Gastric stem cells promote inflammation and gland remodeling in response to Helicobacter pylori via Rspo3-Lgr4 axis.

Helicobacter pylori is a pathogen that colonizes the stomach and causes chronic gastritis. Helicobacter pylori can colonize deep inside gastric glands, triggering increased R-spondin 3 (Rspo3) signaling. This causes an expansion of the "gland base module," which consists of self-renewing stem cells and antimicrobial secretory cells and results in gland hyperplasia. The contribution of Rspo3 receptors Lgr4 and Lgr5 is not well explored. Here, we identified that Lgr4 regulates Lgr5 expression and is required for H. pylori-induced hyperplasia and inflammation, while Lgr5 alone is not. Using conditional knockout mice, we reveal that R-spondin signaling via Lgr4 drives proliferation of stem cells and also induces NF-κB activity in the proliferative stem cells. Upon exposure to H. pylori, the Lgr4-driven NF-κB activation is responsible for the expansion of the gland base module and simultaneously enables chemokine expression in stem cells, resulting in gland hyperplasia and neutrophil recruitment. This demonstrates a connection between R-spondin-Lgr and NF-κB signaling that links epithelial stem cell behavior and inflammatory responses to gland-invading H. pylori.

TRIM28 inactivation in epithelial nephroblastoma is frequent and often associated with predisposing TRIM28 germline variants.

Wilms tumors (WTs) are histologically diverse childhood cancers with variable contributions of blastema, stroma, and epithelia. A variety of cancer genes operate in WTs, including the tripartite-motif-containing-28 gene (TRIM28). Case reports and small case series suggest that TRIM28 mutations are associated with epithelial morphology and WT predisposition. Here, we systematically investigated the prevalence of TRIM28 inactivation and predisposing mutations in a cohort of 126 WTs with >2/3 epithelial cells, spanning 20 years of biobanking in the German SIOP93-01/GPOH and SIOP2001/GPOH studies. Overall, 44.4% (56/126) cases exhibited loss of TRIM28 by immunohistochemical staining. Of these, 48 could be further analyzed molecularly, revealing TRIM28 sequence variants in each case - either homozygous (~2/3) or heterozygous with epigenetic silencing of the second allele (~1/3). The majority (80%) of the mutations resulted in premature stops and frameshifts. In addition, we detected missense mutations and small deletions predicted to destabilize the protein through interference with folding of key structural elements such as the zinc-binding clusters of the RING, B-box-2, and PHD domains or the central coiled-coil region. TRIM28-mutant tumors otherwise lacked WT-typical IGF2 alterations or driver events, except for rare TP53 progression events that occurred with expected frequency. Expression profiling identified TRIM28-mutant tumors as a homogeneous subset of epithelial WTs that mostly present with stage I disease. There was a high prevalence of perilobar nephrogenic rests, putative precursor lesions, that carried the same biallelic TRIM28 alterations in 7/7 cases tested. Importantly, 46% of the TRIM28 mutations were present in blood cells or normal kidney tissue, suggesting germline events or somatic mosaicism, partly supported by family history. Given the high prevalence of predisposing variants in TRIM28-driven WT, we suggest that immunohistochemical testing of TRIM28 be integrated into diagnostic practice as the management of WT in predisposed children differs from that with sporadic tumors. © 2023 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Unraveling the Mechanisms of Efficient Phosphorus Utilization in Popcorn (Zea mays L. var. everta): Insights from Proteomic and Metabolite Analysis.

The expansion of agriculture and the need for sustainable practices drives breeders to develop plant varieties better adapted to abiotic stress such as nutrient deficiency, which negatively impacts yields. Phosphorus (P) is crucial for photosynthesis and plant growth, but its availability in the soil is often limited, hampering crop development. In this study, we examined the response of two popcorn inbred lines, L80 and P7, which have been characterized previously as P-use inefficient and P-use efficient, respectively, under low (stress) and high P (control) availability. Physiological measurements, proteomic analysis, and metabolite assays were performed to unravel the physiological and molecular responses associated with the efficient use of P in popcorn. We observed significant differences in protein abundances in response to the P supply between the two inbred lines. A total of 421 differentially expressed proteins (DEPs) were observed in L80 and 436 DEPs in P7. These proteins were involved in photosynthesis, protein biosynthesis, biosynthesis of secondary metabolites, and energy metabolism. In addition, flavonoids accumulated in higher abundance in P7. Our results help us understand the major components of P utilization in popcorn, providing new insights for popcorn molecular breeding programs.

Phase 1/dose expansion trial of brentuximab vedotin and lenalidomide in relapsed or refractory diffuse large B-cell lymphoma.

New therapies are needed for patients with relapsed/refractory (rel/ref) diffuse large B-cell lymphoma (DLBCL) who do not benefit from or are ineligible for stem cell transplant and chimeric antigen receptor therapy. The CD30-targeted, antibody-drug conjugate brentuximab vedotin (BV) and the immunomodulator lenalidomide (Len) have demonstrated promising activity as single agents in this population. We report the results of a phase 1/dose expansion trial evaluating the combination of BV/Len in rel/ref DLBCL. Thirty-seven patients received BV every 21 days, with Len administered continuously for a maximum of 16 cycles. The maximum tolerated dose of the combination was 1.2 mg/kg BV with 20 mg/d Len. BV/Len was well tolerated with a toxicity profile consistent with their use as single agents. Most patients required granulocyte colony-stimulating factor support because of neutropenia. The overall response rate was 57% (95% CI, 39.6-72.5), complete response rate, 35% (95% CI, 20.7-52.6); median duration of response, 13.1 months; median progression-free survival, 10.2 months (95% CI, 5.5-13.7); and median overall survival, 14.3 months (95% CI, 10.2-35.6). Response rates were highest in patients with CD30+ DLBCL (73%), but they did not differ according to cell of origin (P = .96). NK cell expansion and phenotypic changes in CD8+ T-cell subsets in nonresponders were identified by mass cytometry. BV/Len represents a potential treatment option for patients with rel/ref DLBCL. This combination is being further explored in a phase 3 study (registered on https://clinicaltrials.org as NCT04404283). This trial was registered on https://clinicaltrials.gov as NCT02086604.

Firearm Injuries in Young Children: Surgical Resource Utilization and Implications for Prevention.

INTRODUCTION: Pediatric firearm injury prevention research in younger age groups is limited. This study evaluated a large multicenter cohort of younger children with firearm injuries, focusing on injury patterns and surgical resource utilization. METHODS: Children ≤15 y old sustaining firearm injuries between 2016 and 2021 and treated at 10 pediatric trauma centers in Florida were included. Individual cases were reviewed for demographics, shooting details, injury patterns, resource utilization, and outcomes. Patients were grouped by age into preschool (0-5 y), elementary school (6-10 y), middle school (11-13 y), and early high school (14-15 y). Multivariable logistic regression was used to identify predictors of death and critical resource utilization. RESULTS: A total of 489 children (80 preschool, 76 elementary school, 92 middle school, and 241 early high school) met inclusion criteria. Demographics, injury patterns, and resource utilization were similar across age groups. Assault and self-harm increased with age. Self-harm was implicated in 5% of cases but accounted for 18% of deaths. Hand surgery (i.e., below-elbow) procedures were common at 8%. Overall mortality was 10%, but markedly higher for self-harm injuries (47%). On multivariable regression, age and demographics were not predictive of death or critical resource utilization, but self-harm intent was a strong independent risk factor for both. CONCLUSIONS: This study suggests that given the age distribution and disproportionately high impact of self-harm injuries, behavioral health resources should be available to children at the middle school level or earlier. Hand surgery may represent an overlooked but frequently utilized resource to mitigate injury impact and optimize long-term function.

Clinical, biological, and genetic features in an afibrinogenemia patient series in Algeria.

INTRODUCTION: The incidence of afibrinogenemia had not been previously reported in Algeria. Afibrinogenemia patients are prone to both haemorrhagic and thrombotic complications. Predictive markers of thrombosis in afibrinogenemia patients are not existent. AIMS AND METHODS: Clinical and biological data from 46 afibrinogenemia patients are reported. Biological investigations included routine tests, genetics analysis and thrombin generation. RESULTS: FGA mutations (four novel and four previously described) and FGB mutations (seven mutations; five novels) were homozygous in all but one family as a result of 28 consanguineous marriages out of 30 discrete families. Incidence of afibrinogenemia in Algeria is at least 3 per million births. Umbilical bleeding was reported in 39/46 cases and was the main discovery circumstance. We also report post trauma or post-surgery (3/46) bleeding and spontaneous deep vein thrombosis (DVT) in adulthood (1/46), as discovery circumstances. The median age (10.5-year-old) of the population reported here explains why there are few hemarthrosis and obstetrical or gynaecological complications in this series. Thrombotic events were reported in seven patients (four spontaneous). Endogenous Thrombin Potential was significantly increased in thrombosis-prone patients compared to afibrinogenemic patients with and without personal or familial history (1118 vs. 744 and 817 nM IIa × min, respectively). CONCLUSION: The incidence of afibrinogenemia in Algeria is the consequence of consanguineous marriage in families carrying private mutations. The thrombin generation test (TGT) could identify, among afibrinogenemic patients, those presenting a thrombotic risk.

Comparison of fatigue, cognitive dysfunction and psychological disorders in post-COVID patients and patients after sepsis: is there a specific constellation?

BACKGROUND: Sequelae of COVID-19 can be severe and longlasting. We compared frequencies of fatigue, depression and cognitive dysfunction in survivors of SARS-CoV-2-infection and sepsis. METHODS: We performed a prospective cohort study of 355 symptomatic post-COVID patients who visited our out-patient clinic for post-COVID-19 care. We compared them with 272 symptomatic patients from the Mid-German Sepsis Cohort, which investigates the long-term courses of sepsis survivors. Possible predictors for frequent clinical findings (fatigue, signs of depression, cognitive dysfunction) in post-COVID were investigated with multivariable logistic regression. RESULTS: Median age of the post-COVID patients was 51 years (range 17-86), 60.0% were female, and 31.8% required hospitalization during acute COVID-19. In the post-COVID patients (median follow-up time: 163 days) and the post-sepsis patients (180 days), fatigue was found in 93.2% and 67.8%, signs of depression were found in 81.3% and 10.9%, and cognitive dysfunction was found in 23.5% and 21.3%, respectively. In post-COVID, we did not observe an association between fatigue or depression and the severity of acute COVID-19. In contrast, cognitive dysfunction was associated with hospitalization (out-patient versus in-patient) and more frequent in post-COVID patients treated on an ICU compared to the MSC patients. CONCLUSION: In post-COVID patients, fatigue and signs of depression are more common than in sepsis survivors, independent from the acute SARS-CoV-2-infection. In contrast, cognitive dysfunction is associated with hospitalization. Despite the differences in frequencies, owing to the similarity of post-COVID and post-sepsis sequelae, this knowledge may help in implementing follow-up approaches after SARS-CoV-2 infection.

Reversible Dioxygen Binding to Co(II) Complexes with Noninnocent Ligands.

A series of mononuclear Co(II) complexes with noninnocent (redox-active) ligands are prepared that exhibit metal-ligand cooperativity during the reversible binding of O2. The complexes have the general formula, [CoII(LS,N)(TpR2)] (R = Me, Ph), where LS,N is a bidentate o-aminothiophenolate and TpR2 is a hydrotris(pyrazol-1-yl)borate scorpionate with R-substituents at the 3- and 5-positions. Exposure to O2 at room temperature results in one-electron oxidation and deprotonation of LS,N. The oxidized derivatives possess substantial "singlet diradical" character arising from antiferromagnetic coupling between an iminothiosemiquinonate (ITSQ•-) ligand radical and a low-spin Co(II) ion. The [CoII(TpMe2)(X2ITSQ)] complexes, where X = H or tBu, coordinate O2 reversibly at reduced temperatures to provide Co/O2 adducts. The O2 binding reactions closely resemble those previously reported by our group (Kumar et al., J. Am. Chem. Soc. 2019,141, 10984-10987) for the related complexes [CoII(TpMe2)(tBu2SQ)] and [CoII(TpMe2)(tBu2ISQ)], where tBu2(I)SQ represents 4,6-di-tert-butyl-(2-imino)semiquinonate radicals. In each case, the oxygenation reaction proceeds via the addition of O2 to both the cobalt ion and the ligand radical, generating metallocyclic cobalt(III)-alkylperoxo structures. Thermodynamic measurements elucidate the relationship between O2 affinity and redox potentials of the (imino)(thio)semiquinonate radicals, as well as energetic differences between these reactions and conventional metal-based oxygenations. The results highlight the utility and versatility of noninnocent ligands in the design of O2-absorbing compounds.

Effects of Regional and General Anesthesia on the Therapeutic Outcome of Benign Thyroid Nodules Treated with High Intensity Focused Ultrasound (HIFU).

BACKGROUND: The study investigated whether anesthesia performed during high-intensity-focused-ultrasound treatment (HIFU) of benign thyroid nodules influenced the therapy outcome, based on volume reduction and the amount of energy delivered. METHODS: Thirty patients with benign thyroid nodules were treated with HIFU under general or regional anesthesia at two centers from 2014 to 2019. During HIFU, a therapeutic ultrasound probe, EchoPulse (Teraclion, Malakoff, France), heats the focus to 80-90 degrees Celsius. Nodal volumes were measured by ultrasound before and 3 months after therapy. For statistical analysis, the total population was divided into two groups according to the anesthesia performed. In a retrospective long-term multicenter study, volume reduction and the energy delivered were analyzed using the Wilcoxon signed-rank test and the Mann-Whitney test. RESULTS: At three months follow-up, the total study population had an average volume reduction of 39.26% (range 4.03-91.16%, p < 0.001, n = 30), the general anesthesia group of 47.46% (range 13.64-91.16%, p = 0.001, n = 15) and the regional anesthesia group of 31.06% (range 4.03-68.63%, p = 0.001, n = 15). Under regional anesthesia a median energy of 3.16 kJ/cm3 (range: 0.96 - 8.2 kJ/cm3) and under general anesthesia a median energy of 0.88 kJ/cm3 (range: 0.18 - 1.63 kJ/cm3) were delivered. All results were significant with p < 0.05. The complication rate was 6.67%. CONCLUSION: HIFU is an effective method to treat benign thyroid nodules. Comparing anesthesia methods, volume reduction is higher in patients treated under general anesthesia and less energy has to be delivered under general anesthesia. TRIAL REGISTRATION NUMBER: 2020-1728-evBO. AGENCY: Ethik-Kommission bei der Landesäztekammer Hessen.

Mental imagery in adolescent PTSD patients after child abuse: a comparison with matched healthy controls.

BACKGROUND: Intrusive mental imagery (MI) plays a crucial role in the maintenance of posttraumatic stress disorder (PTSD) in adults. Evidence on the characteristics of MI in adolescents suffering from PTSD is sparse. The aim of this study was to thoroughly assess MI in an adolescent sample suffering from PTSD after the experience of childhood sexual abuse and/or childhood physical abuse (CA). METHODS: Thirty-two adolescents with a primary diagnosis of PTSD after CA and 32 adolescents without any mental disorder and without a history of CA, matched for age and gender, completed questionnaires assessing the characteristics of negative and positive MI, as well as images of injury and death that lead to positive emotions (ID-images). RESULTS: The PTSD group reported significantly more frequent, more vivid, more distressing and more strongly autobiographically linked negative MI compared to the control group. Although positive MI was highly present in both groups (PTSD: 65.6%; controls: 71.9%), no significant differences emerged between the two groups regarding the distinct characteristics of positive MI. The frequency of the ID-images did not significantly differ between the two groups (PTSD: 21.9%; controls: 9.4%), although the ID-images were more vivid in the PTSD group. DISCUSSION: Negative MI appears to be crucial in adolescent PTSD, whilst positive MI are unexpectedly common in both the PTSD and the control group. The role of positive MI as well as that of ID-images remain unclear. Specific interventions for changing negative MI that are tailored to the developmental challenges in adolescents with PTSD should be developed. TRIAL REGISTRATION: Some of the PTSD patients in this study were also part of a randomized controlled trial on Developmentally adapted Cognitive Processing Therapy (D-CPT). This trial was registered at the German Clinical Trial Registry (GCTR), DRKS00004787 , 18 March 2013.

Use of Stratified Cascade Learning to predict hospitalization risk with only socioeconomic factors.

BACKGROUND AND OBJECTIVE: Published models predicting health related outcomes rely on clinical, claims and social determinants of health (SDH) data. Addressing the challenge of predicting with only SDH we developed a novel framework termed Stratified Cascade Learning (SCL) and used it for predicting the risk of hospitalization (ROH). MATERIALS AND METHODS: The variable set includes 27 SDH and "age" and "sex" for a cohort of diabetic patients. The SCL model uses three sub-models: SM1 (whole training set) stratifies training set into "predictable" and "unpredictable" subsets, SM2 (built on whole training set) classifies test set patients into "predictable" and "unpredictable", and SM3 (built on only the "predictable" subset) predicts the ROH for the patients classified as "predictable" by SM2. RESULTS: The SCL model does not improve either the AUC or the NPV of the basic classifier, but materially improves accuracy and specificity measures at the expense of lowering sensitivity for the "predictable" subset. Optimization of the risk thresholds of the sub-models does not noticeably change the AUC and NPV but further improves the accuracy and specificity at the expense of further lowering sensitivity. CONCLUSION: Since the SLC model yields low sensitivity it fails to predict high risk patients. But it yields high specificity that can be useful when the objective is to eliminate low-risk patients as candidates for further testing or treatment. The use of the SCL is not limited to healthcare, it can be applied to any predictive modeling problem when reliable predictions can only be made for a fraction of incoming data.

Frequency and level of self-efficacy predict the effectiveness of therapist- and self-guided exposure in obsessive compulsive disorder.

BACKGROUND: While exposure and response prevention (ERP) is the most effective treatment for obsessive compulsive disorder (OCD), less is known about the specific mechanisms underlying symptom change after ERP. AIMS: We tested the hypothesis that the frequency of self- and therapist-guided ERP related to the extent of symptom reduction and that this link is mediated by increased self-efficacy. METHOD: In a sample of 377 in-patients with a primary diagnosis of OCD receiving in-patient CBT, we assessed symptoms (YBOCS-SR) and self-efficacy (General Self-Efficacy Scale), before and after treatment, as well as the frequency of therapist- and self-guided ERP sessions. RESULTS: Patients with more therapist-guided ERP sessions during treatment showed more symptom reduction and the association of self-guided ERP on outcome was mediated by enhanced self-efficacy. CONCLUSIONS: These findings highlight the importance of both therapist- and self-guided ERP sessions and suggest that therapists should conduct a sufficient number of ERP sessions to optimise treatment.

The Impact of Pediatric Surgical Specialty Meetings: A 5-year Analysis of Presented Abstracts.

BACKGROUND: Abstracts presented at the American Academy of Pediatrics Section on Surgery (AAP) and American Pediatric Surgical Association (APSA) meetings can be taken as a reasonable representation of academic activity in pediatric surgery. We sought to assess ongoing trends in pediatric surgical research by analyzing the scientific content of each association's yearly meeting. METHODS: Abstracts presented at AAP and APSA between 2009 and 2013 were identified from the final printed programs (n = 910). Video abstracts (n = 34) were excluded. Collected data included title, authors, classification (basic science/clinical), presentation type (podium/poster), and topic. Publication as a journal article was determined using the abstract title/authors in a PubMed search. Journal impact factors were recorded for each journal and a composite impact factor (CIF) was calculated by dividing the sum of impact factors by the published articles per meeting. RESULTS: Number of abstracts presented, percentage published, abstract classifications, and presentation type remained consistent over the study period. The AAP meetings accepted a higher percentage of clinical abstracts: AAP 72.3 ± 3.4% versus APSA 65.9 ± 1.3%. The five most popular topics at both meetings were oncology, congenital diaphragmatic hernia, necrotizing enterocolitis, trauma, and appendicitis. The publication rate for clinical and basic science abstracts did not vary significantly over the study period, whereas CIFs were higher for basic science publications nearly every year. The percentage of podium abstracts published was significantly greater than poster abstracts, but no statistical difference in CIF was seen between podium- and poster-associated publications. CONCLUSIONS: Abstracts accepted and presented at the two major pediatric surgical specialty meetings more commonly involve clinical studies with a trend away from basic science. Despite this, basic science abstracts tended to be published in higher impact journals. This study attempts to quantify the quality of pediatric surgical research and serves as a baseline for future comparison.

Spectroscopic and Computational Comparisons of Thiolate-Ligated Ferric Nonheme Complexes to Cysteine Dioxygenase: Second-Sphere Effects on Substrate (Analogue) Positioning.

Parallel spectroscopic and computational studies of iron(III) cysteine dioxygenase (CDO) and synthetic models are presented. The synthetic complexes utilize the ligand tris(4,5-diphenyl-1-methylimidazol-2-yl)phosphine (Ph2TIP), which mimics the facial three-histidine triad of CDO and other thiol dioxygenases. In addition to the previously reported [FeII(CysOEt)(Ph2TIP)]BPh4 (1; CysOEt is the ethyl ester of anionic l-cysteine), the formation and crystallographic characterization of [FeII(2-MTS)(Ph2TIP)]BPh4 (2) is reported, where the methyl 2-thiosalicylate anion (2-MTS) resembles the substrate of 3-mercaptopropionate dioxygenase (MDO). One-electron chemical oxidation of 1 and 2 yields ferric species that bind cyanide and azide anions, which have been used as spectroscopic probes of O2 binding in prior studies of FeIII-CDO. The six-coordinate FeIII-CN and FeIII-N3 adducts are examined with UV-vis absorption, electron paramagnetic resonance (EPR), and resonance Raman (rRaman) spectroscopies. In addition, UV-vis and rRaman studies of cysteine- and cyanide-bound FeIII-CDO are reported for both the wild-type (WT) enzyme and C93G variant, which lacks the Cys-Tyr cross-link that is present in the second coordination sphere of the WT active site. Density functional theory (DFT) and ab initio calculations are employed to provide geometric and electronic structure descriptions of the synthetic and enzymatic FeIII adducts. In particular, it is shown that the complete active space self-consistent field (CASSCF) method, in tandem with n-electron valence state second-order perturbation theory (NEVPT2), is capable of elucidating the structural basis of subtle shifts in EPR g values for low-spin FeIII species.

The bonobo genome compared with the chimpanzee and human genomes.

Two African apes are the closest living relatives of humans: the chimpanzee (Pan troglodytes) and the bonobo (Pan paniscus). Although they are similar in many respects, bonobos and chimpanzees differ strikingly in key social and sexual behaviours, and for some of these traits they show more similarity with humans than with each other. Here we report the sequencing and assembly of the bonobo genome to study its evolutionary relationship with the chimpanzee and human genomes. We find that more than three per cent of the human genome is more closely related to either the bonobo or the chimpanzee genome than these are to each other. These regions allow various aspects of the ancestry of the two ape species to be reconstructed. In addition, many of the regions that overlap genes may eventually help us understand the genetic basis of phenotypes that humans share with one of the two apes to the exclusion of the other.

The effect of spironolactone on calcineurin inhibitor induced nephrotoxicity: a multicenter randomized, double-blind, clinical trial (the SPIREN trial).

BACKGROUND: Calcineurin inhibitor induced nephrotoxicity contributes to late allograft failure in kidney transplant patients. Evidence points towards aldosterone to play a role in the development of fibrosis in multiple organs. Animal studies have indicated a beneficial effect of mineralocorticoid receptor antagonists preventing calcineurin inhibitor induced nephrotoxicity. Only few studies have explored this effect in humans. The objective of this study is to evaluate the effect of spironolactone on glomerular filtration rate and fibrosis in kidney transplant patients. METHOD: Prospective, double-blind, randomized, clinical trial including 170 prevalent kidney transplant patients. Patients are randomized to spironolactone 25-50 mg/day or placebo for three years. Primary outcome is glomerular filtration rate evaluated by chrome-EDTA clearance. Secondary outcomes are 24-h protein excretion, amount of interstitial fibrosis in renal allograft biopsies, and cardiovascular events. As an exploratory outcome, we aim to identify markers of fibrosis in blood and urine. DISCUSSION: Long term allograft survival remains a key issue in renal transplantation, partly due to calcineurin inhibitor induced nephrotoxicity. Evidence from animal- and small human studies indicate a beneficial effect of mineralocorticoid receptor antagonism on renal function and fibrosis. This study aims to test this hypothesis in a sufficiently powered randomized clinical trial. Results might influence the future management of long term allograft survival in renal transplantation. TRIAL REGISTRATION: ClinicalTrials.gov identifier (05/17/2012): NCT01602861 . EudraCT number (05/31/2011): 2011-002243-98.

Oxygen activation by mononuclear Mn, Co, and Ni centers in biology and synthetic complexes.

The active sites of metalloenzymes that catalyze O2-dependent reactions generally contain iron or copper ions. However, several enzymes are capable of activating O2 at manganese or nickel centers instead, and a handful of dioxygenases exhibit activity when substituted with cobalt. This minireview summarizes the catalytic properties of oxygenases and oxidases with mononuclear Mn, Co, or Ni active sites, including oxalate-degrading oxidases, catechol dioxygenases, and quercetin dioxygenase. In addition, recent developments in the O2 reactivity of synthetic Mn, Co, or Ni complexes are described, with an emphasis on the nature of reactive intermediates featuring superoxo-, peroxo-, or oxo-ligands. Collectively, the biochemical and synthetic studies discussed herein reveal the possibilities and limitations of O2 activation at these three "overlooked" metals.

Development of field-applicable tests for rapid and sensitive detection of Candidatus Phytoplasma oryzae.

Napier grass Stunt Disease (NSD) is a severe disease of Napier grass (Pennisetum purpureum) in Eastern Africa, caused by the leafhopper-transmitted bacterium Candidatus Phytoplasma oryzae. The pathogen severely impairs the growth of Napier grass, the major fodder for dairy cattle in Eastern Africa. NSD is associated with biomass losses of up to 70% of infected plants. Diagnosis of NSD is done by nested PCR targeting the phytoplasma DNA, which is difficult to perform in developing countries with little infrastructure. We report the development of an easy to use, rapid, sensitive and specific molecular assay for field diagnosis of NSD. The procedure is based on recombinase polymerase amplification and targets the imp gene encoding a pathogen-specific immunodominant membrane protein. Therefore we followed a two-step process. First we developed an isothermal DNA amplification method for real time fluorescence application and then transferred this assay to a lateral flow format. The limit of detection for both procedures was estimated to be 10 organisms. We simplified the template preparation procedure by using freshly squeezed phloem sap from Napier grass. Additionally, we developed a laboratory serological assay with the potential to be converted to a lateral flow assay. Two murine monoclonal antibodies with high affinity and specificity to the immunodominant membrane protein IMP of Candidatus Phytoplasma oryzae were generated. Both antibodies specifically reacted with the denatured or native 17 kDa IMP protein. In dot blot experiments of extracts from infected plant, phytoplasmas were detected in as little as 12,5 µg of fresh plant material.

Significant differentiation in the apolipoprotein(a)/lipoprotein(a) trait between chimpanzees from Western and Central Africa.

Elevated Lipoprotein(a) (Lp(a)) plasma concentrations are a risk factor for cardiovascular disease in humans, largely controlled by the LPA gene encoding apolipoprotein(a) (apo(a)). Lp(a) is composed of low-density lipoprotein (LDL) and apo(a) and restricted to Catarrhini. A variable number of kringle IV (KIV) domains in LPA lead to a size polymorphism of apo(a) that is inversely correlated with Lp(a) concentrations. Smaller apo(a) isoforms and higher Lp(a) levels in central chimpanzees (Pan troglodytes troglodytes [PTT]) compared to humans from Europe had been reported. We studied apo(a) isoforms and Lp(a) concentrations in 75 western (Pan troglodytes verus [PTV]) and 112 central chimpanzees, and 12 bonobos (Pan paniscus [PPA]), all wild born and living in sanctuaries in Sierra Leone, Republic of the Congo, and DR Congo, respectively, and 116 humans from Gabon. Lp(a) levels were severalfold higher in western than in central chimpanzees (181.0 ± 6.7 mg/dl vs. 56.5 ± 4.3 mg/dl), whereas bonobos showed intermediate levels (134.8 ± 33.4 mg/dl). Apo(a) isoform sizes differed significantly between subspecies (means 20.9 ± 2.2, 22.9 ± 4.4, and 23.8 ± 3.8 KIV repeats in PTV, PTT, and PPA, respectively). However, far higher isoform-associated Lp(a) concentrations for all isoform sizes in western chimpanzees offered the main explanation for the higher overall Lp(a) levels in this subspecies. Human Lp(a) concentrations (mean 47.9 ± 2.8 mg/dl) were similar to those in central chimpanzees despite larger isoforms (mean 27.1 ± 4.9 KIV). Lp(a) and LDL, apoB-100, and total cholesterol levels only correlated in PTV. This remarkable differentiation between chimpanzees from different African habitats and the trait's similarity in humans and chimpanzees from Central Africa poses the question of a possible impact of an environmental factor that has shaped the genetic architecture of LPA. Overall, studies on the cholesterol-containing particles of Lp(a) and LDL in chimpanzees should consider differentiation between subspecies.