Search PubMed⌕ Search

Biomedical subjects

N Kopp

Publications and source records attributed to N Kopp.

At least 55 records · Page 3Linked to original sources
PubMed1995

Changing pattern of primary hyperoxaluria in Switzerland.

BACKGROUND: The clinical course of primary hyperoxaluria (PH) is greatly variable and diagnosis is often delayed. Little is known about the overall occurrence and current prognosis. METHODS: We evaluated all known patients with PH residing and observed in Switzerland during the last 15 years with the help of a survey among Swiss nephrologists. RESULTS: Of the 25 patients observed between 7/79 and 6/94 in Switzerland, 18 were alive in 1994-14 on conservative therapy and four on renal replacement therapy (RRT). Twenty-two patients had PH type 1; the exact type was not determined in three. The estimated prevalence of PH (type 1) is 2 per million population; the minimal incidence is 1 per 100,000 live births. Diagnosis was delayed by 8 years (median) except in infants. Five patients were pyridoxine sensitive. According to life table analysis, 20% of patients were in end-stage renal failure (ESRF) and 10% had died by the age of 15 years, and 50% were in ESRF and 20% dead at 25 years. Prognosis has improved: Five of 13 patients died during the first half of the observation period as opposed to two of 20 in the second part. CONCLUSIONS: Overall prognosis appears better than hitherto believed considering the large clinical spectrum of PH. Greater awareness of PH is needed to improve further long-term prognosis.

Adolescent↗
PubMed1994

Quantitative autoradiography of 5-HT1D and 5-HT1E binding sites labelled by [3H]5-HT, in frontal cortex and the hippocampal region of the human brain.

In human cortex and hippocampus area, [3H]5-HT (5 nM) labels 5-HT1A, 5-HT1D and 5-HT1E sites. After masking 5-HT1A receptors by 0.1 microM 8-OH-DPAT, the binding displaced by 0.1 microM 5-CT presumably represented 5-HT1D sites and the remaining binding 5-HT1E sites. In frontal cortex, 5-HT1A receptors represented the main binding in layers II and VI and a lower fraction in other layers. 5-HT1D and 5-HT1E sites, were more homogeneously distributed in layers II to VI (21-34% of specific [3H]5-HT binding). 5-HT1E sites were of similar affinities (KD close to 6-8 nM) in the cortical layers II to VI. In CA1 field of hippocampus, (pyramidal layer, stratum radiatum, molecular layer), CA2 and dentate gyrus, 5-HT1A receptors represented the major fraction, 5-HT1D sites a significant fraction and 5-HT1E a minor fraction of the specific [3H]5-HT binding. In CA3-CA4 fields, 5-HT1A receptors were less densely present, 5-HT1D sites were predominant and 5-HT1E sites represented a significant fraction (27%). The highest densities of 5-HT1E sites have been measured in subiculum, where 5-HT1A, 5-HT1D and 5-HT1E binding sites were equally represented and in entorhinal cortex where 5-HT1E sites represented the major binding in layer III. They were also present in layers II and IV (29 and 24%) and, to a lesser extent, in layers V and VI. 5-HT1A sites were predominant in layer VI, II and V and were less abundant in other layers. 5-HT1D were homogeneously present in layers II, III, IV and were present in low amounts in other layers. No 5-HT1E were detected in choroid plexus, where [3H]5-HT was dramatically reduced by mesulergine (5-HT2C receptors). No significant displacement of [3H]5-HT by mesulergine was measured in other structures.

8-Hydroxy-2-(di-n-propylamino)tetralin↗
PubMed1994

Autoradiographic localization of receptors for neuropeptide FF, FLFQPQRFamide, in human spinal sensory system.

The regional distribution of FLFQPQRFamide binding sites on fresh unfixed cryostate sections from post mortem specimens of human spinal cord and lower medulla oblongata was studied by quantitative autoradiographic methods using [125I]YLFQPQRFamide as ligand. Samples were taken from five cases who had died with no history of neurological disease at ages ranging from 5 months to 66 years. The biochemical and pharmacological characteristics of [125I]YLFQPQRFamide binding to mounted tissue sections were comparable to those reported for the rat in a previous study. [125I]YLFQPQRFamide appeared to interact reversibly with high affinity binding sites (Kd = 0.06 nM), distinct from opiate receptors. Sites labelled with [125I]YLFQPQRFamide were distributed unevenly within the human spinal cord and lower medulla oblongata, with the highest density in the superficial layers of the dorsal horn and the spinal trigeminal nucleus. Although moderate labelling was observed in the ventral part of spinal grey matter, dense labelling appeared in the gracile and cuneate nuclei. No binding sites were detected in white matter. These results show that, as in the rat, FLFQPQRFamide receptors in the human spinal cord and lower medulla oblongata, are mainly concentrated within spinal areas implicated in the analgesic action of opiates. The possible role of these receptors in modulating spinal nociceptive information is discussed with respect to the pharmacological effects of substances acting on FLFQPQRFamide receptors in animals.

Aged↗
PubMed1994

Localization and developmental pattern of vasoactive intestinal polypeptide binding sites in the human hypothalamus.

Using a quantitative in vitro autoradiographic approach, vasoactive intestinal polypeptide (VIP) binding site densities were compared in the post-mortem hypothalamus of human neonate/infant and adult. The densities were similar during development in most of the hypothalamic nuclei and areas examined underlying the stability of 125I-VIP binding sites in the post-mortem hypothalamus of young and adult individuals. However, the ventral part of the medial preoptic area, the medial, lateral, and supramammillary nuclei were characterized by an increase of 125I-VIP binding with age. In young and adult individuals, the highest densities of hypothalamic 125I-VIP binding sites were detected in the supraoptic and infundibular nuclei; the ependyma; the organum vasculosum of the lamina terminalis; the horizontal limb of the diagonal band of Broca; the ventral part of the medial preoptic area (in adult); the suprachiasmatic, paraventricular, and periventricular nuclei; and the medial and lateral mammillary nuclei in adult. Moderate densities were found in the vertical limb of the diagonal band of Broca, the bed nucleus of the stria terminalis, the ventral part of the medial preoptic area in neonate/infant, the medial and lateral mammillary nuclei in neonate/infant, the supramammillary nucleus in adult, the dorsal hypothalamic area, and the ventromedial nucleus. Low to moderate binding site densities were observed in the other hypothalamic regions of young or adult individuals. The nonspecific binding ranged from 15% of the total binding in the anterior hypothalamus to 20% in the mediobasal and posterior hypothalamic levels. Taken together, these results provide evidence for a large distribution of VIP binding sites in neonate/infant and adult human hypothalamus suggesting the implication of VIP in the development of this brain structure and the maintenance of its various functions.

Adult↗
PubMed1994

Uncompacted myelin lamellae in polyneuropathy, organomegaly, endocrinopathy, M-protein and skin changes syndrome. Ultrastructural study of peripheral nerve biopsy from 22 patients.

Mechanisms of peripheral neuropathies in polyneuropathy, organomegaly, endocrinopathy, M-protein and skin changes (POEMS) syndrome are poorly understood. A peripheral nerve biopsy was performed in 22 patients. Of these 9 had histological features of Castleman's disease on lymph node biopsies, and 19 had a monoclonal lambda light chain in their serum. Certain nerve fragments were paraffin embedded, others were frozen and studied by direct immunofluorescence, and others were fixed for ultrastructural examination. Paraffin-embedded fragments did not show any amyloid deposits, and at direct immunofluorescence there was no immunoglobulin fixation. At ultrastructural examination, features of uncompacted myelin lamellae (UML) were present in 19 patients, and their frequency varied from 1% to 16% of myelinated fibres. Up to now UML have been reported only in 7 patients with POEMS syndrome in the literature. UML have also been noticed in a few cases of inflammatory demyelinating polyradiculoneuritis and inherited tendency to pressure palsy.

Aged↗
PubMed1994

Studies of neuroregulators in the brain stem of SIDS.

Some dysmaturity of neuroregulator neuronal systems may be responsible for brain stem disorders. These disorders may partly explain the mechanism of death in SIDS. The available data using microbiochemical assays, immunocytochemical techniques and autoradiographic methods seem to show anomalies of some monoaminergic and of some peptidergic systems, especially in the medulla oblongata. All these data need to be confirmed by further studies. It should be understood that one positive effect of such neuroanatomical study on SIDS is to gain 'normative' data on the human brain during development.

Brain Stem↗
PubMed1993

Distribution of thyrotropin-releasing hormone binding sites: autoradiographic study in infant and adult human hippocampal formation.

The rostrocaudal distribution of thyrotropin-releasing hormone (TRH) binding sites was studied in the human hippocampus. Cryostat sections of the right and left hippocampi from 6 infants (2 h to 5 months of age) and 11 adults (24 to 92 years) were subjected to in vitro quantitative autoradiography using [3H]MeTRH as a ligand. A single class of high affinity [3H]MeTRH binding sites with an apparent dissociation constant in the nanomolar range has been shown both in the infant and the adult. The maximal number of these sites was higher in the infant. No significant difference was observed between the general patterns of the right and the left hippocampi when taking postmortem delay and age as parameters. The highest concentrations of [3H]MeTRH binding sites were localized in the uncinate gyrus, the uncal subiculum and in the whole length of the molecular layer of the dentate gyrus. The lowest densities were present in the ventral subiculum. The major difference observed between the infant and the adult appeared in the molecular layer of the dentate gyrus where the densities were two-fold higher in infants (189 +/- 6 versus 88 +/- 2 fmol/mg of tissue). The only marked difference in the distribution was localized in the caudal part of the body where no specific labeling was found in the presubiculum of the infant.

Adult↗
PubMed1993

Intraoperative histopathologic nerve examination in brachial plexus injury.

A new method of indirect intraoperative evaluation of axonal quality in a proximal nerve stump by immediate observation of the myelin sheath is presented. Using this method in 18 cases of brachial plexus injuries, the proximal stumps of particular roots or trunks were classified as unfavorable, favorable, or fair. This histologic grading was compared to the clinical result obtained after surgical repair of these nerves in the corresponding territory. In three cases, the proximal stump of the brachial plexus root was sacrificed because of an unfavorable grade, and a nerve transfer was performed: the results were useful in two cases and "academic" in one case. Among 12 cases with favorable histologic grades, nine were associated with useful function and three were "academic". Among three cases with a fair histologic grade, two were associated with an "academic" result and one was useful in a nine-year-old child. Retrospective comparison with classic examination after axon staining showed that intraoperative histopathologic grading was somewhat too optimistic in six cases and was relevant in 12 cases. This method may be helpful in choosing proper methods for brachial plexus repair. A normal or almost normal histopathologic condition in the proximal stump of the nerve is mandatory for obtaining a useful clinical result after repair.

Adolescent↗
PubMed1993

Absence of adrenergic neurons in nucleus tractus solitarius in sudden infant death syndrome.

Immunohistochemical study of catecholamine synthesizing enzymes tyrosine hydroxylase (TH) and phenylethanolamine-N-methyl transferase (PNMT) was performed in lower brain stem of 5 controls and 9 sudden infant death "syndrome" (SIDS) cases. No difference was noticed in TH immunoreactive neuronal groups. With anti-PNMT antibody, electively in nucleus gelatinosus (NG), a subnucleus of nucleus tractus solitarius, an absence of immunoreactivity was noticed. Catecholamine neuronal cell bodies in NG were present. The discussion favours a nonartefactual interpretation of data. A delay in maturation would be a possible explanation.

Brain Stem↗
PubMed1993

[Alexander's disease in adults and diffuse cerebral gliomatosis in 2 members of the same family].

A 31-year old woman died after 10 years of progressive dysautonomia and cerebellar and pyramidal symptoms. CT scan showed pontine, bulbar and cerebellar atrophy. Post-mortem examination revealed Rosenthal's fibers widespread throughout the CNS, but especially in the subependymal and perivascular regions. White matter cavitations involving peri-ventricular regions, hilum of dentate nuclei and pons were observed, leading to a diagnosis of adult form of Alexander's disease. At the age of 5, the patient had been operated upon for a chiasmatic tumor. Microscopic examination revealed a pilocytic astrocytoma without Rosenthal's fibers. No complementary radiotherapy had been done. Her mother has been operated upon in 1972, for a high-grade glioma and is still alive 20 years later. This suggests diffuse cerebral gliomatosis. This family history may suggest a relation between these different diseases. They might be the result of a transmissible astrocytic abnormality with varying expression.

Adult↗
PubMed1993

Brain banking for immunocytochemistry and autoradiography.

The aim of a human brain bank is to establish groups of matched brains (normal control versus pathological groups) for studying human diseases of the nervous system. This bank is obtained by means of autopsy performed with a very short post-mortem delay and from clinically and neuropathologically well-documented patients. According to research protocols, two types of brain tissue storage are performed: fixed tissue or frozen tissue. Brain dissection procedures are performed according to precise anatomical boundaries of each brain region. This paper will center on the questions raised by brain banking in relation to histological and immunocytochemical studies and to biochemistry and autoradiography of binding sites. The lack of neuroanatomical data of the human brain leads us to compare anatomical results obtained in animals to that of the human. Moreover, it is clear that human brains present numerous interindividual differences (Kopp et al., 1977; Jack et al., 1989). Therefore, investigations of the human brain should be made on a large series of brains indicating the necessity of a well-documented brain bank of tissue from normal controls and patients.

Autoradiography↗
PubMed1992

Benzodiazepine binding sites and their modulators in hippocampus of violent suicide victims.

Benzodiazepine binding sites were studied by autoradiography in several hippocampic layers in brains of drug-free violent suicide victims (hanging) and matched controls. Kd was increased in suicides, and when brain sections from control subjects were incubated in the bath fluid that had previously served to incubate sections from suicides, Kd was increased in the same way. Results are discussed in terms of possible modulators of benzodiazepine binding sites, mainly tissue GABA and amino acid concentrations.

Adolescent↗
PubMed1992

Disappearance of hypothalamic TRH asymmetry in suicide patients.

The aim of the present study was to investigate the functional and/or pathological significance of the hemispherical lateralization of TRH using radioimmunoassay to determine the TRH concentration of nuclei and areas within the hypothalamus of suicide patients, with matching measurement being carried out on control subjects. In suicide patients, we found no significant difference in TRH concentration between the left and right intrahypothalamic structures, while the group used as control subjects (see Borson-Chazot, 1986) showed a significant left side predominance in the ventromedial nucleus, paraventricular nucleus and area dorsalis. As regards the TRH concentration in the right intrahypothalamic structures, no significant difference was found between the suicide patients and the control subjects. The absence of the left TRH predominance for the three intra-hypothalamic structures in question may be of pathological significance.

Adult↗
PubMed1992

Beta-endorphin: regional levels profile in the brain of the human infant.

Immunoradiometrical determinations of beta-endorphin (beta-EP) levels in 29 discrete brain regions from a series of victims of "Sudden Infant Death Syndrome" yielded a uniformly low levels profile in various areas of telencephalon, thalamus, pons, cerebellum and medulla oblongata. This low levels profile was interrupted by intermediate and high beta-EP levels in the midbrain and in two diencephalic zones. This study provides, for the first time, a comprehensive, neurochemically determined regional profile of beta-EP levels in the brain of the human infant.

Brain Chemistry↗
PubMed1992

Quantitative autoradiographic study of somatostatin and neurotensin binding sites in medulla oblongata of SIDS.

Quantitative autoradiography analysis of neurotensin (NT) and somatostatin (SS) binding sites was performed on coronal sections of the medulla oblongata from 2 fetuses, 6 controls and 7 victims of Sudden Infant Death Syndrome (SIDS). Throughout the first postnatal year, mean SS binding site density was similar in controls and SIDS in all structures of the medulla oblongata. The density of neurotensin binding sites was significantly higher in the nucleus of tractus solitarius (NTS) of SIDS than in controls, but there was no significant differences in the other areas of the medulla oblongata. Our findings suggest an immature developmental pattern of increased NT binding sites the NTS of SIDS. This alteration may be related to an abnormal central cardiorespiratory and arousal control which is thought to be present in SIDS.

Autoradiography↗
PubMed1992

Ontogeny of peptides in human hypothalamus in relation to sudden infant death syndrome (SIDS).

The brains of mammals are not mature at birth, in particular in humans. Growth and brain development are influenced by the hormonal state in which the hypothalamus plays the major regulatory role. The maturation of the hormonal patterns leads to the physiological establishment of chronological variations as revealed by the circadian variations of both hypothalamic peptides and pituitary hormones (as illustrated for hypothalamic-pituitary-thyroid axis by the determination of thyro-stimulating hormone (TSH) and thyrotropin-releasing hormone (TRH) circadian rhythms in the rat (Jordan et al., 1989)). It has been established that hypothalamic peptide variations are regulated by hormonal feed-back and amine systems, with the maturation of the latter also being dependent upon the whole functional maturation of the brain. Though these systems have been studied in the rat, very little information is currently available with regard to the human brain. The only biochemical or immunohistochemical information published to date concerns either the fetus or the adult. We have studied four main peptidergic systems (somatostatin-releasing inhibiting factor (SRIF), thyrotropin-releasing hormone (TRH), luteinizing hormone-releasing hormone (LHRH) and delta sleep inducing peptide (DSIP) in post-mortem adults and infants and in sudden infant death syndrome (SIDS) brains either by autoradiography and/or immunochemistry of radioimmunology. From a technical point of view, human brain studies display certain pitfalls not present in animal studies. These may be divided into two subclasses: ante- and post-mortem. Ante-mortem problems concern mainly sex, laterality, nutritional and treatment patterns while post-mortem problems concern post-mortem delay and conditions before autopsy and hypothalamic dissection. This might induce dramatic changes in morphological, immunochemical and autoradiographic evaluations. The matching of pathological subjects with controls is particularly difficult in the case of SIDS because of the rapid changes which take place in physiological regulatory processes during the first year of life. Thus, the treatment of hypothalamic tissue samples both for immunochemistry, radioimmunology and autoradiographic studies required techniques which must be rigorously controlled. For example, SRIF studies were carried out with three different antibodies, which gave similar results. The use of different technical procedures as well as different antibodies is discussed. These types of differences might explain, at least in part, the discrepancy observed until now. As previously described in the fetus (Bugnon et al., 1977b; Bouras et al., 1987), we confirmed that in the infant hypothalamic SRIF immunoreactive cell bodies are present in the paraventricular and suprachiasmatic nuclei and in the periventricular area.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗