[Bibliographic review of the efficacy of platelet-rich plasma treatment in lumbar disc herniation]. / Revisión bibliográfica de la eficacia del tratamiento con plasma rico en plaquetas en hernia de disco lumbar.

Platelet-rich plasma (PRP) is an autologous blood product containing growth factors and proteins, widely employed in the clinical setting for tissue repair. Robust evidence in basic science literature has facilitated clinical research involving PRP for patients with disc disease and lumbar pain. Degenerative disc disease (DDD) has been identified as a significant contributor to lower back pain, with approximately 40% of patients under 30 and 90% of those over 50 experiencing lumbar pain showing MRI findings consistent with degenerative changes in intervertebral discs. Regenerative medicine within the disc has primarily been studied in patients with chronic, untreatable lumbar pain. Objective: to understand the available evidence regarding the efficacy of PRP in lumbar disc herniation. By understanding the scientific evidence supporting PRP as a lumbar disc herniation treatment, a research project can be developed, providing the theoretical foundation for implementing this therapy in the Mexican population. A search was conducted using PUBMED, ClinicalKey (Elsevier), Medscape, Science Direct, and Google Scholar databases. Conclusions: despite promising results in several studies on intradiscal PRP injection, small sample sizes and non-standardized graft preparation procedures have hindered these research efforts.

El plasma rico en plaquetas (PRP) es un producto sanguíneo autólogo que contiene factores de crecimiento y proteínas y se ha utilizado en todo el entorno clínico para la reparación de tejidos. La fuerte evidencia en la literatura de ciencias básicas ha permitido la investigación clínica que involucra PRP para pacientes con enfermedad del disco y dolor lumbar. La enfermedad degenerativa del disco (DDD) se ha establecido como un importante contribuyente a la causa del dolor lumbar: aproximadamente el 40% de los pacientes menores de 30 años y el 90% de los pacientes mayores de 50 años que tienen dolor lumbar también muestran hallazgos de imágenes de resonancia magnética (IRM) que son consistentes con cambios degenerativos dentro de los discos intervertebrales. La medicina regenerativa intradiscal se ha estudiado principalmente en pacientes con dolor lumbar crónico intratable. Objetivo: conocer la evidencia disponible sobre la eficacia del PRP en hernias de disco lumbar. Al conocer la evidencia científica disponible del PRP como tratamiento de hernia discal lumbar se podrá desarrollar un proyecto de investigación, lo cual sustentará las bases teóricas para realizar esta terapia en la población mexicana. Se realizó búsqueda en base de datos PUBMED, ClinicalKey (Elsevier), Medscape, Science Direct, Google Scholar. Conclusiones: aunque varias investigaciones han arrojado resultados prometedores con respecto a la inyección intradiscal de PRP los tamaños de muestra pequeños y los procedimientos de preparación de injertos no estandarizados obstaculizaron estos esfuerzos de investigación.

A Brassica oleracea gene expressed in a variety-specific manner may encode a novel plant transmembrane receptor.

The species Brassica oleracea includes several agricultural varieties characterized by the proliferation of different types of meristems. Using a combination of subtractive hybridization and PCR (polymerase chain reaction) techniques we have identified several genes which are expressed in the reproductive meristems of the cauliflower curd (B. oleracea var. botrytis) but not in the vegetative meristems of Brussels sprouts (B. oleracea var. gemmifera) axillary buds. One of the cloned genes, termed CCE1 (CAULIFLOWER CURD EXPRESSION 1) shows specific expression in the botrytis variety. Preferential expression takes place in this variety in the meristems of the curd and in the stem throughout the vegetative and reproductive stages of plant growth. CCE1 transcripts are not detected in any of the organs of other B. oleracea varieties analyzed. Based on the nucleotide sequence of a cDNA encompassing the complete coding region, we predict that this gene encodes a transmembrane protein, with three transmembrane domains. The deduced amino acid sequence includes motifs conserved in G-protein-coupled receptors (GPCRs) from yeast and animal species. Our results suggest that the cloned gene encodes a protein belonging to a new, so far unidentified, family of transmembrane receptors in plants. The expression pattern of the gene suggests that the receptor may be involved in the control of meristem development/arrest that takes place in cauliflower.

Identification of genes specifically expressed in cauliflower reproductive meristems. Molecular characterization of BoREM1.

Using the meristems of the cauliflower curd as a source of tissue and a series of subtractive hybridizations and amplification reactions, we have constructed a cDNA library highly enriched in cDNAs expressed in reproductive meristems. The analysis of a sample of 250 clones from this library identified 22 cDNA clones corresponding to genes specifically expressed in these cauliflower meristems. Apart from two clones that corresponded to APETALA1, and two other ones showing similarity to different aminoacyl-tRNA synthetases, the remaining clones showed no similarity to any sequence in the databases and may correspond to novel genes. One of these clones, BoREM1, was further characterized and found to correspond to a gene encoding a protein with features of regulatory proteins that follows a expression pattern very similar to the LEAFY transcripts.

Estandarización del método de obtención de concentrados plaquetarios en bolsaplasticas

Se estudiaron tres variables para obtener los plasmas ricos en plaquetas y para preparar los concentrados de plaquetas en bolsas plásticas, en las cuales se hacen variaciones de tiempo y velocidades, respectivamente. Se selecionó en cada caso la de mejor rendimiento en nuestras condiciones (2 500 rpm 3min y a 4 000 rpm 10 min), y se estudió, además, la respuesta al estrés hipotónico de lo CP, una vez estandarizado el método de su obtención. Se halló el rango normal de los mismos (47,65-93,7 por ciento), el cual se usa para controlar la calidad en nuestro Banco de Sangre

Oncogene involvement in tumor regression: H-ras activation in the rabbit keratoacanthoma model.

Activated H-ras genes are present in a number of skin tumors induced in animals by carcinogen treatment. The involvement of the ras oncogenes in tumorigenesis was investigated in keratoacanthomas, benign and self-regressing tumors, as well as malignant squamous cell carcinomas. Both tumors were induced in rabbit ears by repeated applications of 7,12 dimethylbenz(a)anthracene (DMBA). The rabbit H-ras gene was cloned and sequenced. PCR analysis revealed that approximately 82% of the keratoacanthoma DNAs contained an A:T to T:A transversion in codon 61. The relative levels of H-ras transcript were increased in keratoacanthomas compared to normal skin and the activated allele was expressed in tumors, even during the regressing phase. Although a G:C to A:T mutation in codon 12 of the H-ras and an activated N-ras gene were found in two squamous cell carcinomas, the frequency of H-ras activation in codon 61 was much lower (40%) in the malignant tumours induced by the same carcinogen treatment. Therefore, DMBA induced at least two types of genetic lesions in this system: H-ras activation, present in most regressing keratoacanthomas, and activation of other unidentified oncogenes which may result in the development of malignant tumors. Our observations indicate that expression of an activated H-ras gene, in this system, is neither sufficient to induce a malignant phenotype nor even capable of maintaining the growth of a benign tumor and suggest that it could be involved in tumor regression.

Post-transcriptional regulation of methionine content in maize kernels.

Message levels for a methionine-rich 10 kDa zein were determined in three inbred lines of maize and their reciprocal crosses at various stages during endosperm development. Inbred line BSSS-53, which overexpresses the 10 kDa protein in mature kernels, was shown to have higher mRNA levels in developing endosperm, as compared to inbred lines W23 and W64A. Differences in mRNA levels could not be explained by differences in transcription rate of the 10 kDa zein gene, indicating differential post-transcriptional regulation of this storage protein in the different inbred lines analyzed. Among progeny segregating for the BSSS-53 allele of the 10 kDa zein structural gene Zps10/(22), mRNA levels are independent of Zps10/(22) segregation, indicating that post-transcriptional regulation of mRNA levels takes place via a trans-acting mechanism. In the same progeny, mRNA levels are also independent of allelic segregation of the regulatory locus Zpr10/(22). Thus, the trans-acting factor encoded by Zpr10/(22) determines accumulation of 10 kDa zein at a translational or post-translational step. Multiple trans-acting factors are therefore involved in post-transcriptional regulation of the methionine-rich 10 kDa zein.

Cloning of a full-length complementary DNA for an Artemia salina glycine-rich protein. Structural relationship with RNA binding proteins.

Overlapping cDNAs have been isolated containing all the coding sequences for Artemia salina protein GRP33, a glycine-rich protein (16.6 mol % glycine), with a molecular weight of 32,992. GRP33 is closely related to HD40, the major protein component of Artemia heterogeneous nuclear ribonucleoprotein particles, and shares certain characteristics with other RNA binding proteins. The C-terminal region (123 amino acids) contains 39 glycine residues. This region has multiple arginine residues flanked by glycines, resembling the glycine-dimethylarginine clusters present in other RNA binding proteins. Secondary structure predictions for the protein reveal two distinct domains: a hydrophilic C-terminal domain with an extended conformation and a larger N-terminal domain with a number of alpha-helices and beta-sheets.

Cloning of cDNA sequences for an Artemia salina hnRNP protein: evidence for conservation through evolution.

A cDNA clone was isolated for Artemia salina protein HD40, a component of heterogenous nuclear ribonucleoproteins. Enriched Artemia 15S poly(A)+ RNA was used as a template and double-stranded cDNA sequences were inserted into the Pst I restriction endonuclease site of E. coli plasmid pBR322. Recombinant colonies were analyzed by positive hybrid selection of poly(A)+ RNA that directs the synthesis of protein HD40 in an in vitro assay. In vitro translation of the mRNA selected by recombinant clone 87HD yields a protein that is immunoprecipitated by anti-HD40 antibodies and that comigrates with authentic HD40 on gel electrophoresis. Partial proteolysis of protein HD40 and the in vitro translated product selected by clone 87HD produces the same peptide patterns. The size of the cloned insert is about 820 bp. The length of HD40 mRNA as determined by Northern blot analysis, is about 1500 nucleotides. Southern blot analysis performed with DNA of different species (plant, avian, mammal) shows cross-hybridizing bands when probed with clone 87HD DNA suggesting that the HD40 gene is evolutionarily conserved.