Expert opinion on antimicrobial therapies: is there enough scientific evidence to state that targeted therapies outperform non-targeted ones?

INTRODUCTION

Different active and passive strategies have been developed to fight against pathogenic bacteria. Those actions are undertaken to reduce the bacterial burden while minimizing the possibilities to develop not only antimicrobial resistance but also antimicrobial side-effects such as allergic or hypersensitivity reactions.

AREAS COVERED

We have reviewed preclinical results that evidence that targeted antimicrobial therapies outperform non-targeted ones. Active selective targeting against pathogenic bacteria has been achieved through the functionalization of antimicrobials, either alone or encapsulated within micro- or nanocarriers, with various recognition moieties. These moieties include peptides, aptamers, antibodies, carbohydrates, extracellular vesicles, cell membranes, infective agents, and other affinity ligands with specific bacterial tropism. Those selective ligands increase retention and enhance effectiveness reducing the side-effects and the required dose to exert the antimicrobial action at the site of infection.

EXPERT OPINION

When using targeted antimicrobial therapies not only reduced side-effects are observed, but also, compared to the administration of equivalent doses of the non-targeted drugs, a superior efficacy has been demonstrated against planktonic, sessile, and intracellular pathogenic bacterial persisters. The translation of those targeted therapies to subsequent phases of clinical development still requires the demonstration of a reduction in the probabilities for the pathogen to develop resistance when using targeted approaches.

Gold Nanoparticles Capped with a Novel Titanium(IV)-Containing Polyoxomolybdate Cluster: Selective and Enhanced Bactericidal Effect Against Escherichia coli

Bacterial infections are a public health threat of increasing concern in medical care systems; hence, the search for novel strategies to lower the use of antibiotics and their harmful effects becomes imperative. Herein, the antimicrobial performance of four polyoxometalate (POM)-stabilized gold nanoparticles (Au@POM) against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) as Gram-negative and Gram-positive bacteria models, respectively, is studied. The bactericidal studies performed, both in planktonic and sessile forms, evidence the antimicrobial potential of these hybrid nanostructures with selectivity toward Gram-negative species. In particular, the Au@GeMoTi composite with the novel [Ti2 (HGeMo7 O28 )2 ]10- POM capping ligand exhibits outstanding bactericidal efficiency with a minimum inhibitory concentration of just 3.12 µm for the E. coli strain, thus outperforming the other three Au@POM counterparts. GeMoTi represents the fourth example of a water-soluble TiIV -containing polyoxomolybdate, and among them, the first sandwich-type structure having heteroatoms in high-oxidation state. The evaluation of the bactericidal mechanisms of action points to the cell membrane hyperpolarization, disruption, and subsequent nucleotide leakage and the low cytotoxicity exerted on five different cell lines at antimicrobial doses demonstrates the antibiotic-like character. These studies highlight the successful design and development of a new POM-based nanomaterial able to eradicate Gram-negative bacteria without damaging mammalian cells.

Encapsulation of Iron-Saturated Lactoferrin for Proteolysis Protection with Preserving Iron Coordination and Sustained Release

Lactoferrin (Lf) is a globular glycoprotein found mainly in milk. It has a very high affinity for iron(III) ions, and its fully saturated form is called holoLf. The antimicrobial, antiviral, anticancer, and immunomodulatory properties of Lf have been studied extensively for the past two decades. However, to demonstrate therapeutic benefits, Lf has to be efficiently delivered to the intestinal tract in its structurally intact form. This work aimed to optimize the encapsulation of holoLf in a system based on the versatile Eudragit® RS polymer to protect Lf against the proteolytic environment of the stomach. Microparticles (MPs) with entrapped holoLf were obtained with satisfactory entrapment efficiency (90-95%), high loading capacity (9.7%), and suitable morphology (spherical without cracks or pores). Detailed studies of the Lf release from the MPs under conditions that included simulated gastric or intestinal fluids, prepared according to the 10th edition of the European Pharmacopeia, showed that MPs partially protected holoLf against enzymatic digestion and ionic iron release. The preincubation of MPs loaded with holoLf under conditions simulating the stomach environment resulted in the release of 40% of Lf from the MPs. The protein released was saturated with iron ions at 33%, was structurally intact, and its iron scavenging properties were preserved.

Elucidating the mechanisms of action of antibiotic-like ionic gold and biogenic gold nanoparticles against bacteria

The antimicrobial action of gold depends on different factors including its oxidation state in the intra- and extracellular medium, the redox potential, its ability to produce reactive oxygen species (ROS), the medium components, the properties of the targeted bacteria wall, its penetration in the bacterial cytosol, the cell membrane potential, and its interaction with intracellular components. We demonstrate that different gold species are able to induce bacterial wall damage as a result of their electrostatic interaction with the cell membrane, the promotion of ROS generation, and the consequent DNA damage. In-depth genomic and proteomic studies on Escherichia coli confirmed the superior toxicity of Au (III) vs Au (I) based on the different molecular mechanisms analyzed including oxidative stress, bacterial energetic metabolism, biosynthetic processes, and cell transport. At equivalent bactericidal doses of Au (III) and Au (I) eukaryotic cells were not as affected as bacteria did, maintaining unaffected cell viability, morphology, and focal adhesions; however, increased ROS generation and disruption in the mitochondrial membrane potential were also observed. Herein, we shed light on the antimicrobial mechanisms of ionic and biogenic gold nanoparticles against bacteria. Under selected conditions antibiotic-like ionic gold can exert a strong antimicrobial activity while being harmless to human cells.

Pharmacokinetic control on the release of antimicrobial drugs from pH-responsive electrospun wound dressings

The acidic pH of healthy skin changes during wound healing due to the exposure of the inner dermal and subcutaneous tissue and due to the potential colonization of pathogenic bacteria. In chronic non-healing wounds, the pH values vary in a wide pH range but the appearance of an alkaline shift is common. After a wound is incurred, neutral pH in the wound bed is characteristic of the activation of the cascade of regenerative and remodeling processes. In order to adjust drug release to the specific pH of the wound, herein, drug-loaded wound dressings having pH-responsiveness containing antiseptics and antibiotics and exerting different release kinetics in order to have a perfect match between the drug release kinetics, and the pH conditions of each wound type, were developed. We have fabricated drug-loaded electrospun nanofibers loaded with the antiseptic chlorhexidine, with the broad-spectrum antibiotic rifampicin, and with the antimicrobial of natural origin thymol, using the pH-dependent methacrylic acid copolymer Eudragit® L100-55, which dissolves at pH > 5.5; those drugs were loaded within Eudragit® S100, which dissolves at pH > 7 and, finally, within the methacrylic ester copolymer Eudragit® RS100 which is pH independent and slowly erodes and releases its contained cargo. The antibacterial action of those advanced wound dressings has been evaluated against methicillin-sensitive S. aureus Newman strain expressing the coral green fluorescent protein (cGFP), as a model of a Gram-positive bacteria, and against E. coli S17 strain as a model of a Gram-negative bacteria. It was demonstrated that those combinational products integrate in one device the required characteristics for a wound dressing with the therapeutic action of a contained active principle and can be selected depending on the wound acidic or alkaline status for its appropriated management.

Enhancement of the fatigue life of recycled PP by incorporation of recycled opaque PET collected from household milk bottle wastes

Opaque PET (Polyethylene terephthalate) was recently introduced as a dairy packaging, mainly for milk bottles. Opaque PET, obtained as PET filled with mineral nanoparticles, allows for a reduction of bottles' thickness, thus a cost reduction for industrials. For this reason, the use of opaque PET is steadily increasing. However, its recyclability is nowadays an issue: although the recycling channels are well established for transparent PET, the presence of opaque PET in the household wastes weakens the existing recycling channels. Besides, many initiatives are launched in Europe to turn wastes into resources, as one key to a more circular economy. One of the biggest challenges is an efficient sorting of the plastic solid wastes since the PET is not miscible with other plastics such as polypropylene (PP) from the bottle caps and polyethylene (PE) from the other milk bottles. In this work, the mechanical properties of uncompatibilized blends of opaque PET (rPET-O) with recycled polypropylene (rPP) have been studied; both are collected from household wastes. The tensile properties and the fatigue life of rPP, monitored by in-situ digital image correlation and in-situ infrared thermography, are increased by the incorporation of rPET-O. rPET-O/rPP blends may be substituted to rPP for similar applications, with no need to sort the caps from the bottles. Thus, as a concept, the incorporation of opaque PET into the PP recycling sector may be a new route to absorb some of the growing amounts of opaque PET.

Controlling Particle Size and Release Kinetics in the Sustained Delivery of Oral Antibiotics Using pH-Independent Mucoadhesive Polymers

Copolymers synthesized from acrylic acid and methacrylic acid used as gastroprotective and mucoadhesive enteric coatings have been used to prepare micro- (∼2 μm), submicro- (∼200 nm), and nanoparticles (∼20 nm) containing rifampicin (Rif) to obtain time-controlled drug release kinetics. Different particle sizes and drug release kinetics have been obtained using different synthesis conditions and fabrication techniques including the use of an electrosprayer and an interdigital microfabricated micromixer. The antimicrobial action of the encapsulated Rif has been demonstrated against Staphylococcus aureus ATCC 25923 and compared with the effect of the equivalent dose of the free macrolide antibiotic. At low concentrations, the encapsulated antibiotic showed superior antimicrobial activity than the free drug. The stability of the developed particles has been evaluated in vitro under simulated gastric and intestinal conditions. At the concentrations tested, a reduced cytotoxicity against different human cell lines was observed after analyzing their subcytotoxic doses and the influence on their cell cycle by flow cytometry. Drug release kinetics can be tuned by adjusting particle sizes, and it would be possible to reach the minimum inhibitory concentration or the minimum bactericidal concentration at different time points depending on the medical needs.

The Effect of Titanium Dioxide Surface Modification on the Dispersion, Morphology, and Mechanical Properties of Recycled PP/PET/TiO2 PBNANOs

Titanium dioxide (TiO₂) nanoparticles have recently appeared in PET waste because of the introduction of opaque PET bottles. We prepare polymer blend nanocomposites (PBNANOs) by adding hydrophilic (hphi), hydrophobic (hpho), and hydrophobically modified (hphoM) titanium dioxide (TiO₂) nanoparticles to 80rPP/20rPET recycled blends. Contact angle measurements show that the degree of hydrophilicity of TiO₂ decreases in the order hphi > hpho > hphoM. A reduction of rPET droplet size occurs with the addition of TiO₂ nanoparticles. The hydrophilic/hydrophobic balance controls the nanoparticles location. Transmission electron microscopy (TEM_ shows that hphi TiO₂ preferentially locates inside the PET droplets and hpho at both the interface and PP matrix. HphoM also locates within the PP matrix and at the interface, but large loadings (12%) can completely cover the surfaces of the droplets forming a physical barrier that avoids coalescence, leading to the formation of smaller droplets. A good correlation is found between the crystallization rate of PET (determined by DSC) and nanoparticles location, where hphi TiO₂ induces the highest PET crystallization rate. PET lamellar morphology (revealed by TEM) is also dependent on particle location. The mechanical behavior improves in the elastic regime with TiO₂ addition, but the plastic deformation of the material is limited and strongly depends on the type of TiO₂ employed.

Targeted Release of Probiotics from Enteric Microparticulated Formulations

The development of advanced probiotic delivery systems, which preserve bacteria from degradation of the gastrointestinal tract and achieve a targeted release mediated by pH-independent swelling, is of great interest to improve the efficient delivery of probiotic bacteria to the target tissue. Gram-positive and Gram-negative bacteria models (Lactobacillus acidophilus (Moro) Hansen and Mocquot (ATCC® 4356™) and Escherichia coli S17, respectively) have been successfully encapsulated for the first time in pH-independent microparticulate polymethacrylates (i.e., Eudraguard biotic) used for the targeted delivery of nutraceuticals to the colon. These bacteria have also been encapsulated within the mucoadhesive polymethacrylate Eudragit RS 100 widely used as targeted release formulation for active pharmaceutical ingredients. The enteric microparticles remained unaltered under simulated gastric conditions and released the contained viable microbial cargo under simulated intestinal conditions. Buoyancies of 90.2% and 57.3% for Eudragit and Eudraguard microparticles, respectively, and long-term stability (5 months) for the encapsulated microorganisms were found. Cytotoxicity of the microparticles formulated with both polymers was evaluated (0.5-20 mg/mL) on Caco-2 cells, showing high cytocompatibility. These results underline the suitability of the synthesized materials for the successful delivery of probiotic formulations to the target organ, highlighting for the first time the potential use of Eudraguard biotic as an effective enteric coating for the targeted delivery of probiotics.

Development of the dynamic structure (force lines) of the middle ear ossicles in human foetuses

OBJECTIVES

To study the ontogenic development of the organisation of the human middle ear ossicles structure.

MATERIAL AND METHODS

46 human temporal bones of ages varying from 32 days post-conception to newborns.

RESULTS

The development of the structural organisation of the malleus begins at 16 weeks via two cortical fascicles situated in the neck; at 21 weeks they extend towards the head, at 23 weeks to the lateral process and at 24 weeks to the handle. In the handle, the force lines are transmitted via three cardinal fascicles, two of them via the cortical fascicle and one via the centre, which starts after 29 weeks' development and is consolidated after 31 weeks. In the incus the force lines start at 16 weeks via two cortical fascicles situated in the long process, which progressively extend in a rostro-caudal direction between 17 and 20 weeks. At 21 weeks they occupy the whole extension of the long process and at 22 weeks the fusion of both cortical fascicles begins. From 30 weeks onwards it is strengthened by the crossing of bone trabeculae from one cortical to another. Two fascicles come out of the incus body, surrounding the medullary cavity and going in the direction of the short process. In the beginning, the stapes have two cortical fascicles in their crura. The remodelling process makes the internal cortical fascicle disappear and after 31 weeks all the force lines run through the external cortical fascicle. The tympanic membrane of the stapes footplate undergoes a remodelling process and after 28 weeks bony trabeculae are deposited. In newborns (40 weeks), the ossicles' structure is cavitary and has not been completed. The fan-shaped trabecular fascicle, which starts in the articular facets of the malleus and the incus, still has to develop.

Fetal development of the human tympanic ossicular chain articulations

OBJECTIVES

To obtain further knowledge on the morphogenesis of the articulations in the tympanic ossicular chain in humans.

MATERIAL AND METHODS

In 25 temporal bones of human fetuses the structural development of incudomallear, incudostapedial and stapediovestibular articulations was studied. The chronological ages were between the 7th week (21 mm) and the 29th week (270 mm).

RESULTS AND DISCUSSION

Incudomallear articulation showed diarthrosis and sellar joint characteristics. It showed a homogenous interzone in the 7th week of development, a three-layered interzone in the 8th week, the first cavitation signs in the 9th week and the presence of an articular cavity in the 10th week. The presence of a hyaline cartilage covering articular surfaces was observed starting in the 20th week of development. Incudostapedial articulation showed typical characteristics of a diarthrosis and spheroidal joint with a homogenous interzone at the 7th week, showing similar characteristics for 12 weeks, and completed its cavitation at the 16th week. We observed hyaline cartilage on articular surfaces from 29 weeks. Stapediovestibular articulation showed typical characteristics of syndesmosis. The annular ligament primordium derived from cartilage differentiation, both from stapedial footplate and from the surrounding otic capsule, into mesenchyme and its subsequent transformation into fibrous tissue, reaching definitive characteristics from the 12th week.

[Is the breath test reliable in primary care diagnosis of Helicobacter pylori infection?]

OBJECTIVE

To evaluate the reliability of the breath test urea 13C in the primary care for the diagnosis of Helicobacter pylori (Hp) infection.

DESIGN

Descriptive, prospective and multicentric.Location. Urban area belonging to the Health Center Actur Sur of Zaragoza with participation of Miguel Servet Hospital.

PARTICIPANTS

87 patients with clinical diagnosis of functional dispepsia. In all of them was made a breath test with 13C urea as well as a gastroscopy with taking of samples for histology and ureasa fast test.

MAIN MEASUREMENTS

Age, sex and the presence of positivity or negativity of infection by Hp were valued in the histology, ureasa test and in the breath test, considering the histology and the ureasa test like gold tests for this measurement, reason why it was demanded that the positive or outside negative result in both considering it nonambiguous.

RESULTS

Two cases were excluded by ambiguous results. The 77.6% (66/85) were positive by histology and ureasa test, and these, 92.4% (61/66) were positives to the breath test. The sensitivity of this test was 92% and the specificity 100%.

CONCLUSIONS

The breath test in primary care has a high value diagnosis of Hp infection, being able to avoid, in some cases, another invasives techniques like gastroscopy.

Contributions to the study of the foetal development of physiological intimal thickening in the human uterine artery

The morphological study of the development of "intimal thickenings" of the human uterine artery in physiological condition was performed on 72 uterine arteries obtained from foetuses from the 12th week of gestation up to birth. Our results indicate that intimal thickening is formed by the migration and displacement of mesenchymal cells around the site of origin of collateral vessel from uterine mesothelium. These cells firstly differentiate into the myoblasts and then into the myocites. During the development the internal limitans membrane separates the intimal thickening from the tunica media and the elastic fibres appearing inside possessing a muscle-elastic nature. The function of intimal thickenings is the regulation of local blood flow by means of the control of myocitic contractile capacity; these cells play a fundamental role in endothelium-intimal smooth muscle cell contact.

[Failure of rapid serology for Helicobacter pylori as diagnostic method in primary care consultation]

OBJECTIVE

To evaluate the validity of a rapid serology test for diagnosing Helicobacter pylori infection in our area.

DESIGN

Longitudinal, prospective study.

SETTING

Urban primary care centre.

MEASUREMENTS

As reference tests for defining the presence/absence of Helicobacter pylori, histology and the urease gastric mucous membrane test (Jatrox(R) test) were used. Both tests can be either positive or negative, without intermediate values.

RESULTS

47 consecutive patients were included. Histology (confirmed with the urease test) showed infection in 38 cases (80.85% prevalence). The results of rapid serology (95% CI) were: sensitivity 0.66 (0.51-0.81), specificity 1 (1-1), positive predictive value 1 (1-1), and negative predictive value 0.41 (0.2-0-61).

CONCLUSIONS

In a population with high prevalence of infection, a positive in the rapid serology test confirms infection. However, a negative does not discount infection, which significantly reduces the test's overall diagnostic value. This confirms in the primary care context the findings of hospital-based studies.

Contribution to the development of the stapedius muscle structure in human fetuses

The purpose of this report is to contribute to the knowledge of the morphogenesis of the human stapedius muscle. We have studied the stapedius structure development in 17 temporal bones from human fetuses. Chronological ages were from 48 days (21 mm) to 29 weeks (270 mm). Samples were fixed in 10% formol, decalcified with 2% nitric acid, embedded in Paraplast, sectioned in sequence of 7 microns and were stained with haematoxylin & eosin and Martins' trichrome. Four maturation stages were observed in the development of the stapedius muscle structure. First, the formation of the 'primordium muscularis' in the mesenchyme of the tympanic cavity (promyoblasts) was observed in a 36-mm embryo. Second, its differentiation into myoblasts, and its next cellular fusion to form muscle tubes, was seen in a 99-mm foetus. In the third stage, myofibrogenesis phenomena were developed, to synthesize, the myotube myoblasts, myofilaments, phenomena we observed that took place during the 14th to 17th weeks of development. The last stage was characterized by the presence of striated muscle fibres, at first intermingled with myotubes (18th to 26th weeks), until in the 29th week fetuses (270 mm) the skeletal muscle fibre was completely differentiated. We conclude that in the 29th week of development (270 mm) the stapedius muscle structure is completely differentiated, although the functional development is not complete until birth.

Is 1-week treatment for peptic ulcer healing sufficient and safe?

OBJECTIVE

To confirm whether 1-week anti-Helicobacter therapy to achieve ulcer healing is sufficient and safe.

METHODS

We retrospectively analyzed patients with peptic ulcer who were infected with Helicobacter pylori and treated with 3 different 7-day regimens, according to predefined protocols in 3 different centers in the same geographical area (Aragón, Spain). Three combinations commonly described in the literature were used: a) omeprazole (40 mg/24 h), tetracycline hydrochloride (2 g/24 h), colloidal bismuth subcitrate (480 mg/24 h) and metronidazole (750 mg/24 h) (OBTM, n = 105); b) omeprazole (40 mg/24 h), clarithromycin (1.5 g/24 h) and amoxicillin (3 g/24 h) (O40C1.5A3, n = 13); and c) omeprazole (40 mg/24 h), clarithromycin (1 g/24 h) and amoxicillin (2 g/24 h) (O40C1A2, n = 4). In all patients the diagnosis of peptic ulcer disease was confirmed endoscopically, and H. pylori infection was verified with urease testing and histological analysis. After treatment ended, no other antacids were allowed until after endoscopic examination to check eradication and ulcer healing.

RESULTS

122 patients were included (107 with duodenal ulcer, 12 with gastric ulcer and 3 with both). Compliance was good and side effects infrequent and mild. Eradication rates were 88.5% (93/105) in the OBTM group, 100% (13/13) with O40C1.5A3, and 75% (3/4) with O40C1A2. Healing was achieved in 98.16% (107/109) of the patients in whom the bacterial infection was eradicated, and in 23.07% (3/13) of those in whom it was not (p < 0.0001). No patient had any complications during the period without treatment.

CONCLUSIONS

1-week eradication therapy with previously described combinations commonly used in clinical practice achieves high ulcer healing rates with no complications in the period without antacid treatment. We consider that it is not necessary, at least in most patients, to prolong antacid therapy.

[Effectiveness of the eradication of Helicobacter pylori by treatment with omeprazol, amoxicillin, and clarithromycin according to dosage and administration schedule]

BACKGROUND

There are many reports that evaluate the efficacy of the combination of omeprazole, amoxicillin and clarithromycin in the eradication of Helicobacter pylori, but data about effectivity in clinical practice are sparse. The goal of our study is to evaluate the effectivity in the clinical setting of this combination with diverse durations and doses.

METHODS

This is a retrospective analysis of 187 patients (128 male and 59 female), with an endoscopic diagnosis of duodenal ulcer (156), gastric ulcer (25) and both (6) with Helicobacter pylori infection as defined by both: a positive ureasa test and histology. After diagnosis the patient were treated with one of three combinations: a) omeprazole: 20 mg/12 h + amoxicillin: 1 g/12 h + clarithromycin: 500 mg/12 h, during 6 days (n = 60); b) omeprazole: 20 mg/12 h + amoxicillin: 1 g/12 h + clarithromycin: 500 mg/12 h, during 7 days (n = 74), and c) omeprazole: 20 mg/12 h + amoxicillin: 1 g/8 h + clarithromycin: 500 mg/8 h, during 7 days (n = 53). After the 6 or 7 day treatment period the patients did not receive any further treatment until a follow-up control unit. Eradication was evaluated with one of two tests: endoscopy (with ureasa test and at least 4 histologic samples) (n = 90) or urea breath test according to european protocol (n = 97).

RESULTS

No patient dropped out because of side effects and compliance was above 80% in all cases. The global eradication rate was 87.2% (CI 95%: 82.4-92%). According to treatment the rate were respectively 80% (CI 95%: 67.7-89.2%) with scheme A; 89.2% (CI 95%: 79.8-95.2%) with scheme B, and 92.5% (CI 95%: 81.8-97.9%) with scheme C, with no statistically significant differences among groups. Difference between schemes and C, however, was almost reached (p = 0.053).

CONCLUSIONS

The combination of omeprazole, amoxicillin and clarithromycin at standard doses (scheme B) is effective in clinical practice. Higher dose of amoxicillin and clarithromycin does not improve the results, and shorter duration of therapy associated with lower, although not significant rate of eradication.

Eradication of helicobacter pylori among patients from a primary care practice

BACKGROUND

The eradication of Helicobacter pylori is becoming the therapy of choice for peptic ulcers, if the infection is present. Published data from primary care settings are, however, limited.

METHODS

An open-ended, prospective study was undertaken that included 31 patients with active peptic ulcer demonstrated by endoscopy and H pylori infection confirmed by urease and histologic tests. After a 14-day period of treatment with omeprazole, bismuth, tetracycline, and metronidazole, healing and H pylori status were evaluated by repeat endoscopy done at least 28 days after the last treatment dose. Eradication is defined as absence of H pylori in at least four (two from the fundus and two from the antrum) samples taken from the gastric mucosa and a negative urease test. Drug side effects and patient compliance were monitored in all cases.

RESULTS

Twenty-eight patients completed the protocol. Healing was obtained in all cases, and eradication was accomplished in 25 (89%). Side effects were common (69%) but mild. Compliance was good. After a mean follow-up of 300 days (range, 180 to 400), one ulcer recurrence was observed in an H pylori-positive patient and none in H pylori-negative patients.

CONCLUSIONS

The treatment of H pylori infection is an effective way of healing peptic ulcers, and can be applied in primary care settings. Further studies with more patients and with shorter and easier therapies should be undertaken to confirm our findings.

[Diffuse gastrointestinal angiodysplasia associated with cryptogenic hepatic cirrhosis and coagulopathy simulating von Willebrand disease]

Angiodysplasic lesions can be located anywhere in the gastrointestinal tract, but most of them are found in the cecum and right colon. Angiodysplasias are very infrequent in the stomach and small bowel. These lesions can be associated with several clinical conditions, such as certain coagulation disorders and liver diseases. We report the case of a diffuse gastrointestinal angiodysplasia in a female patient with idiopathic cirrhosis of the liver who developed a coagulopathy which mimicked von Willebrand disease. After repeated blood transfusions, which were not able to control the anemia of the patient, an antrectomy was performed because most lesions were located in the antrum. The procedure did not achieve a suitable control of the bleeding. Finally, a hormonal therapy combining estrogens and progestagens, was able to control, at least partially, the patient's chronic gastrointestinal bleeding.

[Primary gastric lymphoma in an HIV positive patient]

We report the case of a young male patient, VIH (+), who was admitted in our hospital with severe epigastric pain. Endoscopical and histological diagnosis was primary gastric non-Hodgkin lymphoma without Helicobacter pylori. The patient was treated with chemotherapy by CHOP scheme (6 cycles), with high clinical improvement and endoscopical and histological regression of the lesion. We comment some features of this peculiar association.