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Biomedical subjects

J Boisvert

Publications and source records attributed to J Boisvert.

At least 37 records · Page 2Linked to original sources
PubMed1986

Multicystic dysplastic kidneys: spontaneous regression demonstrated with US.

In nine neonates, spontaneous regression of a multicystic dysplastic kidney (MCDK) was witnessed by means of repeated ultrasound (US) examinations. In three of these patients, the diagnosis was made in utero. Follow-up examinations at the ages of 3, 5, and 32 weeks post-partum showed what would have been called unilateral agenesis of the affected side if no fetal US study had been done. In the remaining neonates, the diagnosis was made postnatally, and marked reduction in size or complete disappearance of the MCDK was observed on serial US examinations. Three neonates underwent surgical exploration. No trace of a kidney, renal artery, or ureter was found in two. A small MCDK was removed in the third patient. US reveals new features of the natural history of MCDKs. Because malignant transformation of an MCDK is rare and because US provides a means of serial assessment, the authors believe a more conservative, nonsurgical approach is appropriate and recommend an observation time of 1 year before deciding on surgical intervention, unless other problems necessitate surgical removal of the MCDK.

Female↗
PubMed1985

Lesser omental thickness in normal children: baseline for detection of portal hypertension.

The lesser omentum between the left lobe of the liver and the aorta at the level of the celiac axis harbors the left gastric vein and artery, lymphatics, nerves, and some fatty tissue. In one study, it was found to be thickened in most of 50 children with portal hypertension, but normal values were not established. Lesser omental thickness was measured in 150 children without systemic, liver, or renal disease, and it was found that it did not exceed 1.7 times the diameter of the aorta at the same level. Increased measurements were obtained in children with portal hypertension, obesity, or systemic steroid therapy (by fatty infiltration), preaortic lymphadenopathy, or with transient interposition of the gastric antrum or pancreas between the liver and aorta. In the absence of obesity or lymphadenopathy, a lesser omentum measuring more than 1.7 times the aortic diameter should raise the possibility of portal hypertension.

Adolescent↗
PubMed1985

A pseudo-choledocal cyst.

A four-year-old boy presented with a history of intermittent obstructive jaundice. Investigation and surgical exploration revealed an abnormal configuration of the biliary tree which, to our knowledge, has never been otherwise reported.

Bile Ducts↗
PubMed1984

Urinary tract infection in children. A reappraisal of its radiologic investigation.

In a prospective study, 100 children with either an acute or a previous history of urinary tract infection were investigated by intravenous urography, micturition cystourethrography, and ultrasonography. The results from the three diagnostic modalities were compared: The urinary tracts in 59 patients were normal, and revealed some abnormality in 41. Ultrasonography proved to be superior to intravenous urography in outlining renal contours and in detecting subtle cortical changes secondary to urinary tract infection (such as slight increases in cortical thickness and edema or cortical scarring). The mucosa of the renal pelvis and bladder was more easily assessed by ultrasound than by intravenous urography. Both modalities were "equally" accurate in detecting important congenital malformations of the urinary tract. Ultrasound failed to detect 24 of 28 ureters demonstrating reflux on voiding cystourethrography. We propose that carefully performed abdominal ultrasonography can replace intravenous urography in the initial investigation of urinary tract infection in children. It should be done in association with a radiographic or radionuclide voiding cystogram. Intravenous urography would then become a complementary examination for abnormal or problematic patients.

Adolescent↗
PubMed1984

[Echography of pyloric stenosis].

In order to assess the accuracy of ultrasonographic (US) criteria for the diagnosis of pyloric stenosis (PS), the record of 78 infants admitted to Hôpital Sainte-Justine with the clinical diagnosis of PS during the past year was reviewed. Fifty-eight patients had PS at laparatomy. Thirty-four of these had US with 30 true positives and four "doubtful" findings. Twenty-two had normal US. Two of these had PS, nine gastroesophageal reflux and five normal barium studies of the upper gastrointestinal tract (the last six were followed clinically and remained well). The following were criteria for US diagnosis of PS: pyloric anteroposterior diameter greater than or equal to 1.5 cm, length greater than or equal to 2 cm or a muscle thickness greater than or equal to 4 mm. This series contains no false positive US studies and two false negatives, for a positive predictive accuracy of 94% and a negative predictive accuracy of 100% when we measure the length greater than or equal to 2 cm or combine a length of less than or equal to 2 cm with a muscle thickness greater than or equal to 4 mm.

Female↗
PubMed1984

[The role of echography in splenic injuries in children].

We have reviewed 39 cases of ruptured spleen in children from 1979 to march 1983 at Ste-Justine Hospital in Montreal. We were mainly interested in the role of ultrasonography, its value and limitations. The practical management is exposed. To the best of our knowledge, it is the first report of this kind in pediatrics.

Child↗
PubMed1981

Electrophoretic characterization of proteins and RNA of cytoplasmic polyhedrosis virus (CPV) from Euxoa scandens.

A cytoplasmic polyhedrosis virus (CPV) was isolated from Euxoa scandens and propagated in vitro in Lymantria dispar cells. The virions and polyhedra were analyzed by polyacrylamide gel electrophoresis. Polyhedra produced in vivo and in vitro contained six polypeptides with identical relative mobilities while nonoccluded viral particles produced in vivo were composed of four polypeptides. The RNA content of the purified virions extracted from infected midgut was resolved in ten segments with molecular weights similar to that of CPV type 5 RNA.

Animals↗
PubMed1981

Spontaneous splenic rupture in infectious mononucleosis: sonographic diagnosis and follow-up.

Spontaneous rupture of the spleen occurs as a serious but relatively infrequent complication of infectious mononucleosis. Over 100 such cases have been reported. In all but one of the cases previously reported, diagnosis of splenic rupture was made at laparotomy. Three new cases are reported where the diagnosis of splenic rupture was made using sonography. The patients were followed by sonography and none required laparotomy. Aspiration of the hematoma under sonographic control confirms the diagnosis and may be curative.

Adolescent↗
PubMed1978

Comparative methods of titration of Silverwater virus, an arthropod borne virus.

Silverwater virus (SIL) was titrated in vivo and in vitro. Using a microculture technique, TCID50 was found to be much more sensitive than both the plaque forming assay and the LD50. The latter was the least sensitive mode of titration of Silverwater virus. The addition of DEAE dextran and trypsin to the viral inoculum increased the number and diameter of the plaques.

Animals↗
PubMed1977

Effect of detergents and chemicals on purified vaccinia virus: analysis by SDS polyacrylamide gel electrophoresis and electron microscopy1,2.

Vaccinia virus particles were dissociated into their constituent polypeptides and analysed by sodium dodecyl sulfate (SDS) gel electrophoresis. Thirty-three distinct polypeptide bands were identified and their molecular weights ranged between 11 000 and 150 000 daltons. Specific staining of gels containing polypeptides of dissociated virions revealed the presence of eight glycopeptides. No lipopeptides were detected. Analysis of chemical extracts (urea, guanidine hydrochloride, and alkali treatment) of the virus by SDS gel electrophoresis indicated that a total of 10 to 14 different polypeptides ranging in molecular weights from 11 000 to 70 000 daltons were solubilized. Analysis of detergent extracts and of the remains of extracted viral particles has shown that the detergent Nonidet P-40 (NP-40) solubilized a total of 11 polypeptides of which 6 were glycopeptides. The other detergents sodium deoxycholate (SDC) and cetyl trimethyl ammonium bromide (CTAB) were not as selective. both solubilizing more than 25 of the polypeptides composing the virus. Gel electrophoresis results also indicated that most of the small molecular weight (11 000-70 000 daltons) polypeptides were readily solubilized by NP-40, SDC, and CTAB, while those with molecular weights of 70 000 daltons and higher were not well solubilized. The effects of detergents were also analysed by electron microscopy. Evidence was obtained for subpopulations of viral particles having different susceptibility to detergent extraction.

Electrophoresis, Polyacrylamide Gel↗