Individual-Level and Neighborhood-Level Factors Associated with Longitudinal Changes in Cardiometabolic Measures in Participants of a Clinic-Based Care Coordination Program: A Secondary Data Analysis

Background: Identifying individual and neighborhood-level factors associated with worsening cardiometabolic risks despite clinic-based care coordination may help identify candidates for supplementary team-based care. Methods: Secondary data analysis of data from a two-year nurse-led care coordination program cohort of Medicare, Medicaid, dual-eligible adults, Leveraging Information Technology to Guide High Tech, High Touch Care (LIGHT2), from ten Midwestern primary care clinics in the U.S. Outcome Measures: Hemoglobin A1C, low-density-lipoprotein (LDL) cholesterol, and blood pressure. Multivariable generalized linear regression models assessed individual and neighborhood-level factors associated with changes in outcome measures from before to after completion of the LIGHT2 program. Results: 6378 participants had pre-and post-intervention levels reported for at least one outcome measure. In adjusted models, higher pre-intervention cardiometabolic measures were associated with worsening of all cardiometabolic measures. Women had worsening LDL-cholesterol compared with men. Women with pre-intervention HbA1c > 6.8% and systolic blood pressure > 131 mm of Hg had worse post-intervention HbA1c and systolic blood pressure compared with men. Adding individual’s neighborhood-level risks did not change effect sizes significantly. Conclusions: Increased cardiometabolic risks and gender were associated with worsening cardiometabolic outcomes. Understanding unresolved gender-specific needs and preferences of patients with increased cardiometabolic risks may aid in tailoring clinic-community-linked care planning.

An index of geospatial disadvantage predicts both obesity and unmeasured body weight

Neighborhood context impacts health. Using an index of geospatial disadvantage measures to predict neighborhood socioeconomic disparities would support area-based allocation of preventative resources, as well as the use of location as a clinical risk factor in care of individual patients. This study tested the association of the Area Deprivation Index (ADI), a neighborhood-based index of socioeconomic contextual disadvantage, with elderly obesity risk. We sampled 5066 Medicare beneficiaries at the University of Missouri between September 1, 2013 and September 1, 2014. We excluded patients with unknown street addresses, excluded body mass index (BMI) lower than 18 or higher than 62 as probable errors, and excluded patients with missing BMI data. We used a plot of simple proportions to examine the association between ADI and prevalence of obesity, defined as BMI of 30 and over. We found that obesity was significantly less prevalent in the least-disadvantaged ADI decile (decile 1) than in all other deciles (p < 0.05) except decile 7. Obesity prevalence within the other deciles (2–6 and 8–10) was not significantly distinguishable except that decile 2 was significantly lower than decile 4. Patients with missing BMI data were more likely to reside in the most disadvantaged areas. There was a positive association between neighborhood disadvantage and obesity in this Midwestern United States Medicare population. The association of missing BMI information with neighborhood disadvantage may reflect unmeasured gaps in care delivery to the most disadvantaged patients. These preliminary results support the continued study of neighborhood socioeconomic measures to identify health disparities in populations.

The Effect of Neighborhood Disadvantage on Diabetes Prevalence

Patient socioeconomic data is not usually included in medical records nor easily accessible to clinicians, yet socioeconomic disadvantage can be an important guide to disease management. This study evaluated the neighborhood-level Area Deprivation Index (ADI), a measure of neighborhood socioeconomic disadvantage, as a factor in diabetes mellitus prevalence. Electronic health records at an academic hospital system identified 4,770 Medicare beneficiaries. Logistic regression of diabetes diagnosis (ICD9=250.x) against ADI quintile, age, gender, and race/ethnicity found all these patient characteristics to be significantly associated. Diabetes prevalence was lowest in the least disadvantaged quintile of neighborhoods after adjusting for age, gender, and race/ethnicity. The positive non-linear association of diabetes prevalence with ADI demonstrates the power of this index to practically quantify socioeconomic disadvantage. The ADI may be suitable for clinical decision support, and for informing the policy changes which are needed to reduce socioeconomic disparities in diabetes prevalence and other health outcomes.

Combining Contrast Mining with Logistic Regression To Predict Healthcare Utilization in a Managed Care Population

BACKGROUND

Because 5% of patients incur 50% of healthcare expenses, population health managers need to be able to focus preventive and longitudinal care on those patients who are at highest risk of increased utilization. Predictive analytics can be used to identify these patients and to better manage their care. Data mining permits the development of models that surpass the size restrictions of traditional statistical methods and take advantage of the rich data available in the electronic health record (EHR), without limiting predictions to specific chronic conditions.

OBJECTIVE

The objective was to demonstrate the usefulness of unrestricted EHR data for predictive analytics in managed healthcare.

METHODS

In a population of 9,568 Medicare and Medicaid beneficiaries, patients in the highest 5% of charges were compared to equal numbers of patients with the lowest charges. Contrast mining was used to discover the combinations of clinical attributes frequently associated with high utilization and infrequently associated with low utilization. The attributes found in these combinations were then tested by multiple logistic regression, and the discrimination of the model was evaluated by the c-statistic.

RESULTS

Of 19,014 potential EHR patient attributes, 67 were found in combinations frequently associated with high utilization, but not with low utilization (support>20%). Eleven of these attributes were significantly associated with high utilization (p<0.05). A prediction model composed of these eleven attributes had a discrimination of 84%.

CONCLUSIONS

EHR mining reduced an unusably high number of patient attributes to a manageable set of potential healthcare utilization predictors, without conjecturing on which attributes would be useful. Treating these results as hypotheses to be tested by conventional methods yielded a highly accurate predictive model. This novel, two-step methodology can assist population health managers to focus preventive and longitudinal care on those patients who are at highest risk for increased utilization.

Identifying Patients at Risk of High Healthcare Utilization

Objective. To develop a systematic and reproducible way to identify patients at increased risk for higher healthcare costs. Methods. Medical records were analyzed for 9,581 adults who were primary care patients in the University of Missouri Health System and who were enrolled in Medicare or Medicaid. Patients were categorized into one of four risk tiers as of October 1, 2013, and the four tiers were compared on demographic characteristics, number of healthcare episodes, and healthcare charges in the year before and the year after cohort formation. Results. The mean number of healthcare episodes and the sum of healthcare charges in the year following cohort formation were higher for patients in the higher-risk tiers. Conclusions. Retrospective information that is easily extracted from medical records can be used to create risk tiers that provide highly useful information about the prospective risk of healthcare utilization and costs.

Contrast Mining for Pattern Discovery and Descriptive Analytics to Tailor Sub-Groups of Patients Using Big Data Solutions

The shift to electronic health records has created a plethora of information ready to be examined and acted upon by those in the medical and computational fields. While this allows for novel research on a scale unthinkable in the past, all discoveries still rely on some initial insight leading to a hypothesis. As the size and variety of data grows so do the number of potential findings, making it necessary to optimize hypothesis generation to increase the rate and importance of discoveries produced from the data. By using distributed Association Rule Mining and Contrast Mining in a big data ecosystem, it is possible to discover discrepancies within large, complex populations which are inaccessible using traditional methods. These discrepancies, when used as hypotheses, can help improve patient care through decision support, population health analytics, and other areas of healthcare.

The Paradox of Higher Charges for Lower-Risk Inpatient Admissions: When Healthier Patients Cost More

Risk stratification is essential to achieving the Triple Aim of better health, better care, and lower costs. Although risk tiers based on chronic disease diagnoses and recent healthcare utilization were predictive of healthcare utilization and charges in a managed population, their correlation with specific high-cost outcomes was unknown. More detailed analyses were performed to confirm that admissions for higher-risk patients were more expensive. However, these analyses found that charges for admissions of high-risk patients were actually not more expensive but 33% less expensive. The billing categories of implants, surgery, and supplies accounted for 93% of this difference. These findings may reflect that high-risk patients are less often appropriate candidates for elective surgery. An understanding of this difference, especially if validated by claims data and replicated in other populations, may lead to important insights into using risk stratification for predicting health services utilization in managed care populations.

Longitudinal Changes in Risk Stratification for a Managed Population

The LIGHT² project managed the care of approximately 10,000 Medicare (primarily elderly) and Medicaid (low income) patients between 2013 and 2015. Risk tiers based on chronic disease diagnoses and recent healthcare utilization were strongly predictive of future healthcare utilization, and the authors expected that the members of an aging and well-insured population would gradually rise in risk of healthcare utilization over the course of three years. Various analytic techniques were used to characterize the members of higher risk tiers. However, retrospective cohort analysis and simple data visualization discovered the tendency of patients in lower initial risk tiers to remain healthy, and the tendency of patients in higher initial risk tiers to improve. In a time frame of three years, this return to stability was a more important influence on healthcare utilization than risk or aging.

Secondary Use of Clinical Data to Enable Data-Driven Translational Science with Trustworthy Access Management

University of Missouri (MU) Health Care produces a large amount of digitized clinical data that can be used in clinical and translational research for cohort identification, retrospective data analysis, feasibility study, and hypothesis generation. In this article, the implementation of an integrated clinical research data repository is discussed. We developed trustworthy access-management protocol for providing access to both clinically relevant data and protected health information. As of September 2014, the database contains approximately 400,000 patients and 82 million observations; and is growing daily. The system will facilitate the secondary use of electronic health record (EHR) data at MU to promote data-driven clinical and translational research, in turn enabling better healthcare through research.

Online electronic data capture and research data repository system for clinical and translational research

Data is at the core of any clinical and translational research (CTR). In many studies, the electronic data capture (EDC) method has been found to be more efficient than standard paper-based data collection methods in many aspects, including accuracy, integrity, timeliness, and cost-effectiveness. The objective of this article is to present a secure, web-based EDC system for CTR that has been implemented by the Institute for Clinical and Translational Science (iCATS) at the University of Missouri School of Medicine.

Access to musculoskeletal specialists and resources in free and charitable clinics: a survey of clinic directors

OBJECTIVE

To evaluate the capabilities and resources of free and charitable clinics in the United States to deliver musculoskeletal care to an indigent population.

DESIGN

A voluntary, anonymous, cross-sectional survey.

SETTING

Electronic mailing list for the National Association of Free and Charitable Clinics in September 2011, and in person at the Annual Summit for the National Association of Free and Charitable Clinics in October 2011. At the time of survey, 427 member-clinics were eligible for participation.

PARTICIPANTS

One hundred forty-five (34%) respondents were included in data analysis.

INTERVENTIONS

None.

MAIN OUTCOME MEASURES

Answers to a questionnaire regarding access to musculoskeletal care.

RESULTS

The average annual clinic volume was 5690 patient visits. Low back pain was the most common orthopedic complaint. Access to musculoskeletal specialty consultants was rated as poor or worse in 83% of clinics surveyed. The majority of respondents (63%) believed that their staff was able to treat only half or fewer of the patients who presented with musculoskeletal complaints in their clinic. The resource most needed to treat these conditions was musculoskeletal physician consultants.

CONCLUSIONS

Indigent populations have a strong need for musculoskeletal care, but affordable access to physiatrists and other musculoskeletal specialists is extremely limited. Personnel at surveyed clinics believed that the greatest need to improve care is better access to these specialty physicians.

Automated region of interest analysis of dynamic Ca²+ signals in image sequences

Ca(2+) signals are commonly measured using fluorescent Ca(2+) indicators and microscopy techniques, but manual analysis of Ca(2+) measurements is time consuming and subject to bias. Automated region of interest (ROI) detection algorithms have been employed for identification of Ca(2+) signals in one-dimensional line scan images, but currently there is no process to integrate acquisition and analysis of ROIs within two-dimensional time lapse image sequences. Therefore we devised a novel algorithm for rapid ROI identification and measurement based on the analysis of best-fit ellipses assigned to signals within noise-filtered image sequences. This algorithm was implemented as a plugin for ImageJ software (National Institutes of Health, Bethesda, MD). We evaluated the ability of our algorithm to detect synthetic Gaussian signal pulses embedded in background noise. The algorithm placed ROIs very near to the center of a range of signal pulses, resulting in mean signal amplitude measurements of 99.06 ± 4.11% of true amplitude values. As a practical application, we evaluated both agonist-induced Ca(2+) responses in cultured endothelial cell monolayers, and subtle basal endothelial Ca(2+) dynamics in opened artery preparations. Our algorithm enabled comprehensive measurement of individual and localized cellular responses within cultured cell monolayers. It also accurately identified characteristic Ca(2+) transients, or Ca(2+) pulsars, within the endothelium of intact mouse mesenteric arteries and revealed the distribution of this basal Ca(2+) signal modality to be non-Gaussian with respect to amplitude, duration, and spatial spread. We propose that large-scale statistical evaluations made possible by our algorithm will lead to a more efficient and complete characterization of physiologic Ca(2+)-dependent signaling.

Dynamics of subatmospheric pressure in the pulmonary interstitial fluid

Systems analyses are presented for several aspects of pulmonary fluid dynamics, especially those related to (1) transport of fluid between the pulmonary interstitial spaces and the alveoli, (2) the possibility of a mechanism for concentrating protein in the lymph vessels, and (3) the effects of very high resistance to fluid flow in the alveolar septal wall. The analysis of fluid transport between the interstitial space and the alveoli, assuming that there is no active secretory or active absorptive process, shows that the interstitial fluid pressure in the normal lung cannot be more positive than the fluid pressure in the alveoli. Since the surface tension of this fluid causes it to have a subatmospheric pressure, the calculated maximum pressure for interstitial fluid in the normal lung is about -2 mmHg (-0.266 kPa). At any pressure more positive than this the alveoli will fill with fluid. The systems analyses for concentrating protein in the pulmonary lymphatics and for the effects of high resistance to fluid flow in the alveolar septal wall offer possible explanations for very negative pressures of pulmonary interstitial fluid, even though calculations of the interstitial fluid pressure based on the assumption that the colloid osmotic pressure of pulmonary interstitial fluid is equal to the osmotic pressure of pulmonary lymph give estimated pressures of pulmonary interstitial fluid approaching 0 mmHg.

Anti-RNA polymerase III antibodies in patients with systemic sclerosis detected by indirect immunofluorescence and ELISA

Objectives. To evaluate the analytical performance of an ELISA for the detection of anti-RNA polymerase III antibody (ARA) and to assess IIF as a method for identifying this antibody.

Methods. A commercially available ELISA was used to assess the presence of ARA in sera from 1018 SSc patients. The sera had been divided into sub-populations based on the presence of specific autoantibodies, ANA pattern or the absence of both. Patients with ARA (n = 209) had been identified by characteristic ANA pattern by IIF on HEp-2 cell substrate [and additionally by radio-immunoprecipitation (IP) in 157/209 cases]. The remaining 809 SSc patients acted as a control group.

Results. Of 157 patients in whom ARA had been confirmed by IP, 150 were positive by ELISA providing a sensitivity of 96%. In the group where ARA had only been assessed by IIF, 100% (52/52) were ELISA positive. The ANA patterns indicating the presence of ARA were a fine-speckled nucleoplasmic stain with additional occasional bright dots, with or without concurrent punctate nucleolar staining. In the SSc control group, the ELISA attained a specificity of 98%, ARA being detected in 17/809 patients.

Conclusions. We report the outcome of a study on a large population of SSc patients that shows the ARA ELISA to be of high analytical sensitivity and specificity. We confirm that there is minimal overlap between ARA and other SSc-specific autoantibodies. Additionally, it is demonstrated that the presence of ARA correlates with identifiable patterns by IIF on HEp-2 cell substrate.

Kinetics of chloral hydrate and its metabolites in male human volunteers

Chloral hydrate (CH) is a short-lived intermediate in the metabolism of trichloroethylene (TRI). TRI, CH, and two common metabolites, trichloroacetic acid (TCA) and dichloroacetic acid (DCA) have been shown to be hepatocarcinogenic in mice. To better understand the pharmacokinetics of these metabolites of TRI in humans, eight male volunteers, aged 24-39, were administered single doses of 500 or 1,500 mg or a series of three doses of 500 mg given at 48 h intervals, in three separate experiments. Blood and urine were collected over a 7-day period and CH, DCA, TCA, free trichloroethanol (f-TCE), and total trichloroethanol (T-TCE=trichloroethanol and trichloroethanol-glucuronide [TCE-G]) were measured. DCA was detected in blood and urine only in trace quantities (<2 microM). TCA, on the other hand, had the highest plasma concentration and the largest AUC of any metabolite. The TCA elimination curve displayed an unusual concentration-time profile that contained three distinct compartments within the 7-day follow-up period. Previous work in rats has shown that the complex elimination curve for TCA results largely from the enterohepatic circulation of TCE-G and its subsequent conversion to TCA. As a result TCA had a very long residence time and this, in turn, led to a substantial enhancement of peak concentrations following the third dose in the multiple dose experiment. Approximately 59% of the AUC of plasma TCA following CH administration is produced via the enterohepatic circulation of TCE-G. The AUC for f-TCE was found to be positively correlated with serum bilirubin concentrations. This effect was greatest in one subject that was found to have serum bilirubin concentrations at the upper limit of the normal range in all three experiments. The AUC of f-TCE in the plasma of this individual was consistently about twice that of the other seven subjects. The kinetics of the other metabolites of CH was not significantly modified in this individual. These data indicate that individuals with a more impaired capacity for glucuronidation may be very sensitive to the central nervous system depressant effects of high doses of CH, which are commonly attributed to plasma levels of f-TCE.

Relationship of psychiatric history to pain reports in rheumatoid arthritis

OBJECTIVE

The purpose was to examine the relationship of pre-existing psychiatric history to pain reports in a cohort of persons with RA and concomitant major depression who were receiving a trial of antidepressant medication.

METHOD

RA patients (n = 41) with a current episode of major depression were divided into two subgroups comprised of those with a previous psychiatric history (PSY+) (n = 20) and those without a previous psychiatric history (PSY-) (n = 21). The groups were compared with regard to their responsiveness to a regimen of antidepressive medication on measures of depression, pain, coping, and life stress over a period of 15 months.

RESULTS

Although depression scores for both the PSY+ and the PSY- groups decreased significantly from baseline to 15-month follow-up, the composite pain score was found to be significantly decreased only for the PSY- group.

CONCLUSION

Psychiatric history appears to predispose persons with concomitant RA and major depression to report less pain reduction following antidepressive treatment than those persons without a psychiatric history.

Effects of sub-chronic exposure to naturally occurring N-terminally truncated metabolites of glucose-dependent insulinotrophic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1), GIP(3-42) and GLP-1(9-36)amide, on insulin secretion and glucose homeostasis in ob/ob mice

Glucose-dependent insulinotrophic polypeptide (GIP) and glucagon-like peptide-1 (GLP-1) are important enteroendocrine hormones that are rapidly degraded by an ubiquitous enzyme dipeptidyl peptidase IV to yield truncated metabolites GIP(3-42) and GLP-1(9-36)amide. In this study, we investigated the effects of sub-chronic exposure to these major circulating forms of GIP and GLP-1 on blood glucose control and endocrine pancreatic function in obese diabetic (ob/ob) mice. A once daily injection of either peptide for 14 days had no effect on body weight, food intake or pancreatic insulin content or islet morphology. GLP-1(9-36)amide also had no effect on plasma glucose homeostasis or insulin secretion. Mice receiving GIP(3-42) exhibited small but significant improvements in non-fasting plasma glucose, glucose tolerance and glycaemic response to feeding. Accordingly, plasma insulin responses were unchanged suggesting that the observed enhancement of insulin sensitivity was responsible for the improvement in glycaemic control. These data indicate that sub-chronic exposure to GIP and GLP-1 metabolites does not result in physiological impairment of insulin secretion or blood glucose control. GIP(3-42) might exert an overall beneficial effect by improving insulin sensitivity through extrapancreatic action.

Adult central core disease. Clinical, histologic and genetic aspects: case report and review of the literature

Central core disease (CCD) is mainly a disease of infancy and childhood and represents a member of a group of muscular disorders known as "congenital, benign (non-progressive) myopathies". It is an uncommon disease of infancy and early childhood, and presentation is rare in adulthood. The disease is mainly familial with an autosomal-dominant pattern of inheritance, yet sporadic cases can occur. The diagnosis is based on a muscle biopsy, which documents unique morphological abnormalities of focal loss of oxidative enzyme in type I muscular fibers. The basis for this loss of such activities is represented by a near-total absence of mitochondria and sarcoplasmic reticulum in the cores. We describe a 58-year-old man diagnosed with CCD, who is one of the oldest individuals reported with CCD diagnosed by a muscle biopsy. The clinical, pathological and genetic features of this rare entity are discussed herein.

Health status, cognitive coping, and depressive symptoms: testing for a mediator effect

OBJECTIVE

Research has established a link between health status and symptoms of depression in persons with rheumatoid arthritis (RA), but the effects of "cognitive coping" variables have not been extensively studied. We examined the mediator effect of a cognitive coping variable (Pain Control and Rational Thinking factor score from the Coping Strategies Questionnaire) over the course of a pharmacological intervention.

METHOD

Data were analyzed from 54 persons with RA, all of whom met diagnostic criteria for major depression. Measures of depression, health status, and cognitive coping were collected at 4 different stages of a pharmacological (antidepressant) study as follows: (1) at baseline, (2) postintervention, (3) 6 month followup, and (4) 15 month followup.

RESULTS

Results indicated that a direct relationship existed between health status and depression at all 4 time periods. However, this relationship was mediated by cognitive coping only at the postintervention and the 6 month followup.

CONCLUSION

A cognitive coping variable was found to mediate the relationship between health status and depression, but only at moderate levels of depression.

Analyzing reliability of change in depression among persons with rheumatoid arthritis

OBJECTIVE

To examine several methods of determining reliability of change constructs in depressive symptoms in patients with rheumatoid arthritis (RA) and to demonstrate the strengths, weaknesses, and uses of each method.

METHODS

Data were analyzed from a cohort of 54 persons with RA who participated in a combined behavioral/pharmacologic intervention of 15 months duration. These longitudinal data were used to examine 3 methodologies for assessing the reliability of change for various measures of depression. The specific methodologies involved the calculations of reliable change, sensitivity to change, and reliability of the change score.

RESULTS

The analyses demonstrated differences in reliability of change performance across the various depression measures, which suggest that no single measure of depression for persons with RA should be considered superior in all contexts.

CONCLUSION

The findings highlight the value of utilizing reliability of change constructs when examining changes in depressive symptoms over time.

Acute ventilator-induced vascular permeability and cytokine responses in isolated and in situ mouse lungs

To determine the influence of experimental model and strain differences on the relationship of vascular permeability to inflammatory cytokine production after high peak inflation pressure (PIP) ventilation, we used isolated perfused mouse lung and intact mouse preparations of Balb/c and B6/129 mice ventilated at high and low PIP. Filtration coefficients in isolated lungs and bronchoalveolar lavage (BAL) albumin in intact mice increased within 20–30 min after initiation of high PIP in isolated Balb/c lungs and intact Balb/c, B6/129 wild-type, and p55 and p75 tumor necrosis factor (TNF) dual-receptor null mice. In contrast, the cytokine response was delayed and variable compared with the permeability response. In isolated Balb/c lungs ventilated with 25–27 cmH2O PIP, TNF-α, interleukin (IL)-1β, IL-1α, macrophage inflammatory protein (MIP)-2, and IL-6 concentrations in perfusate were markedly increased in perfusate at 2 and 4 h, but only MIP-2 was detectable in intact Balb/c mice using the same PIP. In intact wild-type and TNF dual-receptor null mice with ventilation at 45 cmH2O PIP, the MIP-2 and IL-6 levels in BAL were significantly increased after 2 h in both groups, but there were no differences between groups in the BAL albumin and cytokine concentrations or in lung wet-to-dry weight ratios. TNF-α was not be detected in BAL fluids in any group of intact mice. These results suggest that the alveolar hyperpermeability induced by high PIP ventilation occurs very rapidly and is initially independent of TNF-α participation and unlikely to depend on MIP-2 or IL-6.

Anxiety in rheumatoid arthritis

OBJECTIVE

To examine the level of anxiety experienced by individuals with rheumatoid arthritis (RA).

METHODS

Data from 2 previous studies were used to compare the level of anxiety (measured by the State-Trait Anxiety Inventory) in the following 4 subgroups: a general RA sample, a general osteoarthritis sample, a sample with both RA and major depression, and a normative sample of age-equivalent, working adults. Canonical correlations were used to examine associations between measures of anxiety and measures of both stress and depression. The relationship between anxiety and duration of RA was also explored.

RESULTS

The general RA sample had state anxiety levels that were comparable to the normative sample, although trait anxiety levels were significantly higher (P < 0.001). In addition, individuals with RA who also met criteria for depression exhibited significantly higher levels of both state anxiety (P < 0.0001) and trait anxiety (P < 0.0001) than was observed in the normative sample. Canonical correlations revealed that measures of anxiety were correlated with both measures of depression (r = 0.83) and measures of stress (r = 0.50). Anxiety was not found to be significantly related to RA disease duration.

CONCLUSION

These findings demonstrated that individuals with RA, especially if concomitantly depressed, tend to exhibit levels of anxiety that are generally higher than a normative group of age-equivalent, working adults. The substantial canonical correlations between anxiety and both depression and stress revealed that anxiety shares variance with these more frequently studied variables in RA. However, anxiety was not found to be related to RA disease duration.

Management of depression in rheumatoid arthritis: A combined pharmacologic and cognitive-behavioral approach

OBJECTIVE

To examine the effectiveness of cognitive-behavioral and pharmacologic treatment of depression in rheumatoid arthritis (RA).

METHODS

Subjects (n = 54) with confirmed diagnoses of both major depression and RA were randomly assigned to 1 of 3 groups: 1) cognitive-behavioral/pharmacologic group (CB-PHARM), 2) attention-control/pharmacologic group, or 3) pharmacologic control group. Measures of depression, psychosocial status, health status, pain, and disease activity were collected at baseline, posttreatment (10 weeks), 6-month followup, and 15-month followup. Data were analyzed to compare the treatment effectiveness of the groups; data also were aggregated to examine the effects of antidepressive medication over time. Lastly, a no-treatment control group was defined from a cohort of persons who declined participation.

RESULTS

Baseline comparisons on demographic and dependent measures revealed a need to assess covariates on age and education; baseline scores on dependent measures also were entered as covariates. Analyses of covariance revealed no statistically significant group differences at postintervention, 6-month followup, or 15-month followup, except higher state and trait anxiety scores for the CB-PHARM group at the 15-month followup. In the longitudinal analyses of the effects of antidepressive medication, significant improvement in psychological status and health status were found at posttreatment, 6-month followup, and 15-month followup, but no significant improvements were shown for pain or disease activity. In addition, the comparison of the aggregated pharmacologic group with a no-treatment group revealed a statistically significant benefit for the 3 groups that received the antidepressive medication.

CONCLUSION

In persons with RA, cognitive-behavioral approaches to the management of depression were not found to be additive to antidepressant medication alone, but antidepressant intervention was superior to no treatment.

Assessment of depression in rheumatoid arthritis: a modified version of the center for epidemiologic studies depression scale

OBJECTIVE

The Center for Epidemiologic Studies Depression Scale (CES-D) is an instrument commonly used to assess depressive symptoms. Although the psychometric properties of the instrument are well established, the instrument's ability to identify confirmed cases of major depression has been unclear. The purpose of this study was to evaluate the ability of cutoff scores from both a full scale and a modified CES-D to detect major depression in people with rheumatoid arthritis (RA).

METHOD

Data were analyzed from 457 persons with RA, including 91 who met criteria for major depression.

RESULTS

Results indicated that, in general, a full scale cutoff score of 19 was the most efficient in identifying cases of major depression; the cutoff score of 19 outperformed a variety of other cutoff scores from the modified scale. Even the most efficient cutoff scores, however, demonstrated problems in accurately identifying people with depression.

CONCLUSION

The CES-D, while potentially useful as a screening tool, should not be used to identify cases of major depression.

Research activities and perspectives of individuals completing a research enrichment program for physiatrists

OBJECTIVE

To investigate the research activity and perspectives, and the predictors and barriers to research activity, in a cohort of individuals completing a research enrichment program for physiatrists.

DESIGN

A retrospective cohort study design was utilized. Data collection was accomplished with a mailed survey, which was sent to 68 individuals who had completed the Research Enrichment Program for Physiatrists between 1991 and 1998. Data analysis was performed using both descriptive and inferential statistical methods.

RESULTS

Eighty-five percent (58 of 68) of surveys were completed and returned. The majority of respondents were in academic-based practice (83%) at the assistant professor level (59%). Sixty-nine percent of the group reported spending no time in research, and 64% reported having no "protected" time for research. The mean number of peer-reviewed journal publications was 2.4, and the average number of research grants was 1.6, with 57% of the cohort reporting no grant funding. Departmental PhD, statistical, and secretarial support for research were all noted to be inadequate or not available for >50% of the cohort. High demand for clinical productivity, lack of protected research time, and lack of research funding were all identified as major barriers to research activity. Cluster analysis found greater research time and support to be associated with measures of research productivity.

CONCLUSION

Long-term research success seems to require ongoing support, funding, and mentorship at the departmental and institutional level. Despite adequate training and motivation for research, research support was perceived as inadequate for many Research Enrichment Program graduates.

Vascular segmental permeabilities at high peak inflation pressure in isolated rat lungs

The response of segmental filtration coefficients (Kf) to high peak inflation pressure (PIP) injury was determined in isolated perfused rat lungs. Total (K f,t ), arterial (K f,a ), and venous (K f,v ) filtration coefficients were measured under baseline conditions and after ventilation with 40-45 cmH(2)O PIP. K f,a and K f,v were measured under zone I conditions by increasing airway pressure to 25-27 cmH(2)O. The microvascular segment K f (K f,mv ) was then calculated by: K f,mv = K f,t - K f,a - K f,v. The baseline K f,t was 0.090 +/- 0.022 ml. min(-1). cm H2O(-1). 100 g(-1) and segmentally distributed 18% arterial, 41% venous, and 41% microvascular. After high PIP injury, K f,t increased by 680%, whereas K f,a, K f,v, and K f,mv increased by 398, 589, and 975%, respectively. Pretreatment with 50 microM gadolinium chloride prevented the high PIP-induced increase in K f in all vascular segments. These data imply a lower hydraulic conductance for microvascular endothelium due to its large surface area and a gadolinium-sensitive high-PIP injury, produced in both alveolar and extra-alveolar vessel segments.

Evidence that the major degradation product of glucose-dependent insulinotropic polypeptide, GIP(3-42), is a GIP receptor antagonist in vivo

The incretin hormone glucose-dependent insulinotropic polypeptide (GIP) is rapidly degraded in the circulation by dipeptidyl peptidase IV forming the N-terminally truncated peptide GIP(3-42). The present study examined the biological activity of this abundant circulating fragment peptide to establish its possible role in GIP action. Human GIP and GIP(3-42) were synthesised by Fmoc solid-phase peptide synthesis, purified by HPLC and characterised by electrospray ionisation-mass spectrometry. In GIP receptor-transfected Chinese hamster lung fibroblasts, GIP(3-42) dose dependently inhibited GIP-stimulated (10(-7) M) cAMP production (up to 75.4+/-5.4%; P<0.001). In BRIN-BD11 cells, GIP(3-42) was significantly less potent at stimulating insulin secretion (1.9- to 3.2-fold; P<0.001), compared with native GIP and significantly inhibited GIP-stimulated (10(-7) M) insulin secretion with maximal inhibition (48.8+/-6.2%; P<0.001) observed at 10(-7) M. In (ob/ob) mice, administration of GIP(3-42) significantly inhibited GIP-stimulated insulin release (2.1-fold decrease; P<0.001) and exaggerated the glycaemic excursion (1.4-fold; P<0.001) induced by a conjoint glucose load. These data indicate that the N-terminally truncated GIP(3-42) fragment acts as a GIP receptor antagonist, moderating the insulin secreting and metabolic actions of GIP in vivo.

Improved stability, insulin-releasing activity and antidiabetic potential of two novel N-terminal analogues of gastric inhibitory polypeptide: N-acetyl-GIP and pGlu-GIP

AIMS/HYPOTHESIS

This study examined the plasma stability, biological activity and antidiabetic potential of two novel N-terminally modified analogues of gastric inhibitory polypeptide (GIP).

METHODS

Degradation studies were carried out on GIP, N-acetyl-GIP (Ac-GIP) and N-pyroglutamyl-GIP (pGlu-GIP) in vitro following incubation with either dipeptidylpeptidase IV or human plasma. Cyclic adenosine 3'5' monophosphate (cAMP) production was assessed in Chinese hamster lung fibroblast cells transfected with the human GIP receptor. Insulin-releasing ability was assessed in vitro in BRIN-BD11 cells and in obese diabetic ( ob/ ob) mice.

RESULTS

GIP was rapidly degraded by dipeptidylpeptidase IV and plasma (t(1/2) 2.3 and 6.2 h, respectively) whereas Ac-GIP and pGlu-GIP remained intact even after 24 h. Both Ac-GIP and pGlu-GIP were extremely potent ( p<0.001) at stimulating cAMP production (EC(50) values 1.9 and 2.7 nmol/l, respectively), almost a tenfold increase compared to native GIP (18.2 nmol/l). Both Ac-GIP and pGlu-GIP (10(-13)-10(-8) mmol/l) were more potent at stimulating insulin release compared to the native GIP ( p<0.001), with 1.3-fold and 1.2-fold increases observed at 10(-8) mol/l, respectively. Administration of GIP analogues (25 nmol/kg body weight, i.p.) together with glucose (18 mmol/kg) in ( ob/ ob) mice lowered ( p<0.001) individual glucose values at 60 min together with the areas under the curve for glucose compared to native GIP. This antihyperglycaemic effect was coupled to a raised ( p<0.001) and more prolonged insulin response after administration of Ac-GIP and pGlu-GIP (AUC, 644+/-54 and 576+/-51 ng.ml(-1) x min, respectively) compared with native GIP (AUC, 257+/-29 ng.ml(-1) x min).

CONCLUSION/INTERPRETATION

Ac-GIP and pGlu-GIP, show resistance to plasma dipeptidylpeptidase IV degradation, resulting in enhanced biological activity and improved antidiabetic potential in vivo, raising the possibility of their use in therapy of Type II (non-insulin-dependent) diabetes mellitus.

Clinical outcomes following a trial of sertraline in rheumatoid arthritis

We report an open-label trial of sertraline in the treatment of major depression in 54 consecutive rheumatoid arthritis (RA) patients meeting DSM-IV criteria for major depressive disorder. We initially surveyed 628 RA outpatients with the Center for Epidemiologic Studies Depression Scale (CES-D) and invited those with depression to be evaluated further and treated. Eighty-four RA patients reporting depressive symptoms agreed to participate in person, and 56 met the criteria for major depressive disorder. Of these 56 patients, 54 agreed to medication treatment and were enrolled in the study. Patients were also randomized to one of three psychological treatment conditions, but for this study, conditions were collapsed because previous research on this sample indicated no significant between-group differences in depression after treatment. Patients were assessed with the CES-D and the Hamilton Rating Scale for Depression after the intervention, at 6-month follow-up, and at 15-month follow-up. At the last follow-up, 41 patients remained for assessment. In this study, sertraline was found to be a safe and efficacious treatment of depression complicating RA.

Hepatic and renal toxicities associated with perchloroethylene

Metabolism of perchloroethylene (Perc) occurs by cytochrome P450-dependent oxidation and glutathione (GSH) conjugation. The cytochrome P450 pathway generates tri- and dichloroacetate as metabolites of Perc, and these are associated with hepatic toxicity and carcinogenicity. The GSH conjugation pathway is associated with generation of reactive metabolites selectively in the kidneys and with Perc-induced renal toxicity and carcinogenicity. Physiologically based pharmacokinetic models have been developed for Perc in rodents and in humans. We propose the addition of a submodel that incorporates the GSH conjugation pathway and the kidneys as a target organ. Long-term bioassays of Perc exposure in laboratory animals have identified liver tumors in male and female mice, kidney tumors in male rats, and mononuclear cell leukemia in male and female rats. Increases in incidence of non-Hodgkin's lymphoma and of cervical, esophageal, and urinary bladder cancer have been observed for workers exposed to Perc. Limited, and not always consistent, evidence is available concerning the kidneys as a target organ for Perc in humans. Three potential modes of action for Perc-induced liver tumorigenesis are: 1) modification of signaling pathways; 2) cytotoxicity, cell death, and reparative hyperplasia; and 3) direct DNA damage. Four potential modes of action for Perc-induced renal tumorigenesis are: 1) peroxisome proliferation, 2) alpha-2u-globulin nephropathy, 3) genotoxicity leading to somatic mutation, and 4) acute cytotoxicity and necrosis leading to cell proliferation. Finally, the epidemiological and experimental data are assessed and use of toxicity information in the development of a reference dose and a reference concentration for human Perc exposure are presented.

Complement inhibition does not reduce post-hypoxic-ischemic cerebral injury in 21-day-old rats

Hypoxic-ischemic (HI) cerebral injury frequently follows resuscitation and is a recognized cause of permanent long-term neurologic disability in children. Complement activation has been shown to participate in post-ischemic injury to a variety of tissues and organs. To test the hypothesis that complement activation participates in post-HI cerebral injury in immature rats, 21-day-old rats were subjected to right common carotid artery ligation and 8% O(2). This combination of ischemia and hypoxia resulted in the development of significant neuronal loss, edema, and atrophy in the right cerebral hemisphere. However, intraperitoneal administration of the complement inhibitors soluble complement receptor type 1 or cobra venom factor did not reduce the neuronal loss, edema, or atrophy. Therefore, complement activation did not contribute significantly to the cerebral injury observed in this immature rat model.

Renal and hepatic toxicity of trichloroethylene and its glutathione-derived metabolites in rats and mice: sex-, species-, and tissue-dependent differences

Acute cytotoxicity (lactate dehydrogenase release) of trichloroethylene (TRI), S-(1,2-dichlorovinyl)glutathione (DCVG), and S-(1,2-dichlorovinyl)-L-cysteine (DCVC) in freshly isolated renal cortical cells and hepatocytes from male and female rats was evaluated to test the hypothesis that the assay provides a valid indicator of sex- and tissue-dependent differences in sensitivity to TRI and its metabolites. We then determined mitochondrial toxicity (inhibition of state-3 and/or stimulation of state-4 respiration) in renal cortical and hepatic mitochondria from male and female rats and mice to assess sex-, tissue-, and species-dependent susceptibility. TRI was moderately cytotoxic in renal cells from male rats but was nontoxic in renal cells from female rats or hepatocytes from male or female rats. Acute cytotoxicity of both DCVG and DCVC was greater in renal cells from male rats than in renal cells from female rats. Although DCVC does not target the liver in vivo, it was a very potent hepatotoxicant in vitro. Mitochondrial toxicity in kidney and liver showed similar patterns, with mitochondria from male rats being more sensitive than mitochondria from female rats; order of potency was DCVC > DCVG >> TRI. State-3 respiration in mitochondria from mice was also inhibited, but the patterns and relative sensitivities differed from those in mitochondria from rats. Renal and hepatic mitochondria from mice were less sensitive than corresponding mitochondria from rats and renal mitochondria from female mice were significantly more sensitive than renal mitochondria from male mice. Thus, many of the species-, sex-, and tissue-dependent differences in toxicity observed in vivo are also observed in vitro.

Effects of stress management on pain behavior in rheumatoid arthritis

OBJECTIVE

To examine the effects of stress management training on pain behavior exhibited by persons with rheumatoid arthritis (RA) and the relationship of change in pain behavior with certain patient characteristics as well as change in self-reported levels of pain.

METHODS

Patients with RA (n = 131) were randomly assigned to 1 of 3 groups: a stress management group, an attention control group, or a standard care control group. The stress management and attention control groups received a 10-week intervention followed by a 15-month maintenance phase.

RESULTS

The 3 groups did not differ significantly in the change in pain behavior at any of the assessment periods. However, persons with RA who had less disease activity tended to exhibit positive changes in pain behavior over time. Changes in self-reported pain were not significantly related to changes in pain behavior.

CONCLUSION

The results indicate that stress management interventions do not reduce total pain behaviors exhibited by persons with RA. Changes in pain behaviors appear to be related to disease activity, age, and disease duration, but not to changes in self-reported measures of pain.

Carcinoma of anal-ductal origin: report of a case

A 57-year-old man who had a carcinoma proven to be of anal ductal origin is presented. Recurrent perianal fistulas were treated locally for two years until biopsy proved the malignancy. Gross and histologic examination of the specimen removed by abdominoperineal resection demonstrated the anal ductal origin of this tumor. Recurrence was seen in less than a year.

Cytochrome p450-dependent metabolism of trichloroethylene in rat kidney

The metabolism of trichloroethylene (Tri) by cytochrome P450 (P450) was studied in microsomes from liver and kidney homogenates and from isolated renal proximal tubular (PT) and distal tubular (DT) cells from male Fischer 344 rats. Chloral hydrate (CH) was the only metabolite consistently detected and was used as a measurement of P450-dependent metabolism of Tri. Pretreatment of rats with pyridine increased CH formation in both liver and kidney microsomes, whereas pretreatment of rats with clofibrate increased CH formation only in kidney microsomes. Pyridine increased CYP2E1 expression in both liver and kidney microsomes, whereas clofibrate had no effect on hepatic but increased renal CYP2E1 and CYP2C11 protein levels. These results suggest a role for CYP2E1 in both the hepatic and renal metabolism of Tri and a role for CYP2C11 in the renal metabolism of Tri. Studies with the general P450 inhibitor SKF-525A and the CYP2E1 competitive substrate chlorzoxazone provided additional support for the role of CYP2E1 in both tissues. CH formation was higher in PT cells than in DT cells and was time and reduced nicotinamide adenine dinucleotide phosphate (NADPH) dependent. However, pretreatment of rats with either pyridine or clofibrate had no effect on CYP2E1 or CYP2C11 protein levels or on CH formation in isolated cells. These data show for the first time that Tri can be metabolized to at least one of its P450 metabolites in the kidneys and quantitate the effect of P450 induction on Tri metabolism in the rat kidney.

Mood states and disease activity in patients with systemic lupus erythematosus treated with bromocriptine

We tested mood states in patients with systemic lupus erythematosus (SLE) treated with the prolactin-lowering drug, bromocriptine. Bromocriptine was given to seven patients in an open-label study to test its effects on active SLE. Two independent measures of SLE activity, the SLE Activity Measure (SLAM) and the SLE Disease Activity Index (SLEDAI), were scored and the Symptom Questionnaire (SQ) mood survey was administered at entry and at 6 monthly follow-up visits. The SLAM and SLEDAI scores improved significantly during treatment. Two of the four mood scales in the SQ (Anxiety Scale and Anger-Hostility Scale) showed significant improvement compared to the entry value at least once during treatment. Significant improvement was also observed in the Total Distress Score, which is the sum of the four scales and is a more sensitive measure of distress than the score of an individual scale. Depression, anxiety, somatic complaints, and total distress correlated positively with SLAM and/or SLEDAI scores. The Anxiety Scale and the Total Distress Score improved with treatment and did correlate positively with SLE activity. In contrast, the Anger-Hostility Scale improved with treatment but did not correlate with SLE activity.

Effects of skyrin, a receptor-selective glucagon antagonist, in rat and human hepatocytes

Peptidic glucagon antagonists have been shown to lower blood glucose levels in diabetic models (1-3), but attempts to identify small molecular weight glucagon receptor-binding antagonists have met with little success. Skyrin, a fungal bisanthroquinone, exhibits functional glucagon antagonism by uncoupling the glucagon receptor from adenylate cyclase activation in rat liver membranes (1). We have examined the effects of skyrin on cells transfected with the human glucagon receptor and on isolated rat and human hepatocytes. The skyrin used was isolated from Talaromyces wortmanni American Type Culture Collection 10517. In rat hepatocytes, skyrin (30 micromol/l) inhibited glucagon-stimulated cAMP production (53%) and glucose output (IC50 56 micromol/l). There was no detectable effect on epinephrine or glucagon-like peptide 1 (GLP-1) stimulation of these parameters, which demonstrates skyrin's selective activity. Skyrin was also evaluated in primary cultures of human hepatocytes. Unlike cell lines, which are largely unresponsive to glucagon, primary human hepatocytes exhibited glucagon-dependent cAMP production for 14 days in culture (EC50 10 nmol/l). Skyrin (10 micromol/l) markedly reduced glucagon-stimulated cAMP production (55%) and glycogenolysis (27%) in human hepatocytes. The inhibition of glucagon stimulation was a specific property displayed by skyrin and oxyskyrin but not shared by other bisanthroquinones. Skyrin is the first small molecular weight nonpeptidic agent demonstrated to interfere with the coupling of glucagon to adenylate cyclase independent of binding to the glucagon receptor. The data presented in this study indicate that functional uncoupling of the human glucagon receptor from cAMP production results in metabolic effects that could reduce hepatocyte glucose production and hence alleviate diabetic hyperglycemia.

Stress management in rheumatoid arthritis: what is the underlying mechanism?

OBJECTIVE

To test whether change in cognitive-behavioral variables (such as self-efficacy, coping strategies, and helplessness) is a mediator in the relation between cognitive behavior therapy and reduced pain and depression in persons with rheumatoid arthritis (RA).

METHODS

A sample of patients with RA who completed a stress management training program (n = 47) was compared to a standard care control group (n = 45). A path analysis testing a model including direct effects of comprehensive stress management training on pain and depression and indirect effects via change in cognitive-behavioral variables was conducted.

RESULTS

The path coefficients for the indirect effects of stress management training on pain and depression via change in cognitive-behavioral variables were statistically significant, whereas the path coefficients for the direct effects were found not to be statistically significant.

CONCLUSION

Decreases in pain and depression following stress management training are due to beneficial changes in the arenas of self-efficacy (the belief that one can perform a specific behavior or task in the future), coping strategies (an individual's confidence in his or her ability to manage pain), and helplessness (perceptions of control regarding arthritis). There is little evidence of additional direct effects of stress management training on pain and depression.

Inhibitors of myosin light chain kinase and phosphodiesterase reduce ventilator-induced lung injury

Alveolar overdistension due to high peak inflation pressures (PIP) is associated with an increased capillary filtration coefficient (K(fc)). To determine which signal pathways contribute to this injury, we perfused isolated rat lungs with 5% bovine albumin in Krebs solution and measured K(fc) after successive 30-min periods of ventilation with peak inflation pressures (PIP) of 7, 20, 30, and 35 cmH(2)O. In a high-PIP control group, K(fc) increased significantly after ventilation with 30 and 35 cmH(2)O PIP, but significant increases were prevented by treatment with 100 microM trifluoperazine, an inhibitor of Ca(2+)/calmodulin, 500 nM ML-7, an inhibitor of myosin light chain kinase (MLCK), a combination of isoproterenol (20 microM) and rolipram (10 microM) to enhance intracellular cAMP levels, and a dose of KT-5720 (2 microM), which inhibits MLCK and protein kinase C. These studies suggest that the Ca(2+)/calmodulin-MLCK pathway augments capillary fluid leak after a modest high-PIP injury and that this is attenuated by kinase inhibition and increased intracellular cAMP.

Metabolism of trichloroethylene

A major focus in the study of metabolism and disposition of trichloroethylene (TCE) is to identify metabolites that can be used reliably to assess flux through the various pathways of TCE metabolism and to identify those metabolites that are causally associated with toxic responses. Another important issue involves delineation of sex- and species-dependent differences in biotransformation pathways. Defining these differences can play an important role in the utility of laboratory animal data for understanding the pharmacokinetics and pharmacodynamics of TCE in humans. Sex-, species-, and strain-dependent differences in absorption and distribution of TCE may play some role in explaining differences in metabolism and susceptibility to toxicity from TCE exposure. The majority of differences in susceptibility, however, are likely due to sex-, species-, and strain-dependent differences in activities of the various enzymes that can metabolize TCE and its subsequent metabolites. An additional factor that plays a role in human health risk assessment for TCE is the high degree of variability in the activity of certain enzymes. TCE undergoes metabolism by two major pathways, cytochrome P450 (P450)-dependent oxidation and conjugation with glutathione (GSH). Key P450-derived metabolites of TCE that have been associated with specific target organs, such as the liver and lungs, include chloral hydrate, trichloroacetate, and dichloroacetate. Metabolites derived from the GSH conjugate of TCE, in contrast, have been associated with the kidney as a target organ. Specifically, metabolism of the cysteine conjugate of TCE by the cysteine conjugate ss-lyase generates a reactive metabolite that is nephrotoxic and may be nephrocarcinogenic. Although the P450 pathway is a higher activity and higher affinity pathway than the GSH conjugation pathway, one should not automatically conclude that the latter pathway is only important at very high doses. A synthesis of this information is then presented to assess how experimental data, from either animals or from (italic)in vitro (/italic)studies, can be extrapolated to humans for risk assessment. (italic)Key words(/italic): conjugate beta-lyase, cysteine glutathione, cytochrome P450, glutathione (italic)S(/italic)-transferases, metabolism, sex dependence, species dependence, tissue dependence, trichloroethylene.

Modes of action of trichloroethylene for kidney tumorigenesis

This article focuses on the various models for kidney toxicity due to trichloroethylene (TCE) and its glutathione-dependent metabolites, in particular S-(1,2-dichlorovinyl)-l-cysteine. Areas of controversy regarding the relative importance of metabolic pathways, species differences in toxic responses, rates of generation of reactive metabolites, and dose-dependent phenomena are highlighted. The first section briefly reviews information on the incidence and risk factors of kidney cancer in the general U.S. population. Epidemiological data on incidence of kidney cancer in male workers exposed occupationally to TCE are also summarized. This is contrasted with cancer bioassay data from laboratory animals, that highlights sex and species differences and, consequently, the difficulties in making risk assessments for humans based on animal data. The major section of the article considers proposed modes of action for TCE or its metabolites in kidney, including peroxisome proliferation, alpha(2u)-globulin nephropathy, genotoxicity, and acute and chronic toxicity mechanisms. The latter comprise oxidative stress, alterations in calcium ion homeostasis, mitochondrial dysfunction, protein alkylation, cellular repair processes, and alterations in gene expression and cell proliferation. Finally, the status of risk assessment for TCE based on the kidneys as a target organ and remaining questions and research needs are discussed.

Commentary: Human mitochondrial cytopathies

Mitochondria provide energy (ATP) for all eukaryotic cells except mature erythrocytes and keratinocytes. They are abundant in cells that expend much energy, such as muscle, exocrine pancreas, nervous system, and heart cells, and motile sperm. Many mitochondrial enzymes are encoded by nuclear DNA and imported into the mitochondria. Like bacteria, mitochondria possess their own DNA and ribosomes. They are fueled by fatty acids and pyruvate, and through acetyl-coA enzyme can use fats, carbohydrates, and proteins as energy sources, producing ATP for cells. A high index of suspicion for mitochondrial mutations enables clinicians to recognize these unusual and rare disorders and provide proper genetic counseling. Mitochondrial cytopathies include a diverse group of diseases, affecting many organs, especially skeletal muscle and central nervous system, and are associated with abnormal mitochondria in skeletal muscle known as ragged red fibers. Mitochondrial DNA mutations are detectable in peripheral blood.

Role of cytochrome P450 and glutathione S-transferase alpha in the metabolism and cytotoxicity of trichloroethylene in rat kidney

The toxicity and metabolism of trichloroethylene (TRI) were studied in renal proximal tubular (PT) and distal tubular (DT) cells from male Fischer 344 rats. TRI was slightly toxic to both PT and DT cells, and inhibition of cytochrome P450 (P450; substrate, reduced-flavoprotein:oxygen oxidoreductase [RH-hydroxylating or -epoxidizing]; EC 1.14.14.1) increased TRI toxicity only in DT cells. In untreated cells, glutathione (GSH) conjugation of TRI to form S-(1,2-dichlorovinyl)glutathione (DCVG) was detected only in PT cells. Inhibition of P450 transiently increased DCVG formation in PT cells and resulted in detection of DCVG formation in DT cells. Formation of DCVG in PT cells was described by a two-component model (apparent Vmax values of 0.65 and 0.47 nmol/min per mg protein and Km values of 2.91 and 0.46 mM). Cytosol isolated from rat renal cortical, PT, and DT cells expressed high levels of GSH S-transferase (GST; RX:glutathione R-transferase; EC 2.5.1.18) alpha (GSTalpha) but not GSTpi. Low levels of GSTmu were detected in cortical and DT cells. Purified rat GSTalpha2-2 exhibited markedly higher affinity for TRI than did GSTalpha1-1 or GSTalpha1-2, but each isoform exhibited similar VmaX values. Triethyltinbromide (TETB) (9 microM) inhibited DCVG formation by purified GSTalpha-1 and GSTalpha2-2, but not GSTalpha1-2. Bromosulfophthalein (BSP) (4 microM) only inhibited DCVG formation by GSTalpha2-2. TETB and BSP inhibited approximately 90% of DCVG formation in PT cytosol but had no effect in DT cytosol. This suggests that GSTalpha1-1 is the primary isoform in rat renal PT cells responsible for GSH conjugation of TRI. These data, for the first time, describe the metabolism of TRI by individual GST isoforms and suggest that DCVG feedback inhibits TRI metabolism by GSTs.

Role of lysophosphatidic acid and rho in glioma cell motility

We have studied the effects of the bioactive phospholipid lysophosphatidic acid (LPA) on cell lines derived from highly invasive human glioblastoma multiforme (GBM). Using transwell migration assays, we show that LPA stimulates both chemokinetic and chemotactic migration of glioma cells. Blood brain barrier breakdown and leakage of serum components that most likely include LPA are common features of GBM. Therefore, the effects of LPA on glioma cell motility are intriguing given the fact that, in vivo, GBM cells often migrate great distances from the main tumor, rendering successful therapy extremely difficult. We show here that LPA initiates a variety of signaling cascades in glioma cells. LPA-enhanced transwell migration was sensitive to pertussis toxin (PTX) treatment suggesting an important role for G(i) subtype of G proteins. LPA also stimulated Ca(2+) fluctuations and activation of extracellular signal-regulated kinases (ERKS) 1 and 2, although blocking either pathway had little effect on glioma cell migration. Exposure of glioma cells to LPA resulted in phosphorylation of the regulatory light chain (RLC) of myosin II and the formation of stress fibers and focal adhesions. These effects were blocked by Y-27632, an inhibitor of Rho-activated ROCK kinases. Time-lapse video microscopy revealed that Y-27632-treatment caused cells to assume long thin morphologies that suggested deficiencies in the contractile apparatus. Furthermore, many cells exhibited a conspicuous extension of processes when Rho/ROCK kinase cascades were inhibited. The above results suggest that LPA/Rho signaling cascades play important roles in glioma cell motility and that exposure of tumor cells to LPA in vivo may contribute to their invasive phenotype.

Implications of depression in rheumatoid arthritis: do subtypes really matter?

OBJECTIVE

To examine depressive disorders and health status in patients with rheumatoid arthritis (RA), controlling for potential confounds.

METHOD

Subjects (n = 426) completed measures of depressive symptoms (Center for Epidemiological Studies Depression Scale [CES-D]) and health status (Arthritis Impact Measurement Scales 2 [AIMS2]), via cross-sectional survey. Subjects (n = 299) with few depressive symptoms (CES-D < or = 10) were not evaluated further. Subjects with CES-D > or = 11 were interviewed using the Primary Care Evaluation of Mental Disorders to diagnose major depressive disorder (MDD; n = 46), dysthymic disorder (DD; n = 21), or minor depressive disorder (MND; n = 18).

RESULTS

Regression analyses examined differences between the depressive disorders on AIMS2 subscales. Health status scores were similar between the depressive disorder subcategories; significant differences were found between MDD and MND on AIMS2 Physical scores and MDD and DD on AIMS2 Symptom scores.

CONCLUSION

Regarding health status, presence of depression itself seems to overshadow differences between depression subtypes; antidepressant treatments/referrals for persons with concomitant RA and any depressive disorder subtype appear warranted.