Mast cells are activated by Leishmania mexicana LPG and regulate the disease outcome depending on the genetic background of the host

The regulatory effect of mast cells on the pathogenesis of leishmaniasis is unclear. We report a comparative analysis of TLR2 membrane expression, TNF-α, IL-10 and MIP-1α production, and granule release of bone marrow-derived mast cells (BMMCs) from susceptible BALB/c and resistant C57BL/6 mice, stimulated in vitro with Leishmania mexicana lipophosphoglycan (LPG). We studied the kinetics of mast cell degranulation and parasite numbers in lesions of both mouse strains infected with L. mexicana. We found that BMMCs of C57BL/6 mice expressed more TLR2 and produced higher levels of both cytokines and MIP-1α, whereas BALB/c BMMCs significantly augmented their granule release. Lesions of BALB/c mice showed higher levels of degranulated mast cells at 3 h of infection, whereas after 3 days of infection, the number of degranulated mast cells in C57BL/6 was higher than in BALB/c lesions. Throughout infection, BALB/c mice harboured more parasites. The regulatory effect of mast cells seems to depend on the genetic background of the host: mast cells of BALB/c mice facilitate disease progression due to an augmented inflammatory response early in the infection, whereas mast cells of C57BL/6 mice produce cytokines that regulate inflammation and maintain an elevated number of immune cells in the lesions, promoting disease control.

Involvement of lipid rafts in the localization and dysfunction effect of the antitumor ether phospholipid edelfosine in mitochondria

Lipid rafts and mitochondria are promising targets in cancer therapy. The synthetic antitumor alkyl-lysophospholipid analog edelfosine (1-O-octadecyl-2-O-methyl-rac-glycero-3-phosphocholine) has been reported to target lipid rafts. Here, we have found that edelfosine induced loss of mitochondrial membrane potential and apoptosis in human cervical carcinoma HeLa cells, both responses being abrogated by Bcl-x_L overexpression. We synthesized a number of new fluorescent edelfosine analogs, which preserved the proapoptotic activity of the parent drug, and colocalized with mitochondria in HeLa cells. Edelfosine induced swelling in isolated mitochondria, indicating an increase in mitochondrial membrane permeability. This mitochondrial swelling was independent of reactive oxygen species generation. A structurally related inactive analog was unable to promote mitochondrial swelling, highlighting the importance of edelfosine molecular structure in its effect on mitochondria. Raft disruption inhibited mitochondrial localization of the drug in cells and edelfosine-induced swelling in isolated mitochondria. Edelfosine promoted a redistribution of lipid rafts from the plasma membrane to mitochondria, suggesting a raft-mediated link between plasma membrane and mitochondria. Our data suggest that direct interaction of edelfosine with mitochondria eventually leads to mitochondrial dysfunction and apoptosis. These observations unveil a new framework in cancer chemotherapy that involves a link between lipid rafts and mitochondria in the mechanism of action of an antitumor drug, thus opening new avenues for cancer treatment.

Candiduria in renal transplant recipients: incidence, clinical repercussion, and treatment indication

INTRODUCTION

The incidence of candiduria in renal transplant recipients is unknown. In clinical practice, the indications for antifungal therapy are not well established. Furthermore, there is the problem of the choice of the antifungal drug since some of them may select resistant Candida species, or interact with immunosuppressive agents or only be used intravenously.

AIM

We sought to study the incidence, clinical repercussions and effectiveness of antifungal treatment to prevent recurrence of candiduria.

MATERIALS AND METHODS

We examined all episodes of Candida-positive urine cultures (>50,000 cfu/mL) in 996 recipients over 2 years. We considered the Candida species, administered treatment, presence of fever, requirement for hospital admission versus outpatient case, occurrence of simultaneous bacterial urinary tract infection (UTI), antibiotic use during the week before candiduria, and presence of an indwelling urinary catheter.

RESULTS

Among 996 subjects, 34 displayed 83 episodes of candiduria, yielding an accumulated incidence of 3.4% after 2 years. The frequency was higher among women (6.3% vs 1.7%, P<.001). Of the 45 outpatient episodes (54.2%), 17 were treated and one required hospitalization (5.9%). Of the 28 nontreated outpatients, two were hospitalized (7.1%, P=.68 vs treated patients). All cases of hospital admission presented simultaneous bacterial UTI, none developed candidemia, and two patients did not receive any antifungal therapy. With respect to the first episodes of each patient (n=34), 5/11 treated (45.5%) and 4/23 untreated (17.4%) patients developed recurrences (P=.095). Selection of more resistant Candida species was not observed. Fifty cases (60%) were associated with antibiotic therapy and 34 (41%) the presence of a urinary catheter.

CONCLUSIONS

It does not seem necessary to treat candiduria in this setting. Antifungal therapy was not associated with either a reduction in recurrence or the appearance of more resistant species in this study. We observed no important clinical repercussions.

Source and impact of lead contamination on δ-aminolevulinic acid dehydratase activity in several marine bivalve species along the Gulf of Cadiz

Coastal areas and estuaries are particularly sensitive to metal contamination from anthropogenic sources and in the last few decades the study of space-time distribution and variation of metals has been extensively researched. The Gulf of Cadiz is no exception, with several rivers draining one of the largest concentrations of sulphide deposits in the world, the Iberian Pyrite Belt (IPB). Of these rivers, the Guadiana, one of the most important in the Iberian Peninsula, together with smaller rivers like the Tinto and Odiel, delivers a very high metal load to the adjacent coastal areas. The purpose of this work was to study the source and impact of lead (Pb) drained from historical or active mining areas in the IPB on the activity of a Pb inhibited enzyme (δ-aminolevulinic acid dehydratase, ALAD) in several bivalve species along the Gulf of Cadiz. Seven marine species (Chamelea gallina, Mactra corallina, Donax trunculus, Cerastoderma edule, Mytilus galloprovincialis, Scrobicularia plana and Crassostrea angulata) were collected at 12 sites from Mazagón, near the mouth of the rivers Tinto and Odiel (Spain), to Cacela Velha (Ria Formosa lagoon system, Portugal). Lead concentrations, ALAD activity and lead isotope ratios ((206)Pb/(204)Pb, (207)Pb/(204)Pb and (208)Pb/(204)Pb) were determined in the whole soft tissues. The highest Pb concentrations were determined in S. plana (3.50±1.09 μg g(-1) Pb d.w.) and D. trunculus (1.95±0.10 μg g(-1) Pb d.w.), while M. galloprovincialis and C. angulata showed the lowest Pb levels (<0.38 μg g(-1) Pb d.w.). In general, ALAD activity is negatively correlated with total Pb concentration. However this relationship is species dependent (e.g. linear for C. gallina ALAD=-0.36[Pb]+0.79; r=0.837; or exponential for M. galloprovincialis ALAD=2.48e(-8.3[Pb]); r=0.911). This indicates that ALAD activity has considerable potential as a biomarker of Pb and moreover, in marine bivalve species with different feeding habits. Lead isotope data showed significant seasonal and spatial changes in bivalve isotopic composition reflecting seasonal and geographic differences in bioaccumulation. Within the study area, Pb can be modelled as a mixing between geogenic Pb and mine-related, discharges of Pb from the IPB. For some sites at the mouth of the Guadiana River, the bivalves show contamination from other anthropogenic sources, such as leaded boat/aviation fuel and/or leaded paint. Finally, the study demonstrates convincingly the need to consider species-specific variation when using bivalve ALAD activity as a biomarker for Pb.

Simultaneous resolution of reactive radioactive decay, non-isothermal flow, and migration with application to the performance assessment for HLW repositories

Radioactive decay is an important subject to take into account when studying the thermo-hydro-dynamic behavior of the buffer clay material used in the containment of radioactive waste. The modern concepts for the multibarrier design of a repository of high level waste in deep geologic formations consider that once canisters have failed, the buffer clay material must ensure the retention and/or delay of radionuclides within the time framework given in the assessment studies. Within the clay buffer, different chemical species are retarded/fixed according to several physicochemical processes (ion exchange, surface complexation, precipitation, matrix diffusion, ...) but typical approaches do not consider the eventuality that radioactive species change their chemical nature (i.e. phase) thereby affecting their reactive behavior.

The radioactive decay of an element takes place independently of the phase (aqueous, solid or gaseous) to which it belongs. This means that, in terms of radionuclide fixation, some geochemical processes will be effective scavengers (for instance mineral precipitation of crystal growth) while others will not (for instance ion exchange and/or sorption).

In this contribution we present a reactive radioactive decay model of any number of chemical components including those that belong to decay series. The model, which is named FLOW-DECAY, also takes into account flow and isotopic migration and it has been applied considering a hypothetical model scenario provided by the project ENRESA 2000 and direct comparison with the results generated by the probabilistic code GoldSim. Results indicate that FLOW-DECAY may simulate the decay processes in a similar way that GoldSim, being the differences related to factors associated to code architecture.

[Demographic distribution and prevalence of overactive bladder in Venezuela]

OBJECTIVE

There is a lack of information regarding overactive bladder (OAB) in South America. Our aim in this study was to estimate the prevalence of overactive bladder (OAB) in Venezuela based on the 2002 International Continence Society (ICS) consensus criteria and also to verify its demographic distribution in this country.

SUBJECTS AND METHODS

We performed a multicentric prospective evaluation of patients from 2003 to 2007 in different cities in Venezuela. A number 3.407 adults (M:38%, F:62%) between 18 and 75 years of age (mean age 54 years) completed a physician guided questionnaire (V8) of urinary symptoms, bladder function, diet, general habits and general medical condition. Statistical procedures were carried out using software based on R programming for computational statistics.

RESULTS

The overall prevalence of OAB in Venezuela was determined as 21%. Female were more affected as compared to male (25.6% vs. 13.7% in men, p < 0.005) OAB was detected at early age (18 yrs) maintaining higher prevalence in women (M: 9%, F: 14%). In the studied cohort OAB shows its highest prevalence between the subgroup of 65 to 69 years of age. In all statistical tests the level of significance was defined as p < 0.005, with a confidence interval of 95%.

CONCLUSION

The OAB-V8 questionnaire aids to clearly identify patients with OAB symptoms. The overall prevalence of OAB in Venezuela is 21%. It is present in both genders, predominantly women and can be detected at early age.

Reduced-intensity conditioning allogeneic hematopoietic cell transplantation using oral fludarabine as part of the conditioning regimen

BACKGROUND

In 2003, oral fludarabine was introduced for the treatment of patients with hematologic malignancies as an alternative to its intravenous (i.v.) formulation. In an attempt to simplify the management of patients undergoing reduced intensity allogeneic hematopoietic transplantation, we have incorporated oral fludarabine in the conditioning regimen.

METHODS

We present a non-randomized retrospective analysis of 37 patients conditioned with oral fludarabine compared with 144 patients conditioned with the i.v. formulation. In addition to fludarabine, the conditioning regimens also included melphalan or busulfan depending on the underlying disease. Donors were HLA-matched siblings in 75% of cases and unrelated donors in the remaining 25%.

RESULTS

Eight patients (22%) receiving oral fludarabine were switched to the i.v. route because of gastrointestinal toxicity (three patients), patient preference (two patients) and physician preference (three patients). There were no statistical differences in terms of hospital admission (P=0.16), time to neutrophil engraftment (P=0.35), time to platelet engraftment (P=0.38), acute graft versus host disease rate (P=0.71) and non-relapse mortality at days +30 (P=1.0) and +100 (P=0.43).

DISCUSSION

This preliminary analysis confirms that oral fludarabine can replace its i.v. formulation as part of reduced-intensity conditioning regimens with no deleterious effect on any of the early transplantation outcomes. In addition, oral fludarabine can be more convenient for patients and caregivers, facilitating its implementation.

A new strategy of delayed long-term prophylaxis could prevent cytomegalovirus disease in (D+/R-) solid organ transplant recipients

Long-term prophylaxis against cytomegalovirus (CMV) started immediately after transplantation in (D+/R-) poses a higher risk of late-onset CMV disease. Delayed CMV prophylaxis could allow a transitory exposure of the immune system to CMV, which would let the immune system mount an adequate CMV-specific cytotoxic response in (D+/R-) patients and confer protection against CMV disease. We included all (D+/R-) solid organ transplant recipients (SOT) performed at our institution (January 3/October 6) who received CMV prophylaxis (mainly with oral valganciclovir) during 100 d. In the first period (until December 4), prophylaxis was initiated immediately after transplantation (conventional prophylaxis: CP). Since January 5, it was initiated after 14 d (delayed prophylaxis: DP). Incidence and severity of CMV disease was compared between both groups. A total of 44 SOT recipients were included (CP: 26 and DP: 18). CMV disease was diagnosed in eight patients (18%), seven of 26 (27%) in the CP group, and one of 18 (5.5%) in the DP group (p = 0.07). CMV colitis was reported in five of 26 patients in the CP group (19%), whereas there were no cases of visceral CMV disease in the DP group (p = 0.048). A 14-d delay in the beginning of long-term prophylaxis against CMV in (D+/R-) is safe and could prevent the onset of late-CMV disease.

Increasing early diagnosis of HIV through rapid testing in a street outreach program in Spain

Our goal was to analyze the results of a multicity program offering rapid HIV testing in a mobile unit in central locations. Between October 2006 and December 2007, 7138 persons were tested, providing a finger-prick blood sample and filling out a brief questionnaire while waiting for the results of the Determine((R)) test. Seventy people were classified as reactive and 3 as indeterminate. Confirmatory test results were obtained for 83.6%. Of the 56 reactive persons contacted, 2 were confirmed as negative, giving a positive predictive value of 96.6%. Those tested were primarily men (60.6%), persons with university education (47.4%), and included a large percentage of immigrants (26.2%), especially from Latin America, and 37.3% were men who have sex with men (MSM). Forty-seven percent had ever been tested for HIV. Global HIV prevalence was 0.98% (confidence interval [CI]: 0.75-1.21), 1.59%, (CI: 1.21-1.97) in men and 0.19%, (CI: 0.02-0.35) in women. In the tree analysis the high prevalence node included Latin Americans with only primary studies (study level finished at least at the age of 12). Of the 64% HIV-positive tests in 2007 with available CD4 counts, 18.75% had CD4 counts under 350. Street-based mobile units offering rapid HIV testing in selected sites, may diagnose HIV at an earlier stage of infection than clinic-based sites, and have a low rate of false-positives.

Effect of melatonin and tryptophan on humoral immunity in young and old ringdoves (Streptopelia risoria)

Melatonin is involved in the regulation of both cellular and humoral immunity. In the present study we have evaluated the effect of the oral administration of melatonin and its precursor, the amino acid tryptophan, on humoral immune response in ringdoves (Streptopelia risoria) from different age groups. Male and female ringdoves of 4-5years of age (young) and 12-14years of age (old) were used in this study. The animals received a single capsule of 300mg/kg b.w. of tryptophan (old animals) for 3 consecutive days 1h after lights on or a single oral dose (0.25 or 2.5mg/kg body weight/0.1ml per animal/day, young and old animals, respectively) of melatonin, for 3 consecutive days 1h before lights off. Blood samples were taken before beginning the treatment (basal values) and at the end of the treatment. Immunoglobulins, bactericidal and haemolytic activity were measured. Our results show that in old animals the humoral immune response was reduced with respect to the young. Both melatonin and tryptophan treatment increased the immunoglobulin concentration, with the nocturnal values being significantly higher than diurnal values and with a major effect in old animals. The bactericidal activity of the S. risoria serum against Staphylococcus aureus, after the treatment with melatonin or tryptophan, was increased at night with a greater effect in old animals. No significant differences were observed in the haemolytic activity of the serum in young animals, but there was an increase in old animals, with higher values at night after treatment with melatonin. In general, the oral administration of melatonin or tryptophan produced a stimulation of humoral immune response with greater effects in old ringdoves.

Outcomes of heart transplantation for cardiac amyloidosis: subanalysis of the spanish registry for heart transplantation

Amyloidosis (Am), a systemic disease, has poor prognosis because of organ damage produced by protein deposition in the extracellular space. Although heart transplantation (HTx) is possible, donor availability concerns and high mortality make this approach controversial. The Spanish Registry for Heart Transplantation includes 25 Am patients (54 +/- 9 years): 13 with AL type, 2 with AA and 10 with TTR mutation. Fifteen patients (60%) died during follow-up (4.9 +/- 1.3 years): 9 AL-Am patients, both AA-Am patients and 4 with TTR-Am. HTx survival for Am patients was similar to patients without Am at 1 month but significantly worse at 5 years: 46% versus 78% (p < 0.02). Of 10 AL-Am patients undergoing successful HTx, 4 died of systemic Am. Stem cell transplantation was performed in 3 (1 died of acute rejection). Five of 10 patients with TTR-Am underwent liver transplant; 4 remained alive at the last follow-up. Findings include poor outcome for AL-Am patients despite HTx and better survival for TTR-Am patients if HTx is associated with liver transplantation. Given the shortage of donors and poor outcome for Am patients, we would recommend that HTx be reserved for patients without or with mild systemic Am and be supplemented by additional therapies as indicated.

Microarray study of gene expression profiles in peripheral blood samples from lung cancer patients before and after erlotinib treatment

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Background: The gene expression profile in peripheral blood samples from lung cancer patients is a potential predictor to treatment response. Methods: The study has been developed using 10 healthy volunteers as the control group and 10 lung cancer patients (stage IV). Written informed consent was obtained being the protocol approved by the local Clinical Research and Ethics Committee. Peripheral blood samples were obtained from lung cancer patients before (T0) and after treatment (T15d). RNA from peripheral blood samples was extracted and purified selecting 28S/18S ratios>1.5 to obtain cDNA and cRNA for hybridization of the 20,000 genes included in Human 20K CodeLink. An array from each participant was obtained in duplicate. For each array, 2 μg of cRNA was compared to 2 μg of healthy cRNA.. Significant genes were found using Significance Analysis of Microarrays which uses repeated permutations of the data. Results: The selected genes were expressed >3-fold with a false discovery rate =0.05. Before treatment (T0) when patients were compared to healthy volunteers there was an increase in the expression of: histone 1 H4c, transforming growth factor beta 2, endothelial cell growth factor 1 (platelet-derived), glucose-6-phosphatase catalytic 2, Relaxin 3 receptor 1, Insulin-like growth factor binding protein 2, RAS-like family 11 member B, and ELK4. After treatment (T15d), when each lung cancer patient's results were compared to their own before treatment results (T0), there was an increase in the expression of: Bcl2, myosin light polypeptide 4; interferon alpha-inducible protein 27; interferon gamma receptor 1; RASSF5, ARHGEF6, IGFBP5, tumor protein p53 inducible nuclear protein 1, peroxisome proliferative activated receptor gamma. Conclusions: The data presented identifies biologically relevant over-expressed genes in lung cancer. A validation of these results and the analysis of the genes that identify patients who will respond positively to erlotinib treatment is being carried out.

No significant financial relationships to disclose.

Rituximab maintenance after R-CHOP in the first-line treatment of follicular lymphoma: A GOTEL phase II trial

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Background: Rituximab maintenance have demonstrated improvements in progression-free and overall survival in relapsed patients with follicular lymphoma (FL). Ongoing trials are evaluating the benefit of rituximab maintenance following treatment of therapy-naive patients (pts) treated with rituximab-containing chemoinmunotherapy induction regimens. Methods: The current study evaluated the activity and toxicity of rituximab maintenance after chemoinmunotherapy in the first line treatment of advanced-stage FL. Pts with advanced stage FL were eligible. The induction treatment consisted in 8 courses of chemoinmunotherapy with R-CHOP (rituximab 375 mg/m2; cyclophosphamide 750 mg/m2; doxorubicin 50 mg/m2 and vincristine 2 mg). Pts entering a complete (CR) or partial remission (PR) received maintenance with 6 doses of rituximab (375 mg/m2/d) to be given every two months after the end of induction therapy. Results: From December 2004 to November 2006, 52 pts were included. Median age was 52 years (range, 36–85) and 26 pts were women. At baseline 32 (62%) pts had stage IV and 20 (38%) stage III. According to the Follicular Lymphoma International Prognostic Index (FLIPI), 8 pts (15%) had low risk disease, 24 pts (46%) intermediate risk, and 20 pts (39%) high risk disease. Six (12%) pts did not receive maintenance (3 pts progressed during induction, 2 pts refused maintenance and 1 pt had severe toxicity to induction). Of the 46 pts included in the maintenance phase, 32 (69%) were in CR/CRu and 14 pts (31%) in PR after induction therapy. Rituximab was well tolerated in the maintenance phase. Only 5 pts didn´t receive the 6 scheduled courses (toxicity: 1; progressive disease: 2; cardiovascular events: 2). Grade 3–4 toxicity occurred as follow: neutropenia in 4 pts (9%), and fever in 1 pt (2%). No severe infections were seen. After maintenance, 40 (87%) pts were in CR/CRu, 4 pts (9%) in PR and 2 (4%) progressed. With a median follow-up of 27 months, progression-free and overall survival at 30 months were 82% and 92%, respectively. Conclusions: Rituximab maintenance after first-line R-CHOP is safe and increase the complete remission rate obtained in the induction phase.

No significant financial relationships to disclose.

Lower respiratory tract respiratory virus infections increase the risk of invasive aspergillosis after a reduced-intensity allogeneic hematopoietic SCT

We have analyzed the incidence and risk factors for the occurrence of invasive aspergillosis (IA) among 219 consecutive recipients of an allogeneic hematopoietic SCT after a reduced-intensity conditioning regimen (Allo-RIC). Twenty-seven patients developed an IA at a median of 218 days (range 24–2051) post-Allo-RIC, for a 4-year incidence of 13% (95% confidence interval 4–24%). In multivariate analysis, risk factors for developing IA were steroid therapy for moderate-to-severe graft vs host disease (GVHD) (Hazard Ratio (HR) 2.9, P=0.03), occurrence of a lower respiratory tract infection (LRTI) by a respiratory virus (RV) (HR 4.3, P<0.01) and CMV disease (HR 2.8, P=0.03). Variables that decreased survival after Allo-RIC were advanced disease phase (HR 1.9, P=0.02), steroid therapy for moderate-to-severe GVHD (HR 2.2, P<0.01), not developing chronic GVHD (HR 4.3, P<0.01), occurrence of LRTI by an RV (HR 3.4, P<0.01) and CMV disease (HR 2, P=0.01), whereas occurrence of IA had no effect on survival (P=0.5). Our results show that IA is a common infectious complication after an Allo-RIC, which occurs late post-transplant and may not have a strong effect on survival. An important observation is the possible role of LRTI by conventional RVs as risk factors for IA.

Design of a village breeding programme for a llama population in the High Andes of Bolivia

No national breeding programme for llamas is in place in Bolivia. Initiatives for genetic improvement are rarely found and are usually carried out by NGOs working in rural development or improvement of livestock production or research stations. Farmers in the Province of Ayopaya in the District of Cochabamba have formed a breeders' organization with the aim of improving fibre production. In this study, a detailed outline of a breeding programme with a focus on organizational and technical details is described. Facing constraints like illiteracy of farmers, bad infrastructure and lack of finances, a simple breeding programme is set up. The breeding goal is a higher fleece weight while keeping the fleece quality at the current high level. Greasy fleece weight and fibre diameter are identified as main selection criteria. Mass selection of males is carried out. Selected males are either exchanged between farmers and used in the herds or are kept during the mating season in a central mating station owned by the breeders' organization. Model calculations were carried out with the program zplan, which is based on a deterministic approach. zplan evaluates the genetic and economic efficiency of breeding strategies considering one cycle of selection. Scenarios with only intra-herd use, using only the central mating station or combinations of those were compared in terms of expected genetic gain and expected increase of inbreeding. Fastest genetic progress is achieved when the males are kept in a central mating station as the selection intensity is on a high level. Rates of inbreeding vary between 0.08 and 0.32% per generation.

Sorafenib inhibits MAPK-mediated proliferation in a Barrett's esophageal adenocarcinoma cell line

Esophageal adenocarcinoma continues to rise in incidence. Despite recognition of Barrett's metaplasia as the histological precursor, prognosis remains poor. The mitogen-activated protein kinases (MAPK) pathway is activated in Barrett's-associated dysplasia and adenocarcinoma and this activation is, in part, due to acid and bile acid reflux. We investigated the effects of sorafenib, an orally active Raf-inhibitor, on acid and bile acid-stimulated growth and signaling in SEG-1 cells, derived from a Barrett's esophageal cancer. SEG-1 cells were pretreated with sorafenib or vehicle and subsequently stimulated with acid or bile acid. MAPK signals, including phospho-ERK and phospho-p38, as well as cyclin D1 expression were assessed by Western blotting. Cell proliferation was measured by WST-1 colorimetric assay. Acid (pH 3.0-4.0) and bile acid (taurocholate 50-100 micromol/L) activated ERK and p38. Acid and bile acid exposure also increased levels of cyclin D1, a G1 to S cell cycle regulator. Furthermore, acid and taurocholate exposure increased cell proliferation. Sorafenib abrogated MAPK activation and cyclin D1 up-regulation and significantly inhibited cell growth. In summary, sorafenib inhibits acid or bile acid-stimulated Barrett's esophageal cancer cell proliferation by a mechanism involving the MAPK pathway. Our results suggest that sorafenib might be useful in the management of Barrett's-associated dysplasia and adenocarcinoma. These findings provide a foundation for in vivo studies to assess the efficacy of sorafenib in Barrett's-related neoplasia.

Diffusing wave spectroscopy in Maxwellian fluids

We present a critical assessment of the diffusing wave spectroscopy (DWS) technique for obtaining the characteristic lengths and for measuring the loss and storage moduli of a reasonable well-known wormlike micelle (WM) system. For this purpose, we tracked the Brownian motion of particles using DWS embedded in a Maxwellian fluid constituted by a wormlike micellar solution made of cetyltrimethylammonium bromide (CTAB), sodium salicylate (NaSal), and water. We found that the motion of particles was governed by the viscosity of the solvent at short times and by the stress relaxation mechanisms of the giant micelles at longer times. From the time evolution of the mean square displacement of particles, we could obtain for the WM solution the cage size where each particle is harmonically bound at short times, the long-time diffusion coefficient, and experimental values for the exponent that accounts for the broad spectrum of relaxation times at the plateau onset time found in the (deltar2(t)) vs. time curves. In addition, from the (deltar2(t)) vs. time curves, we obtained G'(omega) and G"(omega) for the WM solutions. All the DWS microreological information allowed us to estimate the characteristic lengths of the WM network. We compare our DWS microrheological results and characteristic lengths with those obtained with mechanical rheometers at different NaSal/CTAB concentration ratios and temperatures.

The -250G/A polymorphism in the hepatic lipase gene promoter influences the postprandial lipemic response in healthy men

BACKGROUND AND AIM

The -250G/A promoter polymorphism of the hepatic lipase gene has been associated with changes in the activity of the enzyme. We investigated whether this polymorphism modifies the postprandial response of triacylglycerol-rich lipoproteins (TRL) in young normolipemic males.

METHODS AND RESULTS

Fifty-one healthy apolipoprotein (apo) E3/E3 male volunteers (30 G/G and 21 carriers of the A allele) underwent a vitamin A fat-loading test and blood samples were drawn every hour until the 6th, and every 2h and 30 min until the 11th. Total plasma cholesterol and triacylglycerols (TG), as well as cholesterol, TG and retinyl palmitate (RP) in TRL, isolated by ultracentrifugation, were determined. Carriers of the A allele showed a higher response (P=0.008), a higher area under the curve (AUC; P=0.022) and a lower RP peak time (P=0.029) in small TRL during the postprandial response, as well as a lower peak time in total plasma TG levels (P=0.034) and large TRL-TG (P=0.033) than subjects who were homozygous for the G allele.

CONCLUSION

Our data indicate that the presence of the A allele in the -250G/A promoter polymorphism of the hepatic lipase gene is associated with a higher postprandial lipemic response.

Obesity and asthma

Asthma and obesity have a considerable impact on public health and their prevalence has increased in recent years. Numerous studies have linked these disorders. Most prospective studies show that obesity is a risk factor for asthma and have found a positive correlation between baseline body mass index and the subsequent development of asthma. Furthermore, several studies suggest that whereas weight gain increases the risk of asthma, weight loss improves the course of the illness. Different factors could explain this association. Obesity is capable of reducing pulmonary compliance, lung volumes, and the diameter of peripheral respiratory airways as well as affecting the volume of blood in the lungs and the ventilation-perfusion relationship. Furthermore, the increase in the normal functioning of adipose tissue in obese subjects leads to a systemic proinflammatory state, which produces a rise in the serum concentrations of several cytokines, the soluble fractions of their receptors, and chemokines. Many of these mediators are synthesized and secreted by cells from adipose tissue and receive the generic name of adipokines, including IL-6, IL-10, eotaxin, tumor necrosis factor-alpha, transforming growth factors-beta1, C-reactive protein, leptin, and adiponectin. Finally, specific regions of the human genome related to both asthma and obesity have been identified. Most studies point out that obesity is capable of increasing the prevalence and incidence of asthma, although this effect appears to be modest. The treatment of obese asthmatics must include a weight control program.