bluuebunny/crossref_metadata_2025 huggingface dataset:
INHIBITION OF CALCIUM‐INDEPENDENT LUMINAL UPTAKE OF L‐DOPA BY CALMODULIN ANTAGONISTS IN IMMORTALIZED RAT CAPILLARY CEREBRAL ENDOTHELIAL CELLS
Authors: Sampaio‐Maia B. , Soares‐Da‐Silva P.
Published: September 2002

The present study examined the involvement of protein kinase A (PKA), protein kinase G (PKG), protein kinase C (PKC), protein tyrosine kinase (PTK) and Ca2+/calmodulin mediated pathways on the luminal uptake of L‐DOPA through the L‐type amino acid transporter in immortalized rat capillary cerebral endothelial (REB‐4) cells. Non‐linear analysis of the saturation curve for L‐DOPA revealed a Kmvalue (in μM) of 71±9 and a Vmaxvalue of 17±1 (in nmol mg protein/6min). L‐DOPA uptake at the luminal cell border was a sodium‐independent process and insensitive to N‐(methylamino)‐isobutyric acid (MeAIB, 1m m), but sensitive to 2‐aminobicyclo(2,2,1)‐heptane‐2‐carboxylic acid (BHC, IC50=140μm). The Ca2+/calmodulin inhibitors calmidazolium and trifluoperazine inhibited L‐DOPA (2.5μm) uptake with IC50s of 23 and 33μm, respectively. The inhibitory effect of BHC on the accumulation of L‐DOPA was of the competitive type, whereas that of calmidazolium and trifluoperazine was of the non‐competitive type. Modulators of PKA (cyclic AMP, forskolin, isobutylmethylxanthine and cholera toxin), PKG (cyclic GMP, zaprinast, LY 83583 and sodium nitroprusside), PKC (phorbol 12,13‐dibutyrate, staurosporine and chelerythrine) and PTK (genistein and tyrphostin 25) failed to affect the accumulation of a non‐saturating (2.5μm) concentration of L‐DOPA. It is concluded that L‐DOPA uptake in RBE‐4 cells is promoted through the L‐type amino acid transporter and appears to be under the control of calmodulin mediated pathways.
MEASUREMENT OF FIBROBLAST AND BACTERIAL DETACHMENT FROM BIOMATERIALS USING JET IMPINGEMENT
Authors: Bundy K. J. , Harris L. G. , Rahn B. A. , Richards R. G.
Published: September 2002

Fibroblast and Staphylococcus aureus detachment strength from orthopaedic alloys and a tissue culture plastic (Thermanox) have been investigated with jet impingement. For S. aureus, unlike fibroblasts, detachment is caused more by pressure than shear. For these biomaterials, detachment strength is much higher for S. aureus than fibroblasts. Comparing materials under equivalent flow conditions, S. aureus attach to stainless steel and titanium with equal strength and more strongly than to Thermanox. For fibroblasts, detachment strength from all materials was similar. Fibroblast detachment strength from these biomaterials substantially decreases with time at equal flow rates and increases with flow rate at equal exposure times. Detachment strength is very similar for 3T3 and L929 fibroblasts on Thermanox for equivalent flow rate/time combinations, though enhanced adhesion of 3T3 cells was often noted for metals. Time effects are less evident for S. aureus. S. aureus adhesion to metals is more affected by flow rate than fibroblast adhesion.
LOCALIZATION OF THE GLUT1 GLUCOSE TRANSPORTER TO BREFELDIN A‐SENSITIVE VESICLES OF DIFFERENTIATED CIT3MOUSE MAMMARY EPITHELIAL CELLS
Authors: Haney Peter M.
Published: September 2002

Glucose is a precursor of lactose, the major carbohydrate and osmotic constituent of human milk, which is synthesized in the Golgi. The GLUT1 glucose transporter is the only glucose transporter isoform expressed in the mammary gland. The hypothesis that lactogenic hormones induce GLUT1 and cause its localization to the Golgi of mammary epithelial cells was tested in CIT3mouse mammary epithelial cells. Treatment with prolactin and hydrocortisone caused a 15‐fold induction of GLUT1 by Western blotting, but 2‐deoxyglucose uptake decreased. Subcellular fractionation and density gradient centrifugation demonstrated enrichment of Golgi fractions with GLUT1. Lactogenic hormones enhanced GLUT1 glycosylation, but did not determine whether GLUT1 was targeted to plasma membrane or to Golgi. Confocal microscopy revealed that lactogenic hormones alter GLUT1 targeting from a plasma membrane pattern to a predominant perinuclear distribution with punctate scattering through the cytoplasm. GLUT1 is targeted to a compartment which is more sensitive to Brefeldin A than the compartments in which GM130 and β‐COP reside. Targeting of GLUT1 to endosomes was specifically excluded. We conclude that prolactin and hydrocortisone induce GLUT1, enhance GLUT1 glycosylation, and cause glycosylation‐independent targeting of GLUT1 to Brefeldin A‐sensitive vesicles which may represent a subcompartment of cis‐Golgi. These results demonstrate a hormonally‐regulated targeting mechanism for GLUT1 and are consistent with an important role for GLUT1 in the provision of substrate for lactose synthesis.
REDUCED EXPRESSION OF THE BRCA1 GENE AND INCREASED CHROMOSOMAL INSTABILITY IN MCF‐7 CELL LINE
Authors: Kachhap S. K. , Vetale S. P. , Dange P. , Ghosh S. N.
Published: September 2002

Using clonal cell cultures, a significant increase in chromosomal aberrations (aneuplolidy, dicentrics and chromatid breaks) were observed in MCF‐7 cells compared with HeLa. BRCA1 expression was lower in MCF‐7 cells than in HeLa cells. Since BRCA1 is known to play a role in the maintenance of chromosomal integrity, the increase in chromosomal aberrations in MCF‐7 clones suggests that downregulation of BRCA1 expression could be one of the possible mechanisms for increased chromosomal instability in this cell line.
TRANSLOCATION OF THE IL‐1 RECEPTOR TO FOCAL ADHESIONS IS REGULATED THROUGH THE C‐TERMINAL END OF THE CYTOPLASMIC DOMAIN
Authors: Huang W‐Y. , Vallés S. , Qwarnstrom E. E.
Published: September 2002

The mechanisms of translocation of the IL‐1 receptor to focal adhesions were analysed using EGFP reporter constructs and confocal microscopy. In fibronectin‐attached cells, the receptor fusion protein was present in distinct punctate areas, co‐localizing with the transmembrane‐linkage protein vinculin. In migrating cells, the two proteins co‐localized at the leading edge in ruffle‐like structures. Experiments using a series of receptor mutants revealed that translocation of the IL‐1 receptor to focal adhesions was dependent on motifs conserved between members of the TIR family, in the C‐terminal end of the receptor. Further, an enhanced level of expression of the wild‐type receptor at attachment sites was shown to correlate with an increased severity of IL‐1 induced structural effects. This report demonstrates that translocation of the IL‐1 receptor to focal adhesions is dependent on conserved domains in the C‐terminal end of the protein, and that receptor localization at these sites is important in structural regulation of IL‐1 mediated responses.
SV‐40 LARGE T ANTIGEN REVERSIBLY INHIBITS EXPRESSION OF TYROSINASE, TRP‐1, TRP‐2 AND MITF, BUT NOT PAX‐3, IN CONDITIONALLY IMMORTALIZED MOUSE MELANOCYTES
Authors: Prince Sharon , Illing Nicola , Kidson Susan H.
Published: September 2002

Transformation of mouse melanocytes with a variety of exogenous oncogenes or chemical carcinogens frequently results in irreversible loss of pigmentation. We have infected mouse melanocytes with a temperature‐sensitive mutant of the simian virus 40 (SV40) large tumour antigen to study the molecular mechanisms underlying depigmentation during melanocyte transformation. The results show that, out of six cell lines analyzed at the permissive temperature of the oncoprotein, three epidermal and two dermal melanocyte clones remained pigmented and retained the ability to synthesize melanin and to express the melanocyte‐specific genes, including tyrosinase, tyrosinase related protein‐1, tyrosinase related protein‐2 andMitf. In contrast, one dermal melanocyte clone (DMEL‐3) gradually depigmented. This depigmentation was characterized by enhanced growth and down‐regulation of melanocyte‐specific gene expression. When the oncogene was inactivated by culture at the non‐permissive temperature, the pigmented phenotype in DMEL‐3 cells could be rescued, and there was a corresponding time‐dependent increase in melanocyte‐specific gene expression. After extended passage, this rescue could not be achieved. Our results provide direct evidence for the role of the SV40 large T antigen in melanocyte de‐differentiation. Expression of Pax‐3, a transcription factor implicated in melanocyte differentiation, was unaltered during the SV40‐initiated de‐differentiation, and de‐differentiated melanocytes expressed normal levels of Pax‐3 message. We speculate on the mechanism by which the oncoprotein might be regulatingMitf gene expression and of the role of Pax‐3 in this process.
EFFECT OF STEROID HORMONES ON MEMBRANE PROFILES OF HELA S3 CELLS
Authors: Sommer P. , Cowley H. M.
Published: September 2002

The cervical carcinoma cell line, HeLa S3, was exposed to oestradiol and progesterone separately and combined in ratios similar to those of the luteal and follicular phases of the menstrual cycle. After 48h of exposure, membrane proteins were extracted from the plasma membrane and analyzed. The lipid composition of the cells and lectin binding patterns to the cells were also assessed. The hormones had a profound effect on the HeLa S3 membrane protein profiles. Progesterone inhibited the synthesis of a wide variety of proteins while oestradiol negated this effect. Less variation between lipid profiles was noted although progesterone reduced the amount of cholesterol present. Differences in lectin binding profiles between the various treatments were noted, indicating an hormonal effect on glycosylation. Such hormonal effects on membrane composition may have implications in cervical susceptibly to microbial infections.
Al3+ AND Zn2+‐INDUCED STRUCTURAL CHANGES AND LOCALIZATION IN A FULLY‐HYDRATED LIVE EUKARYOTIC CELLULAR MODEL
Authors: Wendt‐Larsen Jette , Abraham‐Peskir Joanna V. , Medenwaldt Robin
Published: September 2002

This study combined techniques that did not require preparation protocols that were potentially harmful to the cell, making it possible to investigate cells at, or close to, their natural physiological state. We used the freshwater protozoon Chilomonas paramecium as a eukaryotic cellular model to locate sites of Al3+or Zn2+accumulation and quantify the associated structural changes. Cells were fully hydrated throughout the study, which used a combination of differential interference contrast light microscopy, confocal laser scanning microscopy and transmission X‐ray microscopy. The latter technique allowed high resolution (50nm) and high contrast imaging of live cells in solution. For confocal laser scanning microscopy the relatively new fluorochrome Newport Green was used. This made fluorescent complexes with intracellular Al3+and Zn2+, allowing localisation of metal‐containing granules and vesicles. After long term exposure a previously unreported annular‐shaped site of metal accumulation was found, signifying a vesicle with metal accumulated in the periphery only. After exposure to Al3+and Zn2+, the cell pellicle was thinner and the majority of rounded‐up cells had a concentric layering of organelles. By combining a variety of techniques it was possible to gain high resolution structural and chemical information on cells minimally exposed to potentially artefact‐inducing procedures.
HYDROSTATIC PRESSURE INDUCED CHANGES IN THE CYTOARCHITECTURE OF PHEOCHROMOCYTOMA (PC‐12) CELLS
Authors: Wilson Ronald G. , Trogadis Judy E. , Zimmerman Selma , Zimmerman Arthur M.
Published: September 2002

Confocal microscopy, in association with three‐dimensional reconstruction, revealed that microtubules and microfilaments in differentiating PC‐12 cells were disrupted in a dose‐dependent manner following pressure treatment. Hydrostatic pressure caused cell rounding, microtubule and microfilament disorganization, neurite retraction and the formation of a microtubule ring adjacent to the cell surface. Volume analysis from computer‐generated reconstructed cells, at atmospheric pressure, showed that the apparent volume of microtubules and microfilaments, normalized to 100 units, was 22 and 11 respectively. At 4000 and 8000psi, the apparent microtubule volume was reduced to 16 and 12 units, respectively, and the apparent microfilament volume was reduced to 8 and 5 units, respectively. Thus, the apparent microtubule and microfilament volumes in PC‐12 cells decreased as pressure increased. In the presence of taxol and phalloidin which stabilize the cytoarchitecture, cells resist the effects of hydrostatic pressure. In the presence of colchicine and cytochalasin D compounds which destabilize the cytoarchitecture, cells are more susceptible to the disrupting effects of hydrostatic pressure. The effects of hydrostatic pressure on cell morphology were reversible.
CYTOSTATIC EFFECT OF INOSTAMYCIN, AN INHIBITOR OF CYTIDINE 5′‐DIPHOSPHATE 1,2‐DIACYL‐sn‐GLYCEROL (CDP‐DG): INOSITOL TRANSFERASE, ON ORAL SQUAMOUS CELL CARCINOMA CELL LINES
Authors: Baba Yuh , Tsukuda Mamoru , Mochimatsu Izumi , Furukawa Shigeru , Kagata Hiroko , Nagashima Yoji , Koshika Shinri , Imoto Masaya , Kato Yasumasa
Published: September 2002

Inostamycin, which was recently isolated from Streptomyces sp. MH816‐AF15 as an inhibitor of cytidine 5′‐diphosphate 1,2‐diacyl‐sn‐glycerol (CDP‐DG): inositol transferase, caused a G1‐phase accumulation in the cell cycle of small cell lung carcinomas. To investigate whether the cytostatic effect of inostamycin is restricted to lung carcinoma cell lines or applicable to other type of cells, we tested five oral squamous cell carcinoma (SCC) cell lines. Cell growth was suppressed in 62.5–125ng/ml inostamycin in the culture medium in all oral cancer cell lines tested, with non‐viable cells being <1%, indicating inostamycin is cytostatic on SCC cell lines. Decrease in cyclin D1 mRNA and protein expression due to the inostamycin treatment was accompanied by suppression of phosphorylated retinoblastoma susceptibility gene product (pRB‐P) levels. Moreover, flow cytometric analysis showed that inostamycin induced an increase in G1/G0 cells (1.2–3.2 fold) over 24h. These results suggest that inostamycin is a useful agent for tumour dormant cytostatic therapy for oral SCC.
APOPTOTIC AND MITOTIC ACTIVITY IN SQUAMOUS CELL CARCINOMA CELLS AFTER COMBINED MODALITY TREATMENT WITH γ‐IRRADIATION AND DIBROMODULCITOL
Authors: Kraxner H. , Tamás L. , Sáfrány G. , Ribári O. , Oláh I. , Hidvégi E. , Répássy G. , Szende B.
Published: September 2002

A‐431 squamous cell carcinoma cells were treated in vitro with either 4Gy radiatio of 15 (or 45) μg/ml dibromodulcitol (DBD), as well as with combined 4Gy irradiation and DBD, with the latter as either a pretreatment or post‐treatment. DBD alone or in combination with radiation had a greater effect on cell proliferation than the effect of radiation alone. The difference is due to a higher level of apoptosis induced by DBD, especially in conjunction with radiation. Such a combination may therefore be useful in the treatment of squamous cell carcinoma, which in general responds poorly to radiation therapy.
POTASSIUM CONCENTRATION IS REDUCED IN CULTURED RABBIT TRACHEAL SMOOTH MUSCLE CELLS AFTER WITHDRAWAL OF SERUM
Authors: Warley Alice
Published: September 2002

Comparison of elemental concentrations in growth‐arrested airway smooth muscle cells with those in their proliferating counterpart showed that potassium (K+) was significantly reduced, whereas concentrations of other elements sodium (Na+), magnesium (Mg2+), phosphorus (P), and chlorine (Cl−) remained unchanged. Reduced K+concentration was associated with a change in the cells from a spindle shape to a flattened form.
HEPATIC REGENERATION INDUCES TRANSIENT ACUTE PHASE REACTION: SYSTEMIC ELEVATION OF ACUTE PHASE REACTANTS AND SOLUBLE CYTOKINE RECEPTORS
Authors: Fulop Andras Kristof , Pocsik Eva , Brozik Marta , Karabelyos Csaba , Kiss Arpad , Novak Istvan , Szalai Csaba , Dobozy Otto , Falus Andras
Published: September 2002

The growth factors present during liver regeneration partially overlap with the regulators of the hepatic acute phase response. We analysed the acute phase reaction and changes in soluble cytokine receptors after partial hepatectomy, when tissue injury inducing acute phase reaction and major reduction of liver mass occur simultaneously. Three acute phase proteins and mRNAs were determined by ELISA and northern blot hybridisation in rats. Serum levels of IL‐6 and three soluble cytokine receptors (sTNF‐αR I and II, sIL‐6R) were detected by ELIBA or dot‐blot assay. Time‐course profiles of fibrinogen, α2‐macroglobulin and haptoglobin proteins and mRNA are presented. Elevation of IL‐6, soluble TNF‐α receptors and soluble IL‐6 receptor levels were also detected. The time‐course of changes in haptoglobin concentration and elevation of soluble cytokine receptors is described by this in vivo experimental system. The results show good correlation with (post)transcriptional activation of immediate and delayed early gene products. These data suggest the involvement of both acute phase proteins and soluble cytokine receptors in the regulation of liver regeneration.
PIGPEN AND ENDOTHELIAL CELL DIFFERENTIATION
Authors: Alliegro Mark C.
Published: September 2002

Endothelial cells can toggle back and forth between differentiated and relatively undifferentiated states with comparative ease. This is an important characteristic, particularly in adult tissues where the constitutive endothelial cell phenotype is quiescent. It enables rapid repair of wounds, renewal of the vascular intima in parts of the circulatory system with high flow and turbulence, and is essential to the cyclic function of reproductive organs. However, the ability to dedifferentiate can be a severe disadvantage when it is subverted to the support of disease processes such as tumor growth and metastasis. The control of endothelial cell differentiation state is, therefore, a matter of significance to investigators of basic developmental mechanism, as well as those studying an array of neovascular disorders. Recently, studies have advanced beyond the identification of extracellular triggers and overt cellular responses to the analysis of signal transduction pathways and nuclear events. This review focuses on the nuclear protein pigpen that is found in the right place at the right time, and with the necessary equipment, to modulate endothelial cell differentiation. We project that when we better understand the relationship of pigpen to its upstream regulators and downstream effectors, we will also have a better understanding of the mechanisms underlying capillary morphogenesis.
IGF‐I‐INDUCED APOPTOSIS IN LM2d6 CULTURED AT A LOW CONCENTRATION OF FETAL BOVINE SERUM
Authors: Seto J. , Seto Y. , Iino M. , Komatsu T. , Katagiri K. , Hagino A. , Aso H. , Katoh K. , Sasaki Y. , Obara Y.
Published: September 2002

We examined the effects of IGF‐I (1–1000ng/ml) on cell proliferation in LM2d6 mouse fibroblast cells at 0.1, 1.0 and 5.0% fetal bovine serum (FBS). In medium containing 0.1% FBS, treatment of LM2d6 cells with IGF‐I significantly reduced the cell number in a dose‐ and time‐dependent manner, whereas no effects were seen at 1 or 5% FBS. Treatment of the cells with 0.1% FBS for 72h caused DNA laddering and nuclear condensation. However, Scatchard analysis for IGF‐I binding sites on the cells revealed that both the number and the affinity of IGF‐I receptors were not greater than that of Balb/3T3 cells. Furthermore, the apoptotic action of Long (R3)‐IGF‐I, an analogue of IGF‐I that has a reduced affinity for IGF binding proteins, was not greater than that of IGF‐I. Taken together, we conclude that IGF‐I reduces cell proliferation at low levels of FBS due to the induction of apoptosis. This effect is probably not caused by an excess production of IGF binding proteins in LM2d6 cells.
EFFECTS OF LEUKAEMIA INHIBITORY FACTOR ON ENDOMETRIAL RECEPTIVITY AND ITS HORMONAL REGULATION IN RABBITS
Authors: Liu C. Q. , Yuan Y. , Wang Z. X.
Published: September 2002

The effects of hormones on production of leukaemia inhibitory factor (LIF) and the uterine receptivity in rabbits were studied. In ovariectomised rabbits, LIF protein was not detected in control but upregulated by progesterone alone. Oestrogen had a slightly negative effect when the rabbits were treated with both oestrogen and progesterone. Mifepristone (Mi) inhibited the progesterone‐stimulated production of LIF in rabbit uterus. The transfer of embryos to LIF‐treated recipients significantly increased pregnancy rate (70%) and implantation rate (27%) as compared with control (pregnancy rate=40% and implantation rate=17%). The transfer of embryos to LIF and mifepristone‐treated recipients significantly decreased pregnancy rate (30%) and implantation rate (9%). The results indicated that LIF protein had a beneficial effect on uterine receptivity and mifepristone prevented this effect.
MORPHOLOGICAL ALTERATION OF PERITONEAL MAST CELLS AND MACROPHAGES IN THE MOUSE PERITONEAL CAVITY DURING THE EARLY PHASES OF AN ALLERGIC INFLAMMATORY REACTION
Authors: Oliani Sonia M. , Lim Lina H. K. , Christian Helen C. , Pell Keith , Das Anuk M. , Perretti Mauro
Published: September 2002

We investigated the presence of mast cell granules in macrophages following an in vivo model of an allergic reaction. Injection of ovalbumin (100μg) into the peritoneal cavity of sensitised mice produced a rapid (within 2h) influx of neutrophils followed by a slower (after >4h) eosinophil migration. Ovalbumin treatment induced a high incidence (∼50%) of mast cell degranulation compared to control phosphated‐buffered saline‐treated mice. The majority (∼90%) of peritoneal macrophages contained mast cell granules as early as 2h post‐ovalbumin, with lower values at later time‐points, as determined by staining with Toluidine blue and Berberine sulphate. This was confirmed by electron microscopy which enabled us to identify the complex mast cell granule sub‐structural components in macrophage phagosomes. In conclusion, we used histochemical and ultrastructural analyses to show that mast cell granules become internalised with macrophages during the early stages of an experimental allergic reaction.
HORMONAL CONTROL OF ENZYME ACTIVITY DURING THE PLASMA MEMBRANE TRANSFORMATION OF UTERINE EPITHELIAL CELLS
Authors: Bucci Maria , Murphy Christopher R.
Published: September 2002

Ultrastructural and light microscopic catalytic histochemical methods were used to study the distribution and changes in distribution of four phosphatase enzymes; alkaline phosphatase, 5′‐nucleotidase, thiamine pyrophosphatase and adenosine triphosphatase in uterine epithelial cells in response to the ovarian hormones, oestrogen, progesterone or a combination of both used in different regimes on ovariectomised rats. Reaction product for all four enzymes was clearly localised in the epithelial cells, especially with oestrogen priming. However, the four enzymes showed markedly different patterns of organisation of reaction product in response to other hormonal treatments.

Our findings clearly show that the expression of these enzymes is under ovarian hormonal control. However, while all of the enzymes are upregulated by oestrogen, the response to progesterone is variable, which can upregulate or downregulate different enzymes. The findings are particularly obvious at the electron microscopic level on the apical plasma membrane of the uterine epithelial cells, which was the main focus of our study.
SUBSTRATE‐INDUCED POLARISATION OF CULTURED EPITHELIOCYTES AND FIBROBLASTS: NON‐REACTIVITY OF RAS‐TRANSFORMED CELLS
Authors: Moizhess Tatjana G. , Vasiliev Jury M.
Published: September 2002

Non‐transformed epitheliocytes and fibroblasts undergo modulations between the less polarised and more polarised phenotypes depending on the nature of the substrate. In contrast, transformed cells express polarised phenotype regardless of the substrate.
DISTRIBUTION AND TRANSCRIPTION ACTIVITY OF NUCLEOLAR DNA IN HIGHER PLANT CELLS
Authors: Tao W. , Xu W. , Valdivia M. M. , Hao S. , Zhai Z. H.
Published: September 2002

By using the NAMA‐Ur DNA selective staining method, we have observed in situ the location of nucleolar DNA in onion cells and found it at the boundary between fibrillar centres (FC) and dense fibrillar component (DFC) in transcriptionally active nucleolus. We have also used anti‐NOR serum, which is identified as the RNA Polymerase I transcription factor (UBF) antibody, to study its reactivity with higher plant cells and demonstrated this factor associated to the DFC but not present at the interior of FC. Finally, by employing anti‐DNA/RNA hybrid antibodies, we labeled the transcriptionally active rRNA genes in active nucleolus and testified that at the boundary between FC and DFC. The results provide the evidence that the boundary between FC and DFC is the genuine transcription site of rRNA genes in nucleolus.
HIGH RESOLUTION SCANNING FORCE MICROSCOPY OF CARDIAC MYOCYTES
Authors: Davis Jason J. , Hill H. Allen O. , Powell Trevor
Published: September 2002

The advent of scanning probe microscopy has introduced a powerful new method of probing the structural features of biological specimens. In this study, high resolution atomic force microscopy micrographs of single, isolated, cardiac myocytes are presented. Significantly, our images show not only the features to be expected of the external sarcolemma, but also resolve sub‐surface features, including the striated pattern of the contractile proteins and their associated sarcoplasmic reticulum and mitochondria.
Chemical concentrations of overland flow and throughflow from pastures on sloping texture-contrast soils
Authors: Cox J. W. , Pitman A.
Published: September 2002

Shallow drains are increasingly being installed to allow cropping and improve
pastures in soils prone to waterlogging. Concentrations and loads of a range
of chemicals including nitrate, dissolved organic carbon, and phosphorus were
measured in overland flow and throughflow (drainage) from grazed standard and
improved pastures in a region of the Adelaide Hills, South Australia, with 544
mm annual rainfall.
In low to average rainfall years, nitrate losses from standard pastures were
up to 21 times higher in throughflow (up to 0.3 kg/ha.year) than in
overland flow. Dissolved organic carbon losses from standard pastures were
also highest in throughflow (up to 3.5 kg/ha.year) as were loads of Na,
Cl, Al, Fe, K, and Mg. Total P loads were higher in throughflow (0.15
kg/ha.year) than in overland flow. However, P concentrations in
throughflow were similar to overland flow (up to 0.5 mg/L).
Chemical loads from improved pastures were higher in throughflow than in
overland flow. Nitrate, dissolved organic carbon, and P losses from improved
pastures were up to 0.8, 8.5, and 0.1 kg/ha.year, respectively. Improved
pastures had higher dissolved organic carbon concentrations (14 mg/L) and
nitrate concentrations than either the standard pastures or those reported off
some dairy pastures in the region. Nitrate concentrations were highest in
throughflow in subsurface tube drains below the improved pastures (up to 67
mg/L).
Genetic improvement and agronomy for enhanced wheat competitiveness with weeds
Authors: Lemerle D. , Gill G. S. , Murphy C. E. , Walker S. R. , Cousens R. D. , Mokhtari S. , Peltzer S. J. , Coleman R. , Luckett D. J.
Published: September 2002

The rapid development of herbicide resistance in weeds, and environmental
imperatives, have forced the consideration of non-chemical tactics such as
crop competition for weed management. This review of wheat–weed
competition examines the plant traits associated with wheat competitiveness,
and the opportunities for plant breeding or manipulating crop agronomy to
differentially favour the growth of the crop. Many studies have proven that
enhancing crop competitive ability can reduce weed seed production and crop
yield loss, although a number of difficulties in conducting this research are
identified and suggestions are made for improvement. It remains to be seen
whether crop competitiveness will be considered as a priority by farmers and
plant breeders. Farmers require precise information on the reliability of
agronomic factors such as increased crop seeding rate or choice of variety for
enhancing crop competitive ability in different environments. Plant breeders
need to know which plant traits to incorporate in varieties to increase
competitive ability. A thorough analysis of the benefits and costs of
enhancing wheat competitiveness is needed. Competitive wheat crops should be
available as part of reliable and economical integrated weed management
packages for farmers.
Photosynthetic and developmental traits associated with genotypic differences in durum wheat yield across the Mediterranean basin
Authors: Villegas D. , Aparicio N. , Nachit M.M. , Araus J. L. , Royo C.
Published: September 2002

The relationships between various morphophysiological traits and yield were
studied in durum wheat (Triticum durum Desf.) grown in
Mediterranean conditions. Two sets of 22 genotypes were used. One was
developed for semi-humid environments (TA-genotypes) and was cultivated in 22
trials around the Mediterranean basin with a mean yield across genotypes and
environments of 4925 kg/ha. The other set was developed for drier
conditions (CA-genotypes) and was cultivated in 15 trials, with a mean yield
of 3501 kg/ha. Morphophysiological traits for each set were evaluated in 2
trials with contrasting water regimes conducted in north-eastern Spain:
Lleida-rainfed (LR) and Lleida-irrigation (LI). Two kinds of traits were
evaluated: developmental traits, including early vigour, plant height, and
phenology (days from planting to heading and to maturity); and traits related
to photosynthetic performance such as canopy temperature and chlorophyll
content of the flag leaf, both measured during grain filling, and carbon
isotope discrimination of mature grains. All the traits, measured in both
Lleida trials, were related to the mean yield of the same genotypes across all
the sites where they were cultivated. Yield measured at either of the 2
environments at Lleida was a much poorer predictor of genotype differences in
mean yield than most of the traits. Nevertheless, the kind of environment
where the morphophysiological traits were evaluated affected the performance
of these traits as yield predictors. The combination of significant traits
measured in the better environment (LI) explained 71% and 55% of
genotype variability in yield within TA- and CA-genotypes, respectively, but
only 56% and 27% when they were evaluated at LR. On the other
hand, growing conditions of the yield trials was the main factor determining
the best combination of traits. For TA-genotypes, larger yields were
associated with shorter plants and higher carbon isotope discrimination
(Δ) of grains, and to a lesser extent with higher early vigour and lower
canopy temperature, whereas phenological traits made no contribution to
explaining genotype differences in yield. For the CA-genotypes, higher yields
were related to an earlier heading date or alternatively to a higher
chlorophyll content during grain filling. A higher Δ in mature kernels
also seems to be a positive trait.
Water balance changes in a crop sequence with lucerne
Authors: Dunin F. X. , Smith C. J. , Zegelin S. J. , Leuning R.
Published: September 2002

In a detailed study of soil water storage and transport in a sequence of 1
year wheat and 4 years of lucerne, we evaluated drainage under the crop and
lucerne as well as additional soil water uptake achieved by the subsequent
lucerne phase. The study was performed at Wagga Wagga on a gradational clay
soil between 1993 and 1998, during which there was both drought and high
amounts of drainage (>10% of annual rainfall) from the rotation.
Lucerne removed an additional 125 mm from soil water storage compared with
wheat (root-zone of ~1 m), leading to an estimated reduction in drainage to
30–50% of that of rotations comprising solely annual crops
and/or pasture.
This additional soil water uptake by lucerne was achieved through apparent
root extension of 2–2.5 m beyond that of annual crops. It was effective
in generating a sink for soil water retention that was about double that of
annual crops in this soil. Successful establishment of lucerne at 30
plants/m2 in the first growing season of the pasture
phase was a requirement for this root extension. Seasonal water use by lucerne
tended to be similar to that of crops in the growing season between May and
September, because plant water uptake was confined to the top 1 m of soil.
Uptake of water from the subsoil was intermittent over a 2-year period
following its successful winter establishment. In each of 2 annual periods,
uptake below 1 m soil depth began late in the growing season and terminated in
the following autumn.
Above-ground dry matter production of lucerne was lower than that by crops
grown in the region despite an off-season growth component that was absent
under fallow conditions following cropping. This apparent lower productivity
of lucerne could be traced in part to greater allocation of assimilate to
roots and also to late peak growth rates at high temperatures, which incurred
a penalty in terms of lower transpiration efficiency. The shortfall in herbage
production by lucerne was offset with the provision of timely, high quality
fodder during summer and autumn. Lucerne conferred indirect benefits through
nitrogen supply and weed control. Benefits and penalties to the agronomy and
hydrology of phase farming systems with lucerne are discussed.
Lupinus angustifolius has a plastic uptake response to heterogeneously supplied nitrate while Lupinus pilosus does not
Authors: Dunbabin V. , Rengel Z. , Diggle A.
Published: September 2002

Uptake rates calculated from plants uniformly supplied with a nutrient will
underestimate uptake under heterogeneous conditions. A split-root nutrient
solution experiment was set up to compare the uptake rate of 2 lupin species
(Lupinus angustifolius L.,
L. pilosus Murr.) under conditions of uniform and
heterogeneous nitrate supply. Nitrate was supplied uniformly to the root
system at 250 M (low), 750 M (high), or 1500 M (high), or in a split
low/high or high/low combination between the upper and lower root
system.
While L. pilosus had a greater total nitrate uptake over
the treatment period due to a higher total root length,
L. angustifolius had 1.5–2.5 times greater nitrate
uptake rate per unit of root length. L. angustifolius
also had the capacity to increase the nitrate uptake rate in sections of the
root system supplied locally with high nitrate, compared with a root system
uniformly supplied with high nitrate. This increased uptake rate under
heterogeneous supply enabled the plant to take up 74–94% of the
total nitrate taken up when uniformly supplied with high nitrate, while only
58–72% would have been taken up without such a compensation
mechanism. L. pilosus did not show this response. The
difference between the response of these 2 species suggests that a range of
nitrate uptake responses may exist across the lupin germplasm, and that it may
be possible to select a lupin species with an enhanced ability to capture
nitrate from the profile, thus decreasing nitrate losses from leaching.
Chinese adzuki bean germplasm: 1. Evaluation of agronomic traits
Authors: Wang S. M. , Redden R. J. , Jiapeng J. P. Hu , Desborough P. J. , Lawrence P. L. , Usher T.
Published: September 2002

A core collection of adzuki beans, representing the germplasm of Chinese land
races, was screened at Warwick Australia in a replicated yield trial sown
mid-summer. Grain yield, yield components, phenologic traits, vegetative
characteristics, and morphologic descriptors were recorded for all accessions
plus Japanese-derived check varieties.
Accessions from southern China were later flowering, had smaller seed, and
grew taller than those from central China. Grain yield was greatest for
accessions from central China, whereas both north Chinese and Japanese check
accessions were generally low yielding.
The evaluation of diversity displayed trends associated with latitude of
germplasm origin, which were positive or negative according to the trait.
Similarly, the germplasm diversity in duration of crop growth phases and in
rate of yield expression was also associated with latitude of landrace origin.
Localised variations from these trends were found for seed size and for number
of pods per plant. Various trends with latitude of origin were found for
natural incidence of powdery mildew, for growth habit, plant height, vining
and leaf colour. However, traits not associated with latitude of germplasm
origin included primary and secondary seed colour, mature pod colour, and
degree of branching.
The evaluation suggests that selections from this greater range of genetic
diversity may allow higher yielding varieties than the current
Japanese-derived standards to be developed for Australia.
Effect of integrated nutrient management on a Typic Haplaquant on yield and nutrient availability in a rice-wheat cropping system
Authors: Singh K. N. , Prasad B. , Sinha S. K.
Published: September 2002

A field experiment was conducted at Mithapur Farm, Patna Campus of the
Rajendra Agricultural University, Bihar, India, with rice (cv. Mahsoori) and
wheat (cv. UP 262) during 1992–96 in order to assess the integrated
effect of chemical fertilizer (NPK) with farmyard manure (FYM) and blue-green
algae (BGA) on grain yield and nutrient availability on a Typic Haplaquant.
Both rice and wheat yields continued to increase significantly with increasing
NPK level up to 100% of the recommended rate. However, maximum yields
of rice and wheat were obtained where the recommended rate of NPK was applied
along with FYM and BGA. The organic carbon content of the soil decreased up to
the rate of 50% of the recommended NPK, either alone or in combination
with FYM, BGA, or FYMM+BGA. Available soil nutrients were enhanced up
to rates of 75% of the recommended NPK dosage, alone or with FYM, BGA,
or FYMmp;plus;BGA, compared with initial values. The maximum build-up of
available N, P, and K was measured under integrated use of 100% NPK
along with FYM and BGA.
Learning to bridge the gap between science-based decision support and the practice of farming: Evolution in paradigms of model-based research and intervention from design to dialogue
Authors: McCown R. L.
Published: September 2002

Application of science in agriculture has been primarily to the ongoing
improvement of material technologies. But there has also been an expectation
that science, in a ‘systems’ mode, could, and should, contribute
to improved planning and decision making by farmers. For over 30 years
computerised models of farm economies or production systems have claimed the
ability to identify superior alternatives for management action. Over this
period, model competence has improved immensely, and farm computer ownership
has grown to high levels, but this has not generated conspicuous or sustained
enthusiasm among farmers or their advisers.
This paper examines the experience of model-based interventions in farming
practice in search of insights to both past failure and future possibilities
for models with seemingly impressive capability to be relevant and significant
to managers in the challenging task of achieving sustainable farming. The
strategy is to ‘stand back’ far enough to see conceptual and
historical ‘connections’ between research and farming from a
vantage point where the difference between a systems view and a philosophical
view becomes indistinct. An adaptation of Karl Popper’s ‘three
worlds’ model serves as a ‘map’ of the differences among
types of knowledge and among three paradigms for scientific intervention in
practice. This aids explanation of the ‘gaps’ between research and
practice when: (1) researchers design ‘best
practice’ for practitioners using theoretical models,
(2) researchers provide practitioners with
practice-guiding tools, and (3) researchers with theory
and models collaborate with practitioners to research ‘best
practice’ in the context of practice. The benefits and challenges of an
approach for bridging ‘the gap’ which uses multiple rationalities
and research paradigms are discussed.
Different responses of broilers at low, high, or cyclic moderate-high temperatures to dietary sodium bicarbonate supplementation due to differences in dietary formulation
Authors: Balnave D. , Brake J.
Published: September 2002

0es; temperature and NaHCO
3 cant NaHCO
3 ificant overall effect on production parameters but significant NaHCO
3 × temperature and NaHCO
3 × diet interactions were observed for BWG.
Sodium bicarbonate improved BWG at constant 31high
(25°derate—high
(25°—35cyclic moderate—high
(25°—35°C) temperature regimens. Dietary
formulations using typical Australian feed ingredients and varying in protein
sources were used with one diet containing only animal-source protein
ingredients (Diet 1) and the other diet containing predominantly plant-source
protein ingredients (Diet 2). Feed intake and bodyweight gain (BWG) of
broilers exposed to constant high or diurnal cyclic temperature regimens were
similar and significantly poorer than those of broilers exposed to low
temperatures. Dietary supplementation with NaHCO 3 had
no significant overall effect on production parameters but significant NaHCO
3×temperature and NaHCO
3×diet interactions were observed for BWG.
Sodium bicarbonate improved BWG at constant 31°C, but not at constant
20NaHCO
3 × temperature and NaHCO
3 cant NaHCO
3 ificant overall effect on production parameters but significant NaHCO
3 × temperature and NaHCO
3 × diet interactions were observed for BWG.
Sodium bicarbonate improved BWG at constant 31high
(25°derate—high
(25°—35cyclic moderate—high
(25°—35°C) temperature regimens. Dietary
formulations using typical Australian feed ingredients and varying in protein
sources were used with one diet containing only animal-source protein
ingredients (Diet 1) and the other diet containing predominantly plant-source
protein ingredients (Diet 2). Feed intake and bodyweight gain (BWG) of
broilers exposed to constant high or diurnal cyclic temperature regimens were
similar and significantly poorer than those of broilers exposed to low
temperatures. Dietary supplementation with NaHCO 3 had
no significant overall effect on production parameters but significant NaHCO
3×temperature and NaHCO
3×diet interactions were observed for BWG.
Sodium bicarbonate improved BWG at constant 31°C, but not at constant
20°C, or in the diurnal cyclic temperature regimen. Sodium bicarbonate
significantly improved BWG with Diet 2 (plant-source proteins), which
contained an arginine : lysine ratio of 1.31 but not with Diet 1
(animal-source proteins), which contained an arginine : lysine ratio of 1.01.
Interactions of boron-toxicity, drought, and genotypes on barley root growth, yield, and other agronomic characters
Authors: Yau S. K.
Published: September 2002

In areas with high levels of soil boron, symptoms of boron (B) toxicity often
appear under droughts. This greenhouse study examined the interactions of
B-toxicity, drought, and genotypes on barley
(Hordeum vulgare L.) root growth, B-toxicity symptoms, B
concentrations of straw, and yield. Plants were grown in tubes 65 cm tall.
Three factors were studied: B, water supply, and genotypes. There were 2 B
levels, B0 v. B50, in the subsoil (20-60 cm). There were 4 levels of water
supply: no drought (control), and early, mid-season, and terminal drought. Two
barley lines were compared: Sahara (B-toxicity tolerant) and BOL (drought
tolerant, B-toxicity sensitive). Significant B-by-drought interaction was
detected in straw B concentration, root growth in subsoil, and straw and
biological yield for BOL. Mean root growth in the 40–60-cm soil section
was much higher under mid-season drought than under the control. At B50,
plants under drought had 1-fold higher straw B concentrations and more
B-toxicity symptoms than the control plants. This is the first study to
provide data to explain the frequent association of B-toxicity symptoms with
droughts in the field. The results clearly showed that tolerance to
B-toxicity, as well as drought, is needed in dry areas having high levels of
subsoil B.
Inheritance of root glucosinolate content in canola
Authors: Kirkegaard J. A. , Rebetzke G. J. , Richards R. A.
Published: September 2002

0
An experiment to investigate the ameliorative effects of foliar potassium phosphate sprays on salt-stressed strawberry plants
Authors: Kaya Cengiz , Kirnak Halil , Higgs David
Published: September 2002

A pot experiment was carried out with strawberry
(Fragaria ananassa Duch) cvv. Oso
Grande and Camarosa in sand culture to investigate the effects of foliar
application of 4 mM KH2PO4to
plants grown both at high NaCl concentration (35 mM) supplied via roots and in
complete nutrient solution. Treatments were (1) nutrient
solution (C); (2) nutrient solution + 4 mM
KH2PO4 as a foliar application
(C+Fo); (3) nutrient solution + 35 mM NaCl
(C+S); and (4) nutrient solution + 35 mM
sodium chloride + 4 mM
KH2PO4as a foliar application
twice weekly (C+S+Fo). The plants grown at high NaCl had less dry
matter, fruit yield, and chlorophyll content than those grown in normal
nutrient solution for both cultivars. Foliar
KH2PO4sprays ameliorated the
negative effects of salinity on plant growth and fruit yield. Water use by
plants decreased with elevated NaCl and increased with foliar
KH2PO4 sprays. Membrane
permeability increased with high NaCl and was reduced by
KH2PO4 sprays. Sodium
concentration in plant tissues increased in both cultivars in the high NaCl
treatment. Concentrations of P and K were in the deficient range in plants
grown at high NaCl and these deficiencies were corrected by foliar
KH2PO4.
Relationships between age and biomass of individual plants and seed production in two grazed tropical legumes. 1. Derivation of relationships
Authors: McDonald C. K. , Jones R. M.
Published: September 2002

The distributions of individual plant age and biomass of
Chamaecrista rotundifolia cv. Wynn and a mix of
Stylosanthes scabra cvv. Seca and Fitzroy in grazed
grass–legume pastures were examined to determine their effect on seed
production. The effects of enhanced soil water conditions and severe
defoliation on seed production were assessed in ungrazed plots. These
experiments were part of a larger study to develop a demographic model of
perennial forage legumes.
The distribution of individual plant age and biomass was highly skewed towards
a large number of young/small plants, with fewer old/large plants.
Lack of seed set when stem length was less than approximately 200 mm, and in
most small plants (<2 g), resulted in older/larger plants contributing
far more to seed production and, to a lesser extent, legume biomass, than they
did to legume plant numbers.
C. rotundifolia seed production was linearly related to
individual plant biomass but was highly varaiable and was greatly reduced in
swards containing >3000 kg/ha of grass. Using log-transformed data,
plant biomass accounted for 74% of the variation in seed production
(SP), but together with grass biomass accounted for 91% of the
variation [ln(SP) = 6.01 + 0.91*ln(BIOMASS) –
0.28*ln(GRASS BIOMASS), P < 0.001]. Total
legume biomass accounted for only 44% of the variation in seed
production.
S. scabra herbage allowance (kg legume/head) had a
major impact on seed production. Total legume biomass and individual plant
biomass alone accounted for less than 40% of the variation in seed
production. Using herbage allowance (HA) as well as individual plant biomass
improved the prediction of seed production (SP) to account for 74% of
the variation [ln(SP) = 0.11 + 1.14*ln(BIOMASS) +
0.24*ln(HA), P < 0.001].
Enhanced soil water conditions increased the biomass of individual plants of
both species and increased the seed production per gram of plant in
S. scabra but not in
C. rotundifolia. Severe defoliation in early summer or
autumn can greatly reduce or even eliminate seed production by some plants by
removal of flowers, reducing individual plant biomass, or allowing
insufficient time for plants to reach minimum stem lengths.
The different factors affecting seed production in the 2 species highlight the
complexity of legume seed set in grazed pasture systems, and some implications
for grazing management and modelling are discussed.