bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Sensitivities of Various Erythrocytes in a Haemagglutination Assay for the Detection of Psittacine Beak and Feather Disease Virus
Authors: Sanada N. , Sanada Y. 
Published: March 2003

SummaryThe erythrocytes of various species were tested in psittacine beak and feather disease (PBFD) virus haemagglutination (HA) and haemagglutination inhibition assays to determine which are suitable for use in these assays. HA activity was observed for erythrocytes of the salmon‐crested cockatoo, the sulphur‐crested cockatoo, the umbrella cockatoo, the goffin's cockatoo and the cockatiel, with differences amongst individuals within species, but not for erythrocytes of humans, the pig, the guinea pig, the chicken, the goose, the rose‐ringed parakeet or the budgerigar. Anti‐PBFD virus rabbit sera inhibited the virus‐induced agglutination of erythrocytes, confirming the specificity of HA activity. This suggests that selection of suitable psittacine species as well as suitable individuals within a species is necessary when obtaining erythrocytes for the PBFD virus HA assay.
Bacterial Colonization and Invasion in Pigs Experimentally Exposed to Streptococcus suis Serotype 2 in Aerosol
Authors: MADSEN L. W. , BAK H. , NIELSEN B. , JENSEN H. E. , AALBÆK B. , RIISING H. J. 
Published: March 2003

A recently developed porcine model for aerogenous infection with Streptococcus suis serotype 2 was applied in a study of the phases of bacterial colonization and initial invasion. Eighteen pigs were exposed to aerosolized S. suis serotype 2 after pre‐exposure to mild acetic acid in aerosol. The animals were killed consecutively within the first six days after challenge. After death, all animals were necropsied and examined by bacteriology, histopathology, and immunohistochemistry.Systemic infection was established in four out of 18 animals exposed to S. suis serotype 2. All systemically infected animals developed clinical signs and lesions typical of the infection. In four additional animals, subclinical infection was demonstrated by re‐isolation of S. suis from the palatine tonsil. However, in all 18 challenged animals, immunohistochemistry demonstrated S. suis serotype 2 antigen in the palatine and/or nasopharyngeal tonsils. In all four systemically infected animals, S. suis serotype 2 antigen was also found in the mandibular lymph node. These observations point towards the tonsils as possible portals of entry for S. suis serotype 2 with subsequent lymphogenous spread. Thus, the present findings parallel the proposed pathogenesis for S. suis serotype 1 infection in pigs.
An Unusual Outbreak of Malignant Catarrhal Fever in a Beef Herd in Israel
Authors: Brenner J. , Perl S. , Lahav D. , Garazi S. , Oved Z. , Shlosberg A. , David D. 
Published: March 2003

SummaryMalignant catarrhal fever (MCF, corrizza contagiosa) is an invariably fatal communicable disease in cattle, whose causative agent is the ovine herpes virus‐2, or the alcelaphine herpes virus‐1. In one feed‐lot family farm, 34 calves out of 100 became ill at the rate of one to four calves per week, and all of them subsequently died over a period of 4 months. Most of the initial cases were manifested clinically as the head and eye form, but most of the entire clinical spectrum of forms (the respiratory, intestinal and nervous forms) characteristic for MCF were observed as this epidemic progressed. Very few calves died without showing any specific signs of MCF. Pathological examinations revealed characteristic obliterative arteriovasculitis in the brain of calves with nervous signs, typical of MCF. Polymerase chain reaction (PCR) testing revealed 100% homology between the 238 bp hemi‐nested PCR fragment and the ovine herpes virus‐2 sequences.Based on the clinical signs, epidemiological data, pathological, and histopathological findings, and the PCR results, it was concluded that MCF occurred on the farm. The fact that sheep and goats were housed in close proximity on the same farm reinforced this diagnosis.
Optimization of a Culture Technique for the Isolation of Listeria monocytogenes from Faecal Samples
Authors: Erdogan H. M. , Cripps P. J. , Morgan K. L. 
Published: March 2003

SummaryA culture technique employing cold enrichment at 4°C followed by selective enrichment and plating at higher temperatures (30°C) was used to isolate Listeria monocytogenes from faecal samples. The samples were held at 4°C for 15 weeks and cultured weekly to assess the sensitivity of the culture after cold storage for different lengths of time. No media, Listeria selective enrichment broth (LSEB), nutrient broth (NB) and saline were used as cold storage medium. Cold storage increased the frequency of Listeria positive samples. The sensitivity of the culture for Listeria spp. and L. monocytogenes was 72 and 94%, and 56 and 61% after third and seventh week of cold storage, respectively. When the results of third and seventh week of cold storage were combined, the sensitivity was 100% for Listeria spp. and 94% for L. monocytogenes. LSEB and NB as storage medium increased Listeria positive samples after the first week of cold storage but did not maintain the increase thereafter while saline had an adverse effect on the growth of the bacteria. However, samples held in no media in a pilot study involving monthly sampling of a herd revealed better results. Detection limit of the culture media was also investigated. The lowest concentration detected by culture media was 3.17 organisms/ml. This was seven organisms/g for known Listeria positive sample. The faecal samples spiked with 10‐fold dilutions of L. monocytogenes and held at 4°C revealed that the sample spiked with 3.17 × 10−1 cfu/ml organisms resulted in growth after the second week of cold storage. The results suggest that the culture technique employing cold enrichment followed by selective enrichment and plating is more sensitive, the storage of faecal samples in no media when compared with the samples in storage medium, LSEB, NB and saline, during cold enrichment is a better application and culture of faeces, immediately after collection, at third and seventh week of cold enrichment produce more satisfactory results.
The frequency of Candida parapsilosis in onychomycosis. An epidemiological survey in Israel
Authors: Segal R. , Kimchi A. , Kritzman A. , Inbar R. , Segal And Z. 
Published: March 2003

Summary Candida albicans is regarded as the major pathogen in yeast‐induced onychomycosis. Based on our impression of an increasing prevalence of Candida parapsilosis in this disease, we examined the data of two mycology laboratories in the same geographic location, from 1994 to 1996 in one (centre A) and for 1995 (6 months) in the other (centre B). A total of 954 and 230 toenails and 621 and 190 fingernails, respectively, underwent KOH microscopy and culture studies in each centre. Positive findings were noted in 45 and 65% of the toenails and 44 and 72% of the fingernails, respectively. In the toenails, Candida spp. were found in 22 and 15%, respectively, and in the fingernails, in 77 and 63%, respectively. The most frequent Candida species was C. parapsilosis (39.5% in toenails, 36.7% in fingernails), followed by C. albicans (19.5% in toenails, and 34.4% in fingernails). These results demonstrate a higher frequency of isolation of C. parapsilosis compared with C. albicans in onychomycosis. This might have important therapeutic implications.
Morphological characterization of modified flower morphology of three novel alloplasmic male sterile carrot sources
Authors: Linke B. , Nothnagel T. , Börner T. 
Published: March 2003

AbstractThree novel sources of cytoplasmic male sterility (CMS) in carrot are characterized by altered flower phenotypes. Flowers were classified into subtypes, according to stamen (and petal) modification. Flower anatomy was investigated by light microscopy to describe organ modification and to specify the timing when morphology begins to deviate. Early stages of floral development were defined in fertile male flowers of the cultivated carrot according to model plants such as Antirrhinum and Arabidopsis and compared with corresponding stages of the novel cytoplasmic male‐sterile flower types. Early organogenesis was identical in the different CMS types and comparable to corresponding stages of unmodified flowers. The morphology of stamens, and in some cases petals, became different in CMS flowers during early organ differentiation. For each CMS type, the cytoplasm appears to influence organogenesis in a specific way. Although homoeosis is usually considered to be controlled exclusively by specific nuclear genes, a role of cytoplasmic factors is suggested
Characterization and inheritance of partial resistance to downy mildew, Peronospora parasitica, in breeding material of broccoli, Brassica oleracea convar. botrytis var. italica
Authors: Jensen B.D. , Værbak S. , Munk L. , Andersen S. B. 
Published: March 2003

AbstractTwenty doubled haploid broccoli lines from breeding material were evaluated for resistance to Peronospora parasitica at the seedling stage. All lines supported sporulation of the pathogen but to varying extents and intensities. Partial resistance of the more resistant lines,‘br8’and ‘br9′, reduced conidia production on cotyledons by 50‐70% compared with the most susceptible lines. Inoculation of the two most resistant lines with 13 isolates of different geographical origins revealed that ‘br9′, showed a rather uniform level of resistance to all isolates while ‘br8’showed some isolate specificity Partial resistance was evaluated in six of the broccoli lines in a half diallel set of crosses. Disease assessment of seedlings showed that additive genetic effects explained 45.8% and 31.8% of the total variation of sporulation score and conidia production, respectively This suggests that recurrent selection for partial resistance to P. parasitica in early generation in breds or in populations of broccoli will be efficient to obtain cotyledon resistance.
Changes in genetic diversity during seven cycles of recurrent selection for grainyield in oat, Avena sativa L.
Authors: Koeyer D. L. De , Phillips R. L. , Stuthman D. D. 
Published: March 2003

AbstractVariability for desirable alleles within elite breeding populations is a requirement for long‐term genetic improvement. Changes in genetic diversity were evaluated in a recurrent selection programme for enhanced grain yield in oat, Avena sativa L., using coefficient of parentage (rp) and restriction fragment length polymorphism (RFLP) based genetic similarity (S) estimates. Both rp and s increased during seven cycles of recurrent selection, indicating a reduction in the level of genetic diversity within the population. The relationship between genetic diversity and agronomic performance was also examined. Genetic similarity measures were poor predictors of the near‐homozygous progeny performance and general and specific combining ability effects for three agronomic traits in the recurrent selection programme. In addition, there was no apparent trend for preferential selection of progeny from either more similar or more diverse parents within a given cycle of selection. The overall reduction in genetic diversity in this population has not affected selection response for grain yield. Variability remaining at important loci or de novo variation are possible explanations for the continued selection progress.
Male sterility in alloplasmic Brassica rapa L. carrying Eruca sativa cytoplasm
Authors: Matsuzawa Y. , Mekiyanon S. , Kaneko Y. , Bang S. W. , Wakui K. , Takahata Y. 
Published: March 2003

AbstractFor the development of a new cytoplasmic male sterility (CMS) system in Brassica rapa (2n= 20, AA), intergeneric hybridization was performed in Eruca sativa (2n= 22, EE)×B. rapa. The original amphihaploid F1 plant (2n= 21, EA) generated via embryo rescue produced a sesquidiploid F1 plant (2n= 31, EAA), from which the alloplasmic F3 plants were generated. In F3, some progenies with malformed anthers were maintained as male‐sterile lines up to the F5 generation. In the F6 and F7 generations, the alloplasmic male‐sterile plants were bred by backcrossing to several B. rapa genotypes and were then classified into the three distinctive types: petaloid, antherless and brown anther, in addition to three intermediate types between them. By southern blot analysis, each plant of the petaloid and antherless types was shown to carry the cytoplasm genome of E. sativa. These male‐sterile plants produced as many viable seeds as the corresponding male‐fertile plants, although their nectary gland development was minimal. Consequently, CMS lines of the petaloid and antherless types with enhanced seed fertility and nectary gland development could provide promising plant materials for F1 seed production in B. rapa.
Changes in expression of HMW glutenins of wheat (Triticum aestivum L.) induced by nitrosoethylurea
Authors: Š Vec M. , Gregová E. , Miklovičová M. , Kraic J. 
Published: March 2003

AbstractThe application of a chemical mutagen, N‐nitroso‐N‐ethylurea, to the grains of wheat (Triticum aestivum L.) cv. ‘Viginta’, provided a mutant line,‘NT‐10′, with an altered composition of high molecular weight (HMW) glutenin subunits. The qualitative mutation was detected in the Glu‐B1 locus by electrophoretic analyses of glutenins. Instead of the HMW glutenin subunits 7 + 9 present in the original genotype, a separate HMW subunit 6 was expressed in the mutant line. The other glutenin and gliadin proteins of the mutant line remained unchanged. The mutant line is also characterized by several changes in morphological and physiological characters—stronger stem, wider leaf, bigger spike and higher grain hardness. This is the first communication of the possibility of changing the composition of high molecular weight subunits of wheat glutenin by means of mutagenesis.
Identification of stable maintainer and fertility restorer lines for ‘Polima’ CMS in Brassica campestris
Authors: Verma J. K. , Sodhi Y. S. , Mukhopadhyay A. , Arumugam N. , Gupta V. , Pental D. , Pradhan A. K. 
Published: March 2003

Abstract‘Polima’ cytoplasmic male sterility (CMS) was transferred from ‘Polima’ Brassica napus ‘ISN 706’to five different cultivars of Brassica campestris (‘Pusa kalyani’, ‘Pant toria’, ‘Candle’, ‘Tobin’ and ‘ATC 94211′) by repeated backcrossing. It was observed that, while ‘Polima’ CMS manifested complete and stable male sterility in the nuclear backgrounds of ‘Pusa kalyani’, ‘Pant toria’, and ‘Tobin’, the cultivars ‘Candle’ and ‘ATC 94211’possessed the restorer gene for this CMS in the heterozygous condition. An analysis of F1 and F2 generations of ‘Polima’‘Pusa kalyani’×‘Candle’ and ‘Polima’‘Pusa kalyani’×‘ATC 94211’ revealed that restoration is controlled by a single dominant gene. Identification of stable maintainers and restorers of ‘Polima’ CMS could facilitate the development of hybrid varieties in B. campestris.
Concentration effects of dicamba on shoot regeneration in wheat
Authors: Bahieldin A. , Dyer W. E. , Qu R. 
Published: March 2003

AbstractShoot formation and regeneration rates of calli derived from immature embryos of three spring wheat varieties were investigated to evaluate the influence on wheat regeneration of different concentrations of dicamba (0.5, 0.1 and 0.02 mg/l) in the regeneration medium. It was found that dicamba concentrations much lower (0.02 and 0.1 mg/l) than the levels reported previously (1 and 0.5 mg/l) induced significantly more shoots per callus in all three varieties, while the enhancement in regeneration rate was variety dependent. Overall, a dicamba concentration of 0.02 mg/l was more favourable for wheat regeneration.
Microsatellite polymorphism in Pisum sativum
Authors: Burstin J. , Deniot G. , Potier J. , Weinachter C. , Aubert G. , Barranger A. 
Published: March 2003

Abstract Pisum sativum sequences were retrieved from Genbank/EMBL databases and searched for all possible dinucleotide and trinucleotide tandem repeats. One‐hundred and seventy‐one simple sequence repeats (SSRs) were found among 663 sequences. The different dinucleotide or trinucleotide motifs occurred at varying frequencies. CT/AG was the most frequent dinucleotide, and TCT/AGA the most frequent trinucleotide. Forty‐three microsatellite markers were generated from these sequences and used to assess the genetic variability among 12 pea genotypes. Thirty‐one were polymorphic among the genotypes and the average number of variants per marker was 3.6 when considering only polymorphic markers. Overall, the number of variants for a given SSR marker was correlated with the length of the SSR but some 12‐bp long SSRs showed the same degree of polymorphism as longer ones. The groupings resulting from the SSR genotyping among the 12 genotypes gave an interesting insight into the possible origin of one recent cultivar. Database‐derived SSR markers are highly variable. They can provide useful information on the genetic diversity among P. sativum cultivated types.
Detection of chromosomes carrying genes for seed dormancy of wheat using the backcross reciprocal monosomic method
Authors: Miura H. , Sato N. , Kato K. , Amano Y. , McIntosh R. A. 
Published: March 2003

AbstractPreharvest sprouting (PHS) in wheat represents a major constraint to the production of high‐quality grain. Genetic variation for tolerance to PHS is associated with seed dormancy. The present study was initiated to detect homologous chromosome variation associated with seed dormancy genes in a PHS tolerant cultivar ‘Zenkojikomugi’ (Zen) and ‘Chinese Spring’ (CS) using the backcross reciprocal monosomic method. The most striking effect on variation in seed dormancy was associated with chromosome 3A, and followed by group 4 chromosomes. These chromosomes of Zen increased dormancy compared with the respective CS homologues. Chromosomes 2D and 7D of Zen, and 6A of CS seemed to contribute smaller positive effects on dormancy. Chromosomes 2A of CS and Zen, as well as 3B, were equally effective in enhancing dormancy. The chromosome 3 A factors were independent of the grain‐colour gene R‐A1 because Zen was found to carry the white‐grained R‐A1a allele, which was identical to that of CS, and there was no difference in dormancy between the reciprocal F1 seeds.
A melon genotype with superior competence for regeneration and transformation
Authors: Galperin M. , Patlis L. , Ovadia A. , Wolf D. , Zelcer A. , Kenigsbuch D. 
Published: March 2003

AbstractTransformation efficiency of melon is low and is still regarded as a challenge. In this paper, the regeneration and transformation response of ‘BU‐21/3′, a newly characterized melon breeding line, is described. The line seems to be superior in this regard to previously evaluated genotypes. Agrobacterium‐mediated delivery of the GUS or GFP reporter genes into cotyledon explants was used to evaluate efficiency of transient and stable transformation. Good transient expression was observed, and stable transformation frequencies of 0.4‐1.5 transgenic shoots per explant were obtained. Transgenic plantlets were transferred to a contained greenhouse as early as 8‐10 weeks after transformation. Transgenic plants are fertile and exhibit a true‐to‐type phenotype. The ‘BU‐21/3’ line may become a useful tool for the facilitation of transgenic breeding in melon.
Vitamin A and β‐Carotene Levels in Plasma, Corpus Luteum and Follicular Fluid of Cyclic and Pregnant Cattle
Authors: Haliloglu S , Baspinar N , Serpek B , Erdem H , Bulut Z 
Published: March 2003

ContentsThis study was carried out to examine the relationship between the corpus luteum (CL) weight, CL and follicle diameters and progesterone, β‐carotene and vitamin A levels in reproductive organs of cattle obtained from the slaughterhouse. The β‐carotene and vitamin A levels were determined in plasma, CL and follicular fluid (FF) using a spectrophotometric method at different stages of the oestrous cycle (n=40) and at 3–6 months of pregnancy (n=10). The diameters of the CL and follicle were measured using ultrasonography. Plasma progesterone concentrations were determined by an enzyme immunoassay method. The vitamin A levels of the plasma, CL and FF were not related to each other. The highest plasma vitamin A levels were observed in the proestrus and oestrus, at which periods follicular activity dominates. The vitamin A levels in the CL and FF were negatively related to the weight and diameter of the CL and the diameter of follicle, respectively. In contrast to vitamin A, β‐carotene concentrations of plasma, CL and FF were significantly correlated with each other. The highest β‐carotene levels in the plasma, CL and FF were found during pregnancy when there is maximal luteal function, and the β‐carotene level of the CL was significantly correlated with the weight and diameter of CL. Furthermore, the intrafollicular β‐carotene level was negatively correlated with the follicle diameter. There was a positive correlation between plasma progesterone level and the weight and diameter of the CL, but a negative correlation between plasma progesterone level and follicle diameter. Moreover, plasma, FF and CL β‐carotene levels were positively correlated with plasma progesterone levels. This study revealed that β‐carotene levels in the plasma, CL and FF were influenced by the stage of the oestrous cycle or the pregnancy and were related to bovine luteal function without depending on vitamin A.
Function of the Cumulus Oophorus Before and During Mammalian Fertilization
Authors: Van Soom A , Tanghe S , De Pauw I , Maes D , De Kruif A 
Published: March 2003

ContentsFertilization encompasses a series of different steps which have to be performed in a well‐orchestrated way to create a new individual. They include sperm capacitation, sperm binding and penetration of the zona pellucida, traversing the perivitelline space, binding and fusion with the oolemma, activation of the oocyte and decondensation of the sperm head to form the male pronucleus. In most mammalian species, cumulus cells surround the oocyte at the time of fertilization. Removal of the cumulus oophorus at this point of time often leads to a drop in fertilization rates. It is not yet known how cumulus cells interact with the oocyte or with spermatozoa to promote fertilization. There are different possibilities:

cumulus cells cause mechanical entrapment of spermatozoa and guide hyperactivated spermatozoa towards the oocyte, while preventing abnormal spermatozoa to enter the cumulus matrix;
cumulus cells create a micro‐environment for the spermatozoa which favours their capacitation and penetration into the oocyte;
cumulus cells prevent changes in the oocyte which are unfavourable for normal fertilization; these changes can be located in the zona pellucida or in the cytoplasm.

In this review, studies in several species are listed to prove the importance of these three cumulus cell functions and the current lines of research are highlighted. Moreover, different ways to improve in vitro fertilization of bovine cumulus‐denuded oocytes are discussed.