Vascularization and Production of Mitogenic Factor(S) in Domestic Cat (Felis catus) Testes: Preliminary Results

Some male seasonal breeders are known to undergo testicular growth and regression throughout the year. The periodic and fast physiological development and regression processes, with simultaneous fast changes in blood flow, appears to be stimulated by angiogenic substances and inhibited by anti-angiogenic factors. The objective of this study was to evaluate the effect of season on microvascularization and production of angiogenic factors by testicular tissue, using the male cat as a model. Monthly, testes were collected post mortem from domestic stray cats, for histology and for tissue culture. Testis explants were cultured for 18h and conditioned media were tested for their ability to stimulate mitogenesis of bovine aortic endothelial cells (BAEC). Vascular endothelial growth factor (VEGF) was used as a positive control. Proliferative response of BAEC to samples was evaluated by determining the number of cells in each well using a Neubauer chamber. Vascular density was assessed by a computerized image analysis ('Scion Image, NIH, USA') based on the total histological area occupied by the vascular lumen. Percentage data subjected to arcsine transformation were analysed by one-way ANOVA and post-comparison tests. There was a significant increase in microvascular areas in November ( P  < 0.001), when compared to the remaining months (LSD test). All cat testicular tissue showed the capability to increase BAEC proliferation, when compared to negative controls, throughout the study. However, there was an increase in BAEC mitogenesis in February ( P  < 0.05) and November ( P  < 0.001), when compared to the other months. Our data show that cat testicular tissue from different periods of the year stimulates angiogenic factor(s). Furthermore, changes in angiogenesis may play a role on vascular growth and regression of the testes during the breeding and non-breeding season in the male cat.     

Insecticide resistance status of Bemisia tabaci Q‐biotype in south‐eastern Spain

BACKGROUND: Bemisia tabaci Gennadius Q‐biotype has readily developed resistance to numerous insecticide classes. Studies in the Mediterranean area are needed to clarify the resistance status and cross‐resistance patterns in this invasive whitefly biotype. The levels of resistance in nymphs of seven strains of B. tabaci Q‐biotype from south‐eastern Spain to representative insecticides were determined. RESULTS: Six populations had low to moderate levels of resistance to azadirachtin (0.2‐ to 7‐fold), buprofezin (11‐ to 59‐fold), imidacloprid (1‐ to 15‐fold), methomyl (3‐ to 55‐fold), pyridaben (0.9‐ to 9‐fold), pyriproxyfen (0.7‐ to 15‐fold) and spiromesifen (1‐ to 7‐fold), when compared with a contemporary Spanish Q‐biotype reference population (LC₅₀ = 2.7, 8.7, 15.2, 19.9, 0.34, 20.9 and 1.1 mg L^?1 respectively). A single population collected from a greenhouse subject to intensive insecticide use exhibited generally higher resistance levels to the same array of compounds (31‐, 1164‐, 3‐, 52‐, 9‐, 19‐ and 3‐fold respectively). Pyridaben and spiromesifen were extremely effective against nymphs of all strains, with LC₅₀ values significantly below recommended application rates. CONCLUSION: In contrast to previous reports, high rates of efficacy exist for numerous insecticide classes against B. tabaci Q‐biotype populations in these intensive agricultural regions of south‐eastern Spain. This probably reflects the recent and significant reductions in exposure that have resulted from a wider uptake of IPM technologies and strategies. However, the continued presence of resistance genes also suggests that a reversion to levels of high insecticide exposure could result in a rapid selection for resistance. Copyright © 2009 Society of Chemical Industry     

Detection and differentiation of several food-spoilage lactic acid bacteria by multiplex polymerase chain reaction, capillary gel electrophoresis, and laser-induced fluorescence

In this work, a complete analytical procedure is investigated to differentiate several food-spoilage lactic acid bacteria. To do that, a method involving multiplex Polymerase Chain Reaction (PCR), capillary gel electrophoresis (CGE), and laser-induced fluorescence (LIF) is developed. The PCR-CGE-LIF protocol allows the simultaneous detection and differentiation of the genera Leuconostoc and Carnobacterium, the nonmotile group of species within the genus Carnobacterium, and the three species of the group individually (C. divergens, C. gallinarum, and C. maltaromicum). The capability of this approach is clearly illustrated through the sensitive and efficient analysis of the two closest amplicons, with sizes equal to 397 and 412 bp, showing very different yields in all of the amplification reactions tested. These two fragments, which could not be resolved by agarose gel electrophoresis (AGE), are clearly distinguishable by CGE-LIF even when very different areas for both peaks are obtained. The PCR-CGE-LIF method also allows the sensitive detection of these bacteria, demonstrating both a significant resolution improvement compared with traditional AGE and the usefulness of this approach to solve real-life analytical challenges. Good reproducibility of the CGE-LIF procedure is shown for the analysis of multiplex PCR samples with percent relative standard deviation values for migration times and corrected peak areas as low as 0.80 and 6.50 for the same sample and three different days (n = 12), respectively.     

Calcium oxalate: crystallographic analysis in solid aggregates in urinary sediments

A relationship between crystallographic structure and morphological form of calcium oxalates in urinary sediments is established. The common tetragonal bipyramids have been confirmed as weddellite from their electron diffraction patterns. Other solid forms, such as needles, biconcave disks, and dumbbell forms, that can appear in hyperoxalurias, of both metabolic and alimentary origin, have been identified as whewellite. Micrographs reveal fibrous structure on those whewellite polycrystalline aggregates.     

Genetic improvement of Orius laevigatus for better fitness feeding on pollen

Journal of Pest Science - In many protected crops, augmentative biological control heavily relies on generalist predators, which continuous presence on the crop allows an early response to pest...     

Quiet Zone Within a Seismic Gap near Western Nicaragua: Possible Location of a Future Large Earthquake

A 5700-square-kilometer quiet zone occurs in the midst of the locations of more than 4000 earthquakes off the Pacific coast of Nicaragua. The region is indicated by the seismic gap technique to be a likely location for an earthquake of magnitude larger than 7. The quiet zone has existed since at least 1950; the last large earthquake originating from this area occurred in 1898 and was of magnitude 7.5. A rough estimate indicates that the magnitude of an earthquake rupturing the entire quiet zone could be as large as that of the 1898 event. It is not yet possible to forecast a time frame for the occurrence of such an earthquake in the quiet zone.     

Positive Effects of Melatonin Treatment on the Reproductive Performance of Young Border Leicester Rams Mated to Merino Ewes in Spring: Preliminary Observations

Poor reproductive performance of Merino ewe flocks when mated to Border Leicester rams during spring may be due to seasonality of the Border Leicester breed. Two approaches were taken to test this assumption. Six young (12 months old) or six mixed‐age (12, 24 and ≥36 months old) Border Leicester rams were either treated or not treated with melatonin implants (2 × 2 design) 6 weeks before the four groups of rams were each put with approximately 300 Merino ewes for an 8‐week mating period. Implants were inserted in early September (experiment 1). The second approach was to yard or not yard ewes and mixed‐age rams on several occasions during the first 3 weeks of the mating period (experiment 2). Pregnancy rate and twinning percentage were assessed by ultrasonography. In experiment 1, melatonin treatment in young rams increased (p < 0.001) pregnancy rate from 5.0% to 92.6%, but mixed‐age rams did not respond (90.7% vs 89.5% for melatonin and non‐melatonin treatments, respectively). Twinning rate was similar (p > 0.05) for ewes mated to either melatonin or non‐melatonin‐treated young rams (36.8% vs 40.0%, respectively), whereas melatonin significantly improved (p < 0.05) twinning rate in those ewes mated to mixed‐age rams (49.1% vs 36.1%). After 6 weeks of melatonin treatment, scrotal circumference was greater (p < 0.05) in both young and mixed‐aged rams than in untreated counterparts. In experiment 2, yarding of ewes and rams overnight on several occasions early in the mating period reduced (p < 0.001) pregnancy rate compared with non‐yarded counterparts (89.5% vs 65.5%). Twinning rate was not affected (37.7% vs 36.1%, respectively). In summary, melatonin treatment of Border Leicester rams significantly improved flock reproductive performance in spring due to improved pregnancy rates with young rams and improved litter size with mixed‐age rams.     

In vitro multiplication of Cryptosporidium parvum in mouse peritoneal macrophages.

Cryptosporidium parvum of bovine origin was developed in vitro in unsensitized mouse peritoneal macrophages. Macrophages growing in RPMI medium were infected with sporozoites or with oocysts, and after staining infections were studied by light microscopy. A high parasitic index was obtained with multiple infections occurring commonly. This is a simple method for the study of Cryptosporidium biology, and for in vitro assays of pharmacological activity.     

Responses of annual bluegrass (Poa annua L.) and creeping bentgrass (Agrostis palustris Huds.) seedlings to nitrogen,phosphorus and potassium†

The growth response to fertilizer under different soil texture (light clayey soil and composite soil consisting of the light clayey soil and sand), and the timing of N fertilization (early summer and fall fertilization) were determined for annual bluegrass (Poa annua L.) and creeping bentgrass (Agrostis palustris Huds., var. Penncross) in glasshouse experiments. At the three‐leaf stage, both plant species were treated with 30, 100, 300, 1,000, 3000 or 10 000 p.p.m. (w/v) of N, P₂O₅ and K₂O equivalent to ammonium sulfate (N), calcium superphosphate (P) and potassium chloride (K). Three weeks after fertilization, the dry weight of shoots or roots was measured. Both plant species were more sensitive to N than to P or K; however, creeping bentgrass required a higher rate of N (1000 p.p.m.) for maximum shoot and root growth than did the weed (300 p.p.m., N). Shoot growth of both plant species was strongly affected by the timing of N fertilization and soil texture; their shoot responses to N increased in the order: composite soil > light clayey soil, and early summer N fertilization > fall N fertilization, and this tendency was especially marked for creeping bentgrass. These results suggest that the response of annual bluegrass to fertilizer is similar to that of creeping bentgrass; however, the two plants are different in regard to the N requirement or their relationship between response to N and application timing and/or soil texture.