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J Haines

Publications and source records attributed to J Haines.

At least 19 recordsLinked to original sources
PubMed2001

Crystalline post-quartz phase in silica at high pressure.

alpha-quartz, which has been reported to undergo pressure-induced amorphization, was found to transform to a monoclinic, crystalline phase when compressed to 45 GPa at room temperature in a close to hydrostatic, helium pressure medium. The x-ray powder diffraction data obtained could be indexed based on a monoclinic cell, and the intensities are in agreement with a P2(1)/c model structure built up of 3x2 zigzag chains of SiO6 octahedra. This new polymorph of silica, which is metastable under ambient conditions, has been isolated for the first time and is one of several possible competing dense forms containing octahedrally coordinated silicon.

Journal Article↗
PubMed2001

Incorporating language phenotypes strengthens evidence of linkage to autism.

We investigated the effect of incorporating information about proband and parental structural language phenotypes into linkage analyses in the two regions for which we found the highest signals in our first-stage affected sibling pair genome screen: chromosomes 13q and 7q. We were particularly interested in following up on our chromosome 7q finding in light of two prior reports of linkage of this region to developmental language disorder, since one of the diagnostic criteria for autism is absent or abnormal language development. We hypothesized that if the language phenotype were genetically relevant to linkage at the chromosome 7q locus, then incorporating parents phenotypes would increase the signal at that locus, and most of the signal would originate from the subset of families in which both probands had severe language delay. The results support these hypotheses. The linkage signals we obtained on chromosome 7q as well as at least one signal on chromosome 13q are mainly attributable to the subgroup of families in which both probands had language delay. This became apparent only when the parents' history of language-related difficulties was also incorporated into the analyses. Although based on our data, we were not able to distinguish between epistasis or heterogeneity models, we tentatively concluded that there may be more than one autism susceptibility locus related to language development.

Autistic Disorder↗
PubMed2001

Analysis of loss of heterozygosity in lymphoma and leukaemia arising in F1 hybrid mice locates a common region of chromosome 4 loss.

Previous studies have identified five lymphoma-related tumour suppressor gene regions on murine chromosome 4. Using detailed allelotype analysis on a range of lympho-haematopoietic tumour types arising in F1 hybrid mice, we now show a consistent pattern of loss of heterozygosity (LOH) which identifies a common region of loss delineated by microsatellites D4Mit21 and D4Mit53 on proximal chromosome 4. This critical segment corresponds to the thymic lymphoma tumour suppressor region 5 (TLSR5) identified in an earlier study. Tumours of this type have also been reported as showing allelic loss from the Trp53 and Ikaros regions on chromosome 11. In the present study, only a small fraction of tumours showed LOH in the Ikaros region, while a minority of lymphomas, but not acute myeloid leukaemias, showed allelic loss of the chromosome 11 segment encoding Trp53. These and other data indicate strongly that the genomic regions identified as showing recurrent LOH depend on the genetic background of the mice. Overall, the results indicate a key role for a tumour suppressor gene(s) encoded in an approximately 3 cM segment on proximal chromosome 4 and provide an experimental basis for the further investigation of the functional role of candidate genes which include Pax5 and Tgfbr1.

Animals↗
PubMed2001

Evaluation of a mentorship program for heart transplant patients.

The Heart Transplant Mentor Programme (HTMP) was initiated to augment patient care by providing patients and families with information and support from a peer perspective. We assessed program effectiveness with a pilot study of semi-structured interviews of 63% (10/16) of the mentored patients and an open-ended inquiry that rated the program on a 5-point scale (1, poor, to 5, excellent) and that selected descriptors of the program. Qualitative and quantitative analyses indicated that participants found the information and support provided by their mentors positive (3.8 and 4.0, respectively), discussion focused on medical rather than psychosocial topics, pre-transplant dissatisfaction with the program was caused by late or little mentor contact, and post-transplant dissatisfaction was attributed to difference in clinical course between mentor and patient. Although findings indicate that HTMP augments patient care, recommendations to increase patient satisfaction include earlier introduction of a mentor and individualizing mentors according to demographics and clinical course.

Aged↗
PubMed2001

Food analyses using molecularly imprinted polymers.

Molecular imprinting technology (MIT) is a technique for generating polymers bearing biomimetic receptors. It offers several advantages to the agrofood industry in areas such as analysis, sensoring, extraction, or preconcentration of components. It has the potential of becoming a tool for acquiring truly simple, rapid, and robust direct measurements. In this review, the special features of MIT that have bearing on food science and technology are highlighted.

Chromatography↗
PubMed2000

Genetic mapping of a mouse modifier gene that can prevent ALS onset.

Mutations in the cytoplasmic Cu/Zn superoxide dismutase (SOD1) gene on human chromosome 21q22.1 cause 10-20% of familial amyotrophic lateral sclerosis (ALS) cases. The expression of the ALS phenotype in mice carrying the murine G86R SOD1 mutation is highly dependent upon the mouse genetic background. This is similar to the phenotypic variation observed in ALS patients containing identical SOD1 mutations. In the FVB/N background, mice expressing mG86R SOD1 develop an ALS phenotype at approximately 100 days. However, when these mice were bred into a mixed background of C57Bl6/129Sv, the onset of the ALS phenotype was delayed (143 days to >2 years). Using 129 polymorphic autosomal markers in a whole genome scan, we have identified a major genetic modifier locus with a maximum lod score of 5.07 on mouse chromosome 13 between D13mit36 and D13mit76. This 5- to 8-cM interval contains the spinal muscular atrophy (SMA)-associated gene Smn (survival motor neuron) and seven copies of Naip (neuronal apoptosis inhibitory protein), suggesting a potential link between SMA and ALS.

Amyotrophic Lateral Sclerosis↗
PubMed2000

Synthesis and crystal structure determination of a new pressure-induced iridium ditelluride phase, m-IrTe2, and comparison of the crystal structures and relative stabilities of various IrTe2 polymorphs.

The new monoclinic IrTe2 phase m-IrTe2 was synthesized under pressure, and its structure was determined by X-ray powder diffraction. The relative stabilities of the three known and three hypothetical IrTe2 polymorphs were discussed on the basis of tight binding electronic band structure calculations. m-IrTe2 exhibits structural features of both CdI2- and pyrite-type IrTe2 phases and is expected to be nearly as stable as that of the CdI2-type IrTe2. The hypothetical IrS2- and ramsdellite-type IrTe2 phases are predicted to be more stable than the CdI2-type IrTe2.

Journal Article↗
PubMed2000

Loss of heterozygosity in spontaneous and X-ray-induced intestinal tumors arising in F1 hybrid min mice: evidence for sequential loss of APC(+) and Dpc4 in tumor development.

Min (multiple intestinal neoplasia) mice carry a mutant allele of the murine Apc (adenomatous polyposis coli) locus and are predisposed to intestinal adenoma formation in the intestinal tract. Early studies have shown complete loss of function of Apc by whole chromosome loss on the tumor-sensitive C57BL/6J genetic background and in AKR x B6 F1 hybrids. Gamma-radiation-induced chromosomal losses focus the critical region on wt Apc, but because of the limited number of polymorphic markers used, no other critical regions of loss on chromosome 18 were identified. Using intestinal tumors arising spontaneously and induced by X-rays in CBA/H x C57BL/6J F1 hybrid mice and high-resolution microsatellite loss of heterozygosity (LOH) techniques, we provide mapping data for wt Apc loss, which confirms and extends earlier observations. In addition, high-frequency loss events at the Dpc4 locus were found in both spontaneous and radiation-induced tumors. These data identified LOH of Dpc4 as a critical secondary event following complete functional loss of Apc. LOH across the Trp53 genomic region of chromosome 11 was not observed. No LOH was recorded for the Mom1 candidate gene Pla2g2a or for 9 out of 10 polymorphic markers from the Mom1 genomic region on murine chromosome 4. One marker mapping distal to Pla2g2a showed LOH in a small minority of spontaneous tumors. These data support the contention that Mom1 does not act as a classical tumor suppressor. Overall, our data indicates a significant role for Dpc4 mutation in intestinal tumor progression in the mouse and provides further evidence for the importance of interstitial chromosome losses in radiation tumorigenesis.

Animals↗
PubMed2000

Revisiting HIV/AIDS.

Explore the source record for details and available documents.

Acquired Immunodeficiency Syndrome↗
PubMed1999

Crystal structure of moganite-type phosphorus oxynitride: relationship to other twinned-quartz-based structures.

The structure of moganite-type phosphorus oxynitride quenched from high-pressure high-temperature conditions has been refined using neutron powder diffraction data. This moganite-type structure, space group I2/a, Z = 12, is slightly less distorted with respect to the Imab aristotype than is moganite (a monoclinic form of silica). A close topological relationship has been identified between the moganite-type and orthorhombic BeH(2) structures indicating that SiO(2), PON and BeH(2) all adopt structures belonging to the twinned-quartz-based group. This group represents another possible structure type for systems composed of corner-sharing AX(4) tetrahedra. Structures of this group are obvious candidates for intermediate phases between the cristobalite and quartz types.

Journal Article↗
PubMed1999

The self-mutilative nature of severe onychophagia: a comparison with self-cutting.

OBJECTIVE: To investigate the psychophysiological pattern associated with severe and mild onychophagia, and to compare this pattern with that demonstrated by previous research on self-cutting. METHOD: Comparisons between the psychophysiological responses accompanying 3 behaviours were made using a guided imagery methodology. Imagery of nail-related, skin-cutting, and neutral events were presented in 4 stages. RESULTS: Experiment I distinguished participants exhibiting severe and mild onychophagia by the severity and frequency of nail-biting and by the pattern of psychophysiological response across the stages. Experiment II indicated that the change in psychophysiological arousal accompanying severe onychophagia was not as dramatic as that demonstrated for skin-cutting. The behaviour seems to be less effective in reducing tension. CONCLUSION: Severe onychophagia appears to manage the level of tension experienced by an individual, instead of dramatically reducing it in times of crisis. Such a process is consistent with that demonstrated in individuals with obsessive-compulsive disorder.

Adult↗