adipose tissue derived stem cell therapy for post surgical breast reconstruction more light than shadows

Breast cancer remains the most common tumor in women, and new techniques for post- surgical breast reconstruction have been recently introduced. These new procedures include autologous fat grafting with or without the enrichment with autologous stromal vascular fraction (SVF), platelet-derived growth factors and insulin. The reported improvement of fat graft viability with these techniques likely depends on the presence in the SVF of multipotent resident adipose derived-stem cells (ASCs). The clinical advantage derives from the plasticity of ASCs and their ability to generate new functional adipose tissue and vessels. However, there is an ongoing debate regarding the possible interplay between breast tumor cells and resident or transplanted ASCs for their capacity to locally secrete growth factors. Most of the data in the literature concerning ASCs is derived from in vitro models, whereas the knowledge of ASC behavior in vivo remains scarce. Recent reports concerning SVF/ASC enrichment of fat graft did not describe any significant worsening of prognosis for patients undergoing those procedures. However, further studies and longer follow-ups are needed to specifically define technical procedures and to confirm the safety of procedures of SVF/ASC enrichment during post-surgical breast reconstruction

Ageing and microvasculature

A decline in the function of the microvasculature occurs with ageing. An impairment of endothelial properties represents a main aspect of age-related microvascular alterations. Endothelial dysfunction manifests itself through a reduced angiogenic capacity, an aberrant expression of adhesion molecules and an impaired vasodilatory function. Increased expression of adhesion molecules amplifies the interaction with circulating factors and inflammatory cells. The latter occurs in both conduit arteries and resistance arterioles. Age-related impaired function also associates with phenotypic alterations of microvascular cells, such as endothelial cells, smooth muscle cells and pericytes. Age-related morphological changes are in most of cases organ-specific and include microvascular wall thickening and collagen deposition that affect the basement membrane, with the consequent perivascular fibrosis. Data from experimental models indicate that decreased nitric oxide (NO) bioavailability, caused by impaired eNOS activity and NO inactivation, is one of the causes responsible for age-related microvascular endothelial dysfunction. Consequently, vasodilatory responses decline with age in coronary, skeletal, cerebral and vascular beds. Several therapeutic attempts have been suggested to improve microvascular function in age-related end-organ failure, and include the classic anti-atherosclerotic and anti-ischemic treatments, and also new innovative strategies. Change of life style, antioxidant regimens and anti-inflammatory treatments gave the most promising results. Research efforts should persist to fully elucidate the biomolecular basis of age-related microvascular dysfunction in order to better support new therapeutic strategies aimed to improve quality of life and to reduce morbidity and mortality among the elderly patients

Evaluation of LIAISON® C. difficile glutamate dehydrogenase and LIAISON® C. difficile toxin A and B in Copan FecalSwabTM samples in a three-step algorithm for the diagnosis of Clostridium difficile infection

The presumptive laboratory diagnosis of Clostridium difficile infection is achieved by the means of the detection of a common antigen (glutamate dehydrogenase, GDH) in stool, then confirming the positives either by the detection of toxins A and B or by a molecular test for the detection of pathogenicity locus, encoding for the two toxins and for the binary toxin. A fully automated chemiluminescence system for the GDH antigen (LIAISON® C. difficile GDH) and for the detection of toxins A and B (LIAISON® C. difficile Toxin A and B) (DiaSorin, Gerenzano, Italy) allows for the performance of these tests on large numbers of samples in a short time, ensuring the traceability of the data

CD146 expression regulates osteochondrogenic differentiation of human adipose-derived stem cells

Tissue engineering aims to develop innovative approaches to repair tissue defects. The use of adipose-derived stem cells (ASCs) in tissue regeneration was extensively investigated for osteochondrogenesis. Among the ASC population, ASCs expressing the CD146 were demonstrated to be multipotent and considered as perivascular stem cells, although the functional role of CD146 expression in these cells remains unclear. Herein, we investigated the influence of CD146 expression on osteochondrogenic differentiation of ASCs. Our results showed that, in two-dimensional culture systems, sorted CD146(+) ASCs proliferated less and displayed higher adipogenic and chondrogenic potential than CD146(-) ASCs. The latter demonstrated a higher osteogenic capacity. Besides this, CD146(+) ASCs in three-dimensional Matrigel/endothelial growth medium (EGM) cultures showed the highest angiogenic capability. When cultured in three-dimensional collagen scaffolds, CD146(+) ASCs showed a spontaneous chondrogenic differentiation, further enhanced by the EGM medium's addition. Finally, CD146(-) ASCs seeded on hexafluoroisopropanol silk scaffolds displayed a greater spontaneous osteogenetic capacity. Altogether, these findings demonstrated a functional and relevant influence of CD146 expression in ASC properties and osteochondrogenic commitment. Exploiting the combination of specific differentiation properties of ASC subpopulations and appropriate culture systems could represent a promising strategy to improve the efficacy of new regenerative therapies

Adipose-derived stem cell-mediated paclitaxel delivery inhibits breast cancer growth.

Breast cancer represents the main malignancy in women and autologous fat grafting is a diffuse procedure in the management of post-surgical breast defects causing patients' psychosocial problems, with high costs for the public health. Recently, beneficial effects of fat grafting during post-surgical breast reconstruction have been amplified from the enrichment with human adipose-derived stem cells (ASCs) present in the stromal vascular fraction (SVF) of adult adipose tissue isolated during intraoperatory procedures. The major concern about the ASC enrichment during post-surgery breast reconstruction depends on their potential ability to release growth factors and hormones that can promote proliferation of residual or quiescent cancer cells, with the risk of de novo cancer development or recurrence. The recent description that adult stem cells primed in vitro may be vehicle for anti-cancer drug delivery offers a new vision concerning the role of ASCs in breast reconstruction after cancer surgery. Paclitaxel (PTX) is a chemotherapeutic agent acting as a microtubule-stabilizing drug inhibiting cancer cell mitotic activity. We optimized PTX loading and release in cultured ASCs and then analyzed the effects of PTX-loaded ASCs and their conditioned medium on CG5 breast cancer survival, proliferation and apoptosis in vitro, and inCG5 xenograft in vivo. We documented that ASCs can uptake and release PTX in vitro, with slight cytotoxic effects. Interestingly, PTX-loaded ASCs in co-culture, as well as conditioned medium alone, inhibited CG5 cell proliferation and survival in vitro and xenograft tumor growth in vivo. The antitumor effect of PTX-loaded ASCs may offer a new perspective concerning the use of ASCs during breast reconstruction becoming an additional local preventive chemotherapeutic agent against tumor recurrence. However, further experiments in vitro and in vivo are needed to collect more evidence confirming the efficacy and safety in cancer patients

A novel KPC-166 in ceftazidime/avibactam resistant ST307 Klebsiella pneumoniae causing an outbreak in intensive care COVID Unit, Italy

Introduction: Aim of the study was the molecular characterization of 21 ceftazidime/avibactam resistant (CZA-R) Klebsiella pneumoniae strains, collected in the period October 2021–March 2022 from an Intensive Care COVID Unit in a Northern Italian Hospital. Methods: After growth on selective/chromogenic culture media and susceptibility tests assessment, resistance genes content was ascertained for all the isolates by the HybriSpot 12 multiplexing, PCR and Whole-Genome Sequencing (WGS). Clonality was assessed by PFGE and MLST according to the Pasteur scheme. A SNPs-based phylogenetic tree was obtained comparing representative isolates and global genomes. The blaKPC gene horizontal transmission was evaluated by conjugation experiments. blaKPC-166 was cloned in a pCR2.1 vector and transformed in chemically competent TOP10 cells. Results: Sixteen inpatients resulted positive for colonization and/or infection by KPC-producing K. pneumoniae (KPC-Kp) strains. The 21 CZA-R KPC-Kp isolates obtained showed MDR phenotype; susceptibility to meropenem was always retained. All the CZA-R KPC-Kp presented a novel blaKPC variant, named blaKPC-166, showing a single nucleotide substitution (T811C) compared to the blaKPC-94; but related to blaKPC-2. Two different pulsotypes were detected: A in 18/21 and B in 1/21 cases, two strains from the same patient being untypable by PFGE. Interestingly, the outbreak was sustained by the high-risk clone ST307, although the ST22, ST6342, ST6418 and ST6811 have also been identified and associated to KPC-166. Worryingly, blaKPC-166 could be transferred horizontally and, after cloning, it conferred resistance to CZA. Discussion: This novel variant confers CZA–resistance and carbapenems susceptibility restoration. As KPC-166 was found expressed by multiple Kp clones, greater efforts should be made to prevent the further dissemination of such strains in Italian clinical settings