Successful Treatment of Aortic Endocarditis by Achromobacter xylosoxidans with Cefiderocol Combination Therapy in a Non-Hodgkin Lymphoma Patient: Case Report and Literature Review.

Achromobacter xylosoxidans is a Gram-negative aerobic opportunistic bacterium, belonging to the order of Burkholderiales, that can cause infections of virtually all body districts in patients with underlying diseases. However, A. xylosoxidans has rarely been associated with infective endocarditis. The treatment of A. xylosoxidans infections is complicated by both intrinsic and acquired resistance. Here we report on a case of aortic endocarditis by A. xylosoxidans in a Non-Hodgkin lymphoma patient treated with a combination of cefiderocol and other antibiotics, and summarize the available literature.

The 3D-structure, kinetics and dynamics of the E. coli nitroreductase NfsA with NADP+ provide glimpses of its catalytic mechanism.

Nitroreductases activate nitroaromatic antibiotics and cancer prodrugs to cytotoxic hydroxylamines and reduce quinones to quinols. Using steady-state and stopped-flow kinetics, we show that the Escherichia coli nitroreductase NfsA is 20-50 fold more active with NADPH than with NADH and that product release may be rate-limiting. The crystal structure of NfsA with NADP+ shows that a mobile loop forms a phosphate-binding pocket. The nicotinamide ring and nicotinamide ribose are mobile, as confirmed in molecular dynamics (MD) simulations. We present a model of NADPH bound to NfsA. Only one NADP+ is seen bound to the NfsA dimers, and MD simulations show that binding of a second NADP(H) cofactor is unfavourable, suggesting that NfsA and other members of this protein superfamily may have a half-of-sites mechanism.

Efficacy and Safety of Remdesivir over Two Waves of the SARS-CoV-2 Pandemic.

The aim of this study is to describe the features, the outcomes, and the clinical issues related to Remdesivir administration of a cohort of 220 patients (pts) with COVID-19 hospitalized throughout the last two pandemic waves in Italy. One hundred and nine pts were enrolled from 1 September 2020, to 28 February 2021 (Group A) and 111 from 1 March to 30 September 2021 (Group B). Notably, no differences were reported between the two groups neither in the timing of hospitalization. nor in the timing of Remdesivir administration from symptoms onset. Remarkably, a higher proportion of pts with severe COVID-19 was observed in Group B (25% vs. 10%, p < 0.001). At univariate and multivariate analysis, rather than the timing of Remdesivir administration, age, presence of coexisting conditions, D-dimers, and O2 flow at admission correlated positively to progression to non-invasive ventilation, especially for patients in Group B. However, the rate of admission in the Intensive Care Unit and/or death was comparable in the two groups (7% vs. 4%). Negligible variations in serum GOT, GPT, GGT, and eGFR levels were detected. A mean reduction in heart rate was noticed within the first three days of antiviral treatment (p < 0.001). Low rate of ICU admission, high rate of clinical recovery, and good drug safety were observed in COVID-19 patients treated with Remdesivir during two diverse pandemic waves.

The structures of E. coli NfsA bound to the antibiotic nitrofurantoin; to 1,4-benzoquinone and to FMN.

NfsA is a dimeric flavoprotein that catalyses the reduction in nitroaromatics and quinones by NADPH. This reduction is required for the activity of nitrofuran antibiotics. The crystal structure of free Escherichia coli NfsA and several homologues have been determined previously, but there is no structure of the enzyme with ligands. We present here crystal structures of oxidised E. coli NfsA in the presence of several ligands, including the antibiotic nitrofurantoin. Nitrofurantoin binds with the furan ring, rather than the nitro group that is reduced, near the N5 of the FMN. Molecular dynamics simulations show that this orientation is only favourable in the oxidised enzyme, while potentiometry suggests that little semiquinone is formed in the free protein. This suggests that the reduction occurs by direct hydride transfer from FMNH- to nitrofurantoin bound in the reverse orientation to that in the crystal structure. We present a model of nitrofurantoin bound to reduced NfsA in a viable hydride transfer orientation. The substrate 1,4-benzoquinone and the product hydroquinone are positioned close to the FMN N5 in the respective crystal structures with NfsA, suitable for reaction, but are mobile within the active site. The structure with a second FMN, bound as a ligand, shows that a mobile loop in the free protein forms a phosphate-binding pocket. NfsA is specific for NADPH and a similar conformational change, forming a phosphate-binding pocket, is likely to also occur with the natural cofactor.

Cartilage Micrografts as a Novel Non-Invasive and Non-Arthroscopic Autograft Procedure for Knee Chondropathy: Three-Year Follow-Up Study.

(1) Background: Focal chondral defects of the knee can significantly impair patient quality of life. Although different options are available, they are still not conclusive and have several limitations. The aim of this study was to evaluate the role of autologous cartilage micrografts in the treatment of knee chondropathy. (2) Methods: Eight patients affected by knee chondropathy were evaluated before and after 6 months and 3 years following autologous cartilage micrografts by magnetic resonance imaging (MRI) for cartilage measurement and clinical assessment. (3) Results: All patients recovered daily activities, reporting pain reduction without the need for analgesic therapy; Oxford Knee Score (OKS) was 28.4 ± 6 and 40.8 ± 6.2 and visual analogue scale (VAS) was 5.5 ± 1.6 and 1.8 ± 0.7 before and after 6 months following treatment, respectively. Both scores remained stable after 3 years. Lastly, a significant improvement of the cartilage thickness was observed using MRI after 3 years. (4) Conclusions: Autologous cartilage micrografts can promote the formation of new cartilage, and could be a valid approach for the treatment of knee chondropathy.

Progenitor-cell-enriched micrografts as a novel option for the management of androgenetic alopecia.

Regenerative medicine is a multidisciplinary field that combines engineering and life science principles to promote regeneration, potentially restoring the physiological condition in diseased tissues. Specifically, the developments of complex grafts enhance the intrinsic regenerative capacity of the host by altering its environment. Autologous micrografts obtained through Rigenera® micrografting technology are able to promote derma and bone regeneration. Androgenetic alopecia (AGA) leads to a progressive thinning of scalp hair affecting 60-70% of the adult population worldwide. Pharmacological treatment offers moderate results and hair transplantation represents the only permanent treatment option. The aim of this study was to demonstrate the role of dermis micrografting in the treatment of AGA by clinical and histological evaluations after 4, 6, and 12 months. Hair growth and density were improved at all indicated times. Those outcomes were also confirmed by the TrichoScan® analysis, reporting an increase of total hair count and density with an increase and reduction of anagen and telogen phases, respectively. Scalp dermoscopic analysis showed an improvement of hair density and histological analysis indicated a clear amelioration of the scalp, development of hair follicles, and a beginning of cuticle formation. Collectively, those results suggest a possible use of the micrografts as a novel therapeutic option in the management of AGA.

The Role of Autologous Dermal Micrografts in Regenerative Surgery: A Clinical Experimental Study.

The aim of the study was the objective assessment of the effectiveness of a microfragmented dermal extract obtained with Rigenera™ technology in promoting the wound healing process in an in vivo homogeneous experimental human acute surgical wound model. The study included 20 patients with 24 acute postsurgical soft tissue loss and a planned sequential two-stage repair with a dermal substitute and an autologous split-thickness skin graft. Each acute postsurgical soft tissue loss was randomized to be treated either with an Integra® dermal substitute enriched with the autologous dermal micrografts obtained with Rigenera™ technology (group A-Rigenera™ protocol) or with an Integra® dermal substitute only (group B-control). The reepithelialization rate in the wounds was assessed in both groups at 4 weeks through digital photography with the software "ImageJ." The dermal cell suspension enrichment with the Rigenera™ technology was considered effective if the reepithelialized area was higher than 25% of the total wound surface as this threshold was considered far beyond the expected spontaneous reepithelialization rate. In the Rigenera™ protocol group, the statistical analysis failed to demonstrate any significant difference vs. the controls. The old age of the patients likely influenced the outcome as the stem cell regenerative potential is reduced in the elderly. A further explanation for the unsatisfying results of our trial might be the inadequate amount of dermal stem cells used to enrich the dermal substitutes. In our study, we used a 1 : 200 donor/recipient site ratio to minimize donor site morbidity. The gross dimensional disparity between the donor and recipient sites and the low concentration of dermal mesenchymal stromal stem cells might explain the poor epithelial proliferative boost observed in our study. A potential option in the future might be preconditioning of the dermal stem cell harvest with senolytic active principles that would fully enhance their regenerative potential. This trial is registered with trial protocol number NCT03912675.

Autologous Periosteum-Derived Micrografts and PLGA/HA Enhance the Bone Formation in Sinus Lift Augmentation.

Sinus lift augmentation is a procedure required for the placement of a dental implant, whose success can be limited by the quantity or quality of available bone. To this purpose, the first aim of the current study was to evaluate the ability of autologous periosteum-derived micrografts and Poly(lactic-co-glycolic acid) (PLGA) supplemented with hydroxyl apatite (HA) to induce bone augmentation in the sinus lift procedure. Secondly, we compared the micrograft's behavior with respect to biomaterial alone, including Bio-Oss® and PLGA/HA, commercially named Alos. Sinus lift procedure was performed on 24 patients who required dental implants and who, according to the study design and procedure performed, were divided into three groups: group A (Alos + periosteum-derived micrografts); group B (Alos alone); and group C (Bio-Oss® alone). Briefly, in group A, a small piece of periosteum was collected from each patient and mechanically disaggregated by Rigenera® protocol using the Rigeneracons medical device. This protocol allowed for the obtainment of autologous micrografts, which in turn were used to soak the Alos scaffold. At 6 months after the sinus lift procedure and before the installation of dental implants, histological and radiographic evaluations in all three groups were performed. In group A, where sinus lift augmentation was performed using periosteum-derived micrografts and Alos, the bone regeneration was much faster than in the control groups where it was performed with Alos or Bio-Oss® alone (groups B and C, respectively). In addition, the radiographic evaluation in the patients of group A showed a radio-opacity after 4 months, while after 6 months, the prosthetic rehabilitation was improved and was maintained after 2 years post-surgery. In summary, we report on the efficacy of periosteum-derived micrografts and Alos to augment sinus lift in patients requiring dental implants. This efficacy is supported by an increased percentage of vital mineralized tisssue in the group treated with both periosteum-derived micrografts and Alos, with respect to the control group of Alos or Bio-Oss® alone, as confirmed by histological analysis and radiographic evaluations at 6 months from treatment.

Rigenera protocol in the treatment of surgical wound dehiscence.

The effective management of post-operative wounds is important to prevent potential complications such as surgical-site infections and wound dehiscence. The purpose of this study was to treat wound dehiscence in elderly patients who were subjected to orthopaedic surgical interventions. The dehisced wounds were treated with autologous micro-grafts obtained using a promising CE-certified medical device called Rigeneracons. This instrument is a biological disruptor of human tissues able to specifically select progenitor cells that, as already reported in previous studies, maintain high cell viability but mainly have a high regenerative potential, allowing the repair of damaged tissues. Autologous micro-grafts obtained by Rigeneracons are ready to use and can be applied alone or in combination with biological scaffolds directly on the injured area. We observed in our patients a complete remission of dehisced wounds, on average, after 30 days from micro-grafts application and a total wound re-epithelialisation after 1 year from the surgical intervention. In conclusion, although we reported only three patients, autologous micro-grafts can be considered a promising approach for the treatment of dehisced wounds, improving the wound-healing process and in general the patient's quality of life without using other dressings.

In Vitro and In Vivo Differentiation of Progenitor Stem Cells Obtained After Mechanical Digestion of Human Dental Pulp.

Human population is facing a revolutionary change in the demographic structure with an increasing number of elderly people requiring an unmet need to ensure a smooth aging process and dental care is certainly an important aspect that has to be considered. To date, dentistry has been conservative and the need of transferring the scientific models of regenerative dentistry into clinical practice is becoming a necessity. The aim of this study was to characterize the differentiation commitment (in vitro) and the clinical grafting ability (in vivo) of a population of progenitor stem cells obtained after mechanical digestion of dental pulp with an innovative system recently developed. This approach was successfully used in previous studies to obtain a clinical-grade ready to use dental pulp fragments that could be grafted in autologous tissues to obtain bone. We are thus showing that micro grafts resulting from mechanical digestion contain stem cells with a mesenchymal phenotype, able to differentiate toward different cell types and to generate new bone in patients. We are providing data for the establishment of standardized and routinely oral surgery approaches, having outlined the cellular properties of human stem cells obtained from the dental pulp. This method can represent a valid tool for both regenerative medicine and tissue engineering purposes not only applicable to the cranio-maxillofacial region but, likely, to different bone pathologies for a fastening and healing recovering of patients. J. Cell. Physiol. 232: 548-555, 2017. © 2016 Wiley Periodicals, Inc.

A Regenerative Approach with Dermal Micrografts in the Treatment of Chronic Ulcers.

BACKGROUND: The etiology of non-healing ulcers depends on both systemic and local factors. The introduction of advanced dressing, negative wound therapy and compression therapy have undoubtedly improved clinical outcomes. The principal aim of study was to demonstrate the efficacy of dermal micrografts in the treatment of ulcers with different etiologies. The second aim was to investigate in vitro the action of micrografts in the regenerative process. METHODS: The dermal micro-grafts were obtained from mechanical disaggregation of small pieces of skin tissue through a medical device called Rigeneracons. RESULTS: We observed in vivo the ability of dermal autologous micrografts to improve the healing of venous, diabetic, pressure and post-traumatic ulcers after few week of treatment accomplished in general with a better quality of life for the patients. In vitro results showed that these micrografts express mesenchymal stem cells (MSCS) marker such as CD34, CD73, CD90 and CD105, and are able to form a viable and proliferative biocomplex with collagen sponge. Finally, the site of ulcers displayed a different expression of epidermal growth factors, insulin-like growth factors, platelet-derived growth factors and their receptors and tumor necrosis factor-ß with respect to healthy skin samples. CONCLUSION: We reported a good outcome for the treatment of chronic ulcers using dermal autologous micrografts. Finally, we suggest that the positivity to MSCs markers and the ability to interact with a scaffold can play a key role in their regenerative properties.

Tissue Characterization after a New Disaggregation Method for Skin Micro-Grafts Generation.

Several new methods have been developed in the field of biotechnology to obtain autologous cellular suspensions during surgery, in order to provide one step treatments for acute and chronic skin lesions. Moreover, the management of chronic but also acute wounds resulting from trauma, diabetes, infections and other causes, remains challenging. In this study we describe a new method to create autologous micro-grafts from cutaneous tissue of a single patient and their clinical application. Moreover, in vitro biological characterization of cutaneous tissue derived from skin, de-epidermized dermis (Ded) and dermis of multi-organ and/or multi-tissue donors was also performed. All tissues were disaggregated by this new protocol, allowing us to obtain viable micro-grafts. In particular, we reported that this innovative protocol is able to create bio-complexes composed by autologous micro-grafts and collagen sponges ready to be applied on skin lesions. The clinical application of autologous bio-complexes on a leg lesion was also reported, showing an improvement of both re-epitalization process and softness of the lesion. Additionally, our in vitro model showed that cell viability after mechanical disaggregation with this system is maintained over time for up to seven (7) days of culture. We also observed, by flow cytometry analysis, that the pool of cells obtained from disaggregation is composed of several cell types, including mesenchymal stem cells, that exert a key role in the processes of tissue regeneration and repair, for their high regenerative potential. Finally, we demonstrated in vitro that this procedure maintains the sterility of micro-grafts when cultured in Agar dishes. In summary, we conclude that this new regenerative approach can be a promising tool for clinicians to obtain in one step viable, sterile and ready to use micro-grafts that can be applied alone or in combination with most common biological scaffolds.

An innovative regenerative treatment of scars with dermal micrografts.

BACKGROUND: Pathological scars occur following injuries and are often considered esthetically unattractive. Several strategies have been attempted to improve these types of scars using both surgical and nonsurgical methods. The most common treatments include cryotherapy, intralesional corticosteroid injections, 5-fluorouracil, bleomycin, interferon, and verapamil. AIMS: In this study, we aim to investigate the effectiveness of dermal autologous micrografts in the treatment of pathological scars resulting from burns, trauma, or any iatrogenic source. METHODS: We used a new clinical practice called Rigenera Protocol to obtain autologous micrografts which were in turn injectable in the patients. RESULTS: A significant improvement was observed in appearance and texture of the exaggerated scars in all cases following already 4 months of autologous micrograft treatment We have also shown that these micrografts are composed of mesenchymal stem cells and in addition, histological evaluation verified restoration of the structural layers immediately below the epidermis and a horizontal realignment of collagen fibers in the papillary dermis. CONCLUSION: Our results clearly demonstrate the optimal outcomes obtained following treatment with dermal micrografts on exaggerated scars with different etiologies. However, further studies are required to confirm the efficacy of this new technique.

Dermoscopy of verrucous epidermal nevus: large brown circles as a novel feature for diagnosis.

BACKGROUND: The epidermal nevus is a hamartomatous proliferation of the epithelium that can involve keratinocytes, sebaceous glands, the pilosebaceous unit, and eccrine or apocrine glands. It occurs in one in 1000 live births and most commonly presents as the verrucous type. Dermoscopy is a non-invasive technique commonly used to differentiate between melanocytic and non-melanocytic lesions. OBJECTIVES: This study was performed to analyze dermoscopic aspects of verrucous epidermal nevi, which have not previously been described. METHODS: Dermoscopic analyses of eight different verrucous epidermal nevi were conducted. Each lesion was excised, and its diagnosis was histopathologically confirmed. RESULTS: In non-melanocytic lesions, a new dermoscopic feature of large brown circles was observed. This characteristic is useful in the diagnosis of verrucous epidermal nevi. CONCLUSIONS: Large brown circles represent a specific dermoscopic feature for the diagnosis of verrucous epidermal nevus.

Osteogenic Potential of Human Oral-Periosteal Cells (PCs) Isolated From Different Oral Origin: An In Vitro Study.

The periosteum is a specialized connective tissue containing multipotent stem cells capable of bone formation. In this study, we aimed at demonstrating that human oral periosteal cells derived from three different oral sites (upper vestibule, lower vestibule, and hard palate) represent an innovative cell source for maxillo-facial tissue engineering applications in terms of accessibility and self-commitment towards osteogenic lineage. Periosteal cells (PCs) were isolated from patients with different ages (20-30 yy, 40-50 yy, 50-60 yy); we then analyzed the in vitro proliferation capacity and the bone self-commitment of cell clones culturing them without any osteogenic supplement to support their differentiation. We found that oral PCs, independently of their origin and age of patients, are mesenchymal stem cells with stem cell characteristics (clonogenical and proliferative activity) and that, even in absence of any osteogenic induction, they undertake the osteoblast lineage after 45 days of culture. These results suggest that oral periosteal cells could replace mesenchymal cells from bone marrow in oral tissue-engineering applications.

A New Medical Device Rigeneracons Allows to Obtain Viable Micro-Grafts From Mechanical Disaggregation of Human Tissues.

Autologous graft is considered the gold standard of graft materials; however, this approach is still limited due to both small amount of tissue that can be collected and to reduced cell viability of cells that can be obtained. The aim of this preliminary study was to demonstrate the efficacy of an innovative medical device called Rigeneracons® (CE certified Class I) to provide autologous micro-grafts immediately available to be used in the clinical practice. Moreover, Rigeneracons® is an instrument able to create micro-grafts enriched of progenitors cells which maintain their regenerative and differentiation potential. We reported preliminary data about viability cell of samples derived from different kind of human tissues, such as periosteum, cardiac atrial appendage biopsy, and lateral rectus muscle of eyeball and disaggregated by Rigeneracons®. In all cases we observed that micro-grafts obtained by Rigeneracons® displayed high cell viability. Furthermore, by cell characterization of periosteum samples, we also evidenced an high positivity to mesenchymal cell markers, suggesting an optimal regenerative potential.

Sinus lift tissue engineering using autologous pulp micro-grafts: A case report of bone density evaluation.

BACKGROUND: Although autografts are the standard procedure for bone grafting, the use of bone regeneration by means of dental pulp stem cell is an alternative that opens a new era in this field. Rigenera Protocol is a new technique able to provide the surgeon autologous pulp micro-grafts. MATERIALS AND METHODS: At the Department of Oral Surgery, Don Orione Hospital, Bergamo, Italy, one patient underwent sinus lift elevation with pulp stem micro-grafts gentle poured onto collagen sponge. A CT scan control was performed after 4 months and DICOM data were processed with medical imaging software which gives the possibility to use a virtual probe to extract the bone density. Pearson's Chi-square test was used to investigate difference in bone density (BD) between native and newly formed bone. RESULTS: BD in newly formed bone is about the double of native bone. CONCLUSION: This report demonstrated that micro-grafts derived from dental pulp poured onto collagen sponge are a useful method for bone regeneration in atrophic maxilla.

Traumatic brain injury: oxidative stress and neuroprotection.

SIGNIFICANCE: A vast amount of circumstantial evidence implicates high energy oxidants and oxidative stress as mediators of secondary damage associated with traumatic brain injury. The excessive production of reactive oxygen species due to excitotoxicity and exhaustion of the endogenous antioxidant system induces peroxidation of cellular and vascular structures, protein oxidation, cleavage of DNA, and inhibition of the mitochondrial electron transport chain. RECENT ADVANCES: Different integrated responses exist in the brain to detect oxidative stress, which is controlled by several genes termed vitagens. Vitagens encode for cytoprotective heat shock proteins, and thioredoxin and sirtuins. CRITICAL ISSUES AND FUTURE DIRECTIONS: This article discusses selected aspects of secondary brain injury after trauma and outlines key mechanisms associated with toxicity, oxidative stress, inflammation, and necrosis. Finally, this review discusses the role of different oxidants and presents potential clinically relevant molecular targets that could be harnessed to treat secondary injury associated with brain trauma.