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Biomedical subjects

T Moore

Publications and source records attributed to T Moore.

At least 91 records · Page 5Linked to original sources
PubMed1996

Increased nailfold capillary dimensions in primary Raynaud's phenomenon and systemic sclerosis.

The aim of the study was to measure nailfold capillary dimensions and capillary density in patients with primary Raynaud's phenomenon (PRP) and systemic sclerosis (SSc) compared to control subjects. Ten controls, nine patients with PRP and 10 patients with SSc were studied. All dimensions other than distance between limbs were significantly increased in both the PRP and SSc groups compared to controls (P < 0.01), with the SSc group showing the most marked increases (SSc vs PRP, P < 0.05 for all dimensions). Capillary density was significantly reduced in the SSc group compared to controls (P = 0.004). These results suggest that structural vascular changes occur in PRP as well as in SSc, and that PRP may, therefore, not be entirely benign.

Capillaries↗
PubMed1996

Non-invasive assessment of vascular reactivity in forearm skin of patients with primary Raynaud's phenomenon and systemic sclerosis.

We have non-invasively assessed neurovascular control mechanisms in forearm skin of 10 healthy control subjects, eight patients with primary Raynaud's phenomenon (PRP) and 10 patients with systemic sclerosis (SSc) by iontophoresing acetylcholine (endothelial dependent), sodium nitroprusside (endothelial independent) and adrenaline, and measuring subsequent blood flow responses by dual-channel laser Doppler. Because basal forearm blood flow is low, adrenaline response was assessed by attenuation of reperfusion hyperaemia following 60 s of upper arm occlusion. Reperfusion hyperaemia prior to adrenaline iontophoresis differed significantly between groups (F2.21 = 4.3, P = 0.03), being lowest in the SSc and highest in the PRP group. However, the degree of attenuation of this hyperaemia by adrenaline did not differ between groups and all groups demonstrated similar vasodilatory responses to acetylcholine and to sodium nitroprusside. These findings may reflect that abnormalities in vascular tone in patients with Raynaud's phenomenon are local to the digits, or that vasoactive agents not examined in this study play a key role.

Acetylcholine↗
PubMed1996

Describing and analyzing constipation in acute care.

Many patients in acute care hospitals experience constipation, yet the literature on constipation focuses on long-term care and does not provide tools for describing and analyzing bowel management from the perspective of health care professionals or patients. The article describes the development of a bowel management task force at one acute care hospital and the initial steps taken to improve clinical quality in this area. A multifaceted approach was used to collect baseline data on practice, expectations, and problems related to bowel management. Valuable data were obtained from both patients and health care providers that have provided direction for improving clinical outcomes and patient satisfaction.

Constipation↗
PubMed1996

Growth phase-dependent transcription of the sigma(54)-dependent Po promoter controlling the Pseudomonas-derived (methyl)phenol dmp operon of pVI150.

Transcription from Pseudomonas-derived -24, -12 Po promoter of the pVI150-encoded dmp operon is mediated by the sigma 54-dependent DmpR activator in response to the presence of aromatic pathway substrates in the medium. However, global regulatory mechanisms are superimposed on this regulatory system so that the specific response to aromatic effectors is absent in cultures until the stationary phase is reached. Here we genetically dissect the system to show that the growth phase response is faithfully mimicked by a minimal system composed of the dmpR regulatory gene and the Po promoter regulatory region and can be reproduced in heterologous Escherichia coli. Using this system, we show that the growth phase-dependent DmpR-mediated response to aromatic compounds is limited to fast-growing cultures. Thus, during exponential growth of cultures in minimal media containing different carbon sources, the response to aromatics is immediate, while the response is suppressed in cultures grown on rich media until the exponential-to-stationary phase transition. Elements known to be involved in the DmpR-mediated transcription from Po were analyzed for the ability to influence the growth phase response. Most dramatically, overexpression of DmpR was shown to completely abolish the growth phase response, suggesting that a negatively acting factor may mediate this level of regulation. The possible mechanism of action and integration (of the specific regulation of the dmp operon-encoded catabolic enzymes with the physiological status of the bacteria are discussed.

Bacterial Proteins↗
PubMed1996

Greater residual vision in monkeys after striate cortex damage in infancy.

1. Monkeys with large unilateral surgical ablations of striate cortex, sustained either in adulthood or at 5-6 wk of age, were trained on an oculomotor detection and localization task and tested with visual stimuli in the hemifields ipsilateral and contralateral to the lesion 2-5 yr after surgery. 2. Monkeys with lesions sustained in adulthood were largely unable to detect stimuli in the hemifield contralateral to the lesion, with only one monkey showing recovery toward the end of testing. Monkeys with lesions of striate cortex made in infancy, however, each showed residual detection capacity at the beginning of testing and improved to near normal by the end of testing. 3. Each of the monkeys showing a residual ability to detect within the contralateral hemifield was also able to localize visual targets with eye movements. 4. These findings demonstrate that the vision surviving striate cortex damage in primates is more robust after early damage as has been shown to be the case for primary somatosensory, motor, and association cortex.

Animals↗
PubMed1996

Genetic conflict in early development: parental imprinting in normal and abnormal growth.

Parental (genomic) imprinting is the process by which the differential expression of maternal and paternal alleles at certain genetic loci in mammalian embryos occurs. Such loci are implicated in the control of fetal, placental and neonatal growth, and, more generally, in diverse aspects of fetal nutrient acquisition and maternal-fetal interactions. Not surprisingly, the aberrant expression of imprinted genes is implicated in a range of embryonic and fetal abnormalities. We outline how an evolutionary theory, based on classic parent-offspring conflict theory, relates to certain fetal growth abnormalities. In particular, we suggest that growth abnormalities resulting from the manipulation of preimplantation mammalian embryos in vitro (for example large calf syndrome) may reflect the occurrence of genetic conflict over the fetal growth programme in the early preimplantation period.

Cell Nucleus↗
PubMed1996

Evidence for a major retinitis pigmentosa locus on 19q13.4 (RP11) and association with a unique bimodal expressivity phenotype.

Retinitis pigmentosa (RP) is the name given to a heterogeneous group of retinal degenerations mapping to at least 16 loci. The autosomal dominant form (ARP), accounting for approximately 25% of cases, can be caused by mutations in two genes, rhodopsin and peripherin/RDS, and by at least six other loci identified by linkage analysis. The RP11 locus for adRP has previously been mapped to chromosome 19q13.4 in a large English family. This linkage has been independently confirmed in a Japanese family, and we now report three additional unrelated linked U.K. families, suggesting that this is a major locus for RP. Linkage analysis in the U.K. families refines the RP11 interval to 5 cM between markers D19S180 and AFMc001yb1. All linked families exhibit incomplete penetrance; some obligate gene carriers remain asymptomatic throughout their lives, whereas symptomatic individuals experience night blindness and visual field loss in their teens and are generally registered as blind by their 30s. This "bimodal expressivity" contrasts with the variable-expressivity RP mapping to chromosome 7p (RP9) in another family, which has implications for diagnosis and counseling of RP11 families. These results may also imply that a proportion of sporadic RP, previously assumed to be recessive, might result from mutations at this locus.

Chromosome Mapping↗
PubMed1995

Localization of visual stimuli after striate cortex damage in monkeys: parallels with human blindsight.

Blindsight is a phenomenon in which human patients with damage to striate cortex deny any visual sensation in the resultant visual field defect but can nonetheless detect and localize stimuli when persuaded to guess. Although monkeys with striate lesions have also been shown to exhibit some residual vision, it is not yet clear to what extent the residual capacities in monkeys parallel the phenomenon of human blindsight. To clarify this issue, we trained two monkeys with unilateral lesions of striate cortex to make saccadic eye movements to visual targets in both hemifields under two conditions. In the condition analogous to clinical perimetry, they failed to initiate saccades to targets presented in the contralateral hemifield and thus appeared "blind." Only in the condition where the fixation point was turned off simultaneously with the onset of the target--signaling the animal to respond at the appropriate time--were monkeys able to localize targets contralateral to the striate lesion. These results indicate that the conditions under which residual vision is demonstrable are similar for monkeys with striate cortex damage and humans with blindsight.

Animals↗
PubMed1995

Transplantable NK cell progenitors in murine bone marrow.

Differentiation of NK cells from pluripotent hematopoietic stem cells is a poorly understood process. Although it is known that NK cells are bone marrow derived and dependent upon an intact bone marrow microenvironment for complete maturation, it is not known if they arise from an intermediate lymphoid stem cell or from progenitors exclusively committed to the NK lineage. To determine whether phenotypically distinct committed NK progenitor cells exist in murine bone marrow, we sorted cells capable of repopulating recipient mice with mature NK cells upon i.v. transfer. We identified a rare population of bone marrow cells with the phenotype Ly6+ Lin- c-kit+ CD43high Fall-3high TSA-1- AA4.1low Rh123high that is highly enriched for the ability to generate NK cells after transplantation. Although these cells are relatively depleted of Rh123low pluripotent stem cells, they are highly enriched for both lymphoid and myeloid repopulating ability. Thus, we have found no evidence to support the existence of a phenotypically distinct transplantable progenitor population in mouse bone marrow that is either exclusively committed to the NK cell lineage or exhibits the functional characteristics of a common lymphoid stem cell.

Animals↗
PubMed1995

Phenylacetate synergizes with retinoic acid in inducing the differentiation of human neuroblastoma cells.

Phenylacetate, a natural metabolite of phenylalanine which was originally described as a plant growth hormone, has recently gained attention as a possible differentiation inducer for a variety of human tumor cell types. This interest prompted us to assess the ability of sodium phenylacetate (NaPA) to promote the differentiation of human neuroblastoma cells, both alone and in combination with retinoic acid (RA), a known inducer of neuroblastoma differentiation and maturation. Using the LA-N-5 cell line, we have determined that NaPA can stimulate the differentiation of neuroblastoma cells, as evidenced by dose-dependent inhibition of cell proliferation, neurite outgrowth, increased acetylcholinesterase activity and reduction of N-myc expression. Furthermore, NaPA and RA synergized in inducing differentiation, in that combination treatment resulted in cessation of cell growth along with morphologic and biochemical changes indicative of the loss of malignant properties. We have determined that NaPA can markedly enhance mRNA levels of the nuclear RA receptor-beta (RAR beta) in LA-N-5 cells prior to morphologic or other phenotypic changes induced by this compound. This effect appeared to be distinct from the ability of NaPA to alter tumor cell lipid metabolism via inhibition of protein isoprenylation. Thus among its varied effects on LA-N-5 cells, NaPA appears to interact with the RA pathway at the nuclear level by up-regulating RAR beta expression.

Cell Differentiation↗
PubMed1995

Genetic conflict and evolution of mammalian X-chromosome inactivation.

The existence of parentally imprinted gene expression in the somatic tissues of mammals and plants can be explained by a theory of intragenomic genetic conflict, which is a logical extension of classical parent-offspring conflict theory. This theory unites conceptually the phenomena of autosomal imprinting and X-chromosome inactivation. We argue that recent experimental studies of X-chromosome inactivation and androgenetic development address previously published predictions of the conflict theory, and we discuss possible explanations for the occurrence of random X-inactivation in the somatic tissues of eutherians.

Animals↗
PubMed1995

Post-operative problems following anterior cruciate ligament reconstruction.

Seventy adult patients were studied during the postoperative rehabilitation period following anterior cruciate ligament reconstruction in order to investigate the role of pre-, intra-, and postoperative factors in range of motion and graft problems. A standard bone-patellar tendon-bone autograft was used for the reconstruction. Pre- and intraoperative factors such as concomitant injuries, time from injury to surgery, age, sex, and tunnel placement were recorded. Tunnel placement was recorded on intraoperative radiographs of the final guide pin placement and compared to pin placement on cadaver knees. The results indicated a significant relation between early reconstruction (< 1 month) following the injury and range of motion problems during the early rehabilitation period (P < 0.001). This relation disappeared by the end of the first postoperative year. Prolonged surgery was also associated with early motion problems (P < 0.05). Graft laxity or failure was correlated with an earlier return of range of motion (P < 0.05). We hypothesized that graft failure can have a biologic cause rather than a mechanical one since intraoperative X-rays indicated a near-anatomic tunnel placement in this patient group when compared to ideal placement in the cadaver knees.

Adolescent↗
PubMed1995

Sustained-release transdermal glyceryl trinitrate patches as a treatment for primary and secondary Raynaud's phenomenon.

A randomized, double-blind, placebo controlled, cross-over study was conducted to determine the clinical efficacy of and patient tolerance to sustained-release glyceryl trinitrate (GTN) patches in the treatment of Raynaud's phenomenon. The patients studied were those with primary Raynaud's disease (n = 21) and patients with Raynaud's phenomenon secondary to systemic sclerosis (n = 21). GTN patches (0.2 mg/h) were found to be effective in reducing the number (P < 0.05) and severity of Raynaud's attacks (P < 0.05) in both groups of patients. Objective assessments by infrared thermography did not show any significant improvement when the patients were on GTN patches (P > 0.05). Headaches, refractory to treatment, led to the withdrawal of eight patients from the study and occurred in approximately 80% of the remaining patients. Thus, in spite of the subjective efficacy, the frequent headaches will limit the use of GTN patches in Raynaud's phenomenon. Elucidating the mechanism of action of the beneficial and adverse effects of GTN at the molecular level may shed light on the pathogenesis of Raynaud's phenomenon and its treatment.

Administration, Cutaneous↗