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Biomedical subjects

M Tauber

Publications and source records attributed to M Tauber.

At least 19 recordsLinked to original sources

Molecular characterization of a cryptic 2q37 deletion in a patient with Albright hereditary osteodystrophy-like phenotype.

The Albright hereditary osteodystrophy-like (AHO-like) syndrome was recently defined as a rare dysmorphic syndrome including brachymetaphalangism and mental retardation. This phenotype occurs in Albright hereditary osteodystrophy (AHO) but unlike it, the level of the Gs alpha protein activity is not reduced. To date 59 patients with these clinical and biochemical features have been reported, and for the majority of them (57/59) a cytogenetically visible 2q37 deletion has been observed. We report a new case of typical AHO-like syndrome with normal karyotype. Using the polymorphic marker D2S125 we found a loss of heterozygosity suggestive of a de novo 2q37 deletion of maternal origin. This hypothesis was confirmed by FISH analysis with a subtelomeric 2q probe containing the D2S90 marker. Genotypic analysis allowed us to map the proximal breakpoint of the subtelomeric deletion within an interval delimited by D2S2338 (present) and D2S2253 (deleted). This 2q subtelomeric deletion as small as 4 Mb is to date the smallest one observed in association with a typical AHO-like phenotype, and allows us to move the centromeric boundary of the AHO-like critical region by 750 kb towards the 2q telomere.

Adolescent↗

Can some growth hormone (GH)-deficient children benefit from combined therapy with gonadotropin-releasing hormone analogs and GH? Results of a retrospective study.

Recombinant GH (rGH) treatment does not invariably correct height deficits in GH-deficient children once puberty has begun. The addition of GnRH analogs (GnRHa) to delay puberty has been advocated, but published results are few and sometimes conflicting. We retrospectively compared GH-deficient children treated with rGH and GnRHa for at least 1 yr after entering puberty and having attained their final height (n = 23) with a matched control group treated only with rGH. Overall, combined therapy did not significantly increase final height relative to rGH alone. However, the shortest girls at the onset of puberty (<25th percentile) benefited more than the tallest (>75th percentile) in both final height relative to predicted height and pubertal catch-up growth. In the control group, patients having experienced intrauterine growth retardation (IUGR) attained a lower mean final height than patients without IUGR (difference significant in boys, but not in girls). In the combined therapy group, IUGR did not affect the final height of either sex. Our results suggest that two populations might benefit most from combined GnRHa and rGH therapy: girls particularly short at the onset of puberty and patients who had experienced IUGR. Further prospective studies are required to confirm these preliminary hypothesis.

Adolescent↗

Clinical and endocrine characteristics in atypical and classical growth hormone insensitivity syndrome.

OBJECTIVE: Classical growth hormone insensitivity syndrome (GHIS) comprises a dysmorphic phenotype, extreme short stature (height SDS < 3), normal GH and low IGF-I and IGFBP-3. Wide clinical variation is recognised with classical and atypical forms. We aimed to delineate features of the milder "atypical" GHIS phenotype, and to determine whether this correlates with milder auxological and biochemical features. METHODS: Fifty-nine patients from a European series of 82 patients with GHIS, with strict diagnostic criteria of GHIS, were studied and assigned to classical or atypical GHIS groups according to facial phenotype, i.e. "classical" required 2 of 3 recognized GHIS features (frontal bossing, mid-facial hypoplasia and depressed nasal bridge), "atypical" required 0 or 1 of these facial features. Classical and atypical GHIS groups were compared in terms of (1) phenotypic features, including high-pitched voice, sparse hair, blue sclera, hypoglycaemia, microphallus, (2) birth length, height SDS, and (3) basal IGF-I, IGF-II, IGFBP-1, IGFBP-3, GHBP and increase in IGF-I on IGF-I generation testing. RESULTS: Fifty patients [24 males, 26 females, aged 8.6 +/- 4.6 years (mean +/- SD)] had "classical GHIS", 9 patients (7 males, 2 females, aged 7.8 +/- 4.1 years) had "atypical GHIS", 7 with normal facies. Atypical GHIS patients had lesser height deficit (Ht SDS -4.0 +/- 1.4) compared to classical GHIS (-6.7 +/- 1.4), less reduction in IGFBP-3 SDS (atypical -5.5 +/- 3.3; classical -8.6 +/- 2.4), and more had normal GHBP (>10% binding). Other variables were also less frequent in atypical GHIS patients: high-pitched voice 11% (70% classical), sparse hair 11% (42% classical), blue sclera 0% (38% classical), hypoglycaemia 11% (42% classical), and microphallus 14% (1 of 7 males), compared to 79% of classical (19 of 24 males). CONCLUSIONS: Atypical GHIS patients, with relatively normal facial appearance, demonstrate less height defect and biochemical abnormalities compared to classical patients. GH insensitivity may be present in children with short stature and an otherwise normal appearance.

Body Height↗

Composition of lipids from sunflower pollen (Helianthus annuus).

The contents of the pollen lipids of the sunflower Helianthus annuus are described. The major component is the seco-triterpene helianyl octanoate, followed by new beta-diketones as second major group of compounds. They exhibit a shorter chain length and often other positions of the functional group compared to already known beta-diketones. Of particular note are the 1-phenyl-beta-diketones, not previously reported from nature. Further lipid classes present are related hydroxyketones and diols. Interestingly, new beta-dioxoalkanoic acids are present in the extracts, which most likely are biogenetic precursors of the diketones. Additionally, we investigated the composition of the pollen coat which resembles the total extract, but lacks the dioxoalkanoic acids and certain estolides.

Chromatography, Gas↗

Infant-feeding patterns are related to blood cholesterol concentration in prepubertal children aged 5-11 y: the Fleurbaix-Laventie Ville Santé study.

OBJECTIVE: Several studies, mainly in animals, but also in humans, have shown that diet in infancy is associated with differences in blood cholesterol concentrations later in life. The objective was to examine this relationship in children aged 5-11 y after taking into account their current diet and parental hypercholesterolemia. SETTING AND SUBJECTS: 251 prepubertal boys and 223 prepubertal girls enrolled in the schools in two little towns in northern France. DESIGN AND METHODS: Cross-sectional evaluation including measurements of cholesterol concentrations on capillary blood and a single weekday food intake record. Infant feeding patterns were obtained by questionnaire given to the mothers. RESULTS: 50% of the children had been breast-fed for a median duration of less than 2 months. Cow's milk was introduced in the diet as whole milk for 33% of the children. After adjustment for age, height, and sibship, capillary cholesterol concentration was lower in boys who had been breast fed (geometric mean: 4.4, 95% confidence interval of the mean: 4.2-4.6 mmol/L) than in those fed with formula (4.7, 4.5-4.8 mmol/L, P<0.03). In girls, breastfeeding had no significant effect on blood cholesterol concentration, which was associated with the type of cow's milk given in infancy: whole milk: 4.9 mmol/L (4.7-5. 2); totally or partially skimmed milk: 4.5 mmol/L (4.2-4.6), P<0.008. The current saturated fat and cholesterol intakes and parental hypercyholesterolemia were associated with current blood cholesterol concentration in children, but did not modify its relationship with infant feeding patterns. CONCLUSION: Results of the present study suggest that diet in infancy may have longstanding effect on lipid metabolism. SPONSORSHIP: The study was supported by funds from Eridania Béghin-Say, Groupe Fournier, Lesieur and Nestlé France, Roche Diagnostic and of the MGEN (Mutuelle Générale de l'Education Nationale, contract INSERM-MGEN #9158) and a grant from the Association de Langue Française pour l'Etude du Diabète et du Métabolisme (ALFEDIAM). European Journal of Clinical Nutrition (2000) 54, 114-119

Animals↗

Auxological and endocrine evolution of 28 children with Prader-Willi syndrome: effect of GH therapy in 14 children.

We report on the auxological and endocrine evolution of 28 patients presenting with Prader-Willi syndrome. Half of them received growth hormone (GH) therapy (group 2). The spontaneous auxological evolution was analyzed in the two groups from 2 to 8 years; the mean SDS for height remained stable (-0.6 +/- 0.6) in group 1 and decreased (from -2.0 +/- 0.9 to -2.7 +/- 0.6) in group 2. Magnetic resonance imaging showed marked pituitary hypoplasia in the two groups. In group 2, the mean GH peak after two provocative tests was 3.8 +/- 2.4 microg/l, the mean SDS values for insulin-like growth factor I levels were -2.0 +/- 1.5 (range from -0.5 to -5.0). The mean duration of GH treatment was 3.6 +/- 2.9 (range 1-9.3) years. 14 children completed 1 year of treatment. The two groups had opposite evolutions in Delta SDS for height (-0.8 +/- 0.8 vs. +1.1 +/- 0.8), for growth velocity (-1.9 +/- 2.2 vs. +2.9 +/- 2.7), and for Z score of the body mass index (+0.37 +/- 1.3 vs. -0.14 +/- 0.76; group 1 vs. group 2). This retrospective study shows that, in children with Prader-Willi syndrome and true GH deficiency, long-term GH therapy is effective in increasing growth velocity and in maintaining body mass index.

Adolescent↗

Evaluation of cutaneous modifications in seventy-seven growth hormone-deficient children.

Cutaneous parameters such as dermal thickness, stiffness, elasticity, skin surface lipid and hydration were evaluated using noninvasive methods in 77 growth hormone-deficient (GHD) children before replacement therapy and in 70 non-GHD children. We showed that in GHD children, dermis was thinner (0.70 +/- 0.10 vs. 0.80 +/- 0.10 mm, p < 0.0001 for prepubertal children and 0.81 +/- 0.10 vs. 0.94 +/- 0.11 mm, p < 0.0001 for pubertal children), stiffer (178.5 +/- 57.3 vs. 113.09 +/- 37 kPa, p < 0.0001 for prepubertal children and 172.5 +/- 61.7 vs. 117.3 +/- 42.5 kPa for pubertal children, p < 0.001) and less elastic (0.44 +/- 0.09 vs. 0.39 +/- 0.06 (nonelasticity index), p < 0.01 for prepubertal children and 0.39 +/- 0.05 vs. 0.33 +/- 0.04, p < 0.001 for pubertal children) compared to controls. Fourteen GHD children were re-evaluated after 1 year of GH treatment: dermal thickness and skin stiffness were significantly improved (p < 0.001 and p < 0.05 respectively) while elasticity was not modified. During the same period, 11 controls did not show any significant cutaneous modification. IGF-1 values, but not IGFBP-3 values, correlated positively with dermal thickness in GHD children, before and after 1 year of GH treatment. To conclude, GHD children exhibited specific cutaneous modifications. In a subset of GHD children, we showed that these modifications were influenced by GH treatment. More extensive studies are needed to see if these changes correlated with other GH effects.

Adolescent↗

The enigmatic foramen lacerum.

OBJECTIVE: The microanatomic details of the foramen lacerum and surrounding region are described to clarify the relationship between the internal carotid artery and the foramen lacerum. The terminology related to these structures is reevaluated. Examples of pathological abnormalities restricted to the foramen lacerum region are presented to document the clinical relevance of this region. METHODS: Microanatomic dissections were performed in 12 formalin-fixed cadaveric specimens. Bony landmarks were examined in 50 dry skulls. Microscopic sections of the region were obtained from cadaveric specimens that were formalin-fixed, decalcified, and processed for histological examination. RESULTS: The foramen lacerum is not a true foramen. No significant structures traverse its fibrocartilage. In this region, the bony and fibrous structures surround the internal carotid artery to form an incomplete canal, which serves as the rostral extension of petrous canal. CONCLUSION: The term foramen lacerum should be restricted to that portion of the cranial base at the confluence of the petrous portion of the temporal, basioccipital, and basisphenoid bones that in vivo is filled with fibrocartilage. The region immediately above the foramen lacerum, occupied by the internal carotid artery and traditionally considered the upper portion of the foramen lacerum, should be considered, anatomically and functionally, to be the rostral extension of the petrous canal. We suggest calling this extension the lacerum portion of the carotid canal.

Anatomy, Artistic↗

Gonadotropin treatment of hypogonadotropic hypogonadal adolescents.

Testosterone substitution, needed for normal physical development in male hypogonadal adolescents, does not induce testicular growth. We treated 37 hypogonadal adolescents with gonadotropins (hCG/hMG), to obtain complete virilization during the first two years of treatment, to avoid psychological sequellae and to allow normal sexual development. Testicular volume increased significantly during therapy (from 1.98 +/- 1.2 to 9 +/- 3.3 ml), while testosterone rose from 0.26 +/- 0.04 to 5.3 +/- 0.8 ng/ml, with worse results in adolescents with cryptorchidism. hCG/hMG treatment had a better outcome than testosterone during the induction of puberty, avoiding psychological problems induced by atrophic testes. Further long term studies are necessary to evaluate whether early hCG/hMG treatment facilitates later spermatogenesis even in patients with cryptorchidism.

Adolescent↗

Shift of visual fixation dependent on background illumination.

Visual fixation, the act of maintaining the eyes directed toward a location of interest, is a highly skilled behavior necessary for high-level vision in primates. In spite of its significance, visual fixation is not well understood; it is not even clear what attributes of the visual input are used to control fixation. Here we show, in four Macaca fascicularis monkeys, that the position the eyes assume during fixation depends on the luminance of the background. Dark background yields fixation positions that are shifted upward with respect to the fixation positions obtained with a dimly illuminated, featureless background. This phenomenon was observed previously in a nutshell by Snodderly; here first we rigorously establish its existence by testing proper controls. We then study the properties of this upshift of the fixation position. We show that, although the size of the upshift varies between monkeys, for all monkeys the upshift is larger than the radius of the fovea. Hence, if the background is dim, the eyes are positioned during fixation so that the target does not fall on the fovea. The size of the upshift remains almost unchanged while the eyes fixate at different orbital positions; thus the upshift is not caused by orbital mechanics. The upshift clearly is present even at the first days of training, but with additional training in fixation with dark background, the upshift increases in size. The upshift rotates with the head. The upshift increases gradually with decreasing levels of background luminosity. Luminosity, not visual contrast, is indeed the primary variable determining the size of the upshift. The contribution of a unit area of the retina to the upshift decreases as inverse square root of distance from the target; therefore, it is the perifoveal region of the retina that mostly contributes to the upshift, while the far periphery has little influence. The upshift can be induced or be canceled in the midst of a fixation by changing the background illumination; hence, the upshift is indeed an attribute of the fixation control system. Finally, the fixation-upshift studied here is different from a previously reported upshift of the endpoints of memory-guided saccades with respect to their target locations. These two types of upshift add up to each other. In discussing the function of the upshift, we note a possible morphological analogue with the retinal rod distribution. The upshift moves the line of gaze to a point intermediate between the fovea and the "dorsal rod peak." The upshift thus may improve visual acuity in scotopic conditions. The brain structure in which the upshift is generated must be involved in both ocular control and visual sensation. We consider several possibilities, of which we regard as the most likely the cerebellum and superior colliculus.

Animals↗