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Biomedical subjects

C Thompson

Publications and source records attributed to C Thompson.

At least 91 records · Page 5Linked to original sources
PubMed2000

The dietary habits of idiopathic calcium stone-formers and normal control subjects.

OBJECTIVES: To examine the relationship between 12 macro- and micro-nutrients and the risk of recurrent calcium stone formation by comparing the diets of a large outpatient clinic-based group of patients who had formed calcium-based urinary tract calculi with that of a population-based control group matched for age, gender and body mass index. PATIENTS, SUBJECTS AND METHODS: The dietary intake of 500 patients (cases) randomly selected from the adult population attending an outpatient renal-stone clinic and being evaluated and/or treated for biochemically or radiologically diagnosed calcium-based upper urinary tract calculi were compared with those of 500 control subjects selected to match for age, sex and body mass index from a stratified probability sample of 2212 adults (not institutionalized) living in the same geographical area. RESULTS: Comparing the mean nutritional intakes showed a statistically higher consumption of energy, carbohydrates, sodium, fibre, vitamin C, fat and folic acid among cases than in controls. The intake of calcium, alcohol and vitamin A was significantly higher among the controls. There were no significant differences in the intake of protein, niacin or iron. The results of these comparisons varied when the groups were stratified by sex, age and body mass index. CONCLUSIONS: Dietary risk factors for calcium-based urinary tract calculi are many and complex, and a detailed consideration of sex, age and body mass index is important in interpreting such data. While it is difficult to draw firm conclusions about causes and effects of individual nutrients from the available data, this study indicates a possibly more important role for dietary fat in stone formation than has been previously recognized. This relationship needs to be further explored in relation to urinary risk factors, as it may be possible to advise patients to reduce dietary fat as a prophylactic measure for stone formation. As dietary fat has been associated with cardiovascular diseases and possibly cancer, an overall recommendation to these patients for a low dietary fat intake may be easier to follow.

Adult↗
PubMed2000

Evaluating the reliability and utility of cumulative intake and output.

During times of scarce resources available for providing patient care, it becomes necessary to validate the effectiveness of standard practices that consume caregivers' time and efforts. Three nurse managers of nursing units serving diverse patient populations studied the effectiveness of continuous intake and output in estimating daily fluid balance. They examined 48-hour records of daily weight and intake and output of 73 patients and correlated the two. Their findings suggest that even when caregiver charting compliance is optimal, daily intake and output recording provides unreliable results. The authors recommend daily weights alone be adopted for all patients who are not experiencing acute renal conditions.

Adult↗
PubMed2000

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Journal Article↗
PubMed2000

Intuition and analysis in decision making and choice.

PURPOSE: To discuss the need for a shift in focus from intuitive to more analytic ways of examining both the process and outcomes of professional decisions based on "best evidence." SCOPE: Different assumptions inherent in intuitive and analytic explanations of nurses' decision making are outlined, and the two approaches are compared. The benefits and limitations of such approaches to decision making in nursing and health care are discussed, using available research evidence to show that in most instances the analytical approaches are more effective. CONCLUSIONS: A systematic approach to decision making in health care is needed, so that both health professionals and patients have a means for knowing the basis of decisions about treatment.

Decision Making↗
PubMed2000

Outcome of patients with chronic abdominal pain referred to chronic pain clinic.

OBJECTIVE: We determined the outcome of patients with chronic abdominal pain of unknown etiology referred by gastroenterologists to a chronic pain clinic. METHODS: A retrospective chart review of 43 consecutive patients seen by a university-based gastroenterology group was referred to our Chronic Pain Clinic for evaluation and treatment. Pain character and location, the referring diagnosis, and initial Chronic Pain Clinic diagnosis was compared between responders and nonresponders. Early and long-term pain relief was scored by standard questionnaire. RESULTS: Of the 43 patients with chronic abdominal pain of undetermined etiology, 70% reported complete or substantial pain relief by the end of chronic pain management. Pain character and location and the referring diagnosis were not predictors of pain relief. Long-term pain relief was reported by 35% of patients. CONCLUSION: A substantial group of patients with chronic abdominal pain of unknown etiology benefited from Chronic Pain Clinic services.

Abdominal Pain↗
PubMed2000

Compliance with antidepressant medication in the treatment of major depressive disorder in primary care: a randomized comparison of fluoxetine and a tricyclic antidepressant.

OBJECTIVE: Many claims have been made for superior compliance with selective serotonin reuptake inhibitors (SSRIs) compared with tricyclic antidepressants, but to date meta-analyses have not confirmed reduced dropouts in randomized controlled trials. The authors used a randomized study design to evaluate differential compliance with antidepressant medications in a primary care setting. METHOD: A total of 152 patients treated in 10 primary care practices in the United Kingdom were included in a randomized, open-label, parallel-group study of fluoxetine and dothiepin at therapeutic doses for 12 weeks. Compliance was assessed by using pill count, patient questionnaires, and the Medication Event Monitoring System. RESULTS: The level of compliance with fluoxetine was numerically higher than the level of compliance with dothiepin on all three primary outcome measures, although the differences were not significant. In a secondary analysis using data from the Medication Event Monitoring System, both a survival analysis for length of time without a gap in medicine taking and a derived compliance index showed a significant advantage to fluoxetine. Patients in the fluoxetine group reported superior response on the health transition scale of the 36-item Short-Form Health Survey Questionnaire and numerically greater improvement on the Hamilton Depression Rating Scale. In both treatment arms patients with a superior compliance index were more likely to have improved in Hamilton depression scale scores by the last study visit. CONCLUSIONS: This study supports recent meta-analyses of SSRIs versus tricyclic antidepressants in finding no significant differences in crude indices of compliance between fluoxetine and dothiepin, despite marked differences in side effect profile and dose regimen. However, both a survival analysis and a new measure that takes account of prolonged periods of noncompliance distinguished between the treatments and was associated with improvement in both groups.

Adolescent↗
PubMed2000

Genital herpes simplex typing in genitourinary medicine: 1995-1999.

Retrospective study of all culture-positive first episode genital herpes (HSV) presenting to genitourinary medicine (GUM) over a 4-year period, showing a high prevalence of type 1 (71%) HSV infection, most marked in women. This has implications for counselling patients and for the use of type-specific serological testing.

Adult↗
PubMed2000

Profile of epidermal growth factor receptor (EGFr) expression in human malignancies: effects of exposure to EGF and its biological influence on established human tumour cell lines.

The aim of this study was to compare the profile of EGFr expression in transitional cell carcinoma of the bladder (TCC) and in oral squamous cell carcinoma (OSCC). In addition, to study the influence of EGF stimulation on the expression of major histocompatibility complex class I antigens, placental alkaline phosphatase (PLAP) as well as changes in tumour cell sensitivity to cisplatin using immunocytochemical staining, a colorimetric assay and SDS-gel electrophoresis. The results showed that: a) strong EGFr expression could be seen in 22/88 (27%) cases of TCCs. In oral tumours the values for non-invasive ameloblastoma and invasive OSCC were 4/25 (16%) and 30/41 (73%) respectively. b) EGFr expression in tumour cell lines paralleled that of tumour biopsies. The number of lines expressing high and low EGFr expression amongst TCCs were 4 and 4 and in OSCCs were 3 and 1 respectively. c) Exposure of tumour cell lines to EGF led to: i) an increase in EGFr expression (stimulatory indices SI, ranged from 1.06 to 2.58) for TCCs but a decrease in the case of OSCCs (SI ranged from 0.01 to 0.85). The corresponding SI values for class I antigens were 0.95-1.16 and 0.10-0.84. ii) A significant reduction in expression of PLAP by OSCC cell lines. iii) An increased susceptibility of OSCC cell lines to cisplatin by as much as 14% (p<0.001). These data demonstrated the overexpression of EGFr in a significant proportion of TCCs. As for oral tumours it depended on whether they were of an invasive or non-invasive type. In the invasive cases the majority overexpressed EGFr. The exposure of OSCC but not TCC tumour cells to EGF resulted in down regulation of EGFr and class I antigens. The expression of PLAP was also significantly reduced. Exposure of OSCC cells to EGF resulted in their increased susceptibility to cisplatin. The data supports the notion that the mitogenic activation of some tumour cells by EGF resulted in a reduction of their immune visibility, differentiation status and an increase in chemosensitivity.

Alkaline Phosphatase↗
PubMed2000

Effect of climate and type of storage container on aflatoxin production in corn and its associated risks to wildlife species.

The effects of grain storage containers on aflatoxin production, and the relationship between the level of aflatoxin and the number and weight of fluorescing kernels were determined in corn (Zea maize) stored in controlled climate regimes. Two hundred and forty 100-g samples were held up to 3 mos using four types of storage containers placed in four climates. Storage containers included corn placed in metal cans, paper bags, plastic bags, and paper bags placed in plastic bags. Climates were constant during the duration of the project and included a combination of temperatures and humidities. Temperatures were 29-32 C and 14-18 C; relative humidities were 85-88% and 35-40%. In addition, corn was exposed to environmental conditions conductive for aflatoxin production and 100 g samples were randomly collected, examined under ultraviolet light for fluorescence, and then quantified for aflatoxin levels. Corn samples tested negative for aflatoxin at the beginning of the project. Main (i.e., container, climate, and month) and interactive effects were not observed. Mean levels of aflatoxin ranged from 0 to 151 microg/kg. Aflatoxin was produced regardless of type of storage container, time of storage, and climatic conditions; however, only 8% of the samples produced aflatoxin levels that exceeded 50 microg/kg. Fluorescing corn ranged from 0 to 19 kernels per sample, while aflatoxin levels ranged from 0 to 1,375 microg/kg for the same samples. No relationships were found between the number and weight of fluorescing kernels of corn and aflatoxin levels. The black light test yielded a false negative rate of 23% when in fact the aflatoxin concentrations exceeded 50 microg/kg. Therefore, quantifying fluorescing grain under UV light should not be considered a feasible alternative for aflatoxin testing of grain intended for wildlife.

Aflatoxins↗
PubMed1999

Mutational analysis of avidity and fine specificity of anti-levan antibodies.

Using the polyfructose, bacterial levan, as a model polysaccharide, we analyzed how V regions affect binding in anti-polysaccharide mAbs. Previously, panels of mAb were constructed from bacterial levan-immunized BALB/c and CBA/Ca mice. The BALB/c mAb were mostly germline VHJ606:Vkappa11, and a subset contained presumed somatic mutations in the complementarity-determining regions (CDRs) that correlated with increases in avidity for the beta(2-->1) inulin linkage of levan. The CBA/Ca mAb were more heterogeneous in V gene usage, but a subset of inulin-nonreactive mAb were VHJ606:Vlambda and had VH sequence differences in the CDRs from the VHJ606 regions of the BALB/c mAb. In this report, VHJ606 Abs containing various combinations of specifically mutated H and L chains were produced by engineered transfectants and tested for inulin avidity and levan binding. Two presumed somatic mutations seen in CDRs of the BALB/c hybridomas were shown to directly cause marked increases in avidity for inulin (VH N53H, 9-fold; VL N53I, 20-fold; together, 46-fold) but not for beta(2-->6) levan. Exchange of either positions 50 or 53 in VH or the H3 loop between the BALB/c and CBA/Ca mAb resulted in either fine specificity shift or total loss of bacterial levan binding. Three-dimensional models of the V regions suggested that residues that affect binding to inulin alone are near the edge of the CDR surface, while residues involved with binding both forms of levan and affecting fine specificity are in the VH:VL junctional area.

Amino Acid Sequence↗
PubMed1999

Hard Burst Emission from the Soft Gamma Repeater SGR 1900+14.

We present evidence for burst emission from SGR 1900+14 with a power-law high-energy spectrum extending beyond 500 keV. Unlike previous detections of high-energy photons during bursts from soft gamma repeaters (SGRs), these emissions are not associated with extraordinarily bright flares. Not only is the emission hard, but the spectra are better fitted by D. Band's gamma-ray burst (GRB) function rather than by the traditional optically thin thermal bremsstrahlung model. We find that the spectral evolution within these hard events obeys a hardness/intensity anticorrelation. Temporally, these events are distinct from typical SGR burst emissions in that they are longer ( approximately 1 s) and have relatively smooth profiles. Despite a difference in peak luminosity of greater, similar1011 between these bursts from SGR 1900+14 and cosmological GRBs, there are striking temporal and spectral similarities between the two kinds of bursts, aside from spectral evolution. We outline an interpretation of these events in the context of the magnetar model.

Journal Article↗
PubMed1999

Statistical Properties of SGR 1900+14 Bursts.

We study the statistics of soft gamma repeater (SGR) bursts using a database of 187 events detected with BATSE and 837 events detected with the Rossi X-Ray Timing Explorer Proportional Counter Array; all events are from SGR 1900+14 during its 1998-1999 active phase. We find that the fluence or energy distribution of bursts is consistent with a power law of index 1.66, over 4 orders of magnitude. This scale-free distribution resembles the Gutenberg-Richter law for earthquakes and gives evidence for self-organized criticality in SGRs. The distribution of time intervals between successive bursts from SGR 1900+14 is consistent with a lognormal distribution. There is no correlation between burst intensity and the waiting times till the next burst, but there is some evidence for a correlation between burst intensity and the time elapsed since the previous burst. We also find a correlation between the duration and the energy of the bursts, but with significant scatter. In all these statistical properties, SGR bursts resemble earthquakes and solar flares more closely than they resemble any known accretion-powered or nuclear-powered phenomena. Thus, our analysis lends support to the hypothesis that the energy source for SGR bursts is internal to the neutron star and plausibly magnetic.

Journal Article↗