Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 12 de 12
Filter
Add more filters










Publication year range
1.
Ecol Appl ; 28(7): 1867-1883, 2018 10.
Article in English | MEDLINE | ID: mdl-30055061

ABSTRACT

Habitat loss and degradation induced by human development are among the major threats to biodiversity worldwide. In this study, we tested our ability to predict the response of bird communities (128 species) to land-use changes in southern Quebec (~483,100 km2 ) over the last 30 yr (between 1984-1989 and 2010-2014) by using species distribution models (299,302 occurrences in 30,408 locations) from a hindcasting perspective. Results were grouped by functional guilds to infer potential impacts on ecosystem services, and to relate model transferability (i.e., ability of our models to be generalized to other times and scales) to specific functional and life-history traits. Overall, our models were able to accurately predict, both in space and time, habitat suitability for 69% of species, especially for granivorous, nonmigrant, tree-nesting species, and species that are tied to agricultural areas under intensive use. These findings indicate that model transferability depends upon specific functional and life-history traits, providing further evidence that species' ecologies affect the ability of models to accurately predict bird distributions. Declining bird species were mostly short-distance migrants that were associated with open habitats (agricultural and nonproductive forest) with aerial insectivorous or granivorous diets, which may be related to agricultural intensification and land abandonment. Land-use changes were positive for some forest bird species that were mainly associated with mixed and deciduous forests, generalist diets and tree-nesting strategies. Yet cavity-nesting birds have suffered substantial reductions in their distributions, suggesting that cumulative effects of intensive logging and wildfires on mature forests pose a threat for forest-specialist species. Habitat suitability changes predicted by our coarse-scale species distribution models partially agreed with the long-term trends reported by the North American Breeding Bird Survey. Our findings confirm land-use change as a key driving force for shaping bird communities in southern Quebec, together with the need to explicitly incorporate it into global change scenarios that better inform decision-makers on conservation and management.


Subject(s)
Agriculture , Animal Distribution , Birds , Forests , Animals , Ecosystem , Models, Biological , Quebec
2.
Eur J Pediatr Surg ; 28(3): 238-242, 2018 Jun.
Article in English | MEDLINE | ID: mdl-28505691

ABSTRACT

INTRODUCTION: Laparoscopic pyloromyotomy (LPM) is a minimally invasive surgical technique used in pyloric stenosis treatment. This technique is safe, effective, and does not show more complications than laparotomy. Nevertheless, this technique requires an acquisition period to be optimally applied. This study analyses the learning curve of LPM. MATERIALS AND METHODS: Seven surgeons were retrospectively evaluated on their 40 first LPM. Patient data were recorded, including peroperative data (operation length and complications) and postoperative recoveries (renutrition, vomiting, and complications). The learning curves were evaluated and each variable was compared with the different moments of the learning curve. RESULTS: The mean operative time is 25 ± 11 minutes. It significantly decreases with the learning curve (p < 0.01). Ten procedures were necessary to acquire the operative technics. However, postoperative complications with a necessary redo procedure appear after the 10th patient. There is no significant difference concerning long-term postoperative complications according to the learning curve and to surgeons. The best results are recorded after the 20th patients. Hospital length of stay also decreases significantly after the 10th procedure. The recorded postoperative vomiting is independent to the operative time as the ad libitum feedings recovery. CONCLUSION: The learning curve of LPM is cut into three stages. Only 10 cases are needed to acquire the gesture. Complications appear after this acquirement period.


Subject(s)
Laparoscopy/education , Learning Curve , Pyloric Stenosis, Hypertrophic/surgery , Pyloromyotomy/education , Female , France , Humans , Infant , Infant, Newborn , Male , Operative Time , Postoperative Complications/epidemiology , Postoperative Complications/etiology , Pyloromyotomy/methods , Retrospective Studies , Treatment Outcome
3.
PLoS One ; 12(5): e0176299, 2017.
Article in English | MEDLINE | ID: mdl-28472048

ABSTRACT

Following heavy precipitation, we observed an intense algal bloom in the St. Lawrence Estuary (SLE) that coincided with an unusually high mortality of several species of marine fish, birds and mammals, including species designated at risk. The algal species was identified as Alexandrium tamarense and was determined to contain a potent mixture of paralytic shellfish toxins (PST). Significant levels of PST were found in the liver and/or gastrointestinal contents of several carcasses tested as well as in live planktivorous fish, molluscs and plankton samples collected during the bloom. This provided strong evidence for the trophic transfer of PST resulting in mortalities of multiple wildlife species. This conclusion was strengthened by the sequence of mortalities, which followed the drift of the bloom along the coast of the St. Lawrence Estuary. No other cause of mortality was identified in the majority of animals examined at necropsy. Reports of marine fauna presenting signs of neurological dysfunction were also supportive of exposure to these neurotoxins. The event reported here represents the first well-documented case of multispecies mass mortality of marine fish, birds and mammals linked to a PST-producing algal bloom.


Subject(s)
Dinoflagellida/growth & development , Eutrophication , Animals , Seawater
4.
Acta Chir Belg ; 116(2): 89-95, 2016 Apr.
Article in English | MEDLINE | ID: mdl-27385295

ABSTRACT

BACKGROUND: Pyloric atresia (PA) is a rare condition, and may be misdiagnosed and especially confused for duodenal atresia pre-operatively. We looked for clues to avoiding pre-operative misdiagnosis and hence allow the best neonatal medical and surgical management. METHODS: A retrospective case-note review was carried out of the five patients managed in four centres with the diagnosis of isolated PA. We focused on antenatal ultrasound findings, postnatal clinical and radiological features, operative findings, surgical procedures and outcomes. RESULTS: Four patients had polyhydramnios and one double bubble sign on antenatal ultrasound. After birth, non-bilious vomiting and upper abdominal distension were the main symptoms. Gastric decompression showed non-bilious gastric fluid. Radiological findings were a large gastric air bubble with no gas beyond in all cases. The diagnosis of duodenal atresia was postulated at first in all cases. The diagnosis of PA was established peroperatively. One patient referred late, died 13-day post-operatively of cardiopulmonary failure secondary to a severe pneumonia that may be related to aspiration syndrome. Outcomes were otherwise satisfactory. CONCLUSIONS: Even though it is a rare diagnosis, PA has a specific clinical and radiological presentation underlined here that should be kept in mind when managing a neonate with a gastric outlet obstruction.


Subject(s)
Duodenal Obstruction/surgery , Gastric Outlet Obstruction/etiology , Gastric Outlet Obstruction/surgery , Pylorus/abnormalities , Anastomosis, Surgical , Diagnosis, Differential , Duodenal Obstruction/diagnosis , Female , Follow-Up Studies , Gastric Outlet Obstruction/complications , Gastric Outlet Obstruction/diagnosis , Humans , Infant, Newborn , Intestinal Atresia , Laparotomy/methods , Male , Prenatal Diagnosis , Pylorus/surgery , Retrospective Studies , Risk Assessment , Sampling Studies , Severity of Illness Index , Treatment Outcome , Ultrasonography, Prenatal/methods
5.
Eur J Med Genet ; 56(12): 643-7, 2013 Dec.
Article in English | MEDLINE | ID: mdl-24161495

ABSTRACT

This report concerns a 3-year-old girl with prenatal bilateral nephroblastomatosis and a family history of nephroblastoma. This girl had a chromosome 8 pericentric inversion inherited from her father. This inversion was observed in healthy individuals of the family and was absent in other individuals suffering from embryonic kidney tumor. We then supposed that another genetic anomaly predisposed her to tumorogenesis. Additional cryptic imbalances are reported in cases of apparently balanced chromosomal rearrangements with an abnormal phenotype. Array-CGH analysis showed a 569 kb duplication at 2p24.3 including the DDX1 and MYCN genes. This duplication was inherited from the patient's father who also had a nephroblastoma. A link between germline MYCN duplication and the occurrence of other embryonic cancers such as neuroblastoma has already been described. We supposed that germline DDX1-MYCN duplication could also be involved in the apparition of nephroblastomas.


Subject(s)
DEAD-box RNA Helicases/genetics , Gene Duplication , Germ-Line Mutation , Kidney Neoplasms/genetics , Nuclear Proteins/genetics , Oncogene Proteins/genetics , Wilms Tumor/genetics , Adult , Carcinogenesis/genetics , Child, Preschool , Chromosomes, Human, Pair 8/genetics , Comparative Genomic Hybridization , Female , Genetic Predisposition to Disease , Humans , Kidney Neoplasms/diagnosis , Male , N-Myc Proto-Oncogene Protein , Pedigree , Wilms Tumor/diagnosis
6.
Arch Environ Contam Toxicol ; 63(3): 429-36, 2012 Oct.
Article in English | MEDLINE | ID: mdl-22875100

ABSTRACT

The eastern North American population of Barrow's goldeneyes winters in the St. Lawrence Estuary and Gulf of St. Lawrence where the sediments and food web are known to be contaminated with inorganic and organic compounds. Therefore, there is a potential for contamination of this population, which is designated of Special Concern by the Committee on the Status of Endangered Wildlife in Canada. Specimens were collected during three consecutive winters (2005-2007) in three regions (Manicouagan, Charlevoix, and Chaleur Bay) and analysed for metals, trace elements, polychlorinated biphenyls (PCBs), organochlorine pesticides, and brominated flame retardants (BFRs). Liver mercury levels were greater in the St. Lawrence Estuary (4.4 mg/kg in Manicouagan, 3.8 mg/kg in Charlevoix) than in Chaleur (2.4 mg/kg), whereas selenium showed the opposite pattern (7.3 mg/kg in Manicouagan, 7.0 mg/kg in Charlevoix, and 36.9 mg/kg in Chaleur). Liver PCB levels were greater in specimens from Manicouagan (236 ng/g) than in those from the two other regions (72 ng/g in Charlevoix, 35 ng/g in Chaleur). DDT was greater in Chaleur (66 ng/g) versus 10 ng/g in Manicouagan and 16 ng/g in Charlevoix. BFRs were not compared among regions because of smaller sample sizes, but mean total concentration was low (4.02 ng/g). Overall, although significant differences were found across regions, levels of all contaminants measured are generally low and not of toxicological concern for this population.


Subject(s)
Anseriformes/metabolism , Environmental Monitoring , Environmental Pollutants/metabolism , Environmental Pollution/statistics & numerical data , Animal Migration , Animals , Female , Flame Retardants/metabolism , Hydrocarbons, Brominated/metabolism , Hydrocarbons, Chlorinated/metabolism , Male , Metals/metabolism , Pesticides/metabolism , Polychlorinated Biphenyls/metabolism , Quebec , Seasons , Trace Elements/metabolism
8.
Prog Urol ; 15(2): 291-5; discussion 295, 2005 Apr.
Article in French | MEDLINE | ID: mdl-15999610

ABSTRACT

INTRODUCTION: Macroplastique has been used since 1993 for the endoscopic treatment of vesico-ureteric reflux in children with a failure rate per injected ureteric unit of 21%. The objective of this study was to analyse these failures on the basis of endoscopic findings on injection, ultrasound data at 2 months post-endoscopy and operative findings during the secondary reimplantation. MATERIAL AND METHODS: The authors retrospectively reviewed cases of failure of Macroplastique treatment from September 1993 to December 2002. Only children undergoing subsequent surgical reimplantation were included in the study: 60 cases (57 girls, 3 boys). Another 68 patients also presented recurrence of reflux, but are currently asymptomatic and have not been reoperated. Twenty five patients (42%) initially presented unilateral vesico-ureteric reflux: bilateral injection was performed in 17 of these cases because of the anatomical findings on endoscopy. In 92% of cases, the refluxing ureteric orifice appeared to be abnormal (in terms of position, appearance and the submucosal course of the ureter). RESULTS: Eleven children (18%) presented symptomatic or asymptomatic urinary tract infection before the first clinical and radiological review at 2 months. On the first ultrasound examination, the implant was visualized in the bladder wall in 71% of cases. At reimplantation, the bladder mucosa was inflammatory in 56 patients (94%). The ureteric orifice remained gaping in 38% of cases and the implant appeared to be modified (migration, decreased volume) in 35% of cases. CONCLUSION: Failures of endoscopic treatment by Macroplastique can be due to persistence of pre-existing ureteric anatomical lesions (poor indication, technical error or difficulty) or modification of the injected product. Bladder inflammation and therefore previous or post-endoscopy urinary tract infections may also play a role.


Subject(s)
Cystoscopy , Vesico-Ureteral Reflux/therapy , Adolescent , Biocompatible Materials/administration & dosage , Child , Child, Preschool , Female , Humans , Male , Retrospective Studies , Treatment Failure
9.
Prog Urol ; 13(6): 1368-71, 2003 Dec.
Article in French | MEDLINE | ID: mdl-15000316

ABSTRACT

OBJECTIVE: Since 1993, the authors have used a Macroplastique (polydimethylsiloxane) implant for the endoscopic treatment of vesicoureteric reflux (VUR) in children instead of Teflon (polytetrafluoroethylene). They report their results after 9 years of use of Macroplastique and analyse their failures. MATERIAL AND METHODS: 477 children with 669 refluxing ureters, classified as grade I reflux in 96 cases (14%), grade II reflux in 435 cases (65%), grade III reflux in 125 cases (19%), and grade IV reflux in 13 cases (2%), were treated at Tours University Hospital by the same surgeon, by injection of 0.1 to 0.5 ml (mean: 0.3 ml) of Macroplastique. 189 cases of unilateral reflux (66%) required a bilateral procedure on the basis of the endoscopic findings. The efficacy of treatment was evaluated on the absence of clinical and bacteriological signs of urinary tract infection and the absence of reflux on cystography during the study period. RESULTS: 354 of the 477 children (74%) and 514 of the 669 refluxing ureters (77%), including 167 cases of bilateral VUR (65%) and 180 cases of unilateral VUR (35%) were cured. A significant difference was observed between the cure rate for bilateral reflux and unilateral reflux (p<0.05). The failure rate in cases of grade I and II reflux was significantly higher than in grade III and IV (p<0.05). The development of de novo contralateral reflux was not statistically related to unilateral or bilateral injection for the treatment of unilateral reflux. CONCLUSION: The authors believe that the failure rate for grade I and II reflux could be explained by the concomitant presence of detrusor-sphincter dyssynergia that was not systematically investigated preoperatively and by the fact that endoscopic correction of anatomical lesions gives better results in the case of probably more malformative grade III and IV reflux.


Subject(s)
Dimethylpolysiloxanes , Vesico-Ureteral Reflux/therapy , Adolescent , Child , Child, Preschool , Cystoscopy , Female , Follow-Up Studies , Humans , Infant , Male , Retrospective Studies , Time Factors
10.
Int J Dermatol ; 41(10): 640-2, 2002 Oct.
Article in English | MEDLINE | ID: mdl-12390184

ABSTRACT

BACKGROUND: Oxidative stress could be an important phenomenon leading to melanocyte death in vitiligo. The accumulation of hydrogen peroxide (H2O2) and low catalase levels have recently been demonstrated in the epidermis of vitiligo patients. Few abnormalities of antioxidants have been found in the blood of patients with vitiligo, except for an elevation of selenium. No studies on oxidative stress have been performed so far on patients with skin phototype VI (Fitzpatrick classification). AIM: To study the blood antioxidant status of black patients with active generalized vitiligo. METHODS: Randox total antioxidant status, selenium, ferritin, transferrin, ceruloplasmin, tocopherol, and retinol levels were evaluated in blood samples obtained from 11 dark-skinned patients from the French West Indies (Isle of Martinique) with recent active lesions of vitiligo and from 11 age- and sex-matched healthy volunteers. RESULTS: Total blood antioxidant status and selenium levels were significantly increased in vitiligo patients, compared to those in sex- and age-matched controls (P < 0.01 and P < 0.02, respectively). Blood levels of ferritin, transferrin, ceruloplasmin, retinol, and tocopherol were not significantly modified. CONCLUSIONS: This is the first report on the global blood antioxidant status in vitiligo. The increase in total blood antioxidant status observed in black patients was an unexpected result that needs to be confirmed and explained by further studies. The spontaneous increase in selenium levels could be of interest, as it has been recommended in the treatment of vitiligo.


Subject(s)
Antioxidants/analysis , Black People/genetics , Selenium/blood , Vitiligo/blood , Vitiligo/genetics , Adult , Aged , Female , Humans , Male , Middle Aged , Risk Factors , Skin Pigmentation/genetics , Vitiligo/etiology
11.
Radiat Res ; 158(3): 339-45, 2002 Sep.
Article in English | MEDLINE | ID: mdl-12175311

ABSTRACT

We present direct experimental evidence of the fluence-rate-dependent, radiation-induced variations in intratumor oxygen partial pressure (pO(2)) in HT29 human colon adenocarcinoma xenografts subjected to meta-tetra(hydroxyphenyl)chlorin (mTHPC)-based photodynamic therapy (PDT). The data establish a correlation between tumor oxygenation and treatment outcome. Tumor-bearing mice were injected with 0.3 mg/kg photosensitizer and subjected 72 h later to a 12 J/cm(2) red light dose administered at fluence rates of 5, 30, 90 and 160 mW/cm(2). A significant decrease in mean and median pO(2) was registered at approximately half of the total radiation fluence was delivered in tumors treated at rates of 160 and 90 mW/cm(2). Conversely, with the two lower fluence rates, intratumor pO(2) was maintained at levels comparable to those measured before illumination. Tumor oxygenation values registered shortly after every treatment protocol were at least equal to baseline levels, thus excluding the possibility of significant acute vessel damage during illumination. The tumor regrowth profile correlated with the pO(2) values monitored during irradiation. Tumors treated with fluence rates of 5 and 30 mW/cm(2) exhibited significantly longer tumor quadrupling times than those treated at 160 and 90 mW/cm(2). Improved tumor destruction could be expected by reducing the rate and the extent of oxygen depletion during meta-tetra(hydroxyphenyl)chlorin photodynamic therapy using low fluence rates.


Subject(s)
Adenocarcinoma/therapy , Mesoporphyrins/therapeutic use , Oxygen/metabolism , Photochemotherapy , Photosensitizing Agents/therapeutic use , Skin Neoplasms/therapy , Adenocarcinoma/metabolism , Adenocarcinoma/pathology , Animals , Cell Hypoxia , Colonic Neoplasms/pathology , Dose-Response Relationship, Radiation , HT29 Cells , Humans , Lasers , Mesoporphyrins/pharmacology , Mice , Mice, Nude , Neoplasm Transplantation , Photosensitizing Agents/pharmacology , Skin Neoplasms/metabolism , Transplantation, Heterologous , Xenograft Model Antitumor Assays
12.
Anticancer Res ; 22(5): 2869-75, 2002.
Article in English | MEDLINE | ID: mdl-12536972

ABSTRACT

Epidermoid carcinomas, clinically and histologically similar to human squamous cell carcinomas (SCC), were obtained in hairless Skh-1 mice. Tumor cells originated from chemically-induced skin cancers. We developed three models of orthotopic skin tumors: (1) intradermal injection of a tumor cell suspension, (2) superficial abrasion of the skin, cell grafting and application of a hydrocolloid dressing, (3) skin incision, seeding and application of a hydrocolloid dressing. Intradermal injection was 100% successful. Skin incision, displaying histological evidence of rapid invasive tumor growth, was 75% successful. Though skin tumor growth after abrasion was only 20% successful, the tumor histogenesis exactly imitated human SCC development. These carcinomas provide research models for further experiments such as photodynamic therapy or antiangiogenesis therapy.


Subject(s)
Carcinoma, Squamous Cell/pathology , Disease Models, Animal , Neoplasm Transplantation/methods , Skin Neoplasms/pathology , Animals , Carcinoma, Squamous Cell/chemically induced , Female , Injections, Intradermal , Mice , Mice, Hairless , Reproducibility of Results , Skin Neoplasms/chemically induced
SELECTION OF CITATIONS
SEARCH DETAIL
...