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1.
Med Mal Infect ; 50(5): 397-400, 2020 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-32387320

RESUMEN

INTRODUCTION: No therapy has yet proven effective in COVID-19. Tocilizumab (TCZ) in patients with severe COVID-19 could be an effective treatment. METHOD: We conducted a retrospective case-control study in the Nord Franche-Comté Hospital, France. We compared the outcome of patients treated with TCZ and patients without TCZ considering a combined primary endpoint: death and/or ICU admissions. RESULTS: Patients with TCZ (n=20) had a higher Charlson comorbidity index (5.3 [±2.4] vs 3.4 [±2.6], P=0.014), presented with more severe forms (higher level of oxygen therapy at 13L/min vs 6L/min, P<0.001), and had poorer biological findings (severe lymphopenia: 676/mm3 vs 914/mm3, P=0.037 and higher CRP level: 158mg/L vs 105mg/L, P=0.017) than patients without TCZ (n=25). However, death and/or ICU admissions were higher in patients without TCZ than in the TCZ group (72% vs 25%, P=0.002). CONCLUSION: Despite the small sample size and retrospective nature of the work, this result strongly suggests that TCZ may reduce the number of ICU admissions and/or mortality in patients with severe SARS-CoV-2 pneumonia.


Asunto(s)
Anticuerpos Monoclonales Humanizados/uso terapéutico , Infecciones por Coronavirus/tratamiento farmacológico , Infecciones por Coronavirus/epidemiología , Infecciones por Coronavirus/mortalidad , Unidades de Cuidados Intensivos/estadística & datos numéricos , Admisión del Paciente/estadística & datos numéricos , Neumonía Viral/tratamiento farmacológico , Neumonía Viral/epidemiología , Neumonía Viral/mortalidad , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Betacoronavirus/efectos de los fármacos , Betacoronavirus/inmunología , COVID-19 , Estudios de Casos y Controles , Comorbilidad , Infecciones por Coronavirus/patología , Enfermedad Crítica/epidemiología , Enfermedad Crítica/mortalidad , Femenino , Francia/epidemiología , Humanos , Masculino , Persona de Mediana Edad , Mortalidad , Pandemias , Neumonía Viral/patología , Estudios Retrospectivos , SARS-CoV-2 , Índice de Severidad de la Enfermedad , Resultado del Tratamiento , Adulto Joven
3.
Animal ; 13(11): 2492-2500, 2019 11.
Artículo en Inglés | MEDLINE | ID: mdl-31084644

RESUMEN

Grazing management has an important impact on dairy ruminants' performance. References on the intake and milk yield of dairy goats under strip-grazing systems in temperate regions are scarce. In order to study the effect of pasture allowance on pasture intake (PI), milk yield and grazing behaviour, a trial was carried out in spring with 36 Alpine goats in mid-lactation. Three daily pasture allowances (PA=1.7, 2.6 and 3.5 kg dry matter (DM)/day, namely Low, Medium and High, respectively) were compared in a 3 × 3 Latin square design replicated six times during three successive 14-day periods. Goats individually received 268 g DM of concentrate twice daily at each milking and had access 11 h/day to pasture (from 0830 to 1600 h and from 1730 to 2100 h). Pasture intake increased with PA, and more so between Low and Medium than between Medium and High (+216 v. +101 g DM/kg DM of PA). Milk yield was lower on Low than on Medium and High (2.79 v. 3.13 kg/day), as were milk fat and protein yields. Grazing time averaged 476 min/day and was lowest on Low and greatest on Medium. Pasture intake rate was 30 g DM/h lower on Low and Medium than on High. It is concluded that under temperate conditions, when goats are supplemented with 536 g DM of concentrate and have enough access time to pasture (11 h/day), a medium pasture allowance close to 2.6 kg DM/day may be sufficient to maximise milk yield.


Asunto(s)
Suplementos Dietéticos/análisis , Conducta Alimentaria , Cabras/fisiología , Leche/metabolismo , Animales , Dieta/veterinaria , Femenino , Lactancia , Estaciones del Año
4.
Eur Ann Otorhinolaryngol Head Neck Dis ; 136(3S): S45-S47, 2019 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-30880035

RESUMEN

INTRODUCTION: Ear involvement by non-Hodgkin lymphoma is quite rare and can be mistaken for other common lesions encountered in otolaryngology. The literature on this subject is also limited. CASE SUMMARY: A 45-year-old man with bilateral ear nodules that progressed over two years. Biopsy of the right ear revealed a B-cell small lymphocytic lymphoma (SLL). The patient responded to radiotherapy well. He received an additional dose two months after the initial treatment because of a remaining nodularity on the right earlobe. After several months, he presented a new lesion on his nasal tip, for which a biopsy confirmed a lymphoma relapse. The patient was managed with oral prednisone and low-dose radiation with a favourable response. DISCUSSION: This case highlights the importance of including lymphoma in the differential diagnosis of ear lesions from an otolaryngology perspective. A biopsy of any lesion or nodule with an atypical course should be considered for appropriate diagnosis and management.


Asunto(s)
Pabellón Auricular , Neoplasias del Oído , Leucemia Linfocítica Crónica de Células B , Neoplasias Primarias Múltiples , Neoplasias del Oído/tratamiento farmacológico , Neoplasias del Oído/patología , Neoplasias del Oído/radioterapia , Humanos , Leucemia Linfocítica Crónica de Células B/tratamiento farmacológico , Leucemia Linfocítica Crónica de Células B/patología , Leucemia Linfocítica Crónica de Células B/radioterapia , Masculino , Persona de Mediana Edad , Neoplasias Primarias Múltiples/tratamiento farmacológico , Neoplasias Primarias Múltiples/patología , Neoplasias Primarias Múltiples/radioterapia , Neoplasias Nasales/secundario , Dosis de Radiación
6.
Rev Med Interne ; 36(12): 848-53, 2015 Dec.
Artículo en Francés | MEDLINE | ID: mdl-25795467

RESUMEN

INTRODUCTION: Myelolipomas and extramedullary hematopoietic tumors are uncommon benign tumors. They are variably composed of mature adipose tissue and hematopoietic tissue. Myelolipoma is usually observed in the adrenal gland and extramedullary hematopoietic tumors in the liver and spleen but may occasionally be found within solid tumors. CASE REPORT: A 62-year-old man without previous haematological history presented with a voluminous solitary bilateral renal tumor. Contrast-enhanced ultrasound CT-scan and scintigraphy with technetium-99m-nanocolloid and indium-111-chloride bone marrow were highly suggestive of extramedullary hematopoietic tumor. CT-guided biopsy suggested a diagnosis of myelolipoma. An atypical hereditary spherocytosis, undiagnosed until now, was demonstrated. CONCLUSION: We report, for the first time to our knowledge, a border form between extramedullary hematopoiesis tumor and myelolipoma of renal localisation revealing a hereditary spherocytosis in an adult patient.


Asunto(s)
Hematopoyesis Extramedular , Neoplasias Renales/complicaciones , Mielolipoma/complicaciones , Esferocitosis Hereditaria/complicaciones , Humanos , Riñón/fisiología , Masculino , Persona de Mediana Edad , Esferocitosis Hereditaria/diagnóstico
7.
Clin Microbiol Infect ; 17(1): 95-7, 2011 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-20167009

RESUMEN

We describe a fatal case of Reye's syndrome in a 12-year-old male patient during an influenza A (H3N2) infection for which he received salicylates. In the current situation of the novel A/H1N1 virus pandemic, we believe that it is of high importance to emphasize the risks associated with salicylate intake to avoid the reappearance of Reye's syndrome.


Asunto(s)
Subtipo H3N2 del Virus de la Influenza A , Gripe Humana/complicaciones , Síndrome de Reye/inducido químicamente , Síndrome de Reye/complicaciones , Ácido Salicílico/efectos adversos , Niño , Resultado Fatal , Humanos , Hígado/patología , Masculino , Síndrome de Reye/patología
9.
Encephale ; 35(1): 80-9, 2009 Feb.
Artículo en Francés | MEDLINE | ID: mdl-19250998

RESUMEN

INTRODUCTION: Adherence to (or compliance with) a medication is one of the foremost issues in the assumption of patients with psychiatric illness and, in particular, in schizophrenia. Adherence to medication is generally defined as the extent to which patients take medications as prescribed by their health care providers. There is no consensus to define an acceptable compliance. LITERATURE FINDINGS: The methods available for measuring adherence can be broken down into direct and indirect methods of measurement, each one having advantages and disadvantages. Clinical summations of studies were realized, the problem of poor adherence to medication concerned 25% of patients with schizophrenia and 74% of the 1493 schizophrenia patients recruited for the Catie study discontinued their assigned study medication before 18 months, a rate that was considered to be very high in a study in which the primary outcome measure was discontinuation of the study drug for any cause and approximately 30% stopped the treatment of their own motivation. In two thirds of cases, rehospitalisation is the result of complete or partial non-compliance. One year after first hospitalsation, 40% of relapse results from non-adherence to medication. DISCUSSION: Medication adherence problems increase hospitalisation, morbidity and mortality. Social consequences, professional and family problems linked to hospitalisations lead to low quality of life for patients and high cost for society. Indicators of poor adherence to a medication regimen are a useful resource for physicians to help identify patients who are most in need of interventions to improve adherence. It is usual to identify quatre categories of factors causing disparity: 1: factors due to psychiatric disorders; 2: factors due to medication; 3: factors linked to patients; 4: factors depending on the therapeutic relationship with the clinician. Patients with psychiatric illness typically have great difficulty following a medication regimen, but they also have the greatest potential for benefiting from adherence. Some effective actions to improve compliance are described in reply to the factors influencing the adherence. The communication attitude of the clinician, therapeutic relationship and prescription use are main points of alliance. Information and communication with the patient, simplification of the therapeutic plan, consultation planning and account of side effect are simple and effective actions. Social support is very important for improvement of therapeutic alliance. Poor therapeutic alliance is common, contributing to substantial worsening of disease and more research on compliance and therapeutic alliance evaluation is needed. Information and tools must be proposed to practitioners.


Asunto(s)
Antipsicóticos/uso terapéutico , Cumplimiento de la Medicación/psicología , Esquizofrenia/tratamiento farmacológico , Psicología del Esquizofrénico , Antipsicóticos/efectos adversos , Enfermedad Crónica , Estudios Transversales , Francia , Humanos , Cuidados a Largo Plazo , Cumplimiento de la Medicación/estadística & datos numéricos , Readmisión del Paciente , Recurrencia , Esquizofrenia/epidemiología
10.
Ann Fr Anesth Reanim ; 28(1): 74-7, 2009 Jan.
Artículo en Francés | MEDLINE | ID: mdl-19111431

RESUMEN

Pertussis is a leading cause of death from community infections in infant. Life-threatening clinical presentations of pertussis can associate multiple organ system failure with respiratory distress. The question of the optimal management of these severe forms of pertussis, in order to reduce the high mortality rate, is raised by the clinicians caring for such patients. We report the case of a 1 month infant who was admitted to the pediatric intensive care unit (PICU) for a severe pertussis. He presented with an acute respiratory distress syndrome, a severe pulmonary hypertension was treated initially with mechanical ventilation and nitric oxide. At day 4 (D4), a cardiogenic shock occurred and, despite epinephrine and norepinephrine infusion, fluid expansion, the hemodynamic condition worsened with two episodes of cardiac arrest. The child was then successfully resuscitated, and, facing the extreme hemodynamic instability, extracorporeal membrane oxygenation (ECMO) was considered. ECMO allowed epinephrine and norepinephrine to be progressively discontinued, and protective mechanical ventilation. ECMO withdrawal was possible at D9, with milrinone as the sole inotropic agent. Weaning from mechanical ventilation was possible on D15 and the total length of stay in PICU was 20days. While the analysis of the literature, through limited experiences on the use of ECMO in children with severe pertussis does not allow concluding definitively on the utility of ECMO in this situation, the contribution of ECMO in the favourable outcome for our patient was considerable. This is an argument, to our opinion, for considering ECMO in the management of those very instable patients.


Asunto(s)
Oxigenación por Membrana Extracorpórea , Tos Ferina/terapia , Cardiotónicos/uso terapéutico , Cuidados Críticos , Humanos , Hipertensión Pulmonar/etiología , Lactante , Masculino , Milrinona/uso terapéutico , Respiración Artificial , Síndrome de Dificultad Respiratoria/etiología , Resucitación , Choque Cardiogénico/etiología , Choque Cardiogénico/terapia , Vasoconstrictores/uso terapéutico
11.
Ann Fr Anesth Reanim ; 26(6): 585-92, 2007 Jun.
Artículo en Francés | MEDLINE | ID: mdl-17524602

RESUMEN

Steroids are indicated in paediatric intensive care as anti-inflammatory drugs or for substitutive treatment. During septic shock, the incidence of adrenal insufficiency (AI) varies between 18 à 52%, depending on the relative or absolute nature of the AI. Contrary to adults, for whom long courses of low doses of corticosteroids were shown to reduce mortality and increased shock reversibility, particularly in those with a negative synacthene test, no study provided sufficient evidence to show a benefit of steroids in terms of outcome in children with septic shock. In neonates, AI occurs frequently after cardiac surgery and the administration of steroids can improve haemodynamic condition. The recommended dose of hydrocortisone during septic shock or after cardiac surgery is 30 to 100 mg/m(2)/d. Dexamethasone is efficient to reduce postextubation stridor in children and neonate and the rate of reintubations in neonate. During croup, oral or parenteral steroids reduce clinical symptoms. Dexamethasone also reduces the incidence of severe chronic lung disease and the duration of tracheal intubation in premature infants. However the high incidence of side effects, particularly on the central nervous system, makes steroids currently not recommended for bronchopulmonary dysplasia. At last, steroids are indicated for severe asthma and for bacterial meningitis. In this latter indication, dexamethasone was shown to improve neurological outcome, indeed mortality in Haemophilus influenzae and Streptococcus pneumoniae meningitis.


Asunto(s)
Corticoesteroides/farmacología , Corticoesteroides/uso terapéutico , Cuidados Críticos , Choque Séptico/tratamiento farmacológico , Procedimientos Quirúrgicos Cardiovasculares , Niño , Humanos , Meningitis/tratamiento farmacológico , Enfermedades Respiratorias/tratamiento farmacológico
13.
Am J Transplant ; 6(12): 3030-6, 2006 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-17294528

RESUMEN

A 9-year-old renal transplant recipient presented with elevated serum creatinine levels 4 years post-transplant renal biopsy revealed humoral rejection including lesions suggestive for thrombotic microangiopathy (TMA). He received methylprednisolone pulses followed by a normalization of serum creatinine. Two more steroid responsive acute rejection episodes occurred. Two months later he presented rapidly progressive life threatening symptoms including bilateral pyramidal syndrome and hemoptysis. Serum haptoglobin became undetectable at this time and platelet count decreased (70000/microl), suggesting TMA. Cerebral MRI revealed generalized ischemic white matter lesions. ADAMTS13 activity decreased to < 5%. Daily plasma exchanges (PE) resulted in immediate improvement. All attempts to discontinue PE were unsuccessful. Transplantectomy resulted in normalization of generalized symptoms, hemolysis and ADAMTS13 activity (110%). Multi-organ involvement has never been reported in acquired ADAMTS13 deficiency post-transplant. Rapid resolution after transplantectomy might suggest that renal TMA was responsible for acquired ADAMTS13 deficiency and thereby triggered the generalization of TMA lesions.


Asunto(s)
Proteínas ADAM/deficiencia , Formación de Anticuerpos , Rechazo de Injerto/inmunología , Trasplante de Riñón/inmunología , Proteína ADAMTS13 , Encéfalo/patología , Isquemia Encefálica/patología , Rechazo de Injerto/patología , Humanos , Recién Nacido , Trasplante de Riñón/patología , Imagen por Resonancia Magnética , Masculino , Trasplante Homólogo
14.
Arch Mal Coeur Vaiss ; 98(5): 499-505, 2005 May.
Artículo en Francés | MEDLINE | ID: mdl-15966599

RESUMEN

OBJECTIVE: For 3 years we have used extracorporeal assistance in intensive care frequently. This study evaluates our results. METHOD: We studied the patient records for those treated between January 2002 and January 2005. The method used, indications and morbidity/mortality were analysed. RESULTS: We performed 24 circulatory assistance procedures in 20 patients (median age: 5 months), arterio-venous with oxygenation (n=18), veino-venous with oxygenation (n=3) or biventricular (n=3). The indications were post cardiotomy cardio-respiratory failure (Group I; n=20, 16 patients), pure respiratory failure (Group II: n=1), or pre-transplant/recovery (Group III: n=3). Five procedures (4 from group I and 1 from group III) required cardiac massage (no fatalities). The average duration of assistance was 7 +/- 6 days (2 to 20 days). Treatment was successfully discontinued in sixteen patients 80%), one of them thanks to heart transplant. Four (20%) died during assistance. The morbidity essentially consisted of further surgery for haemostasis, multiple transfusions, and infections. Three patients (15%) died later (1 at 17 months after discontinuation) from complications unrelated to the assistance. No neurological sequelae were noted in the survivors. CONCLUSION: These results confirm the usefulness of circulatory assistance when medical treatment has failed, particularly in the post-operative period of paediatric cardiac surgery or while awaiting transplantation.


Asunto(s)
Procedimientos Quirúrgicos Cardiovasculares , Circulación Extracorporea/métodos , Unidades de Cuidado Intensivo Pediátrico/estadística & datos numéricos , Adolescente , Adulto , Niño , Preescolar , Femenino , Trasplante de Corazón , Humanos , Lactante , Recién Nacido , Masculino , Morbilidad , Periodo Posoperatorio , Estudios Retrospectivos , Factores de Tiempo , Resultado del Tratamiento
16.
J Gynecol Obstet Biol Reprod (Paris) ; 30(2): 183-6, 2001 Apr.
Artículo en Francés | MEDLINE | ID: mdl-11319472

RESUMEN

BACKGROUND: Most cases of aortic dissection observed in women under 40 years of age occur as a complication of pregnancy in patients with other risk factors. Case report. We report a case of dissection of the ascending aorta in a young primigravida at 35 weeks gestation. The risk factor was aortic regurgitation. Multidisciplinary management enabled fetal extraction followed by repair of the aorta. Outcome was favorable for both mother and child. DISCUSSION: A review of the literature shows a variety of etiological factors leading to this disease. Emergency diagnosis and management is mandatory. Obstetricians should be aware that pregnancy can be a triggering factor in patients with a predisposition, e.g. connective tissue disease. A complete cardiovascular evaluation should be conducted before conception and a suitable surveillance planned for the entire pregnancy. The aim of this careful follow-up it to avoid surgery in an emergency setting that could compromise prognosis for both mother and child.


Asunto(s)
Enfermedades de la Aorta/terapia , Complicaciones Cardiovasculares del Embarazo/terapia , Adulto , Enfermedades de la Aorta/etiología , Enfermedades de la Aorta/cirugía , Insuficiencia de la Válvula Aórtica/etiología , Cesárea , Femenino , Edad Gestacional , Humanos , Embarazo , Resultado del Embarazo , Factores de Riesgo
17.
Cancer Res ; 60(21): 5977-83, 2000 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-11085516

RESUMEN

The important role played by the sex hormone estrogen in disease and physiological processes has been well documented. However, the mechanisms by which this hormone elicits many of its normal as well as pathological effects are unclear. To identify both known and unknown genes that are regulated by or associated with estrogen action, we performed serial analysis of gene expression on estrogen-responsive breast cancer cells after exposure to this hormone. We examined approximately 190,000 mRNA transcripts and monitored the expression behavior of 12,550 genes. Expression levels for the vast majority of those transcripts were observed to remain constant upon 17beta estradiol (E2) treatment. Only approximately 0.4% of the genes showed an increase in expression of > or =3-fold by 3 h post-E2 treatment. We cloned five novel genes (E2IG1-5), which were observed up-regulated by the hormonal treatment. Of these the most highly induced transcript, E2IG1, appears to be a novel member of the family of small heat shock proteins. The E2IG4 gene is a new member of the large family of leucine-rich repeat-containing proteins. On the basis of architectural and domain homology, this gene appears to be a good candidate for secretion in the extracellular environment and, therefore, may play a role in breast tissue remodeling and/or epithelium-stroma interactions. Several interesting genes with a potential role in the regulation of cell cycle progression were also identified to increase in expression, including Pescadillo and chaperonin CCT2. Two putative paracrine/autocrine factors of potential importance in the regulation of the growth of breast cancer cells were identified to be highly up-regulated by E2: stanniocalcin 2, a calcium/phosphate homeostatic hormone; and inhibin-beta B, a TGF-beta-like factor. Interestingly, we also determined that E2IG1 and stanniocalcin 2 were exclusively overexpressed in estrogen-receptor-positive breast cancer lines, and thus they have the potential to serve as breast cancer biomarkers. This data provides a comprehensive view of the changes induced by E2 on the transcriptional program of human E2-responsive cells, and it also identifies novel and previously unsuspected gene targets whose expression is affected by this hormone.


Asunto(s)
Estradiol/farmacología , Expresión Génica/efectos de los fármacos , Secuencia de Aminoácidos , Secuencia de Bases , Mama/efectos de los fármacos , Mama/metabolismo , Neoplasias de la Mama/genética , Neoplasias de la Mama/metabolismo , Clonación Molecular , Femenino , Perfilación de la Expresión Génica/métodos , Regulación Neoplásica de la Expresión Génica/efectos de los fármacos , Genes cdc/efectos de los fármacos , Humanos , Chaperonas Moleculares/genética , Datos de Secuencia Molecular , Proteínas de Neoplasias/biosíntesis , Proteínas de Neoplasias/genética , ARN Mensajero/análisis , ARN Mensajero/genética , Receptores de Estrógenos/biosíntesis , Receptores de Estrógenos/genética , Reproducibilidad de los Resultados , Células Tumorales Cultivadas
18.
Anal Biochem ; 285(1): 76-81, 2000 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-10998265

RESUMEN

Acetylcholinesterase is the primary target of organophosphorous and carbamate insecticides. Quantitative changes in acetylcholinesterase are suspected to confer resistance to these insecticides, but a method to estimate the amount in insect is not available. A method using irreversible inhibitors has been developed. Among the irreversible inhibitors tested, 7-(methylethoxyphosphinyloxy)-1-methylquinolinium iodide, chlorpyrifos-ethyl-oxon, and coumaphos-oxon were found to be sufficiently potent and specific.


Asunto(s)
Acetilcolinesterasa/metabolismo , Insectos/metabolismo , Animales , Sitios de Unión , Inhibidores de la Colinesterasa/metabolismo , Resistencia a los Insecticidas , Insecticidas/metabolismo
19.
Rev Med Interne ; 21(6): 505-9, 2000 Jun.
Artículo en Francés | MEDLINE | ID: mdl-10909149

RESUMEN

PURPOSE: Considering the importance to public health and the frequency with which drug addicts are imprisoned, we studied the prevalence of human immunodeficiency virus (HIV), hepatitis B virus (HBV) and hepatitis C virus (HCV), as well as drug addiction of patients admitted to the Elsau prison in Strasbourg (France). METHODS: The prospective study included all entering inmates from 1 September to 31 October 1997 (270 persons) to whom HIV, HBV and HCV blood tests were offered as well as a questionnaire on their drug addiction. RESULTS: Thirty-six percent of the entering inmates were drug addicts, of whom 1% were HIV positive, 11.2% HBV positive and 30% HCV positive, compared to, respectively, 0.6, 9.9 and 6.4% for non-drug addicts. Ninety-five of the 98 patients used several drugs, including buprenorphine for 53 patients. At the beginning of this study, buprenorphine had been available in France for 9 months. CONCLUSION: The results are to be taken seriously regarding the misuse of this product in this selected population (intravenous use, multiple drug use, dealing).


Asunto(s)
Buprenorfina/administración & dosificación , Infecciones por VIH/epidemiología , Hepatitis B/epidemiología , Hepatitis C/epidemiología , Narcóticos/administración & dosificación , Prisioneros , Trastornos Relacionados con Sustancias/complicaciones , Adulto , Femenino , Francia/epidemiología , Hepacivirus/patogenicidad , Virus de la Hepatitis B/patogenicidad , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Estudios Seroepidemiológicos
20.
Am J Bot ; 87(4): 502-7, 2000 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-10766721

RESUMEN

The clonal macrophyte Scirpus maritimus (Cyperaceae) propagates locally by rhizomes and reproduces sexually by achenes. The purpose of this paper was to examine whether in size-limited habitats in patchy and discrete marshes in two Mediterranean wetlands in southern France natural populations may suffer from a reduced maternal fecundity due to a deficit in outcross pollen. We first verified that S. maritimus suffers from a reduced fecundity when self-pollinated. At a site in the Camargue, mean fecundity (mean number of achenes per centimetre of spikelet) measured in 1995 and 1996 in seven and nine populations, respectively (surface area from 50 to 4500 m) increased significantly with population surface area in 1995 but not in 1996. In the second wetland at Roquehaute, which is composed of small ponds, fecundity was very low in all 12 local populations studied in 1996 (1.1 achenes per spikelet, SD = 1.2) and was not correlated with the population surface area (from 10 to 400 m). We performed a pollen supplementation experiment in five local populations at Roquehaute to determine whether this low fecundity may be due to a pollen limitation. A significant increase in fecundity after among-pond pollinations compared to within-pond pollinations indicated that local populations suffer from a deficit in outcross pollen, since each pond appears to contain one or a few number of clones (or incompatibility types). In S. maritimus, clonal spread may have a cost in terms of reduced fecundity in small habitats because each habitat is colonized by very few clones.

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