Effects of processing on structural, mechanical and biological properties of collagen-based substrates for regenerative medicine.

The aim of this work was to investigate the structural features of type I collagen isoforms and collagen-based films at atomic and molecular scales, in order to evaluate whether and to what extent different protocols of slurry synthesis may change the protein structure and the final properties of the developed scaffolds. Wide Angle X-ray Scattering data on raw materials demonstrated the preferential orientation of collagen molecules in equine tendon-derived collagens, while randomly oriented molecules were found in bovine skin collagens, together with a lower crystalline degree, analyzed by the assessment of FWHM (Full Width at Half Maximum), and a certain degree of salt contamination. WAXS and FT-IR (Fourier Transform Infrared) analyses on bovine collagen-based films, showed that mechanical homogenization of slurry in acidic solution was the treatment ensuring a high content of super-organization of collagen into triple helices and a high crystalline domain into the material. In vitro tests on rat Schwannoma cells showed that Schwann cell differentiation into myelinating cells was dependent on the specific collagen film being used, and was found to be stimulated in case of homogenization-treated samples. Finally DHT/EDC crosslinking treatment was shown to affect mechanical stiffness of films depending on collagen source and processing conditions.

[Topical pharmacologic approach with 5% lidocaine medicated plaster in the treatment of localized neuropathic pain]. / Approccio farmacologico topico con lidocaina cerotto 5% nel trattamento del dolore neuropatico localizzato.

The treatment of neuropathic pain is a medical challenge. The responsiveness to the different classes of drugs is often unsatisfactory and frequently associated to a wide range of side effects. International guidelines suggest for the "localized" neuropathic pain the topical treatment with 5% lidocaine medicated plaster, alone or associated to systemic drugs, as the first choice since its favorable efficacy and tolerability profile. Many clinical experiences support the rationale for using 5% lidocaine medicated plaster in different kinds of localized neuropathic pain, such as postherpetic and trigeminal neuralgia, compressive syndromes, painful diabetic polyneuropathy and pain secondary to trauma or surgical interventions. This paper reports a series of clinical cases whose heterogeneity suggests the wide burden of applicability of the topical 5% lidocaine, either alone and associated to systemic drugs. All the described conditions were characterized by a highly intense pain, not adequately controlled by actual medications, which improved after the use of topical lidocaine. The good response to lidocaine allowed the reduction, of even the withdrawal, of concurrent drugs and improved the patients' quality of life.

[A rationale basis for airways conditioning: too wet or not too wet? ]. / Una base razionale per il condizionamento delle vie aeree: umidificare troppo o non troppo?

Medical gases conditioning during mechanical invasive ventilation is nowadays a problem. In fact, in spite of conditioning guidelines, absolute humidity (AH) into 25-35 mg/l, clinical evaluation of the optimal level of airway humidification has not yet been established with certainty. Physiologically, during spontaneous respiration the airway hydric balance, inspiratory AH expiratory AH, is negative of 27 mg/l about. Usually the patients on mechanical ventilation have an expiratory AH of 32-33 mg/l. An overhumidification of inspired gases, positive airway hydric balance, gives anatomic-physiological alterations of airways and lung parenchyma. During invasive mechanical ventilation, the practice of active hot humidifiers has a positive or level airway hydric balance. We think that inspired AH must be equal to expired AH to maintain an airway hydric balance at least level. At last, the temperature of inspired gases, with active hot humidifiers, shouldn't exceed 32-34 degrees C.

Increased prevalence of Helicobacter pylori in patients with diabetes mellitus.

BACKGROUND: Whilst upper gastrointestinal disturbances are frequently observed in patients with diabetes mellitus, little is known about the prevalence of Helicobacter pylori infection and peptic disease in these patients. AIM: To evaluate prevalence of Helicobacter pylori infection and peptic disease lesions in diabetics with dyspeptic symptoms. PATIENTS AND METHODS: Study population comprises 74 consecutive diabetes mellitus patients with dyspepsia and 117 consecutive non diabetic dyspeptic patients. Upon enrolment, each patient completed an interview screening questionnaire to obtain information concerning presence and severity of dyspepsia. All patients underwent upper gastrointestinal endoscopy with biopsy specimens being collected from gastric antrum and body Helicobacter pylori was evaluated in each patient by rapid urease test and histology (Giemsa). Gastritis was classified according to the Sydney System. Statistical analysis was performed by chi-square, Fisher exact or t test and logistic regression analysis. A p value <0.05 was considered significant. RESULTS: Prevalence of Helicobacter pylori infection was found to be significantly higher in diabetics than in controls. The prevalence rate of endoscopic lesions was comparable in the two groups, but the association between endoscopic lesions and Helicobacter pylori infection was significantly higher in diabetics. Overall, the presence of chronic gastritis, both non atrophic and atrophic, as well as intestinal metaplasia were comparable in the two groups of patients, whilst the association between chronic gastritis and Helicobacter pylori infection or gastritis activity were significantly higher in diabetics. In neither group, was any correlation found between severity of dyspepsia and presence of endoscopic lesions, chronic gastritis or Helicobacter pylori infection. CONCLUSIONS: These data show a higher prevalence of Helicobacter pylori infection in diabetes mellitus patients with dyspepsia. Helicobacter pylori infection was significantly associated both with the presence of endoscopic lesions and chronic gastritis in diabetic patients, but not in the controls.