VID22 counteracts G-quadruplex-induced genome instability.

Genome instability is a condition characterized by the accumulation of genetic alterations and is a hallmark of cancer cells. To uncover new genes and cellular pathways affecting endogenous DNA damage and genome integrity, we exploited a Synthetic Genetic Array (SGA)-based screen in yeast. Among the positive genes, we identified VID22, reported to be involved in DNA double-strand break repair. vid22Δ cells exhibit increased levels of endogenous DNA damage, chronic DNA damage response activation and accumulate DNA aberrations in sequences displaying high probabilities of forming G-quadruplexes (G4-DNA). If not resolved, these DNA secondary structures can block the progression of both DNA and RNA polymerases and correlate with chromosome fragile sites. Vid22 binds to and protects DNA at G4-containing regions both in vitro and in vivo. Loss of VID22 causes an increase in gross chromosomal rearrangement (GCR) events dependent on G-quadruplex forming sequences. Moreover, the absence of Vid22 causes defects in the correct maintenance of G4-DNA rich elements, such as telomeres and mtDNA, and hypersensitivity to the G4-stabilizing ligand TMPyP4. We thus propose that Vid22 is directly involved in genome integrity maintenance as a novel regulator of G4 metabolism.

Epididymal cyst in children.

The terms "epididymal cyst" and "spermatocele" are commonly used to describe the same entity, but, conversely, they are slightly different. Epididymal cyst is a benign mass, and it is more common than previously thought in prepubertal age. Pathogenic mechanisms for epididymal cyst have not been fully clarified yet, even if epididymal cysts have been reported in association with other malformations of the urinary tract or complex syndromes. Epididymal cyst is easily characterized and differentiated from spermatocele using ultrasound imaging. Conservative management constitutes the treatment of choice in the majority of cases, and surgery is recommended only in selected cases. Conclusion: To date, a review on epididymal cyst in childhood is lacking in the literature. Herein, an overview of knowledge about epididymal cyst in children has been carried out with particular attention to differential diagnosis, proper management, and practice guidelines for caregivers of children who may present with an epididymal cyst. What is Known: • Epididymal cyst is a benign sac in the testicles which is usually asymptomatic. • Epididymal cyst is easily diagnosed by ultrasound scans, and it is considered a self-limiting disease in the majority of cases. What is New: • Insight on differential diagnosis between epididymal cyst and spermatocele. • Valuable knowledge on the best management strategy for epididymal cyst and on practice guidelines for parents of children presenting with epididymal cyst.

Backbone-free duplex-stacked monomer nucleic acids exhibiting Watson-Crick selectivity.

We demonstrate that nucleic acid (NA) mononucleotide triphosphates (dNTPs and rNTPs), at sufficiently high concentration and low temperature in aqueous solution, can exhibit a phase transition in which chromonic columnar liquid crystal ordering spontaneously appears. Remarkably, this polymer-free state exhibits, in a self-assembly of NA monomers, the key structural elements of biological nucleic acids, including: long-ranged duplex stacking of base pairs, complementarity-dependent partitioning of molecules, and Watson-Crick selectivity, such that, among all solutions of adenosine, cytosine, guanine, and thymine NTPs and their binary mixtures, duplex columnar ordering is most stable in the A-T and C-G combinations.

A novel Xp22.13 microdeletion in Nance-Horan syndrome.

BACKGROUND: Nance-Horan syndrome (NHS) is a rare X-linked developmental disorder characterized by congenital cataract, dental anomalies and facial dysmorphisms. Notably, up to 30% of NHS patients have intellectual disability and a few patients have been reported to have congenital cardiac defects. Nance-Horan syndrome is caused by mutations in the NHS gene that is highly expressed in the midbrain, retina, lens, tooth, and is conserved across vertebrate species. Although most pathogenic mutations are nonsense mutations, a few genomic rearrangements involving NHS locus have been reported, suggesting a possible pathogenic role of the flanking genes. METHODS: Here, we report a microdeletion of 170,6 Kb at Xp22.13 (17.733.948-17.904.576) (GRCh37/hg19), detected by array-based comparative genomic hybridization in an Italian boy with NHS syndrome. RESULTS: The microdeletion harbors the NHS, SCLML1, and RAI2 genes and results in a phenotype consistent with NSH syndrome and developmental delay. CONCLUSION: We compare our case with the previous Xp22.13 microdeletions and discuss the possible pathogenetic role of the flanking genes. Birth Defects Research 109:866-868, 2017. © 2017 Wiley Periodicals, Inc.

Platinum-Based Drugs and DNA Interactions Studied by Single-Molecule and Bulk Measurements.

Platinum-containing molecules are widely used as anticancer drugs. These molecules exert cytotoxic effects by binding to DNA through various mechanisms. The binding between DNA and platinum-based drugs hinders the opening of DNA, and therefore, DNA duplication and transcription are severely hampered. Overall, impeding the above-mentioned important DNA mechanisms results in irreversible DNA damage and the induction of apoptosis. Several molecules, including multinuclear platinum compounds, belong to the family of platinum drugs, and there is a body of research devoted to developing more efficient and less toxic versions of these compounds. In this study, we combined different biophysical methods, including single-molecule assays (magnetic tweezers) and bulk experiments (ultraviolet absorption for thermal denaturation) to analyze the differential stability of double-stranded DNA in complex with either cisplatin or multinuclear platinum agents. Specifically, we analyzed how the binding of BBR3005 and BBR3464, two representative multinuclear platinum-based compounds, to DNA affects its stability as compared with cisplatin binding. Our results suggest that single-molecule approaches can provide insights into the drug-DNA interactions that underlie drug potency and provide information that is complementary to that generated from bulk analysis; thus, single-molecule approaches have the potential to facilitate the selection and design of optimized drug compounds. In particular, relevant differences in DNA stability at the single-molecule level are demonstrated by analyzing nanomechanically induced DNA denaturation. On the basis of the comparison between the single-molecule and bulk analyses, we suggest that transplatinated drugs are able to locally destabilize small portions of the DNA chain, whereas other regions are stabilized.

A mild form of rituximab-associated lung injury in two adolescents treated for nephrotic syndrome.

Rituximab is used as a steroid/calcineurin inhibitor-saving agent in patients with nephrotic syndrome. Safety is a crucial issue for justifying widespread use of the drug in this clinical setting. Rituximab-associated lung injury (RALI) is a severe and potentially life-threatening complication in oncohaematological and rheumatological patients, while it has only been anecdotally reported in association with idiopathic nephrotic syndrome (2 cases described, 1 with fatal outcome). We describe a benign form of RALI occurring in two adolescents treated with rituximab (single pulse of 375 mg/m(2)) for nephrotic syndrome. Before treatment, the patients were in good clinical condition while receiving a combination of steroids and calcineurin inhibitors (tacrolimus, case 1 and cyclosporine, case 2). The two patients developed full blown RALI (ie, ground-glass lesions on CT, negative bronchoscopy with bronchoalveolar lavage and deficit in diffusion lung CO transfer), 14 and 40 days after rituximab infusion, respectively. Recovery was rapid and complete after administering steroids in case 1 and with no therapy in case 2. We conclude that RALI may occur in stable non-immunocompromised patients with nephrotic syndrome and its frequency may be higher than expected. Clinical presentation may be mild and resolve after steroids, suggesting hypersensitivity as the main mechanism. Rapid recognition and prompt steroid therapy, if needed, are mandatory for resolution.

Etiology of non-immune hydrops fetalis: An update.

Hydrops fetalis is an excessive fluid accumulation within the fetal extra vascular compartments and body cavities. Non-immune hydrops fetalis (NIHF), due to causes other than Rh alloimmunization, is the cause in >85% of all affected individuals. Herein we present an update of our earlier systematic literature review [Bellini et al., 2009] using all publications between 2007 and 2013. We excluded most of the initial 31,783 papers by using strict selection criteria, thus resulting in 24 relevant NIHF publications describing 1,338 individuals with NIHF. We subdivided the affected individuals into 14 classification groups based on the cause of NIHF (percentage of the total group): Cardiovascular (20.1%), Hematologic (9.3%), Chromosomal (9.0%), Syndromic (5.5%), Lymphatic Dysplasia (15.0%), Inborn Errors of Metabolism (1.3%), Infections (7.0%), Thoracic (2.3%), Urinary Tract Malformations (0.9%), Extra Thoracic Tumors (0.7%), TTTF-Placental (4.1%), Gastrointestinal (1.3%), Miscellaneous (3.6%), Idiopathic (19.8%). We discuss the results of the review. There may be some shifts in the percentages of etiological categories as compared to the previous review, but the small numbers within each category make drawing firm conclusions hazardous. We highlight the need for multi-center series of NIHF cases collected and classified using the same schemes in diagnostic work-ups to allow for comparisons of larger numbers of cases.

Intraepithelial lymphocyte eotaxin-2 expression and perineural mast cell degranulation differentiate allergic/eosinophilic colitis from classic IBD.

OBJECTIVES: Allergic colitis shows overlap with classic inflammatory bowel disease (IBD). Clinically, allergic colitis is associated with dysmotility and abdominal pain, and mucosal eosinophilia is characteristic. We thus aimed to characterise mucosal changes in children with allergic colitis compared with normal tissue and classic IBD, focusing on potential interaction between eosinophils and mast cells with enteric neurones. METHODS: A total of 15 children with allergic colitis, 10 with Crohn disease (CD), 10 with ulcerative colitis (UC), and 10 histologically normal controls were studied. Mucosal biopsies were stained for CD3 T cells, Ki-67, eotaxin-1, and eotaxin-2. Eotaxin-2, IgE, and tryptase were localised compared with mucosal nerves, using neuronal markers neurofilament protein, neuron-specific enolase, and nerve growth factor receptor. RESULTS: Overall inflammation was greater in patients with CD and UC than in patients with allergic colitis. CD3 T-cell density was increased in patients with allergic colitis, similar to that in patients with CD but lower than in patients with UC, whereas eosinophil density was higher than in all other groups. Eotaxin-1 and -2 were localised to basolateral crypt epithelium in all specimens, with eotaxin-1+ lamina propria cells found in all of the colitis groups. Eotaxin-2+ intraepithelial lymphocyte (IEL) density was significantly higher in allergic colitis specimens than in all other groups. Mast cell degranulation was strikingly increased in patients with allergic colitis (12/15) compared with that in patients with UC (1/10) and CD (0/1). Tryptase and IgE colocalised on enteric neurons in patients with allergic colitis but rarely in patients with IBD. CONCLUSIONS: Eotaxin-2+ IELs may contribute to the periepithelial eosinophil accumulation characteristic of allergic colitis. The colocalisation of IgE and tryptase with mucosal enteric nerves is likely to promote the dysmotility and visceral hyperalgesia classically seen in allergic gastrointestinal inflammation.

Immunohistochemistry in non-immune hydrops fetalis: a single center experience in 79 fetuses.

The objective of our study was to evaluate the usefulness of immunohistochemical (IHC) staining techniques in the etiological diagnosis of non-immune hydrops fetalis (NIHF). The records of all 1,098 autopsies performed between January 1987 and May 2008, by the Division of Fetal Pathology of the University of Genoa, were reviewed and all 79 fetuses diagnosed with NIHF were re-evaluated. Additional IHC staining using antibodies that specifically stain blood and lymph vessels (CD31, CD34, smooth muscle actin antibody, D2-40) were performed. Results were compared to results from the literature. Our results showed that in 67/79 cases, evaluation by standard autopsy protocol led to an etiologic diagnosis. Furthermore, we were able to identify the pathogenetic mechanisms that eventually caused NIHF in 42/79 cases. Adding IHC staining to all evaluations identified the pathogenetic mechanism in a further 17 cases (total 59/79 cases). Lymphatic dysplasia was diagnosed by standard autopsy protocol in 1/79 (1.3%), while adding IHC staining resulted in 18/79 (22.8%) cases being diagnosed (P = 0.0001). The present rate of 22.8% of lymphatic dysplasia in non-immune hydrops fetalis is significantly higher than reported in the literature (36/818 or 4.4%; P = 0.01). In conclusion, specific IHC staining techniques aimed at detecting lymphatic dysplasia are needed and should be mandatory in autopsies of fetuses with non-immune hydrops fetalis.

Nuchal translucency and lymphatic system maldevelopment.

We describe the histological examination of 18 aborted fetuses that had increased nuchal translucency (NT) between 11(+0) and 13(+6) weeks' gestation. The aim of this study was to assess the corresponding NT anatomic features by immunohistochemical (IHC) investigation. A morphological study was performed using lymphatic and blood endothelial specific markers, as well as smooth muscle actin (SMA). We found that all 18 cases were D2-40 positive, CD31 positive, and CD34 negative, suggesting the presence of nuchal lymph vessel ectasia. We found that 12/18 cases were SMA staining positive and 6/18 cases were SMA negative, suggesting that 6/18 cases had nuchal cystic lymphangiectasia, whereas 12/18 had cystic hygromas. The present data seem to confirm the reasonable hypothesis that lymphangiogenesis plays a relevant role in nuchal edema, increased NT, and that increased NT is the result of a lymphatic malformation or a delayed development of the lymphatic system.

Kinetics of contact formation and end-to-end distance distributions of swollen disordered peptides.

Unstructured polypeptide chains are subject to various degrees of swelling or compaction depending on the combination of solvent condition and amino acid sequence. Highly denatured proteins generally behave like random-coils with excluded volume repulsion, whereas in aqueous buffer more compact conformations have been observed for the low-populated unfolded state of globular proteins as well as for naturally disordered sequences. To quantitatively account for the different mechanisms inducing the swelling of polypeptides, we have examined three 14-residues peptides in aqueous buffer and in denaturant solutions, including the well characterized AGQ repeat as a reference and two variants, in which we have successively introduced charged side chains and removed the glycines. Quenching of the triplet state of tryptophan by close contact with cysteine has been used in conjunction with Förster resonance energy transfer to study the equilibrium and kinetic properties of the peptide chains. The experiments enable accessing end-to-end root mean-square distance, probability of end-to-end contact formation and intrachain diffusion coefficient. The data can be coherently interpreted on the basis of a simple chain model with backbone angles obtained from a library of coil segments of proteins and hard sphere repulsion at each Calpha position. In buffered water, we find that introducing charges in a glycine-rich sequence induces a mild chain swelling and a significant speed-up of the intrachain dynamics, whereas the removal of the glycines results in almost a two-fold increase of the chain volume and a drastic slowing down. In denaturants we observe a pronounced swelling of all the chains, with significant differences between the effect of urea and guanidinium chloride.