Hordeum vulgare CYP76M57 catalyzes C2 shortening of tryptophan side chain by C-N bond rearrangement in gramine biosynthesis.

The indole alkaloid gramine, 3-(dimethylaminomethyl)indole, is a defensive specialized metabolite found in some barley cultivars. In its biosynthetic process, the tryptophan (Trp) side chain is shortened by two carbon atoms to produce 3-(aminomethyl)indole (AMI), which is then methylated by N-methyltransferase (HvNMT) to produce gramine. Although side chain shortening is one of the crucial scaffold formation steps of alkaloids originating from aromatic amino acids, the gene and enzyme involved in the Trp-AMI conversion reactions are unknown. In this study, through RNA-seq analysis, 35 transcripts were shown to correlate with gramine production; among them, an uncharacterized cytochrome P450 (CYP) gene, CYP76M57, and HvNMT were identified as candidate genes for gramine production. Transgenic Arabidopsis thaliana and rice overexpressing CYP and HvNMT accumulate AMI, N-methyl-AMI, and gramine. CYP76M57, heterologously expressed in Pichia pastoris, was able to act on Trp to produce AMI. Furthermore, the amino group nitrogen of Trp was retained during the CYP76M57-catalyzed reaction, indicating that the C2 shortening of Trp proceeds with an unprecedented biosynthetic process, the removal of the carboxyl group and Cα and the rearrangement of the nitrogen atom to Cß. In some gramine-non-accumulating barley cultivars, arginine 104 in CYP76M57 is replaced by threonine, which abolished the catalytic activity of CYP76M57 to convert Trp into AMI. These results uncovered the missing committed enzyme of gramine biosynthesis in barley and contribute to the elucidation of the potential functions of CYPs in plants and undiscovered specialized pathways.

Detection of a novel intramolecular rearrangement during gramine biosynthesis in barley using stable isotope-labeled tryptophan.

Plants accumulate various secondary metabolites, and the biosynthetic reactions responsible for their scaffold construction are the key steps that characterize their structural categories. Gramine, an indole alkaloid, is a defensive secondary metabolite biosynthesized in barley (Hordeum vulgare) from tryptophan (Trp) via aminomethylindole (AMI). While the two sequential N-methylation steps following the formation of AMI have already been characterized both genetically and enzymatically, the step preceding AMI formation, which includes the Trp side chain-shortening, has not yet been revealed. To gain further insight into these biosynthetic reactions, barley seedlings were fed Trp labeled with stable isotopes (13C and 15N) at various positions, and the isotope incorporation into gramine was analyzed by liquid chromatography/mass spectrometry. Significant increases in the abundance of isotopic gramine were detected in experimental sets in which Trp was labeled at either the indole ring, the ß-carbon, or the amino group, whereas the isotopolog composition was not affected by α-carbon-labeled Trp. Although absorbed Trp presumably undergoes transamination in plants, this reaction did not seem to be related to gramine productivity. The data indicated that AMI directly inherited the amino group from Trp, while the α-carbon was removed, suggesting that the Trp-AMI conversion includes a novel intramolecular rearrangement reaction. The results of this study provide novel insights into scaffold formation in plant secondary-metabolite synthesis.

RNase in the saliva can affect the detection of severe acute respiratory syndrome coronavirus 2 by real-time one-step polymerase chain reaction using saliva samples.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a single-stranded RNA virus that causes coronavirus disease 2019, which spread worldwide immediately after the first patient infected with this virus was discovered in Wuhan, China, in December 2019. Currently, polymerase chain reaction (PCR) specimens for the detection of SARS-CoV-2 include saliva, nasopharyngeal swabs, and lower respiratory tract-derived materials such as sputum. Initially, nasopharyngeal swab specimens were applied mainly to the PCR detection of SARS-CoV-2. There was a risk of infection to healthcare workers due to coughing or sneezing by the subjects at the time of sample collection. In contrast, saliva specimens have a low risk of droplet infection and are easy to collect, and their application to PCR testing has been promoted. In this study, we have determined the detection limit of SARS-CoV-2 in saliva samples and examined the effects of storage temperature and storage time of saliva samples on the PCR detection results. As a result, 5 × 103 copies of SARS-CoV-2 could be detected in 1 mL phosphate-buffered saline, whereas 5 × 104 copies of SARS-CoV-2 were needed in 1 mL saliva to detect the virus by real-time one-step PCR. Interestingly, SARS-CoV-2 (5 × 103 copies/mL) could be detected in saliva supplemented with an RNase inhibitor. Concerning the saliva samples supplemented with an RNase inhibitor, the optimal temperature for sample storage was -20 °C, and PCR detection was maintained within 48 h without problems under these conditions. These finding suggest that RNase in the saliva can affect the detection of SARS-CoV-2 by PCR using saliva samples.

Características faciales y oclusales en niños con hábitos bucales / Occlusal and facial features in childrenwith oral habits

Fueron analizadas asociaciones entre tipos faciales, características oclusales y hábitos bucales. La muestra consistió de 1.923 escolares de 8 a 12 años (959 niñas, 964 niños) de Campo Grande, MS-Brasil. Comparaciones entre las características evaluadas según los hábitos fueron realizadas por testes de proporción e Chi-cuadrado (a = 5%). La prevalencia de hábitos fue de 37,4%. Hubo diferencia entre géneros, 55% (femenino) y 45% (masculino). Las mayores prevalencias fueron verificadas en el grupo de 8 años (32%) y en los colegios particulares (40,9%). Oñicofagia fue el más prevalente (71,7%), seguida por succión digital (9,7%) e interposición lingual (6,4%). En la mayoría de los grupos de hábitos, se observaron elevadas frecuencias de simetría facial (81-100%). En los que hacían succión digital, los tipos dolicofacial (46%) y mesofacial (43%) fueron significativamente más prevalentes, así como en los que presentaban interposición lingual, con respectivos porcentajes de 54% e 39%. De los portadores de hábitos, 76,9% tenían competencia labial. Las prevalencias de perfil convexo fueron significantemente más altas en los grupos de interposición lingual (85%), succión digital (83%) y oñicofagia (77%). En ellos, las prevalencias de overjet (52%) y trepase vertical (45%) normales fueron significativamente elevadas; sin embargo, en los alumnos con interposición lingual, la mordida abierta anterior fue la más prevalente (67%). La mordida cruzada posterior no fue asociada a los hábitos. A pesar del histórico de hábitos en 720 escolares, hubo asociación con simetría facial, tipos dolicofacial y mesofacial, competencia labial y perfil convexo. No se observó el predominio de maloclusiones.

Associations among facial types, occlusal features and oral habits were analyzed. The sample consisted of 1,923 students aged 8 to 12 years old (959 girls, 964 boys) from Campo Grande, MS-Brazil. Comparisons among the studied characteristics, which were evaluated according to the habits, were carried out using ratio and Chi-square tests (a = 5%). The prevalence of oral habits was 37.4%. There was a difference between genders: 55% for females and 45% for males. The highest prevalence was observed in the group of eight-year-olds (32%) and in private schools (40.9%). Nail biting was the most prevalent habit (71.7%), followed by digit-sucking (9.7%) and tongue thrusting (6.4%). In most of the habit groups, high frequencies of facial symmetry were observed (81-100%). In those who had digit-sucking habit, dolichofacial (46%) and mesofacial (43%) patterns were significantly more prevalent, as well as in those which presented tongue thrusting, with percentages of 54% and 39%, respectively. Of the habit holders, 76.9% presented lip competence. The prevalence of convex profile was significantly higher in the groups of tongue thrusting (85%), digit-sucking (83%) and nail biting (77%). In those students, frequencies of normal overjet (52%) and overbite (45%) were significantly great; but, in the group with tongue thrusting, anterior open bite was the most prevalent feature (67%). Posterior crossbite was not associated with the habits. Despite the history of habits in 720 students, there was an association with the facial symmetry, dolichofacial and mesofacial patterns, lip competence and convex profile. Malocclusions predominance was not observed.

O expansor mandibular de Prieto associado à ortodontia lingual: relato de caso clínico / Prieto mandibular expander associated with lingual orthodontics: a clinical-case report

Sendo os desgastes interproximais uma necessidade em casos de discrepância negativa em que não se aplica a extração de pré-molares, acreditamos que expandir previamente os arcos facilita tal mecânica. Para que se consiga um tratamento previsível é preferível que se utilize de dispositivos fixos quando se opta por tal procedimento. Este trabalho enfoca esta abordagem com a apresentação de dois casos clínicos que foram tratados pela Técnica Lingual.

When interproximal stripping is required in cases of negative discrepancy in which extraction of premolars is not recommended, it is the authors view that prior expansion the arches facilitates the stripping procedure. For predictable outcomes, fixed appliances are to be preferred for this type of treatment. This study describes two clinical cases that this approach was used in conjunction with Lingual Orthodontics.

Pêndulo higiênico de Prieto / Prieto's hygienic pendulum

Dos dispositivos de cooperação mínima, o aparelho pêndulo é um dos que mais satisfaz o clínico, quando se deseja aplicar força de distalização aos molares. Um dos poucos inconvenientes deste aparelho é a necessidade de colaboração do paciente para manter higienizada a região do palato onde repousa o botão de resina acrílica e o fato de que, em alguns casos, ocorre a compressão da mucosa. Visando eliminar os inconvenientes acima citados, este artigo propôs uma forma alternativa de utilização das molas de TMA, com o objetivo de mover os molares para distal. Desta forma, apresentamos um modelo de aparelho distalizador que emprega molas de TMA removíveis, com a eliminação do botão de acrílico e constituindo a unidade de ancoragem apenas com suporte dentário.

Estudo da prevalência de lesöes bucais em pacientes portadores de paracoccidioidomicose na regiäo de Campo Grande - Mato Grosso do Sul / Study on the prevalence of oral lesions in paracoccidioidomycosis patients in the region of Campo Grande - Mato Grosso do Sul

A paracoccidioidomicose é uma doença endêmica no Brasil de caráter sistêmico, cujo conhecimento é de interesse para a Odontologia, pela grande incidência de lesöes na cavidade bucal, onde, muitas vezes, pode ser observada a primeira manifestaçäo da doença. A regiäo de Campo Grande, no Mato Grosso do Sul, é considerada endêmica e, como a maioria dos pacientes é atendida no Hospital Universitário da UFMS foi realizado o levantamento de 189 prontuários de pacientes com diagnóstico positivo para a doença. Esse levantamento compreendeu um período de 10 anos (1989-1998) e teve a finalidade de estudar a presença de lesöes na cavidade bucal. A análise dos dados obtidos demonstrou maior incidência no gênero masculino (91 por cento). Noventa e oito pacientes (51,9 por cento) eram trabalhadores rurais, com prevalêcia na faixa etária superior a 50 anos. Observamos, ainda, significativa incidência de lesöes bucais - 122 em 189 casos (64,55 por cento) - o que destaca a importância do cirurgiäo dentista no diagnóstico dessa patologia