Tandem manganese catalysis for the chemo-, regio-, and stereoselective hydroboration of terminal alkynes: in situ precatalyst activation as a key to enhanced chemoselectivity.

The manganese(ii) complex [Mn(iPrPNP)Cl2] (iPrPNP = 2,6-bis(diisopropylphosphinomethyl)pyridine) was found to catalyze the stereo- and regioselective hydroboration of terminal alkynes employing HBPin (pinacolborane). In the absence of in situ activators, mixtures of alkynylboronate and E-alkenylboronate esters were formed, whereas when NaHBEt3 was employed as the in situ activator, E-alkenylboronate esters were exclusively accessed. Mechanistic studies revealed a tandem C-H borylation/semihydrogenation pathway accounting for the formation of the products. Stoichiometric reactions hint toward reaction of a Mn-H active species with the terminal alkyne as the catalyst entry pathway to the cycle, whereas reaction with HBPin led to catalyst deactivation.

Orange surface waveguide laser in Pr:LiYF4 produced by a femtosecond laser writing.

Depressed-cladding surface channel waveguides were inscribed in a 0.5 at.% Pr:LiYF4 crystal by femtosecond Direct Laser Writing. The waveguides consisted of a half-ring cladding (inner diameter: 17 µm) and side structures ("ears") improving the mode confinement. The waveguide propagation loss was as low as 0.14 ± 0.05 dB/cm. The orange waveguide laser operating in the fundamental mode delivered 274 mW at 604.3 nm with 28.4% slope efficiency, a laser threshold of only 29 mW and linear polarization (π), representing record-high performance for orange Pr waveguide lasers.

Structures and mechanisms of tRNA methylation by METTL1-WDR4.

Specific, regulated modification of RNAs is important for proper gene expression1,2. tRNAs are rich with various chemical modifications that affect their stability and function3,4. 7-Methylguanosine (m7G) at tRNA position 46 is a conserved modification that modulates steady-state tRNA levels to affect cell growth5,6. The METTL1-WDR4 complex generates m7G46 in humans, and dysregulation of METTL1-WDR4 has been linked to brain malformation and multiple cancers7-22. Here we show how METTL1 and WDR4 cooperate to recognize RNA substrates and catalyse methylation. A crystal structure of METTL1-WDR4 and cryo-electron microscopy structures of METTL1-WDR4-tRNA show that the composite protein surface recognizes the tRNA elbow through shape complementarity. The cryo-electron microscopy structures of METTL1-WDR4-tRNA with S-adenosylmethionine or S-adenosylhomocysteine along with METTL1 crystal structures provide additional insights into the catalytic mechanism by revealing the active site in multiple states. The METTL1 N terminus couples cofactor binding with conformational changes in the tRNA, the catalytic loop and the WDR4 C terminus, acting as the switch to activate m7G methylation. Thus, our structural models explain how post-translational modifications of the METTL1 N terminus can regulate methylation. Together, our work elucidates the core and regulatory mechanisms underlying m7G modification by METTL1, providing the framework to understand its contribution to biology and disease.

Role of Oxidative Stress and Lipid Peroxidation in the Pathophysiology of NAFLD.

Non-alcoholic fatty liver disease (NAFLD) is characterised by an excess of hepatic fat that can progress to steatohepatitis, fibrosis, cirrhosis and hepatocarcinoma. The imbalance between lipid uptake/lipogenesis and lipid oxidation/secretion in the liver is a major feature of NAFLD. Given the lack of a non-invasive and reliable methods for the diagnosis of non-alcoholic steatohepatitis (NASH), it is important to find serum markers that are capable of discriminating or defining patients with this stage of NASH. Blood samples were obtained from 152 Caucasian subjects with biopsy-proven NAFLD due to persistently elevated liver enzyme levels. Metabolites representative of oxidative stress were assessed. The findings derived from this work revealed that NAFLD patients with a NASH score of ≥ 4 showed significantly higher levels of lipid peroxidation (LPO). Indeed, LPO levels above the optimal operating point (OOP) of 315.39 µM are an independent risk factor for presenting a NASH score of ≥ 4 (OR: 4.71; 95% CI: 1.68−13.19; p = 0.003). The area under the curve (AUC = 0.81, 95% CI = 0.73−0.89, p < 0.001) shows a good discrimination ability of the model. Therefore, understanding the molecular mechanisms underlying the basal inflammation present in these patients is postulated as a possible source of biomarkers and therapeutic targets in NASH.

Dynamic Protein-RNA recognition in primary MicroRNA processing.

MicroRNAs are prevalent regulators of gene expression, controlling most of the proteome in multicellular organisms. To generate the functional small RNAs, precise processing steps are required. In animals, microRNA biogenesis is initiated by Microprocessor that minimally consists of the Drosha enzyme and its partner, DGCR8. This first step is critical for selecting primary microRNAs, and many RNA-binding proteins and regulatory pathways target both the accuracy and efficiency of microRNA maturation. Structures of Drosha and DGCR8 in complex with primary microRNAs elucidate how RNA structural features rather than sequence provide the framework for substrate recognition. Comparing multiple states of Microprocessor and the closely related Dicer homologs shed light on the dynamic protein-RNA complex assembly and disassembly required to recognize RNAs with diverse sequences via common structural features.

Adrenocortical carcinoma, case report.

The adrenocortical carcinoma is rare and aggressive. It has a bimodal presentation, predominantly female, > 20% of cases will be diagnosed incidentally. 43-year-old male, with colic pain in the left flank, weight loss and intermittent fever. Computed tomography with a tumor on the left adrenal with liver metastases, block resection surgery was performed, pathological report of adrenocortical carcinoma with a 7 points of Weiss score and Ki67 40%. Adrenocortical carcinoma is a rare and aggressive neoplasm; the clinical presentation is variable. Systemic therapy is important even in patients with localized disease and independent of surgical approach.

El carcinoma corticoadrenal es una neoplasia rara, altamente agresiva, de distribución bimodal, con predominio en el sexo femenino, de la cual el 20% de los casos se diagnostican de manera incidental. Se presenta el caso de un varón de 43 años con dolor de tipo cólico en el flanco izquierdo, pérdida de peso y fiebre intermitente. La tomografía computarizada mostró un tumor en la glándula suprarrenal izquierda y metástasis hepática. Se realizó adrenalectomía radical en bloque, con reporte anatomopatológico de carcinoma corticoadrenal, Weiss de 7 puntos y Ki67 40%. El carcinoma corticoadrenal es una neoplasia agresiva y de presentación clínica variable. La terapia sistémica es importante incluso en pacientes con enfermedad localizada e independientemente de la cirugía.

Multimerization of Zika Virus-NS5 Causes Ciliopathy and Forces Premature Neurogenesis.

Zika virus (ZikV) is a flavivirus that infects neural tissues, causing congenital microcephaly. ZikV has evolved multiple mechanisms to restrict proliferation and enhance cell death, although the underlying cellular events involved remain unclear. Here we show that the ZikV-NS5 protein interacts with host proteins at the base of the primary cilia in neural progenitor cells, causing an atypical non-genetic ciliopathy and premature neuron delamination. Furthermore, in human microcephalic fetal brain tissue, ZikV-NS5 persists at the base of the motile cilia in ependymal cells, which also exhibit a severe ciliopathy. Although the enzymatic activity of ZikV-NS5 appears to be dispensable, the amino acids Y25, K28, and K29 that are involved in NS5 oligomerization are essential for localization and interaction with components of the cilium base, promoting ciliopathy and premature neurogenesis. These findings lay the foundation for therapies that target ZikV-NS5 multimerization and prevent the developmental malformations associated with congenital Zika syndrome.

Late metastasis of right breast cancer to renal pelvis and right ureter. A case report.

ANTECEDENTES: Las metástasis de mama a uréter son extremadamente raras y la mayoría son asintomáticas. CASO CLÍNICO: Mujer de 67 años, con cáncer de mama derecha EC IA luminal A de 5 años de evolución. Presentó infección de vías urinarias de repetición, hematuria macroscópica total y dolor renal derecho. La tomografía abdominopélvica mostró dilatación del cáliz superior y defecto de llenado en la pelvis renal derechos. Se le realizó nefroureterectomía radical derecha, rodete vesical. El reporte histopatológico fue metástasis de carcinoma infiltrante con afectación de pelvis renal y uréter. CONCLUSIONES: La metástasis tardía del cáncer de mama al uréter y la pelvis es rara. BACKGROUND: Breast metastases to ureter are extremely rare. Most are asymptomatic. CASE REPORT: A 67-year-old woman with 5 years of evolution, with right breast cancer stage IA luminal A. She presented repeated urinary tract infection, total macroscopic hematuria and pain in the right renal fossa. The computed tomography showed dilation of the upper calyx and filling defect in the renal pelvis. A right laparoscopic radical nephroureterectomy was realized; the histopathological report was metastasis of infiltrating carcinoma without specific pattern involving renal pelvis and ureter. CONCLUSIONS: Late metastasis of breast cancer to ureter and pelvis are rare.

Análisis de riesgo en la Medicina Nuclear Terapéutica en Cuba con enfoque integrador / Risk assessment in Therapeutic Nuclear Medicine in Cuba with an integrated approach

Introducción: El análisis de riesgo en la gestión de la calidad y seguridad permite la mejora continua de los servicios médicos en Cuba. En Medicina Nuclear Terapéutica es requisito regulador que permite la continuidad de estos servicios a la población. Objetivo: Analizar los riesgos radiológicos con enfoque integrador dirigido a causas básicas de fallo en la práctica citada. Material y métodos: Se revisó y adaptó el modelo genérico de riesgo para cada caso de estudio. Los métodos prospectivos de matriz de riesgo y análisis de modos y efectos de fallo y reactivo de aprendizaje de las lecciones de sucesos registrados fueron utilizados con el código cubano SECURE MR-FMEA versión 3.0. Se determinó el riesgo inherente, su tratamiento y el riesgo residual por práctica. Se identificaron las etapas del proceso, las medidas y las causas básicas más contribuyentes. Resultados: No se obtuvo riesgo superior al del nivel alto. La radiosinoviortesis y el tratamiento radiactivo de la policitemia vera tuvieron la mayor cantidad de modificaciones al modelo genérico. Las etapas más significativas son prescripción clínica, preparación del radiofármaco y administración. Las medidas preventivas de mayor importancia son mantener una carga de trabajo moderada para el personal, las capacitaciones de los médicos nucleares y del técnico que realiza la administración. Conclusiones: Existe una no uniformidad en el nivel de calidad y seguridad entre los servicios analizados. Para el cambio, la adopción de decisiones se ve beneficiada en su eficacia y eficiencia, al integrarse los métodos prospectivos y reactivos de análisis de riesgo(AU)

Introduction: Risk assessment in quality and safety management allows the continuous improvement of the medical services in Cuba. In Therapeutic Nuclear Medicine, it is a regulatory requirement which allows the continuity of these services to the population. Objective: To assess radiological risks with an integrated approach focused on underlying causes of failure in the mentioned practice. Material and Methods: The generic risk model was reviewed and adapted for each case study. The prospective methods of risk assessment matrix of failure modes and effects and incident learning lessons from the events registered were used applying the Cuban code SECURE MR-FMEA version 3.0. The inherent risk, treatment, and residual risk in the practice were determined. The stages of the process, measurements, and the main contributing causes were identified. Results: There was no risk higher than the high level. Radiosynoviorthesis and the radioactive treatment of the Polycythemia Vera had the greatest amount of modifications to the generic model. The most significant stages are clinical prescription, preparation of the radiopharmaceutical formulation and administration. The most important preventive measures are to maintain a moderate workload for the personnel, and the training of the nuclear physicians and the technician who performs the administration. Conclusions: There is a non-uniformity in the level of quality and safety among the NTM services in Cuba. For change, decision-making is benefited in terms of effectiveness and efficiency by integrating prospective and reactive risk assessment methods(AU)

Colorado potato beetle chymotrypsin genes are differentially regulated in larval midgut in response to the plant defense inducer hexanoic acid or the Bacillus thuringiensis Cry3Aa toxin.

When Colorado potato beetle larvae ingested potato plants treated with the plant defense inducer compound hexanoic acid, midgut chymotrypsin enzyme activity increased, and the corresponding chymotrypsin genes were differentially expressed, evidence of the larval digestive proteolytic system's plasticity. We previously reported increased susceptibility to Cry3Aa toxin in larvae fed hexanoic acid treated plants. Here we show that the most expressed chymotrypsin gene in larvae fed hexanoic acid treated plants, CTR6, was dramatically downregulated in Cry3Aa intoxicated larvae. lde-miR-965-5p and lde-miR-9a-5p microRNAs, predicted to target CTR6, might be involved in regulating the response to hexanoic acid but not to Cry3Aa toxin.

Supramolecular arrangement of the full-length Zika virus NS5.

Zika virus (ZIKV), a member of the Flaviviridae family, has emerged as a major public health threat, since ZIKV infection has been connected to microcephaly and other neurological disorders. Flavivirus genome replication is driven by NS5, an RNA-dependent RNA polymerase (RdRP) that also contains a N-terminal methyltransferase domain essential for viral mRNA capping. Given its crucial roles, ZIKV NS5 has become an attractive antiviral target. Here, we have used integrated structural biology approaches to characterize the supramolecular arrangement of the full-length ZIKV NS5, highlighting the assembly and interfaces between NS5 monomers within a dimeric structure, as well as the dimer-dimer interactions to form higher order fibril-like structures. The relative orientation of each monomer within the dimer provides a model to explain the coordination between MTase and RdRP domains across neighboring NS5 molecules and mutational studies underscore the crucial role of the MTase residues Y25, K28 and K29 in NS5 dimerization. The basic residue K28 also participates in GTP binding and competition experiments indicate that NS5 dimerization is disrupted at high GTP concentrations. This competition represents a first glimpse at a molecular level explaining how dimerization might regulate the capping process.

A model species for agricultural pest genomics: the genome of the Colorado potato beetle, Leptinotarsa decemlineata (Coleoptera: Chrysomelidae).

The Colorado potato beetle is one of the most challenging agricultural pests to manage. It has shown a spectacular ability to adapt to a variety of solanaceaeous plants and variable climates during its global invasion, and, notably, to rapidly evolve insecticide resistance. To examine evidence of rapid evolutionary change, and to understand the genetic basis of herbivory and insecticide resistance, we tested for structural and functional genomic changes relative to other arthropod species using genome sequencing, transcriptomics, and community annotation. Two factors that might facilitate rapid evolutionary change include transposable elements, which comprise at least 17% of the genome and are rapidly evolving compared to other Coleoptera, and high levels of nucleotide diversity in rapidly growing pest populations. Adaptations to plant feeding are evident in gene expansions and differential expression of digestive enzymes in gut tissues, as well as expansions of gustatory receptors for bitter tasting. Surprisingly, the suite of genes involved in insecticide resistance is similar to other beetles. Finally, duplications in the RNAi pathway might explain why Leptinotarsa decemlineata has high sensitivity to dsRNA. The L. decemlineata genome provides opportunities to investigate a broad range of phenotypes and to develop sustainable methods to control this widely successful pest.

Oxylipin mediated stress response of a miraculin-like protease inhibitor in Hexanoic acid primed eggplant plants infested by Colorado potato beetle.

Insect-plant interactions are governed by a complex equilibrium between the mechanisms through which plant recognize insect attack and orchestrate downstream signaling events that trigger plant defense responses, and the mechanisms by which insects overcome plant defenses. Due to this tight and dynamic interplay, insight into the nature of the plant defense response can be gained by analyzing changes in the insect herbivores digestive system upon plant feeding. In this work we have identified a Solanum melongena miraculin-like protease inhibitor in the midgut juice of Colorado potato larvae feeding on eggplant plants treated with the natural inducer of plant defenses hexanoic acid. We analyzed the corresponding gene expression by qRT-PCR and our results showed that this eggplant miraculin-like gene enhanced induction contributes to the hexanoic acid priming effect in this Solanaceae species. Moreover, our data evidencing that OPDA might be involved in this gene regulation highlights its potential as biomarker in eggplant plant responses to stress mediated this oxylipin signaling pathway.

[Husband to wife kidney transplantation in five multiparous women: sensitization or tolerance after pregnancy?]. / Trasplante renal de esposo a esposa en cinco mujeres multíparas. Efecto sensibilizante o efecto "tolerogénico" de la gestación?

BACKGROUND: Pregnancy is a known cause of immunological sensitization and it has been reported graft survival to be lower in husband to wife kidney transplantation if the wife had been pregnant (mutual children) as compare to those cases without pregnancies. Previous exposure to husband HLA antigens during pregnancies may lead to specific sensitization to subsequent allografts. AIM: To communicate the fate of kidney allograft in husband to wife transplantation when the recipient had been pregnant. PATIENTS AND METHODS: From 682 renal transplants performed at INCMNSZ 5 corresponded to husband to wife transplants. All the recipients were multiparous and had received multiple blood transfusions. Pretransplantation lymphocytotoxic cross-match testing were performed by complement dependent citotoxicity with antihuman globulin added (AHG-CDC), being negative in all cases for T and B cells. All the patients received triple-drug immunosuppressive therapy, additionally, anti-IL2R monoclonal antibodies were used in two cases. RESULTS: Two patients developed: accelerated acute rejection (case 1), and acute humoral rejection (case 5), respectively. Graft in these patients were loss to rejection and transplant nephrectomy accomplished. The remaining three patients (cases 2, 3, and 4) has not had any rejection episode, and have had excellent graft outcome at 34, 30, and 21 months posttransplant, respectively. CONCLUSIONS: Why under similar conditions some husband to wife kidney transplant recipients developed an adverse humoral immunological events while others maintain excellent long-term graft outcome? Is it possible to speculate that for some women pregnancy is in fact a sensitizing event, while in others it promotes "immunological acceptance"? At present there is no a test that characterized one and other group. Even though pretransplantation cross-match testing by flow cytometry is more sensitive than AHG-CDC, its negative result is by no means an absolute guarantee that an adverse anamnestic immunological event will not occur.