Effects of habitat on individual reproductive success of mature male parr of Atlantic salmon Salmo salar.

The effect of the presence of stone blocks in the spawning habitat on the reproductive success of mature male parr of Atlantic salmon Salmo salar of various sizes and ages was tested in an artificial channel. Shelters allowed smaller individuals to contribute to egg fertilization as much as large parr, suggesting that the size-based dominance observed in a shelterless habitat was not maintained in a more complex habitat.

Wireless capsule endoscopy versus ileocolonoscopy for the diagnosis of postoperative recurrence of Crohn's disease: a prospective study.

BACKGROUND AND AIMS: Following ileocolonic resection for Crohn's disease (CD), early endoscopic recurrence predicts recurrence of symptoms. The aim of the study was to compare ileocolonoscopy and wireless capsule endoscopy (WCE) for the detection of postoperative recurrence in CD. METHODS: WCE and ileocolonoscopy were performed within six months following surgery in 32 prospectively enrolled patients. Two independent observers interpreted the results of WCE. Recurrence in the neoterminal ileum was defined by a Rutgeerts score>or=1. When observers at WCE did not concur, WCE results were considered as either true negative or true positive and sensitivity and specificity were calculated according to both assumptions. RESULTS: Recurrence occurred in 21 patients (68%) and was detected by ileocolonoscopy in 19 patients. Sensitivity was 90% and specificity 100%. Sensitivity of WCE was 62% and 76% and specificity was 100% and 90%, respectively, depending on assumptions. There was a correlation between the severity of the lesions measured by both methods (p<0.05). Lesions located outside the scope of conventional endoscopy were detected by WCE in two thirds of patients with excellent interobserver agreement (kappa>0.9) for all lesions with the exception of ulceration (kappa=0.7). CONCLUSIONS: The sensitivity of WCE in detecting recurrence in the neoterminal ileum was inferior to that of ileocolonoscopy. In contrast, WCE detected lesions outside the scope of ileocolonoscopy in more than two thirds of patients. Additional follow up studies are needed to assess the clinical relevance of such lesions. At the present time, it seems that WCE cannot systematically replace ileocolonoscopy in the regular management of patients after surgery.

Study of effects of Bt maize (Zea mays) events on Lepidoptera Ostrinia nubilalis, Sesamia nonagrioidesin southwestern France.

Crops of maize (Zea mays L.) were conducted in southwestern France with GMO (Genetic Modified Organism) vs isogenetic varieties in order to verify the control of European Corn Borer (ECB) Ostrinia nubilalis (Hübner) and the Corn Stalk Borer (CBS) Sesamia nonagrioides (Lefevbre) by GMO in field conditions. The bioassays were carried out in 1998 and 1999 before moratorium, then in 2005. Experiments involved respectively 18, 12 and 19 fields cultivated with Furio/Furio cb (GMO), Cecilia/ Elgina (GMO) and PR33P66/PR33P67 (GMO) varieties. These transgenic events expressed Cry1A(b) protein (Bt maize). Plants were noted for insect infestation assessment (number of larvae in stalks and ears per plant). Statistical tests used t-test on couple of plots. Results showed a significant difference in the density of both ECB and CBS between control and the two transgenic events. The two transgenic events acted differently. The control of the two Bt events on the two pests were differentiated and discussed. These experiments underlined the importance of field evaluation for testing real effects of transgenic events on crop according the environmental context.

A density-dependent model with reinvasion for estimating tsetse fly populations (Diptera: Glossinidae) through trapping.

A simple density-dependent reinvasion model is described and used to estimate tsetse fly populations on the basis of removal trapping experiments. The model was tested on Glossina fuscipes fuscipes Newstead in the Central African Republic and G. palpalis palpalis (Robineau-Desvoidy) in the Republic of Congo (Brazzaville). The density-dependence is modelled by postulating that the inflow of flies each day is proportional to the deficit relative to the equilibrium population. Non-linear least square techniques were used to estimate the following parameters: the daily capture rate, the strength of the density-dependence, and the equilibrium fly population, at the beginning and at the end of the trapping experiment. The model ignores birth and death rates of flies and is applicable only when a rapid decrease in population occurs over a short period (between 10 and 20 days). Over longer periods one could not ignore the natural growth of the populations as well as other more complex density-dependent mechanisms.

Comparison between dipyridamole and adenosine as pharmacologic coronary vasodilators in detection of coronary artery disease with thallium 201 imaging.

BACKGROUND: Both dipyridamole and adenosine are widely used as pharmacologic stressors with 201Tl imaging for detection of coronary artery disease. The purpose of this study was to compare dipyridamole and adenosine 201Tl imaging directly in patients with angiographically proved coronary artery disease. METHODS AND RESULTS: Fifty-four patients were submitted to two planar 201Tl studies: one with dipyridamole and the other with adenosine. The interval between the two studies varied from 2 to 7 days and the order was assigned randomly. Three standard planar views were obtained 10 minutes and 4 hours after the injection of 3.0 mCi 201Tl. Administration of dipyridamole was as follows: 0.142 mg/kg/min during 4 minutes, followed by a slight exercise and 201Tl injection. The infusion of adenosine was as follows: 0.140 mg/kg/min during 6 minutes with injection of 201Tl after the third minute of infusion. Patients were asked to give their preference considering the number, type, severity, and duration of side effects on a scale from 0 (worst) to 5 (best). Reading was done by two experienced observers. The heart was divided into three segments per view. The change in systolic blood pressure was -12 +/- 11 mm Hg for adenosine and -5 +/- 10 mm Hg for dipyridamole (p < 0.001), and the change in heart rate was 18 +/- 10 beats/min for adenosine and 8 +/- 7 beats/min for dipyridamole (p < 0.001). With regions of interest, ischemic/normal wall ratios were determined: 0.78 +/- 0.06 for adenosine and 0.83 +/- 0.08 for dipyridamole (p < 0.001). Adenosine detected 295 normal, 170 ischemic, and 21 scar segments, whereas dipyridamole detected 326, 135, and 25 segments, respectively. Patients preferred adenosine (4.3 +/- 1.0 for adenosine vs 3.8 +/- 1.5 for dipyridamole; p < 0.04) mainly because of the short duration of side effects. CONCLUSION: This study shows that the use of adenosine with 201Tl imaging may have some advantages over dipyridamole.

Egg dispersion in codling moth: Influence of egg extract and of its fatty acid constituents.

Codling moth females (Cydia pomonella, Lepidoptera: Tortricidae) (CM) usually lay single eggs and have a tendency to disperse. In a first experiment we observed that single females exposed to 20 apples distribute their eggs regularly among apples, suggesting a dispersive oviposition behavior. In a dual-choice situation, isolated females avoided oviposition on areas of cardboard treated with a methylene dichloride egg extract at the dose of ca. 1.0 egg equivalent/cm(2). A strong avoidance was obtained in response to a 20-fold dose, which was accompanied by a significant reduction of total oviposition. Seven major compounds found by GC analyses in the methylene dichloride extract of 2 to 3-day-old eggs were saturated or unsaturated C14-C18 straight-chain fatty acids: myristic acid, palmitic acid, palmitoleic acid, stearic acid, oleic acid, linoleic acid, and linolenic acid. This was confirmed by GC-MS analysis of an extract made by ethyl ether. Smaller amounts of three methyl esters were also identified as methyl myristate, methyl palmitate, and methyl stearate. A blend of the seven fatty acids (FA) mimicked rather well the avoidance provoked by the extract, and this avoidance was confirmed by choice between treated and untreated fruits by single females. The treatment of apples with the 7FA mixture induced an aggregative distribution of the eggs among apples. We also found that the amounts of fatty acids harvested in the extract depend on the egg age. Amounts of fatty acids increased until eggs were 4 days old and then decreased before hatching. In this paper we discuss the possible role of simple molecules, such as fatty acids and their esters, as semiochemicals indicative of juvenile tissues.

To penetrate or not to penetrate? A behavioral choice by bean beetle first-instar larvae in response toPhaseolus vulgaris seed surface quality.

Survival ofAcanthoscelides obtectus larvae depends on the ability of the first instar to pierce the seed coat ofPhaseolus vulgaris, which represents a critical sequence because of physical characteristics and toxicity. We have investigated the influence of seed surface quality on larval boring behavior by the usual method of surface washing with different solvents, or by removing the testa, or by coating the testa with a polymer spray. Observations were made on isolated larvae in no-choice and dual-choice bioassays. In the no-choice situation, larval penetration was reduced after seed coats were soaked with chloroform, whereas water, diethyl ether, or methanol had no significant effect. The ratio of boring attempts to successful penetrations was increased on seeds washed with chloroform. In the dual-choice situation, larvae avoided artificially coated seeds and preferred untreated seeds over those washed with chloroform or methanol. These results indicate that boring stimulants exist on the seed coat and that they are removed by chloroform and methanol or made inaccessible by artificial coating. The high mortality of first instars on seeds washed with these two solvents is attributed to a lack of chemicals necessary to initiate and sustain boring behavior, causing larval stress, possibly due to prolonged locomotory activity and starvation. Thus, seed coat quality may influence the population dynamics ofA. obtectus.

Comparison between technetium-99m-teboroxime and thallium-201 dipyridamole planar myocardial perfusion imaging in detection of coronary artery disease.

Technetium-99m (TC-99m)-teboroxime is a new myocardial perfusion imaging agent. The purpose of this prospective study was to compare Tc-99m-teboroxime with thallium-201 imaging after the administration of dipyridamole. Thirty patients referred for the evaluation of chest pain were studied with both thallium-201 and Tc-99m-teboroxime dipyridamole scans (mean interval 2 days). Dipyridamole was administered at 0.142 mg/kg/min for 4 minutes. Planar imaging (3 standard views) was obtained at 5 and 240 minutes after the injection of 2.2 mCi of thallium-201. Tc-99m-teboroxime (18 to 25 mCi) was injected after dipyridamole infusion. A second injection, at rest, was repeated 4 hours later. Planar imaging (3 standard views of 1 minute/view for the first 2 views, and 90 seconds for the last view) was obtained 2 minutes after Tc-99m-teboroxime injection. Blinded reading was performed by 3 observers. Thallium-201 showed perfusion defects in 182 myocardial segments corresponding to 33 of 45 (73%) significantly stenosed coronary arteries (greater than or equal to 70% reduction in endoluminal diameter), and Tc-99m-teboroxime detected 160 abnormal segments corresponding to 29 of 45 (64%) stenosed arteries. Thallium-201 and Tc-99m-teboroxime studies were normal in 3 patients. In conclusion, this study shows that there is a good correlation in the imaging results found with thallium-201 and Tc-99m-teboroxime using dipyridamole infusion on both a segmental and a diagnostic comparison.

Change in amplitude distributions of Doppler spectrograms recorded below the aortic valve in patients with a valvular aortic stenosis.

Amplitude distributions of Doppler spectrograms were characterized in a group of 22 patients having no aortic pressure gradient and another group of 26 patients having a stenotic aortic valve. Specifically, for each patient, the ratios of the mean amplitude in three normalized frequency bands (low, middle and high) to the mean amplitude of the Doppler spectrogram computed in selected portions of the systolic period were considered. Pulsed-wave Doppler spectrograms were recorded by positioning the sample volume in the left ventricular outflow tract, approximately 1 cm below the aortic valve. Statistically significant differences were found between the middle (p = 0.041) and high (p = 0.028) frequency bands of Doppler signals recorded from the two groups of patients. The differences observed are believed to be attributed to blood flow eddies generated below the stenotic aortic heart valve and to changes in blood flow orientation.

Platelet peroxidase deficiency in a case of myelodysplastic syndrome with myelofibrosis.

Morphological and functional abnormalities of the megakaryocytic series have been well described in myelodysplastic syndromes. Platelet peroxidase has always been demonstrated in abnormal megakaryocytes and early megakaryoblasts in such syndromes. We have studied a case of myelodysplastic syndrome with marked morphological abnormalities of megakaryocytes in which ultrastructural studies showed the coexistence of platelet peroxidase positive and platelet peroxidase negative megakaryocytes. This enzymatic deficiency was confirmed by the ultrastructural study of circulating platelets. This case appears to be the first report of a partial platelet peroxidase deficiency. It adds to the enzymatic abnormalities in myelodysplastic syndrome already described for the red cells and the granulocytic cells.