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Biomedical subjects

C Webb

Publications and source records attributed to C Webb.

At least 91 records · Page 5Linked to original sources
PubMed1992

Visually impaired patients' perceptions of their needs in hospital.

This article reports on a study of visually impaired patients' perceptions of their social and psychological needs in hospital. A qualitative approach was taken to explore and describe these perceptions, and 18 in-patients from one ophthalmic hospital took part in semi-structured interviews lasting approximately half an hour. Patients did not agree on their most important need. Many stresses and methods of coping were specific to individual patients. Patients reported on three areas in which most of them had problems: behavior of some staff, anxiety, and communication, but most felt their physical needs were met by nurses. Implications and recommendations for nursing practice are discussed. In particular, the results indicate a need for individualised care. It is also apparent that further research is needed to explore nurses' beliefs and feelings towards visual impairment.

Adaptation, Psychological↗
PubMed1991

Child sexual abuse prevention: evaluation and one-year follow-up.

Because of the high incidence and negative psychological consequences of child sexual abuse, prevention programs have been developed and implemented nationwide. Few programs, however, have been comprehensively evaluated. In this multimodal study, a 3-session adaptation of the Feeling Yes, Feeling No curriculum was provided to 286 third and fourth graders from four schools whose responses were compared to 113 delayed-treatment control children from two schools. Program impact was assessed using a knowledge scale, the State-Trait Anxiety Inventory for Children, a videotape vignettes measure, a parent questionnaire, and disclosure data. Treatment children exhibited significantly greater knowledge and better ability to discriminate safe from unsafe situations on the video measure than control children at posttesting. These gains were maintained at 6-week follow-up testing. There were no differences in treatment and control children's self-reported anxiety or parents' reports of negative emotional/behavioral consequences, which were minimal. Over 5% of participating children reported ongoing or past sexual abuse. In the One-Year Follow-Up Study, children's knowledge gains and prevention skills scores on the video measure were maintained at one-year follow-up. A 1-session "booster shot" program further enhanced children's safety discrimination skills on the video measure.

Adaptation, Psychological↗
PubMed1991

Activated neutrophils depress myocardial function in the perfused rabbit heart.

OBJECTIVE: To examine the effect of activated neutrophils on myocardial function in the absence of ischemic and/or reperfusion injury. DESIGN: Studies were carried out in five groups of Langendorff perfused rabbit hearts: control; nonactivated rabbit neutrophil infusion; phorbol myristate acetate-activated rabbit neutrophil infusion; nonactivated human neutrophil infusion; and phorbol myristate acetate-activated human neutrophil infusion. RESULTS: Both groups receiving activated neutrophils showed significant deterioration in ventricular force, rate of ventricular force development (dF/dt) and rate of ventricular relaxation (-dF/dt), and significant increases in coronary vascular resistance. Myocardial lipid peroxidation was assessed but there was no significant difference among groups. Myocardial prostacyclin production was significantly increased in hearts receiving the phorbol myristate acetate-activated human neutrophil infusion. CONCLUSION: It is concluded that myocardial perfusion with activated neutrophils results in depression of myocardial function and an increase in coronary vascular resistance even in the absence of ischemic/reperfusion injury.

6-Ketoprostaglandin F1 alpha↗
PubMed1990

Nursing models in the curriculum: the nursing degree course at Bristol Polytechnic.

This article discusses the use of nursing models as a basis for curriculum planning in a Nursing degree course. Each module in the course is based on a Nursing model, as are assessment of theoretical aspects and of nursing competencies. Rationales for the structure of the course and choice of models are given, and the article concludes by emphasising the need for continuing evaluation of this way of planning and implementing the curriculum.

Clinical Competence↗
PubMed1990

A screening test for detecting sulfonylureas in plasma.

Hypoglycemia induced by surreptitious sulfonylurea ingestion can be difficult to distinguish from an insulin-secreting tumor. We describe a technique for detecting most of the common sulfonylurea drugs in plasma. After preliminary acidification, and extraction in ether, the residue is reconstituted and injected onto a Versapack high-performance liquid chromatography column. Detection is at 230 nm. This procedure gives good separation of chlorpropamide, glibenclamide, gliclazide, glipizide, and tolbutamide. Results are semiquantitative but the sensitivity of the assay is sufficient to detect and identify clinically active concentrations of all five drugs. It is a rapid and reliable screening test. Four representative case histories are reported in which the screen proved to be of diagnostic value.

Aged↗
PubMed1989

Endogenous dopamine modifies electroresponsiveness of pars compacta cells in the guinea pig substantia nigra in vitro.

In the nigrostriatal pathway, dopamine is released not only from striatal nerve terminals, but also locally from the dendrites of nigrostriatal neurones within the substantia nigra itself. Exogenous dopamine is known to inhibit the firing of these neurones when applied directly to the substantia nigra in micromolar concentrations: but the amounts used are probably much higher than the endogenous concentration of the transmitter. Moreover, the direct, local blockade of nigral dopamine autoreceptors has not been reported to affect the firing rates of these neurones. The electrophysiological effects of endogenous dopamine were therefore examined using intracellular recordings from the substantia nigra in vitro. When slices of the midbrain were pharmacologically depleted of endogenous dopamine, selective membrane properties of nigrostriatal neurones were altered in a manner consistent with the effects of the exogenous transmitter. Similar changes were observed in control slices on exposure to the dopamine antagonist haloperidol. It is concluded that endogenous dopamine normally exerts a tonic influence on the electrical properties of nigrostriatal neurones.

Action Potentials↗
PubMed1989

Pressure ejection of acetylcholinesterase within the guinea-pig substantia nigra has non-classical actions on the pars compacta cells independent of selective receptor and ion channel blockade.

In the substantia nigra, acetylcholinesterase may have a non-classical function unrelated to cholinergic transmission. Acetylcholinesterase is released from the dendrites of dopamine-containing nigrostriatal neurons and has a subsequent action on these cells, independent of hydrolysis of acetylcholine. The aim of this study was to explore further the precise nature of this "non-cholinergic" action of acetylcholinesterase. Acetylcholinesterase was pressure-ejected in the vicinity of the dendrites of putative nigrostriatal neurons in vitro, in near-physiological amounts, and the effects of this treatment on neuronal membrane properties were investigated. It was found that acetylcholinesterase reversibly hyperpolarized the nigrostriatal cell membrane independent of sodium and calcium channel blockade. Acetylcholinesterase pretreated with an irreversible inhibitor (Soman) of its classical catalytic site produced the same hyperpolarizing effect: however, butyrylcholinesterase, which hydrolyses acetylcholine, was inefficacious. These effects persisted in the presence of the dopamine receptor antagonist sulpiride. It is suggested the acetylcholinesterase can facilitate the generation of a long-duration conductance, which enhances the firing of nigrostriatal cells if the neuron is first hyperpolarized. Hence the action of acetylcholinesterase would be to modulate inputs. These actions are independent of direct interaction with acetylcholine and dopamine systems. Hence, in the substantia nigra, acetylcholinesterase might serve as a "neuromodulatory" secretory protein.

Acetylcholinesterase↗
PubMed1989

A possible pacemaker mechanism in pars compacta neurons of the guinea-pig substantia nigra revealed by various ion channel blocking agents.

The membrane properties of pars compacta neurons in the in vitro guinea-pig substantia nigra have been studied in the presence of sodium, calcium and potassium channel blockers. The following properties, which have already been described for dopamine-containing substantia nigra zona compacta neurons were observed: high and low threshold calcium spikes; a calcium-activated potassium-mediated transient; inward rectification. Inward rectification was sensitive to caesium ions. An additional property was seen reminiscent of an "A" current, although resistant to 4-aminopyridine. It is suggested that this outward transient is in fact a calcium activated potassium conductance. Under certain conditions calcium-mediated rhythmic depolarizations were observed. It is suggested that at least two of the properties seen (outward rectification and low threshold calcium spike) could interact to provide the basis for a pacemaker mechanism in pars compacta neurons.

Action Potentials↗
PubMed1989

The effects of gamma-hydroxybutyrate on the membrane properties of guinea-pig pars compacta neurons in the substantia nigra in vitro.

The effects of gamma-hydroxybutyrate have been studied on the membrane properties of pars compacta neurons within the guinea-pig substantia nigra maintained in vitro. The effects of gamma-hydroxybutyrate are to (i) lower input resistance, (ii) hyperpolarize the cell membrane in a dose-dependent manner and (iii) facilitate calcium conductances. These effects are resistant to the blockade of sodium channels with tetrodotoxin and blockade of potassium channels with tetraethylammonium or 4-aminopyridine. Furthermore, these effects are only partially blocked by high doses of the GABA receptor antagonist bicuculline: indeed the effects of the GABA receptor agonist muscimol can be differentiated from those of gamma-hydroxybutyrate in that the latter is sensitive to application of barium ions. The results suggest that gamma-hydroxybutyrate acts to increase utilization of calcium, which in turn leads to an initiation of calcium-dependent events. The functional consequences of these effects of gamma-hydroxybutyrate are discussed with regard to its possible endogenous modulatory actions.

Animals↗
PubMed1989

Developmental coupling of expression of the Igh-linked minor antigen H-40 to membrane immunoglobulin expression.

C.B-20 (Ighb) but not BALB/c (Igha) mice are able to reject BCL1, a spontaneous B cell leukemia of BALB/c origin. The protective immune response is directed toward the minor histocompatibility (H) antigen, H-40, which can be detected by cytotoxic T lymphocytes and is expressed on surface (s) immunoglobulin positive tumor cells including BCL1 as well as sIg+ lymphoblasts activated by lipopolysaccharide. The fact that only sIg+ tumor cells and lymphoblasts express H-40 suggests that sIg itself may be a component involved in CTL recognition of this antigen. However, this possibility was ruled out by demonstrating that removal of sIg from target cells did not prevent H-40-specific CTL recognition. To determine whether H-40 expression was coordinately regulated with that of membrane Ig, we determined whether H-40- sIg- cells acquire H-40 when induced to express sIg. We also transfected a functional mu c and nu region gene into a sIg- lymphoma so that it acquired a sIg+ phenotype. In neither case did such sIg+ cells acquire H-40. Together, these data indicate that H-40 is expressed on B cells representing a particular stage of differentiation that is coincidental with sIg. We previously showed that H-40 and Igh loci are linked on the 12th murine chromosome. In this study we further localized H-40 to a point beyond Aat (formerly Pre-1) near Lm-1, a locus previously described to encode minor H-antigens expressed on lymphomyeloid cells. Thus, H-40 and Lm-1 may represent a gene cluster encoding antigens expressed on subsets of lymphoid and myeloid cells.

Animals↗
PubMed1989

Action research: philosophy, methods and personal experiences.

This article discusses the philosophical basis of action research and the methods by which it may be carried out. These are related to a ward development action research project, and the initial phase of this project is discussed. Methodological and ethical issues arising during the project are considered, and themes emerging from the data are analysed. The action researcher's personal experiences and feelings about being involved in the study are discussed, and this reflexive aspect is drawn together to suggest implications for the next and 'action' stage of the project.

Attitude of Health Personnel↗
PubMed1989

The role of cell immobilization in fermentation technology.

The distinction between immobilized cell fermentation and immobilized cell biocatalysis is seldom made, though they are conceptually quite different. Unlike immobilized enzyme systems, immobilized viable cells can be used to carry out conventional fermentations. Microbial cells which would otherwise be freely dispersed (in almost colloidal suspension) within the fermentation environment can be encouraged to become attached in some way to a support (carrier), thus producing a discrete particulate solid phase. Such immobilization offers several potential advantages of a process engineering nature to the fermentation system. These include ease of handling and of cell separation, and lowering of bulk viscosity, as well as the obvious potential benefits of increased cell concentration.

Biotechnology↗
PubMed1988

Properties of anti-idiotypic T cell lines propagated with syngeneic B lymphocytes. I. T cells bind intact idiotypes and discriminate between the somatic idiotypic variants in a manner similar to the anti-idiotopic antibodies.

We describe the development of T cell lines possessing a binding specificity for syngeneic T15 idiotopes (Id) expressed on phosphorylcholine (PC)-reactive Ig. The lines were obtained by cultivation of BALB/c splenic T cells with T15 Id+ stimulator cells BCg3R-1d, a BALB/c lymphoma transfected with genomic sequences mu and kappa with S107 (T15) variable regions. Resulting Thyl-2+, L3T4+ cell lines depend on the T15 Id+ BCg3R-1d cells for growth and demonstrate the ability to bind TEPC15, a S107 germline-encoded, PC-specific Ig alpha. The specificity of the 125I-TEPC15 binding was studied in a competitive RIA with various unlabeled Ig. The isolated H and L chains of TEPC15 failed to inhibit the 125I-TEPC15 binding, and the T15-, PC-binding proteins M603 (alpha) and M511 (alpha) inhibited the binding either poorly or not at all. Moreover, the T cell lines had a discriminatory binding specificity for various T15+ Ig that are somatic variants of TEPC15 and that differ from each other in discrete, conformational Id (epitopes) detectable with specific monoclonal anti-Id. The T cell lines could be grouped according to their binding patterns, which were comparable to the recognition patterns of certain monoclonal anti-Id. These data suggest the existence of T cells with specificity for serologically-defined determinants of syngeneic idiotypes.

Animals↗
PubMed1988

A study of nurses' knowledge and attitudes about sexuality in health care.

This article discusses a questionnaire study carried out to investigate knowledge and attitudes towards sexuality among 50 trained nurses working in gynaecological and non-gynaecological wards in the U.K. Knowledge levels were low and attitudes were traditional, and the gynaecology nurses' scores showed them to be less knowledgeable and more conservative than other nurses. These findings match those of studies carried out in the U.S.A. in the 1970s. The implications of the study for nurse education are considered, bearing in mind some reservations concerning the research instruments used.

Attitude of Health Personnel↗
PubMed1988

Child sexual abuse prevention: evaluation of a teacher training model.

Teachers are potentially helpful resource persons for large numbers of sexually abused children who may have difficulty disclosing abuse, particularly to family members. In the present study, the effectiveness of a 6-hour teacher training workshop on child sexual abuse prevention was evaluated. Responses of 26 female elementary teachers who participated in the workshop were compared to responses of 19 control teachers on several pre-, post-, and follow-up measures. Relative to controls, trained teachers demonstrated significant increases from pre- to post-testing in knowledge about child sexual abuse and pro-prevention opinions. On a post-only vignettes measure, trained teachers were better able than control teachers to identify behavioral indicators of abuse and suggest appropriate interventions for hypothetical sexually abused children. Over a 6-week follow-up period, trained teachers read more about child abuse than control teachers but did not differ on other behavioral dimensions such as reporting suspected abuse cases. Further research will examine the effects of additional teacher training over an extended follow-up period.

Adult↗