[A case for diagnosis: ulceration of the skin caused by hydrea].
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Aged↗
Biomedical subjects
M Roger
Publications and source records attributed to M Roger.
The topographic distribution of the efferents from neocortical neurons is not only dependent upon where in the neocortex the cells develop. A transplantation study within one single neocortical region.
It has been proposed that the distribution of efferents developed by neocortical neurons depends upon where in the neocortex the cells develop, not where they were generated. However, the capacity of diverse isocortical areas to differentiate connectional characteristics belonging to other isocortical areas has recently been questioned in several experiments using heterotopic transplantation paradigms. The present study was designed to determine whether the principle of multipotentiality is still valid within one single isocortical region. Mediolateral bands of embryonic (E16) frontal neocortex were dissected out and grafted into the left frontal cortex of neonate hosts according to either correct or inverted mediolateral orientation. Five to six months after grafting, a retrograde tracer was injected into the dorsomedial or ventrolateral left neostriatum of the host. The mediolateral distribution of the cell labeling within the transplant was then compared to that of an equivalent frontal cortical area (ECA) in control cases. The results indicate that strips of embryonic frontal neocortex transplanted according to a correct mediolateral orientation are able to develop a projection towards the host striatum whose mediolateral topographical distribution is not significantly different from that arising from the frontal neocortex of control animals. The percentages of transplant cells labeled in the medial or lateral division of the grafts were not significantly different from those found medially or laterally in the ECA in control cases. Following inversion of the mediolateral orientation of the grafts at the time of transplantation, the percentages of cells labeled in the medial or lateral division of the grafts were nearly equal whatever the site of tracer deposit within the host neostriatum. These results indicate that even within one single neocortical region the principle of areal interchangeability is not entirely validated and that the development of neocortical efferents is not only guided by extrinsic factors.
Animals↗
Transplants of embryonic cortical tissue placed in the previously damaged frontal cortex of adult rats: local cerebral glucose utilization following execution of forelimb movements.
Transplantation of fetal cortical tissue into the motor cortex of adult rats was used as an experimental model to examine the functional integration of homotopic fetal neocortical grafts into the motor pathways of adult host brain. We have employed the [14C]2-deoxy-D-glucose method to analyse the metabolic activity of the transplant and host sensorimotor cortex: (i) in animals solicited to perform specific lever-pressing movements with the limb contralateral to the transplant (experimental group); and (ii) in non-solicited animals or in animals using the limb ipsilateral to the transplant (control group). Grafts in the control group displayed homogeneous uptake of 2-deoxy-D-glucose throughout the rostrocaudal extent of the transplant. The local cerebral glucose utilization levels were low as compared to those of the surrounding cortex but were at least two-times higher than in the corpus callosum. Increase in 2-deoxy-D-glucose uptake by the transplant cells was found only in the experimental group. In this group, 2-deoxy-D-glucose uptake was higher in the caudal (AP: +3.0 to +1.7 mm, relative to Bregma) than in the rostral sectors of the transplants suggesting the existence of a topographic organization within the transplant. In addition, except in the rostral part, glucose utilization was higher in the transplant of the experimental group than in the sensorimotor areas of the non-activated cortex in the control group. Moreover, glucose utilization of the transplant cells was systematically higher in the experimental than in the control group. The transplants appear to display a certain level of metabolic integration with the host sensorimotor cortex since, in the experimental group, there was no significant differences in local cerebral glucose utilization values in the caudal sector of the transplant and in the surrounding sensorimotor cortical areas of the host. The 2-deoxy-D-glucose uptake was even higher in the caudal sector of the transplant than in some of the subfields of the contralateral sensorimotor cortex. The present findings indicate for the first time that motor activation of the contralateral forelimb produces an increase in metabolic activity in distinct transplant sectors, the topographic distribution of which matches the normal topographic organization of the forelimb somatomotor map. This suggests that transplants of embryonic frontal neocortex placed in the frontal cortex of adult hosts become functionally integrated with the host motor system.(ABSTRACT TRUNCATED AT 400 WORDS)
Animals↗
Treatment of central precocious puberty with depot leuprorelin. French Leuprorelin Trial Group.
We evaluated the pituitary and gonadal suppression in 40 girls and nine boys treated with depot leuprorelin (3.75 mg sc if body weight > or = 20 kg, 1.87 mg if body weight < 20 kg) every 28 days for central precocious puberty. Gonadal suppression was obtained in most of the children with this dose: 3 months after initiation of the treatment, 85% of children had a peak plasma luteinizing hormone response to gonadotropin-releasing hormone < 3 IU/l and the gonadal axis remained suppressed throughout the duration of the study (up to 24 months). Four patients required higher doses of leuprorelin to achieve suppression. In two girls, a cutaneous reaction to the drug was associated with incomplete suppression and the treatment had to be interrupted. Plasma leuprorelin levels tended to increase from day 3 to day 28 after injection. Residual leuprorelin levels measured 28 days after injection were stable during the first year of the study. We conclude that an initial dose of depot leuprorelin of 3.75 mg sc every 28 days is efficient in most children with central precocious puberty.
Bone Development↗
Familial acromegaly: a specific clinical entity--further evidence from the genetic study of a three-generation family.
Familial acromegaly is a very rare inherited disorder, characterized by the clustering within a single family of several related cases with somatotroph adenomas and acromegaly. The causes of these dominantly inherited pituitary tumours remain unknown. Although these families have a clinical presentation distinct from that of multiple endocrine neoplasia type 1 (MEN-1), the question of this syndrome as being linked to the MEN-1 locus has remained open. Our aim was to study a three-generation family with cases of acromegaly in a mother and her son, to explore better the clinical presentation of the disease, its pattern of inheritance and to test the hypothesis of a genetic linkage to the MEN-1 locus using closely linked polymorphic genetic markers. The refined analysis of 15 unaffected relatives revealed miscellaneous non-specific endocrine dysfunctions and the presence of multiple lipomata, as noted previously in some cases. Moreover, the notion of acromegalo-gigantism in the maternal grandmother and an incomplete penetrance appeared even more typical, suggesting that familial acromegaly is a specific clinical entity. Finally, under the hypotheses assumed for segregation analysis, no clinical, biological or genetic evidence of linkage to the MEN-1 locus could be retained in this family. However, these conclusions were limited because of incomplete penetrance and uncertain definition of the carrier status. Therefore, we conclude that further identification of the genetic predisposition to familial acromegaly might be obtained from the combined molecular genetic analysis of several families presenting with the same clinical features.
Acromegaly↗
Three-dimensional MR of the inner ear with steady-state free precession.
PURPOSE: To describe the steady-state free-precession MR sequence and its application to the study of the inner ear. METHOD: The inner ear was imaged with CT and a 0.5-T MR unit in three dimension, to evaluate the various signals from the lumen of the labyrinth. RESULTS: Normally, the signal from the perilymphatic and endolymphatic spaces is homogeneous. However, among our cases of neurosensory deafness, differences of signal and morphology were seen in patients with otosclerosis, ossifying labyrinthitis, and inner ear malformations. CONCLUSION: Three-dimensional MR, used together with routine two-dimensional fast spin-echo, is another diagnostic too]l that can provide new data in the evaluation of the normal and unhealthy inner ear.
Cochlea↗
Efferents of frontal or occipital cortex grafted into adult rat's motor cortex.
Phaseolus vulgaris leucoagglutinin (PHA-L) was used to examine the efferent connectivity of embryonic (E16) frontal (homotopic) or occipital (heterotopic) neocortical transplants placed into--or in the vicinity of--lesion cavities made in the frontal cortex of adult recipients. Homotopic transplants projected towards the host sensorimotor cortex and, in most cases, into the lateral caudate-putamen (CPu). Heterotopic transplants projected into the anterior cingulate cortex and, in most cases, distributed terminals into the medial CPu. It is suggested that embryonic neocortical tissue placed into a damaged cortical site of an adult recipient develops a pattern of efferents corresponding to its cortical origin.
Animals↗
Topographic distribution of efferent fibers originating from homotopic or heterotopic transplants: heterotopically transplanted neurons retain some of the developmental characteristics corresponding to their site of origin.
The present study was undertaken to determine whether the topographical distribution of cortical efferents is exclusively dependent on environmental cues or is also controlled by intrinsic factors. For the purpose, we used a sensitive tract-tracing method (Phaseolus vulgaris leucoagglutinin) to compare the pattern of efferent fibers of homotopic and heterotopic transplants of embryonic (E16) neocortex. Our findings indicate that transplants of embryonic sensorimotor cortex placed homotopically in the sensorimotor cortex of newborn rats distribute a set of efferent projections not fundamentally different from that of normal sensorimotor cortex. The pattern of efferents arising from transplants of embryonic occipital cortex heterotopically placed in the sensorimotor cortex of newborns is strikingly different. Heterotopically transplanted neurons: (i) only rarely contact normal targets of the motor cortex; (ii) systematically project towards normal targets of the visual cortex (primary and secondary visual cortical areas, dorsal and ventral lateral geniculate nuclei, lateral dorsal and lateral posterior thalamic nuclei, anterior pretectal nucleus and superficial and intermediate layers of the superior colliculus); (iii) distribute fibers to structures normally receiving fibers from both motor and visual cortices (caudate-putamen, pontine nuclei), either exclusively into the visual cortico-recipient zone of the structure or into both visual and motor cortico-recipient zones. Taken together, these results seem to indicate that the heterotopically transplanted cells have retained certain anatomical characteristics of their locus of origin.
Animals↗
Coupled-cluster method applied to the motion of a single hole in a Hubbard antiferromagnet.
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Journal Article↗
Hypersensitivity of the corticotropic axis to the serotoninergic agent clomipramine in obese women.
Serotoninergic control of food intake has been shown to be abnormal in obese persons with a decrease in serotoninergic tone. The neuroendocrine effects of intravenous I.V. administration of clomipramine (CMI), a serotonin uptake inhibitor, were studied in normal-weight (n=7) and obese subjects before (n=12) and after (n=6) dietary restriction. Under double-blind, placebo-controlled conditions, a single 12.5 mg dose of CMI was administered. There was no difference in baseline values of prolactin (PRL), corticotropin (ACTH) and cortisol in non-obese controls, obese before and obese after weight loss. CMI led to significant increases of PRL, ACTH, and cortisol concentrations in the controls as well as the obese group. The ACTH and cortisol responses to CMI in obese subjects were somewhat greater than the responses in normal-weight subjects. The area under the curve AUC for ACTH after clomipramine was 6202 +/- 976 pg/ml x 150 minutes for tile obese before weight loss and 3274 +/- 512 pg/ml x 150 minutes for the controls and the difference was significant at the level of p=0.052. The cortisol peak value after clomipramine was 163.71 +/- 14.31 ng/ml in the non-obese and 214.66 +/- 12.59 ng/ml in the obese (p=0.025). However, there was no difference in the obese subjects before and after weight loss. These data support the assumption that obese women have an abnormal sensitivity to the serotoninergic control of the hypothalamic pituitary adrenal axis (HPA), and that a mild weight loss does not significantly modify their serotoninergic tone.
Adolescent↗
Electron microscopic demonstration of terminations of posterior thalamic axons on identified rubrospinal neurons in the rat.
In the rat, the major output of the posterior thalamic nucleus (PT) ends in the ventrolateral sector of the rostral two-thirds of the red nucleus. The aim of this study is to identify the rubral cells contacted by these thalamic efferents. In a first set of experiments, an anterograde neurotracer (PHA-L) was injected into the rostral part of the red nucleus. The only structure consistently and densely labeled was the contralateral spinal cord. Therefore, in a second set of experiments, massive HRP injections were made at different cervical levels in the spinal cord in combination with either electrolytic lesion or PHA-L injection in the contralateral PT. Both anterograde and retrograde labelings obtained in the RN were examined by correlated light and electron microscopy. Our findings indicate that anterogradely degenerated or labeled axons arising from the PT form synaptic contacts on HRP-filled dendritic processes of rubrospinal neurons. The thalamo-rubral articulation is direct and seems to be mainly axo-dendritic. These results support the possible participation of the PT in the modulatory control of spinal interneurons through the rubrospinal tract.
Animals↗
Responses to gonadotropin releasing hormone agonist and antagonist administration in patients with gonadotroph cell adenomas.
As they are clinically silent, gonadotroph cell pituitary adenomas are usually diagnosed only when pituitary enlargement causes visual impairment or hypopituitarism. In postmenopausal women presenting with pituitary tumors it can be difficult to determine whether gonadotropin hypersecretion is due to adenomatous or normal gonadotrophs prior to surgery. The usual GnRH dependency of gonadotropin secretion may be of diagnostic and therapeutic value. We therefore evaluated responses to the GnRH antagonist Nal-Glu-GnRH and to the long-acting GnRH agonist D-Trp6 (3.75 mg IM) in 9 and 4 patients with FSH- and/or alpha-subunit-secreting adenomas, respectively. Six of the 7 patients with FSH-secreting adenomas and one of the 2 patients with pure alpha subunit-secreting adenomas were studied postoperatively. In these patients postoperative FSH and/or alpha-subunit levels remained elevated and pituitary imaging by CT-scan and/or MRI disclosed tumoral residues. In the 2 remaining patients testing was performed preoperatively. A single administration of 5 mg Nal-Glu to the 7 patients with FSH-secreting adenomas produced a slight but significant fall in above-normal FSH levels from 24.4 +/- 15.4 IU/l to a nadir of 20.3 +/- 11.9 IU/l (-17%, p < 0.05) 20 h following the injection. LH levels fell markedly in the 6 patients with normal basal serum LH concentrations to those observed in hypophysectomized patients, while mean alpha-subunit levels were not modified. Alpha-subunit levels were not modified by Nal-Glu administration in the 2 patients with alpha-subunit-secreting adenomas.(ABSTRACT TRUNCATED AT 250 WORDS)
Adenoma↗
Heterogeneity of plasma gonadotropins. Consequences on immunological properties of LH.
The pituitary gonadotropins FSH and LH are secreted into blood as dimeric glycoproteins which display a wide heterogeneity when submitted to technique of separation based on electric charge. That supports the assumption of a major role of the carbohydrates moieties as a source of heterogeneity. No clear difference however has been demonstrated in the biological potency of the different isoforms occurring in blood. On the contrary, important discrepancies in immunological activity have been evidenced, mainly as far as LH is concerned. This is particularly important from a practical point of view since some monoclonal sandwich assays widely used for the measurement of LH levels fail to detect LH in samples from certain subjects. The description of the so-called "invisible LH" phenomenon should prompt international organizations to incite the manufacturers of commercial kits to improve the standardization in gonadotropin assays.
Female↗
Automata network predator-prey model with pursuit and evasion.
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Journal Article↗
Glycoprotein hormone alpha-subunit secretion in prolactinomas and in non-functioning adenomas: relation with the tumour size.
OBJECTIVE: Free glycoprotein hormone alpha-subunit plasma levels have been reported to be increased in glycoprotein hormone-secreting adenomas and in acromegaly, but rarely in prolactinomas and in only two cases of Cushing's disease. The prevalence of elevated plasma alpha-subunit levels in patients with non-functioning adenomas is still unclear. In addition, no previous work has described plasma alpha-subunit levels in a comprehensive series of adenomas characterized by in-vivo secretion and/or immunocytochemistry. PATIENTS: Thirty-seven patients with definite prolactinomas and 48 with non-functioning tumours characterized by immunocytochemistry were studied, from a series of 145 consecutive patients including 33 acromegalics, 18 patients with glycoprotein hormone-secreting adenomas and 9 with Cushing's disease. MEASUREMENTS: Plasma free alpha-subunit was measured by radioimmunoassay in all patients and in a large sample of normal subjects to establish normal ranges according to sex, age and menstrual status. Tumour volume index was the product in cm3 of length, width and height of the adenoma as assessed by computerized tomography or magnetic resonance imaging. RESULTS: Twelve of the 37 (32%) patients with prolactinomas had increased plasma alpha-subunit levels; their tumours were significantly larger with significantly higher plasma PRL levels than those of patients without increased plasma alpha-subunit levels (P < 0.02). All prolactinomas above 50 cm3 were associated with alpha-subunit secretion, whereas only 6 of 29 smaller tumours were similarly associated. Twelve of the 48 'non-functioning' adenomas actually secreted alpha-subunit in vivo: 8 gonadotrophin-secreting, 2 'pure' alpha-secreting, one with negative immunocytochemistry and one necrotic adenoma. Their volumes were significantly higher than those of adenomas without increased plasma alpha-subunit levels (P < 0.04). Plasma alpha-subunit levels were increased in the 6 patients with TSH-secreting adenomas, 8 of 12 with FSH-secreting adenomas, 11 of 33 acromegalics and none of those with Cushing's disease. CONCLUSION: Plasma free alpha-subunit levels were increased in 49 of 145 patients (34%). For prolactinomas and 'non-functioning' adenomas, alpha-subunit hypersecretion was seen more often with larger tumours. Half of the cases with increased free alpha-subunit in this series were patients harbouring an adenoma which did not stain for an intact glycoprotein hormone.
Adenoma↗
Transient bilateral papilloedema in a 10-year-old boy treated with recombinant insulin-like growth factor I for growth hormone receptor deficiency.
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Child↗
Evidence of oestradiol-induced changes in gonadotrophin secretion in men with feminizing Leydig cell tumours.
To study the sex steroid-gonadotrophin relationship, plasma oestradiol (E2), testosterone and gonadotrophin-releasing hormone (GnRH)-induced (100 micrograms iv) gonadotrophin response were measured in 42 male partners of infertile couples with normal sperm count (group I) and in 21 men with Leydig cell tumour (LCT, group II) in which a basal evaluation was repeated after tumour removal. Plasma free alpha-subunit (FAS), immunoreactive alpha-inhibin and luteinizing hormone (LH) pulse analysis were assessed in 10 LCT before and in six of them after surgery. Testosterone was significantly (p < 0.01) lower whereas E2 was significantly (p < 0.001) higher in group II than in group I. Gonadotrophin data were similar in both groups. The mean FAS was higher in group II than in group I and alpha-inhibin was higher than the normal range in 6/10 LCT. In group II, E2 levels were significantly (p < 0.01) and negatively correlated with testosterone, FSH, GnRH-induced gonadotrophin rise and LH pulse amplitude but not frequency. Significant (p < 0.001) changes were observed after surgery: E2 and alpha-inhibin fell; testosterone, LH and FSH rose; whereas FAS did not change significantly. The LH pulse amplitude but not frequency increased significantly (p < 0.05). In conclusion E2 oversecreted by LCT decreased LH and testosterone levels concomitantly. The GnRH-induced gonadotrophin level rose and the LH pulse amplitude decreased when the plasma E2 level rose, whereas the pulse frequency remained unaffected. A concomitant increase in alpha-inhibin and E2 is likely to be responsible for the drop in plasma FSH levels. These data support an action of excessive amounts of E2 at pituitary level, perhaps by decreasing the sensitivity of gonadotrophs to GnRH.
Adult↗
Metabolic mapping of the forelimb motor system in the rat: local cerebral glucose utilization following execution of forelimb movements mainly involving proximal musculature.
The present study was undertaken to establish a metabolic map of forelimb motor pathways under conditions of physiological activation. For that purpose, we used the [14C]2-deoxy-D-glucose (2-DG) method to identify forebrain and midbrain centers showing an increase in 2-DG uptake in animals trained to execute specific lever-pressing movements with the right forelimb. Following repetitive execution of these movements, principally involving proximal (shoulder, elbow, and wrist) muscles, increases in 2-DG uptake were found contralaterally in several neocortical or subcortical centers. The largest left-right differences in local cerebral glucose utilization (LCGU) were found in a central region of the sensorimotor cortex composed of the caudal part of area 3 of the frontal cortex (Fr3; p < 0.01), the intermediate part of area 1 of Fr (Fr1; p < 0.01), and the forelimb cortical area (p < 0.04). Fr3 was the brain center with the highest differences in left-right LCGU. This central region of the sensorimotor cortex seems to correspond closely to the caudal forelimb area of Neafsey et al. (1986). Intermediate left-right differences in LCGU were found (1) in the just-adjoining rostral-medial areas of the motor cortex involving the intermediate part of area 2 of Fr (Fr2; p < 0.01) and the rostral part of Fr1 (p < 0.04), and (2) in the rostral part of area 1 of the parietal cortex (Par1; p < 0.01) and the caudal part of area 2 of Par (Par2; p < 0.05), both corresponding to forelimb representation. Weak (not statistically significant) left-right differences in LCGU were found in the rostral parts of Fr2 and Fr3, in the caudal parts of Fr2 and Fr1, in the hindlimb cortical area, and in the caudal part of Par1 and the rostral part of Par2. In the remaining cortical areas (cingulate; agranular and granular retrosplenial; temporal; and occipital), there was practically no difference in left-right 2-DG uptake. In addition, increased 2-DG uptake was present contralaterally in several subcortical motor-related centers. In those centers in which a somatomotor map has been established (caudate putamen, ventral lateral and ventral posterolateral thalamic nuclei, and red nucleus), increased 2-DG uptake was found in regions corresponding to forelimb representation.(ABSTRACT TRUNCATED AT 250 WORDS)
Afferent Pathways↗