Soleus muscle stability in wild hibernating black bears

Based on studies of fast skeletal muscles, hibernating black and brown bears resist skeletal muscle atrophy during months of reduced physical activity and not feeding. The present study examined atrophy sparing in the slow soleus muscle, known to be highly prone to disuse atrophy in humans and other mammals. We demonstrated histochemically that the black bear soleus is rich in slow fibers, averaging 84.0 ± 6.6%. The percentages of slow fibers in fall (87.3 ± 4.9%) and during hibernation (87.1 ± 5.6%) did not differ ( P = 0.3152) from summer. The average fiber cross-sectional area to body mass ratio (48.6 ± 11.7 µm²/kg) in winter hibernating bears was not significantly different from that of summer (54.1 ± 11.8 µm²/kg, P = 0.4186) and fall (47.0 ± 9.7 µm²/kg, P = 0.9410) animals. The percentage of single hybrid fibers containing both slow and fast myosin heavy chains, detected biochemically, increased from 2.6 ± 3.8% in summer to 24.4 ± 24.4% ( P = 0.0244) during hibernation. The shortening velocities of individual hybrid fibers remained unchanged from that of pure slow and fast fibers, indicating low content of the minority myosins. Slow and fast fibers in winter bears exhibited elevated specific tension (kN/m²; 22%, P = 0.0161 and 11%, P = 0.0404, respectively) and maintained normalized power. The relative stability of fiber type percentage and size, fiber size-to-body mass ratio, myosin heavy chain isoform content, shortening velocity, power output, and elevated specific tension during hibernation validates the ability of the black bear to preserve the biochemical and performance characteristics of the soleus muscle during prolonged hibernation.

Estimation of anisotropy coefficient and total attenuation of swine liver at 850 nm based on a goniometric technique: influence of sample thickness

Estimation of optical properties of biologic tissue is crucial for theoretical modeling of laser treatments in medicine. Tissue highly absorbs and scatters the light between 650 nm and 1300 nm, where the laser provides therapeutic effects. Among other properties, the characteristic of biological tissues to scatter the light traveling trough, is described by the anisotropy coefficient (g). The relationship between g and the distribution of the scattered light at different angles is described by Henyey-Greenstein phase function. The measurement of angular distribution of scattered light is performed by the goniometric technique. This paper describes the estimation of g and attenuation coefficient, μt, of swine liver at 850 nm, performed by an ad hoc designed goniometric-based system, where a spectrometer measures intensities of scattered light at fixed angles (0°, 30°, 45°, 60, 120°, 135° and 150°). Both one-term and two-term Henyey-Greenstein phase function have been employed to estimate anisotropy coefficient for forward (gfs) and backward scattering (gbs). Measurements are performed on samples of two thicknesses (60 um and 30 urn) to investigate the influence of this factor on g, and repeated 6 times for each thickness. The estimated values of gfs were 0.947 and 0.951 for thickness of 60 μm and 30 μm, respectively; the estimations of gfs were -0.498 and -0.270 for thickness of 60 μm and 30 μm, respectively. Moreover, μt of liver has been estimated (i.e., 90±20 cm(1)), through Lambert-Beer equation. The comparison of our results with data reported in literature encourages the use of the ad hoc designed tool for performing experiments on other tissue, and at other wavelengths.

The impact of an aromatase inhibitor on body composition and gonadal hormone levels in women with breast cancer

Aromatase inhibitors (AIs) have become the standard adjuvant therapy of postmenopausal breast cancer survivors. AIs induce a reduction of bioavailable estrogens by inhibiting aromatase, which would be expected to induce alterations in body composition, more extensive than induced by menopause. The objectives are to examine the impact of AIs on (1) DXA-scan derived body composition and (2) gonadal hormone levels. This is a sub-analysis of a 2-year double-blind, placebo-controlled, randomized trial of 82 women with nonmetastatic breast cancer, newly menopausal following chemotherapy, who were randomized to risedronate (35 mg once weekly) versus placebo, and stratified for their usage of AI versus no AI. Outcomes included DXA-scan derived body composition and gonadal hormone levels. As a group, total body mass increased in women over 24 months. Women on AIs gained a significant amount of lean body mass compared to baseline as well as to no-AI users (P < 0.05). Women not on an AI gained total body fat compared to baseline and AI users (P < 0.05). Free testosterone significantly increased and sex hormone binding globulin (SHBG) significantly decreased in women on AIs compared to no AIs at 24 months (P < 0.01) while total estradiol and testosterone levels remained stable. Independent of AI usage, chemotherapy-induced postmenopausal breast cancer patients demonstrated an increase of total body mass. AI users demonstrated maintenance of total body fat, an increase in lean body mass and free testosterone levels, and a decrease in SHBG levels compared to no-AI users. The mechanisms and implications of these changes need to be studied further.

Changes in body composition in women with breast cancer on aromatase inhibitors: A two-year trial

9528

Background: Aromatase inhibitors (AIs), the preferred adjuvant therapy of postmenopausal breast cancer patients, induce severe hypo-estrogenemia which differentiates them from the Estrogen-Receptor-Agonists-Antagonists (ERAAs). Little is known about the effect of AIs on body composition. We sought to examine the impact of AIs on body composition, and whether any changes correlate with gonadal hormone levels. Methods: We analyzed a two year double-blind trial (Risedronate's Effect on Bone loss in Breast CAncer, REBBeCA). 81 chemotherapy-induced newly postmenopausal nonmetastatic breast cancer patients had been randomized to risedronate 35 mg once weekly or placebo and followed, some of whom were on or started AI during the trial. Measures included body composition by whole body DXA-scan and serum sex hormone levels. Combining the two treatment arms, we estimated and compared body composition changes in those on (AI) and not on AIs (no-AI) using a linear mixed model, and examined correlations with serum hormone levels. Results: By 24 months, 41 women were on an AI. Over 2 years, lean mass increased by 1159g (p=0.0003) in women on an AI and did not change (85g; p=0.7684) in the no-AI group (adjusted difference, AD=1047g; p=0.0004). Percent fat did not change (0.0; p=0.9344) in those on an AI and increased (1.2; p=0.0097) in the no-AI group (AD=1.6; p=0.0433). The change in estradiol was associated with changes in lean mass (correlation r=0.42, p=0.0020) and percent fat (r=-0.48, p=0.0003). Conclusions: The use of AIs is associated with a decrease in fat mass and an increase in lean mass. The changes in estradiol are associated with alterations in body composition. The mechanisms and implications of these changes need to be studied further.

[Table: see text]

Urinary estrogen metabolites in patients at high risk for breast cancer

Abstract #4080

Background:&#x2028; Variations in estrogen metabolism may be associated with increased breast cancer risk. Women who have preferential metabolism via 16α-hydroxylation are reported to have a higher risk of developing breast cancer compared to women who have preferential metabolism via 2α-hydroxylation. Profiling estrogen metabolites may identify women who are more likely to develop breast cancer within a population of women with known risk factors. Our aim was to evaluate estrogen metabolism in a group of high risk women.&#x2028; Methods:&#x2028; Women were recruited from the Magee-Women's Hospital High Risk Breast Cancer program. Risk factors included first degree family history, atypia, fibrocystic breast disease, BRCA1/2, Ashkenazi Jewish descent. Urine 2:16 OHE ratios were compared among the high risk group, an average risk control group, and a group of women with breast cancer. We also evaluated the relationship between urine 2:16 OHE ratios and epidemiological risk factors including BMI, alcohol use, smoking history and first degree family history.&#x2028; Results:&#x2028; There were 65 high risk patients, 30 breast cancer patients, and 41 controls. The Kruskaul-Wallis rank test and Wilcoxon rank-sum test were used for analysis. There was a significant difference in 2:16 OHE ratios among all three groups, p=0.0001. Urine 2:16 OHE ratios were lower in the high risk group (median 1.15) compared to the control group (2.22), p=0.00, and were lower in the breast cancer group (1.09) compared to the controls, p=0.00. There was a difference in BMI among all three groups, p=0.002. Overall, the 2:16 OHE ratio was positively associated with BMI, p=0.0006, and with alcohol use, p=0.02. Smoking history did not differ among all groups, and there was no association between smoking history and 2:16 OHE ratio. Within the high risk group, family history was not associated with 2:16 OHE ratio.&#x2028; Conclusions:&#x2028; Our research suggests that there is an association between lower urine 2:16 OHE ratios and high risk breast cancer. This association may be linked to specific risk factors such as BMI and alcohol use. This information may help to further elucidate the clinical relevance of using urinary 2:16 OHE ratios as clinical markers and prognostic indicators in this population.

Citation Information: Cancer Res 2009;69(2 Suppl):Abstract nr 4080.

Human serum albumin (HSA) nanoparticles: Reproducibility of preparation process and kinetics of enzymatic degradation

Nanoparticles prepared from human serum albumin (HSA) are versatile carrier systems for drug delivery and can be prepared by an established desolvation process. A reproducible process with a low batch-to-batch variability is required for transfer from the lab to an industrial production. In the present study the batch-to-batch variability of the starting material HSA on the preparation of nanoparticles was investigated. HSA can build dimers and higher aggregates because of a free thiol group present in the molecule. Therefore, the quality of different HSA batches was analysed by size exclusion chromatography (SEC) and analytical ultracentrifugation (AUC). The amount of dimerised HSA detected by SEC did not affect particle preparation. Higher aggregates of the protein detected in two batches by AUC disturbed nanoparticle formation at pH values below 8.0. At pH 8.0 and above monodisperse particles between 200 and 300 nm could be prepared with all batches, with higher pH values leading to smaller particles. Besides human derived albumin a particle preparation was also feasible based on recombinant human serum albumin (rHSA). Under comparable preparation conditions monodisperse nanoparticles could be achieved and the same effects of protein aggregates on particle formation were observed. For nanoparticulate drug delivery systems the enzymatic degradation is a crucial parameter for the release of an embedded drug. For this reason, besides the particle preparation process, particle degradation in the presence of different enzymes was studied. Under acidic conditions HSA as well as rHSA nanoparticles could be digested by pepsin and cathepsin B. At neutral pH trypsin, proteinase K, and protease were suitable for particle degradation. It could be shown that the kinetics of particle degradation was dependent on the degree of particle stabilisation. Therefore, the degree of particle stabilisation will influence drug release after cellular accumulation of HSA nanoparticles.

Mediterranean populations of the lesser white-toothed shrew (Crocidura suaveolens group): an unexpected puzzle of Pleistocene survivors and prehistoric introductions

An earlier study revealed the strong phylogeographical structure of the lesser white-toothed shrew (Crocidura suaveolens group) within the northern Palaearctic. Here, we aim to reconstruct the colonization history of Mediterranean islands and to clarify the biogeography and phylogeographical relationships of the poorly documented Middle East region with the northern Palaearctic. We performed analyses on 998-bp-long haplotypes of the mitochondrial cytochrome b gene of 143 samples collected around the Mediterranean basin, including islands and the Middle East. The analyses suggest that the Cypriot shrew belongs to the rare group of relict insular Pleistocene mammal taxa that have survived to the present day. In contrast, the Cretan, Corsican and Menorcan populations were independently introduced from the Middle East during the Holocene. The phylogeographical structure of this temperate Palaearctic species within the Middle East appears to be complex and rich in diversity, probably reflecting fragmentation of the area by numerous mountain chains. Four deeply divergent clades of the C. suaveolens group occur in the area, meaning that a hypothetical contact zone remains to be located in central western Iran.

The Study of Tamoxifen and Raloxifene (STAR): Change in patient-reported outcomes (PROs) after the end of treatment

1506

Background: STAR is a double-blind, placebo controlled, randomized phase III prevention trial to evaluate the efficacy of 5 years of raloxifene (R) compared to tamoxifen (T) in reducing the incidence of breast cancer in high-risk postmenopausal women. STAR was unblinded on 3/30/2006. Primary clinical outcomes, quality of life (QOL) and symptoms (SXs) were reported (JAMA, 6/2006). We now describe changes in QOL and SXs post-treatment. Methods: Endpoints for QOL were the MOS SF-36 physical (PCS) and mental (MCS) component scales and the CES-D. SXs were measured using a modified checklist from the NSABP BCPT. Questionnaires were administered before treatment, every 6 months until 60 months, and then at 66 or 72 months. Participants enrolled in QOL study at selected sites from 1/4/2000–5/31/2001. SX data were collected on all participants in the main trial. The change in PCS, MCS and SX scales after the end of treatment was analyzed with linear regression. Results: From 7/1/1999–11/4/2004, 19,747 participants enrolled in STAR and were eligible for the SX assessment; 4,338 completed both on- and post-treatment assessments. The QOL study enrolled 1983 participants; 400 completed both on- and post-treatment assessments. CES-D scores improved significantly from on- to off-treatment (p=.007), but less so for those stopping treatment early (p=.03). The MCS and CES-D returned to pre-treatment levels; the PCS remained below (p=0.02). These endpoints did not differ by treatment group. Forgetfulness (p=.01), musculoskeletal (p=.01), vasomotor (p<.0001), dyspareunia (p<.0001), bladder (p=.0002), weight gain (p<.0001), gynecological (p<.0001), and leg cramp (p<.0001) scales decreased in severity after treatment. Those who stopped treatment early had a greater decrease in vasomotor SXs (p=.01) but a lesser decrease in gynecological SXs (p=.02). Patients on T had a greater decrease in the vasomotor (p=.02) and bladder (p=.009) scales and a lesser decrease in weight gain (p=.04). Compared to pre-treatment levels, post-treatment vasomotor SXs decreased (p=0.009) and leg cramps increased (p<.0001). Conclusions: QOL and SXs changed significantly after treatment, largely returning to pre-treatment levels.

No significant financial relationships to disclose.

Studies on the current 137Cs body burden of children in Belarus--can the dose be further reduced?

After the Chernobyl reactor accident wide areas of Belarus were contaminated with radioactive fallout. The verification and documentation of the long-term development of radiation doses is still going on. A population group of special concern are the children living in contaminated regions. The annual dose limit of 1 mSv is still exceeded in some cases, essentially due to high body burdens of 137Cs as indicated by screening measurements with portable incorporation monitors. In this situation the evaluation of possible dose reduction measures in addition to the control of food contamination is being investigated. Special attention is given to the therapeutic application of a pectin preparation (Vitapect), for which a dose-lowering effect is presumed by Belarusian scientists. In a placebo-controlled double-blind study, several groups of contaminated children received a pectin compound named Vitapect for a two-week period during their stay in a sanatorium. For comparison the same number of control groups were given a placebo preparation. The 137Cs body burden of the children was measured at the beginning and the end. The mean relative reduction of the specific activity within the Vitapect groups was found to be approximately 33%, whereas the specific activity of the children who received a placebo decreased only by approximately 14%, due to clean food supply. It is known that pectins chemically bind cations like caesium in the gastrointestinal tract and thereby increase faecal excretion. Theoretical calculations based on this assumption and considering metabolism processes are qualitatively consistent with the experimentally found retention of radiocaesium in the human body after pectin treatment.

The study of tamoxifen and raloxifene (STAR): Initial findings from the NSABP P-2 breast cancer prevention study

LBA5

Background: The STAR trial was designed to compare raloxifene to tamoxifen in terms of relative effect on invasive breast cancer risk and on other beneficial and detrimental outcomes associated with the use of tamoxifen. Methods: The trial opened on 7-1-1999, and accrual was completed November 4, 2004, with 19,747 women enrolled. To be eligible, a woman had to be postmenopausal with a 5-year predicted breast cancer risk of 1.66% as determined by the modified Gail model. Women were randomized and treated in a double-blinded fashion to receive 5 yr of therapy with either 20 mg per day of tamoxifen or 60 mg per day of raloxifene. The protocol-defined monitoring plan called for a final analysis and release of findings when 327 invasive breast cancer cases had been diagnosed in the total population. The mean age of the population at the time of entry into this trial was 58 yr, and the mean 5-yr risk of breast cancer was 4.04%. 93.5% of the women were white; 51.5% had a hysterectomy before entry into the study; 9.2% had a history of LCIS; 71.1% had at least one first-degree relative with a history of breast cancer. The average time on the study is 47 months. Results: There was no difference between the treatment groups in terms of effect on invasive breast cancer: 163 cases in women assigned to tamoxifen and 167 in women assigned to raloxifene (RR = 1.02, 95% CI = 0.82–1.27). The risk of invasive uterine malignancies was 40% less in the raloxifene group (36 in women assigned tamoxifen and 23 in women assigned raloxifene [RR = 0.62, 95% CI = 0.35–1.08]). The risk of non invasive breast cancer was less in the tamoxifen group (57 cases in those assigned to tamoxifen and 81 in those assigned to raloxifene [RR = 1.41, 95% CI = 1.00–2.02]). There were no significant differences between the treatment groups for any of the other invasive cancer sites or for cardiac events, osteoporotic fractures, or deaths. There were fewer thromboembolic events in women taking raloxifene than in those taking tamoxifen. Conclusions: Raloxifene is an effective alternative to tamoxifen for reducing the incidence of invasive breast cancer in postmenopausal women at increased risk of developing the disease and is associated with fewer endometrial cancers, deep vein thromboses, and pulmonary emboli.

[Table: see text]

How conversations about adjuvant hormonal therapy differ from ‘typical‘ oncology discussions: Results of an observational linguistic study

6141

Background: Adjuvant hormonal therapy in breast cancer presents a conversational challenge for oncologists. Oral medications are a relatively new therapeutic paradigm, and many aspects of typical oncology communication, e.g., risk-benefit presentation, goal of therapy, and the role of patient in selecting/continuing therapy, require a different approach in this setting. An observational linguistic study was undertaken to capture how oncologists and patients discuss adjuvant therapy, and to develop recommendations to improve communication. Methods: Letters of invitation were mailed to 800+ community-based oncologists; of these, 14 met the screening criteria and agreed to participate in this study. 28 postmenopausal, early breast cancer patients on or initiating hormonal therapy were recorded during their regularly scheduled visits. Results: Adjuvant hormonal therapy discussions differ from infusional chemotherapy-focused oncology discussions in several ways: Selection of therapy is based on more than efficacy (e.g., cost, side effects); Chance of recurrence is discussed directly, without significant hedging; Disease name (“cancer”) is discussed openly–the word “cancer” is notably absent from other types of oncology discussions; Visits are routine–patients’ lives are no longer “on hold” (unlike other treatment discussions, where chemotherapy is assumed to be at the center of the patient’s life); Time between visits often moves from every three months to every six months after being on hormonal therapy for a year (unlike other therapies, where patients are seen frequently). Conclusions: Analysis of conversations shows that these patients are seen as, in some way, “cured” (goal of therapy is to prevent recurrence) and that patients are “given their lives back.” The conversational frame displays a lack of urgency and emotion, similar to that of discussions of dyslipidemia management and not like other chemotherapy discussions where the emotional content is very high. New models of therapy require new conversational approaches, e.g., where issues like adherence should be addressed directly, and longer-term therapeutic goals take on primary importance.

[Table: see text]

The study of tamoxifen and raloxifene (STAR): First report of patient-reported outcomes (PROs) from the NSABP P-2 Breast Cancer Prevention Study

LBA561

Background: STAR is a double-blind, randomized phase III prevention trial designed to evaluate the relative efficacy of raloxifene (R) compared to tamoxifen (T) in reducing the incidence of invasive breast cancer in high-risk postmenopausal women. In addition to standard safety monitoring, PROs were measured for quality of life (QOL) and symptoms (SXs). Methods: QOL was measured with the MOS SF-36, the CES-D, and the MOS Sexual Activity Questionnaire. SXs were measured using a modified checklist (SCL) from the NSABP P-1 BCPT. Primary endpoints were the SF-36 physical (PCS) and mental (MCS) component scales. A sample size of 1,670 provided statistical power of at least 0.8 (two-tailed test, alpha = .05). The QOL study was open to accrual at selected sites between 1/4/2000 and 5/31/2001, with questionnaires administered at baseline (pre-treatment), q 6 mos until 60 mos, and at 72 mos. SCL data were collected on all STAR participants. Longitudinal analyses used mixed effects modeling for the PCS, MCS, CES-D, and regression analyses were used to compare the average severity of SCL scores between T and R. Results: 19,747 participants enrolled in STAR and were eligible for the SCL assessment, with median follow-up time (mFU) 4.6 yrs. The QOL study enrolled 1,983 participants, 973 assigned to T and 1,010 assigned to R, mFU 5.4 yrs. QOL participants were comparable to women accrued concurrently at non-participating institutions. SCL and QOL forms compliance was high (with a low of 75% at 4.5 yrs for SCL and 74% for QOL). Mean PCS and MCS scores declined modestly over the 60 mos on study, with no significant difference between T and R. Mean CES-D scores worsened slightly on study, but with no significant difference between T and R. However, statistically significant differences (all p’s < .002) were noted between the T and R for severity of SXs, with R women reporting greater musculoskeletal problems, dyspareunia and weight gain and T women reporting greater vasomotor symptoms, leg cramps, bladder and gynecological problems. Conclusions: There were no significant differences between T and R in PROs for physical & mental health or depresson. While SX severity was generally low in this postmenopausal sample, the pattern of SXs differed between T and R.

[Table: see text]

Physicochemical characterization of protamine-phosphorothioate nanoparticles

Protamine-oligonucleotide nanoparticles represent effective colloidal drug carriers for antisense phosphorothioate oligonucleotides (PTO). This study describes improvements in particle preparation and the physicochemical properties of the complexes prepared. The influence of component concentrations, length of the PTO chain and the PTO/protamine weight ratio on particle formation and size, shape and surface charge of the particles were studied in detail. Nanoparticles with diameters of 90-200nm were obtained, using protamine free base (PFB) and phosphorothioate in water. The chemical composition of the nanoparticles was analysed. More than 90% of the PTO could be assembled in the particle matrix using a > or = 1:2 ratio (w/w) of PTO and PFB. About 53-68% of the PFB was incorporated in the particle matrix. The complexes had a zetapotential of -19 up to +32 mV, depending on the PTO/PFB ratio. The kinetics of the assembly of this binary system were observed by dynamic light scattering (DLS) measurements and by sedimentation velocity analysis in the analytical ultracentrifuge (AUC). In addition, scanning electron microscopy (SEM) and atomic force microscopy (AFM) were applied to verify the results of DLS and the ultracentrifuge measurements. According to sedimentation velocity analysis, the particles were only moderately stable in water and unstable in salt solutions. However, the colloidal solution in water could be stabilized by polyethylenglycol 20000 (PEG), which also led to an increase of stability in cell medium.

Multilevel genetic analyses of two European supercolonies of the Argentine ant, Linepithema humile

Some ants have an extraordinary unicolonial social organization, whereby individuals mix freely among physically separated nests. Recently, it was shown that the European population of Linepithema humile consisted of two enormous unicolonial supercolonies. Workers of the same supercolony are never aggressive to each other. In contrast, aggressiveness is invariably high between workers from different supercolonies. Here we investigated whether gene flow occurs between two supercolonies. We identified a contact zone in which we sampled 46 nests. For each nest, aggression tests were conducted against workers from reference nests from both supercolonies. Workers were always very aggressive towards workers of one of the supercolonies but not to workers of the other. Thus, all nests could be clearly assigned to one of the two supercolonies. For 22 of the 46 nests, we genotyped 15-16 workers at five microsatellite loci. A four-level hierarchical analysis of variance revealed very strong genetic differentiation between the two supercolonies (F(SUPERCOLONY-TOTAL) = 0.541) and low differentiation between sectors (i.e. group of nests connected together with trails) within supercolonies (F(SECTOR-SUPERCOLONY) = 0.064). The very high differentiation between the two supercolonies indicates a lack of ongoing gene flow, a conclusion further bolstered by the finding that the two supercolonies share no common alleles at two of the five microsatellite loci. A Bayesian clustering method also revealed the occurrence of two distinct clusters. These clusters exactly match the grouping obtained by aggression tests. None of the 332 genotyped individuals were admixed despite the fact that some nests of the two supercolonies were separated by less than 30 m. These results demonstrate that the two supercolonies have completely separate gene pools.

Is there a difference between diabetic and non-diabetic ITAs? Histomorphological and immunohistochemical examinations of internal thoracic arteries

BACKGROUND

The relative resistance to arteriosclerosis of the internal thoracic artery is clinically valid. The aim of this study was to evaluate the graduation of intima and media fibrosis in ITA parts and to determine the extent of atherosclerosis using immunohistochemical methods related to patients' risk factors.

METHODS

227 distal ITA segments from 144 male and 83 female patients were examined. Mean age was 66.7 +/- 9.03 years. HE and Elastica van Gieson staining was performed to detect intima-/mediafibrosis.

POPULATION

insulin-dependent diabetes mellitus (idDM; n = 35), non-insulin-dependent diabetes mellitus (nidDM; n = 32), irradiation of the chest due to cancer (n = 27), control group with isolated hyperlipidemia, hypertension, peripheral vascular disease (n = 133). 12 ITA segments of each group were examined immunohistochemically using CD34, CD68, Tenascin, Collagen III, Collagen IV.

RESULTS

Histomorphological examinations using HE and Elastica van Gieson stainings showed for idDM-ITAs no fibrosis in 57 %, slight fibrosis in 34 %, medium in 6 %, no severe, for nidDM-ITAs no fibrosis in 63 %, slight 31 %, medium 3 %, severe 3 %, for ITAs after irradiation: no fibrosis in 37 %, slight in 62 %, no medium or severe fibrosis. Compared to the control group there was no statistically significant difference in diabetic ITAs. Immunohistochemical examinations, scored on a 0 - 3 basis with 0 being the lowest (no reaction), 3 the highest (severe reaction), showed mostly no or slight reaction to CD34, CD68, Tenascin, and Collagen III for intima and media, with comparable results for diabetic or "irradiated" ITAs to those of the control group. The most distinct reaction (medium= 2), was detected for Collagen IV, a marker which outlines basement membranes of endothelia and smooth muscle cells of the vessel wall, but without differences between the four groups. No severe reactions were observed.

CONCLUSIONS

The relative resistance of ITA to arteriosclerosis could be demonstrated in 227 ITA segments. Immunohistochemistry supports histomorphological findings. The influence of diabetes mellitus and irradiation remains irrelevant.

Achievement of ultralow emittance beam in the accelerator test facility damping ring

For high luminosity in electron-positron linear colliders, it is essential to generate low vertical emittance beams. We report on the smallest vertical emittance achieved in single-bunch-mode operation of the Accelerator Test Facility, which satisfies the requirement of the x-band linear collider. The emittances were measured with a laser-wire beam-profile monitor installed in the damping ring. The bunch length and the momentum spread of the beam were also recorded under the same conditions. The smallest vertical rms emittance measured at low intensity is 4 pm at a beam energy of 1.3 GeV, which corresponds to the normalized emittance of 1.0x1.0(-8) m. It increases by a factor of 1.5 for a bunch intensity of 10(10) electrons. The measured data agreed to the calculation of intrabeam scattering within much better than a factor of 2.

Optimization of the preparation process for human serum albumin (HSA) nanoparticles

Nanoparticles prepared by desolvation and subsequent crosslinking of human serum albumin (HSA) represent promising carriers for drug delivery. Particle size is a crucial parameter, in particular for the in vivo behaviour of nanoparticles after intravenous injection. The objective of the present study is the development of a desolvation procedure for the preparation of HSA-based nanoparticles under the aspect of a controllable particle size between 100 and 300 nm in combination with a narrow size distribution. A pump-controlled preparation method was established which enabled particle preparation under defined conditions. Several factors of the preparation process, such as the rate of addition of the desolvating agent, the pH value and the ionic composition of the HSA solution, the protein concentration, and the conditions of particle purification were evaluated. The pH value of the HSA solution prior to the desolvation procedure was identified as the major factor determining particle size. Varying this parameter, (mean) particle diameters could be adjusted between 150 and 280 nm, higher pH values leading to smaller nanoparticles. Washing the particles by differential centrifugation led to significantly narrower size distributions. The reproducibility of the particle size and particle size distribution under the proposed preparation conditions was demonstrated by sedimentation velocity analysis in the analytical ultracentrifuge and the cellular uptake of those nanoparticles was studied by confocal microscope imaging and FACS analysis. The stability of the resulting nanoparticles was evaluated by pH and buffer titration experiments. Only pH values distinctly outside the isoelectric pH range of HSA and low salt concentrations were able to prevent nanoparticle agglomeration.

Concurrent sequencing of full-dose CMF chemotherapy and radiation therapy in early breast cancer has no effect on treatment delivery

With the increasing use of breast-conserving therapy plus systemic chemotherapy for the treatment of early breast cancer, the optimal sequencing of radiation therapy and chemotherapy remains controversial. Sequencing of therapy may influence not only treatment delivery, but control rates, complications and cosmesis. The aim of this study was to evaluate whether concurrent sequencing of standard doses of CMF (cyclophosphamide, methotrexate and 5-fluorouracil) and adjuvant radiation therapy for early breast cancer impacted on optimum treatment delivery. As both an intravenous (i.v.) 3-week regimen and classic (standard) CMF were utilised in this study, both types of CMF were compared. The effect of sequencing on complications and treatment delays were also assessed. 116 patients treated with CMF chemotherapy and adjuvant tangent breast radiation were studied. 73 patients were treated prospectively with concurrent therapy and were retrospectively compared with a matched group of 40 patients treated with sequential or sandwich therapy. All patients had stage 1 or 2 cancers. There were no planned dose reductions introduced for either treatment modality. Concurrent sequencing had no impact on the ability to deliver optimum radiation or chemotherapy doses. There was no significant difference in acute Radiation Therapy Oncology Group (RTOG) skin reactions or complications between the two groups. Although small, there was a significant delay (1.32 days (0-15 versus 0.36 (0-7)) in the concurrent group (P=0.03) in the delivery of radiation therapy. Sequencing had no significant effect on haematological parameters. 'Standard' CMF had a more profound effect on treatment delivery than i.v. CMF (Radiation delay 2.2 days versus 0.26, P=0.002, % chemotherapy delivered 93% versus 99% P=0.000004). At a mean follow-up of 2.6 years, there was no difference in the cosmetic scores between the two groups. Both local and distant control rates were excellent. This study has shown that standard radiation therapy can be delivered safely concurrently with CMF chemotherapy. Whether this approach may lead to better control rates in the future needs further study.

Extremely low vertical-emittance beam in the accelerator test facility at KEK

Electron beams with the lowest, normalized transverse emittance recorded so far were produced and confirmed in single-bunch-mode operation of the Accelerator Test Facility at KEK. We established a tuning method of the damping ring which achieves a small vertical dispersion and small x-y orbit coupling. The vertical emittance was less than 1% of the horizontal emittance. At the zero-intensity limit, the vertical normalized emittance was less than 2.8 x 10(-8) rad m at beam energy 1.3 GeV. At high intensity, strong effects of intrabeam scattering were observed, which had been expected in view of the extremely high particle density due to the small transverse emittance.

Coexisting conformations of fibronectin in cell culture imaged using fluorescence resonance energy transfer

Fluorescence resonance energy transfer (FRET) between fluorophores attached to single proteins provides a tool to study the conformation of proteins in solution and in cell culture. As a protein unfolds, nanometer-scale increases in distance between donor and acceptor fluorophores cause decreases in FRET. Here we demonstrate the application of FRET to imaging coexisting conformations of fibronectin (Fn) in cell culture. Fn is a flexible 440-kDa extracellular matrix protein, with functional sites that are regulated by unfolding events. Fn was labeled with multiple donor and acceptor fluorophores such that intramolecular FRET could be used to distinguish a range of Fn conformations. The sensitivity of FRET to unfolding was tested by progressively denaturing labeled Fn using guanidium chloride. To investigate Fn conformation changes during cell binding and matrix assembly, we added labeled Fn to the culture medium of NIH 3T3 fibroblasts. Coexisting conformations of Fn were visualized using fluorescence microscopy, and spectra from specific features were measured with an attached spectrometer. Using FRET as an indicator of Fn conformation, Fn diffusely bound to cells was in a compact state, whereas Fn in matrix fibrils was highly extended. Matrix fibrils exhibited a range of FRET that suggested some degree of unfolding of Fn's globular modules. Fn in cell-associated clusters that preceded fibril formation appeared more extended than diffuse cell-bound Fn but less extended than fibrillar Fn, suggesting that Fn undergoes extension after cell binding and before polymerization. FRET thus provides an approach to gain insight into the integrin-mediated pathway of Fn fibrillogenesis.

Molecular shuttles based on motor proteins: active transport in synthetic environments

Active transport in cells, utilizing molecular motors like kinesin and myosin, provides the inspiration for the integration of active transport into synthetic devices. Hybrid devices, employing motor proteins in a synthetic environment, are the first prototypes of molecular shuttles. Here the basic characteristics of motor proteins are discussed from an engineering point of view, and the experiments aimed at incorporating motor proteins, such as myosins and kinesins, into devices are reviewed. The key problems for the construction of a molecular shuttle are: guiding the direction of motion, controlling the speed, and loading and unloading of cargo. Various techniques, relying on surface topography and chemistry as well as flow fields and electric fields, have been developed to guide the movement of molecular shuttles on surfaces. The control of ATP concentration, acting as a fuel supply, can serve as a means to control the speed of movement. The loading process requires the coupling of cargo to the shuttle, ideally by a strong and specific link. Applications of molecular shuttles can be envisioned, e.g. in the field of nano-electro-mechanical systems (NEMS), where scaling laws favor active transport over fluid flow, and in the bottom-up assembly of novel materials.

Discrepancy between phase behavior of lung surfactant phospholipids and the classical model of surfactant function

The studies reported here used fluorescence microscopy and Brewster angle microscopy to test the classical model of how pulmonary surfactant forms films that are metastable at high surface pressures in the lungs. The model predicts that the functional film is liquid-condensed (LC) and greatly enriched in dipalmitoyl phosphatidylcholine (DPPC). Both microscopic methods show that, in monolayers containing the complete set of phospholipids from calf surfactant, an expanded phase persists in coexistence with condensed domains at surface pressures approaching 70 mN/m. Constituents collapsed from the interface above 45 mN/m, but the relative area of the two phases changed little, and the LC phase never occupied more than 30% of the interface. Calculations based on these findings and on isotherms obtained on the continuous interface of a captive bubble estimated that collapse of other constituents increased the mol fraction of DPPC to no higher than 0.37. We conclude that monolayers containing the complete set of phospholipids achieve high surface pressures without forming a homogeneous LC film and with a mixed composition that falls far short of the nearly pure DPPC predicted previously. These findings contradict the classical model.

Structural insights into the mechanical regulation of molecular recognition sites

Intriguing experimental and computational data are emerging to suggest that mechanical forces regulate the functional states of some proteins by stretching them into nonequilibrium states. Using the extracellular matrix protein fibronectin as an example, we discuss molecular design principles that might control the exposure of a protein's recognition sites, and/or their relative distances, in a force-dependent manner. Fibronectin regulates many cellular functions by binding directly to integrins. Although integrins have a key role in the transduction of force across the cell membrane by coupling the extracellular matrix to the cytoskeleton, the studies reviewed here suggest that fibronectin might be one of the molecules responsible for the initial transformation of mechanical force into a biochemical signal.

Cardiac hypertrophy in the Prague-hypertensive rat is associated with enhanced JNK2 but not ERK tissue activity

Mitogen-activated protein (MAP) kinases are important intracellular mediators for proliferation and hypertrophy and therefore may also regulate cardiomyoblast growth in hypertensive heart disease. Thus, the aim of the present study was to examine the activities of MAP kinases, namely extracellular signal-regulated kinase (ERK)1,2, c-Jun NH2-terminal kinases (JNK)1,2 and p38 MAP kinase, in myocardial tissue of 12-week-old Prague normotensive (PNR) and hypertensive rats (PHR), a model of genetic hypertension with marked cardiac hypertrophy. Systolic blood pressure was 121 +/- 5 in PNR and 208 +/- 15 mm Hg in PHR (p < 0.01). Total heart weight was 247 +/- 4 in PNR vs. 316 +/- 4 mg/100 g body weight in PHR (p < 0.01). Left and right ventricular weights were 121 +/- 5 and 53 +/- 3 in PNR vs. 168 +/- 4 (p < 0.01) and 57 +/- 2 mg/100 g body weight (n.s.) in PHR. Using anti-ERK2 Western blot analysis as well as immunocomplex ERK activity assay, we found no activation of ERK2 in left or right ventricular tissue of PHR and PNR. Similary, p38 MAP kinase phosphorylation and activity were not detectable. In contrast, Western blot analysis using antiphospho-JNK antibodies revealed in myocardial tissue of right and left ventricles significantly greater phosphorylation of JNK2 in PHR than in PNR. This finding was confirmed by immunocomplex JNK activity assay using ATF-2 as substrate, which demonstrated a significant increase in JNK activity in the left ventricle of PHR as compared to PNR (6.4 +/- 1.5 vs. 2.5 +/- 0.5 OD; each n = 5; p < 0.05). In conclusion, cardiac JNK2 seems to be regulated differently from ERK2 in this rat model. In PHR, as compared to PNR, we found enhanced activity of JNK2 in the left and right ventricles suggesting that JNK2 is involved in hypertensive cardiac disease. The rise in JNK in both ventricles may result indirectly from humoral stimuli, e.g., endothelin-1 and/or angiotensin II, and may contribute to ventricular hypertrophy in this model of spontaneous hypertension.

Comparison of the early stages of forced unfolding for fibronectin type III modules

The structural changes accompanying stretch-induced early unfolding events were investigated for the four type III fibronectin (FN-III) modules, FN-III(7), FN-III(8), FN-III(9), and FN-III(10) by using steered molecular dynamics. Simulations revealed that two main energy barriers, I and II, have to be overcome to initiate unraveling of FN-III's tertiary structure. In crossing the first barrier, the two opposing beta-sheets of FN-III are rotated against each other such that the beta-strands of both beta-sheets align parallel to the force vector (aligned state). All further events in the unfolding pathway proceed from this intermediate state. A second energy barrier has to be overcome to break the first major cluster of hydrogen bonds between adjacent beta-strands. Simulations revealed that the height of barrier I varied significantly among the four modules studied, being largest for FN-III(7) and lowest for FN-III(10), whereas the height of barrier II showed little variation. Key residues affecting the mechanical stability of FN-III modules were identified. These results suggest that FN-III modules can be prestretched into an intermediate state with only minor changes to their tertiary structures. FN-III(10), for example, extends 12 A from the native "twisted" to the intermediate aligned state, and an additional 10 A from the aligned state to further unfolding where the first beta-strand is peeled away. The implications of the existence of intermediate states regarding the elasticity of fibrillar fibers and the stretch-induced exposure of cryptic sites are discussed.

Computer modeling of force-induced titin domain unfolding

Titin, a 1 micron long protein found in striated muscle myofibrils, possesses unique elastic and extensibility properties, and is largely composed of a PEVK region and beta-sandwich immunoglobulin (Ig) and fibronectin type III (FnIII) domains. The extensibility behavior of titin has been shown in atomic force microscope and optical tweezer experiments to partially depend on the reversible unfolding of individual Ig and FnIII domains. We performed steered molecular dynamics simulations to stretch single titin Ig domains in solution with pulling speeds of 0.1-1.0 A/ps, and FnIII domains with a pulling speed of 0.5 A/ps. Resulting force-extension profiles exhibit a single dominant peak for each domain unfolding, consistent with the experimentally observed sequential, as opposed to concerted, unfolding of Ig and FnIII domains under external stretching forces. The force peaks can be attributed to an initial burst of a set of backbone hydrogen bonds connected to the domains' terminal beta-strands. Constant force stretching simulations, applying 500-1000 pN of force, were performed on Ig domains. The resulting domain extensions are halted at an initial extension of 10 A until the set of all six hydrogen bonds connecting terminal beta-strands break simultaneously. This behavior is accounted for by a barrier separating folded and unfolded states, the shape of which is consistent with AFM and chemical denaturation data.

Spatially patterned static roughness superimposed on thermal roughness in a condensed phospholipid monolayer

Imaging of diffuse light scattering in reflection from a phospholipid monolayer at the air/water interface has revealed a previously undetected separation of the monolayer into two regions distinguishable by the intensity of their scattering. In monolayers of L-dipalmitoyl phosphatidylcholine in the condensed phase, chiral-shaped domains are surrounded by a brighter region that covers approximately half the monolayer. While the scattered intensity from both regions increases with surface pressure in a manner consistent with scattering from thermally induced capillary waves, the additional scattering from the brighter region indicates a static surface roughness superimposed on the thermal roughness.

Evaluating the financial impact of clinical trials in oncology: results from a pilot study from the Association of American Cancer Institutes/Northwestern University clinical trials costs and charges project

PURPOSE

Medical care for clinical trials is often not reimbursed by insurers, primarily because of concern that medical care as part of clinical trials is expensive and not part of standard medical practice. In June 2000, President Clinton ordered Medicare to reimburse for medical care expenses incurred as part of cancer clinical trials, although many private insurers are concerned about the expense of this effort. To inform this policy debate, the costs and charges of care for patients on clinical trials are being evaluated. In this Association of American Cancer Institutes (AACI) Clinical Trials Costs and Charges pilot study, we describe the results and operational considerations of one of the first completed multisite economic analyses of clinical trials.

METHODS

Our pilot effort included assessment of total direct medical charges for 6 months of care for 35 case patients who received care on phase II clinical trials and for 35 matched controls (based on age, sex, disease, stage, and treatment period) at five AACI member cancer centers. Charge data were obtained for hospital and ancillary services from automated claims files at individual study institutions. The analyses were based on the perspective of a third-party payer.

RESULTS

The mean age of the phase II clinical trial patients was 58.3 years versus 57.3 years for control patients. The study population included persons with cancer of the breast (n = 24), lung (n = 18), colon (n = 16), prostate (n = 4), and lymphoma (n = 8). The ratio of male-to-female patients was 3:4, with greater than 75% of patients having stage III to IV disease. Total mean charges for treatment from the time of study enrollment through 6 months were similar: $57,542 for clinical trial patients and $63,721 for control patients (1998 US$; P =.4)

CONCLUSION

Multisite economic analyses of oncology clinical trials are in progress. Strategies that are not likely to overburden data managers and clinicians are possible to devise. However, these studies require careful planning and coordination among cancer center directors, finance department personnel, economists, and health services researchers.

Two-dimensional crystallization of streptavidin: in pursuit of the molecular origins of structure, morphology, and thermodynamics

The streptavidin two-dimensional (2D) crystallization model has served as a paradigm for molecular self-assembly at interfaces. We have developed quantitative Brewster angle microscopy for the in situ measurement of spatially resolved relative protein surface densities. This allows investigation of both the thermodynamics and morphologies of 2D crystal growth. For crystal structure analysis, we employ TEM on grown crystals transferred to solid substrates. Comparison of results between commercially available streptavidin, recombinant streptavidin, and site-directed streptavidin mutants has provided insight into the protein protein and protein-lipid interactions that underlie 2D crystallization.

Weighing the risks and benefits of tamoxifen treatment for preventing breast cancer

BACKGROUND

In response to findings from the Breast Cancer Prevention Trial that tamoxifen treatment produced a 49% reduction in the risk of invasive breast cancer in a population of women at elevated risk, the National Cancer Institute sponsored a workshop on July 7 and 8, 1998, to develop information to assist in counseling and in weighing the risks and benefits of tamoxifen. Our study was undertaken to develop tools to identify women for whom the benefits outweigh the risks.

METHODS

Information was reviewed on the incidence of invasive breast cancer and of in situ lesions, as well as on several other health outcomes, in the absence of tamoxifen treatment. Data on the effects of tamoxifen on these outcomes were also reviewed, and methods were developed to compare the risks and benefits of tamoxifen.

RESULTS

The risks and benefits of tamoxifen depend on age and race, as well as on a woman's specific risk factors for breast cancer. In particular, the absolute risks from tamoxifen of endometrial cancer, stroke, pulmonary embolism, and deep vein thrombosis increase with age, and these absolute risks differ between white and black women, as does the protective effect of tamoxifen on fractures. Tables and aids are developed to describe the risks and benefits of tamoxifen and to identify classes of women for whom the benefits outweigh the risks.

CONCLUSIONS

Tamoxifen is most beneficial for younger women with an elevated risk of breast cancer. The quantitative analyses presented can assist health care providers and women in weighing the risks and benefits of tamoxifen for reducing breast cancer risk.

Self-assembly of fibronectin into fibrillar networks underneath dipalmitoyl phosphatidylcholine monolayers: role of lipid matrix and tensile forces

The cell-mediated assembly of fibronectin (Fn) into fibrillar matrices is a complex multistep process that is incompletely understood because of the chemical complexity of the extracellular matrix and a lack of experimental control over molecular interactions and dynamic events. We have identified conditions under which Fn assembles into extended fibrillar networks after adsorption to a dipalmitoyl phosphatidylcholine (DPPC) monolayer in contact with physiological buffer. We propose a sequential model for the Fn assembly pathway, which involves the orientation of Fn underneath the lipid monolayer by insertion into the liquid expanded (LE) phase of DPPC. Attractive interactions between these surface-anchored proteins and the liquid condensed (LC) domains leads to Fn enrichment at domain edges. Spontaneous self-assembly into fibrillar networks, however, occurs only after expansion of the DPPC monolayer from the LC phase though the LC/LE phase coexistence. Upon monolayer expansion, the domain boundaries move apart while attractive interactions among Fn molecules and between Fn and domain edges produce a tensile force on the proteins that initiates fibril assembly. The resulting fibrils have been characterized in situ by using fluorescence and light-scattering microscopy. We have found striking similarities between fibrils produced under DPPC monolayers and those found on cellular surfaces, including their assembly pathways.

Phase separation in monolayers of pulmonary surfactant phospholipids at the air-water interface: composition and structure

The phase behavior of monolayers containing the complete set of purified phospholipids (PPL) obtained from calf surfactant was investigated as a model for understanding the phase transitions that precede compression of pulmonary surfactant to high surface pressure. During compression, both fluorescence microscopy and Brewster angle microscopy (BAM) distinguished domains that separated from the surrounding film. Quantitative analysis of BAM grayscales indicated optical thicknesses for the PPL domains that were similar to the liquid condensed phase for dipalmitoyl phosphatidylcholine (DPPC), the most abundant component of pulmonary surfactant, and higher and less variable with surface pressure than for the surrounding film. BAM also showed the optical anisotropy that indicates long-range orientational order of tilted lipid chains for the domains, but not for the surrounding film. Fluorescence microscopy shows that addition of DPPC to the PPL increased the area of the domains. At fixed surface pressures from 20-40 mN/m, the total area of each phase grew in proportion with the mol fraction of DPPC. This constant variation allowed analysis of the DPPC mol fraction in each phase, construction of a simple phase diagram, and calculation of the molecular area for each phase. Our results indicate that the phase surrounding the domains is more expanded and compressible, and contains reduced amounts of DPPC in addition to the other phospholipids. The domains contain a mol fraction for DPPC of at least 96%.