Search tips
Search criteria

Results 1-25 (34)

Clipboard (0)

Select a Filter Below

Year of Publication
more »
1.  Identification of a Potential Target of Capsaicin by Computational Target Fishing 
Capsaicin, the component responsible for the pungency of chili peppers, shows beneficial effects in many diseases, although the underlying mechanisms remain unclear. In the present study, the potential targets of capsaicin were predicted using PharmMapper and confirmed via chemical-protein interactome (CPI) and molecular docking. Carbonic anhydrase 2 was identified as the main disease-related target, with the pharmacophore model matching well with the molecular features of capsaicin. The relation was confirmed by CPI and molecular docking and supported by previous research showing that capsaicin is a potent inhibitor of carbonic anhydrase isoenzymes. The present study provides a basis for understanding the mechanisms of action of capsaicin or those of other natural compounds.
PMCID: PMC4681817  PMID: 26770256
2.  Descending Control of Itch Transmission by the Serotonergic System via 5-HT1A-Facilitated GRP-GRPR Signaling 
Neuron  2014;84(4):821-834.
Central serotonin (5-HT) modulates somatosensory transduction, but how it achieves sensory modality-specific modulation remains unclear. Here we report that enhancing serotonergic tone via administration of 5-hydroxytryptophan potentiates itch sensation, whereas mice lacking 5-HT or serotonergic neurons in the brainstem exhibit markedly reduced scratching behavior. Through pharmacological and behavioral screening, we identified 5-HT1A as a key receptor in facilitating gastrin-releasing peptide (GRP)-dependent scratching behavior. Co-activation of 5-HT1A and GRP receptors (GRPR) greatly potentiates subthreshold, GRP-induced Ca2+ transients and action potential firing of GRPR+ neurons. Immunostaining, biochemical and biophysical studies suggest that 5-HT1A and GRPR may function as receptor heteromeric complexes. Furthermore, 5-HT1A blockade significantly attenuates, whereas its activation contributes to, long-lasting itch transmission. Thus, our studies demonstrate that the descending 5-HT system facilitates GRP-GRPR signaling via 5-HT1A to augment itch-specific outputs and a disruption of crosstalk between 5-HT1A and GRPR may be a useful anti-pruritic strategy.
PMCID: PMC4254557  PMID: 25453842
3.  Proposal for fabrication-tolerant SOI polarization splitter-rotator based on cascaded MMI couplers and an assisted bi-level taper 
Optics Express  2014;22(23):27869-27879.
A novel silicon-on-insulator (SOI) polarization splitter-rotator (PSR) with a large fabrication tolerance is proposed based on cascaded multimode interference (MMI) couplers and an assisted mode-evolution taper. The tapers are designed to adiabatically convert the input TM0 mode into the TE1 mode, which will output as the TE0 mode after processed by the subsequent MMI mode converter, 90-degree phase shifter (PS) and MMI 3 dB coupler. The numerical simulation results show that the proposed device has a < 0.5 dB insertion loss with < −17 dB crosstalk in C optical communication band. Fabrication tolerance analysis is also performed with respect to the deviations of MMI coupler width, PS width, slab height and upper-cladding refractive index, showing that this device could work well even when affected by considerable fabrication errors. With such a robust performance with a large bandwidth, this device offers potential applications for CMOS-compatible polarization diversity, especially in the booming 100 Gb/s coherent optical communications based on silicon photonics technology.
PMCID: PMC4314382  PMID: 25402029
(130.3120) Integrated optics devices; (230.7370) Waveguides; (130.5440) Polarization-selective devices
4.  Evidence that TP_0144 of Treponema pallidum Is a Thiamine-Binding Protein 
Journal of Bacteriology  2015;197(7):1164-1172.
Thiamine pyrophosphate (TPP), the biologically active form of thiamine (also known as vitamin B1), is an essential cofactor for several important enzymes involved in carbohydrate metabolism, and therefore, it is required for all living organisms. We recently found that a thiamine-binding protein (TDE_0143) is essential for the survival of Treponema denticola, an important bacterial pathogen that is associated with human periodontitis. In this report, we provide experimental evidence showing that TP_0144, a homolog of TDE_0143 from the syphilis spirochete Treponema pallidum, is a thiamine-binding protein that has biochemical features and functions that are similar to those of TDE_0143. First, structural modeling analysis reveal that both TDE_0143 and TP_0144 contain a conserved TPP-binding site and share similar structures to the thiamine-binding protein of Escherichia coli. Second, biochemical analysis shows that these two proteins bind to TPP with similar dissociation constant (Kd) values (TDE_0143, Kd of 36.50 nM; TP_0144, Kd of 32.62 nM). Finally, heterologous expression of TP_0144 in a ΔTDE_0143 strain, a previously constructed TDE_0143 mutant of T. denticola, fully restores its growth and TPP uptake when exogenous thiamine is limited. Collectively, these results indicate that TP_0144 is a thiamine-binding protein that is indispensable for T. pallidum to acquire exogenous thiamine, a key nutrient for bacterial survival. In addition, the studies shown in this report further underscore the feasibility of using T. denticola as a platform to study the biology and pathogenicity of T. pallidum and probably other uncultivable treponemal species as well.
PMCID: PMC4352656  PMID: 25605310
5.  Effectiveness of the live attenuated rotavirus vaccine produced by a domestic manufacturer in China studied using a population-based case–control design 
A universal rotavirus (RV) immunization program is a potentially cost-effective measure for preventing RV infection in China. However, the efficacy of the only licensed RV vaccine (Lanzhou lamb rotavirus vaccine, LLR), which is made by a domestic manufacturer, has not been proven by a properly designed clinical trial. In October 2011 to March 2012, to measure the potential protection provided by LLR, a case–control study nested in a population-based active diarrhea surveillance study of children <5 years of age was conducted in rural Zhengding county. During the study period, 308 episodes of diarrhea were identified as being caused by RV infection, resulting in an incidence rate of 48.0/1000 people/year. The predominant RV serotype was G3 (61.5%), followed by G1 (15.2%), and G9 (6.5%). Overall, a protection of 35.0% (95% confidence interval (CI), 13.0%–52.0%) was identified, and higher protection was found among moderate RV gastroenteritis cases caused by the serotype G3 (52.0% 95% CI: 2.0%–76.1%). A concurrently conducted case–control study comparing non-RV viral diarrheal cases with non-diarrheal controls in the same population found that the RV vaccine offered no protection against non-RV diarrhea. Even under a less ideal immunization schedule, the oral LLR conferred a certain level of protection against RV gastroenteritis. However, further studies are needed to understand the full characteristics of the LLR, including its efficacy when administered following the optimal regimen, the potential risk of inducing intussusception, and the direct and indirect protective effects of LLR.
PMCID: PMC4631931  PMID: 26576341
attenuated vaccine; case–control study; China; effectiveness; rotavirus
6.  Reconfigurable radio-frequency arbitrary waveforms synthesized in a silicon photonic chip 
Nature Communications  2015;6:5957.
Photonic methods of radio-frequency waveform generation and processing can provide performance advantages and flexibility over electronic methods due to the ultrawide bandwidth offered by the optical carriers. However, bulk optics implementations suffer from the lack of integration and slow reconfiguration speed. Here we propose an architecture of integrated photonic radio-frequency generation and processing and implement it on a silicon chip fabricated in a semiconductor manufacturing foundry. Our device can generate programmable radio-frequency bursts or continuous waveforms with only the light source, electrical drives/controls and detectors being off-chip. It modulates an individual pulse in a radio-frequency burst within 4 ns, achieving a reconfiguration speed three orders of magnitude faster than thermal tuning. The on-chip optical delay elements offer an integrated approach to accurately manipulating individual radio-frequency waveform features without constraints set by the speed and timing jitter of electronics, and should find applications ranging from high-speed wireless to defence electronics.
Performing radio-frequency arbitrary waveform generation in the optical domain offers advantages over electronic-based methods but suffers from lack of integration and slow speed. Here, Wang et al. propose a fast-reconfigurable, radio-frequency arbitrary waveform generator fully integrated in a silicon chip.
PMCID: PMC4354206  PMID: 25581847
7.  Live attenuated hepatitis A vaccines developed in China 
Two live, attenuated hepatitis A vaccines, H2 and LA-1 virus strains, were developed through serial passages of the viruses in cell cultures at 32 °C and 35 °C respectively. Both vaccines were safe and immunogenic, providing protection against clinical hepatitis A in 95% of the vaccinees, with a single dose by subcutaneous injection. The vaccine recipients were not protected from asymptomatic, subclinical hepatitis A virus (HAV) infection, which induced a similar antibody response as for unvaccinated subjects. A second dose caused anamnestic response and can be used for boosting. Oral immunization of human with H2 vaccine or of marmoset with LA-1 vaccine failed, and no evidence was found for person-to-person transmission of H2 strain or for marmoset-to-marmoset transmission of LA-1 strain by close contact. H2 strain was genetically stable when passaged in marmosets, humans or cell cultures at 37 °C; 3 consecutive passages of the virus in marmosets did not cause virulence mutation. The live vaccines offer the benefits of low cost, single dose injection, long- term protection, and increased duration of immunity through subclinical infection. Improved sanitation and administration of 150 million doses of the live vaccines to children had led to a 90% reduction in the annual national incidence rate of hepatitis A in China during the 16-year period, from 1991 to 2006. Hepatitis A (HA) immunization with both live and inactivated HA vaccines was implemented in the national routine childhood immunization program in 2008 and around 92% of the 16 million annual births received the affordable live, attenuated vaccines at 18 months of age. Near elimination of the disease was achieved in a county of China for 14 years following introduction of the H2 live vaccine into the Expanded Immunization Program (EPI) in 1992.
PMCID: PMC4130259  PMID: 24280971
hepatitis A; live attenuated; vaccine; immunization; China
8.  Quantitative Measurement of Organic Acids in Tissues from Gastric Cancer Patients Indicates Increased Glucose Metabolism in Gastric Cancer 
PLoS ONE  2014;9(6):e98581.
The levels of organic acids representing metabolic pathway end products are important indicators of physiological status, and may be associated with metabolic changes in cancer. The aim of this study is to investigate the levels of organic acids in cancerous and normal tissues from gastric cancer patients and to confirm the role of metabolic alterations in gastric carcinogenesis. Organic acids in normal and cancerous tissues from forty-five patients with gastric adenocarcinoma were investigated by gas chromatography-mass spectrometry in selected ion monitoring mode as methoxime/tert-butyldimethylsilyl derivatives. We analysed the significant differences in the levels of organic acids in normal and cancer tissues and investigated the correlation of these levels in cancer tissues with clinicopathological features. The levels of Krebs cycle components, including α-ketoglutaric acid, succinic acid, fumaric acid, malic acid and oxaloacetic acid, were significantly increased in cancer tissues compared to normal tissues. In addition, the levels of glycolytic products, including pyruvic acid and lactic acid, as well as the levels of ketone bodies, including 3-hydroxybutyric acid, were also significantly increased in cancer tissues compared to normal tissues. The levels of ketone bodies in cancer tissues with differentiated histology and in intestinal-type cancer tissues were significantly increased. The organic acid profiling analysis described here may be a generally useful clinical tool for understanding the complexity of metabolic events in gastric adenocarcinoma, and organic acids may have potential as metabolic markers for the future discovery of diagnostic and therapeutic modalities.
PMCID: PMC4049586  PMID: 24911788
9.  Diversity of Rotavirus Strains Causing Diarrhea in <5 Years Old Chinese Children: A Systematic Review 
PLoS ONE  2014;9(1):e84699.
We conducted a systematic review of the diversity and fluctuation of group A rotavirus strains circulating in China.
Methods and Findings
Studies of rotavirus-based diarrhea among children less than 5 years, published in English or Chinese between 1994 and 2012, were searched in PubMed, SinoMed, and CNKI and reviewed by applying standardized algorithms. The temporal and spatial trends of genotyping and serotyping were analyzed using a random-effects model. Ninety-three studies met the inclusion/exclusion criteria and were included in the meta-analysis. Overall, 22,112 and 10,660 rotavirus samples had been examined for G and P types, respectively. The most common G types were G1 (39·5%), G3 (35·6%), G2 (1·3%), and G9 (0·1%). Among P types, P[8] (54·6%) was the predominant type, followed by P[4] (11·1%) and P6 (0·1%). The most common G-P combinations were G3P[8] (32·1%) and G1P[8] (24·5%), followed by G2P[6] (13·2%) and G2P[4] (10·1%). Before 2000, serotype G1 was the predominant strain and accounted for 74·3% of all rotavirus infections; however, since 2000, G3 (45·2%) has been the predominant strain. Rotavirus P types showed little variation over the study period.
Despite the variation of serotypes observed in China, the G1, G2, G3, and G4 serotypes accounted for most rotavirus strains in recent decades. These results suggest that Chinese children will be adequately protected with currently available or forthcoming rotavirus vaccines.
PMCID: PMC3885581  PMID: 24416267
10.  Identification of New Proteins That Modulate the Germination of Spores of Bacillus Species 
Journal of Bacteriology  2013;195(13):3009-3021.
A number of operons encoding the nutrient germinant receptors (GRs) in dormant spores of Bacillus megaterium and Bacillus subtilis species have small open reading frames (ORFs) of unknown function within or immediately adjacent to the operons. Inactivation of the genes in these ORFs, encoding proteins now termed D proteins, either significantly increased or decreased spore germination via the associated GR but had no effects on germination via non-GR-dependent germinants. These effects on GR-dependent germination were complemented by ectopic expression of the appropriate D gene (gene encoding D protein). However, substitution of noncognate D genes in two GR operons resulted in inhibition of germination via the GR manipulated, although ectopic overexpression of a D gene had no effect on overall GR-dependent germination. The various D genes studied were expressed in the forespore during sporulation in parallel with the associated GR operon, and transcription of a B. subtilis D gene was controlled by RNA polymerase sigma factor σG. These results indicate that proteins encoded by small ORFs within or adjacent to operons encoding GRs play major roles in modulating GR function in spores of Bacillus species. In B. subtilis, deletion of a D gene (B. subtilis gerKD [gerKDbs]) adjacent to the gerK operon encoding the GerK GR or ectopic expression or overexpression of gerKDbs had no major effect on the levels of GR subunits or of two other germination proteins.
PMCID: PMC3697528  PMID: 23625846
11.  Paradoxical potentiation of methylene blue-mediated antimicrobial photodynamic inactivation by sodium azide: Role of ambient oxygen and azide radicals 
Free radical biology & medicine  2012;53(11):2062-2071.
Sodium azide (NaN3) is widely employed to quench singlet oxygen during photodynamic therapy (PDT), especially when PDT is used to kill bacteria in suspension. We observed that addition of NaN3 (100 μM or 10 mM) to gram-positive Staphylococcus aureus and gram-negative Escherichia coli incubated with methylene blue (MB) and illuminated with red light gave significantly increased bacterial killing (1–3 logs), rather than the expected protection from killing. A different antibacterial photosensitizer, the conjugate between polyethylenimine and chlorin(e6) (PEI-ce6), showed reduced PDT killing (1–2 logs) after addition of 10 mM NaN3. Azide (0.5 mM) potentiated bacterial killing by Fenton reagent (hydrogen peroxide and ferrous sulfate) by up to 3 logs, but protected against killing mediated by sodium hypochlorite and hydrogen peroxide (considered to be a chemical source of singlet oxygen). The intermediacy of N3• was confirmed by spin-trapping and electron spin resonance studies in both MB-photosensitized reactions and Fenton reagent with addition of NaN3. We found that N3• was formed and bacteria were killed even in the absence of oxygen, suggesting the direct one-electron oxidation of azide anion by photoexcited MB. This observation suggests a possible mechanism to carry out oxygen-independent PDT.
PMCID: PMC3522421  PMID: 23044264
Sodium azide; Antimicrobial photodynamic therapy (APDT); Hydroxyl radical; Single oxygen; Azidyl radical
12.  Methylenetetrahydrofolate reductase C677T gene polymorphism and colorectal cancer risk: A case-control study 
Oncology Letters  2012;4(2):365-369.
We designed a case-control study to determine the plasma homocysteine (Hcy) level and evaluate the potential role of the methylenetetrahydrofolate reductase (MTHFR) C677T gene polymorphism in colorectal cancer (CRC). Total Hcy was quantified using the fluorescence polarization immunoassay (FPIA) on the IMx analyzer. Genomic DNA was analyzed by the real-time polymerase chain reaction (RT-PCR). The plasma levels of Hcy in the CRC group (12.63±3.11 μmol/l) were significantly higher compared with those in the control group (10.87±2.42 μmol/l; P<0.05). The frequency of the MTHFR 677TT genotype in CRC patients was markedly high. The MTHFR 677TT genotype was significantly correlated with an increased risk of CRC (odds ratio, 1.671; 95% confidence interval, 1.094–2.553; P=0.018). This study suggests that the MTHFR C677T polymorphism indicates susceptibility to CRC and is correlated with CRC pathogenesis, suggesting that the homozygous variant MTHFR C677T polymorphism is a candidate risk factor for CRC.
PMCID: PMC3402734  PMID: 22844384
methylenetetrahydrofolate reductase; polymorphism; homocysteine; colorectal cancer
13.  Type I and Type II mechanisms of antimicrobial photodynamic therapy: An in vitro study on Gram-negative and Gram-positive bacteria 
Lasers in surgery and medicine  2012;44(6):490-499.
Background and Objectives
Antimicrobial photodynamic therapy (APDT) employs a nontoxic photosensitizer (PS) and visible light, which in the presence of oxygen produce reactive oxygen species (ROS), such as singlet oxygen (1O2, produced via Type II mechanism) and hydroxyl radical (HO•, produced via Type I mechanism). This study examined the relative contributions of 1O2 and HO• to APDT killing of Gram-positive and Gram-negative bacteria.
Study Design/Materials and Methods
Fluorescence probes, 3'-(p-hydroxyphenyl)-fluorescein (HPF) and singlet oxygen sensor green reagent (SOSG) were used to determine HO• and 1O2 produced by illumination of two PS: tris-cationic-buckminsterfullerene (BB6) and a conjugate between polyethylenimine and chlorin(e6) (PEI–ce6). Dimethylthiourea is a HO• scavenger, while sodium azide (NaN3) is a quencher of 1O2. Both APDT and killing by Fenton reaction (chemical generation of HO•) were carried out on Gram-positive bacteria (Staphylococcus aureus and Enteroccoccus fecalis) and Gram-negative bacteria (Escherichia coli, Proteus mirabilis and Pseudomonas aeruginosa.
Conjugate PEI-ce6 mainly produced 1O2 (quenched by NaN3), while BB6 produced HO• in addition to 1O2 when NaN3 potentiated probe activation. NaN3 also potentiated HPF activation by Fenton reagent. All bacteria were killed by Fenton reagent but Gram-positive bacteria needed a higher concentration than Gram-negatives. NaN3 potentiated Fenton-mediated killing of all bacteria. The ratio of APDT killing between Gram-positive and Gram-negative bacteria was 2 or 4:1 for BB6 and 25:1 for conjugate PEI-ce6. There was a NaN3 dose dependent inhibition of APDT killing using both PEI-ce6 and BB6 against Gram-negative bacteria while NaN3 almost failed to inhibit killing of Gram-positive bacteria.
Azidyl radicals may be formed from NaN3 and HO•. It may be that Gram-negative bacteria are more susceptible to HO• while Gram-positive bacteria are more susceptible to 1O2. The differences in NaN3 inhibition may reflect differences in the extent of PS binding to bacteria (microenvironment) or differences in penetration of NaN3 into cell walls of bacteria.
PMCID: PMC3428129  PMID: 22760848
antimicrobial photodynamic inactivation; singlet oxygen; hydroxyl radical; sodium azide; Gram-positive and Gram-negative bacteria; antimicrobial photodynamic therapy; polyethylenimine chlorin(e6) conjugate; tris-cationic fullerene; singlet oxygen; hydroxyl radical; sodium azide
14.  Outcomes of Critical Pathway in Laparoscopic and Open Surgical Treatments for Gastric Cancer Patients: Patients Selection for Fast-Track Program through Retrospective Analysis 
Journal of Gastric Cancer  2013;13(2):98-105.
The aim of this study is to investigate the clinical factors affecting on the cure rate by invasive and open surgery for gastric cancer and to establish a subgroup of patients who can be applied by the early recovery after surgery program through this retrospective analysis.
Materials and Methods
In this retrospective study, we analyzed 425 patients who underwent gastric cancer surgery between January 2011 and December 2011 and were managed with conventional clinical therapies. This clinical algorithm was made when the patient was in minimally invasive surgery group and discharged from hospital one day faster than them in open surgery group.
The completion rate of the clinical pathway was 62.4%. Despite the different applications of clinical pathway, completion rate in minimally invasive surgery group was significantly higher than that of open group (P<0.001). In multivariate analysis, the surgical procedure of minimally invasive surgery (odds ratio=4.281) was the most predictable factor to complete clinical pathway. Additionally, younger patients (odds ratio=1.933) who underwent distal gastrectomy (odds ratio=1.999) without combined resection (odds ratio=3.069) were predicted to accomplish the clinical pathway without any modifications.
We concluded that high efficacy of the clinical pathway for gastric cancer surgery was expected to selected patients through retrospective analysis (expected completion rate=85.4%). In addition, these patients would become enrolled criteria for early recovery program in gastric cancer surgery.
PMCID: PMC3705139  PMID: 23844324
Stomach neoplasms; Critical pathways; Gastrectomy; Minimally invasive
15.  Analysis of the Effects of a gerP Mutation on the Germination of Spores of Bacillus subtilis 
Journal of Bacteriology  2012;194(21):5749-5758.
As previously reported, gerP Bacillus subtilis spores were defective in nutrient germination triggered via various germinant receptors (GRs), and the defect was eliminated by severe spore coat defects. The gerP spores' GR-dependent germination had a longer lag time between addition of germinants and initiation of rapid release of spores' dipicolinic acid (DPA), but times for release of >90% of DPA from individual spores were identical for wild-type and gerP spores. The gerP spores were also defective in GR-independent germination by DPA with its associated Ca2+ divalent cation (CaDPA) but germinated better than wild-type spores with the GR-independent germinant dodecylamine. The gerP spores exhibited no increased sensitivity to hypochlorite, suggesting that these spores have no significant coat defect. Overexpression of GRs in gerP spores did lead to faster germination via the overexpressed GR, but this was still slower than germination of comparable gerP+ spores. Unlike wild-type spores, for which maximal nutrient germinant concentrations were between 500 μM and 2 mM for l-alanine and ≤10 mM for l-valine, rates of gerP spore germination increased up to between 200 mM and 1 M l-alanine and 100 mM l-valine, and at 1 M l-alanine, the rates of germination of wild-type and gerP spores with or without all alanine racemases were almost identical. A high pressure of 150 MPa that triggers spore germination by activating GRs also triggered germination of wild-type and gerP spores identically. All these results support the suggestion that GerP proteins facilitate access of nutrient germinants to their cognate GRs in spores' inner membrane.
PMCID: PMC3486119  PMID: 22904285
16.  Transcranial Low-Level Laser Therapy Improves Neurological Performance in Traumatic Brain Injury in Mice: Effect of Treatment Repetition Regimen 
PLoS ONE  2013;8(1):e53454.
Low-level laser (light) therapy (LLLT) has been clinically applied around the world for a spectrum of disorders requiring healing, regeneration and prevention of tissue death. One area that is attracting growing interest in this scope is the use of transcranial LLLT to treat stroke and traumatic brain injury (TBI). We developed a mouse model of severe TBI induced by controlled cortical impact and explored the effect of different treatment schedules. Adult male BALB/c mice were divided into 3 broad groups (a) sham-TBI sham-treatment, (b) real-TBI sham-treatment, and (c) real-TBI active-treatment. Mice received active-treatment (transcranial LLLT by continuous wave 810 nm laser, 25 mW/cm2, 18 J/cm2, spot diameter 1 cm) while sham-treatment was immobilization only, delivered either as a single treatment at 4 hours post TBI, as 3 daily treatments commencing at 4 hours post TBI or as 14 daily treatments. Mice were sacrificed at 0, 4, 7, 14 and 28 days post-TBI for histology or histomorphometry, and injected with bromodeoxyuridine (BrdU) at days 21–27 to allow identification of proliferating cells. Mice with severe TBI treated with 1-laser Tx (and to a greater extent 3-laser Tx) had significant improvements in neurological severity score (NSS), and wire-grip and motion test (WGMT). However 14-laser Tx provided no benefit over TBI-sham control. Mice receiving 1- and 3-laser Tx had smaller lesion size at 28-days (although the size increased over 4 weeks in all TBI-groups) and less Fluoro-Jade staining for degenerating neurons (at 14 days) than in TBI control and 14-laser Tx groups. There were more BrdU-positive cells in the lesion in 1- and 3-laser groups suggesting LLLT may increase neurogenesis. Transcranial NIR laser may provide benefit in cases of acute TBI provided the optimum treatment regimen is employed.
PMCID: PMC3538543  PMID: 23308226
17.  Expression of pyruvate dehydrogenase kinase-1 in gastric cancer as a potential therapeutic target 
In contrast to mitochondria in healthy cells, which utilize oxidative phosphorylation, malignant cells undergo elevated glycolysis for energy production using glucose. The objectives of this study were to evaluate whether the expression of various molecules, including pyruvate dehydrogenase kinase-1 (PDK-1), is involved in the altered glucose metabolism associated with gastric cancer prognosis and to assess the role of a therapeutic agent in targeting glucose metabolism in gastric cancer. Immunohistochemistry was performed on gastric cancer tissues obtained from 152 patients who underwent curative resection to assess the expression of hypoxia-inducible factor-1α (HIF-1α), glucose transporter-1 (GLUT-1), hexokinase-2 (HK-2) and PDK-1. In an in vitro analysis, the lactate production and glucose uptake levels, cellular viability and 5-fluorouracil (5-FU) responses were evaluated before and after treatment with dichloroacetate (DCA), a PDK-1 inhibitor, in the MKN45 and AGS gastric cancer cell lines and in the non-cancerous HEK293 cell line. GLUT-1 and PDK-1 expression was significantly associated with tumor progression, although only PDK-1 expression was an independent prognostic factor for patients who received 5-FU adjuvant treatment. There was no significant difference in cell viability between the HEK293 and gastric cancer cell lines following DCA treatment. However, DCA treatment reduced lactate production and increased responsiveness to 5-FU in MKN45 cells, which expressed high levels of PDK-1 in comparison to the other cell lines. Thus, PDK-1 may serve as a biomarker of poor prognosis in patients with gastric cancer. In addition, PDK-1 inhibitors such as DCA may be considered an additional treatment option for patients with PDK-1-expressing gastric cancers.
PMCID: PMC3583751  PMID: 23135628
gastric neoplasm; chemotherapy; pyruvate dehydrogenase; prognosis
18.  The Effects of Helicobacter pylori on the prognosis of patients with curatively resected gastric cancers in a population with high infection rate 
The goal of this study was to assess the correlation between the Helicobacter pylori status of patients who underwent curative resection for gastric adenocarcinoma and their prognosis in Eastern societies where H. pylori infection is prevalent.
Between 2006 and 2007, 192 patients who had a curative resection for the treatment of gastric adenocarcinoma were enrolled in the study. Of these patients, 18 were excluded due to an inexact evaluation of the H. pylori status, thereby leaving 174 patients in the final analysis. Serologic testing for H. pylori was assessed using an enzyme-linked immunosorbent assay kit for immunoglobulin G, and the histological presence of H. pylori was identified using the Giemsa stain.
Of the 174 patients, 111 patients (63.8%) were confirmed for H. pylori infection. H. pylori status did not correlate with the overall or disease-free survival. For patients with stage III or IV gastric cancer, a positive H. pylori status was a significant predictive factor for recurrence over that of a negative H. pylori status (P = 0.019). Negative H. pylori status was a predictive factor for recurrence in multivariable analysis (relative risk, 2.724; 95 confidence interval, 1.192 to 6.228).
Helicobacter pylori status did not correlate with the clinicopathologic factors of gastric adenocarcinoma. However, a negative Helicobacter pylori status may be a predictive factor for recurrence in patients diagnosed with advanced gastric adenocarcinoma.
PMCID: PMC3467386  PMID: 23091792
Helicobacter pylori; Stomach neoplasm; Prognosis; Survival
19.  Photodynamic Inactivation of Bacteria Using Polyethylenimine–Chlorin(e6) Conjugates: Effect of Polymer Molecular Weight, Substitution Ratio of Chlorin(e6) and pH 
Lasers in surgery and medicine  2011;43(4):313-323.
Background and Objectives
Antimicrobial photodynamic therapy (APDT) is a novel technique to treat local infections. Previously we reported that the attachment of chlorin(e6) to polyethylenimine (PEI) polymers to form PEI-ce6 conjugates is an effective way to improve ce6 PDT activity against bacteria. The aim of this work was to explore how the polymer molecular weight, substitution ratio (SR) of ce6 and pH value affect the PDT efficacy.
Study Design/Materials and Methods
We have synthesized PEI-ce6(10) (MW = 60,000, SR = 1) and PEI-ce6(11) (MW = 60,000, SR = 5) and compared these with the previous PEI-ce6(9) (MW = 10,000, SR = 1). We tested the PDT efficacy of these three conjugates against Gram-negative E. coli and Gram-positive bacteria (S. aureus and E. fecalis) at three different pH values (5.0, 7.4, 10.0) that may affect the charge on both the bacterial cells and on the conjugate (that has both basic and acidic groups).
PEI-ce6(9) and PEI-ce6(10) were the most effective against these tested bacteria. The PDT effect of all three conjugates depended on pH values. The effective order was pH = 10.0 > pH = 7.4 > pH = 5.0 on E. coli. For S. aureus and E. fecalis the order was pH = 5.0 > pH = 10.0 > pH = 7.4. PEI-ce6(11) PDT activity was worse than PEI-ce6(10) activity which is probably connected to the fact that ce6 molecules are self-quenched within the PEI-ce6(11) molecule. Ce6 quenching within the PEI-ce6 molecules was proved by analyzing fluorescence spectra of PEI-ce6 conjugates at different pH values. There were no differences in bacterial uptake between different pH values in three PEI-ce6 conjugates.
We assume high pH (rather than low pH as was hypothesized) disaggregates the conjugates, so the higher pH was more effective than the lower pH against E. coli. But for Gram-positive bacteria, low pH was more effective possibly due to more overall positive charge on the conjugate. Lasers Surg. Med. 43:313–323, 2011.
PMCID: PMC3449165  PMID: 21500226
antimicrobial photodynamic therapy; polyethylenimine–chlorine(e6) conjugate; pH value; polymer molecular weight; substitution ratio; static and dynamic quenching
20.  Comparison of Surgical Outcomes between Robotic and Laparoscopic Gastrectomy for Gastric Cancer: The Learning Curve of Robotic Surgery 
Journal of Gastric Cancer  2012;12(3):156-163.
Laparoscopic gastrectomy is a widely accepted surgical technique. Recently, robotic gastrectomy has been developed, as an alternative minimally invasive surgical technique. This study aimed to evaluate the question of whether robotic gastrectomy is feasible and safe for the treatment of gastric cancer, due to its learning curve.
Materials and Methods
We retrospectively reviewed the prospectively collected data of 100 consecutive robotic gastrectomy patients, from November 2008 to March 2011, and compared them to 282 conventional laparoscopy patients during the same period. The robotic gastrectomy patients were divided into 20 initial cases; and all subsequent cases; and we compared the clinicopathological features, operating times, and surgical outcomes between the three groups.
The initial 20 robotic gastrectomy cases were defined as the initial group, due to the learning curve. The initial group had a longer average operating time (242.25±74.54 minutes vs. 192.56±39.56 minutes, P>0.001), and hospital stay (14.40±24.93 days vs. 8.66±5.39 days, P=0.001) than the experienced group. The length of hospital stay was no different between the experienced group, and the laproscopic gastrectomy group (8.66±5.39 days vs. 8.11±4.10 days, P=0.001). The average blood loss was significantly less for the robotic gastrectomy groups, than for the laparoscopic gastrectomy group (93.25±84.59 ml vs. 173.45±145.19 ml, P<0.001), but the complication rates were no different.
Our study shows that robotic gastrectomy is a safe and feasible procedure, especially after the 20 initial cases, and provides a satisfactory postoperative outcome.
PMCID: PMC3473222  PMID: 23094227
Robotic; Laparoscopy; Compared; Gastrectomy; Learning curve
21.  Synergistic Combination of Chitosan Acetate with Nanoparticle Silver as a Topical Antimicrobial: Efficacy against Bacterial Burn Infections ▿ 
Chitosan and nanoparticle silver are both materials with demonstrated antimicrobial properties and have been proposed singly or in combination as constituents of antimicrobial burn dressings. Here, we show that they combine synergistically to inhibit the in vitro growth of Gram-positive methicillin-resistant Staphylococcus aureus (MRSA) and Gram-negative bacteria (Pseudomonas aeruginosa, Proteus mirabilis, and Acinetobacter baumannii), as judged by bioluminescence monitoring and isobolographic analysis, and also produce synergistic killing after 30 min of incubation, as measured by a CFU assay. The hypothesized explanation involves chitosan-mediated permeabilization of bacterial cells, allowing better penetration of silver ions into the cell. A dressing composed of freeze-dried chitosan acetate incorporating nanoparticle silver was compared with a dressing of chitosan acetate alone in an in vivo burn model infected with bioluminescent P. aeruginosa. The survival rates of mice treated with silver-chitosan or regular chitosan or left untreated were 64.3% (P = 0.0082 versus regular chitosan and P = 0.0003 versus the control), 21.4%, and 0%, respectively. Most of the fatalities occurred between 2 and 5 days postinfection. Silver-chitosan dressings effectively controlled the development of systemic sepsis, as shown by blood culture. These data suggest that a dressing combining chitosan acetate with silver leads to improved antimicrobial efficacy against fatal burn infections.
PMCID: PMC3122390  PMID: 21502618
22.  Efficacy of Roux-en-Y Reconstruction Using Two Circular Staplers after Subtotal Gastrectomy: Results from a Pilot Study Comparing with Billroth-I Reconstruction 
Journal of Gastric Cancer  2011;11(4):219-224.
The Roux en Y method has rarely been performed due to longer operation time and high risk of complication, despite several merits including prevention of bile reflux. We conducted a retrospective review of the result of Roux en Y reconstruction using two circular staplers after subtotal gastrectomy.
Materials and Methods
From December 2008 to May 2009, a total of 26 patients underwent Roux en Y reconstruction using two circular staplers after subtotal gastrectomy, and seventy-two patients underwent Billroth-I reconstruction. Roux en Y anastomosis was performed using two circular staplers without hand sewing anastomosis. We compared clinicopathologic features and surgical outcomes between the two groups. All patients underwent gastrofiberscopy between six and twelve months after surgery to compare the bile reflux.
No significant differences in clinicopathologic findings were observed between the two groups, except for the rate of minimal invasive surgery (P=0.004) and cancer stage (P=0.002). No differences in the rate of morbidity (P=0.353) and admission duration (P=0.391) were observed between the two groups. Gastrofiberscopic findings showed a significant reduction of bile reflux in the remnant stomach in the Roux en Y group (P=0.019).
When compared with Billroth-I reconstruction, Roux en Y reconstruction using the double stapler technique was found to reduce bile reflux in the remnant stomach without increasing postoperative morbidity. Based on these results, we planned to begin a randomized controlled clinical trial for comparison of Roux en Y reconstruction using this method with Billroth-I anastomosis.
PMCID: PMC3273692  PMID: 22324013
Stomach neoplasms; Gastrectomy; Reconstructive surgical procedure
23.  Burden of Pneumonia and Meningitis Caused by Streptococcus pneumoniae in China among Children under 5 Years of Age: A Systematic Literature Review 
PLoS ONE  2011;6(11):e27333.
Background and Methods
To understand the burden and epidemiology of Streptococcus pneumoniae disease among children between 1 and 59 months of age in China, we conducted a review of literature published between 1980 and 2008 applying standardized algorithms. Because of the absence of population-based surveillance for pneumococcal disease (PD), we identified all-cause pneumonia, bacteremia and meningitis burden, syndromes most commonly associated with S. pneumoniae, and applied the proportion of disease attributable to S. pneumoniae from studies that determined the etiology of these three syndromes to calculate PD burden. Because of the microbiologic difficulties in identifying S. pneumoniae–attributable pneumonia which likely underestimates the pneumonia burden, we also used the proportion obtained from vaccine efficacy trials.
Between 1980 and 2008, there were 12,815 cases/100,000/year of all-cause pneumonia among children between 1 month and 59 months, with 526 deaths/100,000 annually. There were 14 meningitis cases/100,000/year. We estimate that as of 2000, there were 260,768 (113,000 to 582,382) and 902 (114–4,463) cases of pneumococcal pneumonia and meningitis, respectively with 10,703 (4,638–23,904) and 75 (9–370) pneumococcal pneumonia and meningitis deaths, respectively. Pneumococcal pneumonia cases and deaths were more than two-fold higher, 695,382 (173,845–1,216,918) and 28,542 (7,136–49,949), respectively, when parameters from efficacy trials were used. Serotypes 19F, 19A and 14 were the most common serotypes obtained from pneumonia/meningitis patients. Currently available vaccines are expected to cover 79.5% to 88.4% of the prevalent serotypes. With high antibiotic resistance, introducing pneumococcal vaccines to the routine immunization program should be considered in China. Population-based studies are warranted.
PMCID: PMC3217934  PMID: 22110628
24.  Robotic redo fundoplication for incompetent wrapping after antireflux surgery: A case report 
Incidence of gastroesophageal reflux disease (GERD) is high. antireflux surgery with specific indications could be an option. Nissen fundoplication is the most popular surgical procedure for GERD, and recent results using laparoscopy have reported excellent short- and mid-term results. Regarding surgical outcome of antireflux surgery, the rate of complications has been reported as below 2.4%, but rare cases still require reoperation.
A 53-year old male patient underwent laparoscopic Nissen fundoplication three years ago owing to gastroesophageal reflux disease (GERD) troubled by dysphagia and heartburn However, despite undergoing surgery, his symptoms did not show improvement .A robotic redo fundoplication was planned. The patient recovered uneventfully, and the esophagography on postoperative day four revealed improvement of previous upward contrast reflux and distension of the distal esophagus during swallowing had disappeared. Dysphagia and heartburn had still not occurred at one year follow-up.
Redo antireflux surgery for postoperative stricture is not an easy procedure due to postoperative adhesion and anatomical change. Robotic surgery may be more helpful for precise dissection of the adhesion site by a previous operation and robotic suturing for re-fundoplication was more effective.
Re-do fundoplication using a robot, which is a complicated procedure compared with primary anti-reflux surgery would be a general procedure in the near future.
PMCID: PMC3215201  PMID: 22096753
Gastroesophageal reflux disease; Redo fundoplication; Robotic surgery
25.  Isoflurane pre-treatment before cardiopulmonary bypass alleviates neutrophil accumulation in dog lungs 
Cardiovascular Journal of Africa  2011;22(3):128-133.
This study investigated the effect of isoflurane pre-treatment on cardiopulmonary bypass (CPB)-related lung injury.
Twelve dogs were randomly divided into two groups of six each. In one group, 1.0 minimum alveolar concentration (MAC) of isoflurane was administered for 30 min before CPB, while the control group received no anaesthetic. Both groups then underwent 100 min of mild hypothermic CPB with 60-min aortic cross clamping. Haemodynamic parameters, respiratory mechanics and alveolar arterial oxygen difference (AaDO2) were measured during the experiment. One hundred and fifty minutes after CPB, lung tissue samples from the non-dependent and dependent portions of the left and right lungs were harvested for polymorphonulear leukocyte (PMNs) counts.
Following CPB, within the control group, pulmonary vascular resistance (PVR) was significantly increased at 60, 120 and 180 min after declamping, AaDO2 deteriorated at 180 min post-declamping, and dynamic lung compliance (DLC) was reduced dramatically after declamping. Isoflurane pre-treatment before CPB significantly reduced PVR compared to the controls. AaDO2 was impaired at 180 min after declamping and DLC was decreased after declamping within the isoflurane group. No differences in AaDO2 and DLC were found between the isoflurane and control groups. At 180 min after declamping, the PMN count in both the non-dependent and dependent regions of the isoflurane pre-treated lungs was significantly lower than that of the controls.
Our results suggest that 30-min pre-treatment with 1.0 MAC isoflurane before CPB caused a reduction in PMN accumulation in the dog lungs, inhibition of increases in PVR, and it did not affect AaDO2 in the early post-CPB stage.
PMCID: PMC3721866  PMID: 21107494
cardiopulmonary bypass; lung injury; isoflurane; dog

Results 1-25 (34)