[Embolization of uterine fibroids]. / Embolisation des fibromyomes utérins.

Uterine artery embolization (UAE) for symptomatic leiomyomas is a new attractive treatment in patients who don't desire pregnancy and for which conventional therapy has failed. Uterine fibroid embolization can also be considered for patients who desire pregnancy when myomectomy is technically difficult or impossible and in case of recurrence after myomectomy. 90% improvements are commonly reported in abnormal bleeding, pelvic pains, and in bulk-related symptoms. Although numerous pregnancies have been reported after UAE, the fertility rate after UAE remains to be compared to myomectomy. Absolute contra-indications are pregnancy, endometrial carcinoma, gynaecologic infections, adnexal masses, and rapid growth of uterine leiomyomas (considered as a significant sign of sarcoma). Besides procedure related risks of angiography some specific complications are reported: deep pelvic vein thrombosis with exceptional pulmonary embolus, vaginal discharges with sometime transcervical expulsion of fibroid (5%), transient or permanent amenorrhea (4-5%) and extensive necrosis (1-2%) with possible perforation and infection. A hysterectomy is needed to manage this complication in 0.9 to 0.3% of case. The mortality rate of embolisation is evaluated to 1/3.000 against 6/10.000 for the hysterectomy. UAE is proposed as a less invasive alternative to hysterectomy and myomectomy for the treatment of symptomatic leiomyomas. This technique allows reducing the hospital stay, the convalescence period, the morbidity and the mortality rate compared to conventional surgical treatment.

[Uterine fibroids embolization: a review]. / Embolisation des fibromyomes utérins: mise au point.

Uterine artery embolization for symptomatic leiomyomas is a new attractive treatment in patients who do not desire pregnancy and for whom conventional therapy has failed. Uterine fibroid embolization can also be considered for patients who desire pregnancy when myomectomy is technically difficult or/and in case of recurrence after myomectomy. 90% improvements are commonly reported in abnormal bleeding, pelvic pain, and in bulk-related symptoms. This technique allows reduction of the hospital stay, the convalescence period, the morbidity and the mortality rate compared to conventional surgical treatment.

[Periventricular leukomalacia in premature infants: prognostic role of ultrasonography and MRI]. / Leucomalacie périventriculaire du prématuré: rôle pronostique de l'échographie et de l'IRM.

PURPOSE: To evaluate the role of cranial US and MRI to establish the neurological prognosis of premature infants with periventricular leukomalacia (PVL). PATIENTS AND METHODS: Follow-up results of cranial US and early MRI evaluation (before 25 weeks*) of 28 premature infants were retrospectively reviewed and compared to the neurological outcome at 18 months* (*corrected age). RESULTS: Follow-up by cranial US was more sensitive (8/28) than early MRI to detect cystic PVL lesions because of the transient nature of these cysts. This has prognostic implications since all patients (8/8) with cystic PVL lesions had neurological sequelae. MRI was useful, as a complement to cranial US, for the evaluation of non-cystic PVL lesions. Indeed, patients with evidence of hemorrhage or paucity of white matter at MRI had a higher risk of neurological sequelae (9/11) than infants with echogenic periventricular white matter at US without evidence of white matter abnormality at MRI (p < 0.013). CONCLUSION: MRI was useful, as a complement to cranial US, to evaluate the prognosis of infants with non-cystic PVL lesions.

Penetrating atherosclerotic ulcer of the descending thoracic aorta: treatment by endovascular stent-graft.

PURPOSE: To present four cases of penetrating ulcer of the descending thoracic aorta treated by transfemoral insertion of an endoluminal stent-graft. METHODS: Four patients with penetrating aortic ulcers were reviewed. Three cases were complicated by rupture, false aneurysm, or retrograde dissection. All patients were treated by endovascular stent-graft and were followed by helical computed tomography (CT). RESULTS: Endovascular stent-graft deployment was successful in all patients. However, in one case we observed a perigraft leak that spontaneously disappeared within the first month, and two interventions were needed for another patient. Following treatment, one episode of transient spinal ischemia was observed. The 30-day survival rate was 100%, but one patient died from pneumonia with cardiac failure 34 days after the procedure. In one patient, helical CT performed at 3 months showed a false aneurysm independent of the first ulcer. This patient refused any further treatment and suddenly died at home (unknown cause) after a 6-month follow-up period. CONCLUSION: Transluminal placement of endovascular stent-grafts for treatment of penetrating ulcers of the descending thoracic aorta appears to be a possible alternative to classical surgery. After treatment, follow-up by CT is essential to detect possible complications of the disease.

The proximal promoter and the start site cooperate to specify correct U1 snRNA transcription initiation by RNA polymerase II.

In this work, we attempted to gain insight into the detailed mechanism allowing correct transcription initiation of U1 snRNA genes by RNA polymerase II. Abolition of the CA motif residing at -1/+1 in the Xenopus U1 gene leads to a loss of the ability of the promoter to direct accurate initiation. A discrete site is selected only if a purine preceded by a pyrimidine is positioned at 58/57 bp downstream of the center of the PSE. The PSE alone is unable to designate a discrete initiation site. Rather, it serves to set the location of an initiation window without discriminating suitable from unsuitable initiation sites. The latter role is devoted to a PyPu sequence positioned at -1/+1. Therefore, it is the concomitant action of the PSE and an essential PyPu positioned at the proper distance from this promoter that specifies correct U1 snRNA transcription initiation by RNA polymerase II.

The differential transcriptional activity of two amphibian U1 small-nuclear RNA genes correlates with structural differences in the proximal sequence element.

We previously analyzed the transcription of an axolotl U1 small-nuclear RNA (snRNA) gene (AmU1) by microinjection into Xenopus laevis oocytes. In such an assay, AmU1 showed a low template activity compared to that of an X. laevis U1 snRNA gene (XlU1B2). Swapping the proximal sequence element (PSE) with that of XlU1B2 was required for AmU1 to acquire a transcription level equal to that of XlU1B2. In the present work, we examine the functional importance of the nucleotides that are common or different in both PSEs with the aim of identifying which nucleotides within the Xenopus U1 PSE are critical for this enhancement of Ambystoma mexicanum U1 snRNA transcription. The PSE mutation analysis showed that the central, phylogenetically conserved C-58/C-57 doublet is absolutely required for U1 promoter activity. In the 3' portion of this element, a CGC to ATG change (positions -54/-52) which partially restores the XlU1B2 PSE sequence, enables the AmU1 gene to gain the same transcriptional activity as XlU1B2. Remarkably, in this clustered point mutation, the sole C-54 to A-54 change is sufficient to obtain this increased level. Therefore, the activity of the AmU1 gene in injected Xenopus oocytes is strongly affected by a single sequence difference between AmU1 and XlU1B2 PSEs. This finding underscores the crucial importance of the nucleotide identity at position -54 to the function of the Xenopus U1 PSE.

Sequence, organization and transcriptional analysis of a gene encoding a U1 snRNA from the axolotl, Ambystoma mexicanum.

AmU1, a DNA fragment containing a U1 small nuclear RNA (snRNA)-encoding gene, was isolated from the axolotl, Ambystoma mexicanum. Although this U1 snRNA, produced in axolotl oocytes, exhibits the lowest degree of sequence conservation among vertebrates, its secondary structure is maintained by a number of compensatory base changes. The proximal sequence element (PSE) is only weakly similar to that of the previously characterized Xenopus laevis PSE. Exchanging either the entire upstream regions with their X. laevis U1 (XlU1) homologues or only the PSE with the XlU1 PSE increases the transcription rate of the AmU1 gene to a level similar to that of the XlU1 gene. However, while allowing the AmU1 gene to be transcribed with high efficiency in X. laevis oocytes, the strict swapping of the 12-bp constituting the XlU1 PSE does not confer competitive ability to the AmU1 gene. We present evidence that the PSE is the major, but not the only element responsible for the low template activity of the AmU1 gene in X. laevis oocytes and our data suggest that other sequences, perhaps flanking the PSE, might also influence the binding of factor(s) participating in the assembly of the transcription complex.

A common octamer motif binding protein is involved in the transcription of U6 snRNA by RNA polymerase III and U2 snRNA by RNA polymerase II.

The structure of a Xenopus U6 gene promoter has been investigated. Three regions in the 5'-flanking sequences of the gene that are important for U6 expression are defined. Deletion of the first, between positions -156 and -280 relative to the site of transcription initiation, reduces transcription to roughly 5% of its original level. Deletion of the second, between -60 and -77, abolishes transcription. These regions contain not only functional but also sequence homology to the previously defined distal and proximal sequence elements (DSE and PSE) of the Xenopus U2 promoter, although U2 is transcribed by RNA polymerase II and U6 by RNA polymerase III. Competition experiments show that at least the distal sequence elements of the two promoters bind to a common factor both in vivo and in vitro. Part of the sequence recognized by this factor is the octamer motif (ATG-CAAAT). A sequence similar to the common RNA polymerase II TATA box is also shown to have an effect, albeit minor, on U6 transcription. The U6 coding region contains a good match to the A box, part of all previously characterized RNA polymerase III promoters. Deletion of this region has no apparent effect on the efficiency or accuracy of U6 transcription.