Induction of unstable alleles at the temperature-sensitive Virescent-1 gene of maize using the transposable element Dissociation

SummaryTranspositive mutagenesis was employed to prepare genetic strains useful in cloning theVirescent-1locus (V1) of maize. A stepwise approach was used based on: (1) the isolation of putative insertion phenotypes (62 cases); (2) the verification of the genetic nature of the selected events (36v1-mmutant alleles induced); (3) the accurate genetic study of 11 alleles; (4) the genetic assessment that the allelesv1-m1andv1-m4are due to the insertion ofa Dselement into the locusV1; (5) the proof that aDs-like DNA element induces the inactivation of the wild type function in the allelev1-m1. The phenotype of the unstable alleles, studied by germinating and keeping maize seedlings at the temperature of 18 °C, are the following: allelesv1-m1, v1-m9, v1-m11, v1-m17andv1-m18showing a few revertant green sectors on their leaves;v1-m4exhibiting a reverse type of variegation; allelesv1-m2andv1-m13with a coarse pattern of variegation; allelesv1-m12, v1-m21andv1-m23frequently showing leaves part green with white stripes and part white with green stripes. For the alleles studied, in addition to somatic instability, germinal reversions also occurred. In some cases, these reversions resulted in stable derivatives with a different colour from that of the wild-type ('near green' or pale phenotypes). The results presented not only allow thev1-m1allele to be chosen as a starting material for cloning theV1locus, but also define the molecular strategy to be followed

Non-Traditional Systemic Treatments for Diabetic Retinopathy : AnEvidence-Based Review

The rapid escalation in the global prevalence diabetes, with more than 30% being afflicted with diabetic retinopathy (DR), means it is likely that associated vision-threatening conditions will also rise substantially. This means that new therapeutic approaches need to be found that go beyond the current standards of diabetic care, and which are effective in the early stages of the disease. In recent decades several new pharmacological agents have been investigated for their effectiveness in preventing the appearance and progression of DR or in reversing DR; some with limited success while others appear promising. This up-to-date critical review of non-traditional systemic treatments for DR is based on the published evidence in MEDLINE spanning 1980-December 2014. It discusses a number of therapeutic options, paying particular attention to the mechanisms of action and the clinical evidence for the use of renin-angiotensin system blockade, fenofibrate and calcium dobesilate monohydrate in DR

Dysbiosis in Pediatrics Is Associated with Respiratory Infections: Is There a Place for Bacterial-Derived Products?

Respiratory tract infections (RTIs) are common in childhood because of the physiologic immaturity of the immune system, a microbial community under development in addition to other genetic, physiological, environmental and social factors. RTIs tend to recur and severe lower viral RTIs in early childhood are not uncommon and are associated with increased risk of respiratory disorders later in life, including recurrent wheezing and asthma. Therefore, a better understanding of the main players and mechanisms involved in respiratory morbidity is necessary for a prompt and improved care as well as for primary prevention. The inter-talks between human immune components and microbiota as well as their main functions have been recently unraveled; nevertheless, more is still to be discovered or understood in the above medical conditions. The aim of this review paper is to provide the most up-to-date overview on dysbiosis in pre-school children and its association with RTIs and their complications. The potential role of non-harmful bacterial-derived products, according to the old hygiene hypothesis and the most recent trained-innate immunity concept, will be discussed together with the need of proof-of-concept studies and larger clinical trials with immunological and microbiological endpoints

Met protein and hepatocyte grwth factor (HGF) in papillary carcinoma of the thyroid: evidence for a pathogenetic role in tumorigenesis.

In the last 10 years, evidence has accumulated that overexpression of Met protein is a distinguishing feature of almost every case of well-differentiated papillary carcinoma. Increased expression of the protein is probably due to enhanced transcription of the MET gene and/or to post-transcriptional mechanisms. So far, alterations of the MET gene have not been recognized, but evidence has been provided that activated RAS and RET can cause accumulation of MET RNA. Thus, the possibility exists that dysregulation of MET is the final result of different molecular pathways capable of inducing thyroid cell transformation; RET rearrangements might account for some of the cases, but the demonstration that the majority of papillary carcinomas do not have recognized alterations of the RET gene strongly suggests that MET gene dysregulation can also be achieved through other molecular pathways. Dysregulation of MET causes marked accumulation of Met protein in tumour cells that is promptly detected by immunohistochemistry. Thus, overexpression of Met protein might represent an immunohistochemical marker of papillary carcinoma, potentially helpful in problematic cases, but caution is required; moderate expression of Met protein is observed in non-neoplastic thyroid diseases, such as Graves' and Hashimoto's thyroiditis, and reagents active on paraffin sections may have a low affinity and/or low specificity for Met protein, leading to artifactual staining. Met protein-positive papillary carcinoma cells may produce hepatocyte growth factor (HGF) and may activate HGF through the urokinase-type plasminogen activator (uPA) bound to urokinase-type plasminogen activator receptor (uPA-R). Thus, papillary carcinoma cells possess the molecular machinery necessary for a productive HGF/Met interaction. In vitro studies have demonstrated that HGF enhances the motility and invasiveness of tumour cells and induces the synthesis and release of chemokines active in the recruitment of dendritic cells. These observations provide a rational basis for the understanding of two distinguishing features of papillary carcinoma. First, the tumour is often characterized by early metastatic spread to regional lymph nodes and by multifocal involvement of the gland, which suggests highly invasive behaviour. Second, a prominent peritumoural inflammatory reaction is often observed, which suggests cross-talk between tumour cells and the immune system

Viral infections and wheezing–asthma inception in childhood: is there a role for immunomodulation by oral bacterial lysates?

Severe and recurrent infections of the respiratory tract in early childhood constitute major risk factors for the development of bronchial hyper-responsiveness and obstructive respiratory diseases in later life. In the first years of life, the vast majority of respiratory tract infections (RTI) leading to wheezing and asthma are of a viral origin and severity and recurrence are the consequence of a greater exposure to infectious agents in a period when the immune system is still relatively immature. Therefore, boosting the efficiency of the host immune response against viral infections seems to be a rational preventative approach. In the last decades it has been demonstrated that living in farm environments, i.e. early-life exposure to microbes, may reduce the risk of allergic and infectious disorders, increasing the immune response efficacy. These findings have suggested that treatment with bacterial lysates could promote a nonspecific immunomodulation useful in the prevention of recurrent RTIs and of wheezing inception and persistence. Experimental and clinical studies showing the reduction of RTI frequency and severity in childhood and elucidating the involved mechanisms can support this hypothesis

Social and economic burden of recurrent urinary tract infections and quality of life : a patient web-based study (GESPRIT)

Background: Uncomplicated lower urinary tract infections (UTIs) occur in approximately 50% of women, and 20–30% experience recurrent UTI. Data on UTIs and quality of life (QoL) in Europe are limited. Methods: This was an anonymous, self-administered web-based survey conducted in 5 countries (Germany, Switzerland, Poland, Russia and Italy), on adult women who had experienced recurrent UTI and were affected by acute UTI currently or within 4 weeks of study entry. Questions covered disease course; management; social and economic burden; education, income, and health insurance status. QoL was evaluated using the SF-12v2. Results: Participants reported a mean of 5.15 UTI symptoms, ranging from 4.85 − 5.38 in Russia and Germany. There was a mean of 2.78 doctor visits per year (1.74 − 3.71 in Russia and Germany; p < 0.0001). 80.3% of participants had been treated with antibiotics, mean prescriptions ranged from 2.17 (Poland) to 3.36 (Germany) per person per year. A mean of 3.09 days sick leave due to UTIs, and 3.45 days of limited activities, were reported. Although 73.8% of participants had tried prophylaxis recurrence was common and associated with mental stress for a high proportion of women. Conclusions: Our results indicate that recurrent UTIs have a significant impact on QoL of women in Europe

Alarmins and innate lymphoid cells 2 activation: A common pathogenetic link connecting respiratory syncytial virus bronchiolitis and later wheezing/asthma?

Severe respiratory syncytial virus (RSV) infection in infancy is associated with increased risk of recurrent wheezing in childhood. Both acute and long‐term alterations in airway functions are thought to be related to inefficient antiviral immune response. The airway epithelium, the first target of RSV, normally acts as an immunological barrier able to elicit an effective immune reaction but may also be programmed to directly promote a Th2 response, independently from Th2 lymphocyte involvement. Recognition of RSV transcripts and viral replication intermediates by bronchial epithelial cells brings about release of TSLP, IL‐33, HMGB1, and IL‐25, dubbed “alarmins.” These epithelial cell‐derived proteins are particularly effective in stimulating innate lymphoid cells 2 (ILC2) to release IL‐4, IL‐5, and IL‐13. ILC2, reflect the innate counterparts of Th2 cells and, when activate, are potent promoters of airway inflammation and hyperresponsiveness in RSV bronchiolitis and childhood wheezing/asthma. Long‐term epithelial progenitors or persistent epigenetic modifications of the airway epithelium following RSV infection may play a pathogenetic role in the short‐ and long‐term increased susceptibility to obstructive lung diseases in response to RSV in the young. Additionally, ILC2 function may be further regulated by RSV‐induced changes in gut microbiota community composition that can be associated with disease severity in infants. A better understanding of the alarmin‐ILC interactions in childhood might provide insights into the mechanisms characterizing these immune‐mediated diseases and indicate new targets for prevention and therapeutic interventions

Microbiota profiles in pre-school children with respiratory infections: Modifications induced by the oral bacterial lysate OM-85

To describe microbiota profiles considering potential influencing factors in pre-school children with recurrent respiratory tract infections (rRTIs) and to evaluate microbiota changes associated with oral bacterial lysate OM-85 treatment, we analyzed gut and nasopharynx (NP) microbiota composition in patients included in the OM-85-pediatric rRTIs (OMPeR) clinical trial (https://www.clinicaltrialsregister.eu/ctr-search/trial/2016-002705-19/IT). Relative percentage abundance was used to describe microbiota profiles in all the available biological specimens, grouped by age, atopy, and rRTIs both at inclusion (T0) and at the end of the study, after treatment with OM-85 or placebo (T1). At T0, Firmicutes and Bacteriodetes were the predominant genera in gut and Proteobacteria, Firmicutes, and Actinobacteria were the predominant genera in NP samples. Gut microbiota relative composition differed with age (&lt;2 vs. &gt;= 2 years) for Firmicutes, Proteobacteria, Actinobacteria (phyla) and Bifidobacterium, Ruminococcus, Lachnospiraceae (genera) (p &lt; 0.05). Moraxella was more enriched in the NP of patients with a history of up to three RTIs. Intra-group changes in relative percentage abundance were described only for patients with gut and NP microbiota analysis available at both T0 and T1 for each study arm. In this preliminary analysis, the gut microbiota seemed more stable over the 6-month study in the OM-85 group, whose mean age was lower, as compared to the placebo group (p = 0.004). In this latter group, the relative abundance of Bacteroides decreased significantly in children &gt;= 2 years. Some longitudinal significant differences in genera relative abundance were also detected in children of &gt;= 2 years for NP Actinobacteria, Haemophilus, and Corynebacterium in the placebo group only. Due to the small number of patients in the different sub-populations, we could not identify significant differences in the clinical outcome and therefore no associations with microbiota changes were searched. The use of bacterial lysates might play a role in microbiota rearrangement, but further data and advanced analysis are needed to prove this in less heterogeneous populations with higher numbers of samples considering the multiple influencing factors such as delivery method, age, environment, diet, antibiotic use, and type of infections to ultimately show any associations with prevention of rRTIs