Jacques Boisvert

Investigation of childhood blunt abdominal trauma: a practical approach using ultrasound as the initial diagnostic modality

During a 5.5-year retrospective study (1979–84) 170 children with blunt abdominal trauma were investigated with intravenous urography (IVU), ultrasound (US) and scintigraphy. For the investigation of the last 71 children (after 1982) a 4th generation CT scanner was available in the same department. The results of radiologic investigations were compared with clinical outcome in 157 and results at laparotomy in 13 children. During the study period, real time US became the first line screening tool, and was combined with IVU in suspected renal trauma. In spite of permanent accessibility of CT since November 1982, the latter was used only in complex diagnostic problems or in children with multiple injuries (8% of the series). There were no deaths resulting from abdominal trauma. During the study, the incidence of splenectomy and exploratory laparotomy decreased, and no diagnostic peritoneal lavage were performed after 1980.

Fetal hydronephrosis: is there hope for consensus?

This review article aims at summarizing the data regarding fetal and neonatal hydronephrosis, at correlating controversial data with the differences in the practice of obstetrical sonography from one country to another, and finally, at presenting our own criteria for fetal renal collecting system dilatation along with our own guidelines of postnatal investigation.

Octameric CENP-A Nucleosomes Are Present at Human Centromeres throughout the Cell Cycle

The presence of a single centromere on each chromosome that signals formation of a mitotic kinetochore is central to accurate chromosome segregation. The histone H3 variant centromere protein-A (CENP-A) is critical for centromere identity and function; CENP-A chromatin acts as an epigenetic mark to direct both centromere and kinetochore assembly. Interpreting the centromere epigenetic mark ensures propagation of a single centromere per chromosome to maintain ploidy. Thus, understanding the nature of CENP-A chromatin is crucial for all cell divisions. However, there are ongoing debates over the fundamental composition of centromeric chromatin. Here we show that natively assembled human CENP-A nucleosomes are octameric throughout the cell cycle. Using total internal reflection fluorescence (TIRF)-coupled photobleaching-assisted copy-number counting of single nucleosomes obtained from cultured cells, we find that the majority of CENP-A nucleosomes contain CENP-A dimers. In addition, we detect the presence of H2B and H4 in these nucleosomes. Surprisingly, CENP-A associated with the chaperone HJURP can exist as either monomer or dimer, indicating possible assembly intermediates. Thus, our findings indicate that octameric CENP-A nucleosomes mark the centromeric region to ensure proper epigenetic inheritance and kinetochore assembly.

Antenatal diagnosis of ovarian cysts: natural history and therapeutic implications

A retrospective study from 1980 to 1990 shows 29 ovarian cysts in 27 patients diagnosed by prenatal ultrasound performed between 28 and 38 weeks of gestation. Ten patients underwent surgery, 17 patients were observed with serial ultrasound. Delayed good quality sonograms after spontaneous resolution of the cyst in a selected group of 7 patients showed restoration of a normal ovarian anatomy. The size of the cyst and/or its sonographic characteristics are the 2 main factors for deciding a conservative or a surgical management.

Normal portal venous diameter in children

A study was conducted on 156 children, in whom the portal veins were measured using standard real time ultrasonography. Knowledge of the normal dimension may be important in patients with liver disease.

Fetal sonography. I. Neural tube defects.

We reviewed retrospectively the medical and radiological charts of all patients seen in Sainte-Justine Hospital from 1980 to mid 1986 with a sonographic antenatal diagnosis of neural tube defects (186 cases) 1. For almost all pregnancies that were terminated, pathologic radiologic correlations were available. In our institution, obstetrical ultrasound is performed in the X-Ray Department by pediatric radiologists; half of the positive cases are referred by outside physicians after a first positive or equivocal examination. This accounts for the variable time of diagnosis in our series.