Heterocyclic Functionalized Donor-Acceptor Hole-Transporting Materials for Inverted Perovskite Solar Cells

Hole transport materials (HTMs) with appropriate energy levels and comprehensive passivation effects help to obtain highly efficient and stable perovskite solar cells (PSCs). Electron-deficient character-induced HTMs can generate varying energy level alignments near the HTM/perovskite interface. Herein, we report the synthesis and investigation of two new dipolar HTMs, WWC103 and WWC105, based on 2-(1,1-dicyanomethylene)rhodamine and 4-cynophenylacetonitrile acceptors, enabling high-efficiency mixed-cation mixed-halide perovskite solar cells. Apart from having different acceptors, these HTMs are built on a heterocyclic frame, which can provide passivation effects and improve the morphology of the perovskite layer. As a result, these dopant-free HTM-based solar cells show a high open-circuit voltage and good power conversion efficiency. Among both, the solar cell based on the HTM with 2-(1,1-dicyanomethylene)rhodamine exhibits a high open-circuit voltage of 1.09 V with a champion power conversion efficiency of over 20.51%. The improved performance of WWC103 over WWC105 (19.74%) is attributed to the new acceptor, which, in addition to providing good energy-level alignments and hole mobility, also holds the ability to passivate the defects. The findings suggest a new acceptor unit for constructing dopant-free HTMs for efficient PSCs.

Hyper-viscoelastic mechanical behavior of cranial pia mater in tension

BACKGROUND

Cranial pia mater, the innermost layer of the meninges, protects the central nervous system by tightly wrapping the brain and damping the external impact force to the brain. Accurate experimental data of the mechanical property of the cranial pia mater can enhance the theoretical prediction of traumatic brain injury or the scientific surgery design for brain disease. The aim of this study is to characterize the mechanical behavior of the cranial pia mater.

METHODS

In vitro tensile and stress-relaxation experiments of ovine cranial pia mater specimens were conducted at eight strain rates to characterize the rate-dependent viscoelastic property. The tensile and stress-relaxation experimental data were fitted by an Ogden hyper-viscoelastic model with a strain rate function to describe the mechanical behavior of the cranial pia mater.

FINDINGS

The elastic modulus and the ultimate stress are significantly increased from 5.545 MPa and 0.535 MPa at 0.00167 s^-1 to 18.345 MPa and 2.547 MPa at 0.83 s^-1 (p < .0001), respectively. The initial stress and the long-term stress (300 s) are also increased significantly with the increasing strain rates (p < .0001). A good fit of the experimental data with the Ogden hyper-viscoelastic model incorporated with a strain rate function was achieved (R² > 0.93).

INTERPRETATION

The cranial pia mater exhibits as a rate-dependent hyper-viscoelastic material in the tensile and stress-relaxation experiments. Compared with the brain, the stiffer nature of the cranial pia mater indicates its essential role in brain protection. The rate-dependent constitutive model provides a proper description of the hyper-viscoelastic characteristics of the cranial pia mater in tension and may provide a basic constitutive relationship for numerical simulations of traumatic brain injury.

Prognosis and clinicopathologic features in patients with gastric stump cancer after curative surgery

Background

Gastric stump ("remnant") cancer is the development of a malignancy related to previous gastric surgery. Prognosis in gastric stump cancer, compared with that in primary gastric cancer, is still controversial.

Methods

From January 1988 to December 2012 at a single medical centre in Taiwan, 105 patients with gastric stump cancer, including 85 with previous peptic ulcer disease and 20 with previous gastric cancer, were analyzed for clinicopathologic characteristics and overall survival (os).

Results

The 5-year os rates for patients with gastric stump cancer and with primary gastric cancer were 51.2% and 54.5% respectively (p = 0.035). Analysis of clinicopathologic characteristics indicated that, compared with patients having primary gastric cancer, those with gastric stump cancer had more lymph node metastasis (p < 0.001) and had been diagnosed at a more advanced stage (p = 0.047). Multivariate analysis with os as an endpoint showed that age [p = 0.015; hazard ratio (hr): 2.300; 95% confidence interval (ci): 1.173 to 4.509], tumour size (p = 0.037; hr: 1.700; 95% ci: 1.031 to 2.801), stromal reaction (p = 0.021; hr: 1.802; 95% ci: 1.094 to 2.969), and pathologic N category (p = 0.001; hr: 1.449; 95% ci: 1.161 to 1.807) were independent predictors in gastric stump cancer. The os rates for patients with gastric stump cancer who previously had gastric cancer or peptic ulcer disease were 72.9% and 50.0% respectively (p = 0.019). The Borrmann classification was more superficial (p = 0.005), lymph node metastases were fewer (p = 0.004), and staging was less advanced (p = 0.025) in patients with gastric stump cancer who previously had gastric cancer than in their counterparts who previously had peptic ulcer disease.

Conclusions

Survival is poorer in patients with gastric stump cancer who previously had peptic ulcer disease than in those who previously had primary gastric cancer. Patients with gastric stump cancer who previously had gastric cancer and could receive curative gastrectomy tended to have a better prognosis because of a more superficial Borrmann classification. Regular follow-up in patients who have undergone gastric surgery is recommended for the early detection of gastric stump cancer.

PARP-1 Involvement in Autophagy and Their Roles in Apoptosis of Vascular Smooth Muscle Cells under Oxidative Stress

Autophagy and poly(ADP-ribose) polymerase 1 (PARP-1) are activated and involved in a series of cell processes under oxidative stress, which is associated with pathogenesis of atherosclerosis. Research on their relationship under oxidative stress has been limited. In this study, we aimed to investigate the activation, relationship, and role of autophagy and PARP-1 in vascular smooth muscle cell (VSMC) death under oxidative stress. This study explored the signal molecule PARP-1 and autophagy in VSMCs using gene silencing and the hydrogen peroxide (H2O2)-stimulated oxidative stress model. We observed that H2O2 could induce autophagy in VSMCs, and the inhibition of autophagy could protect VSMCs against oxidative stress-mediated cell death. Meanwhile, PARP-1 could also be activated by H2O2. Additionally, we analysed the regulatory role of PARP-1 in oxidative stress-mediated autophagy and found that PARP-1 was a novel factor involved in the H2O2-induced autophagy via the AMPK-mTOR pathway. Finally, PARP-1 inhibition protected VSMCs against caspase-dependent apoptosis. These data suggested that PARP-1 played a critical role in H2O2-mediated autophagy and both of them were involved in apoptosis of VSMCs.

Adiabatic light transfer in titanium diffused lithium niobate waveguides

We report on the realization of adiabatic light transfer in lithium niobate (LiNbO₃) waveguides. This peculiar adiabatic tunneling scheme was implemented in a three-waveguide coupling configuration with the intermediate waveguide being inclined with respect to the outer waveguides to facilitate the adiabatic passage process. We have investigated and determined the adiabatic conditions of the LiNbO₃ device in terms of the structure configuration of the waveguide system and found optimal structure parameters by both simulation and experimental approaches. Broadband adiabatic couplings of bandwidth ~456 and 185 nm and peak coupling efficiencies of >0.96 have been obtained with a 2-cm long device for TE- and TM-polarized fundamental modes, respectively. Longer (5 cm) devices were also studied and found to be useful in increasing the adiabaticity of the device, especially for the TM-polarized mode.

Serum brain-derived neurotrophic factor levels and psychotic symptoms in heroin dependence

OBJECTIVES

Psychotic symptoms are commonly observed among heroin users. Low serum brain-derived neurotrophic factor (BDNF) levels have been reported in schizophrenia and psychosis; however, studies assessing the relationship between serum BDNF levels and psychotic symptoms in heroin dependence are lacking.

METHOD

A total of 31 heroin-dependent patients who had never experienced psychotic symptoms during heroin consumption and 21 patients with a history of psychotic symptoms were consecutively recruited. We measured by enzyme-linked immunosorbent assay (ELISA) serum BDNF levels during early abstinence. A gender- and age-matched sample of healthy controls was also recruited and underwent measurement of BDNF.

RESULTS

BDNF levels were significantly lower in patients with psychotic symptoms than in those without psychotic symptoms (P<0.001). BDNF levels were not found to be correlated with sex, age, age of onset, duration of heroin use, average daily dose of heroin use, frequency of heroin use, SDS scores, BAI scores and BDI scores in the psychotic subsamples (all P>0.05).

CONCLUSIONS

Our findings suggest that heroin-dependent patients with psychotic symptoms share some of the neurotrophic insult that characterizes schizophrenia and psychosis.

microRNA-221 and microRNA-18a identification in stool as potential biomarkers for the non-invasive diagnosis of colorectal carcinoma

BACKGROUND

The detection of microRNA (miRNA) dysregulation in stool is a novel approach for the diagnosis of colorectal carcinoma (CRC). The aim of this study is to investigate the use of miR-221 and miR-18a in stool samples as non-invasive biomarkers for CRC diagnosis.

METHODS

A miRNA expression array containing 667 miRNAs was performed to identify miRNA dysregulation in CRC tissues. We focused on miR-221 and miR-18a, two significantly upregulated miRNAs which were subsequently verified in 40 pairs of CRC tissues and 595 stool samples (198 CRCs, 199 polyps and 198 normal controls).

RESULTS

miR-221 and miR-18a were upregulated in the miRNA expression array. miR-221 and miR-18a levels were also significantly higher in 40 CRC tumours compared with their respective adjacent normal tissues. In stool samples, miR-221 and miR-18a showed a significant increasing trend from normal controls to late stages of CRC (P<0.0001). The levels of stool miR-221 and miR-18a were both significantly higher in subjects with stages I+II (miR-221: P<0.0001, miR-18a: P<0.0001) and stages III+IV of CRC (miR-221: P=0.0004, miR-18a: P<0.0001) compared with normal controls. The AUC of stool miR-221 and miR-18a were 0.73 and 0.67 for CRC patients as compared with normal controls, respectively. No significant differences in stool miR-221 and miR-18a levels were found between patients with proximal and distal CRCs. The use of antibiotics did not influence stool miRNA-221 and miRNA-18a levels.

CONCLUSIONS

Stool-based miR-221 can be used as a non-invasive biomarker for the detection of CRC.

Phylogenetic relationships among Octopodidae species in coastal waters of China inferred from two mitochondrial DNA gene sequences

Octopus in the family Octopodidae (Mollusca: Cephalopoda) has been generally recognized as a "catch-all" genus. The monophyly of octopus species in China's coastal waters has not yet been studied. In this paper, we inferred the phylogeny of 11 octopus species (family Octopodidae) in China's coastal waters using nucleotide sequences of two mitochondrial DNA genes: cytochrome c oxidase subunit I (COI) and 16S rRNA. Sequence analysis of both genes revealed that the 11 species of Octopodidae fell into four distinct groups, which were genetically distant from one another and exhibited identical phylogenetic resolution. The phylogenies indicated strongly that the genus Octopus in China's coastal waters is also not monophyletic, and it is therefore clear that the Octopodidae systematics in this area requires major revision. It is demonstrated that partial sequence information of both the mitochondrial genes 16S rRNA and COI could be used as diagnostic molecular markers in the identification and resolution of the taxonomic ambiguity of Octopodidae species.

Complete mitochondrial genome of Abramis brama orientalis Berg (cypriniformes, Cyprinidae, Leuciscinae)

In this study, we cloned and sequenced the complete mitochondrial genome of Abramis brama orientalis Berg. The genome was 16,610 bp (LR) in length and consisted of 13 protein-coding genes, 22 tRNA genes, 2 ribosomal RNA genes and 2 main non-coding regions [the control region (CR) and the origin of the light strand replication], the gene composition and order of which was similar to those reported from other fish mitochondrial genomes. The overall base composition of the heavy strand was T 26.7%, C 26.5 %, A 30.0% and G 16.8%, with a slight A+T bias of 56.7%. This mitogenome sequence data would play an important role in population genetics and phylogenetic analysis of the Leuciscinae.

microRNA-7 is a novel inhibitor of YY1 contributing to colorectal tumorigenesis

Using microRNA (miRNA) expression array, we identified that miR-7 was deregulated in colorectal cancer (CRC). We studied the biological role and molecular target of miR-7 in CRC. miR-7 was downregulated in six out of seven colon cancer cell lines. Ectopic expression of miR-7 suppressed colon cancer cell proliferation (P<0.05), induced apoptosis (P<0.05) and caused cell-cycle arrest in G1 phase (P<0.05). The tumor suppressive function of miR-7 was further confirmed in nude mice (P<0.05). The 3'-untranslated region (3'UTR) of Yin Yang 1 (YY1) mRNA contains an evolutionarily conserved miR-7 binding site using in silico searches, luciferase reporter assay and western blot analysis confirmed that miR-7 directly bound to YY1 3'UTR to negatively regulate the protein expression of YY1 in colon cancer cell lines HCT116 and LOVO. Intriguingly, knock-down of YY1 in three colon cancer cell lines (HCT116, LOVO and DLD1) consistently suppressed cell proliferation (P<0.01) and induced apoptosis (P<0.01), indicating the opposite functions of miR-7 and YY1 in CRC. Consistent with these data, ectopic expression of YY1 promoted cell growth by increasing proliferation (P<0.01) and suppressing apoptosis (P<0.001). The tumorigenic ability of YY1 was further confirmed in vivo in xenograft-nude mouse model (P<0.01). In addition, pathway analyses revealed that the oncogenic effect by YY1 was associated with inhibiting p53 and modulating its downstream effectors p15, caspase cascades and C-Jun, and activating Wnt signaling pathway through activating β-catenin, anti-apoptotic survivin and fibroblast growth factor 4. Furthermore, multivariate analysis revealed that patients with YY1 protein high expression had a significant decrease in overall survival, and Kaplan-Meier survival curves showed that these patients had significantly shorter survival than others (P<0.0001). In conclusion, MiR-7 is a novel miRNA with tumor suppressive function in colon cancer by targeting oncogenic YY1. YY1 promotes colon cancer growth through inhibiting p53 and promoting Wnt signaling pathways and serves as an independent prognostic biomarker for CRC patients.

Recurrent laryngeal nerve injury in video-assisted thyroidectomy: lessons learned from neuromonitoring

INTRODUCTION

The objective of the study was to assess the mechanism of recurrent laryngeal nerve (RLN) injury during video-assisted thyroidectomy (VAT).

METHODS

The study examined 201 nerves at risk (NAR). VAT with laryngeal neuromonitoring (LNM) was outlined according to this scheme: (a) preparation of the operative space; (b) vagal nerve stimulation (V1); (c) ligature of the superior thyroid vessels; (d) visualization, stimulation (R1), and dissection of the RLN; (e) extraction of the lobe; (f) resection of the thyroid lobe; (g) final hemostasis; (h) verification of the electrical integrity of the RLN (V2, R2). The site, cause, and circumstance of nerve injury were elucidated with the application of LNM. Laryngeal nerve injuries were classified into type 1 injury (segmental) and 2 (diffuse).

RESULTS

Fourteen nerves (6.9 %) experienced loss of R2 and V2 signals. 80 percent of lesions occurred in the distal 1 cm of the course of the RLN. The incidence of type 1 and 2 injuries was 71 and 29 % respectively. The mechanisms of injury were traction (70 %) and thermal (30 %). Traction lesions were created during the extraction of the lobe from the mini-incision [point (e)]. Thermal injury occurred during energy-based device use in (f) and (g) circumstances.

CONCLUSIONS

RLN palsy still occurs with routine endoscopic identification of the nerve, even combined with LNM. LNM has the advantage of elucidating the mechanism of RLN injury. Traction and thermal RLN injuries are the most frequent lesions in VAT.

The effect of pH on the functionalization of nylon fabric with carbon nanotubes

Single walled carbon nanotubes (SWCNTs) were dispersed in water and attached to nylon fabrics by a dip-drying procedure; scanning electron microscopy and Raman spectroscopy suggest the attachment of the SWCNTs. The electrical resistance of the functionalized fabrics is found to be pH-dependent, which is correlated with the quantity of SWCNTs dispersed in water at different values of pH. This can be further ascribed to the influence of the pK(a) of the acid (e.g., acetic acid in this study) used to tune pH. The acid may affect the dispersion of SWCNTs through two different mechanisms: (1) the free protons may protonate the amine and/or sulfonate group in the dye molecules, resulting in a variety of interactions among the dye molecules, SWCNTs and water molecules and (2) the resulting ions may increase the ionic strength of the solution, compressing the electric double layers of SWCNT colloids and thus impairing their stability. The former possibility is ruled out by data obtained using X-ray photoelectron spectroscopy, Raman spectroscopy, and ultraviolet-visible-near infrared spectroscopy; thus the latter is proposed to account for the experimental results. The colour strength of the functionalized fabrics increases with increasing pH, which is in agreement with their measured electrical properties.

Numerical simulation of microneedles' insertion into skin

Microneedles have recently received much attention as a novel way for transdermal drug delivery. In this paper, a numerical simulation of the insertion process of the microneedle into human skin is reported using the finite element method. A multilayer skin model consisting of the stratum corneum, dermis and underlying hypodermis has been developed. The effective stress failure criterion has been coupled with the element deletion technique to predict the complete insertion process. The numerical results show a good agreement with the reported experimental data for the deformation and failure of the skin and the insertion force. The influences of the mechanical properties of the skin and the microneedle geometry (e.g. tip area, wall angle and wall thickness) on the insertion force are discussed. The numerical results are helpful for the optimum design of the microneedles for the transdermal drug delivery system.

MicroRNA dysregulation in colorectal cancer: a clinical perspective

Recent researches have shed light on the biological importance of microRNAs (miRNAs) in colorectal cancer (CRC) genesis, progression and response to treatments. The potential utility of miRNAs in the preclinical stage have been explored and investigated. In this review, we explored the literature and reviewed the cutting edge progress in the discovery of noninvasive plasma and faecal miRNAs for CRC early diagnosis, as well as their measurability and predictability. We also discussed the utility of miRNAs as novel prognostic and predictive markers, and their association with CRC clinical phenotypes including recurrence, metastasis and therapeutic outcomes. Finally, we summarised miRNA-related single-nucleotide polymorphisms and their potential influence on sporadic CRC susceptibility and therapeutic response. In conclusion, the use of miRNAs as biomarker for CRC is still in its infancy and need further characterisation and evaluation.

Electric field assisted manipulation of microdroplets on a superhydrophobic surface

The efficient manipulation of low-volume droplets offers many potential applications in relation to chemical and biomedical tests and protocols. A novel approach to the manipulation of a microdroplet on a superhydrophobic surface is introduced in the present communication. The microdroplet was first picked up onto a hydrophilic needle, transported from one location to another, and finally released under the action of an electric field force. Three key parameters in this process, the radius of the droplet, the distance between the two electrodes, and the required voltage, were investigated. This study should be helpful for the design of microfluidic devices.

Epigenetic inactivation of T-box transcription factor 5, a novel tumor suppressor gene, is associated with colon cancer

T-box transcription factor 5 (TBX5) is a member of a phylogenetically conserved family of genes involved in the regulation of developmental processes. The function of TBX5 in cancer development is largely unclear. We identified that TBX5 was preferentially methylated in cancer using methylation-sensitive arbitrarily primed PCR. We aim to clarify the epigenetic inactivation, biological function and clinical significance of TBX5 in colon cancer. Promoter methylation was evaluated by combined bisulfite restriction analysis and bisulfite genomic sequencing. Cell proliferation was examined by cell viability assay and colony formation assay, apoptosis by flow cytometry and cell migration by wound-healing assay. TBX5 target genes were identified by cDNA microarray analysis. Cox regression model and log-rank test were used to identify independent predictors of prognosis. TBX5 was silenced or downregulated in 88% (7/8) colon cancer cell lines, but was expressed in normal colon tissues. Loss of gene expression was associated with promoter methylation. The biological function of TBX5 in human colon cancer cells was examined. Re-expression of TBX5 in silenced colon cancer cell lines suppressed colony formation (P<0.001), proliferation (P<0.001), migration and induced apoptosis (P<0.01). Induction of apoptosis was mediated through cross-talk of extrinsic apoptosis pathway, apoptotic BCL2-associated X protein and Granzyme A signaling cascades. TBX5 suppressed tumor cell proliferation and metastasis through the upregulation of cyclin-dependent kinase inhibitor 2A, metastasis suppressor 1 and downregulation of synuclein gamma and metastasis-associated protein 1 family member 2. TBX5 methylation was detected in 68% (71/105) of primary colon tumors. Multivariate analysis showed that patients with TBX5 methylation had a significantly poor overall survival (P=0.0007). In conclusion, we identified a novel functional tumor suppressor gene TBX5 inactivated by promoter methylation in colon cancer. Detection of methylated TBX5 may serve as a potential biomarker for the prognosis of this malignancy.

Epigenetic inactivation of T-box transcription factor 5, a novel tumor suppressor gene, is associated with colon cancer

T-box transcription factor 5 (TBX5) is a member of a phylogenetically conserved family of genes involved in the regulation of developmental processes. The function of TBX5 in cancer development is largely unclear. We identified that TBX5 was preferentially methylated in cancer using methylation-sensitive arbitrarily primed PCR. We aim to clarify the epigenetic inactivation, biological function and clinical significance of TBX5 in colon cancer. Promoter methylation was evaluated by combined bisulfite restriction analysis and bisulfite genomic sequencing. Cell proliferation was examined by cell viability assay and colony formation assay, apoptosis by flow cytometry and cell migration by wound-healing assay. TBX5 target genes were identified by cDNA microarray analysis. Cox regression model and log-rank test were used to identify independent predictors of prognosis. TBX5 was silenced or downregulated in 88% (7/8) colon cancer cell lines, but was expressed in normal colon tissues. Loss of gene expression was associated with promoter methylation. The biological function of TBX5 in human colon cancer cells was examined. Re-expression of TBX5 in silenced colon cancer cell lines suppressed colony formation (P<0.001), proliferation (P<0.001), migration and induced apoptosis (P<0.01). Induction of apoptosis was mediated through cross-talk of extrinsic apoptosis pathway, apoptotic BCL2-associated X protein and Granzyme A signaling cascades. TBX5 suppressed tumor cell proliferation and metastasis through the upregulation of cyclin-dependent kinase inhibitor 2A, metastasis suppressor 1 and downregulation of synuclein gamma and metastasis-associated protein 1 family member 2. TBX5 methylation was detected in 68% (71/105) of primary colon tumors. Multivariate analysis showed that patients with TBX5 methylation had a significantly poor overall survival (P=0.0007). In conclusion, we identified a novel functional tumor suppressor gene TBX5 inactivated by promoter methylation in colon cancer. Detection of methylated TBX5 may serve as a potential biomarker for the prognosis of this malignancy.

Mosquito proboscis: an elegant biomicroelectromechanical system

The mouthparts of female mosquitoes have evolved to form a special proboscis, a natural biomicroelectromechanical system (BMEMS), which is used for painlessly penetrating human skin and sucking blood. Scanning electron microscope observations show that the mosquito proboscis consists of a small bundle of long, tapering, and feeding stylets that are collectively called the fascicle, and a large scaly outer lower lip called the labium. During blood feeding, only the fascicle penetrates into the skin while the labium buckles back to remain on the surface of the skin. Here, we measured the dynamic force of penetration of the fascicle into human skin to reveal the mechanical principle underlying the painless process of penetration. High-speed video observations of movements associated with insertion of the fascicle indicate that the "smart" mosquito does not directly pierce its victim's skin with the fascicle. Instead, it uses the two maxillas as variable frequency microsaws with nanosharp teeth to advance into the skin tissue. This elegant BMEMS enables the mosquito to insert its feeding fascicle into human skin using an exceedingly small force (average of 16.5 μN).

X-ray analysis (1. 4-A resolution) of avian pancreatic polypeptide: Small globular protein hormone

The crystal structure of avian pancreatic polypeptide (aPP), a 36-residue polypeptide with some hormonal properties, has been determined by using single isomorphous replacement and anomalous scattering to 2.1-A resolution. The phases were extended to 1.4-A resolution by using a modified tangent formula. The molecule contains two regions of secondary structure-an extended polyproline-like helix (residues 1-8) and an alpha-helix (residues 14-31)-that run roughly antiparallel. The packing together of nonpolar groups from these regions gives the molecule a hydrophobic core in spite of its small size. The aPP molecules form a symmetrical dimer in the crystal stabilized principally by interlocking of nonpolar groups from the alpha-helices. The aPP dimers are crosslinked by coordination of Zn(2+); three aPP molecules contribute ligands to each zinc. The coordination geometry is a distorted trigonal bipyramid. The properties of the aPP molecule in solution are consistent with expectations based on the crystal structure. The aPP molecule has several general features in common with the pancreatic hormones insulin and glucagon. All three hormones have complex mechanisms for self-association. Like insulin, aPP seems to have a stable monomeric structure but its biological activity seems to depend on the more flexible COOH-terminal region analogous to the flexible NH(2)-terminal region of glucagon.

Comparison of photodegradative efficiencies and mechanisms of Victoria Blue R assisted by Nafion-coated and fluorinated TiO2 photocatalysts

The purposes of this research were to study the effects of two modified photocatalysts, Nafion-coated TiO(2) and fluorinated TiO(2), and photocatalytic degradation of Victoria Blue R in aqueous solution. Photocatalytic degradation of Victoria Blue R was accelerated by the modified photocatalysts. Bulk and surface characterizations of the resulting powders were carried out. Attachment of the anions to the TiO(2) surface using the Nafion-coated-TiO(2) possibly results in increased adsorption of the cationic dye, and the degradation rate is larger for the cationic dye. It was found that Victoria Blue R on the two illuminated TiO(2) surfaces underwent very different changes. To obtain a better understanding on the mechanistic details of this modified-TiO(2)-assisted photodegradation of the Victoria Blue R dye with UV irradiation, a large number of intermediates of the process were separated, identified, and characterized by a high-performance liquid chromatography-mass spectrometry technique. Several probable photodegradation pathways were proposed and discussed.

Quality of life, health satisfaction and family impact on caregivers of children with developmental delays

OBJECTIVE

To study the quality of life, health satisfaction and family impact on caregivers of children with developmental delays in Taiwan.

DESIGN

Cross-sectional study.

SUBJECTS

The caregivers of children with diagnoses of developmental delays recruited from a teaching hospital in northern Taiwan.

METHODS

The main caregivers of 48 male and 22 female children with developmental delays were recruited. WHOQOL-BREF for health-related quality of life (HRQOL), PedsQL-Health Satisfaction for health satisfaction, PedsQL-Family Impact Module and Impact on Family Scale for family impact were evaluated. The correlation of caregivers' HRQOL, health satisfaction and family impact were also studied.

RESULTS

Caregivers in nuclear families had higher health satisfaction scores (78.2 for nuclear families vs. 66.9 for extended families, P < 0.05) when assessed by the PedQL-Health Satisfaction questionnaire. Children's age was negatively correlated with family impact, including parent (-0.272, P = 0.023), family (-0.262, P = 0.029) and total scores (-0.281, P = 0.018) as assessed using the PedsQL-Family Impact Module.

CONCLUSION

A negative relation between impact of burden and child's age suggests that family members gradually adapt to the delayed developmental status in their children as they grow. Caregivers in nuclear families having higher health satisfaction than those in extended families may be due to Chinese cultural effects.

Micronanostructures of the scales on a mosquito's legs and their role in weight support

We show here that the mosquito cannot only give rise to a higher water-supporting force than the water strider if the ratio of the water-supporting force to the body weight of the insect itself is compared, but also can safely take off or land on the water surface, and also can attach on any solid surface like the fly. We found that the mosquito's legs are covered by numerous scales consisting of the uniform microscale longitudinal ridges (nanoscale thickness and microscale spacing between) and nanoscale cross ribs (nanoscale thickness and spacing between). Such special delicate microstructure and/or nanostructure on the leg surface give a water contact angle of approximately 153 degrees and give a surprising high water-supporting ability. It was found that the water-supporting force of a single leg of the mosquito is about 23 times the body weight of the mosquito, compared with a water strider's leg giving a water-supporting force of about 15 times the body weight of the insect.

Modulation of HER2 expression by ferulic acid on human breast cancer MCF7 cells

BACKGROUND

The molecular mechanisms underlying the mitogenic effect of ferulic acid (FA), an active compound derived from Angelica sinensis, have never been elucidated. It was the aim of this study to investigate the proliferative effect of FA on human breast cancer cell lines and to elucidate its modulation mechanism on HER2 expression in MCF7 line.

MATERIALS AND METHODS

By using MCF7 (oestrogen receptor-positive; ER+, HER2-low), BT474 (ER+, HER2-high), MDAMB231 (ER-, HER2-low) and SKBR3 (ER-, HER2-high) human breast cancer cell lines as in vitro models, the mitogenic effects of FA were assessed by trypan blue dye exclusion assay and DNA flow cytometry. Ferulic acid-modulated cell signalling and HER2 gene expression were evaluated in MCF7 line by Western blot and real-time RT-PCR analysis.

RESULTS

Ferulic acid ER-dependently stimulated cell proliferation on MCF7 cells in a concentration-dependent manner. The HER2 oncogene (one of the prognostic factors of breast cancer) and ESR1 gene (oestrogen receptor-alpha; ERalpha) transcription were markedly up-regulated by FA treatment. Besides, HER2 signalling and its downstream molecules such as AKT and ERK1/2 were involved in FA-modulated ERalpha and cyclin D1 synthesis. Addition of anti-HER2 antibody, trastuzumab, abrogated FA-enhanced proliferative effect on MCF7 cells, indicated a positive feedback control for the action of HER2 in this setting. The fact that the ER antagonist blocked most of the FA-up-regulated HER2 expression, and that trastuzumab down-regulated ERalpha gene expression, suggested a cross-talk between ERalpha and HER2 signalling on MCF7 cells.

CONCLUSION

The authors' conclude that FA causes human breast cancer cell proliferation by up-regulation of HER2 and ERalpha expression.

Stage migration influences on stage-specific survival comparison between D1 and D3 gastric cancer surgeries

AIMS

We evaluate the influency stage migration in a randomised trial comparing D1 (N 1 lymphadenectomy) and D3 (N 1, 2 and 3 lymphadenectomy) dissections.

METHODS

Two hundred and thirteen curatively resected patients were analysed, with this TNM data.

RESULTS

After applying D3 patients' data according to simulated D1 staging, D3 resections were associated with up-staging to N2-3 levels in 8% of patients according to the N stage. The likelihood of N-status migration increased with increasing depth of invasion into the gastric wall. The increases in the calculated survival rate after stage migration on known 5-year survival rates were: 2% in stage IB, 1% in stage II, 4% in stage IIIA, and 1% in stage IIIB.

CONCLUSIONS

Stage migration secondary to meticulous lymph node dissection affects stage-specific survival rates. True therapeutic survival benefit of D3 resection can only be assessed in this context.

Copper proteinate in weanling pig diets for enhancing growth performance and reducing fecal copper excretion compared with copper sulfate

Two 28-d experiments were conducted to evaluate the efficacy of low dietary concentrations of Cu as Cu-proteinate compared with 250 ppm Cu as CuSO4 with growth performance, plasma Cu concentrations, and Cu balance of weanling swine as the criteria. In the production study (Exp. 1), 240 crossbred pigs that averaged 19.8 d of age and 6.31 kg BW initially were group-fed (two or three pigs per pen) the basal diets (Phase 1: d 0 to 14 and Phase 2: d 14 to 28) supplemented with 0 (control), 25, 50, 100, or 200 ppm Cu as Cu-proteinate, or 250 ppm Cu as CuSO4 (as-fed basis). The basal diets contained 16.5 ppm Cu supplied as CuSO4 before supplementation with Cu-proteinate or 250 ppm Cu as CuSO4. There were quadratic responses (P < or = 0.05) in ADFI and ADG for wk 1, Phases 1 and 2, and overall because ADFI was higher for pigs fed 25 or 50 ppm Cu as Cu-proteinate, and ADG increased with increasing Cu-proteinate up to 50 ppm Cu. The Cu-proteinate treatment groups combined had a higher (P < or = 0.05) Phase 2 and overall ADFI and ADG than the CuSO4 group. In the mineral balance study (Exp. 2), 20 crossbred barrows that averaged 35 d of age and 11.2 kg/BW initially were placed in individual metabolism pens with total urine and fecal grab sample collections on d 22 to 26. Treatments were the basal Phase 2 diet supplemented with 0, 50, or 100 ppm Cu as Cu-proteinate, or 250 ppm Cu as CuSO4 (as-fed basis). Treatments did not differ in growth performance criteria. There were linear increases (P < 0.001) in Cu absorption, retention, and excretion (milligrams per day) with increasing Cu-proteinate. Pigs fed 100 ppm Cu as Cu-proteinate absorbed and retained more Cu and excreted less Cu (mg/d, P < or = 0.003) than pigs fed 250 ppm Cu as CuSO4. Plasma Cu concentrations increased linearly (P = 0.06) with increasing Cu-proteinate. In conclusion, weanling pig growth performance was increased by 50 or 100 ppm Cu as Cu-proteinate in our production Exp. 1, but not in our balance Exp. 2, compared with 250 ppm Cu as CuSO4. However, 50 or 100 ppm Cu as Cu-proteinate increased Cu absorption and retention, and decreased Cu excretion 77 and 61%, respectively, compared with 250 ppm Cu as CuSO4.

Antioxidant supplementation may improve renal transplant function: A preliminary report

Dysfunction of the renal graft may not only be due to rejection but also other causes such as ischemia and reperfusion injury and calcineurin inhibitor nephrotoxicity. Antioxidant free radical scavengers may decrease oxidative stress and lipid peroxidation. Previous animal studies suggest that vitamins C (ascorbic acid) and E (alpha-tocopherol) are both strong antioxidants, that decrease oxidative stress caused by ischemia-reperfusion injury and calcineurin inhibitor nephrotoxicity. But there have been only limited reports about clinical efficacy. We report five cases supplemented with vitamin C (500 mg per day), vitamin E (500 mg per day), or both. After a 1- to 3-month prescription, the serum creatinine level decreased more than 20% from the original value. Interestingly, one patient had this experience: he ceased vitamin E for 1 month due to noncompliance. The serum creatinine level increased more than 50%. When he took vitamin E again, his serum creatinine level declined and returned to the previous level. From our limited experience, antioxidant supplementation with vitamin C or E may improve renal transplant function, especially in grafts donated from marginal donors.

Randomized clinical trial of morbidity after D1 and D3 surgery for gastric cancer

BACKGROUND

A randomized comparison of D1 (level 1 lymphadenectomy) and D3 (levels 1, 2 and 3 lymphadenectomy) dissection was performed to evaluate morbidity and effects on survival from gastric cancer.

METHODS

A total of 221 patients were studied after resection for gastric cancer, 110 after D1 surgery and 111 after D3 surgery.

RESULTS

The morbidity rate was higher after D3 than after D1 resection (17.1 (95 per cent confidence interval (c.i.) 10.1 to 24.1) versus 7.3 (95 per cent c.i. 2.4 to 12.2) per cent respectively; P = 0.012). The difference was largely related to abdominal abscess (8.1 per cent after D3 versus none after D1 resection; P = 0.003). The D3 group had an anastomotic leak rate of 4.5 per cent whereas there was no leakage in the D1 group (P = 0.060). All anastomotic leaks were minor and were managed non-operatively with nutritional support. Patients who had D3 resection had longer operating times, greater blood loss and postoperative drain outputs, and more patients needed blood transfusion. There was no death in either group. The hospital stay was longer after D3 than D1 surgery (mean(s.d.) 19.6(13.9) (range 10-98) versus 15.0(4.0) (range 10-30) days; P = 0.001).

CONCLUSION

Extended lymphadenectomy for gastric cancer is associated with more complications than limited lymphadectomy but this does not lead to significant mortality.

The association of a cystatin C gene polymorphism with late-onset Alzheimer's disease and vascular dementia

A polymorphism in the cystatin C (CST3) gene was suggested to associate with Alzheimer's disease (AD). In the present study we attempted to determine the association between CST3 polymorphism and AD or vascular dementia (VD), and whether such effects are dependent of the APOE4 allele. The polymorphisms of CST3 genotype were determined using polymerase chain reactions (PCR) followed by gel electrophoresis in 124 AD, 70 VD, and 115 control individuals. No statistical difference in CST3B allele frequencies was observed among all three groups. Associations between CST3B/B genotype and AD patients older than 75-year-old, or VD patients younger than 75-year-old were evident. The APOE4 allele alone significantly increased the odds for the developing AD, but not VD. A logistic regression analysis revealed that either CST3 or its interaction with APOE4 were not significant predictors of AD. However, a synergistic association of CST3 and APOE4 alleles was observed in predicting VD patients. These results suggest that CST3 might interact with APOE4 on conferring vascular pathologies.

Prolonged jaundice following percutaneous coronary intervention and ticlopidine therapy

Ticlopidine, an adenosine diphosphate receptor blocker, is widely used to prevent subacute stent thrombosis after percutaneous coronary intervention. Along with neutropenia and thrombotic thrombocytopenic purpura, cholestatic hepatitis is one of the most serious potential side-effects of ticlopidine therapy. Four patients with prolonged jaundice after ticlopidine therapy, including one fatal case, are presented. Alternative antithrombotic therapy for subsequent percutaneous coronary intervention is also described. Clopidogrel therapy was found to be safe and effective in two patients with a history of ticlopidine-related cholestatic hepatitis.

Kinetics of coupling reactions that generate monothiophosphate disulfides: implications for modification of RNAs

The inclusion of guanosine-5'-monothiophosphate (GMPS) in an in vitro transcription reaction facilitates enzymatic synthesis of an RNA transcript with a monothiophosphate group at the 5' end. A kinetic study of the modification reactions that generate monothiophosphate disulfide linkages with either 5'-GMPS alone or 5'-GMPS-primed RNA as the substrate revealed that the second-order rate constants increased as the pH was decreased. For example, when the reaction pH was lowered from 8 to 4, the k2 value for the coupling reaction between N-(6-[biotinamido]hexyl)-3'-(2'-pyridyldithio)propionamide (biotin-HPDP) and GMPS increased 67-fold from 1.84 to 123 M(-1) x s(-1). In addition to discussing a possible mechanism for coupling reactions that involve GMPS and disulfides, we also indicate conditions that are likely to be optimal for modification of the nucleophilic sulfur in 5'-GMPS-primed RNAs.

Up-regulation of Fas ligand expression by human cytomegalovirus immediate-early gene product 2: a novel mechanism in cytomegalovirus-induced apoptosis in human retina

Human CMV (HCMV) is an important pathogen that causes widespread diseases in immunocompromised individuals. Among the opportunistic HCMV infections, HCMV retinitis is most common in transplant recipients and AIDS patients. It often leads to blindness if left untreated. The question as to how HCMV infection causes retinal pathogenesis remains unresolved. Here, we report that viral immediate-early gene product 2 (IE2), but not IE1, up-regulates the Fas ligand (FasL) expression in HCMV-infected human retinal pigment epithelium cells. Increased secretion of FasL from virally infected cells into cultured medium was observed upon HCMV infection. The capability of such cell-free medium to induce apoptosis of Fas (CD95)-expressing Jurkat cells further implies that Fas-FasL interaction might mediate cell death in the lesion of HCMV retinitis. To support this idea, we observed augmented soluble FasL levels in vitreous from AIDS patients with HCMV retinitis as compared with that from AIDS patients without HCMV infection. In addition, by in situ hybridization and immunohistochemistry, we detected enhanced signals of FasL, the existence of viral IE Ags and apoptotic cells at the same sites in the lesion of HCMV-infected retina. These results strongly suggest that IE2 induction of FasL expression in human retina might be an important event that takes place in the early stage of infection and finally leads to visual loss in individuals affiliated with HCMV retinitis.

Nonsteroidal anti-inflammatory drugs for treatment of advanced gastric cancer: cyclooxygenase-2 is involved in hepatocyte growth factor mediated tumor development and progression

Surgical treatment of gastric cancer patients is dismal because advanced tumor is often noted at diagnosis. In order to obtain better adjuvant therapy for gastric cancer patients after operation, it is important to understand the mechanism of invasion and metastasis. It is well known that binding of hepatocyte growth factor (HGF) to its receptor (c-Met) regulates gastric cancer progression and metastasis. Recently, HGF was found to up-regulate the expression of cyclooxygenase-2 (COX-2) gene and increase prostaglandin (PG)synthesis in gastric mucosa cells. Over-expression of COX-2 and increased PG secretion have also been found to be involved in the growth and metastasis of gastric cancer. These results together suggest that the signaling pathway of HGF and c-Met may be mediated through ERK2 activation, up-regulation of COX-2 and increased production of PGE(2)in gastric cancer cells. In view of the fact that c-Met is over-expressed in the majority of gastric cancer patients with poor prognosis, COX-2 specific inhibitors may provide beneficial effects in these patients.

Collapsin response mediator protein-1 and the invasion and metastasis of cancer cells

BACKGROUND

Numerous genetic changes are associated with metastasis and invasion of cancer cells. To identify differentially expressed invasion-associated genes, we screened a panel of lung cancer cell lines (CL(1-0), CL(1-1), CL(1-5), and CL(1-5)-F(4) in order of increasing invasive activity) for such genes and selected one gene, collapsin response mediator protein-1 (CRMP-1), to characterize.

METHODS

We used a microarray containing 9600 gene sequences to assess gene expression in the cell panel and selected the differentially expressed CRMP-1 gene for further study. We confirmed the differential expression of CRMP-1 with northern and western blot analyses. After transfecting and overexpressing CRMP-1 in highly invasive CL(1-5) cells, the cells were assessed morphologically and with an in vitro invasion assay. We used enhanced green fluorescent protein-tagged CRMP-1 and fluorescence microscopy to localize CRMP-1 intracellularly. CRMP-1 expression in 80 lung cancer specimens was determined by real-time quantitative reverse transcription-polymerase chain reaction (RT-PCR). All statistical tests were two-sided.

RESULTS

Expression of CRMP-1 was inversely associated with invasive activity in the cell panel, an observation confirmed by northern and western blot analyses. CRMP-1-transfected CL(1-5) cells became rounded and had fewer filopodia and statistically significantly lower in vitro invasive activity than untransfected cells (all P< .001). During interphase, CRMP-1 protein was present uniformly throughout the cytoplasm and sometimes in the nucleus; during mitosis, CRMP-1 was associated with mitotic spindles, centrosomes, and the midbody (in late telophase). Real-time RT-PCR of lung cancer specimens showed that reduced expression of CRMP-1 was statistically significantly associated with advanced disease (stage III or IV; P = .010), lymph node metastasis (N1, N2, and N3; P =.043), early postoperative relapse (P = .030), and shorter survival (P = .016).

CONCLUSIONS

CRMP-1 appears to be involved in cancer invasion and metastasis and may be an invasion-suppressor gene.

2-Methoxyestradiol-induced caspase-3 activation and apoptosis occurs through G(2)/M arrest dependent and independent pathways in gastric carcinoma cells

BACKGROUND

2-Methoxyestradiol (2-Me), one of the estrogen metabolites, has recently been found to possess anti-angiogenesis activity in vivo. Many chemotherapeutic agents, such as taxol, docetaxel, and vinblastine, interact with microtubules and then induce apoptosis. It has been suggested that 2-Me acts on microtubules and results in G(2)/M-cycle arrest of tumor cells. Whether 2-Me induces apoptosis in gastric carcinoma cell lines is not known. Moreover, reactive oxygen species (ROS) produced by 2-Me may be involved in cytotoxicity of tumor cells. Thus, another objective of this study was to evaluate the relation between cell cycle arrest, ROS formation, and caspase activity levels after 2-Me treatment in gastric carcinoma cells.

METHODS

It was determined whether 2-Me directly induced apoptosis in two gastric carcinoma cell lines (SC-M1 and NUGC-3) through caspase-3 and caspase-8 activation and, eventually, induced DNA fragmentation. To clarify the effect of 2-Me-induced G(2)/M arrest in apoptosis, calcium ionophore, A23187, and thapsigargin were used to modulate 2-Me-induced cell cycle responses. Moreover, the role of 2-Me-induced ROS formation in the cell cycle responses also was evaluated.

RESULTS

It was found that 2-Me treatment resulted in G(2)/M-cycle arrest, caspase-8 and caspase-3 activation, and DNA fragmentation. In addition, the 2-Me induced, concomitant increases of peroxide and superoxide anions were correlated with G(2)/M-cycle arrest. Treatment with calcium ionophore A23187 and thapsigargin partially reversed the 2-Me-induced G(2)/M-cycle arrest, with a concomitant decrease in both peroxide and superoxide levels. Moreover, A23187 blocked the 2-Me-induced caspase-3 activation, whereas thapsigargin had no effect. Treatment with calcium channel blockers did not affect 2-Me-induced cell cycle arrest or caspase-3 activation.

CONCLUSIONS

These results suggest that the 2-Me-induced apoptosis of gastric carcinoma cells by DNA fragmentation accompanied caspase activation. Elevation of free radicals was associated with G(2)/M-cycle arrest. The induction of G(2)/M-cycle arrest is not a prerequisite for caspase activation.

Preconditioning somatothermal stimulation on right seventh intercostal nerve territory increases hepatic heat shock protein 70 and protects the liver from ischemia-reperfusion injury in rats

Hyperthermic preconditioning attenuates the heat-induced cellular response to a subsequent severe heat challenge. However, it is impractical to perform whole-body hyperthermia in humans. This study was designed to test the hypotheses that hepatic heat shock protein 70 (Hsp70) could be induced by local somatothermal stimulation (LSTS) on right seventh intercostal nerve territory and that preconditioning the rats with LSTS protects the liver from subsequent ischemia-reperfusion injury. LSTS was brought about by application of a heating rod above right seventh intercostal nerve territory in male Sprague-Dawley rats. Hepatic gene expression of Hsp70 was assessed by Western blot and reverse transcription polymerase chain reaction (RT-PCR). Finally, serum ALT and AST and the lipid peroxidation product malondialdehyde (MDA) were evaluated in ischemic-reperfused rats preconditioned by application of LSTS on right seventh intercostal nerve territory. The results showed that hepatic gene expression of Hsp70 was upregulated in rats treated with LSTS. When animals were preconditioned with LSTS, followed by subsequent ischemia-reperfusion injury of the liver, there were significant decreases in liver enzymes (ALT/AST) and MDA formation in rats pretreated with one dose of LSTS (LSTS-1 group) as compared with those not treated with LSTS (control group) or treated with three doses of LSTS (LSTS-3 group). We conclude that mild local heat stress (one dose) on right seventh intercostal nerve territory upregulates hepatic gene expression of Hsp70 and protects the liver from subsequent ischemia-reperfusion injury. This might provide an easily applicable method for those patients facing ischemia-reperfusion challenge of the liver, as in liver resection and liver transplantation.

Randomized trial of gastrojejunostomy with duodenal partition versus antrectomy in unresectable periampullary cancer

BACKGROUND

A newly-designed gastrojejunostomy with duodenal partition was hypothesized to be a relatively easier and safer gastric bypass procedure in interrupting the "food reentry", as compared with antrectomy, for patients with unresectable periampullary cancer.

METHODS

Thirty patients with unresectable periampullary malignancy were randomized to receive gastrojejunostomy with either duodenal partition or antrectomy, in addition to biliary bypass, to compare surgical risk and efficacy of the gastric bypass between these two groups.

RESULTS

Gastrojejunotomy with either duodenal partition or antrectomy could significantly shorten the gastric emptying time 6 weeks after operation. There was no significant difference between these two groups in gastric outlet obstruction (GOO) symptoms, gastric emptying time, and time for resuming oral diet intake after operation. The median operation time was shorter in the duodenal partition group (180 min) than in the antrectomy group (240 min), p < 0.01. The median blood loss was less in the duodenal partition group (250 ml) than in the antrectomy group (400 ml), (p = 0.01). Complications occurred in 3 (20%) patients with duodenal partition and in 7 (47%) patients with antrectomy, (p = 0.25). One duodenal stump leakage occurred in antrectomy group. Surgical mortality occurred in 2 patients with antrectomy.

CONCLUSIONS

Duodenal partition, with shorter operation time and less blood loss, had similar efficacy with antrectomy in correction of GOO. Therefore, duodenal partition could be a relatively easier and safer alternative to antrectomy in interrupting the "food reentry" in gastrojejunostomy for patients with unresectable periampullary cancer.

2-Methoxyestradiol-induced caspase-3 activation and apoptosis occurs through G(2)/M arrest dependent and independent pathways in gastric carcinoma cells

BACKGROUND

2-Methoxyestradiol (2-Me), one of the estrogen metabolites, has recently been found to possess anti-angiogenesis activity in vivo. Many chemotherapeutic agents, such as taxol, docetaxel, and vinblastine, interact with microtubules and then induce apoptosis. It has been suggested that 2-Me acts on microtubules and results in G(2)/M-cycle arrest of tumor cells. Whether 2-Me induces apoptosis in gastric carcinoma cell lines is not known. Moreover, reactive oxygen species (ROS) produced by 2-Me may be involved in cytotoxicity of tumor cells. Thus, another objective of this study was to evaluate the relation between cell cycle arrest, ROS formation, and caspase activity levels after 2-Me treatment in gastric carcinoma cells.

METHODS

It was determined whether 2-Me directly induced apoptosis in two gastric carcinoma cell lines (SC-M1 and NUGC-3) through caspase-3 and caspase-8 activation and, eventually, induced DNA fragmentation. To clarify the effect of 2-Me-induced G(2)/M arrest in apoptosis, calcium ionophore, A23187, and thapsigargin were used to modulate 2-Me-induced cell cycle responses. Moreover, the role of 2-Me-induced ROS formation in the cell cycle responses also was evaluated.

RESULTS

It was found that 2-Me treatment resulted in G(2)/M-cycle arrest, caspase-8 and caspase-3 activation, and DNA fragmentation. In addition, the 2-Me induced, concomitant increases of peroxide and superoxide anions were correlated with G(2)/M-cycle arrest. Treatment with calcium ionophore A23187 and thapsigargin partially reversed the 2-Me-induced G(2)/M-cycle arrest, with a concomitant decrease in both peroxide and superoxide levels. Moreover, A23187 blocked the 2-Me-induced caspase-3 activation, whereas thapsigargin had no effect. Treatment with calcium channel blockers did not affect 2-Me-induced cell cycle arrest or caspase-3 activation.

CONCLUSIONS

These results suggest that the 2-Me-induced apoptosis of gastric carcinoma cells by DNA fragmentation accompanied caspase activation. Elevation of free radicals was associated with G(2)/M-cycle arrest. The induction of G(2)/M-cycle arrest is not a prerequisite for caspase activation.

A genome-wide study of microsatellite instability in advanced gastric carcinoma

BACKGROUND

Microsatellite instability (MSI) has been described in many human carcinomas, including gastric carcinomas (GCs). There are inconsistent findings regarding the association of MSI with various subsets of GC with specific clinicopathologic features. The objective of this study was to define MSI in advanced GC at a genome-wide level and to evaluate the clinical relevance of MSI in these patients.

METHODS

Forty-one gastric adenocarcinomas with serosa invasion (T3) were analyzed at 59 loci that detected at least one site per arm of each autosome in human genome. The expression patterns of mismatch repair proteins hMLH1 and hMSH2 were examined by immunohistochemistry. Comparisons were made by categorizing tumors into three groups: tumors with MSI at multiple loci (at more than three loci), tumors with MSI at low level (at one to three loci), and microsatellite-stable (MSS) tumors. Clinical significance of MSI in advanced GC was evaluated. The relative rates of hypermutability of the 59 markers also were determined.

RESULTS

A significant association was found between tumors with MSI at multiple loci and the expanding type of tumor growth by Ming's histologic classification (P = 0.001), whereas tumors with MSI at low level and MSS tumors are clinicopathologically indistinguishable. The 59 dinucleotide repeat markers displayed varying degrees of susceptibility toward genetic instability. The relative rates of hypermutability of these markers were consistent with a normal distribution pattern in which the frequency of unstable tumors detected at different chromosomal loci varied from 0% to 20%.

CONCLUSIONS

The authors' results showed that advanced GC with MSI at multiple loci progress preferentially in an expanding mode, supporting the notion that high MSI tumors and low MSI/MSS tumors evolve through different genetic pathways. Thus, microsatellite testing may have clinical utility as a favorable prognostic marker.

A genome-wide study of microsatellite instability in advanced gastric carcinoma

BACKGROUND

Microsatellite instability (MSI) has been described in many human carcinomas, including gastric carcinomas (GCs). There are inconsistent findings regarding the association of MSI with various subsets of GC with specific clinicopathologic features. The objective of this study was to define MSI in advanced GC at a genome-wide level and to evaluate the clinical relevance of MSI in these patients.

METHODS

Forty-one gastric adenocarcinomas with serosa invasion (T3) were analyzed at 59 loci that detected at least one site per arm of each autosome in human genome. The expression patterns of mismatch repair proteins hMLH1 and hMSH2 were examined by immunohistochemistry. Comparisons were made by categorizing tumors into three groups: tumors with MSI at multiple loci (at more than three loci), tumors with MSI at low level (at one to three loci), and microsatellite-stable (MSS) tumors. Clinical significance of MSI in advanced GC was evaluated. The relative rates of hypermutability of the 59 markers also were determined.

RESULTS

A significant association was found between tumors with MSI at multiple loci and the expanding type of tumor growth by Ming's histologic classification (P = 0.001), whereas tumors with MSI at low level and MSS tumors are clinicopathologically indistinguishable. The 59 dinucleotide repeat markers displayed varying degrees of susceptibility toward genetic instability. The relative rates of hypermutability of these markers were consistent with a normal distribution pattern in which the frequency of unstable tumors detected at different chromosomal loci varied from 0% to 20%.

CONCLUSIONS

The authors' results showed that advanced GC with MSI at multiple loci progress preferentially in an expanding mode, supporting the notion that high MSI tumors and low MSI/MSS tumors evolve through different genetic pathways. Thus, microsatellite testing may have clinical utility as a favorable prognostic marker.

Peptoid oligomers with alpha-chiral, aromatic side chains: sequence requirements for the formation of stable peptoid helices

The achiral backbone of oligo-N-substituted glycines or "peptoids" lacks hydrogen-bond donors, effectively preventing formation of the regular, intrachain hydrogen bonds that stabilize peptide alpha-helical structures. Yet, when peptoids are N-substituted with alpha-chiral, aromatic side chains, oligomers with as few as five residues form stable, chiral, polyproline-like helices in either organic or aqueous solution. The adoption of chiral secondary structure in peptoid oligomers is primarily driven by the steric influence of these bulky, chiral side chains. Interestingly, peptoid helices of this class exhibit intense circular dichroism (CD) spectra that closely resemble those of peptide alpha-helices. Here, we have taken advantage of this distinctive spectroscopic signature to investigate sequence-related factors that favor and disfavor stable formation of peptoid helices of this class, through a comparison of more than 30 different heterooligomers with mixed chiral and achiral side chains. For this family of peptoids, we observe that a composition of at least 50% alpha-chiral, aromatic residues is necessary for the formation of stable helical structure in hexameric sequences. Moreover, both CD and 1H-13C HSQC NMR studies reveal that these short peptoid helices are stabilized by the placement of an alpha-chiral, aromatic residue on the carboxy terminus. Additional stabilization can be provided by the presence of an "aromatic face" on the helix, which can be patterned by positioning aromatic residues with three-fold periodicity in the sequence. Extending heterooligomer chain length beyond 12-15 residues minimizes the impact of the placement, but not the percentage, of alpha-chiral aromatic side chains on overall helical stability. In light of these new data, we discuss implications for the design of helical, biomimetic peptoids based on this structural motif.

A genome-wide study of microsatellite instability in advanced gastric carcinoma

BACKGROUND

Microsatellite instability (MSI) has been described in many human carcinomas, including gastric carcinomas (GCs). There are inconsistent findings regarding the association of MSI with various subsets of GC with specific clinicopathologic features. The objective of this study was to define MSI in advanced GC at a genome-wide level and to evaluate the clinical relevance of MSI in these patients.

METHODS

Forty-one gastric adenocarcinomas with serosa invasion (T3) were analyzed at 59 loci that detected at least one site per arm of each autosome in human genome. The expression patterns of mismatch repair proteins hMLH1 and hMSH2 were examined by immunohistochemistry. Comparisons were made by categorizing tumors into three groups: tumors with MSI at multiple loci (at more than three loci), tumors with MSI at low level (at one to three loci), and microsatellite-stable (MSS) tumors. Clinical significance of MSI in advanced GC was evaluated. The relative rates of hypermutability of the 59 markers also were determined.

RESULTS

A significant association was found between tumors with MSI at multiple loci and the expanding type of tumor growth by Ming's histologic classification (P = 0.001), whereas tumors with MSI at low level and MSS tumors are clinicopathologically indistinguishable. The 59 dinucleotide repeat markers displayed varying degrees of susceptibility toward genetic instability. The relative rates of hypermutability of these markers were consistent with a normal distribution pattern in which the frequency of unstable tumors detected at different chromosomal loci varied from 0% to 20%.

CONCLUSIONS

The authors' results showed that advanced GC with MSI at multiple loci progress preferentially in an expanding mode, supporting the notion that high MSI tumors and low MSI/MSS tumors evolve through different genetic pathways. Thus, microsatellite testing may have clinical utility as a favorable prognostic marker.

Electrogastrographic characteristics in patients of stomach cancer

Using a homemade electrogastrography (EGG) system, we studied the characteristics of myoelectrical rhythm in gastric cancer (GC) patients. Based on a short-term Fourier transform, recorded slow waves could be automatically analyzed to obtain the following parameters: dominant frequency/power, percent of normal rhythm (2.4-3.7 cpm), power ratio, etc. Fifty histologically confirmed GC patients (34 men, 16 women) were enrolled before surgical intervention to measure their fasting and postprandial EGG parameters for 30 min. The cancerous parameters of GC patients were then obtained postoperatively. In addition, 46 healthy subjects were enrolled for comparison. When compared to controls, GC patients had the following characteristics: absence of postprandial increase in dominant frequency (GC: 3.04 +/- 0.47 vs 3.07 +/- 0.44 cpm, NS; controls: 3.02 +/- 0.31 vs 3.21 +/- 0.25 cpm, P < 0.001), marked power response after meal (P < 0.05), and obvious power ratio (4.58 +/- 7.38 vs 2.27 +/- 2.05, P < 0.05). Multivariate analysis indicated that advanced GC was the factor responsible for the obvious dominant power enhancement after meal (P < 0.05). Other demographic, clinical, and cancerous factors did not influence EGG parameters. We conclude that apparent arrhythmia is not encountered in GC patients, although they mainly exhibit obvious postprandial power response. Advanced GC is likely responsible for this power enhancement on EGG recording.

Clinicopathologic and prognostic differences between patients with hepatitis B- and C-related resectable hepatocellular carcinoma

BACKGROUND AND PURPOSE

Hepatitis B and C viral infections are important factors in the development of hepatocellular carcinoma (HCC). This study examined the clinicopathologic and prognostic differences in patients with hepatitis B- and C-related resectable HCC.

METHODS

A total of 270 HCC patients who underwent hepatic resection were enrolled. Among these patients, 211 were positive for hepatitis B surface antigen (HBsAg) and 59 were positive for anti-hepatitis C virus antibody (anti-HCV). The clinical manifestations, pathologic features, and treatment outcomes were compared between the HBsAg-positive and anti-HCV-positive groups.

RESULTS

Compared to anti-HCV-positive patients, HBsAg-positive patients were significantly younger, had a higher familial incidence of HCC, larger tumor size, and a higher incidence of multiple tumors. HCC patients who were anti-HCV positive had worse liver function and a higher incidence of history of blood transfusion. DNA flow cytometric analysis revealed significantly more proliferative activity in the non-tumor part of the liver in HBsAg-positive HCC patients. The 1-, 3-, and 5-year overall survival rates of HBsAg-positive patients were 79%, 57%, and 48%, respectively, and for anti-HCV-positive patients were 91%, 75%, and 62%, respectively. HBsAg-positive patients had a significantly lower overall survival rate than anti-HCV-positive patients (p = 0.018).

CONCLUSIONS

HBsAg-positive patients with resectable HCC had a less favorable survival rate after tumor resection than anti-HCV-positive HCC patients. This survival difference might have been related to the relatively advanced stage of disease and the higher proliferative activity of the non-tumor part of the liver in HBsAg-positive HCC patients.

Global analysis of gene expression in invasion by a lung cancer model

Metastasis is a complicated multistep process that involves interactions between cancer cells and their surrounding microenvironments. Previously, we have established a series of lung adenocarcinoma cell lines with varying degrees of invasiveness. Tracheal graft assay confirmed that cell lines with higher in vitro invasiveness had greater in vivo invasive potential. In this study, we used these model cell lines to identify invasion-associated genes using cDNA microarray with colorimetric detection. A more invasive subline, CL 1-5-F 4, derived from metastatic lung tumor of severe combined immunodeficient mice inoculated with CL 1-5 cells, was combined with CL 1-0, CL 1-1, and CL 1-5 in cDNA microarray screening. cDNA microarray membranes, each containing 9600 nonredundant expressed sequence tag clones, were used to identify differentially expressed genes in these cell lines. For statistical analysis, self-organizing map algorithm was performed to identify the expression patterns. Positive correlation between gene expression levels and cell line invasiveness was found in 2.9% of the 9600 putative genes. On the other hand, negative correlation was found in 3.3% of the genes. The trends of expression of some of the genes were also confirmed by Northern hybridization and flow cytometry. Our data demonstrated that genes related to cell adhesion, motility, angiogenesis, signal transduction, and some other expressed sequence tag genes may play significant roles in the metastasis process. These results substantiate the model system with which one can identify invasion-associated genes by using cDNA microarray and cancer cell lines of different invasiveness. This technique may allow us to explore complex interactions between multiple genes that orchestrate the process of cancer metastasis.

Mechanisms of inactivation of E-cadherin in breast carcinoma: modification of the two-hit hypothesis of tumor suppressor gene

Loss of heterozygosity (LOH) allows the expression of recessive mutation in tumor suppressor genes (TSG). Therefore, on the basis of Knudson's 'two-hit' hypothesis for TSG inactivation, the detection of a high LOH frequency in a chromosomal region is considered critical for TSG localization. One of these LOH regions in breast cancer is 16q22.1, which has been suggested to reflect the involvement of E-cadherin (E-cad), a cell-cell adhesion molecule. To confirm the tumorigenic role of E-cad, 81 sporadic invasive ductal carcinomas (IDCs) of the breast were tested for the 'two hits' required to inactivate this gene. A high frequency (37.3%) of LOH was detected in 67 informative tumors, but no mutation was found. To examine the possibility that transcriptional mechanisms serve as the second hit in tumors with LOH, specific pathways, including genetic variant and hypermethylation at the promoter region and abnormal expression of positive (WT1) and negative (Snail) transcription factors, were identified. Of these, promoter hypermethylation and increased expression of Snail were found to be common (>35%), and to be strongly associated with reduced/negative E-cad expression (P<0.05). However, unexpectedly, a significantly negative association was found between the existence of LOH and promoter hypermethylation (P<0.05), which contradicts the 'two-hit' model. Instead, since they coexisted in a high frequency of tumors, hypermethylation may work in concert with increased Snail to inactivate E-cad expression. Given that E-cad is involved in diverse mechanisms, loss of which is beneficial for tumors to invade but may also trigger apoptosis, this study suggests that maintaining a reversible mechanism, either by controlling the gene at the transcriptional level or by retaining an intact allele subsequent to LOH, might be important for E-cad in IDC and may also be common in TSGs possessing diverse functions. These findings provide clues to explain why certain TSGs identified by LOH cannot fulfil the two-hit hypothesis.

Utilization of Drosophila eye to probe the functions of two mammalian serine/threonine kinases, Snk and HsHPK

Here we report a quick functional analysis of two mammalian serine/threonine kinases, a serum inducible kinase (Snk) and Homo sapiens hepatoma protein kinase (HsHPK), using Drosophila eye as a model system. We generated transgenic fly lines carrying constructs of both kinases under control of the GAL upstream activating sequence (UAS). Each UAS line was then crossed to a line in which GAL4 expression was driven by one of the following promoters, eyeless (ey), glass or decapentaplegic. Thus, different kinase mutants can be ectopically expressed in a promoter-dependent manner. We observed that the ectopic expression of either the wild-type or active form of Snk driven by the glass promoter resulted in a rough-eye phenotype. Nevertheless, the ectopic expression of HsHPK under the control of the ey promoter resulted in a small-eye phenotype. The results of this study demonstrated that ectopic expression of these two mammalian genes could be achieved by the regulation of Drosophila promoters. In addition, the effects of these ectopically expressed genes on eye development could be an implication of their functions with respect to cell proliferation and differentiation. Thus, Drosophila eye, with the powerful genetic tools and vast information on eye development available, can be a useful system to probe the functions of mammalian genes in the postgenome era.

Ischaemic change of the human intestine after total portal occlusion during liver resection

This is a clinical study of the use of several monitoring techniques to evaluate the effect of total hepatic inflow occlusion on intestinal ischaemia during liver resection. A total of 8 patients was studied. Parameters measured included intestinal oxygen extraction ratio, portal venous and arterial lactate levels and intestinal intramucosal pH (pHi), measured by an intraluminal tonometer. When venous outflow of the intestine was occluded, intestinal oxygen extraction ratio increased and portal venous lactate increased significantly, but arterial lactate did not increase significantly until after 60 minutes of occlusion. Intestinal pHi decreased significantly after 60 minutes. Following release of the occlusion, oxygen extraction and pHi returned to normal in 7 out of 8 patients. The 1 patient who had a persistent decrease in pHi died postoperatively. These findings indicate that a marked drop in pHi after total portal occlusion and persistent low pHi following the release of a portal occlusion are associated with the development of complications and mortality during liver resection.