A hypervariable intron of the STAYGREEN locus provides excellent discrimination among Pisum fulvum accessions and reveals evidence for a relatively recent hybridization event with Pisum sativum

An analysis of 82 non-synonymous Pisum fulvum accessions for sequence variation in a fragment of the STAYGREEN (SGR) locus revealed 57 alleles, most of which differed in indel structure. Eight additional P. fulvum accessions, each supposedly synonymous with a different accession of the initial group, were also analyzed. In every case the paired synonymous accessions possessed the same SGR sequence but varied slightly for a 6-trait morphological phenotype, indicating that SGR sequence is a much more reliable indicator of accession identity than is a morphological characterization. SGR sequence analysis confirmed our previous finding that P. fulvum accessions separate into two allele groups. This division was not supported by results of previous studies that were based on sequences distributed across the entire genome, suggesting that the division may have been produced by selection at a nearby locus and that the SGR phylogeny may not be good indicator of overall relationships within the species. One P. fulvum accession, PI 595941 (=JI1796), displayed an SGR sequence outside the variation typical of the species. Instead, its allele resembled alleles limited to a set of Pisum sativum landraces from the Middle East, suggesting hybridization between ancestors of PI 595941 and some primitive form of domesticated P. sativum. With one exception from the extreme northwest corner of Israel, P. fulvum accessions collected north of latitude 35.5° N were fixed for alleles from group A. These northern accessions also displayed greatly reduced SGR sequence diversity compared to group A accessions collected from other regions, suggesting that the northern populations may represent recent extensions of the range of the species. Group B accessions were distributed from Lake Tiberias south and were generally sympatric with the southern group A accessions. Although group B accessions occupied a smaller area than group A, the SGR sequence diversity in this group (28 alleles in 33 accessions) exceeded that for group A.

Endothelial cell activation, Weibel-Palade body secretion, and enhanced angiogenesis in severe COVID-19

Background

Severe COVID-19 is associated with marked endothelial cell (EC) activation that plays a key role in immunothrombosis and pulmonary microvascular occlusion. However, the biological mechanisms through which SARS-CoV-2 causes EC activation and damage remain poorly defined.

Objectives

We investigated EC activation in patients with acute COVID-19, and specifically focused on how proteins stored within Weibel-Palade bodies may impact key aspects of disease pathogenesis.

Methods

Thirty-nine patients with confirmed COVID-19 were recruited. Weibel-Palade body biomarkers (von Willebrand factor [VWF], angiopoietin-2 [Angpt-2], and osteoprotegerin) and soluble thrombomodulin (sTM) levels were determined. In addition, EC activation and angiogenesis were assessed in the presence or absence of COVID-19 plasma incubation.

Results

Markedly elevated plasma VWF antigen, Angpt-2, osteoprotegerin, and sTM levels were observed in patients with acute COVID-19. The increased levels of both sTM and Weibel-Palade body components (VWF, osteoprotegerin, and Angpt-2) correlated with COVID-19 severity. Incubation of COVID-19 plasma with ECs triggered enhanced VWF secretion and increased Angpt-2 expression, as well as significantly enhanced in vitro EC tube formation and angiogenesis.

Conclusion

We propose that acute SARS-CoV-2 infection leads to a complex and multifactorial EC activation, progressive loss of thrombomodulin, and increased Angpt-2 expression, which collectively serve to promote a local proangiogenic state.

Vaccine-induced thrombosis and thrombocytopenia (VITT) in Ireland: A review of cases and current practices

Since the beginning of the Severe Acute Respiratory Syndrome Coronavirus-2 (SARS CoV-2) virus pandemic, several highly effective and safe vaccines have been produced at remarkable speed. Following global implementation of vaccination programmes, cases of thrombosis with thrombocytopenia following administration of adenoviral vector-based vaccines started being reported. In this review we discuss the known pathogenesis and epidemiology of so-called vaccine induced thrombocytopenia and thrombosis (VITT). We consider the available guidelines, diagnostic laboratory tests and management options for these patients. Finally, we discuss important unanswered questions and areas for future research in this novel pathoclinical entity.

Premature ovarian ageing following heterozygous loss of Senataxin

Premature loss of ovarian activity before 40 years of age is known as primary ovarian insufficiency (POI) and occurs in ∼1% of women. A more subtle decline in ovarian activity, known as premature ovarian ageing (POA), occurs in ∼10% of women. Despite the high prevalence of POA, very little is known regarding its genetic causation. Senataxin (SETX) is an RNA/DNA helicase involved in repair of oxidative stress-induced DNA damage. Homozygous mutation of SETX leads to the neurodegenerative disorder, ataxia oculomotor apraxia type 2 (AOA2). There have been reports of POI in AOA2 females suggesting a link between SETX and ovarian ageing. Here, we studied female mice lacking either one (Setx+/-) or both (Setx-/-) copies of SETX over a 12- to 14-month period. We find that DNA damage is increased in oocytes from 8-month-old Setx+/- and Setx-/- females compared with Setx+/+ oocytes leading to a marked reduction in all classes of ovarian follicles at least 4 months earlier than typically occurs in female mice. Furthermore, during a 12-month long mating trial, Setx+/- and Setx-/- females produced significantly fewer pups than Setx+/+ females from 7 months of age onwards. These data show that SETX is critical for preventing POA in mice, likely by preserving DNA integrity in oocytes. Intriguingly, heterozygous Setx loss causes an equally severe impact on ovarian ageing as homozygous Setx loss. Because heterozygous SETX disruption is less likely to produce systemic effects, SETX compromise could underpin some cases of insidious POA.

Acquired Factor Xiii Deficiency: An Uncommon But Easily Missed Cause Of Severe Bleeding

Factor XIII (FXIII) is a plasma clotting protein involved in clot stabilization. Severe FXIII deficiency may present with severe, even fatal bleeding. Critically however, routine coagulation assays may be normal and only specific FXIII assays will detect the abnormality. Herein we discuss a case report of a patient with acquired FXIII deficiency in order to highlight the clinical challenges associated with establishing the diagnosis and discuss the treatment approach. A 70-year-old man presented with a gluteal haematoma despite no preceding personal history of bleeding. Extensive initial haemostatic investigations were normal until a specific FXIII assay showed a marked reduction in FXIII levels. With directed treatment, bleeding episodes ceased and remission was achieved. Clinical awareness of FXIII deficiency is important, so appropriate testing can be implemented in patients with unexplained bleeding diatheses, particularly those in whom bleeding responds poorly to standard replacement therapy.

Abstract P1-07-09: Serum activin A and outcomes in HR+ /HER2- metastatic breast cancer patients treated with everolimus: Results from BOLERO-2

Background: Everolimus (EVE) plus exemestane (EXE) doubled progression-free survival (PFS) while maintaining quality of life versus EXE alone in postmenopausal women with hormone receptor positive (HR+), HER2-negative metastatic breast cancer (mBC) (BOLERO-2 phase 3; NCT00863655). Pretreatment serum activin A was previously reported as a prognostic factor in first-line hormone therapy (letrozole vs tamoxifen) (Novartis P025) and anti-HER2 mBC (lapatinib vs trastzmab) (CCTG MA.31) trials. Here we investigate the prognostic and predictive ability of activin A in BOLERO-2.

Methods: Activin A levels were determined on pretreatment serum samples using ELISA. Cox-proportional hazards model was used to assess the efficacy of EVE in the activin A low and high subgroups (median cut-point), and the prognostic effect of activin A on PFS and overall survival (OS).

Results: Baseline activin A levels were determined in 513 patients (71% of 725 BOLERO-2 patients randomized 2:1 to EVE+EXE or EXE). Predictive and prognostic signals are shown in the table below

Predictive and prognostic signalsPredictive/PrognosticEnd-pointAct-ivin ATreatmentNEventsMedian PFSHR (95% CI); p valuepredictivePFSHEXE93832.5 (1.5-2.8)-predictivePFSHEVE+EXE1631325.4 (4.1-6.8)0.46 (0.34 - 0.60); <0.0001predictivePFSLEXE89774.2 (2.0 -5.4)-predictivePFSLEVE+EXE1681059.9 (8.1-12.5)0.38 (0.28 - 0.51); <0.0001predictiveOSHEXE936820.1 (13.8-22.6)-predictiveOSHEVE+EXE16312917.7 (15.7-22.3)1.04 (0.78 - 1.40); 0.78predictiveOSLEXE8939NA (34.7-NA)-predictiveOSLEVE+EXE1687241.4 (36.4-NA)1.02 (0.69 - 1.50); 0.93prognosticPFSH 2562154.1 (2.9-4.2)-prognosticPFSL 2571826.9 (6.7-8.5)0.54 (0.45 - 0.66); <0.0001prognosticOSH 25619718.0 (16.5-21.1)-prognosticOSL 25711142.3 (38.5-NA)0.34 (0.27 - 0.42); <0.0001

.

In multivariate analysis (including sensitivity to prior hormone therapy and visceral disease), activin A remained a significant independent prognostic factor for PFS and OS [HR 0.57 (0.46-0.69) and 0.34 (0.27-0.43), respectively].

Conclusions: Higher serum activin A was strongly associated with shorter PFS and OS in HR+/HER2- mBC patients. Everolimus was efficacious regardless of serum activin A level. These results are similar to our previous studies in phase 3 trials of letrozole-tamoxifen (Novartis P025), and HER2-targeted therapy, lapatinib vs trastuzmab (CCTG MA.31): pretreatment serum activin A was prognostic for outcome, but was not a predictive factor for treatment arm selection.

Citation Format: Ali SM, Chen D, Ali A, Krecko L, Leitzel K, Vasekar M, Nagabhairu V, Marks E, Polimera H, Richardson A, May M, He W, Patel P, Lavin M, Hofsess S, Sweetman R, Hortobagyi G, Baselga J, Lipton A. Serum activin A and outcomes in HR+ /HER2- metastatic breast cancer patients treated with everolimus: Results from BOLERO-2 [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P1-07-09.

Lenalidomide as a novel treatment for refractory acquired von Willebrand syndrome associated with monoclonal gammopathy

Essentials Treatment options are limited for refractory bleeding in acquired von Willebrand Syndrome (AVWS). Lenalidomide therapy was studied in two patients with AVWS due to monoclonal gammopathy (MG). Lenalidomide increased von Willebrand factor (VWF), lowered VWF clearance and resolved bleeding. Lenalidomide is a potential treatment option for refractory bleeding in AVWS secondary to MG.

SUMMARY

Background Acquired von Willebrand syndrome (AVWS) is associated with lymphoproliferative disorders, including monoclonal gammopathy (MG) of undetermined significance (MGUS) and multiple myeloma. Patients commonly present with significant bleeding complications that are difficult to manage, owing to a markedly reduced von Willebrand factor (VWF) half-life. Objectives To investigate the use of the immunomodulatory drug lenalidomide in two patients with severe refractory bleeding caused by AVWS associated with MGs. Results In both patients, lenalidomide treatment resulted in significant clinical improvement, and marked increases in plasma VWF antigen (VWF:Ag) and VWF ristocetin cofactor levels. This normalization in plasma VWF levels was sustained for > 2 years in both patients. Furthermore, in one patient, plasma VWF levels remain normal for at least 14 months following discontinuation of lenalidomide treatment. To investigate the molecular mechanisms underlying these observations, VWF propeptide (VWFpp)/VWF:Ag ratios were analyzed to assess VWF clearance. At enrolment, plasma VWFpp/VWF:Ag ratios were significantly elevated in both patients. Importantly, lenalidomide treatment resulted in normalization of VWFpp/VWF:Ag ratios in both patients. These novel data suggest that lenalidomide functions to attenuate enhanced VWF clearance in AVWS. Interestingly, in a patient with MGUS, lenalidomide treatment was associated with a significant increase in plasma VWF levels, despite no major change in paraprotein level. Conclusions Collectively, our findings suggest that lenalidomide constitutes a novel therapeutic option for the management of AVWS associated with MG. The biological mechanism(s) through which lenalidomide causes a sustained increase in plasma VWF levels in AVWS independently of paraprotein level requires further study, but is in part modulated through inhibition of enhanced VWF clearance.

von Willebrand factor arginine 1205 substitution results in accelerated macrophage-dependent clearance in vivo

BACKGROUND

Enhanced von Willebrand factor (VWF) clearance is important in the etiology of type 1 and type 2 von Willebrand disease (VWD). More than 20 different VWF point mutations have already been reported in patients with enhanced clearance. These include the VWD-Vicenza variant, which is characterized by an Arg1205His substitution in the VWF D3 domain. Critically, however, the molecular mechanisms through which single amino acid substitutions in VWF result in enhanced clearance of this complex multimeric glycoprotein have not been defined.

OBJECTIVES

In this study, we have investigated the biological basis underlying the enhanced clearance of the VWF-R1205H variant.

METHODS

Using VWF(-/-) mice, in vivo clearance rates were determined for a series of full-length and truncated recombinant VWF variants. In addition, the role of macrophages in modulating enhanced VWD-Vicenza clearance was investigated using clodronate liposome administration.

RESULTS

Our findings demonstrate that substitutions of R1205 with histidine, cysteine or serine all result in markedly reduced survival of full-length recombinant VWF. Importantly, D'A3 fragments containing these same R1205 substitutions also demonstrated significantly enhanced clearance. In contrast to the reduced in vivo survival observed with R1205H, clearance of R1204H was not enhanced. Recent studies have demonstrated that hepatic and splenic macrophages play key roles in regulating VWF clearance. Importantly, macrophage-depletion also served to markedly attenuate the enhanced clearance phenotypes associated with VWF-R1205H, VWF-R1205S and VWF-R1205C.

CONCLUSIONS

Collectively, these novel findings demonstrate a specific and critical role for the R1205 residue in modulating macrophage-mediated clearance of VWF in vivo.

A late methanogen origin for molybdenum-dependent nitrogenase

Mounting evidence indicates the presence of a near complete biological nitrogen cycle in redox-stratified oceans during the late Archean to early Proterozoic (c. 2.5-2.0 Ga). It has been suggested that the iron (Fe)- or vanadium (V)-dependent nitrogenase rather than molybdenum (Mo)-dependent form was responsible for dinitrogen fixation during this time because oceans were depleted in Mo and rich in Fe. We evaluated this hypothesis by examining the phylogenetic relationships of proteins that are required for the biosynthesis of the active site cofactor of Mo-nitrogenase in relation to structural proteins required for Fe-, V- and Mo-nitrogenase. The results are highly suggestive that among extant nitrogen-fixing organisms for which genomic information exists, Mo-nitrogenase is unlikely to have been associated with the Last Universal Common Ancestor. Rather, the origin of Mo-nitrogenase can be traced to an ancestor of the anaerobic and hydrogenotrophic methanogens with acquisition in the bacterial domain via lateral gene transfer involving an anaerobic member of the Firmicutes. A comparison of substitution rates estimated for proteins required for the biosynthesis of the nitrogenase active site cofactor and for a set of paralogous proteins required for the biosynthesis of bacteriochlorophyll suggests that Nif emerged from a nitrogenase-like ancestor approximately 1.5-2.2 Ga. An origin and ensuing proliferation of Mo-nitrogenase under anoxic conditions would likely have occurred in an environment where anaerobic methanogens and Firmicutes coexisted and where Mo was at least episodically available, such as in a redox-stratified Proterozoic ocean basin.

Sensation seeking and collegiate vulnerability to internet dependence

Past research on Internet dependence has suggested that those who are Internet dependent spend more time on-line, use chat rooms more frequently, play MUDs more often, and web surf more than nondependent Internet users, but few studies have examined how personality characteristics interact with Internet dependence. This study investigates how Internet usage, preferences, attitudes toward the Internet, and Internet behaviors are correlated with sensation seeking. It was predicted that participants who were higher in Internet usage and Internet behaviors would be higher in sensation seeking. Results indicated that Internet dependents tended to spend more time online, use E-mail, surf the web, use chat rooms, use MUDs, and visit cybersex sites more often than nondependent Internet users. However, dependents scored significantly lower on sensation seeking, thrill and adventure seeking, and excitement seeking than nondependent Internet users. It was concluded that dependents interact with the internet using a motivation scheme dissimilar to the physical thrill and excitement that typically characterize sensation seeking archetypes.

Functional and computational assessment of missense variants in the ataxia-telangiectasia mutated (ATM) gene: mutations with increased cancer risk

The functional consequences of missense variants are often difficult to predict. This becomes especially relevant when DNA sequence changes are used to determine a diagnosis or prognosis. To analyze the consequences of 12 missense variants in patients with mild forms of ataxia-telangiectasia (A-T), we employed site-directed mutagenesis of ataxia-telangiectasia mutated (ATM) cDNA followed by stable transfections into a single A-T cell line to isolate the effects of each allele on the cellular phenotype. After induction of the transfected cells with CdCl2, we monitored for successful ATM transcription and subsequently assessed: 1) intracellular ATM protein levels; 2) ionizing radiation (IR)-induced ATM kinase activity; and 3) cellular radiosensitivity. We then calculated SIFT and PolyPhen scores for the missense changes. Nine variants produced little or no correction of the A-T cellular phenotype and were interpreted to be ATM mutations; SIFT/PolyPhen scores supported this. Three variants corrected the cellular phenotype, suggesting that they represented benign variants or polymorphisms. SIFT and PolyPhen scores supported the functional analyses for one of these variants (c.1709T>C); the other two were predicted to be "not tolerated" (c.6188G>A and c.6325T>G) and were classified as "operationally neutral." Genotype/phenotype relationships were compared: three deleterious missense variants were associated with an increased risk of cancer (c.6679C>T, c.7271T>G, and c.8494C>T). In situ mutagenesis represents an effective experimental approach for distinguishing deleterious missense mutations from benign or operationally neutral missense variants.

Percentage of canals filled in apical cross sections - anin vitrostudy of seven obturation techniques

AIM

To compare the apical density of several obturation techniques when used in palatal roots of extracted maxillary molars.

METHODOLOGY

Seventy extracted molars were randomly divided into seven groups with 10 teeth each. The palatal root canals were instrumented to size 60 MAF, coated with Kerr's Pulp Canal Sealer, and obturated using one of seven techniques. The palatal roots were separated from the crowns, decalcified, and sectioned horizontally at 2 and 4 mm from the apex. The cross-sections were photographed through a microscope, the photos were analysed, and the amount of area in the canal that was obturated with gutta-percha was measured. The means for the 20 sections per group were calculated and the means were compared using mixed analysis of variance test.

RESULTS

Simplifill used in accordance with the manufacturer's directions and Thermafil had the greatest mean obturated area, but neither were statistically better than mechanical lateral or warm vertical compaction (WVC; Schilder Technique). Simplifill as recommended and Thermafil were statistically better than cold lateral (P = 0.0210 and 0.0433, respectively), WVC (continuous wave) (P = 0.0006 and 0.0015), and the modified Simplifill group (P = 0.0010 and 0.0012). In addition, mechanical lateral and WVC (Schilder) had statistically more obturated area than WVC (continuous wave) (P = 0.0054 and 0.0073) and modified Simplifill (P = 0.0015 and 0.0016). Cold lateral and WVC (continuous wave) had significantly more obturated area than modified Simplifill (P = 0.0040 and 0.0087).

CONCLUSIONS

Simplifill as recommended, Thermafil, mechanical lateral and WVC (Schilder) obturation techniques created more complete obturation using gutta-percha at the 2 and 4 mm levels than cold lateral, WVC (continuous wave), and Simplifill not used as directed.

The dalbergioid legumes (Fabaceae): delimitation of a pantropical monophyletic clade

A monophyletic pantropical group of papilionoid legumes, here referred to as the "dalbergioid" legumes, is circumscribed to include all genera previously referred to the tribes Aeschynomeneae and Adesmieae, the subtribe Bryinae of the Desmodieae, and tribe Dalbergieae except Andira, Hymenolobium, Vatairea, and Vataireopsis. This previously undetected group was discovered with phylogenetic analysis of DNA sequences from the chloroplast trnK (including matK) and trnL introns, and the nuclear ribosomal 5.8S and flanking internal transcribed spacers 1 and 2. All dalbergioids belong to one of three well-supported subclades, the Adesmia, Dalbergia, and Pterocarpus clades. The dalbergioid clade and its three main subclades are cryptic in the sense that they are genetically distinct but poorly, if at all, distinguished by nonmolecular data. Traditionally important taxonomic characters, such as arborescent habit, free stamens, and lomented pods, do not provide support for the major clades identified by the molecular analysis. Short shoots, glandular-based trichomes, bilabiate calyces, and aeschynomenoid root nodules, in contrast, are better indicators of relationship at this hierarchical level. The discovery of the dalbergioid clade prompted a re-analysis of root nodule structure and the subsequent finding that the aeschynomenoid root nodule is synapomorphic for the dalbergioids.

Clinical application of in vitro radiohypersensitivity testing

The cases of two patients who suffered severe late effects of radiotherapy are reported; each tested positive for elevated in vitro radiohypersensitivity (RHS) but negative for the ataxia-telangiectasia mutation. The first patient underwent surgery and postoperative radiotherapy for lung cancer and subsequently developed fatal myelopathy. The second patient underwent triple-modality therapy for cervical cancer and suffered highly symptomatic pelvic fibrosis. The value of the testing was that it increased the confidence in the diagnosis of radiation effects and enabled suitable treatment to proceed. An increasing role for clinical RHS testing is anticipated.

Phylogenetic systematics of the tribe Millettieae (Leguminosae) based on chloroplast trnK/matK sequences and its implications for evolutionary patterns in Papilionoideae

Phylogenetic relationships in the tribe Millettieae and allies in the subfamily Papilionoideae (Leguminosae) were reconstructed from chloroplast trnK/matK sequences. Sixty-two accessions representing 57 traditionally recognized genera of Papilionoideae were sampled, including 27 samples from Millettieae. Phylogenies were constructed using maximum parsimony and are well resolved and supported by high bootstrap values. A well-supported "core Millettieae" clade is recognized, comprising the four large genera Millettia, Lonchocarpus, Derris, and Tephrosia. Several other small genera of Millettieae are not in the core Millettieae clade. Platycyamus is grouped with Phaseoleae (in part). Ostryocarpus, Austrosteenisia, and Dalbergiella are neither in the core Millettieae or Phaseoleae clade. These taxa, along with core Millettieae and Phaseoleae, form a monophyletic sister group to Indigofereae. Cyclolobium and Poecilanthe are close to Brongniartieae. Callerya and Wisteria belong to a large clade that includes all the legumes that lack the inverted repeat in their chloroplast genome, which confirms previous rbcL and phytochrome gene family phylogenies. The evolutionary history of four characters was examined in Millettieae and allies: the presence of canavanine, inflorescence types, the dehiscence of pods, and the presence of winged pods. trnK/matK sequence analysis suggests that the presence of a pseudoraceme or pseudopanicle and the accumulation of nonprotein amino acids are phylogenetically informative for Millettieae and allies with only a few exceptions.

Immunoblot analysis for laboratory diagnosis of ataxia-telangiectasia: use of Epstein-Barr virus-transformed or phytohemagglutinin-stimulated lymphoblasts for detection of ATM protein

Ataxia-telangiectasia (A-T) is a genetic disorder characterized by a progressive ataxia, immunodeficiency, neurological abnormalities, hypersensitivity to ionizing radiation, and predisposition to cancer. The gene responsible for A-T (ATM) has been cloned and shown to code for a 350 kDa polypeptide containing 3,056 amino acid residues. Detection of ATM mutations for laboratory diagnosis of A-T is laborious and not practical, unless there are common mutations in a population. We describe here immunoblot analysis for the detection of ATM in seven Japanese A-T patients from five families and in controls using ATM3BA antibody. ATM protein was routinely and clearly detected in Epstein-Barr virus (EBV)-transformed or phytohemagglutinin (PHA)-stimulated lymphoblasts from controls. However, it could not be detected consistently in unstimulated peripheral blood mononuclear cells (PBMCs) from controls. We also detected ATM protein in control fibroblasts, but the background was relatively higher than in control lymphoblasts. ATM protein was not detected or dramatically decreased in EBV-transformed lymphoblasts from all seven patients tested and in fibroblasts from one patient. Immunoblot analysis using EBV-transformed or PHA-stimulated lymphoblasts represents a useful approach for laboratory diagnosis for A-T. The latter is especially preferable since it takes only 3 days to obtain sufficient cells for analysis.