Diabetes mellitus associated with lymphocytic islet inflammation in a Charolais bull.
Explore the source record for details and available documents.
Animals↗
Biomedical subjects
K Mueller
Publications and source records attributed to K Mueller.
An update on Medicare+Choice: rural Medicare beneficiaries enrolled in Medicare+Choice plans through October 2000.
Explore the source record for details and available documents.
Forecasting↗
Complications of lesser toe surgery.
Surgical procedures for lesser toe problems are among the most common surgeries done on the foot. In a shoe wearing population, the incidence of lesser toe pathologic disorders is high. The complications associated with lesser toe surgery can be troublesome for patients and physicians. Understanding the possible common complications and how to avoid them is essential to maximizing satisfactory clinical results.
Biomechanical Phenomena↗
Is electroconvulsive therapy effective for the depressed patient with comorbid borderline personality disorder?
Among the more common current indications for electroconvulsive therapy (ECT) is treatment-resistant depression. Treatment resistance is correlated with a number of factors, including the presence of comorbid personality disorders, such as borderline personality disorder (BPD). A detailed review of the literature was undertaken and very few reports or studies have dealt specifically with ECT in borderline patients. Thirteen original reports on ECT outcome in personality disordered patients were identified. Depressed patients with a personality disorder, particularly BPD, may have a poorer outcome on some measures. However, the available data suggests that depression in these patients can be effectively treated with ECT. The depressed, borderline patient appears to have two distinct disorders, one which is responsive to ECT and the other which is not. Unfortunately, the literature is limited by lack of rigorous randomized treatment studies, lack of long-term follow-up, and other methodological weaknesses. Clinical guidelines are suggested.
Borderline Personality Disorder↗
Mineral and heavy metal status as related to a mortality event and poor recruitment in a moose population in Alaska.
Moose (Alces alces) found dead (FD) and hunter-killed (HK) in 1995 on the north slope of Alaska (USA) in the Colville River Drainage were evaluated for heavy metal and mineral status. Compared to previous reports for moose and domestic cattle, and data presented here from Alaska moose outside the Colville River area, levels of Cu were determined to be low in hoof, hair, liver, kidney, rumen contents, and muscle for these north slope moose. Iron (Fe) was low in muscle as well. These findings, in conjunction with evidence of poor calf survival and adult mortality prompted investigation of a mineral deficiency in moose (serum, blood, and hair) captured in the spring of 1996 and 1997. Captured males had higher Ca, Zn and Cu levels in hair than captured females. Female moose hair samples were determined to be low (deficient) in Cu, Ca, Fe, and Se with mean levels (ppm) of 2.77, 599.7, 37.4, and 0.30, respectively. Serum Cu level was low, and to a lesser degree Zn was deficient as well. Whole blood (1997 only) was marginally deficient in Se and all animals were deficient in Cu. Based on whole blood, sera and hair, Cu levels were considered low for moose captured in spring 1996 and 1997 in the Colville River area as compared to published data and other populations evaluated in this study. Low levels of ceruloplasmin activity support this Cu deficiency theory. Evidence indicates that these moose are deficient in Cu and other minerals; however, the remote location precluded sufficient examination of animals to associate this apparent deficiency with direct effects or lesions. Renal levels of Cd increased with age at expected levels.
Alaska↗
A report on enrollment: rural Medicare beneficiaries in Medicare+Choice plans.
Explore the source record for details and available documents.
Forecasting↗
Suggested improvements in practice guidelines: market research to support clinical quality improvement.
The American College of Occupational and Environmental Medicine's Practice Guideline Dissemination Project included market research to better understand the wants and needs of physicians, case managers, and insurance adjusters who used the guidelines. We used structured and open-ended survey questions and focus groups administered to a cohort of physicians, adjusters, and case managers trained as part of the project. Respondents were generally satisfied with the format and contents of the guidelines. They requested additional material on case management and facilitation of effective treatment and return to work by other health professionals. They also suggested a variety of formats to improve the accessibility of the guidelines. The suggestions may be used in new product development or for guideline revisions.
Attitude of Health Personnel↗
Rapid 3-D cone-beam reconstruction with the simultaneous algebraic reconstruction technique (SART) using 2-D texture mapping hardware.
Algebraic reconstruction methods, such as the algebraic reconstruction technique (ART) and the related simultaneous ART (SART). reconstruct a two-dimensional (2-D) or three-dimensional (3-D) object from its X-ray projections. The algebraic methods have, in certain scenarios, many advantages over the more popular Filtered Backprojection approaches and have also recently been shown to perform well for 3-D cone-beam reconstruction. However, so far the slow speed of these iterative methods have prohibited their routine use in clinical applications. In this paper, we address this shortcoming and investigate the utility of widely available 2-D texture mapping graphics hardware for the purpose of accelerating the 3-D algebraic reconstruction. We find that this hardware allows 3-D cone-beam reconstructions to be obtained at almost interactive speeds, with speed-ups of over 50 with respect to implementations that only use general-purpose CPUs. However, we also find that the reconstruction quality is rather sensitive to the resolution of the framebuffer, and to address this critical issue we propose a scheme that extends the precision of a given framebuffer by 4 bits, using the color channels. With this extension, a 12-bit framebuffer delivers useful reconstructions for 0.5% tissue contrast, while an 8-bit framebuffer requires 4%. Since graphics hardware generates an entire image for each volume projection, it is most appropriately used with an algebraic reconstruction method that performs volume correction at that granularity as well, such as SART or SIRT. We chose SART for its faster convergence properties.
Humans↗
Losing and acquiring health insurance: consequences for health care.
Data from a sample of 5530 Nebraska adults under age 65 are used to analyze the independent correlates of four different insurance statuses: insured 12 consecutive months, uninsured 12 consecutive months, insured at the end of a 12 month period, but not throughout, and uninsured at the end of a 12 month period, but not throughout. The effects of insurance status on utilization of health care services when perceived to be needed are assessed, controlling for demographic explanations. The results show that uninsurance status, whether long-lasting or recent, indicates lower utilization than being insured. Policies designed to expand the number of persons with insurance, especially those linked to practices of insurers, are predicted to have little impact since the underlying causes of uninsurance are related to household income. Lower use of health care services among the uninsured is thought to present financial problems to providers, since the uninsured who do seek care are more likely to need more services (without paying). Problems of higher cost to treat these individuals also present problems for public policies that in effect create subsidies to expand the number of insured. Finally, this study indicates that incremental policy approaches may not deal adequately with the fundamental problems that result in increases in the number of uninsured Americans and caring for their health care needs.
Adolescent↗
Fault slip rates in the modern new madrid seismic zone
Structural and geomorphic analysis of late Holocene sediments in the Lake County region of the New Madrid seismic zone indicates that they are deformed by fault-related folding above the blind Reelfoot thrust fault. The widths of narrow kink bands exposed in trenches were used to model the Reelfoot scarp as a forelimb on a fault-bend fold; this, coupled with the age of folded sediment, yields a slip rate on the blind thrust of 6.1 +/- 0.7 mm/year for the past 2300 +/- 100 years. An alternative method used structural relief across the scarp and the estimated dip of the underlying blind thrust to calculate a slip rate of 4.8 +/- 0.2 mm/year. Geometric relations suggest that the right lateral slip rate on the New Madrid seismic zone is 1.8 to 2.0 mm/year.
Journal Article↗
Dopamine beta-hydroxylase deficiency impairs cellular immunity.
Norepinephrine, released from sympathetic neurons, and epinephrine, released from the adrenal medulla, participate in a number of physiological processes including those that facilitate adaptation to stressful conditions. The thymus, spleen, and lymph nodes are richly innervated by the sympathetic nervous system, and catecholamines are thought to modulate the immune response. However, the importance of this modulatory role in vivo remains uncertain. We addressed this question genetically by using mice that lack dopamine beta-hydroxylase (dbh-/- mice). dbh-/- mice cannot produce norepinephrine or epinephrine, but produce dopamine instead. When housed in specific pathogen-free conditions, dbh-/- mice had normal numbers of blood leukocytes, and normal T and B cell development and in vitro function. However, when challenged in vivo by infection with the intracellular pathogens Listeria monocytogenes or Mycobacterium tuberculosis, dbh-/- mice were more susceptible to infection, exhibited extreme thymic involution, and had impaired T cell function, including Th1 cytokine production. When immunized with trinitrophenyl-keyhole limpet hemocyanin, dbh-/- mice produced less Th1 cytokine-dependent-IgG2a antitrinitrophenyl antibody. These results indicate that physiological catecholamine production is not required for normal development of the immune system, but plays an important role in the modulation of T cell-mediated immunity to infection and immunization.
Animals↗
Left abomasal displacement and ulceration with perforation of abdominal musculature in two calves.
Explore the source record for details and available documents.
Abdominal Muscles↗
Anti-aliased three-dimensional cone-beam reconstruction of low-contrast objects with algebraic methods.
This paper examines the use of the algebraic reconstruction technique (ART) and related techniques to reconstruct 3-D objects from a relatively sparse set of cone-beam projections. Although ART has been widely used for cone-beam reconstruction of high-contrast objects, e.g., in computed angiography, the work presented here explores the more challenging low-contrast case which represents a little-investigated scenario for ART. Preliminary experiments indicate that for cone angles greater than 20 degrees, traditional ART produces reconstructions with strong aliasing artifacts. These artifacts are in addition to the usual off-midplane inaccuracies of cone-beam tomography with planar orbits. We find that the source of these artifacts is the nonuniform reconstruction grid sampling and correction by the cone-beam rays during the ART projection-backprojection procedure. A new method to compute the weights of the reconstruction matrix is devised, which replaces the usual constant-size interpolation filter by one whose size and amplitude is dependent on the source-voxel distance. This enables the generation of reconstructions free of cone-beam aliasing artifacts, at only little extra cost. An alternative analysis reveals that simultaneous ART (SART) also produces reconstructions without aliasing artifacts, however, at greater computational cost. Finally, we thoroughly investigate the influence of various ART parameters, such as volume initialization, relaxation coefficient lambda, correction scheme, number of iterations, and noise in the projection data on reconstruction quality. We find that ART typically requires only three iterations to render satisfactory reconstruction results.
Algorithms↗
Fast implementations of algebraic methods for three-dimensional reconstruction from cone-beam data.
The prime motivation of this work is to devise techniques that make the algebraic reconstruction technique (ART) and related methods more efficient for routine clinical use, while not compromising their accuracy. Since most of the computational effort of ART is spent for projection/backprojection operations, we first seek to optimize the projection algorithm. Existing projection algorithms are surveyed and it is found that these algorithms either lack accuracy or speed, or are not suitable for cone-beam reconstruction. We hence devise a new and more accurate extension to the splatting algorithm, a well-known voxel-driven projection method. We also describe a new three-dimensional (3-D) ray-driven projector that is considerably faster than the voxel-driven projector and, at the same time, more accurate and perfectly suited for the demands of cone beam. We then devise caching schemes for both ART and simultaneous ART (SART), which minimize the number of redundant computations for projection and backprojection and, at the same time, are very memory conscious. We find that with caching, the cost for an ART projection/backprojection operation can be reduced to the equivalent cost of 1.12 projections. We also find that SART, due to its image-based volume correction scheme, is considerably harder to accelerate with caching. Implementations of the algorithms yield run-time ratios TSART/TART between 1.5 and 1.15, depending on the amount of caching used.
Algorithms↗
Influence of sotalol on the time constant of isovolumic left ventricular relaxation in anesthetized dogs.
OBJECTIVE: To determine the effects of various doses of sotalol on myocardial relaxation in healthy dogs. ANIMALS: 12 healthy adult mixed-breed dogs anesthetized with thiopental and alpha-chloralose. PROCEDURES: Left ventricular pressure (LVP), aortic pressure, and aortic flow velocity were measured. The time constant of isovolumic relaxation (tau) was determined by means of linear regression of the natural logarithm of LVP and by means of direct measurement from the LVP-versus-time curve. Sotalol was administered IV at cumulative doses of 1, 2, 4, and 8 mg/kg to 6 dogs; the other 6 were used as controls. Mean systolic aortic pressure was used to assess afterload, and maximal rate of increase in LVP versus time (dP/dt) was used as an index of contractility. RESULTS: After administration of the first dose of sotalol, tau was increased significantly, and maximum dP/dt was decreased significantly, compared with baseline values. Administration of additional doses of sotalol did not result in any additional change in tau, but maximum dP/dt increased, and maximum dP/dt after administration of the final dose of sotalol was significantly higher than maximum dP/dt after administration of the first dose. There were no significant changes in mean systolic aortic pressure. CONCLUSIONS AND CLINICAL RELEVANCE: In healthy dogs, sotalol did not have any negative effect on myocardial relaxation beyond those attributable to its beta-blocking properties, despite an increase in intracellular ionized calcium concentration, as suggested by an increase in maximum dP/dt after an initial decrease.
Anesthesia, General↗
S-phase fraction as a predictor of prognosis in juvenile respiratory papillomatosis.
OBJECTIVE: To determine whether DNA ploidy and the S-phase fraction are predictive of the clinical course in children with recurrent respiratory papillomatosis. DESIGN: Masked compression of DNA analysis findings to the clinical course of the disease. SETTING: Tertiary referral center. PATIENTS: All pediatric patients treated for recurrent respiratory papillomatosis at our institution between 1989 and 1995 who had adequate follow-up and whose primary biopsy specimen was available for examination. Fifty-five patients met these criteria. METHODS: Information was collected from the case notes on the patient's age at presentation, sex, sites of disease, duration of active disease, and frequency of operative interventions. Flow cytometric analysis was performed on the archival paraffin-embedded primary biopsy specimen obtained at the initial surgical excision, providing DNA content and percentages of S-phase cells. The investigators who performed the DNA analysis were masked to the clinical course. RESULTS: The age of the patients at presentation ranged from 3 months to 16 years. Thirty patients had involvement in more than 1 anatomical site. The disease in 10 patients had spread to the distal tracheobronchial tree. The patients underwent a total of 1124 procedures, with a frequency range of 7 to 27 per year. All cell populations studied were diploid. The percentage of S-phase cells was significantly higher in the primary biopsy specimen from patients with disease characterized by more frequent recurrences, multiple sites, and distal extension (P<.05). In multiple regression analysis, the S-phase fraction was found to be an independent and powerful prognostic factor for aggressive disease. CONCLUSIONS: The S-phase fraction may be predictive of the clinical course in patients with juvenile respiratory papillomatosis. Prospective studies are needed to assess the diagnostic and clinical value of our primary results and to determine whether DNA analysis can assist in identifying patients at increased risk for an aggressive clinical course.
Adolescent↗
Relative affinity of CHI 621 for T-cell blasts of humans, rhesus, cynomolgus monkeys and dogs.
Explore the source record for details and available documents.
Animals↗
Locomotor stereotypy produced by dexbenzetimide and scopolamine is reduced by SKF 83566, not sulpiride.
Like amphetamine, scopolamine produces locomotor stereotypy (repetitive routes of locomotion) in an open field. To determine whether locomotor stereotypy is a common behavioral effect of anticholingeric agents, several doses of the anticholinergic dexbenzetimide were tested for the ability to produce locomotor stereotypy; like scopolamine, dexbenzetimide produced locomotor stereotypy. To investigate a possible role of dopamine in anticholinergic-induced locomotor stereotypy, we tested the ability of the dopamine D1 antagonist SKF 83566 and the D2 antagonist sulpiride to block the locomotor stereotypy induced by scopolamine as well as dexbenzetimide. SKF 83566 blocked scopolamine- and dexbenzetimide-induced locomotor stereotypy; sulpiride did not reduce dexbenzetimide-induced locomotor stereotypy, but enhanced scopolamine-induced locomotor stereotypy. Hyperlocomotion was reduced by both dopamine antagonists. Results are interpreted in support of the notion that dopamine is the likely candidate mediating locomotor stereotypy.
2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-ben↗