RESUMO
Alfalfa (Medicago sativa L.) roots contain large quantities of beta-amylase, but little is known about its role in vivo. We studied this by isolating a beta-amylase cDNA and by examining signals that affect its expression. The beta-amylase cDNA encoded a 55.95-kD polypeptide with a deduced amino acid sequence showing high similarity to other plant beta-amylases. Starch concentrations, beta-amylase activities, and beta-amylase mRNA levels were measured in roots of alfalfa after defoliation, in suspension-cultured cells incubated in sucrose-rich or -deprived media, and in roots of cold-acclimated germ plasms. Starch levels, beta-amylase activities, and beta-amylase transcripts were reduced significantly in roots of defoliated plants and in sucrose-deprived cell cultures. beta-Amylase transcript was high in roots of intact plants but could not be detected 2 to 8 d after defoliation. beta-Amylase transcript levels increased in roots between September and October and then declined 10-fold in November and December after shoots were killed by frost. Alfalfa roots contain greater beta-amylase transcript levels compared with roots of sweetclover (Melilotus officinalis L.), red clover (Trifolium pratense L.), and birdsfoot trefoil (Lotus corniculatus L.). Southern analysis indicated that beta-amylase is present as a multigene family in alfalfa. Our results show no clear association between beta-amylase activity or transcript abundance and starch hydrolysis in alfalfa roots. The great abundance of beta-amylase and its unexpected patterns of gene expression and protein accumulation support our current belief that this protein serves a storage function in roots of this perennial species.
Assuntos
Medicago sativa/enzimologia , Medicago sativa/genética , beta-Amilase/genética , beta-Amilase/metabolismo , Sequência de Aminoácidos , Sequência de Bases , Primers do DNA/genética , DNA Complementar/genética , DNA de Plantas/genética , Regulação Enzimológica da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Genes de Plantas , Dados de Sequência Molecular , Família Multigênica , Raízes de Plantas/enzimologia , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , RNA de Plantas/genética , RNA de Plantas/metabolismo , Homologia de Sequência de Aminoácidos , Amido/metabolismo , Sacarose/metabolismoRESUMO
The low-temperature (2 degrees C)-specific wheat cDNA, pTACR7, represents a gene designated tacr7 from hard red winter wheat (HRWW; Triticum aestivum L. cv. Winoka). The term low-temperature-specific (LTS) is used because tacr7 is not induced by ABA or stresses such as salt, dehydration, and heat. pTACR7 was isolated by RT-PCR with mRNA from wheat crown tissue, the oligonucleotide primers derived from the barley cognate pHVCR8 (GenBank accession number L28091). Based on the deduced amino acid sequence, TACR7 is highly hydrophobic, with a single transmembrane domain and an amino acid bias for leucine (19%). Thus, the encoded protein TACR7 is unique among low-temperature-regulated wheat proteins described in the literature. Analysis of steady-state levels of tacr7 transcripts (630 nt) showed accumulation in wheat seedlings, crown tissue, and callus cultures after transfer from control (25 degrees C) to low temperature (2 degrees C). No detectable transcripts were observed by northern blot hybridization with pTACR7 probe from seedling or callus treated with ABA, salt, dehydration, or heat stress. tacr7 transcripts accumulated during 2 degrees C exposure to a greater amount in a freeze-resistant HRWW (FR; SDmut 16029) than in a freeze-susceptible HRWW (FS; SDmut 16169) crown tissue, with the largest difference between genotypes being 30% +/- 3% at 3 weeks.
Assuntos
Regulação da Expressão Gênica de Plantas , Genes de Plantas , Proteínas de Plantas/genética , Triticum/genética , Ácido Abscísico/farmacologia , Sequência de Aminoácidos , Células Cultivadas , DNA Complementar/genética , Congelamento , Dados de Sequência Molecular , Mutação , Proteínas de Plantas/biossíntese , Brotos de Planta/citologia , Brotos de Planta/genética , RNA Mensageiro/biossíntese , RNA Mensageiro/genética , RNA de Plantas/biossíntese , RNA de Plantas/genética , Estações do Ano , Homologia de Sequência de Aminoácidos , Especificidade da Espécie , Triticum/citologiaRESUMO
Thirty one patients with clinical and sonographic diagnosis of ovarian tumor were studied prospectively, with Transvaginal Color Doppler. There were 24 benign and 7 malignant tumors (4 stage I borderline, I stage IA cistoadenocarcinoma and 2 adenocarcinoma stage III). Six malignant tumors had resistance indexes (IR) from 0.17 to 0.55. In one borderline no vascular signal was obtained. The probability of malignancy increased inversely with the IR from 60%, with RI below 0.60 to 100% with IR below 0.4.
Assuntos
Adenocarcinoma/diagnóstico por imagem , Cistadenocarcinoma/diagnóstico por imagem , Neoplasias Ovarianas/diagnóstico por imagem , Adenocarcinoma/patologia , Adulto , Idoso , Cistadenocarcinoma/patologia , Feminino , Humanos , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Neoplasias Ovarianas/patologia , Estudos Prospectivos , UltrassonografiaRESUMO
Two cases of pelvic collections of different etiology, admitted in the isolation unit of the Gynecology and Obstetrics Department of Hospital del Salvador are presented. Both were resolved by means of ultrasound transabdominal puncture, the first a tubo-ovarian abscess, in which there was placed a percutaneous drainage, and the second, a Residual Lutein Cyst, (Subsequent' to an Ectopic Pregnancy resolved by surgery) by means only of punction. In the first case (tubo-ovarian abscess) the patient became pregnant 2 months after de punction having actually a physiologic evolution. In the second case the patient is asymptomatic and has normal medical controls.
