Altered mechanosensitive properties of vagal afferent fibers innervating the stomach following gastric surgery in rats

BACKGROUND AND AIMS

Several types of gastric surgeries have been associated with early satiety, dyspepsia and food intolerances. We aimed to examine alterations in gastric vagal afferents following gastric surgery-fundus ligation.

METHODS

Six week old, male Sprague-Dawley rats underwent chronic ligation (CL) of the fundus. Sham rats underwent abdominal surgery, but without ligation. Another group of rats underwent acute ligation (AL) of the fundus immediately prior to experiments. CL and sham rats were allowed to grow to age 3-4 months. Food intake and weights were recorded post-operatively. Gastric compliance and gastric wall thickness was measured at baseline and during gastric distension (GD). Extracellular recordings were made to examine response characteristics of vagal afferent fibers to GD and to map the stomach receptive field (RF). The morphological structures of afferent terminals in the stomach were examined with retrograde tracings from the nodose ganglion.

RESULTS

The CL group consumed significantly less food and weighed less than sham control. The mean compliance of the CL group was significantly less than control, but higher than the AL group. The spontaneous firing and responses to GD of afferent fibers from the CL rats were significantly higher than AL rats. There was a marked expansion of the gastric RF in the CL rats with significant reorganization and regeneration of intramuscular array (IMA) terminals. There was no difference in total wall or muscle thickness among the groups.

CONCLUSION

CL results in aberrant remodeling of IMAs with expansion of the gastric RF and alters the mechanotransduction properties of vagal afferent fibers. These changes could contribute to altered sensitivity following gastric surgery.

A phase I study assessing the feasibility and safety of intraductal pegylated liposomal doxorubicin (PLD) in women with breast cancer

e11506

Background: Most breast cancers originate in epithelial cells lining the breast ducts. Preclinical data suggest that intraductal administration of chemotherapy including PLD decrease tumor volume, prevent the development of new lesions, and eradicate pre-malignant disease. We initiated a clinical trial to determine the feasibility, safety, and maximum tolerated dose of PLD administered into one duct of women awaiting mastectomy. Methods: Women 18 or older awaiting mastectomy for breast cancer were eligible. Preoperative chemotherapy was allowed. T4 tumors, prior breast irradiation, or surgeries that may have altered the ductal system were excluded. Nipple aspiration and ductal cannulation were completed and the first 3 women received 5 mL of intraductal dextrose. PLD was administered to subsequent participants on a dose escalation schema based on preclinical pharmacokinetic and safety data. Serial doxorubicin (Dox) and doxorubicinol (Doxol) concentrations were determined in plasma by LC/MS/MS. At mastectomy (completed at least 2 weeks after intraductal administration of PLD), blue dye was injected into the treated duct and tissue was obtained for pharmacokinetic and biomarker analysis. Results: From 2/06 to 6/08, 14 women enrolled, and 12 underwent all study procedures. All dose levels up to 10 mg PLD per one duct were completed without serious adverse events. Median pain score was 0.9 (0–2.3). Intraductal PLD resulted in a dose-dependent increase in both systemic and local exposure to dox and doxol. Neither dox nor the metabolite was detected in the contralateral breast. Systemic exposure was lower than with conventionally administered PLD. Inflammatory changes were not observed on histopathological review of mastectomy specimens. Conclusions: We have established the logistics of intraductal administration of agents in an outpatient setting and it is feasible in women with and without prior chemotherapy. Biomarker data will be completed prior to the meeting. Future studies will evaluate other agents administered to one or more ducts.

[Table: see text]

Phase I study of enzastaurin (ENZ) and bevacizumab (BV) in patients with advanced cancer: Safety, pharmacokinetics (PK), and response assessment

3517

Background: ENZ, an oral kinase inhibitor, suppresses tumor growth through PKC and PI-3 kinase/AKT. BV binds VEGF and inhibits angiogenesis. Since ENZ and BV are complementary in inhibiting angiogenesis, we conducted a Phase I study of ENZ / BV. Methods: Eligible patients (pts) had advanced cancer, adequate organ function and no co-morbidities for increased risk of drug-related toxicities. Six pts were enrolled per cohort; if ≤1 DLT the next cohort opened. A loading dose of ENZ 1125 mg was given on Day 1, C1. After 1 cohort combining ENZ 500 mg/QD and BV at 5mg/kg IV q 2 wks, subsequent cohorts alternated pts between BV 10 mg/kg IV q 2 wks and BV 15 mg/kg IV q 3wks with escalating doses of ENZ (500 mg/QD, 250 mg/BID, and 375 mg/BID) for a total of 7 cohorts. DLT was defined as C1: Grade (G)4 neutropenia ≥7 days, febrile neutropenia, G3 thrombocytopenia with bleeding or G4 thrombocytopenia; G3/G4 non-hematological toxicities, and toxicities associated with BV. ENZ PK was performed at steady-state on Day 1, C2. Results: 43 pts (21 with ovarian cancer) are evaluable for toxicity. Two DLTs (G3 elevated aminotransferase and intraparenchymal hemorrhage) occurred at different dose levels. No apparent increase in ENZ or BV toxicity was seen. Two SAEs (DVT and myocardial ischemia) in two pts occurred at DL 3 after 3 cycles and 13 cycles, respectively. Common toxicities included fatigue, chromaturia, dry/sore mouth, nausea and diarrhea. Nine of 43 pts (21%) had a response (CR, PR), 6 responses were in the ovarian subset (29%). Median time to progression was 3.9 mos (range 0–19.2 mos) and 7.7 mos for ovarian pts (range 0.3–19.2 mos). Overall, 43% remained on study without disease progression for >6 mos (51% of ovarian pts remained on study for >6 mos). Mean steady-state ENZ concentrations (%CV) at 500 mg/QD, 250mg/BID and 375mg/BID were 1080 nmol/L (82.8 %), 516 nmol/L (102%) and 1120 nmol/L (93.3%), respectively. Conclusions: The addition of ENZ to BV in any of the currently approved BV dosing schedules is well tolerated and clinically active in advanced cancer pts. ENZ exposures are highly variable and comparable across the three dose groups. The combination of ENZ / BV demonstrates encouraging activity, specifically in our population of ovarian cancer pts.

[Table: see text]

A pilot study of biological markers (BM) as predictors for response and prognosis in patients (pts) with R0 resected gastric cancer (GC)

e22076

Background: To evaluate clinical value of biological markers and their prognostic significance in gastric cancer as well as prediction to clinic outcome; To select preference marker for targeted therapy in high risk patients hence to guide personalized treatment. Methods: Retrieved from total 394 patients treated during the period of Jan 2004 to June 2006 of Cancer Hospital, Fudan University with complete medical records and follow up data, 84 patients with pre- and post- operative biological markers examined were selected. All of these patients underwent R0 gastrectomy, 61 (72.6%) patients underwent D2 resection. Forty- one (48.8%) patients received ≥ 4 cycles adjuvant chemotherapy. Preoperative tumor markers include: CEA, AFP, CA199, CA50, CA72–4, CA24–2 and postoperative immunohistochemical examination include: Bax, Bcl-2, P27, CyclinD1, TOPO2, MDR, GST-π, Ki67, AgNOR, EGFR, P21, P53, PCNA, C-myc and Neu were analyzed. Univariate, multivariate and Logistic regression analysis were performed and Kapan-Meier estimates were calculated. Results: For the whole group, 2-year OS and PFS were 76% and 66% respectively. Logistic regression analysis showed bcl-2, ki67, c-myc2 and Neu were relative with more nodal involvement. Patients with lower level of CEA, CA72–4 and higher level of cyclin D1 suivived longer than the other patients. There were different clinical significance with those biomarkers. Patients with lower level of cyclinD1, CEA had more local regional recurrence (p=0.026) while patients with higher PCNA experienced more distant metastasis (p=0.005). Univariate analysis showed that clinical staging, level of cyclinD1 and CEA were correlated with OS (p<0.05). Conclusions: Biological markers may be helpful in predicting the clinical outcome and prognosis for R0 resected gastric cancer patients. Further study are needed to confirm their clinical significance.

No significant financial relationships to disclose.

Comparison of cisplatin (CDDP) and radiation (RT) to cetuximab (C) and RT for locally advanced head and neck cancer (LAHNC): A preliminary analysis

6042

Background: Both concurrent CDDP/RT and C/RT have been shown in randomized trials to yield superior disease control compared to RT alone in LAHNC, but no randomized trial has compared them. We evaluated our center's experience with these regimens. Methods: From 3/1/06 - 4/1/08, 175 patients were retrospectively identified who received definitive treatment for LAHNC with CDDP (planned total dose 100 mg/m2 Q3 weeks X 3) and RT (n = 125) or C (400 mg/m2 load; 250 mg/m2 weekly) and RT (n = 50). Patients who received prior RT, additional systemic therapy, and/or surgery to the primary site were excluded. C was given for the following reasons: auditory 30%, renal 4%, cardiac 2%, performance status 18%, patient choice 16%, neuropathy 4%, unknown 2%, and a combination of factors 24%. The median age: CDDP group 56, 6% >71; C group 66.5, 40% >71. Additional CDDP and C features: male sex, 86 v 78%; stage IV, 70 v 68%; and oropharynx, 78 v 70%. Median RT dose (70 Gy), RT length (46 days), and Karnofsky performance status (KPS) (90%) were the same; alcohol/tobacco use was similar. Results: At a median follow up of 18.7 months, with death without local failure (LF) as a competing risk, the 18 month LF incidence rate was 2.5% in the CDDP group and 43.3% in the C group (p < 0.0001), with the latest event occurring at 16.5 months. The 18 month disease-free survival (DFS) and overall survival (OS) rates were 85.7 v 40.9%, and 96.8 v 73.1%, in favor of CDDP (p < 0.0001 for both). Initially, 21 variables were assessed for significance, and when Cox proportional hazards model was used for multivariate analysis to address prognostic imbalances, treatment with CDDP still predicted for improved LF, DFS, and OS (p < 0.0001 for LF and DFS; p = 0.0017 for OS). For OS analysis, the concordance probability estimates were .67 for using drug choice alone and .80 for using drug choice, T stage, RT dose, and KPS. Conclusions: CDDP/RT and C/RT were used to treat somewhat different populations with LAHNC. The observed superiority of CDDP/RT compared to C/RT in LF, DFS, and OS may reflect patient selection issues. However, preliminary multivariate modeling suggests that CDDP/RT remains the preferred option for fit patients pending further analyses and prospective studies comparing these regimens.

[Table: see text]

Cellular magnetic resonance imaging: potential for use in assessing aspects of cardiovascular disease

There is rapidly increasing interest in the use of magnetic resonance imaging (MRI) to track cell migration in vivo. Iron oxide MR contrast agents can be detected at micromolar concentrations of iron, and offer sufficient sensitivity for T2*-weighted imaging. Cellular MRI shows potential for assessing aspects of cardiovascular disease. Labeling in vivo and tracking macrophages using iron oxide nanoparticles has been a goal for cellular MRI because macrophages play a pivotal role in the pathophysiology of many human diseases, including atherosclerosis. Cellular MRI has also been using to track transplanted therapeutic cells in myocardial regeneration. This review looked at iron oxide nanoparticles, methods of cell labeling, image acquisition techniques and limitations encountered for visualization. Particular attention was paid to stem cells and macrophages for the cardiovascular system.

Superparamagnetic iron oxide nanoparticle-labeled cells as an effective vehicle for tracking the GFP gene marker using magnetic resonance imaging

BACKGROUND

Detection of a gene using magnetic resonance imaging (MRI) is hindered by the magnetic resonance (MR) targeting gene technique. Therefore it may be advantageous to image gene-expressing cells labeled with superparamagnetic iron oxide (SPIO) nanoparticles by MRI.

METHODS

The GFP-R3230Ac (GFP) cell line was incubated for 24 h using SPIO nanoparticles at a concentration of 20 microg Fe/mL. Cell samples were prepared for iron content analysis and cell function evaluation. The labeled cells were imaged using fluorescent microscopy and MRI.

RESULTS

SPIO was used to label GFP cells effectively, with no effects on cell function and GFP expression. Iron-loaded GFP cells were successfully imaged with both fluorescent microscopy and T2*-weighted MRI. Prussian blue staining showed intracellular iron accumulation in the cells. All cells were labeled (100% labeling efficiency). The average iron content per cell was 4.75+/-0.11 pg Fe/cell (P<0.05 versus control).

DISCUSSION

This study demonstrates that the GFP expression of cells is not altered by the SPIO labeling process. SPIO-labeled GFP cells can be visualized by MRI; therefore, GFP, a gene marker, was tracked indirectly with the SPIO-loaded cells using MRI. The technique holds promise for monitoring the temporal and spatial migration of cells with a gene marker and enhancing the understanding of cell- and gene-based therapeutic strategies.

[Studies on immunoprotection in mice after immunization with Schistosoma japonicum 22.6 kDa recombinant protein]

AIM

To evaluate the immunoprotective effect of Schistosoma japonicum recombinant 22.6 kDa (rSj22.6) and Sj22.6/Sj26 GST fusion protein.

METHODS

The Sj22.6/Sj26 GST fusion protein was prepared by affinity chromatography using glutathione Sepharose 4B. The purified rSj22.6 could be cleaved easily from the fusion protein with Thrombin. 17 and 12 mice immunized with rSj22.6 and Sj22.6/Sj26 GST separately were each challenged with 40 +/- 1 S. japonicum cercariae.

RESULTS

In BALB/c mice, the rSj22.6 and Sj22.6/Sj26 GST could induce 32.1 (P < 0.005) and 34.9% (P < 0.02) worm reduction, respectively, as well as 28.4% (P < 0.02) and 45.1% (P < 0.005) total egg reduction, respectively.

CONCLUSION

Bpth rSj22.6 and Sj22.6/Sj26 GST fusion protein are partially effective against S. japonicum.

Morphology-controlled synthesis and a comparative study of the physical properties of SnO2 nanostructures: from ultrathin nanowires to ultrawide nanobelts

Controlled synthesis of one-dimensional materials, such as nanowires and nanobelts, is of vital importance for achieving the desired properties and fabricating functional devices. We report a systematic investigation of the vapor transport growth of one-dimensional SnO(2) nanostructures, aiming to achieve precise morphology control. SnO(2) nanowires are obtained when SnO(2) mixed with graphite is used as the source material; adding TiO(2) into the source reliably leads to the formation of nanobelts. Ti-induced modification of crystal surface energy is proposed to be the origin of the morphology change. In addition, control of the lateral dimensions of both SnO(2) nanowires (from approximately 15 to approximately 115 nm in diameter) and nanobelts (from approximately 30 nm to approximately 2 microm in width) is achieved by adjusting the growth conditions. The physical properties of SnO(2) nanowires and nanobelts are further characterized and compared using room temperature photoluminescence, resonant Raman scattering, and field emission measurements.

QTL analyses of seed weight during the development of soybean (Glycine max L. Merr.)

At harvest traits such as seed weight are the sum of development and responses to stresses over the growing season and particularly during the reproductive phase of growth. The aim here was to measure quantitative trait loci (QTL) underlying the seed weight from early development to drying post harvest. One hundred forty-three F(5) derived recombinant inbred lines (RILs) developed from the cross of soybean cultivars 'Charleston' and 'Dongnong 594' were used for the analysis of QTL underlying mean 100-seed weight at six different developmental stages. QTL x Environment interactions (QE) were analyzed by a mixed genetic mode based on 3 years' data. At an experiment-wise threshold of a=0.05 and by single-point analysis 94 QTL unaffected by QE underlay the mean seed weight at different developmental stages. Sixty-eight QTL affected by QE that also underlay mean seed weight were identified. From the 162 QTL 42 could be located on 12 linkage groups by composite interval mapping (LOD>2.0). The numbers, locations and types of the QTL and the genetic effects were different at each developmental stage. On linkage group C2 the distantly linked QTL swC2-1, swC2-2 and swC2-3 each affected mean seed weight throughout the different developmental stages. The DNA markers linked to the QTL possessed potential for use in marker-assisted selection for soybean seed size. The identification of QTL with genetic main effects and QE interaction effects suggested that such interactions might significantly alter seed weight during seed development.

Ferroelectric transistors with nanowire channel: toward nonvolatile memory applications

We report the fabrication and characterization of ZnO nanowire memory devices using a ferroelectric Pb(Zr(0.3)Ti(0.7))O(3) (PZT) film as the gate dielectric and the charge storage medium. With a comparison to nanowire transistors based on SiO(2) gate oxide, the devices were evaluated in terms of their electric transport, retention, and endurance performance. Memory effects are observed as characterized by an eminent counterclockwise loop in I-V(g) curves, which is attributed to the switchable remnant polarization of PZT. The single-nanowire device exhibits a high (up to 10(3)) on/off ratio at zero gate voltage. Our results give a proof-of-principle demonstration of the memory application based on a combination of nanowires (as channels) and ferroelectric films (as gate oxide).

Atomic structure of the epitaxial BaO/Si(001) interface

We present the structure of the interface responsible for epitaxy of crystalline oxides on silicon. Using synchrotron x-ray diffraction, we observe a 2 x 1 unit cell reconstruction at the interface of BaO grown on Si(001) terminated with 1/2 ML of Sr. Since this symmetry is not present in bulk BaO or Si, only the interface contributes to diffracted intensity. First principles calculations accurately predict the observed diffraction and identify the structure of the BaO/Si interface, including the elemental composition and a sub-A rumpling due to epitaxial strain of the 7 adjacent BaO and Si layers.

Two pathways for water interaction with oxygen adatoms on TiO2(110)

Scanning tunneling microscopy and density functional theory studies show that oxygen adatoms (Oa), produced during O2 exposure of reduced TiO2(110) surfaces, alter the water dissociation and recombination chemistry through two distinctive pathways. Depending on whether H2O and Oa are on the same or adjacent Ti4+ rows, Oa facilitates H2O dissociation and proton transfer to form a terminal hydroxyl pair, positioned along or across the Ti4+ row, respectively. The latter process has not been reported previously, and it starts from a "pseudodissociated" state of water. In both pathways, the reverse H transfer results in H2O reformation and O scrambling, as manifested by an apparent along- or across-row motion of Oa's.

Multifunctional CuO nanowire devices: p-type field effect transistors and CO gas sensors

We report the properties of a field effect transistor (FET) and a gas sensor based on CuO nanowires. CuO nanowire FETs exhibit p-type behavior. Large-scale p-type CuO nanowire thin-film transistors (10(4) devices in a 25 mm(2) area) are fabricated and we effectively demonstrate their enhanced performance. Furthermore, CuO nanowire exhibits high and fast response to CO gas at 200 degrees C, which makes it a promising candidate for a poisonous gas sensing nanodevice.

Screening and characterization of monoclonal antibodies to the surface antigens of Listeria monocytogenes serotype 4b

AIMS

This study aims to develop and characterize monoclonal antibodies (Mabs) with high specificity and affinity for surface antigens of an epidemiologically important serotype 4b of Listeria monocytogenes.

METHODS AND RESULTS

Hybridoma clones were derived from B lymphocytes of mice immunized with L. monocytogenes serotype 4b and screened against this strain by an enzyme-linked immunosorbent assay. Twenty-nine clones secreting Mabs reactive with formalin-killed bacteria were obtained; 15, 8, 5 and 1 Mabs were immunoglobulin subclasses IgG2a, IgG2b, IgM and IgG1, respectively. Immunofluorescence or immunogold labelling demonstrated all except five IgM and one IgG2a Mabs bound to the surface of a live L. monocytogenes serotype 4b. The majority of the 23 surface-binding Mabs recognized linear epitopes on a 77-kDa protein. These surface-binding Mabs exhibited little or no cross-reactivity with non-4b serotypes (1/2a, 1/2b, 3a, etc.) of L. monocytogenes, five other Listeria species, Escherichia coli O157:H7 and Salmonella enterica serovar Typhimurium.

CONCLUSIONS

The Mabs recognizing a 77-kDa surface protein are novel antibodies with specificity and affinity for L. monocytogenes serotype 4b.

SIGNIFICANCE AND IMPACT OF THE STUDY

These anti-77 kDa surface protein Mabs may be explored as reagents for the development of Mabs-based diagnostic immunoassays for L. monocytogenes serotype 4b strains.

Influence of exposure intensity on the efficiency and speed of transmission of Foot-and-mouth disease

Foot-and-mouth disease virus (FMDV) can be spread by direct animal-to-animal contact, indirect contact facilitated by contaminated materials or by airborne spread. The rate of spread and the incubation period, as well as the severity of disease, depends on many variables including the dose received, the route of introduction, the virus strain, the animal species and the conditions under which the animals are kept. Quantitative data related to these variables are needed if model predictions are to be used in practical disease control. This experimental study quantifies the risk of transmission of FMDV in pigs exposed by contact, sheep exposed by indirect contact with pigs and sheep exposed to airborne FMDV. Groups of pigs were inoculated with the FMDV O UKG 34/2001 strain and susceptible pigs were then exposed to the inoculated animals at different stages of the infection cycle. The mean incubation period in the susceptible pigs ranged from 1 to 10 days. The length of the incubation period, severity of clinical disease and efficiency of spread were related to dose (i.e. infectiousness of source and intensity of contact). Low intensity transmission increased the proportion of subclinical or abortive infections. Local conditions are important in the efficiency and speed of transmission of FMDV. The results of the experiments described above suggest that transmission is frequency dependent rather than density dependent. The sheep experiments provided further evidence that development of infection and clinical disease is dependent upon local conditions. Dose, infectiousness, intensity of contact and local factors are thus important determinants for the outcome of an initial outbreak and must be truthfully accounted for in mathematical models of epidemiological spread.

Quantitative trait loci for porcine white blood cells and platelet-related traits in a White Duroc x Erhualian F resource population

White blood cell count and platelets are implicated as risk factors for common complex diseases. Genetic factors substantially affect these traits in humans and mice. However, little is known about the genetic architecture of these traits in pigs. To identify quantitative trait loci (QTL) for leucocyte- and platelet-related traits in pigs, the total leucocyte number and differential leucocyte counts including the fraction of basophils, eosinophils, lymphocytes, monocytes, neutrophils, and a series of platelet parameters including platelet count, mean platelet volume, platelet distribution width and plateletcrit were measured in 1033 F(2) animals on 240 days from a White Duroc x Erhualian intercross resource population. A total of 183 informative microsatellites distributed across 19 pig chromosomes (SSC) were genotyped across the entire resource population. Thirty-three QTL were identified for the examined traits, including eight genome-wide significant QTL for white blood cells and differential leucocyte counts on SSC2, 7, 8, 12 and 15 and six significant QTL for platelet-related traits on SSC2, 8, 13 and X. Erhualian or White Duroc alleles were not systematically associated with increased phenotypic values. These results not only confirmed many QTL identified previously in the mouse and swine, but also revealed a number of novel QTL for the traits recorded. Moreover, it is the first time that QTL for platelet-related traits in pigs have been reported.