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T Moore

Publications and source records attributed to T Moore.

At least 73 records · Page 4Linked to original sources
PubMed1999

The intercellular adhesion molecule type-1 is required for rapid activation of T helper type 1 lymphocytes that control early acute phase of genital chlamydial infection in mice.

Recent studies in animal models of genital chlamydial disease revealed that early recruitment of dendritic cells and specific T helper type-1 (Th1) cells into the genital mucosae is crucial for reducing the severity of the acute phase of a cervico-vaginal infection and arresting ascending disease. These immune effectors are therefore important for preventing major complications of genital chlamydial infection. Other in vitro studies showed that intercellular adhesion molecule-1 (ICAM-1) plays a role in the antichlamydial action of specific CD4+ and CD8+ T cells. In the present study, we investigated the clinicopathological consequences of ICAM-1 deficiency during chlamydial genital infection in ICAM-1 knockout (ICAM-1KO) mice, and analysed the cellular and molecular immunological bases for any observed pathology or complication. Following a primary genital infection of female ICAM-l-/- and ICAM-1+/+ mice, the intensity of the disease during the first 3 weeks (as assessed by shedding of chlamydiae in the genital tract) was significantly greater in ICAM-1KO mice than in ICAM-1+/+ mice (P < 0.0001), although both ICAM-l-/- and ICAM-1+/+ mice subsequently cleared the primary infection. There was greater ascending disease during the initial stage of the infection, and a higher incidence of tubal disease (hydrosalpinx formation) after multiple infections in ICAM-l-/- mice. Analysis of the cellular and molecular bases for the increased acute and ascending disease in ICAM-l-/- mice revealed that the high affinity of ICAM-1 for leucocyte function antigen type-1 is a property that promotes rapid activation of specific Th1 cells, as well as their early recruitment into the genital mucosa. Moreover, ICAM-1 was more important for naive T-cell activation than primed Th1 cells, although its absence delayed or suppressed immune T-cell activation by at least 50%. Taken together, these results indicated that ICAM-1 is crucial for rapid T-cell activation, early recruitment and control of genitally acquired Chlamydia trachomatis.

Acute Disease↗
PubMed1999

Missense mutations in the most ancient residues of the PAX6 paired domain underlie a spectrum of human congenital eye malformations.

Mutations of the human PAX6 gene underlie aniridia (congenital absence of the iris), a rare dominant malformation of the eye. The spectrum of PAX6 mutations in aniridia patients is highly biased, with 92% of all reported mutations leading to premature truncation of the protein (nonsense, splicing, insertions and deletions) and just 2% leading to substitution of one amino acid by another (missense). The extraordinary conservation of the PAX6 protein at the amino acid level amongst vertebrates predicts that pathological missense mutations should in fact be common even though they are hardly ever seen in aniridia patients. This indicates that there is a heavy ascertainment bias in the selection of patients for PAX6 mutation analysis and that the 'missing' PAX6 missense mutations frequently may underlie phenotypes distinct from textbook aniridia. Here we present four novel PAX6 missense mutations, two in association with atypical phenotypes: ectopia pupillae (displaced pupils) and congenital nystagmus (searching gaze), and two in association with more recognizable aniridia phenotypes. Strikingly, all four mutations are located within the PAX6 paired domain and affect amino acids which are highly conserved in all known paired domain proteins. Our results support the hypothesis that the under-representation of missense mutations is caused by ascertainment bias and suggest that a substantial burden of PAX6 -related disease remains to be uncovered.

Amino Acid Sequence↗
PubMed1999

Anatomy of the distal knee joint and pyarthrosis following external fixation.

OBJECTIVE: To determine the limits of the distal synovial reflection of the human knee joint. SPECIMENS: Six paired knees studied by magnetic resonance imaging (MRI), fluoroscopic arthrography, and gross dissection. The right knees of five patients with chronic idiopathic knee effusions were studied by MRI. Cadaveric knees were injected with saline prior to MRI. The joint capsules were dissected to visualize local anatomy and check for capsular tears. In each modality (MRI, fluoroscopy, and dissection), the most distal extent of knee synovial fluid was measured. RESULTS: The right versus left agreement for paired specimens was generally two to three millimeters. Some specimens showed asymmetric capsular reflection. Medial fluid was identified at distances greater than forty-nine millimeters from the subchondral bone in seven knees and less than fifteen millimeters in four knees (range 0 to 70 millimeters, mean thirty-three millimeters). Laterally, the range was ten to thirty-five millimeters (mean twenty-three millimeters). In six of the twelve cadaveric specimens, there was evidence of a communication between the knee joint and the proximal tibiofibularjoint. In the knees of volunteers, joint fluid tracked medially to a range of ten to fifty millimeters and laterally to a range of six to fifteen millimeters, with means of twenty-six and eleven millimeters, respectively. The knees of the volunteers had no evidence of tibiofibular joint communication with the knee. CONCLUSION: Insertion of external fixation pins within sixty to seventy millimeters of the proximal articular surface of the tibia is associated with a high probability of synovial penetration and possibly provides a conduit for the introduction of bacteria, which may be etiologic in iatrogenic pyarthrosis.

Adult↗
PubMed1999

The "distal-dorsal difference" as a possible predictor of secondary Raynaud's phenomenon.

OBJECTIVE: To investigate the possibility that a hand distal-dorsal difference in temperature of greater than 1 degree C (fingers colder than the dorsum) at a room temperature of 30 degrees C is a good predictor of secondary Raynaud's phenomenon (RP). METHODS: We imaged the hands of patients with primary Raynaud's phenomenon (PRP) and systemic sclerosis (SSc) using a thermal camera at room temperatures of 23 and 30 degrees C. From these images we measured the distal-dorsal difference in temperature for all fingers excluding the thumbs. At a room temperature of 23 degrees C we also performed a cold challenge test using water at 15 degrees C for 1 min and thermally imaged the rewarming process for 15 min. Several variables were derived from the rewarming curve. The procedure was repeated within 3 days to assess reproducibility. RESULTS: The best discriminator between PRP and SSc was found to be a distal-dorsal difference of > 1 degree C at 30 degrees C (p = 0.005). There is reasonable reproducibility when considering groups of patients. However, the intra-subject standard deviations were large, indicating that measurements for the same patient on separate visits may vary considerably. CONCLUSION: Our results suggest that the finding of a distal-dorsal difference of > 1 degree C (cold fingers) at 30 degrees C in a patient with RP is specific for underlying connective tissue disease.

Adolescent↗
PubMed1999

Genetic analysis of the guanylate cyclase activator 1B (GUCA1B) gene in patients with autosomal dominant retinal dystrophies.

The guanylate cyclase activator proteins (GCAP1 and GCAP2) are calcium binding proteins which by activating Ret-GC1 play a key role in the recovery phase of phototransduction. Recently a mutation in the GUCA1A gene (coding for GCAP1) mapping to the 6p21.1 region was described as causing cone dystrophy in a British family. In addition mutations in Ret-GC1 have been shown to cause Leber congenital amaurosis and cone-rod dystrophy. To determine whether GCAP2 is involved in dominant retinal degenerative diseases, the GCAP2 gene was screened in 400 unrelated subjects with autosomal dominant central and peripheral retinal dystrophies. A number of changes involving the intronic as well as the coding sequence were observed. In exon 1 a T to C nucleotide change was observed leaving the tyrosine residue 57 unchanged. In exon 3 a 1 bp intronic insertion, a single nucleotide substitution G to A in the intron 3' of this exon, and a GAG to GAT change at codon 155 were observed. This latter change results in a conservative change of glutamic acid to aspartic acid. In exon 4 a 7 bp intronic insertion, a single nucleotide A to G substitution in the intron 5' of this exon, and a single base pair change C to G in the intron 3' of exon 4 were seen. None of these changes would be expected to affect correct splicing of this gene. All these changes were observed in controls. The results of this study do not show any evidence so far that GCAP2 is involved in the pathogenesis of autosomal dominant retinal degeneration in this group of patients. All the changes detected were found to be sequence variations or polymorphisms and not disease causing.

Calcium-Binding Proteins↗
PubMed1998

Genomic organization and partial duplication of the human alpha7 neuronal nicotinic acetylcholine receptor gene (CHRNA7).

The human alpha7 neuronal nicotinic acetylcholine receptor gene (HGMW-approved symbol CHRNA7) has been characterized from genomic clones. The gene is similar in structure to the chick alpha7 gene with 10 exons and conserved splice junction positions. The size of the human gene is estimated to be larger than 75 kb. A putative promoter 5' of the translation start in exon 1 has been cloned and sequenced. The promoter region lacks a TATA box and has a high GC content (77%). Consensus Sp1, AP-2, Egr-1, and CREB transcription factor binding sites appear to be conserved between bovine and human genes. The alpha7 nAChR gene was found to be partially duplicated, with both loci mapping to the chromosome 15q13 region. A yeast artificial chromosome contig was constructed over a genetic distance of 5 cM that includes both alpha7 loci and the region between them. Four novel exons are described, located in genomic clones containing the partially duplicated gene. The duplicated sequences, including the novel exons, are expressed in human brain.

Base Sequence↗
PubMed1998

Visual representations during saccadic eye movements.

In normal vision, shifts of attention are usually followed by saccadic eye movements. Neurons in extrastriate area V4 are modulated by focal attention when eye movements are withheld, but they also respond in advance of visually guided saccadic eye movements. We have examined the visual selectivity of saccade-related responses of area V4 neurons in monkeys making delayed eye movements to receptive field stimuli of varying orientation. This task did not require the monkey to attend to orientation per se but merely to foveate the receptive field stimulus. We present evidence that the presaccadic enhancement exhibited by V4 neurons, quite separate from the response at stimulus onset, is a resurgent visual representation that seems as selective as the response is when the stimulus first appears. The presaccadic enhancement appears to provide a strengthening of a decaying featural representation immediately before an eye movement is directed to visual targets. We suggest that this reactivation provides a mechanism by which a clear perception of the saccade goal can be maintained during the execution of the saccade, perhaps for the purpose of establishing continuity across eye movements.

Animals↗
PubMed1998

Further investigation of a chromosome 15 locus in schizophrenia: analysis of affected sibpairs from the NIMH Genetics Initiative.

Linkage of a neurophysiological deficit associated with schizophrenia, i.e., the failure to inhibit the auditory P50 response, was previously reported at chromosome 15q14. The marker with the highest pairwise lod score, D15S1360, was isolated from a yeast artificial chromosome containing a candidate gene, the alpha7-nicotinic acetylcholine receptor gene. In the present study, this linkage was further investigated in a subset of the NIMH Genetics Initiative schizophrenia families. These families have not been studied neurophysiologically, as were the families in the original report. Therefore, the DSMIII-R diagnosis of schizophrenia was used as the affected phenotype. Twenty families fulfilled the criteria of at least one sibpair concordant for schizophrenia, along with their two parents or another affected relative outside the nuclear family, available for genotyping. Sibpair analysis showed a significant proportion of D15S1360 alleles shared identical-by-descent (0.58; P < 0.0024). The results further support the involvement of this chromosomal locus in the genetic transmission of schizophrenia.

Chromosomes, Human, Pair 15↗
PubMed1998

DMSO produces a new subgel phase in DPPC: DSC and X-ray diffraction study.

Equilibrium phases and the kinetics of subgel phase transformation of dipalmitoylphosphatidylcholine (DPPC) hydrated with mixtures of dimethylsulfoxide (DMSO)/water have been studied using differential scanning calorimetry (DSC) and X-ray diffraction (XRD). The rate of gel-to-subgel transformation is decreased with a small increase in X, the DMSO/water mole fraction, but then speeds up and becomes faster than in pure water by X = 0.16. The DSC scans show multiple subgel peaks, some of which can be attributed to impacted domain growth. For X greater than 0.10, XRD shows that there is a new, stable subgel phase, S, which also accounts for some of the multiplicity of DSC peaks. Our electron density profiles show that the thickness of the bilayer in the S phase is greater than in the usual C subgel phase. We suggest that the S subgel phase is characterized by different headgroup ordering and smaller chain tilt angle than in the C subgel phase. Electron density profiles show that increasing X decreases the water space between bilayers in all phases, subgel, gel and fluid (L alpha). For X = 0.20, a different gel phase is also observed that may be due to subtle changes in the orientation of chain tilt first observed in partially dehydrated DMPC. The dehydrating effect of DMSO explains the results of a previous study, confirmed in this study, that increasing the concentration of DMSO raises the main transition temperature and eliminates the ripple phase.

1,2-Dipalmitoylphosphatidylcholine↗
PubMed1998

Tumor remnants within giant cells following irradiation of cutaneous squamous cell carcinoma.

BACKGROUND: The histopathologic effects of curative doses of radiation therapy on cutaneous squamous cell carcinoma (SCC) have not been well described in the dermatologic literature. OBJECTIVE: To understand the histopathologic process of cutaneous SCC involution following radiation treatment. METHODS: Hematoxylin-eosin stain and immunoperoxidase stains for keratin were performed on tissue from the site of a primary cutaneous SCC 2 months after completion of fractionated radiation therapy (7000 cGy total) but prior to clinical involution. RESULTS: Histopathological examination of the irradiated SCC revealed dermal keratin pearls and keratinocytic necrosis resembling apoptosis as well as inflammation and foreign body giant cell reaction. Immunoperoxidase staining for keratin revealed cellular remnants of cutaneous SCC without intact keratinocytic nuclei within giant cells. CONCLUSION: Complete clinical resolution of the SCC over the next several weeks without recurrence after 15 months confirmed the histopathologic findings of tumor destruction by primary radiation therapy.

Aged↗
PubMed1998

A cellular protein binds vaccinia virus late promoters and activates transcription in vitro.

Available evidence indicates that the transcription of the late class of vaccinia virus genes requires the participation of several virus-encoded proteins in addition to the viral RNA polymerase. In this report we describe the identification of a protein present in extracts of uninfected HeLa cells that binds avidly to viral late promoter DNA. The protein bound specifically to several different vaccinia virus late promoters but not an early nor an intermediate promoter. DNase I footprinting localized the protein's binding site to nucleotides surrounding the transcriptional start site of the I1L promoter. Optimal promoter binding required sequences in the highly conserved TAAAT motif at the transcriptional start site as well as sequences immediately upstream; however, one variation on the motif's sequence did not affect promoter binding by the protein. Partially purified late promoter binding protein (LPBP) was capable of stimulating the transcription activity of extracts depleted of LPBP on a late promoter-driven template, establishing LPBP as a transcription activator in vitro. These results suggest that a cellular protein is responsible for targeting vaccinia virus late promoters for initiation of transcription.

Binding Sites↗
PubMed1998

Altered imprinted gene methylation and expression in completely ES cell-derived mouse fetuses: association with aberrant phenotypes.

In vitro manipulation of preimplantation mammalian embryos can influence differentiation and growth at later stages of development. In the mouse, culture of embryonic stem (ES) cells affects their totipotency and may give rise to fetal abnormalities. To investigate whether this is associated with epigenetic alterations in imprinted genes, we analysed two maternally expressed genes (Igf2r, H19) and two paternally expressed genes (Igf2, U2af1-rs1) in ES cells and in completely ES cell-derived fetuses. Altered allelic methylation patterns were detected in all four genes, and these were consistently associated with allelic changes in gene expression. All the methylation changes that had arisen in the ES cells persisted on in vivo differentiation to fetal stages. Alterations included loss of methylation with biallelic expression of U2af1-rs1, maternal methylation and predominantly maternal expression of Igf2, and biallelic methylation and expression of Igf2r. In many of the ES fetuses, the levels of H19 expression were strongly reduced, and this biallelic repression was associated with biallellic methylation of the H19 upstream region. Surprisingly, biallelic H19 repression was not associated with equal levels of Igf2 expression from both parental chromosomes, but rather with a strong activation of the maternal Igf2 allele. ES fetuses derived from two of the four ES lines appeared developmentally compromised, with polyhydramnios, poor mandible development and interstitial bleeding and, in chimeric fetuses, the degree of chimerism correlated with increased fetal mass. Our study establishes a model for how early embryonic epigenetic alterations in imprinted genes persist to later developmental stages, and are associated with aberrant phenotypes.

Alleles↗
PubMed1998

Thermography and nailfold capillaroscopy as noninvasive measures of circulation in children with Raynaud's phenomenon.

OBJECTIVE: To determine in a pilot study the feasibility of noninvasive techniques of (a) measurement of rewarming response after a standard cold challenge test (using thermographic imaging) and (b) measurement of nailfold capillary dimensions using video capillaroscopy, in the assessment of children presenting with Raynaud's phenomenon (RP). METHODS: Ten children with RP and 10 age matched healthy controls were studied. No child had definite evidence of underlying connective tissue disease. RESULTS: Children with RP had abnormal rewarming curves. The gradient of the rewarming curve was significantly lower in children with RP (median 1.5 vs 5.0 degrees C/min in controls; p = 0.015), and there was a trend for the lag time (the interval between the end of the cold challenge and the onset of rewarming) to be increased in children with RP (median 4.7 vs 0.5 min in controls; p = 0.08). Capillary dimensions were measured in 7 of the children with RP, and were similar to those of healthy controls. CONCLUSION: Thermography and nailfold capillaroscopy are feasible in children and should be further evaluated.

Adolescent↗
PubMed1997

Multiple imprinted sense and antisense transcripts, differential methylation and tandem repeats in a putative imprinting control region upstream of mouse Igf2.

The mouse insulin-like growth factor 2 (Igf2) locus is a complex genomic region that produces multiple transcripts from alternative promoters. Expression at this locus is regulated by parental imprinting. However, despite the existence of putative imprinting control elements in the Igf2 upstream region, imprinted transcriptional repression is abolished by null mutations at the linked H19 locus. To clarify the extent to which the Igf2 upstream region contains autonomous imprinting control elements we have performed functional and comparative analyses of the region in the mouse and human. Here we report the existence of multiple, overlapping imprinted (maternally repressed) sense and antisense transcripts that are associated with a tandem repeat in the mouse Igf2 upstream region. Regions flanking the repeat exhibit tissue-specific parental allelic methylation patterns, suggesting the existence of tissue-specific control elements in the upstream region. Studies in H19 null mice indicate that both parental allelic methylation and monoallelic expression of the upstream transcripts depends on an intact H19 gene acting in cis. The homologous region in human IGF2 is structurally conserved, with the significant exception that it does not contain a tandem repeat. Our results support the proposal that tandem repeats act to target methylation to imprinted genetic loci.

Alleles↗
PubMed1997

Hadamard conjugations and modeling sequence evolution with unequal rates across sites.

This paper considers the many different distributions that may approximate the distribution of site rates in DNA sequences and shows how the Hadamard conjugation may be modified to take these into account. This is done for both 2-state and 4-state data. Distributions which give simple closed forms include the gamma (gamma) distribution, the inverse Gaussian distribution (which is similar to the lognormal), and a mixture of either of these with a proportion of sites which cannot change (invariant sites). It is seen that the tail of a distribution can have major effects upon the coefficient of variation of site rates. Because the Hadamard conjugation can be used to either correct data or predict the data given the model (i.e., the likelihood of site patterns), light is shed on properties of maximum likelihood tree selection with unequal site rates. Analysis of rRNA shows how unequal rates across sites can change the optimal tree. Maximum likelihood analysis also shows that distinct distributions fit each data set, with the gamma often not being the best. Analyzing both these data and a long stretch of primate mtDNA reveals evidence of many "hidden" multiple substitutions, while signals not corresponding to the preferred biological tree generally decrease an unequal rates are allowed for. Last, we discuss the expected behavior of sequences evolving by models where stabilizing selection alone explains unequal site rates. Such models do not explain "synapomorphies" or informative changes in ancient molecules, because while stabilizing selection can vastly decrease change at a site, it will also vastly accelerate back-substitution (leaving only a covarion model to explain old synapomorphies). When and why models allowing a continuous distribution of site rates (e.g., gamma) will approximate covarion evolution requires further study.

Algorithms↗
PubMed1997

Functional characterization of equine neutrophils in response to calcium ionophore A23187 and phorbol myristate acetate ex vivo.

Equine neutrophils (PMN) play a critical role in inflammatory processes in horses. The objective of this study was to characterize equine PMN function ex vivo following stimulation with calcium ionophore A23187 (A23187) and phorbol myristate acetate (PMA). These stimulants trigger different branches of the PMN activation process that occurs in vivo. Equine PMN were isolated from the whole blood of six clinically normal geldings using a one-step discontinuous Percoll gradient technique. Neutrophil aggregation, degranulation, and superoxide anion production were evaluated in assay systems which had previously been established to quantitate PMN function. Dose-response curves for A23187 and PMA were derived for the three functions. Results indicate that equine PMN aggregation and superoxide anion production are more responsive to activation by PMA as the maximum change in percent transmittance and maximum nanomoles of superoxide anion produced following PMA stimulation (60.8% and 10.4 nmol per 10(6) cells, respectively) were greater than those values stimulated by A23187 (41.5% and 5.2 nmol per 10(6) cells, respectively). However, degranulation was found to be more responsive to A23187 stimulation (maximum percent degranulation: 56.1%) than to PMA stimulation (maximum percent degranulation: 30.7%). Dose-response curves following A23187 and PMA stimulation revealed that superoxide anion production had the lowest threshold concentration among the three functions. Degranulation had the highest threshold concentration among the three functions for both stimulants. Results indicate that equine PMN functions differ in their dependence on second messengers in the activation pathway. These functions also occur in a dose-dependent manner and differ in the threshold concentrations required for their stimulation.

Animals↗