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Biomedical subjects

J Richardson

Publications and source records attributed to J Richardson.

At least 55 records · Page 3Linked to original sources
PubMed2001

Pneumocystis carinii cytochrome b mutations are associated with atovaquone exposure in patients with AIDS.

This retrospective cohort study was conducted to determine whether Pneumocystis carinii cytochrome b gene mutations in patients with AIDS and P. carinii pneumonia (PCP) are associated with atovaquone exposure. Portions of the P. carinii cytochrome b genes that were obtained from 60 patients with AIDS and PCP from 6 medical centers between 1995 and 1999 were amplified and sequenced by using polymerase chain reaction. Fifteen patients with previous atovaquone prophylaxis or treatment exposure were matched with 45 patients with no atovaquone exposure. Cytochrome b coenzyme Q binding site mutations were observed in 33% of isolates from patients exposed to atovaquone, compared with 6% from those who were not (P=.018). There was no difference in survival 1 month after treatment between patients with or without cytochrome b mutations (P=.14). Thus, cytochrome b mutations are significantly more common in patients with AIDS and PCP with atovaquone exposure, but the clinical significance of these mutations remains unknown.

Acquired Immunodeficiency Syndrome↗
PubMed2001

Nasogastric feeding in children and adolescents with eating disorders: toward good practice.

OBJECTIVE: This study aimed to provide an insight into the subjective experiences of nasogastric feeding from the perspective of patients with eating disorders and their parents. METHOD: A semistructured self-report questionnaire was completed by patients from two specialist eating disorders units who had received nasogastric feeding. Parents' views were also assessed via a similar self-report questionnaire. RESULTS: Diverse views were expressed by both patients and parents. Some regarded the experience of nasogastric feeding as wholly negative, but acknowledged the lack of suitable alternatives. Others had a more positive view and identified several helpful aspects. CONCLUSION: Reactions were generally more positive than had been anticipated. A number of useful suggestions were made regarding how to improve the procedure. These have informed the development of guidelines for good practice.

Adolescent↗
PubMed2001

Outcome in fracture healing: a review.

This editorial reviews outcome measures in fracture healing. Individually radiological and clinical methods are inaccurate, but together provide a good indicator in clinical practice when a fracture has healed. Other quantitative methods are not practical. Vibrational analysis of fracture healing is complex and limited to research at present. Indirect fracture stiffness measurement is possible and has been used in clinical trials. Pin loosening reduces accuracy. The measurement of direct fracture stiffness has been validated and using this a decrease in re-fracture rate and a reduction of time to independent weight bearing (on average 3 weeks) was found. The system is accurate and simple to use in the clinical setting and allows the rate of healing to be monitored in fractures. Studies using poor outcome measures should be interpreted with care. The study of healing fractures is no exception.

Biomechanical Phenomena↗
PubMed2001

The use of coated paramagnetic particles as a physical label in a magneto-immunoassay.

An ideal label for use in an immunoassay would require no further chemical or electromagnetic stimulation prior to its detection and would be free from interference from the sample matrix. Micron sized paramagnetic particles are able to perturb magnetic fields. This perturbation can be directly detected using a suitable electronic device and is independent of the sample matrix. In this study coated paramagnetic particles were used as a physical label in a non-competitive solid phase "sandwich" assay for the detection of human transferrin. The transferrin acted as a "biological bridge" allowing a dose dependant immobilization of the paramagnetic particles to a polyethylene terephthalate solid phase. Quantitation of the paramagnetic label was achieved using an electronic detection system allowing a linear dose response with a femtomolar detection limit (260 fmol).

Animals↗
PubMed2001

A novel measuring system for the determination of paramagnetic particle labels for use in magneto-immunoassays.

Coated micrometer-sized paramagnetic particles (PMPs) are readily available and widely used in immunoassays, mainly for separation and as a solid phase. We have described in a separate paper a model sandwich assay in which approximately 1 x 10(5) to 1 x 10(6) PMPs (2.8 microm diameter) are immobilised on a plastic strip at the end of the assay. In this paper, we describe the design of an instrument that is capable of determining the number of PMPs on the plastic strip. The paper also describes a method of making standard plastic strips with known numbers of PMPs on them. A strip, when placed in a coil of wire in parallel with a capacitor, causes the resonant frequency of the coil to decrease because of the presence of the PMPs. The decrease in frequency relates directly to the number of PMPs on the strip. A circuit based on a voltage-controlled oscillator and a phase-locked loop is used to accurately measure the resonant frequency of the coil. The instrument is capable of detecting at least 1 x 10(5) PMPs immobilised on a plastic strip and has a linear response (r=0.99) for up to at least 3.33 x 10(6) PMPs. In terms of the iron content of the PMPs, the detection limit is approximately equal to 1.2 microg Fe in the paramagnetic particles and the sensitivity is approximately equal to 3 Hz per microg of Fe. The instrument is small and compact and together with a suitable magneto-immunoassay will have many applications, including near-patient monitoring.

Biosensing Techniques↗
PubMed2001

The role of MRI and nerve root biopsy in the diagnosis of neurosarcoidosis.

OBJECTIVES: Neurological involvement occurs in 5-15% of patients with sarcoidosis and isolated "neurosarcoidosis" occurs in less than 1% of all cases. Classical clinical presentations have been described, such as bilateral facial palsy, but often the disease presents insidiously with varied signs and symptoms. We present a patient who required biopsy of a lumbar nerve root for diagnosis of chronic, progressive neurosarcoidosis and review the literature with an emphasis on diagnosis. METHODS: We have reviewed a patient who presented with signs and symptoms related to infiltration of her meninges and nerve roots by sarcoidosis. All pertinent history and physical information was taken from interviews with the patient and review of her chart. Laboratory, radiographic, and pathological investigations are presented. RESULTS AND CONCLUSIONS: A high index of suspicion is required for the diagnosis of neurosarcoidosis. Gadolinium-enhanced MRI is useful but the findings are often nonspecific, and there should be a low threshold for biopsy whenever the diagnosis is considered.

Biopsy, Needle↗
PubMed2001

EMG biofeedback: the effects of CRF, FR, VR, FI, and VI schedules of reinforcement on the acquisition and extinction of increases in forearm muscle tension.

Biofeedback was used to increase forearm-muscle tension. Feedback was delivered under continuous reinforcement (CRF), variable interval (VI), fixed interval (FI), variable ratio (VR), and fixed ratio (FR) schedules of reinforcement when college students increased their muscle tension (electromyograph, EMG) above a high threshold. There were three daily sessions of feedback, and Session 3 was immediately followed by a session without feedback (extinction). The CRF schedule resulted in the highest EMG, closely followed by the FR and VR schedules, and the lowest EMG scores were produced by the FI and VI schedules. Similarly, the CRF schedule resulted in the greatest amount of time-above-threshold and the VI and FI schedules produced the lowest time-above-threshold. The highest response rates were generated by the FR schedule, followed by the VR schedule. The CRF schedule produced relatively low response rates, comparable to the rates under the VI and FI schedules. Some of the data are consistent with the partial-reinforcement-extinction effect. The present data suggest that different schedules of feedback should be considered in muscle-strengthening-contexts such as during the rehabilitation of muscles following brain damage or peripheral nervous-system injury.

Adolescent↗
PubMed2001

A single-injection, multi-segmental paravertebral block-extension of somatosensory and sympathetic block in volunteers.

BACKGROUND: It is our experience that a deposition of an anesthetic solution in the ventral area of the paravertebral space near the parietal pleura and the sympathetic trunk produces extended unilateral block. Because sympathetic block effects in this extended paravertebral block are not reported yet, we undertook this singly blinded, controlled study on the sympathetic change in volunteers. METHODS: A total of 22 ml 1% lidocaine was injected at the T11 level into the ventral area of the right-sided paravertebral space in 16 volunteers. The distribution of analgesia, heart rate, blood pressure and body temperature (measured by 12 skin sensors) was monitored. On a later occasion the volunteers underwent a control injection of saline. RESULTS: Unilateral analgesia (with no contralateral element) was induced in every subject injected with lidocaine, contrasted with no block induction with saline. Loss of pin-prick sensation was observed within 10 min after injection and involved a mean of 12 (range 8-13) dermatomes. A sympathetic block was indicated by cutaneous temperature increase within at least 6 dermatomes. Increase of arterial blood pressure was obtained in all volunteers with no change in pulse rate. No side effects or complications occurred. Epidural spread of the local anesthetic was unlikely because of the absence of contralateral cutaneous analgesia and temperature increase. CONCLUSION: One-sided extended analgesia (sensory loss) follows the paravertebral injection of lidocaine. A large ipsilateral sympathetic block is observed without change in pulse rate and with no hypotension. These are all characteristics of an optimal regional block.

Adult↗
PubMed2001

Negative pressure pulmonary oedema after cryotherapy for tracheal obstruction.

We report a patient who suffered negative pressure pulmonary oedema because of tracheal obstruction after cryotherapy to granulation tissue in the trachea. The pathophysiology and clinical course of negative pressure pulmonary oedema is described. Though there are reports of negative pressure pulmonary oedema after airway obstruction, to our knowledge this is the first case reported after cryotherapy.

Aged↗
PubMed2001

Spinal endoscopy in chronic low back pain with radiculopathy. A prospective case series.

All 38 patients listed for day-case spinal endoscopy over a 12-month period (April 1998 - April 1999), who had chronic severe low back pain with a radiculopathic element, were studied prospectively. The mean [range] pain duration before treatment was 10.9 [2-26] years and 50% had failed back surgery syndrome. In all patients in whom treatment was completed (n = 34), the pain-generating nerve roots were located through symptom interaction with the patient. All had epidural scar tissue, 14 (41%) having dense adhesions. Mobilisation of adhesions around the nerve root (neuroplasty) was performed so that a pocket was formed for the subsequent placement of bupivacaine, Depomedrone and clonidine. No intra-operative complications occurred and side-effects were minimal. Follow-up over a 12-month period showed statistically significant reductions in pain scores and disability. Spinal endoscopy may be the diagnostic method of choice for epidural fibrosis. It has substantial therapeutic and research potential. Prospective randomised studies are required.

Ambulatory Surgical Procedures↗
PubMed2001

Post-operative epidural analgesia: introducing evidence-based guidelines through an education and assessment process.

The aim of this project was to re-introduce post-operative epidural analgesi on to two orthopaedic wards using an evidence-based practice approach. This was achieved through the provision of appropriate staff education and information, assessment of staff competence, and provision of relevant and appropriate staff support. An education programme was developed which included study days, ward-based teaching and the assessment of competence. The introduction of guidelines followed an audit cycle in order to measure the success of the education programme. All nursing staff involved in the project were asked to complete a questionnaire which assessed their knowledge of caring for patients with postoperative epidural analgesia. This was completed before and following the education programme. The outcome measures were: (i) successful completion of competence-based assessment; (ii) levels of knowledge as assessed by the knowledge questionnaire; and (iii) participant perceptions of the project. The results of the questionnaire demonstrated significant improvements in knowledge following the education programme. Participants commented on the importance of the ward-based teaching. They also felt that pain was controlled more effectively using this method of analgesia.

Analgesia, Epidural↗
PubMed2001

Integrating complementary therapies into health care education: a cautious approach.

The movement of complementary therapy training and education into higher education in the United Kingdom (UK) and the interest in alternative therapeutic approaches within the health professions presents an ideal opportunity for multidisciplinary teaching and shared learning. The diversity and similarities of complementary therapies and areas of convergence with conventional healthcare practice can be explored. The recent publication of the House of Lords Select Committee on Science and Technology report on complementary and alternative medicine (HL Paper 123) provides a broader context for discussion and makes specific recommendations about regulation, education and research in the UK. This paper considers the appropriateness of integrating complementary therapies into education for conventional healthcare practitioners, what we should integrate, and when might be the most appropriate time in the education of healthcare practitioners to introduce different therapeutic modalities and their respective philosophical languages. Rather than present a range of solutions, the paper raises some fundamental issues that are central to the integration of complementary therapeutic approaches. If these issues are neglected as we hurry to incorporate different 'techniques' into our conventional practice, we may simply be left with additional tools that we are ill equipped to use.

Complementary Therapies↗
PubMed2001

Developing and evaluating complementary therapy services: Part 1. Establishing service provision through the use of evidence and consensus development.

The integration of complementary therapies within the British National Health Service (NHS) in the context of limited evidence of effectiveness has been much debated, as has the need for the provision of health services to be more evidence-based. In June 1994, a project was launched within a South-East London NHS Hospital Trust to introduce complementary therapy (acupuncture, homeopathy, and osteopathy), in the context of an evaluation program. This followed approximately 4 years of working toward raising the profile of complementary therapies within the hospital through study days, workshops, and providing a massage and osteopathic service for staff. A survey of local general practitioners highlighted areas of complementary therapy provision and interest in referring patients to a hospital-based service. A steering group was established to draw together a proposal for funding the service. Evidence for the effectiveness of acupuncture, homeopathy, and osteopathy was presented at a multidisciplinary seminar. A consensus development process, using a modified Delphi technique to establish referral indicators followed this. This study provides a useful model of service development in the absence of good quality evidence for the effectiveness of clinical interventions.

Attitude of Health Personnel↗
PubMed2001

Developing and evaluating complementary therapy services: part 2. Examining the effects of treatment on health status.

OBJECTIVES: To investigate the effect on patient health status of an outpatient service providing acupuncture, osteopathy, and homeopathy. DESIGN: Pragmatic quasiexperimental design with waiting-list control group. SETTING: A district general hospital in the United Kingdom. SUBJECTS: All patients referred to the service during the study period. OUTCOME MEASURES: The Short Form 36-Item Health Status Survey (SF-36). RESULTS: With the exception of the Physical Functioning scale, statistical differences in scores were found between the treatment and control group on all SF-36 scales. Sensitivity analysis designed to deal with nonresponse supports the robustness of the results. CONCLUSION: This study provides evidence for the effectiveness of an outpatient acupuncture, osteopathy and homeopathy service in terms of benefits to patients' health status.

Acupuncture↗
PubMed2001

The Mef2c gene is a direct transcriptional target of myogenic bHLH and MEF2 proteins during skeletal muscle development.

Members of the MEF2 family of transcription factors are upregulated during skeletal muscle differentiation and cooperate with the MyoD family of myogenic basic helix-loop-helix (bHLH) transcription factors to control the expression of muscle-specific genes. To determine the mechanisms that regulate MEF2 gene expression during skeletal muscle development, we analyzed the mouse Mef2c gene for cis-regulatory elements that direct expression in the skeletal muscle lineage in vivo. We describe a skeletal muscle-specific control region for Mef2c that is sufficient to direct lacZ reporter gene expression in a pattern that recapitulates that of the endogenous Mef2c gene in skeletal muscle during pre- and postnatal development. This control region is a direct target for the binding of myogenic bHLH and MEF2 proteins. Mutagenesis of the Mef2c control region shows that a binding site for myogenic bHLH proteins is essential for expression at all stages of skeletal muscle development, whereas an adjacent MEF2 binding site is required for maintenance but not for initiation of Mef2c transcription. Our findings reveal the existence of a regulatory circuit between these two classes of transcription factors that induces, amplifies and maintains their expression during skeletal muscle development.

Animals↗
PubMed2001

Experience and covariates of depressive symptoms among a cohort of HIV infected women.

OBJECTIVES: The objectives of this study are to assess (a) the level of depressive symptoms among a cohort of HIV infected women and comparable controls and (b) the relationship with covariates including socioeconomic status, substance use, social relations, disease status. METHODS: Participants were enrolled in the Women's Interagency HIV Study (WIHS). Depressive symptoms were measured using the Center for Epidemiological Studies Depression Scale (CESD). Data from 1993 HIV seropositive and 551 seronegative women are presented. RESULTS: Of HIV positive women 57.7% of HIV positive women scored 16 or higher on the CESD (ns) as compared to 55.0% of HIV negative women; at a cutoff of 23, the percents were 40.4% and 35.9% respectively (p = .06). The mean score was high 19.8 but not significantly different between groups. Scores were higher among women who had less education, lower income, were of Hispanic ethnicity, used alcohol or drugs, experienced domestic abuse, had more than one partner, or had less supportive relationships. Among infected women, higher CESD scores were not significantly associated with CD4 cell count but were elevated for self-reported Class C AIDS defining clinical conditions. CONCLUSIONS: The scores on the CESD were elevated for both HIV positive and HIV negative women and the differences between the groups were small. Lower socioeconomic status and social support and higher substance use and domestic abuse were associated with depressive symptoms similarly for both groups.

Analysis of Variance↗
PubMed2001

A comparison of the Assessment of Quality of Life (AQoL) with four other generic utility instruments.

As part of the validation of the Assessment of Quality of Life (AQoL) instrument comparisons were made between five multiattribute utility (MAU) instruments, each purporting to measure health-related quality of life (HRQoL). These were the AQoL, the Canadian Health Utilities Index (HUI) 3, the Finnish 15D, the EQ-5D (formerly the EuroQoL) and the SF6D (derived from the SF-36). The paper compares absolute utility scores, instrument sensitivity, and incremental differences in measured utility between different instruments predicted by different individuals. The AQoL predicted utilities are similar to those from the HUI3 and EQ-5D. By contrast the 15D and SF6D predict systematically higher utilities, and the differences between individuals are significantly smaller. There is some evidence that the AQoL has greater sensitivity to health states than other instruments. It is concluded that at present no single MAU instrument can claim to be the 'gold standard', and that researchers should select an instrument sensitive to the health states they are investigating. Caution should be exercised in treating any of the instrument scores as representing a trade-off between length of life and HRQoL.

Adult↗