R-loop landscapes in the developing human brain are linked to neural differentiation and cell-type specific transcription.

Here, we construct genome-scale maps for R-loops, three-stranded nucleic acid structures comprised of a DNA/RNA hybrid and a displaced single strand of DNA, in the proliferative and differentiated zones of the human prenatal brain. We show that R-loops are abundant in the progenitor-rich germinal matrix, with preferential formation at promoters slated for upregulated expression at later stages of differentiation, including numerous neurodevelopmental risk genes. RNase H1-mediated contraction of the genomic R-loop space in neural progenitors shifted differentiation toward the neuronal lineage and was associated with transcriptomic alterations and defective functional and structural neuronal connectivity in vivo and in vitro. Therefore, R-loops are important for fine-tuning differentiation-sensitive gene expression programs of neural progenitor cells.

A Case Report on Treatment of Nonhealing Leg Ulcer: Do Not Forget the Underlying Disease.

Prevalence of nonhealing ulcers of lower extremities has increased over years causing heavy health, social, and economic burdens. Chronic ulcers are difficult to treat since they require tailored multistep treatment and patient compliance. To treat chronic wounds successfully, clinicians must keep in mind the ulcer etiology as well as the underlying diseases. Several factors may be involved in the pathogenesis of chronic skin ulcers. Leukocytoclastic vasculitis belongs to the group of immune vascular diseases and may be an extrahepatic manifestation of hepatitis C virus (HCV) infection. We describe the case of a patient with a nonhealing vasculitic leg ulcer and chronic HCV infection successfully treated with the combination of advanced dermal substitute and direct-acting antiviral therapy. An 81-year-old female presented to our unit with a 6-month history of a leg ulcer that developed from an exudating skin nodule. At presentation, the lesion was large,caused a severe pain and was unresponsive to analgesics. Skin biopsy showed leukocytoclastic vasculitis. She had a history of old untreated HCV infection, hypertension, type 2 diabetes mellitus, chronic venous insufficiency and tibial arteriopathy. The application of porcine-derived dermal substitute achieved only initial improvement. Therefore, direct-acting antiviral therapy was started, and when HCV RNA became undetectable in blood, pain disappeared and skin ulcer improved up to healing. In conclusion vasculitic leg ulcers can be caused by HCV infection. In such cases, even the use of innovative skin therapy, may obtain only initial and partial improvement, and eradication of HCV viremiais essential to obtain wound healing.

Use of Porcine-Derived Dermal Substitutes for Treatment of Nonhealing Vascular Leg Ulcers: A Case Series.

Nonhealing leg ulcers are a major health problem worldwide with a high economic burden since they require human and material resources. Moreover, nonhealing ulcers are a major nontraumatic cause of lower limb amputations. Dermal substitutes have emerged as an effective therapeutic option for treatment of skin lesions, but data on leg ulcers are scarce. We evaluated safety and efficacy of a porcine-derived dermal substitute in the treatment of chronic vascular leg ulcers. Records of patients with nonhealing ulcers seen at our unit from 2018 to 2019 were retrospectively reviewed. Wound etiology, wound area, and complications were evaluated. Each patient received one application of porcine-derived dermal substitute and was followed-up. Six patients (5 females and 1 male) with a mean age of 61.3 (52-81) years presented with nonhealing leg ulcers. After surgical debridement and wound bed preparation, porcine-derived dermal substitute was applied onto the ulcer. Granulation was satisfactory within 10 days. All wounds healed after an average time of 14 weeks. Graft take was good, and no graft loss, rejection, or associated infection were observed. In conclusion, the data presented indicate that dermal substitutes are safe and effective for treatment of chronic nonhealing vascular leg ulcers.

The Impact of COVID-19 Pandemic on Vascular Leg Ulcers.

The aim of this study was to evaluate the impact of 2 lockdown periods during coronavirus disease 2019 (COVID-19) on the course and management of nonhealing vascular ulcers of lower limbs. A total of 41 patients were included in the study. Before the pandemic began they had been seen at our unit at weekly intervals. During lockdown from March 9, 2020, to May 18, 2020 subjects were not allowed to enter the hospital unless they needed urgency or emergency surgery, or oncological management. During the second lockdown, from October 19, 2020, to December 11, 2020 patients could be followed up at distance by direct outreach including telephoning contacts. Data obtained early after each lockdown were compared with those obtained prior to the pandemic. Data for the first lockdown show that pain intensified and there was an increase in the recurrence rate of wounds, of their severity, and of superimposed infections as compared with the prelockdown period. The risk of lower-limb amputation was also considerably greater. During the second and less restrictive lockdown, patients were followed up by telemedicine and data indicate that skin lesions had not worsened any further. The management of vascular wounds was impacted by the pandemic unfavorably with health care failures in the hospital as well as in the primary care settings. In conclusion, the treatment of vascular leg ulcers is challenged by the COVID-19 pandemic as this spreads worldwide. This seems to be in keeping with what happens for other diseases. The data we obtained indicate that the pandemic-related lockdown has a deleterious effect on vascular skin wounds, with an increase of severity and mortality risk. The impact appears to be proportional to the number and the degree of limitations imposed on people.

Use of a flowable wound matrix to treat lower limb vascular ulcers.

OBJECTIVES: This study is aimed at assessing the safety and effectiveness of an advanced flowable wound matrix (FWM) in the treatment of hard-to-heal vascular leg ulcers that often involve deep structures, are irregular and/or tunnelled or excavated. METHODS: Records of patients seen at our Vascular Surgery Unit, at the University of Campania 'Luigi Vanvitelli', for hard-to-heal vascular leg ulcers between January 2018 and January 2020 were retrospectively reviewed. For each wound aetiology, area and complications were recorded and evaluated. Every patient received one or more applications of FWM and was followed up. RESULTS: A total of 22 patients (18 female/four male), mean age 63±8.5 years, were treated. The initial wound area ranged from 4-58cm2. After wound bed preparation, FWM was applied. Treatment was well tolerated and effective-rate of complications was low, graft take was very satisfactory, and no graft loss, rejection or superimposed infections were observed. Healing time was short: 85% of ulcers healed after 12 weeks. Most importantly, there was a decrease in the rate and level of amputations as compared with standard wound care. CONCLUSIONS: The data presented indicate that FWM is an option for the treatment of hard-to-heal vascular leg ulcers, particularly for those with an irregular cavity. DECLARATION OF INTEREST: The authors have no conflicts of interest.

MRI T2-weighted sequences-based texture analysis (TA) as a predictor of response to neoadjuvant chemo-radiotherapy (nCRT) in patients with locally advanced rectal cancer (LARC).

PURPOSE: To determine whether MRI T2-weighted sequences-based texture analysis (TA) can predict histopathological tumor regression grade (TRG) in patients with locally advanced rectal cancer (LARC) undergoing neoadjuvant chemo-radiotherapy (nCRT). METHODS: Data on patients undergoing curative-intent surgery for LARC were collected. Patients with a complete pathological response, or TRG1 according to Mandard's system were classified as responders, while patients with TRG ≥ 2 were classified as non-responders. Tumor TA was performed on each patient's paraxial T2w MRI in both pre- and post-nCRT scans, in order to extract histograms, gray-level co-occurrence matrix (GLCM) and run-length matrix (RLM) texture parameters. For features that showed a significant difference between the two groups, a receiver operating characteristic (ROC) curve was drawn. RESULTS: Overall, 62 patients with LARC, treated with nCRT and resective surgery at our institution between 2013 and 2019 were identified. Only post-nCRT GLCM maximum probability showed a significant difference between the two groups (2909 ± 4479 in responders vs. 6515 ± 8990 in non- responders; p = 0.039); at the ROC curve, Youden index showed a sensitivity of 14% and a specificity of 100% for this parameter. CONCLUSIONS: MRI T2-weighted sequences-based TA was not effective in predicting pathological complete response to nCRT in patients with LARC. Further studies are needed to thoroughly investigate the potential of MRI TA in this setting.

CGF Treatment of Leg Ulcers: a Randomized Controlled Trial.

BACKGROUND: Concentrated Growth Factors (CGF) is a concentration of second generation autologous growth factors compared to platelet rich plasma (PRP) and represents a multifactorial stimulation system that can be used for the management and treatment of chronic skin ulcers. AIM: The aim of this work is to evaluate the additional benefits of the CGF compared to the standard of dressing and its effects on the dynamics of the healing process. METHODS: Autologous CGFs were obtained from 100 patients with chronic mixed ulcers (venous ulcers in patients with II stage claudication) of the lower limbs in a multicentric controlled randomized study. RESULTS: The results showed a significant advantage in the use of CGF in association with cleansing and selective compression in the healing time and stabilization of mixed ulcers of the lower extremities. CONCLUSIONS: These results support the CGF's clinical use for improving clinical outcomes in mixed ulcers of the legs.

Surgical Versus Sequential Hybrid Treatment of Carotid Body Tumors.

Carotid body tumor (CBT) are slow-growing tumors that develop in the cervical region at the carotid bifurcation. . In a randomized study, 33 patients were treated for CBT excision: 10 patients performed preoperative embolization (PE) and 23 were treated only by isolated traditional surgery (N-PE). The first group includes patients undergoing preoperative embolization. The second group of patients (N-PE) included 11 males and 12 females. Intraoperative complications were lower in patients treated with a hybrid procedure (PE): sections of the cranial nerves were recorded in 7% of cases compared to 12% of the surgical procedure (P-value = 0.72); while the reversible nerve lesions (P value = 0.21) and the permanent ones (P value = 0.46), were instead similar in both procedures. The comparative blood loss during the operative procedure shows a P-value of 0.02. Operating times, reversible damage of the cranial nerves , incidence of stroke (0% vs1%, P value> 0.99) and post-operative hospital stay (4.1 vs. 4.2 days, P value = 0.91) did not show differences in the two groups of patients. The analysis of the results detects pre-operative embolization of CBT in reducing intraoperative blood loss and resection of the cranial nerves..

Chronic hepatitis C virus infection and atherosclerosis: clinical impact and mechanisms.

Hepatitis C virus (HCV) infection represents a major health issue worldwide due to its burden of chronic liver disease and extrahepatic manifestations including cardiovascular diseases, which are associated with excess mortality. Analysis of published studies supports the view that HCV infection should be considered a risk factor for the development of carotid atherosclerosis, heart failure and stroke. In contrast, findings from studies addressing coronary artery disease and HCV have yielded conflicting results. Therefore, meta-analytic reviews and prospective studies are warranted. The pathogenic mechanisms connecting HCV infection, chronic liver disease, and atherogenesis are not completely understood. However, it has been hypothesized that HCV may promote atherogenesis and its complications through several direct and indirect biological mechanisms involving HCV colonization and replication within arterial walls, liver steatosis and fibrosis, enhanced and imbalanced secretion of inflammatory cytokines, oxidative stress, endotoxemia, mixed cryoglobulinemia, perturbed cellular and humoral immunity, hyperhomocysteinemia, hypo-adiponectinaemia, insulin resistance, type 2 diabetes and other components of the metabolic syndrome. Understanding these complex mechanisms is of fundamental importance for the development of novel therapeutic approaches to prevent and to treat vascular complications in patients with chronic HCV infection. Currently, it seems that HCV clearance by interferon and ribavirin treatment significantly reduces non-liver-related mortality; moreover, interferon-based treatment appears to decrease the risk of ischemic stroke.

Chronic HCV infection is a risk of atherosclerosis. Role of HCV and HCV-related steatosis.

OBJECTIVES: HCV and NAFLD are associated with atherosclerosis in general population. The prevalence of atherosclerosis in chronic hepatitis C (CHC) patients is unknown. We hypothesized that HCV per se and HCV-related steatosis could favour atherosclerosis. Thus, in CHC patients we assessed: (a) the prevalence of atherosclerosis; (b) the role of HCV, cardio-metabolic risk factors and hepatic histology. METHODS: Overall, 803 subjects were enrolled: (A) 326 patients with liver biopsy-proven treatment naive CHC (175 with and 151 without steatosis); (B) 477 age and gender matched controls, including 292 healthy subjects without steatosis (B1) and 185 with NAFLD (B2). Carotid atherosclerosis (CA), assessed by high-resolution B-mode ultrasonography, was categorized as either intima-media thickness (IMT: >1mm) or plaques (≥ 1.5mm). RESULTS: CHC patients had a higher prevalence of CA than controls (53.7% vs 34.3%; p<0.0001). Younger CHC (<50 years) had a higher prevalence of CA than controls (34.0% vs 16.0%; p<0.04). CHC patients without steatosis had a higher prevalence of CA than B1 controls (26.0% vs 14.8%; p<0.02). CHC with steatosis had a higher prevalence of CA than NAFLD patients (77.7% vs 57.8%, p<0.0001). Viral load was associated with serum CRP and fibrinogen levels; steatosis with metabolic syndrome, HOMA-IR, hyperhomocysteinemia and liver fibrosis. Viral load and steatosis were independently associated with CA. Diabetes and metabolic syndrome were associated with plaques. CONCLUSION: HCV infection is a risk factor for earlier and facilitated occurrence of CA via viral load and steatosis which modulate atherogenic factors such as inflammation and dysmetabolic milieu.

Beneficial effects of autologous bone marrow cell infusion and antioxidants/L-arginine in patients with chronic critical limb ischemia.

BACKGROUND: Short-term (within 6 weeks follow-up) clinical studies indicate that implantation of bone marrow cells (BMCs) into ischemic limbs may improve peripheral ischemia. Here, the long-term safety and feasibility of intraarterial autologous BMCs with oral treatment with antioxidants and L-arginine were investigated in patients with critical ischemia on account of advanced atherosclerotic peripheral arterial disease (PAD). METHODS: Eighteen patients with PAD (advanced III/IV Fontaine stages) were enrolled in this study (NCT00306085). An additional group of 18 patients taking maximal drug therapy that refused BMC therapy served as control. The BMC-treated group received two doses of BMCs in the leg arteries (time 0 and 45 days). After 30 days from the first BMC dose, patients received daily antioxidants, and L-arginine. Therapeutic neoangiogenesis was estimated by angiography and laser Doppler\capillaroscopy. RESULTS: Ankle brachial index improvement (DeltaABI: >0.1) was seen in 10 patients at 3 months and in 12 patients at 12-18 months. Ischemic ulcers improved in 13 patients (after 6-12 months). Although two patients underwent amputation, the mean maximum walking distance significantly increased at 3 months and was sustained up to 18 months. Among conservative patients, 10 underwent amputation in comparison with two BMC-treated patients (55.6 vs. 13.3%; P=0.014). CONCLUSION: This small study shows that intraarterial autologous BMC and antioxidants and L-arginine therapy is safe and effective in patients with advanced atherosclerotic PAD with positive effects until 18 months.

Therapeutic targeting of the stem cell niche in experimental hindlimb ischemia.

BACKGROUND: The custom microenvironment 'vascular niche' is a potential therapeutic target for several pathophysiological conditions. Osteoblasts regulate the hematopoietic stem cell niche, and activation of the parathyroid hormone (PTH) receptor can increase the number of cells mobilized into the bloodstream. METHODS: C57Bl/6 mice were randomly assigned treatment with granulocyte-colony stimulating factor (G-CSF), PTH, G-CSF plus PTH or saline. All mice underwent hindlimb ischemia. Blood flow was measured by laser Doppler imaging. Indices of capillary activity were determined by electron microscopy in muscle tissue. CD34(+) and Ki67(+) cells were detected and evaluated by immunofluorescence, apoptosis by TUNEL, surface antigen and endothelial progenitor cells by fluorescence-activated cell sorting analysis, and vascular endothelial growth factor-164 and angiopoietin-1 expression by reverse-transcriptase polymerase chain reaction. Frozen bone marrow sections were stained for antigen-specific B cells and fibronectin and analyzed by confocal laser scanning microscopy. RESULTS: Following mobilization induced by G-CSF treatment, mice also treated with PTH showed increases in blood flow, capillary density, nitrite/nitrate release, angiogenic factors and circulating progenitor cells, as well as reduced apoptosis, fibrosis, oxidative stress and inflammation in ischemic muscles. Furthermore, hematopoietic antigen-specific B cells in the bone marrow were also increased by G-CSF alone and in combination with PTH. CONCLUSIONS: PTH might increase the efficiency of hematopoietic stem-cell-based therapy in a recognized model of peripheral ischemia. Our translational experimental therapeutic targeting of the vascular niche points to novel clinical targets for the hematopoietic stem-cell treatment of ischemic vascular diseases.

Molecular epidemiology of high-level aminoglycoside-resistant enterococci isolated from patients in a university hospital in southern Italy.

OBJECTIVES: We evaluated the genetic and molecular basis of high-level resistance to gentamicin and amikacin in 91 clinical isolates of Enterococcus faecalis and Enterococcus faecium in a university hospital in southern Italy from 1987 to 2003. METHODS: Antibiotic susceptibility was evaluated by disc diffusion and microdilution methods. Genotyping was performed by PFGE and dendrogram analysis. Aminoglycoside resistance genes were analysed by multiplex PCR. Aminoglycoside resistance gene transfer was performed by filter mating. RESULTS: In our strain collection, 44% of E. faecalis and 52% of E. faecium were high-level-resistant to gentamicin. Fifty-two PFGE profiles were identified for E. faecalis and 15 for E. faecium. Although the majority of PFGE patterns were single isolates, four patterns (two for E. faecalis and two for E. faecium) were isolated each in 8 and 4, and 6 and 4 different patients, respectively. The aac(6')-Ie-aph(2'')-Ia gene was responsible for high-level resistance to gentamicin and amikacin in E. faecalis and E. faecium; the aph(2'')-Id gene responsible for resistance to gentamicin was also isolated in E. faecium; the aph(3')-IIIa and ant(4')-Ia genes responsible for resistance to amikacin were also isolated in E. faecalis and E. faecium. High-level resistance to gentamicin, along with the aac(6')-Ie-aph(2'')-Ia gene, was transferred at a frequency of about 10(-5) to 10(-8) per recipient cell in 14 of 17 E. faecalis and 3 of 4 E. faecium different genotypes. CONCLUSIONS: The spread of the aac(6')-Ie-aph(2'')-Ia gene was responsible for high-level resistance to gentamicin and amikacin among enterococci isolated from patients in our geographical area.