Human osteoblast-like cell adhesion on titanium substrates covalently functionalized with synthetic peptides

Biomaterials to be used for the production of endosseous devices in dental, orthopedic and maxillo-facial applications, might be designed to support, guide and enhance osteoblast adhesion. Cell recruitment onto biomaterial surface is a fundamental step within the complex process responsible for implant osseointegration; this process involves several proteins from the extra cellular matrix (ECM), cytoskeleton and cell membrane. A new strategy to improve endosseous implant integration is based on preparing biomimetic surfaces able to present adhesive factors to cells. Osteoblast adhesion takes place by at least two different mechanisms: the most investigated one implies the interaction with RGD sequences via cell-membrane integrin receptors; a further mechanism concerns the interaction between cell-membrane heparan sulfate proteoglycans and heparin-binding sites of ECM proteins. In the present study two different biomimetic surfaces were obtained by covalently grafting two adhesive peptides on oxidized titanium substrates after silanization: an RGD-containing peptide and a peptide mapped on human vitronectin. The two sequences are known to act via different adhesive mechanisms. The amount of human osteoblasts adhered onto peptide-enriched or not enriched titanium oxidized surfaces and the strength of cell binding were estimated, thus comparing the capacity of the bioactive substrates in promoting cell adhesion.     

HBV and HCV infection among non-European Union immigrants in North-East Italy.

The status of hepatitis B virus (HBV) and hepatitis C virus (HCV) infection among non-European Union (non-EU) immigrants in North-East Italy was evaluated. Among the 1683 individuals tested the prevalence of HBsAg was 8.9% (150 subjects) and of HBV antibodies (anti-HBc with/without anti-HBs) was 38.9% (654 subjects). The distribution of HBV serological markers showed significant differences according to region of origin; the highest prevalence of infection (76.9%) and carriage (16.1%) was found in immigrants from sub-Saharan Africa. Among the 933 individuals screened for HCV infection, prevalence of antibody was much lower (0.9%) than that observed in the Italian general population (3.2-12.6%). The large number of HBV carriers among immigrants could increase the number of new adult infections due to life-style habits or professional risks in the host population. In contrast, the risk of HCV spread from non-EU immigrants is very low.     

Spinal malignant melanotic schwannoma. Case report.

The authors report a rare case of spinal cord compression syndrome due to a malignant melanotic schwannoma. Pathogenesis, diagnostic difficulty and therapeutical problems are discussed. The authors conclude that such tumours should be surgically treated due to the possibility of a benign clinical behaviour even in those cases showing malignant histological features.     

Teaching gastroenterology using the problem-based learning method.

The need to change the methods of teaching medical students has become self-evident in the past two decades, and strategies for revision are indicated in the new course curriculum, Tabella XVIII. A modern teaching method is the problem-based learning (PBL) method, which has already been adopted by over 100 medical schools throughout the world. This method can also be a satisfactory tool for teaching gastroenterology to undergraduate students, and its implementation requires only a few resources that are available in most universities. The theoretical principles of the method are illustrated and practical suggestions are given to set up a course in gastroenterology using this method.     

Low prevalence of anti-HCV antibody among Italian children

Summary The seroprevalence of anti-HCV antibody was studied among 2,749 children and teenagers (1,438 males and 1,311 females) living in Italy. Anti-HCV antibody testing was positive by both EIA and RIBA in ten (0.36%) subjects. The positivity rate increased with age, ranging from 0 among children less than 6 years of age to 0.8% among those aged 17–19 years x² linear regression=0.038). Anti-HCV prevalence ranged from 0.2% in northeastern regions and in Apulia to 0.6% in Sicily and Sardinia (p>0.005), and no difference was seen between males (0.35%, C.I. 95%: 0.04–0.66) and females (0.38%, C.I. 95%:0.04–0.66) (Fisher's exact test=0.565). From these data it appears that in Italy HCV infection is an uncommon event during childhood.

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Niedrige Prävalenz von Anti-HCV-Antikörpern bei italienischen Kindern

Zusammenfassung Bei 2.749 Kindern und Jugendlichen (1.438 Jungen und 1.311 Mädchen), die in Italien leben, wurde eine Studie zur Seroprävalenz der anti-HCV Antikörper durchgeführt. Bei zehn der Getesteten (0,36%) fand sich mit EIA und RIBA ein positiver Befund. Die Rate an positiven Fällen nahm mit dem Alter zu von 0 bei Kindern unter 6 Jahren auf 0,8% bei den 17–19jährigen (Chi² lineare Regression=0,038). In den nordöstlichen Regionen and Apulien lag die anti-HCV Seroprävalenz bei 0,2%, in Sizilien und Sardinien bei 0,6% (p>0,005). Zwischen Mädchen und Jungen fand sich kein Unterschied (0,35%, 95% CI: 0,04–0,66 bei Jungen und 0,38%, 95% CI: 0,04–0,66; Fisher's exakter Test 0,565). Aus diesen Daten läßt sich ableiten, daß die HCV-Infektion in der Kindheit in Italien ein seltenes Ereignis ist.

     

C-Reactive Protein 2 Days After Laparoscopic Gastric Bypass Surgery Reliably Indicates Leaks and Moderately Predicts Morbidity

Background

The aim of the present study was to evaluate whether serum C-reactive protein (CRP) is a useful predictor of early post-operative complications, particularly of intestinal leaks after laparoscopic Roux-en-Y gastric bypass (LRYGB) surgery.

Methods

The present study was a retrospective analysis of a prospectively maintained database with 809 patients who underwent LRYGB from 2002 until 2011. For 410 of these patients, at least one CRP measurement within the first seven post-operative days was available. The diagnostic value was determined by the area under the curve (AUC) of the receiver operating characteristic (ROC) curve.

Results

Forty-nine of 410 patients (12.0?%; 95?% confidence intervals [95?% CI], 9.2?C15.5?%) developed surgery-related complications. Leaks occurred in 17 patients (4.1?%; 95?% CI, 2.6?C6.5?%) at a median of 5?days after surgery. CRP levels 2?days after surgery showed the highest diagnostic value for post-operative complications (AUC, 0.74; 95?% CI, 0.60?C0.89). Sensitivity was 0.53 (95?% CI, 0.31?C0.74) and specificity was 0.91 (95?% CI, 0.79?C0.96) on day 2 (cutoff level, 229?mg/l). The sensitivity for intestinal leaks was 1.00 (95?% CI, 0.51?C1.00).

Conclusion

CRP on post-operative day 2 is a valuable predictor of post-operative complications, in particular intestinal leaks. Radiological imaging studies for intestinal leaks could be restricted to patients with CRP values exceeding 229?mg/l.     

Intraoperative ultrasound in spinal tumor surgery

Purpose

Intraoperative ultrasound (ioUS) has become increasingly widespread in brain tumor surgery but it is not yet a standard procedure in spinal surgery. We analyzed intraoperative ultrasonographic findings of different spinal tumors and their influence on the surgical strategy.

Methods

We evaluated patients who underwent surgery for spinal tumor (extradural, intradural extramedullary, intradural intramedullary) removal, with ultrasound (US) guidance. Intraoperative standard B-mode images were acquired using a 3–11 MHz linear US probe. Before tumor removal the lesion was identified on the two axes and measured and defined as hyperechoic, isoechoic or hypoechoic. Other characteristics of the lesions were considered: the presence of calcifications, cystic/necrotic areas, diffuse or circumscribed appearance, and the relationships with the surrounding anatomical structures.

Results

In all 34 cases it was possible to visualize the lesion, as well as the surrounding neural structures (like dura mater, dentate ligament, arachnoid membranes) and vascular structures. In 9 out of 34 cases, ioUS showed that the surgical approach was not wide enough: therefore it was necessary to enlarge the bony approach before dural opening. In 8 intramedullary cases, ioUS was used to correctly tailor the myelotomy.

Conclusions

We present our ioUS series findings along with some pictorial essays of different spinal tumors treated at our institution. IoUS is a valuable tool to detect spinal lesions, evaluate the surgical approach and plan the surgical strategy considering the position and relationships of the lesion with bony, neural and vascular structures.     

Fusion imaging for intra-operative ultrasound-based navigation in neurosurgery

The major shortcoming of image-guided navigation systems is the use of presurgically acquired image data, which does not account for intra-operative changes such as brain shift, tissue deformation and tissue removal occurring during the surgical procedure. Intra-operative ultrasound (iUS) is becoming widely used in neurosurgery but they lack orientation and panoramic view. In this article, we describe our procedure for US-based real-time neuro-navigation during surgery. We used fusion imaging between preoperative magnetic resonance imaging (MRI) and iUS for brain lesion removal in 67 patients so far. Surgical planning is based on preoperative MRI only. iUS images obtained during surgery are fused with the preoperative MRI. Surgery is performed under intra-operative US control. Relying on US imaging, it is possible to recalibrate navigated MRI imaging, adjusting distortion due to brain shift and tissue resection, continuously updating the two modalities. Ultrasound imaging provides excellent visualization of targets, their margins and surrounding structures. The use of navigated MRI is helpful in better understanding cerebral ultrasound images, providing orientation and panoramic view. Intraoperative US-guided neuro-navigation adjustments are very accurate and helpful in the event of brain shift. The use of this integrated system allows for a true real-time feedback during surgery.