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Biomedical subjects

J McDowell

Publications and source records attributed to J McDowell.

At least 19 recordsLinked to original sources
PubMed2003

Gastrointestinal symptoms are more intense in morbidly obese patients.

BACKGROUND: Laparoscopic Roux-en-Y gastric bypass is an effective treatment for morbid obesity. However, little information is available on gastrointestinal (GI) symptomatology in this population. This study compares GI symptoms in morbidly obese patients to that of control subjects. METHODS: A previously validated, 19-point GI symptom questionnaire was administered prospectively to each patient seen for surgical consultation for morbid obesity. The symptoms were then grouped into 6 clusters as follows: (1) abdominal pain, (2) irritable bowel, (3) GERD, (4) reflux, (5) sleep disturbance, (6) dysphagia. The result of each cluster of symptoms expressed as mean +/- standard deviation of obese versus control is compared using student's t-test with significance p = 0.05. RESULTS: Forty-three patients (40 female, 3 male) age 37.3 +/- 8.6 with BMI 47.8 +/- 4.9, and 36 healthy control subjects (23 female, 13 male), age 39.8 +/- 11.2, completed the questionnaire. Results of each cluster for morbid obese vs control subjects are expressed as mean +/- standard deviation: Abdominal pain 25.3 +/- 18.0 vs 12.1 +/- 11.4, p = 0.0002; irritable bowel 23.0 +/- 14.8 vs 15.6 +/- 13.3, p = 0.02; GERD 40.3 +/- 18.9 vs 22.3 +/- 16.1, p = 0.0001; reflux 29.9 +/- 19.0 vs 11.8 +/- 13.4, p = 0.0001; sleep disturbance 50.6 +/- 28.9 vs 32.9 +/- 26.8, p = 0.006; dysphagia 10.9 +/- 15.6 vs 7.2 +/- 10.6, p = NS. CONCLUSIONS: Morbidly obese patients experience more intense GI symptoms than normal subjects, whereas dysphagia is equivalent to normal subjects. These data may be important in counseling patients and understanding that their complaints are legitimate. Follow-up in the postoperative period is needed to determine if these symptoms are improved with an operation.

Abdominal Pain↗
PubMed2002

Increased non-transferrin bound iron in plasma-depleted SAG-M red blood cell units.

BACKGROUND AND OBJECTIVES: Non-transferrin bound iron (NTBI) is associated with increased morbidity in a number of transfusion-dependent disease states such as the severe haemoglobinopathies. We hypothesized that this may be related to excess NTBI present in plasma-depleted red blood cell units that are free of clear haemolysis. MATERIALS AND METHODS: The level of NTBI was determined using the bleomycin assay in samples from 20 stored plasma-depleted red cell units, at approximate 5-day intervals up to day 33 after donation. Forty units of fresh-frozen plasma (FFP) and 40 units of platelet concentrates were used as negative controls, and samples from 12 units of FFP were also serially assessed. RESULTS: Median [interquartile range (IQR)] NTBI was 0 microm (0-0.35) in samples taken from units 3-10 days after donation. Thereafter, the levels of NTBI increased, becoming significant (median 3.05; IQR: 0.05-6.7 microm) 17-22 days after donation. After 30 days, NTBI was detectable in all red cell units. NTBI was undetectable in platelet concentrates and FFP. CONCLUSIONS: Increased levels of NTBI become detectable 17-22 days after donation and increase further with storage time. This excess NTBI may promote bacterial infection in iron-loaded individuals.

Bacterial Infections↗
PubMed2002

Pharmacodynamics of abacavir in an in vitro hollow-fiber model system.

Abacavir is a potent new carbocyclic nucleoside analogue. We employed our hollow-fiber pharmacodynamic modeling system to examine the antiretroviral effects of different abacavir exposures, as well as the impact of the schedule of drug administration on efficacy. Dose ranging of abacavir revealed that a concentration of four times the 50% effective concentration (EC(50)) (approximately the EC(95)) was required to inhibit the replication of human immunodeficiency virus type 1 (HIV-1) (strain MN) either in a continuous-infusion hollow-fiber experiment or in a classical tissue culture flask experiment. In contrast to earlier work with another drug class (HIV-1 protease inhibitors), addition of physiological amounts of the human drug binding proteins albumin and alpha(1) acid glycoprotein revealed that there was little impact on the antiviral effect of the drug. Comparison of equivalent exposures (an area under the concentration-time curve [AUC] developed by approximately 500 mg per day of orally administered abacavir), either in a continuous-infusion mode or as a single oral dose of abacavir, demonstrated no difference in the ability to suppress either strain III(B) or strain MN. Comparison of administration of 250 mg every 12 h (q12h) versus once-daily administration of 500 mg for strain MN again showed no significant difference in suppressive effect. These experiments were carried out over 8 to 15 days. Because of these promising initial results, we extended the experiment to 30 days and examined three different schedules of administration that generated the same AUC at 24 h (AUC(24)): 300 mg q12h, 600 mg q24h, and 1,200 mg q48h. The aim of the last of these regimens was to definitively demonstrate schedule failure. There was little difference between the 1,200-mg q48h treatment group and the untreated control at 30 days. Likewise, there was little difference between the 600-mg q24h and 300-mg q12h treatment groups. However, at circa day 18 of the experiment, there was a small increase in viral output of p24 in the once-daily dosing unit. Examination of virus from all groups demonstrated no phenotypic or genotypic differences. The small difference in hollow-fiber unit p24 in the once-daily dosing group was not due to emergence of resistance over the 30-day single-drug exposure. We conclude that the dose of abacavir currently being studied in clinical trials (300 mg orally q12h) will be efficacious for the majority of sensitive clinical isolates of HIV-1. These in vitro data also suggest that this drug may be able to be administered to patients on a once-daily basis at a dose of 600 mg.

Anti-HIV Agents↗
PubMed2000

The lived experience of the oncology clinical nurse specialist.

The purpose of this study was to explore what was important and what was unique in the experience of the oncology clinical nurse specialist (OCNS). The sample included eight clinical nurse specialists from one geographical area. One to one interviews focused on reflection on two critical incidents from the OCNSs' own clinical experience: one which they thought had gone particularly well and one that had not gone well. Thematic analysis of the OCNS narratives revealed the main themes of uncertain ground, boundaries, support, and reflective practice. Issues which evolved from thematic analysis were related to the developmental needs of the OCNSs involved in the study. Some aspects of the uniqueness of the role was apparent. Recommendations for further research are made.

Humans↗
PubMed2000

Rheumatology telephone helplines: an activity analysis. South and West of England Rheumatology Consortium.

BACKGROUND: Anecdotal evidence suggests that the services offered by rheumatology telephone helplines in the UK vary widely between NHS Trusts because of the lack of national or European guidelines. OBJECTIVE: To conduct an activity analysis of six NHS Trust rheumatology telephone helplines in the south and west of England. METHODS: Serial data were collected on the first 100 calls received on or after 1 January 1999 by six rheumatology helplines in the south and west of England. Background information was gathered on the management, availability, setting and purpose of each helpline. Data on the time taken to manage these calls and patient satisfaction were not collected. RESULTS: Patients with rheumatoid arthritis were the major users and no significant differences were found in the outcome of their calls between centres, but wide variations were revealed in the management of the helplines, the populations they serve and the services they offer. CONCLUSION: The rheumatology helpline services in six NHS Trusts in the south and west of England were shown to be the same in name only. They lacked uniformity in the delivery of care and accessibility to relevant patient groups. The geographical variation in service delivery may result in patient dissatisfaction and confusion if a number of hospitals are attended over the course of a patient's chronic disease. Further research is required to identify the helpline needs of the broader rheumatology population, patient satisfaction, outcomes and system costs, and to progress towards the development of national and European guidelines.

Aged↗
PubMed1999

Linkage of a composite inhibitory phenotype to a chromosome 22q locus in eight Utah families.

Eight Utah multigenerational families, each with three to six cases of schizophrenia, were phenotyped with two specific measures of inhibitory neurophysiological functioning, P50 auditory sensory gating (P50), and antisaccade ocular motor performance (AS). A genomewide linkage analysis was performed to screen for loci underlying a qualitative phenotype combining the P50 and AS measures. For this composite inhibitory phenotype, the strongest evidence for linkage was to the D22s315 marker on chromosome 22q (lod score = 3.55, theta = 0) under an autosomal dominant model. Simulation analyses indicate that this 3.55 lod score is unlikely to represent a false positive result. Lod scores were 2.0 or greater for markers flanking D22s315. A nonparametric linkage (NPL) analysis of the chromosome 22 data showed evidence for allele sharing over the broad region surrounding D22s315 with a maximum NPL score of 3.83 (p = .002) for all pedigrees combined.

Acoustic Stimulation↗
PubMed1999

Pain and the administration of analgesia: what nurses say.

Pain of moderate to severe intensity continues to be an important problem for many hospitalized patients. Nurses spend more time with patients than any other health professional group and have a key role to play in the management of patients' pain. This paper reports the findings from a series of focus group interviews which were undertaken to explore nurses' perceptions regarding pain and the administration of narcotic analgesia. Themes identified from participants' comments related to (1) the pivotal role of nurses in pain management; (2) nursing assessment and pain management decisions (3) individual factors influencing nurses' pain management decisions and (4) the influence of others on nurses' pain management decisions.

Analgesics, Opioid↗
PubMed1998

Health-related quality of life in chronic disorders: a comparison across studies using the MOS SF-36.

The purpose of this report is to examine health-related quality of life (HRQoL) as measured by the Medical Outcomes Study Short Form-36, across patient populations with chronic disorders and to compare quality of life (QoL) in these subjects with normative data on healthy persons. Six studies, within the Center for Research in Chronic Disorders at the University of Pittsburgh School of Nursing, in patients with urinary incontinence, prostate cancer, chronic obstructive pulmonary disease (COPD), acquired immune deficiency syndrome (AIDS), fibromyalgia and hyperlipidaemia provided the data for analysis. The results demonstrated that not only did the prostate cancer and hyperlipidaemia patients have the highest QoL across the chronic disorders, but their QoL was comparable to normative data on healthy persons. Homebound, elderly, incontinent patients had the lowest QoL for physical functioning, whereas patients hospitalized with AIDS had the lowest QoL in general health and social functioning. Patients with COPD had the lowest QoL in role-physical, role-emotional and mental health. Patients with fibromyalgia had the lowest QoL in bodily pain and vitality. Compared to normative data, patients with urinary incontinence, COPD, AIDS and fibromyalgia generally had lower QoL. Prostate cancer and hyperlipidaemia patients had QoL comparable to normative data. Compared to normative data, patients with urinary incontinence, COPD, AIDS and fibromyalgia had more variability for role-emotional. AIDS patients had more variability on physical functioning, bodily pain and social functioning compared to the normative data. These data suggest that patients with various chronic disorders may have QoL that is lower in most domains compared to a healthy population. However, there may be differences in the domains affected as well as the extent of variation across specific chronic disorders.

Aged↗
PubMed1998

Evaluation of a course for charge nurses on caring for people with dementia.

The provision by nurses of appropriate levels of care for people with dementia is considered to be adversely affected by the inadequate provision of post basic education. This paper reports on a study that seeks to evaluate the effectiveness of a brief educational programme for charge nurses caring for people with dementia. In addition it focuses on behavioural change resulting from the course, for example, the degree of involvement of relatives in the care of their family member. The course is seen as a model for short courses for nurses working in this area. Qualitative methodology was utilized involving questionnaires and focused group interviews. The evaluation of the course incorporated pre- and post-test design. The study identified factors that enhanced the charge nurses' educational experience. These factors included a course design incorporating andragogical teaching methods and the implementation of an action plan. The study also highlighted problems experienced by charge nurses in implementing an action plan. The action plan demonstrated that the type of involvement of relatives is more complex than presupposed and depended on such factors as the fear experienced by the relative of being left with the responsibility to care for their family member should they offer to contribute to their care in hospital. Recommendations for the design of future courses are made.

Dementia↗
PubMed1998

Dental caries prevalence and treatment need in Chiriqui Province, Panama.

A pathfinder pilot survey was conducted in rural Chiriqui Province, Panama, using standard WHO methodology, in order to estimate dental caries prevalence and treatment need. Examinations for caries and treatment need were performed by six trained, experienced examiners. From a convenience sample of 2,597 subjects, a stratified cluster sample was constructed using index ages 12 and 15 years and age groups 35-44 and 65-74 years. The results showed a mean Decayed, Missing and Filled Teeth index (DMFT) of 4.08 for 12 year olds, 6.40 for 15 year olds, 13.20 for the 35-44 age group, and 18.88 for the 65-74 age group (P < 0.001). No statistically significant differences by gender were found. These findings rank rural Panama with Mexico and Haiti when compared to the results of other Central American community studies. The percentage of caries free 12 year olds was 6.8 per cent. Of the total sample, 74.7 per cent of individuals would require one or multiple surface restorations and 47.9 per cent would require at least one extraction. Restorative need was greatest in the 15 year olds. The severity of dental caries in this sample was moderately severe and the treatment need extraordinarily high.

Adolescent↗
PubMed1998

Nucleoside analog 1592U89 and human immunodeficiency virus protease inhibitor 141W94 are synergistic in vitro.

The use of combinations of anti-human immunodeficiency virus (anti-HIV) agents targeted to different molecular targets will most likely result in increased viral suppression and may also delay or prevent the emergence of resistant HIV strains. The purpose of the present study was to develop information on the in vitro anti-HIV activities of combinations of the reverse transcriptase inhibitor 1592U89 and the protease inhibitor 141W94 to help guide the choice of dosages in clinical trials. Triplicate in vitro dose-response matrices were prepared with MT-2 cells infected with HIV type 1 (HIV-1) strain IIIB. In order to account for the effects of protein binding, tissue culture medium with 10% fetal bovine serum was supplemented with the human serum proteins alpha1 acid glycoprotein (1 mg/ml) and albumin (40 mg/ml). The three-dimensional drug interaction surface for 1592U89 and 141W94 was constructed with the program MacSynergy II. As analyzed relative to a Bliss Independence null reference model, this combination was synergistic, with volumes of synergy exceeding 100 (99% confidence). Analysis of the data set with a fully parametric form of an equation for the quantitation of drug interaction developed by Greco et al. (W. R. Greco, G. Bravo, and J. C. Parsons, Pharmacol. Rev. 47:331-385, 1995) resulted in an interaction term statistically significantly greater than 0.0, indicating true synergy. Both methods concur that this combination is significantly synergistic. These data, with favorable findings from phase I/II trials for each drug alone, suggest that the combination of 1592U89 plus 141W94 should be further evaluated in clinical trials.

Anti-HIV Agents↗
PubMed1997

Gingival microcirculation response to tooth brushing measured by laser Doppler flowmetry.

This study quantified changes in blood flow following tooth brushing, using laser Doppler flowmetry (LDF). Twenty subjects had polysiloxane stents fabricated with openings to permit placement of the LDF probe on the mesial papillae of 6 teeth. Probing depth, plaque index, and gingival index were recorded and subjects instructed in brushing. LDF initially recorded a 30 second baseline blood flow. The stent was removed and subjects brushed the site for either 3 or 10 seconds. The stent was repositioned and recordings again taken, followed by a control reading. The process was repeated 4 weeks later. Correlations between baseline and control readings were 0.585 (P < 0.001) at the first visit, and 0.654 (P < 0.001) at the return visit. The mean control blood flow was 156.4 perfusion units. The 3 and 10 second brushing increased the mean value 22.6 units and 21.2 units respectively (both P < 0.001). Tooth brushing for both 3 and 10 seconds significantly increased gingival blood flow in the papillary gingiva of healthy individuals.

Adult↗
PubMed1995

Mice deficient in IL-1 beta-converting enzyme are defective in production of mature IL-1 beta and resistant to endotoxic shock.

IL-1 beta-converting enzyme (ICE) cleaves pro-IL-1 beta to generate mature IL-1 beta. ICE is homologous to other proteins that have been implicated in apoptosis, including CED-3 and Nedd-2/lch-1. We generated ICE-deficient mice and observed that they are overtly normal but have a major defect in the production of mature IL-1 beta after stimulation with lipopolysaccharide. IL-1 alpha production is also impaired. ICE-deficient mice are resistant to endotoxic shock. Thymocytes and macrophages from the ICE-deficient animals undergo apoptosis normally. ICE therefore plays a dominant role in the generation of mature IL-1 beta, a previously unsuspected role in production of IL-1 alpha, but has no autonomous function in apoptosis.

Animals↗
PubMed1994

Case report.

Explore the source record for details and available documents.

Child↗
PubMed1993

Pediatric infection with the human immunodeficiency virus.

While rates of infection with the HIV virus are decreasing, the number of children infected continues to increase. There are multiple implications for the practicing pediatric dentist. Many of these children will seek or be referred by other health care providers for treatment of resulting oral pathology. Dentists must be prepared to provide dental services to the HIV-infected child.

AIDS-Related Opportunistic Infections↗
PubMed1991

Repair of cartilage lesions using biological implants. A comparative histological and biomechanical study in goats.

We report the experimental use of three different biological implants to restore articular surface defects: glutaraldehyde-fixed bovine meniscal xenograft, glutaraldehyde-fixed bovine costal cartilage xenograft, and viable osteochondral allografts. The grafts were implanted in the knees of 19 goats who were allowed free-field activity and were studied for up to one year. The natural articular surfaces of meniscal fibrocartilage provided excellent articular surfaces at all times. Equally good articular surfaces were restored by host tissue growth covering costal cartilage grafts at six months, but by 12 months this surface had degenerated. The majority of the allografts survived and integrated with the host at six months, but many showed signs of failure at 12 months. Only three out of seven ungrafted defects healed completely at six months and the healed surfaces were degenerating at 12 months.

Animals↗