A mating disruption approach using high densities of pheromone dispensers, has recently been proposed for controlling codling moth, Cydia pomonella (L.) (Lep., Tortricidae). Ecodian (R) CP dispensers, made of low-cost biodegradable material and easy to apply, were formulated with 10 mg of codlemone and placed at a rate of 1400-2000 dispensers/ha. Seasonal dispenser performance was evaluated using different methods. The release rate of new Ecodian dispensers, measured directly by solid-phase micro-extraction (SPME), was significantly higher than that of the standard monitoring lure. The release rate of field-aged dispensers decreased over time; it was comparable with that of the standard monitoring lure after 55-90 days of field exposure and significantly lower beyond. Electroantennographic (EAG) recordings showed that field-aged dispensers strongly stimulated virgin male moths' antennae. Dispensers elicited close-range approaches in wind tunnel irrespective of their age. Traps baited with aged Ecodian CP dispensers captured males throughout the season. Our results demonstrate that Ecodian dispensers achieved a good level of activity and longevity over the season. Field trials carried out from 2002 to 2004 confirmed the efficacy of Ecodian CP dispensers for codling moth control, regardless of the size of the treated area. The potential of this strategy for the control of C. pomonella is discussed.

Aims:  To investigate potential resuscitation of Listeria monocytogenes and Salmonella Typhimurium after high hydrostatic pressure treatments.

High hydrostatic pressure is regarded as possible alternative method for food preservation. One of the primary considerations for industrial applications is the ability of this method to eradicate pathogenic micro-organisms. This study subjected L. monocytogenes suspensions, in a phosphate buffer (pH 7·0) or in a citrate phosphate buffer (pH 5·6), to high hydrostatic pressure treatments relative to the following variables: pressure (200–600 MPa), treatment time (3, 10 and 20 min), temperature (4, 20 and 40°C) and the pH of the suspension medium (5·6 and 7·0). An optimal design of 40 runs was obtained using the Fedorov algorithm, and responses were studied by analysis of variance in terms of cell survival on plate count agar. Efficiency was determined by log10comparisons of the numbers of live cells before and after treatment. A statistically significant relationship was found between the four variables considered (pressure, pH, treatment time and temperature), their interactions (treatment time vs pressure, pH vs treatment time, pH vs pressure, pressure vs temperature, treatment time vs temperature) and the inactivation of L. monocytogenes. R -squared statistical analysis indicated that the linear model used accounted for more than 98·5% of the variability in the inactivation ofL. monocytogenes .

The histochemioal distribution of sorbitol dehydrogenase in normal and cryptorchid rat testis has been studied. In the normal testis sorbitol dehydrogenase is localized in the spermatids, increases during their differentiation and is maximal in those spermatids attached to the Sertoli cells (stages V–VII). In the cryptorchid testis, sorbitol dehydrogenase activity of the spermatids, similarly to that of the Sertoli cells, is completely abolished. Therefore, we conclude that sorbitol dehydrogenase activity of the Sertoli cells depends on the spermatid differentiation.

ABSTRACT Unincubated White Leghorn fertile eggs were injected with isonicotinic acid hydrazide (INH) through a hole in the shell. A control group was injected with normal saline, a second group with INH plus vitamin B6, and a third group was left unopened. INH, in the doses we used, proved to be lethal for more than 50% of the early chick embryos, and also produced important developmental alterations. Alterations produced by INH were primarily observed at the level of the neural epithe-lium, particularly at its cephalic portion. The most important ones were a degenerative and necrotic process of the neural epithelium, and a distortion of the normal anatomical relations of the cephalic structures. The embryonic mortality and developmental alterations induced by INH were prevented to a considerable extent by the concurrent injection of pyridoxine hydrochloride and INH. The preventive action of vitamin B6 suggests that toxicity of INH in the chicken embryos is due to the antivitamin-B6 action of INH. Through this mechanism INH would block, specially, the amino acid metabolism. The developing nervous system was the embryonic area most sensitive to such metabolic alterations.

In bovine and other ungulates the content of fructose is higher in fetal than in maternal blood, by as much as 100 mg or more per cent (Goodwin, 1956). That the placenta of these animals has the ability to convert glucose into fructose has been demonstrated both in vivo (Huggett, Warren & Warren, 1951) and in vitro (Hagerman & Villee, 1952). The route by which fructose is formed in the placenta either via phosphorylated intermediates or via sorbitol is unclear. It has been assumed that the fetus does not synthesize fructose (Huggett et al. 1951), and the role of fructose in fetal metabolism is quite unknown. In order to contribute to the elucidation of these problems we believed that it would be of interest to study the histochemical localization of ketose-reductase (sorbitol dehydrogenase or L-iditol:NAD oxido-reductase, E.C. 1.1.1.14) activity in the fetal and maternal tissues of the bovine placentome and other placental types. In addition, we have studied the distribution of this enzymic activity in some fetal organs (liver, kidney and lung).

SUMMARY The location of aldose and ketose reductases and of isocitric, succinic, malic and α-ketoglutaric dehydrogenases was studied by histochemical methods in the seminal vesicles of the bull, bull calf and castrated bulls. The appearance of aldose and ketose reductase activity coincides with that of significant quantities of fructose collected from the accessory glands of calves of 5·5 months of age. The enzymes of the Krebs' cycle, isocitric, succinic, malic and α-ketoglutaric dehydrogenases, could not be histochemically demonstrated in the seminal vesicles of bulls, bull calves and castrated young bulls. The factors determining the high citric acid concentrations in bull seminal vesicles are discussed.

SUMMARY The histochemical technique for the demonstration of the d-sorbitol dehydrogenase activity gave intensely positive results in the epithelium of the seminal vesicles and the glands of the ampulla of the ductus deferens of the bull. The enzymic activity was lower in the prostatic epithelium of the ductus deferens and the epididymis. The reaction was negative in the epithelium of the bulbo-urethral glands of Cowper. The enzymic activity detected is connected with the synthesis of fructose, but in organs with a low concentration of fructose, such as the prostate gland and the ductus epididymidis the presence of the enzyme may be connected with the synthesis of sorbitol, also present in the semen. In the seminal vesicles d-sorbitol dehydrogenase activity was found in the epithelium of the glandular tubules and in the material contained in those tubules. Using this technique, we have observed in the epithelium different types of cells which may correspond to different stages of a secretory cycle. The cells with greater deposits of diformazan appear to be related to the secretion of a product with enzymic activity.