An ambivalent prostate nodule after Bacillus Calmette-Guérin therapy

A 65-year-old patient without specific associated pathology was treated for a high-grade non-invasive papillary urothelial carcinoma by surgery associated with repeated intravesical Bacillus Calmette-Guérin (BCG) instillations. During follow-up, magnetic resonance imaging (MRI) found a clinically indurated prostate nodule with suspected extensive capsular invasion. Prostatic biopsies showed epithelioid and giant-cell granuloma associated with a single focus of adenocarcinoma. Urinary culture test and specific PCR confirmed the involvement of Mycobacterium bovis. The patient was treated first by rifampin, isoniazid and ethambutol and then by rifampin and isoniazid for a total duration of 9 months, with MRI reassessment at various intervals. After BCG therapy, systemic infectious complications but also local complications such as granulomatous disease have been reported, but prostatic abscesses with M. bovis mimicking cancer on MRI are rare. Consequently, we advise specific local urinary and prostate samples to test for mycobacteria (staining, culture, PCR) in order to avoid aggressive high-risk prostatic surgery.

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Bacillus Calmette-Guérin instillations for bladder carcinoma are usually prescribed.

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Infectious complications are rare after instillations and difficult to diagnose.

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This case of prostate nodules after treatment can suggest aggressive prostate cancer.

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A strategy diagnostic based on microbiology and imaging is necessary in our case.

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A trial antibiotic treatment should be considered at the first sign of doubt.

1205 Activity Trackers As A Tool In Sleep Research: Determining Discrepancies In Trackers Vs. PSG

Introduction

Fitness-based wearables and other emerging sensor technologies have the potential to track sleep across large populations longitudinally in at-home environments. To understand how these devices can inform research studies, limitations of available trackers need to be compared to traditional polysomnography (PSG). Here we assessed discrepancies in sleep staging in activity trackers vs. PSG in subjects with various sleep disorders.

Methods

Twelve subjects (age 41-78, 7f, 5m) wore a Fitbit Charge 3 while undergoing a scheduled sleep study. Six subjects had been previously diagnosed with a sleep disorder (5 OSA, 1 CSA). 4 subjects used CPAP throughout the night, 2 had a split night (CPAP 2nd half of the night), and 6 had a PSG only. Activity tracker staging was compared to 2 RPSGTs staging.

Results

Of the 12 subjects, eight subjects’ sleep was detected in the activity tracker, and compared across sleep stages to the PSG (7 female, 1 male, ages 41-78, AHI 0.3-87, RDI 0.5-94.4, sleep efficiency 74%+/-18, 4 PSG, 1 split, 3 CPAP). The activity tracker matched either tech 52% (+/- 13). The average difference in score tech and activity tracker staging for sleep onset (SO) was 16 +/- 15 minutes and wake after sleep onset was 43.5 +/- 44 minutes. Sensitivity, specificity, and balanced accuracy were found for each sleep stage. Respectively, Wake: 0.45+/-0.27, 0.97+/-0.03, 0.71+/-0.12, REM: 0.41+/-0.30, 0.90+/-0.06, 0.60+/-0.28, Light: 0.71+/-0.09, 0.58+/-0.19, 0.65+/-0.10, Deep: 0.63+/-0.52, 0.88+/-0.05, 0.59+/-0.49.

Conclusion

From this study of 12 subjects seen at a sleep clinic for suspected sleep disorders, activity trackers performed best in wake, REM and deep sleep specificity (>=88%), while they lacked sensitivity to REM and wake (<=45%) stages. The tracker did not detect sleep in 4 subjects who had elevated AHI or low sleep efficiency. Further analysis can identify whether discrepancies between the Fitbit and PSG can be predicted by distinct patterns in sleep staging and/or identify subject exclusion criteria for activity tracking studies.

Support

This project in on-going with the support of Academy Diagnostics Sleep and EEG Center and staff.

Baryon-Number Violation by Two Units and the Deuteron Lifetime

We calculate the lifetime of the deuteron with dimension-nine quark operators that violate baryon number by two units. We construct an effective field theory for |ΔB|=2 interactions that give rise to neutron-antineutron (n-n[over ¯]) oscillations and dinucleon decay within a consistent power counting. We calculate the ratio of the deuteron lifetime to the square of the n-n[over ¯] oscillation time up to next-to-leading order. Our result, which is analytical and has a quantified uncertainty, is smaller by a factor ≃2.5 than earlier estimates based on nuclear models, which impacts the indirect bound on the n-n[over ¯] oscillation time and future experiments. We discuss how combined measurements of n-n[over ¯] oscillations and deuteron decay can help to identify the sources of baryon-number violation.

Co-crystal polymorphic control by nanodroplet and electrical confinement

The polymorphic control of the co-crystal carbamazepine–saccharin (CBZ–SAC) metastable form II was achieved by nano-droplet confinement in tandem with droplet surface charging induced by electrospraying the precursor solution.

Scaling analysis of core pressure drop in reduced height integral test facility

Integral test plays essential role to assess the design of the emergency cooling system of nuclear reactors. Different from full height integral test facilities, reduced height integral test facilities have new problems on the pressure drop scaling. This paper mainly focuses on scaling of pressure drop across the core as it is the major pressure drop in primary loop. The analysis of pressure drop across the core has been divided into three terms and each term has been discussed separately based on two conditions: the normal operation condition and natural circulation condition. After that, the total pressure drop ratios under these two conditions have been discussed.

The anti-cancer effects of cisplatin on hepatic cancer are associated with modulation of miRNA-21 and miRNA-122 expression

OBJECTIVE

Cisplatin is an effective chemotherapeutic drug to treat hepatic cancer, but its efficacy is marred by extensive adverse effects. Micro (mi) RNAs are small regulatory RNAs that may be used as molecular targets to better fine-tune chemotherapy in hepatic cancer. In this study, we examined to what extent the anti-cancer effects of cisplatin are associated with expressions of miRNA (miR)-21 and miR-122.

MATERIALS AND METHODS

The growth-inhibiting effects of cisplatin on the human hepatic cell line HepG2 were assessed by MTT assay, while cell apoptosis was documented using DAPI staining. Also, we tested the effects of cisplatin on tumour growth in a mouse tumour xenograft model. Finally, we quantified expression levels of miR-21 and miR-122 in cisplatin-treated HepG2 cells.

RESULTS

We observed that cisplatin significantly decreased the growth of HepG2 cells (p < 0.05 vs control cells) at all tested concentration (5-80 µg/ml) after 24 or 48 hours of treatment. Microscopic studies demonstrated apoptotic signs in cisplatin-treated cells. In the mouse tumour xenograft model, tumour weights and volumes were significantly (p < 0.05 untreated animals) lower after treatment with cisplatin. Also, treatment of HepG2 cells for 48 hours with 20 µg/ml cisplatin was associated with significant decreases in miR-21 expression levels and up-regulation of miR-122.

CONCLUSIONS

The anti-cancer effects of cisplatin are associated with down-regulation of miR-21 expression and up-regulation of miR-122.

NFAT4-dependent miR-324-5p regulates mitochondrial morphology and cardiomyocyte cell death by targeting Mtfr1

Emerging evidence suggest that the abnormal mitochondrial fission participates in pathogenesis of cardiac diseases, including myocardial infarction and heart failure. However, the molecular components regulating mitochondrial network in heart remain largely unidentified. Here we report that NFAT4, miR-324-5p and mitochondrial fission regulator 1 (Mtfr1) function in one signaling axis that regulates mitochondrial morphology and cardiomyocyte cell death. Knocking down Mtfr1 suppresses mitochondrial fission, apoptosis and myocardial infarction. Mtfr1 is a direct target of miR-324-5p, and miR-324-5p attenuates mitochondrial fission, cardiomyocyte apoptosis and myocardial infarction by suppressing Mtfr1 translation. Finally, we show that transcription factor NFAT4 inhibits miR-324-5p expression. Knockdown of NFAT4 suppresses mitochondrial fission and protects cardiomyocyte from apoptosis and myocardial infarction. Our study defines the NFAT4/ miR-324-5p/Mtfr1 axis, which participates in the regulation of mitochondrial fission and cardiomyocyte apoptosis, and suggests potential new treatment avenues for cardiac diseases.

Prognostic value of clinical and immunological markers in acute phase of SFTS virus infection

SFTS virus (SFTSV) is a novel bunyavirus that causes severe fever with thrombocytopenia syndrome (SFTS), an emerging infectious disease that occurred in China in recent years, with an average case fatality rate of 10-12%. Intervention in the early clinical stage is the most effective measure to reduce the mortality rate of disease. To elucidate the natural course of and immune mechanisms associated with the pathogenesis of SFTSV, 59 laboratory-confirmed SFTS patients in the acute phase, who were hospitalized between October 2010 and September 2011, were enrolled in this study, and the patients sera were dynamically collected and tested for SFTSV viral RNA load, 34 cytokines or chemokines and other related laboratory parameters. All clinical diagnostic factors in the acute phase of SFTS were evaluated and assessed. The study showed that the severity of the disease in 11 (18.6%) patients was associated with abdominal pain (p 0.007; OR = 21.95; 95% CI, 2.32-208.11) and gingival bleeding (p 0.001; OR=122.11; 95% CI, 6.41-2328). The IP-10, TNF-α, IL-6, IL-10, granzyme B and HSP70 levels were higher over the 7-8 days in severe cases, accompanied by altered AST, CK and LDH levels. HSP70 (p 0.012; OR=8.29; 95% CI, 1.58-43.40) was independently correlated with the severity of the early acute phase of SFTSV infection. The severity of SFTS can be predicted based on the presence of symptoms such as abdominal pain and gingival bleeding and on the level of HSP70 in the acute phase of the disease.

Cardiac hypertrophy is negatively regulated by miR-541

Heart failure is a leading cause of death in aging population. Cardiac hypertrophy is an adaptive reaction of the heart against cardiac overloading, but continuous cardiac hypertrophy is able to induce heart failure. We found that the level of miR-541 was decreased in angiotensin II (Ang-II) treated cardiomyocytes. Enforced expression of miR-541 resulted in a reduced hypertrophic phenotype upon Ang-II treatment in cellular models. In addition, we generated miR-541 transgenic mice that exhibited a reduced hypertrophic response upon Ang-II treatment. Furthermore, we found miR-541 is the target of microphthalmia-associated transcription factor (MITF) in the hypertrophic pathway and MITF can negatively regulate the expression of miR-541 at the transcriptional levels. MITF(ce/ce) mice exhibited a reduced hypertrophic phenotype upon Ang-II treatment. Knockdown of MITF also results in a reduction of hypertrophic responses after Ang-II treatment. Knockdown of miR-541 can block the antihypertrophic effect of MITF knockdown in cardiomyocytes upon Ang-II treatment. This indicates that the effect of MITF on cardiac hypertrophy relies on the regulation of miR-541. Our present study reveals a novel cardiac hypertrophy regulating pathway that was composed of miR-541 and MITF. Modulation of their levels may provide a new approach for tackling cardiac hypertrophy.

Disparities in uterine cancer epidemiology, treatment, and survival among African Americans in the United States

OBJECTIVE

The objective of this article is to comprehensively review the scientific literature and summarize the available data regarding the outcome disparities of African American women with uterine cancer.

METHODS

Literature on disparities in uterine cancer was systematically reviewed using the PubMed search engine. Articles from 1992 to 2012 written in English were reviewed. Search terms included endometrial cancer, uterine cancer, racial disparities, and African American.

RESULTS

Twenty-four original research articles with a total of 366,299 cases of endometrial cancer (337,597 Caucasian and 28,702 African American) were included. Compared to Caucasian women, African American women comprise 7% of new endometrial cancer cases, while accounting for approximately 14% of endometrial cancer deaths. They are diagnosed with later stage, higher-grade disease, and poorer prognostic histologic types compared to their Caucasian counterparts. They also suffer worse outcomes at every stage, grade, and for every histologic type. The cause of increased mortality is multifactorial. African American and white women have varying incidence of comorbid conditions, genetic susceptibility to malignancy, access to care and health coverage, and socioeconomic status; however, the most consistent contributors to incidence and mortality disparities are histology and socioeconomics. More robust genetic and molecular profile studies are in development to further explain histologic differences.

CONCLUSIONS

Current studies suggest that histologic and socioeconomic factors explain much of the disparity in endometrial cancer incidence and mortality between white and African American patients. Treatment factors likely contributed historically to differences in mortality; however, studies suggest most women now receive equal care. Molecular differences may be an important factor to explain the racial inequities. Coupled with a sustained commitment to increasing access to appropriate care, on-going research in biologic mechanisms underlying histopathologic differences will help address and reduce the number of African American women who disproportionately suffer and die from endometrial malignancy.

LOX-1 abrogation reduces cardiac hypertrophy and collagen accumulation following chronic ischemia in the mouse

We hypothesized that lectin-like oxidized LDL receptor-1 (LOX-1) deletion may inhibit oxidative stress signals, reduce collagen accumulation and attenuate cardiac remodeling after chronic ischemia. Activation of LOX-1 plays a significant role in the development of inflammation, apoptosis and collagen signals during acute ischemia. Wild-type and LOX-1 knockout (KO) mice were subjected to occlusion of left coronary artery for 3 weeks. Markers of cardiac hypertrophy, fibrosis-related signals (collagen IV, collagen-1 and fibronectin) and oxidant load (nicotinamide adenine dinucleotide phosphate oxidase expression, activity of mitogen-activated protein kinases and left ventricular (LV) tissue thiobarbituric acid reactive substances) were analyzed. In in vitro experiments, HL-1 cardiomyocytes were transfected with angiotensin II (Ang II) type 1 receptor (AT1R) or type 2 receptor (AT2R) genes to determine their role in the cardiomyocyte hypertrophy. LOX-1 KO mice had 25% improvement in survival over the 3-week period of chronic ischemia. LOX-1 deletion reduced collagen deposition and cardiomyocyte hypertrophy (∼75%) in association with a decrease in oxidant load and AT1R upregulation (all P<0.05). The LOX-1 KO mice hearts exhibited a disintegrin and metalloproteinase 10 (ADAM10) and a disintegrin and metalloproteinase 17 (ADAM17) expression and matrix metalloproteinase 2 activity, and increased AT2R expression (P<0.05). Attenuation of cardiac remodeling was associated with improved cardiac hemodynamics (LV ±dp/dt and cardiac ejection fraction). In vitro studies showed that it is AT1R, and not AT2R overexpression that induces cardiomyocyte hypertrophy. We demonstrate for the first time that LOX-1 deletion reduces oxidative stress and related intracellular signaling, which leads to attenuation of the positive feedback loop involving AT1R and LOX-1. This results in reduced chronic cardiac remodeling.

Correlation between promoter methylation of glutathione-S-tranferase P1 and oxidative stress in acute-on-chronic hepatitis B liver failure

Promoter methylation of glutathione-S-transferase P1 (GSTP1) may be involved in liver damage caused by oxidative stress in acute-on-chronic hepatitis B-induced liver failure (ACHBLF). This study aimed to explore GSTP1 promoter methylation status and oxidative stress in such patients. DNA was extracted from peripheral blood mononuclear cells (PBMCs) of patients with acute-on-chronic liver hepatitis B-induced liver failure, chronic hepatitis B (CHB) and normal controls, followed by sodium-bisulfite treatment and methylation-specific PCR (MSP) analysis. Plasma malondialdehyde (MDA) adducts levels were detected by enzyme-linked immunosorbent assay as oxidative stress marker. Model for end-stage liver disease (MELD) score was employed to estimate the severity of the liver failure. Eleven of 35 patients with acute-on-chronic liver failure and 3 of 35 patients with stab le hepatitis B displayed GSTP1 promoter methylation, and the difference was significant (χ2)  = 5.71, P = 0.02). No differences in standard liver function tests were found in patients with acute-on-chronic liver failure with and without GSTP1 promoter methylation although the levels of total bilirubin were greater in those with methylation. The levels of MDA adducts were significantly higher in patients with liver failure when compared to those with CHB (12.44 ± 5.38 pmol/mg vs 8.42 ± 5.49 pmol/mg, P < 0.01), and in the patients with liver failure who had promoter methylation the levels were higher than in those who did not (15.2 ± 4.68 pmol/mg vs 11.17 ± 5.29 pmol/mg, P < 0.01). The MELD score was not significantly different between methylated and unmethylated patients with liver failure (P > 0.05), although MDA adducts were correlated with MELD scores in patients with acute-on-chronic liver failure (r = 0.579, P < 0.01). GSTP1 promoter methylation may facilitate oxidative stress-associated liver damage in ACHBLF, and oxidative stress is correlated with ACHBLF severity.

Seasonal Variability in Otariid Energetics: Implications for the Effects of Predators on Localized Prey Resources

Otariids, like other wild mammals, contend with a wide variety of energetic demands across seasons. However, due to the cryptic behaviors of this marine group, few studies have been able to examine longitudinal energetic costs or the potential impact of these costs on seasonal or annual prey requirements. Here we evaluated the changes in energy demand and intake of female California sea lions (Zalophus californianus) during reproductive (n=2 sea lions) and nonreproductive (n=3) periods. Monthly measurements included resting metabolic rate, blood hormone levels, body condition (blubber thickness and body mass), and caloric intake for adult sea lions throughout molting, late pregnancy, lactation, and postweaning. We found that maintenance energy demands decreased from 32.0 to 23.1 MJ d(-1) before pupping, remaining stable at 19.4+/-0.6 MJ d(-1) during lactation and postweaning. Energy intake rates to meet these demands showed marked changes with activity level and the reproductive cycle, reaching a peak intake of 3.6 times baseline levels during lactation. Translating this into prey demands, we find that 20,000 reproductively active females on San Nicolas Island rookeries would maximally require 4,950 metric tons of Pacific whiting during a month of the breeding season. This localized impact is reduced significantly with postbreeding dispersal and demonstrates the importance of considering spatial and temporal factors driving the energetic requirements of predators when designing marine protected areas.

Elastic path controller for assistive devices

Robotic assistive devices that constrain motion along pre-defined paths are useful in reducing maneuvering efforts by human. This paper introduces an Elastic Path Controller (EPC) that adds "elasticity" to the path following and enables dynamic modification of the paths. This permits the users to compensate for changes in the environment such as introduction of new obstacles or for errors in position sensing. The experiments performed on a Scooter cobot show that users can learn to use this novel tool to modify and design guiding paths in a relatively simple way. The operators use the EPC by pushing/pulling against the guided paths to produce the desired deformations. Then, by just dropping the forces and trusting the path controller, they will be brought back to the guided paths.

Abnormal sterol metabolism in holoprosencephaly: studies in cultured lymphoblasts

BACKGROUND

Holoprosencephaly (HPE) is the most common structural malformation of the developing forebrain in humans. The aetiology is heterogeneous and remains unexplained in approximately 75% of patients.

OBJECTIVE

To examine cholesterol biosynthesis in lymphoblastoid cell lines of 228 patients with HPE, since perturbations of cholesterol homeostasis are an important model system to study HPE pathogenesis in animals.

METHODS

An in vitro loading test that clearly identifies abnormal increase of C27 sterols in lymphoblast-derived cells was developed using [2-(14)C] acetate as substrate.

RESULTS

22 (9.6%) HPE cell lines had abnormal sterol pattern in the in vitro loading test. In one previously reported patient, Smith-Lemli-Opitz syndrome was diagnosed, whereas others also had clearly reduced cholesterol biosynthesis of uncertain cause. The mean (SD) cholesterol levels were 57% (15.3%) and 82% (4.7%) of total sterols in these cell lines and controls, respectively. The pattern of accumulating sterols was different from known defects of cholesterol biosynthesis. In six patients with abnormal lymphoblast cholesterol metabolism, additional mutations in genes known to be associated with HPE or chromosomal abnormalities were observed.

CONCLUSIONS

Impaired cholesterol biosynthesis may be a contributing factor in the cause of HPE and should be considered in the evaluation of causes of HPE, even if mutations in HPE-associated genes have already been found.

Comparison of processes and intermediate outcomes between South Asian and European patients with diabetes in Blackburn, north-west England

BACKGROUND

Diabetes and its complications are more prevalent among South Asians than people of European origin and there is some evidence that patients of South Asian origin with diabetes receive poorer quality care.

METHODS

Longitudinal study of patients with diabetes in Blackburn, UK. Processes of care indicators [measurement of blood pressure (BP), cholesterol and glycosolated haemoglobin (HbA1c)] and values of these intermediate outcomes were extracted for all patients registered on a diabetes information system for the period 1995-2001. Differences in processes of care indicators and intermediate outcomes between ethnic groups were estimated after adjusting for the potential confounding factors of sex, age and socioeconomic status (SES). Generalized estimating equations were used to model trends and to test for differences in trends over time.

RESULTS

Process of care was similar in South Asian and European patients. Mean BP and cholesterol concentration fell during the study period. South Asians had a higher level of HbA1c throughout the study period. South Asians had lower levels of BP and cholesterol in 1995 but the differences diminished or were abolished over time. SES did not explain differences between ethnic groups. Analyses stratified by baseline levels of intermediate outcomes (above or within target) demonstrated improvements among above target patients were greater among European patients.

CONCLUSIONS

Processes of care indicators are similar in diabetic patients of South Asian and European origin, irrespective of SES. However, there are worrying differences in improvements over time in the intermediate outcomes, and glycaemic control remained poorer among patients of South Asian origin patients throughout.

Ventricular tachycardia in nonpostoperative pediatric patients: role of radiofrequency catheter ablation

Experience concerning radiofrequency catheter ablation (RFCA) of ventricular tachycardia (VT) in pediatric patients is limited. In adults, success rates vary widely based on the etiology of the VT. Highest success rates have been achieved in patients without structural heart disease. Between March 1998 and December 1999, five young patients (age, 5 months to 15 years; body weight, 5.5-61.6 kg) underwent RFCA for VT at our institution [structurally normal heart (n = 4), preoperative tetralogy of Fallot (n = 1)]. Monomorphic VT was present in four children, and an infant with MIDAS syndrome had polymorphic VT. Clinical presentation varied: palpitations, n = 2, congestive heart failure, n = 3. All patients had been proven to be unresponsive to one to six (median, three) antiarrhythmic drugs. In all five patients, VT could be successfully eliminated by RFCA after a total of nine (range, 1-4) procedures. Activation mapping and pace mapping were used to identify the anatomical substrate, which was located in the right ventricle/right ventricular outflow tract in all four patients with monomorphic VT and in the left ventricular septum/left ventricular free wall in the infant with polymorphic VT. There were no significant complications in any patient. During follow-up (20-42 months), all patients are in normal sinus rhythm. Left ventricular function recovered in all three patients who had initially presented with congestive heart failure. RFCA can be effective, safe, and life saving in children with medically resistant VT who have not been operated on for congenital heart disease, even when the VT is polymorphic. Although the number of patients is small, RFCA may be the treatment of choice for symptomatic VT in pediatric patients.

Spatial perturbation caused by a badger (Meles meles) culling operation: implications for the function of territoriality and the control of bovine tuberculosis (Mycobacterium bovis)

1. The spatial organization of a badger population (North Nibley) is described before and after it was subjected to a UK Ministry of Agriculture, Fisheries and Food badger removal operation (BRO) intended to control bovine tuberculosis. Comparison is made with an undisturbed badger population (Woodchester Park). 2. The Woodchester Park population was organized in group territories with clearly defined boundaries that remained stable during the 3 years of study (1995-97). In North Nibley, however, the badgers' spatial organization was severely perturbed in the first year and, to a lesser extent, also in the second year after the BRO, with badgers using latrines further away from their setts. This resulted in enlarged social group ranges that were difficult to define and overlapped considerably. 3. The disturbance was observed in the removal groups, those immediately adjacent, as well as those at a distance of one or two social groups from the removal area, with an unexpected indication that the latter groups may have been the most affected. 4. The apparent increase in the size of the group ranges in North Nibley was likely to have been caused by an increased proportion of badgers making extra-group excursions in the aftermath of the BRO. 5. Initial recolonization was almost exclusively by females. 6. Although such perturbation might be expected to facilitate disease transmission between badger social groups, there was no evidence that any infectious animals had survived the BRO. However, there were further cattle breakdowns in the area. 7. The behaviour of badgers after the BRO also provided an opportunity to test predictions made by competing hypotheses about the main determinants of the badger's socio-spatial behaviour.

Aromatase inhibition and inactivation

Aromatase is the key enzyme in the synthesis of estrogens and mediates the conversion of androstenedione and testosterone to estrone and estradiol. Because of the importance of estrogen in stimulating breast cancers, the inhibition of estrogen synthesis is a logical approach to treatment. Aromatase is an excellent target for inhibition, because it is the last step in steroid biosynthesis, and, therefore, there are no important downstream enzymes to be affected. In addition, although aromatase is a P-450 enzyme and shares common features with other enzymes in this class, such as liver metabolizing enzymes and steroidogenic enzymes, it has unique features in the aromatizing reaction, features that are amenable to the development of selective inhibition. The approach we took to develop the first aromatase inhibitors was to design substrate analogues based on the structure of androstenedione. Some of these inhibitors, such as 4-hydroxyandrostenedione [4-OHA (later known as formestane)], also cause enzyme inactivation. Instead of being released at the end of the reaction, the substrate analogue remains bound. Therefore, the inhibitor is not required to be present at all times to maintain inhibition, and it has high enzyme specificity. Subsequently, other investigators have taken a different approach to developing compounds based on inhibitors of P-450 enzymes. High selectivity has been achieved with some of these reversible inhibitors. We have developed a unique animal model with human tumors to compare the antitumor efficacy of antiestrogens and aromatase inhibitors and to optimize their use in sequence and combination as a guide for future clinical trials.

Class I major histocompatibility complex anchor substitutions alter the conformation of T cell receptor contacts

An immunogenic peptide (GP2) derived from HER-2/neu binds to HLA-A2.1 very poorly. Some altered-peptide ligands (APL) of GP2 have increased binding affinity and generate improved cytotoxic T lymphocyte recognition of GP2-presenting tumor cells, but most do not. Increases in binding affinity of single-substitution APL are not additive in double-substitution APL. A common first assumption about peptide binding to class I major histocompatibility complex is that each residue binds independently. In addition, immunologists interested in immunotherapy frequently assume that anchor substitutions do not affect T cell receptor contact residues. However, the crystal structures of two GP2 APL show that the central residues change position depending on the identity of the anchor residue(s). Thus, it is clear that subtle changes in the identity of anchor residues may have significant effects on the positions of the T cell receptor contact residues.

Synthesis of 7beta-sulfur analogues of paclitaxel utilizing a novel epimerization of the 7alpha-thiol group

Paclitaxel analogues with a sulfur group at the 7beta position were required for SAR studies. Attempts to generate these compounds by displacing a 7alpha leaving group with sulfur nucleophiles were unsuccessful. Instead, these compounds were successfully prepared from a 7beta-thiol intermediate that was obtained by a base-catalyzed epimerization of the 7alpha-thiol derivative. The epimerization presumably proceeds through a thioaldehyde intermediate and exhibits the opposite stereochemical preference of its oxygen counterpart.

A physical activity screening measure for use with adolescents in primary care

OBJECTIVE

To develop a reliable and valid physical activity screening measure for use with adolescents in primary care settings.

STUDY DESIGN

We conducted 2 studies to evaluate the test-retest reliability and concurrent validity of 6 single-item and 3 composite measures of physical activity. Modifications were based on the findings of the 2 studies, and a best measure was evaluated in study 3. Accelerometer data served as the criterion standard for tests of validity.

RESULTS

In study 1 (N = 250; mean age, 15 years; 56% female; 36% white), reports on the composite measures were most reliable. In study 2 (N = 57; mean age, 14 years; 65% female; 37% white), 6 of the 9 screening measures correlated significantly with accelerometer data. Subjects, however, had great difficulty reporting bouts of activity and distinguishing between intensity levels. Instead, we developed a single measure assessing accumulation of 60 minutes of moderate to vigorous physical activity. Evaluated in study 3 (N = 148; mean age, 12 years; 65% female; 27% white), the measure was reliable (intraclass correlation, 0.77) and correlated significantly (r = 0.40, P<.001) with accelerometer data. Correct classification (63%), sensitivity (71%), and false-positive rates (40%) were reasonable.

CONCLUSION

The "moderate to vigorous physical activity" screening measure is recommended for clinical practice with adolescents.

Synthesis, structure proof, and biological activity of epothilone cyclopropanes

[structure--see text] A semisynthetic route to epothilone cyclopropanes from epothilones A and B is described. Of significance, the deoxygenation of the 12, 13-epoxide to give the corresponding olefin was achieved with high efficiency. The title compounds (8, 9) were active in both tubulin polymerization and cytotoxicity assays, which is in direct contrast to a previously published report. These results provide further evidence that the role of the 12,13-epoxide of epothilones is largely conformational and argue against some of the current pharmacophore models.

Sequence stratigraphy and architecture of the Late Pleistocene Lagniappe delta complex, northeast Gulf of Mexico

During the last fourth-order glacial-interglacial cycle (e.g. post oxygen isotope stage 5) the Lagniappe Delta system located in the northeast Gulf of Mexico, prograded several tens of miles seaward along two main NE-SW and N-S trending fairways. The delta complex is underlain by a well-developed calcareous shale-rich condensed section that was deposited during isotope stage 5. The delta complex comprises many progradational lobes that were deposited during fifth-order sea-level falls and during the fourth-order maximum lowstand and early rise of sea level associated with isotope stages 4 to 2. Each significant fifth-order sea level fall developed a sequence boundary with an unconformity updip and a correlative conformity downdip on which a delta lobe was deposited. Autocyclic processes also lead to deposition of numerous lobes through lobe switching. During the maximum sea-level lowstand, deep erosion related to the development of an extensive incised valley system occurred across the top of the prograding wedges that were deposited during relative sea-level fall (the falling stage systems tract) and modified all of the previous updip unconformities. The base of the incised valley system, and its correlative downdip conformity, form the main fourth-order sequence boundary. It is on this surface that the last part of the delta complex was deposited during the maximum lowstand and early rise of sea-level. Thus, during the last fourth-order cycle, several fifth-order ‘initial’ sequence boundaries and one fourth-order ‘final’ sequence boundary were formed. Infilling of the incised valley system occurred mainly during the early and late rise of sea-level (isotope stages 2 and younger), prior to a major landward shift of deltaic sedimentation in response to the rapid eustatic rise in sea level during isotope stage 1.