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Biomedical subjects

M H Lequin

Publications and source records attributed to M H Lequin.

At least 19 recordsLinked to original sources
PubMed2006

Microcephaly and simplified gyral pattern of the brain associated with early onset insulin-dependent diabetes mellitus.

Two families are presented with a child suffering from microcephaly with a simplified gyral pattern of the brain (SGP) and early onset insulin dependent diabetes mellitus (IDDM). The first patient was diagnosed postmortally with Wolcott-Rallison syndrome, after her younger brother developed IDDM, and a homozygous mutation in the eukaryotic translation initiation factor 2-alpha kinase 3 was found. The younger brother did not undergo magnetic resonance imaging (MRI). The patient from the second family has no EIF2AK3 mutation. SGP is considered to arise from decreased neuronal proliferation or increased apoptosis at an early stage of embryonal development, but insight into the pathways involved is minimal. EIF2AK3 is involved in translation initiation. It has been proposed that loss of function mutations reduce the ability of the cell to respond to endoplasmic reticulum stress, resulting in apoptosis of pancreatic Langerhans cells. Our findings suggest that in some cases, early onset IDDM and SGP can arise from common mechanisms leading to increased apoptosis.

Age of Onset↗
PubMed2006

[Respiratory insufficiency caused by acute disseminated encephalomyelitis in a child].

A 1.5-year-old boy presented with progressive ataxia and meningeal irritation after a period of general malaise and fever. He was eventually admitted to a paediatric intensive care unit for respiratory insufficiency. A diagnosis of acute disseminated encephalomyelitis (ADEM) with pontine involvement was made. The patient was mechanically ventilated and treated with immunoglobulins and corticosteroids, after which he recovered almost completely. ADEM is characterised by rapidly progressive demyelination of the central nervous system. The exact incidence and aetiology are unknown. The disorder is considered to be an autoimmune reaction, and current treatment is aimed at the suppression of this reaction. Despite the dramatic clinical and radiological presentation of ADEM, the prognosis is favourable in most cases.

Adrenal Cortex Hormones↗
PubMed2005

Primitive neuroectodermal tumours (PNETs) located in the spinal canal; the relevance of classification as central or peripheral PNET : case report of a primary spinal PNET occurrence with a critical literature review.

Intraspinal location of central PNET (cPNET) is very rare. We present a case, critically review all publications of primary intraspinal cPNET occurrence and discuss tendencies in clinical presentation. In several previous attempts to summarise, authors often confused cPNET with peripheral PNET (pPNET). cPNET and pPNET are different entities with different immunohistochemical profiles and genetic backgrounds. Clinically, they are both aggressive tumours, but exhibit different characteristics in their local manifestation and metastatic spread. Survival rates are quite similar provided that treatment is applied according to the established protocols. Protocols in cPNET treatment differ from those for pPNET as regards the order of the treatment sub-modalities, specific chemotherapeutic regimen and intensity, radiation dose and its extent and consequently, the side effects. Therefore, failure to distinguish cPNET from pPNET leads to clinical guidance and treatment proposals based on false assumptions, which might effect outcomes. Often, distinguishing between cPNET and pPNET is easy, because they occur in different location. In the case of intraspinal tumour location, however, the differentiation is crucial because both primary cPNET and pPNET can occur intraspinally, even though this is rare. Nowadays, demonstrating the expression of MIC2 glycoprotein by immunocytochemical staining (CD99) showing the specific EWS-FLI1 chimeric gene presence in pPNET, offers an easy way of making a differential diagnosis between cPNET and pPNET.

12E7 Antigen↗
PubMed2005

Brain abnormalities in a case of malonyl-CoA decarboxylase deficiency.

Malonyl-CoA decarboxylase (MCD) deficiency is an extremely rare inborn error of metabolism that presents with metabolic acidosis, hypoglycemia, and/or cardiomyopathy. Patients also show neurological signs and symptoms that have been infrequently reported. We describe a girl with MCD deficiency, whose brain MRI shows white matter abnormalities and additionally diffuse pachygyria and periventricular heterotopia, consistent with a malformation of cortical development. MLYCD-gene sequence analysis shows normal genomic sequence but no messenger product, suggesting an abnormality of transcription regulation. Our patient has strikingly low appetite, which is interesting in the light of the proposed role of malonyl-CoA in the regulation of feeding control, but this remains to be confirmed in other patients. Considering the incomplete understanding of the role of metabolic pathways in brain development, patients with MCD deficiency should be evaluated with brain MRI and unexplained malformations of cortical development should be reason for metabolic screening.

Agenesis of Corpus Callosum↗
PubMed2005

Novel mutations in three families confirm a major role of COL4A1 in hereditary porencephaly.

BACKGROUND: Porencephaly (cystic cavities of the brain) is caused by perinatal vascular accidents from various causes. Several familial cases have been described and autosomal dominant inheritance linked to chromosome 13q has been suggested. COL4A1 is an essential component in basal membrane stability. Mouse mutants bearing an in-frame deletion of exon 40 of Col4a1 either die from haemorrhage in the perinatal period or have porencephaly in survivors. A report of inherited mutations in COL4A1 in two families has shown that familial porencephaly may have the same cause in humans. OBJECTIVE: To describe three novel COL4A1 mutations. RESULTS: The three mutations occurred in three unrelated Dutch families. There were two missense mutations of glycine residues predicted to result in abnormal collagen IV assembly, and one mutation predicted to abolish the traditional COL4A1 start codon. The last mutation was also present in an asymptomatic obligate carrier with white matter abnormalities on brain magnetic resonance imaging. CONCLUSIONS: This observation confirms COL4A1 as a major locus for genetic predisposition to perinatal cerebral haemorrhage and porencephaly and suggests variable expression of COL4A1 mutations.

Adult↗
PubMed2004

Digital radiogrammetry of the hand in a pediatric and adolescent Dutch Caucasian population: normative data and measurements in children with inflammatory bowel disease and juvenile chronic arthritis.

We have evaluated the applicability of a new Digital X-ray Radiogrammetry (DXR) system in a Dutch Caucasian pediatric population. For this study we enrolled 535 healthy participants who all signed an informed consent form. In addition, 20 children suffering from inflammatory bowel disease (IBD) and juvenile chronic arthritis (JCA) were enrolled. Radiographs of the left hand were obtained from all participants. From the healthy population a subset of children with a history of forearm fractures were separately analyzed. Measurements consisted of DXR (X-posure; Pronosco-Sectra, Linköping, Sweden). Five hundred thirty-five subjects were enrolled in the study. Twenty-two subjects (4.3%) were discontinued (age 3-10 years), all because of a nonrecognizable radiograph by the DXR system. The short-term coefficient of variation of DXR in this population was 0.59%. Significant differences in DXR-BMD between boys and girls for the ages of 11, 12, 16, 17, and 18 years were found. There were also significant differences in DXR-BMD between the sequential Tanner stages. For 88 subjects repeat radiographs were available (mean interval 1.8 years). In all cases an increase in DXR-BMD was seen. Girls with IBD, JCA, or a history of forearm fractures and boys with IBD showed a significantly lower DXR-BMD compared with healthy controls. We show that DXR is an applicable technique in children. Also, in a small subpopulation it is possible to discriminate children with a high risk of low BMD.

Adolescent↗
PubMed2004

Hereditary porencephaly: clinical and MRI findings in two Dutch families.

Familial porencephaly is a rare disorder causing motor impairment, hemiplegia, mental retardation and epilepsy in variable degrees. Two families with porencephaly and apparently dominant inheritance are reported. Brain MRI findings are reviewed and described in seven affected individuals. Most patients also show white matter abnormalities in the cerebral hemisphere, also contralateral to the cystic lesion. In the first family an obligate carrier was identified who did not have a cystic lesion but clear abnormalities of the white matter. Although a predisposition for thrombophilia has previously been reported, we did not observe any genetic, environmental or epigenetic predisposition for the porencephaly. The lesions are most compatible with a deep venous thrombosis/ischemic event occurring in a late stage of pregnancy, not necessarily aggravated by perinatal asphyxia.

Adolescent↗
PubMed2004

Arterial infarction caused by carotid artery dissection in the neonate.

Arterial stroke in a neonate caused by carotid artery dissection is rare. We report two cases, one with dissection at the level of the skull base, one just distal to the carotid bulb. Non-invasive techniques like MR angiography and sonography demonstrated the dissection accurately. MR imaging, especially the diffusion-weighted images, showed the extension and site of the cerebral infarction. In one case dissection could be suspected following vacuum and forceps extraction. In the other no obvious birth trauma was reported. In conclusion, in a neonate with clinical signs suggestive of cerebral infarction, dissection of the carotid artery should be considered.

Carotid Artery, Internal, Dissection↗
PubMed2004

Slide tracheoplasty for congenital tracheal stenosis.

BACKGROUND/PURPOSE: The aim of this study was to add to the experience of slide tracheoplasty in infants with congenital tracheal stenosis (CTS), to review the recent literature on this subject, and to evaluate the diagnostic workup in infants with CTS. METHODS: A retrospective review of 3 infants with CTS treated with slide tracheoplasty was conducted at our institution. They all underwent bronchoscopy, tracheobronchography, and echocardiography. Therapy consisted of slide tracheoplasty and simultaneous correction of associated vascular malformations. RESULTS: A pulmonary artery sling was missed initially on esophagography in 2 patients. Stridor became worse in 2 patients after tracheobronchography. After surgical therapy, 2 patients survived and were discharged 12 days after surgery. Both are without symptoms at follow-up of 12 and 20 months. One patient had inoperable restenosis and died 27 days after the operation. CONCLUSIONS: Esophagography is not a reliable tool to depict associated vascular anomalies for patients with CTS. According to the literature, computer tomography has become more reliable to depict the tracheobronchial tree and is useful to elucidate associated vascular anomalies as well. Compared with other surgical techniques for infants with CTS reported in the literature, slide tracheoplasty has fewer postoperative complications and comparable survival rates.

Esophagoscopy↗
PubMed2004

Progressive damage on high resolution computed tomography despite stable lung function in cystic fibrosis.

For effective clinical management of cystic fibrosis (CF) lung disease it is important to closely monitor the start and progression of lung damage. The aim of this study was to investigate the ability of high-resolution computed tomography (HRCT) scoring systems and pulmonary function tests (PFT) to detect changes in lung disease. CF children (n=48) had two HRCT scans in combination with two PFT 2 yrs apart. Their scans were scored using five scoring systems (Castile, Brody, Helbich, Santamaria and Bhalla). "Sensitivity" was defined as the ability to detect disease progression. In this group of children, HRCT scores worsened. PFT remained unchanged or improved. Of the HRCT parameters, mucous plugging and the severity, extent and peripheral extension of bronchiectasis worsened significantly. Relationships between changes in HRCT scores and PFT were weak. Substantial structural lung damage was evident in some children who had normal lung function. These data show that high-resolution computed tomography is more sensitive than pulmonary function tests in the detection of early and progressive lung disease, and suggest that high-resolution computed tomography may be useful in the follow up of cystic fibrosis children and as an outcome measure in studies that aim to reduce lung damage.

Child↗
PubMed2003

Estimation of lung growth using computed tomography.

Anatomical studies suggest that normal lungs grow by rapid alveolar addition until about 2 yrs of age followed by a gradual increase in alveolar dimensions. The aim of this study was to examine the hypothesis that normal lung growth can be monitored by computed tomography (CT). Therefore, the gas volume per gram of lung tissue was estimated from measurements of lung density obtained from CT scans performed on children throughout the growth period. CT scans were performed on 17 males and 18 females, ranging in age from 15 days-17.6 yrs. CT-measured lung weight was correlated with predicted post mortem values and CT measured gas volume with predicted values of functional residual capacity. The median value for lung expansion was 1.86 mL x g(-1) at 15 days, decreased to 0.79 mL x g(-1) by 2 yrs and then increased steadily to 5.07 mL x g(-1) at 17 yrs. Computed tomography scans can be used to estimate lung weight, gas volume and expansion of normal lungs during the growth period. The increase in the lung expansion after the age of 2 yrs suggests progressive alveolar expansion with increasing lung volume.

Adolescent↗
PubMed2002

Collagen Ialpha1 polymorphism is associated with bone characteristics in Caucasian children and young adults.

A large proportion of the variation in bone mass can be explained by genetic factors. We analyzed the G to T substitution in the Sp1 binding site in the first intron of the collagen type Ialpha1 (COLIA1) gene in relation to bone mass. The genotypes GG, GT, and TT were determined in 148 Caucasian children and young adults. We performed dual energy X-ray absorptiometry twice (mean follow-up time 4.4 years), and speed of sound (SOS) was assessed by tibial ultrasonometry at follow-up. Genotype distribution was 104 (70%) GG, 40 (27%) GT and 4 (3%) TT. Carriers of the T-allele had a 0.5 SDS (standard deviation score) decreased bone mineral content (BMC) of total body (P = 0.001), and a 0.4 SDS decreased bone mineral density (BMD) for both lumbar spine (P = 0.04) and total body (P = 0.05). The genotype effect on BMD and BMC decreased after adjustment for height or body mass index. When we calculated apparent BMD, these differences diminished to 0.1 SDS and were no longer significant. T-allele carriers had shorter stature (0.4 SDS; P = 0.04) and smaller bones (0.5 SDS lower width of the lumbar vertebral body; P = 0.01). The T-allele was also associated with lower SOS (P = 0.03), independent of BMD and BMC, and lower lean body mass. Similar associations were found at follow-up. The change in BMD and BMC SDS between the first and second measurement did not differ between the GG and GT&TT group. In conclusion, the COLIA1 polymorphism in children and young adults is associated with several bone characteristics. However, at least a part of the COLIA1 effect on bone mass may be related to differences in frame size.

Absorptiometry, Photon↗
PubMed2002

Spinal epidural abscess presenting with abdominal pain.

We report a case of spinal epidural abscess presenting as abdominal pain. An 7-year-old boy presented with abdominal pain. He was operated on under suspicion of appendicitis. During operation, no abnormalities were found. Postoperatively, the abdominal pain did not subside. Subsequently, the boy developed neurological abnormalities. MRI showed a spinal epidural abscess. A laminectomy was performed and the boy was treated with antibiotics; he recovered well. This case showed that it is important to consider a spinal epidural abscess as a cause of abdominal pain with fever in children.

Abdominal Pain↗
PubMed2002

Bone mineral assessment with tibial ultrasonometry and dual-energy X-ray absorptiometry in long-term survivors of acute lymphoblastic leukemia in childhood.

Acute lymphoblastic leukemia (ALL) in childhood is a serious disease that can affect growth and the attainment of maximal peak bone mass. The latter has recently been recognized as a risk factor for the development of osteoporosis later in life. To determine long-term effects of the disease itself and its treatment, we assessed the bone status of a group of long-term survivors of childhood ALL, all treated with high doses of steroids (dexamethasone) and methotrexate and without cranial irradiation. All 21 subjects enrolled in this cross-sectional study were diagnosed to have non-high-risk precursors acute lymphoblastic leukemia (12 boys and 9 girls, mean age 16.5 yr, range 12.2-25.4 yr). Standard deviation (SD) scores were calculated using a tibial ultrasound device and spinal dual-energy X-ray absorptiometry (DXA) device as bone assessment techniques. SD scores of those two different bone assessment techniques were compared. The mean SOS (speed of sound) SD scores (SDS) of the tibia (mean 0.26, standard deviation [sd] 1.00) were not significantly different from our reference value of 0. There was no significant difference between the SOS SDS in boys and girls. With DXA, no significant difference was seen between the mean BMD SDS and the reference data and no significant difference in BMD between boys and girls was found. The individual mean SDS for bone mineral density (BMD) of lumbar spine are 0.24 (sd 1.02), total body 0.17 (sd 1.00), and apparent BMD (BMAD) 0.07 (sd 1.09). Spearman's correlation between mean SOS SDS and mean BMD of lumbar spine was 0.47, mean SOS SDS and mean BMAD SDS was 0.43, and mean SOS SDS and mean BMD of total body was 0.49. These correlations were significant at the 0.05 level (two tailed). Despite high-dose dexamethasone and methotrexate used for treatment of these children with ALL, no long-term side effects on the bone mineral status of the subjects, measured with DXA or tibial ultrasonometry, could be determined.

Absorptiometry, Photon↗
PubMed2001

Quantitative tibial ultrasonometry versus radiographic phalangeal absorptiometry in a Caucasian pediatric population.

There is a need for a reliable bone assessment technique in children. In this study, we compare an existing technique used in children, radiographic absorptiometry (RA), with a relatively novel technique, quantitative tibial ultrasonometry (QUS). In a prospective cohort study, we enrolled 290 girls (mean age 12.7 years) and 273 boys (mean age 12.4 years). Radiographs of the left hand and the left index finger were taken with an aluminium reference wedge within the field of exposure. Radiographic absorptiometry on the second middle phalanx at the mid-level (BMD50%) and proximal quarter (BMD25%) was performed with interactive software. Tibial QUS was performed using the SoundScan Compact. Multiple regression analysis showed that SOS correlated significantly with BMD25% for both boys (r = 0.65, P < 0.001) and girls (r = 0.59, P < 0.001), taking into account age and gender. The same applied for the correlation between speed of sound (SOS) and BMD50% in boys (r = 0.62, P < 0.001) and girls (r = 0.67, P < 0.001). Cubic regression between calendar age and BMD25% showed the best fit for both boys (r2 = 0.60) and girls (r2 = 0.60). For BMD50% a difference in regression was found between boys and girls. Quadratic regression gave a satisfactory fit for boys (r2 = 0.61 ) whereas for girls, a cubic relation was best (r2 = 0.59). Overall, there was a significant correlation between BMD25% and BMD50% for boys r = 0.89 and for girls r = 0.91 (both P < 0.001). Our data show a significant correlation between two different bone assessment techniques. In addition, these data suggest that both tibial ultrasonometry and RA are useful techniques in children.

Absorptiometry, Photon↗
PubMed2001

Is the Greulich and Pyle atlas still valid for Dutch Caucasian children today?

BACKGROUND: In our Paediatric Radiology Department, the Greulich and Pyle technique is used to assess skeletal age. Several authors have raised questions with regard to the applicability of this technique in a contemporary paediatric and adolescent population. OBJECTIVE: To compare skeletal age and calendar age in a healthy Dutch Caucasian population in order to test the applicability in this specific population. MATERIALS AND METHODS: For this study we enrolled 278 Dutch Caucasian boys (age range 5.0-19.5 years, mean 12.6 years) and 294 Dutch Caucasian girls (age range 5.2-19.9 years, mean 12.2 years). Radiographs of the left hand were scored according to the Greulich and Pyle atlas by two investigators. RESULTS: Intra-observer coefficient of variation of duplicate assessment of skeletal age for investigator 1 (resident) was 2.4 % and for investigator 2 (radiologist) was 1.5 %. We found no significant systematic differences between the two observers regarding variability and levels of measurement, and the agreement was good. There was a strongly significant correlation between skeletal and calendar age rgirls = 0.974 and rboys = 0.979 (P < 0.001). On average, calendar age preceded skeletal age by a small amount (1.7 months in girls and 3.3 months in boys, both P < 0.001). CONCLUSIONS: The reliability of the Greulich and Pyle atlas in our study corresponds well with previously reported studies. Based on our data, we conclude that the Greulich and Pyle atlas is still applicable in Dutch Caucasian children and adolescents.

Adolescent↗
PubMed2001

Comparison between quantitative calcaneal and tibial ultrasound in a Dutch Caucasian pediatric and adolescent population.

In the field of bone densitometry, attention has recently been focused on the pediatric population. Quantitative ultrasound (QUS) as bone assessment technique has many advantages for children in comparison with bone assessment techniques that use ionizing radiation. In this pilot study, we investigated the use of calcaneal and tibial QUS systems in a healthy Caucasian pediatric population. We studied 120 healthy Caucasian Dutch children between ages 7 and 19 yr: 53 boys (mean age of 12.5 yr, range 4.5-18) and 67 girls (mean age of 13.5 yr; range 7.1-19). We recruited children from a large population who previously had participated in a bone assessment study performed at our hospital. Two operators performed calcaneal QUS of the right calcaneus and tibial QUS of the right tibia. The correlation between calcaneal and tibial ultrasound was modest but significant (r = 0.29; p < 0.01). Using the calcaneal device, we found in girls a weak positive correlation between skeletal age and speed of sound (SOS) (r = 0.38), broadband ultrasound attenuation (r = 0.57), and quantitative ultrasound index (r = 0.46), all with a value of p < 0.01. For boys all parameters failed to reach significance. Using the tibial device, we found a good correlation between skeletal age and SOS in girls (r = 0.76) and modest correlation in boys (r = 0.50), both with a value of p < 0.01. This is one of the first studies to present a comparison between two ultrasound techniques in children. At present we feel that, in light of the poor correlation with skeletal age, calcaneal ultrasound has yet to prove its efficacy in children. Tibial ultrasound seems to be a good bone assessment technique in children.

Adolescent↗