Coronary angioplasty in unstable angina. Immediate and short-term results

We report the results of percutaneous transluminal coronary angioplasty (PTCA) in 67 consecutive patients with unstable angina. Twenty patients had new onset (less than 2 months) angina, 33 patients had crescendo angina and 14 had early postinfarction angina. Fifty-one patients had one-vessel disease, 12 patients had two-vessel disease and two patients had three-vessel disease; two patients had a stenosis of a venous graft. In cases with multivessel disease, we performed only the dilatation of the ischaemia-related vessel identified by morphologic features of coronary lesion and electrocardiographic changes during chest pain. The procedure was successful in 54 cases (80.6%). Seven patients (10.4%) had major complications. Emergency coronary artery bypass graft surgery was performed in 6 cases (8.9%) because of occlusion of the left anterior descending artery; despite emergency operation one patient died and two patients sustained a myocardial infarction. One patient had occlusion of the right coronary artery and inferior myocardial infarction. In all patients in whom angioplasty was successful unstable angina disappeared. At 6 months follow-up there were no infarctions or deaths but 14 of 42 patients (33%) had recurrent angina. Restenosis occurred in 16 of 33 patients (48%) who had repeat coronary angiography. Four patients with recurrence of unstable angina had repeat angioplasty; it was successful in 3 cases. One patient died of refractory cardiac arrest. The mortality rate of 71 procedures performed in 67 patients was 2.8% (2/71) and the overall myocardial infarction rate was 4.2% (3/71).(ABSTRACT TRUNCATED AT 250 WORDS)     

A hidden layer of structural variation in transposable elements reveals potential genetic modifiers in human disease-risk loci

Genome-wide association studies (GWAS) have been highly informative in discovering disease-associated loci but are not designed to capture all structural variations in the human genome. Using long-read sequencing data, we discovered widespread structural variation within SINE-VNTR-Alu (SVA) elements, a class of great ape-specific transposable elements with gene-regulatory roles, which represents a major source of structural variability in the human population. We highlight the presence of structurally variable SVAs (SV-SVAs) in neurological disease–associated loci, and we further associate SV-SVAs to disease-associated SNPs and differential gene expression using luciferase assays and expression quantitative trait loci data. Finally, we genetically deleted SV-SVAs in the BIN1 and CD2AP Alzheimer''s disease–associated risk loci and in the BCKDK Parkinson''s disease–associated risk locus and assessed multiple aspects of their gene-regulatory influence in a human neuronal context. Together, this study reveals a novel layer of genetic variation in transposable elements that may contribute to identification of the structural variants that are the actual drivers of disease associations of GWAS loci.

Discovering the genetic variation underlying human diseases is a common goal in human genetics, and the rapid increase of genome-wide association studies (GWAS) has generated a vast catalog of single-nucleotide polymorphisms (SNPs) associated with specific traits and diseases (MacArthur et al. 2017). In most cases, GWAS do not identify the genetic variation that drives the trait but use SNPs as markers to highlight trait-associated loci through linkage disequilibrium (LD) (Edwards et al. 2013). This calls for elaborate post-GWAS analysis to shed light on the genes and mechanisms involved in specific traits (Backman et al. 2021; Mortezaei and Tavallaei 2021). A comprehensive view of the genetic structural variants that exist within loci containing trait-associated SNPs is an essential first step to assessing how these variants may lead to disease susceptibility on both genetic and functional levels (Eichler 2019).One source of structural variation that has not been sufficiently considered comes from transposable elements (TEs), which together constitute >42% of the human genome (Smit 1999; International Human Genome Sequencing Consortium 2001; Audano et al. 2019; Linthorst et al. 2020). Although the vast majority of TEs do not alter coding regions of our genome, some TE classes harbor strong gene regulatory potential that can directly affect gene expression levels (Jacobs et al. 2014; Wang et al. 2014; Chuong et al. 2016; Fuentes et al. 2018; Pontis et al. 2019). The TE-mediated regulatory effect on genes is highly tissue-specific and has been shown to be particularly prominent in a neuronal environment (Jacob-Hirsch et al. 2018; Trizzino et al. 2018; Pontis et al. 2019; Miao et al. 2020; Sundaram and Wysocka 2020). TEs are activated during aging, neurodegeneration, and neurological diseases, but whether this is a cause or a consequence of the disease pathology remains unknown in many cases (Frank et al. 2005; Li et al. 2013; Van Meter et al. 2014; Guo et al. 2018; Shpyleva et al. 2018).Only TEs of the Alu, L1, and SVA (SINE-VNTR-Alu) families can still actively spread through the genome, and new insertions cause variation between individuals in the form of presence/absence TE-insertional polymorphisms (Kazazian et al. 1988; Batzer et al. 1991; Brouha et al. 2003; Ostertag et al. 2003). TEs can alter gene regulation in the locus in which they insert, such that the presence or absence of a TE can lead to inter-individual differences in gene expression. There are approximately 60,475 Alu, 10,018 L1, and 6417 SVA TE-insertional polymorphisms known, with new insertions occurring every 40, 63, and 63 births, respectively (Feusier et al. 2019; Collins et al. 2020). Some of these new insertions have been linked to diseases (Makino et al. 2007; Hancks and Kazazian 2016; Sekar et al. 2016; Payer et al. 2017; Payer and Burns 2019; Pfaff et al. 2021). Next to presence/absence TE polymorphisms, structural variation within fixed TEs (TE insertions observed in all individuals in the human population) has also been reported (Savage et al. 2013, 2014), although the prevalence of this type of structural variation has remained elusive. The repetitive nature of TEs increases the propensity for unequal crossover events or DNA polymerase slippage during meiosis, for which variable number of tandem repeats (VNTRs) are especially susceptible (Brookes 2013). SVA elements harbor unusually large VNTRs as their internal segment and have a unique sequence composition compared to other VNTRs in our genome. The structural variation in VNTRs is particularly interesting because they are often associated with gene-regulatory functions, and many genes have accrued VNTRs as essential regulatory elements for their expression (International Human Genome Sequencing Consortium 2001; Fondon et al. 2008).It is becoming increasingly clear that gene-regulatory properties of TEs were co-opted during evolution, leading to the integration of TEs as novel gene-regulatory elements in preexisting gene expression networks (Cordaux and Batzer 2009; Chuong et al. 2016). As such, TEs have become an integral part of normal human gene regulation. Because our genome has become dependent on TEs for specific aspects of gene regulation, structural variation within fixed TEs could account for inter-individual differences in temporal or spatial aspects of gene expression. Despite the possible roles structurally variable TEs may play in human health or disease, this level of structural variation has remained largely undocumented. This is mainly a result of technical limitations associated with the highly repetitive DNA sequences within TEs, which makes identifying structural variations in TEs using short-read sequencing strategies extremely challenging. The development of long-read sequencing techniques provides, for the first time, the opportunity to accurately assess the level of structural variation (Eichler 2019). This allows for the evaluation of possible associations between disease susceptibility and specific structural variations found in fixed TEs in our genome (Audano et al. 2019; Chaisson et al. 2019; Sulovari et al. 2019; Ewing et al. 2020; Ebert et al. 2021; Porubsky et al. 2021).In this study we discovered that SVA retrotransposons, a great ape-specific class of TEs, constitutes a major source of hidden genetic variation that is not taken into account by conventional genetic case-control studies. We set out to investigate the biological consequences of structural variability in SVAs, focusing on SV-SVAs in Alzheimer''s disease (AD)– and Parkinson''s disease (PD)–associated GWAS loci. We assessed the gene-regulatory influence of SV-SVAs in a human neuronal context by genetic deletion of SVAs in three disease-associated loci. Our findings highlight the importance of careful mapping of structural variations within fixed TEs in the human population and argue for their inclusion in complex trait genetics as a layer of genetic variation that may, in some cases, confer the actual disease susceptibility to a GWAS-identified locus.     

DHPLC screening of ATM gene in Italian patients affected by ataxia-telangiectasia: fourteen novel ATM mutations

The gene for ataxia-telangiectasia (A-T:MIM: #208900), ATM, spans about 150 kb of genomic DNA and is composed of 62 coding exons. ATM mutations are found along the entire coding sequence of the gene, without evidence of mutational hot spots. Using DNA as the starting material, we used denaturing high performance liquid chromatography (DHPLC) technique to search for ATM gene mutations. Initially, DHPLC was validated in a retrospective study of 16 positive control samples that included 19 known mutations; 100% of mutations were detected. Subsequently, DHPLC was used to screen for mutations a cohort of 22 patients with the classical form of A-T. A total of 27 different mutations were identified on 38 of the 44 alleles, corresponding to a 86% detection rate. Fourteen of the mutations were novel. In addition, 15 different variants and polymorphisms of unknown functional significance were found. The high incidence of new and individual A-T mutations in our cohort of patients demonstrates marked mutational heterogeneity of A-T in Italy and corroborate the efficiency of DHPLC as a method for the mutation screening of A-T patients.     

The T-786C and Glu298Asp polymorphisms of the endothelial nitric oxide gene affect the forearm blood flow responses of Caucasian hypertensive patients

OBJECTIVES: We sought to investigate whether two polymorphisms located in the promoter (T(-786)C) and exon 7 (Glu298Asp) of the endothelial nitric oxide (NO) synthase (eNOS) gene affected agonists-mediated NO release. BACKGROUND: Endothelial dysfunction can be genetically determined. Therefore, we investigated whether two polymorphisms located in the eNOS gene affected agonists-mediated NO release. METHODS: We compared endothelial-dependent and -independent vasodilation of the different eNOS genotypes in a cross-sectional study on 187 subjects, of whom 137 were uncomplicated essential hypertensive patients (PH) (49 +/- 9 years, 151 +/- 11/99 +/- 5 mm Hg) and 50 healthy normotensive subjects (NT) (43 +/- 16 years, 123 +/- 10/78 +/- 7 mm Hg). Endothelial-dependent and -independent vasodilation was assessed as the forearm blood flow response to incrementally increasing doses of acetylcholine (0.15, 0.45, 1.5, 4.5, 15 microg/100 ml/min) and sodium nitroprusside (1, 2, 4 microg/100 ml/min), respectively. Genotyping was performed with melting curve analysis (Lightcycler) of polymerase chain reaction products from acceptor (5' end-labeled with LCRed 640) and donor probes (3' end-labeled with fluorescein) specific for each polymorphism.The genotype distribution of T(-786)C (CC = 21.9%, CT = 48.7%, TT = 29.4%) and Glu298Asp (GG = 39.0%, GT =51.9%, TT = 9.1%) was similar in PH and NT. A repeated measure analysis of variance showed a blunting of endothelium-dependent vasodilation in PH compared with NT (p < 0.001). A significant effect of the T(-786)C (p = 0.002) but not of the Glu298Asp (p = NS) eNOS polymorphism on endothelial-dependent vasodilation was found. However, we also detected a significant interaction between the T(-786)C and Glu298Asp polymorphism (p < 0.001). No effect on either polymorphism on endothelial-independent vasodilation was seen. CONCLUSIONS: The T(-786)C promoter polymorphism and its interaction with exon 7 Glu298Asp affect endothelium-dependent vasodilation in mild-to-moderate PH patients and NT Caucasian subjects.     

Circulating CD21low B cells in common variable immunodeficiency resemble tissue homing,innate-like B cells

The homeostasis of circulating B cell subsets in the peripheral blood of healthy adults is well regulated, but in disease it can be severely disturbed. Thus, a subgroup of patients with common variable immunodeficiency (CVID) presents with an extraordinary expansion of an unusual B cell population characterized by the low expression of CD21. CD21^low B cells are polyclonal, unmutated IgM⁺IgD⁺ B cells but carry a highly distinct gene expression profile which differs from conventional naïve B cells. Interestingly, while clearly not representing a memory population, they do share several features with the recently defined memory-like tissue, Fc receptor-like 4 positive B cell population in the tonsils of healthy donors. CD21^low B cells show signs of previous activation and proliferation in vivo, while exhibiting defective calcium signaling and poor proliferation in response to B cell receptor stimulation. CD21^low B cells express decreased amounts of homeostatic but increased levels of inflammatory chemokine receptors. This might explain their preferential homing to peripheral tissues like the bronchoalveolar space of CVID or the synovium of rheumatoid arthritis patients. Therefore, as a result of the close resemblance to the gene expression profile, phenotype, function and preferential tissue homing of murine B1 B cells, we suggest that CD21^low B cells represent a human innate-like B cell population.     

Structure of the meningococcal vaccine antigen NadA and epitope mapping of a bactericidal antibody

Serogroup B Neisseria meningitidis (MenB) is a major cause of severe sepsis and invasive meningococcal disease, which is associated with 5–15% mortality and devastating long-term sequelae. Neisserial adhesin A (NadA), a trimeric autotransporter adhesin (TAA) that acts in adhesion to and invasion of host epithelial cells, is one of the three antigens discovered by genome mining that are part of the MenB vaccine that recently was approved by the European Medicines Agency. Here we present the crystal structure of NadA variant 5 at 2 Å resolution and transmission electron microscopy data for NadA variant 3 that is present in the vaccine. The two variants show similar overall topology with a novel TAA fold predominantly composed of trimeric coiled-coils with three protruding wing-like structures that create an unusual N-terminal head domain. Detailed mapping of the binding site of a bactericidal antibody by hydrogen/deuterium exchange MS shows that a protective conformational epitope is located in the head of NadA. These results provide information that is important for elucidating the biological function and vaccine efficacy of NadA.The Gram-negative encapsulated bacterium Neisseria meningitidis causes severe sepsis and meningococcal meningitis. Invasive meningococcal disease (IMD) is associated with 5–15% mortality; furthermore, devastating long-term sequelae such as amputations, hearing loss, and neurodevelopmental disabilities are observed in 11–19% of IMD survivors (1). Meningococcal serogroups are distinguished by the composition of their capsular polysaccharides. The five serogroups most commonly associated with invasive disease are A, B, C, W, and Y. (2). Effective mono- or polyvalent-conjugated polysaccharide vaccines against N. meningitidis serogroups A, C, W, and Y have been available since the early 1990s (3). However, serogroup B meningococcus (MenB) is responsible for the majority of endemic and epidemic meningococcal disease in developed countries (4–6). The development of an efficient capsular polysaccharide-based vaccine against MenB has been hampered by potential autoimmunity issues, namely, the structural similarity between the MenB capsular polysaccharide and the neuraminic acid present on the surface of human fetal neural tissues (7).In early 2013 the European Medicines Agency approved 4CMenB, to our knowledge the first broadly protective vaccine against MenB, for the prevention of IMD in all age groups. 4CMenB is a multicomponent vaccine formulation composed of three surface-exposed meningococcal proteins originally identified by the reverse vaccinology approach (8) plus outer membrane vesicles from the New Zealand epidemic clone. The three antigenic proteins are factor H-binding protein (fHbp), neisserial heparin-binding antigen (NHBA), and neisserial adhesin A (NadA) (9, 10).The gene encoding NadA is present in ∼30% of pathogenic meningococcal isolates and is associated mostly with strains that belong to three of the four hypervirulent serogroup B lineages (11–14). NadA expression levels can vary among isolates by more than 100-fold, and its expression is up-regulated in vivo by niche-specific signals (15). NadA induces high levels of bactericidal antibodies in humans (16–18) and is recognized by serum antibodies of children convalescent after IMD (19), suggesting that it is expressed and is immunogenic during IMD. Two main genetically distinct groups of NadA have been identified that share overall amino acid sequence identities of 45–50%. Group I includes the three most common variants (NadA1, NadA2, and NadA3, the latter being the vaccine variant), which share ∼95% sequence identity and are immunologically cross-reactive (11). Group II includes three rarer variants: NadA4, primarily associated with carriage strains (11); NadA5, found mainly in strains of clonal complex 213 (20, 21); and NadA6 (Fig. S1A); these three share ∼90% sequence identity (Fig. S1B) (22).Functionally, NadA3 expressed on the surface of Escherichia coli promotes adhesion to and invasion of Chang epithelial cells (23). This adhesive activity has been mapped, at least partially, to an N-terminal region extending to residue T132 (23, 24). Recently, interactions of NadA3 with β-1 integrin (25) and with the heat shock protein Hsp90 (26) have been reported.Structurally, NadA belongs to the class of trimeric autotransporter adhesins (TAAs) (27, 28), which are known to mediate adhesion through interaction with extracellular matrix proteins and are involved in invasion of target cells (29). TAAs are obligate homotrimers, and accordingly the recombinant NadA3 vaccine antigen, lacking the C-terminal membrane anchor region, forms soluble, stable trimers (23, 30). TAAs generally are made of a conserved C-terminal integral membrane β-barrel, which anchors the proteins to the outer membrane, and an N-terminal “passenger” domain responsible for adhesion (31). The TAA passenger domain typically is made of a central α-helical domain (stalk) that forms coiled-coil structures and a distinct N-terminal domain (head) that is mainly responsible for binding to host cellular receptors.Here we present the X-ray structure of a large ectodomain fragment of NadA5 and a structural analysis by transmission electron microscopy (TEM) of the vaccine variant NadA3. In addition, epitope mapping shows that the head of NadA3 contains immunogenic regions responsible for the generation of a protective bactericidal response.     

Rhythmic tongue movements during sleep: a peculiar parasomnia in Costello syndrome.

We describe a peculiar parasomnia observed in four Costello infants, characterized by periodic rhythmic movements of the tongue. Ten Costello patients (4 male; age range 9 months to 29 years) underwent 1 full-night laboratory-based video polysomnography. The four youngest patients (2 male and 2 female; age range 9-31 months) presented during sleep repeated stereotyped movements of the tongue, producing a sucking-like or licking-like movement, mostly during non-rapid eye movement (NREM) sleep. Rhythmic tongue movements in Costello syndrome show the features of an NREM sleep parasomnia. Tongue movements during sleep probably originate from brainstem structures and could be facilitated by an impaired control of the oropharyngeal and tongue muscles.     

What explains between-school differences in rates of sexual experience?

Background  

Schools have the potential to influence their pupils' behaviour through the school's social organisation and culture, as well as through the formal curriculum. This paper provides the first attempt to explain the differences between schools in rates of reported heterosexual sexual experience amongst 15 and 16 year olds. It first examined whether variations in rates of sexual experience remained after controlling for the known predictors of sexual activity. It then examined whether these residuals, or 'school effects', were attributable to processes within the school, or were more likely to reflect characteristics of the neighbourhood.