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Biomedical subjects

C Dawson

Publications and source records attributed to C Dawson.

At least 73 records · Page 4Linked to original sources
PubMed1994

Choosing the correct pain relief for extracorporeal lithotripsy.

OBJECTIVES: To determine the best choice of analgesic for patients undergoing lithotripsy, and to attempt to identify factors which might predict which patients are most likely to find the procedure painful. PATIENTS AND METHODS: Sixty patients with stones in the pelvicalyceal system of the kidney were randomized prospectively to undergo lithotripsy with the Dornier MPL9000 lithotripter (Dormier Medical Systems, Marietta, GA, USA) after receiving either diclofenac 100 mg per rectum (n = 30) or pethidine 50 mg intravenously (n = 30) for analgesia. The patients completed a detailed questionnaire prior to treatment, and the level of pain perceived during lithotripsy was monitored using visual analogue scales (VASs). Arterial oxygen saturation (SaO2) was monitored before analgesia was given, throughout the treatment and for 30 min after cessation of treatment. RESULTS: The VASs were available for 56 patients and the results of pulse oximetry for 51 patients. Although a higher kilovoltage was recorded in the group who received pethidine this difference was not significant. Patients who received diclofenac or pethidine alone, showed a non-significant fall of SaO2 30 minutes after the end of treatment, although the largest fall in SaO2 observed with pethidine was 10%. Patients who received diclofenac and pethidine similarly showed a non-significant fall in SaO2. Four patients received intravenous benzodiazepines in addition to pethidine, and in this group there was a dramatic fall in SaO2 which persisted more than 30 min after the end of treatment (P < 0.0027). Diclofenac provided effective analgesia for most of the patients who underwent lithotripsy. Overall 11 patients (18%) required additional analgesia. Diclofenac or pethidine alone, in the doses used in this study, did not cause a significant drop in SaO2 during ESWL. The only response found to be of value in predicting a painful experience was fear of the dentist. CONCLUSIONS: This study shows that modern lithotripsy, in addition to being safe and effective, can be performed as an out-patient procedure using simple non-opiate analgesics. The need for stronger analgesia and/or sedation should be tailored to the needs of the individual patient, although it remains difficult to predict which patients will require such measures.

Adult↗
PubMed1993

Epstein-Barr virus-coded BHRF1 protein, a viral homologue of Bcl-2, protects human B cells from programmed cell death.

Epstein-Barr virus, a human herpesvirus that persists within the B-lymphoid system, can enhance the survival potential of latently infected B cells in vitro through up-regulation of the cellular survival protein Bcl-2. The possibility that an analogous effect is operative in lytically infected cells was suggested by the observation of distant sequence homology between an Epstein-Barr virus-coded early lytic cycle protein, BHRF1, and Bcl-2. Here we show by gene transfer that BHRF1 resembles Bcl-2 both in its subcellular localization and in its capacity to enhance B-cell survival. Thus confocal microscopic analysis of cells acutely cotransfected with BHRF1 and Bcl-2 expression vectors revealed substantial colocalization of the two proteins in the cytoplasm. In subsequent experiments, stable BHRF1 gene transfectants of Burkitt lymphoma cells paralleled Bcl-2 transfectants in their enhanced survival under conditions that induce cell death by apoptosis. Despite their limited sequence conservation, therefore, the two proteins appear to be functionally homologous. We suggest that BHRF1 provides an alternative, Bcl-2-independent, means of enhancing B-cell survival that may operate during the virus lytic cycle.

Animals↗
PubMed1993

Breast disease and the general surgeon. I. Referral of patients with breast problems.

OBJECTIVES: To determine the proportion of all new and follow-up patients referred to general surgical outpatient clinics with breast problems. To ascertain how long these patients wait for an appointment and how many require investigation or admission for operation. To review our management of patients with breast problems in the clinic and to determine the ratio of benign breast disease to malignancy. DESIGN: A 3-month prospective outpatient survey with patient details recorded on questionnaires completed by the medical staff. SETTING: The general surgical outpatient clinics of this firm at Battle Hospital, Reading, and Newbury District Hospital, Berkshire. PATIENTS: Those patients attending the above clinics during the 3-month period 1 October to 31 December 1989. RESULTS: In all, 693 new patients and 554 follow-up patients were seen. Of the new patients, 119, and of the follow-up patients 140 were seen for a breast complaint. At Battle Hospital 16% of all new patients presented with a breast problem, while at Newbury Hospital the figure was 24%. Of the follow-up patients at Battle Hospital, 23% were seen for a breast problem, and 41% at Newbury. The overall median waiting time for a new outpatient appointment was 21 days. No investigations were needed in 22% of the patients. The remaining 93 patients had investigations and a total of 70 mammograms and 53 fine needle aspirations for cytology were performed. The mean cost of investigations per patient investigated was estimated at 27 pounds. Of new patients, 58% were discharged from the clinic after a single consultation, and investigations as necessary. In 79% of the patients admitted for an operation, the decision to admit was made on the basis of the initial history and examination alone. Of new patients, 84% did not need admission and were managed in the clinic. In all, 14 breast carcinomas were diagnosed--12% of new patients with breast problems. CONCLUSIONS: The figures suggest that 24% of new patients and 41% of follow-up patients attending a general surgical clinic are seen for a breast problem. The waiting time for new appointments is unacceptably long. Most new patients do not require admission for an operation. Only 12% of new patients referred with a breast problem were found to have a carcinoma.

Appointments and Schedules↗
PubMed1993

Breast disease and the general surgeon. II. Effect of audit on the referral of patients with breast problems.

OBJECTIVES: To determine the number of patients with breast problems referred to general surgical clinics in a district general hospital and to assess the effect of changes implemented following the previous study on waiting time, investigations performed, and management of the patients. DESIGN: Two prospective outpatient audits with patient details recorded on questionnaires by the medical staff. SETTING: The general surgical outpatient clinics of a single general surgical firm at Newbury District Hospital, Berkshire. PATIENTS: Those patients attending the above clinics during two 3-month periods, 1 October to 31 December 1989 (Study 1), and 16 April to 19 July 1990 (Study 2). RESULTS: Of new referrals, 25% were for a breast problem. The waiting time fell from a median of 22 days in Study 1 to 10 days in Study 2. There was no significant difference between the studies for the proportion of each type of investigation performed. Between 80% and 85% of new patients did not need admission for an operation; however, of those operations performed, 65% were for carcinoma. The number of patients diagnosed as having carcinoma was the same in the two studies. CONCLUSIONS: That 25% of new, and up to 40% of follow-up patients seen in a general surgical clinic have breast problems. Many patients do not regard their symptoms as worrying and will not attend early clinic appointments even if these are offered. Writing to patients and general practitioners with the results of investigations ensures quicker receipt of the diagnosis and treatment plan, and reduces follow-up attendance. Only 15-20% of new patients need admission for an operation, and carcinoma is found in only 13-17%. Open access to the clinics does not result in general practitioners referring patients unnecessarily with breast problems.

Appointments and Schedules↗
PubMed1992

Use of calcium alginate to pack abscess cavities: a controlled clinical trial.

Many conventional dressings are painful when removed, and may be detrimental to healing. In a pilot study ten consecutive abscesses, requiring incision and drainage, were packed with a calcium alginate dressing: this was well tolerated, its removal causing minimal pain. No adverse effects were attributable to its use. A controlled trial was therefore carried out to compare calcium alginate with the more traditional saline-soaked gauze for packing abscess cavities, following incision and drainage. Patients were randomized to receive either calcium alginate (16 patients) or gauze dressing (18 patients). At the first dressing change the patient marked on a linear analogue scale the pain experienced; the nurse noted similarly the ease of removal of the dressing. Calcium alginate was significantly less painful to remove after operation (P less than 0.01), and also easier to remove (P less than 0.01) than gauze dressings. If abscess cavities are packed after incision and drainage, calcium alginate appears to be an improvement on conventional dressings.

Abscess↗
PubMed1991

Memory and attention in patients with senile dementia of the Alzheimer type and in normal elderly subjects.

Previous studies have shown that cholinergic blockade in normal subjects induces impairment of vigilance as well as memory deficits. In the present investigation we have examined the validity of this pharmacological model of dementia by administering a battery of cognitive tasks to patients with mild and moderate senile dementia of the Alzheimer type and to age-matched controls. In contrast to volunteers receiving scopolamine all the mildly demented patients, and half of those moderately affected, performed normally on tests of vigilance whilst exhibiting the expected memory deficits. These data suggest that the mechanism of memory loss in Alzheimer's disease may differ from that found in scopolamine-induced amnesia.

Aged↗
PubMed1991

HIV-1 binding to CD4 T cells does not induce a Ca2+ influx or lead to activation of protein kinases.

The penetration of CD4+ cells by human immunodeficiency virus (HIV) involves a high affinity interaction between the viral attachment protein, gp120, and the cellular receptor, CD4. The mechanism by which the virus penetrates the host cell subsequent to viral binding is unknown. We have investigated the possibility that HIV penetration induces changes in the metabolic state of the infected cell similar to those seen with the perturbation of CD4 cells by monoclonal antibodies (MAb) directed against the CD4 molecule, or with specific antigen-mediated activation. The activation of cellular protein kinases was examined. The basal level of activity was not altered in the presence of HIV. Kinase activity was markedly increased in cells stimulated with phytohemagglutinin (PHA), and was qualitatively and quantitatively changed by a brief exposure to the phorbol ester TPA (12-o-tetradecanoyl phorbol-13-acetate). The phosphorylation state of the CD4 molecule was examined by radioimmunoprecipitation and found to be unaltered by the binding of HIV under conditions in which TPA induced rapid CD4 phosphorylation. The activity of the CD4-associated protein tyrosine kinase p56lck was measured by in vitro assays of 32PO4 incorporation in CD4 immunoprecipitates from HIV-incubated cells. TPA incubation resulted in a rapid loss of CD4-associated p56lck activity, presumably due to dissociation of the enzyme from CD4. Concanavalin A stimulation resulted in a similar change but with a slower time course. However, no change in CD4-associated activity was detected in HIV-incubated cells. We found that Ca2+ influx was not induced by the binding of HIV to CD4+ cells.(ABSTRACT TRUNCATED AT 250 WORDS)

CD4 Antigens↗
PubMed1991

Families: a link or a liability?

Hospitalization in a critical care setting has multiple effects on patients and their families. For patients, it can be a frightening and dehumanizing experience, while families are confronted with stressors that can disrupt normal family functioning. The nurse is the pivotal figure in the health care system who can positively affect family coping through the support offered. With family needs met, they are then strengthened and able to support their family member. This article examines the roles and relationships of families, social support systems, and nurses. Through the framework of social support, nurses provide emotional, instrumental, spiritual, and appraisal assistances to families. This can potentially positively affect the family's adaptation to a stressful situation, and thus the family's ability to provide support to the patient. A case study analysis is described to illustrate the interactions and interventions through a model of family support.

Adaptation, Psychological↗
PubMed1991

A family-centered critical care unit.

Although care of the family has long been a focus of nursing, there has been an increased emphasis in recent years to provide opportunities for families to be an integral part of the hospitalization experience. This has been difficult for many nurses who perceive themselves as competent to care for a patient in "medical crisis" but feel unqualified to provide family care. This article will address issues related to implementing a family-centered philosophy of care in a critical care unit. Implementation strategies that will be discussed include: formulating a staff-led family support group and family committee, instituting a family visitation contract within open visitation parameters, and developing clinicians with expertise in family care. Tools such as a performance plan for a Clinical Nurse II specializing in family care and the family visitation contract will be shared.

Education, Nursing, Continuing↗
PubMed1989

Application of different chromosomal DNA restriction digest fingerprints to specific and subspecific identification of Campylobacter isolates.

Eleven strains comprising representatives of different subspecies, biotypes, and serotypes of Campylobacter jejuni and reference strains of C. coli, C. fetus subsp. fetus, C. hyointestinalis, and C. sputorum subsp. sputorum were studied to assess the utility of different DNA profiles for measuring fine differences between allied bacteria. Strains were compared by analyses of HaeIII and XhoI digest patterns of chromosomal DNA and Southern blot hybridization patterns of XhoI digests obtained with an Escherichia coli 16S + 23S rRNA gene probe. Visual comparisons and numerical analyses of the HaeIII and XhoI digest patterns both revealed clear differences between the five Campylobacter species and between representatives of C. jejuni subspecies and biotypes. Only strains with the same Penner serotype gave identical total digest polymorphisms. The advantages of XhoI total digests and Southern blot hybridization patterns were that they were less complex than the HaeIII patterns and easier to compare visually. However, numerical analysis of XhoI data resulted in reduced discrimination. We conclude that DNA fingerprinting using either HaeIII or XhoI fragment polymorphisms has considerable potential as a generally applicable method for identification of Campylobacter isolates, especially at the infrasubspecific level.

Blotting, Southern↗
PubMed1989

Use of a contraindications checklist by practice nurses performing immunizations at a well child clinic.

At the inception of a general practice well child clinic, a checklist card was introduced into the clinic notes to summarize specific and relative contraindications to immunizations. This card was used by the practice nurses as they ran the immunization procedures during the clinic. A failure on the checklist led to a consultation with the clinic doctor who decided whether to proceed with the immunization. Of 155 immunizations given during the six-month period, only 23 (15%) failed the checklist and required the child to be assessed by the clinic doctor. Of these, nine (39%) were for simple upper respiratory tract infection. All the children were deemed fit to receive immunization. Only one child was found to have a specific contraindication to pertussis. The checklist cards allowed the smooth operation of the immunization procedures by practice nurses who were able to check comprehensively whether there were any contraindications and whether immunizations were being inappropriately refused.

Child Health Services↗
PubMed1988

Detection of genomic variation in Providencia stuartii clinical isolates by analysis of DNA restriction fragment length polymorphisms containing rRNA cistrons.

Chromosomal DNA from 26 strains of Providencia stuartii isolated mainly in hospitals in the United Kingdom and reference strains of P. stuartii, P. rustigianii, and Proteus vulgaris were digested with the restriction endonucleases EcoRI and HindIII. After electrophoresis in agarose gels, the fragments were subjected to Southern blot hybridization analysis with a biotin-labeled cDNA probe transcribed from a mixture of 16S and 23S rRNA from P. stuartii NCTC 11800T. The pattern of bands (the rDNA fingerprint), which depended on restriction fragment length polymorphisms containing rRNA genes, was used as a measure of minor genomic variation within and between species. The P. stuartii clinical isolates had similar total digest patterns, but the rDNA fingerprints revealed some heterogeneity between strains, with EcoRI digests providing better strain discrimination than HindIII. Such rDNA fingerprints comprised between five and seven bands with sizes in the range of 5 to 28 kilobases. The 11 different EcoRI patterns were compared by numerical analysis, and several groups or subgroups of strains were identified. Over half (15 of 26) of the urease-negative isolates (subgroups Aa and Ab) had patterns that differed only by the presence or absence of a 25-kilobase band. Urease-negative strains from other clinical material were more heterogeneous in their patterns. No correlation was apparent between strain pattern group and urease production or geographic location of isolate. The P. stuartii rDNA fingerprints were quite distinct from those of allied Providencia and Proteus species and provided a more sensitive measure of minor genomic differences than total DNA digests did.

DNA Probes↗
PubMed1988

Toronto Alexithymia Scale: relationships with measures of patient self-disclosure and private self-consciousness.

The construct validity of the Toronto Alexithymia Scale (TAS) was tested by correlations with the Patient Self-Disclosure instrument and the Private Self-Consciousness scale in a study of 333 students at a large midwestern university. The TAS was found to be internally consistent and to yield a replicable factor structure. Scores on the TAS correlated negatively with both overall ratings of the importance of such disclosure and scores on the PSC, and positively with perceived difficulty of patient self-disclosure. Results support construct validity of the TAS and suggest a more generally restrictive communicative style among alexithymic individuals than previously thought.

Adolescent↗