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2.
J Biol Regul Homeost Agents ; 35(2 Suppl. 1): 351-356, 2021.
Article in English | MEDLINE | ID: mdl-34281332

ABSTRACT

HPVs are a large and varied group of viruses capable of infecting both animals and humans. They have evolved together with their respective hosts and are isolable in different and numerous species of birds, reptiles, marsupials and mammals. The present study aims to analyze and compare the epidemiological aspects of 251 HPV-associated benign lesions treated with three different surgical approaches. Between January 2004 and December 2019, 251 HPV-associated benign lesions (papillomas and / or condylomas) were treated at the Center of Medicina e Patologia Orale Laser Assistita of the University of Parma. After loco-regional anesthesia, the excisional biopsy was performed with A): 15C scalpel blade; B): molecular quantum resonance scalpel (RQM); C): Nd: YAG laser (1064 mn, 3.5W, 70Hz). The epidemiological analysis considered: gender, age, site of the lesion, surgical technique and recurrence. Our study did not show substantial differences in gender prevalence and the mean age of 50 years (minimum 8 years, maximum 85 years). Our study showed that HPV-associated lesions are localized in almost half of patients (47.9%) on the tongue or hard palate, less frequently on the cheeks (16.3%) and on the upper or lower lip (14,4) and in less than 10% of patients in the soft palate. Our study showed a low relapse rate (3%) for all three therapeutic approaches used, meaning that the cold blade, RQM scalpel and Nd: YAG laser can be successfully used to treat lesions associated with HPV, the laser approach has proved to be slightly more effective: probably thanks to the radicalization obtained through carbonization of the biopsy surrounding tissues. Since a small group of these viruses are the responsible agent of several types of human cancers (including squamous cell carcinoma of the oral cavity), early screening and treatment of HPV-associated lesions is essential to prevent the development of oncological diseases.


Subject(s)
Alphapapillomavirus , Laser Therapy , Lasers, Solid-State , Animals , Humans , Lasers, Solid-State/therapeutic use , Middle Aged , Neoplasm Recurrence, Local , Papillomaviridae
3.
J Biol Regul Homeost Agents ; 35(2 Suppl. 1): 357-364, 2021.
Article in English | MEDLINE | ID: mdl-34281333

ABSTRACT

Surgical techniques of soft and hard oral tissues highly benefited from new technologies such as the Quantic Molecular Resonance (QMR) lancet, the Neodymium-doped Yttrium Aluminum Garnet (Nd:YAG) laser and the Erbium-doped Yttrium Aluminum Garnet (Er:YAG) laser. Increasingly, these technologies replace scalpel, conventional electrosurgery and traditional rotary surgery instruments due to their proven advantages. Features such as reduction of the surgical time, more efficient bleeding control resulting in higher intra-operative visibility and improvement of postoperative course with better Quality of Life score (QoL) are highlighted in numerous studies published in the literature. The thermal rise of tissues during surgical incision, performed with other instruments rather than traditional cold blade scalpels, is not to be ignored by the operator and it must take into consideration first when choosing the surgical instrument and then throughout all the surgical act. Auto-fluorescence (AF) is a property possessed by every cell that exposed to a specific wavelength can absorbance or reflect with peculiar characteristics and its direct examination has been proposed as a non-invasive visual tool for investigation of suspicious changes in oral mucosa. At the limit of our knowledge, few studies have been published in the literature regarding tissue's temperature variations and the interest in Infra-Red temperature detection has been shown in various medicine fields and none of published studies investigated the possible correlation between temperature raise and AF variations. This ex vivo study aims to analyse and compare through the use of a thermal imaging camera and simultaneous detection of AF, the possible correlation between temperature increase and auto-fluorescence.


Subject(s)
Laser Therapy , Lasers, Solid-State , Fluorescence , Quality of Life , Surgical Instruments , Temperature
4.
Rev Epidemiol Sante Publique ; 69(3): 134-144, 2021 06.
Article in English | MEDLINE | ID: mdl-33965268

ABSTRACT

BACKGROUND: The objective of this study was to evaluate the impact of the interaction between body dissatisfaction and gender on eating disorders (restrained eating, binge eating, orthorexia nervosa, and emotional eating) among a sample of Lebanese adults. METHODS: This cross-sectional study, conducted between January and May 2018, enrolled 811 participants selected randomly from all Lebanese Mohafazat. The mean age of the participants was 27.6±11.8 years. The majority were females (66.5%), had a high level of education (73.2%), and low income (77.9%). This study used the following scales: body dissatisfaction subscale of the Eating Disorder Inventory-second version, binge eating scale, Dutch restrained eating scale, orthorexia nervosa scale (ORTHO-15 scale), emotional eating scale, perceived stress scale, Hamilton Anxiety Rating Scale, and Hamilton Depression Rating Scale. RESULTS: Body dissatisfaction was positively correlated to restrained eating (r=0.293, P<0.001), emotional eating (r=0.073, P=0.042) and binge eating (r=0.250, P<0.001). The interaction between body dissatisfaction and gender was significantly associated with more restrained eating (Beta=0.01, P<0.001) and orthorexia nervosa (Beta=-0.09, P<0.001), but not with emotional (Beta=-0.43, P=0.103) and binge eating (Beta=-0.08, P=0.358). When stratifying the analysis by gender, the results revealed that higher body dissatisfaction was significantly associated with more restrained eating in both genders, but particularly among women. Body dissatisfaction was significantly associated with higher emotional eating in men only and with higher orthorexia nervosa tendencies and behaviors in females only. CONCLUSION: The interaction between body dissatisfaction and gender was significantly associated with orthorexia nervosa and restrained eating but not with binge or emotional eating. Higher body dissatisfaction was significantly associated with higher restrained eating, more pronounced in women, while it was significantly associated with higher orthorexia tendencies (lower ORTO-15 scores) in women only. Body dissatisfaction was associated with emotional eating in men only.


Subject(s)
Body Dissatisfaction , Feeding and Eating Disorders , Adolescent , Adult , Anxiety , Cross-Sectional Studies , Feeding Behavior , Feeding and Eating Disorders/epidemiology , Female , Humans , Male , Research Design , Surveys and Questionnaires , Young Adult
5.
Encephale ; 47(4): 314-318, 2021 Aug.
Article in English | MEDLINE | ID: mdl-33541713

ABSTRACT

OBJECTIVE: To assess: (1) the association between insomnia experienced at admission, sociodemographic and other patients' characteristics and mania; and (2) the variation of insomnia and mania before and after treatment in bipolar patients with manic episodes (type I). METHODS: Sixty-two patients were interviewed shortly after their admission to the hospital (after 3 to 5 days). The current symptoms experienced by the patients were assessed upon admission and again at discharge from the hospital. RESULTS: A poorer quality of sleep (higher PSQI scores) (Beta=0.590) was significantly associated with higher mania, whereas the intake of SSRIs (Beta=-5.952) and TCAs (Beta=-8.181) was significantly associated with lower mania. Furthermore, highly significant reductions were reported in the PSQI scores (4.96 vs. 2.75, P<0.001), ISI scores (8.30 vs. 3.45, P<0.001) and YMRS scores (8.60 vs. 3.06, P<0.001) between admission to and discharge from the hospital. CONCLUSION: Insomnia in patients with bipolar disorder type I is associated with mania, with a significant reduction of sleep problems seen during a period of approximately 20 days of hospitalization. Further longitudinal studies are needed to confirm the validity of our results and identify the causes. In the meantime, this research recommends a strategy to improve sleeplessness experienced during inter-episode phases may be helpful in preventing manic episodes in BD.


Subject(s)
Bipolar Disorder , Sleep Initiation and Maintenance Disorders , Bipolar Disorder/complications , Bipolar Disorder/drug therapy , Bipolar Disorder/epidemiology , Hospitalization , Humans , Mania , Sleep Initiation and Maintenance Disorders/complications , Sleep Initiation and Maintenance Disorders/epidemiology
6.
Sci Rep ; 10(1): 1250, 2020 01 27.
Article in English | MEDLINE | ID: mdl-31988373

ABSTRACT

In predators an ontogenetic trophic shift includes change from small to large prey of several different taxa. In myrmecophagous predators that are also mimics of ants, the ontogenetic trophic shift should be accompanied by a parallel mimetic change. Our aim was to test whether ant-eating jumping spider, Mexcala elegans, is myrmecomorphic throughout their ontogenetic development, and whether there is an ontogenetic shift in realised trophic niche and their mimetic models. We performed field observations on the association of Mexcala with ant species and investigated the natural prey of the ontogenetic classes by means of molecular methods. Then we measured the mimetic similarity of ontogenetic morphs to putative mimetic models. We found Mexcala is an inaccurate mimic of ants both in the juvenile and adult stages. During ontogenesis it shifts mimetic models. The mimetic similarity was rather superficial, so an average bird predator should distinguish spiders from ants based on colouration. The realised trophic niche was narrow, composed mainly of ants of different species. There was no significant difference in the prey composition between ontogenetic stages. Females were more stenophagous than juveniles. We conclude that Mexcala is an ant-eating specialist that reduces its prey spectrum and shifts ant models during ontogenesis.


Subject(s)
Biological Mimicry/physiology , Predatory Behavior/physiology , Spiders/physiology , Adaptation, Biological/physiology , Animals , Ants , Biological Evolution , Biological Ontologies , Ecosystem , Female , Male , Selection, Genetic/genetics , Spiders/metabolism
9.
CEAS Aeronaut J ; 11(4): 991-1007, 2020.
Article in English | MEDLINE | ID: mdl-33403052

ABSTRACT

In this paper, the required models and methods to analyze and quantify the potential demand for urban air mobility (UAM) complementing public transport and possible impacts were defined and applied to the Munich Metropolitan region. An existing agent-based transport model of the study area were used and extended to cover socio-demographic changes up to the year 2030 and intermodal UAM services. An incremental logit model for UAM was derived to simulate demand for this new mode. An airport access model was developed as well. Three different UAM networks with different numbers of vertiports were defined. Sensitivity studies of ticket fare and structure, flying vehicle cruise speed, passenger process times at vertiports and different Urban Air Mobility networks sizes were performed. For the reference case, UAM accounts for a modal share of 0.5%. The absolute UAM demand is concentrated on very short routes; hence, UAM vehicle flight speed variation shows low UAM demand impacts. Kilometer-based fare, number of UAM vehicles per vertiport and passenger process times at vertiports show a significant impact on UAM demand.

10.
Br J Dermatol ; 182(3): 618-624, 2020 03.
Article in English | MEDLINE | ID: mdl-31396952

ABSTRACT

BACKGROUND: Because of its rarity, the exact incidence of and mortality from epidermal necrolysis (Stevens-Johnson syndrome/toxic epidermal necrolysis) is difficult to establish and closely depends on the size and type of the data source. OBJECTIVES: To estimate the incidence of and mortality due to epidermal necrolysis in France over a 14-year period. METHODS: Data from four national databases were analysed. A capture-recapture analysis was performed. RESULTS: A total of 2635 incident cases of epidermal necrolysis were recorded in at least one of the four databases during the study period [males: 47·9%; median age: 52 (interquartile range 25-72) years]. On capture-recapture analysis, the estimated total number of cases was 5686, for an overall estimated annual incidence of 6·5 (95% confidence interval 4·1-8·9) cases per million inhabitants. The estimated annual incidence rates were 4·1 (0·3-7·9) cases per million inhabitants < 20 years of age, 3·9 (1·5-6·3) cases per million inhabitants aged 20-64 years and 13·7 (5·4-22·0) cases per million inhabitants ≥ 65 years of age. The estimated overall annual mortality rate from epidermal necrolysis was 0·9 (0·1-1·8) case per million inhabitants. It was 0·6 (0·1-1·5) case per million inhabitants aged 20-64 years and 2·8 (0·9-6·6) cases per million inhabitants ≥ 65 years of age (deaths in people < 20 years old were too rare to provide an accurate estimate). CONCLUSIONS: The annual incidence of epidermal necrolysis is higher than the one to five cases per million inhabitants usually reported. Such estimations could be helpful in establishing appropriate healthcare plans for people with epidermal necrolysis, in particular the need for specialized care units. What's already known about this topic? Few data are available regarding incidence of and mortality from epidermal necrolysis in the general population. Experts in epidermal necrolysis have recently proposed an annual incidence of one to five cases per million individuals. The overall mortality rate is usually reported to be between 10% and 20%. What does this study add? Using a four-source capture-recapture method and data from a 14-year period (2003-16), the annual incidence of and mortality from epidermal necrolysis were estimated to be 6·5 (95% confidence interval 4·1-8·9) and 0·9 (0·1-1·8) cases per million French inhabitants, respectively. Such estimations could be helpful in establishing appropriate healthcare plans, in particular the need for specialized care units.


Subject(s)
Stevens-Johnson Syndrome , Adult , Aged , Child, Preschool , Databases, Factual , France/epidemiology , Humans , Incidence , Male , Middle Aged , Stevens-Johnson Syndrome/epidemiology , Young Adult
11.
Radiat Oncol ; 14(1): 93, 2019 Jun 03.
Article in English | MEDLINE | ID: mdl-31159840

ABSTRACT

BACKGROUND: Liver tumors are subject to motion with respiration, which is typically accounted for by increasing the target volume. The prescription dose is often reduced to keep the mean liver dose under a threshold level to limit the probability of radiation induced liver toxicity. A retrospective planning study was performed to determine the potential clinical gains of removal of respiratory motion from liver SABR treatment volumes, which may be achieved with gating or tumor tracking. METHODS: Twenty consecutive liver SABR patients were analysed. The treated PTV included the GTV in all phases of respiration (ITV) with a 5 mm margin. The goal prescription was 50Gy/5# (BED 100 Gy10) but was reduced by 2.5 Gy increments to meet liver dose constraints. Elimination of motion was modelled by contouring the GTV in the expiration phase only, with a 5 mm PTV margin. All patients were replanned using the no-motion PTV and tumor dose was escalated to higher prescription levels where feasible given organ-at-risk constraints. For the cohort of patients with metastatic disease, BED gains were correlated to increases in tumour control probability (TCP). The effect of the gradient of the TCP curve on the magnitude of TCP increase was evaluated by repeating the study for an additional prescription structure, 54Gy/3# (BED 151 Gy10). RESULTS: Correlation between PTV size and prescribed dose exists; PTVs encompassing < 10% of the liver could receive the highest prescription level. A monotonically increasing correlation (Spearman's rho 0.771, p = 0.002) between the degree of PTV size reduction and motion vector magnitude was observed for GTV sizes <100cm3. For 11/13 patients initially planned to a decreased prescription, tumor dose escalation was possible (5.4Gy10-21.4Gy10 BED) using the no-motion PTV. Dose escalation in excess of 20 Gy10 increased the associated TCP by 5% or more. A comparison of TCP gains between the two fractionation schedules showed that, for the same patient geometry, the absolute increase in BED was the overarching factor rather than the gradient of the TCP curve. CONCLUSIONS: In liver SABR treatments unable to be prescribed optimal dose due to exceeding mean liver thresholds, eliminating respiratory motion allowed dose escalation in the majority of patients studied and substantially increased TCP.


Subject(s)
Liver Neoplasms/radiotherapy , Radiosurgery/methods , Respiration , Four-Dimensional Computed Tomography , Humans , Liver Neoplasms/diagnostic imaging , Liver Neoplasms/pathology , Motion , Radiographic Image Interpretation, Computer-Assisted , Radiotherapy Dosage , Radiotherapy Planning, Computer-Assisted , Radiotherapy, Intensity-Modulated , Relative Biological Effectiveness , Retrospective Studies
12.
Transfus Clin Biol ; 26(4): 341-345, 2019 Nov.
Article in English | MEDLINE | ID: mdl-30905678

ABSTRACT

Voluntary non-remunerated donations remain the cornerstone for a safe and sustainable blood supply. According to the World Health Organization and other international scientific committees, all nations must switch their system of blood collection to voluntary non-remunerated donation. Several other types of blood donations still exist nowadays that will be discussed. Lebanon, similarly to other developing countries, is struggling to achieve 100% voluntary non-remunerated donations for the many existing social, demographic, cultural and economic problems. Replacement donations remain the predominant type, which creates huge burden on both hospital blood banks and patient families. Despite the limited resources, some improvements have been made recently in this field and Lebanon seems to be on the road of achieving 100% voluntary non-remunerated blood donation as requested by the World Health Organization. The Lebanese experience is worth sharing so that neighbouring countries facing similar problems could benefit from it.


Subject(s)
Blood Donors , Blood Transfusion , Altruism , Blood Banks/economics , Blood Banks/organization & administration , Blood Banks/statistics & numerical data , Blood Donors/psychology , Blood Donors/statistics & numerical data , Blood Donors/supply & distribution , Blood Transfusion/economics , Blood Transfusion/statistics & numerical data , Developing Countries , Directed Tissue Donation , France , Health Services Needs and Demand , Humans , International Cooperation , Lebanon , Models, Theoretical , Motivation , Private Sector , Remuneration , Volunteers
13.
Heredity (Edinb) ; 122(5): 545-557, 2019 05.
Article in English | MEDLINE | ID: mdl-30356224

ABSTRACT

Recent advances in the field of landscape genetics provide ways to jointly analyze the role of present-day climate and landscape configuration in current biodiversity patterns. Expanding this framework into a phylogeographic study, we incorporate information on historical climatic shifts, tied to descriptions of the local topography and river configuration, to explore the processes that underlie genetic diversity patterns in the Atlantic Forest hotspot. We study two montane, stream-associated species of glassfrogs: Vitreorana eurygnatha and V. uranoscopa. By integrating species distribution modeling with geographic information systems and molecular data, we find that regional patterns of molecular diversity are jointly explained by geographic distance, historical (last 120 ky) climatic stability, and (in one species) river configuration. Mitochondrial DNA genealogies recover significant regional structure in both species, matching previous classifications of the northern and southern forests in the Atlantic Forest, and are consistent with patterns reported in other taxa. Yet, these spatial patterns of genetic diversity are only partially supported by nuclear data. Contrary to data from lowland taxa, historical climate projections suggest that these montane species were able to persist in the southern Atlantic Forest during glacial periods, particularly during the Last Glacial Maximum. These results support generally differential responses to climatic cycling by northern (lowland) and southern (montane) Atlantic Forest species, triggered by the joint impact of regional landscape configuration and climate change.


Subject(s)
Anura/genetics , Ecosystem , Genetics, Population , Animals , Anura/classification , Climate Change , Evolution, Molecular , Forests , Genetic Variation , Genome/genetics , Models, Genetic , Phylogeny , Phylogeography , Rivers , Species Specificity
14.
Sci Rep ; 8(1): 9600, 2018 06 25.
Article in English | MEDLINE | ID: mdl-29941894

ABSTRACT

Hybridization of parasites can generate new genotypes with high virulence. The fungal amphibian parasite Batrachochytrium dendrobatidis (Bd) hybridizes in Brazil's Atlantic Forest, a biodiversity hotspot where amphibian declines have been linked to Bd, but the virulence of hybrid genotypes in native hosts has never been tested. We compared the virulence (measured as host mortality and infection burden) of hybrid Bd genotypes to the parental lineages, the putatively hypovirulent lineage Bd-Brazil and the hypervirulent Global Pandemic Lineage (Bd-GPL), in a panel of native Brazilian hosts. In Brachycephalus ephippium, the hybrid exceeded the virulence (host mortality) of both parents, suggesting that novelty arising from hybridization of Bd is a conservation concern. In Ischnocnema parva, host mortality in the hybrid treatment was intermediate between the parent treatments, suggesting that this species is more vulnerable to the aggressive phenotypes associated with Bd-GPL. Dendropsophus minutus showed low overall mortality, but infection burdens were higher in frogs treated with hybrid and Bd-GPL genotypes than with Bd-Brazil genotypes. Our experiment suggests that Bd hybrids have the potential to increase disease risk in native hosts. Continued surveillance is needed to track potential spread of hybrid genotypes and detect future genomic shifts in this dynamic disease system.


Subject(s)
Anura/microbiology , Chytridiomycota/pathogenicity , Host-Parasite Interactions , Animals , Anura/parasitology , Larva/microbiology , Larva/parasitology , Virulence
17.
Encephale ; 44(5): 397-402, 2018 Nov.
Article in English | MEDLINE | ID: mdl-29307705

ABSTRACT

OBJECTIVES: The Hamilton Depression Rating Scale (HDRS) is the most commonly used scale for the evaluation of patients' treatments for depression. Since the HDRS has never been validated in Lebanon to our knowledge, our primary objective, therefore, is to investigate the correlation, sensitivity, specificity, as well as the reliability and the validity of the Hamilton Depression Rating Scale (HDRS) among Lebanese depressed patients. The secondary objective is to identify sociodemographic factors that would be correlated to depression among our sample. METHODS: This case-control study, performed between January till May 2017, included 400 patients (200 patients, 200 controls). RESULTS: The HDRS scale items converged over a solution of four factors, explaining a total of 58.88% of the variance. A high Cronbach's alpha was found for the full scale (0.862). A stepwise linear regression, using the total HDRS score as continuous variable, showed that a low socioeconomic level, divorced participants and a family history of mental disorders would significantly increase the HDRS total score (Beta=4.278; Beta=5.405; and Beta=3.922) respectively. However, having a university level of education would significantly decrease the HDRS total score (Beta=-4.248, P<0.001). CONCLUSION: This study shows that the Arabic version of the HDRS has promising psychometric properties, making it a good tool to use for the diagnosis of patients with depression. Depression recognition and treatment in general practice with the aim of improving patient outcome and reducing health care expenditure, is definitely warranted.


Subject(s)
Depressive Disorder/diagnosis , Psychiatric Status Rating Scales , Psychometrics/methods , Adult , Aged , Case-Control Studies , Depression/diagnosis , Depression/ethnology , Depressive Disorder/ethnology , Female , Humans , Language , Lebanon/epidemiology , Male , Middle Aged , Psychometrics/standards , Reproducibility of Results , Risk Factors , Sensitivity and Specificity , Socioeconomic Factors
18.
Chromosoma ; 127(2): 269-278, 2018 06.
Article in English | MEDLINE | ID: mdl-29372309

ABSTRACT

Heteromorphic sex chromosomes are common in eukaryotes and largely ubiquitous in birds and mammals. The largest number of multiple sex chromosomes in vertebrates known today is found in the monotreme platypus (Ornithorhynchus anatinus, 2n = 52) which exhibits precisely 10 sex chromosomes. Interestingly, fish, amphibians, and reptiles have sex determination mechanisms that do or do not involve morphologically differentiated sex chromosomes. Relatively few amphibian species carry heteromorphic sex chromosomes, and when present, they are frequently represented by only one pair, either XX:XY or ZZ:ZW types. Here, in contrast, with several evidences, from classical and molecular cytogenetic analyses, we found 12 sex chromosomes in a Brazilian population of the smoky jungle frog, designated as Leptodactylus pentadactylus Laurenti, 1768 (Leptodactylinae), which has a karyotype with 2n = 22 chromosomes. Males exhibited an astonishing stable ring-shaped meiotic chain composed of six X and six Y chromosomes. The number of sex chromosomes is larger than the number of autosomes found, and these data represent the largest number of multiple sex chromosomes ever found among vertebrate species. Additionally, sequence and karyotype variation data suggest that this species may represent a complex of species, in which the chromosomal rearrangements may possibly have played an important role in the evolution process.


Subject(s)
Anura/genetics , Sex Determination Processes , X Chromosome/metabolism , Y Chromosome/metabolism , Animals , Anura/classification , Brazil , Comparative Genomic Hybridization , Female , In Situ Hybridization, Fluorescence , Karyotype , Karyotyping , Male , Phylogeny , X Chromosome/ultrastructure , Y Chromosome/ultrastructure
19.
AJNR Am J Neuroradiol ; 39(2): 369-374, 2018 Feb.
Article in English | MEDLINE | ID: mdl-29217740

ABSTRACT

BACKGROUND AND PURPOSE: Few articles in the literature have looked at the diameter of the optic nerve on MR imaging, especially in children, in whom observations are subjective and no normative data exist. The aim of this study was to establish a data base for optic nerve diameter measurements on MR imaging in the pediatric population. MATERIALS AND METHODS: This was a retrospective study on the MR imaging of pediatric subjects (younger than 18 years of age) at the Department of Diagnostic Radiology at the American University of Beirut Medical Center, Beirut, Lebanon. The optic nerve measurements were obtained by 3 raters on axial and coronal sections at 3 mm (retrobulbar) and 7 mm (intraorbital) posterior to the lamina cribrosa. RESULTS: Of 211 scans of patients (422 optic nerves), 377 optic nerves were measured and included. Ninety-four patients were female (45%) and the median age at MR imaging was 8.6 years (interquartile range, 3.9-13.3 years). Optic nerves were divided into 5 age groups: 0-6 months (n = 18), 6 months-2 years (n = 44), 2-6 years (n = 86), 6-12 years (n = 120), and 12-18 years (n = 109). An increase in optic nerve diameter was observed with age, especially in the first 2 years of life. Measurements did not differ with eye laterality or sex. CONCLUSIONS: We report normative values of optic nerve diameter measured on MR imaging in children from birth to 18 years of age. A rapid increase in optic nerve diameter was demonstrated during the first 2 years of life, followed by a slower increase. This was independent of sex or eye laterality.


Subject(s)
Optic Nerve/anatomy & histology , Optic Nerve/growth & development , Adolescent , Child , Child, Preschool , Female , Humans , Infant , Magnetic Resonance Imaging/methods , Male , Reference Values , Retrospective Studies
20.
Proc Biol Sci ; 284(1861)2017 Aug 30.
Article in English | MEDLINE | ID: mdl-28835551

ABSTRACT

Deforestation has detrimental consequences on biodiversity, affecting species interactions at multiple scales. The associations among vertebrates, pathogens and their commensal/symbiotic microbial communities (i.e. microbiomes) have important downstream effects for biodiversity conservation, yet we know little about how deforestation contributes to changes in host microbial diversity and pathogen abundance. Here, we tested the effects of landcover, forest connectivity and infection by the chytrid fungus Batrachochytrium dendrobatidis (Bd) on amphibian skin bacterial diversity along deforestation gradients in Brazilian landscapes. If disturbance to natural habitat alters skin microbiomes as it does in vertebrate host communities, then we would expect higher host bacterial diversity in natural forest habitats. Bd infection loads are also often higher in these closed-canopy forests, which may in turn impact skin-associated bacterial communities. We found that forest corridors shaped composition of host skin microbiomes; high forest connectivity predicted greater similarity of skin bacterial communities among host populations. In addition, we found that host skin bacterial diversity and Bd loads increased towards natural vegetation. Because symbiotic bacteria can potentially buffer hosts from Bd infection, we also evaluated the bi-directional microbiome-Bd link but failed to find a significant effect of skin bacterial diversity reducing Bd infections. Although weak, we found support for Bd increasing bacterial diversity and/or for core bacteria dominance reducing Bd loads. Our research incorporates a critical element in the study of host microbiomes by linking environmental heterogeneity of landscapes to the host-pathogen-microbiome triangle.


Subject(s)
Amphibians/microbiology , Forests , Microbiota , Skin/microbiology , Animals , Bacteria/classification , Biodiversity , Brazil , Chytridiomycota/pathogenicity , Host-Pathogen Interactions
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