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Biomedical subjects

S Turner

Publications and source records attributed to S Turner.

At least 19 recordsLinked to original sources
PubMed1992

Resistance of primary isolates of human immunodeficiency virus type 1 to neutralization by soluble CD4 is not due to lower affinity with the viral envelope glycoprotein gp120.

Recombinant soluble CD4 (rsCD4) has potent antiviral activity against cell line-adapted isolates of the human immunodeficiency virus type 1 (HIV-1) but low activity toward HIV-1 primary isolates from patients. A simple hypothesis proposed to explain this discrepancy, which questions the therapeutic utility of soluble CD4-based approaches, is that the major envelope glycoprotein, gp120, of patient virus has lower affinity for CD4 than does gp120 from laboratory viruses. To test this hypothesis, we have produced pairs of low- and high-passage HIV-1 isolates which, depending on culture passage history, display dramatically different sensitivities to neutralization by rsCD4. Here, we present evidence that the HIV-1 major envelope glycoprotein cDNAs cloned from one such isolate pair show only minor differences in their deduced gp120 primary structures, and these occur outside regions previously shown to be involved in CD4 interactions. In addition, recombinant gp120 from a low-passage rsCD4-resistant patient virus binds rsCD4 with high affinity, equal to that previously measured for recombinant gp120 from high-passage cell line-adapted virus isolates. These data indicate that differences in CD4-gp120 affinity do not account for rsCD4 resistance in HIV-1 recently isolated from patients.

Amino Acid Sequence↗
PubMed1992

The use of the Ways of Coping (Revised) questionnaire with parents of children with Down's syndrome.

The principal aim of this study was to assess the validity and usefulness of the Ways of Coping (Revised) questionnaire (Folkman & Lazarus, 1985) with a British sample of parents of children with Down's syndrome. Factor analysis yielded five subscales which were compared with those reported elsewhere. Other properties of the instrument were investigated. It was concluded that the instrument was potentially valuable to those investigating coping in families with special problems.

Adaptation, Psychological↗
PubMed1992

Brief report: recent findings on the Sexual Aversion Scale.

This study provides additional information on the psychometric properties of the Sexual Aversion Scale (SAS). Results suggest a positive relationship between sexual aversion, generalized anxiety, and history of sexual victimization. Variables such as age and religiosity were unrelated to scores on the SAS, although females reported significantly more sexual anxiety than males. The factor structure of the SAS is described and suggests that sexual aversion is a multifaceted problem with at least three and possibly four different dimensions.

Adolescent↗
PubMed1992

Paediatricians' practice in disclosure and follow-up of severe physical disability in young children.

Twenty-four paediatricians were asked about their policy and practice regarding disclosure and follow-up of the diagnosis of disability, and for suggestions to improve current practice. Doctors with less clinical experience were more likely to mention the presence of the child as an element of the disclosure interview, and scored higher than those with more experience on an index score of the format of the disclosure interview. Paediatricians' reported constraints on their preferred practice and findings from interviews with mothers in the same study confirmed continuing shortcomings in disclosure practice. Changes in medical training, the adoption of a written policy of good practice and the nomination of a 'key worker' for each family are suggested.

Child↗
PubMed1992

Psychophysiological investigations of patients with unilateral symptoms in the hyperventilation syndrome.

Anxiety states sometimes lead to hyperventilation (HV) which may, in turn, give rise to a variety of physical symptoms. One way in which HV may present is with unilateral somatosensory symptoms, often left-sided. We report nine such cases. The mechanisms of lateralisation was examined using EEG and bilateral somatosensory evoked potentials which were carried out before and after HV. No difference in conduction velocity was found between affected and unaffected arms, but non-specific abnormalities were frequently noted in the EEGs. The results support the role of a central rather than a peripheral mechanism in the production of unilateral symptoms in HV.

Adult↗
PubMed1991

Production of multimeric forms of CD4 through a sugar-based cross-linking strategy.

We have developed a three-step cross-linking procedure that is specifically targeted at the carbohydrate on a protein and applied it to CD4 as a model system for studying the role of multivalent interactions in function. In the first step CD4 was oxidized with periodate, creating aldehydes that served as targets for the subsequent chemistry. Next the aldehydes were modified with cystamine, converting the reactive group into a thiol. Finally cross-linking through the thiol moiety was generated with the homobifunctional cross-linker bismaleimidohexane. With this procedure, approximately 60% of the CD4 was converted into higher molecular weight complexes that were soluble and retained function as assessed by glycoprotein gp120 binding activity. CD4 dimers and tetramers by mass were 4 and 15 times as active as CD4 monomer in blocking virus infection with HTLV-IIIB in an in vitro cellular assay. The cross-linking chemistry provides an efficient method for producing homomultimers of a glycoprotein.

Amino Acids↗
PubMed1991

Molecular evidence for the origin of plastids from a cyanobacterium-like ancestor.

The origin of plastids by either a single or multiple endosymbiotic event(s) and the nature of the progenitor(s) of plastids have been the subjects of much controversy. The sequence of the small subunit rRNA (Ssu rRNA) from the plastid of the chlorophyll c-containing alga Cryptomonas phi is presented, allowing for the first time a comparison of this molecule from all of the major land plant and algal lineages. Using a distance matrix method, the phylogenetic relationships among representatives of these lineages have been inferred and the results indicate a common origin of plastids from a cyanobacterium-like ancestor. Within the plastid line of descent, there is a deep dichotomy between the chlorophyte/land plant lineage and the rhodophyte/chromophyte lineage, with the cyanelle of Cyanophora paradoxa forming the deepest branch in the latter group. Interestingly, Euglena gracilis and its colorless relative Astasia longa are more related to the chromophytes than to the chlorophytes, raising once again the question of the origin of the euglenoid plastids.

Base Sequence↗
PubMed1991

The validity and applicability of the ADIECAS classroom rating scale in a sample of children with Down's syndrome.

The ADIECAS classroom behaviour rating scale (Evans & Hogg, 1984) was used with a sample of 123 children with Down's syndrome as part of a wider study of child and family adaptation. According to Evans & Hogg, the ADIECAS scale measures two types of behaviour: attentiveness-distractability, and inhibition-excitability. Such measures of behaviour style may be related to behaviour problems and child and family relationships for children with mental handicap. The factor structure of the 16 ADIECAS items was investigated by using confirmatory factor analysis within the LISREL program. Overall, the original factor structure was found to be a poor fit to the new data, in that, while the distractability factor replicated well, the excitability factor split into three. After examining the components of the four factors, two were discarded as containing unreliable items, and goodness of fit statistics on the two revised factors, using 10 of the original 16 items, gave the best results. Thus, the factors structure showed only limited replicability with a different subject group from the original Evans & Hogg study.

Arousal↗
PubMed1991

Factors relating to self-sufficiency in children with Down's syndrome.

An index of self-sufficiency in children with Down's syndrome was developed for use in a study of the process of adaptation in families living in the Greater Manchester area. The children were 6-14 years old, and living at home. Index scores were based on the mothers' responses to a questionnaire covering their children's personal and domestic functioning and community self-sufficiency, and were obtained from 111 of the 117 mothers who took part in the study. A wide range of child- and family-related variables were found to be significantly associated with self-sufficiency scores on a univariate level. Multiple regression analysis was used to identify those variables which best predicted the level of self-sufficiency achieved. After the child's mental age, the most significant variables were excitability, behaviour problems, the extent the mother used practical means of coping, and the level of social activity experienced by the child. Together, these five variables explained 63% of the variance in self-sufficiency scores. The dynamics by which such factors may relate to self-sufficiency in children with Down's syndrome are discussed, and intervention aimed at promoting the use of practical ways of coping by parents is suggested.

Activities of Daily Living↗
PubMed1991

Factors related to stress and satisfaction with life in families of children with Down's syndrome.

In a study of families of children with Down's syndrome, measures of parent, family and child characteristics were obtained from mothers and fathers. Multivariable analyses investigated their relationships to outcome measures of psychosomatic symptoms of stress and parents' perceived satisfaction with life. Personality factors were related to outcome for both parents. For mothers, the children's levels of behaviour problems, excitability and self-sufficiency were strongly related to outcome. Coping strategies, family relationships and socio-economic factors also showed significant effects. For fathers, child characteristics were not related to outcome. The marital relationship was an important factor and there was evidence that factors external to the family acted as stressors.

Adaptation, Psychological↗
PubMed1991

Is the appearance of children with Down syndrome associated with their development and social functioning?

The appearance of 111 children with Down syndrome, aged six to 14 years, was rated by their class teachers as part of a larger study on factors associated with their development, social life-style and family functioning. There were no significant associations between measures of child development, communicative or independent functioning, social life, behaviour problems or with parental stress, parent-child relationships or quality of family life. Typical features of Down syndrome are not major correlates of development and social functioning, and no support could be found to justify routine cosmetic surgery aimed at ameliorating such features.

Achievement↗
PubMed1979

Community residential treatment for skid row alcoholics.

A significant factor affecting the chance for recovery is the ability of the skid row alcoholic to form and sustain a relationship with someone or something. The author describes an open-ended, community residential program that encourages such relationships and which is proving to be an effective treatment model.

Alcoholics Anonymous↗
PubMed1978

Localisation of human speech by the newborn baby and the effects of pethidine ('meperidine').

Eight newborn babies were tested to see whether they could make discriminating headturn responses to the sound of a 9-second recording of a human voice coming from 15 degrees, 30 degrees and 80 degrees from the midline, from either the right or left side. The babies showed significant differences in response to sounds coming from the right and the left, and to sounds coming from 15 degrees and 80 degrees from the midline. Pethidine ('Meperidine') given to the mother during labour had a significant effect, both on degree of response and on the babies' apparent ability to localize sound.

Anesthesia, Obstetrical↗
PubMed1976

Effect of passage in culture on a clone of BALB/c 3T3 cells transformed by simian virus 40.

Most simian virus 40 (SV40)-transformed BALB/c 3T3 clones employed for biochemical studies have been used without regard to passage level. To determine whether virus-induced properties are stable as a function of passage, we have extensively characterized one transformed clone, FNE, which was isolated after SV40 infection BALB/c 3T3 cells in factor-free medium. From the initial testing at passage 5 and for at least 50 subsequent subcultures, the cells stably maintained many transformed growth properties, including high saturation density, morphology, colony formation on contact-inhibited monolayers, tumorigenicity, and synthesis of viral-specific RNA. However, other properties varied as a function of passage. There was a slight decrease in viral genome equivalents per cell from 1.1 copy/cell at passage 5 to 0.7 copies at passage 40. Initially, the cells were negative for all type C virus; however, cells carried at low density for 13 to 20 passages (65 to 100 generations) began to release an endogenous type C virus that then persisted in the culture. Spontaneous release of type C virus did not occur in control BALB/c 3T3 cells carried under identical culture conditions for 90 passages. When the cultures were releasing type C viruses they stained uniformly and brightly positive for SV40 tumor (T) antigen by immunofluorescence, whereas T antigen staining was variable at early passage. These experiments suggest that subtle but perhaps important differences in viral gene expression can occur as a function of passage; they also demonstrate the importance of evaluating the interactions between SV40 and endogenous type C viruses.

Animals↗
PubMed1976

The role of radiotherapy in the definitive management of rectal carcinoma.

The role of radiotherapy in the management of rectal and rectosigmoid cancer is still far from clear. Our experience with 98 patients is presented: eight patients were treated with radical radiotherapy, 13 received postoperative radiation, and 67 were treated for palliative purposes only (bleeding, pain, mass, and fistulation). Satisfactory results were demonstrated in all three categories, and sterilization of disease by radiation was histologically proven in three cases. The necessity of high-dose radiation for the achievement of optimum results is demonstrated, and the techniques and problems are described.

Adult↗