Your browser doesn't support javascript.
loading
Montrer: 20 | 50 | 100
Résultats 1 - 20 de 331
Filtrer
1.
Phys Rev E ; 109(1-1): 014903, 2024 Jan.
Article de Anglais | MEDLINE | ID: mdl-38366452

RÉSUMÉ

We experimentally investigate the dynamics of a sphere rolling up a granular slope. During the rolling-up motion, the sphere experiences slipping and penetration (groove formation) on the surface of the granular layer. The former relates to the stuck motion of the rolling sphere, and the latter causes energy dissipation due to the deformation of the granular surface. To characterize these phenomena, we measured the motion of a sphere rolling up a granular slope of angle α. The initial velocity v_{0}, initial angular velocity ω_{0}, angle of slope α, and density of the sphere ρ_{s} were varied. As a result, the penetration depth can be scaled solely by the density ratio between the sphere and granular layer. By considering the rotational equation of motion, we estimate the friction due to the slips. Besides, by considering energy conservation, we define and estimate the friction due to groove formation. Moreover, the translational friction is proportional to the penetration depth. Using these results, we can quantitatively predict the sphere's motion including stuck behavior.

4.
Osteoporos Int ; 31(11): 2151-2160, 2020 Nov.
Article de Anglais | MEDLINE | ID: mdl-32617610

RÉSUMÉ

Osteoporosis and atherosclerosis frequently coexist in patients with pheochromocytoma. The presence of osteoporosis may predict that of atherosclerosis and vice versa in patients with PHEO. These findings have implications for the long-term management of the pheochromocytoma and its potential chronic complications. INTRODUCTION: Pheochromocytoma (PHEO), a catecholamine-producing tumor, is often found incidentally, and it may be present for years before it is diagnosed. However, long-term exposure to catecholamines excess may induce chronic complications, such as osteoporosis and atherosclerosis. We aimed to evaluate concomitant osteoporosis and atherosclerosis in patients with PHEO. METHODS: Fifty-one patients with PHEO and 51 patients with a non-functional adrenal tumor were compared radiographically for the prevalence of vertebral fracture (VF), a typical osteoporotic fracture, and abdominal aortic calcification (AAC). RESULTS: In patients with PHEO, the prevalence of AAC was higher in those with VF (58%) than in those without (6%, p < 0.001). AAC was associated with VF after adjusting for age and sex (odds ratio, 1.53; 95% confidence interval, 1.07-2.46; p = 0.003) in patients with PHEO. The degree of catecholamine excess correlated with the presence of VF and AAC (p = 0.007). The prevalence of VF was higher in patients with PHEO (37%) than those with non-functional AT (12%, p = 0.005), but the prevalence of AAC was comparable between the two groups (25% and 19%, p = 0.636). VF and AAC more frequently coexisted in patients with PHEO (22%) than in those with non-functional AT (2%, p = 0.003). CONCLUSION: This study represents the first demonstration that osteoporosis and atherosclerosis frequently coexist in patients with PHEO. The presence of osteoporosis may predict that of atherosclerosis and vice versa in patients with PHEO. These findings have implications for the long-term management of the PHEO and its potential chronic complications.


Sujet(s)
Tumeurs de la surrénale , Athérosclérose , Ostéoporose , Phéochromocytome , Tumeurs de la surrénale/complications , Tumeurs de la surrénale/épidémiologie , Tumeurs de la surrénale/thérapie , Athérosclérose/complications , Athérosclérose/épidémiologie , Athérosclérose/thérapie , Humains , Ostéoporose/épidémiologie , Ostéoporose/étiologie , Ostéoporose/thérapie , Fractures ostéoporotiques/épidémiologie , Fractures ostéoporotiques/étiologie , Fractures ostéoporotiques/thérapie , Phéochromocytome/complications , Phéochromocytome/épidémiologie , Phéochromocytome/thérapie
7.
BJS Open ; 4(3): 456-466, 2020 06.
Article de Anglais | MEDLINE | ID: mdl-32277807

RÉSUMÉ

BACKGROUND: Although total tumour volume (TTV) may have prognostic value for hepatic resection in certain solid cancers, its importance in colorectal liver metastases (CRLM) remains unexplored. This study investigated its prognostic value in patients with resectable CRLM. METHOD: This was a retrospective review of patients who underwent hepatic resection for CRLM between 2008 and 2017 in a single institution. TTV was measured from CT images using three-dimensional construction software; cut-off values were determined using receiver operating characteristic (ROC) curve analyses. Potential prognostic factors, overall survival (OS) and recurrence-free survival (RFS) were determined using multivariable and Kaplan-Meier analyses. RESULTS: Some 94 patients were included. TTV cut-off values for OS and RFS were 100 and 10 ml respectively. Right colonic primary tumours, primary lymph node metastasis and bilobar liver metastasis were included in the multivariable analysis of OS; a TTV of 100 ml or above was independently associated with poorer OS (hazard ratio (HR) 6·34, 95 per cent c.i. 2·08 to 17·90; P = 0·002). Right colonic primary tumours and primary lymph node metastasis were included in the RFS analysis; a TTV of 10 ml or more independently predicted poorer RFS (HR 1·90, 1·12 to 3·57; P = 0·017). The 5-year OS rate for a TTV of 100 ml or more was 41 per cent, compared with 67 per cent for a TTV below 100 ml (P = 0·006). Corresponding RFS rates with TTV of 10 ml or more, or less than 10 ml, were 14 and 58 per cent respectively (P = 0·009). A TTV of at least 100 ml conferred a higher rate of unresectable initial recurrences (12 of 15, 80 per cent) after initial hepatic resection. CONCLUSION: TTV was associated with RFS and OS after initial hepatic resection for CRLM; TTV of 100 ml or above was associated with a higher rate of unresectable recurrence.


ANTECEDENTES: Aunque el volumen total del tumor (total tumour volume, TTV) puede tener valor pronóstico tras la resección hepática (hepatic resection, HR) en algunas neoplasias sólidas, no se conoce su importancia en las metástasis hepáticas de cáncer colorrectal (colorectal liver metastases, CRLMs). Este estudio analizó el valor pronóstico del TTV en pacientes con CRLMs resecables. MÉTODOS: Revisión retrospectiva de pacientes a los que se realizó una HR por CRLMs entre 2008 y 2017 en un solo centro. El TTV se estimó a partir de imágenes de tomografía computarizada utilizando un programa de reconstrucción 3D; se determinaron los valores de corte mediante un análisis de las características operativas del receptor. Se identificaron los posibles factores pronósticos y se calcularon la supervivencia global (overall survival, OS) y la supervivencia libre de recidiva (recurence-free survival, RFS) mediante análisis multivariados y de Kaplan-Meier. RESULTADOS: Se incluyeron 94 pacientes. Los valores de corte del TTV para la OS y la RFS fueron de 100 mL y 10 mL, respectivamente. En el análisis multivariable para la OS, se incluyeron los tumores del colon derecho, las metástasis linfáticas primarias y la metástasis hepática bilobar; un TTV ≥ 100 mL se asoció de forma independiente con una peor OS (cociente de riesgos instantáneos, hazard ratio, HR, 6,34, i.c. del 95% 2,08-17,9; P = 0,002). En el anáisis para la RFS, se incluyeron tumores primarios de colon derecho y las metástasis linfáticas primarias; un TTV ≥ 10 mL predijo de forma independiente una peor RFS (HR 1,90, i.c. del 95% 1,12-3,57; P = 0,017). Las tasas de OS a los 5 años con TTVs ≥ 100 mL versus < 100 mL fueron del 41% versus 67% (P = 0,006); las tasas de RFS respecto a TTVs ≥ 10 mL versus < 10 mL fueron del 14% versus 58% (P = 0,009). Un TTV ≥ 100 mL conllevó una tasa más elevada (80%) de recidivas no resecables después de la HR inicial. CONCLUSIÓN: El TTV se asoció con la RFS y la OS tras la HR por CRLMs; unos valores ≥ 100 mL conllevan una tasa más elevada de recidiva irresecable.


Sujet(s)
Tumeurs colorectales/anatomopathologie , Tumeurs du foie/secondaire , Charge tumorale , Sujet âgé , Tumeurs colorectales/mortalité , Tumeurs colorectales/chirurgie , Femelle , Humains , Japon , Tumeurs du foie/mortalité , Tumeurs du foie/chirurgie , Métastase lymphatique , Mâle , Adulte d'âge moyen , Récidive tumorale locale/chirurgie , Pronostic , Études rétrospectives , Analyse de survie , Facteurs temps
8.
J Eur Acad Dermatol Venereol ; 33(11): 2050-2057, 2019 Nov.
Article de Anglais | MEDLINE | ID: mdl-31301194

RÉSUMÉ

Although many variations of guidelines have been released, there is limited research that compares multiple treatment strategies for basal cell carcinoma (BCC). The aim of this study was to systematically review the studies reporting on multiple treatments for BCC with systematic review and network meta-analyses. Search formulas for databases, such as PubMed, EMBASE, Web of Science Core Collection and Cochrane Central Register of Controlled Trials, were created with the support of Cochrane Japan. The patient-level and tumour-level meta-analyses were performed for both the long-term treatment-failure and treatment-success. Of the 1464 studies identified from the database and hand searches, 14 met our inclusion criteria. These 14 studies included 2524 patients and 1738 tumours. Our study indicated that the incidence of treatment-failure of invasive treatments such as surgery and Mohs micrographic surgery was significantly lower than that of superficial therapies such as cryotherapy, photodynamic therapy, radiotherapy or topical therapies, in the patient-level and the tumour-level analyses, despite histological-type and pretreatment. Relapse of BCC may be a low life-threatening risk, and there are merits of non-surgical treatment. However, the significant difference in the recurrence rate is essential. Our study can provide useful guidance to clinicians in selecting treatment options for BCC.


Sujet(s)
Carcinome basocellulaire/thérapie , Tumeurs cutanées/thérapie , Humains , Méta-analyse en réseau , Facteurs temps , Échec thérapeutique
10.
Dis Esophagus ; 11(1): 28-34, 2017 Nov 01.
Article de Anglais | MEDLINE | ID: mdl-29040479

RÉSUMÉ

To clarify the quality of life of patients who underwent esophagectomy for carcinoma by right thoracotomy, laparotomy and cervical anastomosis, 116 patients who were cancer free at the time of mailing a questionnaire were analyzed. A significant decrease in vital capacity for 3 years postoperatively, as well as in the percentage of ideal body weight, between 3 and 5 years were observed in 57 patients with three-field lymphadenectomy. Patients' quality of life undergoing three-field dissection was worse than those with less radical lymphadenectomy (59 cases) in terms of the performance status and difficulty in talking at 60 months or more postoperatively. Around 20% of all patients reported severe hoarseness due to permanent recurrent nerve paralysis, resulting in poor quantity of food intake at 24 months or less postoperatively and restricted daily activity and difficulty in talking at 60 months or more after the operation. When a patient suffers from vocal cord insufficiency caused by permanent paralysis of the recurrent nerve, early treatment before discharge from the hospital should be performed to improve the quality of life of such a patient.


Sujet(s)
Carcinomes/chirurgie , Tumeurs de l'oesophage/chirurgie , Oesophagectomie/effets indésirables , Lymphadénectomie/effets indésirables , Qualité de vie , Paralysie des cordes vocales/étiologie , Sujet âgé , Perte sanguine peropératoire , Femelle , Volume expiratoire maximal par seconde , Enrouement/étiologie , Humains , Longévité , Lymphadénectomie/méthodes , Mâle , Adulte d'âge moyen , Durée opératoire , Lésions du nerf laryngé récurrent/complications , Parole , Enquêtes et questionnaires , Capacité vitale , Perte de poids
11.
J Hosp Infect ; 94(2): 150-3, 2016 Oct.
Article de Anglais | MEDLINE | ID: mdl-27346624

RÉSUMÉ

Inpatients who had been in close contact with patients with influenza were given oseltamivir [75mg capsules once daily for adults or 2mg/kg (maximum of 75mg) once daily for children] for three days as postexposure prophylaxis (PEP). The index patients with influenza were prescribed a neuraminidase inhibitor and were discharged immediately or transferred to isolation rooms. The protective efficacy of oseltamivir for three days was 93% overall [95% confidence interval (CI) 53-99%; P=0.023] and 94% for influenza A (95% CI 61-99%; P=0.017), which is comparable to that of seven- to 10-day regimens of oseltamivir as PEP.


Sujet(s)
Antiviraux/administration et posologie , Chimioprévention/méthodes , Grippe humaine/prévention et contrôle , Oséltamivir/administration et posologie , Prophylaxie après exposition/méthodes , Adulte , Sujet âgé , Femelle , Humains , Mâle , Adulte d'âge moyen , Résultat thérapeutique
14.
Transplant Proc ; 46(3): 797-803, 2014 Apr.
Article de Anglais | MEDLINE | ID: mdl-24767352

RÉSUMÉ

BACKGROUND: Along with an increased number of cases of liver transplantation (LT), perioperative mortality has decreased and short-term survival has improved. However, long-term complications have not been fully elucidated today. PURPOSE: Chronic complications were analyzed individually to find risk factors and to improve long-term outcomes after LT. SUBJECTS: There were 63 cases of LT from our outpatient clinic that were included in this study. Among them, 58 were performed using living donor LT and 5 were performed using deceased donor LT. Original diseases mainly consisted of hepatitis C virus (HCV; 45.9%) and hepatitis B virus (23.0%). FINDINGS: The median follow-up was 5.4 ± 3.3 years (range, 0.1∼17 years). Overall survival at 2, 3, 5, and 10 years was 89.3%, 83.4%, 81.3%, and 81.3%, respectively. Long-term complications mainly consisted of renal dysfunction (62.7%), dyslipidemia (29.4%), diabetes mellitus (21.6%), and arterial hypertension (21.6%). In univariate analysis, HCV (P = .03) and elapsed years after LT (P = .02) were identified as predictive factors for arterial hypertension and recipient age >50 (P = .03), and elapsed years after LT for renal dysfunction (P = .03), respectively. In multivariate Cox regression analysis, HCV (odds ratio [OR] 5.25, 95% confidence interval [CI] 1.05-34.06, P = .04) was identified as a predictive factor for arterial hypertension, and recipient age older than 50 years for renal dysfunction (OR 5.67, 95% CI 1.34-28.88, P = .02). The number of elapsed years after transplantation was also identified as a predictive factor for arterial hypertension/dyslipidemia/renal dysfunction (OR 13.88/14.15/4.10, 95% CI 1.91-298.26/2.18-290.78/1.09-18.03, P = .01/.003/.04). Fifty percent of the recipients developed renal dysfunction within 8 years after LT, and fluctuation of estimated glomerular filtration rate (eGFR) within 3 months after LT was successfully associated with an annual decrease of eGFR (r(2) value = 0.574, P < .0001). CONCLUSION: Renal dysfunction is the most frequent chronic complication after LT. As chronic individual eGFR can be now accurately predicted with deterioration speed, recipient strata for renal protection strategies should be precisely targeted.


Sujet(s)
Transplantation hépatique/effets indésirables , Adulte , Sujet âgé , Cause de décès , Débit de filtration glomérulaire , Humains , Adulte d'âge moyen , Donneurs de tissus
15.
Transplant Proc ; 46(3): 958-62, 2014 Apr.
Article de Anglais | MEDLINE | ID: mdl-24767390

RÉSUMÉ

BACKGROUND: Living donor pancreas transplantation (LDPT) reduces the number of deaths of diabetic patients on dialysis and of candidates on the waiting lists and helps to overcome the organ shortage. Stringent criteria must be applied to minimize the risk of metabolic complications for living donors. The Japanese Pancreas and Islet Transplantation Association (JPITA) proposed LDPT guidelines in 2010. In this study, we retrospectively evaluated glucose metabolism of the patients who underwent distal pancreatectomy (DP) according to the donor criteria of the LDPT guidelines proposed by the JPITA. METHODS: Fifty-two nondiabetic patients who underwent DP were divided into 2 groups according to the donor criteria: indication group (IG, n = 14) who had age ≤ 65, hemoglobin A1c (HbA1c) < 5.9%, and body mass index (BMI) < 25 kg/m(2). The other patients were placed in the no indication group (NG, n = 38). Clinical data and percent resected volume (PRV) of each pancreas as determined by multi-detector row computed tomography volumetry were compared between the 2 groups. RESULTS: During the follow-up period (median 12 months), 14 patients (27%) developed new-onset diabetes within a median onset time of 10 months (range 3-24 months) postoperatively. No patient in the IG developed new-onset diabetes. On the other hand, 37% of the patients in the NG developed new-onset diabetes. There were significant between-group differences in changes in preoperative serum fasting glucose and HbA1c levels, whereas there were no significant between-group differences in preoperative serum albumin or body weight. Multivariate analysis identified preoperative HbA1c (odds ratio 51.6, P = .002) and PRV (odds ratio 2.07, P = .033) as independent risk factors for new-onset diabetes. CONCLUSION: Living donor criteria in the LDPT guidelines proposed by the JPITA are appropriate for prevention of glucose metabolic complications in donors. Further long-term follow-up studies of living donors' metabolic function are needed to clarify the safety of the donor.


Sujet(s)
Glucose/métabolisme , Transplantation d'ilots de Langerhans , Donneur vivant , Transplantation pancréatique , Pancréatectomie/méthodes , Guides de bonnes pratiques cliniques comme sujet , Sociétés médicales , Donneurs de tissus , Femelle , Humains , Japon , Mâle , Adulte d'âge moyen
16.
Transplant Proc ; 46(3): 989-91, 2014 Apr.
Article de Anglais | MEDLINE | ID: mdl-24767399

RÉSUMÉ

Graft thrombosis is the most common cause of early graft loss after pancreas transplantation. The grafted pancreas is difficult to salvage after complete thrombosis, especially arterial thrombosis, and graft pancreatectomy is required. We describe a patient presenting with a functioning pancreas graft with thromboses of the splenic artery (SA) and superior mesenteric artery (SMA) after simultaneous pancreas-kidney transplantation (SPK). A 37-year-old woman with a 20-year history of type 1 diabetes mellitus underwent SPK. The pancreaticoduodenal graft was implanted in the right iliac fossa with enteric drainage. A Carrel patch was anastomosed to the recipient's right common iliac artery, and the graft gastroduodenal artery was anastomosed to the common hepatic artery using an arterial I-graft. The donor portal vein was anastomosed to the recipient's inferior vena cava. Four days after surgery, graft thromboses were detected by Doppler ultrasound without increases in the serum amylase and blood glucose levels. Contrast enhanced computed tomography revealed thromboses in the SA, splenic vein and SMA. Selective angiography showed that blood flow was interrupted in the SA and SMA. However, pancreatic graft perfusion was maintained by the I-graft in the head of the pancreas and the transverse pancreatic artery in the body and tail of the pancreas. We performed percutaneous direct thrombolysis and adjuvant thrombolytic therapy. However, we had to stop the thrombolytic therapy because of gastrointestinal hemorrhage. Thereafter, the postoperative course was uneventful and the pancreas graft was functioning with a fasting blood glucose level of 75 mg/dL, HbA1c of 5.1%, and serum C-peptide level of 1.9 ng/mL at 30 months post-transplantation.


Sujet(s)
Transplantation rénale/effets indésirables , Artères mésentériques/anatomopathologie , Transplantation pancréatique/effets indésirables , Thrombose/anatomopathologie , Adulte , Femelle , Humains
17.
Clin Exp Dermatol ; 39(3): 284-91, 2014 Apr.
Article de Anglais | MEDLINE | ID: mdl-24635062

RÉSUMÉ

BACKGROUND: Drug-induced hypersensitivity syndrome/drug rash with eosinophilia with systemic symptoms (DIHS/DRESS) is a severe drug eruption accompanied by multiorgan disorders. Several unique aspects of DIHS/DRESS, including herpesvirus reactivation, liver dysfunction and hypogammaglobulinaemia, have similarities to graft-versus-host disease (GVHD). AIM: In this study, we focused on the dynamics of regulatory T cells (Tregs) infiltrating into the skin lesions of DIHS/DRESS and GVHD. METHODS: Skin biopsies were taken from patients with DIHS/DRESS, GVHD, or maculopapular drug eruption. Tregs were detected using immunostaining with anti-FoxP3. RESULTS: The ratio of FoxP3+ T cells to CD3+ T cells was significantly higher in the skin lesions of patients with DIHS/DRESS than in those of patients with GVHD, and was positively correlated with the number of days from disease onset in the acute phase. CONCLUSIONS: The dynamics of Tregs in skin lesions are different between DIHS/DRESS and GVHD, despite there being many similarities between these conditions.


Sujet(s)
Toxidermies/anatomopathologie , Facteurs de transcription Forkhead/métabolisme , Maladie du greffon contre l'hôte/anatomopathologie , Lymphocytes T régulateurs/anatomopathologie , Adolescent , Adulte , Sujet âgé , Toxidermies/immunologie , Éosinophilie/anatomopathologie , Exanthème/anatomopathologie , Femelle , Maladie du greffon contre l'hôte/immunologie , Transplantation de cellules souches hématopoïétiques , Humains , Immunohistochimie , Mâle , Adulte d'âge moyen , Lymphocytes T régulateurs/métabolisme , Jeune adulte
18.
Mol Plant Microbe Interact ; 25(11): 1419-29, 2012 Nov.
Article de Anglais | MEDLINE | ID: mdl-22835272

RÉSUMÉ

The rough lemon pathotype of Alternaria alternata produces host-selective ACR-toxin and causes Alternaria leaf spot disease of rough lemon (Citrus jambhiri). The structure of ACR-toxin I (MW = 496) consists of a polyketide with an α-dihydropyrone ring in a 19-carbon polyalcohol. Genes responsible for toxin production were localized to a 1.5-Mb chromosome in the genome of the rough lemon pathotype. Sequence analysis of this chromosome revealed an 8,338-bp open reading frame, ACRTS2, that was present only in the genomes of ACR-toxin-producing isolates. ACRTS2 is predicted to encode a putative polyketide synthase of 2,513 amino acids and belongs to the fungal reducing type I polyketide synthases. Typical polyketide functional domains were identified in the predicted amino acid sequence, including ß-ketoacyl synthase, acyl transferase, methyl transferase, dehydratase, ß-ketoreductase, and phosphopantetheine attachment site domains. Combined use of homologous recombination-mediated gene disruption and RNA silencing allowed examination of the functional role of multiple paralogs in ACR-toxin production. ACRTS2 was found to be essential for ACR-toxin production and pathogenicity of the rough lemon pathotype of A. alternata.


Sujet(s)
Alternaria/enzymologie , Alternaria/métabolisme , Citrus/microbiologie , Protéines fongiques/métabolisme , Polyketide synthases/métabolisme , Alternaria/génétique , Protéines fongiques/génétique , Données de séquences moléculaires , Cadres ouverts de lecture/génétique , Polyketide synthases/génétique
19.
Transpl Infect Dis ; 14(4): E1-6, 2012 Aug.
Article de Anglais | MEDLINE | ID: mdl-22487245

RÉSUMÉ

Linezolid (LZD) is the first oxazolidinone antibiotic that is effective against drug-resistant gram-positive organisms. Hematological toxicities such as thrombocytopenia, anemia, and leukocytopenia are common in LZD therapy. However, LZD-induced pure red cell aplasia (PRCA) is very rare. A 56-year-old man with myelodysplastic syndrome underwent allogeneic bone marrow transplantation from a human leukocyte antigen-matched and ABO blood type-matched unrelated male donor. He had bacteremia caused by Staphylococcus epidermidis after engraftment of neutrophils and red blood cells. We first administered vancomycin, but then changed to intravenous LZD because of kidney damage. Two weeks after LZD therapy, the patient's hemoglobin and reticulocyte levels were 6.8 g/dL and 0.3%, respectively. Bone marrow examination revealed red blood cell aplasia (myeloid/erythroid ratio was 402). The patient showed rapid recovery of normal erythropoiesis within 2 weeks of LZD cessation. It is important to be aware of the hematological effects associated with LZD in the setting of stem cell transplantation,particularly for those with pre-existing myelosuppression, renal insufficiency, and those receiving concomitant drugs that produce bone marrow suppression. We advocate that a reticulocyte count be performed periodically for detecting bone marrow suppression, including PRCA, during LZD therapy.


Sujet(s)
Acétamides/effets indésirables , Anti-infectieux/effets indésirables , Bactériémie/traitement médicamenteux , Oxazolidinones/effets indésirables , Érythroblastopénie chronique acquise/induit chimiquement , Staphylococcus epidermidis/effets des médicaments et des substances chimiques , Transplantation de cellules souches/effets indésirables , Transplantation homologue/effets indésirables , Acétamides/usage thérapeutique , Bactériémie/microbiologie , Humains , Linézolide , Mâle , Adulte d'âge moyen , Oxazolidinones/usage thérapeutique , Infections à staphylocoques/traitement médicamenteux , Infections à staphylocoques/microbiologie
20.
Bull Entomol Res ; 102(2): 157-64, 2012 Apr.
Article de Anglais | MEDLINE | ID: mdl-21944472

RÉSUMÉ

A serious sugarcane pest, Dasylepida ishigakiensis, remains in the soil during most of its life cycle except for a short period for mating. Mating disruption by an artificial release of the sex pheromone (R)-2-butanol (R2B), therefore, may be a feasible method to control this pest. We examined the effects of artificial release of R2B and its related compounds, (S)-2-butanol (S2B) and the racemic 2-butanol (rac-2B), on the mating success of this beetle both in the laboratory and in the field. In flight tunnel experiments, almost all males orientated towards a R2B-releasing source and 40% of them landed on the source. When the atmosphere was permeated with R2B, the frequency of males landing on the model was significantly reduced. Both rac-2B and S2B were less effective, but substantial reduction in landing success by males was achieved at higher rac-2B concentrations. R2B released from polyethylene dispensers in sugarcane plots greatly reduced not only the proportion of females mated with males but also the number of males caught by R2B-baited traps, indicating that male mate-searching behaviour was strongly affected by the released R2B. Similar inhibitory effects on male behaviour were also observed when tube- or rope-type dispensers released high rac-2B concentrations in the field. These results indicate that it would be highly possible to control D. ishigakiensis through the disruption of the sexual communication by releasing either synthetic R2B or rac-2B.


Sujet(s)
Butanols/pharmacologie , Coléoptères/physiologie , Lutte contre les insectes/méthodes , Lutte biologique contre les nuisibles/méthodes , Phéromones sexuelles/pharmacologie , Animaux , Butanols/composition chimique , Coléoptères/effets des médicaments et des substances chimiques , Femelle , Lutte contre les insectes/instrumentation , Japon , Mâle , Préférence d'accouplement chez les animaux , Lutte biologique contre les nuisibles/instrumentation , Reproduction , Saccharum , Phéromones sexuelles/composition chimique , Stéréoisomérie
SÉLECTION CITATIONS
DÉTAIL DE RECHERCHE
...