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Association between CYP4A11 and EPHX2 genetic polymorphisms and chronic kidney disease progression in hypertensive patients. Nefrologia 2024:S2013-2514(24)00037-3. [PMID: 38448299 DOI: 10.1016/j.nefroe.2024.01.020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2023] [Accepted: 08/06/2023] [Indexed: 03/08/2024] Open
Abstract
BACKGROUND There are evidence indicating that some metabolites of arachidonic acid produced by cytochromes P450 (CYP) and epoxide hydroxylase (EPHX2), such as hydroxyeicosatetraenoic acids (HETEs), epoxyeicosatrienoic acids (EETs) or dihydroxyeicosatrienoic acids (DHETEs), play an important role in blood pressure regulation and they could contribute to the development of hypertension (HT) and kidney damage. Therefore, the main aim of the study was to evaluate whether the genetic polymorphisms of CYP2C8, CYP2C9, CYP2J2, CYP4F2, CYP4F11 and EPHX2, responsible for the formation of HETEs, EETs and DHETEs, are related to the progression of impaired renal function in a group of patients with hypertension. METHODS 151HT patients from a hospital nephrology service were included in the study. Additionally, a group of 87 normotensive subjects were involved in the study as control group. For HT patients, a general biochemistry analysis, estimated glomerular filtration rate and genotyping for different CYPs and EPHX2 variant alleles was performed. RESULTS CYP4A11 rs3890011, rs9332982 and EPHX2 rs41507953 polymorphisms, according to the dominant model, presented a high risk of impaired kidney function, with odds ratios (OR) of 2.07 (1.00-4.32; P=0.049) 3.02 (1.11-8.23; P=0.030) and 3.59 (1.37-9.41; P=0.009), respectively, and the EPHX2 rs1042032 polymorphism a greater risk according to the recessive model (OR=6.23; 95% CI=1.50-25.95; P=0.007). However, no significant differences in allele frequencies between HT patients and in normotensive subjects for any of the SNP analysed. In addition, the patients with diagnosis of dyslipidemia (n=90) presented higher frequencies of EPHX2 K55R (rs41507953) and *35A>G (rs1042032) variants than patients without dyslipidemia, 4% vs. 14% (P=0.005) and 16 vs. 27% (P=0.02), respectively. CONCLUSIONS In this study has been found higher odds of impaired renal function progression associated with rs3890011 and rs9332982 (CYP4A11) and rs41507953 and rs1042032 (EPHX2) polymorphisms, which may serve as biomarkers for improve clinical interventions aimed at avoiding or delaying, in chronic kidney disease patients, progress to end-stage kidney disease needing dialysis or kidney transplant.
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Clinical implementation of a multiplex PCR detection method for HPV causing plantar warts and genotype distribution in different geographical areas of Spain. Heliyon 2024; 10:e23550. [PMID: 38187313 PMCID: PMC10767125 DOI: 10.1016/j.heliyon.2023.e23550] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2023] [Revised: 11/02/2023] [Accepted: 12/06/2023] [Indexed: 01/09/2024] Open
Abstract
Human papillomavirus is the ethological agent of various tumors, including plantar warts as one of the most frequent clinical presentations. Diagnosis of these warts continues to be mainly clinical, and a significant incidence of misdiagnosis leads to inadequate treatment. The aim of this study is to implement and validate a multiplex PCR detection method in the clinical setting to detect HPV in samples and to study genotype distribution in Spain to improve future molecular diagnostics. Viral DNA was extracted from 128 samples of clinically suspected plantar warts from various locations in Spain. A multiplex PCR was run alongside internal controls, and amplicons were processed for sequencing and HPV genotyping. The method was validated by assessing both inter- and intra-run repeatability. The PCR detection method returned 81.2 % (n = 104) positive results in the samples tested. Inter- and intra-run repeatability tests showed excellent intra-run agreement (κ = 1.00, p < 0.001) and good inter-run agreement (κ = 0.737, p < 0.001). The most frequent HPV type was HPV1, followed by HPV27, showing a statistical difference between the distribution of HPV genotypes in different areas of Spain. Clinical implementation of a DNA PCR detection method for plantar warts can avoid 18.8 % of unnecessary treatments in doubtful cases, and the method is reliable and validated for the purpose. HPV types show an asymmetric geographical distribution that should be considered for diagnosis and treatment.
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Diagnostic techniques in HPV infections and the need to implement them in plantar lesions: A systematic review. Expert Rev Mol Diagn 2021; 21:1341-1348. [PMID: 34752720 DOI: 10.1080/14737159.2021.2004889] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
INTRODUCTION Human papillomavirus has been reported as the etiological cause of most cervical cancers and other potentially malignant lesions. It also affects other areas, producing benign tumors on the skin. Plantar warts are a common problem found in clinical practice and share signs and symptoms with other dermatological conditions. Diagnosis of HPV infection remains a hot topic in research. METHOD The present work systematically reviews the literature on the diagnostic techniques available in the clinical setting for any type of lesion produced by the virus and compares the techniques identified to those found in use for foot lesions. RESULTS Results showed a variety of diagnostic methods, including molecular techniques, which exhibit more sensitivity than other methods but are less frequently applied to plantar lesions, where visual inspection is the most frequent method but can lead to errors. CONCLUSION The techniques identified need to be applied to plantar lesions to improve differential diagnosis in clinical practice. EXPERT OPINION Research will continue to grow and a proper diagnostic technique for plantar lesions will be available in the near future.
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Solubilization in vitro of tea tree oil and first results of antifungal effect in onychomycosis. ENFERMEDADES INFECCIOSAS Y MICROBIOLOGIA CLINICA (ENGLISH ED.) 2021; 39:395-398. [PMID: 34334327 DOI: 10.1016/j.eimce.2021.07.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2020] [Accepted: 06/19/2020] [Indexed: 06/13/2023]
Abstract
INTRODUCTION Onychomycosis is the main cause of nail alteration. Hepatotoxicity, interference and low adherence to pharmacological treatment are associated. Therefore, our objective was to assess the in vitro effectiveness of tea tree essential oil (less harmful) against main causative agents of these infections. MATERIAL AND METHODS Thrichophyton rubrum and Thrichophyton mentagrophytes were isolated and inoculated at a concentration of 3 × 105 CFU/mL in potato agar dextrose and tea tree essential oil at different concentrations to assess its effect by counting colony forming units and radial growth. RESULTS Trichophyton rubrum growth inhibition was obtained at concentrations higher than 0.04% of the essential tea tree oil (p = 0.004). In the case of Thrichophyton mentagrophytes, inhibition was obtained at 0.02% (p = 0.017), and even complete inhibition at a final concentration of the oil at 0.07%. CONCLUSIONS Tea tree essential oil inhibits the in vitro growth of the fungus and may be a less harmful alternative to the onychomycosis treatment.
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Identification of Fungi Involved in Onychomycosis in Patients of a Spanish Rural Area. J Fungi (Basel) 2021; 7:jof7080623. [PMID: 34436162 PMCID: PMC8398180 DOI: 10.3390/jof7080623] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2021] [Revised: 07/26/2021] [Accepted: 07/30/2021] [Indexed: 11/16/2022] Open
Abstract
Onychomycosis is one of the most frequent reasons for visiting podiatrist clinics. Complementary tests and the accurate identification of the infectious agents are key issues for a successful treatment of onychomycosis. This is particularly important when lifestyle, age and immunodepressed patients increase the prevalence of non-dermatophyte fungal infection. In this paper, we describe issues related to onychomycosis prevalence in a population of patients, mostly with rural lifestyles, visiting a podiatry clinic in a rural area of Spain. A total of 51 cases were studied with an average age of 65.96 ± 21.28 years (the youngest being 16 years and the oldest being 95 years). Fungal agents were isolated using conventional sampling and microbiological culture techniques. The results obtained with these techniques were compared with the results obtained with a direct methodology using molecular biology, by PCR and nucleotide sequencing of the ITS-5.8S rDNA fragment. The classical culture methodology confirmed the infection in 76.5% of the samples (n = 39), while the PCR confirmed the infection in 84.3% (n = 51) of the nails, although the difference between these results did not show statistical significance (p = 0.388). We found a high variability in agents, with more yeasts than dermatophytes as etiological agents of onychomycosis. However, only among individuals older than 65 years, was the difference between yeasts (82%) and dermatophytes (18%) was statistically significant (p = 0.004). Among the agents of non-dermatophyte onychomycosis, we found predominantly fungi (yeasts) of the Candida genus, interestingly with no isolates of Candida albicans, and moulds of the Aspergillus genus.
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Fractional modeling of flexural behavior of toenail plates: First step for clinical purposes. Med Eng Phys 2021; 90:23-32. [PMID: 33781477 DOI: 10.1016/j.medengphy.2021.01.006] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Revised: 12/04/2020] [Accepted: 01/19/2021] [Indexed: 01/13/2023]
Abstract
This work presents an identification procedure of flexural behavior of toenail plates in twenty subjects with no history of feet or nail injury as of in-vivo measurements. In particular, four different mechanical models are considered to describe such properties, ranging from the pure elastic to viscoelastic behavior, the latter from the classical and fractional points of view. The quality of the adjustment of each model is examined by a group of performance indices. Experimental data show that the best identification is achieved by the fractional order viscoelastic model for all subjects. These novel results in modeling flexural behavior of toenails are consistent with the published literature suggesting that viscoelastic materials may be successfully modeled with derivatives of fractional order. This could contribute, together with additional variables, to help health professionals, and more especially podiatrists, to have reliable and quantitative measures of the nail flexural behavior which can be susceptible of treatment or for prevention.
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Predictive Model of Nail Consistency Using Scanning Electron Microscopy with Energy-Dispersive X-Ray. BIOLOGY 2021; 10:biology10010053. [PMID: 33445794 PMCID: PMC7828269 DOI: 10.3390/biology10010053] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Accepted: 01/11/2021] [Indexed: 11/22/2022]
Abstract
Simple Summary Scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDS) is a useful technique to analyse elemental composition in the nail plate. The dorsal, intermediate, and ventral layers are differentiated by the levels of the elements present in each layer. The level of calcium in the dorsal layer is the main predictive variable in calculating the predictive model of consistency. This model will provide further knowledge of the factors that determine nail consistency in individuals and help health professionals to better understand nail characteristics and objectively determine nail consistency. Abstract The nail plate is made up of tightly packed keratin-rich cells. Factors such as the special distribution of the intermediate filaments in each layer (dorsal, intermediate, and ventral), the relative thickness of the layers, and their chemical composition define the characteristics of each nail. The main objective of this study is to determine nail consistency by calculating a predictive model based on elemental composition analysis using scanning electron microscopy. Nail consistency was determined in 57 participants (29 women and 28 men) in two age groups (young people and adults). Elemental composition was analysed in each layer using scanning SEM-EDS, and nail plate thickness was measured by image analysis. A total of 12 elements were detected in nail plates, of which carbon, nitrogen, phosphorus, sulphur, and calcium showed significant differences between layers (p-values ≤ 0.01). The level of calcium in the dorsal layer was the main predictive variable in calculating the predictive model of consistency, with 75.4% correctly classified cases. Elemental analysis in each layer of the nail plate by SEM-EDS can be used to develop a predictive model of nail consistency that will help health professionals to objectively determine nail consistency.
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First-year health degree students in the dissection room: Analysis of adaptation to practical classes. Ann Anat 2020; 233:151603. [PMID: 32979527 DOI: 10.1016/j.aanat.2020.151603] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Revised: 08/04/2020] [Accepted: 08/26/2020] [Indexed: 11/30/2022]
Abstract
Human anatomy is a core subject that students of all health degrees are required to pass. Practical classes with human cadavers are a widely used educational resource in medicine, but are less frequent in other health degrees. Determining how first-year podiatry, nursing, and physiotherapy students cope with human anatomy practical classes and identifying the presence of physical reactions and possible causes of distress they experience in the dissection room are essential steps in designing a guidance plan to address students' needs. A questionnaire was distributed to 172 first-year students in non-medical health degrees immediately after their first visit to the dissection room. The questionnaire comprised 29 Yes/No questions to determine students' physical reactions, causes of distress and coping methods. The most frequent physical reactions were disgust, uneasiness and nausea. The main causes of distress were the smell of the cadavers, the smell of the dissection room and the sight of the cadavers. The coping methods used were being with friends, eating before the practical class and practicing beforehand with anatomical atlases and CDs. No significant differences were found between gender and the three variables analyzed (number of physical reactions, number of causes of distress and number of coping methods) (p-value >0.216), although differences were found between the type of health degree and the number of physical reactions and causes of distress (p-values = 0.028 and 0.001, respectively).
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Solubilization in vitro of tea tree oil and first results of antifungal effect in onychomycosis. Enferm Infecc Microbiol Clin 2020; 39:S0213-005X(20)30245-7. [PMID: 32912657 DOI: 10.1016/j.eimc.2020.06.013] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2020] [Revised: 06/16/2020] [Accepted: 06/19/2020] [Indexed: 11/17/2022]
Abstract
INTRODUCTION Onychomycosis is the main cause of nail alteration. Hepatotoxicity, interference and low adherence to pharmacological treatment are associated. Therefore, our objective was to assess the in vitro effectiveness of tea tree essential oil (less harmful) against main causative agents of these infections. MATERIAL AND METHODS Trichophyton rubrum and Trichophyton mentagrophytes were isolated and inoculated at a concentration of 3x105 CFU / mL in potato agar dextrose and tea tree essential oil at different concentrations to assess its effect by counting colony forming units and radial growth. RESULTS Trichophyton rubrum growth inhibition was obtained at concentrations higher than 0.04% of the essential tea tree oil (p = 0.004). In the case of Trichophyton mentagrophytes, inhibition was obtained at 0.02% (p = 0.017), and even complete inhibition at a final concentration of the oil at 0.07%. CONCLUSIONS Tea tree essential oil inhibits the in vitro growth of the fungus and may be a less harmful alternative to the onychomycosis treatment.
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Prevalence of Potential Drug-Drug Interaction Risk among Chronic Kidney Disease Patients in a Spanish Hospital. Pharmaceutics 2020; 12:pharmaceutics12080713. [PMID: 32751436 PMCID: PMC7463737 DOI: 10.3390/pharmaceutics12080713] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 07/17/2020] [Accepted: 07/28/2020] [Indexed: 01/08/2023] Open
Abstract
Chronic kidney disease (CKD) is a major health problem worldwide and, in Spain, it is present in 15.1% of individuals. CKD is frequently associated with some comorbidities and patients need to be prescribed multiple medications. Polypharmacy increases the risk of adverse drug reactions (ADRs). There are no published studies evaluating the prevalence of potential drug–drug interactions (pDDIs) among CKD patients in any European country. This study was aimed to determine the prevalence, pattern, and factors associated with pDDIs among CKD patients using a drug interactions program. An observational cross-sectional study was carried out at Plasencia Hospital, located in Spain. Data were collected among patients with CKD diagnoses and pDDIs were assessed by the Lexicomp® Drug Interactions platform. Data were obtained from 112 CKD patients. A total number of 957 prescribed medications were acknowledged, and 928 pDDIs were identified in 91% of patients. Age and concomitant drugs were significantly associated with the number of pDDIs (p < 0.05). According to the results, the use of programs for the determination of pDDIs (such as Lexicomp®) is recommended in the clinical practice of CKD patients in order to avoid serious adverse effects, as is paying attention to contraindicated drug combinations.
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Prevalence of foot disorders according to chronic kidney disease stage. J Ren Care 2020; 47:17-26. [PMID: 33216453 DOI: 10.1111/jorc.12342] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Revised: 06/15/2020] [Accepted: 07/01/2020] [Indexed: 11/29/2022]
Abstract
BACKGROUND Chronic kidney disease (CKD) is a public health disease that affects 15.1% of the adult population. Although a high prevalence (94.1%) of skin disorders has been detected in people on haemodialysis or with advanced CKD, few studies have analysed foot disorders at initial CKD stages. OBJECTIVES To analyse the prevalence of foot disorders according to CKD stage. PARTICIPANTS A total of 209 people with a mean age of 73.2 ± 13.8 years (52.0% women) in the nephrology department of Virgen del Puerto Hospital, Plasencia (Spain) were examined from January 2018 to April 2019. MEASUREMENTS CKD stages were determined by nephrologists according to the Kidney Disease Improving Global Outcomes Guideline. An expert podiatrist identified foot disorders. Data were statistically treated with the IBM SPSS Statistics. Comparisons between variables were analysed by the χ2 test or Fisher's exact test, with a significance level of less than 5%. RESULTS The prevalence of foot disorders was high for skin disorders (97.6% dermatopathies and 66.0% keratopathies), nail disorders (98.5% onychopathies) and toe deformities (97.1%). People at initial and intermediate stages presented more keratopathies (hyperkeratosis at G1 and G3a and pinch callus at G3a). Stage G1 showed fewer changes in nail colour and half and half nails. Stage G4 showed more claw toes and hematoma and stage G5 more Beau's lines, changes in skin colour, hematomas and thin shiny skin. CONCLUSIONS The high prevalence of foot disorders detected in people with CKD requires specific and personalised professional care to relieve symptoms and avoid complications, helping to improve the quality of life of people with this condition.
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Relation Between Nail Consistency and Incidence of Ingrown Toenails in Young Male Runners. J Am Podiatr Med Assoc 2017; 107:137-143. [PMID: 28394683 DOI: 10.7547/15-121] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
BACKGROUND This study examines the possible influence of factors such as nail shape and consistency, sex, and sports activity on the development of the most common nail disorders in a population of young people. METHODS The nail plates of 140 young people (66 females and 74 males) were studied. Of these 140 participants, 72 were runners who trained more than 10 hours a week and competed regularly, and 68 did not habitually do any sports activity. Nail shape, consistency, and disorders were examined, taking into account the sex of the participants and their sports activity. RESULTS A hard nail consistency is more frequent in runners (74.4%) than in people who do no sports activity (25.6%). In contrast, a soft nail consistency is more prevalent in participants who do no sports activity (70%) than in runners (30%). It was also shown that onychocryptosis is related to sex, as females had a higher prevalence of this nail disorder (57.8%, P = .016). However, young male runners showed the highest and most significant percentage of the presence of onychocryptosis (74.1%; P = .002). CONCLUSIONS Sports activity by young male runners whose nails have a hard consistency seems to be directly related to the high incidence of onychocryptosis in this population.
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Differential, age-dependent MEK-ERK and PI3K-Akt activation by insulin acting as a survival factor during embryonic retinal development. Dev Neurobiol 2007; 67:1777-88. [PMID: 17659595 DOI: 10.1002/dneu.20554] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Programmed cell death is a genuine developmental process of the nervous system, affecting not only projecting neurons but also proliferative neuroepithelial cells and young neuroblasts. The embryonic chick retina has been employed to correlate in vivo and in vitro studies on cell death regulation. We characterize here the role of two major signaling pathways, PI3K-Akt and MEK-ERK, in controlled retinal organotypic cultures from embryonic day 5 (E5) and E9, when cell death preferentially affects proliferating neuroepithelial cells and ganglion cell neurons, respectively. The relative density of programmed cell death in vivo was much higher in the proliferative and early neurogenic stages of retinal development (E3-E5) than during neuronal maturation and synaptogenesis (E8-E19). In organotypic cultures from E5 and E9 retinas, insulin, as the only growth factor added, was able to completely prevent cell death induced by growth factor deprivation. Insulin activated both the PI3K-Akt and the MEK-ERK pathways. Insulin survival effect, however, was differentially blocked at the two stages. At E5, the effect was blocked by MEK inhibitors, whereas at E9 it was blocked by PI3K inhibitors. The cells which were found to be dependent on insulin activation of the MEK-ERK pathway at E5 were mostly proliferative neuroepithelial cells. These observations support a remarkable specificity in the regulation of early neural cell death.
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Abstract
Programmed cell death occurs during both early and late neural development. The mechanisms for the regulation and execution of the early cell death as well as its developmental role are still not fully understood. In this work we have studied the early programmed cell death in the retinal neuroepithelium. Apoptotic cells were selectively located around the optic nerve head in the retinal neuroepithelium of 2- to 6-day-old chick embryos. TUNEL-positive cells and cells which were immunostained for activated caspase-3 showed overlapping distributions suggesting that caspase-3 is involved in the early retinal cell death. Caspase-3 involvement in early retinal cell death was also demonstrated by in vivo treatment with caspase inhibitors z-DEVD-fmk and Boc-D-fmk. After 6 h of treatment, the number of TUNEL-positive cells was reduced by 50%. Sustained treatments (20 h) resulted in a slight widening in the central part of the neural retina but the retinal ganglion cell axons maintained their organization and navigation towards the optic fissure. The most prominent result after inhibition of cell death was an increase in the number of retinal ganglion cells which also produced an enlargement of the ganglion cell layer and an increased number of ganglion cell axons. In conclusion, our results show that caspase-dependent programmed cell death occurs in the embryonic chick retina and that it plays a role to modulate the generation of retinal ganglion cells.
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Overlapping and specific patterns of GDNF, c-ret and GFR alpha mRNA expression in the developing chicken retina. Mech Dev 2002; 114:161-5. [PMID: 12175504 DOI: 10.1016/s0925-4773(02)00045-x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
GDNF and the GDNF receptors, c-Ret, GFR alpha 1 and 2 mRNA is expressed in the developing chicken retina. GDNF labelling was mainly found in embryonic day 4-5 retina but weak labelling could also be found over scattered retinal cells at later stages. c-ret labelling was found over ganglion cells, amacrine and horizontal cells; the preferred GDNF receptor (GFR alpha 1) over amacrine and horizontal cells; and the less preferred GDNF receptor (GFR alpha 2) over ganglion cells, amacrine cells and photoreceptors.
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Abstract
Proliferation, cell death and differentiation occur simultaneously in developing retina and are precisely orchestrated. We have studied the effects of biotin (vitamin H) on early retinal development. In vivo administration of biotin to early embryonic chick eyes at moderately elevated levels induced malformations, affecting retina and lens structures. The effects were strictly age dependent and were only found in embryos treated between Hamburger and Hamilton stage 14-17. Biocytin, a biotin analogue, mimicked biotin effects, while avidin could block the effects. At the cellular level, biotin did not affect proliferation but reduced apoptosis. These results suggest that an adequate content of biotin and a precise regulation of retinal cell death are required for the correct morphogenesis of the eye.
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Nerve growth factor is expressed by postmitotic avian retinal horizontal cells and supports their survival during development in an autocrine mode of action. Development 2001; 128:471-9. [PMID: 11171331 PMCID: PMC2710126 DOI: 10.1242/dev.128.4.471] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Cell death in the developing retina is regulated, but so far little is known about what factors regulate the cell death. Several neurotrophic factors and receptors, including the neurotrophins and Trk receptors, are expressed during the critical time. We have studied the developing avian retina with respect to the role of nerve growth factor (NGF) in these processes. Our starting point for the work was that NGF and its receptor TrkA are expressed in a partially overlapping pattern in the inner nuclear layer of the developing retina. Our results show that TrkA and NGF-expressing cells are postmitotic. The first NGF-expressing cells were found on the vitreal side of the central region of E5.5-E6 retina. This pattern changed and NGF-expressing cells identified as horizontal cells were later confined to the external inner nuclear layer. We show that these horizontal cells co-express TrkA and NGF, unlike a subpopulation of amacrine cells that only expresses TrkA. In contrast to the horizontal cells, which survive, the majority of the TrkA-expressing amacrine cells die during a period of cell death in the inner nuclear layer. Intraocular injections of NGF protein rescued the dying amacrine cells and injection of antisense oligonucleotides for NGF that block its synthesis, caused death among the TrkA-expressing horizontal cells, which normally would survive. Our results suggest that NGF supports the survival of TrkA expressing avian horizontal cells in an autocrine mode of action in the retina of E10-E12 chicks. The cells co-express TrkA and NGF and the role for NGF is to maintain the TrkA-expressing horizontal cells. The TrkA-expressing amacrine cells are not supported by NGF and subsequently die. In addition to the effect on survival, our results suggest that NGF plays a role in horizontal cell plasticity.
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Vertical regulation of En-2 expression and eye development by FGFs and BMPs. JOURNAL OF CRANIOFACIAL GENETICS AND DEVELOPMENTAL BIOLOGY 2000; 20:64-75. [PMID: 11100736] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/15/2023]
Abstract
The formation of the midbrain region depends mainly on the activity of a signalling center located in the isthmus region, on the border between the prospective mesencephalon and metencephalon. FGF-8 has been proposed as a signalling molecule responsible for this specification because of its expression pattern and its ability to elicit duplication of the midbrain region when expressed ectopically in the neuroepithelium. Here we present evidence that members of the FGF family of growth factors when released in the cephalic mesenchyme are able to extend the expression of the mesencephalic marker En-2 to both the anterior and the posterior regions of its original landmark. This alteration in the expression pattern of En-2 is not accompanied by a significant alteration in the later development of the midbrain-cerebellar anlage, although the eye development is severely altered. Members of the bone morphogenetic protein family ectopically released from the mesenchyme down-regulate the expression of En-2 and also have an effect on the development of the eye. These results demonstrate that growth factor molecules produced in the mesenchyme (vertical signalling) participate in the correct establishment of the antero-posterior patterning of the cephalic nervous system during development.
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Monoclonal antibody GL1 and its possible involvement in the morphogenesis of the otic vesicle. Anat Rec (Hoboken) 1999; 254:288-97. [PMID: 9972814 DOI: 10.1002/(sici)1097-0185(19990201)254:2<288::aid-ar15>3.0.co;2-b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
In a previous study, a monoclonal antibody (MAB) named GL1 was identified that is expressed in a precise pattern during gastrulation and early neurulation stages in chick embryos. In this article we have further investigated the expression pattern of this MAB in the chick embryo. GL1 antigen is present in several organs that seem not to be related developmentally. Among them, GL1 is present during the early steps of the otic placode formation, in the pharyngeal endoderm, in some neural crest cells, in the somites, and in the ventricular surface of the nervous system. The distribution in the nervous system is well patterned with two broad lines of expression in the ventricular side of the metencephalic region, a unique and centered expression in the border between the metencephalon and the myelencephalon and again in two lines running along the myelencephalon and the rostral spinal cord. Additionally, GL1 can be induced by members of the FGF family, and we have used this system to elucidate its role in otic placode formation. The results obtained reveal that GL1 can be a useful marker for the study of developmental processes in the endoderm, the otic anlage, and the apical surface of the nervous system. Biochemical analysis of the antigen recognized by this MAB must be carried out to elucidate the molecular nature of the antigen.
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Members of the fibroblast growth factors induce ectopic neural plate formation in cultured chick embryos. THE INTERNATIONAL JOURNAL OF DEVELOPMENTAL BIOLOGY 1996; Suppl 1:105S-106S. [PMID: 9087717] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
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