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Biomedical subjects

B Davies

Publications and source records attributed to B Davies.

At least 19 recordsLinked to original sources
PubMed1992

Chemiluminescence of human bloodstream monocytes and neutrophils: an unusual oxidant(s) generated by monocytes during the respiratory burst.

Maximal rates of O2- and H2O2 production by human bloodstream monocytes activated during the respiratory burst by phorbol ester were only about 10% of those of neutrophils. Furthermore, monocytes possess only about 5% of the myeloperoxidase activity of neutrophils and so can only produce low levels of HOCl and related compounds. These combined reductions in O2- generating ability and lower myeloperoxidase levels result in low levels of luminol chemiluminescence stimulated during the respiratory burst of monocytes. However, although monocytes generate much lower levels of O2- and H2O2 than neutrophils, these cells produce comparable rates of PMA-stimulated lucigenin chemiluminescence. Hence, this assay does not accurately reflect the production of either of these two oxidants by activated phagocytes, and further lucigenin must react with some other oxidant(s) via a process which leads to photon emission. This oxidant(s) is not O2-, H2O2, .OH, 1O2 or NO, but is derived from O2- generated during the respiratory burst and is generated in greater quantities by activated monocytes compared with neutrophils. Thus, lucigenin chemiluminescence is an indirect measure of superoxide release.

Acridines↗
PubMed1992

The mapping of seven intron-containing ribosomal protein genes shows they are unlinked in the human genome.

Mammalian ribosomal protein (rp) genes are members of multigene families which are composed predominantly of multiple processed pseudogenes and one functional intron-containing gene. The presence of multiple pseudogenes has hampered the isolation and study of the functional rp genes. We have recently developed a polymerase chain reaction (PCR)-based strategy for the detection of intron-containing genes in the presence of multiple pseudogenes (B. Davies, S. Feo, E. Heard, and M. Fried, 1989, Proc. Natl. Acad. Sci. USA 86: 6691-6695). We have used this technique to identify the intron-containing PCR products of seven human rp genes (rpL19, rpL30, rpL35a, rpL36a, rpS6, rpS11, rpS17) and to map their chromosomal locations. No linkage was found between any of these seven rp genes nor was linkage found to the three other rp genes previously mapped. The wide distribution of the rp genes throughout the human genome strongly suggests that the coordinate regulation of the expression of mammalian ribosomal proteins in response to the cell's varying requirements for protein synthesis is not a result of cis activation of chromosomal regions but is mediated by trans-acting factors.

Blotting, Southern↗
PubMed1992

Interactions between human monocytes and tumour cells. Monocytes can either enhance or inhibit the growth and survival of K562 cells.

Human bloodstream monocytes can kill cultured tumour cells (K562), as assessed by specific release of 51Cr from the targets and by inhibition of 3H-thymidine incorporation. Confluent monolayers of monocytes were required for maximal cytotoxicity, and the density of the K562 cells was also an important factor. For example, when K562 cells were seeded at high cell densities, they were killed during incubation with monocytes, but when seeded at low cell densities their growth and survival was enhanced during culture with monocytes. The factor(s) which promoted the survival and division of low density K562 cultures was endogenously secreted from monocytes as it was present in monocyte-conditioned medium, whereas the cytotoxic factor(s) were only expressed during co-culture of monocytes with K562 cells. Conditioned medium from HL 60, U-937, HeLa and K562 could also enhance the growth and survival of low density K562 cultures, and a similar effect was also observed upon the addition of catalase and superoxide dismutase to such cultures. Thus, the monocyte:target ratio is important in determining whether monocytes exhibit cytotoxic or growth-promoting effects and hence tumour-derived or monocyte-derived reactive oxidant species may play a role in tumour cell cycle regulation.

Catalase↗
PubMed1992

Do patients like day case cataract surgery?

One hundred and fifty consecutive questionnaires following day case cataract surgery showed that 87% of the patients would choose day surgery again. The questionnaires were directed at the patients' attitudes to day surgery for their cataracts. There was overwhelming acceptance of the travelling and inconvenience involved.

Aged↗
PubMed1992

Electrosurgery in restorative dentistry: 1. Theory.

Electrosurgery techniques have been used in dentistry as an aid to soft tissue management for nearly 60 years. However, it was not until the late 1960s that the principles of electrosurgery were understood and improved equipment became available. Part 1 of this two-part series covers the theory behind using this technique. Part 2 will discuss the clinical applications.

Dentistry, Operative↗
PubMed1992

Electrosurgery in restorative Dentistry: 2. Clinical applications.

Electrosurgery techniques have been used in dentistry as an aid to soft tissue management for nearly 60 years. However, it was not until the late 1960s that the principles of electrosurgery were understood and improved equipment became available. Part 1 of the two-part series covered the theory behind using this technique. Part 2 will now discusses the clinical applications.

Dental Restoration, Permanent↗
PubMed1992

Do children with developmental delays use more frequent and diverse language in verbal routines?

The current study is the first to test the hypotheses that children with developmental delays use more frequent language and more diverse vocabulary in routines than in nonroutines. The 19 child participants were in Brown's (1973) first stage of language learning. Using a novel method of measuring routines, 18 of the parents identified at least one routine in a videotaped play session with their children. Results support both hypotheses and provide descriptive information about the content of the routines displayed by the parents and children in the free-play context. The importance of replicating the findings in the context of an experimental design before concluding that "routineness" caused the children to talk more often and with more diverse vocabulary was emphasized.

Child↗
PubMed1992

Support and caring: exploring the concepts.

In their article "Dimensions of the Supportive Role of the Nurse in Palliative Care" (ONF 17:87-94, 1990), the authors used a grounded-theory approach based on the actual experiences of an expert nurse in supportive care. In this article, the authors relate their concepts of support to existing nursing theory and to previous clinical research in both support and caring. Justification for the dimensions of the model was found in the nursing literature. However, distinguishing support and caring as concepts was difficult.

Attitude of Health Personnel↗
PubMed1991

Eating disorders in young adults with insulin dependent diabetes mellitus: a controlled study.

OBJECTIVE: To determine the prevalence of clinical eating disorders and lesser degrees of disturbed eating in young adults with insulin dependent diabetes and a matched sample of non-diabetic female controls. DESIGN: Cross sectional survey of eating habits and attitudes in diabetic and non-diabetic subjects. SETTING: Outpatient clinic catering for young adults with diabetes; community sample of non-diabetic women drawn from the lists of two general practices. SUBJECTS: 100 patients with insulin dependent diabetes (54 women and 46 men) aged 17-25 and 67 non-diabetic women of the same age. MAIN OUTCOME MEASURES: Eating habits and eating disorder psychopathology were assessed by standardised research interview adapted for the assessment of patients with diabetes (eating disorder examination). Glycaemic control was assessed by glycated haemoglobin assay. RESULTS: In both non-diabetic and diabetic women disturbed eating was common, and in diabetic women the degree of disturbance was related to control of glycaemia. Twenty of the diabetic women (37%) had omitted or underused insulin to influence their weight. This behaviour was not restricted to those with a clinical eating disorder. None of the men showed any features of eating disorders, and none had misused insulin to influence their weight. CONCLUSIONS: There was no evidence that clinical eating disorders are more prevalent in young women with diabetes than in non-diabetic women. Nevertheless, disturbed eating is common and is associated with poor control of glycaemia, and the misuse of insulin to influence body weight is also common in young women with diabetes.

Adolescent↗
PubMed1991

Psychiatric morbidity in young adults with insulin-dependent diabetes mellitus.

Psychiatric disorder and sub-threshold psychological distress were more common in 113 young men and women with insulin-dependent diabetes living in a defined area than in comparable general population samples. Twelve per cent of men and 19% of women were classified by the PSE as psychiatric 'cases'. Forty per cent of women and 47% of men reported at least one major social problem; effects of diabetes on everyday activities were common. There were associations between medical and social variables. The clinical implications are discussed.

Adolescent↗
PubMed1991

The role of lidocaine, epinephrine, and flap elevation in wound healing after chemical peel.

We have observed 5 patients with hypertrophic scarring at the lateral boundaries of the chemically peeled area when circumoral peel was combined with facial rhytidectomy. Some of the potential contributory factors include flap elevation, epinephrine, and lidocaine hydrochloride. To discover whether any one of these three factors or a combination played a role, a rat model study was designed. Initially, 40, 400-gm Sprague-Dawley rats were divided into 4 groups, each comprised by 10 rats. Injections with lidocaine or lidocaine with epinephrine, and chemical peel were done in 2 groups. The same injections were used in the remaining 2 groups together with simultaneous preliminary flap elevations and chemical peeling. After the review of the initial study results, another 40 Sprague-Dawley rats were used to repeat the study and compare on a larger scale the effects of lidocaine with and without epinephrine on the depth of chemical peel. The findings of the rat model studies indicate that preliminary injections with lidocaine containing solution (with or without epinephrine) result in a major delay in healing time. Flap elevation and chemical peeling were associated with major morbidity and mortality in the test rats. The presence of epinephrine in lidocaine solution had no significant role in increasing the delay in the healing process.

Animals↗
PubMed1991

Palliative care. The nurse's role in helping families through the transition of "fading away".

Oncology nurses are finding themselves increasingly involved in providing palliative care. A foundational tenet of palliative care is that the entire family, not just the patient, is the unit of care. Although nursing literature on care of the family is growing, nursing approaches tend to be described in general terms. A recent study of families caring for a member with advanced cancer generated a theoretic scheme which indicated that the families' experience could be conceptualized as a transition: the transition of fading away. This theoretic scheme served as the foundation for identifying nursing approaches which could be helpful to families engaged in the transition. This paper expands on the nursing approaches so that nurses may be better prepared to help families through the transition of fading away.

Adaptation, Psychological↗
PubMed1991

Identifying the referents of spoken messages: use of context and clarification requests by children with and without mental retardation.

The ability of children with mental retardation and of children without mental retardation matched to them on nonverbal MA to use (a) contextual information and (b) clarification requests to resolve referential ambiguity was evaluated. Each child pretended to be a storekeeper and responded to an adult customer's ambiguous requests. The context disambiguated the request in some cases, but not in others. Both groups of children selected the appropriate referent when the context was informative. Only the children without mental retardation appropriately requested clarification when the context was uninformative. Referential performance was not related to their receptive language level or nonverbal MAs.

Child↗
PubMed1990

Do parental questions and topic continuations elicit replies from developmentally delayed children? A sequential analysis.

This sequential analysis tested the relative extent to which several adult utterance types elicited conversational replies from developmentally delayed children. Eight developmentally delayed children in Brown's stages I and II and their primary parents were the subjects. Parent-child pairs were video and audio taped during their interactions with experimenter-provided toys in a lab setting. Transcripts of the interactions were coded for adult topic relatedness and obligation level and for child topic relatedness, length, and intelligibility. The results indicated that child replies of any length were elicited by adult topic continuations more than by any other adult utterance type. If a new topic was initiated, explicit prompts for child talk elicited child replies more than other adult utterance types. Multiword child replies were most likely to be elicited by explicit prompts that continued the child's topic. Child effects on the presence and effectiveness of adult conversational recruiting strategies were also tested.

Child↗