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Biomedical subjects

H Bruyere

Publications and source records attributed to H Bruyere.

7 recordsLinked to original sources
PubMed2006

V37I connexin 26 allele in patients with sensorineural hearing loss: evidence of its pathogenicity.

Sensorineural hearing loss (SNHL) is the most common inherited sensory disorder, reported in 1-3 of every 1,000 births. It has been estimated that 50% of all cases of prelingual SNHL are genetically determined. There is tremendous genetic heterogeneity, with multiple dominant and recessive loci. Mutations of the gap junction beta-2 gene (GJB2) emerge as a leading cause of autosomal recessive non-syndromic SNHL. Over 90 sequence alterations have been reported, the pathogenicity of some of them being unknown or unclear. The status of the V37I allele of connexin 26 (GJB2 amino acid product) with regards to its association with SNHL has been controversial. This study examines the pathogenicity of V37I by comparing the frequency of this allele in 40 patients with SNHL of Chinese and Caucasian descent with the frequency of the allele in 100 anonymized, ethnically matched controls. The V37I allele was identified in 43.75 and 11.5% of the patient and control alleles of Chinese ethnicity, respectively, but was not found in either Caucasian cohort. We also compiled the audiograms of 15 individuals with SNHL homozygous for the V37I allele, and showed that these individuals present with a mild to moderate SNHL. These results indicate that (1) the V37I allele is common in individuals of Chinese descent but rarely present in individuals of Caucasian decent; and (2) the V37I allele is pathogenic, but produces milder hearing loss compared to nonsense mutations of connexin 26 such as the 35delG mutation.

Alleles↗
PubMed2006

Leukocyte count as a predictor of death during remission induction in acute myeloid leukemia.

Acute myeloid leukemia (AML) presenting with a high leukocyte count has been associated with an increase in induction mortality and poor results in a number of other survival measures. However, the level at which an elevated leukocyte count has prognostic significance in AML remains unclear. In this report on a series of 375 adult (non-M3) AML patients undergoing induction chemotherapy at a single institution, leukocyte count analyzed as a continuous variable is shown to be a better predictor of induction death (ID) and overall survival (OS) than a leukocyte count of > or = 100 x 10(9)/L, a value characteristically associated with "hyperleukocytosis" (HL). In this patient cohort, a presenting leukocyte count of > or = 30 x 10(9)/L had high sensitivity and specificity for predicting ID, and both performance status (PS) and leukocyte count more accurately predicted for ID than age. Considering these parameters in newly-diagnosed AML patients may facilitate the development of strategies for reducing induction mortality.

Adolescent↗
PubMed2003

Cytogenetic and molecular study of a premature male infant with 46,XX derived from ICSI: case report.

We investigated the aetiology of the male phenotype in a premature infant derived from ICSI with a 46,XX karyotype. A karyotypically normal couple underwent ICSI because of obstructive azoospermia in the male partner. Sperm were retrieved by testicular sperm extraction (TESE), cryopreserved, and later used for ICSI. The pregnancy after ICSI ended at 20 weeks. A normal-appearing male was delivered but he did not survive. Umbilical cord blood and placenta were sampled and used for molecular and cytogenetic investigation. The 46,XX karyotype from G-banding in this male infant correlated to a balanced female comparative genomic hybridization (CGH) profile in placental tissue. No PCR amplification of SRY on the p arm of the Y chromosome was observed while fluorescence in-situ hybridization (FISH) with the SRY probe also could not detect the gene in cord blood or placental tissues. CGH and FISH, with X and Y centromeric probes, failed to detect mosaicism in the trophoblast, stroma and amnion. Skewed X-chromosome inactivation (81%) was found in the chorionic villi. The molecular and cytogenetic studies indicated a 46,XX male infant without the SRY gene or 46,XX/XY mosaicism. The possible mechanism in this SRY-negative XX male by ICSI is discussed.

Adult↗
PubMed2002

Fulminant tumour lysis syndrome in acute myelogenous leukaemia with inv(16)(p13;q22).

Tumour lysis syndrome (TLS) is caused by rapid breakdown of malignant cells resulting in electrolyte disturbances and acute renal failure. TLS has rarely been described in patients with acute myelogenous leukaemia (AML). Between November 1997 and July 2001, 114 consecutive adult AML patients aged <60 yr received induction chemotherapy consisting of cytosine arabinoside 1.5 g m(-2) q 12 h x 12 doses and daunorubicin 45 mg m(-2) d(-1) x 3 doses. During induction chemotherapy (CT), seven patients (6.1%, 95% CI 2.5-12.2) developed fulminant TLS, resulting in acute renal failure; five of these seven patients had inversion of chromosome 16 [inv(16)(p13;q22)], and one patient had a biological equivalent [t(16,16)(p13;q22)]. Four of the TLS patients underwent leukapheresis for a presenting white blood cell (WBC) count > 100 x 10(9) L(-1) prior to commencing chemotherapy, and six patients subsequently required haemodialysis for a median of 2 (range 1-8) wk. One TLS patient died of intracerebral hemorrhage on day 10 and another patient of multiorgan failure on day 17. Of the other five patients, all entered a complete remission (CR) and recovered normal renal function. Four patients remain in continuous CR [median follow-up 20 (range 12-25) months]. One patient relapsed at 12 months and again developed TLS on re-induction. In univariate analysis, TLS patients were more likely to have an elevated presentation and pre-chemotherapy WBC counts, elevated serum creatinine, and uric acid levels at presentation, as well as an inv(16). In multivariate analysis, only serum creatinine and inv(16) remained statistically significant (P < 0.001 for each). Patients with an inv(16) are a unique AML subgroup at high risk for fulminant TLS.

Adolescent↗
PubMed1999

Confirmation of linkage in X-linked infantile spasms (West syndrome) and refinement of the disease locus to Xp21.3-Xp22.1.

The syndrome of infantile spasms, hypsarrhythmia, and mental retardation (West syndrome) is a classical form of epilepsy, occurring in early infancy, which is etiologically heterogeneous. In rare families, West syndrome is an X-linked recessive condition, mapped to Xp11.4-Xpter (MIM 308350). We have identified a multi-generation family from Western Canada with this rare syndrome of infantile spasms, seen exclusively in male offspring from asymptomatic mothers, thereby confirming segregation as an X-linked recessive trait. Using highly polymorphic microsatellite CA-repeat probes evenly distributed over the entire X chromosome, linkage to markers DXS7110, DXS989, DXS1202, and DXS7106 was confirmed, with a maximum LOD score of 3.97 at a theta of 0.0. The identification of key recombinants refined the disease-containing interval between markers DXS1226 and the adrenal hypoplasia locus (AHC). This now maps the X-linked infantile spasms gene locus to chromosome Xp21.3-Xp22.1 and refines the interval containing the candidate gene to 7.0 cM. Furthermore, this interval overlaps several loci previously linked with either syndromic or non-syndromic X-linked mental retardation (XLMR), including one recognized locus implicated in neuroaxonal processing (radixin, RDXP2). Collectively, these studies lend strong support for the presence of one or more genes intrinsic to brain development and function, occurring within the critical interval defined between Xp21.3-Xp22.1.

Chromosome Mapping↗
PubMed1993

An interactive image processing system for the quantification of cardiac function in the embryonic chick.

This paper describes an interactive computer-based method for quantifying embryonic chick heart blood pool volumes that have been recorded as digitized image sequences. The primary motivation for the development of such a system is to be able to extract measurement data that is useful for evaluating potential drug-induced effects on intracardiac blood flow while minimizing variabilities in the measurements that typically occur when human evaluators extract the measurements visually from photographs. The processing that is used to achieve this goal can be divided into four basic steps: enhancing the contrast of the digitized embryonic chick heart image, extracting the shape of the blood pool in the embryonic chick heart ventricle from the enhanced image, quantifying the axial dimensions of the blood pool and calculating the required cardiac blood flow data. The technical details and the basic theory motivating each processing step are provided as well as an analysis of the results obtained by applying the method to actual image data.

Animals↗