Micrococcal Nuclease stimulates Staphylococcus aureus Biofilm Formation in a Murine Implant Infection Model

Advancements in contemporary medicine have led to an increasing life expectancy which has broadened the application of biomaterial implants. As each implant procedure has an innate risk of infection, the number of biomaterial-associated infections keeps rising. Staphylococcus aureus causes 34% of such infections and is known as a potent biofilm producer. By secreting micrococcal nuclease S. aureus is able to escape neutrophil extracellular traps by cleaving their DNA-backbone. Also, micrococcal nuclease potentially limits biofilm growth and adhesion by cleaving extracellular DNA, an important constituent of biofilms. This study aimed to evaluate the impact of micrococcal nuclease on infection persistence and biofilm formation in a murine biomaterial-associated infection-model with polyvinylidene-fluoride mesh implants inoculated with bioluminescent S. aureus or its isogenic micrococcal nuclease deficient mutant. Supported by results based on in-vivo bioluminescence imaging, ex-vivo colony forming unit counts, and histological analysis it was found that production of micrococcal nuclease enables S. aureus bacteria to evade the immune response around an implant resulting in a persistent infection. As a novel finding, histological analysis provided clear indications that the production of micrococcal nuclease stimulates S. aureus to form biofilms, the presence of which extended neutrophil extracellular trap formation up to 13 days after mesh implantation. Since micrococcal nuclease production appeared vital for the persistence of S. aureus biomaterial-associated infection, targeting its production could be a novel strategy in preventing biomaterial-associated infection.

Productive Performance and Cecum Microbiota Analysis of Broiler Chickens Supplemented with β-Mannanases and Bacteriophages—A Pilot Study

This study was conducted to evaluate the productive performance, intestinal health, and description of the cecum microbiota in broilers supplemented with β-mannanases (MNs) and bacteriophages (BPs). Six hundred one-day-old broilers were divided into four groups and fed one of the following diets: CON—corn–soybean meal + 10 ppm enramycin (ENR); MN: CON + 500 ppm MN; BP: CON + 500 ppm BP; MN + BP: BP + 500 ppm MN. The BP and MN factors showed similar performances to ENR. MN improved the concentration of IgA in the jejunum at 35 days of age. The morphometric index (IM) of the thymus increased by adding MN, while BP increased the liver and thymus IM. The histological analysis showed that BP and MN improved the intestinal morphology. MN + BP showed a tendency to decrease the abundance of Proteobacteria and increase the abundance of Bacteroidetes, indicating better microbiota function. In conclusion, our results demonstrate that the combination of MN + BP has potential in poultry nutrition; however, we highly recommend further experiments to confirm this hypothesis.

Atypical Peripheral Ossifying Fibroma of the Mandible

Peripheral ossifying fibroma (POF) is a benign localized lesion originating from gingival and alveolar oral mucosa. Its origin can be cells of periodontal ligament. The lesions usually develop in women in their twenties. POF is a complex clinical and histological diagnosis due to its shared characteristics with many other conditions. In this paper, we presented a case of an atypical peripheral ossifying fibroma (POF) in the left lateral part of the mandible in a 70-year-old male patient who had two semicircular bridges supported on four implants in the upper and lower jaws. A review of CBCT and orthopedic imaging showed no visible intraosseous changes. Histological analysis revealed the diagnosis of POF. The case in question is interesting, as elaborated on in the discussion section of this paper because POF is usually found in female patients aged between 20 and 30 years.

Optimization of Complete Rat Heart Decellularization Using Artificial Neural Networks

Whole organ decellularization techniques have facilitated the fabrication of extracellular matrices (ECMs) for engineering new organs. Unfortunately, there is no objective gold standard evaluation of the scaffold without applying a destructive method such as histological analysis or DNA removal quantification of the dry tissue. Our proposal is a software application using deep convolutional neural networks (DCNN) to distinguish between different stages of decellularization, determining the exact moment of completion. Hearts from male Sprague Dawley rats (n = 10) were decellularized using 1% sodium dodecyl sulfate (SDS) in a modified Langendorff device in the presence of an alternating rectangular electric field. Spectrophotometric measurements of deoxyribonucleic acid (DNA) and total proteins concentration from the decellularization solution were taken every 30 min. A monitoring system supervised the sessions, collecting a large number of photos saved in corresponding folders. This system aimed to prove a strong correlation between the data gathered by spectrophotometry and the state of the heart that could be visualized with an OpenCV-based spectrometer. A decellularization completion metric was built using a DCNN based classifier model trained using an image set comprising thousands of photos. Optimizing the decellularization process using a machine learning approach launches exponential progress in tissue bioengineering research.

Histological analysis of thrombi retrieved after acute ischemic stroke from large vessel occlusion: from research to clinical practice

Emergent reperfusion therapies have improved acute ischemic stroke prognosis, but many patients are still bound to bad clinical outcome, probably because of our incomplete knowledge of its pathophysiology. Thanks to mechanical thrombectomy, occluding material is available for histological analysis. Several studies investigated the possible relationship between thrombus composition and clinical, procedural, and radiological variables of acute ischemic stroke. The potential value of thrombus analysis as a tool for clinical practice and research is still not defined, as data from the literature are heterogeneous and sometimes conflicting. We propose a review of the existing literature regarding histological analysis of thrombi in acute ischemic stroke. We classified articles on clot composition according to the clinical variable explored in each study. We first distinguished articles about etiology, procedural, and radiological variables, and then we performed a subclassification for each group. This review could help both in the interpretation of thrombus analysis in clinical practice and in its usage for future research.

The Wound-Healing Effect of Mango Peel Extract on Incision Wounds in a Murine Model

Mangifera indica can generate up to 60% of polluting by-products, including peels. However, it has been shown that flavonoids and mangiferin are mainly responsible for the antioxidant, anti-inflammatory, and antibacterial activities closely related to the wound-healing process. The chemical composition of MEMI (methanolic extract of M. indica) was analyzed by HPLC-DAD, as well as concentrations of total phenol (TPC) and flavonoids (TFC) and antioxidant activity (SA50). Wound-healing efficacy was determined by measurements of wound contraction, histological analysis, and tensiometric method; moreover, anti-inflammatory, antibacterial, and acute dermal toxicity (OECD 402) were also evaluated. Phenol, resorcinol, conjugated resorcinol, and mangiferin were detected. TPC, TFC, and SA50 were 136 mg GAE/g, 101.66 mg QE/g, and 36.33 µg/mL, respectively. Tensile strength and wound contraction closure did not show significant differences between MEMI and dexpanthenol groups. Histological analysis (after 14 days) shows a similar architecture between MEMI treatment and normal skin. MEMI exhibits a reduction in edema. Staphylococcus epidermidis had an MIC of 2 mg/mL, while Staphylococcus aureus, Pseudomonas aeruginosa, and Escherichia coli reached 4 mg/mL. The MEMI showed no signs of toxicity. Therefore, this study demonstrates multiple targets that flavonoids and mangiferin of MEMI may present during the healing process.

TOPICAL MITOMYCIN C IN THE TREATMENT OF CONJUNCTIVAL SQUAMOUS CELL CARCINOMA ABOUT TWO CASES

These are two male patients, aged 56 and 75, respectively, who presented with an unilateral limbal-conjunctival tumor, after a corneoconjunctival excision of the tumor, the histological analysis was performed and established the diagnosis of conjunctival squamous cell carcinoma Purpose: To describe those two cases of conjunctival squamous cell carcinoma that was successfully treated with adjunctive topical Mitomycin C.

Tissue Stromal Vascular Fraction Improves Early Scar Healing: A Prospective Randomized Multicenter Clinical Trial

Background Wound healing and scar formation depends on a plethora of factors. Given the impact of abnormal scar formation, interventions aimed to improve scar formation would be most advantageous. Tissue stromal vascular fraction (tSVF) of adipose tissue is composed of a heterogenous mixture of cells embedded in extracellular matrix. It contains growth factors and cytokines involved in wound healing processes, eg, parenchymal proliferation, inflammation, angiogenesis, and matrix remodeling. Objectives In this study, we hypothesized that tSVF reduces post-surgical scar formation. Methods This prospective, double-blind, placebo-controlled, randomized trial was conducted between 2016 and 2020. Forty mammoplasty patients were enrolled and followed for 1 year. At the end of the mammoplasty procedure, all patients received tSVF in the lateral 5 cm of the horizontal scar of one breast and a placebo injection in the contralateral breast to serve as an intra-patient control. Primary outcome was scar quality using the patient and observer scar assessment scale (POSAS). Secondary outcomes were obtained with photograph evaluation and histological analysis of scar tissue samples. Results Thirty-four of 40 patients completed follow-up. Six months postoperatively, injection of tSVF had significantly improved postoperative scar appearance as assessed by POSAS questionnaire (observer and patient questionnaire). No difference was observed at 12 months postoperatively. No improvement was seen based on the evaluation of photographs and histological analysis of postoperative scars between both groups. Conclusions Injection of tSVF resulted in improved wound healing and reduced scar formation at 6 months postoperative, without any noticeable advantageous effects seen at 12 months.