bluuebunny/crossref_metadata_2025 huggingface dataset:
Co-synergism of endophyte Penicillium resedanum LK6 with salicylic acid helped Capsicum annuumin biomass recovery and osmotic stress mitigation
Authors: Khan Abdul Latif , Waqas Muhammad , Hamayun Muhammad , Al-Harrasi Ahmed , Al-Rawahi Ahmed , Lee In-Jung
Published: March 2013

Background

Water-deficiency adversely affects crop growth by generating reactive oxygen species (ROS) at cellular level. To mitigate such stressful events, it was aimed to investigate the co-synergism of exogenous salicylic acid (SA) and symbiosis of endophytic fungus with Capsicum annuum L. (pepper).

Results

The findings of the study showed that exogenous SA (10-6 M) application to endophyte (Penicillium resedanum LK6) infected plants not only increased the shoot length and chlorophyll content but also improved the biomass recovery of pepper plants under polyethylene glycol (15%) induced osmotic stress (2, 4 and 8 days). Endophyte-infected plants had low cellular injury and high photosynthesis rate. SA also enhanced the colonization rate of endophyte in the host-plant roots. Endophyte and SA, in combination, reduced the production of ROS by increasing the total polyphenol, reduce glutathione, catalase, peroxidase and polyphenol oxidase as compared to control plants. Osmotic stress pronounced the lipid peroxidation and superoxide anions formation in control plants as compared to endophyte and SA-treated plants. The endogenous SA contents were significantly higher in pepper plants treated with endophyte and SA under osmotic stress as compared to control.

Conclusion

Endophytic fungal symbiosis and exogenous SA application can help the plants to relieve the adverse effects of osmotic stress by decreasing losses in biomass as compared to non-inoculated plants. These findings suggest that SA application positively impact microbial colonization while in combination, it reprograms the plant growth under various intervals of drought stress. Such symbiotic strategy can be useful for expanding agriculture production in drought prone lands.
MLPA-based genotype–phenotype analysis in 1053 Chinese patients with DMD/BMD
Authors: Yang Juan , Li Shao Y , Li Ya Q , Cao Ji Q , Feng Shan W , Wang Yan Y , Zhan Yi X , Yu Chang S , Chen Fei , Li Jing , Sun Xiao F , Zhang Cheng
Published: March 2013

Background

Large-scale analysis of the transmission, mutation characteristics and the relationship between the reading frame and phenotype of the DMD gene has previously been performed in several countries, however, analogous studies have yet to be performed in Chinese populations.

Methods

Clinical data from 1053 Chinese patients with DMD/BMD were collected, and the DMD gene was tested by MLPA in all patients and 400 proband mothers. In 20 patients with negative MLPA, sequencing was also performed.

Results

We found that 27.50% of cases had a family medical history of DMD/BMD, and large rearrangements were identified in 70.56% of the probands, of which 59.35% and 11.21% were deletions or duplications, respectively. The carrier status of the mothers in the study was determined to be 50.75%, and it was established that the DMD mutation was inherited from the mother in 51.72% of the probands. Exons 45–54 and 3–22 were the most frequently deleted regions, and exons 3–11 and 21–37 were the most prevalently duplicated regions of the gene. Breakpoints mainly occurred in introns 43–55 for deletion mutations and in introns 2 and 7 for duplication mutations. No breakpoints were found at the 5′ or 3′ end of introns 31, 35, 36, 40, 65, 68, and 74–78 in any of the deletion or duplication mutations. The reading frame rule held true for 86.4% of the DMD patients and 74.55% of the BMD patients.

Conclusion

It is essential to increase physicians’ understanding of DMD/BMD, to promote scientific information, and to increase awareness in regards to genetic counseling and prenatal diagnosis in pedigrees with a family history of the disease, particularly in families with small DMD lesions in China. In addition, such a large-scale analysis will prove to be instructive for leading translational studies between basic science and clinical medicine.
Combination of a GnRH agonist with an antagonist prevents flare-up effects and protects primordial ovarian follicles in the rat ovary from cisplatin-induced toxicity: a controlled experimental animal study
Authors: Li Xiaoyan , Kang Xiang , Deng Qingchun , Cai Jing , Wang Zehua
Published: March 2013

Background

With the continuous improvement of surgery and chemotherapeutic treatments, many tumour patients increasingly achieve long-term survival and can even be completely cured. However, platinum-containing drugs, which are widely used to treat a variety of types of cancer, cause menstrual disorders and ovarian failure, which in turn lead to infertility. Thus far, gonadotropin releasing hormone (GnRH) agonist (GnRHa) and antagonist (GnRHant) are reported to act as protective agents of the ovary in chemotherapy through the inhibition of the female gonadal axis. Nevertheless, they both have disadvantages that limit their use. GnRHa causes a flare-up effect during the first week after administration, and no long-acting GnRHant agent is available. GnRHa combined with GnRHant may prevent the flare-up effect of GnRHa and rapidly inhibit the female gonadal axis. Several clinical studies with small sample sizes have reported controversial conclusions. In this strictly controlled animal study, we investigated the advantages of combination treatment with GnRHa and GnRHant.

Methods

Rats aged 12 weeks were divided into six groups: Control, cisplatin (CDDP), GnRHa, GnRHant, Combination (sht, short-term) and Combination (lng, long-term) of GnRHa and GnRHant. The last four groups received Triptorelin (1 mg/kg·d, for 14 days), Cetrorelix (0.5 mg/kg·d, for 10 days), a combination of Triptorelin (1 mg/kg·d, for 10 days) and Cetrorelix (0.5 mg/kg·d, for 10 days) in the long-term group and for 3 days in the short-term group. The Control and CDDP groups received saline (1 ml/kg·d, for 10 day). Then, all groups apart from the Control group received cisplatin (1 mg/kg·d, for 10 days), and the Control group received another 10 days of saline as described above. Blood samples were collected to detect the serum levels of E2, LH and FSH. Observation of oestrous cyclicity was also performed after drug administration. Finally, bilateral ovaries were collected for histological study and follicle counting.

Results

We observed a flare-up effect in rats treated with GnRHa, but not in any of the combination groups. The percentage of normal cyclicity increased from 0% in the CDDP group to 25.0%, 33.3%, 66.7% and 41.7%, in the GnRHa, GnRHant, combination (lng) and combination (sht) groups, respectively. Pretreatment with GnRHa, GnRHant and combination (lng) significantly protected the primordial follicles from destruction by preserving 57.6%, 63.4%, 87.1% and 60.4% of the follicles, respectively.

Conclusions

The combination of a GnRH agonist with antagonist completely prevented the flare-up effect and enhanced the protective effect of the ovary from cisplatin-induced gonadotoxicity in rats.
SSX2IP promotes metastasis and chemotherapeutic resistance of hepatocellular carcinoma
Authors: Li Pu , Lin Ying , Zhang Yu , Zhu Zhenggang , Huo Keke
Published: March 2013

Background

Synovial sarcoma, X breakpoint 2 interacting protein (SSX2IP), which has been identified as an acute myeloid leukemia associated antigen, is a potential target for leukemia immunotherapy. In rodents, its homologous gene, ADIP, plays an important role in the regulation of cell adhesion and migration, underlying its potential role in promoting metastasis of other cancers.

Methods

To investigate the correlation between the expression level of SSX2IP and the clinicopathologic factors of hepatocellular carcinoma (HCC), 53 cases were studied by qPCR and statisted. To directly testing SSX2IP’s contribution to HCC in animal models, 45 nude mice were enrolled in peritoneal spreading and liver metastasis models. For the migration and invasion assays, cell culture experiments were performed using QCMTM24-Well Colorimetric Migration Assay Kit and Cell Invasion Assay Kit (Millipore). Moreover we examined the influence of SSX2IP overexpression on the chemosensitivity of hepatocellular carcinoma cells to two most common chemotherapy drugs (5-Fu and CDDP) using Cell counting kit-8 (CCK-8). The chemotherapeutic drugs sensitivity was evaluated by IC50 parameter.

Results

Statistical analysis of clinical cases revealed that the SSX2IP high expression group had inclinations towards larger tumor size, more tumor thrombus and shorter survival period, implying a strong correlation between the expression level of SSX2IP and HCC tumorigenesis. Consistently in abdominal cavity metastasis and liver metastasis models of immune-deficient mice, SSX2IP was able to promote the metastasis of hepatoma cells. At the cytological level, SSX2IP stimulates the wound healing, metastasis and invasion of hepatoma cells, and reduces the sensitivity of hepatoma cells to 5-Fu and CDDP.

Conclusions

Our results showed that SSX2IP promotes the development and metastasis of hepatocellular carcinoma and contributes to the drug resistance of hepatoma cells, suggesting that SSX2IP is expected to become a new diagnostic and prognostic marker and a new target of the treatment of hepatocellular carcinoma.
Coherent magnetic semiconductor nanodot arrays
Authors: Wang Yong , Xiu Faxian , Wang Ya , Zou Jin , Beyermann Ward P , Zhou Yi , Wang Kang L
Published: March 2013

In searching appropriate candidates of magnetic semiconductors compatible with mainstream Si technology for future spintronic devices, extensive attention has been focused on Mn-doped Ge magnetic semiconductors. Up to now, lack of reliable methods to obtain high-quality MnGe nanostructures with a desired shape and a good controllability has been a barrier to make these materials practically applicable for spintronic devices. Here, we report, for the first time, an innovative growth approach to produce self-assembled and coherent magnetic MnGe nanodot arrays with an excellent reproducibility. Magnetotransport experiments reveal that the nanodot arrays possess giant magneto-resistance associated with geometrical effects. The discovery of the MnGe nanodot arrays paves the way towards next-generation high-density magnetic memories and spintronic devices with low-power dissipation.
Phononic and magnonic dispersions of surface waves on a permalloy/BARC nanostructured array
Authors: Pan Huihui , Zhang Vanessa Li , Di Kai , Kuok Meng Hau , Lim Hock Siah , Ng Ser Choon , Singh Navab , Adeyeye Adekunle Olusola
Published: March 2013

Phononic and magnonic dispersions of a linear array of periodic alternating Ni80Fe20 and bottom anti-reflective coating nanostripes on a Si substrate have been measured using Brillouin light scattering. The observed phononic gaps are considerably larger than those of laterally patterned multi-component crystals previously reported, mainly a consequence of the high elastic and density contrasts between the stripe materials. Additionally, the phonon hybridization bandgap has an unusual origin in the hybridization and avoided crossing of the zone-folded Rayleigh and pseudo-Sezawa waves. The magnonic band structure features near-dispersionless branches, with unusual vortex-like dynamic magnetization profiles, some of which lie below the highly-dispersive fundamental mode branch. Finite element calculations of the phononic and magnonic dispersions of the magphonic crystal accord well with experimental data.
Modulation in current density of metal/n-SiC contact by inserting Al2O3 interfacial layer
Authors: Zheng Shan , Sun Qing-Qing , Yang Wen , Zhou Peng , Lu Hong-Liang , Zhang David Wei
Published: March 2013

Metal contact to SiC is not easy to modulate since the contact can be influenced by the metal, the termination of the SiC, the doping, and the fabrication process. In this work, we introduce a method by inserting a thin Al2O3 layer between metal and SiC to solve this problem simply but effectively. The Al2O3/n-SiC interface composition was obtained with X-ray photoemission spectroscopy, and the electrical properties of subsequently deposited metal contacts were characterized by current–voltage method. We can clearly demonstrate that the insertion of Al2O3 interfacial layer can modulate the current density effectively and realize the transfer between the Schottky contact and ohmic contact.
Urysohn integral equations approach by common fixed points in complex-valued metric spaces
Authors: Sintunavarat Wutiphol , Cho Yeol Je , Kumam Poom
Published: March 2013

Recently, the complex-valued metric spaces which are more general than the metric spaces were first introduced by Azamet al.(Numer. Funct. Anal. Optim. 32:243-253, 2011). They also established the existence of fixed point theorems under the contraction condition in these spaces. The aim of this paper is to introduce the concepts of aC-Cauchy sequence andC-complete in complex-valued metric spaces and establish the existence of common fixed point theorems inC-complete complex-valued metric spaces. Furthermore, we apply our result to obtain the existence theorem for a common solution of the Urysohn integral equations

x(t)=∫abK1(t,s,x(s))ds+g(t),x(t)=∫abK2(t,s,x(s))ds+h(t),

wheret∈[a,b]⊆R,x,g,h∈C([a,b],Rn)andK1,K2:[a,b]×[a,b]×Rn→Rn.

MSC:47H09, 47H10.
Molecular basis for prey relocation in viperid snakes
Authors: Saviola Anthony J , Chiszar David , Busch Chardelle , Mackessy Stephen P
Published: March 2013

Background

Vertebrate predators use a broad arsenal of behaviors and weaponry for overcoming fractious and potentially dangerous prey. A unique array of predatory strategies occur among snakes, ranging from mechanical modes of constriction and jaw-holding in non-venomous snakes, to a chemical means, venom, for quickly dispatching prey. However, even among venomous snakes, different prey handling strategies are utilized, varying from the strike-and-hold behaviors exhibited by highly toxic elapid snakes to the rapid strike-and-release envenomation seen in viperid snakes. For vipers, this mode of envenomation represents a minimal risk predatory strategy by permitting little contact with or retaliation from prey, but it adds the additional task of relocating envenomated prey which has wandered from the attack site. This task is further confounded by trails of other unstruck conspecific or heterospecific prey. Despite decades of behavioral study, researchers still do not know the molecular mechanism which allows for prey relocation.

Results

During behavioral discrimination trials (vomeronasal responsiveness) to euthanized mice injected with size-fractionated venom, Crotalus atrox responded significantly to only one protein peak. Assays for enzymes common in rattlesnake venoms, such as exonuclease, L-amino acid oxidase, metalloproteinase, thrombin-like and kallikrein-like serine proteases and phospholipase A2, showed that vomeronasal responsiveness was not dependent on enzymatic activity. Using mass spectrometry and N-terminal sequencing, we identified the proteins responsible for envenomated prey discrimination as the non-enzymatic disintegrins crotatroxin 1 and 2. Our results demonstrate a novel and critical biological role for venom disintegrins far beyond their well-established role in disruption of cell-cell and cell-extracellular matrix interactions.

Conclusions

These findings reveal the evolutionary significance of free disintegrins in venoms as the molecular mechanism in vipers allowing for effective relocation of envenomated prey. The presence of free disintegrins in turn has led to evolution of a major behavioral adaptation (strike-and-release), characteristic of only rattlesnakes and other vipers, which exploits and refines the efficiency of a pre-existing chemical means of predation and a highly sensitive olfaction system. This system of a predator chemically tagging prey represents a novel trend in the coevolution of predator-prey relationships.
TNF-α promotes cerebral pericyte remodeling in vitro, via a switch from α1 to α2 integrins
Authors: Tigges Ulrich , Boroujerdi Amin , Welser-Alves Jennifer V , Milner Richard
Published: March 2013

Background

There is increasing evidence to suggest that pericytes play a crucial role in regulating the remodeling state of blood vessels. As cerebral pericytes are embedded within the extracellular matrix (ECM) of the vascular basal lamina, it is important to understand how individual ECM components influence pericyte remodeling behavior, and how cytokines regulate these events.

Methods

The influence of different vascular ECM substrates on cerebral pericyte behavior was examined in assays of cell adhesion, migration, and proliferation. Pericyte expression of integrin receptors was examined by flow cytometry. The influence of cytokines on pericyte functions and integrin expression was also examined, and the role of specific integrins in mediating these effects was defined by function-blocking antibodies. Expression of pericyte integrins within remodeling cerebral blood vessels was analyzed using dual immunofluorescence (IF) of brain sections derived from the animal model of multiple sclerosis, experimental autoimmune encephalomyelitis (EAE).

Results

Fibronectin and collagen I promoted pericyte proliferation and migration, but heparan sulfate proteoglycan (HSPG) had an inhibitory influence on pericyte behavior. Flow cytometry showed that cerebral pericytes express high levels of α5 integrin, and lower levels of α1, α2, and α6 integrins. The pro-inflammatory cytokine tumor necrosis factor (TNF)-α strongly promoted pericyte proliferation and migration, and concomitantly induced a switch in pericyte integrins, from α1 to α2 integrin, the opposite to the switch seen when pericytes differentiated. Inhibition studies showed that α2 integrin mediates pericyte adhesion to collagens, and significantly, function blockade of α2 integrin abrogated the pro-modeling influence of TNF-α. Dual-IF on brain tissue with the pericyte marker NG2 showed that while α1 integrin was expressed by pericytes in both stable and remodeling vessels, pericyte expression of α2 integrin was strongly induced in remodeling vessels in EAE brain.

Conclusions

Our results suggest a model in which ECM constituents exert an important influence on pericyte remodeling status. In this model, HSPG restricts pericyte remodeling in stable vessels, but during inflammation, TNF-α triggers a switch in pericyte integrins from α1 to α2, thereby stimulating pericyte proliferation and migration on collagen. These results thus define a fundamental molecular mechanism in which TNF-α stimulates pericyte remodeling in an α2 integrin-dependent manner.
Carcinoembryonic antigen (CEA) level, CEA ratio, and treatment outcome of rectal cancer patients receiving pre-operative chemoradiation and surgery
Authors: Yang Kai-Lin , Yang Shung-Haur , Liang Wen-Yih , Kuo Ying-Ju , Lin Jen-Kou , Lin Tzu-Chen , Chen Wei-Shone , Jiang Jeng-Kae , Wang Huann-Sheng , Chang Shih-Ching , Chu Lee-Shing , Wang Ling-Wei
Published: March 2013

Background

To investigate serum carcinoembryonic antigen (CEA) as a prognostic factor for rectal cancer patients receiving pre-operative chemoradiotherapy (CRT).

Methods

Between 2000 and 2009, 138 patients with advanced rectal cancer receiving CRT before surgery at our hospital were retrospectively classified into 3 groups: pre-CRT CEA <6 ng/ml (group L; n = 87); pre-CRT CEA ≥ 6 ng/ml and post-CRT CEA <6 ng/ml (group H-L; n = 32); and both pre- and post-CRT CEA ≥ 6 ng/ml (group H-H; n = 19). CEA ratio (defined as post-CRT CEA divided by pre-CRT CEA), post-CRT CEA level and other factors were reviewed for prediction of pathologic complete response (pCR).

Results

Five-year disease-free survival (DFS) was better in groups L (69.0%) and H-L (74.5%) than in group H-H (44.9%) (p = 0.024). Pathologic complete response was observed in 19.5%, 21.9% and 5.3% of groups L, H-L and H-H respectively (p = 0.281). Multivariate analysis showed that ypN stage and pCR were independent prognostic factors for DFS and that post-CRT CEA level was independently predictive of pCR. As a whole, post-CRT CEA <2.61 ng/ml predicted pCR (sensitivity 76.0%; specificity 58.4%). For those with pre-CRT CEA ≥6 ng/ml, post-CRT CEA and CEA ratio both predicted pCR (sensitivity 87.5%, specificity 76.7%).

Conclusions

In patients with pre-CRT serum CEA ≥6 ng/ml, those with “normalized” CEA levels after CRT may have similar DFS to those with “normal” (<6 ng/ml) pre-CRT values. Post-CRT CEA level is a predictor for pCR, especially in those with pre-CRT CEA ≥6 ng/ml.
Chemical fingerprinting and quantitative constituent analysis of Siwu decoction categorized formulae by UPLC-QTOF/MS/MS and HPLC-DAD
Authors: Su Shulan , Cui Wenxia , Zhou Wei , Duan Jin-ao , Shang Erxin , Tang Yuping
Published: March 2013

Background

Siwu decoction categorized formulae (SWDCF) are widely used for treating gynecological diseases. This study aims to elucidate the differences of bioactive constituents in SWDCF by ultra-high performance liquid chromatography coupled with time-of-flight mass spectrometry (UPLC - QTOF - MS /MS) and HPLC-DAD.

Methods

An efficient method based on UPLC - QTOF - MS /MS was developed for identifying the chemical profiles of SWDCF. HPLC-DAD method was used for quantifying seven chemical markers in SWDCF.

Results

Eighty four components were identified or characterized, including ten organic acids, thirty glycosides (monoterpene or iridoid or phenylpropanoids glycosides), fourteen lactones, eighteen flavonoids, and eleven alkaloids in the complex system. The datasets of tR-m/z pairs, ion intensities and sample codes were processed with supervised orthogonal partial least squared discriminant analysis to compare these decoction samples. After a clear classification was established, OPLS-DA was performed and 16 common components with relative quantity in SWDCF samples were determined. Gallic acid, protocatechuic acid, vanillic acid, caffeic acid, paeoniflorin, ferulic acid, and senkyunolide I were selected as the chemical markers to identify SWDCF by HPLC-DAD.

Conclusion

The chemical profiles with 84 components in SWDCF, including monoterpene glycosides, acetophenones, galloyl glucoses, even some isomers in the complex system were characterized by UPLC–QTOF–MS/MS.
Metabolic fingerprinting of Angelica sinensisduring growth using UPLC-TOFMS and chemometrics data analysis
Authors: Qian Yiyun , Wang Yali , Sa Rina , Yan Hui , Pan Xinbo , Yang Yingwen , Sun Yujing
Published: March 2013

Background

The radix of Angelica sinensis is widely used as a medicinal herbal and metabolomics research of this plant during growth is necessary.

Results

Principal component analysis of the UPLC-QTOFMS data showed that these 27 samples could be separated into 4 different groups. The chemical markers accounting for these separations were identified from the PCA loadings plot. These markers were further verified by accurate mass tandem mass and retention times of available reference standards. The study has shown that accumulation of secondary metabolites of Angelica sinensis is closely related to the growth periods.

Conclusions

The UPLC-QTOFMS based metabolomics approach has great potential for analysis of the alterations of secondary metabolites of Angelica sinensis during growth.
The multiple roles of histidine in protein interactions
Authors: Liao Si-Ming , Du Qi-Shi , Meng Jian-Zong , Pang Zong-Wen , Huang Ri-Bo
Published: March 2013

Background

Among the 20 natural amino acids histidine is the most active and versatile member that plays the multiple roles in protein interactions, often the key residue in enzyme catalytic reactions. A theoretical and comprehensive study on the structural features and interaction properties of histidine is certainly helpful.

Results

Four interaction types of histidine are quantitatively calculated, including: (1) Cation-π interactions, in which the histidine acts as the aromatic π-motif in neutral form (His), or plays the cation role in protonated form (His+); (2) π-π stacking interactions between histidine and other aromatic amino acids; (3) Hydrogen-π interactions between histidine and other aromatic amino acids; (4) Coordinate interactions between histidine and metallic cations. The energies of π-π stacking interactions and hydrogen-π interactions are calculated using CCSD/6-31+G(d,p). The energies of cation-π interactions and coordinate interactions are calculated using B3LYP/6-31+G(d,p) method and adjusted by empirical method for dispersion energy.

Conclusions

The coordinate interactions between histidine and metallic cations are the strongest one acting in broad range, followed by the cation-π, hydrogen-π, and π-π stacking interactions. When the histidine is in neutral form, the cation-π interactions are attractive; when it is protonated (His+), the interactions turn to repulsive. The two protonation forms (and pKavalues) of histidine are reversibly switched by the attractive and repulsive cation-π interactions. In proteins the π-π stacking interaction between neutral histidine and aromatic amino acids (Phe, Tyr, Trp) are in the range from -3.0 to -4.0 kcal/mol, significantly larger than the van der Waals energies.
Mesothelin regulates growth and apoptosis in pancreatic cancer cells through p53-dependent and -independent signal pathway
Authors: Zheng Chunning , Jia Wei , Tang Yong , Zhao HuiLiang , Jiang Yingsheng , Sun Shaochuan
Published: March 2013

Mesothelin, a secreted protein, is overexpressed in some cancers, including pancreatic cancer. Rescent studies have shown that overexpression of mesothelin significantly increased tumor cell proliferation, and downregulation of mesothelin inhibited cell proliferation in pancreatic cancer cells, but its exact function and mechanism remains unclear. The aim of the present study was to evaluate the effects of mesothelin on proliferation and apoptosis in pancreatic cancer cells with different p53 status and to explore its signal pathway. Mesothelin levels were detected by western blot and RT-PCR assay in human pancreatic cancer AsPC-1, HPAC and Capan-2, Capan-1 and MIA PaCa-2 cell lines. Mesothelin was slienced by shRNA in AsPC-1, Capan-2 and Capan-1 cells with rich mesothelin level, and mesothelin was overexpressed in the HPAC and Capan-2 cells with less mesothelin level. We observed that in the AsPC-1 and Capan-1cells with mt-p53, and Capan-2 cells with wt-p53, shRNA mediated sliencing of the mesothelin significantly increased PUMA and Bax expression and caspase-3 activity, and decreased bcl-2 expression, followed by the reduced proliferation and colony forming capability and increased cell apoptosis. When PUMA was slienced by siRNA in the stable mesothelin shRNA transfected cells, proliferative capability was significantly increased, and apoptosis was decreased. However, in the Capan-2 cells with wt-p53, suppression of the mesothelin significantly increased wt-p53 levels. When p53 was blocked by siRNA in the stable mesothelin shRNA transfected Capan-2 cells, PUMA was inhibited, followed by increased proliferative capability and decreased cell apoptosis. In the HPAC and Capan-2 cells with wt-p53 and in the MIA PaCa-2 cells with mt-p53, overexpression of the mesothelin significantly decreased bax levels and increased bcl-2 levels, followed by increased proliferative and colony forming capability. Furthermore, mesothelin-shRNA-transfected cells exhibited a reduced rate of tumor growth under in vivo conditions. However, mesothelin-transfected cells exhibited a increased rate of tumor growth under in vivo conditions. Our data demonstrated that mesothelin promotes proliferation and inhibited apoptosis through p53-dependent pathway in pancreatic cancer cells with wt-p53, and p53-independent pathway in pancreatic cancer cells with mt-p53. Targeting mesothelin by shRNA is the important method for pancreatic cancer therapy.
Prognostic value and functional consequences of cell cycle inhibitor p27Kip1 loss in medulloblastoma
Authors: Hatton Beryl A , Ellison David W , Gajjar Amar , Kool Marcel , Fero Matthew , Olson James M
Published: March 2013

Background

The cyclin-dependent kinase inhibitor p27Kip1 functions during normal cerebellar development and has demonstrated tumor suppressor functions in mouse models of medulloblastoma. Because P27 loss is associated with increased proliferation, we assessed whether P27 absence in surgical medulloblastoma specimens correlated with response to therapy in pediatric patients enrolled in two large studies. Additionally, we examined the functional consequence of p27

Kip1
loss in the SmoA1 medulloblastoma model to distinguish whether p27Kip1 reduces tumor initiation or slows tumor progression.

Findings

Analysis of 87 well-characterized patient samples identified a threshold of P27 staining at which significant P27 loss correlated with poor patient outcome. The same criteria, applied to a second test set of tissues from 141 patients showed no difference in survival between patients with minimal P27 staining and others, suggesting that P27 levels alone are not a sufficient prognostic indicator for identifying standard-risk patients that may fail standard therapy. These findings were in contrast to prior experiments completed using a mouse medulloblastoma model. Analysis of cerebellar tumor incidence in compound mutant mice carrying the activated Smoothened (SmoA1) allele that were heterozygous or nullizygous for p27

Kip1
revealed that p27Kip1 loss did not alter the frequency of tumor initiation. Tumors haploinsufficient or nullizygous for p27

Kip1
were, however, more invasive and displayed a higher proliferative index, suggesting p27Kip1 loss may contribute to SmoA1 medulloblastoma progression.

Conclusions

These studies revealed P27 loss affects medulloblastoma progression rather than initiation and that this putative biomarker should not be used for stratifying children with medulloblastoma to risk-based therapeutic regimens.
In vitro characterization of a chitosan skin regenerating template as a scaffold for cells cultivation
Authors: Mohd Hilmi Abu Bakar , Halim Ahmad Sukari , Hassan Asma , Lim Chin Keong , Noorsal Kartini , Zainol Ismail
Published: March 2013

Chitosan is a marine-derived product that has been widely used in clinical applications, especially in skin reconstruction. The mammalian scaffolds derived from bovine and porcine material have many limitations, for example, prion transmission and religious concerns. Therefore, we created a chitosan skin regenerating template (SRT) and investigated the behavior of fibroblast cell-scaffold constructs. Primary human dermal fibroblasts (HDF) were isolated and then characterized using vimentin and versican. HDF were seeded into chitosan SRT at a density of 3×106 cells/cm2 for fourteen days. Histological analysis and live cells imaging revealed that the cell-chitosan constructs within interconnected porous chitosan showed significant interaction between the cells as well as between the cells and the chitosan. Scanning electron microscopy (SEM) analysis revealed cells spreading and covering the pores. As the pore sizes of the chitosan SRT range between 40–140 μm, an average porosity is about 93 ± 12.57% and water uptake ratio of chitosan SRT is 536.02 ± 14.29%, it is a supportive template for fibroblast attachment and has potential in applications as a dermal substitute.
Phase III Randomized, Placebo-Controlled Trial of Docetaxel With or Without Gefitinib in Recurrent or Metastatic Head and Neck Cancer: An Eastern Cooperative Oncology Group Trial
Authors: Argiris Athanassios , Ghebremichael Musie , Gilbert Jill , Lee Ju-Whei , Sachidanandam Kamakshi , Kolesar Jill M. , Burtness Barbara , Forastiere Arlene A.
Published: March 2013

Purpose

We hypothesized that the addition of gefitinib, an epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor, to docetaxel would enhance therapeutic efficacy in squamous cell carcinoma of the head and neck (SCCHN).

Patients and Methods

Patients with recurrent or metastatic SCCHN with Eastern Cooperative Oncology Group (ECOG) performance status of 2, or patients with ECOG performance status of 0 to 2 but were previously treated with chemotherapy, were randomly assigned to receive weekly docetaxel plus either placebo (arm A) or gefitinib 250 mg/d, orally (arm B) until disease progression. At the time of progression, patients in the placebo arm could receive single-agent gefitinib. EGFR, c-MET, and KRAS mutations and polymorphisms in drug metabolizing enzymes and transporters were evaluated by pyrosequencing.

Results

Two hundred seventy patients were enrolled before the study was closed early at interim analysis (arm A, n = 136; arm B, n = 134). Median overall survival was 6.0 months in arm A versus 7.3 months in arm B (hazard ratio, 0.93; 95% CI, 0.72 to 1.21; P = .60). An unplanned subset analysis showed that gefitinib improved survival in patients younger than 65 years (median 7.6 v 5.2 months; P = .04). Also, there was a trend for improved survival in patients with c-MET wild-type (5.7 v 3.6 months; P = .09) regardless of treatment. Grade 3/4 toxicities were comparable between the two arms except that grade 3/4 diarrhea was more common with docetaxel/gefitinib. Of 18 eligible patients who received gefitinib after disease progression in arm A, one patient had a partial response.

Conclusion

The addition of gefitinib to docetaxel was well tolerated but did not improve outcomes in poor prognosis but otherwise unselected patients with SCCHN.
A Positive Regulatory Domain in CCAAT/Enhancer Binding Protein β (C/EBPβ) Is Required for the Glucocorticoid-Mediated Displacement of Histone Deacetylase 1 (HDAC1) from the C/ebpα Promoter and Maximum Adipogenesis
Authors: Abdou Houssein-Salem , Atlas Ella , Haché Robert J. G.
Published: March 2013

Glucocorticoids promote adipogenesis and contribute to the metabolic syndrome through a number of mechanisms. One of the effectors of glucocorticoid action is the CCAAT/enhancer binding protein β (C/EBPβ). C/EBPβ is a basic leucine-zipper transcription factor involved in diverse processes including differentiation, cellular proliferation, and inflammation. C/EBPβ transcriptional activity is regulated, in part, by its acetylation profile resulting from its dynamic interaction with either acetylases general control nonrepressed protein 5/p300/CBP associated factor (GCN5/PCAF) or deacetylase complexes (mSin3A/histone deacetylase 1 [HDAC1]). Glucocorticoid treatment of preadipocytes promotes C/EBPβ acetylation, leading to mSin3A/HDAC1 dissociation from C/EBPβ and resulting in C/ebpα promoter activation at the onset of adipogenesis, thus increasing the differentiation rate. We recently showed that the regulatory domain 1 (RD1) of C/EBPβ contains four residues (153–156) required for its interaction with HDAC1, therefore supporting RD1 proposed inhibitory role. In an attempt to further elucidate the intrinsic regulatory property of RD1, we sought to characterize the regulatory potential of the N terminus region of RD1 (residues 141–149). In this study, we show that C/EBPβΔ141–149 transcriptional activity was compromised on the C/ebpα, but not on the Pparγ, promoter. Additionally, the ability of C/EBPβΔ141–149 to induce adipogenesis in NIH 3T3 cells was compromised when compared with C/EBPβwt owing to a delayed expression of C/ebpα at the onset of differentiation. Furthermore, the data suggest that the reduced expression of C/ebpα in cells expressing C/EBPβΔ141–149 was due to a persistent recruitment of HDAC1 to the C/ebpα promoter after glucocorticoid treatment. Together, these results suggest that amino acids 141–149 of C/EBPβ act as a positive regulatory domain required for maximum transcriptional activity.
Facile Synthesis of Well-dispersed Hollow Mesoporous Silica Nanoparticles Using Iron Oxide Nanoparticles as Template
Authors: Ikuno Takaaki , Nomura Atsuro , Iyoki Kenta , Sugawara-Narutaki Ayae , Okubo Tatsuya , Shimojima Atsushi
Published: March 2013

A facile approach is demonstrated for the preparation of hollow mesoporous silica nanoparticles with large pore volume and high dispersibility. Core–shell nanoparticles consisting of iron oxide (α-Fe2O3) core and mesostructured silica–surfactant composite shell are treated with hexamethyldisiloxane under acidic conditions to achieve capping of silanol groups and removal of both surfactants and the Fe2O3 cores in a single step.
Cloud Computing Operations Research
Authors: Iyoob Ilyas , Zarifoglu Emrah , Dieker A. B.
Published: March 2013

This paper argues that the cloud computing industry faces many decision problems where operations research (OR) could add tremendous value. To this end, we provide an OR perspective on cloud computing in three ways. First, we compare the cloud computing process with the traditional pull supply chain and introduce the cloud IT supply chain as the system of moving information from suppliers to consumers through the cloud network. Second, based on this analogy, we organize the cloud computing decision space by identifying the problems that need to be solved by each player in the supply chain—namely, (1) cloud providers, (2) cloud consumers, and (3) cloud brokers. We list the OR problems of interest from each player's perspective and discuss the tools that may need to be developed to solve them. Third, we survey past and current research in this space and discuss future research opportunities in cloud computing operations research.
Retained surgical sponges, needles and instruments
Authors: Hariharan D , Lobo DN
Published: March 2013

Introduction

Retained sponges and instruments (RSI) due to surgery are a recognised medical ‘never event’ and have catastrophic implications for patients, healthcare professionals and medical care providers. The aim of this review was to elucidate the extent of the problem of RSI and to identify preventative strategies.

Methods

A comprehensive literature search was performed on MEDLINE®, Embase™, the Science Citation Index and Google™ Scholar for articles published in English between January 2000 and June 2012. Studies outlining the incidence, risk, management and attempts to prevent RSI following surgical intervention were retrieved.

Results

The overall incidence of RSI is low although its incidence is substantially higher in operations performed on open cavities. Sponges are the most commonly retained item when compared with needles and instruments. Clinical presentation is varied, leading to avoidable morbidity, and the error is indefensible medicolegally. Risk factors include emergency operations, operations involving unexpected change in procedure, raised body mass index, and a failure to perform accurate sponge and instrument counts. The existing strategy for prevention is manual counting of sponges and instruments undertaken by surgical personnel. This, however, is fallible. Computer assisted counting of sponges using barcodes and gauze sponges tagged with a radiofrequency identification device aiding manual counting have been trialled recently, with success.

Conclusions

Vigilance among operating theatre personnel is paramount if RSI is to be prevented. Prospective multicentre trials to assess efficacy of new technologies aiding manual counting should be undertaken if this medical error is to be eliminated completely.
The Clinical Significance of Urinary Neopterin in the Follow-up of Patients after Exeresis of a Malignant Melanoma
Authors: Mura P. , Barriere M. , Papet Y. , Reiss D. , Camenen I. , Vaillant L. , Lorette G.
Published: March 2013

Serial urinary neopterin determinations were performed in 151 patients after exeresis of a malignant melanoma. Values for patients clinically free of disease at the end of the observation were similar to those of healthy subjects. No significant varia tions were observed in patients with cutaneous meta stases. The most important variations were found in patients who developed ganglionic and above all visceral metastases. These data suggest that neopterin determination could be very useful in the follow-up of patients with a malignant melanoma and especially for detecting visceral metastases occurences.
Insights into Enzymic Catalysis from Studies on Dihydrofolate Reductases
Authors: Benkovic Stephen J. , Adams Joseph A. , Fierke Carol A. , Naylor Adel M.
Published: March 2013

The role of DHFR in the maintenance of cellular DNA has sparked wide interest in the structure and dynamics of this enzyme. Kinetic studies of specific amino acid replacements on the enzyme isolated from E. coli has proved useful in the detailing of hydrophobic and ionic interactions both proximal and distal to the site of chemical transformation (e. g. Phe-31, Leu-54 and Arg-44). Despite the low sequence homology shared by the E. coli and L. easei enzymes, the free energy profiles are surprisingly comparable. This probably is the result of the high degree of structural similarity of the active site surfaces, but the deleterious effects of subtle replacements (e. g. Leu-54-Ile) at strictly conserved amino acids underscore the latters unique role in attaining the required catalytic efficiency for the enzyme.
Pteridines, LXXXVIII. Oxidations and Reactions of 2- and 4-Thiolumazine Derivatives. Synthesis and Properties of Pteridine-Sulfinates and -sulfonates
Authors: Bartke Michael , Pfleiderer Wolfgang
Published: March 2013

Selective oxidations of 2-thiolumazines (10-12) by H20 2 and KMn04 respectively in basic medium led to the corresponding stable pteridin-4-one-2-sulfinates (13-15) and -sulfonates (16-18), which can be isolated in the form of their potassium salts. On oxidation of 6,7-diphenyl-2-thiolumazine (12) with 1 equivalent of H20 2 resulted the 6,7-diphenyl-pteridin-4-one-2-sulfenate (22), which is regarded as an intermediate in the formation of the sulfinates. Characterization was done by elemental analysis, pKa determination, and UV-, IR- and IH-NMR-spectra.

Acid and base hydrolyse the sulfinate and sulfonate groups to the 2-hydroxy derivative. Treatment of the pteridin-4-one-2-sulfinate with strong anhydrous acids such as formic acid or sulfuric acid affects S02 elimination to the corresponding 2-H-pteridin-4-one (19-21).

The oxidative desulfurization of 2-thiolumazines can be achieved directly with H20 2 and m-chloroperbenzoic acid in formic acid. Analogously nucleophilic displacement reactions of the 2-thione group proceeded under mild conditions by H20 2 oxidation in the presence of various amines to give the corresponding pterin derivatives (25.-;-32, 36-39). 6,7-Diphenyl-4-thiolumazine (44) shows similar reactions on oxidation in the presence of amines (43, 54), but the corresponding 4-sulfinate and sulfonate are too unstable in this series to be isolated. S02 elimination does not take place since hydrolysis is the preferred reaction mode.
Pteridines, IXC. Synthesis, Oxidations and Reactions of 6- and 7-Hydroxy-2-thiolumazines Selective Cytotoxicity of Carboxypeptidase-activated Methotrexate ex-Peptides
Authors: Bartke Michael , Pfleiderer Wolfgang
Published: March 2013

Various 6-(10, 11) and 7-hydroxy-2-thiolumazines (8,9) have been synthesized and oxidations of the thioamide function studied . H20 2 Oxidation of 7-hydroxy-2-thiolumazine (8) in basic medium leads to pteridine-4,7- dione-2-sulfinate (12), which eliminates S02 in anhydrous acids. Oxidative desulfurization of 8 and its 8- methyl derivative 9 proceeds directly in formic acid with H20 2 and m-chloroperbenzoic acid to give 16 and 17 respectively. KMn04 oxidation forms the pteridine-4,7,dione-2-sulfonates (14, 15), which react under hydrolytic conditions to give the corresponding 2-hydroxy derivtives (18, 19) and on displacement with ammonium acetate/ammonia at elevated temperature form the pterin derivatives 20 and 21.

2-Thio-pteridine-4,6-dione (10) oxidizes also to the corresponding 2-sulfonate (22), which could only be isolated after addition of potassium bisulfite in the form of the dipotassium 7,8-dihydropteridine-4,6-dione- 2,7-disulfonate (23) adduct.

The newly synthesized compounds have been characterized by elemental analyses, pKa determinations, UVand IH-NMR-spectra.
Selective Cytotoxicity of Carboxypeptidase-activated Methotrexate ex-Peptides
Authors: Vitols Karin S. , Montejano Yolanda D. , Kuefner Ulrike , Huennekens F. M.
Published: March 2013

Methotrexate ex-pep tides (derivatives in which an amino acid is linked covalently to the ex-carboxyl of the glutamate residue on the parent drug) can be hydrolyzed by specific carboxypeptidases to yield free Methotrexate (MTX) and the corresponding amino acid. Studies with L12l0 cells in suspension culture have shown that the MTX pep tides can serve as "pro-drugs": Because of their inability to be taken up by cells, they are relatively non-toxic. When co-administered with appropriate carboxypeptidases, however, they become equitoxic with MTX. In the present investigation, the potential of the MTX-ala/carboxypeptidase A combination for providing regional cytotoxicity was demonstrated in a model system involving L12l0 cells propagated in semi-solid agarose. When cells and one of the components (MTX peptide or carboxypeptidase) were distributed uniformly throughout the agarose, and the other component was immobilized at the center, a discrete zone of cell kill radiated from the fixed component. These results suggest the possibility of developing a new mode of cancer chemotherapy involving circulating MTX peptides in conjunction with carboxypeptidases linked covalently to tumor-targeted monoclonal antibodies.
Pterin Metabolism In Haemodialysis Patients
Authors: Altmann Paul , Sawyer Nick , Cunningham John , Marsh Frank , Hamon Chris , Blair John A.
Published: March 2013

Patients undertaking maintenance haemodialysis may develop a variety of neurological disorders, the most serious of which is aluminium induced encephalopathy. Abnormally raised serum concentrations of pterins are found in dialysis patients, and neonates with tetrahydrobiopterin deficiency develop mental dysfunction. Dihydropteridine reductase, essential for maintenance of normal levels of tetrahydrobiopterin, is inhibited when aluminium is added to brain homogenate at similar concentrations to those found in aluminium encephalopathy. We have previously shown that erythrocyte dihydropteridine reductase activity was reduced in non-encephalopathic dialysis patients and inversely related to serum aluminium concentration. Concentrations of serum biopterin derivatives were raised but not related to either aluminium or dihydropteridine reductase.

In this study of 17 haemodialysis patients, serum biopterin (13.6 ± 1.3 μg/l) and neopterin (66.2 ± 7.4 μg/l) concentrations were raised compared with normal subjects' biopterin (2.4 ± 0.4 g/l) and neopterin (2.8 ± 0.4 μg/l) values (p = 0.0001). When neopterin and biopterin concentrations were corrected for predialysis serum creatinine a weak relationship appeared between them (r = 0.49, P = 0.04). Erythrocyte dihydropteridine reductase was not related to the creatinine corrected neopterin (r = -0.5, p = 0.2), but there was a significant relationship between DHPR and corrected biopterin (r = 0.986, p = 0.0001) and between corrected biopterin and bone aluminium content (r = 0.68, P = 0.03).

Our results support the possibility that aluminium causes changes in pterin metabolism which are analogous to those found in Type II hyperphenylalaninaemia. Serum biopterin concentration, corrected for pre-dialysis serum creatinine, can be used satisfactorily to study tetrahydrobiopterin metabolism in haemodialysis patients. However neopterin/biopterin ratios are unpredictably disturbed and cannot be so used. Serum neopterin concentrations are raised more than anticipated from the biopterin concentrations, and this may be due to neopterin release from macrophages activated by dialysis membranes and/or reduced conversion of dihydroneopterin triphosphate to tetrahydrobiopterin.