From Molecular to Multiasperity Contacts: How Roughness Bridges the Friction Scale Gap

The tangential force required to observe slip across a whole frictional interface can increase over time under a constant load, due to any combination of creep, chemical, or structural changes of the interface. In macroscopic rate-and-state models, these frictional aging processes are lumped into an ad hoc state variable. Here we explain, for a frictional system exclusively undergoing structural aging, how the macroscopic friction response emerges from the interplay between the surface roughness and the molecular motion within adsorbed monolayers. The existence of contact junctions and their friction dynamics are studied through coupled experimental and computational approaches. The former provides detailed measurements of how the friction force decays, after the stiction peak, to a steady-state value over a few nanometers of sliding distance, while the latter demonstrates how this memory distance is related to the evolution of the number of cross-surface attractive physical links, within contact junctions, between the molecules adsorbed on the rough surfaces. We also show that roughness is a sufficient condition for the appearance of structural aging. Using a unified model for friction between rough adsorbed monolayers, we show how contact junctions are a key component in structural aging and how the infrajunction molecular motion can control the macroscopic response.

Lipoteichoic acid depletion in Lactobacillus impacts cell morphology and stress response but does not abolish mercury surface binding

Lipoteichoic acid (LTA) is a key component of the cell wall of most Gram-positive bacteria and plays many structural and functional roles. In probiotic lactobacilli, the function of LTA in mediating bacteria/host cross-talk has been evidenced and it has been postulated that, owing to its anionic nature, LTA may play a role in toxic metal sequestration by these bacteria. However, studies on this last aspect employing strains unable to synthesise LTA are lacking. We have inactivated the LTA polymerase encoding gene ltaS in two different Lactobacillus plantarum strains. Analysis of LTA contents in wild-type and ltaS mutant strains corroborated the role of this gene as a major contributor to LTA synthesis in L. plantarum. The mutant strains displayed strain-dependent anomalous cell morphologies that resulted in elongated or irregular cells with aberrant septum formation. They also exhibited higher sensitivity to several stresses (osmotic and heat) and to antimicrobials that target the cell wall. The toxicity of inorganic [(Hg(II)] and organic mercury (methyl-Hg) was also increased upon ltaS mutation in a strain-dependent manner. However, the mutant strains showed 0 to 50% decrease in their capacity of Hg binding compared to their corresponding parental strains. This result suggests a partial contribution of LTA to Hg binding onto the cell surface that was dependent on the strain and the Hg form.

Determining personalized treatment by gene expression profiling in metastatic breast carcinoma patients: a pilot study

PURPOSE

The present study evaluates the massive study of gene expression in metastatic breast carcinoma (MBC) patients using microarray gene expression profiling (MAGE) complemented with conventional sequencing, immunohistochemistry (IHC) and fluorescent "in situ" hybridization (FISH), seeking to optimize the treatment in a subset of heavily pretreated patients and with limited life expectancy.

PATIENTS, MATERIAL AND METHODS

MBC patients in hormone therapy progression with survival expectancy of at least 3 months (m) have been included. The MAGE contains gene probes representing genes known to potentially interact with available drugs as cited in the literature.

RESULTS

Thirty-nine procedures were performed from October 2010 to April 2016. Within the 30 evaluable procedures, considering all hormonal manipulations as a single line, the patients had received a median of 4 treatment lines prior to MAGE (range 1-7). Progression was observed in 6 cases, stable disease (SD) in 7 cases and partial response (PR) in 16 cases, which implies a clinical benefit rate (SD + PR) of 76%. Actuarial median progression-free survival (PFS) was 6 m (95% CI 2.5-9.5) in patients with clinical benefit. The median overall survival (OS) for the entire series was 11 m (95% CI 2.2-19.8).

CONCLUSION

Data presented here indicate that the use of MAGE provides relevant information to establish personalized treatment in frail patients with limited life expectancy in which therapeutic futility is a particularly difficult burden to assume.

Effect of Unsaturation on the Adsorption and the Mechanical Behavior of Fatty Acid Layers

Adsorption, self-organization, and mechanical properties of different fatty acid layers under different confinement states have been investigated as a function of the presence and conformation of one unsaturation in their aliphatic chain. In situ characterization, at the molecular level, was performed with the ATLAS molecular tribometer, in terms of rheology, forces, and thickness of confined fluid. The results demonstrate that the fatty acids adsorb on the surfaces by weak interactions and form viscoelastic films with a thickness of about 15 Å on each surface. The adsorption kinetics, the packing of the self-assembled monolayers, and the coverage rate depend on the molecular architecture of the fatty acids and lead to various mechanical behaviors under confinement.

[Assessment of maternal satisfaction with epidural analgesia for pain control during labour]

BACKGROUND

To determine the level of satisfaction and the sociodemographic characteristics of patients who receive epidural analgesia during labour.

MATERIAL AND METHODS

A SERVQHOS questionnaire administered, with consecutive sampling, to 140 patients who had received an epidural anaesthetic for pain control during labour between January and June 2014, at the Hospital San Pedro.

RESULTS

A total of 140 questionnaires were completed. The mean overall satisfaction (SERVQHOS scale) was 4.4 with standard deviation (SD):±0.9, with the best results being obtained in the subjective ítems: (4.3; SD 0.81) compared to the objective ítems (4; SD: 0.9). The large majority (84.3%) showed satisfaction with the epidural anaesthetic, and 100% would ask for it again. No significant differences were found in epidural satisfaction or pain perception related to socioeconomic variables (age, nationality, employment conditions, education level or marital status). As regards nationality, 119 (85%) were Spanish, and 14.3% (20) of other nationalities, with 1 patient not answering the nationality question. As regards marital status, 79.3% (111) were married, 1.4% (2), single, and 2.9% (4) were widows or separated, and 2.9% (4) did not answer. The mean age was 33.3 years (SD: 4.4). Prior to the administration of the epidural anaesthetic 93.2% of the Spanish citizens group described the pain as severe compared to 95% of the other nationalities group, but this difference had no statistical significance (p=.279).

CONCLUSION

The level of satisfaction reported by the patients with this technique was high, with subjective items (good manners and trust) being appreciated more.

Evaluation of the Antioxidant Capacities and Cytotoxic Effects of Ten Parmeliaceae Lichen Species

Parmeliaceae represents the largest and widespread family of lichens and includes species that attract much interest regarding pharmacological activities, due to their production of unique secondary metabolites. The current work aimed to investigate the in vitro antioxidant and cytotoxic activities of the methanol extracts of ten Parmeliaceae species, collected in different continents. Methanol extraction afforded high phenolic content in the extracts. The antioxidant activity displayed by lichens was evaluated through chemical assays, such as the ORAC (Oxygen Radical Absorbance Capacity) and 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activities and the ferric reducing antioxidant power (FRAP). A moderately positive correlation was found between the phenolic content and the antioxidant properties for all the species: R: 0.7430 versus ORAC values, R: 0.7457 versus DPPH scavenging capacity, and R: 0.7056 versus FRAP reducing power. The methanol extract of Flavoparmelia euplecta exhibited the highest ORAC value, the extract of Myelochroa irrugans showed the maximum DPPH scavenging capacity, and Hypotrachyna cirrhata methanol extract demonstrated the highest reducing power. Further, the cytotoxic activity of the ten species was investigated on the human cancer cell lines HepG2 and MCF-7; Myelochroa irrugans exhibited the highest anticancer potential. The pharmacological activities shown here could be attributed to their phytochemical constituents.

Identification and characterization of near-fatal asthma phenotypes by cluster analysis

BACKGROUND

Near-fatal asthma (NFA) is a heterogeneous clinical entity and several profiles of patients have been described according to different clinical, pathophysiological and histological features. However, there are no previous studies that identify in a unbiased way--using statistical methods such as clusters analysis--different phenotypes of NFA. Therefore, the aim of the present study was to identify and to characterize phenotypes of near fatal asthma using a cluster analysis.

METHODS

Over a period of 2 years, 33 Spanish hospitals enrolled 179 asthmatics admitted for an episode of NFA. A cluster analysis using two-steps algorithm was performed from data of 84 of these cases.

RESULTS

The analysis defined three clusters of patients with NFA: cluster 1, the largest, including older patients with clinical and therapeutic criteria of severe asthma; cluster 2, with an high proportion of respiratory arrest (68%), impaired consciousness level (82%) and mechanical ventilation (93%); and cluster 3, which included younger patients, characterized by an insufficient anti-inflammatory treatment and frequent sensitization to Alternaria alternata and soybean.

CONCLUSIONS

These results identify specific asthma phenotypes involved in NFA, confirming in part previous findings observed in studies with a clinical approach. The identification of patients with a specific NFA phenotype could suggest interventions to prevent future severe asthma exacerbations.

Inflammatory Asthma Phenotype Discrimination Using an Electronic Nose Breath Analyzer

BACKGROUND AND OBJECTIVE

Patients with persistent asthma have different inflammatory phenotypes. The electronic nose is a new technology capable of distinguishing volatile organic compound (VOC) breath-prints in exhaled breath. The aim of the study was to investigate the capacity of electronic nose breath-print analysis to discriminate between different inflammatory asthma phenotypes (eosinophilic, neutrophilic, paucigranulocytic) determined by induced sputum in patients with persistent asthma.

METHODS

Fifty-two patients with persistent asthma were consecutively included in a cross-sectional proof-of-concept study. Inflammatory asthma phenotypes (eosinophilic, neutrophilic and paucigranulocytic) were recognized by inflammatory cell counts in induced sputum. VOC breath-prints were analyzed using the electronic nose Cyranose 320 and assessed by discriminant analysis on principal component reduction, resulting in cross-validated accuracy values. Receiver operating characteristic (ROC) curves were calculated.

RESULTS

VOC breath-prints were different in eosinophilic asthmatics compared with both neutrophilic asthmatics (accuracy 73%; P=.008; area under ROC, 0.92) and paucigranulocytic asthmatics (accuracy 74%; P=.004; area under ROC, 0.79). Likewise, neutrophilic and paucigranulocytic breath-prints were also different (accuracy 89%; P=.001; area under ROC, 0.88).

CONCLUSION

An electronic nose can discriminate inflammatory phenotypes in patients with persistent asthma in a regular clinical setting. ClinicalTrials.gov identifier: NCT02026336.

Supported TBD-assisted solution phase diversification of formyl-aza-heterocycles through alkylation-knoevenagel one pot sequences

An efficient solution-phase parallel procedure to perform the structural diversification of some formyl-nitrogen heterocycles (A) using the reusable TBD supported base is described. The library synthesis is based in a consecutive Alkylation-Knoevenagel functionalisation that uses alkyl halides (B), Michael acceptors (C) and activated methylene compounds (D) as diversity elements.

Right aortic arch with aberrant left subclavian artery and anomalous origin of right pulmonary artery from ascending aorta

The authors report a case of a neonate that was operated on with the diagnosis of right aortic arch and aberrant left subclavian artery and anomalous origin of right pulmonary artery from ascending aorta. Computed tomography (CT) scan suggested double aortic arch and cardiac catheterization suggested anomalous origin of right pulmonary artery from ascending aorta versus aorto-pulmonary window. The final diagnosis was made at the operation. There was a right aortic arch and aberrant left subclavian artery and persistent ductus arteriosus. Surgical repair consisted of section of the ductus arteriosus and reimplantation of the right pulmonary artery in the main pulmonary artery.

A novel TLR3 inhibitor encoded by African swine fever virus (ASFV)

African swine fever virus (ASFV) encodes proteins that manipulate important host antiviral mechanisms. Bioinformatic analysis of the ASFV genome revealed ORF I329L, a gene without any previous functional characterization as a possible inhibitor of TLR signaling. We demonstrate that ORF I329L encodes a highly glycosylated protein expressed in the cell membrane and on its surface. I329L also inhibited dsRNA-stimulated activation of NFκB and IRF3, two key players in innate immunity. Consistent with this, expression of I329L protein also inhibited the activation of interferon-β and CCL5. Finally, overexpression of TRIF reversed I329L-mediated inhibition of both NFκB and IRF3 activation. Our results suggest that TRIF, a key MyD88-independent adaptor molecule, is a possible target of this viral host modulation gene. The demonstration of an ASFV host evasion molecule inhibiting TLR responses is consistent with the ability of this virus to infect vertebrate and invertebrate hosts, both of which deploy innate immunity controlled by conserved TLR systems.

[Impact of melanoma diagnosis on sun protection]

INTRODUCTION

Knowledge of the dangers of sun exposure does not always lead to changes in behavior. Failure to make behavioral adjustments is of particular concern in high-risk patients.

OBJECTIVES

a) To assess the impact of melanoma diagnosis on knowledge, attitudes, and behaviors relating to sun protection, and b) to identify factors that could influence sun protection behaviors.

METHODS

A coded, anonymous questionnaire was given to 195 patients with a recent diagnosis of melanoma. Data were collected on clinical and demographic variables and on knowledge, attitudes, and behaviors relating to sun protection before and after diagnosis. The questionnaire also addressed patients' sense of distress and guilt following diagnosis.

RESULTS

Sun protection behaviors improved following diagnosis in 66% of patients. Although 98% of patients reported having received advice on sun protection following diagnosis, 15% continued to take inadequate sun protection measures. The probability of behavioral improvement following diagnosis was 4 times greater in women than in men. The subgroup of patients whose behavior improved had worse behaviors prior to diagnosis than did those who showed no improvement. Patients who expressed distress and feelings of guilt following diagnosis were more likely to improve their sun protection behavior. Age, tumor site, intensiveness of treatment, and belief that a suntan is healthy had no significant influence on behavioral change.

CONCLUSIONS

Melanoma diagnosis is associated with increased knowledge of sun protection measures and improvement in behaviors. Nevertheless, patients continue to use inadequate sun protection measures. Identification of barriers to optimal sun protection behavior may be instrumental in designing targeted educational campaigns.

HPLC isolation of antioxidant constituents from Xanthoparmelia spp

A chromatographic method is described for the purification and characterization of secondary lichen substances with biological activity. A simple reversed-phase high-performance liquid chromatography method with gradient elution has been developed that allows the determination and isolation of salazinic, usnic and stictic acids from lichen samples in a single run and the quantification of every acid in the tested extracts. The antioxidant activity of both the isolated compounds and the respective lichen belonging to Xanthoparmelia genus was determined by the Oxygen Radical Absorbance Capacity (ORAC) assay; their effect as free radical scavengers, effect on cell survival by the 3(4,5-dimethyltiazol-2-yl)-2,5-diphenyltetrazolium reduction assay and 2',7'-dichlorofluorescin diacetate method were tested on U373 MG human astrocytome cell line. Both lichens extracts and all isolated compounds protected U373 MG cells from hydrogen peroxide-induced damage, suggesting that they could act as antioxidant agents in those neurodegenerative disorders associated with oxidative damage, such as Alzheimer's disease and Parkinson's disease.

[Key diagnostic features and treatment of subungual glomus tumor]

Glomus tumor was first described by Wood in 1812 and named as such by Masson in 1924. It is a rare benign vascular tumor of the neuromyoarterial glomus. The triad of cold intolerance, intense paroxysmal pain, and well-defined site of pain is characteristic of the tumor. Approximately 80 % of lesions are found on the upper limbs, mostly under the nails. Between 2005 and 2008, 7 patients with this disease were seen in our department. Diagnosis was confirmed by histology after excision. We review the clinical features, complementary diagnostic tests, and main surgical techniques described.

Treatment of advanced non-small cell lung cancer (NSCLC) with a biweekly schedule of irinotecan (I), paclitaxel, and cisplatinum (P): A phase II study

e19076

Background: Irinotecan, paclitaxel (taxol, T), and cisplatinum are among the most active agents in the treatment of NSCLC, given alone as single agents or in combination. Based in previous data (Proc ASCO 2003 # 2816), we performed a confirmatory phase II study of the activity of a bi-weekly combination of I (120 mg/m2), T(60 mg/m2) and P (40 mg/m2) in advanced NSCLC. Methods: Forty-three patients (pts) (37 male, 6 female) with histologically proven IIIA-IV NSCLC were treated at our institution. Median age was 61 years (33–79). All pts were ECOG 0–2. 14 pts had locally advanced disease (8 IIIA, 6 IIIB) and 29 metastatic disease. Previous treatments included surgery (5 pts), radiotherapy (4 pts), chemotherapy (5 pts), surgery + radiotherapy (3 pts) and surgery + chemotherapy (2 pt). In three cases, treatment was administered as adjuvant after resection of a primary (2 cases) or a metastatic tumor (1 case). Results: A total of 299 courses were administered (median 6, range 2–14). Toxic episodes grade III-IV were neutropenic fever (10/299; 3.3%), anemia (1/299; 0.3%), asthenia (3/299; 1%), diarrhea (5/299; 17%), hemorrhagic colitis (1/299; 0.3%), mucositis (2/299, 0.6%), vomiting (4/299; 1.3%) and peripheral neuropathy (1/299; 0.3%). With a median follow-up of 72 months (9–97), 2 pts (4.6%) presented pathological complete response, 26 (60%) partial response, 11 (25%) stable disease and 1 pt progressed. Four partial responders were rendered free of disease after rescue surgery. Median time to progression was 6 months. Median survival was 10 months. The actuarial 2 and 5-year overall survival are 26% and 13% respectively. Conclusions: I, T and P at the referred doses can be safely administered in a bi-weekly basis, with a good tolerance and response rate in advanced NSCLC pts.

No significant financial relationships to disclose.

Study of the evolution of the shear stress on the restenosis after coronary angioplasty

In this article, we analyze the influence of fluid dynamics variables on the development of obstructive coronary artery disease in the medium term after percutaneous coronary intervention with stent implantation. We have analyzed a group of seven patients and the study is focused on the mid-right coronary artery. In these patients we have studied the relationship between wall shear stress and arterial wall thickness both immediately after stent implantation and six months later. The realistic three-dimensional (3D) reconstruction of the arteries is performed with the data obtained with intravascular ultrasound (IVUS) and angiography. The commercial code Fluent is used to solve the Navier-Stokes equations. Special attention is paid to the shear stress on the wall arteries and the corresponding thickness. The results show that there is a negative correlation for most of the cases between the wall shear stress and increase in wall thickness. A model is proposed to study the instability at the wall, and qualitative agreement is found.

Hydrodynamic liver gene transfer mechanism involves transient sinusoidal blood stasis and massive hepatocyte endocytic vesicles

The present study contributes to clarify the mechanism underlying the high efficacy of hepatocyte gene transfer mediated by hydrodynamic injection. Gene transfer experiments were performed employing the hAAT gene, and the efficacy and differential identification in mouse plasma of human transgene versus mouse gene was assessed by ELISA and proteomic procedures, respectively. By applying different experimental strategies such as cumulative dose-response efficacy, hemodynamic changes reflected by venous pressures, intravital microscopy, and morphological changes established by transmission electron microscopy, we found that: (a) cumulative multiple doses of transgene by hydrodynamic injection are efficient and well tolerated, resulting in therapeutic plasma levels of hAAT; (b) hydrodynamic injection mediates a transient inversion of intrahepatic blood flow, with circulatory stasis for a few minutes mainly in pericentral vein sinusoids; (c) transmission electron microscopy shows hydrodynamic injection to promote massive megafluid endocytic vesicles among hepatocytes around the central vein but not in hepatocytes around the periportal vein. We suggest that the mechanism of hydrodynamic liver gene transfer involves transient inversion of intrahepatic flow, sinusoidal blood stasis, and massive fluid endocytic vesicles in pericentral vein hepatocytes.

Bubble oscillation and inertial cavitation in viscoelastic fluids

Non-linear acoustic oscillations of gas bubbles immersed in viscoelastic fluids are theoretically studied. The problem is formulated by considering a constitutive equation of differential type with an interpolated time derivative. With the aid of this rheological model, fluid elasticity, shear thinning viscosity and extensional viscosity effects may be taken into account. Bubble radius evolution in time is analyzed and it is found that the amplitude of the bubble oscillations grows drastically as the Deborah number (the ratio between the relaxation time of the fluid and the characteristic time of the flow) increases, so that, even for moderate values of the external pressure amplitude, the behavior may become chaotic. The quantitative influence of the rheological fluid properties on the pressure thresholds for inertial cavitation is investigated. Pressure thresholds values in terms of the Deborah number for systems of interest in ultrasonic biomedical applications, are provided. It is found that these critical pressure amplitudes are clearly reduced as the Deborah number is increased.

Estudio morfométrico mediante técnicas de imagen de la vena de Trolard en su anastomosis al seno longitudinal superior

OBJECTIVE

The main objective of this work is to allow the anatomical localization of the vein of Trolard (VT) or great anastomotic vein, before neurosurgical approaches to the parietal region.

MATERIAL AND METHODS

Thirty four patients were subjected to cerebral angiography. Measurements of different points related to the anatomy of the vein were taken in 41 studies on the lateral projection. A statistical analysis was performed.

CONCLUSIONS

The measures obtained are of practical utility to locate the final portion of the vein of Trolard in its anastomotis to the sagittal superior sinus (SLS) for planning neurosurgical approaches to the parietal region.

Long-term therapeutic levels of human alpha-1 antitrypsin in plasma after hydrodynamic injection of nonviral DNA

The transfection efficacy of several vectors containing the full genomic hAAT gene with its natural promoter (pTG7101) and others containing the cDNA of hAAT gene driven by cytomegalovirus immediate-early promoter or the 0.5 kb upstream of hAAT gene sequence has been studied by hydrodynamic tail-vein injection (20 microg/mouse). pTG7101 (but not the other plasmids) results in therapeutic and stable concentration of hAAT in plasma. A dose-response study with this plasmid (0.3-320 microg/mouse) confirms that hAAT remains long-term stable in plasma, with therapeutic concentrations of hAAT (>0.9 mg/ml). The parameters of the dose-response curve were: R: 0.98, E(max) 3449.0+/- 279.7 microg/ml and EC(50) 1.2 x 10(12) plasmid-gene units. In addition, 4 months after transfection, the intrinsic efficacy of transgenic expression (amount of RNA/DNA) in mouse liver was 50-80% that normally expressed by the mouse gene. The important efficacy of nonviral genomic DNA opens a new avenue in the safety applications of human gene therapy.

[Clinical predictors of the presence of perfusion defects in more than than one territory in myocardial scintigraphy with GATED-SPECT]

BACKGROUND AND OBJECTIVE

Extension of perfusion defects is associated with outcome in patients undergoing myocardial scintigraphy. The study aimed to identify the clinical characteristics that can predict the existence of perfusion defects in more than one territory in patients referred for myocardial scintigraphy with GATED-SPECT.

PATIENTS AND METHODS

A total of 193 patients undergoing myocardial scintigraphy with GATED-SPECT (99mTc-tetrofosmine) were studied. Clinical variables and scintigraphy results were studied to determine what clinical variables are associated with perfusion defects in more than one territory.

RESULTS

The number of territories with perfusion defects per patient was 1.1 0.8 and 29% had perfusion defects in > 1 territory. Patients with greater probability of having perfusion defects in > 1 territory were those with previous myocardial infarction (44% vs 21%, p = 0.030) and males (33% vs 10%, p = 0.006). In addition, patients with > 2 coronary risk factors had a statistical tendency to have defects in > 1 territory (47% vs 20%, p = 0.057). Only 15% of the patients with one of these three characteristics had perfusion defects in > 1 territory in comparison with 45% and 83% in those with 2 or 3 factors, respectively.

CONCLUSION

Considering 3 simple clinical characteristics (male gender, previous infarction and existence of > 2 coronary risk factors), it is possible to predict which patients are more likely to show perfusion defects in > 1 territory during GATED-SPECT myocardial scintigraphy.

[Diagnostic value of gated-SPECT for each coronary artery in patients clinically diagnosed of coronary heart disease]

This study aimed to evaluate the diagnostic value of gated-SPECT for each coronary artery in patients with clinical diagnosis or suspicion of coronary heart disease.

PATIENTS AND METHODS

The study population is made up of 43 patients (64 9 years, 88% male gender) with prior clinical diagnosis or suspicion of coronary heart disease who had undergone gated-SPECT (99mTc-tetrofosmin) and cardiac catheterization. Scintigraphic study after exercise treadmill test and rest study were performed on the same day.

RESULTS

Gated-SPECT showed perfusion defects in 86% of patients, the mean number of territories with perfusion defects being 1.58 +/- 0.79. A total of 39 (91%) of the 43 patients had significant coronary heart disease. Single, two- and three-vessel disease was demonstrated in 12 (28%), 15 (35%) and 12 (28%) patients, respectively. Sensitivity and specificity were 81% and 91%, respectively, for left anterior descending artery, 88% and 65% for right coronary artery, and 55% and 81% for circumflex one.

CONCLUSIONS

Myocardial scintigraphy with gated-SPECT offers high sensitivity and specificity for the diagnosis of left anterior descending artery disease. However, sensitivity for circumflex artery and specificity for right coronary artery were low in our series.

Helicobacter pylori infection: epidemiology, pathophysiology, and therapy

Helicobacter pylori is one of the most commonly encountered human pathogens. It has been shown to be closely associated with peptic ulcer disease (PUD), gastric adenocarcinoma, and the gastric mucosa-associated lymphoid tissue (MALT) that may lead to gastric lymphoma. The current diagnostic methods include histology, microbiological culture, classic serology, urease activity detection, polymerase chain reaction (PCR) and stool antigen detection. Its treatment modality options are multiple; however, a triple regimen consisting of a proton pump inhibitor (PPI), and two antibiotics for 10 to 14 days is preferred. Drug resistance is a growing problem in this organism and new therapeutic options are currently limited.

Stability of PEI-DNA and DOTAP-DNA complexes: effect of alkaline pH, heparin and serum

DNA complexes formed with nonviral vectors such as polyethylenimine (PEI) or 1,2-dioleoyl-3-trimethylammonium-propane (DOTAP) are widely used in gene therapy. These complexes prevent the interaction of DNA with the fluorescent probes usually employed to quantify DNA. We thus studied the procedures for DNA quantification from DNA complexes as well as their stability in the presence of DNase or mouse, rat and human sera. Release of the DNA from its complexes was accomplished by increasing the pH of the medium (from 7.3 to 13.4) or by adding heparin. The stability against degradation was tested in vitro, by incubating the complexes at 37 degrees C in the presence of DNase I and sera from the three species. Both high pH and heparin were able to release DNA from its complexes. Naked DNA formed aggregates with serum proteins that delayed electrophoresis migration, and this effect was reversed in the presence of heparin. However, these aggregates did not protect DNA from digestion by serum DNase, and the DNA digesting ability of serum was: mouse>rat>human. The DNA from the complexes was resistant to degradation by DNase I, although a low proportion of DNA from the complexes was partially digested, as determined by electrophoresis. In contrast, PEI-DNA and DOTAP-DNA complexes were stable in the presence of all sera. Heparin and high pH release DNA from its complexes. The order of DNA degradation is: mouse>rat>human, but DOTAP and PEI avoid degradation of DNA by serum compounds.

Effect of dopamine on platelet activating factor induced-pulmonary edema in isolated and perfused rabbit lungs

The effect of dopamine over pulmonary edema induced by PAF was studied. Thirty preparations of rabbit lungs were used: six control preparations (CP), six PAF preparations (PP) in which we injected a dose of 1 microg/kg of rabbit weight and eighteen dopamine preparations (DAP) divided in three groups of six pretreated with a dose of 1-5 (dopaminergic range), 10-20 (Beta range) and 20-30 ug/kg/min (Alpha range) of dopamine, respectively for 30 min, followed by an injection of PAF as in the PP. DAP at Beta and Alpha-adrenergic range decreased pulmonary artery pressure (Pap) as compared to CP, with values of 11.66 (CI 95%: 10.83-12.48), 11.66 (CI 95%: 9.87-13.44) versus 17.12 (CI 95%: 16.12-18.11) cm of water, respectively. DAP in Beta and Alpha-adrenergic range prevented Pap increment as compared to PP, with values of 17.16 (CI 95%: 16.37-17.94), 17.5 (CI 95%: 14.93-20.06) versus 84 cm of water (CI 95%: 71.41-96.58), respectively. Dopamine, at its three ranges inhibited the augmentation of the fluid filtration rate observed in PP with values of 1.01 (CI 95%: 0.77-1.24), 0.03 (CI 95%: 0.01-0.04) and 0.02 g/min (CI 95%: -0.0004-0.03) versus 2.13 g/min (CI 95%: 1.56-2.69), respectively. We concluded that dopamine has a vasodilator effect on Pap and exerts an inhibiting action over PAF effects in pulmonary circulation. Such effects seem to be mainly mediated by Beta-receptors, rather than by dopaminergic receptors.

Asialofetuin liposome-mediated human alpha1-antitrypsin gene transfer in vivo results in stationary long-term gene expression

The development of nonviral vectors for in vivo gene delivery to hepatocytes is an interesting topic in view of their safety and tremendous gene therapy potential. Since cationic liposomes and liposome uptake by receptor-mediated mechanisms could offer advantages in the efficacy of liposome-mediated gene transfer, we studied the effect of liposome charge (anionic vs. cationic) and the covalently coupled asialofetuin ligand on the liposome surface in mediating human alpha1-antitrypsin (hAAT) gene transfer to mice in vivo. The changes in liposome charge were made by adding the following lipids to the backbone liposomes: anionic phosphatidylserine, cationic N-[1-(2,3-dioleoyloxy)propyl]-N,N,N-trimethyl-ammonium methylsulfate or a lipopeptide synthesized from dipalmitoylphosphatidylethanolamine and covalently coupled to the cationic nuclear localization signal peptide. Two plasmids containing the hAAT gene were used: pTG7101, containing the complete genomic sequence of the human gene driven by the natural promoter, and p216, containing the human hAAT cDNA under the control of the CMV promoter. The results indicate that both untargeted anionic and cationic liposomes mediate plasma levels of hAAT that decline over time. However, asialofetuin liposomes increase the plasma levels of hAAT and can mediate long-term gene expression (>12 months) with stationary plasma levels of protein. Results from quantitative and qualitative reverse transcriptase polymerase chain reaction match those from protein plasma levels and confirm both the human origin of the message and the liver as source of the protein. The use of asialofetuin liposomes in hepatic gene therapy may both increase and prolong in vivo gene expression of hAAT and other clinically important genes.

Antitumor effect of B16 melanoma cells genetically modified with the angiogenesis inhibitor rnasin

The growth of new blood vessels is an essential condition for the development of tumors with a diameter greater than 1-2 mm and also for their metastatic dissemination. RNasin, the placental ribonuclease inhibitor, is known to have antiangiogenic activity through the inhibition of angiogenin and basic fibroblast growth factor. Nevertheless, the administration of the recombinant form of a protein poses several limitations; as a result, we have studied the antitumor effect of RNasin in a murine gene therapy model. RNasin cDNA was subcloned into the pcDNA3 expression vector, and the resulting recombinant plasmid was used to transfect the B16 murine melanoma cell line. An RNasin inverted construction was used as control. Mice intravenously injected with clones expressing RNasin showed a significant inhibition of tumor metastatic progression with respect to control groups (P<.001) and survived longer (P<.001). Tissue sections from RNasin-expressing cell tumors showed a lower number of blood vessels when compared to tissue sections from mice lungs that had been inoculated with control cell lines. The results of these experiments show that the genetic modification of tumor cells with RNasin cDNA yields a significant antitumor effect, and suggest that this effect is at least partially the result of angiogenesis inhibition.