Showing papers by "French Institute of Health and Medical Research published in 1977"

Anatomical, Physiological and Biochemical Studies of the Cerebellum from Reeler Mutant Mouse

Abstract: The cerebellum of the homozygous reeler mouse shows a marked reduction in size and in the number of fissures, its dry mass and DNA content are respectively $\frac{1}{3}$ - $\frac{1}{4}$ and $\frac{1}{7}$ - $\frac{1}{8}$ of those of normal animals. Its high content in the P $_{400}$ protein, which is abundant in the Purkinje cell, indicates that the decrease in cell number associated with the fall in DNA affects primarily the granular cells. The anatomy of the reeler cerebellum is rather unique: a thin cortex with almost normal molecular, granular and Purkinje cell layers embracing a central mass of closely packed large neurons, mostly Purkinje cells. Purkinje cells may therefore be found in four different cellular environments: (1) at their normal position in the superficial cortical structure; (2) within the granular layer; (3) intermingled with white matter in the central mass; (4) overlapping with neurons of the deep cerebellar nuclei. The reeler cerebellum therefore offers a model to study to what extent local cellular interactions are required to achieve the planar organization of the Purkinje cell dendrites and the normal synaptic investment of these cells. Concerning the three-dimensional shape of Purkinje cells, only the rare ones located at their normal position and receiving a normal ratio of all their synaptic afferences succeed to develop a characteristic dendritic pattern. Purkinje cells within the granular layer show three distinct patterns of dendritic arrangements. The variation in shape of the Purkinje cell dendrites located in the central agranular mass mimics that described in other agranular cerebella: in particular they show randomly oriented dendrites devoid of spiny branchlets. Concerning the cerebellar circuitry, the specificity of most of the synaptic connections is preserved, despite important disorders in Purkinje cell distribution. Several important differences with the normal cerebellum have, however, been observed at the level of the Purkinje cell: (i) The density of climbing fibre varicosities increases in the central cerebellar mass, where Purkinje cells are deprived of parallel fibre afferences. In addition, electrophysiological studies reveal that, at this position, the response of the Purkinje cells to climbing fibre stimulation is graded by steps as a function of stimulus intensity instead of being all-or-none as found in the superficial cortex or in normal cerebellum. These deep Purkinje cells receive therefore several climbing fibres instead of only one as in normal adult cerebellum. (ii) Ectopic synapses (somato-dendritic and dendro-dendritic) between the soma and/or the dendrite of the granule cell as presynaptic element and mainly the Purkinje cell dendrites as postsynaptic element may form. (iii) Heterologous synapses between mossy fibres and Purkinje cell spines are found in the granular layer and within the central mass. The electrophysiological studies show that these synapses are functional.

Ovalbumin gene is split in chicken DNA

Abstract: The ovalbumin gene is split in chicken DNA. Two interruptions in the sequences coding for ovalbumin mRNA have been detected, at least one of them lying in the protein coding sequence. The unexpected gene organisation is present both in oviduct cells highly specialised in ovalbumin synthesis and in erythrocytes.

Enkephalin receptors on dopaminergic neurones in rat striatum.

Abstract: THE idea that morphine and other narcotic analgesics as well as opioid peptides affect the activity of nigrostriatal dopaminergic neurones is well supported. For instance these substances elicit changes in motor activity similar to those observed after blockade of dopamine (DA) receptors by neuroleptics, they increase DA turnover in striatum and several typical symptoms of the abstinence syndrome they provoke involve dopaminergic systems (see refs 1–3 for reviews). In agreement with these observations, a high density of ‘opiate receptors’4 and of enkephalin binding sites5,6, a high content in enkephalins7 and a dense network of enkephalin-containing neurones8 are found in the striatum. All these observations suggested the possible connection between alleged enkephalinergic neurones and the dopaminergic fibres ending in the striatum. We report here that both the regional distribution of high affinity (morphine-displaceable) binding sites for leucine-enkephalin (Leuenkephalin) in striatum and their decreased number after chemical or mechanical interruption of the nigrostriatal bundle support the assumption that enkephalinergic neurones terminate presynaptically on dopaminergic nerve terminals in the striatum.

Phenotypic characterisation of a unique non-T, non-B acute lymphoblastic leukaemia cell line

Abstract: MANY human lymphoblastoid cell lines have been established from subjects with different haemopoietic disorders as well as from normal individuals1–3. In most cases the inability to identify the precise origin of cells which have been established has limited the usefulness of these lines, especially those derived from leukaemic donors. Although there are a few important exceptions to this generalisation (2, 3, 4 and see below) it is significant that no lines have been established from the common form of acute lymphoblastic leukaemia (ALL) which is usually referred to as ‘null’ cell or ‘non-T, non-B’ ALL (refs 5–7). We describe here the establishment of a lymphoid cell line, Reh, derived from an acute lymphocytic leukaemia where the leukaemic identity of established cells is supported by kinetic data, chromosome markers and detection of leukaemia associated antigens and enzymes.

Characterization of a New Type of Human Papillomavirus That Causes Skin Warts

Abstract: A human papillomavirus (HPV) was isolated from the lesions of a patient (ML) bearing numerous hand common warts. This virus was compared with the well-characterized HPV found in typical plantar warts (plantar HPV). ML and plantar HPV DNAs have similar molecular weights (5.26 × 106 and 5.23 × 106, respectively) but were shown to be different by restriction enzyme analysis. When the cleavage products of both DNAs by endonuclease EcoRI, BamI, HpaI, or Hind were analyzed by electron microscopy, one, two, one, and four fragments were detected for ML HPV DNA instead of the two, one, two, and six fragments, respectively, detected for plantar HPV DNA. In contrast to plantar HPV DNA, a high proportion of ML HPV DNA molecules were resistant to these restriction enzymes. Most, if not all, of the molecules were either resistant to BamI and sensitive to EcoRI or sensitive to BamI and resistant to EcoRI. After denaturation and renaturation of the cleavage products of ML HPV DNA by a mixture of the two enzymes, the circular “heteroduplexes” formed showed one to three heterology loops corresponding to about 4 to 8% of the genome length. No sequence homology was detected between ML and plantar HPV DNAs by cRNA-DNA filter hybridization, by measuring the reassociation kinetics of an iodinated plantar HPV DNA in the presence of a 25-fold excess of ML HPV DNA, or by the heteroduplex technique. The two viruses had distinct electrophoretic polypeptide patterns and showed no antigenic cross-reaction by immunodiffusion or immunofluorescence techniques. Preliminary cRNA-DNA hybridization experiments, using viral DNAs from single or pooled plantar or hand warts, suggest that hand common warts are associated with viruses similar or related to ML HPV. The existence of at least two distinct types of HPVs that cause skin warts was demonstrated; they were provisionally called HPV type 1 and HPV type 2, with plantar HPV and ML HPV as prototypical viruses, respectively.

Biochemical characterisation of a serum thymic factor.

Abstract: THE search for biologically active peptides with hormonal properties has been intense. The thymus has been looked upon as a source of such materials by a number of investigators but so far no generally accepted compounds have emerged1–5. We present here a sequence for a nonapeptide which is found in the serum of several animal species, where its presence is thymus-dependent6–8.

Tamoxifen is a potent "pure" anti-oestrogen in chick oviduct.

Abstract: OESTROGEN responsive cells contain a specific proteinaceous macromolecule—one receptor—capable of recognising physiologically active oestrogens as well as a number of synthetic oestrogen agonists and antagonists1,2. In the nonstimulated state, the majority of receptors are located in the cytoplasmic fraction of responsive cells3,4, including the chick oviduct5. When oestrogen reaches the target cell, it binds to the cytoplasmic receptor causing its ‘activation’ and the translocation of the hormone–receptor complex to the nucleus. The interaction of receptor with chromatin is thought to facilitate gene transcription and the synthesis of proteins implicated in the changes characteristic of the oestrogenic response6,7. Receptor is retained in the nucleus for varying periods of time depending on the concentration and nature of the oestrogen. In the rat uterus, the length of time that receptor is retained in the nucleus correlates well with a number of parameters of the hormonal response8. The initial translocation of receptor to the nucleus is followed by a period of cytoplasmic receptor replenishment3–5,9. This process is very important as it has been implicated in the ability of cells to respond to subsequent oestrogenic stimulation10,11. Anti-oestrogens prevent oestrogens from expressing their full effects on oestrogen target tissues. Recent studies have indicated that some non-steroidal anti-oestrogens (CI-628, nafoxidine and clomiphene) bind to cytoplasmic oestrogen receptor, induce the translocation of the antagonist–receptor complex to the nucleus, but fail to stimulate subsequent cytoplasmic receptor replenishment12–14. Oestrogen antagonism would be primarily due to inhibition of cytoplasmic receptor replenishment12. Further, such a hypothesis could explain the weak oestrogenic activity of these compounds following a single injection when cytoplasmic receptor is translocated to the nucleus, and their subsequent potent anti-oestrogenic activity after serial injections when the low cytoplasmic receptor level is the limiting factor in receptor translocation15. We present here results which illustrate that this theory of anti-oestrogenic action does not hold for tamoxifen (ICI 46,474) in the chicken oviduct.

Neuroglial reactions secondary to Wallerian degeneration in the optic nerve of the postnatal rat: ultrastructural and quantitative study.

Abstract: Wallerian degeneration has been studied in the optic nerve of the rat after unilateral enucleation. The operation was performed at the key stages 2, 5, 8, 20 days post natal (DPN), in order to compare the reactions of immature cells with those of their adult counterpart. Post operation delay (DPO) was staged from 1 to 204 days. The electron microscope study provided qualitative data relative to the function and the fate of the different cell lines, neuroglial and exogenous, in the reactive processes. Semi-thin 1–μm sections stained with toluidine blue were used for the quantification of the different cell types at the various stages. Criteria of identification were those set-up by Ling et al. ('73) for the corpus callosum and neighboring structures. In the three first key stages (2, 5, 8 DPN) the proliferation of glioblasts is reduced in amount and shortened in time when compared to the control. In the last one (20 DPO) a small peak over control value of glioblastic gliosis corresponds to a reactive gliosis already shown by other in the adult. Glioblasts are closely dependent upon the surrounding tissue for their ultimate fate. Microglia are exclusively involved in the phagocytosis of axonal and cellular debris, in the form of loaded macrophages. The comparison of the different percentage curves reflects the intensity and the timing of their reactions which are dependent upon the surrounding tissue. Reactive astrocytes, whose essential function is the formation of a scar, may participate in phagocytosis, especially in young animals, whose glial cells are not fully differentiated. They progressively constitute up to 90% of the glial population. Oligodendrocytes which are normally responsible for myelination, are only rarely involved in active phagocytosis; the oligodendrocyte line is either inhibited (key stages 2,5 DPN) or interrupted in its differentiation (key stage 20). It appears then that the presence of healthy axons is essential for the differentiation and even to a lesser degree the survival of the oligodendrocyte line. For the latter, the more differentiated the cell is the better it survives. Finally, hematogenous cells occur only in youngest animals, and in the close vicinity of the lesion. The influence of the enucleation upon gliogenesis and maturation of the optic nerve illustrates the interference between genetic and epigenetic factors and the interdependence of neurons and glia in the ontogenesis of the central nervous system. It exemplifies the great plasticity of the central nervous system in the youngest animals, thus validating our experimental onto-pathologic approach.

Tannic acid and oxidized tannic acid on the functional state of rat intestinal epithelium.

Abstract: Diets containing tannic acid at the level of 3% of dry matter were fed to rats in order to ascertain the origin of fecal nitrogen and the effect of tannic acid on the intestinal mucosa. At the same time in order to explain the effect of oxidation of tannins, we administered diets containing oxidized tannic acid or tannic acid associated with an antioxidizer (sodium sulfite) at the level of 1% of dry matter. The increased excretion of sialic acid and glucosamine during ingestion of tannic acid indicated that the excess of fecal nitrogen mainly corresponds to the mucus hypersecretion observed by histology. Fecal analysis revealed perturbations in movements of water and ions. The study of the metabolic activity of isolated enterocytes and the activity of some enzymes in a homogenate of these cells showed an inhibition of oxygen consumption and succinic dehydrogenase activity. Addition of reducing agent (sodium sulfite) to the diet had little effect on the action of tannic acid; but previous oxidation of the tannin reduced the effects observed, particularly in the case of fecal nitrogen loss.

Pathological study of alpha‐chain disease, with special emphasis on evolution

Abstract: The pathology of six cases of alpha-chain disease (α-CD), four of which were followed until complete remission or death, was studied by histologic, immunofluorescence and ultrastructural techniques. The lesions could be classified in three histotopographical stages. The late stage C is an immunoblastic sarcoma probably deriving from the same clone as the initial plasmacytic stage A, stage B being a transitional one between A and C. The asynchronism of the lesions in different organs in the same patient requires a laparotomy for an accurate staging which determines the prognosis and the treatment. Complete and prolonged remissions have been observed at stage A only, sometimes with oral antibiotic treatment alone. At all stages, α-CD and the “Mediterranean lymphoma” share identical aetiological, clinical and pathological features. Accurate immunological studies will determine the precise frequency of α-CD protein synthesis in the latter syndrome.

An adaptation of the push-pull cannula method to study the in vivo release of (3H)dopamine synthesized from (3H)tyrosine in the cat caudate nucleus: effects of various physical and pharmacological treatments.

Abstract: — The release of [3H]dopamine ([3H]DA) continuously synthesized from l-[3,5–3H]tyrosine from the caudate nucleus of the cat was estimated in halothane anaesthetized or‘encephale isole’animals. For this purpose, an improved superfusion cannula, avoiding tissue damage, was used. The best localization for the tip of the superfusion cannula was found first by determining the topographical distribution of endogenous DA within the caudate nucleus. A rostro-caudal heterogenous distribution of the transmitter was detected. In perfusion experiments, l-[3,5–3H]tyrosine was introduced continuously at a rate of 33μl/min. [3H]DA was the only catecholamine found in serial 15 min fractions as revealed by cochromatography. The spontaneous release of [3H]DA was greater in anaesthetized than in ‘encephale isole’ cats; it represented 150 and 100 times the blank value, respectively. Depolarization by K+ (30 mm) applied locally in the striatum or by electrical or mechanical stimulation of the substantia nigra caused a transitory increase in [3H]DA release. Conversely, a decrease in nerve activity induced by tetrodotoxin (5 × 10−-7 m) or by electrocoagulation of the substantia nigra was associated with a decline in the amounts of [3H]DA in superfusates. A temporary reduction in [3H]DA release could also be obtained by a short-lasting cooling block of the substantia nigra. As expected, d-amphetamine (10−-5 m) and benzotropine(10−-7 m) added to the superfusing medium increased [3H]DA release. These pharmacological results, as well as the changes in [3H]DA release observed after various manipulations of the activity of dopaminergic neurones, confirms the validity and the high sensitivity of this approach.

Possible teratogenic effect of phenothiazines in human beings.

Abstract: A prospective survey was carried out by the French National Institute of Health and Medical Research (INSERM) in 12 University hospitals in Paris and included 12,764 women; 189 gave birth to babies with unequivocal, non-chromosomally based, malformations. There was a significant excess of malformed infants when women had taken phenothiazines during the first three months after the last menstrual period. This association did not seem due to chance or to bias and could not be explained by the influence of the outcome of previous pregnancies. These data are to be added to results of recent surveys showing a significant increase of malformations in children exposed in utero to anticonvulsants, carbamates, benzodiazepines, tricyclic antidepressants, and amphetamines.

Mercuric chloride-induced anti-glomerular basement membrane antibodies in the rat: genetic control.

Abstract: Mercuric chloride induces anti-glomerular basement membrane antibodies in the Brown-Norway rat. Various other inbred rat strains (Lewis, Wistar AG, August, PVG/c) were not found t o be able to produce such antibodies under the same experimental conditions. Hybrids (F1, F2 and F1 × LEW) were bred from Brown-Noway and Lewis rats and injected with mercuric chloride. It has been demonstrated that the induction of anti-glomerular basement membrane antibodies by mercuric chloride in these crosses is under genetic control. The response was found t o depend on two or three genes one of which was H-1-linked. The negative results obtained with L.BN congenic rats were in complete agreement with this conclusion.

Anti-Müllerian hormone is a functional marker of foetal Sertoli cells.

Abstract: REGRESSION of Mullerian ducts in male foetuses is mediated by a testicular factor distinct from testosterone1. This anti-Mullerian hormone (AMH), a protein which has been partially purified2, is synthesised by foetal Sertoli cells3. In mammals the first stage of testicular differentiation involves the arrangement of sustentacular or Sertoli cells around the gonocytes and their encasement in testicular cords. Leydig cells appear later in the interstitium and their differentiation is correlated with the onset of steroidogenesis. We thought that there might also be a correlation between the initiation of testicular anti-Mullerian activity and the differentiation of Sertoli cells. Little work has been done on anti-Mullerian activity of the early foetal testis. During the initial stages of testicular organogenesis in the rat4 and the guinea pig5, AMH production is low, but the rapid pace of sex differentiation in most rodents hampers sequential study. Using sows (Sus scrofa), we have avoided this problem, and confirmed that the correlation exists.

Effects of in vivo administration of dexamethasone, corticotropin and human chorionic gonadotropin on steroidogenesis and protein and DNA synthesis of testicular interstitial cells in prepuberal rats.

Abstract: The effects of in vivo administration of ACTH, dexamethasone, and hCG on steroidogenesis, protein and DNA synthesis of testicular interstitial cells of prepuberal rats were investigated. hCG stimulated both protein and DNA synthesis and increased plasma testosterone levels. ACTH and dexamethasone significantly lowered the plasma testosterone concentrations and the protein and DNA synthesis; however, ACTH had no effects on adrenalectomized rats. Plasma testosterone, and DNA and protein synthesis in interstitial cells of animals treated with both dexamethasone and hCG were significantly lower than in rats treated with hCG alone. The in vitro hCG stimulation of testosterone production by interstitial cells from dexamethasone- treated animals was significantly lower than that of the control group. Moreover, testosterone production by interstitial cells from dexamethasone- hCG-treated animals in the presence or in the absence of dbcAMP was lower than that of the hCG-treated group. The in vitro conversion of [3...

Renal denervation delays blood pressure increase in the spontaneously hypertensive rat.

Abstract: Bilateral surgical and chemical denervation of the kidneys in spontaneously hypertensive rats, performed 5 weeks after birth, delayed blood pressure increase by 2–3 weeks without affecting the rate of development or the final level of hypertension.

Stimulation by dopamine of luteinizing hormone-releasing hormone (LHRH) release from the mediobasal hypothalamus in male rats.

Abstract: Effects of neurotransmitters on in vitro release of LHRH from fragments of mediobasal hypothalamus were investigated. Incubations were carried out for 10 min in a Locke-HEPES medium in the presence of dithioerythritol (10−5M) and bacitracin (2 x 10−5M) to prevent catecholamine oxidation and peptide degradation, respectively. Addition of 3 x 10−9M to 10−7M concentrations of dopamine (DA) to the incubation medium released doserelated amounts of LHRH from hypothalamic fragments, including the medial and lateral palisadic zones of the median eminence, which contain most of the tubero-infundibular DA terminals. LHRH release did not occur when norepinephrine (10−7M) was added instead of DA or was it obtained when DA was incubated with the caudal portion of the mediobasal hypothalamus or the organum vasculosum of the lamina terminalis, which also contain LHRH but are poorly innervated by DA neurons. The effect of DA on palisadic structures was blocked by the addition of pimozide. Moreover, it seemed to be steroi...

The role of vision in compensation of vestibulo ocular reflex after hemilabyrinthectomy in the cat.

Abstract: 1. A new description of vestibulo-ocular responses to angular velocity steps has been used to quantify vestibular compensation in right hemilabyrinthectomized cats. The amplitudes (VM and CM) and the times of occurrence (tM and to) from stimulus onset of the peaks of slow phase eye velocity and slow cumulative eye position were computed for velocity steps directed towards the lesioned side (clockwise, CW) and towards the intact side (counterclockwise, CCW). In addition, the values of these parameters were corrected from the effects of spontaneous nystagmus, when present. 2. In animals recovering in normal laboratory conditions, spontaneous nystagmus disappeared within 10 days after operation. In CCW responses, vm decreased by about 45% during the first 3 days and then remained stationary during the next 2 weeks. In CW responses VM showed a rapid increase during the first 3 days, and then remained stationary. After 2 weeks, VM increased in both CW and CCW responses. CM changes substantially reproduced those of VM. 3. In animals put in the dark immediately after operation, spontaneous nystagmus persisted until re-exposure to light (up to 31 days) and then disappeared rapidly. VM in both CW and CCW responses remained at a low value during the dark period and became more or less doubled after one week of exposure to light. CM also increased rapidly in CW and CCW responses, after re-exposure to light. 4. In the discussion these results are compared with those concerning activity of single vestibular neurons during compensation. It is concluded that vision is a primary factor conditioning disinhibition of vestibular nuclei spontaneous activity after the critical phase of compensation.

Heart rate and heart rate variability during sleep in small-for-gestational age newborns.

Abstract: To assess the influence of intrauterine growth retardation on heart rate (HR) and HR variability during sleep, we performed polygraphic recordings in 10 small-for-gestational age (SGA) and 16 appropriate-for-gestational age (AGA) newborns. Both groups were clinically and neurologically normal and were at 37 to 41 wk conceptional age. RR intervals were analyzed using the short-time Fourier transform in three frequency bands: 1) high frequency, with a period 3-8 heartbeat; 2) mid frequency, with a period 10-25 heartbeat; and 3) low frequency, with a period 30-100 heartbeat. In both active and quiet sleep, SGA newborns significantly differed from AGA newborns by having a shorter RR interval (p < 0.01) and lower amplitude of HR variability in all bands (p < 0.05) except low frequency in quiet sleep. Quiet sleep differed from active sleep by having a longer RR interval (p < 0.05), higher high-frequency variability (p < 0.02) in both SGA and AGA newborns, and lower low-frequency variability (p < 0.005 for AGA newborns). Our data give evidence of clear modifications of both sympathetic and parasympathetic HR control in the at-risk SGA population. Similarity of between-state characteristics suggests maintained CNS control of HR in SGA as well as in AGA newborns. We speculate that between-group HR and HR variability differences may be related to augmented metabolic rate in SGA compared with AGA newborns.

Development of the metatarsophalangeal joint of the chick embryo: Morphological, ultrastructural and histochemical studies

Abstract: The histogenesis and mechanism of joint clefting of the developing chick embryo up to the fifteenth day of incubation have been studied morphologally, ultrastructurally, and by histochemical methods. Cell degenration was consistently noted 24 hours after differentiation of the joint tissue, and it is postulated that this early cell necrosis might account for the loosening of the medial part of articular mesenchyme (interzone) leading to differentiation of a three-layered embryonic joint. At the time of joint clefting degenerative cells were also seen in the peripheral parts of the developing articular cavity. In somes cases clefting was immediately preceded and/or accompanied by the appearance of elongated, basophilic and electron-opaque cells closely arranged along the zone of tissue cleavage. These cells were thought to be implicated in some way in the clefting process and later to constitute a surface cell layer of articular cartilage. In addition to these observations clear morphological and histo-autoradiographic evidence was found for the presence of an organic component, presumably mucopolysaccharide, in the primitive synovial fluid. Fluid secretion might also account for tissue cleavage at the sites of its accumulation. The data reported here suggest that joint cavity formation results from a combination of both intrinsic, genetically expressed and extrinsic mechanical factors acting synchronously.