RESUMO
The grass family (Poaceae) includes cereal crops that provide a key food source for the human population. The food industry uses the starch deposited in the cereal grain, which develops directly from the gynoecium. Morphological interpretation of the grass gynoecium remains controversial. We re-examine earlier hypotheses and studies of morphology and development in the context of more recent analyses of grass phylogenetics and developmental genetics. Taken in isolation, data on gynoecium development in bistigmatic grasses do not contradict its interpretation as a solitary ascidiate carpel. Nevertheless, in the context of other data, this interpretation is untenable. Broad comparative analysis in a modern phylogenetic context clearly demonstrates that the grass gynoecium is pseudomonomerous. A bistigmatic grass gynoecium has two sterile carpels, each producing a stigma, and a fertile carpel that lacks a stigma. To date, studies of grass developmental genetics and developmental morphology have failed to fully demonstrate the composite nature of the grass gynoecium be-cause its complex evolutionary history is hidden by extreme organ integration. It is problematic to interpret the gynoecium of grasses in terms of normal angiosperm gynoecium typology. Even the concept of a carpel becomes misleading in grasses; instead, we recommend the term pistil for descriptive purposes.
Assuntos
Magnoliopsida , Poaceae , Evolução Biológica , Flores , Humanos , Magnoliopsida/anatomia & histologia , Filogenia , Poaceae/genéticaRESUMO
In 2019, at the World Economic Forum, DNA data storage was indicated as one of the breakthroughs expected to radically impact the global socio-economic order. Indeed, dry DNA is a relatively stable substance and an extremely capacious information carrier. One gram of DNA can hold up to 455 exabytes, provided that one nucleotide encodes two bits of information. In this critical review, the main attention is paid to nucleinography, meaning the conversion of digital data into nucleotide sequences. The evolution and diversity of approaches intended for encoding data with nucleotides are demonstrated. The most noticeable examples of storing minor as well as considerable quantities of non-biological information in DNA are given. Some issues of DNA data storage are also reported.
Assuntos
DNA , Armazenamento e Recuperação da Informação , Sequência de Bases , DNA/genética , Análise de Sequência de DNARESUMO
Polymerase chain reaction (PCR) is the most widely used method for nucleic acids amplification. To date, a huge number of versatile PCR techniques have been developed. One of the relevant goals is to shorten PCR duration, which can be achieved in several ways. Here, we report on the results regarding nucleic acids amplification by convective PCR (cPCR) in standard 0.2 ml polypropylene microtubes. The following conditions were found to be optimal for such amplification: 1) 70 µl reaction volume, 2) the supply of external temperature 145°Ð¡ for the denaturation zone and 0°Ð¡ for the annealing zone, 3) â¼30° inclination of the microtube main axis, 4) the use of nearby primers, and 5) duration of the reaction 15-20 min. At these conditions, the amplification products are accumulated in an amount sufficient to be registered by gel electrophoresis, and high sensitivity of the reaction comparable to that of conventional PCR is achieved. cPCR provided the reliable detection of SARS-CoV-2 coronavirus RNA isolated from nasopharyngeal swabs of COVID-19 patients.
Assuntos
Teste de Ácido Nucleico para COVID-19/instrumentação , COVID-19/diagnóstico , Reação em Cadeia da Polimerase/instrumentação , SARS-CoV-2/isolamento & purificação , COVID-19/virologia , Teste de Ácido Nucleico para COVID-19/economia , Teste de Ácido Nucleico para COVID-19/métodos , Convecção , Humanos , Reação em Cadeia da Polimerase/economia , Reação em Cadeia da Polimerase/métodos , RNA Viral/análise , RNA Viral/genética , SARS-CoV-2/genética , Temperatura , Fatores de TempoRESUMO
Introduction: Understanding the complex inflorescence architecture and developmental morphology of common buckwheat (Fagopyrum esculentum) is crucial for crop yield. However, most published descriptions of early flower and inflorescence development in Polygonaceae are based on light microscopy and often documented by line drawings. In Fagopyrum and many other Polygonaceae, an important inflorescence module is the thyrse, in which the primary axis never terminates in a flower and lateral cymes (monochasia) produce successively developing flowers of several orders. Each flower of a cyme is enclosed together with the next-order flower by a bilobed sheathing bract-like structure of controversial morphological nature. Methods: We explored patterns of flower structure and arrangement in buckwheat and its wild relatives, using comparative morphology, scanning electron microscopy and X-ray microtomography. Results: Our data support interpretation of the sheathing bract as two congenitally fused phyllomes (prophylls), one of which subtends a next-order flower. In tepal-like bract, a homeotic mutant of F. esculentum, the bilobed sheathing bract-like organ acquires tepal-like features and is sometimes replaced by two distinct phyllomes. Wild representatives of F. esculentum (ssp. ancestrale) and most cultivars of common buckwheat possess an indeterminate growth type with lateral thyrses produced successively on the primary inflorescence axis until cessation of growth. In contrast, determinate cultivars of F. esculentum develop a terminal thyrse after producing lateral thyrses. In contrast to F. esculentum, the occurrence of a terminal thyrse does not guarantee a determinate growth pattern in F. tataricum. The number of lateral thyrses produced before the terminal thyrse on the main axis of F. tataricum varies from zero to c. 19. Discussion: The nine stages of early flower development formally recognized here and our outline of basic terminology will facilitate more standardized and readily comparable descriptions in subsequent research on buckwheat biology. Non-trivial relative arrangements of tepals and bracteoles in Fagopyrum and some other Polygonaceae require investigation using refined approaches to mathematical modelling of flower development. Our data on inflorescence morphology and development suggest contrasting evolutionary patterns in the two main cultivated species of buckwheat, F. esculentum and F. tataricum. The genus Fagopyrum offers an excellent opportunity for evo-devo studies related to inflorescence architecture.
RESUMO
ß-Ketophosphonates with pentalenofurane fragments linked to the keto group were synthesized. The bulky pentalenofurane skeleton is expected to introduce more hindrance in the prostaglandin analogues of type III, greater than that obtained with the bicyclo[3.3.0]oct(a)ene fragments of prostaglandin analogues I and II, to slow down (retard) the inactivation of the prostaglandin analogues by oxidation of 15α-OH to the 15-keto group via the 15-PGDH pathway. Their synthesis was performed by a sequence of three high yield reactions, starting from the pentalenofurane alcohols 2, oxidation of alcohols to acids 3, esterification of acids 3 to methyl esters 4 and reaction of the esters 4 with lithium salt of dimethyl methanephosphonate at low temperature. The secondary compounds 6b and 6c were formed in small amounts in the oxidation reactions of 2b and 2c, and the NMR spectroscopy showed that their structure is that of an ester of the acid with the starting alcohol. Their molecular structures were confirmed by single crystal X-ray determination method for 6c and XRPD powder method for 6b.
Assuntos
Cetonas/química , Organofosfonatos/química , Prostaglandinas Sintéticas/síntese química , Técnicas de Química Sintética , Cristalografia por Raios X , Modelos Moleculares , Conformação Molecular , Estrutura Molecular , Prostaglandinas Sintéticas/química , Sesquiterpenos/químicaRESUMO
BACKGROUND: The extreme southwest of Australia is a biodiversity hotspot region that has a Mediterranean-type climate and numerous endemic plant and animal species, many of which remain to be properly delimited. We refine species limits in Anarthria, a Western Australian endemic genus characterised by the occurrence of the greatest number of plesiomorphic character states in the restiid clade of Poales. In contrast to many other groups of wind-pollinated Australian Poales, Anarthria was traditionally viewed as having well-established species limits. All six currently recognised species, which are conspicuous members of some Western Australian plant communities, were described in the first half of the 19th century. They are traditionally distinguished from each other mainly using quantitative characters. METHODS: We examined extensive existing herbarium specimens and made new collections of Anarthria in nature. Scanning electron microscopy and light microscopy were used to study leaf micromorphology. Molecular diversity of Anarthria was examined using a plastid (trnL-F) and a low-copy nuclear marker (at103). This is the first study of species-level molecular diversity in the restiid clade using a nuclear marker. RESULTS: Material historically classified as Anarthria gracilis R.Br. actually belongs to three distinct species, A. gracilis s.str., A. grandiflora Nees and A. dioica (Steud.) C.I.Fomichev, each of which forms a well-supported clade in phylogenetic analyses. Both segregate species were described in the first half of the 19th century but not recognised as such in subsequent taxonomic accounts. Anarthria dioica was first collected in 1826, then wrongly interpreted as a species of Juncus (Juncaceae) and described as Juncus dioicus. We provide a formal transfer of the name to Anarthria and for the first time report its clear and qualitative diagnostic characters: an extremely short leaf ligule and distinctive pattern of leaf epidermal micromorphology. A long ligule is present in A. gracilis s.str. and A. grandiflora. These species differ from each other in leaf lamina morphology and anatomy and have mostly non-overlapping distribution ranges. The narrower definition of species provides a basis for future phylogeographic analyses in Anarthria. Our study highlights a need for more extensive use of nuclear DNA markers in Restionaceae. The use of the low copy nuclear marker at103 allowed a clade comprising all three ligulate species of Anarthria to be recognised. The ligule character is used here for the first time in the taxonomy of Anarthria and merits special attention in studies of other restiids. In general, our study uncovered a superficially hidden but, in reality, conspicuous diversity in a common group of wind-pollinated plants in the southwest of Western Australia.
RESUMO
New 1'-homocarbanucleoside analogs with an optically active substituted bicyclo[2.2.1]heptane skeleton as sugar moiety were synthesized. The pyrimidine analogs with uracil, 5-fluorouracil, thymine and cytosine and key intermediate with 6-chloropurine (5) as nucleobases were synthesized by a selective Mitsunobu reaction on the primary hydroxymethyl group in the presence of 5-endo-hydroxyl group. Adenine and 6-substituted adenine homonucleosides were obtained by the substitution of the 6-chlorine atom of the key intermediate 5 with ammonia and selected amines, and 6-methoxy- and 6-ethoxy substituted purine homonucleosides by reaction with the corresponding alkoxides. No derivatives appeared active against entero, yellow fever, chikungunya, and adeno type 1viruses. Two compounds (6j and 6d) had lower IC50 (15 ± 2 and 21 ± 4 µM) and compound 6f had an identical value of IC50 (28 ± 4 µM) to that of acyclovir, suggesting that the bicyclo[2.2.1]heptane skeleton could be further studied to find a candidate for sugar moiety of the nucleosides.
Assuntos
Antivirais/química , Antivirais/farmacologia , Glicosídeos/química , Heptanos/química , Nucleosídeos/química , Nucleosídeos/farmacologia , Desenho de Fármacos , Humanos , Ligantes , Testes de Sensibilidade Microbiana , Conformação Molecular , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Estrutura Molecular , Nucleosídeos/análogos & derivados , Purinas/química , Análise Espectral , Relação Estrutura-Atividade , Açúcares/químicaRESUMO
Hydroboration-oxidation of 2α,4α-dimethanol-1ß,5ß-bicyclo[3.3.0]oct-6-en dibenzoate (1) gave alcohols 2 (symmetric) and 3 (unsymmetric) in ~60% yield, together with the monobenzoate diol 4a (37%), resulting from the reduction of the closer benzoate by the intermediate alkylborane. The corresponding alkene and dialdehyde gave only the triols 8 and 9 in ~1:1 ratio. By increasing the reaction time and the temperature, the isomerization of alkylboranes favours the un-symmetrical triol 9. The PDC oxidation of the alcohols gave cleanly the corresponding ketones 5 and 6 and the deprotection of the benzoate groups gave the symmetrical ketone 14, and the cyclic hemiketal 15, all in high yields. The ethylene ketals of the symmetrical ketones 11 and 13 were also obtained. The compounds 5, 6, 11, 13, 14 could be used for synthesis of new (iso)carbacyclin analogues. The structure of the compounds was established by NMR spectroscopy and confirmed by X-ray crystallography.
Assuntos
Boranos/química , Epoprostenol/análogos & derivados , Cristalografia por Raios X , Epoprostenol/síntese química , Epoprostenol/química , Estrutura Molecular , OxirreduçãoRESUMO
Cystic fibrosis (CF) is a genetic disease caused by mutations in the CF transmembrane conductance regulator (CFTR) gene, resulting in a deficiency in chloride channel activity. In this study, extracellular vesicles (EVs), microvesicles, and exosomes were used as vehicles to deliver exogenous CFTR glycoprotein and its encoding mRNA (mRNA(GFP-CFTR)) to CF cells to correct the CFTR chloride channel function. We isolated microvesicles and exosomes from the culture medium of CFTR-positive Calu-3 cells, or from A549 cells transduced with an adenoviral vector overexpressing a GFP-tagged CFTR (GFP-CFTR). Both microvesicles and exosomes had the capacity to package and deliver the GFP-CFTR glycoprotein and mRNA(GFP-CFTR) to target cells in a dose-dependent manner. Homologous versus heterologous EV-to-cell transfer was studied, and it appeared that the cellular uptake of EVs was significantly more efficient in homologous transfer. The incubation of CF15 cells, a nasal epithelial cell line homozygous for the ΔF508 CFTR mutation, with microvesicles or exosomes loaded with GFP-CFTR resulted in the correction of the CFTR function in CF cells in a dose-dependent manner. A time-course analysis of EV-transduced CF cells suggested that CFTR transferred as mature glycoprotein was responsible for the CFTR-associated channel activity detected at early times posttransduction, whereas GFP-CFTR translated from exogenous mRNA(GFP-CFTR) was responsible for the CFTR function at later times. Collectively, this study showed the potential application of microvesicles and exosomes as vectors for CFTR transfer and functional correction of the genetic defect in human CF cells.
Assuntos
Micropartículas Derivadas de Células/química , Regulador de Condutância Transmembrana em Fibrose Cística/genética , Células Epiteliais/metabolismo , Vesículas Extracelulares/química , Terapia Genética/métodos , RNA Mensageiro/genética , Transdução Genética/métodos , Adenovírus Humanos/genética , Adenovírus Humanos/metabolismo , Linhagem Celular Tumoral , Micropartículas Derivadas de Células/metabolismo , Regulador de Condutância Transmembrana em Fibrose Cística/metabolismo , Células Epiteliais/patologia , Exossomos/química , Exossomos/metabolismo , Vesículas Extracelulares/metabolismo , Expressão Gênica , Vetores Genéticos/química , Vetores Genéticos/metabolismo , Proteínas de Fluorescência Verde/genética , Proteínas de Fluorescência Verde/metabolismo , Células HEK293 , Humanos , RNA Mensageiro/metabolismo , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo , Mucosa Respiratória/metabolismo , Mucosa Respiratória/patologiaRESUMO
New nucleoside analogues with an optically active bicyclo[2.2.1]heptane skeleton as sugar moiety and 6-substituted adenine were synthesized by alkylation of 6-chloropurine intermediate. Thymine and uracil analogs were synthesized by building the pyrimidine ring on amine 1. X-ray crystallography confirmed an exo-coupling of the thymine to the ring and an L configuration of the nucleoside analogue. The library of compounds was tested for their inhibitory activity against influenza virus A∖California/07/09 (H1N1)pdm09 and coxsackievirus B4 in cell culture. Compounds 13a and 13d are the most promising for their antiviral activity against influenza, and compound 3c against coxsackievirus B4. Compounds 3b and 3g were tested for anticancer activity.
Assuntos
Nucleotídeos de Adenina/química , Antineoplásicos/síntese química , Antivirais/síntese química , Compostos Bicíclicos com Pontes/química , Nucleosídeos de Pirimidina/química , Animais , Antineoplásicos/farmacologia , Antivirais/farmacologia , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Chlorocebus aethiops , Cristalografia por Raios X , Cães , Ensaios de Seleção de Medicamentos Antitumorais , Enterovirus Humano B/efeitos dos fármacos , Humanos , Vírus da Influenza A Subtipo H1N1/efeitos dos fármacos , Células Madin Darby de Rim Canino , Conformação Molecular , Relação Estrutura-Atividade , Células VeroRESUMO
A better knowledge of synovial fluid (SF) ultrastructure is required to further understand normal joint lubrication and metabolism. The aim of the present study was to elucidate SF structural features in healthy joints from three mammalian species of different size compared with features in biomimetic SF. High-resolution structural analysis was performed using transmission electron microscopy (TEM) and scanning electron microscopy (SEM) and environmental SEM/wet scanning transmission electron microscopy mode complemented by TEM and SEM cryogenic methods. Laser-scanning confocal microscopy (LCM) was used to locate the main components of SF with respect to its ultrastructural organization. The present study showed that the ultrastructure of healthy SF is built from a network of vesicles with a size range from 100 to a few hundred nanometers. A multilayered organization of the vesicle membranes was observed with a thickness of about 5 nm. LCM study of biological SF compared with synthetic SF showed that the microvesicles consist of a lipid-based membrane enveloping a glycoprotein gel. Thus, healthy SF has a discontinuous ultrastructure based on a complex network of microvesicles. This finding offers novel perspectives for the diagnosis and treatment of synovial joint diseases.
Assuntos
Líquido Sinovial , Vesículas Transportadoras/ultraestrutura , Animais , Cães , Cavalos , Articulações/fisiologia , Microscopia Confocal , Microscopia Eletrônica de Varredura , Microscopia Eletrônica de Transmissão e Varredura , Microscopia Eletrônica de Transmissão , Ratos , Vesículas Transportadoras/químicaRESUMO
An amine group was synthesized starting from an optically active bicyclo[2.2.1]heptane compound, which was then used to build the 5 atoms ring of a key 6-chloropurine intermediate. This was then reacted with ammonia and selected amines obtaining new adenine- and 6-substituted adenine conformationally constrained carbocyclic nucleoside analogues with a bicyclo[2.2.1]heptane skeleton in the sugar moiety. X-ray crystallography confirmed an exo-coupling of base to the ring and a L configuration of the nucleoside analogues. The compounds were tested for anticancer activity.
Assuntos
Antineoplásicos/síntese química , Heptanos/química , Nucleosídeos/química , Antineoplásicos/uso terapêutico , Cristalografia por Raios X , Humanos , Conformação Molecular , Estrutura Molecular , EstereoisomerismoRESUMO
Cinnamic acids have been prepared in moderate to high yields by a new direct synthesis using aromatic aldehydes and aliphatic carboxylic acids, in the presence of boron tribromide as reagent, 4-dimethylaminopyridine (4-DMAP) and pyridine (Py) as bases and N-methyl-2-pyrolidinone (NMP) as solvent, at reflux (180-190 degrees C) for 8-12 hours.
Assuntos
Aldeídos/química , Compostos de Boro/farmacologia , Brometos/farmacologia , Ácidos Carboxílicos/química , Química Orgânica/métodos , Cinamatos/síntese química , Compostos de Boro/química , Brometos/química , Ácidos Graxos/química , Compostos Heterocíclicos/química , Modelos BiológicosRESUMO
BACKGROUND/AIMS: Overexpression of nitric oxide (NO) has been implicated in the pathogenesis of experimental and clinical inflammatory bowel disease (IBD). NO is produced by two types of enzymes: constitutively expressed and inducible NO synthases (NOS). This study assessed N(W)-nitro-L-arginine methyl ester (L-NAME) and aminoguanidine (AMG), the most studied inhibitors of nitric oxide synthases, with regard to their effectiveness as modulators of inflammation in trinitrobenzene sulfonic acid (TNBS)-induced colitis in the rat. MATERIALS AND METHODS: Colitis was induced in Wistar rats. The colitis was treated everyday for 10 days with L-NAME and AMG. To assess the severity of the colitis, clinical (body weight), hematological (hematocrit and erythrocytes sedimentation rate-ESR) and morphological (gross and microscopic) criteria were used. RESULTS: The administration of both nitric oxide synthases inhibitors L-NAME and AMG proved to be beneficial in all the examined parameters compared with the control group. A statistically significant difference between the L-NAME and the AMG groups was observed only in macroscopic and histological grading. CONCLUSION: NOS inhibitors may be promising agents in preventing the onset, or mediating the symptoms, of inflammatory bowel disease.
Assuntos
Colite Ulcerativa/tratamento farmacológico , Inibidores Enzimáticos/uso terapêutico , Guanidinas/uso terapêutico , NG-Nitroarginina Metil Éster/uso terapêutico , Óxido Nítrico Sintase/antagonistas & inibidores , Animais , Sedimentação Sanguínea , Peso Corporal/efeitos dos fármacos , Colite Ulcerativa/induzido quimicamente , Colite Ulcerativa/patologia , Modelos Animais de Doenças , Hematócrito , Masculino , Ratos , Ratos Wistar , Resultado do TratamentoRESUMO
By analysing in 2,769 patients the relation between bucco-dental pathology and age, it was noticed that the frequency of odontic affections decreases and that of chronic marginal periodontopathies increases with age. In the elderly, a tendency towards delaying the treatment of pulp inflammations and a very high percentage of extractions performed in the chronic marginal periodontopathies (81.8%) were noticed. The bucco-dental state of health was determined in 75 old-aged over 60 years, the ICORA and CPITN indices being used. Of these individuals, 93.3% presented various edentate forms, half without prosthetic appliance. Various degrees of pathological changes in the marginal periodontium were recorded in 92.3%, being more severe in women and individuals from rural areas.
Assuntos
Doenças da Boca/epidemiologia , Saúde Bucal , Doenças Dentárias/epidemiologia , Fatores Etários , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Índice Periodontal , Romênia/epidemiologiaRESUMO
Investigations on hygiene and sanitary conditions in a laboratory for dental techniques consisted in physico-chemical determinations on microclimate (temperature, humidity, air currents), determination of dust particles (suspended and sedimented), determination of gases (CO, CO2, NO2, NH3, SO4(2-), chloride ions), and determination of microelements (Fe, Cu, Zn, Ni, Cd). In certain conditions the concentrations for dust, NO2, NH3, SO2(4-), chlorine and Cu were above the maximal accepted levels. Measures should be taken for the prevention and for the elimination of these noxious factors by implementing optimal hygienic conditions (heat, humidity, ventilation), by reducing gas emanations, by using protections equipment (mask, eyeglasses, gloves), and by periodic controls of the health status of dental technicians.