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J Vilardell

Publications and source records attributed to J Vilardell.

At least 55 records · Page 3Linked to original sources

Regulation of the maize rab17 gene promoter in transgenic heterologous systems.

The maize rab17 gene is expressed in different plant parts in response to ABA and osmotic stress (J. Vilardell et al., Plant Mol Biol 14 (1990) 423-432). Here we demonstrate that 5' upstream sequences of the rab17 gene confer the appropriate patterns of expression on the chloramphenicol acetyl transferase (CAT) reporter gene in transgenic tobacco plants, as well as in protoplasts derived from cultured rice cells. Specifically, a CAT construct containing a large 5' upstream fragment of rab17 (-1330/+29) results in high levels of CAT activity in embryos, leaves and roots of transgenic plants subjected to water stress or ABA treatment. Transient expression assays in rice protoplasts transfected with CAT genes fused to rab17 promoter deletions indicate that a 300 bp DNA fragment (-351/-102) is sufficient to confer ABA responsiveness upon the reporter gene. Furthermore, a 100 bp sequence (-219/-102) is capable of conferring ABA responsiveness upon a minimal promoter derived from the 35S CaMV promoter. Gel retardation experiments indicate that maize nuclear proteins bind to this fragment. This region of 100 bp contains a sequence (ACGTGGC) which has been identified as an abscisic acid response element in studies of other ABA-responsive plant genes.

Cell Nucleus↗

Utility of pulsed Doppler in the diagnosis and follow-up of acute vascular graft rejection treated with OKT3 monoclonal antibody or antilymphocyte serum.

Fifteen patients with severe acute vascular graft rejection (twelve of them steroid-resistant) treated with OKT3 monoclonal antibody (8) or antilymphocyte serum (7) were sequentially studied with duplex-Doppler ultrasonography (DDUS). Measurements of intrarenal resistance were obtained by means of the resistive index (RI). During rejection episodes, the intrarenal resistance was increased in all patients (RI range: 0.89-1), with absent or reversed diastolic blood flow. Normalization of diastolic blood flow was documented prior to the decrease of serum creatinine level in all patients who recovered from a rejection episode. We conclude that DDUS is a noninvasive technique useful in the diagnosis and monitoring of acute vascular graft rejection. Prediction of graft outcome after rejection treatment could probably be made based on DDUS findings.

Adult↗

Cyclosporine's effect on insulin secretion in patients with kidney transplants.

Adverse effects of cyclosporine on glucose metabolism have been reported in patients with kidney transplantation, but steroids were present in all the immunosuppressive schedules evaluated. We have studied endocrine pancreatic function (OGTT measuring plasma insulin [IRI] and c-peptide [CP]) in 3 groups of patients, matched for age and body-mass index, 16-66 months after functioning Ktx. Seven patients were treated with CsA monotherapy (group I), 7 patients with CsA plus prednisone (group II), and 6 patients with azathioprine plus prednisone (group III). Seven healthy subjects formed the control group. OGTT was normal in all patients, except one in group II (impaired glucose tolerance). There were no significant differences between the 4 groups concerning fasting blood glucose and area under the glucose curve, as well as basal insulin levels, peak insulin response to glucose, and area under the insulin curve. Basal CP, peak CP response to glucose, and area under CP curve were lower in CG than in the 3 groups of patients. Basal CP in group II (4.4 +/- 2.2 ng/ml) was higher than in group I (2.8 +/- 0.6 ng/ml, P less than 0.05). Glucose/IRI molar ratio in group II (5.7 +/- 1.4, P greater than 0.05) was lower than in group I (7.3 +/- 1.8) and CG (8.0 +/- 2.1, P less than 0.025). Our results suggest that CsA at normal dosage has no clinically important effect on beta-cell function. The indirect evidence of insulin resistance observed in patients treated with CsA plus prednisone is ascribable to corticosteroid treatment.

Adult↗

Gene sequence, developmental expression, and protein phosphorylation of RAB-17 in maize.

The ABA-induced MA12 cDNA from maize, which encodes a set of highly phosphorylated embryo proteins, was used to isolate the corresponding genomic clone. This gene, called RAB-17 (responsive to ABA), encodes a basic, glycine-rich protein (mol. wt. 17,164) containing a cluster of 8 serine residues, seven of them contiguous. It is a homologue of the rice RAB-21 gene (Mundy J, Chua NH, EMBO J 7; 2279-2286, 1988). Phosphoamino acid analysis of the isolated protein indicates that only the serine residues are phosphorylated and a putative casein-type kinase phosphorylatable sequence was identified in the protein. The pattern of expression and in vivo phosphorylation of the RAB-17 protein was studied during maize embryo germination and in calli of both meristematic or embryonic origin. ABA treatment induced the synthesis of RAB-17 mRNA and protein in calli, however, the RAB-17 proteins were found to be highly phosphorylated only in embryos.

Abscisic Acid↗