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1.
J Neurophysiol ; 124(5): 1377-1387, 2020 11 01.
Article in English | MEDLINE | ID: mdl-32845208

ABSTRACT

Olivocochlear neurons make temporary cholinergic synapses on inner hair cells of the rodent cochlea in the first 2 to 3 wk after birth. Repetitive stimulation of these efferent neurons causes facilitation of evoked release and increased spontaneous release that continues for seconds to minutes. Presynaptic nicotinic acetylcholine receptors (nAChRs) are known to modulate neurotransmitter release from brain neurons. The present study explores the hypothesis that presynaptic nAChRs help to increase spontaneous release from efferent terminals on cochlear hair cells. Direct application of nicotine (which does not activate the hair cells' α9α10-containing nAChRs) produces sustained efferent transmitter release, implicating presynaptic nAChRs in this response. The effect of nicotine was reduced by application of ryanodine that reduces release of calcium from intraterminal stores.NEW & NOTEWORTHY Sensory organs exhibit spontaneous activity before the onset of response to external stimuli. Such activity in the cochlea is subject to modulation by cholinergic efferent neurons that directly inhibit sensory hair cells (inner hair cells). Those efferent neurons are themselves subject to various modulatory mechanisms. One such mechanism is positive feedback by released acetylcholine onto presynaptic nicotinic acetylcholine receptors causing further release of acetylcholine.


Subject(s)
Hair Cells, Auditory, Inner/physiology , Nicotine/administration & dosage , Receptors, Nicotinic/physiology , Animals , Cells, Cultured , Female , Hair Cells, Auditory, Inner/drug effects , Male , Membrane Potentials/drug effects , Mice, Inbred C57BL , Neurons, Efferent/drug effects , Neurons, Efferent/physiology
2.
Epidemiol Psychiatr Sci ; 27(6): 601-610, 2018 Dec.
Article in English | MEDLINE | ID: mdl-28606206

ABSTRACT

AIM: To examine the child outcomes at 18-months post-birth of a population cohort of women with antenatal depressed mood, half of whom were randomly chosen to receive perinatal home visits from community health workers during pregnancy. METHOD: Pregnant women in 24 neighbourhoods (98% participation) were randomised by neighbourhood to: (1) standard clinic care (SC; 12 neighbourhoods; n = 594) or (2) the Philani Intervention Program, a home visiting intervention plus standard care (12 neighbourhoods; n = 644). The physical and cognitive outcomes of children of mothers with antenatally depressed mood (Edinburg Perinatal Depression Scale >13) in the intervention condition were compared at 18-months post-birth to children of mothers without depressed mood in pregnancy in both conditions. RESULTS: More than a third of mothers had heightened levels of antenatal depressed mood (35%), similar across conditions. Antenatal depressed mood was significantly associated with being a mother living with HIV, using alcohol and food insecurity. At 18-months, the overall cognitive and motor scale scores on the Bayley Scales of Development were similar. However, 10.3% fewer children of mothers with antenatal depressed mood in the intervention condition had cognitive scores on the Bayley Scales that were less than 85 (i.e., s.d. = 2 lower than normal) compared with children of mothers with antenatal depressed mood in the SC condition. Intervention children of mothers with antenatal depressed mood were also significantly less likely to be undernourished (Weight-for-Age Z-scores < -2). CONCLUSION: Cognitive development and child growth among children born to mothers with antenatal depressed mood can be improved by mentor mother home visitors, probably resulting from better parenting and care received early in life.


Subject(s)
Child Development , Cognition/physiology , Community Health Workers , Depression/psychology , House Calls , Mothers/psychology , Pregnancy Complications/psychology , Adult , Child , Child Health , Counseling , Depression/epidemiology , Female , Humans , Maternal Health , Mother-Child Relations , Outcome Assessment, Health Care , Postpartum Period/psychology , Pregnancy , Prenatal Care , Prenatal Exposure Delayed Effects
3.
Hum Reprod ; 26(3): 671-7, 2011 Mar.
Article in English | MEDLINE | ID: mdl-21177311

ABSTRACT

BACKGROUND: Since in rodents anti-Müllerian hormone (AMH) has been shown to inhibit antral follicle responsiveness to FSH, we aimed at verifying whether a relationship exists between serum AMH levels and antral follicle responsiveness to exogenous FSH in normo-cycling women. METHODS: Serum AMH, estradiol (E(2)) and FSH levels were prospectively measured on cycle day 3 in patients undergoing controlled ovarian hyperstimulation (COH) with a time-release GnRH agonist and standardized FSH doses. In 162 patients, follicles were counted after pituitary suppression and before FSH administration (baseline; small antral follicles; 3-8 mm), and on the day of hCG (dhCG; pre-ovulatory follicles; 16-22 mm). Antral follicle responsiveness to FSH was estimated by the Follicular Output RaTe (FORT), determined by the ratio pre-ovulatory follicle count on dhCG × 100/small antral follicle count at baseline. RESULTS: Serum AMH levels were positively correlated with the number of small antral follicles at baseline (r = 0.59; P < 0.0001) and pre-ovulatory follicles on dhCG (r = 0.17; P < 0.04). Overall, FORT was 47.5 ± 1.4% and failed to be influenced by the woman's age, BMI or basal E(2) and FSH level. Conversely, multiple regression analysis showed that FORT was negatively correlated with AMH levels (r = -0.30; P < 0.001), irrespective of duration of COH and total FSH dose. CONCLUSIONS: The percentage of follicles that effectively respond to FSH by reaching pre-ovulatory maturation is negatively and independently related to serum AMH levels. Although the mechanisms underlying this finding remain unclear, it is in keeping with the hypothesis that AMH inhibits follicle sensitivity to FSH.


Subject(s)
Anti-Mullerian Hormone/blood , Anti-Mullerian Hormone/physiology , Follicle Stimulating Hormone/pharmacology , Infertility/blood , Oogenesis/drug effects , Ovarian Follicle/drug effects , Ovulation Induction , Adult , Algorithms , Embryo Transfer , Female , Fertilization in Vitro , Follicle Stimulating Hormone/blood , Follicle Stimulating Hormone/therapeutic use , Humans , Infertility/therapy , Oocyte Retrieval , Ovarian Follicle/cytology , Ovarian Follicle/diagnostic imaging , Recombinant Proteins/pharmacology , Recombinant Proteins/therapeutic use , Ultrasonography , Young Adult
4.
J Gynecol Obstet Biol Reprod (Paris) ; 40(2): 123-9, 2011 Apr.
Article in French | MEDLINE | ID: mdl-21050677

ABSTRACT

OBJECTIVES: Uterine fibroids is the most common benign pathology during reproductive age. Fibroids are implicated as a possible cause of infertility. The mechanism of infertility may depend on the size and the location of the fibroids and remain unclear. Myomectomy is performed in case of symptomatic patients who want to preserve their reproductive potential or in case of infertile patients. There are few data concerning fertility following abdominal myomectomy in patients over the age of 38. PATIENTS AND METHODS: Retrospective study of a case series. Assessment of reproductive outcome after abdominal myomectomy among patients older than 38 years. RESULTS: Abdominal myomectomy was performed on 34 patients aged over 38 during. Among these patients, 25 (74%) were contacted and 15 (60%) tried to obtain a pregnancy. Seven patients (46%) needed a new intervention. Five patients (33%) required intra-uterine insemination or in vitro fertilization and embryo transfer postoperatively. Three patients obtained a pregnancy and two (13%) had a delivery. All pregnancies were obtained spontaneously. None infertile or nulliparous woman before surgery became pregnant postoperatively. CONCLUSION: After 38 years old, nulliparity and infertility before abdominal myomectomy seem to be a factor of poor prognostic to become pregnant after surgery.


Subject(s)
Fertility , Leiomyoma/surgery , Obstetric Surgical Procedures/methods , Uterine Neoplasms/surgery , Adult , Embryo Transfer , Female , Fertilization in Vitro , Humans , Hysterotomy/methods , Infertility, Female/epidemiology , Insemination, Artificial , Parity , Pregnancy , Prognosis , Retrospective Studies , Treatment Outcome
5.
Zoonoses Public Health ; 57(7-8): e65-70, 2010 Dec.
Article in English | MEDLINE | ID: mdl-20163572

ABSTRACT

Echinococcus multilocularis is highly endemic in red foxes in southern Belgium (region of Wallonia), especially in the higher located forested areas. The north of Belgium, including the regions of Flanders and Brussels, is more urbanized and has been colonized entirely by red foxes since the 1980s. A temperospatial analysis of compiled epidemiological data from 1996 to 2003 predicted a northwest spread of the cestode from Wallonia and the Netherlands towards Flanders and Brussels (Prev. Vet. Med. 2006, 76, 137-150). In 2007-2008, none of 187 examined foxes from the north tested positive (<2.8%, α = 0.01), compared to 1.7% in 1996-1999. This suggests that the parasite is not emerging in the examined area and the endemic region has not significantly extended northwest during the last decade. The possible reasons are discussed in the article, including the relatively low altitude, milder climate or low abundance of suitable intermediate hosts. The low prevalence in foxes and the generally low infection rate in humans imply that the risk for public health in Flanders and Brussels is limited anno 2007-2008.


Subject(s)
Communicable Diseases, Emerging/veterinary , Echinococcosis/veterinary , Echinococcus multilocularis/isolation & purification , Foxes/parasitology , Animals , Belgium/epidemiology , Communicable Diseases, Emerging/epidemiology , Echinococcosis/epidemiology , Echinococcosis/parasitology , Echinococcosis/transmission , Humans , Parasitic Diseases, Animal/epidemiology , Prevalence , Public Health
6.
Int J Pediatr Otorhinolaryngol ; 70(4): 689-96, 2006 Apr.
Article in English | MEDLINE | ID: mdl-16226319

ABSTRACT

OBJECTIVE: The purpose of the study is to present the results of cochlear implantation in case of deafness involving mutations in the OTOF gene. This form of deafness is characterized by the presence of transient evoked otoacoustic emissions (TEOAE). In cases of profound deafness with preserved TEOAE, two main etiologies should be considered: either an auditory neuropathy (a retrocochlear lesion) or an endocochlear lesion. It is essential to differentiate these two entities with regards to therapy and screening. PATIENTS: We report two children who presented with profound prelingual deafness, confirmed by the absence of detectable responses to auditory evoked potentials (AEP), associated with the presence of bilateral TEOAE. Genetic testing revealed mutations in OTOF, confirming DFNB9 deafness. Both patients have been successfully implanted (with a follow-up of 18 and 36 months, respectively). MAIN OUTCOME MEASURES: Clinical (oral production, closed and open-set words and sentences list, meaningful auditory integration scale), audiometric evaluation (TEOAE, AEP) before and after implantation, and neural response telemetry (NRT). RESULTS: Both patients present a good quality of clinical responses and electrophysiological tests after implantation, indicating satisfactory functioning of the auditory nerve. This confirms the endocochlear origin of DFNB9 and suggests that these mutations in OTOF lead to functional alteration of inner hair cells. CONCLUSION: In the absence of a context of neurological syndrome, the combination of absent AEP and positive TEOAE should lead to a genetic screening for mutations in OTOF, in order to undertake the appropriate management.


Subject(s)
Cochlear Implantation , DNA/analysis , Evoked Potentials, Auditory, Brain Stem/physiology , Hearing Loss, Sensorineural/genetics , Hearing Loss, Sensorineural/surgery , Membrane Proteins/genetics , Mutation , Otoacoustic Emissions, Spontaneous , Audiometry , Child, Preschool , DNA Mutational Analysis , Female , Hearing Loss, Sensorineural/congenital , Humans , Infant , Phenotype
7.
Otol Neurotol ; 26(4): 748-54, 2005 Jul.
Article in English | MEDLINE | ID: mdl-16015179

ABSTRACT

AIMS: The purpose of the study was to define boundaries between endocochlear hearing loss and auditory neuropathy in children with congenital profound hearing loss and positive otoacoustic emissions. PATIENT: A child presented with bilateral profound hearing loss, which was confirmed by the absence of evoked auditory potentials at 110 dB and with conserved otoacoustic emissions. The lack of any relevant medical history, a normal neurologic pediatric examination, and the improvement obtained with powerful hearing aids suggested an endocochlear cause. Genetic testing identified mutations in OTOF, responsible for the DFNB9 recessive form of hearing loss. RESULTS: In recent years, cases of children with hearing loss associated with positive otoacoustic emissions have been labeled as "auditory neuropathy." Classically, this form of hearing loss is refractory to the use of hearing aids and cochlear implants. Mutations in OTOF lead to inner hair cells dysfunction, whereas the outer hair cells are initially functionally preserved. As this form of endocochlear hearing loss can be detected at a molecular level, genetic testing can be proposed for cases of nonsyndromic auditory neuropathy, as those children could benefit from cochlear implantation. CONCLUSION: It is advisable to reserve the term "auditory neuropathy" for patients who present hearing loss and conserved otoacoustic emissions in the context of a neurologic syndrome or for children with suggestive perinatal history. In other cases, genetic testing for mutations in OTOF should be carried out.


Subject(s)
Cochlear Diseases/complications , Hearing Loss, Sensorineural/diagnosis , Hearing Loss, Sensorineural/physiopathology , Hearing Loss/diagnosis , Hearing Loss/etiology , Otoacoustic Emissions, Spontaneous , Child, Preschool , Diagnosis, Differential , Genetic Testing , Hearing Loss/genetics , Hearing Loss, Sensorineural/congenital , Humans , Membrane Proteins/genetics , Mutation
9.
S Afr Med J ; 91(9): 755-60, 2001 Sep.
Article in English | MEDLINE | ID: mdl-11680325

ABSTRACT

BACKGROUND: A national survey of the micronutrient status of preschool children in South Africa established that vitamin A deficiency is a significant public health problem, requiring urgent attention. A number of immediate and long-term interventions were recommended, including the introduction of a vitamin A supplementation programme and a food fortification programme. OBJECTIVES: The aim of the study was to assist in the development and implementation of a national vitamin A supplementation programme at primary health care facilities for mothers and children. This was achieved by determining the design, coverage and cost of a national primary health care facility vitamin A supplementation programme. METHODS: Based on an extensive review of the literature, the main components of a primary health care facility vitamin A supplementation programme were identified. The annual, recurrent costs of each of the programme components were estimated for the nine provinces in South Africa. Immunisation coverage rates were used as a proxy for estimating the coverage of the programme. RESULTS: The main components of the programme were identified as: promotion, training, purchase of vitamin A capsules, distribution of vitamin A capsules to primary health care facilities, distribution of capsules to the programme beneficiaries, and monitoring and evaluation. The programme would operate from primary health care facilities and would target all children between 6 and 24 months of age and newly delivered mothers. It was estimated that the programme would cover 74% of children and 95% of postpartum women nationally. The total annual, recurrent cost of the national programme was estimated at R16.4 million. The bulk of the costs would include personnel costs, comprising 68% of the total costs. Other costs included promotion (27%), vitamin A capsules (4%) and training (1%). The cost of the programme would vary significantly by province, but the provinces' average total cost per beneficiary would be similar. CONCLUSION: A primary health care facility vitamin A supplementation programme has been designed and accompanied by an estimated overall cost and coverage for implementation. The findings of the study showed that the programme would be financially feasible and would reach the majority of children under 24 months of age. It is recommended that further research be undertaken to extend the programme to the more 'hard to reach' population using other strategies such as mass immunisation campaigns.


Subject(s)
Primary Health Care/methods , Vitamin A Deficiency/drug therapy , Vitamin A/therapeutic use , Adolescent , Adult , Child , Child, Preschool , Female , Humans , Infant , Nutritional Status , Primary Health Care/economics , South Africa , Vitamin A/economics , Vitamin A Deficiency/economics
10.
Proc Natl Acad Sci U S A ; 97(22): 11692-9, 2000 Oct 24.
Article in English | MEDLINE | ID: mdl-11050197

ABSTRACT

The sensory patches in the ear of a vertebrate can be compared with the mechanosensory bristles of a fly. This comparison has led to the discovery that lateral inhibition mediated by the Notch cell-cell signaling pathway, first characterized in Drosophila and crucial for bristle development, also has a key role in controlling the pattern of sensory hair cells and supporting cells in the ear. We review the arguments for considering the sensory patches of the vertebrate ear and bristles of the insect to be homologous structures, evolved from a common ancestral mechanosensory organ, and we examine more closely the role of Notch signaling in each system. Using viral vectors to misexpress components of the Notch pathway in the chick ear, we show that a simple lateral-inhibition model based on feedback regulation of the Notch ligand Delta is inadequate for the ear just as it is for the fly bristle. The Notch ligand Serrate1, expressed in supporting cells in the ear, is regulated by lateral induction, not lateral inhibition; commitment to become a hair cell is not simply controlled by levels of expression of the Notch ligands Delta1, Serrate1, and Serrate2 in the neighbors of the nascent hair cell; and at least one factor, Numb, capable of blocking reception of lateral inhibition is concentrated in hair cells. These findings reinforce the parallels between the vertebrate ear and the fly bristle and show how study of the insect system can help us understand the vertebrate.


Subject(s)
Drosophila/metabolism , Ear, Inner/embryology , Membrane Proteins/metabolism , Signal Transduction , Animals , Cell Differentiation , Chick Embryo , Drosophila Proteins , Ear, Inner/cytology , Immunohistochemistry , Juvenile Hormones/metabolism , Models, Biological , Receptors, Notch
11.
J Comp Neurol ; 424(3): 509-20, 2000 Aug 28.
Article in English | MEDLINE | ID: mdl-10906716

ABSTRACT

The chicken inner ear is a remarkably complex structure consisting of eight morphologically distinct sensory organs. Unraveling how these sensory organs are specified during development is key to understanding how such a complex structure is generated. Previously, we have shown that each sensory organ in the chicken inner ear arises independently in the rudimentary otocyst based on Bone morphogenetic protein 4 (Bmp4) expression. Here, we compare the expression of Bmp4 with two other putative sensory organ markers, Lunatic Fringe (L-fng) and chicken Serrate1 (Ser1), both of which are components of the Notch signaling pathway. L-fng and Ser1 expression domains were asymmetrically distributed in the otic cup. At this early stage, expression of L-fng is similar to Delta1 (Dl1), in an anteroventral domain apparently corresponding to the neurogenic region, while Ser1 is expressed at both the anterior and posterior poles. By the otocyst stage, the expression of both L-fng and Ser1 largely coincided in the medial region. All presumptive sensory organs, as identified by Bmp4 expression, arose within the broad L-fng- and Ser1-positive domain, indicating the existence of a sensory-competent region in the rudimentary otocyst. In addition, there is a qualitative difference in the levels of expression between L-fng and Ser1 such that L-fng expression was stronger in the ventral anterior, whereas Ser1 was stronger in the dorsal posterior region of this broad domain. This early difference in expression may presage the differences among sensory organs as they arise from this sensory competent zone.


Subject(s)
Bone Morphogenetic Proteins/metabolism , Chick Embryo/metabolism , Ear, Inner/embryology , Glycosyltransferases , Proteins/metabolism , Age Factors , Animals , Apoptosis/physiology , Avian Proteins , Bone Morphogenetic Protein 4 , Calcium-Binding Proteins , Chick Embryo/cytology , Cochlea/cytology , Cochlea/embryology , Cochlea/metabolism , Ear, Inner/cytology , Ear, Inner/metabolism , Intercellular Signaling Peptides and Proteins , Membrane Proteins , Saccule and Utricle/cytology , Saccule and Utricle/embryology , Saccule and Utricle/metabolism , Serrate-Jagged Proteins , Spiral Ganglion/cytology , Spiral Ganglion/embryology , Spiral Ganglion/metabolism , Vestibular Nerve/cytology , Vestibular Nerve/embryology , Vestibular Nerve/metabolism , Vestibule, Labyrinth/cytology , Vestibule, Labyrinth/embryology , Vestibule, Labyrinth/metabolism
12.
Curr Biol ; 10(9): 491-500, 2000 May 04.
Article in English | MEDLINE | ID: mdl-10801437

ABSTRACT

BACKGROUND: Human epidermis is renewed throughout life from stem cells in the basal layer of the epidermis. Signals from the surrounding keratinocytes influence the differentiation of the stem cells, but the nature of the signals is unknown. In many developing tissues, signalling mediated by the transmembrane protein Delta1 and its receptor Notch1 inhibits differentiation. Here, we investigated the role of Delta-Notch signalling in postnatal human epidermis. RESULTS: Notch1 expression was found in all living epidermal layers, but Delta1 expression was confined to the basal layer of the epidermis, with highest expression in those regions where stem cells reside. By overexpressing Delta1 or Delta(T), a truncated form of Delta1, in primary human keratinocytes and reconstituting epidermal sheets containing mixtures of Delta-overexpressing cells and wild-type cells, we found that cells expressing high levels of Delta1 or Delta(T) failed to respond to Delta signals from their neighbours. In contrast, wild-type keratinocytes that were in contact with neighbouring cells expressing Delta1 were stimulated to leave the stem-cell compartment and initiate terminal differentiation after a few rounds of division. Delta1 promoted keratinocyte cohesiveness, whereas Delta(T) did not. CONCLUSIONS: We propose that high Delta1 expression by epidermal stem cells has three effects: a protective effect on stem cells by blocking Notch signalling; enhanced cohesiveness of stem-cell clusters, which may discourage intermingling with neighbouring cells; and signalling to cells at the edges of the clusters to differentiate. Notch signalling in epidermal stem cells thus differs from other progenitor cell populations in promoting, rather than suppressing, differentiation.


Subject(s)
Keratinocytes/cytology , Membrane Proteins/metabolism , Receptors, Cell Surface , Signal Transduction , Stem Cells/cytology , Transcription Factors , Cell Differentiation , Cells, Cultured , Epidermal Cells , Fibroblasts/cytology , Fibroblasts/metabolism , Humans , Intracellular Signaling Peptides and Proteins , Keratinocytes/metabolism , Membrane Proteins/genetics , Receptor, Notch1 , Stem Cells/metabolism
13.
Int Immunol ; 12(2): 177-85, 2000 Feb.
Article in English | MEDLINE | ID: mdl-10653853

ABSTRACT

Signals derived from antigen-presenting cells (APC) influence the functional differentiation of CD4(+) T cells. We report here that Serrate1 (Jagged1), a ligand for the Notch1 receptor, may contribute to the differentiation of peripheral CD4(+) T cells into either helper or regulatory cells. Our findings demonstrate that antigen presented by murine APC overexpressing human Serrate1 induces naive peripheral CD4(+) T cells to become regulatory cells. These cells can inhibit primary and secondary immune responses, and transfer antigen-specific tolerance to recipient mice. Our results show that Notch signalling may help explain 'linked' suppression in peripheral tolerance, whereby tolerance induced to one epitope encompasses all epitopes on that antigen during the course of an immune response.


Subject(s)
CD4-Positive T-Lymphocytes/immunology , Immune Tolerance , Membrane Proteins/metabolism , Signal Transduction , Animals , Antigen-Presenting Cells/immunology , Antigen-Presenting Cells/metabolism , Antigens, Dermatophagoides , Calcium-Binding Proteins , Cells, Cultured , Epitopes/immunology , Female , Gene Expression Regulation/immunology , Glycoproteins/immunology , Humans , Immunity, Cellular , Immunization , Intercellular Signaling Peptides and Proteins , Jagged-1 Protein , Leukocytes, Mononuclear/immunology , Membrane Proteins/genetics , Mice , Ovalbumin/immunology , Rats , Receptors, Notch , Reverse Transcriptase Polymerase Chain Reaction , Serrate-Jagged Proteins
14.
Development ; 125(23): 4645-54, 1998 Dec.
Article in English | MEDLINE | ID: mdl-9806914

ABSTRACT

The sensory patches in the vertebrate inner ear are similar in function to the mechanosensory bristles of a fly, and consist of a similar set of cell types. If they are truly homologous structures, they should also develop by similar mechanisms. We examine the genesis of the neurons, hair cells and supporting cells that form the sensory patches in the inner ear of the chick. These all arise from the otic epithelium, and are produced normally even in otic epithelium cultured in isolation, confirming that their production is governed by mechanisms intrinsic to the epithelium. First, the neuronal sublineage becomes separate from the epithelial: between E2 and E3.5, neuroblasts delaminate from the otocyst. The neuroblasts then give rise to a mixture of neurons and neuroblasts, while the sensory epithelial cells diversify to form a mixture of hair cells and supporting cells. The epithelial patches where this occurs are marked from an early stage by uniform and maintained expression of the Notch ligand Serrate1. The Notch ligand Delta1 is also expressed, but transiently and in scattered cells: it is seen both early, during neuroblast segregation, where it appears to be in the nascent neuroblasts, and again later, in the ganglion and in differentiating sensory patches, where it appears to be in the nascent hair cells, disappearing as they mature. Delta-Notch-mediated lateral inhibition may thus act at each developmental branchpoint to drive neighbouring cells along different developmental pathways. Our findings indicate that the sensory patches of the vertebrate inner ear and the sensory bristles of a fly are generated by minor variations of the same basic developmental program, in which cell diversification driven by Delta-Notch and/or Serrate-Notch signalling plays a central part.


Subject(s)
Ear, Inner/embryology , Embryo, Nonmammalian/physiology , Mechanoreceptors/embryology , Membrane Proteins/genetics , Neurons/cytology , Animals , Calcium-Binding Proteins , Cell Differentiation , Cells, Cultured , Drosophila/embryology , Drosophila Proteins , Ear, Inner/cytology , Embryo, Nonmammalian/cytology , Embryonic Induction , Epithelial Cells/cytology , Epithelium/embryology , Gene Expression Regulation, Developmental , Hair Cells, Auditory/cytology , Hair Cells, Auditory/embryology , Intercellular Signaling Peptides and Proteins , Intracellular Signaling Peptides and Proteins , Jagged-1 Protein , Mechanoreceptors/cytology , Neurons/classification , Neurons/physiology , Receptors, Notch , Serrate-Jagged Proteins
15.
Blood ; 91(11): 4084-91, 1998 Jun 01.
Article in English | MEDLINE | ID: mdl-9596653

ABSTRACT

We examined the expression of two members of the Notch family, Notch-1 and Notch-2, and one Notch ligand, Jagged-1, in hematopoietic cells. Both Notch-1 and Notch-2 were detected in murine marrow precursors (Lin-Sca-1+c-kit+). The Notch ligand, Jagged-1, was not detected in whole marrow or in precursors. However, Jagged-1 was seen in cultured primary murine fetal liver stroma, cultured primary murine bone marrow stroma, and in stromal cell lines. These results indicate a potential role for Notch-Notch ligand interactions in hematopoiesis. To further test this possibility, the effect of Jagged-1 on murine marrow precursor cells was assessed by coculturing sorted precursor cells (Lin-Sca-1+c-kit+) with a 3T3 cell layer that expressed human Jagged-1 or by incubating sorted precursors with beads coated with the purified extracellular domain of human Jagged-1 (Jagged-1(ext)). We found that Jagged-1, presented both on the cell surface and on beads, promoted a twofold to threefold increase in the formation of primitive precursor cell populations. These results suggest a potential use for Notch ligands in expanding precursor cell populations in vitro.


Subject(s)
Hematopoietic Stem Cells/cytology , Membrane Proteins/biosynthesis , Transcription Factors , 3T3 Cells , Animals , Calcium-Binding Proteins , Cell Differentiation , Fibroblasts/metabolism , Humans , Intercellular Signaling Peptides and Proteins , Jagged-1 Protein , Ligands , Membrane Proteins/metabolism , Mice , Protein Binding , Receptor, Notch1 , Receptor, Notch2 , Receptors, Cell Surface/biosynthesis , Receptors, Cell Surface/metabolism , Serrate-Jagged Proteins , Transfection
16.
Curr Biol ; 7(9): 661-70, 1997 Sep 01.
Article in English | MEDLINE | ID: mdl-9285721

ABSTRACT

BACKGROUND: Neurons of the vertebrate central nervous system (CNS) are generated sequentially over a prolonged period from dividing neuroepithelial progenitor cells. Some cells in the progenitor cell population continue to proliferate while others stop dividing and differentiate as neurons. The mechanism that maintains the balance between these two behaviours is not known, although previous work has implicated Delta-Notch signalling in the process. RESULTS: In normal development, the proliferative layer of the neuroepithelium includes both nascent neurons that transiently express Delta-1 (Dl1), and progenitor cells that do not. Using retrovirus-mediated gene misexpression in the embryonic chick retina, we show that where progenitor cells are exposed to Dl1 signalling, they are prevented from embarking on neuronal differentiation. A converse effect is seen in cells expressing a dominant-negative form of Dl1, Dl1(dn), which we show renders expressing cells deaf to inhibitory signals from their neighbours. In a multicellular patch of neuroepithelium expressing Dl1(dn), essentially all progenitors stop dividing and differentiate prematurely as neurons, which can be of diverse types. Thus, Delta-Notch signalling controls a cell's choice between remaining as a progenitor and differentiating as a neuron. CONCLUSIONS: Nascent retinal neurons, by expressing Dl1, deliver lateral inhibition to neighbouring progenitors; this signal is essential to prevent progenitors from entering the neuronal differentiation pathway. Lateral inhibition serves the key function of maintaining a balanced mixture of dividing progenitors and differentiating progeny. We propose that the same mechanism operates throughout the vertebrate CNS, enabling large numbers of neurons to be produced sequentially and adopt different characters in response to a variety of signals. A similar mechanism of lateral inhibition, mediated by Delta and Notch proteins, may regulate stem-cell function in other tissues.


Subject(s)
Membrane Proteins/physiology , Neurons/cytology , Receptors, Cell Surface/physiology , Retina/cytology , Signal Transduction , Stem Cells/cytology , Transcription Factors , Animals , Cell Differentiation/physiology , Cell Division , Chick Embryo , Intracellular Signaling Peptides and Proteins , Morphogenesis , Receptor, Notch1 , Retina/embryology
17.
Contracept Fertil Sex ; 25(6): 470-4, 1997 Jun.
Article in French | MEDLINE | ID: mdl-9280552

ABSTRACT

OBJECTIVE: to compare the acceptability of a new estradiol gel TX 11323 (A) and a transdermal matrix system. METHOD: this randomised open crossed study was conducted on 80 healthy menopausal female volunteers treated successively with 1.5 mg of estradiol per day in gel form (Estreva Gel, Theramex, Monaco) and by a transdermal matrix twice-weekly system delivering 50 micrograms/24 h of estradiol (Oesclim 50, Fournier, Dijon-France). The treatment was applied for 25 days with an interval of 6 days between the 2 administration cycles. Acceptability was evaluated and compared by a self-questionnaire given on D1 and D25 of each therapeutic cycle. RESULTS: the 2 treatments, after 25 days of use, were judged convenient, easy and fast to use by more than 90% of subjects. There was, nevertheless, a significant difference in favour of the gel in respect of the estimation of the "visual aspect" of the treatment, reported skin problems, problems with application technique, as well as discomfort during intimacy found in 11% of cases using the transdermal system. It is noted that 80% of the women consider the gel treatment more feminine (p < 0.001) and that 61.3% prefer this treatment compared to 32.5% preferring the transdermal system studied (p = 0.005). CONCLUSION: this study shows a better acceptability of the estradiol gel TX 11323 (A) compared to that of the transdermal matrix system studied.


Subject(s)
Estradiol/administration & dosage , Estrogen Replacement Therapy/methods , Estrogen Replacement Therapy/psychology , Patient Acceptance of Health Care , Administration, Cutaneous , Cross-Over Studies , Female , Gels , Humans , Middle Aged , Surveys and Questionnaires
18.
Planta Med ; 62(3): 275-7, 1996 Jun.
Article in English | MEDLINE | ID: mdl-8693045

ABSTRACT

Some monoterpenes and their carbonylated products were evaluated for their antibacterial and antifungal properties. The carbonylation of tested monoterpenes was shown to increase the bacteriostatic and fungistatic activities specifically by the contact method. Concerning the killing effects, only (1R,2S,5R)-isopulegol, its carbonylated products, and (R)-carvone showed significant bactericidal activities, particularly against Enterococcus faecium and Escherichia coli above a concentration of 10 microliters/ml. A fungicidal efficiency of (1R,2S,5R)-isopulegol and (R)-carvone against Aspergillus niger was also noted. It seems that the presence of an oxygenated function in the framework increases the antimicrobial properties. However, monoterpenes were more active using a micro-atmosphere method.


Subject(s)
Anti-Infective Agents/pharmacology , Bacteria/drug effects , Terpenes/pharmacology , Anti-Bacterial Agents , Antifungal Agents/pharmacology , Aspergillus niger/drug effects , Candida albicans/drug effects , Enterococcus faecium/drug effects , Escherichia coli/drug effects , Microbial Sensitivity Tests , Pseudomonas aeruginosa/drug effects , Staphylococcus aureus/drug effects , Structure-Activity Relationship
19.
Chest ; 109(2): 414-9, 1996 Feb.
Article in English | MEDLINE | ID: mdl-8620715

ABSTRACT

UNLABELLED: Increased pleural fluid adenosine deaminase (ADA) activity is classically associated with tuberculous pleuritis. However, increased activity can also occur in a number of other diseases and this may negatively affect the diagnostic utility of ADA measurements and decrease its specificity for the diagnosis of tuberculosis (TB). The presence of ADA in pleural fluids reflects the cellular immune response in the pleural cavity and in particularly, the activation of T lymphocytes. Different disease entities are typically associated with the presence of particular types of leukocytes. OBJECTIVE: To determine whether the combined use of ADA activity and differential cell counts would provide a more efficient means for diagnosing tuberculous pleurisy than the use of ADA levels alone. METHODS: Biochemistry, cytology, and microbiology studies were performed on 472 consecutive pleural fluids. ADA and differential cell counts were determined on all exudative effusions. RESULTS: ADA activity in tuberculous effusions was significantly higher than in any other diagnostic group (p < 0.005). At a level of 50 U/L, the sensitivity, specificity, positive predictive value (ppv), negative predictive value (npv), and efficiency for the identification of TB were calculated at 91%, 81%, 84%, 89%, and 86%, respectively. When the additional requirement of a lymphocyte neutrophil ratio of 0.75 or greater was included, the sensitivity, specificity, ppv, npv, and efficiency for the identification of TB were calculated at 88%, 95%, 95%, 88%, and 92%, respectively. CONCLUSION: ADA, especially when combined with differential cell counts and lymphocyte/neutrophil ratios, remains a useful test in the diagnosis tuberculous pleuritis.


Subject(s)
Adenosine Deaminase/metabolism , Clinical Enzyme Tests , Pleural Effusion/enzymology , Tuberculosis, Pleural/diagnosis , Adolescent , Adult , Aged , Aged, 80 and over , Child , Child, Preschool , Female , Humans , Infant , Leukocyte Count , Lymphocyte Count , Male , Middle Aged , Neutrophils , Prospective Studies , Sensitivity and Specificity , Tuberculosis, Pleural/blood
20.
Article in French | MEDLINE | ID: mdl-8926345

ABSTRACT

This randomized, crossed, single-blind study compared the acceptability and drying time of the new estradiol gel TX11323(A) (Estréva Gel, Laboratoire Théramex) to that of a reference gel (CEstrodose, Laboratories Besins-Iscovesco), in two phases. In phase 1, 48 healthy menopausal female volunteers applied 1.5 mg estradiol of each form of estradiol gel on the outer side of the arm for 8 days, with a free period of 7 days between the two treatments. Acceptability, evaluated by self-questionnaire and drying time for the two treatments were noted at day 1 and day 8. The second phase applied only to 16 subjects who followed the same therapeutic protocol, except that this time application was made on the antero-external side of the thighs. Only the subjectively and objectively quantified drying-time was taken into account. A significant difference was found in favor of TX11323(A) gel in terms of the following items: consistency, ease of application and penetration, quantity of gel to apply, sensation of lasting stickness. We note that 68.8% subjects prefer TX11323(A) gel and 27.1% prefer the reference gel (p = 0.001). The timed drying-time for TX11323(A) gel is significantly reduced, 40 to 50% on average depending on the phase, compared to that of the reference gel. The subjective evaluation of the subjects confirms this shorter drying time.


Subject(s)
Estradiol/therapeutic use , Estrogen Replacement Therapy , Patient Acceptance of Health Care , Adult , Aged , Cross-Over Studies , Female , Gels , Humans , Middle Aged , Single-Blind Method , Surveys and Questionnaires
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