Timing of ibuprofen use and bone mineral density adaptations to exercise training

Prostaglandins (PGs) are essential signaling factors in bone mechanotransduction. In animals, inhibition of the enzyme responsible for PG synthesis (cyclooxygenase) by nonsteroidal anti-inflammatory drugs (NSAIDs) blocks the bone-formation response to loading when administered before, but not immediately after, loading. The aim of this proof-of-concept study was to determine whether the timing of NSAID use influences bone mineral density (BMD) adaptations to exercise in humans. Healthy premenopausal women (n = 73) aged 21 to 40 years completed a supervised 9-month weight-bearing exercise training program. They were randomized to take (1) ibuprofen (400 mg) before exercise, placebo after (IBUP/PLAC), (2) placebo before, ibuprofen after (PLAC/IBUP), or (3) placebo before and after (PLAC/PLAC) exercise. Relative changes in hip and lumbar spine BMD from before to after exercise training were assessed using a Hologic Delphi-W dual-energy X-ray absorptiometry (DXA) instrument. Because this was the first study to evaluate whether ibuprofen use affects skeletal adaptations to exercise, only women who were compliant with exercise were included in the primary analyses (IBUP/PLAC, n = 17; PLAC/PLAC, n = 23; and PLAC/IBUP, n = 14). There was a significant effect of drug treatment, adjusted for baseline BMD, on the BMD response to exercise for regions of the hip (total, p < .001; neck, p = .026; trochanter, p = .040; shaft, p = .019) but not the spine (p = .242). The largest increases in BMD occurred in the group that took ibuprofen after exercise. Total-hip BMD changes averaged -0.2% +/- 1.3%, 0.4% +/- 1.8%, and 2.1% +/- 1.7% in the IBUP/PLAC, PLAC/PLAC, and PLAC/IBUP groups, respectively. This preliminary study suggests that taking NSAIDs after exercise enhances the adaptive response of BMD to exercise, whereas taking NSAIDs before may impair the adaptive response.

Wheel running, skeletal muscle aerobic capacity and 1-methyl-1-nitrosourea induced mammary carcinogenesis in the rat

Emerging evidence indicates that intrinsic differences and induced changes in aerobic capacity are probably to play a critical role in the development of chronic diseases like cancer. This study was initiated: (i) to determine how citrate synthase activity, which is routinely used as a marker of aerobic capacity and mitochondrial density in skeletal muscle, was affected by voluntary running on either a motorized activity wheel or a non-motorized free wheel and (ii) to investigate the association between aerobic capacity and the carcinogenic response induced in the mammary gland by intraperitoneal injection of 1-methyl-1-nitrosurea. Overall, wheel running reduced cancer incidence (96 versus 72%, P = 0.0006) and the number of cancers per animal (2.84 versus 1.78, P < 0.0001) and induced citrate synthase activity (276 versus 353 U/mg, P < 0.0001, sedentary control versus wheel running,respectively). Both motorized and free wheel running increased citrate synthase activity (373 +/- 24, 329 +/- 11 and 276 +/- 9 U/mg protein, P < 0.0001) and reduced the average number of cancers per rat (2.84, 1.96 and 1.63, P < 0.01), sedentary control, free wheel and motorized wheel, respectively. However, regression analyses failed to provide evidence of a significant association between citrate synthase activity and either cancer incidence or cancer multiplicity. Citrate synthase activity is a single measure in a complex pathway that determines aerobic capacity. The multifaceted nature of intrinsic and inducible aerobic capacity limits the usefulness of citrate synthase activity alone in elucidating the relationship between aerobic capacity and the carcinogenic response.

Lack of suppression of circulating free fatty acids and hypercholesterolemia during weight loss on a high-fat, low-carbohydrate diet

BACKGROUND

Little is known about the comparative effect of weight-loss diets on metabolic profiles during dieting.

OBJECTIVE

The purpose of this study was to compare the effect of a low-carbohydrate diet (< or =20 g/d) with a high-carbohydrate diet (55% of total energy intake) on fasting and hourly metabolic variables during active weight loss.

DESIGN

Healthy, obese adults (n = 32; 22 women, 10 men) were randomly assigned to receive either a carbohydrate-restricted diet [High Fat; mean +/- SD body mass index (BMI; in kg/m(2)): 35.8 +/- 2.9] or a calorie-restricted, low-fat diet (High Carb; BMI: 36.7 +/- 4.6) for 6 wk. A 24-h in-patient feeding study was performed at baseline and after 6 wk. Glucose, insulin, free fatty acids (FFAs), and triglycerides were measured hourly during meals, at regimented times. Remnant lipoprotein cholesterol was measured every 4 h.

RESULTS

Patients lost a similar amount of weight in both groups (P = 0.57). There was an absence of any diet treatment effect between groups on fasting triglycerides or on remnant lipoprotein cholesterol, which was the main outcome. Fasting insulin decreased (P = 0.03), and both fasting (P = 0.040) and 24-h FFAs (P < 0.0001) increased within the High Fat group. Twenty-four-hour insulin decreased (P < 0.05 for both groups). Fasting LDL cholesterol decreased in the High Carb group only (P = 0.003). In both groups, the differences in fasting and 24-h FFAs at 6 wk were significantly correlated with the change in LDL cholesterol (fasting FFA: r = 0.41, P = 0.02; 24-h FFA: r = 0.52, P = 0.002).

CONCLUSIONS

Weight loss was similar between diets, but only the high-fat diet increased LDL-cholesterol concentrations. This effect was related to the lack of suppression of both fasting and 24-h FFAs.

Methodological issues in weight cycling

Recent studies have suggested that weight changes may be related to disease risk independent of weight status. A critical step in testing this assertion is the measurement of weight change and so-called "weight cycling". However intuitive the concept of weight cycling may appear, research in this area is hampered by complex methodological issues. This article discusses various measures of nominal weight cycling, including the standard deviation, coefficient of variation, regression techniques, and cycles. A cycle is a sequence of a gain followed by a loss or vice versa. The various measures are compared in seven hypothetical cases created to illustrate their strengths and weaknesses. Superior performance of the cycles measure over the coefficient of variation, number of fluctuations, and simple regression methods is argued. The linkage of the cycles measure with the statistical theory of runs also provides a basis for testing the significance of weight fluctuations or other variables that may cycle, such as blood lipids, etc. The cycles measure and runs test provide a viable definition for identifying weight cycling and a tool for evaluating the critical amount of weight gained and/or lost in relationship to risk.

Walking economy in people with Parkinson's disease

Gait dysfunction is an early problem identified by patients with Parkinson's disease (PD). Alterations in gait may result in an increase in the energy cost of walking (i.e., walking economy). The purpose of this study was to determine whether walking economy is atypical in patients with PD when compared with healthy controls. A secondary purpose was to evaluate the associations of age, sex, and level of disease severity with walking economy in patients with PD. The rate of oxygen consumption (VO(2)) and other responses to treadmill walking were compared in 90 patients (64.4 +/- 10.3 years) and 44 controls (64.6 +/- 7.3 years) at several walking speeds. Pearson correlation coefficients (r) were calculated to determine relationships of age, sex, and disease state with walking economy in PD patients. Walking economy was significantly worse in PD patients than in controls at all speeds above 1.0 mph. Across all speeds, VO(2) was 6 to 10% higher in PD patients. Heart rate, minute ventilation, respiratory exchange ratio, and rating of perceived exertion were correspondingly elevated. No significant relationship of age, sex, or UPDRS score with VO(2) was found for patients with PD. The findings suggest that the physiologic stress of daily physical activities is increased in patients with early to mid-stage PD, and this may contribute to the elevated level of fatigue that is characteristic of PD.

General outcome measures for verbal operants

A general outcome measure (GOM) can be used to show progress towards a long-term goal. GOMs should sample domains of behavior across ages, be sensitive to change over time, be inexpensive and easy to use, and facilitate decision making. Skinner's (1957) analysis of verbal behavior may benefit from the development of GOM. To develop GOM, we conducted a review of the literature on mands, tacts, echoics, and intraverbals. The four areas reviewed included (a) an examination of the participant's response form (i.e., vocal or nonvocal), (b) the type of prompt used, (c) types of materials used, and (d) timing of responses or sessions. Based on the review of the literature, we developed GOM for mands and tacts. This paper attempts to bridge the concept of GOMs with Skinner's analysis of verbal behavior.

Prescription copay reduction program for diabetic employees: impact on medication compliance and healthcare costs and utilization

OBJECTIVE

To examine the impact of a value-based benefit design on utilization and expenditures.

METHODS

This benefit design involved all diabetes-related drugs and testing supplies placed on the lowest copay tier for 1 employer group. The sample of diabetic members were enrolled from a 9-month preperiod and for 2 years after the benefit design was implemented. Measured outcomes included prescription drug utilization for diabetes and medical utilization. Generalized measures were used to estimate differences between years 1 and 2 and the preperiod adjusting for age, gender, and comorbidity risk.

RESULTS

Diabetes prescription drug use increased by 9.5% in year 1 and by 5.5% in year 2, and mean adherence increased by 7% to 8% in year 1 and fell slightly in year 2 compared with the preperiod. Pharmacy expenditures increased by 47% and 53% and expenditures for diabetes services increased by 16% and 32% in years 1 and 2, respectively.

CONCLUSION

Increases in adherence and use of diabetes medications were observed. There were no compensatory cost-savings for the employer through lower utilization of medical expenditures in the first 2 years. Adherent patients had fewer emergency department visits than nonadherent patients after the implementation of this benefit design.

Mechanisms associated with dose-dependent inhibition of rat mammary carcinogenesis by dry bean (Phaseolus vulgaris, L.)

The purpose of this study was to determine whether a dry bean (Phaseolus vulgaris, L.) containing diet exerts an inhibitory effect on mammary carcinogenesis in a well-characterized rodent model for breast cancer. Twenty-one-d-old female Sprague Dawley rats were given an intraperitoneal injection of 1-methyl-1-nitrosourea and 7 d after carcinogen injection were randomized to 1 of 5 groups fed a modification of the AIN-93G diet formulation containing 0, 7.5, 15, 30, or 60% (wt:wt) small red dry bean incorporated as cooked, freeze-dried, and milled powder. All experimental diets had the same macronutrient content based on proximate analysis. Compared with the control group, dry bean consumption resulted in dose-dependent reductions in mammary cancer incidence (P = 0.046), cancer multiplicity (P = 0.001), and tumor burden (P = 0.01). Dry bean consumption was associated with dose-dependent reductions in plasma concentrations of glucose, insulin, insulin-like growth factor-1, C-reactive protein, and interleukin-6 in food-deprived rats. Analysis of mammary adenocarcinomas indicated that a dominant mechanism accounting for reduced tumor burden was the induction of apoptosis. B cell lymphoma 2 and X-linked inhibitor of apoptosis protein levels decreased and BCL-2-associated X protein increased with increasing dry bean consumption, findings consistent with the induction of apoptosis via the mitochondrial pathway. These data demonstrate that a legume without noteworthy content of isoflavones inhibits the development of mammary carcinogenesis and are consistent with a recent report from the Nurses Health Study that bean or lentil intake is associated with a lower risk for breast cancer.

Vitamin D intervention by pharmacists in geriatric outpatients

OBJECTIVES

To develop a pharmacist-provided educational intervention that instructs participants to consume 1,200 IU vitamin D daily and to evaluate its effect on serum 25-hydroxyvitamin D (vitamin D) concentrations and self-reported daily vitamin D intake in geriatric outpatients with insufficient vitamin D.

DESIGN

Randomized controlled trial.

SETTING

University-affiliated geriatric clinic, December 2005 to May 2006.

PATIENTS

80 participants aged 65 to 89 years.

INTERVENTION

Participants with insufficient vitamin D (12-31 ng/mL) were randomized to receive either the educational intervention (n = 23) or no intervention (n = 22).

MAIN OUTCOME MEASURES

Difference in change from baseline to 12 weeks in vitamin D concentrations and self-reported daily vitamin D intake between groups.

RESULTS

At 12 weeks, vitamin D concentrations in the educational intervention group (n = 22) increased from a mean (+/- SD) of 23.5 +/- 5.0 to 30.4 +/- 6.3 ng/mL. Vitamin D concentrations in the nonintervention group (n = 21) increased from 22.8 +/- 5.4 to 26.9 +/- 6.2 ng/mL. The difference between the groups at 12 weeks did not reach statistical significance (P = 0.07). However, 12 participants (55%) in the educational intervention group achieved sufficient vitamin D concentrations compared with only 5 participants (24%) in the nonintervention group (P = 0.04). Self-reported daily vitamin D intake increased by a mean of 647 IU/day in the educational intervention group and 67 IU/day in the nonintervention group. The difference in self-reported intake between groups at 12 weeks, controlling for baseline, was significant (P < 0.0001). Serum parathyroid hormone concentrations decreased significantly among those in the intervention group (P = 0.04).

CONCLUSION

A pharmacist-developed and -administered vitamin D educational intervention increased the proportion of participants achieving sufficient vitamin D concentrations, increased the self-reported daily vitamin D intake, and lowered serum parathyroid hormone concentrations. However, it did not significantly increase the overall mean serum vitamin D concentration, compared with the control group. A daily recommendation of more than 1,200 IU vitamin D daily is likely necessary to ensure that all geriatric outpatients with insufficient vitamin D concentrations achieve the target of at least 32 ng/mL.

Relative contributions of adiposity and muscularity to physical function in community-dwelling older adults

OBJECTIVE

To determine the relative contributions of adiposity and muscularity to multi-dimensional performance-based and perceived physical function in older adults living independently.

METHODS AND PROCEDURES

Data from 109 women and men, aged 60 or older, with low serum dehydroepiandrosterone (DHEA) sulfate levels were included in this cross-sectional analysis of baseline measures from a single-site, randomized, controlled trial of DHEA replacement therapy. Physical function was determined by means of performance on the 100-point Continuous Scale-Physical Functional Performance (CS-PFP) test and by self-reporting using the physical function subscale of the Medical Outcomes Short Form-36 (SF36PF). Body composition was measured by dual-energy X-ray absorptiometry (DXA). Linear regression analyses were used to determine the contributions of body mass index (BMI; kg body mass/m2), fat index (FI; kg fat/m2), and appendicular skeletal muscle index (ASMI; kg muscle/m2) to the CS-PFP and SF36PF scores, adjusted for age and sex.

RESULTS

Age-adjusted regression analyses indicated that FI, but not ASMI, was a significant (P<0.001) determinant of CS-PFP (R2=0.54) and SF36PF (R2=0.37). When adjusted for age and sex, BMI was nearly as good a predictor of CS-PFP (R2=0.50) and SF36PF (R2=0.34) as FI.

DISCUSSION

Adiposity was a stronger predictor of measured and self-reported physical function than was muscularity in older adults living independently. BMI, adjusted for sex, is a reasonable substitute for adiposity in the prediction of physical function.

Plant sterols added to combination statin and colesevelam hydrochloride therapy failed to lower low-density lipoprotein cholesterol concentrations

BACKGROUND

The purpose of this study was to evaluate the effects on LDL-cholesterol (LDL-C) from addition of plant sterol treatment to patients with dyslipidemia already taking a statin and colesevelam hydrochloride (HCl). Current cholesterol treatment guidelines recommend use of plant stanols/sterols to help reach LDL-C goals in patients taking other lipid-lowering therapies. Previous data demonstrate LDL-C lowering by adding stanols/sterols to statins. However, data are conflicting regarding the benefit from combination stanols/sterols with bile acid sequestrants.

METHODS

Fifty-five subjects on a stable dose of statin completed a 10-week, double-blind, randomized study of colesevelam HCl 3.75 g/day alone for 4 weeks, then 6 weeks of additional 2 g/day plant sterol-fortified orange juice (S-OJ) or placebo orange juice (P-OJ). Serum total cholesterol (TC), LDL-C, HDL-cholesterol (HDL-C), triglycerides (TG), apolipoprotein B (ApoB), and high-sensitivity C-reactive protein (hs-CRP) were measured at baseline, 4 weeks, and 10 weeks.

RESULTS

Baseline LDL-C measurements (mean ± SD) were similar between S-OJ and P-OJ groups (122 ± 20 vs 126 ± 24 mg/dL, respectively). Four weeks of colesevelam HCl in combination with a statin significantly reduced TC, LDL-C, and ApoB (9.6%, P < 0.001; 21.9%, P < 0.001; and 8.5%, P = 0.001, respectively), and significantly increased HDL-C (6.2%, P = 0.002) and TG (18.8%, P = 0.002). However, compared to P-OJ, 10 weeks of S-OJ produced no effect on any outcome parameter beyond that of colesevelam HCl.

CONCLUSION

Plant S-OJ appears to be ineffective at further reducing LDL-C when added to statin and colesevelam HCl combination therapy in patients with dyslipidemia.

The effect of lopinavir/ritonavir on the renal clearance of tenofovir in HIV-infected patients

We determined the effects of lopinavir/ritonavir on tenofovir renal clearance. Human immunodeficiency virus-infected subjects taking tenofovir disoproxil fumarate (TDF) were matched on age, race, and gender and were enrolled into one of the following two groups: group 1: subjects taking TDF plus lopinavir/ritonavir plus other nucleoside reverse transcriptase inhibitors (NRTIs); group 2: subjects taking TDF plus NRTIs and/or non-NRTIs but no protease inhibitors. Twenty-four-hour blood and urine collections were carried out in subjects for tenofovir quantification. Drug transporter genotype associations with tenofovir pharmacokinetics were examined. In 30 subjects, median (range) tenofovir apparent oral clearance, renal clearance, and fraction excreted in urine were 34.6 l/h (20.6-89.5), 11.3 l/h (6.2-22.6), and 0.33 (0.23-0.5), respectively. After adjusting for renal function, tenofovir renal clearance was 17.5% slower (P=0.04) in subjects taking lopinavir/ritonavir versus those not taking a protease inhibitor, consistent with a renal interaction between these drugs. Future studies should clarify the exact mechanism and whether there is an increased risk of nephrotoxicity.

Whole-food sources of vitamin A more effectively inhibit female rat sexual maturation, mammary gland development, and mammary carcinogenesis than retinyl palmitate

Previous work using an adolescent rat model for breast cancer showed increased tumor occurrence in rats fed a chemopreventive dose of vitamin A. Preclinical models for nutrient-cancer interactions utilizing defined diets do not replicate the complexity of the human diet and may be inadequate to investigate food patterns associated with reduced cancer risk in humans. To evaluate this concept, the effects of vitamin A on sexual maturation, mammary gland development, and sensitivity to carcinogenesis were determined in the context of a human food-based diet (whole food diet). At 20 d of age (p20), female rats received either a whole-food diet with adequate levels of vitamin A, a diet with a 5.5-fold increase in vitamin A from fruits and vegetables (S diet), or a diet with a 6.2-fold increase in vitamin A provided as retinyl palmitate (RP diet). To determine the effect of dietary intervention on pubertal mammary gland development, the dietary intervention period was restricted to postnatal d 21-63. Rats were injected with 50 mg 1-methyl-1-nitrosourea/kg body weight at d 66. Compared with adolescent rats that consumed the Ad diet, consumption of S and RP diets reduced mammary cancer multiplicity (relative risk approximately 0.7, P < or = 0.002), which was associated with a reduction in alveolar gland development. The S diet suppressed the onset of sexual maturation (P < 0.001) and inhibited markers of mammary alveologenesis more than the RP diet. These data demonstrate that the amount and source of vitamin A consumed by adolescent female rats can influence the onset of puberty, mammary gland alveolar development, and breast cancer risk and highlight the relevance of utilizing whole-food diets to evaluate the role of dietary factors in cancer prevention.

Time course of C-reactive protein reduction with simvastatin therapy in patients with type 2 diabetes mellitus

The aim of this study was to investigate the time course of C-reactive protein (CRP) reduction with simvastatin in patients with type 2 diabetes mellitus. Thirty-five subjects (mean +/- SEM body mass index 32.8 +/- 1 kg/m(2), mean +/- SEM glycated hemoglobin 7.3 +/- 0.2%) were studied using a randomized, crossover, double-blind design. Patients were treated with simvastatin 40 mg or placebo for 28 days, with a minimum 28-day intervening washout. On entry, all subjects had low-density lipoprotein cholesterol >100 mg/dl and/or non-high-density lipoprotein cholesterol >130 mg/dl. High-sensitivity CRP (hs-CRP) was measured on days 0, 1, 3, 7, 14, 21, and 28 of each phase; fasting lipids were measured weekly. The mean hs-CRP level was 4.2 +/- 0.6 mg/L at baseline (>3.0 mg/L represents high risk). After simvastatin administration, there was a significant reduction in levels of log(hs-CRP) (p = 0.001). This effect of simvastatin was seen by day 7 (p = 0.008), with maximal reduction seen at day 14 (p = 0.004; hs-CRP in original units 3.1 +/- 0.5 mg/L with simvastatin and 4.1 +/- 0.6 mg/L with placebo). As expected, the change in hs-CRP was not related to low-density lipoprotein cholesterol reduction. By day 28 with simvastatin, hs-CRP had returned to near baseline levels. In conclusion, in patients with type 2 diabetes mellitus, simvastatin reduced hs-CRP within 7 days. However, this potentially beneficial effect was lost within 28 days.

Dietary botanical diversity affects the reduction of oxidative biomarkers in women due to high vegetable and fruit intake

Many health benefits are associated with a high dietary intake of vegetables and fruit (VF); however, little effort has been expended to determine whether the botanical families from which high-VF diets are formulated affect their biological activities. The objective of this study was to determine whether the botanical diversity of high-VF diets alters the response in oxidative biomarkers for lipid peroxidation and DNA oxidation. Two diets were developed that varied in botanical diversity and provided 8-10 servings of VF/d. The high botanical diversity diet (HBD) included foods from the 18 botanical families that induced a reduction in oxidative damage of lipids or DNA. The low botanical diversity diet (LBD) emphasized 5 of these botanical families based on reports that their bioactive components had high antioxidant activity. A total of 106 women completed the study. Participants consumed 9.1 +/- 2.6 and 8.3 +/- 2.1 servings of VF/d with the LBD and HBD diets. Only the HBD diet induced a significant reduction in DNA oxidation (P < 0.05). Both the LBD and the HBD diets were associated with a reduction in lipid peroxidation (P < 0.01). These findings indicate that botanical diversity plays a role in determining the bioactivity of high-VF diets and that smaller amounts of many phytochemicals may have greater beneficial effects than larger amounts of fewer phytochemicals.

A pilot study evaluating mindfulness-based stress reduction and massage for the management of chronic pain

BACKGROUND

Mindfulness-based stress reduction (MBSR) and massage may be useful adjunctive therapies for chronic musculoskeletal pain.

OBJECTIVE

To evaluate the feasibility of studying MBSR and massage for the management of chronic pain and estimate their effects on pain and mood.

DESIGN

Randomized trial comparing MBSR or massage with standard care.

PARTICIPANTS

Thirty patients with chronic musculoskeletal pain.

MEASUREMENTS

Pain was assessed with 0 to 10 numeric rating scales. Physical and mental health status was measured with the SF-12.

RESULTS

The study completion rate was 76.7%. At week 8, the massage group had average difference scores for pain unpleasantness of 2.9 and mental health status of 13.6 compared with 0.13 (P<.05) and 3.9 (P<.04), respectively, for the standard care group. These differences were no longer significant at week 12. There were no significant differences in the pain outcomes for the MBSR group. At week 12, the mean change in mental health status for the MBSR group was 10.2 compared with -1.7 in the standard care group (P<.04).

CONCLUSIONS

It is feasible to study MBSR and massage in patients with chronic musculoskeletal pain. Mindfulness-based stress reduction may be more effective and longer-lasting for mood improvement while massage may be more effective for reducing pain.

8-Isoprostane F2alpha excretion is reduced in women by increased vegetable and fruit intake

BACKGROUND

Health benefits associated with diets rich in vegetables and fruit (VF) are often attributed to the antioxidant activity of their constituent phytochemicals. However, in vivo evidence that VF actually reduce markers of oxidative stress is limited.

OBJECTIVE

An 8-wk dietary intervention was conducted to test the hypothesis that increased VF consumption decreases oxidative stress. Urinary excretion of 8-isoprostane F2alpha (8-iso-PGF2alpha) was used as an index of whole-body lipid peroxidation.

DESIGN

The diets evaluated had comparable amounts of all macronutrients but varied in their content of VF. After a 2-wk low-VF (3.0 servings/d) run-in diet, 246 women were randomly assigned to receive either 3.6 (low) or 9.2 (high) servings VF/d. The low-VF group was switched to the high-VF diet during the final 2 wk of the study. Blood and first-void urine specimens were obtained at baseline and at 2-wk intervals thereafter.

RESULTS

The run-in diet reduced 8-iso-PGF2alpha concentrations by 33% (P < 0.0001). The excretion of 8-iso-PGF2alpha with the low-VF diet remained the same as that with the run-in diet, whereas urinary concentrations of 8-iso-PGF2alpha were further reduced (P < 0.01) by the high-VF diet, either fed throughout the study or when the diet was switched from low to high VF (P = 0.05). The greatest reductions in 8-iso-PGF2alpha were observed in subjects in the highest quartile of baseline concentrations of 8-iso-PGF2alpha.

CONCLUSIONS

A significant reduction in the excretion of 8-iso-PGF2alpha was induced by the run-in diet and the high-VF diet. The degree of reduction was related to the subject's baseline urinary concentration of 8-iso-PGF2alpha.

In vivo investigation of changes in biomarkers of oxidative stress induced by plant food rich diets

It is well established that vegetables and fruit (VF) contain antioxidant phytochemicals. Consequently, it is expected that individuals who consume diets with a high content of VF should be better protected against oxidative cellular damage than individuals who do not, but not all data support this assumption. The objective of this study was to identify possible explanations for this conundrum. The effects of two diets that differed in VF content on markers of oxidative damage were studied. Sixty-four women participated in a 14-day dietary intervention. Subjects consumed on average either 3.6 or 12.1 servings of VF per day. The primary end points assessed were 8-hydroxy-2-deoxyguanosine (8-oxo-dG) in peripheral lymphocyte DNA and 8-isoprostaglandin F-2alpha (8-iso-PGF2alpha) excreted in urine. Subjects consuming the high versus low VF diet had lower concentrations of 8-oxo-dG (p < 0.01) and of 8-iso-PGF2alpha (p < 0.01). However, the reduction in oxidative end points by high VF was not uniform. Rather, an antioxidant effect was observed primarily in individuals whose oxidative end points at baseline were above the median for the study population. Using change in plasma carotenoids (end point minus baseline measurements) as an index of phytochemical intake, the reduction in oxidative markers was inversely proportional to change in plasma carotenoids; this effect was stronger for lipid peroxidation (p < 0.01) than DNA oxidation (p < 0.05). These findings imply that increasing exogenous antioxidant exposure may primarily benefit individuals with elevated levels of oxidative stress. Null findings do not necessarily indicate that an antioxidant compound lacks in vivo activity.

Effect of cytological fixative and environmental conditions on nuclear morphometric characteristics of squamous epithelial cells in sputum

BACKGROUND

Sputum samples for lung cancer screening trials are typically collected at home into specimen containers prefilled with cytologic fixative. Collection, transit, and storage expose samples to environmental conditions that may introduce artifacts that could confound evaluation. We examined whether the type of cytological fixative and exposure to different environmental conditions introduces artifacts that affect cytological analysis.

METHODS

Sputum fixed in Saccomanno fluid (SAC), containing methyl, ethyl, and propyl alcohols and polyethylene glycol, or CytoRich Red solution (CRR), containing methyl and isopropyl alcohols and ethylene glycol, plus formaldehyde, was aliquoted and exposed for 8 h to the following conditions: (a) -20 degrees C freezer, (b) 60 degrees C oven, (3) direct sunlight, and (4) room temperature. Cell morphometry was evaluated using computer-assisted image analysis (CAIA).

RESULTS

The values obtained for CAIA analysis of sputum were affected by the type of fixative used. Temperature extremes and sunlight dramatically altered nuclear morphometry of SAC-fixed cells. Artifacts were not observed in CRR-fixed cells.

CONCLUSIONS

The effects of environmental exposures were minimized if sputum was placed in a formalin-containing fixative such as CRR. If an alcohol-based fixative such as SAC is used, sample handling, transport, and storage must be monitored to prevent the introduction of artifacts.

Effects of dietary energy repletion and IGF-1 infusion on the inhibition of mammary carcinogenesis by dietary energy restriction

Dietary energy restriction (DER) is a potent inhibitor of mammary carcinogenesis, but the responsible mechanisms are not fully understood. In a number of model systems, DER is associated with a decrease in circulating levels of IGF-1. Moreover, we have recently reported that protection against cancer is lost, and plasma IGF-1 levels are restored to control values when animals are re-fed, i.e., energy repleted (DER-REP). Accordingly, an experiment was designed to determine if infusion of IGF-1 could mimic the effect of DER-REP on the carcinogenic response in animals that were DER. Following 1-methyl-1-nitrosourea injection (50 mg/kg), rats were fed either ad libitum (AL) or 40% DER. After 6 wk, the DER group was divided into three groups: (1) continued DER, (2) DER-REP, or (3) continued DER and infused with 120 mug rh-IGF-1/d (INF) for a duration of 8 d. DER reduced mammary cancer incidence and multiplicity (P < 0.01) versus AL rats. In rats that were DER-REP, cancer incidence increased 1.4-fold and multiplicity increased by 3.6-fold versus DER rats. Plasma IGF-1 were reduced by DER (P < 0.01), an effect that was reversed by DER-REP (P < 0.05). INF increased plasma IGF-1 versus DER rats (P < 0.01) but did not reverse the carcinogenic response. Plasma IGFBP-3 levels were reduced by DER (P < 0.01), but elevated by either REP or INF. Thus, an 8-d period of refeeding following chronic DER (DER-REP) reversed the anticancer effects of DER, and 8 d of IGF-1 infusion without refeeding (INF) did not mimic the effects of the DER-REP on the carcinogenic response.

Effect of Dietary Energy Restriction on Vascular Density during Mammary Carcinogenesis

Inhibition of mammary carcinogenesis by dietary energy restriction is associated with a decrease in cell proliferation and the induction of apoptosis. Although changes in the metabolism of insulin-like growth factor I and glucocorticoids have been proposed to modulate these cellular processes, limitations in blood supply could induce similar effects. To investigate this possibility, female Sprague Dawley rats were given an injection of 1-methyl-1-nitrosourea and fed purified diets ad libitum or at 60% ad libitum intake, i.e., 40% dietary energy restriction. Premalignant mammary pathologies and mammary adenocarcinomas obtained from these rats were processed for vascular density analysis via CD-31 immunostaining. Vascular density, measured as vessels/unit area, of premalignant mammary pathologies and adenocarcinomas from dietary energy restriction rats was reduced 31 and 39%, respectively (P < 0.01). This effect, which was observed in a 50-microm wide band of tissue surrounding each pathology, was exerted on blood vessels > 25 microm2. Conversely, intratumoral vascular density was unaffected by dietary energy restriction. cDNA microarray and Western blot analyses of adenocarcinomas for evidence of dietary energy restriction-mediated effects on vascularization revealed that only the level of vascular endothelial growth factor receptor protein Flk-1 was significantly reduced (P < 0.001). It appears that dietary energy restriction imposes limitations in the supply of blood to developing pathologies, an effect that could directly inhibit the carcinogenic process. The vascular density data imply that dietary energy restriction inhibited the growth of endothelial cells but leave unresolved the question of whether dietary energy restriction had a specific effect on angiogenesis. The factors that account for the failure of dietary energy restriction to limit intratumoral vascularization are not obvious and merit additional investigation.

Targeting Angiogenesis for Mammary Cancer Prevention: Factors to Consider in Experimental Design and Analysis

An experimental model developed to investigate premalignant stages of breast cancer was used to establish a rationale for designing experiments that target angiogenesis for cancer prevention. Blood vessels were identified via CD31 immunostaining, and all vessels that occurred in a 50 μm wide region circumscribing each pathology were counted using a digital imaging technique. The blood vessel density associated with terminal end buds was unaffected by carcinogen treatment, whereas vessel density was higher in intraductal proliferations and ductal carcinoma in situ than in terminal end buds (P &lt; 0.001) and total vascularity increased with morphologic progression. In comparison with intraductal proliferation or ductal carcinoma in situ, mammary carcinomas had higher vascular density in the tissue surrounding the cancer with a marked increase in the number of blood vessels &lt;25 μm2. These data suggest that antiangiogenic chemopreventive agents would inhibit cancer occurrence if initiated at any premalignant stage of the carcinogenic process. Because increased vascular density observed during premalignancy could be explained by the size expansion of the lesion and its encroachment on a preexisting blood supply, by pathology-associated vessel expansion, and/or by angiogenesis, it remains to be determined if antiangiogenic agents will reduce the prevalence of premalignant lesions or cause their accumulation by blocking conversion to carcinomas. Failure to recognize the patterns of vascularization that accompany morphologic progression could limit the success of efforts to target angiogenesis for cancer prevention and lead to misinformation about how agents that affect blood vessel formation or growth inhibit the carcinogenic process.

Targeting angiogenesis for mammary cancer prevention: factors to consider in experimental design and analysis

An experimental model developed to investigate premalignant stages of breast cancer was used to establish a rationale for designing experiments that target angiogenesis for cancer prevention. Blood vessels were identified via CD31 immunostaining, and all vessels that occurred in a 50 microm wide region circumscribing each pathology were counted using a digital imaging technique. The blood vessel density associated with terminal end buds was unaffected by carcinogen treatment, whereas vessel density was higher in intraductal proliferations and ductal carcinoma in situ than in terminal end buds (P < 0.001) and total vascularity increased with morphologic progression. In comparison with intraductal proliferation or ductal carcinoma in situ, mammary carcinomas had higher vascular density in the tissue surrounding the cancer with a marked increase in the number of blood vessels <25 microm(2). These data suggest that antiangiogenic chemopreventive agents would inhibit cancer occurrence if initiated at any premalignant stage of the carcinogenic process. Because increased vascular density observed during premalignancy could be explained by the size expansion of the lesion and its encroachment on a preexisting blood supply, by pathology-associated vessel expansion, and/or by angiogenesis, it remains to be determined if antiangiogenic agents will reduce the prevalence of premalignant lesions or cause their accumulation by blocking conversion to carcinomas. Failure to recognize the patterns of vascularization that accompany morphologic progression could limit the success of efforts to target angiogenesis for cancer prevention and lead to misinformation about how agents that affect blood vessel formation or growth inhibit the carcinogenic process.