Integration of a scanning ion conductance microscope into phase contrast optics and its application to the quantification of morphological parameters of selected cells.

We have previously described a pulse-mode scanning ion conductance microscope to investigate membrane surfaces and volume changes of individual cells in culture. We have now developed a miniaturized scanning headstage that enables us to select individual cells for recording under phase contrast optics, considerably improving the selection of individual cells for scanning as well as the positioning of the scanning frames with respect to the position of the cell somata. We show an application in which surfaces and volumes of somata and processes of cultured cells from the central nervous system were quantified separately.

Implications of controlling for comorbid conditions in cost-of-illness estimates: a case study of osteoarthritis from a managed care system perspective.

OBJECTIVES: Current methods for estimating the cost of illness inconsistently control for the effect of comorbid conditions. This analysis examines the implications of controlling for comorbid conditions on the estimated cost of illness. These implications are illustrated using the cost of osteoarthritis as an example. METHODS AND DATA: Medical claims data from 1996 were obtained for inpatient, outpatient, and pharmacy services for members in four United HealthCare health plans. Total annual costs for osteoarthritis (OA) were compared to costs among an equal number of comparison members. Multivariate regression analysis was used to compare the natural log of costs between the OA and comparison groups under two alternative controls for comorbid conditions: no controls, and controls for all conditions. RESULTS: Controlling for no or all comorbid conditions resulted in estimates of the annual cost of members with OA that ranged between 261% and 151% of the cost of members without OA, respectively. CONCLUSIONS: Existing cost-of-illness estimates may seriously underestimate the true cost by including statistical controls for all comorbid conditions, or seriously overestimate the true cost by failing to control for enough comorbid conditions. In the case of OA, the range of potential bias is substantial.

Costs and resources associated with the treatment of overactive bladder using retrospective medical care claims data.

The objectives of this study were to determine age- and gender-specific drug treatment prevalence rates for overactive bladder (OAB), and to compare resource use and costs among MCO members receiving drug treatment for OAB. Administrative claims data from seven affiliated health plans were analyzed for 8,661 members with a diagnosis or treatment indicative of OAB during 1998. Resource use and associated costs were analyzed over a four-month follow-up. In 1998, the prevalence of OAB among plan members was 1.1%. Of the patients with OAB, 71% did not receive pharmacotherapy. After multivariate analysis, treatment with tolterodine, oxybutynin, or other OAB treatment did not significantly affect the percent change in total per patient per month (PPPM) costs compared with the group not receiving a pharmacologic agent. Although the adjusted percent change in PPPM pharmacy costs was significantly higher within the tolterodine group, medical and total PPPM costs were not.

One-year claims analysis comparing inhaled fluticasone propionate with zafirlukast for the treatment of asthma.

BACKGROUND: Randomized clinical trials have demonstrated that fluticasone propionate (FP) has better objective as well as subjective clinical outcomes than zafirlukast (ZA) in the treatment of asthma. OBJECTIVE: The goal of this study was to determine whether the superiority of FP over ZA observed in clinical trials is supported under actual practice conditions. METHODS: A retrospective cohort analysis of pharmacy and medical claims for asthma was performed. Patients were identified who had at least 1 ICD-9 (493.XX) claim for asthma and were recently prescribed inhaled FP or ZA. Subjects could not have had a claim for any inhaled corticosteroid or oral leukotriene modifier in the 9 months before initiation of FP or ZA. They were subsequently observed for 12 months. RESULTS: A total of 725 persons were new users of FP and 309 of ZA. FP was associated with a 70% reduced risk for hospitalization (P =.0232), a 49% lower risk for an emergency department event (P =.0546), and a 51% reduction in combined emergency department events and hospitalizations (P =.0268) when compared with ZA. Adjusted annual asthma care costs declined significantly for FP and increased for ZA. The adjusted mean difference in annual asthma costs was $215 less per patient for FP (P <.0001). CONCLUSION: Asthma care costs decreased for patients treated with FP and increased for patients treated with ZA. Furthermore, FP-treated patients had significantly lower risks of asthma-related hospitalization than ZA patients. This study supports results seen in clinical trials comparing these two medications.

A central role for the endothelial NADPH oxidase in atherosclerosis.

An increasing body of evidence has demonstrated that NADPH oxidase plays a critical role in several early steps leading toward the development of atherosclerosis. These effects appear to be carried out by both the ability of O2- to act as a small second messenger molecule, and potentially the oxidation of low density lipoprotein by O2-. We describe a model for the initiation and development of atherosclerosis that suggests targeted inhibition of NADPH oxidase as a powerful site for prevention and treatment of this disease.

Identification of a functional leukocyte-type NADPH oxidase in human endothelial cells :a potential atherogenic source of reactive oxygen species.

Cultured human endothelial cells (EC) exposed to atherogenic low-density lipoprotein levels have increased reactive oxygen species (ROS) generation. The enzyme responsible for this ROS production elevation is unknown. We have examined for the presence of a functional leukocyte-type NADPH oxidase in EC to elucidate whether this enzyme could be the ROS source. The plasma membrane fraction of disrupted EC showed a reduced-minus-oxidized difference spectra with absorption peaks identical to those observed in the spectra of the leukocyte NADPH oxidase component, cytochrome b558. Western-blot analysis, using anti-gp91 -phox. anti -p22-phox. anti -p47-phox. and anti -p67-phox antibodies, demonstrated the protein expression of NADPH oxidase subunits in EC. Reverse transcriptase-polymerase chain reaction (RT-PCR) showed the mRNA expression of gp91-phox, p22-phox, p47-phox, and p67-phox in EC. Sonicates from unstimulated EC produced no measurable superoxide; whereas, exogenously applied arachidonic acid activated superoxide generation in a manner that was dependent upon the presence of NADPH and both membrane and cytosolic fractions combined. Apocynin, a specific leukocyte NADPH oxidase inhibitor, was shown by Western-blot analysis of membrane and cytoplasmic fractions to inhibit the translocation of p47-phox to the membrane of stimulated EC. These findings support the presence of a functionally active leukocyte-type NADPH oxidase in EC. NADPH oxidase could be the major cellular ROS source in EC perturbation, which has been hypothesized to be a major contributing factor in the pathogenesis of atherosclerosis.

MRI-Based topographic parcellation of human cerebral white matter.

We describe a virtually automatic comprehensive parcellation of the human cerebral central white matter, which is based upon T1-weighted MRI scans. The system, which is "rule-based," is developed from prior anatomic studies of the human brain and experimental studies of connectivity in animals as elaborated in the companion manuscript. Boundaries which delineate anatomic subregions of the white matter are computed from the geometric features of anatomic landmarks visible in the imaging data. The fiber systems of the central white matter are ordered topographically into three compartments, reflecting the inferred arrangements of principal neural systems pathways. These include an outer radiate (fibers principally radially aligned), an intermediate sagittal (fibers principally sagittally aligned), and deep bridging (fibers bridging hemispheres or cortex and deep structures) compartments. Each of these compartments is secondarily parcellated into smaller units to increase the anatomic specificity and spatial resolution of the system. The principal intended uses for this system of anatomic subdivision are for the volumetric characterization of forebrain white matter in normal and abnormal brains and for precision and specificity of localization in focal lesion-deficit correlation studies.

MRI-Based topographic parcellation of human cerebral white matter and nuclei II. Rationale and applications with systematics of cerebral connectivity.

We describe a system for parcellation of the human cerebral white matter and nuclei, based upon magnetic resonance images. An algorithm for subdivision of the cerebral central white matter according to topographic criteria is developed in the companion manuscript. In the present paper we provide a rationale for this system of parcellation of the central white matter and we extend the system of cerebral parcellation to include principal subcortical gray structures such as the thalamus and the basal ganglia. The volumetric measures of the subcortical gray and white matter parcellation units in 20 young adult brains are computed and reported here as well. In addition, with the comprehensive system for cerebral gray and white matter structure parcellation as reference, we formulate a systematics of forebrain connectivity. The degree to which functionally specific brain areas correspond to topographically specific areas is an open empirical issue. The resolution of this issue requires the development of topographically specific anatomic analyses, such as presented in the current system, and the application of such systems to a comprehensive set of functional-anatomic correlation studies in order to establish the degree of structural-functional correspondence. This system is expected to be applied in both cognitive and clinical neuroscience as an MRI-based topographic systematics of human forebrain anatomy with normative volumetric reference and also as a system of reference for the anatomic organization of specific neural systems as disrupted by focal lesions in lesion-deficit correlations.

The clinical spectrum of post-streptococcal syndromes with arthritis in children.

Acute rheumatic fever (ARF) and post-streptococcal reactive arthritis (PSRA) are well known complications of streptococcal throat infections. We describe four children with arthritis following a streptococcal throat infection. In addition to arthritis, other clinical manifestations included erythema nodosum, livedo reticularis and cutaneous vasculitis. Because of the very diverse clinical manifestations that may appear after a streptococcal throat infection, we suggest a classification and treatment of post-streptococcal syndromes according to the severity of the disease.

Thrombin stimulated reactive oxygen species production in cultured human endothelial cells.

In order to study the major cellular source of reactive oxygen species (ROS) in perturbed human endothelial cells (EC), the effect of thrombin, a phospholipase A2 activator, on cultured EC ROS generation has been investigated. EC were incubated with 0.1-1 unit/ml thrombin and cellular superoxide anion (O(-)2) release and hydrogen peroxide (H2O2) production measured. Thrombin exposure caused an elevation in EC O(-)2 release and H2O2 production. The effects of protein kinase C, arachidonic acid metabolism, NADPH oxidase, and phospholipase A2 inhibitors on thrombin-induced EC H2O2 production were examined. EC were exposed to 0.5 unit/ml thrombin and cellular H2O2 production measured in the presence and absence of the protein kinase C inhibitor, H-7; arachidonic acid metabolism inhibitors, indomethacin, nordihydroguaiaretic acid, and SKF525A; NADPH oxidase inhibitor, apocynin; and phospholipase A2 inhibitor, 4-bromophenacyl bromide. All inhibitors, with the exception of H-7 and indomethacin, suppressed thrombin-induced EC H2O2 production. The pattern of effects of these metabolic antagonists on thrombin-induced EC ROS production is similar to that previously reported on ROS production in EC exposed to high low-density lipoprotein levels, and in stimulated leukocytes. These findings further implicate NADPH oxidase as a major ROS source in EC.

Semiautomatic segmentation of brain exterior in magnetic resonance images driven by empirical procedures and anatomical knowledge.

This work demonstrates encouraging results for increasing the automation of a practical and precise magnetic resonance brain image segmentation method. The intensity threshold for segmenting the brain exterior is determined automatically by locating the choroid plexus. This is done by finding peaks in a series of histograms taken over regions specified using anatomical knowledge. Intensity inhomogeneities are accounted for by adjusting the global intensity to match the white matter peak intensity in local regions. Automated results are incorporated into the established manually guided segmentation method by providing a trained expert with the automated threshold. The results from 20 different brain scans (over 1000 images) obtained under different conditions are presented to validate the method which was able to determine the appropriate threshold in approximately 80% of the data.

Low-density lipoprotein stimulated peroxide production and endocytosis in cultured human endothelial cells: mechanisms of action.

The effects of arachidonic acid metabolism and NADPH oxidase inhibitor on the hydrogen peroxide (H2O2) generation and endocytotic activity of cultured human endothelial cells (EC) exposed to atherogenic low-density lipoprotein (LDL) levels have been investigated. EC were incubated with 240 mg/dl LDL cholesterol and cellular H2O2 production and endocytotic activity measured in the presence and absence of the arachidonic acid metabolism inhibitors, indomethacin, nordihydroguaiaretic acid, and SKF525A, and NADPH oxidase inhibitor, apocynin. All inhibitors, with the exception of indomethacin, markedly reduced high LDL-induced increases in EC H2O2 generation and endocytotic activity. EC exposed to exogenously applied arachidonic acid had cellular functional changes similar to those induced by high LDL concentrations. EC incubated with 1-25 uM arachidonic acid had increased H2O2 production and heightened endocytotic activity. Likewise, EC pre-loaded with [3H]arachidonic acid when exposed to increasing LDL levels (90-330 mg/dl cholesterol) had a dose-dependent rise in cytosolic [3H]arachidonic acid. The phospholipase A2 inhibitors, 4-bromophenacyl bromide and 7,7-dimethyleicosadienoic acid, markedly inhibited H2O2 production in EC exposed to 240 mg/dl LDL cholesterol. These findings suggest that arachidonic acid contributes mechanistically to high LDL-perturbed EC H2O2 generation and heightened endocytosis. Such cellular functional changes add to our understanding of endothelial perturbation, which has been hypothesized to be a major contributing factor in the pathogenesis of atherosclerosis.

[Neuro-arthropathy, a painless but very destructive disorder of frequently one joint]. / Neuroartropathie, een pijnloze maar zeer destructieve aandoening van vaak slechts één gewricht.

In a 38-year-old man who suffered from recurrent painless swelling of the right knee, neuroarthropathy was diagnosed, associated with tabes dorsalis. The patient was treated with a knee brace to stabilise the joint. Neuroarthropathy is a progressive degenerative joint disease caused by a central or a peripheral neurological disorder and causing denervation of the joint.

Lifetime cost of stroke in the United States.

BACKGROUND AND PURPOSE: Stroke imposes a substantial economic burden on individuals and society. This study estimates the lifetime direct and indirect costs associated with the three major types of stroke: subarachnoid hemorrhage (SAH), intracerebral hemorrhage (ICH), and ischemic stroke (ISC). METHODS: We developed a model of the lifetime cost of incident strokes occurring in 1990. An epidemiological model of stroke incidence, survival, and recurrence was developed based on a review of the literature. Data on direct cost of treating stroke were obtained from Medicare claims data, the 1987 National Medical Expenditure Survey (NMES), and insurance claims data representing a group of large, self-insured employers. Indirect costs (the value of foregone market and nonmarket production) associated with premature morbidity and mortality were estimated based on data from the US Bureau of Economic Analysis and the 1987 NMES. RESULTS: The lifetime cost per person of first strokes occurring in 1990 is estimated to be $228,030 for SAH, $123,565 for ICH, $90,981 for ISC, and $103,576 averaged across all stroke sub-types. Indirect costs accounted for 58.0% of lifetime costs. Aggregate lifetime cost associated with an estimated 392,344 first strokes in 1990 was $40.6 billion: $5.6 billion for SAH, $6.0 billion for ICH, and $29.0 billion for ISC. Acute-care costs incurred in the 2 years following a first stroke accounted for 45.0%, long-term ambulatory care accounted for 35.0%, and nursing home costs accounted for 17.5% of aggregate lifetime costs of stroke. CONCLUSIONS: The lifetime cost of stroke varies considerably by type of stroke and entails considerable costs beyond the first 2 years after a stroke.

Centers of excellence: an assessment tool for cardiovascular and orthopedic programs.

As payers place more weight on contracting with hospital/health system programs that can differentiate themselves in the market as a "true" center of excellence (COE), it becomes imperative that hospitals/health systems understand the payer perspective about those programmatic attributes that can truly differentiate them from other programs. This report describes an evaluation and rating methodology for hospital/health system subspecialty programs, particularly cardiovascular and orthopedic programs, that can be used as a self-assessment tool. Using as its core a Rating Scale and Ranking Taxonomy, the evaluation and rating methodology presented here allow cardiovascular and orthopedic programs to do the following: Understand the differentiating characteristic of COE. Rate itself against detailed criteria that are being used by payers. Compare aspects of its program to premier or benchmark programs. Interpret the results to assist with strategic and operational direction. Allocate scarce resources to implement a subspecialty program that will attract payers. The Rating Scale and Ranking Taxonomy has 20 criteria for assessing cardiovascular programs and 18 criteria for orthopedic programs. The assessment process is designed to produce two important results: dialogue and action. The underpinnings of any action is a solid business plan that clarifies the program's vision, values, and mission. They are important because most programs will ultimately pursue very similar strategies and tactics; however, the most successful subspecialty programs and practices will be the ones that can execute the strategies and tactics quickly and effectively. In addition, the changes that are engendered by this targeted yet comprehensive assessment process can lead to improved clinical and functional outcomes for patients, as well as systemic improvements in the delivery of care.

Follow-up of treated coeliac patients: sugar absorption test and intestinal biopsies compared.

OBJECTIVE: To determine whether the sugar absorption test (SAT) during follow-up of patients with coeliac disease on a gluten-free diet (GFD) correlates with improvement of the villous architecture of the small intestine. METHODS: The SAT was performed in coeliacs at diagnosis and during follow-up with GFD. For the SAT, a solution of lactulose (L) and mannitol (M) was given to the fasting patient and the L-M ratio calculated in a 5-hour urine sample by gas chromatography: ratios > 0.089 are considered abnormal. The solution was made hyperosmolar by adding sucrose (1560 mmol/l). RESULTS: The L-M ratio was 2-3 times higher at diagnosis than either at 8 months to 2 years gluten free, or beyond 2 years gluten free, consecutively. The L-M ratio (mean, range) was significantly higher in cases of biopsies with (sub)total villous atrophy (VA) (0.388, 0.062-0.804, n = 28), partial VA (0.240, 0.062-0.841, n = 18) and villous irregularity (0.143, 0.017-0.322, n = 29) than in case of normalized histology after GFD (0.085, 0.021-0.230, n = 19). The rate of normalization of functional integrity was slower in adults than in children, demonstrated by a combination of histology and SAT. CONCLUSION: The SAT correlates well with the degree of VA. It is important for daily clinical practice that the simple and non-invasive SAT can be used as an indicator of intestinal damage, thus influencing need for and timing of intestinal biopsies.

Atherogenic levels of low-density lipoprotein increase hydrogen peroxide generation in cultured human endothelial cells: possible mechanism of heightened endocytosis.

Cultured human umbilical vein endothelial cells(EC) exposed to atherogenic low-density lipoprotein (LDL) levels have augmented reactive oxygen species generation. Confluent EC were incubated with 30-330 mg/dl LDL cholesterol and cellular hydrogen peroxide (H2O2) generation measured. EC incubated with 30 and 90 mg/dl LDL cholesterol showed similar low level H2O2 production. In contrast, EC exposed to 180 and 330 mg/dl LDL cholesterol have a marked, dose-related elevation in H2O2 generation. Subsequent studies have explored if direct EC exposure to H2O2 promotes cellular functional changes similar to those induced by high LDL levels (> 160 mg/dl cholesterol). Confluent EC were incubated with 0.1-10 mM H2O2 for 30 minutes and endocytosis measured and cytoskeletal structure examined. H2O2 exposure (0.5 and 1 mM) promoted heightened EC endocytosis, which similarly occurs with high LDL exposure. Likewise, cytoskeletal examination of EC perturbed with 1 mM H2O2 reveals structural remodeling with a marked increase in stress fibers, which similarly happens with high LDL levels. The above observations that high LDL levels cause increased EC H2O2 production, and direct H2O2 exposure promotes cellular functional changes similar to those induced by high LDL concentrations, suggest a modulatory role for reactive oxygen species. Thus LDL-induced reactive oxygen species generation may contribute mechanistically to endothelial perturbation, which has been hypothesized to be a major contributing factor in the pathogenesis of atherosclerosis.

Preparing for Medicare single-provider contracting: becoming a center of excellence.

Hospitals and physicians participating in the CABG Surgery Demonstration Project will certainly have an advantage over the competition. Although HCFA has not issued specifics of the process to be applied for the expansion of the project, a review of the program goals and events leading the initial selection is instructive.