Hybridization between Camelina sativa (L.) Crantz (false flax) and North American Camelina species

The potential for gene flow between Camelina sativa, a promising edible and industrial oil crop in Canada, and its wild North American relatives C. alyssum, C. microcarpa and C. rumelica subsp. rumelica, was investigated. Sequence analysis of the nuclear ribosomal internal transcribed spacer region (ITS) was used to differentiate Camelina species and/or accession‐specific nucleotide markers and identify interspecific F₁ hybrids. ITS analysis identified hybrids in progeny of C. alyssum × C. sativa, C. microcarpa accession 36010 × C. sativa and C. sativa × C. rumelica subsp. rumelica. Seed set on C. alyssum × C. sativa F₁ and F₂ progeny was similar to the parents; few seeds were produced on hybrid progeny of C. microcarpa accession 36010 × C. sativa and C. sativa × C. rumelica subsp. rumelica. The study provided evidence that should the species have sympatric distributions and overlapping flowering periods, gene flow between C. sativa and its wild North American relatives is possible and that it would most likely occur with C. alyssum given the high fertility of the F₁ hybrids recovered.     

Phospholipase A2 and postharvest peel pitting in citrus fruit

The role of phospholipase A₂ (PLA₂) activity in development of postharvest peel pitting in mature ‘Fallglo’ tangerines [Bower citrus hybrid (Citrus reticulata Blanco × C. reticulata Blanco × C. paradisi Macf.) × Temple (C. reticulata Blanco × Citrus sinensis L.)] and ‘Navel’ oranges (Citrus sinensis L. Osbeck) was investigated. Changes in RH from 30% to 90% followed by fruit waxing increased electrolyte leakage and PLA₂ activity in flavedo, and induced pitting. Treatment with an aqueous dip of aristolochic acid (AT), a specific inhibitor of secretory phospholipase A₂ (sPLA₂) activity, immediately before transfer from 30% to 90% RH storage, markedly reduced peel pitting symptoms. Five genes encoding various phospholipase As isolated from citrus (three patatin-like and two sPLA₂-like sequences) differentially accumulated in healthy areas, areas with developing lesions and necrotic lesions of disordered fruit. Other PLA₂, phospholipase C, and phospholipase D inhibitors also reduced peel pitting; however, PLA₂ inhibitors were the most effective in preventing the disorder. In addition, phospholipase inhibitors promoted fruit decay, suggesting that innate resistance is impacted by phospholipase action. Together, the results provide evidence for involvement of phospholipase activity in development of postharvest peel pitting symptoms in citrus fruit.     

Molecular breeding for resistance to black rot [<Emphasis Type="Italic">Xanthomonas campestris</Emphasis> pv. <Emphasis Type="Italic">campestris</Emphasis> (Pammel) Dowson] in <Emphasis Type="Italic">Brassicas</Emphasis>: recent advances

The Brassicas are affected by several diseases, of which black rot, Xanthomonas campestris pv. campestris (Pam.) Dowson (Xcc), is one of the most widespread and devastating worldwide. The black rot bacteria causes systemic infection in the susceptible plants and penetrate the plants through the hydathodes or wounds. Typical disease symptoms are ‘V’ shaped necrotic lesions appearing from the leaf margins with blackened veins. Periodic outbreaks of the black rot pathogen have occurred worldwide, especially in the continental regions, where high temperatures and humidity favor the incidence of disease occurrence causing huge yield loss. The challenge to control the losses in vegetable brassicas production is made more difficult by the adverse climatic changes and evolution of new pathogenic races. The development of black rot resistant hybrids/varieties is the most reliable long term practical solution for effective disease control. Identification of new resistant genetic resources, tightly linked markers with resistance loci and QTL mapping would facilitate the breeding programme for black rot resistance. Information regarding genetics of resistance and mapping of resistance genes/QTLs will accelerate the marker assisted resistance breeding in brassica crops against Xcc. In future we need to identify the race specific candidate genes for and their validation through transgenics and gene expression. Moreover, it is imperative to identify functional markers for resistance genes through identification of R gene families and their relationship with resistance expression. This comprehensive review will help the researchers working in this area to understand the dynamics of black resistance breeding and to formulate future breeding strategies.     

Neurokinin 1 receptor antagonism as a possible therapy for alcoholism

Alcohol dependence is a major public health challenge in need of new treatments. As alcoholism evolves, stress systems in the brain play an increasing role in motivating continued alcohol use and relapse. We investigated the role of the neurokinin 1 receptor (NK1R), a mediator of behavioral stress responses, in alcohol dependence and treatment. In preclinical studies, mice genetically deficient in NK1R showed a marked decrease in voluntary alcohol consumption and had an increased sensitivity to the sedative effects of alcohol. In a randomized controlled experimental study, we treated recently detoxified alcoholic inpatients with an NK1R antagonist (LY686017; n = 25) or placebo (n = 25). LY686017 suppressed spontaneous alcohol cravings, improved overall well-being, blunted cravings induced by a challenge procedure, and attenuated concomitant cortisol responses. Brain functional magnetic resonance imaging responses to affective stimuli likewise suggested beneficial LY686017 effects. Thus, as assessed by these surrogate markers of efficacy, NK1R antagonism warrants further investigation as a treatment in alcoholism.     

Abnormal sebaceous gland differentiation in 10 kittens ('sebaceous gland dysplasia') associated with generalized hypotrichosis and scaling

A rare congenital dermatosis, characterized by progressive hypotrichosis with variable scaling and crusting, occurred in 10 short-haired kittens in North America and Europe. Lesions appeared at between 4 and 12 weeks of age, commencing on the head and becoming generalized. The tail was spared in two kittens. Generalized scaling was mild to moderate, often with prominent follicular casts. Periocular, perioral, pinnal and ear canal crusting was occasionally severe. The skin was thick and wrinkled in two kittens. Histologically, the main lesion was abnormal sebaceous gland morphology. Instead of regular differentiation from basal cells to mature sebocytes, the glands were composed of a haphazard collection of undifferentiated basaloid cells, some partly vacuolated and a few containing eosinophilic globules. Mitotic figures and apoptotic cells were present in an irregularly thickened follicular isthmus. Lymphocytic mural folliculitis and mild sebaceous adenitis were rare. Orthokeratotic hyperkeratosis and follicular casts were present. Hair follicles were of normal density and were mostly in anagen, but some contained malacic hair shafts. Perforating folliculitis, leading to dermal trichogranuloma formation, occurred occasionally. Further biopsy samples taken at 2 years and at 3 and 4 years, respectively, from two kittens revealed similar but often more severe sebaceous gland lesions. Hair follicles were smaller, with many in telogen. The young age of onset suggests a genetic defect interfering with sebaceous and, possibly, follicular development. These lesions are discussed with reference to studies of mouse mutants in which genetic defects in sebaceous differentiation cause a similar phenotype of hyperkeratosis and progressive alopecia.     

Intervertebral and intravertebral ratios in Doberman pinscher dogs with cervical spondylomyelopathy

No screening method is currently available to differentiate dogs with and without cervical spondylomyelopathy. Intravertebral and intervertebral ratios are used in horses and can predict cervical vertebral malformation. Intervertebral ratios could be a useful screening method for canine cervical spondylomyelopathy. Our purpose was to compare cervical intervertebral and intravertebral ratios in normal vs. affected Doberman pinschers. Forty dogs were studied, 27 affected and 13 normal. Cervical radiographs were obtained in all dogs. The minimum intra- and intervertebral sagittal diameter ratios were established for each cervical vertebrae and disc space from C(2) to C(7) . Comparisons were made between groups and specific vertebral body and disc levels. The effect of gender, age, and method of measurement (analog or digital radiographs) was also studied. There was no difference in either the intervertebral or intravertebral ratio between normal vs. affected dogs. The ratios decreased progressively along the cervical spine, being smallest at C(6) -C(7) and C(7) , respectively. Age, gender, and method of measurement had a significant influence on both inter- and intravertebral ratios, with smaller ratios seen as dogs aged and in male dogs. Based on our results, inter- or intravertebral ratios have no value to distinguish between clinically normal Doberman pinschers and Doberman pinschers with cervical spondylomyelopathy.     

Ocular penetration of oral doxycycline in the horse

OBJECTIVE: To investigate intraocular penetration of orally administered doxycycline in the normal equine eye and to compare intraocular and serum doxycycline concentrations. Procedures Six mares were administered doxycycline at 10 mg/kg every 12 h by nasogastric tube for 5 days. Blood, aqueous, and vitreous samples were collected on days 1 and 5. All samples were assayed for doxycycline concentrations. Aqueous and vitreous samples were also assayed for protein quantitation. RESULTS: Doxycycline was rapidly absorbed after the first dose (T(max) value of 1.42 +/- 1.28 h); and elimination of doxycycline occurred slowly (median t(1/2) = 10.88 h). Doxycycline could not be detected in the aqueous on days 1 and 5, nor could it be detected in the vitreous on day 1. On day 5, the mean vitreous doxycycline concentration was 0.17 +/- 0.04 microg/mL at 2 h after drug administration. CONCLUSIONS: Repeated oral administration of doxycycline in the horse resulted in steady state serum concentrations of < 1 microg/mL; however, it did not result in appreciable concentrations of drug in the aqueous and vitreous in normal eyes.     

Comparison of carprofen and meloxicam for 72 hours following ovariohysterectomy in dogs

OBJECTIVE: To compare the peri- and post-operative (72 hours) analgesic effects of injectable and orally administered carprofen and meloxicam for ovariohysterectomy in dogs. STUDY DESIGN: Prospective, randomized clinical study. ANIMALS: Forty-three dogs undergoing elective ovariohysterectomy. MATERIALS AND METHODS: Dogs were randomly assigned to receive pre-operative carprofen, meloxicam or sterile saline by subcutaneous injection. Pre-anaesthetic medication was intramuscular acepromazine (0.02 mg kg(-1)) and methadone (0.2 mg kg(-1)). Anaesthesia was induced with either thiopentone or propofol injected to effect, and maintained with isoflurane in oxygen. Visual analogue scores (VAS) for pain and sedation were recorded at 1, 2, 3, 4 and 6 hours following tracheal extubation. Oral medication with the same treatment was continued post-operatively for 3 days, with VAS scores for pain being recorded before, and 2 hours after treatment on each day. Differences between group age, body mass, duration of general anaesthesia, time from treatment injection to tracheal extubation and time from treatment injection to first oral treatment were analysed using one-way analysis of variance and Kruskal-Wallis test. Visual analogue scores for pain and sedation were analysed using a re-randomization method. The significance level was set at p < 0.05. RESULTS: Meloxicam-treated subjects had lower mean VAS than the control group at 2 and 6 hours following tracheal extubation. Control group VAS were more varied than meloxicam scores (at 6 hours) and carprofen scores (at 3 and 6 hours). On the first post-operative day, pre- to post-treatment VAS scores decreased significantly after meloxicam. On day 3, scores in the meloxicam-treated group were significantly lower than control values after treatment. Changes in pre- to post-treatment VAS were greater in animals receiving either meloxicam or carprofen compared with those given saline. CONCLUSIONS AND CLINICAL RELEVANCE: Both carprofen and meloxicam provided satisfactory analgesia for 72 hours following ovariohysterectomy in dogs.