Biomedical subjects

J Rowe

Publications and source records attributed to J Rowe.

At least 19 recordsLinked to original sources

PubMed2005

Management of the patient and family with neurofibromatosis 2: a consensus conference statement.

A consensus conference on neurofibromatosis 2 (NF2) was held in 2002 at the request of the United Kingdom (UK) Neurofibromatosis Association, with particular emphasis on vestibular schwannoma (VS) surgery. NF2 patients should be managed at specialty treatment centres, whose staff has extensive experience with the disease. All NF2 patients and their families should have access to genetic testing because presymptomatic diagnosis improves the clinical management of the disease. Some clinical manifestations of NF2, such as ocular abnormalities, can be detected in infancy; therefore, clinical screening for at-risk members of NF2 families can start at birth, with the first magnetic resonance (MRI) scan at 10-12 years of age. Minimal interference, maintenance of quality of life, and conservation of function or auditory rehabilitation are the cornerstones of NF2 management, and the decision points to achieve these goals for patients with different clinical presentations are discussed.

Adult↗

PubMed2004

Enhancement of vaccine-specific cellular immunity in infants by passively acquired maternal antibody.

The known protective effects of passively acquired maternal antibody on the resistance of newborns to infections have prompted widespread interest in maternal vaccination. However, a range of animal model and human studies indicate potential inhibitory effects of maternal antibody on vaccine-specific humoral responses in infants. In the present study we have examined the relationship between maternally acquired TT-specific IgG present before DTaP vaccination and subsequent TT-specific T-cell memory responses at 12 and 18 months, in a cohort of 118 infants. We demonstrate a strong positive association between TT-specific cellular immunity as evidenced by increased IL-4, IL-5 and IL-13 responses, and maternal TT-specific IgG.

Antibodies, Bacterial↗

PubMed2004

Interaction of cocultured decidual endothelial cells and cytotrophoblasts in preeclampsia.

Disturbed cell-cell communication between trophoblasts and the maternal endothelium may be responsible for the deficient endovascular invasion seen in preeclampsia. In vitro studies have been hampered by lack of suitable models to directly examine interactions between these cell types. Using a bilayer coculture model, we examined the effect of decidual endothelial cells on matrix metalloproteinase secretion and the migration of cytotrophoblasts from preeclamptic pregnancies. Cells were incubated on semipermeable membranes in 20% or 2% O(2) with or without the tumor promoter phorbol 12-myristate 13-acetate, which activates matrix metalloproteinase-2 and -9 in endothelial cells. Cytotrophoblasts from preeclamptic pregnancies secreted significantly less matrix metalloproteinase-2 and -9 than their normal counterparts. Although decidual endothelial cells downregulated cytotrophoblast migration in normal pregnancy, this was not observed in cocultures with cytotrophoblasts from preeclamptic pregnancies. In addition, cytotrophoblasts from preeclamptic pregnancies altered phorbol myristate acetate-induced activation of endothelial matrix metalloproteinases. Hypoxia increased cytotrophoblast migration when cells were incubated alone but not in coculture with decidual endothelial cells due to increased adhesion between the two cell types. These results suggest dysfunctional interactive regulation of migration and matrix metalloproteinase secretion in preeclampsia that could result in abnormal endovascular trophoblast invasion of the maternal vasculature.

Cell Communication↗

PubMed2003

Conserved simple sequence repeats for the Limnanthaceae (Brassicales).

The Limnanthaceae (Order Brassicales) is a family of 18 taxa of Limnanthes (meadowfoam) native to California, Oregon, and British Columbia. Cultivated meadowfoam ( L. alba Benth.), a recently domesticated plant, has been the focus of research and development as an industrial oilseed for three decades. The goal of the present research was to develop several hundred simple sequence repeat (SSR) markers for genetic mapping, molecular breeding, and genomics research in wild and cultivated meadowfoam taxa. We developed 389 SSR markers for cultivated meadowfoam by isolating and sequencing 1,596 clones from L. alba genomic DNA libraries enriched for AG(n) or AC(n) repeats, identifying one or more unique SSRs in 696 clone sequences, and designing and testing primers for 624 unique SSRs. The SSR markers were screened for cross- taxa utility and polymorphisms among ten of 17 taxa in the Limnanthaceae; 373 of these markers were polymorphic and 106 amplified loci from every taxon. Cross-taxa amplification percentages ranged from 37.3% in L. douglasii ssp. rosea (145/389) to 85.6% in L. montana (333/389). The SSR markers amplified 4,160 unique bands from 14 genotypes sampled from ten taxa (10.7 unique bands per SSR marker), of which 972 were genotype-specific. Mean and maximum haplotype heterozygosities were 0.71 and 0.90, respectively, among six L. alba genotypes and 0.63 and 0.93, respectively, among 14 genotypes (ten taxa). The SSR markers supply a critical mass of high-throughput DNA markers for biological and agricultural research across the Limnanthaceae and open the way to the development of a genetic linkage map for meadowfoam ( x = 5).

Base Sequence↗

PubMed2003

Developmental factors associated with risk for atopic disease: implications for vaccine strategies in early childhood.

There is growing interest in the potential interactions between infant vaccination and risk for development of atopic disease. The aspect of this issue which has dominated this debate concerns suggestions that infant vaccination may stimulate allergic sensitisation. These suggestions derive from retrospective epidemiological analyses and will remain speculative unless they can be confirmed in prospective studies, particularly as conflicting findings have been reported. However, there is a potentially more important issue surfacing in this debate, which entails the converse situation, i.e. that genetic risk for atopy influences capacity to respond to vaccination during infancy. Support for the latter possibility comes from recent studies on the role of developmental factors which determine immune competence during infancy, and attendant risk for inflammatory and infectious diseases. The relevant findings are reviewed briefly below.

Environment↗

PubMed2003

Presence of caprine arthritis-encephalitis virus (CAEV) proviral DNA in genital tract tissues of superovulated dairy goat does.

Transmission of caprine arthritis-encephalitis virus (CAEV) is not completely understood and the vertical route of infection from the goat to the embryo or to the fetus needs to be investigated. This route of infection involves the presence of CAEV in the genital tract tissues. Prior studies have detected CAEV-infected cells in genital secretions and in flushing media recovered during embryo collection from infected goats. To specify the origin of these cells, we conducted a double-nested polymerase chain reaction (PCR) test on embryo flushing media and on mammary gland, mammary lymph node, synovial membrane, pelvic lymph node, uterus and oviduct tissues from 25 CAEV-infected (blood PCR positive) embryo donor goats for the presence of CAEV proviral DNA. The presence of proviral DNA was found in 22 of 25 mammary gland samples, 14 of 25 uterus samples, and in 16 of 25 oviduct samples. Nineteen of 25 goats had at least one positive genital tract sample. Flushing media from 11 goats were PCR positive. All goats with positive-flushing media were oviduct positive. Of this group of does, except for 1 of the 11, infection of flushing media correlated with infection of almost all the other tissues examined. The frequency of positive tissues for flushing media-positive goats (61/66; 92%) was significantly higher than that for flushing media-negative goats (50/84; 60%) (P<0.01). This study demonstrated the presence of CAEV-infected cells in the goat genital tract. The presence of CAEV-infected cells in the uterus and oviducts suggests potential for vertical transmission of CAEV from doe to embryo or fetus.

Animals↗

PubMed2003

Activations related to "mirror" and "canonical" neurones in the human brain: an fMRI study.

In the macaque monkey ventral premotor cortex (F5), "canonical neurones" are active when the monkey observes an object and when the monkey grasps that object. In the same area, "mirror neurones" fire both when the monkey observes another monkey grasping an object and when the monkey grasps that object. We used event-related fMRI to investigate where in the human brain activation can be found that reflects both canonical and mirror neuronal activity. There was activation in the intraparietal and ventral limbs of the precentral sulcus when subjects observed objects and when they executed movements in response to the objects (canonical neurones). There was activation in the dorsal premotor cortex, the intraparietal cortex, the parietal operculum (SII), and the superior temporal sulcus when subjects observed gestures (mirror neurones). Finally, activations in the ventral premotor cortex and inferior frontal gyrus (area 44) were found when subjects imitated gestures and executed movements in response to objects. We suggest that in the human brain, the ventral limb of the precentral sulcus may form part of the area designated F5 in the macaque monkey. It is possible that area 44 forms an anterior part of F5, though anatomical studies suggest that it may be a transitional area between the premotor and prefrontal cortices.

Adult↗

PubMed2003

Specific patterns of responsiveness to microbial antigens staphylococcal enterotoxin B and purified protein derivative by cord blood mononuclear cells are predictive of risk for development of atopic dermatitis.

BACKGROUND: Mononuclear cells from children with active atopic dermatitis (AD) have been reported to be hyper-responsive to certain microbial stimuli, in particular staphylococcal enterotoxin B (SEB). However, it is not known whether this responsiveness is acquired during disease development, or is inherent. We investigated this question in a cohort of children at high risk of atopy followed prospectively from birth to age 3 years. We asked whether their cord blood mononuclear cell (CBMC) cytokine responses to SEB, to an unrelated microbial stimulus purified protein derivative (PPD), or to common allergens, were predictive of risk for subsequent AD development during infancy. METHODS: Children at high risk of developing atopy were randomly selected from an ongoing prospective cohort. Cord blood was collected at birth. The children were seen at 6 months, 1, 2 and 3 years and examined for the development of AD. IFN-gamma, IL-5, IL-10 and IL-13 production by CBMC cultured in the presence of SEB, PPD, PHA, house dust mite (HDM) allergen, ovalbumin (OVA) and cat allergen was determined. RESULTS: SEB-induced IL-5 production by CBMC was elevated in children who developed AD at 6 months (P = 0.01) and 2 years (P = 0.009). PPD-induced IL-5 responses were also elevated in CBMC from children who developed AD at 6 months, 2 years and 3 years (P = 0.05, P = 0.06 and P = 0.06, respectively), as were PPD-induced IL-10 responses (P = 0.05 at 1 years, P = 0.007 at 2 years, P = 0.003 at 3 years) and corresponding IFN-gamma responses (P = 0.05 at 6 months, P = 0.003 at 2 years, P = 0.0004 at 3 years). Increased IL-10 responses to HDM allergen were also observed throughout the observation period in CBMC from children who developed AD. CONCLUSION: Children who develop infantile AD appear to have a predisposition to respond to SEB in a Th2-dominant manner involving selective stimulation of IL-5 production. The increased IL-10 and IFN-gamma induced in response to PPD by children with AD may point to additional intrinsic differences in responses to microbial stimuli between those at high vs. those at low risk for AD, which merit more detailed investigations.

Cells, Cultured↗

PubMed2003

In vitro migration of cytotrophoblasts through a decidual endothelial cell monolayer: the role of matrix metalloproteinases.

Deficient trophoblast invasion is a major feature of pre-eclampsia. In vitro studies suggest that in normal pregnancy, maternal cells may play a role in controlling trophoblast invasion, although the exact nature of the regulatory interactions between these cells is not fully understood. To examine the effect of maternal-placental cell interactions on matrix metalloproteinase (MMP) secretion and endovascular cytotrophoblast migration in normal pregnancy and in pre-eclampsia, we performed co-culture experiments using cytotrophoblasts from normal pregnancies, together with decidual endothelial cells from both normal and preeclamptic pregnancies. Cells were incubated on semi-permeable membranes with or without phorbol 12-myristate 13-acetate (PMA). Results showed that third trimester cytotrophoblasts are migratory under basal conditions and display a different MMP profile from decidual endothelial cells. Co-culture did not damage either cell type and resulted in reduced latent MMP-9 secretion and reduced cytotrophoblast migration. Although PMA upregulated MMPs in decidual endothelial cells, it had no effect on cytotrophoblast MMP secretion. PMA, however, reduced cytotrophoblast migration. Pre-eclamptic decidual endothelial cells showed reduced MMP-1 secretion, but overall were not different in co-culture from normal endothelial cells. This study demonstrates the effectiveness of a bilayer co-culture model to study maternal-foetal cell interactions and provides evidence that maternal cells may contribute to the control of endovascular cytotrophoblast invasion.

Adult↗

PubMed2002

Striatal contribution to cognition: working memory and executive function in Parkinson's disease before and after unilateral posteroventral pallidotomy.

The basal ganglia are intimately connected to the frontal cortex via five fronto-striatal circuits. While the role of the frontal cortex in cognition has been extensively studied, the contribution of the basal ganglia to cognition has remained less clear. In Parkinson's disease, posteroventral pallidotomy (PVP) involves surgical lesioning of the internal section of the globus pallidus (GPi, the final output pathway from the basal ganglia) to relieve the motor symptoms of the disorder. PVP in Parkinson's disease provides a unique opportunity to investigate the impact of disruption of striatal outflow to the frontal cortex on cognition. We assessed executive function and working memory after withdrawal of medication in 13 patients with Parkinson's disease before and 3 months after unilateral PVP compared to 12 age- and IQ-matched normals assessed twice with an interval of 3 months. The tests used were: Wisconsin Card Sorting (WCST), Self-Ordered Random Number Sequences, Missing Digit Test, Paced Visual Serial Addition Test (PVSAT), and Visual Conditional Associative Learning Test (VCALT). After PVP, the patients performed significantly better on the Self-Ordered Random Number Sequences and the WCST, an improvement that was also observed in the normals across the two assessment and is therefore likely to reflect practice effects. Relative to the normals, the patients showed significant differential change following PVP on the Missing Digit Test and PVSAT, on which they performed worse after compared to before surgery, while the controls performed better on the second assessment. For the patients, performance on the VCALT also indicated deterioration after PVP, but the changes approached significance. The side of PVP had no effect on the results. The pattern of change observed 3 months after PVP was maintained at 15-month follow-up. The results suggest that striatal outflow to the frontal cortex may be essential for those aspects of executive function that showed deterioration after PVP.

Adult↗

PubMed2002

Presence of caprine arthritis-encephalitis virus (CAEV) infected cells in flushing media following oviductal-stage embryo collection.

To improve the knowledge on the risk of transmission of the caprine arthritis-encephalitis virus (CAEV) during embryo manipulations, we conducted a double-nested polymerase chain reaction (PCR) for CAEV proviral-DNA on flushing media recovered from the oviducts 48 h after the beginning of estrus and on blood from 89 donor does. Sixty-four does had negative blood and flushing media by PCR. Among the 25 CAEV infected goats (blood PCR positive), 11 were PCR flushing media positive (P < 0.01). Cell lysate from flushing media samples that were PCR positive were serially diluted 10 times at 1:100. Starting with the second 1:100 dilution all the cell lysate samples were PCR negative. The mean number of embryos recovered was not significantly different between goats with flushing media PCR positive and goats with flushing media PCR negative (6.0 +/- 5.4 versus 7.8 +/- 4.4, respectively; mean +/- S.D.) nor between goats with blood PCR positive and goats with blood PCR negative (7.0 +/- 5.0 versus 5.9 +/- 5.3; mean +/- S.D.). The presence of CAEV infected cells in oviductal flushing media from infected donor does was indicated for the first time during this study. The absence of flushing media PCR positive for goat blood PCR negative seemed to allow the use of the blood PCR test to confidently predict the absence of CAEV provirus in the oviductal fluid.

Animals↗

PubMed2002

Phylogenetic relationships of dengue-1 viruses from Argentina and Paraguay.

We sequenced the Capsid-pre Membrane (C/prM) and the Envelope-Nonstructural protein 1 (E/NS1) regions of 24 recent isolates of dengue-1 (DEN-1) from South America. This included 12 Argentinean and 11 Paraguayan DEN-1 strains isolated in 2000 plus a Paraguayan strain isolated in 1988. These sequences were compared with published sequences of DEN-1 isolated worldwide to determine the origin of these isolates. Pairwise comparisons of strains from Paraguay and Argentina revealed a nucleotide divergence of 0-5% in the E/NS1 region and 0-3% in the C/prM region. Our results showed that these viruses belong to the same genotype, but can be separated into two clades. Interestingly, both clades circulated simultaneously in the same geographic area during the 2000 outbreaks. Amino acid differences were found between both clades in the C/prM region at position 100 (Lys vs. Arg) and in the E/NS1 region at positions 722 (Ala vs. Thr). Although the geographic movement of DEN-1 virus can not be unequivocally traced from the genetic relationship determined here, our results suggest that the recent epidemics in Argentina and Paraguay were due to the re-emergence of a previously circulating strain, or to the virus circulating unnoticed, rather than to the introduction of a new genotype.

Amino Acid Sequence↗

PubMed2001

Heterogeneity in diphtheria-tetanus-acellular pertussis vaccine-specific cellular immunity during infancy: relationship to variations in the kinetics of postnatal maturation of systemic th1 function.

Cellular immunity to vaccines is highly variable during infancy. This study addressed the hypothesis that these responses are governed by the pace of maturational changes in adaptive immune competence, in particular, cellular functions that underlie the postnatal transition from Th2 to Th1 "bias." Tetanus-specific cytokine responses were tracked in peripheral blood mononuclear cells collected from infants at months 2, 4, 6, 12, and 18. These were compared with polyclonal responses. Results show that the Th2 component of the vaccine response develops rapidly and remains stable, unlike interferon (IFN)-gamma production, which also is initiated early but commonly declines after the final priming dose at 6 months. However, between 12 and 18 months, the IFN-gamma component of the vaccine-specific response has a spontaneous resurgence that coincides with a parallel increase in overall IFN-gamma production capacity. The Th2 component of vaccine-specific responses was more prominent in children with atopic family history.

Cohort Studies↗

PubMed2001

Analysis of trk A and p53 association.

trk A tyrosine kinase (the high affinity receptor for nerve growth factor) binds to the p53 tumour suppressor protein in vitro and in vivo. Our aim was to determine which regions of p53 are involved in trk A association. In vitro binding experiments using baculovirus expressed trk A and in vitro transcribed and translated C-terminus p53 deletion mutants show amino acids 327-338 critical for association. Also, analysis with mutants at the N-terminus, conserved regions II, III, IV and V or amino acid positions 173, 175, 181, 248 and 249 (which are amino acids frequently mutated in a variety of neoplasms and transformed cell lines), show that these sites are not involved in trk A binding. Importantly, similar results are obtained after immunoprecipitation of lysates from p53 negative fibroblasts expressing trk A and the above p53 mutant proteins. These data suggest that the amino-terminus of the oligomerisation domain of p53 is involved in p53/trk A association.

Animals↗

PubMed2001

Controlling deamidation rates in a model peptide: effects of temperature, peptide concentration, and additives.

The rate of deamidation of the Asn residue in Val-Tyr-Pro-Asn-Gly-Ala (VYPNGA), a model peptide, was determined at pH 9 (400 mM Tris buffer) as a function of temperature and peptide concentration. Over the temperature range 5-65 degrees C, deamidation followed Arrhenius behavior, with an apparent activation energy of 13.3 kcal/mol. Furthermore, increasing the peptide concentration slows the rate of deamidation. Self-stabilization with respect to deamidation has not been reported previously. The rate of deamidation was also determined in the presence of sucrose and poloxamer 407 (Pluronic F127). In both cases, the rate of deamidation was retarded by up to 40% at 35 degrees C. In aqueous solutions containing poloxamer 407, the degree of stabilization is independent of formation of a reversible thermosetting gel. With sucrose, maximum reduction in the deamidation rate was attained with as little as 5% (w/v). Addition of sucrose results in a greater conformational preference for a type II beta-turn structure, which presumably is less prone to intramolecular cyclization and subsequent deamidation.

Amides↗

PubMed2001

Phylogenetic relationships within the cyst-forming nematodes (Nematoda, Heteroderidae) based on analysis of sequences from the ITS regions of ribosomal DNA.

The ITS1, ITS2, and 5.8S gene sequences of nuclear ribosomal DNA from 40 taxa of the family Heteroderidae (including the genera Afenestrata, Cactodera, Heterodera, Globodera, Punctodera, Meloidodera, Cryphodera, and Thecavermiculatus) were sequenced and analyzed. The ITS regions displayed high levels of sequence divergence within Heteroderinae and compared to outgroup taxa. Unlike recent findings in root knot nematodes, ITS sequence polymorphism does not appear to complicate phylogenetic analysis of cyst nematodes. Phylogenetic analyses with maximum-parsimony, minimum-evolution, and maximum-likelihood methods were performed with a range of computer alignments, including elision and culled alignments. All multiple alignments and phylogenetic methods yielded similar basic structure for phylogenetic relationships of Heteroderidae. The cyst-forming nematodes are represented by six main clades corresponding to morphological characters and host specialization, with certain clades assuming different positions depending on alignment procedure and/or method of phylogenetic inference. Hypotheses of monophyly of Punctoderinae and Heteroderinae are, respectively, strongly and moderately supported by the ITS data across most alignments. Close relationships were revealed between the Avenae and the Sacchari groups and between the Humuli group and the species H. salixophila within Heteroderinae. The Goettingiana group occupies a basal position within this subfamily. The validity of the genera Afenestrata and Bidera was tested and is discussed based on molecular data. We conclude that ITS sequence data are appropriate for studies of relationships within the different species groups and less so for recovery of more ancient speciations within Heteroderidae.

Animals↗

PubMed2001

Impairment of movement initiation and execution but not preparation in idiopathic dystonia.

Imaging studies have reported impaired activation of the striatum and their frontal projection sites in dsytonia, areas which are considered to play a role in motor preparation, movement initiation and execution. The aim of this study was to investigate the processes of motor preparation, response initiation and execution in patients with idiopathic torsion dystonia (ITD). We assessed 12 patients with ITD and 12 age-matched controls on a number of reaction time (RT) tasks that differed in degree of motor preparation possible. Subjects performed a visual simple RT (SRT) task, an uncued four-choice reaction time (CRT) task and a fully precued four-choice RT task. A stimulus 1-stimulus 2 (S1-S2) paradigm was used. The warning signal/precue (S1) preceded the imperative stimulus (S2) by either 0 ms (no warning signal or precue) 200 ms, 800 ms, 1,600 ms or 3,200 ms. The patients with ITD had significantly slower RTs and movement times than normals across all RT tasks. The unwarned SRT trials were significantly faster than the uncued CRT trials for both groups. For both groups, precued CRTs were significantly faster than the uncued CRTs. The results show that while response initiation and execution are significantly slower in patients with ITD than normals, movement preparation is not quantitatively or qualitatively different. The results are discussed in relation to previous imaging, behavioural and electrophysiological studies and models of fronto-striatal dysfunction in ITD.

Adult↗

PubMed2001

Stabilization of p53 by p14ARF without relocation of MDM2 to the nucleolus.

The alternative product of the human INK4a/ARF locus, p14ARF, has the potential to act as a tumour suppressor by binding to and inhibiting the p53 antagonist MDM2. Current models propose that ARF function depends on its ability to sequester MDM2 in the nucleolus. Here we describe situations in which stabilization of MDM2 and p53 occur without relocalization of endogenous MDM2 from the nucleoplasm. Conversely, forms of ARF that do not accumulate in the nucleolus retain the capacity to stabilize MDM2 and p53. We therefore propose that nucleolar localization is not essential for ARF function but may enhance the availability of ARF to inhibit MDM2.

Cell Nucleolus↗