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1.
Eur Spine J ; 2024 May 22.
Artículo en Inglés | MEDLINE | ID: mdl-38775821

RESUMEN

PURPOSE: Mebos, a traditional South Africa confection consisting of dried, pulped, and sugared apricots, is rich in fibre and vitamins, but also contains salicylic acid, flavonoids, and citric acid. We report a case of postoperative surgical site bleeding in a healthy patient who consumed approximately 2 kg of mebos per day prior to his elective spinal surgery. METHODS: The clinical course of a previously healthy 54-year-old male patient with cauda equina syndrome secondary to lumbar spinal stenosis who underwent surgical intervention with subsequent bleeding into the surgical site is discussed. The cause was investigated through biochemical analysis, thromboelastometry (ROTEM®) and mass and absorption spectrometry were applied to assess flavonoid, citric acid, and salicylic acid content. RESULTS: ROTEM® revealed an abnormal clotting profile with an increased clot forming time, suggesting intrinsic coagulopathy. Mass and absorption spectrometry revealed a high total flavonoid content as well as citric acid concentration in the mebos. Salicylic acid was at detection limits of the instrument. CONCLUSION: Results highlighted the effect of flavonoids and citric acid and therefore explain the abnormal clotting profile in this patient. Inhibition of coagulation prior to elective surgery is a known contraindication and may pose great risks in spinal surgery. In the present report, we demonstrated an association between inhibition of coagulation and an excess of the flavonoids content and citric acid concentration in mebos consumed in the days prior to elective spinal surgery.

2.
J Exp Bot ; 66(17): 5337-49, 2015 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-26071531

RESUMEN

Lateral organ boundary formation is highly regulated by transcription factors and hormones such as auxins and brassinosteroids. However, in contrast to many other developmental processes in plants, no role for signalling peptides in the regulation of this process has been reported yet. The first characterization of the secreted cysteine-rich TAXIMIN (TAX) signalling peptides in Arabidopsis is presented here. TAX1 overexpression resulted in minor alterations in the primary shoot and root metabolome, abnormal fruit morphology, and fusion of the base of cauline leaves to stems forming a decurrent leaf attachment. The phenotypes at the paraclade junction match TAX1 promoter activity in this region and are similar to loss of LATERAL ORGAN FUSION (LOF) transcription factor function. Nevertheless, TAX1 expression was unchanged in lof1lof2 paraclade junctions and, conversely, LOF gene expression was unchanged in TAX1 overexpressing plants, suggesting TAX1 may act independently. This study identifies TAX1 as the first plant signalling peptide influencing lateral organ separation and implicates the existence of a peptide signal cascade regulating this process in Arabidopsis.


Asunto(s)
Proteínas de Arabidopsis/genética , Arabidopsis/crecimiento & desarrollo , Arabidopsis/genética , Regulación de la Expresión Génica de las Plantas , Péptidos y Proteínas de Señalización Intracelular/genética , Secuencia de Aminoácidos , Arabidopsis/metabolismo , Proteínas de Arabidopsis/química , Proteínas de Arabidopsis/metabolismo , Péptidos y Proteínas de Señalización Intracelular/química , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Meristema/genética , Meristema/crecimiento & desarrollo , Meristema/metabolismo , Péptidos/química , Péptidos/genética , Péptidos/metabolismo , Hojas de la Planta/genética , Hojas de la Planta/crecimiento & desarrollo , Hojas de la Planta/metabolismo , Tallos de la Planta/genética , Tallos de la Planta/crecimiento & desarrollo , Tallos de la Planta/metabolismo , Señales de Clasificación de Proteína , Alineación de Secuencia
3.
Anal Chim Acta ; 1191: 339284, 2022 Jan 25.
Artículo en Inglés | MEDLINE | ID: mdl-35033263

RESUMEN

Honeybush is an indigenous herbal tea highly valued for its aroma, flavour and medicinal properties. It is protected as Geographical Indication (GI) since it is produced from a number of Cyclopia species that are endemic to South Africa. Most commonly used for honeybush tea production are C. intermedia, C. subternata and C. genistoides, differing slightly, but distinctly in flavour. Demand for species-specific honeybush tea instead of mixtures have increased, meriting a strategy for authentication of C. intermedia, C. subternata and C. genistoides. Samples of these three species were analysed, using hyperspectral imaging (HSI) in the near-infrared spectral range. The data were pre-processed and used for class-modelling, a general approach well suited for authentication purposes. Unfortunately, since the HSI data of Cyclopia species studied are very similar, the classification results obtained with individual class-models are unsatisfactory, e.g., class-models constructed for C. genistoides and C. subternata yielded correct classification rate (CCR) values of 76.4 and 83.1%, respectively. On the other hand, discriminant modelling, which is another type of classification technique, led to good classification outcomes (CCR 98.9%). However, the classical discriminant model cannot be applied for authentication purposes since it always assigns a new sample to one of the classes studied, even if in reality, it belongs to none of them. Counterfeits or non-representative samples would be incorrectly assigned by the discriminant model to one of the authentic classes. Therefore, in this study, a two-step authentication of overlapping classes is proposed, which combines the advantages of class-modelling and discriminant methods. When applied to the authentication of Cyclopia species studied, the two-step approach yielded a CCR of 97.4%, which is a significant improvement compared to results obtained with the individual class-models. The proposed approach is general and can be applied when classes studied are very similar, and individual class-models lead to unsatisfactory results.


Asunto(s)
Odorantes , Extractos Vegetales , Gusto
4.
Plant Signal Behav ; 11(4): e1143998, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-26967827

RESUMEN

Peptide signaling in plants is involved in regulating development, (1,2) ensuring cross pollination through initiation of self-incompatibility (4) and assisting with recognition of beneficial (nitrogen fixing bacteria (5)) or unfavorable organisms (pathogens (6) or herbivores (7)). Peptides function to help plants to respond to a changing environment and improve their chances of survival. Constitutive expression of the gene encoding a novel cysteine rich peptide TAXIMIN1 (TAX1) resulted in fusion of lateral organs and in abnormal fruit morphology. TAX1 signaling functions independently from transcription factors known to play a role in this process such as LATERAL ORGAN FUSION1 (LOF1). Here, we report that the TAX1 promoter is not induced by the LOF1 transcription factor and that the TAX1 peptide neither interferes with transcriptional activation by LOF1.1 or transcriptional repression by LOF1.2. Furthermore, we found that TAX1 overexpressing lines were hypersensitive to continuous light, which may be reflected by a decreased accumulation of the UV-B protecting compound sinapoyl-malate. Finally, adding the antibiotic cefotaxime to the medium surprisingly countered the light hypersensitivity phenotype of TAX1 overexpressing seedlings.


Asunto(s)
Antibacterianos/farmacología , Proteínas de Arabidopsis/metabolismo , Arabidopsis/fisiología , Arabidopsis/efectos de la radiación , Cefotaxima/farmacología , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Luz , Malatos/metabolismo , Fenilpropionatos/metabolismo , Estrés Fisiológico/efectos de la radiación , Arabidopsis/efectos de los fármacos , Plantas Modificadas Genéticamente
5.
Methods Mol Biol ; 1011: 287-303, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-23616005

RESUMEN

cDNA-AFLP is a commonly used, robust, and reproducible tool for genome-wide expression analysis in any species, without requirement of prior sequence knowledge. Quantitative expression data are generated by gel-based visualization of cDNA-AFLP fingerprints obtained by selective PCR amplification of subsets of restriction fragments from a double-stranded cDNA template. Differences in gene expression levels across the samples are reflected in different band intensities on the high-resolution polyacrylamide gels. The differentially expressed genes can be identified by direct sequencing of re-amplified cDNA-AFLP tags purified from the gels. The cDNA-AFLP technique is especially useful for profiling of transcriptional responses of jasmonate-treated plants or plant (tissue) cultures and the discovery of jasmonate-responsive genes.


Asunto(s)
Ciclopentanos/farmacología , ADN Complementario/genética , Perfilación de la Expresión Génica , Oxilipinas/farmacología , Reguladores del Crecimiento de las Plantas/farmacología , Análisis del Polimorfismo de Longitud de Fragmentos Amplificados , Técnicas de Cultivo , Expresión Génica , Genoma de Planta , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Reacción en Cadena de la Polimerasa
6.
J Plant Physiol ; 167(17): 1521-4, 2010 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-20674074

RESUMEN

Environmental stresses can significantly alter the synthesis of both primary and secondary metabolites, resulting in medicinal plants with unpredictable biological activity. Here, in vitro shoot cultures of the medicinal plant Sutherlandia frutescens were used to study the impact of three abiotic stresses (nitrogen availability, drought and salinity), primarily on l-canavanine synthesis. This compound, a non-protein amino acid, is amongst those metabolites linked to the health benefits of Sutherlandia extracts. Nitrogen supplied to microplants positively correlated with canavanine levels, exhibited by a fourfold reduction when nitrates provided were halved. Although the biomass generated was lowered under these conditions, a higher capacity for rooting (52%) in comparison to the controls (37%) became evident. Only a small increase of the canavanine content in microplants growing on 100mM NaCl medium was detected, indicating that salinity stress was not a major limitation on cavanine production, but that it played more of a role in vitro on plantlet morphogenesis. Similarly, PEG as a supplement had little to no effect on canavanine synthesis. We conclude that a deeper understanding of the nutritional requirements for the agricultural crop management of S. frutescens, which serves the herbal products industry, is needed.


Asunto(s)
Canavanina/biosíntesis , Fabaceae/crecimiento & desarrollo , Nitrógeno/farmacología , Brotes de la Planta/efectos de los fármacos , Brotes de la Planta/fisiología , Regeneración/efectos de los fármacos , Estrés Fisiológico/efectos de los fármacos , Biomasa , Fabaceae/efectos de los fármacos , Polietilenglicoles/farmacología , Cloruro de Sodio/farmacología , Técnicas de Cultivo de Tejidos
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