bluuebunny/crossref_metadata_2025 huggingface dataset:
Improving crop competitive ability using allelopathy — an example from rice
Authors: Olofsdotter M. , Jensen L. B. , Courtois B.
Published: March 2003

The objective of this paper is to review the possibilities for using allelopathy to improve overall crop competitive ability against weeds, using rice, Oryza sativa, as an example. Laboratory, greenhouse and field screenings for allelopathy and overall weed suppression in rice have been made and allelopathic rice germplasm has been identified in laboratory and greenhouse screening. Field experiments revealed that allelopathy accounted for 34% of overall competitive ability in rice. For strongly allelopathic cultivars, allelopathy was the dominant factor determining competitive ability. Based on the results of the screenings, recombinant inbred line populations were developed for identification of quantitative trait loci (QTL) controlling allelopathy. Populations of recombinant inbred lines (RILs) were derived through single‐seed descent from crosses between varieties with contrasting behaviour and QTL controlling allelopathy were identified. For rice and most probably also for other cereal crops, the findings presented can explain the limited success in previous breeding programmes for weed competition, as allelopathy has never before been acknowledged as an important factor. The findings in allelopathy indicate that it is possible to improve allelopathy in rice using marker‐assisted selection. Optimizing allelopathy in combination with breeding for competitive plant types could result in crop cultivars with superior weed‐suppressive ability.
Quantitative trait loci for scald resistance in barley localized by a non‐interval mapping procedure
Authors: Jensen J. , Backes G. , Skinnes H. , Giese H.
Published: March 2003

Three quantitative trait loci (QTL) for scald resistance in barley were identified and mapped in relation to molecular markers using a population of chromosome doubled‐haploid lines produced from the F1 generation of a cross between the spring barley varieties ‘Alexis’ and ‘Regatta’. Two field experiments were conducted in Denmark and two in Norway to assess disease resistance. The percentage leaf area covered with scald (Rhynchosporium secalis) ranged from 0 to 40% in the 189 doubled‐haploid (DH) lines analysed. One quantitative trait locus was localized in the centromeric region of chromosome 3H, Qryn3, using the MAPQTL program. MAPQTL was unable to provide proper localization of the other two resistance genes and so a non‐interval QTL mapping method was used. One was found to be located distally to markers on chromosome 4H (Qryn4) and the other, Qryn6, was located distally to markers on chromosome 6H. The effects of differences between the Qryn3, Qryn4 and Qryn6 alleles in two barley genotypes for the QTL were estimated to be 8.8%, 7.3% and 7.0%, respectively, of leaf covered by scald. No interactions between the QTLs were found.
The presence or absence of the soybean Kunitz trypsin inhibitor as a quantitative trait locus for seed protein content
Authors: Vollmann J. , Schausberger H. , Bistrich H. , Lelley T.
Published: March 2003

Numerous quantitative trait loci (QTL) for various characters have recently been reported in different crop plants. However, information is limited about the molecular mechanisms behind QTL, because most of them have only been detected at a statistical level. Therefore, progeny from a cross between two soybean genotypes segregating for the presence vs. absence of the Kunitz trypsin inhibitor, a 21.5 kDa protein, have been analysed for possible effects of that protein on agronomic and seed quality characters. Protein content was reduced by, on average, 4.5 g/kg in segregants lacking the Kunitz protein, whereas oil content and other characters remained unaffected. This finding can be interpreted as a ‘model QTL’ for variation in seed protein content, because the molecular and genetic backgrounds of the soybean Kunitz trypsin inhibitor are well understood.
In vitro chromosome doubling of Miscanthus sinensis
Authors: Petersen K. K. , Hagberg P. , Kristiansen K. , Forkmann G.
Published: March 2003

The aim was to develop an efficient chromosome doubling method for Miscanthus sinensis to enable the production of triploids and so avoid seed dispersal to the environment. Antimitotic treatments with colchicine or oryzalin were tested in M. sinensis cl. MS‐88‐110 on: (1) in vitro shoots and plants established in soil; (2) during propagation of embryogenic callus; and (c) during the initial stages of callus induction. All systems produced chromosome‐doubled plants. A higher percentage of tetraploids was found after antimitotic treatment at the explant or callus level compared with treatment of in vitro shoots or plants established in soil. In general, oryzalin was more toxic to plant material than colchicine. A higher frequency of chimeras was found among plants with altered ploidy level when the target was formed shoot buds compared with adventitious shoot formation from callus. Antimitotic treatment of embryogenic callus from shoot apices also resulted in a high degree of albinism.
Characteristics of Buck Semen with Regard to Ejaculate Numbers, Collection Intervals, Diluents and Preservation Periods
Authors: Shamsuddin M , Amiri Y , Bhuiyan Mmu
Published: March 2003

Contents

To determine the number of ejaculates which can be collected within a 20‐min period after the smallest number of days of sexual rest, and a good diluent to preserve semen for routine AI, five mature Black Bengal bucks were used in three experiments. In experiment 1, semen from the bucks were collected by using artificial vagina at homosexual mounts as many times as possible during 20 min. The ejaculate numbers 1, 3 and 4 (or 5 when the buck could produce it) were examined for important semen characteristics. The mean ejaculate volume, density, mass activity, sperm motility, sperm concentrations, total spermatozoa/ejaculate, proportion of spermatozoa with normal acrosome, midpiece and tail, and the proportion with normal head morphology varied between 267 and 342 µl, 4.1–4.5 (1–5 scale), 4.1–4.2 (1–5 scale), 77–79%, 4187 × 106–5064 × 106/ml, 1140 × 106–1746 × 106, 91–94% and 99%, respectively, depending on the collection number of the ejaculate. The difference between the ejaculates was significant only with respect to volume (p < 0.05). In experiment 2, semen was collected from the bucks successively during 20 min after 1, 2, 3 and 4 day intervals, and the first ejaculates were evaluated for the above‐mentioned semen characteristics. Semen collected after 2 or more day intervals had significantly higher volume, sperm concentration and total spermatozoa/ejaculate (p < 0.05). In experiment 3, pools of two to three ejaculates were diluted (1 : 5; semen : diluent) in splits with glucose‐citrate‐egg yolk (GCEY), Tris‐fructose‐egg yolk (TFEY) or skim milk (SM) and preserved at +4 to +7°C. Before chilling or after 0 (15 min chilling), 1, 2, 3 and 4 days of preservation, semen was evaluated for motility and proportion of normal spermatozoa with respect to acrosome, midpiece and tail. In data pooled across the bucks, the sperm motility was better in GCEY and TFEY than in SM, and the proportion of normal spermatozoa was higher in SM than in the others (p < 0.05). However, the differences in proportion of normal spermatozoa between diluents were not significant when the data were analysed separately within preservation periods. The sperm motility consistently dropped after 1 day of preservation (p < 0.01); the motility remained 50% or more up to 4 days in TFEY, 3 days in GCEY and only 2 days in SM. The proportion of spermatozoa with normal acrosome, midpiece and tail, which was generally quite high ( 90%), decreased after 3 days of preservation (p < 0.01). We conclude that Black Bengal bucks can be collected three times during 20 min, every 3 days, and that buck semen holds good motility and proportion of normal spermatozoa up to 3 days in GCEY or TFEY at 4 to 7°C.
Antioxidative Defence Mechanisms in Bovine Placenta and their Importance for Placental Release
Authors: Kankofer M
Published: March 2003

Contents

Reactive oxygen species, although unavoidable intermediates, may have positive and negative effects on tissue and cells. There is some evidence that imbalance between production and neutralization of reactive oxygen species may lead to peroxidative changes of cells, disturbances of the metabolism and in consequence disorders such as, among others, the retention of fetal membranes, udder oedema and mastitis in cows. Defence mechanisms against reactive oxygen species consist of enzymatic and nonenzymatic systems. This review examines the available literature regarding the activity of enzymatic and nonenzymatic defence mechanisms against reactive oxygen species in bovine placenta. Its importance for placenta release in cows is also discussed.
Improving in vitro Maturation of Oocytes in the Human Taking Lessons from Experiences in Animal Species
Authors: Smitz J , Nogueira D , Albano C , Cortvrindt R , Devroey P
Published: March 2003

One to three per cent of infertile women develop severe ovarian hyperstimulation syndrome after superovulation for assisted reproduction treatment (ART). This severe complication can be avoided when oocytes are obtained at an immature stage (germinal vesicle stage) out of small or medium‐sized follicles. This hypothesis has been tested in several infertile women, but clinical pregnancies are disappointlingly low. This new approach in ART is still at an experimental phase and this treatment has still to be improved before routine clinical application. Experimental work in animals and humans suggest a beneficial effect in providing a short preliminary pretreatment with follicle‐stimulating hormone to select for a developing cohort of follicles. The aspiration of oocyte cumulus complexes is carried out with a short needle applying reduced aspiration pressure. A crucial point is to provide the appropriate culture environment for the immature oocytes. An optimal cumulus‐enclosed human oocyte culture system needs to be defined. The composition of the culture medium could be suggested by in vitro work carried out in animal models. As developmental competence is established during the latest phases of oocyte growth and is dependent on the storage of RNA, a prolonged in vitro maturation period (before inducing nuclear maturation) could provide the necessary transcriptional and translational changes. The conditions to achieve this improved cytoplasmic maturation by prolonging the in vitro culture remain to be defined. More objective noninvasive parameters for oocyte maturity are also needed to pursue research in this field.
Local Effect of the Corpus Luteum on Ovarian Follicular Functional and Morphological Features in the Goat
Authors: González F , Batista M , Cabrera F , Calero P , Alabart JL , Gracia A
Published: March 2003

Ovaries of unilaterally ovulated goats (n=21) were used to study follicular morphological features (proportion and degree of atresia, oestradiol production in vitro and progesterone production of granulosa cells in culture). Follicles were dissected out and classified as small (1–2 mm), medium (2–4 mm) and large (>4 mm). Morphological and physiological features were compared in each size class between ovaries bearing and not bearing corpora lutea (CLO and NCLO, respectively). Within the same size class, there was no difference in proportion or in degree of atresia, between CLO and NCLO. A significant effect of follicular size on oestradiol production in vitro was detected, but no effect of the corpus luteum was found. Finally, progesterone production of granulosa cells in culture was significantly higher in CLO than in NCLO after 24 h (p < 0.05) and also after 90 h (p < 0.01) of culture. This higher progesterone production by CLO granulosa cells in culture could be explained by local influence of the corpus luteum stimulating the steroidogenic activity but not aromatase activity. Further studies are needed to clarify possible factors and pathways for this local effect of the corpus luteum upon follicular physiology.
Neuroendocrine Regulation of Growth Hormone and Luteinizing Hormone in Fetal and Neonatal Pig
Authors: Parvizi N , Ellendorff F , Elsaesser F
Published: March 2003

Ontogeny of the production and the regulation of growth hormone and Luteinizing hormone is studied in a series of experiments utilizing male and female pigs at different fetal and neonatal stages. Growth hormone mRNA is detectable in both sexes as early as d. 50 p.c. The mRNA levels increase to reach the maximum levels at d. 95–110 p.c. Plasma levels of GH follow the developmental patterns of GH mRNA. A sex difference is evident around d. 80–90 p.c. with males having higher GH levels than females. The stimulatory but not the inhibitory mechanisms of GH secretion are fully functioning in the pig fetus. LHβ mRNA is detectable earlier in females (d. 50 p.c.) than in males (d. 65 p.c.). Plasma concentrations of LH increase with fetal age in female fetuses, but in male fetuses there is no distinct developmental pattern evident. Basal LH secretion achieves maximum levels in both sexes after birth. Opioids do modulate fetal LH secretion, however, the mode of their action is age‐dependent.
Correlation between the Cell Number and Diameter in Bovine Embryos Produced In Vitro
Authors: Mori M , Otoi T , Suzuki T
Published: March 2003

Contents

This study was designed to examine the effects of age and developmental stage of in vitro‐produced bovine embryos on the cell number of the embryos and to investigate the correlation between the cell number and diameter in the embryos. The diameter and cell number in blastocysts and expanded blastocysts collected on days 7–9 after in vitro fertilization (IVF) were examined. Although the diameters of the blastocysts collected on days 7 and 8 after IVF were smaller than those of the expanded blastocysts collected on day 9, the cell number in both types of embryos was similar. The cell numbers of the blastocysts and expanded blastocysts decreased with increasing embryo age. There were positive correlations between the cell number and diameter in bovine embryos at each stage collected on each day after IVF. However, the value of the correlation coefficient in the day‐9 expanded blastocyst group tended to be higher than that in the other groups. These results indicate that the cell number of in vitro‐produced embryos is affected by the embryonic stage and age. The diameter of the embryo may be potentially used for the viability testing of the expanded blastocysts collected on day 9 after IVF.
Sialomucin Complex (Muc4) Expression in Porcine Endometrium During the Oestrous Cycle and Early Pregnancy
Authors: Ferrell AD , Malayer JR , Carraway KL , Geisert RD
Published: March 2003

Contents

The non‐invasive type of implantation in the pig is characterized by the maintenance of a thick glycocalyx coating on the uterine epithelial surface microvilli. Present study investigated the alteration in the sialomucin complex (Muc4) expression during the oestrous cycle and early pregnancy in the pig. Endometrial tissue samples were immunostained with the primary antibody to the Muc4 transmembrane subunit ASGP‐2. Muc4 immunostaining increased in the surface and glandular epithelia between days 5 and 10 of oestrous cycle. Immunostaining continued to increase on day 12 with the greatest intensity of uterine Muc4 immunostaining detected on day 15 of the oestrous cycle and early pregnancy. Endometrial Muc4 expression in cyclic gilts decreased dramatically during early proestrous but continued to remain abundant in the surface and glandular epithelium of pregnant gilts during the period of conceptus attachment to the uterine surface.
Development and evaluation of a training program in peer support for former consumers
Authors: Meehan Tom , Bergen Helen , Coveney Claire , Thornton Robert
Published: March 2003

ABSTRACT:

While mental health policy in Australia promotes the involvement of mental health consumers in service planning, implementation and evaluation, little has been reported on the training required for the new roles that consumers are being expected to undertake. In this study, 10 former consumers of mental health services participated in a 16‐week training program in peer support. The impact of the program on the psychological well‐being of the participants was assessed using a battery of self‐evaluation questionnaires and focus group interviews. Findings suggest that exposure to people with acute mental health problems (i.e. inpatients), did not, in this instance, adversely impact on the psychological well‐being of the participants. Barriers to consumer participation in the mental health field are discussed and recommendations for the content and structure of future consumer peer support training initiatives are proposed.
Second symmetry in the BALB/c‐C57BL/6 (B6) system, and anti‐antiself antibodies in ageing B6 mice
Authors: Al‐Fahim Abdulaziz , Hoffmann Geoffrey W
Published: March 2003

Using an ELISA assay and inhibition of antibody mediated cytotoxicity we found that there was a higher level of anti‐antiself activity in B6 anti‐BALB/c alloimmune mice than in BALB/c anti‐B6 mice. In contrast, when an inhibition of cellular cytotoxicity assay was used to assay for the activity, similar levels of anti‐antiself antibodies were seen in B6 anti‐BALB/c and BALB/c anti‐B6 sera. Anti‐antiself antibodies in alloimmune sera are not absorbed by the cellular immunogen as readily as are anti‐foreign antibodies. These results are interpreted in terms of anti‐antiself antibodies being directed mainly against T cell receptors specific for self. Anti‐antiself antibodies are found also in old B6 mice, that are also known to make autoantibodies.
Deciphering the apoptotic pathway: All roads lead to death
Authors: Lincz Lisa F
Published: March 2003

Research into apoptosis is proceeding at such a fast and ferocious pace that anyone who is not completely engrossed in the field has difficulty keeping track of the constant stream of newly identified proteins involved in the process. Apart from being an enticing concept, the process of cell suicide is an important function with wide‐reaching implications. Virologists, biologists, immunologists, physiologists and oncologists alike have had to incorporate this phenomenon into their disciplines. The purpose of this article is to provide a solid background on which to further review recent advances in this exciting field. The Bcl‐2 and caspase family homologues are discussed in detail and various models are proposed to explain how they function to regulate and execute the death programme. Finally, the importance of programmed cell death with respect to immune function is explored, emphasizing the targets of viral inhibitors of apoptosis.
Optimization of vaccine responses in early life: The role of delivery systems and immunomodulators
Authors: Kovarik Jiri , Siegrist Claire‐Anne
Published: March 2003

Infant immunization is a particularly important field with multiple challenges for vaccine research and development. There is, together with a high susceptibility to infections, a lower efficacy of most vaccinations in newborns and young infants, compared to those performed later in life. In the present review, the authors focus on problems arising from the attempt to vaccinate against pathogens very early in life, and on the role of selective adjuvants (i.e. antigen delivery systems or immunomodulators) that could be used to: (i) rapidly induce strong antibody responses of the appropriate isotypes; (ii) elicit sustained antibody responses extending beyond infancy; (iii) induce efficient Th1 and CTL responses in spite of the preferential Th2 polarization of early life responses; (iv) escape from maternal antibody mediated inhibition of vaccine responses; (v) show acceptable reactogenicity in early life; and (vi) allow incorporation of several vaccine antigens into a single formulation so as to reduce the number of required injections. How such objectives might be achieved by several of the vaccine formulations currently in development is illustrated by reviewing data from experimental models and clinical studies, when available.
PCR amplification of murine immunoglobulin germline V genes: Strategies for minimization of recombination artefacts
Authors: Zylstra Paula , Rothenfluh Harald S , Weiller Georg F , Blanden Robert V , Steele Edward J
Published: March 2003

Murine immunoglobulin germline V genes exist as multiple sequences arranged in tandem in germline DNA. Because members of V gene families are very similar, they can be amplified simultaneously using the polymerase chain reaction (PCR) with a single set of primers designed over regions of sequence similarity. In the present paper, the variables relevant to production of artefacts by recombination between different germline sequences during amplification are investigated. Pfu or Taq DNA polymerases were used to amplify from various DNA template mixtures with varying numbers of amplification cycles. Pfu generated a higher percentage of recombination artefacts than Taq. The number of artefacts and their complexity increased with the number of amplification cycles, becoming a high proportion of the total number of PCR products once the ‘plateau phase’ of the reaction was reached. Recombination events were located throughout the ∼ 1‐kb product, with no preferred sites of cross‐over. By using the minimally detectable PCR bands (produced by the minimum number of amplification cycles), recombination artefacts can be virtually eliminated from PCR amplifications involving mixtures of very similar sequences. This information is relevant to all studies involving PCR amplification of members of highly homologous multigene families of cellular or viral origin.
Suppressive effects of serum on the LPS‐induced production of nitric oxide and TNF‐α by a macrophage‐like cell line, WEHI‐3, are dependent on the structure of polysaccharide chains in LPS
Authors: Ohki Kazunori , Amano Fumio , Yamamoto Shunsuke , Kohashi Osamu
Published: March 2003

The effect of serum on LPS‐induced activation of a murine macrophage‐like cell line, WEHI‐3, was examined. Foetal calf serum strongly inhibited the production of nitric oxide (NO) and TNF‐α by LPS‐stimulated WEHI‐3 cells, while it enhanced the production of both by other macrophage‐like cell lines, J774.1 and BAM3, on treatment with LPS. This suppressive effect of serum on WEHI‐3 cells was most remarkable when the cells were stimulated with rough‐chemotype LPS, Ra LPS, Rc LPS and Rd2 LPS. Foetal calf serum also inhibited TNF‐α production by the same cells stimulated with high concentrations of smooth‐form LPS (S LPS; > 1000 ng/mL). Serum‐mediated suppression was also observed for expression of the TNF‐α gene in Rc LPS‐stimulated WEHI‐3 cells. This suppressive effect of FCS was most remarkable during the 1–2 h before the addition of LPS, but it was not observed when FCS was added at 1 h after the addition of LPS, suggesting dependence on the time of FCS addition to LPS‐stimulated cells. No significant difference was observed in the expression of CD14 on WEHI‐3 cells cultured in the presence and absence of serum, suggesting that CD14 is not involved in the serum‐mediated suppression of these LPS‐responses. On the contrary, FCS showed enhancing effects on the production of NO and TNF‐α by WEHI‐3 cells stimulated with low concentrations (< 100 ng/mL) of S LPS and rough mutant Salmonella minnesota Re LPS. These results suggest that the ability of FCS to suppress LPS‐induced activation of WEHI‐3 cells is mainly dependent on the structure of polysaccharide chains and also on the concentration of LPS employed.
The discovery of T cell help for B cell antibody formation: A perspective from the 30th anniversary of this discovery
Authors: Janeway Charles A
Published: March 2003

Thirty years ago, Miller and Mitchell described the bone‐marrow origin of antibody‐forming cells and the thymic origin of the help needed to activate the bone‐marrow‐derived antibody formation. Since then, there has been a continuous stream of discovery in Australia, from Zinkernagel and Doherty's description of MHC‐restricted antigen recognition to Goodnow's dissection of the maturation and tolerization of antigen‐specific B cells. All of these discoveries, and many more described in the text, contribute to the modern synthesis in immunology.
Modulation of immune function by a modified bovine whey protein concentrate
Authors: Cross Martin L , Gill Harsharnjit S
Published: March 2003

The commercial preparation of dairy foodstuffs generates large volumes of by‐products, many of which have as yet undocumented effects on mammalian immune function. In the present report, a modified whey protein concentrate (mWPC), derived as a by‐product from the commercial manufacture of cheese, was tested for its ability to modulate murine immune functionin vitro. The mWPC suppressed T and B lymphocyte proliferative responses to mitogens in a dose‐dependent fashion. The mWPC also suppressed alloantigen‐induced lymphocyte proliferation during a mixed leucocyte reaction, but showed no suppressive effect against IL‐2‐sustained proliferation of mitogen‐activated T cell blasts. Other indices of lymphocyte activation, such as cytokine secretion and the formation of activated (CD25+) T cell blasts, were suppressed by the mWPC, suggesting that the mode of suppression may be to inhibit the lymphocyte activation process. Enzymatic digestion by pepsin and pancreatin, under physiologically realistic conditionsin vitro, ablated the immunomodulatory function of the mWPC. These results are discussed in relation to the potential development of complex‐mixture dairy products into health‐modulating products.
Haemopoiesis in mice genetically lacking granulocyte–macrophage colony stimulating factor during chronic infection with Mycobacterium avium
Authors: Zhan Y , Cheers C
Published: March 2003

In order to test the role of granulocyte–macrophage colony stimulating factor (GM‐CSF) in haemopoiesis during chronic infection, mice with a targeted disruption of the gene for GM‐CSF were infected intraperitoneally with the facultative intracellular pathogen, Mycobacterium avium. The bacteria spread to lungs, liver and spleen and persisted for more than 10 weeks at levels between 105 and 106 CFU. Bacterial numbers did not differ significantly between infected GM‐CSF–/– and wild‐type mice, making this an excellent model in which to study the effects of GM‐CSF deficiency on haemopoietic cells without complications of interpretation relating to differences in bacterial load. Haemopoietic colony forming cells (CFC) in the bone marrow of GM‐CSF–/– mice before infection were not different from wild‐type. However, whereas CFC in wild‐type mice increased 1.5‐fold with infection, GM‐CSF–/– mice were unable to increase their CFC and numbers were significantly lower than in infected wild‐type mice. Cells attracted to the peritoneal cavity of the GM‐CSF–/– mice following i.p. injection of bacteria were notably lacking in the large, granular macrophages of activated appearance, which were a feature in wild‐type mice. Nitric oxide production by peritoneal cells from GM‐CSF–/– mice was deficient. Thus, GM‐CSF is not critical for haemopoiesis during chronic infection, but in its absence the mice are unable to increase their output of haemopoietic cells and there are deficiencies in macrophage activation.
Do T cells care about the mitogen‐activated protein kinase signalling pathways?
Authors: Rincón Mercedes , Conze Dietrich , Weiss Linda , Diehl Nicole L , Fortner Karen A , Yang Derek , Flavell Richard A , Enslen Hervè , Whitmarsh Alan , Davis Roger J
Published: March 2003

Mitogen‐activated protein (MAP) kinases, which include the extracellular response kinases, p38 and c‐Jun amino terminal kinases (JNK), play a significant role in mediating signals triggered by cytokines, growth factors and environmental stress. The JNK and p38 MAP kinases have been involved in growth, differentiation and cell death in different cell types. In the present paper, we describe how the JNK and p38 MAP kinase signalling pathways are regulated and their role during thymocyte development and the activation and differentiation of T cells in the peripheral immune system. The results from these studies demonstrate that the JNK and p38 MAP kinase signalling pathways regulate different aspects of T‐cell mediated immune responses.
Modelling of peripheral lymphocyte migration: System identification approach
Authors: Srikusalanukul Wichat , De Bruyne Franky , McCullagh Peter
Published: March 2003

This is the first application of the prediction error method (PEM) of system identification to modelling lymphocyte migration through peripheral lymphoid tissue. The PEM was applied to the emergence of labelled lymphocytes from the efferent lymphatic of a lymph node following their intravenous administration. Advantages of PEM included the capacity to calculate the response to a unit impulse stimulus, unavailable to direct observation, and to allow for the return to the node of labelled cells that had already recirculated once. Calculation of the system delay (time between introduction of cells into the blood and their first appearance in lymph) indicated 4.67 ± 1.05 h for the total lymphocyte population. The peak in efferent lymph occurred at 11.91 ± 4.68 h, much earlier than previous reports, which were affected by cells that had already recirculated. While 75% of labelled cells had emerged in efferent lymph by 20.77 ± 5.62 h, 86.38 ± 29.44 h was required for 100% emergence. The considerable heterogeneity in migratory behaviour is likely to reflect frequency and duration of binding of lymphocytes by dendritic cells in paracortical cord corridors. It is proposed that differences in the speed with which lymphocytes pass along corridors depend on their functional status, in particular whether they are naïve or memory cells.
Insulin induces epidermal growth factor (EGF) receptor clustering and potentiates EGF‐stimulated DNA synthesis in Swiss 3T3 cells: A mechanism for costimulation in mitogenic synergy
Authors: Crouch Michael F , Davy Deborah A , Willard Francis S , Berven Leise A
Published: March 2003

In many cellular systems, activation with more than one ligand can produce a cellular response that is greater than the sum of the individual responses to the ligands. This synergy is sometimes referred to as coactivation. In Swiss 3T3 fibroblasts, activation of the epidermal growth factor (EGF) receptor produces a weak induction of DNA synthesis. Insulin has no stimulatory effect on this response. However, in combination, EGF and insulin synergize to cause a large induction of S phase. The underlying cellular biochemistry of this effect has been examined. The data indicate that phospholipase C activation is a major component of agonist‐induced DNA synthesis. In contrast, activation of p70 S6 kinase by single agonists was inversely related to their ability to stimulate DNA synthesis. Therefore, it was examined whether stimulation of Swiss 3T3 cells with insulin causes changes in the subcellular distribution of EGF receptors and phospholipase Cγ1 that could potentially explain the observed synergy or costimulation. It was found that insulin effectively induced the accumulation of EGF receptors on the actin arc of cells without activation of the EGF receptor. In contrast, EGF, when added for several hours, did not cause accumulation of the EGF receptor at this site. However, both EGF and insulin stimulated the accumulation of phospholipase Cγ1 at the actin arc, which was coincident with the EGF receptor in the case of insulin‐ stimulated cells. Therefore, it is suggested that the insulin‐induced coclustering of the EGF receptor with phospholipase Cγ1 at the actin arc may allow for greater efficiency of signal transduction, resulting in the synergy observed for these two hormones in stimulation of DNA synthesis.
Role of exhaled nitric oxide in asthma
Authors: Yates Deborah H
Published: March 2003

Nitric oxide (NO), an evanescent atmospheric gas, has recently been discovered to be an important biological mediator in animals and humans. Nitric oxide plays a key role within the lung in the modulation of a wide variety of functions including pulmonary vascular tone, nonadrenergic non‐cholinergic (NANC) transmission and modification of the inflammatory response. Asthma is characterized by chronic airway inflammation and increased synthesis of NO and other highly reactive and toxic substances (reactive oxygen species). Pro‐ inflammatory cytokines such as TNFα and IL‐1β are secreted in asthma and result in inflammatory cell recruitment, but also induce calcium‐ and calmodulin‐independent nitric oxide synthases (iNOS) and perpetuate the inflammatory response within the airways. Nitric oxide is released by several pulmonary cells including epithelial cells, eosinophils and macrophages, and NO has been shown to be increased in conditions associated with airway inflammation, such as asthma and viral infections. Nitric oxide can be measured in the expired air of several species, and exhaled NO can now be rapidly and easily measured by the use of chemiluminescence analysers in humans. Exhaled NO is increased in steroid‐naive asthmatic subjects and during an asthma exacerbation, although it returns to baseline levels with appropriate anti‐inflammatory treatment, and such measurements have been proposed as a simple non‐invasive method of measuring airway inflammation in asthma. Here the chemical and biological properties of NO are briefly discussed, followed by a summary of the methodological considerations relevant to the measurement of exhaled NO and its role in lung diseases including asthma. The origin of exhaled NO is considered, and brief mention made of other potential markers of airway inflammation or oxidant stress in exhaled breath.
In vitro and in vivo expression of a nephritogenic Ig heavy chain determinant: Pathogenic autoreactivity requires permissive light chains
Authors: Cooperstone Brenda G , Rahman Mohammed M , Rudolph Earl H , Foster Mary H
Published: March 2003

Lymphocyte antigen receptors are promising targets for immune intervention strategies in disorders marked by repertoire skewing or expansion of lymphocyte subsets. Appropriate application of immune receptor modulation is predicated on understanding the role of a particular receptor in pathogenesis and disease regulation. The VHB/W16 gene, restricted to mice carrying the j haplotype for the J558 family, is overexpressed by murine lupus anti‐DNA Ig. This gene is also expressed recurrently among nephritogenic anti‐DNA Ig recovered from several autoimmune strains, suggesting that cells expressing this pathogenic receptor are positively selected during disease progression. To explore the extent and mechanisms by which Ig H chains expressing this gene contribute to autoimmunity, an Ig H chain gene was engineered for in vitro and in vivo recombination studies. Site‐directed mutagenesis generated unique restriction sites to link PCR‐amplified V region (VDJ) cDNA to previously isolated genomic fragments containing Ig regulatory and signal sequences. The new 3 kb VDJ gene was then ligated to a 9 kb fragment encoding the IgM constant region. Transfection of H chain loss variant myeloma with the complete 12 kb construct, termed 238H‐Cμ, resulted in secretion of intact Ig pairing 238H‐Cμ with a lambda L chain; however, transfectant Ig lacked autoreactivity and pathogenicity. Introduction of the 238H‐Cμ H chain as a transgene onto the non‐autoimmune C57BL/6 background resulted in abundant B cell surface expression of 238H‐Cμ, however, four transgenic Ig recovered by fusion of LPS‐stimulated splenocytes and formed by combination of 238H‐Cμ with endogenous kappa chains do not bind DNA or laminin. These results indicate that the antigen binding sites encoded by this disease‐associated gene and/or H chain must associate with permissive L chains to specify autoimmunity. The 238H‐Cμ transgenic model should prove useful in dissecting the in vivo fate of 238H‐Cμ‐L combinations that produce pathogenic autoreactive receptors and in evaluating receptor‐targeted interventions.
Recruitment of lymphocytes to the human liver
Authors: Lalor Patricia F , Shields Philip , Grant Allister J , Adams David H
Published: March 2003

This review discusses the function and localisation of lymphocytes resident within the human liver, under both physiological and pathological conditions. Through description of the mechanisms that mediate lymphocyte recruitment into tissues, this article explains how hepatic endothelial and epithelial cells regulate the recruitment of specific lymphocyte subpopulations. We illustrate that the expression of adhesion molecules and chemokines is crucial to the control of lymphocyte adhesion. Thus, in the normal liver, adhesion molecules such as vascular adhesion protein‐1 (VAP‐1), intercellular adhesion molecule‐1 (ICAM‐1) and intercellular adhesion molecule‐2 (ICAM‐2), and chemokines such as regulated on activation, normal T cell expressed and secreted (RANTES), monocyte chemoattractant protein‐1 (MCP‐1), macrophage inflammatory protein‐1α (MIP‐1α), interferon γ inducible protein‐10 (IP‐10), MIG and interferon inducible T‐cell alpha chemoattractant (ITAC) are involved in lymphocyte binding to different endothelial compartments. However, in response to inflammation or injury, additional expression of adhesion molecules such as VCAM‐1, p‐selectin and e‐selectin, as well as higher levels of chemokines, permits the attraction and retention of specific effector populations of lymphocytes. We also discuss the expression and function of a newly defined adhesion protein, (VAP‐1), and suggest that the unique functions of this protein may provide therapeutic potential for the treatment of liver disease.
Competent dendritic cells derived from CD34+ progenitors express CMRF‐44 antigen early in the differentiation pathway
Authors: Monji Tatsue , Petersons Jerilyn Tynes , Saund Narinder K , Vuckovic Slavica , Hart Derek Nigel John , Auditore‐Hargreaves Karen , Risdon Grant
Published: March 2003

Differentiation of CD34+ haematopoietic stem cells into functional dendritic cells (DC) was investigated using the mAb CMRF‐44 and other mAb against DC‐associated markers. GM‐CSF mobilized peripheral blood stem cells were obtained from healthy donors by leukapheresis. CD34+ cells were purified using CD34+‐positive selection, and subsequent immunomagnetic depletion of CD14 and CD2 cells. CD34+ cells were cultured in medium supplemented with one or more of GM‐CSF, TNF‐α, IL‐4 or IL‐6. CMRF‐44 Ag expression was monitored by flow cytometry, and DC function by allogeneic MLR and tetanus toxoid (TT) presentation assays. CD34+ cells quickly acquired the CMRF‐44 Ag when cultured in the presence of TNF‐α. By day 3, more than 50% of the cells were double‐positive for CD34 and CMRF‐44. CD34 expression was gradually lost, so that by day 9, the majority of the cells were CD34‐/CMRF‐44+. GM‐CSF and TNF‐α also induced CD40 expression, and up‐regulation of CD54 and MHC class II on CD34+ cells; their expression was correlated to the CMRF‐44 Ag. Day 3 CD34+/CMRF‐44+ cells, but not CD34+/CMRF‐44‐ cells, become potent APC when cultured further with GM‐CSF plus TNF‐α. These CMRF‐44+ cells were potent inducers of Th1‐type immune response in the primary allogeneic MLR and present TT to autologous CD4+ T cells. TNF‐α alone is sufficient to induce CMRF‐44 expression on CD34+ cells, but in combination with GM‐CSF expands the CMRF‐44+ population. CMRF‐44 expression correlates with DC function and may be a useful early marker for commitment of CD34+ cells to the DC differentiation pathway.
Maturation of dendritic cells with lipopeptides that represent vaccine candidates for hepatitis C virus
Authors: Chua Brendon Y , Healy Anne , Cameron Paul U , Stock Owen , Rizkalla Michael , Zeng Weiguang , Torresi Joseph , Brown Lorena E , Fowler Nina L , Gowans Eric J , Jackson David C
Published: March 2003

The ability of antigens to elicit immune responses depends upon their initial recognition, uptake, processing and presentation by dendritic cells. This fact has been recognized by many workers and dendritic cells are now regarded as natural ‘adjuvants’ in the business of vaccine design. One way of persuading dendritic cells to become interested in foreign material is to decorate it with lipid moieties found in bacteria. This approach has been used in the context of synthetic peptide‐based immunogens and depending on the nature of the epitopes included, can provide highly immunogenic structures capable of eliciting antibody or cytotoxic T cell responses. In this paper we describe the results of experiments in which the stimulatory effects of peptide‐based vaccine candidates on human dendritic cells are examined. Our findings indicate that lipidated structures comprising vaccine target sequences of viral origin coupled to the synthetic lipid groups of bacteria are able to induce the maturation of dendritic cells, as measured by the expression of cell surface MHC class II molecules.
Priority areas for clinical research in palliative care nursing
Authors: Chang Esther , Daly John
Published: March 2003

Priority areas for clinical research in palliative care nursing

This report highlights a number of current research issues and concerns in palliative care nursing. The aim of the study was to identify high clinical nursing research priorities in palliative care, drawing on the expertise of nine (n=9) clinical nurse consultants currently working in this specialty. The Delphi method was used to collect and process data in the study. Thirteen high research priorities emerged which have relevance for nursing practice, patient and family care in the hospice and community care setting. In the context of this study, the concept of high priority relates to research participant consensus on the most pressing nursing research problems which require investigation to improve clinical practice. Study findings provide direction for clinical research and continuing education in palliative care which may benefit expert nurses and their patients.
Selected factors influencing self‐concept among hospitalized Chinese school‐age children with a chronic illness
Authors: Yan Hu , Kantawang Seepan , Yinghua Yang
Published: March 2003

A correlational descriptive study was conducted to investigate self‐concept and selected influencing factors among hospitalized Chinese school‐age children with a chronic illness. The purposive sample was composed of 122 school‐age children with chronic illnesses, such as nephrotic syndrome, leukemia, and congenital heart disease, who were admitted to three major teaching hospitals in Shanghai City. The children’s medical records, demographic forms, and the Piers‐Harris Self‐concept Scale (PHSCS) were used to collect the data. Descriptive statistics, and stepwise multiple regression were used to analyze the data utilizing the SPSS program (SPSS Inc, Chicago, IL, USA). The results of this study showed that the majority of hospitalized Chinese school‐age children with a chronic illness had at least an average level of self‐concept. Academic achievement (grade point average) was a strong predictor of self‐concept, as are most of its subconcepts, including social behavior, academic competence, and physical appearance and attributes. Age was a significant predictor of overall self‐concept, social behavior, and popularity subconcept. Sex was a significant predictor of self‐concept subconcepts such as social behavior, anxiety, and popularity. Duration of illness was a significant predictor of physical appearance and attributes. In addition, the type of illness was a significant predictor of popularity. It can be concluded that the importance of school education should be emphasized by hospital and school nurses for the purpose of helping such children build a positive self‐concept concerning their age, sex, academic achievement, type of illness, and duration of illness. Recommendations for further research have been suggested.
The medical model and other constructions of self‐neglect
Authors: Lauder William
Published: March 2003

Nurses frequently encounter patients who neglect their personal hygiene and household cleanliness. Self‐neglect is usually understood within the parameters of the medical model, with its need to objectify and categorize. The medicalization of self‐neglect obscures the fact that patients and professionals may have different ideas about what self‐neglect is and what it is not. This paper explores how the medical construction of self‐neglect has come to dominate the self‐neglect discourse and will also explore other possible ways of understanding self‐neglect.
Development of nursing research in Germany in the European context
Authors: Rn Mathilde Hackmann , (fh) Diplom‐Pflegepädagogin
Published: March 2003

The development of nursing research in Germany is described in this article; in the first part, the evolution of nursing research in Europe is discussed briefly, then the development of nursing research in Germany is analysed using the framework of the main stages of the development of nursing research described by Tierney. A comparison of the differences between European and German development follows. Reasons for the differences are briefly analysed and discussed in the context of the German political and social background.
Teaching palliative care principles to UK nursing home care assistants
Authors: Dowding Chris , Homer Pam
Published: March 2003

This paper describes the initiatives that led to a study day for Health Care Assistants in the UK, focusing on the principles and practice of palliative care for practitioners. Topics covered were ‘What is palliative care?’, ‘How can you help patients with pain’, ‘Needs of the dying patient’, ‘I don’t know what to say’, ‘Answering awkward questions’, and ‘Ways of relieving distressing symptoms’. Participants valued the study day and feedback showed that the Health Care Assistants, essentially assistants to qualified nursing staff with minimal or no training themselves, had many vocational and emotional needs that were not being met.
Developing benchmark inventories to assess the content of telephone consultations in accident and emergency departments: Use of the Delphi technique
Authors: Crouch Robert , Dale Jeremy , Crow Rosemary
Published: March 2003

The provision of telephone advice to members of the general public from staff based in accident and emergency departments is common practice. However, it is largely conducted on an ad hoc basis without the use of formal guidelines or decision support. The evidence base from which to derive guidelines for the telephone assessment and advice of many common conditions is lacking. This study, using the Delphi technique, was undertaken to develop a number of benchmarks for use as objective measures against which the comprehensiveness of telephone assessments could be tested. Consensus views on the essential and desirable items to be considered for each of 10 presenting complaints was achieved. It is argued that establishing consensus views on clinical topics provides an effective means of developing an evidence base where other sources of evidence are lacking.