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A Rowe

Publications and source records attributed to A Rowe.

At least 37 records · Page 2Linked to original sources
PubMed1996

Investigations into the molecular size and shape of tomato extensin.

The molecular characteristics of soluble extensin from tomato have been investigated. An apparent molecular mass greater than 240 kDa has been previously observed with the shape-dependent method of gel-filtration chromatography [Brownleader and Dey (1993) Planta (Berlin) 191, 457-469]. Tomato extensin is a heavily glycosylated protein that does not migrate into SDS/polyacrylamide gels. This shape-dependent behaviour raises doubts about agreement between the observed apparent mass and the absolute value. The molecular mass measured with matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry (MALDI-TOF MS) was 72.3 kDa, with no evidence of any other species except a doubly charged ion. The sample was therefore considered to be monodisperse under the conditions used. Electron microscopy of soluble extensin showed the presence of particles 40-50 nm in length and 2.0-2.5 nm in width. A minority of these particles showed a central 'kink'. A number of smaller and generally wider particles (20 nm x 2-4 nm) were considered to be folded monomers and larger particles were thought to be dimers. Sedimentation analysis showed that extensin exists in a rapid monomer-dimer equilibrium in the concentration range and buffer used. Sedimentation equilibrium data gave a Kd of 8.5 microM and sedimentation velocity data generated a Kd between 1 and 10 microM. The concentration dependence of the measured sedimentation coefficient was used, together with hydrodynamic bead modelling, to define plausible shapes for monomer and dimer. This suggests that monomeric extensin is an elongated rod of length 40 nm and width 2 nm, which forms staggered dimers of average length 50 nm and width 3 nm. Extensin is an integral component of the primary cell wall. The physical characteristics (size, shape and form) of the rod-like extensin have been evaluated in this paper so that the role that extensin plays in primary cell wall architecture and during plant disease resistance can be more fully understood.

Cells, Cultured↗
PubMed1995

Expression of the chicken retinoid X receptor-gamma gene in migrating cranial neural crest cells.

We have used in situ hybridisation to whole chick embryos with digoxygenin-labelled probes to investigate the distribution of RXR-gamma transcripts during neural crest cell migration in the developing head and the anterior of the trunk (the vagal region), where neural crest cells make a substantial contribution. We have found that RXR-gamma transcripts are a good marker for migrating neural crest cells in the chick embryo. RXR-gamma transcripts were first detected in cells that had recently emerged from the neural crest, providing an earlier marker for neural crest cells than the HNK-1 epitope. The pattern of RXR-gamma transcript distribution is dynamic in the developing chick head, and changes in a pattern which is coincident with the migration of cells containing RXR-gamma transcripts and the gradual restriction of RXR-gamma transcripts to specific differentiating neural crest derivatives. Transcripts appeared to be present initially in migrating neural crest cells thoughout the developing head, but gradually became restricted to some crest-derived populations and absent from others. By stage 15, RXR-gamma transcripts were not detectable in neural-crest-derived ectomesenchymal cells, although they were still found in cells contributing to the cranial ganglia and their roots.

Animals↗
PubMed1995

Plasmodium falciparum rosetting is associated with malaria severity in Kenya.

Rosette formation in 154 fresh Plasmodium falciparum isolates from Kenyan children with mild (n = 54), moderate (n = 64), or severe (n = 36) malaria was studied to determine whether the ability to form rosettes in vitro is correlated with malaria severity. There was a wide distribution of rosette frequencies within each clinical category; however, a clear trend towards higher rosette frequency with increasing severity of disease was seen, with the median rosette frequency of the mild-malaria group (1%; range, 0 to 82%) being significantly lower than those of the moderate-malaria group (5%; range, 0 to 45%; Mann-Whitney U test, P < 0.02) and the severe-malaria group (7%; range, 0 to 97%; Mann-Whitney U test, P < 0.003). Within the severe-malaria category there was no difference in rosetting among isolates from cerebral malaria patients or those with other forms of severe malaria. We also examined the ABO blood groups of the patients from whom isolates were obtained and found that isolates from group O patients (median rosette frequency, 2%; range 0 to 45%) rosetted less well than those from group A (median, 7%; range 0 to 82%; Mann-Whitney U test, P < 0.01) or group AB (median, 11%; range 0 to 94%; Mann-Whitney U test, P < 0.03). We therefore confirm that rosetting is associated with severe malaria and provide further evidence that rosetting is influenced by ABO blood group type. Whether rosetting itself plays a direct role in the pathogenesis of severe malaria or is a marker for some other causal factor remains unknown.

ABO Blood-Group System↗
PubMed1995

Role of mutations G-480 and C-6203 in the attenuation phenotype of Sabin type 1 poliovirus.

Of the 55 point mutations which distinguish the type 1 poliovirus vaccine strain (Sabin 1) from its neurovirulent progenitor (P1/Mahoney), two have been strongly implicated by previous studies as determinants of the attenuation phenotype. A change of an A to a G at position 480, located within the 5' noncoding region, has been suggested to be the major attenuating mutation, analogous to the mutations at positions 481 and 472 in poliovirus types 2 and 3, respectively. In addition, the change of a U to a C at position 6203, resulting in an amino acid change in the polymerase protein 3D, has also been implicated as a determinant of attenuation, albeit to a lesser extent. To assess the contributions of these mutations to attenuation and temperature sensitivity, reciprocal changes were generated at these positions in infectious cDNA clones of Sabin 1 and P1/Mahoney. Assays in tissue culture and primates indicated that the two mutations make some contribution to the temperature sensitivity of the Sabin 1 strain but that neither is a strong determinant of attenuation.

Cell Line↗
PubMed1994

Effect of parathyroid hormone-related peptide supplementation of soy protein formulas in the neonatal pig model.

PTH-related peptide (PTHrP) is found in all milks, including human and pig. To define a role for PTHrP in milk, 2-day-old piglets were randomized to receive soy formula devoid of PTHrP or supplemented with 1 nM synthetic PTHrP(1-86) (n = 8 per group). The number of serum samples with detectable PTHrP by immunoassay (Incstar) and radiometric assay (Nichols) was 9 of 33 and 3 of 13 in PTHrP- and 8 of 27 and 3 of 15 in PTHrP+ formula-fed piglets and 8 of 14 and 7 of 12 in naturally suckling piglets, respectively. Serum and urine concentrations of calcium and magnesium and total and bone alkaline phosphatase were similar in both groups at 3, 6, 10, and 17 days of age. No differences were seen in bone mineral content of the tibia measured by single-photon absorptiometry (BMC 0.22 +/- 0.06 and 0.22 +/- 0.10) or dual x-ray absorption (BMC 1.43 +/- 0.36 and 1.31 +/- 0.78) either in vivo or on excised bone or by measurement of Ca, Mg, or P content or total bone ash (1.26 +/- 0.26 and 1.38 +/- 0.28 mg). Intestinal histology, serum intestinal alkaline phosphatase, and net absorption and retention of Ca, Mg, and P in balances from age 11-17 days were all similar. As in humans, however, a developmental pattern was seen for phosphorus regulation in both groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Absorptiometry, Photon↗
PubMed1994

Plasmodium falciparum: a family of sulphated glycoconjugates disrupts erythrocyte rosettes.

The ability of Plasmodium falciparum-infected erythrocytes to form spontaneous rosettes with uninfected red cells is a parasite adhesion property which has been associated with severe malaria. The mechanism of rosetting remains unknown, but the ability of heparin to disrupt rosettes has been recognised previously. In this paper we show that a group of sulphated glycoconjugates including sulphatide, dextran sulphate, and fucoidan are more effective rosette reversing agents than heparin and are active against both laboratory strains and wild isolates. Other related anionic glycosaminoglycans such as the chondroitin sulphates A, B, and C and hyaluronic acid have no effect on rosette formation. This family of sulphated glycoconjugates which are active against rosettes is also known to inhibit sporozoite invasion of hepatocytes and merozoite reinvasion of erythrocytes, suggesting that sulphated glycoconjugate interaction may be an important process in cell adhesion at different stages in the plasmodial life cycle.

Animals↗
PubMed1994

Diversity management: practical application in a health care organization.

Lee Gardenswartz and Anita Rowe extend our lead author's contributions to diversity management by suggesting a framework for organizational development that can create an "inclusive" environment for enhancing the productivity and service quality of its staff. The framework includes attention to (1) individual attitudes and beliefs, (2) organizational values and policies, and (3) management skills and practices. The common ground among these three aspects is change. Gardenswartz and Rowe posit that substantial change is necessary to realize maximum value from diversity, and therefore barriers to organizational, attitudinal and managerial behavioral change must be acknowledged and overcome.

Employment↗
PubMed1993

Plasmodium falciparum varies in its ability to induce tumor necrosis factor.

Tumor necrosis factor (TNF) has a variety of protective and pathological actions in human malaria. We report that different laboratory lines of Plasmodium falciparum which were derived from a single wild isolate (IT 4/25/5) varied widely in their ability to stimulate TNF production by human mononuclear cells. In the cloned line R29 we observed that subcultures selected for high rosetting frequency gave significantly higher levels of TNF stimulation than subcultures with low rosetting frequency, indicating that TNF induction can vary within populations that have originated from a single genotype. These results raise the possibility that the clinical severity of malaria is partly determined by the TNF-inducing activity of the infecting strain of parasite.

Animals↗
PubMed1993

Group work. Cope street revisited.

45 Cope Street is a preventive health project working with pregnant women and young mothers aged between 16 and 25 years and their children in the inner city of Nottingham. A beacon of innovative health visiting practice, it has recently passed the fifth anniversary of its opening. Team leader Ann Rowe describes their philosophy and practice.

Community Health Nursing↗
PubMed1992

In vivo and in vitro characterization of overproduced colicin E9 immunity protein.

We report the overproduction of the immunity protein for the DNase colicin E9 and its characterization both in vivo and in vitro. The genes for colicin immunity proteins are normally co-expressed from Col plasmids with their corresponding colicins. In the context of the enzymatic colicins, the two proteins form a complex, thereby protecting the host bacterium from the antibiotic activity of the colicin. This complex is then released into the medium, whereupon the colicin alone translocates (through the appropriate receptor) into sensitive bacterial strains, resulting in bacterial cell death. The immunity protein for colicin E9 (Im9) has been overproduced in a bacterial host in the absence of its colicin, to enable sufficient material to be isolated for structural studies. As a prelude to such studies, the in-vivo and in-vitro properties of overproduced Im9 were analysed. Electrospray mass spectrometry verified the molecular mass of the purified protein and analytical ultracentrifugation indicated that the native protein approximates a symmetric monomer. Fluorescence-enhancement and gel-filtration experiments show that purified Im9 binds to colicin E9 in a 1:1 molar ratio and that this binding neutralizes the DNase activity of the colicin. These results lay the foundations for a full biophysical and structural characterization of the colicin E9 DNase inhibitor protein, Im9.

Bacterial Proteins↗
PubMed1992

Position-dependence of retinoic acid receptor-beta gene expression in the chick limb bud.

Retinoic acid and 3,4-didehydroretinoic acid are metabolites of vitamin A that can induce duplications and other malformations when locally applied to the anterior margin of the chick limb bud. There is evidence that they may be natural signaling substances in the limb bud. Both compounds are thought to act by binding to ligand-dependent transcription factors that belong to the steroid/thyroid hormone nuclear receptor superfamily. In situ hybridization analyses show that in the mesenchyme of the chick wing bud between embryonic stages 20 and 27, retinoic acid receptor-beta (RAR-beta) transcripts are restricted to the proximal region of the bud and are present at highest levels in the region of the limb bud mesenchyme that contributes to the shoulder. We have performed grafting experiments in order to examine whether RAR-beta gene expression in limb bud mesenchyme cells is cell-autonomous or whether it is dependent upon the cell's position within the limb bud. When tissue from the proximal region of the stage 22 wing bud, which contains high levels of RAR-beta transcripts, was grafted to the distal tip of the bud, RAR-beta transcripts were undetectable in the graft 6 hr later. When tissue from the distal tip of the bud was grafted to a proximal site, most of the grafts exhibited a slight increase in the level of RAR-beta transcripts, which was detectable 6 hr after grafting. However, the levels of RAR-beta transcripts in these grafts never approached those found in the proximal core of the bud. These data indicate that RAR-beta gene expression in the chick wing bud is position-dependent in that it is repressed at the distal tip of the bud and partially activated by grafting distal tissue to a proximal site. However, accumulation of RAR-beta transcripts to high levels appears to be a characteristic of mesenchyme that was initially specified to form proximal structures.

Animals↗
PubMed1992

Ets-1 and Ets-2 protooncogene expression in theca cells of the adult mouse ovary.

We have investigated the mRNA expression of the Ets-1 and Ets-2 genes in murine gonads and found expression in adult ovaries. In situ hybridization experiments show that the Ets genes are predominantly expressed in theca cells and cells of ovarian interstitium. By gel retardation experiments we detected DNA binding proteins in ovaries that specifically bind to the ETS motif, suggesting the expression of Ets or Ets-related proteins. Our results raise the possibility of Ets-2 involvement in ovarian pathology seen in patients with Down's syndrome.

Animals↗
PubMed1992

Development of the spatial pattern of retinoic acid receptor-beta transcripts in embryonic chick facial primordia.

Retinoic acid causes a range of embryonic defects, including craniofacial abnormalities, in both birds and mammals and is believed to have a number of roles in normal development. We have previously shown that the distribution of retinoic acid receptor-beta (RAR-beta) transcripts is spatially restricted within the neural-crest-derived upper beak primordia of the chick embryo. We have now used in situ hybridisation to trace the distribution of RAR-beta transcripts during the migration of cranial neural crest cells and during formation of these primordia. RAR-beta transcripts were present in a subset of migrating neural-crest-derived cells in the head of the stage 10 embryo. These cells were situated in pathways followed by cells that migrate from the neural crest overlying the posterior prosencephalic/anterior mesencephalic region of the developing brain. Cells containing RAR-beta transcripts accumulated around the developing eyes and in the regions of the ventral head from which the upper beak primordia later develop. We mapped the distribution of RAR-beta transcripts as the facial primordia were forming, with particular reference to the development of the maxillary primordia. We found that these form in a region of the ventral head that includes the boundary between regions of high and low levels of RAR-beta transcripts. The boundary between these two groups of cells persisted as the maxillary primordia developed.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗