Flexible CO2 laser system for fundamental research related to an extreme ultraviolet lithography source

A CO(2) laser system with flexible parameters was developed for fundamental research related to an extreme ultraviolet (EUV) lithography source. The laser is a master oscillator and power amplifier (MOPA) system, consisting of a master oscillator, an externally triggered plasma switch, a preamplifier, a main amplifier, and electronic synchronization units. The laser pulse duration can be varied easily from 10 to 110 ns, with a constant peak power for pulse durations from 25 to 110 ns. The MOPA laser system can also be operated in dual-oscillator mode to produce laser pulse with pulse duration as long as 200 ns and a train of laser pulses with flexible interval. The divergence of the laser beam is 1.3 times the diffraction limit. The laser intensity on the target surface can be up to 8x10(10) W/cm(2). Utilizing this CO(2) MOPA laser system, high conversion efficiency from laser to in-band (2% bandwidth) 13.5 nm EUV emission has been demonstrated over a wide range of laser pulse durations.

Osteoporosis in china

SUMMARY

Based on related studies published between 1980 and May 2008, we examine the prevalence of osteoporoses in mainland China, Hong Kong, and Taiwan. Overall, the prevalence of osteoporosis among these Chinese populations remains low compared to other Caucasian populations; in the mainland, it was approximately 13%.

INTRODUCTION

Osteoporosis is a significant public health problem and has received great attention in industrialized countries. However, limited is known in many developing countries including China, where aging and changing lifestyles likely contribute to increased osteoporosis. The objectives of the study is to examine the disease burden (prevalence) and time trends of osteoporosis in mainland China, Hong Kong, and Taiwan.

METHODS

Related studies published in English and Chinese between January 1980 and May 2008 were reviewed and analyzed.

RESULTS

The prevalence increased with age and varied dramatically based on local versus international diagnosis criteria. In the mainland, reported overall prevalence of osteoporosis based on nationwide surveys ranged from 6.6% to 19.3% (average = 13.0%). The prevalence varied considerably across studies, and by regions, gender, and bone sites, but the urban to rural difference was small. In Hong Kong, the prevalence among women > or =50 years ranged from 34.1-37% in the spine; was 7% in the same aged men. In Taiwan, among those aged > or =50 years, average prevalence of osteoporosis was 11.4% in women and 1.6% in men.

CONCLUSIONS

Future national programs need to monitor the burden of osteoporosis in China though available data indicate that the prevalence of osteoporosis remains low compared to that of other Caucasian populations.

Distribution of HLA-A, -B, -Cw, and -DRB1 alleles and haplotypes in an isolated Han population in Southwest China

In this study, polymorphisms of human leukocyte antigen (HLA) class I (A, B, and Cw) and class II (DRB1) loci were analyzed in an isolated Han population living in Fengyandong in the Yunnan province of Southwest China (FYDH) using a high-resolution polymerase chain reaction-Luminex typing method. A total of 13 A, 26 B, 15 Cw, and 23 DRB1 alleles of HLA were found in FYDH. The frequencies of A*1101, A*0207, A*2402, B*4601, B*1502, Cw*0102, Cw*0801, DRB1*0901, and DRB1*1202 were >10%. The following haplotypes were common with frequencies >5%: three A-B, four Cw-B, two B-DRB1, two A-B-DRB1, three A-B-Cw, two B-Cw-DRB1, and two A-B-Cw-DRB1 phylogenetic tree and multidimensional scaling analysis based on HLA-A, -B, and -DRB1 allele frequencies of 18 Han populations suggested that FYDH was an isolated Han population, but the analytic result also provided a suggestion that FYDH was genetically related to Chinese Southern Han. According to the characteristics of the HLA allele and haplotype distributions and significantly reduced allelic and haplotypic diversity in FYDH, we deduced that genetic drift and/or selection and subsequent geographic isolation had influenced the distribution characteristics of the HLA gene in FYDH. In addition, significantly reduced allelic and haplotypic diversity in FYDH makes it an ideal homogenous population and very useful model for future investigations of issues related to immunogenetic diseases in the Han population.

Knockdown of Abl interactor 1 expression impairs invadopodia formation, tumor angiogenesis, and markedly slows tumor growth of breast cancer cells

Abstract #2054

Background: Abl interactor 1 (Abi1) is a key regulator of actin polymerization/depolymerization. Previous studies have revealed that Abi1 interacts with Wiskott–Aldrich syndrome protein (Wasp) family proteins, and regulates the nucleation promoting activity of Wasp proteins. In addition to Wasp family proteins, Abi1 also binds to a variety of other signaling molecules, including those involved in the signal transductions of small GTP-binding protein Rac and PI3 kinase. The ability to interact with diverse signaling pathways places Abi1 at a central position in the signaling network that regulates cell motility and proliferation. The involvement of Abi1 in the development of abnormal cytoskeletal functions of cancer cells has recently been reported. It remains unclear, however, how Abi1 exerts its effects in tumor cells and whether it contributes to tumor progression in vivo.
 Material and Methods: The short hairpin RNA (shRNA)-mediated gene silencing was used, in conjunction with murine tumor xenograft models, to examine the effects of Abi1 knockdown on cytoskeleton remodeling, cell migration, invasion, as well as tumor growth and angiogenesis of MDA-MB231 breast cancer cells.
 Results: We report here a novel function for Abi1 in the regulation of invadopodia formation as well as in the tumor angiogenesis and invasion of breast cancer cells, possibly through the modulation of Src and matrix metalloproteinase 9 (MMP-9) activities. Abi1 co-localizes with invadopodia, the specialized adhesive/invasive structures believed to control the invasion of tumor cells, in MDA-MB231 breast cancer cells. Epigenetic silencing of the Abi1 gene by shRNA in MDA-MB231 cells impaired the formation of invadopodia and decreased the activity of c-Src and MMP-9. The decreased invadopodia formation and MMP-9 activity correlated with a reduction in the ability of these cells to degrade extracellular matrix (ECM). Remarkably, the knockdown of Abi1 expression inhibited tumor invasion and angiogenesis and markedly slowed tumor growth in xenograft mouse models. Taken together, these results indicate that the Abi1 signaling plays a critical role in breast cancer progression and suggest that this pathway may serve as a therapeutic target for the treatment of human breast cancer.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 2054.

A comparative genomic analysis between human breast cancer and paired tumor lines derived from transplanation of tumor biopsies into NOD/SCID mice

Abstract #41

Background: Successful preclinical studies of experimental anticancer agents require model systems that recapitulate breast cancer biology and genomic abnormalities as accurately as possible. The use of primary human tumor explants engrafted into the humanized mammary fat pad of NOD SCID mice (HIM technique for "human in mouse") is promising in this regard, but the evidence that the genomic profile of the tumor is stable during serial translatation of human tumors into mice and between mouse passages has not beeen clearly demonstrated.
 Methods: 4th mammary glands of NOD/SCID mice were humanized by removing mouse mammary epithelia and implanting immortalized human breast fibroblasts. Human breast tumor tissues were dissociated into single cell suspensions and injected into the “humanized” mammary fat pads of NOD/SCID mice. Patient tumors were micro-dissected from the surrounding normal tissue by laser capture microdissection and tumor RNA and DNA was isolated. In addition, tumor RNA and DNA was isolated from xenografts at passage 1, 2, and 3. Agilent 4 x 44K whole genome expression array and 244K array-based comparative genomic hybridization (aCGH) was performed on established xenografts (passage 1-3) as well as the original tumor samples. Exon 9 and 20 of PIK3CA and exon 4 to 9 of TP53 were targeted for mutation detection since these genes are commonly mutated in human breast cancer.
 Results: To date, eight HIM tumor lines have been successfully established and serially passaged. The HIM number and source of tumor are as follows: HIM2 (primary tumor); HIM 3 (primary tumor); HIM 4 (abdominal wall metastasis); HIM 5 (brain metastasis from the patient used to establish HIM 2); HIM6 (primary breast cancer); HIM7 (chest wall metastasis); HIM 8 (chest wall metastasis); HIM9 (chest wall metastasis). Passage 3 HIM tumors serially transplanted in NOD/SCID mice have similar histopathological features to their original human counterparts (HCP). Sequence analyses of the eight HIM lines reveals mutations in the TP53 gene in three tumor lines and a mutation in PIK3CA gene in one tumor line that are also present in the HCP. aCGH analysis, where available, also demonstated that the positions of the major gene amplifications and deletions in HIM lines are also consistent with the HCP. Furthermore, aCGH shows that genomic structure of the grafts are stable with passage. Immunohistochemistry shows that HIM8 and its HCP are positive for HER2. Molecular subtyping by PAM50 gene list indicates that HIM 2 – 8 tumor lines and their HCP are basal type breast cancer. HIM9 tumor line and its HCP are luminal subtypes, although the proliferation signature was activated in the mouse graft.
 Conclusions: The HIM mouse system faithfully reproduces the genotypic features of the respective HCP's and is therefore a valuable research engine for the preclinical development of biomarkers, imaging techniques and for the assessment of novel therapeutic approaches, particularly for Basal-type breast cancer.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 41.

133 EFFECTS OF FROZEN STORED CULTURE MEDIA ON PRE-IMPLANTATION DEVELOPMENT OF PARTHENOTES AND CLONED EMBRYOS IN PIGS

The present study was designed to examine if frozen storage of porcine zygote medium (PZM3) plus 3 mg mL–1 BSA (Yoshioka et al. 2002 Bio. Reprod. 66, 112–119) is feasible to culture pig embryos produced by parthenogenetic activation and somatic nuclear transfer. Slaughterhouse-derived sow cumulus–oocyte complexes (COCs) were matured in TCM199 supplemented with 10% porcine follicle fluid, 5% cattle serum, 10 IU mL–1 eCG, 5 IU mL–1 hCG, 0.8 mm L-glutamine and 0.05 mg mL–1 gentamicin at 38.5°C, 100% humidity and 5% CO2 in air. For activation, cumulus cells were removed after 42 to 44 h of maturation, and the denuded oocytes with 1st polar body were activated with a double 160 V mm–1, 100 μs direct pulse followed by culture in PZM3. Each experiment was replicated at least three times. Data were expressed as mean ± SEM and analyzed by using chi-square module in SPSS 11.0, with P < 0.05 denoting significant difference. In Experiment 1, after preparation, liquid PZM3 was aliquoted to 50 mL falcon centrifuge tubes. Randomly, half of the tubes with PZM3 were put into –80°C freezers, and the rest were placed into 4°C refrigerator. Within one week after storage, a tube of frozen PZM3, while that stored at 4°C served as control, was warmed at 38.5°C in CO2 incubator, and more than three 4-well culture dishes were then made with 400 μL PZM3 in each well and balanced for at least 4 h in the incubator before experiment. The results showed that both cleavage (78/93, 83.9 ± 1.2% v. 87/103, 84.5 ± 1.8%, P > 0.05) and blastocyst (60/93, 65.2 ± 2.1% v. 65/103, 63.1 ± 3.8%, P > 0.05) rates were similar between frozen-warmed PZM3 and control, as was total cell numbers per blastocyst (50 ± 7 v. 47 ± 5, P > 0.05) between groups. In Experiment 2, we used somatic cloned embryos to investigate the effect of frozen-warmed PZM3 on pre-implantation development of such embryos. Our results indicated that no significant difference in rates of cleavage (68/95, 71.5 ± 5.1% v. 78/100, 78.1 ± 1.9%, P > 0.05), blastocyst formation (33/95, 34.6 ± 7.6% v. 78/100, 38.2 ± 3.5%, P > 0.05) and total cell numbers per blastocyst (40 ± 11 v. 48 ± 9, P > 0.05) was found between the test and control groups, designed the same as in Experiment 1. In Experiment 3, we tested whether PZM3 in frozen storage for 5 months was able to support in vitro development of parthenotes comparable to freshly-made ones. PZM3 after frozen storage for 5 months was warmed using the same method as Experiment 1, and the newly made PZM3 within 1 week of storage at 4°C acted as control. The results showed that although the cleavage (135/138, 97.8 ± 2.7% v. 117/129, 90.7 ± 3.1%, P > 0.05) and blastocyst (104/138, 75.4 ± 1.6% v. 84/129, 65.1 ± 2.3, P > 0.05) rates in control group were both slightly higher than that in the test group, no statistical differences was observed. We also found no significant difference in total cell numbers per blastocyst (48 ± 7 v. 46 ± 6, P > 0.05) between groups. Taken together, our results imply that frozen storage of PZM3 is feasible, and of practical value for culture pig embryos.

Light flux density threshold at which protein denaturation is induced by synchrotron radiation circular dichroism beamlines

New high-flux synchrotron radiation circular dichroism (SRCD) beamlines are providing important information for structural biology, but can potentially cause denaturation of the protein samples under investigation. This effect has been studied at the new CD1 dedicated SRCD beamline at ISA in Denmark, where radiation-induced thermal damage effects were observed, depending not only on the radiation flux but also on the focal spot size of the light. Comparisons with similar studies at other SRCD facilities worldwide has lead to the estimation of a flux density threshold under which SRCD beamlines should be operated when samples are to be exposed to low-wavelength vacuum ultraviolet radiation for extended periods of time.

Long-term cognitive functions in neonatal short bowel syndrome patients

OBJECTIVE

The aim of the study was to evaluate the long-term effects of neonatal short bowel syndrome on cognitive functions during development.

SUBJECTS AND METHODS

Nine patients diagnosed with short bowel syndrome during the neonatal period were enrolled in this study. Their medical records were reviewed; anthropometric measurements and blood tests were assayed; IQ tests (the Chinese versions of WAIS-R, WPPSI-R and WISC-R) were performed depending on their age, and a BSID assessment was carried out in those patients less than 4 years old.

RESULTS

Eight of 9 patients were followed up except for one patient who died in a car accident at the age of three. All patients had been weaned off parenteral nutrition for more than 2 years. The average residual small bowel length was 58.1 cm (range 35-70 cm), and the mean parenteral nutrition (PN) duration was 73.1 days (43-147 days). The mean duration of the period without PN was 7.4 years (range 2.1-17.1 years). Weight, height and BMI for age were normal in 7 children except for 1 child, who was overweight. Hemoglobin and albumin concentrations were normal in all 8 patients. Evaluation of cognitive development showed normal results for all 8 patients while a verbal/performance discrepancy was found in 2.

CONCLUSION

Patients with neonatal SBS who were weaned off PN for more than 2 years were found to have normal growth and cognitive development during this long-term follow-up. There was no evidence for a strong correlation between SBS and nutritional/cognition disorder. Longer term and controlled studies with a larger sample size are warranted.

Enhancement of radiation response by inhibition of Aurora-A kinase using siRNA or a selective Aurora kinase inhibitor PHA680632 in p53-deficient cancer cells

Overexpression of Aurora-A kinase has been correlated with cancer susceptibility and poor prognosis in several human cancers. In this study, we evaluated the effect of inhibition of Aurora-A kinase on cell cycle progression and tumour cell survival after exposure to ionising radiation (IR). Combined IR and Aurora-A inhibition by short interfering RNA (siRNA) or by PHA680632 (a selective Aurora kinase inhibitor with submicromolar activity against Aurora-A) prior to IR led to an enhancement of radiation-induced annexin V positive cells, micronuclei formation, and Brca1 foci formation only in cells with deficient p53. However, the drug brought about additive to sub-additive interaction with radiation with regard to in vitro clonogenic survival. Cell cycle analysis revealed a high >4N DNA content 24 h after PHA680632 exposure. DNA content >4N was reduced dramatically when cells were irradiated combined with PHA680632 simultaneously. In vivo xenografts (p53−/− HCT116) of a mice study showed enhanced tumour growth delay (TGD) after the PHA680632−IR combinatorial treatment compared with IR alone. These results demonstrate that PHA680632 in association with radiation leads to an additive effect in cancer cells, especially in the p53-deficient cells, but does not act as a radiosensitiser in vitro or in vivo.

The OrthoChina project

Online case discussion may be used for the education of orthopaedic surgeons. The authors developed a website for discussing orthopaedic cases nine years ago and describe its management. It currently has 20,000 registered users.

VEGF receptor inhibition slows the progression of polycystic kidney disease

Although the receptors for vascular endothelial growth factor (VEGF) exert their effects on vasculogenesis and angiogenesis through receptors located on endothelial cells, recent studies have shown that these receptors are also present on renal tubular epithelial cells. We investigated the role of VEGF on increased tubule cell proliferation in the Han:SPRD heterozygous (Cy/+) rat model of polycystic kidney disease. The levels of VEGF in the kidneys and the serum, and the expression of the two receptors on tubules were increased in Cy/+ rats. These rats were given ribozymes that specifically inhibited VEGFR1 and VEGFR2 mRNA expression. Tubule cell proliferation within the cysts was significantly decreased in the ribozyme-treated animals leading to decreased cystogenesis, blunted renal enlargement, and prevented the loss of renal function. Our studies show that inhibition of VEGF function may be an important therapeutic option to delay the progression of polycystic kidney disease.

Genetic relationships among Chinese pigs and other pig populations from Hunan Province, China

In this study, protein-level polymorphisms of transferrin, pre-albumin, hemopexin, ceruloplasmin and amylase were investigated in Hunan native pigs and Large Yorkshire pigs collected from Hunan (a province of China), allowing calculations of allele frequencies, average heterozygosities, inbreeding coefficients and genetic distances. The genetic relationship between Southeast Asian native pigs and American pigs was more distant than those among Southeast Asian native pig breeds. The genetic relationship between Southeast Asian native pig breeds and Hampshire pigs was the most distant.

Cell-cycle complete response after neoadjuvant letrozole predicts superior relapse-free and overall survival: Long-term follow- up of the letrozole P024 study

570

Background: The P024 study was a double blind randomized endocrine therapy trial that compared 16 weeks of letrozole 2.5 mg daily (LET) with tamoxifen 20 mg daily (TAM). LET proved to be more effective than TAM in terms of tumor response and rates of breast conservation therapy (1). Biomarker studies also indicated that LET was a more effective anti-proliferative agent, with greater declines in Ki67 values (2). However, in the P024 trial patients experienced a very low rate of pathological complete response (pCR). We have therefore proposed that a cell-cycle complete response (CCCR - in which tumor cell Ki67 staining is 1% or less in the surgical specimen) may be an alternative to pCR because CCCR indicates that the endocrine therapy was maximally effective in causing cell-cycle arrest. In initial studies we had already shown that CCCR is more common with LET than TAM (3), and also there was a strong association between the absence of a CCCR and the presence of HER2 gene amplification (4). In this study we examined the relationships between CCCR and relapse-free and overall survival. Methods: Per protocol, patients were followed yearly for breast cancer relapse, all cause mortality and breast cancer specific mortality. Relapse-free and breast cancer specific survival was examined according to CCCR status after patients had been followed for five years on adjuvant TAM. Results: Patients who received neoadjuvant LET and whose tumors exhibited a CCCR had superior relapse-free (log rank P=0.0077) and breast cancer specific survival (P=0.0006). Patients who received TAM with a CCCR had superior RFS (P=0.0224) but not breast cancer specific survival. Conclusions: This study supports the conclusion that CCCR may be a clinically useful measurement for patients who undergo neoadjuvant LET. The value of CCCR after neoadjuvant TAM is less clear. A prospective trial that incorporates information on CCCR into clinical decision making regarding adjuvant chemotherapy may be appropriate. 1. Ann Oncol 12, 1527–32 (2001) 2. Cancer Res 63, 6523–31 (2003). 3. J Steroid Biochem Mol Biol 95, 91–5 (2005). 4. J Clin Oncol 24, 3019–25 (2006).

No significant financial relationships to disclose.

Mass-limited Sn target irradiated by dual laser pulses for an extreme ultraviolet lithography source

A thin Sn film was investigated as a mass-limited target for an extreme ultraviolet (EUV) lithography source. It was found that those energetic ions that are intrinsic with the mass-limited Sn target could be efficiently mitigated by introducing a low-energy prepulse. High in-band conversion efficiency from a laser to 13.5 nm EUV light could be obtained using an Sn film with a thickness down to 30 nm when irradiated by dual laser pulses. It was shown that the combination of dual pulse and inert Ar gas could fully mitigate ions with a low ambient pressure nearly without the penalty of the absorption of the EUV light.