Uptake of beta-carotene by ovarian and uterine tissues and effects on steroidogenesis during the estrous cycle in cats.

OBJECTIVES: To determine uptake of beta-carotene by ovarian and uterine tissues and influence of dietary beta-carotene on steroidogenesis and production of uterine protein during the estrous cycle in cats. ANIMALS: 56 female cats. PROCEDURE: Cats were fed diets containing 0, 0.4, 2, or 10 mg of beta-carotene daily for 8 weeks prior to detection of estrus. At time of observed estrus, all cats were manually induced to ovulate. Blood samples were obtained at estrus and every 2 days until day 14 after ovulation. On that day, cats underment laparotomy, and the ovaries and uterus were removed. Uterine contents were flushed, and luteal and endometrial tissues were obtained. RESULTS: Concentrations of beta-carotene in plasma and luteal and endometrial tissues increased in a dose-dependent manner. Concentrations of plasma progesterone were higher between days 6 and 10 after ovulation in cats fed diets containing beta-carotene and continued to increase through day 14 after ovulation in cats fed a diet containing 10 mg of beta-carotene. Plasma concentration of estradiol-17beta also was higher between days 0 and 4 after ovulation in cats fed diets containing beta-carotene. Cats fed a diet containing 10 mg of beta-carotene had the highest plasma estradiol concentration. Total uterine protein concentration was higher in cats fed beta-carotene, compared with values for cats fed an unsupplemented diet. CONCLUSION AND CLINICAL RELEVANCE: Cats readily absorb beta-carotene. Increased concentrations of progesterone, estradiol, and uterine protein may provide more optimal ovarian function or a better uterine environment for embryonic survival and development.     

Absence of evidence of porcine circovirus infection in piglets with congenital tremors.

Porcine circovirus types 1 (PCV1) and 2 (PCV2) have been associated with congenital tremors (CTs) in piglets in the United States. In this study, central nervous system and nonneural tissues of 40 CT piglets from Spain, the United Kingdom, Ireland, and Sweden were investigated for the presence of PCV1 and PCV2 using in situ hybridization and immunohistochemical labeling on paraffin sections. The polymerase chain reaction for PCV2 was also carried out on sera from the Spanish CT cases. No evidence of circovirus nucleic acid or antigen was found in any CT piglet. Although these results do not support the hypothesis that PCV1 or PCV2 are linked to porcine CT, they cannot disprove it.     

Pathological changes following implantation of intramammary devices (IMD) and immunological mediator release by cells on recovered IMDs

Implantation of abraded polyethylene intramammary devices (IMD) for six months in the mammary glands of cows resulted in macroscopic and microscopic pathological changes in udder tissue. These changes were characterised by hyperplasia and metaplasia of the epithelial cells and hypertrophy of the subepithelial connective tissue examined by light and electron microscopy (EM). Quarters containing IMDs also had increased numbers of neutrophils and macrophages in the subepithelial stroma compared with control quarters. IMDs recovered six months after implantation were shown by transmission and scanning EM to be covered with plaque and cells. These cells were mainly macrophages, although other leucocytes were also present. In vitro culture of recovered IMDs in the presence of lipopolysaccharide resulted in the release of neutrophil chemotactic factor, or factors, and interleukin-1. Some quarters with IMDs also had concurrent infections at the time of slaughter. In these cases both the pathological changes seen in the tissues and the release of soluble mediators following in vitro culture of the IMDs were significantly increased compared with sterile quarters containing IMD.     

橄榄星室木虱的生物学特性及防治

作者记述一为害橄榄的重要害虫橄榄星家木虱的生物学特性，种群数量动态及其天敌种类资源。该虫在福州地区１年发生７－９代，没有明显的越冬现象。翌年２月下旬，３月上旬产卵于嫩芽上，３月上旬出现若虫，第１代成始见于３月下旬，世代重叠。橄榄星家木虱田间种数数量消长与橄榄抽梢期有极其密切的伴随关系，在纪树上本年有５年虫口高峰期，在老树上全年只有３个高峰期。在实验室２３．０－２５．０℃的平均温度下，卵期４．１－４     

Comparative fate in soil of the enantiomers of triadimenol when applied individually to barley seed

The systemic fungicide triadimenol is a mixture of four enantiomers which have different biological activities. Dissipation and metabolism of the individual enantiomers in soil were investigated after seed treatment. Forty-nine days after 1R2S and 1S2S treatments, more of the radioactivity (87% for both) had dissipated from the seeds into the 0–10 cm soil layer than after the 1S2R (76%) and 1R2R (73%) treatments. After 1R2S treatment 56% of the radioactivity extracted from soil was accounted for as the parent isomer and 44% as its 1R2R epimer. After 1S2R treatment 76% of the radioactivity was in the parent form and 24% was converted to the 1S2S (17%) and 1R2R (7%) isomers.     

Cytochemical demonstration of the effects of the acylureas flufenoxuron and diflubenzuron on the incorporation of chitin into insect cuticle

Flufenoxuron (“Cascade”) is a novel acylurea with acaricidal and insecticidal properties. It acts in a similar manner to diflubenzuron (DFB) by impairing chitin incorporation into insect cuticle. Chitin can be localised cytochemically using the lectin, wheat germ agglutinin (WGA), which binds specifically to N-acetylglucosamine-containing polymers. WGA adsorbed to monodisperse colloidal gold (WGA-gold) was used as an electron-dense marker for localising chitin in the cuticle of sixth-instar Spodoptera littoralis. In the cuticle of control insects, the deposition zone and endocuticle were heavily labelled. In flufenoxuron- and DFB-treated insects, only the endocuticle (formed before treatment) was labelled, the deposition zone being devoid of label. These results show that flufenoxuron and DFB act in similar manner in reducing chitin incorporation in the cuticle of S. littoralis.     

Energy expenditure of Angora bucks in peak breeding season estimated with the doubly-labeled water technique

We used the doubly-labeled water (DLW; 2H2(18)O) method to compare total energy expenditure (TEE) of Angora bucks and wethers over a 15-d period during peak breeding season. Four bucks (57+/-3 kg) and four wethers (45+/-2 kg) were fitted with marking harnesses to measure sexual activity and allocated pairwise to one of four breeding groups (n = 30 does/group). Subjects were infused i.v. with 2H2(18O) that provided 200 mg 2H2O and 250 mg H2(18)O/kg BW. Blood samples were collected over a 15-d period, with 3- to 4-d intervals for isotope enrichment measurements. Total DLW-derived energy expenditure (TEE) was similar (P = .55) between bucks and wethers (2,578 vs 2,365; SE 239 kcal/d). Large variation was observed among wethers in TEE, courtship, and attempted mountings. Total energy expended corrected for that in mohair production (CTEE) tended (P = .09) to be greater in sexually active wethers (133+/-8 kcal ME/[kg BW.75 x d(-1)]; n = 3) than in bucks (110+/-7 kcal ME/[kg BW.75 x d(-1)]; n = 4). Energy expended on activity (EEa) by these wethers was highly correlated (r = .98) with the number of does marked, which may explain high variability among wethers in EEa. Bucks marked more does (18+/-1; P < .05) than wethers (8+/-3), but a weak relationship (r = .36) existed between number of does marked and EEa, suggesting individuality in style and persistence while courting. In Angora bucks, CTEE during the breeding season was 9% greater than the maintenance energy requirement. In conclusion, breeding activities in single-buck breeding groups did not markedly increase energy requirements of Angora bucks.     

Detection of cymbidium mosaic potexvirus and odontoglossum ringspot tobamovirus using immuno-capillary zone electrophoresis

ABSTRACT Immuno-capillary zone electrophoresis (I-CZE) is a technique that combines the specificity afforded by serological assays with the sensitivity, rapidity, and automation in detection provided by capillary zone electrophoresis. Cymbidium mosaic potexvirus (CymMV) and odontoglossum ringspot tobamovirus (ORSV) were detected in their purified forms as well as in the crude saps of infected Nicotiana benthamiana leaves and Oncidium orchid flowers. The two orchid virus-antibody complexes were resolved via the combined actions of electrophoretic migration and electro-osmotic flow along a buffer-filled, uncoated fused-silica capillary. The I-CZE fractions collected from both CymMV- and ORSV-antibody complex peaks, as well as the RNA purified from them, retained their infectivity upon inoculation onto Chenopodium quinoa. I-CZE assays were able to detect as little as 10 fg each of both CymMV and ORSV in their purified forms as well as in the crude saps of infected N. benthamiana and Oncidium orchid. As multiple samples can be analyzed rapidly, I-CZE offers an ideal diagnostic technique for routine mass-indexing programs such as virus-free certification, breeding for virus-resistant cultivars, plant quarantine, and germ plasm screening. This is the first report of the application of I-CZE for the detection of plant viruses.     

Signal Transduction in Resistance to Plant Viruses

Salicylic acid is part of a signal transduction pathway that induces resistance to viruses, bacteria and fungi. In tobacco and Arabidopsis the defensive signal transduction pathway branches downstream of salicylic acid. One branch induces PR-1 proteins and resistance to bacteria and fungi, while the other triggers induction of resistance to RNA and DNA viruses. This virus-specific branch can be activated using antimycin A and cyanide, or inhibited with salicylhydroxamic acid, suggesting a role for alternative oxidase in resistance to viruses. The virus-specific defensive pathway activates multiple resistance mechanisms. In tobacco, salicylic acid induces resistance to systemic movement of cucumber mosaic virus but has no effect on its replication or cell-to-cell movement. However, in the case of tobacco mosaic virus in tobacco, salicylic acid appears to induce interference with the synthesis of viral RNA.