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Biomedical subjects

R E Thompson

Publications and source records attributed to R E Thompson.

At least 19 recordsLinked to original sources
PubMed2005

Clinical and EEG features of patients with EEG wicket rhythms misdiagnosed with epilepsy.

BACKGROUND: EEG wicket rhythms are 6- to 11-Hz medium-to-high voltage bursts that are sometimes misidentified as epileptogenic activity. The authors determined the clinical and EEG features of patients with wicket rhythms who had been incorrectly diagnosed with epilepsy. METHODS: Electroencephalographers at an epilepsy center re-read EEGs for patients referred for epilepsy management and identified patients with wicket rhythms. On further evaluation, the majority (54%; 25/46) of these patients were found not to have epilepsy. The authors compared the clinical and EEG features for the 25 patients with wickets and nonepileptic episodes with those of age- and sex-matched patients with partial-onset epilepsy using univariate and multivariate analysis. RESULTS: Several features distinguished patients with EEG wicket patterns and nonepileptic episodes (n = 25) from age- and sex-matched patients with epilepsy (n = 25): mid-adult age at onset of episodes (mean 38.4 years vs 19.8 years), prolonged clinical episodes (mean 155 minutes vs 2.3 minutes), and long duration of EEG wicket patterns (mean 0.66 seconds vs 0.11 second spikes). After controlling for other factors, patients without major confusion during episodes were unlikely to have epilepsy. CONCLUSION: Wicket patterns are often interpreted as epileptogenic. This distinctive EEG pattern should be considered in patients with clinical episodes atypical for epilepsy.

Adolescent↗
PubMed2005

Anodic plasma chemical treatment of titanium Schanz screws reduces pin loosening.

OBJECTIVE: This study was designed to assess the benefits of a new Anodic Plasma Chemical calcium-phosphate (APC-CaP) surface treatment on reducing pin track infection and pin loosening in comparison to anodized titanium (Ti) during external fracture fixation. METHODS: A tibial midshaft, transverse, 6-mm gap osteotomy was created in 17 adult female Swiss alpine sheep. The tibia was stabilized with an external fixator and 4 Schanz screws of Ti or APC-CaP-treated Ti. The sheep were examined during a 12-week observation period. Infection was assessed with weekly clinical pin track grading and microbiologic assessment at sacrifice. Pin loosening was assessed by grading for radiolucency on biweekly radiographs and by measuring extraction torque on pin removal. In vivo bending stiffness measurements were performed to determine gap healing. A qualitative histologic assessment of the tissue adjacent to pin sites was also performed. RESULTS: A trend (P = 0.056) for less infection around APC-CaP pins was found at 6 weeks, but the strength of this difference diminished with time. Significantly more radiolucency was found around Ti pins after 8 (P = 0.011) and 12 (P < 0.001) weeks. At all pin sites, the extraction torque for APC-CaP pins was higher than for Ti pins (P = 0.007). No difference in the progression of gap healing was found. Histology showed bone growth at the implant surface in the form of distance osteogenesis for Ti and contact osteogenesis for APC-CaP. CONCLUSIONS: This study has shown that the APC-CaP surface improves the clinical performance of Ti pins with respect to pin loosening and pin track infection.

Animals↗
PubMed2004

Ret-Y a measure of reticulocyte size: a sensitive indicator of iron deficiency anemia.

In this study the size of reticulocytes was measured, reticulocyte-Y (Ret-Y), to distinguish iron deficiency anemia from the anemia of chronic disease using a Sysmex XE2100 cell counter. We evaluated this parameter prospectively in 100 patients seen for the evaluation of anemia. A clinical diagnosis of iron deficiency anemia or anemia of chronic disease was made on the basis of a complete blood count, examination of the peripheral smear, and serum ferritin along with a history and physical examination. We analyzed the sensitivity and specificity of the Ret-Y in relationship to the clinical diagnosis. We also measured serum transferrin receptor levels to use as the gold standard laboratory test for iron deficiency against which we compared the Ret-Y. In 40 normal individuals with normal serum ferritin and transferrin receptor levels the mean Ret-Y was 1874 +/- 178 (1 SD). The mean Ret-Y in the anemia of chronic disease group (n=62) was 1722 +/- 162, not significantly different from normal. The mean Ret-Y value among iron-deficient patients (n=38), was 1407 +/- 136 (P <0.01 vs. the anemia of chronic disease group's Ret-Y value). Receiver operator curves showed that Ret-Y correlated closely to the serum transferrin receptor and was superior to the mean corpuscular volume, and ferritin level, in differentiating the type of anemia. The Ret-Y parameter has the highest overall sensitivity and specificity of the panel of tests routinely used in differentiating iron deficiency anemia from anemia of chronic disease.

Anemia, Iron-Deficiency↗
PubMed2001

The use of alternative therapies by patients with Parkinson's disease.

OBJECTIVE: To determine the prevalence and spectrum of use of alternative therapy (AT) by patients with PD and to determine whether use of AT correlates with demographic, social, or disease-specific characteristics. METHODS: The authors administered a structured questionnaire, by interview, regarding the use of AT to 201 patients with PD. Demographic, social, and disease-specific characteristics were recorded for all patients. RESULTS: Eighty-one patients (40%) used at least one AT. Vitamins and herbs, massage, and acupuncture were most common. Users of AT were younger (p = 0.0021) and had a younger age at onset of PD (p = 0.0011) than nonusers of AT. There was no correlation with sex or race. Patients who used AT had a higher income (p = 0.038) and education level (p = 0.006) than did nonusers of AT. There was no association between the use of AT and the Hoehn and Yahr score, duration of PD, duration of treatment with levodopa, surgery for PD, and presence of fluctuations. CONCLUSIONS: The use of AT is common in patients with PD. The age at onset of PD is the most potent predictor of AT use. There is no association between the use of AT and the severity of PD. The widespread and largely unexamined use of AT for PD requires more attention. This should be directed at testing their safety and efficacy and improving physician and patient knowledge about the potential benefits, costs, limitations, and risks of AT.

Acupuncture Therapy↗
PubMed2001

Robust, high-resolution, whole cell patch-clamp capacitance measurements using square wave stimulation.

High-resolution, whole cell capacitance measurements are usually performed using sine wave stimulation using a single frequency or a sum of two frequencies. We present here a high-resolution technique for whole-cell capacitance measurements based on square-wave stimulation. The square wave represents a sum of sinusoidal frequencies at odd harmonics of the base frequency, the amplitude of which is highest for the base frequency and decreases as the frequency increases. The resulting currents can be analyzed by fitting the current relaxations with exponentials, or by a phase-sensitive detector technique. This method provides a resolution undistinguishable from that of single-frequency sine wave stimulation, and allows for clear separation of changes in capacitance, membrane conductance, and access resistance. In addition, it allows for the analysis of more complex equivalent circuits as associated with the presence of narrow fusion pores during degranulation, tracking many equivalent circuit parameters simultaneously. The method is insensitive to changes in the reversal potential, pipette capacitance, or widely varying cell circuit parameters. It thus provides important advantages in terms of robustness for measuring cell capacitances, and allows analysis of complicated changes of the equivalent circuits.

Animals↗
PubMed2000

Disc lesions and the mechanics of the intervertebral joint complex.

STUDY DESIGN: Correlations between tears in the disc and the mechanics of both the intervertebral joint and vertebral body bone were analyzed. OBJECTIVES: To examine the effect of disc degeneration on the mechanics of spinal motion segments. SUMMARY OF BACKGROUND DATA: Degeneration of the intervertebral disc results in changes to the mechanics of the spine. The actual effect of tear type and size on the mechanics of the intervertebral joint is unknown. METHODS: Thirty spinal specimens (median age, 68 years) were divided into T12-L1, L2-L3, and L4-L5 motion segments. Mechanical tests recorded stiffness in flexion, extension, and torsion. Disc morphology was ascertained by taking three transverse sections of the disc and mapping and measuring the concentric tears, radial tears, and rim lesions. The severity of each tear type within each disc then was quantified. Bone cubes from the adjacent vertebral bodies were tested in compression to determine the elastic moduli and tested to failure in the longitudinal direction. RESULTS: Groups with tears were older and had reduced bone elastic moduli than groups without tears. Extension stiffness for the intact joint tended to increase with increasing tear severity. A decrease in torsional stiffness was present with increased severity of rim lesions at both L2-L3 and L4-L5. CONCLUSIONS: Tears in the intervertebral disc are reflected in a reduction in vertebral bone elastic modulus and in changes in the mechanics of the intervertebral joints in flexion, extension, and torsion.

Aged↗
PubMed2000

Underlying causes and long-term survival in patients with initially unexplained cardiomyopathy.

BACKGROUND: Previous studies of the prognosis of patients with heart failure due to cardiomyopathy categorized patients according to whether they had ischemic or nonischemic disease. The prognostic value of identifying more specific underlying causes of cardiomyopathy is unknown. METHODS: We evaluated the outcomes of 1230 patients with cardiomyopathy. The patients were grouped into the following categories according to underlying cause: idiopathic cardiomyopathy (616 patients), peripartum cardiomyopathy (51); and cardiomyopathy due to myocarditis (111), ischemic heart disease (91), infiltrative myocardial disease (59), hypertension (49), human immunodeficiency virus (HIV) infection (45), connective-tissue disease (39), substance abuse (37), therapy with doxorubicin (15), and other causes (117). Cox proportional-hazards analysis was used to assess the association between the underlying cause of cardiomyopathy and survival. RESULTS: During a mean follow-up of 4.4 years, 417 patients died and 57 underwent cardiac transplantation. As compared with the patients with idiopathic cardiomyopathy, the patients with peripartum cardiomyopathy had better survival (adjusted hazard ratio for death, 0.31; 95 percent confidence interval, 0.09 to 0.98), and survival was significantly worse among the patients with cardiomyopathy due to infiltrative myocardial disease (adjusted hazard ratio, 4.40; 95 percent confidence interval, 3.04 to 6.39), HIV infection (adjusted hazard ratio, 5.86; 95 percent confidence interval, 3.92 to 8.77), therapy with doxorubicin (adjusted hazard ratio, 3.46; 95 percent confidence interval, 1.67 to 7.18), and ischemic heart disease (adjusted hazard ratio, 1.52; 95 percent confidence interval, 1.07 to 2.17). CONCLUSIONS: The underlying cause of heart failure has prognostic value in patients with unexplained cardiomyopathy. Patients with peripartum cardiomyopathy appear to have a better prognosis than those with other forms of cardiomyopathy. Patients with cardiomyopathy due to infiltrative myocardial diseases, HIV infection, or doxorubicin therapy have an especially poor prognosis.

Adult↗
PubMed2000

Detection of microsatellite instability by fluorescence multiplex polymerase chain reaction.

We have created a clinical molecular diagnostic assay to test for microsatellite instability (MSI) at multiple loci simultaneously in paraffin-embedded surgical pathology colon resection specimens. This fluorescent multiplex polymerase chain reaction (PCR) assay analyzes the five primary microsatellite loci recommended at the 1997 National Cancer Institute-sponsored conference on MSI for the identification of MSI or replication errors in colorectal cancer: Bat-25, Bat-26, D2S123, D5S346, and D17S250. Amplicon detection is accomplished by capillary electrophoresis using the ABI 310 Genetic Analyzer. Assay validation compared 18 specimens previously assessed by radioactive PCR and polyacrylamide gel electrophoresis detection to results generated by the reported assay. Germline and tumor DNA samples were amplified in separate multiplex PCR reactions, sized in separate capillary electrophoresis runs, and compared directly to identify novel length alleles in tumor tissue. A concordance of 100% between the two modalities was achieved. The multiplex assay routinely detected a subpopulation of 10% tumor alleles in the presence of 90% normal alleles. A novel statistical model was generated that corroborates the validity of using results generated by analysis of five independent microsatellites to achieve a single overall MSI diagnosis. The assay presented is superior to standard radioactive monoplex PCR, polyacrylamide gel electrophoretic analysis, primarily due to the multiplex PCR format.

Alleles↗
PubMed2000

Use of single nucleotide polymorphisms (SNP) and real-time polymerase chain reaction for bone marrow engraftment analysis.

Allogeneic bone marrow transplant engraftment assays use polymorphisms in the human genome to determine the relative percentages of donor and recipient cells present in the recipient. We describe a novel posttransplant assay approach using single nucleotide polymorphisms (SNPs), the most common type of polymorphism in humans. Using samples of defined genotype, we used real-time polymerase chain reaction (PCR) and allele-specific fluorescent TaqMan probes to assay a SNP of the cytochrome P450 CYP2C9 gene. Standard curves of chimeric mixes showed a linear relationship between the ratio of two alleles and the ratio of their respective fluorophore emission, except for mixes with a low percentage (< 5%) of the less common allele. We validated the SNP real-time PCR assay by comparing it to Southern hybridization analysis, analyzing DNA mixes in a blinded fashion with both methods. The correlation between the two methods was high. We have produced a statistical model that varies allele frequency to predict how many SNPs would be required to produce a functional SNP panel. Additional development will be necessary to produce such a panel of highly informative SNPs for clinical use. A real-time PCR SNP assay may ultimately provide more accurate quantification and shortened turnaround time compared to current post-engraftment assays.

Alleles↗
PubMed1998

Multiple sites of V lambda diversification in cattle.

Ig repertoire diversification in cattle was studied in the ileal Peyer's patch (IPP) follicles of young calves and in the spleens of late first-trimester bovine fetuses. To investigate follicular diversification, individual IPP follicles were isolated by microdissection; VA diversity was examined by RT-PCR and subsequent cloning and sequencing. When 52 intrafollicular sequences from a 4-wk-old calf were determined and compared, two major groups, one of 23 members and the other of 25, could be delineated. An examination of these groups revealed clear genealogic relationships that implicated in situ diversification of V lambda sequences within the confines of an IPP follicle. V lambda expression was also examined in early (95 and 110 gestational day) fetal bovine spleens. Although earlier studies in cattle and sheep implicated the IPP as a likely site of Ab diversification, a close investigation of V lambda sequences in late first-trimester fetal calves revealed that diversity appears in the early fetal spleen before the establishment of a diverse repertoire in the ileum. When the sequences for the fetal spleen were compared with an existing pool of germline sequences, we found evidence of possible gene conversion events and possible untemplated point mutations occurring in sequences recovered from fetal spleens. We conclude that IPP is not the sole site of VA diversification in cattle. Also, as suggested for rabbits, cattle may use both gene conversion and untemplated somatic point mutation to diversify their primary VA repertoire.

Animals↗
PubMed1996

Quality initiatives and health care reform.

Problems associated with health care in the United States will be resolved when the four dimensions of health care reform are addressed: (1) How do we reduce variation and confirm quality care? (2) How do we make necessary/appropriate care accessible to all citizens? (3) How do we pay for health care? and (4) How do we stop the drain of dollars paying for ineffective care? In this article, the authors address the first question about how quality is confirmed. They make six specific recommendations to those MCOs that intend to move beyond just establishing a quality management program.

Cost-Benefit Analysis↗
PubMed1995

Mirror, mirror on the wall: reflections from failure to establish a truly uniform national health care policy.

When the author gazed into the proverbial mirror and asked if the U.S. health care system was the fairest of them all, it shattered. In this article, Thompson tells why the system is broken and what failure to fix it means to physician executives. He suggests that we, as Americans, must reinvent ourselves by realigning our value systems and and stifling our obsession with profit before trying to reinvent health care.

Delivery of Health Care↗
PubMed1995

Re-forming the traditional organization medical staff.

The traditional, two-bylaws-model organized medical staff was created in another age (1919) to serve a simple health care system, controlled by physicians, in which the only players were patients, doctors, nurses, and small hospitals. This medical staff model does not meet the needs of the U.S. health care system of the 1990s. The purpose of this article is to provide the physician executive with a resource to use when he or she is called on to help determine what, if any, changes are needed in his or her organization to make the role of physician leaders more effective. Finding the right answer to this question is part of discovering ways to reduce health care costs without reducing the funds available to pay for direct delivery of health care services. Maintaining traditional, bureaucratic, legalistic organized medical staff activities is a very expensive game that we can no longer afford to play.

Constitution and Bylaws↗
PubMed1994

Elected medical staff leaders: who needs 'em?

Authority, influence, and power are not synonyms. In working with elected medical staff leaders, a physician executive who chooses to exert authority may soon find him- or herself relatively powerless. But one who chooses to downplay authority, to influence through persuasion, and to coach leaders to lead effectively soon generates support for his or her ideas. The need to coax, cajole, explain, persuade, and "seek input" frustrates many leaders in all kinds of organizations. It would be much easier just to order people about. It's so tempting to think: "Who needs 'em? I'm the 'chief physician.' I know what needs to be done. Let's weigh anchor, take her out, and do what it takes to sail those rough, uncharted seas." If you really enjoy sailing a large ship in rough seas without a crew, go right ahead. Or if you think it makes sense to run an organization with only an executive staff and no knowledgeable middle managers, by all means let clinician leaders know that, now that you're aboard, they're just window-dressing. If you can make this approach work, well and good. Your life will be much less complicated, each day will have far fewer frustrations, and progress toward established goals will be much faster. However, given the reality of traditionally thinking physicians, it would be best to keep an up-dated resume in the locked lower left-hand drawer of your desk.

Decision Making, Organizational↗
PubMed1994

Health care reform: Believe it or not, the ball is back in our court.

SYSTEM: Orderly arrangement of parts into a whole; a comprehensive plan. SCENARIO: A series of activities or events. In the 1950s, President Eisenhower warned of the waste and danger inherent in a "military-industrial complex" controlled by elected officials who were professional politicians. In the 1960s, some worried that a similar "medical-industrial complex" could develop and that health care could become a "political football." Sure enough, in the 1970s and '80s, a U.S. health care scenario evolved that is characterized by financial, political, and legal maneuvering rather than by genuine interest in providing dependable medical care on the scariest days of people's lives. If problems of dependability, affordability, and access are truly to be solved, this scenario must change. And until these problems are truly solved, unwelcome pressure on providers will continue. Furthermore, political action can only create a system. The scenario is created by the attitudes, motivations, and actions of health care providers.

Delivery of Health Care↗