Stephen L. Hillis

Effects of the transcendental meditation program on adaptive mechanisms : Changes in hormone levels and responses to stress after 4 months of practice

Stress has been implicated in both somatic and mental disorders. The mechanisms by which stress leads to poor health are largely unknown. However, studies in animals suggest that chronic stress causes high basal cortisol and low cortisol response to acute stressors and that such changes may contribute to disease. Previous studies of the Transcendental Meditation (TM) technique as a possible means of countering effects of stress have reported altered levels of several hormones both during the practice and longitudinally after regular practice of this technique. In this prospective, random assignment study, changes in baseline levels and acute responses to laboratory stressors were examined for four hormones-cortisol, growth hormone, thyroid-stimulating hormone and testosterone-before and after 4 months of either the TM technique or a stress education control condition. At pre- and post-test, blood was withdrawn continuously through an indwelling catheter, and plasma or serum samples were frozen for later analysis by radioimmunoassay. The results showed significantly different changes for the two groups, or trends toward significance, for each hormone over the 4 months. In the TM group, but not in the controls, basal cortisol level and average cortisol across the stress session decreased from pre- to post-test. Cortisol responsiveness to stressors, however, increased in the TM group compared to controls. The baselines and/or stress responsiveness for TSH and GH changed in opposite directions for the groups, as did the testosterone baseline. Overall, the cortisol and testosterone results appear to support previous data suggesting that repeated practice of the TM technique reverses effects of chronic stress significant for health. The observed group difference in the change of GH regulation may derive from the cortisol differences, while the TSH results are not related easily to earlier findings on the effects of chronic stress.

Recent Developments in the Dorfman-Berbaum-Metz Procedure for Multireader ROC Study Analysis

RATIONALE AND OBJECTIVES The Dorfman-Berbaum-Metz (DBM) method has been one of the most popular methods for analyzing multireader receiver-operating characteristic (ROC) studies since it was proposed in 1992. Despite its popularity, the original procedure has several drawbacks: it is limited to jackknife accuracy estimates, it is substantially conservative, and it is not based on a satisfactory conceptual or theoretical model. Recently, solutions to these problems have been presented in three papers. Our purpose is to summarize and provide an overview of these recent developments. MATERIALS AND METHODS We present and discuss the recently proposed solutions for the various drawbacks of the original DBM method. RESULTS We compare the solutions in a simulation study and find that they result in improved performance for the DBM procedure. We also compare the solutions using two real data studies and find that the modified DBM procedure that incorporates these solutions yields more significant results and clearer interpretations of the variance component parameters than the original DBM procedure. CONCLUSIONS We recommend using the modified DBM procedure that incorporates the recent developments.

The Neuropathic Diabetic Foot Ulcer Microbiome Is Associated With Clinical Factors

Nonhealing diabetic foot ulcers (DFUs) are a common and costly complication of diabetes. Microbial burden, or “bioburden,” is believed to underlie delayed healing, although little is known of those clinical factors that may influence microbial load, diversity, and/or pathogenicity. We profiled the microbiomes of neuropathic nonischemic DFUs without clinical evidence of infection in 52 individuals using high-throughput sequencing of the bacterial 16S ribosomal RNA gene. Comparatively, wound cultures, the standard diagnostic in the clinic, vastly underrepresent microbial load, microbial diversity, and the presence of potential pathogens. DFU microbiomes were heterogeneous, even in our tightly restricted study population, but partitioned into three clusters distinguished primarily by dominant bacteria and diversity. Ulcer depth was associated with ulcer cluster, positively correlated with abundance of anaerobic bacteria, and negatively correlated with abundance of Staphylococcus. Ulcer duration was positively correlated with bacterial diversity, species richness, and relative abundance of Proteobacteria, but was negatively correlated with relative abundance of Staphylococcus. Finally, poor glycemic control was associated with ulcer cluster, with poorest median glycemic control concentrating to Staphylococcus-rich and Streptococcus-rich ulcer clusters. Analyses of microbial community membership and structure may provide the most useful metrics in prospective studies to delineate problematic bioburden from benign colonization that can then be used to drive clinical treatment.

Diagnostic validity of three swab techniques for identifying chronic wound infection

This study examined the diagnostic validity of three different swab techniques in identifying chronic wound infection. Concurrent swab specimens of chronic wounds were obtained using wound exudate, the Z‐technique, and the Levine technique, along with a specimen of viable wound tissue. Swab and tissue specimens were cultured using quantitative and qualitative laboratory procedures. Infected wounds were defined as those containing 1 × 106 or more organisms per gram of tissue. Accuracy was determined by associating the quantitative cultures of swab specimens with the cultures from tissue specimens using receiver operating characteristic curves. Of the 83 study wounds, 30 (36%) were infected. Accuracy was the highest for swab specimens obtained using Levines technique at 0.80. Based on Levines technique, a critical threshold of 37,000 organisms per swab provided a sensitivity of 90% and a specificity of 57%. The mean concordance between swab specimens obtained using Levines technique and tissue specimens was 78%. The findings suggest that swab specimens collected using Levines technique provide a reasonably accurate measure of wound bioburden, given that they are more widely applicable than tissue cultures. The diagnostic validity of Levines technique needs further study using an alternative reference standard, such as the development of infection‐related complications.

Clinical assessment of high-strength all-ceramic crowns ☆

STATEMENT OF PROBLEM All-ceramic crowns are being used extensively. Little data are available on their clinical performance. PURPOSE This study evaluated the clinical performance of In-Ceram (Vita Zahnfabrik) crowns. MATERIAL AND METHODS Forty-one patients (16 men, 25 women; mean age 47.3 years, range 18 to 77 years) were examined with a total of 80 In-Ceram all-ceramic crowns fabricated at the University of Iowa College of Dentistry from 1994 to 1997. The percentage distribution for crowns included: 67% anterior single crowns, 26% posterior single crowns, 6% anterior implant crowns, and 1% posterior implant crowns. This study documented the integrity of the junction between crown and tooth, color match to adjacent teeth, secondary dental caries, wear of crown and opposing dentition, and visible cracks in the crown. Alpha, Bravo, and Charlie ratings were assigned with a modified USPHS criteria. The patients were also surveyed with respect to oral hygiene and satisfaction of treatment. Estimations of 4-year success rates and corresponding confidence intervals were calculated by fitting a constant hazard function model with the SAS procedure GENMOD. RESULTS Marginal integrity for 88% of artificial crowns was rated Alpha or Bravo. Shade match for 99% was Bravo or better. Only 1% of the crowns were carious, and 1 crown exhibited occlusal wear. One premolar crown had a small fracture of veneering porcelain. One molar crown was remade after core fracture. All patients (100%) expressed satisfaction with their crowns. The estimated 4-year success rates (Alpha or Bravo), with 95% confidence intervals in parentheses were calculated as: 83.5% (65.7%-94.6%) for marginal integrity, 95.8% (82.9%-99.8%) for shade match, and 95.5% (81.6%-99.7%) for secondary caries, 100% (88%-100%) for wear, and 100% (88%-100%) for cracks.

An empirically derived taxonomy of factors affecting physicians' willingness to disclose medical errors

AbstractBACKGROUND: Physician disclosure of medical errors to institutions, patients, and colleagues is important for patient safety, patient care, and professional education. However, the variables that may facilitate or impede disclosure are diverse and lack conceptual organization. OBJECTIVE: To develop an empirically derived, comprehensive taxonomy of factors that affects voluntary disclosure of errors by physicians. DESIGN: A mixed-methods study using qualitative data collection (structured literature search and exploratory focus groups), quantitative data transformation (sorting and hierarchical cluster analysis), and validation procedures (confirmatory focus groups and expert review). RESULTS: Full-text review of 316 articles identified 91 impeding or facilitating factors affecting physicians’ willingness to disclose errors. Exploratory focus groups identified an additional 27 factors. Sorting and hierarchical cluster analysis organized factors into 8 domains. Confirmatory focus groups and expert review relocated 6 factors, removed 2 factors, and modified 4 domain names. The final taxonomy contained 4 domains of facilitating factors (responsibility to patient, responsibility to self, responsibility to profession, responsibility to community), and 4 domains of impeding factors (attitudinal barriers, uncertainties, helplessness, fears and anxieties). CONCLUSIONS: A taxonomy of facilitating and impeding factors provides a conceptual framework for a complex field of variables that affects physicians’ willingness to disclose errors to institutions, patients, and colleagues. This taxonomy can be used to guide the design of studies to measure the impact of different factors on disclosure, to assist in the design of error-reporting systems, and to inform educational interventions to promote the disclosure of errors to patients.

Digital edge-detection measurement of polyethylene wear after total hip arthroplasty.

A novel digital edge-detection computer technique was developed to measure polyethylene wear after total hip arthroplasty. The new method objectively infers the margins of the component by evaluating gradients of gray-scale intensity on digitized images of the radiographs. Compared with previous methods for measurement of wear, digital edge detection substantially reduces observer subjectivity. The technique was validated directly by measuring wear artificially produced by spherical-front milling of polyethylene liners in a benchtop series. Under such conditions, digital edge detection proved 6.4 times more accurate and 7.1 times more reproducible than manual measurement with conventional circular templates. In addition, clinical application of the new digital imaging technique was illustrated in a series of forty-three patients in whom a metal-backed acetabular cup had been inserted with cement. A random-coefficients prediction algorithm was invoked to estimate long-term wear (mean late rate of wear for the cohort, 0.087 millimeter per year at a mean of 118 months after the operation) on the basis of measurements of short-term wear (mean early rate of wear for the cohort, 0.154 millimeter per year at a mean of twenty-four months). CLINICAL RELEVANCE: Polyethylene wear is a major factor affecting the longevity of a total hip prosthesis. As ten to twenty-year results become available for a variety of bearing surfaces and designs of acetabular components, problems with acetabular wear and loosening have been substantial in too many instances. New techniques for more accurate and reproducible measurement of polyethylene wear should allow earlier detection of deleteriously increased wear and thus permit earlier identification of patients who are at risk and of potentially unacceptable constructs or designs.

Effectiveness of home telehealth in comorbid diabetes and hypertension: a randomized, controlled trial.

BACKGROUND Increased emphasis is being placed on the critical need to control hypertension (HTN) in patients with diabetes. OBJECTIVE The objective of this study was to evaluate the efficacy of a nurse-managed home telehealth intervention to improve outcomes in veterans with comorbid diabetes and HTN. DESIGN A single-center, randomized, controlled clinical trial design comparing two remote monitoring intensity levels and usual care in patients with type 2 diabetes and HTN being treated in primary care was used. MEASUREMENTS Primary outcomes were hemoglobin A1c and systolic blood pressure (SBP); secondary outcome was adherence. RESULTS Intervention subjects experienced decreased A1c during the 6-month intervention period compared with the control group, but 6 months after the intervention was withdrawn, the intervention groups were comparable with the control group. For SBP, the high-intensity subjects had a significant decrease in SBP compared with the other groups at 6 months and this pattern was maintained at 12 months. Adherence improved over time for all groups, but there were no differences among the three groups. LIMITATIONS Subjects had relatively good baseline control for A1c and SBP; minorities and women were underrepresented. CONCLUSIONS Home telehealth provides an innovative and pragmatic approach to enhance earlier detection of key clinical symptoms requiring intervention. Transmission of education and advice to the patient on an ongoing basis with close surveillance by nurses can improve clinical outcomes in patients with comorbid chronic illness.

Fractal dimension in radiographic analysis of alveolar process bone

OBJECTIVES This in vitro study examined radiographic fractal dimension changes in alveolar process bone during simulated osteoporosis. STUDY DESIGN Ten specimens of human maxillary alveolar process bone were progressively decalcified, and the percentage of calcium lost at each decalcification stage was quantified. Four radiographs of each specimen, together with an aluminum step-wedge, were exposed at 70 kVp at each stage. The test set of 560 radiographs was digitized, identical bony regions of interest were selected from the density-corrected images of each specimen, the regions were digitally filtered to reduce film-grain noise, and fractal dimension was computed on a line-to-line basis. Correlation analysis quantified the relationship between calcium loss and fractal dimension change. Analysis of variance and Duncans multiple range test determined whether a difference existed in fractal dimension computed from images at x-ray beam angulations of -5, 0, and +5 degrees. RESULTS A strong correlation (average r = -0.94, p < or = 0.0037) was found between generalized demineralization and decreasing fractal dimension. In every bone sample fractal dimension changed significantly (p < or = 0.0189) with angular change. CONCLUSIONS Radiographic fractal dimension holds promise for detecting simulated osteoporosis in the maxilla under ideal conditions, but the sensitivity of fractal dimension to small x-ray beam angular change renders its clinical application questionable.

Patient and Physician Beliefs About Control over Health: Association of Symmetrical Beliefs with Medication Regimen Adherence

BACKGROUNDPast work suggests that the degree of similarity between patient and physician attitudes may be an important predictor of patient-centered outcomes.OBJECTIVETo examine the extent to which patient and provider symmetry in health locus of control (HLOC) beliefs was associated with objectively derived medication refill adherence in patients with co-morbid diabetes mellitus (DM) and hypertension (HTN).PARTICIPANTSEighteen primary care physicians at the VA Iowa City Medical Center and affiliated clinics; 246 patients of consented providers with co-morbid DM and HTN.DESIGNEstablished patient-physician dyads were classified into three groups according to the similarity of their HLOC scores (assessed in parallel). Data analysis utilized hierarchical linear modeling (HLM) to account for clustering of patients within physicians.MAIN MEASURESObjectively derived medication refill adherence was computed using data from the VA electronic pharmacy record; blood pressure and HgA1c values were considered as secondary outcomes.KEY RESULTSPhysician-patient dyads holding highly similar beliefs regarding the degree of personal control that individual patients have over health outcomes showed significantly higher overall and cardiovascular medication regimen adherence (p = 0.03) and lower diastolic blood pressure (p = 0.02) than in dyads in which the patient held a stronger belief in their own personal control than did their treating physician. Dyads in which patients held a weaker belief in their own personal control than did their treating physician did not differ significantly from symmetrical dyads. The same pattern was observed after adjustment for age, physician sex, and physician years of practice.CONCLUSIONSThese data are the first to demonstrate the importance of attitudinal symmetry on an objective measure of medication adherence and suggest that a brief assessment of patient HLOC may be useful for tailoring the provider’s approach in the clinical encounter or for matching patients to physicians with similar attitudes towards care.