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Biomedical subjects

P Pearson

Publications and source records attributed to P Pearson.

At least 55 records · Page 3Linked to original sources
PubMed1991

Human development and umami taste.

Previously we demonstrated that in very brief, one-bottle intake tests, human infants, both well nourished and protein calorie malnourished, ingested greater amounts of soup with added MSG compared with soup alone. The potentiating effect of MSG in plain aqueous solution was tested in the current experiments. In contrast to data with sucrose and salt solution, where infants preferentially ingest these compounds compared with a water diluent, aqueous MSG solutions were rejected relative to water. The implications of this observation for understanding the mechanisms of MSG perception and pleasantness were discussed.

Child Development↗
PubMed1991

Clients' perceptions: the use of case studies in developing theory.

This paper describes some aspects of a study which looked at clients' perceptions of health visiting, and how, if at all, these related to their perceptions of health needs. The researcher explored the alterations of these perceptions over time, and also examined how they related to professional perceptions. The background to this study is described. The methods used are outlined. The study was carried out in two phases. The first phase used semistructured interviews and diaries to explore 41 parents' perceptions at one point in time. In phase two, a series of three semistructured interviews were completed over a 10-month period with 19 primiparous parents, commencing antenatally, and with 10 of their health visitors. Analysis was by the grounded theory method. The eight concept areas which emerged from the data are listed. The paper goes on to discuss the use of case studies in developing a substantive theory. Finally, some of the implications which this study has for health visiting practice are outlined.

Community Health Nursing↗
PubMed1990

Colposcopic diagnosis and treatment of cervical dysplasia at a single clinic visit. Experience of low-voltage diathermy loop in 1000 patients.

In a study of 1000 women referred over 20 months with abnormal smears and in whom the entire transformation zone could be seen the aim was to test the feasibility of colposcopic assessment and treatment at one visit to the clinic. 897 women needed only one visit. This was achieved by using a modification of the large loop diathermy excision technique and by careful attention to the timing of the clinic visit. 103 required further visits, for the following reasons: incomplete excision on histology and/or subsequently abnormal smear (85), secondary haemorrhage (6), microinvasion or invasive carcinoma (9), biopsy specimens unusable (3). Further treatment was given in 4.1% of the cervical dysplasias. All patients treated in a single visit preferred this approach to the alternative of colposcopic assessment and biopsy followed, after histological examination, by local ablation by laser, excision by loop biopsy technique, or cone biopsy.

Biopsy↗
PubMed1990

Screening elderly people in primary care: a randomized controlled trial.

A randomized controlled trial was carried out to test the effectiveness of a screening programme carried out by nurses for elderly people aged 75 years and over in a general practice. A total of 151 people were randomly allocated to the test group and 145 to the control group. The test group received a home visit from a nurse at which an assessment lasting 45 minutes was made of: activities of daily living, social functioning, sensory functions, mental and emotional problems, current medical problems, blood pressure, urinalysis, haemoglobin level and compliance with medication. Both groups completed a selection of items from four health indices before and 20 months after the intervention. At follow up, the test group scored significantly better than the control group on a morale scale. However, this trial provided no evidence for better resolution of physical problems or finding activities of daily living easier in the test group compared with the control group. It is suggested that the main benefit of such a screening process is that the special attention and education provided improves adaptation to old age and awareness of the support systems available. The government has proposed an annual review of elderly people in their own home and this study suggests that the objectives of this scheme should be clarified.

Aged↗
PubMed1986

Deletion on the X chromosome detected by direct DNA analysis in one of two unrelated boys with glycerol kinase deficiency, adrenal hypoplasia, and Duchenne muscular dystrophy.

In studies of the X chromosomes of two unrelated boys with adrenal hypoplasia, glycerol kinase deficiency, Duchenne muscular dystrophy, and mental retardation, conventional G banding did not reveal any numerical or structural abnormality, but direct DNA analysis with the X short-arm probes 754, C7, and OCT revealed a deletion in 1 of these patients. It is likely that both boys have a deletion at Xp21 affecting a number of closely linked disease-specific gene loci.

Adrenal Insufficiency↗
PubMed1986

Construction and analysis of an EMBL-3 phage library containing partially digested human chromosome 21-specific DNA inserts (15-20 kb).

In the mouse-human hybrid cell line SCC 16-5, chromosome 21 is the only human chromosome present. Fractions highly enriched for this chromosome were obtained by applying the chromosome velocity sedimentation technique to this cell line. DNA prepared from these chromosomal fractions was partially digested with Mbo I, size fractionated on an NaCl gradient, and cloned in the EMBL-3 phage vector. The phage library thus prepared was highly enriched for human chromosome 21-specific recombinant DNA sequences 15-20 kb long. Of the approximately 21,000 phage clones obtained, at least 99% were recombinant. Following phage plaque filter hybridization and Southern blotting, it was found that half of the recombinants were positive for human repetitive DNA. Almost all phages harbored highly or middle repetitive human or mouse DNA sequences owing to the large size of the recombinant inserts. In this library, the human chromosome 21 is represented approximately four times. All human recombinants studied thus far contained DNA inserts originating from chromosome 21 only. The employed cloning strategy is discussed with regard to utility, purity, quality, and completeness of chromosome-specific recombinant DNA libraries.

Animals↗
PubMed1986

Detection of chromosome aberrations in the human interphase nucleus by visualization of specific target DNAs with radioactive and non-radioactive in situ hybridization techniques: diagnosis of trisomy 18 with probe L1.84.

The localization of chromosome 18 in human interphase nuclei is demonstrated by use of radioactive and non-radioactive in situ hybridization techniques with a DNA clone designated L1.84. This clone represents a distinct subpopulation of the repetitive human alphoid DNA family, located in the centric region of chromosome 18. Under stringent hybridization conditions hybridization of L1.84 is restricted to chromosome 18 and reflects the number of these chromosomes present in the nuclei, namely, two in normal diploid human cells and three in nuclei from cells with trisomy 18. Under conditions of low stringency, cross-hybridization with other subpopulations of the alphoid DNA family occurs in the centromeric regions of the whole chromosome complement, and numerous hybridization sites are detected over interphase nuclei. Detection of chromosome-specific target DNAs by non-radioactive in situ hybridization with appropriate DNA probes cloned from individual chromosomal subregions presents a rapid means of identifying directly numerical or even structural chromosome aberrations in the interphase nucleus. Present limitations and future applications of interphase cytogenetics are discussed.

Cell Nucleus↗
PubMed1986

Very close linkage between D2S1 and ACP1 on chromosome 2p.

The genomic DNA-probe L2.30 was used to assign D2S1 to 2p23-pter by in situ hybridization. The RFLP revealed by BglII was then used for linkage studies in the Oslo-NHIK families segregating for the acid phosphatase ACP1 protein polymorphism. Evidence for very close linkage was found by a lod score of +17.17 at recombination fraction theta = 0.01. By this close linkage 92 informative meioses could be inferred from the families and with only a single crossover. The upper probability limit to the recombination fraction is 0.06 according to the HGM 8 criterion. No association between ACP1 alleles and D2S1 BglII alleles was found. The Norwegian gene frequencies for D2S1 were A1 (9.0 kb) = 0.65 and A2 (6.3 kb) = 0.35.

Acid Phosphatase↗
PubMed1985

Prenatal exclusion of ornithine transcarbamylase deficiency by direct gene analysis.

Direct gene analysis was used in the prenatal exclusion of ornithine transcarbamylase (OTC) deficiency; karyotyping the family's previously affected child had already identified the defect as a small deletion. A cloned OTC gene and two other X chromosome-specific probes were mixed, and hybridised to fetal DNA obtained from cultured amniocytes; the fetus was shown to be a normal male.

Adult↗
PubMed1985

Zygosity determination in newborn twins using DNA variants.

A prerequisite for the optimal use of the twin method in human genetics is an accurate determination of the zygosity at birth. This diagnosis is sometimes hampered by the lack of available specific markers. We report here the use of DNA variants (restriction fragment length polymorphisms) as genetic markers for zygosity determination. We have analysed the placental DNA of 22 twin pairs with known zygosity on Southern blots by hybridisation with polymorphic human DNA probes. We looked at six different polymorphic sites using four restriction enzymes and six DNA probes. Among 10 dizygotic (DZ) pairs, only one was not demonstrably different and seven had at least two discordances. Within each of the 12 monozygotic (MZ) pairs there was complete concordance. Thus, nine of 10 dizygotic and 12 of 12 monozygotic twins were assigned their correct zygosity solely by comparison of six DNA variants. The use of these highly polymorphic DNA probes may have practical importance for antenatal diagnosis and paternity testing.

DNA Restriction Enzymes↗
PubMed1985

Mapping DNA sequences in a human X-chromosome deletion which extends across the region of the Duchenne muscular dystrophy mutation.

A somatic cell hybrid has been constructed and characterized using fibroblasts from a phenotypically normal woman who possesses an X chromosome with an interstitial deletion of the short arm. High-resolution banding indicates that the deleted segment is either Xp22.13-p11.4 or Xp22.11-p11.23. Southern blot hybridization to previously mapped DNA sequences confirms that the missing segment of the X chromosome is a deletion and not an interstitial translocation and supports the cytogenetic interpretation that the deletion extends proximal of Xp11.3 and therefore probably comprises Xp22.11-p11.23. Three further DNA sequences have been localized to the region of the deleted segment. The following order has been assigned to the seven probes used: Xpter-RC8-pXUT22-(OA1,C7,M2C)-L1.28-RD6 -Xcen.

Animals↗