Review article: biofilm formation by Helicobacter pylori as a target for eradication of resistant infection

BACKGROUND

Helicobacter pylori is one of the most common causes of bacterial infection in humans. Resistance of this infection to conventional therapies has suggested the role of a biofilm-growing bacterium, which is recalcitrant to many antimicrobial agents.

AIM

To review the current knowledge on biofilm formation by H. pylori and to discuss the implications of this behaviour in the context of human infections and their treatment.

RESULTS

Scanning electron microscopy analysis of gastric biopsies of infected patients demonstrated that H. pylori forms biofilm on the gastric mucosa epithelium. Adaptation to the biofilm environment may produce many persister cells, namely dormant cells, which are highly tolerant to antimicrobials that could account for the recalcitrance of H. pylori infections in vivo. Resistant H. pylori infection has become increasingly common with triple or quadruple therapy, even in the presence of H. pylori strains susceptible to all antibiotics. The mucolytic and thiol-containing antioxidant N-acetylcysteine, associated with antibiotics, was successfully used in clinic for therapy of patients with chronic respiratory tract infections. Consistently, N-acetylcysteine treatment prior to starting antibiotic therapy allowed the disappearance of gastric biofilm in all patients in whom H. pylori was eradicated.

CONCLUSION

Effective strategies targeting H. pylori biofilm infections are possible, through the use of substances degrading components of the biofilm.

Reduced performance of Troponin T for acute coronary syndromes diagnosis in the elderly and very elderly patients: a retrospective study of 2688 patients

STUDY OBJECTIVE

We evaluated the performance of Troponin T (cTnT) for acute coronary syndrome (ACS) diagnosis in elder compared to younger patients.

MATERIALS AND METHODS

We retrospectively evaluated 2688 patients admitted to our Emergency Department for suspected ACS. All patients received ECG, serum creatinine determination, and serial cTnT samplings. Patients were considered positive for cTnT if they had a cTnT above our reference standard (>0.03 microg/L) in any determination obtained within 6 hours from admission. ACS diagnosis, either acute myocardial infarction or unstable angina, was based on reviewed data and discharge diagnosis hospital. Patients were divided in three groups according to age: <65-years-old, elders > or =65 and <80 years, and very elders > or =80 years. CTnT diagnostic accuracy for ACS was compared in these three groups in patients <65 years.

RESULTS

Two thousands six and hundred eighty-eight patients (35.3% female) were enrolled in this study. 1087 patients (40.4%) were <65 years old, while 1205 patients (44.8%) were >or =65 and <80 years, and 396 patients (14.8%) were > or =80 years. The overall sensitivity of cTnT for ACS diagnosis was 0.57 (CI 95% 0.54-0.60) with a specificity of 0.71 (CI 95% 0.69-0.73). In older cohorts cTnT showed a reduced performance for ACS diagnosis. Area under the receiver operating characteristic curve of abnormal cTnT for ACS was 0.70 (0.66-0.73) in <65 years, 0.61 (95% CI 0.60-0.66) in > or =65 and <80 years, and 0.59 (0.53-0.65) in > or =80 years.

CONCLUSION

Compared to younger patients cTnT showed a reduced performance for ACS diagnosis in elders > or =65 and <80 years; cTnT performance was further reduced in patients > or =80 years.

Deep sequencing of short RNAs reveals novel microRNAs in minor salivary glands of patients with Sjögren's syndrome

OBJECTIVES

Sjögren's syndrome is a complex autoimmune disease of the salivary gland with an unknown etiology, so a thorough characterization of the transcriptome would facilitate our understanding of the disease. We use ultradeep sequencing of small RNAs from patients with Sjögren's syndrome and healthy volunteers, primarily to identify and discover novel miRNA sequences that may play a role in the disease.

METHODS

Total RNA was isolated from minor salivary glands of healthy volunteers and patients with either high or low salivary flow and sequenced on the SOLiD platform. Prediction of mature miRNAs from the sequenced reads was carried out using miRanalyzer, and expression was validated using Taqman qPCR assays.

RESULTS

We validated the presence of six previously unidentified miRNA sequences in patient samples and in several cell lines. One of the validated novel miRNAs shows promise as a biomarker for salivary function.

CONCLUSION

Sequencing small RNAs in the salivary gland is largely unprecedented, but here, we show the feasibility of discovering novel miRNAs and disease biomarkers by sequencing the transcriptome.

Meniere's disease might be an autoimmune condition?

OBJECTIVES

To review our current knowledge of the pathogenesis of Meniere's disease, including viral infection and immune system-mediated mechanisms, and to discuss the pathogenesis as it relates to pharmacotherapy.

SYSTEMATIC REVIEW METHODOLOGY

Relevant publications on the aetiopathogenesis, molecular biology, genetics and histopathology of Meniere's disease from 1861 to 2011 were analysed.

RESULTS AND CONCLUSIONS

Meniere's disease is characterised by intermittent episodes of vertigo, fluctuating sensorineural hearing loss, tinnitus, and aural pressure. The aetiology and pathogenesis remain unknown. Proposed theories of causation include viral infections and immune system-mediated mechanisms. The immune response in Meniere's disease is focused on inner ear antigens. Approximately one-third of Meniere's disease cases seem to be of an autoimmune origin although the immunological mechanisms involved are not clear. The diagnosis of autoimmune inner ear disease is based either on clinical criteria or on a positive response to steroids. The antiviral approach has virtually eliminated the use of various surgical methods used in the past. Steroid responsiveness is high, and with prompt treatment, inner ear damage may be reversible. The administration of etanercept improves or stabilises symptoms in treated patients. Treatment of antiphospholipid syndrome can be directed toward preventing thromboembolic events by using antithrombotic medications. Only warfarin has been shown to be effective. Gene therapy can be used to transfer genetic material into inner ear cells using viral vectors and to protect, rescue, and even regenerate hair cells of the inner ear.

A close cut: a technical report of endovascular removal of a penetrating intravascular foreign body after a lawn mowing injury

We present a case of endovascular retrieval of a penetrating foreign body that was originally lodged in the mediastinum and then migrated to the hepatic vein. The steel nail entered the thorax and traversed the left lung causing a pneumothorax. The patient underwent a thoracotomy, but the foreign body had migrated from its original mediastinal position. A postsurgical CT showed that the object was below the right hemidiaphragm. Diagnostic venogram demonstrated that the object was in the main hepatic vein. Using a double-snare technique, the object was safely and successfully removed from the hepatic vein via the right common femoral vein.

Cadmium phytoextraction potential of different Alyssum species

This work was planned for providing useful information about the possibility of using serpentine adapted plants for phytoextraction of cadmium, element scarcely represented in such metalliferous environment. To this aim, we investigated variation in cadmium tolerance, accumulation and translocation in three Alyssum plants with different phenotypes: Alyssum bertolonii, that is a serpentine endemic nickel hyperaccumulator, and two populations of Alyssum montanum, one adapted and one not adapted to serpentine soils. Plants were hydroponically cultivated in presence of increasing concentrations of CdSO(4) for two weeks. For the metal concentration used in the experiments, the three different Alyssum populations showed variation in cadmium tolerance, accumulation and content. The serpentine adapted population of A. montanum showed statistically higher cadmium tolerance and accumulation than A. bertolonii and the population of A. montanum not adapted to serpentine soil thus deserving to be investigated for phytoextraction purposes. Furthermore, as for the kinetic parameters of the cadmium uptake system, A. montanum serpentine population presented a low apparent K(m) value, suggesting a high affinity for this metal of its uptake system, whereas the V(max) values were not significantly different among the plants. Present data revealed metallicolous plants are also suitable for the phytoremediation of metals underrepresented in the environment of their initial origin. Nonetheless, field trials on real contaminated soils are essential.

High-gain harmonic-generation free-electron laser seeded by harmonics generated in gas

The injection of a seed in a free-electron laser (FEL) amplifier reduces the saturation length and improves the longitudinal coherence. A cascaded FEL, operating in the high-gain harmonic-generation regime, allows us to extend the beneficial effects of the seed to shorter wavelengths. We report on the first operation of a high-gain harmonic-generation free-electron laser, seeded with harmonics generated in gas. The third harmonics of a Ti:sapphire laser, generated in a gas cell, has been amplified and up-converted to its second harmonic (λ(rad)=133 nm) in a FEL cascaded configuration based on a variable number of modulators and radiators. We studied the transition between coherent harmonic generation and superradiant regime, optimizing the laser performances with respect to the number of modulators and radiators.

Response to anti-TNF-α treatment for secondary renal amyloidosis in a patient with ankylosing spondylitis

Renal amyloidosis is a complication of ankylosing spondylitis. A possible pathogenetic role is due to TNF-alpha, with a direct action on glomerular receptors TNFR2 and renal injury, secondary to deposition of amyloid fibrils. The most frequent clinical manifestation is proteinuria or nephrotic syndrome. Etanercept, a soluble receptor of TNF-alpha, binds this circulant cytokine with a progressive improvement of renal function and reduction of deposits of amyloid. Transient leukopenia, observed during ankylosing spondylitis, should not be considered a controindication to the use of Etanercept, but it requires a constant monitoring. The benefit observed in our patient can represent an indication to the use of Etanercept for the management of amyloidosis.

Self-amplified spontaneous emission free-electron laser with an energy-chirped electron beam and undulator tapering

We report the first experimental implementation of a method based on simultaneous use of an energy chirp in the electron beam and a tapered undulator, for the generation of ultrashort pulses in a self-amplified spontaneous emission mode free-electron laser (SASE FEL). The experiment, performed at the SPARC FEL test facility, demonstrates the possibility of compensating the nominally detrimental effect of the chirp by a proper taper of the undulator gaps. An increase of more than 1 order of magnitude in the pulse energy is observed in comparison to the untapered case, accompanied by FEL spectra where the typical SASE spiking is suppressed.

[Comparison of a new medical device with domperidone in functional dyspepsia: a randomized, cross-over, controlled study]

AIM

Management of functional dyspepsia is still controversial. Different controlled trials reported a superiority of prokinetics, H2-receptor antagonists and proton-pump inhibitors over placebo; nevertheless, symptomatic improvement after therapy is often incomplete and some of these drugs possess serious side effects. The aim of the study was to evaluate the efficacy of a new medical device in respect to domperidone in patients with functional dyspepsia.

METHODS

In a cross-over, randomized trial, 36 patients with functional dyspepsia ingested two daily doses of a medical device (Digerfast) or domperidone (Peridon) for 21 days. Clinical evaluation was performed at baseline (T0) and after 21 days (T1) for each treatment. A Visual Analogue Scale (VAS) and the generic scale 36-item Short Form (SF-36) were used to assess symptom intensity and changes in health-related quality of life, respectively.

RESULTS

At T0 no statistical difference was found for each symptom between medical device and domperidone. At T1 both treatments significantly improved in respect to baseline values all the evaluated gastrointestinal symptoms (P<0.5 for all comparisons) except for vomiting. No difference in gastrointestinal symptoms between the two treatments was found at T1. Regarding SF-36 evaluation, at T0 no statistical differences were found for each SF-36 parameter between the two regimens. At T1 both treatments significantly improved most of the evaluated SF-36 parameters in respect to baseline values. No difference in SF-36 parameters between the two treatments was found at T1.

CONCLUSION

Both the medical device and domperidone significantly improved gastrointestinal symptoms and quality of life in subjects with functional dyspepsia, not showing significant difference in efficacy.

Phenotypic changes of the thyrocyte membrane in papillary thyroid carcinoma. A three-dimensional study

Aim of the study was to assess the presence of structural changes in the complex carbohydrate chains of thyroid epithelia undergoing neoplastic transformation. We investigated thyroid cells from neoplastic lesions using a panel of lectins with specific affinity for distinct carbohydrate residues. Sixty samples of thyroid tissue, including normal, hyperplastic and neoplastic lesions were obtained from surgical specimens and blindly evaluated with lectin stains. Confocal microscopy was used to obtain three-dimensional (3-D) images of the samples with a positive reaction. Wheat germ agglutinin (WGA) was consistently positive on the apical membrane of papillary thyroid carcinomas (PTC), was weakly expressed in follicular carcinomas (FC) and resulted negative in normal thyrocytes and in benign conditions. The 3-D microscopy model showed that the WGA staining pattern in light microscopy corresponds to a continuous layer on the luminal surface of both papillary and tubular structures of PTC cells. The other lectins under evaluation did not provide any significant result. In conclusion, in PTC the apical border of thyrocytes showed a strong, specific and consistent staining with WGA. These findings may be related to a modified interaction of thyroglobulin molecule with thyroid cell membrane and with the expression of molecules that are involved in the process of tumorigenesis and tumor progression.

Fabrication, Characterization and Cell Cultures on a Novel Composite Chitosan-Nano-Hydroxyapatite Scaffold

This paper deals with the characterizations made during the development of a nano-HAp loaded chitosan scaffold, obtained by the freeze-drying technique combined with a novel “in situ” crystal growth method. The nano-composites were characterized by a highly porous and interconnected structure. The XRD patterns and calculated domain sizes of the HAp nano-crystals nucleated on the chitosan scaffolds are very similar to the ones recorded for deproteinated bone apatite. Both osteoblasts (MG63) and mesenchimal cells (hMSC) were showing good proliferation and adhesion onto the scaffolds. The presence of extensive filopodia and excellent spreading in and around the interconnected porous structure, indicated a strong cellular adhesion and growth. Moreover a good hMSC osteogenic differentiation has been verified. The observations related to well-developed structure morphology, physicochemical properties and high cytocompatibility suggest that the obtained chitosan–nHA porous scaffolds are potential candidate materials for bone regeneration.