%, variant 38.4% and mixed lineage 8.9%. (2) The abnormal expressions of antigen in variant and mixed lineage phenotype were CD7, CD33, CD10, CD13, CD19 and CD20, by order of decreased level.

CONCLUSION

The strict, numerical diagnostic criteria was very convenient and useful for immunophenotyping of adult acute leukemia.

Quantum interference and ballistic transmission in nanotube electron waveguides

The electron transport properties of well-contacted individual single-walled carbon nanotubes are investigated in the ballistic regime. Phase coherent transport and electron interference manifest as conductance fluctuations as a function of Fermi energy. Resonance with standing waves in finite-length tubes and localized states due to imperfections are observed for various Fermi energies. Two units of quantum conductance 2G(0) = 4e(2)/h are measured for the first time, corresponding to the maximum conductance limit for ballistic transport in two channels of a nanotube.

[Study on the elimination of bacterial endotoxins by ultrafiltration device]

An external-pressed polysulfone hollow fiber UF membrane, was made by phase inversion method. The cutoff molecular weight was 6000. The water permeation rate of this membrane module (psi 90 x 500 mm) is more than 150 L/hr.atm. The operating results show that the elimination of bacterial endotoxins by this membrane has reached the national standard in pharmacopoeia, and this technology is worthy to be extended over to medical industry. In addition, the essence of pyreotogen, the quantification units and measure methods for pyreotogen, and the operating conditions of UF device in the process of eliminating pyreotogen are introduced. Some critical points in operation was discussed.

[Study on the immunologic function of lymphocyte in cord blood]

OBJECTIVE

To explore immunologic function of T lymphocytes in human cord blood (HUCB) and provide theoretical basis for clinical application of HUCB.

METHODS

Immunophenotype and co-stimulated molecules were detected by flow-cytometry using a panel of double labelled McAb, intracellular cytokines (interferon-gamma, interleukin-4) secreted by T lymphocytes by micro-culture of whole blood, and CD25 expression of T lymphocyte by PHA stimulation. T lymphocytes from adult peripheral blood (PB) were used as control.

RESULTS

There are a higher CD4+/CD8+ ratio of T subset and a lower percentage of CD8+ lymphocytes in HUCB than that in adult PB (P < 0.01), and more than 90% of HUCB T-cells co-expressed CD45RA naive antigen which was significant higher than the percentage in adult PB (P < 0.01). The percentages of IFN-gamma and IL-4-producing CD4+ and CD8+ T cells from HUCB were lower than that of the control group. T cells in HUCB were able to be activated by PHA, but the phases of activation differed from adult PB T cells.

CONCLUSIONS

It suggested that the low ability to secret cytokines and high percentage of naive T cells might be responsible for the decreased incidence of acute and chronic GVHD and provided possible explanation for the clinical result in HUCB transplantation. T cells in HUCB is a potential resource of adoptive immunotherapy.

[Detection of telomerase activity in laryngeal carcinoma and the association between telomerase activity and lymphatic metastasis]

OBJECTIVE

To investigate the telomerase activity in human laryngeal squamous cell carcinomas (LSCC) and the association between telomerase activity and lymphatic metastasis.

METHOD

Telomerase activity was determined in 47 specimens of LSCC and 10 specimens of laryngeal inflammatory polyps using PCR-ELISA.

RESULT

Telomerase activity was detected in 39 of 47 (83%) LSCC, but was not detected in all 10 laryngeal inflammatory polyps. There were significant differences between them (P < 0.01). Telomerase activation in LSCC with positive cervical lymph node involvement appeared to be higher (13 out of 13 cases, 100%) than in LSCC with negative cervical lymph node involvement (26 out of 34, 76.47%), (P < 0.05).

CONCLUSION

Telomerase is activated frequently in LSCC and may become a biomarker of LSCC. The detection of telomerase activity in LSCC may have some value for predicting metastasis potential and prognosis and can guide the clinical practices applying selective neck dissection.

[Changes in respiratory and circulatory function during sequential invasive-noninvasive mechanical ventilation]

OBJECTIVE

To investigate the change of respiratory and circulatory function in COPD during sequential invasive-noninvasive mechanical ventilation.

METHODS

12 COPD patients with type II respiratory failure were ventilated via endotracheal intubation. When pulmonary infection was under control (the appearance of "PIC Window"), all patients were extubated and received mask ventilation. The parameters of hemodynamics oxygenation and esophageal pressure were measured during endotracheal ventilation and mask ventilation (3 hrs after extubation).

RESULTS

The change of respiratory and circulatory parameters were not significantly different between invasive mechanical ventilation and noninvasive mechanical ventilation (P > 0.05).

CONCLUSION

The respiratory and circulatory function of COPD patients remained stable during sequential invasive-noninvasive mechanical ventilation.

[Stress response of Nilaparvata lugens at high temperature and activities of its protective enzyme systems]

The nymphae and different wing-form adults of Brown Planthopper (BPH) were treated intermittently at 34 degrees C, 36 degrees C and 38 degrees C. During the process of heat shock treatment, the variation of the activities of the endogenous enzymes of protective system and the content of lipid peroxides (LPO) in BPH were researched. The results showed that the effect of heat shock treatments on CAT activity in 4th instar of nymphae was higher than that in 3rd and 5th instar. The CAT activity in BPH adults increased with the day-age, and 36 degrees C was the suitable temperature at which H2O2 was scavenged by CAT. The GSH-px activity was higher in old than that in young nymphae, and the ability of GSH-px to scavenge H2O2 was higher in old adults than in those adults emerged early. The activity of SOD had a positive correlation with the treated temperatures, and decreased with the increase of nymphae instar and the day-age of adults after emergence at the same temperature. The activities of CAT, GSH-px, and SOD in macropterous adults were higher than those in brachypterous adults. There were no significant difference for the activities of CAT, GSH-px and SOD between female and male adults (alpha > 0.05). The content of LPO in BPH increased with the rise of treated temperature, and also increased with the increase of instars in nymphae and day-age after emergence in adults at the same temperature. The LPO content was higher in brachypterous than in macropterous adults.

[Validation and comparison of ISO standard method for the examination of fluoride in drinking water]

The validation of ISO standard method for the examination of fluoride in drinking water was introduced. The test for compensating interference, standard curves, accuracy, precision and the minimum detection limit etc were included. The comparison between ISO method and others was made. The results indicated that the ISO method was better in anti-interference, wider linear range and higher precision. The points designed were reasonable. The method is superior to other methods in the same kind, and it should be adopted and extended.

[Predictive value of combined application of umbilical artery color Doppler velocimetry, nonstress testing and ultrasonography in monitoring umbilical cord entanglement]

OBJECTIVE

To explore the predictive value of combined application of umbilical artery color Doppler flow monitoring (CDFI), nonstress testing (NST) and ultrasonography in monitoring umbilical cord entanglement.

METHODS

1 860 cases of pregnant women between gestational ages of 37 approximately 42 weeks were studied 1 approximately 2 weeks before delivery by CDFI, nonstress testing (NST) and ultrasonography to monitor umbilical cord entanglement.

RESULTS

The prevalence rate of umbilical cord entanglement was 23.23% (432/1 860). Positive predictive value and negative predictive value were 95.4 % (412/432) and 98.6% (1 408/1 428) respectively. The rate of accuracy was 97.8% (1 820/1 860). The rate of fetal distress among the fetuses with umbilical cord round the body or four limbs was 85.29% (23/34) and the incidence of cesarean section in this group was 88.28% (30/34). The rate of fetal distress among the fetuses with umbilical cord round the neck was 13.06% (52/398) and the incidence of cesarean section in this group was 44.94% (178/398). The rates of fetal distress and cesarean section were significantly higher in the group with umbilical cord around the body or four limbs than in the group with umbilical cord around the neck (chi(2) = 107.27 and 23.76 respectively, P < 0.001). The systolic/diastolic (S/D) ratio was basically in normal ranges in the group with the umbilical cord round the neck. In cardiotopography (CTG), umbilical cord entanglement mainly showed variable deceleration (VD), early deceleration (ED), nonreaction on NST, and late deceleration (LD) on oxytocin challenge test (OCT). Prolonged fetal heart rate deceleration (PD) could be seen in the group with umbilical cord around the body or four limbs.

CONCLUSION

The combined application of umbilical artery color Doppler velocimetry, nonstress testing and ultrasonography have an important auxiliary value in monitoring umbilical cord entanglement. It remarkably increases the positive predictive rate as a valuable reference for the choice of delivery form.

Expression profiling using microarrays fabricated by an ink-jet oligonucleotide synthesizer

We describe a flexible system for gene expression profiling using arrays of tens of thousands of oligonucleotides synthesized in situ by an ink-jet printing method employing standard phosphoramidite chemistry. We have characterized the dependence of hybridization specificity and sensitivity on parameters including oligonucleotide length, hybridization stringency, sequence identity, sample abundance, and sample preparation method. We find that 60-mer oligonucleotides reliably detect transcript ratios at one copy per cell in complex biological samples, and that ink-jet arrays are compatible with several different sample amplification and labeling techniques. Furthermore, results using only a single carefully selected oligonucleotide per gene correlate closely with those obtained using complementary DNA (cDNA) arrays. Most of the genes for which measurements differ are members of gene families that can only be distinguished by oligonucleotides. Because different oligonucleotide sequences can be specified for each array, we anticipate that ink-jet oligonucleotide array technology will be useful in a wide variety of DNA microarray applications.

Longitudinal changes in pulmonary function and respiratory symptoms in cotton textile workers. A 15-yr follow-up study

To evaluate the chronic effects of exposure to cotton dust, a 15-yr follow-up study in cotton textile workers was performed in Shanghai, China from 1981 to 1996. Testing occurred four times during the 15-yr period. The achieved follow-up rates were 76-88% of the original 447 cotton textile workers, and 70-85% of the original 472 silk textile workers (as a control group). Identical questionnaires, equipment, and methods were used throughout the study. The prevalence of byssinosis increased over time in cotton workers, with 15.3% at the last survey versus 7.6% at the baseline, whereas no byssinosis was found in silk workers. More workers in the cotton group consistently reported symptoms than in the silk group, although symptom reporting varied considerably from survey to survey. Cotton workers had small, but significantly greater, adjusted annual declines in FEV(1) and FVC than did the silk workers. Years worked in cotton mills, high level of exposure to endotoxin, and across-shift drops in FEV(1) were found to be significant determinants for longitudinal change in FEV(1), after controlling for appropriate confounders. Furthermore, there were statistically significant associations between excessive loss of FEV(1) and byssinosis, chest tightness at work, and chronic bronchitis in cotton workers. Workers who consistently (three or four of the surveys) reported byssinosis or chest tightness at work had a significantly greater 15-yr loss of FEV(1). We conclude that long-term exposure to cotton dust is associated with chronic or permanent obstructive impairments. Consistent reporting of respiratory symptoms, including byssinosis and chest tightness at work, is of value to predict the magnitude and severity of chronic impairments in textile workers.

Experimental annotation of the human genome using microarray technology

The most important product of the sequencing of a genome is a complete, accurate catalogue of genes and their products, primarily messenger RNA transcripts and their cognate proteins. Such a catalogue cannot be constructed by computational annotation alone; it requires experimental validation on a genome scale. Using 'exon' and 'tiling' arrays fabricated by ink-jet oligonucleotide synthesis, we devised an experimental approach to validate and refine computational gene predictions and define full-length transcripts on the basis of co-regulated expression of their exons. These methods can provide more accurate gene numbers and allow the detection of mRNA splice variants and identification of the tissue- and disease-specific conditions under which genes are expressed. We apply our technique to chromosome 22q under 69 experimental condition pairs, and to the entire human genome under two experimental conditions. We discuss implications for more comprehensive, consistent and reliable genome annotation, more efficient, full-length complementary DNA cloning strategies and application to complex diseases.

Yersinia enterocolitica O9 as a possible barrier against Y. pestis in natural plague foci in Ningxia, China

A survey of Yersinia spp, as related to plague control, was made in Haiyuan of Ganning loess plateau plague focus, Yanchi of Inner Mongolia plateau plague focus, and Yinchuan city, as a control area, in Ningxia, China. In Haiyuan, where the main plague reservoir was Mongolian ground squirrel (Citellus alaschanicus) living in the prairie, Y. enterocolitica O9 was frequently isolated from pigs, dogs, rodents living in and around houses, but only rarely from hare and Mongolian ground squirrel. In Yanchi, where the main plague reservoir was Mongolian gerbil (Meriones unguiculatus) living in the prairie and Y. pestis, which was isolated from rodents up to 1991, Y. enterocolitica O9 was sometimes isolated from pigs and rodents. In all areas, some strains of Y. enterocolitica O3 and Y. pseudotuberculosis serotypes 3 and 4b were also isolated from pigs, dogs, and from rodents. We propose that an epidemiological link exists between the prevalence of Y. pestis and Y. enterocolitica O9 in domestic and rodents living in these areas in China. The residential area in Haiyuan may be protected against Y. pestis by the domestic animals and rodents which acquired cross-protection against Y. pestis by infection with Y. enterocolitica O9, but this is not the case in the Yanchi district.

Modulated chemical doping of individual carbon nanotubes

Modulation doping of a semiconducting single-walled carbon nanotube along its length leads to an intramolecular wire electronic device. The nanotube is doped n-type for half of its length and p-type for the other half. Electrostatic gating can tune the system into p-n junctions, causing it to exhibit rectifying characteristics or negative differential conductance. The system can also be tuned into n-type, exhibiting single-electron charging and negative differential conductance at low temperatures. The low-temperature behavior is manifested by a quantum dot formed by chemical inhomogeneity along the tube.

The zinc finger protein schnurri acts as a Smad partner in mediating the transcriptional response to decapentaplegic

In Drosophila, a BMP-related ligand Decapentaplegic (Dpp) is essential for cell fate specification during embryogenesis and in imaginal disc development. Dpp signaling culminates in the phosphorylation and nuclear translocation of Mothers against dpp (Mad), a receptor-specific Smad that can bind DNA and regulate the transcription of Dpp-responsive genes. Genetic analysis has implicated Schnurri (Shn), a zinc finger protein that shares homology with mammalian transcription factors, in the Dpp signal transduction pathway. However, a direct role for Shn in regulating the transcriptional response to Dpp has not been demonstrated. In this study we show that Shn acts as a DNA-binding Mad cofactor in the nuclear response to Dpp. Shn can bind DNA in a sequence-specific manner and recognizes sites within a well-characterized Dpp-responsive promoter element, the B enhancer of the Ultrabithorax (Ubx) gene. The Shn-binding sites are relevant for in vivo expression, since mutations in these sites affect the ability of the enhancer to respond to Dpp. Furthermore we find that Shn and Mad can interact directly through discrete domains. To examine the relative contribution of the two proteins in the regulation of endogenous Dpp target genes we developed a cell culture assay and show that Shn and Mad act synergistically to induce transcription. Our results suggest that cooperative interactions between these two transcription factors could play an important role in the regulation of Dpp target genes. This is the first evidence that Dpp/BMP signaling in flies requires the direct interaction of Mad with a partner transcription factor.

[The effect of HCPT combined with radiation on cell proliferation of human lung adenocarcinoma cell line (D₆) in vitro]

BACKGROUND

To study the adjuvant effects of HCPT and radiation on cell proliferation of human lung adenocarcinoma cell line (D₆) in vitro.

METHODS

Suppression rate of cell growth,apoptosis and cell cycle of human pulmonary adenocarcinoma cell line were detected by MTT assay,DNA agrose electrophoresis and flow-cytometry respectively.

RESULTS

The suppression effects of HCPT on cell proliferation were dose and time dependent.The cells were significantly blocked at S stage by HCPT.Apoptosis peak appeared at 24 and 48 hours after treatment with high concentration (50μg/ml) and low concentration of HCPT (1μg/ml) respectively.DNA "Ladder" started to appear at 48 hours by radiation alone,but DNA "Ladder" and apoptosis peak both appeared at 24-72 hours and 0-72 hours after treatment with HCPT alone and HCPT combined with radiation respectively.

CONCLUSIONS

HCPT combined with radiation may show the synergistic killing effect on human lung adenocarcinoma cell line (D₆) in vitro.

[The meridian flowing and ancient Chinese philosophy]

The theories of Yin - Yang and Five - Evolutive phase were extensively applied after pre - Qin and both Han dynasties. In the Song - Ming dynasties, the background of New Confucianism, the achievements of art of Yi(Changes) advocated by the "School of Configuration - Arithmatic" were applied, in which the method of "Adopting of Jia" was almost entirely derived from the above school, mixing the theories of heavenly stems - earthly branches, Five - evolutive phases and Yin - Yang as a whole. An ancient system of Chronological treatment was thus established creatively by integrating clinical experience together. The system is a tight system of grafting medicine and philosophy formed on the basis of successfully utilizing the philosophical framework, thinking proposed by ancient physicians with keen observation and deep ponderation. The system is, by then, an advanced one, which is also an inevitable one.

[Detection of soluble endothelial protein C receptor (sEPCR) in patients with CHD, DM and SLE]

OBJECTIVE

To evaluate the clinical significance of plasma soluble endothelial protein C receptor (sEPCR) level in patients with coronary heart disease (CHD), diabetes mellitus (DM) and systemic lupus erythematosus (SLE).

METHODS

ELISA of antibody-sandwiched principle was used to detect sEPCR in 34 patients with CHD, 42 with DM-II, 63 with SLE and 20 normal controls (NC).

RESULTS

The plasma level of sEPCR in patients with DM was higher than that in NC group (P < 0.05). The sEPCR level in SLE patients with thrombosis and non-thrombosis are higher than that in NC group (P < 0.005 and P < 0.001, respectively). There is no significant difference between the two groups of SLE (P > 0.05), and between the CHD and NC groups.

CONCLUSION

sEPCR level increased in DM and SLE, it seems related to the process of inflammatory reaction and damage of endothelial cell.

Functional discovery via a compendium of expression profiles

Ascertaining the impact of uncharacterized perturbations on the cell is a fundamental problem in biology. Here, we describe how a single assay can be used to monitor hundreds of different cellular functions simultaneously. We constructed a reference database or "compendium" of expression profiles corresponding to 300 diverse mutations and chemical treatments in S. cerevisiae, and we show that the cellular pathways affected can be determined by pattern matching, even among very subtle profiles. The utility of this approach is validated by examining profiles caused by deletions of uncharacterized genes: we identify and experimentally confirm that eight uncharacterized open reading frames encode proteins required for sterol metabolism, cell wall function, mitochondrial respiration, or protein synthesis. We also show that the compendium can be used to characterize pharmacological perturbations by identifying a novel target of the commonly used drug dyclonine.

Prevalence of Alzheimer's disease and other dementing disorders in an urban community of Beijing, China

A door-to-door two-phase study was used to investigate the prevalence of senile dementia in an urban community of Beijing. In the study population, 5,003 individuals aged 60 years and older (>/=65 years, n = 3,728) were screened at home with the Chinese version of the MMSE. Persons who screened positive for dementia, using different cutoff scores based on degree of literacy, were further evaluated using the criteria of DSM-III-R and ICD-10. Among subjects who screened positive in phase I, 134 were diagnosed as having dementia in phase II. The prevalence ratios of dementia were 2.68% in the population aged 60 years and older, and 3.49% in the population aged 65 years and older. The prevalence rates among those aged 65 years and older were 1.85% for Alzheimer's disease, 1.37% for vascular dementia and 0.27% for other dementia (including mixed dementia). The prevalence of all dementia and AD increased steeply with advancing age and was consistently higher in women, but it was not obviously higher for VaD in women. Alzheimer's disease was the commonest type of dementia. Our prevalence figures for dementia and AD are similar to those previously reported for China.

Widespread aneuploidy revealed by DNA microarray expression profiling

Expression profiling using DNA microarrays holds great promise for a variety of research applications, including the systematic characterization of genes discovered by sequencing projects. To demonstrate the general usefulness of this approach, we recently obtained expression profiles for nearly 300 Saccharomyces cerevisiae deletion mutants. Approximately 8% of the mutants profiled exhibited chromosome-wide expression biases, leading to spurious correlations among profiles. Competitive hybridization of genomic DNA from the mutant strains and their isogenic parental wild-type strains showed they were aneuploid for whole chromosomes or chromosomal segments. Expression profile data published by several other laboratories also suggest the use of aneuploid strains. In five separate cases, the extra chromosome harboured a close homologue of the deleted gene; in two cases, a clear growth advantage for cells acquiring the extra chromosome was demonstrated. Our results have implications for interpreting whole-genome expression data, particularly from cells known to suffer genomic instability, such as malignant or immortalized cells.

Intrinsic electrical properties of individual single-walled carbon nanotubes with small band gaps

Individual single-walled carbon nanotubes (SWNT) exhibiting small band gaps on the order of 10 meV are observed for the first time in electron transport measurements. Transport through the valence or conduction band of a small-gap semiconducting SWNT (SGS-SWNT) can be tuned by a nearby gate voltage. Intrinsic electrical properties of the Ohmically contacted SGS-SWNT are elucidated. An SGS-SWNT exhibits metal- or semiconductorlike characteristics depending on the Fermi level position in the band structure.

Controllable reversibility of an sp(2) to sp(3) transition of a single wall nanotube under the manipulation of an AFM tip: A nanoscale electromechanical switch?

A simulation of the deflection of a single wall nanotube under the manipulation of an atomic force microscope tip revealed the key feature characterizing the deformation at relatively small bending angles to be a reversible transition from sp(2) to sp(3) bonding configurations in the bending region, leading to a 2 orders of magnitude reduction in conductance consistent with our most recent experimental observation. A local analysis elucidating the underlying physics of the findings is also discussed.

Probing the roles of the only universally conserved leucine residue (Leu122) in the oligomerization and chaperone-like activity of Mycobacterium tuberculosis small heat shock protein Hsp16.3

To understand the role of the only universally conserved hydrophobic residue among all the members of the sHsp family, this extremely well conserved Leu122 residue in Hsp16.3 was replaced by valine, alanine, asparigine, or aspartate residues. Only very small amounts of the L122D and L122N mutant Hsp16.3 proteins were expressed in the transformed E. coli; however, both the L122V and L122A were readily expressed. The L122V and L122A mutant proteins had similar oligomeric structures to the wild-type protein at room temperature. Examination of the L122A mutant protein by native pore gradient PAGE and CD spectroscopy, however, revealed a smaller oligomeric size and different secondary structure at 37 degrees C. Both L122V and L122A mutant proteins exhibited significantly lowered chaperone activities. Observations reported here suggest a very important role of this only universally conserved Leu residue in both the formation of specific oligomeric structures and the molecular chaperone activities of Hsp16.3.

[Expression of telomerase activity in human lung cancer.]

BACKGROUND

To investigate the expression of telomerase activity in lung cancer tissue and the correlation with the oncogenesis , progression and metastasis of lung cancer.

METHODS

Telomerase activity in specimens obtained by fiberbrochoscopy from 29 patients with suspected lung cancer was detected by polymerase chain reaction-ELISA.

RESULTS

The telomerase activity was positive in 18 cases of primary lung cancer and the positive rate was 81. 81 %(18/ 22) . Two of other seven specimens were positive for telomerase activity. Twelve lung cancer cases with lymph node metastasis showed positive expression , whereas only 6 of 10 cases without lymph node metastasis showed positive expression.

CONCLUSIONS

Telomerase activity may be useful both as a diagnostic marker to detect the existence of lung cancer and as a potential of high risk for lymph node metastasis.

A complex containing both trypsin inhibitor and dehydroascorbate reductase activities isolated from mitochondria of etiolated mung bean (Vigna radiata L. (Wilczek) cv. Tainan no. 5) seedlings

A complex containing trypsin inhibitor (TI) activity was extracted with 0.1 M TRIS buffer (pH 7.9) from trypsin-treated mitochondria of etiolated mung bean seedlings, and further purified with a Superdex 200 FPLC column. This partially purified complex with an M(r) about 820 kDa exhibited additional dehydroascorbate (DHA) reductase activity with specific activities of 0.21, 1.53 and 1.54 mumol ascorbate formed min-1 mg-1 protein at pH 6.0, 6.5 and 7.0, respectively, when glutathione was added. Much lower DHA reductase activity (0.013 and 0.026 mumol ascorbate formed min-1 mg-1 protein at pH 6.5 and 7.0, respectively) was found when glutathione was omitted. The isolated complex gave positive results when it was tested by TI activity staining after SDS-PAGE, and could be recognized by a polyclonal antibody which was raised against 38 kDa sweet potato Kunitz-type TI, one of the root storage proteins of sweet potato. The possible physiological functions of this complex with both TI and DHA reductase activities were discussed.

Frequency of SCA1, SCA2, SCA3/MJD, SCA6, SCA7, and DRPLA CAG trinucleotide repeat expansion in patients with hereditary spinocerebellar ataxia from Chinese kindreds

OBJECTIVE

To assess the frequency of SCA1 (spinocerebellar ataxia type 1), SCA2, SCA3/MJD (spinocerebellar ataxia type 3/Machado-Joseph disease), SCA6, SCA7, and DRPLA (dentatorubropallidoluysian atrophy) CAG trinucleotide repeat expansions [(CAG)n] among persons diagnosed with hereditary SCA from Chinese families.

PATIENTS AND METHODS

Spinocerebellar ataxia type 1, SCA2, SCA3/MJD, SCA6, SCA7, and DRPLA (CAG)n mutation were detected with the polymerase chain reaction, highly denaturing polyacrylamide gel electrophoresis, and silver staining technique in 167 patients with autosomal dominant SCA from 85 Chinese families and 37 patients with sporadic SCA.

RESULTS

Spinocerebellar ataxia type 1 (CAG)n mutation in 7 patients from 4 kindreds (4.70%) was expanded to 53 to 62 repeats. Spinocerebellar ataxia type 2 (CAG)n mutation in 12 patients from 5 kindreds (5.88%) was expanded to 42 to 47 repeats. Spinocerebellar ataxia type 3/Machado-Joseph disease (CAG)n mutation in 83 patients from 41 kindreds (48.23%) was expanded to 68 to 83 repeats. Sixty-five patients from 35 kindreds (41.19%) and 37 patients with sporadic SCA did not test positive for SCA1, SCA2, SCA3/MJD, SCA6, SCA7, or DRPLA. There was a predictable inverse relationship between the number of CAG repeats and the age at onset for SCA3/MJD and SCA2. Clinically, dementia and hyporeflexia were more frequent in patients with SCA2, while spasticity, hyperreflexia, and Babinski signs were more frequent in patients with SCA3/ MJD, and those might be helpful in clinical work to primarily distinguish patients with SCA3/MJD and SCA2 from others with different types of SCA.

CONCLUSIONS

The frequency of SCA3/MJD is substantially higher than that of SCA1 and SCA2 in patients with autosomal dominant SCA from Chinese kindreds, who are non-Portuguese. Clinical expressions of the various types of SCAs overlap one another; therefore, for clinical study it is important to make a gene diagnosis and genetic classification for patients with SCA.

[Research in the relationship between Chlamydia and ureaplasma and infertility]

Samples taken from cervix and male urethra of 768 infertilitas patients were studied, and samples taken from 226 normal fertile males and females served as control. The fluorescent monoclonal antibody technique and cell culture method were used for Chlamydia trachomatis (Ct) and microbiological culture method was used for Ureaplasma urealyticum (Uu) detection. The positive rates of Ct and Uu infections were 28.64% (220/768) and 36.59% (281/768) in infertilitas group, 5.2% (14/266) and 14.28% (38/266) in control group respectively. There was significant difference between the 2 groups (P < 0.01). The results suggest that infection with Ct or Uu is one of the factors causing infertility.

[Vitrectomy for pseudophakic retinal detachment]

OBJECTIVE

To study the method of vitrectomy for treatment of pseudophakic retinal detachment.

METHODS

32 pseudophakic retinal detachment eyes were treated with vitrectomy, primary vitrectomy in 11 eyes (34.4%), vitrectomy after conventional buckling failure in 21 eyes (65.6%), combined with silicone oil 10 eyes (31.3%), removal of intraocular lens 12 eyes (37.5%). All eyes had passed the 6 months to 5 years of follow-up examination.

RESULTS

Intra-operative new retinal breaks were identified in 7 eyes (21.9%). The retinal total reattachment was in 25 eyes (78.1%); part reattachment was in 4 eyes (12.5%), and their visual acuity was improved than that before the operation. Due to severe proliferative vitreoretinopathy (PVR), failure occurred in 3 eyes.

CONCLUSIONS

The main advantage of vitrectomy is the better intra-operative sight to the peripheral retinal breaks, removal of retinal traction and the low rate of PVR after vitrectomy. Vitrectomy for complicated type of pseudophakic retinal detachment can improve the success rate of the retinal detachment surgery and the visual acuity outcome.

[Adaptation of insect cells(BTI-Tn-5B1-4) to serum-free culture]

The insect cells(BTI-Tn-5B1-4) were adapted, from the medium supplemented with 5% FBS, via 3%, 2%, 1% FBS, to grow in serum-free medium by sequential adaptation for about three months. After adaptation, the cells could successfully grow in the specifically designed serum-free medium with the viability above 90%. In addition, the effect of FBS concentrations and inoculum sizes on the insect cell growth was also investigated.

Signaling and circuitry of multiple MAPK pathways revealed by a matrix of global gene expression profiles

Genome-wide transcript profiling was used to monitor signal transduction during yeast pheromone response. Genetic manipulations allowed analysis of changes in gene expression underlying pheromone signaling, cell cycle control, and polarized morphogenesis. A two-dimensional hierarchical clustered matrix, covering 383 of the most highly regulated genes, was constructed from 46 diverse experimental conditions. Diagnostic subsets of coexpressed genes reflected signaling activity, cross talk, and overlap of multiple mitogen-activated protein kinase (MAPK) pathways. Analysis of the profiles specified by two different MAPKs-Fus3p and Kss1p-revealed functional overlap of the filamentous growth and mating responses. Global transcript analysis reflects biological responses associated with the activation and perturbation of signal transduction pathways.

On the relative influence of individual harmonics on pitch judgment

Spectral weighting functions were estimated in a pitch-comparison task to assess the relative influence of individual harmonics on listeners' pitch judgment. The stimuli were quasi-harmonic complex tones composed of the first 12 components, with fundamental frequencies ranging from 100 to 800 Hz. On each stimulus presentation the frequency of each harmonic was randomly jittered by a small amount. The perceptual weight for each harmonic was calculated as the correlation coefficient between the binary responses of the listener and the frequency jitters for that harmonic. Although in general the present results conform to previous ones showing the predominant role of several low-ranked harmonics, discrepancies exist in details. Contrary to some previous reports that the dominant harmonics were of fixed harmonic ranks regardless of their frequencies, the current results showed that the dominant harmonics were best described as close to a fixed absolute frequency of 600 Hz.

[Molecular cytogenetics study in a case with unbalanced chromosome translocation]

OBJECTIVE

To analyze the chromosome structural aberration in a case of unbalanced chromosome translocation by fluorescence in situ hybridization technique.

METHODS

The 1,18 whole chromosome specific painting probe were used to confirm chromosome abnormality suggested by high resolution G-banding examination.

RESULTS

An unbalanced translocation t(1;18)(q42;q22) was detected in the patient, which caused partial trisomy of 1q42-qter and partial monosomy of 18q22-qter.

CONCLUSION

The identified translocation suggested a potential site for congenital heart disease.