Marianne Tondeur

Clinical, biochemical, and ultrastructural studies in a case of chondrodystrophy presenting the I-cell phenotype in tissue culture

A description is given of a boy who presented early and severe clinical and radiological signs of chondrodystrophy without increased mucopolysacchariduria. Liver acid β-galactosidase activity was decreased. Ultrastructural studies disclosed the presence of clear membrane-bound inclusions, particularly numerous in fibrocytes and glomerular epithelial cells. In hepatocytes and neurons only a few pleiomorphic inclusions were present. In skin tissue culture, living cells were filled with dark granules showing an aspect characteristic of the “I-cell” phenotype. Findings that distinguish this clinical pattern from the typical mucopolysaccharidoses are discussed.

NORA: a simple and reliable parameter for estimating renal output with or without frusemide challenge.

The aim of this study was to evaluate a simple parameter describing renal output, namely NORA (normalized residual activity). We first compared, in a simulated model, different parameters of transit to an ideal standard; we then compared, in a clinical study, NORA and output efficiency. 123I-hippurate, 99Tcm-DTPA and 99Tcm-MAG3 plasma curves, each with two levels of renal clearance, were convoluted by means of different types of simulated retention functions, with different mean transit times. On the reconstructed renograms, several parameters reflecting renal transit were determined and compared with mean transit time. In a second step, in 33 patients, we compared output efficiency and NORA (i.e. the residual renal activity), normalized by the renal activity at 2 min. These two parameters were calculated at the end of the renogram, at the end of the frusemide test and after the micturition phase. In the simulated model, both output efficiency and NORA were only slightly influenced by the level of overall renal function. In the clinical study, a good correlation was found between output efficiency and NORA, whatever part of the study considered (renogram, frusemide test, post-voiding image). NORA is a simple and reliable parameter that allows quantification of renal output; it is almost independent of the level of renal function and can be used whatever the timing of the frusemide injection.

Clinical value of FDG-PET/CT for the diagnosis of human immunodeficiency virus-associated fever of unknown origin: a retrospective study.

AimThe aim of this study was to evaluate retrospectively the usefulness of [18F]fluorodeoxyglucose (FDG)-PET/computed tomography (CT) in patients affected by human immunodeficiency virus and suffering from fever of unknown origin (HIV-associated FUO). Material and methodsTen patients (six males, four females, age 24–48 years) suffering from HIV-associated FUO were studied by FDG-PET/CT. Final diagnosis was established either by microbiological or histopathological analysis or by a more than 6-month follow-up. FDG-PET/CT was regarded as ‘helpful for diagnosis’ when the abnormal uptake pointed to the organ or location where the cause of fever was thereafter identified. ResultsNine out of 10 FDG-PET/CT were abnormal and the cause of fever was further demonstrated by other diagnostic procedures. An infectious process (tuberculosis) was diagnosed in six patients and a neoplasm in three (two lymphomas, one Kaposis sarcoma). FDG-PET/CT directly suggested sites for biopsy in six patients (tuberculous lymphadenitis and neoplasm). The only patient with normal FDG-PET/CT suffered from drug-induced fever. ConclusionFDG-PET/CT is a valuable tool in patients with HIV-associated FUO. FDG-PET/CT was categorized as ‘helpful for diagnosis’ in nine out of the 10 patients we studied. Adding the CT anatomical landmarks to the PET findings allowed an accurate and easy localization of the sites to be punctured in the six patients in whom histopathological diagnosis was needed.

Biochemical and ultrastructural studies in Hurler's syndrome

Hepatic and cerebral biopsies were performed in 2 children with the Hurler syndrome. Biochemical analysis and ultrastructural studies were made on these tissues. The results are presented and discussed.

CLINICAL, BIOCHEMICAL AND ULTRASTRUCTURAL STUDIES OF AN ATYPICAL FORM OF MUCOPOLYSACCHARIDOSIS

Two children, brother and sister, presenting a clinically peculiar form of mucopolysaccharidosis are reported. There exists a discrepancy between clinical and radiological data and biochemical findings. Enzyme study of the liver discloses a striking hyperactivity of the acid /J‐galactosidase. Hepatic ultrastructure differs from that of other previous descriptions of mucopolysaccharidoses, demonstrating a complex storage of lipids and mucopolysaccharides within swollen lysosomes.

Farber's disease as a ceramidosis: clinical, radiological and biochemical aspects.

ABSTRACT. A Case of Farbers disease associated with athyreosis is reported in a Belgian infant born from consanguineous parents. A detailed clinical observation made from the early onset of symptoms until the death of the patient at age of 22 months, together with radiological, morphological and biochemical data confirmed the diagnosis of Farbers disease and its specific storage process. Cultured fibroblast studies disclosed an abnormal catabolism of ceramides, presumably related to the deficiency in lysosomal ceramidase. Family history confirms that the disease is inherited as an autosomal recessive trait.

Escaping the correction for body surface area when calculating glomerular filtration rate in children

Purpose51Cr ethylene diamine tetraacetic acid (51Cr EDTA) clearance is nowadays considered as an accurate and reproducible method for measuring glomerular filtration rate (GFR) in children. Normal values in function of age, corrected for body surface area, have been recently updated. However, much criticism has been expressed about the validity of body surface area correction. The aim of the present paper was to present the normal GFR values, not corrected for body surface area, with the associated percentile curves.MethodsFor that purpose, the same patients as in the previous paper were selected, namely those with no recent urinary tract infection, having a normal left to right 99mTc MAG3 uptake ratio and a normal kidney morphology on the early parenchymal images. A single blood sample method was used for 51Cr EDTA clearance measurement.ResultsClearance values, not corrected for body surface area, increased progressively up to the adolescence.ConclusionThe percentile curves were determined and allow, for a single patient, to estimate accurately the level of non-corrected clearance and the evolution with time, whatever the age.

The robustness of the Patlak-Rutland slope for the determination of split renal function

The aim of this study was to evaluate the variability of the Patlak-Rutland slope as applied to the renal clearance method. We analysed the 99Tcm-mercaptoacetyltriglycine renograms of 17 non-selected patients (both children and adults, number of kidneys = 34) with a single kidney glomerular filtration rate of 6-73 ml min-1 1.73 m-2. the acquisition time for the renograms was 20 min with a frame duration of 20 s. First, correction for background activity was introduced using the perirenal area and the size ratio between the kidney and the perirenal area. The Patlak plot was then applied. The first two points were systematically rejected and a series of linear fits calculated from the experimental points, starting from the third point (i.e. 1 min). The final point of the fit never exceeded the time of the peak of the renogram minus one minute (Tmax - 1) and was always less than 5 min. Although simple visual inspection of the slopes would suggest that the experimental points were distributed accurately along a straight line, it appeared that the slope was strongly dependent on the number of points used for the determination of the fit. As a second step, we restricted the number of points for fitting to the time interval between 1 min and 2 min 40 s. This procedure appeared to show that the Patlak methodology is reliable, giving rise to only small variations in slope, depending on the number of points chosen. However, even in this narrow time interval, significant errors can be made, either because of the very early escape of the radionuclide or because of statistical noise (e.g. in renal failure the signal-to-noise ratio is unfavourable). Therefore, it is advisable, when using this methodology, to restrict the fitting procedure to the second minute of the study and to check visually that this fixed time interval gives rise to a slope that is well adapted to the Patlak plot.

Bilateral cerebral mediofrontal hypoactivity in Tc-99m HMPAO SPECT imaging.

Fifteen patients who had bilateral mediofrontal hypoactivity and 30 control subjects without this SPECT anomaly underwent Tc-99m HMPAO brain SPECT imaging. Bilateral mediofrontal hypoactivity was found in various neurologic disorders, Including subcortical arteriosclerotic encephalopathy, lacunar state, chronic alcoholism, progressive nonvascular dementia, carbon monoxide poisoning, and diabetes mellltus. This SPECT abnormality was, however, specifically associated with three clinical signs: motor disabilities predominating in the lower limbs, urinary incontinence, and akinetic mutism.

Can severely impaired cortical transit predict which children with pelvi-ureteric junction stenosis detected antenatally might benefit from pyeloplasty?

IntroductionUntil recently, renogram, performed in children with pelvi-ureteric junction stenosis detected antenatally, has not been able to predict the probability of function improvement after surgery or the risk of function deterioration in case of conservative attitude. Recently, Schlotmann et al. have suggested that cortical transit might have this predictive role. The aim of this study, focused on those kidneys with severely impaired cortical transit, was to verify this statement. MethodsAll renograms performed in children during a 3-year period (n=729) were retrospectively reviewed and 19 pediatric patients were selected based on an antenatally detected unilateral pelvi-ureteric junction syndrome, the existence of at least two renograms during the follow-up and a severe cortical transit impairment, visually defined. Twenty-six pairs of data could be analyzed and allowed comparing preoperative and postoperative differential renal function (DRF), and the DRF changes during the conservative management. ResultsAmong the 16 patients who underwent pyeloplasty, 10 showed a significant DRF improvement. Among the 10 patients with conservative follow-up, four showed a significant DRF deterioration. ConclusionSeverely impaired cortical transit seems to be a valuable marker of those patients who could benefit from a pyeloplasty, either because of the high probability of postoperative DRF improvement, or because of DRF deterioration in case of an conservative approach. However, a normal cortical transit, as defined in this study, does not exclude the risk of DRF deterioration. Alternatively, the design of this study does not allow excluding the fact that DRF might improve after pyeloplasty despite a normal cortical transit.