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Injectable poly (methyl methacrylate) (PMMA) bone cements are widely used in orthopaedics to stabilize fractures and for implant fixation. However, bacterial attachment to bone cements leads to significant complications that can create a need for implant revision. Common attempts at reducing bacterial attachment are through the addition of antibiotics or antibacterial nanometals to the bone cements. However, clinical data is inconclusive on the effectiveness of antibiotic-loaded bone cements and a negative osteoblastic response has been reported for certain additive concentrations. There is therefore a need for an additive that can positively affect osteoblastic behaviour while inhibiting bacterial attachment. Silicon nitride (Si3N4) could be such an additive, with initial studies showing promise in achieving antipathogenic properties. The aim of this study was hence to investigate the possibility of creating a bone cement that can support osteoblast growth while reducing bacterial attachment by introducing silicon nitride powders into an injectable PMMA cement. To this end, commercially available bone cements were doped with 5%, 10% and 20% weight/weight (w/w) of Si3N4. Their mechanical properties were examined through compression testing and their radiopacity was evaluated through fluoroscopy imaging. The samples that fulfilled compressive strength requirements had their biological properties tested using Staphylococcus epidermidis bacteria for antibacterial properties and MC3T3-E1 preosteoblasts for the examination of cytotoxicity. Bone cements that were doped with up to 20% w/w Si3N4 were radiopaque (only 13% reduction in optical density compared to radiopaque controls) and retained their compressive strength (85.35 ± 2.1 MPa compared to 83.4 ± 1.9 MPa for the commercial cements), while significantly reducing bacterial attachment by more than 90% compared to commercial cements and achieving a similar level of preosteoblast metabolic activity. This study supports further evaluation of Si3N4 as an additive to injectable bone cements as a way to create mechanically stable, radiopaque, bacteriostatic bone cements that could improve osteointegration.

Abstract Acute appendicitis is associated with a relatively high mortality rate among elderly patients due to the unusual clinical presentation that often leads to misdiagnosis and, in turn, severe complications. This report describes an extremely uncommon clinical manifestation of acute appendicitis in an elderly patient - a subcutaneous abdominal wall abscess initially treated as cellulitis. Despite the initial misdiagnosis, contrast-enhanced computed tomography revealed a circumscribed inflammatory process of the appendix that was in close proximity to the abdominal wall. The patient underwent a surgical drainage of the abscess, received broad-spectrum antibiotics, and was discharged on day 12 following an uneventful course. Diagnosis of acute appendicitis in elderly patients is challenging due to the atypical clinical presentation and co-existing comorbidities that can be misleading. Early application of high-resolution imaging techniques is necessary to identify the cause of acute abdomen in the elderly population.

Primary Gastrointestinal Angiosarcoma (PGAS) constitutes a rare malignant tumor arising from vascular or lymphatic endothelial cells. The aim of this study was to review the available literature on PGAS and to elucidate its biological behavior and optimal therapeutic approach. PubMed and Embase bibliographical databases were systematically searched (last search April 8th, 2020) for studies concerning PGAS. Ninety-eight studies met our inclusion criteria, involving 110 patients (male/female = 1.5) with an age of 62.40 ± 17.84 (mean, SD) years. They were most frequently located at small (44.5%) and large intestine (35.5%), while 12.7% were multifocal. Surgical resection of the tumor was conducted at 84.0% of the cases combined with adjuvant therapy at 12.3%. One-year cumulative survival was 55.18% (95% CI: 34.33%–71.84%) for large intestine, 30.2% (95% CI: 17.1%–44.5%) for small intestine, whereas multifocal PGAS had a 6-months cumulative survival of 23.08% (95% CI: 5.58%–47.46%). Therefore, PGAS is an extremely rare entity with atypical clinical presentation, challenging diagnosis and aggressive behavior. High clinical suspicion is crucial for its prompt management. Further studies and the development of novel therapeutic agents are required in order to improve survival.

Background - Objective: Primary colorectal squamous cell carcinoma is an extremely rare neoplasm with an incidence of 0.1 to 0.25 per 1,000 diagnosed colorectal carcinomas.The objective of this study was to evaluate its biological behavior and highlight the role of a surgical approach for its management. Methods PubMed and Cohrane databases were independently searched (last search: April 10th, 2020) for articles concerning colorectal squamous cell carcinoma in adult population. Results: Seventy-one studies met predefined inclusion criteria and involved 99 patients (54.5% females) with an age of 56.98 ± 12.19 years (mean ± SD). The most frequent site of occurrence was the rectum (63.5%). Open surgery was conducted at 95% of patients, while 21.4% and 30.3% received neoadjuvant and adjuvant therapy respectively.Postoperative complications were developed in 31.3% of patients, while 6.1% died withing the first month following operation. Five-years survival rate was 49.5% (95% CI: 33.7%-63.4%). Female sex (HR: 0.24; 95% CI: 0.11–0.54; p-value: 0.001) and presence of postoperative complications (HR: 4.10; 95%CI: 1.47–1.46; p-value: 0.007) significantly affected the survival. Conclusions Colorectal Squamous Cell Carcinoma is a rare tumor with an aggressive behavior. Surgery is the standard of treatment for the colontumors, while the role of chemoradiotherapy is promising especially for rectal tumors. Further clinical trials are necessary to determine the preferred treatment approach.

Nonalcoholic fatty liver disease (NAFLD) is the most common form of chronic liver disease, affecting almost one-third of the general population and 75% of obese patients with type 2 diabetes. The aim of this article is to review the current evidence concerning the role of quercetin, a natural compound and flavonoid, and its possible therapeutic effects on this modern-day disease. Despite the fact that the exact pathophysiological mechanisms through which quercetin has a hepatoprotective effect on NAFLD are still not fully elucidated, this review clearly demonstrates that this flavonoid has potent antioxidative stress action and inhibitory effects on hepatocyte apoptosis, inflammation, and generation of reactive oxygen species, factors which are linked to the development of the disease. NAFLD is closely associated with increased dietary fat consumption, especially in Western countries. The hepatoprotective effect of quercetin against NAFLD merits serious consideration and further validation by future studies.

Silicon nitride (Si3N4) is a promising biomaterial, currently used in spinal fusion implants. Such implants should result in high vertebral union rates without major complications. However, pseudarthrosis remains an important complication that could lead to a need for implant replacement. Making silicon nitride implants more bioactive could lead to higher fusion rates, and reduce the incidence of pseudarthrosis. In this study, it was hypothesized that creating a highly negatively charged Si3N4 surface would enhance its bioactivity without affecting the antibacterial nature of the material. To this end, samples were thermally, chemically, and thermochemically treated. Apatite formation was examined for a 21-day immersion period as an in-vitro estimate of bioactivity. Staphylococcus aureus bacteria were inoculated on the surface of the samples, and their viability was investigated. It was found that the thermochemically and chemically treated samples exhibited enhanced bioactivity, as demonstrated by the increased spontaneous formation of apatite on their surface. All modified samples showed a reduction in the bacterial population; however, no statistically significant differences were noticed between groups. This study successfully demonstrated a simple method to improve the in vitro bioactivity of Si3N4 implants while maintaining the bacteriostatic properties.