Cryopreservation of seeds of Neonotonia wightii Wight and Arn: a strategy for conservation, dormancy breaking and preservation of nutritional status.

BACKGROUND: N. wightii (Leguminosae) is valued as a cover crop and as a potential source of protein in food insecure countries. However, plantlet establishment is limited by physical dormancy. Our previous work has shown that exposure of N. wightii seeds to cryogenic temperatures is able to overcome physical dormancy. OBJECTIVE: The current study is an extension of that work where the field performance and nutritional composition of plants regenerated from N. wightii seeds was investigated. RESULTS: It was evident that plants regenerated from cryopreserved seeds displayed faster growth rates than those from control seeds. In addition, cryopreservation did not alter the nutritional profile of plants produced from cryo-stored seeds. CONCLUSION: Collectively, the results indicate that cryopreservation serves as a suitable strategy for the preservation of seeds of N. wightii with the added benefit of also serving as a dormancy breaking mechanism upon retrieval from cryogenic temperatures. Doi.org/10.54680/fr23510110712.

Caries dental en preescolares: estudio transversal de base poblacional en Montevideo, Uruguay

Prevalencia/extensión/severidad de caries, registrada según ICDAS, en niños de 5 años de Montevideo-Uruguay. Estudio transversal de base poblacional de 614 niños de escuelas públicas/privadas. Se evaluó la asociación entre variables predictoras, prevalencia/extensión de caries mediante regresión de Poisson. Prevalencia 70,9%(95%IC=66,40-75,50) y extensión 10,0(95%IC=8,70-11,30) superficies. La prevalencia mostró diferencias significativas entre categorías de escuelas, SEC, nivel educativo de la madre (NEM) y alimentación, y la extensión entre el tipo de escuelas, SEC, NEM, frecuencia de cepillado y de consumo de refrescos. Niños con SEC bajo/medio (RP=1,55;IC95%=1,15-2,08 y PR=1,50;IC95%=1,12-2,01 respectivamente), NEM primario (RP=1,35;IC95%=1,11-1,65), de escuela pública (RP=1,21;95%IC=1,08-1,36) y que consumían gaseosa diariamente (RP=1,20;95%IC=1,01-1,43) mostraron significancia en el modelo no-ajustado. Preescolares con SEC bajo/medio (RR=1,78;IC95%=1,01-3,11 y RR=1,66;IC95%=0,99-2,79 respectivamente), NEM primario (RR=1,86; IC95%=1,21-2,87); bajo SEC (RR=1.78;IC95%=1.01-3.11) y consumo diario de refrescos (RR=1.79;IC95%=1.20-2.68) tenían mayor probabilidad de caries en el análisis ajustado. La prevalencia/extensión de caries fue alta, asociándose con variables sociodemográficas/comportamentales.

Exposure of maize seeds to liquid nitrogen modifies the morphology and hormonal response of young plants.

BACKGROUND: Cryopreservation currently represents the most suitable strategy for the long-term conservation of plant germplasm. While much effort has focused on the development of protocols to enable successful cryostorage, there are few, if any reports, that consider the effect of cryogenic temperatures on the phytohormone status of the seed and developing seedlings. OBJECTIVE: To investigate the effect of cryopreservation on external seed coat features as well as levels of indole-3-acetic acid (IAA), abscisic acid (ABA) and 1-aminocyclopropane-1-carboxylic acid (ACC) in maize. MATERIALS AND METHODS: Two groups of seeds at 6% moisture content were compared: one was maintained at 4 degree C (control) while the other was exposed to LN within cryo-vials. RESULTS: Seeds exposed to cryogenic temperatures were characterized by the presence of large cracks in the seed coat compared with control seeds. Cryogenic exposure also resulted in a reduction in biomass and plant height. Results from the phytohormone analysis showed an initial reduction in the levels of IAA, ABA and ACC after 7 days of growth followed by sharp increase in levels relative to the control by 14 days. Whilst the roles of ABA and ethylene (and by extension, its precursor ACC) are well studied as stress response molecules, much less is known about the potentially vital role of auxins in regulating plant growth under conditions of low temperature stress. CONCLUSION: It is postulated that the interaction of all three hormones modulate crosstalk between various stress responses and recovery pathways to ameliorate the damage caused by freezing stress and enable plant survival. Given the dearth of information on phytohormones in cryobiology, more studies are needed to fully elucidate these relationships in the context of freezing stress caused by liquid nitrogen. Doi.org/10.54680/fr23610110612.

Desgaste erosivo en preescolares de 5 años de Montevideo­Uruguay: primer estudio poblacional / Erosive tooth wear in 5 -year- old preschool children of Montevideo­Uruguay: first population study / Desgaste erosivo em preescolares de 5 anos de MontevideoUruguai: primer estudo populacional

Objetivo: determinar prevalencia, extensión, severidad y distribución del desgaste erosivo (DE) en preescolares de Montevideo. Metodología: estudio transversal de base poblacional, muestra representativa de centros educativos públicos y privados. Fueron indagados aspectos sociodemográficos, biológicos y de comportamiento con un cuestionario auto-reportado por padres/responsables. Los exámenes fueron realizados por dos operadores Kappa ≥ 0,7. DE fue registrado con el índice O´Brien modificado, reportándose porcentaje y promedio; intervalo de confianza (IC) 95%. Se realizaron análisis de asociación con sexo y nivel socioeconómico. Resultados: se examinaron 614 preescolares. Prevalencia: 57,6% (IC95%: 52,7-62,5). Extensión: 4,8 (IC95%: 4,3-5,3). DE severo: 8,2% (IC95%: 5,5-10,9) Las superficies más afectadas fueron palatino de incisivos superiores. Los preescolares de nivel socioeconómico alto presentaron mayor DE que los de nivel bajo; 73,1% (IC95%:61,9-84,2) y 48,4% (IC95%:39,2-57,7) respectivamente (p≤0,01). Conclusiones: la prevalencia y extensión del DE fue alta. Estos datos pueden contribuir en la modificación de medidas que apunten a controlar la prevalencia de DE.

Aims: assess the prevalence, extent,severity, and distribution of erosive tooth wear (ETW) in preschoolers of Montevideo. Methods: cross-sectional populationbased study of representative sample of public and private educational centers. Sociodemographic, biological, and behavioral aspects were investigated with a self-reported questionnaire to parents /guardians. The examinations were performed by two examiners (Kappa ≥ 0.7). The ETW was registered with modified O´Brien index, reported in percentage and average, confidence interval (CI) 95%. Analysis of association with sex and socioeconomic level were carried out.Results: 614 preschoolers were examined. Prevalence: 57.6% [95%CI=52.7-62.5]. Severe ETW: 8.2% [95%CI 5.5-10.9]. ETW extension: 4.8 [95%CI=4.3-5.3]. The most affected surfaces were palatal upper incisors. Preschoolers of high socioeconomic level presented higher ETW than those of low level; 73.1% (95% CI: 61.9-84.2) and 48.4% (95% CI: 39.2-57.7) respectively (p≤0.01). Conclusion: ETW prevalence and extent was high. These data can contribute to the modification of measures that aim to control ETW prevalence.

Objetivo: determinar prevalência, extensão, severidade e distribuição do desgaste erosivo (DE) em pré-escolares de Montevidéu. Metodologia: estudo transversal de base populacional, amostra representativa de centros educacionais públicos e privados. Aspetos sociodemográficos, biológicos e comportamentais foram investigados por meio de questionário autorreferência pelos pais/responsáveis. Os exames foram realizados por dois operadores Kappa ≥ 0,7. DE foi registado com o Índice O´Brien modificado, relatando porcentagem e média; intervalo de confiança (IC) 95%. Foi realizada análise de associação com sexo e nível socioeconômico. Resultados: 614 pré-escolares foram examinados. Prevalência: 57,6% (IC95%: 52,7-62,5). Extensão: 4,8 (IC 95%: 4,3-5,3). DE grave: 8,2% (IC 95%: 5,5-10,9). As superfícies mais afetadas foram palatinas dos incisivos superiores. Pré-escolares de alto nível socioeconômico apresentaram maior DE que os de baixo nível; 73,1% (IC 95%: 61,9-84,2) e 48,4% (IC 95%: 39,2-57,7) respetivamente (p≤0,01). Conclusões: a prevalência e extensão da DE foi alta. Esses dados podem contribuir em la modificação de medidas que visam controlar a prevalência de DE.

Exposure of Teramnus labialis (L.F.) Spreng Seeds to Liquid Nitrogen Does Not Affect Nutritional Status of Field Grown Adult Plants.

BACKGROUND: Teramnus labialis (L.f.) Spreng is a potentially important legume species, and can be used as an animal feed and to enhance soil physicochemical characteristics. Despite the biological and agricultural importance, the low availability of seeds, their small size and the low percentage germination limit their large-scale use by farmers. We previously reported a method to cryopreserve seeds of T. labialis which also allowed for the breaking of seed dormancy. OBJECTIVE: The current study reports on the nutritional status of 5 month old field grown plants regenerated from cryostored and control seeds. MATERIALS AND METHODS: Biomass (fresh and dry mass of leaves and stems) and contents of ash, neutral detergent fiber, acid detergent fiber, lignin, cellulose, crude protein, P, Ca, Mg and K were measured. RESULTS: Seeds germinated and emerged faster following immersion in liquid nitrogen (LN) which was supported by quantitative evaluations of fresh and dry weights per m2. However, the ratio of leaf:stem mass were not altered by seed exposure to LN. CONCLUSION: The results showed that exposure of seeds to cryogenic temperatures did not alter the nutritional composition of regenerated plants.

Seed Cryostorage Enhances Subsequent Plant Productivity in the Forage Species Teramnus Labialis (L.F.) Spreng.

BACKGROUND: Teramnus labialis is an herbaceous legume that serves as a source of carbohydrates and proteins for animals and humans, and is valued for its nitrogen contribution to soil. The benefits of this species are, however, limited by low seed availability, small seed size and low in situ seed germination levels, due to physical dormancy. Cryostorage has been shown to be beneficial for both seed storage and breaking physical dormancy in seeds of various species. However, its potential effects on subsequent seedling emergence, plant growth and seed production need to be studied before large-scale implementation for T. labialis. OBJECTIVE: To record agricultural traits of T. labialis after seed exposure to liquid nitrogen. MATERIALS AND METHODS: Seeds were maintained at 5 degree C (control) or stored in LN before sowing. Seedling emergence percentage and traits related to plant growth and seed production were evaluated for 6 months. RESULTS: Except for seed weight, all traits differed significantly between seedlings generated from cryostored and control seeds. Except for pod number, seedling emergence and plant growth traits were enhanced by cryostorage to a greater extent than seed production traits. Cryostorage resulted in cracks and breaks in the seed coat which were absent in control seeds (scanning electron microscopy), and in breaking physical dormancy may have facilitated more rapid seedling emergence than for control seeds. CONCLUSION: Seed cryostorage enhances subsequent plant productivity in terms of growth and to a lesser extent seed production in Teramnus labialis, validating its use for commercial growth of this species.

Fibroblasto: célula fundamental en la salud y en la enfermedad periodontal / Fibroblast: essential cell in health and periodontal disease

Las células mesenquimáticas son precursoras de un variado grupo de células del tejido conjuntivo, que incluyen a las células endoteliales, células del músculo liso, pericitos, condroblastos, adipocitos, osteoblastos, odontoblastos y fibroblastos. Los fibroblastos son una población heterogénea de células que se encuentran en numerosos tejidos. Además, es el tipo de célula predominante del estroma en los tejidos conjuntivos blandos. Estas células y sus productos de la matriz extracelular, es decir, fibras y sustancia fundamental amorfa desempeñan papeles fundamentales en el mantenimiento de la integridad estructural de los tejidos conjuntivos. Aun cuando los fibroblastos son fenotípicamente estables, presentan subpoblaciones heterogéneas, que regulan la forma y la función del tejido. La distribución en los tejidos y la proporción relativa de estas subpoblaciones de fibroblastos tienen un impacto considerable en la regulación de la función del tejido conjuntivo en la salud y la enfermedad.El propósito de esta revisión fue actualizar el conocimiento acerca de los fibroblastos proporcionando información con respecto a la heterogeneidad y versatibilidad de estas células, reconociendo su participación en la inmunidad, la regeneración y la remodelación de tejidos, así como, su más reciente significación como célula madre pluripotente inducida...

Mesenchymal cells are precursors to a diverse group of connective tissue cells, including endothelial cells, smooth muscle cells, pericytes, chondroblasts, adipocytes, osteoblasts, odontoblasts, and fibroblasts. Fibroblasts are a heterogeneous population of cells that are found in many tissues. Moreover, is the predominant type of stromal cell in soft connective tissues. These cells and their extracellular matrix products, fibers and amorphous ground substance play key roles in maintaining the structural integrity of connective tissues. Even when the fibroblasts are phenotypically stable, have subpopulations heterogeneous regulating the shape and function of the tissue. The tissue distribution and the relative proportion of these subpopulations of fibroblasts have a considerable impact on the regulation of connective tissue function in health and disease.The purpose of this review was to update the knowledge of fibroblasts by providing information regarding the heterogeneity and versatility of these cells, recognizing their involvement in immunity, regeneration and tissue remodeling, as well as its newest significance as a cell induced pluripotent stem...

Tratamiento de la lesión temprana de caries y su efecto potencializador de salud: un desafío a largo plazo / Early childhood caries treated with an educational, preventive and therapeutic approach

En este trabajo se presenta la evolución de un paciente con caries temprana de la infancia, con la implementación de un tratamiento educativo, preventivo y terapéutico. Esta enfermedad, frecuente en pacientes pediátricos, se caracteriza por presentar varias superficies cariadas, algunas veces pérdida dentaria parcial o total y repercusiones orales como dolor, dificultades en la alimentación, el habla y el aprendizaje, pérdida de la longitud del arco dental, así como alteraciones a nivel de la salud general y sicológica del niño. El paciente que se presenta, un niño de 10 años de edad, comenzó su atención odontológica a los 3 años y 5 meses, presentando múltiples cavidades cariosas activas, avulsión traumática del 52, IHOS = 2. Hay relación directa entre una pobre higiene bucal y una dieta altamente cariogénica y frecuente. Los estudios microbiológicos iniciales mostraron un elevado recuento de Streptococcus mutans y Lactobacilos. El plan de tratamiento comenzó con medidas de educación para la salud y control de la infección y del medio, así como el control químico del biofilm, obteniéndose la reconversión del riesgo. En los controles anuales se aplicaron los procedimientos preventivos pertinentes.