bluuebunny/crossref_metadata_2025 huggingface dataset:
Genotypic variation for drought tolerance in Vicia faba
Authors: Link W. , Abdelmula A. A. , Kittlitz E. Von , Bruns S. , Riemer H. , Stelling D.
Published: March 2003

Instability of yield in faba bean is partly caused by drought susceptibility. Four sets with 10‐19 faba bean genotypes each were evaluated in multilocal field trials between 1992 and 1996. Stress occurred as natural drought in one experiment and as artificial terminal drought in three experiments. Artificial drought was induced by rain shelters; the control treatment was irrigated. Tolerance was assessed as the ratio of yield under drought (Yd) to well‐watered yield (Yw). Highly significant variances between genotypes occurred; heritability of tolerance was 0.51 < h2 <0.88. Exotic (North African. Latin American) genotypes were more tolerant than adapted material. Correlations between Yw and Yd were 0.77** < r <0.97**, and variance of Yd was less than one‐third of the variance of Yw. Drought tolerance was negatively correlated with Yd (‐0.41 < r < ‐0.22). Relative reduction of plant height due to drought was a promising trait to improve drought tolerance indirectly in two sets. The prospects of improving Yd are good: heritability was 0.68 < h2 < 0.86. Genetic improvement of drought tolerance also seems feasible. A specific cross was proposed to create improved material.
Molecular and agronomic characterization of wheat‐Agropyron intermedium recombinant chromosomes
Authors: Khan I. A.
Published: March 2003

Thirty‐six wheat‐Agropyron intermedium (host) Beauv. [Syn. Trichopyrum intermedium (host) A. Love, Elytrigia intermedia (host) Nevski, Thinopyrum intermedium (host) Barkworth and Dewey] 7A/7Ai‐1 recombinant chromosomes were characterized using DNA markers. Analysis of recombinant chromosomes using 15 restriction fragment length polymorphism probes identified the homoeologous crossover products that had varying length of A. intermedium chromatin introgressed onto chromosome 7A of common wheat. The linear order of the probe loci was established along the lengths of the chromosomes. The short arm recombinants that had A. intermedium chromatin distal to the locus Xpsr108 and proximal to the locus Xpsr119 were resistant to wheat stem rust, indicating that the rust resistance gene (Sr44) was located on the distal part of chromosome arm 4Ai‐1s. The barley yellow dwarf virus (BYDV) resistance gene reported to be present on the long arm of chromosome 7Ai‐1 was found to be ineffective against the BYDV serotype used in the present study.
Dicamba and growth condition effects on doubled haploid production in durum wheat crossed with maize
Authors: Knox R. E. , Clarke J. M. , DePauw R. M.
Published: March 2003

Doubled haploid plants are useful in genetic studies and plant breeding, but a consistent and satisfactory frequency of production has been difficult to achieve in durum wheat. Triticum turgidum L., using the maize pollen method. The objective of this study was to develop an objective method of producing doubled haploids in durum wheat. Plant growing and handling conditions, aspects of hormone treatments, wheat genotype and pollen source were considered. The number of caryopses, embryos, haploids, doubled plants and doubled plants that set seed were measured. Although growth conditions, pollen source, method of handling plants and wheat genotype are important considerations, the type of hormone was found to be most significant in the production of doubled haploid plants. When 50mg/l dicamba was substituted for 100 mg/l 2,4‐D the number of doubled haploids per spike increased from 0.2 for the best 2,4‐D treatment to 1.3 for the dicamba treatment. This increased frequency was largely attributed to an increase in the number of caryopses generated for each spike emasculated and from an increased frequency of germination of embryos to haploid plantlets. The best production of caryopses was 0.41 caryopses per florest with 2,4‐D. The best production of haploids per 100 florets was 12 with dicamba and 1.65 with 2,4‐D. The frequency of one doubled haploid per emasculated spike through the use of dicamba is a practical level for generating populations for genetic studies.
Heritability of early blight resistance in a Lycopersicon esculentum×Lycopersicon hirsutum cross estimated by correlation between parent and progeny
Authors: Foolad M. R. , Lin G. Y.
Published: March 2003

Sixteen‐hundred BC1 plants of a cross between an early blight (EB) susceptible tomato (Lycopersicon esculentum Mill.) breeding line (‘NC84173’ maternal and recurrent parent) and a resistant accession (‘PI126445’) of the tomato wild species Lycopersicon hirsutum Humb. and Bonpl. were grown in a field in 1998. This population was segregating (among other traits) for growth habit, self‐incompatibility and earliness in maturity. To eliminate confounding effects of these factors on disease evaluation and h2 estimation, plants that were self‐incompatible, indeterminate and/or late‐maturing were eliminated. The remaining plants (146), which were self‐compatible and determinate (sp./sp.) in growth habit, with early‐ to mid‐season maturity, were evaluated for EB resistance and self‐pollinated to produce BC1S1 seed. The 146 BC1S1 progeny families, consisting of 30 plants per family, were grown in a replicated field trial in 1999 and evaluated for EB resistance and plant maturity. For each of the 146 BC1 plants and corresponding BC1 families, the area under the disease progress curve (AUDPC) and final disease severity (final percentage defoliation) were determined and used to measure disease resistance. The distributions of the AUDPC and final percentage defoliation values in the BC1 and BC1S1 generations indicated that resistance from ‘PI126445’ was quantitative in nature. Estimates of h2 for EB resistance, computed by correlation between BC1S1 progeny family means and BC1 individual plant values, ranged from 0.69 to 0.70, indicating that EB resistance of ‘P1126445’ was heritable. Across BC1S1 families, a small, but significant, negative correlation (r = ‐0.26, P < 0.01) was observed between disease resistance and earliness in maturity. However, several BC1S1 families were identified with considerable EB resistance and reasonably early maturity. These families should be useful for the development of commercially acceptable EB‐resistant tomato lines.
Adaptation and ecological differentiation in wheat with special reference to geographical variation of growth habit and Vrn genotype
Authors: Iwaki K. , Haruna S. , Niwa T. , Kato K.
Published: March 2003

Geographical variation of growth habit was studied for 749 landraces from various parts of the world, with special reference to their adaptation and ecogeographical differentiation. The total frequency of spring‐type landraces was 49.9%, and varied between localities. Spring‐type landraces were frequent in two distinct areas where the average January temperature was either below ‐7°C or above 4°C, with winter‐type landraces in areas from ‐7°C to 4°C. These results indicated that geographical variation of growth habit is closely related to the degree of winter coldness. An analysis of the Vrn genotype for 216 spring‐type landraces demonstrated the uneven distribution of four Vrn genes, with Vrn4 being the least frequent. The adaptive Vrn genotype was different between localities. Genotypes carrying Vrn‐A1 and additional Vrn gene(s) were frequent in two distinct areas where the average January temperature was either below ‐7°C or over 10°C, while genotypes with any of three Vrn genes, except Vrn‐A1, adapted to areas with temperatures from 4°C to 10°C. Therefore, it was concluded that the adaptability of wheat landraces differed depending on their growth habit and Vrn genotype, and that ecotypes with different Vrn genotypes were allopatrically distributed as a result of adaptation to different winter temperature. However, the differential distribution of Vrn‐B1, Vrn‐D1 and Vrn4 could not be explained by their adaptability, and might reflect the polyphyletic origin of common wheat.
Multivariate analysis of traits determining adaptation in cultivated barley
Authors: Karsai I. , Mészáros K. , Láng L. , Hayes P. M. , Bedö Z.
Published: March 2003

Thirty‐nine barley varieties of different origin, representing different growth types, were included in a series of experiments aimed at analysing the variability in vernalization response, photoperiod sensitivity and earliness per se and establishing the types of ecoclimatic adaptability using multivariate analysis. In the case of spring barley varieties there was no correlation between any of the three traits. For winter barleys, a negative correlation was found between photoperiod sensitivity and vernalization response and between photoperiod sensitivity and earliness per se. Vernalization response and earliness per se showed a positive correlation. Among the winter barley varieties large variations were apparent in photoperiod sensitivity, vernalization response and earliness per se, which resulted in a tremendous variation in flowering patterns and frost tolerance. Between the spring barley varieties only wider variations in photoperiod sensitivity were detected. Based on the cluster analysis, the 39 varieties could be separated into seven groups. The spring barley varieties were placed in two groups, and the winter barleys in five groups representing different adaptational types. Among these five groups two represented the two opposing extreme combinations of photoperiod sensitivity and vernalization response. The combination of large photoperiod sensitivity and no vernalization response resulted in better frost tolerance than did the combination of photoperiod insensitivity and large vernalization response.
Genome‐specific markers of tetraploid wheats and their putative diploid progenitor species
Authors: Khlestkina E. K. , Salina E. A.
Published: March 2003

The objective of this study was to isolate genome‐specific markers from the genomes of tetraploid wheats and the putative donor diploid species on the basis of random amplified polymorphic DNA analysis followed by cross‐hybridization. Twenty different Triticum and Aegilops species and accessions were analysed by polymerase chain reaction (PCR) using 30 random primers. The polymorphic PCR fragments were then isolated, labelled and used in cross‐hybridization screenings. The hybridization results established that one marker was specific to the Ae. speltoides S genome, two to the A genome, one to the B genome and five to the G genomes of polyploid species (and to the genomes of the corresponding progenitor species). Four markers were identified that were specific to both the B and G genomes. Analysis of the Triticum and Aegilops species and accessions supported the notion that Ae. speltoides is more closely related to the B and G genomes of polyploid wheat species than were other members of the Sitopsis section. The data also indicated that the B and G genomes had originated from different accessions of Ae. speltoides.
Environmental and genetic determination of protein content and grain yield in durum wheat under Mediterranean conditions
Authors: Rharrabti Y. , Villegas D. , Garcia del Moral L. F. , Aparicio N. , Elhani S. , Royo C.
Published: March 2003

The unpredictability of the Mediterranean climate causes fluctuations in wheat yield and quality, but offers the opportunity for obtaining high‐quality durum wheat in terms of grain protein content. Twenty‐five durum wheat genotypes were grown under irrigated and rainfed conditions at each of two latitudes in Spain during 1998 and 1999. Differences between latitudes in grain protein content and chlorophyll content in the flag leaf were attributable to nitrogen fertilization management. Cycle length until anthesis was less affected by the environment than grain‐filling duration, and was longer under irrigated conditions than in the rainfed sites. A negative asymptotic curve was the best equation to fit the relationship between yield and protein content, suggesting that yield improvements in fertile environments may be attained with negligible reductions in protein content. ‘Jabato’, ‘Waha’, ‘Lagost‐3’, ‘Massara‐1’ and ‘Vitŕon’ showed medium to high yield, yield stability and high protein content. Chlorophyll content in the flag leaf, measured at anthesis with the soil‐plant analysis development (SPAD) portable field unit, may be useful for the fast and cheap detection of durum wheat genotypes with high grain protein content in drought‐stressed Mediterranean environments.
Morphological traits and high resolution RAPD markers for the identification of the main strawberry varieties cultivated in Argentina
Authors: García M. G. , Ontivero M. , Diaz Ricci J. C. , Castagnaro A.
Published: March 2003

Eight genotypes of the main Fragaria×ananassa cultivars grown in Argentina were analysed using the random amplified polymorphic DNA (RAPD) technique combined with electrophoresis in polyacrylamide gels. The high resolution of this procedure allowed the detection, with only 13 random primers, of 37 genotype‐specific bands that can be used as markers for verifying the identity of cultivars. By using this approach, three different accessions of the cultivar ‘Pájaro’ exhibited differences in amplification profiles, confirming the need for DNA analysis to prevent misidentification of cultivars. In addition, RAPD bands and morphological traits were used to assess genetic relatedness among cultivars. Comparison of both dendrograms revealed that there is no correlation between the clustering obtained with molecular and morphological characters.
Isolation and linkage mapping of disease‐resistance‐like sequences from various rice cultivars, containing different recognition specificities
Authors: Wang S. , Xiao X.
Published: March 2003

Degenerated oligonucleotide primers identified from the nucleotide‐binding sites of known disease resistance (R) genes were used from rice cultivars harbouring different recognition specificities to amplify and clone homologous sequences of R genes. A total of 68 non‐redundant clones, which showed various degrees of sequence homology to R genes, were obtained from 18 rice cultivars. These clones had a high degree of sequence diversity both in the nucleotides and in the predicted amino acids, and were classified into five groups using clustal analysis. Fifteen of the 68 clones were mapped to 17 loci on chromosomes 3, 5, 11 and 12 in the rice molecular linkage map. The loci of the mapped clones correlated with the locations of known rice R genes for blast resistance and bacterial blight resistance on chromosomes 11 and 12. Other mapped loci occurred in cluster on chromosome 3, and correlated with the position of a quantitative trait locus for bacterial blight resistance. The mapping of the R gene homologues may aid the identification and isolation of R gene candidates.
Inheritance of resistance to sunflower downy mildew races 1, 2 and 3 in cultivated sunflower
Authors: Rahim M. , Jan C. C. , Gulya T. J.
Published: March 2003

Sunflower downy mildew (SDM) caused by Plasmopara halstedii, is a major disease of sunflower. Eleven resistance genes have been identified, but allelic relationships among these genes are not clear. This study examined the inheritance and allelic relationships of genes conferring resistance to SDM races 1, 2 and 3 (virulence phenotypes 100, 300 and 700, respectively) and confirmed a twelfth resistance gene. Three USDA Plant Introductions, AMES 3235, PI 497250, and PI 497938, and three released lines, RHA 266, RHA 274 and DM‐2 were studied. RHA 266 has only the Pl1 gene for race 1 resistance. Digenic inheritance of resistance was found in AMES 3235, PI 497250, and RHA 274. These lines have the Pl1 and Pl12 genes, conferring resistance to race 1, and the Pl2 and Pl11 genes, conferring resistance to race 2. DM‐2 and PI 497938 have Pl12 (but not Pl1 for resistance to race 1, the Pl12 gene (but not the Pl2) for resistance to race 2, and Pl5 for resistance to race 3. These resistance genes will serve as a foundation for future gene designations and genetic diversity studies of resistance to SDM.
Molecular mapping of major genes and quantitative trait loci determining flowering time in response to photoperiod in barley
Authors: Börner A. , Buck‐Sorlin G. H. , Hayes P. M. , Malyshev S. , Korzun V.
Published: March 2003

Two major genes (eam8 and eam10) and two quantitative trait loci (QTL) determining flowering time in barley were associated with restriction fragment length polymorphism markers. The loci eam8 and eam10 were found to map in regions of chromosomes 1HL and 3HL, respectively, already estimated from previous classical linkage analyses. While investigating doubled haploid lines of a spring habit barley mapping population, two QTL for flowering time were detected on chromosomes 1HL and 7HS, respectively, when the material was grown under long photoperiod conditions. When growing the same lines under short photoperiod, no QTL were discernible. Allelic and homoeologous relationships with flowering time loci described earlier in barley and other Triticeae species are discussed.
Inheritance and stability of the virus‐resistant gene in the progeny of transgenic sweet potato
Authors: Okada Y. , Nishiguchi M. , Saito A. , Kimura T. , Mori M. , Hanada K. , Sakai J. , Matsuda Y. , Murata T.
Published: March 2003

Viral diseases of sweet potato are very prevalent and often seriously damaging to the plants. In particular, the severe strain of the sweet potato feathery mottle virus (SPFMV‐S) causes ‘obizyo‐sohi’ disease in Japan. In order to confer viral resistance against SPFMV using current biotechnology, a transgenic sweet potato has been produced, introducing hygromycin‐resistant (hpt) and SPFMV‐S coat protein (CP) genes, which have shown a significant resistance to SPFMV‐S. In the breeding programme, it is important to confirm that the viral resistance conferred in T0 plants can be inherited by their progeny. In the present study, progeny were obtained from crosses between the transgenic T0 and a non‐transgenic variety of sweet potato. The results showed that the CP gene was inherited by the next generation and that the stability of viral resistance was also confirmed. Thus, this production system for the virus‐resistant transgenic sweet potato is useful in practical breeding.
Bread‐making quality in hexaploid tritordeum with substitutions involving chromosome 1D
Authors: Ballesteros J. , Ramirez M. C. , Martinez C. , Barro F. , Martin A.
Published: March 2003

Hexaploid tritordeum, the amphiploid Hordeum chilense×Triticum turgidum, has potential for bread making. In order to estimate the potential of bread wheat chromosome 1D for improving the bread‐making quality of tritordeum, and the processing properties and agronomic performance of euploid tritordeum, (1Hch)1D and (1A)1D substitution lines have been evaluated in field trials. No significant differences for agronomical traits were observed between the two substitution lines and the sister euploid tritordeum, except for the kernel weight of the (1Hch)1D tritordeum substitution, which was lower than that of euploid tritordeum. Gluten strength, estimated by alveograph deformation energy (W), and loaf volume were substantially higher in both substitution lines than in the euploid tritordeum.
Factors Affecting the Reproductive Efficiency of Artificial Insemination Programmes in a Seasonal Breeding Pasture‐based Dairy System with the Aid of Milk Progesterone
Authors: Cavestany D , Galina CS
Published: March 2003

To determine the factors affecting reproductive efficiency in a seasonal breeding artificial insemination (AI) programme in dairy herds in Uruguay, a field trial was conducted on three dairy farms. Lactating cows (n=328) intended to be bred at the following breeding period were selected. The trial started 1 week before the beginning of the breeding period and lasted 80 days or until first service. Milk samples were obtained biweekly for 12 weeks, starting 1 week prior to the breeding season to determine progesterone concentrations. Data indicated that 12.5% of the cows were anoestrus at the beginning of the season remaining in this condition throughout the trial. Most of the anoestrous animals were first‐calf heifers. A varying number of cycling cows (8.5%) at each farm were never reported in heat. Oestrous detection rate for cows cycling, as determined by progesterone patterns, was evaluated in three periods of 21 days and resulted in an overall efficiency of 46.9%. Main factors affecting oestrous detection were farm, with an effect of parity (67.8%, mature cows and 33.2%, first‐calf heifers) and no effect of days postpartum. Mean interval from the beginning of the breeding season to first breeding was 27.4 days, which was also affected by farm. Neither parity nor days postpartum affected this parameter.
Active Immunization against Gonadotrophin‐releasing Hormone in Chinese Male Pigs
Authors: Zeng XY , Turkstra JA , Van De Wiel DFM , Guo DZ , Liu XY , Meloen RH , Schaaper WMM , Chen FQ , Oonk HB , Zhang X
Published: March 2003

We have investigated, under the normal conditions of local Chinese pig farming, castration of young male pigs by vaccination with a newly developed vaccine against gonadotrophin releasing hormone (GnRH). Because of the very early onset of puberty, long fattening period and relatively harsh circumstances in Chinese pig production, an investigation of the endocrine response of Chinese breeds to this type of vaccination was of particular interest. Fifteen crossbred boars (Yorkshire × Yanan) from three different litters were randomly assigned to three groups of five animals each. The first group was immunized at 13 weeks of age with a GnRH tandem dimer OVA‐conjugate in Specol and received a booster immunization 8 weeks later. The second group was injected with Specol alone and served as untreated controls. The remaining group was surgically castrated at the time of weaning (at 6 weeks of age). Pigs were fed ad libitum from weaning onwards. All animals were slaughtered at 31 weeks of age. Immunized boars had undetectable or low serum testosterone (0.09 ± 0.12 ng/ml), low fat androstenone (0.05 ± 0.01 μg/g) levels and very low testes weights (19.1 ± 4.3 g). Intact controls had much higher serum levels of testosterone (9.76 ± 4.81 ng/ml), fat androstenone levels (2.26 ± 0.87 μg/g) and testes weights (114.3 ± 29.41 g) at slaughter. Both the immunized and castrated group grew significantly faster than intact boars (p < 0.01). Average daily gains in immunized, castrated and intact animals were 0.69 ± 0.08, 0.63 ± 0.05 and 0.42 ± 0.07 kg (mean ± SD), respectively. The present data demonstrate for the first time that the newly developed anti‐GnRH vaccine works very well under practical Chinese pig farming conditions, and can be an attractive alternative to surgical castration.
From Co‐culture to Defined Medium: State of the Art and Practical Considerations
Authors: Vanroose G , Van Soom A , De Kruif A
Published: March 2003

Embryo culture in domestic and laboratory animals, and also in humans has developed significantly during recent decades. It is the aim of this review to consider the historical development of different culture systems, with a special emphasis on the recent tendency to remove somatic cells and undefined proteins from the culture systems for sanitary reasons. In addition to the sanitary aspect, developing more standardized culture conditions is useful for diminishing variation between laboratories and for studying the needs of the embryo.
Relationship Between Motility and Membrane Integrity of Boar Spermatozoa in Media Varying in Osmolality
Authors: Fraser L , Gorszczaruk K , Strzeżek J
Published: March 2003

A study was conducted to evaluate the relationship between boar sperm motility and membrane integrity following exposure to media with 150–1120 mOsm. Total sperm motility was defined as the percentage of spermatozoa that had any form of motility was subjectively assessed under a light microscope. Sperm cell damage was expressed as a loss of membrane integrity as measured by a combination of fluorescent stains, carboxyfluorescein diacetate (CFDA) and propidium iodide (PI), and Hoechst 33258 (H33258). There were no significant differences between sperm motility and membrane‐intact spermatozoa, as measured by CFDA‐PI and H33258, in media with 250 and 300 mOsm. In anisosmotic conditions, a higher amount of membrane‐intact spermatozoa than motile spermatozoa was observed. In hypo‐osmotic conditions (150 mOsm), a high proportion of spermatozoa had curled or coiled tails and most of them retained their entire membrane integrity, as detected by CFDA‐PI. In media with 350–1120 mOsm, some spermatozoa accumulated PI in the head region and CFDA in the mid‐piece. These spermatozoa fluoresced blue at the lower region of the head, as detected by H33258. The ATP content in spermatozoa exposed to hypo‐ and hyperosmotic conditions was markedly reduced. There was no recovery of sperm motility on returning the spermatozoa to isosmotic conditions after 10 min incubation in anisosmotic conditions, indicating that the spermatozoa suffered an almost complete and irreversible loss of motility. This irreversible loss of motility may be a consequence of reduced ATP production in spermatozoa subjected to anisosmotic conditions. The results of this study demonstrate that plasma membrane integrity assessment in combination with sperm motility, using a range of media varying in osmolality, can give valuable information about the status and function of different sperm membranes, which might be relevant for semen preservation.
Low Dose Insemination in the Sow – A Review
Authors: Rath D
Published: March 2003

Contents

Artificial insemination (AI) in pigs has been established for about four decades but ejaculates are still used insufficiently. Higher demand of semen for AI and new techniques that involve low sperm concentration require the optimization of insemination protocols. Based on the knowledge of the physiology of sperm transportation and events in the female genital tract prior to fertilization, new strategies are under development to minimize sperm losses. One goal is to deposit the semen into the uterine horn rather than into the proximal cervix. It was shown that the minimal number of spermatozoa necessary for surgical AI at the utero‐tubal junction (UTJ) were at least 1 × 106 diluted in 0.5 ml of a special extender. Artificial insemination into the distal part of the uterine horn required about 1 × 107 million sperm in 20 ml of extender. Meanwhile, first insemination devices for non‐surgical intra‐uterine AI are commercially available. Using similar sperm concentrations as for surgical AI, non‐surgical uterine insemination did not differ significantly from control inseminations in terms of pregnancy rate and litter size. With respect to the fertilizing capacities of their ejaculates, boars have to be selected more strictly for sperm quality parameters as most of the compensatory effects of sperm cells disappear in maximally extended semen samples.
Motility Characteristics and Fertilizing Capacity of Boar Spermatozoa Stained with Hoechst 33342
Authors: Vazquez JM , Martinez EA , Parrilla I , Gil MA , Lucas X , Roca J
Published: March 2003

Contents

Flow cytometry sorting of spermatozoa using fluorescence dye Hoechst 33342 is the only effective sex selection methodology validated in numerous laboratories. This study was carried out to determine the effect of Hoechst 33342 on the motility and fertility of stained boar spermatozoa. Experiment 1 evaluated motility parameters (percentage of motile spermatozoa, velocity, angularity and oscillation) of boar spermatozoa stained with Hoechst 33342 by a computer‐aided sperm analysis (CASA) instrument. Spermatozoa (30 million/ml) were divided into five treatment groups and stained during 1 h at 35°C with 9, 18, 27, 60 and 90 μM of H33342. There were no differences in sperm motility patterns nor percentages of motile spermatozoa incubated in the presence of 9, 18 or 27 μM. Percentage of motile spermatozoa and motility parameters decreased significantly (p < 0.05) at 60 μM of Hoechst 33342. Spermatozoa were immotile at concentration of 90 μM. In experiment 2, pregnancy rates, farrowing rates and litter size from sows (n = 275) artificially inseminated (AI) with either Hoechst 33342 stained (27 μM) or unstained (control) spermatozoa were determined. Sows inseminated with stained spermatozoa had no significant lower pregnancy rate (88.33%) as compared with controls (90.32%). Staining neither affected farrowing rates (85.0 vs 87.7%) nor total number of piglets born (10.56 ± 0.32 vs 10.47 ± 0.24, stained and controls, respectively). No phenotypical abnormalities were registered among the newborn piglets. The data suggest that incubating spermatozoa with Hoechst 33342 at levels required for X‐ and Y‐bearing chromosome sperm sorting, does not impair sperm viability or their fertility after AI.
Investigations on the Re‐establishment of the Positive Feedback of Oestradiol during Anoestrus in the Bitch
Authors: Klein R , Schams D , Failing K , Hoffmann B
Published: March 2003

Contents

To test for the re‐establishment of the positive feedback of oestradiol (E2) during anoestrus in the dog, the hypothalamo–pituitary–ovarian axis of five beagle bitches was challenged by treatments with oestradiol benzoate (EB), mimicking the course of the pro‐oestric E2 secretion. Treatments in anoestrus started 7 days following the decline of progesterone (P) <1 ng/ml; they were repeated in 5 week intervals until onset of pro‐oestrus; another treatment was performed during dioestrus 50 days after onset of the preceding pro‐oestric bleeding. Each dog served as its own control by receiving vehicle‐treatments in one of the following cycles. Each observation period covered a time window of 168 h and blood samples were collected for the determination of luteinizing hormone (LH), follicle‐stimulating hormone (FSH) and E2 in 6 (0–24 h) and 8 h (24–168 h) intervals. In the control periods and as indicated by the parameters area under curve (AUC), basal and maximal values, the availability of LH, FSH and E2 decreased from dioestrus to early anoestrus to increase again during the course of anoestrus (p < 0.05), indicating a gradual desensitization of the hypothalamus towards the negative feedback of oestradiol. At all times treatments with EB lowered the availability of FSH (decreased AUC and basal levels). A delay in the occurrence of the first LH peak after treatments with EB (p < 0.001) and decreased maximal values (p < 0.001) indicated a suppression of the LH‐release. In no case treatment with EB led to a pre‐ovulatory like LH‐surge. In each dog the last trial with EB in anoestrus passed over into pro‐oestrus/oestrus, with a reduced AUC and peak value of the pre‐ovulatory LH‐surge being the only differences to the control group. The observed differences in the response of LH and FSH to treatments with EB point towards subtle differences in the mechanisms controlling the release of these two hormones during anoestrus. From the data obtained, it may be concluded that the time window for E2 to act via a positive feedback seems to be very small and restricted to the end of anoestrus, and that full follicular function is a pre‐requisite to allow for this phenomenon.
The psychiatric consultation‐liaison nurse: Thriving in a general hospital setting
Authors: Sharrock Julie , Happell Brenda
Published: March 2003

ABSTRACT:

One outcome of mainstreaming of psychiatric services into the general health system is that nurses working in general hospitals now have increased contact with patients experiencing mental health problems. The literature suggests that general and comprehensive nurses do not believe they have the skills, confidence and knowledge to care adequately for patients in their care who have a mental health problems. The Psychiatric Consultation‐Liaison Nurse (PCLN) can assist and educate general nurses in the care of patients with mental health problems who are receiving care in a medical/surgical setting. This study is based upon the findings of a Nurse Practitioner Pilot Study funded by the Department of Human Services (Victoria). In this paper the authors will present a brief overview of the role and model of practice of the PCLN, the means of referral, a profile of consultations and an overview of educational and policy development activity. The findings of the evaluation based on a combination of a Health Professional Satisfaction Survey and Focus Group Interviews will also be presented. The positive contribution of the PCLN to the confidence of nurses and how this might impact on patient outcomes will be highlighted. The value placed on the PCLN role by general hospital staff is evidence of psychiatric nursing not just surviving but thriving.
Aggressive behaviour and burnout among staff of homes for the elderly
Authors: Evers Will , Tomic Welko , Brouwers André
Published: March 2003

ABSTRACT:

This study examines relationships between experienced aggressive behaviour and burnout of staff caring for residents living in homes for the elderly (n = 551). Burnout was conceptualized as a three‐dimensional syndrome consisting of emotional exhaustion, depersonalization and reduced personal accomplishment. From the results of the hierarchical regression analyses it appeared that physical and psychological aggression and the number of weekly working hours had a significant relationship with emotional exhaustion of staff. Psychological aggression was found to have a significant relationship with depersonalization. Neither sex nor age had a relationship with any of the burnout dimensions. Implications for research and suggestions for work and training of staff caring for the elderly are discussed.
Transformative change of self: The unique focus of (adolescent) mental health nursing?
Authors: Geanellos Rene
Published: March 2003

ABSTRACT:

In mental health nursing, inadequate nursing practice research has resulted in a deficit of knowledge concerning the nurse–client relationship; an area seen as the heart of practice. In turn, the specialty has experienced difficulty in identifying its unique domain of practice. Findings from a hermeneutic study into adolescent mental health nursing explicated its practice knowledge. These findings include (i) ‘engaging in therapeutic relationships’; (ii) ‘guiding the potential for change’; and (iii) ‘facilitating positive outcomes’. A higher order finding was named ‘fostering a functional self’. These findings are discussed. Findings point to the nature, purpose and processes of the nurse–client relationship, and to outcomes from that relationship. It is suggested they also represent a beginning understanding of the specialty's unique contribution to nursing; that mental health nursing fosters transformative change of self.
Does prior training and staff occupation influence knowledge acquisition from an aggression management training program?
Authors: Ilkiw‐Lavalle Olga , Grenyer Brin F. S. , Graham Linda
Published: March 2003

ABSTRACT:

Aggression management training has become mandatory for mental health staff in New South Wales, Australia. This study explores the differential effects of knowledge acquisition following a 2‐day intensive training program for 103 mental health staff comprising three groups: (i) nurses, (ii) allied and medical staff, and (iii) ancillary staff. All occupations had significant knowledge gains following training, although knowledge acquisition was less for staff with prior training than for those without. Results suggest previously trained staff would be better suited to shorter, more frequent, on ward skills‐based refresher training.
TNF‐α production in the cornea in response to Pseudomonas aeruginosa challenge
Authors: Cole Nerida , Bao Shisan , Willcox Mark , Husband Alan J
Published: March 2003

Pseudomonas aeruginosa can cause ulcerative bacterial keratitis or contact lens‐induced acute red eye (CLARE) in humans. The present study used a mouse model of ocular infection and inflammation to examine the relationship between TNF‐α and inflammation in the cornea in response to challenge with either a strain of P. aeruginosa causing keratitis or a CLARE strain. Constitutive TNF‐α mRNA was detected in the epithelium, mainly towards the periphery. After infection with the keratitis‐inducing strain (6294), TNF‐α expression was elevated four‐fold by 24 h post‐challenge. No detectable induction of TNF‐α mRNA was seen with CLARE strain (Paer1) challenge at any time point. The TNF‐α protein production detected by ELISA showed a corresponding pattern to the mRNA expression, which also correlated with pathological changes. These results suggest that invasive strains of P. aeruginosa create greater pathological changes as a result of elevated TNF‐α production, which contributes to inflammation during keratitis in vivo.
Rapamycin inhibits didemnin B‐induced apoptosis in human HL‐60 cells: Evidence for the possible involvement of FK506‐binding protein 25
Authors: Johnson Karina L , Lawen Alfons
Published: March 2003

In the present paper we show that the immunosuppressant rapamycin inhibits the induction of apoptosis by didemnin B in human promyeloid HL‐60 cells. The mechanism of this inhibition is investigated using FK506, which competes with rapamycin for binding to their common target FK506‐binding protein (FKBP)12. The lack of competition for rapamycin‐mediated inhibition of didemnin B‐induced apoptosis by FK506 suggests that rapamycin inhibits apoptosis through some mechanism other than inhibition of p70 S6 kinase activation. The lack of inhibition of didemnin B‐induced apoptosis by inhibitors of phosphatidylinositol 3‐kinase and mitogen‐activated protein (MAP) kinase kinase further supports the conclusion that rapamycin does not inhibit didemnin B‐induced apoptosis through inhibition of the MAP kinase pathway. Furthermore, didemnin B‐induced apoptosis is not inhibited by the inhibitors of cyclin‐dependent kinase, roscovitine and olomoucine. This indicates that rapamycin does not act through inhibition of cyclin‐dependent kinases. Together with the lack of competition for the effect of rapamycin by FK506, our data suggest the possible involvement of the FK506‐binding protein, FKBP25, which is localized in the nucleus. This interpretation of our data gains support from the fact that didemnin B does not induce apoptosis in enucleated HL‐60 cells, which supports the possible involvement of FKBP25 in the inhibition of apoptosis by rapamycin.
Mucosa‐associated lymphoid tissues as sites for uptake, carriage and excretion of tubercle bacilli and other pathogenic mycobacteria
Authors: Lugton IW
Published: March 2003

Pathogenic mycobacteria, including those that cause tuberculosis and paratuberculosis, cross mucosal barriers by endocytosis within mucosal lymphoepithelial sites. These entry sites commonly include oropharyngeal and nasopharyngeal tonsils and Peyer's patches. Bacilli discharged at the basolateral surfaces of engulfing epithelial M cells are taken up by professional antigen‐presenting cells associated with T lymphocytes of the parafollicular area. Dendritic cells and macrophages in these sites allow mycobacterial replication, due to the permissive immunological environment in lymphoepithelial tissues. Abrogation of local delayed‐type hypersensitivity reactions generally ensures continuing integrity and function of these tissues. Phagocytes containing intracellular mycobacteria disseminate infection to other parts of the body and also probably migrate back onto the mucosal surface to shed bacilli.
The use of carboxyfluorescein diacetate succinimidyl ester to determine the site, duration and cell type responsible for antigen presentation in vivo
Authors: Mintern Justine , Li Ming , Davey Gayle M , Blanas Effrossini , Kurts Christian , Carbone Francis R , Heath William R
Published: March 2003

This report examines the use of 5‐(and‐6)‐carboxyfluorescein diacetate succinimidyl ester (CFSE) to determine the site, duration and cell type responsible for antigen presentation in vivo. Evidence that CFSE‐labelled T cells can be used to determine where various types of antigens are presented, including auto‐antigens, oral antigens and cell‐associated foreign antigens, is provided. Using this technique, the length of time antigen is presented after acquisition by APC was measured. Finally, CFSE labelling was used to identify the origin of the APC responsible for different forms of antigen presentation.
Somatic hypermutation of immunoglobulin κ transgenes: Association of mutability with demethylation
Authors: Jolly Christopher J , Neuberger Michael S
Published: March 2003

Following antigen encounter, immunoglobulin genes are diversified by somatic hypermutation. The mechanism by which this mutational process preferentially targets immunoglobulin genes is not known, but is likely linked to transcription. However, transcription is not sufficient to ensure mutability. Here, by polymerase chain reaction amplification of bisulfite‐modified DNA, the pattern of demethylation within the Igκ mutation domain is analysed and transgenes are used to identify an association between demethylation and mutability. In mice carrying an Igκ transgene that is well transcribed but only poorly targeted for hypermutation, the mutated transgene copies have been demethylated within the mutation domain, whereas the methylated copies remain unmutated. Thus, the hypermutation mechanism only acts on immunoglobulin gene targets that are demethylated as well as transcribed, although transcription and demethylation do not themselves guarantee mutability.
Role and significance of the complement system in mucosal immunity: Particular reference to the human breast milk complement
Authors: Ogundele Michael O
Published: March 2003

The complement system plays an important role in a host's defence mechanisms, such as in immune bacteriolysis, neutralization of viruses, immune adherence, immunoconglutination and in enhancement of phagocytosis. The possible role of this important biological system in biological fluids on the mucosal surfaces, including breast milk, has however been largely neglected. Its contribution to the ‘common’ mucosal immunity is still enigmatic and largely speculative. Assessment of the complement system in human breast milk, which has so far largely been limited to different assays of the individual component proteins, is reviewed. A brief review of the classical and the alternative pathways of complement activation is presented. The potential physiological roles of various complement components and their activation fragments in human milk in particular, and other mucosal surfaces in general, are also presented. It was concluded that the complement system might play a complementary role to other immunological and non‐immunological protective mechanisms on the mucosal surfaces.
Epithelium–fibroblast interactions in response to airway inflammation
Authors: Knight Darryl
Published: March 2003

Dramatic changes to the architecture of the airway walls have been commonly described in the airways of patients with asthma, cystic fibrosis (CF) and chronic obstructive pulmonary disease (COPD). Much research has focused on how airway inflammation drives these structural changes, particularly in terms of the mechanisms/mediators that are involved, and a number of parallels are observed between the disease phenotypes. For example, the increased deposition of extracellular matrix (ECM) at focal sites in the airway wall is seen in asthma and all interstitial lung diseases that involve fibrosis. In addition, increased expression of a number of well characterized cytokines and growth factors, such as TGF‐β and epidermal growth factor (EGF) have been demonstrated in these diseases. However, the role of the lesser‐known cytokines, including the leukaemia inhibitory factor (LIF) and other members of the IL‐6 family of cytokines in the pathogenesis of airway remodelling and fibrosis is largely unknown. However, the use of genetic manipulation in vivo and more specific inhibitors/antibodies in vitro has now provided increasing evidence to support the hypothesis that a complex interaction exists between these cytokines, ECM and integrins in regulating the function of both epithelial cells and fibroblasts.
Peptide immunization of guinea pigs against Chlamydia psittaci (GPIC agent) infection induces good vaginal secretion antibody response, in vitro neutralization and partial protection against live challenge
Authors: Volp K , Mathews S , Timms P , Hafner LM
Published: March 2003

Immunization of female guinea pigs with a chimeric peptide consisting of variable domain IV (VDIV) and a region known as GP8 from the major outer membrane protein of Chlamydophila caviae, formerly Chlamydia psittaci guinea pig inclusion conjunctivitis strain, was performed to assess whether humoral immune responses could be elicited in the reproductive tracts of immunized animals. The C. caviae strain is able to cause a sexually transmitted infection in the guinea pig that closely parallels C. trachomatis infections in humans. The best anti‐VDIV antibody response in vaginal secretions was achieved by intraperitoneal priming with subsequent intravaginal boosting (P < 0.001). Dot‐blot analyses of vaginal secretions confirmed that these anti‐VDIV antibodies, produced against a linear peptide, were able to recognize and bind to whole conformational C. caviae elementary bodies. Following live intravaginal challenge with C. caviae, a significant reduction in the intensity (P = 0.01) and an apparent reduction in the duration of the infection was evident between the guinea pigs immunized with VDIV‐GP8 and non‐immunized controls.
Macrophage–neutrophil interaction: A paradigm for chronic inflammation revisited
Authors: Lefkowitz Doris L , Lefkowitz Stanley S
Published: March 2003

Macrophages have been described as ‘factories’ of pro‐inflammatory cytokines. Several years ago the present investigators reported that binding of inactive myeloperoxidase (iMPO) to the macrophage‐mannose receptor resulted in the induction of TNF and other cytokines. Also, if endothelial cells were incubated with iMPO, but not enzymatically active myeloperoxidase (MPO), upregulation of cytokine mRNA and cytokines was observed. Taken in their entirety, the data suggest a dichotomy of function for myeloperoxidase; that is, enzymatically active MPO functions primarily in cell killing through the ‘cytotoxic triad’ and iMPO functions as an immunoregulatory molecule through the induction of numerous cytokines. These studies underscore a previously unrecognized interaction among neutrophils, endothelial cells and macrophages, resulting in the induction of TNF and perpetuation of inflammation. The inflammation induced could be relevant in a number of diseases in which neutrophils play a prominent role. The importance of this interaction in the pathogenesis of rheumatoid arthritis is currently under investigation.