Coculturing embryonic stem cells with damaged hepatocytes leads to restoration of damage and high frequency of fusion

Controversy surrounds issue of cell fusion as a repair mechanism whereby stem cells regenerate. To identify the ratio of fusion happens between stem cells and damaged cells, hepatic cells were damaged with 200microM H2O2 for 2 hr. Then, mouse ESCs were cocultured with damaged human hepatocytes. Fusion was detected directly by karyotyping after 48hr coculture as well as by Oct4 promoter drove GFP signal. Results showed that average ratio of fusion in undamaged control group was 0.031 per thousand while ratio of fusion in damaged group was 0.357 per thousand, which was 10 times higher than fusion happened in the control group. Meanwhile, GFP signal indicated that fusion induced hepatic cells' Oct-4 reactivation. Fusion derived hybrid cells contained chromosomes from both parental cells. Most of the chromosomes were from damaged human hepatic cells. Activity of damage-related enzymes LDH, SGOT and SGPT were significantly lower at 48hr coculture than at 12hr coculture. Expression of albumin in co-culture system was up-regulated after coculture, which indicated the reparation of damage after coculturing. Also, by applying RT-PCR and immunocytochemistry differentiation status of ES cells were evaluated. It was shown that ES cells differentiated to hepatic lineage cells and expressed hepatic genes and proteins.

Temporal trends in cause-specific late mortality among five-year survivors of childhood cancer

10004

Background: Five-year survival rates for childhood cancer have increased over the past 4 decades, increasing the number of long-term survivors. Among 5-yr survivors, the impact of changes in therapy on cause-specific late mortality has not been thoroughly assessed. Methods: Late mortality was evaluated over 3 eras (1974–81, 1982–90, 1991–2000) in 26,643 5-year survivors diagnosed <21 years of age from the SEER population-based registry. Cause-specific mortality was categorized as death from recurrence/progression of primary disease, external causes, and non-recurrence/non-external causes (Non-Recur/Ext) (i.e., deaths from health conditions including sequelae of cancer therapy). Results: All-cause and Recurrence mortality was significantly lower in more recent eras ( Table ). No significant improvement in late mortality attributable to Non-Recur/Ext causes was seen. Additionally, all-cause mortality was significantly lower in more recent eras for 5-year survivors of ALL, AML, Hodgkin, NHL, and CNS tumors, but not neuroblastoma and Ewing's Sarcoma where an increase in cumulative incidence of late mortality was seen in more recent eras. Significant improvement in late mortality from Recurrence by era was seen in most diagnostic groups. Conclusions: All-cause late mortality has improved with more recent eras, attributable to reduced rates of mortality from progression of primary disease (i.e., durable remission). Importantly, however, efforts to reduce the toxicity of more recent therapies have not produced detectable reduction in mortality attributable to other health conditions including sequelae of cancer therapy (non-Recur/Ext causes of death), which would include death from second malignancy, cardiac and pulmonary conditions. Worsening late mortality for 5-year survivors of neuroblastoma and Ewing's sarcoma may be due to improved use of salvage therapies that delay, but do not ultimately prevent death. [Table: see text]

No significant financial relationships to disclose.

Effect of berry size and sodium hydroxide pretreatment on the drying characteristics of blueberries under infrared radiation heating

This research studied the effect of berry size and dipping pretreatment in hot sodium hydroxide (NaOH) solution on the drying characteristics of blueberries under infrared radiation (IR) heating. Changes in the microstructure and diffusion coefficient of the berries after the NaOH pretreatment were also determined using scanning electronic microscopy and dynamic vapor sorption (DVS), respectively. To quantify the effect of berry size, non-pretreated bulk blueberries were sorted into 6 groups based on their diameters and dried at 70 degrees C. To determine the effectiveness of NaOH pretreatment in improving drying characteristics, bulk blueberries of different sizes, both nonpretreated and NaOH pretreated, were dried at constant temperatures of 80 and 90 degrees C, and variable temperatures of 70 degrees C for 50 min followed by 90 degrees C for 50 min. The NaOH pretreatment dipped blueberries in 0.1% NaOH solution with fruit to solution ratio 1:1 (w/v) at initial temperature of 93 degrees C for 5 s. Results showed that the drying rate increased with decreased berry size. Average moisture diffusivity was in the range of 5.89 to 8.13 m2/s at 70 degrees C. The NaOH pretreatment increased drying rate and moisture diffusivity and reduced the number of broken berries, especially at high drying temperatures. Results from SEM observation and DVS showed that the increase in diffusivity coefficients of berry coat and loss of intact microstructure in coat and tissue cells might contribute to the effect of NaOH pretreatment on the IR drying of blueberries.

Effects on human eyes caused by experimental exposures to office dust with and without addition of aldehydes or glucan

Thirty-six volunteers (in three susceptibility groups: 11 subjects were non-allergic with nasal histamine hypersensitivity, 13 were non-allergic with normal sensitivity, and 12 were pollen allergic with or without nasal hypersensitivity) were exposed for three and a half hours in a climate chamber. Each subject was exposed to clean air (dust 45 +/- 38 microg/m(3) total suspended particle, TSP), house dust at 357 +/- 180 microg/m(3) TSP, house dust 382 +/- 175 microg/m(3) TSP with added glucan (50 ng/m(3)) and house dust 394 +/- 168 microg/m(3) TSP with added aldehydes corresponding to a gaseous phase of 300 microg/m(3) in the air. The study was explorative by nature. No significant effects of exposures as such were seen on break-up time, conjunctival epithelial damage score and Trolox Equivalent Antioxidant Capacity (TEAC) in tear film and subjective ratings. However, in TEAC a significant different time course was seen during exposures to aldehyde-containing dust indicating a subacute and late response to the exposures. Perceived eye irritation increased significantly during exposures to normal dust. The perception ratings were highly correlated, whereas no correlation was found between the subjective responses and the objective measurements.

PRACTICAL IMPLICATIONS

The findings indicate that measurement effects on the eyes are rather insensitive measures of short time effects of office dust exposures.

Endoplasmic reticulum-associated calcium regulates taxol-induced apoptosis in breast cancer cells

Abstract #4163

Background: The body eliminates unhealthy cells through programmed cell-suicide called apoptosis. Calcium (Ca2+), one of the key regulators of cell survival, is also important in regulating apoptosis. Although the chemotherapeutic agent Taxol employs apoptosis to induce cell death in breast cancer treatment, the exact mechanism of how it induces apoptosis and the role of Ca2+ in this process remain unclear. The endoplasmic reticulum (ER), the main intracellular Ca2+ store, is newly-recognized as an important gateway in apoptosis, and possibly provides a target for Taxol.&#x2028; Objective/Hypothesis: Putting these facts together, our hypothesis is that ER Ca2+ changes induced by Taxol determine breast cancer cell susceptibility to apoptosis and thus play a key role in ER-associated apoptosis. Therefore, this study investigated whether Ca2+ changes, especially associated with the ER, were generated and related to this apoptotic event.&#x2028; Study Design and Methods: For this study, we used the MDA-MB-468 breast cancer cell line. The dynamic Ca2+ changes induced by Taxol were determined in living breast cancer cells by two methods: free cytosolic Ca2+ changes were measured using Fluo4-AM Ca2+ dye; and ER Ca2+ changes were measured by a novel Ca2+ cameleon, D1ER. After inducing and evaluating Taxol-induced apoptosis in this breast cancer cell line, the effects of different Ca2+ interfering agents on the apoptotic event were tested to determine whether Taxol-induced apoptosis is Ca2+ dependent.&#x2028; Results: Taxol has a direct effect on Ca2+ homeostasis. Taxol induces a rapid ER Ca2+ release and results in a transient increase in cytosolic Ca2+ levels. A gradual ER Ca2+ depletion developed and contributed to the final sustained cytosolic Ca2+ increase. Interfering with these Ca2+ changes inhibited the Taxol-induced apoptosis, indicating that ER Ca2+ promotes Taxol-induced apoptosis.&#x2028; Relevance: It is critical to understand the process through which the widely used anticancer agent Taxol induces apoptosis. This research addressed the question of whether intracellular Ca2+ changes play a critical or marginal role in mediating Taxol-induced apoptosis. Elucidating the role of calcium in this process will not only help to clarify the mechanism of Taxol, but also aid in more effective application of Taxol in breast cancer treatment.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 4163.

Radiotherapeutic management of isolated local-regional recurrence following mastectomy

Abstract #5135

Background: Postmastectomy isolated local-regional recurrence(ILRR) remains a therapeutic challenge. This retrospective study aims to evaluate the role of radiotherapy(RT) in these patients and to analyze factors that influence local-regional control and survival.&#x2028; Methods: 255 pts with chest-wall(CW) and/or regional nodes recurrence(supraclavicular SC, axillary AXI and internal mammary nodes IMN) as first failure and received RT during 1990 and 2005 were analyzed, included 109 CW recurrence only, 114 regional nodes only and 32 pts with both, resulted in 304 recurrent sites. The median dose was 60Gy(47-74). Systemic treatment was give to 190 pts, including chemotherapy in 171, endocrine therapy(ET) in 69, and both in 41 pts.&#x2028; Results: The median disease-free interval(DFI) was 22 mo(2-260 mo), which were 37 and 17 mo in pts with positive hormonal receptor (HR) and negative HR respectively. Median follow-up was 45 mo (9 mo -15.5 yrs). The 2, 5 and 8-yr overall survival rate was 86.4%, 56.5% and 35% respectively. Median survival time after recurrence was 79 mo. The 2, 5 and 8-yr local control rate was 56.1%, 36.3% and 27.6% respectively. 79 second recurrence in the initial recurrent region and 83 subsequent recurrence in other local-regional sites were found.&#x2028; &#x2028; CW is the most common site of second recurrence. Multivariate analysis showed that no CW involvement, non-diffuse recurrence and radiation to the entire recurrent region were independent prognostic factors on local control of initial recurrent sites. ET proved to be the only independent prognostic factors on subsequent recurrence in other sites. In pts with CW recurrence, small field(67 pts) resulted in significantly lower 5-yrs local control compared to entire CW irradiation(74 pts) (33.6% vs 55.6%, p=0.023). Cox regression model found that DFI≥1yr, positive HR, solitary CW or non-supraclavicular nodal recurrence were independent favorable prognostic factors on overall survival .&#x2028; Conclusions: RT is an effective approach for ILRR after mastectomy. Radiation fields should cover the entire recurrent region. Elective irradiation to the CW in pts with nodal recurrence is recommended. Prognostic Index based on the positive multivariate analysis could be established as to stratify different prognostic sub-groups.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 5135.

Association between nucleotide excision repair gene polymorphisms and chromosomal damage in coke-oven workers

The associations between several genetic polymorphisms of nucleotide excision repair genes (NER) and chromosome damage level were studied among 140 coke-oven workers exposed to a high level of polyaromatic hydrocarbons (PAHs) and 66 non-exposed workers. Seven polymorphisms with functional potential in five NER genes (ERCC1, ERCC2, ERCC4, ERCC5 and ERCC6) were genotyped in the 206 study subjects. Multivariate analysis of covariance revealed that coke-oven workers with the ERCC1 19007 CC genotype had significantly higher cytokinesis-block micronucleus frequency (CBMN) (10.5 +/- 6.8 per thousand) than those with CT (8.1 +/- 6.6 per thousand, p = 0.01) or TT (6.6 +/- 3.7-/ per thousand p = 0.05) or CT+TT genotypes (7.5 +/- 6.3 per thousand, p = 0.004). The ERCC6 A3368G polymorphism was also associated with CBMN frequency among coke-oven workers. Subjects with the AA genotype have a significantly higher CBMN frequency (10.0 +/- 6.9 per thousand) than those with AG (6.7 +/- 4.2 per thousand, p = 0.05) or AG+GG genotypes (6.6 +/- 4.1 per thousand, p = 0.02). Stratification analysis revealed the significant associations between ERCC1 C19007T and ERCC6 A3368G, and the CBMN frequencies were only found among older workers. In addition, a significant association between ERCC2 G23591A polymorphism and CBMN frequencies was also found among older coke-oven workers. The results suggest that polymorphisms of ERCC1 C19007T, ERCC6 A3368G and ERCC2 G23591A are associated with the CBMN frequencies among coke-oven workers.

Selective hepatic vascular exclusion and Pringle maneuver: a comparative study in liver resection

OBJECTIVE

Most liver resections require champing of the hepatic pedicle (Pringle maneuver) to avoid excessive blood loss. But Pringle maneuver cannot control backflow bleeding of the hepatic vein. Resection of liver tumors involving hepatic veins may cause massive hemorrhage or air embolism from injuries of the hepatic vein. Although total hepatic vascular exclusion (THVE) can prevent bleeding of the hepatic vein effectively, it also may result in systemic hemodynamic disturbance because of the clamped inferior vena cava (IVC). SHVE, a new technique, can control the inflow and outflow of the liver without clamping the vena cava. We compared the effects of selective hepatic vascular exclusion (SHVE) and Pringle maneuver in resection of liver tumors involving the junction of the hepatic vein.

METHODS

From January 2000 to October 2005, 2100 patients with liver tumors had undergone liver resections in our department. Among them, tumors of 235 cases adhered to or were close to the junction of one or more hepatic veins. Both SHVE and Pringle maneuver were used to control blood loss during hepatectomy. These 235 cases were divided into two groups: Pringle maneuver group (110) from January 2000 to December 2002 and SHVE group (125) from January 2003 to October 2005. Data were analyzed regarding the intraoperative and postoperative courses of the patients. In the SHVE group, total SHVE (clamping the porta hepatis and all major hepatic veins) was used in 69 cases and partial SHVE (clamping the porta hepatic and one or two hepatic veins) in 56 cases. There were three methods in hepatic veins occlusion: ligating with suture, encircling and occluding with tourniquets and clamping with Satinsky clamps.

RESULTS

There was no difference between the two groups regarding the age, gender, tumor size, cirrhosis and HBsAg rate, ischemia time and operating time. Intraoperative blood loss and transfusion requirements were significantly decreased in the SHVE group. Hepatic veins rupture with massive blood loss occurred in 14 and air embolism in three during the tumor resection, but there was no massive blood loss and air embolism in the SHVE group due to hepatic vein occlusion. Postoperative bleeding, reoperation, liver failure and mortality rate were higher, and ICU stay and hospital stay were longer in the Pringle group than those in the SHVE group.

CONCLUSION

SHVE is much more effective than Pringle maneuver in controlling intraoperative bleeding. It can prevent massive blood loss and air embolism from hepatic veins rupture and can reduce the postoperative complication rate and mortality rate. Clamping the hepatic veins with Satinsky clamps is much safer and easier than ligating with suture and occluding with tourniquets.

Identification and characterization of the NTPase activity of classical swine fever virus (CSFV) nonstructural protein 3 (NS3) expressed in bacteria

The nonstructural protein 3 (NS3) of members of the family Flaviviridae possesses multiple enzyme activities that are likely to be essential for viral replication. Here, we cloned and expressed full-length CSFV NS3 protein (NS3FL) and its N-terminal truncated version (ntNS3) in E. coli. NTPase activities of the purified NS3FL and ntNS3 proteins and their reaction conditions were investigated. The results showed that CSFV NS3FL and ntNS3 proteins contained a specific polynucleotide-stimulated NTPase acitivity. Characterization of ntNS3 NTPase activity showed that optimal reaction conditions with respect to pH, MgCl2 and monovalent cations were similar to those of bovine viral diarrhea virus (BVDV) and hepatitis C virus (HCV). Site-directed mutagenesis analysis demonstrated that the GxGK(232)T to GxGAT mutation in the conserved motif I abolished the NTPase activity of ntNS3, whereas substitution of TATPA(354) for TATPV in the motif III had no effect on the enzyme activity. Moreover, the kinetic properties (K(m) and k(cat)) of CSFV NS3 were more similar to those of BVDV. Our results provide insight into the structure-function relationship of CSFV NS3 and facilitate our understanding of its role in the replication cycle of CSFV.

Long-Term Prediction of Soybean Rust Entry into the Continental United States

This special report demonstrates the feasibility of long-term prediction of intercontinental dispersal of Phakopsora pachyrhizi spores, the causal agent of the devastating Asian soybean rust (SBR) that invaded the continental United States in 2004. The climate-dispersion integrated model system used for the prediction is the combination of the particle transport and dispersion model (HYSPLIT_4) with the regional climate prediction model (MM5). The integrated model system predicts the trajectory and concentration of P. pachyrhizi spores based on three-dimensional wind advection and turbulent transport while incorporating simple viability criteria for aerial spores. The weather input of the model system is from a seasonal global climate prediction. The spore source strength and distribution were estimated from detected SBR disease severity and spread. The model system was applied to the known P. pachyrhizi spore dispersal between and within continents while focusing on the disease entry into the United States. Prediction validation using confirmed disease activity demonstrated that the model predicted the 2004 U.S. entry months in advance and reasonably forecast disease spread from the south coast states in the 2005 growing season. The model also simulated the dispersal from Africa to South America and from southern South America to Columbia across the equator. These validations indicate that the integrated model system, when furnished with detailed source distribution, can be a useful tool for P. pachyrhizi and possibly other airborne pathogen prediction.

Engineering of Bacillus subtilis for enhanced total synthesis of folic acid

We investigated whether the yield of the B vitamin folic acid could be elevated in Bacillus subtilis. Strategies for increasing the folic acid yield were investigated by employing computer-aided flux analysis and mutation. Controlling the activity of the enzyme pyruvate kinase by placing it under inducible control was one strategy devised to elevate yield while insuring that a rapid growth rate results. Other single mutation strategies included amplifying the expression of the genes in the folate operon and overexpressing the Escherichia coli aroH gene, which encodes 2-dehydro-3-deoxyphosphoheptonate aldolase. The latter could conceivably elevate the abundance of the folic acid precursor, para-aminobenzoic acid. Strains that combined two or more mutations were also constructed. Overall, a strain possessing inducible pyruvate kinase, overexpressed aroH, and increased transcription and translation of genes from the folic operon exhibited the best yield. The yield was eightfold higher than that displayed by the parent B. subtilis 168 strain.

SEB combined with IL-1ra could prolong the survival of the rat allografts in high-risk corneal transplantation

PURPOSE

To determine whether the superantigen Staphylococcal enterotoxin B (SEB) combined with interleukin-1 receptor antagonist (IL-1ra) prolong allograft survival better than individual agents in high-risk corneal transplantation in a rat model.

METHODS

Fisher 344 donor corneas were transplanted into Lewis recipients. High-risk transplantation meant that the transplants were sutured into the recipient beds with corneal neovascularization induced by placing three interrupted sutures in the host cornea. All of the recipients were divided in blinded fashion into four groups. Group I was injected with saline buffer. Group II was injected intraperitoneally with 0.2 mL SEB (75 microg/kg) at 4-day intervals on three occasions before transplantation. Group III was injected with 0.1 mL IL-1ra (1 mg/mL) subconjunctivally from the first day after transplantation for 2 weeks. Group IV received both SEB and IL-1ra. All transplants were evaluated for signs of rejection for 4 weeks after surgery. Ten days after transplantation, two recipients in each group were sacrificed for histopathological and immunological evaluation.

RESULTS

The mean survival time of the allografts in the control group was 5.89 +/- 0.79 days; in SEB group, 10.70 +/- 2.52 days; in IL-1ra group, 8.25 +/- 0.71 days; in the SEB and IL-1ra group, 17.36 +/- 2.39 days. CD4+ and CD8+ lymphocyte infiltration into the allografts and the percentage of the lymphocytes in the spleen and mandibular lymphatic nodes was significantly decreased among the treated groups with dampened lymphocyte reactivity. The SEB plus IL-1ra combination group showed the strongest inhibition.

CONCLUSION

SEB and IL-1ra are most effective in combination to treat high-risk corneal transplants.

Assessment of Epidemic Potential of Soybean Rust in the United States

This article assesses the epidemic potential of soybean rust (Phakopsora pachyrhizi) in the United States. In the assessment, there are three critical components of uncertainty: (i) suitability of climate conditions in production areas for soybean rust epidemics; (ii) likelihood of establishment of the fungus in North America; and (iii) the seasonal dispersal potential of the pathogen from overwintering regions to major soybean production regions. Assessments on the first and second components suggest soybean rust epidemics are likely in the United States, and the certainty of the third component is yet to be determined. Comparison of epidemiological factors for soybean rust in soybean production regions between China and the United States shows a complicated picture with the United States having factors that both increase and decrease risk. Future investigation of risk components-incipience in the field and long-distance dispersal-is needed.

Surface-enhanced Raman spectroscopy using silver-coated porous glass-ceramic substrates

Surface-enhanced Raman scattering (SERS) has been studied using a silver-coated porous glass-ceramic material as a new type of substrate. The porous glass-ceramic is in the CaO-TiO2-P2O5 system prepared by controlled crystallization and subsequent chemical leaching of the dense glass-ceramic, leaving a solid skeleton with pores ranging in size from 50 nm to submicrometer. Silver was coated on the surface of the porous glass-ceramic by radio frequency (RF) sputtering or e-beam evaporation in vacuum. SERS spectra of excellent quality were obtained from several dyes and carboxylic acid molecules, including rhodamine 6G, crystal violet, isonicotinic acid, and benzoic acid, using this new substrate. This new substrate showed a good compatibility with these molecules. The porous glass ceramic with a nanometer-structured surface accommodated both test molecules and silver film. The absorbed molecules were therefore better interfaced with silver for surface-enhanced Raman scattering.

Non-specific tolerance induced by staphylococcal enterotoxin B in treating high risk corneal transplantation in rats

AIMS

To explore the role of staphylococcal enterotoxin B (SEB) in treating high risk corneal keratoplasty in rats.

METHODS

Rat corneal high risk transplantation rejection models were set up using Fisher 344 and Lewis rats. The experimental rats were injected intraperitoneally with 0.2 ml SEB at different concentrations before keratoplasty. The rejection indexes of the allograft were recorded and the lymphocyte infiltration in the allograft and the percentage of the lymphocyte subpopulation in the lymphatic organs were also examined. Lymphocyte proliferation ability and the concentration of IL-2 and IL-10 in the serum were also evaluated.

RESULTS

Compared with the control group, SEB prolonged the survival time of the allograft significantly from 7 to 12 days. It could also reduce CD4(+) and CD8(+) lymphocyte infiltration in the allograft and minimise the percentage of CD4(+) and CD8(+) lymphocytes in the lymphatic organs. The lymphocyte proliferation ability was also weakened. However, the percentage of CD4(+) NK T lymphocytes in the lymphatic organs was raised. The serum concentration of IL-10 was higher but IL-2 was lower in the SEB treated groups.

CONCLUSIONS

SEB prolonged the survival time of the allograft in high risk rat corneal allo-transplantation, which may be caused by T cell deletion and acquisition of non-specific tolerance.

A convenient and rapid sample repositioning approach for atomic force microscopy

A novel repositioning approach is described for repeated observations of a specimen at a close proximal location in the atomic force microscope. The approach is similar to keystone architecture, whereby the repositioning is achieved by forming a male structured base for the specimen, and a corresponding female counterpart as the frame. For the combination of an acrylic acid frame and a metal base, 90% translation shifts are less than 10 microm, and almost all angular disorientations are within +3 degrees to -3 degrees . Nanometre-scale surface features can be relocated easily and reliably even after 40 imaging-removal-imaging cycles, dipping the specimen in solutions or heating up to 500 degrees C.