Predicting long-term time to cardiovascular incidents using myocardial perfusion imaging and deep convolutional neural networks

Myocardial perfusion imaging (MPI) is a clinical tool which can assess the heart's perfusion status, thereby revealing impairments in patients' cardiac function. Within the MPI modality, the acquired three-dimensional signals are typically represented as a sequence of two-dimensional grayscale tomographic images. Here, we proposed an end-to-end survival training approach for processing gray-scale MPI tomograms to generate a risk score which reflects subsequent time to cardiovascular incidents, including cardiovascular death, non-fatal myocardial infarction, and non-fatal ischemic stroke (collectively known as Major Adverse Cardiovascular Events; MACE) as well as Congestive Heart Failure (CHF). We recruited a total of 1928 patients who had undergone MPI followed by coronary interventions. Among them, 80% (n = 1540) were randomly reserved for the training and 5- fold cross-validation stage, while 20% (n = 388) were set aside for the testing stage. The end-to-end survival training can converge well in generating effective AI models via the fivefold cross-validation approach with 1540 patients. When a candidate model is evaluated using independent images, the model can stratify patients into below-median-risk (n = 194) and above-median-risk (n = 194) groups, the corresponding survival curves of the two groups have significant difference (P < 0.0001). We further stratify the above-median-risk group to the quartile 3 and 4 group (n = 97 each), and the three patient strata, referred to as the high, intermediate and low risk groups respectively, manifest statistically significant difference. Notably, the 5-year cardiovascular incident rate is less than 5% in the low-risk group (accounting for 50% of all patients), while the rate is nearly 40% in the high-risk group (accounting for 25% of all patients). Evaluation of patient subgroups revealed stronger effect size in patients with three blocked arteries (Hazard ratio [HR]: 18.377, 95% CI 3.719-90.801, p < 0.001), followed by those with two blocked vessels at HR 7.484 (95% CI 1.858-30.150; p = 0.005). Regarding stent placement, patients with a single stent displayed a HR of 4.410 (95% CI 1.399-13.904; p = 0.011). Patients with two stents show a HR of 10.699 (95% CI 2.262-50.601; p = 0.003), escalating notably to a HR of 57.446 (95% CI 1.922-1717.207; p = 0.019) for patients with three or more stents, indicating a substantial relationship between the disease severity and the predictive capability of the AI for subsequent cardiovascular inciidents. The success of the MPI AI model in stratifying patients into subgroups with distinct time-to-cardiovascular incidents demonstrated the feasibility of proposed end-to-end survival training approach.

Risk of Ischemic Bowel Disease in Patients With Atrial Fibrillation Receiving Warfarin or Non-vitamin K Antagonist Oral Anticoagulants

Background

Although atrial fibrillation (AF) is a risk factor for ischemic bowel disease, data regarding the incidence of ischemic bowel disease in patients with anticoagulated AF were limited.

Methods

The present study used the Taiwan NHIRD and included newly diagnosed patients with AF aged ≥ 20 years without ischemic bowel disease from 2012 to 2018. A total of 69,549 patients taking warfarin or non-vitamin K antagonist oral anticoagulants (NOACs) constituted the final study group. We aimed to study the incidence of ischemic bowel disease in patients with AF receiving warfarin or NOACs. Secondary endpoints were also analyzed, including ischemic stroke, systemic embolism, myocardial infarction, mortality, intracranial hemorrhage (ICH), major bleeding, and composite adverse events (ischemic bowel disease or ICH or major bleeding).

Results

There were 43,787 patients taking NOACs and 25,762 patients taking warfarin. The overall incidence rate of ischemic bowel disease was 0.036% per year and increased with the CHA2DS2-VASc scores [0.013% for patients with a CHA2DS2-VASc score of 0 (men) or 1 (women), 0.022% for those with a CHA2DS2-VASc score of 1 (men) or 2 (women), and 0.039% for those with a CHA2DS2-VASc score ≥ 2 (men) or ≥ 3 (women)]. The risk of ischemic bowel disease was similar between NOAC and warfarin groups (0.036%/year vs. 0.037%/year; adjusted hazard ratio 0.802, p = 0.430), whereas the NOAC group had a significantly lower risk of secondary endpoints compared to the warfarin group.

Conclusion

We reported the incidence of ischemic bowel disease in patients with anticoagulated AF from a nationwide cohort database and observed a positive correlation between the increase of CHA2DS2-VASc scores and the incidence rate. Moreover, NOAC was as effective as warfarin for the risk of ischemic bowel disease.

Optimal anticoagulation in elderly patients with atrial fibrillation: Which drug at which dose?

Aging is an important risk factor for adverse events in elderly patients with atrial fibrillation (AF) and complicates the management of anticoagulation. Underuse of oral anticoagulants (OACs) is common in elderly patients because of comorbidities, the altered physiological function of multiple organs, frailty, risk of falls, and the lack of randomized controlled trials (RCTs) specifically for elderly patients. Nevertheless, current data still support OACs use for reducing ischemic stroke with positive net clinical benefits. Sub-analyses of RCTs and real-world cohort studies showed that non-vitamin K antagonist OACs (NOACs) would be more favorable choices compared to warfarin for stroke prevention in the elderly. This review will discuss important data on stroke prevention and the use of NOACs in elderly AF patients.

Modified Taiwan Atrial Fibrillation Score for the Prediction of Incident Atrial Fibrillation

Background

We have proposed the Taiwan AF score consisting of age, male sex, hypertension, heart failure, coronary artery disease, end-stage renal disease, and alcoholism to predict incident atrial fibrillation (AF) in Asian population. We hypothesized that the modified Taiwan AF score (mTaiwan AF score) excluding alcoholism remained useful for predicting new onset AF.

Methods

A total of 7,220,654 subjects aged ≥ 40 years without a past history of cardiac arrhythmia were identified from a national cohort, and 438,930 incident AF occurred during a 16-year follow-up with an incidence of 0.42 per 100 person-years. The mTaiwan AF score ranging between −2 and 14 and its predictive accuracy of incident AF was analyzed.

Results

The areas under the receiver operating characteristic curve (AUCs) of the mTaiwan AF scores in predicting AF are 0.861 for 1-year follow-up, 0.829 for 5-year follow-up, 0.795 for 10-year follow-up, and 0.751 for 16-year follow-up. The risk of incident AF increased from 0.05%/year for patients with a score of −2 to 6.98%/year for those having a score of 14. Patients were classified into three groups based on the tertile values of the mTaiwan AF scores—group 1 (score −2-3), group 2 (score 4-9) and group 3 (score 10-14). The annual risks of incident AF were 0.20, 1.33, and 3.36% for group 1, 2, and 3, respectively. Compared to patients in group 1, the hazard ratios of incident AF were 5.79 [95% confidence interval (CI) 3.75-7.75] for group 2 and 8.93 (95% CI 6.47-10.80) for group 3.

Conclusions

We demonstrated that the mTaiwan AF score based on age and clinical comorbidities could be used to predict incident AF in Asian population.

Informing a PCOS Lifestyle Program: Mapping Behavior Change Techniques to Barriers and Enablers to Behavior Change Using the Theoretical Domains Framework

This article aimed to identify the behavior change techniques (BCTs) based on facilitators and barriers to lifestyle management in women with polycystic ovary syndrome (PCOS) according to the behavior change wheel (BCW). This qualitative study design using inductive thematic analysis following semistructured interviews (n = 20) identified barriers and enablers to lifestyle management. These were then mapped to Capability, Opportunity, Motivation-Behavioral Model (COM-B) constructs and the corresponding Theoretical Domains Framework (TDF) domains. This study included women with PCOS residing in Australia. Main outcome measures include intervention functions, policy categories, and BCTs described in the BCW. Twenty-three BCTs were recognized to influence behavior change in women with PCOS. Factors were categorized into the subcomponents of the COM-B: psychological capability (e.g., lack of credible information), physical capability (e.g., managing multiple health conditions), physical opportunity (e.g., limited access to resources), social opportunity (e.g., adequate social support), reflective motivation (e.g., positive health expectancies following behavior change), and automatic motivation (e.g., emotional eating). Future research should use this work to guide PCOS lifestyle intervention development and then test intervention effectiveness through an experimental phase to provide empirical evidence for wider use and implementation of tailored, theory-informed PCOS lifestyle programs as part of evidence-based PCOS management.

P252 Identifying predictors for all-cause mortality at admission, 1 and 3 years after admission for acute decompensated heart failure amongst patients with atrial fibrillation

Background

Heart failure (HF) and atrial fibrillation (AF) commonly co-exist, each, predisposing the other. AF may inflict haemodynamic disturbances, leading to reduced cardiac output and hence acute decompensation. Ultimately mortality risk is further increased. Identifying contributing factors is thus vital lest increasing risk of poor outcome.

Purpose

Identify predictors of all-cause mortality in AF patients after admission for acute decompensation HF (ADHF) at admission, 1 and 3 years. 

Methods

A retrospective observational study of 810 AF patients" first admission from 2009 to 2018, analysed using descriptive, ROC curve and Cox regression.

Results

Mortality at admission, 1 and 3 years following ADHF were 5.1%, 14.4% and 40.5% respectively. Majority of AF patients were male (64.7%) but there was no significant statistical difference between gender with associated mortality during those timelines. Using multivariate analysis, predictors associated with increased in-hospital mortality were Hyponatraemia, Na &lt; 135mmol/L (adjusted Odds Ratio, aOR 2.49; 95% Confidence Interval, CI 1.91-5.20; p0.015), Uric Acid ≥ 675 (aOR 2.75; CI 1.31-5.79; p0.008), Ejection Fraction, EF &lt; 40% (aOR 3.93; CI 1.63-9.49; p0.002). Medications on admission associated with reduced inpatient mortality were Angiotensin Converting Enzyme inhibitor (ACEi) / Angiotensin Receptor Blocker (ARB) + Beta Blocker (BB) + Mineralocorticoid Receptor Antagonist (MRA) (aOR 0.07; CI 0.02-0.30; p &lt; 0.001). At 1 year, multivariate analysis showed an associated increase in mortality when NTProBNP ≥ 7500pg/ml (adjusted Hazard Ratio, aHR 1.64; CI 1.02-2.65; p0.042) and Urea &gt; 7mmol/L (aHR 1.86; CI 1.04-3.32, p0.036). Medications on discharge comprising ACEi/ARB + BB + MRA were the only combination that showed a reduction in mortality (aHR 0.23; CI 0.09-0.60; p0.003). At 3 years, background coronary artery disease (aHR 1.72; CI 1.09-2.71; p0.02), hypernatraemia, Na &gt; 145mmol/L (aHR 14.89; CI 3.17-69.86; p0.001), EF &lt; 40% (aHR 2.00; CI 1.28-3.12; p0.002) were associated with increased mortality. Medications on discharge namely ACEi/ARB (aHR 0.14; CI 0.03-0.70; p0.013), BB (aHR 0.23; CI 0.10-0.51; p &lt; 0.001), ACEi/ARB + BB (aHR 0.16; CI0.06-0.41; p &lt; 0.001), ACEi/ARB + MRA (aHR 0.34; CI 0.14-0.85; p0.021), BB + MRA (aHR 0.38; CI 0.17-0.83; p0.016), ACEi/ARB + BB + MRA (aHR 0.193; CI 0.09-0.43; p &lt; 0.001) showed an associated reduction in mortality.

Conclusions

In this single centre study, patients with AF who presented with ADHF had a variety of mortality predictors that influence at different timelines. They had higher risk of inpatient mortality with hyponatraemia, hyperuricaemia and EF &lt; 40%. Elevated NTProBNP and Urea levels seemed to have more effect on mortality at 1 year compared to 3 years. Having 3 disease-modifying heart failure medications at discharge exerted the most benefit up to 3 years of follow up.

Abstract P252 Figure.

Metabolic syndrome in polycystic ovary syndrome: a systematic review, meta-analysis and meta-regression

Women with polycystic ovary syndrome (PCOS) have increased risk of metabolic syndrome. The relative contribution of clinical, demographic or biochemical factors to metabolic syndrome in PCOS is not known. A literature search was conducted in MEDLINE, CINAHL, EMBASE and clinical trial registries. Of 4530 studies reviewed, 59 were included in the systematic review and 27 in the meta-analysis and meta-regression. In good and fair quality studies, women with PCOS had an overall increased prevalence of metabolic syndrome (odds ratio, OR 3.35, 95% confidence interval, CI 2.44, 4.59). Increased prevalence of metabolic syndrome occurred in overweight or obese women with PCOS (OR 1.88, 95% 1.16, 3.04) but not in lean women (OR 1.45, 95% CI 0.35, 6.12). In meta-regression analyses, the markers of metabolic syndrome diagnostic criteria (waist circumference, high-density lipoprotein cholesterol, triglyceride, blood pressure), BMI, glucose tolerance (2-hr oral glucose tolerance test) and surrogate markers of insulin resistance (HOMA-IR) but not markers of reproductive dysfunction (sex hormone binding globulin, testosterone, PCOS phenotypes) contributed significantly to the heterogeneity in the prevalence of metabolic syndrome. Women with PCOS have increased risk of metabolic syndrome which was associated with obesity and metabolic features but not with indices of hyperandrogenism.

Large falcine meningioma presented as treatment-resistant depression: A case report

Large intracranial tumour may present only with psychiatric symptoms without any neurological deficits. Delay in surgical treatment may significantly affect the quality of life in these patients. We report a case of a young engineering student who was diagnosed as treatment-resistant depression without initial neuroimaging study. Further neuroimaging studies revealed he has a large falcine meningioma. His psychiatric symptoms resolved following surgical resection of the tumour. We emphasized the importance of initial neuroimaging study in young patients presenting with psychiatric symptoms.

Differences in the diagnosis and management of systemic lupus erythematosus by primary care and specialist providers in the American Indian/Alaska Native population

Objectives The objective of this study is to investigate differences in the diagnosis and management of systemic lupus erythematosus (SLE) by primary care and specialist physicians in a population-based registry. Methods This study includes individuals from the 2009 Indian Health Service lupus registry population with a diagnosis of SLE documented by either a primary care provider or specialist. SLE classification criteria, laboratory testing, and medication use at any time during the course of disease were determined by medical record abstraction. Results Of the 320 individuals with a diagnosis of SLE, 249 had the diagnosis documented by a specialist, with 71 documented by primary care. Individuals with a specialist diagnosis of SLE were more likely to have medical record documentation of meeting criteria for SLE by all criteria sets (American College of Rheumatology, 79% vs 22%; Boston Weighted, 82% vs 32%; and Systemic Lupus International Collaborating Clinics, 83% vs 35%; p < 0.001 for all comparisons). In addition, specialist diagnosis was associated with documentation of ever having been tested for anti-double-stranded DNA antibody and complement 3 and complement 4 ( p < 0.001). Documentation of ever receiving hydroxychloroquine was also more common with specialist diagnosis (86% vs 64%, p < 0.001). Conclusions Within the population studied, specialist diagnosis of SLE was associated with a higher likelihood of having SLE classification criteria documented, being tested for biomarkers of disease, and ever receiving treatment with hydroxychloroquine. These data support efforts both to increase specialist access for patients with suspected SLE and to provide lupus education to primary care providers.

Anti-C1q antibodies in systemic lupus erythematosus

OBJECTIVE

Anti-C1q has been associated with systemic lupus erythematosus (SLE) and lupus nephritis in previous studies. We studied anti-C1q specificity for SLE (vs rheumatic disease controls) and the association with SLE manifestations in an international multicenter study.

METHODS

Information and blood samples were obtained in a cross-sectional study from patients with SLE (n = 308) and other rheumatologic diseases (n = 389) from 25 clinical sites (84% female, 68% Caucasian, 17% African descent, 8% Asian, 7% other). IgG anti-C1q against the collagen-like region was measured by ELISA.

RESULTS

Prevalence of anti-C1q was 28% (86/308) in patients with SLE and 13% (49/389) in controls (OR = 2.7, 95% CI: 1.8-4, p < 0.001). Anti-C1q was associated with proteinuria (OR = 3.0, 95% CI: 1.7-5.1, p < 0.001), red cell casts (OR = 2.6, 95% CI: 1.2-5.4, p = 0.015), anti-dsDNA (OR = 3.4, 95% CI: 1.9-6.1, p < 0.001) and anti-Smith (OR = 2.8, 95% CI: 1.5-5.0, p = 0.01). Anti-C1q was independently associated with renal involvement after adjustment for demographics, ANA, anti-dsDNA and low complement (OR = 2.3, 95% CI: 1.3-4.2, p < 0.01). Simultaneously positive anti-C1q, anti-dsDNA and low complement was strongly associated with renal involvement (OR = 14.9, 95% CI: 5.8-38.4, p < 0.01).

CONCLUSIONS

Anti-C1q was more common in patients with SLE and those of Asian race/ethnicity. We confirmed a significant association of anti-C1q with renal involvement, independent of demographics and other serologies. Anti-C1q in combination with anti-dsDNA and low complement was the strongest serological association with renal involvement. These data support the usefulness of anti-C1q in SLE, especially in lupus nephritis.

Validity of a self-administered version of the brief index of lupus damage in a predominantly African American systemic lupus erythematosus cohort

OBJECTIVE

To assess the reliability and criterion and construct validity of the self-administered Brief Index of Lupus Damage (SA-BILD), a patient-reported measure of organ damage in systemic lupus erythematosus (SLE).

METHODS

The validity of the SA-BILD was assessed using data from the Georgians Organized Against Lupus (GOAL) survey. GOAL is a longitudinal cohort of SLE patients predominantly derived from the Georgia Lupus Registry, a population-based registry established in Atlanta, Georgia. In total, 711 participants with documented SLE completed the SA-BILD. To test reliability, the SA-BILD was readministered to 32 patients. Criterion validity was examined in 150 respondents for whom the Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index (SDI) was also completed. Construct validity was assessed among 711 GOAL participants by dividing the SA-BILD scores into quartiles and examining the association with demographics, health status, and health care utilization.

RESULTS

The test-retest correlation score was 0.93 (P < 0.0001), the item-by-item agreement with the SDI was >80% for most SA-BILD items, and the Spearman's rho correlation coefficient for the SDI and SA-BILD was moderately high (ρ = 0.59, P < 0.0001). SA-BILD scores showed significant associations in the expected directions with age, disease duration, disease activity, overall health, comorbidity index, and physician visits.

CONCLUSION

The SA-BILD was reliable and had very good or good criterion validity compared with the SDI when tested in a predominantly African American cohort of US SLE patients. Associations of SA-BILD scores with sociodemographics and health status were consistent with previous studies. These findings support the use of the SA-BILD as a valid measure of patient-reported damage in SLE.

The effect of obesity on polycystic ovary syndrome: a systematic review and meta-analysis

While many women with polycystic ovary syndrome (PCOS) are overweight, obese or centrally obese, the effect of excess weight on the outcomes of PCOS is inconsistent. The review aimed to assess the effects of overweight, obesity and central obesity on the reproductive, metabolic and psychological features of PCOS. MEDLINE, EMBASE, CINAHL, Cochrane Central Register of Controlled Trials (CENTRAL) and PSYCINFO were searched for studies reporting outcomes according to body mass index categories or body fat distribution. Data were presented as mean difference or risk ratio (95% confidence interval). This review included 30 eligible studies. Overweight or obese women with PCOS had decreased sex hormone-binding globulin (SHBG), increased total testosterone, free androgen index, hirsutism, fasting glucose, fasting insulin, homeostatic model assessment-insulin resistance index and worsened lipid profile. Obesity significantly worsened all metabolic and reproductive outcomes measured except for hirsutism when compared to normal weight women with PCOS. Overweight women had no differences in total testosterone, hirsutism, total-cholesterol and low-density lipoprotein-cholesterol compared to normal weight women and no differences in SHBG and total testosterone compared to obese women. Central obesity was associated with higher fasting insulin levels. These results suggest that prevention and treatment of obesity is important for the management of PCOS.

Benefits of a self-management program in low-income African-American women with systemic lupus erythematosus: results of a pilot test

Minorities with systemic lupus erythematosus (SLE) are at high risk of poor disease outcomes and may face challenges in effectively self-managing multiple health problems. The Chronic Disease Self-Management Program (CDSMP) is an evidence-based intervention that improves the health of people with chronic illnesses. Although the CDSMP is offered by organizations throughout the United States and many countries around the world, it has not been tested among SLE patients. We pilot tested the benefits of the CDSMP in low-income African American patients with SLE. CDSMP workshops were delivered to 49 African American women with SLE who received medical care at a public lupus clinic in Atlanta, Georgia, US. We compared pre-post CDSMP changes (from baseline to 4 months after the start of the intervention) in health status, self-efficacy and self-management behaviors using self-reported measures. Additionally, we assessed health care utilization changes using electronic administrative records in the 6-month periods before and after the intervention. We observed significant improvements post-intervention in the SF-36 physical health component summary (mean change = 2.4, p = 0.032); self-efficacy (mean change = 0.5, p = 0.035); and several self-management behaviors: cognitive symptoms management (mean change = 0.3, p = 0.036); communication with physicians (mean change = 0.4, p = 0.01); and treatment adherence (mean change = 0.4, p = 0.01). The median number of outpatient visits decreased from 3 to 1 (p < .0001). The CDSMP is a promising intervention for low-income African Americans with SLE. It is an inexpensive program with growing availability around the world that should be further evaluated as a resource to improve patient-centered outcomes and decrease health service utilization among SLE patients.

Overweight, obesity and central obesity in women with polycystic ovary syndrome: a systematic review and meta-analysis

BACKGROUND Polycystic ovary syndrome (PCOS) is closely associated with obesity but the prevalence of obesity varies between published studies. The objective of this research was to describe the prevalence of overweight, obesity and central obesity in women with and without PCOS and to assess the confounding effect of ethnicity, geographic regions and the diagnostic criteria of PCOS on the prevalence. METHODS MEDLINE, EMBASE, CINAHL, Cochrane Central Register of Controlled Trials (CENTRAL) and PSYCINFO were searched for studies reporting the prevalence of overweight, obesity or central obesity in women with and without PCOS. Data were presented as prevalence (%) and risk ratio (RR) [95% confidence interval (CI)]. Random-effect models were used to calculate pooled RR. RESULTS This systematic review included 106 studies while the meta-analysis included 35 studies (15129 women). Women with PCOS had increased prevalence of overweight [RR (95% CI): 1.95 (1.52, 2.50)], obesity [2.77 (1.88, 4.10)] and central obesity [1.73 (1.31, 2.30)] compared with women without PCOS. The Caucasian women with PCOS had a greater increase in obesity prevalence than the Asian women with PCOS compared with women without PCOS [10.79 (5.36, 21.70) versus 2.31 (1.33, 4.00), P < 0.001 between subgroups). CONCLUSIONS Women with PCOS had a greater risk of overweight, obesity and central obesity. Although our findings support a positive association between obesity and PCOS, our conclusions are limited by the significant heterogeneity between studies and further studies are now required to determine the source of this heterogeneity. Clinical management of PCOS should include the prevention and management of overweight and obesity.

Developmental immunolocalization of heat shock protein 70 (HSP70) in epithelial cell of rat kidney

During renal development the cells in the medulla are exposed to elevated and variable interstitial osmolality. Heat shock protein 70 (HSP70) is a major molecular chaperone and plays an important role in the protection of cells in the renal medulla from high osmolality. The purpose of this study was to establish the time of immunolocalization and distribution of HSP70 in developing and adult rat kidney. In addition, changes in HSP70 immunolocalization following the infusion of furosemide were investigated. In adult animals, the HSP70 was expressed in the medullary thin ascending limb of Henle's loop (ATL) and inner medullary collecting duct (IMCD). In developing kidney, HSP70 immunoreactivity was first detected in the IMCD of the papillary tip on postnatal day 1. From four to 14 days of age, HSP70 was detected in the ATL after transformation from thick ascending limb, beginning at the papillary tip and ascending to the border between the outer and inner medulla. The immunolocalization of HSP70 in both the ATL and IMCD gradually increased during two weeks. The gradual increase in HSP70 was associated with an increase in its mRNA abundance. However, furosemide infusion resulted in significantly reduced HSP70 immunolocalization in the IMCD and ATL. These data demonstrated that the expression of HSP70 was closely correlated with changes in interstitial osmolality during the development of the kidney. We suggest that HSP70 protects ATL and IMCD cells in the inner medulla from the stress of high osmolality and may be involved in the transformation of the ATL of the long loop of Henle during renal development.

Fabrication and characterization of graphene hydrogel via hydrothermal approach as a scaffold for preliminary study of cell growth

BACKGROUND

Three-dimensional assembly of graphene hydrogel is rapidly attracting the interest of researchers because of its wide range of applications in energy storage, electronics, electrochemistry, and waste water treatment. Information on the use of graphene hydrogel for biological purposes is lacking, so we conducted a preliminary study to determine the suitability of graphene hydrogel as a substrate for cell growth, which could potentially be used as building blocks for biomolecules and tissue engineering applications.

METHODS

A three-dimensional structure of graphene hydrogel was prepared via a simple hydrothermal method using two-dimensional large-area graphene oxide nanosheets as a precursor.

RESULTS

The concentration and lateral size of the graphene oxide nanosheets influenced the structure of the hydrogel. With larger-area graphene oxide nanosheets, the graphene hydrogel could be formed at a lower concentration. X-ray diffraction patterns revealed that the oxide functional groups on the graphene oxide nanosheets were reduced after hydrothermal treatment. The three-dimensional graphene hydrogel matrix was used as a scaffold for proliferation of a MG63 cell line.

CONCLUSION

Guided filopodia protrusions of MG63 on the hydrogel were observed on the third day of cell culture, demonstrating compatibility of the graphene hydrogel structure for bioapplications.

The effect of comprehensive lifestyle intervention or metformin on obesity in young women

BACKGROUND AND AIM

Young women are at high risk of weight gain but few weight management interventions have been investigated in this group. This study aimed to determine the effect of metformin on body weight, body composition, metabolic risk factors and reproductive hormone levels in overweight or obese young women compared to placebo and comprehensive lifestyle intervention.

METHODS AND RESULTS

203 overweight or obese young women (BMI 33.2+/-0.3 kg/m², age 28+/-0.3 years) were randomised to 1500 mg/day metformin (M) plus general lifestyle advice, placebo (P) plus general lifestyle advice or comprehensive lifestyle intervention including structured diet, exercise and behavioural therapy (L) for 12-weeks. At 12-weeks, linear mixed models found that L group had greater weight loss (-4.2+/-0.4 kg) compared to M (-1.0+/-0.4 kg) and P groups (-0.2+/-0.3 kg) (P < 0.0001). Weight loss between M and P groups were not significantly different. Attrition rate was 48% for L, 34% for M and 29% for P (P = 0.08). Intention-to-treat analysis showed that 10% (8/79) of the subjects in P group had gained weight (>3%), compared to 3% (2/65) from M group and none (0/59) from L group (P < 0.001). The L group had the greatest decrease in waist circumference (-5.2+/-0.7 cm) and fat mass (-5.4+/-0.7 kg) compared to the other groups (P < 0.05). No significant time-by-group effects were seen in plasma lipids, SHBG, testosterone, blood pressure, serum folate, serum ferritin and serum vitamin B12.

CONCLUSION

Lifestyle intervention was more effective in reducing body weight and improving body composition compared to metformin among healthy overweight or obese young women.

Long-term effects of a low carbohydrate, low fat or high unsaturated fat diet compared to a no-intervention control

BACKGROUND AND AIM

Very low carbohydrate ad libitum diets have been shown to enhance weight loss without increasing cardiometabolic risk factors but no kilojoule-controlled trials have been conducted relative to no intervention. The aim of this study was to compare the changes in weight and other cardiovascular risk factors in 3 isocaloric energy-restricted diets to no-intervention control after 1 year.

METHODS AND RESULTS

One hundred and thirteen subjects (age 47 ± 10 years, BMI 32 ± 6 kg/m(2) with one additional cardiovascular risk factor) were randomly allocated to one of three isocaloric diets (VLC-very low carbohydrate, 60% fat, 4% carbohydrate, n=30; VLF-very low fat, 10% fat, n = 30; HUF-high unsaturated fat, 30% fat, n = 30) with intensive support for 3 months followed by minimal support for 12 months compared to a control group (no intervention, n = 23). The estimated weight change was -3.0 ± 0.2 kg for VLC, -2.0 ± 0.1 kg for VLF, -3.7 ± 0.01 kg for HUF and 0.8 ± 0.5 kg for controls (P=0.065). After correcting for baseline values, decreases in body weight and diastolic blood pressure in the diet groups (-2.9 ± 5.2) were significantly different to the increase in the control group (0.8 ± 5.0) (P<0.05). No differences in cardiovascular risk factors were observed between the diet groups.

CONCLUSION

Significant cardiometabolic risk factor reduction was observed equally with VLC, VLF and HUF diets after 15 months, compared to an exacerbation of risk factors in the control group. At a modest level of adherence, 3 months of intensive support on these dietary patterns confer an improvement in cardiometabolic profile compared to no dietary intervention after 15 months.

Roasted licorice extracts dampen high glucose-induced mesangial hyperplasia and matrix deposition through blocking Akt activation and TGF-beta signaling

Diabetic nephropathy (DN) characterized as nephrotic syndrome and diffuse glomerulosclerosis can cause renal failure and end-stage kidney disease. Expansion of mesangial matrix around capillaries in the kidney glomeruli is a prominent feature of DN. This study investigated whether licorice extracts inhibited mesangial cell (MC) proliferation and matrix accumulation induced by high glucose (HG). Human renal MC were cultured in media containing 5.5 mM glucose plus 27.5 mM mannitol as an osmotic control or 33 mM glucose for 3 d in the presence of water or ethanol extracts from raw licorice (LW, LE) or roasted licorice (RLW, RLE). Non-polar components including glycyrrhetic acid were elevated during licorice roasting, whereas polar components soluble in water extracts were diminished. Exposure of cells to HG caused significant increases in collagen IV secretion and connective tissue growth factor (CTGF) expression, which was appeased by RLW and RLE at transcriptional levels. The inhibitory potency was high in the order of RLE > or = RLW > or = LE > > LW. Non-polar glycyrrhetic acid but not glycyrrhizin retarded HG-stimulated mesangial matrix deposition through diminishing CTGF expression. In addition, RLW and RLE but not LW modulated membrane type matrix metalloproteinase-1 (MT-1 MMP) expression, MMP-2 activity and tissue inhibitor of MMP-2 (TIMP-2), which facilitated the degradation of mesangial matrix. Furthermore, the augmented expression of CTGF and TIMP-2 in HG-exposed cells was mediated by Akt activation and TGF-beta/Smad signaling through PKCbeta2-responsive signaling pathways. However, HG-down-regulated MT-1 MMP expression was independent of activation of ERK1/2 and Akt when using their inhibitors of DB98059 (ERK1/2) and LY294002 (Akt) alone or in combination. These results demonstrate that extracts from roasted licorice may be highly potent therapeutic agents for the prevention and treatment of mesangial fibrosis and glomerulosclerosis leading to diabetes nephropathy due to longstanding diabetes mellitus.

VIPoma syndrome: challenges in management

Vasoactive intestinal peptide-producing tumour (VIPoma) or Verner-Morrison syndrome is a very rare neuroendocrine tumour. It occurs in less than ten percent of all pancreatic islet cell tumours, and about 70 percent to 80 percent of these tumours originate from the pancreas. Diagnosis is characteristically delayed. The first-line treatment is surgical. It may be curative in forty percent of patients with benign and non-metastatic disease. Palliative surgery is indicated in extensive disease, followed by conventional somatostatin analogue (octreotide) therapy. Somatostatin analogues improve hormone-mediated symptoms, reduce tumour bulk and prevent local and systemic effects. We present a female patient with VIPoma syndrome, which had metastasised to the liver at diagnosis. The patient underwent palliative Whipple procedure and subsequent cytoreductive radiofrequency ablations to her liver metastases. Unfortunately, after symptomatic improvement for three years, her disease progressed. Currently, she is on daily octreotide, achieving partial control of her symptoms.

Assessing the cost-effectiveness of drug and lifestyle intervention following opportunistic screening for pre-diabetes in primary care

AIMS/HYPOTHESIS

This study aims to evaluate the cost-effectiveness of a screening programme for pre-diabetes, which was followed up by treatment with pharmaceutical interventions (acarbose, metformin, orlistat) or lifestyle interventions (diet, exercise, diet and exercise) in order to prevent or slow the onset of diabetes in those at high risk.

METHODS

To approximate the experience of individuals with pre-diabetes in the Australian population, we used a microsimulation approach, following patient progression through diabetes, cardiovascular disease and renal failure. The model compares costs and disability-adjusted life years lived in people identified through an opportunistic screening programme for each intervention compared with a 'do nothing' scenario, which is representative of current practice. It is assumed that the effect of a lifestyle change will decay by 10% per year, while the effect of a pharmaceutical intervention remains constant throughout use.

RESULTS

The most cost-effective intervention options are diet and exercise combined, with a cost-effectiveness ratio of AUD 22,500 per disability-adjusted life year (DALY) averted, and metformin with a cost-effectiveness ratio of AUD 21,500 per DALY averted. The incremental addition of one intervention to the other is not cost-effective.

CONCLUSIONS/INTERPRETATION

Screening for pre-diabetes followed by diet and exercise, or metformin treatment is cost-effective and should be considered for incorporation into current practice. The number of dietitians and exercise physiologists needed to deliver such lifestyle change interventions will need to be increased to appropriately support the intervention.

Synthesis of flavonoids and their effects on aldose reductase and sorbitol accumulation in streptozotocin-induced diabetic rat tissues

Aldose reductase, the key enzyme of the polyol pathway, and oxidative stress are known to play important roles in the complications of diabetes. A drug with potent inhibition of aldose reductase and oxidative stress, therefore, would be a most promising drug for the prevention of diabetic complications. The purpose of this study was to develop new compounds with these dual-effects through synthesis of chalcone derivatives and by examining the structure-activity relationships on the inhibition of rat lens aldose reductase as well as on antioxidant effects. A series of 35 flavonoid derivatives were synthesized by Winget's condensation, oxidation, and reduction of appropriate acetophenones with appropriate benzaldehydes. The inhibitory activity of these derivatives on rat lens aldose reductase and their antioxidant effects, measured using Cu2+ chelation and radical scavenging activities on 1,1-diphenyl-picrylhydrazyl in-vitro, were evaluated. Their effect on sorbitol accumulation in the red blood cells, lenses and sciatic nerves of streptozotocin-induced diabetic rats was also estimated. Among the new flavonoid derivatives synthesized, those with the 2′,4′-dihydroxyl groups in the A ring such as 2,4,2′,4′-tetrahydroxychalcone (22), 2,2′,4′-trihydroxychalcone (11), 2′,4′-dihydroxy-2,4-dimethylchalcone (21) and 3,4,2′,4′-tetrahydroxychalcone (18) were found to possess the highest rat lens aldose reductase inhibitory activity in-vitro, their IC50 values (concentration of inhibitors giving 50% inhibition of enzyme activity) being 1.6 times 10−7, 3.8 times 10−7, 4.0 times 10−7 and 4.6 times 10−7 M, respectively. All of the chalcones tested except 3, 18, 23 with o-dihydroxy or hydroquinone moiety showed a weak free radical scavenging activity. In the in-vivo experiments, however, compound 18 with o-dihydroxy moiety in the B ring showed the strongest inhibitory activity in the accumulation of sorbitol in the tissues. It also showed the strongest activity in transition metal chelation and free radical scavenging activity. Of the 35 4,2′-dihydroxyl and 2′,4′-dihydroxyl derivatives of flavonoid synthesized, including chalcone, flavone, flavanone, flavonol and dihydrochalcone, some chalcone derivatives synthesized were found to possess aldose reductase inhibition and antioxidant activities in-vitro as well as inhibition in the accumulation of sorbitol in the tissues in-vivo. 3,4,2′,4′-Tetrahydroxychalcone (18, butein) was the most promising compound for the prevention or treatment of diabetic complications.

QF-PCR-based prenatal detection of aneuploidy in a southeast Asian population

OBJECTIVES

We have investigated the efficacy of using quantitative fluorescent polymerase chain reaction (QF-PCR) for the prenatal recognition of aneuploidy in chromosomes 13, 18, 21, X and Y. A total of 1115 samples, from mainly southeast Asian patients, were analysed and compared in a blind trial to the results previously obtained cytogenetically.

METHODS

A multiplex PCR involving 15 short tandem repeat (STR) sequences was used. The probability of two or more of these markers being informative was calculated, and this required the multiplex PCR to be modified.

RESULTS

The QF-PCR and previous cytogenetic results concurred, except for two products of conception (POC). One of these may be a case of complete uniparental disomy that was not recognized cytogenetically. The other was tetraploid, and as such appeared normal using QF-PCR. A mosaic trisomy 18 was correctly identified. The population sample was of a mainly Chinese, ethnic origin, and the allele frequency, size and heterozygosity appeared more restricted than the population groups analysed hitherto.

CONCLUSION

The QF-PCR methodology is an efficient cost-effective method of screening for major chromosome aneuploidy, and, for certain referral categories, could be used alone. It also appears to be applicable to patients of different ethnic origins.

The use of low-dose prednisone in the management of rheumatoid arthritis

Low doses of prednisone are safe and effective in the management of RA. Yet, some clinicians continue to manage their RA patients with glucocorticoid doses that are too high or avoid them altogether. Glucocorticoids in low doses have proven to be very effective in suppressing the inflammation associated with RA. In addition, there is good evidence that low doses of prednisolone retard bony erosions of RA. Potential side effects of low doses of glucocorticoids can be anticipated and avoided with prudent preventative measures and appropriate management. Therefore, prednisone should be initiated as early as possible in the treatment of RA usually with another DMARD. Treatment of the inflammation in RA should not exceed 10 mg/day and often may need to be given in daily divided doses (5 mg BID). Supplemental daily calcium at 800-1,000 mg/day and vitamin D at 400-800 units/day should always be initiated with treatment. Tapering of prednisone should be done slowly using 1 mg decrements every couple weeks to a month. One should not deem it a failure to hold the patient on the lowest effective dose of prednisone.

Cost-effectiveness of prescribing statins according to pharmaceutical benefits scheme criteria

OBJECTIVES

(i) To analyse how well Pharmaceutical Benefits Scheme (PBS) criteria for prescribing lipid-lowering therapy identify people most at risk of coronary heart disease (CHD); and (ii) to determine the cost-effectiveness of primary prevention therapy with pravastatin according to these criteria in Australia.

DESIGN

(i) Analysis of targeting of CHD risk according to PBS criteria; (ii) cost-effectiveness analysis for pravastatin as primary preventive therapy (40 mg/day), with a 20-year projection from 1999.

PARTICIPANTS

(i) Men and women aged 25-69 years from the 1989 National Heart Foundation Risk Factor Prevalence Survey; (ii) Australian men and women, aged 25-85 years, excluding those with diabetes and existing CHD.

MAIN OUTCOME MEASURES

(i) Proportion eligible for lipid lowering treatment according to PBS criteria within 15-year risk of CHD mortality groups; (ii) average net cost in Australian dollars ($) per year of life saved (YOLS), with 80% uncertainty ranges (UR).

RESULTS

(i) PBS criteria do not adequately identify those most at risk of CHD, as only 61% of Australians (aged 25-69 years) with a greater than 10% 15-year risk of CHD mortality were eligible for treatment; and 11% of those at low risk of CHD mortality (< 2.5% over 15 years) were eligible for treatment. (ii) Cost-effectiveness of treatment according to PBS criteria was estimated at $110,000 (80% UR, $96,000-$150,000) per YOLS for men and $87,000 (80% UR, $80,000-$130,000) per YOLS for women. As an indicator of the likely recurrent annual costs, total first-year treatment costs (excluding the costs of non-compliers) were estimated at $940 million. Assuming compliance of 50%, cost-effectiveness of treatment was markedly improved using 32.5% 15-year risk of CHD mortality as a cut-off, with ratios of $31,000 (80% UR, $27,000-$40,000) per YOLS for men and $39,000 (80% UR, $33,000-$53,000) per YOLS for women. First-year treatment costs of $940 million were the same as treating according to PBS criteria, but absolute health impact in terms of deaths averted and years of life saved was more than doubled.

CONCLUSIONS

While PBS criteria do target patients at risk of CHD, there is room for improvement in identifying those most at risk of CHD, and treatment according to PBS criteria is not likely to be the most cost-effective. For optimal cost-effectiveness, targeting of therapy for primary CHD prevention needs to be based on population-specific, multivariable risk.

Inhibition of prostalglandin E2 production by 2'-hydoxychalcone derivatives and the mechanism of action

The effects of 14 synthetic 2'-hydroxychalcone derivatives on prostaglandin E2 (PGE2) production in rat peritoneal macrophages stimulated by the protein kinase C activator, 12-O-tetradecanoylphorbol 13-acetate (TPA), were examined to clarify the structure-activity relationship. 2',4-Dihydroxy-4'-methoxychalcone (compound 3), 2',4-dihydroxy-6'-methoxychalcone (compound 8) and 2'-hydroxy-4'-methoxychalcone (compound 9) suppressed PGE2 production more potently than the other compounds. The IC50 (50% Inhibitory concentration) value for compounds 3, 8 and 9 was calculated to be 3 microM. The activity of cyclooxygenase (COX)-1 was inhibited slightly by compound 9, but that of COX-2 was not inhibited. At concentrations that inhibited the production of PGE2, compound 9 had no effect on the release of radioactivity from [3H]arachidonic acid-labelled macrophages stimulated by TPA. Western-blot analysis revealed that the induction of COX-2 protein by TPA was inhibited by compound 9 in parallel with the inhibition of PGE2 production. Compounds 3 and 8 had similar effects. These findings suggest that 4'-methoxyl and 6'-methoxyl groups are required for the expression of more potent inhibitory activity against PGE2 production, and that the inhibition of PGE2 production by these 2'-hydroxychalcone derivatives is due to the inhibition of TPA-induced COX-2 protein expression.

Inhibition of prostaglandin E2 production by platycodin D isolated from the root of Platycodon grandiflorum

Platycodin D, isolated from the root of Platycodon grandiflorum A. DC. (Campanulaceae) suppressed prostaglandin E2 production at 10 and 30 microM in rat peritoneal macrophages stimulated by the protein kinase C activator 12-O-tetradecanoylphorbol 13-acetate (TPA). Platycodin D3 and oleanolic acid showed no effect at these concentrations. Western blot analysis revealed that the induction of COX-2 protein by TPA was inhibited by platycodin D in parallel with the inhibition of prostaglandin E2 production. Platycodin D showed no direct effect on COX-1 and COX-2 activities. TPA-induced release of [3H]arachidonic acid from pre-labeled macrophages was also not inhibited by platycodin D.

Cost-effectiveness of screening x-rays at admission to acute rehabilitation after joint replacement surgery: a retrospective chart review

OBJECTIVE

To investigate the cost-effectiveness of performing routine screening x-rays for patients on admission to an acute rehabilitation facility, after hip or knee replacement surgery, by reviewing the overall incidence of abnormal radiographic findings and determining their impact on patient care and outcome.

DESIGN

A retrospective chart review study, in which 592 patients were admitted, after hip or knee replacement surgery, to three acute inpatient rehabilitation facilities under one system.

RESULTS

Eight of 592 admissions revealed abnormal screening x-rays, for an overall incidence of 1.35%. All of the eight abnormal radiologic cases remained medically stable throughout their acute rehabilitation stay. The abnormalities did not alter the patients' medical management or length of stay. One case, which had demonstrated normal admission films, revealed a dislocated hip prosthesis on a follow-up x-ray, which was obtained as a result of new onset hip pain. The patient was subsequently transferred back to the acute care hospital for surgical correction.

CONCLUSIONS

The authors found a relatively low incidence of abnormal admission x-ray findings; furthermore, the detection of abnormal admission films did not alter patient care or outcome. The results suggested that performing routine admission radiologic studies on all patients after joint replacement surgery or hemiarthroplasty may not be a cost-effective screening tool in rehabilitation.

Antioxidant and immunostimulating activities of the fruiting bodies of Paecilomyces japonica, a new type of Cordyceps sp

Cordyceps is negative for its many biological activities and a tonic for restoring vital functions in traditional Chinese medicine. In an effort to evaluate the pharmacological effects, including the antiaging effect of the fruiting bodies of the cultivated Paecilomyces japonica fungus, a new type of Cordyceps sp. was investigated. This investigation was focused on ultimately revealing its biologically active principles, its effects on free-radical scavenging enzymes, lipid peroxidation, as well as its immunological functions. As a result, both water and methanol extracts were found to cause not only significant increases in rat liver cytosolic SOD, catalase, and GSEH-px activities, but also a significant decrease in MDA production in TBA reactant assay in rats. The extracts also showed immunostimulating activity as measured by carbon clearance, weight-loaded forced swimming performances, and immobilizing stress in mice. Using bioassay-guided systematic fractionation of the extracts, two pure compounds were isolated as active principles from low molecular-weight fraction, a protein-bound polysaccharide was isolated that showed a marked increase in the liver enzyme activities, as well as a significant inhibition of lipid peroxidation.

An unusual case of groin discomfort

Groin complications after cardiac catheterizations are common. With the increasing use of mechanical hemostatic devices, cardiologists must be alert to a wide array of potential problems. We report an unusual complication after the use of a closure device.

Inhibitory effects of 2'-hydroxychalcones on rat lens aldose reductase and rat platelet aggregation

Inhibitory effects of synthetic 2'-hydroxychalcone derivatives on rat lens aldose reductase (RLAR) and on platelet aggregation were investigated for the prevention or the treatment of chronic diabetic complications. 5'-chloro-4,2'-dihydroxychalcone (8) and 5'-chloro-3,2'-dihydroxychalcone (27) exhibited a potent inhibitory effect on rat platelet aggregation induced by ADP (IC50=0.10 and 0.06 mg/ml, respectively) and collagen (IC50=44 and 16 microg/ml, respectively) but showed relatively weak inhibitory activities on RLAR.

Fimbrin in podosomes of monocyte-derived osteoclasts

Fimbrin, an actin-bundling protein, is a component of the osteoclast adhesion complexes called podosomes. In this study, we (1) determined the localization of fimbrin in the mature rabbit osteoclast as well as in differentiating osteoclasts using the avian monocyte-derived osteoclast differentiation model, (2) characterized the distribution and accumulation of three fimbrin isotypes (T, L, and I) in avian monocytes as they fused to form multinucleate osteoclast-like cells, and (3) report for the first time, a close spatial relationship between podosomes and microtubules using fimbrin as a marker of the podosome. Immunofluorescence using anti-T-fimbrin, anti-L-fimbrin, and pan-isotype-anti-fimbrin antibodies, showed that fimbrin is an integral component of the podosome core in the mature rabbit osteoclast and in the monocyte-derived osteoclast throughout differentiation. Anti-I-fimbrin, however, did not show immunoreactivity in these cultures. These studies also show that in the avian model of monocyte-derived osteoclast differentiation, day 2 cells (D2) are predominantly mononucleate and have few podosomes. By days 4 and 6 in culture (D4 and D6), many cells have fused and punctate rows of podosomes are commonly observed at cell margins. Analysis by Western blot of protein accumulation showed that after an initial small rise from D2 to D4, L-fimbrin levels remained relatively constant from D4 to D6. However, T-fimbrin protein levels increase steadily from D2 to D6, suggesting that it may be related to the increase in podosome formation as monocytes fuse to form osteoclasts. Finally, we examined the distribution of podosomes relative to other cytoskeletal elements such as microtubules and intermediate filaments. Double immunofluorescence labeling using anti-fimbrin and anti-tubulin showed podosomes lying adjacent to microtubules at cell margins. When osteoclasts were treated with nocodazole (1 X 10(-6) M) to disrupt microtubules, the distribution of podosomes became more random and was no longer confined to the cell periphery. These results suggest that microtubule-podosome interactions may play a role in osteoclast adhesion.

Characterization of a novel filament system in goldfish xanthophores

We report the presence of a novel filament system in goldfish xanthophores using a monoclonal antibody (A2) made against 40-70 kD proteins derived from cytoskeletal preparations. On Western blots, this antibody recognized a 45 kD protein in xanthophore cell extracts. In cells with dispersed pigment, immunofluorescence staining of xanthophores revealed a uniform distribution of A2-reactive filaments. In cells with aggregated pigment, these filaments assumed a distinctively radial orientation, such that filaments emanated from the central pigment mass (CPM). At the electron microscopic level, immunogold labeling identified a filament system with a diameter of 7 nm. Overall, the cellular distribution of A2-reactive filaments was distinctly different from that of the other known components of the cytoskeleton, such as intermediate filaments, actin filaments, and microtubules. A2-reactive filaments also appeared resistant to agents known to perturb the cytoskeleton such as cytochalasin B, which depolymerized the actin filaments. When xanthophores were treated with vinblastine, shown to depolymerize microtubules and induce the collapse of intermediate filaments (vimentin and keratin) in other cell types, no effect on the A2 filament distribution was observed. On the other hand, treatment with calyculin A, a phosphatase inhibitor, converted A2 filaments into a wavy bundles, the effect of which was completely reversible by the removal of the drug from culture medium. These novel properties of A2 filaments, together with their reorganization in response to pigment translocation suggest that A2 filaments might play a yet unidentified role in intracellular organelle transport in these cells.

Synthesis and anti-inflammatory and analgesic activities of pyridyloxy- and phenoxyalkanoic acid derivatives

Synthesis of pyridyloxy-, pyridyloxyphenoxy- and phenoxylphenoxyalkanate derivatives and their anti-inflammatory and analgesic activities were investigated. Analysis of structure-activity relationships showed that in pyridyloxyalkanoic acid derivatives anti-edematous potency was associated with the presence of chlorophenoxypropionic acid moiety and 2-nitrated methyl propionates contributed to the analgesic activity.

Inhibition by tectorigenin and tectoridin of prostaglandin E2 production and cyclooxygenase-2 induction in rat peritoneal macrophages

Tectorigenin and tectoridin, isolated from the rhizomes of Korean Belamcanda chinensis (Iridaceae) which are used as Chinese traditional medicine for the treatment of inflammation, suppressed prostaglandin E2 production by rat peritoneal macrophages stimulated by the protein kinase C activator, 12-O-tetradecanoylphorbol 13-acetate (TPA), or the endomembrane Ca2+-ATPase inhibitor, thapsigargin. Tectorigenin inhibited prostaglandin E2 production more potently than tectoridin. Neither compound inhibited the release of radioactivity from [3H]arachidonic acid-labeled macrophages stimulated by TPA or thapsigargin. In addition, activities of isolated cyclooxygenase (COX)-1 and COX-2 were not inhibited by the two compounds. Western blot analysis revealed that the induction of COX-2 by TPA or thapsigargin was inhibited by the two compounds in parallel with the inhibition of prostaglandin E2 production. These findings suggest that one of the mechanisms of the anti-inflammatory activities of the rhizomes of Belamcanda chinensis is the inhibition of prostaglandin E2 production by tectorigenin and tectoridin due to the inhibition of the induction of COX-2 in the inflammatory cells.

Osteocyte shape is dependent on actin filaments and osteocyte processes are unique actin-rich projections

Osteocytes are derived from a select group of osteoblasts that have undergone a final differentiation. Due to their inaccessibility when embedded in the bone matrix, very little is known about the osteocyte cytoskeleton. This study provides an extensive analysis of the osteocyte cytoskeleton, based on the successful isolation of osteocytes from 16-day embryonic chick calvariae. We used OB7.3, a chicken osteocyte-specific monoclonal antibody, to confirm the osteocytic phenotype of the isolated cells and established culture conditions to promote growth of cells that most resemble osteocytes in vivo. Immunofluorescence staining with antitubulin, antivimentin, and antiactin showed the relative distribution of the microtubules, intermediate filaments, and actin filaments in both osteocyte cell body and processes. Field emission scanning electron microscopy revealed the three-dimensional relationships of the cytoskeletal elements and a unique organization of actin bundles that spanned the cell body and osteocyte processes. When combined with drug studies, these experiments demonstrate that actin filaments are crucial for the maintenance of osteocyte shape. Furthermore, we identified two actin-bundling proteins, alpha-actinin and fimbrin, in osteocyte processes. The prominence and unique distribution of fimbrin in osteocyte processes provides the possibility of its use as an intracellular marker to distinguish osteocytes from osteoblasts.

A diet rich in fat and poor in dietary fiber increases the in vitro formation of reactive oxygen species in human feces

Production of reactive oxygen species in the lumen of the colon, a process that is influenced by nutritional factors, may be important in the etiology of colorectal cancer. Because research on humans in support of this hypothesis is lacking, the objective of this study was to measure the effect of different dietary compositions on the in vitro oxygen radical production in human feces. Over a period of 12 d, seven healthy subjects received a diet rich in fat (50%) and meat and poor in dietary fiber. After a period of 1 wk, they received a vegetarian diet poor in fat (20%) and rich in dietary fiber. At the end of each study period, feces were collected and analyzed for in vitro oxygen radical production with dimethylsulfoxide as the free radical scavenger. The mean hydroxyl radical production was 13 times greater in feces of subjects when they consumed the diet rich in fat and poor in dietary fiber [52.7 +/- 29.5 micromol/(g feces x h)] than when they consumed the diet poor in fat and rich in dietary fiber [3.9 +/- 3.9 micromol/(g feces x h); P < 0.05]. This difference was associated with a 42% higher fecal iron concentration when they consumed the first diet (7.0 +/- 19.2 micromol/g feces) than when they consumed the second (4.9 +/- 1.9 micromol/g feces; P < 0.05). The results of this study confirm that diets high in fat and meat and low in fiber markedly increase the potential for hydroxyl radical formation in the feces, which in turn may contribute to an enhanced risk of colorectal cancer.

Glycogen biogenesis in rat 1 fibroblasts expressing rabbit muscle glycogenin

Glycogenin, a self-glucosylating protein involved in the initiation of glycogen biosynthesis, varies in intracellular concentration from barely detectable in liver to a high level in muscle. The effect of increasing the glycogenin level on glycogen synthesis was studied in rat 1 fibroblasts stably overexpressing rabbit muscle glycogenin. In the presence of glucose, all of the expressed glycogenin was attached to polysaccharide and the free protein could only be detected by western blot analysis after incubation of cells in a glucose-depleted medium or treatment of the cell extract with alpha-amylase. In control cells, increased extracellular glucose concentrations promoted translocation of glycogen synthase from the soluble to the pellet fraction with an increase in the associated glycogen. Overexpression of glycogenin did not affect total intracellular glycogen and glycogen synthase levels at any concentration of glucose but significantly reduced glucose-induced accumulation of insoluble glycogen and translocation of glycogen synthase. Immunofluorescence analysis revealed a diffuse cytoplasmic distribution of glycogenin expressed in rat 1 cells. In rat 1 cells incubated with glucose, discrete deposits of glycogen were detected by staining with HIO4/Schiff but this was eliminated by overexpressing glycogenin. Analysis of [14C]glucose- or [35S]methionine-labeled extracts from glycogenin-expressing cells by continuous polyacrylamide gel electrophoresis and by two-dimensional gel electrophoresis revealed a continuum of glycogenin-containing species from low molecular mass to sizes significantly greater than 400 kDa. We conclude that (a) overexpression of glycogenin does not enhance glycogen synthesis but causes production of more, smaller, glycogen molecules with a concomitant change in their intracellular localization; (b) glycogenin and elevated glucose have opposing effects on the distribution of glycogenin and glycogen synthase in rat 1 cells; and (c) the biogenesis of glycogen in rat 1 cells occurs without the accumulation of any major intermediate form.

Immunodetection of alpha-actinin in focal adhesions is limited by antibody inaccessibility

In this study we demonstrate that alpha-actinin is a prominent component of the focal adhesions of nonmuscle cells but that the alpha-actinin in focal adhesions is largely inaccessible to staining with antibodies against alpha-actinin. Our results explain a controversy that has existed in the literature. Investigators who microinject alpha-actinin into nonmuscle cells have routinely observed significant incorporation of alpha-actinin into focal adhesions as well as stress fibers. Immunofluorescence and immunoelectron microscopy have, however, indicated that alpha-actinin is located farther from the membrane than either talin or vinculin. Immunofluorescence studies of smooth muscle dense plaques and myotendinous junctions have also yielded conflicting results regarding the presence or absence of alpha-actinin at these sites. Here, we confirm that alpha-actinin immunofluorescence of fibroblasts yields weak or absent staining of focal adhesions. We also demonstrate that microinjected alpha-actinin readily incorporates into focal adhesions. However, various antisera against either the cell's endogenous alpha-actinin or against the microinjected chicken gizzard alpha-actinin fail to stain focal adhesions despite the presence of microinjected alpha-actinin at these sites. Furthermore, disassembly of stress fibers induced by dibutyrl cAMP demonstrates that alpha-actinin persists in focal adhesions in the absence of associated stress fibers, suggesting that alpha-actinin's association with focal adhesions is independent of stress fibers.

Differentiation dependent expression of tensin and cortactin in chicken osteoclasts

The expression and localization of tensin and cortactin were examined in osteoclast precursors in comparison with isolated osteoclasts on various substrates. Initially, the ability of hen monocytes to differentiate into osteoclasts was evaluated on plastic or glass, and compared to differentiation on bone. Specifically, monocytes were isolated from the medullary bones of egg-laying hens maintained on a Ca-deficient diet. Differentiation was monitored morphologically and by quantitation of the ability to form Howship's lacunae in bone slices or resorb radiolabeled bone particles of 20-53 microns diameter. These cells differentiated into tartrate resistant acid phosphatase (TRAP)-positive, bone resorbing, multinucleated syncytia in the presence of cytosine-1-beta-D-arabinofuranoside in a time dependent manner (day 1-6). Differentiation into osteoclast-like cells was similar whether cultured on plastic, on glass, or on bone. When compared to GAP-DH control levels, tensin and cortactin mRNA levels increased by 7- and 10-fold, respectively, by day 6. Tensin and cortactin protein levels also increased by 6- and 15-fold, respectively, by day 6. Immunofluorescence of differentiating precursors showed that tensin localized between regions of cell to cell contact and colocalized with vinculin in podosomes of osteoclast-like cells and of real osteoclasts. Cortactin immunofluorescence was not detectable in monocytes but localized inside tensin/vinculin podosome structures after fusion into osteoclast-like cells and in freshly isolated osteoclasts. Both tensin and cortactin were associated with attachment complexes used by osteoclast-like cells and osteoclasts to resorb bone. Specifically, punctate cortactin staining was observed inside tensin staining which formed a double ring structure at the membrane/bone interface of resorbing osteoclasts. These data showed that tensin and cortactin can be used as osteoclast differentiation markers, that participate in attachment complexes used to resorb bone, and that tensin may participate in the fusion process of osteoclast precursors.

Microtubule dynamics in fish melanophores

We have studied the dynamics of microtubules in black tetra (Gymnocorymbus ternetzi) melanophores to test the possible correlation of microtubule stability and intracellular particle transport. X-rhodamine-or caged fluorescein-conjugated tubulin were microinjected and visualized by fluorescence digital imaging using a cooled charge coupled device and videomicroscopy. Microtubule dynamics were evaluated by determining the time course of tubulin incorporation after pulse injection, by time lapse observation, and by quantitation of fluorescence redistribution after photobleaching and photoactivation. The time course experiments showed that the kinetics of incorporation of labeled tubulin into microtubules were similar for cells with aggregated or dispersed pigment with most microtubules becoming fully labeled within 15-20 min after injection. Quantitation by fluorescence redistribution after photobleaching and photoactivation confirmed that microtubule turnover was rapid in both states, t1/2 = 3.5 +/- 1.5 and 6.1 +/- 3.0 min for cells with aggregated and dispersed pigment, respectively. In addition, immunostaining with antibodies specific to posttranslationally modified alpha-tubulin, which is usually enriched in stable microtubules, showed that microtubules composed exclusively of detyrosinated tubulin were absent and microtubules containing acetylated tubulin were sparse. We conclude that the microtubules of melanophores are very dynamic, that their dynamic properties do not depend critically on the state of pigment distribution, and that their stabilization is not a prerequisite for intracellular transport.

The c-erbA beta thyroid hormone receptor. Expression and cDNA sequence analysis of the hormone-binding domain in human cancer cell lines

The human c-erbA beta protooncogene encodes a thyroid hormone receptor (comprising a hormone-binding domain and a DNA-binding domain) which modulates expression of specific genes, such as cell differentiation genes. Using the reverse transcription and polymerase chain reaction (RT-PCR) assay, significant expression of the c-erbA beta gene was detected in the SiHa, CaSki, HeLa cervical carcinoma; Hep3B, PLC/PRF/5, Mahlavu hepatocellular carcinoma; HT-1080 fibrosarcoma cell lines; as well as in normal MRC-5 embryo lung and FS-4 foreskin fibroblast cell lines. However, the Molt-4 leukaemia and Raji Burkitt's lymphoma cell lines exhibited very low levels of c-erbA beta expression. Single-strand conformation polymorphism analysis and direct sequencing of PCR products of the c-erbA beta hormone-binding domain cDNAs of these cell lines revealed identical sequences, but differed from the published human placental c-erbA beta sequence by five single base disparities. Sequencing of an aberrant fragment fortuitously amplified from the HT-1080 cDNA library demonstrated concordance with the cDNA of pregnancy-specific glycoprotein 4, which is related to the tumour marker, carcinoembryonic antigen.

The C-reactive protein (CRP) in patients with long bone fractures and after arthroplasty

Between March 1991 and February 1992 serial serum C-reactive protein (CRP) levels were measured prospectively for three weeks in 57 consecutive patients with fractures of long bones, and also in 11 patients who had undergone primary total hip or knee arthroplasty. A semi-quantitative capillary floculation method was used for measuring the CRP level. The highest values were usually recorded 2-3 days after trauma or operation, and the CRP was nearly normal by three weeks. In the patients with long bone fractures the amplitude of CRP response was affected by the type of treatment. Lower values were observed in those patients treated conservatively than in those who underwent operation, but the profile of CRP response was similar, regardless of the type of treatment. The CRP response was also affected by the severity of the trauma in conservatively treated patients, but in those who underwent operation the CRP response was similar, regardless of the severity of the injury. In patients with primary total hip or knee arthroplasty the pattern of CRP response after operation was similar to that in the patients with long bone fractures who underwent surgical treatment. Awareness of the natural course of the CRP response after fracture and arthroplasty may help in the diagnosis of early post-traumatic and postoperative complications, especially infections.