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Biomedical subjects

I Díaz

Publications and source records attributed to I Díaz.

25 records · Page 2Linked to original sources

Mapping helper virus functions for cucumber mosaic virus satellite RNA with pseudorecombinants derived from cucumber mosaic and tomato aspermy viruses.

P-TAV is a strain of tomato aspermy virus (TAV) able to efficiently support the systemic accumulation of some (i.e., B2-satRNA) but not of other (i.e., Ix-satRNA) strains of the satellite RNA (satRNA) of cucumber mosaic virus (CMV) in both tobacco and in tomato. As reported for V-TAV, the failure to support the systemic accumulation of Ix-satRNA seems to be due to an inefficient support of its systemic movement. Pseudorecombinants obtained by the exchange of RNAs 1 + 2 between P-TAV and Trk7-CMV, an efficient helper for the systemic accumulation of Ix-satRNA, were assayed for their ability to support the accumulation of CMV-satRNAs in tobacco plants and protoplasts. Pseudorecombinants having RNAs 1 + 2 from CMV supported the systemic movement and accumulation of CMV-satRNA as efficiently as CMV, whereas pseudorecombinants having RNAs 1 + 2 from TAV supported the CMV-satRNA very poorly. Thus, the ability to support the systemic movement and accumulation of CMV-satRNA is determined primarily by RNAs 1 + 2 and not by RNA 3, which is presumed to encode movement functions in the cucumoviruses and only has a minor, modulating effect on the systemic accumulation of satRNA. This suggests that for systemic movement CMV-satRNA has to interact with (the gene products of) RNAs 1 and/or 2 or that these viral RNAs compete with the satRNA for interaction with the coat or other movement proteins.

Cucumovirus↗

ms2i6A deficiency enhances proofreading in translation.

The hypermodified base 2-methylthio-N6-isopentenyladenosine (ms2i6A) at position 37 occurs frequently in tRNAs that read codons starting with uridine. Here we have studied how ms2i6A affects the accuracy of poly(U) translation in vitro. Deficiency leads to a higher rejection rate of tRNA4(Leu) by more aggressive proofreading on the wild-type ribosome, but with the initial selection step unchanged. Our data indicate that ms2i6A has no effect on codon-anticodon interactions on wild-type ribosomes as long as aminoacyl-tRNA is in ternary complex with EF-Tu and GTP. ms2i6A deficiency in the cognate poly(U) reader tRNA(Phe) leads to increased misreading when the near-cognate competitor tRNA4(Leu) is wild-type. ms2i6A deficiency in tRNA4(Leu) gives a decreased error level in competition with wild-type tRNA(Phe).

Codon↗

[Treatment of bladder endometriosis using the Nd-Yag laser].

The good results achieved in the treatment of gynecological endometriosis via laser laparoscopy prompted us to perform endoscopic Nd:Yag laser photocoagulation in the present case of symptomatic vesical endometriosis described herein. To our knowledge, this is the first reported case in the world literature.

Adult↗

[Our experience in the treatment of superficial cancer of the bladder with BCG].

We report on our experience with 21 patients with superficial bladder cancer who were treated with intravesical BCG instillation. The BCG vaccine was effective in the treatment of carcinoma in situ. Tumor regression was achieved in 83.3% at 3 months, and 61.1% at 24 months. It is advisable to follow patients closely because of the possibility of tumor progression.

Adult↗

Nuclear magnetic resonance in advanced prostate cancer (stage D).

Nuclear Magnetic Resonance (NMR), a recently developed diagnostic method, has proved to be useful in the study of patients with prostatic disease. The authors report their experience with this technique in 10 cases of advanced prostate cancer (stage D) treated with LH-RH agonists (HOE 766-Buserelin). NMR provided information on the size of the prostate, the invasion of the vesical floor and seminal vesicles and the involvement of the pelvic and retroperitoneal nodes. It was also useful for ruling out metastases in the pelvis and spinal column, and showed an excellent correlation with the bone scan. In 2 untreated cases, NMR was sufficient by itself to diagnose metastatic prostate cancer. However, given the current lack of experience, it is not yet possible to draw conclusions concerning the superiority of this technique over other methods in the diagnosis and staging of prostatic carcinoma.

Adenocarcinoma↗