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J Nicholson

Publications and source records attributed to J Nicholson.

At least 37 records · Page 2Linked to original sources
PubMed2000

Estimating Scandinavian and Gaelic ancestry in the male settlers of Iceland.

We present findings based on a study of Y-chromosome diallelic and microsatellite variation in 181 Icelanders, 233 Scandinavians, and 283 Gaels from Ireland and Scotland. All but one of the Icelandic Y chromosomes belong to haplogroup 1 (41.4%), haplogroup 2 (34.2%), or haplogroup 3 (23.8%). We present phylogenetic networks of Icelandic Y-chromosome variation, using haplotypes constructed from seven diallelic markers and eight microsatellite markers, and we propose two new clades. We also report, for the first time, the phylogenetic context of the microsatellite marker DYS385 in Europe. A comparison of haplotypes based on six diallelic loci and five microsatellite loci indicates that some Icelandic haplogroup-1 chromosomes are likely to have a Gaelic origin, whereas for most Icelandic haplogroup-2 and -3 chromosomes, a Scandinavian origin is probable. The data suggest that 20%-25% of Icelandic founding males had Gaelic ancestry, with the remainder having Norse ancestry. The closer relationship with the Scandinavian Y-chromosome pool is supported by the results of analyses of genetic distances and lineage sharing. These findings contrast with results based on mtDNA data, which indicate closer matrilineal links with populations of the British Isles. This supports the model, put forward by some historians, that the majority of females in the Icelandic founding population had Gaelic ancestry, whereas the majority of males had Scandinavian ancestry.

Alleles↗
PubMed2000

Long-term photoepilation using a broad-spectrum intense pulsed light source.

BACKGROUND: The goal of laser or flashlamp photoepilation is to produce long-term, cosmetically significant hair removal. We document the long-term efficacy achieved with an intense pulsed light source for photoepilation. DESIGN: Prospective study comparing long-term results of single vs multiple treatments, and effects of anatomic site and skin type on efficacy of photoepilation with a device emitting broad-spectrum, noncoherent (nonlaser) radiation from 550- to 1200-nm wavelengths, in macropulses divided into 2 to 5 minipulses. SETTING: Private dermatology practice. PATIENTS: Thirty-four patients (8 men, 26 women) with hirsutism. INTERVENTIONS: Parameters for the study were wavelength of 615 to 695 nm, pulse duration of 2.6 to 3.3 milliseconds, fluence of 34 to 42 J/cm(2), 10 x 45-mm exposure field, and application of 1 degrees C cooling gel. MAIN OUTCOME MEASURES: Hair removal efficiency, calculated as percentage ratio of the number of hairs present compared with baseline counts, and patient satisfaction questionnaire completed at last follow-up. RESULTS: The mean hair removal efficiency achieved was 76% after a mean of 3.7 treatments. More than 94% of the sites reached mean hair removal efficiency values greater than 50%. Hair removal efficiency was not significantly related to skin type, hair color, anatomic site, or number of treatments. Side effects were mild and reversible and occurred in a minority of patients (hyperpigmentation in 3 and superficial crusting in 2). CONCLUSIONS: Our data document the long-term clinical efficacy of intense pulsed light source-induced hair removal in light and dark skin phenotypes. Maximal photoepilation was achieved from the initial 1 to 3 treatments; only a small added benefit was seen after more treatments.

Adolescent↗
PubMed2000

An evaluation of lycra garments in the lower limb using 3-D gait analysis and functional assessment (PEDI).

Whole body lycra garments were assessed in eight children using gait analysis, the paediatric evaluation of disability index (PEDI), and a questionnaire of parental acceptance. Seven of the children had cerebral palsy and one Duchennes muscular dystrophy. After initial assessment and fitting of the garment, there was a 2-week introduction period followed by 6 weeks of wearing the garment for at least 6 h everyday, following which they were re-assessed. The root mean square error (RMSE) was used as a measure of variability over three separate passes through the gait laboratory and was a reference figure for gait stability. Proximal stability around the pelvis improved for five children and distal stability improved for three. Five children improved in at least one aspect of the PEDI scale. Although the parents and children detected these improvements, they did not outweigh the disadvantages of wearing the suit and as a consequence only one out of eight families considered continuing with the lycra garment.

Cerebral Palsy↗
PubMed2000

A Brg1 null mutation in the mouse reveals functional differences among mammalian SWI/SNF complexes.

Mammalian SWI/SNF complexes utilize either brahma (Brm) or brahma-related gene 1 (Brg1) catalytic subunits to remodel nucleosomes in an ATP-dependent manner. Brm was previously shown to be dispensable, suggesting that Brm and Brg1 are functionally redundant. To test this hypothesis, we have generated a Brg1 null mutation by gene targeting, and, surprisingly, homozygotes die during the periimplantation stage. Furthermore, blastocyst outgrowth studies indicate that neither the inner cell mass nor trophectoderm survives. However, experiments with other cell types demonstrate that Brg1 is not a general cell survival factor. In addition, Brg1 heterozygotes are predisposed to exencephaly and tumors. These results provide evidence that biochemically similar chromatin-remodeling complexes have dramatically different functions during mammalian development.

Animals↗
PubMed2000

An intervention programme to establish regular toothbrushing: understanding parents' beliefs and motivating children.

AIMS/OBJECTIVES: To determine the benefit of twice daily toothbrushing on newly erupted first permanent molars. To investigate, through the Health Belief Model, how parents' beliefs influence the likelihood of their children brushing twice a day. To identify aspects of a toothbrushing intervention programme that can be used in general dental practice. DESIGN: Randomised controlled trial. SETTING: Schools in deprived communities in Scotland. PARTICIPANTS: 461, 5-year-old children. INTERVENTIONS/METHODS: Supervised toothbrushing on school-days with a 1,000 ppm chalk-based fluoride toothpaste for two years. A school and home-based incentive scheme including toothbrushing charts, 6-monthly dental examinations and parental questionnaires. MAIN OUTCOME MEASURES: Caries increment and twice daily toothbrushing. RESULTS: In the control group, children who brushed once a day or less had 64% more caries than those who brushed at least twice a day (P = 0.001). In the intervention group this difference in caries was reduced to 16% (P > 0.05). The most significant parental belief explaining variation in twice-daily brushing was whether parents feel strongly that there is time to check their child's toothbrushing (P = 0.0001). The odds of these parents reporting that their child brushes twice daily are nearly three times greater. 95% of parents felt that toothbrushing charts would be a good way for dentists in practice to encourage children to brush regularly. CONCLUSIONS: The benefit of twice daily toothbrushing on caries development in newly erupted first permanent molar teeth is around 50% compared to brushing once a day or less. Parents' beliefs do influence the likelihood of their children brushing twice a day. Key parts of the intervention programme can be used when children attend general dental practice and would be welcomed by parents.

Behavior Therapy↗
PubMed2000

Imbalances of chromosome 17 in medulloblastomas determined by comparative genomic hybridisation and fluorescence in situ hybridisation.

AIMS: To investigate the status of chromosome 17 in a series of medulloblastomas using comparative genomic hybridisation (CGH) and fluorescence in situ hybridisation (FISH). METHODS: Frozen tissue and formalin fixed, paraffin was embedded tissue from 27 medulloblastomas were analysed by CGH and FISH, respectively. CGH ratio profiles for chromosome 17 were compared with the results of FISH, for which loss or gain of 17p or 17q was assessed in two distinct ways using a combination of differentially labelled subtelomeric and centromeric probes and analysing 200 nuclei in each tumour. RESULTS: CGH revealed imbalances consistent with isochromosome 17q in eight of 27 tumours. Either loss of 17p or gain of 17q was identified in a further nine tumours, whereas 10 tumours were apparently balanced. Using control results from preparations of paraffin wax embedded tonsils, thresholds for the detection of abnormalities by FISH were established, either by determining the dominant pattern of signals in each case, or the mean ratio of subtelomeric to centromeric signals. Results by CGH and FISH were concordant in 21 of 27 tumours. In the remainder, most discrepancies related to methodological differences. CONCLUSIONS: CGH has a role in disclosing common, genome wide chromosomal gains or losses in tumours, the clinical relevance of which can then be studied in large archival series of paraffin wax embedded tumours using FISH.

Adolescent↗
PubMed2000

Procedurally similar competitive immunoassay systems for the serodiagnosis of Babesia equi, Babesia caballi, Trypanosoma equiperdum, and Burkholderia mallei infection in horses.

Procedurally similar competitive enzyme-linked immunoassay (cELISA) methods were developed for the serodiagnosis of Babesia equi and Babesia caballi (piroplasmosis), Trypanosoma equiperdum (dourine), and Burkholderia mallei (glanders) infections in horses. Apparent test specificities for the B. equi, B. caballi, T. equiperdum, and B. mallei cELISAs were 99.2%, 99.5%, 98.9%, and 98.9%, respectively. Concordances and kappa values between the complement fixation (CF) and the cELISA procedures for the serodiagnosis of B. equi, B. caballi, T. equiperdum, and B. mallei infections in experimentally exposed horses were 76% and 0.55, 89% and 0.78, 97% and 0.95, and 70% and 0.44, respectively. The cELISA method may be a technically more reproducible, objective, and convenient approach for piroplasmosis, dourine, and glanders serodiagnosis in qualifying animals for international movement and disease eradication programs than the CF systems currently in use. Use of the cELISA method also obviated the problems associated with testing hemolyzed or anticomplementary sera.

Animals↗
PubMed2000

A new conceptual model of asymmetry in motor performance for bidimensional fast-oscillating movements in selected variants of performance.

Spatial characteristics and lateral differences between two upper extremities were investigated in unilateral graphical tasks involving fast oscillating movements in the vertical plane based on the model of restricted (less than 10 degrees) horizontal abduction adduction in the shoulder joint. The spatial locations of reversal points were used to identify two groups of motor performance: with big angles and gross vertical vectors (stretched accordion group), and small projectile angles with small vertical vectors (compressed accordion group). Both groups appeared in right and left arm performance. The former group had a strong pattern of distribution of big and small projectile angles which reflects a particular variant of execution with a significant difference between angles and intermittent big and small angles (BB). Two other variants of execution relating to specific angular patterns of performance were identified in the compressed accordion group: one (Bs) showed a big difference between big and small angles but without intermittance; the other (ss) had only small differences between magnitudes of angles. The Bs variant of execution was observed only in left-handed performance, whilst ss was typical of both extremities. The performances affiliated to the stretched accordion group with the BB variant of execution mostly operated with reciprocal cooperation between alterations of X and Y vectors for the right arm. Performance related to the same group with the Bs variant of execution used concurrent collaboration involving alteration of these vectors for the left arm. The compressed accordion group which deployed the ss variant of execution mostly displayed concurrent alteration of vectors irrespective of the side of performance. It is suggested that the spatial movement strategies might reflect several different schemes of motor control wherein coupling of oscillators controls vertical and horizontal movements. It is also proposed that specific subunits of the functional system of nervous elements responsible for the expression of spatial derivatives of motor programmes may exist at lower levels of the CNS and might be initiated by the left brain or by the cooperative activity of the left and right hemispheres.

Adult↗
PubMed1999

A complex containing betaTrCP recruits Cdc34 to catalyse ubiquitination of IkappaBalpha.

Activation of transcription factor NF-kappaB is accomplished by degradation of its inhibitor IkappaBalpha. Signal induced phosphorylation of IkappaBalpha on serine 32 and 36 targets the protein for ubiquitination on lysine 21 and 22. Here we use a phosphorylated peptide substrate representing residues 20-43 of IkappaBalpha to investigate requirements for ubiquitination of IkappaBalpha. Phosphorylation dependent polyubiquitination is carried out by a multiprotein complex containing betaTrCP, Skp1 and Cdc53 (Cull). In the presence of ubiquitin activating enzyme and the protein complex containing betaTrCP, polyubiquitination of IkappaBalpha peptide was dependent on the presence of Cdc34, while Ubc5 only stimulated mono- and di-ubiquitination.

Amino Acid Sequence↗
PubMed1999

Gain of chromosome arm 17q and adverse outcome in patients with neuroblastoma.

BACKGROUND: Gain of genetic material from chromosome arm 17q (gain of segment 17q21-qter) is the most frequent cytogenetic abnormality of neuroblastoma cells. This gain has been associated with advanced disease, patients who are > or =1 year old, deletion of chromosome arm 1p, and amplification of the N-myc oncogene, all of which predict an adverse outcome. We investigated these associations and evaluated the prognostic importance of the status of chromosome 17. METHODS: We compiled molecular cytogenetic analyses of chromosome 17 in primary neuroblastomas in 313 patients at six European centers. Clinical and survival information were collected, along with data on 1p, N-myc, and ploidy. RESULTS: Unbalanced gain of segment 17q21-qter was found in 53.7 percent of the tumors, whereas the chromosome was normal in 46.3 percent. The gain of 17q was characteristic of advanced tumors and of tumors in children > or =1 year of age and was strongly associated with the deletion of 1p and amplification of N-myc. No tumor showed amplification of N-myc in the absence of either deletion of 1p or gain of 17q. Gain of 17q was a significant predictive factor for adverse outcome in univariate analysis. Among the patients with this abnormality, overall survival at five years was 30.6 percent (95 percent confidence interval, 21 to 40 percent), as compared with 86.0 percent (95 percent confidence interval, 78 to 91 percent) among those with normal 17q status. in multivariate analysis, gain of 17q was the most powerful prognostic factor, followed by the presence of stage 4 disease and deletion of 1p (hazard ratios, 3.4, 2.3, and 1.9, respectively). CONCLUSIONS: Gain of chromosome segment 17q21-qter is an important prognostic factor in children with neuroblastoma.

Analysis of Variance↗
PubMed1999

Fathers with severe mental illness: characteristics and comparisons.

Among patients with severe mental illness attending a large, urban, outpatient mental health clinic, fathers are described and compared with nonfathers and with mothers on demographic, clinical, and child-related characteristics, and on resources and service needs. While fathers and nonfathers with mental illness differed significantly on most variables, fathers and mothers with mental illness were remarkably similar except on child-related characteristics. Issues regarding fathers' experiences and service needs are discussed.

Adult↗
PubMed1999

A comparison of the shear bond strength of composite resin bonded by a fourth and a fifth generation dental adhesive to bovine teeth.

AIM: This study compared the shear bond strengths, to bovine enamel and dentine, of composite resin bonded using an established bonding agent (Syntac) and the more recent Syntac SC. METHOD: A total of 24 adult bovine incisors were divided into two equal groups and prepared by roughening the enamel surfaces with a medium-grit, high-speed diamond. The enamel was etched and 24 x 5 mm diameter composite discs were light-cured and bonded using Syntac and 24 using Syntac SC, following the manufacturer's instructions. The samples were shear tested 72 hours later at a crosshead speed of 50 mm/min using a Howden Universal Testing Machine. The labial enamel and 1 mm of dentine were removed and the experiment was repeated. RESULTS: The mean shear bond strengths (MPa) for the Syntac and Syntac SC bonded composite to enamel were 10.9 +/- 4.5 and 8.9 +/- 5.7, and to dentine 6.4 +/- 3.2 and 5.5 +/- 3.1, respectively. The differences between the values for each material on enamel and between each material on dentine were not significant (P > 0.01). However, nine (19%) Syntac SC bonded composite discs debonded during build-up and had to be remade, prior to testing. CONCLUSION: When a bond between composite and resin was achieved, no significant difference was found between the mean shear bond strengths of Syntac and Syntac SC bonded composite to either enamel or dentine. However, lack of composite adherence to the Syntac SC was noted during the preparation of specimens.

Animals↗
PubMed1998

Privatized Medicaid managed care in Massachusetts: disposition in child and adolescent mental health emergencies.

Data from child and adolescent emergency mental health screening episodes prior and subsequent to privatized Medicaid managed care in Massachusetts are used to investigate the relationship between payer source and disposition and to compare the match between clinical need and disposition level of care. Having Medicaid as the payer in the post-Medicaid managed care period decreased the odds of hospitalization by nearly 60%. None of the clinical need variables that contributed to hospitalization for Medicaid episodes in the pre-Medicaid managed care period were significant in the post-Medicaid managed care period. Multiple forces shaping professional standards, decision making, and quality of care are described. Public sector agencies must lay the groundwork for comprehensive evaluation prior to the implementation of privatized Medicaid managed care initiatives.

Adolescent↗
PubMed1998

European Y-chromosomal lineages in Polynesians: a contrast to the population structure revealed by mtDNA.

We have used Y-chromosomal polymorphisms to trace paternal lineages in Polynesians by use of samples previously typed for mtDNA variants. A genealogical approach utilizing hierarchical analysis of eight rare-event biallelic polymorphisms, seven microsatellite loci, and internal structural analysis of the hypervariable minisatellite, MSY1, has been used to define three major paternal-lineage clusters in Polynesians. Two of these clusters, both defined by novel MSY1 modular structures and representing 55% of the Polynesians studied, are also found in coastal Papua New Guinea. Reduced Polynesian diversity, relative to that in Melanesians, is illustrated by the presence of several examples of identical MSY1 codes and microsatellite haplotypes within these lineage clusters in Polynesians. The complete lack of Y chromosomes having the M4 base substitution in Polynesians, despite their prevalence (64%) in Melanesians, may also be a result of the multiple bottleneck events during the colonization of this region of the world. The origin of the M4 mutation has been dated by use of two independent methods based on microsatellite-haplotype and minisatellite-code diversity. Because of the wide confidence limits on the mutation rates of these loci, the M4 mutation cannot be conclusively dated relative to the colonization of Polynesia, 3,000 years ago. The other major lineage cluster found in Polynesians, defined by a base substitution at the 92R7 locus, represents 27% of the Polynesians studied and, most probably, originates in Europe. This is the first Y-chromosomal evidence of major European admixture with indigenous Polynesian populations and contrasts sharply with the picture given by mtDNA evidence.

Alleles↗